WorldWideScience

Sample records for addressable micro-fluidic electrode

  1. Micro-fluidic flow cells for studies of electrochemical reactions

    OpenAIRE

    Ingdal, Mats

    2014-01-01

    Micro fluidic flow cells (MFFCs) are a relatively new technique for characterization of electrochemical reactions. This work includes both techniques for manufacturing the cells and electrochemical characterization of them.Improvements to a previously established procedure for the manufacturing MFFCs included change of template for PDMS-masters from glass slides to silicon wafers and the change from electrodes consisting of titanium gold and platinum to only titanium and platinum. The changes...

  2. A Coupled Cavity Micro Fluidic Dye Ring Laser

    OpenAIRE

    Gersborg-Hansen, M.; Balslev, S.; Mortensen, N. A.; Kristensen, A.

    2004-01-01

    We present a laterally emitting, coupled cavity micro fluidic dye ring laser, suitable for integration into lab-on-a-chip micro systems. The micro-fluidic laser has been successfully designed, fabricated, characterized and modelled. The resonator is formed by a micro-fluidic channel bounded by two isosceles triangle mirrors. The micro-fluidic laser structure is defined using photo lithography in 10 microns thick SU-8 polymer on a glass substrate. The micro fluidic channel is sealed by a glass...

  3. Integration of biological ion channels onto optically addressable micro-fluidic electrode arrays for single molecule characterization.

    Energy Technology Data Exchange (ETDEWEB)

    Brozik, Susan Marie; Frink, Laura J. Douglas; Bachand, George David; Keller, David J. (University of New Mexico, Albuquerque, NM); Patrick, Elizabeth L.; Marshall, Jason A. (University of New Mexico, Albuquerque, NM); Ortiz, Theodore P. (University of New Mexico, Albuquerque, NM); Meyer, Lauren A. (University of New Mexico, Albuquerque, NM); Davis, Ryan W. (University of New Mexico, Albuquerque, NM); Brozik, James A. (University of New Mexico, Albuquerque, NM); Flemming, Jeb Hunter

    2004-12-01

    The challenge of modeling the organization and function of biological membranes on a solid support has received considerable attention in recent years, primarily driven by potential applications in biosensor design. Affinity-based biosensors show great promise for extremely sensitive detection of BW agents and toxins. Receptor molecules have been successfully incorporated into phospholipid bilayers supported on sensing platforms. However, a collective body of data detailing a mechanistic understanding of membrane processes involved in receptor-substrate interactions and the competition between localized perturbations and delocalized responses resulting in reorganization of transmembrane protein structure, has yet to be produced. This report describes a systematic procedure to develop detailed correlation between (recognition-induced) protein restructuring and function of a ligand gated ion channel by combining single molecule fluorescence spectroscopy and single channel current recordings. This document is divided into three sections: (1) reported are the thermodynamics and diffusion properties of gramicidin using single molecule fluorescence imaging and (2) preliminary work on the 5HT{sub 3} serotonin receptor. Thirdly, we describe the design and fabrication of a miniaturized platform using the concepts of these two technologies (spectroscopic and single channel electrochemical techniques) for single molecule analysis, with a longer term goal of using the physical and electronic changes caused by a specific molecular recognition event as a transduction pathway in affinity based biosensors for biotoxin detection.

  4. A Coupled Cavity Micro Fluidic Dye Ring Laser

    CERN Document Server

    Gersborg-Hansen, M; Mortensen, N A; Kristensen, A

    2004-01-01

    We present a laterally emitting, coupled cavity micro fluidic dye ring laser, suitable for integration into lab-on-a-chip micro systems. The micro-fluidic laser has been successfully designed, fabricated, characterized and modelled. The resonator is formed by a micro-fluidic channel bounded by two isosceles triangle mirrors. The micro-fluidic laser structure is defined using photo lithography in 10 microns thick SU-8 polymer on a glass substrate. The micro fluidic channel is sealed by a glass lid, using PMMA adhesive bonding. The laser is characterized using the laser dye Rhodamine 6G dissolved in ethanol or ethylene glycol as the active gain medium, which is pumped through the micro-fluidic channel and laser resonator. The dye laser is optically pumped normal to the chip plane at 532 nm by a pulsed, frequency doubled Nd:YAG laser and lasing is observed with a threshold pump pulse energy flux of around 55 micro-Joule/square-milimeter. The lasing is multi-mode, and the laser has switchable output coupling into...

  5. Light addressable gold electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Khalid, Waqas

    2011-07-01

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

  6. pH-Sensitive Hydrogel for Micro-Fluidic Valve

    OpenAIRE

    Zhengzhi Yang; Haiyan Miao; Zhiwei Ding; Somsak Swaddiwudhipong; Yan Zhang; Zishun Liu

    2012-01-01

    The deformation behavior of a pH-sensitive hydrogel micro-fluidic valve system is investigated using inhomogeneous gel deformation theory, in which the fluid-structure interaction (FSI) of the gel solid and fluid flow in the pipe is considered. We use a finite element method with a well adopted hydrogel constitutive equation, which is coded in commercial software, ABAQUS, to simulate the hydrogel valve swelling deformation, while FLUENT is adopted to model the fluid flow in the pipe of the hy...

  7. pH-Sensitive Hydrogel for Micro-Fluidic Valve

    Directory of Open Access Journals (Sweden)

    Zhengzhi Yang

    2012-07-01

    Full Text Available The deformation behavior of a pH-sensitive hydrogel micro-fluidic valve system is investigated using inhomogeneous gel deformation theory, in which the fluid-structure interaction (FSI of the gel solid and fluid flow in the pipe is considered. We use a finite element method with a well adopted hydrogel constitutive equation, which is coded in commercial software, ABAQUS, to simulate the hydrogel valve swelling deformation, while FLUENT is adopted to model the fluid flow in the pipe of the hydrogel valve system. The study demonstrates that FSI significantly affects the gel swelling deformed shapes, fluid flow pressure and velocity patterns. FSI has to be considered in the study on fluid flow regulated by hydrogel microfluidic valve. The study provides a more accurate and adoptable model for future design of new pH-sensitive hydrogel valves, and also gives a useful guideline for further studies on hydrogel fluidic applications.

  8. A High-Voltage Integrated Circuit Engine for a Dielectrophoresis-based Programmable Micro-Fluidic Processor

    Science.gov (United States)

    Current, K. Wayne; Yuk, Kelvin; McConaghy, Charles; Gascoyne, Peter R. C.; Schwartz, Jon A.; Vykoukal, Jody V.; Andrews, Craig

    2010-01-01

    A high-voltage (HV) integrated circuit has been demonstrated to transport droplets on programmable paths across its coated surface. This chip is the engine for a dielectrophoresis (DEP)-based micro-fluidic lab-on-a-chip system. This chip creates DEP forces that move and help inject droplets. Electrode excitation voltage and frequency are variable. With the electrodes driven with a 100V peak-to-peak periodic waveform, the maximum high-voltage electrode waveform frequency is about 200Hz. Data communication rate is variable up to 250kHz. This demonstration chip has a 32×32 array of nominally 100V electrode drivers. It is fabricated in a 130V SOI CMOS fabrication technology, dissipates a maximum of 1.87W, and is about 10.4 mm × 8.2 mm. PMID:23989241

  9. Computation of transient flow rates in passive pumping micro-fluidic systems

    OpenAIRE

    Chen, I-Jane; Eckstein, Eugene C.; Lindner, Ernő

    2008-01-01

    Motion in micro-channels of passive flow micro-fluidic systems can be controlled by proper design and estimated by careful modeling. We report on methods to describe the flow rate as function of time in a passive pump driven micro-fluidic systems. The model considers the surface energy present in small droplets, which prompts their shrinkage and induces flow. The droplet geometries are controlled by the micro-fluidic system geometry and hydrophilicity of the droplet channel contact area so th...

  10. Portable integrated micro-fluidic platform for the monitoring and detection of nitrite

    OpenAIRE

    Czugala, Monika; Fay, Cormac; O'Connor, Noel E.; Corcoran, Brian; Benito-Lopez, Fernando; Diamond, Dermot

    2013-01-01

    A wireless, portable integrated micro-fluidic platform is proposed and applied for the determination of nitrite anions in water. The colourimetric analysis of nitrite is based on the Griess reagent, and the colour intensity of nitrite Griess reagent complex is detected using a low cost Paired Emitter Detector Diode technique. The micro-fluidic device employed a photoswitchable micro-valve, controlled by white light and generated using a light emitting diode. This low-cost and low-power detect...

  11. Manufacture of micro fluidic devices by laser welding using thermal transfer printing techniques

    Science.gov (United States)

    Klein, R.; Klein, K. F.; Tobisch, T.; Thoelken, D.; Belz, M.

    2016-03-01

    Micro-fluidic devices are widely used today in the areas of medical diagnostics and drug research, as well as for applications within the process, electronics and chemical industry. Microliters of fluids or single cell to cell interactions can be conveniently analyzed with such devices using fluorescence imaging, phase contrast microscopy or spectroscopic techniques. Typical micro-fluidic devices consist of a thermoplastic base component with chambers and channels covered by a hermetic fluid and gas tight sealed lid component. Both components are usually from the same or similar thermoplastic material. Different mechanical, adhesive or thermal joining processes can be used to assemble base component and lid. Today, laser beam welding shows the potential to become a novel manufacturing opportunity for midsize and large scale production of micro-fluidic devices resulting in excellent processing quality by localized heat input and low thermal stress to the device during processing. For laser welding, optical absorption of the resin and laser wavelength has to be matched for proper joining. This paper will focus on a new approach to prepare micro-fluidic channels in such devices using a thermal transfer printing process, where an optical absorbing layer absorbs the laser energy. Advantages of this process will be discussed in combination with laser welding of optical transparent micro-fluidic devices.

  12. A micro-fluidic study of whole blood behaviour on PMMA topographical nanostructures

    Directory of Open Access Journals (Sweden)

    Tsud Nataliya

    2008-02-01

    Full Text Available Abstract Background Polymers are attractive materials for both biomedical engineering and cardiovascular applications. Although nano-topography has been found to influence cell behaviour, no established method exists to understand and evaluate the effects of nano-topography on polymer-blood interaction. Results We optimized a micro-fluidic set-up to study the interaction of whole blood with nano-structured polymer surfaces under flow conditions. Micro-fluidic chips were coated with polymethylmethacrylate films and structured by polymer demixing. Surface feature size varied from 40 nm to 400 nm and feature height from 5 nm to 50 nm. Whole blood flow rate through the micro-fluidic channels, platelet adhesion and von Willebrand factor and fibrinogen adsorption onto the structured polymer films were investigated. Whole blood flow rate through the micro-fluidic channels was found to decrease with increasing average surface feature size. Adhesion and spreading of platelets from whole blood and von Willebrand factor adsorption from platelet poor plasma were enhanced on the structured surfaces with larger feature, while fibrinogen adsorption followed the opposite trend. Conclusion We investigated whole blood behaviour and plasma protein adsorption on nano-structured polymer materials under flow conditions using a micro-fluidic set-up. We speculate that surface nano-topography of polymer films influences primarily plasma protein adsorption, which results in the control of platelet adhesion and thrombus formation.

  13. A Programmable MicroFluidic Processor: Integrated and Hybrid Solutions

    Energy Technology Data Exchange (ETDEWEB)

    Rose, K A

    2002-05-10

    The Programmable Fluidic Processor (PFP), a device conceived of by researchers at MD Anderson Cancer Center, is a reconfigurable and programmable bio-chemical analysis system designed for handheld operation in a variety of applications. Unlike most microfluidic systems which utilize channels to control fluids, the PFP device is a droplet-based system. The device is based on dielectrophoresis; a fluid transport phenomenon that utilizes mismatched polarizability between a droplet and its medium to induce droplet mobility. In the device, sample carrying droplets are polarized by an array of electrodes, individually addressable by subsurface microelectronics. My research focused on the development of a polymer-based microfluidic injection system for injecting these droplets onto the electrode array. The first of two device generations fabricated at LLNL was designed using extensive research and modeling performed by MD Anderson and Coventor. Fabricating the first generation required several iterations and design changes in order to generate an acceptable device for testing. Difficulties in planar fabrication of the fluidic system and a narrow channel design necessitated these changes. The second generation device incorporated modifications of the previous generation and improved on deficiencies discovered during experimentation with the initial device. Extensive modeling of the injection channels and fluid storage chamber also aided in redesigning the device's microfluidic system. A micromolding technique with interlocking features enabled precise alignments and dimensional control, critical requirements for device optimization. Fabrication of a final device will be fully integrated with the polymer-based microfluidics bonded directly to the silicon-based microelectronics. The optimized design and process flow developed in the trial generations will readily transfer to this approach.

  14. Combination of Micro-fluidic Chip with Fluorescence Correlation Spectroscopy for Single Molecule Detection

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A single molecule detection technique was developed by the combination of a single channel poly (dimethylsiloxane)/glass micro-fluidic chip and fluorescence correlation spectroscopy (FCS). This method was successfully used to determine the proportion of two model components in the mixture containing fluorescein and the rhodamine-green succinimidyl ester.

  15. Micro-patterning and actuation of phosphonium-based photo-responsive ionogels for micro-fluidic applications

    OpenAIRE

    Blin, Candice; Byrne, Robert; Diamond, Dermot; Benito-Lopez, Fernando

    2011-01-01

    The concept of “Micro-total-analysis-Systems” or “Lab-on-chip” has emerged over the past 20-years but, despite of the fact their incredible potential to revolutionise analytical science few outputs have reached the market so far[1]. Moreover, important issues like durability, disposability and cost of manufacture slow down the process of the integration of micro-fluidics into commercially relevant analytical products[2]. We believe that the next breakthroughs on micro-fluidic technology will ...

  16. Stimuli-responsive materials: developing integrated opto-molecular systems as sensors and actuators in micro-fluidic devices

    OpenAIRE

    Florea, Larisa

    2013-01-01

    Micro-fluidic platforms have been conferred with inherent optical sensing capabilities by coating the walls of micro-fluidic channels or micro-capillaries with stimuli-responsive materials. These adaptive materials respond optically to environmental stimuli, such as changes in pH, solvent polarity, the presence of certain metal ions and light. This approach confers sensing capabilities along the entire length of the coated micro-channel or micro-capillary. Adaptive coatings based on two types...

  17. Micro-Fluidic Dye Ring Laser - Experimental Tuning of the Wavelength and Numerical Simulation of the Cavity Modes

    DEFF Research Database (Denmark)

    Gersborg-Hansen, Morten; Balslev, Søren; Mortensen, Niels Asger;

    2006-01-01

    We demonstrate wavelength tuning of a micro-fluidic dye ring laser. Wavelength tunability is obtained by controlling the liquid dye concentration. The device performance is modelled by FEM simulations supporting a ray-tracing view.......We demonstrate wavelength tuning of a micro-fluidic dye ring laser. Wavelength tunability is obtained by controlling the liquid dye concentration. The device performance is modelled by FEM simulations supporting a ray-tracing view....

  18. Fabrication of Biochips with Micro Fluidic Channels by Micro End-milling and Powder Blasting

    OpenAIRE

    Dong Sam Park; Tae Il Seo; Dae Jin Yun

    2008-01-01

    For microfabrications of biochips with micro fluidic channels, a large number of microfabrication techniques based on silicon or glass-based Micro-Electro-Mechanical System (MEMS) technologies were proposed in the last decade. In recent years, for low cost and mass production, polymer-based microfabrication techniques by microinjection molding and micro hot embossing have been proposed. These techniques, which require a proper photoresist, mask, UV light exposure, developing, and electroplati...

  19. Research of Confocal Laser Induced Fluorescence Detection System for Micro-fluidic Chip

    Institute of Scientific and Technical Information of China (English)

    FENG Jin-yuan; WANG Xiu-hua; ZHANG Hua-feng

    2007-01-01

    The characteristics such as signal noise ratio(SNR)[1-2] and sensitivity of the fluorescence detection system for micro-fluidic chip influence the performance of the whole system extremely.The confocal laser induced fluorescence detection system is presented.Based on the debugging of optical and circuit modules, the results of detecting the samples are given and analyzed theoretically,and the improved project is put forward.

  20. Characterization of printable cellular micro-fluidic channels for tissue engineering.

    Science.gov (United States)

    Zhang, Yahui; Yu, Yin; Chen, Howard; Ozbolat, Ibrahim T

    2013-06-01

    Tissue engineering has been a promising field of research, offering hope of bridging the gap between organ shortage and transplantation needs. However, building three-dimensional (3D) vascularized organs remains the main technological barrier to be overcome. One of the major challenges is the inclusion of a vascular network to support cell viability in terms of nutrients and oxygen perfusion. This paper introduces a new approach to the fabrication of vessel-like microfluidic channels that has the potential to be used in thick tissue or organ fabrication in the future. In this research, we investigate the manufacturability of printable micro-fluidic channels, where micro-fluidic channels support mechanical integrity as well as enable fluid transport in 3D. A pressure-assisted solid freeform fabrication platform is developed with a coaxial needle dispenser unit to print hollow hydrogel filaments. The dispensing rheology is studied, and effects of material properties on structural formation of hollow filaments are analyzed. Sample structures are printed through the developed computer-controlled system. In addition, cell viability and gene expression studies are presented in this paper. Cell viability shows that cartilage progenitor cells (CPCs) maintained their viability right after bioprinting and during prolonged in vitro culture. Real-time PCR analysis yielded a relatively higher expression of cartilage-specific genes in alginate hollow filament encapsulating CPCs, compared with monolayer cultured CPCs, which revealed that printable semi-permeable micro-fluidic channels provided an ideal environment for cell growth and function. PMID:23458889

  1. Micro-fluidic module for blood cell separation for gene expression radiobiological assays

    International Nuclear Information System (INIS)

    Advances in molecular techniques have improved discovery of biomarkers associated with radiation exposure. Gene expression techniques have been demonstrated as effective tools for biodosimetry, and different assay platforms with different chemistries are now available. One of the main challenges is to integrate the sample preparation processing of these assays into micro-fluidic platforms to be fully automated for point-of-care medical countermeasures in the case of a radiological event. Most of these assays follow the same workflow processing that comprises first the collection of blood samples followed by cellular and molecular sample preparation. The sample preparation is based on the specific reagents of the assay system and depends also on the different subsets of cells population and the type of biomarkers of interest. In this article, the authors present a module for isolation of white blood cells from peripheral blood as a prerequisite for automation of gene expression assays on a micro-fluidic cartridge. For each sample condition, the gene expression platform can be adapted to suit the requirements of the selected assay chemistry (authors)

  2. Fabrication of Biochips with Micro Fluidic Channels by Micro End-milling and Powder Blasting

    Directory of Open Access Journals (Sweden)

    Dong Sam Park

    2008-02-01

    Full Text Available For microfabrications of biochips with micro fluidic channels, a large number of microfabrication techniques based on silicon or glass-based Micro-Electro-Mechanical System (MEMS technologies were proposed in the last decade. In recent years, for low cost and mass production, polymer-based microfabrication techniques by microinjection molding and micro hot embossing have been proposed. These techniques, which require a proper photoresist, mask, UV light exposure, developing, and electroplating as a preprocess, are considered to have some problems. In this study, we propose a new microfabrication technology which consists of micro end-milling and powder blasting. This technique could be directly applied to fabricate the metal mold without any preprocesses. The metal mold with micro-channels is machined by micro end-milling, and then, burrs generated in the end-milling process are removed by powder blasting. From the experimental results, micro end-milling combined with powder blasting could be applied effectively for fabrication of the injection mold of biochips with micro fluidic channels.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-12-15

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

  4. Manipulating fluids: Advances in micro-fluidics, opto-fluidics and fluidic self assembly

    Science.gov (United States)

    Vyawahare, Saurabh

    This dissertation describes work in three inter-related areas---micro-fluidics, opto-fluidics and fluidic self-assembly. Micro-fluidics has gotten a boost in recent years with the development of multilayered elastomeric devices made of poly (dimethylsiloxane) (PDMS), allowing active elements like valves and pumps. However, while PDMS has many advantages, it is not resistant to organic solvents. New materials and/or new designs are needed for solvent resistance. I describe how novel fluorinated elastomers can replace PDMS when combined with the three dimensional (3-D) solid printing. I also show how another 3-D fabrication method, multilayer photo-lithography, allows for fabrication of devices integrating filters. In general, 3-D fabrications allow new kinds of micro-fluidic devices to be made that would be impossible to emulate with two dimensional chips. In opto-fluidics, I describe a number of experiments with quantum dots both inside and outside chips. Inside chips, I manipulate quantum dots using hydrodynamic focusing to pattern fine lines, like a barcode. Outside chips, I describe our attempts to create quantum dot composites with micro-spheres. I also show how evaporated gold films and chemical passivation can then be used to enhance the emission of quantum dots. Finally, within fluids, self assembly is an attractive way to manipulate materials, and I provide two examples: first, a DNA-based energy transfer molecule that relies on quantum mechanics and self-assembles inside fluids. This kind of molecular photonics mimics parts of the photosynthetic apparatus of plants and bacteria. The second example of self-assembly in fluids describes a new phenomena---the surface tension mediated self assembly of particles like quantum dots and micro-spheres into fine lines. This self assembly by capillary flows can be combined with photo-lithography, and is expected to find use in future nano- and micro-fabrication schemes. In conclusion, advances in fludics, integrating

  5. Investigation of the dye concentration influence on the lasing wavelength and threshold for a micro-fluidic dye laser

    DEFF Research Database (Denmark)

    Helbo, Bjarne; Kragh, Søren; Kjeldsen, B.G.;

    2003-01-01

    We investigate a micro-fluidic dye laser, which can be integrated with polymer-based lab-on-a-chip microsystems without further processing steps. A simple rate-equation model is used to predict the lasing threshold. The laser device is characterised using the laser dye Rhodamine 6G dissolved...

  6. Fundamental Study on New Micro Fluidic Drive Method Based on Liquid Crystalline Backflow

    Directory of Open Access Journals (Sweden)

    Chunbo Liu

    2012-11-01

    Full Text Available In this study, we propose a one-dimensional simple model for predicting the performance of the new micro fluidic drive and then we have a research of the control method based on liquid crystalline backflow by combining the motion of the upper plate of a liquid crystal cell and the flow of a liquid crystal. Comparison of the numerical predictions and the experimental results shows that the proposed model is useful to predict qualitatively the motion the upper plate. The drive efficiency is affected by applied voltage, the frequency, the duty ratio and the gap of the cell. The ideal drive quality can be achieved when the rotation range of the molecules at the center of the cell is controlled within 50-80°.

  7. Silicon micro-fluidic cooling for NA62 GTK pixel detectors

    CERN Document Server

    Romagnoli, G; Brunel, B; Catinaccio, A; Degrange, J; Mapelli, A; Morel, M; Noel, J; Petagna, P

    2015-01-01

    Silicon micro-channel cooling is being studied for efficient thermal management in application fields such as high power computing and 3D electronic integration. This concept has been introduced in 2010 for the thermal management of silicon pixel detectors in high energy physics experiments. Combining the versatility of standard micro-fabrication processes with the high thermal efficiency typical of micro-fluidics, it is possible to produce effective thermal management devices that are well adapted to different detector configurations. The production of very thin cooling devices in silicon enables a minimization of material of the tracking sensors and eliminates mechanical stresses due to the mismatch of the coefficient of thermal expansion between detectors and cooling systems. The NA62 experiment at CERN will be the first high particle physics experiment that will install a micro-cooling system to perform the thermal management of the three detection planes of its Gigatracker pixel detector.

  8. Shear wave attenuation and micro-fluidics in water-saturated sand and glass beads.

    Science.gov (United States)

    Chotiros, Nicholas P; Isakson, Marcia J

    2014-06-01

    An improvement in the modeling of shear wave attenuation and speed in water-saturated sand and glass beads is introduced. Some dry and water-saturated materials are known to follow a constant-Q model in which the attenuation, expressed as Q(-1), is independent of frequency. The associated loss mechanism is thought to lie within the solid frame. A second loss mechanism in fluid-saturated porous materials is the viscous loss due to relative motion between pore fluid and solid frame predicted by the Biot-Stoll model. It contains a relaxation process that makes the Q(-1) change with frequency, reaching a peak at a characteristic frequency. Examination of the published measurements above 1 kHz, particularly those of Brunson (Ph.D. thesis, Oregon State University, Corvalis, 1983), shows another peak, which is explained in terms of a relaxation process associated with the squirt flow process at the grain-grain contact. In the process of deriving a model for this phenomenon, it is necessary to consider the micro-fluidic effects associated with the flow within a thin film of water confined in the gap at the grain-grain contact and the resulting increase in the effective viscosity of water. The result is an extended Biot model that is applicable over a broad band of frequencies. PMID:24907791

  9. Disposable micro-fluidic biosensor array for online parallelized cell adhesion kinetics analysis on quartz crystal resonators

    DEFF Research Database (Denmark)

    Cama, G.; Jacobs, T.; Dimaki, Maria;

    2010-01-01

    In this contribution we present a new disposable micro-fluidic biosensor array for the online analysis of adherent Madin Darby canine kidney (MDCK-II) cells on quartz crystal resonators (QCRs). The device was conceived for the parallel cultivation of cells providing the same experimental conditions...... among all the sensors of the array. As well, dedicated sensor interface electronics were developed and optimized for fast spectra acquisition of all 16 QCRs with a miniaturized impedance analyzer. This allowed performing cell cultivation experiments for the observation of fast cellular reaction kinetics...... with focus on the comparison of the resulting sensor signals influenced by different cell distributions on the sensor surface. To prove the assumption of equal flow circulation within the symmetric micro-channel network and support the hypothesis of identical cultivation conditions for the cells living above...

  10. Design of an optical and micro-fluidic sensor for concentration measurement by photo-thermal effect

    International Nuclear Information System (INIS)

    This work has been done in the context of fuel reprocessing in the nuclear industry. In fact, the handling of nuclear waste is one of the major issues in the nuclear industry. Its implications reach from economical to political to ecological dimensions. Since used nuclear fuel consists of 97% of recyclable substances, many countries have chosen to reprocess used fuel, not only for economical reasons but also to limit the quantity of nuclear waste. The most widely employed extraction technique is the PUREX process where the used fuel is diluted in nitric acid. The recyclable compounds can then be extracted by solvent techniques. Such processes need to be monitored crucially. However, nowadays, the process supervision is carried out by manually sampling the radioactive effluents and analyzing them in external laboratories. Not only prone to potential risks, this approach is little responsive and produces radio-toxic samples that cannot be reintroduced in the nuclear fuel cycle. In this study, we therefore present the developpement of a micro-fluidic glass sensor, based on the detection of a photothermal effect induced in the sample fluid. Micro-fluidic allows fluid handling on a microliter-scale and can therefore significantly reduce the sample volume and thereby the radio-toxicity of the analyzed fluids. Photothermal spectrometry is well suited for small-scale sample analysis since its sensitivity does not rely on the length of optical interaction with the analyte. The photothermal effect is a local refractive index variation due to the absorption of photons by the analyte species which are contained in the sample. On the sensor chip, the index refraction change is being sensed by an integrated Young interferometer made by ion-exchange in glass. The probed volume in the channel was (33.5± 3.5) pl. The interferometric system can sense refractive index changes as low as Δn(min)=7.5*10-6, allowing to detect a minimum concentration of cobalt(II) in ethanol c

  11. The thermal-hydraulic for the new technologies: the micro-fluidics; La thermohydraulique au service des nouvelles technologies: la microfluidique

    Energy Technology Data Exchange (ETDEWEB)

    Crecy, F. de; Gruss, A.; Bricard, A.; Excoffon, J

    2000-07-01

    The micro-fluidics can be defined as the fluid flow in little canals. This scale offers a great interest for the biotechnology type. In this paper, the authors present this fluids form and detail the researches performed at the Department of Physics and Thermal-hydraulics of the CEA, in the domain of the physical properties characterization and of the numerical two-phase direct simulation. (A.L.B.)

  12. An all-glass 12 μm ultra-thin and flexible micro-fluidic chip fabricated by femtosecond laser processing.

    Science.gov (United States)

    Yalikun, Yaxiaer; Hosokawa, Yoichiroh; Iino, Takanori; Tanaka, Yo

    2016-07-01

    This study investigated and established a method, using femtosecond laser processing, to fabricate a 100%-glass-based 12 μm ultra-thin and flexible micro-fluidic chip. First we investigated the suitable pulse energy of the laser to fabricate ultra-thin glass sheets and then we fabricated a prototype glass micro-fluidic chip. Two 1 mm-in-diameter orifices for facilitating alignment in the bonding step and one channel with a width of 20 μm and a length of 25 mm were fabricated in a 4 μm thickness ultra-thin glass sheet using the femtosecond laser; this forms layer 2 in the completed device. Next, the glass sheet with the channel was sandwiched between another glass sheet having an inlet hole and an outlet hole (layer 1) and a base glass sheet (layer 3); the three sheets were bonded to each other, resulting in a flexible, 100%-glass micro-fluidic chip with a thickness of approximately 12 μm and a weight of 3.6 mg. The basic function of the glass micro-fluidic chip was confirmed by flowing 1 and 2 μm in-diameter bead particles through the channel. The fabrication method clearly scales down the thickness limitation of flexible glass devices and offers a possible element technology for fabricating ultra-thin glass devices that can be applied to convection-enhanced delivery, implantable medical devices, wearable devices, and high-resolution imaging of small biological objects such as bacteria and proteins in the channel. PMID:27225521

  13. Measurement of Solution Impedance with Micro-Fluidic Chip%基于微流控芯片的液体电导测量

    Institute of Scientific and Technical Information of China (English)

    胥飞; Md Shehadul Islam

    2012-01-01

    A conductance micro-fluidic chip was fabricated by electrochemistry corrosion. Based on the traditional fabrication method of micro-fluidic chip, thin brass wire is etched and broken into two elec- trodes for impedance measurement. Conductance of polystyrene beads solutions with densities of 21.0 %, 28. 1%, 37.50% and 50% are measured with the micro-fluidic chip. The measured results conform to the theory, showing effectiveness of the chip in liquid conductance measurement.%在传统微流控芯片制作方法的基础上,利用电化学腐蚀来制作电导式微流控芯片。对浓度分别为21.0%、28.1%、37.5%、50%的聚苯乙烯溶于去离子水的微粒混悬液进行实验测量,实验表明,该芯片测量与理论基本符合,芯片适用于液体溶液的阻抗测量。

  14. All-organic electrostrictive polymer composites with low driving electrical voltages for micro-fluidic pump applications

    Science.gov (United States)

    Le, Minh Quyen; Capsal, Jean-Fabien; Galineau, Jérémy; Ganet, Florent; Yin, Xunqian; Yang, Mingchia (Dawn); Chateaux, Jean-François; Renaud, Louis; Malhaire, Christophe; Cottinet, Pierre-Jean; Liang, Richard

    2015-07-01

    This paper focuses on the improvement of a relaxor ferroelectric terpolymer, i.e., poly (vinylidene fluoride-trifluoroethylene-chlorofluoroethylene) [P(VDF-TrFE-CFE)], filled with a bis(2-ethylhexyl) phthalate (DEHP). The developed material gave rise to a significantly increased longitudinal electrostrictive strain, as well as an increased mechanical energy density under a relatively low electric field. These features were attributed to the considerably enhanced dielectric permittivity and a decreased Young modulus as a result of the introduction of only small DEHP plasticizer molecules. In addition, the plasticizer-filled terpolymer only exhibited a slight decrease of the dielectric breakdown strength, which was a great advantage with respect to the traditional polymer-based electrostrictive composites. More importantly, the approach proposed herein is promising for the future development and scale-up of new high-performance electrostrictive dielectrics under low applied electrical fields through modification simply by blending with a low-cost plasticizer. An experimental demonstration based on a flexible micro-fluidic application is described at the end of this paper, confirming the attractive characteristics of the proposed materials as well as the feasibility of integrating them as micro-actuators in small-scale devices.

  15. Open Tubular Microreactor with Enzyme Functionalized Micro- fluidic Channel for Amperometric Detection of Glucose

    Institute of Scientific and Technical Information of China (English)

    张蕾; 曲平; 盛金; 雷建平; 鞠烷先

    2012-01-01

    A simple and efficient method using enzyme immobilized microfluidic channel as open tubular microreactor was designed for amperometric detection of glucose. The microreactor was composed of a polydimethylsilicone/ glass hybrid device with three reservoirs, a cooling cave and a 6 cm capillary with a sampling fracture as micro-channel. The microchannel was further modified by thermal polymerization, followed by covalently attaching with glucose oxidase. Through fracture sampling and electrochromatography separation, the production via enzymatic reaction was determinated by Pt electrode at the end of capillary. The linear range for the detection of glucose was 0.05--7.5 mmol·L-1 with detection limit of 23μmol.L-1 The inter-and intra-chip reproducibilities for determination of 2.5 mmol-L-1 glucose were 98.5% (n=5) and 96.0% (n=5), respectively. With the advantage of flexible assembly, rapid efficiency, good stability and low-cost, this microreactor provided a potential platform for estab- lishing a portable enzyme-based chemical detection system in practical application.

  16. Transport coefficients for electrolytes in arbitrarily shaped nano and micro-fluidic channels

    CERN Document Server

    Mortensen, N A; Olesen, L H

    2006-01-01

    We consider laminar flow of incompressible electrolytes in long, straight channels driven by pressure and electro-osmosis. We use a Hilbert space eigenfunction expansion to address the general problem of an arbitrary cross section and obtain general results in linear-response theory for the hydraulic and electrical transport coefficients which satisfy Onsager relations. In the limit of non-overlapping Debye layers the transport coefficients are simply expressed in terms of parameters of the electrolyte as well as the geometrical correction factor for the Hagen-Poiseuille part of the problem. In particular, we consider the limits of thin non-overlapping as well as strongly overlapping Debye layers, respectively, and calculate the corrections to the hydraulic resistance due to electro-hydrodynamic interactions.

  17. 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.

  18. Automated micro fluidic system for PCR applications in the monitoring of drinking water quality; Aplicacion de sistemas bionaliticos integrados sobre plataformas de microfluidica en el control de la calidad microbiologica del agua

    Energy Technology Data Exchange (ETDEWEB)

    Soria Soria, E.; Yanez Amoros, A.; Murtula Corbi, R.; Catalan Cuenca, V.; Martin-Cisneros, C. S.; Ymbern, O.; Alonso-Chamorro, J.

    2009-07-01

    Microbiological laboratories present a growing interest in automated, simple and user-friendly methodologies able to perform simultaneous analysis of a high amount of samples. Analytical tools based on micro-fluidic could play an important role in this field. In this work, the development of an automated micro fluidic system for PCR applications and aimed to monitoring of drinking water quality is presented. The device will be able to determine, simultaneously, fecal pollution indicators and water-transmitted pathogens. Further-more, complemented with DNA pre-concentration and extraction modules, the device would present a highly integrated solution for microbiological diagnostic laboratories. (Author) 13 refs.

  19. Rapid, single-molecule assays in nano/micro-fluidic chips with arrays of closely spaced parallel channels fabricated by femtosecond laser machining.

    Science.gov (United States)

    Canfield, Brian K; King, Jason K; Robinson, William N; Hofmeister, William H; Davis, Lloyd M

    2014-08-20

    Cost-effective pharmaceutical drug discovery depends on increasing assay throughput while reducing reagent needs. To this end, we are developing an ultrasensitive, fluorescence-based platform that incorporates a nano/micro-fluidic chip with an array of closely spaced channels for parallelized optical readout of single-molecule assays. Here we describe the use of direct femtosecond laser machining to fabricate several hundred closely spaced channels on the surfaces of fused silica substrates. The channels are sealed by bonding to a microscope cover slip spin-coated with a thin film of poly(dimethylsiloxane). Single-molecule detection experiments are conducted using a custom-built, wide-field microscope. The array of channels is epi-illuminated by a line-generating red diode laser, resulting in a line focus just a few microns thick across a 500 micron field of view. A dilute aqueous solution of fluorescently labeled biomolecules is loaded into the device and fluorescence is detected with an electron-multiplying CCD camera, allowing acquisition rates up to 7 kHz for each microchannel. Matched digital filtering based on experimental parameters is used to perform an initial, rapid assessment of detected fluorescence. More detailed analysis is obtained through fluorescence correlation spectroscopy. Simulated fluorescence data is shown to agree well with experimental values.

  20. Rapid, Single-Molecule Assays in Nano/Micro-Fluidic Chips with Arrays of Closely Spaced Parallel Channels Fabricated by Femtosecond Laser Machining

    Directory of Open Access Journals (Sweden)

    Brian K. Canfield

    2014-08-01

    Full Text Available Cost-effective pharmaceutical drug discovery depends on increasing assay throughput while reducing reagent needs. To this end, we are developing an ultrasensitive, fluorescence-based platform that incorporates a nano/micro-fluidic chip with an array of closely spaced channels for parallelized optical readout of single-molecule assays. Here we describe the use of direct femtosecond laser machining to fabricate several hundred closely spaced channels on the surfaces of fused silica substrates. The channels are sealed by bonding to a microscope cover slip spin-coated with a thin film of poly(dimethylsiloxane. Single-molecule detection experiments are conducted using a custom-built, wide-field microscope. The array of channels is epi-illuminated by a line-generating red diode laser, resulting in a line focus just a few microns thick across a 500 micron field of view. A dilute aqueous solution of fluorescently labeled biomolecules is loaded into the device and fluorescence is detected with an electron-multiplying CCD camera, allowing acquisition rates up to 7 kHz for each microchannel. Matched digital filtering based on experimental parameters is used to perform an initial, rapid assessment of detected fluorescence. More detailed analysis is obtained through fluorescence correlation spectroscopy. Simulated fluorescence data is shown to agree well with experimental values.

  1. Rapid, single-molecule assays in nano/micro-fluidic chips with arrays of closely spaced parallel channels fabricated by femtosecond laser machining.

    Science.gov (United States)

    Canfield, Brian K; King, Jason K; Robinson, William N; Hofmeister, William H; Davis, Lloyd M

    2014-01-01

    Cost-effective pharmaceutical drug discovery depends on increasing assay throughput while reducing reagent needs. To this end, we are developing an ultrasensitive, fluorescence-based platform that incorporates a nano/micro-fluidic chip with an array of closely spaced channels for parallelized optical readout of single-molecule assays. Here we describe the use of direct femtosecond laser machining to fabricate several hundred closely spaced channels on the surfaces of fused silica substrates. The channels are sealed by bonding to a microscope cover slip spin-coated with a thin film of poly(dimethylsiloxane). Single-molecule detection experiments are conducted using a custom-built, wide-field microscope. The array of channels is epi-illuminated by a line-generating red diode laser, resulting in a line focus just a few microns thick across a 500 micron field of view. A dilute aqueous solution of fluorescently labeled biomolecules is loaded into the device and fluorescence is detected with an electron-multiplying CCD camera, allowing acquisition rates up to 7 kHz for each microchannel. Matched digital filtering based on experimental parameters is used to perform an initial, rapid assessment of detected fluorescence. More detailed analysis is obtained through fluorescence correlation spectroscopy. Simulated fluorescence data is shown to agree well with experimental values. PMID:25140634

  2. Micro-fluidic (Lab-on the- Chip) PCR Array Cartridge for Biological Screening in a Hand Held Device: FInal Report for CRADA no 264. PNNL-T2-258-RU with CombiMatrix Corp

    Energy Technology Data Exchange (ETDEWEB)

    Rainina, Evguenia I.

    2010-10-31

    The worldwide emergence of both new and old diseases resulting from human expansion and also human and materials mobility has and will continue to place stress on both medical and clinical diagnostics. The classical approach to bioagents detection involves the use of differential metabolic assays to determine species type in the case of most bacteria, or the use of cell culture and electron microscopy to diagnose viruses and some bacteria that are intracellular parasites. The long-term goal in bioagent detection is to develop a hand-held instrument featuring disposable cartridges which contain all the necessary reagents, reaction chambers, waste chambers, and micro-fluidics to extract, concentrate, amplify, and analyze nucleic acids. This GIPP project began development of a sensory platform using nucleic-acid based probes. Although research was not completed, initial findings indicated that an advanced sensing device could theoretically be built on a DNA/RNA-based technology platform.

  3. Micro-electroforming metallic bipolar electrodes for mini-DMFC stacks

    CERN Document Server

    Shyu, R F; Lee, J -H

    2008-01-01

    This paper describes the development of metallic bipolar plate fabrication using micro-electroforming process for mini-DMFC (direct methanol fuel cell) stacks. Ultraviolet (UV) lithography was used to define micro-fluidic channels using a photomask and exposure process. Micro-fluidic channels mold with 300 micrometers thick and 500 micrometers wide were firstly fabricated in a negative photoresist onto a stainless steel plate. Copper micro-electroforming was used to replicate the micro-fluidic channels mold. Following by sputtering silver (Ag) with 1.2 micrometers thick, the metallic bipolar plates were completed. The silver layer is used for corrosive resistance. The completed mini-DMFC stack is a 2x2 cm2 fuel cell stack including a 1.5x1.5 cm2 MEA (membrane electrode assembly). Several MEAs were assembly into mini-DMFC stacks using the completed metallic bipolar plates. All test results showed the metallic bipolar plates suitable for mini-DMFC stacks. The maximum output power density is 9.3mW/cm2 and curren...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-01-01

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

  5. Addressing the challenges of using ferromagnetic electrodes in the magnetic tunnel junction-based molecular spintronics devices

    Energy Technology Data Exchange (ETDEWEB)

    Tyagi, Pawan, E-mail: ptyagi@udc.edu; Friebe, Edward; Baker, Collin [University of the District of Columbia, Department of Mechanical Engineering (United States)

    2015-11-15

    Addressing the challenges of using high-Curie temperature ferromagnetic (FM) electrodes is critical for molecular spintronics devices (MSDs) research. Two FM electrodes simultaneously chemically bonded with a thiol-functionalized molecule can produce novel MSDs to exploring new quantum mechanical phenomenon and computer technologies. For developing a commercially viable MSD, it is crucial to developing a device fabrication scheme that carefully considers FM electrodes’ susceptibility to oxidation, chemical etching, and stress-induced deformations during fabrication and usage. This paper studies NiFe, an alloy extensively used in present-day memory devices and high-temperature engineering applications, as a candidate FM electrode for the fabrication of MSDs. Our spectroscopic reflectance studies show that NiFe oxidized aggressively after heating beyond ∼90 °C. The NiFe surfaces, aged for several months or heated for several minutes below ∼90 °C, exhibited remarkable electrochemical activity and were found suitable for chemical bonding with the thiol-functionalized molecular device elements. NiFe also demonstrated excellent etching resistance against commonly used solvents and lithography related chemicals. Additionally, NiFe mitigated the adverse effects of mechanical stress by subsiding the stress-induced deformities. A magnetic tunnel junction-based MSD approach was designed by carefully considering the merits and limitations of NiFe. The device fabrication protocol considers the safe temperature limit to avoiding irreversible surface oxidation, the effect of mechanical stresses, surface roughness, and chemical etching. This paper provides foundational experimental insights in realizing a versatile MSD allowing a wide range of transport and magnetic studies.

  6. Addressing the challenges of using ferromagnetic electrodes in the magnetic tunnel junction-based molecular spintronics devices

    International Nuclear Information System (INIS)

    Addressing the challenges of using high-Curie temperature ferromagnetic (FM) electrodes is critical for molecular spintronics devices (MSDs) research. Two FM electrodes simultaneously chemically bonded with a thiol-functionalized molecule can produce novel MSDs to exploring new quantum mechanical phenomenon and computer technologies. For developing a commercially viable MSD, it is crucial to developing a device fabrication scheme that carefully considers FM electrodes’ susceptibility to oxidation, chemical etching, and stress-induced deformations during fabrication and usage. This paper studies NiFe, an alloy extensively used in present-day memory devices and high-temperature engineering applications, as a candidate FM electrode for the fabrication of MSDs. Our spectroscopic reflectance studies show that NiFe oxidized aggressively after heating beyond ∼90 °C. The NiFe surfaces, aged for several months or heated for several minutes below ∼90 °C, exhibited remarkable electrochemical activity and were found suitable for chemical bonding with the thiol-functionalized molecular device elements. NiFe also demonstrated excellent etching resistance against commonly used solvents and lithography related chemicals. Additionally, NiFe mitigated the adverse effects of mechanical stress by subsiding the stress-induced deformities. A magnetic tunnel junction-based MSD approach was designed by carefully considering the merits and limitations of NiFe. The device fabrication protocol considers the safe temperature limit to avoiding irreversible surface oxidation, the effect of mechanical stresses, surface roughness, and chemical etching. This paper provides foundational experimental insights in realizing a versatile MSD allowing a wide range of transport and magnetic studies

  7. Light addressable gold electrodes

    OpenAIRE

    Khalid, Waqas

    2011-01-01

    The main objective carried out in this dissertation was to fabricate Light Amplified Potentiometric sensors (LAPS) based upon the semiconductor nanoparticles (quantum dots) instead of its bulk form. Quantum dots (QDs) were opted for this device fabrication because of their superior fluorescent, electric and catalytic properties. Also in comparison to their bulk counterparts they will make device small, light weighted and power ...

  8. Application of Micro-fluidics in Gas-liquid Separation of Subsea Gas and Oil Exploitation%微流体技术在深水油气开发气液分离中的应用

    Institute of Scientific and Technical Information of China (English)

    杨晓宇

    2013-01-01

    Carbon dioxide concentration is one of the properties to be determined by using sensing systems for assessing quality of natural gas during subsea exploitation.However,natural gas has other contents including water and oil,that is to say,motivated by the need for quantitative measurements of carbon dioxide concentration in multiphase mixture,so the tra-ditional measurement way can not ensure the instantaneity of measuring results.A special micro-fluidic channel was devel-oped which took advantage of surface tension effects.This system allows the separation of gas and liquid phases so that gas can be optically analyzed,carbon dioxide after separation can be measured through optical sensors.%在深水油气田开发过程中,CO2含量是估测天然气质量的重要参数,需用传感器对其进行测量;然而,天然气还包含有水和油等其他的成分,即需要在多相混合的情况下确定 CO2的浓度。而传统的测量方法无法保证测量结果的实时性;因此,设计了特殊的微流体通道系统,可使其利用微流体管道的表面张力效应对气相和液相进行分离。CO2对红外光的吸收可被用于在线测量,可采用光学传感器对分离后的 CO2浓度进行检测。

  9. Research Progress in Capillary Electrophoresis and Micro-fluidic Chip Electrophoresis Applied in Testing Genetically Modified Food%毛细管电泳与芯片电泳技术在转基因食品检测中的研究进展

    Institute of Scientific and Technical Information of China (English)

    李永新; 黎源倩; 何玲; 李灿

    2012-01-01

    大量的转基因生物体作为食品进入人们的生活,灵敏、快速、特异的检测方法对保护消费者的知情权和选择权、保障转基因标签制度的顺利实施起到了举足轻重的作用.毛细管电泳和芯片电泳作为新兴的分离技术,以其高通量、高灵敏度、快捷低耗的优势弥补了传统凝胶电泳的不足.对目前常用的转基因食品检测方法进行归纳和评价,并重点综述了近年来毛细管电泳与芯片电泳技术在转基因食品检测中的研究进展.%In the past few years,genetically modified organs as food ( GMC) have entered into people's daily life. The fast,sensitive and reliable testing methods have played a decisive role in protecting the customers' right to know and to choose,safeguarding the smooth implementation of labeling system for genetically modified food ( GMF) . Capillary electrophoresis and micro-fluidic chip electrophoresis,as relatively new technology has made up the deficiencies of traditional gel eleetrophoTesis with their high flux,high sensitivity,fast and low consumption. This paper summarized and assessed the common methods for testing GMF and laid emphasis in reviewing the research progress made in capillary and micro-fluidic chip electrophoresis for testing GMF in recent years.

  10. Topology optimization of flexible micro-fluidic devices

    DEFF Research Database (Denmark)

    Kreissl, Sebastian; Pingen, Georg; Evgrafov, Anton;

    2010-01-01

    A multi-objective topology optimization formulation for the design of dynamically tunable fluidic devices is presented. The flow is manipulated via external and internal mechanical actuation, leading to elastic deformations of flow channels. The design objectives characterize the performance...... in the undeformed and deformed configurations. The layout of fluid channels is determined by material topology optimization. In addition, the thickness distribution, the distribution of active material for internal actuation, and the support conditions are optimized. The coupled fluid-structure response...... is predicted by a non-linear finite element model and a hydrodynamic lattice Boltzmann method. Focusing on applications with low flow velocities and pressures, structural deformations due to fluid-forces are neglected. A mapping scheme is presented that couples the material distributions in the structural...

  11. Integrated LTCC micro-fluidic modules - an SMT flow sensor

    OpenAIRE

    Fournier, Yannick; Willigens, Raphael; Maeder, Thomas; Ryser, Peter

    2005-01-01

    This paper presents a thermal flow sensor based on the calorimetric principle realized by using low temperature co-fired ceramic (LTCC) technology, where the tapes and flow channel have been structured by laser machining. A standard configuration of a calorimetric sensor consists of a heater placed above the flow channel and temperature sensitive elements arranged symmetrically downstream and upstream. The temperature difference between temperature sensitive elements (at the upstream and down...

  12. Numerical Modeling of Micro Fluidics of Polymer Melts

    DEFF Research Database (Denmark)

    Marin, José Manuel Román; Rasmussen, Henrik K.

    2008-01-01

    film on a hard substrate. The numerical method is based on a Lagrangian kinematics description of the fluid, where the (Cartesian) coordinate system attached to the particles is discretized by ten-node quadratic tetrahedral elements. The time integral in the K-BKZ model is discretized by a quadratic......A new Galerkin finite element scheme for the numerical simulation of three-dimensional time-dependent flow of K-BKZ fluids has been developed. The scheme was used to model the polymer melt flow in nano imprint lithography (NIL). In NIL a sub micrometer pattern is hot pressed onto a thin polymer...

  13. Numerical Modeling of Flow Distribution in Micro-Fluidics Systems

    Science.gov (United States)

    Majumdar, Alok; Cole, Helen; Chen, C. P.

    2005-01-01

    This paper describes an application of a general purpose computer program, GFSSP (Generalized Fluid System Simulation Program) for calculating flow distribution in a network of micro-channels. GFSSP employs a finite volume formulation of mass and momentum conservation equations in a network consisting of nodes and branches. Mass conservation equation is solved for pressures at the nodes while the momentum conservation equation is solved at the branches to calculate flowrate. The system of equations describing the fluid network is solved by a numerical method that is a combination of the Newton-Raphson and successive substitution methods. The numerical results have been compared with test data and detailed CFD (computational Fluid Dynamics) calculations. The agreement between test data and predictions is satisfactory. The discrepancies between the predictions and test data can be attributed to the frictional correlation which does not include the effect of surface tension or electro-kinetic effect.

  14. Micro-electroforming metallic bipolar electrodes for mini-DMFC stacks

    OpenAIRE

    Shyu, R.F.; Yang, H; Lee, J.-H.

    2008-01-01

    Submitted on behalf of EDA Publishing Association (http://irevues.inist.fr/handle/2042/16838) International audience This paper describes the development of metallic bipolar plate fabrication using micro-electroforming process for mini-DMFC (direct methanol fuel cell) stacks. Ultraviolet (UV) lithography was used to define micro-fluidic channels using a photomask and exposure process. Micro-fluidic channels mold with 300 μm thick and 500 μm wide were firstly fabricated in a negative pho...

  15. IP Addressing

    OpenAIRE

    2006-01-01

    tut quiz anim This interactive tutorial covers the following: The concept of halving a binary number space., Using the halving concept to explain how the Internet IP space is segmented into the A, B, and C address classifications., How the first octet ranges for the A, B, and C IP space are produced.In this tutorial, explanations are illustrated by simple animations. Students are asked to observe number patterns, and check their observations against automated 'answers.' There is a qu...

  16. Inaugural Address

    OpenAIRE

    Syed Yousaf Raza Gilani

    2008-01-01

    Sardar Aseff Ahmad Ali, Deputy Chairman, Planning Commission, Dr Rashid Amjad, President, Pakistan Society of Development Economists, Honourable Ministers, Excellencies, Ladies and Gentlemen! It is indeed a privilege and honour to address this distinguished gathering of economists. I am very happy that this meeting is being attended by internationally acclaimed economists and academics from both within and outside the country. I am especially heartened to see that students of economics from a...

  17. Welcome Address

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@  On behalf of the International Life Sciences Institute, I welcome you to Beijing and to the Third Asian Conference on Food Safety and Nutrition. Many of you will remember the first Asian conference on Food Safety held in Kuala Lumpur in 1990 and the second held in Bangkok in 1994. These meetings have been so successful that ILSI made the commitment to host such a conference periodically in order to provide a forum to share the latest information and to set new goals and priorities.   This year, we have broadened the scope of the agenda to include issues on nutrition. I want to thank all of our co-sponsors and members of the Planning Committee for preparing such a comprehensive and timely program. Some of the issues and challenges facing Asia that will be addressed at this meeting are:

  18. Keynote address

    International Nuclear Information System (INIS)

    DOE biomass R ampersand D programs have the potential to provide America with both plentiful, clean-burning domestic transportation fuels and cost-competitive industrial and utility fuels, benefiting energy security in the United States. Biofuels developed under our programs will also help improve air quality, reduce greenhouse gases, reduce the large daily quantities of waste we produce, and revitalize rural America. These research motivations have been documented in the National Energy Strategy. DOE looks forward to expanding its biofuels research program and to forging a partnership with private sector for cost-shared commercialization of new fuels and vehicle technologies. Many alternative fuels (e.g., ethanol, methanol, compressed natural gas, propane, or electricity) are candidates for gaining market share. Indeed, there may be significant regional variation in the future fuel mix. Alcohol fuels from biomass, particularly ethanol, have the potential to make a major contribution. Currently, ethanol in the United States is almost entirely made from corn; and the limitations of that process are well known (e.g., costly feedstock, end product requiring subsidy to be competitive, use of fossil fuels in renewable feedstock production and processing, and potential adverse impact of corn ethanol production on the price of food). To address these concerns, the DOE biofuels program is pursuing an ambitious research program to develop the technologies needed to convert these crops into alternative transportation fuels, primarily cellulose-based ethanol and methanol. Program R ampersand D has reduced the estimated cost per gallon of cellulose-based ethanol from $3.60 in 1980 to the current $1.35, with a program goal of $0.60 by the year 2000. DOE is also investigating the thermochemical conversion of biomass to methanol. The program goal is to achieve commercial production of methanol (like ethanol) at the gasoline equivalent of $0.90 per gallon by the year 2000. 4 figs

  19. Presidential address.

    Science.gov (United States)

    Vohra, U

    1993-07-01

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

  20. Opening address

    International Nuclear Information System (INIS)

    The opening address by the host country started by thanking to the International Atomic Energy Agency for holding this important scientific event in in Morocco. The themes to be considered by this conference are among the priorities of the Scientific Research Department in its endeavour to promote scientific research in the field of nuclear science and technology for peaceful uses in Morocco. By so doing, this Department is following and supporting the efforts being made by our country to provide training, and elaborate rules and regulations, and to create infrastructure, acquire material and, equipment and encourage qualified and active researchers. Hence, the convening of this conference responds to a strategic interest of our country, which, similar to other countries, is committed to the achievement of comprehensive and sustainable development for the protection of human kind and the environment. This is considered nowadays as a strategic and vital objective as it entails the protection of people from radiation and against all kinds of professional risks and health hazards. Morocco attaches great importance to radiation safety issues. Our country adhered to all international conventions related to nuclear safety. It is in the process of adapting its internal regulations to international norms and standards, and it is making progress towards the establishment of a national safety body which meets those norms and standards, with the assistance of the IAEA. For this purpose, a standing committee for the follow-up of nuclear affairs has been created on the basis of Royal Instructions, and placed under the authority of the Prime Minister. Its task is to serve as a think-tank on nuclear safety issues and to make proposals on ways and means of reinforcing radiation safety measures. It goes without saying that the peaceful uses of nuclear energy must meet the safety standards elaborated by the IAEA. However, we are convinced that the elaboration of safety standards

  1. Opening address

    International Nuclear Information System (INIS)

    and become more technical. Involving experts from all fields is then crucial for success. This perception is reflected in the goals of this meeting. It is designed as an extensive information exchange forum between decision makers, regulators, radiation and waste safety specialists, and the nuclear industry. It is this mix which promises high efficiency with respect to solving the problems that you are addressing. I am sure that the safe termination of practices involving radioactive materials during the decommissioning of nuclear installations is one of the major challenges that industrialized nations will have to face during the next decades

  2. Welcome Address

    Science.gov (United States)

    Kiku, H.

    2014-12-01

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

  3. Opening address

    International Nuclear Information System (INIS)

    Nuclear terrorism has been recognized as a potential threat to human security and economic prosperity since at least the 1970s. Evidence of Al Qaeda's interest in acquiring nuclear material came to light during the 1990s. However, it is since the attacks of 11 September 2001 that the risk of nuclear terrorist acts has come to be a widespread public and governmental concern, for understandable reasons, and that efforts to combat illicit trafficking, which could lead to nuclear or other radioactive materials falling into the hands of terrorists, have intensified. Six years on, it makes sense to take stock of what has been achieved in the combat to stem illicit trafficking and of where further actions - actions of individual States and cooperative international actions - might usefully be initiated. The IAEA has maintained an Illicit Trafficking Database since 1995. Information reported to this database confirms that concerns about illicit trafficking in nuclear material are justified. Database information points to persistent theft and loss of radioactive sources. States' international obligations relevant to international nuclear trafficking are based on the Convention on the Physical Protection of Nuclear Material (CPPNM), the International Convention for the Suppression of Acts of Nuclear Terrorism, the United Nations Security Council Resolution 1540, which deals with weapons of mass destruction, including nuclear weapons and non-State actors, and the United Nations Security Council Resolution 1375, which requires all States to take the necessary steps to prevent the commission of terrorist acts, including early warning to other States. In addition to these legally binding instruments, there is the non-binding Code of Conduct on the Safety and Security of Radioactive Sources, which Member States of the IAEA agreed in 2003. The Code addresses the establishment of an adequate system of regulatory control, from the production of radioactive sources to their final

  4. Electrode array for neural stimulation

    Energy Technology Data Exchange (ETDEWEB)

    Wessendorf, Kurt O. (Albuquerque, NM); Okandan, Murat (Edgewood, NM); Stein, David J. (Albuquerque, NM); Yang, Pin (Albuquerque, NM); Cesarano, III, Joseph (Albuquerque, NM); Dellinger, Jennifer (Albuquerque, NM)

    2011-08-16

    An electrode array for neural stimulation is disclosed which has particular applications for use in a retinal prosthesis. The electrode array can be formed as a hermetically-sealed two-part ceramic package which includes an electronic circuit such as a demultiplexer circuit encapsulated therein. A relatively large number (up to 1000 or more) of individually-addressable electrodes are provided on a curved surface of a ceramic base portion the electrode array, while a much smaller number of electrical connections are provided on a ceramic lid of the electrode array. The base and lid can be attached using a metal-to-metal seal formed by laser brazing. Electrical connections to the electrode array can be provided by a flexible ribbon cable which can also be used to secure the electrode array in place.

  5. Magnetohydrodynamic electrode

    Science.gov (United States)

    Boquist, Carl W.; Marchant, David D.

    1978-01-01

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

  6. Opening address

    International Nuclear Information System (INIS)

    Being fully aware of the IAEA's central and important roles in the field of nuclear security, Japan has cooperated closely with the IAEA in the field of nuclear security. One of Japan's efforts was holding a seminar on strengthening nuclear security in Asian countries in November 2006, making use of Japan's contribution to the IAEA Nuclear Security Fund. The seminar was organized for the first time in Asia to address nuclear security matters, in which more than 100 experts from 19 countries participated. Japan also hosted a seminar, aimed at promoting the accession to the international counterterrorism conventions and protocols, inviting government officials and experts from Asia Pacific countries. At the seminar, Japan presented its experience and lessons learned with regard to its ratification of relevant international conventions such as the International Convention for the Suppression of Acts of Nuclear Terrorism and the Convention on the Physical Protection of Nuclear Material. Japan has also provided assistance for capacity building in the field of physical protection measures, and is preparing three projects for Asian countries through the IAEA Nuclear Security Fund. In Thailand, Japan has a project aimed at improving physical protection of nuclear research facilities. In Vietnam, Japan plans to host a workshop on radiation detection equipment for border officials and is also preparing for a seminar aimed at capacity building of control on nuclear material in Vietnam. Japan is committed to continue its efforts to make the IAEA Comprehensive Safeguards Agreement together with an Additional Protocol the universally accepted verification standard for the peaceful use undertakings of the Nuclear Non-Proliferation Treaty. Japan's basic policy on bilateral nuclear cooperation agreements is as follows. Considering the dual nature of nuclear material and technology, Japan is of the view that three Ss, that is, S for 'safeguards' (non-proliferation), S for 'safety

  7. Working Electrodes

    Science.gov (United States)

    Komorsky-Lovrić, Šebojka

    In electrochemistry an electrode is an electronic conductor in contact with an ionic conductor. The electronic conductor can be a metal, or a semiconductor, or a mixed electronic and ionic conductor. The ionic conductor is usually an electrolyte solution; however, solid electrolytes and ionic melts can be used as well. The term "electrode" is also used in a technical sense, meaning the electronic conductor only. If not specified otherwise, this meaning of the term "electrode" is the subject of the present chapter. In the simplest case the electrode is a metallic conductor immersed in an electrolyte solution. At the surface of the electrode, dissolved electroactive ions change their charges by exchanging one or more electrons with the conductor. In this electrochemical reaction both the reduced and oxidized ions remain in solution, while the conductor is chemically inert and serves only as a source and sink of electrons. The technical term "electrode" usually also includes all mechanical parts supporting the conductor (e.g., a rotating disk electrode or a static mercury drop electrode). Furthermore, it includes all chemical and physical modifications of the conductor, or its surface (e.g., a mercury film electrode, an enzyme electrode, and a carbon paste electrode). However, this term does not cover the electrolyte solution and the ionic part of a double layer at the electrode/solution interface. Ion-selective electrodes, which are used in potentiometry, will not be considered in this chapter. Theoretical and practical aspects of electrodes are covered in various books and reviews [1-9].

  8. Techniques of Electrode Fabrication

    Science.gov (United States)

    Guo, Liang; Li, Xinyong; Chen, Guohua

    Electrochemical applications using many kinds of electrode materials as an advanced oxidation/reduction technique have been a focus of research by a number of groups during the last two decades. The electrochemical approach has been adopted successfully to develop various environmental applications, mainly including water and wastewater treatment, aqueous system monitoring, and solid surface analysis. In this chapter, a number of methods for the fabrication of film-structured electrode materials were selectively reviewed. Firstly, the thermal decomposition method is briefly described, followed by introducing chemical vapor deposition (CVD) strategy. Especially, much attention was focused on introducing the methods to produce diamond novel film electrode owing to its unique physical and chemical properties. The principle and influence factors of hot filament CVD and plasma enhanced CVD preparation were interpreted by refereeing recent reports. Finally, recent developments that address electro-oxidation/reduction issues and novel electrodes such as nano-electrode and boron-doped diamond electrode (BDD) are presented in the overview.

  9. 微流控毛细管电泳-流动注射联用技术在分离和测定中药制剂中麻黄碱与伪麻黄碱的应用%Micro-fluidic capillary electrophoresis system with flow injection sample introduction applied to separation and determination of ephedrine and pseudoephedrine

    Institute of Scientific and Technical Information of China (English)

    陈宏丽; 张玉霞; 程玉桥; 陈兴国; 胡之德

    2007-01-01

    In this work, a microfluidic capillary electrophoresis system coupled to a flow injection sample introduction system using short capillary column as separation channel is described. This device contains an H-shaped microchip fixed on a planar plastic base, which utilizes a horizontal separation capillary with tubular side arms on each end that serve as inlet and outlet flow-through electrode reservoirs. Continuous FI introduction of a series of samples containing a standard mixture of ephedrine and pseudoephedrine allows a throughput rate up to 60 h-1 with complete baseline separation and high precision. The limits of detection (S/N=3) are 1.77 μg/mL for ephedrine and 2.03 μg/mL for pseudoephedrine, respectively. The microfluidic system has been applied to analyzing, for the first time, three commercial pharmaceutical preparations containing ephedrine or pseudoephedrine, and the results are satisfactory.%采用较短的毛细管作为分离通道,建立了一种微流控毛细管电泳和流动注射联用的分离测定麻黄碱和伪麻黄碱的新体系.该体系由一个H-型微芯片接口、一个水平放置的毛细管(作为分离通道)、两个竖直放置的Tygon管(作为阳极和阴极的电解质流通储液槽)组成.在最佳实验条件下,麻黄碱和伪麻黄碱标准品的进样频率可达到60 h-1,且完全基线分离,重现性良好,检测限(S/N=3)分别为:麻黄1.77 μg/mL,伪麻黄2.03 μg/mL.该微流控体系已用于3种含有麻黄碱和伪麻黄碱的市售药品的测定,结果令人满意.

  10. Address Points - Volusia County Addresses (Point)

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — Situs Addresses for Volusia County. Maintained by Growth and Resource Management. Addresses are determined by the cities for their jurisdiction and by the County...

  11. Water jet rebounds on hydrophobic surfaces : a first step to jet micro-fluidics.

    OpenAIRE

    Celestini, Franck; Kofman, R.; Noblin, Xavier; Pellegrin, Mathieu

    2010-01-01

    International audience When a water jet impinges upon a solid surface it produces a so called hydraulic jump that everyone can observe in the sink of its kitchen. It is characterized by a thin liquid sheet bounded by a circular rise of the surface due to capillary and gravitational forces. In this phenomenon, the impact induces a geometrical transition, from the cylindrical one of the jet to the bi-dimensional one of the film. A true jet rebound on a solid surface, for which the cylindrica...

  12. The butterfly proboscis as a fiber-based, self-cleaning, micro-fluidic system

    Science.gov (United States)

    Kornev, Kostantin G.; Monaenkova, Daria; Adler, Peter H.; Beard, Charles E.; Lee, Wah-Keat

    2016-04-01

    The butterfly proboscis is a unique, naturally engineered device for acquiring liquid food, which also minimizes concerns for viscosity and stickiness of the fluids. With a few examples, we emphasize the importance of the scale-form functionality triangle of this feeding device and the coupling through capillarity.

  13. Micro Fluidic Channel Machining on Fused Silica Glass Using Powder Blasting

    Directory of Open Access Journals (Sweden)

    Dong-Sam Park

    2008-02-01

    Full Text Available In this study, micro fluid channels are machined on fused silica glass via powder blasting, a mechanical etching process, and the machining characteristics of the channels are experimentally evaluated. In the process, material removal is performed by the collision of micro abrasives injected by highly compressed air on to the target surface. This approach can be characterized as an integration of brittle mode machining based on micro crack propagation. Fused silica glass, a high purity synthetic amorphous silicon dioxide, is selected as a workpiece material. It has a very low thermal expansion coefficient and excellent optical qualities and exceptional transmittance over a wide spectral range, especially in the ultraviolet range. The powder blasting process parameters affecting the machined results are injection pressure, abrasive particle size and density, stand-off distance, number of nozzle scanning, and shape/size of the required patterns. In this study, the influence of the number of nozzle scanning, abrasive particle size, and pattern size on the formation of micro channels is investigated. Machined shapes and surface roughness are measured using a 3-dimensional vision profiler and the results are discussed.

  14. Challenges in high accuracy surface replication for micro optics and micro fluidics manufacture

    DEFF Research Database (Denmark)

    Tosello, Guido; Hansen, Hans Nørgaard; Calaon, Matteo;

    2014-01-01

    by replication technologies such as nickel electroplating. All replication steps are enabled by a high precision master and high reproduction fidelity to ensure that the functionalities associated with the design are transferred to the final component. Engineered surface micro structures can be either......Patterning the surface of polymer components with microstructured geometries is employed in optical and microfluidic applications. Mass fabrication of polymer micro structured products is enabled by replication technologies such as injection moulding. Micro structured tools are also produced...... distributed, e.g., to create an optical pattern, or discretised, e.g., as micro channels for fluids manipulation. Key aspects of two process chains based on replication technologies for both types of micro structures are investigated: lateral replication fidelity, dimensional control at micro scale, edge...

  15. Bio-Inspired Micro-Fluidic Angular-Rate Sensor for Vestibular Prostheses

    Directory of Open Access Journals (Sweden)

    Charalambos M. Andreou

    2014-07-01

    Full Text Available This paper presents an alternative approach for angular-rate sensing based on the way that the natural vestibular semicircular canals operate, whereby the inertial mass of a fluid is used to deform a sensing structure upon rotation. The presented gyro has been fabricated in a commercially available MEMS process, which allows for microfluidic channels to be implemented in etched glass layers, which sandwich a bulk-micromachined silicon substrate, containing the sensing structures. Measured results obtained from a proof-of-concept device indicate an angular rate sensitivity of less than 1 °/s, which is similar to that of the natural vestibular system. By avoiding the use of a continually-excited vibrating mass, as is practiced in today’s state-of-the-art gyroscopes, an ultra-low power consumption of 300 μW is obtained, thus making it suitable for implantation.

  16. Micro-fluidic partitioning between polymeric sheets for chemical amplification and processing

    Science.gov (United States)

    Anderson, Brian L.

    2015-05-26

    A system for fluid partitioning for chemical amplification or other chemical processing or separations of a sample, comprising a first dispenser of a first polymeric sheet, wherein the first polymeric sheet contains chambers; a second dispenser of a second polymeric sheet wherein the first dispenser and the second dispenser are positioned so that the first polymeric sheet and the second polymeric sheet become parallel; a dispenser of the fluid positioned to dispense the fluid between the first polymeric sheet and the second polymeric sheet; and a seal unit that seals the first polymeric sheet and the second polymeric sheet together thereby sealing the sample between the first polymeric sheet and the second polymeric sheet and partitioning the fluid for chemical amplification or other chemical processing or separations.

  17. Design and testing of micro fluidic chemical analysis chip integrated with micro valveless pump

    Institute of Scientific and Technical Information of China (English)

    FU; Xin; XIE; Haibo; YANG; Huayong; JIA; Zhijian; FANG; Qun

    2005-01-01

    A new structure and working principle of the chip integrated with micro valveless pump for capillary electrophoresis was proposed in this paper. The micro valveless pump with plane structure has advantages of simple structure, and the process technology is compatible with existing micro chips for capillary electrophoresis. Based upon the mathematical model, simulation study of micro pump was carried out to investigate the influence of structural parameters on flow characteristics, and the performance of the integrated micro pump was also tested with different control parameters. The simulation results agree with the experimental results. Three samples, which are amino acid, fluorescein and buffer solution, have been examined with this chip. The results of the primary experiments showed that the micro valveless pump was promising in the integration and automatization of miniature integrated fluidic systems.

  18. Allegheny County Address Points

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — This dataset contains address points which represent physical address locations assigned by the Allegheny County addressing authority. Data is updated by County...

  19. Reach Address Database (RAD)

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Reach Address Database (RAD) stores the reach address of each Water Program feature that has been linked to the underlying surface water features (streams,...

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

    NARCIS (Netherlands)

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

    2006-01-01

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

  1. Micromachined electrode array

    Energy Technology Data Exchange (ETDEWEB)

    Okandan, Murat (Edgewood, NM); Wessendorf, Kurt O. (Albuquerque, NM)

    2007-12-11

    An electrode array is disclosed which has applications for neural stimulation and sensing. The electrode array, in certain embodiments, can include a plurality of electrodes each of which is flexibly attached to a common substrate using a plurality of springs to allow the electrodes to move independently. In other embodiments of the electrode array, the electrodes can be fixed to the substrate. The electrode array can be formed from a combination of bulk and surface micromachining, and can include electrode tips having an electroplated metal (e.g. platinum, iridium, gold or titanium) or a metal oxide (e.g. iridium oxide) for biocompatibility. The electrode array can be used to form a part of a neural prosthesis, and is particularly well adapted for use in an implantable retinal prosthesis.

  2. Flexible retinal electrode array

    Energy Technology Data Exchange (ETDEWEB)

    Okandan, Murat (Albuquerque, NM); Wessendorf, Kurt O. (Albuquerque, NM); Christenson, Todd R. (Albuquerque, NM)

    2006-10-24

    An electrode array which has applications for neural stimulation and sensing. The electrode array can include a large number of electrodes each of which is flexibly attached to a common substrate using a plurality of springs to allow the electrodes to move independently. The electrode array can be formed from a combination of bulk and surface micromachining, with electrode tips that can include an electroplated metal (e.g. platinum, iridium, gold or titanium) or a metal oxide (e.g. iridium oxide) for biocompatibility. The electrode array can be used to form a part of a neural prosthesis, and is particularly well adapted for use in an implantable retinal prosthesis where the electrodes can be tailored to provide a uniform gentle contact pressure with optional sensing of this contact pressure at one or more of the electrodes.

  3. Dry electrodes for electrocardiography

    International Nuclear Information System (INIS)

    Patient biopotentials are usually measured with conventional disposable Ag/AgCl electrodes. These electrodes provide excellent signal quality but are irritating for long-term use. Skin preparation is usually required prior to the application of electrodes such as shaving and cleansing with alcohol. To overcome these difficulties, researchers and caregivers seek alternative electrodes that would be acceptable in clinical and research environments. Dry electrodes that operate without gel, adhesive or even skin preparation have been studied for many decades. They are used in research applications, but they have yet to achieve acceptance for medical use. So far, a complete comparison and evaluation of dry electrodes is not well described in the literature. This work compares dry electrodes for biomedical use and physiological research, and reviews some novel systems developed for cardiac monitoring. Lastly, the paper provides suggestions to develop a dry-electrode-based system for mobile and long-term cardiac monitoring applications. (topical review)

  4. The Composite Insertion Electrode

    DEFF Research Database (Denmark)

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

    1984-01-01

    The specific energy obtainable by discharge of porous insertion electrodes is limited by electrolyte depletion in thepores. This can be overcome using a solid ion conductor as electrolyte. The term "composite" is used to distinguishthese electrodes from porous electrodes with liquid electrolyte. ...... conductivities, the thicknessof the electrode, the volume fractions, and the slope of the potential curve.......The specific energy obtainable by discharge of porous insertion electrodes is limited by electrolyte depletion in thepores. This can be overcome using a solid ion conductor as electrolyte. The term "composite" is used to distinguishthese electrodes from porous electrodes with liquid electrolyte....... The theoretical basis for such electrodes is discussedand, using a simplified model, equations are derived to describe the distribution of potential and current duringdischarge/charge operation. Under the assumption that the insertion compound particles are small enough to ensureequilibrium, and that the local...

  5. Addressing Sexual Harassment

    Science.gov (United States)

    Young, Ellie L.; Ashbaker, Betty Y.

    2008-01-01

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

  6. Addressing Social Issues.

    Science.gov (United States)

    Schoebel, Susan

    1991-01-01

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

  7. Insulated ECG electrodes

    Science.gov (United States)

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

    1973-01-01

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

  8. Microresonator electrode design

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-05-10

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

  9. A Simple Hydrogen Electrode

    Science.gov (United States)

    Eggen, Per-Odd

    2009-01-01

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

  10. Bioreactors Addressing Diabetes Mellitus

    OpenAIRE

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

    2014-01-01

    The concept of bioreactors in biochemical engineering is a well-established process; however, the idea of applying bioreactor technology to biomedical and tissue engineering issues is relatively novel and has been rapidly accepted as a culture model. Tissue engineers have developed and adapted various types of bioreactors in which to culture many different cell types and therapies addressing several diseases, including diabetes mellitus types 1 and 2. With a rising world of bioreactor develop...

  11. Electrical impedance tomography system based on active electrodes

    International Nuclear Information System (INIS)

    Electrical impedance tomography (EIT) can image the distribution of ventilated lung tissue, and is thus a promising technology to help monitor patient breathing to help selection of mechanical ventilation parameters. Two key difficulties in EIT instrumentation make such monitoring difficult: (1) EIT data quality depends on good electrode contact and is sensitive to changes in contact quality, and (2) EIT electrodes are difficult and time consuming to place on patients. This paper presents the design and initial tests of an active electrode-based system to address these difficulties. Our active electrode EIT system incorporates an active electrode belt, a central voltage-driven current source, central analog to digital converters and digital to analog converters, a central FPGA-based demodulator and controller. The electrode belt is designed incorporating 32 active electrodes, each of which contains the electronic amplifiers, switches and associated logic. Tests show stable device performance with a convenient ease of use and good imaging ability in volunteer tests. (paper)

  12. 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.

  13. Operation of a planar-electrode ion trap array with adjustable RF electrodes

    CERN Document Server

    Kumph, Muir; Langer, Kirsten; Niedermayr, Michael; Brownnutt, Michael; Blatt, Rainer

    2014-01-01

    One path to scaling-up trapped atomic ions for large-scale quantum computing and simulation is to create a two-dimensional array of ion traps in close proximity to each other. A method to control the interactions between nearest neighboring ions is demonstrated and characterized here, using an adjustable radio-frequency (RF) electrode between trapping sites. A printed circuit board planar-electrode ion trap is demonstrated, trapping laser-cooled $^{40}$Ca$^+$ ions. RF shuttling and secular-frequency adjustment are shown as a function of the power applied to the addressed RF electrode. The trapped ion's heating rate is measured via a fluorescence recooling method.

  14. Bioreactors addressing diabetes mellitus.

    Science.gov (United States)

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

    2014-11-01

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

  15. Addressing Environmental Health Inequalities

    Science.gov (United States)

    Gouveia, Nelson

    2016-01-01

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

  16. Addressing Environmental Health Inequalities.

    Science.gov (United States)

    Gouveia, Nelson

    2016-01-01

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

  17. Integrated optical addressing of an ion qubit

    CERN Document Server

    Mehta, Karan K; McConnell, Robert; Ram, Rajeev J; Sage, Jeremy M; Chiaverini, John

    2015-01-01

    Scalable implementation of the optics required to control trapped atomic ions' quantum states will be required to construct large-scale ion trap quantum information processors. All experiments in ion traps so far have employed approaches cumbersome to scale to even a few tens of qubits, with the majority relying on manipulation of free space beams with bulk optics. Here we demonstrate lithographically defined nanophotonic dielectric waveguides integrated within a linear surface-electrode ion trap chip, and qubit addressing at multiple locations via focusing grating couplers that emit through openings in the trap electrodes to an ion trapped 50 $\\mu$m above the chip. We perform quantum coherent operations using visible light routed in and emitted from silicon nitride waveguides and couplers, on the optical qubit transition in individual $^{88}$Sr$^+$ ions. The addressing beam is focused near the ion position with a 2 $\\mu$m 1/$e^2$-radius along the trap axis, and we measure crosstalk errors between $10^{-2}$ a...

  18. Bifunctional alkaline oxygen electrodes

    Science.gov (United States)

    Swette, L.; Kackley, N.; Mccatty, S. A.

    1991-01-01

    The authors describe the identification and testing of electrocatalysts and supports for the positive electrode of moderate-temperature, single-unit, rechargeable alkaline fuel cells. Recent work on Na(x)Pt3O4, a potential bifunctional catalyst, is described, as well as the application of novel approaches to the development of more efficient bifunctional electrode structures. The three dual-character electrodes considered here showed similar superior performance; the Pt/RhO2 and Rh/RhO2 electrodes showed slightly better performance than the Pt/IrO2 electrode. It is concluded that Na(x)Pt3O4 continues to be a promising bifunctional oxygen electrode catalyst but requires further investigation and development.

  19. Carbon-based electrode materials for DNA electroanalysis.

    Science.gov (United States)

    Kato, Dai; Niwa, Osamu

    2013-01-01

    This review addresses recent studies of newly developed carbon-based electrode materials and their use for DNA electroanalysis. Recently, new carbon materials including carbon nanotubes (CNT), graphene and diamond-based nanocarbon electrodes have been actively developed as sensing platforms for biomolecules, such as DNA and proteins. Electrochemical techniques using these new material-based electrodes can provide very simple and inexpensive sensing platforms, and so are expected to be used as one of the "post-light" DNA analysis methods, which include coulometric detection, amperometric detection with electroactive tags or intercalators, and potentiometric detection. DNA electroanalysis using these new carbon materials is summarized in view of recent advances on electrodes.

  20. Pocket ECG electrode

    Science.gov (United States)

    Lund, Gordon F. (Inventor)

    1982-01-01

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

  1. Handbook of reference electrodes

    CERN Document Server

    Inzelt, György; Scholz, Fritz

    2013-01-01

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

  2. Addressing psychiatric comorbidity.

    Science.gov (United States)

    Woody, G E; McLellan, A T; O'Brien, C P; Luborsky, L

    1991-01-01

    Research studies indicate that addressing psychiatric comorbidity can improve treatment for selected groups of substance-abusing patients. However, the chances for implementing the necessary techniques on a large scale are compromised by the absence of professional input and guidance within programs. This is especially true in public programs, which treat some of the most disadvantaged, disturbed, and socially destructive individuals in the entire mental health system. One starting point for upgrading the level of knowledge and training of staff members who work in this large treatment system could be to develop a better and more authoritative information dissemination network. Such a system exists in medicine; physicians are expected to read appropriate journals and to guide their treatment decisions using the data contained in the journals. Standards of practice and methods for modifying current practice are within the tradition of reading new facts, studying old ones, and comparing treatment outcome under different conditions with what is actually being done. No such general system of information-gathering or -sharing exists, particularly in public treatment programs. One of the most flagrant examples of this "educational shortfall" can be found among those methadone programs that adamantly insist on prescribing no more than 30 to 35 mg/day for all patients, in spite of the overwhelming evidence that these dose levels generally are inadequate. In some cases, program directors are unaware of studies that have shown the relationship between dose and outcome. In other cases, they are aware of the studies but do not modify their practices accordingly. This example of inadequate dosing is offered as an example of one situation that could be improved by adherence to a system of authoritative and systematic information dissemination. Many issues in substance abuse treatment do not lend themselves to information dissemination as readily as that of methadone dosing

  3. Bifunctional catalytic electrode

    Science.gov (United States)

    Cisar, Alan (Inventor); Murphy, Oliver J. (Inventor); Clarke, Eric (Inventor)

    2005-01-01

    The present invention relates to an oxygen electrode for a unitized regenerative hydrogen-oxygen fuel cell and the unitized regenerative fuel cell having the oxygen electrode. The oxygen electrode contains components electrocatalytically active for the evolution of oxygen from water and the reduction of oxygen to water, and has a structure that supports the flow of both water and gases between the catalytically active surface and a flow field or electrode chamber for bulk flow of the fluids. The electrode has an electrocatalyst layer and a diffusion backing layer interspersed with hydrophilic and hydrophobic regions. The diffusion backing layer consists of a metal core having gas diffusion structures bonded to the metal core.

  4. A semiconductor based electrode

    Energy Technology Data Exchange (ETDEWEB)

    Khamatani, A.; Kobayasi, K.

    1983-03-30

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

  5. A model for μ-biomimetic thermal infrared sensors based on the infrared receptors of Melanophila acuminata.

    Science.gov (United States)

    Siebke, Georg; Holik, Peter; Schmitz, Sam; Schmitz, Helmut; Lacher, Manfred; Steltenkamp, Siegfried

    2014-09-01

    Beetles of the genus Melanophila acuminata detect forest fires from distances as far as 130 km with infrared-sensing organs. Inspired by this extremely sensitive biological device, we are developing an IR sensor that operates at ambient temperature using MEMS technology. The sensor consists of two liquid-filled chambers that are connected by a micro-fluidic system. Absorption of IR radiation by one of these chambers leads to heating and expansion of a liquid. The increasing pressure deflects a membrane covered by one electrode of a plate capacitor. The micro-fluidic system and the second chamber represent a fluidic low-pass filter, preventing slow, but large pressure changes. However, the strong frequency dependence of the filter demands a precise characterization of its properties. Here, we present a theoretical model that describes the frequency-dependent response of the sensor based on material properties and geometrical dimensions. Our model is divided into four distinct parts that address different aspects of the sensor. The model describes the frequency-dependent behaviour of the fluidic filter and a thermal low-pass filter as well as saturation effects at low frequencies. This model allows the calculation of optimal design parameters, and thereby provides the foundation for the development of such a sensor.

  6. A model for μ-biomimetic thermal infrared sensors based on the infrared receptors of Melanophila acuminata

    International Nuclear Information System (INIS)

    Beetles of the genus Melanophila acuminata detect forest fires from distances as far as 130 km with infrared-sensing organs. Inspired by this extremely sensitive biological device, we are developing an IR sensor that operates at ambient temperature using MEMS technology. The sensor consists of two liquid-filled chambers that are connected by a micro-fluidic system. Absorption of IR radiation by one of these chambers leads to heating and expansion of a liquid. The increasing pressure deflects a membrane covered by one electrode of a plate capacitor. The micro-fluidic system and the second chamber represent a fluidic low-pass filter, preventing slow, but large pressure changes. However, the strong frequency dependence of the filter demands a precise characterization of its properties. Here, we present a theoretical model that describes the frequency-dependent response of the sensor based on material properties and geometrical dimensions. Our model is divided into four distinct parts that address different aspects of the sensor. The model describes the frequency-dependent behaviour of the fluidic filter and a thermal low-pass filter as well as saturation effects at low frequencies. This model allows the calculation of optimal design parameters, and thereby provides the foundation for the development of such a sensor. (paper)

  7. Electrochemical Patterning and Detection of DNA Arrays on a Two-Electrode Platform

    OpenAIRE

    Furst, Ariel; Landefeld, Sally; Hill, Michael G.; Barton, Jacqueline K.

    2013-01-01

    We report a novel method of DNA array formation that is electrochemically formed and addressed with a two-electrode platform. Electrochemical activation of a copper catalyst, patterned with one electrode, enables precise placement of multiple sequences of DNA onto a second electrode surface. The two-electrode patterning and detection platform allows for both spatial resolution of the patterned DNA array and optimization of detection through DNA-mediated charge transport with electrocatalysis....

  8. Influence of process parameters on edge replication quality of lab-on-a-chip micro fluidic systems geometries

    DEFF Research Database (Denmark)

    Calaon, Matteo; Tosello, Guido; Hansen, Hans Nørgaard;

    2013-01-01

    the replication quality of molded micro-features on cyclic olefin copolymer (COC) a tool insert collecting critical channel cross sections was manufactured. The master was made by UV lithography and subsequent nickel electroplating. Effect of packing phase parameters (packing time, packing pressure) and mold...

  9. A new simple and fast thermally-solvent assisted method to bond PMMA–PMMA in micro-fluidics devices

    Science.gov (United States)

    Bamshad, Arshya; Nikfarjam, Alireza; Khaleghi, Hossein

    2016-06-01

    A rapid and simple thermally-solvent assisted method of bonding was introduced for poly(methyl methacrylate) (PMMA) based microfluidic substrates. The technique is a low-temperature (68 {}^\\circ \\text{C} ), and rapid (15 \\min ) bonding technique; in addition, only a fan-assisted oven with some paper clamps are used. Two different solvents (ethanol and isopropyl alcohol) with two different methods of cooling (one-step and three steps) were employed to determine the best solvent and method of cooling (residual stresses may be released in different cooling methods) by considering bonding strength and quality. In this bonding technique, a thin film of solvent between two PMMA sheets disperses tends to dissolve a thin film of PMMA sheet surface, then evaporate, and finally reconnect monomers of the PMMA sheets at the specific operating temperature. The operating temperature of this method comes from the coincidence of the solubility parameter graph of PMMA with the solubility parameter graph of the solvents. Different tests such as tensile strength test, deformation test, leakage tests, and surface characteristics tests were performed to find the optimum conditions for this bonding strategy. The best bonding quality and the highest bonding strength (28.47 \\text{MPa} ) occurred when 70% isopropyl alcohol solution was employed with the one-step cooling method. Furthermore, the bonding reversibility was taken into account and critical percentages for irreversible bonding were obtained for both of the solvents and methods. This method provides a perfect bonding quality for PMMA substrates, and can be used in laboratories without needing any expensive and special instruments, because of its merits such as lower bonding time, lower-cost, and higher strength etc in comparison with the majority of other common bonding techniques.

  10. Co-integration of optical and micro-fluidic approaches on glass for chemical analysis in harsh environment

    International Nuclear Information System (INIS)

    The current will of reducing environment and human hazards has led the scientists to imagine new solutions for nuclear waste reprocessing. Miniaturized online chemical analysis of industrial processes has in particular an important role to play to reduce effluent volumes, response times and costs. In this context, we present the design, fabrication and characterization of an integrated spectrophotometric sensor on glass for chemical analysis of radioactive cations. The device is called a - nano-channel waveguide - and is fabricated by reactive ion etching and ion exchange on glass. It is made of two borosilicate glass wafers bonded together. The first one contains a strip core and the second one a (100 ±10) nm deep nano-channel and a slab core. It allows the propagation of a hybrid mode, optimizing the fluid/guide wave interaction on a large wavelength range. Spectrometric measurements of a neodymium nitrate in nitric acid (pH 2) followed by statistical treatment have led to a limit of detection in terms of absorption coefficient of (3.7 ± 0.9) * 10-3 cm-1 for a device length of (3.70 ± 0.05) cm and fluid volume as low as (7 ± 3) nL. A structure allowing to increase the interaction length and therefore further decrease the detection limit has been proposed as an outlook of this work, and a preliminary study for use in a nuclear environment has been performed. (author)

  11. Address Points, Addressing, Published in 2008, Taylor County.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Address Points dataset, was produced all or in part from Orthoimagery information as of 2008. It is described as 'Addressing'. Data by this publisher are often...

  12. Observations of IPv6 Addresses

    OpenAIRE

    Malone, David

    2008-01-01

    IPv6 addresses are longer than IPv4 addresses, and are so capable of greater expression. Given an IPv6 address, conventions and standards allow us to draw conclusions about how IPv6 is being used on the node with that address. We show a technique for analysing IPv6 addresses and apply it to a number of datasets. The datasets include addresses seen at a busy mirror server, at an IPv6-enabled TLD DNS server and when running traceroute across the production IPv6 network. The technique quantif...

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

    Science.gov (United States)

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

    2011-04-01

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

  14. Sensor employing internal reference electrode

    DEFF Research Database (Denmark)

    2013-01-01

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

  15. Capacitive de-ionization electrode

    Energy Technology Data Exchange (ETDEWEB)

    Daily, III, William D.

    2013-03-19

    An electrode "cell" for use in a capacitive deionization (CDI) reactor consists of the electrode support structure, a non-reactive conductive material, the electrode accompaniment or substrate and a flow through screen/separator. These "layers" are repeated and the electrodes are sealed together with gaskets between two end plates to create stacked sets of alternating anode and cathode electrodes in the CDI reactor.

  16. Reference Electrodes in Metal Corrosion

    OpenAIRE

    S. Szabó; Bakos, I.

    2010-01-01

    With especial regard to hydrogen electrode, the theoretical fundamentals of electrode potential, the most important reference electrodes and the electrode potential measurement have been discussed. In the case of the hydrogen electrode, it have been emphasised that there is no equilibrium between the hydrogen molecule (H2) and the hydrogen (H+), hydronium (H3O+) ion in the absence of a suitable catalyst. Taking into account the practical aspects as well, the theorectical basis of working of h...

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

    Science.gov (United States)

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

    2014-01-01

    Traditional neuronal interfaces utilize metallic electrodes which in recent years have reached a plateau in terms of the ability to provide safe stimulation at high resolution or rather with high densities of microelectrodes with improved spatial selectivity. To achieve higher resolution it has become clear that reducing the size of electrodes is required to enable higher electrode counts from the implant device. The limitations of interfacing electrodes including low charge injection limits, mechanical mismatch and foreign body response can be addressed through the use of organic electrode coatings which typically provide a softer, more roughened surface to enable both improved charge transfer and lower mechanical mismatch with neural tissue. Coating electrodes with conductive polymers or carbon nanotubes offers a substantial increase in charge transfer area compared to conventional platinum electrodes. These organic conductors provide safe electrical stimulation of tissue while avoiding undesirable chemical reactions and cell damage. However, the mechanical properties of conductive polymers are not ideal, as they are quite brittle. Hydrogel polymers present a versatile coating option for electrodes as they can be chemically modified to provide a soft and conductive scaffold. However, the in vivo chronic inflammatory response of these conductive hydrogels remains unknown. A more recent approach proposes tissue engineering the electrode interface through the use of encapsulated neurons within hydrogel coatings. This approach may provide a method for activating tissue at the cellular scale, however, several technological challenges must be addressed to demonstrate feasibility of this innovative idea. The review focuses on the various organic coatings which have been investigated to improve neural interface electrodes. PMID:24904405

  18. Port virtual addressing for PC

    International Nuclear Information System (INIS)

    Instruments for nuclear signal measurements based on add-on card for a personal computer (PC) are designed often. Then one faces the problem of the addressing of data input/output devices which show an integration level or intelligence that makes the use of several port address indispensable, and these are limited in the PC. The virtual addressing offers the advantage of the occupation of few addresses to accede to many of these devices. The principles of this technique and the appliances of a solution in radiometric in a radiometric card based on programmed logic are discussed in this paper

  19. 2015 ASHG Awards and Addresses

    Science.gov (United States)

    2016-01-01

    Each year at the annual meeting of The American Society of Human Genetics (ASHG), addresses are given in honor of The Society and a number of award winners. A summary of each of these is given below. On the following pages, we have printed the presidential address and the addresses for the William Allan Award, the Curt Stern Award, and the Victor A. McKusick Leadership Award. Webcasts of these addresses, as well as those of many other presentations, can be found at http://www.ashg.org.

  20. Reclaiming unused IPv4 addresses

    CERN Multimedia

    IT Department

    2016-01-01

    As many people might know, the number of IPv4 addresses is limited and almost all have been allocated (see here and here for more information).   Although CERN has been allocated some 340,000 addresses, the way these are allocated across the site is not as efficient as we would like. As we face an increasing demand for IPv4 addresses with the growth in virtual machines, the IT Department’s Communication Systems Group will be reorganising address allocation during 2016 to make more efficient use of the IPv4 address ranges that have been allocated to CERN. We aim, wherever possible, to avoid giving out fixed IP addresses, and have all devices connected to the campus network obtain an address dynamically each time they connect. As a first stage, starting in February, IP addresses that have not been used for more than 9 months will be reclaimed. No information about the devices concerned will be deleted from LANDB, but a new IP address will have to be requested if they are ever reconnected to t...

  1. Ion-selective electrodes

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-06-01

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

  2. Single Electrode Heat Effects

    DEFF Research Database (Denmark)

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

    1977-01-01

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

  3. Ion-selective electrodes

    CERN Document Server

    Mikhelson, Konstantin N

    2013-01-01

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

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

    International Nuclear Information System (INIS)

    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. (paper)

  5. Dry EEG Electrodes

    Science.gov (United States)

    Lopez-Gordo, M. A.; Sanchez-Morillo, D.; Valle, F. Pelayo

    2014-01-01

    Electroencephalography (EEG) emerged in the second decade of the 20th century as a technique for recording the neurophysiological response. Since then, there has been little variation in the physical principles that sustain the signal acquisition probes, otherwise called electrodes. Currently, new advances in technology have brought new unexpected fields of applications apart from the clinical, for which new aspects such as usability and gel-free operation are first order priorities. Thanks to new advances in materials and integrated electronic systems technologies, a new generation of dry electrodes has been developed to fulfill the need. In this manuscript, we review current approaches to develop dry EEG electrodes for clinical and other applications, including information about measurement methods and evaluation reports. We conclude that, although a broad and non-homogeneous diversity of approaches has been evaluated without a consensus in procedures and methodology, their performances are not far from those obtained with wet electrodes, which are considered the gold standard, thus enabling the former to be a useful tool in a variety of novel applications. PMID:25046013

  6. Photoelectrosynthesis at semiconductor electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Nozik, A. J.

    1980-12-01

    The general principles of photoelectrochemistry and photoelectrosynthesis are reviewed and some new developments in photoelectrosynthesis are discussed. Topics include energetics of semiconductor-electrolyte interfaces(band-edge unpinning); hot carrier injection at illuminated semiconductor-electrolyte junctions; derivatized semiconductor electrodes; particulate photoelectrochemical systems; layered compounds and other new materials; and dye sensitization. (WHK)

  7. Ion-selective electrode reviews

    CERN Document Server

    Thomas, J D R

    1985-01-01

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

  8. Electroanalysis with carbon paste electrodes

    CERN Document Server

    Svancara, Ivan; Walcarius, Alain; Vytras, Karel

    2011-01-01

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

  9. Small, fast, and tough: Shrinking down integrated elastomer transducers

    Science.gov (United States)

    Rosset, Samuel; Shea, Herbert R.

    2016-09-01

    We review recent progress in miniaturized dielectric elastomer actuators (DEAs), sensors, and energy harvesters. We focus primarily on configurations where the large strain, high compliance, stretchability, and high level of integration offered by dielectric elastomer transducers provide significant advantages over other mm or μm-scale transduction technologies. We first present the most active application areas, including: tunable optics, soft robotics, haptics, micro fluidics, biomedical devices, and stretchable sensors. We then discuss the fabrication challenges related to miniaturization, such as thin membrane fabrication, precise patterning of compliant electrodes, and reliable batch fabrication of multilayer devices. We finally address the impact of miniaturization on strain, force, and driving voltage, as well as the important effect of boundary conditions on the performance of mm-scale DEAs.

  10. Electrode models in electrical impedance tomography

    Institute of Scientific and Technical Information of China (English)

    WANG M.

    2005-01-01

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

  11. Correction of electrode modelling errors in multi-frequency EIT imaging.

    Science.gov (United States)

    Jehl, Markus; Holder, David

    2016-06-01

    The differentiation of haemorrhagic from ischaemic stroke using electrical impedance tomography (EIT) requires measurements at multiple frequencies, since the general lack of healthy measurements on the same patient excludes time-difference imaging methods. It has previously been shown that the inaccurate modelling of electrodes constitutes one of the largest sources of image artefacts in non-linear multi-frequency EIT applications. To address this issue, we augmented the conductivity Jacobian matrix with a Jacobian matrix with respect to electrode movement. Using this new algorithm, simulated ischaemic and haemorrhagic strokes in a realistic head model were reconstructed for varying degrees of electrode position errors. The simultaneous recovery of conductivity spectra and electrode positions removed most artefacts caused by inaccurately modelled electrodes. Reconstructions were stable for electrode position errors of up to 1.5 mm standard deviation along both surface dimensions. We conclude that this method can be used for electrode model correction in multi-frequency EIT.

  12. Ion-selective electrode reviews

    CERN Document Server

    Thomas, J D R

    1983-01-01

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

  13. Magnetohydrodynamic generator electrode

    Science.gov (United States)

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

    1979-01-01

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

  14. Graphene-based electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Xiao; Zeng, Zhiyuan; Fan, Zhanxi; Liu, Juqing; Zhang, Hua [School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798 (Singapore)

    2012-11-27

    Graphene, the thinnest two dimensional carbon material, has become the subject of intensive investigation in various research fields because of its remarkable electronic, mechanical, optical and thermal properties. Graphene-based electrodes, fabricated from mechanically cleaved graphene, chemical vapor deposition (CVD) grown graphene, or massively produced graphene derivatives from bulk graphite, have been applied in a broad range of applications, such as in light emitting diodes, touch screens, field-effect transistors, solar cells, supercapacitors, batteries, and sensors. In this Review, after a short introduction to the properties and synthetic methods of graphene and its derivatives, we will discuss the importance of graphene-based electrodes, their fabrication techniques, and application areas. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  15. Graphene-based electrodes.

    Science.gov (United States)

    Huang, Xiao; Zeng, Zhiyuan; Fan, Zhanxi; Liu, Juqing; Zhang, Hua

    2012-11-27

    Graphene, the thinnest two dimensional carbon material, has become the subject of intensive investigation in various research fields because of its remarkable electronic, mechanical, optical and thermal properties. Graphene-based electrodes, fabricated from mechanically cleaved graphene, chemical vapor deposition (CVD) grown graphene, or massively produced graphene derivatives from bulk graphite, have been applied in a broad range of applications, such as in light emitting diodes, touch screens, field-effect transistors, solar cells, supercapacitors, batteries, and sensors. In this Review, after a short introduction to the properties and synthetic methods of graphene and its derivatives, we will discuss the importance of graphene-based electrodes, their fabrication techniques, and application areas. PMID:22927209

  16. Addressing problems of employee performance.

    Science.gov (United States)

    McConnell, Charles R

    2011-01-01

    Employee performance problems are essentially of 2 kinds: those that are motivational in origin and those resulting from skill deficiencies. Both kinds of problems are the province of the department manager. Performance problems differ from problems of conduct in that traditional disciplinary processes ordinarily do not apply. Rather, performance problems are addressed through educational and remedial processes. The manager has a basic responsibility in ensuring that everything reasonable is done to help each employee succeed. There are a number of steps the manager can take to address employee performance problems.

  17. Keynote Address: Rev. Mark Massa

    Science.gov (United States)

    Massa, Mark S.

    2011-01-01

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

  18. Introduction to IP address management

    CERN Document Server

    Rooney, Tim

    2010-01-01

    "The book begins with a basic overview of IP networking, followed by chapters describing each of the three core IPAM technologies: IPv4 and IPv6 addressing, DHCP, and DNS. The next three chapters describe IPAM management techniques and practice, followed by chapters on IPv4-IPv6 co-existence, security and the IPAM business case"--

  19. Communities Address Barriers to Connectivity.

    Science.gov (United States)

    Byers, Anne

    1996-01-01

    Rural areas lag behind urban areas in access to information technologies. Public institutions play a critical role in extending the benefits of information technologies to those who would not otherwise have access. The most successful rural telecommunications plans address barriers to use, such as unawareness of the benefits, technophobia, the…

  20. Lab-on-chip FIA system without an external pump and valves and integrated with an in line electrochemical detector

    OpenAIRE

    Chen, I-Jane; Lindner, Ernö

    2009-01-01

    Surface energy in small droplets can be used to drive samples through micro-channels. When a sample fluid is spontaneously driven through a solution filled micro-channel with liquid droplets on its entry (sample) and exit (reservoir) ports it is termed as a passive pumping device. A passive pump driven micro-fluidic system integrated with microfabricated planar electrodes or electrode arrays (e.g., interdigitated electrode arrays, or microband electrode arrays) can be considered as a manifold...

  1. Olivine electrode engineering impact on the electrochemical performance of lithium-ion batteries.

    Energy Technology Data Exchange (ETDEWEB)

    Lu, W.; Jansen, A.; Dees, D.; Henriksen, G.; Chemical Sciences and Engineering Division

    2010-08-01

    High energy and power density lithium iron phosphate was studied for hybrid electric vehicle applications. This work addresses the effects of porosity in a composite electrode using a four-point probe resistivity analyzer, galvanostatic cycling, and electrochemical impedance spectroscopy (EIS). The four-point probe result indicates that the porosity of composite electrode affects the electronic conductivity significantly. This effect is also observed from the cell's pulse current discharge performance. Compared to the direct current (dc) methods used, the EIS data are more sensitive to electrode porosity, especially for electrodes with low porosity values.

  2. Coated carbon nanotube array electrodes

    Science.gov (United States)

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

    2008-10-28

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

  3. Ion-selective electrode reviews

    CERN Document Server

    Thomas, J D R

    1982-01-01

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

  4. Performance of lightweight nickel electrodes

    Science.gov (United States)

    Britton, Doris L.

    1988-01-01

    The NASA Lewis Research Center is currently developing nickel electrodes for nickel-hydrogen (Ni-H2) batteries. These electrodes are lighter in weight and have higher energy densities than the heavier state-of-the-art (SOA) sintered nickel electrodes. In the present approach, lightweight materials or plaques are used as conductive supports for the nickel hydroxide active material. These plaques (fiber and felt, nickel plated plastic and graphite) are commercial products that are fabricated into nickel electrodes by electrochemically impregnating them with active material. Evaluation is performed in half cells structured in the bipolar configuration. Initial performance tests include capacity measurements at five discharge levels, C/2, 1.0C, 1.37C, 2.0C and 2.74C. The electrodes that pass the initial tests are life cycle tested in a low earth orbit regime at 80 percent depth of discharge. Different formulations of nickel fiber materials obtained from several manufacturers are currently being tested as possible candidates for nickel electrodes. One particular lightweight fiber mat electrode has accumulated over 3000 cycles to date, with stable capacity and voltage. Life and performance data of this electrode were investigated and presented. Good dimensional stability and active material adherence have been demonstrated in electrodes made from this lightweight plaque.

  5. Addressing passive smoking in children.

    Directory of Open Access Journals (Sweden)

    Sasha G Hutchinson

    Full Text Available BACKGROUND: A significant number of parents are unaware or unconvinced of the health consequences of passive smoking (PS in children. Physicians could increase parental awareness by giving personal advice. AIM: To evaluate the current practices of three Dutch health professions (paediatricians, youth health care physicians, and family physicians regarding parental counselling for passive smoking (PS in children. METHODS: All physicians (n = 720 representing the three health professions in Limburg, The Netherlands, received an invitation to complete a self-administered electronic questionnaire including questions on their: sex, work experience, personal smoking habits, counselling practices and education regarding PS in children. RESULTS: The response rate was 34%. One tenth (11% of the responding physicians always addressed PS in children, 32% often, 54% occasionally and 4% reported to never attend to it. The three health professions appeared comparable regarding their frequency of parental counselling for PS in children. Addressing PS was more likely when children had respiratory problems. Lack of time was the most frequently mentioned barrier, being very and somewhat applicable for respectively 14% and 43% of the physicians. One fourth of the responders had received postgraduate education about PS. Additionally, 49% of the responders who did not have any education about PS were interested in receiving it. CONCLUSIONS: Physicians working in the paediatric field in Limburg, The Netherlands, could more frequently address PS in children with parents. Lack of time appeared to be the most mentioned barrier and physicians were more likely to counsel parents for PS in children with respiratory complaints/diseases. Finally, a need for more education on parental counselling for PS was expressed.

  6. Addressing the workforce pipeline challenge

    International Nuclear Information System (INIS)

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

  7. Addressing the workforce pipeline challenge

    Energy Technology Data Exchange (ETDEWEB)

    Leonard Bond; Kevin Kostelnik; Richard Holman

    2006-11-01

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

  8. Addressing inequities in healthy eating.

    Science.gov (United States)

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

    2015-09-01

    What, when, where and how much people eat is influenced by a complex mix of factors at societal, community and individual levels. These influences operate both directly through the food system and indirectly through political, economic, social and cultural pathways that cause social stratification and influence the quality of conditions in which people live their lives. These factors are the social determinants of inequities in healthy eating. This paper provides an overview of the current evidence base for addressing these determinants and for the promotion of equity in healthy eating. PMID:26420812

  9. Nanoscale content-addressable memory

    Science.gov (United States)

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

    2009-01-01

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

  10. Suspended electrodes for reducing parasitic capacitance in electret energy harvesters

    International Nuclear Information System (INIS)

    MEMS electret energy harvesting devices are believed promising to replace coin batteries in low-power consumption electronics such as wireless sensor nodes and wearable devices. However, the parasitic capacitance of the interdigital electrodes imposes significant restrictions to enhancing the power output. To address this issue, this paper presents a novel low-k electrode structure based on a new model of the parasitic capacitance in electret energy harvesters. By employing the trench-filled parylene technology, metal electrodes suspended with deep honeycomb parylene structures have been prototyped. Thanks to the high air volume fraction (76%) of the honeycomb parylene structure, the effective relative permittivity κeff surrounding the electrodes is reduced to as low as 1.8 when the air gap is 90 µm between the electret surface and the counter electrode. As a result, the parasitic capacitance in the electret energy harvester is decreased by 36% compared with that of electrodes on glass substrates, which leads to a 35% increase in the power output. (paper)

  11. Printed light-trapping nanorelief Cu electrodes for full-solution-processed flexible organic solar cells

    Science.gov (United States)

    Li, Kan; Zhang, Yaokang; Zhen, Hongyu; Niu, Liyong; Fang, Xu; Liu, Zhike; Yan, Feng; Shen, Weidong; Li, Haifeng; Zheng, Zijian

    2016-07-01

    Light-trapping nanorelief metal electrodes have been proven to be an effective approach to improve the absorption performance of flexible organic solar cells (FOSCs). These nanorelief electrodes have been made by conventional vacuum deposition techniques, which are difficult to integrate with roll-to-roll fabrication processes. To address this challenge, this paper reports, for the first time, the fabrication of highly conductive nanorelief Cu electrodes on the flexible substrates through solution printing and polymer-assisted metal deposition at room temperature in the air. FOSCs made with these printed nanorelief Cu electrodes possess not only much improved power conversion efficiency, by 13.5%, but also significant enhancement in flexibility when compared with those made with flat Cu electrodes. Because of the low material and fabrication cost, these printed nanorelief Cu electrodes show great promise in roll-to-roll fabrication of FOSCs in the future.

  12. Flexible Electret Energy Harvester with Copper Mesh Electrodes

    International Nuclear Information System (INIS)

    Flexible energy harvesters are desired in biomedical applications since human motion is often complicated and aperiodic. However, most demonstrated flexible energy harvesters employ piezoelectric materials which are not biocompatible. Therefore we propose a PDMS-based flexible energy harvester with Parylene-C electret suitable for biomedical applications. To address the reliability issues of sputtered metal electrodes, we use copper mesh electrodes to improve the reliability. The proposed flexible harvester was fabricated and characterized. The measured power of the proposed harvester was 3.33 pW in the compression tests at 20 Hz and 8.5 nW in the finger bending tests at 2 Hz

  13. Oxygen-Rich Enzyme Biosensor Based on Superhydrophobic Electrode.

    Science.gov (United States)

    Lei, Yongjiu; Sun, Ruize; Zhang, Xiangcheng; Feng, Xinjian; Jiang, Lei

    2016-02-17

    The fabrication of novel superhydrophobic electrodes is described, which have an air-liquid-solid three-phase interface, where oxygen is sufficient and constant. Oxygen is an effective natural electron acceptor for oxidase, and plays a key role in the development of reliable bioassays. Such an electrode allows detection of glucose concentration, linearly from 50 × 10(-9) m to 156 × 10(-3) m with good sensitivity and accuracy without analyte dilution. This strategy offers a unique route to address the gas-deficit problem of many reaction systems. PMID:26661886

  14. Making EDM Electrodes By Stereolithography

    Science.gov (United States)

    Barlas, Philip A.

    1988-01-01

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

  15. EDM Electrode for Internal Grooves

    Science.gov (United States)

    Ramani, V.; Werner, A.

    1985-01-01

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

  16. Electrode for a lithium cell

    Science.gov (United States)

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

    2008-10-14

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

  17. Addressing viral resistance through vaccines

    Science.gov (United States)

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

    2015-01-01

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

  18. Addressing failures in exascale computing

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-05-01

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

  19. Addressing Failures in Exascale Computing

    Energy Technology Data Exchange (ETDEWEB)

    Snir, Marc [Argonne National Laboratory (ANL); Wisniewski, Robert [Intel Corporation; Abraham, Jacob [unknown; Adve, Sarita [University of Illinois, Urbana-Champaign; Bagchi, Saurabh [Purdue University; Balaji, Pavan [Argonne National Laboratory (ANL); Belak, J. [Lawrence Livermore National Laboratory (LLNL); Bose, Pradip [IBM T. J. Watson Research Center; Cappello, Franck [Argonne National Laboratory (ANL); Carlson, Bill [unknown; Chien, Andrew [University of Chicago; Coteus, Paul [IBM T. J. Watson Research Center; DeBardeleben, Nathan [Los Alamos National Laboratory (LANL); Diniz, Pedro [University of Southern California; Engelmann, Christian [ORNL; Erez, Mattan [University of Texas at Austin; Fazzari, Saverio [Booz Allen Hamilton; Geist, Al [ORNL; Gupta, Rinku [Argonne National Laboratory (ANL); Johnson, Fred [Science Applications International Corporation (SAIC), Oak Ridge, TN; Krishnamoorthy, Sriram [Pacific Northwest National Laboratory (PNNL); Leyffer, Sven [Argonne National Laboratory (ANL); Liberty, Dean [AMD; Mitra, Subhasish [Stanford University; Munson, Todd [Argonne National Laboratory (ANL); Schreiber, Rob [HP Labs; Stearley, Jon [Sandia National Laboratories (SNL); Van Hensbergen, Eric [ARM

    2014-01-01

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

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

    Science.gov (United States)

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

    2015-12-01

    Defibrillation is the standard clinical treatment used to stop ventricular fibrillation. An electrical device delivers a controlled amount of electrical energy via a pair of electrodes in order to reestablish a normal heart rate. We propose a technique that is a combination of biphasic shocks applied with a four-electrode system rather than the standard two-electrode system. We use a numerical model of a one-dimensional ring of cardiac tissue in order to test and evaluate the benefit of this technique. We compare three different shock protocols, namely a monophasic and two types of biphasic shocks. The results obtained by using a four-electrode system are compared quantitatively with those obtained with the standard two-electrode system. We find that a huge reduction in defibrillation threshold is achieved with the four-electrode system. For the most efficient protocol (asymmetric biphasic), we obtain a reduction in excess of 80% in the energy required for a defibrillation success rate of 90%. The mechanisms of successful defibrillation are also analyzed. This reveals that the advantage of asymmetric biphasic shocks with four electrodes lies in the duration of the cathodal and anodal phase of the shock. PMID:26764786

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

    Science.gov (United States)

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

    2015-12-01

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

  2. Building Footprints - Montana Structures/Addresses Framework

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — The Montana Structures/Addresses Framework is a statewide spatial database of structure and address points in the State of Montana. The Montana Structures/Addresses...

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

    DEFF Research Database (Denmark)

    Jacobsen, Torben

    In the development of new electrode materials for high temperature Solid Oxide Fuel Cells methods are needed for the electrochemical evaluation of the catalytic properties of the materials. A major problem in the comparison of materials is how to determine the geometry and the effective length......\\parbox[t]{7.3cm}{Strong anodic activation due to computer communication error.} It is seen that as long as the electrode is kept at the equilibrium potential, the capacity pr.\\,unit area is constant, indicating a stable reaction zone. Polarising the electrode a decrease in this ratio is observed. Although...

  4. Addressing neurological disorders with neuromodulation.

    Science.gov (United States)

    Oluigbo, Chima O; Rezai, Ali R

    2011-07-01

    Neurological disorders are becoming increasingly common in developed countries as a result of the aging population. In spite of medications, these disorders can result in progressive loss of function as well as chronic physical, cognitive, and emotional disability that ultimately places enormous emotional and economic on the patient, caretakers, and the society in general. Neuromodulation is emerging as a therapeutic option in these patients. Neuromodulation is a field, which involves implantable devices that allow for the reversible adjustable application of electrical, chemical, or biological agents to the central or peripheral nervous system with the objective of altering its functioning with the objective of achieving a therapeutic or clinically beneficial effect. It is a rapidly evolving field that brings together many different specialties in the fields of medicine, materials science, computer science and technology, biomedical, and neural engineering as well as the surgical or interventional specialties. It has multiple current and emerging indications, and an enormous potential for growth. The main challenges before it are in the need for effective collaboration between engineers, basic scientists, and clinicians to develop innovations that address specific problems resulting in new devices and clinical applications.

  5. MHD Electrode and wall constructions

    Science.gov (United States)

    Way, Stewart; Lempert, Joseph

    1984-01-01

    Electrode and wall constructions for the walls of a channel transmitting the hot plasma in a magnetohydrodynamic generator. The electrodes and walls are made of a plurality of similar modules which are spaced from one another along the channel. The electrodes can be metallic or ceramic, and each module includes one or more electrodes which are exposed to the plasma and a metallic cooling bar which is spaced from the plasma and which has passages through which a cooling fluid flows to remove heat transmitted from the electrode to the cooling bar. Each electrode module is spaced from and electrically insulated from each adjacent module while interconnected by the cooling fluid which serially flows among selected modules. A wall module includes an electrically insulating ceramic body exposed to the plasma and affixed, preferably by mechanical clips or by brazing, to a metallic cooling bar spaced from the plasma and having cooling fluid passages. Each wall module is, similar to the electrode modules, electrically insulated from the adjacent modules and serially interconnected to other modules by the cooling fluid.

  6. Capacitance enhancement via electrode patterning.

    Science.gov (United States)

    Ho, Tuan A; Striolo, Alberto

    2013-11-28

    The necessity of increasing the energy density in electric double layer capacitors to meet current demand is fueling fundamental and applied research alike. We report here molecular dynamics simulation results for aqueous electrolytes near model electrodes. Particular focus is on the effect of electrode patterning on the structure of interfacial electrolytes, and on the potential drop between the solid electrodes and the bulk electrolytes. The latter is estimated by numerically integrating the Poisson equation using the charge densities due to water and ions accumulated near the interface as input. We considered uniform and patterned electrodes, both positively and negatively charged. The uniformly charged electrodes are modeled as graphite. The patterned ones are obtained by removing carbon atoms from the top-most graphene layer, yielding nanoscopic squares and stripes patterns. For simplicity, the patterned electrodes are effectively simulated as insulators (the charge remains localized on the top-most layer of carbon atoms). Our simulations show that the patterns alter the structure of water and the accumulation of ions at the liquid-solid interfaces. Using aqueous NaCl solutions, we found that while the capacitance calculated for three positively charged electrodes did not change much, that calculated for the negatively charged electrodes significantly increased upon patterning. We find that both water structure and orientation, as well as ion accumulation affect the capacitance. As electrode patterning affects differently water structure and ion accumulation, it might be possible to observe ion-specific effects. These results could be useful for advancing our understanding of electric double layer capacitors, capacitive desalination processes, as well as of fundamental interfacial electrolytes properties. PMID:24289370

  7. Modified nickel electrodes: a review

    International Nuclear Information System (INIS)

    Catalysts in the form of electrode surfaces offer the added dimension of the electrode potential which can be used to manage the catalyst reactivity and in some cases selectivity. The catalytic effect of nickel oxyhydroxide for the electrochemical determination of organics in alkaline media is very common. This has also received substantial thought because of the application of Ni in rechargeable alkaline batteries. This subject matter has been reviewed from different views before. The present review depicts the role of additives and the modifiers towards the enhancement of electro catalytic properties of electrode surface. (author)

  8. Addressing verification challenges [International safeguards symposium on addressing verification challenges

    International Nuclear Information System (INIS)

    In his welcome address the Director General of the International Atomic Energy Agency (IAEA), Mr. M. ElBaradei, stated that safeguards activities are probably the most difficult task entrusted to an international organization and to determine all the details of a country's nuclear programme is a daunting challenge that raises a number of questions. There is an increase in nuclear power around the globe as a result of shortages of energy and concerns about energy independence and climate change. On the one hand, this is good, because without energy there is no hope for development on the other hand, however, it means that nuclear know-how and nuclear technology will continue to spread to more and more countries. There is also an increase in the number of countries interested in developing nuclear fuel cycle capabilities: sensitive fuel cycle activities, reprocessing and above all uranium enrichment. It even seems that some countries might be hedging their bets in order to have the know-how should they need to develop their own deterrence. Verifying enrichment or reprocessing facilities is quite difficult, and the so-called conversion time is extremely short. Thus, the IAEA is dealing with what is called 'virtual nuclear weapon States'. The IAEA has been talking for a number of years about the need to develop a new international or multinational approach to the fuel cycle in order to avoid a situation with nine nuclear weapon States and another 20 or 30 States having the capacity to develop nuclear weapons in a very short period of time. There is a need to remember that there is a linkage between nuclear disarmament and non-proliferation. Furthermore safeguards activities, though fundamentally technical in nature, are carried out in a political charged environment. The security dimension - that is, nuclear terrorism - also presents a new challenge, because State systems of accounting for and control of nuclear material are no longer simply tools for safeguards, but

  9. High-fidelity spatial addressing of Ca-43 qubits using near-field microwave control

    CERN Document Server

    Craik, D P L Aude; Sepiol, M A; Harty, T P; Ballance, C J; Stacey, D N; Steane, A M; Lucas, D M; Allcock, D T C

    2016-01-01

    Individual addressing of qubits is essential for scalable quantum computation. Spatial addressing allows unlimited numbers of qubits to share the same frequency, whilst enabling arbitrary parallel operations. We demonstrate addressing of long-lived $^{43}\\text{Ca}^+$ "atomic clock" qubits held in separate zones of a microfabricated surface trap with integrated microwave electrodes. By coherently cancelling the microwave field in one zone we measure a ratio of Rabi frequencies between addressed and non-addressed qubits of up to 1400, implying an addressing error of $1.3\\times 10^{-6}$. Off-resonant excitation prevents this error level being directly demonstrated, but we also show polarization control of the microwave field with error $2\\times 10^{-5}$, sufficient to suppress off-resonant excitation out of the qubit states to the $\\sim 10^{-9}$ level. Such polarization control could enable fast microwave operations.

  10. Polypyrrole electrodes doped with sulfanilic acid azochromotrop for electrochemical supercapacitors

    Science.gov (United States)

    Chen, S.; Zhitomirsky, I.

    2013-12-01

    In this work we demonstrate the feasibility of deposition of polypyrrole (PPy) films by electropolymerization on stainless steel substrates and fabrication of PPy powders by chemical polymerization using sulfanilic acid azochromotrop (SPADNS) as a new anionic dopant. The problem of low adhesion of PPy films to stainless steel substrates is addressed by the use of SPADNS, which exhibits chelating properties, promoting film formation. The use of fine particles, prepared by the chemical polymerization method, allows impregnation of Ni foams and fabrication of porous electrodes with high materials loading for electrochemical supercapacitors (ES). PPy films and Ni foam based PPy electrodes show capacitive behaviour in Na2SO4 electrolyte. The electron microscopy studies, impedance spectroscopy data and analysis of the SPADNS structure provide an insight into the factors, controlling capacitive behaviour. The Ni foam based electrodes offer advantages of improved capacitive behaviour at high materials loadings and good cycling stability. The area normalized and volume normalized specific capacitances are as high as 5.43 F cm-2 and 93.6 F cm-3, respectively, for materials loading of 35.4 mg cm-2. The capacitance retention of Ni foam based electrodes is 91.5% after 1000 cycles. The Ni foam based PPy electrodes are promising for application in ES.

  11. Fabrication of Out-of-Plane Electrodes for ACEO Pumps

    Science.gov (United States)

    Senousy, Yehya; Harnett, Cindy

    2012-02-01

    This abstract reports the fabrication process of a novel AC Electrosmosis (ACEO) pump with out of plane asymmetric interdigitated electrodes. A self-folding technique is used to fabricate the electrodes, that depends on the strain mismatch between the tensile stressed film (metal layer) and the compressive stress film (oxidized silicon layer). The electrodes roll up with a well-defined radius of curvature in the range of 100-200 microns. Two different electrical signals are connected to alternating electrodes using an insulating silicon nitride barrier that allows circuits to cross over each other without shorting. Electroosmotic micropumps are essential for low-cost, power-efficient microfluidic lab-on-chip devices used in diverse application such as analytical probes, drug delivery systems and surgical tools. ACEO pumps have been developed to address the drawbacks of the DCEO pumps such as the faradic reaction and gas bubbles. The original ACEO microfluidic pump was created with planar arrays of asymmetric interdigitated electrodes at the bottom of the channel. This rolled-up tube design improves on the planar design by including the channel walls and ceiling in the active pumping surface area of the device.

  12. An address geocoding solution for Chinese cities

    Science.gov (United States)

    Zhang, Xuehu; Ma, Haoming; Li, Qi

    2006-10-01

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

  13. Towards high-resolution retinal prostheses with direct optical addressing and inductive telemetry

    Science.gov (United States)

    Ha, Sohmyung; Khraiche, Massoud L.; Akinin, Abraham; Jing, Yi; Damle, Samir; Kuang, Yanjin; Bauchner, Sue; Lo, Yu-Hwa; Freeman, William R.; Silva, Gabriel A.; Cauwenberghs, Gert

    2016-10-01

    Objective. Despite considerable advances in retinal prostheses over the last two decades, the resolution of restored vision has remained severely limited, well below the 20/200 acuity threshold of blindness. Towards drastic improvements in spatial resolution, we present a scalable architecture for retinal prostheses in which each stimulation electrode is directly activated by incident light and powered by a common voltage pulse transferred over a single wireless inductive link. Approach. The hybrid optical addressability and electronic powering scheme provides separate spatial and temporal control over stimulation, and further provides optoelectronic gain for substantially lower light intensity thresholds than other optically addressed retinal prostheses using passive microphotodiode arrays. The architecture permits the use of high-density electrode arrays with ultra-high photosensitive silicon nanowires, obviating the need for excessive wiring and high-throughput data telemetry. Instead, the single inductive link drives the entire array of electrodes through two wires and provides external control over waveform parameters for common voltage stimulation. Main results. A complete system comprising inductive telemetry link, stimulation pulse demodulator, charge-balancing series capacitor, and nanowire-based electrode device is integrated and validated ex vivo on rat retina tissue. Significance. Measurements demonstrate control over retinal neural activity both by light and electrical bias, validating the feasibility of the proposed architecture and its system components as an important first step towards a high-resolution optically addressed retinal prosthesis.

  14. High-fidelity spatial addressing of 43Ca+ qubits using near-field microwave control

    Science.gov (United States)

    Prado Lopes Aude Craik, Diana; Linke, Norbert; Allcock, David; Sepiol, Martin; Harty, Thomas; Ballance, Christopher; Stacey, Derek; Steane, Andrew; Lucas, David

    2016-05-01

    Individual addressing of qubits is essential for scalable quantum computation. Spatial addressing allows unlimited numbers of qubits to share the same frequency, whilst enabling arbitrary parallel operations. We present the latest experimental results obtained using a two-zone microfabricated surface trap designed to perform spatial, near-field microwave addressing of long-lived 43Ca+ ``atomic clock'' qubits held in separate trap zones (each of which feature four integrated microwave electrodes). Microwave near fields generated by multi-electrode chip ion traps are often difficult to faithfully simulate and a simple method of characterizing and testing trap chips before placement under ultra-high vacuum would significantly speed up trap design optimization. We describe a printed circuit board antenna for use in mapping microwave near-fields generated by ion-trap electrodes. The antenna is designed to measure fields down to 100 μ m away from trap electrodes and to be impedance matched at a desired spot frequency for an improved signal to noise ratio in field measurements. This work is supported by the US Army Research Office, EPSRC (UK) and the UK National Quantum Technologies Programme.

  15. Composite Electrodes for Electrochemical Supercapacitors

    OpenAIRE

    Yang QuanMin; Li Jun; Zhitomirsky Igor

    2010-01-01

    Abstract Manganese dioxide nanofibers with length ranged from 0.1 to 1 μm and a diameter of about 4–6 nm were prepared by a chemical precipitation method. Composite electrodes for electrochemical supercapacitors were fabricated by impregnation of the manganese dioxide nanofibers and multiwalled carbon nanotubes (MWCNT) into porous Ni plaque current collectors. Obtained composite electrodes, containing 85% of manganese dioxide and 15 mass% of MWCNT, as a conductive additive, with to...

  16. Effects of Electrode Material on the Voltage of a Tree-Based Energy Generator.

    Directory of Open Access Journals (Sweden)

    Zhibin Hao

    Full Text Available The voltage between a standing tree and its surrounding soil is regarded as an innovative renewable energy source. This source is expected to provide a new power generation system for the low-power electrical equipment used in forestry. However, the voltage is weak, which has caused great difficulty in application. Consequently, the development of a method to increase the voltage is a key issue that must be addressed in this area of applied research. As the front-end component for energy harvesting, a metal electrode has a material effect on the level and stability of the voltage obtained. This study aimed to preliminarily ascertain the rules and mechanisms that underlie the effects of electrode material on voltage. Electrodes of different materials were used to measure the tree-source voltage, and the data were employed in a comparative analysis. The results indicate that the conductivity of the metal electrode significantly affects the contact resistance of the electrode-soil and electrode-trunk contact surfaces, thereby influencing the voltage level. The metal reactivity of the electrode has no significant effect on the voltage. However, passivation of the electrode materials markedly reduces the voltage. Suitable electrode materials are demonstrated and recommended.

  17. Initial experiments with flexible conductive electrodes for potential applications in cancer tissue screening

    Science.gov (United States)

    Chung, Daehan; Seyfollahi, Sam; Khosla, Ajit; Gray, Bonnie; Parameswaran, Ash; Ramaseshan, Ramani; Kohli, Kirpal

    2011-02-01

    We present initial results on the fabrication and testing of micropatternable conductive nanocomposite polymer (C-NCP) electrodes for tissue impedance measurements. We present these proof-of-concept results as a first step toward the realization of our goal: an improved Electrical Impedance Scanning (EIS) system, whereby tissue can be scanned for cancerous tissue and other anomalies using large arrays of highly flexible microfabricated electrodes. Previous limitations of existing EIS system are addressed by applying polymer based microelectromechanical system (MEMS) technology. In particular, we attempt to minimize mechanical skin contact issues through the use of highly compliant elastomeric polymers, and increase the spatial resolution of measurements through the development of microelectrodes that can be micropatterned into large, highly dense arrays. We accomplish these improvements through the development of C-NCP electrodes that employ silver nanoparticle fillers in an elastomer polymer base that can be easily patterned using conventional soft lithography techniques. These new electrodes are tested on conventional tissue phantoms that mimic the electrical characteristics of human tissue. We characterize the conductivity of the electrodes (average resistivity of 7x10-5 ohm-m +/- 14.3% at 60 wt-% of silver nanoparticles), and further employ the electrodes for impedance characterization via Cole-Cole plots to show that measurements employing C-NCP electrodes are comparable to those obtained with normal macroscopic metal electrodes. We also demonstrate anomaly detection using our highly flexible Ag/AgCl C-NCP electrodes on a tissue phantom.

  18. Stimulation and recording electrodes for neural prostheses

    CERN Document Server

    Pour Aryan, Naser; Rothermel, Albrecht

    2015-01-01

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

  19. Systems and methods for the magnetic insulation of accelerator electrodes in electrostatic accelerators

    Science.gov (United States)

    Grisham, Larry R

    2013-12-17

    The present invention provides systems and methods for the magnetic insulation of accelerator electrodes in electrostatic accelerators. Advantageously, the systems and methods of the present invention improve the practically obtainable performance of these electrostatic accelerators by addressing, among other things, voltage holding problems and conditioning issues. The problems and issues are addressed by flowing electric currents along these accelerator electrodes to produce magnetic fields that envelope the accelerator electrodes and their support structures, so as to prevent very low energy electrons from leaving the surfaces of the accelerator electrodes and subsequently picking up energy from the surrounding electric field. In various applications, this magnetic insulation must only produce modest gains in voltage holding capability to represent a significant achievement.

  20. Design of an impeller-mounted electrode array for EIT imaging

    International Nuclear Information System (INIS)

    The information content in electrical impedance tomography (EIT) reconstructions is limited by the number of independent impedance measurements acquired for each image frame. This paper describes the design and construction of an electrode array mounted onto a rotating impeller used for mixing processes. By combining the process compliant rotation of the electrodes with a dynamic measurement protocol, a substantial increase in the number of independent measurements is reported. A pitch-blade impeller is built and fitted with four electrodes. A number of challenges associated with operating a rotating electrode array have been addressed including a wireless communications protocol. The impeller has been accurately modelled and measurement simulations closely correspond to those acquired using the array. The apparatus has been used to successfully visualize a test distribution to a consistent standard compared to a conventional EIT electrode array and strategy. Presently, the limiting factor to this approach is the necessary high measurement acquistion rates which lead to restricted impeller velocities

  1. Extraction electrode geometry for a calutron

    Science.gov (United States)

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

    1975-09-23

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

  2. E6 Addressing Scheme and Network Architecture

    OpenAIRE

    Dmitry Anatolyevich Zaitsev; Sergey Ivanovich Bolshakov

    2012-01-01

    The paper describes new E6 addressing scheme for the creation of world-wide networks totally constructed on the base of Ethernet technology. Hierarchic E6 addresses with the length of 6 octets are used instead of both Ethernet MAC-addresses and IP-addresses that allows the routing within world-wide networks and cuts overhead of TCP, IP headers; the address space is extended in 16K times regarding IP addresses. Standard Ethernet LLC2 facilities are employed for guaranteed delivery of informati...

  3. Communications: Elementary oxygen electrode reactions in the aprotic Li-air battery

    Science.gov (United States)

    Hummelshøj, J. S.; Blomqvist, J.; Datta, S.; Vegge, T.; Rossmeisl, J.; Thygesen, K. S.; Luntz, A. C.; Jacobsen, K. W.; Nørskov, J. K.

    2010-02-01

    We discuss the electrochemical reactions at the oxygen electrode of an aprotic Li-air battery. Using density functional theory to estimate the free energy of intermediates during the discharge and charge of the battery, we introduce a reaction free energy diagram and identify possible origins of the overpotential for both processes. We also address the question of electron conductivity through the Li2O2 electrode and show that in the presence of Li vacancies Li2O2 becomes a conductor.

  4. A Novel Approach for TNA Address Management

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    We present a new scheme to allocate/de-allocate Transport Network Assigned (TN A) address using Link Management Protocol (LMP) and to register/resolution these addresses using Lightweight Directory Access Protocol (LDAP) for Automatically Switched Optical Network (ASON).

  5. SAVI: The IETF Standard in Address Validation

    OpenAIRE

    Bagnulo, Marcelo; García-Martínez, Alberto

    2013-01-01

    In this article we describe Source Address Validation Implementation (SAVI), a security architecture being standardized by the IETF to prevent source address spoofing within a link. SAVI devices, usually layer 2 switches, create bindings between the IP address of a node and a property of the host¿s network attachment, such as the port through which the packet is received. Bindings are created by monitoring the packet exchange associated with IP address configuration mechanisms such as DHCP, S...

  6. Address allocation to mobile ad hoc networks

    OpenAIRE

    Sakander, Zeeshan

    2006-01-01

    Addressing in MANETs is of significant importance, as a mobile device cannot participate in unicast communications until it is assigned a conflict-free IP address. All routing protocols assume nodes to be configured a priori with a unique IP address. Allocating addresses to mobile nodes is a fundamental and difficult problem. Unlike infrastructure based networks, MANETs support autonomous and spontaneous networking and therefore, should be capable of self-organization and self-configuration. ...

  7. 32 CFR 516.7 - Mailing addresses.

    Science.gov (United States)

    2010-07-01

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

  8. Highly Robust Silver Nanowire Network for Transparent Electrode.

    Science.gov (United States)

    Song, Tze-Bin; Rim, You Seung; Liu, Fengmin; Bob, Brion; Ye, Shenglin; Hsieh, Yao-Tsung; Yang, Yang

    2015-11-11

    Solution-processed silver nanowire networks are one of the promising candidates to replace a traditional indium tin oxide as next-generation transparent and flexible electrodes due to their ease of processing, moderate flexibility, high transparency, and low sheet resistance. To date, however, high stability of the nanowire networks remains a major challenge because the long-term usages of these electrodes are limited by their poor thermal and chemical stabilities. Existing methods for addressing this challenge mainly focus on protecting the nanowire network with additional layers that require vacuum processes, which can lead to an increment in manufacturing cost. Here, we report a straightforward strategy of a sol-gel processing as a fast and robust way to improve the stabilities of silver nanowires. Compared with reported nanoparticles embedded in nanowire networks, better thermal and chemical stabilities are achieved via sol-gel coating of TiO2 over the silver nanowire networks. The conformal surface coverage suppressed surface diffusion of silver atoms and prevented chemical corrosion from the environment. These results highlight the important role of the functional layer in providing better thermal and chemical stabilities along with improved electrical properties and mechanical robustness. The silver nanowire/TiO2 composite electrodes were applied as the source and drain electrodes for In2O3 thin-film transistors (TFTs) and the devices exhibited improved electrical performance annealed at 300 °C without the degradation of the electrodes. These key findings not only demonstrated a general and effective method to improve the thermal and chemical stabilities of metal nanowire networks but also provided a basic guideline toward rational design of highly efficient and robust composite electrodes. PMID:26488682

  9. 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

  10. Composite Electrodes for Electrochemical Supercapacitors

    Science.gov (United States)

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

    2010-03-01

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

  11. Composite Electrodes for Electrochemical Supercapacitors

    Directory of Open Access Journals (Sweden)

    Yang QuanMin

    2010-01-01

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

  12. Nonequilibrium Thermodynamics of Porous Electrodes

    CERN Document Server

    Ferguson, Todd R

    2012-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-02-02

    In one aspect of the present invention, a fuel cell membrane-electrode-assembly (MEA) has an anode electrode, a cathode electrode, and a membrane disposed between the anode electrode and the cathode electrode. At least one of the anode electrode, the cathode electrode and the membrane is formed of electrospun nanofibers.

  14. Improving IPV6 Addressing Types and Size

    Directory of Open Access Journals (Sweden)

    Khaldoun Batiha

    2013-07-01

    Full Text Available IPv6 protocol is the next candidate protocol after IPv4 protocolthatused foralong time. For this protocoltheaddressing types and address sizeare discussedto list some modifications that could improve itsperformancethrough the internet. Atthe same time, we prove that multicast addressing type is the mostimportant addressing type since it can mimic any other addressing type. Finally,a short studyis developedin order to reduce the current IPv6 address size to haveless overhead in the basic header packet, thisreductionomitsabout 40% of the over all basic IPv6 basic packet overhead.

  15. Nanoengineered membrane electrode assembly interface

    Science.gov (United States)

    Song, Yujiang; Shelnutt, John A

    2013-08-06

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

  16. Ceramic components for MHD electrode

    Science.gov (United States)

    Marchant, D.D.

    A ceramic component which exhibits electrical conductivity down to near room temperatures has the formula: Hf/sub x/In/sub y/A/sub z/O/sub 2/ where x = 0.1 to 0.4, y = 0.3 to 0.6, z = 0.1 to 0.4 and A is a lanthanide rare earth or yttrium. The component is suitable for use in the fabrication of MHD electrodes or as the current leadout portion of a composite electrode with other ceramic components.

  17. A micro-fluidic sub-microliter sample introduction system for direct analysis of Chinese rice wine by inductively coupled plasma mass spectrometry using external aqueous calibration

    International Nuclear Information System (INIS)

    A microfluidic sub-microliter sample introducing system was developed for direct analysis of Chinese rice wine by inductively coupled plasma mass spectrometry (ICP-MS). It consisted of a microfluidic chip integrating variable-volume sampling channels (0.1–0.8 μL), an eight-way multi-functional valve used in flow injection analysis (FIA), a syringe pump and a peristaltic pump of the Ar ICP-MS instrument. Three solutions, i.e., 15, 40 and 100 g L−1 glucose in 20% ethanol were used to simulate Chinese rice wine of the dry type, the semidry type and the semisweet type, each. The effects of their volume introduced into ICP-MS on the plasma stability and ICP-MS intensities were studied. The experimental results showed that neither alteration of plasma stability nor carbon deposition was observed when the sampling volume of 20% ethanol containing 100 g L−1 glucose was downscaled to 0.8 μL. Further reducing the sampling volume to 0.4 μL, no significant difference between the intensities of multi-element standard prepared in three simulated Chinese rice wine matrices and those in aqueous solution was observed. It indicated no negative effect of Chinese rice wine matrix on the ICP-MS intensities. A sampling volume of 0.4 μL was considered to be a good compromise between sensitivity and matrix effect. The flow rate of the carrier was chosen as 20 μL min−1 for obtaining peaks with the highest peak height within the shortest time. Based on these observations, a microflow injection (μFI) method for the direct determination of cadmium and lead in Chinese rice wine by ICP-MS using an external aqueous calibration was developed. The sample throughput was 45 h−1 with the detection limit of 19.8 and 10.4 ng L−1 for Cd and Pb, respectively. The contents of Cd and Pb in 10 Chinese rice wine samples were measured. The results agreed well with those determined by ICP-MS with the conventional sampling system after microwave assisted digestion. The recoveries of three Chinese rice wine samples ranged between 95.5 and 102.8%. Furthermore, the determined contents of Cd and Pb in a certified reference material of red wine (GBW 10031) and a quality control test material of wine (FAPAS T07163QC) by the proposed method were in fairly good accordance with the certified/assigned values. All results verified the accuracy of our method. - Highlights: ► A microfluidic sub-microliter sample introduction system was developed for ICP-MS. ► Direct analysis of Chinese rice wine by ICP-MS was achieved. ► No carbon deposit or matrix effect from Chinese rice wine was observed.

  18. A novel micro fluidic mixer-based approach for determining inactivation kinetics of Escherichia coli O157:H7 in free chlorine solutions

    Science.gov (United States)

    Determination of the minimum free chlorine concentration needed to prevent pathogen survival/cross-contamination during produce washing is a critical need to develop science-based food safety regulations and practices. Although the trend of chlorine concentration-contact time on pathogen inactivatio...

  19. A micro-fluidic sub-microliter sample introduction system for direct analysis of Chinese rice wine by inductively coupled plasma mass spectrometry using external aqueous calibration

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Heyong [Institute of Microanalytical Systems, Department of Chemistry, Zhejiang University, Hangzhou, 310027 (China); College of Material Chemistry and Chemical Engineering, Hangzhou Normal University, Hangzhou, 310036 (China); Liu, Jinhua [College of Material Chemistry and Chemical Engineering, Hangzhou Normal University, Hangzhou, 310036 (China); Xu, Zigang [Institute of Analytical and Applied Chemistry, Department of Chemistry, Zhejiang University, Hangzhou, 310027 (China); Yin, Xuefeng, E-mail: yinxf@zju.edu.cn [Institute of Microanalytical Systems, Department of Chemistry, Zhejiang University, Hangzhou, 310027 (China); College of Material Chemistry and Chemical Engineering, Hangzhou Normal University, Hangzhou, 310036 (China)

    2012-07-15

    A microfluidic sub-microliter sample introducing system was developed for direct analysis of Chinese rice wine by inductively coupled plasma mass spectrometry (ICP-MS). It consisted of a microfluidic chip integrating variable-volume sampling channels (0.1-0.8 {mu}L), an eight-way multi-functional valve used in flow injection analysis (FIA), a syringe pump and a peristaltic pump of the Ar ICP-MS instrument. Three solutions, i.e., 15, 40 and 100 g L{sup -1} glucose in 20% ethanol were used to simulate Chinese rice wine of the dry type, the semidry type and the semisweet type, each. The effects of their volume introduced into ICP-MS on the plasma stability and ICP-MS intensities were studied. The experimental results showed that neither alteration of plasma stability nor carbon deposition was observed when the sampling volume of 20% ethanol containing 100 g L{sup -1} glucose was downscaled to 0.8 {mu}L. Further reducing the sampling volume to 0.4 {mu}L, no significant difference between the intensities of multi-element standard prepared in three simulated Chinese rice wine matrices and those in aqueous solution was observed. It indicated no negative effect of Chinese rice wine matrix on the ICP-MS intensities. A sampling volume of 0.4 {mu}L was considered to be a good compromise between sensitivity and matrix effect. The flow rate of the carrier was chosen as 20 {mu}L min{sup -1} for obtaining peaks with the highest peak height within the shortest time. Based on these observations, a microflow injection ({mu}FI) method for the direct determination of cadmium and lead in Chinese rice wine by ICP-MS using an external aqueous calibration was developed. The sample throughput was 45 h{sup -1} with the detection limit of 19.8 and 10.4 ng L{sup -1} for Cd and Pb, respectively. The contents of Cd and Pb in 10 Chinese rice wine samples were measured. The results agreed well with those determined by ICP-MS with the conventional sampling system after microwave assisted digestion. The recoveries of three Chinese rice wine samples ranged between 95.5 and 102.8%. Furthermore, the determined contents of Cd and Pb in a certified reference material of red wine (GBW 10031) and a quality control test material of wine (FAPAS T07163QC) by the proposed method were in fairly good accordance with the certified/assigned values. All results verified the accuracy of our method. - Highlights: Black-Right-Pointing-Pointer A microfluidic sub-microliter sample introduction system was developed for ICP-MS. Black-Right-Pointing-Pointer Direct analysis of Chinese rice wine by ICP-MS was achieved. Black-Right-Pointing-Pointer No carbon deposit or matrix effect from Chinese rice wine was observed.

  20. Evaluation of cell lysis procedures and use of a micro fluidic system for an automated DNA-based cell identification in interplanetary missions

    Science.gov (United States)

    Hall, J. A.; Felnagle, E.; Fries, M.; Spearing, S.; Monaco, L.; Steele, A.

    2006-12-01

    A Modular Assay System for Solar System Exploration (MASSE) is being developed to include sample handling, pre-treatment, separation and analysis of biological target compounds by both DNA and protein microarrays. To better design sensitive and accurate initial upstream sample handling of the MASSE instrument, experiments investigating the sensitivity and potential extraction bias of commercially available DNA extraction kits between classes of environmentally relevant prokaryotes such as gram-negative bacteria ( Escherichia coli), gram-positive bacteria ( Bacillus megatarium), and Archaea ( Haloarcula marismortui) were performed. For extractions of both planktonic cultures and spiked Mars simulated regolith, FTA ® paper demonstrated the highest sensitivity, with detection as low as ˜1×10 1 cells and ˜3.3×10 2 cells, respectively. In addition to the highest sensitivity, custom modified application of FTA ® paper extraction protocol is the simplest in terms of incorporation into MASSE and displayed little bias in sensitivity with respect to prokaryotic cell type. The implementation of FTA paper for environmental microbiology investigations appears to be a viable and effective option potentially negating the need for other pre-concentration steps such as filtration and negating concerns regarding extraction efficiency of cells. In addition to investigations on useful technology for upstream sample handling in MASSE, we have also evaluated the potential for μTAS to be employed in the MASSE instrument by employing proprietary lab-on-a-chip development technology to investigate the potential for microfluidic cell lysis of different prokaryotic cells employing both chemical and biological lysis agents. Real-time bright-field microscopy and quantitative PMT detection indicated that that gram positive, gram negative and archaeal cells were effectively lyzed in a few seconds using the microfluidic chip protocol developed. This included employing a lysis buffer with components including lysozyme, Protease, Proteinase K, Tween-20 and TritonX-100. The effectiveness of antibiotics and other chemical lysis agents were also screened and demonstrated partial effectiveness on all three cell types. This work demonstrates a step wise approach to evaluating the efficacy and sensitivity of commercial macro-scale technology and state-of-the-art developmental microfluidic technology under consideration for incorporation into the remotely operated MASSE instrument currently under development at the Carnegie Institution of Washington.

  1. Recent developments in the NSWC composite electrode

    Science.gov (United States)

    Ferrando, W. A.

    1982-03-01

    A characterization of the physical parameters and life cycle data on nickel composite electrodes was conducted. Attempts to improve the nickel composite electrodes with respect to longevity, light weight, and low cost were made. The physical characteristics of a group of electrodes were examined with emphasis on the porosity of the plaques, the thickness of the electrodes, and the potential presence of electrolytes contamination. It was concluded that the nickel composite electrodes exhibit good life cycle characteristics and that their fabrication seems to present real possibilities for the future as a method of making electrodes that are durable, lightweight, and low cost.

  2. Analysis of SOFCs Using Reference Electrodes

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-01-01

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

  3. Optimization of Electrode Channels in Brain Computer Interfaces

    Science.gov (United States)

    Kamrunnahar, M.; Dias, N. S.; Schiff, S. J.

    2010-01-01

    What is the optimal number of electrodes one can use in discrimination of tasks for a Brain Computer Interface(BCI)? To address this question, the number and location of scalp electrodes in the acquisition of human electroencephalography (EEG) and discrimination of motor imagery tasks were optimized by using a systematic optimization approach. The systematic analysis results in the most reliable procedure in electrode optimization as well as a validating means for the other feature selection techniques. We acquired human scalp EEG in response to cue-based motor imagery tasks. We employed a systematic analysis by using all possible combinations of the channels and calculating task discrimination errors for each of these combinations by using linear discriminant analysis (LDA) for feature classification. Channel combination that resulted in the smallest discrimination error was selected as the optimum number of channels to be used in BCI applications. Results from the systematic analysis were compared with another feature selection algorithm: forward stepwise feature selection combined with LDA feature classification. Our results demonstrate the usefulness of the fully optimized technique for a reliable selection of scalp electrodes in BCI applications. PMID:19964437

  4. Robust high temperature oxygen sensor electrodes

    DEFF Research Database (Denmark)

    Lund, Anders

    conducting gadolinium-doped cerium oxide (CGO). The addition of CGO was found to decrease the polarisation resistance of the oxygen reaction by up to an order of magnitude compared with a single phase platinum electrode by increasing the effective triple phase boundary (TPB) length. It did not have any......Platinum is the most widely used material in high temperature oxygen sensor electrodes. However, platinum is expensive and the platinum electrode may, under certain conditions, suffer from poisoning, which is detrimental for an oxygen sensor. The objective of this thesis is to evaluate electrode...... materials as candidates for robust oxygen sensor electrodes. The present work focuses on characterising the electrochemical properties of a few electrode materials to understand which oxygen electrode processes are limiting for the response time of the sensor electrode. Three types of porous platinum...

  5. A method for making a hydrogen electrode

    Energy Technology Data Exchange (ETDEWEB)

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

    1983-09-08

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

  6. Novel Duplicate Address Detection with Hash Function.

    Science.gov (United States)

    Song, GuangJia; Ji, ZhenZhou

    2016-01-01

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

  7. Novel Duplicate Address Detection with Hash Function.

    Science.gov (United States)

    Song, GuangJia; Ji, ZhenZhou

    2016-01-01

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

  8. Electrochemical behaviour of benzene on platinum electrodes

    OpenAIRE

    Montilla Jiménez, Francisco; Huerta Arráez, Francisco; Morallón Núñez, Emilia; Vázquez Picó, José Luis

    1999-01-01

    The adsorption and oxidation of benzene in acidic media on platinum electrodes (polycrystalline and single-crystal electrodes) have been studied by cyclic voltammetry and in-situ Fourier transform infrared spectroscopy. The oxidation characteristics of benzene depend on the surface structure of the platinum electrode used. In all platinum electrodes studied, the main reduction product of benzene is cyclohexane, and the oxidation products detected by infrared spectroscopy have been CO2 and ben...

  9. Voltammetry at porous electrodes: A theoretical study

    OpenAIRE

    Barnes, Edward O; Chena, Xiaojun; Li, Peilin; Compton, Richard G.

    2014-01-01

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

  10. Inexpensive and Disposable pH Electrodes

    Science.gov (United States)

    Goldcamp, Michael J.; Conklin, Alfred; Nelson, Kimberly; Marchetti, Jessica; Brashear, Ryan; Epure, Emily

    2010-01-01

    Inexpensive electrodes for the measurement of pH have been constructed using the ionophore tribenzylamine for sensing H[superscript +] concentrations. Both traditional liquid-membrane electrodes and coated-wire electrodes have been constructed and studied, and both exhibit linear, nearly Nernstian responses to changes in pH. Measurements of pH…

  11. 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.

  12. Fluctuations at electrode-YSZ interfaces

    DEFF Research Database (Denmark)

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

    2005-01-01

    . At temperatures below 900$^\\circ$C the fluctuations cease. At LSM oxygen electrodes and Ni hydrogen electrodes the fluctuations are similar in amplitude and frequency, but the characteristic shape is not observed. Also some spectacular, but not easily reproduced, observations on Ni electrodes in hydrogen/water...

  13. 21 CFR 882.1310 - Cortical electrode.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cortical electrode. 882.1310 Section 882.1310 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL...) Identification. A cortical electrode is an electrode which is temporarily placed on the surface of the brain...

  14. 21 CFR 890.1175 - Electrode cable.

    Science.gov (United States)

    2010-04-01

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

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

    Science.gov (United States)

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

    2006-01-01

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

  16. An Experimental of IPv6 Address Assignment for Global Unicast Address Using NS-3

    Directory of Open Access Journals (Sweden)

    Dr. P. Sumathi

    2015-11-01

    Full Text Available Internet Protocol Version 6 (IPv6 is the next generation protocol and in the near future, routers are going to become more faster and new technologies are going to reduce the Internet delay. IPv6 global unicast address is similar to IPv4 public address and globally routable. This Global unicast address assignment process provides new function called Stateless Address Auto Configuration (SLAAC is a significant feature for host itself generating and configuring own addresses to enable communication. In this paper aims to describe experimental about IPv6 address assignment for global unicast address and evaluation of a host using various parameters such as Default router IP address, Throughput, Average End to End Delay and Domain Name Server (DNS IP address. The study was carried out using an open source Network Simulator (NS-3 to study and analyses the behavior of IPv6 address assignment.

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

    Science.gov (United States)

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

    2007-01-01

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

  18. 7 CFR 1730.3 - RUS addresses.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 11 2010-01-01 2010-01-01 false RUS addresses. 1730.3 Section 1730.3 Agriculture... ELECTRIC SYSTEM OPERATIONS AND MAINTENANCE General § 1730.3 RUS addresses. (a) Persons wishing to obtain...) Documents required to be submitted to RUS under this part are to be sent to the office of the...

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

    Science.gov (United States)

    Palmer, Fred M.

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

  20. A Novel Approach for TNA Address Management

    Institute of Scientific and Technical Information of China (English)

    Xiaodong Wang; Yaohui Jin; Weishen Hu; Shenli Zhu

    2003-01-01

    We present a new scheme to allocate/de- allocate Transport Network Assigned (TNA) address using Link ManagementProtocol (LMP) and to register/resolution these addresses using Lightweight Directory Access Protocol (LDAP) forAutomatically Switched Optical Network (ASON).

  1. Approaches for Resolving Dynamic IP Addressing.

    Science.gov (United States)

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

    1997-01-01

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

  2. Image compression using address-vector quantization

    Science.gov (United States)

    Nasrabadi, Nasser M.; Feng, Yushu

    1990-12-01

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

  3. Two-and three-electrode impedance spectroscopic studies of graphite electrode in the first lithiation

    Institute of Scientific and Technical Information of China (English)

    ZHUANG QuanChao; TIAN LeiLei; WEI GuoZhen; DONG QuanFeng; SUN ShiGang

    2009-01-01

    The first lithiation of graphite electrode was investigated by electrochemical impedance spectroscopy (EIS) and scanning electron microscope (SEM) in a two-electrode button cell and a three-electrode glass cell.The results demonstrate that the study of the variation of EIS feature of the graphite electrode in the two-electrode button cell with electrode polarization potential decreasing in the first lithiation cannot be used to investigate the formation mechanism of the solid electrolyte interphase (SEI) film.However,the formation and growth process of the SEI film can be acquired by investigating the variation of EIS features of the graphite electrode in the three-electrode glass cell with the decrease of electrode polarization potential in the first lithiation.Moreover,the results also point out that the SEI film on graphite electrode is mainly formed between 1.0 and 0.6 V in the first lithiation.

  4. An Experimental of IPv6 Address Assignment for Global Unicast Address Using NS-3

    OpenAIRE

    DR.P.SUMATHI; Dr. Saroj Patel; Prabhakaran,, Dorairaj

    2015-01-01

    Internet Protocol Version 6 (IPv6) is the next generation protocol and in the near future, routers are going to become more faster and new technologies are going to reduce the Internet delay. IPv6 global unicast address is similar to IPv4 public address and globally routable. This Global unicast address assignment process provides new function called Stateless Address Auto Configuration (SLAAC) is a significant feature for host itself generating and configuring own addresses to enable communi...

  5. Data structure, method and system for address lookup

    OpenAIRE

    Stefanakis, G.; Sourdis, I.; Nedeltchev, G.G.; De Smet, R.

    2010-01-01

    Method and computer system for constructing a decision tree for use in address lookup of a requested address in an address space. The address space is arranged as a set of basic address ranges. Each basic address range is defined by a lower and an upper bound address, and an address in the address space is represented by a predetermined number of bits.

  6. Performance of conducting polymer electrodes for stimulating neuroprosthetics

    Science.gov (United States)

    Green, R. A.; Matteucci, P. B.; Hassarati, R. T.; Giraud, B.; Dodds, C. W. D.; Chen, S.; Byrnes-Preston, P. J.; Suaning, G. J.; Poole-Warren, L. A.; Lovell, N. H.

    2013-02-01

    Objective. Recent interest in the use of conducting polymers (CPs) for neural stimulation electrodes has been growing; however, concerns remain regarding the stability of coatings under stimulation conditions. These studies examine the factors of the CP and implant environment that affect coating stability. The CP poly(ethylene dioxythiophene) (PEDOT) is examined in comparison to platinum (Pt), to demonstrate the potential performance of these coatings in neuroprosthetic applications. Approach. PEDOT is coated on Pt microelectrode arrays and assessed in vitro for charge injection limit and long-term stability under stimulation in biologically relevant electrolytes. Physical and electrical stability of coatings following ethylene oxide (ETO) sterilization is established and efficacy of PEDOT as a visual prosthesis bioelectrode is assessed in the feline model. Main results. It was demonstrated that PEDOT reduced the potential excursion at a Pt electrode interface by 72% in biologically relevant solutions. The charge injection limit of PEDOT for material stability was found to be on average 30× larger than Pt when tested in physiological saline and 20× larger than Pt when tested in protein supplemented media. Additionally stability of the coating was confirmed electrically and morphologically following ETO processing. It was demonstrated that PEDOT-coated electrodes had lower potential excursions in vivo and electrically evoked potentials (EEPs) could be detected within the visual cortex. Significance. These studies demonstrate that PEDOT can be produced as a stable electrode coating which can be sterilized and perform effectively and safely in neuroprosthetic applications. Furthermore these findings address the necessity for characterizing in vitro properties of electrodes in biologically relevant milieu which mimic the in vivo environment more closely.

  7. Development of a lightweight nickel electrode

    Science.gov (United States)

    Britton, D. L.; Reid, M. A.

    1984-01-01

    Nickel electrodes made using lightweight plastic plaque are about half the weight of electrodes made from state of the art sintered nickel plaque. This weight reduction would result in a significant improvement in the energy density of batteries using nickel electrodes (nickel hydrogen, nickel cadmium and nickel zinc). These lightweight electrodes are suitably conductive and yield comparable capacities (as high as 0.25 AH/gm (0.048 AH/sq cm)) after formation. These lightweight electrodes also show excellent discharge performance at high rates.

  8. Long life lithium batteries with stabilized electrodes

    Science.gov (United States)

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

    2009-03-24

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

  9. Method for manufacturing magnetohydrodynamic electrodes

    Science.gov (United States)

    Killpatrick, Don H.; Thresh, Henry R.

    1982-01-01

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

  10. Flexible multi-electrode array with integrated bendable CMOS-chip for implantable systems.

    Science.gov (United States)

    Winkin, N; Mokwa, W

    2012-01-01

    Micro-electrodes and micro-electrode arrays (MEAs) for stimulating neurons or recording action potentials are widely used in medical applications or biological research. For medical implants in many applications like brain implants or retinal implants there is a need for flexible MEAs with a large area and a large number of stimulation electrodes. In this work a flexible MEA with an embedded flexible silicon dummy CMOS-chip facing these challenges has been designed, manufactured and characterized. This approach offers the possibility by connecting and addressing several of these MEAs via a bus system, to increase the number and the density of electrodes significantly. This paper describes the design and fabrication process. Results on the mechanical and electrical behavior will be given and possible improvements for medical applications by this novel approach will be discussed.

  11. Laboratory experiments on current flow between stationary and moving electrodes in magnetoplasmas

    Science.gov (United States)

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

    1990-01-01

    Laboratory experiments were performed in order to investigate the basic physics of current flow between tethered electrodes in magnetoplasmas. The major findings are summarized. The experiments are performed in an effectively very large laboratory plasma in which not only the nonlinear current collection is addressed but also the propagation and spread of currents, the formation of current wings by moving electrodes, the current closure, and radiation from transmission lines. The laboratory plasma consists of a pulsed dc discharge whose Maxwellian afterglow provides a quiescent, current-free uniform background plasma. Electrodes consisting of collectors and electron emitters are inserted into the plasma and a pulsed voltage is applied between two floating electrodes via insulated transmission lines. Besides the applied current in the wire, the total current density in the plasma is obtained from space and time resolved magnetic probe measurements via Maxwell's law. Langmuir probes yield the plasma parameters.

  12. Nano-machining of biosensor electrodes through gold nanoparticles deposition produced by femtosecond laser ablation

    Science.gov (United States)

    Della Ventura, B.; Funari, R.; Anoop, K. K.; Amoruso, S.; Ausanio, G.; Gesuele, F.; Velotta, R.; Altucci, C.

    2015-06-01

    We report an application of femtosecond laser ablation to improve the sensitivity of biosensors based on a quartz crystal microbalance device. The nanoparticles produced by irradiating a gold target with 527-nm, 300-fs laser pulses, in high vacuum, are directly deposited on the quartz crystal microbalance electrode. Different gold electrodes are fabricated by varying the deposition time, thus addressing how the nanoparticles surface coverage influences the sensor response. The modified biosensor is tested by weighting immobilized IgG antibody from goat and its analyte (IgG from mouse), and the results are compared with a standard electrode. A substantial increase of biosensor sensitivity is achieved, thus demonstrating that femtosecond laser ablation and deposition is a viable physical method to improve the biosensor sensitivity by means of nanostructured electrodes.

  13. A dry electrode for EEG recording.

    Science.gov (United States)

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

    1994-05-01

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

  14. Address forms in Chinese audit opinions

    Institute of Scientific and Technical Information of China (English)

    Ziye; Zhao

    2014-01-01

    Although forms of address are widely used in textual and other types of disclosure,empirical evidence of their effects is rare.China provides a unique setting in which to test the economic consequences of the forms of address used in audit reports.From 2003 to 2011,about 60%of auditors surveyed addressed their clients by their real names in audit opinions,while the others used honorifics.Based on a sample of Chinese audit opinions,I report the following findings.First,the announcement of an audit opinion that uses the client’s real name elicits a greater market response than the announcement of an opinion featuring an honorific form of address.Second,the effects of real-name forms of address are stronger in firms with weak board governance.Third,the association between audit fees and audit risk factors,such as loss-making,is stronger in firms that are addressed by their real names in audit reports.I conclude from these findings that the forms of address used in audit opinions may reveal private information on audit quality.The results of this study are consistent with the power-solidarity effect described by sociolinguists.

  15. Snap-in compressible biomedical electrode

    Science.gov (United States)

    Frost, J. D., Jr.; Hillman, C. E., Jr. (Inventor)

    1977-01-01

    A replaceable, prefilled electrode enclosed in a plastic seal and suitably adapted for attachment to a reusable, washable cap having snaps thereon is disclosed. The apparatus is particularly adapted for quick positioning of electrodes to obtain an EEG. The individual electrodes are formed of a sponge body which is filled with a conductive electrolyte gel during manufacture. The sponge body is adjacent to a base formed of a conductive plastic material. The base has at its center a male gripper snap. The cap locates the female snap to enable the electrode to be positioned. The electrode can be stored and used quickly by attaching to the female gripper snap. The snap is correctly positioned and located by mounting it in a stretchable cap. The cap is reusable with new electrodes for each use. The electrolyte gel serves as the contact electrode to achieve a good ohmic contact with the scalp.

  16. Redox electrode materials for supercapatteries

    Science.gov (United States)

    Yu, Linpo; Chen, George Z.

    2016-09-01

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

  17. Stretchable Micro-Electrode Array

    Energy Technology Data Exchange (ETDEWEB)

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

    2002-03-08

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

  18. Surface modification of recording electrodes

    Directory of Open Access Journals (Sweden)

    Iaci Miranda Pereira

    2013-01-01

    Full Text Available Waterborne Polyurethanes (PUs are a family of polymers that contains urethane linkages synthesized in an aqueous environment and are thus free of organic solvents. Recently, waterborne PUs have been extensively studied for biomedical applications because of their biocompatibility. The present work investigates the following: (1 the impact on electrical performance of electrode materials (platinum and silicon modified chemically by a layer of waterborne PU, and (2 the behavior of rat cardiac fibroblasts and rat cardiomyocytes when in contact with an electrode surface. Diisocyanate and poly(caprolactone diol were the main reagents for producing PUs. The electrochemical impedance of the electrode/electrolyte interface was accessed by electrochemical impedance spectroscopy. The cellular viability, proliferation, and morphology changes were investigated using an MTT assay. Cardiomyocyte adherence was observed by scanning electron microscopy. The obtained surface was uniform, flat, and transparent. The film showed good adhesion, and no peeling was detected. The electrochemical impedance decreased over time and was influenced by the ionic permeability of the PU layer. The five samples did not show cytotoxicity when in contact with neonatal rat cells.

  19. Electrical properties of metallic electrodes.

    Science.gov (United States)

    Ragheb, T; Geddes, L A

    1990-03-01

    The series equivalent resistance R and capacitance C of metal/saline electrode/electrolyte interfaces were measured as a function of frequency (100 Hz-20k Hz) and current density (0.25 to 1000 A m-2) for eight typical electrode metals. For each of the metals tested, R decreased and C increased as the current density was increased above a critical value (with the exception of silver and MP35N at frequencies above 1 kHz for which R increased and C decreased slightly). With the exception of copper, the current density linearity limit (for 10 per cent decrease in R or 10 per cent increase in C) increased with increasing frequency and, in most cases, the current density linearity limit for 10 per cent increase in C was slightly less than that for 10 per cent decrease in R. Among the metals tested, copper and aluminium had the lowest current carrying capability and rhodium had the highest current-carrying capability. The current carrying capabilities of 316 SS, platinum, silver and MP35N, were intermediate and similar. With increasing current density, an increase in the electrode/electrolyte capacitance was the most sensitive indicator of the current-carrying linearity limit. PMID:2376994

  20. Local address and emergency contact details

    CERN Multimedia

    2013-01-01

    The HR Department would like to remind members of the personnel that they are responsible for ensuring that their personal data concerning local address and preferred emergency contact details remains valid and up-to-date.   Both are easily accessible via the links below: Local address: https://edh.cern.ch/Document/Personnel/LocalAddressChange   Emergency contacts: https://edh.cern.ch/Document/Personnel/EC   Please take a few minutes to check your details and modify if necessary. Thank you in advance. HR Department Head Office

  1. Addressing Transition Issues in Languages Education.

    Science.gov (United States)

    Steigler-Peters, Susi; Moran, Wendy; Piccioli, Maria Teresa; Chesterton, Paul

    2003-01-01

    Focuses on what has been learned from the implementation and evaluation of the Australian Language and Continuity Initiative (LCI) in relation to addressing transition issues in language education. (Author/VWL)

  2. Radiation and occupational health: opening address

    International Nuclear Information System (INIS)

    The part of address discusses the following issue: benefits of radiological protection in Malaysia, traceability and accountability as assurance of the validity of radiation measurement, Laboratory Accreditation Scheme, Atomic Energy Licensing Act

  3. Address Points, Published in unknown, SWGRC.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Address Points dataset as of unknown. Data by this publisher are often provided in Geographic coordinate system; in a Not Sure projection; The extent of these...

  4. An Efficient Reconfigurable Content Addressable Memory

    Directory of Open Access Journals (Sweden)

    Saswathy Sekharan

    2014-01-01

    Full Text Available This paper introduces an efficient reconfigurable Content Addressable memory (CAMs which is a hardware search engine that are much faster than other algorithmic approaches for search intensive applications. Content Addressable Memories are composed of conventional semiconductor memory (usually SRAM with added comparison circuitry that enables a search operation to complete in a single clock cycle. To understand more about Content Addressable Memory, it helps to contrast it with RAM. A RAM is an integrated circuit that stores data temporarily. In CAM, the user supplies the data and gets back the address.In this paper we introduce a temporary memory called Cache. The cache-CAM (C-CAM saves 80% power over a conventional CAM. Compared with existing software search engines proposed hardware search engine can do multiple searches at a time with more flexibility.

  5. Addressing Your Child's Weight at the Doctor

    Science.gov (United States)

    ... Beverage Toolkit Addressing your Child's Weight at the Doctor Updated:Aug 4,2014 The discussion of weight ... tips on how to make talking with your doctor about weight and childhood obesity less daunting: Come ...

  6. Census Bureau Planned Acquisition: Address Data

    Data.gov (United States)

    US Census Bureau, Department of Commerce — The Census Bureau updates and maintains address data to support the correct allocation of population and housing for censuses and surveys. Boundaries, streets,...

  7. Measuring the Density Matrix by Local Addressing

    CERN Document Server

    Kis, Z

    2001-01-01

    We introduce a procedure to measure the density matrix of a material system. The density matrix is addressed locally in this scheme by applying a sequence of delayed light pulses. The procedure is based on the stimulated Raman adiabatic passage (STIRAP) technique. It is shown that a series of population measurements on the target state of the population transfer process yields unambiguous information about the populations and coherences of the addressed states, which therefore can be determined.

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

    Science.gov (United States)

    Yin, Hang; Pardue, Machelle T

    2004-01-01

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

  9. Address Points, address, Published in 2008, 1:24000 (1in=2000ft) scale, Juab County.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Address Points dataset, published at 1:24000 (1in=2000ft) scale, was produced all or in part from Other information as of 2008. It is described as 'address'....

  10. Parcels and Land Ownership, rural addressing does collect address points, Published in unknown, Gibson County Government.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Parcels and Land Ownership dataset as of unknown. It is described as 'rural addressing does collect address points'. The extent of these data is generally Gila...

  11. 46 CFR 67.113 - Managing owner designation; address; requirement to report change of address.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Managing owner designation; address; requirement to... Required for Vessel Documentation § 67.113 Managing owner designation; address; requirement to report change of address. The owner of each vessel must designate a managing owner on the Application...

  12. Time to address the problems at the neural interface

    Science.gov (United States)

    Durand, Dominique M.; Ghovanloo, Maysam; Krames, Elliot

    2014-04-01

    Neural engineers have made significant, if not remarkable, progress in interfacing with the nervous system in the last ten years. In particular, neuromodulation of the brain has generated significant therapeutic benefits [1-5]. EEG electrodes can be used to communicate with patients with locked-in syndrome [6]. In the central nervous system (CNS), electrode arrays placed directly over or within the cortex can record neural signals related to the intent of the subject or patient [7, 8]. A similar technology has allowed paralyzed patients to control an otherwise normal skeletal system with brain signals [9, 10]. This technology has significant potential to restore function in these and other patients with neural disorders such as stroke [11]. Although there are several multichannel arrays described in the literature, the workhorse for these cortical interfaces has been the Utah array [12]. This 100-channel electrode array has been used in most studies on animals and humans since the 1990s and is commercially available. This array and other similar microelectrode arrays can record neural signals with high quality (high signal-to-noise ratio), but these signals fade and disappear after a few months and therefore the current technology is not reliable for extended periods of time. Therefore, despite these major advances in communicating with the brain, clinical translation cannot be implemented. The reasons for this failure are not known but clearly involve the interface between the electrode and the neural tissue. The Defense Advanced Research Project Agency (DARPA) as well as other federal funding agencies such as the National Science Foundation (NSF) and the National Institutes of Health have provided significant financial support to investigate this problem without much success. A recent funding program from DARPA was designed to establish the failure modes in order to generate a reliable neural interface technology and again was unsuccessful at producing a robust

  13. 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.

  14. 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.

  15. Addressing Colloidal Stability for Unambiguous Electroanalysis of Single Nanoparticle Impacts.

    Science.gov (United States)

    Robinson, Donald A; Kondajji, Aditya M; Castañeda, Alma D; Dasari, Radhika; Crooks, Richard M; Stevenson, Keith J

    2016-07-01

    Herein the problem of colloidal instability on electrochemically detected nanoparticle (NP) collisions with a Hg ultramicroelectrode (UME) by electrocatalytic amplification is addressed. NP tracking analysis (NTA) shows that rapid aggregation occurs in solution after diluting citrate-stabilized Pt NPs with hydrazine/phosphate buffers of net ionic strength greater than 70 mM. Colloidal stability improves by lowering the ionic strength, indicating that aggregation processes were strongly affected by charge screening of the NP double layer interactions at high cation concentrations. For the system of lowest ionic strength, the overwhelming majority of observed electrocatalytic current signals represent single NP/electrode impacts, as confirmed by NTA kinetic monitoring. NP diffusion coefficients determined by NTA and NP impact electroanalysis are in excellent agreement for the stable colloids, which signifies that the sticking probability of Pt NPs interacting with Hg is unity and that the observed NP impact rate agrees with the expected steady-state diffusive flux expression for the spherical cap Hg UME.

  16. 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.

  17. Lithium-aluminum-magnesium electrode composition

    Science.gov (United States)

    Melendres, Carlos A.; Siegel, Stanley

    1978-01-01

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

  18. A method to locate electrode placement.

    Science.gov (United States)

    Brodnick, D

    2000-01-01

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

  19. Advances in lightweight nickel electrode technology

    Science.gov (United States)

    Coates, Dwaine; Paul, Gary; Daugherty, Paul

    1989-01-01

    Studies are currently underway to further the development of lightweight nickel electrode technology. Work is focused primarily on the space nickel-hydrogen system and nickel-iron system but is also applicable to the nickel-cadmium and nickel-zinc systems. The goal is to reduce electrode weight while maintaining or improving performance, thereby increasing electrode energy density. Two basic electrode structures are being investigated. The first is the traditional nickel sponge produced from sintered nickel-carbonyl powder. The second is a new material for this application which consists of a non-woven mat of nickel fiber. Electrodes are being manufactured, tested, and evaluated at the electrode and cell level.

  20. Secondary Ionization Coefficient of Dielectric Electrode

    Science.gov (United States)

    Kashiwagi, Yasuhide; Suzuki, Susumu; Itoh, Haruo

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

  1. Electrochromism: basis and application of nanomaterials in development of high performance electrodes; Eletrocromismo: fundamentos e a aplicacao de nanomateriais no desenvolvimento de eletrodos de alto desempenho

    Energy Technology Data Exchange (ETDEWEB)

    Quintanilha, Ronaldo C.; Rocha, Igor; Vichessi, Raquel B.; Lucht, Emili; Naidek, Karine; Winnischofer, Herbert; Vidotti, Marcio, E-mail: mvidotti@ufpr.br [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Departamento de Quimica

    2014-07-01

    This review deals with the basis and novel trends in electrochromism, describing the basic aspects and methodologies employed for the construction and analyses of different modified electrodes. The work presents the classic materials used for the construction of electrochromic electrodes, such as WO{sub 3} and a view on the basic concepts of chromaticity as a useful approach for analyzing colorimetric results. The report also addresses how the incorporation of nanomaterials and the consequent novel modification of electrodes have furthered this area of science, producing electrochromic electrodes with high performance, high efficiency and low response times. (author)

  2. Electrocatalytic activity of bismuth doped silver electrodes

    CERN Document Server

    Amjad, M

    2002-01-01

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

  3. Esophageal ECG: The challenge of electrode design

    OpenAIRE

    Niederhauser, Thomas; Häberlin, Andreas; Vogel, R; Marisa, Thanks; Götte, Josef; Jacomet, Marcel

    2011-01-01

    Two commercially available electrode catheters are examined for their suitability in esophageal long-term ECG recordings. Both, electrical sensing characteristics as well as clinical acceptance were investigated in a clinical study including inpatients with cardiovascular diseases. In total, 31 esophageal ECG were obtained in 36 patients. Results showed that esophageal electrodes were well tolerated by the patients. Hemispherical electrodes with higher diameter required more insertion attempt...

  4. Semiconductor devices having a recessed electrode structure

    Science.gov (United States)

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

    2015-05-26

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

  5. Semiconductor electrode with improved photostability characteristics

    Science.gov (United States)

    Frank, Arthur J.

    1987-01-01

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

  6. Strategies for Addressing Spreadsheet Compliance Challenges

    CERN Document Server

    Weber, Brandon

    2006-01-01

    Most organizations today use spreadsheets in some form or another to support critical business processes. However the financial resources, and developmental rigor dedicated to them are often minor in comparison to other enterprise technology. The increasing focus on achieving regulatory and other forms of compliance over key technology assets has made it clear that organizations must regard spreadsheets as an enterprise resource and account for them when developing an overall compliance strategy. This paper provides the reader with a set of practical strategies for addressing spreadsheet compliance from an organizational perspective. It then presents capabilities offered in the 2007 Microsoft Office System which can be used to help customers address compliance challenges.

  7. Addressing techniques of liquid crystal displays

    CERN Document Server

    Ruckmongathan, Temkar N

    2014-01-01

    Unique reference source that can be used from the beginning to end of a design project to aid choosing an appropriate LCD addressing technique for a given application This book will be aimed at design engineers who are likely to embed LCD drivers and controllers in many systems including systems on chip. Such designers face the challenge of making the right choice of an addressing technique that will serve them with best performance at minimal cost and complexity. Readers will be able to learn about various methods available for driving matrix LCDs and the comparisons at the end of each chap

  8. Welfare work addressing immigrants and refugees

    DEFF Research Database (Denmark)

    Øland, Trine

    In this presentation I will discuss the ways in which welfare workers addressing immigrants and refugees (re)produce integrationist visions, symbolizing society as an integrated whole and immigrants/refugees as a distraction to that whole. Paradoxically, welfare workers also oppose...... these integrationist visions in their quest to protect immigrants’ and refugees’ fundamental wellbeing and status as human beings with equal rights, group life and history. These opposing elements generate ambiguity and contradiction within integrationist welfare work. The ambition of the presentation is to enquire......, nurses and more) addressing immigrants and refugees and their families and descendants in the Danish welfare nation-state....

  9. Carbon aerogel electrodes for direct energy conversion

    Science.gov (United States)

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

    1997-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-07-01

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

  11. Electrodes For Alkali-Metal Thermoelectric Converters

    Science.gov (United States)

    Williams, Roger M.; Wheeler, Bob L.; Jeffries-Nakamura, Barbara; Lamb, James L.; Bankston, C. Perry; Cole, Terry

    1989-01-01

    Combination of thin, porous electrode and overlying collector grid reduces internal resistance of alkali-metal thermoelectric converter cell. Low resistance of new electrode and grid boosts power density nearly to 1 W/cm2 of electrode area at typical operating temperatures of 1,000 to 1,300 K. Conductive grid encircles electrode film on alumina tube. Bus wire runs along tube to collect electrical current from grid. Such converters used to transform solar, nuclear, and waste heat into electric power.

  12. Electrode design for electrohydrodynamic conduction pumping

    Science.gov (United States)

    Yagoobi, Jamal Seyed (Inventor)

    2007-01-01

    An electrohydrodynamic conduction liquid pumping system includes a vessel configured to contain a liquid or a liquid/vapor therein. This vessel can be of a elongate conduit configuration, an elongate channel configuration or a liquid enclosure configuration. At least a single pair of electrodes are disposed in a spaced apart relation to each other on the vessel and configured to be oriented in the liquid. A power supply is coupled to the electrodes and operable to generate electric fields in between the pair of electrodes, the electric forces inducing a net liquid movement relative to the vessel. Various electrode designs are embraced within the concept of this invention.

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

    Science.gov (United States)

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

    2013-09-17

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

  14. Elegant design of electrode and electrode/electrolyte interface in lithium-ion batteries by atomic layer deposition

    International Nuclear Information System (INIS)

    Lithium-ion batteries (LIBs) are very promising power supply systems for a variety of applications, such as electric vehicles, plug-in hybrid electric vehicles, grid energy storage, and microelectronics. However, to realize these practical applications, many challenges need to be addressed in LIBs, such as power and energy density, cycling lifetime, safety, and cost. Atomic layer deposition (ALD) is emerging as a powerful technique for solving these problems due to its exclusive advantages over other film deposition counterparts. In this review, we summarize the state-of-the-art progresses of employing ALD to design novel nanostructured electrode materials and solid-state electrolytes and to tailor electrode/electrolyte interface by surface coatings in order to prevent unfavorable side reactions and achieve optimal performance of the electrode. Insights into the future research and development of the ALD technique for LIB applications are also discussed. We expect that this review article will provide resourceful information to researchers in both fields of LIBs and ALD and also will stimulate more insightful studies of using ALD for the development of next-generation LIBs. (review)

  15. Polystyrene Based Silver Selective Electrodes

    Directory of Open Access Journals (Sweden)

    Shiva Agarwal

    2002-06-01

    Full Text Available Silver(I selective sensors have been fabricated from polystyrene matrix membranes containing macrocycle, Me6(14 diene.2HClO4 as ionophore. Best performance was exhibited by the membrane having a composition macrocycle : Polystyrene in the ratio 15:1. This membrane worked well over a wide concentration range 5.0×10-6–1.0×10-1M of Ag+ with a near-Nernstian slope of 53.0 ± 1.0 mV per decade of Ag+ activity. The response time of the sensor is <15 s and the membrane can be used over a period of four months with good reproducibility. The proposed electrode works well in a wide pH range 2.5-9.0 and demonstrates good discriminating power over a number of mono-, di-, and trivalent cations. The sensor has also been used as an indicator electrode in the potentiometric titration of silver(II ions against NaCl solution. The sensor can also be used in non-aqueous medium with no significant change in the value of slope or working concentration range for the estimation of Ag+ in solution having up to 25% (v/v nonaqueous fraction.

  16. Taxel-addressable matrix of vertical nanowire piezotronic transistors

    Science.gov (United States)

    Wang, Zhong Lin; Wu, Wenzhuo; Wen, Xiaonan

    2015-05-05

    A tactile sensing matrix includes a substrate, a first plurality of elongated electrode structures, a plurality of vertically aligned piezoelectric members, an insulating layer infused into the piezoelectric members and a second plurality of elongated electrode structures. The first plurality of elongated electrode structures is disposed on the substrate along a first orientation. The vertically aligned piezoelectric members is disposed on the first plurality of elongated electrode structures and form a matrix having columns of piezoelectric members disposed along the first orientation and rows of piezoelectric members disposed along a second orientation that is transverse to the first orientation. The second plurality of elongated electrode structures is disposed on the insulating layer along the second orientation. The elongated electrode structures form a Schottky contact with the piezoelectric members. When pressure is applied to the piezoelectric members, current flow therethrough is modulated.

  17. [Re-evaluation of using acupuncture needle as sphenoidal electrode in temporal lobe epilepsy].

    Science.gov (United States)

    Chu, Nai-Shin

    2009-06-01

    In 1965, Feng of the Peking Union Hospital published an article entitled "Innovation in electroencephalography: the use of acupuncture needles as sphenoidal electrodes". It was a preliminary report, but surprisingly EEG records in the figures did not show definite spikes or sharp waves in the sphenoidal leads. In 1983, Feng and his colleagues reported a summary of 2,000 cases studied with acupuncture needle sphenoidal electrodes. This time, spikes or sharp waves were shown in EEG recordings. However, cases studied were several "paroxysmal disorders", including psychomotor seizure (155 cases), generalized seizure (765 cases), epileptic cephalgia (101 cases), syncope (104 cases), abdominal epilepsy (24 cases), encephalopathy (135 cases), brain tumor (32 cases), hemiplegia of unknown cause (43 cases), psychosis (34 cases), and others (607 cases). Therefore, there were many unknown cases and many cases that were not related to temporal lobe epilepsy. Surprisingly, the increase in detection by acupuncture needle electrode was higher for hemiplegia of unknown cause, brain tumors, and encephalopathies than for the temporal lobe epilepsy. Furthermore, the issue of no insulation of the acupuncture needle was not addressed. Therefore, we began in 1988 to reinvestigate the usefulness of uninsulated acupuncture needles as sphenoidal electrodes. We also compared the efficacy of anterior temporal electrodes (T1, T2) with those of acupuncture needle and EMG needle. Our results showed that when compared to the routine EEG recordings, acupuncture needle sphenoidal electrodes increased the yield of detecting anterior temporal spikes from 41% to 70%. Our data further showed that when compared to the EMG needle recordings, acupuncture needle recordings had the same detection rate, but the spike amplitude was slightly smaller (129 microv vs. 135 microv). Interestingly, we also found that anterior temporal surface electrode recordings were nearly as good as those of acupuncture needle

  18. 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.

  19. Adverse effects of near current-electrode placement in non-invasive bio-impedance measurements

    International Nuclear Information System (INIS)

    A major problem confronting application of impedance techniques to studies of disease is the extraction of intrinsic properties of the tissue from the measured impedances, which unavoidably involve geometric factors as well. Amongst the foremost are the sizes and locations of the measuring electrode arrays, and this paper addresses one of these, the location of current injecting electrodes. Tetrapolar impedance measurements on a 17.5 cm segment of the thigh gave R and X values three to four times larger when the current injecting electrodes were placed 2.5 cm from the sensing electrodes than when very distant placement was used. The frequency dependences of R and X were affected as well, though the X versus R plots still showed virtually perfect depressed-center semicircles, as in the Cole model. R(f) and X(f) for the set of contiguous 2.5 cm wide sub-segments show that these behaviors can be explained by a combination of the transverse orientation of current flow lines near the injecting electrodes and the anisotropy of the resistivity associated with the bundled fiber structure of muscle tissue. The measured impedance was found to be a separable function of geometric and intrinsic tissue variables, but far more complicated than is implicit in the usual cylindrical models. The results also suggest that many full and segmental body composition studies in the literature may be prone to substantial errors due to too close placement of the current injecting electrodes. (paper)

  20. Multi-electrode stimulation in somatosensory cortex increases probability of detection

    Science.gov (United States)

    Zaaimi, Boubker; Ruiz-Torres, Ricardo; Solla, Sara A.; Miller, Lee E.

    2013-10-01

    Objective. Brain machine interfaces (BMIs) that decode control signals from motor cortex have developed tremendously in the past decade, but virtually all rely exclusively on vision to provide feedback. There is now increasing interest in developing an afferent interface to replace natural somatosensation, much as the cochlear implant has done for the sense of hearing. Preliminary experiments toward a somatosensory neuroprosthesis have mostly addressed the sense of touch, but proprioception, the sense of limb position and movement, is also critical for the control of movement. However, proprioceptive areas of cortex lack the precise somatotopy of tactile areas. We showed previously that there is only a weak tendency for neighboring neurons in area 2 to signal similar directions of hand movement. Consequently, stimulation with the relatively large currents used in many studies is likely to activate a rather heterogeneous set of neurons. Approach. Here, we have compared the effect of single-electrode stimulation at subthreshold levels to the effect of stimulating as many as seven electrodes in combination. Main results. We found a mean enhancement in the sensitivity to the stimulus (d‧) of 0.17 for pairs compared to individual electrodes (an increase of roughly 30%), and an increase of 2.5 for groups of seven electrodes (260%). Significance. We propose that a proprioceptive interface made up of several hundred electrodes may yield safer, more effective sensation than a BMI using fewer electrodes and larger currents.

  1. Native Women at Risk: Addressing Cancer Prevention.

    Science.gov (United States)

    Thiemann, Kay M. B.

    1994-01-01

    Discusses outcomes of a conference that brought together representatives from Indian tribes, state health departments, the Indian Health Service, the Mayo Clinic, and the American Cancer Society, to address the high rate of cervical cancer among American Indian women. Describes barriers to health care and plans to promote cancer screening among…

  2. Road Map to Address Cognitive Health

    Centers for Disease Control (CDC) Podcasts

    2014-06-09

    In this podcast, CDC’s Dr. Lynda Anderson highlights the important roles that states and communities can play in addressing cognitive health as part of overall health.  Created: 6/9/2014 by National Center for Chronic Disease Prevention and Health Promotion (NCCDPHP).   Date Released: 6/9/2014.

  3. China-ROK Forum Addresses Monetary Issues

    Institute of Scientific and Technical Information of China (English)

    陈伟

    2008-01-01

    On June 12th,2008,the China-Korea Forum was held in Shanghai to address hot issues in China’s nancial sector such as banking reform,securities market and RMB appreciation,Vice Mayor of Shanghai,o cials from Shanghai Securities Exchange Research Center and the Korea Financial Service Commission were invited to share their wisdom on these issues.

  4. Addressing production stops in the food industry

    DEFF Research Database (Denmark)

    Hansen, Zaza Nadja Lee; Herbert, Luke Thomas; Jacobsen, Peter

    2014-01-01

    This paper investigates the challenges in the food industry which causes the production lines to stop, illustrated by a case study of an SME size company in the baked goods sector in Denmark. The paper proposes key elements this sector needs to be aware of to effectively address production stops...

  5. Addressing Student Debt in the Classroom

    Science.gov (United States)

    Perkins, David; Johnston, Tim; Lytle, Rick

    2016-01-01

    Student debt is a national concern. The authors address debt in the classroom to enhance students' understanding of the consequences of debt and the need for caution when financing their education. However, student feedback indicates this understanding has a delayed effect on borrowing behavior and underscores the importance of making difficult…

  6. Registering Names and Addresses for Information Technology.

    Science.gov (United States)

    Knapp, Arthur A.

    The identification of administrative authorities and the development of associated procedures for registering and accessing names and addresses of communications data systems are considered in this paper. It is noted that, for data communications systems using standards based on the Open Systems Interconnection (OSI) Reference Model specified by…

  7. Rational Rhymes for Addressing Common Childhood Issues

    Science.gov (United States)

    Warren, Jeffrey M.

    2011-01-01

    Music-based interventions are valuable tools counselors can use when working with children. Specific types of music-based interventions, such as songs or rhymes, can be especially pertinent in addressing the thoughts, feelings, and behaviors of children. Rational-emotive behavior therapy (REBT) provides a therapeutic framework that encourages…

  8. Problem Solvers: Solutions--The Inaugural Address

    Science.gov (United States)

    Dause, Emily

    2014-01-01

    Fourth graders in Miss Dause's and Mrs. Hicks's mathematics classes at South Mountain Elementary School in Dillsburg, Pennsylvania, worked with the data from the Inauagural Address problem that was previously published published in the February 2013 issue of "Teaching Children Mathematics". This activity allowed students to…

  9. IP Address Use in Internetworking Routing

    OpenAIRE

    2003-01-01

    tut quiz present anim This interactive tutorial covers the following: How routers use the elements of the IP address to forward packets of information., How information travels through the Internet.The interactions consists of pop-up definitions of terms, animations and self-check questions. EC3760 Introduction to Information Operations Engineering

  10. How Sociology Texts Address Gun Control

    Science.gov (United States)

    Tonso, William R.

    2004-01-01

    William R. Tonso has chosen an issue that he knows something about to examine how sociology textbooks address controversy. Appealing for gun control is fashionable, but it is at odds with a fondness that ordinary Americans have for their firearms--one that is supported by a growing body of research on deterrence to crime. There are two sides to…

  11. Addressing South Africa's Engineering Skills Gaps

    Science.gov (United States)

    Hall, Jonathan; Sandelands, Eric

    2009-01-01

    Purpose: This paper aims to provide a case study of how engineering skills gaps are being addressed by Murray & Roberts in South Africa. Design/methodology/approach: The paper focuses on skills challenges in South Africa from a reflective practitioner perspective, exploring a case example from an industry leader. Findings: The paper explores how…

  12. Dry Electrodes Facilitate Remote Health Monitoring

    Science.gov (United States)

    2013-01-01

    Johnson Space Center collaborated with Blacksburg, Virginia-based NanoSonic Inc. through the SBIR program to devise a sensor to replace the traditional electrodes used for an electrocardiogram in space. In 2011, NanoSonic started marketing the dry electrodes as well as an EKGear Sensor Shirt, which is being considered for use in hospital garments, athletic apparel, and dive suits.

  13. Means for limiting and ameliorating electrode shorting

    Energy Technology Data Exchange (ETDEWEB)

    Konynenburg, R.A. van; Farmer, J.C.

    1999-11-09

    A fuse and filter arrangement is described for limiting and ameliorating electrode shorting in capacitive deionization water purification systems utilizing carbon aerogel, for example. This arrangement limits and ameliorates the effects of conducting particles or debonded carbon aerogel in shorting the electrodes of a system such as a capacitive deionization water purification system. This is important because of the small interelectrode spacing and the finite possibility of debonding or fragmentation of carbon aerogel in a large system. The fuse and filter arrangement electrically protect the entire system from shutting down if a single pair of electrodes is shorted and mechanically prevents a conducting particle from migrating through the electrode stack, shorting a series of electrode pairs in sequence. It also limits the amount of energy released in a shorting event. The arrangement consists of a set of circuit breakers or fuses with one fuse or breaker in the power line connected to one electrode of each electrode pair and a set of screens of filters in the water flow channels between each set of electrode pairs.

  14. Means for limiting and ameliorating electrode shorting

    Energy Technology Data Exchange (ETDEWEB)

    Van Konynenburg, Richard A. (Livermore, CA); Farmer, Joseph C. (Tracy, CA)

    1999-01-01

    A fuse and filter arrangement for limiting and ameliorating electrode shorting in capacitive deionization water purification systems utilizing carbon aerogel, for example. This arrangement limits and ameliorates the effects of conducting particles or debonded carbon aerogel in shorting the electrodes of a system such as a capacitive deionization water purification system. This is important because of the small interelectrode spacing and the finite possibility of debonding or fragmentation of carbon aerogel in a large system. The fuse and filter arrangement electrically protect the entire system from shutting down if a single pair of electrodes is shorted and mechanically prevents a conducting particle from migrating through the electrode stack, shorting a series of electrode pairs in sequence. It also limits the amount of energy released in a shorting event. The arrangement consists of a set of circuit breakers or fuses with one fuse or breaker in the power line connected to one electrode of each electrode pair and a set of screens of filters in the water flow channels between each set of electrode pairs.

  15. The structure of hydrophobic gas diffusion electrodes.

    Science.gov (United States)

    Giner, J.

    1972-01-01

    The 'flooded agglomerate' model of the Teflon-bonded gas diffusion electrode is discussed. A mathematical treatment of the 'flooded agglomerate' model is given; it can be used to predict the performance of the electrode as a function of measurable physical parameters.

  16. Microneedle array electrode for human EEG recording

    NARCIS (Netherlands)

    Luttge, Regina; Bystrova, S.N.; Putten, van M.J.A.M; Vander Sloten, Jos; Verdonck, Pascal; Nyssen, Marc; Haueisen, Jens

    2009-01-01

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

  17. Platinum electrodes for electrochemical detection of bacteria

    Science.gov (United States)

    Wilkins, J. R.

    1979-01-01

    Bacteria is detected electro-chemically by measuring evolution of hydrogen in test system with platinum and reference electrode. Using system, electrodes of platinum are used to detect and enumerate varieties of gram-positive and gram-negative organisms compared in different media.

  18. New electrosurgical ball electrode with nonstick properties

    Science.gov (United States)

    Rondinone, Joseph; Brassell, James; Miller, Scott A., III; Thorne, Jonathan O.; Rondinone, David M.; Safabash, Jason; Vega, Felix

    1998-04-01

    A new electrosurgical ball electrode (SilverBulletTM) has been developed for applying radiofrequency (RF) energy to fuse biological and other materials to tissue surfaces. Specifically, the electrode was developed for use in conjunction with the Fusion Medical Technologies, Inc. gelatin patch (RapiSealTM) for use in pulmonary surgery to seal air leaks, and in solid abdominal organ surgeries to provide hemostatic tamponade. The new electrode allows for the application of RF energy in contact mode without the problems of the electrode sticking to the gelatin patch or the underlying tissue. Designed for use with commercially available electrosurgical handpieces, the electrode consists of a stainless steel connector that fits into the hand- piece, and an electrode assembly made from silver that includes a shank region, and a tip extension extending distally from the shank region. The distal tip of the tip extension is rounded and has a length of about 10 mm. The uniqueness of this electrode is the shank region which has a cross sectional area that is larger than the tip extension. The shank region acts as a heat sink to draw away heat from the tip extension while the tip extension itself remains sufficiently small to access desired target sites and display the desired energy transfer properties. In addition to the physical design, the use of silver as the core element provides a material with high electrical and thermal conductivities. The bulk of the electrode is appropriately insulated.

  19. The electrochemical impedance of metal hydride electrodes

    DEFF Research Database (Denmark)

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

    2002-01-01

    The electrochemical impedance responses for different laboratory type metal hydride electrodes were successfully modeled and fitted to experimental data for AB5 type hydrogen storage alloys as well as one MgNi type electrode. The models fitted the experimental data remarkably well. Several AC equ...

  20. Reverse electrodialysis : evaluation of suitable electrode systems

    NARCIS (Netherlands)

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

    2010-01-01

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

  1. Electrode Kinetics in High Temperature Fuel Cells

    DEFF Research Database (Denmark)

    Bay, Lasse

    1998-01-01

    The O_2 reduction on Pt electrode with an yttria stabilized zirconia (YSZ) electrolyte is examined with potential step, voltammetry and impedance measurements. Inductive hysteresis are observed in all cases, indicating an activation-deactivation process for the electrode reaction. The same is fou...

  2. Lithium metal oxide electrodes for lithium batteries

    Science.gov (United States)

    Thackeray, Michael M.; Kim, Jeom-Soo; Johnson, Christopher S.

    2008-01-01

    An uncycled electrode for a non-aqueous lithium electrochemical cell including a lithium metal oxide having the formula Li.sub.(2+2x)/(2+x)M'.sub.2x/(2+x)M.sub.(2-2x)/(2+x)O.sub.2-.delta., in which 0.ltoreq.xbatteries containing the electrodes.

  3. Electrochemical Behavior of SWCNT-TPLF Electrode Compared to SWCNT-coated GCE and GE Electrodes

    OpenAIRE

    Rahman, M. Muzibur; Jeon, Il C.

    2007-01-01

    Redox reaction [Fe(CN)6]3– / [Fe(CN)6]4– has been studied with a Single-Walled Carbon Nanotube (SWCNT)-coated Glassy Carbon Electrode (GCE), SWCNT-coated Gold Electrode (GE) and a lab-made SWCNT-TPLF (SWCNT-Thin-Paper-Like-Film) Electrode. The SWCNT-modified electrode has shown a well-defined redox peak compared to bare electrodes. Cyclic voltammetry was used in 50.0 × 10–3 M aqueous solution of KCl containing K4[Fe(CN)6] to obtain information on both the capacitive background ...

  4. electrode of an arbitrary shape

    Directory of Open Access Journals (Sweden)

    P. A. Krutitskii

    1999-01-01

    Full Text Available A problem on electric current in a semiconductor film from an electrode of an arbitrary shape is studied in the presence of a magnetic field. This situation describes the Hall effect, which indicates the deflection of electric, current from electric field in a semiconductor. From mathematical standpoint we consider the skew derivative problem for harmonic functions in the exterior of an open arc in a plane. By means of potential theory the problem is reduced to the Cauchy singular integral equation and next to the Fredholm equation of the 2nd kind which is uniquely solvable. The solution of the integral equation can be computed by standard codes by discretization and inversion of the matrix. The uniqueness and existence theorems are formulated.

  5. Surface characterization of platinum electrodes.

    Science.gov (United States)

    Solla-Gullón, José; Rodríguez, Paramaconi; Herrero, Enrique; Aldaz, Antonio; Feliu, Juan M

    2008-03-14

    The quantitative analysis of the different surface sites on platinum samples is attempted from pure voltammetric data. This analysis requires independent knowledge of the fraction of two-dimensional (111) and (100) domains. Specific site-probe reactions are employed to achieve this goal. Irreversibly-adsorbed bismuth and tellurium have been revealed to be sensitive to the presence of (111) terrace domains of different width whereas almost all sites involved in (100) ordered domains have been characterized through germanium adatoms. The experimental protocol follows that used with well-defined single-crystal electrodes and, therefore, requires careful control of the surface cleanliness. Platinum basal planes and their vicinal stepped surfaces have been employed to obtain calibration plots between the charge density measured under the adatom redox peak, specific for the type of surface site, and the corresponding terrace size. The evaluation of the (100) bidimensional domains can also be achieved using the voltammetric profiles, once the fraction of (111) ordered domains present in the polyoriented platinum has been determined and their featureless contribution has been subtracted from the whole voltammetric response. Using that curve, it is possible to perform a deconvolution of the adsorption states of the polycrystalline sample different from those related to (111) domains. The fraction of (100)-related states in the deconvoluted voltammogram can then be compared to that expected from the independent estimation coming from the charge involved in the redox process undergone by the irreversibly-adsorbed germanium and thus check the result of the deconvolution. The information about the surface-site distribution can also be applied to analyze the voltammetric profile of nanocrystalline platinum electrodes. PMID:18309392

  6. Improving student learning by addressing misconceptions

    Science.gov (United States)

    Engelmann, Carol A.; Huntoon, Jacqueline E.

    2011-12-01

    Students—and often those who teach them—come to class with preconceptions and misconceptions that hinder their learning. For instance, many K-12 students and teachers believe groundwater exists in the ground in actual rivers or lakes, but in fact, groundwater is found in permeable rock layers called aquifers. Such misconceptions need to be addressed before students can learn scientific concepts correctly. While other science disciplines have been addressing preconceptions and misconceptions for many years, the geoscience community has only recently begun to concentrate on the impact these have on students' learning. Valuable research is being done that illuminates how geologic thinking evolves from the "novice" to "expert" level. The expert is defined as an individual with deep understanding of Earth science concepts. As research progresses, geoscientists are realizing that correcting preconceptions and misconceptions can move teachers and students closer to the "expert" level [Libarkin, 2005].

  7. CANE: The Content Addressed Network Environment

    CERN Document Server

    Gardner-Stephen, Paul

    2007-01-01

    The fragmented nature and asymmetry of local and remote file access and network access, combined with the current lack of robust authenticity and privacy, hamstrings the current internet. The collection of disjoint and often ad-hoc technologies currently in use are at least partially responsible for the magnitude and potency of the plagues besetting the information economy, of which spam and email borne virii are canonical examples. The proposed replacement for the internet, Internet Protocol Version 6 (IPv6), does little to tackle these underlying issues, instead concentrating on addressing the technical issues of a decade ago. This paper introduces CANE, a Content Addressed Network Environment, and compares it against current internet and related technologies. Specifically, CANE presents a simple computing environment in which location is abstracted away in favour of identity, and trust is explicitly defined. Identity is cryptographically verified and yet remains pervasively open in nature. It is argued tha...

  8. Amperometric Noise at Thin Film Band Electrodes

    DEFF Research Database (Denmark)

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

    2012-01-01

    polymers and measured the current noise in physiological buffer solution for a wide range of different electrode areas. The noise measurements could be modeled by an analytical expression, representing the electrochemical cell as a resistor and capacitor in series. The studies revealed three domains......; for electrodes with low capacitance, the amplifier noise dominated, for electrodes with large capacitances, the noise from the resistance of the electrochemical cell was dominant, while in the intermediate region, the current noise scaled with electrode capacitance. The experimental results and the model......Background current noise is often a significant limitation when using constant-potential amperometry for biosensor application such as amperometric recordings of transmitter release from single cells through exocytosis. In this paper, we fabricated thin-film electrodes of gold and conductive...

  9. Fluctuations at Electrode-YSZ Interfaces

    DEFF Research Database (Denmark)

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

    \\textbf{Fluctuations at Electrode -- YSZ Interfaces}[\\topsep] T.\\,Jacobsen$^a$, K.\\,Vels Hansen$^b$, E.\\,Skou$^c$[1ex] $^a$Dept.\\,of Chemistry, Technical University of Denmark, DK-2800 Kgs.\\,Lyngby, Denmark.[0.5ex] $^b$Materials Research Dept., Ris\\o\\ National Laboratory, DK-4000 Roskilde, Denmark.......[0.5ex] $^c$ Dept.\\,of Chemistry, University of Southern Denmark, DK-5230 Odense M, Denmark. \\end{center}%\\ [\\topsep] From experiments on electrodes on YSZ surfaces it is well known that a short current or overvoltage pulse can decrease the interfacial impedance leading to an temporary increase...... in performance [\\ref{McEvoy}, \\ref{Adler}]. This sensitivity to the pre-history is probably one of the explanations for the discrepancies between results reported for single electrode studies. The mechanism behind the activation is still an unresolved problem. In the case of point electrodes, i.e. electrodes...

  10. Transient melting of an ESR electrode

    Science.gov (United States)

    Kharicha, A.; Karimi-Sibaki, E.; Bohacek, J.; Wu, M.; Ludwig, A.

    2016-07-01

    Melting parameters of ESR process such as melt rate and immersion depth of electrode are of great importance. In this paper, a dynamic mesh based simulation framework is proposed to model melt rate and shape of electrode during the ESR process. Coupling interactions between turbulent flow, temperature, and electromagnetic fields are fully considered. The model is computationally efficient, and enables us to directly calculate melting parameters. Furthermore, dynamic change of electrode shape by melting can be captured. It is necessary to control the feeding velocity of electrode due to melting instabilities in the ESR process. As such, a numerical control is implemented based on the immersion depth of electrode to achieve the steady state in the simulation. Furthermore, the modeling result is evaluated against an experiment.

  11. Microphonics in biopotential measurements with capacitive electrodes.

    Science.gov (United States)

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

    2010-01-01

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

  12. Politeness Strategies in American Presidential Inaugural Addresses

    Institute of Scientific and Technical Information of China (English)

    李立文; 朱琳靓

    2008-01-01

    American presidential inaugural address(PIA)a very important variety with worldwide influence and long-lasting significance.Its main task and purpose is to outline the main policies of the new government and win people's support.However.the prerequisite of winning people's sympathy and support lies in people's good relationship with and trust in the government.Therefore almost all the speakers resort to"approached-based" positive politeness strategy quite often which performs this function very well.

  13. Partnerships as panacea for addressing global problems?

    OpenAIRE

    Kolk, Ans

    2013-01-01

    textabstractThis chapter examines partnerships and their peculiarities, based on recent research from various disciplines, in the context of the large problems faced by (global) society. These problems are very complex, often cross national boundaries, and cannot easily be 'solved' by one single actor. Previous 'unilateral' attempts to address them have not been particularly successful, and there are limits to what a single actor can do. Cooperation also enables different actors to leverage t...

  14. Forest Policies Addressing Climate Change in China

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    As a developing country with a large population and a fragile ecological environment, China is particularly vulnerable to the adverse effects of climate change. Beginning with the Rio Conference of 1992 China has played a progressively enhanced role in combating climate change. A series of policies and measures to address climate change have been taken in the overall context of national sustainable development strategy, making positive contributions to the mitigation and adaptation to climate change, among ...

  15. Addressing spiritual leadership: an organizational model.

    Science.gov (United States)

    Burkhart, Lisa; Solari-Twadell, P Ann; Haas, Sheila

    2008-01-01

    The Joint Commission requires health systems to address spiritual care. Research indicates that spirituality is associated with better physical, psychological, and social health and that culturally diverse populations and individuals at end-of-life often request spiritual care. The authors report the results of a consensus conference of 21 executives representing 10 large faith-based health systems who discussed the input, process, and outcomes of a corporate model for spiritual leadership. Specific initiatives are highlighted.

  16. Addressing language barriers to healthcare in India.

    Science.gov (United States)

    Narayan, Lalit

    2013-01-01

    In spite of a growing recognition of the importance of doctor-patient communication, the issue of language barriers to healthcare has received very little attention in India. The Indian population speaks over 22 major languages with English used as the lingua franca for biomedicine. Large-scale internal migration has meant that health workers are encountering increasing instances of language discordance within clinical settings. Research done predominantly in the West has shown language discordance to significantly affect access to care, cause problems of comprehension and adherence, and decrease the satisfaction and quality of care. Addressing language barriers to healthcare in India requires a stronger political commitment to providing non-discriminatory health services, especially to vulnerable groups such as illiterate migrant workers. Research will have to address three broad areas: the ways in which language barriers affect health and healthcare, the efficacy of interventions to overcome language barriers, and the costs of language barriers and efforts to overcome them. There is a need to address such barriers in health worker education and clinical practice. Proven strategies such as hiring multilingual healthcare workers, providing language training to health providers, employing in situ translators or using telephone interpretation services will have to be evaluated for their appropriateness to the Indian context. Internet-based initiatives, the proliferation of mobile phones and recent advances in machine translation promise to contribute to the solution. PMID:24758452

  17. Matching Alternative Addresses: a Semantic Web Approach

    Science.gov (United States)

    Ariannamazi, S.; Karimipour, F.; Hakimpour, F.

    2015-12-01

    Rapid development of crowd-sourcing or volunteered geographic information (VGI) provides opportunities for authoritatives that deal with geospatial information. Heterogeneity of multiple data sources and inconsistency of data types is a key characteristics of VGI datasets. The expansion of cities resulted in the growing number of POIs in the OpenStreetMap, a well-known VGI source, which causes the datasets to outdate in short periods of time. These changes made to spatial and aspatial attributes of features such as names and addresses might cause confusion or ambiguity in the processes that require feature's literal information like addressing and geocoding. VGI sources neither will conform specific vocabularies nor will remain in a specific schema for a long period of time. As a result, the integration of VGI sources is crucial and inevitable in order to avoid duplication and the waste of resources. Information integration can be used to match features and qualify different annotation alternatives for disambiguation. This study enhances the search capabilities of geospatial tools with applications able to understand user terminology to pursuit an efficient way for finding desired results. Semantic web is a capable tool for developing technologies that deal with lexical and numerical calculations and estimations. There are a vast amount of literal-spatial data representing the capability of linguistic information in knowledge modeling, but these resources need to be harmonized based on Semantic Web standards. The process of making addresses homogenous generates a helpful tool based on spatial data integration and lexical annotation matching and disambiguating.

  18. Innovative Legal Approaches to Address Obesity

    Science.gov (United States)

    Pomeranz, Jennifer L; Teret, Stephen P; Sugarman, Stephen D; Rutkow, Lainie; Brownell, Kelly D

    2009-01-01

    Context: The law is a powerful public health tool with considerable potential to address the obesity issue. Scientific advances, gaps in the current regulatory environment, and new ways of conceptualizing rights and responsibilities offer a foundation for legal innovation. Methods: This article connects developments in public health and nutrition with legal advances to define promising avenues for preventing obesity through the application of the law. Findings: Two sets of approaches are defined: (1) direct application of the law to factors known to contribute to obesity and (2) original and innovative legal solutions that address the weak regulatory stance of government and the ineffectiveness of existing policies used to control obesity. Specific legal strategies are discussed for limiting children's food marketing, confronting the potential addictive properties of food, compelling industry speech, increasing government speech, regulating conduct, using tort litigation, applying nuisance law as a litigation strategy, and considering performance-based regulation as an alternative to typical regulatory actions. Finally, preemption is an overriding issue and can play both a facilitative and a hindering role in obesity policy. Conclusions: Legal solutions are immediately available to the government to address obesity and should be considered at the federal, state, and local levels. New and innovative legal solutions represent opportunities to take the law in creative directions and to link legal, nutrition, and public health communities in constructive ways. PMID:19298420

  19. Textile electrode characterization: dependencies in the skin-clothing-electrode interface

    Science.gov (United States)

    Macías, R.; Fernández, M.; Bragós, R.

    2013-04-01

    Given the advances in the technology known as smart textiles, the use of textile electrodes is more and more common. However this kind of electrodes presents some differences regarding the standard ones as the Ag-AgCl electrodes. Therefore to characterize them as best as possible is required. In order to make the characterization reproducible and repetitive, a skin dummy made of agar-agar and a standardized measurement set-up is used in this article. Thus, some dependencies in the skin-electrode interface are described. These dependencies are related to the surface of the textile electrode, the conductive material and the applied pressure. Furthermore, the dependencies on clothing in the skin-textile electrode interface are also analyzed. Thus, based on some parameters such as textile material, width and number of layers, the behavior of the interface made up by the skin, the textile electrode and clothing is depicted.

  20. Optimization of return electrodes in neurostimulating arrays

    Science.gov (United States)

    Flores, Thomas; Goetz, Georges; Lei, Xin; Palanker, Daniel

    2016-06-01

    Objective. High resolution visual prostheses require dense stimulating arrays with localized inputs of individual electrodes. We study the electric field produced by multielectrode arrays in electrolyte to determine an optimal configuration of return electrodes and activation sequence. Approach. To determine the boundary conditions for computation of the electric field in electrolyte, we assessed current dynamics using an equivalent circuit of a multielectrode array with interleaved return electrodes. The electric field modeled with two different boundary conditions derived from the equivalent circuit was then compared to measurements of electric potential in electrolyte. To assess the effect of return electrode configuration on retinal stimulation, we transformed the computed electric fields into retinal response using a model of neural network-mediated stimulation. Main results. Electric currents at the capacitive electrode-electrolyte interface redistribute over time, so that boundary conditions transition from equipotential surfaces at the beginning of the pulse to uniform current density in steady state. Experimental measurements confirmed that, in steady state, the boundary condition corresponds to a uniform current density on electrode surfaces. Arrays with local return electrodes exhibit improved field confinement and can elicit stronger network-mediated retinal response compared to those with a common remote return. Connecting local return electrodes enhances the field penetration depth and allows reducing the return electrode area. Sequential activation of the pixels in large monopolar arrays reduces electrical cross-talk and improves the contrast in pattern stimulation. Significance. Accurate modeling of multielectrode arrays helps optimize the electrode configuration to maximize the spatial resolution, contrast and dynamic range of retinal prostheses.

  1. Ninety-six-well planar lipid bilayer chip for ion channel recording fabricated by hybrid stereolithography.

    Science.gov (United States)

    Suzuki, Hiroaki; Le Pioufle, Bruno; Takeuchi, Shoji

    2009-02-01

    We present a micro fluidic chip for parallel ion channel recording in a large array of artificial planar lipid bilayer membranes. To realize a composite structure that features an array of recording wells with free-standing microapertures for lipid bilayer reconstitution, the device was fabricated by the hybrid stereolithography technology, in which a Parylene film with pre-formed microapertures was inserted during the rapid stereolithography process. We designed and tested a hybrid chip that has 96 (12x8) addressable recording wells to demonstrate recording of ion channel current in high-throughput manner. Measurement was done by sequentially moving the recording electrode, and, as a result, the channel current of model membrane protein was detected in 44 wells out of 96. We also showed that this hybrid fabrication process was capable of integrating micropatterned electrodes suitable for automated recording. These results support the efficiency of our present architecture of the parallel ion channel recording chip toward realization of the high-throughput screening of ion channel proteins in the artificial lipid bilayer system.

  2. Electrode assembly for a lithium ion battery, process for the production of such electrode assembly, and lithium ion battery comprising such electrode assemblies

    NARCIS (Netherlands)

    Mulder, F.M.; Wagemaker, M.

    2013-01-01

    The invention provides an electrode assembly for a lithium ion battery, the electrode assembly comprising a lithium storage electrode layer on a current collector, wherein the lithium storage electrode layer is a porous layer having a porosity in the range of -35 %, with pores having pore widths in

  3. Defect Detection in Fuel Cell Gas Diffusion Electrodes Using Infrared Thermography

    Energy Technology Data Exchange (ETDEWEB)

    Ulsh, Michael; Porter, Jason M.; Bittinat, Daniel C.; Bender, Guido

    2016-04-01

    Polymer electrolyte membrane fuel cells are energy conversion devices that offer high power densities and high efficiencies for mobile and other applications. Successful introduction into the marketplace requires addressing cost barriers such as production volumes and platinum loading. For cost reduction, it is vital to minimize waste and maximize quality during the manufacturing of platinum-containing electrodes, including gas diffusion electrodes (GDEs). In this work, we report on developing a quality control diagnostic for GDEs, involving creating an ex situ exothermic reaction on the electrode surface and using infrared thermography to measure the resulting temperature profile. Experiments with a moving GDE containing created defects were conducted to demonstrate the applicability of the diagnostic for real-time web-line inspection.

  4. Highly accurate apparatus for electrochemical characterization of the felt electrodes used in redox flow batteries

    Science.gov (United States)

    Park, Jong Ho; Park, Jung Jin; Park, O. Ok; Jin, Chang-Soo; Yang, Jung Hoon

    2016-04-01

    Because of the rise in renewable energy use, the redox flow battery (RFB) has attracted extensive attention as an energy storage system. Thus, many studies have focused on improving the performance of the felt electrodes used in RFBs. However, existing analysis cells are unsuitable for characterizing felt electrodes because of their complex 3-dimensional structure. Analysis is also greatly affected by the measurement conditions, viz. compression ratio, contact area, and contact strength between the felt and current collector. To address the growing need for practical analytical apparatus, we report a new analysis cell for accurate electrochemical characterization of felt electrodes under various conditions, and compare it with previous ones. In this cell, the measurement conditions can be exhaustively controlled with a compression supporter. The cell showed excellent reproducibility in cyclic voltammetry analysis and the results agreed well with actual RFB charge-discharge performance.

  5. Electrode effect for hydrodynamic plasma edge

    International Nuclear Information System (INIS)

    General turbulent diffusion processes of the light ions towards electrode in weakly ionized hydrodynamic plasma edge are analyzed. The system of equations for turbulent diffusion of the light ions towards electrode under certain boundary conditions (selective capture of the light negative ions on electrode's surface) is solved. On the other hand inside boundary layer there is a laminar layer near electrode's surface. Here, the kinetic diffusion is a main mechanism for diffusion of the light ions toward electrode. Over boundary layer the turbulent diffusion is a prevailing mechanism. As it stands, a new model for quasi boundary layer of diffusion is proposed and used for the general analysis of experimental results on negative charging of material surface in ionized air (Chalmers, Pasquill, Phillips and Gunn). Briefly, one can say that negative equilibrium potentials of electrode is proportional to logarithm of (N+/N-) ratio. From its slope we can obtain the thickness of quasi-boundary layer of diffusion, that is compatible with boundary layer thickness. On the other hand a turbulent double layer is defined. Its characteristic length is much longer than Debye length. The energy produced by electric field of diffusion comes from the chaotic energy of turbulent eddies. The electric field of diffusion and its current (called compensatory current) will balance the ionic fluxes towards electrode. (authors)

  6. A Task Force to Address Bullying.

    Science.gov (United States)

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

    2016-02-01

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

  7. Panels and Lectures Address China Controversies

    Directory of Open Access Journals (Sweden)

    Video Resources

    2010-04-01

    Full Text Available Editors note: Over the past several months, colleagues have brought to our attention three public panel discussions and lectures that address contemporary controversies in Chinese studies. These discussions have been video-recorded and are available to view on the internet. These presentations may be useful either for scholarly pursuits or may be excerpted for classroom viewing. We wish to thank those who contacted us about these resources, and we encourage readers who know of other such video resources to let us know about them so that we can inform our ASIANetwork colleagues of their existence and availability.

  8. A Task Force to Address Bullying.

    Science.gov (United States)

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

    2016-02-01

    Bullying in the workplace can create a dysfunctional environment that is associated with serious physical and psychological harm to the person being bullied. Nurses' experience with bullying has gained considerable attention in recent years, and warrants further discussion. Nurse leaders need to develop and implement effective bullying prevention initiatives that will foster the functioning of a professional and productive staff in a healthy work environment. The aim of this article is to review workplace bullying as experienced by nurses, and describe how nurses at a Magnet-designated academic medical center developed and implemented a bullying task force to address the problem. PMID:26817556

  9. Grid Added Value to Address Malaria

    CERN Document Server

    Breton, V; Hofmann, M

    2008-01-01

    Through this paper, we call for a distributed, internet-based collaboration to address one of the worst plagues of our present world, malaria. The spirit is a non-proprietary peer-production of information-embedding goods. And we propose to use the grid technology to enable such a world wide "open source" like collaboration. The first step towards this vision has been achieved during the summer on the EGEE grid infrastructure where 46 million ligands were docked for a total amount of 80 CPU years in 6 weeks in the quest for new drugs.

  10. HEP technologies to address medical imaging challenges

    CERN Document Server

    CERN. Geneva

    2016-01-01

    Developments in detector technologies aimed at solving challenges in present and future CERN experiments, particularly at the LHC, have triggered exceptional advances in the performance of medical imaging devices, allowing for a spectacular progress in in-vivo molecular imaging procedures, which are opening the way for tailored therapies of major diseases. This talk will briefly review the recent history of this prime example of technology transfer from HEP experiments to society, will describe the technical challenges being addressed by some ongoing projects, and will present a few new ideas for further developments and their foreseeable impact.

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

    Science.gov (United States)

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

    2016-08-01

    Microneedle-based ‘dry’ electrodes have immense potential for use in diagnostic procedures such as electrocardiography (ECG) analysis, as they eliminate several of the drawbacks associated with the conventional ‘wet’ electrodes currently used for physiological signal recording. To be commercially successful in such a competitive market, it is essential that dry electrodes are manufacturable in high volumes and at low cost. In addition, the topographical nature of these emerging devices means that electrode performance is likely to be highly dependent on the quality of the skin-electrode contact. This paper presents a low-cost, wafer-level micromoulding technology for the fabrication of polymeric ECG electrodes that use microneedle structures to make a direct electrical contact to the body. The double-sided moulding process can be used to eliminate post-process via creation and wafer dicing steps. In addition, measurement techniques have been developed to characterize the skin-electrode contact force. We perform the first analysis of signal-to-noise ratio dependency on contact force, and show that although microneedle-based electrodes can outperform conventional gel electrodes, the quality of ECG recordings is significantly dependent on temporal and mechanical aspects of the skin-electrode interface.

  12. Effect of electrode fabrication methods on the electrode performance for ethanol oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Qin, Yuan-Hang; Li, Hui-Cheng; Yang, Hou-Hua; Zhang, Xin-Sheng; Zhou, Xing-Gui; Yuan, Wei-Kang [State Key Laboratory of Chemical Engineering, East China University of Science and Technology, Shanghai 200237 (China); Niu, Li [State Key Laboratory of Electroanalytical Chemistry, Chang Chun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China)

    2011-01-01

    Two palladium/carbon nanofibers modified glassy carbon electrodes, Pd/CNFs/GC-C and Pd/CNFs/GC-E, are fabricated by the conventional powder type method and by the electrophoretic deposition in conjunction with pulse electrodeposition method, respectively. Field emission scanning electron microscopy and high resolution transmission electron microscopy reveal that Pd particles are uniformly dispersed on the two electrodes and X-ray diffraction shows the average Pd particle size of the Pd/CNFs/GC-E electrode is slightly larger than that of the Pd/CNFs/GC-C electrode. Cyclic voltammetric analysis shows that the electrocatalytic activity of Pd/CNFs/GC-E electrode is better than that of Pd/CNFs/GC-C electrode for ethanol oxidation in alkaline media, although the latter has higher Pd loading than the former. This is believed to be due to the higher utilization of Pd catalyst on Pd/CNFs/GC-E electrode than on Pd/CNFs/GC-C electrode, which is confirmed by the electrochemically active surface area measurements. In addition, chronopotentiometric analysis shows the long-term operation stability of Pd/CNFs/GC-E electrode is better than that of Pd/CNFs/GC-C electrode. (author)

  13. Improved technology for manufacture of carbon electrodes

    Indian Academy of Sciences (India)

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

    2000-02-01

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

  14. Capacitive Substrate Coupling of Row–Column-Addressed 2-D CMUT Arrays

    DEFF Research Database (Denmark)

    Engholm, Mathias; Bouzari, Hamed; Jensen, Jørgen Arendt;

    2016-01-01

    the semiconductor substrate. To reduce the parasitic capacitance by 80% the bulk doping concentration should be at most 1012 cm-3. Experimental results show that the parasitic capacitance can be reduced by 87% by applying a substrate potential of 6V relative to the bottom electrodes. The depletion......Row–column-addressed CMUT arrays suffer from low receive sensitivity of the bottom elements due to a capacitive coupling to the substrate. The capacitive coupling increases the parasitic capacitance. A simple approach to reduce the parasitic capacitance is presented, which is based on depleting...... of the semiconductor substrate can be sustained for at least 10 minutes making it applicable for row–column-addressed CMUT arrays for ultrasonic imaging. Theoretically the reduced parasitic capacitance indicates that the receive sensitivity of the bottom elements can be increased by a factor of 2:1....

  15. Results Analysis of IP Address Auto- Configuration in Wireless Manets

    OpenAIRE

    S.Zahoor Ul Huq; S. Shabana Begum; Dr. K.E.Sreenivasa Murthy; Prof. B. Satyanaryana

    2011-01-01

    The main task of an address allocation protocol is to manage the address allocation to the nodes in the ad hoc MANETs. All routing protocols assume nodes to be configured a priori with a uniqueIP address. Allocating addresses to mobile nodes is a fundamental and difficult problem. A mobile device cannot participate in unicast communications until it is assigned a conflict-free IP address. So addressing in MANETs is of significant importance, and the address configuration process should be fas...

  16. Scalloped electrodes for highly sensitive electrical measurements

    DEFF Research Database (Denmark)

    Vazquez Rodriguez, Patricia; Dimaki, Maria; Svendsen, Winnie Edith

    2011-01-01

    In this work we introduce a novel out-of-plane electrode with pronounced scalloped surface and high aspect ratio for electrical recordings of brain tissue in vitro, with the aim to reduce significantly the impedance of the measuring system. The profile and height of the structures is tailored...... an important improvement in comparison with already available systems. Additionally, first test of durability prove the robustness of these needle-like electrodes during indentation motions. In conclusion, the resulting electrodes are robust, sharp structures that decrease the typical impedance...

  17. Soft textile electrodes for EEG monitoring

    OpenAIRE

    Löfhed, Johan; Seoane, Fernando; Thordstein, Magnus

    2010-01-01

    There is a need for long term monitoring of the brain during intensive care. This is e.g. the case for newborn babies that have been exposed to hypoxia during delivery. Electroencephalography (EEG) is the technique of choice. To get a clear and detailed view of the brain activity a large number of EEG electrodes should be used. Applying traditional electrodes one by one is a time-consuming and technically demanding work and therefore electrode caps are sometimes used. The existing caps have h...

  18. Polymer-Based Cantilevers with Integrated Electrodes

    OpenAIRE

    Mouaziz, S.; Boero, G.; Popovic, R; J. Brugger

    2006-01-01

    An innovative release method of polymer cantilevers with embedded integrated metal electrodes is presented. The fabrication is based on the lithographic patterning of the electrode layout on a wafer surface, covered by two layers of SU-8 polymer: a 10-um-thick photo-structured layer for the cantilever, and a 200-um-thick layer for the chip body. The releasing method is based on dry etching of a 2-um-thick sacrificial polysilicon layer. Devices with complex electrode layout embedded in free-st...

  19. Conducting polymer electrodes for gel electrophoresis.

    Directory of Open Access Journals (Sweden)

    Katarina Bengtsson

    Full Text Available In nearly all cases, electrophoresis in gels is driven via the electrolysis of water at the electrodes, where the process consumes water and produces electrochemical by-products. We have previously demonstrated that π-conjugated polymers such as poly(3,4-ethylenedioxythiophene (PEDOT can be placed between traditional metal electrodes and an electrolyte to mitigate electrolysis in liquid (capillary electroosmosis/electrophoresis systems. In this report, we extend our previous result to gel electrophoresis, and show that electrodes containing PEDOT can be used with a commercial polyacrylamide gel electrophoresis system with minimal impact to the resulting gel image or the ionic transport measured during a separation.

  20. A method for making a nickel electrode

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, I.; Ikeyama, M.; Isikava, T.; Ivaki, T.; Yanashkhara, N.

    1983-07-14

    A powder of an active mass is applied to a foam metal plate and it is pressed into the pores of the base. The excess mass is removed from the surface, after which a grid structure is formed on this surface with heating of a powder of a thermally seating resin of the polyethylene type. Then, submerging the electrode plate into the resin suspension, the entire surface of the electrode is covered with a thin layer of powder of a fluorine bearing resin. The electrode has a long service life.

  1. Notation for national and international telephone numbers, e-mail addresses and Web addresses

    CERN Document Server

    International Telecommunication Union. Geneva

    2001-01-01

    Recommendation E.123 defines a standard way to write telephone numbers, e-mail addresses, and web addresses. It recommends the following formats (when dialing the area code is optional for local calling): Telephone number: National notation (042) 123 4567 International notation +31 (0)42 123 4567 E-mail address: name@provider.com Internet address / URL: www.company.com It also recommends that a hypen (-), space ( ), or period (.) can be used to visually separate groups of numbers. The parentheses are used to indicate digits that are sometimes not dialed. a slash (/) is used to indicate alternate numbers. This information is important if you want to make sure people know how to dail a phone number in a specific country.

  2. Energy photoconversion using molybdenite electrodes

    Energy Technology Data Exchange (ETDEWEB)

    D' Oliveira, N.; Monnereau, O.; Vacquier, G.; Cerclier, O.; Casalot, A. (Universite de Provence, 13 - Marseille (France))

    1982-01-01

    Semi-conductor electrode preparation methods, from natural state molybdenites MoS/sub 2/ or from synthetized ones are studied for electrochemical cells. A radiocrystallographic study shows that the various molybdenites get a crystal state with a structure coming from CdI/sub 2/ (2H of 4H polytypes); Norway MoS/sub 2/ variety being changed by annealing at 800/sup 0/C from 4H type to 2H one. Using a Seebeck effect method, all the samples, except MoS/sub 2/ Madagascar, give an n-type conductivity. According to a systematic study of various parameters (sample origins, lightning conditions, electrolytic solution pH, ionic species concentration, solution temperature, material composition) experimental conditions for the best photocurrent increase are determined. Every sample, except Madagascar MoS/sub 2/ one, acts as an anode, the most active being Australia MoS/sub 2/. Norway MoS/sub 2/, in its natural state, gives its best when lit tangentially in a sheet-plan, under a more than 1V voltage. Performance is even better after an annealing at 800/sup 0/C and crushing at an about 40 ..mu..m granulometry, followed by a new thermic treatment and by using an electrolyte whose concentration is at least 5.10/sup -3/M in I/sup -/ions, with a very acid pH.

  3. Addressing submarine geohazards through scientific drilling

    Science.gov (United States)

    Camerlenghi, A.

    2009-04-01

    Natural submarine geohazards (earthquakes, volcanic eruptions, landslides, volcanic island flank collapses) are geological phenomena originating at or below the seafloor leading to a situation of risk for off-shore and on-shore structures and the coastal population. Addressing submarine geohazards means understanding their spatial and temporal variability, the pre-conditioning factors, their triggers, and the physical processes that control their evolution. Such scientific endeavour is nowadays considered by a large sector of the international scientific community as an obligation in order to contribute to the mitigation of the potentially destructive societal effects of submarine geohazards. The study of submarine geohazards requires a multi-disciplinary scientific approach: geohazards must be studied through their geological record; active processes must be monitored; geohazard evolution must be modelled. Ultimately, the information must be used for the assessment of vulnerability, risk analysis, and development of mitigation strategies. In contrast with the terrestrial environment, the oceanic environment is rather hostile to widespread and fast application of high-resolution remote sensing techniques, accessibility for visual inspection, sampling and installation of monitoring stations. Scientific Drilling through the IODP (including the related pre site-survey investigations, sampling, logging and in situ measurements capability, and as a platform for deployment of long term observatories at the surface and down-hole) can be viewed as the centre of gravity of an international, coordinated, multi-disciplinary scientific approach to address submarine geohazards. The IODP Initial Science Plan expiring in 2013 does not address openly geohazards among the program scientific objectives. Hazards are referred to mainly in relation to earthquakes and initiatives towards the understanding of seismogenesis. Notably, the only drilling initiative presently under way is the

  4. Rank Based Selection of Electrode Positions for a Multi-Lead ECG Electrode Array.

    Science.gov (United States)

    Hintermuller, Christoph; Fischer, Gerald; Seger, Michael; Pfeifer, Bernhard; Modre, Robert; Tilg, Bernhard

    2005-01-01

    Methods for noninvasive imaging of electrical function of the heart seem to become a clinical standard procedure the next years. Thus, the overall procedure has to meet clinical requirements as easy and fast application. In this study we propose a new electrode array meeting clinical requirements such as easy to apply and compatibility with routine leads. Within body surface regions of high sensitivity, identified in a prior, information content based study, the number of required electrodes was optimized using effort-gain plots. These plots were generated by applying a so called type one detector criterion. The optimal array was selected from a set of 12 electrode arrays. Each of them consists of two L-shaped regular spaced parts. The optimal array was found by comparing several layouts and electrode densities to the electrode array we use for clinical studies. It consists of 125 electrodes with a regular spacing between 2cm and 3cm.

  5. Metal electrode dependent field effect transistors made of lanthanide ion-doped DNA crystals

    Science.gov (United States)

    Reddy Dugasani, Sreekantha; Hwang, Taehyun; Kim, Jang Ah; Gnapareddy, Bramaramba; Kim, Taesung; Park, Sung Ha

    2016-03-01

    We fabricated lanthanide ion (Ln3+, e.g. Dy3+, Er3+, Eu3+, and Gd3+)-doped self-assembled double-crossover (DX) DNA crystals grown on the surface of field effect transistors (FETs) containing either a Cr, Au, or Ni electrode. Here we demonstrate the metal electrode dependent FET characteristics as a function of various Ln3+. The drain-source current (I ds), controlled by the drain-source voltage (V ds) of Ln3+-doped DX DNA crystals with a Cr electrode on an FET, changed significantly under various gate voltages (V g) due to the relative closeness of the work function of Cr to the energy band gap of Ln3+-DNA crystals compared to those of Au and Ni. For Ln3+-DNA crystals on an FET with either a Cr or Ni electrode at a fixed V ds, I ds decreased with increasing V g ranging from  -2 to 0 V and from 0 to  +3 V in the positive and negative regions, respectively. By contrast, I ds for Ln3+-DNA crystals on an FET with Au decreased with increasing V g in only the positive region due to the greater electronegativity of Au. Furthermore, Ln3+-DNA crystals on an FET exhibited behaviour sensitive to V g due to the appreciable charge carriers generated from Ln3+. Finally, we address the resistivity and the mobility of Ln3+-DNA crystals on an FET with different metal electrodes obtained from I ds-V ds and I ds-V g curves. The resistivities of Ln3+-DNA crystals on FETs with Cr and Au electrodes were smaller than those of pristine DNA crystals on an FET, and the mobility of Ln3+-DNA crystals on an FET with Cr was relatively higher than that associated with other electrodes.

  6. Address Forms in Chinese and English-Speaking Culture

    Institute of Scientific and Technical Information of China (English)

    王晓茹

    2015-01-01

    Address forms is one of markers of politeness and is an indispensable part of communication. An appropriate address form promotes interpersonal communication smoothly. An address form is polite in one culture, but might be inappropriate in an⁃other culture. The paper contrasts address forms in English and Chinese culture and explores the reasons for their different choice of address terms.

  7. Electrochemical properties of porous bismuth electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Romann, T., E-mail: tavo.romann@ut.e [Institute of Chemistry, University of Tartu, Ravila 14A, 50411 Tartu (Estonia); Lust, E. [Institute of Chemistry, University of Tartu, Ravila 14A, 50411 Tartu (Estonia)

    2010-08-01

    The properties of Bi surfaces with different roughnesses were characterized by electron microscopy, cyclic voltammetry, and impedance spectroscopy. Two different strategies were used for preparation of porous bismuth layers onto Bi microelectrode surface in aqueous 0.1 M LiClO{sub 4} solution. Firstly, treatment at potential E < -2 V (vs. Ag|AgCl in sat. KCl) has been applied, resulting in bismuth hydride formation and decomposition into Bi nanoparticles which deposit at the electrode surface. Secondly, porous Bi layer was prepared by anodic dissolution (E = 1 V) of bismuth electrode followed by fast electroreduction of formed Bi{sup 3+} ions at cathodic potentials E = -2 V. The nanostructured porous bismuth electrode, with surface roughness factor up to 220, has negligible frequency dispersion of capacitance and higher hydrogen evolution overvoltage than observed for smooth Bi electrodes.

  8. Solid Reference Electrode of Metallurgical Oxygen Sensor

    Institute of Scientific and Technical Information of China (English)

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

    2006-01-01

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

  9. Surface protected lithium-metal-oxide electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Thackeray, Michael M.; Kang, Sun-Ho

    2016-04-05

    A lithium-metal-oxide positive electrode having a layered or spinel structure for a non-aqueous lithium electrochemical cell and battery is disclosed comprising electrode particles that are protected at the surface from undesirable effects, such as electrolyte oxidation, oxygen loss or dissolution by one or more lithium-metal-polyanionic compounds, such as a lithium-metal-phosphate or a lithium-metal-silicate material that can act as a solid electrolyte at or above the operating potential of the lithium-metal-oxide electrode. The surface protection significantly enhances the surface stability, rate capability and cycling stability of the lithium-metal-oxide electrodes, particularly when charged to high potentials.

  10. Ni-Based Solid Oxide Cell Electrodes

    DEFF Research Database (Denmark)

    Mogensen, Mogens Bjerg; Holtappels, Peter

    2013-01-01

    . The main emphasis will be on the following subjects: (a) electronic conductivity of cermets, (b) dimensional and thermodynamic stability including redox cycling, © thermal expansion coefficient matching, (d) chemical compatibility with stack components and gaseous reactants and (e) electrode reaction......This paper is a critical review of the literature on nickel-based electrodes for application in solid oxide cells at temperature from 500 to 1000 _C. The applications may be fuel cells or electrolyser cells. The reviewed literature is that of experimental results on both model electrodes...... and practical composite cermet electrodes. A substantially longer three-phase boundary (TPB) can be obtained per unit area of cell in such a composite of nickel and electrolyte material, provided that two interwoven solid networks of the two solid and one gaseous phases are obtained to provide a three...

  11. Electrode structure for uniform corona discharge

    Science.gov (United States)

    Gange, R. A.; Steinmetz, C. C.

    1976-01-01

    Single corona-discharge needle is used to apply uniform charge to thermoplastic medium in holograph-storage system. Needle is connected to flat transparent electrode that is parallel to thermoplastic.

  12. Advanced membrane electrode assemblies for fuel cells

    Science.gov (United States)

    Kim, Yu Seung; Pivovar, Bryan S

    2014-02-25

    A method of preparing advanced membrane electrode assemblies (MEA) for use in fuel cells. A base polymer is selected for a base membrane. An electrode composition is selected to optimize properties exhibited by the membrane electrode assembly based on the selection of the base polymer. A property-tuning coating layer composition is selected based on compatibility with the base polymer and the electrode composition. A solvent is selected based on the interaction of the solvent with the base polymer and the property-tuning coating layer composition. The MEA is assembled by preparing the base membrane and then applying the property-tuning coating layer to form a composite membrane. Finally, a catalyst is applied to the composite membrane.

  13. Electrodes for Microfluidic Integrated Optoelectronic Tweezers

    Directory of Open Access Journals (Sweden)

    Kuo-Wei Huang

    2011-01-01

    Full Text Available We report on two types of electrodes that enable the integration of optoelectronic tweezers (OETs with multilayer poly(dimethylsilane- (PDMS- based microfluidic devices. Both types of electrodes, Au-mesh and single-walled carbon nanotube- (SWNT- embedded PDMS thin film, are optically transparent, electrically conductive, and can be mechanically deformed and provide interfaces to form strong covalent bonding between an OET device and PDMS through standard oxygen plasma treatment. Au-mesh electrodes provide high electrical conductivity and high transparency but are lack of flexibility and allow only small deformation. On the other hand, SWNT-embedded PDMS thin film electrodes provide not only electrical conductivity but also optical transparency and can undergo large mechanical deformation repeatedly without failure. This enables, for the first time, microfluidic integrated OET with on-chip valve and pump functions, which is a critical step for OET-based platforms to conduct more complex and multistep biological and biochemical analyses.

  14. Field Emission Measurements from Niobium Electrodes

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-03-01

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

  15. Thin metal electrodes for semitransparent organic photovoltaics

    KAUST Repository

    Lee, Kyusung

    2013-08-01

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

  16. 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.

  17. An electrode for a chemical power source

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, I.; Ivaki, T.; Yanashkara, N.

    1983-07-29

    A metal which has a spongy structure is used as the electrode base for the chemical current source (KhIT). The majority of pores has a spindle shaped form and is identically oriented along the direction of the long axis. The size of the pores along the short diameter is 5 to 30 percent of the pore size along the long diameter. The length of a pore along the long axis is 100 to 500 micrometers. In making the electrode the pores are filled with an active mass. The electrode is manufactured in the form of a strip which is turned in a direction perpendicular to the long axis of the pores. The electrodes have excellent characteristics.

  18. Electrode geometry for electrostatic generators and motors

    Science.gov (United States)

    Post, Richard F.

    2016-02-23

    An electrostatic (ES) device is described with electrodes that improve its performance metrics. Devices include ES generators and ES motors, which are comprised of one or more stators (stationary members) and one or more rotors (rotatable members). The stator and rotors are configured as a pair of concentric cylindrical structures and aligned about a common axis. The stator and rotor are comprised of an ensemble of discrete, longitudinal electrodes, which are axially oriented in an annular arrangement. The shape of the electrodes described herein enables the ES device to function at voltages significantly greater than that of the existing art, resulting in devices with greater power-handling capability and overall efficiency. Electrode shapes include, but are not limited to, rods, corrugated sheets and emulations thereof.

  19. Addressing consumerization of IT risks with nudging

    Directory of Open Access Journals (Sweden)

    Iryna Yevseyeva

    2015-01-01

    Full Text Available In this work we address the main issues of Information Technology (IT consumerization that are related to security risks, and vulnerabilities of devices used within Bring Your Own Device (BYOD strategy in particular. We propose a ‘soft’ mitigation strategy for user actions based on nudging, widely applied to health and social behavior influence. In particular, we propose a complementary, less strict, more flexible Information Security policies, based on risk assessment of device vulnerabilities and threats to corporate data and devices, combined with a strategy of influencing security behavior by nudging. We argue that nudging, by taking into account the context of the decision-making environment, and the fact that the employee may be in better position to make a more appropriate decision, may be more suitable than strict policies in situations of uncertainty of security-related decisions. Several examples of nudging are considered for different tested and potential scenarios in security context.

  20. Programming chemistry in DNA-addressable bioreactors

    DEFF Research Database (Denmark)

    Fellermann, H.; Cardelli, L.

    2014-01-01

    We present a formal calculus, termed the chemtainer calculus, able to capture the complexity of compartmentalized reaction systems such as populations of possibly nested vesicular compartments. Compartments contain molecular cargo as well as surface markers in the form of DNA single strands....... These markers serve as compartment addresses and allow for their targeted transport and fusion, thereby enabling reactions of previously separated chemicals. The overall system organization allows for the set-up of programmable chemistry in microfluidic or other automated environments. We introduce a simple...... sequential programming language whose instructions are motivated by state of-the-art microfluidic technology. Our approach integrates electronic control, chemical computing and material production in a unified formal framework that is able to mimic the integrated computational and constructive capabilities...

  1. World Federation of Vascular Societies: presidential address

    DEFF Research Database (Denmark)

    Sillesen, Henrik Hegaard

    2010-01-01

    The presidential address describes briefly the history of the World Federation for Vascular Societies (WFVS) and its objectives. Vascular Surgery today includes interventional procedures (open surgical and endovascular) in addition to risk factor reduction and medical treatment. It is equally...... is best for other reasons, i.e. financial. Due to the increasing complex procedures - endovascular evolution and what is then "left" for open surgery - specialisation into "mainly open vascular surgeon" and "mainly endovascular surgeon" preceded by a common basic training into both, seems unavoidable...... important to train in clinical investigative methods, non-surgical treatment, decision making as is training in technical aspects of interventions. Similarly, it is vital, that the vascular specialist always recommends the treatment which is best to the individual patient, not only what he can do or what...

  2. Library outreach: addressing Utah's "Digital Divide".

    Science.gov (United States)

    McCloskey, K M

    2000-10-01

    A "Digital Divide" in information and technological literacy exists in Utah between small hospitals and clinics in rural areas and the larger health care institutions in the major urban area of the state. The goals of the outreach program of the Spencer S. Eccles Health Sciences Library at the University of Utah address solutions to this disparity in partnership with the National Network of Libraries of Medicine-- Midcontinental Region, the Utah Department of Health, and the Utah Area Health Education Centers. In a circuit-rider approach, an outreach librarian offers classes and demonstrations throughout the state that teach information-access skills to health professionals. Provision of traditional library services to unaffiliated health professionals is integrated into the library's daily workload as a component of the outreach program. The paper describes the history, methodology, administration, funding, impact, and results of the program.

  3. Professional Culture and Climate: Addressing Unconscious Bias

    Science.gov (United States)

    Knezek, Patricia

    2016-10-01

    Unconscious bias reflects expectations or stereotypes that influence our judgments of others (regardless of our own group). Everyone has unconscious biases. The end result of unconscious bias can be an accumulation of advantage or disadvantage that impacts the long term career success of individuals, depending on which biases they are subject to. In order to foster a professional culture and climate, being aware of these unconscious biases and mitigating against them is a first step. This is particularly important when judgements are needed, such as in cases for recruitment, choice of speakers for conferences, and even reviewing papers submitted for publication. This presentation will cover how unconscious bias manifests itself, what evidence exists to demonstrate it exists, and ways it can be addressed.

  4. Addressing food waste reduction in Denmark

    DEFF Research Database (Denmark)

    Halloran, Afton Marina Szasz; Clement, Jesper; Kornum, Niels;

    2014-01-01

    . In order to better understand food waste and loss more research must be conducted on the total amount of food waste at every level of the food supply chain. Solutions can be found through improved communication, more efficient food packaging, and better in interpretation of food labels by consumers......Global food demand is driven by population and economic growth, and urbanization. One important instrument to meet this increasing demand and to decrease the pressure on food production is to minimize food losses and food waste. Food waste and loss is a major societal, economic, nutritional...... and environmental challenge. Using the case of Denmark, this paper analyses causes of food waste, and discusses how different stakeholders address the prevention and reuse of the €1.18. billion of annual edible food waste. Currently, the majority of food waste is still incinerated with energy recovery. However...

  5. Wall-jet electrode linear sweep voltammetry

    OpenAIRE

    Compton, Richard G.; Fisher, Adrian C.; Latham, Mark H.; Brett, Christopher M. A.; Brett, Ana Maria C. F. Oliveira

    1992-01-01

    Theory is presented which predicts the linear sweep voltammetry behavior at the wall-jet electrode for a reversible couple. The scan rate and electrode geometry dependences are established, and hence the requirements for the measurement of true “steady state” hydrodynamic voltammograms are defmed. Theory is found to be in good agreement with experiments conducted on the oxidation of the ferrocyanide anion in aqueous solution

  6. Electrodes for Microfluidic Integrated Optoelectronic Tweezers

    OpenAIRE

    Kuo-Wei Huang; Sabbir Sattar; Zhong, Jiang F.; Cheng-Hsu Chou; Hsiung-Kuang Tsai; Pei-Yu Chiou

    2011-01-01

    We report on two types of electrodes that enable the integration of optoelectronic tweezers (OETs) with multilayer poly(dimethylsilane)- (PDMS-) based microfluidic devices. Both types of electrodes, Au-mesh and single-walled carbon nanotube- (SWNT-) embedded PDMS thin film, are optically transparent, electrically conductive, and can be mechanically deformed and provide interfaces to form strong covalent bonding between an OET device and PDMS through standard oxygen plasma treatment. Au-mesh ...

  7. Nanofiber spraying method using a supplementary electrode

    Science.gov (United States)

    Kim, GeunHyung; Kim, WanDoo

    2006-07-01

    Using a supplementary electrode, electrospun poly(ɛ-carprolactone) fibers were deposited on various substrates with different electrical properties. The ability to coat the substrates was independent of the surface electric resistance of the substrates. This was due to the charge reduction of the sprayed fibers, which resulted from passing through the supplementary electrode. The sprayed fibers might find applications in smart textiles, advanced coating technology, and as biomedical wound dressings.

  8. Finite element model of needle electrode sensitivity

    Science.gov (United States)

    Høyum, P.; Kalvøy, H.; Martinsen, Ø. G.; Grimnes, S.

    2010-04-01

    We used the Finite Element (FE) Method to estimate the sensitivity of a needle electrode for bioimpedance measurement. This current conducting needle with insulated shaft was inserted in a saline solution and current was measured at the neutral electrode. FE model resistance and reactance were calculated and successfully compared with measurements on a laboratory model. The sensitivity field was described graphically based on these FE simulations.

  9. Charge Transfer in Nanocrystalline Semiconductor Electrodes

    Directory of Open Access Journals (Sweden)

    M. Bouroushian

    2013-01-01

    Full Text Available Nanocrystalline electrodes in liquid junction devices possess a number of unique properties arising from their convoluted structure and the dimensions of their building units. The light-induced charge separation and transport in photoelectrochemical systems using nanocrystalline/nanoporous semiconductor electrodes is discussed here in connection with the basic principles of the (Schottky barrier theory. Recent models for charge transfer kinetics in normal and unipolar (dye-sensitized cells are reviewed, and novel concepts and materials are considered.

  10. Photocatalytic reaction on photofuel cell titania electrode

    OpenAIRE

    Nishikiori, Hiromasa; Kato, Yotaro

    2012-01-01

    Benzoic acid-doped titania electrodes were prepared from titanium alkoxide sols containing benzoic acid in order to examine the photocatalytic reaction of the fuel material concentrated on the titania surface of a photofuel cell electrode. This doping was developed in order to understand the physicochemical processes on the titania rather than to advance the practical use of the photofuel cells. The observed photocurrent and CO(2) and H(2)O productions indicated that the oxidation of the benz...

  11. Electrode porosity and effective electrocatalyst activity in electrode-membrane-assemblies (MEAs) of PEMFCs

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, A.; Wendt, H. [Institut fuer Chemische Technologie, Darmstadt (Germany)

    1996-12-31

    New production technologies of membrane-electrode-assemblies for PEWCs which ensure almost complete catalyst utilization by {open_quotes}wetting{close_quotes} the internal catalyst surface with the ionomeric electrolyte, allow for a reduction of Pt-loadings from prior 4 mg cm{sup -2} to now less than 0.5 mg cm{sup -2}. Such electrodes are not thicker than from 5 to 10 {mu}m. Little has been published hitherto about the detailed micromorphology of such electrodes and the role of electrode porosity on electrode performance. It is well known, that the porosity of thicker fuel cell electrodes, e.g. of PAFC or AFC electrodes is decisive for their performance. Therefore the issue of this investigation is to measure and to modify the porosity of electrodes prepared by typical MEA production procedures and to investigate the influence of this porosity on the effective catalyst activity for cathodic reduction of oxygen from air in membrane cells. It may be anticipated that any mass transfer hindrance of gaseous reactants into porous electrodes would manifest itself rather in the conversion of dilute gases than in the conversion of pure gases (e.g. neat oxygen). Therefore in this investigation the performance of membrane cell cathodes with non pressurized air had been compared to that with neat oxygen at cathodes which had a relatively low Pt-loading of 0.15 mg cm{sup -2}.

  12. 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 high optical transparency.

  13. A multi-electrode biomimetic electrolocation sensor

    Science.gov (United States)

    Mayekar, K.; Damalla, D.; Gottwald, M.; Bousack, H.; von der Emde, G.

    2012-04-01

    We present the concept of an active multi-electrode catheter inspired by the electroreceptive system of the weakly electric fish, Gnathonemus petersii. The skin of this fish exhibits numerous electroreceptor organs which are capable of sensing a self induced electrical field. Our sensor is composed of a sending electrode and sixteen receiving electrodes. The electrical field produced by the sending electrode was measured by the receiving electrodes and objects were detected by the perturbation of the electrical field they induce. The intended application of such a sensor is in coronary diagnostics, in particular in distinguishing various types of plaques, which are major causes of heart attack. For calibration of the sensor system, finite element modeling (FEM) was performed. To validate the model, experimental measurements were carried out with two different systems. The physical system was glass tubing with metal and plastic wall insertions as targets. For the control of the experiment and for data acquisition, the software LabView designed for 17 electrodes was used. Different parameters of the electric images were analyzed for the prediction of the electrical properties and size of the inserted targets in the tube. Comparisons of the voltage modulations predicted from the FEM model and the experiments showed a good correspondence. It can be concluded that this novel biomimetic method can be further developed for detailed investigations of atherosclerotic lesions. Finally, we discuss various design strategies to optimize the output of the sensor using different simulated models to enhance target recognition.

  14. Nanoscale Electrodes for Flexible Electronics by Swelling Controlled Cracking.

    Science.gov (United States)

    Zhao, Qiang; Wang, Wenjun; Shao, Jinyou; Li, Xiangming; Tian, Hongmiao; Liu, Lu; Mei, Xuesong; Ding, Yucheng; Lu, Bingheng

    2016-08-01

    Nanogap electrodes are realized using pre-patterned electrodes and a swelling controlled cracking method. Parallel fabrication of nanogap electrodes on flexible substrates can be achieved using this method. This swelling-controlled cracking method is promising for fabricating high-performance flexible electronics. UV photodetectors with ZnO nanoparticle-bridged nanogap electrodes exhibit high responsivity and external quantum efficiency.

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

    DEFF Research Database (Denmark)

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

    2011-01-01

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

  16. Electrode immersion depth determination and control in electroslag remelting furnace

    Science.gov (United States)

    Melgaard, David K.; Beaman, Joseph J.; Shelmidine, Gregory J.

    2007-02-20

    An apparatus and method for controlling an electroslag remelting furnace comprising adjusting electrode drive speed by an amount proportional to a difference between a metric of electrode immersion and a set point, monitoring impedance or voltage, and calculating the metric of electrode immersion depth based upon a predetermined characterization of electrode immersion depth as a function of impedance or voltage.

  17. Anodes - Materials for negative electrodes in electrochemical energy technology

    Science.gov (United States)

    Holze, Rudolf

    2014-06-01

    The basic concepts of electrodes and electrochemical cells (including both galvanic and electrolytic ones) are introduced and illustrated with practical examples. Particular attention is paid to negative electrodes in primary and secondary cells, fuel cell electrodes and electrodes in redox flow batteries. General features and arguments pertaining to selection, optimization and further development are highlighted.

  18. 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

    As mass-produced, low-cost organic electronics enter our everyday lives, so does the waste from them. The challenges associated with end-of-life management must be addressed by careful design and carbon-based electrodes are central to these developments. Here, the reproducible production of vacuu......-cost plastic solar cells and opens the door to new possible applications where silver recycling is not manageable....

  19. Nanostructured Electrodes Via Electrostatic Spray Deposition for Energy Storage System

    KAUST Repository

    Chen, C.

    2014-10-02

    Energy storage systems such as Li-ion batteries and supercapacitors are extremely important in today’s society, and have been widely used as the energy and power sources for portable electronics, electrical vehicles and hybrid electrical vehicles. A lot of research has focused on improving their performance; however, many crucial challenges need to be addressed to obtain high performance electrode materials for further applications. Recently, the electrostatic spray deposition (ESD) technique has attracted great interest to satisfy the goals. Due to its many advantages, the ESD technique shows promising prospects compared to other conventional deposition techniques. In this paper, our recent research outcomes related to the ESD derived anodes for Li-ion batteries and other applications is summarized and discussed.

  20. Nanomaterial-Enabled Dry Electrodes for Electrophysiological Sensing: A Review

    Science.gov (United States)

    Yao, Shanshan; Zhu, Yong

    2016-04-01

    Long-term, continuous, and unsupervised tracking of physiological data is becoming increasingly attractive for health/wellness monitoring and ailment treatment. Nanomaterials have recently attracted extensive attention as building blocks for flexible/stretchable conductors and are thus promising candidates for electrophysiological electrodes. Here we provide a review on nanomaterial-enabled dry electrodes for electrophysiological sensing, focusing on electrocardiography (ECG). The dry electrodes can be classified into contact surface electrodes, contact-penetrating electrodes, and noncontact capacitive electrodes. Different types of electrodes including their corresponding equivalent electrode-skin interface models and the sources of the noise are first introduced, followed by a review on recent developments of dry ECG electrodes based on various nanomaterials, including metallic nanowires, metallic nanoparticles, carbon nanotubes, and graphene. Their fabrication processes and performances in terms of electrode-skin impedance, signal-to-noise ratio, resistance to motion artifacts, skin compatibility, and long-term stability are discussed.

  1. [Effects of different electrodes on bioelectrical impedance values].

    Science.gov (United States)

    Nakadomo, F; Tanaka, K; Yokoyama, T; Maeda, K

    1990-01-01

    Effects of different electrodes on bioelectrical impedance values measured by the Selco bioelectrical impedance plethysmograph (SIF-881, Japan) were investigated using 8 adult females (age: 35.3 +/- 7.6 yr, Ht: 156.9 +/- 3.8 cm, Wt: 57.1 +/- 9.9 kg, and hydrodensitometrically determined body fat: 29.4 +/- 6.0%). The Lectec MP3000 electrode (Liberty Carton, USA) and the Bipolar electrode (Sanwa, Japan) produced significantly higher impedance values when compared to the Disposable electrode (Adovance, Japan) and the ECG electrode (Nihon Kohden, Japan). The coefficient of variation was significantly lower for the Disposable electrode (0.8%) and the ECG electrode (0.2%) than that for the Lectec MP3000 electrode (2.3%) and the Bipolar electrode (4.9%). In conclusion, the ECG electrode provides higher bioelectrical impedance values with the highest reproducibility in the assessment of human body composition by the bioelectrical impedance plethysmography.

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

    DEFF Research Database (Denmark)

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

    2016-01-01

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

  3. Opening Address [Presented by D. Magliani

    International Nuclear Information System (INIS)

    Full text: I am very pleased to address you this morning on behalf of A.-M. Cetto, Head of the Department of Technical Cooperation, as we open this important international symposium. Interest in the symposium has been very high, with the number of registered participants greatly exceeding the number initially expected. Every region is represented in significant number, particularly Europe. The symposium's aim, to provide a forum to discuss and exchange information on advances over the past decade in radiation dosimetry and its supportive role in radiation medicine and radiation protection, is of high importance to the technical cooperation programme, which has a long standing, well-established focus on health. Accurate measurements in radiation dosimetry are critical in decisions making related to human health and to the safety of radiation workers and the general public, and the focus of this symposium strengthens technical cooperation activities in this sector. In each programme cycle, the IAEA receives large numbers of requests for technical cooperation support in the fields of dosimetry and medical radiation physics. Currently, we have 144 active projects that include these fields of activity. Under the scope of our interregional technical cooperation project on medical physics in radiation medicine (INT/6/054), the IAEA is working with Member States, international physics societies and the World Health Organization to promote the recognition of medical physics in radiation medicine, and to harmonize educational material in order to ensure the safe and effective diagnosis and treatment of patients. We are very pleased to support the attendance of 36 participants at the symposium under this project. Participants can expect to return home with a fresh overview of the latest developments and trends in radiation dosimetry, and a better understanding of the issues. This will contribute to standardization in the field, leading to improved diagnosis and treatment of

  4. Laser Processed Silver Nanowire Network Transparent Electrodes for Novel Electronic Devices

    Science.gov (United States)

    Spechler, Joshua Allen

    Silver nanowire network transparent conducting layers are poised to make headway into a space previously dominated by transparent conducting oxides due to the promise of a flexible, scaleable, lab-atmosphere processable alternative. However, there are many challenges standing in the way between research scale use and consumer technology scale adaptation of this technology. In this thesis we will explore many, and overcome a few of these challenges. We will address the poor conductivity at the narrow nanowire-nanowire junction points in the network by developing a laser based process to weld nanowires together on a microscopic scale. We address the need for a comparative metric for transparent conductors in general, by taking a device level rather than a component level view of these layers. We also address the mechanical, physical, and thermal limitations to the silver nanowire networks by making composites from materials including a colorless polyimide and titania sol-gel. Additionally, we verify our findings by integrating these processes into devices. Studying a hybrid organic/inorganic heterojunction photovoltaic device we show the benefits of a laser processed electrode. Green phosphorescent organic light emitting diodes fabricated on a solution phase processed silver nanowire based electrode show favorable device metrics compared to a conductive oxide electrode based control. The work in this thesis is intended to push the adoption of silver nanowire networks to further allow new device architectures, and thereby new device applications.

  5. Addressing Underrepresentation: Physics Teaching for All

    Science.gov (United States)

    Rifkin, Moses

    2016-02-01

    Every physics teacher wants to give his or her students the opportunity to learn physics well. Despite these intentions, certain groups of students—including women and underrepresented minorities (URMs)—are not taking and not remaining in physics. In many cases, these disturbing trends are more significant in physics than in any other science. This is a missed opportunity for our discipline because demographic diversity strengthens science. The question is what we can do about these trends in our classrooms, as very few physics teachers have been explicitly prepared to address them. In this article, I will share some steps that I've taken in my classroom that have moved my class in the right direction. In the words of Nobel Prize-winning physicist Carl Wieman and psychologists Lauren Aguilar and Gregory Walton: "By investing a small amount of class time in carefully designed and implemented interventions, physics teachers can promote greater success among students from diverse backgrounds. Ultimately, we hope such efforts will indeed improve the diversity and health of the physics profession."

  6. Assessing what to address in science communication

    Science.gov (United States)

    Bruine de Bruin, Wändi; Bostrom, Ann

    2013-01-01

    As members of a democratic society, individuals face complex decisions about whether to support climate change mitigation, vaccinations, genetically modified food, nanotechnology, geoengineering, and so on. To inform people’s decisions and public debate, scientific experts at government agencies, nongovernmental organizations, and other organizations aim to provide understandable and scientifically accurate communication materials. Such communications aim to improve people’s understanding of the decision-relevant issues, and if needed, promote behavior change. Unfortunately, existing communications sometimes fail when scientific experts lack information about what people need to know to make more informed decisions or what wording people use to describe relevant concepts. We provide an introduction for scientific experts about how to use mental models research with intended audience members to inform their communication efforts. Specifically, we describe how to conduct interviews to characterize people’s decision-relevant beliefs or mental models of the topic under consideration, identify gaps and misconceptions in their knowledge, and reveal their preferred wording. We also describe methods for designing follow-up surveys with larger samples to examine the prevalence of beliefs as well as the relationships of beliefs with behaviors. Finally, we discuss how findings from these interviews and surveys can be used to design communications that effectively address gaps and misconceptions in people’s mental models in wording that they understand. We present applications to different scientific domains, showing that this approach leads to communications that improve recipients’ understanding and ability to make informed decisions. PMID:23942122

  7. Presidential address: Experimenting with the scientific past.

    Science.gov (United States)

    Radick, Gregory

    2016-06-01

    When it comes to knowledge about the scientific pasts that might have been - the so-called 'counterfactual' history of science - historians can either debate its possibility or get on with the job. Taking the latter course means re-engaging with some of the most general questions about science. It can also lead to fresh insights into why particular episodes unfolded as they did and not otherwise. Drawing on recent research into the controversy over Mendelism in the early twentieth century, this address reports and reflects on a novel teaching experiment conducted in order to find out what biology and its students might be like now had the controversy gone differently. The results suggest a number of new options: for the collection of evidence about the counterfactual scientific past, for the development of collaborations between historians of science and science educators, for the cultivation of more productive relationships between scientists and their forebears, and for heightened self-awareness about the curiously counterfactual business of being historical. PMID:27353945

  8. Vaccine hesitancy: understanding better to address better.

    Science.gov (United States)

    Kumar, Dewesh; Chandra, Rahul; Mathur, Medha; Samdariya, Saurabh; Kapoor, Neelesh

    2016-01-01

    Vaccine hesitancy is an emerging term in the socio-medical literature which describes an approach to vaccine decision making. It recognizes that there is a continuum between full acceptance and outright refusal of some or all vaccines and challenges the previous understanding of individuals or groups, as being either anti-vaccine or pro-vaccine. The behaviours responsible for vaccine hesitancy can be related to confidence, convenience and complacency. The causes of vaccine hesitancy can be described by the epidemiological triad i.e. the complex interaction of environmental- (i.e. external), agent- (i.e. vaccine) and host (or parent)- specific factors. Vaccine hesitancy is a complex and dynamic issue; future vaccination programs need to reflect and address these context-specific factors in both their design and evaluation. Many experts are of the view that it is best to counter vaccine hesitancy at the population level. They believe that it can be done by introducing more transparency into policy decision-making before immunization programs, providing up-to-date information to the public and health providers about the rigorous procedures undertaken before introduction of new vaccines, and through diversified post-marketing surveillance of vaccine-related events. PMID:26839681

  9. Fully solution-processed transparent electrodes based on silver nanowire composites for perovskite solar cells

    Science.gov (United States)

    Kim, Areum; Lee, Hongseuk; Kwon, Hyeok-Chan; Jung, Hyun Suk; Park, Nam-Gyu; Jeong, Sunho; Moon, Jooho

    2016-03-01

    We report all-solution-processed transparent conductive electrodes based on Ag nanowire (AgNW)-embedded metal oxide composite films for application in organometal halide perovskite solar cells. To address the thermal instability of Ag nanowires, we used combustive sol-gel derived thin films to construct ZnO/ITO/AgNW/ITO composite structures. The resulting composite configuration effectively prevented the AgNWs from undergoing undesirable side-reactions with halogen ions present in the perovskite precursor solutions that significantly deteriorate the optoelectrical properties of Ag nanowires in transparent conductive films. AgNW-based composite electrodes had a transmittance of ~80% at 550 nm and sheet resistance of 18 Ω sq-1. Perovskite solar cells fabricated using a fully solution-processed transparent conductive electrode, Au/spiro-OMeTAD/CH3NH3PbI3 + m-Al2O3/ZnO/ITO/AgNW/ITO, exhibited a power conversion efficiency of 8.44% (comparable to that of the FTO/glass-based counterpart at 10.81%) and were stable for 30 days in ambient air. Our results demonstrate the feasibility of using AgNWs as a transparent bottom electrode in perovskite solar cells produced by a fully printable process.We report all-solution-processed transparent conductive electrodes based on Ag nanowire (AgNW)-embedded metal oxide composite films for application in organometal halide perovskite solar cells. To address the thermal instability of Ag nanowires, we used combustive sol-gel derived thin films to construct ZnO/ITO/AgNW/ITO composite structures. The resulting composite configuration effectively prevented the AgNWs from undergoing undesirable side-reactions with halogen ions present in the perovskite precursor solutions that significantly deteriorate the optoelectrical properties of Ag nanowires in transparent conductive films. AgNW-based composite electrodes had a transmittance of ~80% at 550 nm and sheet resistance of 18 Ω sq-1. Perovskite solar cells fabricated using a fully solution

  10. Monitoring drilling mud composition using flowing liquid junction electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Jasinski, R.; Fletcher, P.; Vercaemer, C.

    1990-06-27

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

  11. A Flat Interface Nerve Electrode With Integrated Multiplexer

    OpenAIRE

    Lertmanorat, Zeng; Montague, F. W; Durand, Dominique M.

    2009-01-01

    One of the goals of peripheral nerve cuff electrode development is the design of an electrode capable of selectively activating a specific population of axons in a common nerve trunk. Several designs such as the round spiral electrode or the flat interface nerve electrode (FINE) have shown such ability. However, multiple contact electrodes require many leads, making the implantation difficult and potentially damaging to the nerve. Taking advantage of the flat geometry of the FINE, multiplexer...

  12. The progress of nanocrystalline hydride electrode materials

    International Nuclear Information System (INIS)

    This paper reviews research at the Institute of Materials Science and Engineering, Poznan University of Technology, on the synthesis of nanocrystalline hydride electrode materials. Nanocrystalline materials have been synthesized by mechanical alloying (MA) followed by annealing. Examples of the materials include TiFe-, ZrV2-, LaNi5 and Mg2Ni-type phases. Details on the process used and the enhancement of properties due to the nanoscale structures are presented. The synthesized alloys were used as negative electrode materials for Ni-MH battery. The properties of hydrogen host materials can be modified substantially by alloying to obtain the desired storage characteristics. For example, it was found that the respective replacement of Fe in TiFe by Ni and/or by Cr, Co, Mo improved not only the discharge capacity but also the cycle life of these electrodes. The hydrogen storage properties of nanocrystalline ZrV2- and LaNi5-type powders prepared by mechanical alloying and annealing show no big difference with those of melt casting (polycrystalline) alloys. On the other hand, a partial substitution of Mg by Mn or Al in Mg2Ni alloy leads to an increase in discharge capacity, at room temperature. Furthermore, the effect of the nickel and graphite coating on the structure of some nanocrystalline alloys and the electrodes characteristics were investigated. In the case of Mg2Ni-type alloy mechanical coating with graphite effectively reduced the degradation rate of the studied electrode materials. The combination of a nanocrystalline TiFe-, ZrV2- and LaNi5-type hydride electrodes and a nickel positive electrode to form a Ni-MH battery, has been successful. (authors)

  13. Use of Refractory Nanoparticles as a Component of Welding Materials in Welding and Surfacing With Coated Electrodes and Flux Cored Wires

    Science.gov (United States)

    Kartsev, D. S.; Zernin, E. A.

    2016-08-01

    The authors address to the issue of mainstream directions and application fields of nanostructured coated electrodes and flux cored wires, their distinctive advantages and shortcomings. Some consideration is given to use of refractory nanoparticles and their influence on the structure and properties of metal when welding and surfacing with flux cored wires and coated electrodes. The results of research carried out in this sphere are analyzed.

  14. Small-angle X-ray scattering at high brilliance european synchrotrons for biotechnology and nano-technology

    Energy Technology Data Exchange (ETDEWEB)

    Svergun, D.; Malfois, M. [EMBL c/o DESY, Hamburg (Germany); Svergun, D. [Institute of Crystallography, Russian Academy of Sciences, Moscow (Russian Federation); Douka, M. [Commission Europeenne, DG III, Bruxelles (Belgium); Riekel, Ch. [European Synchrotron Radiation Facility (ESRF), 38 - Grenoble (France); Perez, J. [Soleil, 91 - Saclay (France); Roessle, M. [European Molecular Biology Laboratory (EMBL), 38 - Grenoble (France); Amenitsch, H. [IBN/Elettra (Germany); Gunter Grossman, J. [Daresbury Synchrotron Radiation Source (SRS) (United Kingdom); Vestergaard, B. [University of Pharmaceutical Sciences, Copenhagen (Denmark); Receveur-Brechot, V. [Centre National de la Recherche Scientifique (CNRS/AFMB), 13 - Marseille (France); Roth, St.V. [Deutsches Elektronen Synchrotron (HASYLAB), Hamburg (Germany); Ferrari, E. [National Institute for the Physics of Matter (CNR-INFM), Trieste (Italy)

    2007-07-01

    Different issues such as micro-fluidic devices for SAXS (small-angle X-ray diffraction), the use of electro-spray and ion trapping for SAXS in the gas phase, the study of flexible and disordered proteins through SAXS, the time-resolved SAXS studies in solution, or the study of nano-structured soft materials, were addressed in this workshop. This document gathers the transparencies of the presentations.

  15. Small-angle X-ray scattering at high brilliance european synchrotrons for biotechnology and nano-technology

    International Nuclear Information System (INIS)

    Different issues such as micro-fluidic devices for SAXS (small-angle X-ray diffraction), the use of electro-spray and ion trapping for SAXS in the gas phase, the study of flexible and disordered proteins through SAXS, the time-resolved SAXS studies in solution, or the study of nano-structured soft materials, were addressed in this workshop. This document gathers the transparencies of the presentations

  16. Aspects of Metal-YSZ Electrode Kinetics Studied using Model Electrodes

    DEFF Research Database (Denmark)

    Graves, Christopher R.; Ebbesen, Sune; Mogensen, Mogens Bjerg

    2009-01-01

    The electrode kinetics of oxidation and reduction of H2/H2O and CO/CO2 at the metal/yttria stabilized zirconia (YSZ) interface were studied using model metal wire electrodes contacting polished YSZ pellets. The intent was to probe the reaction mechanisms by comparing the same reactions using...

  17. Voltammetric Response of Epinephrine at Carbon Nanotube Modified Glassy Carbon Electrode and Activated Glassy Carbon Electrode

    Institute of Scientific and Technical Information of China (English)

    WANG Juan; TANG Ping; ZHAO Fa-qiong; ZENG Bai-zhao

    2005-01-01

    The electrochemical behavior of epinephrine at activated glassy carbon electrode and carbon nanotube-coated glassy carbon electrode was studied. Epinephrine could exhibit an anodic peak at about 0.2 V (vs. SCE) at bare glassy carbon electrode, but it was very small.However, when the electrode was activated at certain potential (i. e. 1.9V) or modified with carbon nanotube, the peak became more sensitive,resulting from the increase in electrode area in addition to the electrostatic attraction. Under the selected conditions, the anodic peak current was linear to epinephrine concentration in the range of 3.3 × 10-7-1.1 × 10-5mol/L at activated glassy carbon electrode and in the range of 1.0 × 10-6-5.0 × 10-5 mol/L at carbon nanotube-coated electrode. The correlation coefficients were 0. 998 and 0. 997, respectively. The determination limit was 1.0 × 10-7 mol/L. The two electrodes have been successfully applied for the determination of epinephrine in adrenaline hydrochloride injection with recovery of 95%-104%.

  18. Computational strategies to address chromatin structure problems

    Science.gov (United States)

    Perišić, Ognjen; Schlick, Tamar

    2016-06-01

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

  19. USGS Science: Addressing Our Nation's Challenges

    Science.gov (United States)

    Larson, Tania M.

    2009-01-01

    With 6.6 billion people already living on Earth, and that number increasing every day, human influence on our planet is ever more apparent. Changes to the natural world combined with increasing human demands threaten our health and safety, our national security, our economy, and our quality of life. As a planet and a Nation, we face unprecedented challenges: loss of critical and unique ecosystems, the effects of climate change, increasing demand for limited energy and mineral resources, increasing vulnerability to natural hazards, the effects of emerging diseases on wildlife and human health, and growing needs for clean water. The time to respond to these challenges is now, but policymakers and decisionmakers face difficult choices. With competing priorities to balance, and potentially serious - perhaps irreversible - consequences at stake, our leaders need reliable scientific information to guide their decisions. As the Nation's earth and natural science agency, the USGS monitors and conducts scientific research on natural hazards and resources and how these elements and human activities influence our environment. Because the challenges we face are complex, the science needed to better understand and deal with these challenges must reflect the complex interplay among natural and human systems. With world-class expertise in biology, geology, geography, hydrology, geospatial information, and remote sensing, the USGS is uniquely capable of conducting the comprehensive scientific research needed to better understand the interdependent interactions of Earth's systems. Every day, the USGS helps decisionmakers to minimize loss of life and property, manage our natural resources, and protect and enhance our quality of life. This brochure provides examples of the challenges we face and how USGS science helps decisionmakers to address these challenges.

  20. International partnership in lunar missions: Inaugural address

    Indian Academy of Sciences (India)

    Dr A P J Abdul Kalam

    2005-12-01

    I am delighted to participate in the 6th International Conference on Exploration and Utilization of the Moon organized by the Physical Research Laboratory,Ahmedabad.I greet the organizers, eminent planetary exploration and space scientists from India and abroad,academicians,industrialists,engineers,entrepreneurs and distinguished guests.I understand that the International Lunar Conference is a forum to discuss scienti fic results of the ongoing and future space missions related to lunar exploration.This conference will also be utilized to develop understanding on various strategies,initiatives and missions leading to a permanent human presence on our Moon as the future objective.I am happy to note that interactions that took place in the earlier conferences have been bene ficial to participating countries through the intense sharing of scientific knowledge,data and hands-on mission experiences of various space agencies pursuing lunar exploration programmes.I find that nearly 100 scientific papers are being presented in this conference and that the Moon missions being planned and conducted by all the space faring nations of the world are being presented,reviewed and discussed.I note with excitement that many key issues related to space science and Moon missions are being addressed in this conference.These deliberations are important for the world space science community.This will enable you to obtain a comprehensive picture of the goals and policies of all nations striving towards a common vision of space research,being made available for the bene fit of all mankind.Indeed this augurs well for progress towards universal peace and harmony that is a cherished goal of the people of the world as a whole.

  1. Computational strategies to address chromatin structure problems.

    Science.gov (United States)

    Perišić, Ognjen; Schlick, Tamar

    2016-01-01

    While the genetic information is contained in double helical DNA, gene expression is a complex multilevel process that involves various functional units, from nucleosomes to fully formed chromatin fibers accompanied by a host of various chromatin binding enzymes. The chromatin fiber is a polymer composed of histone protein complexes upon which DNA wraps, like yarn upon many spools. The nature of chromatin structure has been an open question since the beginning of modern molecular biology. Many experiments have shown that the chromatin fiber is a highly dynamic entity with pronounced structural diversity that includes properties of idealized zig-zag and solenoid models, as well as other motifs. This diversity can produce a high packing ratio and thus inhibit access to a majority of the wound DNA. Despite much research, chromatin's dynamic structure has not yet been fully described. Long stretches of chromatin fibers exhibit puzzling dynamic behavior that requires interpretation in the light of gene expression patterns in various tissue and organisms. The properties of chromatin fiber can be investigated with experimental techniques, like in vitro biochemistry, in vivo imagining, and high-throughput chromosome capture technology. Those techniques provide useful insights into the fiber's structure and dynamics, but they are limited in resolution and scope, especially regarding compact fibers and chromosomes in the cellular milieu. Complementary but specialized modeling techniques are needed to handle large floppy polymers such as the chromatin fiber. In this review, we discuss current approaches in the chromatin structure field with an emphasis on modeling, such as molecular dynamics and coarse-grained computational approaches. Combinations of these computational techniques complement experiments and address many relevant biological problems, as we will illustrate with special focus on epigenetic modulation of chromatin structure. PMID:27345617

  2. Sampled voltammetry on an electrode array for the renewal of the electrode surface and the analytical solution during the analysis

    OpenAIRE

    Mignard, Laurence; Denoual, Matthieu; Lavastre, Olivier; Floner, Didier; Geneste, Florence

    2013-01-01

    Polarography with dropping mercury electrode has been widely used in electroanalysis. However, the method is less and less employed due to the toxicity of mercury. In this work, we have shown that it is possible to replace the dropping electrode by a working electrode array, allowing the renewal of the electrode surface and of the analytical solution during the analysis. This new concept has been demonstrated on copper analysis. Sampled current voltammetry has been carried out on an electrode...

  3. 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.

  4. Nanowire Electrodes for Advanced Lithium Batteries

    Directory of Open Access Journals (Sweden)

    Lei eHuang

    2014-10-01

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

  5. 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.

  6. The new candidate IPV6 address size prediction

    Directory of Open Access Journals (Sweden)

    Khaldoun Batiha

    2014-01-01

    Full Text Available IPv4 protocol is now no more sufficient due to its limited address space where this protocol uses only 32-bit for addressing. IPv6 protocol is the next protocol which was introduced as a new protocol that provide a huge address space .In This paper we discussed the significant overhead in the IPv6 standard packet due to its 128 bits address size, so we develop three different studies in order to generate a prediction of exhibition date for several address sizes so we can suggest another size for address size in IPv6 to improve the overall performance of the internet and tolerate the overhead by reducing the address size. In the same time this size should accommodate the accelerated growth in needs for unassigned blocks of addresses for very long time.   Keywords: Ipv4 Protocol, Ipv6 Protocol, Addressing Types, Ipv6 Header, Exhibition Date, Address Pool.

  7. Multi Sensor Approach to Address Sustainable Development

    Science.gov (United States)

    Habib, Shahid

    2007-01-01

    The main objectives of Earth Science research are many folds: to understand how does this planet operates, can we model her operation and eventually develop the capability to predict such changes. However, the underlying goals of this work are to eventually serve the humanity in providing societal benefits. This requires continuous, and detailed observations from many sources in situ, airborne and space. By and large, the space observations are the way to comprehend the global phenomena across continental boundaries and provide credible boundary conditions for the mesoscale studies. This requires a multiple sensors, look angles and measurements over the same spot in accurately solving many problems that may be related to air quality, multi hazard disasters, public health, hydrology and more. Therefore, there are many ways to address these issues and develop joint implementation, data sharing and operating strategies for the benefit of the world community. This is because for large geographical areas or regions and a diverse population, some sound observations, scientific facts and analytical models must support the decision making. This is crucial for the sustainability of vital resources of the world and at the same time to protect the inhabitants, endangered species and the ecology. Needless to say, there is no single sensor, which can answer all such questions effectively. Due to multi sensor approach, it puts a tremendous burden on any single implementing entity in terms of information, knowledge, budget, technology readiness and computational power. And, more importantly, the health of planet Earth and its ability to sustain life is not governed by a single country, but in reality, is everyone's business on this planet. Therefore, with this notion, it is becoming an impractical problem by any single organization/country to bear this colossal responsibility. So far, each developed country within their means has proceeded along satisfactorily in implementing

  8. Addressing contrasting cognitive models in scientific collaboration

    Science.gov (United States)

    Diviacco, P.

    2012-04-01

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

  9. Evaluating Judicial Performance and Addressing Gender Bias

    Directory of Open Access Journals (Sweden)

    Angela Melville

    2014-12-01

    Full Text Available Elek and Rottman argue that judicial evaluation is often biased against women and minority judges. The need to address bias is important, however often the desire for diversity seems so self-evident as to belie deeper analysis. This paper examines the two main rationales for gender equality on the bench. First, female judges are often considered necessary in order to bring a gendered perspective to judging, however it is argued that this rationale is flawed. Second, an alternative rationale based on equality and legitimacy is offered which avoids gender essentialism. While debates typically focus on these two rationales, a third rationale embraces both difference and equality/legitimacy. The presence of female judges has an important symbolic value which destabilises existing fraternal legal norms. Finally, increasing the number of female judges may not necessarily change judging, and this paper also analyses how the transformative potential offered by judicial diversity can work in practice. Elek y Rottman defienden que la evaluación judicial suele estar sesgada en contra de las mujeres y los jueces pertenecientes a minorías. La necesidad de abordar el sesgo es importante, sin embargo a menudo el deseo de diversidad parece tan evidente como para contradecir un análisis más profundo. Este artículo examina los dos motivos principales para la igualdad de género en el banquillo. En primer lugar, las mujeres jueces a menudo se consideran necesarias para aportar una perspectiva de género al hecho de juzgar, sin embargo, se defiende que este razonamiento es erróneo. En segundo lugar, se ofrece una alternativa lógica basada en la igualdad y la legitimidad que evita el esencialismo de género. Mientras que los debates suelen centrarse en estas dos razones, una tercera justificación abarca tanto la diferencia como la igualdad/legitimidad. La presencia de mujeres en la judicatura tiene un importante valor simbólico que desestabiliza las normas

  10. Moving to world's best uranium address

    International Nuclear Information System (INIS)

    Most exploration dollars spent in South Australia are focused on exploiting uranium. This is for good reason as South Australia is the world's best address for uranium. Pressure to cut CO2 emissions and the ballistic growth of the Chinese and Indian economies has heightened expectations that the worldwide use of uranium for power generation will mushroom beyond its current 17% market share. The recent Australia-China deal only seems to confirm this; hence uranium's growing popularity among miners and explorers. Such is the attractiveness of uranium-related floats, when Toro Energy sought $18m in March it was swamped with more than three times share application volume. In the north west, Southern Gold and Hindmarsh Resources are expectantly drilling for commercial uranium deposits all around the acreage that hosts the Challenger gold mine in the Gawler Craton. The first exploration drilling for uranium in quaternary-age river channels will take place in South Australia's far north in May. Red Metal says while older and deeper tertiary river channels in the area that host the Beverley uranium mine were explored for uranium, the younger near-surface channel has not had a single hole drilled for uranium. This is despite the area being one of the 'hottest radiogenic terrains in South Australia'. The company will target calcrete-style uranium mineralisation similar to the Yerrlirrie deposit in Western Australia (52,000t U308). Tasman Resources will start drilling to test seven uranium targets within 30km of Olympic Dam, the world's largest known uranium deposit, later this year. Tasman also holds tenements adjoining the Warrior uranium deposit near Tarcoola that contains known radiometric anomalies within the 40km-long Wynbring paleochannels. They are the fourth largest uranium explorer in South Australia. Alliance Resources and its JV partner Quasar Resources are exploring the Beverley 4 Mile uranium prospect at Arkaroola. Quasar is an affiliate of Heathgate Resources

  11. Temporal and Spatial Classification of Active IPv6 Addresses

    OpenAIRE

    Plonka, David; Berger, Arthur

    2015-01-01

    There is striking volume of World-Wide Web activity on IPv6 today. In early 2015, one large Content Distribution Network handles 50 billion IPv6 requests per day from hundreds of millions of IPv6 client addresses; billions of unique client addresses are observed per month. Address counts, however, obscure the number of hosts with IPv6 connectivity to the global Internet. There are numerous address assignment and subnetting options in use; privacy addresses and dynamic subnet pools significant...

  12. A novel three-electrode solid electrolyte hydrogen gas sensor

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Min; Yang, Chunling; Zhang, Yan [Harbin Insitute of Technology, Harbin (China). School of Computer Science and Technology; Jia, Zheng [Harbin Insitute of Technology, Harbin (China). School of Chemical Engineering and Technology

    2013-07-01

    A three-electrode solid electrolyte hydrogen gas sensor is explored in this paper. The sensor utilized phosphotungstic acid as the electrolyte material and adopted platinum, nickel and tungsten as the three-electrode materials respectively. In real applications, platinum was used as the measuring electrode, nickel was used as the adjusting electrode and tungsten was used as the reference electrode. In order to compare the performance of the new sensor with that of the traditional two-electrode sensor, the hydrogen concentrations were adjusted so as to detect the output of the two-electrode sensor and the three-electrode sensor. The dynamic range between the measuring electrode and the reference electrode is about 0.65V and the highest detectable limit is 12% for the three-electrode solid hydrogen gas sensor. While the dynamic range is about 0.25V and and the highest detectable limit is 1% for the two-electrode solid electrolyte gas sensor. The results demonstrate that the three-electrode solid hydrogen gas sensor has a higher resolution and detectable limit than the two-electrode sensor. abstract environment.

  13. SiBCN-CNT/Graphene Paper Electrode

    Science.gov (United States)

    David, Lamuel; Singh, Gurpreet

    2014-03-01

    We demonstrate synthesis and electrochemical performance of novel molecular precursor-derived ceramic (PDC)/carbon nanotube embedded graphene self-supporting composite papers as Li-ion battery electrode. The papers were prepared through vacuum filtration of various PDC-graphene oxide (GO) dispersions in DI water followed by thermal reduction at elevated temperatures that resulted in a homogenous PDC/reduced GO papers that were highly crumpled, mechanically robust and consisted of a 3-D electrically conducting network. These electrodes showed electrochemical capacities as much as approx. 300 mAh.g-1 with respect to total weight of the electrode (approx. 500 mAh.g-1 w.r.t. active material), with negligible capacity loss for more than 1000 cycles. Boron-doped silicon carbon nitride (Si(B)CN/graphene) outperformed its un-doped counterparts (SiCN/graphene), both in terms of electrochemical capacity, cycling stability and coulombic efficiency.

  14. Capacitor with a composite carbon foam electrode

    Energy Technology Data Exchange (ETDEWEB)

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

    1999-04-27

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

  15. Capacitor with a composite carbon foam electrode

    Energy Technology Data Exchange (ETDEWEB)

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

    1999-01-01

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

  16. Hydrogen electrode reaction: A complete kinetic description

    Energy Technology Data Exchange (ETDEWEB)

    Quaino, P.M. [Programa de Electroquimica Aplicada e Ingenieria Electroquimica (PRELINE), Facultad de Ingenieria Quimica, Universidad Nacional del Litoral, Santiago del Estero 2829, 3000 Santa Fe (Argentina); Gennero de Chialvo, M.R. [Programa de Electroquimica Aplicada e Ingenieria Electroquimica (PRELINE), Facultad de Ingenieria Quimica, Universidad Nacional del Litoral, Santiago del Estero 2829, 3000 Santa Fe (Argentina); Chialvo, A.C. [Programa de Electroquimica Aplicada e Ingenieria Electroquimica (PRELINE), Facultad de Ingenieria Quimica, Universidad Nacional del Litoral, Santiago del Estero 2829, 3000 Santa Fe (Argentina)]. E-mail: achialvo@fiqus.unl.edu.ar

    2007-09-15

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

  17. AC Dielectrophoresis Using Elliptic Electrode Geometry

    Directory of Open Access Journals (Sweden)

    S. M. Rezaul Hasan

    2011-01-01

    Full Text Available This paper presents negative AC dielectrophoretic investigations using elliptic electrode geometry. Simulations of the electric field gradient variation using various ratios of the semimajor and the semiminor axis were carried out to determine the optimum elliptic geometry for the dielectrophoretic electrokinetics of specimen in an assay with laminar (low Reynolds number fluid flow. Experimental setup of the elliptic electrode assembly using PCB fabrication and electrokinetic accumulation of specimen in a dielectrophoretic cage is also being reported. Using an actuating signal between 1 kHz and 1 MHz, successful trapping of 45 μm polystyrene beads suspended in distilled water was demonstrated due to negative dielectrophoresis near 100 kHz using the novel elliptic electrode.

  18. Adsorption on smooth electrodes: A radiotracer study

    International Nuclear Information System (INIS)

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

  19. Insulated electrocardiographic electrodes. [without paste electrolyte

    Science.gov (United States)

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

    1975-01-01

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

  20. Electrode reactions and electroanalysis of organomercury compounds

    Energy Technology Data Exchange (ETDEWEB)

    Kurmaz, Vladimir A [Institute of Problems of Chemical Physics, Russian Academy of Sciences, Chernogolovka, Moscow Region (Russian Federation); Gul' tyai, Vadim P [N.D.Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Moscow (Russian Federation)

    2010-06-09

    Characteristic features of mechanisms and kinetics of electrode reactions of organomercury compounds (symmetrical, non-symmetrical) and organomercury salts on a mercury electrode are analyzed. Attention is focused on the effect of coordination, adsorption and the nature and properties of intermediates on these processes as well as on the formation of organomercury derivatives in the adsorption of organic and hetero-organic compounds on a mercury electrode. The kinetics of heterogeneous chemical equilibrium {sup o}rganic calomel{sup -}symmetrical organomercury compound in the adsorption layer and the relative stability of intermediates in the one-electron reduction of organomercury salts are discussed as well as the electrolytic hydrogen evolution catalyzed by organomercury intermediates. The problems of combined and separate electrochemical quantitation of organic and inorganic mercury compounds in natural objects are considered.

  1. Interdigitated ring electrodes: Theory and experiment

    CERN Document Server

    Barnes, Edward O; Pozo-Ayuso, Diego F; Castaño-Alvarez, Mario; Lewis, Grace E M; Dale, Sara E C; Marken, Frank; Compton, Richard G

    2013-01-01

    The oxidation of potassium ferrocyanide, K_4Fe(CN)_6, in aqueous solution under fully supported conditions is carried out at interdigitated band and ring electrode arrays, and compared to theoretical models developed to simulate the processes. Simulated data is found to fit well with experimental results using literature values of diffusion coefficients for Fe(CN)_6^(4-) and Fe(CN)_6^(3-). The theoretical models are used to compare responses from interdigitated band and ring arrays, and the size of ring array required to approximate the response to a linear band array is investigated. An equation is developed for the radius of ring required for a pair of electrodes in a ring array to give a result with 5% of a pair of electrodes in a band array. This equation is found to be independent of the scan rate used over six orders of magnitude.

  2. Electroanalytical detection of pindolol: comparison of unmodified and reduced graphene oxide modified screen-printed graphite electrodes.

    Science.gov (United States)

    Cumba, Loanda R; Smith, Jamie P; Brownson, Dale A C; Iniesta, Jesús; Metters, Jonathan P; do Carmo, Devaney R; Banks, Craig E

    2015-03-01

    Recent work has reported the first electroanalytical detection of pindolol using reduced graphene oxide (RGO) modified glassy carbon electrodes [S. Smarzewska and W. Ciesielski, Anal. Methods, 2014, 6, 5038] where it was reported that the use of RGO provided significant improvements in the electroanalytical signal in comparison to a bare (unmodified) glassy carbon electrode. We demonstrate, for the first time, that the electroanalytical quantification of pindolol is actually possible using bare (unmodified) screen-printed graphite electrodes (SPEs). This paper addresses the electroanalytical determination of pindolol utilising RGO modified SPEs. Surprisingly, it is found that bare (unmodified) SPEs provide superior electrochemical signatures over that of RGO modified SPEs. Consequently the electroanalytical sensing of pindolol is explored at bare unmodified SPEs where a linear range between 0.1 μM-10.0 μM is found to be possible whilst offering a limit of detection (3σ) corresponding to 0.097 μM. This provides a convenient yet analytically sensitive method for sensing pindolol. The optimised electroanalytical protocol using the unmodified SPEs, which requires no pre-treatment (electrode polishing) or electrode modification step (such as with the use of RGO), was then further applied to the determination of pindolol in urine samples. This work demonstrates that the use of RGO modified SPEs have no significant benefits when compared to the bare (unmodified) alternative and that the RGO free electrode surface can provide electro-analytically useful performances.

  3. System of fabricating a flexible electrode array

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-10-12

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

  4. System of fabricating a flexible electrode array

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-01-28

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

  5. Ion selective electrodes in environmental analysis

    Directory of Open Access Journals (Sweden)

    Radu Aleksandar

    2013-01-01

    Full Text Available An overview is given dealing with application of ion-selective electrodes (ISEs in environmental analysis. ISEs are placed into the context of the trend of development of sensors for extensive and frequent monitoring. Discussed are the issues such as sensing platforms and their mass-production, improvement of precision, diagnostic of sensor’s functionality, and development of reference electrodes and several examples of real-life application of ISEs in environmental analysis are given. The main emphasis of this article is directed towards summarizing recent of authors’ results during the past several years.

  6. Low-frequency noise at semiconductor electrodes

    International Nuclear Information System (INIS)

    It is shown that modulation of electrode accessible surface is the main cause for low-frequency noise under ilumination of InP-GaAs- and CdSe electrodes in solutions containing KCl and S2-/Sn2- and Fe(CN)3-6/Fe(Cn)4-6 redox systems due to photocorrosion process and build up of the products of photoelectrochemical reactions, shot noise coefficient value γ=1 is derived for InP mode oxidation which points to the absence of correlated transfer of electrons in the reaction

  7. Template-directed porous electrodes in electroanalysis.

    Science.gov (United States)

    Walcarius, Alain

    2010-01-01

    Nano- and/or macrostructuring of electrode surfaces has recently emerged as a powerful method of improving the performances of electrochemical devices by enhancing both molecular accessibility and rapid mass transport via diffusion, by increasing the electroactive surface area in comparison to the geometric one, and/or by providing confinement platforms for hosting suitable reagents. This brief overview highlights how template technology offers advantages in terms of designing new types of porous electrodes-mostly based on thin films, and functionalized or not-and discusses their use in analytical chemistry via some recent examples from the literature on electrochemical sensors and biosensors.

  8. Atmospheric Pressure Glow Discharge with Liquid Electrode

    Science.gov (United States)

    Tochikubo, Fumiyoshi

    2013-09-01

    Nonthermal atmospheric pressure plasmas in contact with liquid are widely studied aiming variety of plasma applications. DC glow discharge with liquid electrode is an easy method to obtain simple and stable plasma-liquid interface. When we focus attention on liquid-phase reaction, the discharge system is considered as electrolysis with plasma electrode. The plasma electrode will supply electrons and positive ions to the liquid surface in a different way from the conventional metal electrode. However, the phenomena at plasma-liquid interface have not been understood well. In this work, we studied physical and chemical effect in liquid induced by dc atmospheric pressure glow discharge with liquid electrode. The experiment was carried out using H-shaped Hoffman electrolysis apparatus filled with electrolyte, to separate the anodic and cathodic reactions. Two nozzle electrodes made of stainless steel are set about 2 mm above the liquid surface. By applying a dc voltage between the nozzle electrodes, dc glow discharges as plasma electrodes are generated in contact with liquid. As electrolyte, we used aqueous solutions of NaCl, Na2SO4, AgNO3 and HAuCl4. AgNO3 and HAuCl4 are to discuss the reduction process of metal ions for synthesis of nanoparticles (NPs). OH radical generation yield in liquid was measured by chemical probe method using terephthalic acid. Discharge-induced liquid flow was visualized by Schlieren method. Electron irradiation to liquid surface (plasma cathode) generated OH- and OH radical in liquid while positive ion irradiation (plasma anode) generated H+ and OH radical. The generation efficiency of OH radical was better with plasma anode. Both Ag NPs in AgNO3 and Au NPs in HAuCl4 were synthesized with plasma cathode while only Au NPs were generated with plasma anode. Possible reaction process is qualitatively discussed. The discharge-induced liquid flow such as convection pattern was strongly influenced by the gas flow on the liquid surface. This work

  9. Hollow electrode loose plate SOFC design

    Energy Technology Data Exchange (ETDEWEB)

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

    1995-12-31

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

  10. A method for making Mn02 electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Ikeda, M.; Nisino, A.

    1983-03-30

    A layer of Mn02, produced during thermal breakdown of manganese salts, is applied to a metallic current outlead. Then a mixture of granulated Mn02 and an electricity conducting additive and a binder is applied to this layer. The electrode contains 1 to 5 percent by mass epoxide resin, 5 to 15 percent by mass carbon powder, 0.1 to 10 percent by mass beta-Mn02 and 70 to 90 percent by mass gamma-Mn02. The electrode has high mechanical strength and good discharge characteristics.

  11. Flexible electrode array for artifical vision

    Science.gov (United States)

    Krulevitch, Peter; Polla, Dennis L.; Maghribi, Mariam N.; Hamilton, Julie

    2006-12-05

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

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

    OpenAIRE

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

    1987-01-01

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

  13. Performance and cycle life of carbon- and conductive-based air electrodes for rechargeable Zn-air battery applications

    Science.gov (United States)

    Chellapandi Velraj, Samgopiraj

    The development of high-performance, cyclically stable bifunctional air electrodes are critical to the commercial deployment of rechargeable Zn-air batteries. The carbon material predominantly used as support material in the air electrodes due to its higher surface area and good electrical conductivity suffers from corrosion at high oxygen evolution overpotentials. This study addresses the carbon corrosion issues and suggests alternate materials to replace the carbon as support in the air electrode. In this study, Sm0.5Sr0.5CoO3-delta with good electrochemical performance and cyclic lifetime was identified as an alternative catalyst material to the commonly used La0.4Ca 0.6CoO3 catalyst for the carbon-based bifunctional electrodes. Also, a comprehensive study on the effects of catalyst morphology, testing conditions on the cycle life as well as the relevant degradation mechanism for the carbon-based electrode was conducted in this dissertation. The cyclic life of the carbon-based electrodes was strongly dependent on the carbon support material, while the degradation mechanisms were entirely controlled by the catalyst particle size/morphology. Some testing conditions like resting time and electrolyte concentration did not change the cyclic life or degradation mechanism of the carbon-based electrode. The current density used for cyclic testing was found to dictate the degradation mechanism leading to the electrode failure. An alternate way to circumvent the carbon corrosion is to replace the carbon support with a suitable electrically-conductive ceramic material. In this dissertation, LaNi0.9Mn0.1O3, LaNi 0.8Co0.2O3, and NiCo2O4 were synthesized and evaluated as prospective support materials due to their good electrical conductivity and their ability to act as the catalyst needed for the bifunctional electrode. The carbon-free electrodes had remarkably higher catalytic activity for oxygen evolution reaction (OER) when compared to the carbon-based electrode. However

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

    Science.gov (United States)

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

    2015-03-01

    Flow electrode deionization (FCDI) is an emerging area for continuous and scalable deionization, but the electrochemical and flow properties of the flow electrode need to be improved to minimize energy consumption. Chemical oxidation of granular activated carbon (AC) was examined here to study the role of surface heteroatoms on rheology and electrochemical performance of a flow electrode (carbon slurry) for deionization processes. Moreover, it was demonstrated that higher mass densities could be used without increasing energy for pumping when using oxidized active material. High mass-loaded flow electrodes (28% carbon content) based on oxidized AC displayed similar viscosities (∼21 Pa s) to lower mass-loaded flow electrodes (20% carbon content) based on nonoxidized AC. The 40% increased mass loading (from 20% to 28%) resulted in a 25% increase in flow electrode gravimetric capacitance (from 65 to 83 F g(-1)) without sacrificing flowability (viscosity). The electrical energy required to remove ∼18% of the ions (desalt) from of the feed solution was observed to be significantly dependent on the mass loading and decreased (∼60%) from 92 ± 7 to 28 ± 2.7 J with increased mass densities from 5 to 23 wt %. It is shown that the surface chemistry of the active material in a flow electrode effects the electrical and pumping energy requirements of a FCDI system. PMID:25633260

  15. Research on the Mo del of a Lightweight Resource Addressing

    Institute of Scientific and Technical Information of China (English)

    LUO Bingqing; SUN Zhixin

    2015-01-01

    This paper discussed the characteristics of addressing from the perspective of Internet address-ing mechanism. An Internet of things (IOT) resource ad-dressing iteration model was defined. In the model, a di-rect addressing mode for active nodes and an indirect addressing mode for passive codes were proposed, which meet the requirement for multiple encoding mode. A uni-fied IOT resource lightweight addressing scheme based on IPv6 has been proposed to implement the two addressing modes. The scheme utilized the virtual domain to solve the problem of the heterogeneous encoding. The paper imple-mented the addressing process from the Internet host to the sensor node based on IPv6 over low-power wireless personal area networks (6LoWPAN) protocol. The experi-ment results show that the scheme is performed to realize communication between wireless sensor networks and IPv6 networks.

  16. Microtitrimetry by differential electrolytic potentiometry using metallic electrodes and nanomaterials modified metallic electrodes

    Science.gov (United States)

    Amro, Abdulaziz Nabil

    For the first time silver wire electrodes have been coated with carbon nanotubes using floating catalyst chemical vapor deposition (CVD) method. The production of CNTs has been conducted in a horizontal tubular reactor. Acetylene gas was used as a carbon source. Ferrocene has been used as a catalyst precursor for the growth of CNT. Different parameters have been optimized to get a high yield of CNTs and ensure their growth on the silver electrodes using univariate method. The parameters studied include the hydrogen flow rate, acetylene flow rate, temperature of the furnace, time of the reaction and the location of the electrodes in the reactor tube. The optimum conditions for those parameters were: for hydrogen and acetylene, the flow rates were 25 mL /min and 75 mL / min respectively. The furnace temperature was found to be 700 °C and the reaction time was 15 minutes. Regarding the location of the silver wires it should be located in the first 10 cm of the front side of the tube. Scanning electron microscopy (SEM) and transition electron microscopy (TEM) have been used to characterize carbon on silver electrodes. According to the experimental results, TEM figures show that CNT produced on Silver wire is multiwall carbon nanotubes MWCNT. Silver electrodes either pure or coated with CNT were used as indicating systems in micro titration using both dc differential electrolytic potentiometry (DEP) and mark-space bias DEP techniques. All types of titrimetric reactions were investigated using different types of electrodes like Pt and gold for oxidation reduction titrations, antimony electrodes for acid base titrations, silver electrodes for precipitation titrations in addition to Ag-CNT electrodes. End points at volumes of 1 microL were determined. Different parameters were optimized like the current density, the percentage bias, the volume of the sample and the concentrations of the reactants. Microtitrimetry has been applied on several types of analytes; Ferrous

  17. Micro-agar salt bridge in patch-clamp electrode holder stabilizes electrode potentials

    OpenAIRE

    Shao, Xuesi M; Feldman, Jack L.

    2006-01-01

    Maintaining a stable electrode potential is critical for patch-clamp measurements. The electrode potential of conventional patch electrode-holder assembly, where an Ag/AgCl wire is in direct contact with the patch pipette filling solution, is subject to drift if the pipette solution contains a low concentration of chloride ions (Cl−). We developed an agar bridge of 3 M KCl filled in a polyimide microtubing which forms an electrical connection between an Ag/AgCl wire and the pipette solution. ...

  18. Opening Address: Japan's Nuclear Reactor Strategy

    International Nuclear Information System (INIS)

    Thank you very much Mr. Chairman for your kind introduction. Distinguished colleagues, ladies and gentlemen, it is a great pleasure for me to have the chance to address you here in Kyoto at this 'International Conference on Fast Reactors and Related Fuel Cycles (FR09)'. At the outset, I would like to thank the IAEA for organizing this conference and, taking this opportunity, I would like to assure its new Director General, Y. Amano, of Japan's continuing support for the IAEA. I am looking forward to continuing to work with the IAEA in order to extend the benefits of the peaceful uses of nuclear energy and science and technology to a global population. We are witnessing today a global emergence of interest in the construction of nuclear power plants. There are a number of reasons for this. Major factors are the urgent and ever growing need for energy, particularly in the developing world, fluctuations in fossil fuel prices, the pursuit of security of energy supply and the growing recognition of the need to combat global warming. Despite the global economic crisis, the IAEA's latest projections continue to show a significant increase in nuclear generating capacity in the medium term. The low projection for 2030 is now 511 GW(e) of generating capacity, compared with 370 GW(e) today. The high projection is 807 GW(e); more than a doubling of present levels. Most of the 30 countries that already use nuclear power plan to expand their output. Growth targets have been raised significantly in China, India and the Russian Federation. In addition, according to the IAEA, some 50 countries - mostly in the developing world - have informed the IAEA that they might be interested in launching nuclear power programmes and 12 of these are actively considering nuclear power. Even in the high case projection, however, nuclear power's share of global power generation will go down from the current 16% level to 14% by 2030 and then rise to 22% by 2050, according to the projection

  19. Opening Address: Meeting Tomorrow's Energy Needs

    International Nuclear Information System (INIS)

    I want to thank the IAEA, as well as the international and local organizing committees, for assembling this impressive group of conference attendees to share information and exchange ideas this week. I am honoured to be a part of this distinguished panel. I also want to thank our Japanese colleagues for their wonderful hospitality and for selecting the beautiful city of Kyoto as the venue. This is an historic time of challenge and opportunity. President Obama is seeking to accelerate our nation's transformation to a low carbon economy. He has set a goal of reducing carbon emissions by 80 per cent by 2050. As we meet here in Kyoto, the site of another historic climate change discussion, President Obama is preparing to attend the United Nations Climate Change Conference in Copenhagen, continuing his Administration's commitment to tackling climate change and building a clean energy economy. Four months ago, Dr. Warren 'Pete' Miller was confirmed by the United States Senate to serve as Assistant Secretary for the Department of Energy's Office of Nuclear Energy. Soon afterwards, I joined Pete as his Principal Deputy. In that short time, Pete and I have come to appreciate fully the enormous task we have before us. Transforming our economy from one reliant on fossil fuels to a low carbon future will take investments in energy efficiency and all forms of low carbon energy technologies, including nuclear energy. Our job is to assure that nuclear technologies can contribute to meeting this aggressive goal for reduced greenhouse gas emissions. Nuclear energy can contribute to the future energy supply in two basic areas: (i) in its traditional role of generating electricity and (ii) as a source of process heat for industrial, petrochemical and desalination purposes. Within the Office of Nuclear Energy, we are now developing a roadmap that will help us in 'meeting tomorrow's energy needs' by addressing these two vital areas. We have established five strategic goals as the

  20. Contact dermatitis caused by ECG electrode paste.

    Science.gov (United States)

    Cochran, R J; Rosen, T

    1980-12-01

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

  1. 21 CFR 882.1330 - Depth electrode.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Depth electrode. 882.1330 Section 882.1330 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL... signals at, subsurface levels of the brain. (b) Classification. Class II (performance standards)....

  2. Nickel hydroxide modified electrodes for urea determination

    Directory of Open Access Journals (Sweden)

    Luiz Henrique Dall´Antonia

    2007-03-01

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

  3. Ferroelectric tunnel junctions with graphene electrodes.

    Science.gov (United States)

    Lu, H; Lipatov, A; Ryu, S; Kim, D J; Lee, H; Zhuravlev, M Y; Eom, C B; Tsymbal, E Y; Sinitskii, A; Gruverman, A

    2014-01-01

    Polarization-driven resistive switching in ferroelectric tunnel junctions (FTJs)--structures composed of two electrodes separated by an ultrathin ferroelectric barrier--offers new physics and materials functionalities, as well as exciting opportunities for the next generation of non-volatile memories and logic devices. Performance of FTJs is highly sensitive to the electrical boundary conditions, which can be controlled by electrode material and/or interface engineering. Here, we demonstrate the use of graphene as electrodes in FTJs that allows control of interface properties for significant enhancement of device performance. Ferroelectric polarization stability and resistive switching are strongly affected by a molecular layer at the graphene/BaTiO3 interface. For the FTJ with the interfacial ammonia layer we find an enhanced tunnelling electroresistance (TER) effect of 6 × 10(5)%. The obtained results demonstrate a new approach based on using graphene electrodes for interface-facilitated polarization stability and enhancement of the TER effect, which can be exploited in the FTJ-based devices. PMID:25417720

  4. A tubular electrode for radiofrequency ablation therapy

    KAUST Repository

    Antunes, Carlos Lemos Lemos Lemos

    2012-07-06

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

  5. An installation for pressing pasted electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Matsudzava, S.; Sugimoto, K.

    1983-07-13

    The active mass is placed on the current outlet and the electrode is pressed and its thickness is regulated by passing it through rollers. The water and the adhering particles of the active mass are continuously sucked off during rotation of the rollers.

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

    Science.gov (United States)

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

    1979-01-01

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

  7. Reproducibility of ERG responses obtained with the DTL electrode.

    Science.gov (United States)

    Hébert, M; Vaegan; Lachapelle, P

    1999-03-01

    Previous investigators have suggested that the DTL fibre electrode might not be suitable for the recording of replicable electroretinograms. We present experimental evidence that when used adequately, this electrode does permit the recording of highly reproducible retinal potentials.

  8. Improved zinc electrode and rechargeable zinc-air battery

    Science.gov (United States)

    Ross, P.N. Jr.

    1988-06-21

    The invention comprises an improved rechargeable zinc-air cell/battery having recirculating alkaline electrolyte and a zinc electrode comprising a porous foam support material which carries the active zinc electrode material. 5 figs.

  9. 2-Scale topography dry electrode for biopotential measurements.

    Science.gov (United States)

    Vanlerberghe, F; De Volder, M; de Beeck, M Op; Penders, J; Reynaerts, D; Puers, R; Van Hoof, C

    2011-01-01

    The design and fabrication of a novel 2-scale topography dry electrode using macro and micro needles is presented. The macro needles enable biopotential measurements on hairy skin, the function of the micro needles is to decrease the electrode impedance even further by penetrating the outer skin layer. Also, a fast and reliable impedance characterization protocol is described. Based on this impedance measurement protocol, a comparison study is made between our dry electrode, 3 other commercial dry electrodes and a standard wet gel electrode. Promising results are already obtained with our electrodes which do not have skin piercing micro needles. For the proposed electrodes, three different conductive coatings (Ag/AgCl/Au) are compared. AgCl is found to be slightly better than Ag as coating material, while our Au coated electrodes have the highest impedance.

  10. New cardiac retractor for epicardial electrode insertion via subxiphoid approach.

    Science.gov (United States)

    Sakamoto, T; Arai, H; Suzuki, A

    1993-04-01

    A new retractor for the insertion of epicardial screw-in electrodes is described. We have found that this instrument can be easily applied to the heart and gives excellent exposure for electrode insertion.

  11. In Vivo Demonstration of Addressable Microstimulators Powered by Rectification of Epidermically Applied Currents for Miniaturized Neuroprostheses.

    Directory of Open Access Journals (Sweden)

    Laura Becerra-Fajardo

    Full Text Available Electrical stimulation is used in order to restore nerve mediated functions in patients with neurological disorders, but its applicability is constrained by the invasiveness of the systems required to perform it. As an alternative to implantable systems consisting of central stimulation units wired to the stimulation electrodes, networks of wireless microstimulators have been devised for fine movement restoration. Miniaturization of these microstimulators is currently hampered by the available methods for powering them. Previously, we have proposed and demonstrated a heterodox electrical stimulation method based on electronic rectification of high frequency current bursts. These bursts can be delivered through textile electrodes on the skin. This approach has the potential to result in an unprecedented level of miniaturization as no bulky parts such as coils or batteries are included in the implant. We envision microstimulators designs based on application-specific integrated circuits (ASICs that will be flexible, thread-like (diameters < 0.5 mm and not only with controlled stimulation capabilities but also with sensing capabilities for artificial proprioception. We in vivo demonstrate that neuroprostheses composed of addressable microstimulators based on this electrical stimulation method are feasible and can perform controlled charge-balanced electrical stimulation of muscles. We developed miniature external circuit prototypes connected to two bipolar probes that were percutaneously implanted in agonist and antagonist muscles of the hindlimb of an anesthetized rabbit. The electronic implant architecture was able to decode commands that were amplitude modulated on the high frequency (1 MHz auxiliary current bursts. The devices were capable of independently stimulating the target tissues, accomplishing controlled dorsiflexion and plantarflexion joint movements. In addition, we numerically show that the high frequency current bursts comply with

  12. Development of integrated metal / oxide electrode with electrode housing prepared by spark plasma sintering process

    International Nuclear Information System (INIS)

    We have developed an integrated metal/oxide electrode (IMOE) for a corrosion potential monitoring of the material in light water reactors. Insulation and sealing between the IMOE and the electrode housing are very important in high temperature water. We made an advanced- integrated metal / oxide electrode (AIMOE) by spark plasma sintering (SPS) process as a new reference electrode. The AIMOE can operate in buffer solutions at room temperature. The potential of AIMOE is stable and has a drift of 0.1 mV/hours, which is similar to the potential stability of former IMOE. The measured potential of AIMOE is significantly improved and differs from ideal value within 21 mV. (author)

  13. Improving myoelectric pattern recognition robustness to electrode shift by changing interelectrode distance and electrode configuration.

    Science.gov (United States)

    Young, Aaron J; Hargrove, Levi J; Kuiken, Todd A

    2012-03-01

    Pattern recognition of myoelectric signals for prosthesis control has been extensively studied in research settings and is close to clinical implementation. These systems are capable of intuitively controlling the next generation of dexterous prosthetic hands. However, pattern recognition systems perform poorly in the presence of electrode shift, defined as movement of surface electrodes with respect to the underlying muscles. This paper focused on investigating the optimal interelectrode distance, channel configuration, and electromyography feature sets for myoelectric pattern recognition in the presence of electrode shift. Increasing interelectrode distance from 2 to 4 cm improved pattern recognition system performance in terms of classification error and controllability (p pattern recognition control. Finally, we investigated different feature sets for pattern recognition control using a linear discriminant analysis classifier and found that an autoregressive set significantly (p < 0.01) reduced sensitivity to electrode shift compared to a traditional time-domain feature set.

  14. Extracting electrode space charge limited current: Charge injection into conjugated polyelectrolytes with a semiconductor electrode

    Science.gov (United States)

    Walker, Ethan M.; Lonergan, Mark C.

    2016-05-01

    Conjugated polyelectrolytes and related mixed ionic-electronic conductors (MIECs) are being explored for energy applications including solid-state lighting and photovoltaics. Fundamental models of charge injection into MIECs have been primarily developed for MIECs contacted with highly conductive or metal electrodes (MEs), despite many potential applications involving semiconductors. We theoretically and experimentally demonstrate that an appropriate semiconductor electrode (SE), n-type for electron or p-type of hole injection, can limit injection into MIECs. When the SE is the injecting electrode and is under accumulation, there is little difference from a ME. When the SE acts as the extracting electrode, however, injection into the MIEC can be limited because a fraction of any applied bias must support charge depletion in the semiconductor rather than charge injection into the MIEC. In a ME/MIEC/SE system, this can lead to significant asymmetry in current-voltage and injected charge-voltage behavior.

  15. Stabilizing dimensional changes in Si-based composite electrodes by controlling the electrode porosity: An in situ electrochemical dilatometric study

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Goojin [Green Energy System Center, Kumoh National Institute of Technology, Gumi, Gyeongbuk 730-701 (Korea, Republic of); Lee, Sang Min; Choi, Nam Soon [Battery Development Team, Samsung SDI Co., Ltd. Cheonan, Chungnam 330-300 (Korea, Republic of); Kim, Young-Ugk, E-mail: kyuang@snu.ac.kr [Battery Development Team, Samsung SDI Co., Ltd. Cheonan, Chungnam 330-300 (Korea, Republic of); Lee, Churl Kyoung [School of Advanced Materials and System Engineering, Kumoh National Institute of Technology, Gumi, Gyeongbuk, 730-701 (Korea, Republic of)

    2011-05-30

    Highlights: > A porosity-controllable Si-based composite electrode was fabricated. > PMMA showing unzipping phenomena was utilized as a pore-forming agent. > Cyclic dilation behavior was investigated with an in situ electrochemical dilatometry. > PMMA-treated electrodes exhibited improved cycle performance. > Control of electrode porosity by PMMA can be an effective way for Si-based electrodes. - Abstract: A porosity-controllable Si-based composite electrode was fabricated in the present study. Poly(methyl methacrylate) (PMMA), which possesses the unique thermal property of unzipping, was utilized as a pore-forming agent during electrode fabrication. PMMA-treated electrodes presented relatively low volume expansion and little deformation during lithiation. The cyclic dilation behavior of PMMA-treated electrodes was investigated by applying an in situ electrochemical dilatometric method, and enhanced dimensional reversibility during cycling was observed. The dilation behavior was closely related to the electrochemical performance, and PMMA-treated electrodes exhibited improved capacity retention and low impedance change during cycling. The newly generated pores in the PMMA-treated electrode can accommodate the volumetric expansion of Si-based active materials, which suppresses electrode deformation and the breakdown of the electrical network. The porosity plays an important role in Si-based electrodes. Thus, controlling the porosity through PMMA-treatment can be an effective way for the application of Si-based composite electrodes for advanced lithium-ion batteries.

  16. Results Analysis of IP Address Auto- Configuration in Wireless Manets

    Directory of Open Access Journals (Sweden)

    S. Zahoor Ul Huq

    2011-10-01

    Full Text Available The main task of an address allocation protocol is to manage the address allocation to the nodes in the ad hoc MANETs. All routing protocols assume nodes to be configured a priori with a uniqueIP address. Allocating addresses to mobile nodes is a fundamental and difficult problem. A mobile device cannot participate in unicast communications until it is assigned a conflict-free IP address. So addressing in MANETs is of significant importance, and the address configuration process should be fast, as the algorithm must be able to select, allocate and assign a unique network address to the unconfigured node before with a unique IP address. Here we are providing two solutions for unique address assignment. One is by the using the broadcasting method (BrM, in which unique addresses are assigned, unique addresses are assigned with the cost of network load. This method works fine whenever a new ad hoc network has to be initiated and at a same time a group of nodes have to be configured with a unique IP addresses. But this method loads the network with much network traffic, when new nodes are to be joined. In order to overcome this we are using another approach which uses Modular Arithmetic (MoA. Modular Arithmetic with some modifications is used to generate the unique IP Addresses without loading the network. The proposed scheme is capable of assigning a unique IP address with low communicationoverhead, even addresses distribution and low latency when applied to large scale MANETs and even supports network merging and partitioning..

  17. Nanoscale Electrodes: Nanoscale Electrodes for Flexible Electronics by Swelling Controlled Cracking (Adv. Mater. 30/2016).

    Science.gov (United States)

    Zhao, Qiang; Wang, Wenjun; Shao, Jinyou; Li, Xiangming; Tian, Hongmiao; Liu, Lu; Mei, Xuesong; Ding, Yucheng; Lu, Bingheng

    2016-08-01

    The fabrication of nanospaced electrodes on a flexible substrate is a great challenge. W. Wang, J. Shao, and co-workers propose a novel approach to fabricate nanogap electrodes for flexible electronics using a swelling-controlled cracking method, which is described on page 6337. This method has the advantages of high applicability, parallel manufacturing capacity, and compatibility with flexible substrates. It provides a new way to create high-performance flexible electronics in a cost-efficient fashion.

  18. Performance Comparison between Two Electrodes and Three Electrodes MEMS Capacitive Switch using Architect Coventorware

    Directory of Open Access Journals (Sweden)

    Norhaslinawati Ramli

    2014-01-01

    Full Text Available This paper presents the electromechanical and RF performance comparison between two electrodes and three electrodes MEMS capacitive switch using Architect Coventorware. The important of this study is to react to the industries in providing low actuation voltage MEMS capacitive switches with low loss and high isolation and make it possible to be integrated with CMOS circuit. MEMS capacitive switches with three different support structure namely fixed-fixed beam, single meander and double meander have been designed and simulated in both standard and proposed structure. A standard switch consists of two parallel electrodes and a proposed switch consists of three parallel electrodes. Designing using schematic capture begin by selecting the suitable component from electromechanical library to represent membrane, support structure, anchor, bottom electrode, top electrode, ground, transmission line-in and transmission line-out. The schematic diagram has been simulated and translated to 2D layout and 3D model for physical verification. The electromechanical analysis has been carried out using DC Transfer Analysis. In DC Transfer Analysis, the value of pull-in voltage, up-state and down-state capacitance can be attained. In Small Signal Frequency Analysis the value of resonant frequency is obtained. The measurement of RF performance was done using RF Electrical Analysis. Simulation result shows the pull-in voltage for all proposed design has been reduced 40%-50% as compared to their standard counterpart. While the result for other performance including capacitances for three electrodes switch has almost same value as two electrodes structure. The switch indicates low insertion loss (-26dB in the down-state position. This concludes that the additional top membrane does maintain the good electromechanical and RF performance of MEMS capacitive switch.

  19. Nanoscale Electrodes: Nanoscale Electrodes for Flexible Electronics by Swelling Controlled Cracking (Adv. Mater. 30/2016).

    Science.gov (United States)

    Zhao, Qiang; Wang, Wenjun; Shao, Jinyou; Li, Xiangming; Tian, Hongmiao; Liu, Lu; Mei, Xuesong; Ding, Yucheng; Lu, Bingheng

    2016-08-01

    The fabrication of nanospaced electrodes on a flexible substrate is a great challenge. W. Wang, J. Shao, and co-workers propose a novel approach to fabricate nanogap electrodes for flexible electronics using a swelling-controlled cracking method, which is described on page 6337. This method has the advantages of high applicability, parallel manufacturing capacity, and compatibility with flexible substrates. It provides a new way to create high-performance flexible electronics in a cost-efficient fashion. PMID:27493073

  20. Diffuse charge and Faradaic reactions in porous electrodes

    OpenAIRE

    Biesheuvel, P. M.; Yu, F; Bazant, M.Z.

    2011-01-01

    Porous electrodes instead of flat electrodes are widely used in electrochemical systems to boost storage capacities for ions and electrons, to improve the transport of mass and charge, and to enhance reaction rates. Existing porous electrode theories make a number of simplifying assumptions: (i) The charge-transfer rate is assumed to depend only on the local electrostatic potential difference between the electrode matrix and the pore solution, without considering the structure of ...

  1. Effect of electrode thickness variation on operation of capacitive deionization

    OpenAIRE

    Porada, S.; Bryjak, M.; Wal, van der, A.C.; Biesheuvel, P. M.

    2012-01-01

    In capacitive deionization (CDI) water is desalinated by applying an electrical field between two porous electrodes placed on either side of a spacer channel that transports the aqueous solution. In this work we investigate the equilibrium salt adsorption and the dynamic development of the effluent salt concentration in time, both as function of spacer and electrode thicknesses. The electrode thickness will be varied in a symmetric manner (doubling both electrodes) and in an asymmetric manner...

  2. Non-traditional electrode materials for detection of biomarkers

    OpenAIRE

    Barek, Jiří; Moreira, Josino C.; Wang, Joseph

    2014-01-01

    In this paper, new electrochemical methods suitable for detection of various types of biomarkers (biomarkers of exposition, tumor biomarkers, and biomarkers of medical treatment) are briefly reviewed. Attention is paid to the use of non-traditional electrode materials (various forms of amalgam electrodes, boron doped diamond film electrodes, carbon paste and carbon film electrodes, etc.) for voltammetric (batch analysis) and amperometric (flowing systems) detection of above mentio...

  3. Electroanalysis of organic compounds at bismuth electrodes: a short review

    OpenAIRE

    Lezi, Nikolitsa; Vyskočil, Vlastimil; Economou, Anastasios; Barek, Jiří

    2012-01-01

    Over the last twelve years, it has been demonstrated that bismuth electrodes have comparable electroanalytical performance to mercury electrodes in the negative potential range. Since the toxicicty of bismuth is lower than that of mercury, bismuth can serve as an alternative “green” electrode material to mercury. However, the great majority of published work at bismuth–based electrodes is concerned with the determination of trace metals by voltammetric techniques with only few applications de...

  4. MHD generator with improved network coupling electrodes to a load

    Science.gov (United States)

    Rosa, Richard J.

    1977-01-01

    An MHD generator has a plurality of segmented electrodes extending longitudinally of a duct, whereby progressively increasing high DC voltages are derived from a set of cathode electrodes and progressively increasing low DC voltages are derived from a set of anode electrodes. First and second load terminals are respectively connected to the cathode and anode electrodes by separate coupling networks, each of which includes a number of SCR's and a number of diode rectifiers.

  5. Non-Contact ECG Sensing Employing Gradiometer Electrodes

    OpenAIRE

    Peng, GuoChen; Bocko, Mark F.

    2012-01-01

    Noncontact, capacitive electrocardiogram (ECG) measurements are complicated by motion artifacts from the relative movement between the ECG electrodes and the subject. To compensate for such motion we propose to employ first and second order gradiometer electrode designs. A MATLAB-based simulation tool to enable assessment of different electrode configurations and placements on human subjects has been developed to guide the refinement of electrode designs. Experimental measurements of the sens...

  6. 12 CFR 5.52 - Change of address.

    Science.gov (United States)

    2010-01-01

    ... CORPORATE ACTIVITIES Other Changes in Activities and Operations § 5.52 Change of address. (a) Authority. 12... 12 Banks and Banking 1 2010-01-01 2010-01-01 false Change of address. 5.52 Section 5.52 Banks and... notify the OCC of any change in its address. However, no notice is required if the change in...

  7. An Efficient Geographical Addressing Scheme for the Internet

    NARCIS (Netherlands)

    Meijerink, Bernd; Baratchi, Mitra; Heijenk, Geert

    2016-01-01

    Geocast is a scheme which allows packets to be sent to a destination area instead of an address. This allows the addressing of any device in a specific region without further knowledge. In this paper we present an addressing mechanism that allows efficient referral to areas of arbitrary size. The bi

  8. Address Terms among University Students in Ghana: A Case Study

    Science.gov (United States)

    Afful, Joseph Benjamin Archibald

    2006-01-01

    An important feature of the interface between language and society is the use of address terms. Following Brown and Gilman (1960), research studies of address terms have been extended to several cultural settings. This study contributes to this fertile area of sociolinguistic studies by describing the address terms used among undergraduates in an…

  9. 76 FR 22681 - Defense Logistics Agency (DLA) Address Directory

    Science.gov (United States)

    2011-04-22

    ... of the Secretary Defense Logistics Agency (DLA) Address Directory AGENCY: Department of Defense. ACTION: Notice. SUMMARY: The Defense Logistics Agency (DLA) is updating its Address Directory which is.... Jody Sinkler, 703-767-5045. SUPPLEMENTARY INFORMATION: DLA Address Directory: Defense Logistics...

  10. Individually addressable cathodes with integrated focusing stack or detectors

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, Clarence E.; Baylor, Larry R.; Voelkl, Edgar; Simpson, Michael L.; Paulus, Michael J.; Lowndes, Douglas; Whealton, John; Whitson, John C.; Wilgen, John B.

    2005-07-12

    Systems and method are described for addressable field emission array (AFEA) chips. A plurality of individually addressable cathodes are integrated with an electrostatic focusing stack and/or a plurality of detectors on the addressable field emission array. The systems and methods provide advantages including the avoidance of space-charge blow-up.

  11. Rotating electrode potentiometry: lowering the detection limits of nonequilibrium polyion-sensitive membrane electrodes.

    Science.gov (United States)

    Ye, Q; Meyerhoff, M E

    2001-01-15

    A rotating electrode configuration is evaluated as a means to lower the detection limits of newly devised polyion-sensitive membrane electrodes (PSEs). Planar potentiometric polycation and polyanion PSEs are prepared by incorporating tridodecylmethylammonium chloride and calcium dinonylnaphthalenesulfonate, respectively, into plasticized PVC or polyurethane membranes and mounting disks of such films on an electrode body housed in a conventional rotating disk electrode apparatus. Rotation of the PSEs at 5000 rpm results in an enhancement in the detection limits toward heparin (polyanion) and protamine (polycation) of at least 1 order of magnitude (to 0.01 unit/mL for heparin; 0.02 microg/mL for protamine) over that observed when the EMF responses of the same electrodes are assessed using a stir-bar to achieve convective mass transport. A linear relationship between omega(-1/2), where omega is the rotating angular frequency, and C1/2, the polyion concentration corresponding to half the total maximum deltaEMF response toward the polyion species, is observed. It is further shown that the rotating polycation sensor can be used as an end-point detector to greatly enhance (relative to nonrotated indicator electrode) the analytical resolution and precision for measurement of low concentrations of heparin when such samples are titrated with protamine. The theoretical basis for lowering the detection limits by rotating PSEs is discussed based on the unique nonequilibrium response mechanism of such sensors.

  12. 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.

  13. Improving Electrode Durability of PEF Chamber by selecting suitable material

    Science.gov (United States)

    Corrosion resistance of four materials - titanium, platinized titanium, stainless steel, and boron carbide - as electrodes in a Pulsed Electric Field (PEF) system was studied to reduce electrode material migration into the food by electrode corrosion. The PEF process conditions were 28 kV/cm field s...

  14. 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.

  15. Heavy metals detection using nanostructured screen printed electrodes

    Directory of Open Access Journals (Sweden)

    Jan Prasek*

    2010-12-01

    Full Text Available This work deals with the problematic of heavy metals dissolved inaqueous solution detection using standard electrochemical methods. The problematic of low signal response of miniaturizedelectrochemical electrodes for electrochemical analysis is mentioned here. Finally some solutions for electrodes miniaturization and examples of fabricated electrodes and their heavy metals detection capabilities on a real sample are shown and discussed here.

  16. Plastic Membrane Sensor from a Disposed Combined Glass Electrode

    Science.gov (United States)

    Marafie, Hayat M.; Shoukry, Adel F.; Alshatti, Laila A.

    2007-01-01

    The construction of combined plastic membrane electrode for hydralazinium cation from a disposed glass electrode is described. A variety of electrodes could be prepared by students using other types of polymers, plasticizers, or exchangers which could also help to study effects of pH and temperature, or environmental investigations.

  17. Adsorption of azithromycin dehydrate at stationary mercury and solid electrode

    OpenAIRE

    Karbainov, Yu. A.; Puchkovskaya, E. S.; Karbainova, S. N.

    2007-01-01

    Adsorptive component in oxidation and renewal processes at different types of electrodes for antibiotic-macrolide azithromycin dihydrate has been studied. Adsorption parameters for azithromycin oxidation processes at glass-carbon electrode and for renewal processes at mercury-film electrode were calculated

  18. Materials analyses and electrochemical impedance of implantable metal electrodes.

    Science.gov (United States)

    Howlader, Matiar M R; Ul Alam, Arif; Sharma, Rahul P; Deen, M Jamal

    2015-04-21

    Implantable electrodes with high flexibility, high mechanical fixation and low electrochemical impedance are desirable for neuromuscular activation because they provide safe, effective and stable stimulation. In this paper, we report on detailed materials and electrical analyses of three metal implantable electrodes - gold (Au), platinum (Pt) and titanium (Ti) - using X-ray photoelectron spectroscopy (XPS), scanning acoustic microscopy, drop shape analysis and electrochemical impedance spectroscopy. We investigated the cause of changes in electrochemical impedance of long-term immersed Au, Pt and Ti electrodes on liquid crystal polymers (LCPs) in phosphate buffered saline (PBS). We analyzed the surface wettability, surface and interface defects and the elemental depth profile of the electrode-adhesion layers on the LCP. The impedance of the electrodes decreased at lower frequencies, but increased at higher frequencies compared with that of the short-term immersion. The increase of impedances was influenced by the oxidation of the electrode/adhesion-layers that affected the double layer capacitance behavior of the electrode/PBS. The oxidation of the adhesion layer for all the electrodes was confirmed by XPS. Alkali ions (sodium) were adsorbed on the Au and Pt surfaces, but diffused into the Ti electrode and LCPs. The Pt electrode showed a higher sensitivity to surface and interface defects than that of Ti and Au electrodes. These findings may be useful when designing electrodes for long-term implantable devices.

  19. Skin impedance comparisons of electrodes for electro-oculography.

    Science.gov (United States)

    Lee, J B; Reinecke, R D

    1991-01-01

    In an effort to define the most comfortable electrode needing the simplest skin preparation with low and stable skin impedance, we compared the impedance between skin electrodes and Stat-Trace II St-102 EKG electrodes (Niko Med USA, New Brunswick, NJ)--the latter being renamed "dry electrodes" because they are used without electrolyte paste--on 12 normal subjects with two different skin preparations, with and without alcohol. The dry electrodes were found to have lower impedance than the skin electrodes. With each skin preparation the alcohol scored better, 7.2 kOhm vs 16.5 kOhm, respectively, and "no preparation" worse, 13.8 kOhm vs 22.7 kOhm, respectively, (but still acceptable when the dry electrode was used). The dry electrode's impedance was quite stable from the moment of application while the skin electrode's impedance drifted dramatically for 30 minutes. If the dry electrode was halved in area of skin contact, as often is necessary with the nasal electrode in children, the impedance rose proportionally but remained acceptable. We conclude that the new dry electrodes give us improved electro-oculography records and suggest their use, particularly for infants and young children where ease of application and simple skin preparation are particularly important.

  20. 21 CFR 876.1400 - Stomach pH electrode.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Stomach pH electrode. 876.1400 Section 876.1400...) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Diagnostic Devices § 876.1400 Stomach pH electrode. (a) Identification. A stomach pH electrode is a device used to measure intragastric and intraesophageal pH...

  1. A method for making electrodes for lead storage batteries

    Energy Technology Data Exchange (ETDEWEB)

    Ivaki, T.; Kobayasi, K.

    1983-06-04

    Powder, acid resistant thermoplastic resin is applied to a greased electrode of a lead storage battery. The electrode is heated until the resin melts, cooled, producing a film of hardened resin with fine cracks in the absence of pores. The electrode has a long service life with cycling.

  2. Cyclic voltammetry on n-alkylphosphonic acid self-assembled monolayer modified large area indium tin oxide electrodes

    International Nuclear Information System (INIS)

    We show stable bonding of n-alkylphosphonic acid self-assembled monolayers (SAMs) to indium tin oxide electrodes and their direct electrical characterization by cyclic voltammetry (CV). The functional coatings were investigated with regards to the addressability and stability of the electrodes, which are related to small changes in molecular layer thickness. The response of a redox active compound in solution to the faradic current is indirectly proportional to the molecular chain length of the SAMs. We observed a decrease of the electrode sensitivity with enhanced surface protection and slow long term degradation of the SAM under electrochemical stress by CV, and therefore conclude a trade-off optimum for molecules with the C10 chain.

  3. Cooperation of micro- and meso-porous carbon electrode materials in electric double-layer capacitors

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Cheng [State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, 5625 Renmin Street, Changchun 130022, Jilin Province (China); Graduate University of Chinese Academy of Sciences, Beijing 100039 (China); Qi, Li; Wang, Hongyu [State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, 5625 Renmin Street, Changchun 130022, Jilin Province (China); Yoshio, Masaki [Advanced Research Center, Saga University, 1341 Yoga-machi, Saga 840-0047 (Japan)

    2010-07-01

    The capacitive characteristics of micro- and meso-porous carbon materials have been compared in cyclic voltammetric studies and galvanostatic charge-discharge tests. Meso-porous carbon can keep certain high capacitance values at high scan rates, whereas micro-porous carbon possesses very high capacitance values at low scan rates but fades quickly as the scan rate rises up. For better performance of electric double-layer capacitors (EDLCs), the cooperative application of both kinds of carbon materials has been proposed in the following two ways: mixing both kinds of carbons in the same electrode or using the asymmetric configuration of carbon electrodes in the same EDLC. The cooperative effect on the electrochemical performance has also been addressed. (author)

  4. Multifunctional oxides for integrated manufacturing of efficient graphene electrodes for organic electronics

    Energy Technology Data Exchange (ETDEWEB)

    Kidambi, Piran R.; Robertson, John; Hofmann, Stephan [Department of Engineering, University of Cambridge, 9 JJ Thomson Avenue, Cambridge CB3 0FA (United Kingdom); Weijtens, Christ; Meyer, Jens, E-mail: jens.meyer@philips.com [Philips Research, Philipsstrasse 8, 52068 Aachen (Germany)

    2015-02-09

    Using multi-functional oxide films, we report on the development of an integration strategy for scalable manufacturing of graphene-based transparent conducting electrodes (TCEs) for organic electronics. A number of fundamental and process challenges exists for efficient graphene-based TCEs, in particular, environmentally and thermally stable doping, interfacial band engineering for efficient charge injection/extraction, effective wetting, and process compatibility including masking and patterning. Here, we show that all of these challenges can be effectively addressed at once by coating graphene with a thin (>10 nm) metal oxide (MoO{sub 3} or WO{sub 3}) layer. We demonstrate graphene electrode patterning without the need for conventional lithography and thereby achieve organic light emitting diodes with efficiencies exceeding those of standard indium tin oxide reference devices.

  5. Study on microstructures of electrodes in lithium-ion batteries using variational multi-scale enrichment

    Science.gov (United States)

    Lee, Sangmin; Sastry, Ann Marie; Park, Jonghyun

    2016-05-01

    Performance and degradation of a Li-ion battery reflect the transport and kinetics of related species within the battery's electrode microstructures. The variational multi-scale principle is adapted to a Li-ion battery system in order to improve the predictions of battery performance by including multi-scale and multiphysics phenomena among the particle aggregates in the electrode; this physics cannot be addressed by conventional homogenized approaches. The developed model is verified through the direct numerical solutions and compared with the conventional pseudo-2D (P2D) model method. The developed model has revealed more dynamic battery behaviors related to the variation of the microstructure-such as particle shape, tortuosity, and material composition-while the corresponding result from P2D shows a monotonous change within different structures.

  6. Biofouling resistance of boron-doped diamond neural stimulation electrodes is superior to titanium nitride electrodes in vivo

    DEFF Research Database (Denmark)

    Meijs, Suzan; Alcaide, Maria; Sørensen, Charlotte;

    2016-01-01

    OBJECTIVE: The goal of this study was to assess the electrochemical properties of boron-doped diamond (BDD) electrodes in relation to conventional titanium nitride (TiN) electrodes through in vitro and in vivo measurements. APPROACH: Electrochemical impedance spectroscopy, cyclic voltammetry and ...... electrodes possess a superior biofouling resistance, which provides significantly stable electrochemical properties both in protein solution as well as in vivo compared to TiN electrodes....

  7. Electrode contact impedance sensitivity to variations in geometry

    International Nuclear Information System (INIS)

    Electrode contact impedance is a crucial factor in physiological measurements and can be an accuracy-limiting factor when performing electroencephalography and electrical impedance tomography. In this work, standard flat electrodes and micromachined multipoint spiked electrodes are characterized with a finite-element method electromagnetic solver and the dependence of the contact impedance on geometrical factors is explored. It is found that flat electrodes are sensitive to changes in the outer skin layer properties related to hydration and thickness, while spike electrodes are not. The impedance as a function of the effective contact area, number of spikes and penetration depth has also been studied and characterized. (paper)

  8. Apparatus for electrode current control in linear MHD generators

    Science.gov (United States)

    Demirjian, Ara M.; Solbes, Albert

    1984-01-01

    Apparatus for controlling a plurality of opposing, electrode, direct-currents at pre-set locations across a channel that comprises a converter for converting each electrode current into first and second periodic control signals which are 180.degree. out of phase with respect to each other and which have equal magnitudes corresponding to the magnitude of the associated electrode current; and couplers for magnetically coupling individual ones of the first control signals and for magnetically coupling individual ones of the second signals such that the corresponding electrode currents are equalized or rendered proportional by balancing the same in the same or constant ratios in accordance with the locations of the electrode currents.

  9. Graphene-based battery electrodes having continuous flow paths

    Science.gov (United States)

    Zhang, Jiguang; Xiao, Jie; Liu, Jun; Xu, Wu; Li, Xiaolin; Wang, Deyu

    2014-05-24

    Some batteries can exhibit greatly improved performance by utilizing electrodes having randomly arranged graphene nanosheets forming a network of channels defining continuous flow paths through the electrode. The network of channels can provide a diffusion pathway for the liquid electrolyte and/or for reactant gases. Metal-air batteries can benefit from such electrodes. In particular Li-air batteries show extremely high capacities, wherein the network of channels allow oxygen to diffuse through the electrode and mesopores in the electrode can store discharge products.

  10. Graphene nanocomposites for electrochemical cell electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Zhamu, Aruna; Jang, Bor Z.; Shi, Jinjun

    2015-11-19

    A composite composition for electrochemical cell electrode applications, the composition comprising multiple solid particles, wherein (a) a solid particle is composed of graphene platelets dispersed in or bonded by a first matrix or binder material, wherein the graphene platelets are not obtained from graphitization of the first binder or matrix material; (b) the graphene platelets have a length or width in the range of 10 nm to 10 .mu.m; (c) the multiple solid particles are bonded by a second binder material; and (d) the first or second binder material is selected from a polymer, polymeric carbon, amorphous carbon, metal, glass, ceramic, oxide, organic material, or a combination thereof. For a lithium ion battery anode application, the first binder or matrix material is preferably amorphous carbon or polymeric carbon. Such a composite composition provides a high anode capacity and good cycling response. For a supercapacitor electrode application, the solid particles preferably have meso-scale pores therein to accommodate electrolyte.

  11. Bismuth electrodes, an alternative in stripping voltammetry

    International Nuclear Information System (INIS)

    The heavy metals are known as highly toxic contaminants, the processes carried out in industry contribute that finally they remain dispersed in effluents and sewage, doing part of the food chain. The importance of controlling the levels of these heavy metals has become an international policy, so it has generated interest in developing new analytical methodologies for its determination [1, 2, 3, 4]. The stripping voltammetry has been considered as a family of electro-sensitive analytical techniques useful for the determination of trace levels of many metals in environmental, clinical and industrial samples [3, 4]. This work presents an overview of these bismuth-based electrodes which were introduced around 2000, which have interesting characteristics for detection of heavy metals and which represent an alternative to mercury electrodes

  12. Method for making thin carbon foam electrodes

    Energy Technology Data Exchange (ETDEWEB)

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

    1999-08-03

    A method for fabricating thin, flat carbon electrodes by infiltrating highly porous carbon papers, membranes, felts, metal fibers/powders, or fabrics with an appropriate carbon foam precursor material is disclosed. The infiltrated carbon paper, for example, is then cured to form a gel-saturated carbon paper, which is subsequently dried and pyrolyzed to form a thin sheet of porous carbon. The material readily stays flat and flexible during curing and pyrolyzing to form thin sheets. Precursor materials include polyacrylonitrile (PAN), polymethylacrylonitrile (PMAN), resorcinol/formaldehyde, catechol/formaldehyde, phenol/formaldehyde, etc., or mixtures thereof. These thin films are ideal for use as high power and energy electrodes in batteries, capacitors, and fuel cells, and are potentially useful for capacitive deionization, filtration and catalysis.

  13. Method for making thin carbon foam electrodes

    Energy Technology Data Exchange (ETDEWEB)

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

    1999-01-01

    A method for fabricating thin, flat carbon electrodes by infiltrating highly porous carbon papers, membranes, felts, metal fibers/powders, or fabrics with an appropriate carbon foam precursor material. The infiltrated carbon paper, for example, is then cured to form a gel-saturated carbon paper, which is subsequently dried and pyrolyzed to form a thin sheet of porous carbon. The material readily stays flat and flexible during curing and pyrolyzing to form thin sheets. Precursor materials include polyacrylonitrile (PAN), polymethylacrylonitrile (PMAN), resorcinol/formaldehyde, catechol/formaldehyde, phenol/formaldehyde, etc., or mixtures thereof. These thin films are ideal for use as high power and energy electrodes in batteries, capacitors, and fuel cells, and are potentially useful for capacitive deionization, filtration and catalysis.

  14. Screening of redox couples and electrode materials

    Science.gov (United States)

    Giner, J.; Swette, L.; Cahill, K.

    1976-01-01

    Electrochemical parameters of selected redox couples that might be potentially promising for application in bulk energy storage systems were investigated. This was carried out in two phases: a broad investigation of the basic characteristics and behavior of various redox couples, followed by a more limited investigation of their electrochemical performance in a redox flow reactor configuration. In the first phase of the program, eight redox couples were evaluated under a variety of conditions in terms of their exchange current densities as measured by the rotating disk electrode procedure. The second phase of the program involved the testing of four couples in a redox reactor under flow conditions with a varity of electrode materials and structures.

  15. HVDC power transmission electrode siting and design

    Energy Technology Data Exchange (ETDEWEB)

    Holt, R.J. [NDT Engineering, Inc., Shrewbury, MA (United States); Dabkowski, J. [Electro-Sciences, Inc., Crystal Lake, IL (United States); Hauth, R.L. [New England Power Service Co., Westborough, MA (United States)

    1997-04-01

    This research strives to shed light on the feasibility and practicality of using deep earth electrodes to permit their use for extended periods without adverse consequences. This report begins with a review of the fundamentals associated with current conduction in earth, including the various techniques available for measuring the earth`s electrical properties. The sources of existing data are discussed and some specific data for selected regions of the U.S. and Canada are reviewed as examples. Electrode technology and design issues are reviewed and recent experience gained by New England Power and Hydro-Quebec is discussed. The issues associated with direct current flowing in underground pipelines (and other facilities) are described and the present-day mitigation measures are evaluated. Suggestions are made for further R&D in the coordination of cathodic protection systems, an area that has evolved as an empirical, trial- and-error art more than a science.

  16. Influence on discharge uniformity of electrodes configuration

    CERN Document Server

    Zheng Jian; Sui Zhan; Lu Jing Ping; Zheng Kui Xing; Zhang Xiong Jun; Dong Yun; Feng Bin

    2002-01-01

    Large area glow discharge plasma that is transparent and highly conductive can be used as electrodes in Pockels cell to extend the switch aperture. To investigate this technology, a glow discharging chamber with a clear aperture of 5 cm x 5 cm was constructed, and hollow cathode, button cathode, pin cathode, bar cathode and bar anode were designed and produced. Using CCD imaging system, the discharging uniformity of different cathodes was tested with bar anode and under the different pressure pre-ionization voltage and main discharging voltage. A uniform plasma can be obtained with a hollow cathode when the pre-ionization voltage is about 700 V, the pressure is about 30 Pa, and the main discharging voltage is about 4 kV, which can be used for the plasma electrode of Pockels cell

  17. SAW reflection and scattering by electrodes

    Institute of Scientific and Technical Information of China (English)

    WANG Wei-biao; HAN Tao; ZHANG Xiao-dong; WU Hao-dong; SHUI Yong-an

    2005-01-01

    A rigorous analysis of surface acoustic wave (SAW) reflection and scattering by electrodes is of paramount importance in the design of SAW identification tags and sensors. In this paper, a new method based on Green's function concept is used to study reflection and scattering coefficients. By this method the reflection coefficient with its phase angle, transmission coefficient, and bulk wave scattering coefficient, can be obtained rapidly and accurately. To get precise result, the influence of static charge must be taken into account. In the work, we successfully cancelled out the effect of static charge and the validity of the results was checked. As an example, the reflection, transmission and scattering coefficients ora single grounded electrode on 128°YX LiNbO3 is shown.

  18. Bismuth electrodes, an alternative in stripping voltammetry

    Science.gov (United States)

    Barón-Jaimez, J.; Joya, M. R.; Barba-Ortega, J.

    2013-11-01

    The heavy metals are known as highly toxic contaminants, the processes carried out in industry contribute that finally they remain dispersed in effluents and sewage, doing part of the food chain. The importance of controlling the levels of these heavy metals has become an international policy, so it has generated interest in developing new analytical methodologies for its determination [1, 2, 3, 4]. The stripping voltammetry has been considered as a family of electro-sensitive analytical techniques useful for the determination of trace levels of many metals in environmental, clinical and industrial samples [3, 4]. This work presents an overview of these bismuth-based electrodes which were introduced around 2000, which have interesting characteristics for detection of heavy metals and which represent an alternative to mercury electrodes.

  19. Reproducibility of electroretinograms recorded with DTL electrodes.

    Science.gov (United States)

    Hébert, M; Lachapelle, P; Dumont, M

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

  20. Phase Transformation Dynamics in Porous Battery Electrodes

    CERN Document Server

    Ferguson, Todd R

    2014-01-01

    Porous electrodes composed of multiphase active materials are widely used in Li-ion batteries, but their dynamics are poorly understood. Two-phase models are largely empirical, and no models exist for three or more phases. Using a modified porous electrode theory based on non-equilibrium thermodynamics, we show that experimental phase behavior can be accurately predicted from free energy models, without artificially placing phase boundaries or fitting the open circuit voltage. First, we simulate lithium intercalation in porous iron phosphate, a popular two-phase cathode, and show that the zero-current voltage gap, sloping voltage plateau and under-estimated exchange currents all result from size-dependent nucleation and mosaic instability. Next, we simulate porous graphite, the standard anode with three stable phases, and reproduce experimentally observed fronts of color-changing phase transformations. These results provide a framework for physics-based design and control for electrochemical systems with comp...