Plate-type Electrodes Research Articles

Removal of Mist Particles by a Two-Stage Electrostatic Precipitator Featuring Plastic Plate Electrodes

To reduce corrosion, cost, and weight, we developed a nonmetallic, two-stage electrostatic precipitator (ESP) using electrodes fabricated from carbon ink and polyethylene terephthalate (a plastic), rather than expensive corrosion-resistant metals. Five collection modules were manufactured; we varied the materials used to fabricate the high-voltage and ground electrodes. The plate-type electrodes of the collection module were made of stainless steel, carbon-coated plastic (CPC), or plastic-coated carbon (PCP). Particle removal performance was investigated by the voltages of the precharger and collection modules, the particle diameter, the airflow rate, and the particle collection area. The particles were an oil mist. The electrode material had little effect on particle removal performance. The experimental performances of two-stage ESPs featuring plastic and carbon plate electrodes met the theoretical efficiencies predicted by the Deutsch equation and Cochet charging theory. Although fluttering developed when the flow velocity exceeded 2 m/s over CPC electrodes, the use of PCP electrodes (the rigidity of which was reinforced by the plastic coatings) eliminated fluttering. Moreover, in an extremely humid condition where the water vapor continuously condensed into water droplets, the polyethylene terephthalate film of the PCP electrode ensured stable operation without spark regardless of humidity or water droplets on the surface. In summary, plastic electrodes were light and economical, while affording high removal efficiencies similar to the removal efficiencies of metals. Moreover, the PCP electrode plastic coating protected the carbon ink from abrasion and corrosion.

Flexible Boron-Doped Diamond (BDD) Electrodes for Plant Monitoring.

Detecting the bio-potential changes of plants would be useful for monitoring their growth and health in the field. A sensitive plant monitoring system with flexible boron-doped diamond (BDD) electrodes prepared from BDD powder and resin (Nafion or Vylon-KE1830) was investigated. The properties of the electrodes were compared with those of small BDD plate-type electrodes by monitoring the bioelectric potentials of potted Aloe and hybrid species in the genus Opuntia. While flexible BDD electrodes have wide potential windows, their cyclic voltammograms are different from those of the BDD plate. Further, the potential gap between a pair of electrodes attached to the plants changes as the plants are stimulated artificially with a finger touch, suggesting that the bioelectric potentials in the plant also changed, manifesting as changes in the potential gap between the electrodes. The BDD electrodes were assessed for their response reproducibility to a finger stimulus for 30 days. It was concluded that the plant monitoring system worked well with flexible BDD electrodes. Further, the electrodes were stable, and as reliable as the BDD plate electrodes in this study. Thus, a flexible and inexpensive BDD electrode system was successfully fabricated for monitoring the bioelectric potential changes in plants.

The Influence of Moisture and Temperature on the Behavior of Soil Resistivity in Earthing Design Using Finite Element Method

<p>Protection of equipment, safety of persons and continuity of power supply are the main objectives of the grounding system. For its accurate design, it is essential to determine the potential distribution on the earth surface and the equivalent resistance of the system. The knowledge of such parameters allows checking the security offered by the grounding system when there is a failure in the power systems.A new method to design an earthing systems using Finite Element Method (FEM) is presented in this article.In this approach, the influence of the moisture and temperature on the behavior of soil resistivity are considered in EARTHING system DESIGN. The earthing system is considered to be a rod electrode and a plate type electrode buried vertically in the ground.The resistance of the system which is a very important factor in the design process is calculated using Finite Element Method. Finite Element Method is used to estimate the solution of the partial differential equation that governs the system behavior. COMSOL Multiphysics 4.4 which is one of the packages that work with the FEM is used as a tool in this design.Finally the values of the resistance obtained by COMSOL Multiphysics are compared with the proven analytical formula values for the ground resistance, in order to prove the work done with COMSOL Multiphysics.</p>

CATHOLYTE-CONDITIONING ENHANCED ELECTROKINETIC REMEDIATION OF Co AND Pb POLLUTED SOIL

The feasibility of catholyte-conditioning to enhance the electrokinetic (EK) remediation of cobalt and lead polluted soil has been investigated in this study. Electrokinetic experiments were conducted using an EK cell 10 cm in width, 10 cm in height, and 50 cm in length. Plate type electrode of graphite was used as electrode material. Two experiments were conducted under constant voltage condition (2 V/cm). The pH values of the soil significantly affect the removal of Co and Pb ions. Due to electrolysis reaction, soil pH increases near the cathode and without pH conditioning, metals precipitate as hydroxides. This problem is solved by the addition of nitric acid (0.1N) in the catholyte compartment. Significant movement of metals was observed through the soil with high removal efficiency. Results showed that catholyte conditioning using nitric acid increased the removal of cobalt and lead from the soil and, consequently, the maximum removal achieved was 73.84% and 62.88% for cobalt and lead, respectively. These EK tests indicate that the increased experimental time induced a higher removal efficiency of cobalt and lead. The results suggest that longer treatment periods will result in further transport of cobalt and lead in the sample. Also, it indicated that the highest quantities of cobalt and lead moved towards the catholyte, particularly at upper 5 cm. On the basis of the experimental results, we conclude that the electrokinetic remediation, using 0.1N HNO3 as catholyte-conditioning, is suitable for extracting cobalt and lead from polluted soil.

Low cost and flexible mesh-based supercapacitors for promising large-area flexible/wearable energy storage

A simple, low cost and efficient flexible sandwich structure supercapacitor is developed using stainless steel mesh as electrode and commercial pen ink as active material by means of a facile and environment-friendly process. The devices show good capacitance performance, such as high specific capacitance, low inner resistance, high energy density and power density, and ultra-long cycle lifetime. The use of mesh and pen ink significantly lower the fabrication cost of supercapacitors which feature light weight and highly flexible characteristics. The stable and robust ink film on mesh electrode makes it fully compatible for conventional carbon material modification to fabricate pseudocapacitors. The comparison between the mesh-type and plate-type electrode supercapacitors certificates the good electrochemical performance of pen ink film and the advantages of mesh-type electrode. The simple dip-coating method is easily scalable for making large-scale flexible and wearable energy storage devices based on mesh and carbon ink.

Long-Term Outcomes of Spinal Cord Stimulation With Percutaneously Introduced Paddle Leads in the Treatment of Failed Back Surgery Syndrome and Lumboischialgia

The study aims to evaluate the long-term clinical and technical efficacy of recently developed percutaneously introducible plate electrodes for spinal cord stimulation. Twenty-one patients diagnosed with failed back surgery syndrome (FBSS) or lumboischialgia were implanted with a small profile plate-type electrode. Patients were followed-up long term and were asked at baseline, after trial, and during each follow-up visit to score their pain on a visual analog scale (VAS) for pain now, worst pain last week, least pain last week, and mean pain last week. Pain location, electrophysiologic parameters, and number of reprogrammings were collected as well. Furthermore, each patient was asked if he/she would redo the procedure post trial and at each of the follow-up visits. A total of 21 patients were prospectively followed up long term. With a mean follow-up of 40.8 months, a significant mean reduction in patient self-reported pain from baseline to postoperative of 75.79% pain reduction was seen at follow-up 1 and 62.52% at follow-up 2. A significant decrease was obtained for, respectively, pain at the present moment, VAS pain worst last week, VAS pain least last week, and VAS pain mean last week in comparison with baseline VAS scores. All patients indicated that they would redo the procedure. Percutaneous implantation of small profile paddle leads in patients with FBSS and lumboischialgia produces favorable results over the long term that are at least comparable with surgical implanted paddle leads. The percutaneous approach also allows nonsurgically trained pain physicians to introduce paddle leads. Indices like if patients would redo the procedure may be more appropriate for analyzing long-term outcomes than the arbitrarily taking 50% reduction in VAS scores.

Effects of Geometry of Electrodes and Pulsating DC Input on Water Splitting for Production of Hydrogen

Electrolytic production of hydrogen from water is gradually gaining its importance among the other conventional processes of hydrogen production in the context of renewable energy source utilization and environmentally clean technology. Worldwide research is being carried out to make the process cost effective. Apart from the different material of construction of electrodes, the geometry is also playing an important role in developing an energy efficient process for electrolytic production of hydrogen. However, no information is available in the literature on this aspect. The aim of this paper is to study the effect of geometry of electrodes on energy efficiency of water electrolysis and rate of hydrogen production. The experimental results using cylindrical electrodes showed the enhancement of the power efficiency of water electrolysis and the rate of production of hydrogen by 30% and 25%, respectively compared to the data obtained using plate type electrodes. Also, the power efficiency of the water electrolyzer was found to improve by 34% using pulsating DC instead of constant DC input.

A hybrid electrohydrodynamic drop-on-demand printing system using a piezoelectric MEMS nozzle

A unique hybrid jetting system based on electrohydrodynamic and piezoelectric forces has been designed to verify the control of the drop velocity and to obtain ultrafine droplets with a high jetting frequency. Piezoelectric nozzles have been fabricated using silicon on insulator wafers and Pyrex glass employing a MEMS process and an anodic bonding process. The plate-type electrode and moving stage were used for the printing process. The droplet ejection mechanisms from the nozzle using the hybrid jetting system were captured by a high-speed camera synchronized with a trigger signal. The deformation of the meniscus and the jetting delay time in regard to the high operational firing frequency were investigated. It was found that controlling the droplet velocity without a change in the droplet volume and obtaining a smaller dot (59 µm in diameter) in hybrid printing mode compared with inkjet printing mode (151 µm in diameter) were possible. These results show this system's promising applicability to the fabrication of micro patterning for a wide range of printed electronics applications.

Influence of Electric Field Application by Reducing Area of Electrode Compared with Cross-Sectional Area of Sludge Bed on Electro-Osmotic Dewatering Process

In the process of electro-osmotic dewatering of a semi-solid sludge put between two plate-type electrodes placed above and below a sludge bed, the water content in part of the bed near the upper electrode opposite to a lower drainage surface is considerably reduced, resulting in electrically poor contact between the upper electrode and the bed being dewatered, and then an excessive increase in electrical contact resistance between them. This obviously obstructs the efficiency of electro-osmotic dewatering throughout the entire bed, and consequently, the continuation of the dewatering process becomes increasingly difficult. From the viewpoint of lowering the influence of increasing electrical contact resistance, the usage of an upper plate-type electrode, in which the area of such electrode is smaller than the cross-sectional area of the sludge bed, is regarded to be practical in improving electro-osmotically the performance of sludge dewatering. In this study, electro-osmotic dewatering is experimentally investigated by reducing the area of not only the upper electrode, but both the upper electrode and the lower one on the drainage surface, and compared with the same-area electrode as the cross-section of the bed. Thus, the influence of such electrode arrangements in reducing the area of the electrode(s) on the dewatering process in terms of water removal and electrical energy consumption is examined using calcium carbonate as solid particles for sludge conditioning. As a result, it has been found that the amount of removed water and electrical energy efficiency for water removal can be increased compared with the same-area electrode as the bed, except for the case of an excessively small electrode area.

Complete degradation of Orange G by electrolysis in sub-critical water

Complete degradation of azo dye Orange G was studied using a 500 mL continuous flow reactor made of SUS 316 stainless steel. In this system, a titanium reactor wall acted as a cathode and a titanium plate-type electrode was used as an anode in a subcritical reaction medium. This hydrothermal electrolysis process provides an environmentally friendly route that does not use any organic solvents or catalysts to remove organic pollutants from wastewater. Reactions were carried out from 30 to 90 min residence times at a pressure of 7 MPa, and at different temperatures of 180–250 °C by applying various direct currents ranging from 0.5 to 1 A. Removal of dye from the product solution and conversion of TOC increased with increasing current value. Moreover, the effect of salt addition on degradation of Orange G and TOC conversion was investigated, because in real textile wastewater, many salts are also included together with dye. Addition of Na 2CO 3 resulted in a massive degradation of the dye itself and complete mineralization of TOC, while NaCl and Na 2SO 4 obstructed the removal of Orange G. Greater than 99% of Orange G was successfully removed from the product solution with a 98% TOC conversion.

Soil water infiltration measurements using electrical impedance tomography

Characterizing hydraulic properties of different types of soils is of great importance for agricultural and geological studies. In situ measurement of soil hydraulic conductivity is a time-consuming task since data has to be recorded at fixed time intervals over a period of minutes or hours depending on the type of soil. Moreover, it is still necessary to use real data for validating models. This paper presents the design of a multimodal infiltrometer which consists of an automated soil infiltration single-ring measurement device and Electrical Impedance Tomography (EIT) data acquisition system. A data logger measures the liquid level change of the 100cm Marriotte-type column, as the water infiltrates at a rate by maintaining a small positive pressure on the water as it moves out of the infiltrometer. A phantom fitted with 16 plate-type electrodes is embedded in the measurement site underneath the water outlet for EIT measurements. The automated infiltrometer data is used for determining soil saturated hydraulic conductivity whereas the EIT measurement system produces images of the water movement through the material below the land surface whose water saturation fluctuates. The equipment was tested in laboratory and in situ trials on four different types of soil (silt loam, clay loam, silty clay and sandy loam) around the Cuitzeo lake watershed (19°58′N, 101°08′W). The results suggest that EIT can be used to image the dynamics of water infiltration of different types of soils, and the automated infiltrometer can provide better information that visually recorded measurements. Thus, a set of images can be used for measuring drainage properties as well. This has important implications for improving computer modelling and soil characterization.

Influence of Electric Field Application with Decreasing One Sided Area of Electrodes on Electro-Osmotic Dewatering

Electro-osmotic dewatering is typically operated under an electric field of direct current condition. In the process of electro-osmotic dewatering, water content in part of the material near the electrode opposite to the drainage surface is locally reduced, resulting in an increase of electrical contact resistance between the electrode and the material being dewatered. Then the efficiency of the electro-osmotic dewatering process is reduced remarkably. In order to improve the performance of electro-osmotic dewatering, it is supposed that a porous plate-type electrode used generally opposite to the drainage surface may be replaced to several rod-type electrodes, which are inserted into the material with dewatering. Using rod-type electrodes, the area of those electrodes becomes smaller than the plate-type electrode. From this point of view, electro-osmotic dewatering was experimentally investigated by decreasing one-sided area of electrodes, namely the area of the plate-type electrode opposite to the drainage surface, and the influence of such an electric field application on improvement of the dewatering process is discussed in this article.

Needleless in vivo gene transfer into muscles by jet injection in combination with electroporation.

Previously, we have established an in vivo electroporation method for gene transfer into muscle by injection of DNA with a needle followed by electric pulse delivery using needle-type electrodes and proved that this method is effective for the systemic delivery of cytokines. To perform the needleless gene delivery, we combined jet injection of DNA with electroporation using plate-type electrodes. For delivery of beta-galactosidase- and enhanced green fluorescent protein (EGFP)-expressing plasmids into muscles, there was no significant difference between the previous needle-mediated method and the newly developed jet-injection method. When pCAGGS-IL-5 was introduced into tibialis anterior, quadricipital and back sural muscles by this new method, the serum IL-5 levels reached 3.4 +/- 0.9, 5.7 +/- 1.7 and 8.4 +/- 2.7 ng/ml at day 5, respectively. Although the peak values of IL-5 achieved by the jet-injection method in these muscles were lower than that of the highest value achieved by needle-mediated gene delivery into anterior tibial muscle, this new method could deliver plasmid into relatively large muscles with better efficiency than the needle-mediated method. Thus the jet-injection method provides a useful means of gene delivery into large muscles, which is essential for future use in human gene therapy.

Collection efficiency of ultrafine particles by an electrostatic precipitator under DC and pulse operating modes

High particle collection efficiency in terms of particle weight volume mg/m/sup 3/ is well achieved by a conventional electrostatic precipitator (ESP). However, the collection efficiencies in terms of number density for the ultrafine (particle size between 0.01 to 0.1 /spl mu/m) or submicron particles by a conventional ESP are still relatively low. Therefore, it is necessary to improve the collection efficiency for ultrafine particles. In this work, attempts have been made to improve the ultrafine particle collection efficiency using the short pulse energizations. The present version of ESP consists of three sets of wire plate type electrodes. For ESP under DC operation modes, experimental results show that the collection efficiency for DC applied voltage decreases with increasing dust loading when particle density is larger than 2.5/spl times/10/sup 10/ part/m/sup 3/. For ESP under pulse operating modes, the particle collection efficiency increases with increasing pulse peak voltage until 25 kV then decreases with increasing pulse peak voltage. The ultrafine particle collection efficiency based on particle density by DC energizations is much higher compared with pulse energizations without DC bias may be due to the reentrainments of ultrafine particles.

Long-term results of peripheral nerve stimulation for reflex sympathetic dystrophy

This prospective, consecutive series describes peripheral nerve stimulation (PNS) for treatment of severe reflex sympathetic dystrophy (RSD) or complex regional pain syndrome, in patients with symptoms entirely or mainly in the distribution of one major peripheral nerve. Plate-type electrodes were placed surgically on affected nerves and tested for 2 to 4 days. Programmable generators were implanted if 50% or more pain reduction and objective improvement in physical changes were achieved. Patients were followed for 2 to 4 years and a disinterested third-party interviewer performed final patient evaluations. Of 32 patients tested, 30 (94%) underwent permanent PNS placement. Long-term good or fair relief was experienced in 19 (63%) of 30 patients. In successfully treated patients, allodynic and spontaneous pain was reduced on a scale of 10 from 8.3 +/- 0.3 preimplantation to 3.5 +/- 0.4 (mean +/- standard error of the mean) at latest follow up (p<0.001). Changes in vasomotor tone and patient activity levels were markedly improved but motor weakness and trophic changes showed less improvement. Six (20%) of the 30 patients undergoing PNS placement returned to part-time or full-time work after being unemployed prestimulator implantation. Initial involvement of more than one major peripheral nerve correlated with a poor or no relief rating (p<0.01). Operative modifications that minimize technical complications are described. This study indicates that PNS can provide good relief for RSD that is limited to the distribution of one major nerve.

Simulation of the tubular positive electrode of the lead-acid battery

The discharge performance of a tubular electrode of the lead-acid battery based on a pseudo steadystate approach was simulated. It was found that the discharge reaction started from the central interior region instead of from the outer surface as in the usual plate-type electrodes. This is due to the fact that the central region has a smaller reaction surface than the outer region of the tubular electrode. This consequently causes a higher current density near the center. A comparison of the theoretical prediction and experimental result shows that the model is fairly accurate except for very high rate discharge conditions.

An improved heat-responsive electrode for the measurement of electrochemical peltier heat: The peltier heat for electrosorption and electrodesorption of oxygen on a platinized platinum electrode in sulfuric acid solution

A new plate-type electrode with high sensitivity and responsive to temperature change was made using a thick film thermistor. The electrochemical Peltier heat for the oxygen surface process at a platinized platinum electrode in 0.5 M H 2SO 4 solution was measured with this electrode by potentiodynamic and galvanostatic transient techniques. It was demonstrated that most of the Peltier heat is caused by the overpotential due to the irreversible oxygen electrode reaction. That is, a Tafel-type relations between the Peltier heat and the current was confirmed. A step-wise heat change corresponding to consecutive stages of platinum lattice occupation by OH was observed. The amount of heat evolved on PtO formation was apparently larger than that on PtOH formation. The results were compared with those obtained by the voltammetric measurement.

Experimental Studies on Epiphyseal Stimulation

1. When two dissimilar metals were joined together and inserted into the metaphyses of the long bones of puppies, ten to fourteen weeks old, as close to the epiphyseal line as possible, stimulation of longitudinal growth was sometimes obtained. This growth was apparently not sustained, however, for it was found only in animals which were sacrificed from one to four months after the operation. The amount of growth obtained varied from one to five millimeters. 2. The animals in which an increase was obtained constituted 36 per cent of all the experimental animals, and if the animals in which epiphyseal damage occurred at the time of insertion are excluded, the percentage rises to 52. Of the dogs in which the larger plate-type electrodes were inserted without resulting epiphyseal damage, 71 per cent showed an increase in length. The most consistent results were obtained with the use of copper and constantan. 3. In some animals the unit was inserted into the growth center itself or into the epiphyseal line. This procedure resulted in shortening of the bone. 4. In one control series of animals the same operation was performed without insertion of the metals. This group showed no uniform increase in growth, although in one animal there was a growth increment of three millimeters. In another series of control animals the ununited metals were inserted into the metaphysis; this group also showed no growth stimulation. It has not been shown that operative trauma or metallic corrosion were directly responsible for any increase in length. 5. The performance of a fibular osteotomy had no effect upon growth under the conditions of this experiment. Comparable growth increments were obtained in the animals with and without osteotomy. 6. A series of children were also subjected to this method of epiphyseal stimulation with no appreciable increase of growth noted. Perhaps this negative result was due to the small mass of the metals employed. No ill effects were noted from these procedures in any patient, but further experimental work must be done before this method is again employed in children. 7. It is felt that the increased growth which was obtained in this study was due to electrolytic stimulation, the intensity of this stimulation varying directly with the surface area of the electrodes employed. No ill effects resulted from the presence of the metals in the dogs, even after four years.