WorldWideScience

Sample records for surface discharge lamps

  1. Discharge lamp technologies

    Energy Technology Data Exchange (ETDEWEB)

    Dakin, J. [GE Lighting, Cleveland, OH (United States)

    1994-12-31

    This talk is an overview of discharge lamp technology commonly employed in general lighting, with emphasis on issues pertinent to lighting for plant growth. Since the audience is primarily from the plant growth community, and this begins the light source part of the program, we will start with a brief description of the discharge lamps. Challenges of economics and of thermal management make lamp efficiency a prime concern in controlled environment agriculture, so we will emphasize science considerations relating to discharge lamp efficiency. We will then look at the spectra and ratings of some representative lighting products, and conclude with a discussion of technological advance. A general overview of discharge lighting technology can be found in the book of Waymouth (1971). A recent review of low pressure lighting discharge science is found in Dakin (1991). The pioneering paper of Reiling (1964) provides a good introduction to metal halide discharges. Particularly relevant to lighting for plant growth, a recent and thorough treatment of high pressure Na lamps is found in the book by deGroot and vanVliet (1986). Broad practical aspects of lighting application are thoroughly covered in the IES Lighting Handbook edited by Kaufman (1984).

  2. Case Study on Justification: High Intensity Discharge Lamps. Annex II

    International Nuclear Information System (INIS)

    2016-01-01

    High intensity discharge lamps produce bright white light of a high intensity in an energy efficient manner. These lamps are typically used in large numbers in public and professional settings such as shops, warehouses, hotels and offices. They are also used in outdoor applications to illuminate streets, buildings, statues, flags and gardens and further as architectural lighting. They also have applications associated with film projection in cinemas, manufacture of semiconductors, fluorescence endoscopy and microscopy, schlieren photography, hologram projection, ultraviolet curing, sky beamers and car headlights. Some types of high intensity discharge lamp, as well as certain other consumer products for lighting, contain radioactive substances for functional reasons. The radionuclides that are typically incorporated into high intensity discharge lamps are 85 Kr and 232 Th. Given the wide range of uses, specific decisions on justification may be required for different applications. A small number of safety assessments for high intensity discharge lamps have been carried out and published. No published decisions at the national level specifically addressing the justification of the use of high intensity discharge lamps have been identified

  3. Max Tech and Beyond: High-Intensity Discharge Lamps

    Energy Technology Data Exchange (ETDEWEB)

    Scholand, Michael

    2012-04-01

    High-intensity discharge (HID) lamps are most often found in industrial and commercial applications, and are the light source of choice in street and area lighting, and sports stadium illumination. HID lamps are produced in three types - mercury vapor (MV), high pressure sodium (HPS) and metal halide (MH). Of these, MV and MH are considered white-light sources (although the MV exhibits poor color rendering) and HPS produces a yellow-orange color light. A fourth lamp, low-pressure sodium (LPS), is not a HID lamp by definition, but it is used in similar applications and thus is often grouped with HID lamps. With the notable exception of MV which is comparatively inefficient and in decline in the US from both a sales and installed stock point of view; HPS, LPS and MH all have efficacies over 100 lumens per watt. The figure below presents the efficacy trends over time for commercially available HID lamps and LPS, starting with MV and LPS in 1930's followed by the development of HPS and MH in the 1960's. In HID lamps, light is generated by creating an electric arc between two electrodes in an arc tube. The particles in the arc are partially ionized, making them electrically conductive, and a light-emitting 'plasma' is created. This arc occurs within the arc tube, which for most HID lamps is enclosed within an evacuated outer bulb that thermally isolates and protects the hot arc tube from the surroundings. Unlike a fluorescent lamp that produces visible light through down-converting UV light with phosphors, the arc itself is the light source in an HID lamp, emitting visible radiation that is characteristic of the elements present in the plasma. Thus, the mixture of elements included in the arc tube is one critical factor determining the quality of the light emitted from the lamp, including its correlated color temperature (CCT) and color rendering index (CRI). Similar to fluorescent lamps, HID lamps require a ballast to start and maintain stable

  4. A study on double hollow electrode discharge and the enhanced performance for electric discharge lamps

    International Nuclear Information System (INIS)

    Lee, Tae Il; Park, Ki Wan; Hwang, Hyeon Seok; Choi, Jai Hyuk; Baik, Hong Koo

    2006-01-01

    We invented a double hollow electrode lamp (DHEL), applied an electron oscillation effect and measured its I-V curve in dc driving to evaluate the electrical characteristics. The volume discharge of this lamp showed an abnormal glow characteristic. Based on these results, we made a 9-channel flat panel lamp and confirmed the possibility of a parallel operation. In order to evaluate the enhanced performance of the DHEL, we compared it with a single hollow triode lamp and a diode lamp (DL). We measured the breakdown voltage, tube current and IR intensity of these three types of lamps. The DHEL showed the lowest breakdown voltage among the three lamps and a higher tube current than that of the DL. The IR intensity of the DHEL was more efficient than that of the DL; the enhanced quantity of efficiency was 11.8% at 0.922 W

  5. Physical aspects of mercury-free high pressure discharge lamps

    International Nuclear Information System (INIS)

    Born, M.

    2002-01-01

    This paper gives a summary of recent results about the replacement of mercury in high pressure discharge lamps by metallic zinc. Actually, this topic is of high relevance for the lighting industry due to the need of more environmentally friendly products. The work presented here is supported by the German government under contract no. 13N8072. Pure zinc/argon discharges as well as lamps including zinc or mercury and metal halide additives are investigated. Experimental data are compared with model calculations of the energy balance involving the transport of heat and radiation. Since the excitation energies of relevant zinc transistions are lower than for mercury, axis temperatures of pure zinc lamps are about 300 K below the value of mercury arcs. In addition, the thermal conductivity of zinc including the contribution of radiation diffusion is larger than compared to mercury. From lamp voltage measurements it is found that the cross section for elastical electron scattering by zinc atoms is about the same as for mercury. When adding metal halides to a pure zinc discharge with argon as a starting gas, i.e. NaI, TlI, DyI3, axis temperatures decrease to about 5100 K due to strong radiation cooling. In order to obtain sufficiently large lamp voltages, wall temperatures of more than 1300 K are adjusted by means of polycrystalline aluminaoxide (Al2O3) as a wall material. Electrical field strenghts of 6.0 V/mm and 8.6 V/mm are measured for metal halide lamps containing zinc or mercury, respectively. The light technical data of the discharges are very close, since mercury and zinc do not contribute significantly to the radiation in the visible range. Efficacies of up to 93 lm/W and 100 lm/W are found in metal halide lamps with zinc and mercury, respectively. Consequently, zinc turns out to be an attractive replacer for mercury in this type of lamp not only from an environmental point of view

  6. Spectral and photopic studies for high intensity discharge (HID lamps

    Directory of Open Access Journals (Sweden)

    Abd-Elmageed A.-E.A.

    2015-01-01

    Full Text Available Outdoor lighting sources such as High Intensity Discharge lamps (HID are common in these days. This research is focusing on the relation between the spectral power distribution and luminous efficiency function V(λ, which describes the average spectral sensitivity of human visual perception of brightness. The most useable HID lamps inside Egyptian markets are high pressure mercury (HPM, high pressure sodium (HPS and metal halide (MH. A set up based on single monochromator and integrating sphere for relative spectral power distribution and absolute luminous flux measurements are used, respectively. The accompanied standard uncertainties with the measurements are evaluated.

  7. Status quo of ceramic material for metal halide discharge lamps

    International Nuclear Information System (INIS)

    Kappen, Theo G M M

    2005-01-01

    Polycrystalline alumina is an excellent ceramic material for use as the envelope for metal halide discharge lamps. Although this material was introduced in the mid-1960s, and is thus already known for several decades, recent years have seen considerable effort aimed at further development of these ceramic envelope materials. Developments are not only in the field of ceramic shaping technologies, but are also concentrated on the material properties of the ceramic material itself. Optical, mechanical as well as the chemical properties of the ceramic envelope are strongly controlled by the shape as well as the microstructure of the ceramics used

  8. Ultraviolet gas-discharge lamp on iodine molecules

    Science.gov (United States)

    Shuaibov, A. K.; Minya, A. I.; Gomoki, Z. T.; Kalyuzhnaya, A. G.; Shchedrin, A. I.

    2010-08-01

    The emission characteristics of a pulsed-periodic UV radiation source are reported. The source excited by a pulsed-periodic capacitive discharge initiated in helium-iodine vapor, neon-iodine vapor, or krypton-iodine vapor mixtures radiates in the spectral range 200-450 nm. It is shown that most of the plasma radiation power concentrates in the integral line of the iodine atom (206.2 nm) and in the D'- A' band of the iodine molecule with a maximum at 342 nm. The radiation intensity of the lamp is optimized in accordance with the partial pressure of the inert gases. The discharge plasma parameters that are of interest for simulating the process kinetics and the output characteristics of an UV source based on molecular iodine, atomic iodine, and xenon iodide are calculated in helium-iodine vapor and xenon-iodine vapor mixtures.

  9. A Comparison of AC and Short-Pulse Excitation for Xe Excimer Barrier Discharge Lamps

    Science.gov (United States)

    Mildren, R. P.; Morrow, R.; Carman, R. J.

    1999-10-01

    Dielectric barrier discharge excitation of rare-gas and rare-gas halide excimers provides an efficient scheme for generating intense VUV radiation for applications including lighting, ozonisation, and photochemical surface treatment. Typically, lamps employ AC (sinusoidal) voltage excitation in which case VUV emission is produced from short-livid micro discharges (streamers) distributed stochastically over the dielectric. However, it has been recently demonstrated that significantly increased efficiency (by factor 2-3) can be obtained from Xe lamps when using short excitation pulses separated by idle periods[1]. In this paper, we report an investigation into the mechanisms which bring about improved efficiency by comparing the electrical, spectral and spatial emission characteristics of a small-scale Xe lamp excited by short pulses ( 100ns) with that of conventional AC excitation. The results reveal that pulsed excitation produces a homogenous glow-like discharge in which the electron density and temperature are more favourable for efficient excimer production. [1] RP Mildren et al, IVth Int. Conf. Atom. and Molec. Pulsed Lasers, Tomsk, Siberia Sept. (1999); F Vollkommer and L Hitzschke, Proc. 8th Int. Symp. Sci. Tech. Light Sources, Greifswald, Germany, '98, IL-07, pp51-59 (1998)

  10. 21 CFR 1040.30 - High-intensity mercury vapor discharge lamps.

    Science.gov (United States)

    2010-04-01

    ... advertisement. Advertising for any high-intensity mercury vapor discharge lamp that does not comply with... mercury and that is contained within an outer envelope. (2) Advertisement means any catalog, specification... 21 Food and Drugs 8 2010-04-01 2010-04-01 false High-intensity mercury vapor discharge lamps. 1040...

  11. Emitter depletion studies on electrodes of 50 Hz mercury/noble gas discharge lamps during ignition

    Energy Technology Data Exchange (ETDEWEB)

    Hoek, W.J. van den [Philips Lighting B V Central Development Lamps, Eindhoven (Netherlands)]. E-mail: wj.van.den.hoek@philips.com; Thijssen, T.L.G.; Heijden, A.J.H. van der; Buijsse, B.; Haverlag, M. [Philips Lighting B V Central Development Lamps, Eindhoven (Netherlands)

    2002-07-21

    The depletion of emitter from the oxide cathodes during the glow switch starting of the discharge in 50 Hz operated low-pressure mercury/noble gas discharge lamps (fluorescent lamps) has been studied. It follows from pulse ignition studies and computer-controlled ignition experiments that two plasma modes exist during ignition: a glow discharge and a vapour-arc discharge. The occurrence of these modes depends on the point of interruption with respect to the phase of the 50 Hz preheat current. The vapour arc appears to be the dominant mechanism of emitter depletion. The average emitter loss per vapour-arc pulse has been quantified by radioactive Ba tracer experiments. The nature of the vapour arc has been studied by fast photography and SEM. The vapour arc involves dielectric breakdown over the non-conducting oxide mass and gives rise to explosive emitter vapourization. (author)

  12. The Electrodeless Discharge Lamp: A Prospective Tool for Photochemistry Part 3. The Microwave Photochemistry Reactor

    Czech Academy of Sciences Publication Activity Database

    Klán, P.; Hájek, Milan; Církva, Vladimír

    2001-01-01

    Roč. 140, č. 3 (2001), s. 185-189 ISSN 1010-6030 Institutional research plan: CEZ:AV0Z4072921 Keywords : photochemistry * electrodeless discharge lamp * microwave Subject RIV: CH - Nuclear ; Quantum Chemistry Impact factor: 1.038, year: 2001

  13. Photodebromination of Opaque Slurries Using Titania-Coated Mercury Electrodeless Discharge Lamps.

    Czech Academy of Sciences Publication Activity Database

    Kaštánek, František; Církva, Vladimír; Kmentová, Hana; Kaštánek, P.; Šolcová, Olga

    2016-01-01

    Roč. 3, č. 7 (2016), s. 5262-5267 ISSN 2458-9403 R&D Projects: GA TA ČR TA04020700 Institutional support: RVO:67985858 Keywords : photocatalysis * electrodeless discharge lamp * polybrominated diphenyl ethers Subject RIV: CI - Industrial Chemistry, Chemical Engineering

  14. Investigation on the effect of impurities in xenon based dielectric barrier discharge lamps

    Energy Technology Data Exchange (ETDEWEB)

    Dagang, A N; Bhosle, S; Zissis, G [Universite de Toulouse, UPS, INPT, LAPLACE (Laboratoire Plasma et Conversion d' Energie), 118 route de Narbonne, F-31062 Toulouse Cedex 9 (France); Corazza, A, E-mail: ahmad.dagang@laplace.univ-tlse.f [SAES Getters S.p.A, Viale Italia, 20020 Lainate, Milan (Italy)

    2010-06-16

    In any discharges, the existence of impurities could cause a severe change or bring a negative or positive effect to the discharge and plasma characteristics. The authors purposely added a few kinds of impurities and investigated their effect on the discharge. The common and typical impurities of H{sub 2}, N{sub 2}, CO{sub 2} and CH{sub 4} were applied in varying concentration percentages into a xenon dielectric barrier discharge lamp. Their discharge condition, emission spectra and electrical characteristics were studied. The plasma generation differs from one type of impurity to another. With two different concentrations of hydrogen applied, at 5% concentration it would stabilize the discharge and at 0.5% concentration it would cause an additional collision process where a strong peak of atomic lines was observed. Nitrogen with two types of concentration, i.e. 1% and 0.1%, exhibits two kinds of characteristics in emission spectroscopy. From the electrical parameters, the voltage across the gap shows the lamps with impurities have a higher value compared with the pure xenon lamp.

  15. Understanding anode and cathode behaviour in high-pressure discharge lamps

    Science.gov (United States)

    Flesch, P.; Neiger, M.

    2005-09-01

    High-intensity discharge (HID) lamps have widespread and modern areas of application including general lighting, video/movie projection (e.g. UHP lamp), street/industrial lighting, and automotive headlight lamps (D2/xenon lamp). Even though HID lamps have been known for several decades now, the important plasma-electrode interactions are still not well understood. Because HID lamps are usually operated on ac (electrodes switch alternately from anode to cathode phase), time-dependent simulations including realistic and verified anode and cathode models are essential. Therefore, a recently published investigation of external laser heating of an electrode during anode and cathode phase in an operating HID lamp [28] provided the basis for our present paper. These measurements revealed impressive influences of the external laser heating on electrode fall voltage and electrode temperature. Fortunately, the effects are very different during anode and cathode phase. Thus, by comparing the experimental findings with results from our numerical simulations we can learn much about the principles of electrode behaviour and explain in detail the differences between anode and cathode phase. Furthermore, we can verify our model (which includes plasma column, hot plasma spots in front of the electrodes, constriction zones and near-electrode non-local thermal equilibrium-plasma as well as anode and cathode) that accounts for all relevant physical processes concerning plasma, electrodes and interactions between them. Moreover, we investigate the influence of two different notions concerning ionization and recombination in the near electrode plasma on the numerical results. This improves our physical understanding of near-electrode plasma likewise and further increases the confidence in the model under consideration. These results are important for the understanding and the further development of HID lamps which, due to their small dimensions, are often experimentally inaccessible

  16. Dimmable Electronic Ballast for a Gas Discharge Lamp

    Science.gov (United States)

    Raducanu, Marius; Hennings, Brian D.

    2013-01-01

    Titanium dioxide (TiO2) is the most efficient photocatalyst for organic oxidative degradation. TiO2 is effective not only in aqueous solution, but also in nonaqueous solvents and in the gas phase. It is photostable, biologically and chemically inert, and non-toxic. Low-energy UV light (approximately 375 nm, UV-A) can be used to photoactivate TiO2. TiO2 photocatalysis has been used to mineralize most types of organic compounds. Also, TiO2 photocatalysis has been effectively used in sterilization. This effectiveness has been demonstrated by its aggressive destruction of microorganisms, and aggressive oxidation effects of toxins. It also has been used for the oxidation of carbon monoxide to carbon dioxide, and ammonia to nitrogen. Despite having many attractive features, advanced photocatalytic oxidation processes have not been effectively used for air cleaning. One of the limitations of the traditional photocatalytic systems is the ballast that powers (lights) the bulbs. Almost all commercial off-the-shelf (COTS) ballasts are not dimmable and do not contain safety features. COTS ballasts light the UV lamp as bright as the bulb can be lit, and this results in shorter bulb lifetime and maximal power consumption. COTS magnetic ballasts are bulky, heavy, and inefficient. Several iterations of dimmable electronic ballasts have been developed. Some manifestations have safety features such as broken-bulb or over-temperature warnings, replace-bulb alert, logbulb operational hours, etc. Several electronic ballast boards capable of independently lighting and controlling (dimming) four fluorescent (UV light) bulbs were designed, fabricated, and tested. Because of the variation in the market bulb parameters, the ballast boards were designed with a very broad range output. The ballast boards can measure and control the current (power) for each channel.

  17. Numerical simulation of dc high-pressure discharge lamps including electrodes

    International Nuclear Information System (INIS)

    Flesch, P.; Neiger, M.

    2002-01-01

    The subject of this paper is a novel modelling method for dc operated high-pressure discharge lamps including both electrodes. No subdivisions of the discharge space into different regions (e.g. space charge layer, ionization zone, plasma column) is necessary. Starting from general diffusion equations, this goal is achieved by using a differential equation for a non-LTE electrical conductivity which is applicable for local thermal equilibrium (LTE) regions as well as non-LTE plasma regions close to electrodes. This novel approach is valid only for high-pressure conditions, where the product of electron mean free path and electric field is such that the mean energy gain of electrons is considerably less than the ionization energy of the discharge gas, so that the same local kinetic energy distribution can be assumed for the electron, the ion, and the neutral gas components anywhere within the discharge. Boundary conditions for this non-LTE electrical conductivity at cathode and anode are derived. We present modelling results for Hg- and Xe-discharge lamps (p≥1 MPa). Comparison with results from traditional models using plasma layers will be presented and discussed. Convective flow within the lamp is not included yet, as the emphasis of this paper is on the regions close to anode and cathode. (author)

  18. Development of a see-through hollow cathode discharge lamp for (Li/Ne) optogalvanic studies

    Science.gov (United States)

    Saini, V. K.; Kumar, P.; Sarangpani, K. K.; Dixit, S. K.; Nakhe, S. V.

    2017-09-01

    Development of a demountable and see-through hollow cathode (HC) discharge lamp suitable for optogalvanic (OG) spectroscopy is described. The design of the HC lamp is simple, compact, and inexpensive. Lithium, investigated rarely by the OG method, is selected for cathode material as its isotopes are important for nuclear industry. The HC lamp is characterized electrically and optically for discharge oscillations free OG effect. Strong OG signals of lithium as well as neon (as buffer gas) are produced precisely upon copper vapor laser pumped tunable dye laser irradiation. The HC lamp is capable of generating a clean OG resonance spectrum in the available dye laser wavelength scanning range (627.5-676 nm) obtained with 4-(Dicyanomethylene)-2-methyl-6-(4-dimethylaminostyryl)-4H-pyran dye. About 28 resonant OG lines are explicitly observed. Majority of them have been identified using j-l coupling scheme and assigned to the well-known neon transitions. One line that corresponds to wavelength near about 670.80 nm is assigned to lithium and resolved for its fine (2S1/2 → 2P1/2, 3/2) transitions. These OG transitions allow 0.33 cm-1 accuracy and can be used to supplement the OG transition data available from other sources to calibrate the wavelength of a scanning dye laser with precision at atomic levels.

  19. Investigating the outer-bulb discharge as ignition aid for automotive-HID lamps

    International Nuclear Information System (INIS)

    Bergner, A; Groeger, S; Hoebing, T; Ruhrmann, C; Mentel, J; Awakowicz, P; Hechtfischer, U; Tochadse, G

    2014-01-01

    This work considers the ignition process of mercury-free high-intensity discharge lamps used for car headlights. These lamps have to run-up fast. This is achieved with a high xenon pressure of about 15 bar (cold) in the inner bulb. The high filling-gas pressure causes an increased ignition voltage compared with lower-pressure lamps used in general-lighting applications. In this paper the possibility is investigated to reduce the ignition voltage by optimizing a dielectric-barrier discharge (DBD) in the outer bulb working as ignition aid. A special outer bulb was built up allowing gas exchange and adjustment of the gas pressure. For diagnostic purposes different electrical and optical methods are used, namely the recording of ignition voltage, ignition current and light emission by a photo-diode signal on nanosecond time scale as well as short-time photography by a intensified charge-coupled device camera. It was found that the DBD mainly generates a potential distribution within the lamp which supports ignition by an increase in the E-field in front of the electrodes and the wall. It is shown that this effect is distinctly more effective than UV radiation potentially emitted by the DBD. (paper)

  20. Microwave Photochemistry IV: Preparation of the Electrodeless Discharge Lamps for Photochemical Applications

    Czech Academy of Sciences Publication Activity Database

    Církva, Vladimír; Vlková, Leona; Relich, Stanislav; Hájek, Milan

    2006-01-01

    Roč. 179, 1-2 (2006), s. 229-233 ISSN 1010-6030 R&D Projects: GA AV ČR KSK4040110; GA ČR GA203/02/0879 Institutional research plan: CEZ:AV0Z40720504 Keywords : microwave photochemistry * electrodeless discharge lamp * uv/vis source Subject RIV: CC - Organic Chemistry Impact factor: 2.098, year: 2006

  1. Experimental and theoretical investigations on the warm-up of a high-pressure mercury discharge lamp

    International Nuclear Information System (INIS)

    Zalach, J.; Franke, St.; Schoepp, H.; Araoud, Z.; Charrada, K.; Zissis, G.

    2011-01-01

    Modern high-pressure discharge lamps are forced to provide instant light and hot relight capabilities - if possible at lower power units. A detailed understanding of the warm-up of high-pressure discharge lamps is therefore required. Complex fluid model codes were developed for the past years including more and more processes like two-dimensional treatment of convection trying to provide a more comprehensive and consistent description of high-pressure discharge lamps. However, there is a lack of experimental data to examine the performance of these models. This work provides a very complete set of geometrical, electrical, spectroscopic, and thermographic data according to the warm-up of a high-pressure mercury discharge lamp that is compared to the results of a state of the art fluid code. Quantitative agreement is achieved for single parameters like wall temperatures. But the paper also reveals the need for further investigations and improvements of the code.

  2. Resonance broadening of Hg lines as a density diagnostic in high intensity discharge lamps

    International Nuclear Information System (INIS)

    Lawler, J E

    2004-01-01

    The use of width measurements on resonance broadened lines of Hg as a density diagnostic in high intensity discharge (HID) lamps is reviewed and further developed in this paper. Optical depths of Hg I lines at 491.6 nm, 577.0 nm, and 1014 nm are computed as a function of temperature to confirm that these lines are optically thin in most HID lamps. The effect of quadratic and quartic radial temperature variation on the width of resonance broadened lines is computed for arc core temperatures from 4000 K to 7000 K. Such variations in temperature, and inverse variations in Hg density, are found to increase the line widths by less than 10% for 'side-on' emission measurements averaged over the arc radius. Theoretical profiles of resonance broadened spectral lines, both radially averaged and as a function of chord offset, are presented. Observations of resonance broadened lines in a metal-halide HID lamp are presented and analysed. It is concluded that the widths of resonance broadened lines provide a convenient and reliable diagnostic for the arc core Hg density but are generally not very sensitive to the radial temperature and Hg density gradient

  3. Fluorescent and high intensity discharge lamp use in chambers and greenhouses

    Energy Technology Data Exchange (ETDEWEB)

    Langhans, R.W. [Cornell Univ., Ithaca, NY (United States)

    1994-12-31

    Fluorescent and High Intensity Discharge lamps have opened up great opportunities for researchers to study plant growth under controlled environment conditions and for commercial growers to increase plant production during low/light periods. This report describes the advantages and disadvantages of using each lamp in growth chambers, growth rooms and greenhouses. Growth Chambers are small (3m x 4/m and smaller) walk-in or reach-in enclosures with programmable, accurate temperature, relative humidity (RH) and irradiance control over wide ranges. The intent of growth chambers was to replicate sunlight conditions and transfer research results directly to the greenhouse or outside. It was realized that sunlight and outside conditions could not be mimicked. Growth chambers are also used to study irradiance and spectral fluxes. Growth Rooms are usually large rooms (larger than 3m x 4m) with only lamp irradiance, but providing relatively limited ranges of environmental control (i.e., 10 to 30 C temperature, 50 to 90% RH and ambient to 1000 ppm CO{sub 2}), and commonly independent of outside conditions. Irradiance requirements for growth rooms are similar to those of growth chambers. Growth rooms are also used for growing a large number of plants in a uniform standard environment condition and in commercial horticulture for tissue culture, seed germination (plugs) and seedling growth. Greenhouses are designed to allow maximum sunlight penetration through the structure. Initially greenhouses were used to extend the growing season. Then as heating systems, and cooling systems improved, they were used year round. Low light during the winter months reduced plant growth, but with the advent of efficient lamps (HID and fluorescent) it became possible to increase growth to rates close to that in summer months. Supplementary lighting is used during low light periods of the year and anytime to ensure consistent total daily irradiance for research plants.

  4. [Microwave assisted UV electrodeless discharge lamp photochemical degradation of 4-chlorophenol in aquatic solutions].

    Science.gov (United States)

    Ai, Zhi-hui; Jiang, Jun-qing; Yang, Peng; Zhou, Tao; Lu, Xiao-hua

    2004-07-01

    A microwave assisted UV electrodeless discharge lamp system (MW/UV) was used for photo-degradation of 4CP simulated wastewater. In order to evaluate the degradation efficiency of 4CP, UV spectrophotometry and ion chromatography were used for determination of 4CP and Cl- respectively. The degradation rate in MW/UV system was higher than that in the UV system within 120min, which were 52.40% and 21.56% respectively. The degradation efficiency was improved by increasing pH value of the solution, aerating O2 gas, enhancing light intensity, or adding H2O2 oxidant. The degradation of 4CP under MW/UV accords with the first order kinetics equation.

  5. The Electrodeless Discharge Lamp: a Prospective Tool for Photochemistry - Part 4. Temperature- and Envelope Material-Dependent Emission Characteristics

    Czech Academy of Sciences Publication Activity Database

    Müller, P.; Klán, P.; Církva, Vladimír

    2003-01-01

    Roč. 158, č. 1 (2003), s. 1-5 ISSN 1010-6030 R&D Projects: GA ČR GA203/02/0879 Institutional research plan: CEZ:AV0Z4072921 Keywords : photochemistry * microwave * electrodeless discharge lamp Subject RIV: CC - Organic Chemistry Impact factor: 1.693, year: 2003

  6. Experimental investigation on large-area dielectric barrier discharge in atmospheric nitrogen and air assisted by the ultraviolet lamp.

    Science.gov (United States)

    Zhang, Yan; Gu, Biao; Wang, Wenchun; Wang, Dezhen; Peng, Xuwen

    2009-04-01

    In this paper, ultraviolet radiation produced by the ultraviolet lamp is employed to supply pre-ionization for the dielectric barrier discharge in N(2) or air at atmospheric pressure. The effect of the ultraviolet pre-ionization on improving the uniformity of the dielectric barrier discharge is investigated experimentally. The atmospheric pressure glow discharge of the large area (270 mm x 120 mm) is obtained successfully via the ultraviolet pre-ionization in atmospheric DBD in N(2) when the gas gap decrease to 3mm. Based on the emission spectra, the mechanism which ultraviolet pre-ionization improves the uniformity of the dielectric barrier discharge is discussed.

  7. Full Length Amelogenin Binds to Cell Surface LAMP-1 on Tooth Root/Periodontium Associated Cells

    Science.gov (United States)

    Zhang, Hai; Tompkins, Kevin; Garrigues, Jacques; Snead, Malcolm L.; Gibson, Carolyn W.; Somerman, Martha J.

    2010-01-01

    Objectives Lysosome-associated membrane protein-1 (LAMP-1) has been suggested to be a cell surface receptor for a specific amelogenin isoform, leucine-rich amelogenin peptide or LRAP. However, it is unclear if LAMP-1 is an amelogenin receptor for dental mesenchymal cells. The goal of this study was to determine if LAMP-1 serves as a cell surface binding site for full length amelogenin on tooth root/periodontium associated mesenchymal cells. Design Murine dental follicle cells and cementoblasts (OCCM-30) were cultured for 2 days followed by addition of full length recombinant mouse amelogenin, rp(H)M180. Dose-response (0 to 100 μg/ml) and time course (0 to 120 minutes) assays were performed to determine the optimal conditions for live cell surface binding using immuno-fluorescent microscopy. A competitive binding assay was performed to determine binding specificity by adding Emdogain (1 mg/ml) to the media. An antibody against LAMP-1 was used to detect the location of LAMP-1 on the cell surface and the pattern was compared to cell surface bound amelogenin. Both amelogenin and cell surface LAMP-1 were immuno-co-localized to compare the amount and distribution pattern. Results Maximum surface binding was achieved with 50 μg/ml of rp(H)M180 for 120 minutes. This binding was specific as demonstrated by competitive inhibition (79% lower) with the addition of Emdogain. The binding pattern for rp(H)M180 was similar to the distribution of surface LAMP-1 on dental follicle cells and cementoblasts. The high co-localization coefficient (0.92) for rp(H)M180 and LAMP-1 supports rp(H)M180 binding to cell surface LAMP-1. Conclusions The data from this study suggest that LAMP-1 can serve as a cell surface binding site for amelogenin on dental follicle cells and cementoblasts. PMID:20382373

  8. Optical and electrostatic potential investigations of electrical breakdown phenomena in a low-pressure gas discharge lamp

    Science.gov (United States)

    Gendre, M. F.; Haverlag, M.; Kroesen, G. M. W.

    2010-06-01

    The ignition phase is a critical stage in the operation of gas discharge lamps where the neutral gas enclosed between the electrodes undergoes a transformation from the dielectric state to a conducting phase, eventually enabling the production of light. The phenomena occurring during this phase transition are not fully understood and the related experimental studies are often limited to local optical measurements in environments prone to influencing these transient phenomena. In this work unipolar ignition phenomena at sub-kilovolt levels are investigated in a 3 Torr argon discharge tube. The lamp is placed in a highly controlled environment so as to prevent any bias on the measurements. A fast intensified CCD camera and a specially designed novel electrostatic probe are used simultaneously so as to provide a broad array of measured and computed parameters which are displayed in space-time diagrams for cross comparisons. Experiments show that three distinct phases exist during successful ignitions: upon the application of voltage a first ionization wave starts from the active electrode and propagates in the neutral gas towards the opposite electrode. A local front of high axial E field strength is associated with this process and causes a local ionization to occur, leading to the electrostatic charging of the lamp. Next, a second wave propagates from the ground electrode back towards the active electrode with a higher velocity, and in this process leads to a partial discharging of the lamp. This return stroke draws a homogeneous plasma column which eventually bridges both electrodes at the end of the wave propagation. At this point both electrode sheaths are formed and the common features of a glow discharge are observed. The third phase is an increase in the light intensity of the plasma column until the lamp reaches a steady-state operation. Failed ignitions present only the first phase where the first wave starts its propagation but extinguishes in the lamp

  9. Numerical investigation of symmetry breaking and critical behavior of the acoustic streaming field in high-intensity discharge lamps

    International Nuclear Information System (INIS)

    Baumann, Bernd; Schwieger, Joerg; Wolff, Marcus; Manders, Freddy; Suijker, Jos

    2015-01-01

    For energy efficiency and material cost reduction it is preferred to drive high-intensity discharge lamps at frequencies of approximately 300 kHz. However, operating lamps at these high frequencies bears the risk of stimulating acoustic resonances inside the arc tube, which can result in low frequency light flicker and even lamp destruction. The acoustic streaming effect has been identified as the link between high frequency resonances and low frequency flicker. A highly coupled three-dimensional multiphysics model has been set up to calculate the acoustic streaming velocity field inside the arc tube of high-intensity discharge lamps. It has been found that the velocity field suffers a phase transition to an asymmetrical state at a critical acoustic streaming force. In certain respects the system behaves similar to a ferromagnet near the Curie point. It is discussed how the model allows to investigate the light flicker phenomenon. Concerning computer resources the procedure is considerably less demanding than a direct approach with a transient model. (paper)

  10. Microwave Photocatalysis of Mono-Chloroacetic Acid over Nanoporous Titanium(IV) Oxide Thin Films Using Mercury Electrodeless Discharge Lamps

    Czech Academy of Sciences Publication Activity Database

    Církva, Vladimír; Žabová, Hana; Hájek, Milan

    2008-01-01

    Roč. 198, č. 1 (2008), s. 13-17 ISSN 1010-6030 R&D Projects: GA ČR GA104/06/0992; GA ČR GA104/07/1212 Institutional research plan: CEZ:AV0Z40720504 Keywords : microwave-assisted photocatalysis * electrodeless discharge lamp * mono-chloroacetic acid Subject RIV: CH - Nuclear ; Quantum Chemistry Impact factor: 2.362, year: 2008

  11. Hollow-Core Fiber Lamp

    Science.gov (United States)

    Yi, Lin (Inventor); Tjoelker, Robert L. (Inventor); Burt, Eric A. (Inventor); Huang, Shouhua (Inventor)

    2016-01-01

    Hollow-core capillary discharge lamps on the millimeter or sub-millimeter scale are provided. The hollow-core capillary discharge lamps achieve an increased light intensity ratio between 194 millimeters (useful) and 254 millimeters (useless) light than conventional lamps. The capillary discharge lamps may include a cone to increase light output. Hollow-core photonic crystal fiber (HCPCF) may also be used.

  12. Collective Phenomena In Volume And Surface Barrier Discharges

    Science.gov (United States)

    Kogelschatz, U.

    2010-07-01

    Barrier discharges are increasingly used as a cost-effective means to produce non-equilibrium plasmas at atmospheric pressure. This way, copious amounts of electrons, ions, free radicals and excited species can be generated without appreciable gas heating. In most applications the barrier is made of dielectric material. In laboratory experiments also the use of resistive, ferroelectric and semiconducting materials has been investigated, also porous ceramic layers and dielectric barriers with controlled surface conductivity. Major applications utilizing mainly dielectric barriers include ozone generation, surface cleaning and modification, polymer and textile treatment, sterilization, pollution control, CO2 lasers, excimer lamps, plasma display panels (flat TV screens). More recent research efforts are also devoted to biomedical applications and to plasma actuators for flow control. Sinu- soidal feeding voltages at various frequencies as well as pulsed excitation schemes are used. Volume as well as surface barrier discharges can exist in the form of filamentary, regularly patterned or laterally homogeneous discharges. Reviews of the subject and the older literature on barrier discharges were published by Kogelschatz (2002, 2003), by Wagner et al. (2003) and by Fridman et al. (2005). A detailed discussion of various properties of barrier discharges can also be found in the recent book "Non-Equilibrium Air Plasmas at Atmospheric Pressure" by Becker et al. (2005). The physical effects leading to collective phenomena in volume and surface barrier discharges will be discussed in detail. Special attention will be given to self-organization of current filaments. Main similarities and differences of the two types of barrier discharges will be elaborated.

  13. Radiative properties of ceramic metal-halide high intensity discharge lamps containing additives in argon plasma

    Science.gov (United States)

    Cressault, Yann; Teulet, Philippe; Zissis, Georges

    2016-07-01

    The lighting represents a consumption of about 19% of the world electricity production. We are thus searching new effective and environment-friendlier light sources. The ceramic metal-halide high intensity lamps (C-MHL) are one of the options for illuminating very high area. The new C-MHL lamps contain additives species that reduce mercury inside and lead to a richer spectrum in specific spectral intervals, a better colour temperature or colour rendering index. This work is particularly focused on the power radiated by these lamps, estimated using the net emission coefficient, and depending on several additives (calcium, sodium, tungsten, dysprosium, and thallium or strontium iodides). The results show the strong influence of the additives on the power radiated despite of their small quantity in the mixtures and the increase of visible radiation portion in presence of dysprosium.

  14. On the plasma confinement by acoustic resonance. An innovation for electrodeless high-pressure discharge lamps

    Science.gov (United States)

    Courret, Gilles; Nikkola, Petri; Wasterlain, Sébastien; Gudozhnik, Olexandr; Girardin, Michel; Braun, Jonathan; Gavin, Serge; Croci, Mirko; Egolf, Peter W.

    2017-08-01

    In an applied research project on the development of a pulsed microwave sulfur lamp prototype of 1 kW, we have discovered an amazing phenomenon in which the plasma forms a ball staying at the center of the bulb despite gravity, thus protecting the glass from melting. In this paper, it is shown that this results from an acoustic resonance in a spherical mode. Measurements of the plasma response to short pulses are presented showing beats at the spherical resonance. It is demonstrated that the beats could result from the simultaneous excitation of two normal modes with a frequency difference of approximately 1%. One of the two frequencies matches precisely the microwave pulses repetition, a little below 30 kHz. Thus this one is due to a forced oscillation, whereas the other one is due to a free oscillation. The phase velocity of sound was calculated as a function of temperature in order to find the series of temperatures at which a resonance would occur if the bulb were an isothermal solid sphere. The mean temperature inside the actual bulb was determined from the only doublet of this series, that has characteristic frequencies close enough to cause the observed beats. In addition, one of these two modes has a spherical symmetry that can explain the plasma ball formation. The obtained mean temperature is consistent with the direct measurements on the bulb surface as well as with the temperature in the core of a similar plasma found in the literature. We have also proposed a model of the resonance onset based on the acoustic dispersion and the sound amplification due to electromagnetic coupling.

  15. 78 FR 13566 - Energy Conservation Program for High-Intensity Discharge Lamps: Public Meeting and Availability...

    Science.gov (United States)

    2013-02-28

    ... conduct, such as the engineering analysis, the life-cycle cost (LCC) and payback period (PBP) analyses... engineering analysis focuses on selecting commercially available lamps that incorporate design options that.... Current Rulemaking Process III. Summary of the Analyses A. Engineering Analysis B. Markups To Determine...

  16. Characteristics of a nanosecond-barrier-discharge-pumped multiwave UV – VUV lamp on a mixture of argon, krypton and vapours of freon

    Energy Technology Data Exchange (ETDEWEB)

    Shuaibov, A K; Minya, A I; Hrytsak, R V; Gomoki, Z T [Uzhgorod National University, Uzhgorod (Ukraine)

    2015-02-28

    We present the results of investigation of the characteristics of a nanosecond-barrier-discharge-pumped multiwave lamp based on a gas mixture of Ar – Kr – CCl{sub 4}, which emits in the spectral range of 170 – 260 nm. The main emission bands in the lamp spectrum are ArCl (B → X) near 175 nm, KrCl (B → X) near 222 nm and Cl{sub 2} (D' → A') near 258 nm. The lamp intensity with respect to pressure, working mixture composition and pump regime is optimised. (uv - vuv emitters)

  17. Microwave discharge electrodeless lamps (MDEL). Part VII. Photo-isomerization of trans-urocanic acid in aqueous media driven by UV light from a novel Hg-free Dewar-like microwave discharge thermally-insulated electrodeless lamp (MDTIEL). Performance evaluation.

    Science.gov (United States)

    Horikoshi, Satoshi; Sato, Tatsuro; Sakamoto, Kazutami; Abe, Masahiko; Serpone, Nick

    2011-07-01

    A novel mercury-free Dewar-like (double-walled structure) microwave discharge thermally-insulated electrodeless lamp (MDTIEL) was fabricated and its performance evaluated using the photo-isomerization of trans-urocanic acid (trans-UA) in aqueous media as a test process driven by the emitted UV light when ignited with microwave radiation. The photo-isomerization processes trans-UA → cis-UA and cis-UA → trans-UA were re-visited using light emitted from a conventional high-pressure Hg light source and examined for the influence of UV light irradiance and solution temperature; the temperature dependence of the trans → cis process displayed a negative activation energy, E(a) = -1.3 cal mol(-1). To control the photo-isomerization of urocanic acid from the heat usually dissipated by a microwave discharge electrodeless lamp (single-walled MDEL), it was necessary to suppress the microwave-initiated heat. For comparison, the gas-fill in the MDEL lamp, which typically consists of a mixture of Hg and Ar, was changed to the more eco-friendly N(2) gas in the novel MDTIEL device. The dynamics of the photo-isomerization of urocanic acid driven by the UV wavelengths of the N(2)-MDTIEL light source were compared to those from the more conventional single-walled N(2)-MDEL and Hg/Ar-MDEL light sources, and with those from the Hg lamp used to irradiate, via a fiber optic, the photoreactor located in the wave-guide of the microwave apparatus. The heating efficiency of a solution with the double-walled N(2)-MDTIEL was compared to the efficiency from the single-walled N(2)-MDEL device. Advantages of N(2)-MDTIEL are described from a comparison of the dynamics of the trans-UA → cis-UA process on the basis of unit surface area of the lamp and unit power consumption. The considerably lower temperature on the external surface of the N(2)-MDTIEL light source should make it attractive in carrying out photochemical reactions that may be heat-sensitive such as the photothermochromic

  18. New Copolymers Containing Charge Carriers for Organic Devices with ITO Films Treated by UV-Ozone Using High Intensity Discharge Lamp

    Directory of Open Access Journals (Sweden)

    Emerson Roberto SANTOS

    2009-02-01

    Full Text Available For electroluminescent devices new copolymers were synthesized using a Suzuki cross-coupling reaction based on monomers (fluorine-alt-phenylene in conjugation with quinoline-alt-phenylene units. They were characterized by 1H NMR, 13C NMR and FTIR. TGA measurements indicated that the copolymers have good thermal properties and no weight loss was observed up to 250 °C. The UV-Vis spectra were characterized by absorptions from the fluorene-alt-phenylene and quinoline-alt-phenylene segments in the backbone, while their photoluminescence (PL spectra dominated by emissions from the fluorene excimer. For devices assembly ITO films were treated using a High Intensity Discharge Lamp (HPMVL without outer bulb presenting high ozone concentration than that conventional germicidal lamp. The device with ITO treated revealed significant decrease of threshold voltage (or turn-on voltage compared by untreated with I-V curves. This decrease can be related by water and carbon dioxide extracted on surface after UV-Ozone treatment revealed by DRIFT measurements.

  19. Time-dependent simulation of plasma and electrodes in high-intensity discharge lamps with different electrode shapes

    International Nuclear Information System (INIS)

    Flesch, P; Neiger, M

    2003-01-01

    The subject of this paper is the modelling of d.c. and a.c. high-intensity Hg-discharge lamps with differently shaped electrodes. Different arc attachments on the electrodes are studied and insight for the development of new electrodes is gained. The model includes the entire discharge plasma (plasma column, hot plasma spots in front of electrodes, near-electrode non-LTE-plasma) as well as anode and cathode. No subdivision of the discharge space into different regions is necessary (like space charge layer, ionization zone, plasma column). This is achieved by using a differential equation for a non-LTE electrical conductivity which is applicable for local thermal equilibrium (LTE-)regions as well as for non-LTE plasma regions close to the electrodes in a high pressure plasma. Modelling results for a 0.6 MPa mercury discharge considering six different electrode shapes (anode and cathode) are presented and compared with experimental results. The electrodes have different diameters and different electrode tips, such as hemispherical, flat, or conical tip with 60 deg. or 90 deg. apex angle. Furthermore, an electrode with a larger diameter in the mid section of the rod is investigated

  20. Measurement and modeling of nitrogen resonance line profiles from an electrodeless discharge lamp

    International Nuclear Information System (INIS)

    Wood, D.R.; Skinner, G.B.; Lifshitz, A.

    1987-01-01

    Experimental profiles of the 1200 A resonance triplet of atomic nitrogen were measured for a variety of operating conditions of an end-on electrodeless lamp, and corresponding absorption curves were calculated. Each source profile was determined by fitting parameters to an empirical two-layer model, then convoluting with the instrumental function for comparison with experimental data. Each three-component profile was fitted with three adjustable parameters: an absorption parameter for each of the two layers and a third absorption parameter to adjust for radiation trapping. Curves of absorption as a function of atom concentration, calculated from these profiles, are very similar to the shock tube calibrations of Thielen and Roth in which a source of similar design has been used

  1. Removal of Refractory Organics from Biologically Treated Landfill Leachate by Microwave Discharge Electrodeless Lamp Assisted Fenton Process

    Directory of Open Access Journals (Sweden)

    Jiuyi Li

    2015-01-01

    Full Text Available Biologically treated leachate usually contains considerable amount of refractory organics and trace concentrations of xenobiotic pollutants. Removal of refractory organics from biologically treated landfill leachate by a novel microwave discharge electrodeless lamp (MDEL assisted Fenton process was investigated in the present study in comparison to conventional Fenton and ultraviolet Fenton processes. Conventional Fenton and ultraviolet Fenton processes could substantially remove up to 70% of the refractory organics in a membrane bioreactor treated leachate. MDEL assisted Fenton process achieved excellent removal performance of the refractory components, and the effluent chemical oxygen demand concentration was lower than 100 mg L−1. Most organic matters were transformed into smaller compounds with molecular weights less than 1000 Da. Ten different polycyclic aromatic hydrocarbons were detected in the biologically treated leachate, most of which were effectively removed by MDEL-Fenton treatment. MDEL-Fenton process provides powerful capability in degradation of refractory and xenobiotic organic pollutants in landfill leachate and could be adopted as a single-stage polishing process for biologically treated landfill leachate to meet the stringent discharge limit.

  2. Photochemically induced deposition of protective alumina coatings onto UV emitting phosphors for Xe excimer discharge lamps

    Energy Technology Data Exchange (ETDEWEB)

    Broxtermann, Mike, E-mail: mike.b@fh-muenster.de; Jüstel, Thomas, E-mail: tj@fh-muenster.de

    2016-08-15

    Highlights: • A UV-reactor for the pH induced precipitation of inorganic material is described. • The photolysis of Azide (N{sub 3}{sup −}) leads to a steady pH increase used for precipitation. • A UV induced Al(OH){sub 3} precipitation is used to craft Al{sub 2}O{sub 3} coatings onto YPO{sub 4}:Bi. • The influence of Al{sub 2}O{sub 3} coated onto YPO{sub 4}:Bi with different thicknesses is discussed. • SEM, VUV-spectroscopy and ESA measurements were performed on Al{sub 2}O{sub 3} coated samples. - Abstract: This work concerns the particle coating of the UV-C emitting phosphor YPO{sub 4}:Bi, targeting a stability enhancement of the phosphor material for Xe excimer lamp operation. To this end, the material is coated by the wide band gap material Al{sub 2}O{sub 3}. In order to obtain a thin and homogeneous coating layer, a novel process based on the photochemical cleavage of NaN{sub 3} in water was developed. This results in a slow and continuous enhancement of the pH value due to ongoing NaOH formation, which results in the precipitation of Al(OH){sub 3} from an Al{sub 2}(SO{sub 4}){sub 3} {sub ×} 18H{sub 2}O solution. It turned out that the obtained particle coatings are of much better quality, i.e. homogeneity, compared to coatings made from a wet-chemical homogeneous precipitation process. The morphology and electrochemical properties of Al{sub 2}O{sub 3} coated YPO{sub 4}:Bi are discussed on the basis of optical spectroscopy, ESA measurements, and SEM/EDX investigations.

  3. Radiative characteristics and kinetics of processes in low-pressure gas-discharge lamps based on a mixture of helium and iodine vapors

    Science.gov (United States)

    Shuaibov, A. K.; Gomoki, Z. T.; Kalyuzhnaya, A. G.; Shchedrin, A. I.

    2010-11-01

    The UV radiation of glow- and capacitive-discharge lamps based on mixtures of inert gases with iodine vapors are optimized in the spectral range of 175-360 nm, in which working helium-iodine mixtures of different compositions are used. The most intense spectral lines in the bactericidal region of the spectrum were the atomic lines of iodine (183.0, 206.2 nm), and in the region of 320-360 nm, emission of the spectral band of an iodine molecule prevailed with a maximum at λ = 342 nm. For a capacitive lamp with a casing opaque in the spectral range λ iodine molecule with a maximum at 342 nm. The emission brightness of this lamp is optimized in iodine molecule transitions depending on the partial helium pressure. We present the results of simulating the kinetics of processes in a glow-discharge plasma in mixtures of He, Xe, and iodine vapors. We establish the dependence of the main part of the emission intensity of the 206.2 nm spectral line of an iodine atom and the 342 nm band of an iodine molecule on the helium pressure in a glow-discharge lamp operating on a He-I2 mixture.

  4. Influence of the gas mixture radio on the correlations between the excimer XeCl emission and the sealed gas temperature in dielectric barrier discharge lamps

    CERN Document Server

    Xu Jin Zhou; Ren Zhao Xing

    2002-01-01

    For dielectric barrier discharge lamps filled with various gas mixture ratios, the correlations between the excimer XeCl emission and the sealed gas temperature have been founded, and a qualitative explication is presented. For gas mixture with chlorine larger than 3%, the emission intensity increases with the sealed gas temperature, while with chlorine about 2%, the emission intensity decreases with the increasing in the gas temperature, and could be improved by cooling water. However, if chlorine is less than 1.5%, the discharge appears to be a mixture mode with filaments distributed in a diffused glow-like discharge, and the UV emission is independent on the gas temperature

  5. Dielectric Barrier Discharge based Mercury-free plasma UV-lamp for efficient water disinfection.

    Science.gov (United States)

    Prakash, Ram; Hossain, Afaque M; Pal, U N; Kumar, N; Khairnar, K; Mohan, M Krishna

    2017-12-12

    A structurally simple dielectric barrier discharge based mercury-free plasma UV-light source has been developed for efficient water disinfection. The source comprises of a dielectric barrier discharge arrangement between two co-axial quartz tubes with an optimized gas gap. The outer electrode is an aluminium baked foil tape arranged in a helical form with optimized pitch, while the inner electrode is a hollow aluminium metallic rod, hermetically sealed. Strong bands peaking at wavelengths 172 nm and 253 nm, along with a weak band peaking at wavelength 265 nm have been simultaneously observed due to plasma radiation from the admixture of xenon and iodine gases. The developed UV source has been used for bacterial deactivation studies using an experimental setup that is an equivalent of the conventional house-hold water purifier system. Deactivation studies for five types of bacteria, i.e., E. coli, Shigella boydii, Vibrio, Coliforms and Fecal coliform have been demonstrated with 4 log reductions in less than ten seconds.

  6. Microwave Photocatalysis IV: Effects of Additional Operational Parameters on the Microwave Photocatalytic Degradation of Mono-Chloroacetic Acid Using Titania-Coated Mercury Electrodeless Discharge Lamps

    Czech Academy of Sciences Publication Activity Database

    Kmentová, Hana; Církva, Vladimír

    2013-01-01

    Roč. 88, č. 6 (2013), s. 1109-1113 ISSN 0268-2575 R&D Projects: GA ČR GA104/07/1212; GA ČR GD203/08/H032 Institutional support: RVO:67985858 Keywords : microwave photocatalysis * titania thin film * mercury electrodeless discharge lamp Subject RIV: CH - Nuclear ; Quantum Chemistry Impact factor: 2.494, year: 2013

  7. Multipactor Discharge on Metal and Dielectric Surfaces

    Science.gov (United States)

    Kishek, R. A.

    1997-11-01

    Multipactor is a recurrent rf breakdown phenomenon based on secondary electron emission. It occurs in a wide range of devices when the electron trajectories due to the applied rf are resonant with structures such as accelerators, coherent radiation sources, satellites, and ECRH/ICRH antennas. A simple model is used to study the temporal evolution of a first-order, two-surface multipactor discharge and its interaction with the surrounding rf structure. The loading of the structure by the changing multipactor current, a combination of de-tuning and of reducing the quality factor of the resonant structure, is found to cause saturation. A novel phase focusing mechanism is discovered in which the electrostatic repulsion among the space charge may result in the multipactor electrons being very tightly bunched. The theory predicts the parameter range over which a steady-state, 2-surface multipactor may occur, linking material properties to the dynamics of the discharge(R. A. Kishek, Y. Y. Lau, and D. Chernin, Phys. Plasmas 4, 863 (1997).). The analytic theory is in excellent agreement with the computational results of the model and is applied to documented experimental observations of multipactor. On a dielectric (such as an rf window), multipactor poses a different kind of problem. Charge accumulation on the dielectric sets up a DC electric field which affects the dynamics of the discharge. Monte Carlo simulations are used to construct susceptibility diagrams for a wide range of materials that will allow an immediate assessment of the range of rf power over which multipactor may be expected to occur.

  8. Surface dosimetry in phototherapy: comparison of three ultraviolet B lamps used in the treatment of psoriasis

    International Nuclear Information System (INIS)

    Snow, J.L.; Muller, S.A.

    1996-01-01

    The quantitation (dosimetry) of ultraviolet B irradiation (UVB) administered during phototherapy for psoriasis is fundamental to this modality of treatment because only absorbed irradiation can cause a photochemical reaction and, hence, a phototherapeutic effect. Significant differences may exist in surface dosimetry achieved with different UVB irradiators, and this could have important consequences for the observed clinical efficacy of phototherapy as well as practical implications for avoiding burning when transferring patients between systems. Multiple anatomically referenced polysulphone photodosimeters were applied to the skin of five subjects receiving treatment for severe psoriasis. Three subjects were irradiated with both a free-standing hot quartz lamp and a fluorescent cabinet. Two others were irradiated with a flat bank of fluorescent tubes. Topographical maps of surface irradiation were constructed. 'Cold' areas ( 100% of stated dose) included the forearms and posterior thighs for the hot quartz lamp; the lateral arms, dorsal forearm, and abdomen for the cabinet; and the central trunk (anterior and posterior) for the bank of tubes. Thus, striking differences in surface irradiation exist among the three UVB irradiators studied, and this has an impact on the results of phototherapy for psoriasis. (author)

  9. Hollow hexagonal pattern with surface discharges in a dielectric barrier discharge

    Science.gov (United States)

    Feng, Jianyu; Dong, Lifang; Li, Caixia; Liu, Ying; Du, Tian; Hao, Fang

    2017-05-01

    The hollow hexagonal pattern involved in surface discharges is firstly investigated in a dielectric barrier discharge system. The spatiotemporal structures of the pattern are studied using an intensified charge-coupled device and photomultiplier. Instantaneous images taken by an intensified charge-coupled device and optical correlation measurements show that the surface discharges are induced by volume discharges. The optical signals indicate that the discharge filaments constituting the hexagonal frame discharge randomly at the first current pulse or the second pulse, once or twice. There is no interleaving of several sub-lattices, which indicates that the ‘memory’ effect is no longer in force due to surface discharges. By using the emission spectrum method, both the molecule vibration temperature and electron density of the surface discharges are larger than that of the volume discharges.

  10. Radiative properties of Ceramic Metal-Halide High Intensity Discharge lamps (CMH) containing additives in argon plasma

    Science.gov (United States)

    Cressault, Yann; Teulet, Philippe; Zissis, Georges; Laplace Team

    2015-09-01

    The lighting represents a consumption of about 19% of the world electricity production. We are thus searching new effective and environment-friendlier light sources. The Ceramic Metal-Halide High Intensity Lamps (CMH) are one of the options for illuminating very high area. The new CMH lamps are mercury free and contain additives species which lead to a richer spectrum in specific spectral intervals, a better colour temperature or colour rendering index. This work is particularly focused on the power radiated by these lamps, estimated using the Net Emission Coefficient, and depending on several additives (calcium, sodium, tungsten, dysprosium, thallium or strontium).

  11. Surface analysis by glow discharge spectrometry: cathode zone and sputtering yield

    International Nuclear Information System (INIS)

    Ohannessian, L.

    1986-01-01

    Applications of the glow discharge optical spectroscopy for surface analysis are numerous. Moreover, this method enables to get qualitative and semi-quantitative results which are already significant. However, we should improve our knowledge of the physical parameters involved in the glow discharge lamp mechanisms and learn to handle such phenomena. The problems can be divided into two categories: sputtering of the target under argon ions accelerated in the cathode dark space, and luminous emission of torn away species which reach the negative glow region. Our aim was to take stock of the present theoretical knowledge which can be applied to the specific self-maintained glow discharge plasma. Moreover, we tried to link together (often roughly) the basic discharge parameters, i.e. current intensity I, voltage of the lamp Vg, pressure of the gas p. Specially a comparison between theoretical and experimental results was established concerning the pure target sputtering yields. The contribution of the argon ions striking the cathode is estimated taking into account their energetic distribution. The role of the fast argon neutrals produced by charge exchange with the ions is important; we evaluated their energetic distribution and their contribution to sputtering. The total theoretical sputtering yield is inferred: the comparison with experimental results is presented. The role of the gas temperature is emphasized [fr

  12. Study of the cathode region of mercury-free He-Xe low-pressure gas-discharge lamps with planar mesh electrode; Untersuchung der Kathodenregion von quecksilberfreien He-Xe Niederdruckgasentladungslampen mit planarer Geflechtelektrode

    Energy Technology Data Exchange (ETDEWEB)

    Winter, Joern

    2009-12-04

    In the present work the cathode region of a mercury-free helium-xenon low pressure discharge in spot mode was experimentally investigated. Due to the emission of electrons, the production of ions and metastable atoms as well as lifetime limiting processes the cathode region is of particular interest. To implement a discharge in spot mode a novel planar mesh electrode was developed and used as cathode. Applying the space resolved laser-atom-absorption-spectroscopy method (LAAS) the absolute particle densities of the two lowest excited xenon atoms and the gas temperature in the cathode region were determined, whereas the strong spot plasma inhomogeneity was considered. Both the excited xenon particle density and the gas temperature strongly decrease in radial and axial direction. Particularly the gas temperature has a value of about 650 K in a 1mm cathode distance and does clearly exceed room temperature. Furthermore the spectrum of the hot spot on the cathode surface was detected by means of optical emission spectroscopy. From this spectrum the temperature distribution of the cathode spot was obtained by fitting Planck's law. The temperature distribution shows a distinct maximum, which in dependence of the discharge current reaches values of 1414 K at 40 mA and 1524 K at 80 mA. From that maximum a steep direction-independent temperature decrease was obtained. A technological important aspect concerning the lifetime of a xenon based mercury-free discharge lamp is the problematic effect of the xenon gas consumption. In this work it is shown that in contrary to an industrial made standard cup electrode, which is broadly used in light advertising lamps, the gas consumption is negligible when applying the novel planar mesh electrode. This reduction of gas consumption is due to the generation of a hot spot along with high cathode temperature and low cathode fall voltage. (orig.)

  13. Lamp bulb with integral reflector

    Science.gov (United States)

    Levin, Izrail; Shanks, Bruce; Sumner, Thomas L.

    2001-01-01

    An improved electrodeless discharge lamp bulb includes an integral ceramic reflector as a portion of the bulb envelope. The bulb envelope further includes two pieces, a reflector portion or segment is cast quartz ceramic and a light transmissive portion is a clear fused silica. In one embodiment, the cast quartz ceramic segment includes heat sink fins or stubs providing an increased outside surface area to dissipate internal heat. In another embodiment, the quartz ceramic segment includes an outside surface fused to eliminate gas permeation by polishing.

  14. Routine Isotopic Analysis of 235U by Emission Spectrometry. 1. Interferometry using electrode-less discharge lamps 2. determination of the 235U/238U ratio using a spectrograph and electrode-less lamps

    International Nuclear Information System (INIS)

    Capitini, R.; Ceccaldi, M.; Leicknam, J.P.; Rabec, J.

    1968-01-01

    I. A 'HYPEAC' interferometric apparatus has been used for routine determination of uranium 235. In order to facilitate the examination of non-metallic samples and to reduce the time required for analysis it has been necessary to replace the hollow-cathode light sources usually used by electrode-less discharge lamps. The preparation outside the apparatus of such lamps containing uranium tetrachloride is described; the process is simple and rapid: about ninety minutes for each, and several lamps can be built simultaneously, thus reducing still further the total time required for each analysis. The amount of sample required is about a few milligrams. In order to counteract any spontaneous optical dis-adjustment which could prevent the application of the usual isotopic abundance method, it is necessary to compare the sample spectra with those of standards, all these spectra being recorded successively and alternately. A series of examples of determinations involving over 150 measurements is presented and discussed. For samples with abundances similar to that of natural uranium and up to 5 per cent of the 235 isotope., the reproducibility is of the order of 2 per cent, the relative accuracy being ± 2 to 3 per cent; for samples enriched in uranium 235 (5 to 93 per cent) the relative accuracy can attain ± 0.5 per cent. II. In spite of the large amount of research into the improvement of the accuracy of uranium isotope analyses using optical methods, it has not been possible up to the present to develop a method as good as mass spectrometry. When it is not necessary to have a high accuracy, however, emission spectroscopy which has no memory effect can constitute a complementary method of analysis if it is sufficiently fast and economical; for this to happen it seems to us that it should be possible to apply such a method in laboratories equipped with all the usual spectrochemical analysis equipment. In the present work we have therefore set out to obtain an acceptable

  15. Surface modification of steels by electrical discharge treatment in electrolyte

    International Nuclear Information System (INIS)

    Krastev, D.; Paunov, V.; Yordanov, B.; Lazarova, V.

    2013-01-01

    Full text: In this work are discussed some experimental data about the influence of applied electrical discharge treatment in electrolyte on the surface structure of steels. The electrical discharge treatment of steel surface in electrolyte gives a modified structure with specific combination of characteristics in result of nonequilibrium transformations. The modification goes by a high energy thermal process in a very small volume on the metallic surface involving melting, vaporisation, activation and alloying in electrical discharges, and after that cooling of this surface with high rate in the electrolyte. The surface layers obtain a different structure in comparison with the metal matrix and are with higher hardness, wear resistance and corrosion resistance. key words: surface modification, electrical discharge treatment in electrolyte, steels

  16. Application of MEVVA discharge to material surface modification

    International Nuclear Information System (INIS)

    Gao Yu; Geng Man; Huang Yuming; Gong Xiaorong; Yu Yijun; Tang Deli; Tie Jun

    1996-01-01

    The authors describes some characteristics of the MEVVA discharge, the process of generating a cathode-arc plasma and the advantages of the MEVVA discharge compared with the kind of heating-vaporizing-ionizing source. Some practical parameters and the operating process of the MEVVA ion source as well as a plasma source with MEVVA discharge used in a PSII device are presented. Various plasmas having good-quality and high-performance are obtained with MEVVA discharges and have been widely used in sight-line processing and omnibearing ion implantation for material surface modification

  17. Properties of water surface discharge at different pulse repetition rates

    International Nuclear Information System (INIS)

    Ruma,; Yoshihara, K.; Hosseini, S. H. R.; Sakugawa, T.; Akiyama, H.; Akiyama, M.; Lukeš, P.

    2014-01-01

    The properties of water surface discharge plasma for variety of pulse repetition rates are investigated. A magnetic pulse compression (MPC) pulsed power modulator able to deliver pulse repetition rates up to 1000 Hz, with 0.5 J per pulse energy output at 25 kV, was used as the pulsed power source. Positive pulse with a point-to-plane electrode configuration was used for the experiments. The concentration and production yield of hydrogen peroxide (H 2 O 2 ) were quantitatively measured and orange II organic dye was treated, to evaluate the chemical properties of the discharge reactor. Experimental results show that the physical and chemical properties of water surface discharge are not influenced by pulse repetition rate, very different from those observed for under water discharge. The production yield of H 2 O 2 and degradation rate per pulse of the dye did not significantly vary at different pulse repetition rates under a constant discharge mode on water surface. In addition, the solution temperature, pH, and conductivity for both water surface and underwater discharge reactors were measured to compare their plasma properties for different pulse repetition rates. The results confirm that surface discharge can be employed at high pulse repetition rates as a reliable and advantageous method for industrial and environmental decontamination applications.

  18. Computer modelling of a short-pulse excited dielectric barrier discharge xenon excimer lamp (lambda approx 172 nm)

    CERN Document Server

    Carman, R J

    2003-01-01

    A detailed rate-equation analysis has been used to simulate the plasma kinetics in a pulsed-excited dielectric barrier discharge in xenon, under operating conditions where the discharge structure is spatially homogeneous. The one-dimensional model, incorporating 14 species and 70 reaction processes, predicts results that are in good agreement with experimental measurements of the electrical characteristics, and optical (vacuum-ultraviolet (VUV) and visible) pulse shapes. The model reveals that electrical breakdown of the discharge gap occurs via a fast-moving ionization/excitation wavefront that starts close to the anode dielectric and propagates towards the cathode at approx 3x10 sup 5 m s sup - sup 1. The wavefront appears as a result of successive avalanches of electrons that propagate across the discharge gap after release from the cathode dielectric. During breakdown, the mean electron energy in the bulk plasma is close to optimum for preferential excitation of the Xe* 1s sub 4 sub , sub 5 states that fe...

  19. Note: Hollow cathode lamp with integral, high optical efficiency isolation valve: A modular vacuum ultraviolet source

    International Nuclear Information System (INIS)

    Sloan Roberts, F.; Anderson, Scott L.

    2013-01-01

    The design and operating conditions of a hollow cathode discharge lamp for the generation of vacuum ultraviolet radiation, suitable for ultrahigh vacuum (UHV) application, are described in detail. The design is easily constructed, and modular, allowing it to be adapted to different experimental requirements. A thin isolation valve is built into one of the differential pumping stages, isolating the discharge section from the UHV section, both for vacuum safety and to allow lamp maintenance without venting the UHV chamber. The lamp has been used both for ultraviolet photoelectron spectroscopy of surfaces and as a “soft” photoionization source for gas-phase mass spectrometry

  20. Note: Hollow cathode lamp with integral, high optical efficiency isolation valve: A modular vacuum ultraviolet source

    Science.gov (United States)

    Sloan Roberts, F.; Anderson, Scott L.

    2013-12-01

    The design and operating conditions of a hollow cathode discharge lamp for the generation of vacuum ultraviolet radiation, suitable for ultrahigh vacuum (UHV) application, are described in detail. The design is easily constructed, and modular, allowing it to be adapted to different experimental requirements. A thin isolation valve is built into one of the differential pumping stages, isolating the discharge section from the UHV section, both for vacuum safety and to allow lamp maintenance without venting the UHV chamber. The lamp has been used both for ultraviolet photoelectron spectroscopy of surfaces and as a "soft" photoionization source for gas-phase mass spectrometry.

  1. Modelling of the initial stage of the surface discharge development

    International Nuclear Information System (INIS)

    Gibalov, V.; Pietsch, G.

    1998-01-01

    Computer modelling of the initial stage of the surface discharge was performed by solving numerically the coupled continuity, the Poisson and Townsend ionization equations and taking into account the ionization, attachment and detachment processes. The potential distribution at the dielectric surface and at the boundaries which surround the integration region have been calculated with the charge-image method in a 3D approach. In order to eliminate numerical diffusion effects, the solution of the continuity equation was corrected using a flux correction transport routine. At the positive voltage the development of the discharge channel is determined mainly by the shape of the electrode tip. At the negative voltage the following phases of the discharge may be distinguished: the initial phase, the cathode directed streamer phase resulting in the cathode layer formation, and the propagating phase. The physical processes governing each discharge phase are described in detail. (J.U.)

  2. Impacts of thermal and chemical discharges to surface water

    International Nuclear Information System (INIS)

    Stober, Q.J.

    1974-01-01

    Various aspects of thermal and chemical discharges to surface water are outlined. The major impacts of nuclear power plants on aquatic resources are disruption during construction, intake of cooling water, discharge problems, and interactions with other water users. The following topics are included under the heading, assessment of aquatic ecology: identification of flora and fauna; abundance of aquatic organisms; species-environment relationships; and identification of pre-existing environmental stress. The following topics are included under the heading, environmental effects of plant operation: entrapment of fish by cooling water; passage of plankton through cooling system; discharge area and thermal plume; chemical effluents; and plant construction. (U.S.)

  3. Using a nitrogen dielectric barrier discharge for surface treatment

    International Nuclear Information System (INIS)

    Borcia, G; Anderson, C A; Brown, N M D

    2005-01-01

    In this paper, continuing previous work, we report on the installation and the testing of an experimental dielectric barrier discharge (DBD) reactor run in a controlled atmospheric pressure gaseous environment other than air. Here, the effects of a N 2 -DBD treatment on the surface of a test polymer material (UHMW polyethylene) are examined, reported, discussed and compared to results obtained previously following air-DBD treatment. Surface analysis and characterization were performed using x-ray photoelectron spectroscopy, contact angle measurement and scanning electron microscopy before and following the DBD processing described. The discharge parameters used were correlated with the changes in the surface characteristics found following DBD treatments of various durations in a nitrogen atmosphere. The work focuses on the control of the gaseous environment supporting the discharge and on the possibility of overcoming the potentially dominant effect of reactive oxygen-related species, derived from any residual air present. The results obtained underline the very high reactivity of such species in the discharge, but are encouraging in respect of the possibility of the implantation or generation of functional groups other than oxygen-related ones at the surface of interest. The processing conditions concerned simulate 'real' continuous high speed processing, allowing the planning of further experiments, where various gaseous mixtures of the type X + N 2 will be used for controlled surface functionalization

  4. Efficient mineralization of antibiotic ciprofloxacin in acid aqueous medium by a novel photoelectro-Fenton process using a microwave discharge electrodeless lamp irradiation.

    Science.gov (United States)

    Wang, Aimin; Zhang, Yanyu; Zhong, Huihui; Chen, Yu; Tian, Xiujun; Li, Desheng; Li, Jiuyi

    2018-01-15

    In this study, a novel photoelectro-Fenton (PEF) process using microwave discharge electrodeless lamp (MDEL) as a UV irradiation source was developed for the removal of antibiotic ciprofloxacin (CIP) in water. Comparative degradation of 200mgL -1 CIP was studied by direct MDEL photolysis, anodic oxidation (AO), AO in presence of electrogenerated H 2 O 2 (AO-H 2 O 2 ), AO-H 2 O 2 under MDEL irradiation (MDEL-AO-H 2 O 2 ), electro-Fenton (EF) and MDEL-PEF processes. Higher oxidation power was found in the sequence: MDEL photolysis < AO < AO-H 2 O 2 < MDEL-AO-H 2 O 2 < EF < MDEL-PEF. Effects of current density, pH, initial Fe 2+ concentration and initial CIP concentration on TOC removal in MDEL-PEF process were examined, and the optimal conditions were ascertained. The releases of three inorganic ions (F - , NH 4 + and NO 3 - ) and two carboxylic acids (oxalic and formic acids) were qualified. Seven aromatic intermediates mainly generated from hydroxylation, dealkylation and defluorination of CIP were detected by UPLC-QTOF-MS/MS technology. Therefore, plausible degradation sequences for CIP degradation in MDEL-PEF process including all detected products were proposed. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Target surface condition during reactive glow discharge sputtering of copper

    International Nuclear Information System (INIS)

    Depla, D; Haemers, J; Gryse, R De

    2002-01-01

    During reactive glow discharge sputtering of copper in an argon/nitrogen plasma, we noticed an abrupt change of the target voltage and the deposition rate when the nitrogen concentration in the plasma exceeds a critical value. To explain this behaviour, the target surface after reactive glow discharge sputtering was examined by x-ray photoelectron spectroscopy (XPS). An experimental arrangement was constructed that allows direct transfer of the glow discharge cathode to the XPS analysis chamber without air exposure. These XPS measurements revealed that several different chemical states of nitrogen are present in the layer that forms on the target surface. The relative concentration of these different states changes when the critical nitrogen concentration in the plasma is exceeded

  6. Electric field vector measurements in a surface ionization wave discharge

    International Nuclear Information System (INIS)

    Goldberg, Benjamin M; Adamovich, Igor V; Lempert, Walter R; Böhm, Patrick S; Czarnetzki, Uwe

    2015-01-01

    This work presents the results of time-resolved electric field vector measurements in a short pulse duration (60 ns full width at half maximum), surface ionization wave discharge in hydrogen using a picosecond four-wave mixing technique. Electric field vector components are measured separately, using pump and Stokes beams linearly polarized in the horizontal and vertical planes, and a polarizer placed in front of the infrared detector. The time-resolved electric field vector is measured at three different locations across the discharge gap, and for three different heights above the alumina ceramic dielectric surface, ∼100, 600, and 1100 μm (total of nine different locations). The results show that after breakdown, the discharge develops as an ionization wave propagating along the dielectric surface at an average speed of 1 mm ns −1 . The surface ionization wave forms near the high voltage electrode, close to the dielectric surface (∼100 μm). The wave front is characterized by significant overshoot of both vertical and horizontal electric field vector components. Behind the wave front, the vertical field component is rapidly reduced. As the wave propagates along the dielectric surface, it also extends further away from the dielectric surface, up to ∼1 mm near the grounded electrode. The horizontal field component behind the wave front remains quite significant, to sustain the electron current toward the high voltage electrode. After the wave reaches the grounded electrode, the horizontal field component experiences a secondary rise in the quasi-dc discharge, where it sustains the current along the near-surface plasma sheet. The measurement results indicate presence of a cathode layer formed near the grounded electrode with significant cathode voltage fall, ≈3 kV, due to high current density in the discharge. The peak reduced electric field in the surface ionization wave is 85–95 Td, consistent with dc breakdown field estimated from the Paschen

  7. Surface modification of polyethylene by diffuse barrier discharge plasma

    Czech Academy of Sciences Publication Activity Database

    Novák, I.; Števiar, M.; Popelka, A.; Chodák, I.; Mosnáček, J.; Špírková, Milena; Janigová, I.; Kleinová, A.; Sedliačik, J.; Šlouf, Miroslav

    2013-01-01

    Roč. 53, č. 3 (2013), s. 516-523 ISSN 0032-3888 R&D Projects: GA AV ČR(CZ) IAAX08240901 Institutional research plan: CEZ:AV0Z40500505 Keywords : low-density polyethylene * plasma discharge * surface modification Subject RIV: JI - Composite Materials Impact factor: 1.441, year: 2013

  8. Manufacture, integration and demonstration of polymer solar cells in a lamp for the Lighting Africa initiative

    DEFF Research Database (Denmark)

    Krebs, Frederik C; Damgaard Nielsen, Torben; Fyenbo, Jan

    2010-01-01

    . The discrete components were white light LEDs, a blocking diode, a lithium ion battery, vias and button contacts in two adjacent corners. The completed lamp has outside dimensions of 22.5 × 30.5 cm, a weight of 50 g and a very flat outline. The battery and components were the thickest elements and measured ... mm. A hole with a ring was punched in one corner to enable mechanical fixation or tying. The lamp has two states. In the charging state it has a completely flat outline and will charge the battery when illuminated from either side while the front side illumination is preferable. When used as a lamp...... two adjacent corners are joined via button contacts whereby the device can stand on a horizontal surface and the circuit is closed such that the battery discharges through the LEDs that illuminate the surface in front of the lamp. Several different lamps were prepared using the same solar cell...

  9. Surface modification by EUV laser beam based on capillary discharge

    Czech Academy of Sciences Publication Activity Database

    Frolov, Oleksandr; Koláček, Karel; Schmidt, Jiří; Štraus, Jaroslav; Prukner, Václav; Shukurov, A.

    -, č. 58 (2011), s. 484-487 ISSN 2010-376X. [International Conference on Fusion and Plasma Physics. Bali, Indonésie, 26.10.2011-28.10.2011] R&D Projects: GA AV ČR KAN300100702; GA MŠk LA08024; GA MŠk(CZ) LC528 Institutional research plan: CEZ:AV0Z20430508 Keywords : soft x-ray * EUV * laser * radiation * source * capillary * discharge * plasma * ablation * surface modification Subject RIV: BL - Plasma and Gas Discharge Physics http://www.waset.org/journals/waset/v58/v58-99.pdf

  10. Properties of water surface discharge at different pulse repetition rates

    Czech Academy of Sciences Publication Activity Database

    Ruma, R.; Hosseini, S.H.R.; Yoshihara, K.; Akiyama, M.; Sakugawa, T.; Lukeš, Petr; Akiyama, H.

    2014-01-01

    Roč. 116, č. 12 (2014), s. 123304-123304 ISSN 0021-8979 Grant - others:Rada Programu interní podpory projektů mezinárodní spolupráce AV ČR(CZ) M100431203 Program:M Institutional support: RVO:61389021 Keywords : plasma in air * water surface discharge * pulse frequency * hydrogen peroxide * organic dye Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 2.183, year: 2014 http://dx.doi.org/ 10.1063/1.4896266

  11. Surface charging, discharging and chemical modification at a sliding contact

    International Nuclear Information System (INIS)

    Singh, S. V.; Kusano, Y.; Morgen, P.; Michelsen, P. K.

    2012-01-01

    Electrostatic charging, discharging, and consequent surface modification induced by sliding dissimilar surfaces have been studied. The surface-charge related phenomena were monitored by using a home-built capacitive, non-contact electrical probe, and the surface chemistry was studied by X-ray photoelectron spectroscopy (XPS). The experiments were performed on the disk surface of a ball-on-rotating-disk apparatus; using a glass disk and a Teflon (polytetrafluoroethylene) ball arrangement, and a polyester disks and a diamondlike carbon (DLC) coated steel ball arrangement. The capacitive probe is designed to perform highly resolved measurements, which is sensitive to relative change in charge density on the probed surface. For glass and Teflon arrangement, electrical measurements show that the ball track acquires non-uniform charging. Here not only the increase in charge density, but interestingly, increase in number of highly charged regions on the ball track was resolved. Threefold increase in the number of such highly charged regions per cycle was detected immediately before the gas breakdown-like incidences compared to that of other charge/discharge incidences at a fixed disk rotation speed. We are also able to comment on the behavior and the charge decay time in the ambient air-like condition, once the sliding contact is discontinued. XPS analysis showed a marginal deoxidation effect on the polyester disks due to the charging and discharging of the surfaces. Moreover, these XPS results clearly indicate that the wear and friction (sliding without charging) on the surface can be discarded from inducing such a deoxidation effect.

  12. Characteristics of meter-scale surface electrical discharge propagating along water surface at atmospheric pressure

    Czech Academy of Sciences Publication Activity Database

    Hoffer, Petr; Sugiyama, Y.; Hosseini, S.H.R.; Akiyama, H.; Lukeš, Petr; Akiyama, M.

    2016-01-01

    Roč. 49, č. 41 (2016), č. článku 415202. ISSN 0022-3727 Institutional support: RVO:61389021 Keywords : water surface * spectroscopy * high-speed photography * pulsed plasma discharge * Atmospheric-pressure plasmas * electric discharges * liquids * water Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 2.588, year: 2016 http://iopscience.iop.org/article/10.1088/0022-3727/49/41/415202

  13. Enhanced osteoblast response to electrical discharge machining surface.

    Science.gov (United States)

    Otsuka, Fukunaga; Kataoka, Yu; Miyazaki, Takashi

    2012-01-01

    The purpose of this study is to investigate the surface characteristics and biocompatibility of titanium (Ti) surfaces modified by wire electrical discharge machining (EDM). EDM surface characteristics were evaluated by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), thin-film X-ray diffractometry (XRD) and contact angle measurements. MC3T3-E1 cell morphology, attachment and proliferation, as well as analysis of osteoblastic gene expressions, on machined surfaces and EDM surfaces were also evaluated. EDM surfaces exhibited high super hydrophilicity, due to high surface energy. XPS and XRD revealed that a passive oxide layer with certain developing thickness onto. EDM surfaces promoted cell attachment, but restrained proliferation. Counted cell numbers increased significantly on the machined surfaces as compared to the EDM surfaces. Real-time PCR analyses showed significantly higher relative mRNA expression levels of osteoblastic genes (ALP, osteocalcin, Runx2, Osterix) in cells cultured on the EDM surfaces as compared to cells cultured on the machined surfaces.

  14. Application of dielectric surface barrier discharge for food storage

    Directory of Open Access Journals (Sweden)

    Yassine BELLEBNA

    2015-12-01

    Full Text Available Ozone (O3 is a powerful oxidizer and has much higher disinfection potential than chlorine and other disinfectants. Ozone finds its application mainly in water treatment and air purification Dielectric barrier discharge (DBD method has proved to be the best method to produce ozone. Dried air or oxygen is forced to pass through a 1-2 mm gap. The aim of this study was to show that disinfection system using ozone generated by dielectric barrier discharge (DBD is an effective alternative to be used in food industry and ensures a safe quality of air for optimum preservation of fruits and vegetables. The DBDs are specific kind of discharges because one (or sometimes both electrodes is covered by a dielectric material, thereby preventing the discharge to move towards electrical breakdown. A succession of microdischarges occurs rapidly; their "lifetime" is in the range of a few nanoseconds. One of their most important applications is the production of ozone for air treatment, used mainly in the area of food industry, for extending the storage life of foods. After the achievement of a surface DBD reactor of cylindrical shape and its electrical characterization, it was then used as an ozone generator for air disinfection. Obtained results have shown that this reactor used as an ozone generator is effective for disinfection of air by removing viruses, bacteria and pathogens, causing the slowdown of the ripening process of fruits and vegetables.

  15. Dielectric barrier discharge plasma treatment of cellulose nanofibre surfaces

    DEFF Research Database (Denmark)

    Kusano, Yukihiro; Madsen, Bo; Berglund, Linn

    2017-01-01

    Dielectric barrier discharge plasma treatment was applied to modify cellulose nanofibre (CNF) surfaces with and without ultrasonic irradiation. The plasma treatment improved the wetting by deionised water and glycerol, and increased the contents of oxygen, carbonyl group, and carboxyl group...... and amorphous phases. Ultrasonic irradiation also improved the uniformity of the treatment. Altogether, it is demonstrated that atmospheric pressure plasma treatment is a promising technique to modify the CNF surface before composite processing....... on the nanofibre surface. Ultrasonic irradiation further enhanced the wetting and oxidation of the nanofibre coating. Scanning electron microscopic observations showed skeleton-like features on the plasma-treated surface, indicating preferential etching of weaker domains, such as low-molecular weight domains...

  16. Modification of surface properties of LLDPE by water plasma discharge

    International Nuclear Information System (INIS)

    Chantara Thevy Ratnam; Hill, D.J.T.; Firas Rasoul; Whittaker, A.K.; Imelda Keen

    2007-01-01

    Linear low density polyethylene (LLDPE) surface was modified by water plasma treatment. The LLDPE surface was treated at 10 and 20 W discharge power at various exposure times. A laboratory scale Megatherm radio frequency (RF) plasma apparatus that operates at 27 MHz was used to generate the water plasmas. The changes in chemical structure of the LLDPE polymeric chain upon plasma treatment were characterized by FTIR and XPS techniques. The selectivity of trifluoroacetic anhydride (TFAA) toward hydroxyl groups is used to quantify the hydroxyl groups formed on the polymer surface upon plasma treatment. After exposition to the plasma discharge a decline in water contact angle were observed. FTIR and XPS measurements indicate an oxidation of degraded polymeric chains and creation of hydroxyl, carbonyl, ether, ester and carboxyl groups. Chemical derivatization with TFAA of water plasma treated polymer surfaces has shown that under the conditions employed, a very small (less than 5%) of the oxygen introduced by the water plasma treatment was present as hydroxyl group. (Author)

  17. Scaling laws and edge effects for polymer surface discharges

    Science.gov (United States)

    Balmain, K. G.

    1979-01-01

    Specimens of Mylar sheet were exposed to a 20 kV electron beam. The resulting surface discharge arcs were photographed and the discharge current into a metal backing plate measured as a function of time. The area of the Mylar sheet was defined by a round aperture in a close-fitting metal mask, and the current pulse characteristics were plotted against area on log-log paper. The plots appear as straight lines (due to power-law behavior) with slopes of 0.50 for the peak current, 1.00 for the charge released, 1.49 for the energy and 0.55 for the pulse duration. Evidence is presented for the occurrence of banded charge distributions near grounded edges, on both Teflon and Mylar.

  18. Atmospheric pressure dielectric barrier discharges for sterilization and surface treatment

    Energy Technology Data Exchange (ETDEWEB)

    Chin, O. H.; Lai, C. K.; Choo, C. Y.; Wong, C. S.; Nor, R. M. [Plasma Technology Research Centre, Physics Department, Faculty of Science, University of Malaya, 50603 Kuala Lumpur (Malaysia); Thong, K. L. [Microbiology Division, Institute of Biological Sciences, Faculty of Science, University of Malaya, 50603 Kuala Lumpur (Malaysia)

    2015-04-24

    Atmospheric pressure non-thermal dielectric barrier discharges can be generated in different configurations for different applications. For sterilization, a parallel-plate electrode configuration with glass dielectric that discharges in air was used. Gram-negative bacteria (Escherichia coli and Salmonella enteritidis) and Gram-positive bacteria (Bacillus cereus) were successfully inactivated using sinusoidal high voltage of ∼15 kVp-p at 8.5 kHz. In the surface treatment, a hemisphere and disc electrode arrangement that allowed a plasma jet to be extruded under controlled nitrogen gas flow (at 9.2 kHz, 20 kVp-p) was applied to enhance the wettability of PET (Mylar) film.

  19. Multitechnique characterization of CPTi surfaces after electro discharge machining (EDM).

    Science.gov (United States)

    Zinelis, Spiros; Al Jabbari, Youssef S; Thomas, Andrew; Silikas, Nick; Eliades, George

    2014-01-01

    The aim of this study was to comparatively assess the surface roughness parameters, the hardness, and the elemental and molecular alterations induced on CPTi surfaces after conventional finishing and finishing with electro discharge machining (EDM). A completed cast model of an arch that received four implants was used for the preparation of two grade II CPTi castings. One framework was conventionally finished (CF), whereas the other was subjected to EDM finishing. The surface morphology was imaged employing SEM. 3D surface parameters (S a, S q, S z, S ds, S dr, and S ci) were calculated by optical profilometry. The elemental composition of the treated surfaces was determined by energy dispersive X-ray analysis, whereas the elemental and chemical states of the outmost layer were investigated by X-ray photoelectron spectrometry. Surface hardness was also tested with a Knoop indenter. The results of surface roughness parameters, elemental analysis, and hardness were compared using unpaired t test (a = 0.05). The EDM group demonstrated a rougher surface, with a significant uptake of C and Cu. The CF surface mainly consisted of TiO2. On EDM surface though, Ti was probed in different chemicals states (TiO2, Ti2O3, TiC and metallic Ti) and Cu was traced as Cu2O and CuO. Hardness after EDM was almost ten times higher than CF. EDM significantly affected surface roughness, chemical state, and hardness properties of grade II CPTi castings in comparison with CF. The morphological and elemental alterations of EDM-treated CPTi surfaces may strongly contribute to the reduced corrosion resistance documented for this procedure. The degradation of electrochemical properties may have further biological implications through ionic release in the oral environment.

  20. Studies of nanosecond pulse surface ionization wave discharges over solid and liquid dielectric surfaces

    International Nuclear Information System (INIS)

    Petrishchev, Vitaly; Leonov, Sergey; Adamovich, Igor V

    2014-01-01

    Surface ionization wave discharges generated by high-voltage nanosecond pulses, propagating over a planar quartz surface and over liquid surfaces (distilled water and 1-butanol) have been studied in a rectangular cross section test cell. The discharge was initiated using a custom-made, alternating polarity, high-voltage nanosecond pulse plasma generator, operated at a pulse repetition rate of 100–500 Hz, with a pulse peak voltage and current of 10–15 kV and 7–20 A, respectively, a pulse FWHM of ∼100 ns, and a coupled pulse energy of 2–9 mJ/pulse. Wave speed was measured using a capacitive probe. ICCD camera images demonstrated that the ionization wave propagated predominantly over the quartz wall or over the liquid surface adjacent to the grounded waveguide placed along the bottom wall of the test cell. Under all experimental conditions tested, the surface plasma ‘sheet’ was diffuse and fairly uniform, both for positive and negative polarities. The parameters of ionization wave discharge propagating over distilled water and 1-butanol surfaces were close to those of the discharge over a quartz wall. No perturbation of the liquid surface by the discharge was detected. In most cases, the positive polarity surface ionization wave propagated at a higher speed and over a longer distance compared to the negative polarity wave. For all three sets of experiments (surface ionization wave discharge over quartz, water and 1-butanol), wave speed and travel distance decreased with pressure. Diffuse, highly reproducible surface ionization wave discharge was also observed over the liquid butanol–saturated butanol vapor interface, as well as over the distilled water–saturated water vapor interface, without buffer gas flow. No significant difference was detected between surface ionization discharges sustained using single-polarity (positive or negative), or alternating polarity high-voltage pulses. Plasma emission images yielded preliminary evidence of charge

  1. Direct plasma NOx reduction using single surface dielectric barrier discharge

    DEFF Research Database (Denmark)

    Kroushawi, Feisal; Stamate, Eugen

    2014-01-01

    NOx reduction using direct atmospheric barrier discharge in air-NO mixture at different voltages and flow rates is inversigated. Reduction rate of 80% is achieved at 3.18 W/cm2 power density and gas mixture of 20 slm air and 0.006 slm NO. The ozone for NO reduction is produced by a honeycomb...... structured DBD with a total surface of 12.56 cm2. The reduction process is investigated by FTIR spectroscopy, chemiluminsecence, mass spectrometry and optical emission spectroscopy....

  2. Submittal of SWMU Assessment Report for Building 9960 Surface Discharge

    Energy Technology Data Exchange (ETDEWEB)

    Dotson, Patrick Wells [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-03-01

    Sandia National Laboratories is a multi-purpose engineering and science laboratory owned by the U.S. Department of Energy (DOE)/National Nuclear Security Administration and managed and operated by Sandia Corporation (Sandia), a wholly-owned subsidiary of Lockheed Martin Corporation. This Solid Waste Management Unit (SWMU) Assessment Report (SAR) for the Sandia National Laboratories, New Mexico (SNL/NM), Coyote Test Field, Building 9960 Surface Discharge, has been prepared in accordance with Section V of the Compliance Order on Consent (the Consent Order) between the New Mexico Environment Department (NMED), DOE, and Sandia (NMED April 2004). The DOE and Sandia formally notified the NMED of this newly identified or suspected SWMU or Area of Concern (AOC) by letter dated December 9, 2014. This SAR is being submitted in accordance with the NMED Hazardous Waste Bureau (HWB) letter dated February 16, 2015 letter (Kieling February 2015). This SAR presents the available information for the Building 9960 Surface Discharge, including location, designation of type and function, a general description, the operational dates, waste characteristics, and a summary of existing analytical wastewater and soil data

  3. [Study on Square Super-Lattice Pattern with Surface Discharge in Dielectric Barrier Discharge by Optical Emission Spectra].

    Science.gov (United States)

    Niu, Xue-jiao; Dong, Li-fang; Liu, Ying; Wang, Qian; Feng, Jian-yu

    2016-02-01

    Square super-lattice pattern with surface discharge consisting of central spots and dim spots is firstly observed in the mixture of argon and air by using a dielectric barrier discharge device with water electrodes. By observing the image, it is found that the central spot is located at the centriod of its surrounding four dim spots. The short-exposure image recorded by a high speed video camera shows that the dim spot results from the surface discharges (SDs). The brightness of the central spot and is quite different from that of the dim spot, which indicates that the plasma states of the central spot and the dim spot may be differentiated. The optical emission spectrum method is used to further study the several plasma parameters of the central spot and the dim spot in different argon content. The emission spectra of the N₂ second positive band (C³IIu --> B³ IIg) are measured, from which the molecule vibration temperatures of the central spot and the dim spot are calculated respectively. The broadening of spectral line 696.57 nm (2P₂-->1S₅) is used to study the electron densities of the central spot and the dim spot. It is found that the molecule vibration temperature and electron density of the dim spot are higher than those of the central spot in the same argon content The molecule vibration temperature and electron density of the central spot and the dim spot increase with the argon content increasing from 90% to 99.9%. The surface discharge induced by the volume discharge (VD) has the determinative effect on the formation of the dim spot The experimental results above play an important role in studying the formation mechanism of surface discharg&of square super-lattice pattern with surface discharge. In addition, the studies exert an influence on the application of surface discharge and volume discharge in different fields.

  4. Experimental investigation of surface roughness in electrical discharge turning process

    Science.gov (United States)

    Gohil, Vikas; Puri, Y. M.

    2016-10-01

    In the present study the effects of machining parameters on the average surface roughness (Ra) in electrical discharge turning (EDT) is investigated. EDT is a new machining process in which a rotary spindle is added to a conventional die-sinking EDM machine in order to produce cylindrical components. In this method a new process parameter (spindle rotation) along with pulse on time and current is introduced to study its effect on Ra. This has been done by means of full factorial design (21 × 32) of experiments. A mathematical model has been developed for Ra by regression analysis and factor effects were analyzed using analysis of variance (ANOVA). Signal-to-noise ratio analysis is used to find the optimal condition.

  5. Diffuse coplanar surface barrier discharge -- basic properties and its application in surface treatment of nonwovens

    Science.gov (United States)

    Kovacik, Dusan; Rahel, Jozef; Kubincova, Jana; Zahoranova, Anna; Cernak, Mirko

    2009-10-01

    In recent years, low temperature atmospheric pressure plasma surface treatments have become a hot topic because of the potential of fast and efficient in-line processing fabrication without expensive vacuum equipment. A major problem of atmospheric pressure treatment in air is insufficient treatment uniformity because, particularly at the higher plasma power densities, the air plasma has the tendency of filamentation and transition into an arc discharge. Diffuse coplanar surface barrier discharge (DCSBD) plasma source has been developed to overcome these problems. This type of discharge enables to generate macroscopically homogeneous thin (˜ 0.3 mm) plasma layer with power density of some 100 W/cm^3 practically in any gas without admixture of He. It was found that the ambient air plasma of DCSBD is capable to make lightweight polypropylene nonwoven fabrics permanently hydrophilic, without any pinholing and with low power consumption of some 1 kWh/kg.

  6. High efficiency fluorescent excimer lamps: An alternative to mercury based UVC lamps

    Energy Technology Data Exchange (ETDEWEB)

    Masoud, N. M. [UV Solutions Inc, Newark, New Jersey 07103 (United States); Physics and Chemistry Department, Milwaukee School of Engineering, Milwaukee, Wisconsin 53202 (United States); Murnick, D. E. [UV Solutions Inc, Newark, New Jersey 07103 (United States); Department of Physics, Rutgers University, Newark, New Jersey 07102 (United States)

    2013-12-15

    A high efficiency xenon excimer lamp radiating at 172 nm, with an internal phosphor coating shifting to UVC has been demonstrated, showing the feasibility of a cost effective alternative to UVC mercury lamps. Fluorescent lamps so designed can be fabricated in various geometries with high efficiency. Unlike other xenon excimer lamps based on dielectric barrier discharges this new system is highly compatible with existing and proposed phosphors as it operates in an inert gas environment at modest temperature and is subject only to 172 nm primary radiation. Using a lamp coated with a UVC phosphor we have demonstrated the feasibility of germicidal and curing lamps with 40% energy conversion efficiency and high power density. These lamps are rapidly switchable, have long projected lifetimes and are compatible with dimmers.

  7. LED lamp

    Science.gov (United States)

    Galvez, Miguel; Grossman, Kenneth; Betts, David

    2013-11-12

    There is herein described a lamp for providing white light comprising a plurality of light sources positioned on a substrate. Each of said light sources comprises a blue light emitting diode (LED) and a dome that substantially covers said LED. A first portion of said blue light from said LEDs is transmitted through said domes and a second portion of said blue light is converted into a red light by a first phosphor contained in said domes. A cover is disposed over all of said light sources that transmits at least a portion of said red and blue light emitted by said light sources. The cover contains a second phosphor that emits a yellow light in response to said blue light. The red, blue and yellow light combining to form the white light and the white light having a color rendering index (CRI) of at least about 80.

  8. Study and implementation of a non-resonant inverter as electronic ballast for discharge lamps; Estudio e implementacion de un inversor no resonante como balastro electronico para lamparas de descarga

    Energy Technology Data Exchange (ETDEWEB)

    Flores Garcia, Efren

    2003-02-15

    Implementation of an electronic ballast with integrated ignition circuit that feeds a high density discharge lamp and that limits the current through it without closing the control loop under the technique of current square waves to eliminate the acoustic resonances characteristic of these high pressure lamps. In chapter 1 the basic concepts are presented of high intensity discharge lamps, showing their classification and describing their operation. In addition, the phenomenon of acoustic resonances is mentioned, emphasizing the square wave shape use for its elimination and presenting the state-of-the-art around the use of this technique for the elimination of acoustic resonances. In chapter 2 the different techniques are presented to stabilize the current in a discharge lamp. In addition, a topology of converter DC-DC is proposed that stabilizes the discharge in presenting a resistance in series with the lamp and it does not use a control loop for this, presenting its analysis and raising the necessary characteristics for its correct operation. In chapter 3 the analysis of each one of the stages that conforms the ballast is presented, simultaneously two igniter topologies are presented, that on the basis of an analysis one of them is selected for its implementation. In addition, the simulation results of the ballast performed in the PSpice simulator are presented. In chapter 4 is shown the form in which the implementation of the ballast was carried out, presenting the experimental results and verifying that the ballast operates according to the originally proposed specifications. Finally, in chapter 5 the conclusions of the work and the recommendations for future works are presented. [Spanish] Implementacion de un balastro electronico con circuito de encendido integrado que alimenta a una lampara de alta densidad de descarga y que limita la corriente a traves de ella sin cerrar el lazo de control bajo la tecnica de ondas cuadradas de corriente para eliminar las

  9. Surface modification with a remote atmospheric pressure plasma: dc glow discharge and surface streamer regime

    International Nuclear Information System (INIS)

    Temmerman, Eef; Akishev, Yuri; Trushkin, Nikolay; Leys, Christophe; Verschuren, Jo

    2005-01-01

    A remote atmospheric pressure discharge working with ambient air is used for the near room temperature treatment of polymer foils and textiles of varying thickness. The envisaged plasma effect is an increase in the surface energy of the treated material, leading, e.g., to a better wettability or adhesion. Changes in wettability are examined by measuring the contact angle or the liquid absorptive capacity. Two regimes of the remote atmospheric pressure discharge are investigated: the glow regime and the streamer regime. These regimes differ mainly in power density and in the details of the electrode design. The results show that this kind of discharge makes up a convenient non-thermal plasma source to be integrated into a treatment installation working at atmospheric pressure

  10. Systematic investigation of the barrier discharge operation in helium, nitrogen, and mixtures: discharge development, formation and decay of surface charges

    Science.gov (United States)

    Tschiersch, R.; Bogaczyk, M.; Wagner, H.-E.

    2014-09-01

    As a logical extension to previous investigations of the barrier discharge (BD) in helium and nitrogen, the present work reports on the operation in any mixtures of both pure gases. Using a well-established plane-parallel discharge cell configuration allows to study the influence of the He/N2 mixing ratio on the formation of different discharge modes. Their characterization was made by measuring the discharge emission development together with the formation and decay of surface charges on a bismuth silicon oxide (Bi12SiO20, BSO) crystal. This was realized by the simultaneous application of the spatio-temporally resolved optical emission spectroscopy, and the electro-optic Pockels effect in combination with a CCD high speed camera. The existence diagram for diffuse and filamentary BDs was determined by varying the amplitude and shape of the applied voltage. Over the entire range of the He/N2 ratio, the diffuse mode can be operated at moderate voltage amplitudes whereas filamentation occurs at significant overvoltage and is favoured by a high voltage slew rate. Irrespective of the discharge mode, the overall charge transfer during a discharge breakdown is found to be in excellent agreement with the amount of accumulated surface charges. An exponential decay of the surface charge deposited on the BSO crystal is induced by LED illumination beyond a typical discharge cycle. During the decay process, a broadening of the radial profiles of positive as well as negative surface charge spots originating from previous microdischarges is observed. The investigations contribute to a better understanding of the charge accumulation at a dielectric.

  11. UV lamp for photoelectron spectroscopy

    International Nuclear Information System (INIS)

    Cardoso, M.J.B.; Landers, R.; Sundaram, V.S.

    1983-01-01

    An UV lamp and a differential pumping system which enables to couple the lamp to an ultra-high vacuum chamber (10 -9 torr) without using windows, are described. The differential between the pressure inside the discharge chamber and the one in de UHV region, which is of 10 8 -10 9 , is achieved with two pumping states separated by pyrex capillaries having an internal diameter of 0.6 mm. In the first stage, a mechanical pump (10 -3 torr) is used; in the second stage, a diffusor pump with a cryogenic trap (N 2 liq - 10 -7 torr) is employed. The lamp produces, when used with high purity He, narrow lines almost clear at 21.2 eV and 40.8 eV, depending on the discharge chamber pressure, thus eliminating the need of a monochromator. As a high voltage source (3 KV), a commercial unit with a good current control was used, ensuring UV beam stability - an essential characteristic for this lamp if it is employed for photoelectron excitation of crystalline samples. (C.L.B.) [pt

  12. Surface oxide formation during corona discharge treatment of AA 1050 aluminium surfaces

    DEFF Research Database (Denmark)

    Minzari, Daniel; Møller, Per; Kingshott, Peter

    2008-01-01

    process modifies aluminium AA 1050 surface, the oxide growth and resulting corrosion properties. The corona treatment is carried out in atmospheric air. Treated surfaces are characterized using XPS, SEM/EDS, and FIB-FESEM and results suggest that an oxide layer is grown, consisting of mixture of oxide...... and hydroxide. The thickness of the oxide layer extends to 150–300 nm after prolonged treatment. Potentiodynamic polarization experiments show that the corona treatment reduces anodic reactivity of the surface significantly and a moderate reduction of the cathodic reactivity.......Atmospheric plasmas have traditionally been used as a non-chemical etching process for polymers, but the characteristics of these plasmas could very well be exploited for metals for purposes more than surface cleaning that is presently employed. This paper focuses on how the corona discharge...

  13. Cleaning of niobium surface by plasma of diffuse discharge at atmospheric pressure

    Science.gov (United States)

    Tarasenko, V. F.; Erofeev, M. V.; Shulepov, M. A.; Ripenko, V. S.

    2017-07-01

    Elements composition of niobium surface before and after plasma treatment by runaway electron preionized diffuse discharge was investigated in atmospheric pressure nitrogen flow by means of an Auger electron spectroscopy. Surface characterizations obtained from Auger spectra show that plasma treatment by diffuse discharge after exposure of 120000 pulses provides ultrafine surface cleaning from carbon contamination. Moreover, the surface free energy of the treated specimens increased up to 3 times, that improve its adhesion property.

  14. Experimental study of femtosecond laser-stimulated electrical discharges in small gaps and surface modifications

    International Nuclear Information System (INIS)

    Chen, J.; Farson, D. F.; Rokhlin, S. I.

    2009-01-01

    Femtosecond laser-stimulated discharges in nanoscale and microscale gaps between etched nanoprobe tip cathodes and gold film anodes with applied dc potential were experimentally studied to define parameter ranges for their controlled formation and resulting surface modifications. For appropriate values of gap length, applied potential, and laser irradiance, breakdown discharges could be reliably stimulated by femtosecond laser pulses and the mean breakdown field was approximately an order of magnitude smaller than for breakdown without laser stimulation. For 500 nm gaps, discharges were observed for applied potentials as small as 20 V and controllable gold film surface melting was detected for applied potential of 27.5 V. Minor cathode tip ablation could be observed for femtosecond laser pulses that reliably stimulated discharges, suggesting that cathode material played an important role in stimulation of breakdown discharges in nanoscale gaps. Surface melting produced features as small as 60 nm on gold film when discharge current was limited by 1 MΩ series resistor

  15. 10 CFR 431.322 - Definitions concerning metal halide lamp ballasts and fixtures.

    Science.gov (United States)

    2010-01-01

    ... lamp, and the capacitor when the capacitor is provided, shall constitute a nominal system in accordance... designed to be operated with a metal halide lamp and a ballast for a metal halide lamp. Probe-start metal... discharge and then power to sustain the discharge through the glow-to-arc transition. Test Procedures ...

  16. The high pressure xenon lamp as a source of radiation

    International Nuclear Information System (INIS)

    Heerdt, J.A. ter.

    1979-01-01

    An account is given of an investigation into the radiation properties of a commercially available high pressure xenon lamp (type XBO 900 W) in the spectral range 0.3 to 3 μm. The purpose of the study was to find out whether such a lamp can serve as a (secondary) standard of radiation in spectroscopic and radiometric measurements. The main advantades of the xenon lamp over other secondary standards such as the tungsten strip lamp and the anode of a carbon arc lamp are the high temperature of its discharge and the resulting strong radiation over a broad spectral range. (Auth.)

  17. The effect of the operation modes of a gas discharge low-pressure amalgam lamp on the intensity of generation of 185 nm UV vacuum radiation

    Energy Technology Data Exchange (ETDEWEB)

    Vasilyak, L. M., E-mail: vasilyak@ihed.ras.ru [Russian Academy of Sciences, Joint Institute of High Temperatures (Russian Federation); Drozdov, L. A., E-mail: lit@npo.lit.ru; Kostyuchenko, S. V.; Sokolov, D. V. [ZAO LIT (Russian Federation); Kudryavtsev, N. N.; Sobur, D. A., E-mail: soburda@gmail.com [Moscow Institute for Physics and Technology (Russian Federation)

    2011-12-15

    The effect of the discharge current, mercury vapor pressure, and the inert gas pressure on the intensity and efficiency of the 185 nm line generation are considered. The spectra of the UV radiation (vacuum ultraviolet) transmission by protective coatings from the oxides of rare earth metals and aluminum are investigated.

  18. High Conductivity Water Treatment Using Water Surface Discharge with Nonmetallic Electrodes

    International Nuclear Information System (INIS)

    Wang Xiaoping; Zhang Xingwang; Lei Lecheng

    2013-01-01

    Although electrohydraulic discharge is effective for wastewater treatment, its application is restricted by water conductivity and limited to the treatment of low conductivity water. For high conductivity water treatment, water-surface discharge is the preferred choice. However, the metallic electrodes are easily corroded because of the high temperature and strong oxidative environment caused by gas phase discharge and the electrochemical reaction in water. As a result, the efficiency of the water treatment might be affected and the service life of the reactor might be shortened. In order to avoid the corrosion problem, nonmetallic electrode water-surface discharge is introduced into high conductivity water treatment in the present study. Carbon-felt and water were used as the high voltage electrode and ground electrode, respectively. A comparison of the electrical and chemical characteristics showed that nonmetallic electrode discharge maintained the discharge characteristics and enhanced the energy efficiency, and furthermore, the corrosion of metal electrodes was avoided.

  19. Wood's lamp examination

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/003386.htm Wood lamp examination To use the sharing features on this page, please enable JavaScript. A Wood lamp examination is a test that uses ultraviolet ( ...

  20. Wood's lamp illumination (image)

    Science.gov (United States)

    A Wood's lamp emits ultraviolet light and can be a diagnostic aid in determining if someone has a fungal ... is an infection on the area where the Wood's lamp is illuminating, the area will fluoresce. Normally ...

  1. Technical and economic feasibility of the use of discharge lamps in replacement of filament for induction of photoperiod in chrysanthemum seedlings production; Viabilidade tecnico-economica do uso de lampadas de descarga em substituicao as de filamento para inducao de fotoperiodo na producao de mudas de crisantemos

    Energy Technology Data Exchange (ETDEWEB)

    Rossi, Luiz A.; David, Eduardo [Universidade Estadual de Campinas (FEAGRI/UNICAMP), SP (Brazil). Fac. de Engenharia Agricola], E-mail: rossi@feagri.unicamp.br; Pagliardi, Odail [Faculdade Municipal Prof. Franco Montoro (FMPFM), Mogi Guacu, SP (Brazil); Sarubbi, Juliana [Universidade Federal de Santa Maria (CESNORS/UFSM), Palmeira das Missoes, RS (Brazil). Centro de Educacao Superior Norte-RS

    2010-07-01

    Due to its physiological characteristics, the seedlings of chrysanthemums require supplemental light to prevent bud formation, that is done at night. This article examines the technical and economic valuation to replace the current technology of artificial lighting used by producers (incandescent bulbs) for the purpose of inducing photoperiod in a protected environment for cutting-discharge lamps, with the goal of reducing the consumption electricity used in the process. The analysis showed that the integrated compact fluorescent yellow lamp 23W is the technically and economically feasible for such replacement. (author)

  2. Baseline studies and evaluation of effects of surface discharge of deep-sea mining - INDEX area

    Digital Repository Service at National Institute of Oceanography (India)

    DeSousa, S.N.; Sardessai, S.

    . An evaluation of possible effects of surface discharge of mining fines - a slurry consisting of fine nodule fragments, bottom water and sediments - suggests that the discharge, with an expected solid content of 50 g/l, will induce increased primary production...

  3. Low-temperature hydrogenation of diamond nanoparticles using diffuse coplanar surface barrier discharge at atmospheric pressure

    Czech Academy of Sciences Publication Activity Database

    Kromka, Alexander; Čech, J.; Kozak, Halyna; Artemenko, Anna; Ižák, Tibor; Čermák, Jan; Rezek, Bohuslav; Černák, M.

    2015-01-01

    Roč. 252, č. 11 (2015), s. 2602-2607 ISSN 0370-1972 R&D Projects: GA ČR(CZ) GBP108/12/G108 Institutional support: RVO:68378271 Keywords : atmospheric plasma * diamond nanoparticles * diffuse coplanar surface barrier discharge * FTIR * XPS Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 1.522, year: 2015

  4. Analysis of the performance of domestic lighting lamps

    International Nuclear Information System (INIS)

    Aman, M.M.; Jasmon, G.B.; Mokhlis, H.; Bakar, A.H.A.

    2013-01-01

    The power crisis problem is getting worse in the developing countries. Measures are being taken to overcome the power shortage problem by efficiently utilizing the available power. Replacement of high-power consumption lamps with energy efficient lamps is also among these steps. This paper presents a detailed comparative analysis between domestic lighting lamps (DLLs) use for producing artificial light. DLLs include incandescent lamp (IL), fluorescent lamp (FL) and compact fluorescent lamp (CFL). Light emitting diodes (LED) based lamp technology is relatively new in comparison with conventional incandescent and discharge lamps. However, the present study will also cover the LED lamps. Power quality based experiments have been conducted on DLLs in Power System Laboratory and power consumption based calculations are carried out using the lighting design software DIALux. The result shows that with the current technology, the use of FL and LED lamp is beneficial for utility as well as for consumer. However, with the current pace in the development of LED technology, it is possible LED lamps will lead the lighting market in the near future. The paper has also presented the uncertainties that exist in lighting market and proposed the guidelines that will help in making future energy policy. - Highlights: ► Performances of domestic lighting lamps are compared. ► Power quality and power consumption based case study results are presented. ► For future energy policies, recommendations are also given.

  5. High temperature getter for compact HID lamps

    Energy Technology Data Exchange (ETDEWEB)

    Maagt, B J de [Central Development Lighting, Philips Lighting B.V., PO Box 80020, 5600JM, Eindhoven (Netherlands); Corazza, A [SAES Getters S.p.A., Viale Italia 77, 20020 Lainate, Milan (Italy)

    2005-09-07

    In high intensity discharge (HID) lamps getters are generally used to remove gaseous impurities that otherwise may have negative effects on the lamp characteristics. Hydrogen, in particular, is a dangerous impurity because it can induce ignition problems and, in lamps with a quartz burner, it can diffuse from the outer bulb into the arc tube and cause early corrosion of the quartz. Recently a new getter, suitable to work in compact HID lamps operated at high temperatures, has been developed: this getter is an appropriate solution to sorb hydrogen at high working temperatures in lamps where the use of a conventional getter is inadequate because of its small capacity for gettering hydrogen, its relatively high hydrogen equilibrium pressure and problems associated with the evaporation of getter and container material. The newly developed getter, named high temperature getter (HTG), is based on a special alloy enclosed in a niobium container. The new alloy is very effective in sorbing hydrogen in the temperature region of 500-900 deg. C. It has been proved that by introducing the HTG the processing of high-wattage compact HID lamps can be simplified and a better lamp performance can be obtained.

  6. Novel Electronic Ballast for Automotive HID Lamps

    Science.gov (United States)

    Urakabe, Takahiro; Kinoshita, Hidehiko; Kawasaka, Taihei

    Simplifying the composition of the automotive HID lamp electronic ballast has been considered. This paper describes the novel electronic ballast that is composed of a DC/DC converter, a capacitor connected to a lamp in series, a switch (S3) connected to the capacitor in parallel, a switch (S2) placed between the output terminals of the DC/DC converter and also connected in parallel to the lamp and the capacitor in series, and an igniter. All MOSFETs (S1 in the DC/DC converter, S2 and S3) in the ballast are operated on the common voltage position (GND) of the circuit. The DC/DC converter is operated intermittently and the operation of S2 synchronizes with the operation of it to supply the lamp with an alternate square wave voltage. Operating an automotive HID lamp succeeded using the novel ballast and by setting some issues below. 1) The occurrence of the power loss when S2 is turned on. 2) The occurrence of extinction of gas discharge. This paper describes how the loss can be decreased if a part of the energy stored in the output capacitor of the DC/DC conveter is used to operate the lamp before S2 is turned on. It also describes how an inductor and a capacitor were added to the proposed electronic ballast to raise the lamp voltage in order to prevent the current from disappearing.

  7. Pathogenic and nonpathogenic Acanthamoeba spp. in thermally polluted discharges and surface waters

    Energy Technology Data Exchange (ETDEWEB)

    de Jonckheere, J.F.

    1981-02-01

    During spring and autumn, the total number of amoebae and the number of acanthamoeba species able to grow at 37 degrees C were determined in six thermally polluted factory discharges and the surrounding surface waters. The isolated Acanthamoeba strains were studied for growth in axenic medium, cytopathic effect in Vito cell cultures, and virulence in mice. Although more amoebae were isolated in autumn, the number of Acanthamoeba species was lower than in spring, when the percent of pathogenic strains among the isolates was highest. Higher concentrations of amoebae were found in warm discharges, and more virulent strains occurred in thermal discharges than in surface waters.

  8. Pathogenic and nonpathogenic Acanthamoeba spp. in thermally polluted discharges and surface waters

    International Nuclear Information System (INIS)

    de Jonckheere, J.F.

    1981-01-01

    During spring and autumn, the total number of amoebae and the number of acanthamoeba species able to grow at 37 degrees C were determined in six thermally polluted factory discharges and the surrounding surface waters. The isolated Acanthamoeba strains were studied for growth in axenic medium, cytopathic effect in Vito cell cultures, and virulence in mice. Although more amoebae were isolated in autumn, the number of Acanthamoeba species was lower than in spring, when the percent of pathogenic strains among the isolates was highest. Higher concentrations of amoebae were found in warm discharges, and more virulent strains occurred in thermal discharges than in surface waters

  9. Diode-laser-illuminated automotive lamp systems

    Science.gov (United States)

    Marinelli, Michael A.; Remillard, Jeffrey T.

    1998-05-01

    We have utilized the high brightness of state-of-the-art diode laser sources, and a variety of emerging optical technologies to develop a new class of thin, uniquely styled automotive brake and signal lamps. Using optics based on thin (5 mm) plastic sheets, these lamps provide appearance and functional advantages not attainable with traditional automotive lighting systems. The light is coupled into the sheets using a 1 mm diameter glass fiber, and manipulated using refraction and reflection from edges, surfaces, and shaped cut-outs. Light can be extracted with an efficiency of approximately 50% and formed into a luminance distribution that meets the Society of Automotive Engineers (SAE) photometric requirements. Prototype lamps using these optics have been constructed and are less than one inch in thickness. Thin lamps reduce sheet metal costs, complexity, material usage, weight, and allow for increased trunk volume. In addition, these optics enhance lamp design flexibility. When the lamps are not energized, they can appear body colored, and when lighted, the brightness distribution across the lamp can be uniform or structured. A diode laser based brake lamp consumes seven times less electrical power than one using an incandescent source and has instant on capability. Also, diode lasers have the potential to be 10-year/150,000 mile light sources.

  10. Surface modification of polyethylene/graphene composite using corona discharge

    Science.gov (United States)

    Popelka, Anton; Noorunnisa Khanam, P.; AlMaadeed, Mariam Ali

    2018-03-01

    Polyethylene/graphene composites are suitable for electromagnetic interference shielding applications and are often fabricated as sandwich structures. However, the hydrophobic character of these composites can lead to delamination. Corona treatment was used to enhance the surface hydrophilicity of composites prepared from linear low-density polyethylene (LLDPE) and graphene nanoplatelets (GNPs) with different content (2, 4, 6, and 8 wt.%). This enhancement of wettability also led to good adhesion properties. The presence of GNPs in LLDPE had a positive effect on the surface properties after corona treatment. The surface free energy of the LLDPE/GNP composites increased by almost 64.6% for 2 wt.% of GNPs in the LLDPE/GNP composite, while the surface free energy of neat LLDPE increased by only 38.1%. The best improvement in adhesion properties after corona treatment was observed for 2 wt.% of GNPs in the LLDPE/GNP composite, while peel resistance increased by 137.9%. Various analytical techniques and methods proved that the changes in the surface morphology and chemical composition of the LLDPE/GNP composite after this treatment resulted in an improvement of adhesion.

  11. Surface modification by preparation of buffer zone in glow-discharge plasma

    International Nuclear Information System (INIS)

    Cho, D.L.

    1986-01-01

    Reactive species, energetic particles, and uv radiation in the plasma created by a glow discharge strongly interact with solid surfaces under the influence of the plasma. As a result of the strong interaction, various physical and chemical reactions, unique and advantageous for the surface modification of solid materials, occur on the solid surfaces. The surface modification is carried out through formation of a thin buffering layer on the solid surface. The preparation of a buffer zone on solid surfaces for surface modification is described. Two kinds of a buffer zone are prepared by plasma polymerization, or simultaneous sputter deposition of electrode material with plasma polymerization: a transitional buffer zone and a graded buffer zone. Important factors for preparation of the buffer zone (pre-conditioning of a substrate surface, thin-film deposition, post-treatment of the film, magnetron discharge, energy input, geometry of a substrate and a plasma) are discussed

  12. Surface charging, discharging and chemical modification at a sliding contact

    DEFF Research Database (Denmark)

    Singh, Shailendra Vikram; Kusano, Yukihiro; Morgen, Per

    2012-01-01

    -ray photoelectron spectroscopy (XPS). The experiments were performed on the disk surface of a ball-on-rotating-disk apparatus; using a glass disk and a Teflon (polytetrafluoroethylene) ball arrangement, and a polyester disks and a diamondlike carbon (DLC) coated steel ball arrangement. The capacitive probe...... is designed to perform highly resolved measurements, which is sensitive to relative change in charge density on the probed surface. For glass and Teflon arrangement, electrical measurements show that the ball track acquires non-uniform charging. Here not only the increase in charge density, but interestingly...... indicate that the wear and friction (sliding without charging) on the surface can be discarded from inducing such a deoxidation effect. © 2012 American Institute of Physics...

  13. The development of dielectric barrier discharges in gas gaps and on surfaces

    International Nuclear Information System (INIS)

    Gibalov, Valentin I.; Pietsch, Gerhard J.

    2000-01-01

    Dielectric barrier discharges (DBDs) occur in configurations which are characterized by a dielectric layer between conducting electrodes. Two basic configurations can be distinguished: a volume discharge (VD) arrangement with a gas gap; and a surface discharge (SD) arrangement with surface electrode(s) on a dielectric layer and an extensive counter electrode on its reverse side. At atmospheric pressure the DBD consists of numerous microdischarges (VD) and discharge steps (SD), respectively, their number being proportional to the amplitude of the voltage. These events have a short duration in the range of some 10 ns transferring a certain amount of charge within the discharge region. The total transferred charge determines the current and hence the volt-ampere characteristic of each arrangement. The microdischarges (discharge steps) have a complicated spatial structure. The discharge patterns on the dielectric surface depend on the polarity and amplitude of the applied voltage as well as on the specific capacity of the dielectric. Experimental findings on DBDs in air and oxygen are presented and discussed. On the basis of a self-consistent two-dimensional modelling the temporal and spatial development of a microdischarge and discharge step are investigated numerically. The results lead to an understanding of the dynamics of DBDs. Although in VD arrangements cathode-directed streamers appear especially in electronegative gases, their appearance is rather unlikely in SD arrangements. The application of DBDs for plasma-chemical reactions is determined by the productivity, with which the energy of the electric field can be converted into internal states of atoms and/or molecules. Depending on the desired product it could be both the generation of internal electronic states of molecules or atoms and dissociation products of molecules. The discharge current and current density of DBDs in both the SD and VD arrangements as well as the energy release and energy density

  14. Surface modification of polytetrafluoroethylene film using the atmospheric pressure glow discharge in air

    International Nuclear Information System (INIS)

    Fang, Z; Qiu, Y; Luo, Y

    2003-01-01

    The atmospheric pressure glow discharge (APGD) is more promising in industrial applications compared with glow discharges in a gas other than air or in low-pressure air, which needs an expensive vacuum system. In this paper, the APGD and dielectric barrier discharge (DBD) are generated in atmospheric air using a power-frequency voltage source, and the transition from DBD to APGD is achieved by varying the electrode arrangement. The differences between their discharge characteristics are shown by measurement of their electrical discharge parameters and observation of light-emission phenomena. The effects of APGD and DBD on polytetrafluoroethylene (PTFE) surface modification are studied. The surface properties are characterized by contact angle measurement, x-ray photoelectron spectroscopy and scanning electron microscopy. It is found that the APGD and DBD treatments modify the PTFE surface in both morphology and composition. APGD is more effective in PTFE surface modification than DBD as it can modify the surface more uniformly, implant more oxygen atoms into the surface and make the contact angle decline to a lower level. The experimental results are discussed

  15. Using Contaminant Transport Modeling to Determine Historical Discharges at the Surface

    Science.gov (United States)

    Fogwell, T. W.

    2013-12-01

    When it is determined that a contaminated site needs to be remediated, the issue of who is going to pay for that remediation is an immediate concern. This means that there needs to be a determination of who the responsible parties are for the existing contamination. Seldom is it the case that records have been made and kept of the surface contaminant discharges. In many cases it is possible to determine the relative amount of contaminant discharge at the surface of the various responsible parties by employing a careful analysis of the history of contaminant transport through the surface, through the vadose zone, and within the saturated zone. The process begins with the development of a dynamic conceptual site model that takes into account the important features of the transport of the contaminants through the vadose zone and in the groundwater. The parameters for this model can be derived from flow data available for the site. The resulting contaminant transport model is a composite of the vadose zone transport model, together with the saturated zone (groundwater) flow model. Any calibration of the model should be carefully employed in order to avoid using information about the conclusions of the relative discharge amounts of the responsible parties in determining the calibrated parameters. Determination of the leading edge of the plume is an important first step. It is associated with the first discharges from the surface of the site. If there were several discharging parties at the same time, then it is important to establish a chemical or isotopic signature of the chemicals that were discharged. The time duration of the first discharger needs to be determined as accurately as possible in order to establish the appropriate characterization of the leading portion of the resulting plume in the groundwater. The information about the first discharger and the resulting part of the plume associated with this discharger serves as a basis for the determination of the

  16. Treatment of Dyeing Wastewater by Using Positive Pulsed Corona Discharge to Water Surface

    International Nuclear Information System (INIS)

    Mok, Young Sun; Ahn, Hyun Tae; Kim, Joeng Tai

    2007-01-01

    This study investigated the treatment of textile-dyeing wastewater by using an electrical discharge technique (positive pulsed corona discharge). The high-voltage electrode was placed above the surface of the wastewater while the ground electrode was submerged in the wastewater. The electrical discharge starting at the tip of the high voltage electrode propagated toward the surface of the wastewater, producing various oxidative radicals and ozone. Oxygen was used as the working gas instead of air to prevent nitrogen oxides from forming. The simulated wastewater was made up with amaranth, which is a kind of azo dye. The results obtained showed that the chromaticity of the wastewater was almost completely removed within an hour. The ultraviolet/visible spectra of the wastewater treated by the electrical discharge revealed that the total hydrocarbon level also decreased significantly

  17. Two-dimensional simulation research of secondary electron emission avalanche discharge on vacuum insulator surface

    Science.gov (United States)

    Cai, Libing; Wang, Jianguo; Zhu, Xiangqin; Wang, Yue; Zhang, Dianhui

    2015-01-01

    Based on the secondary electron emission avalanche (SEEA) model, the SEEA discharge on the vacuum insulator surface is simulated by using a 2D PIC-MCC code developed by ourselves. The evolutions of the number of discharge electrons, insulator surface charge, current, and 2D particle distribution are obtained. The effects of the strength of the applied electric field, secondary electron yield coefficient, rise time of the pulse, length of the insulator on the discharge are investigated. The results show that the number of the SEEA electrons presents a quadratic dependence upon the applied field strength. The SEEA current, which is on the order of Ampere, is directly proportional to the field strength and secondary electron yield coefficient. Finally, the electron-stimulated outgassing is included in the simulation code, and a three-phase discharge curve is presented by the simulation, which agrees with the experimental data.

  18. Two-dimensional simulation research of secondary electron emission avalanche discharge on vacuum insulator surface

    International Nuclear Information System (INIS)

    Cai, Libing; Wang, Jianguo; Zhu, Xiangqin; Wang, Yue; Zhang, Dianhui

    2015-01-01

    Based on the secondary electron emission avalanche (SEEA) model, the SEEA discharge on the vacuum insulator surface is simulated by using a 2D PIC-MCC code developed by ourselves. The evolutions of the number of discharge electrons, insulator surface charge, current, and 2D particle distribution are obtained. The effects of the strength of the applied electric field, secondary electron yield coefficient, rise time of the pulse, length of the insulator on the discharge are investigated. The results show that the number of the SEEA electrons presents a quadratic dependence upon the applied field strength. The SEEA current, which is on the order of Ampere, is directly proportional to the field strength and secondary electron yield coefficient. Finally, the electron-stimulated outgassing is included in the simulation code, and a three-phase discharge curve is presented by the simulation, which agrees with the experimental data

  19. Investigation of some properties of Nylon-6 surface treated by corona discharge in helium

    International Nuclear Information System (INIS)

    Dumitrascu, N.; Surdu, S.; Popa, Gh.; Raileanu, D.

    1996-01-01

    In this work an easy and less expensive method of treatment has been used by corona discharge. This allows to modify the surface properties and especially to improve the compatibility of polymers with biological tissue. The Nylon-6 as a test material was chosen. A scanning electron microscope to visualize the morphology of the morphology of the surface and an IR spectrophotometer able to identify the amide groups and other as well, have been used. Morphology of the treated surface by corona discharge emphasis an etching an etching and/or a crosslinking of amorphous domains, generally important to improve the properties as wetting, dyeing, adhesion, etc. Over all treated surface there is significant blood compatible properties without the need of heparinization of surface. The treated surface influences the biological behaviour of micro-organisms, respectively, that surface is a favourable medium for division of cells and may increase their lifetime. (authors)

  20. Modification of the Steel Surface Treated by a Volume Discharge Plasma in Nitrogen at Atmospheric Pressure

    Science.gov (United States)

    Erofeev, M. V.; Shulepov, M. A.; Ivanov, Yu. F.; Oskomov, K. V.; Tarasenko, V. F.

    2016-03-01

    Effect of volume discharge plasma initiated by an avalanche electron beam on the composition, structure, and properties of the surface steel layer is investigated. Voltage pulses with incident wave amplitude up to 30 kV, full width at half maximum of about 4 ns, and wave front of about 2.5 ns were applied to the gap with an inhomogeneous electric field. Changes indicating the hardening effect of the volume discharge initiated by an avalanche electron beam are revealed in St3-grade steel specimens treated by the discharge of this type.

  1. Non-self-sustained discharge with hollow anode for plasma-based surface treatment

    Directory of Open Access Journals (Sweden)

    Misiruk Ivan O.

    2016-06-01

    Full Text Available The paper discusses plasma methods for surface modification using the non-self-sustained glow discharge with a hollow anode. This discharge is characterised by low voltage and high values of electron and ion currents. It can be easily excited in vacuum-arc installations that are widely used for coatings deposition. It is shown that such type of discharge may be effectively used for ion pumping, film deposition, ion etching, diffusion saturation of metallic materials, fusion and brazing of metals, and for combined application of above mentioned technologies in a single vacuum cycle.

  2. PEO-like Plasma Polymers Prepared by Atmospheric Pressure Surface Dielectric Barrier Discharge

    Czech Academy of Sciences Publication Activity Database

    Gordeev, I.; Choukourov, A.; Šimek, Milan; Prukner, Václav; Biederman, H.

    2012-01-01

    Roč. 9, č. 8 (2012), s. 782-791 ISSN 1612-8850 R&D Projects: GA ČR(CZ) GD104/09/H080 Institutional research plan: CEZ:AV0Z20430508 Keywords : fibrinogen * non-fouling properties * PEO * plasma polymerization * surface dielectric barrier discharge Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 3.730, year: 2012

  3. Theoretical insight into ArO2 surface-wave microwave discharges

    OpenAIRE

    2010-01-01

    Abstract A zero-dimensional kinetic model has been developed to investigate the coupled electron and heavy-particle kinetics in Ar-O 2 surface-wave microwave discharges generated in long cylindrical tubes, such as those launched with a surfatron or a surfaguide. The model has been validated by comparing the calculated electron temperature and species densities with experimental data available in the literature for different discharge conditions. Systematic studies have been carried out for...

  4. Program for estimating surface air concentrations of NPP discharge radionuclides

    International Nuclear Information System (INIS)

    Ivanov, E.A.; Ramzina, T.V.; Sokolova, E.Yu.

    1986-01-01

    Methods for calculating short-term values of ground-level specific activity in the NPP region and the values averaged for an extended period are described. These methods are realized in the LAURA program on the FORTRAN 4 language for the ES-1033 computer with the OS ES translator and the EMQ-666 computer. As a result of program execution, the user receives the following information: 1) the table for radionuclide surface specific activity values depending on the direction and distance from the source; the wind rose matrix and conditional probabilities of the atmosphere stability category; 2) the map of isolines of radionuclide specific activity in a grid given in polar coordinates with marks of level lines according to their values

  5. Jacketed lamp bulb envelope

    Science.gov (United States)

    MacLennan, Donald A.; Turner, Brian P.; Gitsevich, Aleksandr; Bass, Gary K.; Dolan, James T.; Kipling, Kent; Kirkpatrick, Douglas A.; Leng, Yongzhang; Levin, Izrail; Roy, Robert J.; Shanks, Bruce; Smith, Malcolm; Trimble, William C.; Tsai, Peter

    2001-01-01

    A jacketed lamp bulb envelope includes a ceramic cup having an open end and a partially closed end, the partially closed end defining an aperture, a lamp bulb positioned inside the ceramic cup abutting the aperture, and a reflective ceramic material at least partially covering a portion of the bulb not abutting the aperture. The reflective ceramic material may substantially fill an interior volume of the ceramic cup not occupied by the bulb. The ceramic cup may include a structural feature for aiding in alignment of the jacketed lamp bulb envelope in a lamp. The ceramic cup may include an external flange about a periphery thereof. One example of a jacketed lamp bulb envelope includes a ceramic cup having an open end and a closed end, a ceramic washer covering the open end of the ceramic cup, the washer defining an aperture therethrough, a lamp bulb positioned inside the ceramic cup abutting the aperture, and a reflective ceramic material filling an interior volume of the ceramic cup not occupied by the bulb. A method of packing a jacketed lamp bulb envelope of the type comprising a ceramic cup with a lamp bulb disposed therein includes the steps of filling the ceramic cup with a flowable slurry of reflective material, and applying centrifugal force to the cup to pack the reflective material therein.

  6. Surface treatment of polyethylene terephthalate film using atmospheric pressure glow discharge in air

    International Nuclear Information System (INIS)

    Fang Zhi; Qiu Yuchang; Wang Hui

    2004-01-01

    Non-thermal plasmas under atmospheric pressure are of great interest in polymer surface processing because of their convenience, effectiveness and low cost. In this paper, the treatment of Polyethylene terephthalate (PET) film surface for improving hydrophilicity using the non-thermal plasma generated by atmospheric pressure glow discharge (APGD) in air is conducted. The discharge characteristics of APGD are shown by measurement of their electrical discharge parameters and observation of light-emission phenomena, and the surface properties of PET before and after the APGD treatment are studied using contact angle measurement, x-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). It is found that the APGD is homogeneous and stable in the whole gas gap, which differs from the commonly filamentary dielectric barrier discharge (DBD). A short time (several seconds) APGD treatment can modify the surface characteristics of PET film markedly and uniformly. After 10 s APGD treatment, the surface oxygen content of PET surface increases to 39%, and the water contact angle decreases to 19 degree, respectively. (authors)

  7. Roughness modification of surfaces treated by a pulsed dielectric barrier discharge

    CERN Document Server

    Dumitrascu, N; Apetroaei, N; Popa, G

    2002-01-01

    Local modifications of surface roughness are very important in many applications, as this surface property is able to generate new mechano-physical characteristics of a large category of materials. Roughness is one of the most important parameters used to characterize and control the surface morphology, and techniques that allow modifying and controlling the surface roughness present increasing interest. In this respect we propose the dielectric barrier discharge (DBD) as a simple and low cost method that can be used to induce controlled roughness on various surfaces in the nanoscale range. DBD is produced in helium, at atmospheric pressure, by a pulsed high voltage, 28 kV peak to peak, 13.5 kHz frequency and 40 W power. This type of discharge is a source of energy capable of modifying the physico-chemical properties of the surfaces without affecting their bulk properties. The discharge is characterized by means of electrical probes and, in order to analyse the heat transfer rate from the discharge to the tre...

  8. Cleaning method of aluminium surface by argon discharge for photon factory

    International Nuclear Information System (INIS)

    Mizuno, Hajime; Yamaguchi, Hiroshi; Watabe, Hiromi; Horikoshi, Gen-ichi; Mathewson, A.G.

    1978-01-01

    In the Photon Factory program of High Energy Research Laboratory, in which the electron storage ring as a photon source stores the electron beam of 2.5 GeV and 500 mA, beam intensity the probability of gas discharge from the inner surface of doughnut wall due to electron bombardment (for 100 eV electorns) must be limited to 1 x 10 -6 or less, according to the estimation by A.G. Mathewson and others. The pressure inside the ring can be maintained at 1 x 10 -9 Torr only with the above probability value. The standard surface treatment of degreasing and evacuation for 24 hours with heating at 150 deg. C can be of no practical use. Since the ion bombardment of surfaces by argon glow discharge is effective for decreasing the probability, the reduction of the probability by argon discharge cleaning was measured with the surface of aluminium, which is planned to be used as the doughnut material. Two methods were employed for the measurement; the one is analysis of gases being discharged, by introducting them to the analyzing chamber during argon discharge and the other is the measurement of the probability when bombardment with electrons of 100 eV is applied, after stopping argon introduction and evacuating after argon discharge had been performed for a definite period. As a result, the probability of approximately 2 x 10 -5 at the beginning of electron beam incidence was obtained by adding argon discharge cleaning to the standard method. This is estimated to correspondent to approximately 25 mA of beam intensity, which is equivalent to 1/20 of the planned value. (Wakatsuki, Y.)

  9. Dielectric barrier discharge for surface treatment: application to selected polymers in film and fibre form

    International Nuclear Information System (INIS)

    Borcia, G; Anderson, C A; Brown, N M D

    2003-01-01

    In this paper, we report and discuss a surface treatment method, using a dielectric barrier discharge (DBD) of random filamentary type. This offers a convenient, reliable and economic alternative for the controlled modification (so far, largely dependent on surface oxidation) of various categories of material surfaces. Remarkably uniform treatment and markedly stable modified surface properties result over the entire area of the test surfaces exposed to the discharge even at transit speeds simulating those associated with continuous on-line processing. The effects of air-DBD treatment on the surfaces of various polymer films and polymer-based fabrics were studied. The dielectric barrier concerned has been characterized in terms of the energy deposited by the discharge at the processing electrodes and the resultant modifications of the surface properties of the treated samples were investigated using x-ray photoelectron spectroscopy, contact angle/wickability measurement and scanning electron microscopy. The influence of the surface treatment parameters, such as the energy deposited by the discharge, the inter-electrode gap and the treatment time were examined and related to the post-treatment surface characteristics of the materials processed. Relationships between the processing parameters and the properties of the DBD treated samples were thus established. Of the three process variables investigated, the duration of the treatment was found to have a more significant effect on the surface modifications found than did the discharge energy or the inter-electrode gap. Very short air-DBD treatments (fractions of a second in duration) markedly and uniformly modified the surface characteristics for all the materials treated, to the effect that wettability, wickability and the level of oxidation of the surface appear to be increased strongly within the first 0.1-0.2 s of treatment. Any subsequent surface modification following longer treatment (>1.0 s) was less important

  10. Dielectric barrier discharge for surface treatment: application to selected polymers in film and fibre form

    Science.gov (United States)

    Borcia, G.; Anderson, C. A.; Brown, N. M. D.

    2003-08-01

    In this paper, we report and discuss a surface treatment method, using a dielectric barrier discharge (DBD) of random filamentary type. This offers a convenient, reliable and economic alternative for the controlled modification (so far, largely dependent on surface oxidation) of various categories of material surfaces. Remarkably uniform treatment and markedly stable modified surface properties result over the entire area of the test surfaces exposed to the discharge even at transit speeds simulating those associated with continuous on-line processing. The effects of air-DBD treatment on the surfaces of various polymer films and polymer-based fabrics were studied. The dielectric barrier concerned has been characterized in terms of the energy deposited by the discharge at the processing electrodes and the resultant modifications of the surface properties of the treated samples were investigated using x-ray photoelectron spectroscopy, contact angle/wickability measurement and scanning electron microscopy. The influence of the surface treatment parameters, such as the energy deposited by the discharge, the inter-electrode gap and the treatment time were examined and related to the post-treatment surface characteristics of the materials processed. Relationships between the processing parameters and the properties of the DBD treated samples were thus established. Of the three process variables investigated, the duration of the treatment was found to have a more significant effect on the surface modifications found than did the discharge energy or the inter-electrode gap. Very short air-DBD treatments (fractions of a second in duration) markedly and uniformly modified the surface characteristics for all the materials treated, to the effect that wettability, wickability and the level of oxidation of the surface appear to be increased strongly within the first 0.1-0.2 s of treatment. Any subsequent surface modification following longer treatment (>1.0 s) was less important

  11. Lamp for sunshine simulation

    DEFF Research Database (Denmark)

    2016-01-01

    A lamp system is provided, comprising a lamp with a lamp housing accommodating a plurality of light sources for emission of visible light, including blue light, a time keeping unit, a light sensor for sensing intensity of light incident upon it, and a light controller configured for controlling...... the plurality of light sources in response to the intensity of light sensed by the light sensor and the time provided by the time keeping unit, characterized in that the lamp emits blue light for a selected time period, wherein the blue light has a luminous flux ranging from 50 lux to 200 lux and, preferably......, an irradiance that is larger than 5 mW/nm/m2 in a selected wavelength range, such as in the wavelength range from 440 nm to 500 nm, as measured at a distance of 3 metres from the lamp....

  12. Experimental Investigation of Surface Layer Properties of High Thermal Conductivity Tool Steel after Electrical Discharge Machining

    Directory of Open Access Journals (Sweden)

    Rafał Świercz

    2017-12-01

    Full Text Available New materials require the use of advanced technology in manufacturing complex shape parts. One of the modern materials widely used in the tool industry for injection molds or hot stamping dies is high conductivity tool steel (HTCS 150. Due to its hardness (55 HRC and thermal conductivity at 66 W/mK, this material is difficult to machine by conventional treatment and is being increasingly manufactured by nonconventional technology such as electrical discharge machining (EDM. In the EDM process, material is removed from the workpiece by a series of electrical discharges that cause changes to the surface layers properties. The final state of the surface layer directly influences the durability of the produced elements. This paper presents the influence of EDM process parameters: discharge current Ic and the pulse time ton on surface layer properties. The experimental investigation was carried out with an experimental methodology design. Surface layers properties including roughness 3D parameters, the thickness of the white layer, heat affected zone, tempered layer and occurring micro cracks were investigated and described. The influence of the response surface methodology (RSM of discharge current Ic and the pulse time ton on the thickness of the white layer and roughness parameters Sa, Sds and Ssc were described and established.

  13. Partial discharge patterns and surface deterioration in voids in filled and unfilled epoxy

    DEFF Research Database (Denmark)

    Holbøll, Joachim; Henriksen, Mogens

    1992-01-01

    /height analyses were performed over a period of 2400 h and showed very characteristic discharge patterns for each material combination. A unique behavior with regard to changes of pulse repetition rate and maximum apparent charge was observed for PD in alumina- and silica-filled epoxy. The void surfaces were...

  14. Partial discharge patterns related to surface deterioration in voids in epoxy

    DEFF Research Database (Denmark)

    Holbøll, Joachim; Henriksen, Mogens

    1990-01-01

    Results are presented from an investigation of the relationship between changes in partial discharge patterns and the surface deterioration process taking place in small naturally formed spherical voids in epoxy plastic. The voids were exposed to a moderate electric stress above inception level...

  15. Study of discharges produced by surface waves under medium and high pressure: application to chemical analysis

    International Nuclear Information System (INIS)

    Laye epouse Granier, Agnes

    1986-01-01

    This report deals with the study of microwave discharges produced in argon gas by surface waves in the 20-760 Torr pressure range. Application to chemical analysis by emission optical spectroscopy is also investigated. First of all we study the propagation of a surface wave in a bounded plasma in which the effective collision frequency for momentum transfer ν is higher than the excitation one. The axial electron density profile is determined from two diagnostic techniques, i.e., phase variations of the wave field and Stark broadening of H β line. Then we deduce the discharge characteristics ν, θ (maintaining power of an electron-ion pair) and E eff (effective electric field for discharge sustaining) from the electron density profile. Then an energy balance of the discharge is developed. It explains the change of operating conditions in the 20-50 Torr range. At low pressure the discharge is governed by ambipolar diffusion whereas at high pressure, the electrons are mainly lost by volume recombination of Ar 2 + . Finally, we report on chemical analysis experiment of gases (optimum sensibility in found near 100 Torr) and of metallic solutions sprayed by a graphite oven. Performances of such a design and ICP plasma torches are compared. (author) [fr

  16. Investigation of atmospheric dielectric barrier discharge and its application to surface modification of textile material

    International Nuclear Information System (INIS)

    Xiaoliang Tang; Gao Qiu; Hankun Xie; Xianping Feng

    2005-01-01

    The dielectric barrier discharge (DBD) is characterized by the presence of at least one insulating layer in contact with the discharge between two planar or cylindrical electrodes connected to an ac power supply. In this paper, the spectral lines of plasma emission at atmospheric pressure were recorded by using a grating spectrograph, and all signals will be directly and immediately sent to the computer for data processing and analysis during the experiments. The spectrum lines of nitrogen, helium and argon plasma emission at atmospheric pressure were separately recorded and qualitatively analyzed using spectral diagnosis equipment of atmospheric pressure DBD plasma. The spectrum lines of the second positive system of nitrogen (c 3 π μ → B 3 Π g ), two characteristic spectrum lines of helium (3 1 P 1 → 2 1 S 0 , 3 3 D → 3 3 P), and all of neutral argon atom spectrum lines in the range 680 to 780 nm are recognized. For controlling the process of material surface modification promptly, the electron temperature of DBD plasma is quantitatively analyzed using relative intensity of argon spectrum lines. The relationships among the plasma parameters, such as discharge current and discharge power measured by Lissajous figure of the oscilloscope, were analyzed by using improved DBD equipment. The variation of plasma discharge current following the change of discharge gaps indicates an existence of critical gap distance. When the gap between electrodes is less than that the critical gap, a quasi-stable atmospheric pressure DBD plasma source can be achieved after carefully controlled discharge voltage and current. The experimental results indicate that a critical discharge gap is an important parameter to improve the quality of materials processing. The result is of great importance to DBD at atmospheric pressure and its application to materials processing. (author)

  17. AGING EFFECTS OF REPEATEDLY GLOW-DISCHARGED POLYETHYLENE - INFLUENCE ON CONTACT-ANGLE, INFRARED-ABSORPTION, ELEMENTAL SURFACE-COMPOSITION, AND SURFACE-TOPOGRAPHY

    NARCIS (Netherlands)

    VANDERMEI, HC; STOKROOS, [No Value; SCHAKENRAAD, JM; BUSSCHER, HJ

    1991-01-01

    Aging effects of repeatedly oxygen glow-discharged polyethylene surfaces were determined by water contact angle measurements, infrared (IR) spectroscopy, X-ray photoelectron (XPS) spectroscopy, and surface topography determination. Glow-discharged surfaces were stored at room temperature and in

  18. Stabilization of a cold cathode electron beam glow discharge for surface treatment

    Energy Technology Data Exchange (ETDEWEB)

    Mingolo, N.; Gonzalez, C.R. [Lab. de Haces Dirigidos, Depto. de Fisica, Facultad de Ingenieria, Universidad de Buenos Aires, Paseo Colon 850, 1063 Buenos Aires (Argentina); Martinez, O.E. [Lab. de Electronica Cuantica, Depto. de Fisica, Universidad de Buenos Aires, Pabellon 1, Ciudad Universitaria, 1428 Buenos Aires (Argentina); Rocca, J.J. [Department of Electrical Engineering, Colorado State University, Fort Collins, Colorado 80523 (United States)

    1997-10-01

    We have demonstrated that the reproducibility of electron beam pulses generated by a high power, cold cathode glow discharge is greatly improved by adding a small continuous keep-alive discharge current. A current of the order of 200 {mu}A was found to limit the shot to shot current variation to within 1.5{percent}. This stabilization in turn reduces by an order of magnitude the fluctuations of the energy density deposited on the target, demonstrating a reliable energy source for surface treatment. {copyright} {ital 1997 American Institute of Physics.}

  19. 49 CFR 393.25 - Requirements for lamps other than head lamps.

    Science.gov (United States)

    2010-10-01

    ... lamps; school bus warning lamps; amber warning lamps or flashing warning lamps on tow trucks and... MOTOR CARRIER SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION FEDERAL MOTOR CARRIER SAFETY...

  20. The study of discharge cleaning in the JFT-2 tokamak with surface observation by AES

    International Nuclear Information System (INIS)

    Gomay, Yoshio; Tazima, Teruhiko; Fujisawa, Noboru; Suzuki, Norio; Konoshima, Shigeru

    1976-07-01

    Noticeable correlations were observed between the changes of discharge characteristics, wall conditions and typical mass peaks with discharge cleaning in the JFT-2 tokamak. Atomic composition of the vacuum wall surface observed by AES becomes constant with continuing discharge cleaning in the level except hydrogen and helium: 30-50% C, 20-30% Mo, 15-30% stainless steel elements and 10-15% O. The stable reproducible plasma with Z sub(eff)=4.5 was obtained in this wall condition. The limiter and vacuum wall materials (Mo and 304 stainless steel, respectively), carbon and oxygen were observed depositing on the wall in the thickness of about 300 A at the minimum inner radius of the vacuum chamber and 40 A nearly at the maximum after 2900 cleaning pulses. The mechanism determining the wall condition is also discussed. (auth.)

  1. A global model of cylindrical and coaxial surface-wave discharges

    Science.gov (United States)

    Kemaneci, Efe; Mitschker, Felix; Rudolph, Marcel; Szeremley, Daniel; Eremin, Denis; Awakowicz, Peter; Brinkmann, Ralf Peter

    2017-06-01

    A volume-averaged global model is developed to investigate surface-wave discharges inside either cylindrical or coaxial structures. The neutral and ion wall flux is self-consistently estimated based on a simplified analytical description both for electropositive and electronegative plasmas. The simulation results are compared with experimental data from various discharge setups of either argon or oxygen, measured or obtained from the literature over a wide range of pressure and power, for a continuous and a pulse-modulated power input. A good agreement is observed between the simulations and the measurements. The contribution of the wall flux on the net loss rates is quantified for a variety of species in different discharge setups. A coaxial plasmaline is further investigated to reveal the detailed behaviour of plasma properties with respect to input power and pressure.

  2. Low pressure plasma discharges for the sterilization and decontamination of surfaces

    International Nuclear Information System (INIS)

    Rossi, F; Rauscher, H; Hasiwa, M; Gilliland, D; Kylian, O

    2009-01-01

    The mechanisms of sterilization and decontamination of surfaces are compared in direct and post discharge plasma treatments in two low-pressure reactors, microwave and inductively coupled plasma. It is shown that the removal of various biomolecules, such as proteins, pyrogens or peptides, can be obtained at high rates and low temperatures in the inductively coupled plasma (ICP) by using Ar/O 2 mixtures. Similar efficiency is obtained for bacterial spores. Analysis of the discharge conditions illustrates the role of ion bombardment associated with O radicals, leading to a fast etching of organic matter. By contrast, the conditions obtained in the post discharge lead to much lower etching rates but also to a chemical modification of pyrogens, leading to their de-activation. The advantages of the two processes are discussed for the application to the practical case of decontamination of medical devices and reduction of hospital infections, illustrating the advantages and drawbacks of the two approaches.

  3. Low pressure plasma discharges for the sterilization and decontamination of surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Rossi, F; Rauscher, H; Hasiwa, M; Gilliland, D [European Commission, Joint Research Centre, Institute for Health and Consumer Protection, Via E. Fermi 2749, 21027 Ispra (Vatican City State, Holy See) (Italy); Kylian, O [Faculty of Mathematics and Physics, Charles University, V Holesovickach 2, Prague 8, 180 00 (Czech Republic)], E-mail: francois.rossi@jrc.ec.europa.eu

    2009-11-15

    The mechanisms of sterilization and decontamination of surfaces are compared in direct and post discharge plasma treatments in two low-pressure reactors, microwave and inductively coupled plasma. It is shown that the removal of various biomolecules, such as proteins, pyrogens or peptides, can be obtained at high rates and low temperatures in the inductively coupled plasma (ICP) by using Ar/O{sub 2} mixtures. Similar efficiency is obtained for bacterial spores. Analysis of the discharge conditions illustrates the role of ion bombardment associated with O radicals, leading to a fast etching of organic matter. By contrast, the conditions obtained in the post discharge lead to much lower etching rates but also to a chemical modification of pyrogens, leading to their de-activation. The advantages of the two processes are discussed for the application to the practical case of decontamination of medical devices and reduction of hospital infections, illustrating the advantages and drawbacks of the two approaches.

  4. Multi-Parameter Analysis of Surface Finish in Electro-Discharge Machining of Tool Steels

    Directory of Open Access Journals (Sweden)

    Cornelia Victoria Anghel

    2006-10-01

    Full Text Available The paper presents a multi- parameter analysis of surface finish imparted to tool-steel plates by electro-discharge machining (EDM is presented. The interrelationship between surface texture parameters and process parameters is emphasized. An increased number of parameters is studied including amplitude, spacing, hybrid and fractal parameters,, as well. The correlation of these parameters with the machining conditions is investigated. Observed characteristics become more pronounced, when intensifying machining conditions. Close correlation exists between certain surface finish parameters and EDM input variables and single and multiple statistical regression models are developed.

  5. Surface modification of nanofibrillated cellulose films by atmospheric pressure dielectric barrier discharge

    DEFF Research Database (Denmark)

    Siró, Istvan; Kusano, Yukihiro; Norrman, Kion

    2013-01-01

    of atmospheric pressure plasma treatment, the water contact angle of NFC films increased and the values were comparable with those of PLA films. On the other hand, surface chemical characterization revealed inhomogeneity of the plasma treatment and limited improvement in adhesion between NFC and PLA films......A dielectric barrier discharge in a gas mixture of tetrafluoromethane (CF4) and O2 was used for tailoring the surface properties of nanofibrillated cellulose (NFC) films. The surface chemical composition of plasma-modified NFC was characterized by means of X-ray photoelectron spectroscopy and time....... Further research in this direction is required in order to enhance the uniformity of the plasma treatment results....

  6. Characterization of surface dielectric barrier discharge influenced by intermediate frequency for ozone production

    International Nuclear Information System (INIS)

    Abdelaziz, Ayman A; Ishijima, Tatsuo; Seto, Takafumi; Otani, Yoshio; Osawa, Naoki; Wedaa, Hassan

    2016-01-01

    The aim of this study is to investigate the effect of the intermediate frequency (1–10 kHz) of the sinusoidal driving voltage on the characteristics of a developed surface dielectric barrier discharge (SDBD)-based reactor having spikes on its discharge electrode. Moreover, its influence on the production of ozone and nitrogen oxide byproducts is evaluated. The results show that SDBD is operated in the filamentary mode at all the frequencies. Nevertheless, the pulses of the discharge current at high frequencies are much denser and have higher amplitudes than those at low frequencies. The analysis of the power consumed in the reactor shows that a small portion of the input power is dissipated in the dielectric material of SDBD source, whereas the major part of the power is consumed in the plasma discharge. The results of the ozone production show that higher frequencies have a slightly adverse effect on the ozone production at relatively high energy density values, where the ozone concentration is slightly decreased when the frequency is increased at the same energy density. The temperature of the discharge channels and gas is not a crucial factor for the decomposition of ozone in this reactor, while the results of the measurements of nitrogen oxides characteristics indicate that the formation of NO and NO 2 has a significant adverse effect on the production efficiency of ozone due to their oxidation to another nitrogen oxides and their catalytic effect. (paper)

  7. Capturing attention to brake lamps.

    Science.gov (United States)

    McIntyre, Scott E

    2008-03-01

    Rear-end collisions and distraction are major concerns and basic research in cognitive psychology concerning attention in visual search is applicable to these problems. It is proposed that using yellow tail lamps will result in faster reaction times and fewer errors than current tail lamp coloring (red) in detecting brake lamps (red) in a "worst case" scenario where brake lamp onset, lamp intensity and temporal and contextual cues are not available. Participants engaged in a visual search for brake lamps in two conditions, one using red tail lamps with red brake lamps and one with the proposed combination of yellow tail lamps with red brake lamps in which they indicated by keyboard response the presence or absence of braking cars. The hypothesis that separating brake and tail lamps by color alone would produce faster RTs, reduce errors, and provide greater conspicuity was supported. Drivers and non-drivers detect absence and presence of red brake lamps faster and with greater accuracy with the proposed yellow tail lamps than red tail lamps without the aid of any of the aforementioned cues. Vehicle conspicuity will be improved and reductions in rear-end collisions and other accidents will be reduced by implementing the proposed yellow tail lamp coloring.

  8. Surface treatment of zinc anodes to improve discharge capacity and suppress hydrogen gas evolution

    Science.gov (United States)

    Cho, Yung-Da; Fey, George Ting-Kuo

    The shape change and redistribution of zinc anode material over the electrode during repeated cycling have been identified as the main factors that can limit the life of alkaline zinc-air batteries. Li 2O-2B 2O 3 (lithium boron oxide, LBO) glass with high Li + conductivity and stability can be coated on the surface of zinc powders. The structures of the surface-treated and pristine zinc powders were characterized by XRD, SEM, TEM, ESCA and BET analyses. XRD patterns of LBO-coated zinc powders revealed that the coating did not affect the crystal structure. TEM images of LBO-coated on the zinc particles were compact with an average passivation layer of about 250 nm. The LBO layer can prevent zinc from coming into direct contact with the KOH electrolyte and minimize the side reactions within the batteries. The 0.1 wt.% LBO-coated zinc anode material provided an initial discharge capacity of 1.70 Ah at 0.5 V, while the pristine zinc electrode delivered only 1.57 Ah. A surface-treated zinc electrode can increase discharge capacity, decrease hydrogen evolution reaction, and reduce self-discharge. The results indicated that surface treatment should be effective for improving the comprehensive properties of anode materials for zinc-air batteries.

  9. Discharge filamentary patterns produced by pulsed corona discharge at the interface between a water surface and air

    Czech Academy of Sciences Publication Activity Database

    Lukeš, Petr; Člupek, Martin; Babický, Václav

    2011-01-01

    Roč. 39, č. 11 (2011), s. 2644-2645 ISSN 0093-3813 R&D Projects: GA AV ČR IAAX00430802 Institutional research plan: CEZ:AV0Z20430508 Keywords : corona discharge * water * conductivity * air Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 1.174, year: 2011

  10. High-voltage electrode optimization towards uniform surface treatment by a pulsed volume discharge

    Science.gov (United States)

    Ponomarev, A. V.; Pedos, M. S.; Scherbinin, S. V.; Mamontov, Y. I.; Ponomarev, S. V.

    2015-11-01

    In this study, the shape and material of the high-voltage electrode of an atmospheric pressure plasma generation system were optimised. The research was performed with the goal of achieving maximum uniformity of plasma treatment of the surface of the low-voltage electrode with a diameter of 100 mm. In order to generate low-temperature plasma with the volume of roughly 1 cubic decimetre, a pulsed volume discharge was used initiated with a corona discharge. The uniformity of the plasma in the region of the low-voltage electrode was assessed using a system for measuring the distribution of discharge current density. The system's low-voltage electrode - collector - was a disc of 100 mm in diameter, the conducting surface of which was divided into 64 radially located segments of equal surface area. The current at each segment was registered by a high-speed measuring system controlled by an ARM™-based 32-bit microcontroller. To facilitate the interpretation of results obtained, a computer program was developed to visualise the results. The program provides a 3D image of the current density distribution on the surface of the low-voltage electrode. Based on the results obtained an optimum shape for a high-voltage electrode was determined. Uniformity of the distribution of discharge current density in relation to distance between electrodes was studied. It was proven that the level of non-uniformity of current density distribution depends on the size of the gap between electrodes. Experiments indicated that it is advantageous to use graphite felt VGN-6 (Russian abbreviation) as the material of the high-voltage electrode's emitting surface.

  11. Study on effect of tool electrodes on surface finish during electrical discharge machining of Nitinol

    Science.gov (United States)

    Sahu, Anshuman Kumar; Chatterjee, Suman; Nayak, Praveen Kumar; Sankar Mahapatra, Siba

    2018-03-01

    Electrical discharge machining (EDM) is a non-traditional machining process which is widely used in machining of difficult-to-machine materials. EDM process can produce complex and intrinsic shaped component made of difficult-to-machine materials, largely applied in aerospace, biomedical, die and mold making industries. To meet the required applications, the EDMed components need to possess high accuracy and excellent surface finish. In this work, EDM process is performed using Nitinol as work piece material and AlSiMg prepared by selective laser sintering (SLS) as tool electrode along with conventional copper and graphite electrodes. The SLS is a rapid prototyping (RP) method to produce complex metallic parts by additive manufacturing (AM) process. Experiments have been carried out varying different process parameters like open circuit voltage (V), discharge current (Ip), duty cycle (τ), pulse-on-time (Ton) and tool material. The surface roughness parameter like average roughness (Ra), maximum height of the profile (Rt) and average height of the profile (Rz) are measured using surface roughness measuring instrument (Talysurf). To reduce the number of experiments, design of experiment (DOE) approach like Taguchi’s L27 orthogonal array has been chosen. The surface properties of the EDM specimen are optimized by desirability function approach and the best parametric setting is reported for the EDM process. Type of tool happens to be the most significant parameter followed by interaction of tool type and duty cycle, duty cycle, discharge current and voltage. Better surface finish of EDMed specimen can be obtained with low value of voltage (V), discharge current (Ip), duty cycle (τ) and pulse on time (Ton) along with the use of AlSiMg RP electrode.

  12. High-voltage electrode optimization towards uniform surface treatment by a pulsed volume discharge

    International Nuclear Information System (INIS)

    Ponomarev, A V; Pedos, M S; Scherbinin, S V; Mamontov, Y I; Ponomarev, S V

    2015-01-01

    In this study, the shape and material of the high-voltage electrode of an atmospheric pressure plasma generation system were optimised. The research was performed with the goal of achieving maximum uniformity of plasma treatment of the surface of the low-voltage electrode with a diameter of 100 mm. In order to generate low-temperature plasma with the volume of roughly 1 cubic decimetre, a pulsed volume discharge was used initiated with a corona discharge. The uniformity of the plasma in the region of the low-voltage electrode was assessed using a system for measuring the distribution of discharge current density. The system's low-voltage electrode - collector - was a disc of 100 mm in diameter, the conducting surface of which was divided into 64 radially located segments of equal surface area. The current at each segment was registered by a high-speed measuring system controlled by an ARM™-based 32-bit microcontroller. To facilitate the interpretation of results obtained, a computer program was developed to visualise the results. The program provides a 3D image of the current density distribution on the surface of the low-voltage electrode. Based on the results obtained an optimum shape for a high-voltage electrode was determined. Uniformity of the distribution of discharge current density in relation to distance between electrodes was studied. It was proven that the level of non-uniformity of current density distribution depends on the size of the gap between electrodes. Experiments indicated that it is advantageous to use graphite felt VGN-6 (Russian abbreviation) as the material of the high-voltage electrode's emitting surface. (paper)

  13. Evaluating the vulnerability of surface waters to antibiotic contamination from varying wastewater treatment plant discharges

    International Nuclear Information System (INIS)

    Batt, Angela L.; Bruce, Ian B.; Aga, Diana S.

    2006-01-01

    Effluents from three wastewater treatment plants with varying wastewater treatment technologies and design were analyzed for six antibiotics and caffeine on three sampling occasions. Sulfamethoxazole, trimethoprim, ciprofloxacin, tetracycline, and clindamycin were detected in the effluents at concentrations ranging from 0.090 to 6.0 μg/L. Caffeine was detected in all effluents at concentrations ranging from 0.19 to 9.9 μg/L. These findings indicate that several conventional wastewater management practices are not effective in the complete removal of antibiotics, and their discharges have a large potential to affect the aquatic environment. To evaluate the persistence of antibiotics coming from the wastewater discharges on the surrounding surface waters, samples were collected from the receiving streams at 10-, 20- and 100-m intervals. Ciprofloxacin, sulfamethoxazole, and clindamycin (0.043 to 0.076 μg/L) were found as far as 100 m from the discharge point, which indicates the persistence of these drugs in surface waters. - This work investigates the extent of antibiotic concentrations in receiving waters from discharges of wastewater treatment plants

  14. Acid-base status of soils in groundwater discharge zones — relation to surface water acidification

    Science.gov (United States)

    Norrström, Ann Catrine

    1995-08-01

    Critical load calculations have suggested that groundwater at depth of 2 m in Sweden is very sensitive to acid load. As environmental isotope studies have shown that most of the runoff in streams has passed through the soil, there is a risk in the near future of accelerated acidification of surface waters. To assess the importance of the last soil horizon of contact before discharge, the upper 0-0.2m of soils in seven discharge zones were analysed for pools of base cations, acidity and base saturation. The sites were about 3-4 m 2 in size and selected from two catchments exposed to different levels of acid deposition. The soils in the seven sites had high concentrations of exchangeable base cations and consequently high base saturation. The high correlation ( r2 = 0.74) between base saturation in the soils of the discharge zones and mean pH of the runoff waters suggested that the discharge zone is important for surface water acidification. The high pool of exchangeable base cations will buffer initially against the acid load. As the cation exchange capacity (meq dm -3) and base saturation were lower in the sites from the catchment receiving lower deposition, these streams may be more vulnerable to acidification in the near future. The high concentration of base cations in non-exchangeable fractions may also buffer against acidification as it is likely that some of these pools will become exchangeable with time.

  15. Hardness and structure changes at surface in electrical discharge machined steel C 3840

    International Nuclear Information System (INIS)

    Karastojkovic, Z.; Janjusevic, Z.

    2003-01-01

    The electrical discharge machining (EDM) of both hard and soft materials became an important technique in industrial applications. This technique has an advantage in producing of structural/tool parts of complex geometry. The EDM is based on electrical phenomena, when the treated surface undergoes to erosion. The first step in EDM, the melting of thin surface layer, frequently is neglected. In this paper the changes of hardness and structure at surface layer, after EDM is applied on steel C 3840, will be discussed. The steel C- 3840 was quenched and tempered to hardness of 63 HRC, at surface, and than machined by electrical discharging. The changed, white, layer is just a product of melting and decarburization processes. The white layer is registered at surface by using a metallographic investigation. Hardness profile is measured from surface to the interior of material. The achievement of local high temperatures during EDM is resulting on melt and erosion of material. Besides of these effects, during EDM were happened some minor but not a neglectible effects, primary on structure changes on treated surface. It would be expected that melting, even an evaporation of melted metal, and further the phase transformation have an important influence on the starting structure. (Original)

  16. Evaluation of Fatigue Behavior and Surface Characteristics of Aluminum Alloy 2024 T6 After Electric Discharge Machining

    Science.gov (United States)

    Mehmood, Shahid; Shah, Masood; Pasha, Riffat Asim; Sultan, Amir

    2017-10-01

    The effect of electric discharge machining (EDM) on surface quality and consequently on the fatigue performance of Al 2024 T6 is investigated. Five levels of discharge current are analyzed, while all other electrical and nonelectrical parameters are kept constant. At each discharge current level, dog-bone specimens are machined by generating a peripheral notch at the center. The fatigue tests are performed on four-point rotating bending machine at room temperature. For comparison purposes, fatigue tests are also performed on the conventionally machined specimens. Linearized SN curves for 95% failure probability and with four different confidence levels (75, 90, 95 and 99%) are plotted for each discharge current level as well as for conventionally machined specimens. These plots show that the electric discharge machined (EDMed) specimens give inferior fatigue behavior as compared to conventionally machined specimen. Moreover, discharge current inversely affects the fatigue life, and this influence is highly pronounced at lower stresses. The EDMed surfaces are characterized by surface properties that could be responsible for change in fatigue life such as surface morphology, surface roughness, white layer thickness, microhardness and residual stresses. It is found that all these surface properties are affected by changing discharge current level. However, change in fatigue life by discharge current could not be associated independently to any single surface property.

  17. Effect of microarc discharge surface treatment on the tensile properties of Al-Cu-Mg alloy

    International Nuclear Information System (INIS)

    Xue, Wenbin; Wang, Chao; Deng, Zhiwei; Chen, Ruyi; Zhang, Tonghe; Li, Yongliang

    2002-01-01

    A thick ceramic coating was prepared on Al-Cu-Mg alloy by microarc discharge in aqueous solution. The tensile properties of the alloy before and after microarc oxidation (MAO) surface treatment were tested, then the fractography and morphology of ceramic oxide coatings were investigated using scanning electron microscope (SEM). It is shown that the tensile properties of aluminum alloy have smaller change after the alloy has undergone microarc discharge treatment. For all specimens with different thickness coatings, the decreases of yield strength, tensile strength and elastic modulus are less than 5%, and the contraction of area rises while the elongation slightly decreases. After the coatings are polished, the tensile properties of the alloy are improved rather small. The surface of tensile specimens uniformly remains a large quantity of tiny fragments of alumina coatings. That implies that the ceramic coating has good adhesion with aluminum alloy substrate

  18. A study of direct-current surface discharge plasma for a Mach 3 supersonic flow control

    Science.gov (United States)

    Shin, Jichul

    A direct-current, non-equilibrium surface glow discharge plasma in the presence of a Mach 2.85 flow is studied experimentally for flow control applications. The discharge is generated with pin-like electrodes flush mounted on a ceramic plate with sustaining currents from 25 mA to 300 mA. In the presence of a supersonic flow, two distinct discharge modes - diffuse and constricted - are observed depending on the flow and discharge operating conditions. In cathode upstream location, both diffuse and constricted discharges are observed while in cathode downstream location, the discharge mostly exhibits either constricted mode or bistable mixed mode. The effect of the discharge on the flow ("plasma actuation'') is characterized by the appearance of a weak shock wave in the vicinity of the discharge. The shock is observed at low powers (˜10 W) for the diffuse discharge mode but is absent for the higher power (˜100 W) constricted mode. High speed laser schlieren imaging suggests that the diffuse mode plasma actuation is rapid as it occurs on a time scale that is less than 100 microsec. Rotational (gas) and vibrational temperatures within the discharge are estimated by emission spectral line fits of N 2 and N+2 rovibronic bands near 365-395 nm. The electronic temperatures are estimated by using the Boltzmann plot method for Fe(I) atomic lines. Rotational temperatures are found to be high (˜1500 K) in the absence of a flow but drop sharply (˜500 K) in the presence of a supersonic flow for both the diffuse and constricted discharge modes. The vibrational and electronic temperatures are measured to be about 3000 K and 1.25 eV (14500 K), respectively, and these temperatures are the same with and without flow. The gas (rotational) temperature spatial profiles above the cathode surface are found to be similar for the diffuse and constricted modes indicating that dilatational effects due to gas heating are similar. However, complete absence of flow actuation for the

  19. Electric field measurements in nanosecond pulse discharges in air over liquid water surface

    Science.gov (United States)

    Simeni Simeni, Marien; Baratte, Edmond; Zhang, Cheng; Frederickson, Kraig; Adamovich, Igor V.

    2018-01-01

    Electric field in nanosecond pulse discharges in ambient air is measured by picosecond four-wave mixing, with absolute calibration by a known electrostatic field. The measurements are done in two geometries, (a) the discharge between two parallel cylinder electrodes placed inside quartz tubes, and (b) the discharge between a razor edge electrode and distilled water surface. In the first case, breakdown field exceeds DC breakdown threshold by approximately a factor of four, 140 ± 10 kV cm-1. In the second case, electric field is measured for both positive and negative pulse polarities, with pulse durations of ˜10 ns and ˜100 ns, respectively. In the short duration, positive polarity pulse, breakdown occurs at 85 kV cm-1, after which the electric field decreases over several ns due to charge separation in the plasma, with no field reversal detected when the applied voltage is reduced. In a long duration, negative polarity pulse, breakdown occurs at a lower electric field, 30 kV cm-1, after which the field decays over several tens of ns and reverses direction when the applied voltage is reduced at the end of the pulse. For both pulse polarities, electric field after the pulse decays on a microsecond time scale, due to residual surface charge neutralization by transport of opposite polarity charges from the plasma. Measurements 1 mm away from the discharge center plane, ˜100 μm from the water surface, show that during the voltage rise, horizontal field component (Ex ) lags in time behind the vertical component (Ey ). After breakdown, Ey is reduced to near zero and reverses direction. Further away from the water surface (≈0.9 mm), Ex is much higher compared to Ey during the entire voltage pulse. The results provide insight into air plasma kinetics and charge transport processes near plasma-liquid interface, over a wide range of time scales.

  20. Ozone production using a power modulated surface dielectric barrier discharge in dry synthetic air

    Czech Academy of Sciences Publication Activity Database

    Šimek, Milan; Pekárek, S.; Prukner, Václav

    2012-01-01

    Roč. 32, č. 4 (2012), s. 743-754 ISSN 0272-4324 R&D Projects: GA ČR(CZ) GA202/09/0176 Institutional research plan: CEZ:AV0Z20430508 Keywords : ozone * surface DBD * synthetic air * nitrogen oxides * production efficiency Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 1.728, year: 2012 http://www.springerlink.com/content/h7p1j46381150510/fulltext. pdf

  1. Surface modification of PET films using dielectric barrier discharge driven by repetitive nanosecond-pulses

    International Nuclear Information System (INIS)

    Shao Tao; Zhang Cheng; Long Kaihua; Wang Jue; Zhang Dongdong; Yan Ping; Zhou Yuanxiang

    2010-01-01

    In this paper, surface treatment of PET films for improving the hydrophilicity using DBD excited by unipolar nanosecond-pulses is presented. Homogeneous and filamentary discharge are obtained under certain experimental conditions and then used to modify the surface of PET films. The properties of PET films before and after treatment are characterized with water contact angle measurement, atomic force microscope and X-ray photoelectron spectroscope. The experimental results show that static water contact angles decrease after DBD plasma treatment and the observed contact angle is changed from 80 degree for the untreated samples to 20 degree after treatment. However, the decrease of contact angles is not continuous and it will reach a saturation state after certain treatment time. The improvement of surface hydrophilicity can be attributed to the enhancement of the surface roughness and introduction of oxygen-containing polar functional groups. In contrast with the filamentary DBD treatment, the homogenous DBD is more effective in PET surface treatment. (authors)

  2. Influence of Wire Electrical Discharge Machining (WEDM) process parameters on surface roughness

    Science.gov (United States)

    Yeakub Ali, Mohammad; Banu, Asfana; Abu Bakar, Mazilah

    2018-01-01

    In obtaining the best quality of engineering components, the quality of machined parts surface plays an important role. It improves the fatigue strength, wear resistance, and corrosion of workpiece. This paper investigates the effects of wire electrical discharge machining (WEDM) process parameters on surface roughness of stainless steel using distilled water as dielectric fluid and brass wire as tool electrode. The parameters selected are voltage open, wire speed, wire tension, voltage gap, and off time. Empirical model was developed for the estimation of surface roughness. The analysis revealed that off time has a major influence on surface roughness. The optimum machining parameters for minimum surface roughness were found to be at a 10 V open voltage, 2.84 μs off time, 12 m/min wire speed, 6.3 N wire tension, and 54.91 V voltage gap.

  3. Microscopic degradation mechanism of polyimide film caused by surface discharge under bipolar continuous square impulse voltage

    Science.gov (United States)

    Luo, Yang; Wu, Guang-Ning; Liu, Ji-Wu; Peng, Jia; Gao, Guo-Qiang; Zhu, Guang-Ya; Wang, Peng; Cao, Kai-Jiang

    2014-02-01

    Polyimide (PI) film is an important type of insulating material used in inverter-fed motors. Partial discharge (PD) under a sequence of high-frequency square impulses is one of the key factors that lead to premature failures in insulation systems of inverter-fed motors. In order to explore the damage mechanism of PI film caused by discharge, an aging system of surface discharge under bipolar continuous square impulse voltage (BCSIV) is designed based on the ASTM 2275 01 standard and the electrical aging tests of PI film samples are performed above the partial discharge inception voltage (PDIV). The chemical bonds of PI polymer chains are analyzed through Fourier transform infrared spectroscopy (FTIR) and the dielectric properties of unaged and aged PI samples are investigated by LCR testers HIOKI 3532-50. Finally, the micro-morphology and micro-structure changes of PI film samples are observed through scanning electron microscopy (SEM). The results show that the physical and chemical effects of discharge cut off the chemical bonds of PI polymer chains. The fractures of ether bond (C—O—C) and imide ring (C—N—C) on the backbone of a PI polymer chain leads to the decrease of molecular weight, which results in the degradation of PI polymers and the generation of new chemical groups and materials, like carboxylic acid, ketone, aldehydes, etc. The variation of microscopic structure of PI polymers can change the orientation ability of polarizable units when the samples are under an AC electric field, which would cause the dielectric constant ɛ to increase and dielectric loss tan δ to decrease. The SEM images show that the degradation path of PI film is initiated from the surface and then gradually extends to the interior with continuous aging. The injection charge could result in the PI macromolecular chain degradation and increase the trap density in the PI polymer bulk.

  4. Improving Hydrophobicity of Glass Surface Using Dielectric Barrier Discharge Treatment in Atmospheric Air

    International Nuclear Information System (INIS)

    Fang Zhi; Qiu Yuchang; Wang Hui; Kuffel, E

    2007-01-01

    Non-thermal plasmas under atmospheric pressure are of great interest in industrial applications, especially in material surface treatment. In this paper, the treatment of a glass surface for improving hydrophobicity using the non-thermal plasma generated by dielectric barrier discharge (DBD) at atmospheric pressure in ambient air is conducted, and the surface properties of the glass before and after the DBD treatment are studied by using contact angle measurement, surface resistance measurement and wet flashover voltage tests. The effects of the applied voltage and time duration of DBD on the surface modification are studied, and the optimal conditions for the treatment are obtained. It is found that a layer of hydrophobic coating is formed on the glass surface after spraying a thin layer of silicone oil and undergoing the DBD treatment, and the improvement of hydrophobicity depends on DBD voltage and treating time. It seems that there exists an optimum treating time for a certain applied voltage of DBD during the surface treatment. The test results of thermal aging and chemical aging show that the hydrophobic layer has quite stable characteristics. The interaction mechanism between the DBD plasma and the glass surface is discussed. It is concluded that CH 3 and large molecule radicals can react with the radicals in the glass surface to replace OH, and the hydrophobicity of the glass surface is improved accordingly

  5. Surface treatment of aramid fiber by air dielectric barrier discharge plasma at atmospheric pressure

    International Nuclear Information System (INIS)

    Jia Caixia; Chen Ping; Liu Wei; Li Bin; Wang Qian

    2011-01-01

    Aramid fiber samples are treated by air dielectric barrier discharge (DBD) plasma at atmospheric pressure; the plasma treatment time is investigated as the major parameter. The effects of this treatment on the fiber surface physical and chemical properties are studied by using surface characterization techniques. Scanning electron microscopy (SEM) is performed to determine the surface morphology changes, X-ray photoelectron spectroscopy (XPS) is analyzed to reveal the surface chemical composition variations and dynamic contact angle analysis (DCAA) is used to examine the changes of the fiber surface wettability. In addition, the wetting behavior of a kind of thermoplastic resin, poly(phthalazinone ether sulfone ketone) (PPESK), on aramid fiber surface is also observed by SEM photos. The study shows that there seems to be an optimum treatment condition for surface modification of aramid fiber by the air DBD plasma. In this paper, after the 12 s, 27.6 W/cm 3 plasma treatment the aramid fiber surface roughness is significantly improved, some new oxygen-containing groups such as C-O, C=O and O=C-O are generated on the fiber surface and the fiber surface wettability is greatly enhanced, which results in the better wetting behavior of PPESK resin on the plasma-treated aramid fiber.

  6. Surface and elemental alterations of dental alloys induced by electro discharge machining (EDM).

    Science.gov (United States)

    Zinelis, Spiros

    2007-05-01

    To evaluate the surface and elemental alterations induced by electro discharge machining (EDM) on the surface of dental cast alloys used for the fabrication of implant retained meso- and super-structures. A completed cast model of an arch that received dental implants was used for the preparation of six wax patterns which were divided into three groups (Au, Co and Ti). The wax patterns of the Au and Co groups were invested with conventional phosphate-bonded silica-based investment material and the Ti group with magnesia-based investment material. The investment rings of the Au and Co groups were cast with an Au-Ag alloy (Stabilor G) and a Co-Cr base alloy (Okta C), respectively, while the investment rings of group Ti were cast with cp Ti (Biotan). One casting of each group was subjected to electro discharge machining (EDM); the other was conventionally ground and polished. The surface morphology and the elemental compositions of conventionally and EDM-finished surfaces were studied by SEM/X-ray EDS analysis. Six spectra were collected from each surface employing the area scan mode and the mean value of each element between conventionally and EDM-finished surfaces was statistically analyzed by t-test (a=0.05). Then the specimens of each group were cut perpendicular to their longitudinal axis and after metallographic grinding and polishing the cross-sections studied under the SEM. The EDM surfaces showed a significant increase in C due to the decomposition of the dielectric fluid during spark erosion. Moreover, a significant Cu uptake was noted on these surfaces from the decomposition of the Cu electrodes used for EDM. Cross-sectional analysis showed that all alloys developed a superficial zone (recast layer) varying from 2 microm for Au-Ag to 10 microm for Co-Cr alloy. The elemental composition of dental alloy surfaces is significantly altered after EDM treatment.

  7. Lamps and lighting

    CERN Document Server

    Cayless, MA; Marsden, A M

    2012-01-01

    This book is a comprehensive guide to the theory and practice of lighting. Covering the physics of light production, light sources, circuits and a wide variety of lighting applications, it is both suitable as a detailed textbook and as thoroughly practical guide for practising lighting engineers. This fourth edition of Lamps and Lighting has been completely updated with new chapters on the latest lamp technology and applications. The editors ahve called upon a wide range of expertise and as a result many sections have been broadened to include both European and US practice.The book begins with

  8. The influence of spherical cavity surface charge distribution on the sequence of partial discharge events

    Energy Technology Data Exchange (ETDEWEB)

    Illias, Hazlee A [Department of Electrical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur (Malaysia); Chen, George; Lewin, Paul L, E-mail: h.illias@um.edu.my [Tony Davies High Voltage Laboratory, School of Electronics and Computer Science, University of Southampton, Southampton, SO17 1BJ (United Kingdom)

    2011-06-22

    In this work, a model representing partial discharge (PD) behaviour of a spherical cavity within a homogeneous dielectric material has been developed to study the influence of cavity surface charge distribution on the electric field distribution in both the cavity and the material itself. The charge accumulation on the cavity surface after a PD event and charge movement along the cavity wall under the influence of electric field magnitude and direction has been found to affect the electric field distribution in the whole cavity and in the material. This in turn affects the likelihood of any subsequent PD activity in the cavity and the whole sequence of PD events. The model parameters influencing cavity surface charge distribution can be readily identified; they are the cavity surface conductivity, the inception field and the extinction field. Comparison of measurement and simulation results has been undertaken to validate the model.

  9. Effects of air dielectric barrier discharge plasma treatment time on surface properties of PBO fiber

    International Nuclear Information System (INIS)

    Wang Qian; Chen Ping; Jia Caixia; Chen, Mingxin; Li Bin

    2011-01-01

    In this paper, the effects of air dielectric barrier discharge (DBD) plasma treatment time on surface properties of poly(p-phenylene benzobisoxazole) (PBO) fiber were investigated. The surface characteristics of PBO fiber before and after the plasma treatments were analyzed by dynamic contact angle (DCA) analysis, scanning electron microscopy (SEM), atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). DCA measurements indicated that the surface wettability of PBO fiber was improved significantly by increasing the fiber surface free energy via air DBD plasma treatments. The results were confirmed by the improvement of adhesion of a kind of thermoplastic resin to PBO fiber which was observed by SEM, showing that more resin was adhering evenly to the fiber surface. AFM measurement revealed that the surface topography of PBO fiber became more complicated and the surface roughness was greatly enhanced after the plasma treatments, and XPS analysis showed that some new polar groups (e.g. -O-C=O) were introduced on plasma treated PBO fiber surface. The results of this study also showed that the surface properties of PBO fiber changed with the elongation of plasma treatment time.

  10. Max Tech and Beyond: Fluorescent Lamps

    Energy Technology Data Exchange (ETDEWEB)

    Scholand, Michael

    2012-04-01

    Fluorescent lamps are the most widely used artificial light source today, responsible for approximately 70% of the lumens delivered to our living spaces globally. The technology was originally commercialized in the 1930's, and manufacturers have been steadily improving the efficacy of these lamps over the years through modifications to the phosphors, cathodes, fill-gas, operating frequency, tube diameter and other design attributes. The most efficient commercially available fluorescent lamp is the 25 Watt T5 lamp. This lamp operates at 114-116 lumens per watt while also providing good color rendering and more than 20,000 hours of operating life. Industry experts interviewed indicated that while this lamp is the most efficient in the market today, there is still a further 10 to 14% of potential improvements that may be introduced to the market over the next 2 to 5 years. These improvements include further developments in phosphors, fill-gas, cathode coatings and ultraviolet (UV) reflective glass coatings. The commercialization of these technology improvements will combine to bring about efficacy improvements that will push the technology up to a maximum 125 to 130 lumens per watt. One critical issue raised by researchers that may present a barrier to the realization of these improvements is the fact that technology investment in fluorescent lamps is being reduced in order to prioritize research into light emitting diodes (LEDs) and ceramic metal halide high intensity discharge (HID) lamps. Thus, it is uncertain whether these potential efficacy improvements will be developed, patented and commercialized. The emphasis for premium efficacy will continue to focus on T5 lamps, which are expected to continue to be marketed along with the T8 lamp. Industry experts highlighted the fact that an advantage of the T5 lamp is the fact that it is 40% smaller and yet provides an equivalent lumen output to that of a T8 or T12 lamp. Due to its smaller form factor, the T5 lamp

  11. Plasma surface treatment of Cu by nanosecond-pulse diffuse discharges in atmospheric air

    Science.gov (United States)

    Cheng, ZHANG; Jintao, QIU; Fei, KONG; Xingmin, HOU; Zhi, FANG; Yu, YIN; Tao, SHAO

    2018-01-01

    Nanosecond-pulse diffuse discharges could provide high-density plasma and high-energy electrons at atmospheric pressure. In this paper, the surface treatment of Cu by nanosecond-pulse diffuse discharges is conducted in atmospheric air. Factors influencing the water contact angle (WCA), chemical composition and microhardness, such as the gap spacing and treatment time, are investigated. The results show that after the plasma surface treatment, the WCA considerably decreases from 87° to 42.3°, and the surface energy increases from 20.46 mJ m-2 to 66.28 mJ m-2. Results of energy dispersive x-ray analysis show that the concentration of carbon decreases, but the concentrations of oxygen and nitrogen increase significantly. Moreover, the microhardness increases by approximately 30% after the plasma treatment. The aforementioned changes on the Cu surface indicate the plasma surface treatment enhances the hydrophilicity and microhardness, and it cleans the carbon and achieves oxidization on the Cu surface. Furthermore, by increasing the gap spacing and treatment time, better treatment effects can be obtained. The microhardness in the case of a 2.5 cm gap is higher than that in the case of a 3 cm gap. More oxygen and nitrogen species appear on the Cu surface for the 2.5 cm gap treatment than for the 3 cm gap treatment. The WCA significantly decreases with the treatment time when it is no longer than 90 s, and then it reaches saturation. In addition, more oxygen-containing and nitrogen-containing groups appear after extended plasma treatment time. They contribute to the improvement of the hydrophilicity and oxidation on the Cu surface.

  12. Stress response of Escherichia coli induced by surface streamer discharge in humid air

    Science.gov (United States)

    Doležalová, Eva; Prukner, Václav; Lukeš, Petr; Šimek, Milan

    2016-02-01

    Inactivation of Escherichia coli by means of surface streamer discharge has been investigated to obtain new insights into the key mechanisms involved, with a particular emphasis placed on the microbial response to plasma-induced stress. The surface streamer discharge was produced in coplanar dielectric barrier discharge electrode geometry, and was driven by an amplitude-modulated ac high voltage in humid synthetic air at atmospheric pressure. The response to plasma-induced stress was evaluated by using conventional cultivation, sublethal injury and resazurin assay and the LIVE/DEAD® BacLight™ Bacterial Viability kit. Compared to conventional cultivation, the LIVE/DEAD® test labels bacteria with damaged membranes, while resazurin assay tracks their metabolic activity. Our results clearly demonstrate that the treated bacteria partly lost their ability to grow properly, i.e. they became injured and culturable, or even viable but nonculturable (VBNC). The ability to develop colonies could have been lost due to damage of the bacterial membrane. Damage of the membranes was mainly caused by the lipid peroxidation, evidencing the key role of oxygen reactive species, in particular ozone. We conclude that the conventional cultivation method overestimates the decontamination efficiency of various plasma sources, and must therefore be complemented by alternative techniques capable of resolving viable but nonculturable bacteria.

  13. Quantitative measurements of ground state atomic oxygen in atmospheric pressure surface micro-discharge array

    Science.gov (United States)

    Li, D.; Kong, M. G.; Britun, N.; Snyders, R.; Leys, C.; Nikiforov, A.

    2017-06-01

    The generation of atomic oxygen in an array of surface micro-discharge, working in atmospheric pressure He/O2 or Ar/O2 mixtures, is investigated. The absolute atomic oxygen density and its temporal and spatial dynamics are studied by means of two-photon absorption laser-induced fluorescence. A high density of atomic oxygen is detected in the He/O2 mixture with up to 10% O2 content in the feed gas, whereas the atomic oxygen concentration in the Ar/O2 mixture stays below the detection limit of 1013 cm-3. The measured O density near the electrode under the optimal conditions in He/1.75% O2 gas is 4.26  ×  1015 cm-3. The existence of the ground state O (2p 4 3 P) species has been proven in the discharge at a distance up to 12 mm away from the electrodes. Dissociative reactions of the singlet O2 with O3 and deep vacuum ultraviolet radiation, including the radiation of excimer \\text{He}2\\ast , are proposed to be responsible for O (2p 4 3 P) production in the far afterglow. A capability of the surface micro-discharge array delivering atomic oxygen to long distances over a large area is considered very interesting for various biomedical applications.

  14. Humidity effects on surface dielectric barrier discharge for gaseous naphthalene decomposition

    Science.gov (United States)

    Abdelaziz, Ayman A.; Ishijima, Tatsuo; Seto, Takafumi

    2018-04-01

    Experiments are performed using dry and humid air to clarify the effects of water vapour on the characteristics of surface dielectric barrier discharge (SDBD) and investigate its impact on the performance of the SDBD for decomposition of gaseous naphthalene in air stream. The current characteristics, including the discharge and the capacitive currents, are deeply analyzed and the discharge mechanism is explored. The results confirmed that the humidity affected the microdischarge distribution without affecting the discharge mode. Interestingly, it is found that the water vapour had a significant influence on the capacitance of the reactor due to its deposition on the discharge electrode and the dielectric, which, in turn, affects the power loss in the dielectric and the total power consumed in the reactor. Thus, the factor of the humidity effect on the power loss in the dielectric should be considered in addition to its effect on the attachment coefficient. Additionally, there was an optimum level of the humidity for the decomposition of naphthalene in the SDBD, and its value depended on the gas composition, where the maximum naphthalene decomposition efficiency in O2/H2O is achieved at the humidity level ˜10%, which was lower than that obtained in air/H2O (˜28%). The results also revealed that the role of the humidity in the decomposition efficiency was not significant in the humidified O2 at high power level. This was attributed to the significant increase in oxygen-derived species (such as O atoms and O3) at high power, which was enough to overcome the negative effects of the humidity.

  15. Determination of HID electrode falls in a model lamp I: Pyrometric measurements

    International Nuclear Information System (INIS)

    Dabringhausen, L.; Nandelstaedt, D.; Luhmann, J.; Mentel, J.

    2002-01-01

    To verify models describing the near-electrode regions electrodes of pure and doped tungsten for high intensity discharge lamps are investigated in a special model lamp. It can be operated with arc currents of 1 A to 10 A, DC or AC with arbitrary waveforms up to a few kHz. Argon and xenon, at pressures from 0.1 MPa to 1 MPa, are used as fill gases. A large variety of electrodes can be inserted. To perform spatially resolved measurements they are displaced reproducibly within the discharge tube during lamp operation. Spatially resolved pyrometric measurements of the electrode surface temperature in the case of DC operation are presented. From the temperature distribution the power loss of the electrodes by thermal radiation and heat conduction is determined. It increases almost linearly with the arc current at the anode and less than linear at the cathode. A relation is deduced between the cathode fall and the power fed into the cathode setting up the power balance of the cathodic current transfer zone. The resulting cathode falls show a strong dependence on the electrode diameter. Electrical measurements of separate cathode and anode falls are given in a subsequent paper. The outcomes of both methods and of modelling are compared in a third paper. (author)

  16. Implication of discharge pattern of radionuclides in the landscape on surface hydrological pathways and residence times

    International Nuclear Information System (INIS)

    Anders Woerman; Lars Marklund; Xu Shulan; Bjoern Dverstorp

    2005-01-01

    The safety analysis of the final repository of spent nuclear fuel will include large-scale migration behaviour of radionuclides that accidentally leak from the repository in deep bedrock. Physically based models of radionuclides release-processes would typically take into account the flow and transport in the hydrosphere as well as spreading through ecosystems to individual humans. This study addresses the coupling between discharge pattern in the landscape and factors controlling the residence times or radionuclides in the biosphere on land. The overall residence time on land is crucial because it controls the maximum exposure of radioactivity to individual humans. Numerical analysis indicate that variation in topography and quaternary deposits affect the discharge pattern in the landscape for radionuclides that escapes the waste repository in deep bedrock. Those analyses are based on extensive geographical data covering surface topography, stream network characteristics and geological structure on the continental scale of Scandinavia. Results on the discharge pattern in three typical Swedish landscapes are used as a basis for comparative analyses of the residence time distribution in surface hydrological systems for radionuclides that escape the waste repository. The groundwater flow analyses show that pathways of deep groundwater predominantly lead to the stream network, but to some extent also to lakes, wetlands and root uptake. The proportion varies slightly with altitude in the watershed as well as between different watersheds. The residence times in the stream network was based on convoluting the residence times for single discharge points over the entire stream network according to the technique of and data on stream distance distribution. The retardation due to uptake in the hyporheic zone was accounted for using the methods of and estimated sorption properties for Cs-137. The residence time for radionuclides in the hydrological systems of the continent

  17. Breakdown characteristics of xenon HID Lamps

    Science.gov (United States)

    Babaeva, Natalia; Sato, Ayumu; Brates, Nanu; Noro, Koji; Kushner, Mark

    2009-10-01

    The breakdown characteristics of mercury free xenon high intensity discharge (HID) lamps exhibit a large statistical time lag often having a large scatter in breakdown voltages. In this paper, we report on results from a computational investigation of the processes which determine the ignition voltages for positive and negative pulses in commercial HID lamps having fill pressures of up to 20 atm. Steep voltage rise results in higher avalanche electron densities and earlier breakdown times. Circuit characteristics also play a role. Large ballast resistors may limit current to the degree that breakdown is quenched. The breakdown voltage critically depends on cathode charge injection by electric field emission (or other mechanisms) which in large part controls the statistical time lag for breakdown. For symmetric lamps, ionization waves (IWs) simultaneously develop from the bottom and top electrodes. Breakdown typically occurs when the top and bottom IWs converge. Condensed salt layers having small conductivities on the inner walls of HID lamps and on the electrodes can influence the ignition behavior. With these layers, IWs tend to propagate along the inner wall and exhibit a different structure depending on the polarity.

  18. Surface enrichment with chrome and nitriding of IF steel under an abnormal glow discharge

    International Nuclear Information System (INIS)

    Meira, S.R.; Borges, P.C.; Bernardelli, E.A.

    2014-01-01

    The objective of this work is to evaluate the influence of surface enrichment of IF steel with chrome, and nitriding, the formation of the nitrided layer. Thus, IF steel samples were subjected to surface enrichment process, using 409 stainless steel as a target for sputtering, followed by plasma nitriding, both under a dc abnormal glow discharge. The enrichment treatment was operated at 1200 ° C for 3h. The nitriding treatment was operated at 510 ° C for 2 h. The influence of the treatments on the layers formed was studied through optical microscopy (OM), scan electron microscopy (SEM), X-ray diffraction (XRD) and Vickers microindentation. The results show that the enrichment is effective to enrich the IF surface, furthermore, improves the characteristics of nitriding, comparing nitriding samples to nitriding and enriched, was observed needles of nitrides, as well as a higher hardness, which is associated with the nitrides of chrome, on the nitriding and enriched samples. (author)

  19. Surface modification of polyimide (PI) film using water cathode atmospheric pressure glow discharge plasma

    International Nuclear Information System (INIS)

    Zheng Peichao; Liu Keming; Wang Jinmei; Dai Yu; Yu Bin; Zhou Xianju; Hao Honggang; Luo Yuan

    2012-01-01

    Highlights: ► Equipment called water cathode atmospheric pressure glow discharge was used to improve the hydrophilicity of polyimide films. ► The data shows good homogeneity and the variation trends of contact angles are different for polar and non-polar testing liquids. ► The thickness of liquid layer plays an important role in plasma processing and directly affects the treatment effect. ► Surface hydrophilicity after plasma treatment is improved partly due to the increase in the roughness. ► The hydrophilicity of polyimide films is still better than untreated ones after long-term storage. - Abstract: The industrial use of polyimide film is limited because of undesirable properties such as poor wettability. In the present paper, a new kind of equipment called water cathode atmospheric pressure glow discharge was used to improve the surface properties of polyimide films and made them useful to technical applications. The changes in hydrophilicity of modified polyimide film surfaces were investigated by contact angle, surface energy and water content measurements as a function of treatment time. The results obtained show good treatment homogeneity and that the variation trends of contact angles are different for polar and non-polar testing liquids, while surface energy and water content are significantly enhanced with the increase of treatment time until they achieve saturated values after 60 s plasma treatment. Also, the thickness of liquid layer plays an important role in plasma processing and directly affects the treatment effect. Changes in morphology of polyimide films were analyzed by atomic force microscope and the results indicate that surface hydrophilicity after plasma treatment are improved partly due to the increase in the roughness. In addition, polyimide films treated by plasma are subjected to an ageing process to determine the durability of plasma treatment. It is found that the hydrophilicity is still better than untreated ones though the

  20. Application of Radio-Frequency Plasma Glow Discharge to Removal of Uranium Dioxide from Metal Surfaces

    International Nuclear Information System (INIS)

    El-Genk, Mohamed S.; Saber, Hamed H.

    2000-01-01

    Recent experiments have shown that radio-frequency (rf) plasma glow discharge using NF 3 gas is an effective technique for the removal of uranium oxide from metal surfaces. The results of these experiments are analyzed to explain the measured dependence of the UO 2 removal or etch rate on the NF 3 gas pressure and the absorbed power in the plasma. The NF 3 gas pressure in the experiments was varied from 10.8 to 40 Pa, and the deposited power in the plasma was varied from 25 to 210 W. The UO 2 etch rate was strongly dependent on the absorbed power and, to a lesser extent, on the NF 3 pressure and decreased exponentially with immersion time. At 210 W and 17 Pa, all detectable UO 2 in the samples (∼10.6 mg each) was removed at the endpoint, whereas the initial etch rate was ∼3.11 μm/min. When the absorbed power was ≤50 W, however, the etch rate was initially ∼0.5 μg/min and almost zero at the endpoint, with UO 2 only partially etched. This self-limiting etching of UO 2 at low power is attributed to the formation of nonvolatile intermediates UF 2 , UF 3 , UF 4 , UF 5 , UO 2 F, and UO 2 F 2 on the surface. Analysis indicated that the accumulation of UF 6 and, to a lesser extent, O 2 near the surface partially contributed to the exponential decrease in the UO 2 etch rate with immersion time. Unlike fluorination with F 2 gas, etching of UO 2 using rf glow discharge is possible below 663 K. The average etch rates of the amorphous UO 2 in the NF 3 experiments are comparable to the peak values reported in other studies for crystalline UO 2 using CF 4 /O 2 glow discharge performed at ∼150 to 250 K higher sample temperatures

  1. Uniformity analysis of dielectric barrier discharge (DBD) processed polyethylene terephthalate (PET) surface

    Science.gov (United States)

    Liu, Chaozong; Brown, Norman M. D.; Meenan, Brian J.

    2006-01-01

    A dielectric barrier discharge (DBD) plasma, operating in air at atmospheric pressure, has been used to induce changes in the surface properties of polyethylene terephthalate (PET) films. The effects that the key DBD operating parameters: discharge power, processing speed, processing duration, and electrode configurations, have on producing wettability changes in the PET surface region have been investigated. The approach taken involves the application of an Taguchi experimental design and robust analysis methodology. The various data sets obtained from these analyses have been used to studies the effect of the operating parameters on the surface uniformity and efficiency of the said treatment. In general, the results obtained indicate that DBD plasma processing is an effective method for the controlled surface modification of PET. Relatively short exposures to the atmospheric pressure discharge produces significant wettability changes at the polymer film surface, as indicted by pronounced reductions in the water contact angle measured. It was observed that the wettability of the resultant surface shows no significant differences in respect to orientation parallel (L-direction) or perpendicular (T-direction) to the electrode long axis. However, there was significant differences between the data obtained from these two orientations. Analysis of the role of each of the operating parameters concerned shows that they have a selective effectiveness with respect to resultant surface modification in terms of uniformity of modification and wettability. The number of treatment cycles and the electrode configuration used were found to have the most significant effects on the homogeneity of the resultant PET surface changes in L- and T-orientation, respectively. On the other hand, the applied power showed no significant role in this regard. The number of treatment cycles was found to be the dominant factor (at significance level of 0.05) in respect of water contact angle

  2. Impact of lamp shadowing and reflection on the fluence rate distribution in a multiple low-pressure UV lamp array.

    Science.gov (United States)

    Jin, Shanshan; Linden, Karl G; Ducoste, Joel; Liu, Dong

    2005-07-01

    Use of mathematical modeling for determination of ultraviolet (UV) fluence in disinfection reactors requires accurate knowledge of the fluence rate distribution in a multiple lamp array. A method for measuring the fluence rate among a multiple lamp array was demonstrated using spherical actinometry. A matrix of four low-pressure UV lamps in air were investigated to evaluate the potential for shadowing and reflection to impact the fluence rate within and surrounding the lamp array. Two fluence rate distribution models were tested to determine the ability to predict the fluence rate distribution measured by the actinometers. Shadowing proved to attenuate UV light. Reflection from the lamp surface added 3-9% to the fluence rate, depending upon position in the reactor. These effects, as well as the fluence rate at various points in the lamp matrix were effectively modeled using RAD-LSI and UVCalc3D fluence rate distribution models. At fluence rates above 8mWcm(-2), the actinometry measured fluence rate was lower than the modeled rate, presumably from saturation of the actinometer solution at high fluence rates (close to the lamp). With multiple lamp reactors, the impact of shadowing can significantly affect fluence rate distribution and thus the level of microbial inactivation. If shadowing is not included in fluence rate distribution models, the fluence rate will be over predicted in the shadow zone of a neighboring lamp, falsely skewing model inactivation predictions.

  3. Silicon Carbide Semiconductor Surface Dielectric Barrier Discharge (SSDBD) Device for Turbulent Skin Friction Drag Reduction and Flow Control Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed research effort explores the use of a nanosecond pulse driven offset semiconducting surface dielectric barrier discharge (SSDBD) device for the control...

  4. Ozone kinetics in low-pressure discharges: vibrationally excited ozone and molecule formation on surfaces

    International Nuclear Information System (INIS)

    Marinov, Daniil; Guaitella, Olivier; Booth, Jean-Paul; Rousseau, Antoine; Guerra, Vasco

    2013-01-01

    A combined experimental and modeling investigation of the ozone kinetics in the afterglow of pulsed direct current discharges in oxygen is carried out. The discharge is generated in a cylindrical silica tube of radius 1 cm, with short pulse durations between 0.5 and 2 ms, pressures in the range 1–5 Torr and discharge currents ∼40–120 mA. Time-resolved absolute concentrations of ground-state atoms and ozone molecules were measured simultaneously in situ, by two-photon absorption laser-induced fluorescence and ultraviolet absorption, respectively. The experiments were complemented by a self-consistent model developed to interpret the results and, in particular, to evaluate the roles of vibrationally excited ozone and of ozone formation on surfaces. It is found that vibrationally excited ozone, O 3 * , plays an important role in the ozone kinetics, leading to a decrease in the ozone concentration and an increase in its formation time. In turn, the kinetics of O 3 * is strongly coupled with those of atomic oxygen and O 2 (a 1 Δ g ) metastables. Ozone formation at the wall does not contribute significantly to the total ozone production under the present conditions. Upper limits for the effective heterogeneous recombination probability of O atoms into ozone are established. (paper)

  5. Ozone kinetics in low-pressure discharges: vibrationally excited ozone and molecule formation on surfaces

    Science.gov (United States)

    Marinov, Daniil; Guerra, Vasco; Guaitella, Olivier; Booth, Jean-Paul; Rousseau, Antoine

    2013-10-01

    A combined experimental and modeling investigation of the ozone kinetics in the afterglow of pulsed direct current discharges in oxygen is carried out. The discharge is generated in a cylindrical silica tube of radius 1 cm, with short pulse durations between 0.5 and 2 ms, pressures in the range 1-5 Torr and discharge currents ˜40-120 mA. Time-resolved absolute concentrations of ground-state atoms and ozone molecules were measured simultaneously in situ, by two-photon absorption laser-induced fluorescence and ultraviolet absorption, respectively. The experiments were complemented by a self-consistent model developed to interpret the results and, in particular, to evaluate the roles of vibrationally excited ozone and of ozone formation on surfaces. It is found that vibrationally excited ozone, O_3^{*} , plays an important role in the ozone kinetics, leading to a decrease in the ozone concentration and an increase in its formation time. In turn, the kinetics of O_3^{*} is strongly coupled with those of atomic oxygen and O2(a 1Δg) metastables. Ozone formation at the wall does not contribute significantly to the total ozone production under the present conditions. Upper limits for the effective heterogeneous recombination probability of O atoms into ozone are established.

  6. Investigations on the influence of pressure, current and electrode gap in high-pressure mercury lamps

    International Nuclear Information System (INIS)

    Flesch, P; Neiger, M

    2005-01-01

    This paper is concerned with the numerical simulation of high-intensity discharge lamps, focusing on the influence of pressure, current and electrode gap on plasma, anode and cathode properties. The interaction between electrodes and plasma is taken into account. Comparisons between experimental findings and numerical results show that the observed increase in the total lamp voltage caused by an increasing lamp current is a superposition of an increasing lamp voltage due to an increasing pressure (caused by the increasing lamp current) and a decreasing lamp voltage due to the increasing lamp current (if the pressure would be constant). Furthermore, the numerical results reveal that the plasma potential in the whole plasma strongly depends on the electrode gap and that even the electrode temperature and the arc attachment to the electrodes are influenced by the size of the electrode gap

  7. Plasma Discharge Effect on Secondary Electron Yield of Various Surface Locations on SRF Cavities

    Science.gov (United States)

    Basovic, Milos; Samolov, Ana; Cuckov, Filip; Tomovic, Mileta; Popovic, Svetozar; Vuskovic, Leposava

    2015-09-01

    Electron activity (field emission and multipacting) has been identified as the main limiting factor of Superconducting Radiofrequency (SRF) cavity performance. Secondary Electron Yield (SEY) is highly dependent on the state of the cavity's surface, which is investigated before and after plasma exposure. Current methods for simulating the electron activity in SRF cavity consider it as a uniform surface. Due to fabricating procedure there are three distinct areas of the cavity's microstructure: weld zone, heat affected zone, and base metal zone. Each zone has a characteristic microstructure even after the treatments that are currently used to clean the surface of the cavities. Improvement of existing surface treatment techniques, or use of a new is required in order to increase the limit of Q factor towards the theoretical limit of Nb. RF discharge is a promising technique for this purpose. In order to test the effect of the plasma on the SEY of the various cavity surface zones we have developed the experimental setup to measure the energy distribution of the SEY from coupon-like samples. Samples are made in a way that all three zones of cavity surface will be included in the examination. We will present the SEY changes in these three zones before and after plasma treatment.

  8. Surface Treatment of Polypropylene Films Using Dielectric Barrier Discharge with Magnetic Field

    International Nuclear Information System (INIS)

    Wang Changquan; Zhang Guixin; Wang Xinxin; Chen Zhiyu

    2012-01-01

    Atmospheric pressure non-thermal plasma is of interest for industrial applications. In this study, polypropylene (PP) films are modified by a dielectric barrier discharge (DBD) with a non-uniform magnetic field in air at atmospheric pressure. The surface properties of the PP films before and after a DBD treatment are studied by using contact angle measurement, atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). The effect of treatment time on the surface modification with and without a magnetic field is investigated. It is found that the hydrophilic improvement depends on the treatment time and magnetic field. It is also found that surface roughness and oxygen-containing groups are introduced onto the PP film surface after the DBD treatment. Surface roughness and oxygen-containing polar functional groups of the PP films increase with the magnetic induction density. The functional groups are identified as C-O, C=O and O-C=O by using XPS analysis. It is concluded that the hydrophilic improvement of PP films treated with a magnetic field is due to a greater surface roughness and more oxygen-containing groups. (plasma technology)

  9. Estimating Discharge, Depth and Bottom Friction in Sand Bed Rivers Using Surface Currents and Water Surface Elevation Observations

    Science.gov (United States)

    Simeonov, J.; Czapiga, M. J.; Holland, K. T.

    2017-12-01

    We developed an inversion model for river bathymetry estimation using measurements of surface currents, water surface elevation slope and shoreline position. The inversion scheme is based on explicit velocity-depth and velocity-slope relationships derived from the along-channel momentum balance and mass conservation. The velocity-depth relationship requires the discharge value to quantitatively relate the depth to the measured velocity field. The ratio of the discharge and the bottom friction enter as a coefficient in the velocity-slope relationship and is determined by minimizing the difference between the predicted and the measured streamwise variation of the total head. Completing the inversion requires an estimate of the bulk friction, which in the case of sand bed rivers is a strong function of the size of dune bedforms. We explored the accuracy of existing and new empirical closures that relate the bulk roughness to parameters such as the median grain size diameter, ratio of shear velocity to sediment fall velocity or the Froude number. For given roughness parameterization, the inversion solution is determined iteratively since the hydraulic roughness depends on the unknown depth. We first test the new hydraulic roughness parameterization using estimates of the Manning roughness in sand bed rivers based on field measurements. The coupled inversion and roughness model is then tested using in situ and remote sensing measurements of the Kootenai River east of Bonners Ferry, ID.

  10. Unipolar charging of nanoparticles by the Surface-discharge Microplasma Aerosol Charger (SMAC)

    Science.gov (United States)

    Kwon, Soon-Bark; Sakurai, Hiromu; Seto, Takafumi

    2007-08-01

    In this paper, we report the development of a novel unipolar charger for nanoparticles, a system that achieves low particle loss and high charging efficiency without the use of sheath air. The efficient unipolar charging of the system is realized mainly by the surface-discharge microplasma unit, a device previously applied with good success to the neutralization or charging of submicron particles [Kwon et al., 2005, Aerosol Sci. Technol., 39, 987-1001; 2006, J. Aerosol Sci., 37, 483-499]. The unipolar charger generates unipolar ions using the surface discharge of a single electrode with a DC pulse supply. This marks an advance from our previous method of generating bipolar ions with the use of dual electrodes in earlier studies. We evaluated the efficiency of the penetration (or loss) and charging of nanoparticles in the size range of 3-15 nm, then compared the charging efficiencies measured with those predicted by diffusion charging theory. More than 90% of inlet nanoparticles penetrated the charger (less than 10% of the particle were lost) without the use of sheath air. Other chargers have only realized this high penetration efficiency by relying on sheath air flow. Moreover, the measured charging efficiencies agreed well with those predicted by diffusion charging theory and were somewhat higher and more size-dependent than the charging efficiencies of other nanoparticle chargers.

  11. Unipolar charging of nanoparticles by the Surface-discharge Microplasma Aerosol Charger (SMAC)

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Soon-Bark [Korea Railroad Research Institute, Environment and Fire Control Research Team (Korea, Republic of); Sakurai, Hiromu [National Institute of Advanced Industrial Science and Technology, National Metrology Institute of Japan (Japan); Seto, Takafumi [National Institute of Advanced Industrial Science and Technology, Advanced Manufacturing Research Institute (Japan)], E-mail: t.seto@aist.go.jp

    2007-08-15

    In this paper, we report the development of a novel unipolar charger for nanoparticles, a system that achieves low particle loss and high charging efficiency without the use of sheath air. The efficient unipolar charging of the system is realized mainly by the surface-discharge microplasma unit, a device previously applied with good success to the neutralization or charging of submicron particles [Kwon et al., 2005, Aerosol Sci. Technol., 39, 987-1001; 2006, J. Aerosol Sci., 37, 483-499]. The unipolar charger generates unipolar ions using the surface discharge of a single electrode with a DC pulse supply. This marks an advance from our previous method of generating bipolar ions with the use of dual electrodes in earlier studies. We evaluated the efficiency of the penetration (or loss) and charging of nanoparticles in the size range of 3-15 nm, then compared the charging efficiencies measured with those predicted by diffusion charging theory. More than 90% of inlet nanoparticles penetrated the charger (less than 10% of the particle were lost) without the use of sheath air. Other chargers have only realized this high penetration efficiency by relying on sheath air flow. Moreover, the measured charging efficiencies agreed well with those predicted by diffusion charging theory and were somewhat higher and more size-dependent than the charging efficiencies of other nanoparticle chargers.

  12. Unipolar charging of nanoparticles by the Surface-discharge Microplasma Aerosol Charger (SMAC)

    International Nuclear Information System (INIS)

    Kwon, Soon-Bark; Sakurai, Hiromu; Seto, Takafumi

    2007-01-01

    In this paper, we report the development of a novel unipolar charger for nanoparticles, a system that achieves low particle loss and high charging efficiency without the use of sheath air. The efficient unipolar charging of the system is realized mainly by the surface-discharge microplasma unit, a device previously applied with good success to the neutralization or charging of submicron particles [Kwon et al., 2005, Aerosol Sci. Technol., 39, 987-1001; 2006, J. Aerosol Sci., 37, 483-499]. The unipolar charger generates unipolar ions using the surface discharge of a single electrode with a DC pulse supply. This marks an advance from our previous method of generating bipolar ions with the use of dual electrodes in earlier studies. We evaluated the efficiency of the penetration (or loss) and charging of nanoparticles in the size range of 3-15 nm, then compared the charging efficiencies measured with those predicted by diffusion charging theory. More than 90% of inlet nanoparticles penetrated the charger (less than 10% of the particle were lost) without the use of sheath air. Other chargers have only realized this high penetration efficiency by relying on sheath air flow. Moreover, the measured charging efficiencies agreed well with those predicted by diffusion charging theory and were somewhat higher and more size-dependent than the charging efficiencies of other nanoparticle chargers

  13. The structure optimization of gas-phase surface discharge and its application for dye degradation

    Science.gov (United States)

    Ying, CAO; Jie, LI; Nan, JIANG; Yan, WU; Kefeng, SHANG; Na, LU

    2018-05-01

    A gas-phase surface discharge (GSD) was employed to optimize the discharge reactor structure and investigate the dye degradation. A dye mixture of methylene blue, acid orange and methyl orange was used as a model pollutant. The results indicated that the reactor structure of the GSD system with the ratio of tube inner surface area and volume of 2.48, screw pitch between a high-voltage electrode of 9.7 mm, high-voltage electrode wire diameter of 0.8 mm, dielectric tube thickness of 2.0 mm and tube inner diameter of 16.13 mm presented a better ozone (O3) generation efficiency. Furthermore, a larger screw pitch and smaller wire diameter enhanced the O3 generation. After the dye mixture degradation by the optimized GSD system, 73.21% and 50.74% of the chemical oxygen demand (COD) and total organic carbon removal rate were achieved within 20 min, respectively, and the biochemical oxygen demand (BOD) and biodegradability (BOD/COD) improved.

  14. Surface nitridation of silicon nano-particles using double multi-hollow discharge plasma CVD

    Energy Technology Data Exchange (ETDEWEB)

    Uchida, Giichiro; Yamamoto, Kosuke; Kawashima, Yuki; Sato, Muneharu; Nakahara, Kenta; Itagaki, Naho; Koga, Kazunori; Shiratani, Masaharu [Graduate School of Information Science and Electrical Engineering, Kyushu University, Fukuoka (Japan); Kamataki, Kunihiro [Center for Reserch and Advancement in Higher Education, Kyushu University, Fukuoka (Japan); Kondo, Michio [National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki (Japan)

    2011-10-15

    We present production of silicon nano-particles and their surface nitridation for efficient multiple-exciton generation. Nitridated silicon nano-particles were produced using double multi-hollow discharge plasma CVD, where generation of silicon particles and their nitridation were independently performed using SiH{sub 4}/H{sub 2} and N{sub 2} multi-hollow discharge plasmas. We succeeded in controlling nitrogen content in a silicon nano-particle by varying a number density of N radicals irradiated to the Si particle. We also observed strong photoluminescence (PL) emission around 300-500 nm from silicon nano-particles, where the PL peak energy is about 2.5 and 3.1 eV for pure Si nano-particles, and 2.5, 3.1, and 4.1 eV for nitridated Si nano-particles. The additional UV-peak of 4.1 eV from nitridated Si particles is closely related to the nitridation surface layer on Si nano-particles (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  15. Elimination of diazinon insecticide from cucumber surface by atmospheric pressure air-dielectric barrier discharge plasma.

    Science.gov (United States)

    Dorraki, Naghme; Mahdavi, Vahideh; Ghomi, Hamid; Ghasempour, Alireza

    2016-12-06

    The food industry is in a constant search for new technologies to improve the commercial sterilization process of agricultural commodities. Plasma treatment may offer a novel and efficient method for pesticide removal from agricultural product surfaces. To study the proposed technique of plasma food treatment, the degradation behavior of diazinon insecticide by air-dielectric barrier discharge (DBD) plasma was investigated. The authors studied the effect of different plasma powers and treatment times on pesticide concentration in liquid form and coated on the surface of cucumbers, where the diazinon residue was analyzed with mass spectroscopy gas chromatography. Our results suggest that atmospheric pressure air-DBD plasma is potentially effective for the degradation of diazinon insecticide, and mainly depends on related operating parameters, including plasma treatment time, discharge power, and pesticide concentrations. Based on the interaction between reactive oxygen species and electrons in the plasma with the diazinon molecule, two degradation pathway of diazinon during plasma treatment are proposed. It was also found that produced organophosphate pesticides are harmless and less hazardous compounds than diazinon.

  16. Determination of the cathode fall voltage in fluorescent lamps by measurement of the operating voltage

    International Nuclear Information System (INIS)

    Hilscher, A.

    2002-01-01

    A new method for the determination of the cathode fall voltage of fluorescent lamps is shown. The cathode fall voltage can be determined by measurement of the lamp operating voltage at constant lamp wall temperature, constant discharge current and variation of the electrode heating current. Commercial lamps, which do not need to be specially prepared, can be used for the measurement. The results show good correlation to other measurements of the cathode fall voltage at various discharge currents by means of capacitive coupling. The measured values of the cathode fall voltage are used for determining the minimum, target and maximum setting of the sum of the squares of the pin currents of one electrode (the so-called SOS value) as a function of the discharge current in fluorescent lamp dimming. (author)

  17. One piece microwave container screens for electrodeless lamps

    Science.gov (United States)

    Turner, Brian; Ury, Michael

    1998-01-01

    A microwave powered electrodeless lamp includes an improved screen unit having mesh and solid sections with an internal reflector to reflect light into a light-transmitting chamber defined in the lamp microwave cavity by the reflector and the mesh section. A discharge envelope of a bulb is disposed in the light-transmitting chamber. Light emitted from the envelope is prevented by the reflector from entering the cavity portion bounded by the solid section of the screen. Replacing mesh material by solid metal material as part of the screen unit significantly reduces leakage of microwave energy from the lamp. The solid section has multiple compliant fingers defined therein for engaging the periphery of a flange on the waveguide unit so that a hose clamp can easily secure the screen to the assembly. Screen units of this type having different mesh section configurations can be interchanged in the lamp assembly to produce different respective illumination patterns.

  18. Surface discharge of raw wastewater among unsewered homes in central Alabama

    Science.gov (United States)

    Elliott, M.; Das, P.; Blackwell, A.; Aytekin, E.; Hu, Y.; White, K.; Jones, R.; Lu, Y.

    2017-12-01

    Discussions of future water and wastewater challenges in the US typically focus on crumbling infrastructure. However, another major challenge has been almost entirely neglected. A growing body of evidence indicates that household discharge of untreated wastewater to the surface (through so-called "straight pipes") is widespread in poor rural communities of Appalachia and the southeastern US. The US Census included water and wastewater questions until 1990. However, the census questions do not appear to differentiate clearly between legal onsite treatment and discharge of raw wastewater to the ground (EPA, 1999; US Census, 2015). Although straight pipes are illegal, many reports from the southern US and Appalachia indicate that the practice is still common in poor rural areas (e.g., EPA Region 4, 2002; du Albuquerque, 2011). A representative, county-scale report on straight pipes in Madison County, NC (Baldwin, 2000) found that 5.6% of unsewered rural households directly discharged raw wastewater and a 2005 study of Bibb County, AL, reported 15% straight pipe among households not connected to sewer (White and Jones, 2006). We focused on two Alabama counties (Hale and Wilcox) with high rates of rural poverty (26.6% and 39.2% of households in poverty, respectively) and soils unsuited for conventional septic systems. We used two main methods (1) site-by-site inspections of a random sample of unsewered rural homes and (2) water sample collection and analysis from impacted streams. We found high rates of straight pipe use and substantial impacts on water quality in local streams. For example, in Wilcox Co., 60% of unsewered households had a visible straight pipe; conservatively, these homes discharge 500,000 gallons of raw sewage to the ground in Wilcox Co. each day. Water sampling upstream and downstream of an unsewered town with many straight pipes indicated major impacts on surface water quality. Additionally, the literature reveals possible health impacts from onsite

  19. Recharge and discharge of near-surface groundwater in Forsmark. Comparison of classification methods

    International Nuclear Information System (INIS)

    Werner, Kent; Johansson, Per-Olof; Brydsten, Lars; Bosson, Emma; Berglund, Sten

    2007-03-01

    This report presents and compares data and models for identification of near-surface groundwater recharge and discharge (RD) areas in Forsmark. The general principles of groundwater recharge and discharge are demonstrated and applied to interpret hydrological and hydrogeological observations made in the Forsmark area. 'Continuous' RD classification methods considered in the study include topographical modelling, map overlays, and hydrological-hydrogeological flow modelling. 'Discrete' (point) methods include field-based and hydrochemistry-based RD classifications of groundwater monitoring well locations. The topographical RD modelling uses the digital elevation model as the only input. The map overlays use background maps of Quaternary deposits, soils, and ground- and field layers of the vegetation/land use map. Further, the hydrological-hydrogeological modelling is performed using the MIKE SHE-MIKE 11 software packages, taking into account e.g. topography, meteorology, hydrogeology, and geometry of watercourses and lakes. The best between-model agreement is found for the topography-based model and the MIKE SHE-MIKE 11 model. The agreement between the topographical model and the map overlays is less good. The agreement between the map overlays on the one hand, and the MIKE SHE and field-based RD classifications on the other, is thought to be less good, as inferred from the comparison made with the topography-based model. However, much improvement of the map overlays can likely be obtained, e.g. by using 'weights' and calibration (such exercises were outside the scope of the present study). For field-classified 'recharge wells', there is a good agreement to the hydrochemistry-based (Piper plot) well classification, but less good for the field-classified 'discharge wells'. In addition, the concentration of the age-dating parameter tritium shows low variability among recharge wells, but a large spread among discharge wells. The usefulness of hydrochemistry-based RD

  20. Recharge and discharge of near-surface groundwater in Forsmark. Comparison of classification methods

    Energy Technology Data Exchange (ETDEWEB)

    Werner, Kent [Golder Associates AB, Uppsala (Sweden); Johansson, Per-Olof [Artesia Grundvattenkonsult AB, Taeby (Sweden); Brydsten, Lars [Umeaa University, Dept. of Ecology and Environmental Science (Sweden); Bosson, Emma; Berglund, Sten [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden)

    2007-03-15

    This report presents and compares data and models for identification of near-surface groundwater recharge and discharge (RD) areas in Forsmark. The general principles of groundwater recharge and discharge are demonstrated and applied to interpret hydrological and hydrogeological observations made in the Forsmark area. 'Continuous' RD classification methods considered in the study include topographical modelling, map overlays, and hydrological-hydrogeological flow modelling. 'Discrete' (point) methods include field-based and hydrochemistry-based RD classifications of groundwater monitoring well locations. The topographical RD modelling uses the digital elevation model as the only input. The map overlays use background maps of Quaternary deposits, soils, and ground- and field layers of the vegetation/land use map. Further, the hydrological-hydrogeological modelling is performed using the MIKE SHE-MIKE 11 software packages, taking into account e.g. topography, meteorology, hydrogeology, and geometry of watercourses and lakes. The best between-model agreement is found for the topography-based model and the MIKE SHE-MIKE 11 model. The agreement between the topographical model and the map overlays is less good. The agreement between the map overlays on the one hand, and the MIKE SHE and field-based RD classifications on the other, is thought to be less good, as inferred from the comparison made with the topography-based model. However, much improvement of the map overlays can likely be obtained, e.g. by using 'weights' and calibration (such exercises were outside the scope of the present study). For field-classified 'recharge wells', there is a good agreement to the hydrochemistry-based (Piper plot) well classification, but less good for the field-classified 'discharge wells'. In addition, the concentration of the age-dating parameter tritium shows low variability among recharge wells, but a large spread among discharge

  1. Application of Glow Discharge Plasma to Alter Surface Properties of Materials

    Science.gov (United States)

    Trigwell, Steve; Buhler, Charles R.; Calle, Carlos I.

    2005-01-01

    Some polymer materials that are considered important for spaceport operations are rendered noncompliant when subjected to the Kennedy Space Center (KSC) Standard electrostatic testing. These materials operate in stringent environmental conditions, such as high humidity. Treating materials that fail electrostatic testing and altering their surface properties so that they become compliant would result in considerable cost savings. Significant improvement in electrostatic dissipation of Saf-T-Vu PVC after treatment with air Atmospheric Plasma Glow Discharge (APGD) was observed and the material now passed the KSC electrostatic test. The O:C ratio on the surface, as monitored by X-ray Photoelectron Spectroscopy, increased from 0.165 tO 0.275 indicating enhanced oxidation, and surface contact angle measurements decreased from 107.5 to 72.6 showing increased hydrophilicity that accounted for the increased conductivity. Monitoring of the aging showed that the materials hydrophobic recovery resulted in it failing the electrostatic test 30 hours after treatment. This was probably due to the out-diffusion of the added Zn, Ba, and Cd salt stabilizers detected on the surface and/or diffusion of low molecular weight oligomers. On going work includes improving the long term hydrophilicity by optimizing the APGD process with different gas mixtures. Treatment of other spaceport materials is also presented.

  2. Comparative study of NO removal in surface-plasma and volume-plasma reactors based on pulsed corona discharges.

    Science.gov (United States)

    Malik, Muhammad Arif; Kolb, Juergen F; Sun, Yaohong; Schoenbach, Karl H

    2011-12-15

    Nitric oxide (NO) conversion has been studied for two different types of atmospheric-pressure pulsed-corona discharges, one generates a surface-plasma and the other provides a volume-plasma. For both types of discharges the energy cost for NO removal increases with decreasing oxygen concentration and initial concentration of NO. However, the energy cost for volume plasmas for 50% NO removal, EC(50), from air was found to be 120 eV/molecule, whereas for the surface plasma, it was only 70 eV/molecule. A smaller difference in energy cost, but a higher efficiency for removal of NO was obtained in a pure nitrogen atmosphere, where NO formation is restricted due to the lack of oxygen. For the volume plasma, EC(50) in this case was measured at 50 eV/molecule, and for the surface plasma it was 40 eV/molecule. Besides the higher NO removal efficiency of surface plasmas compared to volume plasmas, the energy efficiency of surface-plasmas was found to be almost independent of the amount of electrical energy deposited in the discharge, whereas the efficiency for volume plasmas decreases considerably with increasing energy. This indicates the possibility of operating surface plasma discharges at high energy densities and in more compact reactors than conventional volume discharges. Published by Elsevier B.V.

  3. Effects of rf power on chemical composition and surface roughness of glow discharge polymer films

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Ling; He, Xiaoshan; Chen, Guo; Wang, Tao; Tang, Yongjian; He, Zhibing, E-mail: hezhibing802@163.com

    2016-03-15

    Graphical abstract: - Highlights: • The growth mechanism of defects in GDP films was studied upon plasma diagnosis. • Increasing rf power enhanced the etching effects of smaller-mass species. • The “void” defect was caused by high energy hydrocarbons bombardment on the surface. • The surface roughness was only 12.76 nm, and no “void” defect was observed at 30 W. - Abstract: The glow discharge polymer (GDP) films for laser fusion targets were successfully fabricated by plasma enhanced chemical vapor deposition (PECVD) at different radio frequency (rf) powers. The films were deposited using trans-2-butene (T{sub 2}B) mixed with hydrogen as gas sources. The composition and state of plasma were diagnosed by quadrupole mass spectrometer (QMS) and Langmuir probe during the deposition process. The composition, surface morphology and roughness were investigated by Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM) and white-light interferometer (WLI), respectively. Based on these observation and analyses, the growth mechanism of defects in GDP films were studied. The results show that, at low rf power, there is a larger probability for secondary polymerization and formation of multi-carbon C-H species in the plasma. In this case, the surface of GDP film turns to be cauliflower-like. With the increase of rf power, the degree of ionization is high, the relative concentration of smaller-mass hydrocarbon species increases, while the relative concentration of larger-mass hydrocarbon species decreases. At higher rf power, the energy of smaller-mass species are high and the etching effects are strong correspondingly. The GDP film's surface roughness shows a trend of decrease firstly and then increase with the increasing rf power. At rf power of 30 W, the surface root-mean-square roughness (Rq) drops to the lowest value of 12.8 nm, and no “void” defect was observed.

  4. Effect of corona discharge plasma jet on surface-borne microorganisms and sprouting of broccoli seeds.

    Science.gov (United States)

    Kim, Je-Wook; Puligundla, Pradeep; Mok, Chulkyoon

    2017-01-01

    Different pathogenic microorganisms have been reported to cause sprouts-associated outbreaks. In order to sterilise and enhance the germination of seeds, non-thermal plasma has been increasingly investigated in the field of agricultural science as an alternative to the traditional pre-sowing seed treatments. This work aimed to evaluate the effect of corona discharge plasma jet (CDPJ) on disinfection of the natural bio-contaminants of broccoli seed and also studied the plasma effect on sprout seed germination rate and physico-chemical properties of sprouts. Aerobic bacteria, moulds and yeasts, B. cereus, E. coli, Salmonella spp. were detected on the broccoli seed surface. After 0-3 min treatment using CDPJ, the detected microorganisms were reduced in the range of 1.2-2.3 log units. Inactivation patterns were better explained using pseudo-first-order kinetics. The plasma treatment of seeds up to 2 min exhibited a positive effect on germination rate, seedling growth. The physico-chemical and sensory characteristics of sprouts were unaffected due to the CDPJ treatment of their respective seeds. Corona discharge plasma jet can potentially be used for microbial decontamination of broccoli seeds. In addition, the plasma treatment of broccoli sprout seeds has enabled a significant enhancement in their germination rate and seedling growth without compromising physico-chemical and sensory characteristics of their corresponding sprouts. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  5. [Study on plasma temperature of a large area surface discharge by optical emission spectrum].

    Science.gov (United States)

    Dong, Li-Fang; Tong, Guo-Liang; Zhang, Yu; Zhou, Bin

    2014-04-01

    A large area surface discharge was realized in air/argon gas mixture by designing a discharge device with water electrodes. By using optical emission spectrum, the variations of the molecular vibrational temperature, the mean energy of electron, and the electronic excitation temperature as a function of the gas pressure were studied. The nitrogen molecular vibrational temperature was calculated according to the emission line of the second positive band system of the nitrogen molecule (C3 pi(u) --> B 3 pi(g)). The electronic excitation temperature was obtained by using the intensity ratio of Ar I 763.51 nm (2P(6) --> 1S(5)) to Ar I 772.42 nm (2P(2) --> 1S(3)). The changes in the mean energy of electron were studied by the relative intensity ratio of the nitrogen molecular ion 391.4 nm to nitrogen 337.1 nm. It was found that the intensity of emission spectral line increases with the increase in the gas pressure, meanwhile, the outline and the ratios of different spectral lines intensity also change. The molecular vibrational temperature, the mean energy of electron, and the electronic excitation temperature decrease as the gas pressure increases from 0.75 x 10(5) Pa to 1 x 10(5) Pa.

  6. A mathematical model for surface roughness of fluidic channels produced by grinding aided electrochemical discharge machining (G-ECDM

    Directory of Open Access Journals (Sweden)

    Ladeesh V. G.

    2017-01-01

    Full Text Available Grinding aided electrochemical discharge machining is a hybrid technique, which combines the grinding action of an abrasive tool and thermal effects of electrochemical discharges to remove material from the workpiece for producing complex contours. The present study focuses on developing fluidic channels on borosilicate glass using G-ECDM and attempts to develop a mathematical model for surface roughness of the machined channel. Preliminary experiments are conducted to study the effect of machining parameters on surface roughness. Voltage, duty factor, frequency and tool feed rate are identified as the significant factors for controlling surface roughness of the channels produced by G-ECDM. A mathematical model was developed for surface roughness by considering the grinding action and thermal effects of electrochemical discharges in material removal. Experiments are conducted to validate the model and the results obtained are in good agreement with that predicted by the model.

  7. Prediction of material removal rate and surface roughness for wire electrical discharge machining of nickel using response surface methodology

    Directory of Open Access Journals (Sweden)

    Thangam Chinnadurai

    2016-12-01

    Full Text Available This study focuses on investigating the effects of process parameters, namely, Peak current (Ip, Pulse on time (Ton, Pulse off time (Toff, Water pressure (Wp, Wire feed rate (Wf, Wire tension (Wt, Servo voltage (Sv and Servo feed setting (Sfs, on the Material Removal Rate (MRR and Surface Roughness (SR for Wire electrical discharge machining (Wire-EDM of nickel using Taguchi method. Response Surface Methodology (RSM is adopted to evolve mathematical relationships between the wire cutting process parameters and the output variables of the weld joint to determine the welding input parameters that lead to the desired optimal wire cutting quality. Besides, using response surface plots, the interaction effects of process parameters on the responses are analyzed and discussed. The statistical software Mini-tab is used to establish the design and to obtain the regression equations. The developed mathematical models are tested by analysis-of-variance (ANOVA method to check their appropriateness and suitability. Finally, a comparison is made between measured and calculated results, which are in good agreement. This indicates that the developed models can predict the responses accurately and precisely within the limits of cutting parameter being used.

  8. Prediction of material removal rate and surface roughness for wire electrical discharge machining of nickel using response surface methodology

    Energy Technology Data Exchange (ETDEWEB)

    Chinnadurai, T.; Vendan, S.A.

    2016-07-01

    This study focuses on investigating the effects of process parameters, namely, Peak current (Ip), Pulse on time (Ton), Pulse off time (Toff), Water pressure (Wp), Wire feed rate (Wf), Wire tension (Wt), Servo voltage (Sv) and Servo feed setting (Sfs), on the Material Removal Rate (MRR) and Surface Roughness (SR) for Wire electrical discharge machining (Wire-EDM) of nickel using Taguchi method. Response Surface Methodology (RSM) is adopted to evolve mathematical relationships between the wire cutting process parameters and the output variables of the weld joint to determine the welding input parameters that lead to the desired optimal wire cutting quality. Besides, using response surface plots, the interaction effects of process parameters on the responses are analyzed and discussed. The statistical software Mini-tab is used to establish the design and to obtain the regression equations. The developed mathematical models are tested by analysis-of-variance (ANOVA) method to check their appropriateness and suitability. Finally, a comparison is made between measured and calculated results, which are in good agreement. This indicates that the developed models can predict the responses accurately and precisely within the limits of cutting parameter being used. (Author)

  9. Emission spectra from direct current and microwave powered Hg lamps at very high pressure

    International Nuclear Information System (INIS)

    Hamady, M; Stafford, L; Lister, G G

    2013-01-01

    Discharge lamps containing mercury at pressures above 100 bar are commercially used in data projectors and television projector systems. Due to their small size, these lamps are difficult to investigate experimentally, but spectral measurements, combined with radiation transport calculations, have provided useful information on the visible spectrum. However, classical spectral line broadening theory is inadequate to describe the UV portion of the spectrum, so self-consistent modelling of these discharges is not possible at present. This paper discusses the differences between discharges containing electrodes and discharges sustained by a microwave (mw) electromagnetic field, on the basis of the experimentally measured temperature profile in an electroded discharge, and a temperature profile computed from a 1D power balance model for a microwave discharge. A model based on the ray-tracing method is employed to simulate the radiation transport in these lamps. The model has been validated by comparing the emission spectrum from dc discharge lamps with those obtained experimentally. The output flux, luminous flux, luminous efficacy, the correlated colour temperature, the chromaticity coordinates and photometric curves of the lamp were then obtained. These results were also compared with those of a theoretically calculated temperature profile for the same lamp, excited by microwave power in the TM 010 mode. (paper)

  10. Waste Field Characteristics, Ultimate Mixing and Dilution in Surface Discharge of Dense Jets into Stagnant Water Bodies

    Directory of Open Access Journals (Sweden)

    2012-04-01

    Full Text Available Direct discharges of municipal and industrial waste waters into water bodies through marine outfalls are considered as a common way to dispose the generated waste in coastal zones. Marine discharge, intensifying flow mixing and entrainment, decrease the concentration of polutant up to accepted concentration and meet the guideline values and to make possible continues discharge of flow into matine environment. During last years due to quick development of coastal desalination plants, surface discharge of preduced salty water into seas and oceans has increased significantly. In this study, releases of dense jets from surface rectangular channel into stagnant bodies are experimentally studied. The location of flow plunge point, impact point and discharge ultimate dilution were drown out by a digital video technology. In addition, using some conductivity probes located in ambient floor, waste filed dilution in flow impact point and discharge ultimate dilution were identified. Finally the obtained results were plotted and explained along with some diagrams to show flow non-dimensional behavior. The results showed that the properties of flow are changing directly with ambient water depth and discharge initial fluxes.

  11. Investigation of Atmospheric Pressure Plasma Discharge and Its Application to Surface Modification of Blood-Filtering Material

    Science.gov (United States)

    Tang, Xiaoliang; Feng, Xianping; Qiu, Gao; Yan, Yonghui; Shi, Yuncheng

    2004-10-01

    Melt-blown polybutylene terephthalate (PBT) nonwoven materials treated by using plasma is regarded as one of the excellent materials to filter white blood cells (WBC) from blood. In this paper, dielectric barrier discharge (DBD) plasma source at an improved quasi-stable atmospheric pressure is achieved when discharge voltage, discharge current, and gap between the electrodes are carefully controlled. This plasma source has been used to modify the surface of PBT melt-blown nonwoven materials. Experimental results indicate that both the wettability and permeation of treated PBT melt-blown nonwoven materials are greatly improved.

  12. Investigation of atmospheric pressure plasma discharge and its application to surface modification of blood-filtering material

    International Nuclear Information System (INIS)

    Tang Xiaoliang; Qiu Gao; Yan Yonghui; Shi Yuncheng

    2004-01-01

    Melt-blown polybutylene terephthalate (PBT) nonwoven materials treated by using plasma is regarded as one of the excellent materials to filter white blood cells (WBC) from blood. In this paper, dielectric barrier discharge (DBD) plasma source at an improved quasi-stable atmospheric pressure is achieved when discharge voltage, discharge current, and gap between the electrodes are carefully controlled. This plasma source has been used to modify the surface of PBT melt-blown nonwoven materials. Experimental results indicate that both the wettability and permeation of treated PBT melt-blown nonwoven materials are greatly improved. (authors)

  13. Electrical discharge light sources: a challenge for the future

    International Nuclear Information System (INIS)

    Zissis, G.

    2001-01-01

    The first electric powder lamp operated that 150 years ago, since then the evolution of light sources is astonishing. Today, more than 10 % of the global electric power produced worldwide serve fore light production from several billions lamps. Since last three decades incandescent lamps are gradually replaced by more energy efficient discharge lamps. In parallel, new generation of light emitting diodes, producing bright colours (including white) with luminous efficacy challenging even discharge lamps, appeared in past years. The objective of this paper is to focus on the state of art in the domain of light sources and discuss the challenges for the near future. (author)

  14. Surface Coating Constraint Induced Self-Discharging of Silicon Nanoparticles as Anodes for Lithium Ion Batteries

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Langli; Zhao, Peng; Yang, Hui; Liu, Borui; Zhang, Jiguang; Cui, Yi; Yu, Guihua; Zhang, Sulin; Wang, Chong M.

    2015-10-01

    One of the key challenges of Si-based anodes for lithium ion batteries is the large volume change upon lithiation and delithiation, which commonly leads to electrochemo-mechanical degradation and subsequent fast capacity fading. Recent studies have shown that applying nanometer-thick coating layers on Si nanoparticle (SiNPs) enhances cyclability and capacity retention. However, it is far from clear how the coating layer function from the point of view of both surface chemistry and electrochemo-mechanical effect. Herein, we use in situ transmission electron microscopy to investigate the lithiation/delithiation kinetics of SiNPs coated with a conductive polymer, polypyrrole (PPy). We discovered that this coating layer can lead to “self-delithiation” or “self-discharging” at different stages of lithiation. We rationalized that the self-discharging is driven by the internal compressive stress generated inside the lithiated SiNPs due to the constraint effect of the coating layer. We also noticed that the critical size of lithiation-induced fracture of SiNPs is increased from ~ 150 nm for bare SiNPs to ~ 380 nm for the PPy-coated SiNPs, showing a mechanically protective role of the coating layer. These observations demonstrate both beneficial and detrimental roles of the surface coatings, shedding light on rational design of surface coatings for silicon to retain high-power and high capacity as anode for lithium ion batteries.

  15. Field-emitting Townsend regime of surface dielectric barrier discharges generated in CO2 emerging at high pressure

    Science.gov (United States)

    Pai, David; Stauss, Sven; Terashima, Kazuo

    2015-09-01

    Surface dielectric barrier discharges (DBDs) in CO2 from atmospheric pressure up to supercritical conditions (Tc = 304.13 K, pc = 7.4 MPa) generated using 10-kHz ac excitation are studied experimentally. Two discharge regimes are obtained: the standard and field-emitting Townsend regimes. The former resembles typical surface DBDs that have streamer-like characteristics, but the latter has not been reported previously. Here we present an analysis of the electrical and optical diagnostics of the field-emitting Townsend discharge regime using current-voltage and charge-voltage measurements, imaging, optical emission spectroscopy, and spontaneous Raman spectroscopy. Using an electrical model, it is possible to calculate the discharge-induced capacitances of the plasma and the dielectric, as well as the space-averaged values of the surface potential and the potential drop across the discharge. The model also accounts for the space-averaged Laplacian field by including the capacitance due to the fringe electric field from the electrode edge. The electrical characteristics are similar to those of atmospheric-pressure Townsend DBDs, i.e. self-sustained DBDs with minimal space-charge effects. The purely continuum emission spectrum is due to electron-neutral bremsstrahlung, with a corresponding average electron temperature of 2600 K. Raman spectra of CO2 near the critical point demonstrate that the discharge increases the average gas temperature by less than 1 K. This work was supported financially in part by MEXT and JSPS.

  16. Surface modification of chitosan/PEO nanofibers by air dielectric barrier discharge plasma for acetylcholinesterase immobilization

    Energy Technology Data Exchange (ETDEWEB)

    Dorraki, Naghme, E-mail: n.dorraki@web.sbu.ac.ir [Laser and Plasma Research Institute, Shahid Beheshti University, Evin 1983963113, Tehran (Iran, Islamic Republic of); Safa, Nasrin Navab [Laser and Plasma Research Institute, Shahid Beheshti University, Evin 1983963113, Tehran (Iran, Islamic Republic of); Jahanfar, Mehdi [Protein Research Center, Shahid Beheshti University, Evin 1983963113, Tehran (Iran, Islamic Republic of); Ghomi, Hamid [Laser and Plasma Research Institute, Shahid Beheshti University, Evin 1983963113, Tehran (Iran, Islamic Republic of); Ranaei-Siadat, Seyed-Omid [Protein Research Center, Shahid Beheshti University, Evin 1983963113, Tehran (Iran, Islamic Republic of)

    2015-09-15

    Highlights: • We used an economical and effective method for surface modification. • Chitosan/PEO nanofibrous membranes were modified by air-DBD plasma. • The most NH{sub 3}{sup +} group was generated on the 6 min plasma modified membrane. • We immobilized acetylcholinesterase on the plasma modified and unmodified membranes. • More enzyme activity was detected on the modified membrane by plasma. - Abstract: There are different methods to modify polymer surfaces for biological applications. In this work we have introduced air-dielectric barrier discharge (DBD) plasma at atmospheric pressure as an economical and safe method for modifying the surface of electrospun chitosan/PEO (90/10) nanofibers for acetylcholinesterase (AChE) immobilization. According to the contact angle measurement results, the nanofibers become highly hydrophilic when they are exposed to the DBD plasma for 6 min in compared to unmodified membrane. Attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) results reveal hydroxyl, C=O and NH{sub 3}{sup +} polar groups increment after 6 min plasma treatment. Contact angle measurements and ATR-FTIR results are confirmed by X-ray photoelectron spectroscopy (XPS). AChE at pH 7.4 carries a negative charge and after immobilization on the surface of plasma-treated nanofibrous membrane attracts the NH{sub 3}{sup +} group and more enzyme activity is detected on the plasma-modified nanofibers for 6 min in compared to unmodified nanofibers. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) are used for the surface topography and morphology characterization. The results have proved that air-DBD plasma is a suitable method for chitosan/PEO nanofibrous membrane modification as a biodegradable and functionalized substrate for enzyme immobilization.

  17. Use of glow discharge in measurement of diffusion profile

    International Nuclear Information System (INIS)

    Baudin, Guy

    1976-05-01

    The composition of a glow discharge plasma is a good image of the composition of the surface being erroded without fusion. The depth of metal eated away is a linear function of time in 10 to 60μ range, that is too say between 2 and 20 minutes after lightning of the lamp. So measuring the emission of the discharge is function of time gives the diffusion profile of elements either by measuring instantaneous signal or by integrating during short periods of time for weak concentration. Examples of application for diffusion of N 2 and C in steel will be given [fr

  18. Screening for Ocular Surface Squamous Neoplasia (OSSN by Slit-lamp Assisted Visual Inspection (SAVI following a short course of mild topical steroid-test qualities

    Directory of Open Access Journals (Sweden)

    E. Katsekera

    2014-08-01

    Results: Total number of patients with conjunctival growths screened by visual inspection was 119, with median age of 42 years and a range of 18 to 90 years and gender ratio of 1:1.9 in favour of females. There was no significant age difference between confirmed OSSN patients and non-OSSN (pterygia and the p-value was 0.617. Sensitivity and specificity of visual inspection in diagnosing OSSN when compared to histology were 94.3% and 74.2% respectively, with a positive predictive value of 74.6%. Histology reports indicated that 24.5% of OSSN specimens seen actually arose from pterygia. Conclusions: Slit lamp assisted visual inspection (SAVI is an accurate method of clinically diagnosing OSSN and can be recommended for use in resource limited settings with hard to access histopathological services.

  19. Numerical Investigation of Scattering from a Surface Dielectric Barrier Discharge Actuator under Atmospheric Pressure

    Directory of Open Access Journals (Sweden)

    Yuna Kim

    2018-01-01

    Full Text Available Surface dielectric barrier discharge (SDBD, which is widely used to control turbulence in aerodynamics, has a significant effect on the radar cross-section (RCS. A four-way linearly synthesized SDBD air plasma actuator is designed to bolster the plasma effects on electromagnetic waves. The diffraction angle is calculated to predict the RCS because of the periodic structure of staggered electrodes. The simplified plasma modeling is utilized to calculate the inhomogeneous surface plasma distribution. Monostatic RCS shows the diffraction in the plane perpendicular to the electrode array and the notable distortion by plasma. In comparison, the overall pattern is maintained in the parallel plane with minor plasma effects. The trends also appear in the bistatic RCS, which has a significant difference in the observation plane perpendicular to the electrodes. The peaks by Bragg’s diffraction are shown, and the RCS is reduced by 10 dB in a certain range by the plasma effect. The diffraction caused by the actuator and the inhomogeneous air plasma should be considered in designing an SDBD actuator for a wide range of application.

  20. Cell treatment and surface functionalization using a miniature atmospheric pressure glow discharge plasma torch

    International Nuclear Information System (INIS)

    Yonson, S; Coulombe, S; Leveille, V; Leask, R L

    2006-01-01

    A miniature atmospheric pressure glow discharge plasma torch was used to detach cells from a polystyrene Petri dish. The detached cells were successfully transplanted to a second dish and a proliferation assay showed the transplanted cells continued to grow. Propidium iodide diffused into the cells, suggesting that the cell membrane had been permeabilized, yet the cells remained viable 24 h after treatment. In separate experiments, hydrophobic, bacteriological grade polystyrene Petri dishes were functionalized. The plasma treatment reduced the contact angle from 93 0 to 35 0 , and promoted cell adhesion. Two different torch nozzles, 500 μm and 150 μm in internal diameter, were used in the surface functionalization experiments. The width of the tracks functionalized by the torch, as visualized by cell adhesion, was approximately twice the inside diameter of the nozzle. These results indicate that the miniature plasma torch could be used in biological micropatterning, as it does not use chemicals like the present photolithographic techniques. Due to its small size and manouvrability, the torch also has the ability to pattern complex 3D surfaces

  1. Active species delivered by dielectric barrier discharge filaments to bacteria biofilms on the surface of apple

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, He; Liu, Xin; Lu, Xinpei [State Key Lab of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, WuHan, HuBei (China); IFSA Collaborative Innovation Center, Shanghai Jiao Tong University, Shanghai 200240 (China); Liu, Dawei, E-mail: ldw636@msn.com [State Key Lab of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, WuHan, HuBei (China); IFSA Collaborative Innovation Center, Shanghai Jiao Tong University, Shanghai 200240 (China); State Key Laboratory of Electrical Insulation and Power Equipment, Xi' an Jiaotong University, Xi' an (China)

    2016-07-15

    The atmospheric pressure non-equilibrium plasma has shown a significant potential as a novel food decontamination technology. In this paper, we report a computational study of the intersection of negative streamer produced by air dielectric barrier discharge with bacteria biofilm on an apple surface. The structure, conductivities, and permittivities of bacteria biofilm have been considered in the Poisson's equations and transportation equations of charge and neutral species to realize self-consistent transportation of plasma between electrode and charging surfaces of apple. We find that the ionization near the biofilm facilitates the propagation of negative streamer when the streamer head is 1 mm from the biofilm. The structure of the biofilm results in the non-uniform distribution of ROS and RNS captured by flux and time fluence of these reactive species. The mean free path of charged species in μm scale permitted the plasma penetrate into the cavity of the biofilm, therefore, although the density of ROS and RNS decrease by 6–7 order of magnitude, the diffusion results in the uniform distribution of ROS and RNS inside the cavity during the pulse off period.

  2. Experimental study of surface roughness in Electric Discharge Machining (EDM based on Grey Relational Analysis

    Directory of Open Access Journals (Sweden)

    Mat Deris Ashanira

    2016-01-01

    Full Text Available Electric Discharge Machining (EDM is one of the modern machining which is capable in handling hard and difficult-to-machine material. The successful of EDM basically depends on its performances such as surface roughness (Ra, material removal rate (MRR, electrode wear rate (EWR and dimensional accuracy (DA. Ra is considered as the most important performance due to it role as a technological quality measurement for a product and also a factor that significantly affects the manufacturing process. This paper presents the experimental study of surface roughness in die sinking EDM using stainless steel SS316L with copper impregnated graphite electrode. The machining experimental is conducted based on the two levels full factorial design of design of experiment (DOE with five machining parameters which are peak current, servo voltage, servo speed, pulse on time and pulse off time. The results were analyzed using grey relational analysis (GRA and it was found that pulse on time and servo voltage give the most influence to the Ra value.

  3. Thin surface layers of SiO2 obtained from tetraethoxysilane (TEOS) in electric discharges stabilized by a dielectric barrier

    International Nuclear Information System (INIS)

    Schmidt-Szalowski, K.; Fabianowski, W.; Rzanek-Boroch, Z.; Gutkowski, R.

    1998-01-01

    The reported research was devoted to the process of thin layer deposition in a discharge at atmospheric pressure stabilized by a dielectric barrier. Thin surface layers composed mainly of silicon dioxide were produced by polycondensation of tetraethoxysilane vapor in mixtures with helium gas with a small amount of oxygen. The influence was studied of the voltage applied and of the time elapsed in the deposition process, on the thickness of the layer, as were the changes of composition of the deposited layers during and after storage. It is shown that good passivating pinhole-free silicon oxide layers can be produced in surface barrier discharges. (J.U.)

  4. Reduction of microbial contamination and improvement of germination of sweet basil (Ocimum basilicum L.) seeds via surface dielectric barrier discharge

    Czech Academy of Sciences Publication Activity Database

    Ambrico, P. F.; Šimek, Milan; Morano, M.; De Miccolis Angelini, R.M.; Minafra, A.; Trotti, P.; Ambrico, M.; Prukner, Václav; Faretra, F.

    2017-01-01

    Roč. 50, č. 30 (2017), č. článku 305401. ISSN 0022-3727 R&D Projects: GA ČR(CZ) GA15-04023S Institutional support: RVO:61389021 Keywords : dielectric barrier discharges (DBD) * bio-decontamination * etching * polymers * biomolecules * spores * surface treatment Subject RIV: BL - Plasma and Gas Discharge Physics OBOR OECD: Fluids and plasma physics (including surface physics) Impact factor: 2.588, year: 2016 https://doi.org/10.1088/1361-6463/aa77c8

  5. Influence of surface emission processes on a fast-pulsed dielectric barrier discharge in air at atmospheric pressure

    Science.gov (United States)

    Pechereau, François; Bonaventura, Zdeněk; Bourdon, Anne

    2016-08-01

    This paper presents simulations of an atmospheric pressure air discharge in a point-to-plane geometry with a dielectric layer parallel to the cathode plane. Experimentally, a discharge reignition in the air gap below the dielectrics has been observed. With a 2D fluid model, it is shown that due to the fast rise of the high voltage applied and the sharp point used, a first positive spherical discharge forms around the point. Then this discharge propagates axially and impacts the dielectrics. As the first discharge starts spreading on the upper dielectric surface, in the second air gap with a low preionization density of {{10}4}~\\text{c}{{\\text{m}}-3} , the 2D fluid model predicts a rapid reignition of a positive discharge. As in experiments, the discharge reignition is much slower, a discussion on physical processes to be considered in the model to increase the reignition delay is presented. The limit case with no initial seed charges in the second air gap has been studied. First, we have calculated the time to release an electron from the cathode surface by thermionic and field emission processes for a work function φ \\in ≤ft[3,4\\right] eV and an amplification factor β \\in ≤ft[100,220\\right] . Then a 3D Monte Carlo model has been used to follow the dynamics of formation of an avalanche starting from a single electron emitted at the cathode. Due to the high electric field in the second air gap, we have shown that in a few nanoseconds, a Gaussian cloud of seed charges is formed at a small distance from the cathode plane. This Gaussian cloud has been used as the initial condition of the 2D fluid model in the second air gap. In this case, the propagation of a double headed discharge in the second air gap has been observed and the reignition delay is in rather good agreement with experiments.

  6. Surface quality analysis of die steels in powder-mixed electrical discharge machining using titan powder in fine machining

    Directory of Open Access Journals (Sweden)

    Banh Tien Long

    2016-06-01

    Full Text Available Improving the quality of surface molds after electrical discharge machining is still being considered by many researchers. Powder-mixed dielectric in electrical discharge machining showed that it is one of the processing methods with high efficiency. This article reports on the results of surface quality of mold steels after powder-mixed electrical discharge machining using titanium powder in fine machining. The process parameters such as electrode material, workpiece material, electrode polarity, pulse on-time, pulse off-time, current, and titanium powder concentration were considered in the research. These materials are most commonly used with die-sinking electrical discharge machining in the manufacture of molds and has been selected as the subject of research: workpiece materials were SKD61, SKT4, and SKD11 mold steels, and electrode materials were copper and graphite. Taguchi’s method is used to design experiments. The influence of the parameters on surface roughness was evaluated through the average value and ratio (S/N. Results showed that the parameters such as electrical current, electrode material, pulse on-time, electrode polarity, and interaction between the electrode materials with concentration powder mostly influence surface roughness and surface roughness at optimal parameters SRopt = 1.73 ± 0.39 µm. Analysis of the surface layer after powder-mixed electrical discharge machining using titanium powder in optimal conditions has shown that the white layer with more uniform thickness and increased hardness (≈861.0 HV, and amount and size of microscopic cracks, is reduced. This significantly leads to the increase in the quality of the surface layer.

  7. Transport phenomena of aluminium oxide in metal halide lamps

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, S; Markus, T [Institute for Energy Research, Forschungszentrum Juelich GmbH, D-52425 Juelich (Germany); Niemann, U [Philips GmbH, Research Laboratories, PO Box 500145, Aachen, D-52085 (Germany)], E-mail: s.fischer@fz-juelich.de

    2008-07-21

    A better understanding of the transport phenomena observed in metal halide lamps can be achieved using computer-based model calculations. The chemical transport of aluminium oxide in advanced high-pressure discharge vessels was calculated as a function of temperature and composition of the salt mixture relevant to the lamp. Below 1773 K chemical transport is the prevailing process; above this temperature the vaporization and condensation of the envelope material-aluminium oxide-become more important. The results of the calculations show that the amount of transported alumina increases linearly with the number of iteration cycles and exponentially with the temperature gradient.

  8. Modification of surface layers of copper under the action of the volumetric discharge initiated by an avalanche electron beam in nitrogen and CO2 at atmospheric pressure

    Science.gov (United States)

    Shulepov, M. A.; Akhmadeev, Yu. Kh.; Tarasenko, V. F.; Kolubaeva, Yu. A.; Krysina, O. V.; Kostyrya, I. D.

    2011-05-01

    The results of experimental investigations of the action of the volumetric discharge initiated by an avalanche electron beam on the surface of copper specimens are presented. The volumetric (diffuse) discharge in nitrogen and CO2 at atmospheric pressure was initiated by applying high voltage pulses of nanosecond duration to a tubular foil cathode. It has been found that the treatment of a copper surface by this type of discharge increases the hardness of the surface layer due to oxidation.

  9. The effect of frequency on NOx reduction by superimposing surface and silent discharges

    International Nuclear Information System (INIS)

    Nomura, T.; Kishida, H.; Ehara, Y.; Ito, T.

    1996-01-01

    An experimental investigation has been conducted to reduce NO from the simulated exhaust gas by superimposing discharges. In this experiment, the simulated exhaust gas closely similar to the gas exhaust from diesel engine was supplied from two gas cylinders, and the mixed gas as the model gas was used. The initial density of NO and NOx(NO+NO 2 ) were set at 1700 ppm and 1830 ppm, respectively. The reduction rate of NO at superimposed discharges is higher than that of the single discharge at the same applied voltage. The reduction rate is not dependent on frequency and decided by discharge power

  10. Response surface modelling of tool electrode wear rate and material removal rate in micro electrical discharge machining of Inconel 718

    DEFF Research Database (Denmark)

    Puthumana, Govindan

    2017-01-01

    conductivity and high strength causing it extremely difficult tomachine. Micro-Electrical Discharge Machining (Micro-EDM) is a non-conventional method that has a potential toovercome these restrictions for machining of Inconel 718. Response Surface Method (RSM) was used for modelling thetool Electrode Wear...

  11. Wire Electrical Discharge Machining of a Hybrid Composite: Evaluation of Kerf Width and Surface Roughness

    Directory of Open Access Journals (Sweden)

    Abdil KUŞ

    2016-06-01

    Full Text Available In this study, the machinability characteristics of Al/B4C-Gr hybrid composite were investigated using wire electrical discharge machining (WEDM. In the experiments, the machining parameters of wire speed, pulse-on time and pulse-off time were varied in order to explaiın their effects on machining performance, including the width of slit (kerf and surface roughness values (Rz and Rt. According to the Taguchi quality design concept, a L18 (21×32 orthogonal array was used to determine the S/N ratio, and analysis of variance (ANOVA and the F-test were used to indicate the significant machining parameters affecting the machining performance. From the ANOVA and F-test results, the significant factors were determined for each of the machining performance criteria of kerf, Rz and Rt. The variations of kerf, Rz and Rt with the machining parameters were statistically modeled via the regression analysis method. The optimum levels of the control factors for kerf, Rz and Rt were specified as A1B1C1, A1B1C2 and A1B1C2, respectively. The correlation coefficients of the predictive equations developed for kerf, Rz and Rt were calculated as 0.98, 0.828 and 0.855, respectively.

  12. Surface Modification of Asymmetric Polysulfone/Polyethylene Glycol Membranes by DC Ar-Glow Discharge Plasma

    Directory of Open Access Journals (Sweden)

    Chalad Yuenyao

    2016-01-01

    Full Text Available Polysulfone/polyethylene glycol (PSF/PEG membranes were prepared by dry/wet phase inversion method. Effects of direct current glow discharge plasma using argon as working gas on morphological structures and gas separation properties of membranes were studied. Alteration of membrane characteristics were analyzed by various techniques like contact angle, scanning electron microscope, Fourier transform infrared spectroscopy, and dynamic mechanical thermal analysis. Gas separation properties were measured in terms of permeation and ideal O2/N2 selectivity. Results showed that hydrophilic and gas separation properties of PSF/PEG membranes increased by plasma surface modification. It was also shown that the dosage of PEG and plasma treatment affected the morphological structures and mechanical and gas separation properties. The macro voids and transmembrane structure disappeared with a little amount of PEG dosage. Pore size and mechanical strength tend to decrease with increasing PEG dosage up to 10 wt%. Glass transition temperature (Tg receded from 201.8 to 143.7°C for pure PSF and PSF/PEG with PEG dosage of 10 wt%. O2 and N2 gases permeation through the 10-minute plasma treated membranes tend to increase. However, the permeation strongly dispersed when treatment time was more extended.

  13. Plasma technological effect of vacuum-arc discharge to surface of constructional materials in the presence of surface-active substances

    International Nuclear Information System (INIS)

    Arustamov, V.N.; Ashurov, Kh.B.; Kadirov, Kh. Kh.; Khudaykulov, I.Kh.

    2013-01-01

    The effect of surface-active agents, KOH, NaOH, Ba(OH)x8H 2 O and Ba(NO 2 ) 2 x2H 2 O on the mechanism of interaction of the vacuum-arc discharge to the steel surface, the specific energy consumption, plasma vacuum-arc steel sample treatment and surface roughness are considered. It is shown that the putting of the alkali solution 20% KOH and NaOH on the treated steel surface leads to the reduction of energy consumption of 1.5-2.4 times and a decrease in the surface roughness of 1.5-3.2 times. (author)

  14. Characterization of electric discharge machining, subsequent etching and shot-peening as a surface treatment for orthopedic implants

    Science.gov (United States)

    Stráský, Josef; Havlíková, Jana; Bačáková, Lucie; Harcuba, Petr; Mhaede, Mansour; Janeček, Miloš

    2013-09-01

    Presented work aims at multi-method characterization of combined surface treatment of Ti-6Al-4V alloy for biomedical use. Surface treatment consists of consequent use of electric discharge machining (EDM), acid etching and shot peening. Surface layers are analyzed employing scanning electron microscopy and energy dispersive X-ray spectroscopy. Acid etching by strong Kroll's reagent is capable of removing surface layer of transformed material created by EDM. Acid etching also creates partly nanostructured surface and significantly contributes to the enhanced proliferation of the bone cells. The cell growth could be positively affected by the superimposed bone-inspired structure of the surface with the morphological features in macro-, micro- and nano-range. Shot peening significantly improves poor fatigue performance after EDM. Final fatigue performance is comparable to benchmark electropolished material without any adverse surface effect. The proposed three-step surface treatment is a low-cost process capable of producing material that is applicable in orthopedics.

  15. Effect of electrode configuration on the uniformity of atmospheric pressure surface dielectric barrier air micro-discharge

    Science.gov (United States)

    Xia, Yang; Bi, Zhenhua; Qi, Zhihua; Ji, Longfei; Zhao, Yao; Chang, Xuewei; Wang, Wenchun; Liu, Dongping

    2018-02-01

    The electrode configuration of atmospheric pressure air discharge is one of the key elements that have significant effects on the discharge properties. In this study, double-sided printed circuit boards with square-shaped lattice structure are used to generate surface dielectric barrier air micro-discharge (SDBAMD) at atmospheric pressure. The effects of the lattice width on the discharge properties are reported. The uniformity of the SDBAMD is evaluated by adopting the digital image processing method. Our measurements show that the power and ignition voltage of the SDBAMD significantly depended on the configuration of the grounded electrode. The digital image processing results show that the uniformity of the SDBAMD is severely affected by the lattice width, and the most uniform discharge is achieved at the lattice width of 2.0 mm. The numerical model based on COMSOL demonstrated that increasing the lattice width can lead to an increase in the electric field in the vicinity of the grounded electrode and a decrease in the lattice center. Furthermore, our analysis suggests that the different electrode configurations can change the interaction between the space charges during the discharge, which ultimately affects the uniformity of the SDBAMD.

  16. Phase out of incandescent lamps

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-07-01

    Since early 2007 almost all OECD and many non-OECD governments have announced policies aimed at phasing-out incandescent lighting within their jurisdictions. This study considers the implications of these policy developments in terms of demand for regulatory compliant lamps and the capacity and motivation of the lamp industry to produce efficient lighting products in sufficient volume to meet future demand. To assess these issues, it reviews the historic international screw-based lamp market, describes the status of international phase-out policies and presents projections of anticipated market responses to regulatory requirements to determine future demand for CFLs.

  17. STUDY OF DESTRUCTION PROCESSES OF SYNTHETIC SURFACE-ACTIVE SUBSTENCES (SURFFACTANTS IN BARRIER DISCHARGE

    Directory of Open Access Journals (Sweden)

    V.I. Grinevich

    2012-06-01

    Full Text Available Kinetic data of degradation on aqueous solutions of surfactants in the plasma of barrier discharge are presented. The possible mechanism of proceeding processes is offered and considered. It is shown that the treatment in a barrier discharge results in decomposition efficiency of 95%. It is established that the main product of degradation are carboxylic acids.

  18. Novel Nanophosphors for High Efficiency Fluorescent Lamps

    Energy Technology Data Exchange (ETDEWEB)

    Alok Srivatava

    2007-03-31

    This is the Final Report of the Novel Nanophosphors for High Efficiency Fluorescent Lamps, Department of Energy (DOE). The overall goal of this three-year program is to develop novel hybrid phosphors by coating commercially available lamp phosphors with highly stable wide band-gap nanocrystalline phosphors (NCP). The prime technical approach is the development of NCP quantum-splitting phosphor (QSP) and ultra-violet (UV) emitting phosphors with quantum efficiencies exceeding that of the conventional phosphors at 185 nm. The novel hybrid phosphors will increase the efficiency of the fluorescent lamps by up to 32%, enabling total energy savings of 0.26 quads, the reduction in the U.S. energy bill by $6.5 billion and the reduction of the annual carbon emission by 4.1 billion kilogram. Our work started by investigating through modeling calculations the requirement for the particle size of the NCP. Our work to develop suitable nanocrystalline phosphors started with the known oxide quantum splitting and UV emitting phosphors. We demonstrated several synthesis techniques for the production of high quality nanocrystalline materials that crystallizes in the desired phase and with the desired particle size. In collaboration with our subcontractor we demonstrated the feasibility for the manufacture of NC phosphors. We also demonstrated novel techniques of coating the NCP on the surface of micron sized phosphors. Our chief achievement pertains to the successful testing of the coated hybrid phosphor systems in linear fluorescent lamps. In linear fluorescent lamp tests, we have demonstrated up to 7% increase in the efficacy of hybrid phosphors over the conventional (uncoated) phosphors. We have also demonstrated the improvement in the lumen maintenance of the coated phosphors. A hybrid phosphor system based on the commercial red emitting phosphor, Y{sub 2}O{sub 3}:Eu{sup 3+} did not show the anticipated improvement in lamp efficacy. We explored the reasons for this observation

  19. Highly porous micro-roughened structures developed on aluminum surface using the jet of rotating arc discharges at atmospheric pressure

    Science.gov (United States)

    Asadollahi, Siavash; Farzaneh, Masoud; Stafford, Luc

    2018-02-01

    Aluminum 6061 samples were exposed to the jet of an atmospheric pressure rotating arc discharge operated in either nitrogen or air. After multiple passes of treatment with an air-based plasma jet at very short source-to-substrate distances, scanning electron microscopy combined with x-ray photoelectron spectroscopy revealed a highly porous micro-roughened alumina-based structure on the surface of aluminum. Based on optical emission spectroscopy and high-speed optical imaging of the jet interacting with aluminum samples, it was found that the process is mainly driven by the energy transfer from the plasma source to the surface through transient plasma-transferred arcs. The occurrence of multiple arc discharges over very short time scales can induce rapid phase transformations of aluminum with characteristics similar to the ones usually observed during laser ablation of materials with femto- to nanosecond laser pulses or during the formation of cathode spots on the surface of metals.

  20. Anu Lamp / [vestelnud Kalju Orro

    Index Scriptorium Estoniae

    Lamp, Anu, 1958-

    2007-01-01

    Lavakunstikooli sisseastumisest, õppimisest, õpetajatest ja õpetamisest. Anu Lamp õppis Lavakunstikoolis 10. lennus (1978-1982). Osalenud samas lavakõne õppejõuna 18.-23. lennu ja erialaõppejõuna 20. lennu töös

  1. Deactivation of Streptococcus mutans Biofilms on a Tooth Surface Using He Dielectric Barrier Discharge at Atmospheric Pressure

    Science.gov (United States)

    Imola, Molnar; Judit, Papp; Alpar, Simon; Sorin, Dan Anghel

    2013-06-01

    This paper presents a study of the effect of the low temperature atmospheric helium dielectric barrier discharge (DBD) on the Streptococcus mutans biofilms formed on tooth surface. Pig jaws were also treated by plasma to detect if there is any harmful effect on the gingiva. The plasma was characterized by using optical emission spectroscopy. Experimental data indicated that the discharge is very effective in deactivating Streptococcus mutans biofilms. It can destroy them with an average decimal reduction time (D-time) of 19 s and about 98% of them were killed after a treatment time of 30 s. According to the survival curve kinetic an overall 32 s treatment time would be necessary to perform a complete sterilization. The experimental results presented in this study indicated that the helium dielectric barrier discharge, in plan-parallel electrode configuration, could be a very effective tool for deactivation of oral bacteria and might be a promising technique in various dental clinical applications.

  2. Deactivation of Streptococcus mutans Biofilms on a Tooth Surface Using He Dielectric Barrier Discharge at Atmospheric Pressure

    International Nuclear Information System (INIS)

    Molnar Imola; Papp Judit; Simon Alpar; Anghel Sorin Dan

    2013-01-01

    This paper presents a study of the effect of the low temperature atmospheric helium dielectric barrier discharge (DBD) on the Streptococcus mutans biofilms formed on tooth surface. Pig jaws were also treated by plasma to detect if there is any harmful effect on the gingiva. The plasma was characterized by using optical emission spectroscopy. Experimental data indicated that the discharge is very effective in deactivating Streptococcus mutans biofilms. It can destroy them with an average decimal reduction time (D-time) of 19 s and about 98% of them were killed after a treatment time of 30 s. According to the survival curve kinetic an overall 32 s treatment time would be necessary to perform a complete sterilization. The experimental results presented in this study indicated that the helium dielectric barrier discharge, in plan-parallel electrode configuration, could be a very effective tool for deactivation of oral bacteria and might be a promising technique in various dental clinical applications.

  3. Thermal and induced flow characteristics of radio frequency surface dielectric barrier discharge plasma actuation at atmospheric pressure

    International Nuclear Information System (INIS)

    Wang Wei-long; Li Jun; Song Hui-min; Jin Di; Jia Min; Wu Yun

    2017-01-01

    Thermal and induced flow velocity characteristics of radio frequency (RF) surface dielectric barrier discharge (SDBD) plasma actuation are experimentally investigated in this paper. The spatial and temporal distributions of the dielectric surface temperature are measured with the infrared thermography at atmospheric pressure. In the spanwise direction, the highest dielectric surface temperature is acquired at the center of the high voltage electrode, while it reduces gradually along the chordwise direction. The maximum temperature of the dielectric surface raises rapidly once discharge begins. After several seconds (typically 100 s), the temperature reaches equilibrium among the actuator’s surface, plasma, and surrounding air. The maximum dielectric surface temperature is higher than that powered by an AC power supply in dozens of kHz. Influences of the duty cycle and the input frequency on the thermal characteristics are analyzed. When the duty cycle increases, the maximum dielectric surface temperature increases linearly. However, the maximum dielectric surface temperature increases nonlinearly when the input frequency varies from 0.47 MHz to 1.61 MHz. The induced flow velocity of the RF SDBD actuator is 0.25 m/s. (paper)

  4. Surface-wave sustained plasmas: Toward a better understanding of RF and microwave discharges

    Energy Technology Data Exchange (ETDEWEB)

    Moisan, M. [Groupe de physique des plasmas, Universite de Montreal, Montreal H3C 3J7, Quebec (Canada); Ferreira, C.M. [Centro de Electrodinamica da Universidade Tecnica de Lisboa, Instituto Superior Tecnico, Lisboa 1000 (Portugal); Hubert, J.; Margot, J. [Groupe de physique des plasmas, Universite de Montreal, Montreal H3C 3J7, Quebec (Canada); Zakrzewski, Z. [Polish Academy of Sciences, IMP-PAN, 80-952 Gdansk (Poland)

    1996-03-01

    An approach is presented that unifies the description of the various existing RF and microwave discharges. It is based on two essential facts: (i) it is not the spatial distribution of the high frequency (HF) electric field intensity but its spatial average that plays in the power transfer to the plasma; (ii) the power {theta} required to maintain an electron in the discharge is governed by charged particle losses, which are independent of the HF E-field. This enables one to model separately the maintenance processes of HF discharges and the electrodynamic properties of HF circuits sustaining the plasma, although the discharge and the HF field are actually coupled self-consistently. The influence of the field frequency on the properties of these plasmas is also summarized. {copyright} {ital 1996 American Institute of Physics.}

  5. Microhollow Glow Discharge Instrument for In Situ Lunar Surface Measurements, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Makel Engineering, Inc. (MEI) and Penn State University (PSU) propose to develop a highly sensitive spectrometer based on glow discharge plasma emission for the...

  6. Effect of electrical discharge machining on surface characteristics and machining damage of AISI D2 tool steel

    International Nuclear Information System (INIS)

    Guu, Y.H.; Hocheng, H.; Chou, C.Y.; Deng, C.S.

    2003-01-01

    In this work the electrical discharge machining (EDM) of AISI D2 tool steel was investigated. The surface characteristics and machining damage caused by EDM were studied in terms of machining parameters. Based on the experimental data, an empirical model of the tool steel was also proposed. A new damage variable was used to study the EDM damage. The workpiece surface and re-solidified layers were examined by a scanning electron microscopy. Surface roughness was determined with a surface profilometer. The residual stress acting on the EDM specimen was measured by the X-ray diffraction technique. Experimental results indicate that the thickness of the recast layer, and surface roughness are proportional to the power input. The EDM process introduces tensile residual stress on the machined surface. The EDM damage leads to strength degradation

  7. Development and Experimental Study of Surface-Electrical Discharge Diamond Grinding of Al-10 wt%SiC Composite

    Science.gov (United States)

    Agrawal, Shyam Sunder; Yadava, Vinod

    2016-01-01

    As silicon carbide possesses small fracture toughness, it is difficult to grind because it leads to cracking. Metal matrix composites can be machined using electrical discharge machining (EDM) but the process is slow. Electrical discharge diamond grinding (EDDG), which consists of diamond grinding and EDM with a rotating disk which enhanced material removal rate (MRR) and produce better surface finish. This paper describes the machining characteristic of Al-SiC composite using EDDG in surface grinding configuration which is called as surface-electrical discharge diamond grinding (S-EDDG). A chain of experiments were performed on S-EDDG set up by mounting newly self designed and fabricated set up on conventional die sinking EDM machine using the approach of one parameter-at-a-time concept. Surface roughness (Ra) and MRR are taken as output parameters as both are important outcome in the manufacturing process and they materialize a major division in the manufacturing system. The effects of current, wheel speed and depth of cut is analyzed on MRR and Ra. Finally, optimization have been done through weighted principal component analysis.

  8. Effect of water-surface discharge on the inactivation of Bacillus subtilis due to protein lysis and DNA damage.

    Science.gov (United States)

    Kadowaki, Kazunori; Sone, Toshifumi; Kamikozawa, Takashi; Takasu, Hiroyuki; Suzuki, Satoru

    2009-09-01

    The effect of water-surface discharge on the inactivation of Bacillus subtilis ATCC6633 in water was examined by using a very short high-voltage pulse generator. The surviving number of spore cells at 10(4) CFU/ml in initial concentration exponentially decreased with increasing discharge-treatment time. The input energy into the water-surface discharge under an O(2) gas flow for reduction in the survival number to 10% was lower than that under an air flow because many oxidation agents such as ozone and OH radical were produced under the O(2) gas flow. The input energy density for the one-tenth reduction depended not only on the spore state but also on the initial cell concentration. The input energy for the high-concentration spore cells (10(7) CFU/ml) was much higher than that for the low-concentration spore cells (10(4) CFU/ml). Cellular proteins and DNA were degraded by a 30-min discharge treatment of vegetative cells, whereas DNA of the high-concentration spore cells was relatively resistant.

  9. Slit-lamp photography and videography with high magnifications

    Science.gov (United States)

    Yuan, Jin; Jiang, Hong; Mao, Xinjie; Ke, Bilian; Yan, Wentao; Liu, Che; Cintrón-Colón, Hector R; Perez, Victor L; Wang, Jianhua

    2015-01-01

    Purpose To demonstrate the use of the slit-lamp photography and videography with extremely high magnifications for visualizing structures of the anterior segment of the eye. Methods A Canon 60D digital camera with Movie Crop Function was adapted into a Nikon FS-2 slit-lamp to capture still images and video clips of the structures of the anterior segment of the eye. Images obtained using the slit-lamp were tested for spatial resolution. The cornea of human eyes was imaged with the slit-lamp and the structures were compared with the pictures captured using the ultra-high resolution optical coherence tomography (UHR-OCT). The central thickness of the corneal epithelium and total cornea was obtained using the slit-lamp and the results were compared with the thickness obtained using UHR-OCT. Results High-quality ocular images and higher spatial resolutions were obtained by using the slit-lamp with extremely high magnifications and Movie Crop Function, rather than the traditional slit-lamp. The structures and characteristics of the cornea, such as the normal epithelium, abnormal epithelium of corneal intraepithelial neoplasia, LASIK interface, and contact lenses, were clearly visualized using this device. These features were confirmed by comparing the obtained images with those acquired using UHR-OCT. Moreover, the tear film debris on the ocular surface and the corneal nerve in the anterior corneal stroma were also visualized. The thicknesses of the corneal epithelium and total cornea were similar to that measured using UHR-OCT (P photography and videography with extremely high magnifications allows better visualization of the anterior segment structures of the eye, especially of the epithelium, when compared with the traditional slit-lamp. PMID:26020484

  10. Color Degradation of Textiles with Natural Dyes and of Blue Scale Standards Exposed to White LED Lamps:Evaluation of White LED Lamps for Effectiveness as Museum Lighting

    Science.gov (United States)

    Ishii, Mie; Moriyama, Takayoshi; Toda, Masahiro; Kohmoto, Kohtaro; Saito, Masako

    White light-emitting diodes (LED) are well suited for museum lighting because they emit neither UV nor IR radiation, which damage artifacts. The color degradation of natural dyes and blue scale standards (JIS L 0841) by white LED lamps are examined, and the performance of white LED lamps for museum lighting is evaluated. Blue scale standard grades 1-6 and silk fabrics dyed with 22 types of natural dyes classified as mid to highly responsive in a CIE technical report (CIE157:2004) were exposed to five types of white LED lamps using different luminescence methods and color temperatures. Color changes were measured at each 15000 lx·hr (500 lx at fabric surface × 300 hr) interval ten times. The accumulated exposure totaled 150000 lx·hr. The data on conventional white LED lamps and previously reported white fluorescent (W) and museum fluorescent (NU) lamps was evaluated. All the white LED lamps showed lower fading rates compared with a W lamp on a blue scale grade 1. The fading rate of natural dyes in total was the same between an NU lamp (3000 K) and a white LED lamp (2869 K). However, yellow natural dyes showed higher fading rates with the white LED lamp. This tendency is due to the high power characteristic of the LED lamp around 400-500 nm, which possibly contributes to the photo-fading action on the dyes. The most faded yellow dyes were Ukon (Curcuma longa L.) and Kihada (Phellodendron amurense Rupr.), and these are frequently used in historic artifacts such as kimono, wood-block prints, and scrolls. From a conservation point of view, we need to continue research on white LED lamps for use in museum lighting.

  11. Analysis of Effects of Cutting Parameters of Wire Electrical Discharge Machining on Material Removal Rate and Surface Integrity

    Science.gov (United States)

    Tonday, H. R.; Tigga, A. M.

    2016-02-01

    As wire electrical discharge machining is pioneered as a vigorous, efficient and precise and complex nontraditional machining technique, research is needed in this area for efficient machining. In this paper, the influence of various input factors of wire electrical discharge machining (WEDM) on output variable has been analyzed by using Taguchi technique and analysis of variance. The design of experiments has been done and by applying L8 orthogonal arrays method and experiments have been conducted and collected required data. The objectives of the research are to maximize the material removal rate and to minimize the surface roughness value (Ra). Surface morphology of machined workpiece has been obtained and examined by employing scanning electron microscopy (SEM) technique.

  12. Analysis of Effects of Cutting Parameters of Wire Electrical Discharge Machining on Material Removal Rate and Surface Integrity

    International Nuclear Information System (INIS)

    Tonday, H. R.; Tigga, A. M.

    2016-01-01

    As wire electrical discharge machining is pioneered as a vigorous, efficient and precise and complex nontraditional machining technique, research is needed in this area for efficient machining. In this paper, the influence of various input factors of wire electrical discharge machining (WEDM) on output variable has been analyzed by using Taguchi technique and analysis of variance. The design of experiments has been done and by applying L8 orthogonal arrays method and experiments have been conducted and collected required data. The objectives of the research are to maximize the material removal rate and to minimize the surface roughness value (Ra). Surface morphology of machined workpiece has been obtained and examined by employing scanning electron microscopy (SEM) technique. (paper)

  13. Surface treatment by electric discharge machining of Ti–6Al–4V alloy for potential application in orthopaedics

    Czech Academy of Sciences Publication Activity Database

    Harcuba, P.; Bačáková, Lucie; Stráský, J.; Bačáková, Markéta; Novotná, Katarína; Janeček, M.

    2012-01-01

    Roč. 7, MAR (2012), s. 96-105 ISSN 1751-6161. [Symposium on Biological Materials Science /7./. San Diego, 27.02.2011-03.03.2011] R&D Projects: GA TA ČR(CZ) TA01011141 Institutional research plan: CEZ:AV0Z50110509 Keywords : electric discharge machining * surface roughness * mechanical properties Subject RIV: FI - Traumatology, Orthopedics Impact factor: 2.368, year: 2012

  14. Research on Modern Gas Discharge Light Sources

    Science.gov (United States)

    Born, M.; Markus, T.

    This article gives an overview of today's gas discharge light sources and their application fields with focus on research aspects. In Sect. 15.1 of this chapter, an introduction to electric light sources, the lighting market and related research topics is outlined. Due to the complexity of the subject, we have focused on selected topics in the field of high intensity discharge (HID) lamps since these represent an essential part of modern lamp research. The working principle and light technical properties of HID lamps are described in Sect. 15.2. Physical and thermochemical modelling procedures and tools as well as experimental analysis are discussed in Sects. 15.3 and 15.4, respectively. These tools result in a detailed scientific insight into the complexity of real discharge lamps. In particular, analysis and modelling are the keys for further improvement and development of existing and new products.

  15. Combustion of methane-oxygen and methane-oxygen-CFC mixtures initiated by a high-current slipping surface discharge

    International Nuclear Information System (INIS)

    Kossyi, I.A.; Silakov, V.P.; Tarasova, N.M.

    2001-01-01

    Results are presented from experimental studies of the destruction of chlorofluorocarbon (CF 2 Cl 2 ) molecules in a methane-oxygen (air) gas mixture whose combustion is initiated by a high-current slipping surface discharge. It is found that a three-component CH 4 + O 2 (air)+ CF 2 Cl 2 gas mixture (even with a considerable amount of the third component) demonstrates properties of explosive combustion involving chain reactions that are typical of two-component CH 4 + O 2 mixtures. Experiments show the high degree of destruction (almost complete decomposition) of chlorofluorocarbons contained in the mixture during one combustion event. The combustion dynamics is studied. It is shown that the combustion initiated by a slipping surface discharge has a number of characteristic features that make it impossible to identify the combustion dynamics with the formation of a combustion or detonation wave. The features of the effects observed can be related to intense UV radiation produced by a pulsed high-current surface discharge

  16. Spatial-temporal evolution of self-organized loop-patterns on a water surface and a diffuse discharge in the gap

    Science.gov (United States)

    Li, Xuechen; Geng, Jinling; Jia, Pengying; Zhang, Panpan; Zhang, Qi; Li, Yaru

    2017-11-01

    Excited by an alternating current voltage, a patterned discharge and a diffuse discharge are generated in a needle to liquid configuration. Using an intensified charge-coupled device (ICCD), temporal evolution of the discharge between the two electrodes is investigated for the diffuse mode and the patterned mode, respectively. For the diffuse mode, the positive discharge is in a glow regime, and the negative discharge is in a Townsend discharge regime. For the patterned mode, the discharge always belongs to the Townsend discharge regime. Moreover, in the patterned mode, various patterns including the single loop, single loop with the surrounding corona, triple loops, and concentric loops with a central spot are observed on the water surface with the increasing positive peak-value of the applied voltage (Upp). Temporally resolved images of the loop-patterns are captured on the water surface. From the electrical measurements and the ICCD imaging, it is found that the loop pattern emerges after the discharge bridges the two electrodes. Then, it begins to evolve and finally degenerates with the decrease in the discharge current. The pattern does not disappear until the discharge quenches. Formation of the loop-patterns is attributed to the role of negative ions.

  17. Stress response of Escherichia coli induced by surface streamer discharge in humid air

    Czech Academy of Sciences Publication Activity Database

    Doležalová, Eva; Prukner, Václav; Lukeš, Petr; Šimek, Milan

    2016-01-01

    Roč. 49, č. 7 (2016), č. článku 075401. ISSN 0022-3727 R&D Projects: GA MŠk(CZ) LD13010; GA MŠk(CZ) LD14080 Grant - others:European Cooperation in Science and Technology(XE) COST MP1101 Program:Materials, Physical and Nanosciences COST Action MP1101 Institutional support: RVO:61389021 Keywords : bacterial activity * culturability * dielectric barrier discharges (DBD) * lipid peroxidation * stress Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 2.588, year: 2016 http://iopscience.iop.org/article/10.1088/0022-3727/49/7/075401/meta

  18. Stress response of Escherichia coli induced by surface streamer discharge in humid air

    Czech Academy of Sciences Publication Activity Database

    Doležalová, Eva; Prukner, Václav; Lukeš, Petr; Šimek, Milan

    2016-01-01

    Roč. 49, č. 7 (2016), s. 075401 ISSN 0022-3727 R&D Projects: GA MŠk(CZ) LD13010; GA MŠk(CZ) LD14080 Grant - others:European Cooperation in Science and Technology(XE) COST MP1101 Program:Materials, Physical and Nanosciences COST Action MP1101 Institutional support: RVO:61389021 Keywords : bacterial activity * culturability * dielectric barrier discharges (DBD) * lipid peroxidation * stress Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 2.588, year: 2016 http://iopscience.iop.org/article/10.1088/0022-3727/49/7/075401/meta

  19. Definition of groundwater recharge and discharge zones through surface indicators: Centre-South of the Mesa Central, Mexico

    Directory of Open Access Journals (Sweden)

    Liliana Andrea Peñuela Arévalo

    2013-02-01

    Full Text Available The aim of this paper is the delimitation of groundwater recharge and discharge zones in the centresouth portion of the Mesa Central. This was achieved using groundwater flow systems theory, which has proved to be a valuable tool since it considers a systemic perspective of the environment, integrating several natural elements. There are various physical, chemical and biological processes generated in the subsoil within which groundwater is incorporated. This involvement is caused by the natural gravitational movement of groundwater which is manifested on the surface by contrasting evidences in the recharge and discharge zones. Therefore, the objective of this paper includes the demonstration of the usefulness of the analysis of those indicators to locate priority areas and also provides an approximation of groundwater functioning. The definition of recharge and discharge zones included the analysis of maps describing soil type, vegetation, topographic elevation, groundwater flowpath direction, springs, and presence of natural water bodies. Such analysis was carried out through the overlaying tool of ArcMap™ software. The results suggest that the highlands of Fría, San Miguelito and Santa Bárbara as recharge zones. Natural discharge zones were originally present in the plain of the Aguascalientes tectonic depression, and some flat and topographic low zones in the vicinity of Altos de Jalisco, Santa María del Río and Ojuelos.

  20. Hydrophylisation of non-woven polypropylene textiles using atmospheric pressure surface barrier discharge

    Czech Academy of Sciences Publication Activity Database

    Sťahel, P.; Buršíková, V.; Buršík, Jiří; Čech, J.; Janča, J.; Čermák, M.

    2008-01-01

    Roč. 10, č. 1 (2008), s. 213-218 ISSN 1454-4164 Institutional research plan: CEZ:AV0Z20410507 Keywords : hydrophylisation * non - woven * polypropylene textiles Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 0.577, year: 2008

  1. Suspended particle and pathogen peak discharge buffering by a surface-flow constructed wetland

    NARCIS (Netherlands)

    Mulling, B.T.M.; van den Boomen, R.M.; van der Geest, H.G.; Kappelhof, J.W.N.M.; Admiraal, W.

    2013-01-01

    Constructed wetlands (CWs) have been shown to improve the water quality of treated wastewater. The capacity of CWs to reduce nutrients, pathogens and organic matter and restore oxygen regime under normal operating conditions cannot be extrapolated to periods of incidental peak discharges. The

  2. A survey of infrared continuum versus line radiation from metal halide lamps

    International Nuclear Information System (INIS)

    Kato, M; Herd, M T; Lawler, J E

    2008-01-01

    Near-infrared radiation (near-IR) losses from the arcs of six commercial metal halide high intensity discharge (MH-HID) lamps with various power levels and with both Na/Sc and rare earth doses were surveyed in this paper. A radiometrically calibrated Fourier transform infrared spectrometer was used. Lamps with rare earth doses have appreciably better color rendering indices (CRIs) than lamps with Na/Sc doses. The ratios of near-IR continuum emission over near-IR line emission from these six lamps were compared. The near-IR continuum dominates near-IR losses from lamps with rare earth doses and the continuum is significant, but not dominant, from lamps with Na/Sc doses. There was no strong dependence of this ratio on input power or color temperature (T c ). Total near-IR losses were estimated using absolutely calibrated, horizontal irradiance measurements. Estimated total near-IR losses were correlated with CRI. The lamps with rare earth doses yield the best CRIs, but have appreciably higher near-IR losses due primarily to continuum processes. One of these rare earth MH-HID lamps was used in a more detailed study of the microscopic physics of the continuum mechanism (Herd M T and Lawler E 2007 J. Phys. D: Appl. Phys. 40 3386)

  3. Surface treatment by electric discharge machining of Ti-6Al-4V alloy for potential application in orthopaedics.

    Science.gov (United States)

    Harcuba, Petr; Bačáková, Lucie; Stráský, Josef; Bačáková, Markéta; Novotná, Katarína; Janeček, Miloš

    2012-03-01

    This study investigated the properties of Ti-6Al-4V alloy after surface treatment by the electric discharge machining (EDM) process. The EDM process with high peak currents proved to induce surface macro-roughness and to cause chemical changes to the surface. Evaluations were made of the mechanical properties by means of tensile tests, and of surface roughness for different peak currents of the EDM process. The EDM process with peak current of 29 A was found to induce sufficient surface roughness, and to have a low adverse effect on tensile properties. The chemical changes were studied by scanning electron microscopy equipped with an energy dispersive X-ray analyser (EDX). The surface of the benchmark samples was obtained by plasma-spraying a titanium dioxide coating. An investigation of the biocompatibility of the surface-treated Ti-6Al-4V samples in cultures of human osteoblast-like MG 63 cells revealed that the samples modified by EDM provided better substrates for the adhesion, growth and viability of MG 63 cells than the TiO2 coated surface. Thus, EDM treatment can be considered as a promising surface modification to orthopaedic implants, in which good integration with the surrounding bone tissue is required. Copyright © 2011 Elsevier Ltd. All rights reserved.

  4. Bioactive surface modifications on inner walls of poly-tetra-fluoro-ethylene tubes using dielectric barrier discharge

    International Nuclear Information System (INIS)

    Cho, Yong Ki; Park, Daewon; Kim, Hoonbae; Lee, Hyerim; Park, Heonyong; Kim, Hong Ja; Jung, Donggeun

    2014-01-01

    Graphical abstract: - Highlights: • The surface modification of the inner walls of poly-tetra-fluoro-ethylene (PTFE) tubing was carried out to improve vascular grafts. • Focus was centered on the cell attachment of the inner wall of the PTFE by sequential processes of hydrogen plasma treatment, hydrocarbon deposition, and reactive plasma treatment using micro plasma discharge. - Abstract: Bioactive surface modification can be used in a variety of medical polymeric materials in the fields of biochips and biosensors, artificial membranes, and vascular grafts. In this study, the surface modification of the inner walls of poly-tetra-fluoro-ethylene (PTFE) tubing was carried out to improve vascular grafts, which are made of biocompatible material for the human body in the medical field. Focus was centered on the cell attachment of the inner wall of the PTFE by sequential processes of hydrogen plasma treatment, hydrocarbon deposition, and reactive plasma treatment on the PFTE surface using micro plasma discharge. Micro plasma was generated by a medium-frequency alternating current high-voltage generator. The preliminary modification of PTFE was conducted by a plasma of hydrogen and argon gases. The hydrocarbon thin film was deposited on modified PTFE with a mixture of acetylene and argon gases. The reactive plasma treatment using oxygen plasma was done to give biocompatible functionality to the inner wall surface. The hydrophobic surface of bare PTFE is made hydrophilic by the reactive plasma treatment due to the formation of carbonyl groups on the surface. The reactive treatment could lead to improved attachment of smooth muscle cells (SMCs) on the modified PTFE tubing. Fourier transform infrared absorption spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, and water contact angle measurement were used for the analysis of the surface modification. The SMC-attached PTFE tube developed will be applicable to in vitro human vasculature

  5. Enhancement of Osteoblastic-Like Cell Activity by Glow Discharge Plasma Surface Modified Hydroxyapatite/β-Tricalcium Phosphate Bone Substitute

    Directory of Open Access Journals (Sweden)

    Eisner Salamanca

    2017-11-01

    Full Text Available Glow discharge plasma (GDP treatments of biomaterials, such as hydroxyapatite/β-tricalcium phosphate (HA/β-TCP composites, produce surfaces with fewer contaminants and may facilitate cell attachment and enhance bone regeneration. Thus, in this study we used argon glow discharge plasma (Ar-GDP treatments to modify HA/β-TCP particle surfaces and investigated the physical and chemical properties of the resulting particles (HA/β-TCP + Ar-GDP. The HA/β-TCP particles were treated with GDP for 15 min in argon gas at room temperature under the following conditions: power: 80 W; frequency: 13.56 MHz; pressure: 100 mTorr. Scanning electron microscope (SEM observations showed similar rough surfaces of HA/β-TCP + Ar-GDP HA/β-TCP particles, and energy dispersive spectrometry analyses showed that HA/β-TCP surfaces had more contaminants than HA/β-TCP + Ar-GDP surfaces. Ca/P mole ratios in HA/β-TCP and HA/β-TCP + Ar-GDP were 1.34 and 1.58, respectively. Both biomaterials presented maximal intensities of X-ray diffraction patterns at 27° with 600 a.u. At 25° and 40°, HA/β-TCP + Ar-GDP and HA/β-TCP particles had peaks of 200 a.u., which are similar to XRD intensities of human bone. In subsequent comparisons, MG-63 cell viability and differentiation into osteoblast-like cells were assessed on HA/β-TCP and HA/β-TCP + Ar-GDP surfaces, and Ar-GDP treatments led to improved cell growth and alkaline phosphatase activities. The present data indicate that GDP surface treatment modified HA/β-TCP surfaces by eliminating contaminants, and the resulting graft material enhanced bone regeneration.

  6. 30 CFR 75.1719-4 - Mining machines, cap lamps; requirements.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Mining machines, cap lamps; requirements. 75... Mining machines, cap lamps; requirements. (a) Paint used on exterior surfaces of mining machines shall... frames or reflecting tape shall be installed on each end of mining machines, except that continuous...

  7. The study of contamination of discharged runoff from surface water disposal channels of Bushehr city in 2012-2013

    Directory of Open Access Journals (Sweden)

    Vaheid Noroozi-Karbasdehi

    2016-09-01

    Full Text Available Background: In coastal cities, wastewater discharge into the sea is one of the options for sewage disposal that in case of non-compliance with health standards  in wastewater disposal will be led to the spread of infection and disease. On the other hand, water resources preservation and using them efficiently are the principles of sustainable development of each country. This study was aimed to investigate the contamination of discharged runoff from the surface water disposal channels of Bushehr city in 2012 - 13. Materials and Methods: In this study, Sampling was conducted by composite sampling method from output of the five main surface water disposal channels leading to the Persian Gulf located in the coastal region of Bushehr city during two seasons including wet (winter and dry (summer in 2012- 13. Then, experimental tests of BOD5, total coliform and fecal coliform were done on any of the 96 samples according to the standard method. Results: Analysis of the data showed that the BOD5, total coliform and fecal coliform of effluent runoff of the channels were more than the national standard output of disposal wastewaters into the surface waters, and the highest and lowest amount of BOD5 which obtained were 160 mg/L and 28 mg/L, respectively. Conclusion: considering the fact that discharged runoff from surface water disposal channels link from shoreline to sea in close distance and they often are as natural swimming sites and even fishing sites of Bushehr city, and also according to high level of organic and bacterial load of these channels, it is urgently required to be considered by the authorities.

  8. Reduction of microbial contamination and improvement of germination of sweet basil (Ocimum basilicum L.) seeds via surface dielectric barrier discharge

    Science.gov (United States)

    Ambrico, Paolo F.; Šimek, Milan; Morano, Massimo; De Miccolis Angelini, Rita M.; Minafra, Angelantonio; Trotti, Pasquale; Ambrico, Marianna; Prukner, Václav; Faretra, Francesco

    2017-08-01

    Naturally contaminated basil seeds were treated by a surface dielectric barrier discharge driven in the humid air by an amplitude modulated AC high voltage to avoid heat shock. In order to avoid direct contact of seeds with microdischarge filaments, the seeds to be treated were placed at sufficient distance from the surface discharge. After treatment, the seeds were analyzed in comparison with control samples for their microbial contamination as well as for the capability of germination and seedling growth. Moreover, chemical modification of seed surface was observed through the elemental energy dispersive x-ray analysis and wettability tests. We found that treatment applied at 20% duty cycle (effective discharge duration up to 20 s) significantly decreases microbial load without reducing the viability of the seeds. On the other side, seedling growth was considerably accelerated after the treatment, and biometric growth parameters of seedlings (total length, weight, leaf extension) considerably increased compared to the controls. Interestingly, scanning electron microscopy images taken for the different duration of treatment revealed that seed radicle micropylar regions underwent significant morphological changes while the coat was substantially undamaged. Inside the seed, the embryo seemed to be well preserved while the endosperm body was detached from the epithelial tegument. A total of 9 different genera of fungi were recovered from the analyzed seeds. Scanning electron microscopy images revealed that conidia were localized especially in the micropylar region, and after plasma treatment, most of them showed substantial damages. Therefore, the overall effect of the treatment of naturally contaminated seeds by reactive oxygen and nitrogen species produced by plasma and the consequent changes in surface chemistry and microbial load can significantly improve seed vigor.

  9. Low Pressure DC Glow Discharge Air Plasma Surface Treatment of Polyethylene (PE) Film for Improvement of Adhesive Properties

    International Nuclear Information System (INIS)

    Pandiyaraj, Krishnasamy Navaneetha; Yoganand, Paramasivam; Selvarajan, Vengatasamy; Deshmukh, Rajendrasing R.; Balasubramanian, Suresh; Maruthamuthu, Sundaram

    2013-01-01

    The present work deals with the change in surface properties of polyethylene (PE) film using DC low pressure glow discharge air plasma and makes it useful for technical applications. The change in hydrophilicity of the modified PE film surface was investigated by measuring contact angle and surface energy as a function of exposure time. Changes in the morphological and chemical composition of PE films were analyzed by atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). The improvement in adhesion was studied by measuring T-peel and lap-shear strength. The results show that the wettability and surface energy of the PE film has been improved due to the introduction of oxygen-containing polar groups and an increase in surface roughness. The XPS result clearly shows the increase in concentration of oxygen content and the formation of polar groups on the polymer surface. The AFM observation on PE film shows that the roughness of the surface increased due to plasma treatment. The above morphological and chemical changes enhanced the adhesive properties of the PE film surfaces, which was confirmed by T-peel and lap-shear tests.

  10. Continuous measurements of water surface height and width along a 6.5km river reach for discharge algorithm development

    Science.gov (United States)

    Tuozzolo, S.; Durand, M. T.; Pavelsky, T.; Pentecost, J.

    2015-12-01

    The upcoming Surface Water and Ocean Topography (SWOT) satellite will provide measurements of river width and water surface elevation and slope along continuous swaths of world rivers. Understanding water surface slope and width dynamics in river reaches is important for both developing and validating discharge algorithms to be used on future SWOT data. We collected water surface elevation and river width data along a 6.5km stretch of the Olentangy River in Columbus, Ohio from October to December 2014. Continuous measurements of water surface height were supplemented with periodical river width measurements at twenty sites along the study reach. The water surface slope of the entire reach ranged from during 41.58 cm/km at baseflow to 45.31 cm/km after a storm event. The study reach was also broken into sub-reaches roughly 1km in length to study smaller scale slope dynamics. The furthest upstream sub-reaches are characterized by free-flowing riffle-pool sequences, while the furthest downstream sub-reaches were directly affected by two low-head dams. In the sub-reaches immediately upstream of each dam, baseflow slope is as low as 2 cm/km, while the furthest upstream free-flowing sub-reach has a baseflow slope of 100 cm/km. During high flow events the backwater effect of the dams was observed to propagate upstream: sub-reaches impounded by the dams had increased water surface slopes, while free flowing sub-reaches had decreased water surface slopes. During the largest observed flow event, a stage change of 0.40 m affected sub-reach slopes by as much as 30 cm/km. Further analysis will examine height-width relationships within the study reach and relate cross-sectional flow area to river stage. These relationships can be used in conjunction with slope data to estimate discharge using a modified Manning's equation, and are a core component of discharge algorithms being developed for the SWOT mission.

  11. Automotive LED lamp lighted appearance

    Science.gov (United States)

    Conn, Lawrence G.; Bennett, Larry R.

    2001-05-01

    The automotive optical engineer has an entirely new set of rules to follow for a 'smooth lighted appearance' with the introduction of LEDs into the automotive signal lighting market. To move away from the 'polka-dot' appearance long associated with the usage of LEDs as the light source for automotive lighting, and give the consumer a smooth lighted appearance to his lamp, there are several optical parameters that must be observed. The number and type of LEDs used, the size of the optical elements used, the spacing of the optical elements, plus many other factors all play a critical role and must be considered in the solution to the 'smooth lighted appearance' in an automotive signal lamp. The 'smooth lighted appearance' in an automotive signal lamp has long been a difficult problem to which there is more than one solution. The most visually pleasing and effective solution is not always the most easily obtainable solution since photometry requirements and smooth lighted appearance can be diametric goals. Subsequently the most cost effective and the easily 'doable' solution may not give the ultimate in aesthetically pleasing results for the consumer. Therefore, it is the purpose and intent of this paper to outline the parameters that need to be considered to obtain a 'smooth lighted appearance' for an automotive signal lamp, and to clarify the methods and 'tools' that are required to meet this goal.

  12. Effects of electrical discharge surface modification of superalloy Haynes 230 with aluminum and molybdenum on oxidation behavior

    International Nuclear Information System (INIS)

    Bai, C.-Y.

    2007-01-01

    The effects of the electrical discharge alloying (EDA) process on improving the high temperature oxidation resistance of the Ni-based superalloy Haynes 230 have been investigated. The 85 at.% Al and 15 at.% Mo composite electrode provided the surface alloying materials. An Al-rich layer is produced on the surface of the EDA specimen alloyed with positive electrode polarity, whereas, many discontinuous piled layers are attached to the surface of the EDA superalloy when negative electrode polarity is selected. The oxidation resistance of the specimen alloyed with positive electrode polarity is better than that of the unalloyed superalloy, and the effective temperature of oxidation resistance of the alloyed layer can be achieved to 1100 o C. Conversely, the oxidation resistance of the other EDA specimen alloyed with negative electrode polarity is even worse than that of the unalloyed superalloy

  13. Determination of the cathode and anode voltage drops in high power low-pressure amalgam lamps

    Energy Technology Data Exchange (ETDEWEB)

    Vasilyak, L. M., E-mail: vasilyak@ihed.ras.ru [Russian Academy of Sciences, Joint Institute for High Temperatures (Russian Federation); Vasiliev, A. I., E-mail: vasiliev@npo.lit.ru; Kostyuchenko, S. V.; Sokolov, D. V.; Startsev, A. Yu. [Joint Stock Company NPO LIT (Russian Federation); Kudryavtsev, N. N. [Moscow Institute of Physics and Technology (State University) (Russian Federation)

    2011-12-15

    For the first time, cathode and anode drops of powerful low-pressure amalgam lamps were measured. The lamp discharge current is 3.2 A, discharge current frequency is 43 kHz, linear electric power is 2.4 W/cm. The method of determination of a cathode drop is based on the change of a lamp operating voltage at variation of the electrode filament current at constant discharge current. The total (cathode plus anode) drop of voltage was measured by other, independent ways. The maximum cathode fall is 10.8 V; the anode fall corresponding to the maximal cathode fall is 2.4 V. It is shown that in powerful low pressure amalgam lamps the anode fall makes a considerable contribution (in certain cases, the basic one) to heating of electrodes. Therefore, the anode fall cannot be neglected, at design an electrode and ballast of amalgam lamps with operating discharge current frequency of tens of kHz.

  14. Determination of the cathode and anode voltage drops in high power low-pressure amalgam lamps

    International Nuclear Information System (INIS)

    Vasilyak, L. M.; Vasiliev, A. I.; Kostyuchenko, S. V.; Sokolov, D. V.; Startsev, A. Yu.; Kudryavtsev, N. N.

    2011-01-01

    For the first time, cathode and anode drops of powerful low-pressure amalgam lamps were measured. The lamp discharge current is 3.2 A, discharge current frequency is 43 kHz, linear electric power is 2.4 W/cm. The method of determination of a cathode drop is based on the change of a lamp operating voltage at variation of the electrode filament current at constant discharge current. The total (cathode plus anode) drop of voltage was measured by other, independent ways. The maximum cathode fall is 10.8 V; the anode fall corresponding to the maximal cathode fall is 2.4 V. It is shown that in powerful low pressure amalgam lamps the anode fall makes a considerable contribution (in certain cases, the basic one) to heating of electrodes. Therefore, the anode fall cannot be neglected, at design an electrode and ballast of amalgam lamps with operating discharge current frequency of tens of kHz.

  15. 30 CFR 57.17010 - Electric lamps.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Electric lamps. 57.17010 Section 57.17010 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE....17010 Electric lamps. Individual electric lamps shall be carried for illumination by all persons...

  16. Self-enhanced plasma discharge effect in the deposition of diamond-like carbon films on the inner surface of slender tube

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Yi [Department of 702, Beihang University, Beijing (China); Li, Liuhe, E-mail: liliuhe@buaa.edu.cn [Department of 702, Beihang University, Beijing (China); Luo, Sida [Department of 702, Beihang University, Beijing (China); International Research Institute for Multidisciplinary Science, Beihang University, Beijing (China); Lu, Qiuyuan [Dong Feng Commercial Vehicle Technical Center, Dong Feng Commercial Vehicle Co., LTD, Wuhan (China); Gu, Jiabin; Lei, Ning [Department of 702, Beihang University, Beijing (China); Huo, Chunqin [Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education, Shenzhen University, Guangdong (China)

    2017-01-30

    Highlights: • Effect of inner surface materials of tubes on plasma discharge is examined. • Electron mean free path is used to analyze the films deposition. • Secondary electrons emitted from inner surface of tube enhance plasma discharge. - Abstract: Enhanced glow discharge plasma immersion ion implantation and deposition (EGD-PIII&D) have been proved to be highly effective for depositing diamond-like carbon (DLC) films on the inner surface of the slender quartz tube with a deposition rate of 1.3 μm/min. Such a high-efficiency DLC films deposition was explained previously as the short electrons mean free path to cause large collision frequency between electrons and neutral particles. However, in this paper, we found that the inner surface material of the tube itself play a vital role on the films deposition. To disclose the mechanism of this phenomenon, the effect of different inner surface materials on plasma discharge was experimentally and theoretically investigated. Then a self-enhancing plasma discharge is discovered. It is found that secondary electrons emitted from the inner surface material, whatever it is the tube inner surface or deposited DLC films, can dramatically enhance the plasma discharge to improve the DLC films deposition rate.

  17. Frequency-dependent transition from homogeneous to constricted shape in surface dielectric barrier discharge and its impact on biological target

    Science.gov (United States)

    Lazukin, A. V.; Serdukov, Y. A.; Pinchuk, M. E.; Stepanova, O. M.; Krivov, S. A.; Grabelnykh, O. I.

    2018-01-01

    The results of an experimental research of influence the surface dielectric discharge products excited by alternating sinusoidal voltage with RMS of 3.5 kV across the barrier of aluminum nitride with frequency of 50 Hz–100 kHz on a germination of soft winter wheat (Triticum aestivum L.) are presented. The stimulation effect on seedling morphological characteristics (sprout length and total length of roots) was observed but its reproducibility with combining the same processing conditions and subsequent germination is insignificant.

  18. Defects detecting method of lamp cap of single soldering lug

    Science.gov (United States)

    Cai, Jihe; Lv, Jidong

    2017-07-01

    In order to resolve the problems of low efficiency and large separating difference in fault detection of lamp holders with single soldering lug, an image-detection-based defect detection method is presented in this paper. The selected image is first preprocessed, where the possible area of soldering lug is cut in this preprocessing to narrow the scope for subsequent partition with the consideration that the smooth surface of metal at lamp holder and black insulation glass may reflect the light. Then, the soldering lug is extracted by a series of processing including clustering partition. Based on this, the defects are detected by regional marking, area comparison, circularity and coordinate deviation. The experiment results show that the designed method is simple and practical to detect main quality defects of lamp holder with single soldering lug correctly and efficiently.

  19. Comparison of modelling and experimental results of anode surface melting by femtosecond laser-stimulated electrical discharges in small gaps

    International Nuclear Information System (INIS)

    Chen Jian; He Lingna; Farson, Dave F; Rokhlin, Stanislav I

    2011-01-01

    Experiments and particle-in-cell simulations of femtosecond laser-stimulated electrical discharges in submicrometre gaps between scanning tunnelling microscope tip cathodes and gold film anodes are described. In experiments at applied potentials of 35 V and less, discharges were detected either as self-terminating low-current pulses with durations less than 10 ns and magnitudes less than 200 mA or as higher-current, longer-duration current waveforms. The probability of occurrence of low-current pulses increased as applied potential was decreased, being certain at low potentials of 20-25 V. Low-current pulse waveforms and surface melting of gold anodes predicted by the simulations were compared with experiments. Laser stimulation was modelled by introducing partially ionized electrode materials into the simulation domain at a controlled rate. Simulation results showed that the duration of low-current pulses was influenced by the time over which material was added to the gap region, establishing the importance of electrode vaporization on discharge duration. Subsequently, partially ionized electrode materials were preloaded into the gap in controlled amounts in subsequent simulations. Peak currents predicted by these simulations were nearly equal to the low-current pulse measurements but simulated pulse durations were shorter than experiments. Thus, the time axis of simulation current profiles was normalized for equality of charge transfer with experiments. Anode temperatures and melt diameters calculated from normalized simulated heat input profiles were well matched to experimental measurements.

  20. Electron density in surface barrier discharge emerging at argon/water interface: quantification for streamers and leaders

    Science.gov (United States)

    Cvetanović, Nikola; Galmiz, Oleksandr; Synek, Petr; Zemánek, Miroslav; Brablec, Antonín; Hoder, Tomáš

    2018-02-01

    Optical emission spectroscopy, fast intensified CCD imaging and electrical measurements were applied to investigate the basic plasma parameters of surface barrier discharge emerging from a conductive water electrode. The discharge was generated at the triple-line interface of atmospheric pressure argon gas and conductive water solution at the fused silica dielectrics using a sinusoidal high-voltage waveform. The spectroscopic methods of atomic line broadening and molecular spectroscopy were used to determine the electron densities and the gas temperature in the active plasma. These parameters were obtained for both applied voltage polarities and resolved spatially. Two different spectral signatures were identified in the spatially resolved spectra resulting in electron densities differing by two orders of magnitude. It is shown that two discharge mechanisms take a place: the streamer and the leader one, with electron densities of 1014 and 1016 cm‑3, respectively. This spectroscopic evidence is supported by the combined diagnostics of electrical current measurements and phase-resolved intensified CCD camera imaging.

  1. Response surface method optimization of V-shaped fin assisted latent heat thermal energy storage system during discharging process

    Directory of Open Access Journals (Sweden)

    Sina Lohrasbi

    2016-09-01

    Full Text Available Latent Heat Thermal Energy Storage Systems (LHTESS containing Phase Change Material (PCM are used to establish balance between energy supply and demand. PCMs have high latent heat but low thermal conductivity, which affects their heat transfer performance. In this paper, a novel fin array has been optimized by multi-objective Response Surface Method (RSM based on discharging process of PCM, and then this fin configuration is applied on LHTESS, and comparison between full discharging time by applying this fin array and LHTESS with other fin structures has been carried out. The employed numerical method in this paper is Standard Galerkin Finite Element Method. Adaptive grid refinement is used to solve the equations. Since the enhancement technique, which has been employed in the present study reduces the employed PCM mass, maximum energy storage capacity variations have been considered. Therefore phase change expedition and maximum energy storage capacity have been considered as the objectives of optimization and the importance of second objective is indicated which is proposed as the novelty here. Results indicate that considering maximum energy storage capacity as the objective of optimization procedure leads to efficient shape design of LHTESS. Also employing optimized V-shaped fin in LHTESS, expedites discharging process considerably in comparison with the LHTESS without fin.

  2. Importance of including small-scale tile drain discharge in the calibration of a coupled groundwater-surface water catchment model

    DEFF Research Database (Denmark)

    Hansen, Anne Lausten; Refsgaard, Jens Christian; Christensen, Britt Stenhøj Baun

    2013-01-01

    the catchment. In this study, a coupled groundwater-surface water model based on the MIKE SHE code was developed for the 4.7 km2 Lillebæk catchment in Denmark, where tile drain flow is a major contributor to the stream discharge. The catchment model was calibrated in several steps by incrementally including...... the observation data into the calibration to see the effect on model performance of including diverse data types, especially tile drain discharge. For the Lillebæk catchment, measurements of hydraulic head, daily stream discharge, and daily tile drain discharge from five small (1–4 ha) drainage areas exist....... The results showed that including tile drain data in the calibration of the catchment model improved its general performance for hydraulic heads and stream discharges. However, the model failed to correctly describe the local-scale dynamics of the tile drain discharges, and, furthermore, including the drain...

  3. Surface modification of thermoplastic poly(vinyl alcohol)/saponite nanocomposites via surface-initiated atom transfer radical polymerization enhanced by air dielectric discharges barrier plasma treatment

    International Nuclear Information System (INIS)

    Zhen Weijun; Lu Canhui

    2012-01-01

    To improve the water resistance of thermoplastic poly(vinyl alcohol)/saponite nanocomposites (TPVA), a simple two-step method was developed for the covalent immobilization of atom transfer radical polymerization (ATRP) initiators on the TPVA surfaces enhanced by air dielectric barrier discharges (DBD) plasma treatment, and hydrophobic poly(methyl methacrylate) (PMMA) brushes were then grafted onto the surface of TPVA via surface-initiated atom transfer radical polymerization (SI-ATRP). The chemical composition, morphology and hydrophobicity of the modified TPVA surfaces were characterized by X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM), respectively. The water resistance of the surface-functionalized PMMA was evaluated by the contact angle and water adsorption method. It was shown that air DBD plasma treatment activated the TPVA surface and accelerated the immobilization of ATRP initiator on the TPVA surface. Compared with TPVA control, TPVA modified by SI-ATRP can be grafted well-defined and covalently tethered network PMMA brushes onto the surface and the hydrophobicity of TPVA were significantly enhanced.

  4. Microstructure analysis of the martensitic stainless steel surface fine-cut by the wire electrode discharge machining (WEDM)

    International Nuclear Information System (INIS)

    Huang, C.A.; Hsu, F.Y.; Yao, S.J.

    2004-01-01

    In this research, quenched and tempered martensitic stainless steels, AISI 440A, were subjected to multi-cutting passes by wire electrical discharge machining (WEDM). The WEDM is widely applied to final surface shaping of harden steel. The steel was roughly machined at first cutting pass, semi-finished by two cutting passes, and then finished by one cutting passes, all machined by WEDM. The negatively polarized wire electrode (NPWE) was used for all of these four cutting passes. Some finished specimens were further extra-finished by using the positively polarized wire electrode (PPWE). Microstructures of the finished surfaces using NPWE as well as PPWE were studied with scanning and transmission electron microscopes (SEM and TEM). Chemical composition was analyzed by an energy-dispersive X-ray spectrometer (EDX) integrated in SEM or TEM. The study of the finished surfaces with NPWE shows that a heat-affected zone (HAZ) of about 1.5 μm thick was developed. The HAZ is composed of very fine equiaxed martensitic grains of about 200 nm with concentrated dislocations, but the temper-induced carbides were not found. A few spherical deposits of wire electrode material were also registered. Oxides with ca. 10 nm in diameter were detected around the deposits. The spherical deposits were characterized as 'bull eye' in TEM according to their appearance. For the surface finished with PPWE, no obvious HAZ was detected, but a very thin (<50 nm) and uniform amorphous layer composed of wire electrode and workpiece material was found. The structural difference between the two finished surfaces was explained based on the theory of electrical discharging and metallurgical physics

  5. A Review of Additive Mixed-Electric Discharge Machining: Current Status and Future Perspectives for Surface Modification of Biomedical Implants

    Directory of Open Access Journals (Sweden)

    Abdul’Azeez Abdu Aliyu

    2017-01-01

    Full Text Available Surface treatment remained a key solution to numerous problems of synthetic hard tissues. The basic methods of implant surface modification include various physical and chemical deposition techniques. However, most of these techniques have several drawbacks such as excessive cost and surface cracks and require very high sintering temperature. Additive mixed-electric discharge machining (AM-EDM is an emerging technology which simultaneously acts as a machining and surface modification technique. Aside from the mere molds, dies, and tool fabrication, AM-EDM is materializing to finishing of automobiles and aerospace, nuclear, and biomedical components, through the concept of material migrations. The mechanism of material transfer by AM-EDM resembles electrophoretic deposition, whereby the additives in the AM-EDM dielectric fluids are melted and migrate to the machined surface, forming a mirror-like finishing characterized by extremely hard, nanostructured, and nanoporous layers. These layers promote the bone in-growth and strengthen the cell adhesion. Implant shaping and surface treatment through AM-EDM are becoming a key research focus in recent years. This paper reports and summarizes the current advancement of AM-EDM as a potential tool for orthopedic and dental implant fabrication. Towards the end of this paper, the current challenges and future research trends are highlighted.

  6. Materials for incandescent and fluorescent lamps

    DEFF Research Database (Denmark)

    Thorsen, Knud Aage

    1996-01-01

    The article gives an overview of the materials systems used for incandescent lamps as well as a brief introduction to the systems used for fluorescent lamps. The materials used for incandescent lamps are doped tungsten used for the filaments, metals and alloys used for terminal and support posts......, lead wires and internal reflectors and screens as well as glasses for the envelope. The physics of bulbs and changes in bulbs during use are elucidated. The cost and energy savings and environmental benefits by replacement of incandescent lamps by fluorescent lamps are presented....

  7. A prototype of radar-drone system for measuring the surface flow velocity at river sites and discharge estimation

    Science.gov (United States)

    Moramarco, Tommaso; Alimenti, Federico; Zucco, Graziano; Barbetta, Silvia; Tarpanelli, Angelica; Brocca, Luca; Mezzanotte, Paolo; Rosselli, Luca; Orecchini, Giulia; Virili, Marco; Valigi, Paolo; Ciarfuglia, Thomas; Pagnottelli, Stefano

    2015-04-01

    Discharge estimation at a river site depends on local hydraulic conditions identified by recording water levels. In fact, stage monitoring is straightforward and relatively inexpensive compared with the cost necessary to carry out flow velocity measurements which are, however, limited to low flows and constrained by the accessibility of the site. In this context the mean flow velocity is hard to estimate for high flow, affecting de-facto the reliability of discharge assessment for extreme events. On the other hand, the surface flow velocity can be easily monitored by using radar sensors allowing to achieve a good estimate of discharge by exploiting the entropy theory applied to rivers hydraulic (Chiu,1987). Recently, a growing interest towards the use of Unmanned Aerial Vehicle (UVA), henceforth drone, for topographic applications is observed and considering their capability drones may be of a considerable interest for the hydrological monitoring and in particular for streamflow measurements. With this aim, for the first time, a miniaturized Doppler radar sensor, operating at 24 GHz, will be mounted on a drone to measure the surface flow velocity in rivers. The sensor is constituted by a single-board circuit (i.e. is a fully planar circuits - no waveguides) with the antenna on one side and the front-end electronic on the other side (Alimenti et al., 2007). The antenna has a half-power beam width of less than 10 degrees in the elevation plane and a gain of 13 dBi. The radar is equipped with a monolithic oscillator and transmits a power of about 4 mW at 24 GHz. The sensor is mounted with an inclination of 45 degrees with respect to the drone flying plane and such an angle is considered in recovering the surface speed of the water. The drone is a quadricopter that has more than 30 min, flying time before recharging the battery. Furthermore its flying plan can be scheduled with a suitable software and is executed thanks to the on-board sensors (GPS, accelerometers

  8. Lowering the ignition voltage by the dual microhollow cathode configuration for multichannel flat panel lamp

    International Nuclear Information System (INIS)

    Lee, Tae Il; Park, Ki Wan; Lee, Sung Won; Baik, Hong Koo

    2006-01-01

    We have developed a dual microhollow cathode configuration, employing one power supply circuit with a resistor that is suitable for lamp starting without additional power supplier. We also investigated their electrical characteristics and photo images, varying the applied voltage. The electrical and optical measurements showed that the discharge passed through four distinct stages: no discharges, the first microhollow cathode discharges, the both of the first and second microhollow cathode discharges, and finally the main discharge. As a result, the V s and E s /p of a dual microhollow configuration were lower by a factor of about 2 than those of a diode at 40 Torr. We have also observed that the parallel operation can be possible with a single resistor in nine channels flat panel lamp

  9. Harmonics Monitoring Survey on LED Lamps

    Directory of Open Access Journals (Sweden)

    Abdelrahman Ahmed Akila

    2017-03-01

    Full Text Available Light Emitting Diode (LED lamps are being increasingly used in many applications. These LED lamps operate using a driver, which is a switching device. Hence, LED lamps will be a source of harmonics in the power system. These harmonics if not well treated, may cause severe performance and operational problems. In this paper, harmonics (amplitude and phase angles generated by both LED lamps and conventional fluorescent lamps will be studied practically. Then they will be analyzed and evaluated. Compared to each other harmonics generated by both LED and conventional florescent lamps, self mitigation may occur based on the phase angle of these harmonics. All data will be measured using power analyzer and will be done on a sample of actual lamps.

  10. Polytetrafluoroethylene surface modification by filamentary and homogeneous dielectric barrier discharges in air

    International Nuclear Information System (INIS)

    Fang Zhi; Hao Lili; Yang Hao; Xie Xiangqian; Qiu Yuchang; Edmund, Kuffel

    2009-01-01

    In this paper, polytetrafluoroethylene (PTFE) films are modified using non-equilibrium plasma generated by homogeneous DBD in air at medium pressure, and the results are compared to those treated by using filamentary DBD in air at atmospheric pressure. The surface properties of PTFE films before and after the treatments are studied using contact angle and surface energy measurement, X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). It is found that the plasma treatments modify the PTFE surface in both morphology and composition. The PTFE films modified in both treatments show a remarkable decrease in water contact and a remarkable increase in surface energy. XPS analysis reveals that oxygen-containing polar groups are introduced onto the PTFE surface, and SEM analysis shows that the surfaces of the films are etched after both the treatments. It is found that homogeneous DBD is more effective in PTFE surface modification than filamentary DBD as it can make the contact angle decline to a lower level by introducing more oxygen-containing groups, and the possible reason for this effect is discussed.

  11. Surface hardening of optic materials by deposition of diamond like carbon coatings from separated plasma of arc discharge

    Science.gov (United States)

    Osipkov, A. S.; Bashkov, V. M.; Belyaeva, A. O.; Stepanov, R.; Mironov, Y. M.; Galinovsky, A. L.

    2015-02-01

    This article considers the issue of strengthening of optic materials used in the IR spectrum by deposition of diamond like carbon coatings from separated plasma arc discharge. The report shows results of tests of bare and strengthened optical materials such as BaF2, MgF2, Si, Ge, including the testing of their strength and spectral characteristics. Results for the determination of optical constants for the DLC coatings deposited on substrates of Ge and Si, by using separated plasma, are also presented. Investigations showed that surface hardening of optical materials operable in the IR range, by the deposition of diamond like carbon coating onto their surface, according to this technology, considerably improves operational properties and preserves or improves their optic properties.

  12. Surface modification of polyvinyl alcohol/malonic acid nanofibers by gaseous dielectric barrier discharge plasma for glucose oxidase immobilization

    Energy Technology Data Exchange (ETDEWEB)

    Afshari, Esmail, E-mail: e.afshari@mail.sbu.ac.ir [Laser and Plasma Research Institute, Shahid Beheshti University, Evin, 1983963113 Tehran (Iran, Islamic Republic of); Mazinani, Saeedeh [Amirkabir Nanotechnology Research Institute (ANTRI), Amirkabir University of Technology, 15875-4413, Tehran (Iran, Islamic Republic of); Ranaei-Siadat, Seyed-Omid [Protein Research Center, Shahid Beheshti University, Evin, 1983963113 Tehran (Iran, Islamic Republic of); Ghomi, Hamid [Laser and Plasma Research Institute, Shahid Beheshti University, Evin, 1983963113 Tehran (Iran, Islamic Republic of)

    2016-11-01

    Highlights: • We fabricated polyvinyl alcohol/malonic acid nanofibers using electrospinning. • The surface nanofibers were modified by gaseous (air, nitrogen, CO{sub 2} and argon) dielectric barrier discharge. • Among them, air plasma had the most significant effect on glucose oxidase immobilization. • Chemical analysis showed that after modification of nanofibers by air plasma, the carboxyl group increased. • After air plasma treatment, reusability and storage stability of glucose oxidase immobilized on nanofibers improved. - Abstract: Polymeric nanofiber prepares a suitable situation for enzyme immobilization for variety of applications. In this research, we have fabricated polyvinyl alcohol (PVA)/malonic acid nanofibers using electrospinning. After fabrication of nanofibers, the effect of air, nitrogen, CO{sub 2}, and argon DBD (dielectric barrier discharge) plasmas on PVA/malonic acid nanofibers were analysed. Among them, air plasma had the most significant effect on glucose oxidase (GOx) immobilization. Attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectrum analysis and X-ray photoelectron spectroscopy (XPS) results revealed that in case of air plasma modified nanofibers, the carboxyl groups on the surface are increased. The scanning electron microscopy (SEM) images showed that, after GOx immobilization, the modified nanofibers with plasma has retained its nanofiber structure. Finally, we analysed reusability and storage stability of GOx immobilized on plasma modified and unmodified nanofibers. The results were more satisfactory for modified nanofibers with respect to unmodified ones.

  13. Near-surface Heating of Young Rift Sediment Causes Mass Production and Discharge of Reactive Dissolved Organic Matter

    Science.gov (United States)

    Lin, Yu-Shih; Koch, Boris P.; Feseker, Tomas; Ziervogel, Kai; Goldhammer, Tobias; Schmidt, Frauke; Witt, Matthias; Kellermann, Matthias Y.; Zabel, Matthias; Teske, Andreas; Hinrichs, Kai-Uwe

    2017-03-01

    Ocean margin sediments have been considered as important sources of dissolved organic carbon (DOC) to the deep ocean, yet the contribution from advective settings has just started to be acknowledged. Here we present evidence showing that near-surface heating of sediment in the Guaymas Basin, a young extensional depression, causes mass production and discharge of reactive dissolved organic matter (DOM). In the sediment heated up to ~100 °C, we found unexpectedly low DOC concentrations in the pore waters, reflecting the combined effect of thermal desorption and advective fluid flow. Heating experiments suggested DOC production to be a rapid, abiotic process with the DOC concentration increasing exponentially with temperature. The high proportions of total hydrolyzable amino acids and presence of chemical species affiliated with activated hydrocarbons, carbohydrates and peptides indicate high reactivity of the DOM. Model simulation suggests that at the local scale, near-surface heating of sediment creates short and massive DOC discharge events that elevate the bottom-water DOC concentration. Because of the heterogeneous distribution of high heat flow areas, the expulsion of reactive DOM is spotty at any given time. We conclude that hydrothermal heating of young rift sediments alter deep-ocean budgets of bioavailable DOM, creating organic-rich habitats for benthic life.

  14. Atmospheric pressure argon surface discharges propagated in long tubes: physical characterization and application to bio-decontamination

    International Nuclear Information System (INIS)

    Kovalova, Zuzana; Leroy, Magali; Jacobs, Carolyn; Kirkpatrick, Michael J; Odic, Emmanuel; Machala, Zdenko; Lopes, Filipa; Laux, Christophe O; DuBow, Michael S

    2015-01-01

    Pulsed corona discharges propagated in argon (or in argon with added water vapor) at atmospheric pressure on the interior surface of a 49 cm long quartz tube were investigated for the application of surface bio-decontamination. H 2 O molecule dissociation in the argon plasma generated reactive species (i.e. OH in ground and excited states) and UV emission, which both directly affected bacterial cells. In order to facilitate the evaluation of the contribution of UV radiation, a DNA damage repair defective bacterial strain, Escherichia coli DH-1, was used. Discharge characteristics, including propagation velocity and plasma temperature, were measured. Up to ∼5.5 and ∼5 log 10 reductions were observed for E. coli DH-1 bacteria (from 10 6 initial load) exposed 2 cm and 44 cm away from the charged electrode, respectively, for a 20 min plasma treatment. The factors contributing to the observed bactericidal effect include desiccation, reactive oxygen species (OH) plus H 2 O 2 accumulation in the liquid phase, and UV-B (and possibly VUV) emission in dry argon. The steady state temperature measured on the quartz tube wall did not exceeded 29 °C; the contribution of heating, along with that of H 2 O 2 accumulation, was estimated to be low. The effect of UV-B emission alone or in combination with the other stress factors of the plasma process was examined for different operating conditions. (paper)

  15. Near-surface Heating of Young Rift Sediment Causes Mass Production and Discharge of Reactive Dissolved Organic Matter.

    Science.gov (United States)

    Lin, Yu-Shih; Koch, Boris P; Feseker, Tomas; Ziervogel, Kai; Goldhammer, Tobias; Schmidt, Frauke; Witt, Matthias; Kellermann, Matthias Y; Zabel, Matthias; Teske, Andreas; Hinrichs, Kai-Uwe

    2017-03-22

    Ocean margin sediments have been considered as important sources of dissolved organic carbon (DOC) to the deep ocean, yet the contribution from advective settings has just started to be acknowledged. Here we present evidence showing that near-surface heating of sediment in the Guaymas Basin, a young extensional depression, causes mass production and discharge of reactive dissolved organic matter (DOM). In the sediment heated up to ~100 °C, we found unexpectedly low DOC concentrations in the pore waters, reflecting the combined effect of thermal desorption and advective fluid flow. Heating experiments suggested DOC production to be a rapid, abiotic process with the DOC concentration increasing exponentially with temperature. The high proportions of total hydrolyzable amino acids and presence of chemical species affiliated with activated hydrocarbons, carbohydrates and peptides indicate high reactivity of the DOM. Model simulation suggests that at the local scale, near-surface heating of sediment creates short and massive DOC discharge events that elevate the bottom-water DOC concentration. Because of the heterogeneous distribution of high heat flow areas, the expulsion of reactive DOM is spotty at any given time. We conclude that hydrothermal heating of young rift sediments alter deep-ocean budgets of bioavailable DOM, creating organic-rich habitats for benthic life.

  16. Tailored Voltage Waveforms in an SF6 /O2 discharge: slope asymmetry and its effect on surface nanotexturing of silicon

    Science.gov (United States)

    Fischer, G.; Drahi, E.; Poulain, G.; Bruneau, B.; Johnson, E. V.

    2016-09-01

    The nanotexturing of the surface of a crystalline silicon (c-Si) wafer for improved photovoltaic performance can be achieved through the use of a SF6 /O2 capacitively coupled reactive ion etching plasma. In this study, we attempt to modify the texturing conditions by taking advantage of slope asymmetries of Tailored Voltage Waveform (TVW) excitation. We show that TVW shapes resembling ``sawtooths'', presenting a large slope asymmetry, induce high ionization asymmetries in the discharge, and that the dominance of this effect strongly depends on both gas mixture and pressure. These asymmetries have been previously observed in other electronegative gas and are due to differing plasma sheath dynamics at powered and grounded electrode in a discharge operating in drift-ambipolar mode. The texturing of c-Si in SF6 /O2 occurs through competing mechanisms, including etching by fluorine radicals and in-situ deposition of micro-masking species. The relative fluxes of etching and passivating species are expected to be strongly varied due to the plasma asymmetry. Morphological and optical characterization of textured c-Si surfaces will give more insight into both the plasma properties and the mechanisms involved in dry nanotexturing. This project has been supported by the French Government in the frame of the program of investment for the future (Programme d'Investissement d'Avenir - ANR-IEED-002-01).

  17. PREDICTION OF SURFACE ROUGHNESS OF TI-6AL-4V IN ELECTRICAL DISCHARGE MACHINING: A REGRESSION MODEL

    Directory of Open Access Journals (Sweden)

    M.A. Maleque

    2011-12-01

    Full Text Available This paper develops a single order mathematical model for correlating various electrical discharge machining (EDM parameters and performance characteristics by utilizing relevant experimental data obtained through experimentation. In addition to the effect of peak ampere, the effect of pulse on time and pulse off time on surface roughness has also been investigated. Experiments have been conducted on titanium alloy Ti-6Al-4V with a copper electrode retaining negative polarity as per the Design of Experiments. Response surface methodology techniques are utilized to develop the mathematical model as well as to optimize the EDM parameters. An analysis of variance has been performed for the validity test of fit and adequacy of the proposed models. It can be seen that increasing pulse on time causes a fine surface until a certain value, beyond which the surface finish deteriorates. The excellent surface finish is investigated in this study for the case of pulse on time below 80 µs. This result acts as a guide for selecting the required process outputs and most economic industrial machining conditions for optimizing the input factors.

  18. Investigation of working pressure on the surface roughness controlling technology of glow discharge polymer films based on the diagnosed plasma

    Science.gov (United States)

    Zhang, Ling; Chen, Guo; He, Zhibing; Ai, Xing; Huang, Jinglin; Liu, Lei; Tang, Yongjian; He, Xiaoshan

    2017-07-01

    The effects of working pressure on the component, surface morphology, surface roughness, and deposition rate of glow discharge polymer (GDP) films by a trans-2-butene/hydrogen gas mixture were investigated based on plasma characteristics diagnosis. The composition and ion energy distributions of a multi-carbon (C4H8/H2) plasma mixture at different working pressures were diagnosed by an energy-resolved mass spectrometer (MS) during the GDP film deposition process. The Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscope (SEM) and white-light interferometer (WLI) results were obtained to investigate the structure, morphology and roughness characterization of the deposited films, respectively. It was found that the degree of ionization of the C4H8/H2 plasma reduces with an increase in the working pressure. At a low working pressure, the C-H fragments exhibited small-mass and high ion energy in plasma. In this case, the film had a low CH3/CH2 ratio, and displayed a smooth surface without any holes, cracks or asperities. While the working pressure increased to 15 Pa, the largest number of large-mass fragments led to the deposition rate reaching a maximum of 2.11 μm h-1, and to hole defects on the film surface. However, continuing to increase the working pressure, the film surface became smooth again, and the interface between clusters became inconspicuous without etching pits.

  19. Fast enhancement on hydrophobicity of poplar wood surface using low-pressure dielectric barrier discharges (DBD) plasma

    Science.gov (United States)

    Chen, Weimin; Zhou, Xiaoyan; Zhang, Xiaotao; Bian, Jie; Shi, Shukai; Nguyen, Thiphuong; Chen, Minzhi; Wan, Jinglin

    2017-06-01

    The hydrophilicity of woody products leads to deformation and cracks, which greatly limits its applications. Low-pressure dielectric barrier discharge (DBD) plasma using hexamethyldisiloxane was applied in poplar wood surface to enhance the hydrophobicity. The chemical properties, micro-morphology, and contact angles of poplar wood surface before and after plasma treatment were investigated by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), x-ray photoelectron spectroscopy (XPS), scanning electron microscope and energy dispersive analysis of X-ray (SEM-EDX), atomic force microscopy (AFM), and optical contact angle measurement (OCA). Moreover, tinfoil film was used as the base to reveal the enhancement mechanism. The results showed that hexamethyldisiloxane monomer is first broken into several fragments with active sites and hydrophobic chemical groups. Meanwhile, plasma treatment results in the formation of free radicals and active sites in the poplar wood surface. Then, the fragments are reacted with free radicals and incorporated into the active sites to form a network structure based on the linkages of Si-O-Si and Sisbnd Osbnd C. Plasma treatment also leads to the formation of acicular nano-structure in poplar wood surface. These facts synergistically enhance the hydrophobicity of poplar wood surface, demonstrating the dramatically increase in the equilibrium contact angle by 330%.

  20. Surface oxide net charge of a titanium alloy: comparison between effects of treatment with heat or radiofrequency plasma glow discharge.

    Science.gov (United States)

    MacDonald, Daniel E; Rapuano, Bruce E; Schniepp, Hannes C

    2011-01-01

    In the current study, we have compared the effects of heat and radiofrequency plasma glow discharge (RFGD) treatment of a Ti6Al4V alloy on the physico-chemical properties of the alloy's surface oxide. Titanium alloy (Ti6Al4V) disks were passivated alone, heated to 600 °C, or RFGD plasma treated in pure oxygen. RFGD treatment did not alter the roughness, topography, elemental composition or thickness of the alloy's surface oxide layer. In contrast, heat treatment altered oxide topography by creating a pattern of oxide elevations approximately 50-100 nm in diameter. These nanostructures exhibited a three-fold increase in roughness compared to untreated surfaces when RMS roughness was calculated after applying a spatial high-pass filter with a 200 nm-cutoff wavelength. Heat treatment also produced a surface enrichment in aluminum and vanadium oxides. Both RFGD and heat treatment produced similar increases in oxide wettability. Atomic force microscopy (AFM) measurements of metal surface oxide net charge signified by a long-range force of attraction to or repulsion from a (negatively charged) silicon nitride AFM probe were also obtained for all three experimental groups. Force measurements showed that the RFGD-treated Ti6Al4V samples demonstrated a higher net positive surface charge at pH values below 6 and a higher net negative surface charge at physiological pH (pH values between 7 and 8) compared to control and heat-treated samples. These findings suggest that RFGD treatment of metallic implant materials can be used to study the role of negatively charged surface oxide functional groups in protein bioactivity, osteogenic cell behavior and osseointegration independently of oxide topography. Published by Elsevier B.V.

  1. A self-consistent LTE model of a microwave-driven, high-pressure sulfur lamp

    Energy Technology Data Exchange (ETDEWEB)

    Johnston, C.W.; Mullen, J.J.A.M. van der [Department of Applied Physics, Eindhoven University of Technology (Netherlands)]. E-mails: C.W.Johnston@tue.nl; J.J.A.M.v.d.Mullen@tue.nl; Heijden, H.W.P. van der; Janssen, G.M.; Dijk, J. van [Department of Applied Physics, Eindhoven University of Technology (Netherlands)

    2002-02-21

    A one-dimensional LTE model of a microwave-driven sulfur lamp is presented to aid our understanding of the discharge. The energy balance of the lamp is determined by Ohmic input on one hand and transport due to conductive heat transfer and molecular radiation on the other. We discuss the origin of operational trends in the spectrum, present the model and discuss how the material properties of the plasma are determined. Not only are temperature profiles and electric field strengths simulated but also the spectrum of the lamp from 300 to 900 nm under various conditions of input power and lamp filling pressure. We show that simulated spectra demonstrate observed trends and that radiated power increases linearly with input power as is also found from experiment. (author)

  2. On the Concept of Electrode to Discharge Phenomena in Surface Roughness With Reference Strongly Electronegative Gases

    DEFF Research Database (Denmark)

    McAllister, Iain Wilson

    1986-01-01

    The use of geometrically well-defined protrusions in studies es of the effects of electrode surface roughness upon the insulation strength of strongly electronegative gases is discussed. It is argued that, with respect to the roughness associated with production processes, the dimensions of artif......The use of geometrically well-defined protrusions in studies es of the effects of electrode surface roughness upon the insulation strength of strongly electronegative gases is discussed. It is argued that, with respect to the roughness associated with production processes, the dimensions...

  3. The Plasma Discharge System For Effective Sterilization Of Water And Solid Surfaces

    International Nuclear Information System (INIS)

    Senturk, K.

    2010-01-01

    The different areas such as medicine, surgery, food production need efficient sterilization system since they are directly related to human health. In this work a new plasma system is described in order to present its effectiveness in sterilization. This is a different method from conventional methods such as: chemicals and heat addition, UV irradiation etc. The developed plasma system produces cold plasma working under atmospheric pressure. To generate the plasma both AC and DC high voltage power supplies were used. The developed system is cheap and very effective for sterilization. The light emission for both AC and DC coronas for the plasmas were investigated to understand the nature of generated plasma ionization. Different parameters like temperature, voltage, application time were changed during the plasma application and the optimization for killing the micro-organisms were investigated. To understand the biological effect of plasma on the organisms comparisons were done by using the scanning electron microscope and absorption spectrometer. The plasma was applied on the bacteria like Escherichia coli, Bacillus subtilis, Streptococcus mutans , the yeasts such as Candida albicans, and green algae. The efficiency, the non toxic nature, the affordable price make this plasma discharge method a very efficient one for sterilization.

  4. Functionalized luminescent nanocrystals on patterned surfaces obtained by radio frequency glow discharges

    Science.gov (United States)

    Sardella, E.; Liuzzi, F.; Comparelli, R.; Depalo, N.; Striccoli, M.; Agostiano, A.; Favia, P.; Curri, M. L.

    2013-04-01

    In this work a genuine combination of a bottom-up approach, which is based on synthesis and functionalization of emitting nanocrystals (NCs), with a top-down strategy, which relies on a flexible and versatile cold plasma process, is shown. Luminescent semiconducting colloidal NCs consisting of a CdSe core coated with a ZnS shell (CdSe@ZnS) are directly assembled onto micro-patterned substrates previously functionalized by means of glow discharges performed through physical masks. The NC assembly is driven by electrostatic interactions that led to their successful organization into spatially resolved domains. Two distinct protocols are tested, the former using a plasma deposition process combined with an electrostatic layer-by-layer procedure, the latter based on a two-step plasma deposition/treatment process. The procedures are thoroughly monitored with fluorescence microscopy, atomic force microscopy, x-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, transmission electron microscopy and scanning electron microscopy. The two-step plasma protocol is demonstrated to be more efficient in directing a uniform and specific assembly of luminescent NCs with respect to the hybrid procedure. The presented ‘mix and match’ approach offers great potential for integrating NCs, with their unique size-dependent properties, into microstructures, providing a universal platform for the fabrication of sensors, biochips, displays and switches.

  5. Effect of dielectric barrier discharge treatment on surface nanostructure and wettability of polylactic acid (PLA) nonwoven fabrics

    Science.gov (United States)

    Ren, Yu; Xu, Lin; Wang, Chunxia; Wang, Xiaona; Ding, Zhirong; Chen, Yuyue

    2017-12-01

    Polylactic acid (PLA) nonwoven fabrics are treated with atmospheric dielectric barrier discharge (DBD) plasma to improve surface wettability. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) show that micro- to nano-scale textures appear on the treated PLA surfaces dependent on the treatment time. X-ray photoelectron spectroscopy (XPS) analysis reveals that the DBD plasma treatments result in decreased carbon contents and increased oxygen contents as well as slightly increased nitrogen contents. The water contact angle decreases sharply with the increase of the DBD plasma treatment time. The super hydrophilic PLA surfaces (the water contact angle reached 0°) are obtained when the treatment time is longer than 90 s. Ninety days after the DBD plasma treatment, the XPS analysis shows that Csbnd O/Csbnd N and Cdbnd O/Osbnd Cdbnd O percentages decline for all treatment groups. However, the water contact angle is kept constant at 0° for the groups treated above 90 s, which could be due to the oxidized nano-structured layer on the DBD plasma treated PLA surfaces.

  6. Modification of surface properties of high and low density polyethylene by Ar plasma discharge

    Czech Academy of Sciences Publication Activity Database

    Švorčík, J.; Kolářová, K.; Slepička, P.; Macková, Anna; Novotná, M.; Hnatowicz, Vladimír

    2006-01-01

    Roč. 91, č. 6 (2006), s. 1219-1225 ISSN 0141-3910 R&D Projects: GA MŠk OC 527.100; GA MŠk 1P05OC014 Institutional research plan: CEZ:AV0Z10480505 Keywords : plasma polymer isation * surface modification Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.174, year: 2006

  7. Surface modification and stability of detonation nanodiamonds in microwave gas discharge plasma

    International Nuclear Information System (INIS)

    Stanishevsky, Andrei V.; Walock, Michael J.; Catledge, Shane A.

    2015-01-01

    Graphical abstract: - Highlights: • Single and binary gas plasma modification of nanodiamond powders studied. • Temperature-dependent effect of N 2 and N 2 /H 2 plasma reported for the first time. • Role of H 2 in H 2 /N 2 and H 2 /O 2 plasma modification of nanodiamond discussed. - Abstract: Detonation nanodiamonds (DND), with low hydrogen content, were exposed to microwave plasma generated in pure H 2 , N 2 , and O 2 gases and their mixtures, and investigated using X-ray diffraction (XRD), Fourier Transform Infrared (FTIR), Raman, and X-ray photoelectron spectroscopies. Considerable alteration of the DND surface was observed under the plasma conditions for all used gases, but the diamond structure of the DND particle core was preserved in most cases. The stabilizing effect of H 2 in H 2 /N 2 and H 2 /O 2 binary gas plasmas on the DND structure and the temperature-dependent formation of various CNH x surface groups in N 2 and H 2 /N 2 plasmas were observed and discussed for the first time. DND surface oxidation and etching were the main effects of O 2 plasma, whereas the N 2 plasma led to DND surfaces rich in amide groups below 1073 K and nitrile groups at higher temperatures. Noticeable graphitization of the DND core structure was detected only in N 2 plasma when the substrate temperature was above 1103 K.

  8. Raether–Meek criterion for prediction of electrodeless discharge inception on a dielectric surface in different gases

    Science.gov (United States)

    Chvyreva, A.; Pancheshnyi, S.; Christen, T.; Pemen, A. J. M.

    2018-03-01

    Electrodeless streamer inception on an epoxy surface under AC voltage stress was investigated for different gas compositions and pressures, with a focus on the pressure region below 1 bar. For this purpose, we used a set-up with cylindrical electrodes embedded out-of-axis in a cylindrical epoxy rod. Experiments were performed in N2, SF6, ambient air, Ar and CO2. The discharge inception voltage was measured, from which the critical value K of the ionization integral was reconstructed assuming a non-disturbed Laplacian field distribution. We have validated that for electropositive gases Ar an N2 the generally assumed value of K  =  10 is in good agreement with our measurements. For electronegative gases, however, the experimentally obtained values turned out to be considerably higher. We attribute this discrepancy mainly to the statistical time delay of the first electron; to increase the probability of discharge inception in a critical region, it was necessary to extend the critical area by means of applying an overvoltage to the system.

  9. Plasma treatment of detonation and HPHT nanodiamonds in diffuse coplanar surface barrier discharge in H.sub.2./sub./N.sub.2./sub. flow

    Czech Academy of Sciences Publication Activity Database

    Jirásek, Vít; Čech, J.; Kozak, Halyna; Artemenko, Anna; Černák, M.; Kromka, Alexander

    2016-01-01

    Roč. 213, č. 10 (2016), s. 2680-2686 ISSN 1862-6300 R&D Projects: GA ČR(CZ) GA14-04790S Institutional support: RVO:68378271 Keywords : amination * diamond * diffuse coplanar surface barrier discharge * nanomaterials * surface functionalization Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.775, year: 2016

  10. Influence of Power Modulation on Ozone Production Using an AC Surface Dielectric Barrier Discharge in Oxygen

    Czech Academy of Sciences Publication Activity Database

    Šimek, Milan; Pekárek, S.; Prukner, Václav

    2010-01-01

    Roč. 30, č. 5 (2010), s. 607-617 ISSN 0272-4324 R&D Projects: GA ČR(CZ) GA202/09/0176 Institutional research plan: CEZ:AV0Z20430508 Keywords : Ozone * Surface DBD * Oxygen * Production efficiency Subject RIV: BL - Plasma and Gas Disc harge Physics Impact factor: 1.798, year: 2010 http://www.springerlink.com/content/28539775w5243513/

  11. Surface modification and stability of detonation nanodiamonds in microwave gas discharge plasma

    Energy Technology Data Exchange (ETDEWEB)

    Stanishevsky, Andrei V., E-mail: astan@uab.edu; Walock, Michael J.; Catledge, Shane A.

    2015-12-01

    Graphical abstract: - Highlights: • Single and binary gas plasma modification of nanodiamond powders studied. • Temperature-dependent effect of N{sub 2} and N{sub 2}/H{sub 2} plasma reported for the first time. • Role of H{sub 2} in H{sub 2}/N{sub 2} and H{sub 2}/O{sub 2} plasma modification of nanodiamond discussed. - Abstract: Detonation nanodiamonds (DND), with low hydrogen content, were exposed to microwave plasma generated in pure H{sub 2}, N{sub 2}, and O{sub 2} gases and their mixtures, and investigated using X-ray diffraction (XRD), Fourier Transform Infrared (FTIR), Raman, and X-ray photoelectron spectroscopies. Considerable alteration of the DND surface was observed under the plasma conditions for all used gases, but the diamond structure of the DND particle core was preserved in most cases. The stabilizing effect of H{sub 2} in H{sub 2}/N{sub 2} and H{sub 2}/O{sub 2} binary gas plasmas on the DND structure and the temperature-dependent formation of various CNH{sub x} surface groups in N{sub 2} and H{sub 2}/N{sub 2} plasmas were observed and discussed for the first time. DND surface oxidation and etching were the main effects of O{sub 2} plasma, whereas the N{sub 2} plasma led to DND surfaces rich in amide groups below 1073 K and nitrile groups at higher temperatures. Noticeable graphitization of the DND core structure was detected only in N{sub 2} plasma when the substrate temperature was above 1103 K.

  12. Causes of plasma column contraction in surface-wave-driven discharges in argon at atmospheric pressure

    Science.gov (United States)

    Ridenti, Marco Antonio; de Amorim, Jayr; Dal Pino, Arnaldo; Guerra, Vasco; Petrov, George

    2018-01-01

    In this work we compute the main features of a surface-wave-driven plasma in argon at atmospheric pressure in view of a better understanding of the contraction phenomenon. We include the detailed chemical kinetics dynamics of Ar and solve the mass conservation equations of the relevant neutral excited and charged species. The gas temperature radial profile is calculated by means of the thermal diffusion equation. The electric field radial profile is calculated directly from the numerical solution of the Maxwell equations assuming the surface wave to be propagating in the TM00 mode. The problem is considered to be radially symmetrical, the axial variations are neglected, and the equations are solved in a self-consistent fashion. We probe the model results considering three scenarios: (i) the electron energy distribution function (EEDF) is calculated by means of the Boltzmann equation; (ii) the EEDF is considered to be Maxwellian; (iii) the dissociative recombination is excluded from the chemical kinetics dynamics, but the nonequilibrium EEDF is preserved. From this analysis, the dissociative recombination is shown to be the leading mechanism in the constriction of surface-wave plasmas. The results are compared with mass spectrometry measurements of the radial density profile of the ions Ar+ and Ar2+. An explanation is proposed for the trends seen by Thomson scattering diagnostics that shows a substantial increase of electron temperature towards the plasma borders where the electron density is small.

  13. On electrode erosion in fluorescent lamps during instant start

    Energy Technology Data Exchange (ETDEWEB)

    Hadrath, S.

    2006-09-15

    A fluorescent lamp driven with an 'instant start electronic control gear' starts in a glow mode. In the glow mode, which lasts typically for tens of milliseconds, the cathode fall exceeds hundreds of volts. This causes high energy ion bombardment of the electrode which heats the electrode, and induces a transition from glow to arc mode. In the arc mode the electrode emits thermionically and the cathode fall drops to the 12 - 15 V range. Unfortunately, the high energy ion bombardment during the glow mode leads also to intense sputtering of electrode material, including tungsten as well as emitter. Thus, instant started fluorescent lamps often suffer from early failures due to coil fracture. Therefore, the investigation of tungsten erosion during instant start is necessary and was the main goal of this work. The density of neutral atomic tungsten is determined by laser-induced fluorescence (LIF) and optical emission spectroscopy measurements (OES). Investigations are performed on a low-pressure argon dc discharge and on commercial fluorescent lamps. To include the entire temperature profile along the electrode the diffuse and spot operation modes of the dc lamp are studied experimentally and theoretically. The measured dependencies of the cathode temperature along the coil on the discharge and heating parameters are compared with the calculated results. For the first time the tungsten erosion during instant start of commercial fluorescent lamps was experimentally investigated in this work. The erosion process could be related to sputtering. A reconstruction of the temporal evolution of the absolute tungsten population density of the ground state during the glow mode was presented. The sputtered tungsten density increases immediately with the ignition, reaches a maximum where the discharge contracts at the end of the glow mode, and decreases some milliseconds before the glow-to-arc transition takes place. The maximum tungsten density was observed within a

  14. The role of surface chemistry at ceramic/electrolyte intefaces in the generation of pulsed corona discharges in water using porous ceramic-coated rod electrodes

    Czech Academy of Sciences Publication Activity Database

    Lukeš, Petr; Člupek, Martin; Babický, Václav; Šunka, Pavel

    2009-01-01

    Roč. 6, č. 11 (2009), s. 719-728 ISSN 1612-8850 R&D Projects: GA AV ČR IAAX00430802 Institutional research plan: CEZ:AV0Z20430508 Keywords : non-thermal plasma * electrical discharge * water * surface chemistry Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 4.037, year: 2009 http://www3.interscience.wiley.com/cgi-bin/fulltext/122593644/PDFSTART

  15. N2(A3+u) behaviour in a N2-NO surface dielectric barrier discharge in the modulated ac regime at atmospheric pressure

    Czech Academy of Sciences Publication Activity Database

    Šimek, Milan; Ambrico, P. F.; Dilecce, G.; Prukner, Václav; Schmidt, Jiří; De Benedictis, S.

    2010-01-01

    Roč. 43, č. 12 (2010), s. 124003-124003 ISSN 0022-3727 R&D Projects: GA ČR GA202/08/1106 Institutional research plan: CEZ:AV0Z20430508 Keywords : surface barier discharge * laser induced fluorescence * metastables * nitric oxide Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 2.105, year: 2010 http://iopscience.iop.org/0022-3727/43/12/124003/pdf/0022-3727_43_12_124003.pdf

  16. Improvement of MRR and surface roughness during electrical discharge machining (EDM) using aluminum oxide powder mixed dielectric fluid

    Science.gov (United States)

    Khan, A. A.; Mohiuddin, A. K. M.; Latif, M. A. A.

    2018-01-01

    This paper discusses the effect of aluminium oxide (Al203) addition to dielectric fluid during electrical discharge machining (EDM). Aluminium oxide was added to the dielectric used in the EDM process to improve its performance when machining the stainless steel AISI 304, while copper was used as the electrode. Effect of the concentration of Al203 (0.3 mg/L) in dielectric fluid was compared with EDM without any addition of Al203. Surface quality of stainless steel and the material removal rate were investigated. Design of the experiment (DOE) was used for the experimental plan. Statistical analysis was done using ANOVA and then appropriate model was designated. The experimental results show that with dispersing of aluminium oxide in dielectric fluid surface roughness was improved while the material removal rate (MRR) was increased to some extent. These indicate the improvement of EDM performance using aluminium oxide in dielectric fluid. It was also found that with increase in pulse on time both MRR and surface roughness increase sharply.

  17. Study on the reforming of alcohols in a surface wave discharge (SWD) at atmospheric pressure

    International Nuclear Information System (INIS)

    Jimenez, M; Yubero, C; Calzada, M D

    2008-01-01

    Surface wave plasma at atmospheric pressure has been used to produce the decomposition of the alcohol molecules introduced into it, in order to obtain hydrogen. Four alcohols, methanol, ethanol, propanol and butanol, have been used for this purpose. Optical emission spectroscopy was the tool used to analyse the radiation emitted by the plasma. Hydrogen atoms and other species such as C 2 and CH in alcohols have been detected but no CO molecular bands. Also, a mass spectrometer has been used in order to detect molecular hydrogen production in methanol decomposition

  18. Fast enhancement on hydrophobicity of poplar wood surface using low-pressure dielectric barrier discharges (DBD) plasma

    International Nuclear Information System (INIS)

    Chen, Weimin; Zhou, Xiaoyan; Zhang, Xiaotao; Bian, Jie; Shi, Shukai; Nguyen, Thiphuong; Chen, Minzhi; Wan, Jinglin

    2017-01-01

    Highlights: • Plasma working under low pressure is easy to realize industrialization. • Enhancing process finished within 75 s. • Plasma treatment leads to the increase in equilibrium contact angle by 330%. • Tinfoil film with simple chemical structure was used to reveal the mechanism. - Abstract: The hydrophilicity of woody products leads to deformation and cracks, which greatly limits its applications. Low-pressure dielectric barrier discharge (DBD) plasma using hexamethyldisiloxane was applied in poplar wood surface to enhance the hydrophobicity. The chemical properties, micro-morphology, and contact angles of poplar wood surface before and after plasma treatment were investigated by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), x-ray photoelectron spectroscopy (XPS), scanning electron microscope and energy dispersive analysis of X-ray (SEM-EDX), atomic force microscopy (AFM), and optical contact angle measurement (OCA). Moreover, tinfoil film was used as the base to reveal the enhancement mechanism. The results showed that hexamethyldisiloxane monomer is first broken into several fragments with active sites and hydrophobic chemical groups. Meanwhile, plasma treatment results in the formation of free radicals and active sites in the poplar wood surface. Then, the fragments are reacted with free radicals and incorporated into the active sites to form a network structure based on the linkages of Si-O-Si and Si−O−C. Plasma treatment also leads to the formation of acicular nano-structure in poplar wood surface. These facts synergistically enhance the hydrophobicity of poplar wood surface, demonstrating the dramatically increase in the equilibrium contact angle by 330%.

  19. Fast enhancement on hydrophobicity of poplar wood surface using low-pressure dielectric barrier discharges (DBD) plasma

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Weimin [College of Materials Science and Engineering, Nanjing Forestry University, Nanjing 210037 (China); Jiangsu Engineering Research Center of Fast-growing Trees and Agri-fiber Materials, Nanjing 210037 (China); Nanjing Suman Plasma Technology Co., Ltd, Enterprise of Graduate Research Station of Jiangsu Province, No. 3 Youyihe Road, Nanjing 210001 (China); Zhou, Xiaoyan, E-mail: zhouxiaoyan@njfu.edu.cn [College of Materials Science and Engineering, Nanjing Forestry University, Nanjing 210037 (China); Jiangsu Engineering Research Center of Fast-growing Trees and Agri-fiber Materials, Nanjing 210037 (China); Zhang, Xiaotao [College of Materials Science and Engineering, Nanjing Forestry University, Nanjing 210037 (China); Jiangsu Engineering Research Center of Fast-growing Trees and Agri-fiber Materials, Nanjing 210037 (China); Bian, Jie [Nanjing Suman Plasma Technology Co., Ltd, Enterprise of Graduate Research Station of Jiangsu Province, No. 3 Youyihe Road, Nanjing 210001 (China); Shi, Shukai; Nguyen, Thiphuong; Chen, Minzhi [College of Materials Science and Engineering, Nanjing Forestry University, Nanjing 210037 (China); Jiangsu Engineering Research Center of Fast-growing Trees and Agri-fiber Materials, Nanjing 210037 (China); Wan, Jinglin [Nanjing Suman Plasma Technology Co., Ltd, Enterprise of Graduate Research Station of Jiangsu Province, No. 3 Youyihe Road, Nanjing 210001 (China)

    2017-06-15

    Highlights: • Plasma working under low pressure is easy to realize industrialization. • Enhancing process finished within 75 s. • Plasma treatment leads to the increase in equilibrium contact angle by 330%. • Tinfoil film with simple chemical structure was used to reveal the mechanism. - Abstract: The hydrophilicity of woody products leads to deformation and cracks, which greatly limits its applications. Low-pressure dielectric barrier discharge (DBD) plasma using hexamethyldisiloxane was applied in poplar wood surface to enhance the hydrophobicity. The chemical properties, micro-morphology, and contact angles of poplar wood surface before and after plasma treatment were investigated by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), x-ray photoelectron spectroscopy (XPS), scanning electron microscope and energy dispersive analysis of X-ray (SEM-EDX), atomic force microscopy (AFM), and optical contact angle measurement (OCA). Moreover, tinfoil film was used as the base to reveal the enhancement mechanism. The results showed that hexamethyldisiloxane monomer is first broken into several fragments with active sites and hydrophobic chemical groups. Meanwhile, plasma treatment results in the formation of free radicals and active sites in the poplar wood surface. Then, the fragments are reacted with free radicals and incorporated into the active sites to form a network structure based on the linkages of Si-O-Si and Si−O−C. Plasma treatment also leads to the formation of acicular nano-structure in poplar wood surface. These facts synergistically enhance the hydrophobicity of poplar wood surface, demonstrating the dramatically increase in the equilibrium contact angle by 330%.

  20. Evaluation of surface water treatment and discharge options for the Weldon Spring Site Remedial Action Project

    International Nuclear Information System (INIS)

    Goyette, M.L.; MacDonell, M.M.

    1992-01-01

    The US Department of Energy (DOE), under its Environmental Restoration and Waste Management Program, is responsible for conducting response actions at the Weldon Spring site in St. Charles County, Missouri. The site consists of two noncontiguous areas: (1) the chemical plant area, which includes four raffinate pits and two small ponds, and (2) a 3.6-ha (9-acre) quarry located about 6.4 km (4 mi) southwest of the chemical plant area. Both of these areas became chemically and radioactively contaminated as a result of processing and disposal activities that took place from the 1940s through 1960s. The Weldon Spring site, located about 48 km (30 mi) west of St. Louis, is listed on the National Priorities List of the US Environmental Protection Agency. Nitroaromatic explosives were processed by the Army at the chemical plant area during the 1940s, and radioactive materials were processed by DOE's predecessor agency (the Atomic Energy Commission) during the 1950s and 1960s. Overall remediation of the Weldon Spring site is being addressed through the Weldon Spring Site Remedial Action Project, and it consists of several components. One component is the management of radioactively and chemically contaminated surface water impoundments at the chemical plant area -- i.e., the four raffinate pits, Frog Pond, and Ash Pond which was addressed under a separate action and documented in an engineering evaluation/cost analysis report. This report discusses the evaluation of surface water treatment at the Weldon Spring site

  1. Mercury dosing solutions for fluorescent lamps

    Energy Technology Data Exchange (ETDEWEB)

    Corazza, A; Boffito, C [SAES Getters S.p.A., Viale Italia 77, Lainate (MI) 20020 (Italy)], E-mail: alessio_corazza@saes-group.com

    2008-07-21

    A review of the different technologies used to dose mercury in fluorescent lamps is presented. Conventional liquid mercury dosing is gradually being replaced with more reliable and environmentally friendly solutions that enable a significant reduction of the amount of mercury introduced in the lamp, so as to cope with more stringent regulations issued to minimize the environmental impact of exhausted lamps. This paper will review the most advanced novel methods to assure an accurate and fine dosing of mercury in fluorescent lamps, especially focusing on solutions based on the use of solid alloys.

  2. 30 CFR 20.8 - Class 1 lamps.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Class 1 lamps. 20.8 Section 20.8 Mineral... MINING PRODUCTS ELECTRIC MINE LAMPS OTHER THAN STANDARD CAP LAMPS § 20.8 Class 1 lamps. (a) Protection against explosion hazards. Unless properly designed, class 1 lamps present two sources of probable...

  3. 30 CFR 20.9 - Class 2 lamps.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Class 2 lamps. 20.9 Section 20.9 Mineral... MINING PRODUCTS ELECTRIC MINE LAMPS OTHER THAN STANDARD CAP LAMPS § 20.9 Class 2 lamps. (a) Safety. (1... section (No. 9, class 2 lamps), as experience and service prove to be necessary in the interests of safety. ...

  4. Initial site characterisation of a dissolved hydrocarbon groundwater plume discharging to a surface water environment

    International Nuclear Information System (INIS)

    Westbrook, S.J.; Commonwealth Scientific and Industrial Research Organisation Land and Water, Wembley, WA; Davis, G.B.; Rayner, J.L.; Fisher, S.J.; Clement, T.P.

    2000-01-01

    Preliminary characterisation of a dissolved hydrocarbon groundwater plume flowing towards a tidally- and seasonally-forced estuarine system has been completed at a site in Perth, Western Australia. Installation and sampling of multiport boreholes enabled fine scale (0.5-m) vertical definition of hydrocarbon concentrations. Vertical electrical conductivity profiles from multiport and spear probe sampling into the river sediments indicated that two groundwater/river water interfaces or dispersion zones are present: (a) an upper dispersion zone between brackish river water and groundwater, and (b) a lower interface between groundwater and deeper saline water. On-line water level loggers show that near-shore groundwater levels are also strongly influence by tidal oscillation. Results from the initial site characterisation will be used to plan further investigations of contaminated groundwater/surface water interactions and the biodegradation processes occurring at the site

  5. Three dimensional thermal pollution models. Volume 3: Free surface models. [waste heat discharge from power plants and effects on ecosystems

    Science.gov (United States)

    Lee, S. S.; Sengupta, S.

    1978-01-01

    Two sets of programs, named Nasum 2 and Nasum 3 are presented in detail. Nasum 2 is a far field formulation and is used without including the plant thermal discharge. Nasum 3 uses horizontal stretching to provide higher resolution at thermal discharge joints; and includes far field influences such as varying tides and ambient currents far from point of discharge.

  6. Radiation in controlled environments: influence of lamp type and filter material

    Science.gov (United States)

    Bubenheim, D. L.; Bugbee, B.; Salisbury, F. B.

    1988-01-01

    Radiation in controlled environments was characterized using fluorescent and various high-intensity-discharge (HID) lamps, including metal halide, low-pressure sodium, and high-pressure sodium as the radiation source. The effects of water, glass, or Plexiglas filters on radiation were determined. Photosynthetic photon flux (PPF, 400 to 700 nm), spectra (400 to 1000 nm), shortwave radiation (285-2800 nm), and total radiation (300 to 100,000 nm) were measured, and photosynthetically active radiation (PAR, 400 to 700 nm) and longwave radiation (2800 to 100,000 nm) were calculated. Measurement of PPF alone was not an adequate characterization of the radiation environment. Total radiant flux varied among lamp types at equal PPF. HID lamps provided a lower percentage of longwave radiation than fluorescent lamps, but, when HID lamps provided PPF levels greater than that possible with fluorescent lamps, the amount of longwave radiation was high. Water was the most effective longwave radiation filter. Glass and Plexiglas similarly filtered longwave more than shortwave radiation, but transmission of nonphotosynthetic shortwave radiation was less with Plexiglas than glass. The filter materials tested would not be expected to influence photomorphogenesis because radiation in the action spectrum of phytochrome was not altered, but this may not be the only pigment involved.

  7. Application of loop-mediated isothermal amplification (LAMP) of the ...

    African Journals Online (AJOL)

    Administrator

    2011-05-23

    LAMP) of the random insertion mobile element (RIME - LAMP) to diagnose camel Trypanosomiasis in Sudan. Extracted DNA from camels was used to detect Trypanosoma evansi infection in camels using RIME-LAMP technique.

  8. Heart pacemaker - discharge

    Science.gov (United States)

    Cardiac pacemaker implantation - discharge; Artificial pacemaker - discharge; Permanent pacemaker - discharge; Internal pacemaker - discharge; Cardiac resynchronization therapy - discharge; CRT - discharge; ...

  9. Design of Solar Street Lamp Control System Based on MPPT

    Science.gov (United States)

    Cui, Fengying

    This paper proposes a new solar street lamp control system which is composed of photovoltaic cell, controller, battery and load. In this system controller as the key part applies the microchip to achieve many functions. According to the nonlinear output characteristics of solar cell and the influence of environment, it uses the perturbation and observation (P&O) method to realize the maximum power point tracking (MPPT) and promotes the efficiency. In order to prolong the battery life the pulse width modulation (PWM) charge mode is selected to control the battery capacity and provent the battery from the state of over-charge and over-discharge. Meanwhile the function of temperature compensation, charge and discharge protection are set to improve the running safety and stability.

  10. Dispenser printed electroluminescent lamps on textiles for smart fabric applications

    Science.gov (United States)

    de Vos, Marc; Torah, Russel; Tudor, John

    2016-04-01

    Flexible electroluminescent (EL) lamps are fabricated onto woven textiles using a novel dispenser printing process. Dispenser printing utilizes pressurized air to deposit ink onto a substrate through a syringe and nozzle. This work demonstrates the first use of this technology to fabricate EL lamps. The luminance of the dispenser printed EL lamps is compared to screen-printed EL lamps, both printed on textile, and also commercial EL lamps on polyurethane film. The dispenser printed lamps are shown to have a 1.5 times higher luminance than the best performing commercially available lamp, and have a comparable performance to the screen-printed lamps.

  11. Dispenser printed electroluminescent lamps on textiles for smart fabric applications

    International Nuclear Information System (INIS)

    De Vos, Marc; Torah, Russel; Tudor, John

    2016-01-01

    Flexible electroluminescent (EL) lamps are fabricated onto woven textiles using a novel dispenser printing process. Dispenser printing utilizes pressurized air to deposit ink onto a substrate through a syringe and nozzle. This work demonstrates the first use of this technology to fabricate EL lamps. The luminance of the dispenser printed EL lamps is compared to screen-printed EL lamps, both printed on textile, and also commercial EL lamps on polyurethane film. The dispenser printed lamps are shown to have a 1.5 times higher luminance than the best performing commercially available lamp, and have a comparable performance to the screen-printed lamps. (paper)

  12. Performance and application of controlled temperature-gradient lamps in atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Gough, D.S.; Sullivan, J.V.

    1981-01-01

    An improved design of controlled temperature-gradient lamp (CTGL) is suitable for arsenic, cadmium, phosphorus, potassium, rubidium, selenium, sodium, sulphur and zinc. Intensity and linewidth measurements indicate that the CTGL is significantly more intense than an electrodeless discharge lamp (EDL) at the same linewidth. CTGL's also compare favourably with EDL's when used as light sources for a.a.s. Arsenic and selenium can be determined at very low concentrations (ng ml -1 ) by the hydride generation technique. Sulphur and phosphorus can be detected in the vacuum ultra-violet region using nitrogen-separated flames; the limits of detection are 13 and 10 μg ml -1 , respectively. (Auth.)

  13. Effect of a pulsed power supply on the spectral and electrical characteristics of HID lamps

    International Nuclear Information System (INIS)

    Chammam, Abdeljelil; Elloumi, Hatem; Mrabet, Brahim; Charrada, Kamel; Stambouli, Mongi; Damelincourt, Jean Jacques

    2005-01-01

    Results of spectral and photometric measurements are presented for pulsed power operated high intensity discharges (HIDs). This investigation is related to the application of a pulsed power supply for pile driving of HID lamps. Specifically, we are interested in controlling the spectral response radiation of visible and ultraviolet (UV) lines for tertiary treatment of water using UV radiation. Simulations based on a physical model of the lamps were conducted. These results relate to the radial temperature, line intensity and electrical properties (voltage, power and conductivity). Good agreement has been found between the results of the simulations and the experimental findings

  14. Surface Treatment of PEOT/PBT (55/45 with a Dielectric Barrier Discharge in Air, Helium, Argon and Nitrogen at Medium Pressure

    Directory of Open Access Journals (Sweden)

    Pieter Cools

    2018-03-01

    Full Text Available This work describes the surface modification of 300PEO-PEOT/PBT 55/45 thin films using a medium pressure dielectric barrier discharge system operated in argon, helium, nitrogen or dry air to improve cell-surface interactions of this established biomaterial. The first part of the paper describes the optimization of the plasma processing parameters using water contact angle goniometry. The optimized samples are then characterized for changes in surface topography and surface chemical composition using atomic force microscopy (AFM and X-ray fluorescence spectroscopy (XPS respectively. For all plasma treatments, a pronounced increase in surface wettability was observed, of which the extent is dependent on the used plasma discharge gas. Except for dry air, only minor changes in surface topography were noted, while XPS confirmed that the changes in wettability were mainly chemical in nature with the incorporation of 5–10% of extra oxygen as a variety of polar groups. Similarly, for the nitrogen plasma, 3.8% of nitrogen polar groups were additionally incorporated. Human foreskin fibroblast (HFF in vitro analysis showed that within the first 24 h after cell seeding, the effects on cell-surface interactivity were highly dependent on the used discharge gas, nitrogen plasma treatment being the most efficient. Differences between untreated and plasma-treated samples were less pronounced compared to other biodegradable materials, but a positive influence on cell adhesion and proliferation was still observed.

  15. Optimal set-up and surface finish characteristics in electrical discharge machining on Ti-5Al-2.5Sn using graphite

    Directory of Open Access Journals (Sweden)

    Md. Ashikur Rahman Khan

    2016-09-01

    Full Text Available In electrical discharge machining (EDM process which is an advance and non-conventional technique, the selection of machining parameters for achieving high machining performance is an important; however, very problematic task. In the current manuscript it was aimed to ascertain optimal machining set-up of EDM process related with fine surface finish. The die-sinking EDM was carried out using the both polarities (positive and negative of graphite electrode. The microstructure of the workpiece surface was investigated by scanning electronic microscopy. The negative polarity produces, on average, nearly double surface roughness than that with positive polarity. The surface microstructure is deteriorated as the discharge energy level increases for both polarities.

  16. N-2(A(3)Sigma(+)(u)) time evolution in N-2 atmospheric pressure surface dielectric barrier discharge driven by ac voltage under modulated regime

    Czech Academy of Sciences Publication Activity Database

    Ambrico, P. F.; Šimek, Milan; Dilecce, G.; De Benedictis, S.

    2009-01-01

    Roč. 94, č. 23 (2009), s. 231503-231503 ISSN 0003-6951 R&D Projects: GA ČR GA202/08/1106 Institutional research plan: CEZ:AV0Z20430508 Keywords : Atmospheric pressure surface-DBD * Nitrogen metastable * LIF * Optical emission spectroscopy Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 3.554, year: 2009

  17. Groundwater Discharge of Legacy Nitrogen to River Networks: Linking Regional Groundwater Models to Streambed Groundwater-Surface Water Exchange and Nitrogen Processing

    Science.gov (United States)

    Barclay, J. R.; Helton, A. M.; Briggs, M. A.; Starn, J. J.; Hunt, A.

    2017-12-01

    Despite years of management, excess nitrogen (N) is a pervasive problem in many aquatic ecosystems. More than half of surface water in the United States is derived from groundwater, and widespread N contamination in aquifers from decades of watershed N inputs suggest legacy N discharging from groundwater may contribute to contemporary N pollution problems in surface waters. Legacy N loads to streams and rivers are controlled by both regional scale flow paths and fine-scale processes that drive N transformations, such as groundwater-surface water exchange across steep redox gradients that occur at stream bed interfaces. Adequately incorporating these disparate scales is a challenge, but it is essential to understanding legacy N transport and making informed management decisions. We developed a regional groundwater flow model for the Farmington River, a HUC-8 basin that drains to the Long Island Sound, a coastal estuary that suffers from elevated N loads despite decades of management, to understand broad patterns of regional transport. To evaluate and refine the regional model, we used thermal infrared imagery paired with vertical temperature profiling to estimate groundwater discharge at the streambed interface. We also analyzed discharging groundwater for multiple N species to quantify fine scale patterns of N loading and transformation via denitrification at the streambed interface. Integrating regional and local estimates of groundwater discharge of legacy N to river networks should improve our ability to predict spatiotemporal patterns of legacy N loading to and transformation within surface waters.

  18. The dynamics of ozone generation and mode transition in air surface micro-discharge plasma at atmospheric pressure

    International Nuclear Information System (INIS)

    Shimizu, Tetsuji; Zimmermann, Julia L; Morfill, Gregor E; Sakiyama, Yukinori; Graves, David B

    2012-01-01

    We present the transient, dynamic behavior of ozone production in surface micro-discharge (SMD) plasma in ambient air. Ultraviolet absorption spectroscopy at 254 nm was used to measure the time development of ozone density in a confined volume. We observed that ozone density increases monotonically over 1000 ppm for at least a few minutes when the input power is lower than ∼0.1 W/cm 2 . Interestingly, when input power is higher than ∼0.1 W/cm 2 , ozone density starts to decrease in a few tens of seconds at a constant power density, showing a peak ozone density. A model calculation suggests that the ozone depletion at higher power density is caused by quenching reactions with nitrogen oxides that are in turn created by vibrationally excited nitrogen molecules reacting with O atoms. The observed mode transition is significantly different from classical ozone reactors in that the transition takes place over time at a constant power. In addition, we observed a positive correlation between time-averaged ozone density and the inactivation rate of Escherichia coli on adjacent agar plates, suggesting that ozone plays a key role in inactivating bacteria under the conditions considered here. (paper)

  19. Effects of wastewater discharge on formation of Fe plaque on root surface and radial oxygen loss of mangrove roots

    Energy Technology Data Exchange (ETDEWEB)

    Pi, N. [Department of Biology and Chemistry, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong, Kowloon (Hong Kong); Tam, N.F.Y., E-mail: bhntam@cityu.edu.h [Department of Biology and Chemistry, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong, Kowloon (Hong Kong); Wong, M.H. [Croucher Institute for Environmental Sciences, Baptist University of Hong Kong, Kowloon Tong, Kowloon (Hong Kong)

    2010-02-15

    Effects of wastewater discharge on radial oxygen loss (ROL), formation of iron (Fe) plaque on root surface, and their correlations in Bruguiera gymnorrhiza (L.) Poir and Excoecaria agallocha L. were investigated. ROL along a lateral root increased more rapidly in control than that in strong wastewater (with pollutant concentrations ten times of that in municipal sewage, 10NW) treatment, but less Fe plaque was formed in control for both plants. For B. gymnorrhiza receiving 10NW, Fe plaque formation was more at basal and mature zones than at root tip, while opposite trend was shown in E. agallocha. At day 0, the correlation between ROL and Fe plaque was insignificant, but negative and positive correlations were found in 10NW and control, respectively, at day 105, suggesting that more ROL was induced leading to more Fe plaque. However, excess Fe plaque also served as a 'barrier' to prevent excessive ROL in 10NW plants. - Correlation between Fe plaque formation and ROL.

  20. A study of plasma facing tungsten components with electrical discharge machined surface exposed to cyclic thermal loads

    International Nuclear Information System (INIS)

    Seki, Yohji; Ezato, Koichiro; Suzuki, Satoshi; Yokoyama, Kenji; Yamada, Hirokazu; Hirayama, Tomoyuki

    2016-01-01

    Through R&D for a plasma facing units (PFUs) in an outer vertical target of an ITER full-tungsten (W) divertor, Japan Atomic Energy Agency succeeded in demonstrating the durability of the W divertor shaped by an electrical discharge machining (EDM). To prevent melting of W armors in the PFUs, an adequate technology to meet requirements of a geometrical shape and a tolerance is one of the most important key issues in a manufacturing process. From the necessity, the EDM has been evaluated to control the final shape of the W armor. Though the EDM was known to be advantages such as an easy workability, a potential disadvantage of presence of micro-cracks on the W surface appeared. In order to examine a potential effect of the micro-crack on a heat removal durability, a high heat flux testing was carried out for the W divertor mock-up with the polish and the EDM. As the result, all of the W armors endured the repetitive heat load of 1000 cycles at an absorbed heat flux of more than 20 MW/m 2 , which strongly encourages the realization of the PFUs of the ITER full-W divertor with the various geometrical shape and the high accuracy tolerance.

  1. Ion activation energy delivered to wounds by atmospheric pressure dielectric-barrier discharges: sputtering of lipid-like surfaces

    International Nuclear Information System (INIS)

    Babaeva, Natalia Yu; Kushner, Mark J; Ning Ning; Graves, David B

    2012-01-01

    The application of atmospheric pressure plasmas to human tissue has been shown to have therapeutic effects for wound healing and in treatment of skin diseases. These effects are attributed to production of UV photon fluxes, electric fields and beneficial radicals which intersect with biological reaction chains, and to energetic ions bombarding the surface. In this paper we report on results from a computational investigation of the ion energy and angular distributions (IEADs) in a dielectric-barrier discharge sustained in air incident directly on cell membranes for small dry and wet wounds in human skin. We found that ion energies in excess of 20-30 eV can be delivered onto cell membranes of dry wounds, and up to 60 eV onto the liquid interface of the wet wound. The details of the IEADs depend on the orientation of the cell membrane and on the relative location of the plasma streamer to the wound. Using results from a molecular dynamics simulation of ion sputter probabilities of typical lipid-like material, we show that prolonged exposure of the cell membrane to such IEADs can produce significant carbon removal. (paper)

  2. Ion activation energy delivered to wounds by atmospheric pressure dielectric-barrier discharges: sputtering of lipid-like surfaces

    Science.gov (United States)

    Babaeva, Natalia Yu; Ning, Ning; Graves, David B.; Kushner, Mark J.

    2012-03-01

    The application of atmospheric pressure plasmas to human tissue has been shown to have therapeutic effects for wound healing and in treatment of skin diseases. These effects are attributed to production of UV photon fluxes, electric fields and beneficial radicals which intersect with biological reaction chains, and to energetic ions bombarding the surface. In this paper we report on results from a computational investigation of the ion energy and angular distributions (IEADs) in a dielectric-barrier discharge sustained in air incident directly on cell membranes for small dry and wet wounds in human skin. We found that ion energies in excess of 20-30 eV can be delivered onto cell membranes of dry wounds, and up to 60 eV onto the liquid interface of the wet wound. The details of the IEADs depend on the orientation of the cell membrane and on the relative location of the plasma streamer to the wound. Using results from a molecular dynamics simulation of ion sputter probabilities of typical lipid-like material, we show that prolonged exposure of the cell membrane to such IEADs can produce significant carbon removal.

  3. Aqueous reactive species induced by a PCB surface micro-discharge air plasma device: a quantitative study

    Science.gov (United States)

    Chen, Chen; Li, Fanying; Chen, Hai-Lan; Kong, Michael G.

    2017-11-01

    This paper presents a quantitative investigation on aqueous reactive species induced by air plasma generated from a printed circuit board surface micro-discharge (SMD) device. Under the conditions amenable for proliferation of mammalian cells, concentrations of ten types of reactive oxygen and nitrogen species (RONS) in phosphate buffering solution (PBS) are measured by chemical fluorescent assays and electron spin resonance spectroscopy (ESR). Results show that concentrations of several detected RNS (NO2- , NO3- , peroxynitrites, and NO2\\centerdot ) are higher than those of ROS (H2O2, O2\\centerdot - , and 1O2) in the air plasma treated solution. Concentrations of NO3- can reach 150 times of H2O2 with 60 s plasma treatment. For short-lived species, the air plasma generates more copious peroxynitrite than other RONS including NO2\\centerdot , O2\\centerdot - , 1O2, and N{{O}\\centerdot } in PBS. In addition, the existence of reaction between H2O2 and NO2- /HNO2 to produce peroxynitrite is verified by the chemical scavenger experiments. The reaction relations between detected RONS are also discussed.

  4. Self-organized pattern on the surface of a metal anode in low-pressure DC discharge

    Science.gov (United States)

    Yaqi, YANG; Weiguo, LI

    2018-03-01

    Self-organization phenomena on the surface of a metal electrode in low-pressure DC discharge is studied. In this paper, we carry out laboratory investigations of self-organization in a low-pressure test platform for 100-200 mm rod-plane gaps with a needle tip, conical tip and hemispherical tip within 1-10 kPa. The factors influencing the pattern profile are the pressure value, gap length and shape of the electrode, and a variety of pattern structures are observed by changing these factors. With increasing pressure, first the pattern diameter increases and then decreases. With the needle tip, layer structure, single-ring structure and double-ring structure are displayed successively with increasing pressure. With the conical tip, the ring-like structure gradually forms separate spots with increasing pressure. With the hemispherical tip, there are anode spots inside the ring structure. With the increase of gap length, the diameter of the self-organized pattern increases and the profile of the pattern changes. The development process of the pattern contains three key stages: pattern enlargement, pattern stabilization and pattern shrink.

  5. Cadmium removal from urban stormwater runoff via bioretention technology and effluent risk assessment for discharge to surface water

    Science.gov (United States)

    Wang, Jianlong; Zhang, Pingping; Yang, Liqiong; Huang, Tao

    2016-02-01

    Bioretention technology, a low-impact development stormwater management measure, was evaluated for its ability to remove heavy metals (specifically cadmium, Cd) from urban stormwater runoff. Fine sand, zeolite, sand and quartz sand were selected as composite bioretention media. The effects of these materials on the removal efficiency, chemical forms, and accumulation and migration characteristics of Cd were examined in laboratory scale bioretention columns. Heretofore, few studies have examined the removal of Cd by bioretention. A five-step sequential extraction method, a single-contamination index method, and an empirical migration equation were used in the experiments. The average Cd removal efficiency of quartz sand approached 99%, and removal by the other media all exceeded 90%. The media types markedly affected the forms of Cd found in the columns as well as its vertical migration rate. The Cd accumulated in the four media was mainly in residual form; moreover, accumulation of Cd occurred mainly in the surface layer of the bioretention column. The migration depth of Cd in the four media increased with elapsed time, in the following sequence: zeolite > quartz sand > fine sand > sand. In contrast, the migration rate decreased with elapsed time, and the migration rate of Cd was lowest in sand (0.015 m per annum over the first ten years). The comprehensive risk index analysis indicated that the risk arising from Cd discharge to surface water was "intermediate", and that the degree of risk was lowest in sand, then quartz sand, zeolite, and fine sand in sequence. These results indicate that the adsorption and accumulation of Cd in the four media are more significant than the migration of Cd. In addition, the results of Cd risk assessment for the effluent indicate that each of the four media can serve as long-term adsorption material in a bioretention facility for purifying stormwater runoff.

  6. Cadmium removal from urban stormwater runoff via bioretention technology and effluent risk assessment for discharge to surface water.

    Science.gov (United States)

    Wang, Jianlong; Zhang, Pingping; Yang, Liqiong; Huang, Tao

    2016-01-01

    Bioretention technology, a low-impact development stormwater management measure, was evaluated for its ability to remove heavy metals (specifically cadmium, Cd) from urban stormwater runoff. Fine sand, zeolite, sand and quartz sand were selected as composite bioretention media. The effects of these materials on the removal efficiency, chemical forms, and accumulation and migration characteristics of Cd were examined in laboratory scale bioretention columns. Heretofore, few studies have examined the removal of Cd by bioretention. A five-step sequential extraction method, a single-contamination index method, and an empirical migration equation were used in the experiments. The average Cd removal efficiency of quartz sand approached 99%, and removal by the other media all exceeded 90%. The media types markedly affected the forms of Cd found in the columns as well as its vertical migration rate. The Cd accumulated in the four media was mainly in residual form; moreover, accumulation of Cd occurred mainly in the surface layer of the bioretention column. The migration depth of Cd in the four media increased with elapsed time, in the following sequence: zeolite>quartz sand>fine sand>sand. In contrast, the migration rate decreased with elapsed time, and the migration rate of Cd was lowest in sand (0.015 m per annum over the first ten years). The comprehensive risk index analysis indicated that the risk arising from Cd discharge to surface water was "intermediate", and that the degree of risk was lowest in sand, then quartz sand, zeolite, and fine sand in sequence. These results indicate that the adsorption and accumulation of Cd in the four media are more significant than the migration of Cd. In addition, the results of Cd risk assessment for the effluent indicate that each of the four media can serve as long-term adsorption material in a bioretention facility for purifying stormwater runoff. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Recent advances in incoherent light sources in the vacuum-ultraviolet (88-200nm) based on electric discharge plasmas

    International Nuclear Information System (INIS)

    Ward, B.K.; Carman, R.J.; Mildren, R.P.; Kane, D.M.

    2004-01-01

    Full text: Rare-gas and rare gas-halide excimer lamps are powerful, frequency agile, mercury-free sources of high power, narrow band (10nm-30nm), UV and VUV radiation covering the wavelength range 88nm-320nm. A very efficient and practically convenient method of excitation is achieved using the dielectric barrier discharge (DBD). In the DBD, charge build-up on an insulating (dielectric) barrier at one or both of the electrodes provides an intrinsic mechanism for quenching the discharge before the transition to a high current discharge. The UV/VUV output from rare-gas DBD lamps is highly monochromatic, derived predominantly from 2nd excimer continuum, with negligible output at visible and infrared wavelengths. For DBD lamps powered by sinusoidal voltage waveforms (50Hz-100kHz), the electrical to optical conversion efficiency typically reaches 10-20%. The discharge structure consists of multiple transient plasma aments that occur stochastically in time during the discharge cycle leading to VUV output pulses with irregular spacing and amplitude. We have shown, however, that using discrete high-voltage pulses of relatively short duration, produces a short-lived homogeneous discharge that generates much higher peak power from short (sub-microsecond) VUV output pulses, with an additional increase (two- fold) in overall efficiency. Conversion efficiencies between 40-60% have also been reported for short-pulse excitation techniques. Efficient generation of pulsed, high peak-power VUV output is of interest for a broad range of applications in time-resolved spectroscopy, photo-lithography, materials processing and surface modification/cleaning, killing of micro- organisms and bacteria, sterilization, and in ozone production for water purification

  8. Geometric Modelling of Octagonal Lamp Poles

    Science.gov (United States)

    Chan, T. O.; Lichti, D. D.

    2014-06-01

    Lamp poles are one of the most abundant highway and community components in modern cities. Their supporting parts are primarily tapered octagonal cones specifically designed for wind resistance. The geometry and the positions of the lamp poles are important information for various applications. For example, they are important to monitoring deformation of aged lamp poles, maintaining an efficient highway GIS system, and also facilitating possible feature-based calibration of mobile LiDAR systems. In this paper, we present a novel geometric model for octagonal lamp poles. The model consists of seven parameters in which a rotation about the z-axis is included, and points are constrained by the trigonometric property of 2D octagons after applying the rotations. For the geometric fitting of the lamp pole point cloud captured by a terrestrial LiDAR, accurate initial parameter values are essential. They can be estimated by first fitting the points to a circular cone model and this is followed by some basic point cloud processing techniques. The model was verified by fitting both simulated and real data. The real data includes several lamp pole point clouds captured by: (1) Faro Focus 3D and (2) Velodyne HDL-32E. The fitting results using the proposed model are promising, and up to 2.9 mm improvement in fitting accuracy was realized for the real lamp pole point clouds compared to using the conventional circular cone model. The overall result suggests that the proposed model is appropriate and rigorous.

  9. Lamp system for uniform semiconductor wafer heating

    Science.gov (United States)

    Zapata, Luis E.; Hackel, Lloyd

    2001-01-01

    A lamp system with a very soft high-intensity output is provided over a large area by water cooling a long-arc lamp inside a diffuse reflector of polytetrafluorethylene (PTFE) and titanium dioxide (TiO.sub.2) white pigment. The water is kept clean and pure by a one micron particulate filter and an activated charcoal/ultraviolet irradiation system that circulates and de-ionizes and biologically sterilizes the coolant water at all times, even when the long-arc lamp is off.

  10. A pulse generator for xenon lamps

    CERN Document Server

    Janata, E

    2002-01-01

    A pulse generator is described, which enhances the analyzing light emitted from a xenon lamp as used in kinetic photospectrometry experiments. The lamp current is increased to 600 A for a duration of 3 ms; the current is constant within +-0.2% during a time interval of 2 ms. Because of instabilities of the lamp arc during pulsing, the use of the enhanced light source is limited to measuring times up to 500 mu s. The enhancement in light intensity depends on the wavelength and amounts to more than 400-fold in the UV-region.

  11. Research on Lessening of Bonding Effects Between the Metallic and Non-Metallic Surfaces Through the Graphite Films Deposited with Pulsed Electrical Discharges Process

    Science.gov (United States)

    Marin, L.; Topala, P.

    2017-06-01

    The paper presents the results of experimental research on the physics of natural graphite film formation, the establishment of chemical composition and functional properties of the graphite films, formed on metal surfaces, as a result of the action of plasma in the air environment, at a normal pressure, under the electrical discharge in impulse conditions (EDI). The researchings were performed in the frame of doctoral thesis “Research on lessening of the bonding effects between the metallic and nonmetallic surfaces through the graphite films” and aimed to identify the phenomena that occur at the interface metal/ film of graphite, and to identify also the technological applications that it may have the surface treatment for submitting the films of graphite on metallic surfaces achieved through an innovative process of electrical pulsed discharges. After the research works from the PhD theme above mentioned, a number of interesting properties of graphite pellicle have been identified ie reducing of metal surface polarity. This led to drastic decreases for the values of adhesion when bonding of metal surfaces was performed using a structural polyurethane adhesive designed by ICECHIM. Following the thermo-gravimetric analysis, performed of the graphite film obtained by process of electrical pulsed discharges, have been also discovered other interesting properties for this, ie reversible mass additions at specific values of the working temperature Chemical and scanning electron microscopy analysis have revealed that on the metallic surface subjected to electrical pulsed discharges process, outside the graphite film, it is also obtained a series of spatial formation composed of carbon atoms fullerenes type which are responsible for the phenomenon of addition of mass.

  12. Optical and electrical characteristics of a single surface DBD micro-discharge produced in atmospheric-pressure nitrogen and synthetic air

    Czech Academy of Sciences Publication Activity Database

    Šimek, Milan; Prukner, Václav; Schmidt, Jiří

    2011-01-01

    Roč. 20, č. 2 (2011), 025009-025009 ISSN 0963-0252. [European Sectional Conference on Atomic and Molecular Physics of Ionized Gases (ESCAMPIGXX)/20th./. Novi Sad, SERBIA, 13.07.2010-17.07.2010] R&D Projects: GA ČR GA202/08/1106 Institutional research plan: CEZ:AV0Z20430508 Keywords : surface barier discharge * streamer Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 2.521, year: 2011 http://iopscience.iop.org/0963-0252/20/2/025009/pdf/0963-0252_20_2_025009.pdf

  13. ICCD microscopic imaging of a single micro-discharge in surface coplanar DBD geometry: determination of the luminous diameter of N-2 and Ar streamers

    Czech Academy of Sciences Publication Activity Database

    Šimek, Milan; Ambrico, P. F.; Prukner, Václav

    2011-01-01

    Roč. 20, č. 2 (2011), 025010-025010 ISSN 0963-0252. [European Sectional Conference on Atomic and Molecular Physics of Ionized Gases (ESCAMPIGXX)/20th./. Novi Sad, SERBIA, 13.07.2010-17.07.2010] R&D Projects: GA ČR GA202/08/1106 Institutional research plan: CEZ:AV0Z20430508 Keywords : surface barier discharge * streamer * imaging Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 2.521, year: 2011 http://iopscience.iop.org/0963-0252/20/2/025010/pdf/0963-0252_20_2_025010.pdf

  14. Effect of machining parameters on surface integrity of silicon carbide ceramic using end electric discharge milling and mechanical grinding hybrid machining

    International Nuclear Information System (INIS)

    Ji, Renjie; Liu, Yonghong; Zhang, Yanzhen; Cai, Baoping; Li, Xiaopeng; Zheng, Chao

    2013-01-01

    A novel hybrid process that integrates end electric discharge (ED) milling and mechanical grinding is proposed. The process is able to effectively machine a large surface area on SiC ceramic with good surface quality and fine working environmental practice. The polarity, pulse on-time, and peak current are varied to explore their effects on the surface integrity, such as surface morphology, surface roughness, micro-cracks, and composition on the machined surface. The results show that positive tool polarity, short pulse on-time, and low peak current cause a fine surface finish. During the hybrid machining of SiC ceramic, the material is mainly removed by end ED milling at rough machining mode, whereas it is mainly removed by mechanical grinding at finish machining mode. Moreover, the material from the tool can transfer to the workpiece, and a combination reaction takes place during machining.

  15. On slit-lamp microscopy.

    Science.gov (United States)

    Schmidt, T A

    1975-11-21

    Theoretically the contact lens with a refractive power of -64 dioptres is superior to the concave pre-set lens (Hruby lens) or the convex lens (Bayadi). In practice the results are as follows: With the convex lens the examination of the vitreous is unsatisfactory. The reversed image with the convex lens will become familiar with some experience as one will also get used to the mirror images of the three-mirror contact lens. However, the abnormal curvature of the image is really a nuisance. On the other hand the large field of view is an advantage. The convex lens is only practically useful when it can be firmly attached to the slit-lamp microscope, as otherwise the new adjustment necessary for searching the fundus is too difficult. Attachment to the microscope is also of advantage with the Hruby lens. The concave contact lens of 64 dioptres is best suited for detailed examination of vitreous and fundus and for measurements. When no value is placed on a minute examination and a quick simple orientation suffices, the concave pre-set lens (Hruby lens) has the advantage that the lens does not have to be placed on the eye. If it is centred to the middle axis of the microscope, it facilitates especially quick observation. There will be cases where the pre-set lens will be the only answer, especially shortly after an operation or with very sensitive patients. Furthermore, the Hruby lens is preferable to the Bayadi lens because the vitreous can be better examined. The Hruby lens is also advantageous for examination of the region in the middle, lateral periphery of the fundus, 30 degrees - 60 degrees, and is superior in this area to the simple concave contact lens. The Bayadi lens seems to us only indicated for fundus examination of extremely high myopes. There it definitely offers advantages over and above the concave lens. For the most peripheral fundus, expecially below and above, the three-mirror lens with its modification is so far the best method. Especially for

  16. Self-Consolidation and Surface Modification of Mechanical Alloyed Ti-25.0 at.% Al Powder Mixture by Using an Electro-Discharge Technique

    Directory of Open Access Journals (Sweden)

    Chang S.Y.

    2017-06-01

    Full Text Available Electrical discharges using a capacitance of 450 μF at 0.5, 1.0, and 1.5 kJ input energies were applied in a N2 atmosphere to obtain the mechanical alloyed Ti3Al powder without applying any external pressure. A solid bulk of nanostructured Ti3Al was obtained as short as 160 μsec by the Electrical discharge. At the same time, the surface has been modified into the form of Ti and Al nitrides due to the diffusion process of nitrogen to the surface. The input energy was found to be the most important parameter to affect the formation of a solid core and surface chemistry of the compact.

  17. LAMP Project Case Study--Materials

    Science.gov (United States)

    Coward, E. M.

    1977-01-01

    A field test of the materials unit from the LAMP Project for low motivated secondary students is discussed. Facilities, students, teaching methodology, and the evaluation of the situation are described.

  18. LED lamp power management system and method

    Science.gov (United States)

    Gaines, James; Clauberg, Bernd; Van Erp, Josephus A. M.

    2013-03-19

    An LED lamp power management system and method including an LED lamp having an LED controller 58; a plurality of LED channels 60 operably connected to the LED controller 58, each of the plurality of LED channels 60 having a channel switch 62 in series with at least one shunted LED circuit 83, the shunted LED circuit 83 having a shunt switch 68 in parallel with an LED source 80. The LED controller 58 reduces power loss in one of the channel switch 62 and the shunt switch 68 when LED lamp electronics power loss (P.sub.loss) exceeds an LED lamp electronics power loss limit (P.sub.lim); and each of the channel switches 62 receives a channel switch control signal 63 from the LED controller 58 and each of the shunt switches 68 receives a shunt switch control signal 69 from the LED controller 58.

  19. Lamp of adjustable spectrum for photographic usage

    Science.gov (United States)

    Mazikowski, Adam; Feldzensztajn, Mateusz

    2017-08-01

    Photography is a unique rapidly growing interdisciplinary field encompassing aspects of science, art and technology. Expectations of photographers are steadily increasing with the development of technology. One of the areas playing a crucial role in photography is lighting. Consequently, several types of light sources for photographic use have been developed. The ongoing research in this field concentrates on lamps with tunable CCT (Correlated Color Temperature). In this paper, we present a lamp, which emission spectrum can be tailored without affecting the output luminous ux. Intended for photographic uses, the lamp is based on an integrating sphere and a selection of LEDs. As the LED drivers, DC-DC converters controlled by a Raspberry PI were applied. Design process, including the selection of LED wavelengths, is presented. Output characteristics of the lamp were measured using the setup containing the spectrometer. The results of these experiments show good agreement with the spectrum set on the microcomputer.

  20. CALiPER Retail Lamps Study 3

    Energy Technology Data Exchange (ETDEWEB)

    Royer, Michael P. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Beeson, Tracy A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2014-02-01

    The CALiPER program first began investigating LED lamps sold at retail stores in 2010, purchasing 33 products from eight retailers and covering six product categories. The findings revealed a fragmented marketplace, with large disparities in performance of different products, accuracy of manufacturer claims, and offerings from different retail outlets. Although there were some good products, looking back many would not be considered viable competitors to other available options, with too little lumen output, not high enough efficacy, or poor color quality. CALiPER took another look in late 2011purchasing 38 products of five different types from nine retailers and the improvement was marked. Performance was up; retailer claims were more accurate; and the price per lumen and price per unit efficacy were down, although the price per product had not changed much. Nonetheless, there was still plenty of room for improvement, with the performance of LED lamps not yet reaching that of well-established classes of conventional lamps (e.g., 75 W incandescent A19 lamps). Since the second retail lamp study was published in early 2012, there has been substantial progress in all aspects of LED lamps available from retailers. To document this progress, CALiPER again purchased a sample of lamps from retail stores 46 products in total, focusing on A19, PAR30, and MR16 lamps but instead of a random sample, sought to select products to answer specific hypotheses about performance. These hypotheses focused on expanding ranges of LED equivalency, the accuracy of lifetime claims, efficacy and price trends, as well as changes to product designs. Among other results, key findings include: There are now very good LED options to compete with 60 W, 75 W, and 100 W incandescent A19 lamps, and 75 W halogen PAR30 lamps. MR16 lamps have shown less progress, but there are now acceptable alternatives to 35 W, 12 V halogen MR16 lamps and 50 W, 120 V halogen MR16 lamps for some applications. Other

  1. High-durability surface-discharge flash X-ray tube driven by a two-stage Marx pulser

    International Nuclear Information System (INIS)

    Shikoda, Arimitsu; Sato, Eiichi; Kimura, Shingo; Oizumi, Teiji; Tamakawa, Yoshiharu; Yanagisawa, Toru

    1993-01-01

    The authors developed a high-durability flash X-ray tube with a plate-shaped ferrite cathode for the use in the field of biomedical engineering and technology. The surface-discharge cathode was very useful for generating stable flash X rays. This flash X-ray generator consisted of the following essential components: a high-voltage power supply, an energy-storage condenser of 97 nF, a two-stage Marx type pulser, an oil diffusion pump, and a flash X-ray tube. This X-ray tube was of a diode which was connected to the turbo molecular pump and had plate-shaped anode and cathode electrodes. The cathode electrode was made of ferrite, and its edge was covered with a thin gold film by means of the spattering in order to decrease contact resistance. The space between the anode and cathode electrodes could be regulated from the outside of the X-ray tube. The two condensers in Marx circuit were charged from 50 to 70 kV by a power supply, and the condensers were connected in series after closing a gap switch. Thus the maximum output voltages from the pulser were about two times the charged voltages. In this experiment, the maximum tube voltage and the current were about 110 kV and 0.8 kA, respectively. The pulse widths were less than 140 ns, and the maximum X-ray intensity was 1.27 μC/kg at 0.5 m per pulse. The size of the focal spot and the maximum repetition rate were about 2 x 2.5 mm and 50 Hz (fps), respectively

  2. Decontamination Efficiency of a DBD Lamp Containing an UV-C Emitting Phosphor.

    Science.gov (United States)

    Caillier, Bruno; Caiut, José Maurício Almeida; Muja, Cristina; Demoucron, Julien; Mauricot, Robert; Dexpert-Ghys, Jeanette; Guillot, Philippe

    2015-01-01

    Among different physical and chemical agents, the UV radiation appears to be an important route for inactivation of resistant microorganisms. The present study introduces a new mercury-free Dielectric Barrier Discharge (DBD) flat lamp, where the biocide action comes from the UV emission produced by rare-earth phosphor obtained by spray pyrolysis, following plasma excitation. In this study, the emission intensity of the prototype lamp is tuned by controlling gas pressure and electrical power, 500 mbar and 15 W, corresponding to optimal conditions. In order to characterize the prototype lamp, the energetic output, temperature increase following lamp ignition and ozone production of the source were measured. The bactericidal experiments carried out showed excellent results for several gram-positive and gram-negative bacterial strains, thus demonstrating the high decontamination efficiency of the DBD flat lamp. Finally, the study of the external morphology of the microorganisms after the exposure to the UV emission suggested that other mechanisms than the bacterial DNA damage could be involved in the inactivation process. © 2015 The American Society of Photobiology.

  3. Sterilization and Decontamination of Surfaces Contaminated With Biological and Chemical Warfare Agents Using Atmospheric Pressure Plasma Discharges

    National Research Council Canada - National Science Library

    Garate, Eusebio

    1999-01-01

    ... based on the application of an atmospheric pressure plasma. We used both a DC corona and dielectric barrier discharge for the sterilization tests which were conducted on a variety of substrates including metals and chemically resistant fabrics...

  4. Fast Surface Temperature Measurement of Teflon Propellant in Pulsed Ablative Discharges Using HgCdTe Photovoltaic Cells (PREPRINT)

    National Research Council Canada - National Science Library

    Antonsen, Erik L; Burton, Rodney L; Reed, Garrett A; Spanjers, Gregory G

    2006-01-01

    ... ablative discharge with Teflon(TradeMark) as the ablated material. Analysis is used to derive a governing equation for detector output voltage for materials with wavelength dependent emissivity...

  5. User manual for SPLASH (Single Panel Lamp and Shroud Helper).

    Energy Technology Data Exchange (ETDEWEB)

    Larsen, Marvin Elwood

    2006-02-01

    The radiant heat test facility develops test sets providing well-characterized thermal environments, often representing fires. Many of the components and procedures have become standardized to such an extent that the development of a specialized design tool to determine optimal configurations for radiant heat experiments was appropriate. SPLASH (Single Panel Lamp and Shroud Helper) is that tool. SPLASH is implemented as a user-friendly, Windows-based program that allows a designer to describe a test setup in terms of parameters such as number of lamps, power, position, and separation distance. This document is a user manual for that software. Any incidental descriptions of theory are only for the purpose of defining the model inputs. The theory for the underlying model is described in SAND2005-2947 (Ref. [1]). SPLASH provides a graphical user interface to define lamp panel and shroud designs parametrically, solves the resulting radiation enclosure problem for up to 2500 surfaces, and provides post-processing to facilitate understanding and documentation of analyzed designs.

  6. Influence of geometry of the discharge interval on distribution of ion and electron streams at surface of the Penning source cathode

    International Nuclear Information System (INIS)

    Egiazaryan, G.A.; Khachatrian, Zh.B.; Badalyan, E.S.; Ter-Gevorgyan, E.I.; Hovhannisyan, V.N.

    2006-01-01

    In the discharge of oscillating electrons, the mechanism of the processes, which controls the distribution of the ion and electron streams over the cathode surface, is investigated experimentally. The influence of the length of the discharge interval on value and distribution of the ion and electron streams is analyzed. The distribution both of ion and electron streams at the cathode surface is determined at different conditions of the discharge. It is shown that for given values of the anode diameter d a =31 mm and the gas pressure P=5x10 -5 Torr, the intensive stream of positive ions falls entirely on the cathode central area in the whole interval of the anode length variation (l a =1-11 cm). At the cathode, the ion current reaches the maximal value at a certain (optimal) value of the anode length that, in turn, depends on the anode voltage U a . The intensive stream of longitudinal electrons forms in the short anodes only (l a =2.5-3.5 cm) and depending on the choice of the discharge regime, may fall both on central and middle parts of the cathode

  7. X-ray measurements from the cathode surface of glow discharge tube used as a compact X-ray fluorescence instrument

    International Nuclear Information System (INIS)

    Tsuji, K.; Wagatsuma, K.; Yamaguchi, S.; Nagata, S.; Hirokawa, K.

    1998-01-01

    As previously reported, when a high-voltage is applied to a Grimm glow discharge tube, high-energy electrons emitted from the cathode surface bombard the glass window, leading to X-ray emissions from the window. In this study, we have applied an energy-dispersive X-ray analysis to detect X-rays from the cathode which are excited by X-rays emitted from the glass window. Thus, we have proposed to utilize this glow discharge tube as a compact X-ray fluorescence instrument, to which both the X-ray emission source and the sample are directly attached. This compact X-ray fluorescence instrument has the same advantages of easy maintenance, exchangeable target and sample, and simple construction. The quantitative determination of Si, Ti, and Mn in Fe-Si, Fe-Ti, and Fe-Mn alloys was demonstrated with the detection limits of 21, 150 and 420 ppm, respectively. The X-ray measurement form the cathode is a useful method to directly monitor the cathode surface during the glow discharge process. This would be applied to understand and control the glow discharge processes. Moreover, the X-ray diffraction peaks as well as the fluorescent X-ray peaks were observed, indicating that the structure analysis of the cathode material would also be possible. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  8. Characterization and study of the thermodynamic equilibrium departure of an argon plasma flame produced by a surface-wave sustained discharge

    Science.gov (United States)

    Calzada, M. D.; Sáez, M.; García, M. C.

    2000-07-01

    Surface wave induced plasma (SWP) is a particular class of microwave induced plasma. It is used in atomic emission and mass spectrometry as a source of excitation for the elemental analysis of samples in analytical chemistry. This discharge is mainly used at powers less than 300 W. At such low power, an efficient process of desolvation, atomization, excitation and ionization of the analyte can only be reached provided the density of power absorbed in the discharge is large. This requires a plasma whose volume increases very little with increasing absorbed power. At atmospheric pressure in the SWP, such a volume limitation can be achieved by having the plasma extending into ambient air in the form of a flame (open air discharge). This article presents the results of the experimental characterization and study of the degree of thermodynamic equilibrium of an argon plasma flame produced by a surfatron. The values of the plasma parameters and b(p) (departure from equilibrium) parameter for the ArI levels show that the discharge is a two-temperature plasma. By comparing the results with those obtained for a classical surface-wave plasma column, it can be concluded that the plasma in flame is more suited to be used as a source of excitation in analytical chemistry, due to its higher electronic density and temperatures values.

  9. Formation of methanol and formate in Wistar rats after oral administration of methylated rapeseed oil: a fuel for lamps.

    Science.gov (United States)

    Prinz, Soenke; Tiefenbach, Birgit; Kobow, Manfred; Hennighausen, Gerhard

    2006-01-01

    Low viscosity, low surface tension and low volatility are features of lamp oils contributing to chemical pneumonia that can occur after ingestion. Because lamp oils with such physico-chemical properties have been forbidden in the European Community from July 2000 onward, industry has developed different products, mostly based upon rapeseed oil. The fatty acids of these oils are methylated. The goal of this study is to demonstrate whether methanol is released in Wistar rats after oral administration of these new lamp oils. Applying a dose of 1 ml/kg body weight lamp oil, peak levels of methanol were reached at 1 h (54.6 +/- 18.6 microg/ml), methanol was not detectable at 8 h. After the instillation of 4 ml/kg of lamp oil peak levels occurred at 2 h (189.2 +/- 24.9 microg/ml). The metabolite formate increased with time, and was highest at 8 h after the administration of 1 ml/kg body weight lamp oil (32.9 +/- 2.9 microg/ml). Starvation before the administration of 1 ml/kg body weight lamp oil decreased the methanol serum concentrations, but the differences were not significant. Based upon these experimental data in rats, it can be concluded that in humans small amounts of methanol will be released after ingestion of these lamp oils. As these products are mainly ingested accidentally by toddlers in low quantities, the risk of a methanol intoxication seems to be very low.

  10. Slit-lamp calibration, crucial but neglected

    Directory of Open Access Journals (Sweden)

    Lutfah Rif’ati

    2013-05-01

    Full Text Available AbstrakLatar belakang: Kalibrasi berkala alat diagnostik sangat esensial untuk diagnosis yang akurat. Riset fasilitas kesehatan (Rifaskes 2011 mengumpulkan data termasuk kalibrasi lampu celah (slit-lamp pada sampel rumah sakit (RS di Indonesia. Tujuan analisis ialah untuk mengidentifikasi faktor dominan yang berpengaruh terhadap pelaksanaan kalibrasi berkala lampu celah di RS.Metode: Analisis memakai sebagian data Rifaskes 2011 di antara 442 RS yang menyediakan layanan kesehatan mata. Risiko relatif dipergunakan untuk menilai kemungkinan tidak dilakukannya kalibrasi lampu celah di RS.Hasil: Di antara 248 RS sampel yang memenuhi kriteria inklusi, hanya 25,8% RS yang melakukan kalibrasi lampu celah tepat waktu. Dibandingkan dengan rumah sakit yang dimiliki oleh Badan Usaha Milik Negara (BUMN, rumah sakit yang dimiliki lembaga lain memiliki risiko yang lebih tinggi tidak mengkalibrasi lampu celah. Menurut tipe RS, RS non-pendidikan dibandingkan dengan RS -pendidikan berisiko 40% lebih tinggi tidak mengkalibrasi lampu [risiko relatif suaian (RRa = 1,40; 95% interval kepercayaan (CI = 1,02-1,91].Kesimpulan: Kalibrasi tepat waktu lampu-celah masih menjadi masalah di sebagian besar RS. Dibandingkan dengan rumah sakit yang dimiliki oleh BUMN, rumah sakit yang dimiliki oleh instansi lain berisiko yang lebih tinggi tidak mengkalibrasi lampu celah. (Health Science Indones 2012;2:xx-xxKata kunci:kalibrasi, lampu celah, rumah sakitAbstractBackground: Periodical diagnostic tool calibration is essential for accurate diagnosis. Health Facilities Research (Rifaskes in 2011 collected data on the slit-lamp calibration of all registered general hospitals in Indonesia.Methods: Analysis using a part Rifaskes 2011 data among 442 hospitals that provide eye health services. Relative risk was used to assess the risk of performing calibration slit lamp.Results: Out of 442 hospitals, 248 hospitals met the inclusion study criteria, and only 25.8% calibrating the slit-lamp

  11. The evaluations of the influence of surface conductivity to the energy of particles in discharge channel and interaction force in contact charging process

    Energy Technology Data Exchange (ETDEWEB)

    Alisoy, H.Z. [Department of Electric and Electronics Engineering, Inonu University, 44280 Malatya (Turkey)]. E-mail: halis@inonu.edu.tr; Alisoy, G.T. [Department of Mathematics Education, Inonu University, 44280 Malatya (Turkey); Sahin, A. [Department of Physics, Inonu University, 44280 Malatya (Turkey); Yeroglu, C. [Department of Electric and Electronics Engineering, Inonu University, 44280 Malatya (Turkey)

    2006-12-18

    In this Letter, we present some analytical expressions by using the equations of electric field, inside and outside of a cylindrical void, taking the surface conductivity into consideration. We apply the obtained expressions to the high voltage insulation and ion electron technology, such as: (i) energies of charged particles occurring in discharge channel in accordance with Townsend approach; (ii) interaction force between the dielectric particle and the electrode for DC and AC cases.

  12. Study of the surface of GaAs after etching in high-frequency and glow discharge plasma by atomic force microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Dunaev, A. V., E-mail: dunaev-80@mail.ru; Murin, D. B.; Pivovarenok, S. A. [Ivanovo State University of Chemistry and Technology (Russian Federation)

    2016-02-15

    The quality of the surface of a semiconductor structure after plasma-chemical etching in plasma of HCl/Ar, HCl/Cl{sub 2}, HCl/H{sub 2} mixtures, and freon R12 plasma is studied. It is shown that the optimal combination of the etch rate and surface roughness is achieved in the hydrogen chloride and argon mixture. In mixtures with hydrogen, the etch rates are too low for high surface quality; in mixtures with chlorine, the surface roughness exceeds technologically acceptable values due to high etch rates. The high-frequency discharge in freon R12 can be effectively used to etch semiconductors, providing technologically acceptable interaction rates, while retaining a uniform and clean surface.

  13. Optimized positioning of autonomous surgical lamps

    Science.gov (United States)

    Teuber, Jörn; Weller, Rene; Kikinis, Ron; Oldhafer, Karl-Jürgen; Lipp, Michael J.; Zachmann, Gabriel

    2017-03-01

    We consider the problem of finding automatically optimal positions of surgical lamps throughout the whole surgical procedure, where we assume that future lamps could be robotized. We propose a two-tiered optimization technique for the real-time autonomous positioning of those robotized surgical lamps. Typically, finding optimal positions for surgical lamps is a multi-dimensional problem with several, in part conflicting, objectives, such as optimal lighting conditions at every point in time while minimizing the movement of the lamps in order to avoid distractions of the surgeon. Consequently, we use multi-objective optimization (MOO) to find optimal positions in real-time during the entire surgery. Due to the conflicting objectives, there is usually not a single optimal solution for such kinds of problems, but a set of solutions that realizes a Pareto-front. When our algorithm selects a solution from this set it additionally has to consider the individual preferences of the surgeon. This is a highly non-trivial task because the relationship between the solution and the parameters is not obvious. We have developed a novel meta-optimization that considers exactly this challenge. It delivers an easy to understand set of presets for the parameters and allows a balance between the lamp movement and lamp obstruction. This metaoptimization can be pre-computed for different kinds of operations and it then used by our online optimization for the selection of the appropriate Pareto solution. Both optimization approaches use data obtained by a depth camera that captures the surgical site but also the environment around the operating table. We have evaluated our algorithms with data recorded during a real open abdominal surgery. It is available for use for scientific purposes. The results show that our meta-optimization produces viable parameter sets for different parts of an intervention even when trained on a small portion of it.

  14. Simulation of the influence high-frequency (2 MHz) capacitive gas discharge and magnetic field on the plasma sheath near a surface in hypersonic gas flow

    International Nuclear Information System (INIS)

    Schweigert, I. V.

    2012-01-01

    The plasma sheath near the surface of a hypersonic aircraft formed under associative ionization behind the shock front shields the transmission and reception of radio signals. Using two-dimensional kinetic particle-in-cell simulations, we consider the change in plasma-sheath parameters near a flat surface in a hypersonic flow under the action of electrical and magnetic fields. The combined action of a high-frequency 2-MHz capacitive discharge, a constant voltage, and a magnetic field on the plasma sheath allows the local electron density to be reduced manyfold.

  15. The influence of de-Maxwellization on a fluorescent lamp simulation

    Energy Technology Data Exchange (ETDEWEB)

    Hartgers, A; Dijk, J van; Heijden, H W P van der; Mullen, J A M van der [Department of Physics, Eindhoven University of Technology, PO Box 513, 5600 MB Eindhoven (Netherlands)

    2003-09-21

    A simple three electron temperature model was applied to a one-dimensional, fully self-consistent model of a positive column discharge, as typically found in fluorescent lamps. It was shown that this model yields results that are in good agreement with reality, regarding important parameters such as the electrical conductivity, the electron temperature and the amount of radiation produced, and that it constitutes a significant improvement over a calculation based on a Maxwellian electron energy distribution function.

  16. Plasma parameters in the vicinity of the quartz window of a low pressure surface wave discharge produced in O2

    DEFF Research Database (Denmark)

    Nakao, S.; Stamate, Eugen; Sugai, H.

    2007-01-01

    Plasma parameters in the vicinity of the dielectric window of a low density, microwave discharge produced in 0, at 915 N/FHz are investigated by a spherical probe and optical emission spectroscopy while the microwave field distribution is measured by a spectrum analyzer. The electron energy distr...... from the dielectric. (c) 2006 Elsevier B.V. All rights reserved....

  17. Application of ICP-OES for Evaluating Energy Extraction and Production Wastewater Discharge Impacts on Surface Waters in Western Pennsylvania

    Science.gov (United States)

    Oil and gas extraction and coal-fired electrical power generating stations produce wastewaters that are treated and discharged to rivers in Western Pennsylvania with public drinking water system (PDWS) intakes. Inductively coupled plasma optical emission spectroscopy (ICP-OES) w...

  18. Retail Lamps Study 3.1: Dimming, Flicker, and Power Quality Characteristics of LED A Lamps

    Energy Technology Data Exchange (ETDEWEB)

    Royer, Michael P. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Poplawski, Michael E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Brown, Charles C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2014-12-01

    To date, all three reports in the retail lamps series have focused on basic performance parameters, such as lumen output, efficacy, and color quality. This report goes a step further, examining the photoelectric characteristics (i.e., dimming and flicker) of a subset of lamps from CALiPER Retails Lamps Study 3. Specifically, this report focuses on the dimming, power quality, and flicker characteristics of 14 LED A lamps, as controlled by four different retail-available dimmers. The results demonstrate notable variation across the various lamps, but little variation between the four dimmers. Overall, the LED lamps: ~tended to have higher relative light output compared to the incandescent and halogen benchmark at the same dimmer output signal (RMS voltage). The lamps’ dimming curves (i.e., the relationship between control signal and relative light output) ranged from linear to very similar to the square-law curve typical of an incandescent lamp. ~generally exhibited symmetrical behavior—the same dimming curve—when measured proceeding from maximum to minimum or minimum to maximum control signal. ~mostly dimmed below 10% of full light output, with some exceptions for specific lamp and dimmer combinations ~exhibited a range of flicker characteristics, with many comparing favorably to the level typical of a magnetically-ballasted fluorescent lamp through at least a majority of the dimming range. ~ always exceeded the relative (normalized) efficacy over the dimming range of the benchmark lamps, which rapidly decline in efficacy when they are dimmed. This report generally does not attempt to rank the performance of one product compared to another, but instead focuses on the collective performance of the group versus conventional incandescent or halogen lamps, the performance of which is likely to be the baseline for a majority of consumers. Undoubtedly, some LED lamps perform better—or more similar to conventional lamps—than others. Some perform desirably for one

  19. Impact of wastewater treatment plant discharge of lidocaine, tramadol, venlafaxine and their metabolites on the quality of surface waters and groundwater.

    Science.gov (United States)

    Rúa-Gómez, Paola C; Püttmann, Wilhelm

    2012-05-01

    The presence of the anesthetic lidocaine (LDC), the analgesic tramadol (TRA), the antidepressant venlafaxine (VEN) and the metabolites O-desmethyltramadol (ODT) and O-desmethylvenlafaxine (ODV) was investigated in wastewater treatment plant (WWTP) effluents, in surface waters and in groundwater. The analytes were detected in all effluent samples and in only 64% of the surface water samples. The mean concentrations of the analytes in effluent samples from WWTPs with wastewater from only households and hospitals were 107 (LDC), 757 (TRA), 122 (ODT), 160 (VEN) and 637 ng L(-1) (ODV), while the mean concentrations in effluents from WWTPs treating additionally wastewater from pharmaceutical industries as indirect dischargers were for some pharmaceuticals clearly higher. WWTP effluents were identified as important sources of the analyzed pharmaceuticals and their metabolites in surface waters. The concentrations of the compounds found in surface waters ranged from Infiltration of the target analytes into groundwater was not observed.

  20. Shoulder replacement - discharge

    Science.gov (United States)

    Total shoulder arthroplasty - discharge; Endoprosthetic shoulder replacement - discharge; Partial shoulder replacement - discharge; Partial shoulder arthroplasty - discharge; Replacement - shoulder - discharge; Arthroplasty - shoulder - discharge

  1. Optimization and Surface Modification of Al-6351 Alloy Using SiC-Cu Green Compact Electrode by Electro Discharge Coating Process

    Science.gov (United States)

    Chakraborty, Sujoy; Kar, Siddhartha; Dey, Vidyut; Ghosh, Subrata Kumar

    2017-06-01

    This paper introduces the surface modification of Al-6351 alloy by green compact SiC-Cu electrode using electro-discharge coating (EDC) process. A Taguchi L-16 orthogonal array is employed to investigate the process by varying tool parameters like composition and compaction load and electro-discharge machining (EDM) parameters like pulse-on time and peak current. Material deposition rate (MDR), tool wear rate (TWR) and surface roughness (SR) are measured on the coated specimens. An optimum condition is achieved by formulating overall evaluation criteria (OEC), which combines multi-objective task into a single index. The signal-to-noise (S/N) ratio, and the analysis of variance (ANOVA) is employed to investigate the effect of relevant process parameters. A confirmation test is conducted based on optimal process parameters and experimental results are provided to illustrate the effectiveness of this approach. The modified surface is characterized by optical microscope and X-ray diffraction (XRD) analysis. XRD analysis of the deposited layer confirmed the transfer of tool materials to the work surface and formation of inter-metallic phases. The micro-hardness of the resulting composite layer is also measured which is 1.5-3 times more than work material’s one and highest layer thickness (LT) of 83.644μm has been successfully achieved.

  2. Experimental and modelling study of the effect of airflow orientation with respect to strip electrode on ozone production of surface dielectric barrier discharge

    Science.gov (United States)

    Mikeš, J.; Pekárek, S.; Soukup, I.

    2016-11-01

    This study examines the effect of airflow orientation with respect to the strip active electrode on concentration of ozone and nitrogen dioxide produced in a planar generator based on the surface dielectric barrier discharge. The orientation of the airflow was tested in parallel and perpendicular with respect to the strips. It was found that in the investigated range of average discharge power, the ozone concentration increases approximately by 25% when airflow was oriented in parallel with respect to the strips in comparison with perpendicular orientation of the airflow. Similarly the increase of nitrogen dioxide concentration was observed for parallel orientation of the airflow with respect to the strips in comparison with the perpendicular orientation of the airflow. Within the range of wavelengths from 250 to 1100 nm, the changes of intensities of spectral lines associated with airflow orientation have been observed. A 3D numerical model describing ion trajectories and airflow patterns have also been developed.

  3. Spontaneous Formation of Titanium Nitride on the Surface of a Ti Rod Induced by Electro-Discharge-Heat-Treatment in an N2 Atmosphere

    Directory of Open Access Journals (Sweden)

    Lee W.H.

    2017-06-01

    Full Text Available A single pulse of 2.0 to 3.5 kJ of input energy from a 450 mF capacitor was applied to a commercially pure Ti rod in a N2 atmosphere. The surface of the Ti rod transformed from TiO2 into titanium nitride in times as short as 159 msec, providing a bimodal morphology of the cross-section. A much higher value of hardness that was observed at the edge of the cross-section was attributed to nitrogen-induced solid-solution hardening that occurred during the electrical discharge process. The activation energy (Ea for the diffusion process was estimated to be approximately 86.9 kJ/mol. Results show that the electrical discharge process is a possible potential method for the nitriding of Ti; advantages include a short processing time and control of the nitrided layer without dimensional changes.

  4. LASERS: Parameters of a trigatron-driven low-pulse-repetition-rate TEA CO2 laser preionised by a surface corona discharge

    Science.gov (United States)

    Aram, M.; Behjat, A.; Shabanzadeh, M.; Mansori, F.

    2007-01-01

    The design of a TEA CO2 laser with UV preionisation by a surface corona discharge is described and the dependences of its average output energy on the gas-flow rate, discharge voltage and pulse repetition rate are presented. The scheme of the electric circuit and the geometry of the pre-ionisation system are considered. The electric circuit is designed to produce only impulse voltage difference between the laser electrodes. The triggering system of the trigatron is used to prevent the appearance of the arc. The dependences of the current, voltage and average output energy on the gas-mixture composition and applied voltages at a low pulse repetition rate are presented. The central output wavelength of the laser was measured with an IR spectrometer. Lasing at two adjacent vibrational-rotational transitions of the CO2 molecule was observed, which demonstrates the possibility of simultaneous lasing at several lines.

  5. Parameters of a trigatron-driven low-pulse-repetition-rate TEA CO2 laser preionised by a surface corona discharge

    International Nuclear Information System (INIS)

    Aram, M; Shabanzadeh, M; Mansori, F; Behjat, A

    2007-01-01

    The design of a TEA CO 2 laser with UV preionisation by a surface corona discharge is described and the dependences of its average output energy on the gas-flow rate, discharge voltage and pulse repetition rate are presented. The scheme of the electric circuit and the geometry of the pre-ionisation system are considered. The electric circuit is designed to produce only impulse voltage difference between the laser electrodes. The triggering system of the trigatron is used to prevent the appearance of the arc. The dependences of the current, voltage and average output energy on the gas-mixture composition and applied voltages at a low pulse repetition rate are presented. The central output wavelength of the laser was measured with an IR spectrometer. Lasing at two adjacent vibrational-rotational transitions of the CO 2 molecule was observed, which demonstrates the possibility of simultaneous lasing at several lines. (lasers)

  6. Preoperative study of the surface ECG for the prognosis of atrial fibrillation maze surgery outcome at discharge

    International Nuclear Information System (INIS)

    Hernández, Antonio; Rieta, José Joaquín; Alcaraz, Raúl; Hornero, Fernando

    2014-01-01

    The Cox-maze surgery is an effective procedure for terminating atrial fibrillation (AF) in patients requiring open-heart surgery associated with another heart disease. After the intervention, regardless of the patient's rhythm, all are treated with oral anticoagulants and antiarrhythmic drugs prior to discharge. Furthermore, patients maintaining AF before discharge could also be treated with electrical cardioversion (ECV). In view of this, a preoperative prognosis of the patient's rhythm at discharge would be helpful for optimizing drug therapy planning as well as for advancing ECV therapy. This work analyzes 30 preoperative electrocardiograms (ECGs) from patients suffering from AF in order to predict the Cox-maze surgery outcome at discharge. Two different characteristics of the AF pattern have been studied. On the one hand, the atrial activity (AA) organization, which provides information about the number of propagating wavelets in the atria, was investigated. AA organization has been successfully used in previous studies related to spontaneous reversion of paroxysmal AF and to the outcome of ECV. To assess organization, the dominant atrial frequency (DAF) and sample entropy (SampEn) have been computed. On the other hand, the second characteristic studied was the fibrillatory wave (f-wave) amplitude, which has been demonstrated to be a valuable indicator of the Cox-maze surgery outcome in previous studies. Moreover, this parameter has been obtained through a new methodology, based on computing the f-wave average power (fWP). Finally, all the computed indices were combined in a decision tree in order to improve prediction capability. Results for the DAF yielded a sensitivity (Se), a specificity (Sp) and an accuracy (Acc) of 61.54%, 82.35% and 73.33%, respectively. For SampEn the values were 69.23%, 76.00% and 73.33%, respectively, and for fWP they were 92.31%, 82.35% and 86.67%, respectively. Finally, the decision tree combining the three parameters

  7. Laboratory Evaluation of LED T8 Replacement Lamp Products

    Energy Technology Data Exchange (ETDEWEB)

    Richman, Eric E.; Kinzey, Bruce R.; Miller, Naomi J.

    2011-05-23

    A report on a lab setting analysis involving LED lamps intended to directly replace T8 fluorescent lamps (4') showing light output, power, and economic comparisons with other fluorescent options.

  8. 21 CFR 866.2600 - Wood's fluorescent lamp.

    Science.gov (United States)

    2010-04-01

    ...) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Microbiology Devices § 866.2600 Wood's fluorescent lamp. (a) Identification. A Wood's fluorescent lamp is a device intended for medical purposes to detect...

  9. Increase in the Hydrophilicity and Lewis Acid-Base Properties of Solid Surfaces Achieved by Electric Gliding Discharge in Humid Air: Effects on Bacterial Adherence

    International Nuclear Information System (INIS)

    Kamgang, J. O.; Brisset, J.-L.; Naitali, M.; Herry, J.-M.; Bellon-Fontaine, M.-N.; Briandet, R.

    2009-01-01

    This study addressed the effects of treatment with gliding discharge plasma on the surface properties of solid materials, as well as the consequences concerning adherence of a model bacterium. As evaluated by contact angles with selected liquids, plasma treatment caused an increase in surface hydrophilicity and in the Lewis acid-base components of the surface energy of all materials tested. These modifications were more marked for low density polyethylene and stainless steel than for polytetrafluoroethylene. After treatment, the hydrophilicity of the materials remained relatively stable for at least 20 days. Moreover, analysis of the topography of the materials by atomic force microscopy revealed that the roughness of both polymers was reduced by glidarc plasma treatment. As a result of all these modifications, solid substrates were activated towards micro-organisms and the adherence of S. epidermidis, a negatively charged Lewis-base and mildly hydrophilic strain selected as the model, was increased in almost all the cases tested. (plasma technology)

  10. Investigation of material removal rate and surface roughness during wire electrical discharge machining (WEDM of Inconel 625 super alloy by cryogenic treated tool electrode

    Directory of Open Access Journals (Sweden)

    Ashish Goyal

    2017-10-01

    Full Text Available The present investigation focuses the effect of process parameters on material removal rate (MRR and surface roughness (Ra in wire electric discharge machining of Inconel 625. Machining was done by using a normal zinc coated wire and cryogenic treated zinc coated wire. The experiments were performed by considering different process parameters viz. tool electrode, current intensity, pulse on time, pulse off time, wire feed and wire tension. The thickness of work material and dia. of wire are kept constant. Taguchi L18 (21 * 35 orthogonal array of experimental design is used to perform the experiments. Analysis of variance (ANOVA is employed to optimize the material removal rate and surface roughness. Based on analysis it is found that pulse on time, tool electrode and current intensity are the significant parameters that affect the material removal rate and surface roughness. The scanning electron microscopy (SEM are used to identify the microstructure of the machined work piece.

  11. Short Communication: Electrical energy saving through lamps ...

    African Journals Online (AJOL)

    Modern Buildings of all types relies heavily on the use of electrical energy. This energy has to be properly utilized in order to avoid many problems both to the electric utilities supply companies and also to the consumer. This paper presents energy saving through replacement process of conventional electric lamps known ...

  12. 100 years of Wood's lamp revised

    NARCIS (Netherlands)

    Klatte, J. L.; van der Beek, N.; Kemperman, P. M. J. H.

    2015-01-01

    The Wood's lamp is a diagnostic tool in dermatology. Unfortunately, this useful tool is often overlooked in the busy and hectic outdoor dermatology clinic. To emphasize its value in modern dermatology, we present an updated review of the principles and applications and shed new light on its proper

  13. 15 KJ FLASH LAMP, POWER CONDITIONING UNIT DESIGNED FOR SAFTY, RELIABILITY & MANUFACTURABILITY*

    Energy Technology Data Exchange (ETDEWEB)

    James, G; Merritt, B; Dreifuerst, G; Strickland, S

    2007-08-07

    A 15kJoule, Flash Lamp Power Conditioning Unit has been successfully designed, developed, and deployed in the National Ignition Facility (NIF) Preamplifier Modules (PAM). The primary design philosophy of this power conditioning unit (PCU) is safety, reliability, and manufacturability. Cost reduction over commercially equivalent systems was also achieved through an easily manufactured packaging design optimized to meet NIF requirements. While still maintaining low cost, the PCU design includes a robust control system, fault diagnostic system, and safety features. The pulsed power design includes 6 PFN modules, each including a dual series injection trigger transformer, that drive a total of 12 flash lamp loads. The lamps are individually triggered via a 20kV pulse produced by a 1kV, MCT switched capacitive discharge unit on the primary side of the trigger transformer. The remote control interface includes an embedded controller that captures flash lamp current wave forms and fault status for each shot. The embedded controller provides the flexibility of remotely adjusting both the main drive voltage from 1.6 to 2.5 kV and the trigger voltage from 0 to 20 kV.

  14. 30 CFR 75.1703 - Portable electric lamps.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Portable electric lamps. 75.1703 Section 75... HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Miscellaneous § 75.1703 Portable electric lamps. [Statutory Provisions] Persons underground shall use only permissible electric lamps approved by the...

  15. 21 CFR 878.4630 - Ultraviolet lamp for dermatologic disorders.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ultraviolet lamp for dermatologic disorders. 878.4630 Section 878.4630 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... Ultraviolet lamp for dermatologic disorders. (a) Identification. An ultraviolet lamp for dermatologic...

  16. 46 CFR 92.05-10 - Lamp room construction.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Lamp room construction. 92.05-10 Section 92.05-10... CONSTRUCTION AND ARRANGEMENT General Fire Protection § 92.05-10 Lamp room construction. (a) Lamp, paint, and oil lockers and similar compartments shall be constructed of steel or shall be wholly lined with metal. ...

  17. Formation of nanostructures induced by capillary-discharge soft X-ray laser on BaF2 surfaces

    Science.gov (United States)

    Zhao, Yongpeng; Cui, Huaiyu; Zhang, Shuqing; Zhang, Wenhong; Li, Wei

    2017-02-01

    BaF2 was ablated by a capillary-discharge pumped soft X-ray laser at 46.9 nm focused by a toroidal mirror at a grazing incidence of 83°. The damaged area, induced by both single and multiple laser pulses, was determined to be covered with fringe-like nanostructures with spacings of approximately 400 nm and mastoid nanostructures with diameters of approximately 600 nm. In this study, we analyze the morphology of the detected damage patterns and discuss the damage mechanism. Results indicate that the depth of the nanostructures varies with different pulse numbers and laser power densities.

  18. Influence of a single lightning discharge on the intensity of an air electric field and acoustic emission of near-surface rocks

    Directory of Open Access Journals (Sweden)

    S. E. Smirnov

    2012-10-01

    Full Text Available The effect was observed as a sharp fall of the electric potential gradient from +80 V m−1 down to –21 V m−1. After that the field returned to its normal level according to the formula of the capacitor discharge with 17 s characteristic time. Simultaneously, the response of the acoustic emission of surface rocks in the range of frequencies between 6.5 kHz and 11 kHz was evaluated.

  19. Coplanar surface barrier discharge ignited in water vapor—a selective source of OH radicals proved by (TA)LIF measurement

    Science.gov (United States)

    Procházka, V.; Tučeková, Z.; Dvořák, P.; Kováčik, D.; Slavíček, P.; Zahoranová, A.; Voráč, J.

    2018-01-01

    Coplanar dielectric barrier discharge (DBD) was ignited in pure water vapor at atmospheric pressure in order to generate highly oxidizing plasma with one specific type of reactive radicals. In order to prevent water condensation the used plasma reactor was heated to 120 {}\\circ C. The composition of the radical species in the discharge was studied by methods based on laser-induced fluorescence (LIF) and compared with analogous measurements realized in the same coplanar DBD ignited in air. Fast collisional processes and laser-surface interaction were taken into account during LIF data processing. It was found that coplanar DBD ignited in water vapor produces hydroxyl (OH) radicals with concentration in the order of 1020 m-3, which is 10× higher than the value measured in discharge in humid air (40% relative humidity at 21 {}\\circ C). The concentration of atomic hydrogen radicals in the DBD ignited in water vapor was below the detection limit, which proves that the generation of oxidizing plasma with dominance of one specific type of reactive radicals was achieved. The temporal evolution, spatial distribution, power dependence and rotational temperature of the OH radicals was determined in the DBD ignited in both water vapor and air.

  20. Nucleation and initial growth of atomic layer deposited titanium oxide determined by spectroscopic ellipsometry and the effect of pretreatment by surface barrier discharge

    Energy Technology Data Exchange (ETDEWEB)

    Cameron, David C., E-mail: dccameron@mail.muni.cz [R& D Centre for Low-Cost Plasma and Nanotechnology Surface Modification, Masaryk University, Kotlářská 267/2, 611 37 Brno (Czech Republic); Krumpolec, Richard, E-mail: richard.krumpolec@fmph.uniba.sk [Department of Experimental Physics, Faculty of Mathematics, Physics and Informatics, Comenius University, Mlynská dolina, 842 4 Bratislava (Slovakia); Ivanova, Tatiana V., E-mail: tatiana.ivanova@lut.fi [ASTRaL team, Laboratory of Green Chemistry, Lappeenranta University of Technology, Sammonkatu 12, 50130 Mikkeli (Finland); Homola, Tomáš, E-mail: tomas.homola@mail.muni.cz [R& D Centre for Low-Cost Plasma and Nanotechnology Surface Modification, Masaryk University, Kotlářská 267/2, 611 37 Brno (Czech Republic); Černák, Mirko, E-mail: cernak@physics.muni.cz [R& D Centre for Low-Cost Plasma and Nanotechnology Surface Modification, Masaryk University, Kotlářská 267/2, 611 37 Brno (Czech Republic)

    2015-08-01

    Highlights: • Spectroscopic ellipsometry shows initial nucleation and growth process in atomic layer deposited titanium dioxide. • Quantum confinement effects were used to measure evolution of crystallite size. • Crystallite surface density can be extracted from ellipsometric surface roughness data and crystallite size. • Pretreatment of silicon substrates by diffuse coplanar surface barrier discharge has only minor effects on titanium dioxide film nucleation and growth. - Abstract: This paper reports on the use of spectroscopic ellipsometry to characterise the initial nucleation stage of the atomic layer deposition of the anatase phase of titanium dioxide on silicon substrates. Careful control and analysis of the ellipsometric measurements enables the determination of the evolution of crystallite diameter and surface density in the nucleation stage before a continuous film is formed. This growth behaviour is in line with atomic force microscopy measurements of the crystallite size. The crystallite diameter is a linear function of the number of ALD cycles with a slope of approximately 1.7 Å cycle{sup −1} which is equivalent to a layer growth rate of 0.85 Å cycle{sup −1} consistent with a ripening process which increases the crystallite size while reducing their density. The crystallite density decreases from ∼3 × 10{sup 17} m{sup −3} in the initial nucleation stages to ∼3 × 10{sup 15} m{sup −3} before the film becomes continuous. The effect of exposing the substrate to a diffuse coplanar surface barrier discharge in an air atmosphere before deposition was measured and only small differences were found: the plasma treated samples were slightly rougher in the initial stages and required a greater number of cycles to form a continuous film (∼80) compared to the untreated films (∼50). A thicker layer of native oxide was found after plasma treatment.

  1. CALiPER Retail Lamps Study 3.1: Dimming, Flicker, and Power Quality Characteristics of LED A Lamps

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2014-12-31

    This CALiPER report examines the characteristics of a subset of lamps from CALiPER Retail Lamps Study 3 in more detail. Specifically, it focuses on the dimming, power quality, and flicker characteristics of 14 LED A lamps, as controlled by four different retail-available dimmers.

  2. [Remote Slit Lamp Microscope Consultation System Based on Web].

    Science.gov (United States)

    Chen, Junfa; Zhuo, Yong; Liu, Zuguo; Chen, Yanping

    2015-11-01

    To realize the remote operation of the slit lamp microscope for department of ophthalmology consultation, and visual display the real-time status of remote slit lamp microscope, a remote slit lamp microscope consultation system based on B/S structure is designed and implemented. Through framing the slit lamp microscope on the website system, the realtime acquisition and transmission of remote control and image data is realized. The three dimensional model of the slit lamp microscope is established and rendered on the web by using WebGL technology. The practical application results can well show the real-time interactive of the remote consultation system.

  3. Energy-saving lamps - the hit in horticulture

    Energy Technology Data Exchange (ETDEWEB)

    Domke, O.

    1984-01-01

    In lighting chains, it is not possible to exchange energy saving lamps for light bulbs (market gardening). In the shop sector, however, there will be a number of useful purposes for them (important: long life). Energy-saving lamps function like fluorescent lamps. They can be exchanged for ordinary bulbs because they have the same screw-in system. Economy lamps and fluorescent tubes use approximately 75% less electricity than comparable bulbs, and at the same time, they last about five times as long. What sort of lamp is used should be carefully considered according to what it is to be used for. (orig.).

  4. High sensitive and high temporal and spatial resolved image of reactive species in atmospheric pressure surface discharge reactor by laser induced fluorescence.

    Science.gov (United States)

    Gao, Liang; Feng, Chun-Lei; Wang, Zhi-Wei; Ding, Hongbin

    2017-05-01

    The current paucity of spatial and temporal characterization of reactive oxygen and nitrogen species (RONS) concentration has been a major hurdle to the advancement and clinical translation of low temperature atmospheric plasmas. In this study, an advanced laser induced fluorescence (LIF) system has been developed to be an effective antibacterial surface discharge reactor for the diagnosis of RONS, where the highest spatial and temporal resolution of the LIF system has been achieved to ∼100 μm scale and ∼20 ns scale, respectively. Measurements on an oxidative OH radical have been carried out as typical RONS for the benchmark of the whole LIF system, where absolute number density calibration has been performed on the basis of the laser Rayleigh scattering method. Requirements for pixel resolved spatial distribution and outer plasma region detection become challenging tasks due to the low RONS concentration (∼ppb level) and strong interference, especially the discharge induced emission and pulsed laser induced stray light. In order to design the highly sensitive LIF system, a self-developed fluorescence telescope, the optimization of high precision synchronization among a tunable pulsed laser, a surface discharge generator, intensified Charge Coupled Device (iCCD) camera, and an oscilloscope have been performed. Moreover, an image BOXCAR approach has been developed to remarkably improve the sensitivity of the whole LIF system by optimizing spatial and temporal gating functions via both hardware and software, which has been integrated into our automatic control and data acquisition system on the LabVIEW platform. In addition, a reciprocation averaging measurement has been applied to verify the accuracy of the whole LIF detecting system, indicating the relative standard deviation of ∼3%.

  5. EDITORIAL: Mercury-free discharges for lighting

    Science.gov (United States)

    Haverlag, M.

    2007-07-01

    This special Cluster of articles in Journal of Physics D: Applied Physics covers the subject of mercury-free discharges that are being investigated by different light source researchers, as an alternative to existing mercury-containing lamps. The main driving force to move away from mercury-containing discharge light sources is connected to the environmentally unfriendly nature of mercury. After inhalation or direct contact, severe mercury exposure can lead to damage to human brain cells, the kidneys, the liver and the nervous system. For this reason, the use of mercury in products is becoming more and more restricted by different governmental bodies. In the lighting industry, however, many products still make use of mercury, for different reasons. The main reason is that mercury-containing products are, in most cases, more efficient than mercury-free products. For a realistic comparison of the environmental impact, the mercury-contamination due to electricity production must be taken into account, which depends on the type of fuel being used. For an average European fuel-mix, the amount of mercury that is released into the environment is around 29 μg kWh-1. This means that a typical 30 W TL lamp during a lifetime of 20,000 hours will release a total of about 20 mg mercury due to electricity production, which exceeds the total mercury dose in the lamp (more and more of which is being recycled) by a factor of 5-10 for a modern TL lamp. This illustrates that, quite apart from other environmental arguments like increased CO2 production, mercury-free alternatives that use more energy can in fact be detrimental for the total mercury pollution over the lifetime of the lamp. For this reason, the lighting industry has concentrated on lowering the mercury content in lamps as long as no efficient alternatives exist. Nevertheless, new initiatives for HID lamps and fluorescent lamps with more or less equal efficiency are underway, and a number of them are described in this

  6. NUMERICAL DESCRIPTION OF THE GROUNDWATER LEVELS CHANGE DUE TO THE RE- AND DISCHARGE OF THE ADJACENT SURFACE WATER BODIES – PROBLEMS AND CASE STUDIES

    Directory of Open Access Journals (Sweden)

    G. Trendafilov

    2012-03-01

    Full Text Available Numerical description of the groundwater levels change due to the re- and discharge of the adjacent surface water bodies – problems and case studies. The water exchange between the surface water bodies (rivers, lakes, seas, dams, etc. and adjacent water-bearing beds is possible if a hydraulic connection between them exists. The change of the levels of the first ones causes corresponding changes of the levels of the aquifers in the surrounding territories and vice versa. In many cases this interaction is the primary mechanism determining the groundwater regime. The aim of the present study is to examine the applicability of the most general possible analytical approach for quantitative description of the phenomena in the case of short-term changes with a significant magnitude (high waves of the level of the river of Maritsa in Plovdiv, Bulgaria. The study is performed through numerical simulations/calculations, with especially composed by the authors for this work computational programs.

  7. Modeling Illumination Conditions on the Moon: Applications to LRO-LAMP

    Science.gov (United States)

    Byron, B. D.; Mazarico, E. M.; Retherford, K. D.; Mandt, K. E.; Greathouse, T.; Gladstone, R.

    2017-12-01

    LRO-LAMP is a UV spectrograph which uses illumination from Lyman-α sky glow along with UV light from bright stars to image the dark, permanently shadowed regions (PSRs) of the lunar surface. Accurate modeling of this UV illumination is essential to creating albedo maps of the lunar surface, which can shed light on lunar regolith processes and help to constrain the distribution of water ice in polar PSRs. In this study, the variation in reflected intensity received by the LAMP detector was modeled for South Pole crater Amundsen using the illumination program IllumNG. Amundsen was chosen for study due to the PSR in its Northern side and its highly illuminated equator-facing slopes on the Southern wall. The model works by tracing a ray from each LAMP detector pixel along its boresight until the point where it intersects the lunar surface, and calculating the percentage of the total source flux visible above the horizon. In this study, the three main illumination sources used are the Sun, Interplanetary Lyman-α sky glow, and bright UV starlight in the On Band (130-155 nm) and Off Band (155-190 nm) wavelength ranges. The model also has the capability to calculate incident flux received at the surface, as well as intensity reflected from the surface and received by the LAMP detector along each boresight. The study found a noticeable variation in received intensity between six month stretches for the year of 2010. Over the period of January through July, about 6% more IPM Lyman-α flux was reflected from the surface of Amundsen than for July through December. For stellar flux in the On Band, a 13% difference in flux was reflected between the six month periods. In comparing the monthly intensity maps created by the model with LAMP measured monthly brightness maps, similar crater features are apparent. Though the model brightness is generally higher than the LAMP brightness, after accounting for albedo ( 0.05 for the South Pole region) the values are in closer agreement

  8. Energy and Emission Characteristics of a Short-Arc Xenon Flash Lamp Under "Saturated" Optical Brightness Conditions

    Science.gov (United States)

    Kamrukov, A. S.; Kireev, S. G.; Kozlov, N. P.; Shashkovskii, S. G.

    2017-09-01

    We present the results of a study of the electrical, energy, and spectral brightness characteristics of an experimental three-electrode high-pressure xenon flash lamp under conditions ensuring close to maximum possible spectral brightness for the xenon emission. We show that under saturated optical brightness conditions (brightness temperature in the visible region of the spectrum 30,000 K), emission of a pulsed discharge in xenon is quite different from the emission from an ideal blackbody: the maximum brightness temperatures are 24,000 K in the short-wavelength UV region and 19,000 K in the near IR range. The relative fraction of UV radiation in the emission spectrum of the lamp is >50%, which lets us consider such lamps as promising broadband sources of radiation with high spectral brightness for many important practical applications.

  9. Comparative Study of Furnace and Flash Lamp Annealed Silicon Thin Films Grown by Plasma Enhanced Chemical Vapor Deposition

    Directory of Open Access Journals (Sweden)

    Maheshwar Shrestha

    2018-03-01

    Full Text Available Low-temperature growth of microcrystalline silicon (mc-Si is attractive for many optoelectronic device applications. This paper reports a detailed comparison of optical properties, microstructure, and morphology of amorphous silicon (a-Si thin films crystallized by furnace annealing and flash lamp annealing (FLA at temperatures below the softening point of glass substrate. The initial a-Si films were grown by plasma enhanced chemical vapor deposition (PECVD. Reflectance measurement indicated characteristic peak in the UV region ~280 nm for the furnace annealed (>550 °C and flash lamp annealed films, which provided evidence of crystallization. The film surface roughness increased with increasing the annealing temperature as well as after the flash lamp annealing. X-ray diffraction (XRD measurement indicated that the as-deposited samples were purely amorphous and after furnace crystallization, the crystallites tended to align in one single direction (202 with uniform size that increased with the annealing temperature. On the other hand, the flash lamp crystalized films had randomly oriented crystallites with different sizes. Raman spectroscopy showed the crystalline volume fraction of 23.5%, 47.3%, and 61.3% for the samples annealed at 550 °C, 650 °C, and with flash lamp, respectively. The flash lamp annealed film was better crystallized with rougher surface compared to furnace annealed ones.

  10. Surface modification of electrospun PVA/chitosan nanofibers by dielectric barrier discharge plasma at atmospheric pressure and studies of their mechanical properties and biocompatibility.

    Science.gov (United States)

    Das, Punamshree; Ojah, Namita; Kandimalla, Raghuram; Mohan, Kiranjyoti; Gogoi, Dolly; Dolui, Swapan Kumar; Choudhury, Arup Jyoti

    2018-03-22

    In this paper, surface of electrospun PVA/Cs nanofibers is modified using dielectric barrier discharge (DBD) plasma and the relationship between the observed mechanical properties and biocompatibility of the nanofibers and plasma-induced surface properties is discussed. Plasma treatment of electrospun PVA/Cs nanofibers is carried out with both inert (argon, Ar) and reactive (oxygen, O 2 ) gases at atmospheric pressure. Incorporation of oxygen-containing polar functional groups on the surface of Ar-plasma treated (PVA/Cs/Ar) and O 2 -plasma treated (PVA/Cs/O 2 ) nanofibers and increase in surface roughness contribute to the improvement of surface wettability and the decrease of contact angle with water of the nanofibers. Both PVA/Cs/Ar and PVA/Cs/O 2 nanofibers show high tensile strength (11.6-15.6%) and Young's modulus (33.8-37.3%) as compared to the untreated one. Experimental results show that in terms of haemolytic activity the PVA/Cs/Ar and PVA/Cs/O 2 nanofibers do not cause structural changes of blood cells and meet the biocompatibility requirements for blood-contacting polymeric materials. MTT cell viability results further reveals improvement in biocompatibility of PVA/Cs nanofibers after Ar and O 2 plasma treatment. The results suggest that DBD plasma treated electrospun PVA/Cs nanofibers have the potential to be used as wound dressing and scaffolds for tissue engineering. Copyright © 2018 Elsevier B.V. All rights reserved.

  11. Surface oxidation of a Melinex 800 PET polymer material modified by an atmospheric dielectric barrier discharge studied using X-ray photoelectron spectroscopy and contact angle measurement

    International Nuclear Information System (INIS)

    Cui Naiyi; Upadhyay, Deepesh J.; Anderson, Colin A.; Meenan, Brian J.; Brown, Norman M.D.

    2007-01-01

    Surface properties of a Melinex 800 PET polymer material modified by an atmospheric-pressure air dielectric barrier discharge (DBD) have been studied using X-ray photoelectron microscopy (XPS) and contact angle measurement. The results show that the material surface treated by the DBD was modified significantly in chemical composition, with the highly oxidised carbon species increasing as the surface processing proceeds. The surface hydrophilicity was dramatically improved after the treatment, with the surface contact angle reduced from 81.8 o for the as-supplied sample to lower than 50 deg. after treatment. Post-treatment recovery effect is found after the treated samples were stored in air for a long period of time, with the ultimate contact angles, as measured, being stabilised in the range 58-69 deg. after the storage, varying with the DBD-treatment power density. A great amount of the C-O type bonding formed during the DBD treatment was found to be converted into the C=O type during post-treatment storage. A possible mechanism for this bond conversion has been suggested

  12. High Power Solid State Retrofit Lamp Thermal Characterization and Modeling

    Directory of Open Access Journals (Sweden)

    J. Jakovenko

    2012-04-01

    Full Text Available Thermal and thermo-mechanical modeling and characterization of solid state lightening (SSL retrofit LED lamp are presented in this paper. Paramount importance is to design SSL lamps for reliability, in which thermal and thermo-mechanical aspects are key points. The main goal is to get a precise 3D thermal lamp model for further thermal optimization. Simulations are performed with ANSYS and CoventorWare software tools to compere different simulation approaches. Simulated thermal distribution has been validated with thermal measurement on a commercial 8W LED lamp. Materials parametric study has been carried out to discover problematic parts for heat transfer from power LEDs to ambient and future solutions are proposed. The objectives are to predict the thermal management by simulation of LED lamp, get more understanding in the effect of lamp shape and used materials in order to design more effective LED lamps and predict light quality, life time and reliability.

  13. NIPPLE DISCHARGE

    Directory of Open Access Journals (Sweden)

    T. N. Bukharova

    2008-01-01

    Full Text Available According to the data available in the literature, as high as 50% of women have benign breast tumors frequently accompanied by nip- ple discharge. Nipple discharge may be serous, bloody, purulent, and colostric. The most common causes are breast abscess, injury, drugs, prolactinoma, intraductal pappiloma, ductal ectasia, intraductal cancer (not more than 10%.

  14. Reator de UV-Ozônio com lâmpada a vapor de mercúrio a alta pressão modificada para tratamento superficial de óxidos transparentes condutivos utilizados em dispositivos poliméricos eletroluminescentes UV-Ozone reactor with modified high pressure mercury vapor lamp for surface treatment of transparent conductive oxides used in electroluminescent polymeric devices

    Directory of Open Access Journals (Sweden)

    Emerson Roberto Santos

    2010-01-01

    Full Text Available An UV-Ozone reactor was developed with an ignition tube extracted into HID mercury lamp used to irradiation on zinc oxide (ZnO and fluorinated tin oxide (FTO films for PLEDs devices. Different exposures times were used. In contact angle measurements revealed better results for ZnO and FTO by 15 and 5 min, respectively. In Diffuse Reflectance Infra-red Fourier Transformed (DRIFT spectroscopy allowed the observation of water, hydrocarbon and carbon dioxide adsorbed on the untreated TCO surfaces. After the UV-Ozone treatment the contaminants were significantly reduced or eliminated and the PLEDs devices decreased threshold voltages in comparison with respectively untreated TCOs.

  15. LED lamp color control system and method

    Science.gov (United States)

    Gaines, James; Clauberg, Bernd; Van Erp, Josephus A.M.

    2013-02-05

    An LED lamp color control system and method including an LED lamp having an LED controller 58; and a plurality of LED channels 60 operably connected to the LED controller 58, each of the plurality of LED channels 60 having a channel switch 62 in series with at least one shunted LED circuit 83, the shunted LED circuit 83 having a shunt switch 68 in parallel with an LED source 80. The LED controller 58 determines whether the LED source 80 is in a feedback controllable range, stores measured optical flux for the LED source 80 when the LED source 80 is in the feedback controllable range, and bypasses storing the measured optical flux when the LED source 80 is not in the feedback controllable range.

  16. UVR: sun, lamps, pigmentation and vitamin D

    DEFF Research Database (Denmark)

    Lerche, C M; Philipsen, P A; Wulf, H C

    2017-01-01

    Exposure to ultraviolet radiation (UVR) has important and significant consequences on human health. Recently, there has been renewed interest in the beneficial effects of UVR. This perspective gives an introduction to the solar spectrum, UV lamps, UV dosimetry, skin pigment and vitamin D. The hea......Exposure to ultraviolet radiation (UVR) has important and significant consequences on human health. Recently, there has been renewed interest in the beneficial effects of UVR. This perspective gives an introduction to the solar spectrum, UV lamps, UV dosimetry, skin pigment and vitamin D....... The health benefits of UVR exposure through vitamin D production or non-vitamin D pathways will be discussed in this themed issue in the following articles....

  17. CALiPER Retail Lamps Study 3

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2014-02-01

    This is a special CALiPER report on LED lamps available through the retail marketplace and targeted toward general consumers. It follows similar reports published in 2011 and 2012 (products purchased in 2010 and 2011), and is intended as a continuation that identifies long-term trends. For this report, products were selected to investigate specific hypotheses, rather than represent a sample of the increasingly large retail LED market.

  18. GPS based surface displacements – a proxy for discharge and sediment transport from the Greenland Ice Sheet

    DEFF Research Database (Denmark)

    Hasholt, Bent; Khan, Shfaqat Abbas; Mikkelsen, Andreas Bech

    2014-01-01

    The elastic respond of the Earth’s surface to mass changes has been measured with Global Positioning System (GPS). Mass loss as accumulated runoff and sediment transport from a 10000 km2 segment of the Greenland Ice Sheet (GrIS) correlated very well (R2=0.83) with GPS measured uplift. Accumulated...

  19. Characterization of electric discharge machining, subsequent etching and shot-peening as a surface treatment for orthopedic implants

    Czech Academy of Sciences Publication Activity Database

    Stráský, J.; Havlíková, Jana; Bačáková, Lucie; Harcuba, P.; Mhaede, M.; Janeček, M.

    2013-01-01

    Roč. 213, Sep 15 (2013), s. 73-78 ISSN 0169-4332 R&D Projects: GA ČR(CZ) GAP107/12/1025 Institutional support: RVO:67985823 Keywords : Ti-6A1-4V * surface treatment * cell proliferation * orthopedics Subject RIV: JG - Metallurgy Impact factor: 2.538, year: 2013

  20. Application of ICP-OES for evaluating energy extraction and production wastewater discharge impacts on surface waters in Western Pennsylvania.

    Science.gov (United States)

    Pancras, Joseph Patrick; Norris, Gary A; Landis, Matthew S; Kovalcik, Kasey D; McGee, John K; Kamal, Ali S

    2015-10-01

    Oil and gas extraction and coal-fired electrical power generating stations produce wastewaters that are treated and discharged to rivers in Western Pennsylvania with public drinking water system (PDWS) intakes. Inductively coupled plasma optical emission spectroscopy (ICP-OES) was used to quantify inorganic species in wastewater and river samples using a method based on EPA Method 200.7 rev4.4. A total of 53 emission lines from 30 elements (Al, As, B, Ba, Ca, Cd, Ce, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Ni, P, Pb, S, Sb, Se, Si, Sn, Sr, Ti, Tl, V, and Zn) were investigated. Samples were prepared by microwave-assisted acid digestion using a mixture of 2% HNO3 and 0.5% HCl. Lower interferences and better detection characteristics resulted in selection of alternative wavelengths for Al, As, Sb, Mg, Mo, and Na. Radial view measurements offered accurate determinations of Al, Ba, K, Li, Na, and Sr in high-brine samples. Spike recovery studies and analyses of reference materials showed 80-105% recoveries for most analytes. This method was used to quantify species in samples with high to low brine concentrations with method detection limits a factor of 2 below the maximum contaminant limit concentrations of national drinking water standards. Elements B, Ca, K, Li, Mg, Na, and Sr were identified as potential tracers for the sources impacting PDWS intakes. Usability of the ICP-OES derived data for factor analytic model applications was also demonstrated. Published by Elsevier B.V.

  1. Ileostomy - discharge

    Science.gov (United States)

    ... dried fruits (such as raisins), mushrooms, chunky relishes, coconut, and some Chinese vegetables. Tips for when no ... ask your doctor Living with your ileostomy Low-fiber diet Small bowel resection - discharge Total colectomy or ...

  2. Investigation of Spectral Characteristics of Pulsed Xenon Lamps for Combined Photochemical Degradation of Organometallic Compounds in Liquid Radioactive Waste

    Directory of Open Access Journals (Sweden)

    M. A. Mishakov

    2017-01-01

    Full Text Available The paper considers the composition of liquid radioactive wastes from the nuclear plants. Using traditional ways to extract organometallic compounds formed, when using the deactivation solutions to clean the surfaces of nuclear plant rooms, are complicated. The paper studies the edge-cutting methods of solving this problem. Its proposal is to use a combined ultraviolet treatment for organometallic compounds degradation based on ethylenediaminetetraacetic acid (EDTA via pulsed xenon lamps. A potential use of the tubular and spherical geometry lamps is examined and advantages, disadvantages and features of these lamps are described. Instead of the pure EDTA the experiments used its disodium salt (Na2-EDTA. The hydrogen peroxide was used as an extra oxidizer. Absorption spectrums of solutions with various Na2-EDTA - hydrogen peroxide ratio were measured. It is found that the absorbance curve maximum is in the shortwave spectrum region (λ < 210 nm. The use of amalgam lamps of monochromatic radiation at wavelength λ = 254 nm will result only in formation of hydroxyl radicals but direct destruction processes of EDTA molecules due to radiation will be rare, and this decreases efficiency of their use.The spectral radiation characteristics of various continuum spectrum pulsed xenon lamps was measured. The experimental data expressed in relative units were compared with the emission spectrum of an absolutely black body. The paper shows that in spherical lamps high brightness temperature can be reached. Thus, in spherical lamps it is possible to obtain a spectrum, which is in maximum correlation with the absorption spectrum of the solutions under study, thereby making them a prospective radiation source for photo-degradation of EDTA compounds. For drawing a final conclusion it is necessary to conduct researches in order to compare Na2-EDTA degradation via tubular and spherical xenon lamps.

  3. Influence of Land Use, Discharge and Impervious Surfaces on the Geochemistry of the Anacostia River, Washington DC.

    Science.gov (United States)

    MacAvoy, S. E.; De Filippis, N.

    2016-12-01

    Challenges facing urban rivers include water stormwater runoff and changing water chemistry, not only from air and water pollution, but also from altered geology with the development of "urban karst" (concrete). The Anacostia River in Washington, D.C. has 75% of its watershed classified as urban or impervious, and is among the 10 most contaminated rivers in the USA. In addition to its relatively well-documented organic contamination problems, we hypothesize that concrete could be substantially altering its geochemistry. Here we report findings from 6 locations along the Anacostia River and its tributaries that indicate both seasonally elevated Na and Cl (becoming brackish, 2000-3000 mg/L Total Dissolved Solids, in a suburban creek), and elevated cations in low flow suburban tributaries. Concentrations of all major cations (Ca, Mg, K, Na) strongly, and positively, covaried (factor scores (FC) >0.88). However Ca/Sr ratios negatively covaried with major cations (FC -0.64). This suggests the weathering of low Sr minerals, such as those in concrete. In urbanized portions of the river, Ca/Sr was >200, which is a concrete weathering indicator in areas with silica mineral bedrock (Anacostia bedrock consists of Precambrian phyllits, sericite, chlorite, quartzite, slate and schist). Mean ± SE Sr was 0.13 ± 0.02 mg/L in the most urban area, but 0.37 ± 0.03 mg/L in the most suburban. This supports the hypothesis that the source of elevated cations in the urban areas is concrete weathering, not bedrock mineral weathering. Inorganic N was not correlated strongly with cations. Mean NO3- was highest at the most suburban site (1.8 ± 0.2 mg/L), but rose above 3 mg/L in some samples at all sites. Elevated NO3- did not appear to vary with season or discharge rate at time of sampling. NH4+ was generally lower than 1 mg/L but spiked to 3.4 mg/L at the most urban site. These data follow patterns expected for "urban stream syndrome". Suburban areas, with their relatively small streams

  4. Heavy metals, salts and organic residues in old solid urban waste landfills and surface waters in their discharge areas: determinants for restoring their impact.

    Science.gov (United States)

    Pastor, J; Hernández, A J

    2012-03-01

    This study was designed to determine the state of polluted soils in the main landfills of the Community of Madrid (central Spain), as part of a continuous assessment of the impacts of urban solid waste (USW) landfills that were capped with a layer of soil 20 years ago. Our analysis of this problem has been highly conditioned by the constant re-use of many of the USW landfills, since they have never been the target of any specific restoration plan. Our periodical analysis of cover soils and soils from discharge areas of the landfills indicates soil pollution has worsened over the years. Here, we examined heavy metal, salts, and organic compounds in soil and surface water samples taken from 15 landfills in the Madrid region. Impacts of the landfill soil covers on nematode and plant diversity were also evaluated. These analyses continue to reveal the presence of heavy metals (Zn, Cu, Cr, Ni, Pb, Cd) in soils, and salts (sulphates, chlorides and nitrates) in soils and surface waters. In addition, non-agricultural organic compounds, mainly aromatic and aliphatic hydrocarbons, often appeared in very high concentrations, and high levels of insecticides such as gamma-HCH (lindane) were also detected in soils. Around 50% of the water samples collected showed chemical demand of oxygen (CDO) values in excess of 150 mg/l. Traces of phenolic compounds were detected in some landfills, some of which exhibited high levels of 2-chlorophenol and pentachlorophenol. All these factors are conditioning both the revegetation of the landfill systems and the remediation of their slopes and terrestrial ecosystems arising in their discharge areas. This work updates the current situation and discusses risks for the health of the ecosystems, humans, domestic animals and wildlife living close to these landfills. Copyright © 2011 Elsevier Ltd. All rights reserved.

  5. The influence of Span-20 surfactant and micro-/nano-Chromium (Cr) Powder Mixed Electrical Discharge Machining (PMEDM) on the surface characteristics of AISI D2 hardened steel

    Science.gov (United States)

    Hosni, N. A. J.; Lajis, M. A.

    2018-04-01

    The application of powder mixed dielectric to improve the efficiency of electrical discharge machining (EDM) has been extensively studied. Therefore, PMEDM have attracted the attention of many researchers since last few decades. Improvement in EDM process has resulted in the use of span-20 surfactant and Cr powder mixed in dielectric fluid, which results in increasing machiniability, better surface quality and faster machining time. However, the study of powder suspension size of surface charateristics in EDM field is still limited. This paper presents the improvement of micro-/nano- Cr powder size on the surface characteristics of the AISI D2 hardened steels in PMEDM. It has found that the reacst layer in PMEDM improved by as high as 41-53 % compared to conventional EDM. Also notably, the combination of added Cr powder and span-20 surfactant reduced the recast layer thickness significantly especially in nano-Cr size. This improvement was great potential adding nano-size Cr powder to dielectric for machining performance.

  6. Fast electric field waveforms and near-surface electric field images of lightning discharges detected on Mt. Aragats in Armenia

    International Nuclear Information System (INIS)

    Chilingarian, A.; Khanikyants, Y.; Kozliner, L.; Soghomonyan, S.

    2016-01-01

    We present the observational data on fast electric waveforms that are detected at 3200 m altitudes above sea level on Mt. Aragats in Armenia during thunderstorms. We analyse the relations of these forms with count rates of particle flux (during Thunderstorm Ground Enhancements -TGEs); to the slow disturbance of the near-surface electrostatic field; and to the lightning location data from the World Wide Lightning Location Network (WWLLN). An observed negative lightning that decreases a negative charge overhead often abruptly terminates TGEs. By analysing the recorded fast electric field waveforms and comparing them with similar classified waveforms reported previously, we could identify the type and polarity of the observed lightnings. (author)

  7. Calibration of a PHREEQC-based geochemical model to predict surface water discharge from an operating uranium mill in the Athabasca Basin

    International Nuclear Information System (INIS)

    Mahoney, J.; Ryan, F.

    2014-01-01

    A PHREEQC based geochemical model has been developed to predict impacts from the McClean Lake Mill discharges through three lakes in the Athabasca Basin, Saskatchewan, Canada. The model is primarily a mixing calculation that uses site specific water balances and water compositions from five sources: 1) two water treatment plants, 2) waters from pit dewatering wells, 3) run-off into the lakes from surface waters, 4) ambient lake compositions, and 5) precipitation (rain and snow) onto the pit lake surface. The model allows for the discharge of these waters into the first lake, which then flows into another nearby lake and finally into a third larger lake. Water losses through evaporation and the impact of subsequent evapoconcentration processes are included in the model. PHREEQC has numerous mass transfer options including mixing, user specified reactions, equilibration with gas and solid phases, and surface complexation. Thus this program is ideally suited to this application. Preparation of such a complicated model is facilitated by an EXCEL Spreadsheet, which converts the water balance into appropriately formatted mixing proportions and to prepare portions of the PHREEQC input file in a format directly useable by PHREEQC. This allows for a high level of flexibility, while reducing transcription errors. For each scenario, the model path involves mixing of the waters in the first lake, followed by evapoconcentration, equilibration of the resulting solution with gas phases, including carbon dioxide and oxygen and with minerals and surfaces. The resultant composition is mixed in the second lake with more surface water, lake water and precipitation, and then re-equilibrated. This water represents the flow into the final lake; further mixing/dilution is accommodated; chemical equilibration may also occur. Because of the numerous steps and processes that define the pathway, each annual step requires approximately 200 lines of input in PHREEQC. Models used in the initial

  8. FASER Rescue Equipment and Mining Lamp Factory

    Energy Technology Data Exchange (ETDEWEB)

    Kubala, L.

    1984-12-01

    The history of the FASER Rescue Equipment and Mining Lamp Factory founded in 1924 is discussed. Plant development from 1924 to 1939 and from 1947 to 1984 is evaluated. The FASER Plant has been subordinated to the EMAG Center for Research and Production of Electrical Engineering and Mine Automation since 1980. Equipment manufactured by the plant is discussed: oxygen respirators, canisters, protective clothing, control systems and measuring instruments used in mine rescue, medical equipment, lighting systems and light bulbs for underground mines. Some problems associated with manufacturing processes are evaluated: manufacturing equipment, manufacturing technologies, quality of rescue equipment, innovation and its economic significance, etc.

  9. Relations between total phosphorus and orthophosphorus concentrations and rainfall, surface-water discharge, and groundwater levels in Big Cypress Seminole Indian Reservation, Florida, 2014–16

    Science.gov (United States)

    McBride, W. Scott; Sifuentes, Dorothy F.

    2018-02-06

    The Seminole Tribe of Florida (the Tribe) is partnering with the U.S. Environmental Protection Agency to develop a numeric phosphorus criterion for the 52,000-acre Big Cypress Seminole Indian Reservation (BCSIR), which is located downgradient of the Everglades Agricultural Area, and of other public and private lands, in southeastern Hendry County and northwestern Broward County in southern Florida. The U.S. Geological Survey (USGS), in cooperation with the Tribe, used water-quality data collected between October 2014 and September 2016 by the Tribe and the South Florida Water Management District (SFWMD), along with data from rainfall gages, surface-water stage and discharge gages, and groundwater monitoring wells, to (1) examine the relations between local hydrology and measured total phosphorus (TP) and orthophosphorus (OP) concentrations and (2) identify explanatory variables for TP concentrations. Of particular concern were conditions when TP exceeded 10 parts per billion (ppb) (0.01 milligram per liter [mg/L]) given that the State of Florida and the Miccosukee Tribe of Indians Alligator Alley Reservation (located downstream of the BCSIR) have adopted a 10-ppb maximum TP criterion for surface waters.From October 2014 to September 2016, the Tribe collected 47–52 samples at each of nine water-quality sites for analysis of TP and OP, except at one site where 28 samples were collected. For all sites sampled, concentrations of TP (as phosphorus [P]) ranged from less than 0.002 mg/L (2 ppb) to a maximum of nearly 0.50 mg/L (500 ppb), whereas concentrations of OP (as P), the reactive form of inorganic phosphorus readily absorbed by plants and (or) abiotically absorbed, ranged from less than 0.003 mg/L (3 ppb) to a maximum of 0.24 mg/L (240 ppb). The median and interquartile ranges of concentrations of TP and OP in the samples collected in 2014–16 by the Tribe were similar to the median and interquartile ranges of concentrations in samples collected by the SFWMD at

  10. Promoting Literacy and Protection with Solar Lamps in Yemen

    Directory of Open Access Journals (Sweden)

    Jerry Farrell

    2014-04-01

    Full Text Available By distributing solar lamps to vulnerable rural women in Yemen, we promoted enrollment in literacy programs, as well as reading among their children. We saw a number of secondary benefits as well: safer households where dangerous kerosene lamps were used less frequently in the evening; a number of livelihood activities - cooking, husbandry, handicrafts - continued safely into evening hours; children found it easier to work on their homework using the solar powered lamps; and children found it easier and safer to walk in dark, rural streets in the evening with the solar lamps slung around their necks.

  11. Sa uurisid ekspressionismi 1960ndatel ja 70ndatel... / Ene Lamp

    Index Scriptorium Estoniae

    Lamp, Ene

    2005-01-01

    2004. a. ilmunud raamatu "Ekspressionism" eest Eesti Kultuurkapitali suure kunstipreemia (100000 kr.) saanud Ene Lamp ekspressionismi tähenduse muutumiset, ekspressionismi rollist eesti kunstis, oma tulevikuplaanidest

  12. Gas phase emitter effect of thulium within ceramic metal halide lamps in dependence on frequency

    Energy Technology Data Exchange (ETDEWEB)

    Ruhrmann, C.; Depta, M.; Bergner, A.; Hoebing, T.; Mentel, J.; Awakowicz, P. [Ruhr University Bochum, Electrical Engineering and Plasma Technology, D-44780 Bochum (Germany); Denissen, C.; Suijker, J. [Philips Lighting, Category Prof. Lamps, PO Box 80020, NL-5600JM Eindhoven (Netherlands)

    2014-02-15

    The gas phase emitter effect within ceramic metal halide (CMH) lamps reduces the effective work function of the electrode material and, therewith, the electrode temperature. An investigation of the gas phase emitter effect of thulium (Tm) within CMH lamps seeded with Tm iodide (TmI3) is carried out. For this purpose, phase resolved images of the arc attachment and measurements of the electrode temperature, Tm atom and ion densities are performed in dependence on operating frequency by pyrometry and optical emission spectroscopy. Additionally, the influence of a sodium iodide (NaI) admixture is studied. The emitter effect is generated by means of a monolayer of Tm atoms on the electrode surface generated by a Tm ion current within the cathodic phase. It overlaps onto the anodic phase at higher frequencies of some hundreds of hertz. The reason is the finite life time of the monolayer, which is determined by the adsorption energy of Tm on the tungsten surface. Due to the low electric field strength in front of the anode and the mass inertia, the emitter ions and atoms remain in front of the anode. They retard the decay of the monolayer and with it the increase of the work function. Moreover, a comparison of a lamp seeded with TmI3 and sodium iodide (NaI) with a lamp seeded only with TmI3 illustrates a slight reduction of the electrode tip temperature caused by a higher Tm saturation vapour pressure and a higher Tm amount within the lamp filling. The influence of Na appears to be quite low. (copyright 2014 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  13. A Novel Heat Sink Design and Prototyping for LED Desk Lamps

    Directory of Open Access Journals (Sweden)

    Li-Ming Chu

    2015-01-01

    Full Text Available Light-emitting diode (LED is a modern lighting device. If the heat dissipating mechanism of LED desk lamp is not well designed, the induced high temperature will cause the reduction of illumination and life time of lamp. Therefore, the heat sink design becomes a key technology for LED lighting device. This study developed a methodology to design and analyze a heat sink for LED cooling. Four different types of heat sinks with fins in longitudinal or transverse directions and with or without vents on the base plate were compared. By using the CFD software FLUENT, heat flux and temperature around the heat sink were analyzed, and the surface temperature distribution was also investigated. The simulation outcomes were compared with experiments results to verify analysis accuracy. The comparisons show only slight differences, and the deviations were less than 4.0%. For cooling LED desk lamp, the design of using 12 vents on both sides of heat sink through natural convection to create the chimney effect was adopted; consequently, the temperature dropped 5°C in average. This design can also reduce the material of heat sink, LED lamp weight, and production cost.

  14. Visible and near-ultraviolet spectra of low-pressure rare-gas microwave discharges

    Science.gov (United States)

    Campbell, J. P.; Spisz, E. W.; Bowman, R. L.

    1971-01-01

    The spectral emission characteristics of three commercial low pressure rare gas discharge lamps wire obtained in the near ultraviolet and visible wavelength range. All three lamps show a definite continuum over the entire wavelength range from 0.185 to 0.6 micrometers. Considerable line emission is superimposed on much of the continuum for wavelengths greater than 0.35 micrometers. These sources were used to make transmittance measurements on quartz samples in the near ultraviolet wavelength range.

  15. High-performance cathode elements for gas-discharge light sources

    Directory of Open Access Journals (Sweden)

    Sevastyanov V. V.

    2009-02-01

    Full Text Available Application of cathode elements of the arc-discharge activator made on the basis of developed material — alloy of iridium and rare-earth metals (of cerium group — has been suggested. The working samples of arc lamps have been produced and tested. The location of metal-alloy cathode has been optimized. The tests demonstrated, that after 4500 hours of work the lighting-up and glowing parameters of such lamps remained stable.

  16. High intensity Discharge lighting; Alumbrado de alta intensidad de descarga

    Energy Technology Data Exchange (ETDEWEB)

    Mendoza E, Ernesto J. [Manufacturera de Reactores, S. A., Mexico, D. F. (Mexico)

    1993-12-31

    This paper gets into contact with some fundamentals in the operation of high discharge intensity lamps. There are useful definitions, as well as the study of the operation of high pressure sodium lamps and of metallic additives operating at less than nominal power. [Espanol] Este trabajo pone al lector en contacto con algunos fundamentos de la operacion de las lamparas de alta intensidad de descarga (HID). Se encuentra con definiciones utiles, asi como el estudio de la operacion de las lamparas de sodio en alta presion y de aditivos metalicos operando a una potencia menor que la nominal.

  17. Contribution of groundwater to the discharge and quality of surface flow: example of the Garonne river upstream of its confluence with the Tarn river

    International Nuclear Information System (INIS)

    Danneville, L.

    1998-01-01

    Very few studies have been made of the contribution of groundwater to the discharge and quality of surface flow at regional scale, such as that of the catchment area of the Garonne river upstream of its confluence with the Tarn river (15.000 km 2 ). Three main types of groundwater reservoir exist in the area: karstic aquifers, alluvial aquifers, and colluvial and local aquifers that are still poorly understood. The contribution from the karstic aquifers to surface flow varies seasonally depending on the nature, hydraulic behaviour and elevation of the karst. Minor exchange occurs between the alluvial aquifers and rivers, mainly during flooding. The Garonne river, which has an average flow of 199 m 3 /s, is mainly replenished by the Salat and Ariege tributaries, regardless of the season. Study of the low-water stage using Maillet's formula has given a good estimate of the groundwater storage of certain tributaries, and the role played by the groundwater is demonstrated by correlation and spectrum analysis of discharge time series. For example, during 1985, the main storage was shown to be in the river basins of Ariege (142 million m 3 ), Salat (111 million m 3 ) and Ger (21 million m 3 ). The Ger, which is the smallest tributary, has the highest specific storage (224 I/m 2 ) and presents an important buffer effect related to numerous karstic springs. The total groundwater storage of the entire recharge area is estimated at 2.1-2.9 billion m 3 for 1993. It is the largest water storage of the basin, greater than the snow cover (371 million m 3 ) and the artificial storage for electric power plants, discharge buffering and irrigation. The groundwater contribution to the total flow of the Garonne river at the Portet gauging station has been estimated at 46-60% of total discharge in 1993 by extrapolating the low-water stage from the residual hydrograph (hydrograph without the influence of dam reservoirs and snow cover), Direct runoff is estimated at 34-48% and the snow

  18. UVR measurement of a UV germicidal lamp.

    Science.gov (United States)

    Chang, Cheng-Ping; Liu, Hung-Hsin; Peng, Chiung-Yu; Shieh, Jeng-Yueh; Lan, Cheng-Hang

    2007-03-01

    Ultraviolet radiation (UVR) exposure is known to cause serious effects such as conjunctivitis and keratitis in eyes and erythema in skin. The exposure assessment of UVR has not been well established and developed in workplaces due to the lack of suitable UV detecting instruments. Therefore, UV monitoring and measuring procedures were investigated and developed with commercial spectroradiometry devices described in this paper. The UVR irradiance integrated with a biological effective parameter (S lambda) represents the impacts on human skin and eyes as UV effective irradiance. The spectral weighting function derived from the American Conference of Governmental Industrial Hygienists was applied and evaluated to indicate the degree of harmfulness of UVR as a function of wavelength. A portable UV germicidal lamp with short and long wavelengths (254 nm and 365 nm) served as the UVR emission source. The UVR photon count similar to the perceived brightness of a source, irradiance, and effective irradiance (E eff) of the germicidal lamp were measured and analyzed, then the permissible exposure times (T max) were derived for UVR exposure assessment. This monitoring provided a comprehensive approach to detecting UVR magnitude, evaluated the performance of the approach, and quantified the effective exposure based on measured data. From this study, the methodology of UV measurement was established and could be applied to further UVR exposure assessment in the workplace.

  19. [Near infrared light irradiator using halogen lamp].

    Science.gov (United States)

    Ide, Yasuo

    2012-07-01

    The practical electric light bulb was invented by Thomas Alva Edison in 1879. Halogen lamp is the toughest and brightest electric light bulb. With light filter, it is used as a source of near infrared light. Super Lizer and Alphabeam are made as near infrared light irradiator using halogen lamp. The light emmited by Super Lizer is linear polarized near infrared light. The wave length is from 600 to 1,600 nm and strongest at about 1,000 nm. Concerning Super Lizer, there is evidence of analgesic effects and normalization of the sympathetic nervous system. Super Lizer has four types of probes. SG type is used for stellate ganglion irradiation. B type is used for narrow area irradiation. C and D types are for broad area irradiation. The output of Alphabeam is not polarized. The wave length is from 700 to 1,600 nm and the strongest length is about 1,000nm. Standard attachment is used for spot irradiation. Small attachment is used for stellate ganglion irradiation. Wide attachment is used for broad area irradiation. The effects of Alphabeam are thought to be similar to that of Super Lizer.

  20. LED lamps in shipboard lighting systems: Aspects of electromagnetic compatibility

    Directory of Open Access Journals (Sweden)

    Beley V. F.

    2016-12-01

    Full Text Available Trends in the development of different types of light sources and their energy characteristics have been described in the paper. Analysis of regulatory documents has been given. The results of experimental studies of a number of modern LED lamps have been described. Investigation has been made for a number of LED lamps produced by Philips, Xavax and Melitec. The experimental data have been obtained with the complex of devices: the dual-channel oscilloscope (GDS-71042, the power quality analyzer (Fluke-434 and the multi-function device EcoLight-01 (light-, pulse- and luminance meter. It has been shown that operation of LED lamps is characterized by emission of higher current harmonics and reactive power consumption, which depends on the type and design of the lamp driver. It has been found that the value of luminance created by LED lamps in case of acceptable (for ships prolonged deviation of voltage (–10 % is reduced by 3 %; in case of permissible short-term voltage deviation (–20 % luminance is reduced by 7 %. For incandescent lamps this indicator is characterized by a decrease in luminance by 40 % and 60 %, respectively. Despite the low sensitivity to voltage changes (in comparison with other types of lamps, the operation of LED lamps is also associated with the appearance of flicker. Absence of limitations for fluctuations of the light flux in shipboard lighting systems and imperfection of methods for determining the flicker make it difficult to ensure electromagnetic compatibility of LED lamps. Therefore due to reliability, environmental friendliness, energy efficiency and lumen maintenance LED lamps have prospects for introduction into shipboard lighting systems. However, to ensure electromagnetic compatibility of LED lighting systems it is necessary to conduct a detailed study of energy characteristics of LED lamps and to develop appropriate regulatory requirements and technical solutions.

  1. Esophagectomy - discharge

    Science.gov (United States)

    ... 000241.htm Esophagectomy - discharge To use the sharing features on this page, please enable JavaScript. You had ... up or down stairs, or ride in a car. Be sure to rest after being active. If it hurts when ... In the bathroom , install safety bars to help you get in and out ...

  2. Mastectomy - discharge

    Science.gov (United States)

    ... had breast reconstruction surgery with implants or natural tissue . What to Expect at Home Full recovery may take ... lump removal Breast reconstruction - implants Breast reconstruction - natural ... breast surgery - discharge Mastectomy and breast reconstruction - what to ask your doctor Wet-to-dry dressing ...

  3. 49 CFR 393.23 - Power supply for lamps.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 5 2010-10-01 2010-10-01 false Power supply for lamps. 393.23 Section 393.23 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL MOTOR CARRIER SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION FEDERAL MOTOR CARRIER SAFETY REGULATIONS PARTS AND ACCESSORIES NECESSARY FOR SAFE OPERATION Lamps,...

  4. Thermal design for the high-power LED lamp

    International Nuclear Information System (INIS)

    Tian Xiaogai; Chen Wei; Zhang Jiyong

    2011-01-01

    This paper summarizes different kinds of heat sinks on the market for high power LED lamps. Analysis is made on the thermal model of LED, PCB and heat sink separately with a simplified mode provided. Two examples of simulation are illustrated as a demonstration for the thermal simulation as guidance for LED lamp design. (semiconductor devices)

  5. Evaluation and improvement of LAMP assays for detection of

    African Journals Online (AJOL)

    The existing LAMP assays were modified via adding 1% tetramethylene sulfoxide and 5% dimethyl sulfoxide as well as optimizing reaction temperature. Results: The detection limit of the modified LAMP assays was 0.1-1 pg per reaction, equivalent to 25-250 cfu per reaction, the non-specific amplification can completely be ...

  6. Application of loop-mediated isothermal amplification (LAMP) of the ...

    African Journals Online (AJOL)

    RIME-LAMP helps increase the probability of detecting the positive cases of camel Trypanosomiasis and it was found to be one useful and alternative molecular diagnostic tool for the detection of T. evansi infections. Key words: Sudan, loop-mediated isothermal amplification (LAMP) - random insertion mobile element (RIME ...

  7. Luminous flux and colour maintenance investigation of integrated LED lamps

    DEFF Research Database (Denmark)

    Corell, Dennis Dan; Thorseth, Anders; Dam-Hansen, Carsten

    2014-01-01

    This article will present an investigation of the luminous flux and colour maintenance of white LED based retrofit lamps. The study includes 23 different types of integrated LED lamps, covering 18 directional and 5 non-directional. Luminous flux and colour data for operation up to 20000 h has been...

  8. Design of LED lamps | Ashryatov | Journal of Fundamental and ...

    African Journals Online (AJOL)

    The variant of the lighting system energy efficiency increase with luminaires and linear fluorescent lamps is considered. In the proposed variant, the fluorescent lamps and start regulating devices are replaced with linear LED modules. In order to reduce the glossiness of a luminaire, the LED modules must be covered with ...

  9. Thermal simulation and validation of 8W LED lamp

    NARCIS (Netherlands)

    Jakovenko, J.; Werkhoven, R.J.; Formánek, J.; Kunen, J.M.G.; Bolt, P.J.; Kulha, P.

    2011-01-01

    This work deals with thermal simulation and characterization of solid state lightening (SSL) LED Lamp in order to get precise 3D thermal models for further lamp thermal optimization. Simulations are performed with ANSYS-CFX and CoventorWare software tools. The simulated thermal distribution has been

  10. High power solid state retrofit lamp thermal characterization and modeling

    NARCIS (Netherlands)

    Jakovenko, J.; Formánek, J.; Vladimír, J.; Husák, M.; Werkhoven, R.J.

    2012-01-01

    Thermal and thermo-mechanical modeling and characterization of solid state lightening (SSL) retrofit LED Lamp are presented in this paper. Paramount Importance is to design SSL lamps for reliability, in which thermal and thermo-mechanical aspects are key points. The main goal is to get a precise 3D

  11. Structurally Integrated Coatings for Wear and Corrosion (SICWC): Arc Lamp, InfraRed (IR) Thermal Processing

    Energy Technology Data Exchange (ETDEWEB)

    Mackiewicz-Ludtka, G.; Sebright, J. [Caterpillar Corp.

    2007-12-15

    The primary goal of this Cooperative Research and Development Agreement (CRADA) betwe1311 UT-Battelle (Contractor) and Caterpillar Inc. (Participant) was to develop the plasma arc lamp (PAL), infrared (IR) thermal processing technology 1.) to enhance surface coating performance by improving the interfacial bond strength between selected coatings and substrates; and 2.) to extend this technology base for transitioning of the arc lamp processing to the industrial Participant. Completion of the following three key technical tasks (described below) was necessary in order to accomplish this goal. First, thermophysical property data sets were successfully determined for composite coatings applied to 1010 steel substrates, with a more limited data set successfully measured for free-standing coatings. These data are necessary for the computer modeling simulations and parametric studies to; A.) simulate PAL IR processing, facilitating the development of the initial processing parameters; and B.) help develop a better understanding of the basic PAL IR fusing process fundamentals, including predicting the influence of melt pool stirring and heat tnmsfar characteristics introduced during plasma arc lamp infrared (IR) processing; Second, a methodology and a set of procedures were successfully developed and the plasma arc lamp (PAL) power profiles were successfully mapped as a function of PAL power level for the ORNL PAL. The latter data also are necessary input for the computer model to accurately simulate PAL processing during process modeling simulations, and to facilitate a better understand of the fusing process fundamentals. Third, several computer modeling codes have been evaluated as to their capabilities and accuracy in being able to capture and simulate convective mixing that may occur during PAL thermal processing. The results from these evaluation efforts are summarized in this report. The intention of this project was to extend the technology base and provide for

  12. Uranium vapor generator: pulsed hollow cathode lamp

    International Nuclear Information System (INIS)

    Carleer, M.; Gagne, J.; Leblanc, B.; Demers, Y.; Mongeau, B.

    1979-01-01

    The production of uranium vapors has been studied in the 5 L 0 6 ground state using a pulsed hollow cathode lamp. The evolution of the 238 U ( 5 L 0 6 ) concentration with time has been studied with Xe and Ar as buffer gases. A density of 2.7 x 10 13 atoms cm -3 was obtained with Xe as a buffer gas. In addition, those measurements, obtained from the absorption of a laser beam tuned to the 5758.143 A ( 5 L 0 6 -17,361 7 L 6 ) transition, allowed the determination of the transition probability A=2.1 x 10 5 sec -1 and of the branching ratio BR=0.08 for this transition

  13. Radiological discharges

    International Nuclear Information System (INIS)

    Woodliffe, J.

    1990-01-01

    Current practice of North Sea States on the discharge and disposal of liquid radioactive wastes to the North Sea are based on the declaration issued at the Second International Conference on the Protection of the North Sea, known as the London Declaration. This has three main points the first of which emphasises the application of the Best Available Technology to protect the North Sea, the second provides a framework on which future controls on radioactive discharges should be based. The third identifies two parts of the framework; to take into account the recommendations of international organizations and that any repositories of radioactive waste which are built should not pollute the North Sea. This chapter looks at how the concensus based on the London Declaration is working, gauges the progress made in the implementation of the policy goal, identifies existing and future areas for concern and proposes ways of strengthening the control of radioactive discharges. The emphasis is on the United Kingdom practice and regulations for liquid wastes, most of which comes from the Sellafield Reprocessing Plant. (author)

  14. EFFECTS OF LASER RADIATION ON MATTER. LASER PLASMA: Dynamics of a plasma formed by a surface optical-discharge in a metal vapour interacting with a cw CO2 laser beam

    Science.gov (United States)

    Zaikin, A. E.; Levin, A. V.; Petrov, A. L.

    1995-02-01

    A surface optical-discharge plasma was formed in a metal vapour under normal conditions by steady-state irradiation with a cw CO2 laser delivering radiation of moderate (2-4.5 MW cm-2) intensity. This plasma strongly screened the irradiated surface. Under the selected experimental conditions the optical discharge was not a continuous (steady-state) process. The plasma cloud was displaced along the beam out of the waist to a region where the laser radiation intensity was almost an order of magnitude less than the threshold for excitation of the optical-discharge plasma in the vapour. A strong screening of the metal surface, which could even completely stop evaporation of the metal, was observed. Self-oscillations of the optical-discharge plasma were observed for the first time in a vapour interacting with cw CO2 radiation: this was attributed to screening of the target surface. Within one period of the self-oscillations there were additional hf plasma pulsations which led to stratification of the plasma cloud. The results obtained were interpreted.

  15. Heavy metals, salts and organic residues in solid urban waste landfills and surface waters in their discharge areas: determinants for restoring their discharge areas: determinants for restoring their impact

    International Nuclear Information System (INIS)

    Hernandez, A. J.; Pastor, J.

    2009-01-01

    This report describes a continuous assessment of the impact of solid urban waste (SUW) landfills in the central Iberian Peninsula that were sealed with a layer of soil 20 years ago. cover soils and soils from discharge areas have been periodically analysed. Soil concentrations of salts and heavy metals affect the biotic components of these ecosystems. (Author)

  16. Surface discharge phenomena of solid insulators under negative impulse voltage in atmospheric air. Taikichu fu impulse den'atsu inkaji no kotai yudentai no enmen hoden gensho

    Energy Technology Data Exchange (ETDEWEB)

    Shimazaki, T.; Hayashi, T.; Manabe, Y. (Fukuoka Univ., Fukuoka (Japan). Faculty of Engineering)

    1991-09-01

    In the case where PET film thickness is varied as a characteristic of creeping discharge in such a electrode arrangement that a rear electrode exists over the whole surface of an insulator, a relation was derived among a creeping distance d'' when negative impulse voltage was applied, a creeping flashover voltage V{sub 50} and a 50% creeping corona onset voltage V{sub C50}. As a result, the V{sub 50}-d characteristic is shown by approximately two straight lines with a certain creeping distance dc'' determined by t'' as a boundary. When a range of d'' being 0.4 cm-dc is called the region C' and a range of dc-10 cm the region A', the V{sub 50} takes the same expression as in the case of acrylic plate in the region C', but in the region A', takes a different expression from that for the acrylic plate. The creeping flashover process in the region A' is approximately identical with that for the acrylic plate. However, the negative streamer's progress distance shortens with an increase in the intrinsic capacity, so does the generation interval. The creeping flashover process in the region C' is the same as for the acrylic plate. 9 refs., 16 figs.

  17. DC-pulse atmospheric-pressure plasma jet and dielectric barrier discharge surface treatments on fluorine-doped tin oxide for perovskite solar cell application

    Science.gov (United States)

    Tsai, Jui-Hsuan; Cheng, I.-Chun; Hsu, Cheng-Che; Chen, Jian-Zhang

    2018-01-01

    Nitrogen DC-pulse atmospheric-pressure plasma jet (APPJ) and nitrogen dielectric barrier discharge (DBD) were applied to pre-treat fluorine-doped tin oxide (FTO) glass substrates for perovskite solar cells (PSCs). Nitrogen DC-pulse APPJ treatment (substrate temperature: ~400 °C) for 10 s can effectively increase the wettability, whereas nitrogen DBD treatment (maximum substrate temperature: ~140 °C) achieved limited improvement in wettability even with increased treatment time of 60 s. XPS results indicate that 10 s APPJ, 60 s DBD, and 15 min UV-ozone treatment of FTO glass substrates can decontaminate the surface. A PSC fabricated on APPJ-treated FTO showed the highest power conversion efficiency (PCE) of 14.90%; by contrast, a PSC with nitrogen DBD-treated FTO shows slightly lower PCE of 12.57% which was comparable to that of a PSC on FTO treated by a 15 min UV-ozone process. Both nitrogen DC-pulse APPJ and nitrogen DBD can decontaminate FTO substrates and can be applied for the substrate cleaning step of PSC.

  18. Enhanced removal of humic acid from micro-polluted source water in a surface discharge plasma system coupled with activated carbon.

    Science.gov (United States)

    Wang, Tiecheng; Li, Yujuan; Qu, Guangzhou; Sun, Qiuhong; Liang, Dongli; Hu, Shibin; Zhu, Lingyan

    2017-09-01

    Surface discharge plasma (SDP) combined with activated carbon (AC) was employed to eliminate dissolved organic matter from micro-polluted source water, with humic acid (HA) as the model pollutant. Synergistic effect on HA removal was observed in the SDP-AC system; HA removal efficiency reached 60.9% within 5-min treatment in the SDP-AC system with 5.0 g AC addition, whereas 16.7 and 17.4% of HA were removed in sole SDP system and AC adsorption, respectively. Scanning electron microscope and Boehm titration analysis showed that chemical reactions between active species and functional groups of AC occurred. The existence of isopropanol or benzoquinone exhibited inhibitive effects on HA removal in the SDP system, while these inhibitive effects were weakened in the SDP-AC system. The influences of AC on ozone equivalent concentration and H 2 O 2 concentration were evaluated, and there were approximately 39 and 20% decline in ozone equivalent concentration and H 2 O 2 concentration within 6-min treatment in the SDP-AC system, respectively, compared with those in the sole SDP system. Dissolved organic carbon, specific ultraviolet absorbance, and UV absorption ratios analysis demonstrated that the SDP treatment destroyed the chromophoric groups, double bonds, and aromatic structure of HA molecules, and these destructive actions were strengthened by AC.

  19. Discharge plasmas as EUV Sources for Future Micro Lithography

    Science.gov (United States)

    Kruecken, Thomas

    2007-08-01

    Future extreme ultraviolet (EUV) lithography will require very high radiation intensities in a narrow wavelength range around 13.5 nm, which is most efficiently emitted as line radiation by highly ionized heavy particles. Currently the most intense EUV sources are based on xenon or tin gas discharges. After having investigated the limits of a hollow cathode triggered xenon pinch discharge Philips Extreme UV favors a laser triggered tin vacuum spark discharge. Plasma and radiation properties of these highly transient discharges will be compared. Besides simple MHD-models the ADAS software package has been used to generate important atomic and spectral data of the relevant ion stages. To compute excitation and radiation properties, collisional radiative equilibria of individual ion stages are computed. For many lines opacity effects cannot be neglected. In the xenon discharges the optical depths allow for a treatment based on escape factors. Due to the rapid change of plasma parameters the abundancies of the different ionization stages must be computed dynamically. This requires effective ionization and recombination rates, which can also be supplied by ADAS. Due to very steep gradients (up to a couple orders of magnitude per mm) the plasma of tin vacuum spark discharges is very complicated. Therefore we shall describe here only some technological aspects of our tin EUV lamp: The electrode system consists of two rotating which are pulled through baths of molten tin such that a tin film remains on their surfaces. With a laser pulse some tin is ablated from one of the wheels and travels rapidly through vacuum towards the other rotating wheel. When the tin plasma reaches the other electrodes it ignites and the high current phase starts, i.e. the capacitor bank is unloaded, the plasma is pinched and EUV is radiated. Besides the good spectral properties of tin this concept has some other advantages: Erosion of electrodes is no severe problem as the tin film is

  20. Application Summary Report 22: LED MR16 Lamps

    Energy Technology Data Exchange (ETDEWEB)

    Royer, Michael P.

    2014-07-23

    This report analyzes the independently tested photometric performance of 27 LED MR16 lamps. It describes initial performance based on light output, efficacy, distribution, color quality, electrical characteristics, and form factor, with comparisons to a selection of benchmark halogen MR16s and ENERGY STAR qualification thresholds. Three types of products were targeted. First, CALiPER sought 3000 K lamps with the highest rated lumen output (i.e., at least 500 lm) or a claim of equivalency to a 50 W halogen MR16 or higher. The test results indicate that while the initial performance of LED MR16s has improved across the board, market-available products still do not produce the lumen output and center beam intensity of typical 50 W halogen MR16 lamps. In fact, most of the 18 lamps in this category had lower lumen output and center beam intensity than a typical 35 W halogen MR16 lamp. Second, CALiPER sought lamps with a CRI of 90 or greater. Only four manufacturers were identified with a product in this category. CALiPER testing confirmed the performance of these lamps, which are a good option for applications where high color fidelity is needed. A vast majority of the LED MR16 lamps have a CRI in the low 80s; this is generally acceptable for ambient lighting, but may not always be acceptable for focal lighting. For typical LED packages, there is a fundamental tradeoff between CRI and efficacy, but the lamps in the high-CRI group in this report still offer comparable performance to the rest of the Series 22 products in other performance areas. Finally, CALiPER sought lamps with a narrow distribution, denoted as a beam angle less than 15°. Five such lamps were purchased. Notably, no lamp was identified as having high lumen output (500 lumens or greater), high CRI (90 or greater), a narrow distribution (15° or less), and an efficacy greater than 60 lm/W. This would be an important achievement for LED MR16s especially if output could reach approximately 700 800 lumens

  1. Microplasma light tiles: thin sheet lamps for general illumination

    International Nuclear Information System (INIS)

    Eden, J G; Park, S-J; Herring, C M; Bulson, J M

    2011-01-01

    Flat, thin and lightweight lamps providing spatially uniform and dimmable illumination from active areas as large as 400 cm 2 are being developed for general illumination and specialty applications. Comprising an array of low-temperature, nonequilibrium microplasmas driven by a dielectric barrier structure and operating at pressures of typically 400-700 Torr, these lamps have a packaged thickness -2 with a luminous efficacy approaching 30 lm W -1 . Third generation lamps, presently in limited production, offer a correlated colour temperature in the 3000-4100 K interval and a colour rendering index of 80. Current lamps employ Xe 2 (λ ∼ 172 nm) as the primary emitter photoexciting a mixture of phosphors, and the pressure dependence of the wavelength-integrated fluorescence from the electronically excited dimer has been investigated with a vacuum ultraviolet spectrometer. In contrast to other promising lighting technologies, the decline in luminous efficacy of microplasma lamps with increasing power delivered to the lamp is small. For a 6 x 6 inch 2 (∼225 cm 2 ) lamp, efficacy falls -2 to > 10 000 cd m -2 .

  2. THE APPARATUS FOR ALIGNMENT OF THE PHOTOMETRIC LAMP FILAMENT

    Directory of Open Access Journals (Sweden)

    V. A. Dlugunovich

    2015-01-01

    Full Text Available During photometric measurements involving the use of photometric lamps it is necessary that the filament of lamp takes a strictly predetermined position with respect to the photodetector and the optical axis of the photometric setup. The errors in positioning of alignment filament with respect to the optical axis of the measuring system lead to increase the uncertainty of measurement of the photometric characteristics of the light sources. A typical method for alignment of filament of photometric lamps is based on the use a diopter tubes (telescopes. Using this method, the mounting of filament to the required position is carried out by successive approximations, which requires special concentration and a lot of time. The aim of this work is to develop an apparatus for alignment which allows simultaneous alignment of the filament of lamps in two mutually perpendicular planes. The method and apparatus for alignment of the photometric lamp filament during measurements of the photometric characteristics of light sources based on two digital video cameras is described in this paper. The apparatus allows to simultaneously displaying the image of lamps filament on the computer screen in two mutually perpendicular planes. The apparatus eliminates a large number of functional units requiring elementwise alignment and reduces the time required to carry out the alignment. The apparatus also provides the imaging of lamps filament with opaque coated on the bulb. The apparatus is used at the National standard of light intensity and illuminance units of the Republic of Belarus. 

  3. Non-crosslinking gold nanoprobe-LAMP for simple, colorimetric, and specific detection of Salmonella typhi

    Energy Technology Data Exchange (ETDEWEB)

    Bozorgmehr, Ali; Yazdanparast, Razieh, E-mail: ryazdan@ut.ac.ir [University of Tehran, Institute of Biochemistry and Biophysics (Iran, Islamic Republic of); Mollasalehi, Hamidreza [Shahid Beheshti University, Protein Research Center (Iran, Islamic Republic of)

    2016-12-15

    In this study, we developed a non-crosslinking gold nanoprobe loop-mediated isothermal amplification (LAMP) method for nanodiagnosis of bacterial typhoid fever source, Salmonella typhi. Therefore, a unique region in the S. typhi genomic DNA was targeted for LAMP amplification using a specific set of four precisely designed primers. Also, for specific colorimetric visualization of the amplicons, a thiolated oligonucleotide probe, complementary to the single-stranded loop region of the amplicons between F2 and F1C segments, was designed. The probe was bound to the surface of gold nanoparticles via covalent bonds. Increasing the salt concentration in the detection reaction medium led to aggregation of nanoprobes in the blank and the negative vessels in a time-dependent form. That was followed by a change in the surface plasmon resonance (SPR) leading to blue/black color that was observable by the naked eyes after about 5 min. Meanwhile, the original pink/red color was retained in the positive sample due to the large interparticle spaces and the stability against the ionic strength elevation which persisted for about 30 min. The whole process of DNA extraction, amplification, and detection took less than 2 h with a sensitivity of 20 CFU/ml. The developed gold nanoprobe-LAMP could serve as a simple, rapid, and cost-effective method for nanodiagnosis of S. typhi in point-of-need applications.

  4. Discharge Dialogue

    DEFF Research Database (Denmark)

    Horsbøl, Anders

    2012-01-01

    less attention has been given to medical patients, who are often elderly and suffer from multiple diseases. This paper addresses the latter issue with a case study of a local initiative to improve transition from hospital to home (care) for medical patients at a Danish hospital, in which a discharge......For several years, efforts have been made to strengthen collaboration between health professionals with different specializations and to improve patient transition from hospital to home (care). In the Danish health care system, these efforts have concentrated on cancer and heart diseases, whereas...

  5. LED lamp or bulb with remote phosphor and diffuser configuration with enhanced scattering properties

    Science.gov (United States)

    Tong, Tao; Le Toquin, Ronan; Keller, Bernd; Tarsa, Eric; Youmans, Mark; Lowes, Theodore; Medendorp, Jr., Nicholas W; Van De Ven, Antony; Negley, Gerald

    2014-11-11

    An LED lamp or bulb is disclosed that comprises a light source, a heat sink structure and an optical cavity. The optical cavity comprises a phosphor carrier having a conversions material and arranged over an opening to the cavity. The phosphor carrier comprises a thermally conductive transparent material and is thermally coupled to the heat sink structure. An LED based light source is mounted in the optical cavity remote to the phosphor carrier with light from the light source passing through the phosphor carrier. A diffuser dome is included that is mounted over the optical cavity, with light from the optical cavity passing through the diffuser dome. The properties of the diffuser, such as geometry, scattering properties of the scattering layer, surface roughness or smoothness, and spatial distribution of the scattering layer properties may be used to control various lamp properties such as color uniformity and light intensity distribution as a function of viewing angle.

  6. Treatability study for removal of leachable mercury in crushed fluorescent lamps

    International Nuclear Information System (INIS)

    Bostick, W.D.; Beck, D.E.; Bowser, K.T.

    1996-02-01

    Nonserviceable fluorescent lamps removed from radiological control areas at the Oak Ridge Department of Energy facilities have been crushed and are currently managed as mixed waste (hazardous and radiologically contaminated). We present proposed treatment flowsheets and supporting treatability study data for conditioning this solid waste residue so that it can qualify for disposal in a sanitary landfill. Mercury in spent fluorescent lamps occurs primarily as condensate on high-surface-area phosphor material. It can be solubilized with excess oxidants (e.g., hypochlorite solution) and stabilized by complexation with halide ions. Soluble mercury in dechlorinated saline solution is effectively removed by cementation with zero-valent iron in the form of steel wool. In packed column dynamic flow testing, soluble mercury was reduced to mercury metal and insoluble calomel, loading > 1.2 g of mercury per grain of steel wool before an appreciable breakthrough of soluble mercury in the effluent

  7. Treatability study for removal of leachable mercury in crushed fluorescent lamps

    Energy Technology Data Exchange (ETDEWEB)

    Bostick, W.D.; Beck, D.E.; Bowser, K.T. [and others

    1996-02-01

    Nonserviceable fluorescent lamps removed from radiological control areas at the Oak Ridge Department of Energy facilities have been crushed and are currently managed as mixed waste (hazardous and radiologically contaminated). We present proposed treatment flowsheets and supporting treatability study data for conditioning this solid waste residue so that it can qualify for disposal in a sanitary landfill. Mercury in spent fluorescent lamps occurs primarily as condensate on high-surface-area phosphor material. It can be solubilized with excess oxidants (e.g., hypochlorite solution) and stabilized by complexation with halide ions. Soluble mercury in dechlorinated saline solution is effectively removed by cementation with zero-valent iron in the form of steel wool. In packed column dynamic flow testing, soluble mercury was reduced to mercury metal and insoluble calomel, loading > 1.2 g of mercury per grain of steel wool before an appreciable breakthrough of soluble mercury in the effluent.

  8. Research on Cylindrical Surface Wave Plasma Fluorescent Lamps

    Directory of Open Access Journals (Sweden)

    Kun WANG

    2013-07-01

    Full Text Available This paper presents an application of the well known SPWM technique on a voltage stabilizer, using a microcontroller. The stabilizer is AC/DC/AC type. So, the system rectifies the input AC voltage to a suitable DC level and the intelligent control of an embedded microcontroller regulates the pulse width of the output voltage in order to produce through a filter a perfect sinusoidal AC voltage. The control program on the microcontroller has the ability to change the FET transistor firing in order to compensate any input voltage variation. The applied software using the microcontroller’s interrupts managed to achieve concurrency on the running program.

  9. Multiple-barrier disinfection by chlorination and UV irradiation for desalinated drinking waters: chlorine photolysis and accelerated lamp-sleeve fouling effects.

    Science.gov (United States)

    Wait, Isaac W

    2008-11-01

    Experiments were conducted to quantify interaction effects between UV irradiation and chlorination for desalinated drinking water. The rate of chlorine photolysis in desalinated water was characterized using a low-pressure UV lamp and chlorine doses typical of drinking water treatment and was found to be lower than reported photolysis rates for treated surface water. Results indicate that, for most desalinated water applications, reduction in free chlorine is likely to be limited, but, depending on the UV dose used, not necessarily negligible. Investigation of the potential for reactor lamp-sleeve fouling included mineral speciation and solubility modeling and showed that chlorination of desalinated water before UV disinfection may increase lamp-sleeve fouling, particularly for point-of-use reactors. UV irradiation before chlorination may minimize fouling. Overall results point to the variable nature of UV lamp-sleeve fouling and chlorine photolysis and an intrinsic dependence on local water chemistry conditions.

  10. Exposure reductions associated with introduction of solar lamps to kerosene lamp-using households in Busia County, Kenya.

    Science.gov (United States)

    Lam, N L; Muhwezi, G; Isabirye, F; Harrison, K; Ruiz-Mercado, I; Amukoye, E; Mokaya, T; Wambua, M; Bates, M N

    2018-03-01

    Solar lamps are a clean and potentially cost-effective alternative to polluting kerosene lamps used by millions of families in developing countries. By how much solar lamps actually reduce exposure to pollutants, however, has not been examined. Twenty households using mainly kerosene for lighting were enrolled through a secondary school in Busia County, Kenya. Personal PM 2.5 and CO concentrations were measured on a school pupil and an adult in each household, before and after provision of 3 solar lamps. PM 2.5 concentrations were measured in main living areas, pupils' bedrooms, and kitchens. Usage sensors measured use of kerosene and solar lighting devices. Ninety percent of baseline kerosene lamp use was displaced at 1-month follow-up, corresponding to average PM 2.5 reductions of 61% and 79% in main living areas and pupils' bedrooms, respectively. Average 48-h exposure to PM 2.5 fell from 210 to 104 μg/m 3 (-50%) among adults, and from 132 to 35 μg/m 3 (-73%) among pupils. Solar lamps displaced most kerosene lamp use in at least the short term. If sustained, this could mitigate health impacts of household air pollution in some contexts. Achieving safe levels of exposure for all family members would likely require also addressing use of solid-fuel stoves. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  11. Determination of non-gaseous and gaseous mercury fractions in unused fluorescent lamps: a study of different lamp types.

    Science.gov (United States)

    Figi, Renato; Nagel, Oliver; Schreiner, Claudia; Hagendorfer, Harald

    2015-03-01

    Since incandescent light bulbs have been phased out in the European Union from 2009, the use of fluorescent lamps has drastically increased as a reliable, more energy-efficient and cost-effective alternative. State-of-the-art fluorescent lamps are dependent on mercury/mercury alloys, posing a risk for the consumer and the environment, and appropriate waste management is challenging. Consequently analytical methods to determine possible mercury species (non-gaseous/gaseous) in these lamps are of need. Here, a straightforward and wet-chemistry-based analytical strategy for the determination of gaseous and non-gaseous mercury in commercially available fluorescent lamps is presented. It can be adapted in any analytical laboratory, without or with only minimum modifications of already installed equipment. The analytical figures of merit, as well as application of the method to a series of commercially available fluorescent lamps, are presented. Out of 14 analysed and commercially available lamp types, results from this study indicate that only one contains a slightly higher amount of mercury than set by the legislative force. In all new lamps the amount of gaseous mercury is negligible compared with the non-gaseous fraction (88%-99% of total mercury). © The Author(s) 2015.

  12. PREFACE: Diagnostics for electrical discharge light sources: pushing the limits Diagnostics for electrical discharge light sources: pushing the limits

    Science.gov (United States)

    Zissis, Georges; Haverlag, Marco

    2010-06-01

    Light sources play an indispensable role in the daily life of any human being. Quality of life, health and urban security related to traffic and crime prevention depend on light and on its quality. In fact, every day approximately 30 billion electric light sources operate worldwide. These electric light sources consume almost 19% of worldwide electricity production. Finding new ways to light lamps is a challenge where the stakes are scientific, technological, economic and environmental. The production of more efficient light sources is a sustainable solution for humanity. There are many opportunities for not only enhancing the efficiency and reliability of lighting systems but also for improving the quality of light as seen by the end user. This is possible through intelligent use of new technologies, deep scientific understanding of the operating principles of light sources and knowledge of the varied human requirements for different types of lighting in different settings. A revolution in the domain of light source technology is on the way: high brightness light emitting diodes arriving in the general lighting market, together with organic LEDs (OLEDs), are producing spectacular advances. However, unlike incandescence, electrical discharge lamps are far from disappearing from the market. In addition, new generations of discharge lamps based on molecular radiators are becoming a reality. There are still many scientific and technological challenges to be raised in this direction. Diagnostics are important for understanding the fundamental mechanisms taking place in the discharge plasma. This understanding is an absolute necessity for system optimization leading to more efficient and high quality light sources. The studied medium is rather complex, but new diagnostic techniques coupled to innovative ideas and powerful tools have been developed in recent years. This cluster issue of seven papers illustrates these efforts. The selected papers cover all domains, from

  13. Intraocular light scatter, reflections, fluorescence and absorption: what we see in the slit lamp.

    Science.gov (United States)

    van den Berg, Thomas J T P

    2018-01-01

    Much knowledge has been collected over the past 20 years about light scattering in the eye- in particular in the eye lens- and its visual effect, called straylight. It is the purpose of this review to discuss how these insights can be applied to understanding the slit lamp image. The slit lamp image mainly results from back scattering, whereas the effects on vision result mainly from forward scatter. Forward scatter originates from particles of about wavelength size distributed throughout the lens. Most of the slit lamp image originates from small particle scatter (Rayleigh scatter). For a population of middle aged lenses it will be shown that both these scatter components remove around 10% of the light from the direct beam. For slit lamp observation close to the reflection angles, zones of discontinuity (Wasserspalten) at anterior and posterior parts of the lens show up as rough surface reflections. All these light scatter effects increase with age, but the correlations with age, and also between the different components, are weak. For retro-illumination imaging it will be argued that the density or opacity seen in areas of cortical or posterior subcapsular cataract show up because of light scattering, not because of light loss. NOTES: (1) Light scatter must not be confused with aberrations. Light penetrating the eye is divided into two parts: a relatively small part is scattered, and removed from the direct beam. Most of the light is not scattered, but continues as the direct beam. This non-scattered part is the basis for functional imaging, but its quality is under the control of aberrations. Aberrations deflect light mainly over small angles (light scatter is important because of the straylight effects over large angles (>1°), causing problems like glare and hazy vision. (2) The slit lamp image in older lenses and nuclear cataract is strongly influenced by absorption. However, this effect is greatly exaggerated by the light path lengths concerned. This

  14. Lung surgery - discharge

    Science.gov (United States)

    ... Lung biopsy - discharge; Thoracoscopy - discharge; Video-assisted thoracoscopic surgery - discharge; VATS - discharge ... milk) for 2 weeks after video-assisted thoracoscopic surgery and 6 to 8 weeks after open surgery. ...

  15. Hysterectomy - vaginal - discharge

    Science.gov (United States)

    Vaginal hysterectomy - discharge; Laparoscopically assisted vaginal hysterectomy - discharge; LAVH - discharge ... you are unable to urinate. You have a discharge from your vagina that has a bad odor. You have bleeding ...

  16. Pediatric heart surgery - discharge

    Science.gov (United States)

    ... discharge; Heart valve surgery - children - discharge; Heart surgery - pediatric - discharge; Heart transplant - pediatric - discharge ... Geme JW, Schor NF, eds. Nelson Textbook of Pediatrics . 20th ed. Philadelphia, PA: Elsevier; 2016:chap 434. ...

  17. Hip replacement - discharge

    Science.gov (United States)

    ... discharge; Total hip replacement - discharge; Hip hemiarthroplasty - discharge; Osteoarthritis - hip replacement discharge ... such as downhill skiing or contact sports like football and soccer. But you should be able to ...

  18. 49 CFR 571.108, Nt. - Standard No. 108; Lamps, reflective devices, and associated equipment.

    Science.gov (United States)

    2010-10-01

    ....4Except for multifunction school activity buses, each school bus shall be equipped with a system of either: (a) Four red signal lamps designed to conform to SAE Standard J887, School Bus Red Signal Lamps, July... to SAE Standard J887, School Bus Red Signal Lamps, July 1964, and four amber signal lamps designed to...

  19. In-situ measurements of material thermal parameters for accurate LED lamp thermal modelling

    NARCIS (Netherlands)

    Vellvehi, M.; Perpina, X.; Jorda, X.; Werkhoven, R.J.; Kunen, J.M.G.; Jakovenko, J.; Bancken, P.; Bolt, P.J.

    2013-01-01

    This work deals with the extraction of key thermal parameters for accurate thermal modelling of LED lamps: air exchange coefficient around the lamp, emissivity and thermal conductivity of all lamp parts. As a case study, an 8W retrofit lamp is presented. To assess simulation results, temperature is

  20. LED Light Characteristics for Surgical Shadowless Lamps and Surgical Loupes

    OpenAIRE

    Ide, Takeshi; Kinugawa, Yoshitaka; Nobae, Yuichi; Suzuki, Toshihiro; Tanaka, Yoshiyuki; Toda, Ikuko; Tsubota, Kazuo

    2015-01-01

    Background: Blue light has more energy than longer wavelength light and can penetrate the eye to reach the retina. When surgeons use magnifying loupes under intensive surgical shadowless lamps for better view of the surgical field, the total luminance is about 200 times brighter than that of typical office lighting. In this study, the effects of 2 types of shadowless lamps were compared. Moreover, the effect of various eyeglasses, which support magnifying loupes, on both the light energy and ...

  1. LAM Pilot Study with Imatinib Mesylate (LAMP-1)

    Science.gov (United States)

    2015-10-01

    AD______________ AWARD NUMBER: W81XWH-14-1-0132 TITLE: LAM Pilot Study with Imatinib Mesylate (LAMP-1) PRINCIPAL INVESTIGATOR: Charlie...AND SUBTITLE LAM Pilot Study with Imatinib Mesylate (LAMP-1) 5a. CONTRACT NUMBER 5b. GRANT NUMBER W81XWH-14-1-0132 5c. PROGRAM ELEMENT...designed to generate short-term safety and efficacy data regarding imatinib mesylate ( imatinib ) in the treatment of Lymphangioleiomyomatosis (LAM

  2. Decolorization of brilliant green dye using immersed lamp sonophotocatalytic reactor

    Science.gov (United States)

    Gole, Vitthal L.; Priya, Astha; Danao, Sanjay P.

    2017-12-01

    The textile and dye industries require an enormous amount of water for processing and produce a large volume of wastewater. Generated wastewater had potential hazards and a threat to the aquatic biota. The present work investigates the decolorization of brilliant green dye using a combination of two advanced oxidation techniques viz sonocatalysis and photocatalysis (immersed lamp) known as sonophotocatalysis (3 L capacity). The efficiency of decolorization is further improved in the presence of various additives viz. copper oxide, zinc oxide, and sodium chloride. The maximum decolorization of brilliant green (BG) (94.8% in 120 min) obtained in the presence of zinc oxide. The total organic carbon of the treated samples was measured to monitor complete mineralization of BG. The sonophotocatalytic process (in the presence of zinc oxide) shows maximum mineralization. Synergic combination of two oxidation processes increased the production of oxidizing radicals. Continuous cleaning of catalyst surface (due to sonolysis effect) improves the activity of the catalyst for photolysis operation. The present work is highly useful for the development of a sonophotocatalytic process.

  3. Development and commercialisation of rechargeable wooden LED lamps

    Directory of Open Access Journals (Sweden)

    Bradley Schultz

    2013-02-01

    Full Text Available The focus of this project was to work with local staff at Kathmandu Alternative Power and Energy Group to commercialise a product which would generate recurring income for the organisation, to enable staff to learn the process of commercialisation and to provide employment and skills in the local community. Rechargeable Light Emitting Diode (LED lamps were deemed suitable for these aims, as they are a simple product, yet one that is urgently required in Nepal due to the prevalence of ‘load-shedding’ – scheduled electrical blackouts. After reviewing the market, it was found that it would be impossible to compete with the price of cheap imported Chinese rechargeable LED lamps, so an alternative approach was taken. This involved sourcing wooden off-cuts from a local furniture factory and transforming them into attractive desk lamps, with the target market being affluent Nepalis, ex-pats living in Nepal and tourists. Successful initial sales were achieved through a Kathmandu-based ex-pat email group, hotel-markets and souvenir stores. KAPEG staff have continued the project, producing variations on the initial design including Himalayan rock salt lamps, employing local people to manufacture lamps and selling them at markets in Kathmandu. Staffing and marketing challenges remain to ensure the lamp manufacture and sales continue.

  4. LRO-LAMP failsafe door-open performance: improving FUV measurements of dayside lunar hydration

    Science.gov (United States)

    Davis, Michael W.; Greathouse, Thomas K.; Kaufmann, David E.; Retherford, Kurt D.; Versteeg, Maarten H.

    2017-08-01

    The Lunar Reconnaissance Orbiter's (LRO) Lyman Alpha Mapping Project (LAMP) is a lightweight (6.1 kg), lowpower (4.5 W), ultraviolet spectrograph based on the Alice instruments aboard the European Space Agency's Rosetta spacecraft and NASA's New Horizons spacecraft. Its primary job is to identify and localize exposed water frost in permanently shadowed regions (PSRs) near the Moon's poles, and to characterize landforms and albedos in PSRs. LRO launched on June 18, 2009 and reached lunar orbit four days later. LAMP operated with its failsafe door closed for its first seven years in flight. The failsafe door was opened in October 2016 to increase light throughput during dayside operations at the expense of no longer having the capacity to take further dark observations and slightly more operational complexity to avoid saturating the instrument. This one-time irreversible operation was approved after extensive review, and was conducted flawlessly. The increased throughput allows measurement of dayside hydration in one orbit, instead of averaging multiple orbits together to reach enough signal-to-noise. The new measurement mode allows greater time resolution of dayside water migration for improved investigations into the source and loss processes on the lunar surface. LAMP performance and optical characteristics after the failsafe door opening are described herein, including the new effective area, wavelength solution, and resolution.

  5. Pathogen control in complex fluids with water-coupled excimer lamps at 282 and 308 nm.

    Science.gov (United States)

    Coogan, John J

    2005-01-01

    Water-coupled excimer lamp systems have been developed to inactivate microorganisms within complex, low-optical quality, fluids. Monochromatic lamps were selected to minimize UV-B and UV-C absorption within the carrier fluids while maximizing deposition within specific chemical targets. Fundamentals, system scaling and power supply design are discussed. This work used two large-surface area excimer lamps as intense sources of near monochromatic radiation at 308 and 282 nm. Data are presented for two distinct fluid systems: flow-through processing of large-volume metalworking fluids used in heavy industry and batch irradiation of human blood plasma and platelet suspensions used in transfusion medicine. In the first, a 200-600 L/min reactor is used to control bacterial concentrations within metalworking fluids used in large-scale metal machining processes. Control is defined as the maintenance of 10(3) to 10(4) CFU/mL in fluids that without treatment would have concentrations over 10(7) CFU/mL. The second is a batch process for viral inactivation in undiluted blood bank products. Samples of fresh frozen plasma and platelet suspensions were spiked with high titers of porcine parvovirus (PPV) and irradiated at 308 and 282 nm. Although both wavelengths were effective at reducing PPV levels, 308 nm light resulted in both higher rates of viral inactivation (greater than 6 log units) and lower rates of fluid degradation.

  6. Fluorescence and Fourier-transform infrared spectroscopy for the analysis of iconic Italian design lamps made of polymeric materials.

    Science.gov (United States)

    Toja, Francesca; Nevin, Austin; Comelli, Daniela; Levi, Marinella; Cubeddu, Rinaldo; Toniolo, Lucia

    2011-03-01

    The preservation of design object collections requires an understanding of their constituent materials which are often polymeric blends. Challenges associated with aging of complex polymers from objects with an unknown physical history may compromise the interpretation of data from analytical techniques, and therefore complicate the assessment of the condition of polymers in indoor museum environments. This study focuses on the analysis of polymeric materials from three well-known Italian design lamps from the 1960s. To assess the degree of chemical modifications in the polymers, non-destructive molecular spectroscopic techniques, Fourier-transform infrared (FTIR) and fluorescence spectroscopy, have been applied directly on the object surfaces using an optical fiber probe and through examination of micro samples. FTIR spectra of the different polymers, polyvinylacetate (PVAc) for the lamps Taraxacum and Fantasma, and both acrylonitrile-butadiene-styrene polymer (ABS) and cellulose acetate (CA) for the lamp Nesso, allowed the detection of ongoing deterioration processes. Fluorescence spectroscopy proved particularly sensitive for the detection of molecular changes in the polymeric objects, as the spectra obtained from the examined lamps differ significantly from those of the unaged reference materials. Differences in fluorescence spectra are also detected between different points on the same object further indicating the presence of different chemical species on the surfaces. With the aid of complementary data from FTIR spectroscopy, an interpretation of the emission spectra of the studied polymeric objects is here proposed, further suggesting that fluorescence spectroscopy may be useful for following the degradation of historical polymeric objects.

  7. Determination of mercury distribution inside spent compact fluorescent lamps by atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Rey-Raap, Natalia; Gallardo, Antonio

    2012-01-01

    Highlights: ► New treatments for CFL are required considering the aim of Directive 202/96/CE. ► It is shown that most of the mercury introduced into a CFL is in the phosphor powder. ► Experimental conditions for microwave-assisted sample digestion followed by AAS measurements are described. ► By washing the glass it is possible to reduce the concentration below legal limits. - Abstract: In this study, spent compact fluorescent lamps were characterized to determine the distribution of mercury. The procedure used in this research allowed mercury to be extracted in the vapor phase, from the phosphor powder, and the glass matrix. Mercury concentration in the three phases was determined by the method known as cold vapor atomic absorption spectrometry. Median values obtained in the study showed that a compact fluorescent lamp contained 24.52 ± 0.4 ppb of mercury in the vapor phase, 204.16 ± 8.9 ppb of mercury in the phosphor powder, and 18.74 ± 0.5 ppb of mercury in the glass matrix. There are differences in mercury concentration between the lamps since the year of manufacture or the hours of operation affect both mercury content and its distribution. The 85.76% of the mercury introduced into a compact fluorescent lamp becomes a component of the phosphor powder, while more than 13.66% is diffused through the glass matrix. By washing and eliminating all phosphor powder attached to the glass surface it is possible to classified the glass as a non-hazardous waste.

  8. CALiPER Benchmark Report: Performance of T12 and T8 Fluorescent Lamps and Troffers and LED Linear Replacement Lamps

    Energy Technology Data Exchange (ETDEWEB)

    Myer, M. A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Paget, M. L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Lingard, R. D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2009-01-01

    This report examines standard fluorescent lamps, the recessed troffers they are commonly used in, and available LED replacements for T12 and T8 fluorescent lamps and their application in fluorescent troffers.

  9. Microwave discharges in capillary tubes

    International Nuclear Information System (INIS)

    Dervisevic, Emil

    1984-01-01

    This research thesis aims at being a contribution to the study of microwave discharge by a surface wave, and more precisely focusses on the discharge in capillary tubes filled with argon. The author first present theoretical models which describe, on the one hand, the propagation of the surface wave along the plasma column, and, on the other hand, longitudinal and radial profiles of the main discharge characteristics. The second part addresses the study of the influence of parameters (gas pressure and tube radius) on discharge operation and characteristics. Laws of similitude as well as empirical relationships between argon I and argon II emission line intensities, electron density, and electric field in the plasma have been established [fr

  10. CARS diagnostics of high pressure discharges

    International Nuclear Information System (INIS)

    Uhlenbusch, J.

    2001-01-01

    After a short description of the principles of the CARS, RECARS and POLCARS techniques and a discussion of setups for CARS experiments some experimental results are summarized. The results concern mainly plasma under atmospheric pressure, in particular the determination of temperature in a CO 2 laser-induced pyrolysis flame burning in a silane-acetylene gas mixture, the measurements of N 2 vibrational and rotational temperatures as well as the electron density by CARS and of an NO minority by POLCARS in an atmospheric microwave discharge, and finally RECARS experiments on indium iodide, Which is present in metal halide discharge lamps. Guided by these examples some problems and difficulties arising when performing CARS measurements are discussed

  11. Discharge, suspended sediment, and salinity in the Gulf Intracoastal Waterway and adjacent surface waters in South-Central Louisiana, 1997–2008

    Science.gov (United States)

    Swarzenski, Christopher M.; Perrien, Scott M.

    2015-10-19

    Discharge, suspended sediment, and salinity data collected between 1997 and 2008 indicate that the Gulf Intracoastal Waterway (GIWW) is an important distributary of river water and suspended sediments to coastal wetlands in south-central coastal Louisiana. Following natural hydraulic gradients, the GIWW passively distributes freshwater and suspended sediments from the Atchafalaya River to areas at least 30 to 50 miles west and east, respectively, of Morgan City. The magnitude and reach of the discharge in the GIWW increase as stage of the Wax Lake Outlet at Calumet and Lower Atchafalaya River (LAR) at Morgan City increase. The magnitude and duration of discharge vary from year to year depending on the flow regime of the Atchafalaya River. Annual discharge of water in the GIWW was greater during years when stage of the LAR remained anomalously high throughout the year, compared with average and peak flood years. During years when Atchafalaya River flow is low, Bayou Boeuf, a waterway draining the Verret subbasin, becomes a major source of water maintaining the eastward flow in the GIWW. The GIWW is the only means of getting river water to some parts of coastal Louisiana.

  12. Compact fluorescent lamp phosphors in accidental radiation monitoring

    International Nuclear Information System (INIS)

    Murthy, K. V. R.; Pallavi, S. P.; Ghildiyal, R.; Parmar, M. C.; Patel, Y. S.; Ravi Kumar, V.; Sai Prasad, A. S.; Natarajan, V.; Page, A. G.

    2006-01-01

    The application of lamp phosphors for accidental dosimetry is a new concept. Since the materials used in fluorescent lamps are good photo luminescent materials, if one can either use the inherent defects present in the phosphor or add suitable modifiers to induce thermoluminescence (TL) in these phosphors, then the device (fluorescent lamp) can be used as an accidental dosemeter. In continuation of our search for a suitable phosphor material, which can serve both as an efficient lamp phosphor and as a good radiation monitoring device, detailed examination has been carried out on cerium and terbium-doped lanthanum phosphate material. A 90 Sr beta source with 50 mCi strength (1.85 GBq) was used as the irradiation source for TL studies. The TL response as a function of dose received was examined for all phosphors used and it was observed that the intensity of the TL peak vs. dose received was a linear function in the dose range 0.1-200 Gy in each case. Incidentally LaPO 4 :Ce,Tb is a component of the compact fluorescent lamp marketed recently as an energy bright light source. Besides having very good luminescence efficiency, good dosimetric properties of these phosphors render them useful for their use in accidental dosimetry also. (authors)

  13. Shader Lamps Virtual Patients: the physical manifestation of virtual patients.

    Science.gov (United States)

    Rivera-Gutierrez, Diego; Welch, Greg; Lincoln, Peter; Whitton, Mary; Cendan, Juan; Chesnutt, David A; Fuchs, Henry; Lok, Benjamin

    2012-01-01

    We introduce the notion of Shader Lamps Virtual Patients (SLVP) - the combination of projector-based Shader Lamps Avatars and interactive virtual humans. This paradigm uses Shader Lamps Avatars technology to give a 3D physical presence to conversational virtual humans, improving their social interactivity and enabling them to share the physical space with the user. The paradigm scales naturally to multiple viewers, allowing for scenarios where an instructor and multiple students are involved in the training. We have developed a physical-virtual patient for medical students to conduct ophthalmic exams, in an interactive training experience. In this experience, the trainee practices multiple skills simultaneously, including using a surrogate optical instrument in front of a physical head, conversing with the patient about his fears, observing realistic head motion, and practicing patient safety. Here we present a prototype system and results from a preliminary formative evaluation of the system.

  14. Radiation safety aspects of fluorescent lamp starters incorporating radiation source

    International Nuclear Information System (INIS)

    Sadagopan, Geetha; Shukla, V.K.

    2000-01-01

    A fluorescent lamp starter is a switch applies the voltage to the fluorescent tube after sufficient preheating to allow the tube to conduct an electric current. Radioactive substances used in the starters are 85 Kr, 147 Pm, 3 H and 232 Th. In India, fluorescent lamp starters are classified as consumer products and users are outside regulatory control. However, regulatory control is exercised over the manufacturers at the production stage. Tritium activity measured in the lamp starters ranged from 400-4500 Bq with a mean activity of 1.78 kBq. Thorium activity measured varied from 0.44-3.3 mg. The results of radiation safety assessment of the workplace and radioactivity estimation in the starters are discussed in this paper. (author)

  15. Inventing around Edison’s incandescent lamp patent

    DEFF Research Database (Denmark)

    Howells, John; Ron D, Katznelson

    We provide an anatomy of the influence of Edison’s incandescent lamp patent U.S. 223,898 on downstream development and show how subsequent inventor activity adjusts to the improved certainty provided by court decisions as to the boundaries of a patent’s claims. First, we show that court decisions...... upholding Edison’s patent generated a surge of patent filings in the incandescent lamp classes at the U.S. Patent Office. Second, by inspection of the specifications of these later patents we are able to categorize certain design-around efforts by their evasion of specific elements of the claims of Edison......’s ‘898 patent. Third, by analysis of forward citation to these patents we show that regardless of these inventions’ commercial viability in the incandescent lamp market, some became important prior art for new technological fields and some laid the groundwork for the later successful substitute...

  16. Inventing around Edison’s Incandescent Lamp Patent

    DEFF Research Database (Denmark)

    Howells, John; Katznelson, Ron D.

    We provide an anatomy of the influence of Edison’s incandescent lamp patent U.S. 223,898 on downstream development and show how subsequent inventor activity adjusts to the improved certainty provided by court decisions as to the boundaries of a patent’s claims. First, we show that court decisions...... upholding Edison’s patent generated a surge of patent filings in the incandescent lamp classes at the U.S. Patent Office. Second, by inspection of the specifications of these later patents we are able to categorize certain design-around efforts by their evasion of specific elements of the claims of Edison......’s ‘898 patent. Third, by analysis of forward citation to these patents we show that regardless of these inventions’ commercial viability in the incandescent lamp market, some became important prior art for new technological fields and some laid the groundwork for the later successful substitute...

  17. Ankle replacement - discharge

    Science.gov (United States)

    ... total - discharge; Total ankle arthroplasty - discharge; Endoprosthetic ankle replacement - discharge; Osteoarthritis - ankle ... You had an ankle replacement. Your surgeon removed and reshaped ... an artificial ankle joint. You received pain medicine and were ...

  18. Tennis elbow surgery - discharge

    Science.gov (United States)

    Lateral epicondylitis surgery - discharge; Lateral tendinosis surgery - discharge; Lateral tennis elbow surgery - discharge ... Soon after surgery, severe pain will decrease, but you may have mild soreness for 3 to 6 months.

  19. Knee joint replacement - discharge

    Science.gov (United States)

    ... Knee replacement - total - discharge; Tricompartmental knee replacement - discharge; Osteoarthritis - knee replacement discharge ... such as downhill skiing or contact sports like football and soccer. But, you should be able to ...

  20. Corneal perforation secondary to UV radiation from a tanning lamp.

    Science.gov (United States)

    Funnell, Charlotte; Watson, Keith; Stewart, Owen; Dua, Gurcharan

    2006-12-01

    To report the case of a patient with keratoconus who developed a corneal perforation secondary to UV radiation from a tanning lamp. We believe this to be the first case of a corneal perforation secondary to UV radiation. The presentation and management of the patient and the pathophysiology of UV keratitis are discussed. Our patient developed a full-thickness corneal perforation after 30 minutes of tanning lamp exposure without eye protection. The cornea was temporized with cyanoacrylate tissue adhesive until penetrating keratoplasty could be performed. With an increased understanding of the pathophysiology of UV damage, treatment should be aimed at modulating the disease to reduce the likelihood of a poor outcome.