WorldWideScience

Sample records for cataphoresis

  1. A study of radial cataphoresis and ion densities in high power density Hg-Ar discharges

    Energy Technology Data Exchange (ETDEWEB)

    Aiura, Y; Lawler, J E [Department of Physics, University of Wisconsin, 1150 University Avenue, Madison, WI 53706 (United States)

    2004-11-21

    A synchrotron radiation absorption experiment was used to measure the absolute density of ground level Hg atoms and Hg{sup +} ions in Hg-Ar discharge plasmas at high power densities. Ion densities from this experiment were tested using microwave interferometry and compared with Langmuir probe measurements of the electron density. Radial cataphoresis was observed in this experiment and compared with model predictions. The agreement was satisfactory between the experiment and model. The role of cataphoresis in the power balance of Hg-Ar plasmas was further explored in the research described in the companion paper (Lister et al. 2004 J. Phys. D: Appl. Phys. 37: 3099-3106)

  2. Characteristics of a Cataphoresis He-Ca+ Recombination Laser

    Institute of Scientific and Technical Information of China (English)

    CHEN Li; PAN Bai-Liang; WANG Ya-Juan; MAO Bang-Ning

    2009-01-01

    A cataphoretic input of calcium vapour into the active volume of pulsed He-Ca+ laser is designed and made. The recombination laser at 373.3nm and the R-M transition laser at 854.6nm are achieved experimentally with modified Blumlein circuit by high-frequency longitudinal pulsed discharge. The dependences of work parameters such as the pulse frequency, the power supply voltage and the helium pressure on laser output characteristics at 373.3 nm line are measured and discussed. The maximum laser output power of 136mW and the specific power of 5.9 m W/cm3 are obtained, respectively.

  3. Application of Silane and Nanoceramic Composite Technology in Automotive Cataphoresis Coating%硅烷-纳米陶瓷复合技术在汽车电泳涂装的应用研究

    Institute of Scientific and Technical Information of China (English)

    赵凯利; 王成; 孙振华

    2015-01-01

    在汽车涂装领域,无磷前处理技术由于其节能环保的突出优势,替代传统磷化工艺的趋势日益明显.简要介绍了硅烷-纳米陶瓷复合技术的作用机理及其性能特点,同时,就此项技术在车身、车架以及板簧电泳涂装应用过程中出现的一些问题进行了探讨.

  4. Koedam {beta} factors revisited

    Energy Technology Data Exchange (ETDEWEB)

    Lawler, J.E. [Physics Department, University of Wisconsin, Madison, WI (United States); Doughty, D.A. [Perkin-Elmer Optoelectronics, Santa Clara, CA (United States); Lister, G.G. [OSRAM SYLVANIA Inc., Beverly, MA (United States)

    2002-07-21

    A Koedam {beta} factor makes it possible to compute the total output power in line radiation from a positive column discharge using a single radiance measurement normal to an aperture in the wall. The results of analytic derivations of {beta} factors are presented for columns with uniform ({beta}=1.0) and parabolic ({beta}=0.75) excitation rates per unit volume and with negligible opacity. A Monte Carlo code for simulating radiation trapping with a spatially uniform density of absorbing atoms is then used to determine {beta} factors as a function of opacity. The code includes partial frequency redistribution and a Voigt line shape with radiative broadening, resonance collisional broadening, and Doppler broadening. The resulting {beta} factors are found to be nearly independent of opacity over a wide range of column radii for spectral line shapes dominated by Doppler broadening or by resonance collisional broadening. Additional Monte Carlo simulations are used to study {beta} factors as a function of a non-uniform density of absorbing atoms from radial cataphoresis with line shapes dominated by Doppler broadening, foreign gas broadening, and resonance collisional broadening. Radial cataphoresis is found to increase {beta} factors in all cases. Geometrical effects, refraction, and imperfect transmission at the glass wall are studied and found to decrease {beta} factors. (author)

  5. Koedam β factors revisited

    International Nuclear Information System (INIS)

    A Koedam β factor makes it possible to compute the total output power in line radiation from a positive column discharge using a single radiance measurement normal to an aperture in the wall. The results of analytic derivations of β factors are presented for columns with uniform (β=1.0) and parabolic (β=0.75) excitation rates per unit volume and with negligible opacity. A Monte Carlo code for simulating radiation trapping with a spatially uniform density of absorbing atoms is then used to determine β factors as a function of opacity. The code includes partial frequency redistribution and a Voigt line shape with radiative broadening, resonance collisional broadening, and Doppler broadening. The resulting β factors are found to be nearly independent of opacity over a wide range of column radii for spectral line shapes dominated by Doppler broadening or by resonance collisional broadening. Additional Monte Carlo simulations are used to study β factors as a function of a non-uniform density of absorbing atoms from radial cataphoresis with line shapes dominated by Doppler broadening, foreign gas broadening, and resonance collisional broadening. Radial cataphoresis is found to increase β factors in all cases. Geometrical effects, refraction, and imperfect transmission at the glass wall are studied and found to decrease β factors. (author)

  6. Power balance in highly loaded fluorescent lamps

    Energy Technology Data Exchange (ETDEWEB)

    Lister, G G [Osram Sylvania, 71 Cherry Hill Drive, Beverly, MA 01915 (United States); Curry, J J [National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, MD 20899-8422 (United States); Lawler, J E [Department of Physics, University of Wisconsin, 1150 University Avenue, Madison, WI 53706 (United States)

    2004-11-21

    Discrepancies reported in the literature between numerical predictions and experimental measurements in low-pressure Hg discharges at high current densities are considered. Elements of a one-dimensional fluid model and recent spectroscopic and Langmuir probe measurements are combined in a semi-empirical way to individually examine components of the positive column power balance and the discharge conductivity. At a Hg vapour pressure of 0.81 Pa (6.1 mTorr) and a current density of 300 mA cm{sup -2}, previous discrepancies in the power balance and discharge conductivity are simultaneously resolved by assuming a higher electron density than that obtained from the Langmuir probe measurements. This conclusion is supported by independent measurements of ion density reported in a companion paper. The importance of radial cataphoresis under these conditions, particularly with regard to radiation transport, is highlighted. This work is of particular interest for the design of fluorescent lamps operating at high current densities.

  7. Application of advanced oxidation processes (AOPs) for the treatment of a particular industrial wastewater

    International Nuclear Information System (INIS)

    The present paper refers about the use of some advanced oxidation processes for the treatment of a particular industrial wastewater polluted by organic acids and solvents. Such waste is generated during the electrodeposition of paint in cathodic technological systems (cataphoresis). The AOPs studied were the following: H2O2-UV, O3 in strongly alkaline media and Fe(met)-H2O2. The latter which represents a derivation of the Fenton process gave the best results in terms of reaction times, costs in management and reduction rate of organic matter. Its efficiency was also confirmed by some laboratory tests made on synthetic samples. The reactors used to perform the experiments with ozone and H2O2-UV were especially created. The degradation of the organic compounds was quantified by monitoring the COD parameter and in some cases by detecting the concentration of each individual pollutant

  8. Tomographic diagnostics of high-frequency electrodeless lamps in argon-mercury mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Denisova, N [Institute of Theoretical and Applied Mechanics, Novosibirsk, Russia (Russian Federation); Revalde, G [Institute of Atomic Physics and Spectroscopy, University of Latvia, Raina blvd. 19, Riga (Latvia); Skudra, A [Institute of Atomic Physics and Spectroscopy, University of Latvia, Raina blvd. 19, Riga (Latvia); Bogans, E [Institute of Atomic Physics and Spectroscopy, University of Latvia, Raina blvd. 19, Riga (Latvia)

    2006-03-21

    Tomographic reconstruction of spatial profiles of the mercury atom density in the excited state 7 {sup 3}S{sub 1} in high-frequency electrodeless lamps (HFELs) has been performed. The measurements of the Hg 546.1 nm line emission intensity have been made for the HFELs in argon-mercury mixture depending on the operation regime with different cold spot temperatures in the range 31-98 deg. C. The maximum entropy-based algorithm was applied for the reconstruction of local emission coefficients from the integrated intensities. The emission coefficients are directly related to the local values of the mercury atom density in the excited state 7 {sup 3}S{sub 1}, the upper state of the 546.1 nm transition. Such an investigation has been performed first for the HFEL. We have found that the emitting mercury atoms in the state 7 {sup 3}S{sub 1} are concentrated in a thin layer located close to the lamp wall. The radial profiles have demonstrated a strong depletion of the population density in the state 7 {sup 3}S{sub 1} from the lamp centre at high generator currents and low mercury vapour density. The obtained results are analysed theoretically in the context of the radial cataphoresis phenomenon. We found a qualitative agreement between the reconstructed density profiles and theoretical model predictions.

  9. Propagator description of radiation transport, applied to lighting discharges

    Energy Technology Data Exchange (ETDEWEB)

    Wichaidit, C; Hitchon, W N G [Department of Electrical and Computer Engineering, University of Wisconsin, 1415 Engineering Drive, Madison, WI 53706 (United States); Lawler, J E [Department of Physics, University of Wisconsin, 1150 University Avenue, Madison, WI 53706 (United States); Lister, G G, E-mail: wichaidi@gmail.co [OSRAM SYLVANIA Inc., 71 Cherry Hill Dr., Beverly, MA 01915 (United States)

    2009-01-21

    Radiation transport calculations based on the use of propagators (or Green's functions) are presented for the Hg resonance at 254 nm in the complete frequency redistribution regime. This resonance radiation plays a dominant role in the power balance of fluorescent lamps. Recent studies have suggested that transport modes above the fundamental are important in some lamp discharges. The Holstein transmittance function T(R) used to evaluate the probabilities is generated by numerical integration across the line profile at low and medium opacity. Complete hyperfine and isotopic patterns with a Voigt profile for each component are used in the model. A simple analytic expression for T(R) from a pure Lorentzian profile is used at high opacity. The calculation includes radial cataphoresis (a radial-dependent ground state Hg density). Evaluation of propagator matrix elements-probabilities of photons travelling from one cell to another-is done by integrating T(R) with the source points distributed radially across the source cell in cylindrical geometry. A radiation transport matrix or propagator function obtained from direct integration is compared with very detailed Monte Carlo simulations of radiation transport in cylindrical geometry. The probability matrix is then used in a self-consistent fluorescent lamp discharge model. Details of the numerical model are discussed. The trapped decay rates at different discharge currents and temperatures obtained by fluorescent lamp discharge simulations are compared with those calculated from an analytic formula.

  10. The physical nature of the phenomenon of positive column plasma constriction in low-pressure noble gas direct current discharges

    International Nuclear Information System (INIS)

    The essence of the positive-column plasma constriction for static (the diffusion mode) and dynamic ionization equilibrium (the stratificated and constricted modes) is analyzed. Two physical parameters, namely, the effective ionization rate of gas atoms and the ambipolar diffusion coefficient of electrons and ions, determine the transverse distribution of discharge species and affect the current states of plasma. Transverse constriction of the positive column takes place as the gas ionization level (discharge current) and pressure increase. The stratified mode (including the constricted one) is observed between the two adjacent types of self-sustained discharge phases when they coexist together at the same time or in the same place as a coherent binary mixture. In the case, a occurrence of the discharge phase with more high electron density presently involve a great decrease in the cross-section of the current channel for d.c. discharges. Additional physical factors, such as cataphoresis and electrophoresis phenomena and spatial gas density inhomogeneity correlated with a circulatory flow in d.c. discharges, are mainly responsible for the current hysteresis and partially constricted discharge

  11. ELECTROKINETIC PHENOMENA. II : THE FACTOR OF PROPORTIONALITY FOR CATAPHORETIC AND ELECTROENDOSMOTIC MOBILITIES.

    Science.gov (United States)

    Abramson, H A

    1930-07-20

    Two theories which predict different values for the ratio of V(E), the electroendosmotic velocity of a liquid past a surface, to V(p), the electric mobility of a particle of the same surface through the same liquid are discussed. The theory demanding that See PDF for Equation was supported by certain data of van der Grinten for a glass surface. Re-calculation of van der Grinten's data reveals that the ratio varies between 2.1 and 2.8. These results are in accord with previous data of Abramson. It is pointed out that glass is unsuitable for the investigation. The ratio See PDF for Equation is here determined for a flat surface and particles when both are covered by the same proteins. Under these conditions See PDF for Equation The theory is similarly tested for a round surface using a micro-cataphoresis cell. It is shown that See PDF for Equation for a round surface is approximately 1.00. These findings are confirmatory of previous data supporting the view that cataphoretic mobility is independent of the size and shape of the particles when all particles compared have similar surface constitutions. PMID:19872555

  12. My academic life with isotopes

    International Nuclear Information System (INIS)

    The present article outlines investigations and experience made by the author in carrying out a variety of studies on isotopes since 1939. First, he was interested in transuranic elements and his studies on artificial radioactive isotopes covered the detection of plutonium at Nagasaki, chemical separation of plutomium from atmosphere at Tokyo, spectral analysis of alpha rays from plutomium, application of 113mIn to emission spectral analysis as a tracer, chemical enrichment of 76As hot atom, and non-destructive analysis of the chemical state of 119Sn produced through EC disintegration in solid material. His studies on natural radioactivity include measurement of the radium content in rock and mineral samples collected in the Korean Peninsula, investigation on the formation process of minerals found around hot springs and determination of the age of rock and mineral samples. He started investigations on isotope enrichment around 1965. Studies in this field cover the application of cataphoretic processes to separation of 23Na and 22Na, enrichment of 7Li and other alkali metals, enrichment of 6Li by isotope exchange, derivation of an empirical equation (Saito-Kanno Equation) for mass effect in couter-current cataphoresis of molten halides, etc. (Nogami, K.)