Abstracts of 2001 Annual Meeting the Institute of Electrostatics Japan

Presentation Number: 11aA-1

Title: Fundamental Characteristics of Positive Corona Discharge in Needle-to-Plane Electrode System

Authors and Affiliation: Seishu SHIMAMOTO*, Shuichi AKAMINE*, Seiji KANAZAWA*, Toshikazu OHKUBO*, Yukiharu NOMOTO*, Jerzy MIZERACZYK*　　*Department of Electrical and Electronic Engineering, Oita University, ** Institute of Fluid Flow Machinery, Polish Academy of Sciences

Abstract: In this study, corona current distributions at the plane electrode of dc positive needle-to-plane corona discharge were measured. Glow corona and streamer corona were produced separately by changing the needle electrodes. As a result, the current distribution of glow discharge was in good agreement with the well- known Warburg distribution. While, the current distribution of streamer corona discharge was sharper and narrower than that of glow discharge. For a fixed total current, the centerline current density of streamer discharge was high compared to that of glow discharge.

Presentation Number: 11aA-2

Title: Electric Field Strength and Surface Charge Density for Initiating Electrostatic Discharges between Charged Insulating Disks

Authors and Affiliation: Mitsuru MATSUI* and Koichi FUJIBAYASHI**　　*Zao ES Laboratory,**Department of Electrical and Electronic Engineering, Tokyo University of Agriculture and Technology

Abstract: Electrostatic discharges between charged insulating disks have been observed using spherical induction electrodes, and electric field strength between the disks has been calculated. Supposing the electrostatic discharge obeys Paschen criterion, the minimum surface charge density initiating the electrostatic discharge between the disks set at a spacing of 3 mm can be estimated as approximately 47 micro-coulombs per square meter that agrees with the experimental observation.

Presentation Number: 11aA-3

Title: Measurement of charge transferred by a partial discharge

Authors and Affiliation: Seiya　OGAWA　　Tokyo University of Agriculture and Technology

Abstract: A dielectric sheet is inserted between sphere and plane electrodes. The sheet is acrylic (0.5mm in thickness), and the gap between the sphere and the sheet is 50μm. A ramp voltage (rise rate: 40V/sec) is applied, and the voltage is cut-off when a discharge pulse is detected. The sheet after the discharge is put into a faraday cage, and amount of the charge is measured. Black-red powder (tonor for electrophotography) is sprinkled over the surface of sheet, and distribution of the charge is made visible. The ring powder figures appear for both applications of positive and negative voltages. When positive voltage is applied to the sphere electrode, the discharge inception voltage is 2.3kV, and the charge measured is 694pC. For negative voltage application the discharge inception voltage is -2.2kV, and the charge measured is -158pC. Thus the charge transferred by the partial discharge for the positive application is larger (more than twice) than that for the negative application. The result measured will be useful, also for the study of the charging roller system of electrophotography.

Presentation Number: 11aA-4

Title: Electrostatic Discharge in Short Air Gap. �U-Effect of surface roughness of electrode-

Authors and Affiliation: Noriaki MASUI, Shinichi TAMAMURA　　Faculty of Engineering, Science University of Tokyo

Abstract: This paper describes the dependence of dispersion of spark gap length on the surface roughness of spherical electrodes. Approaching speed between the electrodes is 0.4mm/s. Material of the electrode is brass and its diameter is 20mm. Electrode is roughened by abrading with polishing powder (mixture of iron and glass particles). Mean particle sizes of polishing powder are 595μm (#30), 177μm (#80) and 74μm (#150). The electrode which surface is not roughened with polishing powder is also used. Positive 6kV is applied to the high voltage electrode and ceramic condenser of 100pF is connected to the electrode. The spark gap length increases with increasing surface roughness. Peak current is reduced with increasing the spark gap length. When the spark occurs at the same gap length, waveform of discharge current shows almost the same shape and peak current is almost the same value for the changes in the surface roughness of the electrode and the relative humidity in the discharge region. The spark gap length strongly depends on the surface roughness of negative electrode.

Presentation Number: 11aA-5

Title: On the Computing Programs of Electric FieldandSparkover Voltage in Standard Sphere Gaps

Authors and Affiliation: Yasuo　NISHIKORI　　Faculty of Engineering, Kogakuin University

Abstract: Although sparkover and corona starting voltages can be satisfactorily predetermined when empirical formulas or curves are available, a more general applicable method is required. An approach to such a method is through a modification of streamer theory, which, though possibly lacking in rigor, suffices in many cases for the accurate criterion of the breakdown voltages. The criterion by Pedersen in 1967 for air in standard sphere gaps was not entirely successful because of inadequate knowledge of the axial field distribution in gap spacing, but a deficiency is now remedied by the use of modification of the charge simulation method, taking account of the influences of both the shanks and the earthed plane.

Presentation Number: 11aA-6

Title: A Computer-Supported System for Electric Field Analysis by Using WWW Environment

Authors and Affiliation: Ryo NISHIMURA　　Tottori University

Abstract: In this paper we propose a remote electric field analysis system using the Internet environment. Recently, Internet becomes one of strong methods for information providing and sharing. Information sharing is important to improve technologies and engineering. Authorsユ have been proposed a method to calculate electric field distributions around cylindrical electrodes by using charge simulation method assisted genetic algorithms. In this research, the electrical field calculation program is executed from the web page by using the WWW (World Wide Web) environment and CGI (Common Gate Interface) program. A client keys numerical conditions for the calculation into the input column on the web page. The CGI program receives the data and sends them to the electric field calculation program in the server computer. The client can obtain the numerical results, the positions of the fictitious charges and the contour points and the potential distribution around the electrodes, as a format of comma-delimited text file. We show an example of a method to share a technique on electrostatic analyses by using Internet.

Presentation Number: 11aA-7

Title: Studies on Electric Discharge in High-Intensity Acoustical Standing wave Field −Examination from a Current waveform−

Authors and Affiliation: Tatsutoshi SHINJO, Yuusuke NAGAI, Tetsuro OTSUKA and Tomoo NAKANE　　College of Industrial Technology, Nihon University

Abstract: It is published that the high sound energy affected to the discharging phenomena,such as influence the luminous part of the discharge. In this paper, the current waveform was measured by a digital oscilloscope in high intensity ultrasound field,the cycle and the peak value of the current wave produced a change by submitting sound pressure.

Presentation Number: 11aA-8

Title: Positive Corona Discharge at Disruption of Air Bubble under a DC Field

Authors and Affiliation: Yoshio Higashiyama, Hideyuki Kato, Toshiyuki Sugimoto and Yasushi Minamitani　　Faculty of engineering, Yamagata University

Abstract: Corona discharge from a water jet generated in burst of air bubble at water surface has been investigated under a negative electric field. Water droplets were ejected from the tip of the water jet. Positive corona discharge occurred intermittently from the tip of the water jet. The waveform of corona current was typical burst pulse. The influence of surface tension and conductivity of water on formation of water jet and on corona discharge was confirmed. The surface tension varies with temperature. Air bubble in water with lower emperature forms a water jetrapidly and disrupts relatively earlier than that with higher temperature. The magnitude of corona current from a water jet with higher conductivity is smaller than that with lower one.

Presentation Number: 11aA-9

Title: Influence of the ultrasonic wave exerted in water electric discharge

Authors and Affiliation: Yuusuke Nagai, Tatsutosi Shinjo, Tetsurou Otsuka, Tomoo Nakane　　College of Industrial Technology, Nihon University

Abstract: It has been published that a luminous part of a discharge in gaseous media is influenced by an ultrasound energy, but no data in liquid medium. In this paper, the discharge phenomena was experimented in a water with the ultrasound energyat 38 kHz, an applied voltage of the discharge was measured. As a result, the discharge phenomena in the liquid medium was influenced by the ultrasound energy.

Presentation Number: 11aB-1

Title: Comparison of OH behavior in pulsed corona and barrier discharge

Authors and Affiliation: Ryo ONO, Tetsuji ODA　　Department of Electrical Engineering, School of Engineering, the University of Tokyo

Abstract: Production and temporal decay of OH radical were compared between pulsed corona and pulsed dielectric barrier discharge (DBD). OH was measured by laser-induced fluorescence (LIF). The OH production process was different between the two discharges. Under DBD, charging current yielded OH, while charging current did not contribute to OH generation in corona discharge. The net current, given by discharge current minus charging current, yielded OH under corona discharge. As oxygen concentration raised, OH density increased. The rate of increase was nearly equal among positive and negative DBD, and positive corona. In negative corona, only a trace amount of OH was generated. The OH yield per discharge energy was determined. It was in the order of 10(13) cm(-3)/mJ. When trichloroethylene (TCE) was added to environment gas, OH density became considerably small in corona discharge. It was decreased to about 10% by addition of 300 ppm of TCE. On the other hand, OH density was almost constant in DBD when TCE was added up to 1000 ppm.

Presentation Number: 11aB-2

Title: Observation of NO Molecule in DC Streamer Coronas by Laser-Induced Fluorescence (II)

Authors and Affiliation: Yasuyuki SHUTO*, Naruaki SATO*, Seiji KANAZAWA*, Toshikazu OHKUBO*, Yukiharu NOMOTO*, Jerzy MIZERACZYK**　　* Department of Electrical and Electronic Engineering, Oita University,

** Institute of Fluid Flow Machinery, Polish Academy of Sciences

Abstract: Non-thermal plasma chemical processing for NOx removal has been studied in terms of both numerically by using plasma chemical models and experimentally. However, there is no sufficient plasma chemical process model which can describe the NOx removal process in a reactor. In this study, a laser induced fluorescence (LIF) method was employed for the observation of NO molecule dynamics during the NOx removal. In order to monitor the ground-state NO molecules, NO (X2Π(v''=0)→ A2Σ+(v'=0)) transition at 226nm was used. As a result, two-dimensional distributions of NO concentration in the reactor were determined as a function of operational time in NOx removal. The obtained results showed that the density of NO molecule decreased not only in the plasma region formed by the corona streamers but also in both the upstream and downstream regions of the reactor.

Presentation Number: 11aB-3

Title: Emission Spectroscopy of NO in Atmospheric Pressure Corona Discharge

Authors and Affiliation: Kazuo　Shimizu, Shusuke Saeki and Tetsuji Oda　　The University of Tokyo

Abstract: Emission spectrometry in the atmospheric pressure discharge was carried out to understand reaction mechanisms of active species, as the discharge plasma processing is significantly affected by the gas components. In this research, N2 second positive band and two band systems of NO such as NO-b band and NO-g band were investigated by using a digital controlled spectrometer and an ICCD camera. When the dielectric pellets were placed on the needle-plate type electrode, emissions from both N2 second positive band and NO-g band were declined along with the electrode axis. Observation by the time resolution of the emission spectrum resulted that N2 second positive band emission was extinguished within 200 nanoseconds, while that from NO-g band continued more than 1 microsecond. From these results, distribution of NO concentration in the corona discharge or barrier discharge was obtaine

Presentation Number: 11aB-4

Title: Measurement of atomic oxygen radical anion around atmospheric pressure by optogalvanic method

Authors and Affiliation: Yukimasa BABA, Masateru NISHIOKA, Masayoshi SADAKATA　　Faculty of Engineering, University of Tokyo

Abstract: Plasma discharge under atmospheric pressure has been applied in various fields, e.g. removal of air pollutant and plasma sterilization. However, the discharge mechanism has not been made clear because of the difficulty of measuring the intermediate-species in plasma at atmospheric pressure. In this study, atomic oxygen anion radical (O-) was measured by optogalvanic method in 2.6×102Pa to 2.0×103Pa and the density of negative ions was obtained in 3.7×102Pa. In this method, quenching of detached electrons cause large experimental error. Therefore the quenching process was estimated by calculation (including 42 element reactions). As the result, quantity of quenching electrons is below 0.1% and negative ions can be detected under the atmospheric pressure condition by this method.

Presentation Number: 11aB-5

Title: Decomposition of Dilute Trichloroethylene using Indirect Discharge Plasma

Authors and Affiliation: ○Kei YAMAJI, Tetsuji ODA and Tadashi TAKAHASHI　　The University of Tokyo

Abstract: Decomposition of dilute trichloroethylene (TCE) in air or O2/Ar gas was studied by using Indirect Non-Thermal Plasma. Indirect means to decompose by mixing with plasma processed clean air and TCE contaminated air. The reactor is a bolt type of 13.0mm inner diameter and is excited at 50Hz. TCE was decomposed by mixing with plasma processed O2/Ar gas. Although O radical generated by O3 ecomposition was assumed to react with TCE, O radical didn't affect TCE removal because O3 concentration didn't change after discharge. The relation of the humidiy and TCE decompostion was also experimentally studied. The decomposition efficiency of TCE was decreased by adding water where the humidity was roughly 90%.

Presentation Number: 11aB-6

Title: Decomposition of Trichloroethylene by using SPCP reactor

Authors and Affiliation: ○Nobuo HARADA, Tatsushi MATSUYAMA, Hideo YAMAMOTO　　Faculty of Engineering, Soka University

Abstract: We developed a new efficient apparatus for gas treatment in which a ceramic filter and SPCP (Surface corona discharge induced Plasma Chemical Process) were combined. SPCP is a method to activate gas-phase chemical reactions with surface discharge plasma. In this study, an applicability of the reactor to decomposition of trichloroethylene (TCE) was tested. The efficiency was examined against various conditions of initial concentration of TCE, with some kinds of carrier gases (air, nitrogen, and mixture of nitrogen and oxygen or water vapor and argon). TCE was removed with every condition effectively. When the carrier gas included oxygen source, the efficiency was higher than that with the nitrogen carrier. In particular, TCE was completely decomposed with discharge power of only 1W when the carrier gas was argon. The major parts of reaction products were measured and identified as inorganic compounds as hydrogen chloride, chlorine and carbon dioxide.

Presentation Number: 11aB-7

Title: Decomposition of Dilute Trichloroethylene using Non-Thermal Discharge Plasma with Catalysis

Authors and Affiliation: ○Kei YAMAJI, Yasuhisa TOKUDA, Tetsuji ODA and Tadashi TAKAHASHI　　The University of Tokyo

Abstract: Trichloroethylene (TCE) decomposition was investigated experimentally by using Non-Thermal Discharge Plasma with catalysis.

TCE removal with various catalyst, such as TiO2, V2O5/TiO2 (0.1wt%, 1.0wt%, 4.0wt%), MnO2, were tested. TCE removal rate was increased by synergistic effects of plasma excitation and catalytic activation, especially V2O5/TiO2 (1.0wt%) was the most efficiency. The effect of O radical generated from O3 decomposed by MnO2 on TCE removal was also experimentally studied. TCE decomposition efficiency was improved by using MnO2 in indirect plasma process.

Presentation Number: 11aB-8

Title: Characteristics of a Screen Type Ozonizer with Rod-to-Rod Electrodes

Authors and Affiliation: Yukiharu NOMOTO, Shuichi AKAMINE, Seiji KANAZAWA,Toshikazu OHKUBO　　Department of Electrical and Electronic Engineering, Oita University

Abstract: The silent discharge is mainly used for ozone generation in an ozonizer. Most practical ozonizer has a coaxial cylindrical electrode system with a gap of 1-2mm spacing and 1-2m length. In this study, instead of conventional coaxial cylindrical electrode system, a rod-to-rod electrode system is used. The tested ozonizer consists of nine units of the electrode system which are mounted in parallel in a box type reactor. The screen type uniform discharge can be obtained.in this ozonizer The effect of the number of electrode screen on ozone generation efficiency is investigated experimentally. As a result, the ozone generation efficiency is improved up to 15% higher by three electrode screens than that of one electrode screen.

Presentation Number: 11aB-9

Title: Dilute PFC Decomposition by the Non-Thermal Plasma

Authors and Affiliation: Tetsuji ODA and Mitsuko ITOH　　School of Engineering, the University of Tokyo

Abstract: For semiconductor process, various kind of PFCs (perfluorocarbon) are used now. It was found that PFCs also have strong green house effect and those emission into the air must be limited. Absolute concentration of PFC is very small and must be concentrated. A total gas pressure must be more than atmospheric pressure, otherwise that cannot release into air. The authors tried to decompose those PFCs by the non-thermal plasma of the barrier discharge and others. Considering the real condition and practical decomposition mechanism, CF4 in nitrogen or in synthesized air (80 % N2 and 20 % O2). Compared with the TCE decomposition, higher energy must be injected in order to decompose PFCs.

Presentation Number: １１aC-1

Title: DNA Sequencing Based on Molecular Surgery - Improvement of Yield -

Authors and Affiliation: Osamu Kurosawa1, 2, 3, Hiroyuki Kabata3 and Masao Washizu3　　1BRAIN (Seiken-Kiko), 2Advance Co., 3Kyoto University

Abstract: In DNA sequencing based on molecular surgery, 1) DNA is first stretched and immobilized onto a solid surface, 2) desired portion of the DNA is dissected and picked up, 3) an adapter sequence is ligated to the both ends of the dissected fragments, 4) the fragments are PCR amplified making use of the adapter sequence, and 5) the sequencing of the fragment is done with conventional biochemical methods. The processes 1) and 2) have been demonstrated in previous work by the authors, however, the number of obtained fragments appeared to be a factor of ten smaller than what is needed for the ligation process 3). There is adequate number of DNA molecules physically aligned in 1), but a large portion of them seemed to be damaged during the subsequent processes. In this paper, we show that the main mechanism for the loss is due to DNA damages a) by the fluorescence dyes when the labeled DNA is dried, and b) by the light irradiation for fluorescence excitation, which are needed for visualization during the molecular surgery. To avoid such damages, we adopted a new DNA labeling method, where fluorophores are introduced only to the molecular ends. This is done by the 3' to 5' digestion of DNA, followed by the incorporation of FITC-dUTP by a DNA polymerase. It yields the fluorescence bright enough so that the excitation can be reduced to 1/16 compared with what was used in the previous experiments. It is experimentally shown that adequate number of fragments can be obtained using the new method. Keywords: molecular surgery, DNA, dissection, sequencing, fluorescence labeling

Presentation Number: 11aC-2

Title: Development of Globule-coil State DNA Transition Technique

using Micro Needle Electrode

Authors and Affiliation: Jun KOMATSU, Shun-ichi MATSUURA, Tomonari SATO, Kazunori TAKASHIMA, Yukio MATSUZAWA, Shinji KATSURA, and Akira MIZUNO

　　Department of Ecological Engineering, Toyohashi University of Technology

Abstract: Fluorescent observation of a single DNA molecule may assist genetic analysis and gene mapping, etc, however these methods require an advanced micro manipulation technique which recovers a single DNA molecule from the sample solution, and fixes in a stretched form. Moreover, large DNA molecules are easily broken down by shear stress in the solution, therefore coiled DNA should be converted to globular DNA. This globular DNA can be reverted to original coil state by exchanging the buffer. Following operation was performed. 1) A globular DNA was attached to the tip of the micro needle electrode by gradient force. 2) The globule buffer was replaced with deionized water to transform the globular DNA to the random coil state DNA. As a result, the globular DNA has reverted to the random coil state DNA ,and the DNA was stretched and immobilized on a glass surface by sliding the glass on microscope stage or moving the needle electrode.

Presentation Number: 11aC-3

Title: Fluorescent Labeling of Individual DNA Polymerase and Visualization

Authors and Affiliation: Shun-ichi MATSUURA*, Yoshiyuki MIZUSHINA**, Hiroshi NAITO*, Jun KOMATSU*, Kengo SAKAGUCHI***, Shinji KATSURA* and Akira MIZUNO*　　*Department of Ecological Engineering, Toyohashi University of Technology, **Department of Nutritional Science, Kobe-Gakuin University, ***Department of Applied Biological Science, Science University of Tokyo

Abstract: Single DNA molecule observation permits the analysis of dynamics of protein such as polymerases although conventional assays elucidate averaged phenomena of proteins across a large number of DNA molecules. For example, single molecule observation based on a fluorescence microscopy provides a potential method for direct measurement of processivity and binding rate of protein. However, conventional methods of fluorescent labeling sometimes damage the enzymes seriously resulting in very low enzymatic activity, probably because of the binding of the dye to the functional site of the enzyme. We have developed the damage-free fluorescent labeling method for the microscopic observation. In our method, at first, DNA polymerase pre-bound on DNA molecule was chemically modified with amine-reactive fluorescent dye, Oregon Green 500. In next step, fluorescently labeled DNA polymerase was eluted from DNA with potassium chloride buffer. DNA-binding activity of the protein labeled in this way was not affected. We observed the fluorescent image of individual DNA polymerase b bound on straightened DNA molecule in the absence of dNTP and magnesium ion under a fluorescence microscope field. Our fluorescent labeling technique for DNA polymerase contributes to the observation of the dynamics of individual proteins on a single DNA molecule.

Presentation Number: 11aC-4

Title: Selective Detection of Bacteria by using Dielectrophoretic Impedance Measurement Method with Antigen-Antibody Reaction

Authors and Affiliation: Daisuke NOUTOMI, Junya SUEHIRO and Masanori HARA　　Graduate School of Information Science and Electrical Engineering, Kyushu University

Abstract: In our previous work, the authors proved how fast and easy was the Dielectrophoretic Impedance Measurement(DEPIM) method for detection technique of the biological cells supended in aqueous medium. So far, we've tested the DEPIM under the condition that only one strain of cells (E.coli) is suspended, whereas, in practical microorganism inspection, it is necessary to identify a particular strain of pathogenic bacteria from mixture of various bacteria. But the conventional DEPIM is not suitable for such a highly selective inspection because dielectric properties of bacteria are not so different between their species or strain that they are detected as an equivalent dielectric particle. In this paper, we propose two methods for selective bacteria detection using DEPIM combined with antigen-antibody reaction. In one method, antybody molecules are immobilized onto the microelectrode suraface, whereas, in the other method, agglutination of bacteria is employed to increase dielectrophoretic force. As a result, by using these metohds, we can leave target bacteria on the electrode surface. And furthermore, agglutinated bacteria can be electrically detected by DEPIM. It suggests that roposed methods can be more effective for selective detection in mixture of various bacteria.

Presentation Number: 11aC-5

Title: Development of amplification of unknown DNA fragment and

Single-Molecule PCR

Authors and Affiliation: Michihiko NAKANO, Jun KOMATSU, Shunichi MATSUURA, Keita SAITO, Hiroyoshi INAMI, Hachiro YASUDA, Kazunori TAKASHIMA, Shinji KATSURA, and Akira MIZUNO　　Department of Ecological Engineering, Toyohashi University of Technology

Abstract: We have been developing a new method for rapid DNA sequencing. This method consists of fixation of single DNA molecule with stretched shapes, cutting with restriction enzyme in order from terminus of DNA, recovery of cut DNA fragment, and sequencing. Advantage of this strategy, in principle, is that only a single DNA molecule is enough and the recovered DNA fragments keep information on their order. To achieve this method, single molecule of unknown DNA fragment should be amplified using PCR (Polymerase Chain Reaction). So amplification of unknown DNA fragment using PCR and new method for Single-Molecule PCR have been developed. To amplify unknown DNA, known DNA (denoted as linker DNA) should be ligated to both ends of target DNA, then amplify by PCR using primer complementary to linker DNA. This study demonstrated that 100 molecules of unknown DNA fragment could be successfully amplified without removing the enzyme or linker DNA. By using water-in-oil (W/O) emulsion, single molecule DNA was successfully amplified as follows: At the beginning of the amplification, the 1st 13 thermal-cycles were carried out in W/O emulsion. Because individual droplet in water functions as micro-reactor, effective concentration of template DNA raised drastically. After that, the emulsion was broken by centrifuge, in order to use the substrate that had not been used in the 1st 13 cycles. Then further 25 cycles were carried out and products were analyzed by electrophoresi

Presentation Number: 11aC-6

Title: Effect of PEF on peroxidase activity and its application

Authors and Affiliation: Takayuki Oshima, Isamu Imaizumi, Yukio Saito and Masayuki Sato　　Faculty of Engineering, Gunma University

Abstract: Effects of pulsed electric field (PEF) on native and denatured peroxidase activities were studied in this study. When PEF was applied to denatured peroxidase by heat treatment (92.5℃,5min),peroxidase refolding was enhanced at appropriate conditions. Relative activity after spontaneous refolding was about 30%, and 40% of relative activity was observed after 11.7 kV/cm and 30sec of PEF treatment. However, more than 15 kV/cm of PEF treatment resulted in decreased activity. These results suggested that peroxidase refolding is affected by PEF treatment and it could control the peroxidase activity. We also studied the effect of PEF on immobilized peroxidase bound to cellulose particles covalently. The sensitivity of immobilized peroxidase to heat or PEF treatment was different from that of soluble peroxidase. After 65℃ and 2min of heat treatment, relative activity of peroxidase was 20%. However, 50% of relative activity was observed after 20 kV/cm and 30sec of PEF treatment. It was proven that PEF can enhanced the refolding of peroxidase.

Presentation Number: １１aC-７

Title: DEP Chromatography with Cross-Flow Injection

Authors and Affiliation: Hikari SANO, Hiroyuki KABATA, Osamu KUROSAWA and Masao WASHIZU　　Department of Mechanical Engineering，Kyoto University

Abstract: DEP chromatography device with a cross-flow injector is developed. The device has two fluid passages crossing each other, one for the separation and the other for the sample injection. An array of micro electrodes for the dielectro-phoretic (DEP) separation is located in the separation channel downstream of the intersection. First, the sample is fed through the injection channel to fill the intersection, and then a carrier fluid is pumped through the separation channel. This process enables the pulse-wise injection of the sample into the carrier stream, and the amount of the injected sample is determined by the volume of the intersection. The solute in the sample is then subjected to the non-uniform field created by the electrode array, and the more polarizable the solute is, the higher the chance of the DEP entrapment becomes, and as a result, more delayed from the stream. Thus, a separation depending on the dielectric properties of the solute become possible. Using the device, the separation of 0.1 mm and 1mm latex particle, and the separation of 6.6 kbp and 48.5kbp DNA are experimentally demonstrated under the field strength of 1.2MV/m at 1MHz. Keywords: dielectrophoresis, chromatography, m-TAS, cross-flow injection, separation, DNA

Presentation Number: 11pA-1

Title: PTFE Thin Film Fabrication by Using UV Laser Ablation

Authors and Affiliation: Tetsuji ODA and Murat O. KARADENIZ　　School of Engineering, the University of Tokyo

Abstract: A PTFE (polytetrafluoroethylene) thin film is fabricated by using KrF excimer UV laser ablation technology and characteristics of that manufactured film are identified by surface topology (AFM) and by chemical bonding analysis (XPS). Main parameters are silicon substrate temperature and gas conditions (vacuum or with argon gas). The short distance between the target and the substrate is preferable. The substrate temperature should be more than 90℃. XPS is very effective in investigating the bonding conditions between carbon and fluorine. RF-sputtered PTFE thin film shows miscellaneous carbon signals.

Presentation Number: 11pA-2

Title: Precise Measurement of Size and Charge for Electrostatic Agglomeration

Authors and Affiliation: Yoji NAKAJIMA* and Takashi SATO**　　*Division of Mat.Sci.& Eng., Hokkaido Univ. **Hokkaido Institute of Technology

Abstract: As is well known, oscillation of a charged particle in an alternating electric field reflects its size and charge, and therefore we can measure them by monitoring the oscillation. Usually, the Stokes drag formula for steady motion of a sphere is assumed to be usable also for oscillating motion because very precise measurement is not always expected, and moreover, no formulas for the drag of an oscillating sphere have been confirmed experimentally. One of such formulas is a special case of the so-called Basset solution for oscillating flow, in which the convective terms in the Navier-Stokes equations are completely ignored. Since the ignorance of the convective terms may pose serious hydrodynamic problems, the drag formula for a sphere in oscillating flow has not been well acknowledged. This time we experimentally verify the formula to show that it provides more accurate measurement of size and charge.

Presentation Number: 11pA-3

Title: Preparation of LSGM Films for Fuel Cells by Pulsed Laser Deposition

Authors and Affiliation: Takeshi ITO*, Kenji YAMADA*, Seiji KANAZAWA*, Toshikazu OHKUBO*, Yukiharu NOMOTO*, Tatsumi ISHIHARA**, Yusaku TAKITA**　　* Department of Electrical and Electronic Engineering, Oita University,

** Department of Applied Chemistry, Oita University

Abstract: Doped LaGaO3 oxide has shown superior oxide ion conductivity. It is a promising candidate for an electrolyte in solid oxide fuel cells. The films, with the composition La1-xSrxGa1-yMgyO3-(x+y)/2 was prepared by KrF pulsed laser deposition. The dynamics of the plasma plume during the film deposition was investigated. The estimated velocity of the plume head is in the range of (0.5-1.5)×104m/s depending on the operational pressure. The films deposited on the NiO substrate consisted of many particles and crystalline structure of LaGaO3 was obtained for post annealed films.

Presentation Number: 11pA-4

Title: Preparation of silver coated PE particles and measurement of their dielectric constants aiming at high performance ER suspensions

Authors and Affiliation: ○Yoshitomo TERUI, Yoji NAKAJIMA and Kunio SHINOHARA　　Division of Mat. Sci. and Eng., Hokkaido University

Abstract: High dielectric constant, low density, and spherically shaped particles are recommended for electrorheological (ER) suspensions. We focus our attention on composite particles (e.g., plastic particles covered with metal). This time we intend to prepare such particles with a machine named the hybridizer, in which high speed rotating blades hit particles to fixate fine silver powder on polyethylene (PE) particle surface. The dielectric constant of the composite particles in silicone oil was measured on the basis of Rayleigh's equation. In our measurements, a pronounced non-linear relationship between the capacitance change and the volume fraction of particles in the suspension was found to make the calculated dielectric constant unreliable. We extrapolated the measured values to zero concentration to obtain reasonable values for the dielectric constant of the composite particles. The highest dielectric constant of the composite particles thus obtained so far was 30 with a density of 1.14 g/ml.

Presentation Number: 11pA-5

Title: Microparticle capture using EDB and single particle Raman spectroscopy

Authors and Affiliation: ○Yutaka AOKI, Azuchi HARANO, Takayuki TAKARADA　　Faculty of Engineering, Gunma University

Abstract: The apparatus, which was combined with EDB(Electrodynamic Balance) and Raman spectroscopy, was made for analysis of a single particle. The single microparticle was captured between two cylinder type electrodes on which DC voltages were applied. AC H.V. was applied on outer cylindrical electrode for the particle stabilization. Particles containing Ca[CaCO3, CaSO4] in diameter less than 100μm was used and Raman scattering from these particle was measured by argon ion laser. The excellent Raman spectra were obtained for identification of the chemical substance in calcium system

Presentation Number: 11pA-6

Title: Thermally Stimulated Current Spectra of Cryogenically Pulverized Polypropylene

Authors and Affiliation: Tatunori HASHIMOTO and Kazuo IKEZAKI　　Faculty of Science and Technology, Keio University

Abstract: Thermally stimulated current (TSC) spectra of polypropylene (PP) powders pulverized at low temperature were observed in the temperature range from room temperature to about 170 ℃. The obtained TSC spectra of powder-formed PP were remarkably different from those of films made of the same PP resin. The powder-formed PP shows a main TSC band peaked at 105-112 ℃ depending on its particle size, though the film samples show two TSC bands peaked at 60 and 120 ℃, respectively. Change in the higher order structure of PP induced by pulverization was found to be irreversible one, because annealing at about 150 ℃ of the pulverized PP did not bring about any changes in their TSC spectra. Observed results were discussed with the results of differential scanning calorimetry and wide angle X-ray diffraction

Presentation Number: 11pA-7

Title: Increase of Charge Decay on Low-density Polyethylene Film by Graft-copolymerization with Poly(Acrylic Acid)

Authors and Affiliation: ○Koichi MATSUMOTO and Yasuro HORI　　Department of Electrical and Computer Engineering, Nagoya Institute of Technology

Abstract: A surface of low density polyethylene (LDPE) film was modified by graft-copolymerization with poly(acrylic acid) in order to increase the surface charge decay without decreasing its high bulk electric resistance. The surface charge decay has been studied by measuring the two-dimensional distribution of charges, and its dependence on relative humidity was observed. The decay was very fast even at low humidity, and the spreading of charges along the surface was clearly observed. When the poly(acrylic acid) on the LDPE surface outside the certain square were removed, the surface charges have been observed not to migrate beyond that square and then the total charge did not decay even under 30% humidity. It was concluded that the charge migration along the surface was the major role in the charge decay on the LDPE film graft-copolymerized with poly(acrylic acid).

Presentation Number: 11pA-8

Title: Decay of charge on the surface of polymer films

Authors and Affiliation: Ryo Ono, Masaaki Nakazawa, Tetsuji Oda　　Department of Electrical Engineering, School of Engineering, the University of Tokyo

Abstract: Decay of charge on the surface of polymer films were measured by laser induced pressure method (LIPP). The film was charged by corona discharge in the atmosphere, then the charged surface of the film was shorten to the ground via a 50-Ohm resistor. The decay rate of the surface charge was almost equal among PTFE, FEP, and PP for several tens minutes after the short. After several hours, almost all of the charge had flowed into the ground. However, in PP, some charge remained inside the surface. The inner charge did not decrease with time at room temperature. It decreased as temperature increased.

Presentation Number: 11pA-9

Title: Increase of Surface Charge Decay on Polystyrene by Surface Modification with Sulfuric Acid

Authors and Affiliation: Katsuyoshi MORITA　　Department of Electrical and Computer Engineering, Nagoya Institute of Technology

Abstract: A surface of polystyrene (PS) film was modified with sulfuric acid. For this film, the increase of surface charge decay has been studied by measuring a series of two-dimensional distributions with time. The decay of charge density on the treated film was faster than that on untreated one, and the surface charges have decayed faster at higher humidity than at lower humidity. The spreading of charges along the surface was clearly observed. In order to make the charges not to migrate beyond the observed areas, the treated layer was squarely removed by the ditch dug on a treated PS film surface. On this sample, charges did not decay. Consequently it is concluded that the most part of charge decay on PS film treated with sulfuric acid occurred through the migration along the surface.

Presentation Number: 11pC-1

Title: Fundamental Characteristics of EHD Pump with Unit Electrode System

Authors and Affiliation: Kyoko Yatsuzuka, Shunsuke Tachibana and Kazutoshi Asano　　Faculty of Engineering, Yamagata University

Abstract: Electrohydrodynamic (EHD) pump could be a low cost and low power consuming pump, because its structure is simple without moving parts. We have investigated the fundamental characteristics of an ion drag type EHD pump with needle electrodes. In our previous reports, it is clarified that the EHD effect will be enhanced by taking advantage of fluid resistance. In this report module type electrode systems are utilized. The level of the silicone oil gradually rises up to over 400 mm when the DC high voltage is applied, and falls down quickly when the applied voltage is removed. The average value of rising velocity of the liquid level agrees with the evaluation from its mass velocity. When the modules of the electrode system are in series, only little advance is observed, or worse.

Presentation Number: 11pC-10

Title: Measurement of surface electric charge density of fibers of electret air filter

Authors and Affiliation: ○Shinpei Tsukamoto and Yuji Murata　　Science University of Tokyo,Faculty of Science & Technology

Abstract: Charging states of fibers of electret air filters was investigated using ultrafine toner particles for attaching to fibers. The obtained result showed that the fibers have an average of 1×10-5 C/m2 surface electric charge density. By using this method , it is thought that surface electric charge density of fibers can be used as one of the indices of performance of electret air filter.

Presentation Number: 11pC-2

Title: Separation of Water-in-Oil Emulsions by EHD Forces

Authors and Affiliation: Noriyasu YAMAMOTO, Shuichi AKAMINE, Seiji KANAZAWA, Toshikazu OHKUBO, Yukiharu NOMOTO　　Department of Electrical and Electronic Engineering, Oita University

Abstract: Electrohydrodynamics (EHD) is widely used to control the fluid motion. In the liquid, the EHD forces include electrophoresis force, ion drag force, dielectrophoresis force, etc. In this study, the separation of the water-in-oil emulsions by a dc electric field was carried out experimentally. The effect of the applied voltage, water concentration, and the electrode geometry on the separation of the emulsions was investigated. The separation rate was measured as a function of operational time. It was found that the separation was enhanced under a non-uniform field such as a needle-to-rods electrode system.

Presentation Number: 11pC-3

Title: Fundamental Characteristics of Induction Type Generators for Demonstration of Electrostatic Phenomena

Authors and Affiliation: Kyoko Yatsuzuka, Kyoichi Tamura and Kazutoshi Asano　　Faculty of Engineering, Yamagata University

Abstract: Electrostatic generators convert mechanical energy to electrical energy directly. They are simple and produce high voltage quickly, while the energy converted remains small. This report concerns about the induction-type electrostatic generator. Although this type generator were there very long time ago, the progress was slow until A. D. Moor made "dirod", one of the induction-type electrostatic generators, and used them for demonstration on the Electrostatics. We made handy sized dirods and examined them to see how high the voltage generated is. There are several parameters we have to pay particular attention. Any tiny discharge spoils its feature. The stability of voltage generated depends on the discharge, the polarity of voltage sometimes flips over. Several kinds of substances for the brushes, which are used to collect the conveyed charge from the moving rods, were examined. The conductive rubber shows reasonable results, because of its conductivity and elasticity

Presentation Number: 11pC-4

Title: Basic Research on Disk Type Corona Motors (�Y)

Authors and Affiliation: Masayuki HATTORI*, Kouichi INOMATA*,Toshiyuki AOKI*,Yamato SEKI* and Kenkichi IZUMI**　　*Sendai National College of Technology, **Shishido Electrostatic, Ltd.

Abstract: In our previous reports, disk type corona motors using two different shapes of discharging electrodes as the stator have been made and tested. One is a thin copper foil type electrode, the other is a printed circuit board (pcb) type one, and it has been cleared that the latter is superior in various characteristics. Each disk of the rotor and the stator (discharging electrodes) has a structure which can utilize both sides of the disk for the purpose of extension to a multi-disk type corona motor. This time, we have made a CD (Compact Disk) type of rotor consisting of two CDs and have compared the torque characteristics with the former type of rotor (pcb rotor). It has been clarified that the CD type of rotor has the same torque but the smaller current compared with the pcb rotor, then can increase the efficiency. As an application of this motor, a new type of ozonic generation and circulation pump is proposed.

Presentation Number: 11pC-5

Title: Characteristics of Precipitation Efficiency and Gas Velocity for Electrostatic Precipitator of Special Structure

Authors and Affiliation: Ayumu IIJIMA　　Fukui University of Technology

Abstract: A new electrostatic precipitator structure is proposed and a preliminary precipitation efficiency study is presented. Conventional precipitators exhibit lower precipitation efficiency when gas flow is accordance with gas flow is increased in accordance with the Deutsch formula. The structure of the proposed precipitator is such that ion winds caused by corona discharges and gas currents collide against collecting electrodes. When the gas flow is increased in the proposed precipitator to process a greater volume of gas, the decrease in precipitation efficiency is small and the difference between the conventional and proposed techniques increases. Application of the proposed structure is expected to lead to a reduction in the size of precipitators.

Presentation Number: １１ｐＣ−６

Title: Electrostatic Separation of Metallic Particles

Authors and Affiliation: Haruhisa FUJII*, Toshihiro IKAI** and Yasuto ISEKI***　　Advanced Technology R&D Center*, Industrial & Environmental Engineering Center** and Headquarter***, Mitsubishi Electric Corporation

Abstract: It is necessary to make the behavior of metallic particles clear in order to remove them in mixed plastics in the development of high-efficiency electrostatic separators for material-recycle use. In this paper, we described the analytical results of their behaviors in the electric field of a roll-type electrostatic separator.

Presentation Number: 11pC-7

Title: Motion and Estimated Charge of a Spherical Particle under Non-uniform Electric Field in Dielectric Liquid

Authors and Affiliation: Changrag CHOI＊, Kyoko YATSUZUKA＊＊ and Kazutoshi ASANO＊＊　　＊Faculty of Science & Technology, Science University of Toyko

＊＊Faculty of Engineering, Yamagata University

Abstract: In order to seek a suitable electrode configuration removing impurities contained in liquefied plasitcs waste, a tilted plane electrode system is constructed and the particle motion was investigated under non-uniform electric field. The particle charged by induction moves either direction of the electrodes showing up-and-down motion. When the applied voltage is relatively low, the particle moves toward the narrow gap side and as the applied voltage is high enough, it moves toward the wider gap side. The particle was trapped at the middle of the electrodes and repeats stationary up-and-down motion at the particular voltage. The trapped position of the particle moves toward the wider gap side with the applied voltage. The electric field at the trapped position is almost constant, 1.8 MV/m. The comparision with the experimental trapped position and the calculated one is performed. From the simulation for the trapped position, when the charge amount which the particle acquired is a half of that predicted by induction, the calculated trapped position is well accordance with the experimental one.

Presentation Number: 11pC-8

Title: Development of Dielectrophoretic Filter for Elimination and Collection of Fine Particles Suspended in Liquid

Authors and Affiliation: Guangbin ZHOU, Manabu IMAMURA, Junya SUEHIRO and Masanori HARA　　Graduate School of Information Science and Electrical Engineering, Kyushu University

Abstract: Dielectrophoresis is the electrokinetic motion of dielectrically polarized particles in non-uniform electric fields. Dielectrophoresis has found many useful biotechnological applications including separation, levitation and characterization of dielectric particles and biological cells. In this study, the authors propose a new type of filter, which utilizes dielectrophoretic force to capture fine particles suspended in liquid. The filter consists of an electrode system that is filled up with many dielectric particles. The filled particles modify electric field distribution in the electrode system so that strong dielectrophoretic force is generated on their surfaces. If the dielectrophoretic force is stronger than drag force exerted by liquid flow in the filter, suspended particles can be trapped and eliminated from liquid flow. It was experimentally confirmed that proposed filter basically worked as designed. The filter can control trapping and releasing process just by changing application voltage and resultant dielectrophoretic force. 95% of yeast cells were continuously eliminated from suspension liquid.

Presentation Number: 11pC-9

Title: An Experimental Development of Environmentally Friendly Electret Filter

Authors and Affiliation: Masaharu NIFUKU*, Susumu SATOH**, Tadahiro KOBAYSHI, Yuan-Xiang ZHOU*** and Hiromi KATOH　　*Research Institute for Green Technology, National Institute of Advanced Industrial Science and Technology, **Niigata Plant, Toyo Roshi Kaisha Ltd., ***Department of Electrical Engineering, Tsinghua Universit

Abstract: Paying attention to the environmental impact, the authors tried to develop environmentally friendly electret filters. Polypropylene (PP) filter (non-woven, by melt blowing) and polytetrafluoroethylene (PTFE) filter were made as the samples. After investigating the charging characteristics of electrical charging methods, electret filters were manufactured in the laboratory experimentally. High voltage DC corona, pulse corona and pulse with DC