Lead (II) removal from natural soils by enhanced electrokinetic remediation.

Science.gov (United States)

Altin, Ahmet; Degirmenci, Mustafa

2005-01-20

Electrokinetic remediation is a very effective method to remove metal from fine-grained soils having low adsorption and buffering capacity. However, remediation of soil having high alkali and adsorption capacity via the electrokinetic method is a very difficult process. Therefore, enhancement techniques are required for use in these soil types. In this study, the effect of the presence of minerals having high alkali and cation exchange capacity in natural soil polluted with lead (II) was investigated by means of the efficiency of electrokinetic remediation method. Natural soil samples containing clinoptilolite, gypsum and calcite minerals were used in experimental studies. Moreover, a sample containing kaolinite minerals was studied to compare with the results obtained from other samples. Best results for soils bearing alkali and high sorption capacity minerals were obtained upon addition of 3 mol AcH and application of 20 V constant potential after a remediation period of 220 h. In these test conditions, lead (II) removal efficiencies for these samples varied between 60% and 70% up to 0.55 normalized distance. Under the same conditions, removal efficiencies in kaolinite sample varied between 50% and 95% up to 0.9 normalized distance.

Development of complex electrokinetic decontamination method for soil contaminated with uranium

International Nuclear Information System (INIS)

Kim, Gye-Nam; Kim, Seung-Soo; Park, Hye-Min; Kim, Wan-Suk; Moon, Jei-Kwon; Hyeon, Jay-Hyeok

2012-01-01

520L complex electrokinetic soil decontamination equipment was manufactured to clean up uranium contaminated soils from Korean nuclear facilities. To remove uranium at more than 95% from the radioactive soil through soil washing and electrokinetic technology, decontamination experiments were carried out. To reduce the generation of large quantities of metal oxides in cathode, a pH controller is used to control the pH of the electrolyte waste solution between 0.5 and 1 for the formation of UO 2+ . More than 80% metal oxides were removed through pre-washing, an electrolyte waste solution was circulated by a pump, and a metal oxide separator filtered the metal oxide particles. 80–85% of the uranium was removed from the soil by soil washing as part of the pre-treatment. When the initial uranium concentration of the soil was 21.7 Bq/g, the required electrokinetic decontamination time was 25 days. When the initial concentration of 238 U in the soil was higher, a longer decontamination time was needed, but the removal rate of 238 U from the soil was higher.

Pumping $ac$ Josephson current in the Single Molecular Magnets by spin nutation

OpenAIRE

Abdollahipour, B.; Abouie, J.; Rostami, A. A.

2012-01-01

We demonstrate that an {\\it ac} Josephson current is pumped through the Single Molecular Magnets (SMM) by the spin nutation. The spin nutation is generated by applying a time dependent magnetic field to the SMM. We obtain the flowing charge current through the junction by working in the tunneling limit and employing Green's function technique. At the resonance conditions some discontinuities and divergencies are appeared in the normal and Josephson currents, respectively. Such discontinuities...

Electrokinetic Flow in Microchannels with Finite Reservoir Size Effects

International Nuclear Information System (INIS)

Yan, D; Yang, C; Nguyen, N-T; Huang, X

2006-01-01

In electrokinetically-driven microfluidic applications, reservoirs are indispensable and have finite sizes. During operation processes, as the liquid level difference in reservoirs keeps changing as time elapses, the flow characteristics in a microchannel exhibit a combination of the electroosmotic flow and the time-dependent induced backpressure-driven flow. In this work, an assessment of the finite reservoir size effect on electroosmotic flows is presented theoretically and experimentally. A model is developed to describe the timedependent electrokinetic flow with finite reservoir size effects. The theoretical analysis shows that under certain conditions the finite reservoir size effect is significant. The important parameters that describe the effect of finite reservoir size on the flow characteristics are discussed. A new concept denoted as 'effective pumping period' is introduced to characterize the reservoir size effect. The proposed model clearly identifies the mechanisms of the finitereservoir size effects and is further confirmed by using micro-PIV technique. The results of this study can be used for facilitating the design of microfluidic devices

AC electrokinetic drug delivery in dentistry using an interdigitated electrode assembly powered by inductive coupling.

Science.gov (United States)

Ivanoff, Chris S; Wu, Jie Jayne; Mirzajani, Hadi; Cheng, Cheng; Yuan, Quan; Kevorkyan, Stepan; Gaydarova, Radostina; Tomlekova, Desislava

2016-10-01

AC electrokinetics (ACEK) has been shown to deliver certain drugs into human teeth more effectively than diffusion. However, using electrical wires to power intraoral ACEK devices poses risks to patients. The study demonstrates a novel interdigitated electrode arrays (IDE) assembly powered by inductive coupling to induce ACEK effects at appropriate frequencies to motivate drugs wirelessly. A signal generator produces the modulating signal, which multiplies with the carrier signal to produce the amplitude modulated (AM) signal. The AM signal goes through the inductive link to appear on the secondary coil, then rectified and filtered to dispose of its carrier signal, and the positive half of the modulating signal appears on the load. After characterizing the device, the device is validated under light microscopy by motivating carboxylate-modified microspheres, tetracycline, acetaminophen, benzocaine, lidocaine and carbamide peroxide particles with induced ACEK effects. The assembly is finally tested in a common dental bleaching application. After applying 35 % carbamide peroxide to human teeth topically or with the IDE at 1200 Hz, 5 Vpp for 20 min, spectrophotometric analysis showed that compared to diffusion, the IDE enhanced whitening in specular optic and specular optic excluded modes by 215 % and 194 % respectively. Carbamide peroxide absorbance by the ACEK group was two times greater than diffusion as measured by colorimetric oxidation-reduction and UV-Vis spectroscopy at 550 nm. The device motivates drugs of variable molecular weight and structure wirelessly. Wireless transport of drugs to intraoral targets under ACEK effects may potentially improve the efficacy and safety of drug delivery in dentistry.

Design principle for improved three-dimensional ac electro-osmotic pumps

Science.gov (United States)

Burch, Damian; Bazant, Martin Z.

2008-05-01

Three-dimensional (3D) ac electro-osmotic (ACEO) pumps have recently been developed that are much faster and more robust than previous planar designs. The basic idea is to create a “fluid conveyor belt” by placing opposing ACEO slip velocities at different heights. Current designs involve electrodes with electroplated steps, whose heights have been optimized in simulations and experiments. Here, we consider changing the boundary conditions—rather than the geometry—and predict that flow rates can be further doubled by fabricating 3D features with nonpolarizable materials. This amplifies the fluid conveyor belt by removing opposing flows on the vertical surfaces, and it increases the slip velocities that drive the flow.

Electrokinetics in porous media

NARCIS (Netherlands)

Luong, D.T.

2014-01-01

This thesis presents the PhD research on electrokinetics in porous media. Electrokinetic phenomena are induced by the relative motion between a fluid and a solid surface and are directly related to the existence of an electric double layer between the fluid and the solid grain surface.

Laboratory Experiment on Electrokinetic Remediation of Soil

Science.gov (United States)

Elsayed-Ali, Alya H.; Abdel-Fattah, Tarek; Elsayed-Ali, Hani E.

2011-01-01

Electrokinetic remediation is a method of decontaminating soil containing heavy metals and polar organic contaminants by passing a direct current through the soil. An undergraduate chemistry laboratory is described to demonstrate electrokinetic remediation of soil contaminated with copper. A 30 cm electrokinetic cell with an applied voltage of 30…

ELECTROKINETIC REMEDIATION: BASICS AND TECHNOLOGY STATUS

Science.gov (United States)

Electrokinetic remediation, variably named as electrochemical soil processing, electromigration, electrokinetic decontamination or electroreclamation uses electric currents to extract radionuclides, heavy metals, certain organic compounds, or mixed inorganic species and some orga...

Data on flow cell optimization for membrane-based electrokinetic energy conversion

Directory of Open Access Journals (Sweden)

David Nicolas Østedgaard-Munck

2017-12-01

Full Text Available This article elaborates on the design and optimization of a specialized flow cell for the measurement of direct conversion of pressure into electrical energy (Electrokinetic Energy Conversion, EKEC which has been presented in Østedgaard-Munck et al. (2017 [1]. Two main flow cell parameters have been monitored and optimized: A the hydraulic pressure profile on each side of the membrane introduced by pumps recirculating the electrolyte solution through the flow fields and B the electrical resistance between the current collectors across the combined flow cell. The latter parameter has been measured using four-point Electrochemical Impedance spectroscopy (EIS for different flow rates and concentrations. The total cell resistance consists of contributions from different components: the membrane (Rmem, anode charge transfer (RA, cathode charge transfer (RC, and ion diffusion in the porous electrodes (RD.The intrinsic membrane properties of Nafion 117 has been investigated experimentally in LiI/I2 solutions with concentrations ranging between 0.06 and 0.96 M and used to identify the preferred LiI/I2 solution concentration. This was achieved by measuring the solution uptake, internal solution concentration and ion exchange capacity. The membrane properties were further used to calculate the transport coefficients and electrokinetic Figure of merit in terms of the Uniform potential and Space charge models. Special attention has been put on the streaming potential coefficient which is an intrinsic property. Keywords: Electrokinetic energy conversion, Electrochemical flow cell, Conversion efficiency

Electrokinetic Power Generation from Liquid Water Microjets

Energy Technology Data Exchange (ETDEWEB)

Duffin, Andrew M.; Saykally, Richard J.

2008-02-15

Although electrokinetic effects are not new, only recently have they been investigated for possible use in energy conversion devices. We have recently reported the electrokinetic generation of molecular hydrogen from rapidly flowing liquid water microjets [Duffin et al. JPCC 2007, 111, 12031]. Here, we describe the use of liquid water microjets for direct conversion of electrokinetic energy to electrical power. Previous studies of electrokinetic power production have reported low efficiencies ({approx}3%), limited by back conduction of ions at the surface and in the bulk liquid. Liquid microjets eliminate energy dissipation due to back conduction and, measuring only at the jet target, yield conversion efficiencies exceeding 10%.

An electrokinetic pressure sensor

International Nuclear Information System (INIS)

Kim, Dong-Kwon; Kim, Sung Jin; Kim, Duckjong

2008-01-01

A new concept for a micro pressure sensor is demonstrated. The pressure difference between the inlet and the outlet of glass nanochannels is obtained by measuring the electrokinetically generated electric potential. To demonstrate the proposed concept, experimental investigations are performed for 100 nm wide nanochannels with sodium chloride solutions having various concentrations. The proposed pressure sensor is able to measure the pressure difference within a 10% deviation from linearity. The sensitivity of the electrokinetic pressure sensor with 10 −5 M sodium chloride solution is 18.5 µV Pa −1 , which is one order of magnitude higher than that of typical diaphragm-based pressure sensors. A numerical model is presented for investigating the effects of the concentration and the channel width on the sensitivity of the electrokinetic pressure sensor. Numerical results show that the sensitivity increases as the concentration decreases and the channel width increases

Electro-Kinetic Pumping with Slip Irreversibility in Heat Exchange of CSP-Powered Bio-Digester Assemblies

OpenAIRE

Ogedengbe, Emmanuel; Rosen, Marc

2012-01-01

Parametric studies of the effects of slip irreversibility in concentrating solar power (CSP)-powered bio-digester assemblies are investigated. Complexities regarding the identification of the appropriate electro-kinetic phenomena for certain electrolyte phases are reviewed. The application of exergy analysis to the design of energy conversion devices, like solar thermal collectors, for the required heat of formation in a downdraft waste food bio-digester, is discussed. Thermal management in t...

EREM 2001 - 3. symposium and status report on electrokinetic remediation

Energy Technology Data Exchange (ETDEWEB)

Czurda, C.; Haus, R. (eds.); Hoetzl, H.

2001-07-01

Papers have been submitted by authors from around the world, reflecting the worldwide interest in electrokinetic remediation techniques. Therefore the symposium series plays a significant role in the presentation of recent advancements in electrochemical decontamination of polluted sediments on both scientific and technical level. In the field of potential cost-saving, innovative in-situ remediation technologies electrokinetics are already identified throughout the world. The main topics of the symposium are: electrokinetic models, electrokinetic transport processes, technical installation, combination of electroremediation with different remediation methods and the application in various electrokinetic field test demonstrations.

Electrokinetic In Situ Treatment of Metal-Contaminated Soil

Science.gov (United States)

Quinn, Jacqueline; Clausen, Christian A., III; Geiger, Cherie; Reinhart, Debra

2004-01-01

An electrokinetic technique has been developed as a means of in situ remediation of soils, sludges, and sediments that are contaminated with heavy metals. Examples of common metal contaminants that can be removed by this technique include cadmium, chromium, zinc, lead, mercury, and radionuclides. Some organic contaminants can also be removed by this technique. In the electrokinetic technique, a low-intensity direct current is applied between electrodes that have been implanted in the ground on each side of a contaminated soil mass. The electric current causes electro-osmosis and migration of ions, thereby moving aqueous-phase subsurface contaminants from one electrode to the other. The half reaction at the anode yields H+, thereby generating an acid front that travels from the anode toward the cathode. As this acid front passes through a given location, the local increase in acidity increases the solubility of cations that were previously adsorbed on soil particles. Ions are transported towards one electrode or the other which one depending on their respective electric charges. Upon arrival at the electrodes, the ionic contaminants can be allowed to become deposited on the electrodes or can be extracted to a recovery system. Surfactants and other reagents can be introduced at the electrodes to enhance rates of removal of contaminants. Placements of electrodes and concentrations and rates of pumping of reagents can be adjusted to maximize efficiency. The basic concept of electrokinetic treatment of soil is not new. What is new here are some of the details of application and the utilization of this technique as an alternative to other techniques (e.g., flushing or bioremediation) that are not suitable for treating soils of low hydraulic conductivity. Another novel aspect is the use of this technique as a less expensive alternative to excavation: The cost advantage over excavation is especially large in settings in which contaminated soil lies near and/or under

Electrokinetic Particle Transport in Micro-Nanofluidics Direct Numerical Simulation Analysis

CERN Document Server

Qian, Shizhi

2012-01-01

Numerous applications of micro-/nanofluidics are related to particle transport in micro-/nanoscale channels, and electrokinetics has proved to be one of the most promising tools to manipulate particles in micro/nanofluidics. Therefore, a comprehensive understanding of electrokinetic particle transport in micro-/nanoscale channels is crucial to the development of micro/nano-fluidic devices. Electrokinetic Particle Transport in Micro-/Nanofluidics: Direct Numerical Simulation Analysis provides a fundamental understanding of electrokinetic particle transport in micro-/nanofluidics involving elect

Assessment and Comparison of Electrokinetic and Electrokinetic-bioremediation Techniques for Mercury Contaminated Soil

Science.gov (United States)

Azhar, A. T. S.; Nabila, A. T. A.; Nurshuhaila, M. S.; Zaidi, E.; Azim, M. A. M.; Farhana, S. M. S.

2016-11-01

Landfills are major sources of contamination due to the presence of harmful bacteria and heavy metals. Electrokinetic-Bioremediation (Ek-Bio) is one of the techniques that can be conducted to remediate contaminated soil. Therefore, the most prominent bacteria from landfill soil will be isolated to determine their optimal conditions for culture and growth. The degradation rate and the effectiveness of selected local bacteria were used to reduce soil contamination. Hence, this enhances microbiological activities to degrade contaminants in soil and reduce the content of heavy metals. The aim of this study is to investigate the ability of isolated bacteria (Lysinibacillus fusiformis) to remove mercury in landfill soil. 5 kg of landfill soil was mixed with deionized water to make it into slurry condition for the purpose of electrokinetic and bioremediation. This remediation technique was conducted for 7 days by using 50 V/m of electrical gradient and Lysinibacillus fusiformis bacteria was applied at the anode reservoir. The slurry landfill soil was located at the middle of the reservoir while distilled water was placed at the cathode of reservoir. After undergoing treatment for 7 days, the mercury analyzer showed that there was a significant reduction of approximately up to 78 % of mercury concentration for the landfill soil. From the results, it is proven that electrokinetic bioremediation technique is able to remove mercury within in a short period of time. Thus, a combination of Lysinibacillus fusiformis and electrokinetic technique has the potential to remove mercury from contaminated soil in Malaysia.

Electrokinetics and soil decontamination: concepts and overview (Review

Directory of Open Access Journals (Sweden)

Mohammed A. Karim

2014-12-01

Full Text Available Electrokinetic decontamination and extraction have been proven to be one of the most viable, cost effective and emerging techniques in removing contaminants, especially heavy metals from soils for about last five decades. Basic concepts and an overview of the electrokinetic extraction processes and their potential applications in geotechnical and geoenvironmental engineering have been reviewed based on the literature and presented in this paper. Primarily, theoretical and laboratory experimental studies related to electroreclamation of soils are summarised in brief with basic concepts of electrokinetic processes. The paper has been divided into different sections that include history of electrokinetics, background and concepts, modelling, parameter effects, instrumentation, contaminant extraction, field applications, and summary and recommendation. Based on the review it is obvious that the field application of electrokinetic technology to remediate heavy metal contaminated soils /sediments is very limited and site specific. Additional laboratory studies and more pilot- and full-scale information from field applications are critical to the further understanding of the technology and to customize the process in different field conditions.

Theory of electrostatics and electrokinetics of soft particles

Directory of Open Access Journals (Sweden)

Hiroyuki Ohshima

2009-01-01

Full Text Available We investigate theoretically the electrostatics and electrokinetics of a soft particle, i.e. a hard particle covered with an ion-penetrable surface layer of polyelectrolytes. The electric properties of soft particles in an electrolyte solution, which differ from those of hard particles, are essentially determined by the Donnan potential in the surface layer. In particular, the Donnan potential plays an essential role in the electrostatics and electrokinetics of soft particles. Furthermore, the concept of zeta potential, which is important in the electrokinetics of hard particles, loses its physical meaning in the electrokinetics of soft particles. In this review, we discuss the potential distribution around a soft particle, the electrostatic interaction between two soft particles, and the motion of a soft particle in an electric field.

Modeling electrokinetics in ionic liquids: General

Energy Technology Data Exchange (ETDEWEB)

Wang, Chao [Physical and Computational Science Directorate, Pacific Northwest National Laboratory, Richland WA USA; Bao, Jie [Energy and Environment Directorate, Pacific Northwest National Laboratory, Richland WA USA; Pan, Wenxiao [Department of Mechanical Engineering, University of Wisconsin-Madison, Madison WI USA; Sun, Xin [Physical and Computational Science Directorate, Pacific Northwest National Laboratory, Richland WA USA

2017-04-07

Using direct numerical simulations we provide a thorough study on the electrokinetics of ionic liquids. In particular, the modfied Poisson-Nernst-Planck (MPNP) equations are solved to capture the crowding and overscreening effects that are the characteristics of an ionic liquid. For modeling electrokinetic flows in an ionic liquid, the MPNP equations are coupled with the Navier-Stokes equations to study the coupling of ion transport, hydrodynamics, and electrostatic forces. Specifically, we consider the ion transport between two parallel plates, charging dynamics in a 2D straight-walled pore, electro-osmotic ow in a nano-channel, electroconvective instability on a plane ion-selective surface, and electroconvective ow on a curved ion-selective surface. We discuss how the crowding and overscreening effects and their interplay affect the electrokinetic behaviors of ionic liquids in these application problems.

Electrokinetic remediation of copper mine tailings

DEFF Research Database (Denmark)

Hansen, Henrik K.; Rojo, Adrián; Ottosen, Lisbeth M.

2007-01-01

Important process parameters to optimize in electrokinetic soil remediation are those influencing remediation time and power consumption since these directly affect the cost of a remediation action. This work shows how the electrokinetic remediation (EKR) process could be improved by implementing...... bipolar electrodes in the porous material. The bipolar electrodes in EKR meant two improvements: (1) a shorter migration pathway for the contaminant, and (2) an increased electrical conductivity in the remediation system. All together the remediation proceeded faster with lower electrical resistance than...... in similar experiments but without the bipolar electrodes. The new electrokinetic remediation design was tested on copper mine tailings with different applied electric fields, remediation times and pre-treatment. The results showed that the copper removal was increased from 8% (applying 20V for 8 days...

Electrokinetic acceleration of DNA hybridization in microsystems.

Science.gov (United States)

Lei, Kin Fong; Wang, Yun-Hsiang; Chen, Huai-Yi; Sun, Jia-Hong; Cheng, Ji-Yen

2015-06-01

In this work, electrokinetic acceleration of DNA hybridization was investigated by different combinations of frequencies and amplitudes of actuating electric signals. Because the frequencies from low to high can induce different kinds of electrokinetic forces, i.e., electroosmotic to electrothermal forces, this work provides an in-depth investigation of electrokinetic enhanced hybridization. Concentric circular Cr/Au microelectrodes of 350 µm in diameter were fabricated on a glass substrate and probe DNA was immobilized on the electrode surface. Target DNA labeled with fluorescent dyes suspending in solution was then applied to the electrode. Different electrokinetic forces were induced by the application of different electric signals to the circular microelectrodes. Local microfluidic vortexes were generated to increase the collision efficiency between the target DNA suspending in solution and probe DNA immobilized on the electrode surface. DNA hybridization on the electrode surface could be accelerated by the electrokinetic forces. The level of hybridization was represented by the fluorescent signal intensity ratio. Results revealed that such 5-min dynamic hybridization increased 4.5 fold of signal intensity ratio as compared to a 1-h static hybridization. Moreover, dynamic hybridization was found to have better differentiation ability between specific and non-specific target DNA. This study provides a strategy to accelerate DNA hybridization in microsystems. Copyright © 2015 Elsevier B.V. All rights reserved.

Electrokinetic demonstration at the unlined chromic acid pit

International Nuclear Information System (INIS)

Lindgren, E.R.; Hankins, M.G.; Mattson, E.D.; Duda, P.M.

1998-01-01

Heavy-metal contaminated soils are a common problem at Department of Energy (DOE)-operated sites and privately owned facilities throughout the nation. One emerging technology which can remove heavy metals from soil in situ is electrokinetics. To conduct electrokinetic (EK) remediation, electrodes are implanted into the ground, and a direct current is imposed between the electrodes. Metal ions dissolved in the soil pore water migrate towards an electrode where they can be removed. The electrokinetic program at Sandia National Laboratories (SNL) has been focusing on electrokinetic remediation for unsaturated soils. A patent was awarded for an electrokinetic electrode system designed at SNL for applications to unsaturated soils. Current research described in this report details an electrokinetic remediation field demonstration of a chromium plume that resides in unsaturated soil beneath the SNL Chemical Waste Landfill (CWL). This report describes the processes, site investigation, operation and monitoring equipment, testing procedures, and extraction results of the electrokinetic demonstration. This demonstration successfully removed chromium contamination in the form of chromium(VI) from unsaturated soil at the field scale. After 2700 hours of operation, 600 grams of Cr(VI) was extracted from the soil beneath the SNL CWL in a series of thirteen tests. The contaminant was removed from soil which has moisture contents ranging from 2 to 12 weight percent. This demonstration was the first EK field trial to successfully remove contaminant ions from and soil at the field scale. Although the new patented electrode system was successful in removing an anionic contaminant (i.e., chromate) from unsaturated sandy soil, the electrode system was a prototype and has not been specifically engineered for commercialization. A redesign of the electrode system as indicated by the results of this research is suggested for future EK field trials

Application to electrokinetic data to test the adsorption models

International Nuclear Information System (INIS)

Kosmulski, M.; Eriksson, P.; Gustafsson, J.; Rosenholm, J.B.

2000-01-01

The effect of adsorption of Gd(III) on the electrokinetic potential of silica (Aerosil, 390 m 2 /g) was studied at various Gd(III) concentrations (ranging from 10 -6 to 10 -2 mol dm -3 ) and at four different solid to liquid ratios (ranging from 0.05 to 8% of silica by weight). Up to some critical concentration of trivalent cations, their effect on the electrokinetic potential of silica is negligible and the sign is negative over the entire studied pH range. This critical concentration increases when the solid to liquid ratio increases. When Gd(III) concentration exceeds the critical value, the magnitude of the negative electrokinetic potential of silica is reduced. This effect is substantial at pH 6 but it is rather insignificant when the pH is very high (pH > 8) or very low (pH < 4). When the Gd(III) concentration is even higher, the sign of the electrokinetic potential is reversed to positive over certain pH range, which depends on the solid to liquid ratio and Gd(III) concentration. The shape of experimental electrokinetic curves of silica in the presence of trivalent cations often shows maximums and double isoelectric points, thus, it is very complex in comparison with the shape of the percentage of uptake vs. pH curves. Therefore, a test of an adsorption model based on electrokinetic curves is much more demanding than a test based merely on uptake vs. pH curves. The parameters of surface complexation model (SCM) derived from analysis of a large set of uptake curves were used to predict the course of electrokinetic curves. The calculated and experimentally observed maximums and isoelectric points do not exactly match (a difference up to one pH unit), but the model curves qualitatively reflect the trends observed in electrokinetic experiments. (orig.)

AC power supply systems

International Nuclear Information System (INIS)

Law, H.

1987-01-01

An ac power supply system includes a rectifier fed by a normal ac supply, and an inverter connected to the rectifier by a dc link, the inverter being effective to invert the dc output of the receiver at a required frequency to provide an ac output. A dc backup power supply of lower voltage than the normal dc output of the rectifier is connected across the dc link such that the ac output of the rectifier is derived from the backup supply if the voltage of the output of the inverter falls below that of the backup supply. The dc backup power may be derived from a backup ac supply. Use in pumping coolant in nuclear reactor is envisaged. (author)

Electrokinetics of samples treated by electrocoagulation methods

Energy Technology Data Exchange (ETDEWEB)

Angle, C.W.; Donini, J.C.

1992-01-01

The purpose is to study the theory of electrocoagulation during water treatment. Mechanisms proposed in the literature are charge neutralization and dipole-dipole interaction. The electrokinetics of highly concentrated model clay and process clay suspensions, before and after electrocoagulation, are studied experimentally. The charge on treated and untreated dispersions and controls are measured using electrokinetic sonic amplitude and microelectrophoresis techniques. Scanning electron microscopy is used to determine release of aluminum ions onto latex and process clays. The qualitative experimental observations, electrokinetic data, and analysis of aluminum coated particles provide some information on the mechanisms of electrocoagulation, but further studies with dilute dispersions are needed to confirm the charge neutralization mechanism. 10 refs., 4 figs., 3 tabs.

Electrokinetically driven continuous-flow enrichment of colloidal particles by Joule heating induced temperature gradient focusing in a convergent-divergent microfluidic structure.

Science.gov (United States)

Zhao, Cunlu; Ge, Zhengwei; Song, Yongxin; Yang, Chun

2017-09-07

Enrichment of colloidal particles in continuous flow has not only numerous applications but also poses a great challenge in controlling physical forces that are required for achieving particle enrichment. Here, we for the first time experimentally demonstrate the electrokinetically-driven continuous-flow enrichment of colloidal particles with Joule heating induced temperature gradient focusing (TGF) in a microfluidic convergent-divergent structure. We consider four mechanisms of particle transport, i.e., advection due to electroosmosis, electrophoresis, dielectrophoresis and, and further clarify their roles in the particle enrichment. It is experimentally determined and numerically verified that the particle thermophoresis plays dominant roles in enrichment of all particle sizes considered in this study and the combined effect of electroosmosis-induced advection and electrophoresis is mainly to transport particles to the zone of enrichment. Specifically, the enrichment of particles is achieved with combined DC and AC voltages rather than a sole DC or AC voltage. A numerical model is formulated with consideration of the abovementioned four mechanisms, and the model can rationalize the experimental observations. Particularly, our analysis of numerical and experimental results indicates that thermophoresis which is usually an overlooked mechanism of material transport is crucial for the successful electrokinetic enrichment of particles with Joule heating induced TGF.

Electrokinetic-enhanced phytoremediation of soils: status and opportunities.

Science.gov (United States)

Cameselle, Claudio; Chirakkara, Reshma A; Reddy, Krishna R

2013-10-01

Phytoremediation is a sustainable process in which green plants are used for the removal or elimination of contaminants in soils. Both organic and inorganic contaminants can be removed or degraded by growing plants by several mechanisms, namely phytoaccumulation, phytostabilization, phytodegradation, rhizofiltration and rhizodegradation. Phytoremediation has several advantages: it can be applied in situ over large areas, the cost is low, and the soil does not undergo significant damages. However, the restoration of a contaminated site by phytoremediation requires a long treatment time since the remediation depends on the growth and the biological cycles of the plant. It is only applicable for shallow depths within the reach of the roots, and the remediation efficiency largely depends on the physico-chemical properties of the soil and the bioavailability of the contaminants. The combination of phytoremediation and electrokinetics has been proposed in an attempt to avoid, in part, the limitations of phytoremediation. Basically, the coupled phytoremediation-electrokinetic technology consists of the application of a low intensity electric field to the contaminated soil in the vicinity of growing plants. The electric field may enhance the removal of the contaminants by increasing the bioavailability of the contaminants. Variables that affect the coupled technology are: the use of AC or DC current, voltage level and mode of voltage application (continuous or periodic), soil pH evolution, and the addition of facilitating agents to enhance the mobility and bioavailability of the contaminants. Several technical and practical challenges still remain that must be overcome through future research for successful application of this coupled technology at actual field sites. Copyright © 2013 Elsevier Ltd. All rights reserved.

Application to electrokinetic data to test the adsorption models

Energy Technology Data Exchange (ETDEWEB)

Kosmulski, M. [Abo Akademi Univ. (Finland). Dept. of Physical Chemistry; Technical Univ. of Lublin, Dept. of Electrochemistry (Poland); Eriksson, P.; Gustafsson, J.; Rosenholm, J.B. [Abo Akademi Univ. (Finland). Dept. of Physical Chemistry

2000-07-01

The effect of adsorption of Gd(III) on the electrokinetic potential of silica (Aerosil, 390 m{sup 2}/g) was studied at various Gd(III) concentrations (ranging from 10{sup -6} to 10{sup -2} mol dm{sup -3}) and at four different solid to liquid ratios (ranging from 0.05 to 8% of silica by weight). Up to some critical concentration of trivalent cations, their effect on the electrokinetic potential of silica is negligible and the sign is negative over the entire studied pH range. This critical concentration increases when the solid to liquid ratio increases. When Gd(III) concentration exceeds the critical value, the magnitude of the negative electrokinetic potential of silica is reduced. This effect is substantial at pH 6 but it is rather insignificant when the pH is very high (pH > 8) or very low (pH < 4). When the Gd(III) concentration is even higher, the sign of the electrokinetic potential is reversed to positive over certain pH range, which depends on the solid to liquid ratio and Gd(III) concentration. The shape of experimental electrokinetic curves of silica in the presence of trivalent cations often shows maximums and double isoelectric points, thus, it is very complex in comparison with the shape of the percentage of uptake vs. pH curves. Therefore, a test of an adsorption model based on electrokinetic curves is much more demanding than a test based merely on uptake vs. pH curves. The parameters of surface complexation model (SCM) derived from analysis of a large set of uptake curves were used to predict the course of electrokinetic curves. The calculated and experimentally observed maximums and isoelectric points do not exactly match (a difference up to one pH unit), but the model curves qualitatively reflect the trends observed in electokinetic experiments. (orig.)

Potential Electrokinetic Remediation Technologies of Laboratory Scale into Field Application- Methodology Overview

Science.gov (United States)

Ayuni Suied, Anis; Tajudin, Saiful Azhar Ahmad; Nizam Zakaria, Muhammad; Madun, Aziman

2018-04-01

Heavy metal in soil possesses high contribution towards soil contamination which causes to unbalance ecosystem. There are many ways and procedures to make the electrokinetic remediation (EKR) method to be efficient, effective, and potential as a low cost soil treatment. Electrode compartment for electrolyte is expected to treat the contaminated soil through electromigration and enhance metal ions movement. The electrokinetic is applicable for many approaches such as electrokinetic remediation (EKR), electrokinetic stabilization (EKS), electrokinetic bioremediation and many more. This paper presents a critical review on comparison of laboratory scale between EKR, EKS and EK bioremediation treatment by removing the heavy metal contaminants. It is expected to propose one framework of contaminated soil mapping. Electrical Resistivity Method (ERM) is one of famous indirect geophysical tools for surface mapping and subsurface profiling. Hence, ERM is used to mapping the migration of heavy metal ions by electrokinetic.

Washing-electrokinetic Decontamination for Concrete Contaminated with Cobalt and Cesium

International Nuclear Information System (INIS)

Kim, Gye Nam; Yang, Byeong Il; Choi, Wang Kyu; Lee, Kune Woo; Hyeon, Jay Hyeok

2009-01-01

A great volume of radioactive concrete is generated during the operation and the decommissioning of nuclear facilities. The washing-electrokinetic technology in this study, which combined an electrokinetic method and a washing method, was developed to decontaminate the concrete generated in nuclear facilities. The results of only an electrokinetic decontamination for the concrete showed that cobalt was removed to below 1% from the concrete due to its high pH. Therefore, the washing electrokinetic technology was applied to lower the pH of the concrete. Namely, when the concrete was washed with 3 M of hydrochloric acid for 4 hours (0.17 day), the CaCO 3 in the concrete was decomposed into CO 2 and the pH of the concrete was reduced to 3.7, and the cobalt and cesium in the concrete were removed by up to 85.0% and 76.3% respectively. Next, when the washed concrete was decontaminated by the electrokinetic method with 0.01M of acetic acid in the 1L electrokinetic equipment for 14.83 days, the cobalt and the cesium in the concrete were both removed by up to 99.7% and 99.6% respectively. The removal efficiencies of the cobalt and cesium by 0.01M of acetic acid were increased more than those by 0.05M of acetic acid due to the increase of the concrete zeta potential. The total effluent volume generated from the washing-electrokinetic decontamination was 11.55L (7.2ml/g).

On traveling-wave field-effect flow control for simultaneous induced-charge electroosmotic pumping and mixing in microfluidics: physical perspectives and theoretical analysis

Science.gov (United States)

Liu, Weiyu; Ren, Yukun; Tao, Ye; Li, Yanbo; Wu, Qisheng

2018-05-01

Since its first proposition at the end of the last century (Schasfoort et al 1999 Science 286 942-5), field-effect flow control at micrometer dimensions has attracted tremendous attention from the microfluidic community. Most previous research on this subject has mainly focused on enhancing the electroosmotic pump flow rate by introducing an additional in-phase counterionic charge across the diffusing screening cloud with external gate electrodes of static DC voltages. However, there is a flaw, namely that AC fields, which suppress undesirable electrochemical reactions, result in zero time-averaged flow. Starting from this point, we present herein a brand new approach to traveling-wave field-effect electroosmosis control from a theoretical point of view, in the context of a smart manipulation tool for the stratified liquid content of miniaturization systems. In the configuration of a traveling-wave flow field-effect transistor (TW-FFET), the field-induced out-of-phase Debye screening charge within the thin double layer originates from the forward propagation of a traveling potential wave along a discrete arrangement of external gating electrode arrays, which interacts actively with the horizontal standing-wave electric field imposed across the source-drain terminal. Since the voltage waves and induced free charge are all sinusoidal functions of the observation time, the net ICEO flow component can survive in a broad frequency range. Due to the action of the background AC electric field on the inhomogeneous counterionic charge induced at the solution/sidewall interface, asymmetric ICEO vortex patterns appear above the traveling-wave gate arrays, giving rise to simultaneous induced-charge electroosmotic pumping and mixing of fluidic samples. A mathematical model is then developed to numerically investigate the feasibility of TW-FFETs in electrokinetic microflow manipulation. A prototyping paradigm of fully electrokinetics-driven microfabricated fluidic networks in a

Preparation of Janus Particles and Alternating Current Electrokinetic Measurements with a Rapidly Fabricated Indium Tin Oxide Electrode Array.

Science.gov (United States)

Chen, Yu-Liang; Jiang, Hong-Ren

2017-06-23

This article provides a simple method to prepare partially or fully coated metallic particles and to perform the rapid fabrication of electrode arrays, which can facilitate electrical experiments in microfluidic devices. Janus particles are asymmetric particles that contain two different surface properties on their two sides. To prepare Janus particles, a monolayer of silica particles is prepared by a drying process. Gold (Au) is deposited on one side of each particle using a sputtering device. The fully coated metallic particles are completed after the second coating process. To analyze the electrical surface properties of Janus particles, alternating current (AC) electrokinetic measurements, such as dielectrophoresis (DEP) and electrorotation (EROT)- which require specifically designed electrode arrays in the experimental device- are performed. However, traditional methods to fabricate electrode arrays, such as the photolithographic technique, require a series of complicated procedures. Here, we introduce a flexible method to fabricate a designed electrode array. An indium tin oxide (ITO) glass is patterned by a fiber laser marking machine (1,064 nm, 20 W, 90 to 120 ns pulse-width, and 20 to 80 kHz pulse repetition frequency) to create a four-phase electrode array. To generate the four-phase electric field, the electrodes are connected to a 2-channel function generator and to two invertors. The phase shift between the adjacent electrodes is set at either 90° (for EROT) or 180° (for DEP). Representative results of AC electrokinetic measurements with a four-phase ITO electrode array are presented.

Electrokinetic remediation on cadmium (CD) spiked soils

Energy Technology Data Exchange (ETDEWEB)

Sah Jy-Gau [Dept. of Environmental Science and Engineering, National Pingtung Univ. of Science and Technology, Pingtung (Taiwan); Yu Lin, L. [Dept. of Civil and Environmental Engineering, Christian Bros. Univ. Memphis, TN (United States)

2001-07-01

The objective of this study is to examine several variables, such as soil pH, adsorption capacity, fraction of Cd in soils, and organic content for Cd removal in contaminated soil using electrokinetic technology. Two different experimental modules were constructed in the laboratory. In the small module, most Cd was able to move and concentrate at or near the cathode zone in acidic soil and neutral soil under 8 volts after 30 days of electrification. However, the Cd removal efficiency did not improve even when the alkaline soil was soaked in stronger acid solutions. The results indicated that the removal efficiencies were influenced not only by the pH of conducting solutions, but also the pH of the soils. The removal efficiencies of Cd were reduced when a portion of organic peat moss was added into the soils. The increases of organic content in the soils inhibit the removal efficiency in electrokinetic technology. In the larger scale module, the removal efficiency of Cd was lower than that in the smaller module during a short period of time. Nevertheless, the efficiency was improved in the larger module while 16 volts electric pressure and 180 days were applied to the module. The results also showed that the sequence of removal efficiency of the three soils in larger module followed the changes of soil pH. From this study, it concluded that electrokinetic technology has a highly potential to removal Cd in contaminated soils. Within these influence variable studies, the soil pH and organic content are the most important factor in electrokinetic technology. Keywords: Electrokinetic Technique, Heavy Metal, Cd, Soil Remediation. (orig.)

In-Situ Electrokinetic Remediation for Metal Contaminated Soils

Science.gov (United States)

2001-03-01

phytoremediation , and electrokinetic extraction. The US Army Environmental Center (USAEC) and Engineer Research and Development Center (ERDC...California (CA) List Metals: Antimony, arsenic, barium, beryllium, cadmium, chromium, cobalt, copper, lead, mercury , molybdenum, nickel, selenium...Comparison Technologies with which electrokinetic remediation must compete are "Dig and Haul", Soil Washing, and Phytoremediation . "Dig and haul

Hybrid electrokinetic method applied to mix contaminated soil

Energy Technology Data Exchange (ETDEWEB)

Mansour, H.; Maria, E. [Dept. of Building Civil and Environmental Engineering, Concordia Univ., Montreal (Canada)

2001-07-01

Several industrials and municipal areas in North America are contaminated with heavy metals and petroleum products. This mix contamination presents a particularly difficult task for remediation when is exposed in clayey soil. The objective of this research was to find a method to cleanup mix contaminated clayey soils. Finally, a multifunctional hybrid electrokinetic method was investigated. Clayey soil was contaminated with lead and nickel (heavy metals) at the level of 1000 ppm and phenanthrene (PAH) of 600 ppm. Electrokinetic surfactant supply system was applied to mobilize, transport and removal of phenanthrene. A chelation agent (EDTA) was also electrokinetically supplied to mobilize heavy metals. The studies were performed on 8 lab scale electrokinetic cells. The mix contaminated clayey soil was subjected to DC total voltage gradient of 0.3 V/cm. Supplied liquids (surfactant and EDTA) were introduced in different periods of time (22 days, 42 days) in order to optimize the most excessive removal of contaminants. The ph, electrical parameters, volume supplied, and volume discharged was monitored continuously during each experiment. At the end of these tests soil and cathalyte were subjected to physico-chemical analysis. The paper discusses results of experiments including the optimal energy use, removal efficiency of phenanthrene, as well, transport and removal of heavy metals. The results of this study can be applied for in-situ hybrid electrokinetic technology to remediate clayey sites contaminated with petroleum product mixed with heavy metals (e.g. manufacture Gas Plant Sites). (orig.)

Applications and theory of electrokinetic enrichment in micro-nanofluidic chips.

Science.gov (United States)

Chen, Xueye; Zhang, Shuai; Zhang, Lei; Yao, Zhen; Chen, Xiaodong; Zheng, Yue; Liu, Yanlin

2017-09-01

This review reports the progress on the recent development of electrokinetic enrichment in micro-nanofluidic chips. The governing equations of electrokinetic enrichment in micro-nanofluidic chips are given. Various enrichment applications including protein analysis, DNA analysis, bacteria analysis, viruses analysis and cell analysis are illustrated and discussed. The advantages and difficulties of each enrichment method are expatiated. This paper will provide a particularly convenient and valuable reference to those who intend to research the electrokinetic enrichment based on micro-nanofluidic chips.

Electrokinetics on superhydrophobic surfaces

International Nuclear Information System (INIS)

Papadopoulos, Periklis; Deng Xu; Vollmer, Doris; Butt, Hans-Jürgen

2012-01-01

On a superhydrophobic surface a liquid is exposed to a large air-water interface. The reduced wall friction is expected to cause a higher electro-osmotic mobility. On the other hand, the low charge density of a superhydrophobic surface reduces the electro-osmotic mobility. Due to a lack of experimental data it has not been clear so far whether the reduced wall friction or the reduced charge density dominate the electrokinetic mobilities. To separate the relative contributions of electrophoresis and electro-osmosis, the mobilities of colloids on a negatively charged hydrophilic, a superhydrophobic (Cassie) and a partially hydrophilized superhydrophobic (Cassie composite) coating were measured. To vary the charge density as well as its sign with respect to those of the colloids the partially hydrophilized surfaces were coated with polyelectrolytes. We analyzed the electrokinetic mobilities of negatively charged polystyrene colloids dispersed in aqueous medium on porous hydrophilic and superhydrophobic surfaces by confocal laser scanning electron microscopy. In all cases, the external electric field was parallel to the surface. The total electrokinetic mobilities on the superhydrophobic (Cassie) and negatively charged partially hydrophilized (Cassie composite) surfaces were similar, showing that electro-osmosis is small compared to electrophoresis. The positively charged Cassie composite surfaces tend to ‘trap’ the colloids due to attracting electrostatic interactions and rough morphology, reducing the mobility. Thus, either the charge density of the coatings in the Cassie composite state or its slip length is too low to enhance electro-osmosis.

Comparative study of remediation of Cr(VI)-contaminated soil using electrokinetics combined with bioremediation.

Science.gov (United States)

He, Jiaying; He, Chiquan; Chen, Xueping; Liang, Xia; Huang, Tongli; Yang, Xuecheng; Shang, Hai

2018-06-01

The purpose of this research is to design a new bioremediation-electrokinetic (Bio-EK) remediation process to increase treatment efficiency of chromium contamination in soil. Upon residual chromium analysis, it is shown that traditional electrokinetic-PRB system (control) does not have high efficiency (80.26%) to remove Cr(VI). Bio-electrokinetics of exogenous add with reduction bacteria Microbacterium sp. Y2 and electrokinetics can enhance treatment efficiency Cr(VI) to 90.67% after 8 days' remediation. To optimize the overall performance, integrated bio-electrokinetics were designed by synergy with 200 g humic substances (HS) into the systems. According to our results, Cr(VI) (98.33%) was effectively removed via electrokinetics. Moreover, bacteria and humic substances are natural, sustainable, and economical enhancement agents. The research results indicated that the use of integrated bio-electrokinetics is an effective method to remediate chromium-contaminated soils.

A device for reduction of metal oxides generated in electrokinetic separation equipment

International Nuclear Information System (INIS)

Kim, Gye-Nam; Kim, Seung-Soo; Kim, Il-Gook; Jeong, Jung-Whan; Choi, Jong-Won

2015-01-01

For a reduction of waste electrolyte volume and metal oxide volume, the reuse period of the waste electrolyte in the electrokinetic decontamination experiment and the method of a reduction of metal oxide volume in the cathode chamber were drawn out through several experiments with the manufactured 1.2 ton electrokinetic decontamination equipment. The optimum pH of electrolyte in cathode chamber for a reduction of volume of metal oxides was below 2.35. Indoor electrokinetic decontamination equipment for treatment of 1.2 tons of the contaminated soil per batch was manufactured to remove uranium from soil with high removal efficiency during a short time. For a reduction of waste electrolyte volume and metal oxide volume, the reuse period of waste electrolyte in the electrokinetic decontamination experiment and the method of a reduction of metal oxide volume in the cathode chamber were drawn out through several experiments with the manufactured electrokinetic equipment. Indoor electrokinetic decontamination equipment for treatment of 1.2 tons of the contaminated soil was manufactured to remove uranium from soil during a short time

A device for reduction of metal oxides generated in electrokinetic separation equipment

Energy Technology Data Exchange (ETDEWEB)

Kim, Gye-Nam; Kim, Seung-Soo; Kim, Il-Gook; Jeong, Jung-Whan; Choi, Jong-Won [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2015-10-15

For a reduction of waste electrolyte volume and metal oxide volume, the reuse period of the waste electrolyte in the electrokinetic decontamination experiment and the method of a reduction of metal oxide volume in the cathode chamber were drawn out through several experiments with the manufactured 1.2 ton electrokinetic decontamination equipment. The optimum pH of electrolyte in cathode chamber for a reduction of volume of metal oxides was below 2.35. Indoor electrokinetic decontamination equipment for treatment of 1.2 tons of the contaminated soil per batch was manufactured to remove uranium from soil with high removal efficiency during a short time. For a reduction of waste electrolyte volume and metal oxide volume, the reuse period of waste electrolyte in the electrokinetic decontamination experiment and the method of a reduction of metal oxide volume in the cathode chamber were drawn out through several experiments with the manufactured electrokinetic equipment. Indoor electrokinetic decontamination equipment for treatment of 1.2 tons of the contaminated soil was manufactured to remove uranium from soil during a short time.

The improvement of Pilot-scale Electrokinetic for Radioactive Soil Decontamination

International Nuclear Information System (INIS)

Park, Hye Min; Kim, Gye Nam; Kim, Wan Suk; Moon, Jai Kwon

2012-01-01

Most nuclear facility sites have been contaminated by leakage of radioactive waste-solution due to corrosion of the waste-solution tanks and connection pipes by their long-term operation, set up around underground nuclear facilities. Therefore it was needed that the method to remediate a large volume of radioactive soil should be developed. Until now the soil washing method has studied to remediate soil contaminated with uranium, cobalt, cesium, and so on. But it has a lower removal efficiency of nuclide from soils and generated a large volume of waste-solution. And its application to the soil composed of fine particle is impossible. So, the electrokinetic method has been studied as a new technology for soil remediation recently. In this study, the original electrokinetic equipment of 50L suitable to soil contamination characteristics of Korean nuclear facility sites was manufactured for the remediation of soil contaminated with uranium. During experiment with the original electrokinetic equipment, many metal oxides were generated and were stuck on the cathod plate. Several methods to reduce the generation quantity of metal oxides in the electrokinetic equipment and to take off metal oxides from the cathod plate were improved. The soil with uranium was remediated with the improved electrokinetic equipment. The required time to remediate a radioactive soil to under a clearance concentration level was yielded through demonstration experiment with the improved electrokinetic equipment for its different radioactivity concentration

The improvement of Pilot-scale Electrokinetic for Radioactive Soil Decontamination

Energy Technology Data Exchange (ETDEWEB)

Park, Hye Min; Kim, Gye Nam; Kim, Wan Suk; Moon, Jai Kwon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2012-05-15

Most nuclear facility sites have been contaminated by leakage of radioactive waste-solution due to corrosion of the waste-solution tanks and connection pipes by their long-term operation, set up around underground nuclear facilities. Therefore it was needed that the method to remediate a large volume of radioactive soil should be developed. Until now the soil washing method has studied to remediate soil contaminated with uranium, cobalt, cesium, and so on. But it has a lower removal efficiency of nuclide from soils and generated a large volume of waste-solution. And its application to the soil composed of fine particle is impossible. So, the electrokinetic method has been studied as a new technology for soil remediation recently. In this study, the original electrokinetic equipment of 50L suitable to soil contamination characteristics of Korean nuclear facility sites was manufactured for the remediation of soil contaminated with uranium. During experiment with the original electrokinetic equipment, many metal oxides were generated and were stuck on the cathod plate. Several methods to reduce the generation quantity of metal oxides in the electrokinetic equipment and to take off metal oxides from the cathod plate were improved. The soil with uranium was remediated with the improved electrokinetic equipment. The required time to remediate a radioactive soil to under a clearance concentration level was yielded through demonstration experiment with the improved electrokinetic equipment for its different radioactivity concentration

Evaluation of a commercial electro-kinetically pumped sheath-flow nanospray interface coupled to an automated capillary zone electrophoresis system.

Science.gov (United States)

Peuchen, Elizabeth H; Zhu, Guije; Sun, Liangliang; Dovichi, Norman J

2017-03-01

Capillary zone electrophoresis-electrospray ionization-mass spectrometry (CZE-ESI-MS) is attracting renewed attention for proteomic and metabolomic analysis. An important reason for this interest is the maturation and commercialization of interfaces for coupling CZE with ESI-MS. One of these interfaces is an electro-kinetically pumped sheath flow nanospray interface developed by the Dovichi group, in which a very low sheath flow is generated based on electroosmosis within a glass emitter. CMP Scientific has commercialized this interface as the EMASS-II ion source. In this work, we compared the performance of the EMASS-II ion source with our in-house system. The performance of the systems is equivalent. We also coupled the EMASS-II ion source with a PrinCE Next|480 capillary electrophoresis autosampler and an Orbitrap mass spectrometer, and analyzed this system's performance in terms of sensitivity, reproducibility, and separation performance for separation of tryptic digests, intact proteins, and amino acids. The system produced reproducible analysis of BSA digest; the RSDs of peptide intensity and migration time across 24 runs were less than 20 and 6%, respectively. The system produced a linear calibration curve of intensity across a 30-fold range of tryptic digest concentration. The combination of a commercial autosampler and electrospray interface efficiently separated amino acids, peptides, and intact proteins, and only required 5 μL of sample for analysis. Graphical Abstract The commercial and locally constructed versions of the interface provide similar numbers of protein identifications from a Xenopus laevis fertilized egg digest.

Movement of pentachlorophenol in unsaturated soil by electrokinetics

Energy Technology Data Exchange (ETDEWEB)

Harbottle, M.; Sills, G. [Dept. of Engineering Science, Oxford (United Kingdom); Jackman, S. [Dept. of Engineering Science, Oxford (United Kingdom)]|[NERC Centre for Ecology and Hydrology, Oxford (United Kingdom); Thompson, I. [NERC Centre for Ecology and Hydrology, Oxford (United Kingdom)

2001-07-01

Electrokinetic experiments have been performed on unsaturated natural soil specimens artificially contaminated with pentachlorophenol. Movement of pentachlorophenol within the soil mass has been demonstrated, but no contaminant was discovered in any effluent fluids. The results indicate that it may be possible to improve the bioavailability of the pollutant to degradative microorganisms using electrokinetics, by moving the chemical and microbes relative to each others. (orig.)

Transport of radioactive ions in soil by electrokinetics

International Nuclear Information System (INIS)

Buehler, M.F.; Surma, J.E.; Virden, J.W.

1994-10-01

An electrokinetic approach is being evaluated for in situ soil remediation at the Hanford Site in Richland, Washington. This approach uses an applied electric field to induce transport of both radioactive and hazardous waste ions in soil. The work discussed in this paper involves the development of a new method to monitor the movement of the radioactive ions within the soil during the electrokinetic process. A closed cell and a gamma counter were used to provide iii situ measurements of 137 Cs and 60 Co movement in Hanford soil. Preliminary results show that for an applied potential of 200 V over approximately 200 hr, 137 Cs and 60 60 were transported a distance of 4 to 5 in. The monitoring technique demonstrated the feasibility of using electrokinetics for soil separation applications

Modeling electrokinetic transport in phenol contaminated soils

Energy Technology Data Exchange (ETDEWEB)

Zorn, R.; Haus, R.; Czurda, K. [Dept. of Applied Geology, Univ. Karlsruhe (Germany)

2001-07-01

Numerical simulations are compared to laboratory experiments of electroremediation in soils contaminated by phenolic pollutants. The developing pH affects the electrokinetic transport behaviour of phenol. It is found that a water chemistry model must be included in an electrokinetic mass transport model to describe the process of electroremediation more accurately, if no buffering system is used at the electrodes. In the case of controlling the pH at the electrode compartments only a simplified chemical reaction model must be included in the numerical code to match the experimental phenolic transport. (orig.)

Changes in Electrokinetic Coupling Coefficients of Granite under Triaxial Deformation

Directory of Open Access Journals (Sweden)

Osamu Kuwano

2012-01-01

Full Text Available Electrokinetic phenomena are believed to be the most likely origin of electromagnetic signals preceding or accompanying earthquakes. The intensity of the source current due to the electrokinetic phenomena is determined by the fluid flux and the electrokinetic coupling coefficient called streaming current coefficient; therefore, how the coefficient changes before rupture is essential. Here, we show how the electrokinetic coefficients change during the rock deformation experiment up to failure. The streaming current coefficient did not increase before failure, but continued to decrease up to failure, which is explained in terms of the elastic closure of capillary. On the other hand, the streaming potential coefficient, which is the product of the streaming current coefficient and bulk resistivity of the rock, increased at the onset of dilatancy. It may be due to change in bulk resistivity. Our result indicates that the zeta potential of the newly created surface does not change so much from that of the preexisting fluid rock interface.

Recovery of zinc in phosphor wastes via electrokinetic treatments

International Nuclear Information System (INIS)

Yu, M.Y.; Wang, H. Paul; Chen, C.Y.; Hsiung, T.-L.; Wei, Yu-Ling; Tai, H.-S.; Chiang, K.-C.

2007-01-01

Speciation of zinc in phosphor wastes during electrokinetic treatments has been studied by in situ X-ray absorption near edge structure (XANES) spectroscopy in the present work. The least-square fits of the in situ XANES spectra show that the major zinc species in the phosphor waste are ZnS (77%), ZnO (10%), and Zn(OH) 2 (13%). During the electrokinetic treatment for 90 min, 25% of ZnS and 4% of ZnO are dissolved. About 42% of zinc is enriched on the cathode under the electric field (5 V/cm). Prolonging the electrokinetic treatment time to 4 h under the electric field of 5 V/cm, at least 80% of zinc in the phosphor waste can be recovered

High speed capillary zone electrophoresis-mass spectrometry via an electrokinetically pumped sheath flow interface for rapid analysis of amino acids and a protein digest.

Science.gov (United States)

Schiavone, Nicole M; Sarver, Scott A; Sun, Liangliang; Wojcik, Roza; Dovichi, Norman J

2015-06-01

While capillary zone electrophoresis (CZE) has been used to produce very rapid and efficient separations, coupling these high-speed separations with mass spectrometry (MS) has been challenging. Now, with much faster and sensitive mass spectrometers, it is possible to take full advantage of the CZE speed and reconstruct the fast migrating peaks. Here are three high-speed CZE-MS analyses via an electrokinetically pumped sheath-flow interface. The first separation demonstrates CZE-ESI-MS of an amino acid mixture with a 2-min separation, >50,000 theoretical plates, low micromolar concentration detection limits, and subfemtomole mass detection limits (LTQ XL mass spectrometer). The second separation with our recently improved third-generation CE-MS interface illustrates a 20 amino acid separation in ∼7min with an average over 200,000 plate counts, and results in almost-baseline resolution of structural isomers, leucine and isoleucine. The third separation is of a BSA digest with a reproducible CZE separation and mass spectrometry detection in 2min. CZE-MS/MS analysis of the BSA digest identified 31 peptides, produced 52% sequence coverage, and generated a peak capacity of ∼40 across the 1-min separation window (Q-Exactive mass spectrometer). Copyright © 2015 Elsevier B.V. All rights reserved.

An economic evaluation comparison of solar water pumping system with engine pumping system for rice cultivation

Science.gov (United States)

Treephak, Kasem; Thongpron, Jutturit; Somsak, Dhirasak; Saelao, Jeerawan; Patcharaprakiti, Nopporn

2015-08-01

In this paper we propose the design and economic evaluation of the water pumping systems for rice cultivation using solar energy, gasoline fuel and compare both systems. The design of the water and gasoline engine pumping system were evaluated. The gasoline fuel cost used in rice cultivation in an area of 1.6 acres. Under same conditions of water pumping system is replaced by the photovoltaic system which is composed of a solar panel, a converter and an electric motor pump which is compose of a direct current (DC) motor or an alternating current (AC) motor with an inverter. In addition, the battery is installed to increase the efficiency and productivity of rice cultivation. In order to verify, the simulation and economic evaluation of the storage energy battery system with batteries and without batteries are carried out. Finally the cost of four solar pumping systems was evaluated and compared with that of the gasoline pump. The results showed that the solar pumping system can be used to replace the gasoline water pumping system and DC solar pump has a payback less than 10 years. The systems that can payback the fastest is the DC solar pumping system without batteries storage system. The system the can payback the slowest is AC solar pumping system with batteries storage system. However, VAC motor pump of 220 V can be more easily maintained than the motor pump of 24 VDC and batteries back up system can supply a more stable power to the pump system.

Electrokinetic-enhanced bioremediation of organic contaminants: a review of processes and environmental applications.

Science.gov (United States)

Gill, R T; Harbottle, M J; Smith, J W N; Thornton, S F

2014-07-01

There is current interest in finding sustainable remediation technologies for the removal of contaminants from soil and groundwater. This review focuses on the combination of electrokinetics, the use of an electric potential to move organic and inorganic compounds, or charged particles/organisms in the subsurface independent of hydraulic conductivity; and bioremediation, the destruction of organic contaminants or attenuation of inorganic compounds by the activity of microorganisms in situ or ex situ. The objective of the review is to examine the state of knowledge on electrokinetic bioremediation and critically evaluate factors which affect the up-scaling of laboratory and bench-scale research to field-scale application. It discusses the mechanisms of electrokinetic bioremediation in the subsurface environment at different micro and macroscales, the influence of environmental processes on electrokinetic phenomena and the design options available for application to the field scale. The review also presents results from a modelling exercise to illustrate the effectiveness of electrokinetics on the supply electron acceptors to a plume scale scenario where these are limiting. Current research needs include analysis of electrokinetic bioremediation in more representative environmental settings, such as those in physically heterogeneous systems in order to gain a greater understanding of the controlling mechanisms on both electrokinetics and bioremediation in those scenarios. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

In situ soil remediation using electrokinetics

International Nuclear Information System (INIS)

Buehler, M.F.; Surma, J.E.; Virden, J.W.

1994-11-01

Electrokinetics is emerging as a promising technology for in situ soil remediation. This technique is especially attractive for Superfund sites and government operations which contain large volumes of contaminated soil. The approach uses an applied electric field to induce transport of both radioactive and hazardous waste ions in soil. The transport mechanisms include electroosmosis, electromigration, and electrophoresis. The feasibility of using electrokinetics to move radioactive 137 Cs and 60 Co at the Hanford Site in Richland, Washington, is discussed. A closed cell is used to provide in situ measurements of 137 Cs and 60 Co movement in Hanford soil. Preliminary results of ionic movement, along with the corresponding current response, are presented

76 FR 43218 - Commercial and Industrial Pumps

Science.gov (United States)

2011-07-20

.... EERE-2011-BT-STD-0031] RIN 1904-AC54 Commercial and Industrial Pumps AGENCY: Department of Energy... efficient product designs for commercial and industrial pumps. The comment period closed on July 13, 2011... commercial and industrial pumps. The comment period is extended to September 16, 2011. DATES: The comment...

Analysis of antiepileptic drugs in biological fluids by means of electrokinetic chromatography.

Science.gov (United States)

Pucci, Vincenzo; Raggi, Maria Augusta

2005-02-01

An overview of the electrokinetic chromatographic methods for the analysis of antiepileptic drug levels in biological samples is presented. In particular, micellar electrokinetic capillary chromatography is a very suitable method for the determination of these drugs, because it allows a rapid, selective, and accurate analysis. In addition to the electrokinetic chromatographic studies on the determination of antiepileptic drugs, some information regarding sample pretreatment will also be reported: this is a critical step when the analysis of biological fluids is concerned. The electrokinetic chromatographic methods for the determination of recent antiepileptic drugs (e.g., lamotrigine, levetiracetam) and classical anticonvulsants (e.g., carbamazepine, phenytoin, ethosuximide, valproic acid) will be discussed in depth, and their pharmacological profiles will be briefly described as well.

Electrokinetic remediation of fluorine-contaminated soil and its impact on soil fertility.

Science.gov (United States)

Zhou, Ming; Wang, Hui; Zhu, Shufa; Liu, Yana; Xu, Jingming

2015-11-01

Compared to soil pollution by heavy metals and organic pollutants, soil pollution by fluorides is usually ignored in China. Actually, fluorine-contaminated soil has an unfavorable influence on human, animals, plants, and surrounding environment. This study reports on electrokinetic remediation of fluorine-contaminated soil and the effects of this remediation technology on soil fertility. Experimental results showed that electrokinetic remediation using NaOH as the anolyte was a considerable choice to eliminate fluorine in contaminated soils. Under the experimental conditions, the removal efficiency of fluorine by the electrokinetic remediation method was 70.35%. However, the electrokinetic remediation had a significant impact on the distribution and concentrations of soil native compounds. After the electrokinetic experiment, in the treated soil, the average value of available nitrogen was raised from 69.53 to 74.23 mg/kg, the average value of available phosphorus and potassium were reduced from 20.05 to 10.39 mg/kg and from 61.31 to 51.58 mg/kg, respectively. Meanwhile, the contents of soil available nitrogen and phosphorus in the anode regions were higher than those in the cathode regions, but the distribution of soil available potassium was just the opposite. In soil organic matter, there was no significant change. These experiment results suggested that some steps should be taken to offset the impacts, after electrokinetic treatment.

Hybrid electrokinetics for separation, mixing, and concentration of colloidal particles

International Nuclear Information System (INIS)

Sin, Mandy L Y; Shimabukuro, Yusuke; Wong, Pak Kin

2009-01-01

The advent of nanotechnology has facilitated the preparation of colloidal particles with adjustable sizes and the control of their size-dependent properties. Physical manipulation, such as separation, mixing, and concentration, of these colloidal particles represents an essential step for fully utilizing their potential in a wide spectrum of nanotechnology applications. In this study, we investigate hybrid electrokinetics, the combination of dielectrophoresis and electrohydrodynamics, for active manipulation of colloidal particles ranging from nanometers to micrometers in size. A concentric electrode configuration, which is optimized for generating electrohydrodynamic flow, has been designed to elucidate the effectiveness of hybrid electrokinetics and define the operating regimes for different microfluidic operations. The results indicate that the relative importance of electrohydrodynamics increases with decreasing particle size as predicted by a scaling analysis and that electrohydrodynamics is pivotal for manipulating nanoscale particles. Using the concentric electrodes, we demonstrate separation, mixing, and concentration of colloidal particles by adjusting the relative strengths of different electrokinetic phenomena. The effectiveness of hybrid electrokinetics indicates its potential to serve as a generic technique for active manipulation of colloidal particles in various nanotechnology applications.

Selectivity in microemulsion electrokinetic chromatography

DEFF Research Database (Denmark)

Pedersen-Bjergaard, S; Gabel-Jensen, Charlotte; Honoré Hansen, S

2000-01-01

Microemulsion electrokinetic chromatography (MEEKC) is a most promising separation technique providing good selectivity and high separation efficiency of anionic, cationic as well as neutral solutes. In MEEKC lipophilic organic solvents dispersed as tiny droplets in an aqueous buffer by the use...

Fate of zinc in an electroplating sludge during electrokinetic treatments.

Science.gov (United States)

Liu, Shou-Heng; Wang, H Paul

2008-08-01

Chemical structure of zinc in the electrokinetic treatments of an electroplating sludge has been studied by in situ extended X-ray absorption fine structural (EXAFS) and X-ray absorption near edge structural (XANES) spectroscopies in the present work. The least-square fitted XANES spectra indicate that the main zinc compounds in the sludge were ZnCO(3) (75%), ZnOSiO(2) (17%) and Zn(OH)(2) (7%). Zinc in the sludge possessed a Zn-O bond distance of 2.07 A with a coordination number (CN) of 5. In the second shells, the bond distance of Zn-(O)-Si was 3.05 A (CN=2). An increase of Zn-(O)-Si (0.05 A) with a decrease of its CN (from 5 to <1) was found in the early stage of the electrokinetic treatment. Prolong the electrokinetic treatment time to 180 min, about 34% of Zn(II) was dissolved into the aqueous phase and about 68% of Zn(II) in the sludge (or 23% of total zinc) was migrated to the cathode under the electric field (5 V cm(-1)). The dissolution and electromigration rates of Zn(II) in the sludge were 1.0 and 0.6 mmol h(-1)g(-1) sludge, respectively during the electrokinetic treatment. This work also exemplifies the utilization of in situ EXAFS and XANES for revealing speciation and possible reaction pathways during the course of zinc recycling from the sludge by electrokinetic treatments.

Electrokinetic decontamination of concrete

International Nuclear Information System (INIS)

Lomasney, H.L.; SenGupta, A.K.; Yachmenev, V.

1996-01-01

ELECTROSORB Electrokinetic Extraction Technology, developed by ISOTRON Corp., offers a cost-effective approach to treating contaminated concrete. Heavy metals/radionuclides trapped in concrete can be extracted using this process if they are chemically solubilized; solubilizers used are citric acid alone and a mixture of citric and nitric acids. A DC electric field is applied across the contaminated concrete to electrokinetically transport the solubilized contaminants from the concrete pores to a collector on the concrete surface. The collector is an extraction pad laid on the surface. The pad provides confinement for a planar electrode and solubilizer solution; it is operated under a vacuum to hold the pad against the concrete surface. Operation requires little attendance, reducing the workers' health hazards. The process incorporates a mechanism for recycling the solubilizer solution. A field demonstration of the process took place in Building 21 of DOE's Mound facility in Miamisburg, OH, over 12 days in June 1996. The thorium species present in this building's concrete floors included ThO 2 and thorium oxalate. The nitric acid was found to facilitate Th extraction

Effect of electrokinetic remediation on indigenous microbial activity and community within diesel contaminated soil.

Science.gov (United States)

Kim, Seong-Hye; Han, Hyo-Yeol; Lee, You-Jin; Kim, Chul Woong; Yang, Ji-Won

2010-07-15

Electrokinetic remediation has been successfully used to remove organic contaminants and heavy metals within soil. The electrokinetic process changes basic soil properties, but little is known about the impact of this remediation technology on indigenous soil microbial activities. This study reports on the effects of electrokinetic remediation on indigenous microbial activity and community within diesel contaminated soil. The main removal mechanism of diesel was electroosmosis and most of the bacteria were transported by electroosmosis. After 25 days of electrokinetic remediation (0.63 mA cm(-2)), soil pH developed from pH 3.5 near the anode to pH 10.8 near the cathode. The soil pH change by electrokinetics reduced microbial cell number and microbial diversity. Especially the number of culturable bacteria decreased significantly and only Bacillus and strains in Bacillales were found as culturable bacteria. The use of EDTA as an electrolyte seemed to have detrimental effects on the soil microbial activity, particularly in the soil near the cathode. On the other hand, the soil dehydrogenase activity was enhanced close to the anode and the analysis of microbial community structure showed the increase of several microbial populations after electrokinetics. It is thought that the main causes of changes in microbial activities were soil pH and direct electric current. The results described here suggest that the application of electrokinetics can be a promising soil remediation technology if soil parameters, electric current, and electrolyte are suitably controlled based on the understanding of interaction between electrokinetics, contaminants, and indigenous microbial community. Copyright 2010 Elsevier B.V. All rights reserved.

Impact of electrokinetic remediation on microbial communities within PCP contaminated soil

International Nuclear Information System (INIS)

Lear, G.; Harbottle, M.J.; Sills, G.; Knowles, C.J.; Semple, K.T.; Thompson, I.P.

2007-01-01

Electrokinetic techniques have been used to stimulate the removal of organic pollutants within soil, by directing contaminant migration to where remediation may be more easily achieved. The effect of this and other physical remediation techniques on the health of soil microbial communities has been poorly studied and indeed, largely ignored. This study reports the impact on soil microbial communities during the application of an electric field within ex situ laboratory soil microcosms contaminated with pentachlorophenol (PCP; 100 mg kg -1 oven dry soil). Electrokinetics reduced counts of culturable bacteria and fungi, soil microbial respiration and carbon substrate utilisation, especially close to the acidic anode where PCP accumulated (36 d), perhaps exacerbated by the greater toxicity of PCP at lower soil pH. There is little doubt that a better awareness of the interactions between soil electrokinetic processes and microbial communities is key to improving the efficacy and sustainability of this remediation strategy. - Electrokinetics negatively impacted soil

Electrokinetically controlled fluid injection into unicellular microalgae.

Science.gov (United States)

Zhou, Xuewen; Zhang, Xixi; Boualavong, Jonathan; Durney, Andrew R; Wang, Tonghui; Kirschner, Scott; Wentz, Michaela; Mukaibo, Hitomi

2017-10-01

Electrokinetically controlled microinjection is reported as an effective transport mechanism for microinjection into the wild-type strain of the widely studied model microalga Chlamydomonas reinhardtii. A microinjection system using glass capillary pipettes was developed to capture and impale the motile cells. To apply an electric field and induce electrokinetic flow (e.g., electrophoresis and electroosmosis), an electrode was inserted directly into the solution inside the impaling injection pipette and another electrode was inserted into the external cell media. The viability of the impaled cells was confirmed for more than an hour under 0.01 V using the fluorescein diacetate/propidium iodide dual fluorescent dye based assay. The viability was also found to increase almost logarithmically with decreasing voltage and to depend strongly on the solution within the injection pipette. Successful electrokinetic microinjection into cells was confirmed by both an increase in cell volume under an applied voltage and electric field dependent delivery of fluorescent fluorescein molecules into an impaled cell. Our study offers novel opportunities for quantitative delivery of biomolecules into microalgae and advancing the research and development of these organisms as biosynthetic factories. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Electrokinetic treatment of contaminated soils, sludges, and lagoons

International Nuclear Information System (INIS)

Wittle, J.K.; Pamukcu, S.

1993-04-01

The electrokinetic process is an emerging technology for in-situ soil decontamination, in which chemical species, both ionic and nonionic are transported to an electrode site in soil. These products are subsequently removed from the ground via collection systems engineered for each specific application. Electrokinetics refer to movement of water, ions and charged particles relative to one another under the action of an applied direct current electric field. In a porous compact matrix of surface charged particles such as soil, the ion containing pore fluid may be made to flow to collection sites under the applied field. This report describes the effort undertaken to investigate electrokinetically enhanced transport of soil contaminants in synthetic systems. These systems consisted of clay or clay-sand mixtures containing known concentration of a selected heavy metal salt solution or an organic compound. Metals, surrogate radio nuclides and organic compounds evaluated in the program were representatives of those found at a majority of DOE sites. Degree of removal of these metals from soil by the electrokinetic treatment process was assessed through the metal concentration profiles generated across the soil between the electrodes. The best removals, from about 85 to 95% were achieved at the anode side of the soil specimens. Transient pH change had an effect on the metal movement via transient creation of different metal species with different ionic mobilities, as well as changing of the surface characteristics of the soil medium

Marble protection: An inorganic electrokinetic approach

Energy Technology Data Exchange (ETDEWEB)

Meloni, Paola, E-mail: paola.meloni@dimcm.unica.it [Department of Mechanical, Chemical and Materials Engineering (DIMCM), University of Cagliari, Via Marengo 2, 09123 Cagliari (Italy); Manca, Francesco, E-mail: ing.francesco.manca@gmail.com [Department of Mechanical, Chemical and Materials Engineering (DIMCM), University of Cagliari, Via Marengo 2, 09123 Cagliari (Italy); Carcangiu, Gianfranco, E-mail: gcarcan@unica.it [Istituto di Geologia Ambientale e Geoingegneria (IGAG), CNR, Piazza d’Armi, 09123 Cagliari (Italy)

2013-05-15

The influence of an electric potential difference in an aqueous solution was studied as a method for depositing a calcium oxalate coating over a weathered carbonatic stone. Samples of weathered Carrara white marble were treated at 15 and 50 °C for 5 h in an electrokinetic cell, specifically conceived for this study, containing a solution of ammonium oxalate (4% by weight), and were subsequently characterised by scanning electron microscopy, X-ray diffractometry, thermogravimetric analysis and mercury intrusion porosimetry. The electrokinetic treatment proved to be a cost effective and time saving process, able to produce a thick and homogeneous calcium oxalate coating over the stone surface that improves its chemical and physical resistance in low pH environments, and is able to protect the stone from the by-products of urban pollution.

Marble protection: An inorganic electrokinetic approach

Science.gov (United States)

Meloni, Paola; Manca, Francesco; Carcangiu, Gianfranco

2013-05-01

The influence of an electric potential difference in an aqueous solution was studied as a method for depositing a calcium oxalate coating over a weathered carbonatic stone. Samples of weathered Carrara white marble were treated at 15 and 50 °C for 5 h in an electrokinetic cell, specifically conceived for this study, containing a solution of ammonium oxalate (4% by weight), and were subsequently characterised by scanning electron microscopy, X-ray diffractometry, thermogravimetric analysis and mercury intrusion porosimetry. The electrokinetic treatment proved to be a cost effective and time saving process, able to produce a thick and homogeneous calcium oxalate coating over the stone surface that improves its chemical and physical resistance in low pH environments, and is able to protect the stone from the by-products of urban pollution.

Marble protection: An inorganic electrokinetic approach

International Nuclear Information System (INIS)

Meloni, Paola; Manca, Francesco; Carcangiu, Gianfranco

2013-01-01

The influence of an electric potential difference in an aqueous solution was studied as a method for depositing a calcium oxalate coating over a weathered carbonatic stone. Samples of weathered Carrara white marble were treated at 15 and 50 °C for 5 h in an electrokinetic cell, specifically conceived for this study, containing a solution of ammonium oxalate (4% by weight), and were subsequently characterised by scanning electron microscopy, X-ray diffractometry, thermogravimetric analysis and mercury intrusion porosimetry. The electrokinetic treatment proved to be a cost effective and time saving process, able to produce a thick and homogeneous calcium oxalate coating over the stone surface that improves its chemical and physical resistance in low pH environments, and is able to protect the stone from the by-products of urban pollution.

Integrating Electrokinetic and Bioremediation Process for Treating Oil Contaminated Low Permeability Soil

Science.gov (United States)

Ramadan, Bimastyaji Surya; Effendi, Agus Jatnika; Helmy, Qomarudin

2018-02-01

Traditional oil mining activities always ignores environmental regulation which may cause contamination in soil and environment. Crude oil contamination in low-permeability soil complicates recovery process because it requires substantial energy for excavating and crushing the soil. Electrokinetic technology can be used as an alternative technology to treat contaminated soil and improve bioremediation process (biostimulation) through transfer of ions and nutrient that support microorganism growth. This study was conducted using a combination of electrokinetic and bioremediation processes. Result shows that the application of electrokinetic and bioremediation in low permeability soils can provide hydrocarbon removal efficiency up to 46,3% in 7 days operation. The highest amount of microorganism can be found in 3-days operation, which is 2x108 CFU/ml using surfactant as flushing fluid for solubilizing hydrocarbon molecules. Enhancing bioremediation using electrokinetic process is very potential to recover oil contaminated low permeability soil in the future.

Modelling of Electrokinetic Processes in Civil and Environmental Engineering Applications

DEFF Research Database (Denmark)

Paz-Garcia, Juan Manuel; Johannesson, Björn; Ottosen, Lisbeth M.

2011-01-01

conditions are assumed between the aqueous species and the solid matrix for a set of feasible chemical equilibrium reactions defined for each specific application. A module for re-establishing the chemical equilibrium has been developed and included in the system for this purpose. Changes in the porosity......A mathematical model for the electrokinetic phenomena is described. Numerical simulations of different applications of electrokinetic techniques to the fields of civil and environmental engineering are included, showing the versatility and consistency of the model. The electrokinetics phenomena......-Nernst-Planck system of equations, accounting for ionic migration, chemical diffusion and advection is used for modeling the transport process. The advection term contributor is studied by including in the system the water transport through the porous media, mainly due to electroosmosis. The pore solution filling...

Removal of Uranium in Soil Using Large-scale Electrokinetic Decontamination Equipment

Energy Technology Data Exchange (ETDEWEB)

Kim, Gye Nam; Kim, Il gook; Jeong, Jung Whan; Kim, Seung Soo; Choi, Jong Won [KAERI, Daejeon (Korea, Republic of)

2016-05-15

A method to remediate a large volume of radioactive soil should be developed. Until now the soil washing method has been studied to remediate soil contaminated with uranium, cobalt, cesium, and so on. However, it has a lower removal efficiency of nuclide from soils and generated a large volume of waste-solution. In addition, its application to the soil composed of fine particle is impossible. Thus, the electrokinetic method has been studied as a new technology for soil remediation recently. In this study, for a reduction of the waste electrolyte volume, the reuse period of waste electrolyte in the electrokinetic decontamination experiment through several experiments with the manufactured 1.2 ton electrokinetic decontamination equipment. In addition, the time required to reach below the clearance concentration level for self- disposal was estimated through several experiments using the manufactured electrokinetic decontamination equipment. When the initial uranium concentrations in the soils were 7.0-20.0 Bq/g, the times required to reach below the clearance concentration level for self-disposal were 25-40 days with the waste and reclaimed electrolytes.

Application of Electrokinetic Stabilisation (EKS) Method for Soft Soil: A Review

Science.gov (United States)

Azhar, ATS; Azim, MAM; Syakeera, NN; Jefferson, IF; Rogers, CDF

2017-08-01

Soil properties such as low shear strength, excessive compression, collapsing behavior, high swell potential are some of the undesirable properties of soils in geotechnical engineering and those properties would cause severe distress to the structures. To solve these, an innovative stabilization of Electrokinetic (EKS) has been introduced. Electrokinetic is an applicable technique to transport charged particles and fluid in an electric potential. The EKS demonstrates changes in soil pH due to electrolysis reactions, water flow between the electrodes and migration of ions towards the cathode. This treatment has proven its efficiency in consolidating organic, peat and clayey silt as well as less expensive than other methods. Otherwise, this method also gives advantage by not disturbing site. The primary objective of this review is to discuss the application of electrokinetic and to investigate the current knowledge of electrokinetic in geotechnical application through a literature search and review, including consideration of certain aspects related to the soft soil application that may be relevant to the future study and at the same time addressing some key issues and their implications on soil behaviors.

Removal of PAH using electrokinetic transport of biosurfactants in clayey soil

Energy Technology Data Exchange (ETDEWEB)

Maria, E.; Lin, J. [Dept. of Building Civil and Environmental Engineering, Concordia Univ., Montreal (Canada)

2001-07-01

The electrokinetic introduction of non-toxic, biodegradable surfactants (produced ex-situ) to remediate PAH-contaminated soil was investigated. The lab tests demonstrated the possibility of removal of organic contaminants from clayey soil without hazardous impact to the environment. The rhamnolipids (biosurfactants), produced by Pseudomonas aeruginosa to increase the solubility of PAHs into the aqueous phase, were used in the enhancement of electrokinetic remediation. This study determined the potential on-site production of biosurfactants that was directly introduced to soil by means of electrokinetics. The average removal of phenanthrene achieved 74% in the presence of biosurfactants above CMC. The remaining compounds are left for biodegradation. These results contribute to the development of a new remediation technology - bioelectrokinetics. (orig.)

Integrating Electrokinetic and Bioremediation Process for Treating Oil Contaminated Low Permeability Soil

Directory of Open Access Journals (Sweden)

Surya Ramadan Bimastyaji

2018-01-01

Full Text Available Traditional oil mining activities always ignores environmental regulation which may cause contamination in soil and environment. Crude oil contamination in low-permeability soil complicates recovery process because it requires substantial energy for excavating and crushing the soil. Electrokinetic technology can be used as an alternative technology to treat contaminated soil and improve bioremediation process (biostimulation through transfer of ions and nutrient that support microorganism growth. This study was conducted using a combination of electrokinetic and bioremediation processes. Result shows that the application of electrokinetic and bioremediation in low permeability soils can provide hydrocarbon removal efficiency up to 46,3% in 7 days operation. The highest amount of microorganism can be found in 3-days operation, which is 2x108 CFU/ml using surfactant as flushing fluid for solubilizing hydrocarbon molecules. Enhancing bioremediation using electrokinetic process is very potential to recover oil contaminated low permeability soil in the future.

Electrokinetic Stabilisation Method of Soft Clay in Pure System using Electrokinetic Geosynthetic Electrode

Science.gov (United States)

Azhar, A. T. S.; Jefferson, I.; Madun, A.; Abidin, M. H. Z.; Rogers, C. D. F.

2018-04-01

Electrokinetic stabilisation (EKS) method has the ability to solve the problems of soft highly compressibility soil. This study will present the results from an experimental study of EKS on soft soils using inactive kaolinite clay, inert electrode and distilled water (DW) as a pure system mechanism before any chemical stabilisers being used in this research. Therefore, this will provide a baseline study to improve the efficiency of EKS approach. The test model was using inert electrode of Electrokinetic Geosythentic (EKG) developed at the Newcastle University to apply a constant voltage gradient of 50 V/m across a soil sample approximately 400 mm. Distilled water was used at the pore electrolyte fluid compartments supplied under zero hydraulic gradient conditions for the periods of 3, 7 and 14 days. Throughout the monitoring, physical and chemical characteristics were measured. Results from the monitoring data, physical and chemical properties of the pure system showed the development of pH gradient, the changes of electrical conductivity and chemical concentrations with regards to the distance from anode and treatment periods due to the electrochemical effects even though there was no chemical stabilisers were introduced or released from the degradation of electrodes.

Electro-Kinetic Pumping with Slip Irreversibility in Heat Exchange of CSP-Powered Bio-Digester Assemblies

Directory of Open Access Journals (Sweden)

Emmanuel O.B. Ogedengbe

2012-12-01

Full Text Available Parametric studies of the effects of slip irreversibility in concentrating solar power (CSP-powered bio-digester assemblies are investigated. Complexities regarding the identification of the appropriate electro-kinetic phenomena for certain electrolyte phases are reviewed. The application of exergy analysis to the design of energy conversion devices, like solar thermal collectors, for the required heat of formation in a downdraft waste food bio-digester, is discussed. Thermal management in the silicon-based substrate of the energy system is analyzed. The rectangular-shaped micro-channels are simulated with a finite-volume, staggered coupling of the pressure-velocity fields. Entropy generation transport within the energy system is determined and coupled with the solution procedure. Consequently, the effects of channel size perturbation, Reynolds number, and pressure ratios on the thermal performance and exergy destruction are presented. A comparative analysis of the axial heat conduction for thermal management in energy conversion devices is proposed.

Electric double layer and electrokinetic potential of pectic macromolecules in sugar beet

Directory of Open Access Journals (Sweden)

Kuljanin Tatjana A.

2008-01-01

Full Text Available Electrokinetic potential is an important property of colloidal particles and, regarding the fact that it is a well defined and easily measurable property, it is considered to be a permanent characteristic of a particular colloidal system. In fact, it is a measure of electrokinetic charge that surrounds the colloidal particle in a solution and is in direct proportion with the mobility of particles in an electric field. Gouy-Chapman-Stern-Graham's model of electric double layer was adopted and it was proven experimentally that the addition of Cu++ ions to sugar beet pectin caused a reduction in the negative electrokinetic potential proportional to the increase of Cu++ concentration. Higher Cu++ concentrations increased the proportion of cation specific adsorption (Cu++ and H+ with regard to electrostatic Coulombic forces. Consequently, there is a shift in the shear plane between the fixed and diffuse layers directed towards the diffuse layer, i.e. towards its compression and decrease in the electrokinetic potential or even charge inversion of pectin macromolecules.

Citric-acid preacidification enhanced electrokinetic remediation for removal of chromium from chromium-residue-contaminated soil.

Science.gov (United States)

Meng, Fansheng; Xue, Hao; Wang, Yeyao; Zheng, Binghui; Wang, Juling

2018-02-01

Electrokinetic experiments were conducted on chromium-residue-contaminated soils collected from a chemical plant in China. Acidification-electrokinetic remediation technology was proposed in order to solve the problem of removing inefficient with ordinary electrokinetic. The results showed that electrokinetic remediation removal efficiency of chromium from chromium-contaminated soil was significantly enhanced with acidizing pretreatment. The total chromium [Cr(T)] and hexavalent chromium [Cr(VI)] removal rate of the group acidized by citric acid (0.9 mol/L) for 5 days was increased from 6.23% and 19.01% in the acid-free experiments to 26.97% and 77.66% in the acidification-treated experiments, respectively. In addition, part of chromium with the state of carbonate-combined will be converted into water-soluble state through acidification to improve the removal efficiency. Within the appropriate concentration range, the higher concentration of acid was, the more chromium was released. So the removal efficiency of chromium depended on the acid concentration. The citric acid is also a kind of complexing agent, which produced complexation with Cr that was released by the electrokinetic treatment and then enhanced the removal efficiency. The major speciation of chromium that was removed from soils by acidification-electrokinetics remediation was acid-soluble speciation, revivification speciation and oxidation speciation, which reduced biological availability of chromium.

Electrokinetic extraction of chromate from unsaturated soils

International Nuclear Information System (INIS)

Mattson, E.D.; Lindgren, E.R.

1993-01-01

Heavy-metal contamination of soil and groundwater is a widespread problem in industrial nations. Remediation by excavation of such sites may not be cost effective or politically acceptable. Electrokinetic remediation is one possible remediation technique for in situ removal of such contaminants from unsaturated soils. Previous papers discussing the work performed by researchers at Sandia National Laboratories (SNL) and Sat-Unsat, Inc. (SUI) (Lindgren et al., 1991, 1992, 1993) focused on the transport of contaminants and dyes by electrokinetics in unsaturated soils. These experiments were conducted with graphite electrodes with no extraction system. As the contaminants migrated through the soil, they increased in concentration at the electrode creating a diffusion flux in the opposite direction. This paper discusses a technique to remove the contaminants from unsaturated soils once they have reached an electrode

Electrokinetic extraction of chromate from unsaturated soils

Energy Technology Data Exchange (ETDEWEB)

Mattson, E.D. [SAT-UNSAT, Inc., Albuquerque, NM (United States); Lindgren, E.R. [Sandia National Labs., Albuquerque, NM (United States)

1993-11-01

Heavy-metal contamination of soil and groundwater is a widespread problem in industrial nations. Remediation by excavation of such sites may not be cost effective or politically acceptable. Electrokinetic remediation is one possible remediation technique for in situ removal of such contaminants from unsaturated soils. Previous papers discussing the work performed by researchers at Sandia National Laboratories (SNL) and Sat-Unsat, Inc. (SUI) (Lindgren et al., 1991, 1992, 1993) focused on the transport of contaminants and dyes by electrokinetics in unsaturated soils. These experiments were conducted with graphite electrodes with no extraction system. As the contaminants migrated through the soil, they increased in concentration at the electrode creating a diffusion flux in the opposite direction. This paper discusses a technique to remove the contaminants from unsaturated soils once they have reached an electrode.

Electrokinetic enhancement of phenanthrene biodegradation in creosote-polluted clay soil

International Nuclear Information System (INIS)

Niqui-Arroyo, Jose-Luis; Bueno-Montes, Marisa; Posada-Baquero, Rosa; Ortega-Calvo, Jose-Julio

2006-01-01

Given the difficulties caused by low-permeable soils in bioremediation, a new electrokinetic technology is proposed, based on laboratory results with phenanthrene, to afford bioremediation of polycyclic aromatic hydrocarbons (PAH) in clay soils. Microbial activity in a clay soil historically polluted with creosote was promoted using a specially designed electrokinetic cell with a permanent anode-to-cathode flow and controlled pH. The rates of phenanthrene losses during treatment were tenfold higher in soil treated with an electric field than in the control cells without current or microbial activity. Results from experiments with Tenax-assisted desorption and mineralization of 14 C-labeled phenanthrene indicated that phenanthrene biodegradation was limited by mass-transfer of the chemical. We suggest that the enhancement effect of the applied electric field on phenanthrene biodegradation resulted from mobilization of the PAH and nutrients dissolved in the soil fluids. - Electrokinetic bioremediation is a potentially effective technology to treat PAH-polluted, clay-rich soils

[Optimization of electrode configuration in soil electrokinetic remediation].

Science.gov (United States)

Liu, Fang; Fu, Rong-Bing; Xu, Zhen

2015-02-01

Electric field distributions of several different electrode configurations in non-uniform electric field were simulated using MATLAB software, and the electrokinetic remediation device was constructed according to the best electrode configuration. The changes of soil pH and heavy metal residues in different parts of the device during the electrokinetic remediation were also studied. The results showed that, in terms of the effectiveness of the electric field strength, the square (1-D-1) and hexagonal (2-D-3) were the optimal electrode configurations for one-dimensional and two-dimensional respectively and the changes of soil pH, the removal of heavy metals and the distribution of electric field were closely related to one another. An acidic migration band, which could prevent premature precipitation of heavy metals to a certain extent and promote electrokinetic removal of heavy metals, was formed gradually along with the remediation in the whole hexagon device when the cathodic pH was controlled during the remediation of the four cationic metallic ions, Cd2+, Ni2+, Pb2+ and Cu2+. After 480-hour remediation, the total removals of Cd, Ni, Pb and Cu were 86.6%, 86.2%, 67.7% and 73.0%, respectively. Remediation duration and replacement frequency of the electrodes could be adjusted according to the repair target.

Enhanced electrokinetic remediation of lead-contaminated soil by complexing agents and approaching anodes.

Science.gov (United States)

Zhang, Tao; Zou, Hua; Ji, Minhui; Li, Xiaolin; Li, Liqiao; Tang, Tang

2014-02-01

Optimizing process parameters that affect the remediation time and power consumption can improve the treatment efficiency of the electrokinetic remediation as well as determine the cost of a remediation action. Lab-scale electrokinetic remediation of Pb-contaminated soils was investigated for the effect of complexant ethylenediaminetetraacetic acid (EDTA) and acetic acid and approaching anode on the removal efficiency of Pb. When EDTA was added to the catholyte, EDTA dissolved insoluble Pb in soils to form soluble Pb-EDTA complexes, increasing Pb mobility and accordingly removal efficiency. The removal efficiency was enhanced from 47.8 to 61.5 % when the EDTA concentration was increased from 0.1 to 0.2 M, showing that EDTA played an important role in remediation. And the migration rate of Pb was increased to 72.3 % when both EDTA and acetic acid were used in the catholyte. The "approaching anode electrokinetic remediation" process in the presence of both EDTA and acetic acid had a higher Pb-removal efficiency with an average efficiency of 83.8 %. The efficiency of electrokinetic remediation was closely related to Pb speciation. Exchangeable and carbonate-bounded Pb were likely the forms which could be removed. All results indicate that the approaching anode method in the presence of EDTA and acetic acid is an advisable choice for electrokinetic remediation of Pb-contaminated soil.

Electrokinetic treatment of contaminated soils, sludges, and lagoons. Final report

Energy Technology Data Exchange (ETDEWEB)

Wittle, J.K. [Electro-Petroleum, Inc., Wayne, PA (United States); Pamukcu, S. [Lehigh Univ., Bethlehem, PA (United States). Dept. of Civil Engineering

1993-04-01

The electrokinetic process is an emerging technology for in-situ soil decontamination, in which chemical species, both ionic and nonionic are transported to an electrode site in soil. These products are subsequently removed from the ground via collection systems engineered for each specific application. Electrokinetics refer to movement of water, ions and charged particles relative to one another under the action of an applied direct current electric field. In a porous compact matrix of surface charged particles such as soil, the ion containing pore fluid may be made to flow to collection sites under the applied field. This report describes the effort undertaken to investigate electrokinetically enhanced transport of soil contaminants in synthetic systems. These systems consisted of clay or clay-sand mixtures containing known concentration of a selected heavy metal salt solution or an organic compound. Metals, surrogate radio nuclides and organic compounds evaluated in the program were representatives of those found at a majority of DOE sites. Degree of removal of these metals from soil by the electrokinetic treatment process was assessed through the metal concentration profiles generated across the soil between the electrodes. The best removals, from about 85 to 95% were achieved at the anode side of the soil specimens. Transient pH change had an effect on the metal movement via transient creation of different metal species with different ionic mobilities, as well as changing of the surface characteristics of the soil medium.

A new electrokinetic technology for revitalization of oily sludge

Energy Technology Data Exchange (ETDEWEB)

Habibi, S.

2004-07-01

Oily sludge is a mixture of hydrocarbons, water, metals and suspended fine solids. The petroleum industry is faced with the challenge of handling large volumes of such sludge whose properties depend on the nature of the crude oil, the processing capacity, the down-stream capacities and the design of effluent treatment plants. The management of oily sludge is both complicated and costly due to its complex composition. For that reason, this study developed a method to improve the separation of phases to allow for greater reuse of oily sludge. The study focused on the use of electrokinetic phenomena for the remediation of oily sludge. An amphoteric surfactant was used to evaluate the effect of surfactant on the electrokinetic mobilization or organic contaminants in oily sludge. A series of electrokinetic cell tests were conducted with varying electrical potentials for a 32 day period. Electrical parameters were measured on a daily basis and samples were collected at specific time intervals for UV/VIS and FTIR analysis. The study involved a range of electrokinetic processes such as electrocoagulation, electro-coalescence, desorption, electrophoresis and electro-osmosis. Study results were used to evaluate the thermodynamics of the proposed process and new theories on the behaviour of colloidal components of oily sludge were derived. The study indicated that there is an excellent separation of water, hydrocarbon and solid phases. Since the recovered solid phase has a high hydrocarbon content, it can be recycled for other processes. Some of the volatile hydrocarbons that were released during the process can also be captured and burned as a fuel. The separated water had a low concentration of hydrocarbon and could be sent to wastewater treatment plants.

Hybrid immersed interface-immersed boundary methods for AC dielectrophoresis

International Nuclear Information System (INIS)

Hossan, Mohammad Robiul; Dillon, Robert; Dutta, Prashanta

2014-01-01

Dielectrophoresis, a nonlinear electrokinetic transport mechanism, has become popular in many engineering applications including manipulation, characterization and actuation of biomaterials, particles and biological cells. In this paper, we present a hybrid immersed interface–immersed boundary method to study AC dielectrophoresis where an algorithm is developed to solve the complex Poisson equation using a real variable formulation. An immersed interface method is employed to obtain the AC electric field in a fluid media with suspended particles and an immersed boundary method is used for the fluid equations and particle transport. The convergence of the proposed algorithm as well as validation of the hybrid scheme with experimental results is presented. In this paper, the Maxwell stress tensor is used to calculate the dielectrophoretic force acting on particles by considering the physical effect of particles in the computational domain. Thus, this study eliminates the approximations used in point dipole methods for calculating dielectrophoretic force. A comparative study between Maxwell stress tensor and point dipole methods for computing dielectrophoretic forces are presented. The hybrid method is used to investigate the physics of dielectrophoresis in microfluidic devices using an AC electric field. The numerical results show that with proper design and appropriate selection of applied potential and frequency, global electric field minima can be obtained to facilitate multiple particle trapping by exploiting the mechanism of negative dielectrophoresis. Our numerical results also show that electrically neutral particles form a chain parallel to the applied electric field irrespective of their initial orientation when an AC electric field is applied. This proposed hybrid numerical scheme will help to better understand dielectrophoresis and to design and optimize microfluidic devices

Secondary side TSP deposit buildup: lab test investigation focused on electrokinetic considerations

International Nuclear Information System (INIS)

Barale, M.; Guillodo, M.; Foucault, M.; Ryckelynck, N.; Clinard, M-H.; Chahma, F.; Brun, C.; Corredera, G.

2010-01-01

Deposit buildup which caused the clogging of the 'foils' of the upper tube-support-plates (TSP) inside a PWR steam generator of French NPPs in 2006 presents certain similarities with deposits observed in lab tests performed in secondary coolant chemistry at the Technical Centre of AREVA NP in 2002. The mechanism of TSP clogging seems not to present obvious phenomenological links with the fouling of the free span of SG since deposits buildup is quite uniform and is currently related to a surface boiling effect due to the surface heat flux. A specific mechanism could account for TSP clogging. In particular, electrokinetic effects were investigated by EDF-CEIDRE and AREVA NP SAS in the framework of a lab test program started in 2007. The electrokinetic approach is to consider that the coupling of local hydrodynamic and surface electrochemistry could lead to the formation of a very localized and heterogeneous deposit at the leading edge between both TSP and SG tubing material. Electrokinetic effects can lead to the oxidation and/or the precipitation of ferrous ions and to a variation of the electrokinetic potential which can produce strong attraction of iron oxide colloids. These electrokinetic effects are dependent of the T/H and local hydrodynamic conditions and surface electrochemistry explaining. The objective of this EDF-AREVA lab test program is to investigate the role of secondary chemistry coolant (pH, DH, N 2 H 4 , amine, redox) and of the nature of materials (SS, Ni base alloy) on deposit buildup. Properties of oxide surface and zeta potential of oxidized metallic materials have been also determined at temperature to understand their potential contribution on mechanism of TSP clogging in secondary side chemistry coolant. In this paper, a set of specific experiments carried out in this frame have been presented and discussed, paying particular attention to the effects of electrokinetic considerations and surface charges at oxide-solution interfaces

Secondary side TSP deposit buildup: lab test investigation focused on electrokinetic considerations

Energy Technology Data Exchange (ETDEWEB)

Barale, M.; Guillodo, M.; Foucault, M., E-mail: Morgan.Barale@areva.com [AREVA NP SAS, Technical Centre, Le Creusot (France); Ryckelynck, N.; Clinard, M-H.; Chahma, F.; Brun, C. [AREVA NP SAS, Chemistry and Radiochemistry Group, Paris (France); Corredera, G. [Electricite de France, Centre d' Expertise et d' Inspection dans les domaines de la Realisation et de l' Exploitation, Saint-Denis (France)

2010-07-01

Deposit buildup which caused the clogging of the 'foils' of the upper tube-support-plates (TSP) inside a PWR steam generator of French NPPs in 2006 presents certain similarities with deposits observed in lab tests performed in secondary coolant chemistry at the Technical Centre of AREVA NP in 2002. The mechanism of TSP clogging seems not to present obvious phenomenological links with the fouling of the free span of SG since deposits buildup is quite uniform and is currently related to a surface boiling effect due to the surface heat flux. A specific mechanism could account for TSP clogging. In particular, electrokinetic effects were investigated by EDF-CEIDRE and AREVA NP SAS in the framework of a lab test program started in 2007. The electrokinetic approach is to consider that the coupling of local hydrodynamic and surface electrochemistry could lead to the formation of a very localized and heterogeneous deposit at the leading edge between both TSP and SG tubing material. Electrokinetic effects can lead to the oxidation and/or the precipitation of ferrous ions and to a variation of the electrokinetic potential which can produce strong attraction of iron oxide colloids. These electrokinetic effects are dependent of the T/H and local hydrodynamic conditions and surface electrochemistry explaining. The objective of this EDF-AREVA lab test program is to investigate the role of secondary chemistry coolant (pH, DH, N{sub 2}H{sub 4}, amine, redox) and of the nature of materials (SS, Ni base alloy) on deposit buildup. Properties of oxide surface and zeta potential of oxidized metallic materials have been also determined at temperature to understand their potential contribution on mechanism of TSP clogging in secondary side chemistry coolant. In this paper, a set of specific experiments carried out in this frame have been presented and discussed, paying particular attention to the effects of electrokinetic considerations and surface charges at oxide

Experimental study and mathematical model on remediation of Cd spiked kaolinite by electrokinetics

International Nuclear Information System (INIS)

Mascia, Michele; Palmas, Simonetta; Polcaro, Anna Maria; Vacca, Annalisa; Muntoni, Aldo

2007-01-01

An experimental study on electrokinetic removal of cadmium from kaolinitic clays is presented in this work, which is aimed to investigate the effect of surface reactions on the electrokinetic process. Enhanced electrokinetic tests were performed in which the pH of the compartments was controlled. Cadmium spiked kaolin was adopted in the experimental runs. On the basis of the experimental results, a numerical model was formulated to simulate the cadmium (Cd) transport under an electric field by combining a one-dimensional diffusion-advection model with a geochemical model: the combined model describes the contaminant transport driven by chemical and electrical gradients, as well as the effect of the surface reactions. The geochemical model utilized parameters derived from the literature, and it was validated by experimental data obtained by sorption and titration experiments. Electrokinetic tests were utilized to validate the results of the proposed model. A good prediction of the behaviour of the soil/cadmium ions system under electrical field was obtained: the differences between experimental and model predicted profiles for the species considered were less than 5% in all the examined conditions

Influence of temperature and hydraulic conductivity of soil on electrokinetic decontamination

International Nuclear Information System (INIS)

Kim, Gye-Nam; Kim, Seung-Soo; Jeong, Jung-Whan; Choi, Jong-Won

2016-01-01

The electrokinetic process holds great promise for the decontamination of contaminated soil because it has a high removal efficiency and is time-effective for low permeability. Electrokinetic decontamination can be used to treat soil contaminated with inorganic species and radionuclides. The main mechanisms of a contaminant's movement in an electrical field involved in electrokinetic technology are the electro-migration of the ionic species and electro-osmosis. Electro-migration probably contributes significantly to the removal of contaminants, especially at high concentrations of ionic contaminants and/or a high hydraulic permeability of soil. The cathode reaction should be depolarized to avoid the generation of hydroxides and their transport in soil. The selected liquid, also known as a purging reagent, should induce favorable pH conditions in soil, and/or interact with the incorporated heavy metals so that these heavy metals are removed from the soil. The removal efficiencies of uranium from contaminated soil in manufactured laboratory electrokinetic decontamination equipment were proportional to the elapsed time. The removal efficiencies of uranium for 2 days were 77-87%. In addition, the removal efficiencies according to the elapsed time after 2 days were reduced. When 75, 80, and 85℃ electrolyte temperatures in the cathode chamber were applied, the time required for the removal efficiency of uranium to reach 92% was 6, 5 and 4 days

Influence of temperature and hydraulic conductivity of soil on electrokinetic decontamination

Energy Technology Data Exchange (ETDEWEB)

Kim, Gye-Nam; Kim, Seung-Soo; Jeong, Jung-Whan; Choi, Jong-Won [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2016-10-15

The electrokinetic process holds great promise for the decontamination of contaminated soil because it has a high removal efficiency and is time-effective for low permeability. Electrokinetic decontamination can be used to treat soil contaminated with inorganic species and radionuclides. The main mechanisms of a contaminant's movement in an electrical field involved in electrokinetic technology are the electro-migration of the ionic species and electro-osmosis. Electro-migration probably contributes significantly to the removal of contaminants, especially at high concentrations of ionic contaminants and/or a high hydraulic permeability of soil. The cathode reaction should be depolarized to avoid the generation of hydroxides and their transport in soil. The selected liquid, also known as a purging reagent, should induce favorable pH conditions in soil, and/or interact with the incorporated heavy metals so that these heavy metals are removed from the soil. The removal efficiencies of uranium from contaminated soil in manufactured laboratory electrokinetic decontamination equipment were proportional to the elapsed time. The removal efficiencies of uranium for 2 days were 77-87%. In addition, the removal efficiencies according to the elapsed time after 2 days were reduced. When 75, 80, and 85℃ electrolyte temperatures in the cathode chamber were applied, the time required for the removal efficiency of uranium to reach 92% was 6, 5 and 4 days.

Principles of Micellar Electrokinetic Capillary Chromatography Applied in Pharmaceutical Analysis

Directory of Open Access Journals (Sweden)

Árpád Gyéresi

2013-02-01

Full Text Available Since its introduction capillary electrophoresis has shown great potential in areas where electrophoretic techniques have rarely been used before, including here the analysis of pharmaceutical substances. The large majority of pharmaceutical substances are neutral from electrophoretic point of view, consequently separations by the classic capillary zone electrophoresis; where separation is based on the differences between the own electrophoretic mobilities of the analytes; are hard to achieve. Micellar electrokinetic capillary chromatography, a hybrid method that combines chromatographic and electrophoretic separation principles, extends the applicability of capillary electrophoretic methods to neutral analytes. In micellar electrokinetic capillary chromatography, surfactants are added to the buffer solution in concentration above their critical micellar concentrations, consequently micelles are formed; micelles that undergo electrophoretic migration like any other charged particle. The separation is based on the differential partitioning of an analyte between the two-phase system: the mobile aqueous phase and micellar pseudostationary phase. The present paper aims to summarize the basic aspects regarding separation principles and practical applications of micellar electrokinetic capillary chromatography, with particular attention to those relevant in pharmaceutical analysis.

Recent Progress and Perspectives in the Electrokinetic Characterization of Polyelectrolyte Films

Directory of Open Access Journals (Sweden)

Ralf Zimmermann

2015-12-01

Full Text Available The analysis of the charge, structure and molecular interactions of/within polymeric substrates defines an important analytical challenge in materials science. Accordingly, advanced electrokinetic methods and theories have been developed to investigate the charging mechanisms and structure of soft material coatings. In particular, there has been significant progress in the quantitative interpretation of streaming current and surface conductivity data of polymeric films from the application of recent theories developed for the electrohydrodynamics of diffuse soft planar interfaces. Here, we review the theory and experimental strategies to analyze the interrelations of the charge and structure of polyelectrolyte layers supported by planar carriers under electrokinetic conditions. To illustrate the options arising from these developments, we discuss experimental and simulation data for plasma-immobilized poly(acrylic acid films and for a polyelectrolyte bilayer consisting of poly(ethylene imine and poly(acrylic acid. Finally, we briefly outline potential future developments in the field of the electrokinetics of polyelectrolyte layers.

Electrokinetic demonstration at Sandia National Laboratories: Use of transference numbers for site characterization and process evaluation

International Nuclear Information System (INIS)

Lindgren, E.R.; Mattson, E.D.

1997-01-01

Electrokinetic remediation is generally an in situ method using direct current electric potentials to move ionic contaminants and/or water to collection electrodes. The method has been extensively studied for application in saturated clayey soils. Over the past few years, an electrokinetic extraction method specific for sandy, unsaturated soils has been developed and patented by Sandia National Laboratories. A RCRA RD ampersand D permitted demonstration of this technology for the in situ removal of chromate contamination from unsaturated soils in a former chromic acid disposal pit was operated during the summer and fall of 1996. This large scale field test represents the first use of electrokinetics for the removal of heavy metal contamination from unsaturated soils in the United States and is part of the US EPA Superfund Innovative Technology Evaluation (SITE) Program. Guidelines for characterizing a site for electrokinetic remediation are lacking, especially for applications in unsaturated soil. The transference number of an ion is the fraction of the current carried by that ion in an electric field and represents the best measure of contaminant removal efficiency in most electrokinetic remediation processes. In this paper we compare the transference number of chromate initially present in the contaminated unsaturated soil, with the transference number in the electrokinetic process effluent to demonstrate the utility of evaluating this parameter

Surfactant-enhanced electrokinetic remediation of soil contaminated with hydrocarbons

Energy Technology Data Exchange (ETDEWEB)

Yang, J.W.; Park, J.Y.; Lee, H.H.; Cho, H.J. [Dept. of Chemical Engineering, Korea Advanced Inst. of Science and Technology, Taejon (Korea)

2001-07-01

Removal of hydrophobic organic contaminants (HOCs) using electrokinetic method was studied in a model system. Kaolinite and phenanthrene were selected as the model clay soil and representative HOC. Three different types of surfactants, APG (alkyl polyglucoside), Brij30 (polyoxyethylene 4 lauryl ether), and SDS (sodium dodecyl sulfate), were used to enhance the solubility of HOCs. Electrokinetic (EK) column experiments were performed using water, surfactant solution, and acetate buffer solution under a constant current condition. Voltage and flow through the soil system were interpreted with time. Electrolyte pH at the anode and cathode compartments was observed for operation time. Removal efficiency of phenanthrene was examined after the end of EK operation during 2, 4, and 6 weeks. (orig.)

2-D model for electrokinetic remediation

Energy Technology Data Exchange (ETDEWEB)

Rodriguez Maroto, J.M.; Garcia Delgado, R.A.; Gomez Lahoz, C.; Garcia Herruzo, F. [Dept. de Ingenieria Quimica, Univ. de Malaga (Spain); Vereda Alonso, C. [Dept. de Ingenieria Quimica, Univ. de Malaga (Spain)]|[Inst. for Geologi and Geoteknik, Danmarks Tekniske Univ., Lyngby (Denmark)

2001-07-01

A simple two-dimensional numerical model is presented in this work. In this case, the model is used to examine the enhanced method of the electrokinetic remediation technique in a 2-D arrangement. Nevertheless the model with minor changes can also be used to study the effect of the electrode configuration in the performance of this technique. (orig.)

Analytical theory and possible detection of the ac quantum spin Hall effect.

Science.gov (United States)

Deng, W Y; Ren, Y J; Lin, Z X; Shen, R; Sheng, L; Sheng, D N; Xing, D Y

2017-07-11

We develop an analytical theory of the low-frequency ac quantum spin Hall (QSH) effect based upon the scattering matrix formalism. It is shown that the ac QSH effect can be interpreted as a bulk quantum pumping effect. When the electron spin is conserved, the integer-quantized ac spin Hall conductivity can be linked to the winding numbers of the reflection matrices in the electrodes, which also equal to the bulk spin Chern numbers of the QSH material. Furthermore, a possible experimental scheme by using ferromagnetic metals as electrodes is proposed to detect the topological ac spin current by electrical means.

Feedback-controlled electro-kinetic traps for single-molecule ...

Indian Academy of Sciences (India)

2014-01-11

Jan 11, 2014 ... limited residence time of a given molecule within the detection volume. A common ... information on individual folding pathways, as well as to the internal dynamics between ..... Essentials for building an electro-kinetic trap.

Electrokinetic remediation of contaminated soils

International Nuclear Information System (INIS)

Lindgren, E.R.; Kozak, M.W.; Mattson, E.D.

1991-01-01

Electrokinetic remediation of contaminated soil has been demonstrated for saturated and unsaturated sand in preliminary experiments using a novel transport visualization technique. Large anionic organic dyes were mixed with a portion of soil and the rate of electromigration of the dye in an imposed electric field was monitored photographically. One of the fastest current-normalized electromigration rates was measured in the driest sand, which contained 7% water by weight. This moisture content is typical of the moisture content in the unsaturated zone of subsurface native soils found in New Mexico. The characteristics of the electromigration were similar in both the saturated and unsaturated sand. The leading edge of the dye migration front was diffuse while the trailing edge was sharp and concentrated. This and other observed behavior may indicate a concentration effect, where the electromigration rate of dilute dye is greater than that of concentrated dye. The soil left after the trailing edge passed seemed to contain no residual dye in both the saturated and unsaturated cases. The success of demonstrating electromigration of large molecules in unsaturated soil is encouraging and indicates that it may be feasible to remediate in situ anionic heavy metals such as chromate from unsaturated soil with electrokinetic techniques. 23 refs., 7 figs

Electrokinetic remediation of contaminated soils

International Nuclear Information System (INIS)

Lindgren, E.R.; Kozak, M.W.; Mattson, E.D.

1991-01-01

Electrokinetic remediation of contaminated soil has been demonstrated for saturated and unsaturated sand in preliminary experiments using a novel transport visualization technique. Large anionic organic dyes were mixed with a portion of soil and the rate of electromigration of the dye in an imposed electric field was monitored photographically. One of the fastest current-normalized electromigration rates was measured in the driest sand, which contained 7% water by-weight. This moisture content is typical of the moisture content in the unsaturated zone of subsurface native soils found in New Mexico. The characteristics of the electromigration were similar in both the saturated and unsaturated sand. The leading edge of the dye migration front was diffuse while the trailing edge was sharp and concentrated. This and other observed behavior may indicate a concentration effect, where the electromigration rate of dilute dye is greater than that of concentrated dye. The soil left after the trailing edge passed seemed to contain no residual dye in both the saturated and unsaturated cases. The success of demonstrating electromigration of large molecules in unsaturated soil is encouraging and indicates that it may be feasible to remediate in situ anionic heavy metals such as chromate from unsaturated soil with electrokinetic techniques

Electrokinetic removal of Pb from tailings and the application of stabilization agents

OpenAIRE

Rajić, Ljiljana; Dalmacija, Božo; Dalmacija, Milena

2012-01-01

In this study, the possibility of applying the certain stabilization agents was investigated in order to improve the electrokinetic treatment of tailings with high concentrations of Pb. Different stabilization agents were inserted in the cathode region in order to improve the immobilisation of Pb ions that migrate towards the cathode, and thus control Pb movement and behaviour. EK treatments were carried out in the electrokinetic setup using the voltage gradient of 1 V/cm. The applied stabili...

Testing and evaluation of electrokinetic decontamination of concrete

International Nuclear Information System (INIS)

DePaoli, D.W.; Harris, M.T.; Ally, M.R.

1996-10-01

The goals and objectives of the technical task plan (TTP) are to (1) describe the nature and extent of concrete contamination within the Department of Energy (DOE) complex and emerging and commercial technologies applicable to these problems; (2) to match technologies to the concrete problems and recommend up to four demonstrations; (3) to initiate recommended demonstrations; and (4) to continue investigation and evaluation of the application of electrokinetic decontamination processes to concrete. This document presents findings of experimental and theoretical studies of the electrokinetic decontamination (EK) process and their implications for field demonstrations. This effort is an extension of the work performed under TTP 142005, ''Electroosmotic Concrete Decontamination. The goals of this task were to determine the applicability of EK for treating contaminated concrete and, if warranted, to evaluate EK as a potential technology for demonstration. 62 refs

Microbial fuel cell driving electrokinetic remediation of toxic metal contaminated soils.

Science.gov (United States)

Habibul, Nuzahat; Hu, Yi; Sheng, Guo-Ping

2016-11-15

An investigation of the feasibility of in-situ electrokinetic remediation for toxic metal contaminated soil driven by microbial fuel cell (MFC) is presented. Results revealed that the weak electricity generated from MFC could power the electrokinetic remediation effectively. The metal removal efficiency and its influence on soil physiological properties were also investigated. With the electricity generated through the oxidation of organics in soils by microorganisms, the metals in the soils would mitigate from the anode to the cathode. The concentrations of Cd and Pb in the soils increased gradually through the anode to the cathode regions after remediation. After about 143days and 108 days' operation, the removal efficiencies of 31.0% and 44.1% for Cd and Pb at the anode region could be achieved, respectively. Soil properties such as pH and soil conductivity were also significantly redistributed from the anode to the cathode regions. The study shows that the MFC driving electrokinetic remediation technology is cost-effective and environmental friendly, with a promising application in soil remediation. Copyright © 2016 Elsevier B.V. All rights reserved.

Electrokinetics and flocculation studies of coal

Energy Technology Data Exchange (ETDEWEB)

Dhawan, N. [Punjab Engineering College, Chandigarh (India). Dept. of Metallurgical Engineering

2008-07-01

Coal from India contains 25-35 per cent ash content. This leads to high slag volume, lower calorific value and inferior coke. In order to remove ash content, coal is washed, however, it retains some water that makes it difficult to process. Mechanical dewatering is performed in which a large portion of solids is removed while the remainder remains in centrifuge. There is therefore a need to recover solids and water. This paper discussed the use of flocculation and electrokinetic studies such as the determination of the point of zero charge. The experimental studies considered factors such as turbidity, faster settling, and compactness. Flocculation is brought about by the action of high molecular weight materials such as polyelectrolytes, where the material physically forms a bridge between two or more particles, uniting the sold particles into a random, three-dimensional structure, which is loose and porous. This paper also described the materials and methods of the electrokinetic studies on coal samples. Materials that were described included nephelometer, zeta meter, and a flocculator. It was concluded that in selecting the best flocculant, the preference order should be turbidity; settling rate; dosage; and moisture content. 3 refs., 2 tabs., 8 figs.

Researches in increase of efficiency of electrokinetic process of ground cleaning from radionuclides

International Nuclear Information System (INIS)

Prozorov, L.B.; Shcheglov, M.Y.; Nikolaevsky, V.B.; Tkachenko, A.V.

2003-01-01

Potentially perspective method of decontamination of ground is electrokinetic method, which basic advantage consists in an opportunity of its application for clearing ground with low filtering by ability directly on a place of local contaminated (in situ). Thus moving the large volumes of the contaminated ground is excluded. Base of this method is the processes of electromigration and electro-osmotic, proceeding in a contaminated ground lay at imposing an electrical field of a constant current. Electrokinetic method of cleaning of ground from radionuclides provides their transfer in water-soluble, mobile form, carry as positive or negative ions under influence of an electrical field into electrode chambers with their subsequent recycling.Electrokinetic method in practice can be realized as follows: in the contaminated ground establish special electrode devices, fill their electrolyte and connect to a source of a constant current. Formed in the anode device as a result of electrochemical decomposition of water the ions of hydrogen under action of an electrical field move to the cathode, thus cooperate with a ground and superside cations of radioactive elements. Desorbed cations of contaminate act in catholyte, which periodically or continuously is exposed to clearing, for example, on sorption column. Last years the experts MosNPO Radon carry out complex researches directed on development of electrokinetic technology of cleaning ground from radionuclides and heavy metals. To the present time laboratory and bench tests of electrokinetic method are carried out. The basic attention at study of process of cleaning was given to objects contaminated Cs-137, most difficult recovery an element, which is strongly fixed by clay minerals and can enter into crystal structure. (authors)

Optimum Remediation Conditions of Vertical Electrokinetic-Flushing Equipment to Decontaminate a Radioactive Soil

International Nuclear Information System (INIS)

Kim, Gye Nam; Yang, Byeong IL; Moon, Jei Kwon; Lee, Kune Woo

2009-01-01

Vertical electrokintic-flushing remediation equipment was developed for the remediation of a radioactive soil near nuclear facilities. An optimum reagent was selected to decontaminate the radioactive soil near nuclear facilities with the developed vertical electrokintic-flushing remediation equipment, and the optimum remediation conditions were established to obtain a higher remediation efficiency. Namely, acetic acid was selected as an optimum reagent due to its higher remediation efficiency. When the electrokinetic remediation and the electrokinetic-flushing remediation results were compared, the removal efficiency of 4.6% and the soil waste solution volume of 1.5 times were increased in the electrokinetic remediation. When the potential gradient within an electrokinetic soil cell was increased by two times (4.0 V/cm), the removal efficiencies of Co 2+ and Cs + were increased by about 4.3%( Co 2+ : 98.9%, Cs + : 96.7%). Also, when the reagent concentration was increased from 0.01 M to 0.05 M, the removal efficiency of Co 2+ was increased but that of Cs + was decreased. Therefore, the optimum remediation conditions were that the acetic concentration was 0.01 M ∼ 0.05 M, the potential gradient was 4 V/cm, the injection of reagent 2.4 ml/g, and the remediation period was 20 days.

Accuracy of a new patch pump based on a microelectromechanical system (MEMS) compared to other commercially available insulin pumps: results of the first in vitro and in vivo studies.

Science.gov (United States)

Borot, Sophie; Franc, Sylvia; Cristante, Justine; Penfornis, Alfred; Benhamou, Pierre-Yves; Guerci, Bruno; Hanaire, Hélène; Renard, Eric; Reznik, Yves; Simon, Chantal; Charpentier, Guillaume

2014-11-01

The JewelPUMP™ (JP) is a new patch pump based on a microelectromechanical system that operates without any plunger. The study aimed to evaluate the infusion accuracy of the JP in vitro and in vivo. For the in vitro studies, commercially available pumps meeting the ISO standard were compared to the JP: the MiniMed® Paradigm® 712 (MP), Accu-Chek® Combo (AC), OmniPod® (OP), Animas® Vibe™ (AN). Pump accuracy was measured over 24 hours using a continuous microweighing method, at 0.1 and 1 IU/h basal rates. The occlusion alarm threshold was measured after a catheter occlusion. The JP, filled with physiological serum, was then tested in 13 patients with type 1 diabetes simultaneously with their own pump for 2 days. The weight difference was used to calculate the infused insulin volume. The JP showed reduced absolute median error rate in vitro over a 15-minute observation window compared to other pumps (1 IU/h): ±1.02% (JP) vs ±1.60% (AN), ±1.66% (AC), ±2.22% (MP), and ±4.63% (OP), P pumps: 21 (19; 25) minutes vs 90 (85; 95), 58 (42; 74), and 143 (132; 218) minutes (AN, AC, MP), P pumps (-2.2 ± 5.6% vs -0.37 ± 4.0%, P = .25). The JP was found to be easier to wear than conventional pumps. The JP is more precise over a short time period, more sensitive to catheter occlusion, well accepted by patients, and consequently, of potential interest for a closed-loop insulin delivery system. © 2014 Diabetes Technology Society.

Impact of carbonate on the efficiency of heavy metal removal from kaolinite soil by the electrokinetic soil remediation method

Energy Technology Data Exchange (ETDEWEB)

Ouhadi, V.R., E-mail: vahidouhadi@yahoo.ca [Faculty of Engineering, Bu-Ali Sina University, Hamedan (Iran, Islamic Republic of); Yong, R.N. [RNY Geoenvironmental Research, North Saanich (Canada); Shariatmadari, N. [Iran University of Science and Technology, Tehran (Iran, Islamic Republic of); Saeidijam, S.; Goodarzi, A.R.; Safari-Zanjani, M. [Faculty of Engineering, Bu-Ali Sina University, Hamedan (Iran, Islamic Republic of)

2010-01-15

While the feasibility of using electrokinetics to decontaminate soils has been studied by several authors, the effects of soil composition on the efficiency of this method of decontamination has yet to be fully studied. This study focuses its attention on the effect of 'calcite or carbonate' (CaCO{sub 3}) on removal efficiency in electrokinetic soil remediation. Bench scale experiments were conducted on two soils: kaolinite and natural-soil of a landfill in Hamedan, Iran. Prescribed quantities of carbonates were mixed with these soils which were subsequently contaminated with zinc nitrate. After that, electrokinetic experiments were conducted to determine the efficiency of electrokinetic remediation. The results showed that an increase in the quantity of carbonate caused a noticeable increase on the contaminant retention of soil and on the resistance of soil to the contaminant removal by electrokinetic method. Because the presence of carbonates in the soil increases its buffering capacity, acidification is reduced, resulting in a decrease in the rate of heavy metal removed from the contaminant soil. This conclusion was validated by the evaluation of efficiency of electrokinetic method on a soil sample from the liner of a waste disposal site, with 28% carbonates.

Impact of carbonate on the efficiency of heavy metal removal from kaolinite soil by the electrokinetic soil remediation method

International Nuclear Information System (INIS)

Ouhadi, V.R.; Yong, R.N.; Shariatmadari, N.; Saeidijam, S.; Goodarzi, A.R.; Safari-Zanjani, M.

2010-01-01

While the feasibility of using electrokinetics to decontaminate soils has been studied by several authors, the effects of soil composition on the efficiency of this method of decontamination has yet to be fully studied. This study focuses its attention on the effect of 'calcite or carbonate' (CaCO 3 ) on removal efficiency in electrokinetic soil remediation. Bench scale experiments were conducted on two soils: kaolinite and natural-soil of a landfill in Hamedan, Iran. Prescribed quantities of carbonates were mixed with these soils which were subsequently contaminated with zinc nitrate. After that, electrokinetic experiments were conducted to determine the efficiency of electrokinetic remediation. The results showed that an increase in the quantity of carbonate caused a noticeable increase on the contaminant retention of soil and on the resistance of soil to the contaminant removal by electrokinetic method. Because the presence of carbonates in the soil increases its buffering capacity, acidification is reduced, resulting in a decrease in the rate of heavy metal removed from the contaminant soil. This conclusion was validated by the evaluation of efficiency of electrokinetic method on a soil sample from the liner of a waste disposal site, with 28% carbonates.

An improved electrokinetic method to consolidate porous materials

DEFF Research Database (Denmark)

Feijoo, Jorge; Ottosen, Lisbeth M.; Nóvoa, X. R.

2017-01-01

the consolidation using commercial products have some limitations, such as: (1) low penetrability; (2) no chemical and mineralogical affinity with the material to treat and (3) release of toxic compounds (VOCs), during the solvent evaporation. In the last years, a new consolidation method based on electrokinetic...... the pH of the solutions in contact with the porous material, which can damage it and (2) it is difficult to determine in which area the consolidation takes place. In this study an electrokinetic consolidation method, which has two steps between which the current is reversed, is proposed to solve all...... techniques was developed. This method allows filling some pores by the precipitation of an inorganic compound. As a result the method allows increasing the penetration depth of current consolidation treatments. However, this method needs to be improved since: (1) no special care is taking in controlling...

Determination of imidazole derivatives by micellar electrokinetic chromatography combined with solid-phase microextraction using activated carbon-polymer monolith as adsorbent.

Science.gov (United States)

Shih, Yung-Han; Lirio, Stephen; Li, Chih-Keng; Liu, Wan-Ling; Huang, Hsi-Ya

2016-01-08

In this study, an effective method for the separation of imidazole derivatives 2-methylimidazole (2-MEI), 4- methylimidazole (4-MEI) and 2-acetyl-4-tetrahydroxybutylimidazole (THI) in caramel colors using cation-selective exhaustive injection and sweeping micellar electrokinetic chromatography (CSEI-sweeping-MEKC) was developed. The limits of detection (LOD) and quantitation (LOQ) for the CSEI-sweeping-MEKC method were in the range of 4.3-80μgL(-1) and 14-270μgL(-1), respectively. Meanwhile, a rapid fabrication activated carbon-polymer (AC-polymer) monolithic column as adsorbent for solid-phase microextraction (SPME) of imidazole colors was developed. Under the optimized SPME condition, the extraction recoveries for intra-day, inter-day and column-to-column were in the range of 84.5-95.1% (<6.3% RSDs), 85.6-96.1% (<4.9% RSDs), and 81.3-96.1% (<7.1% RSDs), respectively. The LODs and LOQs of AC-polymer monolithic column combined with CSEI-sweeping-MEKC method were in the range of 33.4-60.4μgL(-1) and 111.7-201.2μgL(-1), respectively. The use of AC-polymer as SPME adsorbent demonstrated the reduction of matrix effect in food samples such as soft drink and alcoholic beverage thereby benefiting successful determination of trace-level caramel colors residues using CSEI-sweeping-MEKC method. The developed AC-polymer monolithic column can be reused for more than 30 times without any significant loss in the extraction recovery for imidazole derivatives. Copyright © 2015 Elsevier B.V. All rights reserved.

Ac and dc motor flooding times

International Nuclear Information System (INIS)

Crowley, D.A.; Hinton, J.H.

1988-01-01

Reactor safety studies, such as the emergency cooling system (ECS) limits analyses and the probabilistic risk assessment, require that the flood-out times be calculated for the ac and dc motors at the -40 foot level. New calculations are needed because dams of an improved design have been installed between the pump room and motor room, and because updated leak rate calculations have shown that the maximum possible leak rate is larger than that which had been previously calculated. The methodology for calculating the motor flood-out times has also been improved. A computer program has been written to calculate flood-out times for various leak rates and sump pump operabilities. For ECS limits analyses, the worst case dc motor flood-out times are 161 and 297 seconds in LKC and P-areas, respectively. These times are for a 135,468 gpm leak that first flows to the motor room and all of the sump pumps are off

Remediation of 137Cs contaminated concrete using electrokinetic phenomena and ionic salt washes in nuclear energy contexts.

Science.gov (United States)

Parker, Andrew J; Joyce, Malcolm J; Boxall, Colin

2017-10-15

This work describes the first known the use of electrokinetic treatments and ionic salt washes to remediate concrete contaminated with 137 Cs. A series of experiments were performed on concrete samples, contaminated with K + and 137 Cs, using a bespoke migration cell and an applied electric field (60V potential gradient and current limit of 35mA). Additionally, two samples were treated with an ionic salt wash (≤400molm -3 of KCl) alongside the electrokinetic treatment. The results show that the combined treatment produces removal efficiencies three times higher (>60%) than the electrokinetic treatment alone and that the decontamination efficiency appears to be proportional to the initial degree of contamination. Furthermore, the decontamination efficiencies are equivalent to previous electrokinetic studies that utilised hazardous chemical enhancement agents demonstrating the potential of the technique for use on nuclear licensed site. The results highlight the relationship between the initial contamination concentration within the concrete and achievable removal efficiency of electrokinetic treatment and other treatments. This information would be useful when selecting the most appropriate decontamination techniques for particular contamination scenarios. Copyright © 2017 Elsevier B.V. All rights reserved.

Electrokinetic decontamination of concrete

Energy Technology Data Exchange (ETDEWEB)

Lomasney, H. [ISOTRON Corp., New Orleans, LA (United States)

1995-10-01

The U.S. Department of Energy has assigned a priority to the advancement of technology for decontaminating concrete surfaces which have become contaminated with radionuclides, heavy metals, and toxic organics. This agency is responsible for decontamination and decommissioning of thousands of buildings. Electrokinetic extraction is one of the several innovative technologies which emerged in response to this initiative. This technique utilizes an electropotential gradient and the subsequent electrical transport mechanism to cause the controlled movement of ionics species, whereby the contaminants exit the recesses deep within the concrete. This report discusses the technology and use at the Oak Ridge k-25 plant.

Electrokinetic applications for environmental restoration, waste volume reduction, and contaminant containment systems

International Nuclear Information System (INIS)

Lomasney, H.L.; Lomasney, C.A.

1996-01-01

In the US and all over the world, following over 50 years of nuclear arms production operations, the magnitude of resultant environmental damage is only beginning to surface. The US Department of Energy estimates that by the year 2070, the total volume of high-level waste, transuranic waste, low-level waste, and low-level mixed waste, generated as a result of past and current nuclear activities, will exceed 20 million cubic meters. In Russia, it is reported that more than 30% of all groundwater is contaminated with agricultural and industrial chemical waste. Government agencies today are faced with the responsibility of developing technologies that are suitable for dealing with severe environmental contamination and accumulating waste inventories. In response to this demand, applications of electrokinetics have emerged in the field of environmental waste management as alternatives for environmental decontamination and ecological protection. Electrokinetics involves the movement of charged species under the influence of an applied electric field and is applicable in several areas of environmental waste management, including cleanup of soil and groundwater, barrier detection, and emergency or protective fencing. The worldwide interest in this technology has steadily escalated over the past decade. Today, state-of-the-art applications of electrokinetics have been demonstrated in the US, The Netherlands, Russia, The Ukraine, and India. This paper addresses the latest advances in the various applications of this technology as well as the most significant breakthroughs in the history of electrokinetics

Developing a Magnetocaloric Domestic Heat Pump

DEFF Research Database (Denmark)

Bahl, Christian R.H.

2014-01-01

beverage coolers, A/Cs for cars and electronics cooling. Devices for heating have not been extensively demonstrated. Here we consider a promising application of magnetocaloric heat pumps for domestic heating. The task of designing and building such a device is a multidisciplinary one encompassing materials...

Dynamic modelling of a PV pumping system with special consideration on water demand

International Nuclear Information System (INIS)

Campana, Pietro Elia; Li, Hailong; Yan, Jinyue

2013-01-01

Highlights: ► Evaluation of water demand and solar energy is essential for PV pumping system. ► The design for a PV water pumping system has been optimized based on dynamic simulations. ► It is important to conduct dynamic simulations to check the matching between water demand and water supply. ► AC pump driven by the fixed PV array is the most cost-effective solution. - Abstract: The exploitation of solar energy in remote areas through photovoltaic (PV) systems is an attractive solution for water pumping for irrigation systems. The design of a photovoltaic water pumping system (PVWPS) strictly depends on the estimation of the crop water requirements and land use since the water demand varies during the watering season and the solar irradiation changes time by time. It is of significance to conduct dynamic simulations in order to achieve the successful and optimal design. The aim of this paper is to develop a dynamic modelling tool for the design of a of photovoltaic water pumping system by combining the models of the water demand, the solar PV power and the pumping system, which can be used to validate the design procedure in terms of matching between water demand and water supply. Both alternate current (AC) and direct current (DC) pumps and both fixed and two-axis tracking PV array were analyzed. The tool has been applied in a case study. Results show that it has the ability to do rapid design and optimization of PV water pumping system by reducing the power peak and selecting the proper devices from both technical and economic viewpoints. Among the different alternatives considered in this study, the AC fixed system represented the best cost effective solution

Electrokinetic Fingering In Hele-Shaw Cells

Science.gov (United States)

Mirzadeh, Mohammad; Bazant, Martin

2016-11-01

Large scale flow problems in porous media, such as those encountered in underground oil reservoirs, are typically described by the Darcy's law. However, it is well known that many underground rock formations contain surface groups and minerals that dissociate in the presence of water. Convection of these charges by the pressure driven flow can then set up streaming current and streaming potential that affects the flow. Furthermore, electric fields that are often used to enhance oil recovery, e.g. by reducing the oil's viscosity through electro-thermal heating, drive electro-osmotic flows that could set up very large pressure in small pores. The full description of fluid flow thus requires a solution to the fully coupled electrokinetic problem. In their seminal work, Saffman and Taylor showed that the moving interface between two immiscible fluids in a porous medium becomes unstable if pushed by the low-viscosity fluid. Here we report on the role of electrokinetic phenomena on stability of these viscous fronts in Hele-Shaw cells by using analytic as well as numerical approaches. Interestingly, we find that the instability could be suppressed if the right physical conditions are met or otherwise enhanced, leading to greater mixing of two fluids.

Monitoring of electrokinetic in-situ-decontamination

Energy Technology Data Exchange (ETDEWEB)

Goldmann, T. [INTUS Inst. fuer Technologie und Umweltschutz e.V., Berlin (Germany)

2001-07-01

The need for a monitoring system for in-situ soil decontamination is two-fold: Firstly, to ensure that remediation is attained and secondly to minimize costs and treatment time. A further reason is the potential risk of unexpected mobilization or chemical generation of hazardous compounds which could result in an extension of the contamination into other regions of soil, the ground water or the atmosphere. Electrokinetic in-situ decontamination is based on transport processes in the ground that proceed with relatively low velocity. This results in treatment times of several months. Since the transport processes can be described by a mathematical model, monitoring should always be combined with qualified mathematical processing. This makes it possible to estimate treatment time and costs to be expected. The challenge of in-situ monitoring is to identify relevant parameters describing the state of the ground. These parameters must be independent from influences like weather but they must be sensitive to changes of soil characteristics. In the case of electrokinetic soil remediation, probes and sensors must be resistant to influences of electric fields. The function of sensors or measuring systems can be disturbed or even damaged or destroyed by electric fields (for example by electro-corrosion). (orig.)

Enhanced electrokinetic remediation of fluorine-contaminated soil by applying an ammonia continuous circulation system

Energy Technology Data Exchange (ETDEWEB)

Zhu, Shufa; Zhou, Ming; Zhang, Shuangyan [Henan University of Science and Technology, Luoyang (China)

2016-02-15

The objective of this research was to investigate the effects of ammonia continuous circulation enhanced electrokinetic remediation of fluorine contaminated soil and to analyze its influence on soil pH after remediation. An experimental study was carried out in self-made electrokinetic apparatus. The voltage gradient was set at 1.0V/cm and ammonia water with different concentrations was used as electrolyte which circulated in series. Comparative studies were made by using deionized water as electrolyte which circulated separately in one experiment and continuously in another. According to the experiment the continuous circulation of ammonia water increased the current value during the remediation process and maintained current through the soil cell stabler, which not only increased fluorine migration but also reduced energy consumption. Among the given ammonia concentrations (0, 0.01, 0.1 and 0.2mol/L) the removal rate increased with ammonia concentration. 0.2mol/L had the highest current (26.8mA), and the removal rate amounted up to 57.3%. By using ammonia circulation enhanced electrokinetic technology, the difference between pH values of cathode soil and anode soil became smaller. Ammonia continuous circulation enhanced electrokinetics can effectively remediate fluorine contaminated soil and the residual ammonia in the soil can also improve soil fertility.

Pilot Field Test of Electrokinetically-Delivered and Thermally Activated Persulfate (EKTAP) for Remediation of Chlorinated Solvents in Clay

Science.gov (United States)

O'Carrol, D. M.; Head, N.; Chowdhury, A. I.; Inglis, A.; Garcia, A. N.; Reynolds, D. A.; Hayman, J.; Hogberg, D.; Austrins, L. M.; Sidebottom, A.; Auger, M.; Eimers, J.; Gerhard, J.

2017-12-01

Remediation of low-permeability soils that are contaminated with chlorinated solvents is challenging. In-situ chemical oxidation (ISCO) with persulfate is promising, however, the delivery of the oxidant by hydraulic gradient is limited in low-permeability soils. Electrokinetic (EK) enhanced transport of amendments has shown the potential to overcome these limitations. In particular, the combined technology of EK-delivered and thermally activated persulfate (EKTAP) has been recently demonstrated in the laboratory as promising in these challenging environments (Chowdhury A. I. (2016) Hydraulic and Electrokinetic Delivery of Remediants for In-situ Remediation. Electronic Thesis and Dissertation Repository, Paper 4135). This study presents the first pilot field test to evaluate EKTAP to enhance the distribution and effectiveness of persulfate in clayey soil. The pilot field test was conducted at a contaminated site formerly occupied by a chlorinated solvent production facility. In the EK transport phase, 925 L of 40 g/L persulfate was injected over 57 days, during which 9A of direct current (DC) was applied between two electrodes spaced 3 m apart. In the subsequent heating phase, 10A of alternate current (AC) was applied across the same electrodes for an additional 70 days. Extensive sampling of soil and groundwater in this EKTAP cell were compared to those from two parallel control cells, one with EK only and one with no electrodes. Results indicated that EK can significantly increase transport rates of persulfate in clayey soil. Persulfate activation primarily occurred in the period of DC application, indicating that the natural reduction capacity of the clay soil had a significant impact on persulfate decomposition. Temperature mapping indicated that AC current was able to increase soil temperatures, validating the EKTAP concept. Degradation of chlorinated compounds, in particular, 1-2, dichloroethane (1,2- DCA), was observed to be substantial in areas of persulfate

Application of bioassays to evaluate a copper contaminated soil before and after a pilot-scale electrokinetic remediation

Energy Technology Data Exchange (ETDEWEB)

Wang Quanying [State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China); Graduate School of the Chinese Academy of Sciences, Beijing 100049 (China); Zhou Dongmei [State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China)], E-mail: dmzhou@issas.ac.cn; Cang Long [State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China); Graduate School of the Chinese Academy of Sciences, Beijing 100049 (China); Sun Tianran [State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China)

2009-02-15

Remediation programmes are considered to be complete when human risk-based criteria are met. However, these targets are often unsatisfied with the ecological parameters that may be important with regard to future soil use. Five soil subsamples, collecting along a pilot-scale soil column after electrokinetic treatment, were studied, from which about 42.0%-93.3% soil Cu had been successfully removed. A series of biological assays including soil microbial biomass carbon, basal soil respiration, soil urease activity, earthworm assays, and seed assays were used to evaluate their ecological risks. The results showed that the bioassay data from the treatment variants did not supposedly reflecting the decreased soil Cu concentrations after the electrokinetic treatment, but were highly correlated with some soil physicochemical characteristics. It suggests that bioassays are necessary to assess the ecotoxicity of soil after electrokinetic treatment. - There has been a motivation towards using biological indicators for risk assessment of contaminated soil after electrokinetic remediation.

Application of bioassays to evaluate a copper contaminated soil before and after a pilot-scale electrokinetic remediation

International Nuclear Information System (INIS)

Wang Quanying; Zhou Dongmei; Cang Long; Sun Tianran

2009-01-01

Remediation programmes are considered to be complete when human risk-based criteria are met. However, these targets are often unsatisfied with the ecological parameters that may be important with regard to future soil use. Five soil subsamples, collecting along a pilot-scale soil column after electrokinetic treatment, were studied, from which about 42.0%-93.3% soil Cu had been successfully removed. A series of biological assays including soil microbial biomass carbon, basal soil respiration, soil urease activity, earthworm assays, and seed assays were used to evaluate their ecological risks. The results showed that the bioassay data from the treatment variants did not supposedly reflecting the decreased soil Cu concentrations after the electrokinetic treatment, but were highly correlated with some soil physicochemical characteristics. It suggests that bioassays are necessary to assess the ecotoxicity of soil after electrokinetic treatment. - There has been a motivation towards using biological indicators for risk assessment of contaminated soil after electrokinetic remediation

Unbalanced Voltage Compensation in Low Voltage Residential AC Grids

DEFF Research Database (Denmark)

Trintis, Ionut; Douglass, Philip; Munk-Nielsen, Stig

2016-01-01

This paper describes the design and test of a control algorithm for active front-end rectifiers that draw power from a residential AC grid to feed heat pump loads. The control algorithm is able to control the phase to neutral or phase to phase RMS voltages at the point of common coupling...

The removal of Cs-137 from soil using washing-electrokinetic decontamination equipment

International Nuclear Information System (INIS)

Kim, Gyenam; Kim, Seungsoo; Kim, Geunho; Park, Hyemin; Kim, Wansuk; Park, Ukryang; Kwon, Hyeokju; Ryu, Ohha; Moon, Jeikwon

2012-01-01

The radioactive soil at the KAERI radioactive waste storage facility has slightly high hydro-conductivity, and was mainly contaminated with 137 Cs 30-35 years ago. Recently, a soil washing method has been applied to remove 137 Cs from radioactive soil, but it appears that the removal efficiency of 137 Cs had low and a lot of waste solution was generated. Meanwhile, an electrokinetic decontamination method provides high removal efficiency of 137 Cs and generates little waste effluent. Thus, it is suggested that an electrokinetic decontamination method is a suitable technology in consideration of the soil characteristics near South Korean nuclear facilities

Application of micellar electrokinetic capillary chromatography for routine analysis of different materials

Directory of Open Access Journals (Sweden)

Injac Rade

2008-01-01

Full Text Available Micellar electrokinetic capillary chromatography (MEKC has become a popular mode among the several capillary electro-migration techniques. Most drug analysis can be performed by using MEKC because of its wide applicability. Separation of very complex mixtures, determination of drugs in the biological materials, etc., can be successfully achieved by MEKC. This review surveys typical applications of MEKC analysis. Recent advances in MEKC, especially with solid-phase extraction and large-volume sample stacking, are described. Modes of electrokinetic chromatography including MEKC, a separation theory of MEKC, environmental friendly analysis, and selectivity manipulation in MEKC are also briefly mentioned.

Probing size-dependent electrokinetics of hematite aggregates

Energy Technology Data Exchange (ETDEWEB)

Kedra-Królik, Karolina; Rosso, Kevin M.; Zarzycki, Piotr

2017-02-01

Aqueous particle suspensions of many kinds are stabilized by the electrostatic potential developed at their surfaces from reaction with water and ions. An important and less well understood aspect of this stabilization is the dependence of the electrostatic surface potential on particle size. Surface electrostatics are typically probed by measuring particle electrophoretic mobilities and quantified in the electrokinetic potential (f), using commercially available Zeta Potential Analyzers (ZPA). Even though ZPAs provide frequency-spectra (histograms) of electrophoretic mobility and hydrodynamic diameter, typically only the maximal-intensity values are reported, despite the information in the remainder of the spectra. Here we propose a mapping procedure that inter-correlates these histograms to extract additional insight, in this case to probe particle size-dependent electrokinetics. Our method is illustrated for a suspension of prototypical iron (III) oxide (hematite, a-Fe2O3). We found that the electrophoretic mobility and f-potential are a linear function of the aggregate size. By analyzing the distribution of surface site types as a function of aggregate size we show that site coordination increases with increasing aggregate diameter. This observation explains why the acidity of the iron oxide particles decreases with increasing particle size.

Reduction of waste solution volume generated on electrokinetic remediation

Energy Technology Data Exchange (ETDEWEB)

Kim, Gye-Nam; Koo, Dae-Seo; Kim, Seung-Soo; Jeong, Jung-Whan; Han, Gyu-Seong; Moon, Jei-Kwon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2015-05-15

In this study, for the reduction of volume of metal oxides generated in cathode chamber, the optimum pH of waste electrolyte in cathode chamber were drawn out through several experiments with the manufactured electrokinetic decontamination equipment. Also, the required time to reach to below the clearance concentration level for self- disposal was estimated through experiments using the manufactured electrokinetic decontamination equipment. A diagram of soil decontamination process for the removal of uranium from contaminated soil was drawn out. The optimum pH of waste electrolyte in cathode chamber for the reduction of volume of metal oxides was below 2.35. Also, when the initial uranium concentration of the soils were 7-20 Bq/g, the required times to reach to below the clearance concentration level for self- disposal were 25-40 days. A diagram of soil decontamination process for the removal of uranium from contaminated soil was drawn out.

Electrokinetics for removal of low-level radioactivity from soil

Energy Technology Data Exchange (ETDEWEB)

Pamukcu, S. [Lehigh Univ., Bethlehem, PA (United States); Wittle, J.K. [Electro-Petroleum, Inc., Wayne, PA (United States)

1993-03-01

The electrokinetic process is an emerging technology for in situ soil decontamination in which chemical species, both ionic and nonionic, are transported to an electrode site in soil. These products are subsequently removed from the ground via collection systems engineered for each specific application. The work presented here describes part of the effort undertaken to investigate electrokinetically enhanced transport of soil contaminants in synthetic systems. These systems consisted of clay or clay-sand mixtures containing known concentrations of a selected heavy-metal salt solution. These metals included surrogate radionuclides such as Sr, Cs and U, and an anionic species of Cr. Degree of removal of these metals from soil by the electrokinetic treatment process was assessed through the metal concentration profiles generated across the soil between the electrodes. Removals of some metal species up to 99% were achieved at the anode or cathode end of the soil upon 24 to 48 hours of treatment or a maximum of 1 pore volume of water displacement toward the cathode compartment. Transient pH change through the soil had an effect on the metal movement, as evidenced by accumulation of the metals at the discharge ends of the soil specimens. This accumulation was attributed to the precipitation of the metal and increased cation retention capacity of the clay in high pH environment at the cathode end. In general, the reduced mobility and dissociation of the ionic species as they encounter areas of higher ionic concentration in their path of migration resulted in the accumulation of the metals at the discharge ends of the soil specimens.

Spectral induced polarization for monitoring electrokinetic remediation processes

Science.gov (United States)

Masi, Matteo; Losito, Gabriella

2015-12-01

Electrokinetic remediation is an emerging technology for extracting heavy metals from contaminated soils and sediments. This method uses a direct or alternating electric field to induce the transport of contaminants toward the electrodes. The electric field also produces pH variations, sorption/desorption and precipitation/dissolution of species in the porous medium during remediation. Since heavy metal mobility is pH-dependent, the accurate control of pH inside the material is required in order to enhance the removal efficiency. The common approach for monitoring the remediation process both in laboratory and in the field is the chemical analysis of samples collected from discrete locations. The purpose of this study is the evaluation of Spectral Induced Polarization as an alternative method for monitoring geochemical changes in the contaminated mass during remediation. The advantage of this technique applied to field-scale is to offer higher resolution mapping of the remediation site and lower cost compared to the conventional sampling procedure. We carried out laboratory-scale electrokinetic remediation experiments on fine-grained marine sediments contaminated by heavy metal and we made Spectral Induced Polarization measurements before and after each treatment. Measurements were done in the frequency range 10- 3-103 Hz. By the deconvolution of the spectra using the Debye Decomposition method we obtained the mean relaxation time and total chargeability. The main finding of this work is that a linear relationship exists between the local total chargeability and pH, with good agreement. The observed behaviour of chargeability is interpreted as a direct consequence of the alteration of the zeta potential of the sediment particles due to pH changes. Such relationship has a significant value for the interpretation of induced polarization data, allowing the use of this technique for monitoring electrokinetic remediation at field-scale.

Electrokinetic Amendment in Phytoremediation of Mixed Contaminated Soil

International Nuclear Information System (INIS)

Chirakkara, Reshma A.; Reddy, Krishna R.; Cameselle, Claudio

2015-01-01

This study examines the effects of electrokinetic amendments for phytoremediation of mixed contaminated soil where typical silty clay soil was spiked with organic contaminants (naphthalene and phenanthrene) and heavy metal (lead, cadmium and chromium). The contaminated soil was treated with compost and placed in electrokinetic cells, which were seeded with oat plant or sunflower. Thirty days after germination, 25 V alternating current was applied to selected cells using graphite electrodes for 3 h per day. The plants were harvested after a growth period of 61 days. One cell remained unplanted to evaluate the effect of the electric current on the soil, alone. The results confirm a significant reduction of heavy metals and organic contaminants in soil. However, there was no noticeable improvement of heavy metal phytoextraction or PAH degradation due to the application of electric field despite the increase in biomass production by the plants subjected to the electric current. The electric potential application time and frequency are suggested to be increased to have noticeable effects in heavy metal uptake and PAHs degradation.

The removal of Cs-137 from soil using washing-electrokinetic decontamination equipment

Energy Technology Data Exchange (ETDEWEB)

Kim, Gyenam; Kim, Seungsoo; Kim, Geunho; Park, Hyemin; Kim, Wansuk; Park, Ukryang; Kwon, Hyeokju; Ryu, Ohha; Moon, Jeikwon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2012-10-15

The radioactive soil at the KAERI radioactive waste storage facility has slightly high hydro-conductivity, and was mainly contaminated with {sup 137}Cs 30-35 years ago. Recently, a soil washing method has been applied to remove {sup 137}Cs from radioactive soil, but it appears that the removal efficiency of {sup 137}Cs had low and a lot of waste solution was generated. Meanwhile, an electrokinetic decontamination method provides high removal efficiency of {sup 137}Cs and generates little waste effluent. Thus, it is suggested that an electrokinetic decontamination method is a suitable technology in consideration of the soil characteristics near South Korean nuclear facilities.

The optimisation of electrokinetic remediation for heavy metals and radioactivity contamination on Holyrood-Lunas soil (acrisol species) in Sri Gading Industrial Area, Batu Pahat, Johor, Malaysia

International Nuclear Information System (INIS)

Mohamed Johar, S.; Embong, Z.

2015-01-01

The optimisation of electrokinetic remediation of an alluvial soil, locally named as Holyrood-Lunas from Sri Gading Industrial Area, Batu Pahat, Johor, Malaysia, had been conducted in this research. This particular soil was chosen due to its relatively high level of background radiation in a range between 139.2 and 539.4 nGy h -1 . As the background radiation is correlated to the amount of parent nuclides, 238 U and 232 Th, hence, a remediation technique, such as electrokinetic, is very useful in reducing these particular concentrations of heavy metal and radionuclides in soils. Several series of electrokinetics experiments were performed in laboratory scale in order to study the influence of certain electrokinetic parameters in soil. The concentration before (pre-electrokinetic) and after the experiment (post-electrokinetic) was determined via X-ray fluorescence (XRF) analysis technique. The best electrokinetic parameter that contributed to the highest achievable concentration removal of heavy metals and radionuclides on each experimental series was incorporated into a final electrokinetic experiment. Here, High Pure Germanium (HPGe) was used for radioactivity elemental analysis. The XRF results suggested that the most optimised electrokinetic parameters for Cr, Ni, Zn, As, Pb, Th and U were 3.0 h, 90 volts, 22.0 cm, plate-shaped electrode by 8 x 8 cm and in 1-D configuration order whereas the selected optimised electrokinetic parameters gave very low reduction of 238 U and 232 Th at 0.23 ± 2.64 and 2.74 ± 23.78 ppm, respectively. (authors)

Electrokinetic copper and iron migration in anaerobic granular sludge

NARCIS (Netherlands)

Virkutyte, J.; Sillanpää, M.J.; Lens, P.N.L.

2006-01-01

The application of low-level direct electric current (0.15 mA cm¿2) as an electrokinetic technique to treat copper-contaminated mesophilic anaerobic granular sludge was investigated. The sludge was obtained from a full scale UASB reactor treating paper-mill wastewater and was artificially

Some basic requirements for the application of electrokinetic methods for the reconstruction of masonry with rising humidity

Energy Technology Data Exchange (ETDEWEB)

Friese, P; Jacobasch, H J; Boerner, M

1987-12-01

Based on some theoretical statements concerning the electro-osmosis the most important requirements for the application of electrokinetic methods for drying masonry with rising humidity are described. Samples of brick masonry (brick and mortar) were examined by means of an electrokinetic measuring system (EKM) with different electrolytes (CaSO/sub 4/ and KCl) being used for different concentrations. It was found for all samples, that the zeta potential is provided with a negative sign and that the absolute value of the zeta potential approaches zero with increasing electrolyte concentration. Based on these measurements, an upper limit of the electrolyte concentration of 0.1 Mol/liter is established for the application of electrokinetic methods for drying masonry.

DEMONSTRATION BULLETIN: IN SITU ELECTROKINETIC EXTRACTION SYSTEM - SANDIA NATIONAL LABORATORIES

Science.gov (United States)

Sandia National Laboratories (SNL) has developed an in situ soil remediation system that uses electrokinetic principles to remediate hexavalent chromium-contaminated unsaturated or partially saturated soils. The technology involves the in situ application of direct current to the...

The optimisation of electrokinetic remediation for heavy metals and radioactivity contamination on Holyrood-Lunas soil (acrisol species) in Sri Gading Industrial Area, Batu Pahat, Johor, Malaysia.

Science.gov (United States)

Mohamed Johar, S; Embong, Z

2015-11-01

The optimisation of electrokinetic remediation of an alluvial soil, locally named as Holyrood-Lunas from Sri Gading Industrial Area, Batu Pahat, Johor, Malaysia, had been conducted in this research. This particular soil was chosen due to its relatively high level of background radiation in a range between 139.2 and 539.4 nGy h(-1). As the background radiation is correlated to the amount of parent nuclides, (238)U and (232)Th, hence, a remediation technique, such as electrokinetic, is very useful in reducing these particular concentrations of heavy metal and radionuclides in soils. Several series of electrokinetics experiments were performed in laboratory scale in order to study the influence of certain electrokinetic parameters in soil. The concentration before (pre-electrokinetic) and after the experiment (post-electrokinetic) was determined via X-ray fluorescence (XRF) analysis technique. The best electrokinetic parameter that contributed to the highest achievable concentration removal of heavy metals and radionuclides on each experimental series was incorporated into a final electrokinetic experiment. Here, High Pure Germanium (HPGe) was used for radioactivity elemental analysis. The XRF results suggested that the most optimised electrokinetic parameters for Cr, Ni, Zn, As, Pb, Th and U were 3.0 h, 90 volts, 22.0 cm, plate-shaped electrode by 8 × 8 cm and in 1-D configuration order whereas the selected optimised electrokinetic parameters gave very low reduction of (238)U and (232)Th at 0.23 ± 2.64 and 2.74 ± 23.78 ppm, respectively. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

The Status of Development of Electromagnetic Pumps for Space Application

International Nuclear Information System (INIS)

Kwak, J. S.; Kim, K. H.; Jeong, J. S.; Kim, Hee Reyoung

2013-01-01

Korea lunched this research as a part of the small nuclear power generation technology development for space. In this study, investigated are the basic principle and types of electromagnetic pump and the trend of electromagnetic pump technology development in foreign nations. The survey and analysis give the understanding of the suitability and prospect of electromagnetic pumps as space application technology in Korea. The analysis on the status of the development of electromagnetic pumps was carried out for the application to space environment. It was found that USA was approaching the research and development of electromagnetic pumps for space application. Most electromagnetic pumps surveyed have the efficiency between 35% and 50% where that of AC conduction pump is less than 6%. Further study was thought to have to be given for the mechanical and material characteristics, and the applicability of electromagnetic pumps for space nuclear reactor

Effect of alternating bioremediation and electrokinetics on the remediation of n-hexadecane-contaminated soil

Science.gov (United States)

Wang, Sa; Guo, Shuhai; Li, Fengmei; Yang, Xuelian; Teng, Fei; Wang, Jianing

2016-04-01

This study demonstrated the highly efficient degradation of n-hexadecane in soil, realized by alternating bioremediation and electrokinetic technologies. Using an alternating technology instead of simultaneous application prevented competition between the processes that would lower their efficiency. For the consumption of the soil dissolved organic matter (DOM) necessary for bioremediation by electrokinetics, bioremediation was performed first. Because of the utilization and loss of the DOM and water-soluble ions by the microbial and electrokinetic processes, respectively, both of them were supplemented to provide a basic carbon resource, maintain a high electrical conductivity and produce a uniform distribution of ions. The moisture and bacteria were also supplemented. The optimal DOM supplement (20.5 mg·kg-1 glucose; 80-90% of the total natural DOM content in the soil) was calculated to avoid competitive effects (between the DOM and n-hexadecane) and to prevent nutritional deficiency. The replenishment of the water-soluble ions maintained their content equal to their initial concentrations. The degradation rate of n-hexadecane was only 167.0 mg·kg-1·d-1 (1.9%, w/w) for the first 9 days in the treatments with bioremediation or electrokinetics alone, but this rate was realized throughout the whole process when the two technologies were alternated, with a degradation of 78.5% ± 2.0% for the n-hexadecane after 45 days of treatment.

The characterizations of rheological, electrokinetical and structural properties of ODTABr/MMT and HDTABr/MMT organoclays

International Nuclear Information System (INIS)

Isci, S.; Uslu, Y.O.; Ece, O.I.

2009-01-01

In the present paper, we have investigated as a function of surfactant concentration the rheological (yield value, plastic viscosity) and electrokinetic (mobility, zeta potential) properties of montmorillonite (MMT) dispersions. The influence of surfactants (Octadeccyltrimethylammonium bromide, ODTABr and Hexadecyltrimethylammonium bromide, HDTABr) on dispersions of Na-activated bentonite was evaluated by rheological and electrokinetic measurements, and X-ray diffraction (XRD) studies. The interactions between clay minerals and surfactants in water-based Na-activated MMT dispersions (2 wt.%) were examined in detail using rheologic parameters, such as viscosity, yield point, apparent and plastic viscosity, hysteresis area, and electrokinetic parameters of mobility and zeta potentials, and XRD also analyses helped to determine swelling properties of d-spacings. MMT and organoclay dispersions showed Bingham Plastic flow behavior. The zeta potential measurements displayed that the surfactant molecules hold on the clay particle surfaces and the XRD analyses displayed that they get into the basal layers

Pyrene removal from contaminated soil using electrokinetic process combined with surfactant

Directory of Open Access Journals (Sweden)

Seyed Enayat Hashemi

2015-07-01

Full Text Available Background: Pyrene is one of the stable polycyclic aromatic hydrocarbons that is considered as an important pollutants, because of extensive distribution in the environment and carcinogenic and mutagenic properties. Among the various treatment techniques, electrokinetic method is an environmental- friendly process for organic and mineral pollutants adsorbed to soil with fine pore size the same as clay and low hydraulic conductivity soils. For improving the efficiency of pyrene removal from soil, soulobilization of pyrene from soil could be used by surfactants. Materials and Methods : In this study, clay soil was selected as model because of the specific properties. Combined method using surfactant and electrokinetic was applied for pyrene removal from soil. Experiments were designed using response surface methodology (RSM, and effect of three variables includes surfactant concentration, voltage and surfactant type were evaluated for pyrene removal from contaminated soil. Results: Pyrene removal using anionic surfactants(SDS and nonionic surfactants(TX100 as a solubilizing agents has high removal efficiency. In the optimum condition with 95% confidence coefficient, utilizing mixed surfactants of sodium dodecyl sulfate and triton X-100 with the same volume, induced of 18.54 volt and 6.53 percent surfactant concentration have 94.6% pyrene removal efficiency. Conclusion:: Results of this study shows that electrokinetic process combined with surfactant as solubilizing agent could be applied as an efficient method for treating the pyrene-contaminated soils.

ELECTROKINETIC REMEDIATION STUDY FOR CADMIUM CONTAMINATED SOIL

OpenAIRE

P. Bala Ramudu; R. P. Tiwari; R. K. Srivastava

2007-01-01

This paper presents the results of an experimental research undertaken to evaluate different purging solutions to enhance the removal of cadmium from spiked contaminated field soil by electrokinetic remediation. Three experiments were conducted when soil was saturated with deionised water and subsequently deionised water, ammonium citrate and sodium citrate were used as purging solutions at anode end. One experiment was conducted when the soil was saturated with ammonium citrate and itself wa...

High-throughput particle manipulation by hydrodynamic, electrokinetic, and dielectrophoretic effects in an integrated microfluidic chip

KAUST Repository

Li, Shunbo; Li, Ming; Bougot-Robin, Kristelle; Cao, Wenbin; Yeung Yeung Chau, Irene; Li, Weihua; Wen, Weijia

2013-01-01

Integrating different steps on a chip for cell manipulations and sample preparation is of foremost importance to fully take advantage of microfluidic possibilities, and therefore make tests faster, cheaper and more accurate. We demonstrated particle manipulation in an integrated microfluidic device by applying hydrodynamic, electroosmotic (EO), electrophoretic (EP), and dielectrophoretic (DEP) forces. The process involves generation of fluid flow by pressure difference, particle trapping by DEP force, and particle redirect by EO and EP forces. Both DC and AC signals were applied, taking advantages of DC EP, EO and AC DEP for on-chip particle manipulation. Since different types of particles respond differently to these signals, variations of DC and AC signals are capable to handle complex and highly variable colloidal and biological samples. The proposed technique can operate in a high-throughput manner with thirteen independent channels in radial directions for enrichment and separation in microfluidic chip. We evaluated our approach by collecting Polystyrene particles, yeast cells, and E. coli bacteria, which respond differently to electric field gradient. Live and dead yeast cells were separated successfully, validating the capability of our device to separate highly similar cells. Our results showed that this technique could achieve fast pre-concentration of colloidal particles and cells and separation of cells depending on their vitality. Hydrodynamic, DC electrophoretic and DC electroosmotic forces were used together instead of syringe pump to achieve sufficient fluid flow and particle mobility for particle trapping and sorting. By eliminating bulky mechanical pumps, this new technique has wide applications for in situ detection and analysis.

High-throughput particle manipulation by hydrodynamic, electrokinetic, and dielectrophoretic effects in an integrated microfluidic chip

KAUST Repository

Li, Shunbo

2013-03-20

Integrating different steps on a chip for cell manipulations and sample preparation is of foremost importance to fully take advantage of microfluidic possibilities, and therefore make tests faster, cheaper and more accurate. We demonstrated particle manipulation in an integrated microfluidic device by applying hydrodynamic, electroosmotic (EO), electrophoretic (EP), and dielectrophoretic (DEP) forces. The process involves generation of fluid flow by pressure difference, particle trapping by DEP force, and particle redirect by EO and EP forces. Both DC and AC signals were applied, taking advantages of DC EP, EO and AC DEP for on-chip particle manipulation. Since different types of particles respond differently to these signals, variations of DC and AC signals are capable to handle complex and highly variable colloidal and biological samples. The proposed technique can operate in a high-throughput manner with thirteen independent channels in radial directions for enrichment and separation in microfluidic chip. We evaluated our approach by collecting Polystyrene particles, yeast cells, and E. coli bacteria, which respond differently to electric field gradient. Live and dead yeast cells were separated successfully, validating the capability of our device to separate highly similar cells. Our results showed that this technique could achieve fast pre-concentration of colloidal particles and cells and separation of cells depending on their vitality. Hydrodynamic, DC electrophoretic and DC electroosmotic forces were used together instead of syringe pump to achieve sufficient fluid flow and particle mobility for particle trapping and sorting. By eliminating bulky mechanical pumps, this new technique has wide applications for in situ detection and analysis.

Exploring driving forces and liquid properties for electrokinetic energy conversion

NARCIS (Netherlands)

Nguyen, Trieu

2015-01-01

This thesis presents an effort to understand electrokinetic energy conversion systems which are based on motion of ionic charges in micro- and nano-confinements. In particular, both experimentally and theoretically the utilization of different kind of liquids was investigated to convert mechanical

Accelerated Detection of Viral Particles by Combining AC Electric Field Effects and Micro-Raman Spectroscopy

Directory of Open Access Journals (Sweden)

Matthew Robert Tomkins

2015-01-01

Full Text Available A detection method that combines electric field-assisted virus capture on antibody-decorated surfaces with the “fingerprinting” capabilities of micro-Raman spectroscopy is demonstrated for the case of M13 virus in water. The proof-of-principle surface mapping of model bioparticles (protein coated polystyrene spheres captured by an AC electric field between planar microelectrodes is presented with a methodology for analyzing the resulting spectra by comparing relative peak intensities. The same principle is applied to dielectrophoretically captured M13 phage particles whose presence is indirectly confirmed with micro-Raman spectroscopy using NeutrAvidin-Cy3 as a labeling molecule. It is concluded that the combination of electrokinetically driven virus sampling and micro-Raman based signal transduction provides a promising approach for time-efficient and in situ detection of viruses.

Accelerated detection of viral particles by combining AC electric field effects and micro-Raman spectroscopy.

Science.gov (United States)

Tomkins, Matthew Robert; Liao, David Shiqi; Docoslis, Aristides

2015-01-08

A detection method that combines electric field-assisted virus capture on antibody-decorated surfaces with the "fingerprinting" capabilities of micro-Raman spectroscopy is demonstrated for the case of M13 virus in water. The proof-of-principle surface mapping of model bioparticles (protein coated polystyrene spheres) captured by an AC electric field between planar microelectrodes is presented with a methodology for analyzing the resulting spectra by comparing relative peak intensities. The same principle is applied to dielectrophoretically captured M13 phage particles whose presence is indirectly confirmed with micro-Raman spectroscopy using NeutrAvidin-Cy3 as a labeling molecule. It is concluded that the combination of electrokinetically driven virus sampling and micro-Raman based signal transduction provides a promising approach for time-efficient and in situ detection of viruses.

Electrokinetic transport of aerobic microorganisms under low-strength electric fields.

Science.gov (United States)

Maillacheruvu, Krishnanand Y; Chinchoud, Preethi R

2011-01-01

To investigate the feasibility of utilizing low strength electric fields to transport commonly available mixed cultures such as those from an activated sludge process, bench scale batch reactor studies were conducted in sand and sandy loam soils. A readily biodegradable substrate, dextrose, was used to test the activity of the transported microorganisms. Electric field strengths of 7V, 10.5V, and 14V were used. Results from this investigation showed that an electric field strength of 0.46 Volts per cm was sufficient to transport activated sludge microorganisms across a sandy loam soil across a distance of about 8 cm in 72 h. More importantly, the electrokinetically transported microbial culture remained active and viable after the transport process and was biodegrade 44% of the dextrose in the soil medium. Electrokinetic treatment without microorganisms resulted in removal of 37% and the absence of any treatment yielded a removal of about 15%.

Electrokinetic remediation of anionic contamination from unsaturated soil: Field application

International Nuclear Information System (INIS)

Lindgren, E.R.; Mattson, E.D.

1995-01-01

Electrokinetic remediation is an in situ technique under development at Sandia National Laboratories for removal of ionic contaminants from soil. While to date most other studies of this technique have focused on saturated soils, usually clays, the work at Sandia has been to extend the process to unsaturated sandy soils typical of arid regions. The impetus for this study is a chromate plume located beneath an old Sandia chemical waste landfill. Working in unsaturated soils is complicated by moisture control requirements, both to prevent undesired hydraulic transport of contamination outside the treatment zone and to optimize soil properties for efficient electrokinetic remediation. Two field tests will be discussed. First, a field test in clean soil is in progress to demonstrate moisture control with the Sandia electrode system. The second field demonstration, planned to begin the Fall of 1995, involves chromate removal from a in a chemical waste landfill

21 CFR 878.4780 - Powered suction pump.

Science.gov (United States)

2010-04-01

...) Identification. A powered suction pump is a portable, AC-powered or compressed air-powered device intended to be used to remove infectious materials from wounds or fluids from a patient's airway or respiratory support system. The device may be used during surgery in the operating room or at the patient's bedside...

Janus particle microshuttle: 1D directional self-propulsion modulated by AC electrical field

Directory of Open Access Journals (Sweden)

Jiliang Chen

2014-03-01

Full Text Available A catalytic Janus particle is capable of gaining energy from the surrounding fuel solution to drive itself to move continuously, which has an important impact in different fields, especially the field of micro-systems. However, the randomness of self-propulsion at the microscale restricts its use in practice. Achieving a directed self-propelled movement would greatly promote the application of the Janus particle. We proved experimentally that an AC electric field was an effective way to suppress Brownian motion and control the direction of self-propelled movement. The self-propulsion and dielectrophoretic response of a 2μm Janus particle were observed and the related basic data were collected. Interdigital electrodes, 20 μm in width, were energized in pulsed style to modulate the self-propulsion, which resulted in a shuttle-style motion in which a single Janus particle moved to and fro inside the strip electrode. The change of direction depends on its unique position: the catalyst side is always pointed outward and the orientation angle relative to the electrode is about 60°. Numerical simulation also proved that this position is reasonable. The present study could be beneficial with regard to self-propulsion and AC electrokinetics of the Janus particle.

Study on an alternating current electrothermal micropump for microneedle-based fluid delivery systems

Science.gov (United States)

Zhang, Rumi; Jullien, Graham A.; Dalton, Colin

2013-07-01

In this paper, we report on a modeling study of an AC electrothermal (ACET) micropump with high operating pressures as well as fast flow rates. One specific application area is for fluid delivery using microneedle arrays which require higher pressures and faster flow rates than have been previously reported with ACET devices. ACET is very suitable for accurate actuation and control of fluid flow, since the technique has been shown to be very effective in high conductivity fluids and has the ability to create a pulsation free flow. However, AC electrokinetic pumps usually can only generate low operating pressures of 1 to 100 Pa, where flow reversal is likely to occur with an external load. In order to realize a high performance ACET micropump for continuous fluid delivery, applying relatively high AC operating voltages (20 to 36 Vrms) to silicon substrate ACET actuators and using long serpentine channel allows the boosting of operating pressure as well as increasing the flow rates. Fast pumping flow rates (102-103 nl/s) and high operating pressures (1-12 kPa) can be achieved by applying both methods, making them of significant importance for continuous fluid delivery applications using microneedle arrays and other such biomedical devices.

Modeling of electrokinetic desalination of bricks

DEFF Research Database (Denmark)

Paz-Garcia, Juan Manuel; Johannesson, Björn; Ottosen, Lisbeth M.

2012-01-01

A model for the reactive transport of matter through porous media induced by an externally applied electric field is discussed. The Nernst–Planck–Poisson system of equations is used for modeling multi-species electro-diffusion transport phenomena, assuming chemical equilibrium during the process....... The system of equations includes the transport of water and the resulting advective flow of the aqueous species. The model takes into account transient change in porosity and its impact on transport. Test examples were performed and compared to experimental data for electrokinetic desalination treatment...

Basic principles of electrolyte chemistry for microfluidic electrokinetics. Part I: Acid-base equilibria and pH buffers.

Science.gov (United States)

Persat, Alexandre; Chambers, Robert D; Santiago, Juan G

2009-09-07

We review fundamental and applied acid-base equilibrium chemistry useful to microfluidic electrokinetics. We present elements of acid-base equilibrium reactions and derive rules for pH calculation for simple buffers. We also present a general formulation to calculate pH of more complex, arbitrary mixtures of electrolytes, and discuss the effects of ionic strength and temperature on pH calculation. More practically, we offer advice on buffer preparation and on buffer reporting. We also discuss "real world" buffers and likely contamination sources. In particular, we discuss the effects of atmospheric carbon dioxide on buffer systems, namely, the increase in ionic strength and acidification of typical electrokinetic device buffers. In Part II of this two-paper series, we discuss the coupling of acid-base equilibria with electrolyte dynamics and electrochemistry in typical microfluidic electrokinetic systems.

Automated electric valve for electrokinetic separation in a networked microfluidic chip.

Science.gov (United States)

Cui, Huanchun; Huang, Zheng; Dutta, Prashanta; Ivory, Cornelius F

2007-02-15

This paper describes an automated electric valve system designed to reduce dispersion and sample loss into a side channel when an electrokinetically mobilized concentration zone passes a T-junction in a networked microfluidic chip. One way to reduce dispersion is to control current streamlines since charged species are driven along them in the absence of electroosmotic flow. Computer simulations demonstrate that dispersion and sample loss can be reduced by applying a constant additional electric field in the side channel to straighten current streamlines in linear electrokinetic flow (zone electrophoresis). This additional electric field was provided by a pair of platinum microelectrodes integrated into the chip in the vicinity of the T-junction. Both simulations and experiments of this electric valve with constant valve voltages were shown to provide unsatisfactory valve performance during nonlinear electrophoresis (isotachophoresis). On the basis of these results, however, an automated electric valve system was developed with improved valve performance. Experiments conducted with this system showed decreased dispersion and increased reproducibility as protein zones isotachophoretically passed the T-junction. Simulations of the automated electric valve offer further support that the desired shape of current streamlines was maintained at the T-junction during isotachophoresis. Valve performance was evaluated at different valve currents based on statistical variance due to dispersion. With the automated control system, two integrated microelectrodes provide an effective way to manipulate current streamlines, thus acting as an electric valve for charged species in electrokinetic separations.

Modeling of Electrokinetic Processes Using the Nernst-Plank-Poisson System

DEFF Research Database (Denmark)

Paz-Garcia, Juan Manuel; Johannesson, Björn; Ottosen, Lisbeth M.

2010-01-01

Electrokinetic processes are known as the mobilization of species within the pore solution of porous materials under the effect of an external electric field. A finite elements model was implemented and used for the integration of the coupled Nernst-Plank-Poisson system of equations in order...

Application of electrokinetic soil flushing to four herbicides: A comparison.

Science.gov (United States)

dos Santos, E Vieira; Souza, F; Saez, C; Cañizares, P; Lanza, M R V; Martinez-Huitle, C A; Rodrigo, M A

2016-06-01

In this work, four bench-scale plants containing soil spiked with four herbicides (2,4-Dichlorophenoxyacetic acid (2,4-D), oxyfluorfen, chlorsulfuron and atrazine) undergo treatment consisting of an electrokinetic soil flushing (EKSF). Results clearly demonstrate that efficiency of EKSF depends on the chemical characteristic of the pesticide used. The amount of pesticide collected in the anode well is more significant than that collected in the cathode wells, indicating that the electromigration is much more important than drainage by electro-osmotic flux for this application. After 15 d of treatment, the 2,4-D is the pesticide most efficiently removed (95% of removal), while chlorsulfuron is the pesticide more resilient to the treatment. Additionally, volatilization was found to be a process of the major significance in the application of electrokinetic techniques to soil polluted with herbicides and because of that it should always be taken into account in the future design of full-scale processes. Copyright © 2016 Elsevier Ltd. All rights reserved.

Three-dimensional electrokinetic tweezing: device design, modeling, and control algorithms

International Nuclear Information System (INIS)

Probst, Roland; Shapiro, Benjamin

2011-01-01

We show how to extend electrokinetic tweezing (which can manipulate any visible particles and has more favorable force scaling than optical actuation enabling manipulation of nanoscale objects to nanoscopic precision) from two-dimensional control to the third dimension (3D). A novel and practical multi-layer device is presented that can create both planar and vertical flow and electric field modes. Feedback control algorithms are developed and demonstrated in realistic simulations to show 3D manipulation of one and two particles independently. The design and control results presented here are the essential next step to go from current 2D manipulation capabilities to an experimental demonstration of nano-precise 3D electrokinetic tweezing in a microfluidic system. Doing so requires integration with vision-based nano-precise 3D particle imaging, a capability that has been shown in the literature and which we are now combining with the 3D actuation and control methods demonstrated here. (technical note)

Self-assembled silver nanoparticles monolayers on mica-AFM, SEM, and electrokinetic characteristics

International Nuclear Information System (INIS)

Oćwieja, Magdalena; Morga, Maria; Adamczyk, Zbigniew

2013-01-01

A monodisperse silver particle suspension was produced by a chemical reduction method in an aqueous medium using sodium citrate. The average particle size determined by dynamic light scattering (DLS), transmission electron microscopy (TEM), and atomic force microscopy (AFM) was 28.5 nm. The DLS measurements confirmed that the suspension was stable for the ionic strength up to 3 × 10 −2 M NaCl. The electrophoretic mobility measurements revealed that the electrokinetic charge of particles was negative for pH range 3–10, assuming −50 e for pH = 9 and 0.01 M NaCl. Using the suspension, silver particle monolayers on mica modified by poly(allylamine hydrochloride) were produced under diffusion-controlled transport. Monolayer coverage, quantitatively determined by AFM and SEM, was regulated within broad limits by adjusting the nanoparticle deposition time. This allowed one to uniquely express the zeta potential of silver monolayers, determined by the in situ streaming potential measurements, in terms of particle coverage. Such dependencies obtained for various ionic strengths and pH, were successfully interpreted in terms of the 3D electrokinetic model. A universal calibrating graph was produced in this way, enabling one to determine silver monolayer coverage from the measured value of the streaming potential. Our experimental data prove that it is feasible to produce uniform and stable silver particle monolayers of well-controlled coverage and defined electrokinetic properties.

Experimental Validation of the Electrokinetic Theory and Development of Seismoelectric Interferometry by Cross-Correlation

Directory of Open Access Journals (Sweden)

F. C. Schoemaker

2012-01-01

Full Text Available We experimentally validate a relatively recent electrokinetic formulation of the streaming potential (SP coefficient as developed by Pride (1994. The start of our investigation focuses on the streaming potential coefficient, which gives rise to the coupling of mechanical and electromagnetic fields. It is found that the theoretical amplitude values of this dynamic SP coefficient are in good agreement with the normalized experimental results over a wide frequency range, assuming no frequency dependence of the bulk conductivity. By adopting the full set of electrokinetic equations, a full-waveform wave propagation model is formulated. We compare the model predictions, neglecting the interface response and modeling only the coseismic fields, with laboratory measurements of a seismic wave of frequency 500 kHz that generates electromagnetic signals. Agreement is observed between measurement and electrokinetic theory regarding the coseismic electric field. The governing equations are subsequently adopted to study the applicability of seismoelectric interferometry. It is shown that seismic sources at a single boundary location are sufficient to retrieve the 1D seismoelectric responses, both for the coseismic and interface components, in a layered model.

Capillary electrokinetic separation techniques for profiling of drugs and related products

NARCIS (Netherlands)

Hilhorst, M.J; Somsen, G.W; de Jong, G.J.

Capillary electrokinetic separation techniques offer high efficiency and peak capacity, and can be very useful for the analysis of samples containing a large variety of (unknown) compounds. Such samples are frequently met in impurity profiling of drugs (detection of potential impurities in a

A Hydromechanic-Electrokinetic Model for CO2 Sequestration in Geological Formations

NARCIS (Netherlands)

Al-Khoury, R.I.N.; Talebian, M.; Sluys, L.J.

2013-01-01

In this contribution, a finite element model for simulating coupled hydromechanic and electrokinetic flow in a multiphase domain is outlined. The model describes CO2 flow in a deformed, unsaturated geological formation and its associated streaming potential flow. The governing field equations are

Electrokinetic properties and conductance relaxation of polystyrene and silver iodide plugs

NARCIS (Netherlands)

Hoven, van den J.J.

1984-01-01

This thesis describes an experimental study on the electrokinetic and electrical properties of concentrated polystyrene and silver iodide dispersions. The purpose of the study is to obtain information on the structure of the electrical double layer at the solid-liquid interface. Special

Bulk conductivity of soft surface layers : experimental measurement and electrokinetic implications

NARCIS (Netherlands)

Yezek, L.P.

2005-01-01

Conductivity measurements were carried out on a family of polyacrylamide-co-sodium acrylate gels cross-linked with N,N¿ -methylenebisacrylamide in a homemade electrokinetic cell. The conductivity data allowed the equilibrium Donnan potential difference between the bulk gel and the bulk electrolyte

Faradaic double layer depolarization in electrokinetics: Onsager relations and substrate limitations

NARCIS (Netherlands)

Leeuwen, van H.P.; Duval, J.F.L.

2007-01-01

More often than not, the measurement of interfacial potentials by means of electrokinetic techniques is affected by interfering processes that may relax or even annihilate their primary response function. Among these processes are faradaic ones, provided that the substrate is sufficiently conducting

Electrokinetic Treatment for Model Caissons with Increasing Dimensions

Directory of Open Access Journals (Sweden)

Eltayeb Mohamedelhassan

2012-01-01

Full Text Available Electrokinetic treatment has been known in geotechnical engineering for over six decades, yet, the technique is rarely used. This stems from the absence of design guidelines and specifications for electrokinetic treatment systems. An important issue that need to be investigated and understood in order to devise guidelines from experimental results is the effect of the foundation element size on the outcome of the treatment. Also important is determining the optimum distance between the electrodes and estimating the energy consumption prior to treatment. This experimental study is a preliminary step in understanding some of the issues critical for the guidelines and specifications. Four model caissons with surface areas between 16000 and 128000 mm2 were embedded in soft clayey soil under water and treated for 168 hr with a dc voltage of 6 V. From the results, a distance between the anode (model caisson and the cathode equal 0.25 times the outside diameter of the model caisson was identified as optimum. Relationships between the surface area and axial capacity of the model caisson and the surface area and energy consumption were presented. The equations can be used to preliminary estimate the load capacity and the energy consumption for full-scale applications.

Separation Of N-Nitrosamines By Micellar Electrokinetic Chromatography

International Nuclear Information System (INIS)

Nur Amira Md Ali; Mohd Marsin Sanagi; Wan Aini Wan Ibrahim

2014-01-01

A simple and rapid micellar electrokinetic chromatography (MEKC) method was developed for separation of three selected N-Nitrosamines namely N-nitrosodipropylamine (NDPA), N-nitrosodibutylamine (NDBA) and N-nitrosodiphenylamine (NDPhA). The effects of composition of the buffer and its pH, concentration of surfactants on the separation and migration times of nitrosamines were investigated. The instrumental variables affecting sensitivity and resolution such as power supply and injection mode were carefully optimized. The best separation was achieved using 40 mM sodium dodecyl sulfate (SDS) as a surfactant in 10 mM phosphate buffer (pH 8.0) at a temperature of 25 degree Celsius, applied voltage of 29 kV, wavelength of 230 nm and electrokinetic injection of 9 s at 5 kV within 10 min analysis time. Excellent linearity was obtained in the concentration range of 2 to 100 μg/ mL with coefficients of determination, r 2 ≥0.979. This method showed good reproducibility with relative standard deviation (RSDs) value ranging from 2.46 % to 6.61 %. The limits of detection (LOD) and limits of quantification (LOQ) ranged from 0.16 to 0.43 μg/ mL and 0.54 to 1.44 μg/mL respectively. (author)

Electrokinetics of diffuse soft interfaces. I. Limit of low Donnan potentials

NARCIS (Netherlands)

Duval, J.F.L.; Leeuwen, van H.P.

2004-01-01

The current theoretical approaches to electrokinetics of gels or polyelectrolyte layers are based on the assumption that the position of the very interface between the aqueous medium and the gel phase is well defined. Within this assumption, spatial profiles for the volume fraction of polymer

SANDIA NATIONAL LABORATORIES IN SITU ELECTROKINETIC EXTRACTION TECHNOLOGY; INNOVATIVE TECHNOLOGY EVALUATION REPORT

Science.gov (United States)

As a part of the Superfund Innovative Technology Evaluation (SITE) Program, the U.S. Environmental Protection Agency evaluated the In-Situ Electrokinetic Extraction (ISEE) system at Sandia National Laboratories, Albuquerque, New Mexico.The SITE demonstration results show ...

Relationships between Electrokinetic Index of buccal epithelium and some functional and metabolic parameters at men with chronic pyelonephrite

Directory of Open Access Journals (Sweden)

Iryna G. Kyrylenko

2016-01-01

  Abstracts   Background. Known for a number of parameters of the body, which through regression equations derived can assess biological age. We examined relationships between electrokinetic mobility buccal epithelium cell nuclei, named Electrokinetic Index (EKI, and some functional and metabolic parameters of body. Methods. Under a observations were 23 men by age 24-70 years with chronic pyelonephrite in the phase of remission. We estimated the EKI, state of the vegetative and hormonal regulation as well as metabolism of cholesterol. Results. We confirned closely correlation (r=-0,89 between Metric Age and EKI. Baevskiy’s Adaptation Potential and Stange’s Test together determines EKI on 28%. RMSSD, VLF and Baevskiy’s Stress Index determines EKI on 31%. Plasma Colesterol and Klimov’s Atherogenicity Coefficient determines EKI on 56%. In summary model of multiple regression with stepwise excluding are currently two last parameters as well as Plasma Testosterone and relative Power Spectral VLF HRV, which together determines EKI on 73%: R=0,868; R2=0,754; Adjusted R2=0,730;F(4,4=31,4; χ2(4=58,9; p<10-5. Conclusion. Electrokinetic Index of buccal epithelium really rellects neuro-endocrine regulation and metabolism of Cholesterol.   Keywords: Electrokinetic Index, Biological Age, HRV, Cholesterol, Testosterone, Cortisol, Relationships.

Neural network based PWM AC chopper fed induction motor drive

Directory of Open Access Journals (Sweden)

Venkatesan Jamuna

2009-01-01

Full Text Available In this paper, a new Simulink model for a neural network controlled PWM AC chopper fed single phase induction motor is proposed. Closed loop speed control is achieved using a neural network controller. To maintain a constant fluid flow with a variation in pressure head, drives like fan and pump are operated with closed loop speed control. The need to improve the quality and reliability of the drive circuit has increased because of the growing demand for improving the performance of motor drives. With the increased availability of MOSFET's and IGBT's, PWM converters can be used efficiently in low and medium power applications. From the simulation studies, it is seen that the PWM AC chopper has a better harmonic spectrum and lesser copper loss than the Phase controlled AC chopper. It is observed that the drive system with the proposed model produces better dynamic performance, reduced overshoot and fast transient response. .

Self-assembled silver nanoparticles monolayers on mica-AFM, SEM, and electrokinetic characteristics.

Science.gov (United States)

Oćwieja, Magdalena; Morga, Maria; Adamczyk, Zbigniew

2013-03-01

A monodisperse silver particle suspension was produced by a chemical reduction method in an aqueous medium using sodium citrate. The average particle size determined by dynamic light scattering (DLS), transmission electron microscopy (TEM), and atomic force microscopy (AFM) was 28.5 nm. The DLS measurements confirmed that the suspension was stable for the ionic strength up to 3 × 10 -2  M NaCl. The electrophoretic mobility measurements revealed that the electrokinetic charge of particles was negative for pH range 3-10, assuming -50  e for pH = 9 and 0.01 M NaCl. Using the suspension, silver particle monolayers on mica modified by poly(allylamine hydrochloride) were produced under diffusion-controlled transport. Monolayer coverage, quantitatively determined by AFM and SEM, was regulated within broad limits by adjusting the nanoparticle deposition time. This allowed one to uniquely express the zeta potential of silver monolayers, determined by the in situ streaming potential measurements, in terms of particle coverage. Such dependencies obtained for various ionic strengths and pH, were successfully interpreted in terms of the 3D electrokinetic model. A universal calibrating graph was produced in this way, enabling one to determine silver monolayer coverage from the measured value of the streaming potential. Our experimental data prove that it is feasible to produce uniform and stable silver particle monolayers of well-controlled coverage and defined electrokinetic properties.

Physicochemical effects on uncontaminated kaolinite due to electrokinetic treatment using inert electrodes.

Science.gov (United States)

Liaki, Christina; Rogers, Christopher D F; Boardman, David I

2008-07-01

To determine the consequences of applying electrokinetics to clay soils, in terms of mechanisms acting and resulting effects on the clay, tests were conducted in which an electrical gradient was applied across controlled specimens of English China Clay (ECC) using 'inert' electrodes and a 'Reverse Osmosis' water feed to the electrodes (i.e., to mimic electrokinetic stabilisation without the stabiliser added or electrokinetic remediation without the contaminant being present). The specimens in which electromigration was induced over time periods of 3, 7, 14 and 28 days were subsequently tested for Atterberg Limits, undrained shear strength using a hand shear vane, water content, pH, conductivity and zeta potential. Water flowed through the system from anode to cathode and directly affected the undrained shear strength of the clay. Acid and alkali fronts were created around the anode and cathode, respectively, causing changes in the pH, conductivity and zeta potential of the soil. Variations in zeta potential were linked to flocculation and dispersion of the soil particles, thus raising or depressing the Liquid Limit and Plastic Limit, and influencing the undrained shear strength. Initial weakening around the anode and cathode was replaced by a regain of strength at the anode once acidic conditions had been created, while highly alkaline conditions at the cathode induced a marked improvement in strength. A novel means of indicating strength improvement by chemical means, i.e., free from water content effects, is presented to assist in interpretation of the results.

Electrokinetic treatment of an agricultural soil contaminated with heavy metals.

Science.gov (United States)

Figueroa, Arylein; Cameselle, Claudio; Gouveia, Susana; Hansen, Henrik K

2016-07-28

The high organic matter content in agricultural soils tends to complex and retain contaminants such as heavy metals. Electrokinetic remediation was tested in an agricultural soil contaminated with Co(+2), Zn(+2), Cd(+2), Cu(+2), Cr(VI), Pb(+2) and Hg(+2). The unenhanced electrokinetic treatment was not able to remove heavy metals from the soil due to the formation of precipitates in the alkaline environment in the soil section close to the cathode. Moreover, the interaction between metals and organic matter probably limited metal transportation under the effect of the electric field. Citric acid and ethylenediaminetetraacetic acid (EDTA) were used in the catholyte as complexing agents in order to enhance the extractability and removal of heavy metals from soil. These complexing agents formed negatively charged complexes that migrated towards the anode. The acid front electrogenerated at the anode favored the dissolution of heavy metals that were transported towards the cathode. The combined effect of the soil pH and the complexing agents resulted in the accumulation of heavy metals in the center of the soil specimen.

Determination of patulin in commercial apple juice by micellar electrokinetic chromatography.

Science.gov (United States)

Murillo, M; González-Peñas, E; Amézqueta, S

2008-01-01

A novel and validated micellar electrokinetic capillary chromatography (MEKC) method using ultraviolet detection (UV) has been applied to the quantitative analysis of patulin (PAT) in commercial apple juice. Patulin was extracted from samples with an ethylacetate solution. The micellar electrokinetic capillary chromatography (MECK) parameters studied for method optimization were buffer composition, voltage, temperature, and a separation between PAT and 5-hydroxymethylfurfural (HMF) (main interference in apple juice PAT analysis) peaks until reaching baseline. The method passes a series of validation tests including selectivity, linearity, limit of detection and quantification (0.7 and 2.5 microgL(-1), respectively), precision (within and between-day variability) and recovery (80.2% RSD=4%), accuracy, and robustness. This method was successfully applied to the measurement of 20 apple juice samples obtained from different supermarkets. One hundred percent of the samples were contaminated with a level greater than the limit of detection, with mean and median values of 41.3 and 35.7 microgL(-1), respectively.

Sizing and modelling of photovoltaic water pumping system

Science.gov (United States)

Al-Badi, A.; Yousef, H.; Al Mahmoudi, T.; Al-Shammaki, M.; Al-Abri, A.; Al-Hinai, A.

2018-05-01

With the decline in price of the photovoltaics (PVs) their use as a power source for water pumping is the most attractive solution instead of using diesel generators or electric motors driven by a grid system. In this paper, a method to design a PV pumping system is presented and discussed, which is then used to calculate the required size of the PV for an existing farm. Furthermore, the amount of carbon dioxide emissions saved by the use of PV water pumping system instead of using diesel-fuelled generators or electrical motor connected to the grid network is calculated. In addition, an experimental set-up is developed for the PV water pumping system using both DC and AC motors with batteries. The experimental tests are used to validate the developed MATLAB model. This research work demonstrates that using the PV water pumping system is not only improving the living conditions in rural areas but it is also protecting the environment and can be a cost-effective application in remote locations.

Electrokinetics in Earth Sciences: A Tutorial

Directory of Open Access Journals (Sweden)

L. Jouniaux

2012-01-01

in porous media, to be included in the special issue “Electrokinetics in Earth Sciences” of International Journal of Geophysics. We describe the methodology used for self-potential (SP and for seismoelectromagnetic measurements, for both field and laboratory experiments and for modelling. We give a large bibliography on the studies performed in hydrology to detect at distance the water flow, to deduce the thickness of the aquifer and to predict the hydraulic conductivity. The observation of SP has also been proposed to detect fractures in boreholes, to follow the hydraulic fracturing, and to predict the earthquakes. Moreover, we detail the studies on geothermal applications.

Reversible electrokinetic adsorption barriers for the removal of atrazine and oxyfluorfen from spiked soils.

Science.gov (United States)

Vieira Dos Santos, E; Sáez, C; Cañizares, P; Martínez-Huitle, C A; Rodrigo, M A

2017-01-15

This study demonstrates the application of reversible electrokinetic adsorption barrier (REKAB) technology to soils spiked with low-solubility pollutants. A permeable reactive barrier (PRB) of granular activated carbon (GAC) was placed between the anode and cathode of an electrokinetic (EK) soil remediation bench-scale setup with the aim of enhancing the removal of two low-solubility herbicides (atrazine and oxyfluorfen) using a surfactant solution (sodium dodecyl sulfate) as the flushing fluid. This innovative study focused on evaluating the interaction between the EK system and the GAC-PRB, attempting to obtain insights into the primary mechanisms involved. The obtained results highlighted the successful treatment of atrazine and oxyfluorfen in contaminated soils. The results obtained from the tests after 15days of treatment were compared with those obtained using the more conventional electrokinetic soil flushing (EKSF) technology, and very important differences were observed. Although both technologies are efficient for removing the herbicides from soils, REKAB outperforms EKSF. After the 15-day treatment tests, only approximately 10% of atrazine and oxyfluorfen remained in the soil, and adsorption onto the GAC bed was an important removal mechanism (15-17% of herbicide retained). The evaporation loses in REKAB were lower than those obtained in EKSF (45-50% compared to 60-65%). Copyright © 2016 Elsevier B.V. All rights reserved.

Electrokinetic desalination of protruded areas of stone avoiding the direct contact with electrodes

DEFF Research Database (Denmark)

Feijoo, J.; Matyscák, O.; Ottosen, Lisbeth M.

2017-01-01

of the sandstone highly contaminated with salts. Therefore, these results confirmed that it was possible to desalinate the sandstone using electrokinetic methods without the need to put in contact the affected areas with the equipment, reducing the possibility of altering it by manipulation.......Soluble salts are considered one of the main deterioration factors of porous building materials such as rocks, bricks or granites. The desalination treatments currently used in order to mitigate this alteration process are usually applied directly on the affected areas, which have often a low...... degree of cohesion precisely due to the deteriorating effect of the salts. The present study aimed to investigate the evaluation of a new approach based on electrokinetic techniques to desalinate rocks in monuments, specifically to desalinate carved reliefs. The procedure avoids the direct contact...

Spectral investigation of an a.c. plasma display

International Nuclear Information System (INIS)

Musa, G.; Nastase, L.; Trache, M.

1981-01-01

The work presents the spectral investigations on an a.c. plasma display, in order of a better understanding of the physical phenomena taking place in such a device. The spectral characteristics of the panel filled with a Penning mixture Ne + 0.1% Ar are presented and the influence of the nitrogen addition on these characteristics was evidentiated. The presence of the trace of nitrogen in the device may be used in order to evidentiate small leaks or imperfections in pumping and outgasing processing of the display. (author)

Electrokinetic remediation of a copper contaminated clay: 2-D experiments

Energy Technology Data Exchange (ETDEWEB)

Rodriguez Maroto, J.M.; Garcia Delgado, R.A.; Gomez Lahoz, C.; Garcia Herruzo, F. [Dept. de Ingenieria Quimica, Univ. de Malaga (Spain); Vereda Alonso, C. [Dept. de Ingenieria Quimica, Univ. de Malaga (Spain)]|[Inst. for Geologi and Geoteknik, Danmarks Tekniske Univ., Lyngby (Denmark)

2001-07-01

The in-situ electrokinetic soil remediation technique was used to clean-up a commercial standard kaolin that had been contaminated with copper. A number of experiments were carried out at a lab scale with the purpose of testing the performance of this technique in a 2 dimensional arrangement and establishing the base for future studies on the distribution of electrodes. (orig.)

Dual cloud point extraction coupled with hydrodynamic-electrokinetic two-step injection followed by micellar electrokinetic chromatography for simultaneous determination of trace phenolic estrogens in water samples.

Science.gov (United States)

Wen, Yingying; Li, Jinhua; Liu, Junshen; Lu, Wenhui; Ma, Jiping; Chen, Lingxin

2013-07-01

A dual cloud point extraction (dCPE) off-line enrichment procedure coupled with a hydrodynamic-electrokinetic two-step injection online enrichment technique was successfully developed for simultaneous preconcentration of trace phenolic estrogens (hexestrol, dienestrol, and diethylstilbestrol) in water samples followed by micellar electrokinetic chromatography (MEKC) analysis. Several parameters affecting the extraction and online injection conditions were optimized. Under optimal dCPE-two-step injection-MEKC conditions, detection limits of 7.9-8.9 ng/mL and good linearity in the range from 0.05 to 5 μg/mL with correlation coefficients R(2) ≥ 0.9990 were achieved. Satisfactory recoveries ranging from 83 to 108% were obtained with lake and tap water spiked at 0.1 and 0.5 μg/mL, respectively, with relative standard deviations (n = 6) of 1.3-3.1%. This method was demonstrated to be convenient, rapid, cost-effective, and environmentally benign, and could be used as an alternative to existing methods for analyzing trace residues of phenolic estrogens in water samples.

Electrokinetic Control of Viscous Fingering

Science.gov (United States)

Mirzadeh, Mohammad; Bazant, Martin Z.

2017-10-01

We present a theory of the interfacial stability of two immiscible electrolytes under the coupled action of pressure gradients and electric fields in a Hele-Shaw cell or porous medium. Mathematically, our theory describes a phenomenon of "vector Laplacian growth," in which the interface moves in response to the gradient of a vector-valued potential function through a generalized mobility tensor. Physically, we extend the classical Saffman-Taylor problem to electrolytes by incorporating electrokinetic (EK) phenomena. A surprising prediction is that viscous fingering can be controlled by varying the injection ratio of electric current to flow rate. Beyond a critical injection ratio, stability depends only upon the relative direction of flow and current, regardless of the viscosity ratio. Possible applications include porous materials processing, electrically enhanced oil recovery, and EK remediation of contaminated soils.

An improved resonantly driven piezoelectric gas pump

International Nuclear Information System (INIS)

Wu, Yue; Liu, Yong; Liu, Jianfang; Jiao, Xiaoyang; Yang, Zhigang; Wang, Long

2013-01-01

Piezoelectric pumps have the potential to be used in a variety of applications, such as in air circulation and compression. However, piezoelectric membrane pumps do not have enough driving capacity, and the heat induced during the direct contact between the driving part and the gas medium cannot be dissipated smoothly. When the gas is blocked, the piezoelectric vibrator generates heat quickly, which may eventually lead to damage. Resonantly driven piezoelectric stack pumps have high performance but no price advantage. In this situation, a novel, resonantly driven piezoelectric gas pump with annular bimorph as the driver is presented. In the study, the working principle of the novel pump was analyzed, the vibration mechanics model was determined, and the displacement amplified theory was studied. The outcome indicates that the displacement amplification factor is related with the original displacement provided by the piezoelectric bimorph. In addition, the displacement amplification effect is related to the stiffness of the spring lamination, adjustment spring, and piezoelectric vibrator, as well as to the systematic damping factor and the driving frequency. The experimental prototypes of the proposed pump were designed, and the displacement amplification effect and gas output performance were measured. At 70 V of sinusoidal AC driving voltage, the improved pump amplified the piezoelectric vibrator displacement by 4.2 times, the maximum gas output flow rate reached 1685 ml/min, and the temperature of the bimorph remained normal after 2000 hours of operation when the gas medium was blocked.

Geotechnical behaviour of low-permeability soils in surfactant-enhanced electrokinetic remediation.

Science.gov (United States)

López-Vizcaíno, Rubén; Navarro, Vicente; Alonso, Juan; Yustres, Ángel; Cañizares, Pablo; Rodrigo, Manuel A; Sáez, Cristina

2016-01-01

Electrokinetic processes provide the basis of a range of very interesting techniques for the remediation of polluted soils. These techniques consist of the application of a current field in the soil that develops different transport mechanisms capable of mobilizing several types of pollutants. However, the use of these techniques could generate nondesirable effects related to the geomechanical behavior of the soil, reducing the effectiveness of the processes. In the case of the remediation of polluted soils with plasticity index higher than 35, an excessive shrinkage can be observed in remediation test. For this reason, the continued evaporation that takes place in the sample top can lead to the development of cracks, distorting the electrokinetic transport regime, and consequently, the development of the operation. On the other hand, when analyzing silty soils, in the surroundings of injection surfactant wells, high seepages can be generated that give rise to the development of piping processes. In this article methods are described to allow a reduction, or to even eliminate, both problems.

Washing enhanced electrokinetic remediation for removal cadmium from real contaminated soil

International Nuclear Information System (INIS)

Giannis, Apostolos; Gidarakos, Evangelos

2005-01-01

The main objective of this study is to evaluate the combination of electrokinetic remediation and soil washing technology in order to remove cadmium from contaminated soil. This paper presents the results of an experimental research undertaken to evaluate different washing and purging solutions to enhance the removal of cadmium from a real contaminated soil during electrokinetic remediation. Two different experimental modules were applied in the laboratory. Soil was saturated with tap water, while acetic and hydrochloric acids, as well as ethylenediaminetetraacetic acid (EDTA) were used as purging solutions in the first module. Results show that there was a decrease of cadmium concentration near anode, but a significant increase in the middle of the cell, due to the increasing pH. Citric, nitric and acetic acids were used for soil washing and purging solutions in the second module. In this case, an 85% reduction of cadmium concentration was achieved. Therefore, results indicate that soil pH and washing solutions are the most important factors in governing the dissolution and/or desorption of Cd in a soil system under electrical fields

Basic principles of electrolyte chemistry for microfluidic electrokinetics. Part II: Coupling between ion mobility, electrolysis, and acid-base equilibria.

Science.gov (United States)

Persat, Alexandre; Suss, Matthew E; Santiago, Juan G

2009-09-07

We present elements of electrolyte dynamics and electrochemistry relevant to microfluidic electrokinetics experiments. In Part I of this two-paper series, we presented a review and introduction to the fundamentals of acid-base chemistry. Here, we first summarize the coupling between acid-base equilibrium chemistry and electrophoretic mobilities of electrolytes, at both infinite and finite dilution. We then discuss the effects of electrode reactions on microfluidic electrokinetic experiments and derive a model for pH changes in microchip reservoirs during typical direct-current electrokinetic experiments. We present a model for the potential drop in typical microchip electrophoresis device. The latter includes finite element simulation to estimate the relative effects of channel and reservoir dimensions. Finally, we summarize effects of electrode and electrolyte characteristics on potential drop in microfluidic devices. As a whole, the discussions highlight the importance of the coupling between electromigration and electrophoresis, acid-base equilibria, and electrochemical reactions.

Application of sequential extraction analysis to electrokinetic remediation of cadmium, nickel and zinc from contaminated soils

International Nuclear Information System (INIS)

Giannis, Apostolos; Pentari, Despina; Wang, Jing-Yuan; Gidarakos, Evangelos

2010-01-01

An enhanced electrokinetic process for the removal of cadmium (Cd), nickel (Ni) and zinc (Zn) from contaminated soils was performed. The efficiency of the chelate agents nitrilotriacetic acid (NTA), diethylenetriaminepentaacetic acid (DTPA) and diaminocycloexanetetraacetic acid (DCyTA) was examined under constant potential gradient (1.23 V/cm). The results showed that chelates were effective in desorbing metals at a high pH, with metal-chelate anion complexes migrating towards the anode. At low pH, metals existing as dissolved cations migrated towards the cathode. In such conflicting directions, the metals accumulated in the middle of the cell. Speciation of the metals during the electrokinetic experiments was performed to provide an understanding of the distribution of the Cd, Ni and Zn. The results of sequential extraction analysis revealed that the forms of the metals could be altered from one fraction to another due to the variation of physico-chemical conditions throughout the cell, such as pH, redox potential and the chemistry of the electrolyte solution during the electrokinetic treatment. It was found that binding forms of metals were changed from the difficult type to easier extraction type.

Application of sequential extraction analysis to electrokinetic remediation of cadmium, nickel and zinc from contaminated soils

Energy Technology Data Exchange (ETDEWEB)

Giannis, Apostolos, E-mail: apostolos.giannis@enveng.tuc.gr [Department of Environmental Engineering, Technical University of Crete, Politechnioupolis, Chania 73100 (Greece); Pentari, Despina [Department of Mineral Resources Engineering, Technical University of Crete, Politechnioupolis, Chania 73100 (Greece); Wang, Jing-Yuan [Residues and Resource Reclamation Centre (R3C), Nanyang Technological University, 50 Nanyang Avenue, 639798 Singapore (Singapore); Gidarakos, Evangelos, E-mail: gidarako@mred.tuc.gr [Department of Environmental Engineering, Technical University of Crete, Politechnioupolis, Chania 73100 (Greece)

2010-12-15

An enhanced electrokinetic process for the removal of cadmium (Cd), nickel (Ni) and zinc (Zn) from contaminated soils was performed. The efficiency of the chelate agents nitrilotriacetic acid (NTA), diethylenetriaminepentaacetic acid (DTPA) and diaminocycloexanetetraacetic acid (DCyTA) was examined under constant potential gradient (1.23 V/cm). The results showed that chelates were effective in desorbing metals at a high pH, with metal-chelate anion complexes migrating towards the anode. At low pH, metals existing as dissolved cations migrated towards the cathode. In such conflicting directions, the metals accumulated in the middle of the cell. Speciation of the metals during the electrokinetic experiments was performed to provide an understanding of the distribution of the Cd, Ni and Zn. The results of sequential extraction analysis revealed that the forms of the metals could be altered from one fraction to another due to the variation of physico-chemical conditions throughout the cell, such as pH, redox potential and the chemistry of the electrolyte solution during the electrokinetic treatment. It was found that binding forms of metals were changed from the difficult type to easier extraction type.

Coupled electrokinetics-adsorption technique for simultaneous removal of heavy metals and organics from saline-sodic soil.

Science.gov (United States)

Lukman, Salihu; Essa, Mohammed Hussain; Mu'azu, Nuhu Dalhat; Bukhari, Alaadin

2013-01-01

In situ remediation technologies for contaminated soils are faced with significant technical challenges when the contaminated soil has low permeability. Popular traditional technologies are rendered ineffective due to the difficulty encountered in accessing the contaminants as well as when employed in settings where the soil contains mixed contaminants such as petroleum hydrocarbons, heavy metals, and polar organics. In this study, an integrated in situ remediation technique that couples electrokinetics with adsorption, using locally produced granular activated carbon from date palm pits in the treatment zones that are installed directly to bracket the contaminated soils at bench-scale, is investigated. Natural saline-sodic soil, spiked with contaminant mixture (kerosene, phenol, Cr, Cd, Cu, Zn, Pb, and Hg), was used in this study to investigate the efficiency of contaminant removal. For the 21-day period of continuous electrokinetics-adsorption experimental run, efficiency for the removal of Zn, Pb, Cu, Cd, Cr, Hg, phenol, and kerosene was found to reach 26.8, 55.8, 41.0, 34.4, 75.9, 92.49, 100.0, and 49.8%, respectively. The results obtained suggest that integrating adsorption into electrokinetic technology is a promising solution for removal of contaminant mixture from saline-sodic soils.

Electrokinetic microchannel battery by means of electrokinetic and microfluidic phenomena

Science.gov (United States)

Yang, Jun; Lu, Fuzhi; Kostiuk, Larry W.; Kwok, Daniel Y.

2003-11-01

Pressure-driven flow in a microchannel induces a streaming current due to the presence of an electrical double layer in the interface between the electrolyte solution and channel wall. As the streaming current is of the order of a nano-amphere and is additive, we propose here a method to develop an electrokinetic battery consisting of an array of microchannels that converts the hydrostatic pressure of a liquid into electrical work. We have given oscillating analytical solutions by means of an electrical circuit analysis to model the multi-microchannel battery. Using superposition of the appropriate Fourier series, the derived analytical solutions are useful to predict the current when there is more general time-dependent flow through a microchannel array. To illustrate the idea, we have studied steady-state pressure-driven flow in micropore porous glass filter and compared the results with those predicted from our model. From a 30 cm hydrostatic pressure drop, an external current of 1-2 µA was obtained by means of water passing through the micropore porous glass filter. A larger current can be obtained by simply using a solution with higher salt concentration. This results in a new and potentially useful method of energy conversion by means of an array of microchannels.

Geothermal energy. Ground source heat pumps

International Nuclear Information System (INIS)

2009-01-01

Geothermal energy can be harnessed in 2 different ways: electricity or heat generation. The combined net electrical geothermal power of the European Union countries reached 719.3 MWe in 2008 (4.8 MW up on 2007) for 868.1 MWe of installed capacity. Gross electrical production contracted slightly in 2008 (down 1% on the 2007 level) and stood at 5809.5 GWh in 2008. Italy has a overwhelming position with a production of 5520.3 GWh. Geothermal heat production concerning aquifers whose temperature is 30-150 C. degrees generally at a depth of 1-3 km is called low- and medium-enthalpy energy. 18 of the 27 EU members use low- and medium-enthalpy energy totaling 2560.0 MWth of installed capacity that yielded 689.2 ktoe in 2008 and 3 countries Hungary, Italy and France totaling 480.3 ktoe. Very low-enthalpy energy concerns the exploitation of shallow geothermal resources using geothermal heat pumps. In 2008, 114452 ground heat pumps were sold in Europe. At the end of 2008, the installed capacity was 8955.4 MWth (16.5% up on 2007 level, it represented 785206 pumps. Over one million ground heat pumps are expected to be operating in 2010 in Europe. (A.C.)

Heat Pumps With Direct Expansion Solar Collectors

Science.gov (United States)

Ito, Sadasuke

In this paper, the studies of heat pump systems using solar collectors as the evaporators, which have been done so far by reserchers, are reviwed. Usually, a solar collector without any cover is preferable to one with ac over because of the necessity of absorbing heat from the ambient air when the intensity of the solar energy on the collector is not enough. The performance of the collector depends on its area and the intensity of the convective heat transfer on the surface. Fins are fixed on the backside of the collector-surface or on the tube in which the refrigerant flows in order to increase the convective heat transfer. For the purpose of using a heat pump efficiently throughout year, a compressor with variable capacity is applied. The solar assisted heat pump can be used for air conditioning at night during the summer. Only a few groups of people have studied cooling by using solar assisted heat pump systems. In Japan, a kind of system for hot water supply has been produced commercially in a company and a kind of system for air conditioning has been installed in buildings commercially by another company.

A laboratory feasibility study on a new electrokinetic nutrient injection pattern and bioremediation of phenanthrene in a clayey soil

International Nuclear Information System (INIS)

Xu Wei; Wang Cuiping; Liu Haibin; Zhang Zhiyuan; Sun Hongwen

2010-01-01

Electrokinetic (EK) injection has recently been proposed to supply nutrients and electron acceptors in bioremediation of low permeable soils. However, effective pH control and uniform injection of inorganic ions have yet to be developed. The present study investigated a new EK injection pattern, which combined electrolyte circulation and electrode polarity reversal on a clayey soil. Soil pH could be controlled ranging from 7.0 to 7.6 by circulating the mixed electrolyte at a suitable rate (800 mL/h in this study) without any buffer. Ammonium and nitrate ions were distributed more uniformly in soil by electrode polarity reversal. The developed electrokinetic injection technology was applied primarily in bioremediation of phenanthrene contaminated soil. Over 80% of the initial 200 mg/kg phenanthrene in soil could be removed in 20 d, and greater phenanthrene removal was achieved using electrode polarity reversal. Hence, the present study provides a promising electrokinetic injection technology for bioremediation of contaminated soils.

Effects of triethyl phosphate and nitrate on electrokinetically enhanced biodegradation of diesel in low permeability soils.

Science.gov (United States)

Lee, G T; Ro, H M; Lee, S M

2007-08-01

Bench-scale experiments for electrokinetically enhanced bioremediation of diesel in low permeability soils were conducted. An electrokinetic reactor (ER) was filled with kaolin that was artificially contaminated with diesel at a level of 2500 mg kg(-1). A constant voltage gradient of 1.0 V cm(-1) was applied. In phosphorus transport experiments, KH2PO4 was not distributed homogeneously along the ER, and most of the transported phosphorus was converted to water-insoluble aluminum phosphate after 12 days of electrokinetic (EK) operation. However, the advancing P front of triethyl phosphate (TEP) progressed with time and resulted in uniform P distribution. The treatments employed in the electrokinetically enhanced bioremediation of diesel were control (no addition of nitrogen and phosphorus), NP (KNO3+ KH2PO4), NT (KNO3+ TEP), UP (urea+ KH2PO4), and UT (urea+TEP). Analysis of effluent collected during the first 12 days of EK operation showed that diesel was not removed from the kaolin. After nutrient delivery, using the EK operation, the ER was transferred into an incubator for the biodegradation process. After 60 days of biodegradation, the concentrations of diesel in the kaolin for the NP, NT, UP, UT, and control treatments were 1356, 1002, 1658, 1612, and 2003 mg kg(-1), respectively. The ratio of biodegraded diesel concentration to initial concentration (2465 mg kg(-1)) in NP, NT, UP, UT, and control were 45.0%, 59.4%, 32.7%, 34.6%, and 18.7%, respectively. This result showed that TEP, treated along with NO3-, was most effective for the biodegradation of diesel. TEP was delivered more efficiently to the target zones and with less phosphorus loss than KH2PO4. However, this facilitated phosphorus delivery was effective in biodegrading diesel under anaerobic conditions only when electron acceptors, such as NO3-, were present.

Particle morphology and mineral structure of heavy metal-contaminated kaolin soil before and after electrokinetic remediation.

Science.gov (United States)

Roach, Nicole; Reddy, Krishna R; Al-Hamdan, Ashraf Z

2009-06-15

This study aims to characterize the physical distribution of heavy metals in kaolin soil and the chemical and structural changes in kaolinite minerals that result from electrokinetic remediation. Three bench-scale electrokinetic experiments were conducted on kaolin that was spiked with Cr(VI) alone, Ni (II) alone, and a combination of Cr(VI), Ni(II) and Cd(II) under a constant electric potential of 1VDC/cm for a total duration of 4 days. Transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD) analyses were performed on the soil samples before and after electrokinetic remediation. Results showed that the heavy metal contaminant distribution in the soil samples was not observable using TEM and EDX. EDX detected nickel and chromium on some kaolinite particles and titanium-rich, high-contrast particles, but no separate phases containing the metal contaminants were detected. Small amounts of heavy metal contaminants that were detected by EDX in the absence of a visible phase suggest that ions are adsorbed to kaolinite particle surfaces as a thin coating. There was also no clear correlation between semiquantitative analysis of EDX spectra and measured total metal concentrations, which may be attributed to low heavy metal concentrations and small size of samples used. X-ray diffraction analyses were aimed to detect any structural changes in kaolinite minerals resulting from EK. The diffraction patterns showed a decrease in peak height with decreasing soil pH value, which indicates possible dissolution of kaolinite minerals during electrokinetic remediation. Overall this study showed that the changes in particle morphology were found to be insignificant, but a relationship was found between the crystallinity of kaolin and the pH changes induced by the applied electric potential.

Particle morphology and mineral structure of heavy metal-contaminated kaolin soil before and after electrokinetic remediation

International Nuclear Information System (INIS)

Roach, Nicole; Reddy, Krishna R.; Al-Hamdan, Ashraf Z.

2009-01-01

This study aims to characterize the physical distribution of heavy metals in kaolin soil and the chemical and structural changes in kaolinite minerals that result from electrokinetic remediation. Three bench-scale electrokinetic experiments were conducted on kaolin that was spiked with Cr(VI) alone, Ni (II) alone, and a combination of Cr(VI), Ni(II) and Cd(II) under a constant electric potential of 1 VDC/cm for a total duration of 4 days. Transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD) analyses were performed on the soil samples before and after electrokinetic remediation. Results showed that the heavy metal contaminant distribution in the soil samples was not observable using TEM and EDX. EDX detected nickel and chromium on some kaolinite particles and titanium-rich, high-contrast particles, but no separate phases containing the metal contaminants were detected. Small amounts of heavy metal contaminants that were detected by EDX in the absence of a visible phase suggest that ions are adsorbed to kaolinite particle surfaces as a thin coating. There was also no clear correlation between semiquantitative analysis of EDX spectra and measured total metal concentrations, which may be attributed to low heavy metal concentrations and small size of samples used. X-ray diffraction analyses were aimed to detect any structural changes in kaolinite minerals resulting from EK. The diffraction patterns showed a decrease in peak height with decreasing soil pH value, which indicates possible dissolution of kaolinite minerals during electrokinetic remediation. Overall this study showed that the changes in particle morphology were found to be insignificant, but a relationship was found between the crystallinity of kaolin and the pH changes induced by the applied electric potential.

Ligand-enhanced electrokinetic remediation of metal-contaminated marine sediments with high acid buffering capacity.

Science.gov (United States)

Masi, Matteo; Iannelli, Renato; Losito, Gabriella

2016-06-01

The suitability of electrokinetic remediation for removing heavy metals from dredged marine sediments with high acid buffering capacity was investigated. Laboratory-scale electrokinetic remediation experiments were carried out by applying two different voltage gradients to the sediment (0.5 and 0.8 V/cm) while circulating water or two different chelating agents at the electrode compartments. Tap water, 0.1 M citric acid and 0.1 M ethylenediaminetetraacetic acid (EDTA) solutions were used respectively. The investigated metals were Zn, Pb, V, Ni and Cu. In the unenhanced experiment, the acid front could not propagate due to the high acid buffering capacity of the sediments; the production of OH(-) ions at the cathode resulted in a high-pH environment causing the precipitation of CaCO3 and metal hydroxides. The use of citric acid prevented the formation of precipitates, but solubilisation and mobilisation of metal species were not sufficiently achieved. Metal removal was relevant when EDTA was used as the conditioning agent, and the electric potential was raised up to 0.8 V/cm. EDTA led to the formation of negatively charged complexes with metals which migrated towards the anode compartment by electromigration. This result shows that metal removal from sediments with high acid buffering capacity may be achieved by enhancing the electrokinetic process by EDTA addition when the acidification of the medium is not economically and/or environmentally sustainable.

Field Testing of Rapid Electrokinetic Nanoparticle Treatment for Corrosion Control of Steel in Concrete

Science.gov (United States)

Cardenas, Henry E.; Alexander, Joshua B.; Kupwade-Patil,Kunal; Calle, Luz Marina

2009-01-01

This work field tested the use of electrokinetics for delivery of concrete sealing nanoparticles concurrent with the extraction of chlorides. Several cylinders of concrete were batched and placed in immersion at the Kennedy Space Center Beach Corrosion Test Site. The specimens were batched with steel reinforcement and a 4.5 wt.% (weight percent) content of sodium chloride. Upon arrival at Kennedy Space Center, the specimens were placed in the saltwater immersion pool at the Beach Corrosion Test Site. Following 30 days of saltwater exposure, the specimens were subjected to rapid chloride extraction concurrent with electrokinetic nanoparticle treatment. The treatments were operated at up to eight times the typical current density in order to complete the treatment in 7 days. The findings indicated that the short-term corrosion resistance of the concrete specimens was significantly enhanced as was the strength of the concrete.

Electrokinetic migration studies on removal of chromium and uranyl ions from 904-A trench soil

International Nuclear Information System (INIS)

Bibler, J.P.; Meaker, T.F.; O'Steen, A.B.

1992-01-01

This report describes a laboratory-scale study, in which electrokinetic migration technology was used to remove chromium and uranium, as well as other ions, from soil taken from a bore hole adjacent to the 904-A trench at the Savannah River Technology Center. Imposition of an electric current on humid (not saturated) soil successfully caused cations to migrate through the pore water of the soil to the cathode, where they were captured in an ISOLOCKTm polymer matrix and in a cation exchange resin incorporated in the polymer. Chemicals circulated through the anode/polymer and cathode/polymer were able to control pH excursions in the electrokinetic-cells by reacting with the H + and OH - generated at the anode and cathode, respectively. The study indicates that ions adsorbed on the surface of the soil as well as those in the pores of soil particles can be caused to migrate through the soil to an appropriate electrode. After 10 days of operation at 20--25 V and 2 mA, approximately 65% of the chromium was removed from two 3.5 kg soil samples. A 57% removal of uranium was achieved. The study shows that electrokinetic migration, using the ISOLOCK trademark polymer will be effective as an in situ treatment method for the removal of metal ion contaminants in soil adjacent to the 904-A trench

Coupled Electrokinetics-Adsorption Technique for Simultaneous Removal of Heavy Metals and Organics from Saline-Sodic Soil

Science.gov (United States)

Lukman, Salihu; Essa, Mohammed Hussain; Mu'azu, Nuhu Dalhat; Bukhari, Alaadin

2013-01-01

In situ remediation technologies for contaminated soils are faced with significant technical challenges when the contaminated soil has low permeability. Popular traditional technologies are rendered ineffective due to the difficulty encountered in accessing the contaminants as well as when employed in settings where the soil contains mixed contaminants such as petroleum hydrocarbons, heavy metals, and polar organics. In this study, an integrated in situ remediation technique that couples electrokinetics with adsorption, using locally produced granular activated carbon from date palm pits in the treatment zones that are installed directly to bracket the contaminated soils at bench-scale, is investigated. Natural saline-sodic soil, spiked with contaminant mixture (kerosene, phenol, Cr, Cd, Cu, Zn, Pb, and Hg), was used in this study to investigate the efficiency of contaminant removal. For the 21-day period of continuous electrokinetics-adsorption experimental run, efficiency for the removal of Zn, Pb, Cu, Cd, Cr, Hg, phenol, and kerosene was found to reach 26.8, 55.8, 41.0, 34.4, 75.9, 92.49, 100.0, and 49.8%, respectively. The results obtained suggest that integrating adsorption into electrokinetic technology is a promising solution for removal of contaminant mixture from saline-sodic soils. PMID:24235885

Coupled Electrokinetics-Adsorption Technique for Simultaneous Removal of Heavy Metals and Organics from Saline-Sodic Soil

Directory of Open Access Journals (Sweden)

Salihu Lukman

2013-01-01

Full Text Available In situ remediation technologies for contaminated soils are faced with significant technical challenges when the contaminated soil has low permeability. Popular traditional technologies are rendered ineffective due to the difficulty encountered in accessing the contaminants as well as when employed in settings where the soil contains mixed contaminants such as petroleum hydrocarbons, heavy metals, and polar organics. In this study, an integrated in situ remediation technique that couples electrokinetics with adsorption, using locally produced granular activated carbon from date palm pits in the treatment zones that are installed directly to bracket the contaminated soils at bench-scale, is investigated. Natural saline-sodic soil, spiked with contaminant mixture (kerosene, phenol, Cr, Cd, Cu, Zn, Pb, and Hg, was used in this study to investigate the efficiency of contaminant removal. For the 21-day period of continuous electrokinetics-adsorption experimental run, efficiency for the removal of Zn, Pb, Cu, Cd, Cr, Hg, phenol, and kerosene was found to reach 26.8, 55.8, 41.0, 34.4, 75.9, 92.49, 100.0, and 49.8%, respectively. The results obtained suggest that integrating adsorption into electrokinetic technology is a promising solution for removal of contaminant mixture from saline-sodic soils.

Electrokinetically Emplaced Amendments for Enhanced Bioremediation of Chlorinated Solvents in Clay: a Pilot Field Test

Science.gov (United States)

O'Carroll, D. M.; Inglis, A.; Head, N.; Chowdhury, A. I.; Garcia, A. N.; Reynolds, D. A.; Hogberg, D.; Edwards, E.; Lomheim, L.; Austrins, L. M.; Hayman, J.; Auger, M.; Sidebottom, A.; Eimers, J.; Gerhard, J.

2017-12-01

Bioremediation is an increasingly popular treatment technology for contaminated sites due to the proven success of biostimulation and bioaugmentation. However, bioremediation, along with other in-situ remediation technologies, faces limitations due to challenges with amendment delivery in low permeability media. Studies have suggested that electrokinetics (EK) can enhance the delivery of amendments in low permeability soils, such as clay. A pilot field trial was conducted to evaluate the potential for electrokinetics to support anaerobic dechlorination in clay by improving the transport of lactate and microorganisms. The study was performed on a former chlorinated solvent production facility in Ontario, Canada. Five transect cells were set up within the contaminated clay test area. Different amendments were injected in three of these cells to test various remediation strategies under the influence of EK. The other two cells were used as controls, one with EK applied and the other with no EK. This study focuses on the cell that applied electrokinetics for lactate emplacement followed by bioremediation (EK-Bio). This cell had an initial single injection of KB-1 bioaugmentation culture (SiREM, Canada) followed by injection of sodium lactate as a biostimulant while direct current was applied for 45 days between two electrodes 3 m apart. EK can enhance lactate migration by electromigration, while microorganisms have the potential to be influenced by electroosmosis of the bulk fluid or by electrophoresis of the charged bacteria themselves. All monitoring well locations in the EK-Bio cell exhibited evidence of successful lactate delivery corresponding to an increase in dissolved organic carbon. Reduction in chlorinated volatile organic compound (cVOC) concentrations, in particular 1,2-dichloroethane (1,2-DCA), were evident in monitoring locations coinciding with significant lactate breakthrough. Further investigation into the influence of EK-Bio on the abundance and

Pump effect of a capillary discharge in electrically conductive liquids

Czech Academy of Sciences Publication Activity Database

De Baerdemaeker, F.; Šimek, Milan; Leys, C.; Verstraete, W.

2007-01-01

Roč. 27, č. 4 (2007), s. 473-485 ISSN 0272-4324 R&D Projects: GA AV ČR IAA1043403 Institutional research plan: CEZ:AV0Z20430508 Keywords : water * conductive * capillary * AC discharge * pump Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 1.747, year: 2007 http://www.springerlink.com/content/w802073563282272/fulltext.pdf

Selecting enhancing solutions for electrokinetic remediation of dredged sediments polluted with fuel.

Science.gov (United States)

Rozas, F; Castellote, M

2015-03-15

In this paper a procedure for selecting the enhancing solutions in electrokinetic remediation experiments is proposed. For this purpose, dredged marine sediment was contaminated with fuel, and a total of 22 different experimental conditions were tested, analysing the influence of different enhancing solutions by using three commercial non-ionic surfactants, one bio-surfactant, one chelating agent, and one weak acid. Characterisation, microelectrophoretic and electrokinetic remediation trials were carried out. The results are explained on the basis of the interactions between the fuel, the enhancing electrolytes and the matrix. For one specific system, the electrophoretic zeta potential, (ζ), of the contaminated matrix in the solution was found to be related to the electroosmotic averaged ζ in the experiment and not to the efficiency in the extraction. This later was correlated to a parameter accounting for both contributions, the contaminant and the enhancing solution, calculated on the basis of differences in the electrophoretic ζ in different conditions which has allowed to propose a methodology for selection of enhancing solutions. Copyright © 2014 Elsevier Ltd. All rights reserved.

Microemulsion Electrokinetic Chromatography.

Science.gov (United States)

Buchberger, Wolfgang

2016-01-01

Microemulsion electrokinetic chromatography (MEEKC) is a special mode of capillary electrophoresis employing a microemulsion as carrier electrolyte. Analytes may partition between the aqueous phase of the microemulsion and its oil droplets which act as a pseudostationary phase. The technique is well suited for the separation of neutral species, in which case charged oil droplets (obtained by addition of an anionic or cationic surfactant) are present. A single set of separation parameters may be sufficient for separation of a wide range of analytes belonging to quite different chemical classes. Fine-tuning of resolution and analysis time may be achieved by addition of organic solvents, by changes in the nature of the surfactants (and cosurfactants) used to stabilize the microemulsion, or by various additives that may undergo some additional interactions with the analytes. Besides the separation of neutral analytes (which may be the most important application area of MEEKC), it can also be employed for cationic and/or anionic species. In this chapter, MEEKC conditions are summarized that have proven their reliability for routine analysis. Furthermore, the mechanisms encountered in MEEKC allow an efficient on-capillary preconcentration of analytes, so that the problem of poor concentration sensitivity of ultraviolet absorbance detection is circumvented.

Electrokinetic remediation of anionic contaminants from unsaturated soils

International Nuclear Information System (INIS)

Lindgren, E.R.; Kozak, M.W.; Mattson, E.D.

1992-01-01

Heavy-metal contamination of soil and groundwater is a widespread problem in the DOE weapons complex, and for the nation as a whole. Electrokinetic remediation is one possible technique for in situ removal of such contaminants from unsaturated soils. In previous studies at Sandia National Laboratories, the electromigration of chromate ions and anionic dye ions have been demonstrated. This paper reports on a series of experiments that were conducted to study the effect of moisture content on the electromigration rate of anionic contaminants in unsaturated soil and determine the limiting moisture content for which electromigration occurs

ELECTROKINETIC DENSIFICATION OF COAL FINES IN WASTE PONDS

Energy Technology Data Exchange (ETDEWEB)

E. James Davis

1999-12-18

The objective of this research was to demonstrate that electrokinetics can be used to remove colloidal coal and mineral particles from coal-washing ponds and lakes without the addition of chemical additives such as salts and polymeric flocculants. The specific objectives were: Design and develop a scaleable electrophoresis apparatus to clarify suspensions of colloidal coal and clay particles; Demonstrate the separation process using polluted waste water from the coal-washing facilities at the coal-fired power plants in Centralia, WA; Develop a mathematical model of the process to predict the rate of clarification and the suspension electrical properties needed for scale up.

Electrokinetic remediation of contaminated soils: An update

International Nuclear Information System (INIS)

Lindgren, E.R.; Kozak, M.W.; Mattson, E.D.

1992-01-01

Electrokinetic remediation of chromium contaminated soil has been demonstrated for unsaturated 50-100 mesh sand with 10% moisture by weight. The initial region of sand contaminated with 100 ppm w chromate ions was completely cleansed of contamination. After 22 hours of treatment, chromate was found near the anode and apparently migrated at a rate of at least 0.40 cm/hr with a pore water current density of 2.26mA/cm 2 . An analogous run was made using the same sand and FD and C Red No. 40 as the contaminant at a molar concentration equivalent to the 100 ppm w Cr run. The position of the migrating dye was monitored photographically. After similar treatment conditions, the visual dye concentration profile exhibited characteristics similar to the chromate. The migration rate of the dye was slower than the chromate but the qualitative similarity of behavior in an electric field suggests the dye is an analog for chromate ions. The slower migration rate of the dye is not unexpected because the dye molecule is larger than chromate. The use of dye as an analog for chromate greatly accelerates the experimentation process in unsaturated soil because destructive sampling is not required to monitor the contaminant location. Experiments were also conducted to determine the effect of soil heterogeneities on the electrokinetic processes. Unsaturated sands in size fractions of 50-100 mesh (medium) and 100-200 mesh (fine) were studied both individually and in layers. The dye migration rate was accelerated in the tine sand and slowed in the medium sand of the layered experiment when compared with the corresponding individual experiments. This discrepancy was explained by estimating the current density in each layer which was proportionally higher in the fine layer and lower in the medium layer. These preliminary experiments illustrate the significant dependence of electromigration rates on current density. (author)

Electrokinetics of diffuse soft interfaces. III. Interpretation of data on the polyacrylamide/water interface

NARCIS (Netherlands)

Yezek, L.P.; Duval, J.F.L.; Leeuwen, van H.P.

2005-01-01

Streaming potential measurements were carried out on a family of polyacrylamide-co-sodium acrylate gels cross-linked with N,N¿- methylenebisacrylamide in a homemade electrokinetic cell. Measurements of the ionic conductivity within thin films of these gels allowed the equilibrium Donnan potential

Atmospheric pressure photoionization for enhanced compatibility in on-line micellar electrokinetic chromatography-mass spectrometry

NARCIS (Netherlands)

Mol, Roelof; De Jong, Gerhardus J.; Somsen, Govert W.

2005-01-01

Atmospheric pressure photoionization (APPI) is presented as a novel means for the combination of micellar electrokinetic chromatography (MEKC) and mass spectrometry (MS). The on-line coupling is achieved using an adapted sheath flow interface installed on an orthogonal APPI source. Acetone or

Effect of Wetting Agents and Approaching Anodes on Lead Migration in Electrokinetic Soil Remediation

OpenAIRE

Ng, Yee-Sern; Gupta, Bhaskar Sen; Hashim, Mohd Ali

2015-01-01

This is the presentation slides for my conference paper "Effect of Wetting Agents and Approaching Anodes on Lead Migration in Electrokinetic Soil Remediation", which was presented in 5th International Conference on Chemical Engineering and Applications, Taipei on 27 August 2014.

Alternating-current MHD conduction pump for ferrous metals

International Nuclear Information System (INIS)

Nadezhnikov, N.M.; Krauya, V.M.; Yankop, E.K.

1979-01-01

Results are presented of theoretical and experimental studies pertaining to an ac MHD conduction pump with separate excitation and a C-core magnet structure. Its mathematical model is based on the following assumptions: (1) During complete braking the liquid metal in the channel is stationary; (2) there is no current leakage in the channel beyond the interelectrode region; (3) during operation the longitudinal axis of the pump is in a vertical position; (4) the current density in the electrodes at a distance infinitely far from the active channel segment is uniformly distributed; (5) there are no magnetic leakage fluxes in the model; and (6) the left-hand electrode in the model can be brought out in two different ways, variant I or variant II. 7 references

Electrokinetic Enhanced Permanganate Delivery for Low Permeability Soil Remediation

Science.gov (United States)

Chowdhury, A. I.; Gerhard, J.; Reynolds, D. A.; Sleep, B. E.; O'Carroll, D. M.

2016-12-01

Contaminant mass sequestered in low permeability zones (LPZ) in the subsurface has become a significant concern due to back diffusion of contaminants, leading to contaminant rebound following treatment of the high permeability strata. In-situ remediation technologies such as in-situ chemical oxidation (ISCO) are promising, however, successful delivery of oxidants into silts and clays remains a challenge. Electrokinetics (EK) has been proposed as a technique that can overcome this challenge by delivering oxidants into low permeability soils. This study demonstrates the ability of EK to facilitate permanganate delivery into silt for treatment of trichloroethene (TCE). A two-dimensional sandbox was packed with alternate vertical layers of coarse sand and silt contaminated with high concentrations of aqueous phase TCE. Nine experiments were conducted to compare EK-enhanced in-situ chemical oxidation (EK-ISCO) to ISCO alone or EK alone. Frequent groundwater sampling at multiple locations combined with image analysis provided detailed mapping of TCE, permanganate, and manganese dioxide mass distributions. EK-ISCO successfully delivered the permanganate throughout the silt cross-section while ISCO without EK resulted in permanganate delivery only to the edges of the silt layer. EK-ISCO resulted in a 4.4 order-of-magnitude (OoM) reduction in TCE concentrations in the coarse sand compared to a 3.5 OoM reduction for ISCO alone. This study suggests that electrokinetics coupled with ISCO can achieve enhanced remediation of lower permeability strata, where remediation technologies for successful contaminant mass removal would otherwise be limited.

Feasibility of electrokinetic oxygen supply for soil bioremediation purposes.

Science.gov (United States)

Mena Ramírez, E; Villaseñor Camacho, J; Rodrigo Rodrigo, M A; Cañizares Cañizares, P

2014-12-01

This paper studies the possibility of providing oxygen to a soil by an electrokinetic technique, so that the method could be used in future aerobic polluted soil bioremediation treatments. The oxygen was generated from the anodic reaction of water electrolysis and transported to the soil in a laboratory-scale electrokinetic cell. Two variables were tested: the soil texture and the voltage gradient. The technique was tested in two artificial soils (clay and sand) and later in a real silty soil, and three voltage gradients were used: 0.0 (control), 0.5, and 1.0 V cm(-1). It was observed that these two variables strongly influenced the results. Oxygen transport into the soil was only available in the silty and sandy soils by oxygen diffusion, obtaining high dissolved oxygen concentrations, between 4 and 9 mg L(-1), useful for possible aerobic biodegradation processes, while transport was not possible in fine-grained soils such as clay. Electro-osmotic flow did not contribute to the transport of oxygen, and an increase in voltage gradients produced higher oxygen transfer rates. However, only a minimum fraction of the electrolytically generated oxygen was efficiently used, and the maximum oxygen transport rate observed, approximately 1.4 mgO2 L(-1)d(-1), was rather low, so this technique could be only tested in slow in-situ biostimulation processes for organics removal from polluted soils. Copyright © 2014 Elsevier Ltd. All rights reserved.

Effect of physical, chemical and electro-kinetic properties of pumice samples on radiation shielding properties of pumice material

International Nuclear Information System (INIS)

Tapan, Mücip; Yalçın, Zeynel; İçelli, Orhan; Kara, Hüsnü; Orak, Salim; Özvan, Ali; Depci, Tolga

2014-01-01

Highlights: • Radiation shielding properties of pumice materials are studied. • The relationship between physical, chemical and electro-kinetic properties pumice samples is identified. • The photon atomic parameters are important for the absorber peculiarity of the pumices. - Abstract: Pumice has been used in cement, concrete, brick, and ceramic industries as an additive and aggregate material. In this study, some gamma-ray photon absorption parameters such as the total mass attenuation coefficients, effective atomic number and electronic density have been investigated for six different pumice samples. Numerous values of energy related parameters from low energy (1 keV) to high energy (100 MeV) were calculated using WinXCom programme. The relationship between radiation shielding properties of the pumice samples and their physical, chemical and electro-kinetic properties was evaluated using simple regression analysis. Simple regression analysis indicated a strong correlation between photon energy absorption parameters and density and SiO 2 , Fe 2 O 3 , CaO, MgO, TiO 2 content of pumice samples in this study. It is found that photon energy absorption parameters are not related to electro-kinetic properties of pumice samples

Physicochemical and numerical modeling of electrokinetics in inhomogenous matrices

DEFF Research Database (Denmark)

Paz-Garcia, Juan Manuel

A physicochemical model has been proposed based on the Nernst-Planck-Poisson system. The model includes the transport of water through the porous media, the monitoring of the degree of saturation, the pH value and the porosity throughout the domain; and a comprehensive set of chemical and electrochemical reactions...... is mainly based on a finite elements method for the integration of the transient system of partial differential equations coupled with a Newton-Raphson method for computing chemical equilibrium. During the development of the proposed physicochemical and numerical model, different electrokinetic systems have...

Electrokinetics of diffuse soft interfaces. 2. Analysis based on the nonlinear Poisson-Boltzmann equation

NARCIS (Netherlands)

Duval, J.F.L.

2005-01-01

In a previous study (Langmuir 2004, 20, 10324), the electrokinetic properties of diffuse soft layers were theoretically investigated within the framework of the Debye-H¿ckel approximation valid in the limit of sufficiently low values for the Donnan potential. In the current paper, the

Simultaneous removal of organic contaminants and heavy metals from kaolin using an upward electrokinetic soil remediation process

International Nuclear Information System (INIS)

Wang, J.-Y.; Huang, X.-J.; Kao, Jimmy C.M.; Stabnikova, Olena

2007-01-01

Kaolins contaminated with heavy metals, Cu and Pb, and organic compounds, p-xylene and phenanthrene, were treated with an upward electrokinetic soil remediation (UESR) process. The effects of current density, cathode chamber flushing fluid, treatment duration, reactor size, and the type of contaminants under the vertical non-uniform electric field of UESR on the simultaneous removal of the heavy metals and organic contaminants were studied. The removal efficiencies of p-xylene and phenanthrene were higher in the experiments with cells of smaller diameter or larger height, and with distilled water flow in the cathode chamber. The removal efficiency of Cu and Pb were higher in the experiments with smaller diameter or shorter height cells and 0.01 M HNO 3 solution as cathode chamber flow. In spite of different conditions for removal of heavy metals and organics, it is possible to use the upward electrokinetic soil remediation process for their simultaneous removal. Thus, in the experiments with duration of 6 days removal efficiencies of phenanthrene, p-xylene, Cu and Pb were 67%, 93%, 62% and 35%, respectively. The experiment demonstrated the feasibility of simultaneous removal of organic contaminants and heavy metals from kaolin using the upward electrokinetic soil remediation process

Increased Ac excision (iae): Arabidopsis thaliana mutations affecting Ac transposition

International Nuclear Information System (INIS)

Jarvis, P.; Belzile, F.; Page, T.; Dean, C.

1997-01-01

The maize transposable element Ac is highly active in the heterologous hosts tobacco and tomato, but shows very much reduced levels of activity in Arabidopsis. A mutagenesis experiment was undertaken with the aim of identifying Arabidopsis host factors responsible for the observed low levels of Ac activity. Seed from a line carrying a single copy of the Ac element inserted into the streptomycin phosphotransferase (SPT) reporter fusion, and which displayed typically low levels of Ac activity, were mutagenized using gamma rays. Nineteen mutants displaying high levels of somatic Ac activity, as judged by their highly variegated phenotypes, were isolated after screening the M2 generation on streptomycin-containing medium. The mutations fall into two complementation groups, iae1 and iae2, are unlinked to the SPT::Ac locus and segregate in a Mendelian fashion. The iae1 mutation is recessive and the iae2 mutation is semi-dominant. The iae1 and iae2 mutants show 550- and 70-fold increases, respectively, in the average number of Ac excision sectors per cotyledon. The IAE1 locus maps to chromosome 2, whereas the SPT::Ac reporter maps to chromosome 3. A molecular study of Ac activity in the iae1 mutant confirmed the very high levels of Ac excision predicted using the phenotypic assay, but revealed only low levels of Ac re-insertion. Analyses of germinal transposition in the iae1 mutant demonstrated an average germinal excision frequency of 3% and a frequency of independent Ac re-insertions following germinal excision of 22%. The iae mutants represents a possible means of improving the efficiency of Ac/Ds transposon tagging systems in Arabidopsis, and will enable the dissection of host involvement in Ac transposition and the mechanisms employed for controlling transposable element activity

Electrokinetic remediation of a copper contaminated soil - experiments and 1-D model

Energy Technology Data Exchange (ETDEWEB)

Vereda Alonso, C.; Hansen, H.K. [Inst. for Geologi and Geoteknik, Danmarks Tekniske Univ., Lyngby (Denmark); Gomez Lahoz, C.; Rodriguez Maroto, J.M. [Dept. de Ingenieria Quimica, Univ. de Malaga (Spain)

2001-07-01

In this work, a set of electrokinetic soil remediation experiments has been performed in a column containing a commercial standard kaolin that was previously contaminated with copper. The profile evolution of copper concentration and pH along the soil column was obtained from these experiments. A one-dimensional numerical model has been developed to simulate the experimental results obtained from these experiments. (orig.)

A case of biliary stones and anastomotic biliary stricture after liver transplant treated with the rendez - vous technique and electrokinetic lithotritor

Institute of Scientific and Technical Information of China (English)

Marta Di Pisa; Mario Traina; Roberto Miraglia; Luigi Maruzzelli; Riccardo Volpes; Salvatore Piazza; Angelo Luca; Bruno Gridelli

2008-01-01

The paper studies the combined radiologic and endoscopic approach (rendezvous technique) to the treatment of the biliary complications following liver transplant. The "rendez-vous" technique was used with an electrokinetic lithotripter, in the treatment of a biliary anastomotic stricture with multiple biliary stones in a patient who underwent orthotopic liver transplant. In this patient, endoscopic or percutaneous transhepatic management of the biliary complication failed. The combined approach, percutaneous transhepatic and endoscopic treatment (rendez-vous technique) with the use of an electrokinetic lithotritor, was used to solve the biliary stenosis and to remove the stones.Technical success, defined as disappearance of the biliary stenosis and stone removal, was obtained in just one session, which definitively solved the complications.The combined approach of percutaneous transhepatic and endoscopic (rendez-vous technique) treatment, in association with an electrokinetic lithotritor, is a safe and feasible alternative treatment, especially after the failure of endoscopic and/or percutaneous trans-hepatic isolated procedures.

Electrokinetic desalination of glazed ceramic tiles

DEFF Research Database (Denmark)

Ottosen, Lisbeth M.; Ferreira, Celia; Christensen, Iben Vernegren

2010-01-01

Electrokinetic desalination is a method where an applied electric DC field is the driving force for removal of salts from porous building materials. In the present paper, the method is tested in laboratory scale for desalination of single ceramic tiles. In a model system, where a tile...... was contaminated with NaCl during submersion and subsequently desalinated by the method, the desalination was completed in that the high and problematic initial Cl(-) concentration was reduced to an unproblematic concentration. Further conductivity measurements showed a very low conductivity in the tile after...... treatment, indicating that supply of ions from the poultice at the electrodes into the tile was limited. Electroosmotic transport of water was seen when low ionic content was reached. Experiments were also conducted with XVIII-century tiles, which had been removed from Palacio Centeno (Lisbon) during...

Control of electrode processes in electrokinetic soil remediation

Energy Technology Data Exchange (ETDEWEB)

Schmid, M.; Marb, C. [Bavarian State Office for Environmental Protection, Waste Technology Centre, Augsburg (Germany)

2001-07-01

Technical control of electrode processes induced by water electrolysis is crucial for the effectiveness of electrokinetic soil remediation. A calculation method for the quantification of electrolysis products is derived and its validity by the consumption of neutralizing agents verified. Steel rods used as sacrificial anodes instead of inert materials cannot counteract the acidification of the anolyte due to the acidic property of Fe-cations released as oxidation products. An an alternative to ordinary porous well materials a tubular cation exchange membrane was used as a cathode well. Thereby the migration of anions stemming from the catholyte neutralisation was hampered and no loss in the electric field strength occured. (orig.)

Adiabatic and non-adiabatic charge pumping in a single-level molecular motor

NARCIS (Netherlands)

Napitu, B.D.; Thijssen, J.M.

2015-01-01

We propose a design for realizing quantum charge pump based on a recent proposal for a molecular motor (Seldenthuis J S et al 2010 ACS Nano 4 6681). Our design is based on the presence of a moiety with a permanent dipole moment which can rotate, thereby modulating the couplings to metallic contacts

TRANSIENT AND STEADY STATE STUDY OF PURE AND MIXED REFRIGERANTS IN A RESIDENTIAL HEAT PUMP

Science.gov (United States)

The report gives results of an experimental and theoretical investigation of the transient and steady state performance of a residential air-conditioning/heat pump (AC/HP) operating with different refrigerants. (NOTE: The project was motivated by environmental concerns related to...

The Physical Behavior of Stabilised Soft Clay by Electrokinetic Stabilisation Technology

Science.gov (United States)

Azhar, A. T. S.; Nordin, N. S.; Azmi, M. A. M.; Embong, Z.; Sunar, N.; Hazreek, Z. A. M.; Aziman, M.

2018-04-01

Electrokinetic Stabilisation (EKS) technology is the combination processes of electroosmosis and chemical grouting. This technique is most effective in silty and clayey soils where the hydraulic conductivity is very low. Stabilising agents will assist the EKS treatment by inducing it into soil under direct current. The movement of stabilising agents into soil is governed by the principle of electrokinetics. The aim of this study is to evaluate the physical behavior of soft soil using the EKS technology as an effective method to strengthen soft clay soils with calcium chloride (CaCl2) as the stabilising agent. Stainless steel plates were used as the electrodes, while 1.0 mol/l of CaCl2 was used as the electrolyte that fed at the anode compartment. Soft marine clay at Universiti Tun Hussein Onn Malaysia was used as the soil sample. The EKS treatment was developed at Research Centre for Soft Soil (RECESS), UTHM with a constant voltage gradient (50 V/m) in 21 days. The result shows that the shear strength of treated soil was increased across the soil sample. The treated soil near the cathode showed the highest value of shear strength (24.5 – 33 kPa) compared with the anode and in the middle of the soil sample.

Remediation of Cd(II)-contaminated soil via humin-enhanced electrokinetic technology.

Science.gov (United States)

Ding, Ling; Lv, Wenying; Yao, Kun; Li, Liming; Wang, Mengmeng; Liu, Guoguang

2017-02-01

Humin is the component of humic substances that is recalcitrant to extraction by either strong bases or strong acids, which contains a variety of functional groups that may combine with heavy metal ions. The present study employed humin as an adsorbent to investigate the efficacy of a remediation strategy under the effects of humin-enhanced electrokinetics. Because the cations gravitate toward cathode and anions are transferred to anode, humin was placed in close proximity to the cathode in the form of a package. The humin was taken out after the experiments to determine whether a target pollutant (cadmium) might be completely removed from soil. Acetic acid-sodium acetate was selected as the electrolyte for these experiments, which was circulated between the two electrode chambers via a peristaltic pump, in order to control the pH of the soil. The results indicated that when the remediation duration was extended to 240 h, the removal of acid extractable Cd(II) could be up to 43.86% efficiency, and the adsorption of the heavy metal within the humin was 86.15 mg/kg. Further, the recycling of the electrolyte exhibited a good control of the pH of the soil. When comparing the pH of the soil with the circulating electrolyte during remediation, in contrast to when it was not being recycled, the pH of the soil at the anode increased from 3.89 to 5.63, whereas the soil at the cathode decreased from 8.06 to 7.10. This indicated that the electrolyte recycling had the capacity to stabilize the pH of the soil.

Chelating agent-assisted electrokinetic removal of cadmium, lead and copper from contaminated soils

International Nuclear Information System (INIS)

Giannis, Apostolos; Nikolaou, Aris; Pentari, Despina; Gidarakos, Evangelos

2009-01-01

An integrated experimental program was conducted to remove Cd, Pb and Cu from contaminated soil. The chelate agents nitrilotriacetic acid (NTA), diethylenetriamine pentaacetic acid (DTPA) and ethyleneglycol tetraacetic acid (EGTA) were used as washing solutions under different pH conditions and concentrations. Results showed that the extraction efficiency for Cd in decreasing order was NTA > EGTA > DTPA, while for Pb and Cu it was DTPA > NTA > EGTA. The use of higher chelate concentrations did not necessarily result in greater extraction efficiency. Electrokinetic remediation was applied by conditioning anolyte-catholyte pH to neutral values in order to avoid any potential alterations to the physicochemical soil properties. The removal efficiency for Cd was 65-95%, for Cu 15-60%, but for Pb was less than 20%. The phytotoxicity of the treated soil showed that the soil samples from the anode section were less phytotoxic than the untreated soil, but the phytotoxicity was increased in the samples from the cathode section. - Cadmium, lead and copper were extracted from contaminated soil by integrated electrokinetic and soil washing studies.

Chelating agent-assisted electrokinetic removal of cadmium, lead and copper from contaminated soils

Energy Technology Data Exchange (ETDEWEB)

Giannis, Apostolos, E-mail: apostolos.giannis@enveng.tuc.g [Laboratory of Toxic and Hazardous Waste Management, Department of Environmental Engineering, Technical University of Crete, Politechnioupolis, Chania 73100 (Greece); Nikolaou, Aris [Laboratory of Toxic and Hazardous Waste Management, Department of Environmental Engineering, Technical University of Crete, Politechnioupolis, Chania 73100 (Greece); Pentari, Despina [Laboratory of Inorganic and Organic Geochemistry and Organic Petrography, Department of Mineral Resources Engineering, Technical University of Crete, Politechnioupolis, Chania 73100 (Greece); Gidarakos, Evangelos, E-mail: gidarako@mred.tuc.g [Laboratory of Toxic and Hazardous Waste Management, Department of Environmental Engineering, Technical University of Crete, Politechnioupolis, Chania 73100 (Greece)

2009-12-15

An integrated experimental program was conducted to remove Cd, Pb and Cu from contaminated soil. The chelate agents nitrilotriacetic acid (NTA), diethylenetriamine pentaacetic acid (DTPA) and ethyleneglycol tetraacetic acid (EGTA) were used as washing solutions under different pH conditions and concentrations. Results showed that the extraction efficiency for Cd in decreasing order was NTA > EGTA > DTPA, while for Pb and Cu it was DTPA > NTA > EGTA. The use of higher chelate concentrations did not necessarily result in greater extraction efficiency. Electrokinetic remediation was applied by conditioning anolyte-catholyte pH to neutral values in order to avoid any potential alterations to the physicochemical soil properties. The removal efficiency for Cd was 65-95%, for Cu 15-60%, but for Pb was less than 20%. The phytotoxicity of the treated soil showed that the soil samples from the anode section were less phytotoxic than the untreated soil, but the phytotoxicity was increased in the samples from the cathode section. - Cadmium, lead and copper were extracted from contaminated soil by integrated electrokinetic and soil washing studies.

Sludge reduction in a small wastewater treatment plant by electro-kinetic disintegration.

Science.gov (United States)

Chiavola, Agostina; Ridolfi, Alessandra; D'Amato, Emilio; Bongirolami, Simona; Cima, Ennio; Sirini, Piero; Gavasci, Renato

2015-01-01

Sludge reduction in a wastewater treatment plant (WWTP) has recently become a key issue for the managing companies, due to the increasing constraints on the disposal alternatives. Therefore, all the solutions proposed with the aim of minimizing sludge production are receiving increasing attention and are tested either at laboratory or full-scale to evaluate their real effectiveness. In the present paper, electro-kinetic disintegration has been applied at full-scale in the recycle loop of the sludge drawn from the secondary settlement tank of a small WWTP for domestic sewage. After the disintegration stage, the treated sludge was returned to the biological reactor. Three different percentages (50, 75 and 100%) of the return sludge flow rate were subjected to disintegration and the effects on the sludge production and the WWTP operation efficiency evaluated. The long-term observations showed that the electro-kinetic disintegration was able to drastically reduce the amount of biological sludge produced by the plant, without affecting its treatment efficiency. The highest reduction was achieved when 100% return sludge flow rate was subjected to the disintegration process. The reduced sludge production gave rise to a considerable net cost saving for the company which manages the plant.

AC Initiation System.

Science.gov (United States)

An ac initiation system is described which uses three ac transmission signals interlocked for safety by frequency, phase, and power discrimination...The ac initiation system is pre-armed by the application of two ac signals have the proper phases, and activates a load when an ac power signal of the proper frequency and power level is applied. (Author)

Integrating Electrokinetic and Bioremediation Process for Treating Oil Contaminated Low Permeability Soil

OpenAIRE

Surya Ramadan Bimastyaji; Jatnika Effendi Agus; Helmy Qomarudin

2018-01-01

Traditional oil mining activities always ignores environmental regulation which may cause contamination in soil and environment. Crude oil contamination in low-permeability soil complicates recovery process because it requires substantial energy for excavating and crushing the soil. Electrokinetic technology can be used as an alternative technology to treat contaminated soil and improve bioremediation process (biostimulation) through transfer of ions and nutrient that support microorganism gr...

Evolution of microbial communities during electrokinetic treatment of antibiotic-polluted soil.

Science.gov (United States)

Li, Hongna; Li, Binxu; Zhang, Zhiguo; Zhu, Changxiong; Tian, Yunlong; Ye, Jing

2018-02-01

The evolution of microbial communities during the electrokinetic treatment of antibiotic-polluted soil (EKA) was investigated with chlortetracycline (CTC), oxytetracycline (OTC) and tetracycline (TC) as template antibiotics. The total population of soil microorganisms was less affected during the electrokinetic process, while living anti-CTC, anti-OTC, anti-TC and anti-MIX bacteria were inactivated by 10.48%, 31.37%, 34.76%, and 22.08%, respectively, during the 7-day treatment compared with antibiotic-polluted soil without an electric field (NOE). Accordingly, samples with NOE treatment showed a higher Shannon index than those with EKA treatment, indicating a reduction of the microbial community diversity after electrokinetic processes. The major taxonomic phyla found in the samples of EKA and NOE treatment were Proteobacteria, Bacteroidetes, Firmicutes and Actinobacteria. And the distribution of Actinobacteria, Cyanobacteria, and Chloroflexi was greatly decreased compared with blank soil. In the phylum Proteobacteria, the abundance of Alphaproteobacteria was greatly reduced in the soils supplemented with antibiotics (from 13.40% in blank soil to 6.43-10.16% after treatment); while Betaproteobacteria and Deltaproteobacteria showed a different trend with their abundance increased compared to blank soil, and Gammaproteobacteria remained unchanged for all treatments (2.36-2.78%). The varied trends for different classes indicated that the major bacterial groups changed with the treatments due to their different adaptability to the antibiotics as well as to the electric field. SulI being an exception, the reduction ratio of the observed antibiotic resistance genes (ARGs) including tetC, tetG, tetW, tetM, intI1, and sulII in the 0-2cm soil sampled with EKA versus NOE treatment reached 55.17%, 3.59%, 99.26%, 89.51%, 30.40%, and 27.92%, respectively. Finally, correlation analysis was conducted between antibiotic-resistant bacteria, ARGs and taxonomic bacterial classes. It

Electrokinetic characteristics fused quartz in solutions of 1:1, 2:1 and 3:1 charge electrolytes

International Nuclear Information System (INIS)

Bogdanova, N.F.; Sidorova, M.P.; Ermakova, L.Eh.; Savina, I.A.

1997-01-01

Electrokinetic characteristics of silicon oxide have been studied using a model system - a plane-parallel capillary in chloride solutions containing mono-(H + , Na + , Cs + ), two-(Ba 2+ ) and three-(La 3+ ) charge counterions in a wide range of pH and concentrations. It has been revealed that isoelectric point (IEP) of silicon oxide studied coincides with the one usually quoted in literature and corresponds to pH2 in the absence of specific adsorption. Specific adsorption of cesium ions resulting in IEP displacement to pH 3.3 at the back-ground of 0.1M CsCl solution has been detected. Specific adsorption of lanthanum ions increases with increase in the surface charge, involving appearance of a positive electrokinetic potential range at pH>3.3 at the background of 0.1g-eq/l LaCl 3 solution

Study on ac losses of HTS coil carrying ac transport current

International Nuclear Information System (INIS)

Dai Taozhen; Tang Yuejin; Li Jingdong; Zhou Yusheng; Cheng Shijie; Pan Yuan

2005-01-01

Ac loss has an important influence on the thermal performances of HTS coil. It is necessary to quantify ac loss to ascertain its impact on coil stability and for sizing the coil refrigeration system. In this paper, we analyzed in detail the ac loss components, hysteresis loss, eddy loss and flux flow loss in the pancake HTS coil carrying ac transport current by finite element method. We also investigated the distribution of the ac losses in the coil to study the effects of magnetic field distribution on ac losses

Multi-phase AC/AC step-down converter for distribution systems

Science.gov (United States)

Aeloiza, Eddy C.; Burgos, Rolando P.

2017-10-25

A step-down AC/AC converter for use in an electric distribution system includes at least one chopper circuit for each one of a plurality of phases of the AC power, each chopper circuit including a four-quadrant switch coupled in series between primary and secondary sides of the chopper circuit and a current-bidirectional two-quadrant switch coupled between the secondary side of the chopper circuit and a common node. Each current-bidirectional two-quadrant switch is oriented in the same direction, with respect to the secondary side of the corresponding chopper circuit and the common node. The converter further includes a control circuit configured to pulse-width-modulate control inputs of the switches, to convert a first multiphase AC voltage at the primary sides of the chopper circuits to a second multiphase AC voltage at the secondary sides of the chopper circuits, the second multiphase AC voltage being lower in voltage than the first multiphase AC voltage.

Electrokinetic-enhanced bioaugmentation for remediation of chlorinated solvents contaminated clay

International Nuclear Information System (INIS)

Mao, Xuhui; Wang, James; Ciblak, Ali; Cox, Evan E.; Riis, Charlotte; Terkelsen, Mads; Gent, David B.; Alshawabkeh, Akram N.

2012-01-01

Highlights: ► Simultaneous delivery of electron donors and bacteria into low permeability clays. ► Bacteria injection, growth and consequent transformation of contaminants are viable. ► EK injection is more effective than advection-based injection for clay soil. ► Electroosmosis appears to be the driving mechanism for bacteria injection. ► Both EK transport and biodegradation contribute the removal of VOCs in clay. - Abstract: Successful bioremediation of contaminated soils is controlled by the ability to deliver bioremediation additives, such as bacteria and/or nutrients, to the contaminated zone. Because hydraulic advection is not practical for delivery in clays, electrokinetic (EK) injection is an alternative for efficient and uniform delivery of bioremediation additive into low-permeability soil and heterogeneous deposits. EK-enhanced bioaugmentation for remediation of clays contaminated with chlorinated solvents is evaluated. Dehalococcoides (Dhc) bacterial strain and lactate ions are uniformly injected in contaminated clay and complete dechlorination of chlorinated ethene is observed in laboratory experiments. The injected bacteria can survive, grow, and promote effective dechlorination under EK conditions and after EK application. The distribution of Dhc within the clay suggests that electrokinetic transport of Dhc is primarily driven by electroosmosis. In addition to biodegradation due to bioaugmentation of Dhc, an EK-driven transport of chlorinated ethenes is observed in the clay, which accelerates cleanup of chlorinated ethenes from the anode side. Compared with conventional advection-based delivery, EK injection is significantly more effective for establishing microbial reductive dechlorination capacity in low-permeability soils.

Diode-end-pumped Tm:GdVO4 laser operating at 1818 and 1915 nm

CSIR Research Space (South Africa)

Esser, MJD

2009-10-01

Full Text Available wavelengths. We therefore embarked on ac- curately measuring absorption spectra of Tm:GdVO4 laser crystals at both 0.8 (pump band) and at 1.9 µm (emission band). The measurements were conducted with a Cary 5000 spectrometer with resolution set to 1 nm...

ELECTROKINETIC DENSIFICATION OF COAL FINES IN WASTE PONDS

Energy Technology Data Exchange (ETDEWEB)

E. James Davis

1998-05-01

The objective of this research is to demonstrate that electrokinetics can be used to remove colloidal coal and mineral particles from coal-washing ponds and lakes without the addition of chemical additives such as salts and polymeric flocculants. In this experimental and analytical study the authors elucidate the transport processes that control the rate of concentrated colloidal particle removal, demonstrate the process on a laboratory scale, and develop the scale-up laws needed to design commercial-scale processes. The authors are also addressing the fundamental problems associated with particle-particle interactions (electrical and hydrodynamic), the effects of particle concentration on the applied electric field, the electrochemical reactions that occur at the electrodes, and the prediction of power requirements.

Sodium pumping: pump problems

International Nuclear Information System (INIS)

Guer, M.; Guiton, P.

Information on sodium pumps for LMFBR type reactors is presented concerning ring pump design, pool reactor pump design, secondary pumps, sodium bearings, swivel joints of the oscillating annulus, and thermal shock loads

78 FR 11996 - Energy Efficiency Program for Commercial and Industrial Equipment: Commercial and Industrial Pumps

Science.gov (United States)

2013-02-21

.... EERE-2011-BT-STD-0031] RIN 1904-AC54 Energy Efficiency Program for Commercial and Industrial Equipment: Commercial and Industrial Pumps AGENCY: Office of Energy Efficiency and Renewable Energy, Department of... CONTACT: Mr. Charles Llenza, U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy...

Copper and trace element fractionation in electrokinetically treated methanogenic anaerobic granular sludge

International Nuclear Information System (INIS)

Virkutyte, Jurate; Hullebusch, Eric van; Sillanpaeae, Mika; Lens, Piet

2005-01-01

The effect of electrokinetic treatment (0.15 mA cm -2 ) on the metal fractionation in anaerobic granular sludge artificially contaminated with copper (initial copper concentration 1000 mg kg -1 wet sludge) was studied. Acidification of the sludge (final pH 4.2 in the sludge bed) with the intention to desorb the copper species bound to the organic/sulfides and residual fractions did not result in an increased mobility, despite the fact that a higher quantity of copper was measured in the more mobile (i.e. exchangeable/carbonate) fractions at final pH 4.2 compared to circum-neutral pH conditions. Also addition of the chelating agent EDTA (Cu 2+ :EDTA 4- ratio 1.2:1) did not enhance the mobility of copper from the organic/sulfides and residual fractions, despite the fact that it induced a reduction of the total copper content of the sludge. The presence of sulfide precipitates likely influences the copper mobilisation from these less mobile fractions, and thus makes EDTA addition ineffective to solubilise copper from the granules. - Electrokinetic treatment of copper contaminated anaerobic granular sludge at 0.15 mA cm -2 for 14 days induces copper and trace metal mobility as well as changes in their fractionation (i.e. bonding forms)

Electrokinetic motion of a rectangular nanoparticle in a nanochannel

Energy Technology Data Exchange (ETDEWEB)

Movahed, Saeid; Li Dongqing, E-mail: dongqing@mme.uwaterloo.ca [University of Waterloo, Department of Mechanical and Mechatronics Engineering (Canada)

2012-08-15

This article presents a theoretical study of electrokinetic motion of a negatively charged cubic nanoparticle in a three-dimensional nanochannel with a circular cross-section. Effects of the electrophoretic and the hydrodynamic forces on the nanoparticle motion are examined. Because of the large applied electric field over the nanochannel, the impact of the Brownian force is negligible in comparison with the electrophoretic and the hydrodynamic forces. The conventional theories of electrokinetics such as the Poisson-Boltzmann equation and the Helmholtz-Smoluchowski slip velocity approach are no longer applicable in the small nanochannels. In this study, and at each time step, first, a set of highly coupled partial differential equations including the Poisson-Nernst-Plank equation, the Navier-Stokes equations, and the continuity equation was solved to find the electric potential, ionic concentration field, and the flow field around the nanoparticle. Then, the electrophoretic and hydrodynamic forces acting on the negatively charged nanoparticle were determined. Following that, the Newton second law was utilized to find the velocity of the nanoparticle. Using this model, effects of surface electric charge of the nanochannel, bulk ionic concentration, the size of the nanoparticle, and the radius of the nanochannel on the nanoparticle motion were investigated. Increasing the bulk ionic concentration or the surface charge of the nanochannel will increase the electroosmotic flow, and hence affect the particle's motion. It was also shown that, unlike microchannels with thin EDL, the change in nanochannel size will change the EDL field and the ionic concentration field in the nanochannel, affecting the particle's motion. If the nanochannel size is fixed, a larger particle will move faster than a smaller particle under the same conditions.

Electrokinetic motion of a rectangular nanoparticle in a nanochannel

International Nuclear Information System (INIS)

Movahed, Saeid; Li Dongqing

2012-01-01

This article presents a theoretical study of electrokinetic motion of a negatively charged cubic nanoparticle in a three-dimensional nanochannel with a circular cross-section. Effects of the electrophoretic and the hydrodynamic forces on the nanoparticle motion are examined. Because of the large applied electric field over the nanochannel, the impact of the Brownian force is negligible in comparison with the electrophoretic and the hydrodynamic forces. The conventional theories of electrokinetics such as the Poisson–Boltzmann equation and the Helmholtz–Smoluchowski slip velocity approach are no longer applicable in the small nanochannels. In this study, and at each time step, first, a set of highly coupled partial differential equations including the Poisson–Nernst–Plank equation, the Navier–Stokes equations, and the continuity equation was solved to find the electric potential, ionic concentration field, and the flow field around the nanoparticle. Then, the electrophoretic and hydrodynamic forces acting on the negatively charged nanoparticle were determined. Following that, the Newton second law was utilized to find the velocity of the nanoparticle. Using this model, effects of surface electric charge of the nanochannel, bulk ionic concentration, the size of the nanoparticle, and the radius of the nanochannel on the nanoparticle motion were investigated. Increasing the bulk ionic concentration or the surface charge of the nanochannel will increase the electroosmotic flow, and hence affect the particle’s motion. It was also shown that, unlike microchannels with thin EDL, the change in nanochannel size will change the EDL field and the ionic concentration field in the nanochannel, affecting the particle’s motion. If the nanochannel size is fixed, a larger particle will move faster than a smaller particle under the same conditions.

Electrokinetic properties of tantalum oxide deposited on model substrate in NaCl and LiCl solutions

International Nuclear Information System (INIS)

Sidorova, M.P.; Bogdanova, N.F.; Ermakova, L.Eh.; Bobrov, P.V.

1997-01-01

Electrokinetic characteristics of tantalum oxide have been studied using a model system - a plane-parallel capillary in chloride solutions containing monocharge (H + , Na + , Li + ) counterions in a wide range of pH and concentrations. It is shown that position of isoelectric point (IEP) of Ta 2 O 5 depends on concentration and type of counterion, moreover, the dependence is not explained in the framework of classical notions of the influence of counterion specific adsorption on IEP position. Electrokinetic potential of Ta 2 O-5 surface at the background of diluted LiCl solutions is higher in its absolute value, than at the background of NaCl solutions according to direct lyotropic series. The results of measurements of the capillary resistance dependence on pH at the background of NaCl and LiCl solutions 10 -3 -10 -1 M are used for the calculation of efficiency and specific surface conductivity factors

AC – AC Converters for UPS

Directory of Open Access Journals (Sweden)

Rusalin Lucian R. Păun

2008-05-01

Full Text Available This paper propose a new control technique forsingle – phase AC – AC converters used for a on-line UPSwith a good dynamic response, a reduced-partscomponents, a good output characteristic, a good powerfactorcorrection(PFC. This converter no needs anisolation transformer. A power factor correction rectifierand an inverter with the proposed control scheme has beendesigned and simulated using Caspoc2007, validating theconcept.

Commercialization of PV-powered pumping systems for use in utility PV service programs. Final report

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-03-01

The project described in this report was a commercialization effort focused on cost-effective remote water pumping systems for use in utility-based photovoltaic (PV) service programs. The project combined a commercialization strategy tailored specifically for electric utilities with the development of a PV-powered pumping system that operates conventional ac pumps rather than relying on the more expensive and less reliable PV pumps on the market. By combining these two attributes, a project goal was established of creating sustained utility purchases of 250 PV-powered water pumping systems per year. The results of each of these tasks are presented in two parts contained in this Final Summary Report. The first part summarizes the results of the Photovoltaic Services Network (PSN) as a new business venture, while the second part summarizes the results of the Golden Photon system installations. Specifically, results and photographs from each of the system installations are presented in this latter part.

Performance of AC/graphite capacitors at high weight ratios of AC/graphite

Energy Technology Data Exchange (ETDEWEB)

Wang, Hongyu [IM and T Ltd., Advanced Research Center, Saga University, 1341 Yoga-machi, Saga 840-0047 (Japan); Yoshio, Masaki [Advanced Research Center, Department of Applied Chemistry, Saga University, 1341 Yoga-machi, Saga 840-0047 (Japan)

2008-03-01

The effect of negative to positive electrode materials' weight ratio on the electrochemical performance of both activated carbon (AC)/AC and AC/graphite capacitors has been investigated, especially in the terms of capacity and cycle-ability. The limited capacity charge mode has been proposed to improve the cycle performance of AC/graphite capacitors at high weight ratios of AC/graphite. (author)

Pumps and pump facilities. 2. ed.

International Nuclear Information System (INIS)

Bohl, W.; Bauerfeind, H.; Gutmann, G.; Leuschner, G.; Matthias, H.B.; Mengele, R.; Neumaier, R.; Vetter, G.; Wagner, W.

1981-01-01

This book deals with the common fundamental aspects of liquid pumps and gives an exemplary choice of the most important kinds of pumps. The scientific matter is dealt with by means of practical mathematical examples among other ways of presenting the matter. Survey of contents: Division on main operational data of pumps - pipe characteristics - pump characteristics - suction behaviour of the pumps - projecting and operation of rotary pumps - boiler feed pumps - reactor feed pumps - oscillating positive-displacement pumps - eccentric spiral pumps. (orig./GL) [de

Singular deposit formation in PWR due to electrokinetic phenomena - application to SG clogging

Energy Technology Data Exchange (ETDEWEB)

Guillodo, M.; Muller, T.; Barale, M.; Foucault, M. [AREVA NP SAS, Technical Centre (France); Clinard, M.-H.; Brun, C.; Chahma, F. [AREVA NP SAS, Chemistry and Radiochemistry Group (France); Corredera, G.; De Bouvier, O. [Electricite de France, Centre d' Expertise de I' inspection dans les domaines de la Realisation et de l' Exploitation (France)

2009-07-01

The deposits which cause clogging of the 'foils' of the tube support plates (TSP) in Steam Generators (SG) of PWR present two characteristics which put forward that the mechanism at the origin of their formation is different from the mechanism that drives the formation of homogeneous deposits leading to the fouling of the free spans of SG tubes. Clogging occurs near the leading edge of the TSP and the deposits appear as diaphragms localized between both TSP and SG tubing materials, while the major part of the tube/TSP interstice presents little or no significant clogging. This type of deposit seems rather comparable to the ones which were reproduced in Lab tests to explain the flow rate instabilities observed on a French unit during hot shutdown in the 90's. The deposits which cause TSP clogging are owed to a discontinuity of the streaming currents in the vicinity of a surface singularity (orifices, scratches ...) which, in very low conductivity environment, produce local potential variations and/or current loop in the metallic pipe material due to electrokinetic effects. Deposits can be built by two mechanisms which may or not coexist: (i) accumulation of particles stabilized by an electrostatic attraction due to the local variation of electrokinetic potential, and (ii) crystalline growth of magnetite produced by the oxidation of ferrous ions on the anodic branch of a current loop. Lab investigations carried out by AREVA NP Technical Centre since the end of the 90's showed that this type of deposit occurs when the redox potential is higher than a critical value, and can be gradually dissolved when the potential becomes lower than this value which depends on the 'Material - Chemistry' couple. Special emphasis will be given in this paper to the TSP clogging of SG in PWR secondary coolant dealing particularly with the potential strong effect of electrokinetic phenomena in low conductive environment and in high temperature conditions

Electrokinetic Hydrogen Generation from Liquid WaterMicrojets

Energy Technology Data Exchange (ETDEWEB)

Duffin, Andrew M.; Saykally, Richard J.

2007-05-31

We describe a method for generating molecular hydrogen directly from the charge separation effected via rapid flow of liquid water through a metal orifice, wherein the input energy is the hydrostatic pressure times the volume flow rate. Both electrokinetic currents and hydrogen production rates are shown to follow simple equations derived from the overlap of the fluid velocity gradient and the anisotropic charge distribution resulting from selective adsorption of hydroxide ions to the nozzle surface. Pressure-driven fluid flow shears away the charge balancing hydronium ions from the diffuse double layer and carries them out of the aperture. Downstream neutralization of the excess protons at a grounded target electrode produces gaseous hydrogen molecules. The hydrogen production efficiency is currently very low (ca. 10-6) for a single cylindrical jet, but can be improved with design changes.

Precipitation-filtering technology for uranium waste solution generated on washing-electrokinetic decontamination

Energy Technology Data Exchange (ETDEWEB)

Kim, Gye-Nam, E-mail: kimsum@kaeri.re.kr; Park, Uk-Ryang; Kim, Seung-Soo; Moon, Jei-Kwon

2015-05-15

Graphical abstract: A recycling process diagram for the volume reduction of waste solution generated from washing-electrokinetic decontamination. - Highlights: • A process for recycling a waste solution generated was developed. • The total metal precipitation rate by NaOH in a supernatant after precipitation was the highest at pH 9. • The uranium radioactivity in the treated solution upon injection of 0.2 g of alum was lower. • After drying, the volume of sludge was reduced to 35% of the initial sludge volume. - Abstract: Large volumes of uranium waste solution are generated during the operation of washing-electrokinetic decontamination equipment used to remove uranium from radioactive soil. A treatment technology for uranium waste solution generated upon washing-electrokinetic decontamination for soil contaminated with uranium has been developed. The results of laboratory-size precipitation experiments were as follows. The total amount of metal precipitation by NaOH for waste solution was highest at pH 11. Ca(II), K(I), and Al(III) ions in the supernatant partially remained after precipitation, whereas the concentration of uranium in the supernatant was below 0.2 ppm. Also, when NaOH was used as a precipitant, the majority of the K(I) ions in the treated solution remained. The problem of CaO is to need a long dissolution time in the precipitation tank, while Ca(OH){sub 2} can save a dissolution time. However, the volume of the waste solution generated when using Ca(OH){sub 2} increased by 8 mL/100 mL (waste solution) compared to that generated when using CaO. NaOH precipitant required lower an injection volume lower than that required for Ca(OH){sub 2} or CaO. When CaO was used as a precipitant, the uranium radioactivity in the treated solution at pH 11 reached its lowest value, compared to values of uranium radioactivity at pH 9 and pH 5. Also, the uranium radioactivity in the treated solution upon injection of 0.2 g of alum with CaO or Ca(OH){sub 2} was

The role of capacitance in a wind-electric water pumping system

Energy Technology Data Exchange (ETDEWEB)

Ling, Shitao [West Texas A& M Univ., Canyon, TX (United States); Clark, R.N. [Conservation and Production Research Lab., Bushland, TX (United States)

1997-12-31

The development of controllers for wind-electric water pumping systems to enable the use of variable voltage, variable frequency electricity to operate standard AC submersible pump motors has provided a more efficient and flexible water pumping system to replace mechanical windmills. A fixed capacitance added in parallel with the induction motor improves the power factor and starting ability of the pump motor at the lower cut-in frequency. The wind-electric water pumping system developed by USDA-Agricultural Research Service, Bushland, TX, operated well at moderate wind speeds (5-12 m/s), but tended to lose synchronization in winds above 12 m/s, especially if they were gusty. Furling generally did not occur until synchronization had been lost and the winds had to subside before synchronization could be reestablished. The frequency needed to reestablish synchronization was much lower (60-65 Hz) than the frequency where synchronization was lost (70-80 Hz). As a result, the load (motor and pump) stayed off an excessive amount of time thus causing less water to be pumped and producing a low system efficiency. The controller described in this paper dynamically connects additional capacitance of the proper amount at the appropriate time to keep the system synchronized (running at 55 to 60 Hz) and pumping water even when the wind speed exceeds 15 m/s. The system efficiency was improved by reducing the system off-line time and an additional benefit was reducing the noise caused by the high speed blade rotation when the load was off line in high winds.

Insights into head-column field-amplified sample stacking: Part II. Study of the behavior of the electrophoretic system after electrokinetic injection of cationic compounds across a short water plug.

Science.gov (United States)

Šesták, Jozef; Thormann, Wolfgang

2017-08-25

Part I on head-column field-amplified sample stacking comprised a detailed study of the electrokinetic injection of a weak base across a short water plug into a phosphate buffer at low pH. The water plug is converted into a low conductive acidic zone and cationic analytes become stacked at the interface between this and a newly formed phosphoric acid zone. The fundamentals of electrokinetic processes occurring thereafter were studied experimentally and with computer simulation and are presented as part II. The configuration analyzed represents a discontinuous buffer system. Computer simulation revealed that the phosphoric acid zone at the plug-buffer interface becomes converted into a migrating phosphate buffer plug which corresponds to the cationically migrating system zone of the phosphate buffer system. Its mobility is higher than that of the analytes such that they migrate behind the system zone in a phosphate buffer comparable to the applied background electrolyte. The temporal behaviour of the current and the conductivity across the water plug were monitored and found to reflect the changes in the low conductivity plug. Determination of the buffer flow in the capillary revealed increased pumping caused by the mismatch of electroosmosis within the low conductivity plug and the buffer. This effect becomes elevated with increasing water plug length. For plug lengths up to 1% of the total column length the flow quickly drops to the electroosmotic flow of the buffer and simulations with experimentally determined current and flow values predict negligible band dispersion and no loss of resolution for both low and large molecular mass components. Copyright © 2017 Elsevier B.V. All rights reserved.

The Use of Electrical Resistivity Method to Mapping The Migration of Heavy Metals by Electrokinetic

Science.gov (United States)

Azhar, A. T. S.; Ayuni, S. A.; Ezree, A. M.; Nizam, Z. M.; Aziman, M.; Hazreek, Z. A. M.; Norshuhaila, M. S.; Zaidi, E.

2017-08-01

The presence of heavy metals contamination in soil environment highly needs innovative remediation. Basically, this contamination was resulted from ex-mining sites, motor workshop, petrol station, landfill and industrial sites. Therefore, soil treatment is very important due to metal ions are characterized as non-biodegradable material that may be harmful to ecological system, food chain, human health and groundwater sources. There are various techniques that have been proposed to eliminate the heavy metal contamination from the soil such as bioremediation, phytoremediation, electrokinetic remediation, solidification and stabilization. The selection of treatment needs to fulfill some criteria such as cost-effective, easy to apply, green approach and high remediation efficiency. Electrokinetic remediation technique (EKR) offers those solutions in certain area where other methods are impractical. While, electrical resistivity method offers an alternative geophysical technique for soil subsurface profiling to mapping the heavy metals migration by the influece of electrical gradient. Consequently, this paper presents an overview of the use of EKR to treat contaminated soil by using ERM method to verify their effectiveness to remove heavy metals.

Quantum spin and charge pumping through double quantum dots with ferromagnetic leads

Energy Technology Data Exchange (ETDEWEB)

Pan, Hui, E-mail: hpan@buaa.edu.cn [Department of Physics, Beijing University of Aeronautics and Astronautics, Beijing 100191 (China); Key Laboratory of Micro-Nano Measurement-Manipulation and Physics (Ministry of Education), Beihang University, Beijing 100191 (China); Chen, Ziyu; Zhao, Sufen [Department of Physics, Beijing University of Aeronautics and Astronautics, Beijing 100191 (China); Lue, Rong [Department of Physics, Tsinghua University, Beijing 100084 (China)

2011-06-06

The pumping of electrons through double quantum dots (DQDs) attached to ferromagnetic leads have been theoretically investigated by using the nonequilibrium Green's function method. It is found that an oscillating electric field applied to the quantum dot may give rise to the pumped charge and spin currents. In the case that both leads are ferromagnet, a pure spin current can be generated in the antiparallel magnetization configuration, where no net charge current exists. The possibility of manipulating the pumped spin current is explored by tuning the dot level and the ac field. By making use of various tunings, the magnitude and direction of the pumped spin current can be well controlled. For the case that only one lead is ferromagnetic, both of the charge and spin currents can be pumped and flow in opposite directions on the average. The control of the magnitude and direction of the pumped charge and spin currents is also discussed by means of the magnetic flux threading through the DQD ring. -- Highlights: → We theoretically investigate the pumping of electrons through double quantum dots attached to ferromagnetic leads. → An oscillating electric field applied to the quantum dot may give rise to the pumped charge and spin currents. → When both leads are ferromagnet, a pure spin current can be generated in the antiparallel magnetization configuration. → By making use of various tunings, the magnitude and direction of the pumped spin current can be well controlled. → When only one lead is ferromagnetic, both of the charge and spin currents can be pumped and flow in opposite directions.

Electrokinetic mobilisation of toluene and chlorinated ethenes in low permeable soils

Energy Technology Data Exchange (ETDEWEB)

Middeldorp, P.; Sinke, A. [TNO Environment Energy and Process Innovation, Apeldoorn (Netherlands)

2001-07-01

An electrokinetic horizontal soil column setup was developed to study the effect of electric current on the mobilisation and biodegradation of organic pollutants in soil. Toluene and tetrachloroethene (PCE) were injected between the two electrodes in the center of the soil column and a DC current of 1 V/cm was applied. We observed a breakthrough of PCE and toluene at the cathode side after 8 days and 11 days respectively. This short experiment shows the possibility to enhance the mobility of non-ionic organic pollutants through electro-osmosis. (orig.)

Electro-kinetic remediation coupled with phytoremediation to remove lead, arsenic and cesium from contaminated paddy soil.

Science.gov (United States)

Mao, Xinyu; Han, Fengxiang X; Shao, Xiaohou; Guo, Kai; McComb, Jacqueline; Arslan, Zikri; Zhang, Zhanyu

2016-03-01

The objectives of this study were to investigate distribution and solubility of Pb, Cs and As in soils under electrokinetic field and examine the processes of coupled electrokinetic phytoremediation of polluted soils. The elevated bioavailability and bioaccumulation of Pb, As and Cs in paddy soil under an electro-kinetic field (EKF) were studied. The results show that the EKF treatment is effective on lowering soil pH to around 1.5 near the anode which is beneficial for the dissolution of metal(loid)s, thus increasing their overall solubility. The acidification in the anode soil efficiently increased the water soluble (SOL) and exchangeable (EXC) Pb, As and Cs, implying enhanced solubility and elevated overall potential bioavailability in the anode region while lower solubility in the cathode areas. Bioaccumulations of Pb, As and Cs were largely determined by the nature of elements, loading levels and EKF treatment. The native Pb in soil usually is not bioavailable. However, EKF treatment tends to transfer Pb to the SOL and EXC fractions improving the phytoextraction efficiency. Similarly, EKF transferred more EXC As and Cs to the SOL fraction significantly increasing their bioaccumulation in plant roots and shoots. Pb and As were accumulated more in plant roots than in shoots while Cs was accumulated more in shoots due to its similarity of chemical properties to potassium. Indian mustard, spinach and cabbage are good accumulators for Cs. Translocation of Pb, As and Cs from plant roots to shoots were enhanced by EKF. However, this study indicated the overall low phytoextraction efficiency of these plants. Copyright © 2015 Elsevier Inc. All rights reserved.

Phosphorus recovery from sewage sludge by an electrokinetic process

DEFF Research Database (Denmark)

Ribeiro, A.B.; Couto, N.; Mateus, E.P.

to supply P for the next ca. 80 years. Additionaly, the quality of this raw material has deteriorated due to contamination, which has increased processing costs of mineral P fertilizers. The recovery of nutrients, like P, from secondary resources urges. Sewage sludge (SS) and sewage sludge ash (SSA) from...... waste water treatment plants (WWTP) may contain contaminants or unwanted elements regarding specific applications, but they also contain secondary resources of high value. Using these ash as a P resource, while removing the contaminants, seems a sustainable option. The electrokinetic (EK) process can....... This communication aims to discuss preliminary results of the feasibility of EK process to recover P from WWTP target wastes....

Superhydrophobic nanofluidic channels for enhanced electrokinetic conversion

Science.gov (United States)

Checco, Antonio; Al Hossain, Aktaruzzaman; Rahmani, Amir; Black, Charles; Doerk, Gregory; Colosqui, Carlos

2017-11-01

We present current efforts in the development of novel slit nanofluidic channels with superhydrophobic nanostructured surfaces designed to enhance hydrodynamic conductivity and improve selective transport and electrokinetic energy conversion efficiencies (mechanical-electrical energy conversion). The nanochannels are fabricated on silicon wafers using UV lithography, and their internal surface is patterned with conical nanostructures (feature size and spacing 30 nm) defined by block copolymer self-assembly and plasma etching. These nanostructures are rendered superhydrophobic by passivation with a hydrophobic silane monolayer. We experimentally characterize hydrodynamic conductivity, effective zeta potentials, and eletrokinetic flows for the patterned nanochannels, comparing against control channels with bare surfaces. Experimental observations are rationalized using both continuum-based modeling and molecular dynamics simulations. Scientific and technical knowledge produced by this work is particularly relevant for sustainable energy conversion and storage, separation processes and water treatment using nanoporous materials. The ONR Contract # N000141613178 and NSF-CBET award# 1605809.

Synergistic effects of bioremediation and electrokinetics in the remediation of petroleum-contaminated soil.

Science.gov (United States)

Guo, Shuhai; Fan, Ruijuan; Li, Tingting; Hartog, Niels; Li, Fengmei; Yang, Xuelian

2014-08-01

The present study evaluated the coupling interactions between bioremediation (BIO) and electrokinetics (EK) in the remediation of total petroleum hydrocarbons (TPH) by using bio-electrokinetics (BIO-EK) with a rotatory 2-D electric field. The results demonstrated an obvious positive correlation between the degradation extents of TPH and electric intensity both in the EK and BIO-EK tests. The use of BIO-EK showed a significant improvement in degradation of TPH as compared to BIO or EK alone. The actual degradation curve in BIO-EK tests fitted well with the simulated curve obtained by combining the degradation curves in BIO- and EK-only tests during the first 60 d, indicating a superimposed effect of biological degradation and electrochemical stimulation. The synergistic effect was particularly expressed during the later phase of the experiment, concurrent with changes in the microbial community structure. The community composition changed mainly according to the duration of the electric field, leading to a reduction in diversity. No significant spatial shifts in microbial community composition and bacterial numbers were detected among different sampling positions. Soil pH was uniform during the experimental process, soil temperature showed no variations between the soil chambers with and without an electric field. Copyright © 2014 Elsevier Ltd. All rights reserved.

Dual-pump CARS measurements in a hydrogen diffusion flame in cross-flow with AC dielectric barrier discharge

Science.gov (United States)

Nishihara, Munetake; Freund, Jonathan B.; Glumac, Nick G.; Elliott, Gregory S.

2018-03-01

This paper presents dual-pump coherent anti-Stokes Raman scattering (CARS) measurements for simultaneous detection of flow temperature and relative concentration, applied to the characterization of a discharge-coupled reacting jet in a cross flow. The diagnostic is hydrogen Q-branch based, providing a much wider dynamic range compared to detection in the S-branch. For a previously developed dielectric barrier discharge, aligned co-axially with the fuel jet, OH planar laser induced fluorescence measurements show that the disturbance in the flame boundary leads to mixing enhancement. The H2-N2 dual-pump CARS measurement was used to map two-dimensional temperature distributions. The increase of the maximum temperature was up to 300 K, with 50% more H2 consumption, providing the reason for the decrease in the flame length by 25%. The increase of the relative H2O-H2 fraction was accompanied with a temperature increase, which indicates local equivalence ratios of below 1. The H2-O2 dual-pump measurements confirmed that the fuel-oxidizer ratios remain in the fuel-lean side at most of the probed locations.

Reactor coolant pump shaft seal stability during station blackout

International Nuclear Information System (INIS)

Rhodes, D.B.; Hill, R.C.; Wensel, R.G.

1987-05-01

Results are presented from an investigation into the behavior of Reactor Coolant Pump shaft seals during a potential station blackout (loss of all ac power) at a nuclear power plant. The investigation assumes loss of cooling to the seals and focuses on the effect of high temperature on polymer seals located in the shaft seal assemblies, and the identification of parameters having the most influence on overall hydraulic seal performance. Predicted seal failure thresholds are presented for a range of station blackout conditions and shaft seal geometries

Reactor coolant pump shaft seal stability during station blackout

Energy Technology Data Exchange (ETDEWEB)

Rhodes, D B; Hill, R C; Wensel, R G

1987-05-01

Results are presented from an investigation into the behavior of Reactor Coolant Pump shaft seals during a potential station blackout (loss of all ac power) at a nuclear power plant. The investigation assumes loss of cooling to the seals and focuses on the effect of high temperature on polymer seals located in the shaft seal assemblies, and the identification of parameters having the most influence on overall hydraulic seal performance. Predicted seal failure thresholds are presented for a range of station blackout conditions and shaft seal geometries.

Modeling of electrokinetic processes by finite element integration of the Nernst–Planck–Poisson system of equations

DEFF Research Database (Denmark)

Paz-Garcia, Juan Manuel; Johannesson, Björn; Ottosen, Lisbeth M.

2011-01-01

equilibrium is continuously assured and the pH value is monitored. Results from some selected test simulations of the electrokinetic desalination of a sample of porous material are presented, outlining the versatility of the model as well as showing the effect of the counterion in the removal rate of a target...

Influence of the ac Stark effect on stimulated hyper-Raman profiles in sodium vapor

International Nuclear Information System (INIS)

Moore, M.A.; Garrett, W.R.; Payne, M.G.

1988-08-01

When pumping near the two-photon 3d resonance in pure sodium vapor and observing the backward hyper-Raman emission to the 3p substates, an asymmetry in ratios of 3p/sub 1/2/, 3p/sub 3/2/ associated emissions was observed dependent upon the direction of the initial laser detuning from the resonance. It has been determined that this asymmetry can be attributed to the ac Stark effect induced by the hyper-Raman emission itself. 3 refs., 3 figs

Electrokinetic investigations on the system polystyrene/aqueous electrolyte solution : verification of model theories on dilute and concentrated dispersions

NARCIS (Netherlands)

Put, van der A.G.

1980-01-01

This thesis presents a systematic experimental and theoretical study on electrokinetic and electroconducting properties of disperse systems. The increasing interest in transport processes through charged porous systems has recently brought about a corresponding growth of models and theories since

A multiscale theoretical investigation of electric measurements in living bone : piezoelectricity and electrokinetics.

Science.gov (United States)

Lemaire, T; Capiez-Lernout, E; Kaiser, J; Naili, S; Rohan, E; Sansalone, V

2011-11-01

This paper presents a theoretical investigation of the multiphysical phenomena that govern cortical bone behaviour. Taking into account the piezoelectricity of the collagen-apatite matrix and the electrokinetics governing the interstitial fluid movement, we adopt a multiscale approach to derive a coupled poroelastic model of cortical tissue. Following how the phenomena propagate from the microscale to the tissue scale, we are able to determine the nature of macroscopically observed electric phenomena in bone.

Pumping behavior of sputter ion pumps

International Nuclear Information System (INIS)

Chou, T.S.; McCafferty, D.

The ultrahigh vacuum requirements of ISABELLE is obtained by distributed pumping stations. Each pumping station consists of 1000 l/s titanium sublimation pump for active gases (N 2 , H 2 , O 2 , CO, etc.), and a 20 l/s sputter ion pump for inert gases (methane, noble gases like He, etc.). The combination of the alarming production rate of methane from titanium sublimation pumps (TSP) and the decreasing pumping speed of sputter ion pumps (SIP) in the ultrahigh vacuum region (UHV) leads us to investigate this problem. In this paper, we first describe the essential physics and chemistry of the SIP in a very clean condition, followed by a discussion of our measuring techniques. Finally measured methane, argon and helium pumping speeds are presented for three different ion pumps in the range of 10 -6 to 10 -11 Torr. The virtues of the best pump are also discussed

Ground-source heat pump barometer

International Nuclear Information System (INIS)

Anon.

2011-01-01

In Europe the ground-source heat pump market contracted for the second year running by 2.9% between 2009 and 2010. Around 103.000 units were sold in 2010, taking the number of installed units over one million. The 3 European countries with the most sales are Sweden (31953 units, +16%), Germany (25516 units, -13%) and France (12250 units, -21%). The drop in sales is generally due to market contraction on the current recession but some specificities exist: for instance the insufficient training of the installers has led to under-performance and to a bad image of this energy in France. The Swedish and German manufacturers are in a very strong position and are increasing their market share in the main European markets. (A.C.)

Theoretical and experimental analysis of the behaviour of a photovoltaic pumping system

Energy Technology Data Exchange (ETDEWEB)

Hamrouni, Nejib; Jraidi, Moncef; Cherif, Adnene [High Engineering Faculty of Tunis PB 37, Belvedere, Tunis (Tunisia)

2009-08-15

The aim of the paper is to present the influence of the solar radiation variation on the performances of a stand alone photovoltaic pumping system which consists of photovoltaic generator, dc-dc converter, dc-ac inverter, an immersed group motor-pump and a storage tank that serves a similar purpose to battery storage. Hence a theoretical analysis (modelling and control) of the system is needed. Attention has been paid to the command of the power converters using MPPT and variable V/f laws. The MPPT control allows the extraction of the maximal output power delivered by the PV generator. The inverter ensures the PWM control of the asynchronous motor and a sine wave form of output signals. From the obtained simulation results, we will show that the decrease of the solar radiation degrades performances (the global efficiency and the flow rate) of the PV pumping system. The analysis is validated by simulation and experimental results. (author)

Solid/solution Cu fractionations/speciation of a Cu contaminated soil after pilot-scale electrokinetic remediation and their relationships with soil microbial and enzyme activities

International Nuclear Information System (INIS)

Wang Quanying; Zhou Dongmei; Cang Long; Li Lianzhen; Wang Peng

2009-01-01

The aim of this study was to investigate the detailed metal speciation/fractionations of a Cu contaminated soil before and after electrokinetic remediation as well as their relationships with the soil microbial and enzyme activities. Significant changes in the exchangeable and adsorbed-Cu fractionations occurred after electrokinetic treatment, while labile soil Cu in the solution had a tendency to decrease from the anode to the cathode, and the soil free Cu 2+ ions were mainly accumulated in the sections close to the cathode. The results of regression analyses revealed that both the soil Cu speciation in solution phase and the Cu fractionations in solid phase could play important roles in the changes of the soil microbial and enzyme activities. Our findings suggest that the bioavailability of soil heavy metals and their ecotoxicological effects on the soil biota before and after electroremediation can be better understood in terms of their chemical speciation and fractionations. - The assessment of the roles of soil solution speciation and solid-phase fractionations in metal bioavailability after electrokinetic remediation deserves close attention.

Electromagnetically powered electrolytic pump and thermo-responsive valve for drug delivery

KAUST Repository

Yi, Ying; Zaher, Amir; Yassine, Omar; Buttner, Ulrich; Kosel, Jü rgen; Foulds, Ian G.

2015-01-01

A novel drug delivery device is presented, implementing an electrolytic pump and a thermo-responsive valve. The device is remotely operated by an AC electromagnetic field (40.5∼58.5 mT, 450 kHz) that provides the power for the pump and the valve. It is suitable for long-term therapy applications, which use a solid drug in reservoir (SDR) approach and avoids unwanted drug diffusion. When the electromagnetic field is on, the electrolytic pump drives the drug towards the valve. The valve is made of a magnetic composite consisting of a smart hydrogel: Poly (N-Isopropylacrylamide) (PNIPAm) and iron powder. The heat generated in the iron powder via magnetic losses causes the PNIPAm to shrink, allowing the drug to flow past it. When the electromagnetic field is off, the PNIPAm swells, sealing the outlet. In the meantime, the bubbles generated by electrolysis recombine into water, causing a pressure reduction in the pumping chamber. This draws fresh fluid from outside the pump into the drug reservoir before the valve is fully sealed. The recombination can be accelerated by a platinum (Pt) coated catalytic reformer, allowing more fluid to flow back to the drug reservoir and dissolve the drug. By repeatedly turning on and off the magnetic field, the drug solution can be delivered cyclically. © 2015 IEEE.

Electromagnetically powered electrolytic pump and thermo-responsive valve for drug delivery

KAUST Repository

Yi, Ying

2015-04-01

A novel drug delivery device is presented, implementing an electrolytic pump and a thermo-responsive valve. The device is remotely operated by an AC electromagnetic field (40.5∼58.5 mT, 450 kHz) that provides the power for the pump and the valve. It is suitable for long-term therapy applications, which use a solid drug in reservoir (SDR) approach and avoids unwanted drug diffusion. When the electromagnetic field is on, the electrolytic pump drives the drug towards the valve. The valve is made of a magnetic composite consisting of a smart hydrogel: Poly (N-Isopropylacrylamide) (PNIPAm) and iron powder. The heat generated in the iron powder via magnetic losses causes the PNIPAm to shrink, allowing the drug to flow past it. When the electromagnetic field is off, the PNIPAm swells, sealing the outlet. In the meantime, the bubbles generated by electrolysis recombine into water, causing a pressure reduction in the pumping chamber. This draws fresh fluid from outside the pump into the drug reservoir before the valve is fully sealed. The recombination can be accelerated by a platinum (Pt) coated catalytic reformer, allowing more fluid to flow back to the drug reservoir and dissolve the drug. By repeatedly turning on and off the magnetic field, the drug solution can be delivered cyclically. © 2015 IEEE.

Peltier ac calorimeter

OpenAIRE

Jung, D. H.; Moon, I. K.; Jeong, Y. H.

2001-01-01

A new ac calorimeter, utilizing the Peltier effect of a thermocouple junction as an ac power source, is described. This Peltier ac calorimeter allows to measure the absolute value of heat capacity of small solid samples with sub-milligrams of mass. The calorimeter can also be used as a dynamic one with a dynamic range of several decades at low frequencies.

Electrokinetics of diffuse soft interfaces. 1. Limit of low Donnan potentials.

Science.gov (United States)

Duval, Jérôme F L; van Leeuwen, Herman P

2004-11-09

The current theoretical approaches to electrokinetics of gels or polyelectrolyte layers are based on the assumption that the position of the very interface between the aqueous medium and the gel phase is well defined. Within this assumption, spatial profiles for the volume fraction of polymer segments (phi), the density of fixed charges in the porous layer (rho fix), and the coefficient modeling the friction to hydrodynamic flow (k) follow a step-function. In reality, the "fuzzy" nature of the charged soft layer is intrinsically incompatible with the concept of a sharp interface and therefore necessarily calls for more detailed spatial representations for phi, rho fix, and k. In this paper, the notion of diffuse interface is introduced. For the sake of illustration, linear spatial distributions for phi and rho fix are considered in the interfacial zone between the bulk of the porous charged layer and the bulk electrolyte solution. The corresponding distribution for k is inferred from the Brinkman equation, which for low phi reduces to Stokes' equation. Linear electrostatics, hydrodynamics, and electroosmosis issues are analytically solved within the context of streaming current and streaming potential of charged surface layers in a thin-layer cell. The hydrodynamic analysis clearly demonstrates the physical incorrectness of the concept of a discrete slip plane for diffuse interfaces. For moderate to low electrolyte concentrations and nanoscale spatial transition of phi from zero (bulk electrolyte) to phi o (bulk gel), the electrokinetic properties of the soft layer as predicted by the theory considerably deviate from those calculated on the basis of the discontinuous approximation by Ohshima.

Energy performance and consumption for biogas heat pump air conditioner

Energy Technology Data Exchange (ETDEWEB)

Xu, Zhenjun [Architectural Engineering College, Qingdao Agricultural University, 266109 (China); Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101 (China); Tianjin University, Tianjin, 300072 (China); Wu, Huaizhi; Wu, Meiling [Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101 (China); Tianjin University, Tianjin, 300072 (China)

2010-12-15

Biogas engine-driven heat pump air conditioner is a new-style system which includes biogas engine-driven heat pump, primary heat exchanger, second heat exchanger, sprayed room and fans, pumps, etc. In summertime, the air can be reheated by the waste heat water from the biogas engine in the system, while the air can be reheated and humidified by the waste heat water in winter. Reducing or displacing electrical heating requirements can achieve the great opportunity for significant energy savings. This paper, therefore, aims to improve the energy performance of the AC system by using the waste heat from the biogas engine. The mathematic model was used to research the BHPAC. Explicitly, we investigated the influence of various factors including the outdoor air temperature and humidity in summer and winter. Results show that the biogas engine-driven heat pump air conditioner can save more energy than the electrical power heat pump. In summer, the minimum for percentage of primary energy saving for BHPAC is over 25%. With the outdoor air dry-bulb temperature and the relative humidity rises, the saving energy percentage rises. In winter, the minimum for percentage of primary energy saving for BHPAC is 37%. The more the outdoor air relative humidity of the outdoor air decreases, the more the BHPAC saves energy. It is proved that the system which is a highly actively fully utilizing energy technology has good partial load characteristic and good effects of energy saving. (author)

Digital model for harmonic interactions in AC/DC/AC systems

Energy Technology Data Exchange (ETDEWEB)

Guarini, A P; Rangel, R D; Pilotto, L A.S.; Pinto, R J; Passos, Junior, R [Centro de Pesquisas de Energia Eletrica (CEPEL), Rio de Janeiro, RJ (Brazil)

1994-12-31

The main purpose of this paper is to present a model for calculation of HVdc converter harmonics taking into account the influence of the harmonic interactions between the ac systems in dc link transmissions. The ideas and methodologies used in the model development take into account the dc current ripple and ac voltage distortion in the ac systems. The theory of switching functions is applied to contemplate for the frequency conversions between the ac and dc sides, in an iterative process. It is possible then to obtain, even in balanced situations, non-characteristic harmonics that are produced by frequencies originated in the other terminal, which can be significant in a strongly coupled system, such as back-to-back configuration. (author) 9 refs., 3 figs.

On-chip high-voltage generator design design methodology for charge pumps

CERN Document Server

Tanzawa, Toru

2016-01-01

This book provides various design techniques for switched-capacitor on-chip high-voltage generators, including charge pump circuits, regulators, level shifters, references, and oscillators.  Readers will see these techniques applied to system design in order to address the challenge of how the on-chip high-voltage generator is designed for Flash memories, LCD drivers, and other semiconductor devices to optimize the entire circuit area and power efficiency with a low voltage supply, while minimizing the cost.  This new edition includes a variety of useful updates, including coverage of power efficiency and comprehensive optimization methodologies for DC-DC voltage multipliers, modeling of extremely low voltage Dickson charge pumps, and modeling and optimum design of AC-DC switched-capacitor multipliers for energy harvesting and power transfer for RFID.

Sub-Grid Modeling of Electrokinetic Effects in Micro Flows

Science.gov (United States)

Chen, C. P.

2005-01-01

Advances in micro-fabrication processes have generated tremendous interests in miniaturizing chemical and biomedical analyses into integrated microsystems (Lab-on-Chip devices). To successfully design and operate the micro fluidics system, it is essential to understand the fundamental fluid flow phenomena when channel sizes are shrink to micron or even nano dimensions. One important phenomenon is the electro kinetic effect in micro/nano channels due to the existence of the electrical double layer (EDL) near a solid-liquid interface. Not only EDL is responsible for electro-osmosis pumping when an electric field parallel to the surface is imposed, EDL also causes extra flow resistance (the electro-viscous effect) and flow anomaly (such as early transition from laminar to turbulent flow) observed in pressure-driven microchannel flows. Modeling and simulation of electro-kinetic effects on micro flows poses significant numerical challenge due to the fact that the sizes of the double layer (10 nm up to microns) are very thin compared to channel width (can be up to 100 s of m). Since the typical thickness of the double layer is extremely small compared to the channel width, it would be computationally very costly to capture the velocity profile inside the double layer by placing sufficient number of grid cells in the layer to resolve the velocity changes, especially in complex, 3-d geometries. Existing approaches using "slip" wall velocity and augmented double layer are difficult to use when the flow geometry is complicated, e.g. flow in a T-junction, X-junction, etc. In order to overcome the difficulties arising from those two approaches, we have developed a sub-grid integration method to properly account for the physics of the double layer. The integration approach can be used on simple or complicated flow geometries. Resolution of the double layer is not needed in this approach, and the effects of the double layer can be accounted for at the same time. With this

Non-adiabatic pumping in an oscillating-piston model

Science.gov (United States)

Chuchem, Maya; Dittrich, Thomas; Cohen, Doron

2012-05-01

We consider the prototypical "piston pump" operating on a ring, where a circulating current is induced by means of an AC driving. This can be regarded as a generalized Fermi-Ulam model, incorporating a finite-height moving wall (piston) and non-trivial topology (ring). The amount of particles transported per cycle is determined by a layered structure of phase space. Each layer is characterized by a different drift velocity. We discuss the differences compared with the adiabatic and Boltzmann pictures, and highlight the significance of the "diabatic" contribution that might lead to a counter-stirring effect.

A multiphase electrokinetic flow model for electrolytes with liquid/liquid interfaces

Energy Technology Data Exchange (ETDEWEB)

Berry, J.D., E-mail: joe.d.berry@gmail.com; Davidson, M.R., E-mail: m.davidson@unimelb.edu.au; Harvie, D.J.E., E-mail: daltonh@unimelb.edu.au

2013-10-15

A numerical model for electrokinetic flow of multiphase systems with deformable interfaces is presented, based on a combined level set-volume of fluid technique. A new feature is a multiphase formulation of the Nernst–Planck transport equation for advection, diffusion and conduction of individual charge carrier species that ensures their conservation in each fluid phase. The numerical model is validated against the analytical results of Zholkovskij et al. (2002) [1], and results for the problem of two drops coalescing in the presence of mobile charge carriers are presented. The time taken for two drops containing ions to coalesce decreases with increasing ion concentration.

Study of high-pressure cryogenic pumps with different methods of delivery control

International Nuclear Information System (INIS)

Braun, V.M.; Brailovskii, Y.L.; Pavlenko, Y.A.; Tsokalo, I.V.

1986-01-01

This paper describes new reciprocating pumps with smooth control of delivery in a running pump. Control is effected either by changing the length of the piston stroke or by changing the speed of the driving motor. The individual features of the two methods are described. In the first method (mechanical), delivery is controlled in the range 50 to 100%. A separate actuating mechanism is needed to connect the pump to an automatic control system. This method complicates the driving mechanism and increases the bulk and cost of production. In the second method of controlling the speed of the electric motor, an electric drive fitted with a frequency thyristor is used. AC induction motors series 4A working at current frequencies of 60 HZ are used. By this method, delivery control could be enhanced by 1.3 times. Comparative tests were made on pumps using the above methods of control. The tests demonstrated the possibilities of using the frequency thyristor converters. The complexity and high cost of EKT type drives is largely compensated by the convenience and simplicity of control in a wide range. The mechanical control is advantageous only in low-output units

Monitoring and modelling of pumping-induced self-potentials for transmissivity estimation within a heterogeneous confined aquifer

Science.gov (United States)

DesRoches, Aaron J.; Butler, Karl E.

2016-12-01

Variations in self-potentials (SP) measured at surface during pumping of a heterogeneous confined fractured rock aquifer have been monitored and modelled in order to investigate capabilities and limitations of SP methods in estimating aquifer hydraulic properties. SP variations were recorded around a pumping well using an irregular grid of 31 non-polarizing Pb-PbCl2 that were referenced to a remote electrode and connected to a commercial multiplexer and digitizer/data logger through a passive lowpass filter on each channel. The lowpass filter reduced noise by a factor of 10 compared to levels obtained using the data logger's integration-based sampling method for powerline noise suppression alone. SP signals showed a linear relationship with water levels observed in the pumping and monitoring wells over the pumping period, with an apparent electrokinetic coupling coefficient of -3.4 mV · m-1. Following recent developments in SP methodology, variability of the SP response between different electrodes is taken as a proxy for lateral variations in hydraulic head within the aquifer and used to infer lateral variations in the aquifer's apparent transmissivity. In order to demonstrate the viability of this approach, SP is modelled numerically to determine its sensitivity to (i) lateral variations in the hydraulic conductivity of the confined aquifer and (ii) the electrical conductivity of the confining layer and conductive well casing. In all cases, SP simulated on the surface still varies linearly with hydraulic head modelled at the base on the confining layer although the apparent coupling coefficient changes to varying degrees. Using the linear relationship observed in the field, drawdown curves were inferred for each electrode location using SP variations observed over the duration of the pumping period. Transmissivity estimates, obtained by fitting the Theis model to inferred drawdown curves at all 31 electrodes, fell within a narrow range of (2.0-4.2) × 10-3 m2 �

Effects of surface roughness and electrokinetic heterogeneity on electroosmotic flow in microchannel

Energy Technology Data Exchange (ETDEWEB)

Masilamani, Kannan; Ganguly, Suvankar; Feichtinger, Christian; Bartuschat, Dominik; Rüde, Ulrich, E-mail: suva_112@yahoo.co.in [Department of Computer Science 10 University of Erlangen-Nuremberg, Cauerstr.11 91058 Erlangen (Germany)

2015-06-15

In this paper, a hybrid lattice-Boltzmann and finite-difference (LB-FD) model is applied to simulate the effects of three-dimensional surface roughness and electrokinetic heterogeneity on electroosmotic flow (EOF) in a microchannel. The lattice-Boltzmann (LB) method has been employed to obtain the flow field and a finite-difference (FD) method is used to solve the Poisson-Boltzmann (PB) equation for the electrostatic potential distribution. Numerical simulation of flow through a square cross-section microchannel with designed roughness is conducted and the results are critically analysed. The effects of surface heterogeneity on the electroosmotic transport are investigated for different roughness height, width, roughness interval spacing, and roughness surface potential. Numerical simulations reveal that the presence of surface roughness changes the nature of electroosmotic transport through the microchannel. It is found that the electroosmotic velocity decreases with the increase in roughness height and the velocity profile becomes asymmetric. For the same height of the roughness elements, the EOF velocity rises with the increase in roughness width. For the heterogeneously charged rough channel, the velocity profile shows a distinct deviation from the conventional plug-like flow pattern. The simulation results also indicate locally induced flow vortices which can be utilized to enhance the flow and mixing within the microchannel. The present study has important implications towards electrokinetic flow control in the microchannel, and can provide an efficient way to design a microfluidic system of practical interest. (paper)

Electrokinetic label-free screening chip: a marriage of multiplexing and high throughput analysis using surface plasmon resonance imaging

NARCIS (Netherlands)

Krishnamoorthy, G.; Carlen, Edwin; Bomer, Johan G.; Wijnperle, Daniël; de Boer, Hans L.; van den Berg, Albert; Schasfoort, Richardus B.M.

2010-01-01

We present an electrokinetic label-free biomolecular screening chip (Glass/PDMS) to screen up to 10 samples simultaneously using surface plasmon resonance imaging (iSPR). This approach reduces the duration of an experiment when compared to conventional experimental methods. This new device offers a

Electrokinetic migration across artificial liquid membranes. New concept for rapid sample preparation of biological fluids.

Science.gov (United States)

Pedersen-Bjergaard, Stig; Rasmussen, Knut Einar

2006-03-24

Basic drug substances were transported across a thin artificial organic liquid membrane by the application of 300 V d.c. From a 300 microl aqueous donor compartment (containing 10 mM HCl), the drugs migrated through a 200 microm artificial liquid membrane of 2-nitrophenyl octyl ether immobilized in the pores of a polypropylene hollow fiber, and into a 30 microl aqueous acceptor solution of 10 mM HCl inside the lumen of the hollow fiber. The transport was forced by an electrical potential difference sustained over the liquid membrane, resulting in electrokinetic migration of drug substances from the donor compartment to the acceptor solution. Within 5 min of operation at 300 V, pethidine, nortriptyline, methadone, haloperidol, and loperamide were extracted with recoveries in the range 70-79%, which corresponded to enrichments in the range 7.0-7.9. The chemical composition of the organic liquid membrane strongly affected the permeability, and may serve as an efficient tool for controlling the transport selectivity. Water samples, human plasma, and human urine were successfully processed, and in light of the present report, electrokinetic migration across thin artificial liquid membranes may be an interesting tool for future isolation within chemical analysis.

Numerical Simulations of Electrokinetic Processes Comparing the Use of a Constant Voltage Difference or a Constant Current as Driving Force

DEFF Research Database (Denmark)

Paz-Garcia, Juan Manuel; Johannesson, Björn; Ottosen, Lisbeth M.

Electrokinetic techniques are characterized by the use of a DC current for the removal of contaminants from porous materials. The method can be applied for several purposes, such as the recuperation of soil contaminated by heavy metals or organic compounds, the desalination of construction...... materials and the prevention of the reinforced concrete corrosion. The electrical energy applied in an electrokinetic process produces electrochemical reactions at the electrodes. Different electrode processes can occur. When considering inert electrodes in aqueous solutions, the reduction of water...... at the cathode is usually the dominant in the process. On the other hand, the electrode processes at the anode depend on the ions present in its vicinity. Oxidation of water and chloride are typically assumed to be the most common processes taking place. Electrons produced in the electrode processes...

Fluid Flow and Mixing Induced by AC Continuous Electrowetting of Liquid Metal Droplet

Directory of Open Access Journals (Sweden)

Qingming Hu

2017-04-01

Full Text Available In this work, we proposed a novel design of a microfluidic mixer utilizing the amplified Marangoni chaotic advection induced by alternating current (AC continuous electrowetting of a metal droplet situated in electrolyte solution, due to the linear and quadratic voltage-dependence of flow velocity at small or large voltages, respectively. Unlike previous researchers exploiting the unidirectional surface stress with direct current (DC bias at droplet/medium interface for pumping of electrolytes where the resulting flow rate is linearly proportional to the field intensity, dominance of another kind of dipolar flow pattern caused by local Marangoni stress at the drop surface in a sufficiently intense AC electric field is demonstrated by both theoretical analysis and experimental observation, which exhibits a quadratic growth trend as a function of the applied voltage. The dipolar shear stress merely appears at larger voltages and greatly enhances the mixing performance by inducing chaotic advection between the neighboring laminar flow. The mixer design developed herein, on the basis of amplified Marangoni chaotic advection around a liquid metal droplet at larger AC voltages, has great potential for chemical reaction and microelectromechanical systems (MEMS actuator applications because of generating high-throughput and excellent mixing performance at the same time.

Optimisation of resolution in micellar electrokinetic chromatography by multivariate evaluation of electrolytes.

Science.gov (United States)

Mikaeli, S; Thorsén, G; Karlberg, B

2001-01-12

A novel approach to multivariate evaluation of separation electrolytes for micellar electrokinetic chromatography is presented. An initial screening of the experimental parameters is performed using a Plackett-Burman design. Significant parameters are further evaluated using full factorial designs. The total resolution of the separation is calculated and used as response. The proposed scheme has been applied to the optimisation of the separation of phenols and the chiral separation of (+)-1-(9-anthryl)-2-propyl chloroformate-derivatized amino acids. A total of eight experimental parameters were evaluated and optimal conditions found in less than 48 experiments.

Comparison of migration modeling in micellar electrokinetic chromatography by linear regression and by use of an artificial neural network

NARCIS (Netherlands)

Metting, HJ; van Zomeren, PV; van der Ley, CP; Coenegracht, PMJ; de Jong, GJ

2000-01-01

The concentrations of modifier (methanol or acetonitrile) and surfactant (sodium dodecyl sulfate SDS) in the running buffer are important factors influencing the mobility of analytes in micellar electrokinetic chromatography (MEKC). Response surfaces of the effective mobility can be used to predict

ACS Zero Point Verification

Science.gov (United States)

Dolphin, Andrew

2005-07-01

The uncertainties in the photometric zero points create a fundamental limit to the accuracy of photometry. The current state of the ACS calibration is surprisingly poor, with zero point uncertainties of 0.03 magnitudes. The reason for this is that the ACS calibrations are based primarily on semi-emprical synthetic zero points and observations of fields too crowded for accurate ground-based photometry. I propose to remedy this problem by obtaining ACS images of the omega Cen standard field with all nine broadband ACS/WFC filters. This will permit the direct determination of the ACS zero points by comparison with excellent ground-based photometry, and should reduce their uncertainties to less than 0.01 magnitudes. A second benefit is that it will facilitate the comparison of the WFPC2 and ACS photometric systems, which will be important as WFPC2 is phased out and ACS becomes HST's primary imager. Finally, three of the filters will be repeated from my Cycle 12 observations, allowing for a measurement of any change in sensitivity.

Experimental and numerical study of deposit formation in secondary side SG TSP by electrokinetic approach

International Nuclear Information System (INIS)

Guillodo, Michael; Foucault, Marc; Ryckelynck, Natacha; Chahma, Farah; Guingo, Mathieu; Mansour, Carine; Alos-Ramos, Olga; Corredera, Geraldine

2012-09-01

Corrosion products deposit formation observed in PWR steam generators (SGs) - related to SG free span fouling and SG clogging - is now reported since several years. SG clogging is a localized phenomenon observed between the leading edge of the Tube Support Plate (TSP) and SG tubing materials. Based on visual inspections, it was found that the gaps between SG tubing material and TSP at the lower part of the broached holes were getting progressively blocked. Therefore, for safe operation, most affected PWRs had to be operated at reduced power. TSP blockage was mainly observed for low-pH water chemistry conditioning, which directly depends on the operating water chemistry. The TSP blockage mechanism is complex due to the localized conditions in which flow pattern change, chemistry and electrochemical conditions are not well understood. Electrokinetic considerations could be pointed out to explain the coupling of chemistry, materials and thermohydraulic (T/H) conditions. In this frame AREVA and EDF have launched a long-term R and D program in order to understand the mechanisms driving the formation of SG clogging. This study based on parametric laboratory tests aims to assess the role of secondary water chemistry, material and T/H conditions on deposit formation. The experimental approach focused on electrokinetic measurements of metallic substrates and on the assessment of oxidation properties of materials in secondary side chemistry. An overall analysis of recent results is presented to address SG deposit formation in secondary water chemistry for various conditioning amines - morpholine, ethanolamine and dimethylamine. To complete the study, the experimental results have been correlated to CFD simulations of particle deposition, by means of stochastic Lagrangian models. These calculations have in particular reproduced correctly the location of the most important particle deposit (the leading edge of the test tube), and have stressed the influence of the

Electrokinetic desalination of sandstones for NaCl removal

DEFF Research Database (Denmark)

Ottosen, Lisbeth M.; Christensen, Iben V.

2012-01-01

of reliable methods to remove the damaging salts in order to stop the decay. Electrokinetic desalination of fired clay bricks have previously shown efficient in laboratory scale and in the present work the method is tested for desalination of Cotta and Posta sandstones, which both have lower porosity than...... each stone, but electroosmosis in the poultices may have caused suction/pressure over the interface between stone and poultice causing the differences in poultice water content. The transport numbers for Cl− and Na+ differed in the two stones and were highest in the most porous Cotta sandstone in spite...... of similar high pore water concentrations and the same applied electric current. The hypotheses is that a layered structure of the sandstones could be the cause for this, as the electric current may preferentially flow in certain paths through the stone, which are thus desalinated first. After...

Salt Induced Decay of Masonry and Electrokinetic Repair

DEFF Research Database (Denmark)

Ottosen, Lisbeth M.; Rörig-Dalgaard, Inge

in brick depending on its water content and salts may be precipitated on the outer wall or concentrated under paint layers covering the surface of the brick. Different types of damage may appear in masonry walls due to these concentrating phenomena. Bricks themselves can be destroyed and the mortar can...... of bricks without increased salt content is very low compared to soils in general. Furthermore in a masonry wall there are boundaries with different chemistry (e.g. pH) that the ions must pass, brick-mortar boundaries. From initial experiments with electrokinetic removal of Ca2+ ions from bricks good......Salt induced decay of bricks is caused when salts exert internal pressures, which exceed the strength of the stone. The presence of aqueous electrolyte solutions in the capillary pores of brick materials can under changing climate conditions cause deterioration of wall structures. Ions move...

ELECTROKINETIC DEVICE AND METHOD FOR CONSOLIDATING POROUS MATERIALS

DEFF Research Database (Denmark)

2017-01-01

The invention relates to a device and an associated electrokinetic method which allows the pores (superficial and deep) of a porous material to be filled, by forcing the precipitation therein of a product of low solubility in water by creating an electric field which will mobilise the cations...... and anions supplied by previously selected solutions. This method comprises two phases. In the first phase, the pores located at a specified distance from the surface of contact between the porous material and the anodic or cathodic compartment are plugged. In a second phase, the rest of the pores, mainly...... those which are on the surface level, are collapsed. As a result of the designed device and the plugging system contained therein, the porous material is not affected at any moment by chemical alteration processes caused by contact with extreme pH values. This device allows the treatment to be applied...

Rapid and label-free separation of Burkitt's lymphoma cells from red blood cells by optically-induced electrokinetics.

Directory of Open Access Journals (Sweden)

Wenfeng Liang

Full Text Available Early stage detection of lymphoma cells is invaluable for providing reliable prognosis to patients. However, the purity of lymphoma cells in extracted samples from human patients' marrow is typically low. To address this issue, we report here our work on using optically-induced dielectrophoresis (ODEP force to rapidly purify Raji cells' (a type of Burkitt's lymphoma cell sample from red blood cells (RBCs with a label-free process. This method utilizes dynamically moving virtual electrodes to induce negative ODEP force of varying magnitudes on the Raji cells and RBCs in an optically-induced electrokinetics (OEK chip. Polarization models for the two types of cells that reflect their discriminate electrical properties were established. Then, the cells' differential velocities caused by a specific ODEP force field were obtained by a finite element simulation model, thereby established the theoretical basis that the two types of cells could be separated using an ODEP force field. To ensure that the ODEP force dominated the separation process, a comparison of the ODEP force with other significant electrokinetics forces was conducted using numerical results. Furthermore, the performance of the ODEP-based approach for separating Raji cells from RBCs was experimentally investigated. The results showed that these two types of cells, with different concentration ratios, could be separated rapidly using externally-applied electrical field at a driven frequency of 50 kHz at 20 Vpp. In addition, we have found that in order to facilitate ODEP-based cell separation, Raji cells' adhesion to the OEK chip's substrate should be minimized. This paper also presents our experimental results of finding the appropriate bovine serum albumin concentration in an isotonic solution to reduce cell adhesion, while maintaining suitable medium conductivity for electrokinetics-based cell separation. In short, we have demonstrated that OEK technology could be a promising tool for

Adsorption pump for helium pumping out

International Nuclear Information System (INIS)

Donde, A.L.; Semenenko, Yu.E.

1981-01-01

Adsorption pump with adsorbent cooling by liquid helium is described. Shuttered shield protecting adsorbent against radiation is cooled with evaporating helium passing along the coil positioned on the shield. The pump is also equipped with primed cylindrical shield, cooled with liquid nitrogen. The nitrogen shield has in the lower part the shuttered shield, on the pump casing there is a valve used for pump pre-burning, and valves for connection to recipient as well. Pumping- out rates are presented at different pressures and temperatures of adsorbent. The pumping-out rate according to air at absorbent cooling with liquid nitrogen constituted 5x10 -4 Pa-3000 l/s, at 2x10 -2 Pa-630 l/s. During the absorbent cooling with liquid hydrogen the pumping-out rate according to air was at 4x10 -4 Pa-580 l/s, at 2x10 -3 Pa-680 l/s, according to hydrogen - at 8x10 -5 Pa-2500 l/s, at 5x10 -3 Pa-4200 l/s. During adsorbent cooling with liquid helium the rate of pumping-out according to hydrogen at 3x10 5 Pa-2400% l/s, at 6x10 3 Pa-1200 l/s, and according to helium at 3.5x10 -5 Pa-2800 l/s, at 4x10 -3 Pa-1150 l/s. The limit vacuum is equal to 1x10 -7 Pa. The volume of the vessel with liquid helium is equal to 3.5 l. Helium consumption is 80 cm 3 /h. Consumption of liquid nitrogen from the shield is 400 cm 3 /h. The limit pressure in the pump is obtained after forevacuum pumping-out (adsorbent regeneration) at 300 K temperature. The pump is made of copper. The pump height together with primed tubes is 800 mm diameter-380 mm [ru

Fluoro-apatite surface composition in aqueous solution deduced from potentiometric, electrokinetic, and solubility measurements, and spectroscopic observations

International Nuclear Information System (INIS)

Chairat, C.; Oelkers, E.H.; Schott, J.; Lartigue, J.E.

2007-01-01

The surface chemistry of fluoro-apatite in aqueous solution was investigated using electrokinetic techniques, potentiometric titrations, solubility measurements, and attenuated total reflection infrared spectroscopy. All methods indicate the formation of Ca/F depleted, P enriched altered layer via exchange reactions between H + and Ca 2+ , and OH - and F - at the fluoro-apatite (FAP) surface. Observations suggest that this leached layer has a di-calcium phosphate (CaHPO 4 ) composition and that it controls the apparent solubility of FAP. Electrokinetic measurements yield an iso-electric point value of 1 ± 0.5 consistent with a negatively charged FAP surface at pH ≥ 1. In contrast, surface titrations give an apparent pH of point of zero charge of similar to 7.7, consistent with a positively charged surface at pH ≤ 7.7. These differences are shown to stem from proton consumption by both proton exchange and dissolution reactions at the FAP surface. After taking account for these effects, FAP surface charge is shown to be negative to at least pH 4 by surface titration analysis. (authors)

A Novel Combination of Surfactant Addition and Persulfate-assisted Electrokinetic Oxidation for Remediation of Pyrene-Contaminated Soil

Directory of Open Access Journals (Sweden)

M. Abtahi

2018-03-01

Full Text Available Effect of surfactant addition on persulfate-assisted electrokinetic remediation of pyrene-spiked soil was studied. The influence of effective factors including voltage, surfactant addition, moisture content, and persulfate concentration on the removal of initial pyrene concentration of 200 mg kg–1 were investigated. A complete pyrene removal was observed for voltage of 1 V cm–1, saturated conditions, Tween 80 concentration of 20 mL kg–1, and persulfate concentration of 100 mg kg–1 after 24 h, corresponding to pyrene mineralization of 61 %, based on TPH analysis. The experimental results were best fitted with pseudo-first-order kinetic model with correlation coefficient of 0.968 and rate constant of 0.191 min−1. The main intermediates of pyrene degradation were benzene o-toluic acid, acetic, azulene, naphthalene and decanoic acid. Finally, an unwashed hydrocarbon-contaminated soil was subjected to persulfate-assisted electrokinetic remediation, and a TPH removal of 38 % was observed for the initial TPH content of 912 mg kg–1, under the selected conditions.

Low Offset AC Correlator.

Science.gov (United States)

This patent describes a low offset AC correlator avoids DC offset and low frequency noise by frequency operating the correlation signal so that low...noise, low level AC amplification can be substituted for DC amplification. Subsequently, the high level AC signal is demodulated to a DC level. (Author)

Determination of lysergic acid diethylamide (LSD) in mouse blood by capillary electrophoresis/ fluorescence spectroscopy with sweeping techniques in micellar electrokinetic chromatography.

Science.gov (United States)

Fang, Ching; Liu, Ju-Tsung; Chou, Shiu-Huey; Lin, Cheng-Huang

2003-03-01

The separation and on-line concentration of lysergic acid diethylamide (LSD) in mouse blood was achieved by means of capillary electrophoresis/fluorescence spectroscopy using sodium dodecyl sulfate (SDS) as the surfactant. Techniques involving on-line sample concentration, including sweeping micellar electrokinetic chromatography (sweeping-MEKC) and cation-selective exhaustive injection-sweep-micellar electrokinetic chromatography (CSEI-sweep-MEKC) were applied; the optimum on-line concentration and separation conditions were determined. In the analysis of an actual sample, LSD was found in a blood sample from a test mouse (0.1 mg LSD fed to a 20 g mouse; approximately 1/10 to the value of LD(50)). As a result, 120 and 30 ng/mL of LSD was detected at 20 and 60 min, respectively, after ingestion of the doses.

Vectorial Command of Induction Motor Pumping System Supplied by a Photovoltaic Generator

Science.gov (United States)

Makhlouf, Messaoud; Messai, Feyrouz; Benalla, Hocine

2011-01-01

With the continuous decrease of the cost of solar cells, there is an increasing interest and needs in photovoltaic (PV) system applications following standard of living improvements. Water pumping system powered by solar-cell generators are one of the most important applications. The fluctuation of solar energy on one hand, and the necessity to optimise available solar energy on the other, it is useful to develop new efficient and flexible modes to control motors that entrain the pump. A vectorial control of an asynchronous motor fed by a photovoltaic system is proposed. This paper investigates a photovoltaic-electro mechanic chain, composed of a PV generator, DC-AC converter, a vector controlled induction motor and centrifugal pump. The PV generator is forced to operate at its maximum power point by using an appropriate search algorithm integrated in the vector control. The optimization is realized without need to adding a DC-DC converter to the chain. The motor supply is also ensured in all insolation conditions. Simulation results show the effectiveness and feasibility of such an approach.

Rapid analysis of caffeine in “smart drugs” and “energy drinks” by microemulsion electrokinetic chromatography (MEEKC)

Czech Academy of Sciences Publication Activity Database

Liotta, E.; Gottardo, R.; Seri, C.; Rimondo, C.; Mikšík, Ivan; Serpelloni, G.; Tagliaro, F.

2012-01-01

Roč. 220, 1-3 (2012), s. 279-283 ISSN 0379-0738 R&D Projects: GA ČR(CZ) GA203/08/1428 Institutional research plan: CEZ:AV0Z50110509 Institutional support: RVO:67985823 Keywords : caffeine * energy drink * smart drug * microemulsion electrokinetic chromatography Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 2.307, year: 2012

Offshore Floating Wind Turbine-driven Deep Sea Water Pumping for Combined Electrical Power and District Cooling

Science.gov (United States)

Sant, T.; Buhagiar, D.; Farrugia, R. N.

2014-06-01

A new concept utilising floating wind turbines to exploit the low temperatures of deep sea water for space cooling in buildings is presented. The approach is based on offshore hydraulic wind turbines pumping pressurised deep sea water to a centralised plant consisting of a hydro-electric power system coupled to a large-scale sea water-cooled air conditioning (AC) unit of an urban district cooling network. In order to investigate the potential advantages of this new concept over conventional technologies, a simplified model for performance simulation of a vapour compression AC unit was applied independently to three different systems, with the AC unit operating with (1) a constant flow of sea surface water, (2) a constant flow of sea water consisting of a mixture of surface sea water and deep sea water delivered by a single offshore hydraulic wind turbine and (3) an intermittent flow of deep sea water pumped by a single offshore hydraulic wind turbine. The analysis was based on one year of wind and ambient temperature data for the Central Mediterranean that is known for its deep waters, warm climate and relatively low wind speeds. The study confirmed that while the present concept is less efficient than conventional turbines utilising grid-connected electrical generators, a significant portion of the losses associated with the hydraulic transmission through the pipeline are offset by the extraction of cool deep sea water which reduces the electricity consumption of urban air-conditioning units.

Offshore Floating Wind Turbine-driven Deep Sea Water Pumping for Combined Electrical Power and District Cooling

International Nuclear Information System (INIS)

Sant, T; Buhagiar, D; Farrugia, R N

2014-01-01

A new concept utilising floating wind turbines to exploit the low temperatures of deep sea water for space cooling in buildings is presented. The approach is based on offshore hydraulic wind turbines pumping pressurised deep sea water to a centralised plant consisting of a hydro-electric power system coupled to a large-scale sea water-cooled air conditioning (AC) unit of an urban district cooling network. In order to investigate the potential advantages of this new concept over conventional technologies, a simplified model for performance simulation of a vapour compression AC unit was applied independently to three different systems, with the AC unit operating with (1) a constant flow of sea surface water, (2) a constant flow of sea water consisting of a mixture of surface sea water and deep sea water delivered by a single offshore hydraulic wind turbine and (3) an intermittent flow of deep sea water pumped by a single offshore hydraulic wind turbine. The analysis was based on one year of wind and ambient temperature data for the Central Mediterranean that is known for its deep waters, warm climate and relatively low wind speeds. The study confirmed that while the present concept is less efficient than conventional turbines utilising grid-connected electrical generators, a significant portion of the losses associated with the hydraulic transmission through the pipeline are offset by the extraction of cool deep sea water which reduces the electricity consumption of urban air-conditioning units

Electrokinetic-Enhanced Remediation of Phenanthrene-Contaminated Soil Combined with Sphingomonas sp. GY2B and Biosurfactant.

Science.gov (United States)

Lin, Weijia; Guo, Chuling; Zhang, Hui; Liang, Xujun; Wei, Yanfu; Lu, Guining; Dang, Zhi

2016-04-01

Electrokinetic-microbial remediation (EMR) has emerged as a promising option for the removal of polycyclic aromatic hydrocarbons (PAHs) from contaminated soils. The aim of this study was to enhance degradation of phenanthrene (Phe)-contaminated soils using EMR combined with biosurfactants. The electrokinetic (EK) remediation, combined with Phe-degrading Sphingomonas sp. GY2B, and biosurfactant obtained by fermentation of Pseudomonas sp. MZ01, degraded Phe in the soil with an efficiency of up to 65.1 % at the anode, 49.9 % at the cathode after 5 days of the treatment. The presence of biosurfactants, electricity, and a neutral electrolyte stimulated the growth of the degrading bacteria as shown by a rapid increase in microbial biomass with time. The electrical conductivity and pH changed little during the course of the treatment, which benefitted the growth of microorganisms and the remediation of Phe-contaminated soil. The EMR system with the addition of biosurfactant had the highest Phe removal, demonstrating the biosurfactant may enhance the bioavailability of Phe and the interaction with the microorganism. This study suggests that the EMR combined with biosurfactants can be used to enhance in situ bioremediation of PAH-contaminated soils.

Dynamic Modelling of a Solar Water Pumping System with Energy Storage

OpenAIRE

Shatadru Biswas; M. Tariq Iqbal

2018-01-01

This paper describes the dynamic modelling of a system used for extraction of groundwater for irrigation using an alternative source of energy. The system is designed based on data of an existing project in Lalmonirhat, Bangladesh. The system comprises a 38.4 kWp solar photovoltaic array, inverter, AC motor, and pump set, which can discharge a maximum of 1,930 m3 of water per day. MATLAB simulation is performed with two types of energy storage system: (i) electric energy using a battery bank ...

Pumping mechanisms in sputter-ion pumps low pressure operation

International Nuclear Information System (INIS)

Welch, K.M.

1991-01-01

It is shown that significant H 2 pumping occurs in the walls of triode pumps. Also, H 2 is pumped in the anode cells of sputter-ion pumps. This pumping occurs in a manner similar to that by which the inert gases are pumped. That is, H 2 is pumped in the walls of the anode cells by high energy neutral burial. Hydrogen in the pump walls and anodes limits the base pressure of the pump

Zn (II) Removal from River Water Samples of Sembrong, Johor State, Malaysia by Electrokinetic Remediation

Science.gov (United States)

Zaidi, E.; Husna, MNF; Shakila, A.; Azhar, ATS; Arif, AM; Norshuhaila, MS

2017-08-01

Heavy metals pollution has become one of the most serious environmental problems today. The treatment of heavy metals is of special concern due to their recalcitrance and persistence in the environment. Even many physical, chemical and biological treatment processes have been proposed to remove heavy metals from river water, the use of these treatment processes are not efficient and relatively costly. This study focused on the potential application of electrokinetic (EK) remediation in Sembrong River water to remove zinc (Zn2+). The physicochemical and biological parameters and water quality index (WQI) of Sembrong River water was characterized. The electrokinetic remediation experiments were performed by controlling pH, and electric density on voltage were observed and investigated. The results indicated that all physicochemical and biological parameters of Sembrong River complied with the standard discharged limit set by the Department of Environment (DOE). However, suspended solids (SS) and pH can be categorized as Class III according to INWQS. The best performance of 88% efficiency of zinc can be achieved EK experiment run at a fixed voltage of 30 V at pH 5.14 after 60 min of the process operate. This technology may be proposed for faster and eco-friendly removal of heavy metals in the environment.

ACS Photometric Zero Point Verification

Science.gov (United States)

Dolphin, Andrew

2003-07-01

The uncertainties in the photometric zero points create a fundamental limit to the accuracy of photometry. The current state of the ACS calibration is surprisingly poor, with zero point uncertainties of 0.03 magnitudes in the Johnson filters. The reason for this is that ACS observations of excellent ground-based standard fields, such as the omega Cen field used for WFPC2 calibrations, have not been obtained. Instead, the ACS photometric calibrations are based primarily on semi-emprical synthetic zero points and observations of fields too crowded for accurate ground-based photometry. I propose to remedy this problem by obtaining ACS broadband images of the omega Cen standard field with both the WFC and HRC. This will permit the direct determination of the ACS transformations, and is expected to double the accuracy to which the ACS zero points are known. A second benefit is that it will facilitate the comparison of the WFPC2 and ACS photometric systems, which will be important as WFPC2 is phased out and ACS becomes HST's primary imager.

Pumping mechanisms in sputter-ion pumps low pressure operation

International Nuclear Information System (INIS)

Welch, K.M.

1991-01-01

It is shown that significant H 2 pumping occurs in the walls of triode pumps. Also, H 2 is pumped in the anode cells of sputter-ion pumps. This pumping occurs in a manner similar to that by which the inert gases are pumped. That is, H 2 pumped in the walls of the anode cells by high energy neutral burial. Hydrogen in the pump walls and anodes limits the base pressure of the pump. 13 refs., 5 figs., 1 tab

Toxic Elements in Soil and Groundwater: Short-Time Study on Electrokinetic Removal of Arsenic in the Presence of other Ions

Directory of Open Access Journals (Sweden)

Hafiz Ahmad

2006-06-01

Full Text Available The electrokinetic technique is an emerging technology presently tested in situ to remove dissolved heavy metals from contaminated groundwater. There is a growing interest for using this system to cleanse clayey soil contaminated by toxic metallic ions. Currently, there are very few available non-destructive treatment methods that could be successfully applied in situ on low permeable type of soil matrix. The main objective of presented study was to validate and possibly enhance the overall efficiency of decontamination by the electrokinetic technique of the low permeable soil polluted by the arsenic in combination with chromium and copper ions. The chosen mixture of ions was imitating leak of pesticide well known as chromate copper arsenate (CCA. The chosen technique is showing a big promise to be used in the future as a portable, easy to install and run on sites with spills or leaks hard to reach otherwise; such as in the dense populated and urbanized areas. Laboratory electrokinetic experiments were designed to understand and possibly manipulate main mechanisms involved during forced migration of ions. All tests were conducted on artificially contaminated kaolinite (low permeable clay soil. Electrokinetic migration was inducted by the low voltage dc current applied through soil column. Series of experiments were designed to assess the efficiency of arsenic-chromium-copper remediation by applying (1 only dc current; and (2 by altering the soil environment. Obtained results showed that arsenic could be successfully removed from the soil in one day (25 hours span. It was significant time reduction, very important during emergency response. Mass recovered at the end of each test depended on initial condition of soil and type of flushing solution. The best results were obtained, when soil was flushed with either NaOH or NaOCl (total removal efficiency 74.4% and 78.1%, respectively. Direct analysis of remained arsenic in soil after these tests

FLUIDIC AC AMPLIFIERS.

Science.gov (United States)

Several fluidic tuned AC Amplifiers were designed and tested. Interstage tuning and feedback designs are considered. Good results were obtained...corresponding Q’s as high as 12. Element designs and test results of one, two, and three stage amplifiers are presented. AC Modulated Carrier Systems

78 FR 49318 - Availability of Draft Advisory Circular (AC) 90-106A and AC 20-167A

Science.gov (United States)

2013-08-13

...] Availability of Draft Advisory Circular (AC) 90-106A and AC 20- 167A AGENCY: Federal Aviation Administration... of draft Advisory Circular (AC) 90-106A, Enhanced Flight Vision Systems and draft AC 20- 167A... Federal holidays. FOR FURTHER INFORMATION CONTACT: For technical questions concerning draft AC 90-106A...

Deletion of the AcMNPV core gene ac109 results in budded virions that are non-infectious

International Nuclear Information System (INIS)

Fang Minggang; Nie, Yingchao; Theilmann, David A.

2009-01-01

Autographa californica multiple nucleopolyhedrovirus (AcMNPV) ac109 is a core gene and its function in the virus life cycle is unknown. To determine its role in the baculovirus life cycle, we used the AcMNPV bacmid system to generate an ac109 deletion virus (vAc 109KO ). Fluorescence and light microscopy showed that transfection of vAc 109KO results in a single-cell infection phenotype. Viral DNA replication is unaffected and the development of occlusion bodies in vAc 109KO -transfected cells evidenced progression to the very late phases of viral infection. Western blot and confocal immunofluorescence analysis showed that AC109 is expressed in the cytoplasm and nucleus throughout infection. In addition, AC109 is a structural protein as it was detected in both budded virus (BV) and occlusion derived virus in both the envelope and nucleocapsid fractions. Titration assays by qPCR and TCID 50 showed that vAc 109KO produced BV but the virions are non-infectious. The vAc 109KO BV were indistinguishable from the BV of repaired and wild type control viruses as determined by negative staining and electron microscopy.

Development of a hardware-based AC microgrid for AC stability assessment

Science.gov (United States)

Swanson, Robert R.

As more power electronic-based devices enable the development of high-bandwidth AC microgrids, the topic of microgrid power distribution stability has become of increased interest. Recently, researchers have proposed a relatively straightforward method to assess the stability of AC systems based upon the time-constants of sources, the net bus capacitance, and the rate limits of sources. In this research, a focus has been to develop a hardware test system to evaluate AC system stability. As a first step, a time domain model of a two converter microgrid was established in which a three phase inverter acts as a power source and an active rectifier serves as an adjustable constant power AC load. The constant power load can be utilized to create rapid power flow transients to the generating system. As a second step, the inverter and active rectifier were designed using a Smart Power Module IGBT for switching and an embedded microcontroller as a processor for algorithm implementation. The inverter and active rectifier were designed to operate simultaneously using a synchronization signal to ensure each respective local controller operates in a common reference frame. Finally, the physical system was created and initial testing performed to validate the hardware functionality as a variable amplitude and variable frequency AC system.

Centrifugal pumps

CERN Document Server

Anderson, HH

1981-01-01

Centrifugal Pumps describes the whole range of the centrifugal pump (mixed flow and axial flow pumps are dealt with more briefly), with emphasis on the development of the boiler feed pump. Organized into 46 chapters, this book discusses the general hydrodynamic principles, performance, dimensions, type number, flow, and efficiency of centrifugal pumps. This text also explains the pumps performance; entry conditions and cavitation; speed and dimensions for a given duty; and losses. Some chapters further describe centrifugal pump mechanical design, installation, monitoring, and maintenance. The

Electrokinetic Supercapacitor for Simultaneous Harvesting and Storage of Mechanical Energy.

Science.gov (United States)

Yang, Peihua; Qu, Xiaopeng; Liu, Kang; Duan, Jiangjiang; Li, Jia; Chen, Qian; Xue, Guobin; Xie, Wenke; Xu, Zhimou; Zhou, Jun

2018-03-07

Energy harvesting and storage are two distinct processes that are generally achieved using two separated parts based on different physical and chemical principles. Here we report a self-charging electrokinetic supercapacitor that directly couples the energy harvesting and storage processes into one device. The device consists of two identical carbon nanotube/titanium electrodes, separated by a piece of anodic aluminum oxide nanochannels membrane. Pressure-driven electrolyte flow through the nanochannels generates streaming potential, which can be used to charge the capacitive electrodes, accomplishing simultaneous energy generation and storage. The device stores electric charge density of 0.4 mC cm -2 after fully charging under pressure of 2.5 bar. This work may offer a train of thought for the development of a new type of energy unit for self-powered systems.

Preliminary tests of an electrokinetic barrier to prevent heavy metal pollution of soils

International Nuclear Information System (INIS)

Lynch, R.J.; Muntoni, A.; Ruggeri, R.; Winfield, K.C.

2007-01-01

Sardinia has to deal with significant environmental problems related to heavy-metal contamination, mainly located at its abandoned mining districts. In particular, acid mine drainage management and groundwater pollution are typical problems associated with mining activities which constitute a serious threat to human health. To prevent contaminant spread over the adjacent environment, it is of great interest to consider using an electric field as a containment fence to counteract pollutant transport. In this application, contaminant transport due to a hydraulic gradient driving force is prevented by the combined effect of electro-osmosis and electro-migration. Although there are other alternative containment technologies, the electrokinetic fence offers many advantages, as it is easy to operate, there is a minimal exposure to the operating personnel and it is likely to be effective for a wide range of contaminants. In this work, both one-dimensional (1D) and two-dimensional (2D) tests have been carried out. In the 1D tests, the efficiency of an electrokinetic barrier to prevent cadmium from polluting an uncontaminated sample was investigated; soil pH, metal concentration and current intensity have been monitored; results indicate that the barrier can prevent or significantly reduce heavy-metal contamination from spreading against a hydraulic gradient of 7. In 2D tests, two rows of electrodes inserted in a horizontally flat soil tank were used to generate an electric field. It was found that an electric field of 125 V m -1 was sufficient to prevent significant copper incursion from a contaminant flow under a hydraulic gradient of 1.3

Electrokinetic treatment of firing ranges containing tungsten-contaminated soils

International Nuclear Information System (INIS)

Braida, Washington; Christodoulatos, Christos; Ogundipe, Adebayo; Dermatas, Dimitris; O'Connor, Gregory

2007-01-01

Tungsten-based alloys and composites are being used and new formulations are being considered for use in the manufacturing of different types of ammunition. The use of tungsten heavy alloys (WHA) in new munitions systems and tungsten composites in small caliber ammunition could potentially release substantial amounts of this element into the environment. Although tungsten is widely used in industrial and military applications, tungsten's potential environmental and health impacts have not been thoroughly addressed. This necessitates the research and development of remedial technologies to contain and/or remove tungsten from soils that may serve as a source for water contamination. The current work investigates the feasibility of using electrokinetics for the remediation of tungsten-contaminated soils in the presence of other heavy metals of concern such as Cu and Pb with aim to removing W from the soil while stabilizing in situ, Pb and Cu

LMFBR with booster pump in pumping loop

International Nuclear Information System (INIS)

Rubinstein, H.J.

1975-01-01

A loop coolant circulation system is described for a liquid metal fast breeder reactor (LMFBR) utilizing a low head, high specific speed booster pump in the hot leg of the coolant loop with the main pump located in the cold leg of the loop, thereby providing the advantages of operating the main pump in the hot leg with the reliability of cold leg pump operation

Bacterial surface appendages strongly impact nanomechanical and electrokinetic properties of Escherichia coli cells subjected to osmotic stress.

Directory of Open Access Journals (Sweden)

Grégory Francius

Full Text Available The physicochemical properties and dynamics of bacterial envelope, play a major role in bacterial activity. In this study, the morphological, nanomechanical and electrohydrodynamic properties of Escherichia coli K-12 mutant cells were thoroughly investigated as a function of bulk medium ionic strength using atomic force microscopy (AFM and electrokinetics (electrophoresis. Bacteria were differing according to genetic alterations controlling the production of different surface appendages (short and rigid Ag43 adhesins, longer and more flexible type 1 fimbriae and F pilus. From the analysis of the spatially resolved force curves, it is shown that cells elasticity and turgor pressure are not only depending on bulk salt concentration but also on the presence/absence and nature of surface appendage. In 1 mM KNO(3, cells without appendages or cells surrounded by Ag43 exhibit large Young moduli and turgor pressures (∼700-900 kPa and ∼100-300 kPa respectively. Under similar ionic strength condition, a dramatic ∼50% to ∼70% decrease of these nanomechanical parameters was evidenced for cells with appendages. Qualitatively, such dependence of nanomechanical behavior on surface organization remains when increasing medium salt content to 100 mM, even though, quantitatively, differences are marked to a much smaller extent. Additionally, for a given surface appendage, the magnitude of the nanomechanical parameters decreases significantly when increasing bulk salt concentration. This effect is ascribed to a bacterial exoosmotic water loss resulting in a combined contraction of bacterial cytoplasm together with an electrostatically-driven shrinkage of the surface appendages. The former process is demonstrated upon AFM analysis, while the latter, inaccessible upon AFM imaging, is inferred from electrophoretic data interpreted according to advanced soft particle electrokinetic theory. Altogether, AFM and electrokinetic results clearly demonstrate the

Interpretation of electrokinetic measurements with porous films: role of electric conductance and streaming current within porous structure.

Science.gov (United States)

Yaroshchuk, Andriy; Luxbacher, Thomas

2010-07-06

It is shown that in tangential electrokinetic measurements with porous films the porous structure makes contribution not only to the cell electric conductance (as demonstrated previously) but also to the observed streaming current. Both of these contributions give rise to dependences of streaming-potential and streaming-current coefficients on the channel height. However, due to the combined contribution of two phenomena, the dependence of streaming-potential coefficient on the channel height may be rather complicated and not allow for simple extrapolation. At the same time, the dependences of streaming-current coefficient and cell electric conductance on the channel height turn out linear and can be easily extrapolated to zero channel heights. This enables one to determine separately the contributions of external surface of porous film and of its porous structure to the streaming current and of the channel and porous structure to the cell electric conductance. This procedure is illustrated by the measurements of tangential electrokinetic phenomena and electric conductance with Millipore mixed-cellulose membrane filters of various average pore sizes (from 0.025 to 5 mum) in the so-called adjustable-gap cell of SurPASS electrokinetic instrument (Anton Paar GmbH). The design of this cell allows for easy and quasi-continuous variation of channel height as well as accurate determination of cell electric conductance, streaming-current coefficient, and channel height (from the cell hydraulic permeability). The quality of linear fits of experimental data has been found to be very good, and thus, the extrapolation procedures were quite reliable and accurate. Zeta-potentials could be determined of both external film and internal pore surfaces. It is demonstrated that the porous structures make considerable contributions to both streaming-current coefficient and cell electric conductance especially in the case of filters with larger pores. It is also found that, rather

Method for a microfluidic weaklink device

Science.gov (United States)

Shepodd, Timothy J [Livermore, CA; Duncan, Matthew P [Augusta, GA

2009-12-01

The present invention relates to an electrokinetic (EK) pump capable of creating high pressures electroosmotically, and capable of retaining high pressures. Both pressure creation and retention are accomplished without the need for moving parts. The EK pump uses a polymerizable fluid that creates the pressure-retaining seal within the EK pump when polymerization is initiated, typically by exposure to UV radiation. Weaklink devices are advantageously constructed including such a pressure-retaining EK pump since, among other advantages, the response of the weaklink device relies on predictable and reliable chemical polymerization reactions.

Steady electrodiffusion in hydrogel-colloid composites: macroscale properties from microscale electrokinetics

Directory of Open Access Journals (Sweden)

Reghan J. Hill

2010-03-01

Full Text Available A rigorous microscale electrokinetic model for hydrogel-colloid composites is adopted to compute macroscale profiles of electrolyte concentration, electrostatic potential, and hydrostatic pressure across membranes that separate electrolytes with different concentrations. The membranes are uncharged polymeric hydrogels in which charged spherical colloidal particles are immobilized and randomly dispersed with a low solid volume fraction. Bulk membrane characteristics and performance are calculated from a continuum microscale electrokinetic model (Hill 2006b, c. The computations undertaken in this paper quantify the streaming and membrane potentials. For the membrane potential, increasing the volume fraction of negatively charged inclusions decreases the differential electrostatic potential across the membrane under conditions where there is zero convective flow and zero electrical current. With low electrolyte concentration and highly charged nanoparticles, the membrane potential is very sensitive to the particle volume fraction. Accordingly, the membrane potential - and changes brought about by the inclusion size, charge and concentration - could be a useful experimental diagnostic to complement more recent applications of the microscale electrokinetic model for electrical microrheology and electroacoustics (Hill and Ostoja-Starzewski 2008, Wang and Hill 2008.Um modelo eletrocinético rigoroso para compósitos formados por um hidrogel e um colóide é adotado para computar os perfis macroscópicos de concentração eletrolítica, potencial eletrostático e pressão hidrostática através de uma membrana que separa soluções com diferentes concentrações eletrolíticas. A membrana é composta por um hidrogel polimérico sem carga elétrica onde partículas esféricas são imobilizadas e dispersas aleatoriamente com baixa fração de volume do sólido. As características da membrana e a sua performance são calculadas a partir de um modelo

Estimating BrAC from transdermal alcohol concentration data using the BrAC estimator software program.

Science.gov (United States)

Luczak, Susan E; Rosen, I Gary

2014-08-01

Transdermal alcohol sensor (TAS) devices have the potential to allow researchers and clinicians to unobtrusively collect naturalistic drinking data for weeks at a time, but the transdermal alcohol concentration (TAC) data these devices produce do not consistently correspond with breath alcohol concentration (BrAC) data. We present and test the BrAC Estimator software, a program designed to produce individualized estimates of BrAC from TAC data by fitting mathematical models to a specific person wearing a specific TAS device. Two TAS devices were worn simultaneously by 1 participant for 18 days. The trial began with a laboratory alcohol session to calibrate the model and was followed by a field trial with 10 drinking episodes. Model parameter estimates and fit indices were compared across drinking episodes to examine the calibration phase of the software. Software-generated estimates of peak BrAC, time of peak BrAC, and area under the BrAC curve were compared with breath analyzer data to examine the estimation phase of the software. In this single-subject design with breath analyzer peak BrAC scores ranging from 0.013 to 0.057, the software created consistent models for the 2 TAS devices, despite differences in raw TAC data, and was able to compensate for the attenuation of peak BrAC and latency of the time of peak BrAC that are typically observed in TAC data. This software program represents an important initial step for making it possible for non mathematician researchers and clinicians to obtain estimates of BrAC from TAC data in naturalistic drinking environments. Future research with more participants and greater variation in alcohol consumption levels and patterns, as well as examination of gain scheduling calibration procedures and nonlinear models of diffusion, will help to determine how precise these software models can become. Copyright © 2014 by the Research Society on Alcoholism.

The pumping of hydrogen and helium by sputter-ion pumps

International Nuclear Information System (INIS)

Welch, K.M.; Pate, D.J.; Todd, R.J.

1992-01-01

The pumping of hydrogen in diode and triode sputter-ion pumps is discussed. The type of cathode material used in these pumps is shown to have a significant impact on the effectiveness with which hydrogen is pumped. Examples of this include data for pumps with aluminum and titanium-alloy cathodes. Diode pumps with aluminum cathodes are shown to be no more effective in the pumping of hydrogen than in the pumping of helium. The use of titanium or titanium alloy anodes is also shown to measurably impact on the speed of these pumps at.very low pressures. This stems from the fact that hydrogen is x10 6 more soluble in titanium than in stainless steel. Hydrogen becomes resident in the anodes because of fast neutral burial. Lastly, quantitative data are given for the He speeds and capacities of both noble and conventional diode and triode pumps. The effectiveness of various pump regeneration procedures, subsequent to the pumping of He, is reported.These included bakeout and N 2 glow discharge cleaning. The comparative desorption of He with the subsequent pumping of N 2 is reported on. The N 2 speed of these pumps was used as the benchmark for defining the size of the pumps vs. their respective He speeds

Liquid metals pumping

International Nuclear Information System (INIS)

Le Frere, J.P.

1984-01-01

Pumps used to pump liquid metals depend on the liquid metal and on the type of application concerned. One deals more particularly with electromagnetic pumps, the main pumps used with mechanical pumps. To pump sodium in the nuclear field, these two types of pumps are used; the pumps of different circuits of Super Phenix are presented and described [fr

Electrokinetic control of sample splitting at a channel bifurcation using isotachophoresis

International Nuclear Information System (INIS)

Persat, Alexandre; Santiago, Juan G

2009-01-01

We present a novel method for accurately splitting ionic samples at microchannel bifurcations. We leverage isotachophoresis (ITP) to focus and transport sample through a one-inlet, two-outlet microchannel bifurcation. We actively control the proportion of splitting by controlling potentials at end-channel reservoirs (and thereby controlling the current ratio). We explore the effect of buffer chemistry and local electric field on splitting dynamics and propose and validate a simple Kirchoff-type rule controlling the split ratio. We explore the effects of large applied electric fields on sample splitting and attribute a loss of splitting accuracy to electrohydrodynamic instabilities. We propose a scaling analysis to characterize the onset of this instability. This scaling is potentially useful for other electrokinetic flow problems with self-sharpening interfaces.

Continuously pumping and reactivating gas pump

International Nuclear Information System (INIS)

Batzer, T.H.; Call, W.R.

1984-01-01

Apparatus for continuous pumping using cycling cyropumping panels. A plurality of liquid helium cooled panels are surrounded by movable nitrogen cooled panels the alternatively expose or shield the helium cooled panels from the space being pumped. Gases condense on exposed helium cooled panels until the nitrogen cooled panels are positioned to isolate the helium cooled panels. The helium cooled panels are incrementally warmed, causing captured gases to accumulate at the base of the panels, where an independent pump removes the gases. After the helium cooled panels are substantially cleaned of condensate, the nitrogen cooled panels are positioned to expose the helium cooled panels to the space being pumped

Continuously pumping and reactivating gas pump

Science.gov (United States)

Batzer, Thomas H.; Call, Wayne R.

1984-01-01

Apparatus for continuous pumping using cycling cyropumping panels. A plurality of liquid helium cooled panels are surrounded by movable nitrogen cooled panels the alternatively expose or shield the helium cooled panels from the space being pumped. Gases condense on exposed helium cooled panels until the nitrogen cooled panels are positioned to isolate the helium cooled panels. The helium cooled panels are incrementally warmed, causing captured gases to accumulate at the base of the panels, where an independent pump removes the gases. After the helium cooled panels are substantially cleaned of condensate, the nitrogen cooled panels are positioned to expose the helium cooled panels to the space being pumped.

RHIC spin flipper AC dipole controller

Energy Technology Data Exchange (ETDEWEB)

Oddo, P.; Bai, M.; Dawson, C.; Gassner, D.; Harvey, M.; Hayes, T.; Mernick, K.; Minty, M.; Roser, T.; Severino, F.; Smith, K.

2011-03-28

The RHIC Spin Flipper's five high-Q AC dipoles which are driven by a swept frequency waveform require precise control of phase and amplitude during the sweep. This control is achieved using FPGA based feedback controllers. Multiple feedback loops are used to and dynamically tune the magnets. The current implementation and results will be presented. Work on a new spin flipper for RHIC (Relativistic Heavy Ion Collider) incorporating multiple dynamically tuned high-Q AC-dipoles has been developed for RHIC spin-physics experiments. A spin flipper is needed to cancel systematic errors by reversing the spin direction of the two colliding beams multiple times during a store. The spin flipper system consists of four DC-dipole magnets (spin rotators) and five AC-dipole magnets. Multiple AC-dipoles are needed to localize the driven coherent betatron oscillation inside the spin flipper. Operationally the AC-dipoles form two swept frequency bumps that minimize the effect of the AC-dipole dipoles outside of the spin flipper. Both AC bumps operate at the same frequency, but are phase shifted from each other. The AC-dipoles therefore require precise control over amplitude and phase making the implementation of the AC-dipole controller the central challenge.

Removal of uranium from contaminated soil using indoor electrokinetic decontamination

International Nuclear Information System (INIS)

Gye-Nam Kim; Ilgook Kim; Seung-Soo Kim; Jong-Won Choi

2016-01-01

Indoor electrokinetic decontamination equipment was manufactured to treat 1.2 tons of uranium-contaminated soil. For a reduction of waste electrolyte and metal oxide, waste electrolyte was reused and the optimum pH was adjusted to minimize metal oxide volume in the cathode chamber. It was found that the optimum pH of the waste electrolyte in a cathode chamber was below 2.35 at 25 deg C. When the initial uranium concentrations in the soils were 7.0-27.0 Bq/g, the reuse periods of waste electrolyte required for uranium concentrations in the soils to reach below 5.0 Bq/g were 5-25 days. In addition, when the initial concentrations in the soils were 7.0-20.0 Bq/g, the periods required to reach below the clearance concentration level were 25-40 days.

Effect of pump limiter throat on pumping efficiency

International Nuclear Information System (INIS)

Ghendrih, P.; Grosman, A.; Samain, A.; Capes, H.; Morera, J.P.

1988-01-01

The necessary control of plasma edge density has led to the development of pump limiters to achieve this task. On Tore Supra, where a large part of the program is devoted to plasma edge studies, two types of such density control apparatus have been implemented, a set of pump limiters and the pumps associated to the ergodic divertor (magnetically assisted pump limiters). Generally two different kinds of pump limiters can be used, those with a throat which drives the plasma from the open edge plasma (SOL) to the neutralizer plate, and those without or with a very short throat. We are interested here in this aspect of the pump limiter concept, i.e. on the throat effect on neutral density build-up in the vicinity of the pumping plates (and hence on pumping efficieny). The underlying idea of this throat effect can be readily understood; indeed while the neutral capture in pump limiters without throats is only a ballistic effect, on expects the plasma to improve the efficiency of pump-limiters via plasma-neutral-sidewall interactions in the throat. This problem has been studied both numerically and analytically. The paper is divided as follows. In section 2, we describe the basic features of pump-limiters which are modelized by the numerical code Cezanne. Section 3 is devoted to the throat length effect considering in particular the neutral density profile in the throat and the neutral density buil-up as a function of the throat lenght. In section 4, we show that the plugging effect occurs for reasonnable values of throat lengths. An analytical value of the plugging length is discussed and compared to the values obtained numerically

Electrokinetic remediation - a new process for in-situ remediation of polluted land used as construction terrain; Elektrokinetische Bodensanierung - Ein neues Verfahren fuer die in-situ Sanierung bebauter Altlaststandorte

Energy Technology Data Exchange (ETDEWEB)

Haus, R. [Karlsruhe Univ. (T.H.) (Germany). Lehrstuhl fuer Angewandte Geologie

1998-12-31

Electrokinetic Remediation is a coming up technology for the clean up of contaminated sites based on the electrokinetic phenomena in fine grained sediments. The following investigations offer theoretical and experimental consideration about the dependence of electrokinetic remediation techniques on the clay mineralogical composition of various clays. Finally, laboratory tests on the electroosmotic remediation of a chromate contaminated loess loam are presented. Different voltages applied led to important changes in the direction of chromate transport. When using low voltage (1 V) chromate transport was in the direction of water flow, and an increase of chromate in the effluent of the cathode could be measured. In contrast the application of high voltages up to 30 V changed the transport mechanism and high concentrations of chromate chould be detected in the anode reservoir. The results show that the clay mineral composition and the applied electric field controls the electroosmotic permeability, removal efficiency as well as the transport mechanism of the electrokinetic remediation technology in fine grained sediments. (orig.) [Deutsch] Elektrokinetische Verfahren werden in der Geotechnik zur Entwaesserung, Boeschungsstabilisierung und Bodenverbesserung von bindigen Sedimenten eingesetzt. Unter dem sanierungstechnischen Aspekt von kontaminierten Altlaststandorten ermoeglichen elektrokinetische Prozesse erstmals eine gezielte Mobilisierung von Schadstoffen (Schwermetalle, organische Verbindungen) auch in feinkoernigen Gesteinen. Entscheidend ist hierbei die Moeglichkeit eines in situ-Einsatzes unter Vermeidung des Bodenaushubes. Die vorliegenden Untersuchungen vertiefen in theoretischen und versuchstechnischen Betrachtungen die Abhaengigkeit elektrokinetischer Sanierungsverfahren von der tonmineralogischen Zusammensetzung bindiger Gesteine. Oberflaechenladung und Oberflaechenpotential ausgewaehlter Tonminerale werden quantifiziert und den Ergebnissen aus

Continuous Fractionation of a two-component mixture by zone electrophoresis

NARCIS (Netherlands)

Zalewski, D.R.; Gardeniers, Johannes G.E.

2009-01-01

Synchronized continuous-flow zone electrophoresis is a recently demonstrated tool for performing electrophoretic fractionation of a complex sample. The method resembles free flow electrophoresis, but unlike in that technique, no mechanical fluid pumping is required. Instead, fast electrokinetic flow

Experiments on pumping of liquids using arrays of microelectrodes subjected to travelling wave potentials

Energy Technology Data Exchange (ETDEWEB)

Garcia-Sanchez, P; Ramos, A [Dpto. de Electronica y Electromagnetismo, Universidad de Sevilla, 41012 Sevilla (Spain); Green, Nicolas G; Morgan, H [School of Electronics and Computer Science, University of Southampton, SO17 1BJ Southampton (United Kingdom)], E-mail: pablogarcia@us.es

2008-12-01

Net fluid flow of electrolytes driven on an array of microelectrodes subjected to a travelling-wave potential is presented. Two sizes of platinum microelectrodes have been studied. In both arrays, at low voltages the liquid flows according to the prediction given by ac electroosmotic theory. At voltages above a threshold the fluid flow is reversed. Measurements of the electrical current when the microelectrode array is pumping the liquid are also reported. Transient behaviours in both electrical current and fluid velocity have been observed.

Experiments on pumping of liquids using arrays of microelectrodes subjected to travelling wave potentials

International Nuclear Information System (INIS)

Garcia-Sanchez, P; Ramos, A; Green, Nicolas G; Morgan, H

2008-01-01

Net fluid flow of electrolytes driven on an array of microelectrodes subjected to a travelling-wave potential is presented. Two sizes of platinum microelectrodes have been studied. In both arrays, at low voltages the liquid flows according to the prediction given by ac electroosmotic theory. At voltages above a threshold the fluid flow is reversed. Measurements of the electrical current when the microelectrode array is pumping the liquid are also reported. Transient behaviours in both electrical current and fluid velocity have been observed.

Study of Hydrogen Pumping through Condensed Argon in Cryogenic pump

International Nuclear Information System (INIS)

Jadeja, K A; Bhatt, S B

2012-01-01

In ultra high vacuum (UHV) range, hydrogen is a dominant residual gas in vacuum chamber. Hydrogen, being light gas, pumping of hydrogen in this vacuum range is limited with widely used UHV pumps, viz. turbo molecular pump and cryogenic pump. Pre condensed argon layers in cryogenic pump create porous structure on the surface of the pump, which traps hydrogen gas at a temperature less than 20° K. Additional argon gas injection in the cryogenic pump, at lowest temperature, generates multiple layers of condensed argon as a porous frost with 10 to 100 A° diameters pores, which increase the pumping capacity of hydrogen gas. This pumping mechanism of hydrogen is more effective, to pump more hydrogen gas in UHV range applicable in accelerator, space simulation etc. and where hydrogen is used as fuel gas like tokamak. For this experiment, the cryogenic pump with a closed loop refrigerator using helium gas is used to produce the minimum cryogenic temperature as ∼ 14° K. In this paper, effect of cryosorption of hydrogen is presented with different levels of argon gas and hydrogen gas in cryogenic pump chamber.

Attaching NorA efflux pump inhibitors to methylene blue enhances antimicrobial photodynamic inactivation of Escherichia coli and Acinetobacter baumannii in vitro and in vivo.

Science.gov (United States)

Rineh, Ardeshir; Bremner, John B; Hamblin, Michael R; Ball, Anthony R; Tegos, George P; Kelso, Michael J

2018-02-24

Resistance of bacteria to antibiotics is a public health concern worldwide due to the increasing failure of standard antibiotic therapies. Antimicrobial photodynamic inactivation (aPDI) is a promising non-antibiotic alternative for treating localized bacterial infections that uses non-toxic photosensitizers and harmless visible light to produce reactive oxygen species and kill microbes. Phenothiazinium photosensitizers like methylene blue (MB) and toluidine blue O are hydrophobic cations that are naturally expelled from bacterial cells by multidrug efflux pumps, which reduces their effectiveness. We recently reported the discovery of a NorA efflux pump inhibitor-methylene blue (EPI-MB) hybrid compound INF55-(Ac)en-MB that shows enhanced photodynamic inactivation of the Gram-positive bacterium methicillin-resistant Staphylococcus aureus (MRSA) relative to MB, both in vitro and in vivo. Here, we report the surprising observation that INF55-(Ac)en-MB and two related hybrids bearing the NorA efflux pump inhibitors INF55 and INF271 also show enhanced aPDI activity in vitro (relative to MB) against the Gram-negative bacteria Escherichia coli and Acinetobacter baumannii, despite neither species expressing the NorA pump. Two of the hybrids showed superior effects to MB in murine aPDI infection models. The findings motivate wider exploration of aPDI with EPI-MB hybrids against Gram-negative pathogens and more detailed studies into the molecular mechanisms underpinning their activity. Copyright © 2018 Elsevier Ltd. All rights reserved.

Determination of the distribution constants of aromatic compounds and steroids in biphasic micellar phosphonium ionic liquid/aqueous buffer systems by capillary electrokinetic chromatography

Czech Academy of Sciences Publication Activity Database

Lokajová, Jana; Railila, A.; King, A. W. T.; Wiedmer, S. K.

2013-01-01

Roč. 1308, Sep 20 (2013), s. 144-151 ISSN 0021-9673 Institutional support: RVO:61388963 Keywords : critical micelle concentration * electrokinetic chromatography * distribution constant * PeakMaster * phosphonium ionic liquid Subject RIV: CC - Organic Chemistry Impact factor: 4.258, year: 2013

The AC photovoltaic module is here!

Science.gov (United States)

Strong, Steven J.; Wohlgemuth, John H.; Wills, Robert H.

1997-02-01

This paper describes the design, development, and performance results of a large-area photovoltaic module whose electrical output is ac power suitable for direct connection to the utility grid. The large-area ac PV module features a dedicated, integrally mounted, high-efficiency dc-to-ac power inverter with a nominal output of 250 watts (STC) at 120 Vac, 60 H, that is fully compatible with utility power. The module's output is connected directly to the building's conventional ac distribution system without need for any dc wiring, string combiners, dc ground-fault protection or additional power-conditioning equipment. With its advantages, the ac photovoltaic module promises to become a universal building block for use in all utility-interactive PV systems. This paper discusses AC Module design aspects and utility interface issues (including islanding).

Electrokinetic remediation of plutonium-contaminated nuclear site wastes: Results from a pilot-scale on-site trial

International Nuclear Information System (INIS)

Agnew, Kieran; Cundy, Andrew B.; Hopkinson, Laurence; Croudace, Ian W.; Warwick, Phillip E.; Purdie, Philip

2011-01-01

This paper examines the field-scale application of a novel low-energy electrokinetic technique for the remediation of plutonium-contaminated nuclear site soils, using soil wastes from the Atomic Weapons Establishment (AWE) Aldermaston site, Berkshire, UK as a test medium. Soils and sediments with varying composition, contaminated with Pu through historical site operations, were electrokinetically treated at laboratory-scale with and without various soil pre-conditioning agents. Results from these bench-scale trials were used to inform a larger on-site remediation trial, using an adapted containment pack with battery power supply. 2.4 m 3 (ca. 4 tonnes) of Pu-contaminated soil was treated for 60 days at a power consumption of 33 kW h/m 3 , and then destructively sampled. Radiochemical data indicate mobilisation of Pu in the treated soil, and migration (probably as a negatively charged Pu-citrate complex) towards the anodic compartment of the treatment cell. Soil in the cathodic zone of the treatment unit was remediated to a level below free-release disposal thresholds (1.7 Bq/g, or <0.4 Bq/g above background activities). The data show the potential of this method as a low-cost, on-site tool for remediation of radioactively contaminated soils and wastes which can be operated remotely on working sites, with minimal disruption to site infrastructure or operations.

Dry vacuum pumps

International Nuclear Information System (INIS)

Sibuet, R

2008-01-01

For decades and for ultimate pressure below 1 mbar, oil-sealed Rotary Vane Pumps have been the most popular solution for a wide range of vacuum applications. In the late 80ies, Semiconductor Industry has initiated the development of the first dry roughing pumps. Today SC applications are only using dry pumps and dry pumping packages. Since that time, pumps manufacturers have developed dry vacuum pumps technologies in order to make them attractive for other applications. The trend to replace lubricated pumps by dry pumps is now spreading over many other market segments. For the Semiconductor Industry, it has been quite easy to understand the benefits of dry pumps, in terms of Cost of Ownership, process contamination and up-time. In this paper, Technology of Dry pumps, its application in R and D/industries, merits over conventional pumps and future growth scope will be discussed

Off-Pump Versus On-Pump Coronary Artery Bypass Grafting

DEFF Research Database (Denmark)

Møller, Christian H; Steinbrüchel, Daniel A

2014-01-01

Coronary artery bypass grafting (CABG) remains the preferred treatment in patients with complex coronary artery disease. However, whether the procedure should be performed with or without the use of cardiopulmonary bypass, referred to as off-pump and on-pump CABG, is still up for debate....... Intuitively, avoidance of cardiopulmonary bypass seems beneficial as the systemic inflammatory response from extracorporeal circulation is omitted, but no single randomized trial has been able to prove off-pump CABG superior to on-pump CABG as regards the hard outcomes death, stroke or myocardial infarction....... In contrast, off-pump CABG is technically more challenging and may be associated with increased risk of incomplete revascularization. The purpose of the review is to summarize the current literature comparing outcomes of off-pump versus on-pump coronary artery bypass surgery....

Insights into head-column field-amplified sample stacking: Part I. Detailed study of electrokinetic injection of a weak base across a short water plug

Czech Academy of Sciences Publication Activity Database

Šesták, Jozef; Thormann, W.

2017-01-01

Roč. 1502, FEB (2017), s. 51-61 ISSN 0021-9673 Institutional support: RVO:68081715 Keywords : capillary electrophoresis * electrokinetic injection * simulation Subject RIV: CB - Analytical Chemistry, Separation OBOR OECD: Analytical chemistry Impact factor: 3.981, year: 2016

Influence of the Chemical Interactions on the Removal Rate of Different Salts in Electrokinetic Desalination Processes

DEFF Research Database (Denmark)

Paz-Garcia, Juan Manuel; Johannesson, Björn; Ottosen, Lisbeth M.

2011-01-01

Electrokinetic desalination techniques have been successfully applied for the prevention of salt-induced deterioration problems of masonry and other construction materials. A mathematical model for electrochemical desalination treatments is described, based on the Poisson-Nernst-Planck system...... of equations and accounting for the chemical interactions between the species in the pore solution and the solid matrix. Due to their high abundance in the natural environment, chlorides, nitrates and sulfates are considered the main ions responsible to the salt decay processes in buildings materials...

Heat pump technology

CERN Document Server

Von Cube, Hans Ludwig; Goodall, E G A

2013-01-01

Heat Pump Technology discusses the history, underlying concepts, usage, and advancements in the use of heat pumps. The book covers topics such as the applications and types of heat pumps; thermodynamic principles involved in heat pumps such as internal energy, enthalpy, and exergy; and natural heat sources and energy storage. Also discussed are topics such as the importance of the heat pump in the energy industry; heat pump designs and systems; the development of heat pumps over time; and examples of practical everyday uses of heat pumps. The text is recommended for those who would like to kno

Liquid metal pump

Science.gov (United States)

Pennell, William E.

1982-01-01

The liquid metal pump comprises floating seal rings and attachment of the pump diffuser to the pump bowl for isolating structural deflections from the pump shaft bearings. The seal rings also eliminate precision machining on large assemblies by eliminating the need for a close tolerance fit between the mounting surfaces of the pump and the seals. The liquid metal pump also comprises a shaft support structure that is isolated from the pump housing for better preservation of alignment of shaft bearings. The shaft support structure also allows for complete removal of pump internals for inspection and repair.

Liquid metal pump

International Nuclear Information System (INIS)

Pennell, W.E.

1982-01-01

The liquid metal pump comprises floating seal rings and attachment of the pump diffuser to the pump bowl for isolating structural deflections from the pump shaft bearings. The seal rings also eliminate precision machining on large assemblies by eliminating the need for a close tolerance fit between the mounting surfaces of the pump and the seals. The liquid metal pump also comprises a shaft support structure that is isolated from the pump housing for better preservation of alignment of shaft bearings. The shaft support structure also allows for complete removal of pump internals for inspection and repair

Levitação acústica

OpenAIRE

Andrade, Marco Aurélio Brizzotti; Pérez, Nicolás; Adamowski, Julio Cezar

2015-01-01

A levitação acústica pode ser uma ferramenta valiosa para auxiliar estudantes de graduação a aprender conceitos básicos de física, tais como movimento harmônico simples, ondas acústicas estacionárias, e energia potencial. Neste artigo, apresentamos o princípio de funcionamento de um levitador acústico e explicamos como aplicar as equações básicas da acústica para determinar a força de radiação acústica que atua numa esfera em uma onda estacionária. Acoustic levitation can be a valuable too...

Approaches to building single-stage AC/AC conversion switch-mode audio power amplifiers

DEFF Research Database (Denmark)

Ljusev, Petar; Andersen, Michael Andreas E.

2004-01-01

This paper discusses the possible topologies and promising approaches towards direct single-phase AC-AC conversion of the mains voltage for audio applications. When compared to standard Class-D switching audio power amplifiers with a separate power supply, it is expected that direct conversion...

Introduction to AC machine design

CERN Document Server

Lipo, Thomas A

2018-01-01

AC electrical machine design is a key skill set for developing competitive electric motors and generators for applications in industry, aerospace, and defense. This book presents a thorough treatment of AC machine design, starting from basic electromagnetic principles and continuing through the various design aspects of an induction machine. Introduction to AC Machine Design includes one chapter each on the design of permanent magnet machines, synchronous machines, and thermal design. It also offers a basic treatment of the use of finite elements to compute the magnetic field within a machine without interfering with the initial comprehension of the core subject matter. Based on the author's notes, as well as after years of classroom instruction, Introduction to AC Machine Design: * Brings to light more advanced principles of machine design--not just the basic principles of AC and DC machine behavior * Introduces electrical machine design to neophytes while also being a resource for experienced designers * ...

Heat pumps

CERN Document Server

Brodowicz, Kazimierz; Wyszynski, M L; Wyszynski

2013-01-01

Heat pumps and related technology are in widespread use in industrial processes and installations. This book presents a unified, comprehensive and systematic treatment of the design and operation of both compression and sorption heat pumps. Heat pump thermodynamics, the choice of working fluid and the characteristics of low temperature heat sources and their application to heat pumps are covered in detail.Economic aspects are discussed and the extensive use of the exergy concept in evaluating performance of heat pumps is a unique feature of the book. The thermodynamic and chemical properties o

Acupuncture Injection Combined with Electrokinetic Injection for Polydimethylsiloxane Microfluidic Devices

Directory of Open Access Journals (Sweden)

Ji Won Ha

2017-01-01

Full Text Available We recently reported acupuncture sample injection that leads to reproducible injection of nL-scale sample segments into a polydimethylsiloxane (PDMS microchannel for microchip capillary electrophoresis. The advantages of the acupuncture injection in microchip capillary electrophoresis include capability of minimizing sample loss and voltage control hardware and capability of introducing sample plugs into any desired position of a microchannel. However, the challenge in the previous study was to achieve reproducible, pL-scale sample injections into PDMS microchannels. In the present study, we introduce an acupuncture injection technique combined with electrokinetic injection (AICEI technique to inject pL-scale sample segments for microchip capillary electrophoresis. We carried out the capillary zone electrophoresis (CZE separation of FITC and fluorescein, and the mixture of 10 μM FITC and 10 μM fluorescein was separated completely by using the AICEI method.

Action of ouabain and an amino-cardenolide on Na+-pump function and contractility of isolated canine heart cells

International Nuclear Information System (INIS)

Porterfield, L.M.; Songu-Mize, E.; Chryssanthis, T.; Caldwell, R.W.

1986-01-01

Viable, rod-shaped, Ca ++ -tolerant cells were isolated from the cardiac ventricle of adult mongrel dogs, a digitalis-sensitive species. These cells do not contract spontaneously but contractions were driven by electrical field stimulation. Changes in contractile amplitude were assessed by computer-assisted analysis of recorded phase contrast images. Addition of a polar aminocardenolide (AC), ASI-222, produced a dose-related increase in contractility with a concentration producing a 50% maximal response (RC 50 ) of 4 x 10 -8 M. For ouabain (OB) the RC 50 was 7 x 10 -7 M. Cellular Na + -pump (NaP) function was determined as digitalis-sensitive 86 Rb + -uptake. Addition of AC and OB to these cells produced a dose-related decrease in 86 Rb + -uptake; concentrations which produced a 50% inhibition (IC 50 ) of NaP function were of 6 x 10 -8 M and 1.2 x 10 -6 M for AC and OB, respectively. Their data indicates that in isolated dog heart cells AC is both a more potent inotropic agent and an inhibitor of NaP function by 15-20 fold than OB. The RC 50 and IC 50 for these processes correlate for each glycoside

Experimental Study on Series Operation of Sliding Vane Pump and Centrifugal Pump

OpenAIRE

Li, Tao; Zhang, Weiming; Jiang, Ming; Li, Zhengyang

2013-01-01

A platform for sliding vane pump and centrifugal pump tests is installed to study the series operation of them under different characteristics of pipeline. Firstly, the sliding vane pump and the centrifugal pump work independently, and the performance is recorded. Then, the two types of pumps are combined together, with the sliding vane pump acting as the feeding pump. Comparison is made between the performance of the independently working pump and the performance of series operation pump. Re...

Centrifugal pump handbook

CERN Document Server

Pumps, Sulzer

2010-01-01

This long-awaited new edition is the complete reference for engineers and designers working on pump design and development or using centrifugal pumps in the field. This authoritative guide has been developed with access to the technical expertise of the leading centrifugal pump developer, Sulzer Pumps. In addition to providing the most comprehensive centrifugal pump theory and design reference with detailed material on cavitation, erosion, selection of materials, rotor vibration behavior and forces acting on pumps, the handbook also covers key pumping applications topics and operational

Electrical Insulation Of Carbon Nanotube Separation Columns For Microchip Electrochromatography

DEFF Research Database (Denmark)

Mogensen, Klaus Bo; Chen, Miaoxiang Max; Mølhave, Kristian

2011-01-01

Carbon nanotubes (CNT) have been grown in microfluidic glass channels for chemical analysis based on electrokinetic separations. A limitation of CNTs for this type of application is their high conductivity, which prevent them from being used for electroosmotic pumping with electrical field streng...

The Effect of the Feedback Controller on Superconducting Tokamak AC Losses + AC-CRPP user manual

International Nuclear Information System (INIS)

Schaerz, B.; Bruzzone, P.; Favez, J.Y.; Lister, J.B.; Zapretilina, E.

2001-11-01

Superconducting coils in a Tokamak are subject to AC losses when the field transverse to the coil current varies. A simple model to evaluate the AC losses has been derived and benchmarked against a complete model used in the ITER design procedure. The influence of the feedback control strategy on the AC losses is examined using this model. An improved controller is proposed, based on this study. (author)

AcMNPV ac143 (odv-e18) is essential for mediating budded virus production and is the 30th baculovirus core gene

International Nuclear Information System (INIS)

McCarthy, Christina B.; Theilmann, David A.

2008-01-01

Autographa californica multiple nucleopolyhedrovirus (AcMNPV) ac143 (odv-e18) is a late gene that encodes for a predicted 9.6 kDa structural protein that locates to the occlusion derived viral envelope and viral induced intranuclear microvesicles [Braunagel, S.C., He, H., Ramamurthy, P., and Summers, M.D. (1996). Transcription, translation, and cellular localization of three Autographa californica nuclear polyhedrosis virus structural proteins: ODV-E18, ODV-E35, and ODV-EC27. Virology 222, 100-114.]. In this study we demonstrate that ac143 is actually a previously unrecognized core gene and that it is essential for mediating budded virus production. To examine the role of ac143 in the baculovirus life cycle, we used the AcMNPV bacmid system to generate an ac143 knockout (KO) virus (AcBAC ac142REP-ac143KO ). Fluorescence and light microscopy showed that infection by AcBAC ac142REP-ac143KO is limited to a single cell and titration assays confirmed that AcBAC ac142REP-ac143KO was unable to produce budded virus (BV). Progression to very late phases of the viral infection was evidenced by the development of occlusion bodies in the nuclei of transfected cells. This correlated with the fact that viral DNA replication was unaffected in AcBAC ac142REP-ac143KO transfected cells. The entire ac143 promoter, which includes three late promoter motifs, is contained within the ac142 open reading frame. Different deletion mutants of this region showed that the integrity of the ac142-ac143 core gene cluster was required for the bacmids to display wild-type patterns of viral replication, BV production and RNA transcription

Penis Pump

Science.gov (United States)

... your appointment might be less involved. Choosing a penis pump Some penis pumps are available without a ... it doesn't get caught in the ring. Penis pumps for penis enlargement Many advertisements in magazines ...

Pumping characteristics of sputter ion pump (SIP) and titanium sublimation pump (TSP) combination

International Nuclear Information System (INIS)

Ratnakala, K.C.; Patel, R.J.; Bhavsar, S.T.; Pandiyar, M.L.; Ramamurthi, S.S.

1995-01-01

For achieving hydrocarbon free, clean ultra high vacuum, SIP-TSP combination is one of the ideal choice for pumping. For the SRS facility in Centre for Advanced Technology (CAT), we are utilising this combination, enmass. For this purpose, two modules of these combination set-ups are assembled, one with the TSP as an integral part of SIP and the other, with TSP as a separate pump mounted on the top of SIP. The pump bodies were vacuum degassed at 700 degC at 10 -5 mbar for 3 hrs. An ultimate vacuum of 3 x 10 -11 mbar was achieved, after a bake-out at 250 degC for 4 hrs, followed by continuous SIP pumping for 48 hrs, with two TSP flashing at approximately 10 hrs interval. The pump-down patterns as well as the pressure-rise patterns are studied. (author). 2 refs., 5 figs

Microfluidic device and methods for focusing fluid streams using electroosmotically induced pressures

Science.gov (United States)

Jacobson, Stephen C.; Ramsey, J. Michael

2010-06-01

A microfabricated device employing a bridging membrane and methods for electrokinetic transport of a liquid phase biological or chemical material using the same are described. The bridging membrane is deployed in or adjacent to a microchannel and permits either electric current flow or the transport of gas species, while inhibiting the bulk flow of material. The use of bridging membranes in accordance with this invention is applicable to electrokinetically inducing fluid flow to confine a selected material in a region of a microchannel that is not influenced by an electric field. Other structures for inducing fluid flow in accordance with this invention include nanochannel bridging membranes and alternating current fluid pumping devices. Applications of the bridging membranes according to this invention include the separation of species from a sample material, valving of fluids in a microchannel network, mixing of different materials in a microchannel, and the pumping of fluids.

Innovative application of AC-voltammetry in the characterization of oxides nanolayers formed on metals, under the effect of AC-perturbations

Energy Technology Data Exchange (ETDEWEB)

Bueno, V.; Lazzari, L.; Ormellesse, M. [Politecnico di Milano, Milan (Italy). Dept. of Chemistry, Materials and Chemical Engineering; Spinelli, P. [Politecnico di Torino, Torino (Italy). Dept. of Materials Science and Chemical Engineering

2008-07-01

Stray AC-currents have been reported to cause many cases of unwanted corrosion on metallic structures. This study characterized the formation and stability of the surface oxide film formed on mild steel under the effect of AC voltage in a very basic environment. The response of the system to DC signals was examined, along with its reversibility to AC perturbations. SEM analysis was used to complement AC-Voltammetry. Reaction mechanisms responsible for the AC-corrosion were formulated. AC-Voltammetry involves the application of a controlled sinusoidal voltage onto a solid working electrode while it is being swept in a DC-voltage range, with the faradaic or capacitative components of the resulting AC-current being recorded. The innovative aspect is the application of AC-V to characterize its nano-surface while it is being affected by AC-signals. It was concluded that the AC-V can be useful for the study of redox processes occurring at the surface of a reactive electrode and for the application of a considerable AC perturbation to the electrode in a potentiostatically controlled way. According to the electrochemistry of the double layer, there are 3 main reactions in the NaOH 1M media that are not reversible to DC nor to AC perturbations in the range of cathodic protection of mild steel. When designing metallic systems susceptible to stray currents, the AC-V could quantify the final faradaic, resistive and capacitative responses. 6 refs., 1 fig.

On Developing Field-Effect-Tunable Nanofluidic Ion Diodes with Bipolar, Induced-Charge Electrokinetics

Directory of Open Access Journals (Sweden)

Ye Tao

2018-04-01

Full Text Available We introduce herein the induced-charge electrokinetic phenomenon to nanometer fluidic systems; the design of the nanofluidic ion diode for field-effect ionic current control of the nanometer dimension is developed by enhancing internal ion concentration polarization through electrochemical transport of inhomogeneous inducing-counterions resulting from double gate terminals mounted on top of a thin dielectric layer, which covers the nanochannel connected to microfluidic reservoirs on both sides. A mathematical model based on the fully-coupled Poisson-Nernst-Plank-Navier-Stokes equations is developed to study the feasibility of this structural configuration causing effective ionic current rectification. The effect of various physiochemical and geometrical parameters, such as the native surface charge density on the nanochannel sidewalls, the number of gate electrodes (GE, the gate voltage magnitude, and the solution conductivity, permittivity, and thickness of the dielectric coating, as well as the size and position of the GE pair of opposite gate polarity, on the resulted rectification performance of the presented nanoscale ionic device is numerically analyzed by using a commercial software package, COMSOL Multiphysics (version 5.2. Three types of electrohydrodynamic flow, including electroosmosis of 1st kind, induced-charge electroosmosis, and electroosmosis of 2nd kind that were originated by the Coulomb force within three distinct charge layers coexist in the micro/nanofluidic hybrid network and are shown to simultaneously influence the output current flux in a complex manner. The rectification factor of a contrast between the ‘on’ and ‘off’ working states can even exceed one thousand-fold in the case of choosing a suitable combination of several key parameters. Our demonstration of field-effect-tunable nanofluidic ion diodes of double external gate electrodes proves invaluable for the construction of a flexible electrokinetic platform

High voltage AC/AC electrochemical capacitor operating at low temperature in salt aqueous electrolyte

Science.gov (United States)

Abbas, Qamar; Béguin, François

2016-06-01

We demonstrate that an activated carbon (AC)-based electrochemical capacitor implementing aqueous lithium sulfate electrolyte in 7:3 vol:vol water/methanol mixture can operate down to -40 °C with good electrochemical performance. Three-electrode cell investigations show that the faradaic contributions related with hydrogen chemisorption in the negative AC electrode are thermodynamically unfavored at -40 °C, enabling the system to work as a typical electrical double-layer (EDL) capacitor. After prolonged floating of the AC/AC capacitor at 1.6 V and -40°C, the capacitance, equivalent series resistance and efficiency remain constant, demonstrating the absence of ageing related with side redox reactions at this temperature. Interestingly, when temperature is increased back to 24 °C, the redox behavior due to hydrogen storage reappears and the system behaves as a freshly prepared one.

AcEST: DK954361 [AcEST

Lifescience Database Archive (English)

Full Text Available in 5-4 OS=Homo sap... 33 1.1 sp|Q9DBY1|SYVN1_MOUSE E3 ubiquitin-protein ligase synoviolin OS=... 33 1.4 sp|Q...86TM6|SYVN1_HUMAN E3 ubiquitin-protein ligase synoviolin OS=... 33 1.4 sp|O55188|DMP1_MOUSE Dentin matrix ac

21 CFR 886.4440 - AC-powered magnet.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false AC-powered magnet. 886.4440 Section 886.4440 Food... DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4440 AC-powered magnet. (a) Identification. An AC-powered magnet is an AC-powered device that generates a magnetic field intended to find and remove...

Scale-up of the electrokinetic fence technology for the removal of pesticides. Part II: Does size matter for removal of herbicides?

Science.gov (United States)

López-Vizcaíno, R; Risco, C; Isidro, J; Rodrigo, S; Saez, C; Cañizares, P; Navarro, V; Rodrigo, M A

2017-01-01

This work reports results of the application of electrokinetic fence technology in a 32 m 3 -prototype which contains soil polluted with 2,4-D and oxyfluorfen, focusing on the evaluation of the mechanisms that describe the removal of these two herbicides and comparing results to those obtained in smaller plants: a pilot-scale mockup (175 L) and a lab-scale soil column (1 L). Results show that electric heating of soil (coupled with the increase in the volatility) is the key to explain the removal of pollutants in the largest scale facility while electrokinetic transport processes are the primary mechanisms that explain the removal of herbicides in the lab-scale plant. 2-D and 3-D maps of the temperature and pollutant concentrations are used in the discussion of results trying to give light about the mechanisms and about how the size of the setup can lead to different conclusions, despite the same processes are occurring in the soil. Copyright © 2016 Elsevier Ltd. All rights reserved.

Surfactant-free microemulsion electrokinetic chromatography (SF-MEEKC) with UV and MS detection - a novel approach for the separation and ESI-MS detection of neutral compounds.

Science.gov (United States)

Mohorič, Urška; Beutner, Andrea; Krickl, Sebastian; Touraud, Didier; Kunz, Werner; Matysik, Frank-Michael

2016-12-01

Microemulsion electrokinetic chromatography (MEEKC) is a powerful tool to separate neutral species based on differences in their hydrophobic and hydrophilic properties. However, as a major drawback the conventionally used SDS based microemulsions are not compatible with electrospray ionization mass spectrometry (ESI-MS). In this work, a surfactant-free microemulsion (SFME) consisting of water, ethanol, and 1-octanol is used for surfactant-free microemulsion electrokinetic chromatography (SF-MEEKC). Ammonium acetate was added to the SFME enabling electrophoretic separations. The stability of SFMEs containing ammonium acetate was investigated using small-angle X-ray scattering and dynamic light scattering. A method for the separation of a model system of hydrophobic and hydrophilic neutral vitamins, namely the vitamins B 2 and D 3 , and the cationic vitamin B 1 was developed using UV/VIS detection. The influence of the ammonium acetate concentration on the separation performance was studied in detail. The method was characterized concerning reproducibility of migration times and peak areas and concerning the linearity of the calibration data. Furthermore, SF-MEEKC was coupled to ESI-MS investigating the compatibility between SFMEs and the ESI process. The signal intensities of ESI-MS measurements of the model analytes were comparable for SFMEs and aqueous systems. Finally, the vitamin D 3 content of a drug treating vitamin D 3 deficiency was determined by SF-MEEKC coupled to ESI-MS using 25-hydroxycholecalciferol as an internal standard. Graphical abstract The concept of surfactant-free microemulsion electrokinetic chromatography coupled to electrospray ionization mass spectrometry.

Removal of heavy metals from kaolin using an upward electrokinetic soil remedial (UESR) technology

International Nuclear Information System (INIS)

Wang, J.-Y.; Huang, X.-J.; Kao, Jimmy C.M.; Stabnikova, Olena

2006-01-01

An upward electrokinetic soil remedial (UESR) technology was proposed to remove heavy metals from contaminated kaolin. Unlike conventional electrokinetic treatment that uses boreholes or trenches for horizontal migration of heavy metals, the UESR technology, applying vertical non-uniform electric fields, caused upward transportation of heavy metals to the top surface of the treated soil. The effects of current density, treatment duration, cell diameter, and different cathode chamber influent (distilled water or 0.01 M nitric acid) were studied. The removal efficiencies of heavy metals positively correlated to current density and treatment duration. Higher heavy metals removal efficiency was observed for the reactor cell with smaller diameter. A substantial amount of heavy metals was accumulated in the nearest to cathode 2 cm layer of kaolin when distilled water was continuously supplied to the cathode chamber. Heavy metals accumulated in this layer of kaolin can be easily excavated and disposed off. The main part of the removed heavy metals was dissolved in cathode chamber influent and moved away with cathode chamber effluent when 0.01 M nitric acid was used, instead of distilled water. Energy saving treatment by UESR technology with highest metal removal efficiencies was provided by two regimes: (1) by application of 0.01 M nitric acid as cathode chamber influent, cell diameter of 100 mm, duration of 18 days, and constant voltage of 3.5 V (19.7 kWh/m 3 of kaolin) and (2) by application of 0.01 M nitric acid as cathode chamber influent, cell diameter of 100 cm, duration of 6 days, and constant current density of 0.191 mA/cm 2 (19.1 kWh/m 3 of kaolin)

Electrokinetic transport behavior of phenol in upper Permian soils

Energy Technology Data Exchange (ETDEWEB)

Haus, R.; Zorn, R.; Czurda, K.; Ruthe, H. [Dept. of Applied Geology, Univ. Karlsruhe (Germany)

2001-07-01

Electrokinetic experiments with upper Permian, phenol contaminated soils ('Solaris'-area Chemnitz) were performed. Bench scale results show the successful removal of phenol. The developing soil-pH during electroremediation tests is found to affect the transport behavior of phenol strongly. If buffer solutions are used at the electrode compartments, phenol could be removed from the soils. By neutralizing the generating hydrogen ions at the anode reservoir the hydroxyl ions developing at the cathode by the electrolysis of water enter the soil and propagate to the anode by increasing the soil pH. The pH dependent dehydroxylation of phenol promotes the electromigration of negative charged phenolate ions from the cathode to the anode. At the anode the coupling of phenoxyl-radicals supports the formation of non toxic, water insoluble polyoxyphenylene by electro-polymerization. In the case of buffering the pH at the cathode uncharged phenol is transported by electroosmosis from the anode to the cathode because of the nonexisting base front and the unhindered production of hydrogen ions at the anode. (orig.)

Fabrication of Micromixers Utilizing Shedding Effect Induced by Electrokinetic Instability

International Nuclear Information System (INIS)

Fu, L-M; Tai, C-H; Tsai, C-H; Lin, C-H; Lee, C-Y

2006-01-01

This paper proposes a T-shaped micromixer featuring 45 deg. parallelogram barriers within the mixing channel. The proposed device obtains a rapid mixing of two sample fluids by means of the electrokinetic instability induced by shedding effect which is produced as an appropriate intensity of DC electric field of is applied. The proposed device uses a single high-voltage power source to simultaneously drive and mix the sample fluids. The effectiveness of the mixer is characterized experimentally as a function of the applied electrical field intensity and the extent to which the parallelogram barriers obstruct the mixing channel. The experimental results indicate that the mixing performance reaches 91.2% at a cross-section located 2.3 mm downstream of the T-junction when the barriers obstruct four-fifths of the channel width and an electrical field of 300V/cm is applied. The micromixing method presented in this study provides a simple low-cost solution to mixing problems in lab-on-a-chip systems

Centrifugal pumps

CERN Document Server

Gülich, Johann Friedrich

2014-01-01

This book gives an unparalleled, up-to-date, in-depth treatment of all kinds of flow phenomena encountered in centrifugal pumps including the complex interactions of fluid flow with vibrations and wear of materials. The scope includes all aspects of hydraulic design, 3D-flow phenomena and partload operation, cavitation, numerical flow calculations, hydraulic forces, pressure pulsations, noise, pump vibrations (notably bearing housing vibration diagnostics and remedies), pipe vibrations, pump characteristics and pump operation, design of intake structures, the effects of highly viscous flows, pumping of gas-liquid mixtures, hydraulic transport of solids, fatigue damage to impellers or diffusers, material selection under the aspects of fatigue, corrosion, erosion-corrosion or hydro-abrasive wear, pump selection, and hydraulic quality criteria. As a novelty, the 3rd ed. brings a fully analytical design method for radial impellers, which eliminates the arbitrary choices inherent to former design procedures. The d...

Pumping characteristics of roots blower pumps for light element gases

International Nuclear Information System (INIS)

Hiroki, Seiji; Abe, Tetsuya; Tanzawa, Sadamitsu; Nakamura, Jun-ichi; Ohbayashi, Tetsuro

2002-07-01

The pumping speed and compression ratio of the two-stage roots blower pumping system were measured for light element gases (H 2 , D 2 and He) and for N 2 , in order to assess validity of the ITER torus roughing system as an ITER R and D task (T234). The pumping system of an Edwards EH1200 (nominal pumping speed of 1200 m 3 /s), two EH250s (ibid. 250 m 3 /s) and a backing pump (ibid. 100 m 3 /s) in series connection was tested under PNEUROP standards. The maximum pumping speeds of the two-stage system for D 2 and N 2 were 1200 and 1300 m 3 /h, respectively at 60 Hz, which satisfied the nominal pumping speed. These experimental data support the design validity of the ITER torus roughing system. (author)

PUMPS

Science.gov (United States)

Thornton, J.D.

1959-03-24

A pump is described for conveving liquids, particure it is not advisable he apparatus. The to be submerged in the liquid to be pumped, a conduit extending from the high-velocity nozzle of the injector,and means for applying a pulsating prcesure to the surface of the liquid in the conduit, whereby the surface oscillates between positions in the conduit. During the positive half- cycle of an applied pulse liquid is forced through the high velocity nozzle or jet of the injector and operates in the manner of the well known water injector and pumps liquid from the main intake to the outlet of the injector. During the negative half-cycle of the pulse liquid flows in reverse through the jet but no reverse pumping action takes place.

Electrokinetic soil decontamination - summary of results of various studies in laboratory, bench-scale and field

Energy Technology Data Exchange (ETDEWEB)

Kutschan, B.; Wutzler, R.; Goldmann, T. [INTUS Inst. fuer Technologie und Umweltschutz e.V., Berlin (Germany)

2001-07-01

In electroremediation, contaminants are removed form soil and groundwater by the action of an electric potential applied across electrodes embedded in the contaminated medium. Driving the remediation are the electrokinetic phenomena of electro-osmosis, ion migration and electrophoresis. Other common physicochemical phenomena that are also present are diffusion, chemical reactions, hydrolysis (change of pH-value), ion exchange, complexation and others. The complex interactions between all these phenomena determine the processes. Important process parameters are transition rates, bulk liquid velocity, {zeta}-potential (Helmholtz-Smoluchowski-equation) and others. Some parameters are determined at laboratory-, bench- and field scale. (orig.)

Pump characteristics and applications

CERN Document Server

Volk, Michael

2013-01-01

Providing a wealth of information on pumps and pump systems, Pump Characteristics and Applications, Third Edition details how pump equipment is selected, sized, operated, maintained, and repaired. The book identifies the key components of pumps and pump accessories, introduces the basics of pump and system hydraulics as well as more advanced hydraulic topics, and details various pump types, as well as special materials on seals, motors, variable frequency drives, and other pump-related subjects. It uses example problems throughout the text, reinforcing the practical application of the formulae

Pump element for a tube pump

DEFF Research Database (Denmark)

2011-01-01

The invention relates to a tube pump comprising a tube and a pump element inserted in the tube, where the pump element comprises a rod element and a first and a second non-return valve member positioned a distance apart on the rod element. The valve members are oriented in the same direction...... relative to the rod element so as to allow for a fluid flow in the tube through the first valve member, along the rod element, and through the second valve member. The tube comprises an at least partly flexible tube portion between the valve members such that a repeated deformation of the flexible tube...... portion acts to alternately close and open the valve members thereby generating a fluid flow through the tube. The invention further relates to a pump element comprising at least two non-return valve members connected by a rod element, and for insertion in an at least partly flexible tube in such tube...

Pumping behavior of sputtering ion pump

Energy Technology Data Exchange (ETDEWEB)

Chou, T.S.; Bittner, J.; Schuchman, J.

1991-12-31

To optimize the design of a distributed ion pump (DIP) for the Superconducting X-Ray Lithography Source (SXLS) the stability of the rotating electron cloud at very high magnetic field beyond transition, must be re-examined. In this work the pumping speed and frequency spectrum of a DIP at various voltages (1 to 10 KV) and various magnetic fields (0.1 to 4 Tesla) are measured. Three cell diameters 10 mm, 5 mm and 2.5 mm, each 8 mm long, and with 3 or 4 mm gaps between anode and cathode are investigated. In this study both the titanium cathodes and the stainless steel anode plates are perforated with holes comparable in size to the anode cell diameters. Only the partially saturated pumping behavior is under investigation. The ultimate pressure and conditioning of the pump will be investigated at a later date when the stability criterion for the electron cloud is better understood.

Pumping behavior of sputtering ion pump

Energy Technology Data Exchange (ETDEWEB)

Chou, T.S.; Bittner, J.; Schuchman, J.

1991-01-01

To optimize the design of a distributed ion pump (DIP) for the Superconducting X-Ray Lithography Source (SXLS) the stability of the rotating electron cloud at very high magnetic field beyond transition, must be re-examined. In this work the pumping speed and frequency spectrum of a DIP at various voltages (1 to 10 KV) and various magnetic fields (0.1 to 4 Tesla) are measured. Three cell diameters 10 mm, 5 mm and 2.5 mm, each 8 mm long, and with 3 or 4 mm gaps between anode and cathode are investigated. In this study both the titanium cathodes and the stainless steel anode plates are perforated with holes comparable in size to the anode cell diameters. Only the partially saturated pumping behavior is under investigation. The ultimate pressure and conditioning of the pump will be investigated at a later date when the stability criterion for the electron cloud is better understood.

Multiple pump housing

Science.gov (United States)

Donoho, II, Michael R.; Elliott; Christopher M.

2010-03-23

A fluid delivery system includes a first pump having a first drive assembly, a second pump having a second drive assembly, and a pump housing. At least a portion of each of the first and second pumps are located in the housing.

Assessing the energy efficiency of pumps and pump units background and methodology

CERN Document Server

Bernd Stoffel, em Dr-Ing

2015-01-01

Assessing the Energy Efficiency of Pumps and Pump Units, developed in cooperation with Europump, is the first book available providing the background, methodology, and assessment tools for understanding and calculating energy efficiency for pumps and extended products (pumps+motors+drives). Responding to new EU requirements for pump efficiency, and US DOE exploratory work in setting pump energy efficiency guidelines, this book provides explanation, derivation, and illustration of PA and EPA methods for assessing energy efficiency. It surveys legislation related to pump energy eff

Environmental Electrokinetics for a sustainable subsurface

DEFF Research Database (Denmark)

Lima, A.T.; Hofmann, A.; Reynolds, D.R.

2017-01-01

notably using zero-valent iron [ZVI]), enhanced in-situ bioremediation (EISB), phytoremediation, soil-washing, pump-and-treat, soil vapour extraction (SVE), thermal treatment, and excavation and disposal. Decades of field applications have shown that these techniques can successfully treat or control...

Electrokinetic decontamination of concrete. Final report, August 3, 1993 - September 15, 1996

International Nuclear Information System (INIS)

1998-01-01

The ELECTROSORB reg-sign open-quotes Cclose quotes process is an electrokinetic process for decontaminating concrete. ELECTROSORB reg-sign open-quotes Cclose quotes uses a carpet-like extraction pad which is placed on the contaminated concrete surface. An electrolyte solution is circulated from a supporting module. This module keeps the electrolyte solution clean. The work is advancing through the engineering development stage with steady progress toward a full scale demonstration unit which will be ready for incorporation in the DOE Large Scale Demonstration Program by Summer 1997. A demonstration was carried out at the Mound Facility in Miamisburg, Ohio, in June 1996. Third party verification by EG ampersand G verified the effectiveness of the process. Results of this work and the development work that proceeded are described herein

Effect of Non-linear Velocity Loss Changes in Pumping Stage of Hydraulic Ram Pumps on Pumping Discharge Rate

Directory of Open Access Journals (Sweden)

Reza Fatahialkouhi

2018-03-01

Full Text Available The ram pump is a device which pumps a portion of input discharge to the pumping system in a significant height by using renewable energy of water hammer. The complexities of flow hydraulic on one hand and on the other hand the use of simplifying assumptions in ram pumps have caused errors in submitted analytical models for analyzing running cycle of these pumps. In this study it has been tried to modify the governing analytical model on hydraulic performance of these pumps in pumping stage. In this study by creating a logical division, the cycle of the ram pump was divided into three stages of acceleration, pumping and recoil and the governing equations on each stage of cycling are presented by using method of characteristics. Since the closing of impulse valve is nonlinear, velocity loss in pumping stage is considered nonlinearly. Also the governing equations in pumping stage were modified by considering disc elasticity of impulse valve and changing volume of the pump body when the water hammer phenomenon is occurred. In order to evaluate results and determine empirical factors of the proposed analytical model, a physical model of the ram pump is made with internal diameter of 51 mm. Results of this study are divided into several parts. In the first part, loss coefficients of the impulse valve were measured experimentally and empirical equations of drag coefficient and friction coefficient of the impulse valve were submitted by using nonlinear regression. In the second part, results were evaluated by using experimental data taken from this study. Evaluation of statistical error functions showed that the proposed model has good accuracy for predicting experimental observations. In the third part, in order to validate the results in pumping stage, the analytical models of Lansford and Dugan (1941 and Tacke (1988 were used and the error functions resulted from prediction of experimental observations were investigated through analytical models of

Simultaneous distribution of AC and DC power

Science.gov (United States)

Polese, Luigi Gentile

2015-09-15

A system and method for the transport and distribution of both AC (alternating current) power and DC (direct current) power over wiring infrastructure normally used for distributing AC power only, for example, residential and/or commercial buildings' electrical wires is disclosed and taught. The system and method permits the combining of AC and DC power sources and the simultaneous distribution of the resulting power over the same wiring. At the utilization site a complementary device permits the separation of the DC power from the AC power and their reconstruction, for use in conventional AC-only and DC-only devices.

Isolation of MA-ACS Gene Family and Expression Study of MA-ACS1 Gene in Musa acuminata Cultivar Pisang Ambon Lumut

Directory of Open Access Journals (Sweden)

LISTYA UTAMI KARMAWAN

2009-03-01

Full Text Available Musa acuminata cultivar pisang ambon lumut is a native climacteric fruit from Indonesia. Climacteric fruit ripening process is triggered by the gaseous plant hormone ethylene. The rate limiting enzyme involved in ethylene biosynthesis is ACC synthase (ACS which is encoded by ACS gene family. The objective of this study is to identify MA-ACS gene family in M. acuminata cultivar pisang ambon lumut and to study the MA-ACS1 gene expression. The result showed that there were nine M. acuminata ACS gene family members called MA-ACS1–9. Two of them (MA-ACS1 and MA-ACS2 were assessed using reverse transcriptase PCR (RT-PCR for gene expression study and it was only MA-ACS1 correlated with fruit ripening. The MA-ACS1 gene fragment has been successfully isolated and characterized and it has three introns, four exons, and one stop codon. It also shows highest homology with MACS1 gene from M. acuminata cultivar Hsian Jien Chiao (GenBank accession number AF056164. Expression analysis of MA-ACS1 using quantitative PCR (qPCR showed that MA-ACS1 gene expression increased significantly in the third day, reached maximum at the fifth day, and then decreased in the seventh day after harvesting. The qPCR expression analysis result correlated with the result of physical analysis during fruit ripening.

Universality of ac conduction in disordered solids

DEFF Research Database (Denmark)

Dyre, Jeppe; Schrøder, Thomas

2000-01-01

The striking similarity of ac conduction in quite different disordered solids is discussed in terms of experimental results, modeling, and computer simulations. After giving an overview of experiment, a macroscopic and a microscopic model are reviewed. For both models the normalized ac conductivity...... as a function of a suitably scaled frequency becomes independent of details of the disorder in the extreme disorder limit, i.e., when the local randomly varying mobilities cover many orders of magnitude. The two universal ac conductivities are similar, but not identical; both are examples of unusual non......-power-law universalities. It is argued that ac universality reflects an underlying percolation determining dc as well as ac conductivity in the extreme disorder limit. Three analytical approximations to the universal ac conductivities are presented and compared to computer simulations. Finally, model predictions...

Power converter with maximum power point tracking MPPT for small wind-electric pumping systems

International Nuclear Information System (INIS)

Lara, David; Merino, Gabriel; Salazar, Lautaro

2015-01-01

Highlights: • We implement a wind electric pumping system of small power. • The power converter allowed to change the operating point of the electro pump. • Two control techniques were implemented in the power converter. • The control V/f variable allowed to increase the power generated by the permanent magnet generator. - Abstract: In this work, an AC–DC–AC direct-drive power converter was implemented for a wind electric pumping system consisting of a permanent magnet generator (PMG) of 1.3 kW and a peripheral single phase pump of 0.74 kW. In addition, the inverter linear V/f control scheme and the maximum power point tracking (MPPT) algorithm with variable V/f were developed. MPPT algorithm seeks to extract water in a wide range of power input using the maximum amount of wind power available. Experimental trials at different pump pressures were conducted. With a MPPT tracking system with variable V/f, a power value of 1.3 kW was obtained at a speed of 350 rpm and a maximum operating hydraulic head of 50 m. At lower operating heads pressures (between 10 and 40 m), variable V/f control increases the power generated by the PMG compared to the linear V/f control. This increase ranged between 4% and 23% depending on the operating pressure, with an average of 13%, getting close to the maximum electrical power curve of the PMG. The pump was driven at variable frequency reaching a minimum speed of 0.5 times the rated speed. Efficiency of the power converter ranges between 70% and 95% with a power factor between 0.4 and 0.85, depending on the operating pressure

Performance Analysis Of Single-Pumped And Dual-Pumped Parametric Optical Amplifier

Directory of Open Access Journals (Sweden)

Sandar Myint

2015-06-01

Full Text Available Abstract In this study we present a performance analysis of single-pumped and dual- pumped parametric optical amplifier and present the analysis of gain flatness in dual- pumped Fiber Optical Parametric Amplifier FOPA based on four-wave mixing FWM. Result shows that changing the signal power and pump power give the various gains in FOPA. It is also found out that the parametric gain increase with increase in pump power and decrease in signal power. .Moreover in this paper the phase matching condition in FWM plays a vital role in predicting the gain profile of the FOPAbecause the parametric gain is maximum when the total phase mismatch is zero.In this paper single-pumped parametric amplification over a 50nm gain bandwidth is demonstrated using 500 nm highly nonlinear fiber HNLF and signal achieves about 31dB gain. For dual-pumped parametric amplification signal achieves 26.5dB gains over a 50nm gain bandwidth. Therefore dual-pumped parametric amplifier can provide relatively flat gain over a much wider bandwidth than the single-pumped FOPA.

Cardiovascular outcomes associated with concomitant use of clopidogrel and proton pump inhibitors in patients with acute coronary syndrome in Taiwan

Science.gov (United States)

Lin, Chen-Fang; Shen, Li-Jiuan; Wu, Fe-Lin Lin; Bai, Chyi-Huey; Gau, Churn-Shiouh

2012-01-01

AIMS Our study aimed to examine the impact of concomitant use of proton pump inhibitors (PPIs) with clopidogrel on the cardiovascular outcomes of patients with acute coronary syndrome (ACS). Furthermore, we sought to quantify the effects of five individual PPIs when used concomitantly with clopidogrel. METHODS We conducted a retrospective cohort study of patients who were newly hospitalized for ACS between 1 January 2006 and 31 December 2007 retrieved from the Taiwan National Health Insurance Research Database (NHIRD) and who were prescribed clopidogrel (n= 37 099) during the follow-up period. A propensity score technique was used to establish a matched cohort in 1:1 ratio (n= 5173 for each group). The primary clinical outcome was rehospitalization for ACS, while secondary outcomes were rehospitalization for percutaneous transluminal coronary angioplasty (PTCA) with stent, PTCA without stent and revascularization (PTCA or coronary artery bypass graft surgery) after the discharge date for the index ACS event. RESULTS The adjusted hazard ratio of rehospitalization for ACS was 1.052 (95% confidence interval, 0.971–1.139; P= 0.214) in the propensity score matched cohort. Among all PPIs, only omeprazole was found to be statistically significantly associated with an increased risk of rehospitalization for ACS (adjusted hazard ratio, 1.226; 95% confidence interval, 1.066–1.410; P= 0.004). Concomitant use of esomeprazole, pantoprazole, rabeprazole and lansoprazole did not increase the risk. CONCLUSIONS Our study indicated no statistically significant increase in the risk of rehospitalization for ACS due to concurrent use of clopidogrel and PPIs overall. Among individual PPIs, only omeprazole was found to be statistically significantly associated with increased risk of rehospitalization for ACS. PMID:22364155

Residual heat removal pump and low pressure safety injection pump retrofit program

International Nuclear Information System (INIS)

Dudiak, J.G.; McKenna, J.M.

1992-01-01

Residual Heat Removal (RHR) and low pressure safety injection (LPSI) pumps installed in pressurized water-to-reactor power plants are used to provide low-head safety injection in the event of loss of coolant in the reactor coolant system. Because these pumps are subjected to rather severe temperature and pressure transients, the majority of pumps installed in the RHR service are vertical pumps with a single stage impeller. Typically the pump impeller is mounted on an extended motor shaft (close-coupled configuration) and a mechanical seal is employed at the pump end of the shaft. Traditionally RHR and LPSI pumps have been a significant maintenance item for many utilities. Periodic mechanical seal of motor bearing replacement often is considered routine maintenance. The closed-coupled pump design requires disassembly of the casing cover from the lower pump casing while performing these routine maintenance tasks. This paper introduces a design modification developed to convert the close-coupled RHR and LPSI pumps to a coupled configuration

Gene delivery by microfluidic flow-through electroporation based on constant DC and AC field.

Science.gov (United States)

Geng, Tao; Zhan, Yihong; Lu, Chang

2012-01-01

Electroporation is one of the most widely used physical methods to deliver exogenous nucleic acids into cells with high efficiency and low toxicity. Conventional electroporation systems typically require expensive pulse generators to provide short electrical pulses at high voltage. In this work, we demonstrate a flow-through electroporation method for continuous transfection of cells based on disposable chips, a syringe pump, and a low-cost power supply that provides a constant voltage. We successfully transfect cells using either DC or AC voltage with high flow rates (ranging from 40 µl/min to 20 ml/min) and high efficiency (up to 75%). We also enable the entire cell membrane to be uniformly permeabilized and dramatically improve gene delivery by inducing complex migrations of cells during the flow.

Integrated electrokinetics-adsorption remediation of saline-sodic soils: effects of voltage gradient and contaminant concentration on soil electrical conductivity.

Science.gov (United States)

Essa, Mohammed Hussain; Mu'azu, Nuhu Dalhat; Lukman, Salihu; Bukhari, Alaadin

2013-01-01

In this study, an integrated in situ remediation technique which couples electrokinetics with adsorption, using locally produced granular activated carbon from date palm pits in the treatment zones that are installed directly to bracket the contaminated soils at bench-scale, is investigated. Natural saline-sodic clay soil, spiked with contaminant mixture (kerosene, phenol, Cr, Cd, Cu, Zn, Pb, and Hg), was used in this study to investigate the effects of voltage gradient, initial contaminant concentration, and polarity reversal rate on the soil electrical conductivity. Box-Behnken Design (BBD) was used for the experimental design and response surface methodology (RSM) was employed to model, optimize, and interpret the results obtained using Design-Expert version 8 platform. The total number of experiments conducted was 15 with voltage gradient, polarity reversal rate, and initial contaminant concentration as variables. The main target response discussed in this paper is the soil electrical conductivity due to its importance in electrokinetic remediation process. Responses obtained were fitted to quadratic models whose R (2) ranges from 84.66% to 99.19% with insignificant lack of fit in each case. Among the investigated factors, voltage gradient and initial contaminant concentration were found to be the most significant influential factors.

Integrated Electrokinetics-Adsorption Remediation of Saline-Sodic Soils: Effects of Voltage Gradient and Contaminant Concentration on Soil Electrical Conductivity

Directory of Open Access Journals (Sweden)

Mohammed Hussain Essa

2013-01-01

Full Text Available In this study, an integrated in situ remediation technique which couples electrokinetics with adsorption, using locally produced granular activated carbon from date palm pits in the treatment zones that are installed directly to bracket the contaminated soils at bench-scale, is investigated. Natural saline-sodic clay soil, spiked with contaminant mixture (kerosene, phenol, Cr, Cd, Cu, Zn, Pb, and Hg, was used in this study to investigate the effects of voltage gradient, initial contaminant concentration, and polarity reversal rate on the soil electrical conductivity. Box-Behnken Design (BBD was used for the experimental design and response surface methodology (RSM was employed to model, optimize, and interpret the results obtained using Design-Expert version 8 platform. The total number of experiments conducted was 15 with voltage gradient, polarity reversal rate, and initial contaminant concentration as variables. The main target response discussed in this paper is the soil electrical conductivity due to its importance in electrokinetic remediation process. Responses obtained were fitted to quadratic models whose R2 ranges from 84.66% to 99.19% with insignificant lack of fit in each case. Among the investigated factors, voltage gradient and initial contaminant concentration were found to be the most significant influential factors.

Selective micellar electrokinetic chromatographic method for simultaneous determination of some pharmaceutical binary mixtures containing non-steroidal anti-inflammatory drugs

Directory of Open Access Journals (Sweden)

Michael E. El-Kommos

2013-02-01

Full Text Available A simple and selective micellar electrokinetic chromatographic (MEKC method has been developed for the analysis of five pharmaceutical binary mixtures containing three non-steroidal anti-inflammatory drugs (NSAIDs. The investigated mixtures were Ibuprofen (IP–Paracetamol (PC, Ibuprofen (IP–Chlorzoxazone (CZ, Ibuprofen (IP–Methocarbamol (MC, Ketoprofen (KP–Chlorzoxazone (CZ and Diclofenac sodium (DS–Lidocaine hydrochloride (LC. The separation was run for all mixtures using borate buffer (20 mM, pH 9 containing 15% (v/v methanol and 100 mM sodium dodecyl sulphate (SDS at 15 kV and the components were detected at 214 nm. Different factors affecting the electrophoretic mobility of the seven investigated drugs were studied and optimized. The method was validated according to international conference of harmonization (ICH guidelines and United States pharmacopoeia (USP. The method was applied to the analysis of five pharmaceutical binary mixtures in their dosage forms. The results were compared with other reported high performance liquid chromatographic methods and no significant differences were observed. Keywords: Capillary electrophoresis, Micellar electrokinetic chromatographic method, Non-steroidal anti-inflammatory drugs, Pharmaceutical binary mixtures, Pharmaceutical analysis

Pixel-based CTE Correction of ACS/WFC: Modifications To The ACS Calibration Pipeline (CALACS)

Science.gov (United States)

Smith, Linda J.; Anderson, J.; Armstrong, A.; Avila, R.; Bedin, L.; Chiaberge, M.; Davis, M.; Ferguson, B.; Fruchter, A.; Golimowski, D.; Grogin, N.; Hack, W.; Lim, P. L.; Lucas, R.; Maybhate, A.; McMaster, M.; Ogaz, S.; Suchkov, A.; Ubeda, L.

2012-01-01

The Advanced Camera for Surveys (ACS) was installed on the Hubble Space Telescope (HST) nearly ten years ago. Over the last decade, continuous exposure to the harsh radiation environment has degraded the charge transfer efficiency (CTE) of the CCDs. The worsening CTE impacts the science that can be obtained by altering the photometric, astrometric and morphological characteristics of sources, particularly those farthest from the readout amplifiers. To ameliorate these effects, Anderson & Bedin (2010, PASP, 122, 1035) developed a pixel-based empirical approach to correcting ACS data by characterizing the CTE profiles of trails behind warm pixels in dark exposures. The success of this technique means that it is now possible to correct full-frame ACS/WFC images for CTE degradation in the standard data calibration and reduction pipeline CALACS. Over the past year, the ACS team at STScI has developed, refined and tested the new software. The details of this work are described in separate posters. The new code is more effective at low flux levels (repair ACS electronics) and pixel-based CTE correction. In addition to the standard cosmic ray corrected, flat-fielded and drizzled data products (crj, flt and drz files) there are three new equivalent files (crc, flc and drc) which contain the CTE-corrected data products. The user community will be able to choose whether to use the standard or CTE-corrected products.

Removal of heavy metals from sludge of Sanaru-Lake by electrokinetics

Energy Technology Data Exchange (ETDEWEB)

Seno, T.; Shiba, S.; Hirata, Y. [Dept. of Systems Engineering, Shizuoka Univ., Hamamatsu (Japan)

2001-07-01

Two kinds of experiments were carried out for the removal of heavy metals from soils by electrokinetic technique. One was the removal of lead from kaolinite by using a small-sized test cell. The effect of the kind of purging solutions (such as distilled water, tap water, acetic acid and nitric acid) on removal efficiency was examined. High removal efficiency was obtained for the acetic acid solution. It was found that the controlling pH of solution surrounding cathode had a significant influence on the removal efficiency. The other experiment was the removal of heavy metals from the bottom sludge of Sanaru Lake. Zinc, nickel and copper in the sludge were successfully removed, but lead and chromium were hardly able to remove from the sludge. The simplified one-dimensional mathematical model was proposed. The prediction by the model was qualitatively agreed with the experimental result. (orig.)

Microchannel electrokinetics of charged analytes in buffered solutions near floating electrodes

DEFF Research Database (Denmark)

Andersen, Mathias Bækbo; Wolfcale, Trevor; Gregersen, Misha Marie

to accurately predict such behavior in these flow regimes. Experimentally, using conventional fluorescence microscopy, we investigated the concentration gradient (as well as the associated electroosmosis, induced-charge electro-osmosis, and electrophoresis) of the charged analyte near the floating electrode......We present both experimental and numerical studies of nonlinear electrokinetic flow of buffered solutions seeded with dilute analytes in a straight microchannel (0.6 μm high, 250 μm wide, and 9000 μm long) with a 0.15 μm high 60 μm wide electrode situated at the bottom center of the channel...... as a function of analyte (1 to 10 μM fluorescein and bodipy) and buffer (1 to 10 mM borate and posphate) concentrations and an externally applied voltage drop (50 to 100 V) along the channel. We have implemented a nonlinear continuum kinetics model of the system involving the electric potential, the buffer flow...

Pump Application as Hydraulic Turbine – Pump as Turbine (PaT)

OpenAIRE

Rusovs, D

2009-01-01

The paper considers pump operation as hydraulic turbine with purpose to produce mechanical power from liquid flow. The Francis hydraulic turbine was selected for comparison with centrifugal pump in reverse operation. Turbine and centrifugal pump velocity triangles were considered with purpose to evaluate PaT efficiency. Shape of impeller blades for turbine and pumps was analysed. Specific speed calculation is carried out with purpose to obtain similarity in pump and turbine description. For ...

Final Report: Cooling Seasonal Energy and Peak Demand Impacts of Improved Duct Insulation on Fixed-Capacity (SEER 13) and Variable-Capacity (SEER 22) Heat Pumps

Energy Technology Data Exchange (ETDEWEB)

Withers, C. [Building America Partnership for Improved Residential Construction, Cocoa, FL (United States); Florida Solar Energy Center (FSEC), Cocoa, FL (United States); Cummings, J. [Building America Partnership for Improved Residential Construction, Cocoa, FL (United States); Florida Solar Energy Center (FSEC), Cocoa, FL (United States); Nigusse, B. [Building America Partnership for Improved Residential Construction, Cocoa, FL (United States); Florida Solar Energy Center (FSEC), Cocoa, FL (United States)

2016-09-01

A new generation of full variable-capacity, central, ducted air-conditioning (AC) and heat pump units has come on the market, and they promise to deliver increased cooling (and heating) efficiency. They are controlled differently than standard single-capacity (fixed-capacity) systems. Instead of cycling on at full capacity and then cycling off when the thermostat is satisfied, they can vary their capacity over a wide range (approximately 40% to 118% of nominal full capacity), thus staying “on” for up to twice as many hours per day compared to fixed-capacity systems of the same nominal capacity. The heating and cooling capacity is varied by adjusting the indoor fan air flow rate, compressor, and refrigerant flow rate as well as the outdoor unit fan air flow rate. Note that two-stage AC or heat pump systems were not evaluated in this research effort. The term dwell is used to refer to the amount of time distributed air spends inside ductwork during space-conditioning cycles. Longer run times mean greater dwell time and therefore greater exposure to conductive gains and losses.

Final Report: Cooling Seasonal Energy and Peak Demand Impacts of Improved Duct Insulation on Fixed-Capacity (SEER 13) and Variable-Capacity (SEER 22) Heat Pumps

Energy Technology Data Exchange (ETDEWEB)

Withers, C. [Building America Partnership for Improved Residential Construction, Cocoa, FL (United States); Florida Solar Energy Center, Cocoa, FL (United States); Cummings, J. [Building America Partnership for Improved Residential Construction, Cocoa, FL (United States); Florida Solar Energy Center, Cocoa, FL (United States); Nigusse, B. [Building America Partnership for Improved Residential Construction, Cocoa, FL (United States); Florida Solar Energy Center, Cocoa, FL (United States)

2016-09-08

A new generation of full variable-capacity, central, ducted air-conditioning (AC) and heat pump units has come on the market, and they promise to deliver increased cooling (and heating) efficiency. They are controlled differently than standard single-capacity (fixed-capacity) systems. Instead of cycling on at full capacity and then cycling off when the thermostat is satisfied, they can vary their capacity over a wide range (approximately 40% to 118% of nominal full capacity), thus staying “on” for up to twice as many hours per day compared to fixed-capacity systems of the same nominal capacity. The heating and cooling capacity is varied by adjusting the indoor fan air flow rate, compressor, and refrigerant flow rate as well as the outdoor unit fan air flow rate. Note that two-stage AC or heat pump systems were not evaluated in this research effort. The term dwell is used to refer to the amount of time distributed air spends inside ductwork during space-conditioning cycles. Longer run times mean greater dwell time and therefore greater exposure to conductive gains and losses.

Heat pumps

CERN Document Server

Macmichael, DBA

1988-01-01

A fully revised and extended account of the design, manufacture and use of heat pumps in both industrial and domestic applications. Topics covered include a detailed description of the various heat pump cycles, the components of a heat pump system - drive, compressor, heat exchangers etc., and the more practical considerations to be taken into account in their selection.

AcMNPV

African Journals Online (AJOL)

USER

2010-08-16

Aug 16, 2010 ... biosynthesis pathway and plays an important role in insect growth and .... Construction and propagation of recombined AcMNPV. The recombined ... infected by virus increased with incubation time (Figure. 3). The growth of ...

Modeling and reliability analysis of three phase z-source AC-AC converter

Directory of Open Access Journals (Sweden)

Prasad Hanuman

2017-12-01

Full Text Available This paper presents the small signal modeling using the state space averaging technique and reliability analysis of a three-phase z-source ac-ac converter. By controlling the shoot-through duty ratio, it can operate in buck-boost mode and maintain desired output voltage during voltage sag and surge condition. It has faster dynamic response and higher efficiency as compared to the traditional voltage regulator. Small signal analysis derives different control transfer functions and this leads to design a suitable controller for a closed loop system during supply voltage variation. The closed loop system of the converter with a PID controller eliminates the transients in output voltage and provides steady state regulated output. The proposed model designed in the RT-LAB and executed in a field programming gate array (FPGA-based real-time digital simulator at a fixedtime step of 10 μs and a constant switching frequency of 10 kHz. The simulator was developed using very high speed integrated circuit hardware description language (VHDL, making it versatile and moveable. Hardware-in-the-loop (HIL simulation results are presented to justify the MATLAB simulation results during supply voltage variation of the three phase z-source ac-ac converter. The reliability analysis has been applied to the converter to find out the failure rate of its different components.

Reactor coolant purification system circulation pumps (CUW pumps)

International Nuclear Information System (INIS)

Tsutsui, Toshiaki

1979-01-01

Coolant purification equipments for BWRs have been improved, and the high pressure purifying system has become the main type. The quantity of purifying treatment also changed to 2% of the flow rate of reactor feed water. As for the circulation pumps, canned motor pumps are adopted recently, and the improvements of reliability and safety are attempted. The impurities carried in by reactor feed water and the corrosion products generated in reactors and auxiliary equipments are activated by neutron irradiation or affect heat transfer adversely, adhering to fuel claddings are core structures. Therefore, a part of reactor coolant is led to the purification equipments, and returned to reactors after the impurities are eliminated perfectly. At the time of starting and stopping reactors, excess reactor water and the contaminated water from reactors are transferred to main condenser hot wells or waste treatment systems. Thus the prescribed water quality is maintained. The operational modes of and the requirements for the CUW pumps, the construction and the features of the canned motor type CUW pumps are explained. Recently, a pump operated for 11 months without any maintenance has been disassembled and inspected, but the wear of bearings has not been observed, and the high reliability of the pump has been proved. (Kako, I.)

Work plan, AP-102 mixer pump removal and pump replacement

International Nuclear Information System (INIS)

Jimenez, R.F.

1994-01-01

The objective of this work plan is to plan the steps and estimate the costs required to remove the failed AP-102 mixer pump, and to plan and estimate the cost of the necessary design and specification work required to order a new, but modified, mixer pump including the pump and pump pit energy absorbing design. The main hardware required for the removal of the mixer is as follows: a flexible receiver and blast shield; a metal container for the pulled mixer pump; and a trailer and strongback to haul and manipulate the container. Additionally: a gamma scanning device will be needed to detect the radioactivity emanating from the mixer as it is pulled from the tank; a water spray system will be required to remove tank waste from the surface of the mixer as it is pulled from the AP-102 tank; and a lifting yoke to lift the mixer from the pump pit (the SY-101 Mixer Lifting Yoke will be used). A ''green house'' will have to be erected over the AP-102 pump pit and an experienced Hoisting and Rigging crew must be assembled and trained in mixer pump removal methods before the actual removal is undertaken

Approaches to building single-stage AC/AC conversion switch-mode audio power amplifiers

Energy Technology Data Exchange (ETDEWEB)

Ljusev, P.; Andersen, Michael A.E.

2005-07-01

This paper discusses the possible topologies and promising approaches towards direct single-phase AC-AC conversion of the mains voltage for audio applications. When compared to standard Class-D switching audio power amplifiers with a separate power supply, it is expected that direct conversion will provide better efficiency and higher level of integration, leading to lower component count, volume and cost, but at the expense of a minor performance deterioration. (au)

Proportional-Integral-Resonant AC Current Controller

Directory of Open Access Journals (Sweden)

STOJIC, D.

2017-02-01

Full Text Available In this paper an improved stationary-frame AC current controller based on the proportional-integral-resonant control action (PIR is proposed. Namely, the novel two-parameter PIR controller is applied in the stationary-frame AC current control, accompanied by the corresponding parameter-tuning procedure. In this way, the proportional-resonant (PR controller, common in the stationary-frame AC current control, is extended by the integral (I action in order to enable the AC current DC component tracking, and, also, to enable the DC disturbance compensation, caused by the voltage source inverter (VSI nonidealities and by nonlinear loads. The proposed controller parameter-tuning procedure is based on the three-phase back-EMF-type load, which corresponds to a wide range of AC power converter applications, such as AC motor drives, uninterruptible power supplies, and active filters. While the PIR controllers commonly have three parameters, the novel controller has two. Also, the provided parameter-tuning procedure needs only one parameter to be tuned in relation to the load and power converter model parameters, since the second controller parameter is directly derived from the required controller bandwidth value. The dynamic performance of the proposed controller is verified by means of simulation and experimental runs.

Electrokinetically Enhanced Delivery for ERD Remediation of Chlorinated Ethenes in a Fractured Limestone Aquifer

DEFF Research Database (Denmark)

Broholm, Mette Martina; Hyldegaard, Bente Højlund; With Nedergaard, Lærke

causing very long remediation timeframes. Electrokinetics (EK) offers some unique transport processes, which can potentially overcome the diffusion limitations in the matrix. A novel technology combines ERD and EK for enhanced delivery. The combined technology (EK-BIO) has shown promising results in clay....... Experimental work on EK-BIO in limestone was conducted in a laboratory setup with limestone cores. EK was demonstrated to be promising in establishing enhanced contact between the donor lactate, bacteria, and cis-DCE within the limestone matrix. Complete dechlorination is expected to take place in the matrix......, since back diffusion limitations in the limestone matrix are overcome. This is essential for the overall time perspective of a remediation in limestone aquifers....

Enantioseparation of palonosetron hydrochloride by micellar electrokinetic chromatography with sodium cholate as chiral selector.

Science.gov (United States)

Tian, Kan; Chen, Hongli; Tang, Jianghong; Chen, Xingguo; Hu, Zhide

2006-11-03

The enantioseparation of four stereoisomers of palonosetron hydrochloride by micellar electrokinetic chromatography using sodium cholate as chiral surfactant was described. Sodium cholate was shown to be effective in separating palonosetron hydrochloride stereoisomers. For method optimization, several parameters such as sodium cholate concentration, buffer pH and concentration, the types and concentration of organic modifiers and applied voltage, on the enantioseparation were evaluated and the optimum conditions were obtained as follows: 30 mM borate buffer (pH 9.40) containing 70 mM sodium cholate and 20% (v/v) methanol with an applied voltage of 20 kV. Under these conditions, baseline separation of palonosetron hydrochloride stereoisomers was achieved within 18 min.

An analytical method for defining the pump`s power optimum of a water-to-water heat pump heating system using COP

Directory of Open Access Journals (Sweden)

Nyers Jozsef

2017-01-01

Full Text Available This paper analyzes the energy efficiency of the heat pump and the complete heat pump heating system. Essentially, the maximum of the coefficient of performance of the heat pump and the heat pump heating system are investigated and determined by applying a new analytical optimization procedure. The analyzed physical system consists of the water-to-water heat pump, circulation and well pump. In the analytical optimization procedure the "first derivative equal to zero" mathematical method is applied. The objective function is the coefficient of performance of the heat pump, and the heat pump heating system. By using the analytical optimization procedure and the objective function, as the result, the local and the total energy optimum conditions with respect to the mass flow rate of hot and cold water i. e. the power of circulation or well pump are defined.

Spatial distribution of mechanical forces and ionic flux in electro-kinetic instability near a permselective membrane

Science.gov (United States)

Magnico, Pierre

2018-01-01

This paper is devoted to the numerical investigation of electro-kinetic instability in a polarization layer next to a cation-exchange membrane. An analysis of some properties of the electro-kinetic instability is followed by a detailed description of the fluid flow structure and of the spatial distribution of the ionic flux. In this aim, the Stokes-Poisson-Nernst-Planck equation set is solved until the Debye length scale. The results show that the potential threshold of the marginal instability and the current density depend on the logarithm of the concentration at the membrane surface. The size of the stable vortices seems to be an increasing function of the potential drop. The fluid motion is induced by the electric force along the maximum concentration in the extended space charge (ESC) region and by the pressure force in the region around the inner edge of the ESC layer. Two spots of kinetic energy are located in the ESC region and between the vortices. The cationic motion, controlled by the electric field and the convection, presents counter-rotating vortices in the stagnation zone located in the fluid ejection region. The anion transport is also characterized by two independent layers which contain counter-rotating vortices. The first one is in contact with the stationary reservoir. In the second layer against the membrane, the convection, and the electric field control, the transversal motion, the Fickian diffusion, and the convection are dominant in the longitudinal direction. Finally, the longitudinal disequilibrium of potential and pressure along the membrane is analyzed.

Electromagnetic pump technology

International Nuclear Information System (INIS)

Prabhakar, R.

1994-01-01

Fast Breeder Reactors have an important role to play in our nuclear power programme. Liquid metal sodium is used as the coolant for removing fission heat generated in fast reactors and a distinctive physical property of sodium is its high electrical conductivity. This enables application of electromagnetic (EM) pumps, working on same principle as electric motors, for pumping liquid sodium. Due to its lower efficiency as compared to centrifugal pumps, use of EM pumps has been restricted to reactor auxiliary circuits and experimental facilities. As part of our efforts to manufacture fast reactor components indigenously, work on the development of two types of EM pumps namely flat linear induction pump (FLIP) and annular linear induction pump (ALIP) has been undertaken. Design procedures based on an equivalent circuit approach have been established and results from testing a 5.6 x 10E-3 Cum/s (20 Cum/h) FLIP in a sodium loop were used to validate the procedure. (author). 7 refs., 6 figs

Pumping life

DEFF Research Database (Denmark)

Sitsel, Oleg; Dach, Ingrid; Hoffmann, Robert Daniel

2012-01-01

The name PUMPKIN may suggest a research centre focused on American Halloween traditions or the investigation of the growth of vegetables – however this would be misleading. Researchers at PUMPKIN, short for Centre for Membrane Pumps in Cells and Disease, are in fact interested in a large family o......’. Here we illustrate that the pumping of ions means nothing less than the pumping of life....

Nanopore density effect of polyacrylamide gel plug on electrokinetic ion enrichment in a micro-nanofluidic chip

Science.gov (United States)

Wang, Jun-yao; Xu, Zheng; Li, Yong-kui; Liu, Chong; Liu, Jun-shan; Chen, Li; Du, Li-qun; Wang, Li-ding

2013-07-01

In this paper, the nanopore density effect on ion enrichment is quantitatively described with the ratio between electrophoresis flux and electroosmotic flow flux based on the Poisson-Nernst-Planck equations. A polyacrylamide gel plug is integrated into a microchannel to form a micro-nanofluidic chip. With the chip, electrokinetic ion enrichment is relatively stable and enrichment ratio of fluorescein isothiocyanate can increase to 600-fold within 120 s at the electric voltage of 300 V. Both theoretical research and experiments show that enrichment ratio can be improved through increasing nanopore density. The result will be beneficial to the design of micro-nanofluidic chips.

Electroosmosis modulated biomechanical transport through asymmetric microfluidics channel

Science.gov (United States)

Jhorar, R.; Tripathi, D.; Bhatti, M. M.; Ellahi, R.

2018-05-01

This article addresses the electrokinetically modulated biomechanical transport through a two-dimensional asymmetric microchannel induced by peristaltic waves. Electrokinetic transport with peristaltic phenomena grabbed a significant attention due to its novel applications in engineering. Electrical fields also provide an excellent mode for regulating flows. The electrohydrodynamics problem is modified by means of Debye-Hückel linearization. Firstly, the governing flow problem is described by continuity and momentum equations in the presence of electrokinetic forces in Cartesian coordinates, then long wavelength and low/zero Reynolds ("neglecting the inertial forces") approximations are applied to modify the governing flow problem. The resulting differential equations are solved analytically in order to obtain exact solutions for velocity profile whereas the numerical integration is carried out to analyze the pumping characteristics. The physical behaviour of sundry parameters is discussed for velocity profile, pressure rise and volume flow rate. In particular, the behaviour of electro-osmotic parameter, phase difference, and Helmholtz-Smoluchowski velocity is examined and discussed. The trapping mechanism is also visualized by drawing streamlines against the governing parameters. The present study offers various interesting results that warrant further study on electrokinetic transport with peristalsis.

Electroremediation of lead and vanadium of industrial residues; Remediacao eletrocinetica de chumbo e vanadio em residuos industriais

Energy Technology Data Exchange (ETDEWEB)

Abramchuk, Danusa; Iryoda, Kathia Izumi; Pedrazzoli, Carina [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Dept. de Engenharia Quimica; Ponte, Haroldo de Araujo; Ponte, Maria Jose de Jeronimo [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil)

2004-07-01

Every year many areas were polluted with heavy metals and other dangerous materials, causing enormous impacts in the quality of rivers and soils. The soil remediation techniques 'in situ' were efficient for the removal of heavy metals, as the electrokinetic recovery: an up-to-date technology that has attracting the interest of many researchers and government since the decade of 90. The electrokinetic remediation technique is based on application of a low intensity continuous current through the soil among two or more electrodes. The current mobilizes electric charged species, particles and ions in the soil by the following processes: electromigration, electro osmotic and electrolysis. The purpose is the evaluation of the electrokinetic technique application for the lead and vanadium remediation from solid wastes. Profiles of pH and concentration and their variation in time throughout an electrokinetical reactor were investigated in a system submitted to a constant electric field. The profiles of pH indicated great alkalinization in the cathodic region and acidification in the anodic one. As a consequence, there was a precipitation process of the metallic ions that have migrated to this region. This process favors the removal of metallic ions by pumping. (author)

Champagne Heat Pump

Science.gov (United States)

Jones, Jack A.

2004-01-01

The term champagne heat pump denotes a developmental heat pump that exploits a cycle of absorption and desorption of carbon dioxide in an alcohol or other organic liquid. Whereas most heat pumps in common use in the United States are energized by mechanical compression, the champagne heat pump is energized by heating. The concept of heat pumps based on other absorption cycles energized by heat has been understood for years, but some of these heat pumps are outlawed in many areas because of the potential hazards posed by leakage of working fluids. For example, in the case of the water/ammonia cycle, there are potential hazards of toxicity and flammability. The organic-liquid/carbon dioxide absorption/desorption cycle of the champagne heat pump is similar to the water/ammonia cycle, but carbon dioxide is nontoxic and environmentally benign, and one can choose an alcohol or other organic liquid that is also relatively nontoxic and environmentally benign. Two candidate nonalcohol organic liquids are isobutyl acetate and amyl acetate. Although alcohols and many other organic liquids are flammable, they present little or no flammability hazard in the champagne heat pump because only the nonflammable carbon dioxide component of the refrigerant mixture is circulated to the evaporator and condenser heat exchangers, which are the only components of the heat pump in direct contact with air in habitable spaces.

Pumping of methane by an ionization assisted Zr/Al getter pump

International Nuclear Information System (INIS)

Shen, G.L.

1987-01-01

The pumping of methane by an ionization assisted Zr/Al getter pump has been investigated. This pump consists of 12 pieces of ring getters. A spiral shape W filament is located within the ring getters. A bias voltage is applied across the filament and the getter itself. The experiments have shown that (1) when the bias voltage is turned off, the pumping speed of the getter pump for methane increases exponentially with the filament temperature; (2) when the filament temperature is held constant, its pumping speed varies directly with the ionization electron current; (3) when the filament temperature is 2063 0 C and the electron current is 57 mA, the pumping speed of the Zr/Al getter pump is 475 ml/s, and the specific speed is 16.8 ml/s cm 2 ; and (4) an activation energy and critical temperature measured for methane molecules decomposition are, respectively, 47.4 kcal/mol and about 1700 0 C. Analysis of the results indicates that methane is pumped by an ionization assisted Zr/Al getter pump not because of the adsorption and the diffusion of methane molecules directly, but because methane molecules are decomposed as C and H 2 through a catalysis of the hot W filament, carbon is adsorbed on the surface of the W filament, and is diffused into the interior of the W lattice. H 2 is immediately absorbed by the Zr/Al getters. Besides, electron impact with CH 4 would result in the additional decomposition and ionization, then the effect of electron bombardment enhances methane pumping by the Zr/Al getters

Low ac loss geometries in YBCO coated conductors

International Nuclear Information System (INIS)

Duckworth, R.C.; List, F.A.; Paranthaman, M.P.; Rupich, M.W.; Zhang, W.; Xie, Y.Y.; Selvamanickam, V.

2007-01-01

Reduction of ac losses in applied ac fields can be accomplished through either the creation of filaments and bridging in YBCO coated conductors or by an assembly of narrow width YBCO tapes. The ac losses for each of these geometries were measured at 77 K in perpendicular ac fields up to 100 mT. Despite physical isolation of the filaments, coupling losses were still present in the samples when compared to the expected hysteretic loss. In addition to filamentary conductors the assembly of stacked YBCO conductor provides an alternative method of ac loss reduction. When compared to a 4-mm wide YBCO coated conductor with a critical current of 60 A, the ac loss in a stack of 2-mm wide YBCO coated conductors with a similar total critical current was reduced. While the reduction in ac loss in a 2-mm wide stack coincided with the reduction in the engineering current density of the conductor, further reduction of ac loss was obtained through the splicing of the 2-mm wide tapes with low resistance solders

Low ac loss geometries in YBCO coated conductors

Energy Technology Data Exchange (ETDEWEB)

Duckworth, R.C. [Oak Ridge National Laboratory, One Bethel Valley Road, P.O. Box 2008, MS-6305, Oak Ridge, TN 37831-6305 (United States)], E-mail: duckworthrc@ornl.gov; List, F.A.; Paranthaman, M.P. [Oak Ridge National Laboratory, One Bethel Valley Road, P.O. Box 2008, MS-6305, Oak Ridge, TN 37831-6305 (United States); Rupich, M.W.; Zhang, W. [American Superconductor, Two Technology Drive, Westborough, MA 01581 (United States); Xie, Y.Y.; Selvamanickam, V. [SuperPower, 450 Duane Ave, Schenectady, NY 12304 (United States)

2007-10-01

Reduction of ac losses in applied ac fields can be accomplished through either the creation of filaments and bridging in YBCO coated conductors or by an assembly of narrow width YBCO tapes. The ac losses for each of these geometries were measured at 77 K in perpendicular ac fields up to 100 mT. Despite physical isolation of the filaments, coupling losses were still present in the samples when compared to the expected hysteretic loss. In addition to filamentary conductors the assembly of stacked YBCO conductor provides an alternative method of ac loss reduction. When compared to a 4-mm wide YBCO coated conductor with a critical current of 60 A, the ac loss in a stack of 2-mm wide YBCO coated conductors with a similar total critical current was reduced. While the reduction in ac loss in a 2-mm wide stack coincided with the reduction in the engineering current density of the conductor, further reduction of ac loss was obtained through the splicing of the 2-mm wide tapes with low resistance solders.

Breastfeeding FAQs: Pumping

Science.gov (United States)

... of pump is best? You can buy or rent a breast pump from lactation consultants, hospitals, retail ... place to do it. Many companies offer their employees pumping and nursing areas. If yours doesn't, ...

Development and evaluation of cryosorption pump and cryotrapping pump for CTR applications

International Nuclear Information System (INIS)

Kuribayashi, S.; Ota, H.; Sato, H.

1986-01-01

In order to obtain the engineering data to design compound cryopump for CTR, the authors tested the cryosorption pump and cryotrapping pump. The cryosorption panel was consisted of coconut charcoal metallically bonded to 4.2K cryopanel by brazing. The initial pumping speed of helium of cryosorption pump was found to be ≅2.2 iota/scm/sup 2/. The speed dropped off with loading (about 8 Torr iota/cm/sup 2/) to 1.5 iota/scm/sup 2/. The initial helium pumping speed of the 4.2K cryotrapping pump by argon spray was found to be ≅6 iota/scm/sup 2/. The speed, however, dropped off with loading (≅0.3 Torr iota/cm/sup 2/) to less than 5%. These results indicate that the cryosorption pump by coconut charcoal is superior to the cryotrapping pump, because the capacity of the former is larger than the latter

Efficiency and threshold pump intensity of CW solar-pumped solid-state lasers

Science.gov (United States)

Hwang, In H.; Lee, Ja H.

1991-01-01

The authors consider the relation between the threshold pumping intensity, the material properties, the resonator parameters, and the ultimate slope efficiencies of various solid-state laser materials for solar pumping. They clarify the relation between the threshold pump intensity and the material parameters and the relation between the ultimate slope efficiency and the laser resonator parameters such that a design criterion for the solar-pumped solid-state laser can be established. Among the laser materials evaluated, alexandrite has the highest slope efficiency of about 12.6 percent; however, it does not seem to be practical for a solar-pumped laser application because of its high threshold pump intensity. Cr:Nd:GSGG is the most promising for solar-pumped lasing. Its threshold pump intensity is about 100 air-mass-zero (AM0) solar constants and its slope efficiency is about 12 percent when thermal deformation is completely prevented.

Pumping station design for a pumped-storage wind-hydro power plant

International Nuclear Information System (INIS)

Anagnostopoulos, John S.; Papantonis, Dimitris E.

2007-01-01

This work presents a numerical study of the optimum sizing and design of a pumping station unit in a hybrid wind-hydro plant. The standard design that consists of a number of identical pumps operating in parallel is examined in comparison with two other configurations, using one variable-speed pump or an additional set of smaller jockey pumps. The aim is to reduce the amount of the wind generated energy that cannot be transformed to hydraulic energy due to power operation limits of the pumps and the resulting step-wise operation of the pumping station. The plant operation for a period of one year is simulated by a comprehensive evaluation algorithm, which also performs a detailed economic analysis of the plant using dynamic evaluation methods. A preliminary study of the entire plant sizing is carried out at first using an optimization tool based on evolutionary algorithms. The performance of the three examined pumping station units is then computed and analyzed in a comparative study. The results reveal that the use of a variable-speed pump constitutes the most effective and profitable solution, and its superiority is more pronounced for less dispersed wind power potential

Electrokinetic extraction of surfactants and heavy metals from sewage sludge

International Nuclear Information System (INIS)

Ferri, Violetta; Ferro, Sergio; Martinez-Huitle, Carlos A.; De Battisti, Achille

2009-01-01

Waste management represents a quite serious problem involving aspects of remediation technologies and potential re-utilization in different fields of human activities. Of course, wastes generated in industrial activities deserve more attention because of the nature and amount of xenobiotic components, often difficult to be eliminated. However, also ordinary wastes of urban origin are drawing more and more attention, depending on the concentration of noxious substances like surfactants and some heavy metal, which may eventually require expensive disposal. In the present paper, a research has been carried out on the application of electrokinetic treatments for the abatement of the above xenobiotic components from sewage sludge generated in urban wastewater treatment plants. Experiments were carried out on a laboratory scale, in a 250 mm x 50 mm x 100 mm cell, using 250-300 g of sludge for each test and current densities between 2.4 and 5.7 mA cm -2 . As a general result, quite significant abatements of heavy-metal ions and surfactants were achieved, with relatively low energy consumption

A study of the ac Stark effect in doped photonic crystals

Energy Technology Data Exchange (ETDEWEB)

Haque, I; Singh, Mahi R [Department of Physics and Astronomy, University of Western Ontario, London, ON, N6A 3K7 (Canada)

2007-04-16

In this paper we present calculations of level populations and susceptibility for an ensemble of five-level atoms doped in a photonic crystal, using the master equation method. The atoms in the ensemble interact with the crystal which acts as a reservoir and are coupled with two strong pump fields and a weak probe field. It is found that, by manipulating the resonance energy associated with one of the decay channels of the atom, the system can be switched between an inverted and a non-inverted state. We have also observed the ac Stark effect in these atoms and have shown that due to the role played by the band structure of the photonic crystal, it is possible to switch between an absorption state and a non-absorption state of the atomic system. This is a very important finding as techniques of rendering material systems transparent to resonant laser radiation are very desirable in the fabrication of novel optical and photonic devices.

Low-frequency, self-sustained oscillations in inductively coupled plasmas used for optical pumping

Energy Technology Data Exchange (ETDEWEB)

Coffer, J.; Encalada, N.; Huang, M.; Camparo, J. [Physical Sciences Laboratories, The Aerospace Corporation 2310, E. El Segundo Blvd., El Segundo, California 90245 (United States)

2014-10-28

We have investigated very low frequency, on the order of one hertz, self-pulsing in alkali-metal inductively-coupled plasmas (i.e., rf-discharge lamps). This self-pulsing has the potential to significantly vary signal-to-noise ratios and (via the ac-Stark shift) resonant frequencies in optically pumped atomic clocks and magnetometers (e.g., the atomic clocks now flying on GPS and Galileo global navigation system satellites). The phenomenon arises from a nonlinear interaction between the atomic physics of radiation trapping and the plasma's electrical nature. To explain the effect, we have developed an evaporation/condensation theory (EC theory) of the self-pulsing phenomenon.

AC conductivity and dielectric behavior of bulk Furfurylidenemalononitrile

Science.gov (United States)

El-Nahass, M. M.; Ali, H. A. M.

2012-06-01

AC conductivity and dielectric behavior for bulk Furfurylidenemalononitrile have been studied over a temperature range (293-333 K) and frequency range (50-5×106 Hz). The frequency dependence of ac conductivity, σac, has been investigated by the universal power law, σac(ω)=Aωs. The variation of the frequency exponent (s) with temperature was analyzed in terms of different conduction mechanisms, and it was found that the correlated barrier hopping (CBH) model is the predominant conduction mechanism. The temperature dependence of σac(ω) showed a linear increase with the increase in temperature at different frequencies. The ac activation energy was determined at different frequencies. Dielectric data were analyzed using complex permittivity and complex electric modulus for bulk Furfurylidenemalononitrile at various temperatures.

BWR series pump recirculation system

International Nuclear Information System (INIS)

Dillmann, C.W.

1992-01-01

This patent describes a recirculation system for driving reactor coolant water contained in an annular downcomer defined between a boiling water reactor vessel and a reactor core spaced radially inwardly therefrom. It comprises a plurality of circumferentially spaced second pumps disposed in the downcomer, each including an inlet for receiving from the downcomer a portion of the coolant water as pump inlet flow, and an outlet for discharging the pump inlet flow pressurized in the second pump as pump outlet flow; and means for increasing pressure of the pump inlet flow at the pump inlet including a first pump disposed in series flow with the second pump for first receiving the pump inlet flow from the downcomer and discharging to the second pump inlet flow pressurized in the first pump

Early outcome of off-pump versus on-pump coronary revascularization

African Journals Online (AJOL)

Introduction: The use of coronary artery bypass surgery (CABG) with cardiopulmonary bypass (CPB) or without CPB technique (off-pump) can be associated with different mortality and morbidity and their outcomes remain uncertain. The goal of this study was to evaluate the early outcome of on-pump versus off-pump CABG.

Assay Methods for ACS Activity and ACS Phosphorylation by MAP Kinases In Vitro and In Vivo.

Science.gov (United States)

Han, Xiaomin; Li, Guojing; Zhang, Shuqun

2017-01-01

Ethylene, a gaseous phytohormone, has profound effects on plant growth, development, and adaptation to the environment. Ethylene-regulated processes begin with the induction of ethylene biosynthesis. There are two key steps in ethylene biosynthesis. The first is the biosynthesis of 1-aminocyclopropane-1-carboxylic acid (ACC) from S-Adenosyl-Methionine (SAM), a common precursor in many metabolic pathways, which is catalyzed by ACC synthase (ACS). The second is the oxidative cleavage of ACC to form ethylene under the action of ACC oxidase (ACO). ACC biosynthesis is the committing and generally the rate-limiting step in ethylene biosynthesis. As a result, characterizing the cellular ACS activity and understanding its regulation are important. In this chapter, we detail the methods used to measure, (1) the enzymatic activity of both recombinant and native ACS proteins, and (2) the phosphorylation of ACS protein by mitogen-activated protein kinases (MAPKs) in vivo and in vitro.

Pumps in wearable ultrafiltration devices: pumps in wuf devices.

Science.gov (United States)

Armignacco, Paolo; Garzotto, Francesco; Bellini, Corrado; Neri, Mauro; Lorenzin, Anna; Sartori, Marco; Ronco, Claudio

2015-01-01

The wearable artificial kidney (WAK) is a device that is supposed to operate like a real kidney, which permits prolonged, frequent, and continuous dialysis treatments for patients with end-stage renal disease (ESRD). Its functioning is mainly related to its pumping system, as well as to its dialysate-generating and alarm/shutoff ones. A pump is defined as a device that moves fluids by mechanical action. In such a context, blood pumps pull blood from the access side of the dialysis catheter and return the blood at the same rate of flow. The main aim of this paper is to review the current literature on blood pumps, describing the way they have been functioning thus far and how they are being engineered, giving details about the most important parameters that define their quality, thus allowing the production of a radar comparative graph, and listing ideal pumps' features. © 2015 S. Karger AG, Basel.

TFTR ultrahigh-vacuum pumping system incorporating mercury diffusion pumps

International Nuclear Information System (INIS)

Sink, D.A.; Sniderman, M.

1976-06-01

The TFTR vacuum vessel will have a system of four 61 cm diameter mercury diffusion pumps to provide a base pressure in the 10 -8 to 10 -9 Torr range as well as a low impurity level within the vessel. The system, called the Torus Vacuum Pumping System (TVPS), will be employed with the aid of an occasional 250 0 C bakeout in situ as well as periodic applications of aggressive discharge cleaning. The TVPS is an ultrahigh-vacuum (UHV) system using no elastomers as well as being a closed system with respect to tritium or any tritiated gases. The backing system employing approximately 75 all-metal isolation valves is designed with the features of redundancy and flexibility employed in a variety of ways to meet the fundamental requirements and functions enumerated for the TVPS. Since the design, is one which is a modification of the conceptual design of the TVPS, those features which have changed are discussed. Calculations are presented for the major performance parameters anticipated for the TVPS and include conductances, effective pumping speeds, base pressures, operating parameters, getter pump parameters, and calculations of time constants associated with leak checking. Modifications in the vacuum pumping system for the guard regions on the twelve bellows sections are presented so that it is compatible with the main TVPS. The bellows pumping system consists of a mechanical pump unit, a zirconium aluminum getter pump unit and a residual gas analyzer. The control and management of the TVPS is described with particular attention given to providing both manual and automatic control at a local station and at the TFTR Central Control. Such operations as testing, maintenance, leak checking, startup, bakeout, and various other operations are considered in some detail. Various aspects related to normal pulsing, discharge cleaning, non-tritium operations and tritium operations are also taken into consideration. A cost estimate is presented

Photovoltaic pump systems

Science.gov (United States)

Klockgether, J.; Kiessling, K. P.

1983-09-01

Solar pump systems for the irrigation of fields and for water supply in regions with much sunshine are discussed. For surface water and sources with a hoisting depth of 12 m, a system with immersion pumps is used. For deep sources with larger hoisting depths, an underwater motor pump was developed. Both types of pump system meet the requirements of simple installation and manipulation, safe operation, maintenance free, and high efficiency reducing the number of solar cells needed.

Damages on pumps and systems the handbook for the operation of centrifugal pumps

CERN Document Server

Merkle, Thomas

2014-01-01

Damage on Pumps and Systems. The Handbook for the Operation of Centrifugal Pumps offers a combination of the theoretical basics and practical experience for the operation of circulation pumps in the engineering industry. Centrifugal pumps and systems are extremely vulnerable to damage from a variety of causes, but the resulting breakdown can be prevented by ensuring that these pumps and systems are operated properly. This book provides a total overview of operating centrifugal pumps, including condition monitoring, preventive maintenance, life cycle costs, energy savings and economic aspects. Extra emphasis is given to the potential damage to these pumps and systems, and what can be done to prevent breakdown. Addresses specific issues about pumping of metal chips, sand, abrasive dust and other solids in fluidsEmphasis on economic and efficiency aspects of predictive maintenance and condition monitoring Uses life cycle costs (LCC) to evaluate and calculate the costs of pumping systems

Pumping behavior of ion pump elements at high and misaligned magnetic fields

Energy Technology Data Exchange (ETDEWEB)

Hseuh, H. C.; Jiang, W. S.; Mapes, M.

1994-11-01

The pumping speeds of several diode type ion pump elements with cell radii of 5 mm, 5.5 mm, 6 mm, 9 mm and 12 mm were measured while being subjected to a magnetic field B, ranging from 500 Gauss up to 15 KG, and misalignment angles (angles between the direction of B and the anode axis) from 0 to 13 degrees. The pumping speeds of elements with the 9 mm and 12 mm cells peaked around 1--2 KG, then dropped off rapidly with an increasing magnetic field. The pumping speeds of the smaller cell elements remained constant with an increasing magnetic field. The pumping speeds of all the elements decreased with increasing misalignment. The measured pumping speeds from this study are 3--4 times lower than the calculated pumping, speeds using previously reported empirical formulae.

Pumping behavior of ion pump elements at high and misaligned magnetic fields

International Nuclear Information System (INIS)

Hseuh, H.C.; Jiang, W.S.; Mapes, M.

1994-01-01

The pumping speeds of several diode type ion pump elements with cell radii of 5 mm, 5.5 mm, 6 mm, 9 mm and 12 mm were measured while being subjected to a magnetic field B, ranging from 500 Gauss up to 15 KG, and misalignment angles (angles between the direction of B and the anode axis) from 0 to 13 degrees. The pumping speeds of elements with the 9 mm and 12 mm cells peaked around 1--2 KG, then dropped off rapidly with an increasing magnetic field. The pumping speeds of the smaller cell elements remained constant with an increasing magnetic field. The pumping speeds of all the elements decreased with increasing misalignment. The measured pumping speeds from this study are 3--4 times lower than the calculated pumping, speeds using previously reported empirical formulae

Liquid metal pump

International Nuclear Information System (INIS)

Pennell, W.E.

1981-01-01

A liquid metal pump comprising a shaft support structure which is isolated from the pump housing for better preservation of alignment of shaft bearings. The shaft carries an impeller and the support structure carries an impeller cage which is slidably disposed in a diffuser so as to allow complete removal of pump internals for inspection and repair. The diffuser is concentrically supported in the pump housing which also takes up all reaction forces generated by the discharge of the liquid metal from the diffuser, with floating seals arranged between impeller cage and the diffuser. The space between the diffuser and the pump housing permits the incoming liquid to essentially surround the diffuser. (author)

Rotary piston blood pumps: past developments and future potential of a unique pump type.

Science.gov (United States)

Wappenschmidt, Johannes; Autschbach, Rüdiger; Steinseifer, Ulrich; Schmitz-Rode, Thomas; Margreiter, Raimund; Klima, Günter; Goetzenich, Andreas

2016-08-01

The design of implantable blood pumps is either based on displacement pumps with membranes or rotary pumps. Both pump types have limitations to meet the clinical requirements. Rotary piston blood pumps have the potential to overcome these limitations and to merge the benefits. Compared to membrane pumps, they are smaller and with no need for wear-affected membranes and valves. Compared to rotary pumps, the blood flow is pulsatile instead of a non-physiological continuous flow. Furthermore, the risk of flow-induced blood damage and platelet activation may be reduced due to low shear stress to the blood. The past developments of rotary piston blood pumps are summarized and the main problem for long-term application is identified: insufficient seals. A new approach with seal-less drives is proposed and current research on a simplified rotary piston design is presented. Expert commentary: The development of blood pumps focuses mainly on the improvement of rotary pumps. However, medical complications indicate that inherent limitations of this pump type remain and restrict the next substantial step forward in the therapy of heart failure patients. Thus, research on different pump types is reasonable. If the development of reliable drives and bearings succeeds, rotary piston blood pumps become a promising alternative.

RNA interference suppression of mucin 5AC (MUC5AC reduces the adhesive and invasive capacity of human pancreatic cancer cells

Directory of Open Access Journals (Sweden)

Yamada Nobuya

2010-05-01

Full Text Available Abstract Background MUC5AC is a secretory mucin normally expressed in the surface muconous cells of stomach and bronchial tract. It has been known that MUC5AC de novo expression occurred in the invasive ductal carcinoma and pancreatic intraepithelial neoplasm with no detectable expression in normal pancreas, however, its function remains uncertain. Here, we report the impact of MUC5AC on the adhesive and invasive ability of pancreatic cancer cells. Methods We used two MUC5AC expressing cell lines derived from human pancreatic cancer, SW1990 and BxPC3. Small-interfering (si RNA directed against MUC5AC were used to assess the effects of MUC5AC on invasion and adhesion of pancreas cancer cells in vitro and in vivo. We compared parental cells (SW1990 and BxPC3 with MUC5AC suppressed cells by si RNA (si-SW1990 and si-BxPC3. Results MUC5AC was found to express in more than 80% of pancreatic ductal carcinoma specimens. Next we observed that both of si-SW1990 and si-BxPC3 showed significantly lower adhesion and invasion to extracellular matrix components compared with parental cell lines. Expression of genes associated with adhesion and invasion including several integerins, matrix metalloproteinase (MMP -3 and vascular endothelial growth factor (VEGF were down-regulated in both MUC5AC suppressed cells. Furthermore, production of VEGF and phosphorylation of VEGFR-1 were significantly reduced by MUC5AC down regulation. Both of si-SW1990 and si-BxPC3 attenuated activation of Erk1/2. In vivo, si-SW1990 did not establish subcutaneous tumor in nude mice. Conclusions Knockdown of MUC5AC reduced the ability of pancreatic cancer cells to adhesion and invasion, suggesting that MUC5AC might contribute to the invasive motility of pancreatic cancer cells by enhancing the expression of integrins, MMP-3, VEGF and activating Erk pathway.

Investigation of electrokinetic and electrorheological properties of polyindole prepared in the presence of a surfactant

Energy Technology Data Exchange (ETDEWEB)

Unal, H. Ibrahim, E-mail: hiunal@gazi.edu.tr [Gazi University, Chemistry Department, Smart Materials Research Lab., Ankara (Turkey); Sahan, Bekir; Erol, Ozlem [Gazi University, Chemistry Department, Smart Materials Research Lab., Ankara (Turkey)

2012-05-15

Highlights: Black-Right-Pointing-Pointer Aggregated morphology was determined for PIN, spherical and porous hollows and everniae form morphologies were recorded for SPIN. Black-Right-Pointing-Pointer The PIN/SO and SPIN/SO systems showed almost similar electrokinetic attitudes and a typical shear thinning non-Newtonian viscoelastic behavior, vibration damping capability at elevated frequencies, and enhanced storage moduli with increasing temperature. Black-Right-Pointing-Pointer Non-linear recoverable viscoelastic manner was revealed from the creep-recovery experiments under external electric field. - Abstract: In this study, synthesis of polyindole (PIN) was carried out without and with the presence of a sodium dodecyl sulfate (SDS) surfactant (SPIN), using FeCl{sub 3} as an oxidizing agent. The synthesized materials were subjected to various characterizations techniques namely: particle size, magnetic susceptibility, elemental analysis, density, conductivity, dielectric constant, FTIR, {sup 1}H NMR, TGA, XRD, and SEM. Characterization results revealed the successful preparation of the homopolymers of PIN and SPIN. Zeta ({zeta})-potentials of the samples were measured in aqueous and non-aqueous (silicone oil, SO) media. Electrokinetic properties of PIN and SPIN in aqueous media were determined by {zeta}-potential measurements in the presence of various electrolytes (NaCl, BaCl{sub 2}, AlCl{sub 3}, Na{sub 2}SO{sub 4}) and surfactants (cetyltrimethyl ammonium bromide, SDS, and Triton X-100). Besides, the effect of pH onto {zeta}-potentials of the materials was also examined. The suspensions prepared in SO were subjected to external electric field strength and their electrorheological (ER) properties were investigated. Then the effects of shear rate, frequency, and temperature onto ER activities of the suspensions were examined. Further, creep and creep-recovery tests were applied to the PIN/SO and SPIN/SO suspension systems and reversible non-linear viscoelastic

High-vacuum plasma pump

International Nuclear Information System (INIS)

Dorodnov, A.M.; Minajchev, V.E.; Miroshkin, S.I.

1980-01-01

The action of an electric-arc high-vacuum pump intended for evacuating the volumes in which the operation processes are followed by a high gas evolution is considered. The operation of the pump is based on the principle of controlling the getter feed according to the gas load and effect of plasma sorbtion pumping. The pump performances are given. The starting pressure is about 5 Pa, the limiting residual pressure is about 5x10 -6 Pa, the pumping out rate of nitrogen in the pressure range 5x10 -5 -5x10 -3 Pa accounts for about 4000 l/s, the power consumption comes to 6 kW. Analyzing the results of the test operation of the pump, it has been concluded that its principal advantages are the high starting pressure, controlled getter feed rate and possibility of pumping out the gases which are usually pumped out with difficulty. The operation reliability of the pump is defined mainly by reliable operation of the ignition system of the vacuum arc [ru

Gamma-irradiation produces active chlorine species (ACS) in physiological solutions: Secoisolariciresinol diglucoside (SDG) scavenges ACS - A novel mechanism of DNA radioprotection.

Science.gov (United States)

Mishra, Om P; Popov, Anatoliy V; Pietrofesa, Ralph A; Christofidou-Solomidou, Melpo

2016-09-01

Secoisolariciresinol diglucoside (SDG), the main lignan in whole grain flaxseed, is a potent antioxidant and free radical scavenger with known radioprotective properties. However, the exact mechanism of SDG radioprotection is not well understood. The current study identified a novel mechanism of DNA radioprotection by SDG in physiological solutions by scavenging active chlorine species (ACS) and reducing chlorinated nucleobases. The ACS scavenging activity of SDG was determined using two highly specific fluoroprobes: hypochlorite-specific 3'-(p-aminophenyl) fluorescein (APF) and hydroxyl radical-sensitive 3'-(p-hydroxyphenyl) fluorescein (HPF). Dopamine, an SDG structural analog, was used for proton (1)H NMR studies to trap primary ACS radicals. Taurine N-chlorination was determined to demonstrate radiation-induced generation of hypochlorite, a secondary ACS. DNA protection was assessed by determining the extent of DNA fragmentation and plasmid DNA relaxation following exposure to ClO(-) and radiation. Purine base chlorination by ClO(-) and γ-radiation was determined by using 2-aminopurine (2-AP), a fluorescent analog of 6-aminopurine. Chloride anions (Cl(-)) consumed >90% of hydroxyl radicals in physiological solutions produced by γ-radiation resulting in ACS formation, which was detected by (1)H NMR. Importantly, SDG scavenged hypochlorite- and γ-radiation-induced ACS. In addition, SDG blunted ACS-induced fragmentation of calf thymus DNA and plasmid DNA relaxation. SDG treatment before or after ACS exposure decreased the ClO(-) or γ-radiation-induced chlorination of 2-AP. Exposure to γ-radiation resulted in increased taurine chlorination, indicative of ClO(-) generation. NMR studies revealed formation of primary ACS radicals (chlorine atoms (Cl) and dichloro radical anions (Cl2¯)), which were trapped by SDG and its structural analog dopamine. We demonstrate that γ-radiation induces the generation of ACS in physiological solutions. SDG treatment scavenged

Pumping machinery theory and practice

CERN Document Server

Badr, Hassan M

2014-01-01

Pumping Machinery Theory and Practice comprehensively covers the theoretical foundation and applications of pumping machinery. Key features: Covers characteristics of centrifugal pumps, axial flow pumps and displacement pumpsConsiders pumping machinery performance and operational-type problemsCovers advanced topics in pumping machinery including multiphase flow principles, and two and three-phase flow pumping systemsCovers different methods of flow rate control and relevance to machine efficiency and energy consumptionCovers different methods of flow rate control and relevance to machine effi

Hopping models and ac universality

DEFF Research Database (Denmark)

Dyre, Jeppe; Schrøder, Thomas

2002-01-01

Some general relations for hopping models are established. We proceed to discuss the universality of the ac conductivity which arises in the extreme disorder limit of the random barrier model. It is shown that the relevant dimension entering into the diffusion cluster approximation (DCA) is the h......Some general relations for hopping models are established. We proceed to discuss the universality of the ac conductivity which arises in the extreme disorder limit of the random barrier model. It is shown that the relevant dimension entering into the diffusion cluster approximation (DCA......) is the harmonic (fracton) dimension of the diffusion cluster. The temperature scaling of the dimensionless frequency entering into the DCA is discussed. Finally, some open problems regarding ac universality are listed....

Numerical simulation of the self-pumped long Josephson junction using a modified sine-Gordon model

DEFF Research Database (Denmark)

Sobolev, A.; Pankratov, A.; Mygind, Jesper

2006-01-01

We have numerically investigated the dynamics of a long Josephson junction (flux-flow oscillator) biased by a DC current in the presence of magnetic field. The study is performed in the frame of the modified sine-Gordon model, which includes the surface losses, RC-load at both FFO ends and the self-pumping...... effect. In our model the dumping parameter depends both on the spatial coordinate and the amplitude of the AC voltage. In order to find the DC FFO voltage the damping parameter has to be calculated by successive approximations and time integration of the perturbed sine-Gordon equation. The modified model...

Transport AC losses in YBCO coated conductors

Energy Technology Data Exchange (ETDEWEB)

Majoros, M [Ohio State University, Columbus, OH 43210 (United States); Ye, L [IRC in Superconductivity, University of Cambridge, Madingley Road, Cambridge CB3 0HE (United Kingdom); Velichko, A V [IRC in Superconductivity, University of Cambridge, Madingley Road, Cambridge CB3 0HE (United Kingdom); Coombs, T A [IRC in Superconductivity, University of Cambridge, Madingley Road, Cambridge CB3 0HE (United Kingdom); Sumption, M D [Ohio State University, Columbus, OH 43210 (United States); Collings, E W [Ohio State University, Columbus, OH 43210 (United States)

2007-09-15

Transport AC loss measurements have been made on YBCO-coated conductors prepared on two different substrate templates-RABiTS (rolling-assisted biaxially textured substrate) and IBAD (ion-beam-assisted deposition). RABiTS samples show higher losses compared with the theoretical values obtained from the critical state model, with constant critical current density, at currents lower than the critical current. An origin of this extra AC loss was demonstrated experimentally by comparison of the AC loss of two samples with different I-V curves. Despite a difference in I-V curves and in the critical currents, their measured losses, as well as the normalized losses, were practically the same. However, the functional dependence of the losses was affected by the ferromagnetic substrate. An influence of the presence of a ferromagnetic substrate on transport AC losses in YBCO film was calculated numerically by the finite element method. The presence of a ferromagnetic substrate increases transport AC losses in YBCO films depending on its relative magnetic permeability. The two loss contributions-transport AC loss in YBCO films and ferromagnetic loss in the substrate-cannot be considered as mutually independent.

Solar heating by radiant floor: Experimental results and emission reduction obtained with a micro photovoltaic–heat pump system

International Nuclear Information System (INIS)

Izquierdo, M.; Agustín-Camacho, P. de

2015-01-01

Highlights: • This work presents a PVT multicrystalline solar heating system for buildings. • The PV DC electricity generated was converted to AC to drive an air–water heat pump. • Experimental results obtained from December 1, 2012 to April 30, 2013 are detailed. • An environmental study is also presented. - Abstract: An experimental research with a solar photovoltaic thermal (PVT) micro grid feeding a reversible air–water, 6 kW heating capacity heat pump, has been carried out from December 2012 to April 2013. Its purpose is to heat a laboratory that is used as a house prototype for the study of heating/cooling systems. It was built in accordance with the 2013 Spanish CTE, and has an area of 35 m 2 divided into two internal rooms: one of them housing the storage system, the solar controller, the inverter and the control system; the other one is occupied by three people. Its main thermal characteristics are: UA = 125 W/°C and a maximum thermal load about 6.0 kW at the initial time. The PVT field consists of 12 modules, with a total area of 15.7 m 2 and useful area of 14 m 2 . Each module is composed of 48 polycrystalline silicon cells of 243.4 cm 2 , which with a nominal efficiency 14% can generate a power of 180 W, being the total nominal power installed 2.16 kW. The PV system stores electricity in 250 Ah batteries from where is converted from DC to AC through a 3.0 kW inverter that feeds the heat pump. This works supplying 840 l/h of hot water at 35–45 °C to the radiant floor. The data storing system is recording variables such as solar radiation; temperatures; input power to batteries; heat produced; heat transferred by the radiant floor; heat pump’s COP; isolated ratio; and solar fraction. The objective of this work is to present and discuss the experimental results and the emission reduction of CO 2 obtained during the period from 01/12/2012 to 30/04/2013, including the detailed results of two representative days of Madrid’s climate: 28

Hydraulic optimization of 'S' characteristics of the pump-turbine for Xianju pumped storage plant

International Nuclear Information System (INIS)

Liu, W C; Zheng, J S; Cheng, J; Shi, Q H

2012-01-01

The pump-turbine with a rated power capacity of 375MW each at Xianju pumped storage plant is the most powerful one under construction in China. In order to avoid the instability near no-load conditions, the hydraulic design of the pump-turbine has been optimized to improving the 'S' characteristic in the development of the model pump-turbine. This paper presents the cause of 'S' characteristic of a pump-turbine by CFD simulation of the internal flow. Based on the CFD analysis, the hydraulic design optimization of the pump-turbine was carried out to eliminate the 'S' characteristics of the machine at Xianju pumped storage plant and a big step for removing the 'S' characteristic of a pump-turbine has been obtained. The model test results demonstrate that the pump-turbine designed for Xianju pumped storage plant can smoothly operate near no-load conditions without an addition of misaligned guide vanes.

Expression Study of LeGAPDH, LeACO1, LeACS1A, and LeACS2 in Tomato Fruit (Solanum lycopersicum

Directory of Open Access Journals (Sweden)

Pijar Riza Anugerah

2015-10-01

Full Text Available Tomato is a climacteric fruit, which is characterized by ripening-related increase of respiration and elevated ethylene synthesis. Ethylene is the key hormone in ripening process of climacteric fruits. The objective of this research is to study the expression of three ethylene synthesis genes: LeACO1, LeACS1A, LeACS2, and a housekeeping gene LeGAPDH in ripening tomato fruit. Specific primers have been designed to amplify complementary DNA fragment of LeGAPDH (143 bp, LeACO1 (240 bp, LeACS1A (169 bp, and LeACS2 (148 bp using polymerase chain reaction. Nucleotide BLAST results of the complementary DNA fragments show high similarity with LeGAPDH (NM_001247874.1, LeACO1 (NM_001247095.1, LeACS1A (NM_001246993.1, LeACS2 (NM_001247249.1, respectively. Expression study showed that LeACO1, LeACS1A, LeACS2, and LeGAPDH genes were expressed in ripening tomato fruit. Isolation methods, reference sequences, and primers used in this study can be used in future experiments to study expression of genes responsible for ethylene synthesis using quantitative polymerase chain reaction and to design better strategy for controlling fruit ripening in agroindustry.

Pump integrated closed loop control. The intelligent actuator pump - state of the art and perspectives; Pumpenintegrierte Prozessregelung. Der intelligente Aktor Pumpe - Stand und Moeglichkeiten

Energy Technology Data Exchange (ETDEWEB)

Paulus, Thomas; Schullerer, Joachim; Oesterle, Manfred [KSB AG, Frankenthal (Germany)

2009-07-01

In many areas of industrial automation, centrifugal pumps and systems of centrifugal pumps are important actuators of a process und therefore a fundamental part of the entire plant. In contrary to the controlled valves, located behind the pump in the pipework system, the functions of the intelligent actuator pump or system of pumps are rarely used and noticed. With regard to the reduction of life cycle costs of the asset pump, pump integrated closed loop control of the fluid transport task has advantages over central closed loop control e.g. in a process control system. This article contains a survey of the intelligent actuator pump, its structure and functions with regard to the solution of the fluid transport task and according pump integrated closed loop control. (orig.)

High-vacuum pumping out of hydrogen isotopes by compressed and electrophysical pumps

International Nuclear Information System (INIS)

Bychkova, A.D.; Ershova, Z.V.; Saksaganskij, G.L.; Serebrennikov, D.V.

1982-01-01

To explain the selection of parameters of vacuum systems of projected thermonuclear devices, experiments are performed on the pumping-out of deuterium and tritium by high-vacuum pumps of different types. The values of the fast response of turbomolecular, diffusion vapour-mercury, magneto-discharge and titanium getter pumps in the operation pressure range are determined. The rate of sorption of hydrogen isotopes by non-spraying gas absorber of cial alloy depending on the amount of the gas absorbed and temperature, is measured. Gas current is determined by the pressure drop on the diagram of the known conductivity. Individual calibration of manometric converters for different gases using a mercury burette is performed preliminarily. The means of high-vacuum pumping-out that have been studied have the following values of fast response for tritium (relatively to protium): turbomolecular pump-0.95; evaporation getter pump-0.25; magneto-discharge pumps-0.65-0.9; cial alloy-0.1...0.5

Measure Guideline: Replacing Single-Speed Pool Pumps with Variable Speed Pumps for Energy Savings

Energy Technology Data Exchange (ETDEWEB)

Hunt, A.; Easley, S.

2012-05-01

The report evaluates potential energy savings by replacing traditional single-speed pool pumps with variable speed pool pumps, and provide a basic cost comparison between continued uses of traditional pumps verses new pumps. A simple step-by-step process for inspecting the pool area and installing a new pool pump follows.

Wet motor geroter fuel pump

Energy Technology Data Exchange (ETDEWEB)

Wiernicki, M.V.

1987-05-05

This patent describes a wet motor gerotor fuel pump for pumping fuel from a fuel source to an internal combustion which consists of: gerotor pump means comprising an inner pump gear, an outer pump gear, and second tang means located on one of the inner and outer pump gears. The second tang means further extends in a second radial direction radially offset from the first radial direction and forms a driving connection with the first tang means such that the fuel pump pumps fuel from the fuel source into the narrow conduit inlet chamber, through the gerotor pump means past the electric motor means into the outlet housing means substantially along the flow axis to the internal combustion engine.

Pump failure leads to alternative vertical pump condition monitoring technique

International Nuclear Information System (INIS)

DeVilliers, Adriaan; Glandon, Kevin

2011-01-01

Condition monitoring and detecting early signs of potential failure mechanisms present particular problems in vertical pumps. Most often, the majority of the pump assembly is not readily accessible for visual or audible inspection or conventional vibration monitoring techniques using accelerometers and/or proximity sensors. The root cause failure analysis of a 2-stage vertical centrifugal service-water pump at a nuclear power generating facility in the USA is presented, highlighting this long standing challenge in condition monitoring of vertical pumps. This paper will summarize the major findings of the root cause analysis (RCA), highlight the limitations of traditional monitoring techniques, and present an expanded application of motor current monitoring as a means to gain insight into the mechanical performance and condition of a pump. The 'real-world' example of failure, monitoring and correlation of the monitoring technique to a detailed pump disassembly inspection is also presented. This paper will explain some of the reasons behind well known design principles requiring natural frequency separation from known forcing frequencies, as well as explore an unexpected submerged brittle fracture failure mechanism, and how such issues may be avoided. (author)

Diode-pumped laser with improved pumping system

Science.gov (United States)

Chang, Jim J.

2004-03-09

A laser wherein pump radiation from laser diodes is delivered to a pump chamber and into the lasing medium by quasi-three-dimensional compound parabolic concentrator light channels. The light channels have reflective side walls with a curved surface and reflective end walls with a curved surface. A flow tube between the lasing medium and the light channel has a roughened surface.

Optically pumped atoms

CERN Document Server

Happer, William; Walker, Thad

2010-01-01

Covering the most important knowledge on optical pumping of atoms, this ready reference is backed by numerous examples of modelling computation for optical pumped systems. The authors show for the first time that modern scientific computing software makes it practical to analyze the full, multilevel system of optically pumped atoms. To make the discussion less abstract, the authors have illustrated key points with sections of MATLAB codes. To make most effective use of contemporary mathematical software, it is especially useful to analyze optical pumping situations in the Liouville spa

Dicty_cDB: FC-AC21 [Dicty_cDB

Lifescience Database Archive (English)

Full Text Available FC (Link to library) FC-AC21 (Link to dictyBase) - - - Contig-U15104-1 FC-AC21E (Li...nk to Original site) - - - - - - FC-AC21E 527 Show FC-AC21 Library FC (Link to library) Clone ID FC-AC21 (Link to dict...yBase) Atlas ID - NBRP ID - dictyBase ID - Link to Contig Contig-U15104-1 Original site URL http://dict...ce KDSLDVIIFPEMVKLVGLTPNTMEKVLTYFQDNDTIDLSTFPMEIQVEQLSGKYIFICTH KQKDQRCGYCGPILVDQLRDQIKERSLEKEIQVFGTSHVGGHKY... Frames) Frame A: KDSLDVIIFPEMVKLVGLTPNTMEKVLTYFQDNDTIDLSTFPMEIQVEQLSGKYIFICTH KQ

Outcome of Cardiac Rehabilitation Following Off-Pump Versus On-Pump Coronary Bypass Surgery

Directory of Open Access Journals (Sweden)

Reza Arefizadeh

2017-05-01

CONCLUSIONS: Regarding QOL and psychological status, there were no differences in the CR outcome between those who underwent off-pump bypass surgery and those who underwent on-pump surgery; nevertheless, the off-pump technique was superior to the on-pump method on METs improvement following CR.

Measure Guideline. Replacing Single-Speed Pool Pumps with Variable Speed Pumps for Energy Savings

Energy Technology Data Exchange (ETDEWEB)

Hunt, A. [Building Media and the Building America Retrofit Alliance (BARA), Wilmington, DE (United States); Easley, S. [Building Media and the Building America Retrofit Alliance (BARA), Wilmington, DE (United States)

2012-05-01

This measure guideline evaluates potential energy savings by replacing traditional single-speed pool pumps with variable speed pool pumps, and provides a basic cost comparison between continued uses of traditional pumps verses new pumps. A simple step-by-step process for inspecting the pool area and installing a new pool pump follows.

THERMIONIC AC GENERATION

Science.gov (United States)

is shown that the maximum ac efficiency is equal to approximately 70% of the corresponding dc value. An illustrative example, including a proposed design for a rather unconventional transformer, is appended. (Author)

Pumps for nuclear facilities

International Nuclear Information System (INIS)

1999-01-01

The guide describes how the Finnish Radiation and Nuclear Safety Authority (STUK) controls pumps and their motors at nuclear power plants and other nuclear facilities. The scope of the control is determined by the Safety Class of the pump in question. The various phases of the control are: (1) review of construction plan, (2) control of manufacturing, and construction inspection, (3) commissioning inspection, and (4) control during operation. STUK controls Safety Class 1, 2 and 3 pumps at nuclear facilities as described in this guide. STUK inspects Class EYT (non-nuclear) pumps separately or in connection with the commissioning inspections of the systems. This guide gives the control procedure and related requirements primarily for centrifugal pumps. However, it is also applied to the control of piston pumps and other pump types not mentioned in this guide

21 CFR 880.6320 - AC-powered medical examination light.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false AC-powered medical examination light. 880.6320... Miscellaneous Devices § 880.6320 AC-powered medical examination light. (a) Identification. An AC-powered medical examination light is an AC-powered device intended for medical purposes that is used to illuminate body...

Detection of pump degradation

International Nuclear Information System (INIS)

Greene, R.H.; Casada, D.A.; Ayers, C.W.

1995-08-01

This Phase II Nuclear Plant Aging Research study examines the methods of detecting pump degradation that are currently employed in domestic and overseas nuclear facilities. This report evaluates the criteria mandated by required pump testing at U.S. nuclear power plants and compares them to those features characteristic of state-of-the-art diagnostic programs and practices currently implemented by other major industries. Since the working condition of the pump driver is crucial to pump operability, a brief review of new applications of motor diagnostics is provided that highlights recent developments in this technology. The routine collection and analysis of spectral data is superior to all other technologies in its ability to accurately detect numerous types and causes of pump degradation. Existing ASME Code testing criteria do not require the evaluation of pump vibration spectra but instead overall vibration amplitude. The mechanical information discernible from vibration amplitude analysis is limited, and several cases of pump failure were not detected in their early stages by vibration monitoring. Since spectral analysis can provide a wealth of pertinent information concerning the mechanical condition of rotating machinery, its incorporation into ASME testing criteria could merit a relaxation in the monthly-to-quarterly testing schedules that seek to verify and assure pump operability. Pump drivers are not included in the current battery of testing. Operational problems thought to be caused by pump degradation were found to be the result of motor degradation. Recent advances in nonintrusive monitoring techniques have made motor diagnostics a viable technology for assessing motor operability. Motor current/power analysis can detect rotor bar degradation and ascertain ranges of hydraulically unstable operation for a particular pump and motor set. The concept of using motor current or power fluctuations as an indicator of pump hydraulic load stability is presented

Detection of pump degradation

Energy Technology Data Exchange (ETDEWEB)

Greene, R.H.; Casada, D.A.; Ayers, C.W. [and others

1995-08-01

This Phase II Nuclear Plant Aging Research study examines the methods of detecting pump degradation that are currently employed in domestic and overseas nuclear facilities. This report evaluates the criteria mandated by required pump testing at U.S. nuclear power plants and compares them to those features characteristic of state-of-the-art diagnostic programs and practices currently implemented by other major industries. Since the working condition of the pump driver is crucial to pump operability, a brief review of new applications of motor diagnostics is provided that highlights recent developments in this technology. The routine collection and analysis of spectral data is superior to all other technologies in its ability to accurately detect numerous types and causes of pump degradation. Existing ASME Code testing criteria do not require the evaluation of pump vibration spectra but instead overall vibration amplitude. The mechanical information discernible from vibration amplitude analysis is limited, and several cases of pump failure were not detected in their early stages by vibration monitoring. Since spectral analysis can provide a wealth of pertinent information concerning the mechanical condition of rotating machinery, its incorporation into ASME testing criteria could merit a relaxation in the monthly-to-quarterly testing schedules that seek to verify and assure pump operability. Pump drivers are not included in the current battery of testing. Operational problems thought to be caused by pump degradation were found to be the result of motor degradation. Recent advances in nonintrusive monitoring techniques have made motor diagnostics a viable technology for assessing motor operability. Motor current/power analysis can detect rotor bar degradation and ascertain ranges of hydraulically unstable operation for a particular pump and motor set. The concept of using motor current or power fluctuations as an indicator of pump hydraulic load stability is presented.

Survey of pumps for tritium gas

International Nuclear Information System (INIS)

Dowell, T.M.

1983-05-01

This report considers many different types of pumps for their possible use in pumping tritium gas in the low, intermediate and high vacuum ranges. No one type of pump is suitable for use over the wide range of pumping pressure required in a typical pumping system. The favoured components for such a system are: bellows pump (low vacuum); orbiting scroll pump (intermediate vacuum); magnetically suspended turbomolecular pump (high vacuum); cryopump (high vacuum). Other pumps which should be considered for possible future development are: mound modified vane pump; SRTI wobble pump; roots pump with canned motor. It is proposed that a study be made of a future tritium pumping system in a Canadian tritium facility, e.g. a tritium laboratory

Ac-dc converter firing error detection

International Nuclear Information System (INIS)

Gould, O.L.

1996-01-01

Each of the twelve Booster Main Magnet Power Supply modules consist of two three-phase, full-wave rectifier bridges in series to provide a 560 VDC maximum output. The harmonic contents of the twelve-pulse ac-dc converter output are multiples of the 60 Hz ac power input, with a predominant 720 Hz signal greater than 14 dB in magnitude above the closest harmonic components at maximum output. The 720 Hz harmonic is typically greater than 20 dB below the 500 VDC output signal under normal operation. Extracting specific harmonics from the rectifier output signal of a 6, 12, or 24 pulse ac-dc converter allows the detection of SCR firing angle errors or complete misfires. A bandpass filter provides the input signal to a frequency-to-voltage converter. Comparing the output of the frequency-to-voltage converter to a reference voltage level provides an indication of the magnitude of the harmonics in the ac-dc converter output signal

Novel Technique to improve the pH of Acidic Barren Soil using Electrokinetic-bioremediation with the application of Vetiver Grass

Science.gov (United States)

Azhar, A. T. S.; Nabila, A. T. A.; Nurshuhaila, M. S.; Zaidi, E.; Azim, M. A. M.; Zahin, A. M. F.

2016-11-01

Residual acidic slopes which are not covered by vegetation greatly increases the risk of soil erosion. In addition, low soil pH can bring numerous problems such as Al and Fe toxicity, land degradation issues and some problems related to vegetation. In this research, a series of electrokinetic bioremediation (EK-Bio) treatments using Bacillus sphaericus, Bacillus subtilis and Pseudomonas putida with a combination of Vetiver grass were performed in the laboratory. Investigations were conducted for 14 days and included the observation of changes in the soil pH and the mobilization of microorganism cells through an electrical gradient of 50 V/m under low pH. Based on the results obtained, this study has successfully proven that the pH of soil increases after going through electrokinetic bioremediation (EK-Bio). The treatment using Bacillus sphaericus increases the pH from 2.95 up to 4.80, followed by Bacillus subtilis with a value of 4.66. Based on the overall performance, Bacillus sphaericus show the highest number of bacterial cells in acidic soil with a value of 6.6 × 102 cfu/g, followed by Bacillus subtilis with a value of 5.7 × 102 cfu/g. In conclusion, Bacillus sphaericus and Bacillus subtilis show high survivability and is suitable to be used in the remediation of acidic soil.

Vertical pump assembly

International Nuclear Information System (INIS)

Dohnal, M.; Rosel, J.; Skarka, V.

1988-01-01

The mounting is described of the drive assembly of a vertical pump for nuclear power plants in areas with seismic risk. The assembly is attached to the building floor using flexible and damping elements. The design allows producing seismically resistant pumps without major design changes in the existing types of vertical pumps. (E.S.). 1 fig