Various Types Of Electrodes Research Articles

Hydrogen recovery from the photovoltaic electroflocculation-flotation process for harvesting Chlorella pyrenoidosa microalgae

In this paper, an integrated process using photovoltaic power to harvest microalgae by electro-flocculation (EF) and hydrogen recovery is presented. It is mainly favorable in regions with high solar radiation. The electro-flocculation efficiency (EFE) of Chlorella pyrenoidosa microalgae was investigated using various types of electrodes (aluminum, iron, zinc, copper and a non-sacrificial electrode of carbon). The best results regarding the EFE, and biomass contamination were achieved with aluminum and carbon electrodes where the electrical energy demand of the process for harvesting 1 kg of algae biomass was 0.28 and 0.34 kWh, respectively, while the energy yield of harvested hydrogen was 0.052 and 0.005 kWh kg−1, respectively. The highest harvesting efficiency of 95.83 ± 0.87% was obtained with the aluminum electrode.The experimental hydrogen yields obtained were comparable with those calculated from theory. With a low net energy demand, microalgae EF may be a useful and low-cost technology.

An Analysis of the Weldability of Ductile Cast Iron Using Inconel 625 for the Root Weld and Electrodes Coated in 97.6% Nickel for the Filler Welds

This article examines the weldability of ductile cast iron when the root weld is applied with a tungsten inert gas (TIG) welding process employing an Inconel 625 source rod, and when the filler welds are applied with electrodes coated with 97.6% Ni. The welds were performed on ductile cast iron specimen test plates sized 300 mm × 90 mm × 10 mm with edges tapered at angles of 60°. The plates were subjected to two heat treatments. This article analyzes the influence on weldability of the various types of electrodes and the effect of preheat treatments. Finally, a microstructure analysis is made of the material next to the weld in the metal-weld interface and in the weld itself. The microstructure produced is correlated with the strength of the welds. We treat an alloy with 97.6% Ni, which prevents the formation of carbides. With a heat treatment at 900 °C and 97.6% Ni, there is a dissolution of all carbides, forming nodules in ferritic matrix graphite.

Transverse dynamics of slender piezoelectric bimorphs with resistive-inductive electrodes

This paper presents and compares a one-dimensional (1D) bending theory for piezoelectric thin beam-type structures with resistive-inductive electrodes to ANSYS three-dimensional (3D) finite element (FE) analysis. In particular, the lateral deflections and vibrations of slender piezoelectric beams are considered. The peculiarity of the piezoelectric beam model is the modeling of electrodes in such a manner that is does not fulfill the equipotential area condition. The case of ideal, perfectly conductive electrodes is a special case of our 1D model. Two-coupled partial differential equations are obtained for the lateral deflection and for the voltage distribution along the electrodes: the first one is an extended Bernoulli-Euler beam equation (second-order in time, forth order in space) and the second one the so-called Telegrapher\'s equation (second-order in time and space). Analytical results of our theory are validated by 3D electromechanically coupled FE simulations with ANSYS. A clamped-hinged beam is considered with various types of electrodes for the piezoelectric layers, which can be either resistive and/or inductive. A natural frequency analysis as well as quasi-static and dynamic simulations are performed. A good agreement between the extended beam theory and the FE results is found. Finally, the practical relevance of this type of electrodes is shown. It is found that the damping capability of properly tuned resistive or resistive-inductive electrodes exceeds the damping performance of beams, where the electrodes are simply linked to an optimized impedance.

ナノ電気化学セル顕微鏡を用いた電極表面の局所電気化学測定

Scanning electrochemical cell microscopy with a single barrel nanopipette (nanoSECCM), which is one of scanning electrochemical microscope (SECM) families, is a powerful tool for analyzing electrochemical activities (e.g. redox reaction and lithium-ion (de) intercalation processes) at localized area. A glass nano-pipette is used as a probe of nanoSECCM filled with electrolyte and a reference electrode. As the pipette is in proximity of sample surface, a meniscus is created. Through the meniscus, electrochemical activities can be obtained at localized area on the sample. Further, as the pipette scans the sample surface, electrochemical activities can be also visualized. Our experiments demonstrate that nanoSECCM is applicable to investigation of current response related to lithium-ion transport, redox cycling on various types of electrodes.

Influences of solution plasma conditions on degradation rate and properties of chitosan

Abstract In this work, the effects of solution plasma conditions on the degradation rate and properties of chitosan are investigated. Various types of electrodes including tungsten (W), copper (Cu), and iron (Fe) were used. The treatment time and the applied pulse frequency of the bipolar supply varied from 0 to 210 min and 15 to 30 kHz, respectively. The plasma-treated chitosan was characterized by GPC, XRD, FT-IR, and fractionation analysis. The results showed that after plasma treatment for 210 min, the molecular weight of chitosan decreased remarkably, when compared to those of untreated samples. The plasma treatment of chitosan using Fe electrode and high pulse frequency strongly promoted the degradation rate of chitosan. The XRD analysis showed that the crystallinity of plasma-treated chitosan was destroyed. FT-IR analysis revealed that the chemical structure of chitosan was not changed by solution plasma treatment. Solution plasma treatment of chitosan using an Fe electrode provided the highest %yield of water-soluble chitosan. Industrial Relevance In this study, the solution plasma process is introduced to treat chitosan in order to prepare low-molecular-weight chitosan. According to our finding, the solution plasma could be a potential method for the preparation of low-molecular-weight chitosan and chitooligosaccharides. Since the solution plasma is generated under mild conditions (i.e., the reaction proceeds at room temperature and ambient pressure), therefore, it is very attractive for the degradation of polysaccharide polymer and applicable to industrial materials process such as medicine, food, chemical industry, and cosmetics. In addition, we expected that plasma technology could be used instead of conventional enzymatic treatment and chemical treatment which was high cost and contamination process.

Effect of the development of electrical parallel discharges on performance of polluted insulators under DC voltage

Our work consists of studying the development of parallel discharges on a broad insulating surface simultaneously under uniform pollution’s conditions and DC voltage. This phenomenon plays a very important role on the electric performance of this insulation. The parameters of influence considered in this paper are the following: the width of the polluted material, the degree of its contamination and the polarity of the applied voltage. The tests were performed on a rectangular surface of a glass with various dimensions, and various types of electrodes (rods, planes) were used. The visualization of the parallel discharges was performed by a fast camera. The experimental results emanated from this study show that there is a limiting band width of pollution from which two consecutive electric arcs can develop independently until the insulation’s flashover with a minimal voltage. The value of this limiting width is approximately 12 cm in positive polarity and 20 cm in negative polarity. It was noted that this limiting effective width is not influenced at all by the variation of the wet layer’s volume conductivity. In this paper, two methods and empirical equation were used to confirm these results. In addition, the results indicate that any plane–plane system of electrodes can be associated with multiple rods-rods configurations, which have the same performance.

Applications of AC Impedance Spectroscopy as Characterization and Diagnostic Tool in Li-Metal Battery Cells

Electrochemical Impedance spectroscopy (EIS) is exceptionally powerful and rapidly evolving technique for investigating electrical properties of materials and electrochemical interfacial kinetic processes in wide variety of practical systems and applications. The method offers the most powerful on-line and off-line analysis of the status of investigated media, electrodes, and probes in many different complex time– and space-resolved processes that occur in electrochemical laboratory experiments or over a lifetime of monitored samples, devices, or materials. EIS is useful as an empirical quality control procedure that can also be employed to interpret fundamental electrochemical processes [1, 2]. At NASA Glenn Research Center the EIS technique is being widely and effectively employed in characterization and performance monitoring of rechargeable energy storage devices, such as states of electrodes during charging / discharging cycles in secondary batteries and fuel cells. The technical objective for batteries is to improve the performance of rechargeable cells to meet the energy storage requirements of human missions. The approach is to develop advanced battery components to safely provide substantially higher specific energy for relatively few charge/discharge cycles. In the presented work, impedance spectroscopy and other electrochemical and surface science techniques have been widely applied to monitoring developed lithium-metal battery (LMB) cells, including investigation of the impact of novel ionic liquid electrolytes on cycle life and dendrite growth/suppression on Li anodes. Applications of EIS method allowed for efficient in situ performance monitoring of various types of electrodes and electrolytes used in experimental battery cells. The studies were focused initially on evaluating performance of separate battery components in symmetric lithium coin cells, with a purpose of future complete impedance analysis of full cells with Li anode and dedicated cathode.

Female urinary incontinence and intravaginal electrical stimulation: an observational prospective study

ObjectiveTo assess the efficacy of intravaginal electrical stimulation in the management of female urinary incontinence. Study design359 Women with urinary incontinence (207 with stress incontinence [group A], 33 with urge incontinence [group B] and 119 with mixed urinary incontinence [group C]) were included in this multicenter prospective observational study. Patients were managed by home intravaginal electrical stimulation of the pelvic floor for 20–30min per day, 5 days a week, for a period of 10 weeks. Identical clinical assessments were performed before and after pelvic floor rehabilitation, comprising a voiding diary and validated symptom and quality of life scores. ResultsObjective assessment demonstrated an overall cure rate of 63.5% (228/359): 65.7% (136/207) for group A, 57.6% (19/33) for group B, and 61.3% (73/119) for group C. The overall significant improvement rate was 15.6% (56/359): 14.6% (30/207) for group A, 24.2% (8/33) for group B and 15.1% (18/119) for group C. All domains of quality of life were significantly improved after pelvic floor muscle training (p<0.0001) with a patient satisfaction rate of 83.6%. Treatment was well tolerated with 1.4% (5/359) of patients describing pain at the highest stimulation intensities. No significant difference was observed between the various types of electrodes used (p<0.0001). ConclusionThe quantitative and qualitative efficacy in terms of social and psychological consequences and quality of life of home pelvic floor muscle training stimulators probably make this treatment modality one of the first-line treatments for female stress urinary incontinence.

A Universal Method to Produce Low–Work Function Electrodes for Organic Electronics

Organic and printed electronics technologies require conductors with a work function that is sufficiently low to facilitate the transport of electrons in and out of various optoelectronic devices. We show that surface modifiers based on polymers containing simple aliphatic amine groups substantially reduce the work function of conductors including metals, transparent conductive metal oxides, conducting polymers, and graphene. The reduction arises from physisorption of the neutral polymer, which turns the modified conductors into efficient electron-selective electrodes in organic optoelectronic devices. These polymer surface modifiers are processed in air from solution, providing an appealing alternative to chemically reactive low-work function metals. Their use can pave the way to simplified manufacturing of low-cost and large-area organic electronic technologies.

Study on Adhesive Strength between Ge2Sb2Te5 Film and Electrodes for Phase Change Memory Application

The adhesive strength between a phase change film and electrodes is important for the application of phase change random access memory. The adhesive strength between Ge2Sb2Te5 and various types of electrodes as a function of annealing temperature was investigated using Nano Indenter®. The structural transformation of Ge2Sb2Te5 during annealing was studied by X-ray diffraction. Results show that adhesive strength decreases with an increase in annealing temperature. The adhesive strength between amorphous Ge2Sb2Te5 and electrodes is higher than that between polycrystalline Ge2Sb2Te5 and electrodes, and TiN is a better choice as a heating electrode in the phase change memory application than W and Ti.

Bingham characteristics of polymer‐based electrorheological fluids with different electrode gaps and materials

AbstractThis article presents experimental results on the influence of the electrode gap and electrode material on the Bingham characteristics of polymer‐based electrorheological (ER) fluids. An experimental apparatus adaptable to various types of electrodes was established for this investigation. Three different electrode gaps and three different electrode materials were tested. For ER fluids, a water‐based Arabic gum ER fluid and a dry‐based polyurethane ER fluid were tested. The field‐dependent yield stresses and current densities were demonstrated under various operating temperatures. In addition, time responses of the ER fluids were experimentally investigated for on–off states of an input electric field and at different operating temperatures. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

Alignment of Polymeric Nanofibers Using a Filtering Effect

One-dimensional nanostructures that play an important role as ideal building blocks for hierarchical assemblies, such as nanowires, nanofibers, and nanotubes, have attracted much attention because of their significance for fundamental investigations and their peculiar electrical, optical, and mechanical properties. In this work, by adding auxiliary parallel electrodes to a previously known electrospinning process, we have developed an electrospinning technology that can achieve the spatial alignment of nanofibers on various types of electrodes. The auxiliary electrodes played an important role as a filter, because any disordered nanofibers that can potentially disrupt the orientation were deposited on them. In addition to their filtering capability, the auxiliary parallel electrodes elongated any nonfiltered nanofibers into a long and straight configuration. Using our method, we have achieved better fiber alignment without the aid of elaborate controls for the flow rate or deposition time.

Erratum to “Effect of water on electrochemical oxygen reduction at the interface between fluorite-type oxide-ion conductors and various types of electrodes” [Journal of Solid State Ionics 174 (2004) 103–109

Erratum to “Effect of water on electrochemical oxygen reduction at the interface between fluorite-type oxide-ion conductors and various types of electrodes” [Journal of Solid State Ionics 174 (2004) 103–109

A novel type ozonizer for wastewater treatment

Barrier discharge represents a widely accepted solution for the generation of ozone employed in wastewater treatment. As the efficiency obtained with the existing devices is rather poor, attempts have been made to use other physical mechanisms. Previous research suggests the possibility of using corona discharge between various types of electrodes and the surface of the water to be treated. Aim of this paper is to evaluate a novel solution, consisting of a multiple-needle type electrode facing an inclined-grounded tray, at the surface of which the water to be treated forms a thin film. The following factors have been found to influence the efficiency of ozone generation: high-voltage level, inter-electrode spacing, thickness of the water layer, angle between the tray and the horizontal plane. The effects of the ozonizer on the quality of several samples of wastewater have been evaluated. The problems to be solved prior to industrial application of this method are discussed.

Effect of water on electrochemical oxygen reduction at the interface between fluorite-type oxide-ion conductors and various types of electrodes

The effect of water vapor addition on the electrochemical oxygen reduction was investigated for the interfaces between fluorite-type oxide-ion conductors (YSZ, ceria) and various types of electrodes at the temperature range 750–1100 K in air. The interface conductivity of YSZ electrolyte/gold electrode at open circuit condition increased when a slight amount of water vapor was added to air at T=865 K. However, the interface conductivity of YSZ/platinum decreased during a long-term exposure in humid atmospheres. The improvement was correlated to the enhancement of oxygen exchange through water molecules, and the degradation is probably due to the blocking of oxygen molecule migration by the adsorbed water molecules.

An approach to durable poly(vinylidene fluoride) thin film loudspeaker

The piezoelectric poly(vinylidene fluoride) (PVDF) surface possessing low surface energy was modified by the ion-assisted-reaction (IAR) method for the application of thin film speaker. The IAR-treated hydrophilic PVDF surface was investigated using atomic force microscopy and x-ray photoelectron spectroscopy. The adhesion strength between various types of electrodes and the film was dramatically improved due to the hydrophilic functional groups, such as –C–O–, –(C=O)–, –(C=O)–O–, and so forth. A durable loudspeaker film was fabricated by enhancing the adhesion between the screen-printed poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate) (PEDOT/PSS) and the modified PVDF films. The PVDF speaker film with the PEDOT/PSS electrode showed higher durability, flatter sound pressure level characteristics, and easier processability compared to metals or indium tin oxide electrodes.

Generation of discharges in dynamic foam for oxidants formation using various types of electrodes

Abstract An innovatory apparatus for the discharge generation in foaming conditions was constructed. The main goal of the research was to obtain various kinds of oxidants, useful in Advanced Oxidation Processes (AOP) in one compact reactor, potentially even in the treated medium. Such an application of dynamic foam, created without the addition of surfactant has not been investigated as yet. To find the optimum conditions for the efficient foam generation and the discharge development and moreover, to assure the presence of oxidants in sufficient concentrations several electrode materials and electrode set-ups were tested. The experiments were done in the metal plate-to-metal plate, metal plate-to-dielectric plate, needles-to-metal plate and needles-to-dielectric plate electrodes’ set-ups. The discharge gap space ranged from 4 mm in the case of plate-to-plate electrodes to 7 mm in the case of needles-to-plate electrodes. Generally, the highest oxidants’ concentrations at the highest comparable gas flow rate were obtained in the needles-to-dielectric plate arrangement, where 521 and 875 ppm of gaseous ozone, 0.36 and 0.5 mg dm −3 of dissolved ozone and 59 and 62 mg dm −3 of hydrogen peroxide were obtained at 14 kV of applied voltage and at 5 dm 3 min −1 of the substrate gas flow in air and oxygen, respectively. The presence of OH radicals was confirmed by the spectroscopic measurements. The larger gap size was more advantageous from the foam formation point of view and the dielectric layer assured more uniform spatial discharge development between the electrodes.

A 5% efficient photoelectrochemical solar cell based on nanostructured ZnO electrodes : Keis, K. et al. Solar Energy Materials and Solar Cells, 2002, 73, (1), 51–58

Photoelectrochemical properties of nanostructured ZnO (wurtzite) electrodes have been investigated. Studies were carried out on various types of electrodes with controlled morphology, particle size and doping. The monochromatic photon-to-current conversion efficiencies were recorded in the UV spectral region on bare ZnO and in the visible region on ruthenium dye-sensitized cells. The results show relatively high efficiencies for such systems and demonstrate the potential of ZnO nanostructured cells as materials for photovoltaic applications.

Dielectric characterization and ionic conductivity of α-LiIO 3 crystals related to the growth conditions

The dielectric response of α-LiIO 3 has been studied at room temperature between 20 Hz and 1 MHz with various types of electrodes and compared to the results in the literature. By changing the sample thickness, a relaxation of space charges is clearly identified and the bulk ionic conductivity is deduced from the admittance diagram. Finally a comparison is carried out between chromium doped and undoped crystals obtained from acid and neutral growth solutions.

Electrode Impedance in Neurophysiologic Recordings: 2. Role in Electromagnetic Interference

ABSTRACT.Electromagnetic interference (EMI) is an important factor in producing a low signal-to-noise ratio during neurophysiologic recordings in electronically hostile environments such as the operating room. Using a controlled EMI generating source, both capacitative and inductive mechanisms of EMI were explored. The effects of electrode type, total electrode impedance, electrode impedance imbalance, inter-electrode distance, and electrode dipole orientation were also explored. The results of these studies indicate that although there are substantial differences in impedance between various types of electrodes, these have a significant but small effect on recorded EMI compared to other factor such as the electrode dipole orientation. From a practical perspective, the use of heterogeneous electrode combinations does not necessarily cause an increase in EMI and (after appropriate testing on an individual basis) may increase recording convenience in specialized environment such as the operating room.