WorldWideScience

Sample records for plasma vitrified air

  1. Properties of sintered glass-ceramics prepared from plasma vitrified air pollution control residues.

    Science.gov (United States)

    Roether, J A; Daniel, D J; Rani, D Amutha; Deegan, D E; Cheeseman, C R; Boccaccini, A R

    2010-01-15

    Air pollution control (APC) residues, obtained from a major UK energy from waste (EfW) plant, processing municipal solid waste, have been blended with silica and alumina and melted using DC plasma arc technology. The glass produced was crushed, milled, uni-axially pressed and sintered at temperatures between 750 and 1150 degrees C, and the glass-ceramics formed were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Mechanical properties assessed included Vickers's hardness, flexural strength, Young's modulus and thermal shock resistance. The optimum sintering temperature was found to be 950 degrees C. This produced a glass-ceramic with high density (approximately 2.58 g/cm(3)), minimum water absorption (approximately 2%) and relatively high mechanical strength (approximately 81+/-4 MPa). Thermal shock testing showed that 950 degrees C sintered samples could withstand a 700 degrees C quench in water without micro-cracking. The research demonstrates that glass-ceramics can be readily formed from DC plasma treated APC residues and that these have comparable properties to marble and porcelain. This novel approach represents a technically and commercially viable treatment option for APC residues that allow the beneficial reuse of this problematic waste.

  2. On Vitrifying Wastes Using a Plasma Arc Torch

    Science.gov (United States)

    2002-08-01

    environmental research and waste management policy. She labored in a milieu of resource shortage , severe time constraints and borrowed facilities...municipal solid waste) a syngas may also be collected during vitrification and either sold or used on site to power the torch itself. Finally, plasma

  3. Successful Production of Piglets Derived from Expanded Blastocysts Vitrified Using a Micro Volume Air Cooling Method without Direct Exposure to Liquid Nitrogen

    OpenAIRE

    MISUMI, Koji; Hirayama, Yuri; EGAWA, Sachiko; Yamashita, Shoko; HOSHI, Hiroyoshi; Imai, Kei

    2013-01-01

    Abstract This study was conducted to clarify the feasibility of newly developed vitrification techniques for porcine embryos using the micro volume air cooling (MVAC) method without direct contact with liquid nitrogen (LN2). Expanded blastocysts were vitrified in a solution containing 6 M ethylene glycol, 0.6 M trehalose and 2% (wt/vol) polyethylene glycol in 10% HEPES-buffered PZM-5. The blastocysts were collected from gilts and vitrified using the new device (MVAC) or a Cryotop (CT). Blasto...

  4. The relationship between oxygen consumption rate and viability of in vivo-derived pig embryos vitrified by the micro volume air cooling method.

    Science.gov (United States)

    Sakagami, N; Nishida, K; Misumi, K; Hirayama, Y; Yamashita, S; Hoshi, H; Misawa, H; Akiyama, K; Suzuki, C; Yoshioka, K

    2016-01-01

    The aim of this study was to assess the viability of vitrified-warmed in vivo-derived pig embryos after measuring the oxygen consumption rate. Six days after artificial insemination, blastocysts were collected from gilts and vitrified by the micro volume air cooling method. The oxygen consumption rate was measured in 60 vitrified-warmed embryos, which were then cultured for 48h to assess the viability. The survival (re-expansion) rate of embryos after warming was 85.0%. The average oxygen consumption rate of embryos immediately after warming was greater in embryos which could re-expand during subsequent culture (F=0.75±0.04) than that in those which failed to re-expand (F=0.33±0.05). Moreover, the oxygen consumption rate of vitrified-warmed embryos was greater in the hatched (F=0.88±0.06) than that in the not-hatched group (F=0.53±0.04). When the oxygen consumption rate of the vitrified-warmed embryos and the numbers of viable and dead cells in embryos were determined, there was a positive correlation between the oxygen consumption rate and the number of live cells (Pconsumption rate were surgically transferred into uterine horns of two recipients. Both of the recipients become pregnant and farrowed 12 healthy piglets. These results demonstrate that the oxygen consumption rate of vitrified-warmed pig embryos can be related to the number of live cells and that the measurement of oxygen consumption of embryos after cryopreservation may be useful for estimating embryo survivability.

  5. Successful production of piglets derived from expanded blastocysts vitrified using a micro volume air cooling method without direct exposure to liquid nitrogen.

    Science.gov (United States)

    Misumi, Koji; Hirayama, Yuri; Egawa, Sachiko; Yamashita, Shoko; Hoshi, Hiroyoshi; Imai, Kei

    2013-12-17

    This study was conducted to clarify the feasibility of newly developed vitrification techniques for porcine embryos using the micro volume air cooling (MVAC) method without direct contact with liquid nitrogen (LN₂). Expanded blastocysts were vitrified in a solution containing 6 M ethylene glycol, 0.6 M trehalose and 2% (wt/vol) polyethylene glycol in 10% HEPES-buffered PZM-5. The blastocysts were collected from gilts and vitrified using the new device (MVAC) or a Cryotop (CT). Blastocysts were stored in LN₂ for at least 1 month. After warming, cryoprotective agents were removed using a single step. Survival of the embryos was assessed by in vitro culture (Experiment 1) and by embryo transfer to recipients (Experiment 2). In Experiment 1, the embryos vitrified by the MVAC or CT and fresh embryos without vitrification (Control) were used. The survival rates of embryos in the MVAC, CT and Control groups were 88.9% (32/36), 91.7% (33/36) and 100% (34/34), respectively, after 48 h culture, and the hatching rates of embryos after 48 h incubation were 69.4% (25/36), 63.9% (23/36) and 94.1% (32/34), respectively. In Experiment 2, 64 vitrified embryos were transferred to 5 recipient gilts, and 8 healthy piglets were produced from 3 recipients in the MVAC group. Similarly, 66 vitrified embryos were transferred to 5 recipient gilts, and 9 healthy piglets were produced from 2 recipients in the CT group. These results indicated that porcine expanded blastocysts can be cryopreserved using the MVAC method without potential pathogen contamination from LN₂.

  6. Screening in humid air plasmas

    Science.gov (United States)

    Filippov, Anatoly; Derbenev, Ivan; Dyatko, Nikolay; Kurkin, Sergey

    2016-09-01

    Low temperature air plasmas containing H2O molecules are of high importance for atmospheric phenomena, climate control, biomedical applications, surface processing, and purification of air and water. Humid air plasma created by an external ionization source is a good model of the troposphere where ions are produced by the galactic cosmic rays and decay products of air and soil radioactive elements such as Rn222. The present paper is devoted to study the ionic composition and the screening in an ionized humid air at atmospheric pressure and room temperature. The ionization rate is varied in the range of 101 -1018 cm-3s-1. The humid air with 0 - 1 . 5 % water admixture that corresponds to the relative humidity of 0 - 67 % at the air temperature equal to 20°C is considered. The ionic composition is determined on the analysis of more than a hundred processes. The system of 41 non-steady state particle number balance equations is solved using the 4th order Runge-Kutta method. The screening of dust particle charge in the ionized humid air are studied within the diffusion-drift approach. The screening constants are well approximated by the inverse Debye length and characteristic lengths of recombination and attachment processes. This work was supported by the Russian Science Foundation, Project No. 16-12-10424.

  7. DC Arc Plasma Disposal of Printed Circuit Board

    Institute of Scientific and Technical Information of China (English)

    黄建军; 施嘉标; 孟月东; 刘正之

    2004-01-01

    A new solid waste disposal technology setup with DC arc plasma is presented. Being different from conventional combustion or burning such as incineration, it is based on a process called controlled high-temperature pyrolysis, the thermal destruction and recovery process. The results of vitrification of the circuit board is presented. The properties of vitrified product including hardness and leaching test results are presented. The final product (vitrified material) and air emission from the plasma treatment is environmentally acceptable.

  8. Plasma Air Decontamination System (PADS) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed Plasma Air Decontamination System (PADS) is a trace contaminant control device based on non-thermal atmospheric pressure plasma technology that operates...

  9. Plasma Air Decontamination System (PADS) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed Plasma Air Decontamination System (PADS) is a trace contaminant control device based on non-thermal atmospheric-pressure plasma technology. Compared to...

  10. Microwave Probing of Air-Plasma and Plasma Metamaterials

    Science.gov (United States)

    Schneider, Katherine; Rock, Ben; Helle, Mike

    2016-10-01

    Plasma metamaterials are of recent interest due to their unique ability to be engineered with specific electromagnetic responses. One potential metamaterial architecture is based on a `forest' of plasma rods that can be produced using intense laser plasma filaments. In our work, we use a continuous microwave source at 26.5 GHz to measure a single air plasma filament characteristics generated from a 5 mJ laser pulse within a cylindrical hole in a Ka-band waveguide. Preliminary results show the air plasma produces a strong shock and acts to reflect microwave radiation. A computational comparison using 3D EM modeling is performed to examine the reflection and transmission properties of a single plasma rod, and further, to investigate an array of plasma rods as a potential plasma based metamaterial.

  11. Antimicrobial Applications of Ambient--Air Plasmas

    Science.gov (United States)

    Pavlovich, Matthew John

    The emerging field of plasma biotechology studies the applications of the plasma phase of matter to biological systems. "Ambient-condition" plasmas created at or near room temperature and atmospheric pressure are especially promising for biomedical applications because of their convenience, safety to patients, and compatibility with existing medical technology. Plasmas can be created from many different gases; plasma made from air contains a number of reactive oxygen and nitrogen species, or RONS, involved in various biological processes, including immune activity, signaling, and gene expression. Therefore, ambient-condition air plasma is of particular interest for biological applications. To understand and predict the effects of treating biological systems with ambient-air plasma, it is necessary to characterize and measure the chemical species that these plasmas produce. Understanding both gaseous chemistry and the chemistry in plasma-treated aqueous solution is important because many biological systems exist in aqueous media. Existing literature about ambient-air plasma hypothesizes the critical role of reactive oxygen and nitrogen species; a major aim of this dissertation is to better quantify RONS by produced ambient-air plasma and understand how RONS chemistry changes in response to different plasma processing conditions. Measurements imply that both gaseous and aqueous chemistry are highly sensitive to operating conditions. In particular, chemical species in air treated by plasma exist in either a low-power ozone-dominated mode or a high-power nitrogen oxide-dominated mode, with an unstable transition region at intermediate discharge power and treatment time. Ozone (O3) and nitrogen oxides (NO and NO2, or NOx) are mutually exclusive in this system and that the transition region corresponds to the transition from ozone- to nitrogen oxides-mode. Aqueous chemistry agrees well with to air plasma chemistry, and a similar transition in liquid-phase composition

  12. Survival of oocytes recovered from vitrified sheep ovarian tissues.

    Science.gov (United States)

    Al-aghbari, A M; Menino, A R

    2002-05-15

    The objective of this work was to develop an effective vitrification technique for cryopreserving oocytes in sheep ovarian tissues. Ovaries were surgically recovered from 15 pubertal ewes and the ovarian cortex was cut into sections. Ovarian tissues were placed in equilibration medium consisting of 4% (v/v) ethylene glycol (EG) and 20% (v/v) FBS in TCM-199 on ice for 30 min and transferred to vitrification solution (35% EG, 5% polyvinylpyrrolidone, 0.4M trehalose and 20% FBS in TCM-199) for 5 min. Ovarian tissues were vitrified by dropping the tissue on the surface of a steel cube cooled by liquid nitrogen. Cumulus-enclosed oocyte complexes (COC) were also collected and vitrified following the procedure used for ovarian tissues. After 2-3 weeks of storage in liquid nitrogen, ovarian tissues and COC were thawed at 37 degrees C in 0.3M trehalose and COC in ovarian tissues were mechanically and enzymatically isolated. Vitrified COC and freshly collected COC were washed twice in maturation medium (TCM-199 supplemented with 0.255 mM pyruvate and 10% heat-treated estrus cow serum) and cultured in 50 microl drops of maturation medium under paraffin oil for 23-25h at 39 degrees C in a humidified atmosphere of 5% CO(2) in air. After culture, cumulus cells were removed by hyaluronidase treatment and vortexing and oocytes were fixed and stained. No significant differences were observed between vitrified oocytes, oocytes recovered from vitrified ovarian tissues and non-vitrified control oocytes in the percentage of oocytes with acceptable staining per total number of oocytes fixed or with visible chromatin per total number of oocytes with acceptable staining. However, fewer (P0.05) were observed due to treatment in the percentages of oocytes developing to metaphase II. These results demonstrate that sheep oocytes can be successfully cryopreserved by vitrification of ovarian tissues and exhibit in vitro maturation rates similar to that of vitrified and non-vitrified oocytes.

  13. Air plasma effect on dental disinfection

    Energy Technology Data Exchange (ETDEWEB)

    Duarte, S.; Murata, R. M.; Saxena, D. [Department of Basic Sciences and Craniofacial Biology, College of Dentistry, New York University, New York, New York 10010 (United States); Kuo, S. P.; Chen, C. Y.; Huang, K. J. [Department of Electrical and Computer Engineering, Polytechnic Institute of New York University, Brooklyn, New York 11202 (United States); Popovic, S. [Department of Physics, Old Dominion University, Norfolk, Virginia 23529 (United States)

    2011-07-15

    A nonthermal low temperature air plasma jet is characterized and applied to study the plasma effects on oral pathogens and biofilms. Experiments were performed on samples of six defined microorganisms' cultures, including those of gram-positive bacteria and fungi, and on a cultivating biofilm sample of Streptococcus mutans UA159. The results show that the plasma jet creates a zone of microbial growth inhibition in each treated sample; the zone increases with the plasma treatment time and expands beyond the entire region directly exposed to the plasma jet. With 30s plasma treatment twice daily during 5 days of biofilm cultivation, its formation was inhibited. The viability of S. mutans cells in the treated biofilms dropped to below the measurable level and the killed bacterial cells concentrated to local regions as manifested by the fluorescence microscopy via the environmental scanning electron microscope. The emission spectroscopy of the jet indicates that its plasma effluent carries an abundance of reactive atomic oxygen, providing catalyst for the observed plasma effect.

  14. Air plasma effect on dental disinfection

    Science.gov (United States)

    Duarte, S.; Kuo, S. P.; Murata, R. M.; Chen, C. Y.; Saxena, D.; Huang, K. J.; Popovic, S.

    2011-07-01

    A nonthermal low temperature air plasma jet is characterized and applied to study the plasma effects on oral pathogens and biofilms. Experiments were performed on samples of six defined microorganisms' cultures, including those of gram-positive bacteria and fungi, and on a cultivating biofilm sample of Streptococcus mutans UA159. The results show that the plasma jet creates a zone of microbial growth inhibition in each treated sample; the zone increases with the plasma treatment time and expands beyond the entire region directly exposed to the plasma jet. With 30s plasma treatment twice daily during 5 days of biofilm cultivation, its formation was inhibited. The viability of S. mutans cells in the treated biofilms dropped to below the measurable level and the killed bacterial cells concentrated to local regions as manifested by the fluorescence microscopy via the environmental scanning electron microscope. The emission spectroscopy of the jet indicates that its plasma effluent carries an abundance of reactive atomic oxygen, providing catalyst for the observed plasma effect.

  15. Vitrified waste option study report

    Energy Technology Data Exchange (ETDEWEB)

    Lopez, D.A.; Kimmitt, R.R.

    1998-02-01

    A {open_quotes}Settlement Agreement{close_quotes} between the Department of Energy and the State of Idaho mandates that all radioactive high-level waste (HLW) now stored at the Idaho Chemical Processing Plant (ICPP) will be treated so that it is ready to be moved out of Idaho for disposal by a target date of 2035. This report investigates vitrification treatment of all ICPP calcine, including the existing and future HLW calcine resulting from calcining liquid Sodium-Bearing Waste (SBW). Currently, the SBW is stored in the tank farm at the ICPP. Vitrification of these wastes is an acceptable treatment method for complying with the Settlement Agreement. This method involves vitrifying the calcined waste and casting the vitrified mass into stainless steel canisters that will be ready to be moved out of the Idaho for disposal by 2035. These canisters will be stored at the Idaho National Engineering and Environmental Laboratory (INEEL) until they are sent to a HLW national repository. The operating period for vitrification treatment will be from 2013 through 2032; all HLW will be treated and in storage by the end of 2032.

  16. Plasma treatment of air pollution control residues.

    Science.gov (United States)

    Amutha Rani, D; Gomez, E; Boccaccini, A R; Hao, L; Deegan, D; Cheeseman, C R

    2008-01-01

    Air pollution control (APC) residues from waste incineration have been blended with silica and alumina and the mix melted using DC plasma arc technology. The chemical composition of the fully amorphous homogeneous glass formed has been determined. Waste acceptance criteria compliance leach testing demonstrates that the APC residue derived glass releases only trace levels of heavy metals (Pb (production of higher value glass-ceramic products.

  17. Steam and air plasma gasification of bituminous coal and petrocoke

    OpenAIRE

    Vladimir Messerle; Alexander Ustimenko

    2012-01-01

    This paper presents a numerical analysis and experimental investigation of two very different solid fuels, low-rank bituminous coal of 40 % ash content and petrocoke of 3 % ash content, gasification under steam and air plasma conditions with an aim of producing synthesis gas. Numerical analysis was fulfilled using the software package TERRA for equilibrium computation. Using the results of the numerical simulation, experiments on plasma steam gasification of the petrocoke and air and steam ga...

  18. Radial variation of refractive index, plasma frequency and phase velocity in laser induced air plasma

    CSIR Research Space (South Africa)

    Mathuthu, M

    2006-12-01

    Full Text Available induced air plasma to study the spatial variation of plasma parameters in the axial direction of the laser beam. In this paper, the authors report investigation on the radial variation of the refractive index, plasma frequency, and phase velocity of a...

  19. Plasma properties of laser—ablated Si target in air

    Institute of Scientific and Technical Information of China (English)

    王象泰; 许炳璋; 等

    1996-01-01

    In plasma emission spectra produced by pulsed laser ablation of Si target in air under the assumption of local thermodynamic equilibrium(LTE),the electron temperature and the electron number density are calculated.respectively,It seems that LTE is valid in early stage of the laser induced plasma evolution.

  20. Quantification of air plasma chemistry for surface disinfection

    Science.gov (United States)

    Pavlovich, Matthew J.; Clark, Douglas S.; Graves, David B.

    2014-12-01

    Atmospheric-pressure air plasmas, created by a variety of discharges, are promising sources of reactive species for the emerging field of plasma biotechnology because of their convenience and ability to operate at ambient conditions. One biological application of ambient-air plasma is microbial disinfection, and the ability of air plasmas to decontaminate both solid surfaces and liquid volumes has been thoroughly established in the literature. However, the mechanism of disinfection and which reactive species most strongly correlate with antimicrobial effects are still not well understood. We describe quantitative gas-phase measurements of plasma chemistry via infrared spectroscopy in confined volumes, focusing on air plasma generated via surface micro-discharge (SMD). Previously, it has been shown that gaseous chemistry is highly sensitive to operating conditions, and the measurements we describe here extend those findings. We quantify the gaseous concentrations of ozone (O3) and nitrogen oxides (NO and NO2, or NOx) throughout the established ‘regimes’ for SMD air plasma chemistry: the low-power, ozone-dominated mode; the high-power, nitrogen oxides-dominated mode; and the intermediate, unstable transition region. The results presented here are in good agreement with previously published experimental studies of aqueous chemistry and parameterized models of gaseous chemistry. The principal finding of the present study is the correlation of bacterial inactivation on dry surfaces with gaseous chemistry across these time and power regimes. Bacterial decontamination is most effective in ‘NOx mode’ and less effective in ‘ozone mode’, with the weakest antibacterial effects in the transition region. Our results underscore the dynamic nature of air plasma chemistry and the importance of careful chemical characterization of plasma devices intended for biological applications.

  1. Return of vitrified wastes from France to Japan; Retour des residus vitrifies de France au Japon

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-07-01

    The radioactive wastes resulting from the burnup of nuclear fuels in nuclear reactors represent 3 to 5% of the spent fuel. These wastes cannot be reused nor recycled and thus are vitrified after reprocessing. Japanese power companies have signed contracts with Cogema in France and BNFL in the UK for the reprocessing of their spent fuels. Then, the ultimate reprocessed wastes are sent back to Japan for storage. This information dossier takes stock of different questions relative to the transport of the vitrified wastes from France to Japan: why France sends back containers of vitrified wastes to Japan? What is a vitrified wastes container made of? How containers are transported? What is the regulatory frame applicable to these transports? Which safety measures are taken during transport? Which physical protection is applied? Which temporary storage facilities are used before and after transportation? How is performed the ultimate storage of wastes in Japan? Which quality and safety warranties are taken? Which emergency plans and exercises are provided? What are the applicable civil liability regimes? And what kind of information is given to the public about these transports. Some general information about energy and nuclear power worldwide, energy and environment, radioactivity, BNFL, Cogema and ORC is given in appendixes. (J.S.)

  2. Steam and air plasma gasification of bituminous coal and petrocoke

    Directory of Open Access Journals (Sweden)

    Vladimir Messerle

    2012-12-01

    Full Text Available This paper presents a numerical analysis and experimental investigation of two very different solid fuels, low-rank bituminous coal of 40 % ash content and petrocoke of 3 % ash content, gasification under steam and air plasma conditions with an aim of producing synthesis gas. Numerical analysis was fulfilled using the software package TERRA for equilibrium computation. Using the results of the numerical simulation, experiments on plasma steam gasification of the petrocoke and air and steam gasification of the coal were conducted in an original installation. Nominal power of the plasma installation is 100 kWe and sum consumption of the reagents is up to 20 kg/h. High quality synthesis gas was produced in the experiments on solid fuels plasma gasification. It has been found that the synthesis gas content at about 97.4 vol.% can be produced. Comparison between the numerical and experimental results showed satisfactory agreement. 

  3. PUPTH Prehospital Air Medical Plasma (PAMP) Trial

    Science.gov (United States)

    2014-07-01

    devices, or other support for this research ****Such as serving on the Board of Directors or Board of Managers or a position that carries a fiduciary ...requiremen rticipation in ge Scale Co l, (www.glu relationship ll (FFP:PRB .[47] We ve the FFP:P in mortality nd that des y, high FFP survival ben en...the development of nosocomial infection. There was a relationship between plasma and multiple organ failure and acute respiratory distress syndrome. A

  4. Thomson scattering from laser induced plasma in air

    Energy Technology Data Exchange (ETDEWEB)

    Dzierzega, K; Mendys, A [Institute of Physics, Jagiellonian University, ul. Reymonta 4, 30-059 Krakow (Poland); Pellerin, S; Thouin, E [GREMI - site de Bourges, Universite d' Orleans, rue Gaston Berger BP 4043, 18028 Bourges (France); Travaille, G; Bousquet, B; Canioni, L [Centre de Physique Moleculaire Optique et Hertzienne, Universite Bordeaux I, 351 Cours de la Liberation, 33405 Talence CEDEX (France); Pokrzywka, B, E-mail: krzysztof.dzierzega@uj.edu.p [Mt. Suhora Observatory, Pedagogical University of Cracow, ul. Podchorazych 2, 30-084 Krakow (Poland)

    2010-05-01

    The laser induced plasma in air produced by 6 ns, 532 nm Nd:YAG pulses with 25 mJ energy was studied using the Thomson scattering method and plasma imaging techniques. Plasma images and Thomson scattered spectra were registered at delay times ranging from 150 ns to 1 {mu}s after the breakdown pulses. The electron density and temperature, as determined in the core of the plasma plume, were found to decrease from 7.4 x 10{sup 17} cm{sup -3} to about 1.03 x 10{sup 17} cm{sup -3} and from 100 900 K to 22 700 K. The highly elevated electron temperatures are the result of plasma heating by the second, probe pulse in the Thomson scattering experiments.

  5. Air plasma treatment of liquid covered tissue: long timescale chemistry

    Science.gov (United States)

    Lietz, Amanda M.; Kushner, Mark J.

    2016-10-01

    Atmospheric pressure plasmas have shown great promise for the treatment of wounds and cancerous tumors. In these applications, the sample is usually covered by a thin layer of a biological liquid. The reactive oxygen and nitrogen species (RONS) generated by the plasma activate and are processed by the liquid before the plasma produced activation reaches the tissue. The synergy between the plasma and the liquid, including evaporation and the solvation of ions and neutrals, is critical to understanding the outcome of plasma treatment. The atmospheric pressure plasma sources used in these procedures are typically repetitively pulsed. The processes activated by the plasma sources have multiple timescales—from a few ns during the discharge pulse to many minutes for reactions in the liquid. In this paper we discuss results from a computational investigation of plasma-liquid interactions and liquid phase chemistry using a global model with the goal of addressing this large dynamic range in timescales. In modeling air plasmas produced by a dielectric barrier discharge over liquid covered tissue, 5000 voltage pulses were simulated, followed by 5 min of afterglow. Due to the accumulation of long-lived species such as ozone and N x O y , the gas phase dynamics of the 5000th discharge pulse are different from those of the first pulse, particularly with regards to the negative ions. The consequences of applied voltage, gas flow, pulse repetition frequency, and the presence of organic molecules in the liquid on the gas and liquid reactive species are discussed.

  6. Generation of low-temperature air plasma for food processing

    Science.gov (United States)

    Stepanova, Olga; Demidova, Maria; Astafiev, Alexander; Pinchuk, Mikhail; Balkir, Pinar; Turantas, Fulya

    2015-11-01

    The project is aimed at developing a physical and technical foundation of generating plasma with low gas temperature at atmospheric pressure for food industry needs. As known, plasma has an antimicrobial effect on the numerous types of microorganisms, including those that cause food spoilage. In this work an original experimental setup has been developed for the treatment of different foods. It is based on initiating corona or dielectric-barrier discharge in a chamber filled with ambient air in combination with a certain helium admixture. The experimental setup provides various conditions of discharge generation (including discharge gap geometry, supply voltage, velocity of gas flow, content of helium admixture in air and working pressure) and allows for the measurement of the electrical discharge parameters. Some recommendations on choosing optimal conditions of discharge generation for experiments on plasma food processing are developed.

  7. Pure air-plasma bullets propagating inside microcapillaries and in ambient air

    KAUST Repository

    Lacoste, Deanna

    2014-11-04

    This paper reports on the characterization of air-plasma bullets in microcapillary tubes and in ambient air, obtained without the use of inert or noble gases. The bullets were produced by nanosecond repetitively pulsed discharges, applied in a dielectric barrier discharge configuration. The anode was a tungsten wire with a diameter of 50 μm, centered in the microcapillary, while the cathode was a silver ring, fixed on the outer surface of the fused silica tube. The effects of the applied voltage and the inner diameter of the microcapillary tube on the plasma behavior were investigated. Inside the tubes, while the topology of the bullets seems to be strongly dependent on the diameter, their velocity is only a function of the amplitude of the applied voltage. In ambient air, the propagation of air bullets with a velocity of about 1.25 ×105 m s-1 is observed.

  8. Pure air-plasma bullets propagating inside microcapillaries and in ambient air

    Science.gov (United States)

    Lacoste, Deanna A.; Bourdon, Anne; Kuribara, Koichi; Urabe, Keiichiro; Stauss, Sven; Terashima, Kazuo

    2014-12-01

    This paper reports on the characterization of air-plasma bullets in microcapillary tubes and in ambient air, obtained without the use of inert or noble gases. The bullets were produced by nanosecond repetitively pulsed discharges, applied in a dielectric barrier discharge configuration. The anode was a tungsten wire with a diameter of 50 µm, centered in the microcapillary, while the cathode was a silver ring, fixed on the outer surface of the fused silica tube. The effects of the applied voltage and the inner diameter of the microcapillary tube on the plasma behavior were investigated. Inside the tubes, while the topology of the bullets seems to be strongly dependent on the diameter, their velocity is only a function of the amplitude of the applied voltage. In ambient air, the propagation of air bullets with a velocity of about 1.25 × 105 m s-1 is observed.

  9. Inactivation of the biofilm by the air plasma containing water

    Science.gov (United States)

    Suganuma, Ryota; Yasuoka, Koichi; Yasuoka Takeuchi lab Team

    2014-10-01

    Biofilms are caused by environmental degradation in food factory and medical facilities. Inactivation of biofilm has the method of making it react to chemicals including chlorine, hydrogen peroxide, and ozone. Although inactivation by chemicals has the problem that hazardous property of a residual substance and hydrogen peroxide have slow reaction velocity. We achieved advanced oxidation process (AOP) with air plasma. Hydrogen peroxide and ozone, which were used for the formation of OH radicals in our experiment, were able to be generated selectively by adjusting the amount of water supplied to the plasma. We inactivated Pseudomonas aeruginosa biofilm in five minutes with OH radicals generated by using hydrogen peroxide and ozone.

  10. Effect of ZnO on the interfacial bonding between Na 2O-B 2O 3-SiO 2 vitrified bond and diamond

    Science.gov (United States)

    Wang, P. F.; Li, Zh. H.; Li, J.; Zhu, Y. M.

    2009-08-01

    Diamond composites were prepared by sintering diamond grains with low melting Na 2O-B 2O 3-SiO 2 vitrified bonds in air. The influence of ZnO on the wettability and flowing ability of Na 2O-B 2O 3-SiO 2 vitrified bonds was characterized by wetting angle, the interfacial bonding states between diamond grains and the vitrified bonds were observed by scanning electron microscope (SEM), and the micro-scale bonding mechanism in the interfaces was investigated by means of energy-dispersive spectrometer (EDS), Fourier transform infrared (FTIR) spectrometer and X-ray photoelectron spectroscopy (XPS). The experimental results showed that ZnO facilitated the dissociation of boron/silicon-oxygen polyhedra and the formation of larger amount of non-bridging oxygen in the glass network, which resulted in the increase of the vitrified bonds' wettability and the formation of -C dbnd O, -O-H and -C-H bonds on the surface of diamond grains. B and Si diffused from the vitrified bonds to the interface, and C-C, C-O, C dbnd O and C-B bond formed on the surface of sintered diamond grains during sintering process, by which the interfacial bonding between diamond grains and the vitrified bonds was strengthened.

  11. Nanostructured yttria stabilized zirconia coatings deposited by air plasma spraying

    Institute of Scientific and Technical Information of China (English)

    ZHOU Hong; LI Fei; HE Bo; WANG Jun; SUN Bao-de

    2007-01-01

    Nanostructured yttria partially stabilized zirconia coatings were deposited by air plasma spraying with reconstituted nanosized powder. The microstructures and phase compositions of the powder and the as-sprayed nanostructured coatings were characterized by transmission electron microscopy(TEM), scanning electron microscopy(SEM) and X-ray diffraction(XRD). The results demonstrate that the microstructure of as-sprayed nanostructured zirconia coating exhibits a unique tri-modal distribution including the initial nanostructure of the powder, equiaxed grains and columnar grains. Air plasma sprayed nanostructured zirconia coatings consist of only the nontransformable tetragonal phase, though the reconstituted nanostructured powder shows the presence of the monoclinic, the tetragonal and the cubic phases. The mean grain size of the coating is about 42 nm.

  12. Thermodynamic diagrams for high temperature plasmas of air, air-carbon, carbon-hydrogen mixtures, and argon

    CERN Document Server

    Kroepelin, H; Hoffmann, K-U

    2013-01-01

    Thermodynamic Diagrams for High Temperature Plasmas of Air, Air-Carbon, Carbon-Hydrogen Mixtures, and Argon provides information relating to the properties of equilibrium gas plasmas formed from hydrocarbons, from air without argon, from pure argon, and from mixtures of air and carbon at various compositions, temperatures and pressures. The data are presented in graphical rather than tabular form to provide a clearer picture of the plasma processes investigated. This book is composed of four chapters, and begins with the introduction to the characteristics of plasmas, with emphasis on their th

  13. Air trichloroethylene oxidation in a corona plasma-catalytic reactor

    Science.gov (United States)

    Masoomi-Godarzi, S.; Ranji-Burachaloo, H.; Khodadadi, A. A.; Vesali-Naseh, M.; Mortazavi, Y.

    2014-08-01

    The oxidative decomposition of trichloroethylene (TCE; 300 ppm) by non-thermal corona plasma was investigated in dry air at atmospheric pressure and room temperature, both in the absence and presence of catalysts including MnOx, CoOx. The catalysts were synthesized by a co-precipitation method. The morphology and structure of the catalysts were characterized by BET surface area measurement and Fourier Transform Infrared (FTIR) methods. Decomposition of TCE and distribution of products were evaluated by a gas chromatograph (GC) and an FTIR. In the absence of the catalyst, TCE removal is increased with increases in the applied voltage and current intensity. Higher TCE removal and CO2 selectivity is observed in presence of the corona and catalysts, as compared to those with the plasma alone. The results show that MnOx and CoOx catalysts can dissociate the in-plasma produced ozone to oxygen radicals, which enhances the TCE decomposition.

  14. Observations of Microwave Continuum Emission from Air Shower Plasmas

    CERN Document Server

    Gorham, P W; Varner, G S; Beatty, J J; Connolly, A; Chen, P; Conde, M E; Gai, W; Hast, C; Hebert, C L; Miki, C; Konecny, R; Kowalski, J; Ng, J; Power, J G; Reil, K; Saltzberg, D; Stokes, B T; Walz, D

    2007-01-01

    We investigate a possible new technique for microwave measurements of ultra-high energy cosmic ray (UHECR) extensive air showers which relies on detection of expected continuum radiation in the microwave range, caused by free-electron collisions with neutrals in the tenuous plasma left after the passage of the shower. We performed an initial experiment at the AWA (Argonne Wakefield Accelerator) laboratory in 2003 and measured broadband microwave emission from air ionized via high energy electrons and photons. A follow-up experiment at SLAC (Stanford Linear Accelerator Center) in summer of 2004 confirmed the major features of the previous AWA observations with better precision and made additional measurements relevant to the calorimetric capabilities of the method. Prompted by these results we built a prototype detector using satellite television technology, and have made measurements indicating possible detection of cosmic ray extensive air showers. The method, if confirmed by experiments now in progress, cou...

  15. A handheld low temperature atmospheric pressure air plasma gun for nanomaterial synthesis in liquid phase

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Shuang; Wang, Kaile; Zuo, Shasha; Liu, Jiahui [Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); Zhang, Jue, E-mail: zhangjue@pku.edu.cn; Fang, Jing [Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); College of Engineering, Peking University, Beijing 100871 (China)

    2015-10-15

    A handheld low temperature atmospheric pressure air plasma gun based on a dielectric barrier structure with hollow electrodes was proposed. The portable plasma gun with an embedded mini air pump was driven by a 12 V direct voltage battery. The air plasma jet generated from the gun could be touched without a common shock hazard. Besides working in air, the plasma gun can also work in water. The diagnostic result of optical emission spectroscopy showed the difference in reactive species of air plasma jet between in air and in water. The plasma gun was excited in 20 ml chloroauric acid aqueous solution with a concentration of 1.214 mM. A significant amount of gold nanoparticles were synthesized after 2 min continuous discharge. The plasma gun with these unique features is applicable in plasma medicine, etching, and s-nthesis of nanomaterials.

  16. Return of the vitrified residues of France to Germany; Retour des residus vitrifies de France en Allemagne

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-07-01

    The return of the vitrified residues from France to Germany fits into framework of the spent fuels reprocessing contracts, signed between COGEMA and german electric power companies. These contracts preconize the return in the origin country of the ultimate wastes after their processing and conditioning. This document proposes nine information cards on this topic: why France returns vitrified residues in Germany; what is a vitrified residues container; the quality and the safety control; the containers transportation; the regulatory framework applied to these transports; the interim storage before and after the transport; the final disposal of vitrified residues in Germany; concerned societies, experts and authorities; the risks bound to the radiation exposure during the transport. (A.L.B.)

  17. Monte Carlo simulation of electron beam air plasma characteristics

    Institute of Scientific and Technical Information of China (English)

    Deng Yong-Feng; Han Xian-Wei; Tan Chang

    2009-01-01

    A high-energy electron beam generator is used to generate a plasma in atmosphere. Based on a Monte Carlo toolkit named GEANT4,a model including complete physics processes is established to simulate the passage of the electron beam in air. Based on the model,the characteristics of the electron beam air plasma are calculated. The energy distribution of beam electrons (BEs) indicates that high-energy electrons almost reside in the centre region of the beam,but low-energy electrons always live in the fringe area. The energy deposition is calculated in two cases,i.e.,with and without secondary electrons (SEs). Analysis indicates that the energy deposition of Ses accounts for a large part of the total energy deposition. The results of the energy spectrum show that the electrons in the inlet layer of the low-pressure chamber (LPC) are monoenergetic,but the energy spectrum of the electrons in the outlet layer is not pure. The SEs are largely generated at the outlet of the LPC. Moreover,both the energy distribution of Bes and the magnitude of the density of SEs are closely related to the pressure of LPC. Thus,a conclusion is drawn that a low magnitude of LPC pressure is helpful for reducing the energy loss in the LPC and also useful for greatly increasing the secondary electron density in dense air.

  18. Surface modification of PE film by DBD plasma in air

    Energy Technology Data Exchange (ETDEWEB)

    Ren, C.-S. [State Key Laboratory of Material Modification by Electron, Ion and Laser Beams, Dalian University of Technology, Dalian 116023 (China)], E-mail: rchsh@dlut.edu.cn; Wang, K.; Nie, Q.-Y.; Wang, D.-Z.; Guo, S.-H. [State Key Laboratory of Material Modification by Electron, Ion and Laser Beams, Dalian University of Technology, Dalian 116023 (China)

    2008-12-30

    In this paper, surface modification of polyethylene (PE) films is studied by dielectric barrier discharge plasma treatment in air. The treated samples were examined by water contact angle measurement, calculation of surface free energy, Fourier transform infrared attenuated total reflection spectroscopy (FTIR-ATR), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). The water contact angle changes from the original value of 93.2{sup o} to the minimum value of 53.3{sup o} and surface free energy increases from 27.3 to 51.89 J/m{sup 2} after treatment time of 50 s. Both ATR and XPS show some oxidized species are introduced into the sample surface by the plasma treatment and that the change tendencies of the water contact angle and surface free energy with the treatment time are the same as that of the oxygen concentration on the treated sample surface. Cu films were deposited on the treated and untreated PE surfaces. The peel adhesive strength between the Cu film and the treated sample is 1.5 MPa, whereas the value is only 0.8 MPa between the Cu film and the untreated PE. SEM pictures show that the Cu film deposited on the plasma treated PE surface is smooth and the crystal grain is smaller, contrarily the Cu film on the untreated PE surface is rough and the crystal grain is larger.

  19. Theoretical Computation for Non-Equilibrium Air Plasma Electrical Conductivity at Atmospheric Pressure

    Institute of Scientific and Technical Information of China (English)

    HAN Dong; GUO Wen-Kang; XU Ping; LIANG Rong-Qing

    2007-01-01

    @@ Based on the Chapman-Enskog theory, we calculate the electrical conductivity of non-equilibrium air plasma in the two-temperature model. We consider different degrees of non-equilibrium, which is defined by the ratio of electronic temperature to heavy particles temperature. The method of computing the composition of air plasma is demonstrated. After calculating the electrical conductivity from electron temperature 1000 K to 15000K, the present result is compared with Murphy's study [Plasma Chem. Plasma Process 15 (1994) 279] for equilibrium case. All the calculation is completed at atmospheric pressure. The present results may have potential applications in numerical calculation of non-equilibrium air plasma.

  20. Vitrified chemically bonded phosphate ceramics for immobilization of radioisotopes

    Science.gov (United States)

    Wagh, Arun S.

    2016-04-05

    A method of immobilizing a radioisotope and vitrified chemically bonded phosphate ceramic (CBPC) articles formed by the method are described. The method comprises combining a radioisotope-containing material, MgO, a source of phosphate, and optionally, a reducing agent, in water at a temperature of less than 100.degree. C. to form a slurry; curing the slurry to form a solid intermediate CBPC article comprising the radioisotope therefrom; comminuting the intermediate CBPC article, mixing the comminuted material with glass frits, and heating the mixture at a temperature in the range of about 900 to about 1500.degree. C. to form a vitrified CBPC article comprising the radioisotope immobilized therein.

  1. Transfer of microwave energy along a filament plasma column in air

    Science.gov (United States)

    Prade, B.; Houard, A.; Larour, J.; Pellet, M.; Mysyrowicz, A.

    2017-01-01

    We demonstrate the coupling of microwave radiation into a plasma channel formed by laser filamentation in air, leading to the amplification by two orders of magnitude of longitudinal oscillations of the plasma. Transfer of this longitudinal excitation toward unexcited region of the plasma column occurs over >10 cm, in good agreement with a theoretical model describing the propagation of a TM wave guided along the surface between air and plasma. We foresee that high-power low-frequency electromagnetic waves injected into a multi-filament plasma could initiate and sustain a long-lived plasma over several meters distance.

  2. Air plasma kinetics under the influence of sprites

    Science.gov (United States)

    Gordillo-Vázquez, F. J.

    2008-12-01

    A full time-dependent kinetic study is presented for the main microscopic collisional and radiative processes underlying the optical flashes associated with an impulsive (τ = 5 µs) discharge in the form of a single sprite streamer passing through an air region of the mesosphere at three different altitudes (63, 68 and 78 km). The kinetic formalism developed includes the coupling of the rate equations of each of the different species considered (electrons, ions, atoms and molecules) with the Boltzmann transport equation so that, in this way, all the kinetics is self-consistent, although, in the present approach, the electrodynamics (no Poisson equation is considered) is not coupled. The chemical model set up for air plasmas includes more than 75 species and almost 500 reactions. In addition, a complete set of reactions (more than 110) has been considered to take into account the possible impact of including H2O (humid chemistry) in the generated air plasmas. This study also considers the vibrational kinetics of N2 and CO2 and explicitly evaluates the optical emissions associated with a number of excited states of N2, O2, O in the visible, CO2 in the infrared (IR) and ultraviolet (UV) emissions of sprite streamers due to the N2 Lyman-Birge-Hopfield (LBH) and the NO-γ band systems. All the calculations are conducted for midnight conditions in mid-latitude regions (+38°N) and 0° longitude, using as initial values for the neutral species those provided by the latest version of the Whole Atmosphere Community Climate Model (WACCM). According to our calculations, the impact of 4 ppm of H2O is only slightly visible in O_{3}^{-} at 68 and 78 km while it strongly affects the behaviour of the anion CO_{4}^{-} at all the altitudes investigated. The local enhancement of NOx predicted by the present model varies with the altitude. At 68 km, the concentrations of NO and NO2 increase by about one order of magnitude while that of NO3 exhibits a remarkable growth of up to almost

  3. Asphaltene Erosion Process in Air Plasma: Emission Spectroscopy and Surface Analysis for Air-Plasma Reactions

    Institute of Scientific and Technical Information of China (English)

    H. MARTINEZ; O. FLORES; J. C. POVEDA; B. CAMPILLO

    2012-01-01

    Optical emission spectroscopy (OES) was applied for plasma characterization during the erosion of asphaltene substrates. An amount of 100 mg of asphaltene was carefully applied to an electrode and exposed to air-plasma glow discharge at a pressure of 1.0 Torr. The plasma was generated in a stainless steel discharge chamber by an ac generator at a frequency of 60 Hz, output power of 50 W and a gas flow rate of 1.8 L/min. The electron temperature and ion density were estimated to be 2.15±0.11 eV and (1.24±0.05)× 10^16 m^-3, respectively, using a double Langmuir probe. OES was employed to observe the emission from the asphaltene exposed to air plasma. Both molecular band emission from N2, N2+, OH, CH, NH, O2 as well as CN, and atomic light emission from V and Hγ were observed and used to monitor the evolution of asphaltene erosion. The asphaltene erosion was analyzed with the aid of a scanning electron microscope (SEM) equipped with an energy dispersive X-ray (EDX) detector. The EDX analysis showed that the time evolution of elements C, O, S and V were similar and the chemical composition of the exposed asphaltenes remained constant. Particle size evolution was measured, showing a maximum size of 2307 μm after 60 min. This behavior is most likely related to particle agglomeration as a function of time.

  4. Effect of microwave frequency on plasma formation in air breakdown at atmospheric pressure

    Institute of Scientific and Technical Information of China (English)

    赵朋程; 郭立新; 李慧敏

    2015-01-01

    Microwave breakdown at atmospheric pressure causes the formation of a discrete plasma structure. The one-dimensional fluid model coupling Maxwell equations with plasma fluid equations is used to study the effect of the mi-crowave frequency on the formation of air plasma. Simulation results show that, the filamentary plasma array propagating toward the microwave source is formed at different microwave frequencies. As the microwave frequency decreases, the ratio of the distance between two adjacent plasma filaments to the corresponding wavelength remains almost unchanged (on the order of 1/4), while the plasma front propagates more slowly due to the increase in the formation time of the new plasma filament.

  5. Degradation of volatile organic compounds in a non-thermal plasma air purifier.

    Science.gov (United States)

    Schmid, Stefan; Jecklin, Matthias C; Zenobi, Renato

    2010-03-01

    The degradation of volatile organic compounds in a commercially available non-thermal plasma based air purifying system was investigated. Several studies exist that interrogate the degradation of VOCs in closed air systems using a non-thermal plasma combined with a heterogeneous catalyst. For the first time, however, our study was performed under realistic conditions (normal indoor air, 297.5K and 12.5 g m(-3) water content) on an open system, in the absence of an auxiliary catalyst, and using standard operating air flow rates (up to 320 L min(-1)). Cyclohexene, benzene, toluene, ethylbenzene and the xylene isomers were nebulized and guided through the plasma air purifier. The degradation products were trapped by activated charcoal tubes or silica gel tubes, and analyzed using gas chromatography mass spectrometry. Degradation efficiencies of 11+/-1.6% for cyclohexene, air purifier.

  6. Broadband and long lifetime plasma-antenna in air initiated by laser-guided discharge

    Science.gov (United States)

    Théberge, Francis; Gravel, Jean-François; Kieffer, Jean-Claude; Vidal, François; Châteauneuf, Marc

    2017-08-01

    In this work, we demonstrate the coupling and emission of radio-frequency (RF) signals from laser-guided discharge in ambient air. The produced 100-cm long plasma-antenna is broadband and can emit RF signals for more than 2 ms, which corresponds to an enhancement of the plasma-antenna lifetime of 4 orders of magnitude relative to previous demonstrations using laser-based plasma filamentation. The generation of large diameter plasma-antennas in the air allows to broadcast RF signals efficiently from ˜10 MHz to few tens of GHz.

  7. Electron properties and air mixing in radio frequency driven argon plasma jets at atmospheric pressure

    Energy Technology Data Exchange (ETDEWEB)

    Gessel, Bram van; Bruggeman, Peter [Department of Applied Physics, Eindhoven University of Technology, PO Box 513, 5600 MB Eindhoven (Netherlands); Brandenburg, Ronny [Department of Applied Physics, Eindhoven University of Technology, PO Box 513, 5600 MB Eindhoven (Netherlands); Leibniz Institute for Plasma Science and Technology (INP Greifswald), Felix-Hausdorff-Str. 2, D-17489 Greifswald (Germany)

    2013-08-05

    A time modulated radio frequency (RF) plasma jet operated with an Ar mixture is investigated by measuring the electron density and electron temperature using Thomson scattering. The measurements have been performed spatially resolved for two different electrode configurations and as a function of the plasma dissipated power and air concentration admixed to the Ar. Time resolved measurements of electron densities and temperatures during the RF cycle and after plasma power switch-off are presented. Furthermore, the influence of the plasma on the air entrainment into the effluent is studied using Raman scattering.

  8. An investigation of an underwater steam plasma discharge as alternative to air plasmas for water purification

    Science.gov (United States)

    Gucker, Sarah N.; Foster, John E.; Garcia, Maria C.

    2015-10-01

    An underwater steam plasma discharge, in which water itself is the ionizing media, is investigated as a means to introduce advanced oxidation species into contaminated water for the purpose of water purification. The steam discharge avoids the acidification observed with air discharges and also avoids the need for a feed gas, simplifying the system. Steam discharge operation did not result in a pH changes in the processing of water or simulated wastewater, with the actual pH remaining roughly constant during processing. Simulated wastewater has been shown to continue to decompose significantly after steam treatment, suggesting the presence of long-lived plasma produced radicals. During steam discharge operation, nitrate production is limited, and nitrite production was found to be below the detection threshold of (roughly 0.2 mg L-1). The discharge was operated over a broad range of deposited power levels, ranging from approximately 30 W to 300 W. Hydrogen peroxide production was found to scale with increasing power. Additionally, the hydrogen peroxide production efficiency of the discharge was found to be higher than many of the rates reported in the literature to date.

  9. Acoustic Diagnostics of Plasma Channels Induced by Intense Femtosecond Laser Pulses in Air

    Institute of Scientific and Technical Information of China (English)

    HAO Zuo-Qiang; WEI Zhi-Yi; YU Jin; ZHANG Jie; LI Yu-Tong; YUAN Xiao-Hui; ZHENG Zhi-Yuan; WANG Peng; WANG Zhao-Hua; LING Wei-Jun

    2005-01-01

    @@ Long plasma channels induced by femtosecond laser pulses in air are diagnosed using the sonographic method. By detecting the sound signals along the channels, the length and the electron density of the channels are measured.

  10. Sterilization effect of atmospheric pressure non-thermal air plasma on dental instruments

    National Research Council Canada - National Science Library

    Sung, Su-Jin; Huh, Jung-Bo; Yun, Mi-Jung; Chang, Brian Myung W; Jeong, Chang-Mo; Jeon, Young-Chan

    2013-01-01

    .... To develop a dental sterilizer which can sterilize most materials, such as metals, rubbers, and plastics, the sterilization effect of an atmospheric pressure non-thermal air plasma device was evaluated...

  11. Air plasma waveguide using pico-sec and nano-sec laser pulses

    Science.gov (United States)

    Pandey, Pramod K.; Gupta, Shyam L.; Narayanan, V.; Thareja, Raj K.

    2012-02-01

    We report a shock driven plasma in air breakdown using pump-probe to elucidate the hydrodynamic evolution of air plasma waveguide. Imaging of the evolution of air plasma plume is used to investigate the pump pulse effect on the plume dynamic. Imaging of the channeled pulse through evolved waveguide shows five time enhancement in Rayleigh length at 7 ns delay of probe pulse with respect to pump pulse. The evolved channel radius rch≈37μm has been shown to couple the maximum energy of the probe pulse yielding the electron density difference Δne~1018cm-3 between axis and periphery of the channel. The air plasma wave guide is shown to support the fundamental mode at optimum delay.

  12. Studying the fate of non-volatile organic compounds in a commercial plasma air purifier

    Energy Technology Data Exchange (ETDEWEB)

    Schmid, Stefan [ETH Zürich, Department of Chemistry and Applied Biosciences, CH-8093 Zürich (Switzerland); Seiler, Cornelia; Gerecke, Andreas C. [Swiss Federal Laboratories for Material Science and Technology (EMPA), CH-8600 Dübendorf (Switzerland); Hächler, Herbert [University of Zürich, Institute for Food Safety and Hygiene, National Centre for Enteropathogenic Bacteria and Listeria (NENT), CH-8057 Zürich (Switzerland); Hilbi, Hubert [Ludwig-Maximilians-Universität München Max von Pettenkofer-Institut, D-80336 München (Germany); Frey, Joachim [University of Bern, Institute for Veterinary Bacteriology, CH-3001 Bern (Switzerland); Weidmann, Simon; Meier, Lukas; Berchtold, Christian [ETH Zürich, Department of Chemistry and Applied Biosciences, CH-8093 Zürich (Switzerland); Zenobi, Renato, E-mail: zenobi@org.chem.ethz.ch [ETH Zürich, Department of Chemistry and Applied Biosciences, CH-8093 Zürich (Switzerland)

    2013-07-15

    Highlights: • Degradation of environmental toxins, a protein, and bioparticles were studied. • A commercial air purifier based on a cold plasma was used. • Passage through the device reduced the concentration of the compounds/particles. • Deposition inside the plasma air purifier was the main removal process. -- Abstract: Degradation of non-volatile organic compounds–environmental toxins (methyltriclosane and phenanthrene), bovine serum albumin, as well as bioparticles (Legionella pneumophila, Bacillus subtilis, and Bacillus anthracis)–in a commercially available plasma air purifier based on a cold plasma was studied in detail, focusing on its efficiency and on the resulting degradation products. This system is capable of handling air flow velocities of up to 3.0 m s{sup −1} (3200 L min{sup −1}), much higher than other plasma-based reactors described in the literature, which generally are limited to air flow rates below 10 L min{sup −1}. Mass balance studies consistently indicated a reduction in concentration of the compounds/particles after passage through the plasma air purifier, 31% for phenanthrene, 17% for methyltriclosane, and 80% for bovine serum albumin. L. pneumophila did not survive passage through the plasma air purifier, and cell counts of aerosolized spores of B. subtilis and B. anthracis were reduced by 26- and 15-fold, depending on whether it was run at 10 Hz or 50 Hz, respectively. However rather than chemical degradation, deposition on the inner surfaces of the plasma air purifier occured. Our interpretation is that putative “degradation” efficiencies were largely due to electrostatic precipitation rather than to decomposition into smaller molecules.

  13. Novel fragmentation model for pulverized coal particles gasification in low temperature air thermal plasma

    OpenAIRE

    Jovanović Rastko D.; Cvetinović Dejan B.; Stefanović Predrag Lj.; Škobalj Predrag D.; Marković Zoran J.

    2016-01-01

    New system for start-up and flame support based on coal gasification by low temperature air thermal plasma is planned to supplement current heavy oil system in Serbian thermal power plants in order to decrease air pollutions emission and operational costs. Locally introduced plasma thermal energy heats up and ignites entrained coal particles, thus starting chain process which releases heat energy from gasified coal particles inside burner channel. Important...

  14. Experimental studies on removal of airborne haloanisoles by non-thermal plasma air purifiers

    DEFF Research Database (Denmark)

    Fang, Lei; Hallam, David; Bermúdez, Raúl

    2016-01-01

    A laboratory study was conducted to test the performance of non-thermal plasma air purifiers on its removal effectiveness of two haloanisoles – 2,4,6-trichloroanisole (TCA) and 2,4,6-Tribromoanisole (TBA). TCA and TBA are the two major compounds found in wine cellars that can contaminate wine...... to produce unpalatable mouldy and musty tastes. The test was first conducted in a climate chamber. The plasma air purifier was installed in a test rig developed for the testing and challenged by airflow with certain concentrations of TCA and TBA. Air samples upstream and downstream of the air purifier...... was collected by Tenax tubes and the concentration of TCA and TBA were analyzed by thermal desorption GC–MS. The results showed that the plasma air purifier was effective on removing TCA and TBA with a single pass efficiency of better than 82%. The effect was further validated in a wine cellar under a realistic...

  15. Peculiarities of Efficient Plasma Generation in Air and Water by Short Duration Laser Pulses

    Science.gov (United States)

    Adamovsky, Grigory; Floyd, Bertram M.

    2017-01-01

    We have conducted experiments to demonstrate an efficient generation of plasma discharges by focused nanosecond pulsed laser beams in air and provided recommendations on the design of optical systems to implement such plasma generation. We have also demonstrated generation of the secondary plasma discharge using the unused energy from the primary one. Focused nanosecond pulsed laser beams have also been utilized to generate plasma in water where we observed self-focusing and filamentation. Furthermore, we applied the laser generated plasma to the decomposition of methylene blue dye diluted in water.

  16. Broadband field-resolved terahertz detection via laser induced air plasma with controlled optical bias.

    Science.gov (United States)

    Li, Chia-Yeh; Seletskiy, Denis V; Yang, Zhou; Sheik-Bahae, Mansoor

    2015-05-04

    We report a robust method of coherent detection of broadband THz pulses using terahertz induced second-harmonic (TISH) generation in a laser induced air plasma together with a controlled second harmonic optical bias. We discuss a role of the bias field and its phase in the process of coherent detection. Phase-matching considerations subject to plasma dispersion are also examined.

  17. Targeting cancer cells with reactive oxygen and nitrogen species generated by atmospheric-pressure air plasma.

    Directory of Open Access Journals (Sweden)

    Hak Jun Ahn

    Full Text Available The plasma jet has been proposed as a novel therapeutic method for cancer. Anticancer activity of plasma has been reported to involve mitochondrial dysfunction. However, what constituents generated by plasma is linked to this anticancer process and its mechanism of action remain unclear. Here, we report that the therapeutic effects of air plasma result from generation of reactive oxygen/nitrogen species (ROS/RNS including H2O2, Ox, OH-, •O2, NOx, leading to depolarization of mitochondrial membrane potential and mitochondrial ROS accumulation. Simultaneously, ROS/RNS activate c-Jun NH2-terminal kinase (JNK and p38 kinase. As a consequence, treatment with air plasma jets induces apoptotic death in human cervical cancer HeLa cells. Pretreatment of the cells with antioxidants, JNK and p38 inhibitors, or JNK and p38 siRNA abrogates the depolarization of mitochondrial membrane potential and impairs the air plasma-induced apoptotic cell death, suggesting that the ROS/RNS generated by plasma trigger signaling pathways involving JNK and p38 and promote mitochondrial perturbation, leading to apoptosis. Therefore, administration of air plasma may be a feasible strategy to eliminate cancer cells.

  18. Characterization of an atmospheric pressure air plasma source for polymer surface modification

    Science.gov (United States)

    Yang, Shujun; Tang, Jiansheng

    2013-10-01

    An atmospheric pressure air plasma source was generated through dielectric barrier discharge (DBD). It was used to modify polyethyleneterephthalate (PET) surfaces with very high throughput. An equivalent circuit model was used to calculate the peak average electron density. The emission spectrum from the plasma was taken and the main peaks in the spectrum were identified. The ozone density in the down plasma region was estimated by Absorption Spectroscopy. NSF and ARC-ODU

  19. Water treatment by the AC gliding arc air plasma

    Science.gov (United States)

    Gharagozalian, Mehrnaz; Dorranian, Davoud; Ghoranneviss, Mahmood

    2017-06-01

    In this study, the effects of gliding arc (G Arc) plasma system on the treatment of water have been investigated experimentally. An AC power supply of 15 kV potential difference at 50 Hz frequency was employed to generate plasma. Plasma density and temperature were measured using spectroscopic method. The water was contaminated with staphylococcus aureus (Gram-positive) and salmonella bacteria (Gram-negative), and Penicillium (mold fungus) individually. pH, hydrogen peroxide, and nitride contents of treated water were measured after plasma treatment. Decontamination of treated water was determined using colony counting method. Results indicate that G Arc plasma is a powerful and green tool to decontaminate water without producing any byproducts.

  20. Experimental Study on Indoor Air Cleaning Technique of Nano-Titania Catalysis Under Plasma Discharge

    Institute of Scientific and Technical Information of China (English)

    GAO Deli; YANG Xuechang; ZHOU Fei; WU Yuhuang

    2008-01-01

    In this study, a new technique of air cleaning by plasma combined with catalyst was proposed, which consisted of electrostatic precipitation, volatile organic compounds (VOCs) decomposition and sterilization. A novel indoor air purifier based on this technique was adopted. The experimental results showed that formaldehyde decomposition by the plasma-catalyst hybrid system was more efficient than that by plasma only. Positive discharge was better than negative discharge in formaldehyde removal. Meanwhile, the outlet concentration of ozone byproduct was effectively reduced by the nano-titania catalyst.

  1. Atmospheric pressure resistive barrier air plasma jet induced bacterial inactivation in aqueous environment

    Science.gov (United States)

    Thiyagarajan, Magesh; Sarani, Abdollah; Gonzales, Xavier

    2013-03-01

    An atmospheric pressure resistive barrier air plasma jet is designed to inactivate bacteria in aqueous media in direct and indirect exposure modes of treatment. The resistive barrier plasma jet is designed to operate at both dc and standard 50-60 Hz low frequency ac power input and the ambient air at 50% humidity level was used as the operating gas. The voltage-current characteristics of the plasma jet were analyzed and the operating frequency of the discharge was measured to be 20 kHz and the plasma power was measured to be 26 W. The plasma jet rotational temperatures (Trot) are obtained from the optical emission spectra, from the N2C-B(2+) transitions by matching the experimental spectrum results with the Spectra Air (SPECAIR) simulation spectra. The reactive oxygen and nitrogen species were measured using optical emission spectroscopy and gas analyzers, for direct and indirect treatment modes. The nitric oxides (NO) were observed to be the predominant long lived reactive nitrogen species produced by the plasma. Three different bacteria including Staphylococcus aureus (Gram-positive), Escherichia coli (Gram-negative), and Neisseria meningitidis (Gram-negative) were suspended in an aqueous media and treated by the resistive barrier air plasma jet in direct and indirect exposure modes. The results show that a near complete bacterial inactivation was achieved within 120 s for both direct and indirect plasma treatment of S. aureus and E. coli bacteria. Conversely, a partial inactivation of N. meningitidis was observed by 120 s direct plasma exposure and insignificant inactivation was observed for the indirect plasma exposure treatment. Plasma induced shifts in N. meningitidis gene expression was analyzed using pilC gene expression as a representative gene and the results showed a reduction in the expression of the pilC gene compared to untreated samples suggesting that the observed protection against NO may be regulated by other genes.

  2. Plasma test on industrial diamond powder in hydrogen and air for fracture strength study

    Science.gov (United States)

    Chary, Rohit Asuri Sudharshana

    Diamonds are the most precious material all over the world. Ever since their discovery, the desire for natural diamonds has been great; recently, the demand has steeply increased, leading to scarcity. For example, in 2010, diamonds worth $50 billion were marketed. This increased demand has led to discovering alternative sources to replace diamonds. The diamond, being the hardest material on earth, could be replaced with no other material except another diamond. Thus, the industrial or synthetic diamond was invented. Because of extreme hardness is one of diamond's properties, diamonds are used in cutting operations. The fracture strength of diamond is one of the crucial factors that determine its life time as a cutting tool. Glow discharge is one of the techniques used for plasma formation. The glow discharge process is conducted in a vacuum chamber by ionizing gas atoms. Ions penetrate into the atomic structure, ejecting a secondary electron. The objective of this study is to determine the change in fracture strength of industrial diamond powder before and after plasma treatment. This study focuses mainly on the change in crystal defects and crushing strength (CS) of industrial diamond powder after the penetration of hydrogen gas, air and hydrogen-air mixture ions into the sample powder. For this study, an industrial diamond powder sample of 100 carats weight, along with its average fracture strength value was received from Engis Corporation, Illinois. The sample was divided into parts, each weighing 10-12 carats. At the University of Nevada, Las Vegas (UNLV), a plasma test was conducted on six sample parts for a total of 16 hours on each part. The three gas types mentioned above were used during plasma tests, with the pressure in vacuum chamber between 200 mTorr and 2 Torr. The plasma test on four sample parts was in the presence of hydrogen-air mixture. The first sample had chamber pressures between 200 mTorr and 400 mTorr. The remaining three samples had chamber

  3. Idaho Waste Vitrification Facilities Project Vitrified Waste Interim Storage Facility

    Energy Technology Data Exchange (ETDEWEB)

    Bonnema, Bruce Edward

    2001-09-01

    This feasibility study report presents a draft design of the Vitrified Waste Interim Storage Facility (VWISF), which is one of three subprojects of the Idaho Waste Vitrification Facilities (IWVF) project. The primary goal of the IWVF project is to design and construct a treatment process system that will vitrify the sodium-bearing waste (SBW) to a final waste form. The project will consist of three subprojects that include the Waste Collection Tanks Facility, the Waste Vitrification Facility (WVF), and the VWISF. The Waste Collection Tanks Facility will provide for waste collection, feed mixing, and surge storage for SBW and newly generated liquid waste from ongoing operations at the Idaho Nuclear Technology and Engineering Center. The WVF will contain the vitrification process that will mix the waste with glass-forming chemicals or frit and turn the waste into glass. The VWISF will provide a shielded storage facility for the glass until the waste can be disposed at either the Waste Isolation Pilot Plant as mixed transuranic waste or at the future national geological repository as high-level waste glass, pending the outcome of a Waste Incidental to Reprocessing determination, which is currently in progress. A secondary goal is to provide a facility that can be easily modified later to accommodate storage of the vitrified high-level waste calcine. The objective of this study was to determine the feasibility of the VWISF, which would be constructed in compliance with applicable federal, state, and local laws. This project supports the Department of Energy’s Environmental Management missions of safely storing and treating radioactive wastes as well as meeting Federal Facility Compliance commitments made to the State of Idaho.

  4. Laser Initiation and Radiofrequency Sustainment of Seeded Air Plasmas

    Science.gov (United States)

    2006-04-01

    pressure plasma that projects well away from the antenna by this means that could not be obtained by RF alone. The initial plasma ionization also...a much lower RF power levels and with more enhanced axial projection away from the antenna with laser initiation than without. Power densities of 1...SCIENTECH ( Astral AD30). In order to account for the laser attenuation by the UV window, the UV window is placed in front of the energy meter. A laser

  5. The AMY experiment: Microwave emission from air shower plasmas

    Directory of Open Access Journals (Sweden)

    Alvarez-Muñiz J.

    2016-01-01

    Full Text Available You The Air Microwave Yield (AMY experiment investigate the molecular bremsstrahlung radiation emitted in the GHz frequency range from an electron beam induced air-shower. The measurements have been performed at the Beam Test Facility (BTF of Frascati INFN National Laboratories with a 510 MeV electron beam in a wide frequency range between 1 and 20 GHz. We present the apparatus and the results of the tests performed.

  6. Local geology controlled the feasibility of vitrifying Iron Age buildings.

    Science.gov (United States)

    Wadsworth, Fabian B; Heap, Michael J; Damby, David E; Hess, Kai-Uwe; Najorka, Jens; Vasseur, Jérémie; Fahrner, Dominik; Dingwell, Donald B

    2017-01-12

    During European prehistory, hilltop enclosures made from polydisperse particle-and-block stone walling were exposed to temperatures sufficient to partially melt the constituent stonework, leading to the preservation of glassy walls called 'vitrified forts'. During vitrification, the granular wall rocks partially melt, sinter viscously and densify, reducing inter-particle porosity. This process is strongly dependent on the solidus temperature, the particle sizes, the temperature-dependence of the viscosity of the evolving liquid phase, as well as the distribution and longevity of heat. Examination of the sintering behaviour of 45 European examples reveals that it is the raw building material that governs the vitrification efficiency. As Iron Age forts were commonly constructed from local stone, we conclude that local geology directly influenced the degree to which buildings were vitrified in the Iron Age. Additionally, we find that vitrification is accompanied by a bulk material strengthening of the aggregates of small sizes, and a partial weakening of larger blocks. We discuss these findings in the context of the debate surrounding the motive of the wall-builders. We conclude that if wall stability by bulk strengthening was the desired effect, then vitrification represents an Iron Age technology that failed to be effective in regions of refractory local geology.

  7. Local geology controlled the feasibility of vitrifying Iron Age buildings

    Science.gov (United States)

    Fabian B Wadsworth,; Michael J Heap,; Damby, David; Kai-Uwe Hess,; Jens Najorka,; Jérémie Vasseur,; Dominik Fahrner,; Donald B Dingwell,

    2017-01-01

    During European prehistory, hilltop enclosures made from polydisperse particle-and-block stone walling were exposed to temperatures sufficient to partially melt the constituent stonework, leading to the preservation of glassy walls called ‘vitrified forts’. During vitrification, the granular wall rocks partially melt, sinter viscously and densify, reducing inter-particle porosity. This process is strongly dependent on the solidus temperature, the particle sizes, the temperature-dependence of the viscosity of the evolving liquid phase, as well as the distribution and longevity of heat. Examination of the sintering behaviour of 45 European examples reveals that it is the raw building material that governs the vitrification efficiency. As Iron Age forts were commonly constructed from local stone, we conclude that local geology directly influenced the degree to which buildings were vitrified in the Iron Age. Additionally, we find that vitrification is accompanied by a bulk material strengthening of the aggregates of small sizes, and a partial weakening of larger blocks. We discuss these findings in the context of the debate surrounding the motive of the wall-builders. We conclude that if wall stability by bulk strengthening was the desired effect, then vitrification represents an Iron Age technology that failed to be effective in regions of refractory local geology.

  8. Investigation of sewage sludge treatment using air plasma assisted gasification.

    Science.gov (United States)

    Striūgas, Nerijus; Valinčius, Vitas; Pedišius, Nerijus; Poškas, Robertas; Zakarauskas, Kęstutis

    2017-06-01

    This study presents an experimental investigation of downdraft gasification process coupled with a secondary thermal plasma reactor in order to perform experimental investigations of sewage sludge gasification, and compare process parameters running the system with and without the secondary thermal plasma reactor. The experimental investigation were performed with non-pelletized mixture of dried sewage sludge and wood pellets. To estimate the process performance, the composition of the producer gas, tars, particle matter, producer gas and char yield were measured at the exit of the gasification and plasma reactor. The research revealed the distribution of selected metals and chlorine in the process products and examined a possible formation of hexachlorobenzene. It determined that the plasma assisted processing of gaseous products changes the composition of the tars and the producer gas, mostly by destruction of hydrocarbon species, such as methane, acetylene, ethane or propane. Plasma processing of the producer gas reduces their calorific value but increases the gas yield and the total produced energy amount. The presented technology demonstrated capability both for applying to reduce the accumulation of the sewage sludge and production of substitute gas for drying of sewage sludge and electrical power. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Investigation on Plasma Jet Flow Phenomena During DC Air Arc Motion in Bridge-Type Contacts

    Science.gov (United States)

    Zhai, Guofu; Bo, Kai; Chen, Mo; Zhou, Xue; Qiao, Xinlei

    2016-05-01

    Arc plasma jet flow in the air was investigated under a bridge-type contacts in a DC 270 V resistive circuit. We characterized the arc plasma jet flow appearance at different currents by using high-speed photography, and two polished contacts were used to search for the relationship between roughness and plasma jet flow. Then, to make the nature of arc plasma jet flow phenomena clear, a simplified model based on magnetohydrodynamic (MHD) theory was established and calculated. The simulated DC arc plasma was presented with the temperature distribution and the current density distribution. Furthermore, the calculated arc flow velocity field showed that the circular vortex was an embodiment of the arc plasma jet flow progress. The combined action of volume force and contact surface was the main reason of the arc jet flow. supported by National Natural Science Foundation of China (Nos. 51307030, 51277038)

  10. Investigation on Plasma Jet Flow Phenomena During DC Air Arc Motion in Bridge-Type Contacts

    Institute of Scientific and Technical Information of China (English)

    ZHAI Guofu; BO Kai; CHEN Mo; ZHOU Xue; QIAO Xinlei

    2016-01-01

    Arc plasma jet flow in the air was investigated under a bridge-type contacts in a DC 270 V resistive circuit.We characterized the arc plasma jet flow appearance at different currents by using high-speed photography,and two polished contacts were used to search for the relationship between roughness and plasma jet flow.Then,to make the nature of arc plasma jet flow phenomena clear,a simplified model based on magnetohydrodynamic (MHD) theory was established and calculated.The simulated DC arc plasma was presented with the temperature distribution and the current density distribution.Furthermore,the calculated arc flow vclocity field showed that the circular vortex was an embodiment of the arc plasma jet flow progress.The combined action of volume force and contact surface was the main reason of the arc jet flow.

  11. Surface adhesive properties of continuous PBO fiber after air-plasma-grafting-epoxy treatment

    Institute of Scientific and Technical Information of China (English)

    贾彩霞; 王乾; 陈平; 蒲永伟

    2016-01-01

    It was found that air dielectric barrier discharge (DBD) plasma contributed to the grafting of epoxy resin onto continuous PBO fiber surface. This air-plasma-grafting-epoxy method yielded a noticeable enhancement in the interfacial adhesion between PBO fiber and thermoplastic matrix resin, with the interlaminar shear strength of the resulting composites increased by 66.7%. DSC and FTIR analyses were then used to study the curing behavior of epoxy coating on PBO fiber surface, deduce the possible grafting reactions and investigate the grafting mechanism. More importantly, TGA measurement showed that the grafting of epoxy onto PBO fiber had almost no effect on the composite heat resistance, and there was more thermoplastic matrix resin adhering to the fiber surface; the latter could also be clearly found in the SEM photos. Thereby, the air-plasma-grafting-epoxy treatment was proved to be an effective method for the improvement of continuous PBO fiber surface adhesive properties.

  12. Calculation of transport coefficients of air-water vapor mixtures thermal plasmas used in circuit breakers

    Directory of Open Access Journals (Sweden)

    KOHIO Niéssan

    2014-12-01

    Full Text Available In this paper we calculate the transport coefficients of plasmas formed by air and water vapor mixtures. The calculation, which assume local thermodynamic equilibrium (LTE are performed in the temperature range from 500 to 12000 K. We use the Gibbs free energy minimization method to determine the equilibrium composition of the plasmas, which is necessary to calculate the transport coefficients. We use the Chapman-Enskog method to calculate the transport coefficients. The results are presented and discussed according to the rate of water vapor. The results of the total thermal conductivity and electrical conductivity show in particular that the increasing of the rate of water vapor in air can be interesting for power cut. This could be improve the performance of plasma during current breaking in air contaminate by the water vapor.

  13. 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.

  14. Optimization of atmospheric air plasma for degradation of organic dyes in wastewater.

    Science.gov (United States)

    Sarangapani, Chaitanya; Dixit, Y; Milosavljevic, Vladimir; Bourke, Paula; Sullivan, Carl; Cullen, P J

    2017-01-01

    This study optimises the degradation of a cocktail of the dyes methyl orange and bromothymol blue by atmospheric air plasma. Response surface methodology (RSM) was employed to investigate the efficacy of the plasma process parameters on degradation efficiency. A Box-Behnken design (BBD) was employed to optimise the degradation of dyes by air plasma discharge. A second order polynomial equation was proposed to predict process efficiency. It was observed that the predicted values are significant (p degradation, pH value and ozone concentration, respectively. The analysis of variance results showed that the coefficients of the polynomials for the percentage degradation and ozone concentration responses indicated positive linear effects (p degradation efficiencies are achieved with an increase in treatment duration. This study showed that a BBD model and RSM could be employed to optimize the colour degradation parameters of non-thermal plasma treated model dyes while minimising the number of experiments required.

  15. Plasma channel formed by ultraviolet laser pulses at 193 nm in air

    Institute of Scientific and Technical Information of China (English)

    Yuanyuan Ma; Xin Lu; Tingting Xi; Qihuang Gong; Jie Zhang

    2009-01-01

    The propagation of picosecond deep ultraviolet laser pulse at wavelength of 193 nm in air is numerically investigated.Long plasma channel can be formed due to the competition between Kerr self-focusing and ionization induced defocusing.The plasma channel with electron density of above 1013/cma can be formed over 70 m by 50-ps,20-mJ laser pulses.The fluctuation of laser intensity and electron density inside ultraviolet(UV)plasma channel is significantly lower than that of infrared pulse.The linear absorption of UV laser by air is considered in the simulation and it is shown that the linear absorption is important for the limit of the length of plasma channel.

  16. Simulation of cold atmospheric plasma component composition and particle densities in air

    Science.gov (United States)

    Kirsanov, Gennady; Chirtsov, Alexander; Kudryavtsev, Anatoliy

    2015-11-01

    Recently discharges in air at atmospheric pressure were the subject of numerous studies. Of particular interest are the cold streams of air plasma, which contains large amounts of chemically active species. It is their action can be decisive in the interaction with living tissues. Therefore, in addition to its physical properties, it is important to know the component composition and particle densities. The goal was to develop a numerical model of atmospheric pressure glow microdischarge in air with the definition of the component composition of plasma. To achieve this goal the task was divided into two sub-tasks, in the first simulated microdischarge atmospheric pressure in air using a simplified set of plasma chemical reactions in order to obtain the basic characteristics of the discharge, which are the initial approximations in the problem of the calculation of the densities with detailed plasma chemistry, including 53 spices and over 600 chemical reactions. As a result of the model was created, which can be adapted for calculating the component composition of plasma of various sources. Calculate the density of particles in the glow microdischarges and dynamics of their change in time.

  17. Influence of air pressure on mechanical effect of laser plasma shock wave

    Institute of Scientific and Technical Information of China (English)

    Zhang Yu-Zhu; Wang Guang-An; Zhu Jin-Rong; Shen Zhong-Hua; Ni Xiao-Wu; Lu Jian

    2007-01-01

    The influence of air pressure on mechanical effect of laser plasma shock wave in a vacuum chamber produced by a Nd:YAG laser has been studied. The laser pulses with pulse width of 10ns and pulse energy of about 320mJ at 1.06μm wavelength is focused on the aluminium target mounted on a ballistic pendulum, and the air pressure in the chamber changes from 2.8 × 103 to 1.01×105pa. The experimental results show that the impulse coupling coefficient changes as the air pressure and the distance of the target from focus change. The mechanical effects of the plasma shock wave on the target are analysed at different distances from focus and the air pressure.

  18. Influence of air pressure on mechanical effect of laser plasma shock wave

    Science.gov (United States)

    Zhang, Yu-Zhu; Wang, Guang-An; Zhu, Jin-Rong; Shen, Zhong-Hua; Ni, Xiao-Wu; Lu, Jian

    2007-09-01

    The influence of air pressure on mechanical effect of laser plasma shock wave in a vacuum chamber produced by a Nd:YAG laser has been studied. The laser pulses with pulse width of 10ns and pulse energy of about 320mJ at 1.06μm wavelength is focused on the aluminium target mounted on a ballistic pendulum, and the air pressure in the chamber changes from 2.8 × 103 to 1.01 × 105Pa. The experimental results show that the impulse coupling coefficient changes as the air pressure and the distance of the target from focus change. The mechanical effects of the plasma shock wave on the target are analysed at different distances from focus and the air pressure.

  19. Resonant- and avalanche-ionization amplification of laser-induced plasma in air

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Yue; Zhang, Zhili, E-mail: zzhang24@utk.edu [Department of Mechanical, Aerospace and Biomedical Engineering, University of Tennessee, Knoxville, Tennessee 37996 (United States); Jiang, Naibo; Roy, Sukesh [Spectral Energies, LLC, 5100 Springfield St., Suite 301, Dayton, Ohio 45431 (United States); Gord, James R. [Air Force Research Laboratory, Aerospace Systems Directorate, Wright-Patterson Air Force Base, Ohio 45433 (United States)

    2014-10-14

    Amplification of laser-induced plasma in air is demonstrated utilizing resonant laser ionization and avalanche ionization. Molecular oxygen in air is ionized by a low-energy laser pulse employing (2 + 1) resonance-enhanced multi-photon ionization (REMPI) to generate seed electrons. Subsequent avalanche ionization of molecular oxygen and nitrogen significantly amplifies the laser-induced plasma. In this plasma-amplification effect, three-body attachments to molecular oxygen dominate the electron-generation and -loss processes, while either nitrogen or argon acts as the third body with low electron affinity. Contour maps of the electron density within the plasma obtained in O₂/N₂ and O₂/Ar gas mixtures are provided to show relative degrees of plasma amplification with respect to gas pressure and to verify that the seed electrons generated by O₂ 2 + 1 REMPI are selectively amplified by avalanche ionization of molecular nitrogen in a relatively low-pressure condition (≤100 Torr). Such plasma amplification occurring in air could be useful in aerospace applications at high altitude.

  20. Surface-dependent inactivation of model microorganisms with shielded sliding plasma discharges and applied air flow.

    Science.gov (United States)

    Edelblute, Chelsea M; Malik, Muhammad A; Heller, Loree C

    2015-06-01

    Cold atmospheric plasma inactivates bacteria through reactive species produced from the applied gas. The use of cold plasma clinically has gained recent interest, as the need for alternative or supplementary strategies are necessary for preventing multi-drug resistant infections. The purpose of this study was to evaluate the antibacterial efficacy of a novel shielded sliding discharge based cold plasma reactor operated by nanosecond voltage pulses in atmospheric air on both biotic and inanimate surfaces. Bacterial inactivation was determined by direct quantification of colony forming units. The plasma activated air (afterglow) was bactericidal against Escherichia coli and Staphylococcus epidermidis seeded on culture media, laminate, and linoleum vinyl. In general, E. coli was more susceptible to plasma exposure. A bacterial reduction was observed with the application of air alone on a laminate surface. Whole-cell real-time PCR revealed a decrease in the presence of E. coli genomic DNA on exposed samples. These findings suggest that plasma-induced bacterial inactivation is surface-dependent.

  1. Atmospheric air-plasma treatment of polyester fiber to improve the performance of nanoemulsion silicone

    Energy Technology Data Exchange (ETDEWEB)

    Parvinzadeh, Mazeyar, E-mail: mparvinzadeh@gmail.com [Department of Textile, Islamic Azad University, Shahre Rey Branch, Tehran (Iran, Islamic Republic of); Ebrahimi, Izadyar [Young Researchers Club, Islamic Azad University, Shahre Rey Branch, Tehran (Iran, Islamic Republic of)

    2011-02-15

    Influence of atmospheric air plasma treatment on performance of nanoemulsion silicone softener on polyethylene terephthalate fibers was investigated by the use of fourier transform infrared spectroscopy (FTIR), bending lengths (BL), wrinkle recovery angles (WRA), fiber friction coefficient analysis (FFCA), moisture absorbency (MA), scanning electron microscopy (SEM) and reflectance spectroscopy (RS). Results indicated that the plasma pretreatment modifies the surface of fibers and increases the reactivity of substrate toward nanoemulsion silicone. Moisture regain and microscopic tests showed that the combination of plasma and silicone treatments on polyethylene terephthalate can decrease moisture absorption due to uniform coating of silicone emulsion on surface of fibers.

  2. Optimally enhanced optical emission in laser-induced air plasma by femtosecond double-pulse

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Anmin [Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012 (China); Institute of Theoretical Chemistry, State Key Laboratory of Theoretical and Computational Chemistry, Jilin University, Changchun 130012 (China); Li, Suyu; Li, Shuchang; Jiang, Yuanfei; Ding, Dajun [Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012 (China); Shao, Junfeng; Wang, Tingfeng [State Key Laboratory of Laser Interaction with Matter, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033 (China); Huang, Xuri [Institute of Theoretical Chemistry, State Key Laboratory of Theoretical and Computational Chemistry, Jilin University, Changchun 130012 (China); Jin, Mingxing [Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012 (China); State Key Laboratory of Laser Interaction with Matter, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033 (China)

    2013-10-15

    In laser-induced breakdown spectroscopy, a femtosecond double-pulse laser was used to induce air plasma. The plasma spectroscopy was observed to lead to significant increase of the intensity and reproducibility of the optical emission signal compared to femtosecond single-pulse laser. In particular, the optical emission intensity can be optimized by adjusting the delay time of femtosecond double-pulse. An appropriate pulse-to-pulse delay was selected, that was typically about 50 ps. This effect can be especially advantageous in the context of femtosecond laser-induced breakdown spectroscopy, plasma channel, and so on.

  3. Genetic effects of an air discharge plasma on Staphylococcus aureus at the gene transcription level

    Science.gov (United States)

    Xu, Zimu; Wei, Jun; Shen, Jie; Liu, Yuan; Ma, Ronghua; Zhang, Zelong; Qian, Shulou; Ma, Jie; Lan, Yan; Zhang, Hao; Zhao, Ying; Xia, Weidong; Sun, Qiang; Cheng, Cheng; Chu, Paul K.

    2015-05-01

    The dynamics of gene expression regulation (at transcription level) in Staphylococcus aureus after different doses of atmospheric-pressure room-temperature air plasma treatments are investigated by monitoring the quantitative real-time polymerase chain reaction. The plasma treatment influences the transcription of genes which are associated with several important bio-molecular processes related to the environmental stress resistance of the bacteria, including oxidative stress response, biofilm formation, antibiotics resistance, and DNA damage protection/repair. The reactive species generated by the plasma discharge in the gas phase and/or induced in the liquid phase may account for these gene expression changes.

  4. Air plasma kinetics under the influence of sprites

    OpenAIRE

    Gordillo Vázquez, Francisco J.

    2008-01-01

    A full time-dependent kinetic study is presented for the main microscopic collisional and radiative processes underlying the optical flashes associated with an impulsive (τ = 5 μs) discharge in the form of a single sprite streamer passing through an air region of the mesosphere at three different altitudes (63, 68 and 78 km). The kinetic formalism developed includes the coupling of the rate equations of each of the different species considered (electrons, ions, atoms and molecules) with the B...

  5. Interaction of high-power microwave with air breakdown plasma at low pressure

    Science.gov (United States)

    Zhao, Pengcheng; Guo, Lixin; Shu, Panpan

    2016-09-01

    The high-power microwave breakdown at the low air pressure (about 0.01 atm) is simulated numerically using the one-dimensional model coupling Maxwell's equations with plasma fluid equations. The accuracy of the model is validated by comparing the breakdown prediction with the experimental data. We find that a diffuse plasma with a stationary front profile forms due to the large electron diffusion. Most of the incident wave energy is absorbed and reflected by the plasma when the plasma front achieves a stationary profile. The front propagation velocity remains almost unchanged with time and increases when the incident wave amplitude increases or the incident wave frequency decreases. With the incident wave frequency increasing, the maximum density of the stationary plasma front increases, while the ratio of the reflected wave power to the incident wave power remains almost unchanged. At a higher incident wave amplitude, the maximum density and reflectance become large.

  6. Mechanism of laser-induced plasma shock wave evolution in air

    Institute of Scientific and Technical Information of China (English)

    Zhao Rui; Liang Zhong-Cheng; Han Bing; Zhang Hong-Chao; Xu Rong-Qing; Lu Jian; Ni Xiao-Wu

    2009-01-01

    A theoretical model is proposed to describe the mechanism of laser-induced plasma shock wave evolution in air. To verify the validity of the theoretical model, an optical beam deflection technique is employed to track the plasma shock wave evolution process. The theoretical model and the experimental signals are found to be in good agreement with each other. It is shown that the laser-induced plasma shock wave undergoes formation, increase and decay processes; the increase and the decay processes of the laser-induced plasma shock wave result from the overlapping of the compression wave and the rarefaction wave, respectively. In addition, the laser-induced plasma shock wave speed and pressure distributions, both a function of distance, are presented.

  7. Surface functionalization of macroporous polymeric materials by treatment with air low temperature plasma.

    Science.gov (United States)

    Molina, R; Sole, I; Vílchez, A; Bertran, E; Solans, C; Esquena, J

    2013-04-01

    Polystyrene/divinylbenzene (PS-DVB) macroporous monoliths obtained using highly concentrated emulsions as templates show a superhydrophobic behaviour, restricting their potential technological applications, especially those related to adhesion and wetting. Air plasma treatments were carried out in order to modulate wetting properties, modifying the surface chemical composition of macroporous polystyrene/divinylbenzene materials. The superhydrophobic behaviour was rapidly suppressed by air plasma treatment, greatly reducing the water contact angle, from approximately 150 degrees to approximately 90 degrees, in only 10 seconds of treatment. The new surface chemical groups, promoted by plasma active species, were characterized by surface analysis techniques with different depth penetration specificity (contact angle, XPS, FTIR and SEM). Results demonstrated that very short treatment times produced different chemical functionalities, mainly C-O, C=O, O-C=O and C-N, which provide the materials with predominantly acidic surface properties. However, plasma active species did not penetrate deeply through the interconnected pores of the material. FTIR analysis evidenced that the new hydrophilic surface groups promoted by plasma active species are in a negligibly concentration compared to bulk chemical groups, and are located in a very thin surface region on the PS-DVB monolith surface (significantly below 2 microm). XPS analysis of treated monoliths revealed a progressive increase of oxygen and nitrogen content as a function of plasma treatment time. However, oxidation of the PS-DVB monoliths surface prevails over the incorporation of nitrogen atoms. Finally, SEM studies indicated that the morphology of the plasma treated PS-DVB does not significantly change even for the longest air plasma treatment time studied (120 s).

  8. The radiation characteristics of the transport packages with vitrified high-level waste

    Science.gov (United States)

    Bogatov, S. A.; Mitenkova, E. F.; Novikov, N. V.

    2015-12-01

    The calculation method of neutron yield in the (α, n) reaction for a homogeneous material of arbitrary composition is represented. It is shown that the use of the ORIGEN 2 code excluding the real elemental composition of vitrified high-level waste leads to significant underestimation of the neutron yield in the (α, n) reaction. For vitrified high-level waste and spent nuclear fuel from VVER, the neutron fluxes are analyzed. The thickness of the protective materials for a transfer cask and a shipping cask with vitrified highlevel waste are estimated.

  9. The radiation characteristics of the transport packages with vitrified high-level waste

    Energy Technology Data Exchange (ETDEWEB)

    Bogatov, S. A. [JSC VNIPIpromtechnologii (Russian Federation); Mitenkova, E. F., E-mail: mit@ibrae.ac.ru; Novikov, N. V. [Russian Academy of Sciences, Nuclear Safety Institute (Russian Federation)

    2015-12-15

    The calculation method of neutron yield in the (α, n) reaction for a homogeneous material of arbitrary composition is represented. It is shown that the use of the ORIGEN 2 code excluding the real elemental composition of vitrified high-level waste leads to significant underestimation of the neutron yield in the (α, n) reaction. For vitrified high-level waste and spent nuclear fuel from VVER, the neutron fluxes are analyzed. The thickness of the protective materials for a transfer cask and a shipping cask with vitrified highlevel waste are estimated.

  10. Recovering vitrified carnation (Dianthus caryophyllus L.) shoots using Bacto-Peptone and its subfractions.

    Science.gov (United States)

    Sato, S; Hagimori, M; Iwai, S

    1993-05-01

    Vitrified shoots regenerated from carnation petals (Dianthus caryophyllus L. cv. Scania) were recovered by culturing them in a medium containing 3.0 g/l Bacto-Peptone. Wax structures not found on vitrified shoots developed on the abaxial surface of leaves of recovered shoots and on those of normal leaves. Recovered shoots were rooted and successfully acclimatized while vitrified shoots could not survive the acclimatization process. The Bacto-Peptone solution was fractionated and the efficiency of each fraction for the recovery of vitrification was examined. Only basic, non high molecular fractions whose molecular weight was less than 10,000 were effective.

  11. Neutral oxygen atom density in the MESOX air plasma solar furnace facility

    Science.gov (United States)

    Balat-Pichelin, Marianne; Vesel, Alenka

    2006-08-01

    The density of neutral oxygen atoms in the MESOX set-up, one device of the PROMES-CNRS solar facilities, was determined by a fiber-optics catalytic probe (FOCP). Plasma was created in a flowing air within a quartz tube with the outer diameter of 5 cm by a 2.45 GHz microwave generator with the output power up to 1000 W. The flow of air was varied between 4 and 20 l/h. The O-atom density was found to increase monotonously with the increasing discharge power, and it decreased with the increasing flow rate. The degree of dissociation of oxygen molecules in the plasma column depended largely on the flow rate. At the air flow of 4 l/h it was about 80% but it decreased to about 20% at the flow of 20 l/h.

  12. Neutral oxygen atom density in the MESOX air plasma solar furnace facility

    Energy Technology Data Exchange (ETDEWEB)

    Balat-Pichelin, Marianne [CNRS-PROMES, Laboratoire Procedes, Materiaux et Energie Solaire, UPR 8521, 7 rue du four solaire, F-66120 Font Romeu, Odeillo (France)], E-mail: balat@promes.cnrs.fr; Vesel, Alenka [Jozef Stefan Institute, Jamova 39, 1000 Ljubljana (Slovenia)

    2006-08-21

    The density of neutral oxygen atoms in the MESOX set-up, one device of the PROMES-CNRS solar facilities, was determined by a fiber-optics catalytic probe (FOCP). Plasma was created in a flowing air within a quartz tube with the outer diameter of 5 cm by a 2.45 GHz microwave generator with the output power up to 1000 W. The flow of air was varied between 4 and 20 l/h. The O-atom density was found to increase monotonously with the increasing discharge power, and it decreased with the increasing flow rate. The degree of dissociation of oxygen molecules in the plasma column depended largely on the flow rate. At the air flow of 4 l/h it was about 80% but it decreased to about 20% at the flow of 20 l/h.

  13. Emission characteristics of kerosene-air spray combustion with plasma assistance

    Directory of Open Access Journals (Sweden)

    Xingjian Liu

    2015-09-01

    Full Text Available A plasma assisted combustion system for combustion of kerosene-air mixtures was developed to study emission levels of O2, CO2, CO, and NOx. The emission measurement was conducted by Testo 350-Pro Flue Gas Analyzer. The effect of duty ratio, feedstock gas flow rate and applied voltage on emission performance has been analyzed. The results show that O2 and CO emissions reduce with an increase of applied voltage, while CO2 and NOx emissions increase. Besides, when duty ratio or feedstock gas flow rate decreases, the same emission results would appear. The emission spectrum of the air plasma of plasma assisted combustion actuator was also registered to analyze the kinetic enhancement effect of plasma, and the generation of ozone was believed to be the main factor that plasma makes a difference in our experiment. These results are valuable for the future optimization of kerosene-fueled aircraft engine when using plasma assisted combustion devices to exert emission control.

  14. Analytic Hierarchy and Economic Analysis of a Plasma Gasification System for Naval Air Station Oceana-Dam Neck

    Science.gov (United States)

    2014-08-30

    Hierarchy and Economic Analysis of a Plasma Gasification System for Naval Air Station Oceana-Dam Neck Matthew R. Yost Report...REPORT TYPE 3. DATES COVERED 4. TITLE AND SUBTITLE Analytic Hierarchy and Economic Analysis of a Plasma Gasification System for Naval Air...ABSTRACT The overall objective of this project was to determine if a plasma gasification system is a possible alternative to the current system of MSW

  15. The roles of various plasma species in the plasma and plasma-catalytic removal of low-concentration formaldehyde in air.

    Science.gov (United States)

    Fan, Xing; Zhu, Tianle; Sun, Yifei; Yan, Xiao

    2011-11-30

    The contributions of various plasma species to the removal of low-concentration formaldehyde (HCHO) in air by DC corona discharge plasma in the presence and absence of downstream MnO(x)/Al(2)O(3) catalyst were systematically investigated in this study. Experimental results show that HCHO can be removed not only by short-living active species in the discharge zone, but also by long-living species except O(3) downstream the plasma reactor. O(3) on its own is incapable of removing HCHO in the gas phase but when combined with the MnO(x)/Al(2)O(3) catalyst, considerable HCHO conversion is seen, well explaining the greatly enhanced HCHO removal by combining plasma with catalysis. The plasma-catalysis hybrid process where HCHO is introduced through the discharge zone and then the catalyst bed exhibits the highest energy efficiency concerning HCHO conversion, due to the best use of plasma-generated active species in a two-stage HCHO destruction process. Moreover, the presence of downstream MnO(x)/Al(2)O(3) catalyst significantly reduced the emission of discharge byproducts (O(3)) and organic intermediates (HCOOH).

  16. Influence of metallic vapours on thermodynamic and transport properties of two-temperature air plasma

    Science.gov (United States)

    Zhong, Linlin; Wang, Xiaohua; Cressault, Yann; Teulet, Philippe; Rong, Mingzhe

    2016-09-01

    The metallic vapours (i.e., copper, iron, and silver in this paper) resulting from walls and/or electrode surfaces can significantly affect the characteristics of air plasma. Different from the previous works assuming local thermodynamic equilibrium, this paper investigates the influence of metallic vapours on two-temperature (2 T) air plasma. The 2 T compositions of air contaminated by Cu, Fe, and Ag are first determined based on Saha's and Guldberg-Waage's laws. The thermodynamic properties (including mass density, specific enthalpy, and specific heat) are then calculated according to their definitions. After determining the collision integrals for each pair of species in air-metal mixtures using the newly published methods and source data, the transport coefficients (including electrical conductivity, viscosity, and thermal conductivity) are calculated for air-Cu, air-Fe, and air-Ag plasmas with different non-equilibrium degree θ (Te/Th). The influences of metallic contamination as well as non-equilibrium degree are discussed. It is found that copper, iron, and silver exist mainly in the form of Cu2, FeO, and AgO at low temperatures. Generally, the metallic vapours increase mass density at most temperatures, reduce the specific enthalpy and specific heat in the whole temperature range, and affect the transport properties remarkably from 5000 K to 20 000 K. The effect arising from the type of metals is little except for silver at certain temperatures. Besides, the departure from thermal equilibrium results in the delay of dissociation and ionization reactions, leading to the shift of thermodynamic and transport properties towards a higher temperature.

  17. Streptococci biofilm decontamination on teeth by low-temperature air plasma of dc corona discharges

    Science.gov (United States)

    Kovalóvá, Z.; Zahoran, M.; Zahoranová, A.; Machala, Z.

    2014-06-01

    Non-thermal plasmas of atmospheric pressure air direct current corona discharges were investigated for potential applications in dental medicine. The objective of this ex vivo study was to apply cold plasmas for the decontamination of Streptococci biofilm grown on extracted human teeth, and to estimate their antimicrobial efficiency and the plasma's impact on the enamel and dentine of the treated tooth surfaces. The results show that both positive streamer and negative Trichel pulse coronas can reduce bacterial population in the biofilm by up to 3 logs in a 10 min exposure time. This bactericidal effect can be reached faster (within 5 min) by electrostatic spraying of water through the discharge onto the treated tooth surface. Examination of the tooth surface after plasma exposure by infrared spectroscopy and scanning electron microscopy did not show any significant alteration in the tooth material composition or the tooth surface structures.

  18. Microstructure of Suspension Plasma Spray and Air Plasma Spray Al2O3-ZrO2 Composite Coatings

    Science.gov (United States)

    Chen, Dianying; Jordan, Eric H.; Gell, Maurice

    2009-09-01

    Al2O3-ZrO2 coatings were deposited by the suspension plasma spray (SPS) molecularly mixed amorphous powder and the conventional air plasma spray (APS) Al2O3-ZrO2 crystalline powder. The amorphous powder was produced by heat treatment of molecularly mixed chemical solution precursors below their crystallization temperatures. Phase composition and microstructure of the as-synthesized and heat-treated SPS and APS coatings were characterized by XRD and SEM. XRD analysis shows that the as-sprayed SPS coating is composed of α-Al2O3 and tetragonal ZrO2 phases, while the as-sprayed APS coating consists of tetragonal ZrO2, α-Al2O3, and γ-Al2O3 phases. Microstructure characterization revealed that the Al2O3 and ZrO2 phase distribution in SPS coatings is much more homogeneous than that of APS coatings.

  19. Laser-guided energetic discharges over large air gaps by electric-field enhanced plasma filaments

    Science.gov (United States)

    Théberge, Francis; Daigle, Jean-François; Kieffer, Jean-Claude; Vidal, François; Châteauneuf , Marc

    2017-01-01

    Recent works on plasma channels produced during the propagation of ultrashort and intense laser pulses in air demonstrated the guiding of electric discharges along the laser path. However, the short plasma lifetime limits the length of the laser-guided discharge. In this paper, the conductivity and lifetime of long plasma channels produced by ultrashort laser pulses is enhanced efficiently over many orders of magnitude by the electric field of a hybrid AC-DC high-voltage source. The AC electric pulse from a Tesla coil allowed to stimulate and maintain the highly conductive channel during few milliseconds in order to guide a subsequent 500 times more energetic discharge from a 30-kV DC source. This DC discharge was laser-guided over an air gap length of two metres, which is more than two orders of magnitude longer than the expected natural discharge length. Long plasma channel induced by laser pulses and stimulated by an external high-voltage source opens the way for wireless and efficient transportation of energetic current pulses over long air gaps and potentially for guiding lightning. PMID:28053312

  20. Laser-guided energetic discharges over large air gaps by electric-field enhanced plasma filaments

    Science.gov (United States)

    Théberge, Francis; Daigle, Jean-François; Kieffer, Jean-Claude; Vidal, François; Châteauneuf, Marc

    2017-01-01

    Recent works on plasma channels produced during the propagation of ultrashort and intense laser pulses in air demonstrated the guiding of electric discharges along the laser path. However, the short plasma lifetime limits the length of the laser-guided discharge. In this paper, the conductivity and lifetime of long plasma channels produced by ultrashort laser pulses is enhanced efficiently over many orders of magnitude by the electric field of a hybrid AC-DC high-voltage source. The AC electric pulse from a Tesla coil allowed to stimulate and maintain the highly conductive channel during few milliseconds in order to guide a subsequent 500 times more energetic discharge from a 30-kV DC source. This DC discharge was laser-guided over an air gap length of two metres, which is more than two orders of magnitude longer than the expected natural discharge length. Long plasma channel induced by laser pulses and stimulated by an external high-voltage source opens the way for wireless and efficient transportation of energetic current pulses over long air gaps and potentially for guiding lightning.

  1. Cold air plasma to decontaminate inanimate surfaces of the hospital environment.

    Science.gov (United States)

    Cahill, Orla J; Claro, Tânia; O'Connor, Niall; Cafolla, Anthony A; Stevens, Niall T; Daniels, Stephen; Humphreys, Hilary

    2014-03-01

    The hospital environment harbors bacteria that may cause health care-associated infections. Microorganisms, such as multiresistant bacteria, can spread around the patient's inanimate environment. Some recently introduced biodecontamination approaches in hospitals have significant limitations due to the toxic nature of the gases and the length of time required for aeration. This study evaluated the in vitro use of cold air plasma as an efficient alternative to traditional methods of biodecontamination of hospital surfaces. Cultures of methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE), extended-spectrum-β-lactamase (ESBL)-producing Escherichia coli, and Acinetobacter baumannii were applied to different materials similar to those found in the hospital environment. Artificially contaminated sections of marmoleum, mattress, polypropylene, powder-coated mild steel, and stainless steel were then exposed to a cold air pressure plasma single jet for 30 s, 60 s, and 90 s, operating at approximately 25 W and 12 liters/min flow rate. Direct plasma exposure successfully reduced the bacterial load by log 3 for MRSA, log 2.7 for VRE, log 2 for ESBL-producing E. coli, and log 1.7 for A. baumannii. The present report confirms the efficient antibacterial activity of a cold air plasma single-jet plume on nosocomial bacterially contaminated surfaces over a short period of time and highlights its potential for routine biodecontamination in the clinical environment.

  2. Early-stage plasma dynamics with air ionization during ultrashort laser ablation of metal

    Energy Technology Data Exchange (ETDEWEB)

    Hu Wenqian; Shin, Yung C.; King, Galen [School of Mechanical Engineering, Purdue University, West Lafayette, Indiana 47907 (United States)

    2011-09-15

    In this study, the early-stage plasma evolution generated by an ultrashort laser pulse is investigated through pump-probe shadowgraph measurements and simulations. The measurements are performed to show the evolution of the plasma front, while the simulation model is used to further investigate the evolution process and mechanism. Specifically, the laser pulse propagation in air is simulated using the beam propagation method with the slowly varying envelope approximation. The lattice dynamics, the electron dynamics and the multi-scattering event, and the evolution of charged particles (free electrons and ions), are simulated using a molecular dynamics method, a Monte Carlo method, and a particle-in-cell method, respectively. With this simulation model, the refractive index and plasma evolutions are calculated and compared with measured results to validate the simulation model. Different plasma expansion processes, caused by the air ionization, are found with the focal point slightly above and below the target. Air ionization occurs in both cases, but their primary mechanisms are shown to be different.

  3. Physicochemical processes in the indirect interaction between surface air plasma and deionized water

    Science.gov (United States)

    Liu, Z. C.; Liu, D. X.; Chen, C.; Li, D.; Yang, A. J.; Rong, M. Z.; Chen, H. L.; Kong, M. G.

    2015-12-01

    One of the most central scientific questions for plasma applications in healthcare and environmental remediation is the chemical identity and the dose profile of plasma-induced reactive oxygen and nitrogen species (ROS/RNS) that can act on an object inside a liquid. A logical focus is on aqueous physicochemical processes near a sample with a direct link to their upstream gaseous processes in the plasma region and a separation gap from the liquid bulk. Here, a system-level modeling framework is developed for indirect interactions of surface air plasma and a deionized water bulk and its predictions are found to be in good agreement with the measurement of gas-phase ozone and aqueous long-living ROS/RNS concentrations. The plasma region is described with a global model, whereas the air gap and the liquid region are simulated with a 1D fluid model. All three regions are treated as one integrated entity and computed simultaneously. With experimental validation, the system-level modeling shows that the dominant aqueous ROS/RNS are long-living species (e.g. H2O2 aq, O3 aq, nitrite/nitrate, H+ aq). While most short-living gaseous species could hardly survive their passage to the liquid, aqueous short-living ROS/RNS are generated in situ through reactions among long-living plasma species and with water molecules. This plasma-mediated remote production of aqueous ROS/RNS is important for the abundance of aqueous HO2 aq, HO3 aq, OHaq and \\text{O}2- aq as well as NO2 aq and NO3 aq. Aqueous plasma chemistry offers a novel and significant pathway to activate a given biological outcome, as exemplified here for bacterial deactivation in plasma-activated water. Additional factors that may synergistically broaden the usefulness of aqueous plasma chemistry include an electric field by aqueous ions and liquid acidification. The system-modeling framework will be useful in assisting designs and analyses of future investigations of plasma-liquid and plasma-cell interactions.

  4. The generation of live offspring from vitrified oocytes.

    Directory of Open Access Journals (Sweden)

    L Gabriel Sanchez-Partida

    Full Text Available Oocyte cryopreservation is extremely beneficial for assisted reproductive technologies, the treatment of infertility and biotechnology and offers a viable alternative to embryo freezing and ovarian grafting approaches for the generation of embryonic stem cells and live offspring. It also offers the potential to store oocytes to rescue endangered species by somatic cell nuclear transfer and for the generation of embryonic stem cells to study development in these species. We vitrified mouse oocytes using a range of concentrations of trehalose (0 to 0.3 M and demonstrated that 0.1 and 0.3 M trehalose had similar developmental rates, which were significantly different to the 0.2 M cohort (P<0.05. As mitochondria are important for fertilisation outcome, we observed that the clustering and distribution of mitochondria of the 0.2 M cohort were more affected by vitifrication than the other groups. Nevertheless, all 3 cohorts were able to develop to blastocyst, following in vitro fertilisation, although developmental rates were better for the 0.1 and 0.3 M cohorts than the 0.2 M cohort (P<0.05. Whilst blastocysts gave rise to embryonic stem-like cells, it was apparent from immunocytochemistry and RT-PCR that these cells did not demonstrate true pluripotency and exhibited abnormal karyotypes. However, they gave rise to teratomas following injection into SCID mice and differentiated into cells of each of the germinal layers following in vitro differentiation. The transfer of 2-cell embryos from the 0.1 and 0.3 M cohorts resulted in the birth of live offspring that had normal karyotypes (9/10. When 2-cell embryos from vitrified oocytes underwent vitrification, and were thawed and transferred, live offspring were obtained that exhibited normal karyotypes, with the exception of one offspring who was larger and died at 7 months. We conclude that these studies highlight the importance of the endometrial environment for the maintenance of genetic stability and

  5. Cold Atmospheric Air Plasma Sterilization against Spores and Other Microorganisms of Clinical Interest

    Science.gov (United States)

    Isbary, Georg; Shimizu, Tetsuji; Li, Yang-Fang; Zimmermann, Julia L.; Stolz, Wilhelm; Schlegel, Jürgen; Morfill, Gregor E.; Schmidt, Hans-Ulrich

    2012-01-01

    Physical cold atmospheric surface microdischarge (SMD) plasma operating in ambient air has promising properties for the sterilization of sensitive medical devices where conventional methods are not applicable. Furthermore, SMD plasma could revolutionize the field of disinfection at health care facilities. The antimicrobial effects on Gram-negative and Gram-positive bacteria of clinical relevance, as well as the fungus Candida albicans, were tested. Thirty seconds of plasma treatment led to a 4 to 6 log10 CFU reduction on agar plates. C. albicans was the hardest to inactivate. The sterilizing effect on standard bioindicators (bacterial endospores) was evaluated on dry test specimens that were wrapped in Tyvek coupons. The experimental D23°C values for Bacillus subtilis, Bacillus pumilus, Bacillus atrophaeus, and Geobacillus stearothermophilus were determined as 0.3 min, 0.5 min, 0.6 min, and 0.9 min, respectively. These decimal reduction times (D values) are distinctly lower than D values obtained with other reference methods. Importantly, the high inactivation rate was independent of the material of the test specimen. Possible inactivation mechanisms for relevant microorganisms are briefly discussed, emphasizing the important role of neutral reactive plasma species and pointing to recent diagnostic methods that will contribute to a better understanding of the strong biocidal effect of SMD air plasma. PMID:22582068

  6. Emission spectroscopy of an atmospheric pressure plasma jet operated with air at low frequency

    Science.gov (United States)

    Giuliani, L.; Gallego, J. L.; Minotti, F.; Kelly, H.; Grondona, D.

    2015-03-01

    Low-temperature, high-pressure plasma jets have an extensive use in plasma biology and plasma medicine, such as pathogen deactivation, wound disinfection, stopping of bleeding without damage of healthy tissue, acceleration of wound healing, control of bio-film proliferation, etc. In this work, a spectroscopic characterization of a typical plasma jet, operated in air at atmospheric pressure, is reported. Within the spectrum of wavelengths from 200 to 450 nm all remarkable emissions of N2 were monitored. Spectra of the N2 2nd positive system (C3Πu-B3Πg) emitted in air are the most convenient for plasma diagnostics, since they enable to determine electronic Te, rotational Tr and vibrational Tv temperatures by fitting the experimental spectra with the simulated ones. We used SPECAIR software for spectral simulation and obtained the best fit with all these temperatures about 3500K. The conclusion that all temperatures are equal, and its relatively high value, is consistent with the results of a previous work, where it was found that the experimentally determined electrical characteristic was consistent with the model of a thermal arc discharge, together with a highly collisional cathode sheet.

  7. Increasing lifetime of the plasma channel formed in air using picosecond and nanosecond laser pulses

    Science.gov (United States)

    Narayanan, V.; Singh, V.; Pandey, Pramod K.; Shukla, Neeraj; Thareja, R. K.

    2007-04-01

    We report experiments on a pump-probe configuration to elucidate the formation of a plasma channel by the hydrodynamic evolution of air breakdown in laser focus. A stable air breakdown was produced by focusing a picosecond laser pulse to create a shock driven plasma channel in the laser focus for propagating a nanosecond pulse. A four fold increase in the lifetime of the channel estimated by monitoring the temporal evolution of the fluorescence of a spectral line at 504.5nm of N+ transition 3pS3-3sP03 is reported. Assuming plasma in local thermal equilibrium plasma temperature of ˜8.2eV and an electron density of ˜1.4×1018cm-3 were determined using a Stark broadening of 649.2nm line of NII transition 3dD03-4pD3 in the channel. An enhancement in the electron density of the plasma channel was observed at the 7ns delay of the nanosecond laser pulse relative to the picosecond laser pulse.

  8. Spatial properties of a terahertz beam generated from a two-color air plasma

    DEFF Research Database (Denmark)

    Pedersen, Pernille Klarskov; Wang, Tianwu; Buron, Jonas Christian Due

    2013-01-01

    We present a spatial characterization of terahertz (THz) beams generated from a two-color air plasma under different conditions by measuring full 3D beam profiles using a commercial THz camera. We compare two THz beam profiles emitted from plasmas generated by 35 fs and 100 fs laser pulses......, and show that the spatial properties of the two THz beams do not change significantly. For the THz beam profile generated by the 35 fs pulse, the spatial effect of eliminating the lower frequencies is investigated by implementing two crossed polarizers working as a high-pass filter. We show...

  9. Aerosynthesis: Growth of Vertically-aligned Carbon Nanofibres with Air DC Plasma

    Directory of Open Access Journals (Sweden)

    A. Kodumagulla

    2014-03-01

    Full Text Available Vertically-aligned carbon nanofibres (VACNFs have been synthesized in a mixture of acetone and air using catalytic DC plasma-enhanced chemical vapour deposition. Typically, ammonia or hydrogen is used as an etchant gas in the mixture to remove carbon that otherwise passivates the catalyst surface and impedes growth. Our demonstration of the use of air as the etchant gas opens up the possibility that ion etching could be sufficient to maintain the catalytic activity state during synthesis. It also demonstrates a path toward growing VACNFs in the open atmosphere.

  10. Nanosecond pulsed humid Ar plasma jet in air: shielding, discharge characteristics and atomic hydrogen production

    Science.gov (United States)

    Yatom, Shurik; Luo, Yuchen; Xiong, Qing; Bruggeman, Peter J.

    2017-10-01

    Gas phase non-equilibrium plasmas jets containing water vapor are of growing interest for many applications. In this manuscript, we report a detailed study of an atmospheric pressure nanosecond pulsed Ar  +  0.26% H2O plasma jet. The plasma jet operates in an atmospheric pressure air surrounding but is shielded with a coaxial argon flow to limit the air diffusion into the jet effluent core. The jet impinges on a metal plate electrode and produces a stable plasma filament (transient spark) between the needle electrode in the jet and the metal plate. The stable plasma filament is characterized by spatially and time resolved electrical and optical diagnostics. This includes Rayleigh scattering, Stark broadening of the hydrogen Balmer lines and two-photon absorption laser induced fluorescence (TaLIF) to obtain the gas temperature, the electron density and the atomic hydrogen density respectively. Electron densities and atomic hydrogen densities up to 5 × 1022 m-3 and 2 × 1022 m-3 have been measured. This shows that atomic hydrogen is one of the main species in high density Ar-H2O plasmas. The gas temperature does not exceed 550 K in the core of the plasma. To enable in situ calibration of the H TaLIF at atmospheric pressure a previously published O density calibration scheme is extended to include a correction for the line profiles by including overlap integrals as required by H TaLIF. The line width of H TaLIF, due to collision broadening has the same trend as the neutral density obtained by Rayleigh scattering. This suggests the possibility to use this technique to in situ probe neutral gas densities.

  11. Protection of active implant electronics with organosilicon open air plasma coating for plastic overmolding

    Directory of Open Access Journals (Sweden)

    Zeppenfeld Matthias

    2016-09-01

    Full Text Available To overcome challenges for manufacturing of modern smart medical plastic parts by injection molding, e.g. for active implants, the optimization of the interface between electronics and the polymer component concerning adhesion and diffusion behavior is crucial. Our results indicate that a nano-sized SiOxCyHz layer formed by plasma-enhanced chemical vapour deposition (PE-CVD via open air atmospheric pressure plasma jet (APPJ and by use of a hexamthyldisiloxane (HMDSO precursor can form a non-corrosive, anti-permeable and biocompatible coating. Due to the open air character of the APPJ process an inline coating before overmolding could be an easy applicable method and a promising advancement.

  12. Plasma column and nano-powder generation from solid titanium by localized microwaves in air

    Energy Technology Data Exchange (ETDEWEB)

    Popescu, Simona; Jerby, Eli, E-mail: jerby@eng.tau.ac.il; Meir, Yehuda; Ashkenazi, Dana [Faculty of Engineering, Tel Aviv University, Ramat Aviv 6997801 (Israel); Barkay, Zahava [Wolfson Applied Materials Research Center, Tel Aviv Univ., Ramat Aviv 6997801 (Israel); Mitchell, J. Brian A.; Le Garrec, Jean-Luc [IPR., U.M.R. No. 6251 du C.N.R.S., Université de Rennes I, 35042 Rennes (France); Narayanan, Theyencheri [European Synchrotron Radiation Facility, 38043 Grenoble (France)

    2015-07-14

    This paper studies the effect of a plasma column ejected from solid titanium by localized microwaves in an ambient air atmosphere. Nanoparticles of titanium dioxide (titania) are found to be directly synthesized in this plasma column maintained by the microwave energy in the cavity. The process is initiated by a hotspot induced by localized microwaves, which melts the titanium substrate locally. The molten hotspot emits ionized titanium vapors continuously into the stable plasma column, which may last for more than a minute duration. The characterization of the dusty plasma obtained is performed in-situ by small-angle X-ray scattering (SAXS), optical spectroscopy, and microwave reflection analyses. The deposited titania nanoparticles are structurally and morphologically analyzed by ex-situ optical and scanning-electron microscope observations, and also by X-ray diffraction. Using the Boltzmann plot method combined with the SAXS results, the electron temperature and density in the dusty plasma are estimated as ∼0.4 eV and ∼10{sup 19 }m{sup −3}, respectively. The analysis of the plasma product reveals nanoparticles of titania in crystalline phases of anatase, brookite, and rutile. These are spatially arranged in various spherical, cubic, lamellar, and network forms. Several applications are considered for this process of titania nano-powder production.

  13. Plasma column and nano-powder generation from solid titanium by localized microwaves in air

    Science.gov (United States)

    Popescu, Simona; Jerby, Eli; Meir, Yehuda; Barkay, Zahava; Ashkenazi, Dana; Mitchell, J. Brian A.; Le Garrec, Jean-Luc; Narayanan, Theyencheri

    2015-07-01

    This paper studies the effect of a plasma column ejected from solid titanium by localized microwaves in an ambient air atmosphere. Nanoparticles of titanium dioxide (titania) are found to be directly synthesized in this plasma column maintained by the microwave energy in the cavity. The process is initiated by a hotspot induced by localized microwaves, which melts the titanium substrate locally. The molten hotspot emits ionized titanium vapors continuously into the stable plasma column, which may last for more than a minute duration. The characterization of the dusty plasma obtained is performed in-situ by small-angle X-ray scattering (SAXS), optical spectroscopy, and microwave reflection analyses. The deposited titania nanoparticles are structurally and morphologically analyzed by ex-situ optical and scanning-electron microscope observations, and also by X-ray diffraction. Using the Boltzmann plot method combined with the SAXS results, the electron temperature and density in the dusty plasma are estimated as ˜0.4 eV and ˜1019 m-3, respectively. The analysis of the plasma product reveals nanoparticles of titania in crystalline phases of anatase, brookite, and rutile. These are spatially arranged in various spherical, cubic, lamellar, and network forms. Several applications are considered for this process of titania nano-powder production.

  14. Parameters of the plasma of a dc pulsating discharge in a supersonic air flow

    Energy Technology Data Exchange (ETDEWEB)

    Shibkov, V. M., E-mail: shibkov@phys.msu.ru; Shibkova, L. V.; Logunov, A. A. [Moscow State University, Faculty of Physics (Russian Federation)

    2017-03-15

    A dc discharge in a cold (T = 200 K) supersonic air flow at a static pressure of 200–400 Torr was studied experimentally. The excited unsteady pulsating discharge has the form of a thin plasma channel with a diameter of ≤1 mm, stretched downstream the flow. Depending on the discharge current, the pulsation frequency varies from 800 to 1600 Hz and the electron temperature varies from 8000 to 15000 K.

  15. Potential Industrial Applications of the One Atmosphere Uniform Glow Discharge Plasma (OAUGDP) Operating in Ambient Air

    Science.gov (United States)

    Reece Roth, J.

    2004-11-01

    The majority of industrial plasma processing with glow discharges has been conducted at pressures below 10 torr. This tends to limit applications to high value workpieces as a result of the high capital cost of vacuum systems and the production constraints of batch processing. It has long been recognized that glow discharge plasmas would play a much larger industrial role if they could be generated at one atmosphere. The One Atmosphere Uniform Glow Discharge Plasma (OAUGDP), developed at the University of Tennessee's Plasma Sciences Laboratory, is a non-thermal RF plasma operating on displacement currents with the time-resolved characteristics of a classical low pressure DC normal glow discharge. As a glow discharge, the OAUGDP operates with maximum electrical efficiency at the Stoletow point, where the energy input per ion-electron pair is a minimum [1, 2]. Several interdisciplinary teams have investigated potential applications of the OAUGDP. These teams included collaborators from the UTK Textiles and Nonwovens Development Center (TANDEC), and the Departments of Electrical and Computer Engineering, Microbiology, and Food Science and Technology, as well as the NASA Langley Research Center. The potential applications of the OAUGDP have all been at one atmosphere and room temperature, using air as the working gas. These applications include sterilizing medical and dental equipment; sterilizable air filters to deal with the "sick building syndrome"; removal of soot from Diesel engine exhaust; subsonic plasma aerodynamic effects, including flow re-attachment to airfoils and boundary layer modification; electrohydrodynamic (EDH) flow control of working gases; increasing the surface energy of materials; improving the adhesion of paints and electroplated layers: improving the wettability and wickability of fabrics; stripping of photoresist; and plasma deposition and directional etching of potential microelectronic relevance. [1] J. R. Roth, Industrial Plasma Engineering

  16. Influence of metallic vapours on the properties of air thermal plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Cressault, Y; Hannachi, R; Teulet, Ph; Gleizes, A [LAPLACE - UMR CNRS 5213, Universite de Toulouse 3, 118 route de Narbonne, 31062 Toulouse Cedex 9 (France); Gonnet, J-P; Battandier, J-Y [Schneider Electric, Innovation Division, 38TEC/T3 Plant, 37 Quai Paul-Louis Merlin F38000 Grenoble (France)], E-mail: yann.cressault@laplace.univ-tlse.fr

    2008-08-01

    This paper deals with properties of air thermal plasmas containing vapours of iron, silver or copper. The plasma is supposed to be in local thermodynamic equilibrium, for temperatures ranging from 2000 to 30 000 K. First, the equilibrium composition and thermodynamic properties are presented. Then, the radiative properties are calculated using the method of the net emission coefficient. Finally, the viscosity, electrical and thermal conductivities are calculated using the method of Chapman-Enskog. For all mixtures, mole fractions have been used. The results are computed for various values of pressure, plasma size and proportions of vapours. The influence of metallic vapour is important on the electrical conductivity and on the radiation, even at low concentration. All the metallic vapours present a similar behaviour except iron, which has a stronger radiation emission than the other components.

  17. Coal gasification in steam and air medium under plasma conditions. A preliminary study

    Energy Technology Data Exchange (ETDEWEB)

    Qiu, Jieshan; He, Xiaojun; Sun, Tianjun; Zhao, Zongbin; Zhou, Ying [Carbon Research Laboratory, Department of Materials Science and Chemical Engineering, Dalian University of Technology, 158 Zhongshan Road, P.O. Box 49, Dalian 116012 (China); Guo, Shuhong; Zhang, Jialiang; Ma, Tengcai [State Key Laboratory for Materials Modification by Laser, Ion and Electron Beams, Dalian University of Technology, Dalian 116024 (China)

    2004-07-15

    The gasification of coal under steam and air plasma conditions at atmospheric pressure was investigated in a tube-type setup with an aim of producing synthesis gas. The plasma was diagnosed by optical emission spectroscopy (OES) and the synthesis gas was analyzed by gas chromatography (GC). It has been found that the content of H{sub 2} and CO in gas increases with increasing the arc input power, and passes through a maximum with the increase of current in electromagnetic coil. This is also the case for the variation trend of CO content in gas with the increase of the feeding rate of coal, but the H{sub 2} content in gas decreases as the feeding rate of coal increases. Under the experimental conditions tested, the content of H{sub 2}+CO in the gas could reach 75% in volume with CO{sub 2} being less than 3.0 vol.%. The OES diagnosis reveals that CO{sup +} ion and CH radical are present in the plasma and the variation trend of their intensities is, to some degree, in accordance with the variation trend of CO content in the gas, indicating that the CO{sup +} ion and CH radical are the precursors or origins of CO species in the gas. The preliminary results presented here demonstrate that the gasification of coal under steam and air plasma conditions might become a new approach for production of synthesis gas.

  18. A new concept of high flow rate non-thermal plasma reactor for air treatment

    Energy Technology Data Exchange (ETDEWEB)

    Goujard, V.; Tatibouet, J.M. [Univ. de Poitiers, Poitiers (France). Centre national de la recherche scientifique, Laboratoire de Catalyse en Chimie Organique

    2010-07-01

    Although several non-thermal plasma reactors have been tested for air treatment at the laboratory scale, up-scaling to pilot or industrial scale remains a challenge because several parameters must be considered, such as hydrodynamic behaviour, maximum voltage in an industrial environment, and maintenance of the system. This paper presented a newly developed reactor which consists to a DBD plasma generated on individual supports that could be directly inserted in gas pipes where air flow must be treated. Elimination of 40 percent of 15 ppm of propene was obtained with a energy density as low as 10 J/L. The propene conversion increased when a manganese oxide based catalyst was used because the ozone produced by the plasma was used as an as an oxidant. A simple model of the plasma-catalyst reactor behaviour showed that more than 90 percent of propene conversion can be expected for an input energy density of 10 J/L and residual ozone concentration less than 100 ppb.

  19. Evaluation of an international, perpetual, and retrievable facility for storage of vitrified radioactive waste

    Energy Technology Data Exchange (ETDEWEB)

    Libby, L.M.; Whipple, C.G.; Wurtele, M.G.

    1982-10-01

    It is technically feasible to site a retrievable but permanent surface storage facility for vitrified radioactive wastes in the northwestern Egyptian desert. Present-day commercial vitrification plants are in England and France and produce glass cylinders in the shape of an annulus, about 9 ft high, clad in a stainless steel can, containing about 25% of fission product and actinide oxides, weighing about 10 tonnes, having a volume of about 70 ft/sup 3/, releasing about 1.8 X 10/sup 5/ Btu heat/h. The high-level waste (HLW) glass cylinders, in lead shipping casks, are to be shipped to European ports by truck, sent to Mersa Matruh on the Egyptian coast, about ten at a time in small barges, then offloaded and sent by train a short distance inland to the site. The storage facility envisaged at the site is a concrete-walled round house with a radial crane, equipped with recanning facilities in case of breakage of stainless steel canisters, with a shop for repair of the train as needed, and with a turntable for the engine. Cooling is provided by natural air draft resulting from the canister surface temperature of about 100/sup 0/C. If needed, backup cooling is provided by equipment for forced-air drafts and by tanks of water. The canister arrangement is that produced by coaxial vertical stacking; horizontal coaxial arrangements are yet to be analyzed. The site chosen is exposed hard rock close to the Mediterranean in the northwest corner of the Egyptian desert. Groundwater is found at about 100 m. The rainfall is about 4 in./yr so that flash floods sometimes occur and surface drains are needed. Meteorology, seismicity, agriculture, and wildlife are all favorable factors, and plane studies show no thermal or radioactive threat.

  20. Study of the expansion characteristics of a pulsed plasma jet in air

    Science.gov (United States)

    Zhao, Xuewei; Yu, Yonggang; Mang, Shanshan; Xue, Xiaochun

    2017-04-01

    In the background of electrothermal-chemical (ETC) emission, an investigation has been conducted on the characteristics of a freely expanding pulsed plasma jet in air. The evolutionary process of the plasma jet is experimentally investigated using a piezoelectric pressure sensor and a digital high-speed video system. The variation relation in the extended volume, axial displacement and radial displacement of the pulsed plasma jet in atmosphere with time under different discharge voltages and jet breaking pressures is obtained. Based on experiments, a two-dimensional axisymmetric unsteady model is established to analyze the characteristics of the two-phase interface and the variation of flow-field parameters resulting from a pulsed plasma jet into air at a pressure of 1.5-3.5 MPa under three nozzle diameters (3 mm, 4 mm and 5 mm, respectively). The images of the plasma jet reveal a changing shape process, from a quasi-ellipsoid to a conical head and an elongated cylindrical tail. The axial displacement of the jet is always larger than that along the radial direction. The extended volume reveals a single peak distribution with time. Compared to the experiment, the numerical simulation agrees well with the experimental data. The parameters of the jet field mutate at the nozzle exit with a decrease in the parameter pulse near the nozzle, and become more and more gradual and close to environmental parameters. Increasing the injection pressure and nozzle diameter can increase the parameters of the flow field such as the expansion volume of the pulsed plasma jet, the size of the Mach disk and the pressure. In addition, the turbulent mixing in the expansion process is also enhanced.

  1. Enhancement of corrosion resistance for plasma nitrided AISI 4140 steel by plain air plasma post-oxidizing

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Jiqiang; Liu, Han; Ye, Xuemei [Jiangsu Key Laboratory of Materials Surface Technology, Changzhou University, Changzhou 213164 (China); Chai, Yating [Materials Research and Education Center, Auburn University, AL 36849 (United States); Hu, Jing, E-mail: jinghoo@126.com [Jiangsu Key Laboratory of Materials Surface Technology, Changzhou University, Changzhou 213164 (China); Materials Research and Education Center, Auburn University, AL 36849 (United States)

    2015-05-25

    Highlights: • Plain air was primarily used for plasma post-oxidation for AISI 4140 steel. • A thin iron oxide layer composed of Fe{sub 3}O{sub 4} to Fe{sub 2}O{sub 3} was formed on top of the compound layer. • The ratio of Fe{sub 3}O{sub 4} to Fe{sub 2}O{sub 3} was closely related to the post-oxidizing conditions. • Post-oxidizing at 673 K for 60 min brought out highest ratio of Fe{sub 3}O{sub 4} to Fe{sub 2}O{sub 3} and optimum corrosion resistance. - Abstract: Plasma post-oxidizing was conducted immediately after plasma nitriding in the same equipment for AISI 4140 steel, and plain air was used as the oxygen bearing gas. The cross-sectional microstructures of the treated samples were observed by optical metallography and scanning electron microcopy (SEM), and the thickness of compound layer was measured accordingly. The phases were determined by X-ray diffraction (XRD), corrosion resistance was evaluated by electrochemical polarization, and the surface morphology before and after polarization test was also observed by SEM. Meanwhile, standard Gibbs free energy of the oxidation reactions existed in Fe–O system was calculated. The results show that a thin iron oxide layer composed of magnetite (Fe{sub 3}O{sub 4}) and hematite (Fe{sub 2}O{sub 3}) is formed on top of the compound layer during plasma post-oxidizing process, and the ratio of magnetite (Fe{sub 3}O{sub 4}) to hematite (Fe{sub 2}O{sub 3}) is depended on plasma post-oxidizing temperature and time. Highest ratio of Fe{sub 3}O{sub 4} to Fe{sub 2}O{sub 3} is obtained while post-oxidizing at 673 K for 60 min due to lower standard Gibbs free energy and appropriate forming rate for the formation of Fe{sub 3}O{sub 4} at this temperature. The thin oxide layer brings out significant enhancement of corrosion resistance, especially at higher ratios of Fe{sub 3}O{sub 4} to Fe{sub 2}O{sub 3}, due to the dense and adherent characteristic of Fe{sub 3}O{sub 4} oxide. Surface images of the post-oxidizing specimen

  2. Evolution of the THz Beam Profile from a Two-Color Air Plasma Through a Beam Waist

    DEFF Research Database (Denmark)

    Strikwerda, Andrew; Pedersen, Pernille Klarskov; Jepsen, Peter Uhd

    2013-01-01

    We experimentally measure the profile of a THz beam generated by a two-color air plasma as it passes through a beam waist, and show that it can be approximated as a Bessel-Gauss beam.......We experimentally measure the profile of a THz beam generated by a two-color air plasma as it passes through a beam waist, and show that it can be approximated as a Bessel-Gauss beam....

  3. First Breakthrough for Future Air-Breathing Magneto-Plasma Propulsion Systems

    CERN Document Server

    Goksel, Berkant

    2016-01-01

    A new breakthrough in jet propulsion technology since the invention of the jet engine is achieved. The first critical tests for future air-breathing magneto-plasma propulsion systems have been successfully completed. In this regard, it is also the first time that a pinching dense plasma focus discharge could be ignited at one atmosphere and driven in pulse mode using very fast, nanosecond electrostatic excitations to induce self-organized plasma channels for ignition of the propulsive main discharge. Depending on the capacitor voltage (200-600 V) the energy input at one atmosphere varies from 52-320 J/pulse corresponding to impulse bits from 1.2-8.0 mNs. Such a new pulsed plasma propulsion system driven with one thousand pulses per second would already have thrust-to-area ratios (50-150 kN/m2) of modern jet engines. An array of thrusters could enable future aircrafts and airships to start from ground and reach altitudes up to 50km and beyond. The needed high power could be provided by future compact plasma fu...

  4. Propagation of atmospheric pressure helium plasma jet into ambient air at laminar gas flow

    Science.gov (United States)

    Pinchuk, M.; Stepanova, O.; Kurakina, N.; Spodobin, V.

    2017-05-01

    The formation of an atmospheric pressure plasma jet (APPJ) in a gas flow passing through the discharge gap depends on both gas-dynamic properties and electrophysical parameters of the plasma jet generator. The paper presents the results of experimental and numerical study of the propagation of the APPJ in a laminar flow of helium. A dielectric-barrier discharge (DBD) generated inside a quartz tube equipped with a coaxial electrode system, which provided gas passing through it, served as a plasma source. The transition of the laminar regime of gas flow into turbulent one was controlled by the photography of a formed plasma jet. The corresponding gas outlet velocity and Reynolds numbers were revealed experimentally and were used to simulate gas dynamics with OpenFOAM software. The data of the numerical simulation suggest that the length of plasma jet at the unvarying electrophysical parameters of DBD strongly depends on the mole fraction of ambient air in a helium flow, which is established along the direction of gas flow.

  5. Contact-free inactivation of Candida albicans biofilms by cold atmospheric air plasma.

    Science.gov (United States)

    Maisch, Tim; Shimizu, Tetsuji; Isbary, Georg; Heinlin, Julia; Karrer, Sigrid; Klämpfl, Tobias G; Li, Yang-Fang; Morfill, Gregor; Zimmermann, Julia L

    2012-06-01

    Candida albicans is one of the main species able to form a biofilm on almost any surface, causing both skin and superficial mucosal infections. The worldwide increase in antifungal resistance has led to a decrease in the efficacy of standard therapies, prolonging treatment time and increasing health care costs. Therefore, the aim of this work was to demonstrate the applicability of atmospheric plasma at room temperature for inactivating C. albicans growing in biofilms without thermally damaging heat-sensitive materials. This so-called cold atmospheric plasma is produced by applying high voltage to accelerate electrons, which ionize the surrounding air, leading to the production of charged particles, reactive species, and photons. A newly developed plasma device was used, which exhibits a large plasma-generating surface area of 9 by 13 cm (117 cm(2)). Different time points were selected to achieve an optimum inactivation efficacy range of ≥3 log(10) to 5 log(10) reduction in CFU per milliliter, and the results were compared with those of 70% ethanol. The results obtained show that contact-free antifungal inactivation of Candida biofilms by cold atmospheric plasma is a promising tool for disinfection of surfaces (and items) in both health care settings and the food industry, where ethanol disinfection should be avoided.

  6. Atmospheric pressure He-air plasma jet: Breakdown process and propagation phenomenon

    Directory of Open Access Journals (Sweden)

    Asma Begum

    2013-06-01

    Full Text Available In this paper He-discharge (plasma jet/bullet in atmospheric pressure air and its progression phenomenon has been studied experimentally using ICCD camera, optical emission spectroscopy (OES and calibrated dielectric probe measurements. The repetitive nanosecond pulse has applied to a plasma pencil to generate discharge in the helium gas channel. The discharge propagation speed was measured from the ICCD images. The axial electric field distribution in the plasma jet is inferred from the optical emission spectroscopic data and from the probe measurement. The correlation between the jet velocities, jet length with the pulse duration is established. It shows that the plasma jet is not isolated from the input voltage along its propagation path. The discharge propagation speed, the electron density and the local and average electric field distribution along the plasma jet axis predicted from the experimental results are in good agreement with the data predicted by numerical simulation of the streamer propagation presented in different literatures. The ionization phenomenon of the discharge predicts the key ionization parameters, such as speed, peak electric field in the front, and electron density. The maximum local electric field measured by OES is 95 kV/cm at 1.3 cm of the jet axis, and average EF measured by probe is 24 kV/cm at the same place of the jet. The average and local electron density estimated are in the order of 1011 cm-3 and it reaches to the maximum of 1012 cm-3.

  7. Apparent Surface Free Energy of Polymer/Paper Composite Material Treated by Air Plasma

    Directory of Open Access Journals (Sweden)

    Konrad Terpiłowski

    2017-01-01

    Full Text Available Surface plasma treatment consists in changes of surface properties without changing internal properties. In this paper composite polymer/paper material is used for production of packaging in cosmetic industry. There are problems with bonding this material at the time of packaging production due to its properties. Composite surface was treated by air plasma for 1, 10, 20, and 30 s. The advancing and receding contact angles of water, formamide, and diiodomethane were measured using both treated and untreated samples. Apparent surface free energy was estimated using the hysteresis (CAH and Van Oss, Good, Chaudhury approaches (LWAB. Surface roughness was investigated using optical profilometry and identification of after plasma treatment emerging chemical groups was made by means of the XPS (X-ray photoelectron spectroscopy technique. After plasma treatment the values of contact angles decreased which is particularly evident for polar liquids. Apparent surface free energy increased compared to that of untreated samples. Changes of energy value are due to the electron-donor parameter of energy. This parameter increases as a result of adding polar groups at the time of surface plasma activation. Changes of surface properties are combination of increase of polar chemical functional groups, increase on the surface, and surface roughness increase.

  8. Combined laser induced ignition and plasma spectroscopy: Fundamentals and application to a hydrogen-air combustor

    Energy Technology Data Exchange (ETDEWEB)

    Zimmer, L. [Aeroengine Technology Center, Japan Aerospace Exploration Agency, 7-44-1 Jindaiji-Higashi Chofu, 182-8522 Tokyo (Japan)], E-mail: laurent.zimmer@em2c.ecp.fr; Okai, K. [Aeroengine Technology Center, Japan Aerospace Exploration Agency, 7-44-1 Jindaiji-Higashi Chofu, 182-8522 Tokyo (Japan)], E-mail: okai@chofu.jaxa.jp; Kurosawa, Y. [Clean engine team, Japan Aerospace Exploration Agency, 7-44-1 Jindaiji-Higashi Chofu, 182-8522 Tokyo (Japan)], E-mail: kuro@chofu.jaxa.jp

    2007-12-15

    Combined Laser Induced Ignition and Plasma Spectroscopy (LI2PS) has the potential to give the exact local composition of a mixture at the ignition point and at the ignition time. However, as different laser energies are required to ignite a particular mixture as function of space, the typical approach using two power meters to calibrate the plasma spectroscopy measurement is not well suited. Furthermore, LI2PS requires single shot measurements and therefore high accuracy. In this paper, a novel calibration scheme is presented for application of Laser Induced Plasma Spectroscopy (LIPS) to gaseous analyses. Numerical simulations of air spectra are used to show that species emission can be used directly from the broadband spectra to determine the plasma conditions. The ratio of nitrogen emission around 744 nm and around 870 nm is found to be a sensitive indication of temperature in the emission ranging from 700 to 890 nm. Comparisons with experimental spectra show identical tendencies and validate the findings of the simulations. This approach is used in a partially-premixed hydrogen-air burner. First, helium is used instead of hydrogen. After an explanation of timing issue related to LIPS, it is shown that the calibration required depends only on nitrogen excitation and nitrogen-hydrogen ratio, without the need to know the deposited power. Measurements of the fuel distribution as function of injection momentum and spatial localization are reported. To illustrate the use of such a single shot approach, combined laser ignition and plasma spectroscopy is proposed. In this case, the calibration is based on hydrogen excitation and hydrogen-oxygen and hydrogen-nitrogen ratio. Results obtained with LI2PS show that ignition is successful only for high power and relatively high hydrogen concentration compared to the local mean. It is expected that LI2PS will become an important tool when dealing with partially-premixed or diffusion flame ignition.

  9. Novel fragmentation model for pulverized coal particles gasification in low temperature air thermal plasma

    Directory of Open Access Journals (Sweden)

    Jovanović Rastko D.

    2016-01-01

    Full Text Available New system for start-up and flame support based on coal gasification by low temperature air thermal plasma is planned to supplement current heavy oil system in Serbian thermal power plants in order to decrease air pollutions emission and operational costs. Locally introduced plasma thermal energy heats up and ignites entrained coal particles, thus starting chain process which releases heat energy from gasified coal particles inside burner channel. Important stages during particle combustion, such as particle devolatilisation and char combustion, are described with satisfying accuracy in existing commercial CFD codes that are extensively used as powerful tool for pulverized coal combustion and gasification modeling. However, during plasma coal gasification, high plasma temperature induces strong thermal stresses inside interacting coal particles. These stresses lead to “thermal shock” and extensive particle fragmentation during which coal particles with initial size of 50-100 m disintegrate into fragments of at most 5-10 m. This intensifies volatile release by a factor 3-4 and substantially accelerates the oxidation of combustible matter. Particle fragmentation, due to its small size and thus limited influence on combustion process is commonly neglected in modelling. The main focus of this work is to suggest novel approach to pulverized coal gasification under high temperature conditions and to implement it into commercial comprehensive code ANSYS FLUENT 14.0. Proposed model was validated against experimental data obtained in newly built pilot scale D.C plasma burner test facility. Newly developed model showed very good agreement with experimental results with relative error less than 10%, while the standard built-in gasification model had error up to 25%.

  10. Kinetic mechanism of molecular energy transfer and chemical reactions in low-temperature air-fuel plasmas.

    Science.gov (United States)

    Adamovich, Igor V; Li, Ting; Lempert, Walter R

    2015-08-13

    This work describes the kinetic mechanism of coupled molecular energy transfer and chemical reactions in low-temperature air, H2-air and hydrocarbon-air plasmas sustained by nanosecond pulse discharges (single-pulse or repetitive pulse burst). The model incorporates electron impact processes, state-specific N(2) vibrational energy transfer, reactions of excited electronic species of N(2), O(2), N and O, and 'conventional' chemical reactions (Konnov mechanism). Effects of diffusion and conduction heat transfer, energy coupled to the cathode layer and gasdynamic compression/expansion are incorporated as quasi-zero-dimensional corrections. The model is exercised using a combination of freeware (Bolsig+) and commercial software (ChemKin-Pro). The model predictions are validated using time-resolved measurements of temperature and N(2) vibrational level populations in nanosecond pulse discharges in air in plane-to-plane and sphere-to-sphere geometry; temperature and OH number density after nanosecond pulse burst discharges in lean H(2)-air, CH(4)-air and C(2)H(4)-air mixtures; and temperature after the nanosecond pulse discharge burst during plasma-assisted ignition of lean H2-mixtures, showing good agreement with the data. The model predictions for OH number density in lean C(3)H(8)-air mixtures differ from the experimental results, over-predicting its absolute value and failing to predict transient OH rise and decay after the discharge burst. The agreement with the data for C(3)H(8)-air is improved considerably if a different conventional hydrocarbon chemistry reaction set (LLNL methane-n-butane flame mechanism) is used. The results of mechanism validation demonstrate its applicability for analysis of plasma chemical oxidation and ignition of low-temperature H(2)-air, CH(4)-air and C(2)H(4)-air mixtures using nanosecond pulse discharges. Kinetic modelling of low-temperature plasma excited propane-air mixtures demonstrates the need for development of a more accurate

  11. Influence of air pressure on the performance of plasma synthetic jet actuator

    Science.gov (United States)

    Li, Yang; Jia, Min; Wu, Yun; Li, Ying-hong; Zong, Hao-hua; Song, Hui-min; Liang, Hua

    2016-09-01

    Plasma synthetic jet actuator (PSJA) has a wide application prospect in the high-speed flow control field for its high jet velocity. In this paper, the influence of the air pressure on the performance of a two-electrode PSJA is investigated by the schlieren method in a large range from 7 kPa to 100 kPa. The energy consumed by the PSJA is roughly the same for all the pressure levels. Traces of the precursor shock wave velocity and the jet front velocity vary a lot for different pressures. The precursor shock wave velocity first decreases gradually and then remains at 345 m/s as the air pressure increases. The peak jet front velocity always appears at the first appearance of a jet, and it decreases gradually with the increase of the air pressure. A maximum precursor shock wave velocity of 520 m/s and a maximum jet front velocity of 440 m/s are observed at the pressure of 7 kPa. The averaged jet velocity in one period ranges from 44 m/s to 54 m/s for all air pressures, and it drops with the rising of the air pressure. High velocities of the precursor shock wave and the jet front indicate that this type of PSJA can still be used to influence the high-speed flow field at 7 kPa. Project supported by the National Natural Science Foundation of China (Grant Nos. 51407197, 51522606, 51336011, 91541120, and 11472306).

  12. Kinetic studies of NO formation in pulsed air-like low-pressure dc plasmas

    Science.gov (United States)

    Hübner, M.; Gortschakow, S.; Guaitella, O.; Marinov, D.; Rousseau, A.; Röpcke, J.; Loffhagen, D.

    2016-06-01

    The kinetics of the formation of NO in pulsed air-like dc plasmas at a pressure of 1.33 mbar and mean currents between 50 and 150 mA of discharge pulses with 5 ms duration has been investigated both experimentally and by self-consistent numerical modelling. Using time-resolved quantum cascade laser absorption spectroscopy, the densities of NO, NO2 and N2O have been measured in synthetic air as well as in air with 0.8% of NO2 and N2O, respectively. The temporal evolution of the NO density shows four distinct phases during the plasma pulse and the early afterglow in the three gas mixtures that were used. In particular, a steep density increase during the ignition phase and after termination of the discharge current pulse has been detected. The NO concentration has been found to reach a constant value of 0.57× {{10}14}~\\text{molecules}~\\text{c}{{\\text{m}}-3} , 1.05× {{10}14}~\\text{molecules}~\\text{c}{{\\text{m}}-3} , and 1.3× {{10}14}~\\text{molecules}~\\text{c}{{\\text{m}}-3} for mean plasma currents of 50 mA, 100 mA and 150 mA, respectively, in the afterglow. The measured densities of NO2 and N2O in the respective mixture decrease exponentially during the plasma pulse and remain almost constant in the afterglow, especially where the admixture of NO2 has a remarkable impact on the NO production during the ignition. The numerical results of the coupled solution of a set of rate equations for the various heavy particles and the time-dependent Boltzmann equation of the electrons agree quite well with the experimental findings for the different air-like plasmas. The main reaction processes have been analysed on the basis of the model calculations and the remaining differences between the experiment and modelling especially during the afterglow are discussed.

  13. Development of Polysulfone Hollow Fiber Porous Supports for High Flux Composite Membranes: Air Plasma and Piranha Etching

    OpenAIRE

    Ilya Borisov; Anna Ovcharova; Danila Bakhtin; Stepan Bazhenov; Alexey Volkov; Rustem Ibragimov; Rustem Gallyamov; Galina Bondarenko; Rais Mozhchil; Alexandr Bildyukevich; Vladimir Volkov

    2017-01-01

    For the development of high efficiency porous supports for composite membrane preparation, polysulfone (PSf) hollow fiber membranes (outer diameter 1.57 mm, inner diameter 1.12 mm) were modified by air plasma using the low temperature plasma treatment pilot plant which is easily scalable to industrial level and the Piranha etch (H2O2 + H2SO4). Chemical and plasma modification affected only surface layers and did not cause PSf chemical structure change. The modifications led to surface roughne...

  14. Effects of aging on the adhesive properties of poly(lactic acid) by atmospheric air plasma treatment

    OpenAIRE

    Jordá Vilaplana, Amparo; Sánchez Nacher, Lourdes; García Sanoguera, David; Carbonell Verdú, Alfredo; Ferri Azor, José Miguel

    2016-01-01

    The aim of this study was to analyze the durability of a plasma treatment on the surface of poly(lactic acid) (PLA). We used atmospheric-plasma treatment with air to improve the wettability of PLA by evaluating the aging effect under controlled conditions of relative humidity (RH) and temperature (25% RH and 258C). We studied the durability of the atmospheric-plasma treatment by measuring the contact angle, calculating the surface energy, and observing changes in the resistance of th...

  15. Effect of non-thermal air atmospheric pressure plasma jet treatment on gingival wound healing

    Science.gov (United States)

    Lee, Jung-Hwan; Choi, Eun-Ha; Kim, Kwang-Mahn; Kim, Kyoung-Nam

    2016-02-01

    Non-thermal atmospheric pressure plasmas have been applied in the biomedical field for the improvement of various cellular activities. In dentistry, the healing of gingival soft tissue plays an important role in health and aesthetic outcomes. While the biomedical application of plasma has been thoroughly studied in dentistry, a detailed investigation of plasma-mediated human gingival fibroblast (HGF) migration for wound healing and its underlying biological mechanism is still pending. Therefore, the aim of this study is to apply a non-thermal air atmospheric pressure plasma jet (NTAAPPJ) to HGF to measure the migration and to reveal the underlying biological mechanisms involved in the migration. After the characterization of NTAAPPJ by optical emission spectroscopy, the adherent HGF was treated with NTAAPPJ or air with a different flow rate. Cell viability, lipid peroxidation, migration, intracellular reactive oxygen species (ROS), and the expression of migration-related genes (EGFR, PAK1, and MAPK3) were investigated. The level of statistical significance was set at 0.05. NTAAPPJ and air treatment with a flow rate of 250-1000 standard cubic centimetres per minute (sccm) for up to 30 s did not induce significant decreases in cell viability or membrane damage. A significant increase in the migration of mitomycin C-treated HGF was observed after 30 s of NTAAPPJ treatment compared to 30 s air-only treatment, which was induced by high levels of intracellular reactive oxygen species (ROS). An increase in migration-related gene expression and EGFR activation was observed following NTAAPPJ treatment in an air flow rate-dependent manner. This is the first report that NTAAPPJ treatment induces an increase in HGF migration without changing cell viability or causing membrane damage. HGF migration was related to an increase in intracellular ROS, changes in the expression of three of the migration-related genes (EGFR, PAK1, and MAPK1), and EGFR activation. Therefore

  16. Field demonstration and commercialization of silent discharge plasma hazardous air pollutant control technology

    Energy Technology Data Exchange (ETDEWEB)

    Rosocha, L.A.; Coogan, J.J.; Korzekwa, R.A.; Secker, D.A. [Los Alamos National Lab., NM (United States); Reimers, R.F.; Herrmann, P.G.; Chase, P.J.; Gross, M.P. [High Mesa Technologies LLC, Santa Fe, NM (United States)]|[High Mesa Technologies LLC, Irvine, CA (United States); Jones, M.R. [Electric Power Research Inst., Palo Alto, CA (United States)

    1996-07-01

    Silent electrical discharge plasma (dielectric barrier) reactors can decompose gas-phase pollutants by free-radical attack or electron-induced fragmentation. The radicals or electrons are produced by the large average volume nonthermal plasmas generated in the reactor. In the past decade, the barrier configuration has attracted attention for destroying toxic chemical agents for the military, removing harmful greenhouse gases, and treating other environmentally- hazardous chemical compounds. At the Los Alamos National Laboratory, we have been studying the silent discharge plasma (SDP) for processing gaseous-based hazardous chemicals for approximately five years. The key objective is to convert hazardous or toxic chemicals into non-hazardous compounds or into materials which are more easily managed. The main applications have been for treating off-gases from thermal treatment units, and for abating hazardous air-pollutant emissions (e.g., industrial air emissions, vapors extracted from contaminated soil or groundwater). In this paper, we will summarize the basic principles of SDP processing, discuss illustrative applications of the technology, and present results from small-scale field tests that are relevant to our commercialization effort.

  17. Fresh and vitrified bovine preantral follicles have different nutritional requirements during in vitro culture.

    Science.gov (United States)

    Castro, S V; Carvalho, A A; Silva, C M G; Santos, F W; Campello, C C; Figueiredo, J R; Rodrigues, A P R

    2014-12-01

    The aim of this study was to compare the efficiency of different media for the in vitro culturing of fresh and vitrified bovine ovarian tissues. Fragments of the ovarian cortex were subjected to vitrification and histological and viability analyses or were immediately cultured in vitro using the alfa minimum essential medium, McCoy's 5A medium (McCoy), or medium 199 (M199). Samples of different culture media were collected on days 1 (D1) and 5 (D5) for quantification of reactive oxygen species and for hormonal assays. In non-vitrified (i.e., fresh) ovarian tissue cultures, the percentage of morphologically normal follicles was significantly greater than that recorded for the other media (e.g., M199). In the case of previously vitrified tissues, the McCoy medium was significantly superior to the other media in preserving follicular morphology up until the last culture day (i.e., D5), thus maintaining a similar percentage from D1 to D5. Reactive oxygen species levels were higher in D1 vitrified cultured tissues, but there were no differences in the levels among the three media after 5 days. The hormonal assays showed that in the case of previously vitrified tissues, at D5, progesterone levels increased on culture in the M199 medium and estradiol levels increased on culture in the McCoy medium. In conclusion, our results indicate that the use of M199 would be recommended for fresh tissue cultures and of McCoy for vitrified tissue cultures.

  18. Experimental and theoretical study of an atmospheric air plasma-jet

    Science.gov (United States)

    Xaubet, M.; Giuliani, L.; Grondona, D.; Minotti, F.

    2017-01-01

    In this work, we present an experimental and theoretical study of a low frequency, atmospheric plasma-jet discharge in air. Voltage-current characteristics and spectroscopic data were experimentally obtained, and a theoretical model developed to gain information of different aspects of the discharge. The discharge is modeled as a cathode layer with different mechanisms of electron emission and a main discharge channel that includes the most important kinetic reactions and species. From the electric measurements, it is determined that high electric field magnitudes are attained in the main channel, depending on the gas flow rate. Using the voltage-current characteristics as an input, the model allows to determine the plasma state in the discharge, including electron, gas, and molecular nitrogen vibrational temperatures. The model also allows to infer the mechanisms of secondary electron emission that sustain the discharge.

  19. Open air plasma deposited antimicrobial SiOx/TiOx composite films for biomedical applications

    Directory of Open Access Journals (Sweden)

    Rapp Christin

    2016-09-01

    Full Text Available Open air atmospheric pressure plasma jet (APPJ enhanced chemical vapour deposition process was used to deposit biocompatible SiOx/TiOx composite coatings. The as deposited films are hydrophilic and show visible light induced photocatalytic effect, which is a consequence of the formation of defects in the TiOx structure due to the plasma process. This photocatalytic effect was verified by the demonstration of an antimicrobial effect under visible light on E. coli as well as by degradation of Rhodamine B. The films are non-cytotoxic as shown by the cytocompatibility tests. The films are conductive to cell growth and are stable in DMEM and isopropanol. The structural evaluation using SEM, EDS and XPS shows a dispersion of TiOx phase in a SiOxCyHz matrix. These analyses were used to correlate the structure-property relationship of the composite coating.

  20. Nanosecond pulsed dielectric barrier discharge plasma-catalytic removal of HCHO in humid air

    Science.gov (United States)

    Zhang, Shuai; Wang, Wenchun; Zhang, Li; Zhao, Zilu; Yang, Dezheng

    2017-05-01

    Non-thermal plasma (NTP) has been regarded as a promising method for the removal of a wide range of low concentration volatile organic compounds (VOCs). In this paper, nanosecond pulsed and alternating current dielectric barrier discharge plasmas synergistic catalyst are utilized for removal of formaldehyde (HCHO) in humid air. Working gas is 1% H2O/21% O2/78% N2 with 154 ppm HCHO over total flow rate of 50 mL/min. Specific energy density (SED) are 32.5 JL-1, 35.8 JL-1 and 1069.2 JL-1 at power consumption of 0.325 W, 0.3 W, 8.9 W for removal of 67%, 63.8% and 73.8% HCHO when using bipolar nanosecond pulsed, unipolar nanosecond pulsed and AC dielectric barrier discharge (DBD) plasma, respectively. The removal efficiencies of HCHO using nanosecond pulsed DBD plasma increase approximately 10 20% when the packed-bed Al2O3 pellets exist and can reach up to almost 100% when TiO2 nanoparticles are used while the effect of CeO2 nanoparticles is a bit poor. Analysis indicate that OH radical and O atom play main role for removal HCHO and the gas temperature is a significant factor for its influence on rate constants of HCHO with active particles.

  1. Diffuse plasma treatment of polyamide 66 fabric in atmospheric pressure air

    Science.gov (United States)

    Li, Lee; Peng, Ming-yang; Teng, Yun; Gao, Guozhen

    2016-01-01

    The polyamide 66 (PA66) fabrics are hard to be colored or glued in industrial production due to the poor hydrophily. Diffuse plasma is a kind of non-thermal plasma generated at atmospheric pressure in air. This paper proposes that large-scale diffuse plasma generated between wire electrodes can be employed for improving the hydrophily of PA66 fabrics. A repetitive nanosecond-pulse diffuse-discharge reactor using a cylindrical wire electrode configuration is presented, which can generate large-scale non-thermal plasmas steadily at atmospheric pressure without any barrier dielectric. Then the reactor is used to treat PA66 fabrics in different discharge conditions. The hydrophilicity property of modified PA66 is measured by wicking test method. The modified PA66 is also analyzed by atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS) to prove the surface changes in physical microstructure and chemical functional groups, respectively. What's more, the effects of treatment time and treatment frequency on surface modification are investigated and discussed.

  2. The different effects of oxygen and air DBD plasma byproducts on the degradation of methyl violet 5BN.

    Science.gov (United States)

    Chen, Guangliang; Zhou, Mingyan; Chen, Shihua; Chen, Wenxing

    2009-12-30

    Through a novel design of the dielectric barrier discharge (DBD) plasma plume used in fabric-fiber surface modification, its discharge byproducts mainly including downstream gases and ultraviolet light were used to treat the dye solution. The different influence of oxygen and air DBD plasmas on the degradation of methyl violet 5BN (MV-5BN), which is widely used in textile industry, was investigated in this paper. The results showed that the cooperation between ultraviolet light and active species generated by the DBD plasma can decolorize MV-5BN effectively, and the chromophore peaks attributed to the -NN- bonds in MV-5BN molecule disappeared entirely when the azo dye solutions were treated for 25 min by the air and oxygen DBD plasmas. The degradation reaction followed an exponential kinetics over time, and the peak of aromatic derivatives at 209 nm in UV-vis spectra increased nearly 2.7 times when the dye solution was treated for 30 min by air DBD plasma. However, the oxygen DBD plasma could deplete the aromatic derivatives entirely. It is found that the formation of O(3) and NO(x) in the downstream gases of air and oxygen plasmas may be responsible for the different effects on the azo dye degradation.

  3. Silent Discharge Plasma Technology for the Treatment of Air Toxics and Other Applications

    Energy Technology Data Exchange (ETDEWEB)

    Rosocha, Louis A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Chase, Peter J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Gross, Michael P. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    1998-09-21

    Under this CRADA, the Los Alamos National Laboratory (LANL) and High Mesa Technologies, Inc. (HMT) carried out a joint project on the development of the silent discharge plasma (SDP) technology for the treatment of hazardous air pollutants and other hazardous or toxic chemicals. The project had two major components: a technology-demonstration part and a scale-up and commercialization part. In the first part, a small-scale, mobile SDP plasma processor, which was being developed under a CRADA with the Electric Power Research Institute (EPRI) was the mobile equipment was modified for higher capacity service and employed for an innovative remediation technologies demonstration on soil-vapor extraction off-gases at the McClellan Air Force Base near Sacramento, CA. The performance of the SDP system for the variety of volatile organic compounds (VOCs) encountered at the McClellan site was sufficiently promising to the project HMT and LANL worked together to formulate a scale-up strategy and commercialization/manufacturing plan, and to design a prototype scaled-up SDP unit. HMT and LANL are now in the final stages of completing a licensing agreement for the technology and HMT is in the process of raising funds to engineer and manufacture commercial prototype SDP equipment focused on stack-gas emissions control and environmental remediation. HMT, in collaboration with another Northern New Mexico business, Coyote Aerospace, has also been successful in receiving a Phase I Small Business Innovative Research (SBIR) award from the Army Research Office to develop, design, and construct a small non-thermal plasma reactor for laboratory studies ("Non-Thermal Plasma Reactor for Control of Fugitive Emissions of Toxic Gases")

  4. Impurity intrusion in radio-frequency micro-plasma jets operated in ambient air

    CERN Document Server

    Niermann, B; Böke, M; Winter, J

    2011-01-01

    Space and time resolved concentrations of helium metastable atoms in an atmospheric pressure radio-frequency micro-plasma jet were measured using tunable diode laser absorption spectroscopy. Spatial profiles as well as lifetime measurements show significant influences of air entering the discharge from the front nozzle and of impurities originating from the gas supply system. Quenching of metastables was used to deduce quantitative concentrations of intruding impurities. The impurity profile along the jet axis was determined from optical emission spectroscopy as well as their dependance on the feed gas flow through the jet.

  5. Efficient new process for the desulfurization of mixtures of air and hydrogen sulfide via a dielectric barrier discharge plasma

    Directory of Open Access Journals (Sweden)

    S. Dahle

    2015-10-01

    Full Text Available The efficient removal of hydrogen sulfide, H2S, from streams of H2S in air via a dielectric barrier discharge (DBD plasma has been investigated using a quadrupole mass spectrometer. A suitable plasma device with a reservoir for storing sorbent powder of various kinds within the plasma region was constructed. Plasma treatments of gas streams with high concentrations of hydrogen sulfide in air yielded a removal of more than 98% of the initial hydrogen sulfide and a deposition of sulfur at the surface of the dielectric, while small amounts of sulfur dioxide were generated. The presence of calcium carbonate within the plasma region of the DBD device resulted in the removal of over 99% of the initial hydrogen sulfide content and the removal of 98% of the initial sulfur dioxide impurities from the gas mixture.

  6. Effect of high-power laser divergence on the plasma structural parameters during multiple filamentation in air

    Science.gov (United States)

    Geints, Yu. E.; Zemlyanov, A. A.

    2016-06-01

    Multiple filamentation of an infrared high-power laser pulse in air is considered. Based on the numerical solution to the unidirectional pulse propagation equation, the effect of radiation external focusing on the spatial structure of the plasma area produced in the filamentation region is studied. We show that the number of generated plasma channels in the beam wake and the density of their spatial distribution over the filamentation region depend on the initial divergence of laser radiation. We found that in a specific range of beam focusing the number of produced plasma channels could be minimized due to the formation of a consolidated thick plasma bunch at the beam axis.

  7. Atmospheric pressure He-air plasma jet: Breakdown process and propagation phenomenon

    Energy Technology Data Exchange (ETDEWEB)

    Begum, Asma [Independent University, Bangladesh, School of Engineering and Computer Science, Bashundhara, Dhaka (Bangladesh); Laroussi, Mounir [Old Dominion University, Department of Electrical and Computer Engineering, Norfolk, Virginia (United States); Pervez, Mohammad Rasel [Master Mind College, Department of Physics, Dhanmondi, Dhaka (Bangladesh)

    2013-06-15

    In this paper He-discharge (plasma jet/bullet) in atmospheric pressure air and its progression phenomenon has been studied experimentally using ICCD camera, optical emission spectroscopy (OES) and calibrated dielectric probe measurements. The repetitive nanosecond pulse has applied to a plasma pencil to generate discharge in the helium gas channel. The discharge propagation speed was measured from the ICCD images. The axial electric field distribution in the plasma jet is inferred from the optical emission spectroscopic data and from the probe measurement. The correlation between the jet velocities, jet length with the pulse duration is established. It shows that the plasma jet is not isolated from the input voltage along its propagation path. The discharge propagation speed, the electron density and the local and average electric field distribution along the plasma jet axis predicted from the experimental results are in good agreement with the data predicted by numerical simulation of the streamer propagation presented in different literatures. The ionization phenomenon of the discharge predicts the key ionization parameters, such as speed, peak electric field in the front, and electron density. The maximum local electric field measured by OES is 95 kV/cm at 1.3 cm of the jet axis, and average EF measured by probe is 24 kV/cm at the same place of the jet. The average and local electron density estimated are in the order of 10{sup 11} cm{sup -3} and it reaches to the maximum of 10{sup 12} cm{sup -3}.

  8. Influence of air diffusion on the OH radicals and atomic O distribution in an atmospheric Ar (bio)plasma jet

    Science.gov (United States)

    Nikiforov, A.; Li, L.; Britun, N.; Snyders, R.; Vanraes, P.; Leys, C.

    2014-02-01

    Treatment of samples with plasmas in biomedical applications often occurs in ambient air. Admixing air into the discharge region may severely affect the formation and destruction of the generated oxidative species. Little is known about the effects of air diffusion on the spatial distribution of OH radicals and O atoms in the afterglow of atmospheric-pressure plasma jets. In our work, these effects are investigated by performing and comparing measurements in ambient air with measurements in a controlled argon atmosphere without the admixture of air, for an argon plasma jet. The spatial distribution of OH is detected by means of laser-induced fluorescence diagnostics (LIF), whereas two-photon laser-induced fluorescence (TALIF) is used for the detection of atomic O. The spatially resolved OH LIF and O TALIF show that, due to the air admixture effects, the reactive species are only concentrated in the vicinity of the central streamline of the afterglow of the jet, with a characteristic discharge diameter of ˜1.5 mm. It is shown that air diffusion has a key role in the recombination loss mechanisms of OH radicals and atomic O especially in the far afterglow region, starting up to ˜4 mm from the nozzle outlet at a low water/oxygen concentration. Furthermore, air diffusion enhances OH and O production in the core of the plasma. The higher density of active species in the discharge in ambient air is likely due to a higher electron density and a more effective electron impact dissociation of H2O and O2 caused by the increasing electrical field, when the discharge is operated in ambient air.

  9. Air plasma assisting microcontact deprinting and printing for gold thin film and PDMS patterns.

    Science.gov (United States)

    Gou, Hong-Lei; Xu, Jing-Juan; Xia, Xing-Hua; Chen, Hong-Yuan

    2010-05-01

    In this paper, we present a simple method to fabricate gold film patterns and PDMS patterns by air plasma assisting microcontact deprinting and printing transfer approaches. Chemical gold plating is employed instead of conventional metal evaporation or sputtering to obtain perfect gold film both on flat and topographic PDMS chips, and complicated SAM precoating is replaced by simple air plasma treatment to activate both the surface of gold film and PDMS. In this way, large area patterns of conductive gold film and PDMS patterns could be easily obtained on the elastomeric PDMS substrate. Both the chemical plating gold film and transferred gold film were of good electrochemical properties and similar hydrophilicity with smooth and conductive surface, which made it potentially useful in microfluidic devices and electronics. The gold transfer mechanism is discussed in detail. For typical applications, a cell patterning chip based on the gold pattern was developed to imply the interfacial property, and dielectrophoresis control of live cells was carried out with the patterned gold as interdigital electrodes to show the conductivity.

  10. Indentations on Air Plasma Sprayed Thermal Barrier Coatings Prepared by Different Starting Granules

    Directory of Open Access Journals (Sweden)

    Yong Suk Heo

    2015-01-01

    Full Text Available The effect of starting granules on the indentation properties of air plasma sprayed thermal barrier coatings (TBCs is investigated in this paper. Various kinds of spray-dried granules are prepared from different processing conditions, especially varying solvent and dispersant, showing a deformed hollow-typed and a filled spherical-typed granule. The similar coating thicknesses are prepared by adjusting process parameters during air plasma spray. All XRD peaks in phase analysis are tetragonal and cubic phases without any monoclinic phase after the starting granules were heat-treated. A relatively porous microstructure of the coating layer could be obtained from the monodisperse granules, while a relatively dense microstructure resulted from the hollow-typed granules. The morphology and distribution of the granules crucially affect the microstructure of thermal barrier coatings and thus have influences on indentation properties such as indentation stress-strain curves, contact damage, and hardness. The implication concerning microstructure design of TBCs for gas turbine applications is considered.

  11. Effects of atmospheric air plasma treatment of graphite and carbon felt electrodes on the anodic current from Shewanella attached cells.

    Science.gov (United States)

    Epifanio, Monica; Inguva, Saikumar; Kitching, Michael; Mosnier, Jean-Paul; Marsili, Enrico

    2015-12-01

    The attachment of electrochemically active microorganisms (EAM) on an electrode is determined by both the chemistry and topography of the electrode surface. Pre-treatment of the electrode surface by atmospheric air plasma introduces hydrophilic functional groups, thereby increasing cell attachment and electroactivity in short-term experiments. In this study, we use graphite and carbon felt electrodes to grow the model EAM Shewanella loihica PV-4 at oxidative potential (0.2 V vs. Ag/AgCl). Cell attachment and electroactivity are measured through electrodynamic methods. Atmospheric air plasma pre-treatment increases cell attachment and current output at graphite electrodes by 25%, while it improves the electroactivity of the carbon felt electrodes by 450%. Air plasma pre-treatment decreased the coulombic efficiency on both carbon felt and graphite electrodes by 60% and 80%, respectively. Microbially produced flavins adsorb preferentially at the graphite electrode, and air plasma pre-treatment results in lower flavin adsorption at both graphite and carbon felt electrodes. Results show that air plasma pre-treatment is a feasible option to increase current output in bioelectrochemical systems.

  12. Effects of non-thermal plasmas and electric field on hydrocarbon/air flames

    Science.gov (United States)

    Ganguly, Biswa

    2009-10-01

    Need to improve fuel efficiency, and reduce emission from hydrocarbon combustor in automotive and gas turbine engines have reinvigorated interest in reducing combustion instability of a lean flame. The heat generation rate in a binary reaction is HQ =N^2 c1c2 Q exp(-E/RT), where N is the density, c1 and c2 are mol fractions of the reactants, Q is the reaction heat release, E is the activation energy, R is the gas constant and T is the average temperature. For hydrocarbon-air reactions, the typical value of E/R ˜20, so most heat release reactions are confined to a thin reaction sheet at T >=1400 K. The lean flame burning condition is susceptible to combustion instability due to a critical balance between heat generation and heat loss rates, especially at high gas flow rate. Radical injection can increase flame speed by reducing the hydrocarbon oxidation reaction activation barrier and it can improve flame stability. Advances in nonequilibrium plasma generation at high pressure have prompted its application for energy efficient radical production to enhance hydrocarbon-air combustion. Dielectric barrier discharges and short pulse excited corona discharges have been used to enhance combustion stability. Direct electron impact dissociation of hydrocarbon and O2 produces radicals with lower fuel oxidation reaction activation barriers, initiating heat release reaction CnHm+O CnHm-1+ OH (and other similar sets of reactions with partially dissociated fuel) below the typical cross-over temperature. Also, N2 (A) produced in air discharge at a moderate E/n can dissociate O2 leading to oxidation of fuel at lower gas temperature. Low activation energy reactions are also possible by dissociation of hydrocarbon CnHm+e -> CnHm-2+H2+e, where a chain propagation reaction H2+ O OH+H can be initiated at lower gas temperature than possible under thermal equilibrium kinetics. Most of heat release comes from the reaction CO+OH-> CO2 +H, nonthermal OH production seem to improve

  13. Effects of air transient spark discharge and helium plasma jet on water, bacteria, cells, and biomolecules.

    Science.gov (United States)

    Hensel, Karol; Kučerová, Katarína; Tarabová, Barbora; Janda, Mário; Machala, Zdenko; Sano, Kaori; Mihai, Cosmin Teodor; Ciorpac, Mitică; Gorgan, Lucian Dragos; Jijie, Roxana; Pohoata, Valentin; Topala, Ionut

    2015-06-06

    Atmospheric pressure DC-driven self-pulsing transient spark (TS) discharge operated in air and pulse-driven dielectric barrier discharge plasma jet (PJ) operated in helium in contact with water solutions were used for inducing chemical effects in water solutions, and the treatment of bacteria (Escherichia coli), mammalian cells (Vero line normal cells, HeLa line cancerous cells), deoxyribonucleic acid (dsDNA), and protein (bovine serum albumin). Two different methods of water solution supply were used in the TS: water electrode system and water spray system. The effects of both TS systems and the PJ were compared, as well as a direct exposure of the solution to the discharge with an indirect exposure to the discharge activated gas flow. The chemical analysis of water solutions was performed by using colorimetric methods of UV-VIS absorption spectrophotometry. The bactericidal effects of the discharges on bacteria were evaluated by standard microbiological plate count method. Viability, apoptosis and cell cycle were assessed in normal and cancerous cells. Viability of cells was evaluated by trypan blue exclusion test, apoptosis by Annexin V-FITC/propidium iodide assay, and cell cycle progression by propidium iodide/RNase test. The effect of the discharges on deoxyribonucleic acid and protein were evaluated by fluorescence and UV absorption spectroscopy. The results of bacterial and mammalian cell viability, apoptosis, and cell cycle clearly show that cold plasma can inactivate bacteria and selectively target cancerous cells, which is very important for possible future development of new plasma therapeutic strategies in biomedicine. The authors found that all investigated bio-effects were stronger with the air TS discharge than with the He PJ, even in indirect exposure.

  14. Effects of humidity on the plasma-catalytic removal of low-concentration BTX in air.

    Science.gov (United States)

    Fan, Xing; Zhu, Tianle; Wan, Yajuan; Yan, Xiao

    2010-08-15

    Effects of relative humidity (30%, 50% and 80% RH) on the removal of low-concentration benzene, toluene and p-xylene (BTX mixture) in air by non-thermal plasma (NTP) and the combination of NTP and MnO(x)/Al(2)O(3) catalyst (CPC) were systematically investigated in a link tooth wheel-cylinder plasma reactor. A long-term (150 h) CPC experiment under 30% RH was also conducted to investigate the stability of the catalyst. Results show that increasing humidity inhibits the O(3) production in plasma and its decomposition over the catalyst. As for BTX conversion, increasing humidity suppresses the benzene conversion by both NTP and CPC; although higher humidity slightly promotes the toluene conversion by NTP, it negatively influences that by CPC; while the conversion of p-xylene by both NTP and CPC is insensitive to the humidity levels. Irrespective of the RH, the introduction of MnO(x)/Al(2)O(3) catalyst significantly promotes BTX conversion and improves the energy efficiency. On the other hand, CPC under 30% RH shows the best performance towards CO(x) formation during BTX oxidation processes. However, for a specific input energy of 10 J L(-1) in this study, organic intermediates generated and accumulated over the catalyst surface, resulting in a slight deactivation of the MnO(x)/Al(2)O(3) catalyst after 150-h reactions. Copyright 2010 Elsevier B.V. All rights reserved.

  15. Controlled cytotoxicity of plasma treated water formulated by open-air hybrid mode discharge

    Science.gov (United States)

    Lu, P.; Boehm, D.; Cullen, P.; Bourke, P.

    2017-06-01

    Plasma treated liquids (PTLs) provide a means to convey a broad range of effects of relevance for food, environmental, or clinical decontamination, plant growth promotion, and therapeutic applications. Devising the reactive species ingredients and controlling the biological response of PTLs are of great interest. We demonstrate an approach by using an open-air hybrid mode discharge (HMD) to control the principal reactive species composition within plasma treated water (PTW), which is then demonstrated to regulate the cytotoxicity of PTW. The cytotoxicity of HMD produced PTW demonstrates a non-monotonic change over the discharge time. Although hydrogen peroxide and nitrite are not the sole effectors for cell death caused by PTW, using them as principal reactive species indicators, cytotoxicity can be removed and/or enhanced by formulating their concentrations and composition through adjusting the discharge mode and time on-line during PTW generation without the addition of additional working gas or chemical scavengers. This work demonstrates that a hybrid mode discharge can be employed to generate a PTW formulation to control a biological response such as cytotoxicity. This provides insights into how plasma treated liquids may be harnessed for biological applications in a specific and controllable manner.

  16. The Mutation Breeding and Mutagenic Effect of Air Plasma on Penicillium Chrysogenum

    Institute of Scientific and Technical Information of China (English)

    桂芳; 王辉; 王鹏; 刘会; 蔡晓春; 胡以华; 袁成凌; 郑之明

    2012-01-01

    Low temperature air plasma was used as the mutation tool for penicillin-producing strain Penicillium chrysogenum. The discharge conditions were RF power of 360 W, temperature of 40℃ in a sealed chamber, and pressure of 10 Pa to 30 Pa. The result showed that the kinetics of the survival rate followed a typical saddle-shaped curve. Based on a statistic analysis, at the treating duration of 10 min, the positive mutation rate was as high as 37.5% while the negative mutation rate was low. The colonial morphology changed obviously when the plasma treating duration reached or exceeded 45 min. After both primary and secondary screening, a mutant designated as aPc051310 with high productivity of penicillin was obtained, and a strong mutagenic effect on P. chrysogenurn was observed in the process. It was proved that after five generations, the mutant aPc051310 still exhibits a high productivity. All the results prove that the plasma mutation method could be developed as a convenient and effective tool to breed high-yield strains in the fermentation industry, while expanding the plasm application at the same time.

  17. Modeling plasma glow discharges in Air near a Mach 3 bow shock with KRONOS

    Science.gov (United States)

    Rassou, Sebastien; Labaune, Julien; Packan, Denis; Elias, Paul-Quentin

    2016-09-01

    In this work, plasma glow discharge in Air is modeled near a Mach 3 bow shock. Numerical simulations are performed using the coupling KRONOS which have been developed at ONERA. The flow field is modeled using the code CFD: CEDRE from ONERA and the electrical and plasma part by the EDF open-source code CODE_SATURNE. The plasma kinetic modeling consists on a two-term Boltzmann equation solver and a chemical reaction solver depending of the electric field. The coupling KRONOS is fully parallelized and run on ONERA supercomputers. The shock wave is formed by the propagation of a supersonic flow (M = 3) through a truncated conical model mounted with a central spike. Depending on the spike's voltage value, corona, glow or arc regime could be obtained in a steady flow. The parameters for the supersonic flow and the spike configurations are chosen to be in glow discharge regime and to reproduce the experimental setup. In our simulations, 12 species and 80 reactions (ionization, electronic or vibrational excitation, attachment etc ...) are considered to properly model the glow discharge and the afterglow. In a stationary flow, glow discharge is observed only at the upstream of the shock wave near the high voltage spike. Behind the bow shock, in the afterglow, negative ions are provided by electrons attachment with O2. The negative ions flow convection ensures the electrical conduction and the establishment of the glow discharge.

  18. Numerically optimized band boundaries of Planck mean absorption coefficients in air plasma

    Science.gov (United States)

    Kloc, P.; Aubrecht, V.; Bartlova, M.

    2017-08-01

    Radiation heat transfer plays an important role in the energy balance of plasma in an electric arc and its accurate prediction is essential for the development of new electrical devices. Unfortunately, a very complex spectrum of the absorption coefficient makes accurate radiation heat transfer calculations a very challenging task, especially with complex geometries. Numerical approximation of the absorption coefficient is therefore commonly used to reduce computing demands. This paper presents our contribution to the topic of computing requirements reduction, namely the problem of frequency band selection for mean absorption coefficients (MACs). We show that, with the proper band distribution and averaging method, even a very low number of bands can be sufficient for an accurate approximation of the real radiation heat transfer. The band selection process is based upon numerical optimization with a mean value of each band being calculated as a line limited Planck MAC. Both the line limiting factor and associated characteristic plasma absorption length are investigated in detail and an optimal value equal to the three plasma radii is proposed. Tables for three bands mean absorption coefficients in air at the pressure of 1 bar and temperature range spanning from 300 K to 30 kK are included in this paper. These tables serve as input parameters for a fast evaluation of radiation transfer using either the P1 or discrete ordinates method (DOM) approximation with satisfactory accuracy.

  19. Products and mechanisms of the oxidation of organic compounds in atmospheric air plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Marotta, Ester; Schiorlin, Milko; Paradisi, Cristina [Department of Chemical Sciences, Universita di Padova, Via Marzolo 1, 35131 Padova (Italy); Rea, Massimo, E-mail: cristina.paradisi@unipd.i [Department of Electrical Engineering, Universita di Padova, 35131 Padova (Italy)

    2010-03-31

    Atmospheric plasma-based technologies are developing as a powerful means for air purification, specifically for the oxidation of organic pollutants. To achieve a better control on the emissions produced by such treatments mechanistic insight is needed in the complex reactions of volatile organic compounds (VOCs) within the plasma. An account is given here of our comparative studies of the behaviour of model VOCs in response to different corona regimes (+dc, -dc and +pulsed) implemented within the same flow reactor. Model VOCs considered include two alkanes (n-hexane and i-octane), one aromatic hydrocarbon (toluene) and two halogenated methanes, dibromomethane (CH{sub 2}Br{sub 2}) and dibromodifluoromethane (CF{sub 2}Br{sub 2}, halon 1202). Efficiency and product data are reported and discussed as well as various possible initiation reactions. A powerful diagnostic tool is ion analysis, performed by atmospheric pressure chemical ionization-mass spectrometry: it provides a map of major ions and ion-molecule reactions and a rationale for interpreting current/voltage characteristics of dc coronas. It is shown that, depending on the specific VOC and corona regime adopted, different initiation steps prevail in the VOC-oxidation process and that the presence of a VOC, albeit in small amounts (500 ppm), can greatly affect some important plasma properties (ion population, current/voltage profile, post-discharge products).

  20. Etching of polymers, proteins and bacterial spores by atmospheric pressure DBD plasma in air

    Science.gov (United States)

    Kuzminova, A.; Kretková, T.; Kylián, O.; Hanuš, J.; Khalakhan, I.; Prukner, V.; Doležalová, E.; Šimek, M.; Biederman, H.

    2017-04-01

    Many studies proved that non-equilibrium discharges generated at atmospheric pressure are highly effective for the bio-decontamination of surfaces of various materials. One of the key processes that leads to a desired result is plasma etching and thus the evaluation of etching rates of organic materials is of high importance. However, the comparison of reported results is rather difficult if impossible as different authors use diverse sources of atmospheric plasma that are operated at significantly different operational parameters. Therefore, we report here on the systematic study of the etching of nine different common polymers that mimic the different structures of more complicated biological systems, bovine serum albumin (BSA) selected as the model protein and spores of Bacillus subtilis taken as a representative of highly resistant micro-organisms. The treatment of these materials was performed by means of atmospheric pressure dielectric barrier discharge (DBD) sustained in open air at constant conditions. All tested polymers, BSA and spores, were readily etched by DBD plasma. However, the measured etching rates were found to be dependent on the chemical structure of treated materials, namely on the presence of oxygen in the structure of polymers.

  1. The Mutation Breeding and Mutagenic Effect of Air Plasma on Penicillium Chrysogenum

    Science.gov (United States)

    Gui, Fang; Wang, Hui; Wang, Peng; Liu, Hui; Cai, Xiaochun; Hu, Yihua; Yuan, Chengling; Zheng, Zhiming

    2012-04-01

    Low temperature air plasma was used as the mutation tool for penicillin-producing strain Penicillium chrysogenum. The discharge conditions were RF power of 360 W, temperature of 40°C in a sealed chamber, and pressure of 10 Pa to 30 Pa. The result showed that the kinetics of the survival rate followed a typical saddle-shaped curve. Based on a statistic analysis, at the treating duration of 10 min, the positive mutation rate was as high as 37.5% while the negative mutation rate was low. The colonial morphology changed obviously when the plasma treating duration reached or exceeded 45 min. After both primary and secondary screening, a mutant designated as aPc051310 with high productivity of penicillin was obtained, and a strong mutagenic effect on P. chrysogenum was observed in the process. It was proved that after five generations, the mutant aPc051310 still exhibits a high productivity. All the results prove that the plasma mutation method could be developed as a convenient and effective tool to breed high-yield strains in the fermentation industry, while expanding the plasm application at the same time.

  2. Vitrified chiral-nematic liquid crystalline films for selective reflection and circular polarization

    Energy Technology Data Exchange (ETDEWEB)

    Katsis, D.; Chen, P.H.M.; Mastrangelo, J.C.; Chen, S.H. [Univ. of Rochester, NY (United States); Blanton, T.N. [Eastman Kodak Co., Rochester, NY (United States)

    1999-06-01

    Nematic and left-handed chiral-nematic liquid crystals comprising methoxybiphenylbenzoate and (S)-(-)-1-phenylethylamine pendants to a cyclohexane core were synthesized and characterized. Although pristine samples were found to be polycrystalline, thermal quenching following heating to and annealing at elevated temperatures permitted the molecular orders characteristic of liquid crystalline mesomorphism to be frozen in the glassy state. Left at room temperature for 6 months, the vitrified liquid crystalline films showed no evidence of recrystallization. An orientational order parameter of 0.65 was determined with linear dichroism of a vitrified nematic film doped with Exalite 428 at a mole fraction of 0.0025. Birefringence dispersion of a blank vitrified nematic film was determined using a phase-difference method complemented by Abbe refractometry. A series of vitrified chiral-nematic films were prepared to demonstrate selective reflection and circular polarization with a spectral region tunable from blue to the infrared region by varying the chemical composition. The experimentally measured circular polarization spectra were found to agree with the Good-Karali theory in which all four system parameters were determined a priori: optical birefringence, average refractive index, selective reflection wavelength, and film thickness.

  3. In-straw cryoprotectant dilution of IVP bovine blastocysts vitrified in hand-pulled glass micropipettes.

    Science.gov (United States)

    Vieira, A D; Forell, F; Feltrin, C; Rodrigues, J L

    2007-06-01

    The aim of this study was to determine the influence of two ethylene glycol-based vitrification solutions on in vitro and in vivo survival after in-straw cryoprotectant dilution of vitrified in vitro-produced bovine embryos. Day-7 expanded blastocysts were selected according to diameter (> or = 180 microm) and osmotic characteristics and randomly assigned to one of three groups (i) VSa: vitrification in 40% EG+17.1% SUC+0.1% PVA; (ii) VSb: vitrification in 20% EG+20% DMSO; (iii) control: non-vitrified embryos. Vitrification was performed in hand-pulled glass micropipettes (GMP) and cryoprotectant dilution in 0.25 ml straws after warming in a plastic tube. Embryo viability was assessed by re-expansion and hatching rates after 72 h of IVC and by pregnancy rates after direct transfer of vitrified embryos. No differences in re-expansion rates were observed between vitrified groups after 24 h in culture (VSa=84.5%; VSb=94.8%). However, fewer VSa embryos (55.2%, Pstraw cryoprotectant dilution and direct embryo transfer.

  4. Pregnancy rates following timed embryo transfer with fresh or vitrified in vitro produced embryos in lactating dairy cows under heat stress conditions.

    Science.gov (United States)

    Al-Katanani, Y M; Drost, M; Monson, R L; Rutledge, J J; Krininger, C E; Block, J; Thatcher, W W; Hanse, P J

    2002-07-01

    Timed embryo transfer (TET) using in vitro produced (IVP) embryos without estrus detection can be used to reduce adverse effects of heat stress on fertility. One limitation is the poor survival of IVP embryos after cryopreservation. Objectives of this study were to confirm beneficial effects of TET on pregnancy rate during heat stress as compared to timed artificial insemination (TAI), and to determine if cryopreservation by vitrification could improve survival of IVP embryos transferred to dairy cattle under heat stress conditions. For vitrified embryos (TET-V), a three-step pre-equilibration procedure was used to vitrify excellent and good quality Day 7 IVP Holstein blastocysts. For fresh IVP embryos (TET-F), Holstein oocytes were matured and fertilized; resultant embryos were cultured in modified KSOM for 7 days using the same method as for production of vitrified embryos. Excellent and good quality blastocysts on Day 7 were transported to the cooperating dairy in a portable incubator. Nonpregnant, lactating Holsteins (n = 155) were treated with GnRH (100 microg, i.m., Day 0), followed 7 days later by prostaglandin F2alpha (PGF2alpha, 25 mg, i.m.) and GnRH (100 microg) on Day 9. Cows in the TAI treatment (n = 68) were inseminated the next day (Day 10) with semen from a single bull that also was used to produce embryos. Cows in the other treatments (n = 33 for TET-F; n = 54 for TET-V) received an embryo on Day 17 (i.e. Day 7 after anticipated ovulation and Day 8 after second GnRH treatment). The proportion of cows that responded to synchronization based on plasma progesterone concentrations on Day 10 and Day 17 was 67.7%. Pregnancy rate for all cows on Day 45 was higher (P cows responding to synchronization, pregnancy rate was also higher (P cows producing more milk had lower (P cows producing less milk. In conclusion, ET of fresh IVP embryos can improve pregnancy rate under heat stress conditions, but pregnancy rate following transfer of vitrified embryos was no

  5. Multi-Group Reductions of LTE Air Plasma Radiative Transfer in Cylindrical Geometries

    Science.gov (United States)

    Scoggins, James; Magin, Thierry Edouard Bertran; Wray, Alan; Mansour, Nagi N.

    2013-01-01

    Air plasma radiation in Local Thermodynamic Equilibrium (LTE) within cylindrical geometries is studied with an application towards modeling the radiative transfer inside arc-constrictors, a central component of constricted-arc arc jets. A detailed database of spectral absorption coefficients for LTE air is formulated using the NEQAIR code developed at NASA Ames Research Center. The database stores calculated absorption coefficients for 1,051,755 wavelengths between 0.04 µm and 200 µm over a wide temperature (500K to 15 000K) and pressure (0.1 atm to 10.0 atm) range. The multi-group method for spectral reduction is studied by generating a range of reductions including pure binning and banding reductions from the detailed absorption coefficient database. The accuracy of each reduction is compared to line-by-line calculations for cylindrical temperature profiles resembling typical profiles found in arc-constrictors. It is found that a reduction of only 1000 groups is sufficient to accurately model the LTE air radiation over a large temperature and pressure range. In addition to the reduction comparison, the cylindrical-slab formulation is compared with the finite-volume method for the numerical integration of the radiative flux inside cylinders with varying length. It is determined that cylindrical-slabs can be used to accurately model most arc-constrictors due to their high length to radius ratios.

  6. Predictive value of serum HCG concentrations in pregnancies achieved after single fresh or vitrified-warmed blastocyst transfer.

    Science.gov (United States)

    Oron, Galia; Shavit, Tal; Esh-Broder, Efrat; Weon-Young, Son; Tulandi, Togas; Holzer, Hananel

    2017-09-01

    Possible differences between serum HCG levels in pregnancies achieved after transfer of a single fresh or a vitrified-warmed blastocyst were evaluated. Out of 1130 single blastocyst transfers resulting in positive HCG results, 789 were single fresh blastocyst transfers and 341 single vitrified-warmed blastocyst transfers. The initial serum HCG levels of 869 clinical intrauterine pregnancies were evaluated, 638 after the transfer of a single fresh blastocysts and 231 after the transfer of a single vitrified-warmed blastocysts. The HCG levels from cycles resulting in a clinical intrauterine pregnancy were significantly higher after the transfer of a single vitrified-warmed blastocyst (383 ± 230 IU/l) versus a fresh transfer (334 ± 192 IU/l; P = 0.01). Threshold values for predicting a clinical pregnancy for a fresh blastocyst were 111 IU/l and for a vitrified-warmed blastocyst 137 IU/l. Our study shows that the overall beta-HCG levels are comparable after the transfer of a fresh or vitrified-warmed blastocyst, suggesting that vitrification most probably does not affect the ability of the embryos to produce beta-HCG. This study further shows that when clinicians counsel patients, they should take into account that higher HCG levels are needed after a vitrified-warmed blastocyst transfer to predict a clinical intrauterine pregnancy. Copyright © 2017 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.

  7. Transient heating of metals by Microsecond-duration CO/sub 2/ laser pulses with air plasma ignition

    Energy Technology Data Exchange (ETDEWEB)

    McKay, J.A.; Schriempf, J.T.

    1979-04-15

    We present a theoretical model for the heating of metal targets by CO/sub 2/ laser pulses, with air plasma ignition. Such modeling is necessary for deduction of the details of the thermal transient at the target surface, direct measurement of the transient being difficult or impossible, and the thermal flux being determined by the plasma coupling efficiency rather than the laser flux. Our model permits calculation of the thermal transient from simple time-integrated thermal fluence and energy deposition data.

  8. Cold atmospheric-pressure air plasma treatment of C6 glioma cells: effects of reactive oxygen species in the medium produced by the plasma on cell death

    Science.gov (United States)

    Wang, Yuyang; Cheng, Cheng; Gao, Peng; Li, Shaopeng; Shen, Jie; Lan, Yan; Yu, Yongqiang; Chu, Paul K.

    2017-02-01

    An atmospheric-pressure air plasma is employed to treat C6 glioma cells in vitro. To elucidate on the mechanism causing cell death and role of reactive species (RS) in the medium produced by the plasma, the concentration of the long-lived RS such as hydrogen peroxide, nitrate, and ozone in the plasma-treated liquid (phosphate-buffered saline solution) is measured. When vitamin C is added to the medium as a ROS quencher, the viability of C6 glioma cells after the plasma treatment is different from that without vitamin C. The results demonstrate that reactive oxygen species (ROS) such as H2O2, and O3 constitute the main factors for inactivation of C6 glioma cells and the reactive nitrogen species (RNS) may only play an auxiliary role in cell death.

  9. Cold atmospheric-pressure air plasma treatment of C6 glioma cells: effects of reactive oxygen species in the medium produced by the plasma on cell death

    Science.gov (United States)

    Yuyang, Wang; Cheng, Cheng; Peng, Gao; Shaopeng, Li; Jie, Shen; Yan, Lan; Yongqiang, Yu; Paul, K. Chu

    2017-02-01

    An atmospheric-pressure air plasma is employed to treat C6 glioma cells in vitro. To elucidate on the mechanism causing cell death and role of reactive species (RS) in the medium produced by the plasma, the concentration of the long-lived RS such as hydrogen peroxide, nitrate, and ozone in the plasma-treated liquid (phosphate-buffered saline solution) is measured. When vitamin C is added to the medium as a ROS quencher, the viability of C6 glioma cells after the plasma treatment is different from that without vitamin C. The results demonstrate that reactive oxygen species (ROS) such as H2O2, and O3 constitute the main factors for inactivation of C6 glioma cells and the reactive nitrogen species (RNS) may only play an auxiliary role in cell death.

  10. Cell immobilization on polymer by air atmospheric pressure plasma jet treatment

    Science.gov (United States)

    Lee, Jung-Hwan; Kwon, Jae-Sung; Om, Ji-yeon; Kim, Yong-Hee; Choi, Eun-Ha; Kim, Kwang-Mahn; Kim, Kyoung-Nam

    2014-08-01

    The study of cell immobilization on delicate polymer by an air atmospheric pressure plasma jet (AAPPJ) is required for its medical application. The aim of this study was to evaluate whether AAPPJ treatment induce cell immobilization effect on delicate polymers without significant change of surface roughness by AAPPJ treatment. After surface roughness, dynamic contact angle, and chemical characteristics were investigated, the immobilization effect was evaluated with the mouse fibroblast L929 cell line. Surface roughness change was not observed (P > 0.05) in either delicate dental wax or polystyrene plate (PSP) as advancing and receding contact angles significantly decreased (P < 0.05), thanks to decreased hydrocarbon and formation of oxygen-related functional groups in treated PSP. Adherent L929 cells with elongated morphology were found in treated PSP along with the formation of immobilization markers vinculin and actin cytoskeleton. Increased PTK2 gene expression upregulated these markers on treated PSP.

  11. Force Measurements of Single and Double Barrier DBD Plasma Actuators in Quiescent Air

    Science.gov (United States)

    Hoskinson, Alan R.; Hershkowitz, Noah; Ashpis, David E.

    2008-01-01

    We have performed measurements of the force induced by both single (one electrode insulated) and double (both electrodes insulated) dielectric barrier discharge plasma actuators in quiescent air. We have shown that, for single barrier actuators, as the electrode diameter decreased below those values previously studied the induced Force increases exponentially rather than linearly. This behavior has been experimentally verified using two different measurement techniques: stagnation probe measurements of the induced flow velocity and direct measurement of the force using an electronic balance. In addition, we have shown the the induced force is independent of the material used for the exposed electrode. The same techniques have shown that the induced force of a double barrier actuator increases with decreasing narrow electrode diameter.

  12. Comparisons of Force Measurement Methods for DBD Plasma Actuators in Quiescent Air

    Science.gov (United States)

    Hoskinson, Alan R.; Hershkowitz, Noah; Ashpis, David E.

    2009-01-01

    We have performed measurements of the force induced by both single (one electrode insulated) and double (both electrodes insulated) dielectric barrier discharge plasma actuators in quiescent air. We have shown that, for single barrier actuators with cylindrical exposed electrodes, as the electrode diameter decrease the force efficiencies increase much faster than a previously reported linear trend. This behavior has been experimentally verified using two different measurement techniques: stagnation probe measurements of the induced flow velocity and direct measurement of the force using an electronic balance. Actuators with rectangular cross-section exposed electrodes do not show the same rapid increase at small thicknesses. We have also shown that the induced force is independent of the material used for the exposed electrode. The same techniques have shown that the induced force of a double barrier actuator increases with decreasing narrow electrode diameter.

  13. Technology and complete set of the equipment of air-plasma method for synthesis of nanoaerosols

    Science.gov (United States)

    Kopytin, Yurii D.; Novikov, O. G.

    2004-02-01

    The paper is aimed at studying synthesis and construction, as well as physical-chemical characteristics of nanoaerosols. The technology and product line of the Air-plasma method for synthesis of metal oxide nanopowders to obtain high-performance ceramics (PSNP) is hot and set at manufacturing different-types zirconium ceramics stabilized by yttrium and magnesium oxides, as well as other dopes. For the available equipment, the technologies of producing nanopowders of other metal oxides alongside with circonium oxide and composite oxides (Al203, Ti02, CuO, SiO2, Fe2O2, ZnO, CoO, Cr2O3, PbO, MnO, MgO, CaO, CeO, etc.) are developed and adapted.

  14. Electrical conductivity of a methane-air burning plasma under the action of weak electric fields

    Science.gov (United States)

    Colonna, G.; Pietanza, L. D.; D'Angola, A.; Laricchiuta, A.; Di Vita, A.

    2017-02-01

    This paper focuses on the calculation of the electrical conductivity of a methane-air flame in the presence of weak electric fields, solving the Boltzmann equation for free electrons self-consistently coupled with chemical kinetics. The chemical model GRI-Mech 3.0 has been completed with chemi-ionization reactions to model ionization in the absence of fields, and a database of cross sections for electron-impact-induced processes to account for reactions and transitions activated in the flame during discharge. The dependence of plasma properties on the frequency of an oscillating field has been studied under different pressure and gas temperature conditions. Fitting expressions of the electrical conductivity as a function of gas temperature and methane consumption are provided for different operational conditions in the Ansaldo Energia burner.

  15. Preparation and characterization of molybdenum disilicide coating on molybdenum substrate by air plasma spraying

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yi [Key Laboratory of Ministry of Education for Non-ferrous Materials Science and Engineering, Central South University, Changsha 410083 (China); Key Laboratory of Hunan Province for Metallurgy and Material Processing of Rare Metals, Central South University, Changsha 410083 (China); School of Materials Science and Engineering, Central South University, Changsha 410083 (China); Wang, Dezhi, E-mail: dzwang68@163.com [Key Laboratory of Ministry of Education for Non-ferrous Materials Science and Engineering, Central South University, Changsha 410083 (China); Key Laboratory of Hunan Province for Metallurgy and Material Processing of Rare Metals, Central South University, Changsha 410083 (China); School of Materials Science and Engineering, Central South University, Changsha 410083 (China); Yan, Jianhui [Advanced Materials Synthesis and Application Technology Laboratory, Hunan University of Science and Technology, Xiangtan 411201 (China); Sun, Aokui [Key Laboratory of Ministry of Education for Non-ferrous Materials Science and Engineering, Central South University, Changsha 410083 (China); Key Laboratory of Hunan Province for Metallurgy and Material Processing of Rare Metals, Central South University, Changsha 410083 (China); School of Materials Science and Engineering, Central South University, Changsha 410083 (China)

    2013-11-01

    MoSi{sub 2} oxidation protective coatings on molybdenum substrate were prepared by air plasma spraying technique (APS). Microstructure, phase composition, porosity, microhardness and bonding strength of the coatings were investigated and determined. Oxidation behavior of the coating at high temperature was also examined. Results show that composition of the coatings is constituted with MoSi{sub 2} and Mo{sub 5}Si{sub 3}, the surface morphology is described as flattened lamellar features, insufficiently flattened protuberance with some degree of surface roughness, a certain quantity of spherical particles, microcracks and pores. Testing results reveal that microhardness and bonding strength of the coatings increase, and porosity decreases with increasing power or decreasing Ar gas flow rate. Moreover, with decreasing the porosity, the microhardness of the coatings increases. The bonding strength of the coatings also increases with increasing spray distance. The MoSi{sub 2} coated Mo substrate exhibited a good oxidation resistance at 1200 °C.

  16. Microwave air plasmas in capillaries at low pressure II. Experimental investigation

    Science.gov (United States)

    Stancu, G. D.; Leroy, O.; Coche, P.; Gadonna, K.; Guerra, V.; Minea, T.; Alves, L. L.

    2016-11-01

    This work presents an experimental study of microwave (2.45 GHz excitation frequency) micro-plasmas, generated in dry air (N2 80%: O2 20%) within a small radius silica capillary (345 µm inner radius) at low pressure (300 Pa) and low powers (80-130 W). Experimental diagnostics are performed using optical emission spectroscopy calibrated in absolute intensity. Axial-resolved measurements (50 µm spatial resolution) of atomic transitions N(3p4S)  →  N(3s4P) O(3p5P)  →  O(3s5S) and molecular transitions N2(C,v‧)  →  N2(B,v″) \\text{N}2+ (B,v‧)  →  \\text{N}2+ (X,v″) allow us to obtain, as a function of the coupled power, the absolute densities of N(3p4S), O(3p5P), N2(C), N2(B) and \\text{N}2+ (B), as well as the gas (rotational) temperature (700-1000 K), the vibrational temperature of N2(C,v) (7000-10 000 K) and the excitation temperatures of N2(C) and N2(B) (11 000 K). The analysis of the H β line-width gives an upper limiting value of 1013 cm-3 for the electron density; its axial variation (4  ×  1011-6  ×  1012 cm-3) being estimated by solving the wave electrodynamics equations for the present geometry, plasma length and electron-neutral collision frequency. The experimental results were compared with the results from a 0D model, presented in companion paper I [1], which couples the system of rate balance equations for the dominant neutral and charged plasma species to the homogeneous two-term electron Boltzmann equation, taking the measured gas temperature and the estimated electron density as input parameters. Good qualitative agreement is found between the measurements and calculations of the local species densities for various powers and axial positions. The dissociation degree of oxygen is found above 10%. Moreover, both the measurements and calculations show evidence of the non-equilibrium behavior of low-temperature plasmas, with vibrational and excitation temperatures at least

  17. Monitoring trace metals in urban aerosols from Buenos Aires city. Determination by plasma-based techniques.

    Science.gov (United States)

    Smichowski, Patricia; Gómez, Dario R; Dawidowski, Laura E; Giné, María Fernanda; Bellato, Ana Claudia Sánchez; Reich, Silvia L

    2004-04-01

    A study was undertaken, within the framework of a 3 years national project, to assess the content of 13 elements in airborne particulate matter collected in representative zones of the metropolitan area of Buenos Aires. The sampling strategy followed consisted in collecting simultaneously 67 samples of PM10 particulate matter in 9 sampling sites covering an area of about 30 km2 during one week. The collection was performed on ash-free fibre-glass filters using high volume samplers. A combination of aqua regia and perchloric acid was used for leaching metals from filters. Key elements, namely Al, Ca, Cu, Fe, Mn, Mo, Ni, Pb, S, Sb, Sn, Zn and Zr, were determined by inductively coupled plasma-optical emission spectrometry (ICP-OES) and inductively coupled plasma-mass spectrometry (ICP-MS) at micro g g(-1) and ng g(-1) levels. Analyte concentration varied from 130 ng g(-1)(Mo) to over 30%(Ca). Multivariate statistical analysis was performed on the data set including the measured elemental compositions for the monitored period. The atmospheric concentration found for Pb confirms the decreasing levels of this element since the introduction of unleaded gasoline in 1995: 88 ng m(-3)(2001) gas imply low emissions of this element from combustion activities. To the best of our knowledge, S concentrations are reported for the first time for this city.

  18. Plasma decay in the afterglow of a high-voltage nanosecond discharge in air

    Science.gov (United States)

    Aleksandrov, N. L.; Anokhin, E. M.; Kindysheva, S. V.; Kirpichnikov, A. A.; Kosarev, I. N.; Nudnova, M. M.; Starikovskaya, S. M.; Starikovskii, A. Yu.

    2012-02-01

    The decay of air plasma produced by a high-voltage nanosecond discharge at room temperature and gas pressures in the range of 1-10 Torr was studied experimentally and theoretically. The time dependence of the electron density was measured with a microwave interferometer. The initial electron density was about 1012 cm-3. The discharge homogeneity was monitored using optical methods. The dynamics of the charged particle densities in the discharge afterglow was simulated by numerically solving the balance equations for electron and ions and the equation for the electron temperature. It was shown that, under these experimental conditions, plasma electrons are mainly lost due to dissociative and three-body recombination with ions. Agreement between the measured and calculated electron densities was achieved only when the rate constant of the three-body electron-ion recombination was increased by one order of magnitude and the temperature dependence of this rate constant was modified. This indicates that the mechanism for three-body recombination of molecular ions differs from that of the well-studied mechanism of atomic ion recombination.

  19. Plasma decay in the afterglow of a high-voltage nanosecond discharge in air

    Energy Technology Data Exchange (ETDEWEB)

    Aleksandrov, N. L.; Anokhin, E. M.; Kindysheva, S. V.; Kirpichnikov, A. A.; Kosarev, I. N.; Nudnova, M. M. [Moscow Institute of Physics and Technology (Russian Federation); Starikovskaya, S. M. [Ecole Polytechnique, route de Saclay (France); Starikovskii, A. Yu. [Princeton University (United States)

    2012-02-15

    The decay of air plasma produced by a high-voltage nanosecond discharge at room temperature and gas pressures in the range of 1-10 Torr was studied experimentally and theoretically. The time dependence of the electron density was measured with a microwave interferometer. The initial electron density was about 10{sup 12} cm{sup -3}. The discharge homogeneity was monitored using optical methods. The dynamics of the charged particle densities in the discharge afterglow was simulated by numerically solving the balance equations for electron and ions and the equation for the electron temperature. It was shown that, under these experimental conditions, plasma electrons are mainly lost due to dissociative and three-body recombination with ions. Agreement between the measured and calculated electron densities was achieved only when the rate constant of the three-body electron-ion recombination was increased by one order of magnitude and the temperature dependence of this rate constant was modified. This indicates that the mechanism for three-body recombination of molecular ions differs from that of the well-studied mechanism of atomic ion recombination.

  20. Microwave interrogation of an air plasma plume as a model system for hot spots in explosives

    Science.gov (United States)

    Kane, Ronald J.; Tringe, Joseph W.; Klunder, Gregory L.; Baluyot, Emer V.; Densmore, John M.; Converse, Mark C.

    2017-01-01

    The evolution of hot spots within explosives is critical to understand for predicting how detonation waves form and propagate. However, it is challenging to observe hot spots directly because they are small (˜micron diameter), form quickly (much less than a microsecond), and many explosives of interest are optically opaque. Microwaves are well-suited to characterize hot spots because they readily penetrate most explosives. They also have sufficient temporal and spatial resolution to measure the coalescence of an ensemble of hot spots inside explosives. Here we employ 94 GHz microwaves to characterize the evolution of individual plasma plumes formed by laser ionization of air. We use interferometry to obtain plume diameter as a function of time. Although the plasma plumes are larger than individual hot spots in explosives, they expand rapidly and predictably, and their structure can be optically imaged. They are therefore useful model systems to establish the spatial and temporal limits of microwave interferometry (MI) for understanding more complex hot spot behavior in solid explosives.

  1. Microwave air plasmas in capillaries at low pressure I. Self-consistent modeling

    Science.gov (United States)

    Coche, P.; Guerra, V.; Alves, L. L.

    2016-06-01

    This work presents the self-consistent modeling of micro-plasmas generated in dry air using microwaves (2.45 GHz excitation frequency), within capillaries (model couples the system of rate balance equations for the most relevant neutral and charged species of the plasma to the homogeneous electron Boltzmann equation. The maintenance electric field is self-consistently calculated adopting a transport theory for low to intermediate pressures, taking into account the presence of O- ions in addition to several positive ions, the dominant species being O{}2+ , NO+ and O+ . The low-pressure small-radius conditions considered yield very-intense reduced electric fields (˜600-1500 Td), coherent with species losses controlled by transport and wall recombination, and kinetic mechanisms strongly dependent on electron-impact collisions. The charged-particle transport losses are strongly influenced by the presence of the negative ion, despite its low-density (˜10% of the electron density). For electron densities in the range (1-≤ft. 4\\right)× {{10}12} cm-3, the system exhibits high dissociation degrees for O2 (˜20-70%, depending on the working conditions, in contrast with the  ˜0.1% dissociation obtained for N2), a high concentration of O2(a) (˜1014 cm-3) and NO(X) (5× {{10}14} cm-3) and low ozone production (<{{10}-3}% ).

  2. Treatment of airborne asbestos and asbestos-like microfiber particles using atmospheric microwave air plasma.

    Science.gov (United States)

    Averroes, A; Sekiguchi, H; Sakamoto, K

    2011-11-15

    Atmospheric microwave air plasma was used to treat asbestos-like microfiber particles that had two types of ceramic fiber and one type of stainless fiber. The treated particles were characterized via scanning electron microscopy (SEM) and X-ray diffraction (XRD). The experiment results showed that one type of ceramic fiber (Alumina:Silica=1:1) and the stainless fiber were spheroidized, but the other type of ceramic fiber (Alumina:Silica=7:3) was not. The conversion of the fibers was investigated by calculating the equivalent diameter, the aspect ratio, and the fiber content ratio. The fiber content ratio in various conditions showed values near zero. The relationship between the normalized fiber vanishing rate and the energy needed to melt the particles completely per unit surface area of projected particles, which is defined as η, was examined and seen to indicate that the normalized fiber vanishing rate decreased rapidly with the increase in η. Finally, some preliminary experiments for pure asbestos were conducted, and the analysis via XRD and phase-contrast microscopy (PCM) showed the availability of the plasma treatment.

  3. Factors affecting the microstructural stability and durability of thermal barrier coatings fabricated by air plasma spraying

    Energy Technology Data Exchange (ETDEWEB)

    Helminiak, M.A.; Yanar, N.M.; Pettit, F.S.; Meier, G.H. [National Energy Technology Laboratory, Pittsburgh, PA 15236 (United States); Department of Mechanical Engineering and Materials Science, University of Pittsburgh, 636 Benedum Hall, 3700 O& #x27; Hara Street, Pittsburgh, PA 15261 (United States); Taylor, T.A. [Praxair Surface Technologies, Inc., 1400 Polco Street, Indianapolis, IN 46224 (United States)

    2012-10-15

    The high-temperature behavior of high-purity, low-density (HP-LD) air plasma sprayed (APS) thermal barrier coatings (TBCs) with NiCoCrAlY bond coats deposited by argon-shrouded plasma spraying is described. The high purity yttria-stabilized zirconia resulted in top coats which are highly resistant to sintering and transformation from the metastable tetragonal phase to the equilibrium mixture of monoclinic and cubic phases. The thermal conductivity of the as-processed TBC is low but increases during high temperature exposure even before densification occurs. The porous topcoat microstructure also resulted in good spallation resistance during thermal cycling. The actual failure mechanisms of the APS coatings were found to depend on topcoat thickness, topcoat density, and the thermal cycle frequency. The failure mechanisms are described and the durability of the HP-LD coatings is compared with that of state-of-the-art electron beam physical vapor deposition TBCs. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  4. Production of geopolymers using glass produced from DC plasma treatment of air pollution control (APC) residues.

    Science.gov (United States)

    Kourti, Ioanna; Rani, D Amutha; Deegan, D; Boccaccini, A R; Cheeseman, C R

    2010-04-15

    Air pollution control (APC) residues are the hazardous waste produced from cleaning gaseous emissions at energy-from-waste (EfW) facilities processing municipal solid waste (MSW). APC residues have been blended with glass-forming additives and treated using DC plasma technology to produce a high calcium alumino-silicate glass. This research has investigated the optimisation and properties of geopolymers prepared from this glass. Work has shown that high strength geopolymers can be formed and that the NaOH concentration of the activating solution significantly affects the properties. The broad particle size distribution of the APC residue glass used in these experiments results in a microstructure that contains unreacted glass particles included within a geopolymer binder phase. The high calcium content of APC residues may cause the formation of some amorphous calcium silicate hydrate (C-S-H) gel. A mix prepared with S/L=3.4, Si/Al=2.6 and [NaOH]=6M in the activating solution, produced high strength geopolymers with compressive strengths of approximately 130 MPa. This material had high density (2070 kg/m(3)) and low porosity. The research demonstrates for the first time that glass derived from DC plasma treatment of APC residues can be used to form high strength geopolymer-glass composites that have potential for use in a range of applications.

  5. Study on structural, morphological and thermal properties of surface modified polyvinylchloride (PVC) film under air, argon and oxygen discharge plasma

    Science.gov (United States)

    Suganya, Arjunan; Shanmugavelayutham, Gurusamy; Serra Rodríguez, Carmen

    2016-09-01

    The effect of air, argon, oxygen DC glow discharge plasma on the polyvinylchloride (PVC) film synthesized by solution casting technique, were evaluated via changes in physio-chemical properties such as structural, morphological, crystalline, thermal properties. The PVC film was plasma treated as a function of exposure time and different plasma forming gases, while other operating parameters such as power and pressure remained constant at 100 W and 2 Pa respectively. The plasma treated PVC were characterized by static contact angle, ATR-FTIR, XPS, AFM and T-peel analysis. It was found that various gaseous plasma treatments have improved the polar components, surface roughness on the surface of PVC which was confirmed by XPS, AFM, resulting in highly enhanced wettability and adhesion. X-ray diffraction study showed that plasma treatment does not persuade considerable change, even though it vaguely induces the crystallinity. The thermal properties of plasma treated PVC were evaluated by Differential Scanning Calorimetry and it was observed that O2 plasma treatment gives higher glass transition temperature of 87.21 °C compared with the untreated one. The glass transition temperature slightly increased for Oxygen plasma treated material due to the presence of higher concentration of the polar functional groups on the PVC surface due to strong intramolecular bonding.

  6. Comparative Study on Antioxidative System in Normal and Vitrified Shoots of Populus suaveolens in Tissue Culture

    Institute of Scientific and Technical Information of China (English)

    Lin Shanzhi; Zhang Zhiyi; Lin Yuanzhen; Liu Wenfeng; Guo Huan; Zhang Wei; Zhang Chong

    2004-01-01

    To explore the physiological and biochemical mechanism of the occurrence of vitrified shoots of Populus suaveolens in tissue culture, the changes in water, chlorphyll, lignin, H2O2, phenylalanine ammonialyase (PAL), malonaldehyde (MDA), protective enzymatic systems, and some key enzymes involved in the ascorbate- glutathione cycle were comparatively studied in both normal and vitrified shoots of P. Suaveolens. The results show that the lower activities of peroxidase (POD), catalase (CAT), ascorbate peroxidase (APX), dehydroascorbate reductase (DHAR), glutathione reductase (GR) and PAL, and the less contents of chlorphyll, lignin, ascorbate (ASA) and reduced glutathione (GSH) as well as the lower ratios of ASA / DHA and GSH / GSSG are observed in vitrified shoots than in normal ones during the whole culture period. While in comparison with normal shoots, the higher activity of superoxide dismutase (SOD) and the more concentrations of water, H2O2, MDA, dehydroascorbate (DHA) and oxidized glutathione (GSSG) are found in vitrified shoots. Statistical analysis indicates that the enhanced activity of SOD and the decreased activities of CAT and POD as well as some enzymes involved in the ascorbate-glutathione cycle might be closely correlated to the accumulation of H2O2. The less regeneration of ASA and GSH and the lower capacity of the ascorbate-glutathione cycle observed in vitrified shoots might be due to a significant decrease in APX, MDAR, DHAR and GR activities and a decline in redox status of ASA and GSH. The decreases in chlorphyll content might result in a decline in photosynthesis. The lower activities of POD and PAL could result in the decrease of lignin synthesis and cell wall ligination, which might be the key factor leading to the increase in water content. It is concluded that the deficiency of detoxification capacity caused by the lower capacity of the ascorbate-glutathione pathway and the decreased activity of protective enzymatic system might lead to the

  7. Effects of humidity on the plasma-catalytic removal of low-concentration BTX in air

    Energy Technology Data Exchange (ETDEWEB)

    Fan Xing [School of Chemistry and Environment, Beihang University, No. 37, Xueyuan Road, Haidian District, Beijing 100191 (China); Zhu Tianle, E-mail: zhutl@buaa.edu.cn [School of Chemistry and Environment, Beihang University, No. 37, Xueyuan Road, Haidian District, Beijing 100191 (China); Wan Yajuan; Yan Xiao [School of Chemistry and Environment, Beihang University, No. 37, Xueyuan Road, Haidian District, Beijing 100191 (China)

    2010-08-15

    Effects of relative humidity (30%, 50% and 80% RH) on the removal of low-concentration benzene, toluene and p-xylene (BTX mixture) in air by non-thermal plasma (NTP) and the combination of NTP and MnO{sub x}/Al{sub 2}O{sub 3} catalyst (CPC) were systematically investigated in a link tooth wheel-cylinder plasma reactor. A long-term (150 h) CPC experiment under 30% RH was also conducted to investigate the stability of the catalyst. Results show that increasing humidity inhibits the O{sub 3} production in plasma and its decomposition over the catalyst. As for BTX conversion, increasing humidity suppresses the benzene conversion by both NTP and CPC; although higher humidity slightly promotes the toluene conversion by NTP, it negatively influences that by CPC; while the conversion of p-xylene by both NTP and CPC is insensitive to the humidity levels. Irrespective of the RH, the introduction of MnO{sub x}/Al{sub 2}O{sub 3} catalyst significantly promotes BTX conversion and improves the energy efficiency. On the other hand, CPC under 30% RH shows the best performance towards CO{sub x} formation during BTX oxidation processes. However, for a specific input energy of 10 J L{sup -1} in this study, organic intermediates generated and accumulated over the catalyst surface, resulting in a slight deactivation of the MnO{sub x}/Al{sub 2}O{sub 3} catalyst after 150-h reactions.

  8. Conversion of carbon disulfide in air by non-thermal plasma

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Xiao; Sun, Yifei [School of Chemistry and Environment, Beihang University, Beijing 100191 (China); Zhu, Tianle, E-mail: zhutl@buaa.edu.cn [School of Chemistry and Environment, Beihang University, Beijing 100191 (China); Fan, Xing [College of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100124 (China)

    2013-10-15

    Highlights: • The behavior of NTP for CS{sub 2} conversion in air was investigated. • CS{sub 2} conversion increase with the increase of specific input energy. • Short-living species are more important in CS{sub 2} conversion than long-living species. • The main gaseous products of CS{sub 2} conversion are CO, CO{sub 2}, OCS, SO{sub 2}, SO{sub 3} and H{sub 2}SO{sub 4}. • Y{sub CO{sub 2}} and Y{sub CO} increase, Y{sub SO{sub 3+H{sub 2SO{sub 4}}}} remains constant, and Y{sub SO{sub 2}} and Y{sub OCS} follow bell curves as SIE increases. -- Abstract: Carbon disulfide (CS{sub 2}), a typical odorous organic sulfur compound, has adverse effects on human health and is a potential threat to the environment. In the present study, CS{sub 2} conversion in air by non-thermal plasma (NTP) was systematically investigated using a link tooth wheel-cylinder plasma reactor energized by a DC power supply. The results show that corona discharge is effective in removing CS{sub 2}. The CS{sub 2} conversion increases with the increase of specific input energy (SIE). Both short-living (e.g. ·O, ·OH radicals) and long-living species contribute to the CS{sub 2} conversion, but the short-living species play a more important role. Both gaseous and solid products are formed during the conversion of CS{sub 2}. Gaseous products mainly include CO, CO{sub 2}, OCS, SO{sub 2}, SO{sub 3} and H{sub 2}SO{sub 4}. The yields of CO and CO{sub 2} increase, the yields of OCS and SO{sub 2} follow bell curves while the sum yield of SO{sub 3} and H{sub 2}SO{sub 4} remains constant as SIE increases. The solid products, consisting of CO{sub 3}{sup 2−}, SO{sub 4}{sup 2−} and possible polymeric sulfur, deposit on the inner wall and electrodes of the plasma reactor.

  9. Data mining of plasma peptide chromatograms for biomarkers of air contaminant exposures

    Directory of Open Access Journals (Sweden)

    Vincent Renaud

    2008-01-01

    Full Text Available Abstract Background Interrogation of chromatographic data for biomarker discovery becomes a tedious task due to stochastic variability in retention times arising from solvent and column performance. The difficulty is further compounded when the effects of exposure (e.g. to environmental contaminants and biological variability result in varying numbers and intensities of peaks among chromatograms. Results We developed a software tool to correct the stochastic time shifts in chromatographic data through iterative selection of landmark peaks and isometric interpolation to improve alignment of all chromatographic peaks. To illustrate application of the tool, plasma peptides from Fischer rats exposed for 4 h to clean air or Ottawa urban particles (EHC-93 were separated by HPLC with autofluorescence detection, and the retention time shifts between chromatograms were corrected (dewarped. Both dewarped and non-dewarped datasets were then mined for models containing peptide peaks that best discriminate among the treatment groups using ClinproTools™. In general, models generated by dewarped datasets were able to better classify test sample chromatograms into either clean air or EHC-93 exposure groups, and 0 or 24 h post-recovery time groups. Peak areas of peptides in a model that produced the best discrimination of treatment groups were analyzed by two-way ANOVA with exposure (clean air, EHC-93 and recovery time (0 h, 24 h as factors. Statistically significant (p Conclusion Our software tool provides a simple and portable approach for alignment of chromatograms with complex, bi-directional retention time shifts prior to data mining. Reliable biomarker discovery can be achieved through chromatographic dewarping using our software followed by pattern recognition by commercial data mining applications.

  10. Cold-air atmospheric pressure plasma against Clostridium difficile spores: a potential alternative for the decontamination of hospital inanimate surfaces.

    Science.gov (United States)

    Claro, Tânia; Cahill, Orla J; O'Connor, Niall; Daniels, Stephen; Humphreys, Hilary

    2015-06-01

    Clostridium difficile spores survive for months on environmental surfaces and are highly resistant to decontamination. We evaluated the effect of cold-air plasma against C. difficile spores. The single-jet had no effect while the multi-jet achieved 2-3 log10 reductions in spore counts and may augment traditional decontamination.

  11. Development of Polysulfone Hollow Fiber Porous Supports for High Flux Composite Membranes: Air Plasma and Piranha Etching

    Directory of Open Access Journals (Sweden)

    Ilya Borisov

    2017-02-01

    Full Text Available For the development of high efficiency porous supports for composite membrane preparation, polysulfone (PSf hollow fiber membranes (outer diameter 1.57 mm, inner diameter 1.12 mm were modified by air plasma using the low temperature plasma treatment pilot plant which is easily scalable to industrial level and the Piranha etch (H2O2 + H2SO4. Chemical and plasma modification affected only surface layers and did not cause PSf chemical structure change. The modifications led to surface roughness decrease, which is of great importance for further thin film composite (TFC membranes fabrication by dense selective layer coating, and also reduced water and ethylene glycol contact angle values for modified hollow fibers surface. Furthermore, the membranes surface energy increased two-fold. The Piranha mixture chemical modification did not change the membranes average pore size and gas permeance values, while air plasma treatment increased pore size 1.5-fold and also 2 order enhanced membranes surface porosity. Since membranes surface porosity increased due to air plasma treatment the modified membranes were used as efficient supports for preparation of high permeance TFC membranes by using poly[1-(trimethylsilyl-1-propyne] as an example for selective layer fabrication.

  12. Surface modification of polyester fabrics by atmospheric-pressure air/He plasma for color strength and adhesion enhancement

    Science.gov (United States)

    Zhang, Chunming; Zhao, Meihua; Wang, Libing; Qu, Lijun; Men, Yajing

    2017-04-01

    Surface properties of water-based pigmented inks for ink-jet printed polyester fabrics were modified with atmospheric-pressure air/He plasma to improve the color strength and pigment adhesion of the treated surfaces. The influence of various parameters, including the surface morphology, chemical compositions, surface energy and dynamic contact angles of the control and plasma treated samples was studied. Color strength and edge definition were used to evaluate the ink-jet printing performance of fabrics. The change in pigment adhesion to polyester fibers was analyzed by SEM (scanning electron microscopy). AFM (Atomic force microscope) and XPS (X-ray photoelectron spectroscopy) analyses indicated the increase in surface roughness and the oxygen-containing polar groups(Cdbnd O, Csbnd OH and COOH) reinforced the fixation of pigments on the fiber surface. The result from this study suggested that the improved pigment color yield was clearly affected by alteration of pigment adhesion enhanced by plasma surface modification. Polyester fabrics exhibited better surface property and ink-jet printing performance after the air/He mixture plasma treatment comparing with those after air plasma treatment.

  13. Chemical kinetics and relaxation of non-equilibrium air plasma generated by energetic photon and electron beams

    Science.gov (United States)

    Maulois, Melissa; Ribière, Maxime; Eichwald, Olivier; Yousfi, Mohammed; Azaïs, Bruno

    2016-04-01

    The comprehension of electromagnetic perturbations of electronic devices, due to air plasma-induced electromagnetic field, requires a thorough study on air plasma. In the aim to understand the phenomena at the origin of the formation of non-equilibrium air plasma, we simulate, using a volume average chemical kinetics model (0D model), the time evolution of a non-equilibrium air plasma generated by an energetic X-ray flash. The simulation is undertaken in synthetic air (80% N2 and 20% O2) at ambient temperature and atmospheric pressure. When the X-ray flash crosses the gas, non-relativistic Compton electrons (low energy) and a relativistic Compton electron beam (high energy) are simultaneously generated and interact with the gas. The considered chemical kinetics scheme involves 26 influent species (electrons, positive ions, negative ions, and neutral atoms and molecules in their ground or metastable excited states) reacting following 164 selected reactions. The kinetics model describing the plasma chemistry was coupled to the conservation equation of the electron mean energy, in order to calculate at each time step of the non-equilibrium plasma evolution, the coefficients of reactions involving electrons while the energy of the heavy species (positive and negative ions and neutral atoms and molecules) is assumed remaining close to ambient temperature. It has been shown that it is the relativistic Compton electron beam directly created by the X-ray flash which is mainly responsible for the non-equilibrium plasma formation. Indeed, the low energy electrons (i.e., the non-relativistic ones) directly ejected from molecules by Compton collisions contribute to less than 1% on the creation of electrons in the plasma. In our simulation conditions, a non-equilibrium plasma with a low electron mean energy close to 1 eV and a concentration of charged species close to 1013 cm-3 is formed a few nanoseconds after the peak of X-ray flash intensity. 200 ns after the flash

  14. Optical emission spectroscopy characterizations of micro-air plasma used for simulation of cell membrane poration

    Science.gov (United States)

    Zerrouki, A.; Motomura, H.; Ikeda, Y.; Jinno, M.; Yousfi, M.

    2016-07-01

    A micro-air corona discharge, which is one of the plasmas successfully used for gene transfection in terms of high transfection and cell viability rates, is characterized by optical emission spectroscopy. This non-equilibrium low temperature plasma is generated from the tip of a pulsed high voltage micro-tube (0.2 mm inner diameter and 0.7 mm for outer diameter) placed 2 mm in front of a petri dish containing deionized water and set on a grounded copper plate. The electron temperature, equal to about 6.75 eV near the electrode tip and decreased down to 3.4 eV near the plate, has been estimated, with an error bar of about 30%, from an interesting approach based on the experimental ratio of the closest nitrogen emission spectra of \\text{N}2+ (FNS) at 391.4 nm and N2(SPS) at 394.3 nm. This is based on one hand on a balance equation between creations and losses of the excited upper levels of these two UV spectra and on the other hand on the electron impact rates of the creation of these upper levels calculated from solution of the multi-term Boltzmann equation. Then using the measured Hα spectrum, electron density n e has been estimated from Stark broadening versus the inter-electrode position with an average error bar of about 50%. n e  ≈  1  ×  1015 cm-3 is near the tip coherent with the usual magnitude of electron density in the streamer head developed near the tip of the corona discharges. Rotational temperatures, estimated from comparison of synthetic and experimental spectra of OH(A  -  X), \\text{N}2+ (FNS) at 391.4 nm, and N2(SPS) at 337 nm are respectively equal to 2350 K, 2000 K and 700 K in the gap space. This clearly underlines a thermal non-equilibrium of the corresponding excited species generated inside the thin streamer filaments. But, due to the high dilution of these species in the background gas, these high rotational temperatures do not affect the mean gas temperature that remains close to 300

  15. On the thermodynamic properties of thermal plasma in the flame kernel of hydrocarbon/air premixed gases

    Science.gov (United States)

    Askari, Omid; Beretta, Gian Paolo; Eisazadeh-Far, Kian; Metghalchi, Hameed

    2016-07-01

    Thermodynamic properties of hydrocarbon/air plasma mixtures at ultra-high temperatures must be precisely calculated due to important influence on the flame kernel formation and propagation in combusting flows and spark discharge applications. A new algorithm based on the complete chemical equilibrium assumption is developed to calculate the ultra-high temperature plasma composition and thermodynamic properties, including enthalpy, entropy, Gibbs free energy, specific heat at constant pressure, specific heat ratio, speed of sound, mean molar mass, and degree of ionization. The method is applied to compute the thermodynamic properties of H2/air and CH4/air plasma mixtures for different temperatures (1000-100 000 K), different pressures (10-6-100 atm), and different fuel/air equivalence ratios within flammability limit. In calculating the individual thermodynamic properties of the atomic species needed to compute the complete equilibrium composition, the Debye-Huckel cutoff criterion has been used for terminating the series expression of the electronic partition function so as to capture the reduction of the ionization potential due to pressure and the intense connection between the electronic partition function and the thermodynamic properties of the atomic species and the number of energy levels taken into account. Partition functions have been calculated using tabulated data for available atomic energy levels. The Rydberg and Ritz extrapolation and interpolation laws have been used for energy levels which are not observed. The calculated plasma properties are then presented as functions of temperature, pressure and equivalence ratio, in terms of a new set of thermodynamically self-consistent correlations that are shown to provide very accurate fits suitable for efficient use in CFD simulations. Comparisons with existing data for air plasma show excellent agreement.

  16. Air plasma-material interactions at the oxidized surface of the PM1000 nickel-chromium superalloy

    Energy Technology Data Exchange (ETDEWEB)

    Panerai, Francesco, E-mail: panerai@vki.ac.be [Aeronautics and Aerospace Department, von Karman Institute for Fluid Dynamics, Chaussée de Waterloo 72, 1640 Rhode-Saint-Genèse (Belgium); Marschall, Jochen [Molecular Physics Program, SRI International, 333 Ravenswood Avenue, Menlo Park, CA 94025 (United States); Thömel, Jan [Aeronautics and Aerospace Department, von Karman Institute for Fluid Dynamics, Chaussée de Waterloo 72, 1640 Rhode-Saint-Genèse (Belgium); Vandendael, Isabelle; Hubin, Annick [Department of Materials and Chemistry, Research Group of Electrochemical and Surface Engineering, Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussels (Belgium); Chazot, Olivier [Aeronautics and Aerospace Department, von Karman Institute for Fluid Dynamics, Chaussée de Waterloo 72, 1640 Rhode-Saint-Genèse (Belgium)

    2014-10-15

    Highlights: • A detail investigation on behavior of a Ni–Cr superalloy under air plasma is proposed. • The response of PM1000 specimens at high temperature/low pressure is characterized. • High volatility of Cr{sub 2}O{sub 3} scale in presence of oxygen is found experimentally. • Stability of NiO scale at the surface is observed. • Computed thermodynamic volatility diagrams confirm the experimental observations. - Abstract: Nickel-based superalloys are promising options for the thermal protection systems of hypersonic re-entry vehicles operating under moderate aerothermal heating conditions. We present an experimental study on the interactions between PM1000, an oxide dispersion strengthened nickel-chromium superalloy, and air plasma at surface temperatures between 1000 and 1600 K and pressures of 1500, 7500 and 10,000 Pa. Pre-oxidized PM1000 specimens are tested in high-enthalpy reactive air plasma flows generated by the Plasmatron wind tunnel at the von Karman Institute for Fluid Dynamics. Microscopic analysis of plasma-exposed specimens shows enhanced damage to the chromia scale at the lowest plasma pressure. Elemental surface analysis reveals the loss of Cr and the enhancement of Ni at the scale surface. A thermodynamic analysis supports the accelerated volatilization of Cr{sub 2}O{sub 3} and the relative stability of NiO in the presence of atomic oxygen. Changes in the reflectance and emissivity of the oxidized surfaces due to plasma-exposure are presented. The catalytic efficiencies for dissociated air species recombination are determined as a function of surface temperature and pressure through a numerical rebuilding procedure and are compared with values presented in the literature for the same material.

  17. In vitro growth and development of isolated secondary follicles from vitrified caprine ovarian cortex.

    Science.gov (United States)

    Leal, Érica S S; Vieira, Luis A; Sá, Naíza A R; Silva, Gerlane M; Lunardi, Franciele O; Ferreira, Anna C A; Campello, Cláudio C; Alves, Benner G; Cibin, Francielli W S; Smitz, Johan; Figueiredo, José R; Rodrigues, Ana P R

    2017-08-03

    The aim of this study was to evaluate the viability, antrum formation and in vitro development of isolated secondary follicles from vitrified caprine ovarian cortex in a medium previously established for fresh isolated secondary follicles, in the absence (α-minimum essential medium (α-MEM+) alone) or presence of FSH and vascular endothelial growth factor (VEGF; α-MEM++FSH+VEGF). Ovarian fragments were distributed among five treatments (T1 to T5): fresh follicles were fixed immediately (T1), follicles from fresh tissue were cultured in vitro in α-MEM+ (T2) or α-MEM++FSH+VEGF (T3) and follicles from vitrified tissue were cultured in vitro in α-MEM+ (T4) or α-MEM++FSH+VEGF (T5). After 6 days of culture, treated follicles (T2, T3, T4 and T5) were evaluated for morphology, viability and follicular development (growth, antrum formation and proliferation of granulosa cells by Ki67 and argyrophilic nucleolar organiser region (AgNOR) staining). The levels of reactive oxygen species (ROS) in the culture media were also assessed. Overall, morphology of vitrified follicles was altered (P0.05). The average overall and daily follicular growth was highest (Ppositive for Ki67. However, fresh follicles from T3 had significantly higher AgNOR staining (P<0.05) compared with follicles of T1, T2, T4 and T5. In conclusion, secondary follicles can be isolated from vitrified and warmed ovarian cortex and survive and form an antrum when growing in an in vitro culture for 6 days.

  18. Taking the Blood Bank to the Field: The Design and Rationale of the Prehospital Air Medical Plasma (PAMPer) Trial.

    Science.gov (United States)

    Brown, Joshua B; Guyette, Francis X; Neal, Matthew D; Claridge, Jeffrey A; Daley, Brian J; Harbrecht, Brian G; Miller, Richard S; Phelan, Herb A; Adams, Peter W; Early, Barbara J; Peitzman, Andrew B; Billiar, Timothy R; Sperry, Jason L

    2015-01-01

    Hemorrhage and trauma induced coagulopathy remain major drivers of early preventable mortality in military and civilian trauma. Interest in the use of prehospital plasma in hemorrhaging patients as a primary resuscitation agent has grown recently. Trauma center-based damage control resuscitation using early and aggressive plasma transfusion has consistently demonstrated improved outcomes in hemorrhaging patients. Additionally, plasma has been shown to have several favorable immunomodulatory effects. Preliminary evidence with prehospital plasma transfusion has demonstrated feasibility and improved short-term outcomes. Applying state-of-the-art resuscitation strategies to the civilian prehospital arena is compelling. We describe here the rationale, design, and challenges of the Prehospital Air Medical Plasma (PAMPer) trial. The primary objective is to determine the effect of prehospital plasma transfusion during air medical transport on 30-day mortality in patients at risk for traumatic hemorrhage. This study is a multicenter cluster randomized clinical trial. The trial will enroll trauma patients with profound hypotension (SBP ≤ 70 mmHg) or hypotension (SBP 71-90 mmHg) and tachycardia (HR ≥ 108 bpm) from six level I trauma center air medical transport programs. The trial will also explore the effects of prehospital plasma transfusion on the coagulation and inflammatory response following injury. The trial will be conducted under exception for informed consent for emergency research with an investigational new drug approval from the U.S. Food and Drug Administration utilizing a multipronged community consultation process. It is one of three ongoing Department of Defense-funded trials aimed at expanding our understanding of the optimal therapeutic approaches to coagulopathy in the hemorrhaging trauma patient.

  19. Synthesis and Characterization of Diamond-vitrified Bond Sintered Composite By Spray-drying Method

    Directory of Open Access Journals (Sweden)

    HAO Su-ye

    2016-08-01

    Full Text Available Based on the diamond and inorganic sol, spray-drying method was used to prepare diamond-vitrified bond composite powders and then the bulk samples were obtained after pressing and sintering the powders. The surface morphology and particle size distribution of the composite powders were examined by scanning electron microscope and laser particle size analyzer,the sintering temperature of the composites was selected with the aid of the comprehensive thermal analysis instrument,the bending strength, fracture morphology and crystal phases of sintered samples prepared by spray-drying method and melting method were characterized by motorized bending tester, scanning electron microscope and X-ray diffraction, respectively. The results show that the composite powders prepared by spray-drying are spherical,which is beneficial to mould forming. Their wide size distribution helps to improve the density of diamond-vitrified bond green body. The sintering temperature of the composites is 820℃.The bonding and wrapping of diamond can be realized at this temperature. With the increase of bond content, the bending strength of sintered samples prepared by two methods increases and porosity decreases. When the vitrified bond content is 32%(mass fraction, the microstructure of samples prepared by spray-drying is uniform and is easy to be crystallized, and the bending strength and porosity are 99.46MPa and 38.55%;while for samples obtained from melting method, the corresponding figures are 72.42MPa and 39.89%.

  20. CHARACTERIZATION OF VITRIFIED SAVANNAH RIVER SITE SB4 WASTE SURROGATE PRODUCED IN COLD CRUCIBLE

    Energy Technology Data Exchange (ETDEWEB)

    Marra, J

    2008-08-05

    Savannah River Site (SRS) sludge batch 4 (SB4) waste surrogate with high aluminum and iron content was vitrified with commercially available Frit 503-R4 (8 wt.% Li{sub 2}O, 16 wt.% B2O3, 76 wt.% SiO{sub 2}) by cold crucible inductive melting using lab- (56 mm inner diameter), bench- (236 mm) and large-scale (418 mm) cold crucible. The waste loading ranged between 40 and 60 wt.%. The vitrified products obtained in the lab-scale cold crucible were nearly amorphous with traces of unreacted quartz in the product with 40 wt.% waste loading and traces of spinel phase in the product with 50 wt.% waste loading. The glassy products obtained in the bench-scale cold crucible are composed of major vitreous and minor iron-rich spinel phase whose content at {approx}60 wt.% waste loading may achieve {approx}10 vol.%. The vitrified waste obtained in the large-scale cold crucible was also composed of major vitreous and minor spinel structure phases. No nepheline phase has been found. Average degree of crystallinity was estimated to be {approx}12 vol.%. Anionic motif of the glass network is built from rather short metasilicate chains and boron-oxygen constituent based on boron-oxygen triangular units.

  1. Neonatal health including congenital malformation risk of 1072 children born after vitrified embryo transfer.

    Science.gov (United States)

    Belva, F; Bonduelle, M; Roelants, M; Verheyen, G; Van Landuyt, L

    2016-07-01

    Does vitrification of Day 3 and Day 5 embryos adversely affect birth outcomes of singletons and twins in comparison with peers born after fresh embryo transfer? Neonatal health parameters, including the prevalence of congenital malformations, in singletons and twins born after embryo vitrification are similar to or slightly better than after fresh embryo transfer. Although vitrification, rather than slow-freezing, of embryos is routine practice nowadays, convincing evidence regarding the safety for the offspring is sparse. Literature data comprise results from mostly small-sized studies or studies including only Day 3 or only Day 5 vitrified embryo transfers. Overall, better or comparable perinatal outcomes, in terms of higher birthweight and lower risk for small-for-gestational age or for low birthweight, have been reported for singletons born after vitrified embryo transfer compared with fresh embryo transfer. According to the single available study with sufficient sample size, the congenital malformation rate was found to be comparable after vitrified and fresh embryo transfers. Data were collected from 960 cycles after transfer of embryos vitrified on Day 3 (n = 457) or Day 5 (n = 503) and from 1644 cycles after fresh embryo transfer on Day 3 (n = 853) or Day 5 (n = 791), performed between 2008 and 2013 at the Centre for Reproductive Medicine of the university hospital UZ Brussel. Outcome measures were neonatal health in terms of birthweight, small-for-gestational age, prematurity rate, perinatal death and major/minor/total malformation rate. Perinatal health parameters of 11 stillborns and 1061 live borns (827 singletons and 234 twins) in the vitrified group and of 28 stillborns and 1838 live borns (1374 singletons and 464 twins) in the fresh embryo group are reported. Within 3 months after birth, children in the two study groups were assessed clinically with special attention to congenital malformations by a paediatrician blinded to the type of embryo

  2. Safety analysis report vitrified high level waste type B shipping cask

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-03-01

    This Safety Analysis Report describes the design, analyses, and principle features of the Vitrified High Level Waste (VHLW) Cask. In preparing this report a detailed evaluation of the design has been performed to ensure that all safety, licensing, and operational goals for the cask and its associated Department of Energy program can be met. The functions of this report are: (1) to fully document that all functional and regulatory requirements of 10CFR71 can be met by the package; and (2) to document the design and analyses of the cask for review by the Nuclear Regulatory Commission. The VHLW Cask is the reusable shipping package designed by GNSI under Department of Energy contract DE-AC04-89AL53-689 for transportation of Vitrified High Level Waste, and to meet the requirements for certification under 10CFR71 for a Type B(U) package. The VHLW cask has been designed as packaging for transport of canisters of Vitrified High Level Waste solidified at Department of Energy facilities.

  3. Stabilization of vitrified wastes: Task 4. Topical report, October 1994--September 1995

    Energy Technology Data Exchange (ETDEWEB)

    Nowok, J.W.; Pflughoeft-Hassett, D.F.; Hassett, D.J.; Hurley, J.P.

    1995-09-01

    The goal of this task was to work with private industry to refine existing vitrification processes to produce a more stable vitrified product. The initial objectives were to (1) demonstrate a waste vitrification procedure for enhanced stabilization of waste materials and (2) develop a testing protocol to understand the long-term leaching behavior of the stabilized waste form. The testing protocol was expected to be based on a leaching procedure called the synthetic groundwater leaching procedure (SGLP). This task will contribute to the US DOE`s identified technical needs in waste characterization, low-level mixed-waste processing, disposition technology, and improved waste forms. The proposed work was to proceed over 4 years in the following steps: literature surveys to aid in the selection and characterization of test mixtures for vitrification, characterization of optimized vitrified test wastes using advanced leaching protocols, and refinement and demonstration of vitrification methods leading to commercialization. For this year, literature surveys were completed, and computer modeling was performed to determine the feasibility of removing heavy metals from a waste during vitrification, thereby reducing the hazardous nature of the vitrified material and possibly producing a commercial metal concentrate. This report describes the following four subtasks: survey of vitrification technologies; survey of cleanup sites; selection and characterization of test mixtures for vitrification and crystallization; and selection of crystallization methods based on thermochemistry modeling.

  4. Analysis and experimental study on formation conditions of large-scale barrier-free diffuse atmospheric pressure air plasmas in repetitive pulse mode

    Science.gov (United States)

    Li, Lee; Liu, Lun; Liu, Yun-Long; Bin, Yu; Ge, Ya-Feng; Lin, Fo-Chang

    2014-01-01

    Atmospheric air diffuse plasmas have enormous application potential in various fields of science and technology. Without dielectric barrier, generating large-scale air diffuse plasmas is always a challenging issue. This paper discusses and analyses the formation mechanism of cold homogenous plasma. It is proposed that generating stable diffuse atmospheric plasmas in open air should meet the three conditions: high transient power with low average power, excitation in low average E-field with locally high E-field region, and multiple overlapping electron avalanches. Accordingly, an experimental configuration of generating large-scale barrier-free diffuse air plasmas is designed. Based on runaway electron theory, a low duty-ratio, high voltage repetitive nanosecond pulse generator is chosen as a discharge excitation source. Using the wire-electrodes with small curvature radius, the gaps with highly non-uniform E-field are structured. Experimental results show that the volume-scaleable, barrier-free, homogeneous air non-thermal plasmas have been obtained between the gap spacing with the copper-wire electrodes. The area of air cold plasmas has been up to hundreds of square centimeters. The proposed formation conditions of large-scale barrier-free diffuse air plasmas are proved to be reasonable and feasible.

  5. On-site application of air cleaner emitting plasma ion to reduce airborne contaminants in pig building

    Science.gov (United States)

    Cho, Man Su; Ko, Han Jong; Kim, Daekeun; Kim, Ki Youn

    2012-12-01

    The objective of this field study is to evaluate temporal reduction efficiency of air cleaner emitting plasma ion on airborne pollutants emitted from pig building. The operation principle of air cleaner based on plasma ion is that hydrogen atoms and oxygen ions combine to form hydroperoxyl radicals (HOO-), which surround and attach to surface of airborne microorganisms and eliminate them by breaking the hydrogen bond in their protein structure. In gaseous pollutants, it was found that there is no reduction effect of the air cleaner on ammonia and hydrogen sulfide (p > 0.05). In particulate pollutants, the air cleaner showed mean 79%(±6.1) and 78%(±3.0) of reduction efficiency for PM2.5. and PM1, respectively, compared to the control without air cleaner (p 0.05). In biological pollutants, the mean reduction efficiencies for airborne bacteria and fungi by application of air cleaner were 22%(±6.6) and 25%(±8.7), respectively (p effect on PM2.5, PM1, airborne bacteria and airborne fungi among airborne pollutants distributed in pig building while it did not lead to significant reduction of ammonia and hydrogen sulfide.

  6. Dyeing mechanism and optimization of polyamide 6,6 functionalized with double barrier discharge (DBD) plasma in air

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Fernando Ribeiro [Departamento de Engenharia Têxtil, Universidade Federal do Rio Grande do Norte UFRN, 59.072-970 Natal (Brazil); Zille, Andrea, E-mail: azille@2c2t.uminho.pt [2C2T – Centro de Ciência e Tecnologia Têxtil, Departamento de Engenharia Têxtil, Universidade do Minho, 4800-058 Guimarães (Portugal); Souto, Antonio Pedro [2C2T – Centro de Ciência e Tecnologia Têxtil, Departamento de Engenharia Têxtil, Universidade do Minho, 4800-058 Guimarães (Portugal)

    2014-02-28

    The physico-chemical improvements occasioned by DBD plasma discharge in dyeing process of polyamide 6,6 (PA66) fibers were investigated. The SEM, fluorescence microscopy, UV–vis spectroscopy, surface energy, FTIR, XPS and pH of aqueous extracts confirm the high polar functionalization of PA66 fibers due to plasma incorporation of oxygen atoms from atmospheric air. DBD plasma-generated reactive species preferentially break the C-N bonds, and not the aliphatic C-C chain of PA66. Formation of low-molecular weight acidic molecules that act as dye “carrier” and creation of micro-channels onto PA66 surface seems to favor dye diffusion into the fiber cores. Plasma treatment allows high level of direct dye diffusion and fixation in PA66 fibers at lower temperatures and shorter dyeing times than traditional dyeing methods.

  7. Inhibitory effect of silver nanoparticles mediated by atmospheric pressure air cold plasma jet against dermatophyte fungi.

    Science.gov (United States)

    Ouf, Salama A; El-Adly, Amira A; Mohamed, Abdel-Aleam H

    2015-10-01

    In an in vitro study with five clinical isolates of dermatophytes, the MIC(50) and MIC(100) values of silver nanoparticles (AgNPs) ranged from 5 to 16 and from 15 to 32 μg ml(- 1), respectively. The combined treatment of AgNPs with atmospheric pressure-air cold plasma (APACP) induced a drop in the MIC(50) and MIC100 values of AgNPs reaching 3-11 and 12-23 μg ml(- 1), respectively, according to the examined species. Epidermophyton floccosum was the most sensitive fungus to AgNPs, while Trichophyton rubrum was the most tolerant. AgNPs induced significant reduction in keratinase activity and an increase in the mycelium permeability that was greater when applied combined with plasma treatment. Scanning electron microscopy showed electroporation of the cell walls and the accumulation of AgNPs on the cell wall and inside the cells, particularly when AgNPs were combined with APACP treatment. An in vivo experiment with dermatophyte-inoculated guinea pigs indicated that the application of AgNPs combined with APACP was more efficacious in healing and suppressing disease symptoms of skin as compared with the application of AgNPs alone. The recovery from the infection reached 91.7 % in the case of Microsporum canis-inoculated guinea pigs treated with 13 μg ml(- 1) AgNPs combined with APACP treatment delivered for 2  min. The emission spectra indicated that the efficacy of APACP was mainly due to generation of NO radicals and excited nitrogen molecules. These reactive species interact and block the activity of the fungal spores in vitro and in the skin lesions of the guinea pigs. The results achieved are promising compared with fluconazole as reference antifungal drug.

  8. Effects of Atmospheric Pressure Air Plasma Pretreatment on the Seed Germination and Early Growth of Andrographis paniculata

    Science.gov (United States)

    Tong, Jiayun; He, Rui; Zhang, Xiaoli; Zhan, Ruoting; Chen, Weiwen; Yang, Size

    2014-03-01

    The objective of this paper is to demonstrate whether air plasma can change the seed germination characteristics, seedling emergence, as well as biochemical reactivity, in Andrographis paniculata (A. paniculata) seedlings by modifying the seed coat and finding a beneficial treatment dose. Eight treatment doses and one control were used to conduct electrical conductivity determination, a germination test, a seedling emergence test and a biochemical assay. The results showed that after being treated with air plasma excited at 5950 V for 10 s, the permeability of the seeds was improved significantly, resulting in the acceleration of seed germination and seedling emergence. In the meantime, the catalase activity and catalase isoenzyme expression were also improved, while the malondialdehyde content in the seedlings was decreased (which means greater counteraction with environmental stress). After being treated with 4250 V for 10 s and 5950 V for 20 s, the seed germination was enhanced, but without an obvious change in seedling emergence. However, after treatment with 3400 V for 20 s and 5100 V for 10 s, the permeability of the seeds was decreased, resulting in a delay in seedling emergence. These results indicate that air plasma can change the physiological and biochemical characteristics of Andrographis paniculata seeds by modifying the seed coat, combined with the effects of the active plasma species, and that different treating doses have different effects.

  9. Plasma decay in air excited by high-voltage nanosecond discharge

    Science.gov (United States)

    Aleksandrov, Nikolay; Anokhin, Eugeny; Kindusheva, Svetlana; Kirpichnikov, Artem; Kosarev, Ilya; Nudnova, Maryia; Starikovskaia, Svetlana; Starikovskiy, Andrey; mipt Team

    2011-10-01

    Plasma decay in air after a high-voltage nanosecond discharge has been studied experimentally and numerically at room temperature for pressures between 1 and 10 Torr. Time-resolved electron density was measured by a microwave interferometer for initial electron densities in the range (2-3) × 1012 cm-3. Discharge non-uniformity was investigated by optical methods. The balance equations for charged particles and electron temperature were numerically solved to describe the temporal evolution of the densities of electrons and ions in the discharge afterglow. It was shown that the loss of electrons is governed by dissociative and three-body recombination with O2+ions under the conditions considered. Good agreement between the calculated and measured electron density histories could be obtained only when increasing the rate of three-body recombination by an order of magnitude and when changing the dependence of the recombination rate on electron temperature. This could testify that the well-known mechanism of three-body recombination of atomic ions changes in the case of molecular ions.

  10. Geopolymers prepared from DC plasma treated air pollution control (APC) residues glass: properties and characterisation of the binder phase.

    Science.gov (United States)

    Kourti, Ioanna; Devaraj, Amutha Rani; Bustos, Ana Guerrero; Deegan, David; Boccaccini, Aldo R; Cheeseman, Christopher R

    2011-11-30

    Air pollution control (APC) residues have been blended with glass-forming additives and treated using DC plasma technology to produce a high calcium aluminosilicate glass (APC glass). This has been used to form geopolymer-glass composites that exhibit high strength and density, low porosity, low water absorption, low leaching and high acid resistance. The composites have a microstructure consisting of un-reacted residual APC glass particles imbedded in a complex geopolymer and C-S-H gel binder phase, and behave as particle reinforced composites. The work demonstrates that materials prepared from DC plasma treated APC residues have potential to be used to form high quality pre-cast products.

  11. Oxidation of metals by a plasma formed as a result of low-threshold breakdown of air

    Science.gov (United States)

    Goncharov, I. N.; Goncharov, Yu N.; Konov, Vitalii I.; Minaev, I. M.; Skvortsov, Yu A.; Chapliev, N. I.

    1981-12-01

    The characteristics of the oxidation of copper, aluminum, and titanium were determined in the case when breakdown of air was initiated by CO2 laser pulses incident on targets made of these metals. A study was made of the influence of surface oxide films on the threshold radiation intensity necessary to produce a plasma. The dependence of the efficiency of the thermal interaction of an optical-breakdown plasma on the magnitude and sign of the charge carried by the surface of a metal target was investigated for the first time in the specific case of titanium.

  12. Influence of ambient air on the flowing afterglow of an atmospheric pressure Ar/O2 radiofrequency plasma

    CERN Document Server

    Duluard, C Y; Hubert, J; Reniers, F

    2016-01-01

    The influence of ambient air on the flowing afterglow of an atmospheric pressure Ar/O2 radiofrequency plasma has been investigated experimentally. Spatially resolved mass spectrometry and laser induced fluorescence on OH radicals were used to estimate the intrusion of air in between the plasma torch and the substrate as a function of the torch-to-substrate separation distance. No air is detected, within the limits of measurement uncertainties, for separation distances smaller than 5 mm. For larger distances, the effect of ambient air can no longer be neglected, and radial gradients in the concentrations of species appear. The Ar 4p population, determined through absolute optical emission spectroscopy, is seen to decrease with separation distance, whereas a rise in emission from the N2(C--B) system is measured. The observed decay in Ar 4p and N2(C) populations for separation distances greater than 9mm is partly assigned to the increasing collisional quenching rate by N2 and O2 molecules from the entrained air....

  13. Comparison of ectopic pregnancy risk among transfers of embryos vitrified on day 3, day 5, and day 6.

    Science.gov (United States)

    Du, Tong; Chen, Hong; Fu, Rong; Chen, Qiuju; Wang, Yun; Mol, Ben W; Kuang, Yanping; Lyu, Qifeng

    2017-07-01

    To compare ectopic pregnancy risk among transfers of embryos vitrified on day 3, day 5, and day 6. Retrospective cohort study. Academic tertiary-care medical center. A total of 10,736 pregnancies after 23,730 frozen-thawed embryo transfer (FET) cycles of in vitro fertilization/intracytoplasmic sperm injection from March 2003 to May 2015. The ectopic pregnancy rate was compared among pregnancies resulting from transfers of embryos vitrified on day 3, day 5, and day 6. Generalized estimation equation regression models were used to calculate unadjusted and adjusted odds ratios and 95% confidence intervals for the association between ectopic pregnancy and selected patient and treatment characteristics. We studied this association in both the group that achieved pregnancy and the group that underwent an FET cycle. Odds of ectopic pregnancy. The overall rate of ectopic pregnancy was 2.8% (304/10,736). Ectopic pregnancy rates after day-3, day-5, and day-6 vitrified embryo transfers were 3.1% (287/9,224), 2.0% (11/562), and 0.6% (6/950), respectively. After adjusting for confounders, the risks of ectopic pregnancy in day-3 and day-5 vitrified embryo transfers were both significantly higher than in day-6 vitrified embryo transfers. The associations were similar when we did calculations per cycle. In women undergoing FET, day-6 vitrified embryo transfer is associated with a significantly lower risk of ectopic pregnancy than both day-3 and day-5 vitrified embryo transfers. Copyright © 2017 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  14. Successful pregnancy following transfer of feline embryos derived from vitrified immature cat oocytes using 'stepwise' cryoprotectant exposure technique.

    Science.gov (United States)

    Tharasanit, Theerawat; Manee-In, Sukanya; Buarpung, Sirirak; Chatdarong, Kaywalee; Lohachit, Chainarong; Techakumphu, Mongkol

    2011-11-01

    Oocyte cryopreservation is the desired tool for the 'long-term' storage of female genetic potential especially for endangered/valuable species. This study aims at examining the ability of different cryoprotectant (CPA) and CPA exposure techniques to protect immature feline oocytes against cryoinjury during vitrification. Immature oocytes were submitted to different CPA exposure techniques: 1) 2-step DMSO, 2) 4-step DMSO, 3) 2-step EG, 4) 4-step EG, 5) 2-step EG plus DMSO and 6) 4-step EG plus DMSO. Non-CPA treated, non-vitrified oocytes served as controls. The oocytes were then submitted either to in vitro maturation (Experiment 1, n = 334) or to vitrification/warming (Experiment 2, n = 440). The stage of nuclear maturation was subsequently determined. In Experiment 3, the vitrified immature oocytes (n = 254) were matured and fertilized in vitro, and their developmental competence was assessed. A total of 424 embryos derived from vitrified immature oocytes were transferred into the oviduct of 6 recipient queens (Experiment 4). Vitrification reduced significantly the meiotic and developmental competence of immature cat oocytes compared with the non-vitrified controls. The EG alone or a combination of EG and DMSO yielded higher maturation rates than DMSO, irrespective of the CPA equilibration techniques used. The 4-step EG vitrification resulted in the highest maturation rate (37.6%) but cleavage and blastocyst rates were significantly lower than the non-vitrified controls (24.8% and 30.2% vs 62.5% and 49.3%, respectively). Pregnancy was established in recipients receiving embryos derived from non-vitrified and vitrified/warmed immature oocytes. It is concluded that the stepwise CPA exposure technique can be successfully applied for vitrification of immature cat oocytes, in terms of in vitro development but it is likely to affect in utero development.

  15. Plasma Kinetics in Electrical Discharge in Mixture of Air, Water and Ethanol Vapors for Hydrogen Enriched Syngas Production

    CERN Document Server

    Shchedrin, A I; Ryabtsev, A V; Chernyak, V Ya; Yukhymenko, V V; Olszewski, S V; Naumov, V V; Prysiazhnevych, I V; Solomenko, E V; Demchina, V P; Kudryavtsev, V S

    2008-01-01

    The complex theoretical and experimental investigation of plasma kinetics of the electric discharge in the mixture of air and ethanol-water vapors is carried out. The discharge was burning in the cavity, formed by air jets pumping between electrodes, placed in aqueous ethanol solution. It is found out that the hydrogen yield from the discharge is maximal in the case when ethanol and water in the solution are in equal amounts. It is shown that the hydrogen production increases with the discharge power and reaches the saturation at high value. The concentrations of the main stable gas-phase components, measured experimentally and calculated numerically, agree well in the most cases.

  16. Effect of streamer plasma air purifier on sbs symptoms and performance of office work

    DEFF Research Database (Denmark)

    Zhang, X.J.; Fang, Lei; Wargocki, Pawel;

    2011-01-01

    level of air pollution. Intensity of SBS symptoms were indicated using visual-analogue scales. Subjects’ performance was evaluated with several computer tasks. The results show that operation of the air purifiers improved perceived air quality and reduced the odor intensity of indoor air. Eye dryness...

  17. Effect of air plasma treatment on the dyeing of Tencel fabric with C.I. Reactive Black 5

    Science.gov (United States)

    Zhang, L. S.; Liu, H. L.; Yu, W. D.

    2015-02-01

    The Tencel fabrics were treated by the atmospheric pressure plasma with air for different length of time and dyed with the C.I. Reactive Black 5 at 1%, 5% and 10% o.m.f. The effect of the prolonged plasma treatment time was characterized by both the weight loss and the whiteness index analyses, which implied that with the increase of the plasma treatment time, the treated fabrics were lighter and yellower than the untreated ones. The contact angle decreased dramatically from 139° to instantly spread. The results of SEM showed that, with the prolonged treatment time, more significant crater-like surface morphology on the fiber of Tencel samples was formed. Compared with untreated samples, the values of dye bath exhaustion and total fixation effect were higher. But they did not increase with the prolonged plasma treatment time. With the prolonged storage time after the plasma treatment, the result to ageing effect indicated that the values of dye bath exhaustion and total fixation effect reduced. The Integ values for characterizing the coloring effect were evaluated by the CIE system of color measurement. In most cases, the Integ values reached the highest ones when the plasma treatment time was 10 or 20 min. When the concentration of the dye bath was low (at 1% o.m.f.), the longer plasma treatment time was, the higher the Integ value was. However, if the fabrics after plasma treatment were stored for 21 days, the longer plasma treatment time did not cause the larger Integ value. When the concentration was 1%, the Integ value increased with the weight loss increasing, which was different from the values of fabrics with 5% and 10% concentration. If the dyeing concentration was low, the fixation had a more significant effect on the color fastness to wet rubbing; in contrast, if the dyeing concentration was high, the surface roughness had a more important effect on it.

  18. Improvement of Polytetrafluoroethylene Surface Energy by Repetitive Pulse Non-Thermal Plasma Treatment in Atmospheric Air%Improvement of Polytetrafluoroethylene Surface Energy by Repetitive Pulse Non-Thermal Plasma Treatment in Atmospheric Air

    Institute of Scientific and Technical Information of China (English)

    杨国清; 张冠军; 张文元

    2011-01-01

    Improvement of polytetrafluoroethylene surface energy by non-thermal plasma treatment is presented, using a nanosecond-positive-edge repetitive pulsed dielectric barrier discharge generator in atmospheric air. The electrical parameters including discharging power, peak and density of micro-discharge current were calculated, and the electron energy was estimated. Surface treatment experiments of polytetrafluoroethylene films were conducted for both different applied voltages and different treating durations. Results show that the surface energy of polytetrafluoroethylene film could be improved to 40 mJ/m2 or more by plasma treatment. Surface roughness measurement and surface X-ray photoelectron spectroscopy analysis indicate that there are chemical etching and implantation of polar oxygen groups in the sample surface treating process, resulting in the improvement of the sample surface energy. Compared with an AC source of 50 Hz, the dielectric barrier discharges generated by a repetitive pulsed source could provide higher peak power, lower mean power, larger micro-discharge current density and higher electron energy. Therefore, with the same applied peak voltage and treating duration, the improvement of polytetrafluoroethylene surface energy using repetitive pulsed plasma is more effective, and the plasma treatment process based on repetitive pulsed dielectric barrier discharges in air is thus feasible and applicable.

  19. Investigation of ambient air species diffusion into the effluent of an atmospheric pressure plasma jet by measurements and modeling

    Science.gov (United States)

    Schmidt-Bleker, Ansgar; Reuter, Stephan; Winter, Jörn; Lange, Hartmut; Weltmann, Klaus-Dieter; Leibniz InstitutePlasma Science; Technology (INP) Greifswald Team

    2011-10-01

    The diffusion of ambient air species into the effluent of a cold atmospheric pressure plasma (CAP) jet operated with pure argon is quantified using both experimental methods and theoretical estimations by a convection-diffusion approach. In the effluent of CAP jets operated in ambient air, reactive oxygen species (ROS) and reactive nitrogen species (RNS) are generated. ROS and RNS are believed to play a central role in biomedical applications of low temperature atmospheric pressure plasmas. The inflow of atmospheric oxygen is determined by a novel absorption technique in the VUV spectral range, where emission originating from within the discharge is used as light source. An analytic expression for the estimation of the on-axis density of ambient species was obtained assuming a stationary drift-diffusion equation and is compared to complete numerical results. The easy to use expression correlates well with the experimental results obtained.

  20. Surface Treatment of Polypropylene Films Using Homogeneous DBD Plasma at Atmospheric Pressure in Air%Surface Treatment of Polypropylene Films Using Homogeneous DBD Plasma at Atmospheric Pressure in Air

    Institute of Scientific and Technical Information of China (English)

    FANG Zhi; CAI Ling-ling; LEI Xiao; QIU Yu-chang; Kuffel Edmund

    2011-01-01

    The homogeneous dielectric barrier discharge (DBD) in atmospheric air is most favorable for polymer sur- face modification due to the low cost of operation and the ability of ambient on-line continuous uniform processing. In this paper, polypropylene (PP) films are treated using a homogeneous DBD plasma in atmospheric air. The surface properties of PP films are studied using contact angle and surface energy measurement, scanning electron microscopy (SEM) and Fourier trailsformed infrared spectroscopy (FTIR), and the aging effect after treatment when the treated materials are exposed to open air is also studied, with the modification mechanism being discussed. It is demonstrated that non thermal plasmas generated by homogeneous DBD in atmospheric air is an effective way to enhance the surface properties of PP films. After the pIasma treatment, the surface of PP film is etched, and oxygen-containing polar groups are introduced into the surface. These two processes can induce a remarkable decrease in water contact angle and a remarkable increase in surface energy, and the surface properties of PP films are improved accordingly.

  1. Inactivation of a 25.5 µm Enterococcus faecalis biofilm by a room-temperature, battery-operated, handheld air plasma jet

    Science.gov (United States)

    Pei, X.; Lu, X.; Liu, J.; Liu, D.; Yang, Y.; Ostrikov, K.; Chu, Paul K.; Pan, Y.

    2012-04-01

    Effective biofilm inactivation using a handheld, mobile plasma jet powered by a 12 V dc battery and operated in open air without any external gas supply is reported. This cold, room-temperature plasma is produced in self-repetitive nanosecond discharges with current pulses of ˜100 ns duration, current peak amplitude of ˜6 mA and repetition rate of ˜20 kHz. It is shown that the reactive plasma species penetrate to the bottom layer of a 25.5 µm-thick Enterococcus faecalis biofilm and produce a strong bactericidal effect. This is the thickest reported biofilm inactivated using room-temperature air plasmas.

  2. Comparison of pulsating DC and DC power air-water plasma jet: A method to decrease plume temperature and increase ROS

    Science.gov (United States)

    Liu, K.; Hu, H.; Lei, J.; Hu, Y.; Zheng, Z.

    2016-12-01

    Most air-water plasma jets are rich in hydroxyl radicals (•OH), but the plasma has higher temperatures, compared to that of pure gas, especially when using air as working gas. In this paper, pulsating direct current (PDC) power was used to excite the air-water plasma jet to reduce plume temperature. In addition to the temperature, other differences between PDC and DC plasma jets are not yet clear. Thus, comparative studies of those plasmas are performed to evaluate characteristics, such as breakdown voltage, temperature, and reactive oxygen species. The results show that the plume temperature of PDC plasma is roughly 5-10 °C lower than that of DC plasma in the same conditions. The •OH content of PDC is lower than that of DC plasma, whereas the O content of PDC plasma is higher. The addition of water leads in an increase in the plume temperature and in the production of •OH with two types of power supplies. The production of O inversely shows a declining tendency with higher water ratio. The most important finding is that the PDC plasma with 100% water ratio achieves lower temperature and more abundant production of •OH and O, compared with DC plasma with 0% water ratio.

  3. Plasma channels during filamentation of a femtosecond laser pulse with wavefront astigmatism in air

    Energy Technology Data Exchange (ETDEWEB)

    Dergachev, A A; Kandidov, V P; Shlenov, S A [Lomonosov Moscow State University, Faculty of Physics, Moscow (Russian Federation); Ionin, A A; Mokrousova, D V; Seleznev, L V; Sinitsyn, D V; Sunchugasheva, E S; Shustikova, A P [P N Lebedev Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation)

    2014-12-31

    We have demonstrated experimentally and numerically the possibility of controlling parameters of plasma channels formed during filamentation of a femtosecond laser pulse by introducing astigmatism in the laser beam wavefront. It is found that weak astigmatism increases the length of the plasma channel in comparison with the case of aberration-free focusing and that strong astigmatism can cause splitting of the plasma channel into two channels located one after another on the filament axis. (interaction of laser radiation with matter. laser plasma)

  4. Vitrified sheep isolated secondary follicles are able to grow and form antrum after a short period of in vitro culture.

    Science.gov (United States)

    Lunardi, Franciele Osmarini; Chaves, Roberta Nogueira; de Lima, Laritza Ferreira; Araújo, Valdevane Rocha; Brito, Ivina Rocha; Souza, Carlos Eduardo Azevedo; Donato, Mariana Aragão Matos; Peixoto, Christina Alves; Dinnyes, Andras; Campello, Cláudio Cabral; de Figueiredo, José Ricardo; Rodrigues, Ana Paula Ribeiro

    2015-10-01

    The risk of reintroducing malignant cells after ovarian graft into patients following post-cancer treatment is an obstacle for clinical applications (autotransplantation). In this context, in vitro follicle culture would be an alternative to transplantation in order to minimize such risks. Therefore, the aim of this study was to compare the development of secondary follicles after vitrification in isolated form (without stroma) with vitrification in in situ form (within fragments of ovarian tissue). Follicles were first isolated from ovarian fragments from mixed-breed ewes and then vitrified; these comprised the Follicle-Vitrification group (Follicle-Vit), or fragments of ovarian tissue were first vitrified, followed by isolation of the follicles, resulting in the Tissue-Vitrification group (Tissue-Vit). Control and vitrified groups were submitted to in vitro culture (6 days) and follicular morphology, viability, antrum formation, follicle and oocyte diameter, growth rate, ultrastructural characteristics and cell proliferation were evaluated. The percentages of morphologically normal follicles and antrum formation were similar among groups. Follicular viability and oocyte diameter were similar between Follicle-Vit and Tissue-Vit. The follicular diameter and growth rate of Follicle-Vit were similar to the Control, while those of Tissue-Vit were significantly lower compared to the Control. Both vitrified groups had an augmented rate of granulosa cellular proliferation compared to Control. Secondary follicles can be successfully vitrified before or after isolation from the ovarian tissue without impairing their ability to survive and grow during in vitro culture.

  5. Characterization of atmospheric pressure plasma treated pure cashmere and wool/cashmere textiles: Treatment in air/water vapor mixture

    Energy Technology Data Exchange (ETDEWEB)

    Zanini, Stefano, E-mail: stefano.zanini@mib.infn.it [Università degli Studi di Milano-Bicocca, Dipartimento di Fisica “G. Occhialini”, p.za della Scienza, 3, I-20126 Milano (Italy); Grimoldi, Elisa [Università degli Studi di Milano-Bicocca, Dipartimento di Fisica “G. Occhialini”, p.za della Scienza, 3, I-20126 Milano (Italy); Citterio, Attilio [Politecnico di Milano, Dipartimento di Chimica, Materiali ed Ingegneria Chimica “G. Natta”, Via Mancinelli 7, I-20131 Milano (Italy); Riccardi, Claudia, E-mail: riccardi@mib.infn.it [Università degli Studi di Milano-Bicocca, Dipartimento di Fisica “G. Occhialini”, p.za della Scienza, 3, I-20126 Milano (Italy)

    2015-09-15

    Highlights: • We treated cashmere and wool/cashmere textiles with atmospheric pressure plasma. • Wettability of the fabrics was increased. • The increment in wettability derived from a surface oxidation of the fibers. • Only minor etching effects were observed with scanning electron microscopy. - Abstract: We performed atmospheric pressure plasma treatments of pure cashmere and wool/cashmere textiles with a dielectric barrier discharge (DBD) in humid air (air/water vapor mixtures). Treatment parameters have been optimized in order to enhance the wettability of the fabrics without changing their bulk properties as well as their touch. A deep characterization has been performed to study the wettability, the surface morphologies, the chemical composition and the mechanical properties of the plasma treated textiles. The chemical properties of the plasma treated samples were investigated with attenuated total reflectance Fourier transform infrared (FTIR/ATR) spectroscopy and X-ray photoelectron microscopy (XPS). The analyses reveal a surface oxidation of the treated fabrics, which enhances their surface wettability. Morphological characterization of the treated fibers with scanning electron microscopy (SEM) reveals minor etching effects, an essential feature for the maintenance of the textile softness.

  6. Study of Nanodispersed Iron Oxides Produced in Steel Drilling by Contracted Electric-Arc Air Plasma Torch

    Institute of Scientific and Technical Information of China (English)

    P. STEFANOV; D. GALANOV; G. VISSOKOV; D. PANEVA; B. KUNEV; I. MITOV

    2008-01-01

    The optimal conditions on the plasma-forming gas flowrate, discharge current and voltage, distance between the plasma-torch nozzle and the metal plate surface for the process of penetration in and vaporization of steel plates by the contracted electric-arc air plasma torch accompanied by water quenching, were determined. The X-ray structural and phase studies as well as M6ssbauer and electron microscope studies on the samples treated were performed. It was demonstrated that the vaporized elemental iron was oxidized by the oxygen present in the air plasma jet to form iron oxides (wiistite, magnetite, hematite), which, depending on their mass ra-tios, determined the color of the iron oxide pigments, namely, beginning from light yellow, through deep yellow, light brown, deep brown, violet, red-violet, to black. A high degree of dispersity of the iron oxides is thus produced, with an averaged diameter of the particles below 500 nm, and their defective crystal structure form the basis of their potential application as components of iron-containing catalysts and pigments.

  7. Study of Nanodispersed Iron Oxides Produced in Steel Drilling by Contracted Electric-Arc Air Plasma Torch

    Science.gov (United States)

    Stefanov, P.; Galanov, D.; Vissokov, G.; Paneva, D.; Kunev, B.; Mitov, I.

    2008-06-01

    The optimal conditions on the plasma-forming gas flowrate, discharge current and voltage, distance between the plasma-torch nozzle and the metal plate surface for the process of penetration in and vaporization of steel plates by the contracted electric-arc air plasma torch accompanied by water quenching, were determined. The X-ray structural and phase studies as well as Mössbauer and electron microscope studies on the samples treated were performed. It was demonstrated that the vaporized elemental iron was oxidized by the oxygen present in the air plasma jet to form iron oxides (wüstite, magnetite, hematite), which, depending on their mass ratios, determined the color of the iron oxide pigments, namely, beginning from light yellow, through deep yellow, light brown, deep brown, violet, red-violet, to black. A high degree of dispersity of the iron oxides is thus produced, with an averaged diameter of the particles below 500 nm, and their defective crystal structure form the basis of their potential application as components of iron-containing catalysts and pigments.

  8. Study of nanosecond discharges in different H2 air mixtures at atmospheric pressure for plasma-assisted applications

    Science.gov (United States)

    Bourdon, Anne; Kobayashi, Sumire; Bonaventura, Zdenek; Tholin, Fabien; Popov, Nikolay

    2016-09-01

    This paper presents 2D simulations of nanosecond pulsed discharges between two point electrodes in different H2/air mixtures and in air at atmospheric pressure. A fluid model is coupled with detailed kinetic schemes for air and different H2/air mixtures to simulate the discharge dynamics. First, as the positive and negative ionization waves propagate in the interelectrode gap, it has been observed that in H2/air mixtures with equivalence ratios between 0.3 and 2, major positive ions produced by the nanosecond discharge are N2+,O2+and HN2+.The discharge dynamics is shown to vary only slightly for equivalence ratios of the H2/air mixture between 0.3 and 2. Then, as the discharge transits to a nanosecond spark discharge, we have studied the different chemical reactions that lead to fast gas heating and to the production of radicals, as O,H and OH. Both thermal and chemical effects of the nanosecond spark discharge are of interest for plasma assisted combustion applications. This work has been supported by the project DRACO (Grant No. ANR-13-IS09-0004) and the french russian LIA Kappa.

  9. Comparison of concomitant outcome achieved with fresh and cryopreserved donor oocytes vitrified by the Cryotop method.

    Science.gov (United States)

    Cobo, Ana; Kuwayama, Masashigue; Pérez, Sonia; Ruiz, Amparo; Pellicer, Antonio; Remohí, José

    2008-06-01

    To evaluate the outcome of oocyte vitrification using the Cryotop method, observed in an egg donation program by simultaneously evaluating embryos derived from vitrified and fresh oocytes coming from the same stimulated cycle. Cohort prospective randomized study. Instituto Valenciano de Infertilidad (IVI) Valencia, Spain. Thirty oocyte donors and 30 recipients with informed consents. Vitrification by the Cryotop method. Warming 1 hour after vitrification. Microinjection of surviving MII and fresh oocytes, evaluation of fertilization, embryo development, and clinical results. Survival, fertilization, and cleavage rate. Embryo quality, pregnancy rate (PR), and implantation rate. Survival rate observed was 96.7%. There was no difference in fertilization rates (76.3% and 82.2%), day 2 cleavage (94.2% and 97.8%), day 3 cleavage (80.8% and 80.5%), and blastocyst formation (48.7% and 47.5%) for vitrified and fresh oocytes, respectively. Embryo quality on day 3 and on day 5-6 were similar for vitrification and fresh oocyte group (80.8% vs. 80.5% and 81.1% vs. 70%, respectively). A total of 23 embryo transfers were carried out in the vitrification group. Pregnancy rates, implantation rates, miscarriage rates, and ongoing PR were 65.2%, 40.8%, 20%, and 47.8%, respectively. The Cryotop method preserves the potential of vitrified oocytes to fertilize and further develop, which is similar, when evaluated simultaneously, to fresh counterparts. Excellent clinical outcome indicates the possible use of this technology for egg donation programs, as well as a high potential for establishing oocyte banking.

  10. Functionalization of graphene by atmospheric pressure plasma jet in air or H{sub 2}O{sub 2} environments

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Weixin [Radiation Laboratory, University of Notre Dame, Notre Dame, IN 46556 (United States); Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556 (United States); Ptasinska, Sylwia, E-mail: Sylwia.Ptasinska.1@nd.edu [Radiation Laboratory, University of Notre Dame, Notre Dame, IN 46556 (United States); Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States)

    2016-03-30

    Graphical abstract: - Highlights: • Facile plasma approach was used to functionalize graphene in air or in H{sub 2}O{sub 2} solution. • For the first time, observation of graphene reduction was observed in oxidative surrounding. • N-doping of graphene in H{sub 2}O{sub 2} solution occurred during the APPJ treatment. • H{sub 2}O{sub 2} solution acted as a buffer layer to prevent graphene etching. • Increase in resistance of the plasma-treated graphene was measured. • The transition of the material property from semi-metallic to semiconducting was revealed in the four-point probe measurement manifested by an increase in sheet resistance of the plasma-treated graphene. - Abstract: The functionalization of graphene, which deforms its band structure, can result in a metal-semiconductor transition. In this work, we report a facile strategy to oxidize single-layer graphene using an atmospheric pressure plasma jet (APPJ) that generates a variety of reactive plasma species at close to ambient temperature. We systematically characterized the oxygen content and chemical structure of the graphene films after plasma treatment under different oxidative conditions (ambient air atmosphere or hydrogen peroxide solution) by X-ray Photoelectron Spectroscopy (XPS). Plasma-treated graphene films containing more than 40% oxygen were obtained in both oxidative environments. Interestingly, prolonged irradiation led to the reduction of graphene oxides. N-doping of graphene also occurred during the APPJ treatment in H{sub 2}O{sub 2} solution; the nitrogen content of the doped graphene was dependent on the duration of irradiation and reached up to 8.1% within 40 min. Moreover, the H{sub 2}O{sub 2} solution served as a buffer layer that prevented damage to the graphene during plasma irradiation. Four-point probe measurement revealed an increase in sheet resistance of the plasma-treated graphene, indicating the transition of the material property from semi-metallic to semiconducting.

  11. Formation of oxygen vacancies and Ti3+ state in TiO2 thin film and enhanced optical properties by air plasma treatment

    OpenAIRE

    Bandna Bharti; Santosh Kumar; Heung-No Lee; Rajesh Kumar

    2016-01-01

    This is the first time we report that simply air plasma treatment can also enhances the optical absorbance and absorption region of titanium oxide (TiO2) films, while keeping them transparent. TiO2 thin films having moderate doping of Fe and Co exhibit significant enhancement in the aforementioned optical properties upon air plasma treatment. The moderate doping could facilitate the formation of charge trap centers or avoid the formation of charge recombination centers. Variation in surface s...

  12. Experimental and numerical analysis of atmospheric air plasma induced by multi-MeV pulsed X-ray

    Science.gov (United States)

    Maulois, Mélissa; Ribière, Maxime; Eichwald, Olivier; Yousfi, Mohammed; Pouzalgues, Romain; Garrigues, Alain; Delbos, Christophe; Azaïs, Bruno

    2016-10-01

    Quantification of electromagnetic stresses on electronic systems, following irradiation of the air by ionizing radiations, requires a thorough study of the plasma generated. In this work, the temporal evolution of non-equilibrium air plasmas self-induced by energetic X-rays is experimentally and theoretically investigated at atmospheric pressure. Time resolved electron density measurements are based on transmission measurements of an electromagnetic wave in the microwave range. The electromagnetic wave is launched into a wave guide, which is irradiated by a high flux of multi-MeV pulsed X-rays. For different X-ray fluxes, the electron density is determined from the comparison between the transmitted microwave signal at the waveguide output, and the result of the calculation of the propagation of an electromagnetic wave through time varying plasma contained in a waveguide. These measurements require a priori assumptions on electron temperature, which is obtained and confirmed by a reaction kinetics model of the evolution of the electron energy and the densities of the different humid air plasma species inside the waveguide. The considered chemical kinetics scheme involves 39 influent species (electrons, positive ions, negative ions, and neutral atoms and molecules in their ground or metastable excited states) reacting following 265 selected reactions. A good agreement is observed between the calculated and measured time evolution of the transmitted signal for specific profiles of electron energy and density. In our experiments, the maximum electron density is of the order of few 1012 cm-3, for a mean electron energy of about 0.5 eV. For doses range from 3 Gy to 21 Gy, the discrepancies between the measurements and the model for the maximum of the electron density are within a factor of 2.

  13. Stabilization of a premixed methane-air flame with a high repetition nanosecond laser-induced plasma

    Science.gov (United States)

    Yu, Yang; Li, Xiaohui; An, Xiaokang; Yu, Xin; Fan, Rongwei; Chen, Deying; Sun, Rui

    2017-07-01

    Laser-induced plasma ignition has been applied in various combustion systems, however, work on flame stabilization with repetitive laser-induced plasma (LIP) is rather limited. In this paper, stabilization of a premixed methane-air flame with a high repetition nanosecond LIP is reported. The plasma energy coupling and the temporal evolution of the flame kernels generated by the LIPs are investigated with different laser repetition rates, i.e., 1 Hz, 100 Hz and 250 Hz, respectively. The plasma energy coupling is not affected in the air flow and in the premixed methane-air flow with the applied laser repetition rates. Continuous combustion flame stabilization has been achieved with LIPs of 100 Hz and 250 Hz, in terms of catch-up and merging of the consecutive flame kernels. The flame kernel formed by the last LIP does not affect the evolution of the newly formed flame kernel by the next LIP. The catch-up distance, defined as the distance from the LIP initiation site to the flame kernel catch-up position, is estimated for different laser repetition rates based on the temporal evolution of the flame kernels. A higher laser repetition rate will lead to a shorter catch-up distance which is beneficial for flame stabilization. The up limit for the laser repetition rate to realize effective flame stabilization is determined from the critical inter-pulse delay defined from the onset of the LIP to the return of the initially contraflow propagating lower front to the LIP initiation site. The up limit is 377 Hz under the flow conditions of this work (equivalence ratio of 1, flow speed of 2 m/s, and Reynolds number of 1316).

  14. Characteristics of surface-wave plasma with air-simulated N2 O2 gas mixture for low-temperature sterilization

    Science.gov (United States)

    Xu, L.; Nonaka, H.; Zhou, H. Y.; Ogino, A.; Nagata, T.; Koide, Y.; Nanko, S.; Kurawaki, I.; Nagatsu, M.

    2007-02-01

    Sterilization experiments using low-pressure air discharge plasma sustained by the 2.45 GHz surface-wave have been carried out. Geobacillus stearothermoplilus spores having a population of 3.0 × 106 were sterilized for only 3 min using air-simulated N2-O2 mixture gas discharge plasma, faster than the cases of pure O2 or pure N2 discharge plasmas. From the SEM analysis of plasma-irradiated spores and optical emission spectroscopy measurements of the plasmas, it has been found that the possible sterilization mechanisms of air-simulated plasma are the chemical etching effect due to the oxygen radicals and UV emission from the N2 molecules and NO radicals in the wavelength range 200-400 nm. Experiment suggested that UV emission in the wavelength range less than 200 nm might not be significant in the sterilization. The UV intensity at 237.0 nm originated from the NO γ system (A 2Σ+ → X 2Π) in N2-O2 plasma as a function of the O2 percentage added to N2-O2 mixture gas has been investigated. It achieved its maximum value when the O2 percentage was roughly 10-20%. This result suggests that air can be used as a discharge gas for sterilization, and indeed we have confirmed a rapid sterilization with the actual air discharge at a sample temperature of less than 65 °C.

  15. Nonsurgical deep uterine transfer of vitrified, in vivo-derived, porcine embryos is as effective as the default surgical approach.

    Science.gov (United States)

    Martinez, Emilio A; Martinez, Cristina A; Nohalez, Alicia; Sanchez-Osorio, Jonatan; Vazquez, Juan M; Roca, Jordi; Parrilla, Inmaculada; Gil, Maria A; Cuello, Cristina

    2015-06-01

    Surgical procedures are prevalent in porcine embryo transfer (ET) programs, where the use of vitrified embryos is quasi non-existent. This study compared the effectiveness of surgical vs nonsurgical deep uterine (NsDU) ET using vitrified, in vivo-derived embryos (morulae and blastocysts) on the reproductive performance and welfare of the recipients. The recipient sows (n=122) were randomly assigned to one of the following groups: surgical ET with 30 vitrified-warmed embryos (S-30 group, control); NsDU-ET with 30 vitrified-warmed embryos (NsDU-30 group) and NsDU-ET with 40 vitrified-warmed embryos (NsDU-40 group). Regardless of embryo stage, the NsDU-ET with 40 embryos presented similar rates of farrowing (72.7%) and litter size (9.9 ± 2.1 piglets) as the customary surgical procedure (75.0% and 9.6 ± 2.7 piglets). Numbers of ET-embryos appeared relevant, since the NsDU-ET with 30 embryos resulted in a decrease (P<0.05) in farrowing rates (38.9%) and litter sizes (5.7 ± 2.4 piglets). In conclusion, we demonstrate for the first time that farrowing rate and litter size following a NsDU-ET procedure increase in function of a larger number of transferred vitrified embryos, with fertility equalizing that obtained with the invasive surgical approach. The results open new possibilities for the widespread use of non-invasive ET in pigs.

  16. Expression of Folliculogenesis-Related Genes in Vitrified Human Ovarian Tissue after Two Weeks of In Vitro Culture

    Directory of Open Access Journals (Sweden)

    Zahra Shams Mofarahe

    2017-01-01

    Full Text Available Objective This study was designed to evaluate the effects of vitrification and in vitro culture of human ovarian tissue on the expression of oocytic and follicular cell-related genes. Materials and Methods In this experimental study, ovarian tissue samples were obtained from eight transsexual women. Samples were cut into small fragments and were then assigned to vitrified and non-vitrified groups. In each group, some tissue fragments were divided into un-cultured and cultured (in α-MEM medium for 2 weeks subgroups. The normality of follicles was assessed by morphological observation under a light microscope using hematoxylin and eosin (H&E staining. Expression levels of factor in the germ line alpha (FIGLA, KIT ligand (KL, growth differentiation factor 9 (GDF-9 and follicle stimulating hormone receptor (FSHR genes were quantified in both groups by real-time reverse transcriptase polymerase chain reaction (RT-PCR at the beginning and the end of culture. Results The percentage of normal follicles was similar between non-cultured vitrified and non-vitrified groups (P>0.05, however, cultured tissues had significantly fewer normal follicles than non-cultured tissues in both vitrified and non-vitrified groups (P<0.05. In both cultured groups the rate of primary and secondary follicles was significantly higher than non-cultured tissues (P<0.05. The expression of all examined genes was not significantly altered in both non-cultured groups. Whiles, in comparison with cultured tissues non-cultured tissues, the expression of FIGLA gene was significantly decreased, KL gene was not changed, GDF-9 and FSHR genes was significantly increased (P<0.05. Conclusion Human ovarian vitrification following in vitro culture has no impairing effects on follicle normality and development and expression of related-genes. However, in vitro culture condition has deleterious effects on normality of follicles.

  17. 空气等离子镀覆技术的进展%Development of Air-plasma Spraying Technology

    Institute of Scientific and Technical Information of China (English)

    В.Я.Фролов; Г.К.Петров; Б.А.Юшин; Д.В.Иванов

    2014-01-01

    The air-plasma spraying technology has been found application in many fields .In recent years , research on both establishment of plasma generator and spraying process has been performed in the St .Petersburg State Polytechnic University , and many types of coatings , which may not only be used to protect freshly made parts but also to restore worn parts , have been developed .The theoretical and experimental investigations conducted by the St.Petersburg State Polytechnic University in conjunction with the Leibnits ( INP Greifswald ) Plasma and Technology Research Institute will allow amount of experimental work to be appreciably reduced in developing the plasma generator and the air-plasma spraying process .%空气等离子喷涂工艺在许多领域得到了应用。近年来,国立圣彼得堡综合技术大学在等离子体发生器的创建和涂覆工艺方面进行了研究,业已研制成多种涂层,既可用于新制零件的防护,也可用于磨损件的修复。国立圣彼得堡综合技术大学和雷波尼茨( INP Greifswald )等离子体及工艺研究院联合进行的理论和试验研究,可显著减少研发等离子体发生器和空气等离子涂覆工艺的试验工作量。

  18. Lessons learned in demonstration projects regarding operational safety during final disposal of vitrified waste and spent fuel

    Energy Technology Data Exchange (ETDEWEB)

    Filbert, Wolfgang; Herold, Philipp [DBE Technology GmbH, Peine (Germany)

    2015-07-01

    The paper summarizes the lessons learned in demonstration projects regarding operational safety during the final disposal of vitrified waste and spent fuel. The three demonstration projects for the direct disposal of vitrified waste and spent fuel are described. The first two demonstration projects concern the shaft transport of heavy payloads of up to 85 t and the emplacement operations in the mine. The third demonstration project concerns the borehole emplacement operation. Finally, open issues for the next steps up to licensing of the emplacement and disposal systems are summarized.

  19. In vitro production of buffalo embryos from stepwise vitrified immature oocytes

    Directory of Open Access Journals (Sweden)

    Saber Mohammed Abd-Allah

    2009-09-01

    Full Text Available This study was conducted to produce buffalo embryos in vitro from stepwise vitrified immature oocytes. Cumulus oocyte complexes (COCs were obtained from the ovaries of slaughtered buffalo and were collected from the local abattoir. Selected COCs were exposed to a vitrification solution consisting of 40% ethylene glycol (EG plus 0.3 M trehalose and 20% polyvinyl pyrrolidone (PVP for 1 min and loaded in 0.25 ml plastic mini-straws containing 100 µl of 10% sucrose. The loaded cryostraws were cryopreserved by stepwise vitrification and were stored in liquid nitrogen for 4 to 6 months. Data analysis revealed a high percentage of post-thawing morphologically normal immature oocytes (80.7% with a low percentage of damaged oocytes. There were no significant differences in the maturation (82.1%, cleavage (47.6% and buffalo embryo development (15.4% produced by the stepwise vitrified immature oocytes in comparison to the three observations in fresh oocytes (88.3%, 50.4% and 19.4%, respectively, p<0.05.

  20. Clinical outcomes of single versus double blastocyst transfer in fresh and vitrified-warmed cycles.

    Science.gov (United States)

    Eum, Jin Hee; Park, Jae Kyun; Kim, So Young; Paek, Soo Kyung; Seok, Hyun Ha; Chang, Eun Mi; Lee, Dong Ryul; Lee, Woo Sik

    2016-09-01

    Assisted reproductive technology has been associated with an increase in multiple pregnancies. The most effective strategy for reducing multiple pregnancies is single embryo transfer. Beginning in October 2015, the National Supporting Program for Infertility in South Korea has limited the number of embryos that can be transferred per in vitro fertilization (IVF) cycle depending on the patient's age. However, little is known regarding the effect of age and number of transferred embryos on the clinical outcomes of Korean patients. Thus, this study was performed to evaluate the effect of the number of transferred blastocysts on clinical outcomes. This study was carried out in the Fertility Center of CHA Gangnam Medical Center from January 2013 to December 2014. The clinical outcomes of 514 women who underwent the transfer of one or two blastocysts on day 5 after IVF and of 721 women who underwent the transfer of one or two vitrified-warmed blastocysts were analyzed retrospectively. For both fresh and vitrified-warmed cycles, the clinical pregnancy rate and live birth or ongoing pregnancy rate were not significantly different between patients who underwent elective single blastocyst transfer (eSBT) and patients who underwent double blastocyst transfer (DBT), regardless of age. However, the multiple pregnancy rate was significantly lower in the eSBT group than in the DBT group. The clinical outcomes of eSBT and DBT were equivalent, but eSBT had a lower risk of multiple pregnancy and is, therefore, the best option.

  1. Air plasma or UV-irradiation applied to surface modification of pectin/poly(vinyl alcohol) blends

    Science.gov (United States)

    Kowalonek, Jolanta; Kaczmarek, Halina; Dąbrowska, Aldona

    2010-10-01

    Poly(vinyl alcohol), pectin and their blends with different components ratio were exposed to low-temperature air plasma or high energy UV-irradiation ( λ = 254 nm) for the purpose of surface modification. The physico-chemical changes in surface properties have been studied by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and contact angle measurements. Surface free energy of polymeric films, its polar and dispersive components have been calculated by Owens-Wendt method. Moreover, the work of adhesion was estimated and the recovery of hydrophobic properties of modified films after storage have been also studied. The few seconds air-plasma treatment caused more effective surface modification than 5-6 h UV-irradiation. The observed changes were partially reversible, contrary to these caused by photo-modification. It was found that pectin/PVA (50:50) blend was characterised by larger susceptibility to plasma modification compared to pure pectin and pure PVA, whereas the photosensitivity to radiation of 254 nm wavelength was the lowest for this specimen in comparison to other studied samples.

  2. Development of open air silicon deposition technology by silane-free atmospheric pressure plasma enhanced chemical transport under local ambient gas control

    Science.gov (United States)

    Naito, Teruki; Konno, Nobuaki; Yoshida, Yukihisa

    2016-07-01

    Open air silicon deposition was performed by combining silane-free atmospheric pressure plasma-enhanced chemical transport and a newly developed local ambient gas control technology. The effect of air contamination on silicon deposition was investigated using a vacuum chamber, and the allowable air contamination level was confirmed to be 3 ppm. The capability of the local ambient gas control head was investigated numerically and experimentally. A safe and clean process environment with air contamination less than 1 ppm was achieved. Combining these technologies, a microcrystalline silicon film was deposited in open air, the properties of which were comparable to those of silicon films deposited in a vacuum chamber.

  3. Flow-field differences and electromagnetic-field properties of air and N2 inductively coupled plasmas

    Science.gov (United States)

    Yu, Minghao; Yamada, Kazuhiko; Takahashi, Yusuke; Liu, Kai; Zhao, Tong

    2016-12-01

    A numerical model for simulating air and nitrogen inductively coupled plasmas (ICPs) was developed considering thermochemical nonequilibrium and the third-order electron transport properties. A modified far-field electromagnetic model was introduced and tightly coupled with the flow field equations to describe the Joule heating and inductive discharge phenomena. In total, 11 species and 49 chemical reactions of air, which include 5 species and 8 chemical reactions of nitrogen, were employed to model the chemical reaction process. The internal energy transfers among translational, vibrational, rotational, and electronic energy modes of chemical species were taken into account to study thermal nonequilibrium effects. The low-Reynolds number Abe-Kondoh-Nagano k-ɛ turbulence model was employed to consider the turbulent heat transfer. In this study, the fundamental characteristics of an ICP flow, such as the weak ionization, high temperature but low velocity in the torch, and wide area of the plasma plume, were reproduced by the developed numerical model. The flow field differences between the air and nitrogen ICP flows inside the 10-kW ICP wind tunnel were made clear. The interactions between the electromagnetic and flow fields were also revealed for an inductive discharge.

  4. Role of the NAD(P)H quinone oxidoreductase NQR and the cytochrome b AIR12 in controlling superoxide generation at the plasma membrane.

    Science.gov (United States)

    Biniek, Catherine; Heyno, Eiri; Kruk, Jerzy; Sparla, Francesca; Trost, Paolo; Krieger-Liszkay, Anja

    2017-04-01

    The quinone reductase NQR and the b-type cytochrome AIR12 of the plasma membrane are important for the control of reactive oxygen species in the apoplast. AIR12 and NQR are two proteins attached to the plant plasma membrane which may be important for generating and controlling levels of reactive oxygen species in the apoplast. AIR12 (Auxin Induced in Root culture) is a single gene of Arabidopsis that codes for a mono-heme cytochrome b. The NADPH quinone oxidoreductase NQR is a two-electron-transferring flavoenzyme that contributes to the generation of O 2(•-) in isolated plasma membranes. A. thaliana double knockout plants of both NQR and AIR12 generated more O 2(•-) and germinated faster than the single mutant affected in AIR12. To test whether NQR and AIR12 are able to interact functionally, recombinant purified proteins were added to plasma membranes isolated from soybean hypocotyls. In vitro NADH-dependent O 2(•-) production at the plasma membrane in the presence of NQR was reduced upon addition of AIR12. Electron donation from semi-reduced menadione to AIR12 was shown to take place. Biochemical analysis showed that purified plasma membrane from soybean hypocotyls or roots contained phylloquinone and menaquinone-4 as redox carriers. This is the first report on the occurrence of menaquinone-4 in eukaryotic photosynthetic organisms. We propose that NQR and AIR12 interact via the quinone, allowing an electron transfer from cytosolic NAD(P)H to apoplastic monodehydroascorbate and control thereby the level of reactive oxygen production and the redox state of the apoplast.

  5. A New Waste Disposal Technology-plasma arc Pyrolysis System

    Institute of Scientific and Technical Information of China (English)

    黄建军; 施嘉标; 梁荣庆; 刘正之

    2003-01-01

    This paper introduces a new waste disposal technology with plasma arc. Being different from conventional combustion or burning such as incineration, it is based on a process called controlled pyrolysis-thermal destruction and recovery process. It has four advantages, they are completely safe, clean, high-energy synthesis gas, non-toxic vitrified slag and metal.

  6. Iron Phosphate Glass for Vitrifying Hanford AZ102 LAW in Joule Heated and Cold Crucible Induction Melters - 12240

    Energy Technology Data Exchange (ETDEWEB)

    Day, Delbert E.; Brow, Richard K.; Ray, Chandra S.; Reis, Signo T. [Missouri University of Science and Technology, 1870 Miner Circle, Rolla, MO 65409 (United States); Kim, Cheol-Woon [MO-SCI Corporation, 4040 HyPoint North, Rolla, MO 65401 (United States); Vienna, John D.; Sevigny, Gary [Pacific North West National Laboratory, Battelle Blvd., Richland, WA 99352 (United States); Peeler, David; Johnson, Fabienne C.; Hansen, Eric K. [Savannah River National Laboratory, Savannah River Site, 999-W, Aiken, SC 29803 (United States); Soelberg, Nick [Idaho National Laboratory, 2525 Fremont Avenue, Idaho Falls, ID 83415 (United States); Pegg, Ian L.; Gan, Hao [Catholic University of America, 620 Michigan Avenue, N.E., Washington, DC 20064 (United States)

    2012-07-01

    An iron phosphate composition for vitrifying a high sulfate (∼17 wt%) and high alkali (∼80 wt%) Hanford low activity waste (LAW), known as AZ-102 LAW, has been developed for processing in a Joule Heated Melter (JHM) or a Cold Crucible Induction Melter (CCIM). This composition produced a glass waste form, designated as MS26AZ102F-2, with a waste loading of 26 wt% of the AZ-102 which corresponded to a total alkali and sulfate (represented as SO{sub 3}) content of 21 and 4.4 wt%, respectively. A slurry (7 M Na{sup +}) of MS26AZ102F-2 simulant was melted continuously at temperatures between 1030 and 1090 deg. C for 10 days in a small JHM at PNNL and for 70 hours in a CCIM at INL. The as-cast glasses produced in both melters and in trial laboratory experiments along with their canister centerline cooled (CCC) counterparts met the requirements for the Product Consistency Test (PCT) and the Vapor Hydration Test (VHT) responses in the Hanford Tank Waste Treatment and Immobilization Plant (WTP) Contract. These glass waste forms retained up to 77 % of the SO{sub 3} (3.3 wt%), 100% of the Cesium, and 33 to 44% of the rhenium (used as a surrogate for Tc) all of which either exceeded or were comparable to the retention limit for these species in borosilicate glass nuclear waste form. Analyses of commercial K-3 refractory lining and the Inconel 693 metal electrodes used in JHM indicated only minimum corrosion of these components by the iron phosphate glass. This is the first time that an iron phosphate composition was melted continuously in a slurry fed JHM and in the US, thereby, demonstrating that iron phosphate glasses can be used as alternative hosts for vitrifying nuclear waste. The following conclusions are drawn from the results of the present work. (1) An iron phosphate composition, designated as MS26AZ102F-2, containing 26 wt% of the simulated high sulfate (17 wt%), high alkali (80 wt%) Hanford AZ-102 LAW meets all the criteria for processing in a JHM and CCIM. This

  7. Improving anti-felting characteristics of Merino wool fiber by 2.5 MHz atmosphere pressure air plasma

    Science.gov (United States)

    Chandwani, Nisha; Dave, Purvi; Jain, Vishal; Nema, Sudhir; Mukherjee, Subroto

    2017-04-01

    The present work investigates the effect of high frequency (2.5 MHz) Dielectric Barrier Discharge (DBD) in air on surface characteristics of Merino wool as a function of plasma exposure time (5s to 15s). The FE-SEM (Field Emission Scanning Electron Microscopy), EDS (Energy Dispersive X-ray spectrum) and Derivative ATR-FTIR (Attenuated Total Reflection- Fourier Transform Infrared) Spectroscopy are used to study physio-chemical changes induced by plasma. These physio-chemical properties of fibers can be co-related with the felting behaviour of the wool fiber, which leads to shrinkage and pilling of garments while laundering. Felting occurs mainly because of presence of outermost hydrophobic cuticle layer having sharp scales. The FE-SEM analysis of wool fiber surface reveals that cuticle scales on wool fiber become blunt after plasma processing. The ATR-FTIR analysis along with second order derivative spectroscopy demonstrates the cleavage of di-sulphide bonds of cuticle and formation of sulphur-oxygen groups such as Cystine Sulphonate (-S-SO3-), cysteic acid (-SO3-), cystine monoxide(-SO-S-), cysteine di-oxide (-SO2-S-). A possible explanation about how the combined effect of morphological and chemical changes induced by plasma results in minimizing the felting of wool fibers is discussed.

  8. Comparison of atmospheric air plasmas excited by high-voltage nanosecond pulsed discharge and sinusoidal alternating current discharge

    Science.gov (United States)

    Zhang, Shuai; Wang, Wen-chun; Jiang, Peng-chao; Yang, De-zheng; Jia, Li; Wang, Sen

    2013-10-01

    In this paper, atmospheric pressure air discharge plasma in quartz tube is excited by 15 ns high-voltage nanosecond pulsed discharge (HVNPD) and sinusoidal alternating current discharge (SACD), respectively, and a comparison study of these two kinds of discharges is made through visual imaging, electrical characterization, optical detection of active species, and plasma gas temperature. The peak voltage of the power supplies is kept at 16 kV while the pulse repetition rate of nanosecond pulse power supply is 100 Hz, and the frequency of sinusoidal power supply is 10 kHz. Results show that the HVNPD is uniform while the SACD presents filamentary mode. For exciting the same cycles of discharge, the average energy consumption in HVNPD is about 1/13 of the SACD. However, the chemical active species generated by the HVNPD is about 2-9 times than that excited by the SACD. Meanwhile, the rotational and vibrational temperatures have been obtained via fitting the simulated spectrum of N2 (C3Πu → B3Πg, 0-2) with the measured one, and the results show that the plasma gas temperature in the HVNPD remains close to room temperature whereas the plasma gas temperature in the SACD is about 200 K higher than that in HVNPD in the initial phase and continually increases as discharge exposure time goes on.

  9. Functionalization of Hydrogen-free Diamond-like Carbon Films using Open-air Dielectric Barrier Discharge Atmospheric Plasma Treatments

    Energy Technology Data Exchange (ETDEWEB)

    Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA; Instituto de Materiales de Madrid, C.S.I.C., Cantoblanco, 28049 Madrid, Spain; Instituto de Quimica-Fisica" Rocasolano" C.S.I.C., 28006 Madrid, Spain; Mahasarakham University, Mahasarakham 44150, Thailand; CASTI, CNR-INFM Regional Laboratory, L' Aquila 67100, Italy; SUNY Upstate Medical University, Syracuse, NY 13210, USA; Endrino, Jose; Endrino, J. L.; Marco, J. F.; Poolcharuansin, P.; Phani, A.R.; Allen, M.; Albella, J. M.; Anders, A.

    2007-12-28

    A dielectric barrier discharge (DBD) technique has been employed to produce uniform atmospheric plasmas of He and N2 gas mixtures in open air in order to functionalize the surface of filtered-arc deposited hydrogen-free diamond-like carbon (DLC) films. XPS measurements were carried out on both untreated and He/N2 DBD plasma treated DLC surfaces. Chemical states of the C 1s and N 1s peaks were collected and used to characterize the surface bonds. Contact angle measurements were also used to record the short- and long-term variations in wettability of treated and untreated DLC. In addition, cell viability tests were performed to determine the influence of various He/N2 atmospheric plasma treatments on the attachment of osteoblast MC3T3 cells. Current evidence shows the feasibility of atmospheric plasmas in producing long-lasting variations in the surface bonding and surface energy of hydrogen-free DLC and consequently the potential for this technique in the functionalization of DLC coated devices.

  10. Kinetic study on non-thermal volumetric plasma decay in the early afterglow of air discharge generated by a short pulse microwave or laser

    Science.gov (United States)

    Yang, Wei; Zhou, Qianhong; Dong, Zhiwei

    2016-08-01

    This paper reports a kinetic study on non-thermal plasma decay in the early afterglow of air discharge generated by short pulse microwave or laser. A global self-consistent model is based on the particle balance of complex plasma chemistry, electron energy equation, and gas thermal balance equation. Electron-ion Coulomb collision is included in the steady state Boltzmann equation solver to accurately describe the electron mobility and other transport coefficients. The model is used to simulate the afterglow of microsecond to nanosecond pulse microwave discharge in N2, O2, and air, as well as femtosecond laser filament discharge in dry and humid air. The simulated results for electron density decay are in quantitative agreement with the available measured ones. The evolution of plasma decay under an external electric field is also investigated, and the effect of gas heating is considered. The underlying mechanism of plasma density decay is unveiled through the above kinetic modeling.

  11. Absorption of laser radiation by femtosecond laser-induced plasma of air and its emission characteristics

    Science.gov (United States)

    Ilyin, A. A.; Golik, S. S.; Shmirko, K. A.

    2015-11-01

    The energy absorbed by femtosecond laser plasma has nonlinear dependence on incident laser energy. The threshold power for plasma formation is 5.2 GW. Emission of nitrogen molecule, nitrogen molecule ion, atomic oxygen (unresolved triplet O I 777 nm) and nitrogen (triplet N I 742.4, 744.3 and 746.8 nm) lines is detected. Molecular emission consists of second positive and firs negative systems of nitrogen. Time-resolved spectroscopy of plasmas shows short molecular line emission (up to 1 ns) and long atomic line emission (up to 150 ns).

  12. Plasma Kinetics in the Ethanol/Water/Air Mixture in "Tornado" Type Electrical Discharge

    CERN Document Server

    Levko, D; Chernyak, V; Olszewski, S; Nedybaliuk, O

    2011-01-01

    This paper presents the results of a theoretical and experimental study of plasma-assisted reforming of ethanol into molecular hydrogen in a new modification of the "tornado" type electrical discharge. Numerical modeling clarifies the nature of the non-thermal conversion and explains the kinetic mechanism of nonequilibrium plasma-chemical transformations in the gas-liquid system and the evolution of hydrogen during the reforming as a function of discharge parameters and ethanol-to-water ratio in the mixture. We also propose a scheme of chemical reactions for plasma kinetics description. It is shown that some characteristics of the investigated reactor are at least not inferior to characteristics of other plasma chemical reactors.

  13. Properties of Laser Produced TMAE Plasma Admixed with Air Constituents, Nitrogen and Noble Gases

    Science.gov (United States)

    Ding, Guowen; Scharer, John; Kelly, Kurt

    1999-10-01

    A high initial density (> 10^13 cm-3) and a large volume (hundreds of cm^3) plasma is created by a 193 nm laser ionization of an organic molecule, tetrakis(dimethyl-amino)ethylene(TMAE). The properties of this plasma mixed with nitrogen and noble gases are studied. Fast probe measurements which include a detailed considerations of probe structure, probe surface cleaning, shielding, probe perturbation, frequency response, temporal and spatial resolutions, dummy probe corrections and noise analysis will be described. Electron densities obtained by this method are independent on the ion species mixture. A plasma emission diagnostic is used to estimate plasma densities for the higher admixture pressures. Electron density and temperature vs. time for various TMAE, nitrogen and noble gas pressures and laser power will be presented. The role of super-excited and metastable states in the decay process will also be discussed.

  14. Efficient production of live offspring from mouse oocytes vitrified with a novel cryoprotective agent, carboxylated ε-poly-L-lysine.

    Directory of Open Access Journals (Sweden)

    Hitomi Watanabe

    Full Text Available In cryopreservation of mammalian germ cells, unfertilized oocytes are one of the most available stages because these cryopreserved oocytes can be used for assisted reproductive technologies, including in vitro fertilization (IVF and intracytoplasmic sperm injection. However, it has been generally reported that the fertility and developmental ability of the oocytes are reduced by cryopreservation. Therefore further improvement will be required. Very recently, a new cryoprotective agent (CPA, called as carboxylated ε-poly-L-lysine (COOH-PLL, has been developed to reduce physical and physiological damage by cryopreservation in mammalian stem cells. However, it is unclear the effect of COOH-PLL on fertility and developmental ability of vitrified oocytes. In this study, we used COOH-PLL as a CPA with ethylene glycol (EG for vitrification of mouse oocytes. Cumulus-oocyte complexes (COCs were collected from ICR mice and then vitrified with Cryotop using different concentration of COOH-PLL and EG. A combined treatment with COOH-PLL and EG showed high survival rate (more than 90% of vitrified-warmed COCs after in vitro fertilization. In addition, the fertility and developmental ability of COCs vitrified with E20P10 [EG 20% (v/v and COOH-PLL 10% (w/v] or E15P15 group (EG 15% and COOH-PLL 15% were significantly higher than those with E10P20 (EG10% and COOH-PLL 20% or P30 group (PLL30%. The vitrified COCs in E20P10 group developed to term at a high success rate (46.2% and it was significantly higher than that in control (E30 group (34.8%. Our present study demonstrated for the first time that COOH-PLL is effective for vitrification of mouse oocytes.

  15. The Effect of Media Supplementation with Angiotensin on Developmental Competence of Ovine Embryos Derived from Vitrified-warmed Oocytes

    Science.gov (United States)

    Naderi, Mohammad Mehdi; Borjian Boroujeni, Sara; Sarvari, Ali; Heidari, Banafsheh; Akhondi, Mohammad Mehdi; Zarnani, Amir-Hassan; Shirazi, Abolfazl

    2016-01-01

    Background: This study was aimed to assess the effects of angiotensin II (Ang II) supplementation to the In Vitro Maturation (IVM) and In Vitro Culture (IVC) media of vitrified-warmed ovine oocytes on their developmental competence and expression of Na+/K+/ATPase in resulting embryos. Methods: The slaughterhouse-derived immature oocytes (n=1069) were randomly distributed into four experimental groups: groups I and II) IVM/IVF and IVC of fresh and vitrified oocytes without angiotensin supplementation (Control-Fresh and Control-Vit groups, respectively); group III) IVM of vitrified oocytes in the presence of Ang II followed by IVF/IVC (Vit-IVM group); and group IV) IVM/IVF of vitrified oocytes followed by IVC wherein the embryos were exposed to Ang II on day 4 of IVC (Vit-D4 group). The embryos were immunostained with primary antibodies against Na+/K+/ATPase α1 and β1 subunits. Results: In Vit-IVM and Vit-D4 groups, the rates of expanded and total blastocysts on day 7 as well as the proportion of blastocysts on day 8 were increased. The expression of Na+/K+/ATPase α1 and β1 subunits were positively influenced by the addition of Ang II on day 4 (Vit-D4 group). Conclusion: The addition of Ang II to the IVM and IVC media could improve blastocysts formation in vitrified sheep oocytes. This improvement might be related to the greater expression of Na+/K+/ATPase α1 and β1 subunits when Ang II was added during IVC. PMID:27563427

  16. Mixed Wastes Vitrification by Transferred Plasma

    Institute of Scientific and Technical Information of China (English)

    J.TAPIA-FABELA; G.ZlSSIS; M.PACHECO-PACHECO; J.PACHECO-SOTELO; C.TORRES-REYES; R.VALDIVIA-BARRIENTOS; J.BENITEZ-READ; R.LOPEZ-CALLEJAS; F.RAMOS-FLORES; S.BOSHLE

    2007-01-01

    Thermal plasma technology provides a stable and long term treatment of mixed wastes through vitrification processes.In this work,a transferred plasma system was realized to vitrify mixed wastes,taking advantage of its high power density,enthalpy and chemical reactivity as well as its rapid quenching and high operation temperatures.To characterize the plasma discharge,a temperature diagnostic is realized by means of optical emission spectroscopy (OES).To typify the morphological structure of the wastes samples,scanning electron microscopy (SEM),and X-ray diffraction (XRD) techniques were applied before and after the plasma treatment.

  17. Two-photon absorption laser induced fluorescence measurement of atomic oxygen density in an air atmospheric pressure plasma jet

    Science.gov (United States)

    Conway, Jim; Gogna, Gurusharan; Daniels, Stephen

    2016-09-01

    Two-photon Absorption Laser Induced Fluorescence (TALIF) is used to measure atomic oxygen number density [O] in an air Atmospheric Pressure Plasma Jet (APPJ). A novel technique based on photolysis of O2 is used to calibrate the TALIF system ensuring the same species (O) is probed during calibration and measurement. As a result, laser intensity can be increased outside the TALIF quadratic laser power region without affecting calibration reliability as any high intensity saturation effects will be identical for calibration and experiment. Higher laser intensity gives stronger TALIF signals helping overcome weak TALIF signals often experienced at atmospheric pressure due to collisional quenching. O2 photo-dissociation and two-photon excitation of the resulting [O] are both achieved within the same laser pulse. The photolysis [O] is spatially non-uniform and time varying. To allow valid comparison with [O] in a plasma, spatial and temporal correction factors are required. Knowledge of the laser pulse intensity I0(t), and wavelength allows correction factors to be found using a rate equation model. The air flow into the jet was fixed and the RF power coupled into the system varied. The resulting [O] was found to increase with RF power.

  18. Factors Analysis of Spontaneous Abortion after Thawed-vitrified Blastocysts Transfer

    Institute of Scientific and Technical Information of China (English)

    Dong YANG; Zheng-yi SUN; Cheng-yan DENG; Qi YU; Fang-fang HE

    2008-01-01

    Objective To investigate the factors resulting in spontaneous abortion after transferring frozen-thawing blastocysts. Methods A total of 108 cases transferring vitrified blastocysts were divided into two groups: abortion group (n =20) and ongoing group (n=88). Cytogenetic analysis of apoblemas was performed in 12 cases of the abortion.Results The overall spontaneous abortion rate was 18.50%(20/108) and the early spontaneous rate was 16.67%(18/108). ,4 significant difference in maternal age was observed (abortion group: 33.3±4.0 years, ongoing group: 31.0±3.6 years, P=0.02). No difference in other parameters was found. Cytogenetic analysis of apoblemas was obtained for 12 cases, and 2 specimens were contaminated. Seven of ten patients had abnormal karyotypes. Conclusion The underlying cause of spontaneous abortion after transferring frozen thawing blastocysts appears to be abnormal karyotypes.Advancing maternal age seems to increase the risk of spontaneous abortion.

  19. Research of partition function on optical properties and temperature diagnosis of air plasma

    Science.gov (United States)

    Qiu, Dechuan; Gao, Guoqiang; Wei, Wenfu; Hu, Haixing; Li, Chunmao; Wu, Guangning

    2017-08-01

    The relationship between partition function, particle density, refractive index, and temperature for atmospheric plasma is calculated based on thermodynamics and chemical equilibrium. Taking into account the contribution of hydrogen-like levels to the atomic partition function, a compact method to calculate the atomic partition function is first used with the Eindhoven model to deduce the plasma's refractive index. Results calculated by the new approach and two other traditional simplified methods are compared and analyzed. For a better understanding on the temperature measurement accuracy deduced by different partition function disposal approaches, moiré deflectometry is employed as the experimental scheme to acquire the refractive index-position curve. Finally, applicability of different partition function disposal approaches are discussed, and results indicate that the optical properties deduced in this paper are well suited for the refractive index-based plasma diagnosis.

  20. Fabry-Perot spectroscopy for kinetic temperature and velocity measurements of a high enthalpy air plasma flow

    Science.gov (United States)

    Zander, Fabian; Löhle, Stefan; Hermann, Tobias; Fulge, Hannes

    2017-08-01

    The atomic translational temperatures and velocities of a low pressure, high enthalpy air plasma are measured using Fabry-Perot spectroscopy. The measurements presented here are the first measurements using this system at this enthalpy level. The sub-picometre resolution of the unique system has allowed accurate translational temperature and velocity measurements of the atomic species in the plasma. The detection system allows the Doppler broadening of multiple atomic nitrogen and oxygen lines to be measured simultaneously. Additionally, having two optical paths, one perpendicular to the flow and one at 45 deg. allows the Doppler shift to be measured. Measurements were taken during three different plasma wind tunnel tests. Mean atomic nitrogen temperatures of 1.08+/- 0.11 × 104 K and atomic oxygen translational temperatures of 1.23+/- 0.12 ×104 K were measured. The thermal non-equilibrium determined verified earlier measurements of the same phenomena, however, the mechanism behind this has not yet been determined. The mean measured flow velocity was 3350+/- 840~m~s-1 and was consistent between the atomic species. The translational temperature and velocity contribute approximately 35% of the local enthalpy of the flow. The direct measurement of these parameters, removing previously required assumptions, increases the fidelity of the flow characterisation significantly. This allows high quality testing to be conducted in this flow field.

  1. Investigating the electron density of multi-MeV X-ray-induced air plasmas at low pressures based on electromagnetic resonant cavity analysis

    Science.gov (United States)

    Ribière, M.; d'Almeida, T.; Cessenat, O.; Maulois, M.; Pouzalgues, R.; Crabos, B.; Delbos, C.; Garrigues, A.; Azaïs, B.

    2016-12-01

    We investigate air plasmas generated by multi-MeV pulsed X-rays at pressures ranging from 10-5 to 10-1 mbar. The experimental approach used for these studies is based on measurements of resonant frequencies damping and shift for different electromagnetic modes within a cylindrical cavity. Time-integrated electron densities in X-ray-induced air plasmas are inferred from the damping rate of the measured magnetic fields and their corresponding frequency shifts. In the present study, electron densities ranging from 108 to 109 cm-3 at pressures ranging from 10-3 to 10-1 mbar have been measured. Experimental results were confronted to 3D Maxwell-Vlasov Particle-In-Cell simulations incorporating a radiation-induced electric conductivity model. The method used in this work enables determining microscopic and macroscopic physical quantities within low pressure air plasmas generated by pulsed X-ray.

  2. Teknologi Sistem Plasma Radio –Frekuensi (RF Untuk Menghilangkan Bakteri Escherichia Coli Pada Air Minum

    Directory of Open Access Journals (Sweden)

    Dean Corio

    2014-09-01

    Full Text Available Refill drinking water is a source of public drinking water in Indonesia, but the quality is not guaranteed. less optimal means of water treatment to remove pollutants in Drinking Water Refill (AMIU, especially for raw water containing total coliforms and fecal coliforms cause AMIU quality is uncontrolled. The use of radio frequency plasma technology on AMIU processing system can be used as a solution. Induced plasma system by radio frequency in water can form the active compound. The active compounds will react to microorganisms and causing microorganisms be reduced. In testing wastewater 35,000 MPN (100 %, with plasma frequency of 3,3 MHz, the bacteria can degrade to 6 % and with frequency of 3,7 MHz bacteria can degrade to 0,07 %. 23.000 MPN testing river water (100 %, with plasma frequency of 3,3 MHz setting can degrade the bacteria to 9 % and with 3,7 MHz frequency setting can degrade the bacteria to 6 %.

  3. Spectral Characteristics of Laser-Induced Graphite Plasma in Ambient Air

    Science.gov (United States)

    Wang, Jinmei; Zheng, Peichao; Liu, Hongdi; Fang, Liang

    2016-11-01

    An experimental setup of laser-induced graphite plasma was built and the spectral characteristics and properties of graphite plasma were studied. From the temporal behavior of graphite plasma, the duration of CN partials (B2 Σ+ → X2 Σ+) emission was two times longer than that of atomic carbon, and all intensities reached the maximum during the early stage from 0.2 μs to 0.8 μs. The electron temperature decreased from 11807 K to 8755 K, the vibration temperature decreased from 8973 K to 6472 K, and the rotational temperature decreased from 7288 K to 4491 K with the delay time, respectively. The effect of the laser energy was also studied, and it was found that the thresholds and spectral characteristics of CN molecular and C atomic spectroscopy presented great differences. At lower laser energies, the electron excited temperature, the electron density, the vibrational temperature and rotational temperature of CN partials increased rapidly. At higher laser energies, the increasing of electron excited temperature and electron density slow down, and the vibrational temperature and rotational temperature even trend to saturation due to plasma shielding and dissociation of CN molecules. The relationship among the three kinds of temperatures was Telec>Tvib>Trot at the same time. The electron density of the graphite plasma was in the order of 1017 cm-3 and 1018 cm-3. supported by National Natural Science Foundation of China (No. 61205149), Scientific Research Foundation for the Returned Overseas Chinese Scholars of State Education Ministry, Science Research Funds of Chongqing Municipal Education Commission (KJ1500436), Scientific and Technological Talents Training Project of Chongqing (CSTC2013kjrc-qnrc40002), Key Project of Foundation and Advanced Technology Research Project of Chongqing (CSTC2015jcyjB0358), Visiting Scholarship of State Key Laboratory of Power Transmission Equipment & System Security and New Technology (2007DA10512714409)

  4. An uniform DBD plasma excited by bipolar nanosecond pulse using wire-cylinder electrode configuration in atmospheric air.

    Science.gov (United States)

    Jiang, Peng-Chao; Wang, Wen-Chun; Zhang, Shuai; Jia, Li; Yang, De-Zheng; Tang, Kai; Liu, Zhi-Jie

    2014-03-25

    In this study, a bipolar nanosecond pulsed power supply with 15 ns rising time is employed to generate an uniform dielectric barrier discharge using the wire-cylinder electrode configuration in atmospheric air. The images, waveforms of pulse voltage and discharge current, and the optical emission spectra of the discharges are recorded. The rotational and vibrational temperatures of plasma are determined by comparing the simulated spectra with the experimental spectra. The effects of pulse peak voltage, pulse repetition rate and quartz tube diameter on the emission intensities of N2 (C(3)Πu→B(3)Πg, 0-0) and N2(+)B(2)Σu(+)→X(2)Σg(+),0-0 and the rotational and vibrational temperatures have been investigated. It is found that the uniform plasma with low gas temperature can be obtained, and the emission intensities of N2 (C(3)Πu→B(3)Πg, 0-0) and N2(+)B(2)Σu(+)→X(2)Σg(+),0-0 rise with increasing the pulse peak voltage and pulse repetition rate, while decrease as the increase of quartz tube diameter. In addition, under the condition of 28 kV pulse peak voltage, 150 Hz pulse repetition rate and 7 mm quartz tube diameter, the plasma gas temperature is determined to be 330 K. The results also indicate that the plasma gas temperature keep almost constant when increasing the pulse peak voltage and pulse repetition rate but increase with the increase of the quartz tube diameter.

  5. Application of post-discharge region of atmospheric pressure argon and air plasma jet in the contamination control of Candida albicans biofilms

    Directory of Open Access Journals (Sweden)

    Anelise Cristina Osório Cesar Doria

    Full Text Available Introduction:Candida species are responsible for about 80% of hospital fungal infections. Non-thermal plasmas operated at atmospheric pressure are increasingly used as an alternative to existing antimicrobial strategy. This work investigates the action of post-discharge region of a non-thermal atmospheric plasma jet, generated by a gliding arc reactor, on biofilms of standard strain of Candida albicans grown on polyurethane substrate. Methods Samples were divided into three groups: (i non-treated; (ii treated with argon plasma, and (iii treated with argon plus air plasma. Subsequently to plasma treatment, counting of colony-forming units (CFU/ml and cell viability tests were performed. In addition, the surface morphology of the samples was evaluated by scanning electron microscopy (SEM and optical profilometry (OP. Results Reduction in CFU/ml of 85% and 88.1% were observed in groups ii and iii, respectively. Cell viability after treatment also showed reduction of 33% in group ii and 8% in group iii, in comparison with group i (100%. The SEM images allow observation of the effect of plasma chemistry on biofilm structure, and OP images showed a reduction of its surface roughness, which suggests a possible loss of biofilm mass. Conclusion The treatment in post-discharge region and the chemistries of plasma jet tested in this work were effective in controlling Candida albicans biofilm contamination. Finally, it was evidenced that argon plus air plasma was the most efficient to reduce cell viability.

  6. Ambient air particle transport into the effluent of a cold atmospheric-pressure argon plasma jet investigated by molecular beam mass spectrometry

    Science.gov (United States)

    Dünnbier, M.; Schmidt-Bleker, A.; Winter, J.; Wolfram, M.; Hippler, R.; Weltmann, K.-D.; Reuter, S.

    2013-10-01

    Ambient air species, which are transported into the active effluent of an atmospheric-pressure plasma jet result in highly reactive oxygen and nitrogen species (RONS). Especially for the envisaged application field of plasma medicine, these RONS are responsible for strong biological responses. In this work, the effect of ambient air transport into the effluent of an atmospheric-pressure plasma argon jet on the on-axis densities of nitrogen, oxygen and argon was investigated by means of absolutely calibrated molecular beam mass spectrometry (MBMS). According to biomedical experiments a (bottomless) Petri dish was installed in front of the MBMS. In the following, the near flow field is referring to the region close to the nozzle exit and the far flow field is referring to the region beyond that. The absolute on-axis densities were obtained by three different methods, for the near flow field with VUV-absorption technique, for the far flow field with the MBMS and the total flow field was calculated with a computational fluid dynamics (CFD) simulation. The results of the ambient air particle densities of all independent methods were compared and showed an excellent agreement. Therefore the transport processes of ambient air species can be measured for the whole effluent of an atmospheric-pressure plasma jet. Additionally, with the validation of the simulation it is possible in future to calculate the ambient species transport for various gas fluxes in the same turbulent flow regime. Comparing the on-axis densities obtained with an ignited and with a non-ignited plasma jet shows that for the investigated parameters, the main influence on the ambient air species transport is due to the increased temperature in the case when the jet is switched on. Moreover, the presence of positive ions (e.g. ArN_{2}^{+} ) formed due to the interaction of plasma-produced particles and ambient air species, which are transported into the effluent, is shown.

  7. Characteristics of surface-wave plasma with air-simulated N{sub 2}-O{sub 2} gas mixture for low-temperature sterilization

    Energy Technology Data Exchange (ETDEWEB)

    Xu, L [Graduate School of Electronic Science and Technology, Shizuoka University, 3-5-1 Johoku, Hamamatsu 432-8011 (Japan); Nonaka, H [Graduate School of Science and Technology, Shizuoka University, 3-5-1 Johoku, Hamamatsu 432-8011 (Japan); Zhou, H Y [Graduate School of Science and Technology, Shizuoka University, 3-5-1 Johoku, Hamamatsu 432-8011 (Japan); Ogino, A [Graduate School of Science and Technology, Shizuoka University, 3-5-1 Johoku, Hamamatsu 432-8011 (Japan); Nagata, T [Department of Microbiology and Immunology, Hamamatsu University School of Medicine, 1-20-1 Handayama, Hamamatsu 431-3192 (Japan); Koide, Y [Department of Microbiology and Immunology, Hamamatsu University School of Medicine, 1-20-1 Handayama, Hamamatsu 431-3192 (Japan); Nanko, S [Nissin Inc., 10-7 Kamei-cho, Takarazuka 665-0047 (Japan); Kurawaki, I [GMA Co. Ltd., 3898-1, Asaba, Fukuroi, 437-1101 (Japan); Nagatsu, M [Graduate School of Electronic Science and Technology, Shizuoka University, 3-5-1 Johoku, Hamamatsu 432-8011 (Japan)

    2007-02-07

    Sterilization experiments using low-pressure air discharge plasma sustained by the 2.45 GHz surface-wave have been carried out. Geobacillus stearothermoplilus spores having a population of 3.0 x 10{sup 6} were sterilized for only 3 min using air-simulated N{sub 2}-O{sub 2} mixture gas discharge plasma, faster than the cases of pure O{sub 2} or pure N{sub 2} discharge plasmas. From the SEM analysis of plasma-irradiated spores and optical emission spectroscopy measurements of the plasmas, it has been found that the possible sterilization mechanisms of air-simulated plasma are the chemical etching effect due to the oxygen radicals and UV emission from the N{sub 2} molecules and NO radicals in the wavelength range 200-400 nm. Experiment suggested that UV emission in the wavelength range less than 200 nm might not be significant in the sterilization. The UV intensity at 237.0 nm originated from the NO {gamma} system (A {sup 2}{sigma}{sup +} {yields} X {sup 2}{pi}) in N{sub 2}-O{sub 2} plasma as a function of the O{sub 2} percentage added to N{sub 2}-O{sub 2} mixture gas has been investigated. It achieved its maximum value when the O{sub 2} percentage was roughly 10-20%. This result suggests that air can be used as a discharge gas for sterilization, and indeed we have confirmed a rapid sterilization with the actual air discharge at a sample temperature of less than 65 deg. C.

  8. Investigation on the effect of RF air plasma and neem leaf extract treatment on the surface modification and antimicrobial activity of cotton fabric

    Science.gov (United States)

    Vaideki, K.; Jayakumar, S.; Rajendran, R.; Thilagavathi, G.

    2008-02-01

    A thorough investigation on the antimicrobial activity of RF air plasma and azadirachtin (neem leaf extract) treated cotton fabric has been dealt with in this paper. The cotton fabric was given a RF air plasma treatment to improve its hydrophilicity. The process parameters such as electrode gap, time of exposure and RF power have been varied to study their effect in improving the hydrophilicity of the cotton fabric and they were optimized based on the static immersion test results. The neem leaf extract (azadirachtin) was applied on fabric samples to impart antimicrobial activity. The antimicrobial efficacy of the samples have been analysed and compared with the efficacy of the cotton fabric treated with the antimicrobial finish alone. The investigation reveals that the RF air plasma has modified the surface of the fabric, which in turn increased the antimicrobial activity of the fabric when treated with azadirachtin. The surface modification due to RF air plasma treatment has been analysed by comparing the FTIR spectra of the untreated and plasma treated samples. The molecular interaction between the fabric, azadirachtin and citric acid which was used as a cross linking agent to increase the durability of the antimicrobial finish has also been analysed using FTIR spectra.

  9. Investigations on the on-line determination of metals in air flows by capacitively coupled microwave plasma atomic emission spectrometry

    Science.gov (United States)

    Seelig, M.; Broekaert, J. A. C.

    2001-09-01

    Plasma optical emission spectrometry with a capacitively coupled microwave plasma (CMP) operated with air has been investigated with respect to its possibilities for real-time environmental monitoring of combustion processes. The unique feature is the possibility to operate the CMP with air as working gas, as is usually the case in exhaust gases of combustion processes. The CMP also is shown to be stable in the presence of large amounts of water and CO 2, which makes this source ideally suitable for this purpose. The detection limits obtained for the environmentally relevant elements Cd, Co, Cr, Fe, Mg, Ni and Pb show the possibility to monitor directly heavy metals in air in an on-line mode and down to the 2-160-μg m -3 level. These detection limits are generally lower than the threshold limit values of the 'Federal Law for Immission Protection' in Germany in the gaseous effluents of industrial plants. In order to investigate the influence of the water loading (32-222 g m -3) on the detection limits a comparison of results obtained with three different nebulizers (Légère nebulizer, hydraulic high-pressure nebulizer and ultrasonic nebulizer) was made, with which aerosols with different water loading are entered into the plasma. For the hydraulic high-pressure nebulizer and the ultrasonic nebulizer no desolvation unit was found to be necessary. It was shown that especially for elements with lines having high excitation energy (Cd) or for which ion lines are used (Mg II) the increase in water loading deteriorates the detection limits. The rotational temperatures ( Trot) and excitation temperatures ( Texe) in the case of different amounts of water are of the order of 3700-4900 K and 4700-7100 K, respectively. The temperatures show that changes in the geometry and temperature distribution in the case of Trot but also the values of Texe themselves are responsible for this increase in detection limits. Furthermore, different amounts of CO 2 mixed to the working gas (3

  10. Development of sheep primordial follicles encapsulated in alginate or in ovarian tissue in fresh and vitrified samples.

    Science.gov (United States)

    Sadeghnia, Samaneh; Akhondi, Mohammad Mehdi; Hossein, Ghamartaj; Mobini, Sahba; Hosseini, Laleh; Naderi, Mohammad Mehdi; Boroujeni, Sara Borjian; Sarvari, Ali; Behzadi, Bahareh; Shirazi, Abolfazl

    2016-04-01

    In vitro follicle growth is a promising strategy for female fertility preservation. This study was conducted to compare the development of ovine follicles either isolated or in the context of ovarian cortical pieces after short term (8 days) three-dimensional culture in fresh and vitrified samples. Four different experiments were conducted; I) culture of ovarian cortical pieces encapsulated in 0.5% and 1% alginate and without alginate encapsulation (CP-0.5%, CP-1% and CP, respectively), II) culture of isolated primordial and primary follicles encapsulated in 1% and 2% alginate (IF-1% and IF-2%, respectively), III) culture of fresh and vitrified-warmed cortical pieces (F-CP and Vit-CP, respectively), and IV) culture of fresh and vitrified-warmed encapsulated isolated follicles (F-IF and Vit-IF, respectively). The number of secondary follicles after culture was negatively influenced by encapsulation of ovarian cortical pieces (6.3 ± 3.3 and 10.6 ± 0.9 vs 21.5 ± 2.3 in CP-0.5% and CP-1% vs CP, respectively). The diameter of follicles in IF-2% was higher than IF-1% (54.06 ± 2 vs 41.9 ± 1.5) and no significant difference in follicular viability was observed between the two groups. The proportions of different follicular types and their viability after culture in vitrified-warmed cortical pieces were comparable with fresh ones. The viability of vitrified-warmed isolated follicles was lower than fresh counterparts. The growth rate of fresh follicles was higher than vitrified-warmed follicles after culture (47.9 ± 1 vs 44.6 ± 1). In conclusion, while encapsulation of ovarian cortical pieces decreased the follicles' development, it could better support the growth of isolated follicles. Moreover, the viability and growth rate of isolated-encapsulated follicles was decreased by vitrification.

  11. Surface modification of biphasic calcium phosphate scaffolds by non-thermal atmospheric pressure nitrogen and air plasma treatment for improving osteoblast attachment and proliferation

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Yu-Ri [Department and Research Institute of Dental Biomaterials and Bioengineering, College of Dentistry, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752 (Korea, Republic of); Research Center for Orofacial Hard Tissue Regeneration, College of Dentistry, Yonsei University, Seoul 120-752 (Korea, Republic of); Kwon, Jae-Sung [Research Center for Orofacial Hard Tissue Regeneration, College of Dentistry, Yonsei University, Seoul 120-752 (Korea, Republic of); Song, Doo-Hoon [Department and Research Institute of Dental Biomaterials and Bioengineering, College of Dentistry, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752 (Korea, Republic of); Research Center for Orofacial Hard Tissue Regeneration, College of Dentistry, Yonsei University, Seoul 120-752 (Korea, Republic of); Choi, Eun Ha [Plasma Bioscience Research Center Kwangwoon University, Seoul 139-701, 447-1 Wokgye-Dong, Nowon-Gu, Seoul (Korea, Republic of); Lee, Yong-Keun [Department and Research Institute of Dental Biomaterials and Bioengineering, College of Dentistry, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752 (Korea, Republic of); Kim, Kyoung-Nam [Department and Research Institute of Dental Biomaterials and Bioengineering, College of Dentistry, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752 (Korea, Republic of); Research Center for Orofacial Hard Tissue Regeneration, College of Dentistry, Yonsei University, Seoul 120-752 (Korea, Republic of); Kim, Kwang-Mahn, E-mail: kmkim@yuhs.ac [Department and Research Institute of Dental Biomaterials and Bioengineering, College of Dentistry, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752 (Korea, Republic of); Research Center for Orofacial Hard Tissue Regeneration, College of Dentistry, Yonsei University, Seoul 120-752 (Korea, Republic of)

    2013-11-29

    Surface modifications induced by non-thermal plasma have been used extensively in biomedical applications. The attachment and proliferation of osteoblast cells are important in bone tissue engineering using scaffolds. Hence the effect of non-thermal plasma on hydroxyapatite/β-tri-calcium phosphate (HA/β-TCP) scaffolds in terms of improving osteoblast attachment and proliferation was investigated. Experimental groups were treated with non-thermal plasma for 10 min and 20 min and a control group was not treated with non-thermal plasma. For surface chemistry analysis, X-ray photoelectron spectroscopy (XPS) analysis was carried out. The hydrophilicity was determined from contact angle measurement on the surface. Atomic force microscopy analysis (AFM) was used to test the change in surface roughness and cell attachment and proliferation were evaluated using MC3T3-E1 osteoblast cells. XPS spectra revealed a decreased amount of carbon on the surface of the plasma-treated sample. The contact angle was also decreased following plasma treatment, indicating improved hydrophilicity of plasma-treated surfaces compared to the untreated disc. A significant increase in MC3T3E-1 cell attachment and proliferation was noted on plasma-treated samples as compared to untreated specimens. The results suggest that non-thermal atmospheric pressure nitrogen and air plasma treatments provide beneficial surface characteristics on HA/β-TCP scaffolds. - Highlights: ► Non-thermal plasma increased OH- and decreased C on biphasic scaffold. ► Non-thermal plasma had no effect on surface roughness. ► Non-thermal plasma resulted in hydrophilic surface. ► Non-thermal plasma resulted in better cell attachment and proliferation. ► Non-thermal plasma treatment on biphasic scaffold is useful for tissue engineering.

  12. A novel approach to regulate cell membrane permeability for ATP and NADH formation in Saccharomyces cerevisiae induced by air cold plasma

    Science.gov (United States)

    Xiaoyu, DONG; Tingting, LIU; Yuqin, XIONG

    2017-02-01

    Air cold plasma has been used as a novel method for enhancing microbial fermentation. The aim of this work was to explore the effect of plasma on membrane permeability and the formation of ATP and NADH in Saccharomyces cerevisiae, so as to provide valuable information for large-scale application of plasma in the fermentation industry. Suspensions of S. cerevisiae cells were exposed to air cold plasma for 0, 1, 2, 3, 4 and 5 min, and then subjected to various analyses prior to fermentation (0 h) and at the 9 and 21 h stages of fermentation. Compared with non-exposed cells, cells exposed to plasma for 1 min exhibited a marked increase in cytoplasmic free Ca2+ concentration as a result of the significant increase in membrane potential prior to fermentation. At the same time, the ATP level in the cell suspension decreased by about 40%, resulting in a reduction of about 60% in NADH prior to culturing. However, the levels of ATP and NADH in the culture at the 9 and 21 h fermentation stages were different from the level at 0 h. Taken together, the results indicated that exposure of S. cerevisiae to air cold plasma could increase its cytoplasmic free Ca2+ concentration by improving the cell membrane potential, consequently leading to changes in ATP and NADH levels. Supported by National Natural Science Foundation of China (Nos. 21246012, 21306015 and 21476032).

  13. Contact-Free Inactivation of Candida albicans Biofilms by Cold Atmospheric Air Plasma

    OpenAIRE

    Maisch, Tim; Shimizu, Tetsuji; Isbary, Georg; Heinlin, Julia; Karrer, Sigrid; Klämpfl, Tobias G.; Li, Yang-Fang; Morfill, Gregor; Julia L Zimmermann

    2012-01-01

    Candida albicans is one of the main species able to form a biofilm on almost any surface, causing both skin and superficial mucosal infections. The worldwide increase in antifungal resistance has led to a decrease in the efficacy of standard therapies, prolonging treatment time and increasing health care costs. Therefore, the aim of this work was to demonstrate the applicability of atmospheric plasma at room temperature for inactivating C. albicans growing in biofilms without thermally damagi...

  14. Spectroscopic and antimicrobial studies of polystyrene films under air plasma and He-Ne laser treatment

    Indian Academy of Sciences (India)

    S M Pawde; Sanmesh S Parab

    2008-05-01

    Polystyrene (PS) films are used in packaging and biomedical applications because of their transparency and good environmental properties. The present investigation is centered on the antifungal and antibacterial activities involved in the film surface. Subsequently, microbial formations were immobilized on the modified PS films. Living microorganisms such as bacteria and yeast were used. Untreated PS films show very fast rate of growth of bacteria within few hours. The study involves developments of polymer surfaces with bacterial growth and further studies after giving antibacterial treatment such as plasma treatment. Major emphasis has been given to study the effect of various parameters which can affect the performance of the improved material. Films were prepared by two methods: plasma treatment under vacuum and under ongoing He-Ne laser source. The parameters such as (1) surface area by contact angle measurements, (2) quality of material before and after treatment by SEM and FTIR spectra and (3) material characterization by UV-vis spectra were studied. It was observed that plasma treatment of

  15. Low friction stainless steel coatings graphite doped elaborated by air plasma sprayed

    Science.gov (United States)

    Harir, A.; Ageorges, H.; Grimaud, A.; Fauchais, P.; Platon, F.

    2004-10-01

    A new process has been developed to incorporate graphite particles into a stainless steel coating during its formation. Four means have been tested to inject the graphite particles outside the plasma jet and its plume: graphite suspension, a graphite rod rubbed on the rotating sample, powder injection close to the substrate with an injector, or a specially designed guide. The last process has been shown to be the most versatile and the most easily controllable. It allows the incorporation of between 2 and 12 vol.% of graphite particles (2 15 µm) within the plasma sprayed stainless steel coatings. A volume fraction of 2% seems to give the best results with a slight decrease (6%) of the coating hardness. This volume fraction also gave the best results in dry friction on the pin-on-disk apparatus. Depending on the sliding velocity (0.1 0.5 m/s) and loads (3.7 28 N), the dry friction coefficient against a 100C6 pin is reduced by between 1.5 and 4 compared with that obtained with plasma sprayed stainless steel.

  16. Effects of Ambient Humidity on Plant Growth Enhancement by Atmospheric Air Plasma Irradiation to Plant Seeds

    Science.gov (United States)

    Sarinont, Thapanut; Amano, Takaaki; Koga, Kazunori; Shiratani, Masaharu

    2015-09-01

    Humidity is an important factor for plasma-bio applications because composition of species generated by atmospheric pressure plasmas significantly depends on the humidity. Here we have examined effects of humidity on the growth enhancement to study the mechanism. Experiments were carried out with a scalable DBD device. 10 seeds of Raphanus sativus L. were set for x = 5 mm and y = 3 mm below the electrodes. The humidity Hair was 10 - 90 %Rh. The ratio of length of plants with plasma irradiation to that of control increases from 1.2 for Hair = 10 %Rh to 2.5 for Hair = 50 %Rh. The ratio is 2.5 for Hair = 50-90 %Rh. This humidity dependence is similar to the humidity dependence of O2+-H2O,H3O*, NO2--H2Oand NO3--H2Odensities, whereas it is different from that of other species such as O3, NO, and so on. The similarity gives information on key species for the growth enhancement.

  17. Ultrasound enhanced plasma treatment of glass-fibre-reinforced polyester in atmospheric pressure air for adhesion improvement

    DEFF Research Database (Denmark)

    Kusano, Yukihiro; Singh, Shailendra Vikram; Norrman, Kion

    2011-01-01

    A glass-fibre-reinforced polyester (GFRP) plate was treated with dielectric barrier discharge (DBD) at atmospheric pressure in air for adhesion improvement. The effects of ultrasonic irradiation using a high-power gas-jet generator during the treatment were investigated. The optical emission...... damage of the GFRP plates. The polar component of the surface energy of the polyester plate was 21 mJ/m2 before the treatment, increased markedly to 52 mJ/m2 after 2-s plasma treatment without ultrasonic irradiation, and further increased slightly after longer treatments. In addition, the polar component...... of the surface energy increased due to the simultaneous ultrasonic irradiation, indicating that the adhesive property would be further improved. This result shows a good agreement with surface characterization by X-ray photoelectron spectroscopy. Time-of-flight secondary ion mass spectrometry ion images show...

  18. Development of a low-cost atmospheric non-thermal plasma jet and its characteristics in air and nitrogen

    Science.gov (United States)

    Allam, Tarek M.; Ahmed, Kamal M.; Abouelatta, Mohamed A.; Ward, Sayed A.; Lashin, Ahmed A.; Soliman, Hanaa M.

    2016-10-01

    This paper deals with the development of a low-cost atmospheric non-thermal plasma jet (ANPJ) which was designed and operated previously in our laboratory. The purpose of the developed design with a small size less than 4% of the previous volume is to obtain a more portable device which holds promise for various fields of applications. The discharge is operated separately with compressed air and nitrogen gas with flow rates varied within the range of 3-18 L/min. The plasma plume length and thickness are measured as a function of the gas flow rate and input voltage Vinput within the range of 3-18 L/min and 2-6 kV respectively. The results showed that for nitrogen gas, the maximum values of the plume length and thickness are 20 mm and 1.3 mm respectively at a flow rate of 12 L/min and Vinput = 6 kV. Results of electrical characterization at Vinput = 6 kV such as discharge voltage, discharge current, the mean consumed power and energy showed that the maximum values of these parameters are obtained at a flow rate of 12 L/min. The developed design is found to be saving up to 65.47% and 68.54% of the consumed power compared to the previous design in the case of air and N2 respectively. The new proposed configuration for the developed ANPJ offers more suitable characteristics than the earlier designs, especially for nitrogen gas.

  19. Women's age and embryo developmental speed accurately predict clinical pregnancy after single vitrified-warmed blastocyst transfer.

    Science.gov (United States)

    Kato, Keiichi; Ueno, Satoshi; Yabuuchi, Akiko; Uchiyama, Kazuo; Okuno, Takashi; Kobayashi, Tamotsu; Segawa, Tomoya; Teramoto, Shokichi

    2014-10-01

    The aim of this study was to establish a simple, objective blastocyst grading system using women's age and embryo developmental speed to predict clinical pregnancy after single vitrified-warmed blastocyst transfer. A 6-year retrospective cohort study was conducted in a private infertility centre. A total of 7341 single vitrified-armed blastocyst transfer cycles were included, divided into those carried out between 2006 and 2011 (6046 cycles) and 2012 (1295 cycles). Clinical pregnancy rate, ongoing pregnancy rate and delivery rates were stratified by women's age (149 h) as embryo developmental speed. In all the age groups, clinical pregnancy rate, ongoing pregnancy rate and delivery rates decreased as the embryo developmental speed decreased (P pregnancy rates observed in the 2006-2011 cohort. Subsequently, the novel grading score was validated in the 2012 cohort (1295 cycles), finding an excellent association. In conclusion, we established a novel blastocyst grading system using women's age and embryo developmental speed as objective parameters.

  20. Successful pregnancy following the transfer of vitrified blastocyst which developed from poor quality embryos on day 3

    Directory of Open Access Journals (Sweden)

    Xiao-jian Zhang

    2011-01-01

    Full Text Available Background: The selection of pre-embryos for transferred is based on morphological appearance. But some poor quality cleaved embryos also can be cultured to the blastocyst stage and implanted.Objective: To assess the clinical pregnancy outcomes of blastocyst transfer which developed from poor quality embryos. Materials and Methods: A total of 109 cleaved embryos with poor quality were cultured to day 5/day 6 and 27 (24.8% blastocysts were collected from the 15 cycles/patients undergoing conventional IVF. All the blastocysts were cooling with fast-freezing. Then the blastocysts were warmed for transfer. Results: All of 25 vitrified blastocysts (92.6% survived after warming and were transferred to 15 patients. Five of the women became pregnant. Conclusion: Our results suggest that vitrified human day 5/day 6 blastocyst transfer which develop from poor quality embryo at day 3 can contribute to increasing cumulative pregnancy rates in assisted reproduction

  1. Interferometric and schlieren characterization of the plasmas and shock wave dynamics during laser-triggered discharge in atmospheric air

    Science.gov (United States)

    Wei, Wenfu; Li, Xingwen; Wu, Jian; Yang, Zefeng; Jia, Shenli; Qiu, Aici

    2014-08-01

    This paper describes our efforts to reveal the underlying physics of laser-triggered discharges in atmospheric air using a Mach-Zehnder interferometer and schlieren photography. Unlike the hemispherical shock waves that are produced by laser ablation, bell-like morphologies are observed during laser-triggered discharges. Phase shifts are recovered from the interferograms at a time of 1000 ns by the 2D fast Fourier transform method, and then the values of the refractive index are deduced using the Abel inversion. An abundance of free electrons is expected near the cathode surface. The schlieren photographs visualize the formation of stagnation layers at ˜600 ns in the interaction zones of the laser- and discharge-produced plasmas. Multiple reflected waves are observed at later times with the development of shock wave propagations. Estimations using the Taylor-Sedov self-similar solution indicated that approximately 45.8% and 51.9% of the laser and electrical energies are transferred into the gas flow motions, respectively. Finally, numerical simulations were performed, which successfully reproduced the main features of the experimental observations, and provided valuable insights into the plasma and shock wave dynamics during the laser-triggered discharge.

  2. Thermal Fatigue Behavior of Air-Plasma Sprayed Thermal Barrier Coating with Bond Coat Species in Cyclic Thermal Exposure

    Directory of Open Access Journals (Sweden)

    Ungyu Paik

    2013-08-01

    Full Text Available The effects of the bond coat species on the delamination or fracture behavior in thermal barrier coatings (TBCs was investigated using the yclic thermal fatigue and thermal-shock tests. The interface microstructures of each TBC showed a good condition without cracking or delamination after flame thermal fatigue (FTF for 1429 cycles. The TBC with the bond coat prepared by the air-plasma spray (APS method showed a good condition at the interface between the top and bond coats after cyclic furnace thermal fatigue (CFTF for 1429 cycles, whereas the TBCs with the bond coats prepared by the high-velocity oxygen fuel (HVOF and low-pressure plasma spray (LPPS methods showed a partial cracking (and/or delamination and a delamination after 780 cycles, respectively. The TBCs with the bond coats prepared by the APS, HVOF and LPPS methods were fully delaminated (>50% after 159, 36, and 46 cycles, respectively, during the thermal-shock tests. The TGO thickness in the TBCs was strongly dependent on the both exposure time and temperature difference tested. The hardness values were found to be increased only after the CFTF, and the TBC with the bond coat prepared by the APS showed the highest adhesive strength before and after the FTF.

  3. Contribution of a portable air plasma torch to rapid blood coagulation as a method of preventing bleeding

    Science.gov (United States)

    Kuo, S. P.; Tarasenko, O.; Chang, J.; Popovic, S.; Chen, C. Y.; Fan, H. W.; Scott, A.; Lahiani, M.; Alusta, P.; Drake, J. D.; Nikolic, M.

    2009-11-01

    The effectiveness and mechanism of a low temperature air plasma torch in clotting blood are explored. Both blood droplets and smeared blood samples were used in the tests. The treated droplet samples reveal how blood clotting depends on the distance at which the torch operated, and for how long the droplets have been exposed to the torch. Microscopy and cell count of smeared blood samples shed light on dependencies of erythrocyte and platelet counts on torch distance and exposure time. With an increase of torch distance, the platelet count of treated blood samples increases but is less than that of the control. The flux of reactive atomic oxygen (RAO) and the degree of blood clotting decreased. With an increase of exposure time, platelet count of treated samples decreased, while the degree of clot increased. The correlation among these dependencies and published data support a blood clotting mechanism that RAO as well as other likely reactive oxygen species generated by the plasma torch activate erythrocyte-platelets interactions and induces blood coagulation.

  4. Cryopreservation of Equine Embryos and First Report of a Native Colombian Breed Born by Transfer of an Equine Vitrified Embryo

    Directory of Open Access Journals (Sweden)

    Nadya Nathalie Martínez

    2014-06-01

    Full Text Available The aim of this paper is to report on the success of a cryopreservation procedure of equine embryos to achieve a viable pregnancy. Equine embryos were collected on day 6-6.5 (<300 μm, n = 24 and subjected to two cryopreservation techniques: group 1 (n = 12, vitrified, exposing them to a VS1 (Gli [1.4 M] 5 min, VS2 (Gli [1.4 M] + EG [3.6 M] and VS3 (Gli [3.4M] + EG [4.6 M] 1 min solution. They were packed in 0.25 ml straws and immersed in liquid nitrogen; group 2 (n = 12, slow freezing: exposed to a freezing solution (1.8 M EG + 0.1 M sucrose for 10 minutes, packed into 0.25 ml straws, brought to the embryos freezer, exposed to a freezing curve and immersed in liquid nitrogen. Following defrosting, cryoprotectants were removed from the 24 embryos in one step; they were submerged in culture medium DMEM/F12 + 10% of fetal bovine serum (FBS and incubated under controlled atmosphere (5% CO2, 5% N2, 90% O2 for 48 h. Embryonic development was evaluated in 75% of the vitrified embryos (n = 4; 20% of the embryos were subjected to slow freezing (n = 1. No significant difference was observed in the groups regarding embryonic development, but a greater survival tendency on the vitrified embryos was noted. Also, one of these vitrified embryos was transferred to a receiver, achieving a viable pregnancy and the birth of a living foal.

  5. Atomic oxygen in a cold argon plasma jet: TALIF spectroscopy in ambient air with modelling and measurements of ambient species diffusion

    Science.gov (United States)

    Reuter, S.; Winter, J.; Schmidt-Bleker, A.; Schroeder, D.; Lange, H.; Knake, N.; Schulz-von der Gathen, V.; Weltmann, K.-D.

    2012-04-01

    By investigating the atomic oxygen density in its effluent, two-photon absorption laser-induced fluorescence (TALIF) spectroscopy measurements are for the first time performed in a cold argon/oxygen atmospheric pressure plasma jet. The measurements are carried out in ambient air and quenching by inflowing air species is considered. We propose a novel absorption technique in the VUV spectral range, where emission originating from within the discharge is used as light source to determine the inflow of atmospheric oxygen into the effluent. Furthermore, we propose a modelling solution for the on-axis density of inflowing ambient air based on the stationary convection-diffusion equation.

  6. Novel atmospheric pressure plasma device releasing atomic hydrogen: reduction of microbial-contaminants and OH radicals in the air

    Science.gov (United States)

    Nojima, Hideo; Park, Rae-Eun; Kwon, Jun-Hyoun; Suh, Inseon; Jeon, Junsang; Ha, Eunju; On, Hyeon-Ki; Kim, Hye-Ryung; Choi, Kyoung Hui; Lee, Kwang-Hee; Seong, Baik-Lin; Jung, Hoon; Kang, Shin Jung; Namba, Shinichi; Takiyama, Ken

    2007-01-01

    A novel atmospheric pressure plasma device releasing atomic hydrogen has been developed. This device has specific properties such as (1) deactivation of airborne microbial-contaminants, (2) neutralization of indoor OH radicals and (3) being harmless to the human body. It consists of a ceramic plate as a positive ion generation electrode and a needle-shaped electrode as an electron emission electrode. Release of atomic hydrogen from the device has been investigated by the spectroscopic method. Optical emission of atomic hydrogen probably due to recombination of positive ions, H+(H2O)n, generated from the ceramic plate electrode and electrons emitted from the needle-shaped electrode have been clearly observed in the He gas (including water vapour) environment. The efficacy of the device to reduce airborne concentrations of influenza virus, bacteria, mould fungi and allergens has been evaluated. 99.6% of airborne influenza virus has been deactivated with the operation of the device compared with the control test in a 1 m3 chamber after 60 min. The neutralization of the OH radical has been investigated by spectroscopic and biological methods. A remarkable reduction of the OH radical in the air by operation of the device has been observed by laser-induced fluorescence spectroscopy. The cell protection effects of the device against OH radicals in the air have been observed. Furthermore, the side effects have been checked by animal experiments. The harmlessness of the device has been confirmed.

  7. N Vibrational Temperatures and OH Number Density Measurements in a NS Pulse Discharge Hydrogen-Air Plasmas

    Science.gov (United States)

    Hung, Yichen; Winters, Caroline; Jans, Elijah R.; Frederickson, Kraig; Adamovich, Igor V.

    2017-06-01

    This work presents time-resolved measurements of nitrogen vibrational temperature, translational-rotational temperature, and absolute OH number density in lean hydrogen-air mixtures excited in a diffuse filament nanosecond pulse discharge, at a pressure of 100 Torr and high specific energy loading. The main objective of these measurements is to study a possible effect of nitrogen vibrational excitation on low-temperature kinetics of HO2 and OH radicals. N2 vibrational temperature and gas temperature in the discharge and the afterglow are measured by ns broadband Coherent Anti-Stokes Scattering (CARS). Hydroxyl radical number density is measured by Laser Induced Fluorescence (LIF) calibrated by Rayleigh scattering. The results show that the discharge generates strong vibrational nonequilibrium in air and H2-air mixtures for delay times after the discharge pulse of up to 1 ms, with peak vibrational temperature of Tv ≈ 2000 K at T ≈ 500 K. Nitrogen vibrational temperature peaks ≈ 200 μs after the discharge pulse, before decreasing due to vibrational-translational relaxation by O atoms (on the time scale of a few hundred μs) and diffusion (on ms time scale). OH number density increases gradually after the discharge pulse, peaking at t 100-300 μs and decaying on a longer time scale, until t 1 ms. Both OH rise time and decay time decrease as H2 fraction in the mixture is increased from 1% to 5%. OH number density in a 1% H2-air mixture peaks at approximately the same time as vibrational temperature in air, suggesting that OH kinetics may be affected by N2 vibrational excitation. However, preliminary kinetic modeling calculations demonstrate that OH number density overshoot is controlled by known reactions of H and O radicals generated in the plasma, rather than by dissociation by HO2 radical in collisions with vibrationally excited N2 molecules, as has been suggested earlier. Additional measurements at higher specific energy loadings and kinetic modeling

  8. Mitigation of electron attachment to oxygen in high pressure air plasmas by vibrational excitation

    Science.gov (United States)

    Frederickson, K.; Lee, W.; Palm, P.; Adamovich, I. V.; Rich, J. W.; Lempert, W. R.

    2007-05-01

    A series of time resolved microwave attenuation measurements are performed of the electron number density of an electron beam generated, CO laser excited nonequilibrium O2/N2 plasma. Resonant absorption of infrared radiation from the CO laser produces the nonequilibrium state, in which the heavy species vibrational modes are disproportionately excited, compared to the rotational and translational modes (Tvib≈2000-3000K vs TR /T≈300K). It is shown that this results in an increase in the plasma free electron lifetime by two orders of magnitude compared to the unexcited cold gas, an effect which is ascribed to complete mitigation of rapid three-body electron attachment to molecular oxygen. A series of heavy species filtered pure rotational Raman scattering measurements are also presented, which exhibit minimal temperature change (+50K), indicating that the observed lifetime increase cannot be due to heavy-species thermal effects. Finally, computational modeling results infer an increase in the rate of O2- detachment by four to five orders of magnitude, compared to the equilibrium value.

  9. Oocyte maturation and expression pattern of follicular genes during in-vitro culture of vitrified mouse pre-antral follicles.

    Science.gov (United States)

    Jamalzaei, Parisa; Valojerdi, Mojtaba Rezazadeh; Ebrahimi, Bita; Farrokhi, Ali

    2016-01-01

    Our aim was to evaluate the oocyte maturation rate and follicular genes expression pattern during in-vitro culture of vitrified mouse pre-antral follicles. Middle sized pre-antral follicles were isolated mechanically from the ovaries of pre-pubertal mice and distributed in vitrification and control groups. In the vitrification group, follicles were washed in equilibration and vitrification solutions and then were immersed in liquid nitrogen after loading on cryotop tips. After warming in descending concentrations of sucrose solutions, fresh and vitrified-warmed follicles were cultured for 13 days. Follicles survival rate and follicular genes expression were assessed during in vitro culture. Finally, at the end of the culture period oocytes maturation rate were compared in both groups. In the vitrification group, follicles survival rate was lower significantly comparing to the control group (P culture period, expression of some genes such as Gdf9, Bmp15, Tgfβ1 and BmprII were higher in the vitrification group (P culture period expression pattern of all follicular genes were similar in both groups. In conclusion, survival rate of cryotop vitrified pre-antral follicles reduced during culture period while oocytes maturation and follicular genes expression did not show any noticeable alteration.

  10. In Vitro Maturation, Fertilization and Embryo Culture of Oocytes Obtained from Vitrified Auto-Transplanted Mouse Ovary

    Directory of Open Access Journals (Sweden)

    Arash Behbahanian

    2013-01-01

    Full Text Available Background: The purpose of this study was to investigate the in vitro survival and developmentalpotential of oocytes obtained from vitrified mouse ovaries transplanted to a heterotopic site.Materials and Methods: In this experimental study, two-week-old mice were unilaterallyovariectomized after anesthesia. The ovaries were vitrified by cryotop. After two weeks, the ovarieswere thawed and autotransplanted to the gluteus muscle tissue. Three weeks later the mice werekilled, after which we removed and dissected the transplanted and opposite right ovaries. Cumulusoocyte complexes (COCs and denuded oocytes were evaluated for in vitro maturation (IVM, invitro fertilization (IVF and in vitro development (IVD. The control group consisted of sevenweek-old age-matched mice ovaries.Results: All vitrified-transplanted (Vit-trans ovaries contained some oocytes that survived.Following IVM, IVF and IVD, there were 41.7% out of 12 cultured zygotes that reached the 8-cellstage.Conclusion: Our experiment supports the progressive role of long-term graft survival after wholeovariancryopreservation by vitrification and subsequent heterotopic transplantation. It is possible torecover viable follicles and oocytes that have the ability to develop in vitro.

  11. Production of fertile zebrafish (Danio rerio) possessing germ cells (gametes) originated from primordial germ cells recovered from vitrified embryos.

    Science.gov (United States)

    Higaki, Shogo; Eto, Yoshiki; Kawakami, Yutaka; Yamaha, Etsuro; Kagawa, Noriko; Kuwayama, Masashige; Nagano, Masashi; Katagiri, Seiji; Takahashi, Yoshiyuki

    2010-04-01

    This study aimed to produce fertile zebrafish (Danio rerio) possessing germ cells (gametes) that originated from cryopreserved primordial germ cells (PGCs). First, to improve the vitrification procedure of PGCs in segmentation stage embryos, dechorionated yolk-intact and yolk-removed embryos, the PGCs of which were labeled with green fluorescent protein, were cooled rapidly after serial exposures to equilibration solution (ES) and vitrification solution (VS), which contained ethylene glycol, DMSO, and sucrose. Yolk removal well prevented ice formation in the embryos during cooling and improved the viability of cryopreserved PGCs. The maximum recovery rate of live PGCs in the yolk-removed embryos vitrified after optimum exposure to ES and VS was estimated to be about 90%, and about 50% of the live PGCs showed pseudopodial movement. Next, to elucidate the ability of cryopreserved PGCs to differentiate into functional gametes, PGCs recovered from the yolk-removed embryos (striped-type) that were vitrified under the optimum exposure to ES and VS were transplanted individually into 218 sterilized recipient blastulae (golden-type). Two days after the transplantation, 7.5% (14/187) of morphologically normal embryos had PGC(s) in the genital ridges. Six (5 males and 1 female) of the 14 recipient embryos developed into mature fish and generated progeny with characteristics inherited from PGC donors. In conclusion, we demonstrated the successful cryopreservation of PGCs by vitrification of yolk-removed embryos and the production of fertile zebrafish possessing germ cells that originated from the PGCs in vitrified embryos.

  12. Cellular attachment and differentiation on titania nanotubes exposed to air- or nitrogen-based non-thermal atmospheric pressure plasma.

    Science.gov (United States)

    Seo, Hye Yeon; Kwon, Jae-Sung; Choi, Yu-Ri; Kim, Kwang-Mahn; Choi, Eun Ha; Kim, Kyoung-Nam

    2014-01-01

    The surface topography and chemistry of titanium implants are important factors for successful osseointegration. However, chemical modification of an implant surface using currently available methods often results in the disruption of topographical features and the loss of beneficial effects during the shelf life of the implant. Therefore, the aim of this study was to apply the recently highlighted portable non-thermal atmospheric pressure plasma jet (NTAPPJ), elicited from one of two different gas sources (nitrogen and air), to TiO2 nanotube surfaces to further improve their osteogenic properties while preserving the topographical morphology. The surface treatment was performed before implantation to avoid age-related decay. The surface chemistry and morphology of the TiO2 nanotube surfaces before and after the NTAPPJ treatment were determined using a field-emission scanning electron microscope, a surface profiler, a contact angle goniometer, and an X-ray photoelectron spectroscope. The MC3T3-E1 cell viability, attachment and morphology were confirmed using calcein AM and ethidium homodimer-1 staining, and analysis of gene expression using rat mesenchymal stem cells was performed using a real-time reverse-transcription polymerase chain reaction. The results indicated that both portable nitrogen- and air-based NTAPPJ could be used on TiO2 nanotube surfaces easily and without topographical disruption. NTAPPJ resulted in a significant increase in the hydrophilicity of the surfaces as well as changes in the surface chemistry, which consequently increased the cell viability, attachment and differentiation compared with the control samples. The nitrogen-based NTAPPJ treatment group exhibited a higher osteogenic gene expression level than the air-based NTAPPJ treatment group due to the lower atomic percentage of carbon on the surface that resulted from treatment. It was concluded that NTAPPJ treatment of TiO2 nanotube surfaces results in an increase in cellular activity

  13. Cellular attachment and differentiation on titania nanotubes exposed to air- or nitrogen-based non-thermal atmospheric pressure plasma.

    Directory of Open Access Journals (Sweden)

    Hye Yeon Seo

    Full Text Available The surface topography and chemistry of titanium implants are important factors for successful osseointegration. However, chemical modification of an implant surface using currently available methods often results in the disruption of topographical features and the loss of beneficial effects during the shelf life of the implant. Therefore, the aim of this study was to apply the recently highlighted portable non-thermal atmospheric pressure plasma jet (NTAPPJ, elicited from one of two different gas sources (nitrogen and air, to TiO2 nanotube surfaces to further improve their osteogenic properties while preserving the topographical morphology. The surface treatment was performed before implantation to avoid age-related decay. The surface chemistry and morphology of the TiO2 nanotube surfaces before and after the NTAPPJ treatment were determined using a field-emission scanning electron microscope, a surface profiler, a contact angle goniometer, and an X-ray photoelectron spectroscope. The MC3T3-E1 cell viability, attachment and morphology were confirmed using calcein AM and ethidium homodimer-1 staining, and analysis of gene expression using rat mesenchymal stem cells was performed using a real-time reverse-transcription polymerase chain reaction. The results indicated that both portable nitrogen- and air-based NTAPPJ could be used on TiO2 nanotube surfaces easily and without topographical disruption. NTAPPJ resulted in a significant increase in the hydrophilicity of the surfaces as well as changes in the surface chemistry, which consequently increased the cell viability, attachment and differentiation compared with the control samples. The nitrogen-based NTAPPJ treatment group exhibited a higher osteogenic gene expression level than the air-based NTAPPJ treatment group due to the lower atomic percentage of carbon on the surface that resulted from treatment. It was concluded that NTAPPJ treatment of TiO2 nanotube surfaces results in an increase in

  14. Hydrophobic recovery of repeatedly plasma-treated silicone rubber .2. A comparison of the hydrophobic recovery in air, water, or liquid nitrogen

    NARCIS (Netherlands)

    Everaert, EP; VanderMei, HC; Busscher, HJ

    1996-01-01

    Surfaces of medical grade silicone rubber (Q7-4750, Dow Coming) were modified by repeated (six times) RF plasma treatments using various discharge gases: oxygen, argon, carbon dioxide, and ammonia. The treated samples were stored for a period of 3 months in ambient air, water, or liquid nitrogen. Su

  15. Study of nanosecond discharges in H2-air mixtures at atmospheric pressure for plasma assisted combustion applications

    Science.gov (United States)

    Kobayashi, Sumire; Bonaventura, Zdeněk; Tholin, Fabien; Popov, Nikolay A.; Bourdon, Anne

    2017-07-01

    This paper presents 2D simulations of nanosecond discharges between two point electrodes for four different H2-air mixtures defined by their equivalence ratios ϕ (i.e. φ =0, air, φ =0.3, lean mixture, φ =1, stoichiometric mixture and φ =1.5, rich mixture) at atmospheric pressure and at an initial temperature of 1000 K. In a first step, we have shown that the mixture composition has only a very small influence on the discharge dynamics and structure during the streamer phase and up to the formation of the plasma channel between the two point electrodes in H2-air mixtures with φ \\in [0,1.5]. However, as the plasma channel is formed slightly earlier as the equivalence ratio increases, for a given voltage pulse, the duration of the nanosecond spark phase increases as the equivalence ratio increases. As expected, we have shown that excited states of N2 (and in particular N2(A)) and radicals (and in particular O(D), O(P), H and OH) are very efficiently produced during the voltage pulse after the start of the spark phase. After the voltage pulse, and up to 100 ns, the densities of excited states of N2 and of O(D) decrease. Conversely, most of the O(P), H and OH radicals are produced after the voltage pulse due to the dissociative quenching of electronically excited N2. As for radicals, the gas temperature starts increasing after the start of the spark phase. For all studied mixtures, the density of O(P) atoms and the gas temperature reach their maxima after the end of the voltage pulse and the densities of O(P), H and OH radicals and the maximal gas temperature increase as the equivalence ratio increases. We have shown that the production of radicals is the highest on the discharge axis and the distribution of species after the voltage pulse and up to 100 ns has a larger diameter between the electrodes than close to both electrode tips. As for species, the temperature distribution presents two hot spots close to the point electrode tips. The non

  16. A Review of Iron Phosphate Glasses and Recommendations for Vitrifying Hanford Waste

    Energy Technology Data Exchange (ETDEWEB)

    Delbert E. Ray; Chandra S. Ray

    2013-11-01

    This report contains a comprehensive review of the research conducted, world-wide, on iron phosphate glass over the past ~30 years. Special attention is devoted to those iron phosphate glass compositions which have been formulated for the purpose of vitrifying numerous types of nuclear waste, with special emphasis on the wastes stored in the underground tanks at Hanford WA. Data for the structural, chemical, and physical properties of iron phosphate waste forms are reviewed for the purpose of understanding their (a) outstanding chemical durability which meets all current DOE requirements, (b) high waste loadings which can exceed 40 wt% (up to 75 wt%) for several Hanford wastes, (c) low melting temperatures, can be as low as 900°C for certain wastes, and (d) high tolerance for “problem” waste components such as sulfates, halides, and heavy metals (chromium, actinides, noble metals, etc.). Several recommendations are given for actions that are necessary to smoothly integrate iron phosphate glass technology into the present waste treatment plans and vitrification facilities at Hanford.

  17. Large Thermal Conductivity Differences between the Crystalline and Vitrified States of DMSO with Applications to Cryopreservation

    Science.gov (United States)

    Ehrlich, Lili E.; Feig, Justin S. G.; Schiffres, Scott N.; Malen, Jonathan A.; Rabin, Yoed

    2015-01-01

    Thermal conductivity of dimethyl-sulfoxide (DMSO) solution is measured in this study using a transient hot wire technique, where DMSO is a key ingredient in many cryoprotective agent (CPA) cocktails. Characterization of thermal properties of cryoprotective agents is essential to the analysis of cryopreservation processes, either when evaluating experimental data or for the design of new protocols. Also presented are reference measurements of thermal conductivity for pure water ice and glycerol. The thermal conductivity measurement setup is integrated into the experimentation stage of a scanning cryomacroscope apparatus, which facilitates the correlation of measured data with visualization of physical events. Thermal conductivity measurements were conducted for a DMSO concentration range of 2M and 10M, in a temperature range of -180°C and 25°C. Vitrified samples showed decreased thermal conductivity with decreasing temperature, while crystalline samples showed increased thermal conductivity with decreasing temperature. These different behaviors result in up to a tenfold difference in thermal conductivity at -180°C. Such dramatic differences can drastically impact heat transfer during cryopreservation and their quantification is therefore critical to cryobiology. PMID:25985058

  18. Large Thermal Conductivity Differences between the Crystalline and Vitrified States of DMSO with Applications to Cryopreservation.

    Science.gov (United States)

    Ehrlich, Lili E; Feig, Justin S G; Schiffres, Scott N; Malen, Jonathan A; Rabin, Yoed

    2015-01-01

    Thermal conductivity of dimethyl-sulfoxide (DMSO) solution is measured in this study using a transient hot wire technique, where DMSO is a key ingredient in many cryoprotective agent (CPA) cocktails. Characterization of thermal properties of cryoprotective agents is essential to the analysis of cryopreservation processes, either when evaluating experimental data or for the design of new protocols. Also presented are reference measurements of thermal conductivity for pure water ice and glycerol. The thermal conductivity measurement setup is integrated into the experimentation stage of a scanning cryomacroscope apparatus, which facilitates the correlation of measured data with visualization of physical events. Thermal conductivity measurements were conducted for a DMSO concentration range of 2M and 10M, in a temperature range of -180°C and 25°C. Vitrified samples showed decreased thermal conductivity with decreasing temperature, while crystalline samples showed increased thermal conductivity with decreasing temperature. These different behaviors result in up to a tenfold difference in thermal conductivity at -180°C. Such dramatic differences can drastically impact heat transfer during cryopreservation and their quantification is therefore critical to cryobiology.

  19. Large Thermal Conductivity Differences between the Crystalline and Vitrified States of DMSO with Applications to Cryopreservation.

    Directory of Open Access Journals (Sweden)

    Lili E Ehrlich

    Full Text Available Thermal conductivity of dimethyl-sulfoxide (DMSO solution is measured in this study using a transient hot wire technique, where DMSO is a key ingredient in many cryoprotective agent (CPA cocktails. Characterization of thermal properties of cryoprotective agents is essential to the analysis of cryopreservation processes, either when evaluating experimental data or for the design of new protocols. Also presented are reference measurements of thermal conductivity for pure water ice and glycerol. The thermal conductivity measurement setup is integrated into the experimentation stage of a scanning cryomacroscope apparatus, which facilitates the correlation of measured data with visualization of physical events. Thermal conductivity measurements were conducted for a DMSO concentration range of 2M and 10M, in a temperature range of -180°C and 25°C. Vitrified samples showed decreased thermal conductivity with decreasing temperature, while crystalline samples showed increased thermal conductivity with decreasing temperature. These different behaviors result in up to a tenfold difference in thermal conductivity at -180°C. Such dramatic differences can drastically impact heat transfer during cryopreservation and their quantification is therefore critical to cryobiology.

  20. Ensuring Longevity: Ancient Glasses Help Predict Durability of Vitrified Nuclear Waste

    Energy Technology Data Exchange (ETDEWEB)

    Weaver, Jamie L.; McCloy, John S.; Ryan, Joseph V.; Kruger, Albert A.

    2016-05-01

    How does glass alter with time? For the last hundred years this has been an important question to the fields of object conservation and archeology to ensure the preservation of glass artifacts. This same question is part of the development and assessment of durable glass waste forms for the immobilization of nuclear wastes. Researchers have developed experiments ranging from simple to highly sophisticated to answer this question, and, as a result, have gained significant insight into the mechanisms that drive glass alteration. However, the gathered data have been predominately applicable to only short-term alteration times, i.e. over the course of decades. What has remained elusive is the long-term mechanisms of glass alteration[1]. These mechanisms are of particular interest to the international nuclear waste glass community as they strive to ensure that vitrified products will be durable for thousands to tens of thousands of years. For the last thirty years this community has been working to fill this research gap by partnering with archeologists, museum curators, and geologists to identify hundred to million-year old glass analogues that have altered in environments representative of those expected at potential nuclear waste disposal sites. The process of identifying a waste glass relevant analogue is challenging as it requires scientists to relate data collected from short-term laboratory experiments to observations made from long-term analogues and extensive geochemical modeling.

  1. Phosphorus detection in vitrified bacteria by cryo-STEM annular dark-field analysis.

    Science.gov (United States)

    Wolf, Sharon Grayer; Rez, Peter; Elbaum, Michael

    2015-11-01

    Bacterial cells often contain dense granules. Among these, polyphosphate bodies (PPBs) store inorganic phosphate for a variety of essential functions. Identification of PPBs has until now been accomplished by analytical methods that required drying or chemically fixing the cells. These methods entail large electron doses that are incompatible with low-dose imaging of cryogenic specimens. We show here that Scanning Transmission Electron Microscopy (STEM) of fully hydrated, intact, vitrified bacteria provides a simple means for mapping of phosphorus-containing dense granules based on quantitative sensitivity of the electron scattering to atomic number. A coarse resolution of the scattering angles distinguishes phosphorus from the abundant lighter atoms: carbon, nitrogen and oxygen. The theoretical basis is similar to Z contrast of materials science. EDX provides a positive identification of phosphorus, but importantly, the method need not involve a more severe electron dose than that required for imaging. The approach should prove useful in general for mapping of heavy elements in cryopreserved specimens when the element identity is known from the biological context. © 2015 The Authors Journal of Microscopy © 2015 Royal Microscopical Society.

  2. Mechanical Properties of Air Plasma Sprayed Environmental Barrier Coating (EBC) Materials

    Science.gov (United States)

    Richards, Bradley; Zhu, Dongming; Ghosn, Louis; Wadley, Haydn

    2015-01-01

    Development work in Environmental Barrier Coatings (EBCs) for Ceramic Matrix Composites (CMCs) has focused considerably on the identification of materials systems and coating architectures to meet application needs. The evolution of these systems has occurred so quickly that modeling efforts and requisite data for modeling lag considerably behind development. Materials property data exists for many systems in the bulk form, but the effects of deposition on the critical properties of strength and fracture behavior are not well studied. We have plasma sprayed bulk samples of baseline EBC materials (silicon, ytterbium disilicate) and tested the mechanical properties of these materials to elicit differences in strength and toughness. We have also endeavored to assess the mixed-mode fracture resistance, Gc, of silicon in a baseline EBC applied to SiCSiC CMC via four point bend test. These results are compared to previously determined properties of the comparable bulk material.

  3. Magnetic Ignition of Pulsed Gas Discharges in Air of Low Pressure in a Coaxial Plasma Gun

    Science.gov (United States)

    Thom, Karlheinz; Norwood, Joseph, Jr.

    1961-01-01

    The effect of an axial magnetic field on the breakdown voltage of a coaxial system of electrodes has been investigated by earlier workers. For low values of gas pressure times electrode spacing, the breakdown voltage is decreased by the application of the magnetic field. The electron cyclotron radius now assumes the role held by the mean free path in nonmagnetic discharges and the breakdown voltage becomes a function of the magnetic flux density. In this paper the dependence of the formative time lag as a function of the magnetic flux density is established and the feasibility of using a magnetic field for igniting high-voltage, high-current discharges is shown through theory and experiment. With a 36 microfarad capacitor bank charged to 48,000 volts, a peak current of 1.3 x 10( exp 6) amperes in a coaxial type of plasma gun was achieved with a current rise time of only 2 microseconds.

  4. Manganese oxide octahedral molecular sieve K-OMS-2 as catalyst in post plasma-catalysis for trichloroethylene degradation in humid air

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen Dinh, M.T. [Université Lille, Sciences et Technologies, Unité de Catalyse et Chimie du Solide UMR CNRS UCCS 8181, 59655 Villeneuve d’Ascq (France); The University of Da-Nang, University of Science and Technology, 54, Nguyen Luong Bang, Da-Nang (Viet Nam); Giraudon, J.-M., E-mail: jean-marc.giraudon@univ-lille1.fr [Université Lille, Sciences et Technologies, Unité de Catalyse et Chimie du Solide UMR CNRS UCCS 8181, 59655 Villeneuve d’Ascq (France); Vandenbroucke, A.M.; Morent, R.; De Geyter, N. [Ghent University, Faculty of Engineering and Architecture, Department of Applied Physics, Research Unit Plasma Technology, Sint-Pietersnieuwstraat 41, 9000 Ghent (Belgium); Lamonier, J.-F. [Université Lille, Sciences et Technologies, Unité de Catalyse et Chimie du Solide UMR CNRS UCCS 8181, 59655 Villeneuve d’Ascq (France)

    2016-08-15

    Highlights: • Post plasma catalysis: negative DC glow discharge combined with a cryptomelane. • The α-MnO{sub 2} catalyst totally decomposes the NTP generated ozone. • Active oxygen oxidizes the end-up plasma VOC by-products. - Abstract: The total oxidation of trichloroethylene (TCE) in air at low relative humidity (RH = 10%) in the presence of CO{sub 2} (520 ppmv) was investigated in function of energy density using an atmospheric pressure negative DC luminescent glow discharge combined with a cryptomelane catalyst positioned downstream of the plasma reactor at a temperature of 150 °C. When using Non-Thermal Plasma (NTP) alone, it is found a low COx (x = 1–2) yield in agreement with the detection of gaseous polychlorinated by-products in the outlet stream as well as ozone which is an harmful pollutant. Introduction of cryptomelane enhanced trichloroethylene removal, totally inhibited plasma ozone formation and increased significantly the COx yield. The improved performances of the hybrid system were mainly ascribed to the total destruction of plasma generated ozone on cryptomelane surface to produce active oxygen species. Consequently these active oxygen species greatly enhanced the abatement of the plasma non-reacted TCE and completely destroyed the hazardous plasma generated polychlorinated intermediates. The facile redox of Mn species associated with oxygen vacancies and mobility as well as the textural properties of the catalyst might also contribute as a whole to the efficiency of the process.

  5. Effect of duty-cycles on the air plasma gas-phase of dielectric barrier discharges

    Science.gov (United States)

    Barni, R.; Biganzoli, I.; Dell'Orto, E. C.; Riccardi, C.

    2015-10-01

    An experimental investigation concerning the effects of a duty-cycle in the supply of a dielectric barrier discharge in atmospheric pressure air has been performed. Electrical characteristics of the discharge have been measured, focusing mainly on the statistical properties of the current filaments and on dielectric surface charging, both affected by the frequent repetition of breakdown imposed by the duty-cycle. Information on the gas-phase composition was gathered too. In particular, a strong enhancement in the ozone formation rate is observed when suitable long pauses separate the active discharge phases. A simulation of the chemical kinetics in the gas-phase, based on a simplified discharge modeling, is briefly described in order to shed light on the observed increase in ozone production. The effect of a duty-cycle on surface modification of polymeric films in order to increase their wettability has been investigated too.

  6. Process-Property Relationship for Air Plasma-Sprayed Gadolinium Zirconate Coatings

    Science.gov (United States)

    Dwivedi, Gopal; Tan, Yang; Viswanathan, Vaishak; Sampath, Sanjay

    2015-02-01

    The continuous need of elevating operating temperature of gas turbine engines has introduced several challenges with the current state-of-the-art yttria-stabilized zirconia (YSZ)-based thermal barrier coatings (TBCs), requiring examination of new TBC material with high temperature phase stability, lower thermal conductivity, and resistance to environmental ash particles. Gadolinium zirconate (Gd2Zr2O7) (GDZ) has been shown to meet many of these requirements, and has, in fact, been successfully implemented in to engine components. However, several fundamental issues related to the process-ability, toughness, and microstructural differences for GDZ when compared to equivalent YSZ coating. This study seeks to critically address the process-structure-property correlations for plasma-sprayed GDZ coating subjected to controlled parametric exploration. Use of in-flight diagnostics coupled with in situ and ex situ coating property monitoring allows examination and comparison of the process-property interplay and the resultant differences between the two TBC compositions. The results indicate that it is feasible to retain material chemistry and fabricate relevant microstructures of interest with GDZ with concomitant performance advantages such as low conductivity, mechanical compliance, sintering resistance, and suppression of environmentally induced damage from ash particles. This study provides a framework for optimal design and manufacturing of emergent multi-layer and multi-material TBCs.

  7. Plasma decay in air and O2 after a high-voltage nanosecond discharge

    Science.gov (United States)

    Aleksandrov, N. L.; Anokhin, E. M.; Kindysheva, S. V.; Kirpichnikov, A. A.; Kosarev, I. N.; Nudnova, M. M.; Starikovskaia, S. M.; Starikovskii, A. Yu

    2012-06-01

    This paper presents the results of experimental and theoretical studies of an afterglow in room temperature air and O2 excited by a high-voltage nanosecond discharge for pressures between 1 and 10 Torr. We measured time-resolved electron density by a microwave interferometer for initial electron densities in the range (2-3) × 1012 cm-3. Discharge uniformity was investigated by optical methods. The balance equations for charged particles and electron temperature were numerically solved to describe the temporal evolution of the densities of electrons and ions in the discharge afterglow. It was shown that the loss of electrons is governed by dissociative and three-body electron recombination with O_2^+ ions under the conditions considered. Good agreement between the calculated and measured electron density histories could be obtained only when the rate of three-body recombination was increased by an order of magnitude and when the dependence of the recombination rate on electron temperature was changed. This could testify that the well-understood mechanism of three-body electron recombination with atomic ions could be noticeably modified in the case of molecular ions.

  8. Microstructure and mechanical properties of air atomized aluminum powder consolidated via spark plasma sintering

    Energy Technology Data Exchange (ETDEWEB)

    Sweet, G.A. [Dalhousie University, Department of Process Engineering and Applied Science, 1360 Barrington Street, Halifax, Nova Scotia, Canada B3J 1Z1 (Canada); Brochu, M. [McGill University, Mining and Materials Engineering Department, 3610 University Street, Montreal, Quebec, Canada H3A 0C5 (Canada); Hexemer, R.L.; Donaldson, I.W. [GKN Sinter Metals LLC, 3300 University Drive, Auburn Hills 48326 (United States); Bishop, D.P., E-mail: Paul.Bishop@dal.ca [Dalhousie University, Department of Process Engineering and Applied Science, 1360 Barrington Street, Halifax, Nova Scotia, Canada B3J 1Z1 (Canada)

    2014-07-01

    Two air atomized aluminum powders, one of commercial purity and the other magnesium-doped (0.4 wt%), were processed by SPS and conventional PM means. An investigation of SPS processing parameters and their effect on sinter quality were investigated. A comparison with conventionally processed PM counterparts was also conducted. Applied pressure and ultimate processing temperature bore the greatest influence on processing, while heating rate and hold time showed a minor effect. Full density specimens were achieved for both powders under select processing conditions. To compliment this, large (80 mm) and small (20 mm) diameter samples were made to observe possible up-scaling effects, as well as tensile properties. Large samples were successfully processed, albeit with somewhat inferior densities to the smaller counterparts presumably due to the temperature inhomogeneity during processing. An investigation of tensile properties for SPS samples exhibited extensive ductility (∼30%) at high sintering temperatures, while lower temperature SPS samples as well as all PM processed samples exhibited a brittle nature. The measurement of residual oxygen and hydrogen contents showed a significant elimination of both species in SPS samples under certain processing parameters when compared to conventional PM equivalents.

  9. Radially and temporally resolved electric field of positive streamers in air and modelling of the induced plasma chemistry

    Science.gov (United States)

    Hoder, T.; Šimek, M.; Bonaventura, Z.; Prukner, V.; Gordillo-Vázquez, F. J.

    2016-08-01

    The initial stages of transient luminous events (TLEs) occurring in the upper atmosphere of the Earth are, in a certain pressure range, controlled by the streamer mechanism. This paper presents the results of the first laboratory experiments to study the TLE streamer phenomena under conditions close to those of the upper atmosphere. Spectrally and highly spatiotemporally resolved emissions originating from radiative states {{\\text{N}}2}≤ft({{\\text{C}}3}{{\\Pi}u}\\right) (second positive system) and \\text{N}2+≤ft({{\\text{B}}2}Σu+\\right) (first negative system) have been recorded from the positive streamer discharge. Periodic ionizing events were generated in a barrier discharge arrangement at a pressure of 4 torr of synthetic air, i.e. simulating the pressure conditions at altitudes of ≃37 km. Employing Abel inversion on the radially scanned streamer emission and a 2D fitting procedure, access was obtained to the local spectral signatures within the over 106  m s-1 fast propagating streamers. The reduced electric field strength distribution within the streamer head was determined from the ratio of the \\text{N}2+/{{\\text{N}}2} band intensities with peak values up to 500 Td and overall duration of about 10 ns. The 2D profiles of the streamer head electric fields were used as an experimentally obtained input for kinetic simulations of the streamer-induced air plasma chemistry. The radial and temporal computed distribution of the ground vibrational levels of the radiative states involved in the radiative transitions analyzed (337.1 nm and 391.5 nm), atomic oxygen, nitrogen, nitric oxide and ozone concentrations are vizualized and discussed in comparison with available models of the streamer phase of Blue Jet discharges in the stratosphere.

  10. Formation of oxygen vacancies and Ti3+ state in TiO2 thin film and enhanced optical properties by air plasma treatment

    Science.gov (United States)

    Bharti, Bandna; Kumar, Santosh; Lee, Heung-No; Kumar, Rajesh

    2016-08-01

    This is the first time we report that simply air plasma treatment can also enhances the optical absorbance and absorption region of titanium oxide (TiO2) films, while keeping them transparent. TiO2 thin films having moderate doping of Fe and Co exhibit significant enhancement in the aforementioned optical properties upon air plasma treatment. The moderate doping could facilitate the formation of charge trap centers or avoid the formation of charge recombination centers. Variation in surface species viz. Ti3+, Ti4+, O2‑, oxygen vacancies, OH group and optical properties was studied using X-ray photon spectroscopy (XPS) and UV-Vis spectroscopy. The air plasma treatment caused enhanced optical absorbance and optical absorption region as revealed by the formation of Ti3+ and oxygen vacancies in the band gap of TiO2 films. The samples were treated in plasma with varying treatment time from 0 to 60 seconds. With the increasing treatment time, Ti3+ and oxygen vacancies increased in the Fe and Co doped TiO2 films leading to increased absorbance; however, the increase in optical absorption region/red shift (from 3.22 to 3.00 eV) was observed in Fe doped TiO2 films, on the contrary Co doped TiO2 films exhibited blue shift (from 3.36 to 3.62 eV) due to Burstein Moss shift.

  11. A numerical study of pulverized coal ignition by means of plasma torches in air-coal dust mixture ducts of utility boiler furnaces

    Energy Technology Data Exchange (ETDEWEB)

    Belosevic, S.; Sijercic, M.; Stefanovic, P. [Institute for Nuclear Science Vinca, Belgrade (Serbia)

    2008-04-15

    Paper presents selected results of numerical simulation of processes in air-coal dust mixture duct of pulverized coal utility boiler furnace with plasma-system for pulverized coal ignition and combustion stabilization. Application of the system in utility boiler furnaces promises to achieve important savings compared with the use of heavy oil burners. Plasma torches are built in air-coal dust mixture ducts between coal mills and burners. Calculations have been performed for one of rectangular air-coal dust mixture ducts with two opposite plasma torches, used in 210 MWe utility boiler firing pulverized Serbian lignite. The simulations are based on a three-dimensional mathematical model of mass, momentum and heat transfer in reacting turbulent gas-particle flow, specially developed for the purpose. Characteristics of processes in the duct are analyzed in the paper, with respect to the numerical results. The plasma-system thermal effect is discussed as well, regarding corresponding savings of liquid fuel. It has been emphasized that numerical simulation of the processes can be applied in optimization of pulverized coal ignition and combustion stabilization and enables efficient and cost-effective scaling-up procedure from laboratory to industrial scale.

  12. Survival, Fertilization and Developmental Rates of Cryotop-Vitrified Oocyte and Embryo Using Low Concentrated Cryoprotectants

    Directory of Open Access Journals (Sweden)

    A Roozbehi

    2012-10-01

    Full Text Available Background & Aim: The preserving embryos, the risk of multiple pregnancies, the existence of factors in stimulated uterine cycle, are important forces in perfecting embryo cryopreservation. The aim of current study was to assess Survival, Fertilization and Developmental Rates (SRs, FRs, DRs of the mouse oocytes and embryos using cryotop and low concentrated cryoprotectants solutions. Methods: Mouse C57BL/6 oocytes and embryos were collected. Oocytes SRs, FRs, DRs were recorded after cryotop-vitrification/ warming. As well as comparing fresh oocytes and embryos, the data obtained from experimental groups (exp. applying 1.25, 1.0, and 0.75 Molar (M CPAs were analyzed in comparison to those of exp. adopting 1.5 M CPAs (largely-used concentration of EthylenGlycol (EG and Dimethylsulphoxide (DMSO. Results: The data of oocytes exposed to 1.25 M CPAs were in consistency with those exposed to 1.5 M and control group in terms of SR, FR and DR. As fewer concentrations were applied, the more decreased SRs, FRs and DRs were obtained from other experimental groups. The results of embryos were exposed to 1.25 M and 1.0 M was close to those vitrified with 1.5 M and fresh embryos. The results of 0.75 M concentrated CPAs solutions were significantly lower than those of control, 1.5 M and 1.0 M treated groups. Conclusion: CPAs limited reduction to 1.25 M and 1.0 M instead of using 1.5 M, for oocyte and embryo cryotop-vitrification procedure may be a slight adjustment.

  13. Phase transformations in air plasma-sprayed yttria-stabilized zirconia thermal barrier coatings

    Directory of Open Access Journals (Sweden)

    Julián D. Osorio

    2014-01-01

    Full Text Available En este trabajo, las transformaciones de fase en Recubrimientos de Barrera Térmica (TBC constituidos por ZrO 2 – 8 wt.% Y2O3 (zirconia - 8 wt.% ytrria fueron estudiados a través de Difracción de Rayos X (XRD y refinamiento Rietveld. Las muestras de TBC fueron depositadas mediante aspersión por plasma atmosférico sobre un sustrato tipo Inconel 625 y fueron tratadas térmicamente con dos condiciones diferentes: en la primera se utilizó una temperatura de 1100oC con tiempos de exposición entre 1 hora y 1000 horas; en la segunda las muestras fueron sometidas a temperaturas entre 700oC y 1100o durante 50 horas. De acuerdo a los resultados obtenidos mediante refinamiento Rietveld el contenido de fase cúbica en el recubrimiento (TC se incrementa con el tiempo y la temperatura, desde 7.3 wt.% hasta 15.7 wt.% después de 1000 horas a 1100oC. La fase cúbica en grandes cantidades es indeseable debido a que presenta inferiores propiedades mecánicas cuando se compara con la fase tetragonal. Después de 800 horas de exposición a alta temperatura, el contenido de Y2O3 en la fase tetragonal se reduce hasta 6.6 wt.% y una fracción de la fase tetragonal transforma a monoclínica durante el enfriamiento. La fase monoclínica alcanza 18.0 wt.% después de 1000 horas. Esta fase es también indeseable porque además de tener una mayor conductividad térmica, la transformación de tetragonal a monoclínica viene acompañada de un cambio volumétrico de alrededor de 5% que promueve la formación y propagación de grietas, las cuales comprometen la integridad del recubrimiento.

  14. Development of hydrophilic dental wax without surfactant using a non-thermal air atmospheric pressure plasma jet

    Science.gov (United States)

    Lee, Jung-Hwan; Kim, Yong-Hee; Choi, Eun-Ha; Kim, Kwang-Mahn; Kim, Kyoung-Nam

    2014-06-01

    Dental wax (DW), a low-melting and high-molecular-weight organic mixture, is widely used in dentistry for forming moulds of teeth. Hydrophilicity is an important property for DW, as a wet dental investment is used to surround the wax before wax burnout is performed. However, recent attempts to improve the hydrophilicity of DW using a surfactant have resulted in the reduced mechanical properties of the dental investment, leading to the failure of the dental restoration. This study applied a non-thermal air atmospheric pressure plasma jet (AAPPJ) for DW surface treatment and investigated its effect on both DW hydrophilicity and the dental investment's mechanical properties. The results showed that the application of the AAPPJ significantly improved the hydrophilicity of the DW, and that the results were similar to that of cleaner-treated DW using commercially available products with surfactant. A surface chemical analysis indicated that the improvement of hydrophilicity was related to an increase in the number of oxygen-related bonds on the DW surface following the removal of carbon hydrate in both AAPPJ and cleaner-treated DW. However, cleaner treatment compromised the mechanical property of the dental investment when the dental investment was in contact with the treated DW, while the AAPPJ treatment did not. Therefore, the use of AAPPJ to treat DW is a promising method for accurate dental restoration, as it induces an improvement in hydrophilicity without harming the dental investment.

  15. Thermodynamic properties and transport coefficients of air thermal plasmas mixed with ablated vapors of Cu and polytetrafluoroethylene

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, JunMin, E-mail: jmzhang@buaa.edu.cn, E-mail: guanyg@tsinghua.edu.cn; Lu, ChunRong [School of Automation Science and Electrical Engineering, Beihang University, Beijing 100191 (China); Guan, YongGang, E-mail: jmzhang@buaa.edu.cn, E-mail: guanyg@tsinghua.edu.cn; Liu, WeiDong [Department of Electrical Engineering, Tsinghua University, Beijing 100084 (China)

    2015-10-15

    Because the fault arc in aircraft electrical system often causes a fire, it is particularly important to analyze its energy and transfer for aircraft safety. The calculation of arc energy requires the basic parameters of the arc. This paper is mainly devoted to the calculations of equilibrium composition, thermodynamic properties (density, molar weight, enthalpy, and specific heat at constant pressure) and transport coefficients (thermal conductivity, electrical conductivity, and viscosity) of plasmas produced by a mixture of air, Cu, and polytetrafluoroethylene under the condition of local thermodynamic equilibrium. The equilibrium composition is determined by solving a system of equations around the number densities of each species. The thermodynamic properties are obtained according to the standard thermodynamic relationships. The transport coefficients are calculated using the Chapman-Enskog approximations. Results are presented in the temperature range from 3000 to 30 000 K for pressures of 0.08 and 0.1 MPa, respectively. The results are more accurate and are reliable reference data for theoretical analysis and computational simulation of the behavior of fault arc.

  16. Characterization and Wear Behavior of Heat-treated Ni3Al Coatings Deposited by Air Plasma Spraying

    Science.gov (United States)

    Mehmood, K.; Rafiq, M. A.; Nusair Khan, A.; Ahmed, F.; Mudassar Rauf, M.

    2016-07-01

    Air plasma spraying was utilized to deposit Ni3Al coatings on AISI-321 steel substrate. The deposited coatings were isothermally heat-treated at various temperatures from 500 to 800 °C for 10, 30, 60, and 100 h. The x-ray diffraction analysis revealed NiO formation in Ni3Al at 500 °C after 100 h, and the percentage of NiO increased with increasing exposure time and temperature. The hardness of the coating increased with the formation of NiO. The DSC test showed the formation of minor phases, Al3Ni and Al3Ni2, within the coating along with the major phase Ni3Al. TGA revealed a slowing down of the oxidation rate upon surface oxide formation. The pin-on-disk wear test on the as-sprayed and heat-treated coatings showed that wear rate and coefficient of friction decreased with an increase in the NiO phase content.

  17. Phosphor-Doped Thermal Barrier Coatings Deposited by Air Plasma Spray for In-Depth Temperature Sensing.

    Science.gov (United States)

    Peng, Di; Yang, Lixia; Cai, Tao; Liu, Yingzheng; Zhao, Xiaofeng; Yao, Zhiqi

    2016-09-28

    Yttria-stabilized zirconia (YSZ)-based thermal barrier coating (TBC) has been integrated with thermographic phosphors through air plasma spray (APS) for in-depth; non-contact temperature sensing. This coating consisted of a thin layer of Dy-doped YSZ (about 40 µm) on the bottom and a regular YSZ layer with a thickness up to 300 µm on top. A measurement system has been established; which included a portable; low-cost diode laser (405 nm); a photo-multiplier tube (PMT) and the related optics. Coating samples with different topcoat thickness were calibrated in a high-temperature furnace from room temperature to around 900 °C. The results convincingly showed that the current sensor and the measurement system was capable of in-depth temperature sensing over 800 °C with a YSZ top layer up to 300 µm. The topcoat thickness was found to have a strong effect on the luminescent signal level. Therefore; the measurement accuracy at high temperatures was reduced for samples with thick topcoats due to strong light attenuation. However; it seemed that the light transmissivity of YSZ topcoat increased with temperature; which would improve the sensor's performance at high temperatures. The current sensor and the measurement technology have shown great potential in on-line monitoring of TBC interface temperature.

  18. Improved Thermally Grown Oxide Scale in Air Plasma Sprayed NiCrAlY/Nano-YSZ Coatings

    Directory of Open Access Journals (Sweden)

    Mohammadreza Daroonparvar

    2013-01-01

    Full Text Available Oxidation has been considered as one of the principal disruptive factors in thermal barrier coating systems during service. So, oxidation behavior of thermal barrier coating (TBC systems with nanostructured and microstructured YSZ coatings was investigated at 1000∘C for 24 h, 48 h, and 120 h. Air plasma sprayed nano-YSZ coating exhibited a trimodal structure. Microstructural characterization also demonstrated an improved thermally grown oxide scale containing lower spinels in nano-TBC system after 120 h of oxidation. This phenomenon is mainly related to the unique structure of the nano-YSZ coating, which acted as a strong barrier for oxygen diffusion into the TBC system at elevated temperatures. Nearly continues but thinner Al2O3 layer formation at the NiCrAlY/nano-YSZ interface was seen, due to lower oxygen infiltration into the system. Under this condition, spinels formation and growth on the Al2O3 oxide scale were diminished in nano-TBC system compared to normal TBC system.

  19. Phosphor-Doped Thermal Barrier Coatings Deposited by Air Plasma Spray for In-Depth Temperature Sensing

    Directory of Open Access Journals (Sweden)

    Di Peng

    2016-09-01

    Full Text Available Yttria-stabilized zirconia (YSZ-based thermal barrier coating (TBC has been integrated with thermographic phosphors through air plasma spray (APS for in-depth; non-contact temperature sensing. This coating consisted of a thin layer of Dy-doped YSZ (about 40 µm on the bottom and a regular YSZ layer with a thickness up to 300 µm on top. A measurement system has been established; which included a portable; low-cost diode laser (405 nm; a photo-multiplier tube (PMT and the related optics. Coating samples with different topcoat thickness were calibrated in a high-temperature furnace from room temperature to around 900 °C. The results convincingly showed that the current sensor and the measurement system was capable of in-depth temperature sensing over 800 °C with a YSZ top layer up to 300 µm. The topcoat thickness was found to have a strong effect on the luminescent signal level. Therefore; the measurement accuracy at high temperatures was reduced for samples with thick topcoats due to strong light attenuation. However; it seemed that the light transmissivity of YSZ topcoat increased with temperature; which would improve the sensor’s performance at high temperatures. The current sensor and the measurement technology have shown great potential in on-line monitoring of TBC interface temperature.

  20. Advanced separation and transmutation, long dated behavior of vitrified wastes: 15 years of scientific researches; Separation poussee et transmutation, comportement a long terme des dechets vitrifies: 15 ans d'avancees scientifiques

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-02-15

    This report presents the results after 15 years of researches at the Cea, concerning the separation and transmutation of radioactive wastes and the conditioning and the long time storage of wastes at the surface. These researches were asked in the framework of the Bataille law. The first part devoted to the transmutation and separation of ling life radioactive elements presents the challenges, the advanced separation, the transmutation and the evaluation of the researches. The second part devoted to the long dated storage discusses the high activity wastes vitrification, the behavior of the vitrified wastes packages after thousand years, the international researches and the evaluation of the researches. (A.L.B.)

  1. Study of Air Pollution Due to Plasma Cutting Process and Designing Local Ventilation System with Collector in Central Workshop of Mobarakeh Steel Company

    Directory of Open Access Journals (Sweden)

    Farideh Atabi

    2014-06-01

    Full Text Available Background & Objectives : Cutting leads to production of different hazardous agents such as fumes, particles, gases and vapors. In various studies, the effects of fumes, gases, and vapors on workers and environment have been proved. Meanwhile, cutting alloying plates with plasma cutting machine due to containing various alloy materials produces a lot of air pollution. Therefore, using the ventilation system to remove the mentioned pollution has always been noteworthy. Method: This study was performed on plasma cutting machine at Mobarakeh Steel Company. At first, according to ASTM the elements from alloy plates with optical emission spectrometry crm-35000-quantometery were detected, the air pollution from cutting the mentioned plates was sampled and measured using NIOSH 7300 method and according to the ACGIH:VS-72-20, VS-70-12, VS-70-11 VS-916 push-pull ventilation with bag filter collector was designed. Results: Results of sampling from pollution of cutting the alloy material, concentration of iron, lead and cadmium fumes were more than the standard limits. After calculation for push system, air flow volume of 195.163 cfm, outgoing air velocity of 5937.4 fpm and for pull system air flow volume of 12498 cfm, minimum duct velocity of 3000 fpm and velocity pressure of duct of 0.717 inwg, for fan, total pressure of 6.301 inwg, static pressure of 0.587 inwg and power of 20.65 Bhp and for collector with pulse jet cleaning system air to cloth ratio of 7 and dimensions of 6.88ft × 6.56ft × 9.84ft were obtained. Conclusion: The result of study indicated that push pull ventilation compared to other ventilation system s for plasma cutting has more efficiency and makes suitable control for pollution.

  2. Suprathermal electron energy spectrum and nonlocally affected plasma-wall interaction in helium/air micro-plasma at atmospheric pressure

    Science.gov (United States)

    Demidov, V. I.; Adams, S. F.; Miles, J. A.; Koepke, M. E.; Kurlyandskaya, I. P.

    2016-10-01

    Details of ground-state and excited-state neutral atoms and molecules in an atmospheric-pressure micro-discharge plasma may be obtained by plasma electron spectroscopy (PLES), based on a wall probe. The presence and transport of energetic (suprathermal) electrons, having a nonlocal origin, are responsible for electrostatic charging of the plasma boundary surfaces to potentials many times that associated with the ambient electron kinetic energy. The energy-flux distribution function is shown to be controllable for applications involving analysis of composition and processes taking place in a multiphase (plasma-gas-solid), chemically reactive, interaction region.

  3. A Review and Analysis of European Industrial Experience in Handling LWR Spent Fuel and Vitrified High-Level Waste

    Energy Technology Data Exchange (ETDEWEB)

    Blomeke, J.O.

    2001-07-10

    The industrial facilities that have been built or are under construction in France, the United Kingdom, Sweden, and West Germany to handle light-water reactor (LWR) spent fuel and canisters of vitrified high-level waste before ultimate disposal are described and illustrated with drawings and photographs. Published information on the operating performance of these facilities is also given. This information was assembled for consideration in planning and design of similar equipment and facilities needed for the Federal Waste Management System in the United States.

  4. Comments on a paper tilted `The sea transport of vitrified high-level radioactive wastes: Unresolved safety issues`

    Energy Technology Data Exchange (ETDEWEB)

    Sprung, J.L.; McConnell, P.E.; Nigrey, P.J.; Ammerman, D.J. [and others

    1997-05-01

    The cited paper estimates the consequences that might occur should a purpose-built ship transporting Vitrified High Level Waste (VHLW) be involved in a severe collision that causes the VHLW canisters in one Type-B package to spill onto the floor of a major ocean fishing region. Release of radioactivity from VHLW glass logs, failure of elastomer cask seals, failure of VHLW canisters due to stress corrosion cracking (SCC), and the probabilities of the hypothesized accident scenario, of catastrophic cask failure, and of cask recovery from the sea are all discussed.

  5. Development and Evaluation of an Externally Air-Cooled Low-Flow torch and the Attenuation of Space Charge and Matrix Effects in Inductively Coupled Plasma Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Praphairaksit, Narong [Iowa State Univ., Ames, IA (United States)

    2000-09-12

    An externally air-cooled low-flow torch has been constructed and successfully demonstrated for applications in inductively coupled plasma mass spectrometry (ICP-MS). The torch is cooled by pressurized air flowing at ~70 L/min through a quartz air jacket onto the exterior of the outer tube. The outer gas flow rate and operating RF forward power are reduced considerably. Although plasmas can be sustained at the operating power as low as 400 W with a 2 L/min of outer gas flow, somewhat higher power and outer gas flows are advisable. A stable and analytical useful plasma can be obtained at 850 W with an outer gas flow rate of ~4 L/min. Under these conditions, the air-cooled plasma produces comparable sensitivities, doubly charged ion ratios, matrix effects and other analytical merits as those produced by a conventional torch while using significantly less argon and power requirements. Metal oxide ion ratios are slightly higher with the air-cooled plasma but can be mitigated by reducing the aerosol gas flow rate slightly with only minor sacrifice in analyte sensitivity. A methodology to alleviate the space charge and matrix effects in ICP-MS has been developed. A supplemental electron source adapted from a conventional electron impact ionizer is added to the base of the skimmer. Electrons supplied from this source downstream of the skimmer with suitable amount and energy can neutralize the positive ions in the beam extracted from the plasma and diminish the space charge repulsion between them. As a result, the overall ion transmission efficiency and consequent analyte ion sensitivities are significantly improved while other important analytical aspects, such as metal oxide ion ratio, doubly charged ion ratio and background ions remain relatively unchanged with the operation of this electron source. This technique not only improves the ion transmission efficiency but also minimizes the matrix effects drastically. The matrix-induced suppression of signal for even the most

  6. Development and Evaluation of an Externally Air-Cooled Low-Flow torch and the Attenuation of Space Charge and Matrix Effects in Inductively Coupled Plasma Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Praphairaksit, N.

    2000-09-12

    An externally air-cooled low-flow torch has been constructed and successfully demonstrated for applications in inductively coupled plasma mass spectrometry (ICP-MS). The torch is cooled by pressurized air flowing at {approximately}70 L/min through a quartz air jacket onto the exterior of the outer tube. The outer gas flow rate and operating RF forward power are reduced considerably. Although plasmas can be sustained at the operating power as low as 400 W with a 2 L/min of outer gas flow, somewhat higher power and outer gas flows are advisable. A stable and analytical useful plasma can be obtained at 850 W with an outer gas flow rate of {approximately}4 L/min. Under these conditions, the air-cooled plasma produces comparable sensitivities, doubly charged ion ratios, matrix effects and other analytical merits as those produced by a conventional torch while using significantly less argon and power requirements. Metal oxide ion ratios are slightly higher with the air-cooled plasma but can be mitigated by reducing the aerosol gas flow rate slightly with only minor sacrifice in analyte sensitivity. A methodology to alleviate the space charge and matrix effects in ICP-MS has been developed. A supplemental electron source adapted from a conventional electron impact ionizer is added to the base of the skimmer. Electrons supplied from this source downstream of the skimmer with suitable amount and energy can neutralize the positive ions in the beam extracted from the plasma and diminish the space charge repulsion between them. As a result, the overall ion transmission efficiency and consequent analyte ion sensitivities are significantly improved while other important analytical aspects, such as metal oxide ion ratio, doubly charged ion ratio and background ions remain relatively unchanged with the operation of this electron source. This technique not only improves the ion transmission efficiency but also minimizes the matrix effects drastically. The matrix-induced suppression

  7. Manganese oxide octahedral molecular sieve K-OMS-2 as catalyst in post plasma-catalysis for trichloroethylene degradation in humid air.

    Science.gov (United States)

    Nguyen Dinh, M T; Giraudon, J-M; Vandenbroucke, A M; Morent, R; De Geyter, N; Lamonier, J-F

    2016-08-15

    The total oxidation of trichloroethylene (TCE) in air at low relative humidity (RH=10%) in the presence of CO2 (520ppmv) was investigated in function of energy density using an atmospheric pressure negative DC luminescent glow discharge combined with a cryptomelane catalyst positioned downstream of the plasma reactor at a temperature of 150°C. When using Non-Thermal Plasma (NTP) alone, it is found a low COx (x=1-2) yield in agreement with the detection of gaseous polychlorinated by-products in the outlet stream as well as ozone which is an harmful pollutant. Introduction of cryptomelane enhanced trichloroethylene removal, totally inhibited plasma ozone formation and increased significantly the COx yield. The improved performances of the hybrid system were mainly ascribed to the total destruction of plasma generated ozone on cryptomelane surface to produce active oxygen species. Consequently these active oxygen species greatly enhanced the abatement of the plasma non-reacted TCE and completely destroyed the hazardous plasma generated polychlorinated intermediates. The facile redox of Mn species associated with oxygen vacancies and mobility as well as the textural properties of the catalyst might also contribute as a whole to the efficiency of the process.

  8. Mass spectrometric investigations of air, N{sub 2}, CO{sub 2}/N{sub 2} and N{sub 2}/CH{sub 4} - plasmas in the SR1 wind tunnel

    Energy Technology Data Exchange (ETDEWEB)

    Schoenemann, A.

    1995-06-01

    The investigation of the plasma composition and particle distributions is carried out in the SR1 plasma wind tunnel, with the quadrupole mass spectrometer installed at the end of the vacuum chamber opposite to the plasma generator. Axial and radial particle distributions are obtained by moving the plasma generator. The system of displacement gives an axial range of 65 cm and a range of 40 cm perpendicular to the plasma jet axis, with total distances up to 1 m. Different plasma conditions with various gas mixtures have been investigated: pure nitrogen, air, air / argon, carbon dioxide / nitrogen and nitrogen / methane plasma. The current was set to a constant value of 100 A for all gas mixtures. Results are given and compared. 10 refs., 55 figs., 7 tabs.

  9. Experimental and numerical investigations of air plasmas induced by multi-MeV pulsed X-ray from low to atmospheric pressures

    Science.gov (United States)

    Maulois, Mélissa; Ribière, Maxime; Eichwald, Olivier; Yousfi, Mohammed; Pouzalgues, Romain; Garrigues, Alain; Delbos, Christophe; Azaïs, Bruno

    2016-09-01

    This research work is devoted to the experimental and theoretical analysis of air plasmas induced by multi-MeV pulsed X-ray for a large pressure range of humid air background gas varying from 20 mbar to atmospheric pressure. The time evolution of the electron density of the air plasma is determined by electromagnetic wave absorption measurements. The measurements have uncertainties of about ±30%, taking into account the precision of the dose measurement and also the shot to shot fluctuations of the generator. The experimental electron density is obtained by comparing the measurements of the transmitted microwave signals to the calculated ones. The calculations need the knowledge of the time evolution of the electron mean energy, which is determined by a chemical kinetic model based on a reaction scheme involving 39 species interacting following 265 reactions. During the X-ray pulse, a good agreement is obtained between time evolution of the electron density obtained from absorption measurements and calculations based on the kinetic model. The relative deviation on the maximum electron density and the corresponding plasma frequency is always lower than 10%. The maximum electron density varies from 4 × 1011 to 3.5 × 1013 cm-3 between 30 mbar to atmospheric pressure, while the peak of the electron mean energy decreases from 5.64 eV to 4.27 eV in the same pressure range.

  10. Estimation of Minimal Breakdown Point in a GaP Plasma Structure and Discharge Features in Air and Argon Media

    Science.gov (United States)

    Kurt, H. Hilal; Tanrıverdi, Evrim

    2016-08-01

    We present gas discharge phenomena in argon and air media using a gallium phosphide (GaP) semiconductor and metal electrodes. The system has a large-diameter ( D) semiconductor and a microscaled adjustable interelectrode gap ( d). Both theoretical and experimental findings are discussed for a direct-current (dc) electric field ( E) applied to this structure with parallel-plate geometry. As one of the main parameters, the pressure p takes an adjustable value from 0.26 kPa to 101 kPa. After collection of experimental data, a new theoretical formula is developed to estimate the minimal breakdown point of the system as a function of p and d. It is proven that the minimal breakdown point in the semiconductor and metal electrode system differs dramatically from that in metal and metal electrode systems. In addition, the surface charge density σ and spatial electron distribution n e are calculated theoretically. Current-voltage characteristics (CVCs) demonstrate that there exist certain negative differential resistance (NDR) regions for small interelectrode separations (i.e., d = 50 μm) and low and moderate pressures between 3.7 kPa and 13 kPa in Ar medium. From the difference of currents in CVCs, the bifurcation of the discharge current is clarified for an applied voltage U. Since the current differences in NDRs have various values from 1 μA to 7.24 μA for different pressures, the GaP semiconductor plasma structure can be used in microwave diode systems due to its clear NDR region.

  11. No Peri- and Postnatal Effects on Calves Born After Transfer of in Vitro Produced Embryos Vitrified by the Open Pulled Straw (OPS Method

    Directory of Open Access Journals (Sweden)

    Callesen H

    2003-06-01

    Full Text Available The general objective of this study was to perform follow-up studies including selected peri- and postnatal characteristics on calves born after transfer of in vitro produced (IVP embryos vitrified by the 'Open Pulled Straw' (OPS method. An overall pregnancy rate of 16% after transfer of the OPS-vitrified IVP embryos was achieved and resulted in birth of 9 calves, with 11 AI calves serving as controls. There were no immediate or long-term effects on these calves with respect to birth weight, gestation length, perinatal mortality, growth rate, disease susceptibility and reproductive performance.

  12. Repatriation of vitrified intermediate-level waste from La Hague to Gorleben; Rueckfuehrung von verglasten mittelaktiven Abfaellen von La Hague nach Gorleben

    Energy Technology Data Exchange (ETDEWEB)

    Engering, J.; Florjan, M.; Kunz, W. [GNS Gesellschaft fuer Nuklear-Service mbH, Essen (Germany); Pinson, P. [AREVA NC, Paris (France)

    2011-07-01

    Until 2005 the German nuclear power plant operators have contracts with AREVA NC (former COGEMA) and NDA (former BNFL) concerning the reprocessing of spent fuel elements. The reprocessed and vitrified radioactive waste has to be repatriated to Germany. The production of vitrified intermediate-level waste based on borosilicate glass is a CEA Marcoule technique, the CSD-B coquilles have the same dimensions as the high-level waste coquilles. The approval process at the Federal ministry for environment and reactor safety was started in 2010. In the frame of the approval procedures it was necessary to define the final repository relevant characteristics and properties of the CSD-B casks.

  13. Vitrified sperm banks: the new aseptic technique for human spermatozoa allows cryopreservation at -86 °C.

    Science.gov (United States)

    Sánchez, R; Risopatrón, J; Schulz, M; Villegas, J V; Isachenko, V; Isachenko, E

    2012-12-01

    The vitrification technique is simple, quick, cost-effective and has showed a significantly stronger cryoprotective effect in contrast to conventional freezing. The method is based on the rapid cooling of the cell by direct immersion in liquid nitrogen (LN (2) ), thereby avoiding the formation of ice crystals, due to the lower risk of water thawing, which impairs cell function. The aim of this study was to evaluate the effect of storage at -86 °C compared to the conventional -196 °C (under LN (2) ) on essential parameters of the functioning of aseptically vitrified human sperm. Sperm motility, integrity of mitochondrial membrane potential and the rate of DNA fragmentation were determined. The comparison of -86 °C and -196 °C demonstrated no statistical difference in sperm progressive motility (73% vs. 77%), integrity of mitochondrial membrane potential (71% vs. 74%) or DNA fragmentation (3.1% vs. 2.9%). In conclusion, aseptically vitrified sperm can be preserved at -86 °C; eliminating the use of LN (2) simplifies and significantly reduces the costs associated with storage in sperm banks by decreasing the time and space needed for storage, the effort in finding stored samples, and by improving safety for the operator. However, for prolonged storage further studies are needed.

  14. Effects of warming procedures on the survivability of in vitro matured buffalo (Bubalus bubalis oocytes vitrified by Cryotop

    Directory of Open Access Journals (Sweden)

    B. Gasparrini

    2010-02-01

    Full Text Available The aim of this work was to evaluate the effects of different warming procedures on the survivability of buffalo in vitro matured oocytes vitrified by the Cryotop (CT method. In vitro matured oocytes were vitrified in a final solution of 20 % ethylene glycol (EG, 20 % of dimethyl sulfoxide (DMSO and 0.5 M sucrose. In Group A oocytes (n = 111 were warmed in 1.25 M sucrose for 1 min and then exposed to decreasing concentrations of the sugar (0.625, 0.42 and 0.32 M for 30 sec. In Group B, oocytes (n =122 were warmed into a 0.25 M sucrose solution for 1 min, and then exposed to a 0.15 M sucrose solution for 5 min. Oocytes were rinsed and allocated into the in vitro maturation (IVM drops for 2 h and then fertilized in vitro. The survival rate was significantly higher in Group A compared to Group B both at 2 h post-warming (92.8 vs 83.6 %; P<0.05 and at 20 h post-warming (85.6 vs 50 %; P<0.01. Cleavage rate was also significantly increased in Group A compared to Group B (55.3 vs 36.3 %; P<0.01 whereas no differences were observed in the blastocyst yield between groups (7.8 % vs 6.9 %.

  15. Field Performance Test of an Air-Cleaner with Photocatalysis-Plasma Synergistic Reactors for Practical and Long-Term Use

    Directory of Open Access Journals (Sweden)

    Tsuyoshi Ochiai

    2014-10-01

    Full Text Available A practical and long-term usable air-cleaner based on the synergy of photocatalysis and plasma treatments has been developed. A field test of the air-cleaner was carried out in an office smoking room. The results were compared to previously reported laboratory test results. Even after a treatment of 12,000 cigarettes-worth of tobacco smoke, the air-cleaner maintained high-level air-purification activity (98.9% ± 0.1% and 88% ± 1% removal of the total suspended particulate (TSP and total volatile organic compound (TVOC concentrations, respectively at single-pass conditions. Although the removal ratio of TSP concentrations was 98.6% ± 0.2%, the ratio of TVOC concentrations was 43.8% after a treatment of 21,900 cigarettes-worth of tobacco smoke in the field test. These results indicate the importance of suitable maintenance of the reactors in the air-cleaner during field use.

  16. Plasma-surface modification vs air oxidation on carbon obtained from peach stone: Textural and chemical changes and the efficiency as adsorbents

    Science.gov (United States)

    De Velasco Maldonado, Paola S.; Hernández-Montoya, Virginia; Montes-Morán, Miguel A.

    2016-10-01

    Carbons were prepared from peach stones (Prunus persica) using different carbonization temperatures (600, 800 and 1000 °C). A selected sample was modified by oxidation using conventional oxidation techniques (thermal treatment in air atmosphere) and with cold oxygen plasma oxidation, under different conditions. Samples were characterized using elemental analysis, FT-IR spectroscopy, nitrogen adsorption isotherms at -196 °C, SEM/EDX analysis, potentiometric titration and XPS analysis. Carbons with and without oxidation were employed in the adsorption of Pb2+ in aqueous solution. Results obtained indicated that the materials with high contents of acidic oxygen groups were more efficient in the removal of Pb2+, values as high as approx. 40 mg g-1 being obtained for the best performing carbon. Textural properties of the original, un-oxidized carbon were significantly altered only after oxidation under air atmosphere at 450 °C. On the other hand, the samples oxidized with plasma show little changes in the textural parameters and a slight increase in the specific surface was observed for the sample treated at high RF power (100 W). Additionally, a significant increment of the oxygen content was observed for the plasma oxidized samples, as measured by XPS.

  17. Needle-array to Plate DBD Plasma Using Sine AC and Nanosecond Pulse Excitations for Purpose of Improving Indoor Air Quality.

    Science.gov (United States)

    Zhang, Li; Yang, Dezheng; Wang, Wenchun; Wang, Sen; Yuan, Hao; Zhao, Zilu; Sang, Chaofeng; Jia, Li

    2016-04-29

    In this study, needle-array to plate electrode configuration was employed to generate an atmospheric air diffuse discharge using both nanosecond pulse and sine AC voltage as excitation voltage for the purpose of improving indoor air quality. Different types of voltage sources and electrode configurations are employed to optimize electrical field distribution and improve discharge stability. Discharge images, electrical characteristics, optical emission spectra, and plasma gas temperatures in both sine AC discharge and nanosecond pulse discharge were compared and the discharge stability during long operating time were discussed. Compared with the discharge excited by sine AC voltage, the nanosecond pulsed discharge is more homogenous and stable, besides, the plasma gas temperature of nanosecond pulse discharge is much lower. Using packed-bed structure, where γ- Al2O3 pellets are filled in the electrode gap, has obvious efficacy in the production of homogenous discharge. Furthermore, both sine AC discharge and nanosecond pulse discharge were used for removing formaldehyde from flowing air. It shows that nanosecond pulse discharge has a significant advantage in energy cost. And the main physiochemical processes for the generation of active species and the degradation of formaldehyde were discussed.

  18. Needle-array to Plate DBD Plasma Using Sine AC and Nanosecond Pulse Excitations for Purpose of Improving Indoor Air Quality

    Science.gov (United States)

    Zhang, Li; Yang, Dezheng; Wang, Wenchun; Wang, Sen; Yuan, Hao; Zhao, Zilu; Sang, Chaofeng; Jia, Li

    2016-04-01

    In this study, needle-array to plate electrode configuration was employed to generate an atmospheric air diffuse discharge using both nanosecond pulse and sine AC voltage as excitation voltage for the purpose of improving indoor air quality. Different types of voltage sources and electrode configurations are employed to optimize electrical field distribution and improve discharge stability. Discharge images, electrical characteristics, optical emission spectra, and plasma gas temperatures in both sine AC discharge and nanosecond pulse discharge were compared and the discharge stability during long operating time were discussed. Compared with the discharge excited by sine AC voltage, the nanosecond pulsed discharge is more homogenous and stable, besides, the plasma gas temperature of nanosecond pulse discharge is much lower. Using packed-bed structure, where γ- Al2O3 pellets are filled in the electrode gap, has obvious efficacy in the production of homogenous discharge. Furthermore, both sine AC discharge and nanosecond pulse discharge were used for removing formaldehyde from flowing air. It shows that nanosecond pulse discharge has a significant advantage in energy cost. And the main physiochemical processes for the generation of active species and the degradation of formaldehyde were discussed.

  19. No peri- and postnatal effects on calves born after transfer of in vitro produced embryos vitrified by the open pulled straw (OPS) method

    DEFF Research Database (Denmark)

    Jacobsen, H.; Holm, P.; Schmidt, M.;

    2003-01-01

    -vitrified IVP embryos was achieved and resulted in birth of 9 calves, with 11 AI calves serving as controls. There were no immediate or long-term effects on these calves with respect to birth weight, gestation length, perinatal mortality, growth rate, disease susceptibility and reproductive performance....

  20. Vitrified bottom ash slag from municipal solid waste incinerators - Phase relations of CaO-SiO2-Na20 oxide system

    NARCIS (Netherlands)

    Zhang, Z.; Xiao, Y.; Yang, Y.; Boom, R.; Voncken, J.H.L.

    2009-01-01

    Vitrification is considered to be an attractive technology for bottom ash treatment because it destroys the hazardous organics, contributes to immobilization of the heavy metals, and additionally it reduces drastically the volume. The main components of the vitrified bottom ash slag are SiO2 , CaO,

  1. Vitrified bottom ash slag from municipal solid waste incinerators - Phase relations of CaO-SiO2-Na20 oxide system

    NARCIS (Netherlands)

    Zhang, Z.; Xiao, Y.; Yang, Y.; Boom, R.; Voncken, J.H.L.

    2009-01-01

    Vitrification is considered to be an attractive technology for bottom ash treatment because it destroys the hazardous organics, contributes to immobilization of the heavy metals, and additionally it reduces drastically the volume. The main components of the vitrified bottom ash slag are SiO2 , CaO,

  2. No peri- and postnatal effects on calves born after transfer of in vitro produced embryos vitrified by the open pulled straw (OPS) method

    DEFF Research Database (Denmark)

    Jacobsen, Helene; Holm, Peter; Schmidt, Mette;

    2003-01-01

    The general objective of this study was to perform follow-up studies including selected peri- and postnatal characteristics on calves born after transfer of in vitro produced (IVP) em- bryos vitrified by the ’Open Pulled Straw’ (OPS) method. An overall pregnancy rate of 16% after transfer of the ...

  3. Thermo Physical Characteristics of Vitrified Tile Polishing Waste for Use in Traditional Ceramics-An Initiative of Cgcri, Naroda Centre

    Science.gov (United States)

    Misra, S. N.; Machhoya, B. B.; Savsani, R. M.

    This paper reports the thermo physical characteristics of Vitrified tile polishing waste materials. As such growing production of vitrified tiles in the country generate large volume of this waste obtained during processing, polishing and cutting of the vitrified tiles to the tune of nearly 10-15 tonnes per day from each plant. The characteristic features of these materials are being studied and investigated to develop suitable technology for finding its gainful use especially in the traditional ceramics. It is known that ceramic as such building materials industry could be a large raw materials consumer and being heterogeneous and thus could utilize this vast quantity as the raw materials. However, the main problem would be it's firing nature as it showed thermal deformation after a particular temperature. Interestingly, the production process of most of the traditional ceramics follows a similar pattern starting from the raw materials processing up to a level of firing. Hence, to suggest suitable utility in the traditional ceramics as raw materials, it was the prime requisite that these waste must be thoroughly studied w. r. t various thermo physical characteristics to make use in this sectors. Hence, the present paper interestingly gone up to various study such as raw materials nature, particle size distribution, chemistry, XRD and DTA study for understanding typical physico chemical properties, and finally thermal properties to make it suitable for use in traditional ceramic industries. The higher fineness of the waste materials indicates its usefulness without extra grinding. The chemistry of typical sludge shows contamination from abrasive particles, sorrel cement bonding materials etc. originated from the polishing wheel and needs special precaution while suggesting use in the ceramic sectors. The firing characteristics of the sludge materials produces a foamy and spongy shapes and this could be the main guiding parameters in selecting the end use of the

  4. Antioxidant Capacity of Melatonin on Preimplantation Development of Fresh and Vitrified Rabbit Embryos: Morphological and Molecular Aspects.

    Directory of Open Access Journals (Sweden)

    Gamal M K Mehaisen

    Full Text Available Embryo cryopreservation remains an important technique to enhance the reconstitution and distribution of animal populations with high genetic merit. One of the major detrimental factors to this technique is the damage caused by oxidative stress. Melatonin is widely known as an antioxidant with multi-faceted ways to counteract the oxidative stress. In this paper, we investigated the role of melatonin in protecting rabbit embryos during preimplantation development from the potential harmful effects of oxidative stress induced by in vitro culture or vitrification. Rabbit embryos at morula stages were cultured for 2 hr with 0 or 10-3 M melatonin (C or M groups. Embryos of each group were either transferred to fresh culture media (CF and MF groups or vitrified/devitrified (CV and MV groups, then cultured in vitro for 48 hr until the blastocyst stage. The culture media were used to measure the activity of antioxidant enzymes: glutathione-s-transferase (GST and superoxide dismutase (SOD, as well as the levels of two oxidative substrates: lipid peroxidation (LPO and nitric oxide (NO. The blastocysts from each group were used to measure the expression of developmental-related genes (GJA1, POU5F1 and Nanog and oxidative-stress-response-related genes (NFE2L2, SOD1 and GPX1. The data showed that melatonin promoted significantly (P<0.05 the blastocyst rate by 17% and 12% in MF and MV groups compared to their controls (CF and CV groups. The GST and SOD activity significantly increased by the treatment of melatonin in fresh or vitrified embryos, while the levels of LPO and NO decreased (P<0.05. Additionally, melatonin considerably stimulated the relative expression of GJA1, NFE2L2 and SOD1 genes in MF and MV embryos compared to CF group. Furthermore, melatonin significantly ameliorated the reduction of POU5F1 and GPX1 expression induced by vitrification. The results obtained from the current investigation provide new and clear molecular aspects regarding the

  5. Vitrification of MSWI Fly Ash by Thermal Plasma Melting and Fate of Heavy Metals

    Institute of Scientific and Technical Information of China (English)

    倪国华; 赵鹏; 江贻满; 孟月东

    2012-01-01

    Municipal solid waste incinerator (MSWI) fly ash with high basicity (about 1.68) was vitrified in a thermal plasma melting furnace system. Through the thermal plasma treatment, the vitrified product (slag) with amorphous dark glassy structure was obtained, and the leachability of hazardous metals in slag was significantly reduced. Meanwhile, it was found that the cooling rate affects significantly the immobility of heavy metals in slag. The mass distribution of heavy metals (Zn, Cd, Cr, Pb, As, Hg) was investigated in residual products (slag, secondary residues and flue gas), in order to analyze the behavior of heavy metals in thermal plasma atmosphere. Heavy metal species with low boiling points accounting for the major fraction of their input-mass were adsorbed in secondary residues by pollution abatement devices, while those with high boiling points tended to be encapsulated in slag.

  6. 大气压空气等离子体羽的振动温度研究%Vibrational Temperature of Plasma Plume in Atmospheric Pressure Air

    Institute of Scientific and Technical Information of China (English)

    李雪辰; 常媛媛; 贾鹏英; 赵欢欢; 鲍文婷

    2013-01-01

    A tri-electrode discharge device was designed in a dielectric barrier discharge configurations to generate a fairly large volume plasma plume in atmospheric pressure air.The discharge characteristics of the plasma plume were investigated by an optical method.The discharge emission from the plasma plume was collected by a photomultiplier tube.It was found that the number of discharge pulse per cycle of the applied voltage increased with increasing the peak value of the applied voltage.The emission spectra of the plasma plume were collected by a spectrometer.The vibrational temperature was calculated by fitting the experimental data to the theoretical one.Results showed that the vibrational temperature of the plasma plume decreases with increasing the Up.Spatially resolved measurement of the vibrational temperature was also conducted on the plasma plume with the same method.Results showed that the vibrational temperature increases firstly and then decreases with increasing distance from the nozzle.The vibrational temperature reachs its maximum when the distance is 5.4 mm from the nozzle.These experimental phenomena were analyzed qualitatively based on the discharge theory.These results have important significance for the industrial applications of the plasma plume in atmospheric pressure air.%利用三电极介质阻挡放电装置,在大气压空气中产生了较大体积的等离子体羽.采用光学方法对该等离子体羽的特性进行了研究.发现随着外加电压峰值增加,每个外加电压周期的放电脉冲个数增加.通过采集等离子体羽的发射光谱,空间分辨地研究了放电等离子体羽的振动温度.结果表明等离子体羽的振动温度随着外加电压峰值的增加而减小;随着远离喷嘴的距离的增加,等离子体振动温度先增加后减小,当距离喷嘴5.4mm时振动温度达到最高值.对上述现象进行了定性分析.研究结果对大气压空气等离子体羽在杀菌消毒等领域的应用具有重要意义.

  7. Efficiency of Removing Sulfur Dioxide in the Air by Non-Thermal Plasma Along with the Application of the Magnetic Field

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The non-thermal plasma created by high voltage pulsed power supply can be used to remove sulfur dioxide in the air, but how to increase the removing efficiency is not clear. It is novel to apply the magnetic field in removing SO2 as discussed in this paper. The mechanisms of removing sulfur dioxide by non-thermal plasma along with the application of the magnetic field are analyzed, and the related factors affecting the removal efficiency, such as the magnitude of pulsed voltage, the polarity of the pulse, the layout of the discharge electrode, especially the magnetic field are experimentally investigated. It can be concluded that the purification efficiency is improved significantly by applying the magnetic field.

  8. Key insights into the reacting kinetics of atmospheric pressure plasmas using He +N2 /O2 /CO2 /H2 O/Air mixtures

    Science.gov (United States)

    Murakami, Tomoyuki

    2015-09-01

    A zero dimensional kinetic chemistry computational modeling to identify the important collisional mechanisms and the dominant species in atmospheric pressure plasmas has been developed. This modeling provides an enhanced capability to tailor wide variety of reactive intermediates/species in atmospheric pressure plasmas using He +N2 /O2 /CO2 /H2 O/Air mixtures. The influence of the gas constituent, the gas temperature and the excitation frequency (kHz-, RF-, Pulsed-working) on the complex reacting chemical kinetics is clarified. This work also focuses on the benchmarking between the predictive outputs of this computer-based simulations and the diverse experimental diagnostics with particular emphasis on reactive oxygen/nitrogen intermediates/species. This work was partly supported by KAKENHI Grant Number 24561054.

  9. Generation of large-scale, barrier-free diffuse plasmas in air at atmospheric pressure using array wire electrodes and nanosecond high-voltage pulses

    Science.gov (United States)

    Teng, Yun; Li, Lee; Liu, Yun-Long; Liu, Lun; Liu, Minghai

    2014-10-01

    This paper introduces a method to generate large-scale diffuse plasmas by using a repetition nanosecond pulse generator and a parallel array wire-electrode configuration. We investigated barrier-free diffuse plasmas produced in the open air in parallel and cross-parallel array line-line electrode configurations. We found that, when the distance between the wire-electrode pair is small, the discharges were almost extinguished. Also, glow-like diffuse plasmas with little discharge weakening were obtained in an appropriate range of line-line distances and with a cathode-grounding cross-electrode configuration. As an example, we produced a large-scale, stable diffuse plasma with volumes as large as 18 × 15 × 15 cm3, and this discharge region can be further expanded. Additionally, using optical and electrical measurements, we showed that the electron temperature was higher than the gas temperature, which was almost the same as room temperature. Also, an array of electrode configuration with more wire electrodes had helped to prevent the transition from diffuse discharge to arc discharge. Comparing the current waveforms of configurations with 1 cell and 9 cells, we found that adding cells significantly increased the conduction current and the electrical energy delivered in the electrode gaps.

  10. Characteristics of plasma induced by interaction of a free-oscillated laser pulse with a coal target in air and combustible gas

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Qiansuo; Peng, Zhimin [Laboratory of High Temperature Gas Dynamics, Institute of Mechanics, Chinese Academy of Sciences, Bei-si-huan-xi-lu No.15, Beijing 100190 (China)

    2010-05-15

    Plasma in the air is successfully induced by a free-oscillated Nd:YAG laser pulse with a peak power of 10{sup 2-3} W. The initial free electrons for the cascade breakdown process are from the ablated particles from the surface of a heated coal target, likewise induced by the focused laser beam. The laser field compensates the energy loss of the plasma when the corresponding temperature and the images are investigated by fitting the experimental spectra of B{sup 2} sum {sup +} {yields} X{sup 2} sum {sup +} band of CN radicals in the plasma with the simulated spectra and a 4-frame CCD camera. The electron density is estimated using a simplified Kramer formula. As this interaction occurs in a gas mixture of hydrogen and oxygen, the formation and development of the plasma are weakened or restrained due to the chaining branch reaction in which the OH radicals are accumulated and the laser energy is consumed. Moreover, this laser ignition will initiate the combustion or explosion process of combustible gas and the minimum ignition energy is measured at different initial pressures. The differences in the experimental results compared to those induced by a nanosecond Q-switched laser pulse with a peak power of 10{sup 6-8} W are also discussed. (author)

  11. Changes in the electro-physical properties of MCT epitaxial films affected by a plasma volume discharge induced by an avalanche beam in atmospheric-pressure air

    Science.gov (United States)

    Grigoryev, D. V.; Voitsekhovskii, A. V.; Lozovoy, K. A.; Tarasenko, V. F.; Shulepov, M. A.

    2015-11-01

    In this paper the influence of the plasma volume discharge of nanosecond duration formed in a non-uniform electric field at atmospheric pressure on samples of epitaxial films HgCdTe (MCT) films are discussed. The experimental data show that the action of pulses of nanosecond volume discharge in air at atmospheric pressure leads to changes in the electrophysical properties of MCT epitaxial films due to formation of a near-surface high- conductivity layer of the n-type conduction. The preliminary results show that it is possible to use such actions in the development of technologies for the controlled change of the properties of MCT.

  12. INTERACTION OF LASER RADIATION WITH MATTER. LASER PLASMA: Structure of flows due to interaction of CO2 laser pulse pairs with a target in air

    Science.gov (United States)

    Bakeev, A. A.; Nikolashina, L. I.; Potashkin, M. N.; Prokopenko, N. V.

    1991-06-01

    An analysis is made of two pulses from an electric-discharge CO2 laser, of 6-12 μs duration and separated in time, incident on a target surrounded by air of normal density. The main attention is concentrated on breakdown of air by the second pulse at a boundary separating the "cold gas" and the plasma generated by the first pulse ("hot gas"). A gasdynamic system of waves is then generated. It consists of an absorption wave traveling along the cold gas opposite to the laser radiation and a wave propagating along the hot gas toward the target. The best agreement between the theory and experiment is obtained employing a model in which an absorption wave travels along the hot gas in an overcompressed detonation regime. The density of the radiation flux needed to maintain such a wave is 20-30% of the average density of the laser radiation flux carried by the second pulse.

  13. Porous materials produced from incineration ash using thermal plasma technology.

    Science.gov (United States)

    Yang, Sheng-Fu; Chiu, Wen-Tung; Wang, To-Mai; Chen, Ching-Ting; Tzeng, Chin-Ching

    2014-06-01

    This study presents a novel thermal plasma melting technique for neutralizing and recycling municipal solid waste incinerator (MSWI) ash residues. MSWI ash residues were converted into water-quenched vitrified slag using plasma vitrification, which is environmentally benign. Slag is adopted as a raw material in producing porous materials for architectural and decorative applications, eliminating the problem of its disposal. Porous materials are produced using water-quenched vitrified slag with Portland cement and foaming agent. The true density, bulk density, porosity and water absorption ratio of the foamed specimens are studied here by varying the size of the slag particles, the water-to-solid ratio, and the ratio of the weights of the core materials, including the water-quenched vitrified slag and cement. The thermal conductivity and flexural strength of porous panels are also determined. The experimental results show the bulk density and the porosity of the porous materials are 0.9-1.2 g cm(-3) and 50-60%, respectively, and the pore structure has a closed form. The thermal conductivity of the porous material is 0.1946 W m(-1) K(-1). Therefore, the slag composite materials are lightweight and thermal insulators having considerable potential for building applications. Copyright © 2013 Elsevier Ltd. All rights reserved.

  14. Plasma treatment of INEL soil contaminated with heavy metals

    Energy Technology Data Exchange (ETDEWEB)

    Detering, B.A.; Batdorf, J.A.

    1992-01-01

    INEL soil spiked with inorganic salts of chromium, lead, mercury, silver, and zinc was melted in a 150 kW plasma furnace to produce a glassy slag product. This glassy slag is an environmentally safe waste form. In order to reduce the melting temperature of the soil, sodium carbonate was added to half of the test batches. Random sample from each batch of glassy slag product were analyzed by an independent laboratory for total metals concentration and leachability of metals via the Environmental Protection Agency (EPA) toxicity characterization leaching procedure (RCLP) tests. These tests showed the residual metals were very tightly bound to the slag matrix and were within EPA TCLP limits under these test conditions. Additionally, scanning electron microscopy (SEM) and emissions dispersive spectroscopy (EDS) analysis of the vitrified soil also confirmed that the added metals present in the vitrified soil were totally contained in the crystalline phase as distinct oxide crystallites.

  15. Production of extended plasma channels in atmospheric air by amplitude-modulated UV radiation of GARPUN-MTW Ti : sapphire—KrF laser. Part 2. Accumulation of plasma electrons and electric discharge control

    Science.gov (United States)

    Zvorykin, V. D.; Ionin, Andrei A.; Levchenko, A. O.; Mesyats, Gennadii A.; Seleznev, L. V.; Sinitsyn, D. V.; Smetanin, Igor V.; Sunchugasheva, E. S.; Ustinovskii, N. N.; Shutov, A. V.

    2013-04-01

    The problem of the production of extended (~1 m) plasma channels is studied in atmospheric air by amplitude-modulated laser pulses of UV radiation, which are a superposition of a subpicosecond USP train amplified in a regenerative KrF amplifier with an unstable confocal resonator and a quasi-stationary lasing pulse. The USPs possess a high (0.2-0.3 TW) peak power and efficiently ionise oxygen molecules due to multiphoton ionisation, and the quasi-stationary lasing pulse, which has a relatively long duration (~100 ns), maintains the electron density at a level ne = (3-5) × 1014 cm—3 by suppressing electron attachment to oxygen. Experiments in laser triggering of high-voltage electric discharges suggest that the use of combined pulses results in a significant lowering of the breakdown threshold and enables controlling the discharge trajectory with a higher efficiency in comparison with smooth pulses. It was shown that controlled breakdowns may develop with a delay of tens of microseconds relative to the laser pulse, which is many orders of magnitude greater than the lifetime of free electrons in the laser-induced plasma. We propose a mechanism for this breakdown, which involves speeding-up of the avalanche ionisation of the air by negative molecular oxygen ions with a low electron binding energy (~0.5 eV) and a long lifetime (~1 ms), which are produced upon cessation of the laser pulse.

  16. LASER PLASMA: Experimental confirmation of the erosion origin of pulsed low-threshold surface optical breakdown of air

    Science.gov (United States)

    Min'ko, L. Ya; Chumakou, A. N.; Chivel', Yu A.

    1988-08-01

    Nanosecond kinetic spectroscopy techniques were used to identify the erosion origin of pulsed low-threshold surface optical breakdown of air as a result of interaction of microsecond neodymium and CO2 laser pulses with some metals (indium, lead).

  17. DBD Plasma Actuators for Flow Control in Air Vehicles and Jet Engines - Simulation of Flight Conditions in Test Chambers by Density Matching

    Science.gov (United States)

    Ashpis, David E.; Thurman, Douglas R.

    2011-01-01

    Dielectric Barrier Discharge (DBD) Plasma actuators for active flow control in aircraft and jet engines need to be tested in the laboratory to characterize their performance at flight operating conditions. DBD plasma actuators generate a wall-jet electronically by creating weakly ionized plasma, therefore their performance is affected by gas discharge properties, which, in turn, depend on the pressure and temperature at the actuator placement location. Characterization of actuators is initially performed in a laboratory chamber without external flow. The pressure and temperature at the actuator flight operation conditions need to be simultaneously set in the chamber. A simplified approach is desired. It is assumed that the plasma discharge depends only on the gas density, while other temperature effects are assumed to be negligible. Therefore, tests can be performed at room temperature with chamber pressure set to yield the same density as in operating flight conditions. The needed chamber pressures are shown for altitude flight of an air vehicle and for jet engines at sea-level takeoff and altitude cruise conditions. Atmospheric flight conditions are calculated from standard atmosphere with and without shock waves. The engine data was obtained from four generic engine models; 300-, 150-, and 50-passenger (PAX) aircraft engines, and a military jet-fighter engine. The static and total pressure, temperature, and density distributions along the engine were calculated for sea-level takeoff and for altitude cruise conditions. The corresponding chamber pressures needed to test the actuators were calculated. The results show that, to simulate engine component flows at in-flight conditions, plasma actuator should be tested over a wide range of pressures. For the four model engines the range is from 12.4 to 0.03 atm, depending on the placement of the actuator in the engine. For example, if a DBD plasma actuator is to be placed at the compressor exit of a 300 PAX engine, it

  18. Plasma induced degradation of Indigo Carmine by bipolar pulsed dielectric barrier discharge(DBD) in the water-air mixture

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ruo-bing; WU Yan; LI Guo-feng; WANG Ning-hui; LI Jie

    2004-01-01

    Degradation of the Indigo Carmine(IC) by the bipolar pulsed DBD in water-air mixture was studied. Effects of various parameters such as gas flow rate, solution conductivity, pulse repetitive rate and ect., on color removal efficiency of dying wastewater were investigated. Concentrations of gas phase O3 and aqueous phase H2O2 under various conditions were measured. Experimental results showed that air bubbling facilitates the breakdown of water and promotes generation of chemically active species. Color removal efficiency of IC solution can be greatly improved by the air aeration under various solution conductivities. Decolorization efficiency increases with the increase of the gas flow rate, and decreases with the increase of the initial solution conductivity. A higher pulse repetitive rate and a larger pulse capacitor Cp are favorable for the decolorization process. Ozone and hydrogen peroxide formed decreases with the increase of initial solution conductivity. In addition, preliminary analysis of the decolorization mechanisms is given.

  19. Direct dynamic synthesis of nanodispersed phases of titanium oxides upon sputtering of electrodischarge titanium plasma into an air atmosphere

    Science.gov (United States)

    Sivkov, A. A.; Gerasimov, D. Yu.; Nikitin, D. S.

    2017-01-01

    Experimental investigations of the possibility of directly synthesizing nanodispersed crystalline phases of titanium dioxides with rutile and anatase structures in a hypervelocity jet of electroerosion plasma generated by a coaxial magnetoplasma accelerator with titanium electrodes are presented. A powder product containing nanosized polymorphic phases of titanium dioxide with a spherical shape of particles has been manufactured.

  20. Effect of active species on animal cells in culture media induced by DBD Plasma irradiation using air

    Science.gov (United States)

    Ohtsubo, Tetsuya; Ono, Reoto; Hayashi, Nobuya

    2015-09-01

    Little has been reported on action mechanism of active species produced by plasmas affecting living cells. In this study, active species in culture medium generated by torch type DBD and variations of animal cells are attempted to be clarified. Animal cells are irradiated by DBD plasma through various media such as DMEM, PBS and distilled water. Irradiation period is 1 to 15 min. The distance between the lower tip of plasma touch and the surface of the medium is 10 mm. Concentrations of NO2 -, O2 in liquid are measured. After the irradiation, the cells were cultivated in culture medium and their modifications are observed by microscope and some chemical reagents. Concentration of NO2 - and H2 O2 in all media increased with discharge period. Increase rate of NO2 -concentration is much higher than that of hydrogen peroxide. After plasma irradiation for 15 min, concentrations of NO2 were 80 mg/L in DMEM, 30 mg/L in PBS and 15 mg/L in distilled water. Also, the concentration of H2 O2 became 3mg/L in DMEM, 6.5 mg/L in PBS and 6.5mg/L in distilled water. The significant inactivation of cells was observed in the PBS. Above results indicate that, in this experiment, H2 O2 or OH radicals would affect animal cells in culture media.

  1. Comparison of vitrified and unvitrified Eocene woody tissues by TMAH thermochemolysis – implications for the early stages of the formation of vitrinite

    Directory of Open Access Journals (Sweden)

    Huggett William W

    2006-10-01

    Full Text Available Abstract Samples of vitrified and unvitrified Eocene woody plant tissues collected from the Fossil Forest site, Geodetic Hills, Axel Heiberg Island, have been characterized by TMAH thermochemolysis. All samples are gymnosperm-derived, are of very low maturity and all share the same post-depositional geologic history. Differences in the distributions of products observed from vitrified and unvitrified samples suggest that vitrification of woody tissue is associated with modification of the lignin C3 side chain, following loss of all or most of the carbohydrate present in the precursor woody tissues. The key driver of vitrification appears to be physical compression of the tissue following biological removal of cellulosic materials.

  2. How does vitrification affect oocyte viability in oocyte donation cycles? A prospective study to compare outcomes achieved with fresh versus vitrified sibling oocytes.

    Science.gov (United States)

    Solé, M; Santaló, J; Boada, M; Clua, E; Rodríguez, I; Martínez, F; Coroleu, B; Barri, P N; Veiga, A

    2013-08-01

    How does vitrification affect oocyte viability? Vitrification does not affect oocyte viability in oocyte donation cycles. Oocyte vitrification is performed routinely and successfully in IVF and oocyte donation programs. This is a prospective study performed between June 2009 and February 2012 to compare ongoing pregnancy rates and other indices of viability between fresh and vitrified oocytes. A total of 99 donations with more than 16 oocytes (MII) in which oocytes were allocated both to a synchronous recipient (fresh oocytes) and to an asynchronous recipient (vitrified oocytes) were included. The participants were consenting couples (donors and recipients) from the oocyte donation program. On the day of retrieval, the oocytes allocated to the synchronous recipient were inseminated and those allocated for banking were denuded of cumulus and vitrified. Vitrified oocytes were microinjected with spermatozoa 2 h after warming. Embryo transfer was performed on Day 2 of development in both groups, and the remaining embryos were cryopreserved on Day 3. Clinical pregnancy was defined by a positive fetal heartbeat at 6 weeks. A total of 989 oocytes were warmed and 85.6% survived. No significant differences were observed between fresh and vitrified oocytes: fertilization rate (80.7 versus 78.2%), ongoing embryo rate (71.0 versus 68.2%) or good-quality embryo rate (54.1 versus 49.8%). The mean number of embryos transferred was similar in both groups (1.82 ± 0.44 versus 1.90 ± 0.34). The implantation rate (33.3 versus 34.0%) and the multiple pregnancy rate (27.7 versus 20.8) were also similar between both groups (P > 0.05). The live birth rate per cycle was 38.4% in the recipients of fresh oocytes and 43.4% in the recipients of vitrified oocytes (P > 0.05). Eighty five frozen embryo transfers were also evaluated. Comparing embryos from fresh and vitrified oocytes there were no significant differences in the embryo survival rate (70.1 versus 65.8%), clinical pregnancy rate

  3. Shielding calculations with SCALE/MAVRIC and comparison with measurements for the TN85 cask with vitrified high level radioactive waste

    Science.gov (United States)

    Thiele, Holger; Börst, Frank-Michael

    2017-09-01

    A series of dose rate/spectra measurements in the German interim storage facility Gorleben was carried out at a TN85 cask in April 2009. This type of cask is used for the transport and interim storage of vitrified high level radioactive waste (HAW) from reprocessing. The aim of this work is to assess the shielding component MAVRIC of the SCALE code system with these measurements for the use in the German Bundesamt für Kerntechnische Entsorgungssicherheit (BfE).

  4. 玻化微珠保温砂浆的碳化试验研究%Research on Carbonization Test of Vitrified Microsphere Thermal Insulation Mortar

    Institute of Scientific and Technical Information of China (English)

    薛若璞; 余以明; 袁新顺; 徐建雄

    2016-01-01

    By accelerated carbonation test,mixing 18%~20% of lime to the special effects and functions of vitrified microsphere thermal insulation mortar were analyzed.The use of calcium hydroxide producing calcium carbonate crys-tals to increase the density and intensity of vitrified microsphere thermal insulation mortar,the concentration of carbon dioxide must be controlled.Low carbon dioxide concentration was conductive to the growth of calcium carbonate crystal which could be packed by cement hydration product to densify the structure of vitrified microsphere thermal mortar,ul-timately the favorable carbon dioxide concentrations were determined to be 2%.%通过加速碳化试验,分析掺入18%~20%的石灰对玻化微珠保温砂浆的特殊影响与作用。要利用氢氧化钙的碳化生成碳酸钙晶体来提高玻化微珠保温砂浆的致密度和强度,必须控制二氧化碳的浓度,低二氧化碳浓度有利于生长的碳酸钙晶体被水泥水化产物包裹从而促使玻化微珠保温砂浆结构致密化,最终确定有利的二氧化碳浓度为2%。

  5. Developmental Competence of Vitrified-Warmed Bovine Oocytes at the Germinal-Vesicle Stage is Improved by Cyclic Adenosine Monophosphate Modulators during In Vitro Maturation.

    Directory of Open Access Journals (Sweden)

    Kenji Ezoe

    Full Text Available Cryopreservation of mature oocytes and embryos has provided numerous benefits in reproductive medicine. Although successful cryopreservation of germinal-vesicle stage (GV oocytes holds promise for further advances in reproductive biology and clinical embryology fields, reports regarding cryopreservation of immature oocytes are limited. Oocyte survival and maturation rates have improved since vitrification is being performed at the GV stage, but the subsequent developmental competence of GV oocytes is still low. The purpose of this study was to evaluate the effects of supplementation of the maturation medium with cyclic adenosine monophosphate (cAMP modulators on the developmental competence of vitrified-warmed GV bovine oocytes. GV oocytes were vitrified-warmed and cultured to allow for oocyte maturation, and then parthenogenetically activated or fertilized in vitro. Our results indicate that addition of a cAMP modulator forskolin (FSK or 3-isobutyl-1-methylxanthine (IBMX to the maturation medium significantly improved the developmental competence of vitrified-warmed GV oocytes. We also demonstrated that vitrification of GV oocytes led to a decline in cAMP levels and maturation-promoting factor (MPF activity in the oocytes during the initial and final phases of maturation, respectively. Nevertheless, the addition of FSK or IBMX to the maturation medium significantly elevated cAMP levels and MPF activity during IVM. Taken together, our results suggest that the cryopreservation-associated meiotic and developmental abnormalities observed in GV oocytes may be ameliorated by an artificial increase in cAMP levels during maturation culture after warming.

  6. Improvement of mechanical properties of polylactic acid adhesion joints with bio-based adhesives by using air atmospheric plasma treatment

    OpenAIRE

    Jordá Vilaplana, Amparo; Sánchez Nacher, Lourdes; Fombuena Borrás, Vicent; García García, Daniel; Carbonell Verdú, Alfredo

    2015-01-01

    The packaging industry generates a high volume of wastes; so that, there is a high demand of biodegradable materials, which do not damage the environment. Nowadays, there is an interesting consumption of polylactic acid (PLA) due to its biodegradable features. This work focuses on the improvement of mechanical properties of PLA adhesion joints for uses in the packaging industry. In order to achieve that purpose, atmospheric plasma treatment is used to selectively modify PLA surface properties...

  7. Mathematical simulation of ignition of a coal-dust suspension in air by a low-temperature plasma jet

    Science.gov (United States)

    Rychkov, A. D.; Zhukov, M. F.

    1998-05-01

    The process of aerosuspension ignition of a suspension in air in a pulverized-coal burner with a preswitched muffle by a central axisymmetric air stream heated in an electric-arc plasmatron to a temperature of about ≈5000 K is numerically simulated. This process is the basis of a new fuel-oil-free method of ignition of the boilers of thermal power stations. The method is rather promising from the viewpoint of both economy and ecology. The goal of numerical simulation is to study the process of ignition of coal particles in the flow and to identify the conditions necessary for the transition to self-sustained burning of a coal-dust mixture. The results obtained revealed the significant role of radiative heat transfer in initializing the burning process of solid fuel particles.

  8. Laboratory Testing of Bulk Vitrified Low-Activity Waste Forms to Support the 2005 Integrated Disposal Facility Performance Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Pierce, Eric M.; McGrail, B. Peter; Bagaasen, Larry M.; Rodriguez, Elsa A.; Wellman, Dawn M.; Geiszler, Keith N.; Baum, Steven R.; Reed, Lunde R.; Crum, Jarrod V.; Schaef, Herbert T.

    2006-06-30

    The purpose of this report is to document the results from laboratory testing of the bulk vitri-fied (BV) waste form that was conducted in support of the 2005 integrated disposal facility (IDF) performance assessment (PA). Laboratory testing provides a majority of the key input data re-quired to assess the long-term performance of the BV waste package with the STORM code. Test data from three principal methods, as described by McGrail et al. (2000a; 2003a), are dis-cussed in this testing report including the single-pass flow-through test (SPFT) and product con-sistency test (PCT). Each of these test methods focuses on different aspects of the glass corrosion process. See McGrail et al. (2000a; 2003a) for additional details regarding these test methods and their use in evaluating long-term glass performance. In addition to evaluating the long-term glass performance, this report discusses the results and methods used to provided a recommended best estimate of the soluble fraction of 99Tc that can be leached from the engineer-ing-scale BV waste package. These laboratory tests are part of a continuum of testing that is aimed at improving the performance of the BV waste package.

  9. Laboratory Testing of Bulk Vitrified Low-Activity Waste Forms to Support the 2005 Integrated Disposal Facility Performance Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Pierce, Eric M.; McGrail, B. Peter; Bagaasen, Larry M.; Rodriguez, Elsa A.; Wellman, Dawn M.; Geiszler, Keith N.; Baum, Steven R.; Reed, Lunde R.; Crum, Jarrod V.; Schaef, Herbert T.

    2005-03-31

    The purpose of this report is to document the results from laboratory testing of the bulk vitri-fied (BV) waste form that was conducted in support of the 2005 integrated disposal facility (IDF) performance assessment (PA). Laboratory testing provides a majority of the key input data re-quired to assess the long-term performance of the BV waste package with the STORM code. Test data from three principal methods, as described by McGrail et al. (2000a; 2003a), are dis-cussed in this testing report including the single-pass flow-through test (SPFT) and product con-sistency test (PCT). Each of these test methods focuses on different aspects of the glass corrosion process. See McGrail et al. (2000a; 2003a) for additional details regarding these test methods and their use in evaluating long-term glass performance. In addition to evaluating the long-term glass performance, this report discusses the results and methods used to provided a recommended best estimate of the soluble fraction of 99Tc that can be leached from the engineer-ing-scale BV waste package. These laboratory tests are part of a continuum of testing that is aimed at improving the performance of the BV waste package.

  10. Ultrastructural Changes and Methylation of Human Oocytes Vitrified at the Germinal Vesicle Stage and Matured in vitro after Thawing.

    Science.gov (United States)

    Liu, Ming-Hui; Zhou, Wen-Hui; Chu, Da-Peng; Fu, Lei; Sha, Wei; Li, Yuan

    2017-01-01

    The study aimed to assess the effect of in vitro vitrification and maturation on the nuclear configuration, cytoplasmic maturation and global DNA methylation pattern of human germinal vesicle (GV) stage oocytes. Human oocytes from infertile women were randomly assigned to one of 3 groups: (i) metaphase II (MII) oocytes matured in vivo (vivo-MII, n = 56) as controls; (ii) MII oocytes matured in vitro (vitro-MII, n = 106); and (iii) MII oocytes that were vitrified at the GV stage, warmed and matured in vitro (cryo-MII, n = 122). All MII oocytes were fixed and immunofluorescence staining for spindle, chromosome, mitochondrion and cortical granules (CGs) were performed; examination was done using immunofluorescence laser scanning confocal microscope. The expression of 5-methycytosine in these MII oocytes was also assessed. No significant difference was observed between vitro-MII and cryo-MII groups with respect to oocyte maturation rate (72.4 vs. 78.3%). No significant differences were observed in the distribution of mitochondria, migration of CG and global DNA methylation pattern among the 3 study groups. However, the abnormal configuration of spindle and chromosome was significantly higher in cryo-MII group (78.9 and 84.2%) as compared to that in the vitro-MII (45.0 and 50.0%, p vitro maturation could affect the organization of spindle and chromosome. © 2016 S. Karger AG, Basel.

  11. Enhanced near infrared emission from the partially vitrified Nd{sup 3+} and silver co-doped zeolite Y

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Hui, E-mail: linh8112@163.com, E-mail: fujii@eedept.kobe-u.ac.jp; Chu Rong Gui, Sa; Imakita, Kenji; Fujii, Minoru, E-mail: linh8112@163.com, E-mail: fujii@eedept.kobe-u.ac.jp [Department of Electrical and Electronic Engineering, Graduate School of Engineering, Kobe University, Rokkodai, Nada, Kobe 657-8501 (Japan)

    2014-01-21

    Near infrared (NIR) emission from the Nd{sup 3+} doped zeolite Y was strongly enhanced by partially vitrifying the zeolite structure via extra loading silver ions and post annealing. Under the low annealing temperatures at 450 °C and 650 °C, the states of the loaded silver were determined to be the co-existence of the isolated Ag{sup 0} atoms, the Ag{sup +} ions, and the Ag{sub 2}{sup +} dimers. However, there was no enhancement in the NIR emission by the introduction of these small silver clusters. Under higher annealing temperature at 900 °C where the lattice of the zeolite Y was partially collapsed into the amorphous phase, strong NIR emission enhancement at 1064 nm with a factor of 6.8 was observed. The partial vitrification process by the co-loading of silver and post heat-treatment had strong effect on eliminating the H{sub 2}O molecules, which can greatly enhance the NIR emission.

  12. Nonhomogeneous surface properties of parylene-C film etched by an atmospheric pressure He/O2 micro-plasma jet in ambient air

    Science.gov (United States)

    Wang, Tao; Yang, Bin; Chen, Xiang; Wang, Xiaolin; Yang, Chunsheng; Liu, Jingquan

    2016-10-01

    Surface properties of parylene-C film etched by an atmospheric pressure He/O2 micro-plasma jet in ambient air were investigated. The morphologies and chemical compositions of the etched surface were analyzed by optical microscopy, SEM, EDS, XPS and ATR-FTIR. The microscopy and SEM images showed the etched surface was nonhomogeneous with six discernable ring patterns from the center to the outside domain, which were composed of (I) a central region; (II) an effective etching region, where almost all of the parylene-C film was removed by the plasma jet with only a little residual parylene-C being functionalized with carboxyl groups (Cdbnd O, Osbnd Cdbnd O-); (III) an inner etching boundary; (IV) a middle etching region, where the film surface was smooth and partially removed; (V) an outer etching boundary, where the surface was decorated with clusters of debris, and (VI) a pristine parylene-C film region. The analysis of the different morphologies and chemical compositions illustrated the different localized etching process in the distinct regions. Besides, the influence of O2 flow rate on the surface properties of the etched parylene-C film was also investigated. Higher volume of O2 tended to weaken the nonhomogeneous characteristics of the etched surface and improve the etched surface quality.

  13. Investigating the momentum balance of a plasma pinch: An air-side stereoscopic imaging system for locating probes

    Energy Technology Data Exchange (ETDEWEB)

    Sears, Jason, E-mail: jason.sears@alum.mit.edu; Intrator, T. P.; Feng, Y.; Swan, H. O.; Klarenbeek, J.; Gao, K. [Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, New Mexico 87545 (United States)

    2014-10-01

    The momentum balance of a plasma pinch in the Reconnection Scaling Experiment (RSX) is examined in three dimensions using several repositionable, insertable probes. A new camera-based system described here triangulates the locations of the probe tips so that their measurements are spatially registered. The optical system locates probes to within ±1.5 mm of their absolute 3D position in the vessel and to within ±0.7 mm relative to other probes, on the order of the electron inertial length (1–2 mm)

  14. Influence of Heat Treatment on the Bond Coat Cyclic Oxidation Behaviour in an Air-plasma-sprayed Thermal Barrier Coating System

    Institute of Scientific and Technical Information of China (English)

    W.R. Chen; X. Wu; B.R. Marple; P.C. Patnaik

    2004-01-01

    It is generally believed that a thermally grown oxide (TGO) layer of alumina provides enhanced protection to the metallic bond coat in thermal barrier coating (TBC) systems at elevated temperatures. However, in an air-plasma-sprayed (APS) TBC system with Co-32Ni-21Cr-8A1-0.5Y (wt%) bond coat, the TGO layer formed upon thermal exposure in air was predominantly chromia and spinels, which would not effectively protect the bond coat at above 1000℃. In addition,mixed oxides of chromia, spinel and nickel oxide formed heterogeneously between the ceramic coating and CoNiCrAlY bond coat, which would promote crack initiation and lead to premature TBC failure. A heat treatment in a low-pressure condition was applied to the as-sprayed TBC system, with the aim to produce an alumina layer as well as reduce the amount of detrimental oxides. The influence of this low-pressure oxidation treatment (LPOT) on the bond coat cyclic oxidation behaviour of the TBC system was also investigated.

  15. Influence of Heat Treatment on the Bond Coat Cyclic Oxidation Behaviour in an Air-plasma-sprayed Thermal Barrier Coating System

    Institute of Scientific and Technical Information of China (English)

    W.R.Chen; X.Wu; B.R.Marple; P.C.Patnaik

    2004-01-01

    It is generally believed that a thermally grown oxide (TGO) layer of alumina provides enhanced protection to the metallic bond coat in thermal barrier coating (TBC) systems at elevated temperatures. However, in an air-plasma-sprayed (APS) TBC system with Co-32Ni-21Cr-8A1-0.5Y (wt%) bond coat, the TGO layer formed upon thermal exposure in air was predominantly chromia and spinels, which would not effectively protect the bond coat at above 1000℃. In addition, mixed oxides of chromia, spinel and nickel oxide formed heterogeneously between the ceramic coating and CoNiCrA1Y bond coat, which would promote crack initiation and lead to premature TBC failure. A heat treatment in a low-pressure condition was applied to the as-sprayed TBC system, with the aim to produce an alumina layer as well as reduce the amount of detrimental oxides. The influence of this low-pressure oxidation treatment (LPOT) on the bond coat cyclic oxidation behaviour of the TBC system was also investigated.

  16. Numerical modeling for investigating the optical breakdown threshold of laser-induced air plasmas at different laser characteristics

    Science.gov (United States)

    Hamam, Kholoud A.; Gaabour, Laila H.; Gamal, Yosr E. E. D.

    2017-07-01

    In this work, we report a numerical investigation of two sets of experimental measurements that were previously carried out to study the breakdown threshold dependence on laser characteristics (wavelength, pulse width, and spot size) in the breakdown of laboratory air at different pressures. The study aimed to inspect the significance of the physical mechanisms in air breakdown as related to the applied experimental conditions. In doing so, we adopted a simple theoretical formulation relying on the numerical solution of a rate equation that describes the growth of electron density due to the joined effect of multi-photon and avalanche ionization processes given in our earlier work [Gaabour et al., J. Mod. Phys. 3, 1683-1691 (2012)]. Here, the rate equation is adapted to include the effect of electron loss due to attachment processes. This equation is then solved numerically using the Runge-Kutta fourth order technique. The influence of electron gain and loss processes on the breakdown threshold is studied by calculating the breakdown threshold intensity and RMS electric field for atmospheric air using different laser parameters (wavelength, pulse widths, and focal length lenses), in correspondence to the experimental conditions given by Tambay and Thareja [J. Appl. Phys. 70(5), 2890 (1991)]. To validate the model, a comparison is made between those calculated thresholds and the experimentally measured ones. Moreover, the effective contribution of each of the considered physical processes to the breakdown phenomenon is examined by studying the effect of laser wavelength and spot diameter on the threshold intensities, as well as on the temporal variation of the electron density. The correlation between the threshold intensity and gas pressure is tested in relation to the measurements of Tambay et al. [Pramana-J. Phys. 37(2), 163 (1991)]. Calculations are also carried out to depict the impact of pulse width on the threshold intensity.

  17. Diagnóstico y cinética de plasmas de NxOy y aire a baja presión. Aplicaciones atmosféricas

    Science.gov (United States)

    Tanarro Onrubia, Isabel

    Los procesos cinéticos que tienen lugar en plasmas de óxidos de nitrógeno y de aire presentan relevancia en diferentes campos de investigación como son los relativos al control de contaminantes atmosféricos emitidos en procesos de combustión, a su formación en las superficies de las naves supersónicas y los vehículos espaciales al entrar en la atmósfera, o a su presencia en la ionosfera terrestre. En general, los fenómenos que tienen lugar en sistemas tan alejados del equilibrio termodinámico como los plasmas luminiscentes, son capaces de originar determinadas especies intermedias y productos finales de reacción a temperaturas y presiones mucho menores que las de otros procedimientos físico-químicos; y hacen posible reproducir y caracterizar en laboratorio ciertas especies inestables y mecanismos primordiales de la alta atmósfera. Por otra parte, las técnicas de resolución temporal aplicadas a plasmas modulados en amplitud resultan notablemente más sensibles que las medidas estacionarias para estimar la relevancia de los distintos mecanismos elementales o incluso para determinar sus constantes de velocidad. En este trabajo se presenta un estudio espectroscópico y espectrométrico comparativo de plasmas de óxidos de nitrógeno y de aire a baja presión (0.001-1 mbar) generados en descargas de cátodo hueco continuas o moduladas, y se propone un modelo cinético único y relativamente sencillo, que explica satisfactoriamente los comportamientos observados en todos ellos. Dicho modelo se basa en la resolución de un sistema de ecuaciones diferenciales dependientes del tiempo, que incluye los mecanismos elementales de disociación e ionización de los precursores y los productos, reacciones homogéneas entre especies atómicas, iónicas y moleculares, y reacciones heterogéneas. Al abordar estos sistemas, se constata una gran carencia de datos experimentales o teóricos sobre secciones eficaces o constantes de velocidad para las reacciones de

  18. Marshall N. Rosenbluth Outstanding Doctoral Thesis Award Talk: The Ultrafast Nonlinear Response of Air Molecules and its Effect on Femtosecond Laser Plasma Filaments in Atmosphere

    Science.gov (United States)

    Chen, Yu-Hsin

    2012-10-01

    When exceeding the critical power Pcr, an intense laser pulse propagating in a gas collapses into one or multiple ``filaments,'' which can extend meters in length with weakly ionized plasma and local intensity ˜ 10^13 W/cm^2 radially confined in a diameter of < 100 μm [1]. While it has been generally accepted the nonlinear self-focusing of the laser pulse leading to beam collapse is stabilized by plasma generation [2], neither the field-induced nonlinearity nor the plasma generation had been directly measured. This uncertainty has given rise to recent controversy about whether plasma generation does indeed counteract the positive nonlinearity [3, 4]. For even a basic understanding of femtosecond filamentation and for applications, the focusing and defocusing mechanisms---nonlinear self-focusing and ionization---must be understood. By employing a single-shot, time-resolved technique based on spectral interferometry [5] to study the constituents of air, it is found that the rotational responses in O2 and N2 are the dominant nonlinear effect in filamentary propagation when the laser pulse duration is longer than ˜ 100fs. Furthermore, we find that the instantaneous nonlinearity scales linearly up to the ionization threshold [6], eliminating any possibility of an ionization-free negative stabilization [3] of filamentation. This is confirmed by space-resolved electron density measurements in meter-long filaments produced with different pulse durations, using optical interferometry with a grazing-incidence, ps-delayed probe [7].[4pt] [1] A. Braun et al., Opt. Lett. 20, 73 (1995).[0pt] [2] A. Couairon and A. Mysyrowicz, Phys. Rep. 441, 47 (2007).[0pt] [3] V. Loriot et al., Opt. Express 17, 13429 (2009).[0pt] [4] P. B'ejot et al., Phys. Rev. Lett. 104, 103903 (2010).[0pt] [5] Y.-H. Chen et al., Opt. Express 15, 7458 (2007); Opt. Express 15, 11341 (2007).[0pt] [6] J. K. Wahlstrand et al., Phys. Rev. Lett. 107, 103901 (2011).[0pt] [7] Y.-H. Chen et al., Phys. Rev. Lett

  19. Basic data of ions in He-air mixtures for fluid modeling of low temperature plasma jets

    Energy Technology Data Exchange (ETDEWEB)

    Yousfi, M.; Benhenni, M.; Eichwald, O.; Merbahi, N. [University of Toulouse, Laplace, UMR CNRS 5213, UPS, 118 Route de Narbonne, 31062 Toulouse (France); Hennad, A. [University of Sciences and Technology of Oran Mohamed Boudiaf, USTO-MB, ETT-LMSE, BP 1505 El M' Naouer, 31000 Oran (Algeria)

    2012-08-15

    The basic ion data such as interaction potential parameters, elastic and inelastic collision cross sections, transport coefficients (reduced mobility and diffusion coefficients) and reaction coefficients have been analysed and determined for the case of He{sup +}, N{sub 2}{sup +}, and O{sub 2}{sup +} in He-dry air mixtures. The ion transport and reaction coefficients have been determined from an optimized Monte Carlo simulation using calculated elastic and experimentally fitted inelastic collision cross sections. The elastic momentum transfer cross sections have been calculated from a semi-classical JWKB (Jeffreys Wentzel Kramers Brillouin) approximation based on a (6-4) rigid core interaction potential model. The inelastic cross sections have been fitted using the measured reaction coefficients, such as, for instance, the non resonant charge transfer coefficients. The cross section sets involving elastic and inelastic processes were then validated using either the measured reduced mobility whenever available in the literature or the zero-field mobility calculated from Satoh's relation, and potential parameters available in the literature. From the sets of elastic and inelastic collision cross sections thus obtained for the first time for He{sup +}/N{sub 2}, He{sup +}/O{sub 2}, N{sub 2}{sup +}/He, and O{sub 2}{sup +}/He systems, the ion transport and reaction coefficients were calculated in the pure gases over a wide range of the density reduced electric field E/N. Then, from the present cross section and other literature sets, the ion mobility and the longitudinal and transverse diffusion coefficients were calculated for different concentrations of air in He in the case of He{sup +}, N{sub 2}{sup +}, O{sub 2}{sup +}, and also O{sup -} ions.

  20. Membrane lipid profile monitored by mass spectrometry detected differences between fresh and vitrified in vitro-produced bovine embryos.

    Science.gov (United States)

    Leão, Beatriz C S; Rocha-Frigoni, Nathália A S; Cabral, Elaine C; Franco, Marcos F; Ferreira, Christina R; Eberlin, Marcos N; Filgueiras, Paulo R; Mingoti, Gisele Z

    2015-10-01

    This study aimed to evaluate the impact of vitrification on membrane lipid profile obtained by mass spectrometry (MS) of in vitro-produced bovine embryos. Matrix-assisted laser desorption ionization-mass spectrometry (MALDI-MS) has been used to obtain individual embryo membrane lipid profiles. Due to conditions of analysis, mainly membrane lipids, most favorably phosphatidylcholines (PCs) and sphingomyelins (SMs) have been detected. The following ions described by their mass-to-charge ratio (m/z) and respective attribution presented increased relative abundance (1.2-20×) in the vitrified group: 703.5 [SM (16:0) + H]+; 722.5 [PC (40:3) + Na]+; 758.5 [PC (34:2) + H]+; 762.5 [PC (34:0) + H]+; 790.5 [PC (36:0) + H]+ and 810.5 [PC (38:4) + H]+ and/or [PC (36:1) + Na]+. The ion with a m/z 744.5 [PCp (34:1) and/or PCe (34:2)] was 3.4-fold more abundant in the fresh group. Interestingly, ions with m/z 722.5 or 744.5 indicate the presence of lipid species, which are more resistant to enzymatic degradation as they contain fatty acyl residues linked through ether type bonds (alkyl ether or plasmalogens, indicated by the lowercase 'e' and 'p', respectively) to the glycerol structure. The results indicate that cryopreservation impacts the membrane lipid profile, and that these alterations can be properly monitored by MALDI-MS. Membrane lipids can therefore be evaluated by MALDI-MS to monitor the effect of cryopreservation on membrane lipids, and to investigate changes in lipid profile that may reflect the metabolic response to the cryopreservation stress or changes in the environmental conditions.

  1. Influence of bacteria on lanthanide and actinide transfer from specific soil components (humus, soil minerals and vitrified municipal solid waste incinerator bottom ash) to corn plants: Sr-Nd isotope evidence

    Energy Technology Data Exchange (ETDEWEB)

    Aouad, Georges [Ecole et Observatoire des Sciences de la Terre, Centre de Geochimie de la Surface/CNRS UMR 7517, 1 rue Blessig, 67084 Strasbourg Cedex (France); Stille, Peter [Ecole et Observatoire des Sciences de la Terre, Centre de Geochimie de la Surface/CNRS UMR 7517, 1 rue Blessig, 67084 Strasbourg Cedex (France)]. E-mail: pstille@illite.u-strasbg.fr; Crovisier, Jean-Louis [Ecole et Observatoire des Sciences de la Terre, Centre de Geochimie de la Surface/CNRS UMR 7517, 1 rue Blessig, 67084 Strasbourg Cedex (France); Geoffroy, Valerie A. [UMR 7156 Universite Louis-Pasteur/CNRS, Genetique Moleculaire, Genomique Microbiologie, Departement Micro-organisme, Genomes, Environnement, 28 rue Goethe, 67083 Strasbourg Cedex (France); Meyer, Jean-Marie [UMR 7156 Universite Louis-Pasteur/CNRS, Genetique Moleculaire, Genomique Microbiologie, Departement Micro-organisme, Genomes, Environnement, 28 rue Goethe, 67083 Strasbourg Cedex (France); Lahd-Geagea, Majdi [Ecole et Observatoire des Sciences de la Terre, Centre de Geochimie de la Surface/CNRS UMR 7517, 1 rue Blessig, 67084 Strasbourg Cedex (France)

    2006-11-01

    Experiments have been performed to test the stability of vitrified municipal solid waste (MSW) incinerator bottom ash under the presence of bacteria (Pseudomonas aeruginosa) and plants (corn). The substratum used for the plant growth was a humus-rich soil mixed with vitrified waste. For the first time, information on the stability of waste glasses in the presence of bacteria and plants is given. Results show that inoculated plant samples contained always about two times higher lanthanide and actinide element concentrations. Bacteria support the element transfer since plants growing in inoculated environment developed a smaller root system but have higher trace element concentrations. Compared with the substratum, plants are light rare earth element (LREE) enriched. The vitrified bottom ash has to some extent been corroded by bacteria and plant activities as indicated by the presence of Nd (REE) and Sr from the vitrified waste in the plants. {sup 87}Sr/{sup 86}Sr and {sup 143}Nd/{sup 144}Nd isotope ratios of plants and soil components allow the identification of the corroded soil components and confirm that bacteria accelerate the assimilation of elements from the vitrified bottom ash. These findings are of importance for landfill disposal scenarios, and similar experiments should be performed in order to better constrain the processes of microbially mediated alteration of the MSW glasses in the biosphere.

  2. Influence of bacteria on lanthanide and actinide transfer from specific soil components (humus, soil minerals and vitrified municipal solid waste incinerator bottom ash) to corn plants: Sr-Nd isotope evidence.

    Science.gov (United States)

    Aouad, Georges; Stille, Peter; Crovisier, Jean-Louis; Geoffroy, Valérie A; Meyer, Jean-Marie; Lahd-Geagea, Majdi

    2006-11-01

    Experiments have been performed to test the stability of vitrified municipal solid waste (MSW) incinerator bottom ash under the presence of bacteria (Pseudomonas aeruginosa) and plants (corn). The substratum used for the plant growth was a humus-rich soil mixed with vitrified waste. For the first time, information on the stability of waste glasses in the presence of bacteria and plants is given. Results show that inoculated plant samples contained always about two times higher lanthanide and actinide element concentrations. Bacteria support the element transfer since plants growing in inoculated environment developed a smaller root system but have higher trace element concentrations. Compared with the substratum, plants are light rare earth element (LREE) enriched. The vitrified bottom ash has to some extent been corroded by bacteria and plant activities as indicated by the presence of Nd (REE) and Sr from the vitrified waste in the plants. (87)Sr/(86)Sr and (143)Nd/(144)Nd isotope ratios of plants and soil components allow the identification of the corroded soil components and confirm that bacteria accelerate the assimilation of elements from the vitrified bottom ash. These findings are of importance for landfill disposal scenarios, and similar experiments should be performed in order to better constrain the processes of microbially mediated alteration of the MSW glasses in the biosphere.

  3. Recombination of atomic oxygen on α-Al 2O 3 at high temperature under air microwave-induced plasma

    Science.gov (United States)

    Balat-Pichelin, M.; Bedra, L.; Gerasimova, O.; Boubert, P.

    2007-11-01

    New ceramic materials are necessary for the design of primary heat shields for future reusable space vehicles re-entering atmospheric planet. During the re-entry phase on earth, one of the most important phenomena occurring on the heat shield is the recombination of atomic species and among them atomic oxygen. The recombination of atomic oxygen is catalyzed by the material of the heat shield. This paper presents some experimental results for the recombination coefficient γ and the thermal flux of recombination transferred to the material in the surface-catalyzed recombination of oxygen atoms based on experiments performed on the MESOX set-up using optical emission spectroscopy, actinometry and calorimetry techniques. Experimental results on the recombination coefficient are presented for three types of α-Al 2O 3 in the temperature range 900-2400 K for 300 Pa total air pressure. The thermal flux of recombination is given for only two representative samples. These three alumina differ essentially by their content of sintering additives. Different behaviors of the recombination coefficient versus temperature are observed according to the impurity level of the α-alumina.

  4. Effects of supplementation with antifreeze proteins on the follicular integrity of vitrified-warmed mouse ovaries: Comparison of two types of antifreeze proteins alone and in combination.

    Science.gov (United States)

    Kim, Min Kyung; Kong, Hyun Sun; Youm, Hye Won; Jee, Byung Chul

    2017-03-01

    The aim of this study was to analyze the effect of supplementing vitrification and warming solutions with two types of antifreeze proteins (AFPs) and the combination thereof on the follicular integrity of vitrified-warmed mouse ovaries. Ovaries (n=154) were obtained from 5-week-old BDF1 female mice (n=77) and vitrified using ethylene glycol and dimethyl sulfoxide with the supplementation of 10 mg/mL of Flavobacterium frigoris ice-binding protein (FfIBP), 10 mg/mL of type III AFP, or the combination thereof. Ovarian sections were examined by light microscopy after hematoxylin and eosin staining, and follicular intactness was assessed as a whole and according to the type of follicle. Apoptosis within the follicles as a whole was detected by a terminal deoxynucleotidyl transferase deoxyuridine triphosphate nick-end labeling assay. The proportion of overall intact follicles was significantly higher in the type III AFP-supplemented group (60.5%) and the combination group (62.9%) than in the non-supplemented controls (43.8%, p<0.05 for each). The proportion of intact primordial follicles was significantly higher in the FfIBP-supplemented (90.0%), type III AFP-supplemented (92.3%), and combination (89.7%) groups than in the non-supplemented control group (46.2%, p<0.05 for each). The proportions of non-apoptotic follicles were similar across the four groups. Supplementation of the vitrification and warming solutions with FfIBP, type III AFP, or the combination thereof was equally beneficial for the preservation of primordial follicles in vitrified mouse ovaries.

  5. Efficacy of in vitro embryo transfer in lactating dairy cows using fresh or vitrified embryos produced in a novel embryo culture medium.

    Science.gov (United States)

    Block, J; Bonilla, L; Hansen, P J

    2010-11-01

    Objectives were to determine whether pregnancy success could be improved in lactating cows with timed embryo transfer when embryos were produced in vitro using a medium designed to enhance embryo development and survival after cryopreservation. In experiment 1, embryos (n=569 to 922) were cultured in either modified synthetic oviduct fluid or a serum-free medium, Block-Bonilla-Hansen-7 (BBH7). Development to the blastocyst stage was recorded at d 7, and selected blastocysts (n=79 to 114) were vitrified using open pulled straws. Culture of embryos in BBH7 increased development to the blastocyst stage (41.9±2.0 vs. 14.7±2.0%) and advanced blastocyst stages (expanded, hatching, hatched; 31.1±1.3 vs. 6.4±1.3%) at d 7 and resulted in higher hatching rates at 24h postwarming compared with embryos cultured in modified synthetic oviduct fluid (59.0±0.5 vs. 26.7±0.5%). In experiment 2, embryos were produced using X-sorted semen and cultured in BBH7. At d 7 after insemination, embryos were transferred fresh or following vitrification. Lactating Holstein cows were either subjected to timed artificial insemination (TAI) on the day of presumptive ovulation or used as embryo recipients 7 d later. Embryo recipients received an embryo if a corpus luteum was present. The percentage of cows pregnant at d 32, 46, and 76 of gestation was higher among cows that received fresh embryos compared with TAI cows or cows that received vitrified embryos. At d 76, for example, the proportion and percentage pregnant was 47/150 (31.3%) for cows subjected to TAI, 48/95 (50.5%) for cows receiving fresh embryos, and 39/141 (27.7%) for cows receiving a vitrified embryo. No difference was observed in the percentage of cows pregnant among TAI cows and those that received vitrified embryos. There was a service or transfer number × treatment interaction because differences in pregnancy rate between embryo transfer recipients and cows bred by TAI were greater for cows with more than 3 services or

  6. A modified natural cycle results in higher live birth rate in vitrified-thawed embryo transfer for women with regular menstruation.

    Science.gov (United States)

    Guan, Yichun; Fan, Hongfang; Styer, Aaron K; Xiao, Zhiying; Li, Zhen; Zhang, Jianrui; Sun, Lijun; Wang, Xingling; Zhang, Zhan

    2016-10-01

    There is no consensus regimen for the optimal endometrial preparation for cryopreservation and vitrified-thawed embryo transfer cycles. This is largely caused by the lack of sufficient investigation and analyses on the respective pregnancy and perinatal outcomes by different regimens. This study aimed to compare both pregnancy and perinatal outcomes between the modified natural and artificial cycles in vitrified-thawed day three embryo transfer for women with regular menstruation. A total of 1,482 vitrified-thawed day three embryo transfer cycles were reviewed including 427 modified natural cycles (NC), 132 ovulation induction cycles (OC), 794 artificial cycles (AC), and 129 GnRH agonist artificial cycles (GAC). The primary outcome that was evaluated was live birth rate. The NC regimen demonstrated a higher rate of ongoing pregnancy (43.8% vs. 30.2%, P = 0.002) and a lower rate of late abortion (2.8% vs. 14.0%, P = 0.003) than the GAC regimen as well as a higher implantation rate (31.9% vs. 27.1%, P = 0.008) and live birth rate (43.1% vs. 34.1%, P = 0.002) than the AC regimen. A significantly higher peak endometrial thickness before transfer was observed in patients using the NC and GAC regimens (10.0 ± 1.7, 9.9 ± 2.4) compared to the AC regimens (9.2 ± 1.5, P = 0.000). Multivariate logistic regression showed that the NC protocol was associated with a higher live birth rate. There were no significant differences in rates of pregnancy complications, neonatal mortality, birth defects, mean birth weight, and other perinatal outcomes among the regimens. Modified natural cycle endometrial preparation regimen for vitrified-thawed day three embryo transfer is associated with superior live birth pregnancy outcomes compared to artificial cycles. Future studies are warranted to investigate the underlying biologic mechanisms of these findings. Abbreviations ART: assisted reproductive technology; BMI: body mass index; FET: frozen-thawed embryo transfer; HCG: human chorionic

  7. Analytical performances of laser-induced micro-plasma of Al samples with single and double ultrashort pulses in air and with Ar-jet: A comparative study

    Energy Technology Data Exchange (ETDEWEB)

    Semerok, A., E-mail: alexandre.semerok@cea.fr [CEA Saclay, DEN/DPC/SEARS/LISL, 91191 Gif-sur-Yvette (France); Dutouquet, C. [CEA Saclay, DEN/DPC/SEARS/LISL, 91191 Gif-sur-Yvette (France); INERIS/DRC/CARA/NOVA, F-60550 Verneuil En Halatte (France)

    2014-09-01

    Ultrashort pulse laser microablation coupled with optical emission spectroscopy was under study to obtain several micro-LIBS analytical features (shot-to-shot reproducibility, spectral line intensity and lifetime, calibration curves, detection limits). Laser microablation of Al matrix samples with known Cu- and Mg-concentrations was performed by single and double pulses of 50 fs and 1 ps pulse duration in air and with Ar-jet. The micro-LIBS analytical features obtained under different experimental conditions were characterized and compared. The highest shot-to-shot reproducibility and gain in plasma spectral line intensity were obtained with double pulses with Ar-jet for both 50 fs and 1 ps pulse durations. The best calibration curves were obtained with 1 ps pulse duration with Ar-jet. Micro-LIBS with ultrashort double pulses may find its effective application for surface elemental microcartography. - Highlights: • Analytical performances of micro-LIBS with ultrashort double pulses were studied. • The maximal line intensity gain of 20 was obtained with double pulses and Ar-jet. • LIBS gain was obtained without additional ablation of a sample by the second pulse. • LIBS properties were almost the same for both 50 fs and 1 ps pulses. • The micro-LIBS detection limit was around 35 ppm.

  8. Microstructure studies of air-plasma-spray-deposited CoNiCrAlY coatings before and after thermal cyclic loading for high-temperature application

    Institute of Scientific and Technical Information of China (English)

    Dipak Kumar; KN Pandey; Dipak Kumar Das

    2016-01-01

    In the present study, bond-coats for thermal barrier coatings were deposited via air plasma spraying (APS) techniques onto Inconel 800 and Hastelloy C-276 alloy substrates. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and atomic force microscopy (AFM) were used to investigate the phases and microstructure of the as-sprayed, APS-deposited CoNiCrAlY bond-coatings. The aim of this work was to study the suitability of the bond-coat materials for high temperature applications. Confirmation of nanoscale grains of theγ/γ′-phase was obtained by TEM, high-resolution TEM, and AFM. We concluded that these changes result from the plastic deformation of the bond-coat during the deposition, resulting in CoNiCrAlY bond-coatings with excellent thermal cy-clic resistance suitable for use in high-temperature applications. Cyclic oxidative stability was observed to also depend on the underlying metallic alloy substrate.

  9. Microstructure studies of air-plasma-spray-deposited CoNiCrAlY coatings before and after thermal cyclic loading for high-temperature application

    Science.gov (United States)

    Kumar, Dipak; Pandey, K. N.; Das, Dipak Kumar

    2016-08-01

    In the present study, bond-coats for thermal barrier coatings were deposited via air plasma spraying (APS) techniques onto Inconel 800 and Hastelloy C-276 alloy substrates. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and atomic force microscopy (AFM) were used to investigate the phases and microstructure of the as-sprayed, APS-deposited CoNiCrAlY bond-coatings. The aim of this work was to study the suitability of the bond-coat materials for high temperature applications. Confirmation of nanoscale grains of the γ/γ'-phase was obtained by TEM, high-resolution TEM, and AFM. We concluded that these changes result from the plastic deformation of the bond-coat during the deposition, resulting in CoNiCrAlY bond-coatings with excellent thermal cyclic resistance suitable for use in high-temperature applications. Cyclic oxidative stability was observed to also depend on the underlying metallic alloy substrate.

  10. Insights on the High-Temperature Operational Limits of ZrO2-Y2O3 TBCs Manufactured via Air Plasma Spray

    Science.gov (United States)

    Lima, Rogerio S.; Marple, Basil R.

    2017-02-01

    The effective high-temperature operation limit of a ZrO2-7-8 wt.%Y2O3 (YSZ) thermal barrier coating (TBC) manufactured via air plasma spray (APS) is considered to be 1300 °C. This is related to the metastable tetragonal t'-phase formed during the rapid quenching of the YSZ particles during spraying. The t'-phase transforms into the equilibrium tetragonal and cubic phases at temperatures ≥ 1300 °C, which can lead to the formation of the monoclinic phase of YSZ upon cooling to room temperature. This formation of the monoclinic phase is accompanied by a volume expansion that leads to TBC failure due to extensive micro-cracking. To further investigate this limitation, an APS YSZ TBC was sprayed on a CMSX-4 substrate. By using a thermal (laser) gradient cyclic testing, a temperature gradient was generated across the TBC/substrate system. The YSZ T-front and substrate backside T-back temperature levels were 1500 and 1000 °C, respectively. In cycle conditions (5-min or 1-h hot and 2-min cool), no TBC failure has been observed. This behavior was partially attributed to the unexpected absence of the monoclinic phase of the YSZ in the cycled coatings. Although preliminary, these results are promising regarding increasing the effective high-temperature operational limits of APS YSZ TBCs.

  11. Air atmospheric pressure plasma jet pretreatment for drop-wise loading of dexamethasone on hydroxyapatite scaffold for increase of osteoblast attachment.

    Science.gov (United States)

    Lee, Jung-Hwan; Kwon, Jae-Sung; Kim, Yong Hee; Choi, Eun Ha; Kim, Kwang-Mahn; Kim, Kyoung-Nam

    2014-10-01

    Periodontal disease affects alveolar bone resorption around the involved teeth. To gain bone height, bone graft materials have been widely used with drug carriers. Application of an atmospheric pressure plasma jet (APPJ) treatment is widely studied due to its ability to change surface characteristics without topographical change. The aim of this study is to identify whether the air APPJ (AAPPJ) treatment before drop-wise loading performance could change loaded amount of dexamethasone, and induce increase of cell attachment and proliferation. The results suggested that AAPPJ treatment decreased the contact angle down to about 13 degrees, which increased gradually but significantly lowered at least 4 days compared to no-treated group. After AAPPJ treatment, hydrocarbon was removed with change of zeta potential into positive charge. However, the AAPPJ treatment did not change the quantity or releasing profile of dexamethasone (p > 0.05). Confocal analysis combined with DNA proliferation analysis showed increase of osteoblast attachment and proliferation. Hence, AAPPJ could be a useful pretreatment method before drop-wise loading on HA scaffold with dexamethasone for increase of osteoblast attachment.

  12. Study of Purification Effects of Air Cleaners with Non-thermal Plasma on Indoor Particular Matter%含NTP技术净化器对室内颗粒物的净化效果

    Institute of Scientific and Technical Information of China (English)

    陆海全; 丁志威; 颜凯; 梅敏花; 郭婷; 钟依均; 谢云龙

    2015-01-01

    选择几款国内含有低温等离子体( Non-thermal plasma, NTP)技术的空气净化器( air cleaner)样机,以香烟烟雾为净化对象,研究其对室内空气中颗粒物的净化效果。结果表明,所选用空气净化器对100 nm以上颗粒物有一定的去除效果,对100 nm以下的颗粒物几乎没有净化效果;单一采用低温等离子体净化技术对颗粒物的去除不理想;高效粒子过滤器( HEPA, High efficiency particulate air Filter)对颗粒物的净化起着关键作用。%Using cigarette smoke as the purification target, the purification effects of several residential air cleaners containing non-thermal plasma ( NTP) technology on indoor particulate matter in air were studied. The results showed that the selected air cleaners had a certain effect on removal of particles above 100 nm while had few effects for particles below 100 nm. Single use of NTP purification technology was not effective to remove particulate matter. HEPA technology played a key role in eliminating the particulate matter.

  13. Analysis of Surface Leaching Processes in Vitrified High-Level Nuclear Wastes Using In-Situ Raman Imaging and Atomistic Modeling - Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Simmons, Joseph H.

    2001-04-24

    The in situ analysis of surface conditions of vitrified nuclear wastes can provide an important check of the burial status of radioactive objects without risk of radiation exposure. Raman spectroscopy was initially chosen as the most promising method for testing the surface conditions of glasses undergoing chemical corrosion, and was used extensively during the first year. However, it was determined that infrared reflection spectroscopy was better suited to this particular need and was used for the remaining two years to investigate the surface corrosion behavior of model silicate glasses for extension to nuclear waste glasses. The developed methodology is consistent with the known theory of optical propagation of dielectric media and uses the Kramers-Kronig formalism. The results show that it is possible to study the corrosion of glass by analyzing the glass surface using reflection fast Fourier infrared measurements and the newly developed ''dispersion analysis method.'' The data show how this analysis can be used to monitor the corrosion behavior of vitrified waste glasses over extended periods of storage.

  14. Superovulation of the Cloned Cattle Derived from Somatic Cells and the Transfer of the Vitrified-Thawed Embryos of the Cloning Cattle

    Institute of Scientific and Technical Information of China (English)

    DONG Ya-juan; BAI Xue-jin; LI Jian-dong; CHENG Ming

    2004-01-01

    In this experiment, it was designed to carry out superovulation on the two cloned cattles, vitrification and transfer of the embryos recovered from them. First of all, it was carried out vitrification on embryos obtained by IVF. Results showed that there were no significant differences between the blastocysts (obtained by IVF) vitrified in EPS10 and these in EPS20 on the resuscitative rate and the developmental rate. The hatched rate of the blastocysts vitrified in EPS10 (31.3%, 35/112) was significantly higher than that in EPS20 (12.2%, 13/107) (P<0.01), so EPS20 was selected as the vitrification solution to freeze the embryos recovered from the cloned cattle. After superovulation, six (four usable embryos) and ten (nine usable embryos) embryos were respectively recovered from Kangkang and Shuanghuang. Two embryos were selected from the recovered embryos of each cloned cattle to freeze in EPS20, subsequently thawed and transferred into luteal ipsilateral uterine horns of 4 Holstein recipient cows after synchronization of estrus, respectively. At last, one recipient cow (No. 9908) became pregnant and delivered one healthy calf (descendant of the cloned cattle-Shuangshuang). The results of this experiment show that the cloned cattle as well as common cattle had better response to the exotic FSH and better ability to multiovulation, the embryos recovered from the cloned cattle can be vitrificated.

  15. Prediction models of long-term leaching behavior and leaching mechanism of glass components and surrogated nuclides in radioactive vitrified waste forms

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Y. C.; Lee, K. S. [Department of Industrial Environment and Health, Yonsei University, Wonju (Korea, Republic of); Kim, I. T.; Kim, H. T.; Kim, J. H. [Korea Atomic Energy Research Institute (KAERI), Taejon (Korea, Republic of)

    1999-07-01

    Melting solidification is considered to be a perspective technology for stabilizing incineration ash remaining after incineration of combustible radioactive waste since it has the advantage of improving the physicochemical properties of waste forms. Final waste forms should be characterized to determine the degree to which they fulfills the acceptance criteria of the disposal facility. Chemical durability (leaching resistance) is known to be the most important factor in the assessment of waste forms. In this study, vitrified waste forms are manufactured and characterized. Feed materials consist of simulated radioactive incineration ash and base-glass with different mixing ratios. To assess the chemical durability of vitrified waste forms, the International Standard Organization (ISO) leach test has been conducted at 70 degree C with deionized distilled water as a leachant for 820 days, and the concentrations of glass components and surrogates in the leachates are then analyzed. Two models for predicting long-term leaching behavior of glass components and radionuclides in a glass form are applied to the leached data after 820 days. The model including a fitted parameter from the longer experimental data shows more accuracy, however, the model with shorter leaching test results offers the advantage of being able to predict the long-term behavior from the short-term experimental data. The leaching mechanisms of surrogates and glass components were also investigated by using two semi-empirical kinetic models and were found to be dissolution with diffusion. (author)

  16. Quality of Oocytes Derived from Vitrified Ovarian Follicles Cultured in Two- and Three-Dimensional Culture System in the Presence and Absence of Kit Ligand.

    Science.gov (United States)

    Abdi, Shabnam; Salehnia, Mojdeh; Hosseinkhani, Saman

    2016-08-01

    The aim of this study was to evaluate the effects of Kit Ligand (KL) on the growth of vitrified follicle, oocyte quality, and embryo development in two- and three-dimensional culture systems. Vitrified and nonvitrified mouse whole ovaries were cultured for 1 week, then their isolated preantral follicles were cultured for 12 days in two- or three-dimensional culture systems in the presence and absence of KL. The growth and diameter of follicles, maturation of oocytes, and hormonal level were assessed. Finally, embryo developmental rate and oocytes reactive oxygen species (ROS) levels, adenosine triphosphate (ATP) content, and distribution of mitochondria were examined. The results showed the maturation and survival rates and steroidogenesis of follicles were significantly higher not only in the three-dimensional culture system but also in the presence of KL (p culture in two- and three-dimensional culture systems appeared to significantly increase follicular function and development. The ovarian vitrification had no harmful effect on the steroidogenesis, growth, and maturation of follicles.

  17. Thermal plasma technology for the treatment of wastes: a critical review.

    Science.gov (United States)

    Gomez, E; Rani, D Amutha; Cheeseman, C R; Deegan, D; Wise, M; Boccaccini, A R

    2009-01-30

    This review describes the current status of waste treatment using thermal plasma technology. A comprehensive analysis of the available scientific and technical literature on waste plasma treatment is presented, including the treatment of a variety of hazardous wastes, such as residues from municipal solid waste incineration, slag and dust from steel production, asbestos-containing wastes, health care wastes and organic liquid wastes. The principles of thermal plasma generation and the technologies available are outlined, together with potential applications for plasma vitrified products. There have been continued advances in the application of plasma technology for waste treatment, and this is now a viable alternative to other potential treatment/disposal options. Regulatory, economic and socio-political drivers are promoting adoption of advanced thermal conversion techniques such as thermal plasma technology and these are expected to become increasingly commercially viable in the future.

  18. Characterization and antimicrobial efficacy against E. coli of a helium/air plasma at atmospheric pressure created in a plastic package

    Science.gov (United States)

    Connolly, J.; Valdramidis, V. P.; Byrne, E.; Karatzas, K. A.; Cullen, P. J.; Keener, K. M.; Mosnier, J. P.

    2013-01-01

    A plasma source, sustained by the application of a floating high voltage (±15 kV) to parallel-plate electrodes at 50 Hz, has been achieved in a helium/air mixture at atmospheric pressure (P = 105 Pa) contained in a zip-locked plastic package placed in the electrode gap. Some of the physical and antimicrobial properties of this apparatus were established with a view to ascertain its performance as a prototype for the disinfection of fresh produce. The current-voltage (I-V) and charge-voltage (Q-V) characteristics of the system were measured as a function of gap distance d, in the range (3 × 103 ⩽ Pd ⩽ 1.0 × 104 Pa m). The electrical measurements showed this plasma source to exhibit the characteristic behaviour of a dielectric barrier discharge in the filamentary mode and its properties could be accurately interpreted by the two-capacitance in series model. The power consumed by the discharge and the reduced field strength were found to decrease quadratically from 12.0 W to 4.5 W and linearly from 140 Td to 50 Td, respectively, in the range studied. Emission spectra of the discharge were recorded on a relative intensity scale and the dominant spectral features could be assigned to strong vibrational bands in the 2+ and 1- systems of N2 and N_2^+ , respectively, with other weak signatures from the NO and OH radicals and the N+, He and O atomic species. Absolute spectral intensities were also recorded and interpreted by comparison with the non-equilibrium synthetic spectra generated by the computer code SPECAIR. At an inter-electrode gap of 0.04 m, this comparison yielded typical values for the electron, vibrational and translational (gas) temperatures of (4980 ± 100) K, (2700 ± 200) K and (300 ± 100) K, respectively and an electron density of 1.0 × 1017 m-3. A Boltzmann plot also provided a value of (3200 ± 200 K) for the vibrational temperature. The antimicrobial efficacy was assessed by studying the resistance of both Escherichia coli K12 its isogenic

  19. Determination of the Structure of Vitrified Hydroceramic/CBC Waste Form Glasses Manufactured from DOE Reprocessing Waste

    Energy Technology Data Exchange (ETDEWEB)

    Scheetz, B.E.; White, W. B.; Chesleigh, M.; Portanova, A.; Olanrewaju, J.

    2005-05-31

    The selection of a glass-making option for the solidification of nuclear waste has dominated DOE waste form programs since the early 1980's. Both West Valley and Savannah River are routinely manufacturing glass logs from the high level waste inventory in tank sludges. However, for some wastes, direct conversion to glass is clearly not the optimum strategy for immobilization. INEEL, for example, has approximately 4400 m{sup 3} of calcined high level waste with an activity that produces approximately 45 watts/m{sup 3}, a rather low concentration of radioactive constituents. For these wastes, there is value in seeking alternatives to glass. An alternative approach has been developed and the efficacy of the process demonstrated that offers a significant savings in both human health and safety exposures and also a lower cost relative to the vitrification option. The alternative approach utilizes the intrinsic chemical reactivity of the highly alkaline waste with the addition of aluminosilicate admixtures in the appropriate proportions to form zeolites. The process is one in which a chemically bonded ceramic is produced. The driving force for reaction is derived from the chemical system itself at very modest temperatures and yet forms predominantly crystalline phases. Because the chemically bonded ceramic requires an aqueous medium to serve as a vehicle for the chemical reaction, the proposed zeolite-containing waste form can more adequately be described as a hydroceramic. The hydrated crystalline materials are then subject to hot isostatic pressing (HIP) which partially melts the material to form a glass ceramic. The scientific advantages of the hydroceramic/CBC approach are: (1) Low temperature processing; (2) High waste loading and thus only modest volumetric bulking from the addition of admixtures; (3) Ability to immobilize sodium; (4) Ability to handle low levels of nitrate (2-3% NO{sub 3}{sup -}); (5) The flexibility of a vitrifiable waste; and (6) A process

  20. Outcomes of vitrified-warmed cleavage-stage embryo hatching after in vitro laser-assisted zona pellucida thinning in patients

    Science.gov (United States)

    Wang, En-Hua; Wang, An-Cong; Wang, Bao-Song; Li, Bin

    2016-01-01

    The aim of the present study was to determine whether the size of the zona pellucida (ZP) thinning area by laser-assisted hatching affected the potential development of vitrified-warmed embryos. A total of 196 vitrified-warmed cleavage-stage embryos (from 49 patients, four sister embryos per patient) were used in the study, i.e., four sister embryos from each patient were randomly assigned to four groups: a control group of embryos that were not zona-manipulated (zona intact, group A); one experimental group of embryos in which a quarter of the zona pellucida was thinned using laser-assisted ZP thinning (group B); a second experimental group of embryos in which half of ZP was thinned (group C); and a third group in which two-thirds of the ZP was thinned (group D). Subsequent blastocyst development was assessed. Microscopy was performed to study the hatching process of the embryos after zona thinning. The blastocyst formation rates were 71.43% in group A, 67.35% in group B, 65.31% in group C, and 51.02% in group D (groups B-D vs. group A, P=0.661, P=0.515, P=0.038, respectively). The rates of complete hatching were 30.61% in group A, 38.78% in group B, 61.22% in group C, and 48.98% in group D (groups B-D vs. group A, P=0.396, P=0.002, P=0.063, respectively). For a subgroup of patients, there was a significant difference in the complete hatching in all the groups for women aged infertility women (P=0.022). There was no significant difference in the blastocyst formation rates in the different groups of women aged ≥35 years (P=0.340). In addition, there was no significant difference in the complete hatching in the different groups among women aged ≥35 years (P=0.492). The results of the present study showed that in vitrified-warmed embryo transfers at the cleavage-stage, and the two-thirds zona pellucida thinning group demonstrated a significantly decreased blastocyst formation rate compared with the control group, while the half zona pellucida thinning group

  1. 脉冲 CO2激光诱导空气等离子体的光谱诊断%Spectroscopic diagnosis of air plasma induced by pulsed CO2 laser

    Institute of Scientific and Technical Information of China (English)

    唐建; 左都罗; 杨晨光; 程祖海

    2013-01-01

      为了了解激光诱导等离子体的演化过程,得到等离子体的相关参量,采用横向激励大气压CO2激光器在抛物反射面中聚焦击穿空气形成等离子体,利用成像光谱仪和增强型CCD探测器对激光诱导等离子体进行了时间和空间分辨的实验分析,取得了激光诱导空气等离子体的时间演化和空间分辨光谱。分别利用氧原子的线状谱和连续谱的比值及谱线半峰全宽计算得到电子温度达到了4×104 K,电子密度在1018 cm-3量级。结果表明,相比于低能量的激光诱导等离子体的辐射光谱,高能量激光诱导的等离子体则向外辐射出很强的连续光谱,同时,等离子体以激光支持爆轰波的形式快速向外膨胀,由于外围等离子体对激光能量的屏蔽作用,等离子体出现了空间分离的现象。该研究结果对理解等离子体和高能量脉冲激光的相互作用过程是有帮助的。%In order to study the evolution of laser-induced plasma and obtain the properties of plasma , transversely excited atmospheric CO 2 laser was focused by a parabolic reflector to generate air breakdown plasma .Based on the imaging spectrometer system and intensified CCD detector , time-space resolution of laser-induced air plasma were investigated and the time evolution spectra and the space resolution spectra of plasma were obtained .Electron temperature of about 4 ×104 K and electron density of 1018 cm-3 were calculated respectively by using the ratio of oxygen line spectrum and continuous spectrum and full width at half maximum of spectral line .The results show high-energy laser-induced plasma spectra radiate the intense continuous spectra outward , comparing with low-energy laser-induced plasma spectra .At the same time , laser-induced air plasma expands outward rapidly with the way of the laser-supported detonation wave .Due to the shielding effect of laser power , laser-induced air plasma shows the

  2. Aqueous-phase chemistry and bactericidal effects from an air discharge plasma in contact with water: evidence for the formation of peroxynitrite through a pseudo-second-order post-discharge reaction of H2O2 and HNO2

    Science.gov (United States)

    Lukes, P.; Dolezalova, E.; Sisrova, I.; Clupek, M.

    2014-02-01

    The formation of transient species (OH·, NO2·, NO radicals) and long-lived chemical products (O3, H2O2, NO_{3}^{-} , NO_{2}^{-} ) produced by a gas discharge plasma at the gas-liquid interface and directly in the liquid was measured in dependence on the gas atmosphere (20% oxygen mixtures with nitrogen or with argon) and pH of plasma-treated water (controlled by buffers at pH 3.3, 6.9 or 10.1). The aqueous-phase chemistry and specific contributions of these species to the chemical and biocidal effects of air discharge plasma in water were evaluated using phenol as a chemical probe and bacteria Escherichia coli. The nitrated and nitrosylated products of phenol (4-nitrophenol, 2-nitrophenol, 4-nitrocatechol, 4-nitrosophenol) in addition to the hydroxylated products (catechol, hydroquinone, 1,4-benzoquinone, hydroxy-1,4-benzoquinone) evidenced formation of NO2·, NO· and OH· radicals and NO+ ions directly by the air plasma at the gas-liquid interface and through post-discharge processes in plasma-activated water (PAW) mediated by peroxynitrite (ONOOH). Kinetic study of post-discharge evolution of H2O2 and NO_{2}^{-} in PAW has demonstrated excellent fit with the pseudo-second-order reaction between H2O2 and NO_{2}^{-} . The third-order rate constant k = 1.1 × 103 M-2 s-1 for the reaction NO_{2}^{-} +H_{2}O_{2}+H^{+}\\to ONOOH+H_{2}O was determined in PAW at pH 3.3 with the rate of ONOOH formation in the range 10-8-10-9 M s-1. Peroxynitrite chemistry was shown to significantly participate in the antibacterial properties of PAW. Ozone presence in PAW was proved indirectly by pH-dependent degradation of phenol and detection of cis,cis-muconic acid, but contribution of ozone to the inactivation of bacteria by the air plasma was negligible.

  3. Application of Air Film Technology in Plasma Coal Pyrolysis to Acetylene%气膜技术在等离子煤裂解制乙炔技术中的应用

    Institute of Scientific and Technical Information of China (English)

    刘军; 熊新阳; 李永宏; 唐复兴; 黄峥嵘; 陈财来

    2013-01-01

    The development history of the plasma coal paralysis to acetylene was briefly introduced;especially the difficulties in re-search process and corresponding solutions. The research broke the technical barriers to the reactor design by the air film technol-ogy, and laid a solid foundation for the long experiment of plasma coal pyrolysis to acetylene%  简单介绍了等离子煤制乙炔项目的发展历程,特别是其中反应器研究过程中遇到的困难以及应对的办法,利用气膜技术突破了反应器设计的技术壁垒,为等离子煤制乙炔的长时间实验奠定坚实基础。

  4. Deterioration to extinction of wastewater bacteria by non-thermal atmospheric pressure air plasma as assessed by 16S rDNA-DGGE fingerprinting.

    Science.gov (United States)

    El-Sayed, Wael S; Ouf, Salama A; Mohamed, Abdel-Aleam H

    2015-01-01

    The use of cold plasma jets for inactivation of a variety of microorganisms has recently been evaluated via culture-based methods. Accordingly, elucidation of the role of cold plasma in decontamination would be inaccurate because most microbial populations within a system remain unexplored owing to the high amount of yet uncultured bacteria. The impact of cold atmospheric plasma on the bacterial community structure of wastewater from two different industries was investigated by metagenomic-based polymerase chain reaction-denaturing gradient gel electrophoresis (DGGE) utilizing 16S rRNA genes. Three doses of atmospheric pressure dielectric barrier discharge plasma were applied to wastewater samples on different time scales. DGGE revealed that the bacterial community gradually changed and overall abundance decreased to extinction upon plasma treatment. The bacterial community in food processing wastewater contained 11 key operational taxonomic units that remained almost completely unchanged when exposed to plasma irradiation at 75.5 mA for 30 or 60 s. However, when exposure time was extended to 90 s, only Escherichia coli, Coliforms, Aeromonas sp., Vibrio sp., and Pseudomonas putida survived. Only E. coli, Aeromonas sp., Vibrio sp., and P. putida survived treatment at 81.94 mA for 90 s. Conversely, all bacterial groups were completely eliminated by treatment at 85.34 mA for either 60 or 90 s. Dominant bacterial groups in leather processing wastewater also changed greatly upon exposure to plasma at 75.5 mA for 30 or 60 s, with Enterobacter aerogenes, Klebsiella sp., Pseudomonas stutzeri, and Acidithiobacillus ferrooxidans being sensitive to and eliminated from the community. At 90 s of exposure, all groups were affected except for Pseudomonas sp. and Citrobacter freundii. The same trend was observed for treatment at 81.94 mA. The variability in bacterial community response to different plasma treatment protocols revealed that plasma had a selective impact on bacterial

  5. Characterisation of C–F Polymer Film Formation on the Air-Bearing Surface Etched Sidewall of Fluorine-Based Plasma Interacting with AL2O3–TiC Substrate

    Directory of Open Access Journals (Sweden)

    Alonggot Limcharoen

    2013-01-01

    Full Text Available C–F polymer redeposition is generated on the etched sidewall of the patterned air-bearing surface (ABS. This C–F polymer is a by-product from fluorine-based plasma using a Surface Technology Systems multiplex-pro air-bearing etch (ABE. The morphology of the re-deposition and the composite element was observed by a scanning electron microscope (SEM. The chemical bonding results were characterised via X-ray photoelectron spectroscopy, attenuated total reflected infrared spectroscopy and visible Raman spectroscopy. The purpose of this work is to demonstrate a modification of AlF3 re-deposition to C–F polymer re-deposition, which is easily stripped out by an isopropyl alcohol-based solution. The benefit of this research is the removal of the re-deposition in the resist strip process without additional cleaning process steps.

  6. 应用母血浆中AIRE基因对唐氏综合征进行产前诊断%Prenatal Diagnosis of Down Syndrome by AIRE Gene in Maternal Plasma

    Institute of Scientific and Technical Information of China (English)

    方爱平; 陈德珩; 文景丽; 范海波; 王英兰; 张悦; 胡泓

    2011-01-01

    目的 应用母血浆中AIRE基因作为胎儿DNA遗传学标记,探讨无创性产前筛查唐氏综合征(Down syndrome,DS)的可行性.方法 提取随机选取的45名正常孕妇血浆中游离DNA,同时以15名非妊娠健康妇女血浆游离DNA作为对照,通过巢式甲基化特异性PCR检测游离DNA中AIRE基因的甲基化状态;提取15名产妇胎盘组织和母血单核细胞中的DNA,检测AIRE基因的甲基化状态;采集20例确诊为DS胎儿的高危孕妇外周血,以45名正常孕妇外周血作为对照,检测AIRE基因甲基化状态.结果 正常孕妇血浆中AIRE基因的甲基化率比非妊娠健康妇女高(P<0.01);所有产妇胎盘组织中均能检测到AIRE基因的甲基化,而在母血单核细胞中未检测到;在确诊为DS胎儿的高危孕妇外周血中,AIRE基因的甲基化率远远低于正常胎儿孕妇外周血(P<0.01).结论 应用巢式甲基化特异性PCR技术检测妊娠期母血浆中AIRE基因的甲基化状态对胎儿DS进行非创伤性产前诊断是可行的.%Objective To study the feasibility of noninvasive prenatal diagnosis of Down syndrome (DS) through the AIRE gene in maternal plasma as the fetal DNA genetic mark. Methods Free DNAs were extracted from the plasma of 45 pregnant women selected randomly and determined for methylation status of AIRE gene by Nested methylation-specific PCR(Nested-MSP), using those from 15 nonpregnant women as control. Free DNAs were extracted from the placenta and monocytes in blood of 15 lying-in women and determined for methylation status of AIRE gene. Peripheral blood samples of 10 high-risk pregnant women whose fetus were diagnosed as patients with DS and 45 normal pregnant women were collected and determined for methylation status of AIRE gene. Results The methylation rate of AIRE gene in the plasma of pregnant women was significantly higher than that of nonpregnant women (P < 0. 01). The methylation of AIRE gene was observed in all the placenta of

  7. 玻化微珠保温砂浆性能的影响因素分析%Analysis of the influence with the vitrified microsphere thermal insulation mortar

    Institute of Scientific and Technical Information of China (English)

    张雷

    2013-01-01

    This paper describes thelatest research results for vitrified microsphere thermal insulation mortar with aggregate gradation and additive. Analyses and comparisons are made on these results, and proposal for further developing vitrified micro-sphere thermal insulation mortar in our country is put forward for reference.%本文通过介绍玻化微珠保温砂浆中骨料级配、掺加剂的种类及掺加量对保温砂浆的性能影响方面的最新研究成果,并对这些成果进行分析,对进一步发展我国玻化微珠保温砂浆提出建议,以供参考。

  8. Destruction of inorganic municipal solid waste incinerator fly ash in a DC arc plasma furnace.

    Science.gov (United States)

    Zhao, Peng; Ni, Guohua; Jiang, Yiman; Chen, Longwei; Chen, Mingzhou; Meng, Yuedong

    2010-09-15

    Due to the toxicity of dioxins, furans and heavy metals, there is a growing environmental concern on municipal solid waste incinerator (MSWI) fly ash in China. The purpose of this study is directed towards the volume-reduction of fly ash without any additive by thermal plasma and recycling of vitrified slag. This process uses extremely high-temperature in an oxygen-starved environment to completely decompose complex waste into very simple molecules. For developing the proper plasma processes to treat MSWI fly ash, a new crucible-type plasma furnace was built. The melting process metamorphosed fly ash to granulated slag that was less than 1/3 of the volume of the fly ash, and about 64% of the weight of the fly ash. The safety of the vitrified slag was tested. The properties of the slag were affected by the differences in the cooling methods. Water-cooled and composite-cooled slag showed more excellent resistance against the leaching of heavy metals and can be utilized as building material without toxicity problems.

  9. Deterioration to extinction of wastewater bacteria by non-thermal atmospheric pressure air plasma as assessed by 16S rDNA-DGGE fingerprinting

    Directory of Open Access Journals (Sweden)

    Wael Samir El-Sayed

    2015-10-01

    Full Text Available The impact of cold atmospheric plasma on the bacterial community structure of wastewater from two different industries was investigated by metagenomic-based PCR-DGGE utilizing 16S rRNA genes. Three doses of atmospheric pressure dielectric barrier discharge plasma were applied to wastewater samples on different time scales. DGGE revealed that the bacterial community gradually changed and overall abundance decreased to extinction upon plasma treatment. The bacterial community in food processing wastewater contained 11 key operational taxonomic units that remained almost completely unchanged when exposed to plasma irradiation at 75.5 mA for 30 or 60s. However, when exposure time was extended to 90s, only Escherichia coli, Coliforms, Aeromonas sp., Vibrio sp., and Pseudomonas putida survived. Only E. coli, Aeromonas sp., Vibrio sp. and P. putida survived treatment at 81.94 mA for 90s. Conversely, all bacterial groups were completely eliminated by treatment at 85.34 mA for either 60 or 90s. Dominant bacterial groups in leather processing wastewater also changed greatly upon exposure to plasma at 75.5 mA for 30 or 60s, with Enterobacter aerogenes, Klebsiella sp., Pseudomonas stutzeri and Acidithiobacillus ferrooxidans being sensitive to and eliminated from the community. At 90s of exposure, all groups were affected except for Pseudomonas sp. and Citrobacter freundii.

  10. Laser-assisted in vitro fertilization facilitates fertilization of vitrified-warmed C57BL/6 mouse oocytes with fresh and frozen-thawed spermatozoa, producing live pups.

    Science.gov (United States)

    Woods, Stephanie E; Qi, Peimin; Rosalia, Elizabeth; Chavarria, Tony; Discua, Allan; Mkandawire, John; Fox, James G; García, Alexis

    2014-01-01

    The utility of cryopreserved mouse gametes for reproduction of transgenic mice depends on development of assisted reproductive technologies, including vitrification of unfertilized mouse oocytes. Due to hardening of the zona pellucida, spermatozoa are often unable to penetrate vitrified-warmed (V-W) oocytes. Laser-assisted in vitro fertilization (LAIVF) facilitates fertilization by allowing easier penetration of spermatozoa through a perforation in the zona. We investigated the efficiency of V-W C57BL/6NTac oocytes drilled by the XYClone laser, compared to fresh oocytes. By using DAP213 for cryoprotection, 83% (1,470/1,762) of vitrified oocytes were recovered after warming and 78% were viable. Four groups were evaluated for two-cell embryo and live offspring efficiency: 1) LAIVF using V-W oocytes, 2) LAIVF using fresh oocytes, 3) conventional IVF using V-W oocytes and 4) conventional IVF using fresh oocytes. First, the groups were tested using fresh C57BL/6NTac spermatozoa (74% motile, 15 million/ml). LAIVF markedly improved the two-cell embryo efficiency using both V-W (76%, 229/298) and fresh oocytes (69%, 135/197), compared to conventional IVF (7%, 12/182; 6%, 14/235, respectively). Then, frozen-thawed C57BL/6NTac spermatozoa (35% motile, 15 million/ml) were used and LAIVF was again found to enhance fertilization efficiency, with two-cell embryo rates of 87% (298/343) using V-W oocytes (P<0.05, compared to fresh spermatozoa), and 73% (195/266) using fresh oocytes. Conventional IVF with frozen-thawed spermatozoa using V-W (6%, 10/168) and fresh (5%, 15/323) oocytes produced few two-cell embryos. Although live offspring efficiency following embryo transfer was greater with conventional IVF (35%, 18/51; LAIVF: 6%, 50/784), advantage was seen with LAIVF in live offspring obtained from total oocytes (5%, 50/1,010; conventional IVF: 2%, 18/908). Our results demonstrated that zona-drilled V-W mouse oocytes can be used for IVF procedures using both fresh and frozen

  11. Laser-assisted in vitro fertilization facilitates fertilization of vitrified-warmed C57BL/6 mouse oocytes with fresh and frozen-thawed spermatozoa, producing live pups.

    Directory of Open Access Journals (Sweden)

    Stephanie E Woods

    Full Text Available The utility of cryopreserved mouse gametes for reproduction of transgenic mice depends on development of assisted reproductive technologies, including vitrification of unfertilized mouse oocytes. Due to hardening of the zona pellucida, spermatozoa are often unable to penetrate vitrified-warmed (V-W oocytes. Laser-assisted in vitro fertilization (LAIVF facilitates fertilization by allowing easier penetration of spermatozoa through a perforation in the zona. We investigated the efficiency of V-W C57BL/6NTac oocytes drilled by the XYClone laser, compared to fresh oocytes. By using DAP213 for cryoprotection, 83% (1,470/1,762 of vitrified oocytes were recovered after warming and 78% were viable. Four groups were evaluated for two-cell embryo and live offspring efficiency: 1 LAIVF using V-W oocytes, 2 LAIVF using fresh oocytes, 3 conventional IVF using V-W oocytes and 4 conventional IVF using fresh oocytes. First, the groups were tested using fresh C57BL/6NTac spermatozoa (74% motile, 15 million/ml. LAIVF markedly improved the two-cell embryo efficiency using both V-W (76%, 229/298 and fresh oocytes (69%, 135/197, compared to conventional IVF (7%, 12/182; 6%, 14/235, respectively. Then, frozen-thawed C57BL/6NTac spermatozoa (35% motile, 15 million/ml were used and LAIVF was again found to enhance fertilization efficiency, with two-cell embryo rates of 87% (298/343 using V-W oocytes (P<0.05, compared to fresh spermatozoa, and 73% (195/266 using fresh oocytes. Conventional IVF with frozen-thawed spermatozoa using V-W (6%, 10/168 and fresh (5%, 15/323 oocytes produced few two-cell embryos. Although live offspring efficiency following embryo transfer was greater with conventional IVF (35%, 18/51; LAIVF: 6%, 50/784, advantage was seen with LAIVF in live offspring obtained from total oocytes (5%, 50/1,010; conventional IVF: 2%, 18/908. Our results demonstrated that zona-drilled V-W mouse oocytes can be used for IVF procedures using both fresh and frozen

  12. Comparison of live-birth defects after luteal-phase ovarian stimulation vs. conventional ovarian stimulation for in vitro fertilization and vitrified embryo transfer cycles.

    Science.gov (United States)

    Chen, Hong; Wang, Yun; Lyu, Qifeng; Ai, Ai; Fu, Yonglun; Tian, Hui; Cai, Renfei; Hong, Qingqing; Chen, Qiuju; Shoham, Zeev; Kuang, Yanping

    2015-05-01

    To assess live-birth defects after a luteal-phase ovarian-stimulation regimen (LPS) for in vitro fertilization (IVF) and vitrified embryo transfer (ET) cycles. Retrospective cohort study. Tertiary-care academic medical center. Infants who were born between January 1, 2013 and May 1, 2014 from IVF with intracytoplasmic sperm injection (ICSI) treatments (n = 2,060) after either LPS (n = 587), the standard gonadotropin-releasing hormone-agonist (GnRH-a) short protocol (n = 1,257), or mild ovarian stimulation (n = 216). The three ovarian-stimulation protocols described and assisted reproductive technology (ART) treatment (IVF or ICSI, and vitrified ET) in ordinary practice. The main measures were: gestational age, birth weight and length, multiple delivery, early neonatal mortality, and birth defects. Associations were assessed using logistic regression by adjusting for confounding factors. The final sample included 2,060 live-born infants, corresponding to 1,622 frozen-thawed (FET) cycles, which led to: 587 live-born infants from LPS (458 FET cycles); 1,257 live-born infants from the short protocol (984 FET cycles); and 216 live-born infants from mild ovarian stimulation (180 FET cycles). Birth characteristics regarding gestational age, birth weight and length, multiple delivery, and early neonatal death were comparable in all groups. The incidence of live-birth defects among the LPS group (1.02%) and the short GnRH-a protocol group (0.64%) was slightly higher than in the mild ovarian-stimulation group (0.46%). However, none of these differences reached statistical significance. For congenital malformations, the risk significantly increased for the infertility-duration factor and multiple births; the adjusted odds ratios were 1.161 (95% confidence interval [CI]: 1.009-1.335) and 3.899 (95% CI: 1.179-12.896), respectively. No associations were found between congenital birth defects and various ovarian-stimulation regimens, maternal age, body mass index, parity

  13. Clinical application of vitrified early human embryos%玻璃化冷冻保存人类早期胚胎的临床应用

    Institute of Scientific and Technical Information of China (English)

    李宜学; 田喜凤; 王晓波; 郭全; 樊桂玲; 刘娜

    2012-01-01

    目的 探讨玻璃化冷冻技术在人类早期胚胎冻存中的临床应用价值.方法 回顾性分析本中心822个冷冻胚胎复苏周期,依据胚胎冷冻方法的不同分为玻璃化冷冻组(490个周期)和程序化冷冻组(332个周期),比较两组胚胎复苏率、复苏胚胎完整率、胚胎种植率、临床妊娠率等数据.结果 玻璃化冷冻复苏组与程序化冷冻复苏组胚胎复苏率分别为98.8%和82.9%,复苏胚胎完整率分别为96.8%和63.1%,胚胎种植率分别为32.0%和18.1%,临床妊娠率分别为53.9%和33.1%,两组数据比较差异均有统计学意义(P<0.05).结论 玻璃化冷冻法比程序化冷冻法更适合于人类早期胚胎的冷冻保存.%Objective To evaluate the clinical application of vitrified human embryos. Methods In the retrospective study, a total of 822 frozen embryos (332 embryos from program freezing and 490 embryos from vitrification freezing) were studied. The rates of embryos survival, blastomere integrity, implantation and clinical pregnancy were compared between the two methods. Results Vitrified embryos had a higher survival rate (98.8% vs 82.9%), blastomere integrity rate (96.8% vs 63.1%), implantation rate (32.0% vs 18.1%) and clinical pregnancy rate (53.9% vs 33.1%) then the program frozen embryos. Conclusion Vitrification is an effective method for cryopreservation of human early embryos.

  14. Advance on non-thermal plasma-photocatalysis technology for air polullant control%低温等离子体-光催化联合技术处理空气污染物的研究进展

    Institute of Scientific and Technical Information of China (English)

    梁文俊; 马琳; 李坚

    2011-01-01

    Non-thermal plasma-photocatalysis technology is a new technology in recent years,which effectively make up for the defects of non-thermal plasma and photocatalysis. The recent research results indicated that the technology was effective for the removal of air pollutants. The basic principles of and advance on non-thermal plasma-photocatalysis technology were introduced and its application prospects were also outlined.%低温等离子体-光催化联合技术是近年来兴起的一项新型技术,它有效弥补了低温等离子体和光催化的缺陷,该技术对空气污染物有较好的去除效果.介绍了低温等离子体-光催化联合技术的基本原理和国内外研究进展,并对该技术的应用前景进行了展望.

  15. Plasma Therapy: An Overview

    Directory of Open Access Journals (Sweden)

    Rajkumar Diwan

    2011-01-01

    Full Text Available Definition: Plasma, the fourth state of matter, is a collection of charged particles (electrons, ions, neutral atoms. Recent demonstration of plasma technology in treatment of living cells, tissue and organs are creating a new field at the intersection of plasma science and technology with biology and medicine known as plasma medicine. Plasma medicine is one of the newest fields of modem applied plasma chemistry. It appeared several years ago and comprises studies concerning the direct action of low-temperature, one atmosphere air plasma (cold plasma/nonthermal plasmalnonequilibrium on body tissues for various noninvasive therapeutic treatments or diagnostics purpose. The study of plasma holds promise for a myriad of applications ranging from lasers and electronics, hazardous decontamination, sterilization and disinfection of foods, soil, water, instruments, to medical uses in wound healing and treating certain types of tumors and cancers. Plasma represents a new state-of-the-art sterilization and disinfection treatment for certain oral and environmental pathogens, heat-sensitive materials, hard and soft surfaces, and may assist health care facilities in the management of various health concerns. The role that low temperature atmospheric pressure plasma (LTAPP could play in the inactivation of pathogenic microorganisms might prove to be a new, faster, more economical alternative.

  16. Removal of ethylene from air stream by adsorption and plasma-catalytic oxidation using silver-based bimetallic catalysts supported on zeolite.

    Science.gov (United States)

    Trinh, Quang Hung; Lee, Sang Baek; Mok, Young Sun

    2015-03-21

    Dynamic adsorption of ethylene on 13X zeolite-supported Ag and Ag-M(x)O(y) (M: Co, Cu, Mn, and Fe), and plasma-catalytic oxidation of the adsorbed ethylene were investigated. The experimental results showed that the incorporation of Ag into zeolite afforded a marked enhancement in the adsorptivity for ethylene. The addition of transition metal oxides was found to have a positive influence on the ethylene adsorption, except Fe(x)O(y). The presence of the additional metal oxides, however, appeared to somewhat interrupt the diffusion of ozone into the zeolite micro-pores, leading to a decrease in the plasma-catalytic oxidation efficiency of the ethylene adsorbed there. Among the second additional metal oxides, Fe(x)O(y) was able to reduce the emission of ozone during the plasma-catalytic oxidation stage while keeping a high effectiveness for the oxidative removal of the adsorbed ethylene. The periodical treatment consisting of adsorption followed by plasma-catalytic oxidation may be a promising energy-efficient ethylene abatement method. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Stabilization/solidification of municipal solid waste incineration fly ash via co-sintering with waste-derived vitrified amorphous slag.

    Science.gov (United States)

    Zhang, Zhikun; Li, Aimin; Wang, Xuexue; Zhang, Lei

    2016-10-01

    Municipal solid waste incineration (MSWI) fly ash (FA) is classified as hazardous waste and requires special treatment prior to landfilling due to its high levels of alkali chlorides and heavy metals. In this paper we presented and discussed a novel method of converting FA into an inert and non-hazardous material, by using the metastable state of vitrified amorphous slag (VAS). XRD results showed that VAS remained in the amorphous state when sintered at 700 and 800°C and were in the crystalline state at 900 and 1000°C. Heavy metals- and Cl-containing phases appeared during phase transformation process. The residual rates of heavy metals and Cl increased with the decrease of FA:VAS ratios. The prolonged leaching test and potential ecological risk assessment of heavy metals showed that the heavy metals were well immobilized into the sintered samples and presented no immediate threat to the environment. The results indicated that the immobilization of heavy metals was due to the reaction with silicate or aluminosilicate matrices within VAS and/or the incorporation into the new generated crystals. The proposed method can be considered as a potential promising technique for the stabilization/solidification of MSWI fly ash with high Cl content.

  18. Culture time of vitrified/warmed zygotes before microinjection affects the production efficiency of CRISPR-Cas9-mediated knock-in mice

    Directory of Open Access Journals (Sweden)

    Yoshiko Nakagawa

    2017-05-01

    Full Text Available Robust reproductive engineering techniques are required for the efficient and rapid production of genetically modified mice. We have reported the efficient production of genome-edited mice using reproductive engineering techniques, such as ultra-superovulation, in vitro fertilization (IVF and vitrification/warming of zygotes. We usually use vitrified/warmed fertilized oocytes created by IVF for microinjection because of work efficiency and flexible scheduling. Here, we investigated whether the culture time of zygotes before microinjection influences the efficiency of producing knock-in mice. Knock-in mice were generated using clustered regularly interspaced short palindromic repeats (CRISPR-CRISPR-associated protein 9 (Cas9 system and single-stranded oligodeoxynucleotide (ssODN or PITCh (Precise Integration into Target Chromosome system, a method of integrating a donor vector assisted by microhomology-mediated end-joining. The cryopreserved fertilized oocytes were warmed, cultured for several hours and microinjected at different timings. Microinjection was performed with Cas9 protein, guide RNA(s, and an ssODN or PITCh donor plasmid for the ssODN knock-in and the PITCh knock-in, respectively. Different production efficiencies of knock-in mice were observed by changing the timing of microinjection. Our study provides useful information for the CRISPR-Cas9-based generation of knock-in mice.

  19. Generation of live offspring from vitrified embryos with synthetic polymers SuperCool X-1000 and SuperCool Z-1000.

    Science.gov (United States)

    Marco-Jimenez, F; Jimenez-Trigos, E; Lavara, R; Vicente, J S

    2014-01-01

    Ice growth and recrystallisation are considered important factors in determining vitrification outcomes. Synthetic polymers inhibit ice formation during cooling or warming of the vitrification process. The aim of this study was to assess the effect of adding commercially available synthetic polymers SuperCool X-1000 and SuperCool Z-1000 to vitrification media on in vivo development competence of rabbit embryos. Four hundred and thirty morphologically normal embryos recovered at 72 h of gestation were used. The vitrification media contained 20% dimethyl sulphoxide and 20% ethylene glycol, either alone or in combination with 1% of SuperCool X-1000 and 1% SuperCool. Our results show that embryos can be successfully vitrified using SuperCool X-1000 and SuperCool Z-1000 and when embryos are transferred, live offspring can be successfully produced. In conclusion, our results demonstrated that we succeeded for the first time in obtaining live offspring after vitrification of embryos using SuperCool X-1000 and SuperCool Z-1000 polymers.

  20. Utilisation de la post-décharge d'un plasma micro-ondes d'air ou d'azote pour valoriser le méthane

    Science.gov (United States)

    Oumghar, A.; Legrand, J. C.; Diamy, A. M.; Turillon, N.; Ben-Aïm, R. I.

    1994-01-01

    Valorization of methane is obtained by means of the reaction with a plasma. The plasma is produced in a quartz tube (30 mm in diameter) crossing a wave guide. The energy is supplied by a generator (Thomson CSF, 2 450 MHz, 15 to 1 500 W). Directional couplers followed by an attenuator and thermistor detectors enable forward Pi_i and reflected Pi_r power to be measured. Methane is introduced in the post-discharge zone through five tubes symmetrically arranged around the reactor. Methane consumption α, selectivity SX and yield RX are measured as a function of the following parameters : β methane/air ratio, F gaz flow, d distance where methane is introduced in the plasma, P pressure, Pi microwave power absorbed by air or nitrogen. It appears that acetylene is the major hydrocarbon obtained. The corresponding selectivity is increased when Pi and P are increased or when d and F are decreased. The optimum value of β is 4/5. If the best experimental conditions are selected, selectivity of total C2 reaches 44 % with a conversion ratio of 80 %. By decreasing methane/air ratio, carbon monoxide yield is increased. The ratio acetylene/ethylene can by varied without changing the conversion ratio, by introducing a catalyst in the post reaction zone. La valorisation du méthane est réalisée dans la post-décharge d'un plasma microondes (2 450 MHz) d'air ou d'azote. Lorsque la décharge est produite dans l'azote, les principaux produits dosés sont l'acétylène, l'éthylène, l'éthane et l'hydrogène. Lorsque la décharge est produite dans l'air, on dose en outre le monoxyde de carbone. Le taux de conversion du méthane ainsi que la sélectivité des produits ont été déterminés en fonction des paramètres expérimentaux suivants : proportion méthane/gaz plasmagène, flux gazeux, distance d'introduction du méthane dans la post-décharge, pression et puissance micro-ondes. Le procédé expérimenté permet d'obtenir des rendements chimiques importants et d'éviter la

  1. Plasma Spray Forming

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    In the course of plasma spray, the plasma jet is comprehensively functioned by such effects as thermal pinch, magnetic pinch and mechanical compression and the flow is jetting at a high speed, the energy is concentrated and its center temperature is so high as to reach upwards of 15 000 ℃ which is capable of melting various kinds of materials inclusive of ceramic, it has a broad applied prospects in the fields of automobile, electronics, telecommunications, medical treatment, air navigation & space navigati...

  2. Plasma Biomedicine in Orthopedics

    Science.gov (United States)

    Hamaguchi, Satsohi

    2012-10-01

    Various effects of plasmas irradiation on cells, tissues, and biomaterials relevant for orthopedic applications have been examined. For direct application of plasmas to living cells or tissues, dielectric barrier discharges (DBDs) with helium flows into ambient air were used. For biomaterial processing, on the other hand, either helium DBDs mentioned above or low-pressure discharges generated in a chamber were used. In this presentation, plasma effects on cell proliferation and plasma treatment for artificial bones will be discussed. First, the conditions for enhanced cell proliferation in vitro by plasma applications have been examined. The discharge conditions for cell proliferation depend sensitively on cell types. Since cell proliferation can be enhanced even when the cells are cultured in a plasma pre-treated medium, long-life reactive species generated in the medium by plasma application or large molecules (such as proteins) in the medium modified by the plasma are likely to be the cause of cell proliferation. It has been found that there is strong correlation between (organic) hydroperoxide generation and cell proliferation. Second, effects of plasma-treated artificial bones made of porous hydroxyapatite (HA) have been examined in vitro and vivo. It has been found that plasma treatment increases hydrophilicity of the surfaces of microscopic inner pores, which directly or indirectly promotes differentiation of mesenchymal stem cells introduced into the pores and therefore causes faster bone growth. The work has been performed in collaboration with Prof. H. Yoshikawa and his group members at the School of Medicine, Osaka University.

  3. Homogeneity testing and quantitative analysis of manganese (Mn) in vitrified Mn-doped glasses by laser-induced breakdown spectroscopy (LIBS)

    Energy Technology Data Exchange (ETDEWEB)

    Unnikrishnan, V. K.; Nayak, Rajesh; Kartha, V. B.; Santhosh, C., E-mail: santhosh.cls@manipal.edu, E-mail: unnikrishnan.vk@manipal.edu [Department of Atomic and Molecular Physics, Manipal University, Manipal (India); Sonavane, M. S. [Nuclear Recycle Board, Bhabha Atomic Research Centre, Mumbai (India); Yeotikar, R. G. [Process Development Division, Bhabha Atomic Research Centre, Mumbai (India); Shah, M. L.; Gupta, G. P.; Suri, B. M. [Laser and Plasma Technology Division, Bhabha Atomic Research Centre, Mumbai (India)

    2014-09-15

    Laser-induced breakdown spectroscopy (LIBS), an atomic emission spectroscopy method, has rapidly grown as one of the best elemental analysis techniques over the past two decades. Homogeneity testing and quantitative analysis of manganese (Mn) in manganese-doped glasses have been carried out using an optimized LIBS system employing a nanosecond ultraviolet Nd:YAG laser as the source of excitation. The glass samples have been prepared using conventional vitrification methods. The laser pulse irradiance on the surface of the glass samples placed in air at atmospheric pressure was about 1.7×10{sup 9} W/cm{sup 2}. The spatially integrated plasma emission was collected and imaged on to the spectrograph slit using an optical-fiber-based collection system. Homogeneity was checked by recording LIBS spectra from different sites on the sample surface and analyzing the elemental emission intensities for concentration determination. Validation of the observed LIBS results was done by comparison with scanning electron microscope- energy dispersive X-ray spectroscopy (SEM-EDX) surface elemental mapping. The analytical performance of the LIBS system has been evaluated through the correlation of the LIBS determined concentrations of Mn with its certified values. The results are found to be in very good agreement with the certified concentrations.

  4. Homogeneity testing and quantitative analysis of manganese (Mn in vitrified Mn-doped glasses by laser-induced breakdown spectroscopy (LIBS

    Directory of Open Access Journals (Sweden)

    V. K. Unnikrishnan

    2014-09-01

    Full Text Available Laser-induced breakdown spectroscopy (LIBS, an atomic emission spectroscopy method, has rapidly grown as one of the best elemental analysis techniques over the past two decades. Homogeneity testing and quantitative analysis of manganese (Mn in manganese-doped glasses have been carried out using an optimized LIBS system employing a nanosecond ultraviolet Nd:YAG laser as the source of excitation. The glass samples have been prepared using conventional vitrification methods. The laser pulse irradiance on the surface of the glass samples placed in air at atmospheric pressure was about 1.7×109 W/cm2. The spatially integrated plasma emission was collected and imaged on to the spectrograph slit using an optical-fiber-based collection system. Homogeneity was checked by recording LIBS spectra from different sites on the sample surface and analyzing the elemental emission intensities for concentration determination. Validation of the observed LIBS results was done by comparison with scanning electron microscope- energy dispersive X-ray spectroscopy (SEM-EDX surface elemental mapping. The analytical performance of the LIBS system has been evaluated through the correlation of the LIBS determined concentrations of Mn with its certified values. The results are found to be in very good agreement with the certified concentrations.

  5. Characteristics of atmospheric pressure air uniform discharge generated by a plasma needle%大气压等离子体针产生空气均匀放电特性研究

    Institute of Scientific and Technical Information of China (English)

    李雪辰; 袁宁; 贾鹏英; 常媛媛; 嵇亚飞

    2011-01-01

    Cold plasma generated by atmospheric air discharge has wide application prospect in industry because it does not need vacuum equipment and mass production is possible.In this paper,a stable uniform discharge is generated in open air by a plasma needle.Discharge mechanism is investigated by optical method,and plasma parameters are given by the spatially resolved measurement of emission spectrum from the discharge.Results show that the discharges have two modes.One is a corona discharge mode and the other is plasma plume mode.In the stable plasma plume mode,a strong emission area and a weak emission one can be distinguished from each other.The development velocity of the weak emission area is much faster than that of the strong emission area.Furthermore,the electron energy and the plasma density in the weak emission area are also bigger than those in the strong emission area.Therefore,the discharge in the strong emission area is dominated by Townsend mechanism,while that in the weak emission area is dominated by streamer discharge.Gas temperature and vibration temperature are also studied in this paper.The experimental results are of great importance to the industrial applications of atmospheric pressure discharge.%大气压空气放电由于脱离了真空装置,易于实现流水线生产,因而在工业上具有广泛的应用.采用等离子体针装置在空气中产生了稳定的大气压均匀放电.利用光谱法对等离子体的相关参数进行了空间分辨率测量,并通过光学方法对放电机理进行了研究.结果表明,等离子体针产生的放电存在电晕放电和等离子体羽放电两种模式.在稳定的等离子体羽放电模式中,发光分为强光区和弱光区.弱光区放电的发展速度远大于强光区的发展速度,电子能量和电子密度均是弱光区比强光区大.对均匀放电的气体温度和振动温度的研究表明,强光区放电遵循汤生击穿机理而弱光区为流光放电.这些结果对

  6. Air Pollution

    Science.gov (United States)

    Air pollution is a mixture of solid particles and gases in the air. Car emissions, chemicals from factories, ... Ozone, a gas, is a major part of air pollution in cities. When ozone forms air pollution, it's ...

  7. 大尺寸大气压空气等离子体射流设备研究%A Large Scale Air Plasma Jet Device at Atmospheric Pressure

    Institute of Scientific and Technical Information of China (English)

    李森; 吴立; 徐凯; 顾璠

    2015-01-01

    A specially designed device to generate large scale plasma jet at atmospheric pressure is reported. The device is a modified dielectric barrier discharge with a high polymer film as dielectric. It is capable of generating a plasma jet with the diameter up to 28 mm and the length up to several tens mm in the surrounding air. There are various excited plasma species shown through optical emission spectrum. The jet temperature is close to room temperature. Therefore, this device may be used for some applications such as the decontamination of temperature-sensitive materials, surface modification, etc.%本文提出了一种特殊的大尺寸大气压空气等离子体射流设备。该设备采用一种高分子耐高温涂料作为介质进行放电,通过气体渐扩通道,产生大尺寸空气等离子体射流,射流直径最宽处可以达到28 mm,长度可以达到数十mm。本文对射流中的活性物质进行光谱测量,同时对射流宏观温度进行测量,指出该射流温度非常接近室温,可以用于温度敏感材料的表面处理等方面。

  8. Air Plasma-Sprayed La2Zr2O7-SrZrO3 Composite Thermal Barrier Coating Subjected to CaO-MgO-Al2O3-SiO2 (CMAS)

    Science.gov (United States)

    Cai, Lili; Ma, Wen; Ma, Bole; Guo, Feng; Chen, Weidong; Dong, Hongying; Shuang, Yingchai

    2017-08-01

    La2Zr2O7-SrZrO3 composite thermal barrier coatings (TBCs) were prepared by air plasma spray (APS). The La2Zr2O7-SrZrO3 composite TBCs covered with calcium-magnesium-aluminum-silicate (CMAS) powder, as well as the powder mixture of CMAS and spray-dried La2Zr2O7-SrZrO3 composite powder, were heat-treated at 1250 °C in air for 1, 4, 8, and 12 h. The phase constituents and microstructures of the reaction products were characterized by x-ray diffraction, scanning electron microscopy, and energy-dispersive spectroscopy. Experimental results showed that the La2Zr2O7-SrZrO3 composite TBCs had higher CMAS resistance than 8YSZ coating. A dense new layer developed between CMAS and La2Zr2O7-SrZrO3 composite TBCs during interaction, and this new layer consisted mostly of apatite (Ca2La8(SiO4)6O2) and c-ZrO2. The newly developed layer effectively protected the La2Zr2O7-SrZrO3 composite TBCs from further CMAS attack.

  9. Plasmachemical degradation of azo dyes by humid air plasma: Yellow Supranol 4 GL, Scarlet Red Nylosan F3 GL and industrial waste.

    Science.gov (United States)

    Abdelmalek, F; Gharbi, S; Benstaali, B; Addou, A; Brisset, J L

    2004-05-01

    A recent non-thermal plasma technique (i.e., a gliding arc discharge which generates reactive species at atmospheric pressure) is tested for pollution abatement of dyes dispersed in synthetic solutions and industrial effluents. Yellow Supranol 4 GL (YS) and Scarlet Red Nylosan F3 GL (SRN) are toxic synthetic dyes widely used in the Algerian textile industry and frequently present in liquid wastes of manufacture plants. Classical removal treatment processes are not efficient enough, so that the presence of dyes in liquid effluents may cause serious environmental problems, in connection with reusing waste waters for irrigation. The degradation processes achieved by the oxidising species formed in the plasma are followed by UV/VIS spectroscopy and by chemical oxygen demand measurements. They are almost complete (i.e., 92.5% for YS and 90% for dilute SRN) and rapidly follow pseudo-first-order laws, with overall estimated rate constants 3 x 10(-4) and 4 x 10(-4)s-1 for YS and SRN, respectively. The degradation rate constant for the industrial mixture (i.e., k = 1.45 x 10(-3)s-1) is a mean value for two consecutive steps (210(-3) and 6 x 10(-5)s-1) measured at the absorption peaks of the major constituent dyes, YS and SRN.

  10. Effect of Gd2O3 on the microstructure and thermal properties of nanostructured thermal barrier coatings fabricated by air plasma spraying

    Institute of Scientific and Technical Information of China (English)

    Yixiong Wang; Chungen Zhou

    2016-01-01

    The nanostructured 4–8 mol% Gd2O3-4.5 mol% Y2O3-ZrO2 (4–8 mol% GdYSZ) coatings were developed by the atmospheric plasma spraying technique. The microstructure and thermal properties of plasma-sprayed 4–8 mol%GdYSZ coatings were investigated. The experimental results indicate that typical mi-crostructure of the as-sprayed coatings were consisted of melted zones, nano-zones, splats, nano-pores, high-volume spheroidal pores and micro-cracks. The porosity of the 4, 6 and 8 mol%GdYSZ coatings was about 9.3%, 11.7%and 13.3%, respectively. It was observed that the addition of gadolinia to the nano-YSZ could significantly reduce the thermal conductivity of nano-YSZ. The thermal conductivity of GdYSZ decreased with increasing Gd2O3 addition. And the reduction in thermal conductivity is mainly attrib-uted to the addition of Gd2O3, which results in the increase in oxygen vacancies, lattice distortion and porosity.

  11. Effect of Gd2O3 on the microstructure and thermal properties of nanostructured thermal barrier coatings fabricated by air plasma spraying

    Directory of Open Access Journals (Sweden)

    Yixiong Wang

    2016-08-01

    Full Text Available The nanostructured 4–8 mol% Gd2O3−4.5 mol% Y2O3-ZrO2 (4–8 mol% GdYSZ coatings were developed by the atmospheric plasma spraying technique. The microstructure and thermal properties of plasma-sprayed 4–8 mol% GdYSZ coatings were investigated. The experimental results indicate that typical microstructure of the as-sprayed coatings were consisted of melted zones, nano-zones, splats, nano-pores, high-volume spheroidal pores and micro-cracks. The porosity of the 4, 6 and 8 mol% GdYSZ coatings was about 9.3%, 11.7% and 13.3%, respectively. It was observed that the addition of gadolinia to the nano-YSZ could significantly reduce the thermal conductivity of nano-YSZ. The thermal conductivity of GdYSZ decreased with increasing Gd2O3 addition. And the reduction in thermal conductivity is mainly attributed to the addition of Gd2O3, which results in the increase in oxygen vacancies, lattice distortion and porosity.

  12. Plasma turbulence

    Energy Technology Data Exchange (ETDEWEB)

    Horton, W. [Univ. of Texas, Austin, TX (United States). Inst. for Fusion Studies; Hu, G. [Globalstar LP, San Jose, CA (United States)

    1998-07-01

    The origin of plasma turbulence from currents and spatial gradients in plasmas is described and shown to lead to the dominant transport mechanism in many plasma regimes. A wide variety of turbulent transport mechanism exists in plasmas. In this survey the authors summarize some of the universally observed plasma transport rates.

  13. Fragmentation process of vitrified ceramic waste (VCW) aiming its incorporation in silico-aluminous refractory concrete for production of refractory bricks; Processo de fragmentacao de residuos ceramicos vitrificados (RCV) visando sua incorporacao em concreto refratario silico-aluminoso

    Energy Technology Data Exchange (ETDEWEB)

    Gomes, L.B.; Brandalise, R.N.; Santos, V. dos, E-mail: lbgomes@ucs.br [Universidade de Caxias do Sul (UCS), RS (Brazil); Bergmann, C.P. [Universidade Federal do Rio Grande do Sul (UFRGS), RS (Brazil)

    2012-07-01

    Ceramic industry generates large amounts of waste, usually disposed in landfills. Reuse could minimize their generation and provides sustainable solutions. However, the energy cost of grinding these waste becomes a hindrance to their reuse. This work aims to obtain particle sizes of vitrified ceramic waste (VCW) using a fast, efficient and low cost fragmentation process as well as its use in refractory concrete. The results shows a wide range of particle size of VCW, which can be used as a promising source of raw material for production of refractory concrete. (author)

  14. Plasma Torch for Plasma Ignition and Combustion of Coal

    Science.gov (United States)

    Ustimenko, Alexandr; Messerle, Vladimir

    2015-09-01

    Plasma-fuel systems (PFS) have been developed to improve coal combustion efficiency. PFS is a pulverized coal burner equipped with arc plasma torch producing high temperature air stream of 4000 - 6000 K. Plasma activation of coal at the PFS increases the coal reactivity and provides more effective ignition and ecologically friendly incineration of low-rank coal. The main and crucial element of PFS is plasma torch. Simplicity and reliability of the industrial arc plasma torches using cylindrical copper cathode and air as plasma forming gas predestined their application at heat and power engineering for plasma aided coal combustion. Life time of these plasma torches electrodes is critical and usually limited to 200 hours. Considered in this report direct current arc plasma torch has the cathode life significantly exceeded 1000 hours. To ensure the electrodes long life the process of hydrocarbon gas dissociation in the electric arc discharge is used. In accordance to this method atoms and ions of carbon from near-electrode plasma deposit on the active surface of the electrodes and form electrode carbon condensate which operates as ``actual'' electrode. Complex physicochemical investigation showed that deposit consists of nanocarbon material.

  15. Comparative analysis on characteristics in non-thermal plasma reactor with oxygen and air%氧气/空气源低温等离子体发生器的性能对比分析

    Institute of Scientific and Technical Information of China (English)

    李小华; 李伟俊; 蔡忆昔; 施蕴曦; 徐辉; 顾林波; 濮晓宇

    2016-01-01

    . As a solution, diesel particular filter (DPF) has become a mainstay in PM control. However, there are some problems with DPF regeneration technologies, such as thermal damage, sulfur poisoning of the catalyst and low regeneration efficiency. So it is meaningful to find out a new regeneration method. Recently, non-thermal plasma (NTP) has become a research focus in the field of diesel emission control with its high efficiency, safety, no secondary pollution and a wide range of application. The active materials, mainly including O3,NO2,OH and O, can start complex chemical reactions, which is impossible in a conventional condition. So, it can be used to remove PM deposits in DPF and realize DPF regeneration. In term of NTP reactor, dielectric barrier discharge is widely used in the laboratory and industry for its simple type, safety and reliability. There are many influence factors concerning discharge, such as discharge voltage and frequency, gas type and flow, materials of barrier and electrode type. In this paper, a coaxial type NTP reactor was designed. In order to have a detailed recognition of NTP reactor, comparative analysis on oxygen and air dielectric discharge were investigated, with the studies on the influence of discharge electrode area (SE), peak-peak voltage (Up-p) and volume flow rate (qv) on discharge power (P), charge flux (Q), ozone concentration, ozone output and ozone output efficiency.SEwas changed by the length of wire tightly wrapped around the barrier,Up-pwas adjusted by a plasma source andqv was controlled by gas valves and flow meters. The results indicated thatSEhad a similar effect both on oxygen and air dielectric discharge. With the increase ofSE,P andQhad a linear growth but there were lower values and growth rate in air discharge. Ozone concentration increased asSE increased while its output efficiency decreased both in oxygen and air discharge.Up-phad remarkably positive impacts onP and Q, both of which had a rising growth rate. Ozone

  16. Plasma harmonics

    CERN Document Server

    Ganeev, Rashid A

    2014-01-01

    Preface; Why plasma harmonics? A very brief introduction Early stage of plasma harmonic studies - hopes and frustrations New developments in plasma harmonics studies: first successes Improvements of plasma harmonics; Theoretical basics of plasma harmonics; Basics of HHG Harmonic generation in fullerenes using few-cycle pulsesVarious approaches for description of observed peculiarities of resonant enhancement of a single harmonic in laser plasmaTwo-colour pump resonance-induced enhancement of odd and even harmonics from a tin plasmaCalculations of single harmonic generation from Mn plasma;Low-o

  17. Production of coloured glass-ceramics from incinerator ash using thermal plasma technology.

    Science.gov (United States)

    Cheng, T W; Huang, M Z; Tzeng, C C; Cheng, K B; Ueng, T H

    2007-08-01

    Incineration is a major treatment process for municipal solid waste in Taiwan. It is estimated that over 1.5 Mt of incinerator ash are produced annually. This study proposes using thermal plasma technology to treat incinerator ash. Sintered glass-ceramics were produced using quenched vitrified slag with colouring agents added. The experimental results showed that the major crystalline phases developed in the sintered glass-ceramics were gehlenite and wollastonite, but many other secondary phases also appeared depending on the colouring agents added. The physical/mechanical properties, chemical resistance and toxicity characteristic leaching procedure of the coloured glass-ceramics were satisfactory. The glass-ceramic products obtained from incinerator ash treated with thermal plasma technology have great potential for building applications.

  18. Understanding Micro Plasmas

    CERN Document Server

    Winter, J; Böke, M; Ellerweg, D; Hemke, T; Knake, N; Mussenbrock, T; Niermann, B; Schröder, D; der Gathen, V Schulz-von; von Keudell, A

    2011-01-01

    Micro plasmas are operated around atmospheric pressure exhibiting pronounced non-equilibrium characteristics, i.e. they possess energetic electrons while ions and neutrals remain cold. They have gained significant interest due to their enormous application potential e.g. in the biomedical, surface modification and light source areas, just to name a few. Many different configurations are in use. Their understanding and quantification is mandatory for further progress in applications. We report on recent progress in the diagnostics and simulation of the entire micro plasma system from gas introduction, via the plasma discharge up to the samples at the example of a plasma jet operated in He/O2 in an ambient air environment.

  19. Aging behavior of Yunnan pine modified by air dielectric barrier discharge cold plasma treatment%DBD冷等离子体处理云南松表面时效性研究

    Institute of Scientific and Technical Information of China (English)

    王洪艳; 杜官本; 韩永国

    2013-01-01

    The surface of Yunnan pine wood was treated by air dielectric barrier discharge (DBD) cold plasma at atmospheric pressure,and the contact angles of the surface with water and diiodomethane for different standing time after treating were tested.The surface free energy and other parameters were calculated according to Young-Good-Girifalco-Fowkes expression.The results showed that after DBD cold plasma treatment the contact angles of treated wood surface decreased prominently and the surface free energy increased,the surface free energy increased by 55% for one hour after treating,however,then it decreased gradually with the time going on.it declined prominently during the period from 9 hours to one day and almost reached the level before treatment after 8 days.%采用空气介质阻挡放电(DBD)冷等离子体改性云南松木材表面,利用水和二碘甲烷测试不同放置时间木材表面接触角,根据Young-Good-Girifalco-Fowkes方程公式计算表面自由能及其色散力和极性力.结果表明,经DBD冷等离子体处理后松木表面接触角明显降低,自由能显著提高,lh后测得表面自由能提高55%;随放置时间的延长表面自由能都逐渐降低,9~24 h内活性降低比较迅速,放置8d后接近于改性前水平.

  20. 铁铝混合粉热喷涂及扩散处理组织分析%Microstructure of Coatings Obtained by Air Plasma Spray of Iron and Aluminium Powders

    Institute of Scientific and Technical Information of China (English)

    闵学刚; 余新泉; 孙扬善; 冯文博; 孙建荣

    2001-01-01

    The coatings of mixed iron aluminides and oxide phases on 18-8 stainless steel substrates were obtained by air plasma spraying mixed powder of iron and aluminium.Microstructures of coatings were investigated by optical microscope,SEM and XRD.The results show that reactions between iron and aluminium sprayed through plasma torch in high speed take place when melted spray of iron and aluminium impinge on the 18-8 stainless steel substrates.Microstructure observations also find the joint of the coatings and substrates is fine and no cracks have been observed.The amount of iron aluminides in coatings increases after the diffusion treatment at 600℃.After the coatings were diffusionally treated at 800℃ and 1000℃,pure Al in coatings disappears completely,but pure Fe still remains,the coatings consist of pure Fe,iron aluminides and oxide phases.%利用等离子喷涂方法在不锈钢基体上喷涂铁铝混合粉获得了铁铝涂层,并对涂层的组织进行了分析。研究结果表明,Fe粉和Al粉熔化后由喷枪高速喷出,沉积在基体上可发生部分化合反应,生成少量的铁铝金属间化合物,涂层与基体结合良好。600℃扩散处理后,涂层中的铁铝金属间化合物增多。800℃和1000℃扩散处理后,Al全部反应,Fe有剩余,涂层由Fe、铁铝金属间化合物和氧化物组成。

  1. 催化型低温等离子体反应器净化废气研究进展%Advances in catalysis non-thermal plasma reactor for air pollution control

    Institute of Scientific and Technical Information of China (English)

    刘跃旭; 王少波; 原培胜; 赵瀛

    2009-01-01

    催化型低温等离子体反应器可有效地提高废气治理的能量效率和净化效果.现有数据表明,在一定能量密度下,催化型低温等离子体反应器比传统低温等离子体反应器能量效率有1.1~12倍的提高,这和污染物种类,反应器构型及催化剂参数有关.本文介绍了反应机理、反应器构型及催化剂参数选择等对反应器性能的影响,并指出今后研究的发展方向.%Catalysis non-thermal plasma reactor has been demonstrated to be effective in improving the energy efficiency and purification for air pollution control. According to the available experimental data, for a given specific energy density, the energy efficiency for gaseous pollutant abatement obtained with catalysis non-thermal plasma reactor could be improved with 1.1-12 times as compared to that of conventional reactors depending on the type of pollutants, reactor geometry and catalyst used. The influences of reaction mechanism, reactor geometry and catalyst parameters on the performance for gaseous pollutant removal are comprehensively discussed, and the further development trend of this technology is proposed.

  2. Optimization of collision/reaction gases for determination of 90Sr in atmospheric particulate matter by inductively coupled plasma tandem mass spectrometry after direct introduction of air via a gas-exchange device

    Science.gov (United States)

    Suzuki, Yoshinari; Ohara, Ryota; Matsunaga, Kirara

    2017-09-01

    Nuclear power plant accidents release radioactive strontium 90 (90Sr) into the environment. Monitoring of 90Sr, although important, is difficult and time consuming because it emits only beta radiation. We have developed a new analytical system that enables real-time analysis of 90Sr in atmospheric particulate matter with an analytical run time of only 10 min. Briefly, after passage of an air sample through an impactor, a small fraction of the sample is introduced into a gas-exchange device, where the air is replaced by Ar. Then the sample is directly introduced into an inductively coupled plasma tandem mass spectrometry (ICP-MS/MS) system equipped with a collision/reaction cell to eliminate isobaric interferences on 90Sr from 90Zr+, 89Y1H+, and 90Y+. Experiments with various reaction gas conditions revealed that these interferences could be minimized under the following optimized conditions: 1.0 mL min- 1 O2, 10.0 mL min- 1 H2, and 1.0 mL min- 1 NH3. The estimated background equivalent concentration and estimated detection limit of the system were 9.7 × 10- 4 and 3.6 × 10- 4 ng m- 3, respectively, which are equivalent to 4.9 × 10- 6 and 1.8 × 10- 6 Bq cm- 3. Recoveries of Sr in PM2.5 measured by real-time analysis compared to those obtained by simultaneously collection on filter was 53 ± 23%, and using this recovery, the detection limit as PM2.5 was estimated to be 3.4 ± 1.5 × 10- 6 Bq cm- 3. That is, this system enabled detection of 90Sr at concentrations < 5 × 10- 6 Bq cm- 3 even considering the insufficient fusion/vaporization/ionization efficiency of Sr in PM2.5.

  3. Plasma on a foundry cupola

    Science.gov (United States)

    Pineau, Didier

    An experiment of a plasma torch on a production foundry cupola is reported. The test runs were conducted on a hot blast cupola, the blast temperature in the absence of plasma being 400 C. With the torch, the temperature of the blast was increased to 1000 C. The experiment was conducted for the manufacture of car engines with a 2.5 MW transportable plasma system. The cupola was boosted with a 4 MW torch and results included an increase in production of 45 percent, a decrease in coke rate and no more new iron in the loads. The plasma torch and hot air cupola furnace are described.

  4. Prooxidant Effects of Verbascoside, a Bioactive Compound from Olive Oil Mill Wastewater, on In Vitro Developmental Potential of Ovine Prepubertal Oocytes and Bioenergetic/Oxidative Stress Parameters of Fresh and Vitrified Oocytes

    Directory of Open Access Journals (Sweden)

    M. E. Dell'Aquila

    2014-01-01

    Full Text Available Verbascoside (VB is a bioactive polyphenol from olive oil mill wastewater with known antioxidant activity. Oxidative stress is an emerging problem in assisted reproductive technology (ART. Juvenile ART is a promising topic because, in farm animals, it reduces the generation gap and, in human reproductive medicine, it helps to overcome premature ovarian failure. The aim of this study was to test the effects of VB on the developmental competence of ovine prepubertal oocytes and the bioenergetic/oxidative stress status of fresh and vitrified oocytes. In fresh oocytes, VB exerted prooxidant short-term effects, that is, catalase activity increase and uncoupled increases of mitochondria and reactive oxygen species (ROS fluorescence signals, and long-term effects, that is, reduced blastocyst formation rate. In vitrified oocytes, VB increased ROS levels. Prooxidant VB effects in ovine prepubertal oocytes could be related to higher VB accumulation, which was found as almost one thousand times higher than that reported in other cell systems in previous studies. Also, long exposure times of oocytes to VB, throughout the duration of in vitro maturation culture, may have contributed to significant increase of oocyte oxidation. Further studies are needed to identify lower concentrations and/or shorter exposure times to figure out VB antioxidant effects in juvenile ARTs.

  5. Picosecond laser filamentation in air

    Science.gov (United States)

    Schmitt-Sody, Andreas; Kurz, Heiko G.; Bergé, Luc; Skupin, Stefan; Polynkin, Pavel

    2016-09-01

    The propagation of intense picosecond laser pulses in air in the presence of strong nonlinear self-action effects and air ionization is investigated experimentally and numerically. The model used for numerical analysis is based on the nonlinear propagator for the optical field coupled to the rate equations for the production of various ionic species and plasma temperature. Our results show that the phenomenon of plasma-driven intensity clamping, which has been paramount in femtosecond laser filamentation, holds for picosecond pulses. Furthermore, the temporal pulse distortions in the picosecond regime are limited and the pulse fluence is also clamped. In focused propagation geometry, a unique feature of picosecond filamentation is the production of a broad, fully ionized air channel, continuous both longitudinally and transversely, which may be instrumental for many applications including laser-guided electrical breakdown of air, channeling microwave beams and air lasing.

  6. Dusty plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Fortov, Vladimir E; Khrapak, Aleksei G; Molotkov, Vladimir I; Petrov, Oleg F [Institute for High Energy Densities, Associated Institute for High Temperatures, Russian Academy of Sciences, Moscow (Russian Federation); Khrapak, Sergei A [Max-Planck-Institut fur Extraterrestrische Physik, Garching (Germany)

    2004-05-31

    The properties of dusty plasmas - low-temperature plasmas containing charged macroparticles - are considered. The most important elementary processes in dusty plasmas and the forces acting on dust particles are investigated. The results of experimental and theoretical investigations of different states of strongly nonideal dusty plasmas - crystal-like, liquid-like, gas-like - are summarized. Waves and oscillations in dusty plasmas, as well as their damping and instability mechanisms, are studied. Some results on dusty plasma investigated under microgravity conditions are presented. New directions of experimental research and potential applications of dusty plasmas are discussed. (reviews of topical problems)

  7. The differences of the outcomes between the fresh and vitrified frozen -thawed embryo transfer in old women%高龄妇女新鲜胚胎和冻融胚胎移植的结局比较

    Institute of Scientific and Technical Information of China (English)

    黄晓卉; 江成龙; 刘美; 张昌军

    2012-01-01

    Objective: To explore the differences of the outcomes between the fresh and vitrified frozen - thawed embryo transfer in old age women. Methods: A retrospective statistical analysis of all clinical cases in which the women who had received IVF or vitrified frozen - thawed embryo transfer were older than 36 - year - old between January 2008 and December 2010, at the Reproductive Medicine Center, Renmin Hospital of Shiyan was performed. Results; In 306 fresh embryo transfer cases (383 cycles) , 90 got pregnancy, so the pregnancy rate is 23. 5% , and no deformed fetus; while in 75 vitrified frozen r thawed embryo transfer cases (94 cycles), 27 got pregnancy, so the pregnancy rate is 28. 72% , and one was deformed fetus ( hydrocephalus) who was given induced labor. The clinical pregnancy rate, the pregnancy rate of multiplets, the plant rate of embryo, the early abortion rate and the ecotopic pregnancy rate between the fresh and vitrified frozen -thawed embryo transfer was not significantly different (P >0.05). Conclusion; Whether the old age women receive the fresh or vitrified frozen - thawed embryo transfer, the clinical pregnancy rate, the pregnancy rate of multiplets , the plant rate of embryo, the early abortion rate and the ecotopic pregnancy rate will not be significantly different. Because the function of old women's ovum and endometrium is descending, increasing the frequency of embryo transfer in limit time to increase accumulative pregnancy rate is suggested.%目的 探讨高龄妇女接受新鲜胚胎和冻融胚胎移植后的结局.方法 对2008年1月~2010年12月期间在我院接受体外受精-胚胎移植和玻璃化冻融胚胎移植的36岁以上的高龄妇女的临床资料进行回顾性分析.结果 新鲜胚胎移植306例,383个周期,90个周期获得妊娠,妊娠率23.5%,无畸形胎儿;玻璃化冻融胚胎移植75例,94个周期,27个周期获得妊娠,妊娠率28.72%,1例畸胎(脑积水),行中孕引产.两

  8. Plasma treatment of onychomycosis

    Science.gov (United States)

    Xiong, Zilan; Roe, Jeff; Grammer, Tim; Him, Yeon-Ho; Graves, David B.

    2015-09-01

    Onychomycosis or fungal infection of the toenail or fingernail is a common affliction. Approximately 10% of the world's adult population is estimated to suffer from onychomycosis. Current treatment options such as topical creams, oral drugs, or laser treatments are generally limited by a variety of problems. We present results for an alternative onychomycosis treatment scheme using atmospheric pressure cold air plasmas. Using thinned cow hoof as a model nail material, we tested the ability of various plasma sources to act through the model nail to eradicate either bacteria or fungus deposited on the opposite side. Following 20 minute exposure to a surface microdischarge (SMD) device operating in room air, we observed a ~ 2 log reduction of E. coli. A similar result was obtained against T. rubrum after 45 min plasma treatment. NOx species concentration penetrating through the model nail as well as uptake into the nail were measured as a function of nail thickness. We propose that these plasma-generated species, or perhaps their reaction products, are responsible for at least part of the observed anti-microbial effect. We also explore the use of ultraviolet light acting in synergy with plasma-generated chemical species.

  9. Microstructure and Wear Behavior of FeCoCrNiMo0.2 High Entropy Coatings Prepared by Air Plasma Spray and the High Velocity Oxy-Fuel Spray Processes

    Directory of Open Access Journals (Sweden)

    Tianchen Li

    2017-09-01

    Full Text Available In the present research, the spherical FeCoCrNiMo0.2 high entropy alloy (HEA powders with a single FCC solid solution structure were prepared by gas atomization. Subsequently, the FeCoCrNiMo0.2 coatings with a different content of oxide inclusions were prepared by air plasma spraying (APS and high-velocity oxy-fuel spraying (HVOF, respectively. The microstructure, phase composition, mechanical properties, and tribological behaviors of these HEA coatings were investigated. The results showed that both HEA coatings showed a typical lamellar structure with low porosity. Besides the primary FCC phase, a mixture of Fe2O3, Fe3O4, and AB2O4 (A = Fe, Co, Ni, and B = Fe, Cr was identified as the oxide inclusions. The oxide content of the APS coating and HVOF coating was calculated to be 47.0% and 12.7%, respectively. The wear resistance of the APS coating was approximately one order of magnitude higher than that of the HVOF coating. It was mainly attributed to the self-lubricated effect caused by the oxide films. The mass loss of the APS coating was mainly ascribed to the breakaway of the oxide film, while the main wear mechanism of the HVOF coating was the abrasive wear.

  10. Infrared Absorption Spectroscopic Study on Reaction between Self-Assembled Monolayers and Atmospheric-Pressure Plasma

    Directory of Open Access Journals (Sweden)

    Masanori Shinohara

    2015-01-01

    Full Text Available Plasma is becoming increasingly adopted in bioapplications such as plasma medicine and agriculture. This study investigates the interaction between plasma and molecules in living tissues, focusing on plasma-protein interactions. To this end, the reaction of air-pressure air plasma with NH2-terminated self-assembled monolayer is investigated by infrared spectroscopy in multiple internal reflection geometry. The atmospheric-pressure plasma decomposed the NH2 components, the characteristic units of proteins. The decomposition is attributed to water clusters generated in the plasma, indicating that protein decomposition by plasma requires humid air.

  11. Plasma waves

    CERN Document Server

    Swanson, DG

    1989-01-01

    Plasma Waves discusses the basic development and equations for the many aspects of plasma waves. The book is organized into two major parts, examining both linear and nonlinear plasma waves in the eight chapters it encompasses. After briefly discussing the properties and applications of plasma wave, the book goes on examining the wave types in a cold, magnetized plasma and the general forms of the dispersion relation that characterize the waves and label the various types of solutions. Chapters 3 and 4 analyze the acoustic phenomena through the fluid model of plasma and the kinetic effects. Th

  12. Plasma astrophysics

    CERN Document Server

    Kaplan, S A; ter Haar, D

    2013-01-01

    Plasma Astrophysics is a translation from the Russian language; the topics discussed are based on lectures given by V.N. Tsytovich at several universities. The book describes the physics of the various phenomena and their mathematical formulation connected with plasma astrophysics. This book also explains the theory of the interaction of fast particles plasma, their radiation activities, as well as the plasma behavior when exposed to a very strong magnetic field. The text describes the nature of collective plasma processes and of plasma turbulence. One author explains the method of elementary

  13. Treatment and recycling of incinerated ash using thermal plasma technology.

    Science.gov (United States)

    Cheng, T W; Chu, J P; Tzeng, C C; Chen, Y S

    2002-01-01

    To treat incinerated ash is an important issue in Taiwan. Incinerated ashes contain a considerable amount of hazardous materials such as dioxins and heavy metals. If these hazardous materials are improperly treated or disposed of, they shall cause detrimental secondary contamination. Thermal plasma vitrification is a robust technology to treat and recycle the ash residues. Under the high temperature plasma environment, incinerated ashes are vitrified into benign slag with large volume reduction and extreme detoxification. Several one-step heat treatment processes are carried out at four temperatures (i.e. 850, 950, 1,050 and 1,150 degrees C) to obtain various "microstructure materials". The major phase to form these materials is a solid solution of gehlenite (Ca2Al2SiO7) and åkermanite (Ca2MgSi2O7) belonging to the melilite group. The physical and mechanical properties of the microstructure materials are improved by using one-step post-heat treatment process after plasma vitrification. These microstructure materials with good quality have great potential to serve as a viable alternative for construction applications.

  14. Factors related to clinical pregnancy after vitrified-warmed embryo transfer: a retrospective and multivariate logistic regression analysis of 2313 transfer cycles.

    Science.gov (United States)

    Shi, Wenhao; Zhang, Silin; Zhao, Wanqiu; Xia, Xue; Wang, Min; Wang, Hui; Bai, Haiyan; Shi, Juanzi

    2013-07-01

    What factors does multivariate logistic regression show to be significantly associated with the likelihood of clinical pregnancy in vitrified-warmed embryo transfer (VET) cycles? Assisted hatching (AH) and if the reason to freeze embryos was to avoid the risk of ovarian hyperstimulation syndrome (OHSS) were significantly positively associated with a greater likelihood of clinical pregnancy. Single factor analysis has shown AH, number of embryos transferred and the reason of freezing for OHSS to be positively and damaged blastomere to be negatively significantly associated with the chance of clinical pregnancy after VET. It remains unclear what factors would be significant after multivariate analysis. The study was a retrospective analysis of 2313 VET cycles from 1481 patients performed between January 2008 and April 2012. A multivariate logistic regression analysis was performed to identify the factors to affect clinical pregnancy outcome of VET. There were 22 candidate variables selected based on clinical experiences and the literature. With the thresholds of α entry = α removal= 0.05 for both variable entry and variable removal, eight variables were chosen to contribute the multivariable model by the bootstrap stepwise variable selection algorithm (n = 1000). Eight variables were age at controlled ovarian hyperstimulation (COH), reason for freezing, AH, endometrial thickness, damaged blastomere, number of embryos transferred, number of good-quality embryos, and blood presence on transfer catheter. A descriptive comparison of the relative importance was accomplished by the proportion of explained variation (PEV). Among the reasons for freezing, the OHSS group showed a higher OR than the surplus embryo group when compared with other reasons for VET groups (OHSS versus Other, OR: 2.145; CI: 1.4-3.286; Surplus embryos versus Other, OR: 1.152; CI: 0.761-1.743) and high PEV (marginal 2.77%, P = 0.2911; partial 1.68%; CI of area under receptor operator characteristic

  15. Effect of composition variations on the long-term wasteform behavior of vitrified domestic waste incineration fly-ash purification residues; Influence des variations de composition des vitrifiats de refiom - residus d'epuration des fumees d'incineration d'ordures menageres - sur leur comportement a long terme

    Energy Technology Data Exchange (ETDEWEB)

    Frugier, P.

    2000-07-01

    The effect of variations in the composition of fly-ash purification residue from incinerated domestic waste on the quality of the containment achieved by vitrification was investigated. Three main factors determine the long-term containment quality: the production of a vitrified wasteform, the occurrence of possible crystallization, and the key parameters of long-term alteration in aqueous media. Each of these aspects is described within a composition range defined by variations in the three major elements. (silicon, calcium and aluminum) and two groups of constituents (alkali metals and toxic elements). The silicon fraction in the fly-ash residue was found to be decisive: it is impossible to obtain a satisfactory vitrified wasteform below a given silicon concentration. Compounds with the lowest silica content also exhibited the greatest tendency to crystallize under the cooling conditions prevailing in industrial processes (the dominant crystallized phase is a melilite that occupies a significant fraction of the material and considerably modifies the alteration mechanisms). The initial alteration rate in pure water and the altered glass thickness measured in a closed system at an advanced stage of the dissolution reaction are both inversely related to the silicon concentration in the glass. Several types of long-term behavior were identified according to the composition range, the process conditions and the vitrified waste disposal scenario. Four distinct 'classes' of vitrified wasteform were defined for direct application in industrial processes. (author)

  16. Research on the Inverter Air-plasma Cutting Machine of LF Contact Pilot Arc%逆变式空气等离子切割机低频引弧技术的研究

    Institute of Scientific and Technical Information of China (English)

    孙强; 刘延明

    2011-01-01

    研制了一种全数字化控制的新型逆变式空气等离子切割机.该等离子机采用非高频的引弧技术,有效地解决了传统技术中存在的高电磁干扰、引弧电路复杂、引弧成功率低等问题.设计以高性能数字信号处理器DSP2812作为主控制芯片,通过理论分析、计算与仿真、控制算法的改进等措施,解决了低频引弧技术中的问题.实验结果表明,该机具有可靠性高、电磁干扰小、一次引弧成功率高等特点.%The digital control system for air-plasma cutting inverter power supply has developed.This cutting machine based on low frequency contact pilot arc and has successfully solved the plenty of short-comings in conventional contact pilot arc technique, such as high electronic magnetic interference (EMI), complex circuit and lower successful ratio of pilot arc and so on.The high performance DSP2812 is utilized as the mainly control chip.By theory analyse, calculate and simulation, the difficulty in low frequency contact pilot arc has been solved.The experimental results verify that the power supply system has higher stability, lower EMI and higher successful ratio of pilot arc.

  17. Comparison of Morphological Microstructure of Vitrified and Normal Shoots of Aronia melanocarpa Elloit%黑果腺肋花楸正常苗与玻璃化苗茎叶显微结构的比较

    Institute of Scientific and Technical Information of China (English)

    高晔华; 利爽; 吕天舒; 胡婷婷; 吴荣哲

    2014-01-01

    The Aronia melanocarpa El oit was used as test material. The microstruc-ture of normal and vitrified shoots and the characteristics of their stomas on leaf surface were compared by paraffin section and leaf epidermis-tearing method. The results showed the palisade tissue of Aronia melanocarpa El oit consists of 2-3 lay-ers of cells. The stomas on lower epidermis cave in, and are smal and dense. There are abundant vessels and sieve tubes in stems. ln contrast, the main veins of vitrified shoots are unobvious, messy and irregular. The boundary between pal-isade tissue and spongy tissue is not obvious. The stomas open circularly and bigly. The stems are swel ing and thick, but the pith parenchyma cells are broken.%以黑果花楸组培苗为试材,采用石蜡切片和叶表皮撕取法,比较正常苗与玻璃化苗茎叶横切面显微结构以及叶表面气孔特征。结果表明,黑果腺肋花楸栅栏组织由2~3层细胞构成,下表皮气孔下陷,小而密集,茎内分布大量导管、筛管。玻璃化苗主脉不明显,细胞排列凌乱不规则,栅栏组织与海绵组织的区别不明显,气孔开口大近圆形,茎肿胀粗大髓腔内薄壁细胞较多、已破裂。

  18. Prehospital Air Medical Plasma (PAMPer) Trial

    Science.gov (United States)

    2015-07-01

    as one of the primary predictors of large volume transfusion requirements. The ABC scoring system consists of 4 non-weighted parameters and include...systems (pulmonary, renal, hepatic , and cardiac), which are evaluated daily throughout the patient’s intensive care unit stay and graded on a scale from 0...umol/L)  160 - 210 211 - 420 > 420 Hepatic Total Bilirubin (umol/L) < 34 34 – 68 69 - 137 > 137 Protocol

  19. Platelet-rich plasma promotes the development of isolated human primordial and primary follicles to the preantral stage.

    Science.gov (United States)

    Hosseini, Laleh; Shirazi, Abolfazl; Naderi, Mohammad Mehdi; Shams-Esfandabadi, Naser; Borjian Boroujeni, Sara; Sarvari, Ali; Sadeghnia, Samaneh; Behzadi, Bahareh; Akhondi, Mohammad Mehdi

    2017-10-01

    This study aimed to assess the effects of platelet-rich plasma (PRP) on growth and survival of isolated early human follicles in a three-dimensional culture system. After fresh and vitrified-warmed ovarian tissue was digested, isolated early preantral follicles and ovarian cells were separately encapsulated in 1% alginate (w/v). The encapsulated follicles and ovarian cells were cultured together in a medium supplemented with foetal bovine serum (FBS), PRP, PRP + FBS, or human serum albumin (HSA) for 10 days. Growth and survival of the follicles were assessed by measurement of diameter and staining with trypan blue. Follicular integrity was assessed by histological analysis. After culturing, all follicles increased in size, but growth rate was greater in follicles isolated from fresh samples than those from vitrified-warmed ones (P media were significantly higher than those of other groups (growth P media supplementation with PRP can better support viability and growth of isolated human early preantral follicles in vitro. Copyright © 2017 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.

  20. Preliminary Study of Thermal Treatment of Coke Wastewater Sludge Using Plasma Torch

    Science.gov (United States)

    Li, Mingshu; Li, Shengli; Sun, Demao; Liu, Xin; Feng, Qiubao

    2016-10-01

    Thermal plasma was applied for the treatment of coke wastewater sludge derived from the steel industry in order to investigate the feasibility of the safe treatment and energy recovery of the sludge. A 30 kW plasma torch system was applied to study the vitrification and gas production of coke wastewater sludge. Toxicity leaching results indicated that the sludge treated via the thermal plasma process converted into a vitrified slag which resisted the leaching of heavy metals. CO2 was utilized as working gas to study the production and heat energy of the syngas. The heating value of the gas products by thermal plasma achieved 8.43 kJ/L, indicating the further utilization of the gas products. Considering the utilization of the syngas and recovery heat from the gas products, the estimated treatment cost of coke wastewater sludge via plasma torch was about 0.98 CNY/kg sludge in the experiment. By preliminary economic analysis, the dehydration cost takes an important part of the total sludge treatment cost. The treatment cost of the coke wastewater sludge with 50 wt.% moisture was calculated to be about 1.45 CNY/kg sludge dry basis. The treatment cost of the coke wastewater sludge could be effectively controlled by decreasing the water content of the sludge. These findings suggest that an economic dewatering pretreatment method could be combined to cut the total treatment cost in an actual treatment process.

  1. Plasma Antenna

    OpenAIRE

    N M Vijay

    2014-01-01

    The fundamental base of plasma antenna is the use of an ionized medium as a conductor. The plasma antenna is a radiofrequency antenna formed by a plasma columns, Filaments or sheets, which are excited by a surface wave. The relevance of this device is how rapidly it can be turned on and off, only applying an electrical pulse. Besides its wide carrier frequency, the great directivity and controllable antenna shape. Otherwise a disadvantage is that it needs energy to be ionized....

  2. Plasma physics

    CERN Document Server

    Drummond, James E

    2013-01-01

    A historic snapshot of the field of plasma physics, this fifty-year-old volume offers an edited collection of papers by pioneering experts in the field. In addition to assisting students in their understanding of the foundations of classical plasma physics, it provides a source of historic context for modern physicists. Highly successful upon its initial publication, this book was the standard text on plasma physics throughout the 1960s and 70s.Hailed by Science magazine as a ""well executed venture,"" the three-part treatment ranges from basic plasma theory to magnetohydrodynamics and microwa

  3. Plasma Modeling of Electrosurgery

    Science.gov (United States)

    Jensen, Scott; Friedrichs, Daniel; Gilbert, James; Park, Wounjhang; Maksimovic, Dragan

    2014-10-01

    Electrosurgery is the use of high frequency alternating current (AC) to illicit a clinical response in tissue, such as cutting or cauterization. Power electronics converters have been demonstrated to generate the necessary output voltage and current for electrosurgery. The design goal of the converter is to regulate output power while supplying high frequency AC. The design is complicated by fast current and voltage transients that occur when the current travels through air in the form of an arc. To assist in designing a converter that maintains the desired output power during these transients, we have used the COMSOL Plasma Module to determine the output voltage and current characteristics during an arc. This plasma model, used in conjunction with linear circuit elements, allows the full electrosurgical system to be validated. Two models have been tested with the COMSOL Plasma Module. One is a four-species, four-reaction model based on the local field approximation technique. The second simulates the underlying air chemistry using 30 species, 151 chemical reactions, and a coupled electron energy distribution function. Experimental output voltage and current samples have been collected and compared to both models.

  4. Plasma-Assisted Pretreatment of Wheat Straw

    DEFF Research Database (Denmark)

    Schultz-Jensen, Nadja; Leipold, Frank; Bindslev, Henrik

    2011-01-01

    O3 generated in a plasma at atmospheric pressure and room temperature, fed with dried air (or oxygen-enriched dried air), has been used for the degradation of lignin in wheat straw to optimize the enzymatic hydrolysis and to get more fermentable sugars. A fixed bed reactor was used combined with ...

  5. Picosecond laser filamentation in air

    CERN Document Server

    Schmitt-Sody, Andreas; Bergé, L; Skupin, S; Polynkin, Pavel

    2016-01-01

    The propagation of intense picosecond laser pulses in air in the presence of strong nonlinear self-action effects and air ionization is investigated experimentally and numerically. The model used for numerical analysis is based on the nonlinear propagator for the optical field coupled with the rate equations for the production of various ionic species and plasma temperature. Our results show that the phenomenon of plasma-driven intensity clamping, which is paramount in femtosecond laser filamentation, holds for picosecond pulses. Furthermore, the temporal pulse distortions are limited and the pulse fluence is also clamped. The resulting unique feature of the picosecond filamentation regime is the production of a broad, fully ionized air channel, continuous both longitudinally and transversely, which may be instrumental for numerous applications.

  6. Live births achieved via IVF are increased by improvements in air quality and laboratory environment

    Science.gov (United States)

    Heitmann, Ryan J; Hill, Micah J; James, Aidita N; Schimmel, Tim; Segars, James H; Csokmay, John M; Cohen, Jacques; Payson, Mark D

    2016-01-01

    Infertility is a common disease, which causes many couples to seek treatment with assisted reproduction techniques. Many factors contribute to successful assisted reproduction technique outcomes. One important factor is laboratory environment and air quality. Our facility had the unique opportunity to compare consecutively used, but separate assisted reproduction technique laboratories, as a result of a required move. Environmental conditions were improved by strategic engineering designs. All other aspects of the IVF laboratory, including equipment, physicians, embryologists, nursing staff and protocols, were kept constant between facilities. Air quality testing showed improved air quality at the new IVF site. Embryo implantation (32.4% versus 24.3%; P < 0.01) and live birth (39.3% versus 31.8%, P < 0.05) were significantly increased in the new facility compared with the old facility. More patients met clinical criteria and underwent mandatory single embryo transfer on day 5 leading to both a reduction in multiple gestation pregnancies and increased numbers of vitrified embryos per patient with supernumerary embryos available. Improvements in IVF laboratory conditions and air quality had profound positive effects on laboratory measures and patient outcomes. This study further strengthens the importance of the laboratory environment and air quality in the success of an IVF programme. PMID:26194882

  7. Investigation of plasma-aided bituminous coal gasification

    Energy Technology Data Exchange (ETDEWEB)

    Matveev, I.B.; Messerle, V.E.; Ustimenko, A.B. [Applied Plasma Technology, Mclean, VA (United States)

    2009-04-15

    This paper presents thermodynamic and kinetic modeling of plasma-aided bituminous coal gasification. Distributions of concentrations, temperatures, and velocities of the gasification products along the gasifier are calculated. Carbon gasification degree, specific power consumptions, and heat engineering characteristics of synthesis gas at the outlet of the gasifier are determined at plasma air/steam and oxygen/steam gasification of Powder River Basin bituminous coal. Numerical simulation showed that the plasma oxygen/steam gasification of coal is a more preferable process in comparison with the plasma air/steam coal gasification. On the numerical experiments, a plasma vortex fuel reformer is designed.

  8. Dielectric Barrier Discharge Air Plasma at Atmospheric Pressure Induced Oxidative Stress in Saccharomyces cerevisiae%大气压介质阻挡放电空气等离子体引起酿酒酵母氧化应激的研究

    Institute of Scientific and Technical Information of China (English)

    陈慧黠; 修志龙; 白凤武

    2013-01-01

    在产生等离子体的过程中会同时产生大量的自由基和准分子.作者研究了经大气压介质阻挡放电(dielectric barrier discharge,DBD)空气等离子体处理后酿酒酵母(Saccharomyce cerevisiae)细胞的氧化应激,发现酿酒酵母细胞在DBD空气等离子体处理后,胞内总抗氧化能力和谷胱甘肽还原酶活力都不同程度被激活,丙二醛含量也随处理时间的延长不断增加,胞内活性氧(reactive oxygen species,ROS)含量明显增加,细胞周期也出现严重的G1期阻滞,说明等离子体产生的大量自由基可引发酵母细胞的氧化应激.%Atmospheric pressure dielectric barrier discharge (DBD) air plasma is a source of reactive species,such as OH*,H*,O*,H2O2,O3,etc.The oxidative stress in Saccharomyces cerevisiae which was exposed to DBD air plasma at atmospheric pressure was studied.It was showed that the intracellular total antioxidant capability (T-AOC) and activity of glutathione reductase (GR) were activated,malondialdehyde (MDA) content increased in a treatment time-dependent manner,intracellular reactive oxygen species (ROS) content increased,and cell cycle arrested in G1 phase significantly.It was proved that oxidative stress was induced in S.cerevisiae when the cells were exposed to DBD air plasma.

  9. Vacuum plasma spray coating

    Science.gov (United States)

    Holmes, Richard R.; Mckechnie, Timothy N.

    1989-01-01

    Currently, protective plasma spray coatings are applied to space shuttle main engine turbine blades of high-performance nickel alloys by an air plasma spray process. Originally, a ceramic coating of yttria-stabilized zirconia (ZrO2.12Y2O3) was applied for thermal protection, but was removed because of severe spalling. In vacuum plasma spray coating, plasma coatings of nickel-chromium-aluminum-yttrium (NiCrAlY) are applied in a reduced atmosphere of argon/helium. These enhanced coatings showed no spalling after 40 MSFC burner rig thermal shock cycles between 927 C (1700 F) and -253 C (-423 F), while current coatings spalled during 5 to 25 test cycles. Subsequently, a process was developed for applying a durable thermal barrier coating of ZrO2.8Y2O3 to the turbine blades of first-stage high-pressure fuel turbopumps utilizing the enhanced NiCrAlY bond-coating process. NiCrAlY bond coating is applied first, with ZrO2.8Y2O3 added sequentially in increasing amounts until a thermal barrier coating is obtained. The enchanced thermal barrier coating has successfully passed 40 burner rig thermal shock cycles.

  10. The analysis of the clinical outcome of 1658 vitrified cryopreservation and thawing cycles%1658例玻璃化冻融周期的临床结局分析

    Institute of Scientific and Technical Information of China (English)

    伍琼芳; 丁涛; 胡毅娜; 黄志辉; 辛才林; 朱元

    2014-01-01

    目的:探索应用玻璃化冻融技术冻融卵裂期胚胎及囊胚的临床效果。方法来源于江西省妇幼保健院生殖中心2012年9月至2014年1月1658例玻璃化冻融移植周期(其中卵裂期胚胎1426周期共2907枚胚胎,囊胚232周期共341枚胚胎),用自制麦管作为胚胎载体及相同的玻璃化方法进行冷冻、复苏,及胚胎移植,观察其复苏存活率、全胚融解率、临床妊娠率、植入率和流产率等。结果卵裂期胚胎复苏率为98.5%,全胚融解率是0.35%。囊胚复苏率为99.7%,全胚融解率是0.43%。卵裂期胚胎的胚胎植入率显著低于囊胚(35.4%vs 49.3%)(P0.05,双胎率卵裂期胚胎显著高于囊胚(38.3%vs 28.9%)(P0.05)。结论使用相同的玻璃化冷冻方法对人类卵裂期胚胎和囊胚可获得理想的冷冻效果。%Objective To evaluate the efficacy of vitrified cryopreservation for human embryos in cleavage and blastocyst stages using cryoloop. Methods 1658 vitrified cryopreservation and thawing cycles (1426 cycles including 290,7 embryos in cleavage and 232 cycles including 341 embryos in blastocyst stage respectively),from the hospital IVF center,were divided into two groups,as their stages,I. e. cleavage or blastocyst stage,for the later artifical shrinked must be done prior to be freezed,and then rates for thawing survival,implantation,clinic pregnancy and miscarrage were observed. Results The rates of the thawing survival of the cleavage and blastocyst stage embryos were (98.5%,99.7%) respectively. The rates for implantation and the mean transfer embryo number of the two groups were 35.4%,49.3%,and 2.0±0.3,1.5±0.5 (P<0.05). while their clinical pregnancy rates and miscarryge rates were not significantly different (50.7%vs 55.4%,6.8%vs 7.8%). Conclusion This protocol for vitrified cry-opreservation,can work well and suitable for cleavage stage embryos and blastocyst stage embryos as well.

  11. Antitumor action of non thermal plasma sources, DBD and Plasma Gun, alone or in combined protocols

    Science.gov (United States)

    Robert, Eric; Brullé, Laura; Vandamme, Marc; Riès, Delphine; Le Pape, Alain; Pouvesle, Jean-Michel

    2012-10-01

    The presentation deals with the assessment on two non thermal plasma sources developed and optimized for oncology applications. The first plasma source is a floating-electrode dielectric barrier discharge powered at a few hundreds of Hz which deliver air-plasma directly on the surface of cell culture medium in dishes or on the skin or organs of mice bearing cancer tumors. The second plasma source, so called Plasma Gun, is a plasma jet source triggered in noble gas, transferred in high aspect ratio and flexible capillaries, on targeting cells or tumors after plasma transfer in air through the ``plasma plume'' generated at the capillary outlet. In vitro evidence for massive cancer cell destruction and in vivo tumor activity and growth rate reductions have been measured with both plasma sources. DNA damages, cell cycle arrests and apoptosis induction were also demonstrated following the application of any of the two plasma source both in vitro and in vivo. The comparison of plasma treatment with state of the art chemotherapeutic alternatives has been performed and last but not least the benefit of combined protocols involving plasma and chemotherapeutic treatments has been evidenced for mice bearing orthotopic pancreas cancer and is under evaluation for the colon tumors.

  12. 膨胀玻化微珠保温砂浆性能检测影响因素及施工现场质量控制%The Performance Testing Influence Factors and Quality Control in the Construction Site of the Expansion Vitrified Beads Insulation Mortar

    Institute of Scientific and Technical Information of China (English)

    岳婷

    2014-01-01

    The expansion vitrified beads insulation mortar is a new type thermal insulation building material, which has the advantages of high construction efficiency, stable quality, and new materials, etc. This article discusses the vitrified beads in-sulation mortar performance influence factors and construction quality control.%膨胀玻化微珠保温砂浆是一种新兴的保温型建筑材料,具有施工效率高、质量稳定、材料新颖等方面的优点。文章对膨胀玻化微珠保温砂浆性能检测影响因素和施工现场质量控制进行了探讨。

  13. Treatment of mixed wastes by thermal plasma discharges; Tratamiento de desechos mixtos por descargas de plasma termico

    Energy Technology Data Exchange (ETDEWEB)

    Diaz A, L.V.; Pacheco S, J.O.; Pacheco P, M.; Monroy G, F.; Emeterio H, M. [ININ, 52750 La Marquesa, Estado de Mexico (Mexico)]. e-mail: lauradiazarch@yahoo.com.mx

    2007-07-01

    The National Institute of Nuclear Research (ININ) uses an ion exchange resin: IRN 150 (copolymer styrene Divynilbencene) in the TRIGA Mark III reactor to absorb polluted particles with heavy metals and radioactive particles of low level. Once the capacity of filtrate of the resin is exceeded, it is replaced and considered with a mixed waste. This work is based on taking advantage of the advantages of the technique of the thermal plasma in a unique process: (high energy density 105W/cm{sup 3} high enthalpy, high reactivity chemical, high operation temperatures 6000-11500K and quick quenching 106K/s) for the degradation and vitrification of the resin IRN 150. The reactor of plasma is compact and it works to atmospheric pressure and reduced thermal inertia. Therefore, the main parameters involved during the degradation tests and vitrification are: plasma current, voltage, gas flow and distance among the electrodes. The used vitreous matrix, is obtained from a ceramic clay composed by an oxides mixture which are characterized by their good resistance to mechanical impacts and erosion caused by the water. The ceramic clay and the resin IRN 150 were analyzed before the treatment by Scanning Electron Microscopy (MEB), X-ray Diffraction (DRX), Thermal gravimetry (TGA) once vitrified the materials were also analyzed by MEB and DRX. It is obtained as a result that the material more appropriate to be used as vitreous matrix it is a ceramic clay formed by several oxides, being operated the plasma system with a current of 115A, voltage of 25V, flow of the argon gas of 5 l/m and a distance among electrodes of 10mm. With the development of the proposed technology and the material for the vitreous matrix, be rotted to try in a future a great variety of mixed waste. (Author)

  14. 人卵裂胚和囊胚的玻璃化冷冻及临床应用%Vitrified cryopreservation for human embryoes in cleavage or blastocyst stage and its preliminarily applications in clinic

    Institute of Scientific and Technical Information of China (English)

    孙迎利; 张敏; 常秀峰; 张建平; 朱爱萍; 马晓伟; 余裕炉

    2011-01-01

    Objective: To evaluate the efficacy of vitrified cryopreservation for human embryos in cleavage and blastocyst stages using cryoloop. Methods: 270 embryos ( 167 and 103 in cleavage and blastocyst stage respectively), from the hospital IVF center,were divided into two groups, as their stages, I. e. cleavage or blastocyst stage, for the later artifical shrinked must be done prior to be freezed, and then rates for thawing survival, implantation, clinic pregnancy and miscarrage were observed. Results: 97.0%,33. 1%, 42. 9%, 13. 3% and 96. 1%, 43.9%, 52%, 15.4%; in rates mentioned above, were observed in 70 and 75 transfer cycles, respectively for cleavage and blastocyst stage embryos. Conclusion: This protocol for vitrified cryopreservation, using cryoloop, can work well and suitable for cleavage stage embryos and blastocyst stage embryos as well.%目的 探索人卵裂胚及囊胚玻璃化冷冻的有效性.方法 来源于生殖中心IVF或ICSI助孕的共270个胚胎(卵裂胚167个.囊胚103个),用Cryoloop作为胚胎载体和相同的玻璃化方法进行冷冻、复苏和移植,观察其复苏存活率、临床妊娠率、植入率和流产率.结果 卵裂胚和囊胚的复苏率、植入率和妊娠率分别为97.0%、33.1%、42.9%和96.1%、43.9%、52%,流产率分别为13.3%和15.4%.结论 以Cryoloop为胚胎载体,使用相同的玻璃化冷冻方法对人类卵裂胚和囊胚均可获得同样理想的冷冻效果和临床结局.

  15. Microwave plasma combustion of coal

    Energy Technology Data Exchange (ETDEWEB)

    P.M. Kanilo; V.I. Kazantsev; N.I. Rasyuk; K. Schuenemann; D.M. Vavriv [Institute of Machine Building Problems of the National Academy of Sciences of Ukraine, Kharkov (Ukraine)

    2003-01-01

    Microwave plasma is studied as an alternative to oil or gas fuel for ignition and stabilisation of burning of lean coal. The study is performed on an experimental set-up, which includes a burner with a microwave plasma generator, coal and air supply systems, and measurement equipment. Power and thermochemical characteristics of the coal-plasma interaction have been measured and analysed. The obtained results indicate an essential intensification of ignition and combustion processes in the microwave burner compared to those in conventional burners. In particular, it has been demonstrated that the microwave energy consumption is only about 10% of the required expenditure of oil or gas, measured in heat equivalent. A design of an industrial microwave-plasma burner is proposed. Prospects of such burner for applications at industrial boilers of power plants are discussed. 6 refs., 4 figs., 2 tabs.

  16. Plasma chromograninx

    DEFF Research Database (Denmark)

    Goetze, Jens P; Hilsted, Linda M; Rehfeld, Jens F

    2014-01-01

    Cardiovascular risk assessment remains difficult in elderly patients. We examined whether chromogranin A (CgA) measurement in plasma may be valuable in assessing risk of death in elderly patients with symptoms of heart failure in a primary care setting. A total of 470 patients (mean age 73 years......) were followed for 10 years. For CgA plasma measurement, we used a two-step method including a screening test and a confirmative test with plasma pre-treatment with trypsin. Cox multivariable proportional regression and receiver-operating curve (ROC) analyses were used to assess mortality risk...... of follow-up showed significant additive value of CgA confirm measurements compared with NT-proBNP and clinical variables. CgA measurement in the plasma of elderly patients with symptoms of heart failure can identify those at increased risk of short- and long-term mortality....

  17. Plasma Cleaning

    Science.gov (United States)

    Hintze, Paul E.

    2016-01-01

    NASA's Kennedy Space Center has developed two solvent-free precision cleaning techniques: plasma cleaning and supercritical carbon dioxide (SCCO2), that has equal performance, cost parity, and no environmental liability, as compared to existing solvent cleaning methods.

  18. Plasma confinement

    CERN Document Server

    Hazeltine, R D

    2003-01-01

    Detailed and authoritative, this volume examines the essential physics underlying international research in magnetic confinement fusion. It offers readable, thorough accounts of the fundamental concepts behind methods of confining plasma at or near thermonuclear conditions. Designed for a one- or two-semester graduate-level course in plasma physics, it also represents a valuable reference for professional physicists in controlled fusion and related disciplines.

  19. Hollow-Cathode Source Generates Plasma

    Science.gov (United States)

    Deininger, W. D.; Aston, G.; Pless, L. C.

    1989-01-01

    Device generates argon, krypton, or xenon plasma via thermionic emission and electrical discharge within hollow cathode and ejects plasma into surrounding vacuum. Goes from cold start up to full operation in less than 5 s after initial application of power. Exposed to moist air between operations without significant degradation of starting and running characteristics. Plasma generated by electrical discharge in cathode barrel sustained and aided by thermionic emission from emitter tube. Emitter tube does not depend on rare-earth oxides, making it vulnerable to contamination by exposure to atmosphere. Device modified for use as source of plasma in laboratory experiments or industrial processes.

  20. Air Cleaning Technologies

    Science.gov (United States)

    2005-01-01

    to remove airborne pathogens from room air depends on several factors, including the airflow rate through the unit’s filter and the airflow patterns in the room. Tested under a variety of conditions, in-room air cleaners, including portable or ceiling mounted units with either a HEPA or a non-HEPA filter, portable units with UVGI lights only, or ceiling mounted units with combined HEPA filtration and UVGI lights, have been estimated to be between 30% and 90%, 99% and 12% and 80% effective, respectively. However, and although their effectiveness is variable, the United States Centers for Disease Control and Prevention has acknowledged in-room air cleaners as alternative technology for increasing room ventilation when this cannot be achieved by the building’s HVAC system with preference given to fixed recirculating systems over portable ones. Importantly, the use of an in-room air cleaner does not preclude either the need for health care workers and visitors to use personal protective equipment (N95 mask or equivalent) when entering AII rooms or health care facilities from meeting current regulatory requirements for airflow rates (ventilation rates) in buildings and airflow differentials for effective negative-pressure rooms. The Plasmacluster ion technology, developed in 2000, is an air purification technology. Its manufacturer, Sharp Electronics Corporation, says that it can disable airborne microorganisms through the generation of both positive and negative ions. (1) The functional unit is the hydroxyl, which is a molecule comprised of one oxygen molecule and one hydrogen atom. Plasmacluster ion air purifier uses a multilayer filter system composed of a prefilter, a carbon filter, an antibacterial filter, and a HEPA filter, combined with an ion generator to purify the air. The ion generator uses an alternating plasma discharge to split water molecules into positively and negatively charged ions. When these ions are emitted into the air, they are surrounded by

  1. Cold plasma decontamination of foods.

    Science.gov (United States)

    Niemira, Brendan A

    2012-01-01

    Cold plasma is a novel nonthermal food processing technology that uses energetic, reactive gases to inactivate contaminating microbes on meats, poultry, fruits, and vegetables. This flexible sanitizing method uses electricity and a carrier gas, such as air, oxygen, nitrogen, or helium; antimicrobial chemical agents are not required. The primary modes of action are due to UV light and reactive chemical products of the cold plasma ionization process. A wide array of cold plasma systems that operate at atmospheric pressures or in low pressure treatment chambers are under development. Reductions of greater than 5 logs can be obtained for pathogens such as Salmonella, Escherichia coli O157:H7, Listeria monocytogenes, and Staphylococcus aureus. Effective treatment times can range from 120 s to as little as 3 s, depending on the food treated and the processing conditions. Key limitations for cold plasma are the relatively early state of technology development, the variety and complexity of the necessary equipment, and the largely unexplored impacts of cold plasma treatment on the sensory and nutritional qualities of treated foods. Also, the antimicrobial modes of action for various cold plasma systems vary depending on the type of cold plasma generated. Optimization and scale up to commercial treatment levels require a more complete understanding of these chemical processes. Nevertheless, this area of technology shows promise and is the subject of active research to enhance efficacy.

  2. Air Pollution

    Science.gov (United States)

    ... to view this content or go to source URL . What NIEHS is Doing on Air Pollution Who ... Junction Last Reviewed: February 06, 2017 This page URL: NIEHS website: https://www.niehs.nih.gov/ Email ...

  3. Experimental characterization of an argon laminar plasma jet at atmospheric pressure

    Energy Technology Data Exchange (ETDEWEB)

    Langlois-Bertrand, Emilie; De Izarra, Charles, E-mail: charles.de_izarra@univ-orleans.fr [Groupe de Recherche sur l' Energetique des Milieux Ionises, UMR6606 Universite d' Orleans - CNRS, Faculte des Sciences, Site de Bourges, rue Gaston Berger, BP 4043, 18028 BOURGES Cedex (France)

    2011-10-19

    This paper deals with a dc laminar pure argon plasma jet operating at atmospheric pressure in ambient air that was experimentally studied in order to obtain temperature and velocity. Plasma jet temperature was evaluated by optical emission spectroscopy and the plasma jet velocity was determined by various methods using a pressure sensor. It is shown that the maximum plasma jet temperature is 15 000 K and the maximum plasma jet velocity is 250 m s{sup -1} at the plasma jet centre. Finally, a study of the ambient air amount entrained into the plasma jet is presented.

  4. Fundamentals of gas phase plasmas for treatment of human tissue.

    Science.gov (United States)

    Kushner, Mark J; Babaeva, Natalia Yu

    2011-01-01

    The use of gas phase plasmas for treating human tissue is at the intersection of two disciplines - plasma physics and engineering, and medicine. In this paper, a primer will be provided for the medical practitioner on the fundamentals of generating gas phase plasmas at atmospheric pressure in air for the treatment of human tissue. The mechanisms for gas phase plasmas interacting with tissue and biological fluids will also be discussed using results from computer modeling.

  5. LASER PLASMA AND LASER APPLICATIONS: Plasma transparency in laser absorption waves in metal capillaries

    Science.gov (United States)

    Anisimov, V. N.; Kozolupenko, A. P.; Sebrant, A. Yu

    1988-12-01

    An experimental investigation was made of the plasma transparency to heating radiation in capillaries when absorption waves propagated in these capillaries as a result of interaction with a