Vanadium oxide (VO) based low cost counter electrode in dye sensitized solar cell (DSSC) applications

Energy Technology Data Exchange (ETDEWEB)

Vijayakumar, P.; Pandian, Muthu Senthil; Ramasamy, P., E-mail: ramasamyp@ssn.edu.in [SSN Research Centre, SSN College of Engineering, Kalavakkam-603 110, Chennai, Tamilnadu (India)

2015-06-24

Vanadium oxide nanostars were synthesized by chemical method. The prepared Vanadium oxide nanostars are introduced into dye sensitized solar cell (DSSC) as counter electrode (CE) catalyst to replace the expensive platinum (Pt). The products were characterized by X-ray diffractometry (XRD), scanning electron microscopy (SEM), and Brunauer–Emmett–Teller (BET) method. The photovoltaic performance of the VO as counter electrode based DSSC was evaluated under simulated standard global AM 1.5G sunlight (100 mW/cm{sup 2}). The solar to electrical energy conversion efficiency (η) of the DSSC was found to be 0.38%.This work expands the Counter electrode catalyst, which can help to reduce the cost of DSSC and thereby encourage their fundamental research and commercial application.

A review of laser electrode processing for development and manufacturing of lithium-ion batteries

Science.gov (United States)

Pfleging, Wilhelm

2018-02-01

Laser processes for cutting, annealing, structuring, and printing of battery materials have a great potential in order to minimize the fabrication costs and to increase the electrochemical performance and operational lifetime of lithium-ion cells. Hereby, a broad range of applications can be covered such as micro-batteries, mobile applications, electric vehicles, and stand-alone electric energy storage devices. Cost-efficient nanosecond (ns)-laser cutting of electrodes was one of the first laser technologies which were successfully transferred to industrial high-energy battery production. A defined thermal impact can be useful in electrode manufacturing which was demonstrated by laser annealing of thin-film electrodes for adjusting of battery active crystalline phases or by laser-based drying of composite thick-film electrodes for high-energy batteries. Ultrafast or ns-laser direct structuring or printing of electrode materials is a rather new technical approach in order to realize three-dimensional (3D) electrode architectures. Three-dimensional electrode configurations lead to a better electrochemical performance in comparison to conventional 2D one, due to an increased active surface area, reduced mechanical tensions during electrochemical cycling, and an overall reduced cell impedance. Furthermore, it was shown that for thick-film composite electrodes an increase of electrolyte wetting could be achieved by introducing 3D micro-/nano-structures. Laser structuring can turn electrodes into superwicking. This has a positive impact regarding an increased battery lifetime and a reliable battery production. Finally, laser processes can be up-scaled in order to transfer the 3D battery concept to high-energy and high-power lithium-ion cells.

Development of a simple, low cost chronoamperometric assay for fructose based on a commercial graphite-nanoparticle modified screen-printed carbon electrode.

Science.gov (United States)

Nicholas, Phil; Pittson, Robin; Hart, John P

2018-02-15

This paper describes the development of a simple, low cost chronoamperometric assay, for the measurement of fructose, using a graphite-nanoparticle modified screen-printed electrode (SPCE-G-COOH). Cyclic voltammetry showed that the response of the SPCE-G-COOH enhanced the sensitivity and precision, towards the enzymatically generated ferrocyanide species, over a plain SPCE; therefore the former was employed in subsequent studies. Calibration studies were carried out using chronoamperometry with a 40µl mixture containing fructose, mediator and FDH, deposited onto the SPCE-G-COOH. The response was linear from 0.1mM to 1.0mM. A commercial fruit juice sample was analysed using the developed assay and the fructose concentration was calculated to be 477mM with a precision of 3.03% (n=5). Following fortification (477mM fructose) the mean recovery was found to be 97.12% with a coefficient of variation of 6.42% (n=5); consequently, the method holds promise for the analysis of commercial fruit juices. Copyright © 2017 Elsevier Ltd. All rights reserved.

Development of a membrane electrode assembly production process for proton exchange membrane fuel cell (PEMFC) by sieve printing

International Nuclear Information System (INIS)

Bonifacio, Rafael Nogueira

2010-01-01

Energy is a resource that presents historical trend of growth in demand. Projections indicate that future energy needs will require a massive use of hydrogen as fuel. The use of systems based on the use of proton exchange membrane fuel cell (PEMFC) has features that allow its application for stationary applications, automotive and portable power generation. The use of hydrogen as fuel for PEMFC has the advantage low pollutants' emission, when compared to fossil fuels. For the reactions in a PEMFC is necessary to build membrane electrode assembly (MEA). And the production of MEAs and its materials are relevant to the final cost of kW of power generated by systems of fuel cell. This represent currently a technological and financial barriers to large-scale application of this technology. In this work a process of MEAs fabrication were developed that showed high reproducibility, rapidity and low cost by sieve printing. The process of sieve printing and the ink composition as a precursor to the catalyst layer were developed, which allow the preparation of electrodes for MEAs fabrication with the implementation of the exact catalyst loading, 0.6 milligrams of platinum per square centimeters (mgPt.cm -2 ) suitable for cathodes and 0.4 mgPt.cm -2 for anode in only one application step per electrode. The ink was developed, produced, characterized and used with similar characteristics to ink of sieve printing build for other applications. The MEAs produced had a performance of up to 712 mA.cm -2 by 600 mV to 25 cm 2 MEA area. The MEA cost production for MEAs of 247.86 cm 2 , that can generate 1 kilowatt of energy was estimated to US$ 7,744.14 including cost of equipment, materials and labor. (author)

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.

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)

Development of advanced electrodes for corrosion monitoring in nuclear power plants

International Nuclear Information System (INIS)

Ku, Hee Kwon; Lim, Dong Seok; Cho, Jae Seon

2014-01-01

Much of corrosion-related due to the piping material and coolant are generated for Nuclear Power Plants (NPPs) operation time. During normal-operation, operators manage main factors such as pH, ECP and impurities density by using optimized water-purity operation technique to maintain integrity of piping and structural materials. Various correlations related to the corrosion are developed between metal corrosion and ECP, pH and the effect on the piping and structural, which are the water chemistry factors. In this study, Ag/AgCl and Cu/Cu 2 O(YSZ) pH-sensing electrode for measuring hydrochemistry factors such as ECP, pH operating in NPPs have been developed. The developed sensors are conducted performance tests to prove their validity under the NPPs conditions. In this study, the external Ag/AgCl electrode is developed to resolve the potential drift phenomenon, which is a general phenomenon of conventional Ag/AgCl electrodes, through using the ceramic tube as a potential sensing part and high temperature part, and a related equation is established to calculate the TLJP (Thermal Liquid Junction Potential). The Cu/Cu 2 O electrode as a working electrode is developed using 8%-YSZ membrane. Its relational expression for converting the pH value is established with the Ag/AgCl reference electrode. The developed electrodes are tested to evaluate their response characteristics and stability in low/high temperature conditions. A titration test of the developed electrode is performed using 0.1m-NaCl and 0.01m-HCl solution under the test conditions of 300degC and 2700psi. The test results show that the response characteristics, stability and reproducibility of the manufactured electrodes. Base on the test results, the corrosion environment of carbon-steel (SA106Gr.C) is evaluated by using electrodes completed performance evaluation, and Fepourbaix-diagram is calculated for performance evaluation referred to EPRI report. The conditions of performance evaluation are 1000 ppm

Biomedical engineering tasks. [electrode development for electrocardiography and electroencephalography

Science.gov (United States)

1972-01-01

Electrocardiographic and vectorcardiographic bioinstrumentation work centered on the development of a new electrode system harness for Project Skylab. Evaluation of several silver electrode configurations proved superior impedance voltage performance for silver/silver chloride electrodes mounted flush by using a paste adhesive. A portable ECG processor has been designed and a breadboard unit has been built to sample ECG input data at a rate of 500 samples per second for arrhythmia detection. A small real time display driver program has been developed for statistical analysis on selected QPS features. Engineering work on a sleep monitoring cap assembly continued.

Deliverable D2.4: Status of Dry Electrode Development Activity

NARCIS (Netherlands)

Mihajlovic, V.; Garcia Molina, G.

2010-01-01

The goal of dry electrode development activity within the WP2 is tobuild a dry electrode prototype for brain wave sensing that is comfortable for the user and provides sufficient signal quality. The electrodes are to be utilized in BCI applications, namely Steady-StateVisually Evoked Potential

Concept and Development of an Electronic Framework Intended for Electrode and Surrounding Environment Characterization In Vivo

Directory of Open Access Journals (Sweden)

Stefan B. Rieger

2016-12-01

Full Text Available There has been substantial progress over the last decade towards miniaturizing implantable microelectrodes for use in Active Implantable Medical Devices (AIMD. Compared to the rapid development and complexity of electrode miniaturization, methods to monitor and assess functional integrity and electrical functionality of these electrodes, particularly during long term stimulation, have not progressed to the same extent. Evaluation methods that form the gold standard, such as stimulus pulse testing, cyclic voltammetry and electrochemical impedance spectroscopy, are either still bound to laboratory infrastructure (impractical for long term in vivo experiments or deliver no comprehensive insight into the material’s behaviour. As there is a lack of cost effective and practical predictive measures to understand long term electrode behaviour in vivo, material investigations need to be performed after explantation of the electrodes. We propose the analysis of the electrode and its environment in situ, to better understand and correlate the effects leading to electrode failure. The derived knowledge shall eventually lead to improved electrode designs, increased electrode functionality and safety in clinical applications. In this paper, the concept, design and prototyping of a sensor framework used to analyse the electrode’s behaviour and to monitor diverse electrode failure mechanisms, even during stimulation pulses, is presented. We focused on the electronic circuitry and data acquisition techniques required for a conceptual multi-sensor system. Functionality of single modules and a prototype framework have been demonstrated, but further work is needed to convert the prototype system into an implantable device. In vitro studies will be conducted first to verify sensor performance and reliability.

Recent Advances in Polymeric Materials Used as Electron Mediators and Immobilizing Matrices in Developing Enzyme Electrodes

Directory of Open Access Journals (Sweden)

Mambo Moyo

2012-01-01

Full Text Available Different classes of polymeric materials such as nanomaterials, sol-gel materials, conducting polymers, functional polymers and biomaterials have been used in the design of sensors and biosensors. Various methods have been used, for example from direct adsorption, covalent bonding, crossing-linking with glutaraldehyde on composites to mixing the enzymes or use of functionalized beads for the design of sensors and biosensors using these polymeric materials in recent years. It is widely acknowledged that analytical sensing at electrodes modified with polymeric materials results in low detection limits, high sensitivities, lower applied potential, good stability, efficient electron transfer and easier immobilization of enzymes on electrodes such that sensing and biosensing of environmental pollutants is made easier. However, there are a number of challenges to be addressed in order to fulfill the applications of polymeric based polymers such as cost and shortening the long laboratory synthetic pathways involved in sensor preparation. Furthermore, the toxicological effects on flora and fauna of some of these polymeric materials have not been well studied. Given these disadvantages, efforts are now geared towards introducing low cost biomaterials that can serve as alternatives for the development of novel electrochemical sensors and biosensors. This review highlights recent contributions in the development of the electrochemical sensors and biosensors based on different polymeric material. The synergistic action of some of these polymeric materials and nanocomposites imposed when combined on electrode during sensing is discussed.

Development and application of a labmade apparatus using open-source “arduino” hardware for the electrochemical pretreatment of boron-doped diamond electrodes

International Nuclear Information System (INIS)

Rosa, Thalles Ramon; Betim, Fernando Silva; Ferreira, Rafael de Queiroz

2017-01-01

Highlights: • BDD electrodes use an electrochemical pretreatment (anodic and/or cathodic) to restore their original characteristics and promote the reproduction of previous voltammograms; • Automatic system can carefully reproduce the electrochemical pretreatment of BDD electrode quickly and efficiently; • Open source platform “Arduino” can be used to developed a labmade apparatus to control a BDD electrode pretreatment system for analytical purposes; • The main advantages of this labmade apparatus are: low supporting electrolyte consumption (20 mL), a total time for each pretreatment of 80 seconds and an average cost of production below US$ 200. - Abstract: Every day, new electroanalytical methodologies are developed to supplant the established spectrometric and chromatographic methods due to their versatility, low cost and ability to perform measurements without sample treatment. Electroanalytical techniques have provided an alternative to quantify substances due to the direct relationship between the analyte concentration and some electrical property of the system. However, this ratio between the concentration and peak current is valid only if the electrochemically active area of the working electrode is constant in each electrochemical test. For years, classic polarography ensured the reproducibility of the mercury electrode surface due to its liquid state at room temperature. However, this metal has a high toxicity, driving the search for new inert materials for their replacement, most notably boron-doped diamond (BDD) electrodes. This electrode material has, among other attractive advantages for electroanalysis, a potential range higher than that of the mercury working electrode under the same conditions. Solid electrodes are, in general, polished to promote the reproducibility of their electrochemical performance. For BDD, the use of an electrochemical pretreatment (anodic and/or cathodic) has been sufficient to restore their original

Low-Cost Facile Fabrication of Flexible Transparent Copper Electrodes by Nanosecond Laser Ablation

KAUST Repository

Paeng, Dongwoo

2015-03-27

© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Low-cost Cu flexible transparent conducting electrodes (FTCEs) are fabricated by facile nanosecond laser ablation. The fabricated Cu FTCEs show excellent opto-electrical properties (transmittance: 83%, sheet resistance: 17.48 Ω sq^-1) with outstanding mechanical durability. Successful demonstration of a touch-screen panel confirms the potential applicability of Cu FTCEs to the flexible optoelectronic devices.

Recent Developments of Nanostructured Electrodes for Bioelectrocatalysis of Dioxygen Reduction

Directory of Open Access Journals (Sweden)

Marcin Opallo

2011-01-01

Full Text Available The recent development of nanostructured electrodes for bioelectrocatalytic dioxygen reduction catalysed by two copper oxidoreductases, laccase and bilirubin oxidase, is reviewed. Carbon-based nanomaterials as carbon nanotubes or carbon nanoparticles are frequently used for electrode modification, whereas there are only few examples of biocathodes modified with metal or metal oxide nanoparticles. These nanomaterials are adsorbed on the electrode surface or embedded in multicomponent film. The nano-objects deposited act as electron shuttles between the enzyme and the electrode substrate providing favourable conditions for mediatorless bioelectrocatalysis.

Design and Development of Intelligent Electrodes for Future Digital Health Monitoring: A Review

Science.gov (United States)

Khairuddin, A. M.; Azir, K. N. F. Ku; Kan, P. Eh

2018-03-01

Electrodes are sensors used in electrocardiography (ECG) monitoring system to diagnose heart diseases. Over the years, diverse types of electrodes have been designed and developed to improve ECG monitoring system. However, more recently, with the technological advances and capabilities from the Internet of Things (IoT), cloud computing and data analytics in personalized healthcare, researchers are attempting to design and develop more effective as well as flexible ECG devices by using intelligent electrodes. This paper reviews previous works on electrodes used in electrocardiography (ECG) monitoring devices to identify the key ftures for designing and developing intelligent electrodes in digital health monitoring devices.

Characteristics of indium-free GZO/Ag/GZO and AZO/Ag/AZO multilayer electrode grown by dual target DC sputtering at room temperature for low-cost organic photovoltaics

Energy Technology Data Exchange (ETDEWEB)

Park, Ho-Kyun; Kim, Han-Ki [Department of Display Materials Research Center, Materials Research Center for Information Displays (MRCID), Kyung Hee University, 1 Seocheon-dong, Youngin-si, Gyeonggi-do 446-701 (Korea); Kang, Jae-Wook [Department of Material Processing, Korea Institute of Materials Science(KIMS), 66 Sangnam-dong, Changwon-si, Gyeongnam 641-831 (Korea); Na, Seok-In; Kim, Don-Yu. [Heeger Center for Advanced Materials, Department of Materials Science and Engineering, Gwangju Institute of Science and Technology, 1 Oryoung-dong, Gwangju 500-712 (Korea)

2009-11-15

We compared the electrical, optical, structural and surface properties of indium-free Ga-doped ZnO (GZO)/Ag/GZO and Al-doped ZnO (AZO)/Ag/AZO multilayer electrodes deposited by dual target direct current sputtering at room temperature for low-cost organic photovoltaics. It was shown that the electrical and optical properties of the GZO/Ag/GZO and AZO/Ag/AZO multilayer electrodes could be improved by the insertion of an Ag layer with optimized thickness between oxide layers, due to its very low resistivity and surface plasmon effect. In addition, the Auger electron spectroscopy depth profile results for the GZO/Ag/GZO and AZO/Ag/AZO multilayer electrodes showed no interfacial reaction between the Ag layer and GZO or AZO layer, due to the low preparation temperature and the stability of the Ag layer. Moreover, the bulk heterojunction organic solar cell fabricated on the multilayer electrodes exhibited higher power conversion efficiency than the organic solar cells fabricated on the single GZO or AZO layer, due to much lower sheet resistance of the multilayer electrode. This indicates that indium-free GZO/Ag/GZO and AZO/Ag/AZO multilayer electrodes are a promising low-cost and low-temperature processing electrode scheme for low-cost organic photovoltaics. (author)

The cost of electrocoagulation

Energy Technology Data Exchange (ETDEWEB)

Donini, J.C.; Kan, J.; Szynkarczuk, J.; Hassan, T.A.; Kar, K.L.

1993-01-01

Electrocoagulation could be an attractive and suitable method for separating solids from waste water. The electrocoagulation of kaolinite and bentonite suspensions was studied in a pilot electrocoagulation unit to assess the cost and efficiency of the process. Factors affecting cost such as the formation of passivation layers on electrode plates and the recirculation and concentration of sodium chloride were examined. Colorimetry was used to analyze aluminum content in the suspension. The results were used to calculate the cost due to consumption of electrode material (aluminium) during the process. Total cost was assumed to comprise the energy cost and the cost of electrode material. Comparison was based on the settling properties of the treated product: turbidity, settling rate, and cake height. In most cases, aluminium efficiency averaged around 200% and material cost accounted for 80% of total cost. Although higher concentrations of sodium chloride could only slightly increase aluminium efficiency and electrode efficiency, the higher concentrations resulted in much greater total cost, due to the greater current generated by the increased suspension conductivity, which in turn dissolved a larger amount of aluminium. The recirculation loop increased the flow rate by 3-10 times, enhancing the mass transport between the electrodes and resulting in lower cost and better settling properties. Over the course of two months the electrodes coatings became thicker while efficiency decreased. The electrode efficiency was found to be as high as 94% for virgin electrodes and as low as 10% after two months. 8 refs., 25 figs., 9 tabs.

Transparent platinum counter electrode for efficient semi-transparent dye-sensitized solar cells

Energy Technology Data Exchange (ETDEWEB)

Iefanova, Anastasiia; Nepal, Jeevan; Poudel, Prashant; Davoux, Daren; Gautam, Umesh [Electrical Engineering and Computer Science Department, South Dakota State University, Brookings, SD 57006 (United States); Mallam, Venkataiah [Chemistry and Biochemistry Department, South Dakota State University, Brookings, SD 57006 (United States); Qiao, Qiquan [Electrical Engineering and Computer Science Department, South Dakota State University, Brookings, SD 57006 (United States); Logue, Brian [Chemistry and Biochemistry Department, South Dakota State University, Brookings, SD 57006 (United States); Baroughi, Mahdi Farrokh, E-mail: m.farrokhbaroughi@sdstate.edu [Electrical Engineering and Computer Science Department, South Dakota State University, Brookings, SD 57006 (United States)

2014-07-01

A method for fabrication of highly transparent platinum counter electrodes (CEs) has been developed based on spray coating of Pt nanoparticles (NPs) on hot substrates. This method leads to 86% reduction in Pt consumption reducing the Pt cost per peak watt of counter electrode from $0.79/Wp down to $0.11/Wp compared to the conventional Pt counter electrodes made by sputter deposition. The simplicity and low cost of this method provide a basis for an up-scalable fabrication process. The Pt NP layer is over 88% transparent, leading to overall transparency of 80% when incorporated with indium tin oxide/glass substrates for functional counter electrodes. This counter electrode exhibits a large surface area and high catalytic activity, comparable to that of the conventional opaque CEs. Semi-transparent dye-sensitized solar cells fabricated based on this counter electrode showed 6.17% power conversion efficiency. - Highlights: • Counter electrode (CE) prepared by spraying nanoparticle (NP) Pt on hot substrate. • Low cost and scalable fabrication process of CE. • The spray deposited CE uses 10 times less Pt compared to the sputtering method. • The CE is 80% transparent and exhibits a large surface and high catalytic activity. • A semitransparent dye-sensitized solar cell with Pt NP CE was 6.17% efficient.

Development of performance model of CDI electrode for desalination

Energy Technology Data Exchange (ETDEWEB)

Jeon, Byong Guk

2010-02-15

Demand for clean water is increasing rapidly due to population growth, desertification, and pollution. Capacitive deionization, CDI, is a newly interested technology with its economic merits over existing ones like evaporation and reverse osmosis. The one of main issues on this technology lies on the electrode development. From the first success on a stable electrode development like carbon aerogel, various types of electrodes have been emerged. However, key mechanism and parameters of this technology are not yet provided. This research focuses on revealing how the CDI works and what parameter affects the performance most. For the current experimental techniques have limits in producing well-defined pore arrangement, a simulation tool based on the most sophisticated governing equations has been developed. The governing equations involve Nernst-Planck equation with a convection term to follow ion movement and Poisson equation to follow potential development. The above tool is verified by comparing with analytical solutions and other researcher's results. The first simulation tool for CDI uses the decoupled implicit scheme: however, the scheme faces the numerical constraint of poor convergence. The maximum time step size is highly limited to 1.E-8s. Then an under-relaxation scheme is introduced with the limited success: we can increase its time step size by about 1,000 times higher than that of the decoupled scheme. Finally, the coupled implicit scheme, which solves the equations on concentration and potential simultaneously, is adopted. The newly developed scheme does not suffer from the convergence problem and is found to be optimal for CDI simulation. As the simulation domain, we select a region containing one pore and one electrode gap, to efficiently appreciate key parameters. Key performance indicator, KPI, and system parameters are determined. KPI is defined by the salt removal rate: salt removal amount per electrode volume divided by salt removal time

Development of performance model of CDI electrode for desalination

International Nuclear Information System (INIS)

Jeon, Byong Guk

2010-02-01

Demand for clean water is increasing rapidly due to population growth, desertification, and pollution. Capacitive deionization, CDI, is a newly interested technology with its economic merits over existing ones like evaporation and reverse osmosis. The one of main issues on this technology lies on the electrode development. From the first success on a stable electrode development like carbon aerogel, various types of electrodes have been emerged. However, key mechanism and parameters of this technology are not yet provided. This research focuses on revealing how the CDI works and what parameter affects the performance most. For the current experimental techniques have limits in producing well-defined pore arrangement, a simulation tool based on the most sophisticated governing equations has been developed. The governing equations involve Nernst-Planck equation with a convection term to follow ion movement and Poisson equation to follow potential development. The above tool is verified by comparing with analytical solutions and other researcher's results. The first simulation tool for CDI uses the decoupled implicit scheme: however, the scheme faces the numerical constraint of poor convergence. The maximum time step size is highly limited to 1.E-8s. Then an under-relaxation scheme is introduced with the limited success: we can increase its time step size by about 1,000 times higher than that of the decoupled scheme. Finally, the coupled implicit scheme, which solves the equations on concentration and potential simultaneously, is adopted. The newly developed scheme does not suffer from the convergence problem and is found to be optimal for CDI simulation. As the simulation domain, we select a region containing one pore and one electrode gap, to efficiently appreciate key parameters. Key performance indicator, KPI, and system parameters are determined. KPI is defined by the salt removal rate: salt removal amount per electrode volume divided by salt removal time taken

Robust, highly customizable, and economical multi-channel electrode for chronic multi-unit recording in behaving animals.

Science.gov (United States)

Tateyama, Yukina; Oyama, Kei; Shiraishi, Masaru; Iijima, Toshio; Tsutsui, Ken-Ichiro

2017-12-01

Multi-unit recording has been one of the most widely used techniques to investigate the correlation between multiple neuronal activities and behavior. However, a common problem of currently used multi-channel electrodes is their physical weakness. In this study, we developed a novel multi-channel electrode with sufficient physical strength to penetrate a thickened dura mater. This electrode consists of low-cost materials and is easily fabricated, and it enables recording without removing dura mater, thereby reducing the risk of inflammation, infection, or brain herniation. The low-cost multi-channel electrode developed in this study would be a useful tool for chronic recording in behaving animals. Copyright © 2017. Published by Elsevier B.V.

Development of a power electrode for plasma biasing on RFX

International Nuclear Information System (INIS)

Desideri, D.; Lorenzi, A. de; Zaccaria, P.

1999-01-01

A movable power electrode has been developed on the RFX experiment to modify the radial electric field at the edge of the plasma configuration. The electrode insertion head is a mushroom shaped limiter made of a carbon-carbon composite, and boron nitride is used as insulating material to be exposed to the plasma. The power electrode is designed to carry a 10 kA impulsive current and is insulated for 10 kV DC. The current into the electrode is driven by a power supply based on capacitor banks, and protective actions to cope with fault conditions have been implemented. The design of the electrode supporting structure has been done by using 3D finite element analyses, performed to evaluate the dynamic response of the system subjected to impulsive electromagnetic loads. The system has been used on the RFX experiment, showing the expected capability and flexibility. The current and voltage electrode waveforms are reported and discussed as far as the experimental results are concerned. Displacements of the electrode stiffening structure under electromagnetic load have been measured and compared to the numerical results. (orig.)

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.

Spraying Techniques for Large Scale Manufacturing of PEM-FC Electrodes

Science.gov (United States)

Hoffman, Casey J.

Fuel cells are highly efficient energy conversion devices that represent one part of the solution to the world's current energy crisis in the midst of global climate change. When supplied with the necessary reactant gasses, fuel cells produce only electricity, heat, and water. The fuel used, namely hydrogen, is available from many sources including natural gas and the electrolysis of water. If the electricity for electrolysis is generated by renewable energy (e.g., solar and wind power), fuel cells represent a completely 'green' method of producing electricity. The thought of being able to produce electricity to power homes, vehicles, and other portable or stationary equipment with essentially zero environmentally harmful emissions has been driving academic and industrial fuel cell research and development with the goal of successfully commercializing this technology. Unfortunately, fuel cells cannot achieve any appreciable market penetration at their current costs. The author's hypothesis is that: the development of automated, non-contact deposition methods for electrode manufacturing will improve performance and process flexibility, thereby helping to accelerate the commercialization of PEMFC technology. The overarching motivation for this research was to lower the cost of manufacturing fuel cell electrodes and bring the technology one step closer to commercial viability. The author has proven this hypothesis through a detailed study of two non-contact spraying methods. These scalable deposition systems were incorporated into an automated electrode manufacturing system that was designed and built by the author for this research. The electrode manufacturing techniques developed by the author have been shown to produce electrodes that outperform a common lab-scale contact method that was studied as a baseline, as well as several commercially available electrodes. In addition, these scalable, large scale electrode manufacturing processes developed by the author are

Development and characterisation of disposable gold electrodes, and their use for lead(II) analysis

Energy Technology Data Exchange (ETDEWEB)

Noh, Mohd F. M. [Cranfield University, Cranfield Health, Silsoe (United Kingdom); Institute for Medical Research, Toxicology and Pharmacology Unit, Herbal Medicine Research Centre, Kuala Lumpur (Malaysia); Tothill, Ibtisam E. [Cranfield University, Cranfield Health, Silsoe (United Kingdom)

2006-12-15

There is an increasing need to assess the harmful effects of heavy-metal-ion pollution on the environment. The ability to detect and measure toxic contaminants on site using simple, cost effective, and field-portable sensors is an important aspect of environmental protection and facilitating rapid decision making. A screen-printed gold sensor in a three-electrode configuration has been developed for analysis of lead(II) by square-wave stripping voltammetry (SWSV). The working electrode was fabricated with gold ink deposited by use of thick-film technology. Conditions affecting the lead stripping response were characterised and optimized. Experimental data indicated that chloride ions are important in lead deposition and subsequent analysis with this type of sensor. A linear concentration range of 10-50 {mu}g L{sup -1} and 25-300 {mu}g L{sup -1} with detection limits of 2 {mu}g L{sup -1} and 5.8 {mu}g L{sup -1} were obtained for lead(II) for measurement times of four and two minutes, respectively. The electrodes can be reused up to 20 times after cleaning with 0.5 mol L{sup -1} sulfuric acid. Interference of other metals with the response to lead were also examined to optimize the sensor response for analysis of environmental samples. The analytical utility of the sensor was demonstrated by applying the system to a variety of wastewater and soil sample extracts from polluted sites. The results are sufficient evidence of the feasibility of using these screen-printed gold electrodes for the determination of lead(II) in wastewater and soil extracts. For comparison purposes a mercury-film electrode and ICP-MS were used for validation. (orig.)

Binder-Free Graphene Organogels as Cost-Efficient Counter Electrodes for Dye-sensitized Solar Cells

International Nuclear Information System (INIS)

Pan, Dengyu; Feng, Chuanqi; Wang, Liang; Liu, Yuan; Chen, Zhiwen; Shi, Wenyan; Li, Zhen

2016-01-01

Graphene organogels (GOGs) filled with organic electrolytes may function as high-activity, low-cost electrodes for energy conversion and storage devices such as Li ion batteries, supercapacitors, and dye-sensitized solar cells (DSSCs), because of their ideal electron-transport and ion-diffusion pathways through an interconnected 3D porous framework self-assembled from highly conductive and high-specific-area graphene sheets. Here, graphene hydrogels prepared by a modified hydrothermal method are converted into organogels with a specific surface area up to ∼1298 m 2 g −1 by a simple solvent-exchange approach, and pressed onto titanium meshes to form GOG films as economical, wearable counter electrodes for DSSCs. Without optimizing TiO 2 photoanodes, GOG-based DSSCs show a markedly enhanced short-circuit current density (16.34 mA cm −2 ) and thus an impressive power conversion efficiency of 7.2%, higher than those using graphene aerogels (11.6 mA cm −2 , 5.9%) and commercial Pt films (10.2 mA cm −2 , 5.9%) as counter electrodes under otherwise identical conditions. The improved efficiency is ascribed to a substantial reduction in charge-transfer resistance and series resistance, which is correlated with the high conductivity and high specific area of GOGs.

Point-of-need simultaneous electrochemical detection of lead and cadmium using low-cost stencil-printed transparency electrodes.

Science.gov (United States)

Martín-Yerga, Daniel; Álvarez-Martos, Isabel; Blanco-López, M Carmen; Henry, Charles S; Fernández-Abedul, M Teresa

2017-08-15

In this work, we report a simple and yet efficient stencil-printed electrochemical platform that can be integrated into the caps of sample containers and thus, allows in-field quantification of Cd(II) and Pb(II) in river water samples. The device exploits the low-cost features of carbon (as electrode material) and paper/polyester transparency sheets (as substrate). Electrochemical analysis of the working electrodes prepared on different substrates (polyester transparency sheets, chromatographic, tracing and office papers) with hexaammineruthenium(III) showed that their electroactive area and electron transfer kinetics are highly affected by the porosity of the material. Electrodes prepared on transparency substrates showed the best electroanalytical performance for the simultaneous determination of Cd(II) and Pb(II) by square-wave anodic stripping voltammetry. Interestingly, the temperature and time at which the carbon ink was cured had significant effect on the electrochemical response, especially the capacitive current. The amount of Cd and Pb on the electrode surface can be increased about 20% by in situ electrodeposition of bismuth. The electrochemical platform showed a linear range comprised between 1 and 200 μg/L for both metals, sensitivity of analysis of 0.22 and 0.087 μA/ppb and limits of detection of 0.2 and 0.3 μg/L for Cd(II) and Pb(II), respectively. The analysis of river water samples was done directly in the container where the sample was collected, which simplifies the procedure and approaches field analysis. The developed point-of-need detection system allowed simultaneous determination of Cd(II) and Pb(II) in those samples using the standard addition method with precise and accurate results. Copyright © 2017 Elsevier B.V. All rights reserved.

Research and development of tungsten electrodes added with rare earth oxides

International Nuclear Information System (INIS)

Zuoren Nie; Ying Chen; Meiling Zhou; Tieyong Zuo

2001-01-01

The recent research and development of tungsten electrodes used in TIG and Plasma technologies are introduced, and the tungsten materials as well as the effects of rare earth oxides are specially discussed. in W-La 2 O 3 , W-CeO 2 , W-Y 2 O 3 and W-ThO 2 electrode materials, the W-2.2mass%La 2 O 3 electrode exhibited the best properties when the current is of little or middle volume, and when the electrodes are used in large current, the W-Y 2 O 3 electrode is the best. By a comparative study between the tungsten electrodes activated with single metal oxides, as above-mentioned, and those containing two or three rare earth oxides, namely La 2 O 3 , CeO 2 and Y 2 O 3 , it was indicated that the welding arc properties of the tungsten electrodes activated with combined rare earth oxides additions is superior than that of the electrodes containing single oxides as above mentioned. It was also shown that the operating properties of tungsten electrodes depend intensively on the rare earth oxides contained in the electrodes, and the actions of rare earth oxides during arcing are the most important factors to the electrodes' operating properties, temperature, work function as well as the arc stability. (author)

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.

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.

A cost-effective nanoporous ultrathin film electrode based on nanoporous gold/IrO2 composite for proton exchange membrane water electrolysis

Science.gov (United States)

Zeng, Yachao; Guo, Xiaoqian; Shao, Zhigang; Yu, Hongmei; Song, Wei; Wang, Zhiqiang; Zhang, Hongjie; Yi, Baolian

2017-02-01

A cost-effective nanoporous ultrathin film (NPUF) electrode based on nanoporous gold (NPG)/IrO2 composite has been constructed for proton exchange membrane (PEM) water electrolysis. The electrode was fabricated by integrating IrO2 nanoparticles into NPG through a facile dealloying and thermal decomposition method. The NPUF electrode is featured in its 3D interconnected nanoporosity and ultrathin thickness. The nanoporous ultrathin architecture is binder-free and beneficial for improving electrochemical active surface area, enhancing mass transport and facilitating releasing of oxygen produced during water electrolysis. Serving as anode, a single cell performance of 1.728 V (@ 2 A cm-2) has been achieved by NPUF electrode with a loading of IrO2 and Au at 86.43 and 100.0 μg cm-2 respectively, the electrolysis voltage is 58 mV lower than that of conventional electrode with an Ir loading an order of magnitude higher. The electrolysis voltage kept relatively constant up to 300 h (@250 mA cm-2) during the course of durability test, manifesting that NPUF electrode is promising for gas evolution.

Low-cost carbon-based counter electrodes for dye sensitized solar cells

International Nuclear Information System (INIS)

Barberio, M; Imbrogno, A; Bonanno, A; Xu, F; Grosso, D R

2015-01-01

In this work, we present the realization of four carbon-based counter electrodes for dye-sensitized solar cells. The photovoltaic behaviours of counter electrodes realized with graphene, multiwalled carbon nanotubes, and nanocomposites of multiwalled carbon nanotubes and metal nanoparticles are compared with those of classical electrodes (amorphous carbon and platinum). Our results show an increase of about 50% in PCE for graphene and Ag/carbon nanotube electrodes with respect to amorphous carbon and of 25% in comparison to platinum. An improvement in cell stability is also observed; in fact, the PCE of all carbon-based cells assumes a constant value during a period of one month while that with the Pt electrode decreases by 50% in one week. (paper)

An overview of technology and research in electrode design and manufacturing in sinking electrical discharge machining

Directory of Open Access Journals (Sweden)

Bhola Jha

2014-06-01

Full Text Available Electrical discharge machining (EDM is one of the earliest non-traditional machining processes, based on thermoelectric energy between the workpiece and an electrode. In this process, the material is removed electro thermally by a series of successive discrete discharges between two electrically conductive objects, i.e., the electrode and the workpiece. The performance of the process, to a large extent, depends on the material, design and manufacturing method of the electrodes. Electrode design and method of its manufacturing also affect on the cost of electrode. Researchers have explored a number of ways to improve electrode design and devised various ways of manufacturing. The paper reports a review on the research relating to EDM electrode design and its manufacturing for improving and optimizing performance measures and reducing time and cost of manufacturing. The final part of the paper discusses these developments and outlines the trends for future research work.

Development of technology for thin substrate polycrystalline solar cells for practical use. Development of elementary technologies for low-cost polycrystalline cell modules; Usugata takessho taiyo denchi seizo gijutsu no jitsuyoka kenkyu. Takessho cell module tei cost ka yoso gijutsu kaihatsu

Energy Technology Data Exchange (ETDEWEB)

Tatsuta, M [New Energy and Industrial Technology Development Organization, Tokyo (Japan)

1994-12-01

This paper reports the study results on development of elementary technologies for low-cost polycrystalline cell modules in fiscal 1994. (1) On development of elementary technologies for mass production, fast surface machining, fast electrode forming and fast forming of junctions and antireflection films were studied. Surface machining by rotating grindstone was studied as fast cutting of fine grooves on Si substrates, resulting in possible fast machining superior in shape accuracy. Electrode properties equivalent or superior to previous ones were obtained by fast electrode forming using a fast printing/sintering equipment even at transfer speed 7.5 times as high as that of conventional methods. Simultaneous fast forming of junctions and antireflection films were achieved by heat treatment after deposition on Si substrate surfaces while heat-decomposing Ti and P compound gas. (2) On development of module structure, an optimum cell group angle, low reflection rate at glass surface, and fast wiring were studied. 5 figs., 2 tabs.

Development of Polybenzimidazole-Based High-Temperature Membrane and Electrode Assemblies for Stationary and Automotive Applications

Energy Technology Data Exchange (ETDEWEB)

Vogel, John A.

2008-09-03

The program began on August 1, 2003 and ended on July 31, 2007. The goal of the project was to optimize a high-temperature polybenzimidazole (PBI) membrane to meet the performance, durability, and cost targets required for stationary fuel cell applications. These targets were identified in the Fuel Cell section (3.4) of DOE’s Hydrogen, Fuel Cells and Infrastructure Technologies Program Multi-Year Research, Development and Demonstration Plan. A membrane that operates at high temperatures is important to the fuel cell industry because it is insensitive to carbon monoxide (a poison to low-temperature fuel cells), and does not require complex water management strategies. Together, these two benefits greatly simplify the fuel cell system. As a result, the high-temperature fuel cell system realizes a cost benefit as the number of components is reduced by nearly 30%. There is also an inherent reliability benefit as components such as humidifiers and pumps for water management are unnecessary. Furthermore, combined heat and power (CHP) systems may be the best solution for a commercial, grid-connected, stationary product that must offer a cost benefit to the end user. For a low-temperature system, the quality of the heat supplied is insufficient to meet consumer needs and comfort requirements, so peak heaters or supplemental boilers are required. The higher operating temperature of PBI technology allows the fuel cell to meet the heat and comfort demand without the additional equipment. Plug Power, working with the Rensselaer Polytechnic Institute (RPI) Polymer Science Laboratory, made significant advances in optimizing the PBI membrane material for operation at temperatures greater than 160oC with a lifetime of 40,000 hours. Supporting hardware such as flow field plates and a novel sealing concept were explored to yield the lower-cost stack assembly and corresponding manufacturing process. Additional work was conducted on acid loss, flow field design and cathode electrode

Development of a membrane electrode assembly process for proton exchange membrane fuel cell (PEMFC)

International Nuclear Information System (INIS)

Baldo, Wilians Roberto

2003-01-01

In this work, a Membrane Electrode Assembly (MEA) producing process was developed, involving simple steps, aiming cost reduction and good reproducibility for Proton Exchange Membrane Fuel Cell (PEMFC) commercial applications. The electrodes were produced by spraying ink into both sides of the polymeric membrane, building the catalytic layers, followed by hot pressing of Gas Diffusion Layers (GDL), forming the MEA. This new producing method was called 'Spray and hot pressing hybrid method'. Concerning that all the parameters of spray and hot pressing methods are interdependent, a statistical procedure were used in order to study the mutual variables influences and to optimize the method. This study was earned out in two distinct steps: the first one, where seven variables were considered for the analysis and the second one, where only the variables that interfered in the process performance in the first step were considered for analysis. The results showed that the developed process was adequate, including only simple steps, reaching MEA's performance of 651 m A cm -2 at a potential of 600 mV for catalysts loading of 0,4 mg cm -2 Pt at the anode and 0,6 mg cm -2 Pt at the cathode. This result is compared to available commercial MEA's, with the same fuel cell operations conditions. (author)

Contact engineering for efficient charge injection in organic transistors with low-cost metal electrodes

Science.gov (United States)

Panigrahi, D.; Kumar, S.; Dhar, A.

2017-10-01

Controlling charge injection at the metal-semiconductor interface is very crucial for organic electronic devices in general as it can significantly influence the overall device performance. Herein, we report a facile, yet efficient contact modification approach, to enhance the hole injection efficiency through the incorporation of a high vacuum deposited TPD [N,N'-Bis(3-methylphenyl)-N,N'-diphenylbenzidine] interlayer between the electrodes and the active semiconducting layer. The device performance parameters such as mobility and on/off ratio improved significantly after the inclusion of the TPD buffer layer, and more interestingly, the devices with cost effective Ag and Cu electrodes were able to exhibit a superior device performance than the typically used Au source-drain devices. We have also observed that this contact modification technique can be even more effective than commonly used metal oxide interface modifying layers. Our investigations demonstrate the efficacy of the TPD interlayer in effectively reducing the interfacial contact resistance through the modification of pentacene energy levels, which consequently results in the substantial improvement in the device performances.

The operating cost of electrocoagulation

Energy Technology Data Exchange (ETDEWEB)

Donini, J.C.; Kan, J.; Szynkarczuk, J.; Hassan, T.A.; Kar, K.L. (Canadian Centre for Mineral and Energy Technology, Devon, AB (Canada))

1994-12-01

The electrocoagulation of kaolinite and bentonite suspensions was studied in a pilot-scale electrocoagulation system to assess the operating cost and efficiency of the process. Factors affecting the operating cost such as formation of passivation layers on electrode plates, flow velocity, and concentration of NaCl in the suspension were examined. The operating costs investigated were the power cost of the electrocoagulation cell and the material cost due to the consumption of the aluminum electrode. Comparison was based on the settling properties of the treated product: turbidity, settling rate, and cake height. Higher NaCl concentration resulted in greater amounts of Al dissolved chemically and electrochemically into the suspension and thus a better clarity of the supernatant of the treated product. Increased flow velocity could reduce significantly the operating cost while improving both clarity of the supernatant and compactness of the sludge volume. The passivation layers developed quickly with time during the electrocoagulation process and more energy became wasted on the layers. 10 refs., 12 figs.

RuO₂ pH Sensor with Super-Glue-Inspired Reference Electrode.

Science.gov (United States)

Lonsdale, Wade; Wajrak, Magdalena; Alameh, Kamal

2017-09-06

A pH-sensitive RuO₂ electrode coated in a commercial cyanoacrylate adhesive typically exhibits very low pH sensitivity, and could be paired with a RuO₂ working electrode as a differential type pH sensor. However, such sensors display poor performance in real sample matrices. A pH sensor employing a RuO₂ pH-sensitive working electrode and a SiO₂-PVB junction-modified RuO₂ reference electrode is developed as an alternative high-performance solution. This sensor exhibits a performance similar to that of a commercial glass pH sensor in some common sample matrices, particularly, an excellent pH sensitivity of 55.7 mV/pH, a hysteresis as low as 2.7 mV, and a drift below 2.2 mV/h. The developed sensor structure opens the way towards the development of a simple, cost effective, and robust pH sensor for pH analysis in various sample matrices.

The Electrode Modality Development in Pulsed Electric Field Treatment Facilitates Biocellular Mechanism Study and Improves Cancer Ablation Efficacy.

Science.gov (United States)

Cen, Chao; Chen, Xinhua

2017-01-01

Pulsed electric field treatment is now widely used in diverse biological and medical applications: gene delivery, electrochemotherapy, and cancer therapy. This minimally invasive technique has several advantages over traditional ablation techniques, such as nonthermal elimination and blood vessel spare effect. Different electrodes are subsequently developed for a specific treatment purpose. Here, we provide a systematic review of electrode modality development in pulsed electric field treatment. For electrodes invented for experiment in vitro, sheet electrode and electrode cuvette, electrodes with high-speed fluorescence imaging system, electrodes with patch-clamp, and electrodes with confocal laser scanning microscopy are introduced. For electrodes invented for experiment in vivo, monopolar electrodes, five-needle array electrodes, single-needle bipolar electrode, parallel plate electrodes, and suction electrode are introduced. The pulsed electric field provides a promising treatment for cancer.

Development of more efficient and cheaper MEA's for PEM fuel cells; Membrane-electrode-assembly

Energy Technology Data Exchange (ETDEWEB)

Yde Andersen, S. (IRD Fuel Cell A/S, Svendborg (Denmark)); Nilsson, M.S. (Danish Power System Aps, Charlottenlund (Denmark)); Siu, A.; Plackett, D. (Technical Univ. of Denmark. Risoe National Lab. for Sustainable Energy, Dansk Polymer Center, Roskilde (Denmark)); Li, Q. (Technical Univ. of Denmark, Dept. of Chemistry, Kgs. Lyngby (Denmark))

2008-06-15

The project covered 5 main areas: 1) polymer and membranes; 2) electrocatalysts; 3) gas diffusion electrodes; 4) MEAs; and 5) evaluation techniques. For the polymers, by purification of monomers and optimizing parameters, high molecular weight polybenzimidazoles have been synthesized in batches of 50 g with good reproducibility. Based on the polymer, two types of new membranes have been prepared. One is the cross-linked (covalently and acid-base) PBI blend membranes. The blend membranes were systematically characterized and show excellent properties such as very high acid doping levels, conductivity, mechanical strength and durability. The other type is composite membranes based on PBI and nanoclay. Using the modified nanoclay, good dispersion and transparent composite membranes have been achieved. For catalyst preparation, the carbon supports have been modified with thermal treatment. Improved corrosion resistance was achieved with little sacrificing of the catalytic activity. High Pt loading catalysts were prepared, based on which high performance gas diffusion electrodes were fabricated. The performance target of both cathode and anode was achieved, as evaluated by the PTFE half cell tests. New gas diffusion layer (GDL) materials have been developed and tested in different MEA configurations. Significant performance improvement has been achieved with also potential to reduce the cost. Techniques for applying micro porous layers and catalyst layers have been optimized, including tape casting, spraying, and catalyst-coated membrane (CCM). Using the developed membranes and gas diffusion electrodes, membrane-electrode assemblies (MEAs) were fabricated for both single cell and stack tests. Selection of sealing materials and design of integrated gaskets have been made for both low and high temperature MEAs. Parameters for hot-pressing such as temperature, pressure and duration were systematically studied. 44 MEAs with an active area of 256 cm{sup 2} have been prepared

Development of large area resistive electrodes for ATLAS NSW Micromegas

Science.gov (United States)

Ochi, Atsuhiko

2018-02-01

Micromegas with resistive anodes will be used for the NSW upgrades of the ATLAS experiment at LHC. Resistive electrodes are used in MPGD devices to prevent sparks in high-rate operation. Large-area resistive electrodes for Micromegas have been developed using two different technologies: screen printing and carbon sputtering. The maximum resistive foil size is 45 × 220 cm with a printed pattern of 425-μm pitch strips. These technologies are also suitable for mass production. Prototypes of a production model series have been successfully produced. In this paper, we report the development, the production status, and the test results of resistive Micromegas.

A novel method of fabricating carbon nanotubes-polydimethylsiloxane composite electrodes for electrocardiography.

Science.gov (United States)

Liu, Benyan; Chen, Yingmin; Luo, Zhangyuan; Zhang, Wenzan; Tu, Quan; Jin, Xun

2015-01-01

Polymer-based flexible electrodes are receiving much attention in medical applications due to their good wearing comfort. The current fabrication methods of such electrodes are not widely applied. In this study, polydimethylsiloxane (PDMS) and conductive additives of carbon nanotubes (CNTs) were employed to fabricate composite electrodes for electrocardiography (ECG). A three-step dispersion process consisting of ultrasonication, stirring, and in situ polymerization was developed to yield homogenous CNTs-PDMS mixtures. The CNTs-PDMS mixtures were used to fabricate CNTs-PDMS composite electrodes by replica technology. The influence of ultrasonication time and CNT concentration on polymer electrode performance was evaluated by impedance and ECG measurements. The signal amplitude of the electrodes prepared using an ultrasonication time of 12 h and CNT content of 5 wt% was comparable to that of commercial Ag/AgCl electrodes. The polymer electrodes were easily fabricated by conventional manufacturing techniques, indicating a potential advantage of reduced cost for mass production.

Development of an integrated, in-situ remediation technology. Topical report for task No. 5: Cost analysis, September 26, 1994--May 25, 1996

International Nuclear Information System (INIS)

Quinton, G.; Schultz, D.; Landis, R.

1997-01-01

Contamination in low permeability soils poses a significant technical challenge to in situ remediation efforts. Poor accessibility to the contaminants and difficulty in delivering treatment reagents have rendered existing in situ treatments such as bioremediation, vapor extraction, pump and treat rather ineffective when applied to low permeability soils present at many contaminated sites. The Lasagna trademark technology is an integrated in situ treatment in which established geotechnical methods are used to install degradation zones directly into the contaminated soil and electro-osmosis if utilized to move the contaminants back and forth through those zones until the treatment is completed. This topical report presents the results of an engineering evaluation and cost analysis of the vertically configured treatment process completed by the DuPont Company. The cost evaluation was prepared by developing a cost optimization model of the overall treatment process. This model considers various input parameters such as soil properties, depth of contamination, cost for emplacing electrodes and treatment zones, required purge water volume, time constraints to achieve cleanup, and cost of power. Several example cases were run using the cost model to provide representative cost ranges for applying the technology to clean up trichloroethene contamination in clay. These costs are estimated to range from $40 to $95 per cubic yard of soil for a 1-acre site, with cost depending on depth of contamination (cost range valid from 15 to 45 ft), method of electrode/treatment zone emplacement (cost range valid from 15 to 45 ft), method of electrode/treatment zone emplacement (cost range valid for Lasagna trademark Phase I emplacement and optimized emplacement techniques), and time available to complete remediation (cost range valid for one- and three-year timeframe)

Polyanion-Type Electrode Materials for Sodium-Ion Batteries.

Science.gov (United States)

Ni, Qiao; Bai, Ying; Wu, Feng; Wu, Chuan

2017-03-01

Sodium-ion batteries, representative members of the post-lithium-battery club, are very attractive and promising for large-scale energy storage applications. The increasing technological improvements in sodium-ion batteries (Na-ion batteries) are being driven by the demand for Na-based electrode materials that are resource-abundant, cost-effective, and long lasting. Polyanion-type compounds are among the most promising electrode materials for Na-ion batteries due to their stability, safety, and suitable operating voltages. The most representative polyanion-type electrode materials are Na 3 V 2 (PO 4 ) 3 and NaTi 2 (PO 4 ) 3 for Na-based cathode and anode materials, respectively. Both show superior electrochemical properties and attractive prospects in terms of their development and application in Na-ion batteries. Carbonophosphate Na 3 MnCO 3 PO 4 and amorphous FePO 4 have also recently emerged and are contributing to further developing the research scope of polyanion-type Na-ion batteries. However, the typical low conductivity and relatively low capacity performance of such materials still restrict their development. This paper presents a brief review of the research progress of polyanion-type electrode materials for Na-ion batteries, summarizing recent accomplishments, highlighting emerging strategies, and discussing the remaining challenges of such systems.

Development of a new all solid contact Cs"+ ion selective electrode

International Nuclear Information System (INIS)

Ramanjaneyulu, P.S.; Abha Naveen Kumar; Sharma, M.K.

2017-01-01

Studies were carried out to develop all solid contact cesium ion selective electrode with 25,27-bis(1-octyloxy)calix[4]arene-crown-6 as an ionophore. Polyaniline (PANI), deposited on Pt electrode by electrochemical method, was used as a transducer. Three different types of electrodes were made with variation in thickness of PANI film and gold nanoparticles doped PANI as transducers. The best response was observed with ISE having Au nanoparticles doped PANI as a transducer. The optimised ISE gave Nernstian response in the range 10"-"7 to 10"-"2 M with the slope of 55.0 ± 0.6 mV/decade of Cs"+. The response of ISE for Cs"+ is fairly constant above the pH 4. The developed ISE was successfully employed to determine Cs"+ in simulated high level nuclear waste solutions and CsCl spiked tap water samples. (author)

Development of a Micro-Fiber Nickel Electrode for Nickel-Hydrogen Cell

Science.gov (United States)

Britton, Doris L.

1996-01-01

The development of a high specific energy battery is one of the objectives of the lightweight nickel-hydrogen (NiH2) program at the NASA Lewis Research Center. The approach has been to improve the nickel electrode by continuing combined in-house and contract efforts to develop a more efficient and lighter weight electrode for the nickel-hydrogen fuel cell. Small fiber diameter nickel plaques are used as conductive supports for the nickel hydroxide active material. These plaques are commercial products and have an advantage of increased surface area available for the deposition of active materials. Initial tests include activation and capacity measurements at different discharge levels followed by half-cell cycle testing at 80 percent depth-of-discharge in a low Earth orbit regime. The electrodes that pass the initial tests are life cycle tested in a boiler plate nickel-hydrogen cell before flightweight designs are built and tested.

Biotechnology humic acids-based electrospun carbon nanofibers as cost-efficient electrodes for lithium-ion batteries

International Nuclear Information System (INIS)

Zhao, Pin-Yi; Guo, Yan; Yu, Bao-Jun; Zhang, Jie; Wang, Cheng-Yang

2016-01-01

Bio-based, cost-effective carbon nanofibers are fabricated from polyacrylonitrile (PAN) – refined biotechnology humic acids (RB) via simple eletrospinning after stabilization and carbonization. The influence of PAN/RB mass ratios and heat-treatment temperatures (HTTs) on structure and morphology is systematically studied. Excitingly, a first discharge/charge capacity of 937.9/613.4 mAh g −1 (coulombic efficiency of 65.4%) is achieved at 20 mA g −1 for PB7/3-800 in lithium-ion batteries (LIBs). Meanwhile, a charge capacity of 348.2 mAh g −1 (about 89% retention ratio) remains even after 100 cycles at 0.1 A g −1 . It is demonstrated that biomass humic acids can be applied as a promising precursor to fabricate high performance, low-cost, as well as “green” carbon electrode material for LIBs.

RuO2 pH Sensor with Super-Glue-Inspired Reference Electrode

Directory of Open Access Journals (Sweden)

Wade Lonsdale

2017-09-01

Full Text Available A pH-sensitive RuO2 electrode coated in a commercial cyanoacrylate adhesive typically exhibits very low pH sensitivity, and could be paired with a RuO2 working electrode as a differential type pH sensor. However, such sensors display poor performance in real sample matrices. A pH sensor employing a RuO2 pH-sensitive working electrode and a SiO2-PVB junction-modified RuO2 reference electrode is developed as an alternative high-performance solution. This sensor exhibits a performance similar to that of a commercial glass pH sensor in some common sample matrices, particularly, an excellent pH sensitivity of 55.7 mV/pH, a hysteresis as low as 2.7 mV, and a drift below 2.2 mV/h. The developed sensor structure opens the way towards the development of a simple, cost effective, and robust pH sensor for pH analysis in various sample matrices.

RuO2 pH Sensor with Super-Glue-Inspired Reference Electrode

Science.gov (United States)

Wajrak, Magdalena; Alameh, Kamal

2017-01-01

A pH-sensitive RuO2 electrode coated in a commercial cyanoacrylate adhesive typically exhibits very low pH sensitivity, and could be paired with a RuO2 working electrode as a differential type pH sensor. However, such sensors display poor performance in real sample matrices. A pH sensor employing a RuO2 pH-sensitive working electrode and a SiO2-PVB junction-modified RuO2 reference electrode is developed as an alternative high-performance solution. This sensor exhibits a performance similar to that of a commercial glass pH sensor in some common sample matrices, particularly, an excellent pH sensitivity of 55.7 mV/pH, a hysteresis as low as 2.7 mV, and a drift below 2.2 mV/h. The developed sensor structure opens the way towards the development of a simple, cost effective, and robust pH sensor for pH analysis in various sample matrices. PMID:28878182

Progress in the Development of Lightweight Nickel Electrode for Nickel-Hydrogen Cell

Science.gov (United States)

Britton, Doris L.

1999-01-01

Development of a high specific energy battery is one of the objectives of the lightweight nickel-hydrogen (Ni-H2) program at the NASA Glenn Research Center. The approach has been to improve the nickel electrode by continuing combined in-house and contract efforts to develop a lighter weight electrode for the nickel-hydrogen cell. Small fiber diameter nickel plaques are used as conductive supports for the nickel hydroxide active material. These plaques are commercial products and have an advantage of increased surface area available for the deposition of active material. Initial tests include activation and capacity measurements at five different discharge levels, C/2, 1.0 C, 1.37 C, 2.0 C, and 2.74 C. The electrodes are life cycle tested using a half-cell configuration at 40 and 80% depths-of-discharge (DOD) in a low-Earth-orbit regime. The electrodes that pass the initial tests are life cycle-tested in a boiler plate nickel-hydrogen cell before flight weight design are built and tested.

Development of materials for open-cycle magnetohydrodynamics (MHD): ceramic electrode. Final report

Energy Technology Data Exchange (ETDEWEB)

Bates, J.L.; Marchant, D.D.

1986-09-01

Pacific Northwest Laboratory, supported by the US Department of Energy, developed advanced materials for use in open-cycle, closed cycle magnetohydrodynamics (MHD) power generation, an advanced energy conversion system in which the flow of electrically conducting fluid interacts with an electric field to convert the energy directly into electricity. The purpose of the PNL work was to develop electrodes for the MHD channel. Such electrodes must have: (1) electrical conductivity above 0.01 (ohm-cm)/sup -1/ from near room temperature to 1900/sup 0/K, (2) resistance to both electrochemical and chemical corrosion by both slag and potassium seed, (3) resistance to erosion by high-velocity gases and particles, (4) resistance to thermal shock, (5) adequate thermal conductivity, (6) compatibility with other channel components, particularly the electrical insulators, (7) oxidation-reduction stability, and (8) adequate thermionic emission. This report describes the concept and development of high-temperature, graded ceramic composite electrode materials and their electrical and structural properties. 47 refs., 16 figs., 13 tabs.

Development of Iridium Solid-state Reference Electrode for the Water Chemistry Status Measurement in Nuclear Power Plants

International Nuclear Information System (INIS)

Ku, Heekwon; Lim, Dongseok; Cho, Jaeseon

2013-01-01

The result of ECP measurement of piping material in nuclear power plant at low temperature using the developed iridium (SSRE) reference electrode is approximately -0.370V. Based on the various results of this study, the developed iridium (SSRE) reference electrode can be applied to the water chemistry environments of nuclear power plant. Various metallic materials used in a nuclear power plant have been exposed to a variety of water chemistry environments and the corrosion of metallic materials occurs due to the reactions between metal structures and water chemistry environments. Therefore, the management of the water chemistry factors is needed to prevent corrosion. The chemical factors affecting the corrosion are pH and Electrochemical Corrosion Potential (ECP). The world-wide studies suggest that ECP and pH are effective indicators for preventing the material damage from water chemistry condition. ECP and pH should be measured as the reference electrodes, and should show stable potential characteristics with fast responses. In this study, the iridium reference electrodes using a solid-state metal oxide electrode has been developed to measure effective indicators such as ECP and pH. The iridium (SSRE) reference electrode for the ECP measurement in water chemistry environment of nuclear power plants has been developed. A calibration for water chemistry measurement was performed by potential measurement of iridium (SSRE) reference electrode with Ag/AgCl (SSRE) reference electrode. The result exhibited a stable potential for 117 hours and a super-Nernst ian response with 63.12mV/p H. In this study, the iridium (SSRE) reference electrode shows super-Nernst ian characteristic and it may be caused by the property of electrolytically coated iridium oxide. Considering the long-term stability of the developed electrode, it is possible to apply as a reference electrode through calibration procedure

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

Directory of Open Access Journals (Sweden)

Akira Ichikawa

2013-02-01

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

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.

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.

A top-down approach for fabricating free-standing bio-carbon supercapacitor electrodes with a hierarchical structure

OpenAIRE

Yingzhi Li; Qinghua Zhang; Junxian Zhang; Lei Jin; Xin Zhao; Ting Xu

2015-01-01

Biomass has delicate hierarchical structures, which inspired us to develop a cost-effective route to prepare electrode materials with rational nanostructures for use in high-performance storage devices. Here, we demonstrate a novel top-down approach for fabricating bio-carbon materials with stable structures and excellent diffusion pathways; this approach is based on carbonization with controlled chemical activation. The developed free-standing bio-carbon electrode exhibits a high specific ca...

Nanostructured manganese oxide thin films as electrode material for supercapacitors

Science.gov (United States)

Xia, Hui; Lai, Man On; Lu, Li

2011-01-01

Electrochemical capacitors, also called supercapacitors, are alternative energy storage devices, particularly for applications requiring high power densities. Recently, manganese oxides have been extensively evaluated as electrode materials for supercapacitors due to their low cost, environmental benignity, and promising supercapacitive performance. In order to maximize the utilization of manganese oxides as the electrode material for the supercapacitors and improve their supercapacitive performance, the nanostructured manganese oxides have therefore been developed. This paper reviews the synthesis of the nanostructured manganese oxide thin films by different methods and the supercapacitive performance of different nanostructures.

Development of large area resistive electrodes for ATLAS NSW MicroMEGAS

CERN Document Server

Ochi, Atsuhiko; The ATLAS collaboration

2015-01-01

MicroMegas with resistive anode will be used for the NSW upgrade of the ATLAS experiment at LHC. The resistive electrode is one of key technology for MPGDs to prevent sparks. Large area resistive electrodes for the MM have been developed using two different technology; screen printing and carbon sputtering. Maximum size of each resistive foil is 45cm x 220cm with printed pattern of 425 micron pitch strips. Those technologies are also suitable to mass production. The prototypes of series production model have been produced successfully. We will report the development and production status and test results of the resistive MicroMegas.

Reducing electrocoagulation harvesting costs for practical microalgal biodiesel production.

Science.gov (United States)

Dassey, Adam J; Theegala, Chandra S

2014-01-01

Electrocoagulation has shown potential to be a primary microalgae harvesting technique for biodiesel production. However, methods to reduce energy and electrode costs are still necessary for practical application. Electrocoagulation tests were conducted on Nannochloris sp. and Dunaliella sp. using perforated aluminium and iron electrodes under various charge densities. Aluminium electrodes were shown to be more efficient than iron electrodes when harvesting both algal species. Despite the lower harvesting efficiency, however, the iron electrodes were more energy and cost efficient. Operational costs of less than $0.03/L oil were achieved when harvesting Nannochloris sp. with iron electrodes at 35% harvest efficiency, whereas aluminium electrodes cost $0.75/L oil with 42% harvesting efficiency. Increasing the harvesting efficiencies for both aluminium and iron electrodes also increased the overall cost per litre of oil, therefore lower harvesting efficiencies with lower energy inputs was recommended. Also, increasing the culturing salinity to 2 ppt sodium chloride for freshwater Nannochloris sp. was determined practical to improve the electrocoagulation energy efficiency despite a 25% reduction in cell growth.

Ultrasmooth, extremely deformable and shape recoverable Ag nanowire embedded transparent electrode.

Science.gov (United States)

Nam, Sanggil; Song, Myungkwan; Kim, Dong-Ho; Cho, Byungjin; Lee, Hye Moon; Kwon, Jung-Dae; Park, Sung-Gyu; Nam, Kee-Seok; Jeong, Yongsoo; Kwon, Se-Hun; Park, Yun Chang; Jin, Sung-Ho; Kang, Jae-Wook; Jo, Sungjin; Kim, Chang Su

2014-04-25

Transparent electrodes have been widely used in electronic devices such as solar cells, displays, and touch screens. Highly flexible transparent electrodes are especially desired for the development of next generation flexible electronic devices. Although indium tin oxide (ITO) is the most commonly used material for the fabrication of transparent electrodes, its brittleness and growing cost limit its utility for flexible electronic devices. Therefore, the need for new transparent conductive materials with superior mechanical properties is clear and urgent. Ag nanowire (AgNW) has been attracting increasing attention because of its effective combination of electrical and optical properties. However, it still suffers from several drawbacks, including large surface roughness, instability against oxidation and moisture, and poor adhesion to substrates. These issues need to be addressed before wide spread use of metallic NW as transparent electrodes can be realized. In this study, we demonstrated the fabrication of a flexible transparent electrode with superior mechanical, electrical and optical properties by embedding a AgNW film into a transparent polymer matrix. This technique can produce electrodes with an ultrasmooth and extremely deformable transparent electrode that have sheet resistance and transmittance comparable to those of an ITO electrode.

Development of reliable lithium microreference electrodes for long-term in situ studies of lithium-based battery systems

NARCIS (Netherlands)

Zhou, J.; Notten, P.H.L.

2004-01-01

An in situ method to prepare lithium microreference electrodes has been developed. The microreference electrodes are made by electrochemical deposition of metallic lithium from both the positive and negative electrodes onto a copper wire positioned in-between the two Li-based battery electrodes. The

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.

Study and Fabrication of Super Low-Cost Solar Cell (SLC-SC) Based on Counter Electrode from Animal’s Bone

Science.gov (United States)

Fadlilah, D. R.; Fajar, M. N.; Aini, A. N.; Haqqiqi, R. I.; Wirawan, P. R.; Endarko

2018-04-01

The synthesized carbon from bones of chicken, cow, and fish with the calcination temperature at 450 and 600°C have been successfully fabricated for counter electrode in the Super Low-Cost Solar Cell (SLC-LC) based the structure of Dye-Sensitized Solar Cells (DSSC). The main proposed study was to fabricate SLC-SC and investigate the influence of the synthesized carbon from animal’s bone for counter electrode towards to photovoltaic performance of SLC-SC. X-Ray Diffraction and UV-Vis was used to characterize the phase and the optical properties of TiO2 as photoanode in SLC-SC. Meanwhile, the morphology and particle size distribution of the synthesized carbon in counter electrodes were investigated by Scanning Electron Microscopy (SEM) and Particle Size Analyzer (PSA). The results showed that the TiO2 has anatase phase with the absorption wavelength of 300 to 550 nm. The calcination temperature for synthesizing of carbon could affect morphology and particle size distribution. The increasing temperature gave the effect more dense in morphology and increased the particle size of carbon in the counter electrode. Changes in morphology and particle size of carbon give effect to the performance of the SLC-SC where the increased morphology’s compact and particle size make decreased in the performance of the SLC-SC.

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.

Carbon nanotube/polymer composite electrodes for flexible, attachable electrochemical DNA sensors.

Science.gov (United States)

Li, Jianfeng; Lee, Eun-Cheol

2015-09-15

All-solution-processed, easily-made, flexible multi-walled carbon nanotube (MWCNT)/polydimethylsiloxane (PDMS)-based electrodes were fabricated and used for electrochemical DNA sensors. These electrodes could serve as a recognition layer for DNA, without any surface modification, through π-π interactions between the MWCNTs and DNA, greatly simplifying the fabrication process for DNA sensors. The electrodes were directly connected to an electrochemical analyzer in the differential pulse voltammetry (DPV) and cyclic voltammetry (CV) measurements, where methylene blue was used as a redox indicator. Since neither functional groups nor probe DNA were immobilized on the surfaces of the electrodes, the sensor can be easily regenerated by washing these electrodes with water. The limit of detection was found to be 1.3 × 10(2)pM (S/N=3), with good DNA sequence differentiation ability. Fast fabrication of a DNA sensor was also achieved by cutting and attaching the MWCNT-PDMS composite electrodes at an analyte solution-containable region. Our results pave the way for developing user-fabricated easily attached DNA sensors at low costs. Copyright © 2015 Elsevier B.V. All rights reserved.

Transparent Electrodes: A Review of the Use of Carbon-Based Nanomaterials

Directory of Open Access Journals (Sweden)

Edgar J. López-Naranjo

2016-01-01

Full Text Available Transparent conducting electrodes (TCE are extensively applied in a great range of optoelectronic and photovoltaic equipment (e.g., solar cells, touch panels, and flexible devices. Carbon-based nanomaterials are considered as suitable replacements to substitute traditional materials to manufacture TCE due to their remarkable characteristics, for example, high optical transmittance and outstanding electrical properties. In comparison with traditional indium tin oxide electrodes, carbon-based electrodes show good mechanical properties, chemical stability, and low cost. Nevertheless, major issues related to the development of good quality manufacture methods to produce carbon-based nanomaterials have to be overcome to meet massive market requirements. Hence, the development of alternative TCE materials as well as appropriate large production techniques that meet the requirements of a proper sheet resistance along with a high optical transparency is a priority. Therefore, in this work, we summarize and discuss novel production and synthesis methods, chemical treatments, and hybrid materials developed to satisfy the worldwide request for carbon-based nanomaterials.

Innovative manufacturing and materials for low cost lithium ion batteries

Energy Technology Data Exchange (ETDEWEB)

Carlson, Steven [Optodot Corporation, Woburn, MA (United States)

2015-12-29

This project demonstrated entirely new manufacturing process options for lithium ion batteries with major potential for improved cost and performance. These new manufacturing approaches are based on the use of the new electrode-coated separators instead of the conventional electrode-coated metal current collector foils. The key enabler to making these electrode-coated separators is a new and unique all-ceramic separator with no conventional porous plastic separator present. A simple, low cost, and high speed manufacturing process of a single coating of a ceramic pigment and polymer binder onto a re-usable release film, followed by a subsequent delamination of the all-ceramic separator and any layers coated over it, such as electrodes and metal current collectors, was utilized. A suitable all-ceramic separator was developed that demonstrated the following required features needed for making electrode-coated separators: (1) no pores greater than 100 nanometer (nm) in diameter to prevent any penetration of the electrode pigments into the separator; (2) no shrinkage of the separator when heated to the high oven heats needed for drying of the electrode layer; and (3) no significant compression of the separator layer by the high pressure calendering step needed to densify the electrodes by about 30%. In addition, this nanoporous all-ceramic separator can be very thin at 8 microns thick for increased energy density, while providing all of the performance features provided by the current ceramic-coated plastic separators used in vehicle batteries: improved safety, longer cycle life, and stability to operate at voltages up to 5.0 V in order to obtain even more energy density. The thin all-ceramic separator provides a cost savings of at least 50% for the separator component and by itself meets the overall goal of this project to reduce the cell inactive component cost by at least 20%. The all-ceramic separator also enables further cost savings by its excellent heat stability

ElectroCat: DOE's approach to PGM-free catalyst and electrode R&D

Energy Technology Data Exchange (ETDEWEB)

Thompson, Simon T.; Wilson, Adria R.; Zelenay, Piotr; Myers, Deborah J.; More, Karren L.; Neyerlin, K. C.; Papageorgopoulos, Dimitrios

2018-06-01

The successful development of high-performance, durable platinum group metal-free (PGM-free) electrocatalysts and electrodes for polymer electrolyte membrane fuel cells (PEMFCs) will ultimately improve the cost-competiveness of fuel cells in a wide range of applications. This is considered to be a critical development especially for automotive fuel cell applications in order to bring the system cost of an automotive fuel cell system down to the $30/kW cost target set by the U.S. Department of Energy (DOE). The platinum group metal (PGM) electrocatalysts are a major contributor to the system cost. Addressing the technical challenges to PGM-free electrocatalyst and electrode development, therefore, represents one of DOE's most pressing research and development (R&D) priorities. ElectroCat was formed by the DOE as part of the Energy Materials Network (EMN) in early 2016, and shares with other EMN consortia the goal of decreasing the time to market for advanced materials related to clean energy technologies, in the context of increasing U.S. fuel cell electric vehicle (FCEV) manufacturing competitiveness. To accomplish this, the consortium performs core research and development and provides universities and companies streamlined access to the unique, world-class set of tools and expertise relevant to early-stage applied PGM-free catalyst R&D of the member national laboratories. Moreover, ElectroCat fosters a systematic methodology by which prospective catalysts and electrodes are prepared and analyzed rapidly and comprehensively using high-throughput, combinatorial methods. Catalyst discovery is augmented by theory as well as foundational electrocatalysis and materials knowledge at the participating national laboratories. Furthermore, ElectroCat has developed a data sharing framework, requisite of all EMN consortia, for disseminating its findings to the public via a searchable database, to further expedite incorporation of PGM-free electrocatalysts into next

Carbon Nanotubes Counter Electrode for Dye-Sensitized Solar Cells Application

Directory of Open Access Journals (Sweden)

Drygała A.

2016-06-01

Full Text Available The influence of the carbon nanotubes counter electrode deposited on the FTO glass substrates on the structure and optoelectrical properties of dye-sensitized solar cells counter electrode (CE was analysed. Carbon materials have been applied in DSSC s in order to produce low-cost solar cells with reasonable efficiency. Platinum is a preferred material for the counter electrode because of its high conductivity and catalytic activity. However, the costs of manufacturing of the platinum counter electrode limit its use to large-scale applications in solar cells. This paper presents the results of examining the structure and properties of the studied layers, defining optical properties of conductive layers and electrical properties of dye-sensitized solar cells manufactured with the use of carbon nanotubes.

Development of high temperature reference electrodes for potentiometric analyses in supercritical water environments

International Nuclear Information System (INIS)

Tung Yuming; Yeh Tsungkuang; Wang Meiya

2014-01-01

A specifically designed reference electrode was developed for analyzing the electrochemical behaviors of alloy materials in supercritical water (SCW) environments and identifying the associated electrochemical parameters. In this study, Ag/AgCl reference electrodes and Zr/ZrO 2 reference electrodes suitable for high-temperature applications were manufactured and adopted to measure the electrochemical corrosion potentials (ECPs) of 304L stainless steel (SS) and nickel-based alloy 625 in SCW environments with various amounts of dissolved oxygen (DO). The Ag/AgCl reference electrode made in this laboratory was used as a calibration base for the laboratory-made Zr/ZrO 2 reference electrode at high temperatures up to 400degC. The two reference electrodes were then used for ECP measurements of 304L SS and alloy 625 specimens in 400degC SCW with various DO levels of 300 ppb, 1 ppm, 8.3 ppm, and 32 ppm and under deaerated conditions. The outcome indicated that concentration increases in DO in the designated SCW environment would yield increases in ECP of the two alloys and they exhibited different ECP responses to DO levels. In addition, the laboratory-made Zr/ZrO 2 reference electrode was able to continuously operate for several months and delivered consistent and steady ECP data of the specimens in SCW environments. (author)

A single camera photogrammetry system for multi-angle fast localization of EEG electrodes.

Science.gov (United States)

Qian, Shuo; Sheng, Yang

2011-11-01

Photogrammetry has become an effective method for the determination of electroencephalography (EEG) electrode positions in three dimensions (3D). Capturing multi-angle images of the electrodes on the head is a fundamental objective in the design of photogrammetry system for EEG localization. Methods in previous studies are all based on the use of either a rotating camera or multiple cameras, which are time-consuming or not cost-effective. This study aims to present a novel photogrammetry system that can realize simultaneous acquisition of multi-angle head images in a single camera position. Aligning two planar mirrors with the angle of 51.4°, seven views of the head with 25 electrodes are captured simultaneously by the digital camera placed in front of them. A complete set of algorithms for electrode recognition, matching, and 3D reconstruction is developed. It is found that the elapsed time of the whole localization procedure is about 3 min, and camera calibration computation takes about 1 min, after the measurement of calibration points. The positioning accuracy with the maximum error of 1.19 mm is acceptable. Experimental results demonstrate that the proposed system provides a fast and cost-effective method for the EEG positioning.

Organic electrode materials for rechargeable lithium batteries

Energy Technology Data Exchange (ETDEWEB)

Liang, Yanliang; Tao, Zhanliang; Chen, Jun [Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), Chemistry College, Nankai University, Tianjin (China)

2012-07-15

Organic compounds offer new possibilities for high energy/power density, cost-effective, environmentally friendly, and functional rechargeable lithium batteries. For a long time, they have not constituted an important class of electrode materials, partly because of the large success and rapid development of inorganic intercalation compounds. In recent years, however, exciting progress has been made, bringing organic electrodes to the attention of the energy storage community. Herein thirty years' research efforts in the field of organic compounds for rechargeable lithium batteries are summarized. The working principles, development history, and design strategies of these materials, including organosulfur compounds, organic free radical compounds, organic carbonyl compounds, conducting polymers, non-conjugated redox polymers, and layered organic compounds are presented. The cell performances of these materials are compared, providing a comprehensive overview of the area, and straightforwardly revealing the advantages/disadvantages of each class of materials. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

A multi-pad electrode based functional electrical stimulation system for restoration of grasp

Directory of Open Access Journals (Sweden)

Malešević Nebojša M

2012-09-01

Full Text Available Abstract Background Functional electrical stimulation (FES applied via transcutaneous electrodes is a common rehabilitation technique for assisting grasp in patients with central nervous system lesions. To improve the stimulation effectiveness of conventional FES, we introduce multi-pad electrodes and a new stimulation paradigm. Methods The new FES system comprises an electrode composed of small pads that can be activated individually. This electrode allows the targeting of motoneurons that activate synergistic muscles and produce a functional movement. The new stimulation paradigm allows asynchronous activation of motoneurons and provides controlled spatial distribution of the electrical charge that is delivered to the motoneurons. We developed an automated technique for the determination of the preferred electrode based on a cost function that considers the required movement of the fingers and the stabilization of the wrist joint. The data used within the cost function come from a sensorized garment that is easy to implement and does not require calibration. The design of the system also includes the possibility for fine-tuning and adaptation with a manually controllable interface. Results The device was tested on three stroke patients. The results show that the multi-pad electrodes provide the desired level of selectivity and can be used for generating a functional grasp. The results also show that the procedure, when performed on a specific user, results in the preferred electrode configuration characteristics for that patient. The findings from this study are of importance for the application of transcutaneous stimulation in the clinical and home environments.

Development of a Novel Solid-State Sensor Electrode Based on Titanium Thin Film as an Indicator Electrode in Potentiometric and Conductometric Acid-Base Titration in Aqueous Solution

OpenAIRE

Abu Ghalwa, Nasser

2012-01-01

A modified Ti/(SnO2 + Sb2O3) electrode was prepared by thermal deposition on titanium substrate and its use as indicator electrode to potentiometric and conductometric acid-base titration in aqueous solution at 298 K was developed. The E-pH curve is linear with slope of 0.0512 V/dec at 298 K. The standard potential of this electrode, E0, was determined with respect to the SCE as reference electrode. The recovery percentages for potentiometric and conductometric acid-base titration for acetic ...

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.

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.

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.

Graphene-based transparent electrodes for hybrid solar cells

Directory of Open Access Journals (Sweden)

Pengfei eLi

2014-11-01

Full Text Available The graphene-based transparent and conductive films were demonstrated to be cost-effective electrodes working in organic-inorganic hybrid Schottky solar cells. Large area graphene films were produced by chemical vapor deposition (CVD on copper foils and transferred onto glass as transparent electrodes. The hybrid solar cell devices consist of solution processed poly (3, 4-ethlenedioxythiophene: poly (styrenesulfonate (PEDOT: PSS which is sandwiched between silicon wafer and graphene electrode. The solar cells based on graphene electrodes, especially those doped with HNO3, has comparable performance to the reference devices using commercial indium tin oxide (ITO. Our work suggests that graphene-based transparent electrode is a promising candidate to replace ITO.

Electrochemical Deposition of CdTe Semiconductor Thin Films for Solar Cell Application Using Two-Electrode and Three-Electrode Configurations: A Comparative Study

Directory of Open Access Journals (Sweden)

O. K. Echendu

2016-01-01

Full Text Available Thin films of CdTe semiconductor were electrochemically deposited using two-electrode and three-electrode configurations in potentiostatic mode for comparison. Cadmium sulphate and tellurium dioxide were used as cadmium and tellurium sources, respectively. The layers obtained using both configurations exhibit similar structural, optical, and electrical properties with no specific dependence on any particular electrode configuration used. These results indicate that electrochemical deposition (electrodeposition of CdTe and semiconductors in general can equally be carried out using two-electrode system as well as the conventional three-electrode system without compromising the essential qualities of the materials produced. The results also highlight the advantages of the two-electrode configuration in process simplification, cost reduction, and removal of a possible impurity source in the growth system, especially as the reference electrode ages.

Self-Aligned Metal Electrodes in Fully Roll-to-Roll Processed Organic Transistors

Directory of Open Access Journals (Sweden)

Marja Vilkman

2016-01-01

Full Text Available We demonstrate the production of organic bottom gate transistors with self-aligned electrodes, using only continuous roll-to-roll (R2R techniques. The self-alignment allows accurate <5 µm layer-to-layer registration, which is usually a challenge in high-speed R2R environments as the standard registration methods are limited to the millimeter range—or, at best, to tens of µm if online cameras and automatic web control are utilized. The improved registration enables minimizing the overlap between the source/drain electrodes and the gate electrode, which is essential for minimizing the parasitic capacitance. The complete process is a combination of several techniques, including evaporation, reverse gravure, flexography, lift-off, UV exposure and development methods—all transferred to a continuous R2R pilot line. Altogether, approximately 80 meters of devices consisting of thousands of transistors were manufactured in a roll-to-roll fashion. Finally, a cost analysis is presented in order to ascertain the main costs and to predict whether the process would be feasible for the industrial production of organic transistors.

Development of DBD plasma actuators: The double encapsulated electrode

Science.gov (United States)

Erfani, Rasool; Zare-Behtash, Hossein; Hale, Craig; Kontis, Konstantinos

2015-04-01

Plasma actuators are electrical devices that generate a wall bounded jet without the use of any moving parts. For aerodynamic applications they can be used as flow control devices to delay separation and augment lift on a wing. The standard plasma actuator consists of a single encapsulated (ground) electrode. The aim of this project is to investigate the effect of varying the number and distribution of encapsulated electrodes in the dielectric layer. Utilising a transformer cascade, a variety of input voltages are studied for their effect. In the quiescent environment of a Faraday cage the velocity flow field is recorded using particle image velocimetry. Through understanding of the mechanisms involved in producing the wall jet and the importance of the encapsulated electrode a novel actuator design is proposed. The actuator design distributes the encapsulated electrode throughout the dielectric layer. The experiments have shown that actuators with a shallow initial encapsulated electrode induce velocities greater than the baseline case at the same voltage. Actuators with a deep initial encapsulated electrode are able to induce the highest velocities as they can operate at higher voltages without breakdown of the dielectric.

Recent Development of Advanced Electrode Materials by Atomic Layer Deposition for Electrochemical Energy Storage.

Science.gov (United States)

Guan, Cao; Wang, John

2016-10-01

Electrode materials play a decisive role in almost all electrochemical energy storage devices, determining their overall performance. Proper selection, design and fabrication of electrode materials have thus been regarded as one of the most critical steps in achieving high electrochemical energy storage performance. As an advanced nanotechnology for thin films and surfaces with conformal interfacial features and well controllable deposition thickness, atomic layer deposition (ALD) has been successfully developed for deposition and surface modification of electrode materials, where there are considerable issues of interfacial and surface chemistry at atomic and nanometer scale. In addition, ALD has shown great potential in construction of novel nanostructured active materials that otherwise can be hardly obtained by other processing techniques, such as those solution-based processing and chemical vapor deposition (CVD) techniques. This review focuses on the recent development of ALD for the design and delivery of advanced electrode materials in electrochemical energy storage devices, where typical examples will be highlighted and analyzed, and the merits and challenges of ALD for applications in energy storage will also be discussed.

Design and development of electrical impedance tomography system with 32 electrodes and microcontroller

Science.gov (United States)

Ansory, Achmad; Prajitno, Prawito; Wijaya, Sastra Kusuma

2018-02-01

Electrical Impedance Tomography (EIT) is an imaging method that is able to estimate electrical impedance distribution inside an object. This EIT system is developed by using 32 electrodes and microcontroller based module. From a pair of electrodes, sinusoidal current of 3 mA is injected and the voltage differences between other pairs of electrodes are measured. Voltage measurement data are then sent to MATLAB and EIDORS software; the data are used to reconstruct two dimensions image. The system can detect and determine the position of a phantom in the tank. The object's position is accurately reconstructed and determined with the average shifting of 0.69 cm but object's area cannot be accurately reconstructed. The object's image is more accurately reconstructed when the object is located near to electrodes, has a larger size, and when the current injected to the system has a frequency of 100 kHz or 200kHz.

The development of a micropatterned electrode for studies of zinc electrodeposition

Energy Technology Data Exchange (ETDEWEB)

Sutija, Dave P. [Univ. of California, Berkeley, CA (United States); Muller, Rolf H. [Univ. of California, Berkeley, CA (United States); Tobias, Charles W. [Univ. of California, Berkeley, CA (United States)

1986-12-01

A micropatterned electrode was prepared for the study of electrocrystallization. Using microphotolithography, in conjunction with evaporation and pulse electrodeposition of thin films, a set of artificially roughened electrodes with hemispherical surface features five microns in diameter was developed. Voltammetric studies were conducted to determine the best electrode material. Gold, platinum, and various carbon surfaces were evaluated for zinc nucleation density and hydrogen overpotential. Surface homogeneity was examined by both light and scanning electron microscopy. Gold was determined to possess the best combination of material properties: chemical inertness, low melting point, and a high work function allowing underpotential deposition of zinc which reduces the rate of hydrogen evolution. Stripping coulometry was employed to determine zinc limiting currents, and evaluate effective diffusion coefficients in concentrated zinc chloride solutions. Although the method worked well for dilute zinc chloride and copper sulfate solutions, it failed at higher current densities; the emergence of surface roughness obscured actual limiting current plateaus.

Development of high-flexible triboelectric generators using plastic metal as electrodes

Science.gov (United States)

Yang, Sen-Yeu; Shih, Jian-Fu; Chang, Chih-Chieh; Yang, Chii-Rong

2017-02-01

A triboelectric generator is a device that harvests energy through the conversion of mechanical energy into electrical energy. In this work, two polymer materials (PDMS and PET) were selected as triboelectric layers in conjunction with plastic metal (PM) films as conductive layers to produce an electrode with high flexibility. The PDMS film was fabricated with a microstructural array to enhance friction. The proposed PM material was prepared by mixing gallium-indium liquid metal and a glaze powder with excellent coating ability, extensibility, and conductivity. Results demonstrate the superior characteristics of the PM flexible electrodes, including large bending angle (≥180°), small curvature radius (≤1 mm), and stable conductivity. This PM-based triboelectric generator can achieve average output voltage of 80 V and current of 37.2 μA. The proposed flexible electrode with a PM conductive layer could be expected to make a notable contribution to the development of wearable devices.

New Sunshine Program for fiscal 2000. Development of photovoltaic system commercialization technology - Development of thin-film solar cell manufacturing technology - Development of low-cost/large area module manufacturing technology (Development of novel amorphous solar cell module manufacturing technology); 2000 nendo New sunshine keikaku seika hokokusho. Taiyoko hatsuden system jitsuyoka gijutsu kaihatsu, Hakumaku taiyodenchi no seizo gijutsu kaihatsu, Tei cost dai menseki mojuru seizo gijutsu kaihatsu (Shingata amorufasu taiyo denchi mojuru no seizo gijutsu kaihatsu)

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-03-01

Research and development was conducted for the development of amorphous solar cell modules for power generation, high in performance and low in production cost. In the effort to improve cell efficiency, experiments were conducted for enhancing bottom a-SiGe cell efficiency for the embodiment of an enhanced-efficiency multi-junction cell, for improving crystallinity in microcrystalline silicon through the application of VHF (very high frequency) plasma CVD (chemical vapor deposition), for texturizing metal electrodes on a film substrate, and so forth. In the effort to increase the film fabrication rate, a VHF plasma CVD device was used for studying the effect of the discharge frequency on film deposition and quality, Vpp between the electrodes, and so forth. Studies about the high-throughput production technology centered on the film substrate solar cell process technology and the designing of an optimum geometrical pattern for SCAF (series-connection through apertures formed on film) cells. Production cost was estimated for the SCAF structure film substrate solar cell manufacturing process, and a production cost of 147.1 yen/W (in case of 100 MW/year production) was obtained as achievable under the currently available conditions. (NEDO)

Selective and lithography-independent fabrication of 20 nm nano-gap electrodes and nano-channels for nanoelectrofluidics applications

International Nuclear Information System (INIS)

Zhang, J Y; Wang, X F; Wang, X D; Fan, Z C; Li, Y; Ji, An; Yang, F H

2010-01-01

A new method has been developed to selectively fabricate nano-gap electrodes and nano-channels by conventional lithography. Based on a sacrificial spacer process, we have successfully obtained sub-100-nm nano-gap electrodes and nano-channels and further reduced the dimensions to 20 nm by shrinking the sacrificial spacer size. Our method shows good selectivity between nano-gap electrodes and nano-channels due to different sacrificial spacer etch conditions. There is no length limit for the nano-gap electrode and the nano-channel. The method reported in this paper also allows for wafer scale fabrication, high throughput, low cost, and good compatibility with modern semiconductor technology.

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.

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.

Low Impedance Carbon Adhesive Electrodes with Long Shelf Life.

Science.gov (United States)

Posada-Quintero, Hugo F; Reyes, Bersaín A; Burnham, Ken; Pennace, John; Chon, Ki H

2015-10-01

A novel electrocardiogram (ECG) electrode film is developed by mixing carbon black powder and a quaternary salt with a visco-elastic polymeric adhesive. Unlike traditional wet gel-based electrodes, carbon/salt/adhesive (CSA) electrodes should theoretically have an infinite shelf life as they do not dehydrate even after a prolonged period of storage. The CSA electrodes are electrically activated for use through the process of electrophoresis. Specifically, the activation procedure involves sending a high voltage and current through the electrode, which results in significant reduction of impedance so that high fidelity ECG signals can be obtained. Using the activation procedure, the ideal concentration of carbon black powder in the mixture with the adhesive was examined. It was determined that the optimum concentration of carbon black which minimized post-activation impedance was 10%. Once the optimal carbon black powder concentration was determined, extensive signal analysis was performed to compare the performance of the CSA electrodes to the standard silver-silver chloride (Ag/AgCl) electrodes. As a part of data analysis, electrode-skin contact impedance of the CSA was measured and compared to the standard Ag/AgCl electrodes; we found consistently lower impedance for CSA electrodes. For quantitative data analysis, we simultaneously collected ECG data with CSA and Ag/AgCl electrodes from 17 healthy subjects. Heart rate variability (HRV) indices and ECG morphological waveforms were calculated to compare CSA and Ag/AgCl electrodes. Non-significant differences for most of the HRV indices between CSA and Ag/AgCl electrodes were found. Of the morphological waveform metrics consisting of R-wave peak amplitude, ST-segment elevation and QT interval, only the first index was found to be significantly different between the two media. The response of CSA electrodes to motion artifacts was also tested, and we found in general no difference in the quality of the ECG signal

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.

Comparison of unusual carbon-based working electrodes for electrochemiluminescence sensors.

Science.gov (United States)

Noman, Muhammad; Sanginario, Alessandro; Jagadale, Pravin; Demarchi, Danilo; Tagliaferro, Alberto

2017-06-01

In this work, unconventional carbon-based materials were investigated for use in electrochemiluminescence (ECL) working electrodes. Precursors such as bamboo, pistachio shells, kevlar ® fibers and camphor were differently treated and used as working electrodes in ECL experiments. After a proper process they were assembled as electrodes and tested in an electrochemical cell. Comparison among them and with a commercial glassy carbon electrode (GCE) shows a very good response for all of them thus demonstrating their potential use as disposable low-cost electrodes for early detection electrochemical analysis. Copyright © 2017 Elsevier B.V. All rights reserved.

Graphene oxide - Polyvinyl alcohol nanocomposite based electrode material for supercapacitors

Science.gov (United States)

Pawar, Pranav Bhagwan; Shukla, Shobha; Saxena, Sumit

2016-07-01

Supercapacitors are high capacitive energy storage devices and find applications where rapid bursts of power are required. Thus materials offering high specific capacitance are of fundamental interest in development of these electrochemical devices. Graphene oxide based nanocomposites are mechanically robust and have interesting electronic properties. These form potential electrode materials efficient for charge storage in supercapacitors. In this perspective, we investigate low cost graphene oxide based nanocomposites as electrode material for supercapacitor. Nanocomposites of graphene oxide and polyvinyl alcohol were synthesized in solution phase by integrating graphene oxide as filler in polyvinyl alcohol matrix. Structural and optical characterizations suggest the formation of graphene oxide and polyvinyl alcohol nanocomposites. These nanocomposites were found to have high specific capacitance, were cyclable, ecofriendly and economical. Our studies suggest that nanocomposites prepared by adding 0.5% wt/wt of graphene oxide in polyvinyl alcohol can be used an efficient electrode material for supercapacitors.

Metal-free supercapacitor with aqueous electrolyte and low-cost carbon materials

Science.gov (United States)

Blomquist, Nicklas; Wells, Thomas; Andres, Britta; Bäckström, Joakim; Forsberg, Sven; Olin, Håkan

2017-01-01

Electric double-layer capacitors (EDLCs) or supercapacitors (SCs) are fast energy storage devices with high pulse efficiency and superior cyclability, which makes them useful in various applications including electronics, vehicles and grids. Aqueous SCs are considered to be more environmentally friendly than those based on organic electrolytes. Because of the corrosive nature of the aqueous environment, however, expensive electrochemically stable materials are needed for the current collectors and electrodes in aqueous SCs. This results in high costs for a given energy-storage capacity. To address this, we developed a novel low-cost aqueous SC using graphite foil as the current collector and a mix of graphene, nanographite, simple water-purification carbons and nanocellulose as electrodes. The electrodes were coated directly onto the graphite foil by using casting frames and the SCs were assembled in a pouch cell design. With this approach, we achieved a material cost reduction of greater than 90% while maintaining approximately one-half of the specific capacitance of a commercial unit, thus demonstrating that the proposed SC can be an environmentally friendly, low-cost alternative to conventional SCs.

Recent Progress in Organic Electrodes for Li and Na Rechargeable Batteries.

Science.gov (United States)

Lee, Sechan; Kwon, Giyun; Ku, Kyojin; Yoon, Kyungho; Jung, Sung-Kyun; Lim, Hee-Dae; Kang, Kisuk

2018-03-27

Organic rechargeable batteries, which use organics as electrodes, are excellent candidates for next-generation energy storage systems because they offer design flexibility due to the rich chemistry of organics while being eco-friendly and potentially cost efficient. However, their widespread usage is limited by intrinsic problems such as poor electronic conductivity, easy dissolution into liquid electrolytes, and low volumetric energy density. New types of organic electrode materials with various redox centers or molecular structures have been developed over the past few decades. Moreover, research aimed at enhancing electrochemical properties via chemical tuning has been at the forefront of organic rechargeable batteries research in recent years, leading to significant progress in their performance. Here, an overview of the current developments of organic rechargeable batteries is presented, with a brief history of research in this field. Various strategies for improving organic electrode materials are discussed with respect to tuning intrinsic properties of organics using molecular modification and optimizing their properties at the electrode level. A comprehensive understanding of the progress in organic electrode materials is provided along with the fundamental science governing their performance in rechargeable batteries thus a guide is presented to the optimal design strategies to improve the electrochemical performance for next-generation battery systems. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A thermally regenerative ammonia battery with carbon-silver electrodes for converting low-grade waste heat to electricity

Science.gov (United States)

Rahimi, Mohammad; Kim, Taeyoung; Gorski, Christopher A.; Logan, Bruce E.

2018-01-01

Thermally regenerative ammonia batteries (TRABs) have shown great promise as a method to convert low-grade waste heat into electrical power, with power densities an order of magnitude higher than other approaches. However, previous TRABs based on copper electrodes suffered from unbalanced anode dissolution and cathode deposition rates during discharging cycles, limiting practical applications. To produce a TRAB with stable and reversible electrode reactions over many cycles, inert carbon electrodes were used with silver salts. In continuous flow tests, power production was stable over 100 discharging cycles, demonstrating excellent reversibility. Power densities were 23 W m-2-electrode area in batch tests, which was 64% higher than that produced in parallel tests using copper electrodes, and 30 W m-2 (net energy density of 490 Wh m-3-anolyte) in continuous flow tests. While this battery requires the use a precious metal, an initial economic analysis of the system showed that the cost of the materials relative to energy production was 220 per MWh, which is competitive with energy production from other non-fossil fuel sources. A substantial reduction in costs could be obtained by developing less expensive anion exchange membranes.

Phosphate Framework Electrode Materials for Sodium Ion Batteries.

Science.gov (United States)

Fang, Yongjin; Zhang, Jiexin; Xiao, Lifen; Ai, Xinping; Cao, Yuliang; Yang, Hanxi

2017-05-01

Sodium ion batteries (SIBs) have been considered as a promising alternative for the next generation of electric storage systems due to their similar electrochemistry to Li-ion batteries and the low cost of sodium resources. Exploring appropriate electrode materials with decent electrochemical performance is the key issue for development of sodium ion batteries. Due to the high structural stability, facile reaction mechanism and rich structural diversity, phosphate framework materials have attracted increasing attention as promising electrode materials for sodium ion batteries. Herein, we review the latest advances and progresses in the exploration of phosphate framework materials especially related to single-phosphates, pyrophosphates and mixed-phosphates. We provide the detailed and comprehensive understanding of structure-composition-performance relationship of materials and try to show the advantages and disadvantages of the materials for use in SIBs. In addition, some new perspectives about phosphate framework materials for SIBs are also discussed. Phosphate framework materials will be a competitive and attractive choice for use as electrodes in the next-generation of energy storage devices.

Improved Internal Reference Oxygen Sensors with Composite Ceramic Electrodes

DEFF Research Database (Denmark)

Hu, Qiang; Jacobsen, Torben; Hansen, Karin Vels

2012-01-01

Potentiometric oxygen sensors with an internal reference electrode, which uses the equilibrium pO2 of the binary mixture of Ni/NiO as the reference, are demonstrated. The cells employ Pt or composite ceramics as the sensing electrode. The cells are fabricated by a flexible and potentially low cost...... and performance are highly reproducible. The composite ceramics, based on strontium doped manganite and yttria doped zirconia, are proven superior over Pt to serve as the electrode material....

Hot electron-induced electrochemiluminescence at polyetherimide-carbon black-based electrodes

International Nuclear Information System (INIS)

Salminen, Kalle; Grönroos, Päivi; Johansson, Leena-Sisko; Campbell, Joseph; Kulmala, Sakari

2017-01-01

Highlights: • Generation of hydrated electrons at carbon paste electrodes. • Hydrated electrons are able to produce intense chemiluminescence. • Relationship between carbon black content in electrode and HECL studied. • Performance of composite electrodes is similar to aluminum electrodes. • The present electrodes are good alternative for disposable assay cartridges. - Abstract: Various luminophores produce strong electrogenerated chemiluminescence during cathodic pulse polarization of the present insulating film-covered carbon paste electrodes in fully aqueous solutions. First electrodes made of a commercial conductive carbon paste were successfully utilized as working electrodes and their surface was characterized by ESCA. Then custom in-laboratory made improved composite electrodes were manufactured from the same insulating polymer and conducting carbon black particles. The relationship between the amount of carbon present on the composite electrode, in the bulk and on the surface, and the intensity of electrogenerated chemiluminescence was studied further. The overall performance of these composite electrodes makes them viable low-cost replacements for metal/insulator type electrodes such as oxide-coated silicon electrodes.

Auditory brainstem activity and development evoked by apical versus basal cochlear implant electrode stimulation in children.

Science.gov (United States)

Gordon, K A; Papsin, B C; Harrison, R V

2007-08-01

The role of apical versus basal cochlear implant electrode stimulation on central auditory development was examined. We hypothesized that, in children with early onset deafness, auditory development evoked by basal electrode stimulation would differ from that evoked more apically. Responses of the auditory nerve and brainstem, evoked by an apical and a basal implant electrode, were measured over the first year of cochlear implant use in 50 children with early onset severe to profound deafness who used hearing aids prior to implantation. Responses at initial stimulation were of larger amplitude and shorter latency when evoked by the apical electrode. No significant effects of residual hearing or age were found on initial response amplitudes or latencies. With implant use, responses evoked by both electrodes showed decreases in wave and interwave latencies reflecting decreased neural conduction time through the brainstem. Apical versus basal differences persisted with implant experience with one exception; eIII-eV interlatency differences decreased with implant use. Acute stimulation shows prolongation of basally versus apically evoked auditory nerve and brainstem responses in children with severe to profound deafness. Interwave latencies reflecting neural conduction along the caudal and rostral portions of the brainstem decreased over the first year of implant use. Differences in neural conduction times evoked by apical versus basal electrode stimulation persisted in the caudal but not rostral brainstem. Activity-dependent changes of the auditory brainstem occur in response to both apical and basal cochlear implant electrode stimulation.

Metal nanogrids, nanowires, and nanofibers for transparent electrodes

KAUST Repository

Hu, Liangbing; Wu, Hui; Cui, Yi

2011-01-01

Metals possess the highest conductivity among all room-temperature materials; however, ultrathin metal films demonstrate decent optical transparency but poor sheet conductance due to electron scattering from the surface and grain boundaries. This article discusses engineered metal nanostructures in the form of nanogrids, nanowires, or continuous nanofibers as efficient transparent and conductive electrodes. Metal nanogrids are discussed, as they represent an excellent platform for understanding the fundamental science. Progress toward low-cost, nano-ink-based printed silver nanowire electrodes, including silver nanowire synthesis, film fabrication, wire-wire junction resistance, optoelectronic properties, and stability, are also discussed. Another important factor for low-cost application is to use earth-abundant materials. Copper-based nanowires and nanofibers are discussed in this context. Examples of device integrations of these materials are also given. Such metal nanostructure-based transparent electrodes are particularly attractive for solar cell applications. © 2011 Materials Research Society.

Metal nanogrids, nanowires, and nanofibers for transparent electrodes

KAUST Repository

Hu, Liangbing

2011-10-01

Metals possess the highest conductivity among all room-temperature materials; however, ultrathin metal films demonstrate decent optical transparency but poor sheet conductance due to electron scattering from the surface and grain boundaries. This article discusses engineered metal nanostructures in the form of nanogrids, nanowires, or continuous nanofibers as efficient transparent and conductive electrodes. Metal nanogrids are discussed, as they represent an excellent platform for understanding the fundamental science. Progress toward low-cost, nano-ink-based printed silver nanowire electrodes, including silver nanowire synthesis, film fabrication, wire-wire junction resistance, optoelectronic properties, and stability, are also discussed. Another important factor for low-cost application is to use earth-abundant materials. Copper-based nanowires and nanofibers are discussed in this context. Examples of device integrations of these materials are also given. Such metal nanostructure-based transparent electrodes are particularly attractive for solar cell applications. © 2011 Materials Research Society.

Numerical modelling of needle-grid electrodes for negative surface corona charging system

International Nuclear Information System (INIS)

Zhuang, Y; Chen, G; Rotaru, M

2011-01-01

Surface potential decay measurement is a simple and low cost tool to examine electrical properties of insulation materials. During the corona charging stage, a needle-grid electrodes system is often used to achieve uniform charge distribution on the surface of the sample. In this paper, a model using COMSOL Multiphysics has been developed to simulate the gas discharge. A well-known hydrodynamic drift-diffusion model was used. The model consists of a set of continuity equations accounting for the movement, generation and loss of charge carriers (electrons, positive and negative ions) coupled with Poisson's equation to take into account the effect of space and surface charges on the electric field. Four models with the grid electrode in different positions and several mesh sizes are compared with a model that only has the needle electrode. The results for impulse current and surface charge density on the sample clearly show the effect of the extra grid electrode with various positions.

Development of a Novel Solid-State Sensor Electrode Based on Titanium Thin Film as an Indicator Electrode in Potentiometric and Conductometric Acid-Base Titration in Aqueous Solution

Directory of Open Access Journals (Sweden)

Nasser Abu Ghalwa

2012-01-01

Full Text Available A modified Ti/(SnO2 + Sb2O3 electrode was prepared by thermal deposition on titanium substrate and its use as indicator electrode to potentiometric and conductometric acid-base titration in aqueous solution at 298 K was developed. The E-pH curve is linear with slope of 0.0512 V/dec at 298 K. The standard potential of this electrode, E0, was determined with respect to the SCE as reference electrode. The recovery percentages for potentiometric and conductometric acid-base titration for acetic acid against NaOH were calculated. The cell constant, specific conductance, and the molar conductance with dilution for some common electrolytes were measured.

High-performance flexible electrode based on electrodeposition of polypyrrole/MnO2 on carbon cloth for supercapacitors

Science.gov (United States)

Fan, Xingye; Wang, Xiaolei; Li, Ge; Yu, Aiping; Chen, Zhongwei

2016-09-01

A highly flexible electrodes based on electrodeposited MnO2 and polypyrrole composite on carbon cloth is designed and developed by a facile in-situ electrodeposition technique. Such flexible composite electrodes with multiply layered structure possess a high specific capacitance of 325 F g-1 at a current density of 0.2 A g-1, and an excellent rate capability with a capacitance retention of 70% at a high current density of 5.0 A g-1. The superior electrochemical performance is mainly due to the unique electrode with improved ion- and electron-transportation pathways as well as the efficient utilization of active materials and electrode robustness. The excellent electrochemical performance and the low cost property endow this flexible nanocomposite electrode with great promise in applications of flexible supercapacitors.

The cost of electrocoagulation

Energy Technology Data Exchange (ETDEWEB)

Donini, J.C.; Kan, J.; Szynkarczuk, J.; Hassan, T.A.; Kar, K.L.

1993-01-01

Recent research has shown that electrocoagulation is suitable for separating solids from waste water. The purpose of this study is to determine whether the method is feasible economically. The cost incurred, namely energy costs and aluminum electrode consumed, during electrocoagulation experiments with kaolinite and bentonite are examined. Emphasis is placed on sodium chloride concentration, flow rate with and without recirculation, formation of passivation layers, how sodium chloride affects aluminum efficiency, and electrode efficiency. Further study is required. 8 refs., 25 figs., 9 tabs.

Disclosing finding and development costs

International Nuclear Information System (INIS)

Janisch, M.L.

1998-01-01

The importance of finding and development costs in the petroleum industry and the issue of how they can be either manipulated or misunderstood was discussed. Finding and development costs are usually expressed in terms of $/BOE (barrel of oil equivalents) and reflect the total capital expenditures divided by the total reserves replaced and added. Various examples of the importance of finding and development costs in making investment decisions were used to illustrate the effects of potential bias by the resource company, and the need for care and understanding of what the numbers issued by the company actually mean. In general, low and consistent finding and development costs, combined with good netbacks, are the key to value added for shareholders. tabs

The rise of organic electrode materials for energy storage.

Science.gov (United States)

Schon, Tyler B; McAllister, Bryony T; Li, Peng-Fei; Seferos, Dwight S

2016-11-07

Organic electrode materials are very attractive for electrochemical energy storage devices because they can be flexible, lightweight, low cost, benign to the environment, and used in a variety of device architectures. They are not mere alternatives to more traditional energy storage materials, rather, they have the potential to lead to disruptive technologies. Although organic electrode materials for energy storage have progressed in recent years, there are still significant challenges to overcome before reaching large-scale commercialization. This review provides an overview of energy storage systems as a whole, the metrics that are used to quantify the performance of electrodes, recent strategies that have been investigated to overcome the challenges associated with organic electrode materials, and the use of computational chemistry to design and study new materials and their properties. Design strategies are examined to overcome issues with capacity/capacitance, device voltage, rate capability, and cycling stability in order to guide future work in the area. The use of low cost materials is highlighted as a direction towards commercial realization.

Electrochemical studies on nanometal oxide-activated carbon composite electrodes for aqueous supercapacitors

Science.gov (United States)

Ho, Mui Yen; Khiew, Poi Sim; Isa, Dino; Chiu, Wee Siong

2014-11-01

In present study, the electrochemical performance of eco-friendly and cost-effective titanium oxide (TiO2)-based and zinc oxide-based nanocomposite electrodes were studied in neutral aqueous Na2SO3 electrolyte, respectively. The electrochemical properties of these composite electrodes were studied using cyclic voltammetry (CV), galvanostatic charge-discharge (CD) and electrochemical impedance spectroscopy (EIS). The experimental results reveal that these two nanocomposite electrodes achieve the highest specific capacitance at fairly low oxide loading onto activated carbon (AC) electrodes, respectively. Considerable enhancement of the electrochemical properties of TiO2/AC and ZnO/AC nanocomposite electrodes is achieved via synergistic effects contributed from the nanostructured metal oxides and the high surface area mesoporous AC. Cations and anions from metal oxides and aqueous electrolyte such as Ti4+, Zn2+, Na+ and SO32- can occupy some pores within the high-surface-area AC electrodes, forming the electric double layer at the electrode-electrolyte interface. Additionally, both TiO2 and ZnO nanoparticles can provide favourable surface adsorption sites for SO32- anions which subsequently facilitate the faradaic processes for pseudocapacitive effect. These two systems provide the low cost material electrodes and the low environmental impact electrolyte which offer the increased charge storage without compromising charge storage kinetics.

Electrochemical characterization of LiCoO2 as rechargeable electrode in aqueous LiNO3 electrolyte

KAUST Repository

Ruffo, Riccardo; La Mantia, Fabio; Wessells, Colin; Huggins, Robert A.; Cui, Yi

2011-01-01

The development of lithium ion aqueous batteries is getting renewed interest due to their safety and low cost. We have demonstrated that the layer-structure LiCoO2 phase, the most commonly used electrode material in organic systems, can

Development of a Flexible Non-Metal Electrode for Cell Stimulation and Recording

Directory of Open Access Journals (Sweden)

Cihun-Siyong Alex Gong

2016-09-01

Full Text Available This study presents a method of producing flexible electrodes for potentially simultaneously stimulating and measuring cellular signals in retinal cells. Currently, most multi-electrode applications rely primarily on etching, but the metals involved have a certain degree of brittleness, leaving them prone to cracking under prolonged pressure. This study proposes using silver chloride ink as a conductive metal, and polydimethysiloxane (PDMS as the substrate to provide electrodes with an increased degree of flexibility to allow them to bend. This structure is divided into the electrode layer made of PDMS and silver chloride ink, and a PDMS film coating layer. PDMS can be mixed in different proportions to modify the degree of rigidity. The proposed method involved three steps. The first segment entailed the manufacturing of the electrode, using silver chloride ink as the conductive material, and using computer software to define the electrode size and micro-engraving mechanisms to produce the electrode pattern. The resulting uniform PDMS pattern was then baked onto the model, and the flow channel was filled with the conductive material before air drying to produce the required electrode. In the second stage, we tested the electrode, using an impedance analyzer to measure electrode cyclic voltammetry and impedance. In the third phase, mechanical and biocompatibility tests were conducted to determine electrode properties. This study aims to produce a flexible, non-metallic sensing electrode which fits snugly for use in a range of measurement applications.

Digital grayscale printing for patterned transparent conducting Ag electrodes and their applications in flexible electronics

DEFF Research Database (Denmark)

Gupta, Ritu; Hösel, Markus; Jensen, Jacob

2014-01-01

Grayscale (halftone) laser printing is developed as a low-cost and solution processable fabrication method for ITO-free, semi-transparent and conducting Ag electrodes extendable over large area on a flexible substrate. The transmittance and sheet resistance is easily tunable by varying the graysc...

Electroretinography in dogs using a fiber electrode prototype

Directory of Open Access Journals (Sweden)

A.L. Pereira

2013-03-01

Full Text Available We compared two electroretinography (ERG electrodes in dogs using ERG standards of the International Society for Clinical Electrophysiology of Vision (ISCEV. Ten healthy Yorkshire terrier dogs (mean age, 2.80 ± 1.42 years; 6 females weighing 5.20 ± 1.56 kg were evaluated using an ERG system for veterinary use. Dark- and light-adapted ERG responses were recorded using an ERG-Jet electrode and a fiber electrode prototype. The examinations were performed during 2 visits, 3 weeks apart. Both electrodes (ERG-Jet or fiber prototype were used on each animal and the first eye to be recorded (OD × OS was selected randomly. Three weeks later the examination was repeated on the same animal switching the type of electrode to be used that day and the first eye to be examined. The magnitude and waveform quality obtained with the two electrode types were similar for all ERG responses. ERG amplitudes and implicit times obtained from dogs using the fiber electrode prototype were comparable to those obtained with the ERG-Jet electrode for rod, maximal rod-cone summed, cone, and 30-Hz flicker responses. The fiber electrode prototype is a low-cost device, available as an alternative instrument for clinical veterinary ERG recording for retinal function assessment.

Electroretinography in dogs using a fiber electrode prototype

Directory of Open Access Journals (Sweden)

A.L. Pereira

Full Text Available We compared two electroretinography (ERG electrodes in dogs using ERG standards of the International Society for Clinical Electrophysiology of Vision (ISCEV. Ten healthy Yorkshire terrier dogs (mean age, 2.80 ± 1.42 years; 6 females weighing 5.20 ± 1.56 kg were evaluated using an ERG system for veterinary use. Dark- and light-adapted ERG responses were recorded using an ERG-Jet electrode and a fiber electrode prototype. The examinations were performed during 2 visits, 3 weeks apart. Both electrodes (ERG-Jet or fiber prototype were used on each animal and the first eye to be recorded (OD × OS was selected randomly. Three weeks later the examination was repeated on the same animal switching the type of electrode to be used that day and the first eye to be examined. The magnitude and waveform quality obtained with the two electrode types were similar for all ERG responses. ERG amplitudes and implicit times obtained from dogs using the fiber electrode prototype were comparable to those obtained with the ERG-Jet electrode for rod, maximal rod-cone summed, cone, and 30-Hz flicker responses. The fiber electrode prototype is a low-cost device, available as an alternative instrument for clinical veterinary ERG recording for retinal function assessment.

Electroretinography in dogs using a fiber electrode prototype

International Nuclear Information System (INIS)

Pereira, A.L.; Montiani-Ferreira, F.; Santos, V.R.; Salomão, S.R.; Souza, C.; Berezovsky, A.

2013-01-01

We compared two electroretinography (ERG) electrodes in dogs using ERG standards of the International Society for Clinical Electrophysiology of Vision (ISCEV). Ten healthy Yorkshire terrier dogs (mean age, 2.80 ± 1.42 years; 6 females) weighing 5.20 ± 1.56 kg were evaluated using an ERG system for veterinary use. Dark- and light-adapted ERG responses were recorded using an ERG-Jet electrode and a fiber electrode prototype. The examinations were performed during 2 visits, 3 weeks apart. Both electrodes (ERG-Jet or fiber prototype) were used on each animal and the first eye to be recorded (OD × OS) was selected randomly. Three weeks later the examination was repeated on the same animal switching the type of electrode to be used that day and the first eye to be examined. The magnitude and waveform quality obtained with the two electrode types were similar for all ERG responses. ERG amplitudes and implicit times obtained from dogs using the fiber electrode prototype were comparable to those obtained with the ERG-Jet electrode for rod, maximal rod-cone summed, cone, and 30-Hz flicker responses. The fiber electrode prototype is a low-cost device, available as an alternative instrument for clinical veterinary ERG recording for retinal function assessment

Electrogenerated chemiluminescence of luminol using low-cost electrodes

International Nuclear Information System (INIS)

Salgado, Guillermo; Navarrete, Jose; Bustos, Carlos; Sanchez, Cristian; Ugarte, Ricardo

2006-01-01

The purpose of the study was to observe eletrogenerated chemiluminescence (ECL) of luminol using different materials as electrodes such as wires, nails, coins, razor blades, etc. Based on the experimental observations and the mechanisms proposed in the literature, students should be capable of analyzing their results in order to understand the phenomena studied. Students could then elaborate a mechanism of action consistent with the experimental results which could rationalize the formation of intermediates in the reaction and the dependence of ECL on solution pH in addition to other points of interest. (author)

The negative electrode development for a Ni-MH battery prototype

International Nuclear Information System (INIS)

Cuscueta, D.J.; Ghilarducci, A.A.; Salva, H.R.; Milocco, R.H.; Castro, E.B.

2009-01-01

The negative electrode development for a nickel-metal hydride battery (Ni-MH) prototype was performed with the following procedure: (1) the Lm 0.95 Ni 3.8 Co 0.3 Mn 0.3 Al 0.4 (Lm=lanthanum rich mischmetal) intermetallic alloy was elaborated by melting the pure elements in an induction furnace inside a boron nitride crucible under an inert atmosphere, (2) the obtained alloy was crushed and sieved between 44 and 74 μm and mixed with teflonized carbon; (3) the compound was assembled together with a current collector and pressed in a cylindrical matrix. The obtained electrode presented a disc shape, with 11 mm diameter and approximately 1 mm thickness. The crystalline structure of the hydrogen storage alloy was examined using X-ray diffractometry. The measured hcp lattice volume was 1.78% larger than the precursor LaNi 5 intermetallic alloy, increasing the available space for hydrogen movement. Energy dispersive spectroscopy (EDS) and scanning electronic microscopy (SEM) measurements were used before and after hydriding in order to verify the alloy sample homogeneity. The negative electrode was electrochemically tested by using a laboratory cell. It activates almost totally in its first cycle, which is an excellent characteristic from the commercial point of view. The maximum discharge capacity reached was 314.2 mA h/g in the 10th cycle.

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

Activated carbon fiber obtained from textile PAN fiber to electrodes for supercapacitor

International Nuclear Information System (INIS)

Silva, Elen Leal da; Marcuzzo, Jossano Saldanha; Baldan, Mauricio Ribeiro; Cuna, Andres; Rodrigues, Aline Castilho; Goncalves, Emerson Sarmento

2016-01-01

Full text: Supercapacitors are devices for electrical energy storage with application in distribution power generation, electric vehicles, electronic equipment, among others. Current challenges in the development of supercapacitors focuses on making an increasing on system density of energy. An increase of energy accumulated in the supercapacitor electrode can be achieved by developing materials with high specific electrical capacitance and low electrical resistance. Furthermore, it is expected that the electrode material present a simple procedure for obtaining, low cost and environmentally friendly. Carbon fibers are interesting materials for use as a supercapacitor electrode. Among them are carbon fibers from polyacrylonitrile (PAN). In this work were studied activated carbon fibers obtained from textile polyacrylonitrile (ACF-PAN) with deposition of Fe particles aiming to use as active material of supercapacitor electrodes. ACFPAN and ACF-PAN-Fe were characterized by textural analysis, x-ray diffraction (XRD), scanning electron microscopy equipped with energy dispersive x-ray (SEM-EDX), Raman spectroscopy and x-ray photoelectron spectroscopy (XPS). The behavior of the activated carbon fibers as a supercapacitor electrode was evaluated by galvanostatic charge and discharge curves, cyclic voltammetry and a electrochemical impedance using a symmetrical two-electrode Swagelok®-type cell and sulfuric acid as electrolyte. ACF-PAN had a high specific surface area, which makes it an interesting material for electrodes of supercapacitors. The electrical capacitance for the ACF-PAN is 96 F/g and ACF-PAN-Fe is 106 F/g both at a current density of 0.30 A/g. This increase in electrical capacitance can be related to the presence of iron oxides which are deposited on the activated carbon fiber. (author)

Department of Energy Environmental Management cost infrastructure development program: Cost analysis requirements

International Nuclear Information System (INIS)

Custer, W.R. Jr.; Messick, C.D.

1996-01-01

This report was prepared to support development of the Department of Energy Environmental Management cost infrastructure -- a new capability to independently estimate and analyze costs. Currently, the cost data are reported according to a structure that blends level of effort tasks with product and process oriented tasks. Also. the budgetary inputs are developed from prior year funding authorizations and from contractor-developed parametric estimates that have been adjusted to planned funding levels or appropriations. Consequently, it is difficult for headquarters and field-level activities to use actual cost data and technical requirements to independently assess the costs generated and identify trends, potential cost savings from process improvements, and cost reduction strategies

Development of highly transparent Pd-coated Ag nanowire electrode for display and catalysis applications

Energy Technology Data Exchange (ETDEWEB)

Canlier, Ali, E-mail: ali.canlier@agu.edu.tr [Department of Materials Science and Nanotechnology Engineering, Abdullah Gul University, P.O. Box 38080, Kayseri (Turkey); Ucak, Umit Volkan, E-mail: sirvolkan@gmail.com [Department of Materials Science and Nanotechnology Engineering, Abdullah Gul University, P.O. Box 38080, Kayseri (Turkey); Graduate School of Energy, Environment, Water, and Sustainability (EEWS), Korea Advanced Institute of Science and Technology (KAIST), P.O. Box 305-701, Daejeon (Korea, Republic of); Usta, Hakan, E-mail: husta38@gmail.com [Department of Materials Science and Nanotechnology Engineering, Abdullah Gul University, P.O. Box 38080, Kayseri (Turkey); Cho, Changsoon, E-mail: cscho@kaist.ac.kr [Graduate School of Energy, Environment, Water, and Sustainability (EEWS), Korea Advanced Institute of Science and Technology (KAIST), P.O. Box 305-701, Daejeon (Korea, Republic of); Lee, Jung-Yong, E-mail: jungyong.lee@kaist.ac.kr [Graduate School of Energy, Environment, Water, and Sustainability (EEWS), Korea Advanced Institute of Science and Technology (KAIST), P.O. Box 305-701, Daejeon (Korea, Republic of); Sen, Unal, E-mail: senunal@gmail.com [Department of Mechanical Engineering, Abdullah Gul University, P.O. Box 38080, Kayseri (Turkey); Citir, Murat, E-mail: muratcitir@gmail.com [Department of Chemical Engineering, Abdullah Gul University, P.O. Box 38080, Kayseri (Turkey)

2015-09-30

Highlights: • Highly uniform thin-layer coating of Pd onto Ag nanowire surface was accomplished. • A transparent electrode of Pd-coated Ag nanowire was uniformly deposited on flexible substrate. • 95% of optical transmittance and 175 Ω/sq sheet resistance were obtained. • Extremely low haze of 1.9% and high oxidation stability proved an efficient transparent electrode. • This electrode can be used as Pd-catalyst for synthesis reactions and fuel cell electrode applications. - Abstract: Ag nanowire transparent electrode has excellent transmittance (90%) and sheet resistance (20 Ω/sq), yet there are slight drawbacks such as optical haze and chemical instability against aerial oxidation. Chemical stability of Ag nanowires needs to be improved in order for it to be suitable for electrode applications. In our recent article, we demonstrated that coating Ag nanowires with a thin layer of Au through galvanic exchange reactions enhances the chemical stability of Ag nanowire films highly and also helps to obtain lower haze. In this study, coating of a thin Pd layer has been applied successfully onto the surface of Ag nanowires. A mild Pd complex oxidant [Pd(en){sub 2}](NO{sub 3}){sub 2} was prepared in order to oxidize Ag atoms partially on the surface via galvanic displacement. The mild galvanic exchange allowed for a thin layer (1–2 nm) of Pd coating on the Ag nanowires with minimal truncation of the nanowire, where the average length and the diameter were 12.5 μm and 59 nm, respectively. The Pd-coated Ag nanowires were suspended in methanol and then electrostatically sprayed on flexible polycarbonate substrates. It has been revealed that average total transmittance remain around 95% within visible spectrum region (400–800 nm) whereas sheet resistance rises up to 175 Ω/sq. To the best of our knowledge, for the first time in the literature, Pd coating was employed on Ag nanowires in order to design transparent electrodes for high transparency and strong

Potassium Sodium Niobate-Based Lead-Free Piezoelectric Multilayer Ceramics Co-Fired with Nickel Electrodes

Directory of Open Access Journals (Sweden)

Shinichiro Kawada

2015-11-01

Full Text Available Although lead-free piezoelectric ceramics have been extensively studied, many problems must still be overcome before they are suitable for practical use. One of the main problems is fabricating a multilayer structure, and one solution attracting growing interest is the use of lead-free multilayer piezoelectric ceramics. The paper reviews work that has been done by the authors on lead-free alkali niobate-based multilayer piezoelectric ceramics co-fired with nickel inner electrodes. Nickel inner electrodes have many advantages, such as high electromigration resistance, high interfacial strength with ceramics, and greater cost effectiveness than silver palladium inner electrodes. However, widely used lead zirconate titanate-based ceramics cannot be co-fired with nickel inner electrodes, and silver palladium inner electrodes are usually used for lead zirconate titanate-based piezoelectric ceramics. A possible alternative is lead-free ceramics co-fired with nickel inner electrodes. We have thus been developing lead-free alkali niobate-based multilayer ceramics co-fired with nickel inner electrodes. The normalized electric-field-induced thickness strain (Smax/Emax of a representative alkali niobate-based multilayer ceramic structure with nickel inner electrodes was 360 pm/V, where Smax denotes the maximum strain and Emax denotes the maximum electric field. This value is about half that for the lead zirconate titanate-based ceramics that are widely used. However, a comparable value can be obtained by stacking more ceramic layers with smaller thicknesses. In the paper, the compositional design and process used to co-fire lead-free ceramics with nickel inner electrodes are introduced, and their piezoelectric properties and reliabilities are shown. Recent advances are introduced, and future development is discussed.

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.

Advanced Architectures and Relatives of Air Electrodes in Zn–Air Batteries

Science.gov (United States)

Pan, Jing; Xu, Yang Yang; Yang, Huan; Dong, Zehua; Liu, Hongfang

2018-01-01

Abstract Zn–air batteries are becoming the promising power sources for portable and wearable electronic devices and hybrid/electric vehicles because of their high specific energy density and the low cost for next‐generation green and sustainable energy technologies. An air electrode integrated with an oxygen electrocatalyst is the most important component and inevitably determines the performance and cost of a Zn–air battery. This article presents exciting advances and challenges related to air electrodes and their relatives. After a brief introduction of the Zn–air battery, the architectures and oxygen electrocatalysts of air electrodes and relevant electrolytes are highlighted in primary and rechargeable types with different configurations, respectively. Moreover, the individual components and major issues of flexible Zn–air batteries are also highlighted, along with the strategies to enhance the battery performance. Finally, a perspective for design, preparation, and assembly of air electrodes is proposed for the future innovations of Zn–air batteries with high performance. PMID:29721418

Nucleic Acids and Enzymes at Electrodes: Electrochemical Nanomedical Biosensors and Biofuel Cell Development

DEFF Research Database (Denmark)

Ferapontova, Elena

Starting from the development of the first electrochemical biosensor for glucose, as far as in 1962, the electrochemical biosensor research area underwent a dramatic evolution both in scientific and commercial directions. At present, electrochemical biosensors are widely used in medical practice,...... perspectives of the biosensor research and such biotechnological applications as enzyme electrodes for sustainable energy production (6) will be discussed.......Starting from the development of the first electrochemical biosensor for glucose, as far as in 1962, the electrochemical biosensor research area underwent a dramatic evolution both in scientific and commercial directions. At present, electrochemical biosensors are widely used in medical practice......, by offering extremely sensitive and accurate yet simple, rapid, and inexpensive biosensing platforms (1). In this talk, I will discuss the developed at iNANO reagentless enzymatic biosensors, in which the enzyme is directly electronically coupled to the electrode (1-3), and advanced genosensor platforms...

Impact of uniform electrode current distribution on ETF

Science.gov (United States)

Bents, D. J.

1982-01-01

The design impacts on the ETF electrode consolidation network associated with uniform channel electrode current distribution are examined and the alternate consolidation design which occur are presented compared to the baseline (non-uniform current) design with respect to performance, and hardware requirements. A rational basis is given for comparing the requirements for the different designs and the savings that result from uniform current distribution. Performance and cost impacts upon the combined cycle plant are discussed.

Development of innovative micro-pattern gaseous detectors with resistive electrodes and first results of their applications

CERN Document Server

Di Mauro, A; Martinengo, P; Nappi, E; Oliveira, R; Peskov, Vladimir; Periale, L; Picchi, P; Pietropaolo, F; Rodionov, I; Santiard, Jean-Claude

2007-01-01

The paper summarizes our latest progress in the development of newly introduced micro pattern gaseous detectors with resistive electrodes. These resistive electrodes protect the detector and the front-end electronics in case of occasional discharges and thus make the detectors very robust and reliable in operation. As an example, we describe in greater detail a new recently developed GEM-like detector, fully spark-protected with electrodes made of resistive kapton. We discovered that all resistive layers used in these studies (including kapton), that are coated with photosensitive layers, such as CsI, can be used as efficient photo cathodes for detectors operating in a pulse counting mode. We describe the first applications of such detectors combined with CsI or SbCs photo cathodes for the detection of UV photons at room and cryogenic temperatures.

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.

Optimizing the operation of an electrostatic precipitator by developing a multipoint electrode supplied by a hybrid generator

International Nuclear Information System (INIS)

Silvestre de Ferron, A; Reess, T; Pecastaing, L; Pignolet, P; Lemont, F

2009-01-01

The authors investigated and improved the filtration efficiency of an electrostatic precipitator (ESP). A laboratory-scale pilot unit was developed to allow experimentation under conditions approaching those of the industrial ESPs used by the CEA at Marcoule (France). After elucidating the electrical phenomena and optically analysing the physical processes occurring inside the precipitator, a specific electrode was developed for use with a hybrid power supply. The experiments were based on analysing the variation over time of the electric charge injected into the particle separator, the particle mass collected at the ground electrode and the charges quantity measured on a grid in the airstream after the electrode unit. Photos were also taken under different electrical discharge conditions. The results show that combining a multipoint electrode and a hybrid generator (30 kV dc and 30 kV, 1 kHz) improves the process efficiency and significantly extends the time frame (more than 10 h) during which the process operates at optimum efficiency.

Optimizing the operation of an electrostatic precipitator by developing a multipoint electrode supplied by a hybrid generator

Energy Technology Data Exchange (ETDEWEB)

Silvestre de Ferron, A; Reess, T; Pecastaing, L; Pignolet, P [LGE, Universite de Pau, 2 avenue Angot, 64000 Pau (France); Lemont, F [CEA Marcoule, Centre de la Vallee du Rhone, 30200 Bagnols-sur-Ceze (France)

2009-05-21

The authors investigated and improved the filtration efficiency of an electrostatic precipitator (ESP). A laboratory-scale pilot unit was developed to allow experimentation under conditions approaching those of the industrial ESPs used by the CEA at Marcoule (France). After elucidating the electrical phenomena and optically analysing the physical processes occurring inside the precipitator, a specific electrode was developed for use with a hybrid power supply. The experiments were based on analysing the variation over time of the electric charge injected into the particle separator, the particle mass collected at the ground electrode and the charges quantity measured on a grid in the airstream after the electrode unit. Photos were also taken under different electrical discharge conditions. The results show that combining a multipoint electrode and a hybrid generator (30 kV dc and 30 kV, 1 kHz) improves the process efficiency and significantly extends the time frame (more than 10 h) during which the process operates at optimum efficiency.

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.

Gold leaf counter electrodes for dye-sensitized solar cells

Science.gov (United States)

Shimada, Kazuhiro; Toyoda, Takeshi

2018-03-01

In this study, a gold leaf 100 nm thin film is used as the counter electrode in dye-sensitized solar cells. The traditional method of hammering gold foil to obtain a thin gold leaf, which requires only small amounts of gold, was employed. The gold leaf was then attached to the substrate using an adhesive to produce the gold electrode. The proposed approach for fabricating counter electrodes is demonstrated to be facile and cost-effective, as opposed to existing techniques. Compared with electrodes prepared with gold foil and sputtered gold, the gold leaf counter electrode demonstrates higher catalytic activity with a cobalt-complex electrolyte and higher cell efficiency. The origin of the improved performance was investigated by surface morphology examination (scanning electron microscopy), various electrochemical analyses (cyclic voltammetry, linear sweep voltammetry, and electrochemical impedance spectroscopy), and crystalline analysis (X-ray diffractometry).

Electrical resistance tomography using steel cased boreholes as electrodes

International Nuclear Information System (INIS)

Newmark, R L; Daily, W; Ramirez, A

1999-01-01

Electrical resistance tomography (ERT) using multiple electrodes installed in boreholes has been shown to be useful for both site characterization and process monitoring. In some cases, however, installing multiple downhole electrodes is too costly (e.g., deep targets) or risky (e.g., contaminated sites). For these cases we have examined the possibility of using the steel casings of existing boreholes as electrodes. The first case we investigated used an array of steel casings as electrodes. This results in very few data and thus requires additional constraints to limit the domain of possible inverse solutions. Simulations indicate that the spatial resolution and sensitivity are understandably low but it is possible to coarsely map the lateral extent of subsurface processes such as steam floods. A hybrid case uses traditional point electrode arrays combined with long-conductor electrodes (steel casings). Although this arrangement provides more data, in many cases it results in poor reconstructions of test targets. Results indicate that this method may hold promise for low resolution imaging where steel casings can be used as electrodes

The development of hydrogen storage electrode alloys for nickel hydride batteries

Science.gov (United States)

Hong, Kuochih

The development of hydrogen storage electrode alloys in the 1980s resulted in the birth and growth of the rechargeable nickel hydride (Ni/MH) battery. In this paper we describe briefly a semi-empirical electrochemical/thermodynamic approach to develop/screen a hydrogen storage alloy for electrochemical application. More specifically we will discuss the AB x Ti/Zr-based alloys. Finally, the current state of the Ni/MH batteries including commercial manufacture processes, cell performance and applications is given.

Recovery Act: Low Cost Integrated Substrate for OLED Lighting Development

Energy Technology Data Exchange (ETDEWEB)

Benton, Scott [PPG Industries, Inc., Pittsburgh, PA (United States); Bhandari, Abhinav [PPG Industries, Inc., Pittsburgh, PA (United States)

2012-12-26

PPG pursued the development of an integrated substrate, including the anode, external, and internal extraction layers. The objective of PPG's program was to achieve cost reductions by displacing the existing expensive borosilicate or double-side polished float glass substrates and developing alternative electrodes and scalable light extraction layer technologies through focused and short-term applied research. One of the key highlights of the project was proving the feasibility of using PPG's high transmission Solarphire® float glass as a substrate to consistently achieve organic lightemitting diode (OLED) devices with good performance and high yields. Under this program, four low-cost alternatives to the Indium Tin Oxide (ITO) anode were investigated using pilot-scale magnetron sputtered vacuum deposition (MSVD) and chemical vapor deposition (CVD) technologies. The anodes were evaluated by fabricating small and large phosphorescent organic lightemitting diode (PHOLED) devices at Universal Display Corporation (UDC). The device performance and life-times comparable to commercially available ITO anodes were demonstrated. A cost-benefit analysis was performed to down-select two anodes for further low-cost process development. Additionally, PPG developed and evaluated a number of scalable and compatible internal and external extraction layer concepts such as scattering layers on the outside of the glass substrate or between the transparent anode and the glass interface. In one external extraction layer (EEL) approach, sol-gel sprayed pyrolytic coatings were deposited using lab scale equipment by hand or automated spraying of sol-gel solutions on hot glass, followed by optimizing of scattering with minimal absorption. In another EEL approach, PPG tested large-area glass texturing by scratching a glass surface with an abrasive roller and acid etching. Efficacy enhancements of 1.27x were demonstrated using white PHOLED devices for 2.0mm substrates which are

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

Development of a time projection chamber with micro-pixel electrodes

International Nuclear Information System (INIS)

Kubo, Hidetoshi; Miuchi, Kentaro; Nagayoshi, Tsutomu; Ochi, Atsuhiko; Orito, Reiko; Takada, Atsushi; Tanimori, Toru; Ueno, Masaru

2003-01-01

A time projection chamber (TPC) based on a gaseous chamber with micro-pixel electrodes (μ-PIC) has been developed for measuring three-dimensional tracks of charged particles. The μ-PIC with a detection area of 10x10 cm 2 consists of a double-sided printing circuit board. Anode pixels are formed with 0.4 mm pitch on strips aligned perpendicular to the cathode strips in order to obtain a two-dimensional position. In the TPC with drift length of 8 cm, 4 mm wide field cage electrodes are aligned at 1 mm spaces and a uniform electric field of about 0.4 kV/cm is produced. For encoding of the three-dimensional position a synchronous readout system has been developed using Field Programmable Gate Arrays with 40 MHz clock. This system enables us to reconstruct the three-dimensional track of the particle at successive points like a cloud chamber even at high event rate. The drift velocity of electrons in the TPC was measured with the tracks of cosmic muons for 3 days, during which the TPC worked stably with the gas gain of 3000. With a radioisotope of gamma-ray source the three-dimensional track of a Compton scattered electron was taken successfully

The influence of the synthesis method of Ti/RuO2 electrodes on their stability and catalytic activity for electrochemical oxidation of the pesticide carbaryl

International Nuclear Information System (INIS)

Santos, T.É.S.; Silva, R.S.; Carlesi Jara, C.; Eguiluz, K.I.B.; Salazar-Banda, G.R.

2014-01-01

In this study, we developed dimensionally stable anodes of titanium covered with ruthenium oxides (Ti/RuO 2 ) using sol–gel, Pechini and ionic liquid (IL) methodologies. The electrochemical efficiency of these electrodes was then evaluated regarding electrochemical degradation of the pesticide carbaryl. The UV–visible spectroscopy measurements showed that the electrodes obtained by the IL and Pechini methods were more effective at pesticide degradation compared with the sol–gel electrode, especially at high current density values. Carbaryl degradation after 2 h of electrolysis at 30 mA cm −2 was 96.4% and 95.5% for the electrodes obtained by the IL and Pechini methods, respectively, while the degradation was 65.0% for the electrodes obtained by the sol–gel method. Additionally, the electrodes prepared by the IL and Pechini methods showed greater physical and electrochemical stability when compared to electrodes obtained by the sol–gel method. Electrodes prepared by the IL method with a few covering layers (three) achieved an elevated and constant area in a more efficient way than electrodes prepared by the Pechini and sol–gel methods. This fact can be attributed to the higher viscosity of the ionic liquid-based precursor solution, which transfers a higher amount of Ru in one single layer, compared to the other methods studied, thus reducing the time for synthesis, the number of calcination steps and the production costs of electrodes. - Highlights: • We developed dimensionally stable anodes containing ruthenium oxides. • Sol–gel, Pechini and ionic liquid methodologies were used. • The ionic liquid method covers the surfaces more efficiently and with few layers. • The proposed method reduces the time and production cost for synthesis of electrodes. • The electrodes synthesized present high stability and pesticide degradation activity

Axle-sleeve Structured MWCNTs/Polyaniline Composite Film as Cost-effective Counter-Electrodes for High Efficient Dye-Sensitized Solar Cells

International Nuclear Information System (INIS)

Niu, Haihong; Qin, Shengxian; Mao, Xiaoli; Zhang, Shouwei; Wang, Renbao; Wan, Lei; Xu, Jinzhang; Miao, Shiding

2014-01-01

Graphical abstract: Axle-sleeve structured composite materials made with carbon nanotubes and polyaniline were prepared via a co-polymerization strategy. The composite materials were employed as cost-effective counter electrode modifier in dye-sensitized solar cells which demonstrate a comparable photo-to-electron conversion efficiency as the Pt catalyst. - Highlights: • Axle-sleeve structured MWCNT/PANI composite was prepared. • The optimum mass ratio of MWCNT/ANIranges between 1:3 and 1:1. • The π-π drive force was confirmed by spectroscopicmeans. • The polymerization time of 12∼24 hrs affords the highest conversion efficiency. • The DSSCs assembled with the MWCNTs/PANI CEs exhibit a comparable η(7.21%) as that with Pt CE (7.59%). - Abstract: Axle-sleeve structured composite materials made with multi-walled carbon nanotubes (MWCNTs) and polyaniline (PANI) were prepared, characterized, and employed as cost-effective counter electrodes (CEs) in dye-sensitized solar cells (DSSCs). The composite was synthesized by co-polymerization of aniline with carboxylated MWCNTs by using ammonium persulfate in the acidic medium. Thin films of MWCNTs/PANI were prepared via a spin coating technique followed by thermal treatment in N 2 atmosphere. The micro-structure of the composite was studied by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) linked with energy dispersive spectroscopy (EDS). The coating layer of PANI on the MWCNTs and new-formed chemical bonds between MWCNTs and PANI was studied by UV-Vis absorption, X-ray photoelectron spectroscopy (XPS), Raman and FT-IR spectroscopic means. The effect of the multiple-level porosity or the axle-sleeve structures in the composite of MWCNTs/PANI on the electro-catalytic activity was investigated by cyclic voltammetry (CV) and electrochemical impedance spectroscopic (EIS) analysis. The DSSCs assembled with MWCNTs/PANI as CEs exhibit a comparable energy conversion efficiency (η) of 7

Offset-electrode profile acquisition strategy for electrical resistivity tomography

Science.gov (United States)

Robbins, Austin R.; Plattner, Alain

2018-04-01

We present an electrode layout strategy that allows electrical resistivity profiles to image the third dimension close to the profile plane. This "offset-electrode profile" approach involves laterally displacing electrodes away from the profile line in an alternating fashion and then inverting the resulting data using three-dimensional electrical resistivity tomography software. In our synthetic and field surveys, the offset-electrode method succeeds in revealing three-dimensional structures in the vicinity of the profile plane, which we could not achieve using three-dimensional inversions of linear profiles. We confirm and explain the limits of linear electrode profiles through a discussion of the three-dimensional sensitivity patterns: For a homogeneous starting model together with a linear electrode layout, all sensitivities remain symmetric with respect to the profile plane through each inversion step. This limitation can be overcome with offset-electrode layouts by breaking the symmetry pattern among the sensitivities. Thanks to freely available powerful three-dimensional resistivity tomography software and cheap modern computing power, the requirement for full three-dimensional calculations does not create a significant burden and renders the offset-electrode approach a cost-effective method. By offsetting the electrodes in an alternating pattern, as opposed to laying the profile out in a U-shape, we minimize shortening the profile length.

Electrode Induced Removal and Recovery of Uranium (VI) from Acidic Subsurfaces

Energy Technology Data Exchange (ETDEWEB)

Gregory, Kelvin [Carnegie Mellon University

2013-08-12

The overarching objective of this research is to provide an improved understanding of how aqueous geochemical conditions impact the removal of U and Tc from groundwater and how engineering design may be utilized to optimize removal of these radionuclides. Experiments were designed to address the unique conditions in Area 3 of ORNL while also providing broader insight into the geochemical effectors of the removal rates and extent for U and Tc. The specific tasks of this work were to: 1) quantify the impact of common aqueous geochemical and operational conditions on the rate and extent of U removal and recovery from water, 2) investigate the removal of Tc with polarized graphite electrode, and determine the influence of geochemical and operational conditions on Tc removal and recovery, 3) determine whether U and Tc may be treated simultaneous from Area 3 groundwater, and examine the bench-scale performance of electrode-based treatment, and 4) determine the capacity of graphite electrodes for U(VI) removal and develop a mathematical, kinetic model for the removal of U(VI) from aqueous solution. Overall the body of work suggests that an electrode-based approach for the remediation of acidic subsurface environments, such as those observed in Area 3 of ORNL may be successful for the removal for both U(VI) and Tc. Carbonaceous (graphite) electrode materials are likely to be the least costly means to maximize removal rates and efficiency by maximizing the electrode surface area.

Ni-Zn electrodes for hydrogen production by acid electrolysis; Eletrodos de Ni-Zn para producao de hidrogenio por eletrolise acida

Energy Technology Data Exchange (ETDEWEB)

Torres, C.S.; Malfatti, C.F., E-mail: camilator@gmail.com [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre (Brazil). Departamento de Metalurgia. Lab. de Pesquisa em Corrosao

2014-07-01

Hydrogen production by electrolysis of water, have an important role in countries that have great renewable potential for electricity production. The electrolysis of water has been proposed to use the excess capacity of hydroelectric plants. However, to improve process efficiency, research has been undertaken to improve the catalytic reduction reaction of hydrogen from the development of electrodes with better performance. Thus, the selection of low cost electrode materials with good electrocatalytic activity is required. In this work, the hydrogen evolution reaction (HER) employing electrodes of Ni-Zn and Ni was investigated. Morphological characterization of the electrodes was performed using SEM/ EDX and profilometry and electrochemical behavior was evaluated by cathodic polarization curves. The results showed that the addition of Zn promotes the increase the electrocatalytic activity of HER compared to nickel electrode. (author)

Development of solid state reference electrodes and pH sensors for monitoring nuclear reactor cooling water systems

International Nuclear Information System (INIS)

Hettiarachchi, S.; Makela, K.; Macdonald, D.D.

1991-01-01

The growing interest in the electrochemical and corrosion behavior of structural alloys in high temperature aqueous systems has stimulated research in the design and testing of reliable reference electrodes and pH sensors for use in such environments. External reference electrodes have been successfully used in the recent years in high temperature aqueous environments, although their long-term stability is questionable. On the other hand, more reliable pH sensors have been developed by various workers for high temperature applications, the major drawback being their sensitivity to dissolved hydrogen, oxygen and other redox species. This paper describes the development of both solid-state reference electrodes and yttria-stabilized zirconia (YSZ) pH sensors for application in high temperature aqueous systems. (author)

Development of durable and efficient electrodes for large-scale alkaline water electrolysis

DEFF Research Database (Denmark)

Kjartansdóttir, Cecilia Kristin; Nielsen, Lars Pleth; Møller, Per

2013-01-01

A new type of electrodes for alkaline water electrolysis is produced by physical vapour depositing (PVD) of aluminium onto a nickel substrate. The PVD Al/Ni is heat-treated to facilitate alloy formation followed by a selective aluminium alkaline leaching. The obtained porous Ni surface is uniform...... and characterized by a unique interlayer adhesion, which is critical for industrial application. IR-compensated polarisation curves prepared in a half-cell setup with 1 M KOH electrolyte at room temperature reveals that at least 400 mV less potential is needed to decompose water into hydrogen and oxygen...... produced bipolar electrolyser stack. The developed electrodes showed stable behaviour under intermittent operation for over 9000 h indicating no serious deactivation in the density of active sites....

Using quasi-elastic neutron diffraction to study positive electrode for lithium and sodium-ion batteries

International Nuclear Information System (INIS)

Pramudita, James C.; Sharma, Neeraj

2015-01-01

Sodium-ion batteries has recently been proposed as the alternative for lithium-ion batteries to be the low cost energy storage system. However, challenges still remains for the development of sodium-ion batteries. Optimization of electrode materials and electrolyte capable of insertion/extraction of sodium-ion in a safe and economic way under high current density is needed in order to produce commercially viable sodium-ion batteries. While possible positive electrode material is more prevalent than negative electrode material, many of these material still need further understanding. Quasi-elastic Neutron Scatteringis a technique that utilize the inelastic Neutron Scatteringthat can be used to study solid-state diffusion in materials. This technique can be used to study the diffusion of sodium-ion under electric field through the electrolyte and positive electrode materials in order to further understand the mechanism of sodium insertion/extraction in a working battery. This technique can also be used to study available positive electrode material for lithium-ion batteries to further understand the mechanism of lithium-ion diffusion in current working lithiumion batteries.

Nanocomposite electrodes for smartphone enabled healthcare garments: e-bra and smart vest

Science.gov (United States)

Kumar, Prashanth S.; Rai, Pratyush; Oh, Sechang; Kwon, Hyeokjun; Varadan, Vijay K.

2012-10-01

The financial burden of hospital readmissions and treatment of chronic cardiac diseases are global concerns. Point of Care (POC) has been presented as an elegant solution for healthcare cost reduction. However, large scale adoption of POC systems requires an intuitive, unobtrusive and easy to use health monitoring system from patient's perspective. Healthcare textiles are sensor systems mounted on textile platform that function as wearable unobtrusive health monitoring systems. Although much work has been done in the development and demonstration of textile mounted monitoring systems, material and production costs are still high. Nanomaterials based devices and technology can be employed in these healthcare textiles for improved electrical characteristics of the sensors, lowered cost due to less material consumption and compatibility to varied manufacturing techniques. Carbon nanotube composite ink based printable conductive electrodes is such a textile adaptable nanomaterial technology. Screen printed Nanocomposite electrodes made of carbon nanotubes and an acrylic polymer can be used in undergarments like vests and brassieres, for cardiac biopotential (Electrocardiography, ECG) sensing. A Bluetooth module and a smartphone can then be used to provide cyber-infrastructure connectivity for the healthcare data from these healthcare garments. They can be used to monitor young or elderly recuperating /convalescent patients either in hospital or at home, or they can be used by young athletes to monitor important physiological parameters to better design their training or fitness program. In this study, we evaluate screen printed CNT-acrylic Nanocomposite electrodes for ECG signal quality and any CNT leaching hazard that might lead to skin toxicity.

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.

The Electrode Modality Development in Pulsed Electric Field Treatment Facilitates Biocellular Mechanism Study and Improves Cancer Ablation Efficacy

OpenAIRE

Cen, Chao; Chen, Xinhua

2017-01-01

Pulsed electric field treatment is now widely used in diverse biological and medical applications: gene delivery, electrochemotherapy, and cancer therapy. This minimally invasive technique has several advantages over traditional ablation techniques, such as nonthermal elimination and blood vessel spare effect. Different electrodes are subsequently developed for a specific treatment purpose. Here, we provide a systematic review of electrode modality development in pulsed electric field treatme...

Efficient Semitransparent Perovskite Solar Cells Using a Transparent Silver Electrode and Four-Terminal Perovskite/Silicon Tandem Device Exploration

Directory of Open Access Journals (Sweden)

Dazheng Chen

2018-01-01

Full Text Available Four-terminal tandem solar cells employing a perovskite top cell and crystalline silicon (Si bottom cell offer a simpler pathway to surpass the efficiency limit of market-leading single-junction silicon solar cells. To obtain cost-effective top cells, it is crucial to develop transparent conductive electrodes with low parasitic absorption and manufacturing cost. The commonly used indium tin oxide (ITO shows some drawbacks, like the increasing prices and high-energy magnetron sputtering process. Transparent metal electrodes are promising candidates owing to the simple evaporation process, facile process conditions, and high conductivity, and the cheaper silver (Ag electrode with lower parasitic absorption than gold may be the better choice. In this work, efficient semitransparent perovskite solar cells (PSCs were firstly developed by adopting the composite cathode of an ultrathin Ag electrode at its percolation threshold thickness (11 nm, a molybdenum oxide optical coupling layer, and a bathocuproine interfacial layer. The resulting power conversion efficiency (PCE is 13.38% when the PSC is illuminated from the ITO side and the PCE is 8.34% from the Ag side, and no obvious current hysteresis can be observed. Furthermore, by stacking an industrial Si bottom cell (PCE = 14.2% to build a four-terminal architecture, the overall PCEs of 17.03% (ITO side and 11.60% (Ag side can be obtained, which are 27% and 39% higher, respectively, than those of the perovskite top cell. Also, the PCE of the tandem cell has exceeded that of the reference Si solar cell by about 20%. This work provides an outlook to fabricate high-performance solar cells via the cost-effective pathway.

The influence of the synthesis method of Ti/RuO{sub 2} electrodes on their stability and catalytic activity for electrochemical oxidation of the pesticide carbaryl

Energy Technology Data Exchange (ETDEWEB)

Santos, T. É.S. [Laboratório de Eletroquímica e Nanotecnologia, Instituto de Tecnologia e Pesquisa (ITP)/Programa de Pós-Graduação em Engenharia de Processos, Universidade Tiradentes, 49032–490 Aracaju, SE (Brazil); Silva, R. S. [Laboratório de Materiais Cerâmicos Avançados, Departamento de Física, Universidade Federal de Sergipe, 49.100-000 São Cristóvão, SE (Brazil); Carlesi Jara, C. [Escuela de Ingeniería Química, Pontificia Universidad Católica de Valparaíso, Av. Brasil No 2147, 2362804 Valparaíso (Chile); Eguiluz, K. I.B. [Laboratório de Eletroquímica e Nanotecnologia, Instituto de Tecnologia e Pesquisa (ITP)/Programa de Pós-Graduação em Engenharia de Processos, Universidade Tiradentes, 49032–490 Aracaju, SE (Brazil); Salazar-Banda, G.R., E-mail: gianrsb@gmail.com [Laboratório de Eletroquímica e Nanotecnologia, Instituto de Tecnologia e Pesquisa (ITP)/Programa de Pós-Graduação em Engenharia de Processos, Universidade Tiradentes, 49032–490 Aracaju, SE (Brazil)

2014-11-14

In this study, we developed dimensionally stable anodes of titanium covered with ruthenium oxides (Ti/RuO{sub 2}) using sol–gel, Pechini and ionic liquid (IL) methodologies. The electrochemical efficiency of these electrodes was then evaluated regarding electrochemical degradation of the pesticide carbaryl. The UV–visible spectroscopy measurements showed that the electrodes obtained by the IL and Pechini methods were more effective at pesticide degradation compared with the sol–gel electrode, especially at high current density values. Carbaryl degradation after 2 h of electrolysis at 30 mA cm{sup −2} was 96.4% and 95.5% for the electrodes obtained by the IL and Pechini methods, respectively, while the degradation was 65.0% for the electrodes obtained by the sol–gel method. Additionally, the electrodes prepared by the IL and Pechini methods showed greater physical and electrochemical stability when compared to electrodes obtained by the sol–gel method. Electrodes prepared by the IL method with a few covering layers (three) achieved an elevated and constant area in a more efficient way than electrodes prepared by the Pechini and sol–gel methods. This fact can be attributed to the higher viscosity of the ionic liquid-based precursor solution, which transfers a higher amount of Ru in one single layer, compared to the other methods studied, thus reducing the time for synthesis, the number of calcination steps and the production costs of electrodes. - Highlights: • We developed dimensionally stable anodes containing ruthenium oxides. • Sol–gel, Pechini and ionic liquid methodologies were used. • The ionic liquid method covers the surfaces more efficiently and with few layers. • The proposed method reduces the time and production cost for synthesis of electrodes. • The electrodes synthesized present high stability and pesticide degradation activity.

Spatiotemporal electrochemical measurements across an electric double layer capacitor electrode with application to aqueous sodium hybrid batteries

Science.gov (United States)

Tully, Katherine C.; Whitacre, Jay F.; Litster, Shawn

2014-02-01

This paper presents in-situ spatiotemporal measurements of the electrolyte phase potential within an electric double layer capacitor (EDLC) negative electrode as envisaged for use in an aqueous hybrid battery for grid-scale energy storage. The ultra-thick electrodes used in these batteries to reduce non-functional material costs require sufficiently fast through-plane mass and charge transport to attain suitable charging and discharging rates. To better evaluate the through-plane transport, we have developed an electrode scaffold (ES) for making in situ electrolyte potential distribution measurements at discrete known distances across the thickness of an uninterrupted EDLC negative electrode. Using finite difference methods, we calculate local current, volumetric charging current and charge storage distributions from the spatiotemporal electrolyte potential measurements. These potential distributions provide insight into complex phenomena that cannot be directly observed using other existing methods. Herein, we use the distributions to identify areas of the electrode that are underutilized, assess the effects of various parameters on the cumulative charge storage distribution, and evaluate an effectiveness factor for charge storage in EDLC electrodes.

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.

Time-dependent simulation of plasma and electrodes in high-intensity discharge lamps with different electrode shapes

CERN Document Server

Flesch, P

2003-01-01

The subject of this paper is the modelling of d.c. and a.c. high-intensity Hg-discharge lamps with differently shaped electrodes. Different arc attachments on the electrodes are studied and insight for the development of new electrodes is gained. The model includes the entire discharge plasma (plasma column, hot plasma spots in front of electrodes, near-electrode non-LTE-plasma) as well as anode and cathode. No subdivision of the discharge space into different regions is necessary (like space charge layer, ionization zone, plasma column). This is achieved by using a differential equation for a non-LTE electrical conductivity which is applicable for local thermal equilibrium (LTE-)regions as well as for non-LTE plasma regions close to the electrodes in a high pressure plasma. Modelling results for a 0.6 MPa mercury discharge considering six different electrode shapes (anode and cathode) are presented and compared with experimental results. The electrodes have different diameters and different electrode tips, s...

Microarray Dot Electrodes Utilizing Dielectrophoresis for Cell Characterization

Directory of Open Access Journals (Sweden)

Fatimah Ibrahim

2013-07-01

Full Text Available During the last three decades; dielectrophoresis (DEP has become a vital tool for cell manipulation and characterization due to its non-invasiveness. It is very useful in the trend towards point-of-care systems. Currently, most efforts are focused on using DEP in biomedical applications, such as the spatial manipulation of cells, the selective separation or enrichment of target cells, high-throughput molecular screening, biosensors and immunoassays. A significant amount of research on DEP has produced a wide range of microelectrode configurations. In this paper; we describe the microarray dot electrode, a promising electrode geometry to characterize and manipulate cells via DEP. The advantages offered by this type of microelectrode are also reviewed. The protocol for fabricating planar microelectrodes using photolithography is documented to demonstrate the fast and cost-effective fabrication process. Additionally; different state-of-the-art Lab-on-a-Chip (LOC devices that have been proposed for DEP applications in the literature are reviewed. We also present our recently designed LOC device, which uses an improved microarray dot electrode configuration to address the challenges facing other devices. This type of LOC system has the capability to boost the implementation of DEP technology in practical settings such as clinical cell sorting, infection diagnosis, and enrichment of particle populations for drug development.

Potassium-Based Dual Ion Battery with Dual-Graphite Electrode.

Science.gov (United States)

Fan, Ling; Liu, Qian; Chen, Suhua; Lin, Kairui; Xu, Zhi; Lu, Bingan

2017-08-01

A potassium ion battery has potential applications for large scale electric energy storage systems due to the abundance and low cost of potassium resources. Dual graphite batteries, with graphite as both anode and cathode, eliminate the use of transition metal compounds and greatly lower the overall cost. Herein, combining the merits of the potassium ion battery and dual graphite battery, a potassium-based dual ion battery with dual-graphite electrode is developed. It delivers a reversible capacity of 62 mA h g -1 and medium discharge voltage of ≈3.96 V. The intercalation/deintercalation mechanism of K + and PF 6 - into/from graphite is proposed and discussed in detail, with various characterizations to support. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Sustainable Materials for Sustainable Energy Storage: Organic Na Electrodes

Science.gov (United States)

Oltean, Viorica-Alina; Renault, Stéven; Valvo, Mario; Brandell, Daniel

2016-01-01

In this review, we summarize research efforts to realize Na-based organic materials for novel battery chemistries. Na is a more abundant element than Li, thereby contributing to less costly materials with limited to no geopolitical constraints while organic electrode materials harvested from biomass resources provide the possibility of achieving renewable battery components with low environmental impact during processing and recycling. Together, this can form the basis for truly sustainable electrochemical energy storage. We explore the efforts made on electrode materials of organic salts, primarily carbonyl compounds but also Schiff bases, unsaturated compounds, nitroxides and polymers. Moreover, sodiated carbonaceous materials derived from biomasses and waste products are surveyed. As a conclusion to the review, some shortcomings of the currently investigated materials are highlighted together with the major limitations for future development in this field. Finally, routes to move forward in this direction are suggested. PMID:28773272

Reliability Modeling Development and Its Applications for Ceramic Capacitors with Base-Metal Electrodes (BMEs)

Science.gov (United States)

Liu, Donhang

2014-01-01

This presentation includes a summary of NEPP-funded deliverables for the Base-Metal Electrodes (BMEs) capacitor task, development of a general reliability model for BME capacitors, and a summary and future work.

Embedded 32-bit Differential Pulse Voltammetry (DPV) Technique for 3-electrode Cell Sensing

Science.gov (United States)

N, Aqmar N. Z.; Abdullah, W. F. H.; Zain, Z. M.; Rani, S.

2018-03-01

This paper addresses the development of differential pulse voltammetry (DPV) embedded algorithm using an ARM cortex processor with new developed potentiostat circuit design for in-situ 3-electrode cell sensing. This project is mainly to design a low cost potentiostat for the researchers in laboratories. It is required to develop an embedded algorithm for analytical technique to be used with the designed potentiostat. DPV is one of the most familiar pulse technique method used with 3-electrode cell sensing in chemical studies. Experiment was conducted on 10mM solution of Ferricyanide using the designed potentiostat and the developed DPV algorithm. As a result, the device can generate an excitation signal of DPV from 0.4V to 1.2V and produced a peaked voltammogram with relatively small error compared to the commercial potentiostat; which is only 6.25% difference in peak potential reading. The design of potentiostat device and its DPV algorithm is verified.

Development and electrochemistry of a novel Ag/AgCl reference electrode suitable for mixed chloride-fluoride melts

International Nuclear Information System (INIS)

Pal, Rahul; Ananthasivan, K.; Anthonysamy, S.; Ganesan, V.

2011-01-01

Research highlights: → An Ag/AgCl reference electrode for mixed chloride-fluoride melts was developed. → Non-polarizability, reversibility and stability of the electrode were tested. → Dependence of emf vs T for Fe/Fe 2+ and Ni/Ni 2+ couples in KCl-KF melt was reported. - Abstract: Accurate values of electrode potentials are useful in understanding the electrodeposition of boron from a melt containing fluoride, chloride and fluoroborate, as well as in the determination of the thermodynamic properties of this system. A suitable reference electrode for use with this molten mixture is essential for the determination of these potentials. An Ag/AgCl reference electrode was fabricated for this purpose and its stability, reversibility and polarizability in a melt containing chloride and fluoride were studied in the temperature range 1073-1123 K. Cyclic-voltammograms (CVs) of this melt on a platinum working electrode were recorded at regular intervals over a period of 12 h. These CVs did not show any appreciable variation with time, indicating the stability of this reference electrode. The reversibility of this reference electrode was established by carrying out a micropolarization test. Cathodic and anodic polarization tests were carried out by passing a current of 1 mA and 5 mA through the cell for a duration of 300 s. After these polarization tests, the electrode swung back to its equilibrium potential within about 250 s. Reduction potentials of Fe 2+ /Fe and Ni 2+ /Ni couples in the KF-KCl melt were measured for the first time.

Materials Science of Electrodes and Interfaces for High-Performance Organic Photovoltaics

Energy Technology Data Exchange (ETDEWEB)

Marks, Tobin [Northwestern Univ., Evanston, IL (United States)

2016-11-18

The science of organic photovoltaic (OPV) cells has made dramatic advances over the past three years with power conversion efficiencies (PCEs) now reaching ~12%. The upper PCE limit of light-to-electrical power conversion for single-junction OPVs as predicted by theory is ~23%. With further basic research, the vision of such devices, composed of non-toxic, earth-abundant, readily easily processed materials replacing/supplementing current-generation inorganic solar cells may become a reality. Organic cells offer potentially low-cost, roll-to-roll manufacturable, and durable solar power for diverse in-door and out-door applications. Importantly, further gains in efficiency and durability, to that competitive with inorganic PVs, will require fundamental, understanding-based advances in transparent electrode and interfacial materials science and engineering. This team-science research effort brought together an experienced and highly collaborative interdisciplinary group with expertise in hard and soft matter materials chemistry, materials electronic structure theory, solar cell fabrication and characterization, microstructure characterization, and low temperature materials processing. We addressed in unconventional ways critical electrode-interfacial issues underlying OPV performance -- controlling band offsets between transparent electrodes and organic active-materials, addressing current loss/leakage phenomena at interfaces, and new techniques in cost-effective low temperature and large area cell fabrication. The research foci were: 1) Theory-guided design and synthesis of advanced crystalline and amorphous transparent conducting oxide (TCO) layers which test our basic understanding of TCO structure-transport property relationships, and have high conductivity, transparency, and tunable work functions but without (or minimizing) the dependence on indium. 2) Development of theory-based understanding of optimum configurations for the interfaces between oxide electrodes

Microwave exposure as a fast and cost-effective alternative of oxygen plasma treatment of indium-tin oxide electrode for application in organic solar cells

Science.gov (United States)

Soultati, Anastasia; Kostis, Ioannis; Papadimitropoulos, Giorgos; Zeniou, Angelos; Gogolides, Evangelos; Alexandropoulos, Dimitris; Vainos, Nikos; Davazoglou, Dimitris; Speliotis, Thanassis; Stathopoulos, Nikolaos A.; Argitis, Panagiotis; Vasilopoulou, Maria

2017-12-01

Pre-treatment methods are commonly employed to clean as well as to modify electrode surfaces. Many previous reports suggest that modifying the surface properties of indium tin oxide (ITO) by oxygen plasma treatment is a crucial step for the fabrication of high performance organic solar cells. In this work, we propose a fast and cost-effective microwave exposure step for the modification of the surface properties of ITO anode electrodes used in organic solar cells. It is demonstrated that a short microwave exposure improves the hydrophilicity and reduces the roughness of the ITO surface, as revealed by contact angle and atomic force microscopy (AFM) measurements, respectively, leading to a better quality of the PEDOT:PSS film coated on top of it. Similar results were obtained with the commonly used oxygen plasma treatment of ITO suggesting that microwave exposure is an effective process for modifying the surface properties of ITO with the benefits of low-cost, easy and fast processing. In addition, the influence of the microwave exposure of ITO anode electrode on the performance of an organic solar cell based on the poly(3-hexylthiophene):[6,6]-phenyl C70 butyric acid methyl ester (P3HT:PC70BM) blend is investigated. The 71% efficiency enhancement obtained in the microwave annealed-ITO based device as compared to the device with the as-received ITO was mainly attributed to the improvement in the short circuit current (J sc) and decreased leakage current caused by the reduced series and the increased shunt resistances and also by the higher charge generation efficiency, and the reduced recombination losses.

A Newly Developed Perfused Umbrella Electrode for Radiofrequency Ablation: An Ex Vivo Evaluation Study in Bovine Liver

International Nuclear Information System (INIS)

Bruners, Philipp; Pfeffer, Jochen; Kazim, Rana M.; Guenther, Rolf W.; Schmitz-Rode, Thomas; Mahnken, Andreas H.

2007-01-01

The purpose of this study was to evaluate the effectiveness of a newly developed perfused monopolar radiofrequency (RF) probe with an umbrella-shaped array. A perfused umbrella-shaped monopolar RF probe based on a LeVeen electrode (Boston Scientific Corp., Natick, MA, USA) with a 3-cm array diameter was developed. Five different configurations of this electrode were tested: (a) perfusion channel/endhole, (b) perfusion channel/endhole + sideholes, (c) 1 cm insulation removed at the tip, (d) 1 cm insulation removed at the tip + perfusion channel/endhole, and (e) 1 cm insulation removed at the tip + perfusion channel/endhole + sideholes. An unmodified LeVeen electrode served as a reference standard. RF ablations were performed in freshly excised bovine liver using a commercial monopolar RF system with a 200-W generator (RF 3000; Boston Scientific Corp.). Each electrode was tested 10 times applying the vendor's recommended ablation protocol combined with the preinjection of 2 ml 0.9% saline. Volumes and shapes of the lesions were compared. Lesions generated with the original LeVeen electrode showed a mean volume of 12.74 ± 0.52 cm 3 . Removing parts of the insulation led to larger coagulation volumes (22.65 ± 2.12 cm 3 ). Depending on the configuration, saline preinjection resulted in a further increase in coagulation volume (25.22 ± 3.37 to 31.28 ± 2.32 cm 3 ). Besides lesion volume, the shape of the ablation zone was influenced by the configuration of the electrode used. We conclude that saline preinjection in combination with increasing the active tip length of the umbrella-shaped LeVeen RF probe allows the reliable ablation of larger volumes in comparison to the originally configured electrode

Flexible electroluminescent device with inkjet-printed carbon nanotube electrodes

Science.gov (United States)

Azoubel, Suzanna; Shemesh, Shay; Magdassi, Shlomo

2012-08-01

Carbon nanotube (CNTs) inks may provide an effective route for producing flexible electronic devices by digital printing. In this paper we report on the formulation of highly concentrated aqueous CNT inks and demonstrate the fabrication of flexible electroluminescent (EL) devices by inkjet printing combined with wet coating. We also report, for the first time, on the formation of flexible EL devices in which all the electrodes are formed by inkjet printing of low-cost multi-walled carbon nanotubes (MWCNTs). Several flexible EL devices were fabricated by using different materials for the production of back and counter electrodes: ITO/MWCNT and MWCNT/MWCNT. Transparent electrodes were obtained either by coating a thin layer of the CNTs or by inkjet printing a grid which is composed of empty cells surrounded by MWCNTs. It was found that the conductivity and transparency of the electrodes are mainly controlled by the MWCNT film thickness, and that the dominant factor in the luminance intensity is the transparency of the electrode.

Graphene Oxide/ Ruthenium Oxide Composites for Supercapacitors Electrodes

Science.gov (United States)

Amir, Fatima

Supercapacitors are electrical energy storage devices with high power density, high rate capability, low maintenance cost, and long life cycle. They complement or replace batteries in harvesting applications when high power delivery is needed. An important improvement in performance of supercapacitors has been achieved through recent advances in the development of new nanostructured materials. Here we will discuss the fabrication of graphene oxide/ ruthenium oxide supercacitors electrodes including electrophoretic deposition. The morphology and structure of the fabricated electrodes were investigated and will be discussed. The electrochemical properties were determined using cyclic voltammetry and galvanostatic charge/discharge techniques and the experiments that demonstrate the excellent capacitive properties of the obtained supercapacitors will also be discussed. The fabrication and characterization of the samples were performed at the Center of Functional Nanomaterials at Brookhaven National Lab. The developed approaches in our study represent an exciting direction for designing the next generation of energy storage devices. This work was supported in part by the U.S. Department of Energy through the Visiting Faculty Program and the research used resources of the Center for Functional Nanomaterials at Brookhaven National Laboratory.

High surface area bio-waste based carbon as a superior electrode for vanadium redox flow battery

Science.gov (United States)

Maharjan, Makhan; Bhattarai, Arjun; Ulaganathan, Mani; Wai, Nyunt; Oo, Moe Ohnmar; Wang, Jing-Yuan; Lim, Tuti Mariana

2017-09-01

Activated carbon (AC) with high surface area (1901 m2 g-1) is synthesized from low cost bio-waste orange (Citrus sinensis) peel for vanadium redox flow battery (VRB). The composition, structure and electrochemical properties of orange peel derived AC (OP-AC) are characterized by elemental analyzer, field emission-scanning electron microscopy, X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, cyclic voltammetry (CV), and electrochemical impedance spectroscopy. CV results show that OP-AC coated bipolar plate demonstrates improved electro-catalytic activity in both positive and negative side redox couples than the pristine bipolar plate electrode and this is ascribed to the high surface area of OP-AC which provides effective electrode area and better contact between the porous electrode and bipolar plate. Consequently, the performance of VRB in a static cell shows higher energy efficiency for OP-AC electrode than the pristine electrode at all current densities tested. The results suggest the OP-AC to be a promising electrode for VRB applications and can be incorporated into making conducting plastics electrode to lower the VRB cell stack weight and cost.

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

Analysis of oxidation of self-baking electrodes (Soederberg electrodes) by means of three-dimensional model

Science.gov (United States)

Pashnin, S. V.

2017-10-01

The paper presents the methodology and results of the development of the temperature dependence of the oxidation speed of the self-baking electrode (Soederberg Electrodes) in the ore-thermal furnaces. For the study of oxidation, the working ends of the self-baking electrodes, which were taken out from the ore-thermal furnaces after their scabbings, were used. The temperature of the electrode surface by its height was calculated with the help of the mathematical model of heat work of self-baking electrode. The comparison of electrode surface temperatures with the speed of oxidation of the electrode allowed one to obtain the temperature dependency of the oxidation of the lateral electrode surface. Comparison of the experimental data, obtained in the laboratory by various authors, showed their qualitative coincidence with results of calculations of the oxidation rate presented in this article. With the help of the mathematical model of temperatures fields of electrode, the calculations of the sizes of the cracks, appearing after burnout ribs, were performed. Calculations showed that the sizes of the cracks after the ribs burnout, calculated by means of the obtained temperature dependence, coincide with the experimental data with sufficient accuracy.

Development of powder diffraction anomalous fine structure method and applications to electrode materials for rechargeable batteries

International Nuclear Information System (INIS)

Kawaguchi, Tomoya; Fukuda, Katsutoshi; Oishi, Masatsugu; Ichitsubo, Tetsu; Matsubara, Eiichiro; Mizuki, Jun'ichiro

2015-01-01

A powder diffraction anomalous fine structure (P-DAFS) method is developed both in analytical and experimental techniques and applied to cathode materials for lithium ion batteries. The DAFS method, which is an absorption spectroscopic technique through a scattering measurement, enables us to analyze the chemical states and the local structures of a certain element at different sites, thanks to the nature of x-ray diffraction, where the contributions from each site are different at each diffraction. Electrode materials for rechargeable batteries frequently exhibit the interchange between Li and a transition metal, which is known as the cation mixing phenomena. This cation mixing significantly affects the whole electrode properties; therefore, the site-distinguished understanding of the roles of the transition metal is essential for further material design by controlling and positively utilizing this cation mixing phenomenon. However, the developments of the P-DAFS method are required for the applications to the practical materials such as the electrode materials. In the present study, a direct analysis technique to extract the absorption spectrum from the scattering without using the conventional iterative calculations, fast and accurate measurement techniques of the P-DAFS method, and applications to a typical electrode material of Li 1-x Ni 1+x O 2 , which exhibits the significant cation mixing, are described. (author)

High-performance NiO/Ag/NiO transparent electrodes for flexible organic photovoltaic cells.

Science.gov (United States)

Xue, Zhichao; Liu, Xingyuan; Zhang, Nan; Chen, Hong; Zheng, Xuanming; Wang, Haiyu; Guo, Xiaoyang

2014-09-24

Transparent electrodes with a dielectric-metal-dielectric (DMD) structure can be implemented in a simple manufacturing process and have good optical and electrical properties. In this study, nickel oxide (NiO) is introduced into the DMD structure as a more appropriate dielectric material that has a high conduction band for electron blocking and a low valence band for efficient hole transport. The indium-free NiO/Ag/NiO (NAN) transparent electrode exhibits an adjustable high transmittance of ∼82% combined with a low sheet resistance of ∼7.6 Ω·s·q(-1) and a work function of 5.3 eV after UVO treatment. The NAN electrode shows excellent surface morphology and good thermal, humidity, and environmental stabilities. Only a small change in sheet resistance can be found after NAN electrode is preserved in air for 1 year. The power conversion efficiencies of organic photovoltaic cells with NAN electrodes deposited on glass and polyethylene terephthalate (PET) substrates are 6.07 and 5.55%, respectively, which are competitive with those of indium tin oxide (ITO)-based devices. Good photoelectric properties, the low-cost material, and the room-temperature deposition process imply that NAN electrode is a striking candidate for low-cost and flexible transparent electrode for efficient flexible optoelectronic devices.

Paper electrodes for bioelectrochemistry: Biosensors and biofuel cells.

Science.gov (United States)

Desmet, Cloé; Marquette, Christophe A; Blum, Loïc J; Doumèche, Bastien

2016-02-15

Paper-based analytical devices (PAD) emerge in the scientific community since 2007 as low-cost, wearable and disposable devices for point-of-care diagnostic due to the widespread availability, long-time knowledge and easy manufacturing of cellulose. Rapidly, electrodes were introduced in PAD for electrochemical measurements. Together with biological components, a new generation of electrochemical biosensors was born. This review aims to take an inventory of existing electrochemical paper-based biosensors and biofuel cells and to identify, at the light of newly acquired data, suitable methodologies and crucial parameters in this field. Paper selection, electrode material, hydrophobization of cellulose, dedicated electrochemical devices and electrode configuration in biosensors and biofuel cells will be discussed. Copyright © 2015 Elsevier B.V. All rights reserved.

Highly flexible indium zinc oxide electrode grown on PET substrate by cost efficient roll-to-roll sputtering process

International Nuclear Information System (INIS)

Park, Yong-Seok; Kim, Han-Ki; Jeong, Soon-Wook; Cho, Woon-Jo

2010-01-01

We have investigated the characteristics of flexible indium zinc oxide (IZO) electrode grown on polyethylene terephthalate (PET) substrates using a specially designed roll-to-roll (RTR) sputtering system for use in flexible optoelectronics. It was found that both electrical and optical properties of the flexible IZO electrode were critically dependent on the DC power and Ar/O 2 flow ratio during the roll-to-roll sputtering process. At optimized conditions (constant working pressure of 3 mTorr, Ar/O 2 flow ratio of Ar at only 30 sccm, DC power 800 W and rolling speed at 0.1 cm/s) the flexible IZO electrode exhibits a sheet resistance of 17.25 Ω/sq and an optical transmittance of 89.45% at 550 nm wavelength. Due to the low PET substrate temperature, which is effectively maintained by cooling drum system, all IZO electrodes showed an amorphous structure regardless of the DC power and Ar/O 2 flow ratio. Furthermore, the IZO electrodes grown at optimized condition exhibited superior flexibility than the conventional amorphous ITO electrodes due to its stable amorphous structure. This indicates that the RTR sputter grown IZO electrode is a promising flexible electrode that can substitute for the conventional ITO electrode, due to its low resistance, high transparency, superior flexibility and fast preparation by the RTR process.

The Development of Nano-Composite Electrodes for Solid Oxide Electrolyzers

Energy Technology Data Exchange (ETDEWEB)

Gorte, Raymond J.; Vohs, John M.

2014-03-26

Solid oxide fuel cells (SOFC) and electrolyzers (SOE) offer an attractive means for converting between electrical and chemical energy. Because they operate at high temperatures and are usually based on electrolytes that are oxygen-ion conducting ceramics, such as yttria-stabilized zirconia (YSZ), they are equally capable of converting between CO and CO2 as between H2 and H2O. When operated in the SOFC mode, they are able to operate on hydrocarbon fuels so long as there are no materials within the anode that can catalyze carbon formation. Compared to other types of electrolyzers, SOE can exhibit the highest efficiencies because the theoretical Nernst potential is lower at high temperatures and because the electrode overpotentials in SOE tend to be much lower. Finally, pure H2 can be produced without an external electrical source by electrolysis of steam at one electrode and oxidation of any fuel at the other electrode through a process known as Natural-Gas Assisted Steam Electrolysis. This final report describes results from studies of novel electrodes for SOE and SOFC prepared by infiltration methods.

Rubber-based carbon electrode materials derived from dumped tires for efficient sodium-ion storage.

Science.gov (United States)

Wu, Zhen-Yue; Ma, Chao; Bai, Yu-Lin; Liu, Yu-Si; Wang, Shi-Feng; Wei, Xiao; Wang, Kai-Xue; Chen, Jie-Sheng

2018-04-03

The development of sustainable and low cost electrode materials for sodium-ion batteries has attracted considerable attention. In this work, a carbon composite material decorated with in situ generated ZnS nanoparticles has been prepared via a simple pyrolysis of the rubber powder from dumped tires. Upon being used as an anode material for sodium-ion batteries, the carbon composite shows a high reversible capacity and rate capability. A capacity as high as 267 mA h g-1 is still retained after 100 cycles at a current density of 50 mA g-1. The well dispersed ZnS nanoparticles in carbon significantly enhance the electrochemical performance. The carbon composites derived from the rubber powder are proposed as promising electrode materials for low-cost, large-scale energy storage devices. This work provides a new and effective method for the reuse of dumped tires, contributing to the recycling of valuable waste resources.

Development of a pH sensing membrane electrode based on a new calix[4]arene derivative.

Science.gov (United States)

Kormalı Ertürün, H Elif; Demirel Özel, Ayça; Sayın, Serkan; Yılmaz, Mustafa; Kılıç, Esma

2015-01-01

A new pH sensing poly(vinyl chloride) (PVC) membrane electrode was developed by using recently synthesized 5,17-bis(4-benzylpiperidine-1-yl)methyl-25,26,27,28-tetrahydroxy calix[4]arene as an ionophore. The effects of membrane composition, inner filling solution and conditioning solution on the potential response of the proposed pH sensing membrane electrode were investigated. An optimum membrane composition of 3% ionophore, 67% o-nitrophenyl octyl ether (o-NPOE) as plasticizer, 30% PVC was found. The electrode exhibited a near-Nernstian slope of 58.7±1.1 mV pH(-1) in the pH range 1.9-12.7 at 20±1 °C. It showed good selectivity for H(+) ions in the presence of some cations and anions and a longer lifetime of at least 12 months when compared with the other PVC membrane pH electrodes reported in the literature. Having a wide working pH range, it was not only applied as a potentiometric indicator electrode in various acid-base titrations, but also successfully employed in different real samples. It has good reproducibility and repeatability with a response time of 6-7s. Compared to traditional glass pH electrode, it exhibited excellent potentiometric response after being used in fluoride-containing media. Copyright © 2014 Elsevier B.V. All rights reserved.

Enhancing the Supercapacitor Performance of Graphene/MnO 2 Nanostructured Electrodes by Conductive Wrapping

KAUST Repository

Yu, Guihua

2011-10-12

MnO2 is considered one of the most promising pseudocapactive materials for high-performance supercapacitors given its high theoretical specific capacitance, low-cost, environmental benignity, and natural abundance. However, MnO2 electrodes often suffer from poor electronic and ionic conductivities, resulting in their limited performance in power density and cycling. Here we developed a "conductive wrapping" method to greatly improve the supercapacitor performance of graphene/MnO2-based nanostructured electrodes. By three-dimensional (3D) conductive wrapping of graphene/MnO2 nanostructures with carbon nanotubes or conducting polymer, specific capacitance of the electrodes (considering total mass of active materials) has substantially increased by ∼20% and ∼45%, respectively, with values as high as ∼380 F/g achieved. Moreover, these ternary composite electrodes have also exhibited excellent cycling performance with >95% capacitance retention over 3000 cycles. This 3D conductive wrapping approach represents an exciting direction for enhancing the device performance of metal oxide-based electrochemical supercapacitors and can be generalized for designing next-generation high-performance energy storage devices. © 2011 American Chemical Society.

Inkjet printing of nanoporous gold electrode arrays on cellulose membranes for high-sensitive paper-like electrochemical oxygen sensors using ionic liquid electrolytes.

Science.gov (United States)

Hu, Chengguo; Bai, Xiaoyun; Wang, Yingkai; Jin, Wei; Zhang, Xuan; Hu, Shengshui

2012-04-17

A simple approach to the mass production of nanoporous gold electrode arrays on cellulose membranes for electrochemical sensing of oxygen using ionic liquid (IL) electrolytes was established. The approach, combining the inkjet printing of gold nanoparticle (GNP) patterns with the self-catalytic growth of these patterns into conducting layers, can fabricate hundreds of self-designed gold arrays on cellulose membranes within several hours using an inexpensive inkjet printer. The resulting paper-based gold electrode arrays (PGEAs) had several unique properties as thin-film sensor platforms, including good conductivity, excellent flexibility, high integration, and low cost. The porous nature of PGEAs also allowed the addition of electrolytes from the back cellulose membrane side and controllably produced large three-phase electrolyte/electrode/gas interfaces at the front electrode side. A novel paper-based solid-state electrochemical oxygen (O(2)) sensor was therefore developed using an IL electrolyte, 1-butyl-3-methylimidazolium hexafluorophosphate (BMIMPF(6)). The sensor looked like a piece of paper but possessed high sensitivity for O(2) in a linear range from 0.054 to 0.177 v/v %, along with a low detection limit of 0.0075% and a short response time of less than 10 s, foreseeing its promising applications in developing cost-effective and environment-friendly paper-based electrochemical gas sensors.

Screen-Printed Graphite Electrodes as Low-Cost Devices for Oxygen Gas Detection in Room-Temperature Ionic Liquids.

Science.gov (United States)

Lee, Junqiao; Hussain, Ghulam; Banks, Craig E; Silvester, Debbie S

2017-11-26

Screen-printed graphite electrodes (SPGEs) have been used for the first time as platforms to detect oxygen gas in room-temperature ionic liquids (RTILs). Up until now, carbon-based SPEs have shown inferior behaviour compared to platinum and gold SPEs for gas sensing with RTIL solvents. The electrochemical reduction of oxygen (O₂) in a range of RTILs has therefore been explored on home-made SPGEs, and is compared to the behaviour on commercially-available carbon SPEs (C-SPEs). Six common RTILs are initially employed for O₂ detection using cyclic voltammetry (CV), and two RTILs ([C₂mim][NTf₂] and [C₄mim][PF₆]) chosen for further detailed analytical studies. Long-term chronoamperometry (LTCA) was also performed to test the ability of the sensor surface for real-time gas monitoring. Both CV and LTCA gave linear calibration graphs-for CV in the 10-100% vol. range, and for LTCA in the 0.1-20% vol. range-on the SPGE. The responses on the SPGE were far superior to the commercial C-SPEs; more instability in the electrochemical responses were observed on the C-SPEs, together with some breaking-up or dissolution of the electrode surface materials. This study highlights that not all screen-printed ink formulations are compatible with RTIL solvents for longer-term electrochemical experiments, and that the choice of RTIL is also important. Overall, the low-cost SPGEs appear to be promising platforms for the detection of O₂, particularly in [C₄mim][PF₆].

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.

Electrochemical characterization of LiCoO2 as rechargeable electrode in aqueous LiNO3 electrolyte

KAUST Repository

Ruffo, Riccardo

2011-06-01

The development of lithium ion aqueous batteries is getting renewed interest due to their safety and low cost. We have demonstrated that the layer-structure LiCoO2 phase, the most commonly used electrode material in organic systems, can be successful delithiated and lithiated again in a water-based electrolyte at currents up to 2.70 A/g. The capacity is about 100 mAh/g at 0.135 A/g and can be tuned by cycling the electrode in different potential ranges. In fact, increasing the high cut-off voltage leads to higher specific capacity (up to 135 mAh/g) but the Coulomb efficiency is reduced (from 99.9% to 98.5%). The very good electrode kinetic is probably due to the high conductivity of the electrolyte solution (0.17 Scm- 1 at 25 °C) but this behavior is affected by the electrode load. © 2010 Elsevier B.V. All rights reserved.

Removal of suspended solids and turbidity from marble processing wastewaters by electrocoagulation: Comparison of electrode materials and electrode connection systems

Energy Technology Data Exchange (ETDEWEB)

Solak, Murat [Duezce University, Kaynasli Vocational School, Environmental Protection and Control Department, 81900 Duezce (Turkey); Kilic, Mehmet, E-mail: kavi@mmf.sdu.edu.tr [Sueleyman Demirel University, Engineering and Architecture Faculty, Environmental Engineering Department, 32260 Isparta (Turkey); Hueseyin, Yazici; Sencan, Aziz [Sueleyman Demirel University, Engineering and Architecture Faculty, Environmental Engineering Department, 32260 Isparta (Turkey)

2009-12-15

In this study, removal of suspended solids (SS) and turbidity from marble processing wastewaters by electrocoagulation (EC) process were investigated by using aluminium (Al) and iron (Fe) electrodes which were run in serial and parallel connection systems. To remove these pollutants from the marble processing wastewater, an EC reactor including monopolar electrodes (Al/Fe) in parallel and serial connection system, was utilized. Optimization of differential operation parameters such as pH, current density, and electrolysis time on SS and turbidity removal were determined in this way. EC process with monopolar Al electrodes in parallel and serial connections carried out at the optimum conditions where the pH value was 9, current density was approximately 15 A/m{sup 2}, and electrolysis time was 2 min resulted in 100% SS removal. Removal efficiencies of EC process for SS with monopolar Fe electrodes in parallel and serial connection were found to be 99.86% and 99.94%, respectively. Optimum parameters for monopolar Fe electrodes in both of the connection types were found to be for pH value as 8, for electrolysis time as 2 min. The optimum current density value for Fe electrodes used in serial and parallel connections was also obtained at 10 and 20 A/m{sup 2}, respectively. Based on the results obtained, it was found that EC process running with each type of the electrodes and the connections was highly effective for the removal of SS and turbidity from marble processing wastewaters, and that operating costs with monopolar Al electrodes in parallel connection were the cheapest than that of the serial connection and all the configurations for Fe electrode.

Removal of suspended solids and turbidity from marble processing wastewaters by electrocoagulation: Comparison of electrode materials and electrode connection systems

International Nuclear Information System (INIS)

Solak, Murat; Kilic, Mehmet; Hueseyin, Yazici; Sencan, Aziz

2009-01-01

In this study, removal of suspended solids (SS) and turbidity from marble processing wastewaters by electrocoagulation (EC) process were investigated by using aluminium (Al) and iron (Fe) electrodes which were run in serial and parallel connection systems. To remove these pollutants from the marble processing wastewater, an EC reactor including monopolar electrodes (Al/Fe) in parallel and serial connection system, was utilized. Optimization of differential operation parameters such as pH, current density, and electrolysis time on SS and turbidity removal were determined in this way. EC process with monopolar Al electrodes in parallel and serial connections carried out at the optimum conditions where the pH value was 9, current density was approximately 15 A/m 2 , and electrolysis time was 2 min resulted in 100% SS removal. Removal efficiencies of EC process for SS with monopolar Fe electrodes in parallel and serial connection were found to be 99.86% and 99.94%, respectively. Optimum parameters for monopolar Fe electrodes in both of the connection types were found to be for pH value as 8, for electrolysis time as 2 min. The optimum current density value for Fe electrodes used in serial and parallel connections was also obtained at 10 and 20 A/m 2 , respectively. Based on the results obtained, it was found that EC process running with each type of the electrodes and the connections was highly effective for the removal of SS and turbidity from marble processing wastewaters, and that operating costs with monopolar Al electrodes in parallel connection were the cheapest than that of the serial connection and all the configurations for Fe electrode.

Removal of suspended solids and turbidity from marble processing wastewaters by electrocoagulation: comparison of electrode materials and electrode connection systems.

Science.gov (United States)

Solak, Murat; Kiliç, Mehmet; Hüseyin, Yazici; Sencan, Aziz

2009-12-15

In this study, removal of suspended solids (SS) and turbidity from marble processing wastewaters by electrocoagulation (EC) process were investigated by using aluminium (Al) and iron (Fe) electrodes which were run in serial and parallel connection systems. To remove these pollutants from the marble processing wastewater, an EC reactor including monopolar electrodes (Al/Fe) in parallel and serial connection system, was utilized. Optimization of differential operation parameters such as pH, current density, and electrolysis time on SS and turbidity removal were determined in this way. EC process with monopolar Al electrodes in parallel and serial connections carried out at the optimum conditions where the pH value was 9, current density was approximately 15 A/m(2), and electrolysis time was 2 min resulted in 100% SS removal. Removal efficiencies of EC process for SS with monopolar Fe electrodes in parallel and serial connection were found to be 99.86% and 99.94%, respectively. Optimum parameters for monopolar Fe electrodes in both of the connection types were found to be for pH value as 8, for electrolysis time as 2 min. The optimum current density value for Fe electrodes used in serial and parallel connections was also obtained at 10 and 20 A/m(2), respectively. Based on the results obtained, it was found that EC process running with each type of the electrodes and the connections was highly effective for the removal of SS and turbidity from marble processing wastewaters, and that operating costs with monopolar Al electrodes in parallel connection were the cheapest than that of the serial connection and all the configurations for Fe electrode.

Disposable screen printed graphite electrode for the direct electrochemical determination of ibuprofen in surface water

KAUST Repository

Amin, Sidra; Soomro, M. Tahir; Memon, Najma; Solangi, Amber R.; Sirajuddin; Qureshi, Tahira; Behzad, Ali Reza

2014-01-01

The potential of square wave voltammetry (SWV) for the determination of ibuprofen in aqueous solution, applying baseline correction, is reported. A screen printed graphite electrodes (SPGEs), especially pretreated for this purpose, were used to investigate the electrochemical oxidation and detection of ibuprofen. After optimization of SWV parameters, measurements were carried out at 200 Hz modulation frequency, 4 mV step potential and 40 mV pulse amplitude for the determination of ibuprofen. The surfaces of both untreated and pretreated SPGEs were characterized by scanning electron microscopy (SEM) and electrochemical impedance spectroscopy (EIS). The electro-catalytic properties of both the electrodes were correlated with the surface treatment. The pretreated screen printed graphite electrode exhibited a high sensitivity toward ibuprofen even in low concentration. The developed method was found rapid, cost-effective and reproducible for in-field ibuprofen detection.

Disposable screen printed graphite electrode for the direct electrochemical determination of ibuprofen in surface water

KAUST Repository

Amin, Sidra

2014-08-01

The potential of square wave voltammetry (SWV) for the determination of ibuprofen in aqueous solution, applying baseline correction, is reported. A screen printed graphite electrodes (SPGEs), especially pretreated for this purpose, were used to investigate the electrochemical oxidation and detection of ibuprofen. After optimization of SWV parameters, measurements were carried out at 200 Hz modulation frequency, 4 mV step potential and 40 mV pulse amplitude for the determination of ibuprofen. The surfaces of both untreated and pretreated SPGEs were characterized by scanning electron microscopy (SEM) and electrochemical impedance spectroscopy (EIS). The electro-catalytic properties of both the electrodes were correlated with the surface treatment. The pretreated screen printed graphite electrode exhibited a high sensitivity toward ibuprofen even in low concentration. The developed method was found rapid, cost-effective and reproducible for in-field ibuprofen detection.

Oil and gas pipeline construction cost analysis and developing regression models for cost estimation

Science.gov (United States)

Thaduri, Ravi Kiran

In this study, cost data for 180 pipelines and 136 compressor stations have been analyzed. On the basis of the distribution analysis, regression models have been developed. Material, Labor, ROW and miscellaneous costs make up the total cost of a pipeline construction. The pipelines are analyzed based on different pipeline lengths, diameter, location, pipeline volume and year of completion. In a pipeline construction, labor costs dominate the total costs with a share of about 40%. Multiple non-linear regression models are developed to estimate the component costs of pipelines for various cross-sectional areas, lengths and locations. The Compressor stations are analyzed based on the capacity, year of completion and location. Unlike the pipeline costs, material costs dominate the total costs in the construction of compressor station, with an average share of about 50.6%. Land costs have very little influence on the total costs. Similar regression models are developed to estimate the component costs of compressor station for various capacities and locations.

Development of liquid film thickness measurement technique by high-density multipoint electrodes method

International Nuclear Information System (INIS)

Arai, Takahiro; Furuya, Masahiro; Kanai, Taizo

2010-01-01

High-density multipoint electrode method was developed to measure a liquid film thickness transient on a curved surface. The devised method allows us to measure spatial distribution of liquid film with its conductance between electrodes. The sensor was designed and fabricated as a multilayer print circuit board, where electrode pairs were distributed in reticular pattern with narrow interval. In order to measure a lot of electrode pairs at a high sampling rate, signal-processing method used by the wire mesh sensor measurement system was applied. An electrochemical impedance spectrometry concludes that the sampling rate of 1000 slices/s is feasible without signal distortion by electric double layer. The method was validated with two experimental campaigns: (1) a droplet impingement on a flat film and (2) a jet impingement on a rod-shape sensor surface. In the former experiment, a water droplet having 4 mm in diameter impinged onto the 1 mm thick film layer. A visual observation study with high-speed video camera shows after the liquid impingement, the water layer thinning process was clearly demonstrated with the sensor. For the latter experiment, the flexible circuit board was bended to form a cylindrical shape to measure water film on a simulated fuel rod in bundle geometry. A water jet having 3 mm in diameter impinged onto the rod-shape sensor surface. The process of wetting area enlargement on the rod surface was demonstrated in the same manner that the video-frames showed. (author)

Removal of arsenic from drinking water by the electrocoagulation using Fe and Al electrodes

International Nuclear Information System (INIS)

Kobya, M.; Gebologlu, U.; Ulu, F.; Oncel, S.; Demirbas, E.

2011-01-01

Highlights: → Removal percentages of arsenic from drinking water at optimum operating conditions in electrocoagulation process were 93.5% for Fe electrode and 95.7% for Al electrode. → Operating costs at the optimum conditions were 0.020 Euro m -3 for Fe and 0.017 Euro m -3 for Al electrodes. → Surface topography of the solid particles at Fe/Al electrodes was analyzed with scanning electron microscope. → The adsorption of arsenic followed pseudo second-order adsorption model. - Abstract: A novel technique of electrocoagulation (EC) was attempted in the present investigation to remove arsenic from drinking waters. Experiments were carried out in a batch electrochemical reactor using Al and Fe electrodes with monopolar parallel electrode connection mode to assess their efficiency. The effects of several operating parameters on arsenic removal such as pH (4-9), current density (2.5-7.5 A m -2 ), initial concentration (75-500 μg L -1 ) and operating time (0-15 min) were examined. Optimum operating conditions were determined as an operating time of 12.5 min and pH 6.5 for Fe electrode (93.5%) and 15 min and pH 7 for Al electrode (95.7%) at 2.5 A m -2 , respectively. Arsenic removal obtained was highest with Al electrodes. Operating costs at the optimum conditions were calculated as 0.020 Euro m -3 for Fe and 0.017 Euro m -3 for Al electrodes. EC was able to bring down aqueous phase arsenic concentration to less than 10 μg L -1 with Fe and Al electrodes. The adsorption of arsenic over electrochemically produced hydroxides and metal oxide complexes was found to follow pseudo second-order adsorption model. Scanning electron microscopy was also used to analyze surface topography of the solid particles at Fe/Al electrodes during the EC process.

Removal of arsenic from drinking water by the electrocoagulation using Fe and Al electrodes

Energy Technology Data Exchange (ETDEWEB)

Kobya, M., E-mail: kobya@gyte.edu.tr [Gebze Institute of Technology, Department of Environmental Engineering, 41400 Gebze (Turkey); Gebologlu, U.; Ulu, F.; Oncel, S. [Gebze Institute of Technology, Department of Environmental Engineering, 41400 Gebze (Turkey); Demirbas, E. [Gebze Institute of Technology, Department of Chemistry, 41400 Gebze (Turkey)

2011-05-30

Highlights: > Removal percentages of arsenic from drinking water at optimum operating conditions in electrocoagulation process were 93.5% for Fe electrode and 95.7% for Al electrode. > Operating costs at the optimum conditions were 0.020 Euro m{sup -3} for Fe and 0.017 Euro m{sup -3} for Al electrodes. > Surface topography of the solid particles at Fe/Al electrodes was analyzed with scanning electron microscope. > The adsorption of arsenic followed pseudo second-order adsorption model. - Abstract: A novel technique of electrocoagulation (EC) was attempted in the present investigation to remove arsenic from drinking waters. Experiments were carried out in a batch electrochemical reactor using Al and Fe electrodes with monopolar parallel electrode connection mode to assess their efficiency. The effects of several operating parameters on arsenic removal such as pH (4-9), current density (2.5-7.5 A m{sup -2}), initial concentration (75-500 {mu}g L{sup -1}) and operating time (0-15 min) were examined. Optimum operating conditions were determined as an operating time of 12.5 min and pH 6.5 for Fe electrode (93.5%) and 15 min and pH 7 for Al electrode (95.7%) at 2.5 A m{sup -2}, respectively. Arsenic removal obtained was highest with Al electrodes. Operating costs at the optimum conditions were calculated as 0.020 Euro m{sup -3} for Fe and 0.017 Euro m{sup -3} for Al electrodes. EC was able to bring down aqueous phase arsenic concentration to less than 10 {mu}g L{sup -1} with Fe and Al electrodes. The adsorption of arsenic over electrochemically produced hydroxides and metal oxide complexes was found to follow pseudo second-order adsorption model. Scanning electron microscopy was also used to analyze surface topography of the solid particles at Fe/Al electrodes during the EC process.

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

Development cost capitalization during R&D races

NARCIS (Netherlands)

Waegenaere, Anja M.B.; Sansing, R.C.; Wielhouwer, J.L.

We investigate the economic effects of capitalizing development costs during a race between two firms to discover and develop a new technology. Winning the race requires success in the research stage and success in the development stage. Development costs are expensed in some settings, but

Development Cost Capitalization During R&D Races

NARCIS (Netherlands)

De Waegenaere, A.; Sansing, R.C.; Wielhouwer, J.L.

2017-01-01

We investigate the economic effects of capitalizing development costs during a race between two firms to discover and develop a new technology. Winning the race requires success in the research stage and success in the development stage. Development costs are expensed in some settings, but

Highly selective direct determination of chlorate ions by using a newly developed potentiometric electrode based on modified smectite.

Science.gov (United States)

Topcu, Cihan

2016-12-01

A novel polyvinyl chloride membrane chlorate (ClO 3 - ) selective electrode based on modified smectite was developed for the direct determination of chlorate ions and the potentiometric performance characteristics of its were examined. The best selectivity and sensitivity for chlorate ions were obtained for the electrode membrane containing ionophore/polyvinylchloride/o-nitrophenyloctylether in composition of 12/28/60 (w/w%). The proposed electrode showed a Nernstian response toward chlorate ions at pH=7 in the concentration range of 1×10 -7 -1×10 -1 M and the limit of detection was calculated as 9×10 -8 M from the constructed response plot. The linear slope of the electrode was -61±1mVdecade -1 for chlorate activity in the mentioned linear working range. The selectivity coefficients were calculated according to both the matched potential method and the separate solution method. The calculated selectivity coefficients showed that the electrode performed excellent selectivity for chlorate ions. The potentiometric response of electrode toward chlorate ions was found to be highly reproducible. The electrode potential was stable between pH=4-10 and it had a dynamic response time of <5s. The potentiometric behavior of the electrode in partial non-aqueous medium was also investigated and the obtained results (up to 5% (v/v) alcohol) were satisfactory. The proposed electrode was used during 15 weeks without any significant change in its potential response. Additionally, the electrode was very useful in water analysis studies such as dam water, river water, tap water, and swimming pool water where the direct determination of chlorate ions was required. Copyright © 2016 Elsevier B.V. All rights reserved.

Method for intercalating alkali metal ions into carbon electrodes

Science.gov (United States)

Doeff, Marca M.; Ma, Yanping; Visco, Steven J.; DeJonghe, Lutgard

1995-01-01

A low cost, relatively flexible, carbon electrode for use in a secondary battery is described. A method is provided for producing same, including intercalating alkali metal salts such as sodium and lithium into carbon.

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.

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

Development of carbon paste electrodes modified by molecularly imprinted polymer as potentiometry sensor of uric acid

Science.gov (United States)

Khasanah, Miratul; Darmokoesoemo, Handoko; Widayanti, Nesti; Kadmi, Yassine; Elmsellem, Hicham; Kusuma, Heri Septya

The development of carbon paste electrodes modified by molecularly imprinted polymer (MIP) for the potentiometric analysis of uric acid was carried out in this study. The aim of the study was to determine the optimum composition of the electrode constituent material, the optimum pH of the uric acid solution, and the performance of the electrode, which was measured by its response time, measurement range, Nernst factor, detection limits, selectivity coefficient, precision, accuracy, and life time. MIP was made from methyl methacrylate as the monomer, ethylene glycol dimethacrylate as the cross-linker, and uric acid as the template. Electrodes that give optimum performance were produced from carbon, MIP, and paraffin with a ratio of 40:25:35 (% w/w). The obtained results show that the measurement of uric acid solution gives optimum results at pH 5, Nernst factor of 30.19 mV/decade, and a measurement range of 10-6-10-3 M. The minimum detection limit of this method was 3.03.10-6 M, and the precision and accuracy toward uric acid with concentration of 10-6-10-3 M ranged between 1.36-2.03% and 63.9-166%. The selectivity coefficient value was less than 1, which indicated that the electrode was selective against uric acid and not interfered with by urea. This electrode has a response time of less than 2 min; its life time is 8 weeks with 104 usage times.

Developing electrodes chemically modified with cucurbit[6]uril to detect 3,4-methylenedioxymethamphetamine (MDMA) by voltammetry

International Nuclear Information System (INIS)

Tadini, Maraine Catarina; Balbino, Marco Antonio; Eleoterio, Izabel Cristina; Siqueirade Oliveira, Laura; Dias, Luis Gustavo; Jean-François Demets, Grégoire; Firmino de Oliveira, Marcelo

2014-01-01

Graphical abstract: - Highlights: • A new stand in forensic chemistry. • Voltammetric method for the determination of MDMA in seized samples. • A new voltammetric sensor for MDMA. - Abstract: This study aimed to develop an electrode chemically modified with cucurbit[6]uril to detect 3,4-methylenedioxymethamphetamine (MDMA), the main active principle of ecstasy samples, by voltammetry. We modified the electrode surface with a film containing cucurbit[6]uril, Nafion, and methanol, using the dip coating or the spin coating technique. During analysis, we employed an electrochemical cell with a conventional three-electrode system and KCl solution (0.1 mol L −1 ) as the supporting electrolyte. We conducted cyclic voltammetry at concentrations ranging from 4.2 × 10 −6 to 4.8 × 10 −5 mol L −1 . We also accomplished scanning electron microscopy, to investigate the structural behavior of the film that originated on the electrode surface. We obtained the following results when we used dip coating to prepare the modified electrode: standard deviation (SD) = 0.024 μA, limit of detection (LOD) = 3.5 μmol L −1 , limit of quantification (LOQ) = 11.7 μmol L −1 , and amperometric sensitivity (m) = 20.9 × 10 3 μA L mol −1 . As for spin coating, we obtained SD = 0.024 μA, LOD = 2.7 μmol L −1 , LOQ = 9.1 μmol L −1 and m = 25.9 × 10 3 μA mol L −1 . These are very promising data: the modified electrode is more sensitive than the conventional glassy carbon electrode under the studied experimental conditions

Development of a low-cost oxy-hydrogen bio-fuel cell for generation of electricity using Nostoc as a source of hydrogen

Energy Technology Data Exchange (ETDEWEB)

Sangeeta Dawar; Behera, B.K. [Maharshi Dayanand University, Rohtak (India). Dept. of Biosciences; Prasanna Mohanty [Jawaharlal Nehru University, New Delhi (India). School of Life Sciences

1998-10-10

An oxy-hydrogen bio-fuel cell, based on a carbon-carbon electrode has been fabricated. The electrode pellets were prepared by taking carbon powder mixed with polyvinylalcohol as a binder. The anode was charged with Co-Al spinel mixed oxide at 700{sup o}C, 30% KOH acted as an electrolyte. For the cyanobacterial bioreactor, a potential heterocystous blue green alga of Nostoc spp. has been used for hydrogen production and electrical energy generation. Various nutrient enrichment techniques are employed to increase the hydrogen generation efficiency of the algae. One litre free cell algal reactor attached to the fuel cell, at the anode end for hydrogen gas input, generated about 300 mV of voltage and 100 mA of current. Our present findings on the development of a low cost fuel cell with high efficiency of current output may be helpful in commercializing this technology. (author)

Research Progress in MnO2 -Carbon Based Supercapacitor Electrode Materials.

Science.gov (United States)

Zhang, Qun-Zheng; Zhang, Dian; Miao, Zong-Cheng; Zhang, Xun-Li; Chou, Shu-Lei

2018-04-30

With the serious impact of fossil fuels on the environment and the rapid development of the global economy, the development of clean and usable energy storage devices has become one of the most important themes of sustainable development in the world today. Supercapacitors are a new type of green energy storage device, with high power density, long cycle life, wide temperature range, and both economic and environmental advantages. In many industries, they have enormous application prospects. Electrode materials are an important factor affecting the performance of supercapacitors. MnO 2 -based materials are widely investigated for supercapacitors because of their high theoretical capacitance, good chemical stability, low cost, and environmental friendliness. To achieve high specific capacitance and high rate capability, the current best solution is to use MnO 2 and carbon composite materials. Herein, MnO 2 -carbon composite as supercapacitor electrode materials is reviewed including the synthesis method and research status in recent years. Finally, the challenges and future development directions of an MnO 2 -carbon based supercapacitor are summarized. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Aligned nanowire growth using lithography-assisted bonding of a polycarbonate template for neural probe electrodes

International Nuclear Information System (INIS)

Yoon, Hargsoon; Deshpande, Devesh C; Ramachandran, Vasuda; Varadan, Vijay K

2008-01-01

This research presents a fabrication method of vertically aligned nanowires on substrates using lithography-assisted template bonding (LATB) towards developing highly efficient electrodes for biomedical applications at low cost. A polycarbonate template containing cylindrical nanopores is attached to a substrate and the nanopores are selectively opened with a modified lithography process. Vertically aligned nanowires are grown by electrochemical deposition through these open pores on polyimide film and silicon substrates. The process of opening the nanopores is optimized to yield uniform growth of nanowires. The morphological, crystalline, and electrochemical properties of the resulting vertically aligned nanowires are discussed using scanning electron microscopy (SEM), x-ray diffraction (XRD), and electrochemical analysis tools. The potential application of this simple and inexpensive fabrication technology is discussed in the development of neural probe electrodes

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.

Low cost UV-Ozone reactor mounted for treatment of electrode anodes used in P-OLEDs devices

Directory of Open Access Journals (Sweden)

Emerson Roberto Santos

Full Text Available Abstract Low cost UV-Ozone reactor using a high pressure mercury vapor lamp of 80 watts without outer bulb showed good results for treatment of ITO films used as anode electrode in the assembly of P-OLED (polymer-organic light emitting diode devices. This study revealed 20 minutes as effective treatment time and it was verified also that the effect of UV-Ozone treatment loses its efficiency as the elapsed time increases. It was analyzed with measurements of contact angle using a droplet of PEDOT:PSS polymer. P-OLEDs devices were mounted with architecture: ITO/PEDOT:PSS/PVK/Alq3/Al. The PVK polymer was diluted in organic solvent of 1,2,4-trichlorobenzene with concentrations of: 5, 10, 20 and 30 mg/mL. Results revealed better performance of P-OLED devices for concentration of 5 mg/mL resulting in lower threshold voltage, elevation of electrical current and similar diode curve.

Critical Research for Cost-Effective Photoelectrochemical Production of Hydrogen

Energy Technology Data Exchange (ETDEWEB)

Xu, Liwei [Midwest Optoelectronics, LLC, Toledo, OH (United States); Deng, Xunming [Univ. of Toledo, OH (United States); Abken, Anka [Midwest Optoelectronics, LLC, Toledo, OH (United States); Cao, Xinmin [Midwest Optoelectronics, LLC, Toledo, OH (United States); Du, Wenhui [Midwest Optoelectronics, LLC, Toledo, OH (United States); Vijh, Aarohi [Xunlight Corporation, Toledo, OH (United States); Ingler, William [Univ. of Toledo, OH (United States); Chen, Changyong [Univ. of Toledo, OH (United States); Fan, Qihua [Univ. of Toledo, OH (United States); Collins, Robert [Univ. of Toledo, OH (United States); Compaan, Alvin [Univ. of Toledo, OH (United States); Yan, Yanfa [Univ. of Toledo, OH (United States); Giolando, Dean [Univ. of Toledo, OH (United States); Turner, John [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2014-10-29

The objective of this project is to develop critical technologies required for cost-effective production of hydrogen from sunlight and water using a-Si triple junction solar cell based photo-electrodes. In this project, Midwest Optoelectronics, LLC (MWOE) and its collaborating organizations utilize triple junction a-Si thin film solar cells as the core element to fabricate photoelectrochemical (PEC) cells. Triple junction a-Si/a-SiGe/a-SiGe solar cell is an ideal material for making cost-effective PEC system which uses sun light to split water and generate hydrogen. It has the following key features: 1) It has an open circuit voltage (Voc ) of ~ 2.3V and has an operating voltage around 1.6V. This is ideal for water splitting. There is no need to add a bias voltage or to inter-connect more than one solar cell. 2) It is made by depositing a-Si/a-SiGe/aSi-Ge thin films on a conducting stainless steel substrate which can serve as an electrode. When we immerse the triple junction solar cells in an electrolyte and illuminate it under sunlight, the voltage is large enough to split the water, generating oxygen at the Si solar cell side (for SS/n-i-p/sunlight structure) and hydrogen at the back, which is stainless steel side. There is no need to use a counter electrode or to make any wire connection. 3) It is being produced in large rolls of 3ft wide and up to 5000 ft long stainless steel web in a 25MW roll-to-roll production machine. Therefore it can be produced at a very low cost. After several years of research with many different kinds of material, we have developed promising transparent, conducting and corrosion resistant (TCCR) coating material; we carried out extensive research on oxygen and hydrogen generation catalysts, developed methods to make PEC electrode from production-grade a-Si solar cells; we have designed and tested various PEC module cases and carried out extensive outdoor testing; we were able to obtain a solar to hydrogen conversion efficiency (STH

Solid-state, polymer-based fiber solar cells with carbon nanotube electrodes.

Science.gov (United States)

Liu, Dianyi; Zhao, Mingyan; Li, Yan; Bian, Zuqiang; Zhang, Luhui; Shang, Yuanyuan; Xia, Xinyuan; Zhang, Sen; Yun, Daqin; Liu, Zhiwei; Cao, Anyuan; Huang, Chunhui

2012-12-21

Most previous fiber-shaped solar cells were based on photoelectrochemical systems involving liquid electrolytes, which had issues such as device encapsulation and stability. Here, we deposited classical semiconducting polymer-based bulk heterojunction layers onto stainless steel wires to form primary electrodes and adopted carbon nanotube thin films or densified yarns to replace conventional metal counter electrodes. The polymer-based fiber cells with nanotube film or yarn electrodes showed power conversion efficiencies in the range 1.4% to 2.3%, with stable performance upon rotation and large-angle bending and during long-time storage without further encapsulation. Our fiber solar cells consisting of a polymeric active layer sandwiched between steel and carbon electrodes have potential in the manufacturing of low-cost, liquid-free, and flexible fiber-based photovoltaics.

Simple approach for the fabrication of screen-printed carbon-based electrode for amperometric detection on microchip electrophoresis

International Nuclear Information System (INIS)

Petroni, Jacqueline Marques; Lucca, Bruno Gabriel; Ferreira, Valdir Souza

2017-01-01

This paper describes a simple method for the fabrication of screen-printed based electrodes for amperometric detection on microchip electrophoresis (ME) devices. The procedure developed is quite simple and does not require expensive instrumentation or sophisticated protocols commonly employed on the production of amperometric sensors, such as photolithography or sputtering steps. The electrodes were fabricated through manual deposition of home-made conductive carbon ink over patterned acrylic substrate. Morphological structure and electrochemical behavior of the carbon electrodes were investigated by scanning electron microscopy and cyclic voltammetry. The produced amperometric sensors were coupled to polydimethylsiloxane (PDMS) microchips at end-channel configuration in order to evaluate their analytical performance. For this purpose, electrophoretic experiments were carried out using nitrite and ascorbic acid as model analytes. Separation of these substances was successfully performed within 50s with good resolution (R = 1.2) and sensitivities (713.5 pA/μM for nitrite and 255.4 pA/μM for ascorbate). The reproducibility of the fabrication method was evaluated and revealed good values concerning the peak currents obtained (8.7% for nitrite and 9.3% for ascorbate). The electrodes obtained through this method exhibited satisfactory lifetime (ca. 400 runs) over low fabrication cost (less than $1 per piece). The feasibility of the proposed device for real analysis was demonstrated through the determination of nitrite concentration levels in drinking water samples. Based on the results achieved, the approach proposed here shows itself as an interesting alternative for simple fabrication of carbon-based electrodes. Furthermore, the devices indicate great promise for other kind of analytical applications involving ME devices. - Highlights: • A novel method to fabricate screen-printed electrodes for amperometric detection in ME is demonstrated. • No sophisticated

Simple approach for the fabrication of screen-printed carbon-based electrode for amperometric detection on microchip electrophoresis

Energy Technology Data Exchange (ETDEWEB)

Petroni, Jacqueline Marques [Instituto de Química, Universidade Federal de Mato Grosso do Sul, Campo Grande, MS, 79074-460 (Brazil); Lucca, Bruno Gabriel, E-mail: bruno.lucca@ufes.br [Departamento de Ciências Naturais, Universidade Federal do Espírito Santo, São Mateus, ES, 29932-540 (Brazil); Ferreira, Valdir Souza [Instituto de Química, Universidade Federal de Mato Grosso do Sul, Campo Grande, MS, 79074-460 (Brazil)

2017-02-15

This paper describes a simple method for the fabrication of screen-printed based electrodes for amperometric detection on microchip electrophoresis (ME) devices. The procedure developed is quite simple and does not require expensive instrumentation or sophisticated protocols commonly employed on the production of amperometric sensors, such as photolithography or sputtering steps. The electrodes were fabricated through manual deposition of home-made conductive carbon ink over patterned acrylic substrate. Morphological structure and electrochemical behavior of the carbon electrodes were investigated by scanning electron microscopy and cyclic voltammetry. The produced amperometric sensors were coupled to polydimethylsiloxane (PDMS) microchips at end-channel configuration in order to evaluate their analytical performance. For this purpose, electrophoretic experiments were carried out using nitrite and ascorbic acid as model analytes. Separation of these substances was successfully performed within 50s with good resolution (R = 1.2) and sensitivities (713.5 pA/μM for nitrite and 255.4 pA/μM for ascorbate). The reproducibility of the fabrication method was evaluated and revealed good values concerning the peak currents obtained (8.7% for nitrite and 9.3% for ascorbate). The electrodes obtained through this method exhibited satisfactory lifetime (ca. 400 runs) over low fabrication cost (less than $1 per piece). The feasibility of the proposed device for real analysis was demonstrated through the determination of nitrite concentration levels in drinking water samples. Based on the results achieved, the approach proposed here shows itself as an interesting alternative for simple fabrication of carbon-based electrodes. Furthermore, the devices indicate great promise for other kind of analytical applications involving ME devices. - Highlights: • A novel method to fabricate screen-printed electrodes for amperometric detection in ME is demonstrated. • No sophisticated

Finding and development costs in the United States

International Nuclear Information System (INIS)

Espenshade, S.A.

1996-01-01

The finding and development costs, or reserve replacement costs have become important statistics for benchmarking independent oil and gas companies against one another. However, no standard definition for finding costs exists. Every company reports their costs differently because of different accounting practices. The time period a company uses to calculate its finding costs is also important. Since exploring for a field and developing new properties involves a long lead time, costs should be calculated on an annual basis. Reserve replacement costs should include: acquisition costs, developments costs, exploration costs, geological and geophysical costs, general and administrative costs, drilling costs and improved recovery costs. The importance of independent oil and gas companies was emphasized. They drill 85% of all the wells in the United States and produce 64% of the natural gas and 37% of the crude oil. In the lower 48 states alone, they produce 49% of the crude oil. Lightening of regulatory and legislative burdens, opening up access to more public lands, improving the tax situation, and to obtain royalty relief, were considered essential to providing for the energy needs of Americans in the years to come. 12 figs

Laser printed graphene on polyimide electrodes for magnetohydrodynamic pumping of saline fluids

KAUST Repository

Khan, Mohammed Asadullah; Hristovski, Ilija R.; Marinaro, Giovanni; Mohammed, Hanan; Kosel, Jü rgen

2017-01-01

An efficient, scalable pumping device is reported that avoids moving parts and is fabricated with a cost-effective method. The magnetohydrodynamic pump has electrodes facilely made by laser printing of polyimide. The electrodes exhibit a low sheet resistance of 22.75 Ω/square. The pump is implemented in a channel of 240 mm² cross-section and has an electrode length of 5 mm. When powered by 7.3 V and 12.43 mA/cm², it produces 13.02 mm/s flow velocity.

Laser printed graphene on polyimide electrodes for magnetohydrodynamic pumping of saline fluids

KAUST Repository

Khan, Mohammed Asadullah

2017-08-09

An efficient, scalable pumping device is reported that avoids moving parts and is fabricated with a cost-effective method. The magnetohydrodynamic pump has electrodes facilely made by laser printing of polyimide. The electrodes exhibit a low sheet resistance of 22.75 Ω/square. The pump is implemented in a channel of 240 mm² cross-section and has an electrode length of 5 mm. When powered by 7.3 V and 12.43 mA/cm², it produces 13.02 mm/s flow velocity.

Carbon Black-Modified Electrodes Screen-Printed onto Paper Towel, Waxed Paper and Parafilm M®.

Science.gov (United States)

Cinti, Stefano; Mazzaracchio, Vincenzo; Cacciotti, Ilaria; Moscone, Danila; Arduini, Fabiana

2017-10-03

Herein, we evaluated the use of paper towel, waxed paper, and Parafilm M ® (Heathrow Scientific, Vernon Hills, IL, USA) as alternative substrates for screen-printed sensor manufacturing. Morphological study was performed to evaluate the adhesion of the ink on these uncommon substrates, as well as the morphology of the working electrode. The electrochemical characterization was carried out using ferricyanide/ferrocyanide as redox couple. To enhance the electrochemical properties of the developed sensors, the nanomaterial carbon black was used as nanomodifier. The modification by drop casting of the working electrode surface, using a stable dispersion of carbon black, allows to obtain a sensor with improved electrochemical behavior in terms of peak-to-peak separation, current intensity, and the resistance of charge transfer. The results achieved confirm the possibility of printing the electrode on several cost-effective paper-based materials and the improvement of the electrochemical behavior by using carbon black as sustainable nanomaterial.

Carbon Black-Modified Electrodes Screen-Printed onto Paper Towel, Waxed Paper and Parafilm M®

Directory of Open Access Journals (Sweden)

Stefano Cinti

2017-10-01

Full Text Available Herein, we evaluated the use of paper towel, waxed paper, and Parafilm M® (Heathrow Scientific, Vernon Hills, IL, USA as alternative substrates for screen-printed sensor manufacturing. Morphological study was performed to evaluate the adhesion of the ink on these uncommon substrates, as well as the morphology of the working electrode. The electrochemical characterization was carried out using ferricyanide/ferrocyanide as redox couple. To enhance the electrochemical properties of the developed sensors, the nanomaterial carbon black was used as nanomodifier. The modification by drop casting of the working electrode surface, using a stable dispersion of carbon black, allows to obtain a sensor with improved electrochemical behavior in terms of peak-to-peak separation, current intensity, and the resistance of charge transfer. The results achieved confirm the possibility of printing the electrode on several cost-effective paper-based materials and the improvement of the electrochemical behavior by using carbon black as sustainable nanomaterial.

Development of high temperature reference electrodes for in-pile application: Part I. Feasibility study of the external pressure balanced Ag/AgCl reference electrode (EPBRE) and the cathodically charged Palladium hydrogen electrode

International Nuclear Information System (INIS)

Bosch, R.W.; Van Nieuwenhove, R.

1998-10-01

The main problems connected with corrosion potential measurements at elevated temperatures and pressures are related to the stability and lifetime of the reference electrode and the correct estimation of the potential related to the Standard Hydrogen Scale (SHE). Under Pressurised Water Reactor (PWR) conditions of 300 degrees Celsius and 150 bar, the choice of materials is also a limiting factor due to the influence of radiation. Investigations on two reference electrodes that can be used under PWR conditions are reported: the cathodically charged palladium hydrogen electrode, and the external pressure balanced silver/silver chloride electrode. Preliminary investigations with the Pd-electrode were focused on the calculation of the required charging time and the influence of dissolved oxygen. High temperature applications are discussed on the basis of results reported in the literature. Investigations with the silver/silver chloride reference electrode mainly dealt with the salt bridge which is necessary to connect the reference electrode with the testing solution. It is shown that the thermal junction potential is independent of the length of the salt bridge. In addition, the high temperature contributes to an increase of the conductivity of the solution, which is beneficial for the salt bridge connection

Development of Advanced Life Cycle Costing Methods for Technology Benefit/Cost/Risk Assessment

Science.gov (United States)

Yackovetsky, Robert (Technical Monitor)

2002-01-01

The overall objective of this three-year grant is to provide NASA Langley's System Analysis Branch with improved affordability tools and methods based on probabilistic cost assessment techniques. In order to accomplish this objective, the Aerospace Systems Design Laboratory (ASDL) needs to pursue more detailed affordability, technology impact, and risk prediction methods and to demonstrate them on variety of advanced commercial transports. The affordability assessment, which is a cornerstone of ASDL methods, relies on the Aircraft Life Cycle Cost Analysis (ALCCA) program originally developed by NASA Ames Research Center and enhanced by ASDL. This grant proposed to improve ALCCA in support of the project objective by updating the research, design, test, and evaluation cost module, as well as the engine development cost module. Investigations into enhancements to ALCCA include improved engine development cost, process based costing, supportability cost, and system reliability with airline loss of revenue for system downtime. A probabilistic, stand-alone version of ALCCA/FLOPS will also be developed under this grant in order to capture the uncertainty involved in technology assessments. FLOPS (FLight Optimization System program) is an aircraft synthesis and sizing code developed by NASA Langley Research Center. This probabilistic version of the coupled program will be used within a Technology Impact Forecasting (TIF) method to determine what types of technologies would have to be infused in a system in order to meet customer requirements. A probabilistic analysis of the CER's (cost estimating relationships) within ALCCA will also be carried out under this contract in order to gain some insight as to the most influential costs and the impact that code fidelity could have on future RDS (Robust Design Simulation) studies.

Screen-Printed Graphite Electrodes as Low-Cost Devices for Oxygen Gas Detection in Room-Temperature Ionic Liquids

Directory of Open Access Journals (Sweden)

Junqiao Lee

2017-11-01

Full Text Available Screen-printed graphite electrodes (SPGEs have been used for the first time as platforms to detect oxygen gas in room-temperature ionic liquids (RTILs. Up until now, carbon-based SPEs have shown inferior behaviour compared to platinum and gold SPEs for gas sensing with RTIL solvents. The electrochemical reduction of oxygen (O2 in a range of RTILs has therefore been explored on home-made SPGEs, and is compared to the behaviour on commercially-available carbon SPEs (C-SPEs. Six common RTILs are initially employed for O2 detection using cyclic voltammetry (CV, and two RTILs ([C2mim][NTf2] and [C4mim][PF6] chosen for further detailed analytical studies. Long-term chronoamperometry (LTCA was also performed to test the ability of the sensor surface for real-time gas monitoring. Both CV and LTCA gave linear calibration graphs—for CV in the 10–100% vol. range, and for LTCA in the 0.1–20% vol. range—on the SPGE. The responses on the SPGE were far superior to the commercial C-SPEs; more instability in the electrochemical responses were observed on the C-SPEs, together with some breaking-up or dissolution of the electrode surface materials. This study highlights that not all screen-printed ink formulations are compatible with RTIL solvents for longer-term electrochemical experiments, and that the choice of RTIL is also important. Overall, the low-cost SPGEs appear to be promising platforms for the detection of O2, particularly in [C4mim][PF6].

Cost-effective flow injection amperometric system with metal nanoparticle loaded carbon nanotube modified screen printed carbon electrode for sensitive determination of hydrogen peroxide.

Science.gov (United States)

Reanpang, Preeyaporn; Themsirimongkon, Suwaphid; Saipanya, Surin; Chailapakul, Orawon; Jakmunee, Jaroon

2015-11-01

Various metal nanoparticles (NPs) decorated on carbon nanotube (CNT) was modified on the home-made screen printed carbon electrode (SPCE) in order to enhances sensitivity of hydrogen peroxide (H2O2) determination. The simple casting method was used for the electrode modification. The monometallic and bimetallic NPs modified electrodes were investigated for their electrochemical properties for H2O2 reduction. The Pd-CNT/SPCE is appropriated to measure the H2O2 reduction at a potential of -0.3 V, then this modified electrode was incorporated with a home-made flow through cell and applied in a simple flow injection amperometry (FI-Amp). Some parameters influencing the resulted modified electrode and the FI-Amp system were studied. The proposed detection system was able to detect H2O2 in the range of 0.1-1.0 mM, with detection limit of 20 µM. Relative standard deviation for 100 replicated injections of 0.6 mM H2O2 was 2.3%. The reproducibility of 6 electrodes preparing in 3 different lots was 8.2%. It was demonstrated for determination of H2O2 in disinfectant, hair colorant and milk samples. Recoveries in the range of 90-109% were observed. The developed system provided high stability, good repeatability, high sample throughput and low reagent consumption. Copyright © 2015 Elsevier B.V. All rights reserved.

Study and development of membrane electrode assemblies for Proton Exchange Membrane Fuel Cell (PEMFC) with palladium based catalysts

International Nuclear Information System (INIS)

Bonifacio, Rafael Nogueira

2013-01-01

PEMFC systems are capable of generating electricity with high efficiency and low or no emissions, but durability and cost issues prevent its large commercialization. In this work MEA with palladium based catalysts were developed, Pd/C, Pt/C and alloys PdPt/C catalysts with different ratios between metals and carbon were synthesized and characterized. A study of the ratio between catalyst and Nafion Ionomer for formation of high performance triple-phase reaction was carried out, a mathematical model to implement this adjustment to catalysts with different relations between metal and support taking into account the volumetric aspects of the catalyst layer was developed and then a study of the catalyst layer thickness was performed. X-ray diffraction, Transmission and Scanning Electron Microscopy, X-ray Energy Dispersive, Gas Pycnometry, Mercury Intrusion Porosimetry, Gas adsorption according to the BET and BJH equations, and Thermo Gravimetric Analysis techniques were used for characterization and particle size, specific surface areas and lattice parameters determinations were also carried out. All catalysts were used on MEAs preparation and evaluated in 5 cm 2 single cell from 25 to 100 °C at 1 atm and the best composition was also evaluated at 3 atm. In the study of metals for reactions, to reduce the platinum applied to the electrodes without performance losses, Pd/C and PdPt/C 1:1 were selected for anodes and cathodes, respectively. The developed MEA structure used 0,25 mgPt.cm -2 , showing power densities up to 550 mW.cm -2 and power of 2.2 kW net per gram of platinum. The estimated costs showed that there was a reduction of up to 64.5 %, compared to the MEA structures previously known. Depending on the temperature and operating pressure, values from US$ 1,475.30 to prepare MEAs for each installed kilowatt were obtained. Taking into account recent studies, it was concluded that the cost of the developed MEA is compatible with PEMFC stationary application

Miniaturized, Planar Ion-selective Electrodes Fabricated by Means of Thick-film Technology

Directory of Open Access Journals (Sweden)

Robert Koncki

2006-04-01

Full Text Available Various planar technologies are employed for developing solid-state sensorshaving low cost, small size and high reproducibility; thin- and thick-film technologies aremost suitable for such productions. Screen-printing is especially suitable due to itssimplicity, low-cost, high reproducibility and efficiency in large-scale production. Thistechnology enables the deposition of a thick layer and allows precise pattern control.Moreover, this is a highly economic technology, saving large amounts of the used inks. Inthe course of repetitions of the film-deposition procedure there is no waste of material dueto additivity of this thick-film technology. Finally, the thick films can be easily and quicklydeposited on inexpensive substrates. In this contribution, thick-film ion-selective electrodesbased on ionophores as well as crystalline ion-selective materials dedicated forpotentiometric measurements are demonstrated. Analytical parameters of these sensors arecomparable with those reported for conventional potentiometric electrodes. All mentionedthick-film strip electrodes have been totally fabricated in only one, fully automated thick-film technology, without any additional manual, chemical or electrochemical steps. In allcases simple, inexpensive, commercially available materials, i.e. flexible, plastic substratesand easily cured polymer-based pastes were used.

Electrochemical determination of serotonin in urine samples based on metal oxide nanoparticles/MWCNT on modified glassy carbon electrode

Directory of Open Access Journals (Sweden)

Omolola E. Fayemi

2017-04-01

Full Text Available The electrochemical response of serotonin on the modified electrode based on multiwalled-carbon-nanotube (MWCNT doped respectively with nickel, zinc and iron oxide nanoparticles coating on glassy carbon electrode (GCE at physiological pH 7 was determined using cyclic voltammetry (CV and square wave voltammetry (SWV. The modified GCE/MWCNT-metal oxide electrodes exhibited excellent electrocatalytic activity towards the detection of serotonin at large peak current and lower oxidation potentials compared to other electrodes investigated. The dynamic range for the serotonin determination was between 5.98 × 10−3 μM to 62.8 μM with detection limits 118, 129 and 166 nM for GCE/MWCNT-NiO, GCE/MWCNT-ZnO and GCE/MWCNT-Fe3O4 sensors respectively. GCE-MWCNT-NiO was the best electrode in terms of serotonin current response, electrode stability, resistance to fouling and limit of detection towards the analyte. The developed sensors were found to be electrochemically stable, reusable, economically effective due to their extremely low operational cost, and have demonstrated good limit of detection, sensitivity and selectivity towards serotonin determination in urine samples. Keywords: Metal oxides nanoparticles, Multiwalled carbon nanotubes, Glassy carbon electrode, Serotonin, Cyclic voltammetry, Square wave voltammetry

Polyaniline (PANi based electrode materials for energy storage and conversion

Directory of Open Access Journals (Sweden)

Huanhuan Wang

2016-09-01

Full Text Available Polyaniline (PANi as one kind of conducting polymers has been playing a great role in the energy storage and conversion devices besides carbonaceous materials and metallic compounds. Due to high specific capacitance, high flexibility and low cost, PANi has shown great potential in supercapacitor. It alone can be used in fabricating an electrode. However, the inferior stability of PANi limits its application. The combination of PANi and other active materials (carbon materials, metal compounds or other polymers can surpass these intrinsic disadvantages of PANi. This review summarizes the recent progress in PANi based composites for energy storage/conversion, like application in supercapacitors, rechargeable batteries, fuel cells and water hydrolysis. Besides, PANi derived nitrogen-doped carbon materials, which have been widely employed as carbon based electrodes/catalysts, are also involved in this review. PANi as a promising material for energy storage/conversion is deserved for intensive study and further development.

Electrical resistance tomography using steel cased boreholes as long electrodes

International Nuclear Information System (INIS)

Daily, W; Newmark, R L; Ramirez, A

1999-01-01

Electrical resistance tomography (ERT) using multiple electrodes installed in boreholes has been shown to be useful for both site characterization and process monitoring. In some cases, however, installing multiple downhole electrodes is too costly (e.g., deep targets) or risky (e.g., contaminated sites). For these cases we have examined the possibility of using the steel casings of existing boreholes as electrodes. Several possibilities can be considered. The first case we investigated uses an array of steel casings as electrodes. This results in very few data and thus requires additional constraints to limit the domain of possible inverse solutions. Simulations indicate that the spatial resolution and sensitivity are understandably low but it is possible to coarsely map the lateral extent of subsurface processes such as steam floods. The second case uses an array of traditional point borehole electrodes combined with long-conductor electrodes (steel casings). Although this arrangement provides more data, in many cases it results in poor reconstructions of test targets. Results indicate that this method may hold promise for low resolution imaging where steel casings can be used as electrodes but the merits depend strongly on details of each application. Field tests using these configurations are currently being conducted

Electrolytic photodissociation of chemical compounds by iron oxide electrodes

Science.gov (United States)

Somorjai, Gabor A.; Leygraf, Christofer H.

1984-01-01

Chemical compounds can be dissociated by contacting the same with a p/n type semi-conductor diode having visible light as its sole source of energy. The diode consists of low cost, readily available materials, specifically polycrystalline iron oxide doped with silicon in the case of the n-type semi-conductor electrode, and polycrystalline iron oxide doped with magnesium in the case of the p-type electrode. So long as the light source has an energy greater than 2.2 electron volts, no added energy source is needed to achieve dissociation.

A top-down approach for fabricating free-standing bio-carbon supercapacitor electrodes with a hierarchical structure.

Science.gov (United States)

Li, Yingzhi; Zhang, Qinghua; Zhang, Junxian; Jin, Lei; Zhao, Xin; Xu, Ting

2015-09-23

Biomass has delicate hierarchical structures, which inspired us to develop a cost-effective route to prepare electrode materials with rational nanostructures for use in high-performance storage devices. Here, we demonstrate a novel top-down approach for fabricating bio-carbon materials with stable structures and excellent diffusion pathways; this approach is based on carbonization with controlled chemical activation. The developed free-standing bio-carbon electrode exhibits a high specific capacitance of 204 F g(-1) at 1 A g(-1); good rate capability, as indicated by the residual initial capacitance of 85.5% at 10 A g(-1); and a long cycle life. These performance characteristics are attributed to the outstanding hierarchical structures of the electrode material. Appropriate carbonization conditions enable the bio-carbon materials to inherit the inherent hierarchical texture of the original biomass, thereby facilitating effective channels for fast ion transfer. The macropores and mesopores that result from chemical activation significantly increase the specific surface area and also play the role of temporary ion-buffering reservoirs, further shortening the ionic diffusion distance.

Conductive Hydrogel Electrodes for Delivery of Long-Term High Frequency Pulses

Directory of Open Access Journals (Sweden)

Naomi A. Staples

2018-01-01

Full Text Available Nerve block waveforms require the passage of large amounts of electrical energy at the neural interface for extended periods of time. It is desirable that such waveforms be applied chronically, consistent with the treatment of protracted immune conditions, however current metal electrode technologies are limited in their capacity to safely deliver ongoing stable blocking waveforms. Conductive hydrogel (CH electrode coatings have been shown to improve the performance of conventional bionic devices, which use considerably lower amounts of energy than conventional metal electrodes to replace or augment sensory neuron function. In this study the application of CH materials was explored, using both a commercially available platinum iridium (PtIr cuff electrode array and a novel low-cost stainless steel (SS electrode array. The CH was able to significantly increase the electrochemical performance of both array types. The SS electrode coated with the CH was shown to be stable under continuous delivery of 2 mA square pulse waveforms at 40,000 Hz for 42 days. CH coatings have been shown as a beneficial electrode material compatible with long-term delivery of high current, high energy waveforms.

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.

Handcrafted Electrocorticography Electrodes for a Rodent Behavioral Model

Directory of Open Access Journals (Sweden)

Nishat Tasnim

2016-08-01

Full Text Available Electrocorticography (ECoG is a minimally invasive neural recording method that has been extensively used for neuroscience applications. It has proven to have the potential to ease the establishment of proper links for neural interfaces that can offer disabled patients an alternative solution for their lost sensory and motor functions through the use of brain-computer interface (BCI technology. Although many neural recording methods exist, ECoG provides a combination of stability, high spatial and temporal resolution with chronic and mobile capabilities that could make BCI systems accessible for daily applications. However, many ECoG electrodes require MEMS fabricating techniques which are accompanied by various expenses that are obstacles for research projects. For this reason, this paper presents an animal study using a low cost and simple handcrafted ECoG electrode that is made of commercially accessible materials. The study is performed on a Lewis rat implanted with a handcrafted 32-channel non-penetrative ECoG electrode covering an area of 3 × 3 mm2 on the cortical surface. The ECoG electrodes were placed on the motor and somatosensory cortex to record the signal patterns while the animal was active on a treadmill. Using a Tucker-Davis Technologies acquisition system and the software Synapse to monitor and analyze the electrophysiological signals, the electrodes obtained signals within the amplitude range of 200 µV for local field potentials with reliable spatiotemporal profiles. It was also confirmed that the handcrafted ECoG electrode has the stability and chronic features found in other commercial electrodes.

Activated graphene nanoplatelets as a counter electrode for dye-sensitized solar cells

Energy Technology Data Exchange (ETDEWEB)

Gong, Jiawei [Center for Advanced Photovoltaics, Department of Electrical Engineering, South Dakota State University, Brookings, South Dakota 57007 (United States); Department of Mechanical Engineering, North Dakota State University, Fargo, North Dakota 58102 (United States); Zhou, Zhengping; Qiao, Qiquan, E-mail: qiquan.qiao@sdstate.edu [Center for Advanced Photovoltaics, Department of Electrical Engineering, South Dakota State University, Brookings, South Dakota 57007 (United States); Sumathy, K. [Department of Mechanical Engineering, North Dakota State University, Fargo, North Dakota 58102 (United States); Yang, Huojun [Department of Construction Management and Engineering, North Dakota State University, Fargo, North Dakota 58102 (United States)

2016-04-07

Activated graphene nanoplatelets (aGNPs) prepared by a hydrothermal method using KOH as activating agent were used as counter electrode for high efficiency dye-sensitized solar cells (DSSCs). After the KOH activation, the scanning electron microscopy image shows that aGNPs demonstrate a more curled, rough, and porous morphology which could contain both micro- and mesopores. The KOH activation changed the stacked layers of GNPs to a more crumpled and curved morphology. The microstructure of large pores significantly increased the electrode surface area and roughness, leading to the high electrocatalytic activity for triiodide reduction at the counter electrode. The DSSCs fabricated using aGNP as counter electrodes were tested under standard AM 1.5 illumination with an intensity of 91.5 mW/cm{sup 2}. The device achieved an overall power conversion efficiency of 7.7%, which is comparable to the conventional platinum counter electrode (8%). Therefore, the low cost and high performance aGNP based counter electrode is a promising alternative to conventional Pt counter electrode in DSSCs.

Nickel–copper hybrid electrodes self-adhered onto a silicon wafer by supersonic cold-spray

International Nuclear Information System (INIS)

Lee, Jong-Gun; Kim, Do-Yeon; Kang, Byungjun; Kim, Donghwan; Song, Hee-eun; Kim, Jooyoung; Jung, Woonsuk; Lee, Dukhaeng; Al-Deyab, Salem S.; James, Scott C.; Yoon, Sam S.

2015-01-01

High-performance electrodes are fabricated through supersonic spraying of nickel and copper particles. These electrodes yield low specific resistivities, comparable to electrodes produced by screen-printed silver paste and light-induced plating. The appeal of this fabrication method is the low cost of copper and large area scalability of supersonic spray-coating techniques. The copper and nickel electrode was fabricated in the open air without any pre- or post-treatment. The spray-coated copper–nickel electrode was characterized by optical microscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction, and energy dispersive spectroscopy. Although both SEM and TEM images confirmed voids trapped between flattened particles in the fabricated electrode, this electrode’s resistivity was order 10 −6 Ω cm, which is comparable to the bulk value for pure copper

Highly Conformal Ni Micromesh as a Current Collecting Front Electrode for Reduced Cost Si Solar Cell

DEFF Research Database (Denmark)

Gupta, Nikita; Rao, K. D. M.; Gupta, Ritu

2017-01-01

deposition of Ni wire network on corrugated solar cell, a short circuit current of 33.28 mA/cm2 was obtained in comparison to 20.53 mA/cm2 without the network electrode. On comparing the efficiency with the conventional cells with screen printed electrodes, a 20% increment in efficiency has been observed...

Emerging Prototype Sodium-Ion Full Cells with Nanostructured Electrode Materials.

Science.gov (United States)

Ren, Wenhao; Zhu, Zixuan; An, Qinyou; Mai, Liqiang

2017-06-01

Due to steadily increasing energy consumption, the demand of renewable energy sources is more urgent than ever. Sodium-ion batteries (SIBs) have emerged as a cost-effective alternative because of the earth abundance of Na resources and their competitive electrochemical behaviors. Before practical application, it is essential to establish a bridge between the sodium half-cell and the commercial battery from a full cell perspective. An overview of the major challenges, most recent advances, and outlooks of non-aqueous and aqueous sodium-ion full cells (SIFCs) is presented. Considering the intimate relationship between SIFCs and electrode materials, including structure, composition and mutual matching principle, both the advance of various prototype SIFCs and the electrochemistry development of nanostructured electrode materials are reviewed. It is noted that a series of SIFCs combined with layered oxides and hard carbon are capable of providing a high specific gravimetric energy above 200 Wh kg -1 , and an NaCrO 2 //hard carbon full cell is able to deliver a high rate capability over 100 C. To achieve industrialization of SIBs, more systematic work should focus on electrode construction, component compatibility, and battery technologies. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Organometal halide perovskite light-emitting diodes with laminated carbon nanotube electrodes

Science.gov (United States)

Shan, Xin; Bade, Sri Ganesh R.; Geske, Thomas; Davis, Melissa; Smith, Rachel; Yu, Zhibin

2017-08-01

Organometal halide perovskite light-emitting diodes (LEDs) with laminated carbon nanotube (CNT) electrodes are reported. The LEDs have an indium tin oxide (ITO) bottom electrode, a screen printed methylammonium lead tribromide (MAPbBr3)/polymer composite thin film as the emissive layer, and laminated CNT as the top electrode. The devices can be turned on at 2.2 V, reaching a brightness of 4,960 cd m-2 and a current efficiency of 1.54 cd A-1 at 6.9 V. The greatly simplified fabrication process in this work can potentially lead to the scalable manufacturing of large size and low cost LED panels in the future.

Freestanding nanocellulose-composite fibre reinforced 3D polypyrrole electrodes for energy storage applications

Science.gov (United States)

Wang, Zhaohui; Tammela, Petter; Zhang, Peng; Huo, Jinxing; Ericson, Fredric; Strømme, Maria; Nyholm, Leif

2014-10-01

It is demonstrated that 3D nanostructured polypyrrole (3D PPy) nanocomposites can be reinforced with PPy covered nanocellulose (PPy@nanocellulose) fibres to yield freestanding, mechanically strong and porosity optimised electrodes with large surface areas. Such PPy@nanocellulose reinforced 3D PPy materials can be employed as free-standing paper-like electrodes in symmetric energy storage devices exhibiting cell capacitances of 46 F g-1, corresponding to specific electrode capacitances of up to ~185 F g-1 based on the weight of the electrode, and 5.5 F cm-2 at a current density of 2 mA cm-2. After 3000 charge/discharge cycles at 30 mA cm-2, the reinforced 3D PPy electrode material also showed a cell capacitance corresponding to 92% of that initially obtained. The present findings open up new possibilities for the fabrication of high performance, low-cost and environmentally friendly energy-storage devices based on nanostructured paper-like materials.It is demonstrated that 3D nanostructured polypyrrole (3D PPy) nanocomposites can be reinforced with PPy covered nanocellulose (PPy@nanocellulose) fibres to yield freestanding, mechanically strong and porosity optimised electrodes with large surface areas. Such PPy@nanocellulose reinforced 3D PPy materials can be employed as free-standing paper-like electrodes in symmetric energy storage devices exhibiting cell capacitances of 46 F g-1, corresponding to specific electrode capacitances of up to ~185 F g-1 based on the weight of the electrode, and 5.5 F cm-2 at a current density of 2 mA cm-2. After 3000 charge/discharge cycles at 30 mA cm-2, the reinforced 3D PPy electrode material also showed a cell capacitance corresponding to 92% of that initially obtained. The present findings open up new possibilities for the fabrication of high performance, low-cost and environmentally friendly energy-storage devices based on nanostructured paper-like materials. Electronic supplementary information (ESI) available. See DOI: 10.1039/c

Poly(dimethylsiloxane) cross-linked carbon paste electrodes for microfluidic electrochemical sensing.

Science.gov (United States)

Sameenoi, Yupaporn; Mensack, Meghan M; Boonsong, Kanokporn; Ewing, Rebecca; Dungchai, Wijitar; Chailapakul, Orawan; Cropek, Donald M; Henry, Charles S

2011-08-07

Recently, the development of electrochemical biosensors as part of microfluidic devices has garnered a great deal of attention because of the small instrument size and portability afforded by the integration of electrochemistry in microfluidic systems. Electrode fabrication, however, has proven to be a major obstacle in the field. Here, an alternative method to create integrated, low cost, robust, patternable carbon paste electrodes (CPEs) for microfluidic devices is presented. The new CPEs are composed of graphite powder and a binder consisting of a mixture of poly(dimethylsiloxane) (PDMS) and mineral oil. The electrodes are made by filling channels molded in previously cross-linked PDMS using a method analogous to screen printing. The optimal binder composition was investigated to obtain electrodes that were physically robust and performed well electrochemically. After studying the basic electrochemistry, the PDMS-oil CPEs were modified with multi-walled carbon nanotubes (MWCNT) and cobalt phthalocyanine (CoPC) for the detection of catecholamines and thiols, respectively, to demonstrate the ease of electrode chemical modification. Significant improvement of analyte signal detection was observed from both types of modified CPEs. A nearly 2-fold improvement in the electrochemical signal for 100 μM dithiothreitol (DTT) was observed when using a CoPC modified electrode (4.0 ± 0.2 nA (n = 3) versus 2.5 ± 0.2 nA (n = 3)). The improvement in signal was even more pronounced when looking at catecholamines, namely dopamine, using MWCNT modified CPEs. In this case, an order of magnitude improvement in limit of detection was observed for dopamine when using the MWCNT modified CPEs (50 nM versus 500 nM). CoPC modified CPEs were successfully used to detect thiols in red blood cell lysate while MWCNT modified CPEs were used to monitor temporal changes in catecholamine release from PC12 cells following stimulation with potassium.

Optimization of spin-coated electrodes for electrolyte-supported solid oxide fuel cells

International Nuclear Information System (INIS)

Nobrega, Shayenne Diniz da; Monteiro, Natalia Kondo; Tabuti, Francisco; Fonseca, Fabio Coral; Florio, Daniel Zanetti de

2017-01-01

Electrodes for electrolyte-supported solid oxide fuel cells (SOFC’s) were fabricated by spin coating. Strontium-doped lanthanum manganite (LSM) cathode and nickel yttria-stabilized zirconia cermet anodes were synthesized and processed for enhanced deposition conditions. The influence of electrode microstructural parameters was investigated by a systematic experimental procedure aiming at optimized electrochemical performance of single cells. Polarization curves showed a strong dependence on both electrode thickness and sintering temperature. By a systematic control of such parameters, the performance of single cells was significantly enhanced due to decreasing of polarization resistance from 26 Ω cm² to 0.6 Ω cm² at 800°C. The results showed that spin-coated electrodes can be optimized for fast and cost effective fabrication of SOFCs. (author)

Optimization of spin-coated electrodes for electrolyte-supported solid oxide fuel cells

Energy Technology Data Exchange (ETDEWEB)

Nobrega, Shayenne Diniz da; Monteiro, Natalia Kondo; Tabuti, Francisco; Fonseca, Fabio Coral, E-mail: shaynnedn@hotmail.com, E-mail: nataliakm@usp.br, E-mail: fntabuti@ipen.br, E-mail: fabiocf@usp.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN/SP), Sao Paulo, SP (Brazil); Florio, Daniel Zanetti de, E-mail: daniel.florio@ufabc.edu.br [Universidade Federal do ABC (UFABC), Santo Andre, SP (Brazil)

2017-01-15

Electrodes for electrolyte-supported solid oxide fuel cells (SOFC’s) were fabricated by spin coating. Strontium-doped lanthanum manganite (LSM) cathode and nickel yttria-stabilized zirconia cermet anodes were synthesized and processed for enhanced deposition conditions. The influence of electrode microstructural parameters was investigated by a systematic experimental procedure aiming at optimized electrochemical performance of single cells. Polarization curves showed a strong dependence on both electrode thickness and sintering temperature. By a systematic control of such parameters, the performance of single cells was significantly enhanced due to decreasing of polarization resistance from 26 Ω cm² to 0.6 Ω cm² at 800°C. The results showed that spin-coated electrodes can be optimized for fast and cost effective fabrication of SOFCs. (author)

Impact of uniform electrode current distribution on ETF. [Engineering Test Facility MHD generator

Science.gov (United States)

Bents, D. J.

1982-01-01

A basic reason for the complexity and sheer volume of electrode consolidation hardware in the MHD ETF Powertrain system is the channel electrode current distribution, which is non-uniform. If the channel design is altered to provide uniform electrode current distribution, the amount of hardware required decreases considerably, but at the possible expense of degraded channel performance. This paper explains the design impacts on the ETF electrode consolidation network associated with uniform channel electrode current distribution, and presents the alternate consolidation designs which occur. They are compared to the baseline (non-uniform current) design with respect to performance, and hardware requirements. A rational basis is presented for comparing the requirements for the different designs and the savings that result from uniform current distribution. Performance and cost impacts upon the combined cycle plant are discussed.

Parametric Cost and Schedule Modeling for Early Technology Development

Science.gov (United States)

2018-04-02

Research NoteNational Security Rep rt PARAMETRIC MODELING FOR EARLY TECHNOLOGY DEVELOPMENT COST AND SCHEDULE Chuck...Alexander NSR_11x17_Cover_CostModeling_v8.indd 1 11/20/17 3:15 PM PARAMETRIC COST AND SCHEDULE MODELING FOR EARLY  TECHNOLOGY DEVELOPMENT Chuck...COST AND SCHEDULE MODELING FOR EARLY  TECHNOLOGY DEVELOPMENT iii Contents Figures

Textile Concentric Ring Electrodes for ECG Recording Based on Screen-Printing Technology

Directory of Open Access Journals (Sweden)

José Vicente Lidón-Roger

2018-01-01

Full Text Available Among many of the electrode designs used in electrocardiography (ECG, concentric ring electrodes (CREs are one of the most promising due to their enhanced spatial resolution. Their development has undergone a great push due to their use in recent years; however, they are not yet widely used in clinical practice. CRE implementation in textiles will lead to a low cost, flexible, comfortable, and robust electrode capable of detecting high spatial resolution ECG signals. A textile CRE set has been designed and developed using screen-printing technology. This is a mature technology in the textile industry and, therefore, does not require heavy investments. Inks employed as conductive elements have been silver and a conducting polymer (poly (3,4-ethylenedioxythiophene polystyrene sulfonate; PEDOT:PSS. Conducting polymers have biocompatibility advantages, they can be used with flexible substrates, and they are available for several printing technologies. CREs implemented with both inks have been compared by analyzing their electric features and their performance in detecting ECG signals. The results reveal that silver CREs present a higher average thickness and slightly lower skin-electrode impedance than PEDOT:PSS CREs. As for ECG recordings with subjects at rest, both CREs allowed the uptake of bipolar concentric ECG signals (BC-ECG with signal-to-noise ratios similar to that of conventional ECG recordings. Regarding the saturation and alterations of ECGs captured with textile CREs caused by intentional subject movements, silver CREs presented a more stable response (fewer saturations and alterations than those of PEDOT:PSS. Moreover, BC-ECG signals provided higher spatial resolution compared to conventional ECG. This improved spatial resolution was manifested in the identification of P1 and P2 waves of atrial activity in most of the BC-ECG signals. It can be concluded that textile silver CREs are more suitable than those of PEDOT:PSS for obtaining

Textile Concentric Ring Electrodes for ECG Recording Based on Screen-Printing Technology.

Science.gov (United States)

Lidón-Roger, José Vicente; Prats-Boluda, Gema; Ye-Lin, Yiyao; Garcia-Casado, Javier; Garcia-Breijo, Eduardo

2018-01-21

Among many of the electrode designs used in electrocardiography (ECG), concentric ring electrodes (CREs) are one of the most promising due to their enhanced spatial resolution. Their development has undergone a great push due to their use in recent years; however, they are not yet widely used in clinical practice. CRE implementation in textiles will lead to a low cost, flexible, comfortable, and robust electrode capable of detecting high spatial resolution ECG signals. A textile CRE set has been designed and developed using screen-printing technology. This is a mature technology in the textile industry and, therefore, does not require heavy investments. Inks employed as conductive elements have been silver and a conducting polymer (poly (3,4-ethylenedioxythiophene) polystyrene sulfonate; PEDOT:PSS). Conducting polymers have biocompatibility advantages, they can be used with flexible substrates, and they are available for several printing technologies. CREs implemented with both inks have been compared by analyzing their electric features and their performance in detecting ECG signals. The results reveal that silver CREs present a higher average thickness and slightly lower skin-electrode impedance than PEDOT:PSS CREs. As for ECG recordings with subjects at rest, both CREs allowed the uptake of bipolar concentric ECG signals (BC-ECG) with signal-to-noise ratios similar to that of conventional ECG recordings. Regarding the saturation and alterations of ECGs captured with textile CREs caused by intentional subject movements, silver CREs presented a more stable response (fewer saturations and alterations) than those of PEDOT:PSS. Moreover, BC-ECG signals provided higher spatial resolution compared to conventional ECG. This improved spatial resolution was manifested in the identification of P1 and P2 waves of atrial activity in most of the BC-ECG signals. It can be concluded that textile silver CREs are more suitable than those of PEDOT:PSS for obtaining BC-ECG records

Evaluating the administration costs of biologic drugs: development of a cost algorithm.

Science.gov (United States)

Tetteh, Ebenezer K; Morris, Stephen

2014-12-01

Biologic drugs, as with all other medical technologies, are subject to a number of regulatory, marketing, reimbursement (financing) and other demand-restricting hurdles applied by healthcare payers. One example is the routine use of cost-effectiveness analyses or health technology assessments to determine which medical technologies offer value-for-money. The manner in which these assessments are conducted suggests that, holding all else equal, the economic value of biologic drugs may be determined by how much is spent on administering these drugs or trade-offs between drug acquisition and administration costs. Yet, on the supply-side, it seems very little attention is given to how manufacturing and formulation choices affect healthcare delivery costs. This paper evaluates variations in the administration costs of biologic drugs, taking care to ensure consistent inclusion of all relevant cost resources. From this, it develops a regression-based algorithm with which manufacturers could possibly predict, during process development, how their manufacturing and formulation choices may impact on the healthcare delivery costs of their products.

Probing Electrode Heterogeneity Using Fourier-Transformed Alternating Current Voltammetry: Application to a Dual-Electrode Configuration.

Science.gov (United States)

Tan, Sze-Yin; Unwin, Patrick R; Macpherson, Julie V; Zhang, Jie; Bond, Alan M

2017-03-07

Quantitative studies of electron transfer processes at electrode/electrolyte interfaces, originally developed for homogeneous liquid mercury or metallic electrodes, are difficult to adapt to the spatially heterogeneous nanostructured electrode materials that are now commonly used in modern electrochemistry. In this study, the impact of surface heterogeneity on Fourier-transformed alternating current voltammetry (FTACV) has been investigated theoretically under the simplest possible conditions where no overlap of diffusion layers occurs and where numerical simulations based on a 1D diffusion model are sufficient to describe the mass transport problem. Experimental data that meet these requirements can be obtained with the aqueous [Ru(NH 3 ) 6 ] 3+/2+ redox process at a dual-electrode system comprised of electrically coupled but well-separated glassy carbon (GC) and boron-doped diamond (BDD) electrodes. Simulated and experimental FTACV data obtained with this electrode configuration, and where distinctly different heterogeneous charge transfer rate constants (k 0 values) apply at the individual GC and BDD electrode surfaces, are in excellent agreement. Principally, because of the far greater dependence of the AC current magnitude on k 0 , it is straightforward with the FTACV method to resolve electrochemical heterogeneities that are ∼1-2 orders of magnitude apart, as applies in the [Ru(NH 3 ) 6 ] 3+/2+ dual-electrode configuration experiments, without prior knowledge of the individual kinetic parameters (k 0 1 and k 0 2 ) or the electrode size ratio (θ 1 :θ 2 ). In direct current voltammetry, a difference in k 0 of >3 orders of magnitude is required to make this distinction.

Final report: Seven-layer membrane electrode assembly - an innovative approach to PEM fuel cell design

Energy Technology Data Exchange (ETDEWEB)

Chapman, A.

2005-07-01

Costs of materials and fabrication, rather than appropriateness of technology, are the major barriers to the sales of fuel cells. With the objective of reducing costs, potential alternative component materials for (a) the fluid flow plate (FFP) and (b) the gas diffusion layers were investigated. The concept of a 7-layer membrane electrode assembly (MEA), in which components are bonded into a unitised module, was also studied. The advantages of the bonded cell, and the flow field design, are expounded. Low-cost carbon particle composites were developed for the FFPs. The modular 7-layer MEA has an order of magnitude saving over current materials. Overall, the study has led to a greater volumetric power output, lower costs and greater reliability. The work was carried out by Morgan Group Technology Limited and funded by the DTI.

Design and development of plasmonic nanostructured electrodes for ITO-free organic photovoltaic cells on rigid and highly flexible substrates

Science.gov (United States)

Richardson, Beau J.; Zhu, Leize; Yu, Qiuming

2017-04-01

Indium tin oxide (ITO) is the most common transparent electrode used in organic photovoltaics (OPVs), yet limited indium reserves and poor mechanical properties make it non-ideal for large-scale OPV production. To replace ITO, we designed, fabricated, and deployed plasmonic nanostructured electrodes in inverted OPV devices. We found that active layer absorption is significantly impacted by ZnO thickness which affects the optical field distribution inside the resonant cavity formed between the plasmonic nanostructured electrode and top electrode. High quality Cr/Au nanostructured electrodes were fabricated by nanoimprint lithography and deployed in ITO-free inverted devices on glass. Devices with thinner ZnO showed a PCE as high as 5.70% and higher J SC’s than devices on thicker ZnO, in agreement with finite-difference time-domain simulations. In addition, as the active layer was made optically thin, ITO-based devices showed diminished J SC while the resonant cavity effect from plasmonic nanostructured electrodes retained J SC. Preliminary ITO-free, flexible devices on PET showed a PCE of 1.82% and those fabricated on ultrathin and conformable Parylene substrates yielded an initial PCE over 1%. The plasmonic electrodes and device designs in this work show promise for developing highly functioning conformable devices that can be applied to numerous needs for lightweight, ubiquitous power generation.

New developments in nickel-hydrogen cell and battery design for commercial applications

Energy Technology Data Exchange (ETDEWEB)

Caldwell, D.B.; Fox, C.L.; Miller, L.E. [Eagle-Picher Industries, Inc., Joplin, MO (United States)

1997-12-31

Nickel-hydrogen (NiH{sub 2}) battery systems were first developed for space applications more than 20 years ago. Currently, they are being manufactured for commercial, terrestrial applications. The battery is ideal for commercial terrestrial energy storage applications because it offers a better potential cycle life than any other battery system and is maintenance free. A selection of low-cost components, electrodes, cell designs and battery designs are being tested to determine their feasibility for commercial applications. The dependent pressure vessel (DPV) design, developed by Eagle-Picher Industries, is the newest step in the continued development and evolution of the NiH{sub 2} system. The unique feature of the DPV cell design is the prismatic electrode stack which is more efficient than the cylindrical electrode stack. The electrode stack is the electrochemically active part of the cell. It contains nickel and hydrogen electrodes interspersed with an absorbent separator. DPV cells of two sizes, 40 and 60 Ah cells, have been developed. The DPV cell offers high specific energy at a reduced cost. The advanced DPV design also offers an efficient mechanical, electrical and thermal configuration and a reduced parts count. The design promotes compact, minimum volume packaging and weight efficiency. 8 refs., 7 figs.

The reversal constituent structure of photo-electrode in dye-sensitized solar cells

International Nuclear Information System (INIS)

Ting, Chen-Ching; Chao, Wei-Shi

2011-01-01

Highlights: → The new structure of photo-electrode in DSSC increases absorption of incident photons. → The substrate of copper mesh as photo-electrode reduces electric resistance. → Application of the copper mesh as substrate reduces the fabricating cost. → There are ca. 3 times increment of photoelectric conversion efficiency. → Application of the copper mesh as substrate can achieve the flexible DSSCs. - Abstract: This article presents significant experimental data about the dye-sensitized nano solar cells (DSSCs) using the new developed photo-electrode with reversal constituent structure in our CCT laboratory. The conventional constituent structure of a photo-electrode arranged in sequence from the incident light is the transparent conductive glass, the nano TiO 2 semi-conductive porous film, and the dye. In process, the photons energy of the incident light is mainly absorbed by the dye for DSSCs. This causes excited electrons in the dye to jump into conductive band of the TiO 2 and further to transfer into the outer circuit through the conductive glass. That is, a correct constituent structure of the photo-electrode arranged in sequence from the incident light in terms of the working principle should be the dye, the nano TiO 2 film, and the conductive substrate. The conventional constituent structure of the photo-electrode causes the incident light to be hindered by the TiO 2 layer. To reduce the light hindrance for the dye, this work used copper mesh as the conductive substrate and the nano TiO 2 was coated on it. In this way, the copper mesh connects the nano TiO 2 layer with the outer circuit and the holes of the copper mesh also allow the dye to contact with the electrolyte. The new developed constituent structure of the photo-electrode arranged in sequence from the incident light is the dye, the nano TiO 2 film, and the copper mesh. This new constituent structure, which increases amounts of the absorption light in the dye and further improved the

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.

Graphite electrode dc arc technology development for treatment of buried wastes

International Nuclear Information System (INIS)

Surma, J.E.; Cohn, D.R.; Smatlak, D.L.; Thomas, P.; Woskov, P.P.

1993-02-01

A ''National Laboratory-University-Industrial'' three-way partnership has been established between the Pacific Northwest Laboratory (PNL), Massachusetts Institute of Technology (MIT), and Electro-Pyrolysis, Inc. (EPI) to develop graphite electrode DC arc technology for the treatment of buried wastes. This paper outlines the PNL-MIT-EPI program describing a series of engineering-scale DC arc furnace tests conducted in an EPI furnace at the Plasma Fusion Center at MIT, and a description of the second phase of this program involving the design, fabrication, and testing of a pilot-scale DC arc furnace. Included in this work is the development and implementation of diagnostics to evaluate and optimize high temperature thermal processes such as the DC arc technology

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.

Cost performance assessment of in situ vitrification

International Nuclear Information System (INIS)

Showalter, W.E.; Letellier, B.C.; Booth, S.R.; Barnes-Smith, P.

1992-01-01

In situ vitrification (ISV) is a thermal treatment technology with promise for the destruction or immobilization of hazardous materials in contaminated soils. It has developed over the past decade to a level of maturity where meaningful cost effectiveness studies may be performed. The ISV process melts 4 to 25 m 2 of undisturbed soil to a maximum depth of 6 m into an obsidian-like glass waste form by applying electric current (3750 kill) between symmetrically spaced electrodes. Temperatures of approximately 2000 degree C drive off and destroy complex organics which are captured in an off-gas treatment system, while radio-nuclides are incorporated into the homogeneous glass monolith. A comparative life-cycle cost evaluation between mobile rotary kiln incineration and ISV was performed to quantitatively identify appropriate performance regimes and components of cost which are sensitive to the implementation of each technology. Predictions of melt times and power consumption were obtained from an ISV performance model over ranges of several parameters including electrode spacing, soil moisture, melt depth, electrical resistivity, and soil density. These data were coupled with manpower requirements, capitalization costs, and a melt placement optimization routine to allow interpolation over a wide variety of site characteristics. For the purpose of this study, a single site scenario representative of a mixed waste evaporation pond was constructed. Preliminary comparisons between ISV and incineration show that while operating costs are comparable, ISV avoids secondary treatment and monitored storage of radioactive waste that would be required following conventional incineration. It is the long term storage of incinerated material that is the most expensive component

Environmental Screening of Electrode Materials for a Rechargeable Aluminum Battery with an AlCl3/EMIMCl Electrolyte

Directory of Open Access Journals (Sweden)

Linda Ager-Wick Ellingsen

2018-06-01

Full Text Available Recently, rechargeable aluminum batteries have received much attention due to their low cost, easy operation, and high safety. As the research into rechargeable aluminum batteries with a room-temperature ionic liquid electrolyte is relatively new, research efforts have focused on finding suitable electrode materials. An understanding of the environmental aspects of electrode materials is essential to make informed and conscious decisions in aluminum battery development. The purpose of this study was to evaluate and compare the relative environmental performance of electrode material candidates for rechargeable aluminum batteries with an AlCl3/EMIMCl (1-ethyl-3-methylimidazolium chloride room-temperature ionic liquid electrolyte. To this end, we used a lifecycle environmental screening framework to evaluate 12 candidate electrode materials. We found that all of the studied materials are associated with one or more drawbacks and therefore do not represent a “silver bullet” for the aluminum battery. Even so, some materials appeared more promising than others did. We also found that aluminum battery technology is likely to face some of the same environmental challenges as Li-ion technology but also offers an opportunity to avoid others. The insights provided here can aid aluminum battery development in an environmentally sustainable direction.

Carbon felt and carbon fiber - A techno-economic assessment of felt electrodes for redox flow battery applications

Science.gov (United States)

Minke, Christine; Kunz, Ulrich; Turek, Thomas

2017-02-01

Carbon felt electrodes belong to the key components of redox flow batteries. The purpose of this techno-economic assessment is to uncover the production costs of PAN- and rayon-based carbon felt electrodes. Raw material costs, energy demand and the impact of processability of fiber and felt are considered. This innovative, interdisciplinary approach combines deep insights into technical, ecologic and economic aspects of carbon felt and carbon fiber production. Main results of the calculation model are mass balances, cumulative energy demands (CED) and the production costs of conventional and biogenic carbon felts supplemented by market assessments considering textile and carbon fibers.

Development of a membrane electrode as assembly production process for proton exchange membrane fuel cell (PEMFC) by sieve printing; Desenvolvimento de processo de producao de conjuntos eletrodo-membrana-eletrodo para celulas a combustivel baseadas no uso de membrana polimerica conditora de protons (PEMFC) por impressa a tela

Energy Technology Data Exchange (ETDEWEB)

Bonifacio, Rafael Nogueira

2010-07-01

Energy is a resource that presents historical trend of growth in demand. Projections indicate that future energy needs will require a massive use of hydrogen as fuel. The use of systems based on the use of proton exchange membrane fuel cell (PEMFC) has features that allow its application for stationary applications, automotive and portable power generation. The use of hydrogen as fuel for PEMFC has the advantage low pollutants' emission, when compared to fossil fuels. For the reactions in a PEMFC is necessary to build membrane electrode assembly (MEA). And the production of MEAs and its materials are relevant to the final cost of k W of power generated by systems of fuel cell. This represent currently a technological and financial barriers to large-scale application of this technology. In this work a process of MEAs fabrication were developed that showed high reproducibility, rapidity and low cost by sieve printing. The process of sieve printing and the ink composition as a precursor to the catalyst layer were developed, which allow the preparation of electrodes for MEAs fabrication with the implementation of the exact catalyst loading, 0.6 milligrams of platinum per square centimeters (mgPt.cm{sup -2}) suitable for cathodes and 0.4 mgPt.cm{sup -2} for anode in only one application step per electrode. The ink was developed, produced, characterized and used with similar characteristics to ink of sieve printing build for other applications. The MEAs produced had a performance of up to 712 m A.cm{sup -2} by 600 mV to 25 cm{sup 2} MEA area. The MEA cost production for MEAs of 247.86 cm{sup 2}, that can generate 1 kilowatt of energy was estimated to US$ 7,744.14 including cost of equipment, materials and labor. (author)

Experiment study on four button electrode used to monitor position of high current electron-beam

International Nuclear Information System (INIS)

Xu Tiezheng; Wang Huacen; Xie Yutong; Zhang Wenwei

2004-01-01

The button electrode is one that widely used in high energy accelerators, such as storage ring, and the button electrode has many merit like high accuracy, high resolution, resisting magnetic field, simple machinery, without magnetic core and low cost, etc. It's helpful that the button electrode is used as the beam position monitor in the linear induction accelerator. The experimental facilities have been designed and set up and it can simulate the beam of linear induction accelerator. The button electrode beam position monitor experiment have been done on the experimental facilities. The result of the experiment prove that the button electrode has an accuracy of 0.5 mm, and can reflect the wave of electron-beam accurately

Assessing a novel polymer-wick based electrode for EEG neurophysiological research.

Science.gov (United States)

Pasion, Rita; Paiva, Tiago O; Pedrosa, Paulo; Gaspar, Hugo; Vasconcelos, Beatriz; Martins, Ana C; Amaral, Maria H; Nóbrega, João M; Páscoa, Ricardo; Fonseca, Carlos; Barbosa, Fernando

2016-07-15

The EEG technique has decades of valid applications in clinical and experimental neurophysiology. EEG equipment and data analysis methods have been characterized by remarkable developments, but the skin-to-electrode signal transfer remains a challenge for EEG recording. A novel quasi-dry system - the polymer wick-based electrode - was developed to overcome the limitations of conventional dry and wet silver/silver-chloride (Ag/AgCl) electrodes for EEG recording. Nine participants completed an auditory oddball protocol with simultaneous EEG acquisition using both the conventional Ag/AgCl and the wick electrodes. Wick system successfully recorded the expected P300 modulation. Standard ERP analysis, residual random noise analysis, and single-trial analysis of the P300 wave were performed in order to compare signal acquired by both electrodes. It was found that the novel wick electrode performed similarly to the conventional Ag/AgCl electrodes. The developed wick electrode appears to be a reliable alternative for EEG research, representing a promising halfway alternative between wet and dry electrodes. Copyright © 2016 Elsevier B.V. All rights reserved.

Graphene Transparent Conductive Electrodes for Next- Generation Microshutter Arrays

Science.gov (United States)

Li, Mary; Sultana, Mahmooda; Hess, Larry

2012-01-01

Graphene is a single atomic layer of graphite. It is optically transparent and has high electron mobility, and thus has great potential to make transparent conductive electrodes. This invention contributes towards the development of graphene transparent conductive electrodes for next-generation microshutter arrays. The original design for the electrodes of the next generation of microshutters uses indium-tin-oxide (ITO) as the electrode material. ITO is widely used in NASA flight missions. The optical transparency of ITO is limited, and the material is brittle. Also, ITO has been getting more expensive in recent years. The objective of the invention is to develop a graphene transparent conductive electrode that will replace ITO. An exfoliation procedure was developed to make graphene out of graphite crystals. In addition, large areas of single-layer graphene were produced using low-pressure chemical vapor deposition (LPCVD) with high optical transparency. A special graphene transport procedure was developed for transferring graphene from copper substrates to arbitrary substrates. The concept is to grow large-size graphene sheets using the LPCVD system through chemical reaction, transfer the graphene film to a substrate, dope graphene to reduce the sheet resistance, and pattern the film to the dimension of the electrodes in the microshutter array. Graphene transparent conductive electrodes are expected to have a transparency of 97.7%. This covers the electromagnetic spectrum from UV to IR. In comparison, ITO electrodes currently used in microshutter arrays have 85% transparency in mid-IR, and suffer from dramatic transparency drop at a wavelength of near-IR or shorter. Thus, graphene also has potential application as transparent conductive electrodes for Schottky photodiodes in the UV region.

Implicit environmental costs in hydroelectric development

International Nuclear Information System (INIS)

Carlsen, A.J.; Wenstoep, F.; Strand, J.

1992-01-01

The ranking of hydropower projects under the Norwegian Master Plan for Water Resources is used to derive implicit government preferences for a number of environmental attributes described by ordinal scores for each project. Higher negative scores are generally associated with greater implicit willingness to pay to avoid the environmental damage tied to the attribute, caused by hydropower development. The total (ordinary economic and implicit environmental) cost for each project are derived, and the environmental costs per capacity unit are found to be on the same order as the economic costs, lower for projects ranked for early exploitation, and higher for projects to be saved permanently. An implicit long-run marginal cost curve for Norwegian hydropower development is derived, which is generally upward sloping, but not uniformly so. This can be due to the model specification problems or ranking inconsistencies, both of which are likely to be present. 11 refs., 7 figs., 1 tab

Electrochemical reduction of nitroaromatic compounds by single sheet iron oxide coated electrodes

Energy Technology Data Exchange (ETDEWEB)

Huang, Li-Zhi, E-mail: lizhi@plen.ku.dk [Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, DK–1871 Frederiksberg C (Denmark); Hansen, Hans Christian B. [Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, DK–1871 Frederiksberg C (Denmark); Bjerrum, Morten Jannik [Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK–2100 København Ø (Denmark)

2016-04-05

Highlights: • Composite layers of single sheet iron oxides were coated on indium tin oxide electrodes. • Single sheet iron oxide is an electro-catalyst for reduction of nitroaromatic compounds in aqueous solution. • The reduction is well explained by a diffusion layer model. • The charge properties of the nitrophenols have an important influence on reduction. • Low-cost iron oxide based materials are promising electro-catalyst for water treatment. - Abstract: Nitroaromatic compounds are substantial hazard to the environment and to the supply of clean drinking water. We report here the successful reduction of nitroaromatic compounds by use of iron oxide coated electrodes, and demonstrate that single sheet iron oxides formed from layered iron(II)-iron(III) hydroxides have unusual electrocatalytic reactivity. Electrodes were produced by coating of single sheet iron oxides on indium tin oxide electrodes. A reduction current density of 10 to 30 μA cm{sup −2} was observed in stirred aqueous solution at pH 7 with concentrations of 25 to 400 μM of the nitroaromatic compound at a potential of −0.7 V vs. SHE. Fast mass transfer favors the initial reduction of the nitroaromatic compound which is well explained by a diffusion layer model. Reduction was found to comprise two consecutive reactions: a fast four-electron first-order reduction of the nitro-group to the hydroxylamine-intermediate (rate constant = 0.28 h{sup −1}) followed by a slower two-electron zero-order reduction resulting in the final amino product (rate constant = 6.9 μM h{sup −1}). The zero-order of the latter reduction was attributed to saturation of the electrode surface with hydroxylamine-intermediates which have a more negative half-wave potential than the parent compound. For reduction of nitroaromatic compounds, the SSI electrode is found superior to metal electrodes due to low cost and high stability, and superior to carbon-based electrodes in terms of high coulombic efficiency and

Flexible Graphene Electrodes for Prolonged Dynamic ECG Monitoring

Directory of Open Access Journals (Sweden)

Cunguang Lou

2016-11-01

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

A new potentiometric electrode incorporating functionalized β-cyclodextrins for diclofenac determination.

Science.gov (United States)

Lenik, Joanna

2014-12-01

This paper reports the preparation of diclofenac-selective membrane electrodes incorporating β-cyclodextrins: (2-hydroxypropyl)-β-cyclodextrin, heptakis(2,3,6-tri-O-methyl)-β-cyclodextrin, and heptakis(2,3,6-tri-O-benzoyl)-β-cyclodextrin. Several plasticized poly(vinyl chloride) membranes of different compositions were tested with the best electrode being the one incorporating heptakis(2,3,6-tri-O-benzoyl)-β-cyclodextrin with the membrane plasticized with 2-nitrophenyloctyl ether. The electrode is characterized by a near-Nernstian response slope of -60.0 mV decade(-1) over the linear range of 5.0×10(-5)-1.0×10(-2) mol L(-1) and a limit of detection of 1.4×10(-5) mol L(-1). The proposed electrode can easily discriminate diclofenac ions from several inorganic and organic interferents and some common drug excipients. The electrode has a response time of 10s and can be used within a pH range of 6.2-8.5 over 10 months without any considerable deterioration. The electrical properties of the membrane electrode were studied by impedance spectroscopy. The notable advantages of the diclofenac-selective electrode include its high sensitivity, selectivity, cost-effectiveness, and comfortable application in drug and urine analysis. Copyright © 2014 Elsevier B.V. All rights reserved.

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...

Low-Cost Spectral Sensor Development Description.

Energy Technology Data Exchange (ETDEWEB)

Armijo, Kenneth Miguel; Yellowhair, Julius

2014-11-01

Solar spectral data for all parts of the US is limited due in part to the high cost of commercial spectrometers. Solar spectral information is necessary for accurate photovoltaic (PV) performance forecasting, especially for large utility-scale PV installations. A low-cost solar spectral sensor would address the obstacles and needs. In this report, a novel low-cost, discrete- band sensor device, comprised of five narrow-band sensors, is described. The hardware is comprised of commercial-off-the-shelf components to keep the cost low. Data processing algorithms were developed and are being refined for robustness. PV module short-circuit current ( I sc ) prediction methods were developed based on interaction-terms regression methodology and spectrum reconstruction methodology for computing I sc . The results suggest the computed spectrum using the reconstruction method agreed well with the measured spectrum from the wide-band spectrometer (RMS error of 38.2 W/m 2 -nm). Further analysis of computed I sc found a close correspondence of 0.05 A RMS error. The goal is for ubiquitous adoption of the low-cost spectral sensor in solar PV and other applications such as weather forecasting.

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.

Ceramic carbon electrode-based anodes for use in the copper-chlorine thermochemical cycle

International Nuclear Information System (INIS)

Ranganathan, S.; Easton, E.B.

2009-01-01

Sol-gel chemistry is becoming more popular for the synthesis of electrode materials. For example, the sol-gel reaction can be performed in the presence of a carbon black to form a ceramic carbon electrode (CCE). The resultant CCE structure contains electronically conductive carbon particle pathways that are bound together via the ceramic binder, which can also promote ion transport. Furthermore, the CCE structure has a high active surface area and is chemical and thermally robust. We have investigated CCE materials prepared using 3-aminopropyl trimethoxysilane. Electrochemical experiments (cyclic voltammetry, electrochemical impedance spectroscopy) were performed to characterize their suitability as anode electrode materials for use in the electrochemical step of the Cu-Cl thermochemical cycle. Our initial results have shown that CCE-based electrodes vastly outperform a bare carbon electrode, and thus are highly promising and cost-effective electrode material. Subsequent experiments involved the manipulation of the relative ratio of organosilane carbon precursors to gauge its impact on electrode properties and performance. An overview of the materials characterization and electrochemical measurements will be presented. (author)

Ceramic carbon electrode-based anodes for use in the copper-chlorine thermochemical cycle

Energy Technology Data Exchange (ETDEWEB)

Ranganathan, S.; Easton, E.B. [Faculty of Science, Univ. of Ontario Inst. of Technology, Oshawa, Ontario (Canada)], E-mail: ranga@uoit.ca, Brad.Easton@uoit.ca

2009-07-01

Sol-gel chemistry is becoming more popular for the synthesis of electrode materials. For example, the sol-gel reaction can be performed in the presence of a carbon black to form a ceramic carbon electrode (CCE). The resultant CCE structure contains electronically conductive carbon particle pathways that are bound together via the ceramic binder, which can also promote ion transport. Furthermore, the CCE structure has a high active surface area and is chemical and thermally robust. We have investigated CCE materials prepared using 3-aminopropyl trimethoxysilane. Electrochemical experiments (cyclic voltammetry, electrochemical impedance spectroscopy) were performed to characterize their suitability as anode electrode materials for use in the electrochemical step of the Cu-Cl thermochemical cycle. Our initial results have shown that CCE-based electrodes vastly outperform a bare carbon electrode, and thus are highly promising and cost-effective electrode material. Subsequent experiments involved the manipulation of the relative ratio of organosilane carbon precursors to gauge its impact on electrode properties and performance. An overview of the materials characterization and electrochemical measurements will be presented. (author)

Experimental and Theoretical Studies of Nanostructured Electrodes for Use in Dye-Sensitized Solar Cells

Science.gov (United States)

Gong, Jiawei

Among various photovoltaic technologies available in the emerging market, dye-sensitized solar cells (DSSCs) are deemed as an effective, competitive solution to the increasing demand for high-efficiency PV devices. To move towards full commercialization, challenges remain in further improvement of device stability as well as reduction of material and manufacturing costs. This study aims at rational synthesis and photovoltaic characterization of two nanostructured electrode materials (i.e. SnO2 nanofibers and activated graphene nanoplatelets) for use as photoanode and counter electrode in dye-sensitized solar cells. The main objective is to explore the favorable charge transport features of SnO2 nanofiber network and simultaneously replace the high-priced conventional electrocatalytic nanomaterials (e.g. Pt nanoparticles) used in existing counter electrode of DSSCs. To achieve this objective, a multiphysics model of electrode kinetics was developed to optimize various design parameters and cell configurations. The porous hollow SnO2 nanofibers were successfully synthesized via a facile route consisting of electrospinning precursor polymer nanofibers, followed by controlled carbonization. The novel SnO2/TiO2 composite photoanode materials carry advantages of SnO2 nanofiber network (e.g. nanostructural continuity, high electron mobility) and TiO2 nanoparticles (e.g. high specific area), and therefore show excellent photovoltaic properties including improved short-circuit current and fill factors. In addition, hydrothermally activated graphene nanoplatelets (aGNP) were used as a catalytic counter electrode material to substitute for conventionally used platinum nanoparticles. Improved catalytic performance of aGNP electrode was achieved through increased surface area and better control of morphology. Dye-sensitized solar cells using these aGNP electrodes had power conversion efficiencies comparable to those using platinum nanoparticles with I-/I3- redox mediators

Cathodic electrogenerated chemiluminescence of aromatic Tb(III) chelates at polystyrene-graphite composite electrodes

International Nuclear Information System (INIS)

Salminen, Kalle; Grönroos, Päivi; Tuomi, Sami; Kulmala, Sakari

2017-01-01

Tb(III) chelates exhibit intense hot electron-induced electrogenerated chemiluminescence during cathodic polarization of metal/polystyrene-graphite (M/PG) electrodes in fully aqueous solutions. The M/PG working electrode provides a sensitive means for the determination of aromatic Tb(III) chelates at nanomolar concentration levels with a linear log-log calibration curve spanning more than five orders of magnitude. The charge transport and other properties of these novel electrodes were studied by electrochemiluminescence measurements and cyclic voltammetry. The present composite electrodes can by utilized both under pulse polarization and DC polarization unlike oxide-coated metal electrodes which do not tolerate cathodic DC polarization. The present cost-effective electrodes could be utilized e.g. in immunoassays where polystyrene is extensively used as a solid phase for various bioaffinity assays by using electrochemiluminescent Tb(III) chelates or e.g. Ru(bpy) 3 2+ as labels. - Highlights: • Generation of hydrated electrons at Polystyrene-graphite electrodes. • The insulating polystyrene layer on the outer electrode surface seems necessary. • Hydrated electrons are able to produce chemiluminescence. • Strongest signal and lowest std. dev. achieved at same graphite weight fraction.

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.

Electrochemical determination of cadmium and lead on pristine single-walled carbon nanotube electrodes.

Science.gov (United States)

Bui, Minh-Phuong Ngoc; Li, Cheng Ai; Han, Kwi Nam; Pham, Xuan-Hung; Seong, Gi Hun

2012-01-01

A flexible, transparent, single-walled carbon nanotube (SWCNT) film electrode was prepared by vacuum filtering methods, followed by photolithographic patterning of a photoresist polymer on the SWCNT surface. The morphology of the SWCNT film electrode surface was characterized using a field-emission scanning electron microscope coupled to an energy-dispersive X-ray spectrophotometer. The electrodes were successfully used as a mercury-free electrochemical sensor for individual and simultaneous detection of cadmium (Cd(2+)) and lead (Pb(2+)) in 0.02 M HCl by square-wave stripping voltammetry. Some important operational parameters, including deposition time, deposition potential, square-wave amplitude, and square wave-frequency were optimized for the detection of Cd(2+) and Pb(2+). The newly developed sensor showed good linear behavior in the examined concentration. For individual Cd(2+) and Pb(2+) ion detection, the linear range was found from 0.033 to 0.228 ppm with detection limits of 0.7 ppb (R(2) = 0.985) for Cd(2+) and 0.8 ppb (R(2) = 0.999) for Pb(2+). For simultaneous detection, the linear range was found from 0.033 to 0.280 ppm with a limit of detection of 2.2 ppb (R(2) = 0.976) and 0.6 ppb (R(2) = 0.996) for Cd(2+) and Pb(2+), respectively. SWCNT film electrodes offered favorable reproducibility of ± 5.4% and 4.3% for Cd(2+) and Pb(2+), respectively. The experiments demonstrated the applicability of carbon nanotubes, specifically in the preparation of SWCNT films. The results suggest that the proposed flexible SWCNT film electrodes can be applied as simple, efficient, cost-effective, and/or disposable electrodes for simultaneous detection of heavy metal ions.

Towards low cost, efficient and stable organic photovoltaic modules

NARCIS (Netherlands)

Andriessen, H.A.J.M.; Galagan, Y.O.; Rubingh, J.E.J.M.; Grossiord, N.; Blom, P.W.M.; Kroon, J.; Veenstra, S.; Verhees, W.; Slooff, L.; Pex, P.

2010-01-01

The presence of a transparent conductive electrode such as indium tin oxide (ITO) limits the reliability and cost price of organic photovoltaic devices as it is brittle and expensive. Moreover, the relative high sheet resistance of an ITO electrode on flexible substrates limits the maximum width of

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.

Optimizing areal capacities through understanding the limitations of lithium-ion electrodes

Energy Technology Data Exchange (ETDEWEB)

Gallagher, Kevin G.; Trask, Stephen E.; Bauer, Christoph; Woehrle, Thomas; Lux, Simon; Tschech, Matthias; Polzin, Bryant J.; Ha, Seungbum; Long, Brandon R.; Wu, Qingliu; Lu, Wenquan; Dees, Dennis W.; Jansen, Andrew N.

2016-01-01

Increasing the areal capacity or electrode thickness in lithium ion batteries is one possible means to increase pack level energy density while simultaneously lowering cost. The physics that limit use of high areal capacity as a function of battery power to energy ratio are poorly understood and thus most currently produced automotive lithium ion cells utilize modest loadings to ensure long life over the vehicle battery operation. Here we show electrolyte transport limits the utilization of the positive electrode at critical C-rates during discharge; whereas, a combination of electrolyte transport and polarization lead to lithium plating in the graphite electrode during charge. Experimental measurements are compared with theoretical predictions based on concentrated solution and porous electrode theories. An analytical expression is derived to provide design criteria for long lived operation based on the physical properties of the electrode and electrolyte. Finally, a guideline is proposed that graphite cells should avoid charge current densities near or above 4 mA/cm2 unless additional precautions have been made to avoid deleterious side reaction.

Distribution of Costs and Profits in Urban Development

DEFF Research Database (Denmark)

Christensen, Finn Kjær; Sørensen, Michael Tophøj

2009-01-01

Most countries have a system - procedures and tools - for foreseeable, clear and fair distribution of costs and profits in urban development. However, the distribution of profits and costs between the municipality and the developers /landowners is in Denmark rather fragmented and not very...... transparent as the distribution is regulated throughout the whole planning and environmental regulation system. Furthermore, development agreements – an “old” tool in many countries and an efficient tool to distribute profits and costs between the public and private sector – have only recently become possible...... in Denmark, and only under some special circumstances. This paper aims to clarify how costs and profits are distributed between the municipality and the developers /landowners in Denmark. The paper analyses how the Danish planning and environmental regulation system handles this issue. Based on the analysis...

New electrodes for hydrogen/oxygen solid polymer electrolyte fuel cell

Energy Technology Data Exchange (ETDEWEB)

Mosdale, R [CEA Centre d` Etudes de Grenoble, 38 (France). Dept. de Recherche Fondamentale sur la Matiere Condensee; Stevens, P [CEA Centre d` Etudes de Grenoble, 38 (France). Dept. de Thermohydraulique et de Physique

1993-12-31

A new method of preparation of Electrode/Membrane/Electrode (EME) assemblies for Proton Exchange Membrane Fuel Cells (PEMFC) has been developed. The electrodes are deposited directly onto a Nafion electrolyte membrane from a mixture of platinized carbon, Nafion solution, and PTFE by using a spray technique. By this technique, porous electrodes are obtained with an optimized gas/electrolyte/catalyst interface, and electrode/membrane interface.

Guidelines for cost control and analysis of cost-type research and development contracts

Science.gov (United States)

Sibbers, C. W.

1981-01-01

The cost information which should be obtained from a contractor(s) on a major, cost type research and development contract(s), and the analyses and effective use of these data are discussed. Specific type(s) of information which should be required, methods for analyzing such information, and methods for effectively using the results of such analyses to enhance NASA contract and project management are included. The material presented is based primarily on the principal methods which have been effectively used in the management of major cost type research and development contracts.

Low-cost and disposable sensors for the simultaneous determination of coenzyme Q10 and α-lipoic acid using manganese (IV) oxide-modified screen-printed graphene electrodes.

Science.gov (United States)

Charoenkitamorn, Kanokwan; Chaiyo, Sudkate; Chailapakul, Orawon; Siangproh, Weena

2018-04-03

In this work, for the first time, manganese (IV) oxide-modified screen-printed graphene electrodes (MnO 2 /SPGEs) were developed for the simultaneous electrochemical detection of coenzyme Q10 (CoQ10) and α-lipoic acid (ALA). This sensor exhibits attractive benefits such as simplicity, low production costs, and disposability. Cyclic voltammetry (CV) was used to characterize the electrochemical behavior of the analyte and investigate the capacitance and electroactive surface area of the unmodified and modified electrode surfaces. The electrochemical behavior of CoQ10 and ALA on MnO 2 /SPGEs was also discussed. Additionally, square wave anodic stripping voltammetry (SWASV) was used for the quantitative determination of CoQ10 and ALA. Under optimal conditions, the obtained signals are linear in the concentration range from 2.0 to 75.0 μg mL -1 for CoQ10 and 0.3-25.0 μg mL -1 for ALA. The low limits of detection (LODs) were found to be 0.56 μg mL -1 and 0.088 μg mL -1 for CoQ10 and ALA, respectively. Moreover, we demonstrated the utility and applicability of the MnO 2 /SPGE sensor through simultaneous measurements of CoQ10 and ALA in dietary supplements. The sensor provides high accuracy measurements, exhibiting its high potential for practical applications. Copyright © 2017 Elsevier B.V. All rights reserved.

A Donor-Supply Electrode (DSE) for Colloidal Quantum Dot Photovoltaics

KAUST Repository

Koleilat, Ghada I.

2011-12-14

The highest-performing colloidal quantum dot (CQD) photovoltaics (PV) reported to date have relied on high-temperature (>500°C) annealing of electron-accepting TiO 2. Room-temperature processing reduces energy payback time and manufacturing cost, enables flexible substrates, and permits tandem solar cells that integrate a small-bandgap back cell atop a low-thermal-budget larger-bandgap front cell. Here we report an electrode strategy that enables a depleted-heterojunction CQD PV device to be fabricated entirely at room temperature. We find that simply replacing the high-temperature-processed TiO 2 with a sputtered version of the same material leads to poor performance due to the low mobility of the sputtered oxide. We develop instead a two-layer donor-supply electrode (DSE) in which a highly doped, shallow work function layer supplies a high density of free electrons to an ultrathin TiO 2 layer via charge-transfer doping. Using the DSE we build all-room-temperature-processed small-bandgap (1 eV) colloidal quantum dot solar cells having 4% solar power conversion efficiency and high fill factor. These 1 eV bandgap cells are suitable for use as the back junction in tandem solar cells. The DSE concept, combined with control over TiO 2 stoichiometry in sputtering, provides a much-needed tunable electrode to pair with quantum-size-effect CQD films. © 2011 American Chemical Society.

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

Electro activation of persulfate using iron sheet as low-cost electrode: the role of the operating conditions.

Science.gov (United States)

Silveira, Jefferson E; Cardoso, Tais O; Barreto-Rodrigues, Marcio; Zazo, Juan A; Casas, José A

2018-05-01

This work assesses the role of the operational conditions upon the electro-activation of persulfate (PS) using sacrificed iron electrode as a continuous low-cost Fe 2+ source. An aqueous phenol solution (100 mg L -1 ) was selected as model effluent. The studied variables include current density (1-10 mA cm -2 ), persulfate concentration (0.7-2.85 g L -1 ), temperature (30-90°C) and the solution conductivity (2.7-20.7 mS cm -1 ) using Na 2 SO 4 and NaCl as supporting electrolyte. A mineralization degree of around 80% with Na 2 SO 4 and 92% in presence of NaCl was achieved at 30°C using 2.15 g L -1 PS at the lowest current density tested (1 mA cm -2 ). Besides PS concentration, temperature was the main variable affecting the process. In the range of 30-70°C, it showed a positive effect, achieving TOC conversion above 95% (using Na 2 SO 4 under the previous conditions) along with a significant increase in iron sludge, which adversely affects the economy of the process. A lumped and simplified kinetic model based on persulfate consumption and TOC mineralization is suggested. The activation energy obtained for the TOC decay was 29 kJ mol -1 . An estimated operating cost of US$ 3.00 per m 3 was obtained, demonstrating the economic feasibility of this process.

Development of gas ionization chambers with coplanar electrodes for alpha-ray spectrometry

International Nuclear Information System (INIS)

Iwasaki, Kenta; Tanaka, Naomichi; Murakami, Kohei; Hasebe, Nobuyuki; Kusano, Hiroki; Shibamura, Eido; Miyajima, Mitsuhiro

2016-01-01

A large-area alpha-ray spectrometer is required to measure the low level alpha emitters in environmental samples, which may be distributed in the vicinity of nuclear power plants. A gas ionization chamber with a coplanar electrode has attractive features such as with mechanical ruggedness, easy handling, easy fabrication of large electrode, and relatively well-known performance. We have investigated the performance of a gas ionization chamber with a coplanar electrode for alpha-ray spectrometry, particularly in the energy resolution. The present experiment shows that the energy resolution in the full width at half maximum (FWHM) is 129 keV (= 2.7%) for alpha-rays from Np with an energy of 4.78 MeV, 120 keV (= 2.2%) for those with 5.49 MeV from Am, and 109 keV (= 1.9%) for those with 5.81 MeV from Cm. It is found that the energy resolution obtained at the present experiment is dominated in the electronic noise caused by the large capacitance existed between the collecting anode (CA) and non-collecting anode (NCA) in the coplanar electrode. (author)

Buried MoO x/Ag Electrode Enables High-Efficiency Organic/Silicon Heterojunction Solar Cells with a High Fill Factor.

Science.gov (United States)

Xia, Zhouhui; Gao, Peng; Sun, Teng; Wu, Haihua; Tan, Yeshu; Song, Tao; Lee, Shuit-Tong; Sun, Baoquan

2018-04-25

Silicon (Si)/organic heterojunction solar cells based on poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) and n-type Si have attracted wide interests because they promise cost-effectiveness and high-efficiency. However, the limited conductivity of PEDOT:PSS leads to an inefficient hole transport efficiency for the heterojunction device. Therefore, a high dense top-contact metal grid electrode is required to assure the efficient charge collection efficiency. Unfortunately, the large metal grid coverage ratio electrode would lead to undesirable optical loss. Here, we develop a strategy to balance PEDOT:PSS conductivity and grid optical transmittance via a buried molybdenum oxide/silver grid electrode. In addition, the grid electrode coverage ratio is optimized to reduce its light shading effect. The buried electrode dramatically reduces the device series resistance, which leads to a higher fill factor (FF). With the optimized buried electrode, a record FF of 80% is achieved for flat Si/PEDOT:PSS heterojunction devices. With further enhancement adhesion between the PEDOT:PSS film and Si substrate by a chemical cross-linkable silance, a power conversion efficiency of 16.3% for organic/textured Si heterojunction devices is achieved. Our results provide a path to overcome the inferior organic semiconductor property to enhance the organic/Si heterojunction solar cell.

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.

Results of the LIRES Round Robin test on high temperature reference electrodes for LWR applications

Energy Technology Data Exchange (ETDEWEB)

Bosch, R.W. [SCK.CEN, Nuclear Research Centre Belgium, Boeretang 200, B-2400 Mol (Belgium); Nagy, G. [Magyar Tudomanyos Akademia KFKI Atomenergia Kutatointezet, AEKI, Konkoly Thege ut 29-33, 1121 Budapest (Hungary); Feron, D. [CEA Saclay, 91191 Gif-Sur-Yvette Cedex (France); Navas, M. [CIEMAT, Edificio 30, Dpto. Fision Nuclear, Avda. Complutense 22, 28040 Madrid, (Spain); Bogaerts, W. [KU Leuven, Kasteelpark Arenberg 31, B-3001 Leuven (Belgium); Karnik, D. [Nuclear Research Institute, NRI, Rez (Czech Republic); Dorsch, T. [Framatone ANP, Inc., Charlotte, North Carolina (United States); Molander, A. [Studsvik AB SE-611 82 Nykoeping (Sweden); Maekelae, K. [Materials and Structural Integrity, VTT Technical Research Centre of Finland, Kemistintie 3, P.O. Box 1704, FIN-02044 VTT (Finland)

2004-07-01

A European sponsored research project has been started on 1 October 2000 to develop high temperature reference electrodes that can be used for in-core electrochemical measurements in Light Water Reactors (LWR's). This LIRES-project (Development of Light Water Reactor Reference Electrodes) consists of 9 partners (SCK-CEN, AEKI, CEA, CIEMAT, KU Leuven, NRI Rez, Framatone ANP, Studsvik Nuclear and VTT) and will last for four years. The main objective of this LIRES project is to develop a reference electrode, which is robust enough to be used inside a LWR. Emphasize is put on the radiation hardness of both the mechanical design of the electrode as the proper functioning of the electrode. A four steps development trajectory is foreseen: (1) To set a testing standard for a Round Robin, (2) To develop different reference electrodes, (3) To perform a Round Robin test of these reference electrodes followed by selection of the best reference electrode(s), (4) To perform irradiation tests under appropriate LWR conditions in a Material Test Reactor (MTR). Four different high temperature reference electrodes have been developed and are being tested in a Round Robin test. These electrodes are: A Ceramic Membrane Electrode (CME), a Rhodium electrode, an external Ag/AgCl electrode and a Palladium electrode. The presentation will focus on the results obtained with the Round Robin test. (authors)

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...

Detection of Antibiotics and Evaluation of Antibacterial Activity with Screen-Printed Electrodes

Directory of Open Access Journals (Sweden)

Florentina-Daniela Munteanu

2018-03-01

Full Text Available This review provides a brief overview of the fabrication and properties of screen-printed electrodes and details the different opportunities to apply them for the detection of antibiotics, detection of bacteria and antibiotic susceptibility. Among the alternative approaches to costly chromatographic or ELISA methods for antibiotics detection and to lengthy culture methods for bacteria detection, electrochemical biosensors based on screen-printed electrodes present some distinctive advantages. Chemical and (biosensors for the detection of antibiotics and assays coupling detection with screen-printed electrodes with immunomagnetic separation are described. With regards to detection of bacteria, the emphasis is placed on applications targeting viable bacterial cells. While the electrochemical sensors and biosensors face many challenges before replacing standard analysis methods, the potential of screen-printed electrodes is increasingly exploited and more applications are anticipated to advance towards commercial analytical tools.

Development of high-performance supercapacitor electrode derived from sugar industry spent wash waste.

Science.gov (United States)

Mahto, Ashesh; Gupta, Rajeev; Ghara, Krishna Kanta; Srivastava, Divesh N; Maiti, Pratyush; D, Kalpana; Rivera, Paul-Zavala; Meena, R; Nataraj, S K

2017-10-15

This study aims at developing supercapacitor materials from sugar and distillery industry wastes, thereby mediating waste disposal problem through reuse. In a two-step process, biomethanated spent wash (BMSW) was acid treated to produce solid waste sludge and waste water with significantly reduced total organic carbon (TOC) and biological oxygen demand (BOD) content. Further, waste sludge was directly calcined in presence of activating agent ZnCl 2 in inert atmosphere resulting in high surface area (730-900m 2 g -1 ) carbon of unique hexagonal morphology. Present technique resulted in achieving two-faceted target of liquid-solid waste remediation and production of high-performance carbon material. The resulted high surface area carbon was tested in both three and two electrode systems. Electrochemical tests viz. cyclic voltammetry, galvanostatic charge-discharge and impedance measurement were carried out in aqueous KOH electrolyte yielding specific capacitance as high as 120Fg -1 , whereas all solid supercapacitor devised using PVA/H 3 PO 4 polyelectrolyte showed stable capacitance of 105Fg -1 at 0.2Ag -1 . The presence of transition metal particles and hetero-atoms on carbon surface were confirmed by XPS, EDX and TEM analysis which enhanced the conductivity and imparted pseudocapacitance to some extent into the working electrode. The present study successfully demonstrated production of high-performance electrode material from dirtiest wastewater making process green, sustainable and economically viable. Copyright © 2017. Published by Elsevier B.V.

Manganese oxide-based materials as electrochemical supercapacitor electrodes.

Science.gov (United States)

Wei, Weifeng; Cui, Xinwei; Chen, Weixing; Ivey, Douglas G

2011-03-01

Electrochemical supercapacitors (ECs), characteristic of high power and reasonably high energy densities, have become a versatile solution to various emerging energy applications. This critical review describes some materials science aspects on manganese oxide-based materials for these applications, primarily including the strategic design and fabrication of these electrode materials. Nanostructurization, chemical modification and incorporation with high surface area, conductive nanoarchitectures are the three major strategies in the development of high-performance manganese oxide-based electrodes for EC applications. Numerous works reviewed herein have shown enhanced electrochemical performance in the manganese oxide-based electrode materials. However, many fundamental questions remain unanswered, particularly with respect to characterization and understanding of electron transfer and atomic transport of the electrochemical interface processes within the manganese oxide-based electrodes. In order to fully exploit the potential of manganese oxide-based electrode materials, an unambiguous appreciation of these basic questions and optimization of synthesis parameters and material properties are critical for the further development of EC devices (233 references).

A novel paper-based device coupled with a silver nanoparticle-modified boron-doped diamond electrode for cholesterol detection

Energy Technology Data Exchange (ETDEWEB)

Nantaphol, Siriwan [Electrochemistry and Optical Spectroscopy Research Unit, Department of Chemistry, Faculty of Science, Chulalongkorn University, 254 Phayathai Road, Pathumwan, Bangkok 10330 (Thailand); Chailapakul, Orawon, E-mail: corawon@chula.ac.th [Electrochemistry and Optical Spectroscopy Research Unit, Department of Chemistry, Faculty of Science, Chulalongkorn University, 254 Phayathai Road, Pathumwan, Bangkok 10330 (Thailand); Center for Petroleum, Petrochemicals and Advanced Materials, Chulalongkorn University, 254 Phayathai Road, Pathumwan, Bangkok 10330 (Thailand); Siangproh, Weena, E-mail: weenasi@hotmail.com [Department of Chemistry, Faculty of Science, Srinakharinwirot University, Sukhumvit 23, Wattanna, Bangkok 10110 (Thailand)

2015-09-03

A novel paper-based analytical device (PAD) coupled with a silver nanoparticle-modified boron-doped diamond (AgNP/BDD) electrode was first developed as a cholesterol sensor. The AgNP/BDD electrode was used as working electrode after modification by AgNPs using an electrodeposition method. Wax printing was used to define the hydrophilic and hydrophobic areas on filter paper, and then counter and reference electrodes were fabricated on the hydrophilic area by screen-printing in house. For the amperometric detection, cholesterol and cholesterol oxidase (ChOx) were directly drop-cast onto the hydrophilic area, and H{sub 2}O{sub 2} produced from the enzymatic reaction was monitored. The fabricated device demonstrated a good linearity (0.39 mg dL{sup −1} to 270.69 mg dL{sup −1}), low detection limit (0.25 mg dL{sup −1}), and high sensitivity (49.61 μA mM{sup −1} cm{sup −2}). The precision value for ten replicates was 3.76% RSD for 1 mM H{sub 2}O{sub 2}. In addition, this biosensor exhibited very high selectivity for cholesterol detection and excellent recoveries for bovine serum analysis (in the range of 99.6–100.8%). The results showed that this new sensing platform will be an alternative tool for cholesterol detection in routine diagnosis and offers the advantages of low sample/reagent consumption, low cost, portability, and short analysis time. - Highlights: • Novel PAD coupled with AgNP/BDDE for cholesterol determination was developed. • Wide linear range, low detection limit and high selectivity were achieved. • This sensor was successfully applied for cholesterol determination in bovine serum. • This platform offers the advantages of low sample/reagent consumption and low cost.

A novel paper-based device coupled with a silver nanoparticle-modified boron-doped diamond electrode for cholesterol detection

International Nuclear Information System (INIS)

Nantaphol, Siriwan; Chailapakul, Orawon; Siangproh, Weena

2015-01-01

A novel paper-based analytical device (PAD) coupled with a silver nanoparticle-modified boron-doped diamond (AgNP/BDD) electrode was first developed as a cholesterol sensor. The AgNP/BDD electrode was used as working electrode after modification by AgNPs using an electrodeposition method. Wax printing was used to define the hydrophilic and hydrophobic areas on filter paper, and then counter and reference electrodes were fabricated on the hydrophilic area by screen-printing in house. For the amperometric detection, cholesterol and cholesterol oxidase (ChOx) were directly drop-cast onto the hydrophilic area, and H 2 O 2 produced from the enzymatic reaction was monitored. The fabricated device demonstrated a good linearity (0.39 mg dL −1 to 270.69 mg dL −1 ), low detection limit (0.25 mg dL −1 ), and high sensitivity (49.61 μA mM −1  cm −2 ). The precision value for ten replicates was 3.76% RSD for 1 mM H 2 O 2 . In addition, this biosensor exhibited very high selectivity for cholesterol detection and excellent recoveries for bovine serum analysis (in the range of 99.6–100.8%). The results showed that this new sensing platform will be an alternative tool for cholesterol detection in routine diagnosis and offers the advantages of low sample/reagent consumption, low cost, portability, and short analysis time. - Highlights: • Novel PAD coupled with AgNP/BDDE for cholesterol determination was developed. • Wide linear range, low detection limit and high selectivity were achieved. • This sensor was successfully applied for cholesterol determination in bovine serum. • This platform offers the advantages of low sample/reagent consumption and low cost.

Improving Probe Immobilization for Label-Free Capacitive Detection of DNA Hybridization on Microfabricated Gold Electrodes

Directory of Open Access Journals (Sweden)

Sandro Carrara

2008-02-01

Full Text Available Alternative approaches to labeled optical detection for DNA arrays are actively investigated for low-cost point-of-care applications. In this domain, label-free capacitive detection is one of the most intensely studied techniques. It is based on the idea to detect the Helmholtz ion layer displacements when molecular recognition occurs at the electrodes/solution interface. The sensing layer is usually prepared by using thiols terminated DNA single-strength oligonucleotide probes on top of the sensor electrodes. However, published data shows evident time drift, which greatly complicates signal conditioning and processing and ultimately increases the uncertainty in DNA recognition sensing. The aim of this work is to show that newly developed ethylene-glycol functionalized alkanethiols greatly reduce time drift, thereby significantly improving capacitance based label-free detection of DNA.

Sensitive Adsorptive Voltammetric Method for Determination of Bisphenol A by Gold Nanoparticle/Polyvinylpyrrolidone-Modified Pencil Graphite Electrode

Directory of Open Access Journals (Sweden)

Yesim Tugce Yaman

2016-05-01

Full Text Available A novel electrochemical sensor gold nanoparticle (AuNP/polyvinylpyrrolidone (PVP modified pencil graphite electrode (PGE was developed for the ultrasensitive determination of Bisphenol A (BPA. The gold nanoparticles were electrodeposited by constant potential electrolysis and PVP was attached by passive adsorption onto the electrode surface. The electrode surfaces were characterized by electrochemical impedance spectroscopy (EIS and scanning electron microscopy (SEM. The parameters that affected the experimental conditions were researched and optimized. The AuNP/PVP/PGE sensor provided high sensitivity and selectivity for BPA recognition by using square wave adsorptive stripping voltammetry (SWAdSV. Under optimized conditions, the detection limit was found to be 1.0 nM. This new sensor system offered the advantages of simple fabrication which aided the expeditious replication, low cost, fast response, high sensitivity and low background current for BPA. This new sensor system was successfully tested for the detection of the amount of BPA in bottled drinking water with high reliability.

A new electrode design for ambipolar injection in organic semiconductors.

Science.gov (United States)

Kanagasekaran, Thangavel; Shimotani, Hidekazu; Shimizu, Ryota; Hitosugi, Taro; Tanigaki, Katsumi

2017-10-17

Organic semiconductors have attracted much attention for low-cost, flexible and human-friendly optoelectronics. However, achieving high electron-injection efficiency is difficult from air-stable electrodes and cannot be equivalent to that of holes. Here, we present a novel concept of electrode composed of a bilayer of tetratetracontane (TTC) and polycrystalline organic semiconductors (pc-OSC) covered by a metal layer. Field-effect transistors of single-crystal organic semiconductors with the new electrodes of M/pc-OSC/TTC (M: Ca or Au) show both highly efficient electron and hole injection. Contact resistance for electron injection from Au/pc-OSC/TTC and hole injection from Ca/pc-OSC/TTC are comparable to those for electron injection from Ca and hole injection from Au, respectively. Furthermore, the highest field-effect mobilities of holes (22 cm 2  V -1  s -1 ) and electrons (5.0 cm 2  V -1  s -1 ) are observed in rubrene among field-effect transistors with electrodes so far proposed by employing Ca/pc-OSC/TTC and Au/pc-OSC/TTC electrodes for electron and hole injection, respectively.One of technological challenges building organic electronics is efficient injection of electrons at metal-semiconductor interfaces compared to that of holes. The authors show an air-stable electrode design with induced gap states, which support Fermi level pinning and thus ambipolar carrier injection.

Synthesis on construction unit cost development : technical report.

Science.gov (United States)

2009-01-01

Availability of historical unit cost data is an important factor in developing accurate project cost estimates. : State highway agencies (SHAs) collect data on historical bids and/or production rates, crew sizes and mixes, : material costs, and equip...

Organic light-emitting diodes using novel embedded al gird transparent electrodes

Science.gov (United States)

Peng, Cuiyun; Chen, Changbo; Guo, Kunping; Tian, Zhenghao; Zhu, Wenqing; Xu, Tao; Wei, Bin

2017-03-01

This work demonstrates a novel transparent electrode using embedded Al grids fabricated by a simple and cost-effective approach using photolithography and wet etching. The optical and electrical properties of Al grids versus grid geometry have been systematically investigated, it was found that Al grids exhibited a low sheet resistance of 70 Ω □-1 and a light transmission of 69% at 550 nm with advantages in terms of processing conditions and material cost as well as potential to large scale fabrication. Indium Tin Oxide-free green organic light-emitting diodes (OLED) based on Al grids transparent electrodes was demonstrated, yielding a power efficiency >15 lm W-1 and current efficiency >39 cd A-1 at a brightness of 2396 cd m-2. Furthermore, a reduced efficiency roll-off and higher brightness have been achieved compared with ITO-base device.

A paper-based electrode using a graphene dot/PEDOT:PSS composite for flexible solar cells

KAUST Repository

Lee, Chuan-Pei

2017-04-22

We have synthesized a metal-free composite ink that contains graphene dots (GDs) and poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) that can be used on paper to serve as the counter electrode in a flexible dye-sensitized solar cell (DSSC). This paper-based GD/PEDOT:PSS electrode is low-cost, light-weight, flexible, environmentally friendly, and easy to cut and process for device fabrication. We determined the GD/PEDOT:PSS composite effectively fills the dense micro-pores in the paper substrate, which leads to improved carrier transport in the electrode and a 3-fold enhanced cell efficiency as compared to the paper electrode made with sputtered Pt. Moreover, the DSSC with the paper electrode featuring the GD/PEDOT:PSS composite did not fail in photovoltaic tests even after bending the electrode 150 times, whereas the device made with the Pt-based paper electrode decreased in efficiency by 45% after such manipulation. These exceptional properties make the metal-free GD/PEDOT:PSS composite ink a promising electrode material for a wide variety of flexible electronic applications.

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.

Data on treatment of sewage wastewater by electrocoagulation using punched aluminum electrode and characterization of generated sludge

Directory of Open Access Journals (Sweden)

Vinita Khandegar

2018-06-01

Full Text Available The electrocoagulation setup must be optimized in order to design an economically feasible process. Therefore, in this work, the effect of the punched aluminum electrode on the performance of the electrocoagulation (EC has been investigated. A series of experiments were performed for treatment of sewage wastewater using plane electrode and compare with punched electrodes. Effect of contact time, voltage, electrode spacing and stirring speed has been optimized for removal of Biochemical oxygen demand (BOD and Total dissolved solids (TDS. It was observed that the performance of electrocoagulation process increased using punched electrode. Also, the less operating cost noticed in punched electrode as compared to a plane electrode for (70–80% removal of BOD and TDS. These data would be useful in designing of an EC reactor to obtain high removal efficiency at low energy consumption. Keywords: Electrocoagulation, Sewage wastewater, Aluminum, Plane, Punched electrode

A Microbeam Resonator with Partial Electrodes for Logic and Memory Elements

KAUST Repository

Hafiz, Md Abdullah Al

2017-11-10

We demonstrate logic and memory elements based on an in-plane clamped-clamped microbeam resonator. The micro-resonator is electrostatically actuated through a drive electrode and the motional signal is capacitively sensed at a sense electrode, while the resonance characteristics are modulated by DC voltage pulses provided at two separate partial electrodes, independent of the drive/sense electrodes. For the logic applications, we use two separate electrodes to provide DC voltages defined as the logic inputs. The high (low) motional signal at on-resonance (off-resonance) state is defined as the logic output state “1” (“0”). For the memory operation, two stable vibrational states, high and low, within the hysteretic regime are defined as the memory states, “1” and “0”, respectively. We take advantage of the split electrode configuration to provide positive and negative DC voltage pulses selectively to set/reset the memory states (“1”/“0”) without affecting the driving and sensing terminals. Excluding the energy cost for supporting electronics, these devices consume energy in 10’s of picojoules per logic/memory operations. Furthermore, the devices are fabricated using silicon on insulator (SOI) wafers, have the potential for on-chip integration, and operate at moderate pressure (~1 Torr) and room temperature.

A Microbeam Resonator with Partial Electrodes for Logic and Memory Elements

KAUST Repository

Hafiz, Md Abdullah Al; Ilyas, Saad; Ahmed, Sally; Younis, Mohammad I.; Fariborzi, Hossein

2017-01-01

We demonstrate logic and memory elements based on an in-plane clamped-clamped microbeam resonator. The micro-resonator is electrostatically actuated through a drive electrode and the motional signal is capacitively sensed at a sense electrode, while the resonance characteristics are modulated by DC voltage pulses provided at two separate partial electrodes, independent of the drive/sense electrodes. For the logic applications, we use two separate electrodes to provide DC voltages defined as the logic inputs. The high (low) motional signal at on-resonance (off-resonance) state is defined as the logic output state “1” (“0”). For the memory operation, two stable vibrational states, high and low, within the hysteretic regime are defined as the memory states, “1” and “0”, respectively. We take advantage of the split electrode configuration to provide positive and negative DC voltage pulses selectively to set/reset the memory states (“1”/“0”) without affecting the driving and sensing terminals. Excluding the energy cost for supporting electronics, these devices consume energy in 10’s of picojoules per logic/memory operations. Furthermore, the devices are fabricated using silicon on insulator (SOI) wafers, have the potential for on-chip integration, and operate at moderate pressure (~1 Torr) and room temperature.

Development of Low-Cost DDGS-Based Activated Carbons and Their Applications in Environmental Remediation and High-Performance Electrodes for Supercapacitors

KAUST Repository

Wang, Yong

2015-08-28

Abstract: A one-step, facile method to produce 3-dimensional porous activated carbons (ACs) from corn residual dried distillers grains with solubles (DDGS) by microwave-assisted chemical activation was developed. The ACs’ application potentials in dye removal and supercapacitor electrodes were also demonstrated. The porous structure and surface properties of the ACs were characterized by N2 adsorption/desorption isotherms and scanning electron microscopy. The results showed that the surface area of the as-prepared ACs was up to 1000 m2/g. In the dye removal tests, these DDGS-based ACs exhibited a maximum adsorption ratio of 477 mg/g on methylene blue. In electric double layer capacitors, electrochemical tests indicated that the ACs had ideal capacitive and reversible behaviors and exhibited excellent electrochemical performance. The specific capacitance varied between 120 and 210 F/g under different scan rates and current densities. In addition, the capacitors showed excellent stability even after one thousand charge–discharge cycles. The specific capacitance was further increased up to 300 F/g by in situ synthesis of MnO2 particles in the ACs to induce pseudo-capacitance. This research showed that the DDGS-based ACs had great potentials in environmental remediation and energy storage applications. Graphical Abstract: [Figure not available: see fulltext.] © 2015 Springer Science+Business Media New York

A survey of reference electrodes for high temperature waters; Oeversikt av referenselektroder i hoegtemperaturvatten

Energy Technology Data Exchange (ETDEWEB)

Molander, A.; Eriksson, Sture; Pein, K. [Studsvik Nuclear, Nykoeping (Sweden)

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

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

Directory of Open Access Journals (Sweden)

C. Mathalai Sundaram

2014-12-01

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

Electrospun Metal Nanofiber Webs as High-Performance Transparent Electrode

KAUST Repository

Wu, Hui

2010-10-13

Transparent electrodes, indespensible in displays and solar cells, are currently dominated by indium tin oxide (ITO) films although the high price of indium, brittleness of films, and high vacuum deposition are limiting their applications. Recently, solution-processed networks of nanostructures such as carbon nanotubes (CNTs), graphene, and silver nanowires have attracted great attention as replacements. A low junction resistance between nanostructures is important for decreasing the sheet resistance. However, the junction resistances between CNTs and boundry resistances between graphene nanostructures are too high. The aspect ratios of silver nanowires are limited to ∼100, and silver is relatively expensive. Here, we show high-performance transparent electrodes with copper nanofiber networks by a low-cost and scalable electrospinning process. Copper nanofibers have ultrahigh aspect ratios of up to 100000 and fused crossing points with ultralow junction resistances, which result in high transmitance at low sheet resistance, e.g., 90% at 50 Ω/sq. The copper nanofiber networks also show great flexibility and stretchabilty. Organic solar cells using copper nanowire networks as transparent electrodes have a power efficiency of 3.0%, comparable to devices made with ITO electrodes. © 2010 American Chemical Society.

Electrospun Metal Nanofiber Webs as High-Performance Transparent Electrode

KAUST Repository

Wu, Hui; Hu, Liangbing; Rowell, Michael W.; Kong, Desheng; Cha, Judy J.; McDonough, James R.; Zhu, Jia; Yang, Yuan; McGehee, Michael D.; Cui, Yi

2010-01-01

Transparent electrodes, indespensible in displays and solar cells, are currently dominated by indium tin oxide (ITO) films although the high price of indium, brittleness of films, and high vacuum deposition are limiting their applications. Recently, solution-processed networks of nanostructures such as carbon nanotubes (CNTs), graphene, and silver nanowires have attracted great attention as replacements. A low junction resistance between nanostructures is important for decreasing the sheet resistance. However, the junction resistances between CNTs and boundry resistances between graphene nanostructures are too high. The aspect ratios of silver nanowires are limited to ∼100, and silver is relatively expensive. Here, we show high-performance transparent electrodes with copper nanofiber networks by a low-cost and scalable electrospinning process. Copper nanofibers have ultrahigh aspect ratios of up to 100000 and fused crossing points with ultralow junction resistances, which result in high transmitance at low sheet resistance, e.g., 90% at 50 Ω/sq. The copper nanofiber networks also show great flexibility and stretchabilty. Organic solar cells using copper nanowire networks as transparent electrodes have a power efficiency of 3.0%, comparable to devices made with ITO electrodes. © 2010 American Chemical Society.

A Viable Electrode Material for Use in Microbial Fuel Cells for Tropical Regions

Directory of Open Access Journals (Sweden)

Felix Offei

2016-01-01

Full Text Available Electrode materials are critical for microbial fuel cells (MFC since they influence the construction and operational costs. This study introduces a simple and efficient electrode material in the form of palm kernel shell activated carbon (AC obtained in tropical regions. The novel introduction of this material is also targeted at introducing an inexpensive and durable electrode material, which can be produced in rural communities to improve the viability of MFCs. The maximum voltage and power density obtained (under 1000 Ω load using an H-shaped MFC with AC as both anode and cathode electrode material was 0.66 V and 1.74 W/m3, respectively. The power generated by AC was as high as 86% of the value obtained with the extensively used carbon paper. Scanning electron microscopy and Denaturing Gradient Gel Electrophoresis (DGGE analysis of AC anode biofilms confirmed that electrogenic bacteria were present on the electrode surface for substrate oxidation and the formation of nanowires.

Low-cost uncooled VOx infrared camera development

Science.gov (United States)

Li, Chuan; Han, C. J.; Skidmore, George D.; Cook, Grady; Kubala, Kenny; Bates, Robert; Temple, Dorota; Lannon, John; Hilton, Allan; Glukh, Konstantin; Hardy, Busbee

2013-06-01

The DRS Tamarisk® 320 camera, introduced in 2011, is a low cost commercial camera based on the 17 µm pixel pitch 320×240 VOx microbolometer technology. A higher resolution 17 µm pixel pitch 640×480 Tamarisk®640 has also been developed and is now in production serving the commercial markets. Recently, under the DARPA sponsored Low Cost Thermal Imager-Manufacturing (LCTI-M) program and internal project, DRS is leading a team of industrial experts from FiveFocal, RTI International and MEMSCAP to develop a small form factor uncooled infrared camera for the military and commercial markets. The objective of the DARPA LCTI-M program is to develop a low SWaP camera (costs less than US $500 based on a 10,000 units per month production rate. To meet this challenge, DRS is developing several innovative technologies including a small pixel pitch 640×512 VOx uncooled detector, an advanced digital ROIC and low power miniature camera electronics. In addition, DRS and its partners are developing innovative manufacturing processes to reduce production cycle time and costs including wafer scale optic and vacuum packaging manufacturing and a 3-dimensional integrated camera assembly. This paper provides an overview of the DRS Tamarisk® project and LCTI-M related uncooled technology development activities. Highlights of recent progress and challenges will also be discussed. It should be noted that BAE Systems and Raytheon Vision Systems are also participants of the DARPA LCTI-M program.

48 CFR 9904.420 - Accounting for independent research and development costs and bid and proposal costs.

Science.gov (United States)

2010-10-01

... Regulations System COST ACCOUNTING STANDARDS BOARD, OFFICE OF FEDERAL PROCUREMENT POLICY, OFFICE OF MANAGEMENT AND BUDGET PROCUREMENT PRACTICES AND COST ACCOUNTING STANDARDS COST ACCOUNTING STANDARDS 9904.420 Accounting for independent research and development costs and bid and proposal costs. ...

Electrochemical immunosensors for the detection of survival motor neuron (SMN) protein using different carbon nanomaterials-modified electrodes.

Science.gov (United States)

Eissa, Shimaa; Alshehri, Nawal; Rahman, Anas M Abdel; Dasouki, Majed; Abu-Salah, Khalid M; Zourob, Mohammed

2018-03-15

Spinal muscular atrophy is an untreatable potentially fatal hereditary disorder caused by loss-of-function mutations in the survival motor neuron (SMN) 1 gene which encodes the SMN protein. Currently, definitive diagnosis relies on the demonstration of biallelic pathogenic variants in SMN1 gene. Therefore, there is an urgent unmet need to accurately quantify SMN protein levels for screening and therapeutic monitoring of symptomatic newborn and SMA patients, respectively. Here, we developed a voltammetric immunosensor for the sensitive detection of SMN protein based on covalently functionalized carbon nanofiber-modified screen printed electrodes. A comparative study of six different carbon nanomaterial-modified electrodes (carbon, graphene (G), graphene oxide (GO), single wall carbon nanotube (SWCNT), multi-wall carbon nanotube (MWCNT), and carbon nanofiber (CNF)) was performed. 4-carboxyphenyl layers were covalently grafted on the six electrodes by electroreduction of diazonium salt. Then, the terminal carboxylic moieties on the electrodes surfaces were utilized to immobilize the SMN antibody via EDC/NHS chemistry and to fabricate the immunosensors. The electrochemical characterization and analytical performance of the six immunosensors suggest that carbon nanofiber is a better electrode material for the SMN immunosensor. The voltammetric SMN carbon nanofiber-based immunosensor showed high sensitivity (detection limit of 0.75pg/ml) and selectivity against other proteins such as cystic fibrosis transmembrane conductance regulator (CFTR) and dystrophin (DMD). We suggest that this novel biosensor is superior to other developed assays for SMN detection in terms of lower cost, higher sensitivity, simplicity and capability of high throughput screening. Copyright © 2017 Elsevier B.V. All rights reserved.

Graphene-based materials for supercapacitor electrodes – A review

Directory of Open Access Journals (Sweden)

Qingqing Ke

2016-03-01

Full Text Available The graphene-based materials are promising for applications in supercapacitors and other energy storage devices due to the intriguing properties, i.e., highly tunable surface area, outstanding electrical conductivity, good chemical stability and excellent mechanical behavior. This review summarizes recent development on graphene-based materials for supercapacitor electrodes, based on their macrostructural complexity, i.e., zero-dimensional (0D (e.g. free-standing graphene dots and particles, one-dimensional (1D (e.g. fiber-type and yarn-type structures, two-dimensional (2D (e.g. graphenes and graphene-based nanocomposite films, and three-dimensional (3D (e.g. graphene foam and hydrogel-based nanocomposites. There are extensive and on-going researches on the rationalization of their structures at varying scales and dimensions, development of effective and low cost synthesis techniques, design and architecturing of graphene-based materials, as well as clarification of their electrochemical performance. It is indicated that future studies should focus on the overall device performance in energy storage devices and large-scale process in low costs for the promising applications in portable and wearable electronic, transport, electrical and hybrid vehicles.

Assessing and forecasting groundwater development costs in Sub ...

African Journals Online (AJOL)

Greater use of groundwater in Sub-Saharan Africa is a pre-requisite for improved human welfare; however, the costs associated with groundwater development are prohibitively high and poorly defined. This study identifies and disaggregates the costs of groundwater development in 11 Sub-Saharan African countries, while ...

Electron transfer at boron-doped diamond electrodes modified by graphitic micro-domains

Energy Technology Data Exchange (ETDEWEB)

Mahe, E.; Devilliers, D. [Pierre et Marie Curie Univ., Paris (France). Electrochemistry Lab.; Comninellis, C. [Lausanne Ecole Polytechnique, Lausanne (Switzerland). Groupe de Genie Electrochimique

2006-07-01

Boron-doped (BDD) electrodes have been used in electrolysis procedures for the last 10 years. The mechanical stability of the electrode, its large electrochemical window and its low capacitive current place this new electrode material as an alternative for replacing more costly or toxic materials such as mercury. However, the ferri/ferrocyanide system of boron-doped electrodes has shown contradictory results in the literature. This study proposed a cathodic pre-treatment which relied on the presence of residual graphitic domains formed during the preparation of the BDD film. An experiment was conducted in which the doping procedure was used to control the amount of graphitic phase on the electrode with highly oriented pyrolytic graphite (HOPG) grafted on the BDD surface. Surface characterization with Raman spectroscopy and Scanning Electron Microscopy (SEM) was then carried out using cyclic voltammetry and electrochemical impedance spectroscopy. The electroanalytical determination of the amount of graphitic micro-domains was described and a pulse procedure was proposed which obtained a reproducible surface state. 2 refs., 2 figs.

Enhanced performance of flexible dye-sensitized solar cells using flexible Ag@ZrO2/C nanofiber film as low-cost counter electrode

Science.gov (United States)

Yin, Xin; Xie, Xueyao; Song, Lixin; Zhai, Jifeng; Du, Pingfan; Xiong, Jie

2018-05-01

Highly flexible ZrO2/C nanofibers (NFs) coated with Ag nanoparticles (NPs) have been fabricated by a combination of electrospinning, carbonization and hydrothermal treatment. The obtained Ag@ZrO2/C NFs serve as low-cost counter electrodes (CEs) for flexible dye-sensitized solar cells (FDSSCs). A considerable power conversion efficiency of 4.77% is achieved, which is 27.9% higher than the η of ZrO2/C NFs CEs (3.73%) and reaches about 90% of that of Pt CE (5.26%). It can be ascribed to the fact that the introduction of Ag NPs provides a large number of accessible reaction sites for electrolyte ions to rapidly participate in the I3-/I- reaction. Moreover, the Ag NPs can produce synergistic effect with ZrO2/C NFs to further enhance transport capacity and electro-catalytic activity of the Ag@ZrO2/C film. Therefore, the considerable performance together with characteristics of simple preparation, low cost and flexibility suggests the Ag@ZrO2/C film can be promising candidate for the future generation of FDSSC.

Use of the optical lithography in the development of disposable carbon based electrodes - doi: 10.4025/actascitechnol.v35i1.11915

Directory of Open Access Journals (Sweden)

Lucilene Dornelles Mello

2013-01-01

Full Text Available In this study, carbon-based electrodes for disposable use were constructed using the technique of optical lithography. The process consisted in the irradiation of UV light on a layer of photosensitive resin (SU-8 50 deposited on a substrate of PVC. The pattern obtained electrode was filled with carbon paste. The electrodes were characterized by cyclic voltammetric using the reversible system Fe(CN63-/Fe(CN64- in KCl 0.1 mol L-1 and electrochemical impedance spectroscopy (EIS. The electrodes showed an E°’ = ½ (Epa + Epc » 229 (± 2 mV vs SCE (n = 4, with DEp » 235 (± 14 mV (n = 4. Other studies showed a linear behavior of the peak current (Ip both anode and cathode with v1/2, probably due to diffuse contribution and/or electron transfer kinetics of the reaction. These parameters are in accordance to with those obtained for screen-printed electrode described in the literature. The good results obtained show the suitability of the electrodes for analytical applications such as development of sensors.  

Bromination of Graphene: A New Route to Making High Performance Transparent Conducting Electrodes with Low Optical Losses

KAUST Repository

Mansour, Ahmed

2015-07-22

The unique optical and electrical properties of graphene have triggered great interest in its application as a transparent conducting electrode material and significant effort has been invested in achieving high conductivity while maintaining transparency. Doping of graphene has been a popular route for reducing its sheet resistance, but this has typically come at a significant cost in optical transmission. We demonstrate doping of few layers graphene with bromine as a means of enhancing the conductivity via intercalation without major optical losses. Our results demonstrate the encapsulation of bromine leads to air-stable transparent conducting electrodes with five-fold improvement of sheet resistance reaching at the cost of only 2-3% loss of optical transmission. The remarkably low tradeoff in optical transparency leads to the highest enhancements in the figure of merit reported thus far for FLG. Furthermore, we tune the workfunction by up to 0.3 eV by tuning the bromine content. These results should help pave the way for further development of graphene as a potential substitute to transparent conducting polymers and metal oxides used in optoelectronics, photovoltaics and beyond.

All-Carbon Electrode Consisting of Carbon Nanotubes on Graphite Foil for Flexible Electrochemical Applications

Directory of Open Access Journals (Sweden)

Je-Hwang Ryu

2014-03-01

Full Text Available We demonstrate the fabrication of an all-carbon electrode by plasma-enhanced chemical vapor deposition for use in flexible electrochemical applications. The electrode is composed of vertically aligned carbon nanotubes that are grown directly on a flexible graphite foil. Being all-carbon, the simple fabrication process and the excellent electrochemical characteristics present an approach through which high-performance, highly-stable and cost-effective electrochemical applications can be achieved.

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.

Preparation of nitrogen-doped biomass-derived carbon nanofibers/graphene aerogel as a binder-free electrode for high performance supercapacitors

Science.gov (United States)

Zhang, Yimei; Wang, Fei; Zhu, Hao; Zhou, Lincheng; Zheng, Xinliang; Li, Xinghua; Chen, Zhuang; Wang, Yue; Zhang, Dandan; Pan, Duo

2017-12-01

Carbon materials derived from various biomasses have aroused forceful interest from scientific community based on their abundant resource, low cost, environment friendly and easy fabrication. Herein, the method has been developed to prepare nitrogen-doped biomass-derived carbon nanofibers/graphene aerogel (NCGA) as the binder-free electrode for supercapacitors. Ethylenediamine (EDA) is select as nitrogen source for its high nitrogen content and strong interaction with graphene oxide (GO) and cellulose nanofibers (CNFs) via hydrothermal self-assembly method to form hybrid hydrogel, and finally converts to NCGA by freeze-drying and carbonization. After carbonization the insulated CNFs converted to high conductivity carbon nanofibers. The NCGA electrode exhibits a high specific capacitance of 289 F g-1 at 5 mV s-1 and high stability of 90.5% capacitance retention ratio after 5000 cycles at 3 A g-1. This novel biomass electrode could be potential candidate for high performance supercapacitors.

Electrochemical supercapacitor electrode material based on polyacrylic acid/polypyrrole/silver composite

International Nuclear Information System (INIS)

Patil, Dipali S.; Pawar, Sachin A.; Devan, Rupesh S.; Gang, Myeng Gil; Ma, Yuon-Ron; Kim, Jin Hyeok; Patil, Pramod S.

2013-01-01

Highlights: • Polyacrylic acid/polypyrrole/silver composite prepared by chemical polymerization method. • The presence of Ag nanoparticles on PPY spherical granules provides the least resistance path to electron. • The specific capacitance about 145 F g −1 and 226 F g −1 observed for PPY/PAA and PPY/PAA/Ag samples, respectively. • The higher specific energy 7.18 Wh kg −1 and 17.45 Wh kg −1 observed for PPY/PAA and PPY/PAA/Ag respectively at current density of 0.5 mA cm −2 . -- Abstract: In the present work, we have synthesized polypyrrole (PPY)/polyacrylic acid (PAA)/silver (Ag) composite electrodes by chemical polymerization via a simple and cost effective dip coating technique for supercapacitor application. Fourier transform-infrared, Fourier transform-Raman, X-ray photoelectron and energy dispersive X-ray spectroscopy techniques are used for the phase identification. Surface morphology of the films is examined by field emission scanning electron microscopy, which revealed granular structure for PPY, spherical interlaced granules for PPY/PAA and granules with bright spots of Ag nanoparticles for the PPY/PAA/Ag composites. The supercapacitive behavior of the electrodes is tested in three electrode system with 0.1 M H 2 SO 4 electrolyte by using cyclic voltammetery and charge discharge test. The highest specific capacitance 226 F g −1 at 10 mV s −1 and energy density of 17.45 Wh kg −1 at 0.5 mA cm −2 is obtained for the PPY/PAA/Ag composite electrodes. Present work demonstrates an easy way of improving specific capacitance of the polymer electrodes. Thus the work will open a new avenue for designing low cost high performance devices for better supercapacitors

Monolithic and Flexible ZnS/SnO2 Ultraviolet Photodetectors with Lateral Graphene Electrodes.

Science.gov (United States)

Zhang, Cheng; Xie, Yunchao; Deng, Heng; Tumlin, Travis; Zhang, Chi; Su, Jheng-Wun; Yu, Ping; Lin, Jian

2017-05-01

A continuing trend of miniaturized and flexible electronics/optoelectronic calls for novel device architectures made by compatible fabrication techniques. However, traditional layer-to-layer structures cannot satisfy such a need. Herein, a novel monolithic optoelectronic device fabricated by a mask-free laser direct writing method is demonstrated in which in situ laser induced graphene-like materials are employed as lateral electrodes for flexible ZnS/SnO 2 ultraviolet photodetectors. Specifically, a ZnS/SnO 2 thin film comprised of heterogeneous ZnS/SnO 2 nanoparticles is first coated on polyimide (PI) sheets by a solution process. Then, CO 2 laser irradiation ablates designed areas of the ZnS/SnO 2 thin film and converts the underneath PI into highly conductive graphene as the lateral electrodes for the monolithic photodetectors. This in situ growth method provides good interfaces between the graphene electrodes and the semiconducting ZnS/SnO 2 resulting in high optoelectronic performance. The lateral electrode structure reduces total thickness of the devices, thus minimizing the strain and improving flexibility of the photodetectors. The demonstrated lithography-free monolithic fabrication is a simple and cost-effective method, showing a great potential for developement into roll-to-roll manufacturing of flexible electronics. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Characterization of textile electrodes and conductors using standardized measurement setups

International Nuclear Information System (INIS)

Beckmann, L; Neuhaus, C; Medrano, G; Walter, M; Leonhardt, S; Jungbecker, N; Gries, T

2010-01-01

Textile electrodes and conductors are being developed and used in different monitoring scenarios, such as ECG or bioimpedance spectroscopy measurements. Compared to standard materials, conductive textile materials offer improved wearing comfort and enable long-term measurements. Unfortunately, the development and investigation of such materials often suffers from the non-reproducibility of the test scenarios. For example, the materials are generally tested on human skin which is difficult since the properties of human skin differ for each person and can change within hours. This study presents two test setups which offer reproducible measurement procedures for the systematic analysis of textile electrodes and conductors. The electrode test setup was designed with a special skin dummy which allows investigation of not only the electrical properties of textile electrodes but also the contact behavior between electrode and skin. Using both test setups, eight textile electrodes and five textile conductors were analyzed and compared

A wearable 12-lead ECG acquisition system with fabric electrodes.

Science.gov (United States)

Haoshi Zhang; Lan Tian; Huiyang Lu; Ming Zhou; Haiqing Zou; Peng Fang; Fuan Yao; Guanglin Li

2017-07-01

Continuous electrocardiogram (ECG) monitoring is significant for prevention of heart disease and is becoming an important part of personal and family health care. In most of the existing wearable solutions, conventional metal sensors and corresponding chips are simply integrated into clothes and usually could only collect few leads of ECG signals that could not provide enough information for diagnosis of cardiac diseases such as arrhythmia and myocardial ischemia. In this study, a wearable 12-lead ECG acquisition system with fabric electrodes was developed and could simultaneously process 12 leads of ECG signals. By integrating the fabric electrodes into a T-shirt, the wearable system would provide a comfortable and convenient user interface for ECG recording. For comparison, the proposed fabric electrode and the gelled traditional metal electrodes were used to collect ECG signals on a subject, respectively. The approximate entropy (ApEn) of ECG signals from both types of electrodes were calculated. The experimental results show that the fabric electrodes could achieve similar performance as the gelled metal electrodes. This preliminary work has demonstrated that the developed ECG system with fabric electrodes could be utilized for wearable health management and telemedicine applications.

Studies on Perovskite-Based Electrodes for Symmetrical SOFCs

Directory of Open Access Journals (Sweden)

Dos Santos García, A. J.

2008-10-01

Full Text Available The use of the same material as anode and cathode in symmetrical solid oxide fuel cells (SFCs promises notable benefits as easier fabrication, hence lower cost production and resistance to carbon formation upon fuel cracking. Although chromites and chromo-manganites have been proposed as candidate electrode materials for this novel SOFC configuration, demonstrating promising performances, further work is required to develop compositions exhibiting higher efficiencies. In the present work we evaluate the structural evolution from cubic to orthorhombic unit cells with increasing the Fe content and the performance of La₄Sr₈Ti_12-xFe_xO_38-δ (LSTF phases and compare their response with other symmetrical electrodes. The electrochemical performance is 20% higher when using graded LSTF electrodes than in other perovskite-based systems.

La utilización simultánea de un mismo material cerámico como ánodo y cátodo en pilas de combustible de óxido sólido simétricas (SFCs aporta una serie de beneficios entre los que figura una fabricación más sencilla, reducción de los costes de producción, así como resistencia a la formación de depósitos de carbón por craqueo del combustible. Recientemente, cromitas y cromomanganitas han sido propuestos como materiales capaces de adoptar esta novedosa configuración SOFC y, si bien los resultados obtenidos son prometedores, se requiere de una mayor investigación para el desarrollo de nuevas composiciones que presenten eficiencias más elevadas. En el presente trabajo, se evalúan la evolución de la estructura desde celdas cúbicas a ortorrómbicas al aumentar el contenido en Fe y las prestaciones del sistema La₄Sr₈Ti_12-xFe_xO_38-δ (LSTF y se compara su respuesta con otros electrodos simétricos, observándose que el rendimiento es hasta un 20% mayor en el caso de emplear electrodos LSTF que en

Developing and Analysing sub-10 µm Fluidic Systems with Integrated Electrodes for Pumping and Sensing in Nanotechnology Applications

NARCIS (Netherlands)

Heuck, F.C.A.

2010-01-01

In this thesis, sub-10 µm fluidic systems with integrated electrodes for pumping and sensing in nanotechnology applications were developed and analyzed. This work contributes to the development of the scanning ion pipette (SIP), a tool to investigate surface changes on the nanometer scale induced by

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.

A study on cross-talk nerve stimulation: electrode placement and current leakage lid

Directory of Open Access Journals (Sweden)

Nicolas Julémont

2016-07-01

Full Text Available Cross-talk phenomena should be avoided when stimulating nerves. One option to limit the current spread is to use tripolar electrodes, but at the cost of increasing the number of wires connection. This should be avoided since cables must be thin and compliant. We investigated the impact of the central electrode position and of current spread due to a gap between book and lid on cross-talk, in a set of tripolar or quasi-tripolar configurations.

Processing of poly-Si electrodes for charge-coupled devices

Energy Technology Data Exchange (ETDEWEB)

Sherohman, J.W.; Cook, F.D.

1978-12-06

A technique has been developed to fabricate poly-Si electrodes for charge-coupled devices. By controlling the microstructure of a poly-Si film, an anisotropic etchant was selected to provide essentially uniform electrode width dimensions. The electrode widths have only a 6% variation for the majority of the devices over the area of a 2 inch silicon wafer.

Single electrode electrochemical detection in hybrid poly(dimethylsiloxane)/glass multichannel micro devices

Energy Technology Data Exchange (ETDEWEB)

Moreira, Ney Henrique; Almeida, Andre Luis de Jesus de; Piazzeta, Maria Helena de Oliveira; Gobbia, Angelo Luiz [Laboratorio Nacional de Luz Sincrotron (LNLS), Campinas, SP (Brazil). Lab. de Microfabricacao; Jesus, Dosil Pereira de [Instituto Nacional de Ciencia e Tecnologia em Bioanalitica (INCTBio), Campinas, SP (Brazil); Deblire, Ariane; Silva, Jose Alberto Fracassi da [Universidade Estadual de Campinas (IQ/UNICAMP), SP (Brazil). Inst. de Quimica

2009-07-01

The fabrication process of a novel multichannel {mu}TAS based on PDMS and glass materials and with fully-integrated electrodes for amperometric detection has been described. Using the facilities of the Microfabrication Lab. (LMF) at Brazilian Synchrotron Light Laboratory (LNLS), soft-lithography, lift-off and O{sub 2} plasma surface activation sealing techniques were employed for rapid proto typing of cost effective PDMS/glass microchips. Fast calibration procedures were possible for the electro oxidation of hydroquinone, thiocyanate, and acetaminophen using Au and Cu electrodes. (author)

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

Science.gov (United States)

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

2006-01-01

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

High-Efficient Low-Cost Photovoltaics Recent Developments

CERN Document Server

Petrova-Koch, Vesselinka; Goetzberger, Adolf

2009-01-01

A bird's-eye view of the development and problems of recent photovoltaic cells and systems and prospects for Si feedstock is presented. High-efficient low-cost PV modules, making use of novel efficient solar cells (based on c-Si or III-V materials), and low cost solar concentrators are in the focus of this book. Recent developments of organic photovoltaics, which is expected to overcome its difficulties and to enter the market soon, are also included.

Synthesis of layered LiMnO2 as an electrode for rechargeable lithium batteries

Science.gov (United States)

Armstrong, A. Robert; Bruce, Peter G.

1996-06-01

RECHARGEABLE lithium batteries can store more than twice as much energy per unit weight and volume as other rechargeable batteries1,2. They contain lithium ions in an electrolyte, which shuttle back and forth between, and are intercalated by, the electrode materials. The first commercially successful rechargeable lithium battery3, introduced by the Sony Corporation in 1990, consists of a carbon-based negative electrode, layered LiCoO2 as the positive electrode, and a non-aqueous liquid electrolyte. The high cost and toxicity of cobalt compounds, however, has prompted a search for alternative materials that intercalate lithium ions. One such is LiMn2O4, which has been much studied as a positive electrode material4-7 the cost of manganese is less than 1% of that of cobalt, and it is less toxic. Here we report the synthesis and electrochemical performance of a new material, layered LiMnO2, which is structurally analogous to LiCoO2. The charge capacity of LiMnO2 (~270mAhg-1) compares well with that of both LiCoO2 and LiMn2O4, and preliminary results indicate good stability over repeated charge-discharge cycles.

High Temperature Electrolysis using Electrode-Supported Cells

International Nuclear Information System (INIS)

O'Brien, J.E.; Stoots, C.M.

2010-01-01

An experimental study is under way to assess the performance of electrode-supported solid-oxide cells operating in the steam electrolysis mode for hydrogen production. The cells currently under study were developed primarily for the fuel cell mode of operation. Results presented in this paper were obtained from single cells, with an active area of 16 cm2 per cell. The electrolysis cells are electrode-supported, with yttria-stabilized zirconia (YSZ) electrolytes (∼10 (micro)m thick), nickel-YSZ steam/hydrogen electrodes (∼1400 (micro)m thick), and manganite (LSM) air-side electrodes (∼90 (micro)m thick). The purpose of the present study was to document and compare the performance and degradation rates of these cells in the fuel cell mode and in the electrolysis mode under various operating conditions. Initial performance was documented through a series of DC potential sweeps and AC impedance spectroscopy measurements. Degradation was determined through long-duration testing, first in the fuel cell mode, then in the electrolysis mode over more than 500 hours of operation. Results indicate accelerated degradation rates in the electrolysis mode compared to the fuel cell mode, possibly due to electrode delamination. The paper also includes details of the single-cell test apparatus developed specifically for these experiments.

Erosion on spark plug electrodes; Funkenerosion an Zuendkerzenelektroden

Energy Technology Data Exchange (ETDEWEB)

Rager, J.

2006-07-01

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

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.

Electrochemically active biofilm and photoelectrocatalytic regeneration of the titanium dioxide composite electrode for advanced oxidation in water treatment

International Nuclear Information System (INIS)

Bennani, Yasmina; Peters, Marjolein C.F.M.; Appel, Peter W.; Rietveld, Luuk C.

2015-01-01

A novel bio-photoelectrocatalytic system was used to effectively reduce phenol as a model organic pollutant through the utilization of energy derived from bacteria and the use of solar energy for activation of TiO 2 . In such a system, a synergistic effect occurs between the bio-electrochemical and photocatalytic oxidation processes. TiO 2 /Ti composite electrodes were operated with variable biofilm coverage (partially developed biofilm after 6 days and fully developed biofilms after 12, 20 and 40 days at room temperature and pH 7). The study depicted the effectiveness of biofilm formation in enhancing the electron transfer. Kinetic analysis showed that the system exhibited a more rapid phenol degradation at a rate two times higher than rates by individual photo(electro) catalytic and biodegradable methods. Higher current density (8.4 × 10 −2 mAcm −2 ) and phenol removal efficiency of 62% after four hours of irradiation were observed especially with electrochemically active biofilm developed after 20 days. TiO 2 /Ti composite electrode. After the additional application of cleaning process, the TiO 2 /Ti composite electrode could be used several times with nearly the same efficiency, leading to decrease in the final cost of the treatment process.

Low-cost, low-weight CNG cylinder development. Final report

Energy Technology Data Exchange (ETDEWEB)

Richards, Mark E.; Melford, K.; Wong, J.; Gambone, L.

1999-09-01

This program was established to develop and commercialize new high-strength steel-lined, composite hoop-wrapped compressed natural gas (CNG) cylinders for vehicular applications. As much as 70% of the cost of natural gas vehicles can be related to on-board natural gas storage costs. The cost and weight targets for this program represent significant savings in each characteristic when compared to comparable containers available at the initiation of the program. The program objectives were to optimize specific weight and cost goals, yielding CNG cylinders with dimensions that should, allowing for minor modifications, satisfy several vehicle market segments. The optimization process encompassed material, design, and process improvement. In optimizing the CNG cylinder design, due consideration was given to safety aspects relative to national, international, and vehicle manufacturer cylinder standards and requirements. The report details the design and development effort, encompassing plant modifications, material selection, design issues, tooling development, prototype development, and prototype testing. Extenuating circumstances prevented the immediate commercialization of the cylinder designs, though significant progress was made towards improving the cost and performance of CNG cylinders. A new low-cost fiber was successfully employed while the weight target was met and the cost target was missed by less than seven percent.

Electrolytic trichloroethene degradation using mixed metal oxide coated titanium mesh electrodes.

Science.gov (United States)

Petersen, Matthew A; Sale, Thomas C; Reardon, Kenneth F

2007-04-01

Electrochemical systems provide a low cost, versatile, and controllable platform to potentially treat contaminants in water, including chlorinated solvents. Relative to bare metal or noble metal amended materials, dimensionally stable electrode materials such as mixed metal oxide coated titanium (Ti/MMO) have advantages in terms of stability and cost, important factors for sustainable remediation solutions. Here, we report the use of Ti/MMO as an effective cathode substrate for treatment of trichloroethene (TCE). TCE degradation in a batch reactor was measured as the decrease of TCE concentration over time and the corresponding evolution of chloride; notably, this occurred without the formation of commonly encountered chlorinated intermediates. The reaction was initiated when Ti/MMO cathode potentials were less than -0.8 V vs. the standard hydrogen electrode, and the rate of TCE degradation increased linearly with progressively more negative potentials. The maximum pseudo-first-order heterogeneous rate constant was approximately 0.05 cm min(-1), which is comparable to more commonly used cathode materials such as nickel. In laboratory-scale flow-though column reactors designed to simulate permeable reactive barriers (PRBs), TCE concentrations were reduced by 80-90%. The extent of TCE flux reduction increased with the applied potential difference across the electrodes and was largely insensitive to the spacing distance between the electrodes. This is the first report of the electrochemical reduction of a chlorinated organic contaminant at a Ti/MMO cathode, and these results support the use of this material in PRBs as a possible approach to manage TCE plume migration.

Hierarchical porous carbon aerogel derived from bagasse for high performance supercapacitor electrode.

Science.gov (United States)

Hao, Pin; Zhao, Zhenhuan; Tian, Jian; Li, Haidong; Sang, Yuanhua; Yu, Guangwei; Cai, Huaqiang; Liu, Hong; Wong, C P; Umar, Ahmad

2014-10-21

Renewable, cost-effective and eco-friendly electrode materials have attracted much attention in the energy conversion and storage fields. Bagasse, the waste product from sugarcane that mainly contains cellulose derivatives, can be a promising candidate to manufacture supercapacitor electrode materials. This study demonstrates the fabrication and characterization of highly porous carbon aerogels by using bagasse as a raw material. Macro and mesoporous carbon was first prepared by carbonizing the freeze-dried bagasse aerogel; consequently, microporous structure was created on the walls of the mesoporous carbon by chemical activation. Interestingly, it was observed that the specific surface area, the pore size and distribution of the hierarchical porous carbon were affected by the activation temperature. In order to evaluate the ability of the hierarchical porous carbon towards the supercapacitor electrode performance, solid state symmetric supercapacitors were assembled, and a comparable high specific capacitance of 142.1 F g(-1) at a discharge current density of 0.5 A g(-1) was demonstrated. The fabricated solid state supercapacitor displayed excellent capacitance retention of 93.9% over 5000 cycles. The high energy storage ability of the hierarchical porous carbon was attributed to the specially designed pore structures, i.e., co-existence of the micropores and mesopores. This research has demonstrated that utilization of sustainable biopolymers as the raw materials for high performance supercapacitor electrode materials is an effective way to fabricate low-cost energy storage devices.

Fabrication and performance of Li4Ti5O12/C Li-ion battery electrodes using combined double flame spray pyrolysis and pressure-based lamination technique

Science.gov (United States)

Gockeln, Michael; Pokhrel, Suman; Meierhofer, Florian; Glenneberg, Jens; Schowalter, Marco; Rosenauer, Andreas; Fritsching, Udo; Busse, Matthias; Mädler, Lutz; Kun, Robert

2018-01-01

Reduction of lithium-ion battery (LIB) production costs is inevitable to make the use of LIB technology more viable for applications such as electric vehicles or stationary storage. To meet the requirements in today's LIB cost efficiency, our current research focuses on an alternative electrode fabrication method, characterized by a combination of double flame spray pyrolysis and lamination technique (DFSP/lamination). In-situ carbon coated nano-Li4Ti5O12 (LTO/C) was synthesized using versatile DFSP. The as-prepared composite powder was then directly laminated onto a conductive substrate avoiding the use of any solvent or binder for electrode preparation. The influence of lamination pressures on the microstructure and electrochemical performance of the electrodes was also investigated. Enhancements in intrinsic electrical conductivity were found for higher lamination pressures. Capacity retention of highest pressurized DFSP/lamination-prepared electrode was 87.4% after 200 dis-/charge cycles at 1C (vs. Li). In addition, LTO/C material prepared from the double flame spray pyrolysis was also used for fabricating electrodes via doctor blading technique. Laminated electrodes obtained higher specific discharge capacities compared to calendered and non-calendered blade-casted electrodes due to superior microstructural properties. Such a fast and industrially compelling integrative DFSP/lamination tool could be a prosperous, next generation technology for low-cost LIB electrode fabrication.

Carbon nanotube fiber mats for microbial fuel cell electrodes.

Science.gov (United States)

Delord, Brigitte; Neri, Wilfrid; Bertaux, Karen; Derre, Alain; Ly, Isabelle; Mano, Nicolas; Poulin, Philippe

2017-11-01

Novel carbon nanotube based electrodes of microbial fuel cells (MFC) have been developed. MFC is a promising technology for the wastewater treatment and the production of electrical energy from redox reactions of natural substrates. Performances of such bio-electrochemical systems depend critically on the structure and properties of the electrodes. The presently developed materials are made by weaving fibers solely comprised of carbon nanotubes. They exhibit a large scale porosity controlled by the weaving process. This porosity allows an easy colonization by electroactive bacteria. In addition, the fibers display a nanostructuration that promotes excellent growth and adhesion of the bacteria at the surface of the electrodes. This unique combination of large scale porosity and nanostructuration allows the present electrodes to perform better than carbon reference. When used as anode in a bioelectrochemical reactor in presence of Geobacter sulfurreducens bacteria, the present electrodes show a maximal current density of about 7.5mA/cm 2 . Copyright © 2017 Elsevier Ltd. All rights reserved.

CFD analysis of a symmetrical planar SOFC with heterogeneous electrode properties

International Nuclear Information System (INIS)

Shi Junxiang; Xue Xingjian

2010-01-01

A comprehensive 2-D CFD model is developed to investigate bi-electrode supported cell (BSC) performance. The model takes into account the coupled complex transport phenomena of mass/heat transfer, charge (electron/ion) transport, and electrochemical reactions. The uniqueness of this modeling work is that heterogeneous electrode properties are taken into account, which includes not only linear functionally graded porosity distribution but also various nonlinear distributions in a general sense according to porous electrode features in BSC design. Extensive numerical analysis is performed to elucidate various heterogeneous porous electrode property effects on cell performance. Results indicate that cell performance is strongly dependent on porous microstructure distributions of electrodes. Among the various porosity distributions, inverse parabolic porosity distribution shows promising effects on cell performance. For a given porosity distribution of electrodes, cell performance is also dependent on operating conditions, typically fuel/gas pressure losses across the electrodes. The mathematical model developed in this paper can be utilized for high performance BSC SOFC design and optimization.

48 CFR 731.773 - Independent research and development costs.

Science.gov (United States)

2010-10-01

... Organizations 731.773 Independent research and development costs. Pending establishment of Government-wide... independent research and development costs. ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Independent research and...

Fabrication of Nickel/nanodiamond/boron-doped diamond electrode for non-enzymatic glucose biosensor

International Nuclear Information System (INIS)

Dai, Wei; Li, Mingji; Gao, Sumei; Li, Hongji; Li, Cuiping; Xu, Sheng; Wu, Xiaoguo; Yang, Baohe

2016-01-01

Highlights: • Nanodiamonds (NDs) were electrophoretically deposited on the BDD film. • The NDs significantly extended the potential window. • Ni/NDs/BDD electrode was prepared by electrodeposition. • The electrode shows good catalytic activity for glucose oxidation. - Abstract: A stable and sensitive non-enzymatic glucose sensor was prepared by modifying a boron-doped diamond (BDD) electrode with nickel (Ni) nanosheets and nanodiamonds (NDs). The NDs were electrophoretically deposited on the BDD surface, and acted as nucleation sites for the subsequent electrodeposition of Ni. The morphology and composition of the modified BDD electrodes were characterized by field-emission scanning electron microscopy and energy-dispersive X-ray spectroscopy, respectively. The Ni nanosheet-ND modified BDD electrode exhibited good current response towards the non-enzymatic oxidation of glucose in alkaline media. The NDs significantly extended the potential window. The response to glucose was linear over the 0.2–1055.4-μM range. The limit of detection was 0.05 μM, at a signal-to-noise ratio of 3. The Ni nanosheet-ND/BDD electrode exhibited good selectivity, reproducibility and stability. Its electrochemical performance, low cost and simple preparation make it a promising non-enzymatic glucose sensor.

Carbon: The Ultimate Electrode Choice for Widely Distributed Polymer Solar Cells

DEFF Research Database (Denmark)

Benatto, Gisele Alves dos Reis; Roth, Bérenger; Madsen, Morten Vesterager

2014-01-01

-, indium tin oxide (ITO)-, and silver-free solar cells in a fully packaged form using only roll-to-roll processing is reported. Replacing silver with carbon as electrode material signifi cantly lowers the manufacturing cost and makes the organic photovoltaic (OPV) modules environmentally safe while...... retaining their fl exibility, active area effi ciency, and stability. The substitution of silver with carbon does not affect the roll-to-roll manufacturing of the modules and allows for the same fast printing and coating. The use of carbon as electrode material is one step closer to the wide release of low...

Performances of some low-cost counter electrode materials in CdS and CdSe quantum dot-sensitized solar cells.

Science.gov (United States)

Jun, Hieng Kiat; Careem, Mohamed Abdul; Arof, Abdul Kariem

2014-02-10

Different counter electrode (CE) materials based on carbon and Cu2S were prepared for the application in CdS and CdSe quantum dot-sensitized solar cells (QDSSCs). The CEs were prepared using low-cost and facile methods. Platinum was used as the reference CE material to compare the performances of the other materials. While carbon-based materials produced the best solar cell performance in CdS QDSSCs, platinum and Cu2S were superior in CdSe QDSSCs. Different CE materials have different performance in the two types of QDSSCs employed due to the different type of sensitizers and composition of polysulfide electrolytes used. The poor performance of QDSSCs with some CE materials is largely due to the lower photocurrent density and open-circuit voltage. The electrochemical impedance spectroscopy performed on the cells showed that the poor-performing QDSSCs had higher charge-transfer resistances and CPE values at their CE/electrolyte interfaces.

Direct Inkjet Printing of Silver Source/Drain Electrodes on an Amorphous InGaZnO Layer for Thin-Film Transistors.

Science.gov (United States)

Ning, Honglong; Chen, Jianqiu; Fang, Zhiqiang; Tao, Ruiqiang; Cai, Wei; Yao, Rihui; Hu, Shiben; Zhu, Zhennan; Zhou, Yicong; Yang, Caigui; Peng, Junbiao

2017-01-10

Printing technologies for thin-film transistors (TFTs) have recently attracted much interest owing to their eco-friendliness, direct patterning, low cost, and roll-to-roll manufacturing processes. Lower production costs could result if electrodes fabricated by vacuum processes could be replaced by inkjet printing. However, poor interfacial contacts and/or serious diffusion between the active layer and the silver electrodes are still problematic for achieving amorphous indium-gallium-zinc-oxide (a-IGZO) TFTs with good electrical performance. In this paper, silver (Ag) source/drain electrodes were directly inkjet-printed on an amorphous a-IGZO layer to fabricate TFTs that exhibited a mobility of 0.29 cm²·V -1 ·s -1 and an on/off current ratio of over 10⁵. To the best of our knowledge, this is a major improvement for bottom-gate top-contact a-IGZO TFTs with directly printed silver electrodes on a substrate with no pretreatment. This study presents a promising alternative method of fabricating electrodes of a-IGZO TFTs with desirable device performance.

Direct Inkjet Printing of Silver Source/Drain Electrodes on an Amorphous InGaZnO Layer for Thin-Film Transistors

Directory of Open Access Journals (Sweden)

Honglong Ning

2017-01-01

Full Text Available Printing technologies for thin-film transistors (TFTs have recently attracted much interest owing to their eco-friendliness, direct patterning, low cost, and roll-to-roll manufacturing processes. Lower production costs could result if electrodes fabricated by vacuum processes could be replaced by inkjet printing. However, poor interfacial contacts and/or serious diffusion between the active layer and the silver electrodes are still problematic for achieving amorphous indium–gallium–zinc–oxide (a-IGZO TFTs with good electrical performance. In this paper, silver (Ag source/drain electrodes were directly inkjet-printed on an amorphous a-IGZO layer to fabricate TFTs that exhibited a mobility of 0.29 cm2·V−1·s−1 and an on/off current ratio of over 105. To the best of our knowledge, this is a major improvement for bottom-gate top-contact a-IGZO TFTs with directly printed silver electrodes on a substrate with no pretreatment. This study presents a promising alternative method of fabricating electrodes of a-IGZO TFTs with desirable device performance.

Nanostructured ternary electrodes for energy-storage applications

KAUST Repository

Baby, Rakhi Raghavan

2012-02-13

A three-component, flexible electrode is developed for supercapacitors over graphitized carbon fabric, utilizing γ-MnO 2 nanoflowers anchored onto carbon nanotubes (γ-MnO 2/CNT) as spacers for graphene nanosheets (GNs). The three-component, composite electrode doubles the specific capacitance with respect to GN-only electrodes, giving the highest-reported specific capacitance (308 F g -1) for symmetric supercapacitors containing MnO 2 and GNs using a two-electrode configuration, at a scan rate of 20 mV s -1. A maximum energy density of 43 W h kg -1 is obtained for our symmetric supercapacitors at a constant discharge-current density of 2.5 A g -1 using GN-(γ-MnO 2/CNT)-nanocomposite electrodes. The fabricated supercapacitor device exhibits an excellent cycle life by retaining ≈90% of the initial specific capacitance after 5000 cycles. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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.

Method for developing cost estimates for generic regulatory requirements

International Nuclear Information System (INIS)

1985-01-01

The NRC has established a practice of performing regulatory analyses, reflecting costs as well as benefits, of proposed new or revised generic requirements. A method had been developed to assist the NRC in preparing the types of cost estimates required for this purpose and for assigning priorities in the resolution of generic safety issues. The cost of a generic requirement is defined as the net present value of total lifetime cost incurred by the public, industry, and government in implementing the requirement for all affected plants. The method described here is for commercial light-water-reactor power plants. Estimating the cost for a generic requirement involves several steps: (1) identifying the activities that must be carried out to fully implement the requirement, (2) defining the work packages associated with the major activities, (3) identifying the individual elements of cost for each work package, (4) estimating the magnitude of each cost element, (5) aggregating individual plant costs over the plant lifetime, and (6) aggregating all plant costs and generic costs to produce a total, national, present value of lifetime cost for the requirement. The method developed addresses all six steps. In this paper, we discuss on the first three

Tests of the presampler electrodes for module 0

CERN Document Server

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

2000-01-01

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

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....

Applying Quality Costs in a Software Development Environment

Directory of Open Access Journals (Sweden)

I.P. Hollingsworth

1999-05-01

Full Text Available This paper shows how Quality Costs can be a measure of software quality. The relationship between Quality Costs and other software quality metrics is briefly explained, and software development oriented versions of the two principal Quality Cost models are described. Finally the paper discusses the major issues involved in setting up a software Quality Cost programme. The concepts are based on previous research on Quality Costs in manufacturing, coupled with work on software metrics and the work currently being undertaken by the authors in a number of industries.

Potentiometric titration of molybdenum (6) with a cathode-polarized solid electrode

International Nuclear Information System (INIS)

Boeva, L.V.; Kimstach, V.A.; Bagdasarov, K.N.

1980-01-01

The possibility has been studied of using solid electrodes for potentiometric precipitation titration of molybdenum (6). A cathode-polarized electrode, electrochemically covered with a molybdenum blue layer, can be used as indicator electrode. The best results were obtained during deposition of molybdenum blue on a tungsten electrode. The mechanism of electrode work during titration has been investigated. A procedure has been developed of titration of molybdenum (6) in acid solutions using hydroxylamine N-aryl derivatives as titrants

Electro-catalytic biodiesel production from canola oil in methanolic and ethanolic solutions with low cost stainless steel and hybrid ion-exchange resin grafted electrodes

Science.gov (United States)

Allioux, Francois-Marie; Holland, Brendan J.; Kong, Lingxue; Dumée, Ludovic F.

2017-07-01

Biodiesel is a growing alternative to petroleum fuels and is produced by the catalysed transesterification of fats in presence of an alcohol base. Transesterification processes using homogeneous catalysts are considered to be amongst the most efficient methods but rely on the feedstock quality and low water content in order to avoid undesirable saponification reactions. In this work, the electro-catalytic conversion of canola oil to biodiesel in a 1% aqueous methanolic and ethanolic reaction mixture was performed without the addition of external catalyst or co-solvent. An inexpensive stainless steel electrode and a hybrid stainless steel electrode coated with an ion-exchange resin catalyst were used as cathode materials while the anode was composed of a plain carbon paper. The cell voltages were varied from 10 to 40 V and the reaction temperature maintained at 20 or 40°C. The canola oil conversion rates were found to be superior at 40°C without saponification reactions for cell voltages below 30 V. The conversion rates were as high as 87% for the hybrid electrode and 81% for the plain stainless steel electrode. This work could inspire new process development for the conversion of high water content feedstock for the production of second-generation biodiesel.

Electro-Catalytic Biodiesel Production from Canola Oil in Methanolic and Ethanolic Solutions with Low-Cost Stainless Steel and Hybrid Ion-Exchange Resin Grafted Electrodes

Directory of Open Access Journals (Sweden)

Francois-Marie Allioux

2017-07-01

Full Text Available Biodiesel is a growing alternative to petroleum fuels and is produced by the catalyzed transesterification of fats in presence of an alcohol base. Transesterification processes using homogeneous catalysts are considered to be among the most efficient methods but rely on the feedstock quality and low water content in order to avoid undesirable saponification reactions. In this work, the electro-catalytic conversion of canola oil to biodiesel in a 1% aqueous methanolic and ethanolic reaction mixture was performed without the addition of external catalyst or cosolvent. An inexpensive stainless steel (SS electrode and a hybrid SS electrode coated with an ion-exchange resin catalyst were used as cathode materials while the anode was composed of a plain carbon paper. The cell voltages were varied from 10 to 40 V and the reaction temperature maintained at 20 or 40°C. The canola oil conversion rates were found to be superior at 40°C without saponification reactions for cell voltages below 30 V. The conversion rates were as high as 87% for the hybrid electrode and 81% for the plain SS electrode. This work could inspire new process development for the conversion of high water content feedstock for the production of second-generation biodiesel.

Electrochemical characterisation of novel screen-printed carbon paste electrodes for voltammetric measurements

Directory of Open Access Journals (Sweden)

Sýs Milan

2017-01-01

Full Text Available This work is focused on the homemade screen-printed carbon paste electrode containing basically graphite powder (or glassy carbon powder, poly(vinylbchloride (PVC and paraffin oil. It compares the electrochemical properties of conventional carbon-based electrodes and prepared screen-printed carbon paste electrodes towards [Fe(CN6]3-/[Fe(CN6]4- and quinone/hydroquinone redox couples. Significant attention is paid to the development of the corresponding carbon inks, printing and the surface characterisation of the resulting electrodes by the scanning electron microscopy. An optimization consisted of the selection of the organic solvent, the optimal content of the used polymer with the chosen paste binder, appropriate isolation of electric contact, etc. Very similar properties of the prepared screen-printed electrodes, containing only corresponding carbon powder and 3 % PVC, with their conventional carbon paste electrode and glassy carbon-based electrodes, were observed during their characterisation. Screen-printed electrodes, with the pasting liquid usually provided satisfactory analytical data. Moreover, they can be used in the flow injection analysis and could undoubtedly replace the carbon paste grooved electrodes. It can be assumed that certain progress in the development of electrode materials was achieved by this research.

Room-temperature solution-processed and metal oxide-free nano-composite for the flexible transparent bottom electrode of perovskite solar cells

Science.gov (United States)

Lu, Haifei; Sun, Jingsong; Zhang, Hong; Lu, Shunmian; Choy, Wallace C. H.

2016-03-01

The exploration of low-temperature and solution-processed charge transporting and collecting layers can promote the development of low-cost and large-scale perovskite solar cells (PVSCs) through an all solution process. Here, we propose a room-temperature solution-processed and metal oxide-free nano-composite composed of a silver nano-network and graphene oxide (GO) flawless film for the transparent bottom electrode of a PVSC. Our experimental results show that the amount of GO flakes play a critical role in forming the flawless anti-corrosive barrier in the silver nano-network through a self-assembly approach under ambient atmosphere, which can effectively prevent the penetration of liquid or gaseous halides and their corrosion against the silver nano-network underneath. Importantly, we simultaneously achieve good work function alignment and surface wetting properties for a practical bottom electrode by controlling the degree of reduction of GO flakes. Finally, flexible PVSC adopting the room-temperature and solution-processed nano-composite as the flexible transparent bottom electrode has been demonstrated on a polyethylene terephthalate (PET) substrate. As a consequence, the demonstration of our room-temperature solution-processed and metal oxide-free flexible transparent bottom electrode will contribute to the emerging large-area flexible PVSC technologies.The exploration of low-temperature and solution-processed charge transporting and collecting layers can promote the development of low-cost and large-scale perovskite solar cells (PVSCs) through an all solution process. Here, we propose a room-temperature solution-processed and metal oxide-free nano-composite composed of a silver nano-network and graphene oxide (GO) flawless film for the transparent bottom electrode of a PVSC. Our experimental results show that the amount of GO flakes play a critical role in forming the flawless anti-corrosive barrier in the silver nano-network through a self

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.

Copper hexacyanoferrate battery electrodes with long cycle life and high power

KAUST Repository

Wessells, Colin D.; Huggins, Robert A.; Cui, Yi

2011-01-01

Short-term transients, including those related to wind and solar sources, present challenges to the electrical grid. Stationary energy storage systems that can operate for many cycles, at high power, with high round-trip energy efficiency, and at low cost are required. Existing energy storage technologies cannot satisfy these requirements. Here we show that crystalline nanoparticles of copper hexacyanoferrate, which has an ultra-low strain open framework structure, can be operated as a battery electrode in inexpensive aqueous electrolytes. After 40,000 deep discharge cycles at a 17g-C rate, 83% of the original capacity of copper hexacyanoferrate is retained. Even at a very high cycling rate of 83g-C, two thirds of its maximum discharge capacity is observed. At modest current densities, round-trip energy efficiencies of 99% can be achieved. The low-cost, scalable, room-temperature co-precipitation synthesis and excellent electrode performance of copper hexacyanoferrate make it attractive for large-scale energy storage systems. © 2011 Macmillan Publishers Limited. All rights reserved.

Copper hexacyanoferrate battery electrodes with long cycle life and high power

KAUST Repository

Wessells, Colin D.

2011-11-22

Short-term transients, including those related to wind and solar sources, present challenges to the electrical grid. Stationary energy storage systems that can operate for many cycles, at high power, with high round-trip energy efficiency, and at low cost are required. Existing energy storage technologies cannot satisfy these requirements. Here we show that crystalline nanoparticles of copper hexacyanoferrate, which has an ultra-low strain open framework structure, can be operated as a battery electrode in inexpensive aqueous electrolytes. After 40,000 deep discharge cycles at a 17g-C rate, 83% of the original capacity of copper hexacyanoferrate is retained. Even at a very high cycling rate of 83g-C, two thirds of its maximum discharge capacity is observed. At modest current densities, round-trip energy efficiencies of 99% can be achieved. The low-cost, scalable, room-temperature co-precipitation synthesis and excellent electrode performance of copper hexacyanoferrate make it attractive for large-scale energy storage systems. © 2011 Macmillan Publishers Limited. All rights reserved.

Self-positioned thin Pb-alloy base electrode Josephson junction

International Nuclear Information System (INIS)

Kuroda, K.; Sato, K.

1986-01-01

A self-positioned thin (SPOT) Pb-alloy base electrode Josephson junction is developed. In this junction, a 50-nm thick Pb-alloy base electrode is restricted within the junction region on an Nb underlayer using a self-alignment technique. The grain size reduction and the base electrode area restriction greatly improve thermal cycling stability, where the thermal cycling tests of 4000 proposed junctions (5 x 5 μm 2 ) showed no failures after 4000 cycles. In addition, the elimination of insulator layer stress on the Pb-alloy base electrode rectifies the problem of size effect on current density. The Nb underlayers also serve to isolate the Pb-alloy base electrodes from the resistors

Development of hospital data warehouse for cost analysis of DPC based on medical costs.

Science.gov (United States)

Muranaga, F; Kumamoto, I; Uto, Y

2007-01-01

To develop a data warehouse system for cost analysis, based on the categories of the diagnosis procedure combination (DPC) system, in which medical costs were estimated by DPC category and factors influencing the balance between costs and fees. We developed a data warehouse system for cost analysis using data from the hospital central data warehouse system. The balance data of patients who were discharged from Kagoshima University Hospital from April 2003 to March 2005 were determined in terms of medical procedure, cost per day and patient admission in order to conduct a drill-down analysis. To evaluate this system, we analyzed cash flow by DPC category of patients who were categorized as having malignant tumors and whose DPC category was reevaluated in 2004. The percentages of medical expenses were highest in patients with acute leukemia, non-Hodgkin's lymphoma, and particularly in patients with malignant tumors of the liver and intrahepatic bile duct. Imaging tests degraded the percentages of medical expenses in Kagoshima University Hospital. These results suggested that cost analysis by patient is important for hospital administration in the inclusive evaluation system using a case-mix index such as DPC.

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

Energy Technology Data Exchange (ETDEWEB)

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

2011-10-29

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

Pt-graphene electrodes for dye-sensitized solar cells

International Nuclear Information System (INIS)

Hoshi, Hajime; Tanaka, Shumpei; Miyoshi, Takashi

2014-01-01

Highlights: • Graphene films with Pt nanoparticles were prepared from commercial graphene. • Pt consumption can be reduced by using Pt-graphene films. • The film showed improved catalytic activity for the reaction I 3 − /I − . • The film can be used as the counter electrode of dye-sensitized solar cells (DSSCs). • The performance of DSSC was superior to that of the Pt electrode. - Abstract: A simple paste method for fabricating graphene films with Pt nanoparticles was developed. First, graphene pastes with Pt nanoparticles were prepared from commercially available graphene. The resulting films of graphene nanoplatelet aggregates with Pt nanoparticles (Pt-GNA) contained Pt nanoparticles distributed over the entire three-dimensional surface of the GNA. Then, the catalytic activity for the I 3 − /I − redox reaction was evaluated by cyclic voltammetry. The GNA electrode exhibited higher activity than a graphene nanoplatelet electrode because of its higher effective surface area. Addition of Pt nanoparticles to the electrodes improved the catalytic activity. In particular, a large Faradaic current for the I 3 − /I − reaction was observed for the Pt-GNA electrode. As the counter electrodes of dye-sensitized solar cells (DSSCs), their performance was consistent with the cyclic voltammetry results. In particular, the DSSC performance of the Pt-GNA electrode was superior to that of the Pt electrodes commonly used in DSSCs

Development of cost-benefit analysis system

International Nuclear Information System (INIS)

Shiba, Tsuyoshi; Mishima, Tetsuya; Yuyama, Tomonori; Suzuki, Atsushi

2001-01-01

In order to promote the FDR development, it is necessary to see various benefits brought by introduction of FBR from multiple perspectives and have a good grasp of such benefits quantitatively and an adequate R and D investment scale which corresponds with them. In this study, the structured prototype in the previous study was improved to be able to perform cost-benefit analysis. An example of improvement made in the system is addition of subroutine used for comparison between new energy and benefits brought by introduction of FBR with special emphasis on addition of logic for analyzing externality about the new energy. Other improvement examples are modification of the Conventional Year Expense Ratio method of power generation cost to Average Durable Year Cost method, addition of database function and turning input data into database, and reviewing idea on cost by the type of waste material and price of uranium. The cost-benefit analysis system was also restructured utilizing Microsoft ACCESS so that it should have a data base function. As the result of the improvement mentioned above, we expect that the improved cost-benefit analysis system will have higher generality than the system before; therefore, great deal of benefits brought by application of the system in the future is expected. (author)

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.

Low-Temperature Solution Processable Electrodes for Piezoelectric Sensors Applications

Science.gov (United States)

Tuukkanen, Sampo; Julin, Tuomas; Rantanen, Ville; Zakrzewski, Mari; Moilanen, Pasi; Lupo, Donald

2013-05-01

Piezoelectric thin-film sensors are suitable for a wide range of applications from physiological measurements to industrial monitoring systems. The use of flexible materials in combination with high-throughput printing technologies enables cost-effective manufacturing of custom-designed, highly integratable piezoelectric sensors. This type of sensor can, for instance, improve industrial process control or enable the embedding of ubiquitous sensors in our living environment to improve quality of life. Here, we discuss the benefits, challenges and potential applications of piezoelectric thin-film sensors. The piezoelectric sensor elements are fabricated by printing electrodes on both sides of unmetallized poly(vinylidene fluoride) film. We show that materials which are solution processable in low temperatures, biocompatible and environmental friendly are suitable for use as electrode materials in piezoelectric sensors.

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.

Discharge Simulation and Fabrication Process of an Aluminum Electrode and an Alumina Layer in AC-PDP

International Nuclear Information System (INIS)

Liu Qifa; Ding Guifu; Liu Chang; Wang Yan; Yan Qun

2013-01-01

A larger space PDP cell with patterned aluminum as the addressing electrode and alumina as the dielectric layer was proposed. The aluminum electrode and the alumina dielectric layer formed on the aluminum electrode were prepared separately by magnetron sputtering and anodic oxidation for plasma display panel. The properties of the aluminum electrode and the alumina dielectric layer were tested and can meet the demand of PDP application. The resistivity of the aluminum electrode is about 5 × 10 −8 Ω·m, the voltage withstanding of the alumina dielectric layer exceeds 100 V/μm and the relative permittivity is about 3.5 at 1 MHz. With this structure, the manufacturing cost of PDP could be cut and the addressing discharge formative delay is reduced by 0.67%, which is proved by PIC-MCC simulation. (plasma technology)

Pseudocapacitive and hierarchically ordered porous electrode materials supercapacitors

Science.gov (United States)

Saruhan, B.; Gönüllü, Y.; Arndt, B.

2013-05-01

Commercially available double layer capacitors store energy in an electrostatic field. This forms in the form of a double layer by charged particles arranged on two electrodes consisting mostly of active carbon. Such double layer capacitors exhibit a low energy density, so that components with large capacity according to large electrode areas are required. Our research focuses on the development of new electrode materials to realize the production of electrical energy storage systems with high energy density and high power density. Metal oxide based electrodes increase the energy density and the capacitance by addition of pseudo capacitance to the static capacitance present by the double layer super-capacitor electrodes. The so-called hybrid asymmetric cell capacitors combine both types of energy storage in a single component. In this work, the production routes followed in our laboratories for synthesis of nano-porous and aligned metal oxide electrodes using the electrochemical and sputter deposition as well as anodization methods will be described. Our characterisation studies concentrate on electrodes having redox metal-oxides (e.g. MnOx and WOx) and hierarchically aligned nano-porous Li-doped TiO2-NTs. The material specific and electrochemical properties achieved with these electrodes will be presented.

The evaluation of the polarization resistance in a tubular electrode and its application to the hydrogen electrode reaction

International Nuclear Information System (INIS)

Montero, M.A.; Marozzi, C.A.; Chialvo, M.R. Gennero de; Chialvo, A.C.

2007-01-01

An alternative method for the determination of the kinetic parameters involved in the elementary steps of the reaction mechanism of the hydrogen electrode reaction is proposed. It is based on the determination of the variation of the polarization resistance in a tubular platinum electrode with a laminar flow of electrolyte as a function of the activity of protons of the electrolyte solution. A theoretical expression that relates the experimental variables and the equilibrium polarization resistance is developed, which takes into account the current distribution along the electrode surface. The results are compared with others obtained previously, contributing to the verification of the kinetic mechanism through a completely different experimental procedure

Electrode structures of polymer-electrolyte fuel cells (PEFC). An electron microscopy approach to the characterization of the electrode structure of polymer electrolyte fuel cells

Energy Technology Data Exchange (ETDEWEB)

Scheiba, Frieder

2009-01-28

Polymer electrolyte fuel cells (PEFC) have a complex electrode structure, which usually consists of a catalyst, a catalyst support, a polymer electrolyte and pores. The materials used are largely amorphous, have a strong defective structure or have particle diameter of only a few nanometers. In the electrode the materials form highly disordered aggregated structures. Both aspects complicate a systematic structural analysis significantly. However, thorough knowledge of the electrode structure, is needed for systematic advancement of fuel cell technology and to obtain a better understanding of mass and charge carrier transport processes in the electrode. Because of the complex structure of the electrode, an approach based on the examination of electrode thin-sections by electron microscopy was chosen in this work to depicting the electrode structure experimentally. The present work presents these studies of the electrode structure. Some fundamental issues as the influence of the polymer electrolyte concentration and the polarity of the solvent used in the electrode manufacturing process were addressed. During the analysis particular attention was payed to the distribution and structure of the polymer electrolyte. A major problem to the investigations, were the low contrast between the polymer electrolyte, the catalyst support material and the embedding resin. Therefore, dilerent techniques were investigated in terms of their ability to improve the contrast. In this context, a computer-assisted acquisition procedure for energy filtered transmission electron microscopy (EF-TEM) was developed. The acquisition procedure permits a significant extension of the imageable sample. At the same time, it was possible to substantially reduce beam damage of the specimen and to minimize drift of the sample considerably. This allowed unambiguous identification of the polymer electrolyte in the electrode. It could further be shown, that the polymer electrolyte not only coats the

Developing a costing framework for palliative care services.

Science.gov (United States)

Mosoiu, Daniela; Dumitrescu, Malina; Connor, Stephen R

2014-10-01

Palliative care services have been reported to be a less expensive alternative to traditional treatment; however, little is known about how to measure the cost of delivering quality palliative care. The purpose of this project was to develop a standardized method for measuring the cost of palliative care delivery that could potentially be replicated in multiple settings. The project was implemented in three stages. First, an interdisciplinary group of palliative care experts identified standards of quality palliative care delivery in the inpatient and home care services. Surveys were conducted of government agencies and palliative care providers to identify payment practices and budgets for palliative care services. In the second phase, unit costs were defined and a costing framework was designed to measure inpatient and home-based palliative care unit costs. The final phase was advocacy for inclusion of calculated costs into the national funding system. In this project, a reliable framework for determining the cost of inpatient and home-based palliative care services was developed. Inpatient palliative care cost in Romania was calculated at $96.58 per day. Home-based palliative care was calculated at $30.37 per visit, $723.60 per month, and $1367.71 per episode of care, which averaged 45 visits. A standardized methodology and framework for costing palliative care are presented. The framework allows a country or provider of care to substitute their own local costs to generate cost information relevant to the health-care system. In Romania, this allowed the palliative care provider community to advocate for a consistent payment system. Copyright © 2014 American Academy of Hospice and Palliative Medicine. Published by Elsevier Inc. All rights reserved.

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).

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.)

[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

noise amplitude of EEG signals collected by the flexible electrodes was lower than that of the electrical signals collected by the gold cup electrodes. The flexible electrode could be taken into consideration as an alternative electrode for monitoring EOG and EEG signals, and the wireless portable sleep monitoring devices are to be further developed in the future.

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.

Coaxial fiber supercapacitor using all-carbon material electrodes.

Science.gov (United States)

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

2013-07-23

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

Development of electrochemical ion exchange electrodes for the treatment of wastes containing chromium or cesium ions

International Nuclear Information System (INIS)

Manosso, Helena Cristina

2006-01-01

Nowadays, environmental preservation using technologies that do not attack it, generating non-toxic residues and reduced volumes, has been discussed. Hazardous effluents, containing metals, as chromium, have been poured in the soils and rivers, degrading the water. Not different are the problems originated from some nuclear activities that generate wastes, as in chemical research laboratories. Although those wastes are not poured in the environment, sometimes they are inadequately stored, what can cause serious accidents. With the purpose of solving this problem, there are some techniques to waste treatment, between them there is the electrochemical ion exchange (EIX). EIX is an advanced process that has advantages over traditional ion exchange and the fact of using the electron as the only reagent, reduces the volume of the solution to be treated. This technique consists of development of an electrode, where an ion exchanger is physically incorporated in an electrode structure with a binder. In this study, cationic resin Amberlite CG-50 and zirconium phosphate have been chosen for the separation of chromium and cesium from waste, respectively. They were chosen because they present high chemical stability in oxidizing media and at ionizing radiation. The quantity of charcoal, graphite and binder used in formulation of electrode have been studied either. Before choosing the best electrode, it was verified sorption percentage of 99,3% for chromium and 99,8% for cesium. The greater advantage of this process is the total elution of chromium as much as cesium, without reagents addition, being possible to reuse the electrode without losing its capacity. Beside on the results, a continuous process for the wastes containing Cr and Cs, using a flux electrolytic cell (CELFLUX) of high retention capacity, was presented. The high efficiency of this cell for both retention and elution, leading to an important reduction of waste volume, and, every more, making possible the

Cost-effectiveness analysis of microdose clinical trials in drug development.

Science.gov (United States)

Yamane, Naoe; Igarashi, Ataru; Kusama, Makiko; Maeda, Kazuya; Ikeda, Toshihiko; Sugiyama, Yuichi

2013-01-01

Microdose (MD) clinical trials have been introduced to obtain human pharmacokinetic data early in drug development. Here we assessed the cost-effectiveness of microdose integrated drug development in a hypothetical model, as there was no such quantitative research that weighed the additional effectiveness against the additional time and/or cost. First, we calculated the cost and effectiveness (i.e., success rate) of 3 types of MD integrated drug development strategies: liquid chromatography-tandem mass spectrometry, accelerator mass spectrometry, and positron emission tomography. Then, we analyzed the cost-effectiveness of 9 hypothetical scenarios where 100 drug candidates entering into a non-clinical toxicity study were selected by different methods as the conventional scenario without MD. In the base-case, where 70 drug candidates were selected without MD and 30 selected evenly by one of the three MD methods, incremental cost-effectiveness ratio per one additional drug approved was JPY 12.7 billion (US$ 0.159 billion), whereas the average cost-effectiveness ratio of the conventional strategy was JPY 24.4 billion, which we set as a threshold. Integrating MD in the conventional drug development was cost-effective in this model. This quantitative analytical model which allows various modifications according to each company's conditions, would be helpful for guiding decisions early in clinical development.

Detection of mercury ions using L-cysteine modified electrodes by anodic stripping voltammetric method

Science.gov (United States)

Vanitha, M.; Balasubramanian, N.; Joni, I. Made; Panatarani, Camellia

2018-02-01

The detection of contaminants in wastewater is of massive importance in today's situation as they pose a serious threat to the environment as well as humans. One such vital contaminants is mercury and its compound, the reported mercury detectors grieve from low sensitivity, high cost and slow response. In the present work graphene based electrode material is developed for sensing mercury contaminants in wastewater using electrochemical technique. The synthesized material graphene oxide (GO) modified with L-Cysteine in presence of polyvinylpyrrolidone (PVP) as capping agent was characterized using SEM, TEM and Raman Spectroscopic analysis. It is ascertained from the morphological characterization that the nanocomposite exhibits a spherical morphology. The L-cysteine modified graphene oxide electrode is electrochemically characterized using redox couple [Fe(CN)63-/4-] and electrochemical impedance spectroscopic (EIS) analysis. Electrochemical sensing of Hg (II) ions in solution was done using Square wave anodic stripping voltammetry (SWASV). The incorporation of graphene significantly increases the sensitivity and selectivity towards mercury sensing.

Manufacturing and characterisation of electrode membrane assemblies for low temperature fuel cells; Herstellung und Charakterisierung von Membran-Elektroden-Einheiten fuer Niedertemperatur Brennstoffzellen

Energy Technology Data Exchange (ETDEWEB)

Kaz, Till

2008-08-22

The high cost for a Polymer electrolyte Fuel Cell (PEFC) System is still a barrier for commercial breakthrough, which cannot be compensated by the advantages of being pollution free, or nearly noiseless. The most effective way of saving costs is to reduce expensive materials, because the material costs only for the Membrane Electrode Assemblies (MEAs) is more than 70% of the total costs of a PEFC Stack. Within the MEA a main part of the costs is due to the catalyst. It is one of the main goals to decrease the catalyst loading by simultaneously increasing the performance or keeping it at least constant. Because in most electrodes only 20-50% of the catalyst in the electrodes is used, enlarging the electrochemical active area is one of the key problems of the PEFC. For being electrochemical active, the catalyst must be reachable for the gases, he must have a good ionic conductivity to the membrane and he must be attached to the Gas Diffusion Layer (GDL) by electron conductivity. In literature often an inferior ionic contact of the catalyst to the membrane is responsible for the low catalyst utilization. In the first part of the work, model electrodes with different kinds of catalysts and different amounts of electrolyte in the electrodes were investigated to explore the interrelationship between platinum and electrolyte content. Three different catalysts, unsupported Pt- black, 60 wt.% Pt carbon-supported and 20 wt.% Pt carbon-supported with an addition of Nafion powder of 0%, 20%, 40%, 60 wt.%, and 80 wt.% were used. The electrodes were prepared by spraying the electrode material with the DLR dry spray technique directly onto the membrane and then rolling them while hot. Because material solutions were not used, the structure of the electrodes are determinable and predictable. Numerous different in- and ex-situ characterization methods like impedance spectroscopy, U-i characteristic, cyclic voltammetry, proton conductivity measurements, half-cell measurements and

Methods for Specific Electrode Resistance Measurement during Transcranial Direct Current Stimulation

Science.gov (United States)

Khadka, Niranjan; Rahman, Asif; Sarantos, Chris; Truong, Dennis Q.; Bikson, Marom

2014-01-01

Background Transcranial Direct Current Stimulation (tDCS) is investigated to treat a wide range of neuropsychiatric disorders, for rehabilitation, and for enhancing cognitive performance. The monitoring of electrode resistance before and during tDCS is considered important for tolerability and safety, where an unusually high resistance is indicative of undesired electrode or poor skin contact conditions. Conventional resistance measurement methods do not isolate individual electrode resistance but rather measures overall voltage. Moreover, for HD-tDCS devices, cross talk across electrodes makes concurrent resistance monitoring unreliable. Objective We propose a novel method for monitoring of the individual electrode resistance during tDCS, using a super-position of direct current with a test-signal (low-intensity and low-frequency sinusoids with electrode– specific frequencies) and a single sentinel electrode (not used for DC). Methods To validate this methodology, we developed lumped-parameter models of two and multi-electrode tDCS. Approaches with and without a sentinel electrode were solved and underlying assumptions identified. Assumptions were tested and parameterized in healthy participants using forearm stimulation combining tDCS (2 mA) and sinusoidal test-signals (38 μA and 76 μA peak to peak at 1 Hz, 10 Hz, and 100 Hz) and an in vitro test (where varied electrode failure modes were created). DC and AC component voltages across the electrodes were compared and participants were asked to rate subjective pain. Results A sentinel electrode is required to isolate electrode resistance in a two-electrode tDCS system. For multi-electrode resistance tracking, cross talk was aggravated with electrode proximity and current/resistance mismatches, but could be corrected using proposed approaches. Average voltage and average pain scores were not significantly different across test current intensities and frequencies (two-way repeated measures ANOVA) indicating the

A microfluidic chip platform with electrochemical carbon nanotube electrodes for pre-clinical evaluation of antibiotics nanocapsules.

Science.gov (United States)

Hong, Chien-Chong; Wang, Chih-Ying; Peng, Kuo-Ti; Chu, I-Ming

2011-04-15

This paper presents a microfluidic chip platform with electrochemical carbon nanotube electrodes for preclinical evaluation of antibiotics nanocapsules. Currently, there has been an increasing interest in the development of nanocapsules for drug delivery applications for localized treatments of diseases. So far, the methods to detect antibiotics are liquid chromatography (LC), high performance liquid chromatography (HPLC), mass spectroscopy (MS). These conventional instruments are bulky, expensive, not ease of access, and talented operator required. In order to help the development of nanocapsules and understand drug release profile before planning the clinical experiments, it is important to set up a biosensing platform which could monitor and evaluate the real-time drug release profile of nanocapsules with high sensitivity and long-term measurement ability. In this work, a microfluidic chip platform with electrochemical carbon nanotube electrodes has been developed and characterized for rapid detection of antibiotics teicoplanin nanocapsules. Multi-walled carbon nanotubes are used to modify the gold electrode surfaces to enhance the performance of the electrochemical biosensors. Experimental results show that the limit of detection of the developed platform using carbon nanotubes electrodes is 0.1 μg/ml with a linear range from 1 μg/ml to 10 μg/ml. The sensitivity of the developed system is 0.023 mA ml/μg at 37°C. The drug release profile of teicoplanin nanocapsules in PBS shows that the antibiotics nanocapsules significantly increased the release of drug on the 4th day, measuring 0.4858 μg/(ml hr). The release of drug from the antibiotics nanocapsules reached 34.98 μg/ml on the 7th day. The results showed a similar trend compared with the measurement result using the HPLC instrument. Compared with the traditional HPLC measurements, the electrochemical sensing platform we developed measures results with increased flexibility in controlling experimental

Fabrication of Dry Electrode for Recording Bio-potentials