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Sample records for implantados por plasma

  1. Titanium and aluminium ions implanted by plasma on polyethylene; lones de titanio y aluminio implantados por plasma sobre polietileno

    Energy Technology Data Exchange (ETDEWEB)

    Cruz, G.J.; Olayo, M.G.; Lopez, R.; Granda, E.; Munoz, A.; Valencia, R. [ININ, 52750 La Marquesa, Estado de Mexico (Mexico); Morales, J. [UAM-I, Apdo. Postal 5534, Iztapalapa, D.F. (Mexico)]. e-mail: gcc@nuclear.inin.mx

    2007-07-01

    The ion implantation by plasma of titanium and aluminum on polyethylene thin films (PE) is presented. The results indicate that the polymers reacted firstly with the oxygen and/or nitrogen carrying gases, and later its received the metallic particles that formed thin films. The stainless steel and the titanium formed a single phase. The metallic layers grew in the interval of 1 to 2 nm/min, its are thin, but enough to change the hardness of the polymer that it is increased in more of 20 times. (Author)

  2. Deformidad facial postraumática asociada a complicación por silastic orbitario 35 años después de implantado

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    Denia Morales Navarro

    Full Text Available Las alteraciones esqueléticas del macizo facial sin tratamiento quirúrgico o con un manejo inadecuado, pueden resultar en deformidad secundaria importante con implicaciones estéticas y funcionales que deben ser consideradas para su tratamiento. El objetivo de esta presentación fue caracterizar el caso de deformidad facial postraumática asociada a complicación por silastic orbitario, 35 años después de implantado este. Se trata de un paciente masculino de 67 años que refirió haber sido tratado al presentar enrojecimiento de un ojo y secreciones. Refiere que hace 35 años fue intervenido quirúrgicamente por fractura “en la zona del ojo izquierdo”, que le colocaron silastic, y que no había tenido problemas hasta el momento en esa área. En el examen físico facial se detectó asimetría facial: ligero enoftalmo del ojo izquierdo, con desnivel pupilar, disminución de la apertura palpebral, rasgo antimongoloide, con eritema de la conjuntiva, quémosis, y abundantes secreciones. Se comprobó limitación del movimiento súpero-externo. Se corrobora la presencia de una fístula en el fondo de saco del párpado inferior. Se diagnostica como deformidad facial postraumática complicada por reacción a cuerpo extraño (al silastic. Fue intervenido quirúrgicamente y se realizó la exéresis del material, y la reconstrucción de la antomía ausente en la zona con malla de titanio. Se obtuvo excelentes resultados. Las lesiones postraumáticas de la cara se asocian generalmente con grandes secuelas funcionales y estéticas. Si se añaden las complicaciones por el empleo de implantes de biomateriales, la determinación de la conducta terapéutica puede ser un reto.

  3. Deposição por plasma com arco transferido Hardfacing by plasma transfer arc process

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    Víctor Vergara Díaz

    2010-03-01

    Full Text Available Em virtude do Processo de Soldagem Plasma com Alimentação de Pó ter similaridades com o Processo de Soldagem Plasma com Alimentação de Arame, foi realizado um estudo comparativo entre ambos os processos utilizando-se a liga a base de cobalto comercialmente conhecida como Stellite 6, como material de adição na forma de pó e arame. A pesquisa foi realizada com a expectativa de ser aplicada nas operações de revestimentos de superfícies, em especial em pás de turbinas hidráulicas desgastadas por cavitação. A seleção do material de adição a ser empregado depende da natureza do mecanismo de desgaste encontrado. No Labsolda, a liga Stellite 6 vem sendo uma das mais utilizadas, por apresentar uma excelente resistência ao desgaste erosivo por cavitação. Foi avaliada a influência da vazão de gás de plasma a partir dos valores de diluição, dimensões do cordão, dureza e microestrutura. O Processo de Soldagem Plasma com Alimentação de Pó foi o que produziu o melhor acabamento superficial, menor diluição, melhor molhamento e maior largura. Com isto abre-se uma nova perspectiva para revestimentos metálicos e neste contexto se insere a recuperação por soldagem de partes erodidas de turbinas hidráulicas.The Plasma powder transferred arc welding process, which uses feed stock in the powder form, has similarities with Plasma wire transferred arc welding. This work describes a comparative study of the two processes using a Cobalt-based alloy commercially known as Stellite 6. This Co-based alloy is recognized for its superior cavitation erosion resistance. The aim of this work is to investigate the potential of PTA coatings for the protection and refurbishiment hydraulic turbine blades. Coatings were evaluated for the influence of Plasma gas flow rate on coating dilution, geometry, hardness and microstructure. Coatings processed with the atomized Stellite 6 powder feestock showed a superior surface quality, lower dilution

  4. Los padres como observadores de la calidad de vida de sus hijos implantados cocleares

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    Silvia Andrea BORKOSKI-BARREIRO

    2017-06-01

    Full Text Available Introducción y objetivo: El concepto de calidad de vida ha comenzado a utilizarse cada vez más en el campo de las evaluaciones en salud. Se ha empezado a investigar los efectos de la implantación a nivel del desarrollo social y emocional del niño. El objetivo es examinar los resultados de la salud relacionados con la calidad de vida en niños sordos implantados cocleares de entre 11 y 12 años de edad y sus padres. Método: Estudio observacional, descriptivo transversal en 24 niños prelocutivos implantados unilaterales o bilaterales sucesivos de 11 y 12 años de edad y sus padres. Utilizando el cuestionario de calidad de vida pediátrica PedsQL™ (Versión 4.0, español para España, para medir la salud relacionados con la calidad de vida, completado de forma independiente por niños y padres respectivamente. Resultados: Mediante la T-Student los resultados de niños y padres en las diferentes escalas evaluadas observamos que en las escalas de funcionamiento emocional y académica es donde se obtienen resultados estadísticamente significativos (p <0,05. Al comparar el resultado total del cuestionario con las diferentes escalas evaluadas, en todas ellas se obtienen resultados estadísticamente significativos (p <0,05. Discusión: Probado el éxito del implante coclear en las áreas del habla y del lenguaje, esto nos lleva actualmente a preguntas más allá de estas áreas; el rendimiento en el hogar, en la escuela y en diferentes contextos sociales. Pocos estudios exploran a través de entrevistas o cuestionarios las expectativas de los padres y la percepción de la calidad de vida de sus hijos usuarios de implantes coclear. Conclusiones: Los resultados del estudio muestran que los niños disfrutan de los beneficios del uso de su implante coclear. Ellos reportan beneficios en todas las áreas estudiadas (física, emocional, social y académica. Los padres son periodistas válidos sobre el estado de la calidad de vida global de sus hijos ya

  5. Plasma diagnostics by means of electric probes; Diagnostico del plasma por medio de sondas electricas

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    Colunga S, S

    1991-04-15

    In this work a summary of the classical theoretical models to interpret the characteristic curve of a Langmuir electric probe placed in a plasma without magnetic field and with the one is made. The methodology for the electron temperature calculation and the density of the plasma in both cases is given, starting from the characteristic curve of the probe, as well as the approaches for the correct application of this diagnostic method of the plasma. (Author)

  6. Synthesis of semiconductor polymers by inductive plasma; Sintesis de polimeros semiconductores por plasmas inductivos

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    Fernandez, G.; Cruz, G.; Olayo, M.G. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico); Morales, J. [UAM-I, 09340 Mexico D.F. (Mexico)

    2003-07-01

    When carrying out the synthesis of semiconductor polymers by plasma it is important to consider the electric arrangement of the discharge since this it influences in the distribution of the energy of the particles in the reactor. The main electric arrangements in those that are developed the brightness discharges of radio frequency are resistive, capacitive and inductive. In the Laboratory of Materials processing by plasma of the ININ its have been worked different synthesis of polymers with resistive arrangements with good results. In this work the results of the synthesis and characterization of poly aniline and chlorate polyethylene by inductive plasma are presented. (Author)

  7. Synthesis by plasma of halogenated poly anilines; Sintesis por plasma de polianilinas halogenadas

    Energy Technology Data Exchange (ETDEWEB)

    Enriquez, M.A.; Olayo, M.G.; Cruz, G.J. [Facultad de Quimica, UAEM, 50000 Toluca, Estado de Mexico (Mexico)

    2002-07-01

    In this work polymerization by plasma of aniline with iodine and chlorine bonded chemically to the aniline ring were realized. The results of the synthesis and characterizations are compared with those ones obtained starting from the poly aniline synthesis (P An) doped with iodine, where the dopant was aggregated in the moment of the polymerization. The objective is to study the dopant behavior in the synthesis by plasma in function of the properties of these polymers. (Author)

  8. Surface modification of polyethylene by plasma; Modificacion superficial de polietileno por plasma

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    Colin O, E

    2003-07-01

    The products made of polyethylene (PE) go from construction materials, electric insulating until packing material. The films for bags and pack occupy 83.6% of the distribution of the market of PE approximately. The enormous quantity of PE that is generated by its indiscriminate use brings as consequence a deterioration to the atmosphere, due to the long life that they present as waste. This work is a study on the modification of low density polyethylene films. In this type of thin materials, the changes in the surface meet with largely on the conformation of the rest of the material. To induce changes that modify the surface of PE, plasmas were used with reactive atmospheres of air, oxygen and nitrogen. The experimentation that was carries out went to introduce the PE to a cylindrical reactor where it was generated the plasma of air, oxygen and nitrogen to different times of exposure. After having carried out the exposure to the plasma, it was found that in the polyethylene it modifies their morphology, crystallinity, hydrophobicity, composition and electric conductivity. The analytical techniques that were used to characterize later to the polyethylene of being in contact with the plasma were: X-ray diffraction, Scanning Electron Microscopy, Infrared spectroscopy, Electric conductivity, Angle of contact and finally Thermal Gravimetric Analysis. The content of this work it is presented in five chapters: In the chapter 1 there are presented some general concepts of plasma and of the one polymer in study PE. In the chapter 2 it is made a general revision on modification of surfaces, as well as the properties that were modified in polymeric materials that were exposed to plasma in previous works. In the chapter 3 the experimental part and the conditions used are described in the modification of the PE. Also in this chapter a brief description it is made of the used characterization techniques. The results and discussion are presented in the chapter 4. These results

  9. Synthesis and characterization of poly iodine anilines by plasma; Sintesis y caracterizacion de poliyodoanilinas por plasma

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    Enriquez P, M A

    2003-07-01

    The polymers and organic materials present a numberless quantity of applications. However, it has not been but until recent times that it has been found that some of these materials can possess semiconductor properties. This has generated a great interest for the investigation in the area of semiconductor polymers. The poly aniline (Pan) it is one of the main semiconductor polymers because their electric properties change depending on the doping and of the state of oxidation to the one the molecules are subjected. The synthesis of this material has been carried out by means of chemical oxidation or electrochemistry. In this work a study is presented on the formation of poly aniline polymers with halogens chemically united to the aniline ring, poly(m-iodine aniline) (m-PAnI) and poly(m-chloroaniline) (m-PAnCI) for plasma. The plasma is generated by means of discharges of splendor with an r f amplifier to 13.5 MHz to drops pressures (10{sup -2} mbar). The synthesized polymers were obtained in form of thin film in the walls of the reactor and in the substrate introduced in the one. The electric properties of the polymers were evaluated in function of the time of reaction. Also, the conductivity of the polymers was compared synthesized in this work with reported data of synthesized poly aniline and doped with iodine for plasma. The highest values in conductivity are obtained in the poly aniline where the halogens are chemically connected to the ring that if it is doped with iodine. The atomic proportion in the surface of the polymers was analyzed by dispersive energy spectroscopy with which is deduced that the halogens come off of the molecules of the monomers or of the polymer in formation and that the atoms of iodine get lost more easily than those of chlorine. Other techniques that were used to characterize to the poly aniline were scanning electron microscopy, infrared spectroscopy, thermal gravimetric analysis and X-ray diffraction. The results are presented in

  10. Biocompatibility of poly allylamine synthesized by plasma; Biocompatibilidad de polialilamina sintetizada por plasma

    Energy Technology Data Exchange (ETDEWEB)

    Colin, E.; Enriquez, M.A.; Olayo, M.G.; Cruz, G.J. [Departamento de Fisica, ININ, Apdo. Postal 18-1027, D.F., CP. 11801, Mexico (Mexico); Morales, J.; Olayo, R. [Departamento de Fisica, UAM-I, A.P. 5534, Iztapalapa, D.F. (Mexico)]. e-mail: gog@nuclear.inin.mx

    2007-07-01

    A study of the electric and hydrophilic properties of poly allylamine (PAI) synthesized by plasma whose structure contains N-H, C-H, C-O and O-H bonds is presented, that promote the biocompatibility with the human body. To study the PAI hydrolytic affinity, solutions of salt concentration similar to those of the human body were used. The results indicate that the solutions modify the charge balance in the surfaces reducing the hydrophobicity in the poly allylamine whose contact angle oscillates among 10 and 16 degrees and the liquid-solid surface tension between 4 and 8 dina/cm. (Author)

  11. Isotopic separation by centrifugation. Rotating plasma; Separacion Isotopic por Centrifugacion Plasma Rotante

    Energy Technology Data Exchange (ETDEWEB)

    Perello, M; Vigon, M A

    1972-07-01

    The motion of a gas simultaneously submitted to an electric discharge and magnetic field has been studied in order to analyze the possibility of producing isotopes separation by rotation of a plasma. Some experimental results obtained under different discharge conditions are also given. Differences of pressure up to 15 mm oil between both electrodes has been attained. No definite conclusion on separation factors could be reached because of the low reproducibility of results, probably due to the short duration of the discharge with a new chamber designed to support stronger thermal shocks more reliable data can be expected. (Author) 16 refs.

  12. Los padres como observadores de la calidad de vida de sus hijos implantados cocleares

    OpenAIRE

    Borkoski-barreiro, Silvia Andrea; Falcón-gonzález, Juan Carlos; Torres-garcía de Celís, Margarita; Chicharro-soria, Isabel; Ramos-macías, Ángel

    2017-01-01

    Introducción y objetivo: El concepto de calidad de vida ha comenzado a utilizarse cada vez más en el campo de las evaluaciones en salud. Se ha empezado a investigar los efectos de la implantación a nivel del desarrollo social y emocional del niño. El objetivo es examinar los resultados de la salud relacionados con la calidad de vida en niños sordos implantados cocleares de entre 11 y 12 años de edad y sus padres. Método: Estudio observacional, descriptivo transversal en 24 niños prelocutivos ...

  13. Plasma source by microwaves: design description; Fuente de plasma por microondas: descripcion de diseno

    Energy Technology Data Exchange (ETDEWEB)

    Camps, E; Olea, O; Andrade, R; Anguiano, G

    1992-03-15

    The design of a device for the formation of a plasma with densities of the order of 10{sup 12} cm{sup -} {sup 3} and low temperatures (T{sub e} {approx} 40 eV) is described. For such purpose it was carried out in the device a microwave discharge (f{sub o} = 2.45 GHz) in a resonator of high Q factor, immersed in a static external magnetic field. The device worked in the regime {omega}{sub ce} {<=} {omega}{sub o}/2 ({omega}{sub ce}- cyclotron frequency of the electrons, ({omega}{sub o} = 2 {pi} f{sub o}) where is possible the excitement of non lineal phenomena of waves transformation. (Author)

  14. Synthesis by plasma of polymer-metal materials; Sintesis por plasma de materiales polimero-metal

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    Fernandez R, G

    2004-07-01

    The objective of this work is the design of an experimental set-up to synthesize polymer- metal composites by plasma with versatility in the conditions of synthesis. The main components are a vacuum system capable to reach up to 10{sup -2} mbar and valves and accessories to control the pressure in the system. In order to generate the electrical discharges and the plasma, an electrical circuit with an inductive connection at 13.56 MHz of frequency was constructed. The electric field partially ionizes the reactor atmosphere where the polymer-metal composites were synthesized. The reactor has two metallic electrodes, one in front of the other, where the particles electrically charged collide against the electrodes producing ablation on them. The polymer-metal composites were synthesized by means of an inductive connection at 13.56 MHz. Aniline, 3-chlorine-ethylene and electrodes of silver (Ag) and copper (Cu) were used in a cylindrical reactor coupled with an external coil to generate glow discharges. The average pressures were 6.15 X 10{sup -1} and 5.2 X 10{sup -1} mbar for the synthesis of Poly aniline (P An) and Poly chloroethylene (PE-CI), respectively. The synthesis was performed during 60 and 180 minutes for P An and PE-CI, respectively. The polymers were formed, as films, with an average thickness of 6.42 {mu}m for P An and, in the case of PE-CI, with an approximately growing rate of 14 {eta}m/W. The power in the syntheses was 30, 50, 70 and 90 W for P An and 50, 100, 120, 140 170, and 200 W for PE-CI. The characterization of the polymer-metal composites was done by energy dispersive spectroscopy to study the composition and the relation of the elements involved in the synthesis. The morphology of the films was studied by means of scanning electron microscopy. The infrared analysis (IR) was done to study the chemicals bonds and the structure of these polymers. Another important study in these materials was the behavior of the electrical conductivity ({sigma

  15. Study of photoconductor polymers synthesized by plasma; Estudio de polimeros fotoconductores sintetizados por plasma

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    Enriquez P, M.A

    2007-07-01

    In this work the photoconductivity in poly thiophene (PTh), poly pyrrole (PPy) and doped poly pyrrole with iodine (PPy/I) is studied, whose structures depend of the intensity of the electric field applied during the synthesis by plasma. The conjugated organic polymers possess double alternated bonds in its chemical structure that its allow the one movement of {pi} electrons through the polymeric chains. The plasma is produced by means of splendor discharges to 13.5 MHz, resistive coupling, at one pressure that oscillates in the interval from 2 to 3x10{sup -1} mbar, 180 min and powers of 10, 24, 40, {sup 60}, 80 and 100 W. Its were used heteroaromatic polymers like PTh and PPy/I, due to their potential applications in optoelectronics. The influence of the iodine is evaluated as dopant in PPy and it is compared with their similar one without doping in the light absorption/emission processes. The polymers synthesized by plasma can ramify or to intersect due to the energy applied during the synthesis. However, if the polymer intersects, the aromaticity can continue through the polymeric chains. The absorptions obtained by infrared spectroscopy, suggest that the polymer conserves the aromatic structure of the monomer fundamentally with substitutions that indicate inter crossing and partial fragmentation. The structure of most of the polymers spreads to be amorphous because they don't possess any classification. However, the PPy/I and PTh synthesized by this technique present crystalline segments whose intensity diminishes with the power of the discharge. In PTh, the average crystallinity diminishes from 19.8% to 9.9%, and in PPy/I of 15.9% to 13.3% in the interval of 10 to 100 W of power. In this work, however, its were crystalline arrangements in all the studied powers. The classification of the polymeric structure favors the formation of trajectories of transfer of electric loads among the chains, that which influences in the global electric conductivity of the

  16. Synthesis of biocompatible polymers by plasma; Sintesis de polimeros biocompatibles por plasma

    Energy Technology Data Exchange (ETDEWEB)

    Colin O, E

    2007-07-01

    In this work biocompatible polymers were synthesized by plasma based on pyrrole, ethyleneglycol and allylamine. These monomers are biologically important because they contain oxygen and nitrogen in their structure and they form bonding like; N-H, C-N, C-O and O-H that are also in the human system. The polymers were synthesized with splendor electric discharges to 13.5 MHz, among 10 and 100 W, resistive coupling, pressure of 10{sup -1} mbar and 180 minutes of reaction. The interaction of the biological systems with biomaterials depends in many cases of the properties that present the surfaces, because the rough and/or porous surfaces favor the adherence of cells. The results indicate that the ruggedness of the polymers can be controlled with the synthesis energy, since when modifying it flat and/or rough surfaces they are obtained. The compatibility of water with other solutions that it is a form of increasing the adhesion of cells with biopolymers. The affinity with water and solutions is evaluated calculating the contact angle of the polymers surface with drops of concentration solutions and similar composition to the extracellular liquid of the spinal marrow of the human body. The solutions that were proven were based on NaCl, NaCl-MgSO{sub 4}, and a mixture Krebs-Ringer that has chemical composition and similar concentration to that of the fluids of the spinal marrow. In the Poly pyrrole (PPy)/Polyethyleneglycol (PEG) copolymer, the biggest angles corresponded to the Krebs-Ringer solution, in the interval of 18 to 14 degrees and those lowest to the NaCl solution, of 14.5 at 11 degrees. The Poly allylamine had the more high values with water in the interval of 16.5 to 12.5 degrees and those lowest with the NaCl solution, of 13 at 9.5 degrees. On the other hand, in the derived polymers of pyrrole the more high values corresponded to the treatment with water, until 37, and those lowest to the NaCl-MgSO{sub 4} solution, up to 10. The solutions where participated Na

  17. EFECTO DEL RALEO SOBRE EL CRECIMIENTO Y LA DENSIDAD DE LA MADERA DE Pinus taeda IMPLANTADO EN MISIONES, ARGENTINA

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    Rodolfo Martiarena

    2014-09-01

    Full Text Available http://dx.doi.org/10.5902/1980509815746El mayor incremento en crecimiento de la plantación puede causar variación en las propiedades físicas de la madera, pudiendo disminuir la calidad de la misma para la industria. El objetivo del presente trabajo es evaluar el efecto de los tratamientos de raleo sobre el crecimiento y densidad de la madera de Pinus taeda implantado en Misiones, Argentina (25º 59’S - 54º24’O. La plantación se estableció en 1985 con densidad inicial de 1644 pl.ha-1y se manejó con tres intensidades de raleo (0, 33 y 66 % del área basal del testigo sin ralear, bajo un diseño de bloques completos al azar (3 bloques. A los 20 años se efectuó tala rasa, cuyas densidades eran 711 (0 %, 364 (33 % y 122 (66 % plantas por hectárea, momento en el cual se seleccionaron 45 árboles para determinar la densidad básica de la madera. La misma se determinó a través de la realización de 2.700 probetas. El crecimiento de la plantación fue afectado por la intensidad de raleo, registrando diámetros promedio de 28,7, 34,8 y 45,9 cm, respectivamente, en los tratamientos 0, 33 y 66 % de raleo. El volumen de la plantación, al momento del apeo, fue superior en el tratamiento sin raleo, no obstante el tratamiento 66 % de raleo generó mayor cantidad de madera de grandes dimensiones. La densidad básica como promedio simple y ponderado por volumen no presentó diferencias significativas entre tratamientos. Los valores de densidad ponderada fueron de 0,406, 0,418 y 0,420 g.cm-3 para los tratamientos 0, 33 y 66 % de raleo, respectivamente, mientras que el análisis de correlación entre diámetro y densidad no fue significativo. El estudio mostró que la intensidad de raleo puede ser manejada para maximizar la producción, manteniendo idéntica la calidad de la madera para la industria.

  18. EFECTO DEL RALEO SOBRE EL CRECIMIENTO Y LA DENSIDAD DE LA MADERA DE Pinus taeda IMPLANTADO EN MISIONES, ARGENTINA

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    Rodolfo Martiarena

    2014-01-01

    Full Text Available El mayor incremento en crecimiento de la plantación puede causar variación en las propiedades físicas de la madera, pudiendo disminuir la calidad de la misma para la industria. El objetivo del presente trabajo es evaluar el efecto de los tratamientos de raleo sobre el crecimiento y densidad de la madera de Pinus taeda implantado en Misiones, Argentina (25º 59’S - 54º24’O. La plantación se estableció en 1985 con densidad inicial de 1644 pl.ha -1 y se manejó con tres intensidades de raleo (0, 33 y 66 % del área basal del testigo sin ralear, bajo un diseño de bloques completos al azar (3 bloques. A los 20 años se efectuó tala rasa, cuyas densidades eran 711 (0 %, 364 (33 % y 122 (66 % plantas por hectárea, momento en el cual se seleccionaron 45 árboles para determinar la densidad básica de la madera. La misma se determinó a través de la realización de 2.700 probetas. El crecimiento de la plantación fue afectado por la intensidad de raleo, registrando diámetros promedio de 28,7, 34,8 y 45,9 cm, respectivamente, en los tratamientos 0, 33 y 66 % de raleo. El volumen de la plantación, al momento del apeo, fue superior en el tratamiento sin raleo, no obstante el tratamiento 66 % de raleo generó mayor cantidad de madera de grandes dimensiones. La densidad básica como promedio simple y ponderado por volumen no presentó diferencias significativas entre tratamientos. Los valores de densidad ponderada fueron de 0,406, 0,418 y 0,420 g.cm -3 para los tratamientos 0, 33 y 66 % de raleo, respectivamente, mientras que el análisis de correlación entre diámetro y densidad no fue significativo. El estudio mostró que la intensidad de raleo puede ser manejada para maximizar la producción, manteniendo idéntica la calidad de la madera para la industria.

  19. Validação de procedimentos operacionais padrão no cuidado de enfermagem de pacientes com cateter totalmente implantado

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    Rita Paiva Pereira Honório

    2011-10-01

    Full Text Available Os protocolos de assistência são recursos tecnológicos importantes na prática de saúde e devem ser validados, para adquirirem credibilidade científica na prática profissional. O objetivo desta pesquisa foi validar os itens de proposta de procedimentos operacionais padrão (POPs quanto à punção, heparinização e curativo do cateter totalmente implantado, por meio da análise de conceito proposta por Hoskins. O estudo se deu em duas etapas. Na primeira, elaborou-se um formulário para validação dos POPs. Na segunda, avaliou-se o conteúdo dos POPs por peritos. As sugestões versaram sobre reformulação da redação; acréscimo de ações, tornando-o mais claro e abrangente; a ordem dos passos dos procedimentos; e o material para a adequação do instrumento. Constatou-se a necessidade de outros estudos que direcionem os profissionais, principalmente, quanto à heparinização dos cateteres e à troca do primeiro curativo após punção, no sentido de uniformizar condutas embasadas em evidências científicas seguras.

  20. Simulación de la formación de plasma en el mecanizado por electroerosión

    OpenAIRE

    Villagomez Galindo, Miguel; González Rojas, Hernan Alberto

    2017-01-01

    El proceso de mecanizado por electroerosión es una técnica de manufactura no convencional caracterizada por descargas eléctricas controladas que liberan tal cantidad de energía que es capaz de transformar en plasma el dieléctrico circundante al material conductor a mecanizar, con la consecuente sublimación del mismo, lo que provoca la remoción de material. En este trabajo se presenta la simulación de la formación de plasma debido a una sucesión de descargas eléctricas durante el p...

  1. Generación eléctrica por gasificación por arco de plasma de residuos urbanos

    OpenAIRE

    Sosa, María Isabel; Bussolini, Ignacio

    2015-01-01

    La presente temática surgió de la realización del trabajo final de I. Bussolini, presentado en la Facultad de Ingeniería de la Universidad Nacional de La Plata para optar por el grado de Ingeniero Industrial. Interesado en la problemática de la generación energética en conjunción con protección del medio ambiente analizó la factibilidad de la instalación de una planta generadora de electricidad conectada al Mercado Eléctrico Mayorista MEM argentino, utilizando la tecnología de gasificación de...

  2. Estudio por emisión acústica del comportamiento a flexión de recubrimientos WC-Co obtenidos por plasma atmosférico

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    Segovia, F.

    2007-12-01

    Full Text Available Plasma sprayed cermet coatings WC-Co are used in a wide range of industrial applications, mainly due to their wear resistance even in corrosive environments. The objective of this work is to analyze mechanical response of hard metal coatings by means of three- and four-points bend tests applying acoustic emission technique to determine failure critical strength. It has been observed the effect of supported charge level in structural damage by means of optical microscopy and scanning electron microscopy. Acoustic emission has allowed us to relate damage level to stresses level and then to understand coatings failure mechanism.

    Los recubrimientos de cermet WC-Co proyectados por plasma se utilizan en un amplio rango de aplicaciones industriales, principalmente por su resistencia al desgaste, incluso en medio corrosivo. El objetivo de este trabajo es analizar la respuesta mecánica de los recubrimientos de metal duro mediante ensayos de flexión a 3 y 4 puntos aplicando el método de emisión acústica para determinar las tensiones críticas de fallo. Se ha observado el efecto del nivel de carga soportado en el dañado estructural mediante microscopia óptica y electrónica de barrido. La emisión acústica ha permitido relacionar el grado de dañado con el nivel de tensiones y, así, entender el mecanismo de fallo de los recubrimientos.

  3. Polymerization by plasma of trichloroethylene by means of resistive and inductive coupling; Polimerizacion por plasmas de tricloroetileno por medio de acoplamiento resistivo e inductivo

    Energy Technology Data Exchange (ETDEWEB)

    Vasquez, M.; Cruz, G.; Olayo, M.G. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico); Timoshina, T. [IPN, ESIQIE, 07738 Mexico D.F. (Mexico); Morales, J.; Olayo, R. [UAM-I, 09340 Mexico D.F. (Mexico)

    2004-07-01

    It was carried out the polymerization for plasma of the trichloroethylene by means of two types of coupling, resistive and inductive with the objective of studying the structure, morphology and the electric properties of the polymers obtained under these conditions. The structure and morphology of the polymers were studied by means of EDS and FT-IR spectroscopies. (Author)

  4. DESGASTE POR ABRASIÓN DEL ACERO API 5L X65 REVESTIDO CON NIOBIO POR ASPERSIÓN TÉRMICA A PLASMA Y CON INCONEL 625 POR SOLDADURA

    Directory of Open Access Journals (Sweden)

    JOSE MATOS

    2012-01-01

    Full Text Available El objetivo de este trabajo fue evaluar y caracterizar el comportamiento mecánico en desgaste del acero API 5L X65, revestido con niobio en comparación al desempeño del revestimiento de la aleación de inconel 625 empleados en la industria de petróleo y gas. El revestimiento de niobio fue obtenido por el proceso de aspersión térmica a plasma de arco no transferido y el revestimiento inconel 625 por soldadura con electrodo revestido. La resistencia al desgaste por abrasión fue evaluada según la norma Petrobras N-2568, en un tribómetro CTER, la rugosidad y el volumen de material desgastado se determinó a través de perfilometría y la dureza de los revestimientos por microscopia Vickers. Los revestimientos obtenidos fueron caracterizados respecto a su morfología por microscopia electrónica de barrido (MEB y microscopía óptica (MO. La mayor dureza del revestimiento con niobio obtenido puede haber contribuido a reducir la tasa de desgaste en comparación con el revestimiento de inconel 625.

  5. Caracterização por FT-IR da superfície de borracha EPDM tratada via plasma por micro-ondas

    Directory of Open Access Journals (Sweden)

    Renata P. dos Santos

    2012-01-01

    Full Text Available A superfície de uma borracha de etileno-propileno-dieno (EPDM vulcanizada foi modificada via plasma por microondas, com gases Ar, Ar/O2, N2/O2 e N2/H2, tendo como objetivo melhorar as propriedades adesivas da superfície. A técnica FT-IR/UATR foi escolhida para caracterizar as superfícies após tratamento, pois apresentou menor interferência dos ingredientes da formulação da EPDM, dentre as técnicas analisadas (ATR/KRS-5 e Ge. Grupos oxigenados foram inseridos na superfície da amostra tratada, mesmo quando não foi utilizado o oxigênio, pois estes grupos foram formados quando a superfície ativada foi exposta à atmosfera. Já em tratamentos contendo N2, grupos oxigenados e possíveis grupos nitrogenados foram identificados por FT-IR. Redução nos valores do ângulo de contato, aumento no trabalho de adesão e aumento no ensaio de resistência ao descascamento (EPDM × Poliuretano foram observados após tratamento com Ar e N2/H2, resultando em melhora nas propriedades adesivas da superfície tratada.

  6. Plasma rico em plaquetas (PRP) por meio de centrífuga de bancada

    OpenAIRE

    Calixto, Carlos Alberto [UNIFESP

    2011-01-01

    BACKGROUND: Platelet-rich plasma is an autologous concentration of autologous platelets in a small volume of plasma, obtained by centrifugation of the whole blood, and have been considered to be a rich source of growth factors. OBJECTIVE: Establish a method to prepare a platelet-rich plasma by centrifugation. METHODS: In this study 40 ml from the whole blood was obtained from eight volunteers, and seventy-two tests were performed in three groups (control, one spin, and two spins), changing th...

  7. Degradation of polyethylene induced by plasma in oxidizing atmospheres; Degradacion de polietileno inducido por plasma en atmosferas oxidantes

    Energy Technology Data Exchange (ETDEWEB)

    Colin, E.; Olayo, M.G.; Cruz, G.J. [Facultad de Quimica, UAEM, Av. Tollocan y Colon, 50000 Toluca (Mexico)

    2002-07-01

    The garbage of polyethylene is not easily degradable in normal environmental conditions . The indiscriminate use of this polymer and the enormous quantity of garbage which is generated carries a damage to the environment due to its long life as waste. The objective of this work is to study the conditions in which can be carried out the degradation of polyethylene. A form of accelerating the degradation is exposing it to plasma with reactive atmospheres. In this work a study of surface modification of polyethylene by plasmas with discharges of direct current of oxygen and nitrogen is presented. (Author)

  8. Morphological study of synthesized chlorinated polyethylene by inductive plasma; Estudio morfologico de polietileno clorado sintetizado por plasmas inductivos

    Energy Technology Data Exchange (ETDEWEB)

    Olayo, M.G.; Cruz, G.; Carapia, L.; Fernandez, G. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico); Morales, J. [UAM-I, A.P. 55-534, Mexico D.F. (Mexico)

    2004-07-01

    In this work a morphological study on the synthesis of Chlorinated polyethylene for plasma starting from Trichloroethylene in a polymerization process and ablation simultaneous of metals, where silver atoms and copper are inserted directly during the growth of the polymer from the gas phase to the one solid is presented. (Author)

  9. Synthesis of allyl amine on glass by continuous plasma; Sintesis de alilamina sobre vidrio por plasma continuo

    Energy Technology Data Exchange (ETDEWEB)

    Morales, J.; Olayo, R. [UAM-I, 09340 Mexico D.F. (Mexico); Vasquez, M.; OLayo, M.G.; Cruz, G. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    2003-07-01

    In this work the synthesis by plasma of thin films of polyallyl amine under continuous plasma conditions for possible use in biomaterials is presented. It is shown that the thickness of the film depends so much of the time of synthesis like of the used power. The polymers were analyzed by X-ray photoelectron spectroscopy (XPS) and angle of contact before and after of being immersed in distilled water by 10 days. The allylamine shows lost of nitrogen and an increase in the content of oxygen with the immersion time due to the interaction among the water and the polymer. The angle of contact shows an increase of approximately 10 degrees, what indicates a change in the surface energy of the polymer. (Author)

  10. 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)

  11. Structure and photoconductivity in synthesized poly thiophene by plasma; Estructura y fotoconductividad en politiofeno sintetizado por plasma

    Energy Technology Data Exchange (ETDEWEB)

    Enriquez, M.A.; Colin, E.; Cruz, G.J.; Olayo, M.G.; Ordonez, E. [ININ, A.P. 18-1027, Mexico, D.F. (Mexico); Morales, J.; Olayo, R. [UAM-I, A.P. 55-534 Mexico D.F. (Mexico); Romero, M. [UAM-A, DEP, 02200 Mexico D.F. (Mexico)]. e-mail: angelenrimx@hotmail.com

    2006-07-01

    his work the electric answer of poly thiophene is studied (PTh) to pulses of light to evaluate its luminescence potential. The synthesis of the polymers is made by plasma with different energy to study its effects on the structure of the material. The electric conductivity was calculated by means of the resistance of the polymers in a parallel arrangement of badges between 10 to 250 V, stimulated with ultraviolet light (250 nm) to promote the transfer of electric loads to different temperatures. The results indicate that the aromatic structure of the PTh depends on the power applied during the synthesis. (Author)

  12. Synthesis by plasma and characterization of compounds derived from polyacetylene; Sintesis por plasma y caracterizacion de compuestos derivados del poliacetileno

    Energy Technology Data Exchange (ETDEWEB)

    Vasquez O, M

    2004-07-01

    This work presents a study on, the synthesis by plasma and the characterization of an aliphatic conjugated polymer, polyacetylene-chlorinated (Pac), and two aromatic polymers, Poly pyrrole (P Py-Cl) and Poly thiophene (Pth-Cl) synthesized with chlorine and the electrical conductivity. The last two polymers were synthesized to compare the chlorine-polymer interaction in aliphatic and aromatic polymers synthesized by plasma and their repercussion on the electrical transport of charges in the material. The structure and morphology of the polymers were studied using scanning electron microscopy (Sem), energy dispersive spectroscopy (EDS), infrared spectroscopy (Ft-IR), conductivity analysis and X-Ray photon spectroscopy (XPS). The results showed that Pac is soluble in acetone and other organic solvents, which indicates a low proportion of crosslinking in the polymers. This point is important because the crosslinking reduces the electrical conductivity in the material. The Pac conductivity is in the range of 1 x 10{sup -12} to 6 x 10{sup -4} S/cm in the internal of 35- 90% of relative humidity. A possible mechanism for the transport of electrical charges in Pac is by means of the double and simple conjugated bonds in the polymers. Pth-Cl and P Py-Cl present electric conductivity in the interval of 9 x 10{sup -5} to 1 x 10{sup -2} S/cm and show a great dependence on the relative humidity. The chlorine addition in these polymers was through simultaneous polymerization with chloroform. This last compound can decompose if the energy of the plasma is relatively high, and the fragments can link to the polymer in a hybrid process of copolymerization. An important point of this work is that the polymer is soluble, a difference of the obtained via plasma as the poli aniline, P Py-CI and Pth-Cl both studied in this work. If took in account that the Pac is single the monomer and that P Py-Cl and Pth-CI is affected by the chlorine that modifies the conductivity of the material

  13. EVALUACIÓN HISTOLÓGICA DE BIOCOMPATIBILIDAD Y BIOCONDUCCIÓN DEL COMPUESTO HIDROXIAPATITA - LIGNINA IMPLANTADO EN TIBIA DE CONEJOS

    Directory of Open Access Journals (Sweden)

    Marlene Vargas V

    2009-04-01

    Full Text Available Objetivo. Evaluar histologicamente la biocompatibilidad y propiedad óseoconductora del compuesto de hidroxiapatita - lignina implantado en tibias de conejos. Material y métodos. Se utilizaron 20 conejos de raza nueva Zelanda, en cada uno, la tibia izquierda fue tratada con el compuesto y la tibia derecha no fue tratada y sirvió como control. Con la ayuda de taladro manual y una broca se realizó un defecto óseo de aproximadamente 4 mm de diámetro en la superficie lateral proximal tibial, hasta alcanzar el canal medular. Dos comprimidos del compuesto (400 mg, se utilizaron para rellenar el defecto. El mismo procedimiento quirúrgico se realizó en el grupo control, sin la utilización del compuesto. Las evaluaciones histológicas se realizaron a los 8, 30, 60, 90 y 120 días postcirugía, para lo que fue necesaria la eutanasia de 4 animales por fecha de evaluación. Resultados. En las evaluaciones de 30, 60, 90 y 120 días se observó una formación ósea más acelerada y extensa en el grupo tratado al compararse las lecturas histológicas con el grupo control. Conclusiones. El compuesto hidroxiapatita-lignina permitió el crecimiento de tejido óseo desde los bordes hasta el centro del defecto a un ritmo de crecimiento mayor, con formación de hueso mas organizado que en el grupo control. Además se observó su integración al tejido óseo; lo que sugiere su biocompatibilidad y propiedad óseoconductora, hecho que permite recomendarlo como substituto.

  14. Tratamento da superfície de cateteres de poliamida 11 por plasma de oxigênio

    Directory of Open Access Journals (Sweden)

    Gean V. Salmoria

    2013-01-01

    Full Text Available A poliamida 11, assim como grande parte dos polímeros empregados na construção de dispositivos minimamente invasivos de uso médico, não apresenta significativa interação com líquidos polares, o que limita seu uso em algumas aplicações, uma vez que a maioria dos tecidos biológicos internos apresenta caráter hidrofílico (alta afinidade por água. No presente trabalho, investigou-se a influência do processo de tratamento por plasma de oxigênio da superfície da poliamida 11 sobre a composição, rugosidade e a hidrofilicidade. Através do tratamento, as características do material foram alteradas de forma a favorecer a adesão de uma camada polimérica hidrofílica sobre sua superfície, aumentando a hidrofilicidade e, consequentemente, a biocompatibilidade do dispositivo polimérico. Cateteres de poliamida 11 foram submetidos a diferentes tempos de exposição ao plasma, gerado sob uma atmosfera de oxigênio com pressão, temperatura e voltagem constante. Para isso, foram realizadas análises de espectroscopia de infravermelho, microscopia eletrônica de varredura e medida do ângulo de molhamento por água na superfície do polímero. As amostras tratadas e não tratadas (controle foram caracterizadas e constatou-se um aumento na rugosidade e no ângulo de contato, indicando uma possível melhora da aderência da camada polimérica hidrofílica a ser depositada.

  15. Redução da hidrofilicidade de filmes biodegradáveis à base de amido por meio de polimerização por plasma Reduction of hydrophilicity of biodegradable starch-based films by plasma polymerization

    Directory of Open Access Journals (Sweden)

    Rossana M. S. M. Thiré

    2004-03-01

    Full Text Available Devido ao baixo custo de produção e excelente biodegradabilidade, o amido constitui-se em matéria-prima promissora para a produção de plásticos biodegradáveis. No entanto, a grande hidrofilicidade dos filmes à base de amido representa uma séria limitação tecnológica à sua comercialização, uma vez que as propriedades dos filmes são afetadas pela variação da umidade relativa do ar durante a sua estocagem ou o seu uso. Neste trabalho, filmes de amido termoplástico foram recobertos com uma fina camada protetora polimérica gerada por intermédio da tecnologia de plasma frio. 1-Buteno e 1,3-butadieno foram utilizados como monômeros para a polimerização por plasma. Os filmes recobertos apresentaram uma redução de até 80% na absorção de água e aumento do ângulo de contato em relação à água. Estes resultados indicaram uma redução significativa na natureza hidrofílica do material à base de amido após o recobrimento.Due to low cost and excellent biodegradability, the use of starch as a raw material for bioplastic production is growing in interest. However, the properties of starch-based materials are affected by relative humidity during their use and storage due to their hydrophilic character. In this work, thermoplastic cornstarch films were coated by cold plasma technology with a protective thin layer in order to reduce water sensitivity. 1-Butene and 1,3-butadiene were used as monomers for plasma polymerization. Coated films presented a reduction of water absorption up to 80% an increase in contact angle related to water. These results indicated that the coating process reduced significantly the hydrophilic nature of the starch-based materials.

  16. Estudos de esterilização por plasma a pressão atmosférica

    OpenAIRE

    Souza, João Henrique Campos de

    2013-01-01

    Apesar da variedade de tecnologias disponíveis aos serviços de saúde paia o processamento dos produtos para a saúde, as especificidades de cada instrumental são determinantes na escolha do método mais indicado. Atualmente, o desafio da área tecnológica é desenvolver métodos eficazes para o processamento de materiais que não podem ser submetidos a grandes estresses físicos, como temperatura e pressão. A esterilização por plasma é uma tecnologia que chama muito a atenção pela rapidez, segurança...

  17. Processamento de Ligas de Níquel com Técnica de Manufatura Aditiva Utilizando Plasma por Arco Transferido

    Directory of Open Access Journals (Sweden)

    Eduardo André Alberti

    2015-06-01

    Full Text Available ResumoA manufatura aditiva é um processo utilizado para a construção e reparos de peças que possuem geometria complexa ou que necessitem de gradiente de propriedades. Nessa técnica múltiplas camadas são depositadas para a construção da geometria do componente. O sucesso desse procedimento depende de fatores como a técnica de deposição, parâmetros, liga a ser depositada e condições da deposição, como temperatura e atmosfera protetora. Neste estudo, o potencial da técnica de Plasma por arco transferido para manufatura aditiva foi avaliado produzindo “paredes finas”, construídas a partir da sobreposição de cordões. Foram utilizadas duas ligas a base de níquel, uma endurecida por precipitação e outra endurecida por solução sólida. Durante os trabalhos, foram selecionados os parâmetros de processamentos, incluindo a avaliação do efeito do pré-aquecimento a 300°C. Resultados mostraram que a composição química da liga influencia a geometria da parede construída assim como a utilização de pré-aquecimento. Estruturas de solidificação exibindo dendritas refinadas com crescimento epitaxial entre camadas são identificadas. Entretanto, as características da liga determinam o perfil de dureza ao longo da seção transversal, sendo a liga endurecida por precipitação influenciada pelos ciclos térmicos de deposição e a liga endurecida por solução sólida pela diluição com o substrato. Em qualquer dos casos é recomendado a aplicação de tratamento térmico pós-soldagem para uniformização das propriedades.

  18. Estudo histológico do tecido conjuntivo areolar perifascial implantado em pregas vocais de coelhos

    OpenAIRE

    Adriana Hachiya

    2009-01-01

    Apesar do grande avanço da laringologia nas últimas décadas, o tratamento da rigidez da prega vocal continua sendo um desafio. A rigidez da prega vocal pode estar associada a alterações estruturais mínimas como no sulco vocal profundo ou decorrente da fibrose cicatricial como nos casos de cicatriz pós-operatória. Em ambos os casos, há perda dos elementos da matriz extracelular da camada superficial da lâmina própria (Espaço de Reinke) que se encontra substituída por tecido cicatricial. O obje...

  19. Caracterização por FT-IR da superfície de borracha EPDM tratada via plasma por micro-ondas FT-IR characterization of EPDM rubber surface treated by microwave plasma

    Directory of Open Access Journals (Sweden)

    Renata P. dos Santos

    2012-01-01

    Full Text Available A superfície de uma borracha de etileno-propileno-dieno (EPDM vulcanizada foi modificada via plasma por microondas, com gases Ar, Ar/O2, N2/O2 e N2/H2, tendo como objetivo melhorar as propriedades adesivas da superfície. A técnica FT-IR/UATR foi escolhida para caracterizar as superfícies após tratamento, pois apresentou menor interferência dos ingredientes da formulação da EPDM, dentre as técnicas analisadas (ATR/KRS-5 e Ge. Grupos oxigenados foram inseridos na superfície da amostra tratada, mesmo quando não foi utilizado o oxigênio, pois estes grupos foram formados quando a superfície ativada foi exposta à atmosfera. Já em tratamentos contendo N2, grupos oxigenados e possíveis grupos nitrogenados foram identificados por FT-IR. Redução nos valores do ângulo de contato, aumento no trabalho de adesão e aumento no ensaio de resistência ao descascamento (EPDM × Poliuretano foram observados após tratamento com Ar e N2/H2, resultando em melhora nas propriedades adesivas da superfície tratada.The surface of a vulcanized ethylene propylene diene monomer (EPDM rubber was modified by microwave plasma in Ar, Ar/O2, N2/O2 and N2/H2 in order to improve the adhesion properties. Surface modification was characterized by FT-IR/UATR, because this technique showed smaller interference of ingredients of EPDM formulation in comparison with other techniques used (ATR KRS-5 and Ge. Oxygenated groups were introduced in the EPDM surface after treatment, even in treatments without oxygen. Theses groups were formed when the activated surface was exposed to the atmosphere. In treatments with nitrogen, oxygenated and possible nitrogenated groups were identified by FT-IR. Reduction in the contact angle, increase in the work of adhesion and increase in the peel strength (EPDM × Polyurethane were observed after treatment with Ar and N2/H2, resulting in improved adhesion properties of the modified surface.

  20. Determination of selenium and zinc in rat plasma by instrumental neutron activation analysis; Determinacion de selenio y zinc en plasma mediante analisis por activacion neutronica instrumental

    Energy Technology Data Exchange (ETDEWEB)

    Munoz A, Luis

    1998-12-31

    To evaluate the effects on the thyroid function when simple or multiple zinc, selenium and iodine deficiency are induced, research was carried out in laboratory animals. For simultaneously determining the Zn and Se concentration in rat plasma, an instrumental neutron activation analysis technique was applied. A clean laboratory, was used for the preparation of samples. High purity materials were used for sample collection and storage. Irradiation, decay and counting parameters were optimized to obtain the best sensitivity, accuracy and precision analysis. The Zn and Se concentrations were determined from the peak area of gamma-rays of 1115 and 265 KeV respectively. The analytical methodology used was validated with standard reference materials. The procedure used for the analysis, including the phases of collection, treatment of the samples and analytical determination was considered suitable for the study of trace elements in biological samples, especially plasma. (author). Dissertation to obtain the title of Bachelor in Chemistry; 46 refs., 12 figs., 17 tabs. [Espanol] Con el proposito de evaluar los efectos que se producen sobre la funcion tiroidea cuando se induce un deficiencia simple o multiple de zinc, selenio y yodo, se llevo a cabo una investigacion en animales de experimentacion. Se aplico la tecnica de analises por activacion neutronica instrumental para la determinacion de Se y Zn en plasma de ratas. Se utilizo un laboratorio limpio clase 100 para la preparacion de las muestras y se emplearon materiales de alta pureza para su recoleccion y almacenamiento. Se optimizaron los parametros de irradiacion, decaimiento y conteo de las muestras con el proposito de alcanzar la mejor sensibilidad, exactitud y precision analitica. Las concentracion de Se y Zn fueron determinadas evaluando las areas de los fotopicos de 265 y 1115 KeV respectivamente. El metodo analitico fue validado utilizando materiales de referencia. El procedimiento utilizado para el analisis

  1. EVALUACIÓN EXPERIMENTAL DE LA RESISTENCIA A LA CORROSIÓN DE UN ACERO AISI-SAE 4140 IMPLANTADO CON IONES DE NITRÓGENO

    OpenAIRE

    PEÑA, DARIO; FONTALVO, PAOLA; ESTUPIÑAN, HUGO; NIÑO, DANNIER; VESGA, WILSON

    2009-01-01

    Se estudió la resistencia a la corrosión de un acero AISI-SAE 4140 implantado con iones de Nitrógeno mediante la técnica 3DII (Implantación Iónica Tridimensional). Se evaluaron diferentes rugosidades de las muestras implantadas mediante técnicas electroquímicas de Rp, EIS y Tafel en una salmuera al 3% de NaCl, donde se obtuvo la mayor resistencia a la corrosión para el material implantado con menor rugosidad. Se produjo la formación de una posible capa protectora estable con la inmersión de l...

  2. EVALUACIÓN EXPERIMENTAL DE LA RESISTENCIA A LA CORROSIÓN DE UN ACERO AISI-SAE 4140 IMPLANTADO CON IONES DE NITRÓGENO

    Directory of Open Access Journals (Sweden)

    DARIO PEÑA

    2009-01-01

    Full Text Available Se estudió la resistencia a la corrosión de un acero AISI-SAE 4140 implantado con iones de Nitrógeno mediante la técnica 3DII (Implantación Iónica Tridimensional. Se evaluaron diferentes rugosidades de las muestras implantadas mediante técnicas electroquímicas de Rp, EIS y Tafel en una salmuera al 3% de NaCl, donde se obtuvo la mayor resistencia a la corrosión para el material implantado con menor rugosidad. Se produjo la formación de una posible capa protectora estable con la inmersión de las muestras en el electrolito de trabajo para tiempos superiores a 240 horas.

  3. Comportamiento a desgaste de recubrimientos de WC proyectados por plasma a partir de polvos micro y nanoestructurados

    Directory of Open Access Journals (Sweden)

    Salvador, M. D.

    2008-06-01

    Full Text Available The aim of the present work is the study of wear behaviour of different WC coatings deposited on stainless steel substrate by means of atmospheric plasma spraying (APS. Two types of WC commercial powders, with different metal binder (12% Cobalt and 10% Nickel have been deposited in order to analyse the influence of the metal matrix and thickness of the coating in tribological properties.The microstructure of the depositions was characterized using scanning electron microscopy (SEM and X-ray diffraction analysis (XRD. On the other hand, tribology characterization of the coatings was made by pin-on-disk wear tests against alumina (2400HV and silicon nitride (1600HV ceramic balls, without lubrication. Wear rates and friction coefficient evolution have been calculated. Finally, wear tracks and wear debris have been analysed with the help of SEM.The results of each pair of tested materials show different mechanisms of wear related to the nature of the ball that has been used, obtaining higher wear rates with silicone nitride ball..In a second phase of the study, in order to examine the influence of the initial particle size on the wear properties of the coatings, cobalt based coatings have been analysed with different initial particle size (micrometric and nanometric particles.Results show that nanostructured coatings have higher wear resistance than microstrutured ones for high loads. However for low loads, behaviour is similar in spite of the microstructural differences appreciated.

    El objetivo de este trabajo es estudiar el comportamiento a desgaste de distintos recubrimientos de WC sobre acero inoxidable mediante proyección por plasma atmosférico. Se proyectan dos tipos de polvos comerciales con base cobalto (12 % y níquel (10 %, con el objeto de analizar la influencia de la matriz e incluso del espesor del recubrimiento. Los recubrimientos obtenidos se caracterizan microestructuralmente por microscopía electrónica de barrido y

  4. Revestimentos obtidos por oxidação da liga AA3104-H19 por plasma eletrolítico (PEO)

    OpenAIRE

    Luciene Vanessa Maia da Rocha

    2013-01-01

    Resumo: O alumínio (Al) é o terceiro elemento metálico mais abundante na Terra. É um metal leve e é notável pela sua capacidade de resistir à corrosão. Estas características tornam o alumínio amplamente utilizado para embalagens de bebida, sendo importante na proteção e na conservação do produto. Entretanto, produtos muito ácidos, como por exemplo, os refrigerantes, os chás e os sucos cítricos, podem levar à corrosão de embalagens metálicas, ocasionando a degradação do material. Atualmente, s...

  5. Recubrimientos protectores para componentes de turbinas de aviación y de generación de energía depositados por proyección por plasma

    Directory of Open Access Journals (Sweden)

    Agüero Bruna, A.

    2000-08-01

    Full Text Available Coatings produced by aluminium diffusion, called aluminide are employed to increase the oxidation and corrosion resistance, increasing the life of Ni and Co base superalloys components at temperatures comprised between 900 and 1050ºC. Consequently these coatings are frequently employed in aeronautic and power generation turbines as well as in the chemical industry. Aluminides are industrially produced by pack cementation or CVD and recently it has been demonstrated that its resistance significantly increases when Cr is added (chrome-aluminides. During this work, a feasibility study has been carried out in order to determine if plasma spray can be employed for depositing this type of coatings on turbine blades. Therefore, aluminium and aluminium/chromium layers were deposited on Ni base IN100 superalloy specimens that were subsequently subjected to a diffusion heat treatment under Ar flow. Characterisation and analysis of the coatings were carried out by metallography , SEM and EDS. Cyclic oxidation tests were carried out at 1050º C while molten sulphate hot corrosion was performed at 900º C. The results of this preliminary study are promising and indicate that plasma spray can be developed as an industrial process for production of aluminide and chrome-aluminide coatings.

    Los recubrimientos producidos por difusión de aluminio, llamados aluminuros, se emplean para aumentar la resistencia a la oxidación y a la corrosión, incrementando la vida de componentes fabricados con superaleaciones de níquel y cobalto a temperaturas comprendidas entre 900 y 1050º C. Por ello se emplean muy frecuentemente en turbinas aeronaúticas y de producción de energía y en la industria química. Los aluminuros se obtienen industrialmente mediante cementación o CVD y recientemente se ha demostrado que su resistencia aumenta significativamente cuando se añade cromo (cromoaluminuros. Durante el presente trabajo, se ha realizado un estudio de viabilidad

  6. Plasma nitriding and simultaneous tempering of VF 800AT tool steel; Nitretacao por plasma com revenimento simultaneo do aco ferramenta VF 800AT

    Energy Technology Data Exchange (ETDEWEB)

    Prass, Andre Ricardo; Fontana, Luis Cesar; Recco, Abel Andre Candido, E-mail: prass.andrericardo@gmail.com, E-mail: luis.fontana@udesc.br, E-mail: abel.recco@udesc.br [Universidade do Estado de Santa Catarina (UDESC), Joinville, SC (Brazil)

    2017-04-15

    Plasma nitriding of tool steels improves the surface hardness due to formation of diffusion zone and/or compound layer. The process parameters such as temperature, gas composition and dwell time, allow to control the layer thickness, the microstructure, the crystalline phases and the type of layer (for example white layer or diffusion zone). This paper discusses an alternative procedure for the heat treatment of tempering and surface treatment, both in plasma or combining conventional heat treatment with subsequent plasma nitriding. Carrying out both treatments in plasma could enable reduction in manufacturing costs, lower energy consumption and less time for tools manufacturing. Samples of VF800AT steel were treated and characterized (at surface and core of samples) through the following technique: X-ray diffraction, optical microscopy, scanning electron microscopy, micro-hardness profile and Rockwell C measurement. Temperature measurements during the plasma treatment, show that arise thermal gradient between the surface and the core of the samples. In this work, it was observed that the surface was up to 7% hotter than the core of sample, during the plasma treatment with temperature of magnitude about 5 x 10{sup 2} °C. This thermal gradient seems inherent to the plasma process, so that it can produce different microstructure, hardness and crystalline phases between core and edge of samples. However, when two tempering operations are prior carried out in a muffle furnace and the third tempering treatment is subsequently carried out simultaneously with the plasma nitriding, it is observed that the microstructure, the crystalline phases, hardness and micro hardness (in both, edge and core) are similar to treatments done in conventional mode cycle (in muffle furnace) with subsequent plasma nitriding. (author)

  7. Ductilidad y tenacidad de un borde cortado por plasma en una chapa de acero S460M de 15 mm de espesor

    OpenAIRE

    Aldazabal, J.; Martín-Meizoso, A.; Cicero González, Sergio; Klimpel, A.; Bannister, A.

    2015-01-01

    Los procesos de corte (y soldadura) son sin duda traumáticos para la microestructura de los materiales, de los que se deriva su comportamiento mecánico. Además esto afecta a la superficie, lo que agrava el problema, pues con frecuencia son las zonas que soportan unos mayores esfuerzos. En este trabajo se propone determinar si un corte por plasma mejora o no su comportamiento mecánico (fundamentalmente de cara a su comportamiento en fatiga bajo cargas alternadas). Se presentan los resultado...

  8. Análisis multielemental secuencial de aleaciones mediante plasma de argón generado por acoplamiento inductivo de radiofrecuencia

    OpenAIRE

    Farías de Funes, Silvia

    1996-01-01

    En el presente trabajo se describe la caracterización espectroscópica y analítica de un espectrómetro óptico constituido por el acoplamiento de una fuente de plasma inductivo de argón (IPC) y un monocromador programable de alta resolución, aplicable a la determinación secuencial de Mg, Mn, Cr, Mo en aleaciones de aluminio y de base Cu-Ni. Después de una discusión general sobre las características fundamentales del dispositivo instrumental empleado, se consideran aspectos básicos relacionados ...

  9. Ablation and formation by plasma of silver metallic films on poly aniline; Ablacion y formacion por plasma de peliculas metalicas de plata sobre polianilina

    Energy Technology Data Exchange (ETDEWEB)

    Palacios, J.C.; Olayo, G.; Morales, J.; Cruz, G.J. [Posgrado en Materiales, Facultad de Quimica, UAEM, Paseo Colon esq. Tollocan, Toluca, Estado de Mexico, C.P. 50000 (Mexico)

    2000-07-01

    This work shows a study about the ablation by plasma conditions in which is possible to form silver layers over polymeric surfaces with the purpose to increase the electric conductivity of the surface. The adhesion between layers formed by polymerization and ablation by plasma respectively is high, with this it is possible to find adequate conditions for getting the polymerization and ablation simultaneously forming with this a thin polymer matrix which would have metallic elements dispersed in its structure. (Author)

  10. Emissions treatment of diesel engines by plasma outside of balance; Tratamiento de emisiones de motores diesel por plasma fuera de equilibrio

    Energy Technology Data Exchange (ETDEWEB)

    Pacheco P, M.; Pacheco S, J.; Valdivia B, R.; Garcia R, M.; Estrada M, N. [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Santana D, A. [Instituto Tecnologico y de Estudios Superiores de Monterrey, Mexico D. F. (Mexico); Lefort, B.; Le Moyne, L.; Zamilpa, C., E-mail: marquidia.pacheco@inin.gob.mx [Institut Superieur d l' Automobile et des Transports, 49 rue Madeimoiselle Bourgeois BP31, 58027 Nevers cedex (France)

    2013-07-01

    Nowadays, diesel engines are greatly developed in automobiles allowing the reduction of carbon dioxide emissions (CO{sub 2}); however high emissions of particulate matter (Mp) and nitric oxides (NO{sub x}) still remain. A technology based on non-thermal plasma to diminish toxic emissions is exposed in this work. From previous experimental and simulation results, a chemical mechanism is proposed showing a rapidly diminution of Mp and NO{sub x}, in presence of plasma. (Author)

  11. Excitation of a plasma by high frequencies for illumination purposes; Excitacion de un plasma por altas frecuencias para propositos de iluminacion

    Energy Technology Data Exchange (ETDEWEB)

    Valdivia B, R

    2003-07-01

    The power electronics plays a very important paper so much in the national as international industrial development. For that reason, many of the works are focused in the one analysis and amplification of this area with the purpose of finding improvements in the existent systems and always looking for oneself end: the energy saving. Moreover, in the last years has occurred great interest to other very important area given their properties of energy profit, novelty and mainly their wide range of applications. This area is the study and use of the plasma. Many institutions with international recognition already invest and they develop systems in these two big areas of the technology among those that is the National Institute of Nuclear Research (INlN) with some laboratories dedicated to the work of the plasma, one of them the Laboratory of Thermal Plasma Applications (LAPT). The conjugation of both areas was analysed and developed in the present work with the one purpose of designing a system to generate thermal plasma and to give him one or but applications like it is to produce a luminous source as like to degrade organic gases as the Methane or Acetylene. This was developed by means of a resonant inverter with the help of MOSFET IRFK2D450 transistors and a load L C in a serial-parallel configuration with the purpose to profit their condition of resonance to have the maximum transfer of energy to the plasma. For to have a best profit of the energy it was realized an analysis of design for to oblige to the transistors to commute in zero voltage (ZVS) and to avoid then lost of power of C A. (Author)

  12. Application of laser-produced-plasmas to determination of carbon content in steel; Aplicacion de los plasmas generados por laser a la determinacion de carbono en aceros

    Energy Technology Data Exchange (ETDEWEB)

    Ortiz, M; Aragon, C; Aguilera, J A; Campos, J

    1994-07-01

    This paper describes an analytical method to determine carbon content in solid and molten steel. It is based on the study of the emission spectrum from a Nd-YAG laser produced plasma. The light emitted from the plasma is focused to the entrance slit of a spectrometer and detected by an OMA III system. For every laser pulse an spectral range of 100 A are recorded. With the use of time-resolved spectroscopy a precision of 1.6 % and a detection limit of 65 ppm of carbon content in steel have been obtained. These values are similar to those of other accurate conventional techniques but using optics fiber and laser excitation it is possible to made sample calibrations in hostile environments. Also, as the analysis are made in real time changes in sample composition can be measured without stopping production processes. (Author) 26 refs.

  13. Synthesis by plasma and characterization of semiconductor compounds derived of polyacetylene; Sintesis por plasma y caracterizacion de compuestos semiconductores derivados del poliacetileno

    Energy Technology Data Exchange (ETDEWEB)

    Vasquez, M.; Cruz, G. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico); Timoshina, T. [ESIQIE-IPN, 07738 Mexico D.F. (Mexico); Olayo, R. [UAM-I, 09340 Mexico D.F. (Mexico)

    2003-07-01

    In this work it is made a study of the structure and electric properties of chlorate polyethylene (PE-CI) with double and simple bonds obtained by continuous plasma with resistive coupling to 13.5 MHz. The synthesis conditions are power between 10 and 14 W and pressure of (6-7) x 10{sup -2} Torr. The synthesized PE-Cl in that way is soluble in acetone what indicates that probably is formed of short chains and not it shows the generalized inter crossing that is presented in some syntheses by plasma and that it can degrade the electric properties of these polymers. The IR and XPS analysis show the vibration of the C-C, C=C and C-CI bonds. The morphology of the polymer after being dissolved shows a compact and flat configuration. The electric conductivity has an approximately lineal behavior in an interval of 35 to 90% of relative humidity. (Author)

  14. Hydrolytic study of the copolymer Poly pyrrole/ Polyethyleneglycol and Poly pyrrole synthesized by plasma; Estudio hidrolitico del copolimero polipirrol/polietilenglicol y polipirrol sintetizado por plasma

    Energy Technology Data Exchange (ETDEWEB)

    Colin, E.; Enriquez, M.A.; Olayo, M.G.; Cruz, G.J.; Carapia, L.; Romero, M. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico); Morales, J.; Olayo, R. [UAM-I, A.P. 55-534 Iztapalapa, Mexico D.F. (Mexico)

    2006-07-01

    In this work the study about the hydrolytic compatibility of semiconductor polymers, copolymer Poly pyrrole/ Polyethyleneglycol (PPy/PEG) and Poly pyrrole (PPy) for their possible use as biomaterials. The polymers were synthesized by plasma between 10 and 100 W, with discharges of splendor RF to 13.5 MHz with resistive coupling. The hydrolytic affinity was evaluated calculating the contact angle with solutions of NaCl, NaCl-MgSO{sub 4} and Krebs-Ringer. The results show a hydrophilicity increment due to the increase of the surface ruggedness with the synthesis energy. On the contrary, the crystallinity diminishes when increasing the power in PPy and it stays approximately constant in PPy/PEG. The electric conductivity presents a growth from 2 to 4 magnitude orders in function of the water content in the polymers. (Author)

  15. Study of the chlorine as dopant in synthesized polymers by plasma; Estudio del cloro como dopante en polimeros sintetizados por plasma

    Energy Technology Data Exchange (ETDEWEB)

    Vasquez, M.; Cruz, G.; Olayo, M.G. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico); Timoshina, T. [ESIQIE, IPN, 07738 Mexico D.F. (Mexico); Morales, J.; Olayo, R. [UAM-I, 09340 Mexico D.F. (Mexico)

    2003-07-01

    In the search of new and better dopants for semiconductor polymers, in this work the synthesis by plasma and the characterization of two doped polymers with chlorine, Pyrrole (PPy) and Thiophene (PTh) is presented. The characterization of the polymers it was carried out by FT-lR, it shows the C-Cl vibration that it is confirmed with the X-ray photoelectron spectroscopy technique (XPS). The elementary analysis shows a greater quantity of Cl in the PTh-CI compared with PPy-CI. However, this effect is not reflected in the electric conductivity since the PTh-Cl presents a lightly greater conductivity than the PPy-CI. SEM shows a formed structure of small agglomerated spheres of different size. (Author)

  16. Absorption-desorption of drugs in porous polymers obtained by plasma; Absorcion-desorcion de farmacos en polimeros porosos obtenidos por plasma

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez T, M.

    2016-07-01

    A study about drug absorption and release in plasma polymers is presented in this work, these materials can be used as implants in the human body. In these applications the polymer should be biocompatible and/or biodegradable. Poly pyrroles and poly allylamine s synthesized by plasma have amine groups in their structure which makes them biocompatible with potential as drug carriers. In this function, the polymers were lyophilized to induce pores where the drug can be hosted. Drug-polymer mixtures with 1:10 ratio were prepared. The mixture morphology was studied by Scanning Electron Microscopy while their chemical structure was studied by Infrared Spectroscopy and X-ray Photoelectron Spectroscopy. Two models were studied to assess drug release, dynamic and static, in two solutions: water and Krebs Ringer (Kr) using the UV characteristic absorbance of each drug. In the static model release, 5 mg of the mixture were placed in 10 ml of solution. In the dynamic model, the release was performed with 5 mg of the mixture in 10 ml of solution, 1.5 ml of release medium was removed for UV analysis and replaced with an equal volume of fresh medium. The results indicate that the morphology of the polymers was modified with the lyophilization, in Poly pyrrole pores were induced with diameter in the range of 0.7 to 19 μm, while in Polyallyl amine the surface changed from smooth to rough. Drugs were absorbed in Poly pyrrole by filling the pores first and then coating the polymer with a drug layer. In Poly allylamine the drugs adhered to the polymer surface. Analyzing the atomic orbitals of the mixtures, it was found that the drugs interacted with the polymer. The most affected orbital was S2p, whose separation between 1/2 and 3/2 sub orbitals increased from 0.9 eV in Dapsone and Heparin to 4 eV in the mixtures, where the oxidation state changed from valence 6 to 6 and 2 in the mixtures. This suggests physicochemical interaction between drug and polymer. The drugs were released

  17. Plasma coatings of nitrogen polymers on metal prostheses of the circulatory system; Recubrimientos por plasma de polimeros nitrogenados sobre protesis metalicas del sistema circulatorio

    Energy Technology Data Exchange (ETDEWEB)

    Gomez J, L. M.

    2016-07-01

    This work has a study about the synthesis of poly aniline, poly allylamine and poly pyrrole doped with iodine onto metallic surfaces similar to stents for the circulatory system. Ar, water and hydrogen peroxide plasmas were used for eroding, conditioning and synthesizing polymers that potentially reduce some rejection reactions when stents are implanted in the human body. Stents are small metallic meshes that applied inside collapsed arteries or veins enlarge the diameter and restore the blood flow, however the metallic surfaces usually cause rejection reactions that obstruct the veins again. To give solutions to this problem, in this work is studied the synthesis of biocompatible polymer coatings on the stents that resist the blood flow forming a biocompatible interface between metal and blood. The metallic substrates were eroded and chemically prepared with Ar, H{sub 2}O and/or H{sub 2}O{sub 2} glow discharges on which the polymers were synthesized by plasma. The coatings were morphologically characterized by optical, scanning electron and atomic force microscopy, the chemical structure was studied by infrared and photoelectron X-ray spectroscopy. The hydrophilicity was studied measuring the advance static contact angle and the adhesion was evaluated indirectly with scanning electron microscopy after two months submerged in buffered phosphate solutions. The results indicate that the polymers grew following the superficial morphology; that the conditioning with Ar ions erode the substrates and that the conditioning with H{sub 2}O or H{sub 2}O{sub 2} erodes and activates the surface generating oxygen bridges which help in the polymer-metal adhesion. The chemical structure of the polymeric coatings contain crosslinked structures that correspond to links between monomers with the participation of all atoms, states that suggest monomer fragmentation and oxidation and states that indicate oxygen bridges in the polymers. The coatings had contact angles close to 90

  18. Structure of organometallic compounds obtained by plasma of titanium isopropoxide; Estructura de compuestos organometalicos obtenidos por plasma de isopropoxido de titanio

    Energy Technology Data Exchange (ETDEWEB)

    Arreola R, M. L.

    2012-07-01

    This work presents a study on the synthesis and characterization of organometallic compounds of titanium oxide obtained from glow discharges of titanium tetraisopropoxide (TTIP) and water on glass and polyethylene. The objective is the synthesis of titanium oxide particles which can be fixed on different supports for use in further studies of contaminants degradation in effluent streams. The synthesis was carried out by plasma in a glass tubular reactor of 750 cm{sup 3} and 15 cm length at 10{sup -1} mbar with power between 100 and 150 W during 2, 3 and 4 h. The precursors were TTIP and water vapor. TTIP is an organometallic compound composed of a central atom of Ti surrounded by 4 O atoms, which in turn are connected with chains of 3 C (propane s). The objective is the use of plasma collisions to separate the organic and inorganic phases of TTIP, so that both structure independently in a single material. The result was the formation of white titanium oxide powder composed with agglomerates of spherical particles with average diameter between 160 and 452 nm adhered to small films. The agglomerates have a tendency to change from film to particles with the energy applied to the synthesis. The study of the chemical structure showed a great presence of O{sub 2}-Ti-O{sub 2} (Ti surrounded by O) which can be found in most titanium oxides. Other chemical groups belonging to the organic phase were C=C=C, C=C=O and C{sub 2}-C-Ch appearing from the dehydrogenation of TTIP, which can be a possible precursor of this reactions kind. The structural superficial analyses showed that the atomic composition varies according to type of substrate used. The greatest content of Ti was obtained on glass substrates. However, the synthesis conditions had not evident effect in the participation of chemical states found in the inorganic phase. The crystalline studies indicated that the material is amorphous, although the de convoluted X-ray spectra showed that the synthesized titanium oxides

  19. Thallium Analysis in Environmental Samples by Inductively Coupled Plasma Mass Spectrometry; Analisis de Talio en Muestras Ambientales por Espectrometria de Masas con Fuente de Plasma de Acoplamiento Inductivo

    Energy Technology Data Exchange (ETDEWEB)

    Higueras, I; Fernandez, M; Conde, E; Gajate, A

    2008-08-06

    Due to its high toxicity, thallium has been considered by the US Environmental Protection Agency as one of the priority pollutants to be controlled. While being a highly toxic element, thallium has been studied to a much lesser degree than other toxic elements, mainly because thallium is often undetected by classical analytical methods. Thallium is a rare and dispersed element that occurs mainly in sulfur-containing ores. Thus, it is a potential pollutant to surrounding environment, if Tl-rich mineral and/or their industrial wastes are not properly disposed. In this work an Inductively Coupled Plasma Mass Spectrometry analytical procedure has been developed in order to determine thallium in environmental solid samples and its application to the study of this element as a potential pollutant associated with natural and anthropogenic activities. The analytical procedure has been validated by the use of appropriate reference materials, and through the isotope dilution technique as a primary method of measurement. Finally, the developed procedure has been applied to several samples from a mining area, as one of the scenarios where thallium it is likely to occur. (Author) 87 refs.

  20. Synthesis of Carbon nano structures by plasma discharge; Sintesis de nanoestructuras de carbono por descarga de plasmaa

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez L, M L

    2007-07-01

    Due to the great quantity of applications of the carbon nano structures (NEC) in diverse areas like: synthesis of super-resistant materials, hydrogen storage, nano sensors generation and nano catalysts, it has seen the necessity to generate new processes of synthesis of this materials as well as to already improve those existent. The present work has as objective to optimize the NEC synthesis process by means of the electric arc method which uses alternating current to high frequencies (HF), obtaining relatively clean products; that is to say, it hardly presents amorphous material neither sludges. They stand out the obtaining of carbon nano fibers (NFC) by means of a luminescent-arch discharge, in a gas mixture of He-CH{sub 4} with 34% at. Ni/10.32% at.Y like catalyst; at a frequency of 42 kHz and low power (300 W). This method benefits the amass of the particles in both electrodes due to the high frequencies. The time of duration of the process oscillates between 5 and 20 minutes. The obtained product was characterized by scanning electron microscopy (MEB), transmission electron microscopy (MET) to determine the NEC type obtained and by X-ray diffraction analysis and Raman spectroscopy for determining the purity of the samples. The NFC is relatively free of amorphous coal. The surface and structural analysis indicates that the fibers have a half diameter of 80 nm. It is also made, a study by optical emission spectroscopy of plasma using the Swan band for determining the temperature. (Author)

  1. Sterilization of Normal Human Plasma and Some of its Fractions by Means of Gamma Rays; Esterilizacion del plasma normal humano y algunas de sus fracciones por medio de radiaciones gamma

    Energy Technology Data Exchange (ETDEWEB)

    López Martínez de Alva, L.; Crespo, Y M. [Cortina Comision Nacional de Energia Nuclear (Mexico)

    1967-09-15

    radiaciones ultravioleta. El otro metodo es el uso de la ß-propiolactona que se ha desechado tambien рог las alteraciones que producía en la estructura de las protefnas plasmáticas. El objeto de este trabajo, que debe considerarse como una nota preliminar, es presentar los resultados obtenidos al esterilizar por medio de radiaciones gamma ({sup 60}Co, 1,3316 MeV) con dosis variables de 2, 2,5 у 3 Mrad un producto que, como el plasma que contiene proteínas muy lábiles, podría ser fácilmente alterado en su estructura por la radiacion. Tambien se sometieron a las mismas dosis: fibrogeno puro, gamma globulina pura у albúmina de origen humano; los resultados fueron muy satisfacforios, ya que quedo de manifiesto que no se pudieron demostrar alteraciones apreciables en cuanto a su estructura, solubilidad у características bioquímicas. Mediante pruebas simples de coagulacion se puso de manifiesto que algunas de las proteínas que intervienen en este mecanismo, como la protrombina, el factor Power- Stuart у el factor Hageman, prácticamente no se alteraban. Todas las muestras de plasma у de las diferentes proteínas fueron previamente liofilizadas, procurando que el contenido máximo de humedad fuera de 0,034%, con el objeto de evitar la ionizacion del contenido de agua que la tiansformaría en agua oxigenada que alteraría у oxidaría las proteínas. Los plasmas liofilizados previamente contaminados con diferentes cepas у virus demostraron wue con dosis tan bajas como 2 Mrad quedaban esteriles. Por último, se puso de manifiesto que este es un metodo sencillo у práctico, ya que la esterilizacion puede verificarse en el envase final. (author)

  2. Estudio de polvos y recubrimientos metaestables de NiTi obtenidos por proyección térmica de plasma

    Directory of Open Access Journals (Sweden)

    Cano, I. G.

    2008-06-01

    Full Text Available NiTi intermetallic is widely known for its shape memory effect and pseudoelasticity. Due to its high corrosion resístanse (biocompatibility, most of the studies carried out deal with its use for medical applications. With regard to surface technologies, many reported investigations focus on Vacuum Thermal Spray to provide NiTi coatings with minimal oxide content.The Thermal Spray Center has attempted to obtain metastable NiTi powders and coatings by means of Atmospheric Plasma Spraying with a liquid nitrogen cooling system. Starting from two different Ni-45wt%Ti feedstock powders. One powder is a blend of Ti and Ni particles, whereas the other has been alloyed by gas atomization. Both powders were sprayed obtaining better results starting from the gas atomized powder resulting in a final deposit where NiTi was the main phase with minimal oxidation. Different spraying parameters were tested and microstructural characterization was performed by SEM-EDS. XRD patterns showed some peak broadening; that seems to be produced by structural metastability of the coatings.

    El compuesto intermetálico de NiTi es conocido por su capacidad de memoria de forma así como por su pseudoelasticidad. Debido, además, a su alta resistencia a corrosión (biocompatiblidad, la gran mayoría de estudios se centran en su uso para aplicaciones médicas. Dentro del conjunto de las tecnologías de superficie, las investigaciones actuales utilizan la técnica de Proyección Térmica de Plasma al Vacío para producir recubrimientos de NiTi con contenidos mínimos de porosidad y de óxidos.El Centro de Proyección Térmica se planteó como objetivo la obtención de polvos y recubrimientos metaestables de NiTi a través de la técnica de Proyección de Plasma acoplado a un sistema de refrigeración con nitrógeno líquido. Se estudiaron dos polvos con diferentes características, pero de la misma composición nominal (Ni-45 % peso Ti. Uno de ellos, es el resultado de

  3. Modelización y monitorización de procesos de refusión láser de recubrimientos depositados por plasma

    Directory of Open Access Journals (Sweden)

    Amado, J. M.

    2004-04-01

    Full Text Available This paper shows a theoretical and experimental study of the CO2 laser remelting of plasma sprayed coatings. The aim of the process is the decrease of the porosity to improve the layer properties. In a first approach simulation helps in finding the right process parameters, those parameters allow the melting of the sprayed layer and a minimal amount of substrate material to minimize dilution. The presented modelling includes several features allowing the description of phase transition in the remelting process, the main point is the use of different absorption coefficient in the two phases. Monitoring results gave additional information about the process and another way of doing process validation. The main result are is the prediction size and shape of the remelted layers and due to that the simulation code can be used in the parameter finding and plays an important role in the complete understanding of the process.

    Este artículo describe un estudio teórico y experimental del proceso de refusión, por láser de CO2, de recubrimientos depositados por plasma. Se trata de lograr mediante el proceso de refusión una buena unión metalúrgica entre recubrimiento y sustrato, entre las diferentes partículas que componen el recubrimiento y de este modo evitar que el recubrimiento sea frágil y tenga una baja adherencia con el sustrato. En una primera aproximación la modelización sirvió de ayuda para lograr los parámetros adecuados que permitiesen fundir toda la capa proyectada junto con una mínima porción del sustrato para minimizar el grado de dilución. La modelización presentada incluye algunos aspectos que ayudan a describir el cambio de fase asociado a la refusión, estos son la utilización de las propiedades termofísicas adecuadas y la variación del coeficiente de absorción en el paso de la fase sólida a la fundida. Los resultados de la monitorización refuerzan el conocimiento del proceso y ayudan a la validación del

  4. Análise Econômica e de Sensibilidade em um Povoamento Implantado no Sudoeste da Bahia

    Directory of Open Access Journals (Sweden)

    Aline Pereira das Virgens

    Full Text Available RESUMO A execução de um projeto florestal deve ser norteada por ferramentas de análise econômica, de forma que se possa respaldar os investimentos realizados. Objetivou-se neste trabalho promover uma análise econômica e de sensibilidade em projetos de reflorestamento de eucalipto na microrregião de Vitória da Conquista, BA. Utilizou-se como critério o Valor Presente Líquido, a Taxa Interna de Retorno, o Valor Periódico Equivalente e o Custo Médio de Produção. A análise de sensibilidade foi realizada através da variação da taxa anual de juros, da produção e do preço da madeira. O custo de implantação apresentou valor de 2.091,92 reais/ha. Se tratando do processo de condução, obteve-se um valor de 915,29 reais/ha, corrigidos para o ano zero. Apesar da característica de longo prazo, a atividade florestal constituiu alternativa de renda para os pequenos produtores, apresentando viabilidade econômica em todos os critérios avaliados.

  5. IDENTIFICACIÓN DE POLÍMEROS MEDIANTE ESPECTROSCOPIA DE EMISIÓN DE PLASMAS PRODUCIDOS POR LÁSER (LIBS

    Directory of Open Access Journals (Sweden)

    DANIEL DÍAZ

    2009-01-01

    Full Text Available Se espera que en Colombia en los próximos años se realicen misiones humanitarias para la remoción de Artefactos Explosivos Improvisados (AEI para asegurar el tránsito de personas y bienes, particularmente en zonas rurales. Entre las tecnologías que apoyan las labores de desminado humanitario, la espectroscopia de emisión de plasmas producidos por láser (LIBS tiene la capacidad de identificar explosivos y las cubiertas utilizadas en la fabricación de AEIs. En este trabajo la técnica LIBS se usó para identificar y caracterizar a nivel de laboratorio cinco polímeros que pueden ser usados en la fabricación de AEIs: polivinil cloruro, polietileno de alta densidad, polietileno tereftalato, poliestireno y polipropileno. Se utilizó el coeficiente de correlación lineal para la identificación de los polímeros. Se lograron identificar satisfactoriamente todos los polímeros al compararlos con librerías de distintas sustancias utilizando el promedio de cinco espectros en la ventana de análisis centrada en 255 nm.

  6. Manejo do cateter venoso central totalmente implantado em pacientes oncológicos: revisão integrative Manejo del catéter venoso central totalmente implantado en pacientes oncológicos: revisión integrativa Management of totally implanted catheter in patients with cancer: an integrative review

    Directory of Open Access Journals (Sweden)

    Christiane Inocêncio Vasques

    2009-10-01

    Full Text Available O cateter totalmente implantado é amplamente utilizado durante o tratamento de pacientes com câncer e é capaz de minimizar complicações decorrentes da terapia intravenosa periférica. Assim, buscou-se identificar os cuidados de enfermagem relacionados ao manuseio de cateter totalmente implantado nesses pacientes. Para tanto, realizou-se revisão integrativa da literatura que resultou na análise de 15 artigos. O conhecimento produzido está direcionado para o tempo de permanência do cateter, complicações inerentes ao uso, manuseio do dispositivo, percepção do paciente em relação ao cateter e informações ao paciente. Além de demonstrar a complexidade da assistência de enfermagem no manuseio desses dispositivos, os achados podem auxiliar, igualmente, os profissionais que não atuam em oncologia, na aplicação de conhecimentos na prática clínica.El catéter totalmente implantado es ampliamente utilizado durante el tratamiento de pacientes con cáncer y es capaz de minimizar las complicaciones consecuentes de la terapia intravenosa periférica. Así, en este trabajo, se buscó identificar los cuidados de enfermería relacionados a la manipulación del catéter totalmente implantado en esos pacientes. Para tal efecto, se realizó una revisión integrativa de la literatura dando como resultado el análisis de 15 artículos. El conocimiento producido está orientado hacia el tiempo de permanencia del catetér, complicaciones inherentes al uso, manipulación del dispositivo, informaciones y percepción del paciente en relación al catéter. Aparte de demostrar la complejidad de la asistencia de enfermería en la manipulación de esos dispositivos, los hallazgos pueden auxiliar, igualmente, a los profesionales que no actúan en oncología, en la aplicación de conocimientos en la práctica clínica.Totally implanted catheter, which is effective in deceasing complications related to peripheral intravenous therapy, is widely used in

  7. Evaluación experimental de la resistencia a la corrosión de un acero aisi-sae 4140 implantado con iones de nitrógeno

    OpenAIRE

    PEÑA, DARIO; FONTALVO, PAOLA; ESTUPIÑAN, HUGO; NIÑO, DANNIER; VESGA, WILSON

    2010-01-01

    Se estudió la resistencia a la corrosión de un acero AISI-SAE 4140 implantado con iones de Nitrógeno mediante la técnica 3DII (Implantación Iónica Tridimensional). Se evaluaron diferentes rugosidades de las muestras implantadas mediante técnicas electroquímicas de Rp, EIS y Tafel en una salmuera al 3% de NaCl, donde se obtuvo la mayor resistencia a la corrosión para el material implantado con menor rugosidad. Se produjo la formación de una posible capa protectora estable con la inmersión de l...

  8. Método analítico para a determinação de meloxicam em plasma humano por cromatografia líquida de alta eficiência (CLAE Determination of meloxicam in human plasma by HPLC

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    Valentina Porta

    2005-06-01

    Full Text Available Desenvolveu-se e validou-se método analítico simples, rápido e específico para quantificação de meloxicam (inibidor da COX-2 em plasma humano através da cromatografia líquida de alta eficiência, para aplicação em estudos de bioequivalência. Piroxicam foi utilizado como padrão interno. Empregou-se cromatografia em fase reversa com coluna modelo Synergi RP-MAX (150 x 4,6 mm, à temperatura de 30 ºC e fase móvel constituída por mistura de acetonitrila e tampão fosfato 0,025 mol/L pH 4,5 (40:60, v/v, a um fluxo de 1,0 mL/min. Os analitos foram detectados por UV a 364 nm. As amostras de plasma foram acidificadas com ácido clorídrico 1 mol/L, extraídas utilizando-se éter terc-butil metílico e, após filtração e secagem, o resíduo foi reconstituído em 250 mL de fase móvel para injeção em CLAE. Os tempos de retenção para meloxicam (padrão e piroxicam (padrão interno foram 3,35 e 4,19 minutos, respectivamente. Este método apresentou linearidade na faixa de concentração entre 50-4000 ng/mL (R² = 0,9995, com limite de quantificação inferior de 50 ng/mL e exatidão de 114%. O método analítico desenvolvido neste trabalho demonstrou especificidade, linearidade, precisão e exatidão adequadas, permitindo sua aplicação em ensaios de bioequivalência.A simple, rapid and specific high-performance liquid cromatographic (HPLC method was developed and validated to estimate meloxicam (COX-2 inhibitor levels in human plasma. Piroxicam was used as internal standard. Reversed phase chromatography was conducted using a Synergi RP-MAX (150 x 4.6 mm column at 30 ºC and a mobile phase of acetonitrile and 0.025 mol/L pH 4,5 phosphate buffer (40:60, v/v, at a flow rate of 1mL/min. Analytes were detected at 364 nm. Plasma samples were acidified with 1 mol/L hydrochloric acid and extracted with tert-butyl methyl ether, evaporated to dryness, reconstituted in 250 mL of mobile phase and injected in the column. The retention time of

  9. Uso de cateteres venosos totalmente implantados para nutrição parenteral: cuidados, tempo de permanência e ocorrência de complicações infecciosas Long-term central venous catheter for total parenteral nutrition: catheter care, permanence period, and incidence of infections

    Directory of Open Access Journals (Sweden)

    Maria do Rosário Del Lama de Unamuno

    2005-04-01

    Full Text Available Cateteres venosos totalmente implantados são utilizados em pacientes com síndrome do intestino curto, para realizar o suporte nutricional parenteral, o qual mantém estes pacientes vivos, pois fornece-lhes nutrientes que são absorvidos pela via digestiva. No entanto, estes cateteres não são isentos de complicações. As infecções relacionadas aos cateteres venosos são as complicações mais temidas e sua incidência varia de 3% a 20%, aumentando em pacientes mais graves. O objetivo do presente estudo é descrever as complicações infecciosas em pacientes recebendo nutrição parenteral por meio de cateteres venosos totalmente implantados. Tais cateteres são utilizados pela Divisão de Nutrição Clínica do Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, para realizar o suporte nutricional parenteral em pacientes submetidos a ressecções extensas de intestino delgado. Foram avaliadas as complicações infecciosas ocorridas com 21 cateteres, implantados em 16 pacientes. O tempo de permanência dos cateteres foi de 768±664,3 dias (mediana 529 dias e a taxa de infecção foi de 0,029 infecções/paciente/ano, resultados que se comparam às taxas de infecção observadas em países desenvolvidos. Concluiu-se que os cuidados observados no manuseio destes cateteres foram de fundamental importância para diminuir a incidência de infecção nestes pacientes.Long-term venous catheters are used for the total parenteral nutrition infusion, which is essential for feeding short-bowel syndrome patients. However, complications are likely to occur. The incidence of catheter related infections ranges from 3 to 20% in hospitalized patients. The Divisão de Nutrição Clínica do Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto, University of São Paulo, Brazil, has been providing nutrition support to short-bowel syndrome patients, using totally implantable venous catheters. This is a

  10. INFLUENCIA DE LA NITRURACIÓN POR PLASMA SOBRE EL COMPORTAMIENTO A LA CORROSIÓN Y LA ADHESIÓN DE RECUBRIMIENTOS DLC SOBRE ACERO INOXIDABLE AISI 420

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    Jorge N. Pecina

    2016-01-01

    Full Text Available En este trabajo se estudió el comportamiento a la corrosió n y la adhesión de dos rec ubrimientos DLC (“Diamond Like Carbon ” , “Soft” y “Hard”, depositados por PACVD (“Plasma Assisted Chemical Vapour Deposition” sobre acero AISI 420, templado y revenido y /o nitrurado por plasma . Se analizaron por espectroscopía Raman y midió dureza en superficie. Se observó la microestructura por OM y SEM. Se realizaron pruebas de adhesión con indentación Rockwell C . S e practicaron ensayos de Niebla Salina e inmersión en HCl . Los DLC “ Soft ” presentaron una dureza de 5 00 HV y un espesor de 2 0 μm , mientras que los “ Hard ” tuvieron 1400 HV y 2 ,5 μm. Ambos recubrimientos presentaron bajo coeficiente de fricción y buena adhesión sobre el sustrato nitrurado . También presentaron buena resistencia a la corrosión atmosférica. En HCl el DLC retardó la degradación que se presentó rápidamente en las muestras sin recubrir.

  11. Standardization of the method for measurement of plasma estrone by radioimmunoassay; Padronizacao do metodo de dosagem de estrona plasmatica por radioimunoensaio

    Energy Technology Data Exchange (ETDEWEB)

    Vilanova, M.S.V.; Moreira, A.C.; Sala, M.M. de; Sa, M.F.S. de [Sao Paulo Univ., Ribeirao Preto, SP (Brazil). Faculdade de Medicina

    1994-10-01

    The present paper has as objective standardize a radioimmunoassay method for measurement of plasma estrone. Ethyl ether was used for plasma extraction. The sensitivity (Minimal detectable dose) was 3,7 pg/tube; the reproducibility (inter assay error) was 8,6%; the precision (intra assay error) was 4,1%. As a biological control the plasma estrone was ml and in 24 patients with polycystic ovarian syndrome (median = 77,9 pg/ml). (author). 6 refs, 2 figs, 2 tabs.

  12. 57. El menor número de células progenitoras endoteliales en la sangre periférica de pacientes coronarios no está relacionado con una disfunción in vitro inducida por su plasma

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    A. González Rocafort

    2010-01-01

    Conclusiones: Los pacientes coronarios tienen un menor nivel preoperatorio de EPC que los valvulares. La disfunción en cultivo de las EPC de pacientes ateroscleróticos no se observa en EPC cultivadas obtenidas de donantes sanos tras la incubación con plasma de pacientes coronarios, y, por lo tanto, podría ser debida más a factores intrínsecos de estas células en su procedencia de la médula ósea que a factores del medio.

  13. Weed control in young coffee plantations through post emergence herbicide application onto total area Controle de plantas daninhas em cafezais recém-implantados, com herbicidas aplicados em pós-emergência em área total

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    C.P. Ronchi

    2004-12-01

    at doses recommended for bean crop, these herbicides may be applied to control weeds in coffee and bean intercropping systems by spraying the entire area.Este trabalho foi realizado com o objetivo de investigar, em campo, a eficiência de vários herbicidas aplicados em pós-emergência em área total no controle de plantas daninhas, em cafezais recém-implantados e no consórcio de café e feijão, assim como seus efeitos sobre essas culturas. Mudas de Coffea arabica, cultivar Catuaí Vermelho, com quatro a seis pares de folhas foram transplantadas para o campo e cultivadas segundo práticas agronômicas usuais. O consórcio de café e feijão foi obtido por meio do plantio de três linhas de feijão nas entrelinhas do cafezal. Quando os herbicidas foram aplicados sobre as culturas, as plantas de café estavam com seis a dez pares de folhas, as de feijão com três folíolos e as plantas daninhas no estádio inicial de desenvolvimento. Fluazifop-p-butil e clethodim foram seletivos às plantas de café e controlaram eficientemente Brachiaria plantaginea e Digitaria horizontalis. Plantas daninhas dicotiledôneas (Amaranthus retroflexus, Bidens pilosa, Coronopus didymus, Emilia sonchifolia, Galinsoga parviflora, Ipomoea grandifolia, Lepidium virginicum e Raphanus raphanistrum foram controladas eficientemente por aplicações isoladas de fomesafen, flazasulfuron e oxyfluorfen, com exceção de B. pilosa, C. didymus e R. raphanistrum para o oxyfluorfen. Aplicações seqüenciais com intervalos de sete dias de fomesafen + fluazifop-p-butil ou clethodim, e as duas misturas comerciais de fomesafen + fluazifop-p-butil controlaram simultaneamente ambos os tipos de plantas daninhas. Cyperus rotundus foi controlada apenas por flazasulfuron. Com exceção de fluazifop-p-butil e clethodim todos os demais tratamentos herbicidas provocaram apenas leves injúrias às folhas mais novas das plantas de café. Contudo, o crescimento das plantas não foi prejudicado, de forma que tanto a

  14. Joule Heating of Plasma in the Toroidal Tokamak-3 Device; Chauffage du Plasma par Effet Joule, dans l'Installation Torique; Dzhoulev nagrev plazmy na toroidal'noj ustanovke Tokamak-3; Calentamiento de un Plasma por Efeto Joule en la Instalacion Toroidal Tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Arcimovich, L. A.; Afrosimov, V. V.; Gladkovskij, I. P.; Mirnov, S. V.; Petrov, M. P.; Strelkov, V. S. [Institut Atomnoj Ehnergii, Im. I.V. Kurchatova, Moskva, SSSR (Russian Federation)

    1966-04-15

    la colonne, qui peut s'expliquer par la presence, a l'interieur de la colonne, de flux de derive d'ions ayant de grandes vitesses transversales. (author) [Spanish] En la instalacion Tokamak-3 el plasma de hidrogeno se obtiene y calienta con una corriente electrica anular de 40 a 60 kA. El tiempo de paso de la corriente es de 20 a 30 ms. Muchos de los experimentos se efectuaron con un campo magnetico longitudinal estabilizado de 25 kOe. La componente transversal del campo magnetico disperso se compenso con ayuda de corrientes procedentes de circuitos correctores especiales. Durante la descarga no tuvo lugar ningun desplazamiento perceptible del centro de la columna con respecto al plano ecuatorial del toro y se observo una deriva de la columna de plasma 'hacia el exterior' (aumento del radio mayor del circuito). Este movimiento puede ser provocado por un cambio del radio de la columna de corriente, por el calentamiento del plasma o por el amortiguamiento de las corrientes de Foucault en el recipiente conductor. En estas condiciones, se consiguio obtener en la instalacion Tokamak-3 una columna de plasma macroscopicamente estable; sin embargo, la temperatura del plasma fue inferior a la que era de esperar en ausencia de perdidas anomalas de energia. Los procesos que tienen lugar durante la interaccion de la columna plasmatica con el diafragma originan grandes perdidas de energfa. Esta interaccion pudo atenuarse dando al diafragma una forma especial y utilizando la propiedad de la columna de desplazarse hacia el exterior en el transcurso del proceso. El problema investigado consistia en determinar varios parametros del plasma en estas condiciones, en particular las temperaturas electronica y ionica. Para determinar la temperatura electronica basandose en los cambios de la resistencia del plasma, es preciso conocer ademas de las caracteristicas electricas de la columna, la ley que rige el cambio del radio de esta ultima en funcion del tiempo. La solucion, utilizando un

  15. About of the Electrostatic fields excitation theory by a RF wave in a plasma; Acerca de la teoria de excitacion de campos electrostaticos por una onda de rf en un plasma

    Energy Technology Data Exchange (ETDEWEB)

    Gutierrez T, C.R

    1991-01-15

    In an unidimensional model is shown in the cases of a semi limited plasma and a layer of plasma the excitement mechanism of electrostatic fields for a radiofrequency wave (RF) polarized lineally. This phenomenon depends strongly on the combined action of the Miller force and that of impulsion. It is shown that the action of these forces is carried out in different characteristic times when the front of wave crosses through the plasma. The cases of a semi limited plasma and of a layer of plasma without and with current are analyzed. It is shown that near the frontiers of the plasma where the field is sufficiently big arise oscillations of the width of the field that are slowly muffled in the space in an exponential way. In the cases of a plasma layer its are shown that the processes that arise near the frontier x = L are similar to the processes that arise near the frontier x = 0. The existence of current in the plasma layer leads to the blockade of the excited perturbations in the frontier x = L. (Author)

  16. Flute Characteristics of and Microwave Emission from a Plasma in a Mirror; Instabilite en Cannelures et Emission de Micro-Ondes par un Plasma dans une Machine a Miroirs; Zhelobkovye kharakteristiki i ehmissiya mikrovoln iz plazmy v zerkale; Caracteristicas del Estriado y Emision de Microondas por un Plasma en un Espejo

    Energy Technology Data Exchange (ETDEWEB)

    Scott, F. R.; Jensen, T. H.; Wharton, C. B. [General Atomic Division, General Dynamics Corporation, San Diego, CA (United States)

    1966-04-15

    , si l'energie des electrons est suffisamment superieure a celle des ions. L'addition de plaques conductrices dans la region aval du miroir a pour effet d'attenuer la violence de l'instabilite en cannelures. Cette attenuation ne depend que de la resistance surfacique de ces plaques. Les auteurs ont etudie cet effet en mesurant le spectre de frequence des signaux en provenance de sondes a sintillateur enrobe placees au voisinage de l'enceinte a vide. (author) [Spanish] Los autores construyeron un espejo pulsado para estudiar la estabilidad de un plasma de modesta energfa. El plasma de 70 eV se inyecta mediante un cation en el espejo, con ayuda de un campo de gufa octopolar de tipo lineal. El campo especular se aplica durante un lapso igual al tiempo de transito del plasma. En el plano central del espejo se alcanzan densidades de plasma iguales a 10{sup 13} electrones/cm{sup 3}. Se observan dos modos definidos de operacion, dependientes exclusivamente de las condiciones establecidas en el campo de gufa. Segun el primer modo, en el espejo el plasma no sufre estriado alguno, la mayor parte del mismo escapa en direccion axial, se observa una lenta, y anomala difusion radial y se emiten microondas en los ar- . monicos ciclotronicos de los electrones, desde n = 1 hasta por lo menos n = 19. La emision de microondas no es compatible con la rama electronica de la inestabilidad de Harris. La estabilidad de este modo se atribuye a la union lineal por el plasma frio que sale por efusion de la zona del campo de gufa. En la zona comprendida entre el espejo y el campo de gufa, se observaron densidades superiores a 10{sup 11} electrones/cm{sup 3} durante 200 {mu}s. Esta densidad disminuye al agregar al campo de gufa un cilindro de simetria axial. Al cabo de 40 us, las mediciones ponen de manifiesto en esta zona densidades de plasma inferiores 10{sup 11} electrones/cm{sup 3}. El plasma resultante, atrapado en el espejo presenta inestabilidades en forma de estrias, perdidas radiales

  17. Resolidificación con láser de barreras térmicas de circona depositadas por proyección térmica plasma (APS

    Directory of Open Access Journals (Sweden)

    Diez, J. C.

    2004-12-01

    Full Text Available Coatings of partially stabilised zirconia are currently used as thermal barrier coatings in gas turbines and diesel engines. Zirconia coatings are usually processed via plasma spraying a well-established and relatively cheap technique. Thermal barrier coatings consist of 0.5 to 1 mm of porous ceramic bonded to the metallic substrate by a bond-coat. High porosity in the ceramic coating assure a good thermal behaviour but increases the chances for corrosion or chemical attack of the bondcoat and coating detach by delamination processes. The as sprayed surface is rough and sensitive to erosion. In the present work we obtained the processing conditions for laser remelting of Y-PSZ coatings deposited by atmospheric plasma spraying technique on Ni- alloys. A simple model accounts for the onset melting energy and its dependence with the processing speed. The remelted film is dense and with smooth surface and well bonded to the underlying porous coat.

    Los recubrimientos de circona parcialmente estabilizada con itria se usan habitualmente como barreras térmicas en turbinas y motores. Estos recubrimientos se suelen realizar mediante proyección térmica plasma (APS, una técnica relativamente económica y bien conocida en el sector industrial. Las barreras consisten de una capa de 0.5 a 1 mm de cerámica muy porosa unida a la aleación metálica mediante una capa de enlace. La elevada porosidad permite incrementar la resistencia al choque térmico pero provoca que el oxigeno u otros gases perniciosos para el substrato lleguen con relativa facilidad, produciéndose ataques que pueden acelerar el proceso de delaminación. Asimismo la superficie es rugosa y por tanto expuesta a la erosión por partículas. En este trabajo se presentan las condiciones óptimas que permiten la resolidificación mediante láser de la superficie de las capas de Y-PSZ (circona parcialmente estabilizada con itria depositadas por proyección térmica de plasma en aleaciones

  18. Implante de stent dentro de stent recém-implantado em ponte de veia safena para otimização do resultado angiográfico Stenting a stent in saphenous vein graft to optimize the angiographic result

    Directory of Open Access Journals (Sweden)

    Antonio Esteves Fº

    1998-03-01

    Full Text Available Mulher de 60 anos, com angina progressiva e revascularização do miocárdio, há oito anos, com ponte de veia safena para coronária direita e anastomose de artéria mamaria esquerda para artéria descendente anterior. Submetida a implante de stent Gianturco-Roubin II em terço proximal da ponte de veia safena para artéria coronária direita, com resultado insatisfatório pela persistência de lesão residual, provavelmente, decorrente de prolapso para dentro da luz de material aterosclerótico através dos coils. Foi implantado outro stent (Palmaz-Schatz biliar dentro do stent GRII com sucesso e ótimo resultado angiográfico. Um 2º stent Palmaz-Schatz biliar foi implantado em lesão distal no corpo da ponte, ultrapassando os dois stents, anteriormente implantados, com sucesso. Em algumas situações, implante de stent dentro de outro stent é recurso útil para otimização de resultado angiográfico do implante de um stent.A 60 year-old woman with progressive angina who had been submitted to saphenous bypass-graft to right coronary artery and a left mammary artery graft to anterior descending artery eight years previously, underwent implantation of a Gianturco Roubin II stent in the proximal third of the saphenous vein graft. The result was suboptimal by persistence of a residual stenosis probably due to prolapse of atherosclerotic material through the coil spaces. Another stent (Palmaz-Schatz biliar stent was implanted at the previously stented site with no residual stenosis. Another Palmaz-Schatz biliar stent was successfully implanted in the distal body of the graft to treat another lesion (passing through the previously stents without difficulty. Stenting a stent, in selected situations, is a useful tool to optimize the angiographic result of stent implantation.

  19. Influencia de los parámetros de proyección por plasma atmosférico en recubrimientos de YSZ obtenidos a partir de polvos micro y nanoestructurados

    Directory of Open Access Journals (Sweden)

    Carpio, P.

    2014-08-01

    Full Text Available In the present work, the influence of atmospheric plasma spray (APS parameters on the deposition of two commercial YSZ feedstocks, one conventional and one nanostrcutured, has been studied. First the study focused on how the variability of the different parameters affects the particle behaviour during spraying. For this purpose, a sensor which enables to measure the particle temperature and velocity inside the plasma was used. Once the spraying parameters influence was known, both powders were deposited by APS onto stainless steel substrates modifying the higher influencing parameters. These coatings have been characterised and the influence of the particle behaviour on the coating microstructure and properties has been analysed. This work concludes the spraying parameters variation affects on the particle velocity and temperature inside the plasma plume and this behaviour influences, in turn but in a different way, on the final coating characteristics when using different powders (micro- and nanostructured.En el presente trabajo se ha estudiado la influencia de cada uno de los parámetros de la proyección térmica por plasma atmosférico (atmospheric plasma spraying, APS en la deposición de dos polvos comerciales de YSZ, uno convencional y otro nanoestructurado. En primer lugar se ha estudiado cómo afecta la variabilidad de los diferentes parámetros en el comportamiento de las partículas durante la proyección. Para tal fin, se ha utilizado un sensor que permite determinar la temperatura y la velocidad de las partículas en el interior del plasma. Una vez conocido cómo influyen los parámetros de proyección se han depositado ambos polvos sobre sustratos de acero inoxidable mediante APS modificando aquellos parámetros con un mayor impacto en el comportamiento de las partículas. Estos recubrimientos han sido caracterizados y se ha analizado la influencia del comportamiento de las partículas durante la proyección en la microestructura y

  20. Adubação nitrogenada em milho implantado em semeadura direta após aveia preta Maize nitrogen fertilization in no-tillage system following black oat

    Directory of Open Access Journals (Sweden)

    Gilber Argenta

    1999-12-01

    Full Text Available A cultura do milho implantada em semeadura direta em sucessão a gramíneas, geralmente, apresenta deficiência inicial de nitrogênio (N. Ela é atribuída à imobilização microbiana de N durante o processo de decomposição da palha com alta razão C/N. Com a finalidade de diminuir esta deficiência, recomenda-se, para qualquer situação, a aplicação de 20 a 30kg/ha de N na semeadura. Porém, será que este manejo se aplica para todas as situações? O objetivo desta revisão é questionar a recomendação de aplicação de nitrogênio na semeadura do milho em sucessão à aveia preta e discutir a eficiência de outras três estratégias que têm sido utilizadas para diminuir a deficiência inicial de N nesta cultura. A disponibilidade de N para as culturas em sucessão é controlada pela intensidade dos processos opostos e simultâneos de imobilização e mineralização do N durante a decomposição de resíduos culturais pela população microbiana do solo. Ela é influenciada pela quantidade, tipo (razão C/N e manejo de resíduos, temperatura do solo, regime de água/aeração, pH e pelo teor de N no solo. Assim, a resposta do milho ao manejo do N está muito relacionada ao ambiente. Outras estratégias têm sido propostas com a finalidade de diminuir a deficiência inicial de N no milho quando implantado em sucessão à aveia preta. Pode-se destacar o atraso da época de semeadura após a dessecação da aveia, a aplicação de N nos estádios iniciais de desenvolvimento da aveia e a aplicação de N no manejo da aveia, ou seja, em pré-semeadura do milho. Portanto, a recomendação do manejo do N deve resultar de uma avaliação caso a caso, evitando-se generalizações.Maize crop sowed in no-tillage in succession to grasses, generally, presents initial deficiency of N. This is attributed to the microbial immobilization of N during the decomposition process of straw with high C/N ratio. With the objective of reducing this

  1. Plasma sintering of ferritic steel reinforced with niobium carbide prepared by high energy milling; Sinterizacao a plasma de aco ferritico reforcado com carbeto de niobio preparado por moagem de alta energia

    Energy Technology Data Exchange (ETDEWEB)

    Silva Junior, J.F. da; Almeida, E.O.; Gomes, U.U.; Alves Junior, C.; Messias, A.P. [Universidade Federal do Rio Grande do Norte (UFRN), Natal (Brazil). Lab. de Materiais Ceramicos e Metais Especiais; Universidade Federal do Rio Grande do Norte (UFRN), Natal (Brazil). Lab. de Processamento de Materiais por Plasma

    2010-07-01

    Plasma is an ionized gas where ions are accelerated from anode to cathode surface, where the sample is placed. There are a lot of collisions on cathode surface by ions heating and sintering the sample. High energy milling (HEM) is often used to produce composite particles to be used on powder metallurgy. These particles can exhibit fine particles and high phase dispersion. This present work aim to study ferritic steels reinforced with 3%NbC prepared by HEM and sintered on plasma furnace. Ferritic steel and NbC powders were milled during 5 hours and characterized by SEM, XRD and laser scattering. Then, these composite powders were compacted in a cylindrical steel die and then sintered in a plasma furnace. Vickers microhardness tests and SEM and XRD analysis were performed on sintered samples. (author)

  2. Transition probabilities for lines of Cr II, Na II and Sb I by laser produced plasma atomic emission spectroscopy; Probabilidades de transicion de algunos niveles de Cr II, Na II y Sb I medediante espectroscopia de plasma producidos por laser

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, A. M.; Ortiz, M.; Campos, J.

    1995-07-01

    Absolute transition probabilities for lines of CR II, Na II and Sb I were determined by emission spectroscopy of laser induced plasmas. the plasma was produced focusing the emission of a pulsed Nd-Yag laser on solid samples containing the atom in study. the light arising from the plasma region was collected by and spectrometer. the detector used was a time-resolved optical multichannel analyzer (OMA III EG and G). The wavelengths of the measured transitions range from 2000 sto 4100 A. The spectral resolution of the system was 0. 2 A. The method can be used in insulators materials as Cl Na crystals and in metallic samples as Al-Cr and Sn-Sn alloys. to avoid self-absorption effects the alloys were made with low Sb or Cr content. Relative transition probabilities have been determined from measurements of emission-line intensities and were placed on an absolute scale by using, where possible, accurate experimental lifetime values form the literature or theoretical data. From these measurements, values for plasma temperature (8000-24000 K), electron densities ({approx}{approx} 10''16 cm ''-3) and self-absorption coefficients have been obtained. (Author) 56 refs.

  3. Determinación de las condiciones experimentales óptimas de un acero AISI 4140 nitrurado por plasma postdescarga micro-ondas

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    Medina-Flores, A.

    2005-12-01

    Full Text Available AISI 4140 steel pieces were nitrided by an experimental reactor made in laboratory. A series of runs were to carry out to find the correct parameters below the point of transformation eutectoide (590 °C, which a compact, homogeneous and harder nitrided layer was formed on the top of the surface. Several characterizations techniques were used to analize the microsctructural change, such as, optical microscopy (OM, microhardness Vickers, X-Ray diffraction (DRX. The results showed the formation of a compact and homogeneous layer formed by a mixture of ε-Fe2,3N and γ’-Fe4N iron nitrides whit an average of 12 μm of thickness. The Vickers results showed a value of 1100 Hv on the top of the surface a concentration profile of microhardness is observed from the top of the surface to the core of the material.

    Piezas de acero AISI 4140 fueron nitruradas en un reactor experimental fabricado en el laboratorio. Para determinar los valores de los parámetros ideales de nitruración con los cuáles se obtuvo un mayor espesor, homogeneidad y dureza de la capa nitrurada, se llevaron a cabo una serie de experimentos, a temperaturas por debajo del punto de transformación eutectoide (590 °C. Para determinar el cambio microestructural de las muestras nitruradas, se analizaron, mediante diferentes técnicas de caracterización tales como microscopía óptica (MO, microdureza Vickers y difracción de rayos X (DRX. Los resultados mostraron la formación de una capa compacta y homogénea de 12 μm de espesor formada por los nitruros ε-Fe2,3N y γ’-Fe4N sobre la superficie del material. Los resultados de microdureza vickers mostraron un valor máximo de 1.100 Hv sobre la capa nitrurada observándose un perfil de microdureza de la superficie hacia el interior del material.

  4. Comportamiento a fatiga térmica de la capa de anclaje de nuevas barreras térmicas cerámicas obtenidas mediante proyección por plasma atmosférico

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    Pablo Carpio

    2016-05-01

    Full Text Available El desarrollo de nuevos materiales cerámicos para aplicarlos en recubrimientos protectores frente a la temperatura, también conocidos como barreras térmicas (Thermal Barrier Coatings o TBC, es de gran interés para muchos sectores, entre los que destacan las industrias de generación de energía, aeronáutica y automovilística.  En este trabajo se realizó un estudio del comportamiento a fatiga térmica, centrado en la respuesta de uno de los componentes que constituyen una TBC: la capa de anclaje. Los distintos componentes de la TBC fueron depositados mediante la técnica de proyección térmica por plasma atmosférico (Atmospheric Plasma Spraying o APS. Se estudió la microestructura y la composición de la capa de anclaje a lo largo de los ciclos térmicos de estudio.

  5. Relación entre los mecanismos de difusión atómica y las propiedades ópticas en la sinterización por Spark Plasma Sintering (SPS de la alúmina.

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    Torrecillas, R.

    2009-12-01

    Full Text Available The control of the sintering parameters during spark plasma sintering (SPS of polycrystalline alumina allows modifying the contribution due to the different atomic diffusion mechanisms. Thus, changing the heating rate as a function of the sintering stage allows tailoring sintering cycles that optimize the final density of the material with a minimal grain growth. It is shown in this work how by using two heating rates, 100 and 4ºC/min, allows obtaining a polycrystalline transparent alumina with a higher real in-line transmittance than that obtained with constant heating rates sintering cycles.

    El control de los parámetros de sinterización de la alúmina policristalina por spark plasma sintering (SPS permite modificar la contribución de los diferentes mecanismos de difusión atómica. Así, variar la rampa de calentamiento en función de la etapa de sinterización permite diseñar ciclos de sinterización que optimizan la densidad final del material con un mínimo crecimiento de grano. En este trabajo se demuestra cómo empleando dos velocidades, 100 y 4ºC/min, es posible obtener una alúmina policristalina con una transmitancia real en línea superior a la obtenida en ciclos con rampas constantes.

  6. In vitro study of the effects of radio frequency generated for plasma in neoplastic cells HT-29; Estudo in vitro dos efeitos da radiofrequencia gerada por plasmas em celulas neoplasicas HT-29

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    Andrighetto, Daniela; Dornelles, Eduardo Bortoluzzi; Cruz, Ivana Beatrice Manica da; Lüdke, Everton, E-mail: daniela.andrighetto@hotmail.com, E-mail: dornellesedu@gmail.com, E-mail: ibmcruz@hotmail.com, E-mail: evertonludke@gmail.com [Universidade Federal de Santa Maria (UFSM), RS (BRazil)

    2014-07-01

    The goal of this study is to develop an in vitro irradiation cell system with controllable irradiation intensities of 27 MHz produced by an argon plasma column with variable amplitude modulation in the 100-700 kHz range. This paper presents and discusses a proposed experiment, with toxicity analysis (DNA Picogreen®) and cell viability (MTT assay) in the radiation-induced HT-29 cell line (colon adenocarcinoma). The data allow us to observe that cellular toxicity effects may occur with exposure to fields produced by argon plasma with intensities on the order of at least 3.2 W / cm2 and exposure times above 3.5 hours continuously. An analysis of cell populations for cell toxicity tests using the Student's t-test did not show significant changes (p <0.05) in the amount of DNA released by the action of radiofrequency, although it has been found that cell viability (MTT) is not significantly altered by long exposures to radiation induced plasma RF signals in 27 MHz (p> 0.34). Cytotoxic effects due to the destruction of cell wall by heating the samples were not detected in any of the tests.

  7. Plasma density determination by microwave interferometry .- The 2 mm interferometer of the TJ-1 Tokamak; Determinacion de la densidad de un plasma por interferometria de microondas. El interferometro de 2 mm del Tokamak TJ-1

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    Martin, R; Manero, F

    1984-07-01

    In this paper a description is given of the microwave interferometer used for measuring the plasma electronic density in the TJ-1 Tokamak of Fusion Division of JEN. The principles of the electronic density measurement are discussed in detail, as well as those concerning the determination of density pro files from experimental data. A description of the interferometer used in the TJ-1 Tokamak is given, together with a detailed analysis of the circuits which constitute the measuring chain. The working principles of the klystron reflex and hybrid rings are also presented. (Author) 23 refs.

  8. Dureza e resistência ao desgaste da camada de ZrN formada por nitretação a plasma sobre zircônia parcialmente estabilizada com ítria Hardness and wear resistance of the ZrN layer made by plasma nitriding of yttria partially-stabilized zirconia

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    R. Milani

    2010-07-01

    Full Text Available Corpos-de-prova de zircônia parcialmente estabilizada com ítria foram moldados por prensagem uniaxial, sinterizados e nitretados em plasma de micro-ondas à pressão atmosférica. A camada de ZrN sobre zircônia formou-se a uma taxa de 4 µm.min-1, podendo atingir uma espessura de 500 µm. As amostras foram caracterizadas por meio de medidas de dureza e resistência ao desgaste. A superfície nitretada apresentou dureza superior e resistência ao desgaste similar ao substrato de zircônia.Samples of yttria partially-stabilized zirconia were molded by uniaxial pressing, sintered and nitrided in an atmospheric pressure microwave plasma. This procedure leads to the formation of a ZrN layer whose growth rate and thickness reached 4 µm.min-1 and 500 µm, respectively. The samples were characterized by means of hardness and wear resistance tests. The nitrided surface exhibits superior hardness and wear resistance similar to that of the zirconia substrate.

  9. Plasma Equilibrium in a Torus with High-Frequency Fields and Plasma Heating Resulting from the Development of a Powerful Beam of ''Escaping Electrons''; Plasma Torique: Stabilisation au Moyen de Champs de Haute Frequence et Chauffage par Formation d'un Flux Intense d'Electrons 'Emballes'; Ehksperimental'noe issledovanie ravnovesiya plazmy v tore pri nalichii vysokochastotnykh polej i nagreva plazmy za schet razvitiya moshchnogo puchka ''ubegayushchikh ehlektronov''; Equilibrio del Plasma en un Toro, en Presencia de Campos de Alta Frecuencia, y Calentamiento del Plasma por el Desarrollo de un Haz Potente de 'Electrones Desbocados '

    Energy Technology Data Exchange (ETDEWEB)

    Demirkhanov, R. A.; Kirov, A. G.; Stotland, M. A.; Malykh, N. I.; Horasanov, G. L.; Vishnevskij, N. K.; Gutkin, T. I.; Jampol' skij, I. R. [Fiziko-Tehnicheskij Institut Gosudarstvennogo Komiteta po Ispol' zovaniju Atomnoj Ehnergii SSSR, Sukhumi, SSSR (Russian Federation)

    1966-04-15

    par un courant d'intensite Ip compris entre 3 et 5 kA, lequel a un caractere essentiellement ohmique avec amortissement prononce. En meme temps, la tension dans le conducteur auxiliaire diminue; elle est aussi fortement amortie par rapport a celle qui correspond a la marche a vide, ce qui indique une absorption efficace de l'energie du circuit par le plasma. L'energie absorbee par le plasma au cours de la premiere periode du courant, c'est-a-dire pendant environ 1 {mu}s, represente environ 20 J; on constate d'ailleurs que la conductibilite du plasma est anormalement faible. Lors du chauffage au moyen d'un fort champ electrique, on observe une bouffee intense de rayons X dont l'energie est de l'ordre de 100 keV, ainsi qu'une emission de bruits a micro-ondes sur des frequences voisines de celle du plasma. (author) [Spanish] En la memoria se describen los experimentos realizados en la instalacion 'RT-0'. La instalacion tiene forma de toro, de 100 cm de diametro mayor y 10 cm de diametro menor. A lo largo de esta camara se genera un campo magnetico toroidal de unos 6 kOe. Se produce la ignicion del plasma a una presion P Greater-Than-Or-Equal-To 5 * 10{sup 4} Tony por medio de un campo electrico longitudinal rotacional (8,3 MHz). Hay un campo cuadrupolar de alta frecuencia (540 kHz) que gira alrededor del diametro menor, cuya intensidad es H{sub {phi}} = 200 Oe, junto a la pared de la camara. Al producirse la descarga de una bateria de condensadores de pequena induccion en las espiras situadas a lo largo del toro se puede generar, en el volumen de la camara, un campo electrico rotacional amortiguado, cuya intensidad maxima es E{sub z}=200 V/cm, con un semiperiodo de lus, aproximadamente. El objeto de los experimentos es: 1) estudio del equilibrio'y de la estabilizacion del plasma en un campo magnetico toroidal cuasi-constante, por medio de campos de alta frecuencia, multipolars y giratorios, suponiendo que la fuerza de deriva toroidal, Tilde-Operator (r/R)nkT, debe

  10. Ionic implantation by plasma in titanium and stainless steels used in prosthesis and medical instruments; Implantacion ionica por plasma en titanio y aceros inoxidables usados en protesis e instrumental medico

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    Munoz C, A. E. [ININ, 52750 La Marquesa, Estado de Mexico (Mexico)

    2008-07-01

    A study of a process known as plasma immersion ion implantation (PIII) of nitrogen at low voltages (< 4 kV) into three kind of samples: 1) austenitic stainless AISI 316-L steel plates, 2) ferritic stainless AISI 434 steel-based dentistry drills and 3) commercially pure titanium (CPTi) disks. On the case of CPTi the study was conducted in nitrogen- oxygen calibrated mixtures: 90% N-10% O, 80% N-20% O, 70% N-30% O and in 99.5% pure oxygen and 99.9% pure nitrogen. The PIII process was carried out by using a direct current plasma source controlled both in voltage and current, a negative voltage pulse modulator, a stainless AISI 304 steel vacuum chamber and a rod of the same material, horizontally located in the upper region of the chamber, which plays the role of anode in the plasma discharge. The purpose of the nitriding is forming a relatively thick layer on the surface of the steel specimens in order to enhance their both microhardness and general corrosion performances, desirable in medical applications. This layer contains interstitial nitrogen atoms ({approx}24% at.) which gives place to a deformed lattice (expanded phase) of the steel. Vickers microhardness and potentiodynamic tests (the latter in agreement to the norm ASTM G-61-89) confirm an increase of microhardness up to three times and a decrease of general corrosion rate in one order of magnitude. The nitriding of de dentistry drills is aimed at inhibiting the pitting corrosion produced by the asepsis process which results in pit nucleations, their propagation and consequent fractures when being under cyclic stress (fatigue). Scanning electron microscope micrographs reveal the risks involved in surpassing the critical treatment simple temperature of 450 C as the PIII process itself induces pitting. On its part, cyclic (ASTM G-61) potentiodynamic tests indicate an excellent pitting corrosion resistance of the samples treated under 450 C. In turn, the treatment of CPTi was meant to develop oxidized and

  11. Microestructura y oxidación cíclica en atmósferas con contenidos de oxígeno variables de un recubrimiento NiCrBSiFe proyectado térmicamente por plasma y HVOF

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    Higuera-Hidalgo, V.

    2006-12-01

    Full Text Available The influence of thermal spraying procedure (plasma and HVOF on the microstructure, high temperature oxidation resistance and adherence of NiCrBSiFe coatings has been examined. Two different series of oxidation tests have been carried out, in air (21% oxygen at 800 and 1,000 ºC (1,073 y 1,273 K and in a simulated gas turbine environment (10% oxygen representative of a combined-cycle power generation plant, at the same temperatures.
    Coating microstructure, porosity, oxide content and microhardness are highly dependent on the spraying procedure and coating hardness also significantly decreases after long maintenances at high temperature (1,000 ºC. Finally, the oxidation weight gain and the adherence of NiCrBSiFe coatings are also dependent on the morphology of the coating but, nevertheless, the oxidation behaviour of these coatings was very good as protective chromium and silicon oxides were always formed.

    Se ha llevado a cabo un estudio experimental sobre la influencia del proceso de proyección en la microestructura, resistencia a la oxidación y adherencia de los recubrimientos NiCrBSiFe proyectados térmicamente por plasma y llama a alta velocidad (HVOF, para lo que se han realizado ensayos en dos ambientes diferentes: en una atmósfera convencional (21 % de O2, a 800 y 1000 ºC (1.073 y 1.273 K, respectivamente, y en un ambiente simulativo de una turbina de gas y del generador de vapor de una central eléctrica de ciclo combinado (10-11 % de O2, a las mismas temperaturas. Se ha puesto de manifiesto que la microestructura, porosidad, contenido de óxidos y microdureza de estas capas varían significativamente con el sistema de proyección utilizado y que la microdureza de estas capas disminuye apreciablemente tras largos mantenimientos a alta temperatura (1.000 ºC. También, la ganancia de peso por oxidación de los recubrimientos NiCrBSiFe y la adherencia entre la capa y el sustrato dependen de la morfología del recubrimiento

  12. Análisis de plasmas inducidos por láser con excitación multipulso para el proceso de ablación de areolas de Tuna

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    Teresa Flores

    2010-01-01

    Full Text Available Introducción: La técnica de análisis de plasmas inducidos por láser (LIBS, posee importantes ventajas como son que la muestra no requiere preparación previa, puede estar en fase sólida, liquida o gaseosa y tener cualquier forma y dimensión, se requiere una cantidad mínima de material y, finalmente, el análisis se realiza en tiempo real. Estas ventajas, hacen posible el seguimiento en tiempo real de un proceso de ablación láser, incluso para muestras de composición compleja. Para el monitoreo de un proceso industrial, esta herramienta sería más adecuada, si se cuenta con una calibración del equipo y un protocolo particular definido. En el trabajo, se ejemplifica esta posibilidad para el caso de la ablación láser de areolas de Tuna (fruto de el Opuntia ficus-indica. Método: Se realiza el análisis LIBS de muestras de tuna, tanto en las areolas como en la corteza. Para la excitación del plasma se emplea un láser de Nd:YAG en régimen de Q:Switch con tren de pulsos. Con el objeto de asegurar el reconocimiento de las líneas en los espectros LIBS, se realizaron análisis en patrones de composición conocida, estableciéndose un protocolo para la interpretación de los espectros. Resultados: Se logró una clara lectura de la línea de H ubicada en 656.2 nm. Se estableció un protocolo para la interpretación de los espectros, que permitió la identificación de 49 picos característicos. Finalmente, se determina la composición para la corteza y la areola y se lleva a cabo una comparación cualitativa entre éstas. Discusión: Se muestra que la excitación láser en forma de tren de pulsos, entendido este régimen como modalidad particular del Q:Switch, permite la determinación eficiente de elementos, con una adecuada relación señal-ruido. Por otra parte, que es posible determinar diferencias composicionales evidentes entre corteza y la areola, lo cual permite monitorear un proceso de ablación de areolas con láser de manera

  13. Thin films of hydrogenated amorphous carbon (a-C:H) obtained through chemical vapor deposition assisted by plasma; Peliculas delgadas de carbono amorfo hidrogenado (a-C:H) obtenidas mediante deposito quimico de vapores asistido por plasma

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    Mejia H, J.A.; Camps C, E.E.; Escobar A, L.; Romero H, S.; Chirino O, S. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico); Muhl S, S. [IIM-UNAM, 04510 Mexico D.F. (Mexico)

    2004-07-01

    Films of hydrogenated amorphous carbon (a-C:H) were deposited using one source of microwave plasma with magnetic field (type ECR), using mixtures of H{sub 2}/CH{sub 4} in relationship of 80/20 and 95/05 as precursory gases, with work pressures of 4X10{sup -4} to 6x10{sup -4} Torr and an incident power of the discharge of microwaves with a constant value of 400 W. It was analyzed the influence among the properties of the films, as the deposit rate, the composition and the bonding types, and the deposit conditions, such as the flow rates of the precursory gases and the polarization voltage of the sample holders. (Author)

  14. Dez anos de experiência com a substituição da valva aórtica com homoenxertos valvares aórticos implantados pela técnica da substituição total da raiz Ten years experience of aortic valve replacement with aortic homograft root replacement

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    Francisco Costa

    2006-06-01

    Full Text Available OBJETIVO: Avaliar os resultados imediatos e tardios de 10 anos da substituição da valva aórtica por homoenxertos valvares aórticos implantados pela técnica de substituição total da raiz, e identificar eventuais fatores de risco correlacionados com a degeneração tecidual primária dos enxertos. MÉTODO: Entre maio/1995 e janeiro/2006, 282 pacientes com média de idade de 52,8±16,6 anos foram submetidos à substituição da valva aórtica com homoenxertos valvares. As etiologias prevalentes foram a valva aórtica bicúspide calcificada e a degeneração senil em 49% dos casos. Quarenta e sete pacientes eram reoperações e 26 tinham endocardite bacteriana aguda. Procedimentos associados foram realizados em 113 pacientes. O homoenxerto valvar foi implantado pela técnica de substituição total da raiz em todos os casos. O tempo de seguimento pós-operatório variou de 1 a 129 meses (média = 41±25 meses. RESULTADOS: A mortalidade imediata foi de 7%, sendo de apenas 2,6% nos casos de operação eletiva para a substituição isolada da valva aórtica. Dos 262 que receberam alta hospitalar, foi possível obter avaliação clínica e/ou ecocardiograma em 209 deles, sendo 51 (20% perdidos durante o seguimento. Houve 17 óbitos tardios, entre o 2º e 81º meses de pós-operatório, o que resultou em curva atuarial de sobrevida global de 90% e 80,1% aos 5 e 10 anos de evolução, respectivamente. Foram observados apenas oito episódios tromboembólicos (quatro imediatos e quatro tardios, durante a evolução para uma incidência linearizada de 0,3%/100 pacientes/ano. Endocardite bacteriana ocorreu em três ocasiões (0,4%/100 pacientes/ano. Nove pacientes foram reoperados, dos quais apenas três por problemas no homoenxerto (uma degeneração tecidual e dois casos de endocardite, o que resultou numa probabilidade de 94% livres dessa complicação aos 10 anos de seguimento. A análise do ecocardiograma tardio demonstrou gradiente m

  15. Efficacy and safety of argon plasma coagulation for the treatment of hemorrhagic radiation proctitis Eficacia y seguridad de la electrocoagulación con plasma de argón en el tratamiento del sangrado rectal secundario a proctitis por radioterapia

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    C. de la Serna Higuera

    2004-11-01

    to persist even after long-term follow-up.Objetivo: evaluar la eficacia, seguridad y curso evolutivo a medio/largo plazo de los pacientes tratados endoscópicamente con plasma de argón en nuestra unidad por sangrado rectal asociado a proctitis por radioterapia. Diseño: estudio descriptivo y retrospectivo a medio/largo plazo. Pacientes, material y métodos: entre julio de 1998 y febrero de 2003, se trataron con plasma de argón 10 pacientes que presentaron rectorragia secundaria a proctitis por radioterapia. Se consideraron criterios de inclusión la existencia de sangrado rectal crónico, presencia de hallazgos endoscópicos compatibles y ausencia de otras lesiones justificativas de sangrado. Se emplearon colonoscopios convencionales y equipo con fuente de gas argón y unidad quirúrgica de alta frecuencia. Se programaron sesiones consecutivas hasta conseguir la total eliminación de las lesiones rectales realizándose seguimiento clínico-evolutivo y valorando tolerancia, eficacia y potenciales complicaciones derivadas de la técnica. Se actualizaron los datos por entrevista personal o encuesta telefónica. Resultados: en todos los casos se consiguió la desaparición del sangrado después de la última sesión de tratamiento. El número medio de sesiones de tratamiento por paciente fue de 1,7. En cuatro casos fue precisa una única sesión. El tiempo medio de seguimiento tras concluir el tratamiento fue de 31,1, meses. En un caso recidivó el sangrado a los 4 meses, siendo precisas dos sesiones adicionales. Cuatro pacientes presentaban inicialmente signos analíticos de anemia que persistía sólo en un caso al final del estudio. No se registraron complicaciones tardías derivadas de la técnica, como úlceras o estenosis rectales. Conclusiones: la electrocoagulación endoscópica con plasma de argón supone en nuestra experiencia, una alternativa segura, eficaz y bien tolerada en el tratamiento del sangrado rectal asociado a la proctitis por radioterapia, con

  16. Influência da refusão por plasma na microestrutura de um revestimento Fe-Mn-Cr-Si depositado por aspersão térmica arco elétrico sobre aço inoxidável ASTM A743-CA6NM Influence of plasma remelting on the microstructure of Fe-Mn-Cr-Si arc thermal spray coating deposited on ASTM A743-CA6NM stainless steel

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    Anderson Geraldo Marenda Pukasiewicz

    2012-03-01

    Full Text Available ASTM A743-CA6NM é um aço inoxidável martensítico muito utilizado na fabricação de turbinas hidráulicas devido a sua elevada tenacidade, entretanto apresenta restrições com relação à regiões recuperadas por soldagem. Diferentes técnicas de deposição tem sido aplicadas com o intuito de reduzir ou eliminar a tensão residual. A deposição de revestimentos resistentes a cavitação é outra forma importante de aumentar a vida útil destes componentes. O objetivo deste trabalho é avaliar a influência do tipo e intensidade de corrente de refusão por plasma na microestrutura, composição química e microdureza de um revestimento Fe-Mn-Cr-Si resistente a cavitação depositado por aspersão térmica arco elétrico sobre aço ASTMA743-CA6NM. Observou-se que a adoção de menores valores de corrente média, assim como a utilização de corrente pulsada reduziram a formação de ferrita δ e a espessura final da ZTA, possibilitando a formação do revestimento com menores alterações na microestrutura do metal base. Verificou-se que a microestrutura e microdureza dos revestimentos refundidos não se mostraram muito sensível a variações na diluição do metal base. A utilização de corrente contínua promoveu um alinhamento da estrutura dendrítica no sentido da movimentação da tocha, entretanto este comportamento não foi observado em revestimentos refundidos com corrente pulsada.ASTM A743-CA6NM martensitic stainless steel have been used in hydraulic turbines manufacturing, but show some restrictions in welded recovered areas. Different techniques have been applied in order to reduce or eliminate residual stress, with life increase. The deposition of cavitation resistant coatings is another important way to increase the service life of these components. The objective of this study is evaluate the influence of type and intensity of plasma remelting current on the microstructure, chemical composition and microhardness of the Fe

  17. EFEITO DA INTENSIDADE DE DESRAMA NA PRODUÇÃO DE Pinus elliottii Engelm., IMPLANTADO EM SOLO POBRE, NO ESTADO DO RIO GRANDE DO SUL

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    Juarez Martins Hoppe

    1999-06-01

    Full Text Available No presente trabalho estudou-se a influência da intensidade de desrama sobre a produção de madeira de Pinus elliottii Engelm. em um experimento em blocos casualizados com três repetições e 5 tratamentos, definidos por: T1 - testemunha, sem desrama; T2 - desrama dos ramos seco; T3 - desrama de 40 % da altura total; T4 - desrama de 50 % da altura total; e T5 - desrama de 60 % da altura total das árvores. Observou-se que o diâmetro e a produção de madeira foram fortemente influenciados pela intensidade da desrama, aos 11 anos de idade. A testemunha com 263,5 m3/ha não diferiu do tratamento com desrama de ramos secos com 245,1 m3/ha, mas ambos diferiram dos tratamentos com desrama de 40 % da altura total com 231,5 m3/ha, da desrama de 50 % da altura total com 225,5 m3/ha, da desrama com 60 % da altura total com 211,6 m3/ha. A menor perda de produção foi de 12,1 % obtida no tratamento com desrama de 40 % da altura total, e a maior de 19,7 % ocorreu no tratamento de desrama com 60 % da altura total. Estes resultados permitem concluir pela recomendação da utilização de desrama com intensidade inferior a 40 % da altura total das árvores, pois permitem menores perdas de produção, ganhos em incremento diamétrico e na qualidade da madeira.

  18. Efeito da intensidade de desrama na produção de Pinus elliottii Engelm., implantado em solo pobre, no estado do Rio Grande do Sul.

    Directory of Open Access Journals (Sweden)

    Paulo Renato Schneider

    2009-09-01

    Full Text Available Normal 0 21 false false false MicrosoftInternetExplorer4 No presente trabalho estudou-se a influência da intensidade de desrama sobre a produção de madeira de Pinus elliottii Engelm. em um experimento em blocos  casualizados com três repetições e 5 tratamentos, definidos por: T1 - testemunha, sem desrama; T2 - desrama dos ramos seco; T3 - desrama de 40 % da altura total; T4 - desrama de 50 % da altura total; e T5 - desrama de 60 % da altura total das árvores. Observou-se que o diâmetro e a produção de madeira foram fortemente influenciados pela intensidade da desrama, aos 11 anos de idade. A testemunha com 263,5 m3/ha não diferiu do tratamento com desrama de ramos secos com 245,1 m3/ha, mas ambos diferiram dos tratamentos com desrama de 40 % da altura total com 231,5 m3/ha, da desrama de 50 % da altura total com 225,5 m3/ha, da desrama com 60 % da altura total com 211,6 m3/ha. A menor perda de produção foi de 12,1 % obtida no tratamento com desrama de 40 % da altura total, e a maior de 19,7 % ocorreu no tratamento de desrama com 60 % da altura total. Estes resultados permitem concluir pela recomendação da utilização de desrama com intensidade inferior a 40 % da altura total das árvores, pois permitem menores perdas de produção, ganhos em incremento diamétrico e na qualidade da madeira.

  19. Rastreamento de cardiopatias congênitas associadas ao diabetes mellitus por meio da concentração plasmática materna de frutosamina Congenital cardiopathies screening associated with diabetes mellitus using maternal fructosamine plasma concentration

    Directory of Open Access Journals (Sweden)

    Zilma Silveira Nogueira Reis

    2010-02-01

    Full Text Available OBJETIVO: avaliar a importância da concentração plasmática materna de frutosamina como indicador de cardiopatias congênitas fetais, em gestações complicadas pelo diabetes mellitus. MÉTODOS: o estudo retrospectivo incluiu 91 gestantes portadoras de diabetes mellitus, as quais foram submetidas à ecocardiografia fetal de rotina em centro universitário de referência em Medicina Fetal. Foram selecionadas 65 pacientes que apresentavam diabete pré-gestacional e registro em prontuário médico de frutosamina plasmática anterior ao exame ultrassonográfico. A primeira dosagem registrada foi confrontada com o resultado da ecocardiografia fetal de rotina, realizada por médico especialista do serviço. A presença ou ausência de achados ecográficos de cardiopatia congênita (AECC foi relacionada aos níveis plasmáticos de frutosamina, por meio de teste de médias, e sua acuidade para AECC verificada por curva ROC. Foram discutidos como pontos de corte os valores da concentração plasmática materna de frutosamina de 2,68, 2,9 e 2,23 mmol/L, que são, respectivamente, o valor de referência local do laboratório, o do kit de dosagem empregado e o de maior acurácia global. RESULTADOS: o AECC foi encontrado em 52,3% dos fetos. A primeira dosagem de frutosamina durante o pré-natal aconteceu em média com 20,4±8,0 semanas de gestação. A capacidade da concentração materna de frutosamina em identificar fetos com AECC foi significante (pPURPOSE: to evaluate the importance of maternal plasma concentration of fructosamine as an indicator of fetal congenital cardiopathies in pregnancies complicated by diabetes mellitus. METHODS: this was a retrospective study conducted on 91 pregnant women with diabetes mellitus who underwent routine fetal echocardiography at a university reference center in fetal medicine. Sixty-five patientes who presented pre-gestational diabetes mellitus and plasma fructosamine level were registered in the medical records

  20. Production of Al2O3–SiC nano-composites by spark plasma sintering; Producción de nano-composites – SiC–Al2O3 por spark plasma sinterizado

    Energy Technology Data Exchange (ETDEWEB)

    Mansour Razavi; Ali Reza Farajipour; Mohammad Zakeri; Mohammad Reza Rahimipour; Ali Reza Firouzbakht

    2017-11-01

    In this paper, Al2O3–SiC composites were produced by SPS at temperatures of 1600°C for 10min under vacuum atmosphere. For preparing samples, Al2O3 with the second phase including of micro and nano-sized SiC powder were milled for 5h. The milled powders were sintered in a SPS machine. After sintering process, phase studies, densification and mechanical properties of Al2O3–SiC composites were examined. Results showed that the specimens containing micro-sized SiC have an important effect on bulk density, hardness and strength. The highest relative density, hardness and strength were 99.7%, 324.6 HV and 2329MPa, respectively, in Al2O3–20wt% SiCmicro composite. Due to short time sintering, the growth was limited and grains still remained in nano-meter scale. [Spanish] En este trabajo se muestran compuestos de Al2O3-SiC producidos por SPS, en vacío, a 1.600 °C durante 10 min. Para la preparación de muestras, se molieron polvos de Al2O3 durante 5 h con la segunda fase de micro-y-nano polvo de SiC. Posteriormente, estos polvos molidos se sinterizaron mediante SPS. Después del proceso de sinterización, se realizaron estudios de fase, densificación y propiedades mecánicas de los compuestos de Al2O3-SiC obtenidos. Los resultados mostraron que micro-SiC en las muestras tiene un efecto importante en su densidad aparente, dureza y resistencia. La mayor densidad relativa, dureza y resistencia fueron respectivamente del 99,7%, 324,6 HV y 2.329 MPa para Al2O3 con un 20% en peso micro-SiC. Debido al corto tiempo de sinterización, el crecimiento los granos fue limitado y se mantuvieron en escala nanométrica.

  1. Turbulent Heating of Plasma by a Direct-Current Discharge; Chauffage Turbulent du Plasma par le Courant d'une Decharge Directe; ТУРБУЛЕНТНЫЙ НАГРЕВ ПЛАЗМЫ ТОКОМ ПРЯМОГО РАЗРЯДА; Calentamiento Turbulento del Plasma por una Corriente de Descarga Directa

    Energy Technology Data Exchange (ETDEWEB)

    Babykin, M. V.; Gavrin, P. P.; Zavojskij, E. K.; Rudakov, L. I.; Skorjupin, V. A. [Institut Atomnoj Ehnergii Im. I.V. Kurchatova, Moskva, SSSR (Russian Federation)

    1966-04-15

    concorde avec les autres mesures. Lorsque le plasma chauffe a une densite inferieure a 10{sup 13} cm{sup -3}, il se comprime de facon adiabatique en restant stable. Apres la compression, les electrons atteignent une temperature de 200 keV. Lorsqu'on augmente la densite initiale, la temperature consecutive au chauffage est plus faible et la compression ne peut s'operer. Les auteurs ont etudie le passage du signal, avec une frequence de 3.10{sup 8} Hz, a travers le plasma lorsque le courant est instable. Ils montrent que dans un plasma a forte turbulence, la couche ou se produit l'effet pelliculaire a une epaisseur superieure a c/ojp. Ils apportent une explication a ce phenomene. Le mecanisme du chauffage d'un plasma en presence d'un courant instable fait l'objet d'un examen critique. La theorie de c/{omega}{rho} phenomene est exposee en detail dans un memoire distinct. (author) [Spanish] En la memoria se exponen los resultados de los experimentos sobre el calentamiento turbulento del plasma una corriente de descarga directa en una trampa con espejos magneticos. Tambien se ha investigado la compresion adiabatica del plasma caliente y algunas propiedades del plasma turbulento. El campo magnetico llegaba hasta 9 kOe en 1,75 ms. Con campos de 0,5 a 9 kOe, se llenaba la trampa magnetica con plasma de deuterio, de densidad 10{sup 12} a 10{sup 13} cm{sup -3} mediante inyectores de titanio. Simultaneamente, entre los electrodos terminales se insertaba la capacidad de la descarga directa, con carga hasta de 10 a 30 kV, que en los distintos experimentos llegaba a 0,2, 0,8 y 2,65 uF. La descarga comenzaba en el momento del encuentro de los chorros de plasma. Al principio era aperiodica, con un crecimiento lento de la corriente, y en los oscilogramas se observaban oscilaciones que indicaban la inestabilidad de la corriente. La resistencia del plasma, determinada por su corriente y tension, es considerablemente mayor que la calculada segun el tiempo de las colisiones de Coulomb. Al

  2. Estudo dos mecanismos de limpeza por plasma

    OpenAIRE

    Mafra, Márcio

    2008-01-01

    Tese (doutorado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-Graduação em Ciência e Engenharia de Materiais. Na indústria metal-mecânica é frequente o emprego de tratamentos superficiais como forma de beneficiamento de peças e componentes mecânicos cujas solicitações estejam relacionadas com a superfície. A realização de tratamentos termoquímicos, a aplicação de filmes e mesmo a pintura podem ser comprometidas se contaminantes orgânicos estiverem presentes...

  3. Estudio comparativo de técnicas de preparación de muestras para microscopía electrónica de transmisión de recubrimientos cerámicos proyectados por plasma

    Directory of Open Access Journals (Sweden)

    Ramírez de Arellano López, A.

    2000-12-01

    Full Text Available The development of advanced materials, with complex microstructures, is a permanent challenge to the development and application of new efficient techniques for microstructural characterization. In ceramic coatings on metals, there exist a differential ion-milling ratio between both components, limiting in principle the use of conventional techniques. In this work, we report on a comparative study of TEM sample preparation techniques for plasma-sprayed ceramic coatings. Firstly, we have used a procedure derived from the conventional one (polishing, dimpling, ion milling, and alternatively a new technique using focused ion-beam milling. The material selected for this study is fine-grained alumina that was plasmasprayed on a steel substrate. The efficiency of both techniques is discussed along with the most significant microstructural features of the material subject of study.

    El desarrollo de materiales avanzados, con microestructuras cada vez más complejas, supone un reto constante de desarrollo y aplicación de técnicas que permitan el análisis de la microestructura de forma eficiente. En el caso de los recubrimientos cerámicos sobre substrato metálico, la diferente velocidad de adelgazamiento iónico que suelen mostrar ambos sistemas supone, en principio, una limitación sustancial. En este trabajo, presentamos un estudio comparativo de la fabricación de láminas delgadas para microscopía electrónica de transmisión, empleando en primer lugar una técnica derivada de la convencional (desbaste, pulido y adelgazamiento iónico, y alternativamente una novedosa técnica de ataque selectivo mediante un haz iónico. El material elegido para realizar este estudio ha sido un recubrimiento de óxido de aluminio de grano fino proyectado por el método de plasma sobre acero. Se discute la eficiencia de cada una de las técnicas, así como las carácteristicas microstructurales más destacadas en el material objeto de estudio.

  4. Determinação de cetamina em plasma por HPLC: aplicação em um estudo de farmacocinética de associação medicamentosa em cães

    Directory of Open Access Journals (Sweden)

    R. AMORIM

    2009-01-01

    Full Text Available

    A S(+ cetamina é um fármaco amplamente utilizado na medicina para induzir anestesia e a associação com midazolam é empregada para minimizar seus efeitos adversos. Associações medicamentosas podem resultar em interações farmacocinéticas e a disponibilidade de métodos bioanalíticos para a determinação da cetamina em plasma constitui ferramenta útil para a avaliação do perfil cinético do fármaco administrado isoladamente ou em associação. O presente estudo teve como objetivo o desenvolvimento e validação de um método analítico para determinação da cetamina em plasma por cromatografia líquida de alta eficiência (HPLC e a investigação do perfil farmacocinético da cetamina em quatro cães hígidos da raça Beagle. A S(+ cetamina (10mg/kg foi administrada pela veia cefálica em dose única isoladamente (protocolo I ou associada ao midazolam (0.2mg/kg (protocolo II em estudo cruzado com intervalo de uma semana para washout. Amostras seriadas de sangue foram coletadas no intervalo de oito horas e analisadas por HPLC para a avaliação do perfil farmacocinético utilizando modelo bicompartimental. O método bioanalítico apresentou limites de confiança aceitáveis para sua aplicação em estudos de farmacocinética e os parâmetros área sob a curva (ASC0-8, volume de distribuição (Vd, clearance total (Clt, meia vida de eliminação (t/12 ß, constante de eliminação (ß, meia vida de distribuição (t1/2α e constante de distribuição (α não mostraram diferenças estatísticas significativas entre os grupos (p < 0.05, Wilcoxon. Os resultados obtidos sugerem que a redução dos efeitos colaterais da cetamina decorrente do uso da associação cetamina-midazolam não está relacionada a alterações no perfil farmacocinético da cetamina. Palavras-chave: cetamina; farmacocin

  5. Effect of microstructure and microhardness on the wear resistance of zirconia-alumina, zirconia-yttria and zirconia-ceria coatings manufactured by atmospheric plasma spraying; fecto de la microestructura y de la microdureza sobre la resistencia al desgaste de recubrimientos elaborados por proyeccion termica por plasma atmosferico a partir de circona-alumina, circona-itria y circona-ceria

    Energy Technology Data Exchange (ETDEWEB)

    Giovanni Gonzalez, A.; Ageorges, H.; Rojas, O.; Lopez, E.; Milena Hurtado, F.; Vargas, F.

    2015-10-01

    The effect of the structure and microhardness on the wear resistance of zirconia-alumina (ATZ), zirconia-yttria (YSZ) and zirconia-ceria (CSZ) coatings manufactured by atmospheric plasma spraying was studied. The microstructure and the fracture on the cross section of the coatings were analyzed using Scanning Electron Microscopy, the phases were identified using X-Ray Diffraction, the microhardness was measured by Vickers indentation and the wear resistance was evaluated by ball on disc test. The results showed that zirconia-alumina coating exhibits the best performance in the wear test. This behavior is closely related to their microstructure and higher microhardness, despite of its significant quantity of the monoclinic zirconia phase, which has lower mechanical properties than tetragonal zirconia phase. Tetragonal zirconia phase was predominant in the zirconia-yttria and zirconia-ceria coatings and despite this behavior; they did not have a good performance in the wear tests. This low wear resistance was mainly influenced by the columnar structure within their lamellae, which caused a greater detachment of particles in the contact surface during the ball-disc tests, increasing its wear. (Author)

  6. Avaliação do estado nutricional de seringais implantados na região da Zona da Mata de Minas Gerais Nutritional evaluation of rubber tree plantations at Zona da Mata region, Minas Gerais State, Brazil

    Directory of Open Access Journals (Sweden)

    Ciríaca Arcangela Ferreira de Santana do Carmo

    2002-10-01

    Full Text Available O objetivo deste trabalho foi avaliar o estado nutricional de seringais implantados na Zona da Mata, em Minas Gerais, visando contribuir com um programa racional de adubações. Em seringais do clone IAN 873 foram determinadas a classe do solo, fertilidade, nutrição e produção de borracha seca. Grande parte dos seringais encontra-se em Latossolos extremamente ácidos com Al alto e N, P, K, soma de bases trocáveis e capacidade de troca de cátions baixos. Os teores de Ca e Mg variaram de médios a altos nos Latossolos e foram muito altos nos Nitossolos, correlacionando-se negativamente com a produção de borracha seca. A análise foliar detectou desequilíbrios nutricionais no que se refere aos baixos teores de N e K evidenciados pela correlação positiva significativa com a produção de borracha seca. A correlação significativa negativa entre a produção de borracha seca e os teores de Ca foliares, associados aos altos teores de Mg, sugerem a redução desses nutrientes nas adubações. Dos micronutrientes, apenas o Cu apresentou correlação positiva e significativa com a produção de borracha seca.The objective of this work was to evaluate the nutritional status of rubber tree plantations at Zona da Mata region, Minas Gerais State, Brazil, to contribute with fertilization programs. Soil class, fertility levels, nutritional state and production of dry rubber were determined in rubber plantations of the clone IAN 873. Most plantations occur over extremely acid Oxisols with high contents of Al and low values of N, P, K, sum of exchangeable basis and cation exchange capacity. Calcium and Mg contents varied from medium to high and showed negative correlation with dry rubber production. Plant analysis showed unbalanced contents of N and K with low values but positive and significant correlation with dry rubber production. Significant and negative correlation between dry rubber production and Ca contents, associated to high contents of Mg

  7. Complementação por coagulação com plasma de argônio após a ressecção endoscópica completa pela técnica de fatiamento para grandes adenomas colorretais

    Directory of Open Access Journals (Sweden)

    Walton Albuquerque

    Full Text Available OBJETIVO: avaliar a eficácia da complementação por coagulação com plasma de argônio para reduzir a taxa de neoplasia residual ou recorrente após ressecção endoscópica completa fragmentada de grandes adenomas sésseis colorretais. MÉTODOS: critérios de inclusão: pacientes com grandes adenomas colorretais sésseis, > 20mm, sem sinais morfológicos de infiltração profunda, submetidos à ressecção endoscópica completa fragmentada estudada com cromoendoscopia e magnificação de imagens. Os pacientes foram randomizados em dois grupos: grupo 1 - nenhum procedimento adicional e, grupo 2 - complementação por coagulação com plasma de argônio. O seguimento por colonoscopia foi realizado em três, seis e 12 meses de pós-operatório. Foi avaliada a taxa de neoplasia residual ou recidiva local. RESULTADOS: foram incluídos no estudo um total de 21 lesões. Onze lesões no grupo 1 e dez no grupo 2. Ocorreram duas neoplasias residuais ou recorrências locais em cada grupo, detectadas em três meses de acompanhamento. CONCLUSÃO: a complementação por coagulação com plasma de argônio após uma aparente ressecção endoscópica completa em fragmentos de grandes adenomas sésseis colorretais não parece reduzir a ocorrência de lesão adenomatosa residual ou recidiva local.

  8. Atributos químicos do solo decorrentes da aplicação em superfície de calcário e gesso em sistema plantio direto recém-implantado Chemical soil attributes as affected by lime and phosphogypsum surface application in a recently established no-tillage system

    Directory of Open Access Journals (Sweden)

    Rogério Peres Soratto

    2008-04-01

    Full Text Available Há interesse em implantar o sistema plantio direto em áreas anteriormente cultivadas no sistema convencional ou sob pastagem, corrigindo a acidez com calagem superficial após a implantação do sistema. Essa prática pode ser possível desde que não haja impedimento físico do solo ao crescimento radicular. Nesse sentido, o gesso é uma alternativa para diminuição da atividade do Al3+ e aumento da saturação por bases (V, principalmente Ca2+, nas camadas do subsolo, podendo ser utilizado como produto complementar ao calcário. Este trabalho objetivou avaliar as alterações dos atributos químicos do solo (pH CaCl2, H + Al, Al3+, Ca2+, Mg2+, S-SO4(2-, V e teor de micronutrientes catiônicos decorrentes da aplicação de calcário e de gesso agrícola em superfície em sistema plantio direto recém-implantado em região de inverno seco. O experimento foi conduzido em um Latossolo Vermelho distroférrico de Botucatu (SP. O delineamento experimental foi em blocos casualizados com parcelas subdivididas e quatro repetições. As parcelas foram constituídas por quatro doses de calcário dolomítico com PRNT de 71,2 % (0, 1.100, 2.700 e 4.300 kg ha-1, visando elevar a saturação por bases a 50, 70 e 90 %, respectivamente. As subparcelas foram constituídas pelas doses de gesso agrícola de 0 e 2.100 kg ha-1. Amostras de terra foram coletadas nas profundidades de 0-0,05, 0,05-0,10, 0,10-0,20, 0,20-0,40, 0,40-0,60 e 0-0,20 m, aos três, seis, 12 e 18 meses da aplicação dos produtos. A aplicação superficial de calcário diminuiu a acidez e elevou os teores de Ca e Mg trocável, principalmente nas camadas superficiais do solo. A aplicação de gesso agrícola aumentou os teores de Ca trocável e S-SO4(2-, e diminuiu os teores de Al no solo, contribuindo para que os efeitos da calagem superficial nas características químicas do solo alcançassem, de forma mais rápida, as camadas do subsolo. Os valores de saturação por bases obtidos na

  9. Nitretação por plasma em baixa temperatura dos aços inoxidáveis martensíticos : estudo da influência da composição química do aço na cinética de tratamento

    OpenAIRE

    Ferreira, Lauro Mariano

    2015-01-01

    Orientador: Prof. Dr. Rodrigo Perito Cardoso Co-orientador: Prof. Dr. Silvio Francisco Brunatto Dissertação (mestrado) - Universidade Federal do Paraná, Setor de Tecnologia, Programa de Pós-Graduação em Engenharia e Ciência dos Materiais - PIPE. Defesa: Curitiba, 13/04/2015 Inclui referências : f. 86-90 Área de concentração: Engenharia e ciência de materiais Resumo: A crescente aplicação dos tratamentos termoquímicos assistidos por plasma no âmbito industrial motivou o desenvol...

  10. Celulitis por citomegalovirus

    Directory of Open Access Journals (Sweden)

    A. Ruiz Lascano

    2002-12-01

    Full Text Available Las lesiones cutáneas por citomegalovirus (CMV son infrecuentes y a menudo una manifestación tardía de una enfermedad sistémica, que generalmente anuncia un curso fatal. Comunicamos un caso de celulitis por CMV: una mujer de 70 años con trasplante renal efectuado 1 mes antes de la consulta, terapia inmunosupresora con ciclosporina A y metilprednisona. La paciente ingresó por fiebre, dolor e impotencia funcional en pierna derecha. Comprobamos la existencia de una placa de 8 por 4 cm eritematoedematosa. La tratamos con antibióticos sin mejoría, por lo que realizamos un estudio histopatológico de piel que mostró cambios citopáticos compatibles con infección por CMV. Los cultivos bacteriológicos y micológicos fueron negativos. La inmunohistoquímica específica para CMV y el estudio de reacción en cadena de la polimerasa (PCR de la biopsia de piel fueron positivas, al igual que la antigenemia. El tratamiento con ganciclovir produjo la mejoría del cuadro clínico. En la literatura revisada no hemos encontrado la celulitis como manifestación de enfermedad cutánea por CMV.

  11. Determinação rápida de fármacos básicos em plasma por cromatografia a gás com detector de nitrogênio e fósforo

    Directory of Open Access Journals (Sweden)

    Lilian Feltraco Lizot

    2012-01-01

    Full Text Available A simple and fast method for determination of 40 basic drugs in human plasma employing gas-chromatography with nitrogen-phosphorus detection was developed and validated. Drugs were extracted from 800 µL of plasma with 250 µL of butyl acetate at basic pH. Aliquots of the organic extract were directly injected on a column with methylsilicone stationary phase. Total chromatographic run time was 25 min. All compounds were detected in concentrations ranging from therapeutic to toxic levels, with intermediate precision CV% below 11.2 and accuracy in the range of 92-114%.

  12. Action of tacrolimus on Wistar rat kidneys implanted with Walker 256 carcinosarcoma Estudo da ação do tacrolimus em rins de ratos Wistar implantados com carcinossarcoma de Walker

    Directory of Open Access Journals (Sweden)

    Cristiano Machado Inácio

    2010-02-01

    as alterações na evolução do carcinosarcoma 256 de Walker, inoculado no rim de ratos Wistar, sob tratamento imunossupressor com o tacrolimus. MÉTODOS: Foram utilizados 40 ratos Wistar, machos divididos em quatro grupos de 10: grupo Tumor (TU, Tumor-Tacrolimus (TT, Tacrolimus (TC e Controle (C. Os ratos dos grupos TU e TT foram inoculados com 0,1 mL de solução contendo 2x10(6 células do tumor de Walker no parênquima do rim direito. Os dos grupos TC e TT receberam tratamento com tacrolimus na dose de 5mg/kg de peso, via gavagem orogástrica durante 15 dias. Os ratos do grupo TU receberam solução salina isotônica pH 7,2. Ao 15º dia de evolução, todos foram submetidos à eutanásia. Amostras de sangue eram coletadas para dosagem de creatinina (Cr e uréia (Ur e posteriormente realizada nefrectomia para avaliação histológica. RESULTADOS: As dosagens séricas de creatinina foram maiores no grupo TT (Cr = 1,013±0,3028 mg/mL, que diferiu significantemente dos grupos TU (Cr=0,5670 ± 0,03536 mg/dL com p=0,00256 e do TC (Cr=0,711 ± 0,1653 mg/mL com p=0,02832. As dosagens séricas de uréia foram maiores no grupo TT (71,32 ± 17,14 mg/mL, que diferiu significantemente do grupo TU (45,83 ± 5,046mg/dL com p=0,000318, mas comparado ao grupo TC (61,23 ± 9,503 mg/mL não houve diferença significante (p=0,7242. No inventário da cavidade abdominal dos grupos TU e TT, observou-se presença macroscópica de tumor em todos os rins direitos; não foram evidenciadas efusões ascíticas, formação de bridas ou metástases tumorais em outros órgãos ou tecidos adjacentes aos rins direitos. CONCLUSÃO: O tacrolimus exerceu efeito nefrotóxico e induziu exacerbação do crescimento do tumor de Walker 256, quando implantado no rim de ratos Wistar.

  13. por láser

    Directory of Open Access Journals (Sweden)

    Mayra Garcimuño

    2013-01-01

    Full Text Available En el presente trabajo, la técnica Espectroscopia de plasmas producidos por láser (Laser-induced breakdown spectroscopy –LIBS– se aplicó a la determinación cuan- titativa de Na en agua natural dulce, de interés en agricultura para el estudio de la alcalinidad de aguas de regadío. Para efectuar el análisis, se prepararon soluciones con concentraciones conocidas del analito, se mezclaron con óxido de calcio y se compactaron en pastillas sólidas. Los plasmas se produjeron en aire a presión atmos- férica utilizando un láser pulsado Nd:YAG. Se construyó una curva de calibración y se calculó el límite de detección. Se analizaron muestras de agua natural y los resultados se compararon con los obtenidos mediante espectroscopia de absorción atómica. Se demostró la factibilidad del método para la determinación de Na en agua natural dulce.

  14. Método analítico por cromatografía líquida de alta resolución para la determinación de carbamazepina en plasma humano Analytical method by high resolution liquid chromatography for the determination of carbamazepine in human plasma

    Directory of Open Access Journals (Sweden)

    Narda M. Jiménez Alemán

    2007-04-01

    Full Text Available Entre los requisitos para desarrollar los estudios de biodisponibilidad y bioequivalencia se encuentra contar con metodologías analíticas validadas para el trabajo con muestras en fluidos biológicos. Se desarrolló un método por cromatografía líquida de alta resolución para la determinación de carbamazepina en plasma humano, se utilizó como fase móvil una mezcla de hidrógeno fosfato de sodio: acetonitrilo (65:35 ajustada a pH= 3,3 con ácido fosfórico, flujo de 1,2 mL/min y detección ultravioleta a 210 nm. Se empleó propilparabeno como estándar interno. Conforme con las regulaciones establecidas para la validación de métodos en fluidos biológicos se estudiaron los parámetros siguientes: estabilidad de las muestras, linealidad, especificidad, precisión, exactitud y límite de detección y cuantificación. El método resultó específico y sensible con un límite de detección y cuantificación de 0,9 y 1,0 ng, respectivamente. El método fue lineal, preciso y exacto en el rango de concentraciones de 1,07 a 12,67 µg/mL. La recuperación media no fue estadísticamente diferente del 100,0 %. El analito en la matriz biológica propuesta permaneció en el periodo estudiado. La metodología descrita en este trabajo se aplica en nuestro caso al estudio que evalúa la biodisponibilidad y bioequivalencia de una formulación cubana de carbamazepina en voluntarios sanos.One of the requirements to develop the studies of bioavailability and bioequivalence is to have analytic methodologies validated for the work with samples in biological fluids. A method was developed by high resolution liquid chromatography for the determination of carbamazepine in human plasma. A mixture of hydrogen phosphate of sodium: acetonitrile (65:35 adjusted to pH= 3.3 with phosphoric acid, flow of 1.2 mL/min and ultraviolet detection at 210 nm, was used as mobile phase. Propylparabene was used as an internal standard. According to the established regulations for

  15. Argon plasma coagulation and hyperbaric oxygen therapy in chronic radiation proctopathy, effectiveness and impact on tissue toxicity Argón plasma y oxígeno hiperbárico para el control de la rectorragia crónica secundaria a la proctopatía por radiación

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    Julio César Álvaro-Villegas

    2011-11-01

    Full Text Available Background: chronic radiation proctopathy (CRP is associated with recurrent rectal bleeding and transfusional requirements. Argon plasma coagulation (APC and hyperbaric oxygen therapy (HOT have been shown to be effective in the control of CRP. No prospective comparisons have been reported between these treatments. Aim: the aim was to evaluate the effectiveness, safety and impact on tissue toxicity of APC compared to HOT in patients with CRP. Material and methods: a prospective study for evaluating treatment response was conducted. Patients with cervical cancer and CRP with rectal bleeding were recruited. They had not received previous treatment. Collected data included: demographics, previous radiation dosage, duration and severity of rectal bleeding. Hemoglobin, transfusional requirements, and tissue toxicity (SOMA LENT questionnaire at baseline and at 1, 2, and 3 months follow up were recorded. Results: thirty-one patients were included, 14 in the APC group and 17 in the HOT group. No response was noted in 13 and 18% of patients in the APC and HOT group respectively (p = NS. At the 1 and 2 months follow-up, the APC group showed a significantly better response in terms of transfusional requirements (0.6 vs. 3.4 and 0.7 vs. 2.5 and tissue toxicity score (5.3 vs. 8.6 and 3.8 vs. 7.248. After 3 months, both groups showed further improvement in all parameters without significant differences between them. Conclusions: APC and HOT were effective, safe and decreased the tissue toxicity scores in patients with CRP. However, response rate was higher and faster in the APC group.Introducción: la proctopatía por radiación (PPR se asocia con rectorragía recurrente y requerimientos de trasfusiones. La coagulación con argón plasma (APC y la terapia con oxígeno hiperbárico (HOT han sido efectivas en el control de la PPR. No hay estudios prospectivos comparativos entre ambas técnicas. Objetivo: el objetivo del estudio es evaluar la efectividad

  16. Caracterización de un plasma pulsado utilizado para producir recubrimientos de TiN, por medio de espectroscopía óptica de emisión

    OpenAIRE

    Restrepo Parra, Elisabeth

    2001-01-01

    En este trabajo se realiza la caracterización de un plasma pulsado utilizado para la producción de recubrimientos duros de TiN, utilizando técnicas de espectroscopía óptica de emisión. Con el fin de realizar esta caracterización se han calculado la temperatura y la densidad electrónica de dicho plasma. El cálculo de la temperatura electrónica se realiza suponiendo que esta es diferente de la temperatura de excitación de los átomos, esto nos permite modificar el método más convencional, co...

  17. Electrocardiografo por computadora

    OpenAIRE

    Tinoco Hernandez, Rosanna; Paredes Bejarano, Margarita; Romero Chaglia, Norman; Yapur Auad, Miguel Eduardo

    2009-01-01

    El presente trabajo trata sobrees el diseño y la implementación de un graficador de señales cardiacas por computadora, para lo cual diseñamos un circuito electrónico capaz de recibir la senal analógica proveniente de la actividad electrica del corazón , amplificarla, y luego convertirla en una señal digital para ser procesada por software y finalmente ser graficada, siendo posible así observar la señal cardiaca en el monitor de un computador como un tren de pulsos. Cabe destacar que par...

  18. UMA ABORDAGEM SOBRE A GESTÃO DE PESSOAS POR COMPETÊNCIA EM UMA INSTITUIÇÃO FINANCEIRA

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    Bernadeth Mouta Cardozo Colares

    2013-01-01

    Full Text Available Este artigo apresenta uma forma de gerir pessoas que está sendo utilizada por grandes organizações, que passam a valorizar cada vez mais o capital humano - suas competências e o quanto estas contribuem para agregar valor à organização. Com o uso de ferramentas inovadoras e eficazes, busca-se promover o crescimento e o desenvolvimento profissional e individual das pessoas, para que as organizações se mantenham atuando em um ambiente de negócios cada vez mais competitivo. É imprescindível que se explore o potencial humano para que as empresas tenham uma atuação mais eficaz em seus devidos mercados, gerando diferenciais entre seus concorrentes. O presente estudo foi feito através de pesquisas bibliográficas, tendo como fontes livros e sites da internet, de onde foram obtidas as informações necessárias para a elaboração desse artigo. Foram levantados dados de uma instituição financeira que utiliza o modelo de Gestão de Pessoas por Competências. Com as respostas obtidas através de um questionário direcionado ao setor de desenvolvimento humano da empresa, foram descritos neste artigo dados com o intuito de mostrar como foi implantado tal modelo de gestão, as etapas que foram utilizadas pela empresa, suas vantagens e seus benefícios.

  19. Indice por Materias

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    Montoya H Luz Marina

    1982-09-01

    Full Text Available Un índice es una lista de palabras o frases indicadores asociados que permite la ubicación de material al interior de un libro o una publicación, en este caso será por el nombre de la materia.

  20. Uso del agua y productividad de los bosques nativos e implantados en el NO de la Patagonia: aproximaciones desde la ecohidrología y la ecofisiología

    OpenAIRE

    Gyenge, Javier E; Fernández, M Elena; Licata, Julián; Weigandt, Mariana; Bond, Barbara J; Schlichter, Tomás M

    2011-01-01

    Existe preocupación por el posible uso excesivo de agua de las forestaciones con especies exóticas de rápido crecimiento en comparación con las especies nativas a las cuales reemplazan en la región NO de la Patagonia. Debido a ello, se han realizado estudios de productividad, consumo y eficiencia en el uso del agua tanto en plantaciones de especies exóticas como en sistemas vegetales naturales en zonas con distintos niveles de déficit hídrico. Esto se llevó a cabo mediante aproximaciones ecoh...

  1. Víctimas de accidentes de tránsito. Su protección en el mundo a través del aseguramiento obligatorio y breve referencia al sistema implantado en Colombia

    OpenAIRE

    Navas Herrera, María Fernanda; Pontificia Universidad Javeriana

    2009-01-01

    El presente artículo traduce en breves comentarios, una amplia muestra estadísticade los diversos sistemas de aseguramiento de las víctimas en accidentes detránsito en diferentes países del mundo. Basándose en una recopilación de datosrealizada por la Asociación Internacional de Derecho de Seguros (AIDA) durantelos últimos 10 años a nivel mundial, este escrito muestra las diferentes coberturasdel seguro obligatorio de responsabilidad civil de automóviles, las tarifas, loslímites de indemnizac...

  2. Study of carbonitriding thermochemical treatment by plasma screen in active with pressures main austenitic stainless steels AISI 409 and AISI 316L; Estudo do tratamento termoquimico de carbonitretacao por plasma em tela ativa com pressoes variaveis nos acos inoxidaveis austenitico AISI 316L e ferririco AISI 409

    Energy Technology Data Exchange (ETDEWEB)

    Melo, M.S.; Oliveira, A.M.; Leal, V.S.; Sousa, R.R.M. de; Alves Junior, C. [Centro Federal de Educacao Tecnologica do Maranhao (CEFET/MA), Sao Luis, MA (Brazil); Centro Federal de Educacao Tecnologica do Piaui (CEFET/PI), Teresina, PI (Brazil); Universidade Federal do Rio Grande do Norte (DF/UFRN), Natal, RN (Brazil). Dept. de Fisica. Labplasma

    2010-07-01

    The technique called Active Screen Plasma Nitriding (ASPN) is being used as an alternative once it offers several advantages with respect to conventional DC plasma. In this method, the plasma does not form directly in the sample's surface but on a screen, in such a way that undesired effects such as the edge effect is minimized. Stainless steels present not very satisfactory wearing characteristics. However, plasma carbonitriding has been used as to improve its resistance to wearing due to the formation of a fine surface layer with good properties. In this work, samples of stainless steel AISI 316L and AISI 409 were treated at pressures of 2.5 and 5 mbar. After the treatments they were characterized by microhardness, microscopy and Xray diffraction. Microscopy and hardness analysis showed satisfactory layers and toughness in those steels. (author)

  3. Relationship between plasma and red blood cell concentrations of quinine in Brazilian children with uncomplicated Plasmodium falciparummalaria on oral therapy Relação entre as concentrações plasmáticas e eritrocitárias de quinina em crianças com malária por Plasmodium falciparum não complicada em terapia via oral

    Directory of Open Access Journals (Sweden)

    José L.F. Vieira

    2009-04-01

    Full Text Available We determined the relationship between plasma and red blood cell concentrations of quinine in children with uncomplicated falciparum malaria from an endemic area of Amazonian region. Quinine was determined by high performance liquid chromatography with ultraviolet detection. In the steady state the ratio between plasma and red blood cell quinine concentration was 1.89 ± 1.25 ranging from 1.05 to 2.34. This result demonstrated that quinine do not concentrate in red blood cell of Brazilian children and characterize the absence of interracial difference in this relationship.Neste estudo foi determinada a relação entre as concentrações plasmáticas e eritrocitárias de quinina em crianças com malária falciparum não complicada, oriundas de área endêmica da Região Amazônica. A quinina foi detrminada por cromatografia líquida de alta eficiência. No estado de equilíbrio, a relação foi 1,89 ± 1,25 variando de 1,05 a 2,34. Estes resultados demonstraram que a quinina não se concentra nos eritrócitos das crianças e caracterizaram a ausência de diferença racial nesta relação.

  4. Apendicitis por Paracoccidioides brasiliensis

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    Ana Beatriz MUÑOZ URRIBARRI

    2006-01-01

    Full Text Available La paracoccidioidomicosis es la micosis más prevalente en Sudamérica. La forma aguda afecta el sistema fagocítico mononuclear de niños y personas inmunocomprometidas. El compromiso gastrointestinal es frecuente y su patogenia implica diseminación hematógena y linfática. La linfadenomegalia abdominal causa obstrucción intestinal y abdomen agudo. En este artículo damos a conocer el caso de un niño con compromiso gastrointestinal por apendicitis. Este es el primer caso reportado de apendicitis por esta patología. (Rev Med Hered 2006;17:58-60.

  5. Produção de concentrados de frutose por inulinases de Penicillium janczewskii e atividade sobre o nível de glicose plasmática em ratos diabéticos Fructose syrups produced by inulinases from Penicillium janczewskii and activity on plasma glucose level in diabetic rats

    Directory of Open Access Journals (Sweden)

    Rosemeire A. Bom Pessoni

    2004-09-01

    Full Text Available A frutose é utilizada atualmente como adoçante para diabéticos, sendo produzida comercialmente por hidrólise do amido, sob um processo de alto custo que envolve três etapas enzimáticas usando alfa-amilase, amiloglicosidase e glicose isomerase. Uma alternativa para a produção de concentrados de frutose é a hidrólise enzimática da inulina, polímero de frutose encontrado em Asteráceas, incluindo espécies nativas do cerrado. Nesse caso, através de uma única etapa enzimática obtêm-se concentrados com até 95% de frutose. Embora baixos níveis desse açúcar possam ser metabolizados na ausência de insulina, seu efeito sobre a redução do nível de glicose plasmática ainda não está completamente esclarecido. No presente trabalho foi avaliada a ação da frutose produzida por hidrólise da inulina de Vernonia herbacea (Asteraceae por inulinases de Penicillium janczewskii no nível de glicose plasmática de ratos diabéticos. Dentre os animais diabéticos tratados não foi verificada mortalidade, havendo redução de 46% em média (pFructose has been used as sweetener by patients with diabetes. This sugar is usually produced from starch by a high-cost enzymatic process, which envolves the utilization of alpha-amylase, amyloglucosidase and glucose isomerase. Fructose can be alternatively produced by the enzymatic hydrolysis of inulin, a polymer of fructose stored as reserve in a number of Asteraceae species. Using only one enzymatic step, inulin can be converted into syrups containing up to 95% fructose. In the present work, fructose syrup was produced from inulin of Vernonia herbacea by hydrolysis with extracellular inulinases from Penicillium janczewskii and evaluated with respect to the effect on plasma glucose level in diabetic rats. Reduction of ca. 46% (p<1% Tukey test of glucose levels in the plasma and no mortality were observed when rats were treated with hydrolysate of inulin. The high amounts of inulin stored by V

  6. Estudo pré-analítico e de validação para determinação de malondialdeído em plasma humano por cromatografia líquida de alta eficiência, após derivatização com 2,4-dinitrofenilhidrazina Preanalytical and validation studies for the determination of malondialdehyde in human plasma through high performance liquid chromatography after derivatization with 2,4-dinitrophenylhydrazine

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    Marina Venzon Antunes

    2008-06-01

    Full Text Available O malondialdeído (MDA é um importante biomarcador utilizado na avaliação do estresse oxidativo. O objetivo deste estudo foi desenvolver uma metodologia para a quantificação plasmática de MDA, através de cromatografia líquida de alta eficiência com detecção por arranjo de diodos (CLAE-DAD, após processo de derivatização com 2,4-dinitrofenilhidrazina (DNPH, avaliando as principais variáveis pré-analíticas. A curva de calibração em plasma (0 a 40 µM apresentou elevada linearidade (r²=0,998. Os principais parâmetros de validação foram: recuperação absoluta: 78%; limite de detecção: 0,11 µM e limite de quantificação: 0,38 µM. Os valores de MDA determinados em indivíduos adultos saudáveis (n=38 foram 3,31 ± 0,38 µM (média ± DP. Estudos de estabilidade do padrão de MDA, reagente derivatizante e MDA plasmáticos, indicaram que a solução padrão pode ser armazenada a -20 e 4 ºC.Malondialdehyde (MDA is an important biomarker for the evaluation of oxidative stress status. The aim of this study was to develop a method for plasma MDA quantification by high performance liquid chromatography with diode-array detection (HPLC-DAD, following derivatization with 2,4-dinitrophenylhydrazine (DNPH, evaluating the main preanalytical variables. The calibration curve in plasma (0 to 40 µM presented high linearity (r² = 0.998. Main validation parameters were: recovery: 78%; LOD: 0.11 µM and LOQ: 0.38 µM. The MDA values obtained in healthy volunteers (n=38 were 3.31 ± 0.38 µM (mean ± SD. Stability studies of MDA standard solution and derivatizing reagent and plasma MDA indicated that the standard solution can be stored at -20 and 4 ºC, remaining stable for at least 30 days.

  7. Correlación y conversión entre los valores de actividad de la colinesterasa plasmática medida por tres técnicas diferentes Correlation and conversion of plasma cholinesterase activity values using three techniques

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    Jaime Carmona-Fonseca

    2007-07-01

    Full Text Available OBJETIVO: Determinar las relaciones matemáticas entre tres técnicas cuantitativas empleadas para medir la actividad de la colinesterasa plasmática, a partir de los valores de referencia ya establecidos para dos poblaciones de Antioquia, Colombia. MÉTODOS:Diseño descriptivo, transversal y prospectivo. Se conformaron dos muestras independientes representativas de la población laboral adulta (18-65 años, no expuesta a plaguicidas inhibidores de la colinesterasa y vinculada al Seguro Social, del valle de Aburrá (415 personas y del cercano oriente antioqueño (412 personas, del departamento de Antioquia, Colombia. La colinesterasa plasmática (EC 3.1.1.8 se midió mediante tres técnicas cuantitativas: Michel, EQM® y Monotest®. Se elaboraron ecuaciones de regresión que relacionaran entre sí los resultados de las tres técnicas estudiadas. RESULTADOS: Se definieron seis ecuaciones de regresión lineal simple que permitieron relacionar los resultados de las tres técnicas de medición de colinesterasa plasmática analizadas. La correlación entre las técnicas fue moderada (r: de 0,686 a 0,771, pero aumentó (r: de 0,744 a 0,811 al eliminar 12 (1,5% valores extremos. Las asociaciones entre las técnicas fueron altamente significativas (P OBJECTIVES: To determine mathematical correlations of three quantitative techniques to measure plasma cholinesterase, using reference values already established for two populations in the department of Antioquia, Colombia. METHODS: In this descriptive, cross-sectional, prospective study, two independent, representative samples of working adults (18 to 65 years old were examined. In both samples the adults worked for businesses associated with Colombia’s Social Security system. Adults in the two samples had not been exposed to cholinesterase-inhibiting pesticides. The samples were from two neighboring regions of the department of Antioquia: one sample (415 adults was from the Aburrá Valley, and the other

  8. Obtención de recubrimientos autolubricados por proyección térmica de plasma atmosférico (APS como alternativa a los lubricantes líquidos

    Directory of Open Access Journals (Sweden)

    Guilemany, J. M.

    2005-08-01

    Full Text Available The low friction coefficient coatings are a new approach to substitution of oil lubricated systems. The introduction of a solid lubricant in a matrix with good mechanical properties gives to the system a low friction coefficient and improves the wear resistance of the coating. These new systems can be used at high temperatures where liquid lubricants fail. Ni-Graphite and Cr2O3-CaF2 self-lubricated coatings have been produced by Atmospheric Plasma Spray (APS, in the Thermal Spray Center of the University of Barcelona. The effect of graphite and CaF2 on the metallic matrix and coatings properties has been studied. It was observed that the wear was low in both systems, but the friction coefficients are very different. The results show that the Ni-Graphite coatings has an good behaviour and can be used as alternative to liquids lubricants.

    La obtención de recubrimientos con bajos coeficientes de fricción, es una innovadora respuesta a la creciente demanda industrial de alternativas para los tradicionales sistemas lubricados con aceites. Para este fin, la introducción de un sólido lubricante, en una matriz con buenas propiedades mecánicas, ha de conferir al conjunto un bajo coeficiente de fricción y mejorar la resistencia al desgaste del recubrimiento, favoreciendo además, la utilización a elevadas temperaturas, en las que los lubricantes líquidos convencionales presentan limitaciones. En el Centro de Proyección Térmica (CPT de la Universidad de Barcelona se han obtenido mediante proyección de Plasma Atmosférico (APS recubrimientos autolubricados de Ni-Grafito y Cr2O3-CaF2, estudiando con especial interés las propiedades y el efecto que produce el grafito y el CaF2 en las matrices metálica y cerámica respectivamente. Se ha determinado en los dos casos que el desgaste originado en los recubrimientos es bajo, si bien los coeficientes de fricción varían ostensiblemente en función del sistema indicado. Los resultados obtenidos

  9. Balanço de nutrientes em povoamento de Eucalyptus saligna implantado sobre Cambissolo Háplico no RS Nutrient balance in plantation of Eucalyptus saligna planted on Inceptisol in Rio Grande do Sul

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    Michael Mazurana

    2011-09-01

    Full Text Available A fragilidade de um sistema florestal pode ser avaliada através do balanço de nutrientes, destacando a eficiência da ciclagem sendo que, em certos casos, a adubação deve ser utilizada para manter ou elevar a produtividade do sistema. Objetivou-se com este estudo avaliar o comportamento de diferentes sistemas de preparo de solo em Cambissolo Háplico e sua influência nas perdas de nutrientes transportados por erosão em área cultivada com Eucalyptus saligna. Os tratamentos foram constituídos por quatro métodos de preparo do solo: subsolagem interrompida com resíduo (SIR, subsolagem contínua com resíduo (SCR, subsolagem contínua sem resíduo (SSR e coveamento mecânico (CME, em delineamento de blocos ao acaso com três repetições por tratamento. O sistema SSR apresentou as maiores perdas de nutrientes quando comparadas com as dos outros métodos de preparo de solo. As maiores perdas de nutrientes pela erosão hídrica foram, pela ordem, K > Ca > Mg > P > Cu > B. Os sistemas de preparo SIR e SSR apresentaram os maiores teores de nutrientes contidos na parte aérea e o menor balanço nutricional, respectivamente.The forest system fragility can be evaluated through nutrient balance, with an emphasis in the cycling efficiency to maintain or elevate of productivity of system. The objective of this study was to evaluate the effects of different soil tillage systems on nutrient losses transported by erosion on an Inceptisol with Eucalyptus saligna. Four tillage systems were tested: interrupted deep chiseling with residue (SIR, continuous deep chiseling with residue (SCR, continuous deep chiseling without residue (SSR and mechanical pitting (CME. The SIR system showed the greatest nutrient losses. The loss of nutrients was higher by water erosion, in the following order, K > Ca > Mg > P > Cu > B. SIR and SSR tillage systems had the highest levels of nutrients in shoots and lower nutritional balance, respectively.

  10. Análisis de la respuesta mecánica de recubrimientos elaborados mediante proyección térmica por plasma usando la medición de esfuerzos residuales y el método de elementos finitos a escala estructural: efecto de la red de poros Mechanical responses of plasma sprayed coatings from residual stress measurements and finite element analysis: effect of the pore network architecture

    Directory of Open Access Journals (Sweden)

    Claudia Constanza Palacio Espinosa

    2011-12-01

    Full Text Available En el presente trabajo se estudia la respuesta mecánica de recubrimientos elaborados mediante proyección térmica por plasma ante la presencia de esfuerzos residuales y campos de esfuerzos generados por deformaciones. Para lograr este propósito, se midieron los esfuerzos residuales durante el proceso de elaboración de recubrimientos de TiO2-Cu y se evaluó el efecto de la red de poros en la estructura de la capa obtenida a partir de imágenes de alta resolución de Microscopía Electrónica de Barrido (MEB obtenidas de los recubrimientos de Al2O3-13TiO2, las cuales fueron posteriormente procesadas y discretizadas para su análisis mediante el Método de Elementos Finitos (MEF. Algunos parámetros operacionales empleados para elaborar los recubrimientos, tales como el flujo de gases y la corriente eléctrica, necesarios para formar el plasma, mostraron tener influencia en el contenido de poros, densidad de grietas y orientación de las mismas y en la magnitud de los esfuerzos residuales provocados. Los esfuerzos residuales determinados a partir de mediciones de deflexión durante la elaboración de los recubrimientos de TiO2-Cu, permitieron identificar su naturaleza, mientras que las simulaciones numéricas mostraron la gran influencia de la red de poros sobre el campo de esfuerzos de los recubrimientos de Al2O3-13TiO2. Del mismo modo, mediante MEF se evaluaron otras composiciones teóricas a través de la modificación de las propiedades mecánicas intrínsecas de las fases constituyentes. Para los casos considerados, las simulaciones mostraron la pobre influencia que tiene la presencia de los constituyentes secundarios en el campo de esfuerzos de los recubrimientos.This study aims a better understanding residual stress and stress field within composite plasma sprayed coatings submitted to strains. In order to reach out this objective, residual stress techniques can be implemented for measurements during elaboration of coatings and finite

  11. Apendicitis por Paracoccidioides brasiliensis.

    OpenAIRE

    MUÑOZ URRIBARRI, Ana Beatriz; CHAPARRO DAMMERT, Eduardo; FERRUFINO LLACH, Juan Carlos; VASQUEZ FLORES, Luciola

    2012-01-01

    La paracoccidioidomicosis es la micosis más prevalente en Sudamérica. La forma aguda afecta el sistema fagocítico mononuclear de niños y personas inmunocomprometidas. El compromiso gastrointestinal es frecuente y su patogenia implica diseminación hematógena y linfática. La linfadenomegalia abdominal causa obstrucción intestinal y abdomen agudo. En este artículo damos a conocer el caso de un niño con compromiso gastrointestinal por apendicitis. Este es el primer caso reportado de apendicitis p...

  12. Meningitis por Streptococcus suis

    OpenAIRE

    Geffner Sclarsky, D. E.; Moreno Muñoz, R.; Campillo Alpera, Mª.S.; Pardo Serrano, F.J.; Gómez Gómez, A.; Martínez-Lozano, Mª.D.

    2001-01-01

    La infección humana por Streptococcus suis (S. suis) es una zoonosis, con un riesgo ocupacional conocido y que suele presentarse como meningitis purulenta, que tiene baja mortalidad y frecuentes secuelas de hipoacusia y ataxia. Se han publicado menos de 150 casos humanos desde el informe original de hace 30 años. Hay una reconocida distribución geográfica viviendo la mayoría de los afectados en el norte de Europa y el sudeste Asiático. En España se han comunicado dos pacientes con enfermedad ...

  13. Por mil devaluados pesos

    Directory of Open Access Journals (Sweden)

    Annie Rodríguez Collázos

    2013-03-01

    Full Text Available El estudio de lo popular y lo urbano hasta ahora se ha centrado en el comportamiento y en algunas relaciones de los habitantes con su entorno. “Por mil devaluados pesos. Publicidad popular y urbana”, pretende explorar las formas de publicidad, dispersas en diferentes espacios populares y urbanos en Bogotá, identificando esquemas y formas características de sus propios códigos comunicativos; se centran en un objeto de estudio consistente en las estrategias publicitarias y los códigos comunicativos en los mensajes publicitarios populares en las subculturas de San Victorino, 7 de Agosto y Sanandresito de San José.

  14. Análise de ácidos graxos não-esterificados de plasma humano por cromatografia gasosa capilar com injeção sem divisão de fluxo Analysis of non-esterified fatty acids in human plasma by capillary gas-chromatography with splitless injection

    Directory of Open Access Journals (Sweden)

    Jacqueline G. Ney

    2004-08-01

    Full Text Available The aim of the present work was to test the combination of non-esterified fatty acid (NEFA isolation using fumed silicon dioxide with capillary gas-chromatography (C-GC with splitless injection for the analysis of NEFAs in human plasma. Injection volume, solvent re-condensation and split purge flow-rate were the parameters evaluated for the analysis of fatty acid methyl esters by C-GC. The use of a solvent re-condensation technique, associated with 1.0 µL injection and a split purge flow rate of 80 mL/min resulted in satisfactory analysis of NEFAs. Fourteen fatty acids were identified in plasma samples, ranging from 2.03 to 184.0 µmol/L. The combination of both techniques proved useful for routine analyses of plasma NEFAs.

  15. Plasma spot welding of ferritic stainless steels

    Directory of Open Access Journals (Sweden)

    Lešnjak, A.

    2002-06-01

    Full Text Available Plasma spot welding of ferritic stainless steels is studied. The study was focused on welding parameters, plasma and shielding gases and the optimum welding equipment. Plasma-spot welded overlap joints on a 0.8 mm thick ferritic stainless steel sheet were subjected to a visual examination and mechanical testing in terms of tension-shear strength. Several macro specimens were prepared. Plasma spot welding is suitable to use the same gas as shielding gas and as plasma gas, i.e., a 98 % Ar/2 % H 2 gas mixture. Tension-shear strength of plasma-spot welded joints was compared to that of resistance-spot welded joints. It was found that the resistance welded joints withstand a somewhat stronger load than the plasma welded joints due to a larger weld spot diameter of the former. Strength of both types of welded joints is approximately the same.

    El artículo describe el proceso de soldeo de aceros inoxidables ferríticos por puntos con plasma. La investigación se centró en el establecimiento de los parámetros óptimos de la soldadura, la definición del gas de plasma y de protección más adecuado, así como del equipo óptimo para la realización de la soldadura. Las uniones de láminas de aceros inoxidables ferríticos de 0,8 mm de espesor, soldadas a solape por puntos con plasma, se inspeccionaron visualmente y se ensayaron mecánicamente mediante el ensayo de cizalladura por tracción. Se realizaron macro pulidos. Los resultados de la investigación demostraron que la solución más adecuada para el soldeo por puntos con plasma es elegir el mismo gas de plasma que de protección. Es decir, una mezcla de 98 % de argón y 2 % de hidrógeno. La resistencia a la cizalladura por tracción de las uniones soldadas por puntos con plasma fue comparada con la resistencia de las uniones soldadas por resistencia por puntos. Se llegó a la conclusión de que las uniones soldadas por resistencia soportan una carga algo mayor que la uniones

  16. Determination of the oxidation mechanism to Cd Te obtained by rf reactive magnetron sputtering in a plasma of Ar-N{sub 2}O; Determinacion del mecanismo de oxigenacion del CdTe obtenido por rf sputtering reactivo con magnetron en un plasma de Ar-N{sub 2}O

    Energy Technology Data Exchange (ETDEWEB)

    Caballero B, F.; Zapata N, A.; Bartolo P, P.; Castro R, R.; Zapata T, M.; Cauich, W.; Pena, J.L. [Departamento de Fisica Aplicada, Centro deInvestigacion y de Estudios Avanzados, Instituto Politecnico Nacional, Unidad Merida, Apartado postal 73, Cordemex, 97310 Merida, Yucatan (Mexico)

    1998-12-31

    In this work we did studies to determinate the oxidation site and incorporation mechanism of oxygen to Cd Te, when preparing Cd Te:O thin films by r f reactive magnetron sputtering, using a Cd Te target and a controlled plasma of Ar-N{sub 2}O. We study the influence in the oxygen content in films due to the variation of N{sub 2}O partial pressure, plasma power and substrate position. We monitored the process in situ by mass spectrometry to determinate the variation of present compounds when varying the N{sub 2}O partial pressure and plasma power. Thin films composition was determined by Auger electron spectroscopy and their structure by X-ray diffraction. We demonstrate that oxygen incorporation has place mainly in the substrate, forming an amorphous Cd Te:O film. We found that exists Cd Te oxidation without using nitrous oxide, may be due to residual atmosphere. We demonstrate that Cd Te oxidation depends on nitrous oxide partial pressure and plasma power. We found that deposition rate of Cd Te:O thin films depend on nitrous oxide interaction with Cd Te in the target and on the chamber walls. We propose a reaction mechanism to explain the oxygen incorporation to Cd Te. (Author)

  17. Plasma turbulence

    International Nuclear Information System (INIS)

    Horton, W.

    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

  18. Sepsis por shigella flexneri

    Directory of Open Access Journals (Sweden)

    César Cabrera C

    2005-04-01

    Full Text Available Se presenta un caso raro de sepsis por Shigella flexneri en una paciente de 45 años de edad quien estando hospitalizada para el estudio de un tumor cerebral, requirió el uso de manitol y dosis altas de corticoides; luego de ello presenta deposiciones líquidas con moco y sangre, desarrolla síndrome de respuesta inflamatoria sistémica, luego se aísla Shigella flexneri en el hemocultivo; recibió tratamiento antibiótico con ciprofloxacina. Se describen las características del caso y se comenta de acuerdo con la revisión de literatura.

  19. Portable exhausters POR-004 SKID B, POR-005 SKID C, POR-006 SKID D storage plan

    International Nuclear Information System (INIS)

    Nelson, O.D.; Keller, G.M.

    1997-01-01

    This document provides a storage plan for portable exhausters POR-004 SKID B, POR-005 SKID C, AND POR-006 SKID D. The exhausters will be stored until they are needed by the TWRS (Tank Waste Remediation Systems) Saltwell Pumping Program. The storage plan provides criteria for portable exhauster storage, periodic inspections during storage, and retrieval from storage

  20. Energy recovery of the H{sub 2}S and CO{sub 2} elimination with technology by hybrid plasma; Recuperacion energetica de la eliminacion de H{sub 2}S y CO{sub 2} con tecnologia por plasma hibrido

    Energy Technology Data Exchange (ETDEWEB)

    Salazar T, J. A.

    2014-07-01

    This document is a research focused on energy recovery from acid gas removal contained in natural gas as hydrogen sulfide (H{sub 2}S) and carbon dioxide (CO{sub 2}), by obtaining highly energetic gas such as syngas (mixture of hydrogen and carbon monoxide, in particular) using plasma technology in its hybrid form, namely, gliding arc plasma, that has the property to behave like a thermal plasma and cold plasma, besides possessing among other virtues the ability to treat large flows continuously at atmospheric pressure without the need of using noble gases, with a power consumption of no more than 1000 W. Furthermore, this type of plasma has demonstrated to be a clean and efficient not only by high conversion rates of H{sub 2}S (86%) and CO{sub 2} (56%) and high percentages of selectivity in the production of hydrogen (H{sub 2}) and carbon monoxide carbon (CO) obtained in this work, but because it can even be seriously considered to replace other technologies currently used in the process of sweetening natural gas as adsorption, absorption and sequestering membranes. The results shown are based on a series of analysis, simulations, experiments and calculations, from the design of the plasma generating source based on an impulse-phase circuit, to the electrical characterization results and simulation by acquiring electrical signals, without forgetting the characterization of the resulting chemical components using various analytical techniques such as mass spectrometry, gas chromatography (GC), optical emission spectroscopy (OES), optical spectroscopy Fourier inverse transformed (XRD) and scanning electron microscopy (Sem), X-ray diffraction (XRD) and multi-gas detectors (iBrid MX6). Additionally, performed chemical kinetics and reaction mechanism of the compounds involved in the degradation of H{sub 2}S and CO{sub 2} similar to those experienced as well as the study of energy efficiency (Ece), specific energy (Se), all this to meet a projects needs 127499, entitled

  1. Plasma properties

    International Nuclear Information System (INIS)

    Weitzner, H.

    1990-06-01

    This paper discusses the following topics: MHD plasma activity: equilibrium, stability and transport; statistical analysis; transport studies; edge physics studies; wave propagation analysis; basic plasma physics and fluid dynamics; space plasma; and numerical methods

  2. Plasma accelerators

    International Nuclear Information System (INIS)

    Bingham, R.; Angelis, U. de; Johnston, T.W.

    1991-01-01

    Recently attention has focused on charged particle acceleration in a plasma by a fast, large amplitude, longitudinal electron plasma wave. The plasma beat wave and plasma wakefield accelerators are two efficient ways of producing ultra-high accelerating gradients. Starting with the plasma beat wave accelerator (PBWA) and laser wakefield accelerator (LWFA) schemes and the plasma wakefield accelerator (PWFA) steady progress has been made in theory, simulations and experiments. Computations are presented for the study of LWFA. (author)

  3. Control Multivariable por Desacoplo

    Directory of Open Access Journals (Sweden)

    Fernando Morilla

    2013-01-01

    Full Text Available Resumen: La interacción entre variables es una característica inherente de los procesos multivariables, que dificulta su operación y el diseño de sus sistemas de control. Bajo el paradigma de Control por desacoplo se agrupan un conjunto de metodologías, que tradicionalmente han estado orientadas a eliminar o reducir la interacción, y que recientemente algunos investigadores han reorientado con objetivos de solucionar un problema tan complejo como es el control multivariable. Parte del material descrito en este artículo es bien conocido en el campo del control de procesos, pero la mayor parte de él son resultados de varios años de investigación de los autores en los que han primado la generalización del problema, la búsqueda de soluciones de fácil implementación y la combinación de bloques elementales de control PID. Esta conjunción de intereses provoca que no siempre se pueda conseguir un desacoplo perfecto, pero que sí se pueda conseguir una considerable reducción de la interacción en el nivel básico de la pirámide de control, en beneficio de otros sistemas de control que ocupan niveles jerárquicos superiores. El artículo resume todos los aspectos básicos del Control por desacoplo y su aplicación a dos procesos representativos: una planta experimental de cuatro tanques acoplados y un modelo 4×4 de un sistema experimental de calefacción, ventilación y aire acondicionado. Abstract: The interaction between variables is inherent in multivariable processes and this fact may complicate their operation and control system design. Under the paradigm of decoupling control, several methodologies that traditionally have been addressed to cancel or reduce the interactions are gathered. Recently, this approach has been reoriented by several researchers with the aim to solve such a complex problem as the multivariable control. Parts of the material in this work are well known in the process control field; however, most of them are

  4. Plasma rico en plaquetas Platelet -rich plasma

    OpenAIRE

    J. González Lagunas

    2006-01-01

    El Plasma Rico en Plaquetas es una suspensión concentrada de la sangre centrifugada que contiene elevadas concentraciones de trombocitos. Durante los últimos años, este producto ha aparecido de forma repetida en publicaciones científicas y en medios de comunicación generales como un producto que por sus características induce la curación y regeneración de los tejidos. La premisa de su uso es que las elevadas concentraciones de plaquetas en el PRP, liberan cantidades significativas de factores...

  5. Plasma device

    International Nuclear Information System (INIS)

    Thode, L.E.

    1981-01-01

    A method is described for electron beam heating of a high-density plasma to drive a fast liner. An annular or solid relativistic electron beam is used to heat a plasma to kilovolt temperatures through streaming instabilities in the plasma. Energy deposited in the plasma then converges on a fast liner to explosively or ablatively drive the liner to implosion. (U.K.)

  6. Plasma Modes

    Science.gov (United States)

    Dubin, D. H. E.

    This chapter explores several aspects of the linear electrostatic normal modes of oscillation for a single-species non-neutral plasma in a Penning trap. Linearized fluid equations of motion are developed, assuming the plasma is cold but collisionless, which allow derivation of the cold plasma dielectric tensor and the electrostatic wave equation. Upper hybrid and magnetized plasma waves in an infinite uniform plasma are described. The effect of the plasma surface in a bounded plasma system is considered, and the properties of surface plasma waves are characterized. The normal modes of a cylindrical plasma column are discussed, and finally, modes of spheroidal plasmas, and finite temperature effects on the modes, are briefly described.

  7. Efectos del policosanol en los modelos de pleuresía inducida por carragenina y granuloma por algodón

    Directory of Open Access Journals (Sweden)

    Daisy Carbajal Quintana

    Full Text Available Introducción: el policosanol, mezcla de alcoholes alifáticos primarios superiores purificada de la cera de caña, inhibe la actividad de la cicloxigenasa-1 (COX-1 in vitro, efecto que pudiera sustentar su acción antiagregante plaquetaria. Sin embargo, sus posibles efectos en modelos experimentales de inflamación no se habían investigado. Objetivo: determinar el efecto antinflamatorio in vivo del policosanol en un modelo de inflamación aguda (pleuresía por carragenina y crónico (granuloma por algodón. Métodos: se distribuyeron las ratas Sprague Dawley en siete grupos para el modelo de inflamación aguda: un control negativo (vehículo y seis a los que se les indujo la inflamación: un control positivo (vehículo, cuatro tratados con policosanol (50-800 mg/kg y uno con aspirina (100 mg/kg. Se cuantificaron a las 5 h el volumen de exudado pleural, la concentración de proteínas y actividad de la enzima mieloperoxidasa. Se distribuyeron las ratas en seis grupos para el modelo crónico: un control (vehículo, cuatro tratados con policosanol (50-800 mg/kg y uno con aspirina (100 mg/kg. Se extrajo el granuloma para determinar los pesos húmedo y seco seis días después de implantado el pellet. Resultados: dosis orales únicas de policosanol (200, 400 y 800 mg/kg redujeron significativa y moderadamente el volumen, la actividad de la enzima mieloperoxidasa (» 12 % y la concentración de proteínas (» 20 % del exudado pleural, mientras la aspirina redujo estos indicadores en un 35,3, 19,9 y 19,1%, respectivamente. La administración oral de policosanol (400 y 800 mg/kg durante 6 días disminuyó significativa y moderadamente el peso húmedo del granuloma (16,4 y 16,2 %, y el peso seco (28,4 y 34,4 %. La aspirina 100 mg/kg redujo estas variables en un 18,5 % (peso húmedo y 34,4 % (peso seco. Ambos tratamientos produjeron mayores reducciones del peso seco que del peso húmedo del granuloma. Conclusiones: la administración oral de policosanol

  8. PARAFAC: uma ferramenta quimiométrica para tratamento de dados multidimensionais. Aplicações na determinação direta de fármacos em plasma humano por espectrofluorimetria PARAFAC: a chemometric tool for multi-dimensional data treatment. Applications in direct determination of drugs in human plasma by spectrofluorimetry

    Directory of Open Access Journals (Sweden)

    Marcelo M. Sena

    2005-10-01

    Full Text Available Since the last decade, the combined use of chemometrics and molecular spectroscopic techniques has become a new alternative for direct drug determination, without the need of physical separation. Among the new methodologies developed, the application of PARAFAC in the decomposition of spectrofluorimetric data should be highlighted. The first objective of this article is to describe the theoretical basis of PARAFAC. For this purpose, a discussion about the order of chemometric methods used in multivariate calibration and the development of multi-dimensional methods is presented first. The other objective of this article is to divulge for the Brazilian chemical community the potential of the combination PARAFAC/spectrofluorimetry for the determination of drugs in complex biological matrices. For this purpose, two applications aiming at determining, respectively, doxorrubicine and salicylate in human plasma are presented.

  9. Plasma centrifuges

    International Nuclear Information System (INIS)

    Karchevskij, A.I.; Potanin, E.P.

    2000-01-01

    The review of the most important studies on the isotope separation processes in the rotating plasma is presented. The device is described and the characteristics of operation of the pulse plasma centrifuges with weakly and strongly ionized plasma as well as the stationary plasma centrifuges with the medium weak ionization and devices, applying the stationary vacuum arc with the high ionization rate and the stationary beam-plasma discharge with complete ionization, are presented. The possible mechanisms of the isotope separation in plasma centrifuges are considered. The specific energy consumption for isotope separation in these devices is discussed [ru

  10. 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

  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. Poder e ideologia: o modelo corporativo de gestão por competências em uma indústria multinacional

    Directory of Open Access Journals (Sweden)

    Cinthia Leticia Ramos

    2014-06-01

    Full Text Available http://dx.doi.org/10.5007/2175-795X.2014v32n2p667 Sendo as organizações permeadas por relações complexas e contraditórias desencadeadas por mecanismos de poder, ideologia e controle, interessa analisar no presente artigo de que forma estas relações se manifestam no discurso de Gestão por Competência, mediante análise crítica do modelo corporativo implantado em uma Indústria Multinacional, aqui denominada Indústria ALFA, a partir de duas categorias de Análise: Poder e Ideologia. As fontes dos dados empíricos são os documentos institucionais da Indústria ALFA que definem e orientam os procedimentos da Gestão por Competência. A técnica de coleta e análise dos dados será a Análise de Conteúdo segundo a proposta de Bardin e Franco. O enfoque que orienta o problema de pesquisa se dará em torno do sujeito coletivo e sua relação estabelecida com o conjunto de regras e comportamentos ideológicos impostos pela organização o qual se materializa através da submissão, da alienação e da servidão voluntária nas organizações. A base conceitual que dará suporte para sustentação desta investigação levará em consideração uma concepção teórica crítica das formas de poder e controle nas organizações concretas.

  13. Substituição de uréia por cloreto de amônio em dietas de bovinos: digestibilidade, síntese de proteína microbiana, parâmetros ruminais e sanguíneos = Replacing urea with ammonium chloride in cattle diets: digestibility, synthesis of microbial protein, and rumen and plasma parameters

    Directory of Open Access Journals (Sweden)

    Roman David Castañeda

    2009-07-01

    Full Text Available Foram utilizados cinco bovinos machos, castrados, da raça Holandesa Preta e Branca, com 450 kg de peso vivo em um delineamento quadrado latino 5 x 5, sendo os tratamentos cinco níveis de substituição, 0, 25, 50, 75 e 100% de ureia por cloreto de amônio, como fontes de nitrogênio não-proteico da dieta. Houve redução linear (p 0,05 a excreção de alantoína e de derivados de purinas na urina, purinas absorvidas, síntese de compostos nitrogenados microbianos e eficiência de síntese de proteína microbiana. Houve queda linear (p 0,05 a concentração de amônia no rúmen. O cloreto de amônio pode ser utilizado como fonte de NNP para bovinos em níveis de até 1,4% da matéria seca total da dieta.Five Holstein steers weighting 450 kg were used in a 5 x 5 Latin square statistical design, where treatments consisted of five replacement levels: 0, 25, 50, 75 and 100% of urea by ammonium chloride, as non-protein nitrogen in the diet. There was a linear decrease (p 0.05 daily excretion of allantoin, purine derivatives, absorbed purines, as well as microbial nitrogen compounds and microbial efficiency synthesis. Rumen pH and plasma urea nitrogen decreased linearly (p 0.05 ruminal ammonia concentration as urea was replaced by ammonium chloride. Ammonium chloride can be used as a nonprotein nitrogen source in ruminant diets up to level of 1.4% of diet dry matter.

  14. Desempenho físico-químico de filmes hidrofóbicos de AlN e de Ti nanoestruturado crescidos por plasma frio sobre superfícies de isoladores cerâmicos de porcelana tipo pino

    Directory of Open Access Journals (Sweden)

    M. M. Mazur

    2016-03-01

    Full Text Available Resumo A resistência mecânica e a propriedade dielétrica de isoladores cerâmicos são características fundamentais para o suporte das redes de distribuição de energia elétrica. Porém, tanto a umidade quanto o teor de poluentes na atmosfera podem vir a ser prejudiciais e causar falhas na entrega de energia por elevação da sua corrente elétrica de fuga. O vidrado do isolador tem grande afinidade com a água resultante da interação da superfície do vidro com a atmosfera. No presente trabalho, foi realizada a deposição de filmes de nitreto de alumínio sobre o vidrado de amostras de isoladores elétricos cerâmicos, via plasma "magnetron sputtering" pulsado, de corrente contínua, e com uma mistura dos gases argônio e nitrogênio e de Ti sobre isoladores tipo pino para classes de tensão de 15 kV. A morfologia dos filmes e o desempenho dos isoladores foram medidos por MEV-FEG/EDS, AFM, máxima corrente de fuga RMS e grau de hidrofobicidade. O comportamento dos filmes depositados medido pelo grau de hidrofobicidade reduziu nas amostras de CM6 para CM4, com AlN, e de CM7 para CM3 quando foi depositado o Ti. A máxima corrente de fuga RMS medida nos isoladores sem e com filme nanométrico à base de Ti foi superior nos dispositivos sem a proteção, alcançando valores medidos de 5 mA e com desligamento do sistema computadorizado de medida (após 3 dias em Sauípe e 3 meses em Pituba em consequência desta ter superado o intervalo de segurança de curto circuito estabelecido nos dispositivos eletrônicos de proteção (surtos superiores a 300 mA. Com a deposição dos filmes em 7 isoladores, foram verificadas alterações de comportamento em dois destes, com picos de máxima corrente de fuga atingindo 2,4 mA no campo. A maioria dos isoladores analisados teve como variações de correntes de fuga RMS, no período de medida, entre 0,2 e 2 mA, em condições adversas de clima (com chuva e diferentes velocidades de vento.

  15. Mice plasma fibrinogen consumption by thrombin-like enzyme present in rattlesnake venom from the North-East region of Argentina Consumo de fibrinógeno plasmático en ratones por acción de enzima con actividad trombínica presente en el veneno de cascabel del nordeste argentino

    Directory of Open Access Journals (Sweden)

    Silvana L. Maruñak

    2004-12-01

    Full Text Available Due to variability of venom components from the same species of snakes that inhabit different regions, particular properties of the venom of Crotalus durissus terrificus that inhabits the North-East of Argentina were studied. Gyroxin, a thrombin-like enzyme, was isolated from this venom by gel filtration and affinity chromatography, it was found to be homogeneous according to SDS-PAGE, with a molecular weight of 33 kDa. "Gyroxin syndrome" in mice was tested and it showed changes in the animal behavior, confirming that the isolated thrombin-like enzyme is gyroxin. Effects of this enzyme and the crude venom on mice plasmatic fibrinogen levels were determined. The mice plasma fibrinogen decreased rapidly until incoagulability during the first hour after thrombin-Iike enzyme injection, then reaching its normal level 10 hours after injection; whereas crude venom resulted in a 60% decrease of the mice plasma fibrinogen, reaching its normal level after the same period of time. After 1 hour of gyroxin inoculation, intravascular coagulation was observed in histological cuttings of lung, cardiac muscle and liver. The isolated enzyme showed strong hydrolyzing activity on fibrinogen and fibrin in vitro, whereas the crude venom exhibited weak hydrolyzing activity on both substrates. It is probable that this very low activity is due to the low percentage of the enzyme in the crude venom. Decreasing of plasmatic fibrinogen levels may be due to either the coagulant or hydrolyzing actions of the enzyme.Teniendo en cuenta la variabilidad de los componentes del veneno de serpientes de una misma especie que habitan regiones diferentes, se decidió estudiar las propiedades particulares del veneno de Crotalus durissus terrificus que habita el nordeste de Argentina, Giroxina, una enzima con actividad trombínica, fue aislada del veneno por cromatografía de filtración por gel y de afinidad; se comprobó su homogeneidad y se determinó su peso molecular, 33 kDa, por

  16. Study on water-sediment interaction in samples from Rio das Velhas - Minas Gerais State - Brazil using instrumental neutron activation analysis, and argon plasma coupled mass spectroscopy; Estudo da interacao agua-sedimento em amostras do Rio das Velhas - MG utilizando os metodos: analise por ativacao neutronica instrumental (INAA) e espectrometria de massa acoplada a um plasma de argonio (ICP-MS)

    Energy Technology Data Exchange (ETDEWEB)

    Veado, Maria Adelaide R.V.; Oliveira, Arno H. de [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Dept. de Engenharia Nuclear; Revel, G.; Pinte, G. [CEA Centre d`Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France). Lab. d`Analyse par Activation Pierre Sue; Toulhoat, P. [CEA Centre d`Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France). Unite Mixte de Recherche Analyse et Environnement

    1999-11-01

    Sorption of the metallic elements in aqueous solutions in surface of the hydroxides affects the transport of heavy elements in the freshwaters. Sorption and the chemistry of the hydroxides are important studies for knowledge in geology, waters and waste treatment, and environment studies. In the industrial mining region areas, the river surface waters are subject to modifications in its physical and chemistries properties: pH, DBO, conductivity and alkalinity. Instrumental neutron activation analysis and inductively coupled plasma-mass spectrometry (ICP-MS), have ben used for the determination of toxic heavy metals and others pollutants in the Das Velhas river in State of Minas Gerais, in south-east Brazil. Water samples were collected with acidification on site, which provoked a change of its natural pH. Consequently, metallic elements associated to hydroxides and to particles in suspension were liberated. The objective of this paper is to show the different behavior of any elements, in water of Das Velhas river, with relation of its chemical forms (cations or anions), the solubility degree, the pH and the presence of rare earth elements. (author) 11 refs., 10 figs.; e-mail: adelaide at nuclear.ufmg.br; heeren at nuclear.ufmg.br; grevel at drecam.cea.fr; pierre.toulhoat at cea.fr

  17. Plasma device

    International Nuclear Information System (INIS)

    Thode, L.E.

    1981-01-01

    A method is described of providing electron beam heating of a high-density plasma to drive a fast liner to implode a structured microsphere. An annular relativistic electron beam is used to heat an annular plasma to kilovolt temperatures through streaming instabilities in the plasma. Energy deposited in the annular plasma then converges on a fast liner to explosively or ablatively drive the liner to convergence to implode the structured microsphere. (U.K.)

  18. Porøse materialer

    DEFF Research Database (Denmark)

    Hansen, Ernst Jan de Place

    2000-01-01

    Dette undervisningsnotat er en samling af noter, der refererer til den indledende del af kurset Materialmekanik og Porøse materailer på Insitut for Bærende Konstruktiner og Materialer (BKM).......Dette undervisningsnotat er en samling af noter, der refererer til den indledende del af kurset Materialmekanik og Porøse materailer på Insitut for Bærende Konstruktiner og Materialer (BKM)....

  19. Dusty plasmas

    International Nuclear Information System (INIS)

    Jones, M.E.; Winske, D.; Keinigs, R.; Lemons, D.

    1996-01-01

    This is the final report of a three-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The objective of this project has been to develop a fundamental understanding of dusty plasmas at the Laboratory. While dusty plasmas are found in space in galactic clouds, planetary rings, and cometary tails, and as contaminants in plasma enhanced fabrication of microelectronics, many of their properties are only partially understood. Our work has involved both theoretical analysis and self-consistent plasma simulations to understand basic properties of dusty plasmas related to equilibrium, stability, and transport. Such an understanding can improve the control and elimination of plasma dust in industrial applications and may be important in the study of planetary rings and comet dust tails. We have applied our techniques to the study of charging, dynamics, and coagulation of contaminants in plasma processing reactors for industrial etching and deposition processes and to instabilities in planetary rings and other space plasma environments. The work performed in this project has application to plasma kinetics, transport, and other classical elementary processes in plasmas as well as to plasma waves, oscillations, and instabilities

  20. Plasma chromatography

    International Nuclear Information System (INIS)

    Anon.

    1984-01-01

    This book examines the fundamental theory and various applications of ion mobility spectroscopy. Plasma chromatography developed from research on the diffusion and mobility of ions. Topics considered include instrument design and description (e.g., performance, spectral interpretation, sample handling, mass spectrometry), the role of ion mobility in plasma chromatography (e.g., kinetic theory of ion transport), atmospheric pressure ionization (e.g., rate equations), the characterization of isomers by plasma chromatography (e.g., molecular ion characteristics, polynuclear aromatics), plasma chromatography as a gas chromatographic detection method (e.g., qualitative analysis, continuous mobility monitoring, quantitative analysis), the analysis of toxic vapors by plasma chromatography (e.g., plasma chromatograph calibration, instrument control and data processing), the analysis of semiconductor devices and microelectronic packages by plasma chromatography/mass spectroscopy (e.g., analysis of organic surface contaminants, analysis of water in sealed electronic packages), and instrument design and automation (hardware, software)

  1. Establishment of methodology for determination of {sup 93}Zr in radioactive wastes by Liquid Scintillation Counting (LSC) and Inductively Coupled Plasma Mass Spectrometry (ICP-MS); Estabelecimento de metodologia para determinacao de {sup 93}Zr em rejeitos radioativos por Espectrometria de Cintilacao Liquida (LSC) e Espectrometria de Massa com Plasma Indutivamente Acoplado (ICP-MS)

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Thiago Cesar de

    2014-06-01

    The zirconium-93 is a long-lived pure β-particle-emitting radionuclide produced from {sup 235}U fission and from neutron activation of the stable isotope {sup 92}Zr and thus occurring as one of the radionuclides found in nuclear reactors. Due to its long half life, {sup 93}Zr is one of the radionuclides of interest for the performance of assessment studies of waste storage or disposal. Measurement of {sup 93}Zr is difficult owing to its trace level concentration and its low activity in nuclear wastes and further because its certified standards are not frequently available. The aim of this work was to develop a selective radiochemical separation methodology for the determination of {sup 93}Zr in nuclear waste and analyze it by Liquid Scintillation Counting (LSC) and Inductively Coupled Plasma Mass Spectrometry (ICP-MS). To set up the radiochemical separation procedure for zirconium, a tracer solution of {sup 95}Zr and its 724 keV γ-ray measurements by γ- spectrometry were used in order to follow the behavior of zirconium during the radiochemical separation. For the LSC technique a {sup 55}Fe solution, which is one of the major interfering measures zirconium, was used to verify the decontamination factor during the separation process. The efficiency detection for {sup 63}Ni was used to determination of {sup 93}Zr activity in the matrices analyzed. The limit of detection of the 0.05 Bq 1{sup −1} was obtained for {sup 63}Ni standard solutions by using a sample:cocktail ratio of 3:17 mL for Optiphase Hisafe 3 cocktail. For the ICP-MS technique a zirconium stable solution was used to verify the zirconium behavior and recovery during radiochemical separation and a solution of Ba, Co, Eu, Fe, Mn, Nb, Sr and Y was used to verify the decontamination factor during the separation process. A standard solution {sup 93}Nb as isotope for determining the {sup 93}Zr by ICP-MS was used for calibration and analysis. The detection limit of 0.039 ppb was obtained for the standard

  2. Las cosas por su nombre

    OpenAIRE

    Storani, Emilia

    2017-01-01

    El artículo propone indagar sobre los modos y diferentes formatos que se utilizan tanto en la escritura como en la lectura, para articular con las luchas por la identidad de género. La Ley de Identidad de Género ha sido un puntapié clave para pensarnos a nosotros mismos culturalmente y para pensar a los demás. Pero, ¿cómo mencionamos, escribimos y leemos las diferentes identidades? La escritura, también es un mundo transformador para quienes bregan por una sociedad más libre y sin prejuicios....

  3. Ptose palpebral causada por Paquidermoperiostose

    Directory of Open Access Journals (Sweden)

    Patricia Regina de Pinho Tavares

    2014-08-01

    Full Text Available A paquidermoperiostose é uma síndrome caracterizada por acometimento cutâneo e ósseo, e em alguns casos ocorre comprometimento palpebral leve. É uma síndrome rara, idiopática ou hereditária, com provável herança autossômica dominante de penetrância variável. Descreve-se o caso de um paciente com ptose grave por paquidermoperiostose elucidando sua fisiopatologia e conduta cirúrgica aplicada.

  4. Diverticulitis yeyunal perforada por enterolito.

    OpenAIRE

    Marenco De la Cuadra, Beatriz; Gomez-Rosado, Juan-Carlos; Capitan-Morales, Luis-Cristobal; Valdés Hernández, Javier; Reyes-lopera, N.J. De los

    2012-01-01

    La diverticulosis yeyunal es una enfermedad adquirida rara. Casi el 60-70% keeps asymptomátic or Con síntomas crónicos inespecíficos, aunque puede presentarse como un abdomen agudo. La perforación debida a enterolitos es una causa extremadamente rara do complicación, y puede producirse por la impactación de ésta contra la pared intestinal. Presentamos caso de un varón de 82 años que acude a urgencias por un dolor súbito abdominal, difuso, con irritación peritoneal, leucocitosis con neutro...

  5. Mortalidad intrahospitalaria por accidente cerebrovascular

    OpenAIRE

    Federico Rodríguez Lucci; Virginia Pujol Lereis; Sebastián Ameriso; Guillermo Povedano; María F. Díaz; Alejandro Hlavnicka; Néstor A. Wainsztein; Sebastián F. Ameriso

    2013-01-01

    La mortalidad global por accidente cerebrovascular (ACV) ha disminuido en las últimas tres décadas, probablemente debido a un mejor control de los factores de riesgo vascular. La mortalidad hospitalaria por ACV ha sido tradicionalmente estimada entre 6 y 14% en la mayoría de las series comunicadas. Sin embargo, los datos de ensayos clínicos recientes sugieren que esta cifra sería sustancialmente menor. Se revisaron datos de pacientes internados con diagnóstico de ACV del Banco de Datos de Str...

  6. Plasma physics

    CERN Document Server

    Drummond, James E

    1961-01-01

    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

  7. Plasma generator

    International Nuclear Information System (INIS)

    Omichi, Takeo; Yamanaka, Toshiyuki.

    1976-01-01

    Object: To recycle a coolant in a sealed hollow portion formed interiorly of a plasma limiter itself to thereby to cause direct contact between the coolant and the plasma limiter and increase of contact area therebetween to cool the plasma limiter. Structure: The heat resulting from plasma generated during operation and applied to the body of the plasma limiter is transmitted to the coolant, which recycles through an inlet and outlet pipe, an inlet and outlet nozzle and a hollow portion to hold the plasma limiter at a level less than a predetermined temperature. On the other hand, the heater wire is, at the time of emergency operation, energized to heat the plasma limiter, but this heat is transmitted to the limiter body to increase the temperature thereof. However, the coolant recycling the hollow portion comes into direct contact with the limiter body, and since the plasma limiter surround the hollow portion, the heat amount transmitted from the limiter body to the coolant increases to sufficiently cool the plasma limiter. (Yoshihara, H.)

  8. DESAJUSTE EDUCATIVO POR REGIONES EN COLOMBIA: ¿COMPETENCIA POR SALARIOS O POR PUESTOS DE TRABAJO?

    Directory of Open Access Journals (Sweden)

    Maribel Castillo Caicedo

    2007-06-01

    Full Text Available Este trabajo aporta una perspectiva del fenómeno de la sobreeducación, entendida como un desajuste por exceso, entre el nivel educativo alcanzado por el individuo y el exigido por el puesto de trabajo en el cual se desempeña; esto se debe a que existe una demanda laboral estrecha de puestos de trabajo para personas calificadas en Colombia. Se analizan las contribuciones empíricas existentes y el debate sobre las mismas; se examinan las teorías que permiten explicar la existencia de un desajuste educativo y se realiza una revisión de la literatura internacional y nacional sobre el tema. Adicionalmente, se plantean una serie de hipótesis para desarrollar un esquema que permita determinar el comportamiento del individuo en el fenómeno de la sobreeducación.

  9. Consanguinidad por isonimia en Salta

    Directory of Open Access Journals (Sweden)

    Albeza, María V.

    2007-01-01

    Full Text Available Se estimó el coeficiente de parentesco por isonimia para localidades de la Puna, Valle Calchaquí y Valle de Lerma, a fin de evaluar diferentes factores evolutivos que podrían estar afectando la composición genética de la población. A partir de los apellidos de las parejas consignadas en fuentes primarias de información, se estimó la isonimia conyugal o marital, el coeficiente total Ft y sus componentes Fr (inbreeding azaroso y Fn (inbreeding no azaroso. De las localidades estudiadas, en la Puna se ha detectado sólo una pareja isónima en una de ellas, en el Valle Calchaquí, tres y ninguna en el Valle de Lerma. Tanto en el Valle Calchaquí como en el de Lerma, se han estimado valores negativos de Ft, y en la Puna se registran los valores más elevados. En las localidades estudiadas no se cumple el supuesto de transmisión patrilineal de apellidos por lo que los valores de Fr y por ende de Ft podrían estar subestimados. Es por ello que sería necesario contar con información desde otras vertientes metodológicas para corroborar, complementar y manejar cuidadosamente el análisis de los datos y las conclusiones que se obtienen.

  10. Celulitis por citomegalovirus Cytomegalovirus cellulitis

    Directory of Open Access Journals (Sweden)

    A. Ruiz Lascano

    2002-12-01

    Full Text Available Las lesiones cutáneas por citomegalovirus (CMV son infrecuentes y a menudo una manifestación tardía de una enfermedad sistémica, que generalmente anuncia un curso fatal. Comunicamos un caso de celulitis por CMV: una mujer de 70 años con trasplante renal efectuado 1 mes antes de la consulta, terapia inmunosupresora con ciclosporina A y metilprednisona. La paciente ingresó por fiebre, dolor e impotencia funcional en pierna derecha. Comprobamos la existencia de una placa de 8 por 4 cm eritematoedematosa. La tratamos con antibióticos sin mejoría, por lo que realizamos un estudio histopatológico de piel que mostró cambios citopáticos compatibles con infección por CMV. Los cultivos bacteriológicos y micológicos fueron negativos. La inmunohistoquímica específica para CMV y el estudio de reacción en cadena de la polimerasa (PCR de la biopsia de piel fueron positivas, al igual que la antigenemia. El tratamiento con ganciclovir produjo la mejoría del cuadro clínico. En la literatura revisada no hemos encontrado la celulitis como manifestación de enfermedad cutánea por CMV.Cutaneous lesions in CMV infection are rare, often a late manifestation of systemic infection, and usually herald a fatal course. A 70 year-old woman received a kidney transplantation one month before consulting and immunosuppressive therapy that included cyclosporine A and methylprednisone. She complained of fever, local pain in her right leg, and an erythematous and swelling plaque. She was treated with intravenous antibiotics without improvement. A skin biopsy was performed and the tissue obtained was sent for bacterial and fungal cultures as well as for histological examination. Cultures were negative. The biopsy showed CMV cytopathic changes. Immunoperoxidase staining was positive for CMV and polymerase chain reaction (PCR testing revealed CMV DNA. She was treated with ganciclovir with resolution of the lesion. CMV cellulitis is a rare cutaneous manifestation

  11. Bridge between fusion plasma and plasma processing

    International Nuclear Information System (INIS)

    Ohno, Noriyasu; Takamura, Shuichi

    2008-01-01

    In the present review, relationship between fusion plasma and processing plasma is discussed. From boundary-plasma studies in fusion devices new applications such as high-density plasma sources, erosion of graphite in a hydrogen plasma, formation of helium bubbles in high-melting-point metals and the use of toroidal plasmas for plasma processing are emerging. The authors would like to discuss a possibility of knowledge transfer from fusion plasmas to processing plasmas. (T. Ikehata)

  12. Plasma waves

    National Research Council Canada - National Science Library

    Swanson, D. G

    1989-01-01

    ... Swanson, D.G. (Donald Gary), D a t e - Plasma waves. Bibliography: p. Includes index. 1. Plasma waves. QC718.5.W3S43 1989 ISBN 0-12-678955-X I. Title. 530.4'4 88-34388 Printed in the United Sta...

  13. Plasma properties

    International Nuclear Information System (INIS)

    Weitzner, H.

    1991-06-01

    The Magneto-Fluid Dynamics Division continues to study a broad range of problems originating in plasma physics. Its principal focus is fusion plasma physics, and most particularly topics of particular significance for the world magnetic fusion program. During the calendar year 1990 we explored a wide range of topics including RF-induced transport as a plasma control mechanism, edge plasma modelling, further statistical analysis of L and H mode tokamak plasmas, antenna design, simulation of the edge of a tokamak plasma and the L-H transition, interpretation of the CCT experimental results at UCLA, turbulent transport, studies in chaos, the validity of moment approximations to kinetic equations and improved neoclassical modelling. In more basic studies we examined the statistical mechanisms of Coulomb systems and applied plasma ballooning mode theory to conventional fluids in order to obtain novel fluid dynamics stability results. In space plasma physics we examined the problem of reconnection, the effect of Alfven waves in space environments, and correct formulation of boundary conditions of the Earth for waves in the ionosphere

  14. Plasma container

    International Nuclear Information System (INIS)

    Ebisawa, Katsuyuki.

    1985-01-01

    Purpose: To enable to easily detect that the thickness of material to be abraded is reduced to an allowable limit from the outerside of the plasma container even during usual operation in a plasma vessel for a thermonuclear device. Constitution: A labelled material is disposed to the inside or rear face of constituent members of a plasma container undergoing the irradiation of plasma particles. A limiter plate to be abraded in the plasma container is composed of an armour member and heat removing plate, in which the armour member is made of graphite and heat-removing plate is made of copper. If the armour member is continuously abraded under the effect of sputtering due to plasma particles, silicon nitride embedded so far in the graphite at last appears on the surface of the limiter plate to undergo the impact shocks of the plasma particles. Accordingly, abrasion of the limiter material can be detected by a detector comprising gas chromatography and it can easily be detected from the outside of the plasma content even during normal operation. (Horiuchi, T.)

  15. Cosmic plasma

    Energy Technology Data Exchange (ETDEWEB)

    Alfven, H [California Univ., San Diego, La Jolla (USA)

    1981-01-01

    The properties of space plasmas are analyzed, based on laboratory results and data obtained by in situ measurements in the magnetosphere (including the heliosphere). Attention is given to the question of how much knowledge can be gained by a systematic comparison of different regions of plasma, and plasmas are considered with linear dimensions varying from laboratory size up to the Hubble distance. The traditional magnetic field description of plasmas is supplemented by an electric current description and it is demonstrated that many problems are easier to understand with a dualistic approach. Using the general plasma properties obtained, the origin and evolution of the solar system is summarized and the evolution and present structure of the universe (cosmology) is discussed.

  16. Plasma device

    International Nuclear Information System (INIS)

    Thode, L.E.

    1981-01-01

    A relativistic electron beam generator or accelerator produces a high-voltage electron beam which is modulated to initiate electron bunching within the beam which is then applied to a high-density target plasma which typically comprises DT, DD, or similar thermonuclear gas at a density of 10 17 to 10 20 electrons per cubic centimeter. As a result, relativistic streaming instabilities are initiated within the high-density target plasma causing the relativistic electron beam to efficiently deposit its energy into a small localized region of the high-density plasma target. The high-temperature plasma can be used to heat a high Z material to generate radiation. Alternatively, a tunable radiation source is produced by using a moderate Z gas or a mixture of high Z and low Z gas as the target plasma. (author)

  17. Superconducting plasmas

    International Nuclear Information System (INIS)

    Ohnuma, Toshiro; Ohno, J.

    1994-01-01

    Superconducting (SC) plasmas are proposed and investigated. The SC plasmas are not yet familiar and have not yet been studied. However, the existence and the importance of SC plasmas are stressed in this report. The existence of SC plasmas are found as follows. There is a fundamental property of Meissner effect in superconductors, which shows a repulsive effect of magnetic fields. Even in that case, in a microscopic view, there is a region of magnetic penetration. The penetration length λ is well-known as London's penetration depth, which is expressed as δ = (m s /μ 0 n s q s 2 ) 1/2 where m s , n s , q s and μ o show the mass, the density, the charge of SC electron and the permeability in free space, respectively. Because this expression is very simple, no one had tried it into more simple and meaningful form. Recently, one of the authors (T.O.) has found that the length can be expressed into more simple and understandable fundamental form as λ = c/ω ps where c = (ε 0 μ 0 ) -1/2 and ω ps = (n s q s 2 /m s ε 0 ) 1/2 are the light velocity and the superconducting plasma frequency. From this simple expression, the penetration depth of the magnetic field to SC is found as a SC plasma skin depth, that is, the fundamental property of SC can be expressed by the SC plasmas. This discovery indicates an importance of the studies of superconducting plasmas. From these points, several properties (propagating modes et al) of SC plasmas, which consist of SC electrons, normal electrons and lattice ions, are investigated in this report. Observations of SC plasma frequency is also reported with a use of Terahertz electromagnet-optical waves

  18. Plasma rico en plaquetas Platelet -rich plasma

    Directory of Open Access Journals (Sweden)

    J. González Lagunas

    2006-04-01

    Full Text Available El Plasma Rico en Plaquetas es una suspensión concentrada de la sangre centrifugada que contiene elevadas concentraciones de trombocitos. Durante los últimos años, este producto ha aparecido de forma repetida en publicaciones científicas y en medios de comunicación generales como un producto que por sus características induce la curación y regeneración de los tejidos. La premisa de su uso es que las elevadas concentraciones de plaquetas en el PRP, liberan cantidades significativas de factores de crecimiento. En este artículo se van a recoger las evidencias científicas que se han presentado en la literatura médica con respecto al PRP y a la curación ósea, así como las diferentes aplicaciones clínicas que se han sugerido.Platelet-rich plasma is a by-product of centrifuged whole blood that contains high levels of thrombocytes. In the last decade, scientific and media interest has been generated by this product that apparently has the capacity of inducing and promoting tissue healing and regeneration. The premise of its use is that the large number of platelets in PRP release significant amounts of growth factors. In this paper, a critical review of the medical literature regarding PRP and bone healing will be presented. Also, the suggested clinical applications of the product will be addressed.

  19. Nonthermal Radiation Processes in Interplanetary Plasmas

    Science.gov (United States)

    Chian, A. C. L.

    1990-11-01

    RESUMEN. En la interacci6n de haces de electrones energeticos con plasmas interplanetarios, se excitan ondas intensas de Langmuir debido a inestabilidad del haz de plasma. Las ondas Langmuir a su vez interaccio nan con fluctuaciones de densidad de baja frecuencia para producir radiaciones. Si la longitud de las ondas de Langmujr exceden las condicio nes del umbral, se puede efectuar la conversi5n de modo no lineal a on- das electromagneticas a traves de inestabilidades parametricas. As se puede excitar en un plasma inestabilidades parametricas electromagneticas impulsadas por ondas intensas de Langmuir: (1) inestabilidades de decaimiento/fusi5n electromagnetica impulsadas por una bomba de Lang- muir que viaja; (2) inestabilidades dobles electromagneticas de decai- miento/fusi5n impulsadas por dos bombas de Langrnuir directamente opues- tas; y (3) inestabilidades de dos corrientes oscilatorias electromagne- ticas impulsadas por dos bombas de Langmuir de corrientes contrarias. Se concluye que las inestabilidades parametricas electromagneticas in- ducidas por las ondas de Langmuir son las fuentes posibles de radiacio- nes no termicas en plasmas interplanetarios. ABSTRACT: Nonthermal radio emissions near the local electron plasma frequency have been detected in various regions of interplanetary plasmas: solar wind, upstream of planetary bow shock, and heliopause. Energetic electron beams accelerated by solar flares, planetary bow shocks, and the terminal shock of heliosphere provide the energy source for these radio emissions. Thus, it is expected that similar nonthermal radiation processes may be responsible for the generation of these radio emissions. As energetic electron beams interact with interplanetary plasmas, intense Langmuir waves are excited due to a beam-plasma instability. The Langmuir waves then interact with low-frequency density fluctuations to produce radiations near the local electron plasma frequency. If Langmuir waves are of sufficiently large

  20. Esporotricosis diagnosticada por el laboratorio

    Directory of Open Access Journals (Sweden)

    Nelly Ordóñez

    1989-06-01

    Full Text Available De 1976 a 1989 se han diagnosticado 40 casos de esporotricosis en el laboratorio de Micología del Instituto Nacional de Salud. La enfermedad se presentó en pacientes entre 4 y 52 años y tuvo predilección por el sexo masculino: 35 de 40 (87,5%; las formas clínicas más frecuentes fueron la cutánea fija, 18 de 40 (45%, y la linfocutánea, 17 de 40 (42,5%, con localización mayor en miembros superiores, 18 de 40 (45%. El diagnóstico se estableció por el aislamiento del Sporothrix schenckii en 35 de 38 pacientes (92%; los otros dos pacientes se diagnosticaron empleando otras técnicas: inmunofluorescencia directa, intradermorreacción y aglutinación en tubo.

  1. Miasis cutanea por cordylobia anthropophaga

    Directory of Open Access Journals (Sweden)

    Alkorta Gurrutxaga Miriam

    2001-01-01

    Full Text Available El incremento progresivo en el número de personas que viajan a países tropicales ha hecho que las enfermedades importadas adquieran una relevancia cada vez mayor. Las miasis (o infestaciones por larvas de moscas cutáneas se encuentran entre este tipo de enfermedades siendo especialmente frecuentes en países tropicales. A propósito de la observación de un caso de miasis cutánea masiva por Cordylobia antropophaga, que ocurrió en una mujer de 34 años de edad al volver de un viaje a Senegal, se ha efectuado una revisión de los casos de miasis cutáneas forunculoides importadas publicados en España, así como de la biología, patología, tratamiento y prevención de la miasis humana por Cordylobia anthropophaga. El caso referido, se caracterizó por la infestación con un número inusualmente elevado de larvas, no sospechándose su etiología hasta la fase final de la enfermedad. La emergencia continuada de larvas (se recogieron 91 generó en la paciente un estado de ansiedad importante. Finalmente, la eliminación de las larvas provocó una rápida mejoría de la paciente. Aunque los casos de miasis cutánea no tienen la gravedad de otras enfermedades importadas, su conocimiento es necesario desde el punto de vista preventivo, diagnóstico y terapeútico. Es importante proceder a la identificación morfológica de las larvas diferenciándolas de otro tipo de miasis con implicaciones terapéuticas diferentes.

  2. Plasma universe

    International Nuclear Information System (INIS)

    Alfven, H.

    1986-04-01

    Traditionally the views in our cosmic environment have been based on observations in the visual octave of the electromagnetic spectrum, during the last half-century supplemented by infrared and radio observations. Space research has opened the full spectrum. Of special importance are the X-ray-gamma-ray regions, in which a number of unexpected phenomena have been discovered. Radiations in these regions are likely to originate mainly from magnetised cosmic plasma. Such a medium may also emit synchrotron radiation which is observable in the radio region. If we try to base a model of the universe on the plasma phenomena mentioned we find that the plasma universe is drastically different from the traditional visual universe. Information about the plasma universe can also be obtained by extrapolation of laboratory experiments and magnetospheric in situ measurements of plasma. This approach is possible because it is likely that the basic properties of plasma are the same everywhere. In order to test the usefulness of the plasma universe model we apply it to cosmogony. Such an approach seems to be rather successful. For example, the complicated structure of the Saturnian C ring can be accounted for. It is possible to reconstruct certain phenomena 4-5 bilions years ago with an accuracy of better than 1 percent

  3. Plasma physics

    International Nuclear Information System (INIS)

    1979-01-01

    This report contains the papers delivered at the AEB - Natal University summer school on plasma physics held in Durban during January 1979. The following topics were discussed: Tokamak devices; MHD stability; trapped particles in tori; Tokamak results and experiments; operating regime of the AEB Tokamak; Tokamak equilibrium; high beta Tokamak equilibria; ideal Tokamak stability; resistive MHD instabilities; Tokamak diagnostics; Tokamak control and data acquisition; feedback control of Tokamaks; heating and refuelling; neutral beam injection; radio frequency heating; nonlinear drift wave induced plasma transport; toroidal plasma boundary layers; microinstabilities and injected beams and quasilinear theory of the ion acoustic instability

  4. Plasma centrifuge

    International Nuclear Information System (INIS)

    Ikehata, Takashi; Mase, Hiroshi

    1998-01-01

    The plasma centrifuge is one of statistical isotope separation processes which uses the centrifugal force of a J x B driven rotating plasma in a magnetic field to give rise to the mass-dependent radial transport of isotopic ions. The system has been developed as an alternative to the gas centrifuge because a much higher rotational velocity and separation factor have been achieved. In this review, the physical aspects of the plasma centrifuge followed by the recent experimental achievements are described, especially in comparison with the gas centrifuge. (author)

  5. Abdome agudo por obstrução por ileobiliar

    Directory of Open Access Journals (Sweden)

    Márcia Cristina de Alencastro

    Full Text Available OBJETIVO: descrever a experiência na abordagem dos doentes com abdome agudo por obstrução por IB, desde o diagnóstico até o tratamento definitivo. MÉTODOS: estudo retrospectivo incluindo todos os casos de IB tratados em um período de 23 anos. De acordo com a abordagem cirúrgica realizada, os pacientes foram divididos em dois grupos (1 enterolitotomia com colecistectomia no segundo momento; e (2 enterolitotomia, colecistectomia e abordagem da fístula. RESULTADOS: Doze pacientes foram incluídos, sendo 11 mulheres (91,6%, com média de idade de 72,2 anos. Todos os pacientes apresentavam doenças associadas, principalmente hipertensão arterial sistêmica (75%. Dois pacientes não apresentavam sintomas significativos de obstrução intestinal. O diagnóstico de IB foi realizado em seis pacientes (50% antes da laparotomia. O grupo 1 foi constituído de oito pacientes e o grupo 2 de quatro, e a morbidade foi, respectivamente, 33,3% e 8,3%. A mortalidade foi 16,6% (um paciente de cada grupo. CONCLUSÃO: O manejo do IB deve ser individualizado. O tratamento da obstrução mediante remoção do cálculo biliar por enterotomia proximal é a escolha inicial para o tratamento do IB. A colecistectomia e a correção da fístula bilioentérica podem ser realizadas juntamente com a remoção do cálculo, no entanto, em pacientes com comorbidades significativas, esses procedimentos devem ser realizados posteriormente.

  6. 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.

  7. Laser Plasmas

    Indian Academy of Sciences (India)

    -focusing in a plasma ... Center for Energy Studies, Indian Institute of Technology, New Delhi 110 016, India; Tata Consultancy Services, Gurgaon, India; Ideal Institute of Technology, Ghaziabad, India; Center for Research in Cognitive, ...

  8. Plasma will…

    Czech Academy of Sciences Publication Activity Database

    Lunov, Oleg

    2016-01-01

    Roč. 174, č. 3 (2016), s. 486-487 ISSN 0007-0963 Institutional support: RVO:68378271 Keywords : plasma * ionized gas Subject RIV: BO - Biophysics OBOR OECD: Biophysics Impact factor: 4.706, year: 2016

  9. Plasma technology

    International Nuclear Information System (INIS)

    Drouet, M.G.

    1984-03-01

    IREQ was contracted by the Canadian Electrical Association to review plasma technology and assess the potential for application of this technology in Canada. A team of experts in the various aspects of this technology was assembled and each team member was asked to contribute to this report on the applications of plasma pertinent to his or her particular field of expertise. The following areas were examined in detail: iron, steel and strategic-metals production; surface treatment by spraying; welding and cutting; chemical processing; drying; and low-temperature treatment. A large market for the penetration of electricity has been identified. To build up confidence in the technology, support should be provided for selected R and D projects, plasma torch demonstrations at full power, and large-scale plasma process testing

  10. Plasma metallization

    International Nuclear Information System (INIS)

    Crowther, J.M.

    1997-09-01

    Many methods are currently used for the production of thin metal films. However, all of these have drawbacks associated with them, for example the need for UHV conditions, high temperatures, exotic metal precursors, or the inability to coat complex shaped objects. Reduction of supported metal salts by non-isothermal plasma treatment does not suffer from these drawbacks. In order to produce and analyse metal films before they become contaminated, a plasma chamber which could be attached directly to a UHV chamber with XPS capability was designed and built. This allowed plasma treatment of supported metal salts and surface analysis by XPS to be performed without exposure of the metal film to the atmosphere. Non-equilibrium plasma treatment of Nylon 66 supported gold(lll) chloride using hydrogen as the feed gas resulted in a 95% pure gold film, the remaining 5% of the film being carbon. If argon or helium were used as the feed gases during plasma treatment the resultant gold films were 100% pure. Some degree of surface contamination of the films due to plasma treatment was observed but was easily removed by argon ion cleaning. Hydrogen plasma reduction of glass supported silver(l) nitrate and palladium(ll) acetate films reveals that this metallization technique is applicable to a wide variety of metal salts and supports, and has also shown the ability of plasma reduction to retain the complex 'fern-like' structures seen for spin coated silver(l) nitrate layers. Some metal salts are susceptible to decomposition by X-rays. The reduction of Nylon 66 supported gold(lll) chloride films by soft X-rays to produce nanoscopic gold particles has been studied. The spontaneous reduction of these X-ray irradiated support gold(lll) chloride films on exposure to the atmosphere to produce gold rich metallic films has also been reported. (author)

  11. 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.

  12. Plasma Diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Zaveryaev, V [Kurchatov Institute, Moscow (Russian Federation); others, and

    2012-09-15

    The success in achieving peaceful fusion power depends on the ability to control a high temperature plasma, which is an object with unique properties, possibly the most complicated object created by humans. Over years of fusion research a new branch of science has been created, namely plasma diagnostics, which involves knowledge of almost all fields of physics, from electromagnetism to nuclear physics, and up-to-date progress in engineering and technology (materials, electronics, mathematical methods of data treatment). Historically, work on controlled fusion started with pulsed systems and accordingly the methods of plasma parameter measurement were first developed for short lived and dense plasmas. Magnetically confined hot plasmas require the creation of special experimental techniques for diagnostics. The diagnostic set is the most scientifically intensive part of a plasma device. During many years of research operation some scientific tasks have been solved while new ones arose. New tasks often require significant changes in the diagnostic system, which is thus a very flexible part of plasma machines. Diagnostic systems are designed to solve several tasks. As an example here are the diagnostic tasks for the International Thermonuclear Experimental Reactor - ITER: (1) Measurements for machine protection and basic control; (2) Measurements for advanced control; (3) Additional measurements for performance evaluation and physics. Every new plasma machine is a further step along the path to the main goal - controlled fusion - and nobody knows in advance what new phenomena will be met on the way. So in the planning of diagnostic construction we should keep in mind further system upgrading to meet possible new scientific and technical challenges. (author)

  13. Desajuste educativo por regiones en Colombia: ¿competencia por salarios o por puestos de trabajo?

    Directory of Open Access Journals (Sweden)

    Castillo Caicedo Maribel

    2007-08-01

    Full Text Available Este trabajo aporta una perspectiva del fenómeno de la sobreeducación,
    entendida como un desajuste por exceso, entre el nivel educativo alcanzado
    por el individuo y el exigido por el puesto de trabajo en el cual se
    desempeña; esto se debe a que existe una demanda laboral estrecha de
    puestos de trabajo para personas calificadas en Colombia. Se analizan las
    contribuciones empíricas existentes y el debate sobre las mismas; se
    examinan las teorías que permiten explicar la existencia de un desajuste
    educativo y se realiza una revisión de la literatura internacional y
    nacional sobre el tema. Adicionalmente, se plantean una serie de hipótesis
    para desarrollar un esquema que permita determinar el comportamiento
    del individuo en el fenómeno de la sobreeducación.

  14. Muerte materna por malaria grave por Plasmodium vivax

    Directory of Open Access Journals (Sweden)

    Nancy Arróspide

    Full Text Available Se presenta el caso de una mujer de 19 años con 29 semanas de gestación, procedente de Llumpe (Ancash con antecedentes de viajes a las localidades de Chanchamayo (Junín y Rinconada (Ancash. Ingresó al Hospital de Chacas (Ancash por presentar mal estado general, deshidratación, dificultad respiratoria, ictericia, sensación de alza térmica y dolor abdominal, tuvo reporte de: hemoparásitos 60% en frotis sanguíneo. Fue transferida al Hospital Ramos Guardia (Huaraz donde presentó mayor dificultad respiratoria, coluria, hematuria, disminución del débito urinario y reporte de Plasmodium (+, luego fue transferida al Hospital Cayetano Heredia (Lima donde ingresó a la Unidad de Cuidados Intensivos (UCI, con evolución a falla multiorgánica, óbito fetal y muerte materna. Se confirmó infección por Plasmodium vivax. Destacamos la importancia de mejorar nuestras capacidades de diagnóstico y manejo para brindar un tratamiento adecuado y oportuno.

  15. Miasis ocular por Oestrus ovis

    Directory of Open Access Journals (Sweden)

    María Beltrán F

    2006-01-01

    Full Text Available Se presentan tres casos de miasis ocular (dos adultos y un niñoprocedentes de zonas ganaderas de la provincia de Huaura,departamento de Lima,que acudieron al Hospital Regional de Huacho por presentar el ojo rojo,fotofobia, edema palpebral y sensación de cuerpo extraño;se extrajeron larvas adheridas al canto interno del ojo,las cuales se recibieron en el Instituto Nacional de Salud y fueron identificadas como Oestrus ovis .

  16. Hipoglucemia inducida por carcinoma adrenal

    Directory of Open Access Journals (Sweden)

    Jimena Soutelo

    2013-08-01

    Full Text Available El carcinoma suprarrenal es una neoplasia maligna infrecuente y de mal pronóstico. La presentación clínica más común es originada por la producción hormonal excesiva, mientras que el desarrollo de hipoglucemia sintomática es excepcional. Presentamos el caso de una mujer de 37 años que ingresó al hospital por síntomas de hipoglucemias graves, hipertensión arterial, hipopotasemia y amenorrea secundaria. En el laboratorio se halló hipoglucemia con insulina inhibida y niveles de andrógenos en rango tumoral. La tomografía computarizada (TC de abdomen y pelvis mostró voluminosa formación heterogénea de aspecto sólido sin plano de clivaje con respecto al parénquima hepático e intenso realce con contraste. Luego de la extirpación de la masa retroperitoneal, evolucionó con valores de glucemia y potasemia normales, estabilizó la presión arterial y recuperó los ciclos menstruales.

  17. La curiosidad por la naturaleza

    Directory of Open Access Journals (Sweden)

    José Vicente Rodríguez

    2016-07-01

    Full Text Available Esta actitud es un instrumento estratégico para estimular procesos de desarrollo realmente sostenibles, donde se aproveche la admiración que nos embarga al conocer y apreciar lo que nos rodea para responsablemente utilizar y conservar nuestros recursos naturales. Con esta reflexión deseo resaltar esa motivación de escudriñar lo desconocido, que fue también la virtud que propició el desarrollo de la personalidad de Francisco José de Caldas y Tenorio, uno de nuestros primeros y connotados sabios colombianos, y en cuyo honor se constituyó la revista de divulgación científica más importante del país, que en estos momentos cumple 76 años de existencia. Caldas tuvo curiosidad por todo lo que existía en su entorno; inicialmente en su natal Popayán, donde se maravilló por lo natural, lo que lo motivó y llevó más allá de su tierra a formar parte de la mayor empresa de exploración científica adelantada en ese entonces en territorio americano: la primera Expedición Botánica al nuevo Reino de Granada, de José Celestino Mutis.

  18. Mortalidad por meningitis por Pasteurella canis. Oportunidades de aprendizaje

    Directory of Open Access Journals (Sweden)

    Ana Rosa Ropero Vera

    2016-01-01

    Full Text Available La meningitis bacteriana es una enfermedad importante de distribución mundial, causa mayor y sustancial de mortalidad y morbilidad en países en desarrollo. La Organización Mundial de la Salud (OMS sostiene que la meningitis es una de las diez afecciones principales del ser humano y debe ser considerada como una emergencia infectológica; por eso es fundamental reconocer que esta enfermedad es causa de muerte en niños de todo el mundo, sin distinción de raza, nivel económico o sociocultural. Se realizó una investigación de caso en menor de 53 días de nacido, que cumplía con los criterios clínicos y de laboratorio compatible con meningitis bacteriana, con el propósito de analizar y fortalecer la toma de decisiones en salud pública por parte de la secretaría local de salud del municipio de Valledupar (Colombia. Entre los hallazgos se encontró antecedentes infecciosos en el menor, coloración de Gram y cultivo de LCR, en el que se identificó cocobacilos Gram negativos, que fueron aislados como agente causal Pasteurella canis. Este estudio pretende sensibilizar a los prestadores de salud para que cuenten con personal altamente capacitado para brindar tratamientos adecuados y prevenir complicaciones en la meningitis bacteriana en niños, y así disminuir la posibilidad de secuelas o muerte, tanto en pacientes con compromiso inmunológico o sin este.

  19. Cold plasmas

    International Nuclear Information System (INIS)

    Franz, G.

    1990-01-01

    This textbook discusses the following topics: Phenomenological description of a direct current glow discharge; the plasma (temperature distribution and measurement, potential variation, electron energy distribution function, charge neutralization, wall potentials, plasma oscillations); Production of charge carriers (ions, electrons, ionization in the cathode zone, negative glowing zone, Faraday dark space, positive column, anode zone, hollow cathode discharges); RF-discharges (charge carrier production, RF-Shields, scattering mechanisms); Sputtering (ion-surface interaction, kinetics, sputtering yield and energy distribution, systems and conditions, film formation and stresses, contamination, bias techniques, multicomponent film deposition, cohesion, magnetrons, triode systems, plasma enhanced chemical vapor deposition); Dry etching (sputter etching, reactive etching, topography, process control, quantitative investigations); Etching mechanisms (etching of Si and SiO 2 with CF 4 , of III/V-compound-semiconductors, combination of isotrope and anisotrope etching methods, surface cleaning); ion beam systems (applications, etching); Dyclotron-resonance-systems (electron cyclotron resonance systems, whistler-sources and 'resonant inductive plasma etching'); Appendix (electron energy distribution functions, Bohm's transition zone, plasma oscillations, scattering cross sections and mean free path, metastable states, Child-Langmuir-Schottky equation, loss mechanisms, charge carrier distribution in the positive column, breakdown at high frequencies, motion in a magnetic field, skin depth of an electric field for a HF-discharge, whistler waves, dispersion relations for plane wave propagation). (orig.) With 138 figs

  20. Plasma heating

    International Nuclear Information System (INIS)

    Wilhelm, R.

    1989-01-01

    Successful plasma heating is essential in present fusion experiments, for the demonstration of DpT burn in future devices and finally for the fusion reactor itself. This paper discusses the common heating systems with respect to their present performance and their applicability to future fusion devices. The comparative discussion is oriented to the various function of heating, which are: - plasma heating to fusion-relevant parameters and to ignition in future machines, -non-inductive, steady-pstate current drive, - plasma profile control, -neutral gas breakdown and plasma build-up. In view of these different functions, the potential of neutral beam injection (NBI) and the various schemes of wave heating (ECRH, LH, ICRH and Alven wave heating) is analyzed in more detail. The analysis includes assessments of the present physical and technical state of these heating methods, and makes suggestions for future developments and about outstanding problems. Specific attention is given to the still critical problem of efficient current drive, especially with respect to further extrapolation towards an economically operating tokamak reactor. Remarks on issues such as reliability, maintenance and economy conclude this comparative overview on plasma heating systems. (author). 43 refs.; 13 figs.; 3 tabs

  1. PLASMA DEVICE

    Science.gov (United States)

    Gow, J.D.; Wilcox, J.M.

    1961-12-26

    A device is designed for producing and confining highenergy plasma from which neutrons are generated in copious quantities. A rotating sheath of electrons is established in a radial electric field and axial magnetic field produced within the device. The electron sheath serves as a strong ionizing medium to gas introdueed thereto and also functions as an extremely effective heating mechanism to the resulting plasma. In addition, improved confinement of the plasma is obtained by ring magnetic mirror fields produced at the ends of the device. Such ring mirror fields are defined by the magnetic field lines at the ends of the device diverging radially outward from the axis of the device and thereafter converging at spatial annular surfaces disposed concentrically thereabout. (AFC)

  2. Mortalidad intrahospitalaria por accidente cerebrovascular

    Directory of Open Access Journals (Sweden)

    Federico Rodríguez Lucci

    2013-08-01

    Full Text Available La mortalidad global por accidente cerebrovascular (ACV ha disminuido en las últimas tres décadas, probablemente debido a un mejor control de los factores de riesgo vascular. La mortalidad hospitalaria por ACV ha sido tradicionalmente estimada entre 6 y 14% en la mayoría de las series comunicadas. Sin embargo, los datos de ensayos clínicos recientes sugieren que esta cifra sería sustancialmente menor. Se revisaron datos de pacientes internados con diagnóstico de ACV del Banco de Datos de Stroke de FLENI y los registros institucionales de mortalidad entre los años 2000 y 2010. Los subtipos de ACV isquémicos se clasificaron según criterios TOAST y los ACV hemorrágicos en hematomas intrapanquimatosos, hemorragias subaracnoideas aneurismáticas, malformaciones arteriovenosas y otros hematomas intraparenquimatosos. Se analizaron 1514 pacientes, 1079 (71% con ACV isquémico (grandes vasos 39%, cardioembólicos 27%, lacunares 9%, etiología indeterminada 14%, otras etiologías 11% y 435 (29% con ACV hemorrágico (intraparenquimatosos 27%, hemorragia subaracnoidea 30%, malformaciones arteriovenosas 25% y otros hematomas espontáneos 18%. Se registraron 38 muertes intrahospitalarias (17 ACV isquémicos y 21 ACV hemorrágicos, representando una mortalidad global del 2.5% (1.7% en ACV isquémicos y 4.8% en ACV hemorrágicos. No se registraron muertes asociadas al uso de fibrinolíticos endovenosos. La mortalidad intrahospitalaria en pacientes con ACV isquémico y hemorrágico en nuestro centro fue baja. El manejo en un centro dedicado a las enfermedades neurológicas y el enfoque multidisciplinario por personal médico y no médico entrenado en el cuidado de la enfermedad cerebrovascular podrían explicar, al menos en parte, estos resultados.

  3. Plasma properties

    International Nuclear Information System (INIS)

    Weitzner, H.

    1989-08-01

    A cursory examination of the research activities of the Magneto-Fluid Dynamics Division for the calendar year 1988 shows the effects of the gradual transformation of the group. Although our principal activity, fusion plasma physics research, is unchanged, the work shows closer ties to problems relevant to present experiments than previously. Most notable is the concentrated effort on tokamak equilibrium and transport. We are exploring the implication of turbulence induced transport, resistive MHD effects, neoclassical transport, and possible interpretations of transport based on classical phenomena. In addition, one of our members has chosen to focus on problems of enhanced statistical methods for interpretation of experiments. All of this activity preceded the Tokamak Transport Initiative and reflects our active involvement and concern with the world-wide tokamak program. Since equilibrium and transport are by no means the only theoretical plasma physics problems affecting fusion devices we continue substantial efforts in wave propagation and heating, particle simulation of plasmas, stability theory, enhancement of numerical algorithms, and general plasma physics. We are attempting to develop effective numerical schemes for the Boltzmann equation, adaptive grid methods for MHD, and particle simulation of boundary and antenna effects. Many of these topics reflect our continuing concern to maintain a modest effort in the development of theoretical models and tools for problems of real significance to fusion, but not necessarily of immediate highest priority. We select problems which we expect to become extremely important in the future. Our space plasma physics activities, funded by agencies other than DOE, transfers knowledge learned in fusion plasma physics to another area and conversely stimulates work also relevant to fusion problems

  4. Electron plasma waves and plasma resonances

    International Nuclear Information System (INIS)

    Franklin, R N; Braithwaite, N St J

    2009-01-01

    In 1929 Tonks and Langmuir predicted of the existence of electron plasma waves in an infinite, uniform plasma. The more realistic laboratory environment of non-uniform and bounded plasmas frustrated early experiments. Meanwhile Landau predicted that electron plasma waves in a uniform collisionless plasma would appear to be damped. Subsequent experimental work verified this and revealed the curious phenomenon of plasma wave echoes. Electron plasma wave theory, extended to finite plasmas, has been confirmed by various experiments. Nonlinear phenomena, such as particle trapping, emerge at large amplitude. The use of electron plasma waves to determine electron density and electron temperature has not proved as convenient as other methods.

  5. ''Dusty plasmas''

    International Nuclear Information System (INIS)

    Tsytovich, V.N.; Bingham, R.; Angelis, U. de

    1989-09-01

    The field of ''dusty plasmas'' promises to be a very rewarding topic of research for the next decade or so, not only from the academic point of view where the emphasis is on developing the theory of the often complex collective and non-linear processes, but also from the point of view of applications in astrophysics, space physics, environmental and energy research. In this ''comment'' we should like to sketch the current development of this fast growing and potentially very important research area. We will discuss the new features of ''dusty'' plasmas in the most general terms and then briefly mention some successful applications and effects which have already been examined. (author)

  6. Herida precordial por arma blanca

    OpenAIRE

    Marcelo F. Jiménez; Nuria Novoa; José Luis Aranda; Gonzalo Varela

    2005-01-01

    Varón de 42 años con esquizofrenia paranoide. Intento de suicidio con tres autolesiones por arma blanca (Fig. 1). Fue traído al hospital en estado consciente, taquicárdico, taquipneico y con tensión arterial (TA) de 140/90 mmHg. Fue trasladado al quirófano, donde se practicó una toracotomía axilar izquierda sin extraer el arma. Durante la intervención se apreciaron tres heridas incisas, dos no penetrantes, hemotórax de 150 ml, herida pericárdica de 4 cm, sin lesiones cardíacas. La hoja del ar...

  7. Plasma physics and engineering

    CERN Document Server

    Fridman, Alexander

    2011-01-01

    Part I: Fundamentals of Plasma Physics and Plasma ChemistryPlasma in Nature, in the Laboratory, and in IndustryOccurrence of Plasma: Natural and Man MadeGas DischargesPlasma Applications, Plasmas in IndustryPlasma Applications for Environmental ControlPlasma Applications in Energy ConversionPlasma Application for Material ProcessingBreakthrough Plasma Applications in Modern TechnologyElementary Processes of Charged Species in PlasmaElementary Charged Particles in Plasma and Their Elastic and Inelastic CollisionsIonization ProcessesMechanisms of Electron Losses: The Electron-Ion RecombinationEl

  8. Contribuições do programa bolsa alfabetização na formação inicial do professor: o que evidenciam os relatos reflexivos produzidos por alunos de pedagogia

    Directory of Open Access Journals (Sweden)

    Ana Silvia Moço Aparicio

    2017-02-01

    Full Text Available No presente artigo, apresentamos e discutimos os resultados de uma pesquisa em que buscamos compreender o processo de formação docente de alunos de Pedagogia participantes do Programa Bolsa Alfabetização, implantado pelo governo do Estado de São Paulo. Como objeto de análise foram considerados os relatos reflexivos produzidos por esses alunos, a partir de suas observações e intervenções realizadas na sala de aula de alfabetização em que atuavam junto ao professor regente. Para as análises, adotamos como referenciais teórico-metodológicos as contribuições do Interacionismo Sociodiscursivo. Os resultados apontam que a inserção dos licenciandos no cotidiano da sala de aula, ao propiciar a familiarização desse futuro professor com o processo de ensino e aprendizagem na alfabetização nas diferentes situações didáticas que emergem nesse contexto, contribuem para a reconstrução do foco de observação pelos licenciandos e para a reelaboração de suas crenças e concepções de ensino e aprendizagem.

  9. 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...

  10. Burning plasmas

    International Nuclear Information System (INIS)

    Furth, H.P.; Goldston, R.J.; Zweben, S.J.

    1990-10-01

    The fraction of fusion-reaction energy that is released in energetic charged ions, such as the alpha particles of the D-T reaction, can be thermalized within the reacting plasma and used to maintain its temperature. This mechanism facilitates the achievement of very high energy-multiplication factors Q, but also raises a number of new issues of confinement physics. To ensure satisfactory reaction operation, three areas of energetic-ion interaction need to be addressed: single-ion transport in imperfectly symmetric magnetic fields or turbulent background plasmas; energetic-ion-driven (or stabilized) collective phenomena; and fusion-heat-driven collective phenomena. The first of these topics is already being explored in a number of tokamak experiments, and the second will begin to be addressed in the D-T-burning phase of TFTR and JET. Exploration of the third topic calls for high-Q operation, which is a goal of proposed next-generation plasma-burning projects. Planning for future experiments must take into consideration the full range of plasma-physics and engineering R ampersand D areas that need to be addressed on the way to a fusion power demonstration

  11. Plasma treatment for influence of cold in different phases of formation of calcium phosphate on the surface of nanocomposite Al{sub 2}O{sub 3}/ZrO{sub 2}; Influencia do tratamento por plasma a frio na formacao de diferentes fases de fosfatos de calcio sobre a superficie do nanocomposito de Al{sub 2}O{sub 3}/ZrO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Santos, K.H.; Ferreira, J.A.; Osiro, D.; Nascimento, L.I.S.; Pallone, E.M.J.A., E-mail: katiahsantos@usp.br [Universidade de Sao Paulo (FZEA/USP), Pirassununga, SP (Brazil). Faculdade de Zootecnia e Engenharia de Alimentos; Colnago, L.B. [Embrapa Instrumentacao, Sao Carlos, SP (Brazil); Alves Junior, C. [Universidade Federal Rural do Semi-Arido (UFERSA),Mossoro, RN (Brazil)

    2016-07-01

    Among the different techniques used in surface treatment of biomaterials, the plasma has been noted for its ability to promote changes in surface roughness of the treated material. The objective of this study was to evaluate the influence of treatment by plasma in the formation of calcium phosphate nanocomposite on the surface of Al2O3/ZrO2 (5% by vol.). For this, samples were formed, calcined, sintered, surface treated and coated biomimeticamente plasma for 14 days. The surface characterization was performed by confocal microscopy and spectroscopy, Fourier transform infrared (FTIR). After coating, the samples were characterized by FTIR and X-ray diffraction X-ray (XRD). It was observed that the treatments improved surface roughness. Furthermore, regardless of the surface treatment were observed only three phases of calcium phosphates: HA α -TCP and -β-TCP. It is worth noting that depending on the composition, there are variations in the amount of phosphates, as well as the percentages of the different phases. (author)

  12. Impacto do Programa Água para Todos (PAT sobre a morbi-mortalidade por diarreia em crianças do Estado da Bahia, Brasil Impacto del Programa Agua para Todos (PAT sobre la morbimortalidad por diarrea en niños del Estado de Bahía, Brasil Impact of the Water for All Program (PAT on childhood morbidity and mortality from diarrhea in the Bahia State, Brazil

    Directory of Open Access Journals (Sweden)

    Davide Rasella

    2013-01-01

    Full Text Available O objetivo do presente estudo foi avaliar o impacto do Programa Água para Todos (PAT, implantado no Estado da Bahia, Brasil, por ampliar a cobertura do saneamento básico em áreas de maior vulnerabilidade. Foram selecionados 224 municípios com informações vitais adequadas. Foi utilizado um desenho de estudo antes-e-depois controlado, efetuando uma análise de regressão multivariada para dados em painel com resposta binomial negativa a efeitos fixos do ano 2005 até 2008. A cobertura do PAT, como variável contínua, esteve associada negativamente (p El objetivo del presente estudio fue evaluar el impacto del Programa Agua para Todos (PAT, implantado en el Estado de Bahía, Brasil, para ampliar la cobertura del saneamiento básico en áreas de mayor vulnerabilidad. Fueron seleccionados 224 municipios con información vital adecuada. Se utilizó un diseño de estudio antes-después controlado, efectuando un análisis de regresión multivariada para los datos en panel con respuesta binomial negativa, a efectos fijos del año 2005 hasta el 2008. La cobertura del PAT, como variable continua, estuvo asociada negativamente (p This study aimed to evaluate the impact of the Water for All Program (PAT, launched in Bahia State, Brazil, with the objective of expanding coverage of the water supply and sanitation in areas with high vulnerability to waterborne diseases. A total of 224 municipalities (counties with adequate vital statistics were selected. A controlled before-and-after study design was used, performing analyses with multivariate negative binomial regression with fixed effects, from 2005 to 2008. PAT coverage - as a continuous variable - was negatively associated (p < 0.01 with the under-five mortality rate. Municipalities with coverage ≥ 10% showed a reduction of 39% (p < 0.05 in mortality from diarrhea, under-five mortality of 14% (p < 0.01, and hospitalizations from diarrhea of 6% (p < 0.05 when compared to municipalities without PAT

  13. Miotoxicidade por organofosforados Organophosphate myotoxicity

    Directory of Open Access Journals (Sweden)

    Maria J. Cavaliere

    1996-06-01

    Full Text Available Os organofosforados são um grupo de compostos químicos amplamente utilizados em agropecuária como inseticidas, ocasionando intoxicações acidentais em animais e humanos, e mesmo sendo utilizados em tentativas de suicídio. A toxicidade desses produtos decorre sobretudo de insuficiência cárdio-respiratória por compromentimento do sistema nervoso autônomo. Sabe-se que alguns destes compostos induzem em animais de experimentação e em humanos, uma miopatia caracterizada por degeneração de células musculares, comprometendo sobretudo a musculatura respiratória. Baseado no fato de que este comprometimento contribui para a piora da função respiratória, propõe-se um protocolo de avaliação rotineira de miotoxicidade por compostos organofosforados, através de uma bateria mínima e suficiente de colorações e reações histoquímicas para quantificação da necrose muscular. Utilizaram-se como modelo experimental, grupos de ratos albinos (Wistar intoxicados com o organofosforado paraoxon, com e sem antídotos (atropina ou pralidoxima. Verificou-se nos grupos tratados com paraoxon e paraoxon mais atropina, necrose de fibras musculares no diafragma, que atingia em determinadas áreas até 15% das fibras. No grupo tratado com paraoxon mais pralidoxima, a necrose foi mínima, evidenciando o papel mioprotetor deste último antídoto.Organophosphates comprise a group of chemical compounds extensively used in farming as insecticides, which cause accidental poisoning in animals and men and are also used in suicide attempts. The toxicity of these compounds is due especially to the cardiac and respiratory impairment in consequence of autonomic nervous system disorders. However, it is known that some of these products induce a myopathy in experimental animals and humans. This myopathy is characterized by muscle cell degeneration, involving above all the respiratory muscles. Based on the fact that this involvement certainly enhances the

  14. Suppression of cytochrome P450 reductase (POR) expression in hepatoma cells replicates the hepatic lipidosis observed in hepatic POR-null mice.

    Science.gov (United States)

    Porter, Todd D; Banerjee, Subhashis; Stolarczyk, Elzbieta I; Zou, Ling

    2011-06-01

    Cytochrome P450 reductase (POR) is a microsomal electron transport protein essential to cytochrome P450-mediated drug metabolism and sterol and bile acid synthesis. The conditional deletion of hepatic POR gene expression in mice results in a marked decrease in plasma cholesterol levels counterbalanced by the accumulation of triglycerides in lipid droplets in hepatocytes. To evaluate the role of cholesterol and bile acid synthesis in this hepatic lipidosis, as well as the possible role of lipid transport from peripheral tissues, we developed a stable, small interfering RNA (siRNA)-mediated cell culture model for the suppression of POR. POR mRNA and protein expression were decreased by greater than 50% in McArdle-RH7777 rat hepatoma cells 10 days after transfection with a POR-siRNA expression plasmid, and POR expression was nearly completely extinguished by day 20. Immunofluorescent analysis revealed a marked accumulation of lipid droplets in cells by day 15, accompanied by a nearly 2-fold increase in cellular triglyceride content, replicating the lipidosis seen in hepatic POR-null mouse liver. In contrast, suppression of CYP51A1 (lanosterol demethylase) did not result in lipid accumulation, indicating that loss of cholesterol synthesis is not the basis for this lipidosis. Indeed, addition of cholesterol to the medium appeared to augment the lipidosis in POR-suppressed cells, whereas removal of lipids from the medium reversed the lipidosis. Oxysterols did not accumulate in POR-suppressed cells, discounting a role for liver X receptor in stimulating triglyceride synthesis, but addition of chenodeoxycholate significantly repressed lipid accumulation, suggesting that the absence of bile acids and loss of farnesoid X receptor stimulation lead to excessive triglyceride synthesis.

  15. Magnetoresistive waves in plasmas

    International Nuclear Information System (INIS)

    Felber, F.S.; Hunter, R.O. Jr.; Pereira, N.R.; Tajima, T.

    1982-01-01

    The self-generated magnetic field of a current diffusing into a plasma between conductors can magnetically insulate the plasma. Propagation of magnetoresistive waves in plasmas is analyzed. Applications to plasma opening switches are discussed

  16. Herida precordial por arma blanca

    Directory of Open Access Journals (Sweden)

    Marcelo F. Jiménez

    2005-04-01

    Full Text Available Varón de 42 años con esquizofrenia paranoide. Intento de suicidio con tres autolesiones por arma blanca (Fig. 1. Fue traído al hospital en estado consciente, taquicárdico, taquipneico y con tensión arterial (TA de 140/90 mmHg. Fue trasladado al quirófano, donde se practicó una toracotomía axilar izquierda sin extraer el arma. Durante la intervención se apreciaron tres heridas incisas, dos no penetrantes, hemotórax de 150 ml, herida pericárdica de 4 cm, sin lesiones cardíacas. La hoja del arma blanca penetraba a través del diafragma produciendo una herida incisa en el lóbulo hepático izquierdo (Fig. 2. Se extrajo el arma y se suturó la laceración hepática. El paciente fue trasladado el cuarto día a la Unidad de Psiquiatría.

  17. Osteomalacia inducida por tumor: hemangiopericitoma rinosinusal

    Directory of Open Access Journals (Sweden)

    Enriqueta M. Serafini

    2013-02-01

    Full Text Available La osteomalacia inducida por tumor es una rara enfermedad del metabolismo óseo caracterizada por el aumento en la excreción de fosfato a nivel renal seguido de hipofosfatemia. Es causada por agentes fosfatúricos producidos por determinados tumores. La resección total del tumor resulta en la completa reversión de las anormalidades bioquímicas, la desaparición de las manifestaciones clínicas y los hallazgos en los estudios por imágenes. Presentamos el caso de un varón de 61 años con cuadro clínico y laboratorio compatibles con osteomalacia oncogénica inducida por tumor mesenquimático de localización rinosinusal. En nuestro caso el diagnóstico histológico correspondió a una neoplasia de tipo vascular: hemangiopericitoma.

  18. Plasma physics

    CERN Document Server

    Cairns, R A

    1985-01-01

    This book is intended as an introduction to plasma physics at a level suitable for advanced undergraduates or beginning postgraduate students in physics, applied mathematics or astrophysics. The main prerequisite is a knowledge of electromagnetism and of the associated mathematics of vector calculus. SI units are used throughout. There is still a tendency amongst some plasma physics researchers to· cling to C.g.S. units, but it is the author's view that universal adoption of SI units, which have been the internationally agreed standard since 1960, is to be encouraged. After a short introductory chapter, the basic properties of a plasma con­ cerning particle orbits, fluid theory, Coulomb collisions and waves are set out in Chapters 2-5, with illustrations drawn from problems in nuclear fusion research and space physics. The emphasis is on the essential physics involved and (he theoretical and mathematical approach has been kept as simple and intuitive as possible. An attempt has been made to draw attention t...

  19. Casipoemas por Navidad : (1969-2010)

    OpenAIRE

    Sena Medina, Guillermo

    2011-01-01

    PRESENTACIÓN AL AIRE DE LA POESÍA RELIGIOSA Y NAVIDEÑA DE GUILLERMO SENA MEDINA Constituye un gran honor hacer la presentación de Guillermo Sena Medina por un doble motivo; por la larga y sincera amistad que nos une desde hace muchos años al socaire de nuestra común afición por la Historia, como cronistas oficiales de nuestros municipios; y, sobre todo y particularmente, por su rica y profunda personalidad como hombre de letras, nacida de su aún más rica y profunda personalidad humana. A...

  20. Plasma shutdown device

    International Nuclear Information System (INIS)

    Hosogane, Nobuyuki; Nakayama, Takahide.

    1985-01-01

    Purpose: To prevent concentration of plasma currents to the plasma center upon plasma shutdown in a torus type thermonuclear device by the injection of fuels to the plasma center thereby prevent plasma disruption at the plasma center. Constitution: The plasma shutdown device comprises a plasma current measuring device that measures the current distribution of plasmas confined within a vacuum vessel and outputs a control signal for cooling the plasma center when the plasma currents concentrate to the plasma center and a fuel supply device that supplies fuels to the plasma center for cooling the center. The fuels are injected in the form of pellets into the plasmas. The direction and the velocity of the injection are set such that the pellets are ionized at the center of the plasmas. (Horiuchi, T.)

  1. Estudo de acurácia em cirurgia assistida por navegação na revisão cirúrgica de deformidade vertebral Estudio de la precisión en cirugía asistida por navegación en la reoperación de deformidad espinal Study of the accuracy of navigation-assisted surgery in the surgical revision of spinal deformity

    Directory of Open Access Journals (Sweden)

    Chárbel Jacob Junior

    2011-01-01

    Full Text Available OBJETIVO: Avaliar as vantagens da cirurgia com navegação na revisão cirúrgica de deformidades vertebrais, verificando a acurácia deste método. MÉTODO: Foram revisados cincos pacientes com deformidades vertebrais que tiveram intercorrências na primeira cirurgia. Esses pacientes foram submetidos a um estudo de tomografia computadorizada (TC com cortes de 2mm da coluna vertebral antes da segunda cirurgia. Nos cinco pacientes submetidos a reabordagem cirúrgica procedeu-se a instrumentação posterior com auxílio da navegação. Foram 84 parafusos pediculares implantados, sendo que 33 destes parafusos foram assistidos por computação. A navegação foi empregada nos níveis da deformidade vertebral onde a anatomia apresentava-se alterada inviabilizando o correto uso dos parâmetros anatômicos para inserção de parafusos pediculares. Nos demais níveis onde era possível a correta identificação desses parâmetros anatômicos foi utilizada a técnica padrão. A TC pós-operatória foi realizada para aferição do posicionamento dos parafusos pediculares. Avaliamos os resultados obtidos no posicionamento com e sem o uso da navegação. O tempo de fluoroscopia e o tempo da cirurgia também foram comparados com o padrão ouro da literatura. RESULTADOS: Dos 33 parafusos implantados com navegação observou-se uma acurácia de 94%, com uma taxa de violação pedicular de 6%. CONCLUSÕES: O uso da navegação é importante nas revisões cirúrgicas das deformidades vertebrais com anatomia alterada, influenciando no bom resultado final da cirurgia.OBJETIVO: Evaluar las ventajas de la cirugía con navegación en reoperación por deformidades vertebrales, verificando la precisión de este método. MÉTODO: Fueron revisados cinco pacientes con deformidades vertebrales que tuvieron complicaciones en la primera cirugía. Esos pacientes fueron sometidos a un estudio de tomografía computada (TC con cortes de 2 mm de la columna vertebral antes de la

  2. Hematoquecia letal por angiostrongilosis abdominal

    Directory of Open Access Journals (Sweden)

    Gerzain Rodríguez

    2000-06-01

    Full Text Available Una niña indigena de 4 años de edad, procedente de Carurú, Vaupés, un municipio semiselvático de 2.000 habitantes, presentó hematoquecia repetida con sincope y muerte 4 días después, a pesar de recibir transfusiones sanguíneas. El estudio postmortem descubrió dos masas de 3-4 cm de diámetro en el ileon distal que, al microscopio, correspondieron a inflamación severa de toda la pared intestinal, rica en eosinofilos y en granulomas con células gigantes que circunscribian y fagocitaban huevos y larvas de Angiostrongylus costaricensis, helminto situado también dentro de las arterias de la submucosa, vasos que presentaban engrosamiento de la intima y focos con inflamación granulomatosa con eosinófilos. La niña no presentó leucocitosis ni eosinofilia. Este es el segundo caso de angiostrongilosis de esta región. El primero fue el de una mujer indigena de 34 años también con hematoquecia anemizante. La angiostrongilosis abdominal se diagnosticó por primera vez en Colombia en 1979, en un niño de 5 años, de Dagua, Valle. La niña aquí presentada es el sexto paciente con esta entidad en Colombia. La hematoquecia como manifestación predominante de la angiostrongilosis es extraordinaria para una enfermedad parasitaria; se ha registrado solamente en tres ocasiones anteriores. La abundancia de cristales de Charcot-Leyden, que se tiñen muy bien con la coloración de Ziehl-Neelsen o de Fite-Faraco, en los infiltrados de la pared intestinal. sugiere que su búsqueda en las heces puede ser una ayuda en el diagnóstico de casos sospechosos. pues, los huevos y las larvas no se eliminan en las heces y el diagnóstico definitivo de la angiostrongilosis es histopatológico. Revisamos las caracteristicas clinicas, parasitológicas e histopatológicas de esta parasitosis que será más prevalente en Colombia a medida que los médicos. especialmente los patólogos, la conozcan mejor.

  3. Encefalopatía por priones

    Directory of Open Access Journals (Sweden)

    Carlos Colegial

    1999-01-01

    Full Text Available Las encefalopatías espongiformes por priones son enfermedades neurodegenerativas que pueden ser esporádicas o transmisibles, ya sea por mecanismos infecciosos o hereditarios. Su investigación ha planteado enormes retos y en el recorrido histórico en busca de su causa dos médicos han recibido el premio Nobel de Medicina: Carleton Gajdusek, por sus trabajos en Nueva Guinea donde describió la transmisión infecciosa por ritos canibalísticos, que llevó a estudios de transmisión experimental en chimpancés y a su teoría de los "virus lentos" (por el largo período de incubación de la enfermedad.

  4. Portable exhauster POR-007/Skid E and POR-008/Skid F storage plan

    International Nuclear Information System (INIS)

    Nelson, O.D.

    1998-01-01

    This document provides storage requirements for 1,000 CFM portable exhausters POR-O07/Skid E and POR-008/Skid F. These requirements are presented in three parts: preparation for storage, storage maintenance and testing, and retrieval from storage. The exhauster component identification numbers listed in this document contain the prefix POR-007 or POR-008 depending on which exhauster is being used

  5. Weathering resistance of thin plasma polymer films on pre-coated steel =

    Science.gov (United States)

    Serra, Ricardo Gil Henriques

    O trabalho apresentado teve origem no projecto de investigacao “Tailored Thin Plasma Polymers Films for Surface Engineering of Coil Coated Steel”, financiado pelo Programa Europeu ECSC Steel Research. Sistemas de aco galvanizado pre-pintado em banda a base de poliester e poliuretano foram submetidos a um processo de polimerizacao por plasma onde um filme fino foi depositado de modo a modificar as propriedades de superficie. Foram usados reactores de catodo oco, microondas e radio frequencia para a deposicao do polimero fino. Os sistemas preparados foram analisados de modo a verificar a influencia do processo de polimerizacao por plasma na alteracao das propriedades barreira dos sistemas pre-pintados em banda. Foi estudado o efeito dos diferentes passos do processo de polimerizacao por plasma, bem como o efeito de diferentes variaveis operatorias. A mistura precursora foi variada de modo a modificar as propriedades da superficie de modo a poder vir a obter maior hidrofobicidade, maior resistencia a marcas digitais, bem como maior facilidade de limpeza. Os testes foram conduzidos em solucao de NaCl 0,5 M. Para o trabalho foram usadas tecnicas de analise da morfologia da superficie como Microscopia de Forca Atomica e Microscopia Electronica de Varrimento. As propriedades electroquimicas dos sistemas foram estudadas por Espectroscopia de Impedancia Electroquimica. A estrutura dos filmes gerados no processo de polimerizacao por plasma foi caracterizada por Microscopia de Transmissao Electronica. A modificacao das propriedades opticas devido ao processo de polimerizacao por plasma foi tambem obtida.

  6. Farmacocinética poblacional de lopinavir y ritonavir en pacientes adultos infectados por el VIH

    OpenAIRE

    Moltó Marhuenda, José

    2008-01-01

    Descripció del recurs: 25 gener 2011 Objetivos: 1.- Determinar la variabilidad interindividual de la concentración valle en plasma de los fármacos inhibidores de la transcriptasa inversa no análogos de los nucleósidos (ITINAN) y de los inhibidores de la proteasa (IP) del virus de la inmunodeficiencia humana (VIH), así como la proporción de pacientes infectados por el VIH en tratamiento antirretroviral con concentraciones valle de los fármacos por debajo de la concentración mínima eficaz en...

  7. Desarrollo y evaluación de técnicas espectrocópicas basadas en plasmas inducidos por láser y en descargas luminiscentes estimuladas con campos magnéticos para el análisis directo de sólidos

    OpenAIRE

    Vega Reguilón, Paola

    2016-01-01

    El gran desarrollo de nuevos materiales impulsa la investigación en las técnicas de análisis directo de sólidos, en particular de aquellas que permiten obtener información sobre la distribución espacial de la composición elemental de un material (tanto en superficie como en profundidad), información que quedaría destruida si la muestra fuese disuelta. Una de estas técnicas es la descarga luminiscente generada mediante radiofrecuencia (rf-GD) que consiste en un plasma a baja presión que acopl...

  8. Plasma focus breeder

    International Nuclear Information System (INIS)

    Ikuta, Kazunari.

    1981-09-01

    Instead of using linear accelerators, it is possible to breed fissile fuels with the help of high current plasma focus device. A mechanism of accelerating proton beam in plasma focus device to high energy would be a change of inductance in plasma column because of rapid growth of plasma instability. A possible scheme of plasma focus breeder is also proposed. (author)

  9. Desfibrilador automático implantado en pacientes con miocardiopatía hipertrófica: criterios de selección, evolución y predictores de terapia apropiada Automatic defibrillator implanted in patients with hypertrophic myocardiopathy: selection criteria, evolution and appropriate therapy predictors

    Directory of Open Access Journals (Sweden)

    Guillermo Mora

    Full Text Available Introducción y objetivos: la miocardiopatía hipertrófica es una enfermedad de origen genético con prevalencia de 1% al 2%. La mitad de los pacientes fallecen por muerte súbita cardiaca, la mayoría por arritmias ventriculares. Todavía no está claro a qué pacientes se les debe implantar un desfibrilador automático. El objetivo de este trabajo es describir una serie de pacientes con implante, los criterios empleados y los resultados obtenidos, así como analizar los predictores de terapia apropiada por el desfibrilador. Métodos: se incluyeron 20 pacientes que recibieron un desfibrilador de tercera generación. En todos se realizó estudio electrofisiológico y seguimiento prospectivo con registro de eventos. En 18 (90% se hizo estudio genético. Resultados: el 55% eran hombres con edad promedio de 40 [11-78] años. Seis (30% recibieron implantante por prevención secundaria y 14 (70% por prevención primaria; los últimos por presentar varios factores de riesgo. Se indujo una arritmia sostenida en 15 (75% y en 3 (15% taquicardia ventricular monomórfica sostenida. A 22 meses de seguimiento 4 (20% sufrieron terapia apropiada y 2 (10% fallecieron. La taquicardia ventricular monomórfica clínica (p=0,03 y la inducida (pIntroduction and objectives: hypertrophic myocardiopathy is a genetic entity with 1% to 2% prevalence. Half patients die of sudden cardiac death, most due to ventricular arrhythmias. There is still no clarity with regard to the patients to whom an automatic defibrillator has to be implanted. The objective of this work is to describe a series of patients with implant, the criteria used and the results obtained, as well as to analyze the predictors of appropriate therapy with the defibrillator. Methods: 20 patients that received a third generation defibrillator were included. Electrophysiological study and prospective follow-up with register of events was performed in all. Genetic study was done in 18 (90%. Results: 55% were

  10. Verdad por definición

    OpenAIRE

    Garrido Garrido, Julián

    1997-01-01

    Not available.La verdad por definición es un tipo peculiar de verdad científica, distinguible de las verdades lógicas, matemáticas y empíricas. La definición, por su parte, designa diversos procedimientos de asignación de significado, cuyas diferencias exigen una adjetivación cuidadosa: definiciones ostensivas y operacionales, definiciones de diccionario y definiciones teóricas. Pero sólo las del último tipo son verdaderas por definición. En el presente artículo se precisa el concepto formal ...

  11. Síndrome de Munchausen por mandato

    OpenAIRE

    Esteban, Miguel A.; Pérez, Miriam R.; Bracco, Anahí

    2006-01-01

    El Síndrome de Munchausen por mandato, "un trastorno ficticio, por el cual la enfermedad del niño es inducida, promovida o provocada por la persona más próxima a él, generalmente su madre", es todavía mal conocido y su génesis imperfectamente comprendida. Esta comunicación está destinada a esclarecer al pediatra esta patología, con elevada morbilidad y secuelas, como así también de altísima mo...

  12. Plasma Free Metanephrines

    Science.gov (United States)

    ... Links Patient Resources For Health Professionals Subscribe Search Plasma Free Metanephrines Send Us Your Feedback Choose Topic ... Images View Sources Ask Us Also Known As Plasma Metanephrines Formal Name Fractionated Plasma Free Metanephrines (Metanephrine ...

  13. Improved plasma accelerator

    Science.gov (United States)

    Cheng, D. Y.

    1971-01-01

    Converging, coaxial accelerator electrode configuration operates in vacuum as plasma gun. Plasma forms by periodic injections of high pressure gas that is ionized by electrical discharges. Deflagration mode of discharge provides acceleration, and converging contours of plasma gun provide focusing.

  14. La pintura vista por un pintor joven

    Directory of Open Access Journals (Sweden)

    Fuentes Pozo, Pedro

    2000-01-01

    Full Text Available Not available

    El pintor se define a lo largo del tiempo como un artista en mutación influenciado por la sociedad de su momento y por su propio mundo interior Esto ha contribuido a la creación de distintos estilos pictóricos y a una evolución que conlleva la despreocupación por el aspecto formal en aras de una introspección al mundo interior En el cambio constante se refleja la búsqueda del artista que valida la intemporalidad del arte. Así, el verdadero artista sobrevive al aplauso o rechazo de la crítica, convirtiéndose en un verdadero hombre renancentista preocupado por el hallazgo del conocimiento universal.

  15. 14 Nobel, preocupados por el CERN

    CERN Multimedia

    Rivera, A

    2003-01-01

    "E l presidente del Consejo del CERN (Laboratorio Europeo de Fisica de Particulas, junto a Ginebra), Maurice Bourquin, ha recibido una carta firmada por un grupo de cientificos muy especiales: 14 premios Nobel de Fisica" (1 page).

  16. ECR plasma photographs as a plasma diagnostic

    Energy Technology Data Exchange (ETDEWEB)

    Racz, R; Biri, S; Palinkas, J [Institute of Nuclear Research (ATOMKI), H-4026 Debrecen, Bem ter 18/c (Hungary)

    2011-04-15

    Low, medium or highly charged ions delivered by electron cyclotron resonance (ECR) ion sources all are produced in the ECR plasma. In order to study such plasmas, high-resolution visible light plasma photographs were taken at the ATOMKI ECR ion source. An 8 megapixel digital camera was used to photograph plasmas made from He, methane, N, O, Ne, Ar, Kr, Xe gases and from their mixtures. The analysis of the photo series gave many qualitative and some valuable physical information on the nature of ECR plasmas. A comparison was made between the plasma photos and computer simulations, and conclusions were drawn regarding the cold electron component of the plasma. The warm electron component of similar simulation was compared with x-ray photos emitted by plasma ions. While the simulations are in good agreement with the photos, a significant difference was found between the spatial distribution of the cold and warm electrons.

  17. Plasma physics and fusion plasma electrodynamics

    CERN Document Server

    Bers, Abraham

    2016-01-01

    Plasma is a ubiquitous state of matter at high temperatures. The electrodynamics of plasmas encompasses a large number of applications, from understanding plasmas in space and the stars, to their use in processing semiconductors, and their role in controlled energy generation by nuclear fusion. This book covers collective and single particle dynamics of plasmas for fully ionized as well as partially ionized plasmas. Many aspects of plasma physics in current fusion energy generation research are addressed both in magnetic and inertial confinement plasmas. Linear and nonlinear dynamics in hydrodynamic and kinetic descriptions are offered, making both simple and complex aspects of the subject available in nearly every chapter. The approach of dividing the basic aspects of plasma physics as "linear, hydrodynamic descriptions" to be covered first because they are "easier", and postponing the "nonlinear and kinetic descriptions" for later because they are "difficult" is abandoned in this book. For teaching purpose...

  18. Plasma waves in an inhomogeneous cylindrical plasma

    International Nuclear Information System (INIS)

    Pesic, S.S.

    1976-01-01

    The complete dispersion equation governing small amplitude plasma waves propagating in an inhomogeneous cylindrical plasma confined by a helical magnetic field is solved numerically. The efficiency of the wave energy thermalization in the lower hybrid frequency range is studied

  19. Micetoma por Nocardia brasiliensis: reporte de caso

    Directory of Open Access Journals (Sweden)

    Miriam Guevara R

    2003-07-01

    Full Text Available Se presenta el caso de un paciente peruano, agricultor, con una infección cutánea de origen traumático causada por Nocardia brasiliensis, que evolucionó hacia la amputación del miembro inferior afectado. El diagnóstico se realizó por examen directo y cultivo del espécimen.

  20. Quiescent plasma machine for plasma investigation

    International Nuclear Information System (INIS)

    Ferreira, J.L.

    1993-01-01

    A large volume quiescent plasma device is being developed at INPE to study Langmuir waves and turbulence generated by electron beams (E b ≤ 500 e V) interacting with plasma. This new quiescent plasma machine was designed to allow the performance of several experiments specially those related with laboratory space plasma simulation experiments. Current-driven instabilities and related phenomena such as double-layers along magnetic field lines are some of the many experiments planned for this machine. (author)

  1. Plasma basic concepts and nitrogen containing plasmas

    OpenAIRE

    Sanz Lluch, M. del Mar; Tanarro, Isabel

    2007-01-01

    Basic concepts related to plasmas are described as well as the typical characterization methods currently available. A brief overview about some plasma applications is given, but focusing on plasma used in material processing mainly devoted to the microelectronics industry. Finally, specific applications related to plasma-assisted MBE for nitrides and dilute nitrides are given, showing some interesting research works performed to that purpose, and giving the usual characterization techniques ...

  2. Tatuaje por amalgama. Reporte de un caso

    Directory of Open Access Journals (Sweden)

    Luis Fang Mercado

    2012-01-01

    Full Text Available El tatuaje por amalgama se origina por el depósito en el tejido conectivo subepitelial de fragmentos de amalgama resultado de procedimientos iatrogénicos por parte del operador. La profundidad a la que se encuentren albergados los residuos de este material influye en la presentación clínica de las lesiones. Radiográficamente se pueden identificar los fragmentos mientras tengan diámetros razonables; histológicamente se pueden observar las partículas de amalgama como gránulos oscuros, sólidos e irregulares dispuesto entre los haces de colágeno y vasos sanguíneos. Este artículo refiere el caso clínico de un paciente que presentó pigmentación por amalgama en mucosa vestibular, originada por una porción de amalgama usada como material obturador en una apicectomía del 11 realizada con anterioridad. Teniendo en cuenta las consideraciones clínicas y radiográficas se optó por realizar una segunda apicectomía con obturación retrógrada con MTA del 11. Durante el procedimiento quirúrgico se cureteó y adelgazó la cara interna del colgajo mucoperióstico para tratar de disminuir el grado de pigmentación.

  3. Lectures in plasma diagnostics

    International Nuclear Information System (INIS)

    Hutchinson, I.H.

    1990-06-01

    This paper discusses the following topics on plasma diagnostics: Electric probes in flowing and magnetized plasmas; Electron cyclotron emission absorption; Magnetic diagnostics; Spectroscopy; and Thomson Scattering

  4. Plasma electron losses in a multidipole plasma

    International Nuclear Information System (INIS)

    Haworth, M.D.

    1983-01-01

    The magnitude of the plasma electron cusp losses in a multidipole plasma device is determined by using a plasma electron heating technique. This method consists of suddenly generating approximately monoenergetic test electrons inside the multidipole plasma, which is in a steady-state equilibrium prior to the introduction of the test electrons. The Coulomb collisions between the test electrons and the plasma electrons result in heating the plasma electrons. The experimentally measured time evolution of the plasma electron temperature is compared with that predicted by a kinetic-theory model which calculates the time evolution of the test electron and the plasma electron distribution functions. The analytical solution of the plasma electron heating rate when the test electrons are first introduced into the plasma predicts that there is no dependence on ion mass. Experimental results in helium, neon, argon, and krypton multidipole plasmas confirm this prediction. The time-evolved solution of the kinetic equations must be solved numerically, and these results (when coupled with the experimental heating results) show that the plasma electron cusp-loss width is on the order of an electron Larmor radius

  5. Physics of plasma etching and plasma deposition

    NARCIS (Netherlands)

    Schram, D.C.; Hoog, de F.J.; Bisschops, T.J.; Kroesen, G.M.W.; Howorka, F.; Lindinger, W.; Maerk, T.D.

    1986-01-01

    The kinetics and mechanism of the title processes are discussed on the basis of a model in which the plasma-surface system is subdivided into 5 regions: (I) plasma prodn., (II) plasma flow plus radicals, (III) gas adsorbed layer, (IV) modified surface, and (V) undisturbed solid (or liq.) state.

  6. Quantification of {sup 232}Th, {sup 234}U, {sup 235}U and {sup 238}U in river mollusks by magnetic sector mass spectrometry with inductively coupled plasma source (Icp-SFMS); Cuantificacion de {sup 232}Th, {sup 234}U, {sup 235}U y {sup 238}U en moluscos de rios por espectrometria de masas de sector magnetico con fuente de plasma acoplado inductivamente (ICP-SFMS)

    Energy Technology Data Exchange (ETDEWEB)

    Arevalo R, D. L.; Hernandez M, H.; Romero G, E. T.; Lara A, N. [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Alfaro de la T, M. C., E-mail: arevalo0591@hotmail.com [Universidad Autonoma de San Luis Potosi, Dr. Salvador Nava s/n, Zona Universitaria, 78290 San Luis Potosi, SLP (Mexico)

    2016-09-15

    The present work deals with the methodology established for the quantification of {sup 232}Th, {sup 234}U, {sup 238}U and {sup 235}U in the shell of gastropod mollusks collected in the rivers Valles, Coy and Axtla of San Luis Potosi, Mexico, which belong to the Panuco River basin; these rivers have as main source of pollution the discharge of municipal sewage, waste from small industries, agricultural and cattle residues and from natural sources. Conventional methods for measuring radio-nuclides are confronted with certain conditions related to the requirement in measurement, basically in the characterization that is related to the concepts of precision and accuracy. The analysis of the gastropod mollusk shell was performed by the Icp-SFMS technique; the main advantages of this technique lie in the isotope quantification capacity, the high precision and the low limits of detection, in this study are very important because these elements are in concentrations between ppb and ppt. This technique allowed the analysis of the samples having a complex matrix by the presence CaCO{sub 3} minimizing the interferences thanks to the ionization efficiency of the Ar plasma. For the species Pachychilus monachus were found concentrations of {sup 232}Th of 0.16-5.37 μg/g and of total U of 0.101-4.081 μg/g being this species where the highest values of total U were found. For Thiara (melanoids) tuberculata the lowest values were found among the different species ({sup 232}Th 0.61-3.61 μg/g and total U 0.006-0.042 μg/g), for Pachychilus suturalis, values of {sup 232}Th of 0.58-6.4 μg/g and for Pachychilus sp. were found between 0.26-7.62 μg/g and for total U values between 0.28-3.33 μg/g. The method offers several advantages: speed, good precision, low values of quantification limits and high sensitivity in the measurement of radio-nuclides and heavy metals. (Author)

  7. Fusion plasma physics

    CERN Document Server

    Stacey, Weston M

    2012-01-01

    This revised and enlarged second edition of the popular textbook and reference contains comprehensive treatments of both the established foundations of magnetic fusion plasma physics and of the newly developing areas of active research. It concludes with a look ahead to fusion power reactors of the future. The well-established topics of fusion plasma physics -- basic plasma phenomena, Coulomb scattering, drifts of charged particles in magnetic and electric fields, plasma confinement by magnetic fields, kinetic and fluid collective plasma theories, plasma equilibria and flux surface geometry, plasma waves and instabilities, classical and neoclassical transport, plasma-materials interactions, radiation, etc. -- are fully developed from first principles through to the computational models employed in modern plasma physics. The new and emerging topics of fusion plasma physics research -- fluctuation-driven plasma transport and gyrokinetic/gyrofluid computational methodology, the physics of the divertor, neutral ...

  8. Oscillatory processes in plasma

    International Nuclear Information System (INIS)

    Gallin, E.

    1980-01-01

    The oscillatory process play an important part in plasma evolution, In hot plasma in particular, the interactions between the oscillation modes are preponderant in relation to the binary collisions between particles. The nonlineary interactions between collective plasma oscillations can generate, in this case, a non-balanced steady state of plasma (steady turbulence). The paper elucidates some aspects of the oscillatory phenomena which contribute to the plasma state evolution, especially of hot plasma. A major part of the paper is devoted to the study of parametric instabilities in plasma and their role in increasing the temperature of plasma components (electrons, ions). Both parametric instabilities in plasma in the vicinity of thermodynamic balance and parametric processes is steady turbulent plasma are analysed - in relation to additional heating of hot plasma. An important result of the thesis refers to the drowing-up of a non-lineary interaction model between the oscillation modes in turbulent plasma, being responsible for the electromagnetic radiation in hot plasma. On the basis of the model suggested in the paper the existence of a low frequency radiative mode in hot plasma in a turbulent state, can be demonstrated. Its frequency could be even lower than plasma frequency in the field of long waves be even lower than plasma frequency in the field of long waves. Such a radiative mode was detected experimentally in focussed plasma installations. (author)

  9. Evolution of NADPH-cytochrome P450 oxidoreductases (POR) in Apiales - POR 1 is missing

    DEFF Research Database (Denmark)

    Andersen, Trine Bundgaard; Hansen, Niels Bjørn; Laursen, Tomas

    2016-01-01

    The NADPH-dependent cytochrome P450 oxidoreductase (POR) is the obligate electron donor to eukaryotic microsomal cytochromes P450 enzymes. The number of PORs within plant species is limited to one to four isoforms, with the most common being two PORs per plant. These enzymes provide electrons to ...... (available from the SRA at NCBI). All three genes were shown to be functional upon reconstitution into nanodiscs, confirming that none of the isoforms are pseudogenes....

  10. Analysis of Magnetic Nozzles For Space Plasma Thrusters = Análisis de Toberas Magnéticas para Motores Espaciales de Plasma

    OpenAIRE

    Merino Martínez, Mario

    2013-01-01

    Esta tesis presenta un análisis teórico del funcionamiento de toberas magnéticas para la propulsión espacial por plasmas. El estudio está basado en un modelo tridimensional y bi-fluido de la expansión supersónica de un plasma caliente en un campo magnético divergente. El modelo básico es ampliado progresivamente con la inclusión de términos convectivos dominantes de electrones, el campo magnético inducido por el plasma, poblaciones electrónicas múltiples a distintas temperaturas, y la capacid...

  11. Dust-Plasma Interactions

    International Nuclear Information System (INIS)

    Rosenberg, Marelene

    2005-01-01

    Our theoretical research on dust-plasma interactions has concentrated on three main areas: (a)studies of grain charging and applications; (b) waves and instabilities in weakly correlated dusty plasma with applications to space and laboratory plasmas; (c) waves in strongly coupled dusty plasmas.

  12. Communication through plasma sheaths

    International Nuclear Information System (INIS)

    Korotkevich, A. O.; Newell, A. C.; Zakharov, V. E.

    2007-01-01

    We wish to transmit messages to and from a hypersonic vehicle around which a plasma sheath has formed. For long distance transmission, the signal carrying these messages must be necessarily low frequency, typically 2 GHz, to which the plasma sheath is opaque. The idea is to use the plasma properties to make the plasma sheath appear transparent

  13. Plasma Turbulence General Topics

    Energy Technology Data Exchange (ETDEWEB)

    Kadomtsev, B. B. [Nuclear Energy Institute, Academy of Sciences of the USSR, Moscow, USSR (Russian Federation)

    1965-06-15

    It is known that under experimental conditions plasma often shows chaotic motion. Such motion, when many degrees of freedom are excited to levels considerably above the thermal level, will be called turbulent. The properties of turbulent plasma in many respects differ from the properties of laminar plasma. It can be said that the appearance of various anomalies in plasma behaviour indicates the presence of turbulence in plasma. In order to verify directly the presence of turbulent motion in plasma we must, however, measure the fluctuation of some microscopic parameters in plasma.

  14. Introduction to plasma dynamics

    CERN Document Server

    Morozov, A I

    2013-01-01

    As the twenty-first century progresses, plasma technology will play an increasing role in our lives, providing new sources of energy, ion-plasma processing of materials, wave electromagnetic radiation sources, space plasma thrusters, and more. Studies of the plasma state of matter not only accelerate technological developments but also improve the understanding of natural phenomena. Beginning with an introduction to the characteristics and types of plasmas, Introduction to Plasma Dynamics covers the basic models of classical diffuse plasmas used to describe such phenomena as linear and shock w

  15. Collisionless plasmas in astrophysics

    CERN Document Server

    Belmont, Gerard; Mottez, Fabrice; Pantellini, Filippo; Pelletier, Guy

    2013-01-01

    Collisionless Plasmas in Astrophysics examines the unique properties of media without collisions in plasma physics. Experts in this field, the authors present the first book to concentrate on collisionless conditions in plasmas, whether close or not to thermal equilibrium. Filling a void in scientific literature, Collisionless Plasmas in Astrophysics explains the possibilities of modeling such plasmas, using a fluid or a kinetic framework. It also addresses common misconceptions that even professionals may possess, on phenomena such as "collisionless (Landau) damping". Abundant illustrations

  16. Experimental plasma physics

    International Nuclear Information System (INIS)

    Dreicer, H.; Banton, M.E.; Ingraham, J.C.; Wittman, F.; Wright, B.L.

    1976-01-01

    The Experimental Plasma Physics group's main efforts continue to be directed toward the understanding of the mechanisms of electromagnetic energy absorption in a plasma, and the resultant plasma heating and energy transport. The high-frequency spectrum of plasma waves parametrically excited by the microwave signal at high powers has been measured. The absorption of a small test microwave signal in a plasma made parametrically unstable by a separate high-power driver microwave signal was also studied

  17. Examples of plasma horizons

    International Nuclear Information System (INIS)

    Hanni, R.S.

    1975-01-01

    The concept of the plasma horizon, defined as the boundary of the region in which an infinitely thin plasma can be supported against Coulomb attraction by a magnetic field, shows that the argument of selective accretion does not rule out the existence of charged black holes embedded in a conducting plasma. A detailed account of the covariant definition of plasma horizon is given and some examples of plasma horizons are presented. 7 references

  18. Acuerdo por la discreción

    Directory of Open Access Journals (Sweden)

    Yeny Serrano

    2006-01-01

    Full Text Available En este artículo se propone un análisis del texto del Acuerdo por la discreción firmado en 1999 por 32 directores de medios de comunicación para “elevar el nivel de calidad y responsabilidad en el cubrimiento y difusión de hechos violentos”. Se analizan los factores que impiden que este Acuerdo produzca cambios efectivos en la práctica profesional informativa y se presenta un modelo (Lemieux, 2000 que tiene en cuenta las variables que influyen en la producción del discurso informativo mediático.

  19. ANTIOXIDANTES: MICRONUTRIENTES EN LUCHA POR LA SALUD

    OpenAIRE

    Zamora S, Juan Diego

    2007-01-01

    Los antioxidantes son sustancias químicas que se caracterizan por impedir o retrasar la oxidación de diversas sustancias principalmente de los ácidos grasos cuyas reacciones se producen tanto en los alimentos como en el organismo humano, en el cual puede provocar alteraciones fisiológicas importantes desencadenantes de diversas enfermedades. Otra de las funciones de los antioxidantes es facilitar el uso fisiológico del oxígeno por parte de las mitocondrias celulares, ayudando a reducir los ef...

  20. Alarma activada por control remoto selectivo.

    OpenAIRE

    Eguíluz Morán, Luis Ignacio; Lara Santillán, Pedro María; Mañana Canteli, Mario

    1995-01-01

    La finalidad de esta invención consiste en disponer de una alarma que bien evite el robo de objetos ligeros y portátiles por el procedimiento que se conoce como "del tirón" --es decir, arrebatar algo y salir corriendo--, bien permita identificar un equipaje entre otros. La originalidad del dispositivo reside en la activación/desactivación del dispositivo de sonido por control remoto, así como la posibilidad de seleccionar el sonido de salida dependiendo de su finalidad. Se reivindica como de ...

  1. PANORAMA LATINOAMERICANO DEL PAGO POR SERVICIOS AMBIENTALES

    Directory of Open Access Journals (Sweden)

    González T. Ángela

    2008-07-01

    Full Text Available Este documento busca proveer al lector de algunos elementos para el análisis y reflexión en torno al pago por servicios ambientales. Para ello, en primera instancia, aborda algunos conceptos básicos relacionados con economía ambiental, seguido de temas como la valoración económica de servicios ambientales y la implementación de mecanismos de pago por algunos de ellos. Lo anterior esta enriquecido con experiencias o estudios de caso a nivel latinoamericano y colombiano.

  2. Elements of plasma technology

    CERN Document Server

    Wong, Chiow San

    2016-01-01

    This book presents some fundamental aspects of plasma technology that are important for beginners interested to start research in the area of plasma technology . These include the properties of plasma, methods of plasma generation and basic plasma diagnostic techniques. It also discusses several low cost plasma devices, including pulsed plasma sources such as plasma focus, pulsed capillary discharge, vacuum spark and exploding wire; as well as low temperature plasmas such as glow discharge and dielectric barrier discharge which the authors believe may have potential applications in industry. The treatments are experimental rather than theoretical, although some theoretical background is provided where appropriate. The principles of operation of these devices are also reviewed and discussed.

  3. TFTR plasma feedback systems

    International Nuclear Information System (INIS)

    Efthimion, P.; Hawryluk, R.J.; Hojsak, W.; Marsala, R.J.; Mueller, D.; Rauch, W.; Tait, G.D.; Taylor, G.; Thompson, M.

    1985-01-01

    The Tokamak Fusion Test Reactor employs feedback control systems for four plasma parameters, i.e. for plasma current, for plasma major radius, for plasma vertical position, and for plasma density. The plasma current is controlled by adjusting the rate of change of current in the Ohmic Heating (OH) coil system. Plasma current is continuously sensed by a Rogowski coil and its associated electronics; the error between it and a preprogrammed reference plasma current history is operated upon by a ''proportional-plusintegral-plus-derivative'' (PID) control algorithm and combined with various feedforward terms, to generate compensating commands to the phase-controlled thyristor rectifiers which drive current through the OH coils. The plasma position is controlled by adjusting the currents in Equilibrium Field and Horizontal Field coil systems, which respectively determine the vertical and radial external magnetic fields producing J X B forces on the plasma current. The plasma major radius position and vertical position, sensed by ''B /sub theta/ '' and ''B /sub rho/ '' magnetic flux pickup coils with their associated electronics, are controlled toward preprogrammed reference histories by allowing PID and feedforward control algorithms to generate commands to the EF and HF coil power supplies. Plasma density is controlled by adjusting the amount of gas injected into the vacuum vessel. Time-varying gains are used to combine lineaveraged plasma density measurements from a microwave interferometer plasma diagnostic system with vacuum vessel pressure measurements from ion gauges, with various other measurements, and with preprogrammed reference histories, to determine commands to piezoelectric gas injection valves

  4. Pedro Teixeira y su viaje por Mesopotamia

    Directory of Open Access Journals (Sweden)

    Fuente del Pilar, José Javier

    2005-04-01

    Full Text Available Pedro Teixeira es un integrante notable de la ilustre nómina de los viajeros portugueses que, a finales del s, XVI y principios del XVII, ensancharon para Occidente las fronteras del mundo. Su conocimiento en España se debe a la publicación en 1994 de su obra «Relaciones del Origen, Descendencia y Sucesión de los Reyes de Persia, y de Harmuz, y de un viaje hecho por el autor dende la India hasta Italia por tierra», en edición realizada por el profesor Eduardo Barajas Sala, lamentablemente fallecido en 1997. En este artículo se ofrece una reseña biográfica de Pedro Teixeira, y un análisis del viaje narrado por el autor en la última parte de sus «Relaciones »: el que desde Ormuz le conducirá, a través de Mesopotamia, hasta la costa del Mediterráneo.…

  5. International conference on plasma physics

    International Nuclear Information System (INIS)

    Silin, V.P.; Sitenko, A.G.

    1985-01-01

    A brief report on the 6th International conference on plasma physics and on the 6th International Congress on plasma waves and plasma instabilities, which have taken place in summer 1984 in Losanne, is presented. Main items of the conference are enlightened, such as the general theory of a plasma, laboratory plasma, thermonuclear plasma, cosmic plasma and astrophysics

  6. Plasmas and fluids

    International Nuclear Information System (INIS)

    Anon.

    1986-01-01

    Plasma and fluid physics includes the fields of fusion research and space investigation. This book discusses the most important advances in these areas over the past decade and recommends a stronger commitment to basic research in plasma and fluid physics. The book recommends that plasma and fluid physics be included in physics curriculums because of their increasing importance in energy and defense. The book also lists recent accomplishments in the fields of general plasma physics, fusion plasma confinement and heating, space and astrophysical plasmas, and fluid physics and lists research opportunities in these areas. A funding summary explains how research monies are allocated and suggests ways to improve their effectiveness

  7. Beneficiamento do cultivo do Meloeiro pela apicultura no sertão do Moxotó representado por Modelo Digital do Terreno | Processing of Melon crops for beekeeping in the backwoods of Moxotó represented by Digital Terrain Model

    Directory of Open Access Journals (Sweden)

    Raphael Miller de Souza Caldas

    2016-04-01

    Full Text Available A região Nordeste é a principal produtora de melão do Brasil. O Semiárido brasileiro é uma região caracterizada por apresentar fatores climáticos favoráveis ao desenvolvimento da cultura do meloeiro. No presente estudo foi realizada a modelagem digital do terreno (MDT da microrregião Sertão do Moxotó para os parâmetros de precipitação, temperatura, PIB e IDH, afim de verificar a relação entre a cultura do meloeiro e a apicultura. Os municípios analisados foram Arcoverde, Betânia, Custódia, Ibimirim, Inajá, Sertânia e Manari. O cultivo do meloeiro tem potencial para ser implantado nos municípios do Sertão do Moxotó e está diretamente ligado a apicultura, pois a Apis mellifera é seu principal polinizador. Seu cultivo pode desempenhar papel vital no aumento ou manutenção da produção apícola. The Northeast region is the main melon producer of Brazil. The Brazilian semiarid region is characterized by climatic conditions favorable to the development of melon crop. In the present study, the digital terrain modeling (DTM of Sertão do Moxotó was performed to precipitation parameters, temperature, GDP, HDI and population in order to verifythe relationship between melon crop and apiculture. The districts analyzed were Arcoverde, Betânia, Custódia, Ibimirim, Inajá, Sertânia and Manari. Apis mellifera is the main pollinator of melon crop. Melon crop can support the bees during the shortage of bee flora and increase in bee production.

  8. Special issue: Plasma Conversion

    NARCIS (Netherlands)

    Nozaki, T.; Bogaerts, A.; Tu, X.; van de Sanden, M. C. M.

    2017-01-01

    With growing concern of energy and environmental issues, the combination of plasma and heterogeneous catalysts receives special attention in greenhouse gas conversion, nitrogen fixation and hydrocarbon chemistry. Plasma gas conversion driven by renewable electricity is particularly important for the

  9. Neutrino beam plasma instability

    Indian Academy of Sciences (India)

    positron or electron–proton plasma in the context of early universe, stars and supernova ... proper. Of course, in their later work on kinetic theory (KT) [5] of neutrino plasma inter- .... for electron also with additional electric potential term.

  10. Plasma kinetic theory

    International Nuclear Information System (INIS)

    Elliott, J.A.

    1993-01-01

    Plasma kinetic theory is discussed and a comparison made with the kinetic theory of gases. The plasma is described by a modified set of fluid equations and it is shown how these fluid equations can be derived. (UK)

  11. Physics of laser plasma

    International Nuclear Information System (INIS)

    Rubenchik, A.; Witkowski, S.

    1991-01-01

    This book provides a comprehensive review of laser fusion plasma physics and contains the most up-to-date information on high density plasma physics and radiation transport, useful for astrophysicists and high density physicists

  12. Plasma heating in collisionless plasma at low plasma density

    International Nuclear Information System (INIS)

    Wulf, H.O.

    1977-01-01

    The high frequency heating of a collisionless, fully ionized low density plasma is investigated in the range: 2ωc 2 2 under pumping frequencies. A pulsed 1 MHz transmitter excites a fast standing, magneto-acoustical wave in the plasma, via the high frequency magnetic field of a Stix solenoid. The available modulation degrees are between 0.7 and 7.0%. As power consumption measurements show, there appears at all investigated pumping frequencies an effective energy transfer to the plasma that cannot be explained with the classical MHD models. Measurements with electrostatic probes and further with a miniature counter-field spectrometer yield an electron and ion temperature gain of two to three factors and 15-18, compared to the corresponding values in the initial plasma. (orig./HT) [de

  13. Introduction to Plasma Physics

    Science.gov (United States)

    Gurnett, Donald A.; Bhattacharjee, Amitava

    2017-03-01

    Preface; 1. Introduction; 2. Characteristic parameters of a plasma; 3. Single particle motions; 4. Waves in a cold plasma; 5. Kinetic theory and the moment equations; 6. Magnetohydrodynamics; 7. MHD equilibria and stability; 8. Discontinuities and shock waves; 9. Electrostatic waves in a hot unmagnetized plasma; 10. Waves in a hot magnetized plasma; 11. Nonlinear effects; 12. Collisional processes; Appendix A. Symbols; Appendix B. Useful trigonometric identities; Appendix C. Vector differential operators; Appendix D. Vector calculus identities; Index.

  14. Plasma-wall interaction

    International Nuclear Information System (INIS)

    Reichle, R.

    2004-01-01

    This document gathers the 43 slides presented in the framework of the week long lecture 'hot plasmas 2004' and dedicated to plasma-wall interaction in a tokamak. This document is divided into 4 parts: 1) thermal load on the wall, power extraction and particle recovery, 2) basic edge plasma physics, 3) processes that drive the plasma-solid interaction, and 4) material conditioning (surface treatment...) for ITER

  15. Plasma physics an introduction

    CERN Document Server

    Fitzpatrick, Richard

    2014-01-01

    Plasma Physics: An Introduction is based on a series of university course lectures by a leading name in the field, and thoroughly covers the physics of the fourth state of matter. This book looks at non-relativistic, fully ionized, nondegenerate, quasi-neutral, and weakly coupled plasma. Intended for the student market, the text provides a concise and cohesive introduction to plasma physics theory, and offers a solid foundation for students wishing to take higher level courses in plasma physics.

  16. Application of plasma focus device to compression of toroidal plasma

    International Nuclear Information System (INIS)

    Ikuta, Kazunari

    1980-01-01

    A new concept of compressing a toroidal plasma using a plasma focus device is considered. Maximum compression ratio of toroidal plasma is determined merely by the initial density ratio of the toroidal plasma to a sheet plasma in a focus device because of the Rayleigh-Taylor instability. An initiation senario of plasma-linear is also proposed with a possible application of this concepts to the creation of a burning plasma in reversed field configurations, i.e., burning plasma vortex. (author)

  17. Conservación por calor

    OpenAIRE

    Cobos García, Angel; Díaz Rubio, Olga

    2011-01-01

    Esta unidade didáctica denominada Conservación por calor forma parte da materia «Tecnoloxía do procesado de alimentos» que se impartirá no primeiro semestre do 2º curso do Grao en Nutrición Humana e Dietética. A materia estrutúrase en diferentes unidades didácticas, tratando cada unha delas as diferentes tecnoloxías de procesado dos alimentos, tanto de conservación coma de transformación. A presente unidade didáctica aborda a conservación dos alimentos por calor. Este método permite destruír ...

  18. Celulitis por cuerpo extraño

    Directory of Open Access Journals (Sweden)

    Miguel B. Carrasco Guzmán

    2016-01-01

    Full Text Available Las infecciones de la piel y el tejido celular subcutáneo surgen como un grupo importante de afecciones con una alta morbilidad en edades pediátricas, generalmente relacionada con traumatismo y cuerpos extraños. Se presenta el caso de una escolar femenina de 6 años de edad, con síntomas y signos clínicos que sugieren celulitis en el muslo derecho,  por su evolución tórpida se le realizó el estudio ultrasonográfico que confirmó el diagnóstico etiológico de una celulitis secundaria a un traumatismo, provocada por la introducción de un gran cuerpo extraño, que pasó inadvertido para a familia de la menor.

  19. Plasma membrane ATPases

    DEFF Research Database (Denmark)

    Palmgren, Michael Broberg; Bækgaard, Lone; Lopez Marques, Rosa Laura

    2011-01-01

    The plasma membrane separates the cellular contents from the surrounding environment. Nutrients must enter through the plasma membrane in order to reach the cell interior, and toxic metabolites and several ions leave the cell by traveling across the same barrier. Biological pumps in the plasma me...

  20. Plasma in wound healing

    NARCIS (Netherlands)

    Tipa, R.S.

    2012-01-01

    Plasmas, due to their electrical and chemical properties, release in the invironment a unique cocktail of charged species, energetic photons and active radicals. Plasmas have a miriad of applications. To mention just a few, plasmas are being used in the semiconductors industry, atomic layer

  1. Plasma in astrophysics

    International Nuclear Information System (INIS)

    Kulsrud, R.M.

    1982-10-01

    Two examples of plasma phenomena of importance to astrophysics are reviewed. These are examples where astrophysical understanding hinges on further progress in plasma physics understanding. The two examples are magnetic reconnection and the collisionless interaction between a population of energetic particles and a cooler gas or plasma, in particular the interaction between galactic cosmic rays and the interstellar medium

  2. Plasma processing and chemistry

    NARCIS (Netherlands)

    Schram, D.C.; Mullen, van der J.J.A.M.; Sanden, van de M.C.M.

    1994-01-01

    The growing field of applications of plasma as deposition, etching, surface modification and chemical conversion has stimulated a renewed interest in plasma science in the atomic physical chemistry regime. The necessity to optimize the various plasma processing techniques in terms of rates, and

  3. MIASIS CUTÁNEA POR CORDYLOBIA ANTHROPOPHAGA

    Directory of Open Access Journals (Sweden)

    Miriam Alkorta Gurrutxaga

    2001-01-01

    Full Text Available El incremento progresivo en el número de personas que viajan a países tropicales ha hecho que las enfermedades importadas adquieran una relevancia cada vez mayor. Las miasis (o infestaciones por larvas de moscas cutáneas se encuentran entre este tipo de enfermedades siendo especialmente frecuentes en países tropicales. A propósito de la observación de un caso de miasis cutánea masiva por Cordylobia antropophaga, que ocurrió en una mujer de 34 años de edad al volver de un viaje a Senegal, se ha efectuado una revisión de los casos de miasis cutáneas forunculoides importadas publicados en España, así como de la biología, patología, tratamiento y prevención de la miasis humana por Cordylobia anthropophaga. El caso referido, se caracterizó por la infestación con un número inusualmente elevado de larvas, no sospechándose su etiología hasta la fase final de la enfermedad. La emergencia continuada de larvas (se recogieron 91 generó en la paciente un estado de ansiedad importante. Finalmente, la eliminación de las larvas provocó una rápida mejoría de la paciente. Aunque los casos de miasis cutánea no tienen la gravedad de otras enfermedades importadas, su conocimiento es necesario desde el punto de vista preventivo, diagnóstico y terapeútico. Es importante proceder a la identificación morfológica de las larvas diferenciándolas de otro tipo de miasis con implicaciones terapéuticas diferentes.

  4. Compostos antimicrobianos produzidos por Streptomyces Spp.

    OpenAIRE

    Silva, Ingrid Reis da

    2012-01-01

    O aumento crescente de bact?rias resistentes a antibi?ticos incentiva ? pesquisa por novas subst?ncias antibacterianas. Diante disso, a sele??o de microrganismos com potencial para a produ??o de novos compostos antimicrobianos tem sido amplamente estudada. Dentre estes microrganismos uma especial aten??o ? dada aos actinomicetos que apresentam capacidade de produzir uma variedade de compostos bioativos como antibi?ticos, antif?ngicos, antitumorais entre outros compostos que pod...

  5. Amar por cartas - este inferno de amara

    Directory of Open Access Journals (Sweden)

    Matildes Demetrio dos Santos

    1999-10-01

    Full Text Available Este trabalho tem por objetivo estudar o amor nas Folhas caídas e nas Cartas de amor à Viscondessa da Luz, de Almeida Garrett.Seus poemas cheios de erotismo e sensua lidade, inspirados numa mulher casada, Rosa Montúrar Infante, escandalizaram a sociedade portuguesado sécu lo XIX. Suas cartas de amor, em segredo, criavam uma ficção de características místicas.

  6. Por un humor ético

    Directory of Open Access Journals (Sweden)

    Victor Paramo Valero

    2016-04-01

    Full Text Available Ética del humor es una obra original, abundantemente documentada, de contenido científico y filosófico, que aborda un problema de gran importancia en los actuales estudios de éticas aplicadas. La ética del humor es una nueva ética aplicada que pretende comprender el fenómeno del humor a la luz de sus implicaciones éticas. Como señala el autor, Juan Carlos Siurana, reputado experto en el ámbito de la filosofía práctica, el interés por el humor es un interés por la ética. En la obra no presenta una nueva teoría filosófica del humor –las cuales se han venido sucediendo, al menos, desde los Diálogos de Platón–, sino una nueva teoría ética, que toma al humor como objeto principal de análisis. Por tanto, la finalidad es realizar una aportación dentro del ámbito de la ética. Para ello se nutre de distintos estudios psicológicos, biológicos, fisiológicos y neurológicos sobre el humor, así como de clásicas obras de filosofía que han abordado esta cuestión.

  7. El aprendizaje visto por los estudiantes venezolanos

    Directory of Open Access Journals (Sweden)

    Berta Elena Barrios

    2015-01-01

    Full Text Available En el siguiente trabajo se presentan los resultados de un estudio sobre las con-cepciones del aprendizaje de un grupo de estudiantes venezolanos de educa-ción primaria y media. Se trató de replicar el instrumento y procedimiento deanálisis utilizado por los investigadores Berry y Sahlberg (1996, con el objetivode caracterizar cómo conciben el aprendizaje estudiantes venezolanos entre 11y 15 años de edad y compararlo con sus pares ingleses y finlandeses. El análi-sis de resultados se basó en los criterios propuestos por dichos autores, deno-minados Pasos para un Buen Aprendizaje. Los hallazgos indican que los estu-diantes venezolanos conciben el aprendizaje como memorizar conocimientos,básicamente escolares, enseñados por los docentes. Las concepciones deambas poblaciones se ubican en una visión pasiva del aprendizaje. Se discutela vinculación de las concepciones del aprendizaje con las prácticas de la escuela.

  8. Eritema multiforme mayor desencadenado por antimicrobianos

    Directory of Open Access Journals (Sweden)

    Ronaldo de Carvalho Raimundo

    2010-03-01

    Full Text Available El eritema multiforme, aparece como una enfermedad sistémica con la participación de la piel y las membranas mucosas en relación con varios factores como las infecciones bacterianas o virales, y en particular la administración de drogas, analgésicos y antibióticos en general. Se presenta un paciente masculino de 29 años de edad con eritema multiforme mayor desencadenado por antimicrobianos con la aparición de lesiones vesiculares-bulloso-ulcerosas en las regiones de los labios, encías, la lengua y la mucosa genital en tratamiento de una infección del tracto urinario con norfloxacino 400 mg por una semana. Fue realizado un tratamiento de soporte con el uso de colutorios para la higienización bucal y pomada a base de corticoide para protección de las úlceras, antihistamínicos y orientación nutricional de dieta líquida hipercalórica e hiperproteica. Este síndrome está caracterizado como un proceso eruptivo buloso agudo que compromete la calidad de vida del paciente y no hay pruebas de laboratorio específicas por lo que su diagnóstico debe estar basado en la revisión minuciosa de la anamnesis y en los hallazgos clínicos.

  9. Some aspects of plasma thermodynamics

    International Nuclear Information System (INIS)

    Gorgoraki, V.I.

    1986-01-01

    The objective reasons which have inhibited the development of a plasma-thermodynamics theory are discussed and the authors formulate the fundamental principles which can be the basis of a common plasma-thermodynamics theory. Two kinds of thermodynamic equilibrium plasmas are discussed, an isothermal plasma and a nonisothermal plasma. An isothermal plasma is a high-temperature plasma; the Saha-Eggert equation describes its behavior. A nonisothermal plasma is a low-temperature plasma, and the reactions taking place therein are purely plasma-chemical. The ionization equilibrium and the composition of such a plasma can be found with the aid of the equations presented in this paper

  10. Space plasma simulation chamber

    International Nuclear Information System (INIS)

    1986-01-01

    Scientific results of experiments and tests of instruments performed with the Space Plasma Simulation Chamber and its facility are reviewed in the following six categories. 1. Tests of instruments on board rockets, satellites and balloons. 2. Plasma wave experiments. 3. Measurements of plasma particles. 4. Optical measurements. 5. Plasma production. 6. Space plasms simulations. This facility has been managed under Laboratory Space Plasma Comittee since 1969 and used by scientists in cooperative programs with universities and institutes all over country. A list of publications is attached. (author)

  11. Computations in plasma physics

    International Nuclear Information System (INIS)

    Cohen, B.I.; Killeen, J.

    1984-01-01

    A review of computer application in plasma physics is presented. Computer contribution to the investigation of magnetic and inertial confinement of a plasma and charged particle beam propagation is described. Typical utilization of computer for simulation and control of laboratory and cosmic experiments with a plasma and for data accumulation in these experiments is considered. Basic computational methods applied in plasma physics are discussed. Future trends of computer utilization in plasma reseaches are considered in terms of an increasing role of microprocessors and high-speed data plotters and the necessity of more powerful computer application

  12. Model of detached plasmas

    International Nuclear Information System (INIS)

    Yoshikawa, S.; Chance, M.

    1986-07-01

    Recently a tokamak plasma was observed in TFTR that was not limited by a limiter or a divertor. A model is proposed to explain this equilibrium, which is called a detached plasma. The model consists of (1) the core plasma where ohmic heating power is lost by anomalous heat conduction and (2) the shell plasma where the heat from the core plasma is radiated away by the atomic processes of impurity ions. A simple scaling law is proposed to test the validity of this model

  13. Mirror plasma apparatus

    International Nuclear Information System (INIS)

    Moir, R.W.

    1981-01-01

    A mirror plasma apparatus which utilizes shielding by arc discharge to form a blanket plasma and lithium walls to reduce neutron damage to the wall of the apparatus. An embodiment involves a rotating liquid lithium blanket for a tandem mirror plasma apparatus wherein the first wall of the central mirror cell is made of liquid lithium which is spun with angular velocity great enough to keep the liquid lithium against the first material wall, a blanket plasma preventing the lithium vapor from contaminating the plasma

  14. Contemporary plasma physics

    International Nuclear Information System (INIS)

    Sodha, M.S.; Tewari, D.P.; Subbarao, D.

    1983-01-01

    The book consists of review articles on some selected contemporary aspects of plasma physics. The selected topics present a panoramic view of contemporary plasma physics and applications to fusion, space and MHD power generation. Basic non-linear plasma theory is also covered. The book is supposed to be useful for M.S./M.Sc. students specialising in plasma physics and for those beginning research work in plasma physics. It will also serve as a valuable reference book for more advanced research workers. (M.G.B.)

  15. ECR Plasma Photos

    International Nuclear Information System (INIS)

    Racz, R.; Biri, S.; Palinkas, J.

    2009-01-01

    Complete text of publication follows. In order to observe and study systematically the plasma of electron cyclotron resonance (ECR) ion sources (ECRIS) we made a high number of high-resolution visible light plasma photos and movies in the ATOMKI ECRIS Laboratory. This required building the ECR ion source into an open plasma device, temporarily. An 8MP digital camera was used to record photos of plasmas made from He, methane, N, O, Ne, Ar, Kr, Xe gases and from their mixtures. The effects of the main external setting parameters (gas pressure, gas composition, magnetic field, microwave power, microwave frequency) were studied to the shape, color and structure of the plasma. The double frequency mode (9+14 GHz) was also realized and photos of this special 'star-in-star' shape plasma were recorded. A study was performed to analyze and understand the color of the ECR plasmas. The analysis of the photo series gave us many qualitative and numerous valuable physical information on the nature of ECR plasmas. To our best knowledge our work is the first systematic study of ECR plasmas in the visible light region. When looking in the plasma chamber of an ECRIS we can see an axial image of the plasma (figure 1) in conformity with experimental setup. Most of the quantitative information was obtained through the summarised values of the Analogue Digital Unit (ADU) of pixels. By decreasing the strength of the magnetic trap we clearly observed that the brightness of the central part of the plasma gradually decreases, i.e. the plasma becomes more and more 'empty'. Figure 2 shows a photo series of ECR plasma at decreasing axial magnetic field. The radial size of the plasma increased because of the ascendant resonant zone. By increasing the power of the injected microwave an optimum (or at least saturation) was found in the brightness of the plasma. We found correlation between the gas dosing rates and plasma intensities. When sweeping the frequency of the microwave in a wide region

  16. Cyclotron waves in plasma

    CERN Document Server

    Lominadze, D G

    2013-01-01

    Cyclotron Waves in Plasma is a four-chapter text that covers the basic physical concepts of the theory of cyclotron waves and cyclotron instabilities, brought about by the existence of steady or alternating plasma currents flowing perpendicular to the magnetic field.This book considers first a wide range of questions associated with the linear theory of cyclotron oscillations in equilibrium plasmas and in electron plasmas in metals and semiconductors. The next chapter deals with the parametric excitation of electron cyclotron oscillations in plasma in an alternating electric field. A chapter f

  17. Introduction to plasma engineering

    International Nuclear Information System (INIS)

    Roth, J.R.

    1988-01-01

    The author has begun writing a textbook entitled Introduction to Plasma Engineering, which is intended for upper division undergraduates or professionals who are entering the field. This paper features a detailed topical outline of all 20 chapters of the book. The text is organized so that the first five chapters cover plasma physics and basic principles; the next 13 chapters cover the most important engineering applications of plasmas, in order of increasing plasma energy/number density; and two final chapters cover plasma diagnostics and magnetic coil design

  18. Imunodepressão induzida por talidomida e ciclosporina em transplante cardíaco heterotópico de coelho

    Directory of Open Access Journals (Sweden)

    João Batista Vieira de Carvalho

    Full Text Available OBJETIVO: A talidomida, por seus efeitos antiinflamatórios e imunodepressores, tem sido utilizada no tratamento de doenças dermatológicas e na doença enxerto-contra-hospedeiro no transplante de medula óssea. O objetivo deste trabalho é avaliar a ação deste medicamento como imunodepressor em transplante de órgãos, estudando sua ação isoladamente ou em combinação com a ciclosporina na prevenção da rejeição ao aloenxerto cardíaco heterotópico em coelho. MÉTODO: Foram utilizados 50 coelhos, sendo 25 doadores e 25 receptores.Os animais receptores foram subdivididos em cinco grupos (n= 5 : Grupo I (controle animais não-imunodeprimidos; Grupo II (imunodeprimidos com ciclosporina na dose de 10 mg/kg/dia; Grupo III (imunodeprimidos com talidomida na dose de 100 mg/kg/dia; Grupo IV (imunodeprimidos com ciclosporina na dose de 5,0 mg/kg/dia e Grupo V (imunodeprimidos com ciclosporina na dose de 5,0 mg/kg/dia associada a talidomida na dose de 50 mg/kg/dia. Os medicamentos foram administrados através de cateter orogástrico, a partir do dia anterior ao transplante. RESULTADOS: O coração do doador foi implantado no abdome dos receptores. A associação de talidomida e ciclosporina apresentou o menor escore histopatológico de rejeição (p < 0,05. Observou-se que a talidomida empregada isoladamente ou associada à ciclosporina foi efetiva contra a rejeição, aumentando a sobrevida (p < 0,01 de animais submetidos ao transplante cardíaco heterotópico em posição abdominal. CONCLUSÕES: A talidomida empregada isoladamente, ou associada à ciclosporina, pode representar uma opção de imunodepressão em transplantes cardíaco heterotópico experimental de coelho.

  19. Structural Insights into the PorK and PorN Components of the Porphyromonas gingivalis Type IX Secretion System.

    Science.gov (United States)

    Gorasia, Dhana G; Veith, Paul D; Hanssen, Eric G; Glew, Michelle D; Sato, Keiko; Yukitake, Hideharu; Nakayama, Koji; Reynolds, Eric C

    2016-08-01

    The type IX secretion system (T9SS) has been recently discovered and is specific to Bacteroidetes species. Porphyromonas gingivalis, a keystone pathogen for periodontitis, utilizes the T9SS to transport many proteins including the gingipain virulence factors across the outer membrane and attach them to the cell surface via a sortase-like mechanism. At least 11 proteins have been identified as components of the T9SS including PorK, PorL, PorM, PorN and PorP, however the precise roles of most of these proteins have not been elucidated and the structural organization of these components is unknown. In this study, we purified PorK and PorN complexes from P. gingivalis and using electron microscopy we have shown that PorN and the PorK lipoprotein interact to form a 50 nm diameter ring-shaped structure containing approximately 32-36 subunits of each protein. The formation of these rings was dependent on both PorK and PorN, but was independent of PorL, PorM and PorP. PorL and PorM were found to form a separate stable complex. PorK and PorN were protected from proteinase K cleavage when present in undisrupted cells, but were rapidly degraded when the cells were lysed, which together with bioinformatic analyses suggests that these proteins are exposed in the periplasm and anchored to the outer membrane via the PorK lipid. Chemical cross-linking and mass spectrometry analyses confirmed the interaction between PorK and PorN and further revealed that they interact with the PG0189 outer membrane protein. Furthermore, we established that PorN was required for the stable expression of PorK, PorL and PorM. Collectively, these results suggest that the ring-shaped PorK/N complex may form part of the secretion channel of the T9SS. This is the first report showing the structural organization of any T9SS component.

  20. Structural Insights into the PorK and PorN Components of the Porphyromonas gingivalis Type IX Secretion System.

    Directory of Open Access Journals (Sweden)

    Dhana G Gorasia

    2016-08-01

    Full Text Available The type IX secretion system (T9SS has been recently discovered and is specific to Bacteroidetes species. Porphyromonas gingivalis, a keystone pathogen for periodontitis, utilizes the T9SS to transport many proteins including the gingipain virulence factors across the outer membrane and attach them to the cell surface via a sortase-like mechanism. At least 11 proteins have been identified as components of the T9SS including PorK, PorL, PorM, PorN and PorP, however the precise roles of most of these proteins have not been elucidated and the structural organization of these components is unknown. In this study, we purified PorK and PorN complexes from P. gingivalis and using electron microscopy we have shown that PorN and the PorK lipoprotein interact to form a 50 nm diameter ring-shaped structure containing approximately 32-36 subunits of each protein. The formation of these rings was dependent on both PorK and PorN, but was independent of PorL, PorM and PorP. PorL and PorM were found to form a separate stable complex. PorK and PorN were protected from proteinase K cleavage when present in undisrupted cells, but were rapidly degraded when the cells were lysed, which together with bioinformatic analyses suggests that these proteins are exposed in the periplasm and anchored to the outer membrane via the PorK lipid. Chemical cross-linking and mass spectrometry analyses confirmed the interaction between PorK and PorN and further revealed that they interact with the PG0189 outer membrane protein. Furthermore, we established that PorN was required for the stable expression of PorK, PorL and PorM. Collectively, these results suggest that the ring-shaped PorK/N complex may form part of the secretion channel of the T9SS. This is the first report showing the structural organization of any T9SS component.

  1. Applied plasma physics

    International Nuclear Information System (INIS)

    Anon.

    1979-01-01

    Applied Plasma Physics is a major sub-organizational unit of the Magnetic Fusion Energy (MFE) Program. It includes Fusion Plasma Theory and Experimental Plasma Research. The Fusion Plasma Theory group has the responsibility for developing theoretical-computational models in the general areas of plasma properties, equilibrium, stability, transport, and atomic physics. This group has responsibility for giving guidance to the mirror experimental program. There is a formal division of the group into theory and computational; however, in this report the efforts of the two areas are not separated since many projects have contributions from members of both. Under the Experimental Plasma Research Program we are developing a neutral-beam source, the intense, pulsed ion-neutral source (IPINS), for the generation of a reversed-field configuration on 2XIIB. We are also studying the feasibility of using certain neutron-detection techniques as plasma diagnostics in the next generation of thermonuclear experiments

  2. Plasma polymerization by Softplasma

    DEFF Research Database (Denmark)

    Jiang, J.; Wu, Zhenning; Benter, Maike

    2008-01-01

    , external electrode, and electrodeless microwave or high frequency reactors. [3] Softplasma™ is an internal electrode plasma setup powered by low frequenc~ gower supply. It was developed in late 90s for surface treatment of silicone rubber. [ ]- 5] It is a low pressure, low electron density, 3D homogenous......In the late 19th century, the first depositions - known today as plasma polymers, were reported. In the last century, more and more research has been put into plasma polymers. Many different deposition systems have been developed. [1, 2] Shi F. F. broadly classified them into internal electrode...... plasma. In this study, we are presenting the surface modification"pf polymers by plasma polymerization using Softplasma™. Softplasma™ can be used for two major types of polymerization: polymerization of vinyl monomers, where plasma acts as initiator; chemical vapour deposition, where plasma acts...

  3. Plasma engineering: a perspective

    International Nuclear Information System (INIS)

    Gralnick, S.L.

    1978-01-01

    This review paper will present the authors perspective of the field of Plasma Engineering as it has evolved over the preceding five years. This embrionic discipline has grown in that period of time to the point where it is sufficiently mature to become part of the curriculum, and a speciality within, the discipline of Nuclear Engineering. Plasma Engineering can be distinguished from the underlying science of plasma physics in that in the pursuit of the latter, our goal is the understanding of the fundamental processes governing the behavior of plasmas while the former discipline seeks the embodiment of these concepts in useful devices. Consequent to this goal, the plasma engineer, of necessity, is concerned with the interfaces between a plasma configuration and the device by which it is produced and maintained. These interface problems, often referred to as kitchen physics are multidisciplinary in nature, and their solution requires careful attention to both plasma physics and machine engineering detail

  4. Applied plasma physics

    International Nuclear Information System (INIS)

    Anon.

    1978-01-01

    Applied Plasma Physics is a major sub-organizational unit of the MFE Program. It includes Fusion Plasma Theory and Experimental Plasma Research. The Fusion Plasma Theory group has the responsibility for developing theoretical-computational models in the general areas of plasma properties, equilibrium, stability, transport, and atomic physics. This group has responsibility for giving guidance to the mirror experimental program. There is a formal division of the group into theory and computational; however, in this report the efforts of the two areas are not separated since many projects have contributions from members of both. Under the Experimental Plasma Research Program, we are developing the intense, pulsed neutral-beam source (IPINS) for the generation of a reversed-field configuration on 2XIIB. We are also studying the feasibility of utilizing certain neutron-detection techniques as plasma diagnostics in the next generation of thermonuclear experiments

  5. Metallurgical plasma torches

    International Nuclear Information System (INIS)

    Shapovalov, V.A.; Latash, Yu.V.

    2000-01-01

    The technological equipment for the plasma heating of metals, plasma melting and plasma treatment of the surface is usually developed on the basis of are plasma torches using direct or alternating current. The reasons which partly restrict the industrial application of the plasma torches are the relatively short service life of the electrode (cathode) on which the arc is supported, and the contamination of the treated metal with the products of failure of the electrode. The aim of this work was to determine the reasons for the occurrence of negative phenomena observed in the process of service of plasma torches, and propose suitable approaches to the design of metallurgical plasma torches characterised by a long service life

  6. Campo magnético generado por N bobinas alineadas axialmente

    OpenAIRE

    César Gutiérrez Tapia; Javier González Damián

    2002-01-01

    El cálculo del campo magnético generado por n bobinas axialmente alineadas permanece como un importante problema técnico en el proceso de construcción de los diferentes dispositivos para confinar el plasma con perfiles de campo externo tipo espejo. A partir de los métodos numéricos existentes para el cálculo de las integrales elípticas de primera clase k y segunda clase e, se describe la obtención de expresiones simples para calcular el campo magnético por el método de las ecuaciones elíptica...

  7. Plasmas for medicine

    Science.gov (United States)

    von Woedtke, Th.; Reuter, S.; Masur, K.; Weltmann, K.-D.

    2013-09-01

    Plasma medicine is an innovative and emerging field combining plasma physics, life science and clinical medicine. In a more general perspective, medical application of physical plasma can be subdivided into two principal approaches. (i) “Indirect” use of plasma-based or plasma-supplemented techniques to treat surfaces, materials or devices to realize specific qualities for subsequent special medical applications, and (ii) application of physical plasma on or in the human (or animal) body to realize therapeutic effects based on direct interaction of plasma with living tissue. The field of plasma applications for the treatment of medical materials or devices is intensively researched and partially well established for several years. However, plasma medicine in the sense of its actual definition as a new field of research focuses on the use of plasma technology in the treatment of living cells, tissues, and organs. Therefore, the aim of the new research field of plasma medicine is the exploitation of a much more differentiated interaction of specific plasma components with specific structural as well as functional elements or functionalities of living cells. This interaction can possibly lead either to stimulation or inhibition of cellular function and be finally used for therapeutic purposes. During recent years a broad spectrum of different plasma sources with various names dedicated for biomedical applications has been reported. So far, research activities were mainly focused on barrier discharges and plasma jets working at atmospheric pressure. Most efforts to realize plasma application directly on or in the human (or animal) body for medical purposes is concentrated on the broad field of dermatology including wound healing, but also includes cancer treatment, endoscopy, or dentistry. Despite the fact that the field of plasma medicine is very young and until now mostly in an empirical stage of development yet, there are first indicators of its enormous

  8. Plasma sheath in non-Maxwellian plasma

    International Nuclear Information System (INIS)

    Shimizu, Takuo; Horigome, Takashi

    1992-01-01

    Reviewing many theoretical and experimental works on the electron-energy distributions (EEDF) of various plasmas, we point out that many plasmas have EEDF of non-Maxwellian in shape. Therefore, the recent treatment of plasma sheath using the Maxwell-Boltzmann distribution approximation should be improved. To do this, we have adopted Rutcher's standard distribution as a generalized form in place of the traditional Maxwellian, and found that the minimum energy of ions entering the sheath edge (Bohm's criterion) varies largely, and have also shown the variation of Debye length with the shape of EEDF. The length is the most important parameter to proceed with more detailed analysis on plasma-sheaths, and also to control them in the future. (author)

  9. Particle modeling of plasmas computational plasma physics

    International Nuclear Information System (INIS)

    Dawson, J.M.

    1991-01-01

    Recently, through the development of supercomputers, a powerful new method for exploring plasmas has emerged; it is computer modeling of plasmas. Such modeling can duplicate many of the complex processes that go on in a plasma and allow scientists to understand what the important processes are. It helps scientists gain an intuition about this complex state of matter. It allows scientists and engineers to explore new ideas on how to use plasma before building costly experiments; it allows them to determine if they are on the right track. It can duplicate the operation of devices and thus reduce the need to build complex and expensive devices for research and development. This is an exciting new endeavor that is in its infancy, but which can play an important role in the scientific and technological competitiveness of the US. There are a wide range of plasma models that are in use. There are particle models, fluid models, hybrid particle fluid models. These can come in many forms, such as explicit models, implicit models, reduced dimensional models, electrostatic models, magnetostatic models, electromagnetic models, and almost an endless variety of other models. Here the author will only discuss particle models. He will give a few examples of the use of such models; these will be taken from work done by the Plasma Modeling Group at UCLA because he is most familiar with work. However, it only gives a small view of the wide range of work being done around the US, or for that matter around the world

  10. Vasculitis inducida por metimazol: Reporte de caso

    Directory of Open Access Journals (Sweden)

    Miguel Pinto

    2011-07-01

    Full Text Available Se reporta el caso de una paciente con enfermedad de Graves, que presentó vasculitis asociada al uso de metimazol. Mujer de 14 años, que acudió a consulta por presentar intolerancia al calor, tremor distal y palpitaciones. El examen físico mostró bocio difuso, y el perfil tiroideo, TSH suprimida y hormonas tiroideas elevadas. Los anticuerpos antiperoxidasa tiroidea fueron positivos. Se inició tratamiento con metimazol y beta bloqueadores. Después de 20 días, la paciente regresó por presentar malestar general, fiebre, poliartralgia, lesiones cutáneas maculopapulares y edema de miembros inferiores. Los anticuerpos antinucleares fueron negativos y los anticuerpos anticitoplasma de los neutrófilos (ANCA, positivos. Se suspendió el metimazol y se inició prednisona. Después de 10 días de tratamiento, las molestias desaparecieron y la paciente recibió I 131.Las vasculitis asociadas al uso de tionamidas son poco frecuentes, no dependen de la dosis y están asociadas a la presencia de anticuerpos tipo ANCA. Clásicamente, afectan a los vasos pequeños de la piel; sin embargo, también pueden afectar los riñones y pulmones. El cuadro clínico se caracteriza por artralgias y mialgias. En algunos casos puede ocurrir insuficiencia renal de grado variable. En la mayoría de casos, el cuadro remite con la suspensión de la droga; pero, en algunos se requiere el uso de glucocorticoides o inmunosupresores.(Rev Med Hered 2011;22:147-150.

  11. Cefaleia por uso excessivo de medicamentos

    Directory of Open Access Journals (Sweden)

    Ariane Maria Fonseca MIRANDA

    2015-01-01

    Full Text Available Uma variante da cefaleia crônica diária, a cefaleia por uso excessivo de medicamentos é uma manifestação clínica de frequência ≥ 15 dias por mês, durante 3 meses. Possui um diagnóstico deficiente e um tratamento dividido em etapas, sendo a desintoxicação, a etapa de fundamental importância. Este artigo apresenta uma revisão sobre o tema, contribuindo para o esclarecimento das principais manifestações clínicas, principais teorias envolvendo sua fisiopatologia e a terapêutica farmacológica empregada. A metodologia utilizada foi uma revisão de publicações europeias e americanas, no período de 2001 a 2013, nos idiomas português, inglês e espanhol. Todos os medicamentos utilizados no tratamento sintomático das cefaleias são capazes de cronificar uma cefaleia preexistente, desde que sejam utilizados excessivamente, de forma regular e continuada. A suspensão de tais agentes terapêuticos resultará em melhoria na maioria dos pacientes, porém pode ser necessária a introdução de uma terapia de suporte de transição e/ou terapia profilática. Os tratamentos nao farmacológicos, quando associados ao farmacológico, ampliam a possibilidade de resultados satisfatórios, evitando recaídas.

  12. Intoxicación por Superwarfarinas

    OpenAIRE

    Patricia Crecente Otero; Jorge Luis Torres Triana; Ronald Macías Casanova; Luis Manuel Sánchez Rodríguez

    2012-01-01

    Las denominadas superwarfarinas se desarrollaron a partir de la década de 1970 como solución a las resistencias que habían desarrollado los roedores a los raticidas hasta entonces existentes1. Sus principales ventajas son su mayor potencia (hasta 100 veces más potentes que la warfarina)2 y el disponer de una semivida más larga (hasta 6-8 semanas). Presentamos el caso de un paciente varón que ingresa en nuestro servicio de Medicina Interna por otorragia y hematuria para estudio. Como único ant...

  13. Intoxicación ocupacional por mercurio

    OpenAIRE

    Augusto V Ramírez

    2008-01-01

    El mercurio, metal pesado ampliamente utilizado por el hombre, es muy tóxico; produce daño al sistema nervioso central, perturbaciones del comportamiento y lesiones renales. Se acumula en todos los seres vivos y no es esencial para ningún proceso biológico. La toxicidad del mercurio está directamente relacionada con su estado químico. El metilmercurio es la forma más dañina, con efectos neurotóxicos en adultos y en fetos de madres expuestas. El mercurio metálico no es menos tóxico. Las sales ...

  14. Refrigeración solar por eyector

    OpenAIRE

    Pizarro Romanillos, Raúl

    2014-01-01

    La finalidad de este trabajo es el estudio de un método de refrigeración que ayude a reducir el impacto medioambiental que producen otros sistemas de refrigeración más convencionales. Este método consiste en combinar la energía del Sol, que es renovable y gratuita, con un sistema de refrigeración por eyección que, a pesar de no tener alta eficiencia, tiene importantes ventajas como la de tener un bajo coste y una menor complejidad que otros sistemas. Para comenzar el estudio se hará un bre...

  15. Osteonecrosis de hueso maxilar inducida por bisfosfonatos

    OpenAIRE

    Vera Sempere, Francisco José

    2016-01-01

    Los bisfosfonatos son un grupo de fármacos, análogos de los pirofosfatos, utilizados en administración oral en el tratamiento de la osteoporosis, así como en formulaciones intravenosas para el tratamiento del dolor óseo y de la hipercalcemia ligada a la enfermedad tumoral metastasica (generalmente en el contexto de mieloma múltiple / cáncer de mama o próstata avanzados), actuando como un inhibidor de la reabsorción ósea, mediada por osteoclastos, así como de la apoptosis de los osteobl...

  16. Estudio del desgaste por deslizamiento en bronces

    OpenAIRE

    Carlos Holguín; John Coronado

    2007-01-01

    Se evaluaron tres bronces: SAE 67, nacional y americano usados típicamente como material de la chumacera en los molinos de caña de azúcar. Se realizaron pruebas desgaste por deslizamiento bajo la norma G77 usando bloques de bronce, anillos de acero SAE 1045 y aceite como lubricante. El tribómetro se calibró usando los anillos de acero SAE 4620 y se usó acero de herramienta SAE O1 para los bloques. Se realizaron metalografías, durezas y rugosidad de los materiales estudiados. El bronce naciona...

  17. Por uma arte no mundo da vida

    Directory of Open Access Journals (Sweden)

    Rachel Costa

    2016-12-01

    Full Text Available O artigo visa debater a análise colocada por Jacinto Lageira no texto “As razões do agir, contribuição a uma poética da ação”. O debate se estabelece no que concerne ao problema da autonomia da arte e suas consequências, tendo em vista a necessidade de pensar possibilidades contemporâneas para a experiência estética que pressuponham o mundo material. Isso é realizado a partir da teoria dos gestos do filósofo Vilém Flusser.

  18. Formação por ciclos

    OpenAIRE

    Nedbajluk,Lidia

    2006-01-01

    Artigo desenvolvido a partir dos estudos de Mestrado na Universidade Federal do Paraná, na linha de pesquisa Currículo, Conhecimento e Saberes nas Práticas Escolares, investigando a Formação por Ciclos. Analisa a diversidade de termos utilizados como complemento ao termo ciclos no ensino fundamental (Ciclos de Aprendizagem; Escola em Ciclos; Ensino em Ciclos; Ciclos de Desenvolvimento; Ciclos de Formação; Ciclo de Estudos) e esclarece a inadequação do uso dos mesmos indistintamente. Considera...

  19. Magnetospheric plasma waves

    International Nuclear Information System (INIS)

    Shawhan, S.D.

    1977-01-01

    A brief history of plasma wave observations in the Earth's magnetosphere is recounted and a classification of the identified plasma wave phenomena is presented. The existence of plasma waves is discussed in terms of the characteristic frequencies of the plasma, the energetic particle populations and the proposed generation mechanisms. Examples are given for which plasmas waves have provided information about the plasma parameters and particle characteristics once a reasonable theory has been developed. Observational evidence and arguments by analogy to the observed Earth plasma wave processes are used to identify plasma waves that may be significant in other planetary magnetospheres. The similarities between the observed characteristics of the terrestrial kilometric radiation and radio bursts from Jupiter, Saturn and possibly Uranus are stressed. Important scientific problems concerning plasma wave processes in the solar system and beyond are identified and discussed. Models for solar flares, flare star radio outbursts and pulsars include elements which are also common to the models for magnetospheric radio bursts. Finally, a listing of the research and development in terms of instruments, missions, laboratory experiments, theory and computer simulations needed to make meaningful progress on the outstanding scientific problems of plasma wave research is given. (Auth.)

  20. Particle beams and plasmas

    International Nuclear Information System (INIS)

    Hofmann, A.; Messerschmid, E.; Lawson, J.D.

    1976-01-01

    These lectures present a survey of some of the concepts of plasma physics and look at some situations familiar to particle-accelerator physicists from the point of view of a plasma physicist, with the intention of helping to link together the two fields. At the outset, basic plasma concepts are presented, including definitions of a plasma, characteristic parameters, magnetic pressure and confinement. This is followed by a brief discussion on plasma kinetic theory, non-equilibrium plasma, and the temperature of moving plasmas. Examples deal with beams in the CERN Intersecting Storage Rings as well as with non-steady beams in cyclic accelerators and microwave tubes. In the final chapters, time-varying systems are considered: waves in free space and the effect of cylinder bounds, wave motion in cold stationary plasmas, and waves in plasmas with well-defined streams. The treatment throughout is informal, with emphasis on the essential physical properties of continuous beams in accelerators and storage rings in relation to the corresponding problems in plasma physics and microwave tubes. (Author)

  1. Nodulose por Metotrexato Methotrexate Induced Nodulosis

    Directory of Open Access Journals (Sweden)

    Fernanda Guidolin

    2005-08-01

    Full Text Available A nodulose por metotrexato (MTX é um dos efeitos colaterais pouco conhecidos do uso desse medicamento em doses baixas. Embora classicamente descrita em casos de artrite reumatóide, tem aparecido, também, em outras doenças reumáticas. Descreve-se aqui um caso de nodulose por MTX em uma paciente com artrite reumatóide soropositiva, que utilizava esse medicamento há um ano, com bom controle do processo articular. Segue-se uma breve revisão sobre o assunto.Methotrexate-induced nodulosis is a rare side effect of this drug when it is used in low doses. Although classically described in rheumatoid arthritis patients, it may also appear in other rheumatic disorders. We describe a seropositive rheumatoid arthritis patient who developed methotrexate-induced nodulosis after using this drug for a year, with good control of articular symptoms. This case presentation is followed by a brief revision on the subject.

  2. Investigando o Consumo de Lazer por Idosos

    Directory of Open Access Journals (Sweden)

    Marcelo de Rezende Pinto

    2015-06-01

    Full Text Available A partir da constatação de que ainda são incipientes os estudos que buscam investigar a perspectiva cultural do consumo, atrelada à percepção de que pouco se pesquisou sobre o consumo de lazer de consumidores da terceira idade, o artigo tem por objetivo geral apresentar resultados de uma pesquisa empírica cujo objetivo foi investigar como as experiências de consumo nas atividades de lazer por indivíduos da terceira idade interagem com o sistema cultural e simbólico envolvido no fluxo da vida social cotidiana. Para se atingir esses objetivos, adotou-se uma perspectiva interpretativa de investigação, a partir de uma abordagem etnográfica. Os resultados parecem indicar que os processos sociais, desde a construção de relacionamentos entre familiares, amigos e vizinhos até a construção de redes de convivência com integrantes dos clubes de terceira constituem-se os principais processos presentes nas atividades de lazer desses indivíduos.

  3. Reacciones adversas por antiinflamatorios no esteroideos

    Directory of Open Access Journals (Sweden)

    Luisa Ivet Sánchez Ricardo

    2011-03-01

    Full Text Available Se realizó un estudio descriptivo y transversal en el Consultorio Médico de la Familia No. 28 perteneciente al Policlínico Universitario y Docente "Dr. Mario Muñoz Monroy" desde el 1ro. de junio al 31 de diciembre de 2008, con el objetivo de detectar las reacciones adversas más frecuentes provocadas por el consumo de antiinflamatorios no esteroideos. El universo estuvo constituido por 105 pacientes que asistieron a consulta en el tiempo de estudio y de estos se seleccionó una muestra de 60 pacientes, a quienes se les aplicó un cuestionario de preguntas donde se recogieron las variables de análisis. .Las mujeres resultaron las que más antiinflamatorios consumieron y en el rango de edades de 31-59 años. Las reacciones adversas que más se reportaron fueron la epigastralgia y la hipertensión arterial, así mismo se comprobó la automedicación en algunos pacientes.

  4. Hipotiroidismo inducido por Amiodarona: Reporte de caso

    Directory of Open Access Journals (Sweden)

    Jorge Luis Salinas Arce

    2012-03-01

    Full Text Available Se describe el caso de una mujer de 57 años de edad, con diagnóstico de síndrome de Wolf Parkinson White, en tratamiento con amiodarona 200 mg/día; que acudió por presentar palpitaciones, fatiga y aumento de sueño. Al examen físico no se encontró bocio, pero los reflejos osteotendinosos estaban prolongados. Los exámenes auxiliares mostraron TSH elevado, T4 libre disminuido y anticuerpos antiperoxidasa tiroidea negativos. Se suspendió la amiodarona y se inició levotiroxina. Después de dos meses; los niveles de TSH y T4 libre eran normales y la paciente no presentaba molestias. La amiodarona está asociada a diversos efectos adversos que pueden limitar su uso. Entre estos efectos adversos, se describe el hipotiroidismo inducido, que se caracteriza por TSH elevado, T4 libre disminuido y síntomas inespecíficos como fatiga, intolerancia al frío y piel seca. El tratamiento de elección es la levotiroxina.

  5. Introduction to complex plasmas

    International Nuclear Information System (INIS)

    Bonitz, Michael; Ludwig, Patrick; Horing, Norman

    2010-01-01

    Complex plasmas differ from traditional plasmas in many ways: these are low-temperature high pressure systems containing nanometer to micrometer size particles which may be highly charged and strongly interacting. The particles may be chemically reacting or be in contact with solid surfaces, and the electrons may show quantum behaviour. These interesting properties have led to many applications of complex plasmas in technology, medicine and science. Yet complex plasmas are extremely complicated, both experimentally and theoretically, and require a variety of new approaches which go beyond standard plasma physics courses. This book fills this gap presenting an introduction to theory, experiment and computer simulation in this field. Based on tutorial lectures at a very successful recent Summer Institute, the presentation is ideally suited for graduate students, plasma physicists and experienced undergraduates. (orig.)

  6. Introduction to Complex Plasmas

    CERN Document Server

    Bonitz, Michael; Ludwig, Patrick

    2010-01-01

    Complex plasmas differ from traditional plasmas in many ways: these are low-temperature high pressure systems containing nanometer to micrometer size particles which may be highly charged and strongly interacting. The particles may be chemically reacting or be in contact with solid surfaces, and the electrons may show quantum behaviour. These interesting properties have led to many applications of complex plasmas in technology, medicine and science. Yet complex plasmas are extremely complicated, both experimentally and theoretically, and require a variety of new approaches which go beyond standard plasma physics courses. This book fills this gap presenting an introduction to theory, experiment and computer simulation in this field. Based on tutorial lectures at a very successful recent Summer Institute, the presentation is ideally suited for graduate students, plasma physicists and experienced undergraduates.

  7. Nonideal plasmas - experimental research

    International Nuclear Information System (INIS)

    Guenther, K.; Hess, H.; Radtke, R.

    1986-01-01

    The investigation of nonideal, strongly coupled, or non-Debye plasmas is a new field of the well-known arc plasma physics. The increased pressure and density cause different behaviour of the dense plasma. The paper surveys the main differences between the nonideal and the usual arc plasmas. The electrical conductivity, continuum radiation absorption coefficient, shift and broadening of spectral lines, and plasma phase transition are discussed. The problems of generation and diagnostics of nonideal plasmas are also described. Finally, the importance of the topic is underlined: possible applications in astrophysics and in different fields of technology: light sources, MHD generators, circuit breakers, laser mirrors and shutters, high temperature gas-phase fission reactors, material treatment and laser fusion are mentioned. (D.Gy.)

  8. Thermal plasma waste treatment

    International Nuclear Information System (INIS)

    Heberlein, Joachim; Murphy, Anthony B

    2008-01-01

    Plasma waste treatment has over the past decade become a more prominent technology because of the increasing problems with waste disposal and because of the realization of opportunities to generate valuable co-products. Plasma vitrification of hazardous slags has been a commercial technology for several years, and volume reduction of hazardous wastes using plasma processes is increasingly being used. Plasma gasification of wastes with low negative values has attracted interest as a source of energy and spawned process developments for treatment of even municipal solid wastes. Numerous technologies and approaches exist for plasma treatment of wastes. This review summarizes the approaches that have been developed, presents some of the basic physical principles, provides details of some specific processes and considers the advantages and disadvantages of thermal plasmas in waste treatment applications. (topical review)

  9. Lucro por ação

    Directory of Open Access Journals (Sweden)

    Gabriel Moreira Campos

    2001-08-01

    Full Text Available Este trabalho tem por objetivo demonstrar os principais conceitos acerca do Lucro por Ação (Earnings per Share, o qual se apresenta como um quociente de grande utilidade nas entidades. Serão demonstrados aspectos sobre o assunto presentes no Brasil, bem como as normas aplicáveis nos Estados Unidos, emanadas do Financial Accounting Standards Board (FASB, e as normas internacionais, emanadas do International Accounting Standards Committee (IASC. De forma a possibilitar uma visualização mais completa dos conceitos envolvidos, serão desenvolvidos exemplos de sua aplicação. O Lucro (Resultado por Ação pode ser calculado em sua forma básica e em sua forma diluída. Na forma básica, não são considerados os efeitos dos instrumentos potencialmente dilutivos, ao passo que, no cálculo do Lucro (Resultado por Ação Diluído, são. Como instrumentos financeiros potencialmente dilutivos temos as ações preferenciais conversíveis, as debêntures conversíveis e os bônus de subscrição, que podem ser convertidos em ações ordinárias, caracterizando, assim, o próprio potencial dilutivo desses instrumentos. Dessa forma, o trabalho em questão foi dividido em três partes principais, sendo que nas duas últimas constam os referidos exemplos de cálculo do Lucro por Ação em sua forma básica e em sua forma diluída: • aspectos observados no Brasil; • normas emanadas do FASB; • normas emanadas do IASC.The objective of this paper is to demonstrate the principal concepts about Earnings per Share, which is presented as a quotient of great usefulness for the companies. The subject is presented in three parts: in the first part, we will demonstrate relevant aspects that are present in Brazil. In the second part, the applicable standards in the United States will be discussed, which are issued by the Financial Accounting Standards Board (FASB. In the third part, the international standards are dealt with, which are issued by the

  10. Estimative of genetic parameters in progeny test of Pinus caribaea Morelet var. hondurensis Barret & Golfari by quantitative traits and microsatellite markers Estimativas de parâmetros genéticos em teste de progênies de Pinus caribaea var. hondurensis por caracteres quantitativos e marcadores microssatélites

    Directory of Open Access Journals (Sweden)

    Evandro Vagner Tambarussi

    2010-01-01

    Full Text Available The aims of this work were to estimate the coefficient of relatedness within families and the genetic parameters for growth related traits in a progeny test from an open-pollinated variety of Pinus caribaea Morelet hondurensis Barret & Golfari, established in Mato Grosso do Sul State, Brazil. The experimental design was the triple 10 x 10 lattice, with 96 families, three replicates, and ten plants per plot. Fourteen years after planting, the trial was measured for the following traits: total height, diameter at breast height (DBH, and true volume. The estimation of coefficients of relatedness within family from microsatellite loci indicated that families are true half-sibs (^r xy = 0.253. Thus, the additive genetic variance (σ2A can be estimated assuming that the genetic variance among progenies (σ2p accounts for ¼ of additive genetic variance (^σ2A = 4^σ2p. The estimative of heritability coefficients at individual level (h i² was relatively high (0.28 for DBH and 0.44 for height. The heritability coefficient considering the average families (h m² was also high, ranging among the traits from 0.50 to 0.58. These results suggest that the population can be improved by both massal and among families selection. Additionally, the estimated genetic gains with sequential selection among and within families were high (ranging from 8.92% for height to 37.56% for volume, demonstrating that this method of selection can generate high genetic improvement.Os objetivos deste trabalho foram estimar o coeficiente de parentesco dentro de famílias e os parâmetros genéticos e fenotípicos para os caracteres de crescimento (altura, diâmetro a altura do peito e volume em um teste de progênies de polinização aberta de Pinus caribaea Morelet var. hondurensis Barret & Golfari, implantado no Estado de Mato Grosso do Sul, Brasil. O teste foi implantado em látice 10 x 10 triplo, com 96 famílias, três repetições e dez plantas por parcela. Quatorze anos ap

  11. Compression of toroidal plasma by imploding plasma-liner

    International Nuclear Information System (INIS)

    Ikuta, Kazunari.

    1979-07-01

    A new concept of compressing a plasma in a closed magnetic configuration by a version of liner implosion flux compression technique is considered. The liner consists of a dense plasma cylinder, i.e. the plasma-liner. Maximum compression ratio of toroidal plasma is determined just by the initial density ratio of the toroidal plasma to the liner plasma because of the Rayleigh-Taylor instability. A start-up senario of plasma-liner is also proposed with a possible application of this concept to the creation of a burning plasma in reversed field configurations, i.e. burning plasma vortex. (author)

  12. Space plasmas 2

    International Nuclear Information System (INIS)

    Frankel, N.E.; Hines, K.C.; Kowalenko, V.

    1981-01-01

    The longitudinal dielectric response of an ultra-degenerate relativistic plasma composed of electrons and positrons is considered. The relativistic Hartree self-consistent field method is used to investigate the dispersion relations and damping parameters of such a plasma in the presence of a magnetic field. These properties must be studied in the various regimes appropriate for a relativistic plasma as detailed by Tsytovich and Jancovici

  13. Plasma polarization spectroscopy

    International Nuclear Information System (INIS)

    Iwamae, Atsushi; Horimoto, Yasuhiro; Fujimoto, Takashi; Hasegawa, Noboru; Sukegawa, Kouta; Kawachi, Tetsuya

    2005-01-01

    The electron velocity distribution function (EVDF) in plasma can be anisotropic in laser-produced plasmas. We have developed a new technique to evaluate the polarization degree of the emission lines in the extreme vacuum ultra violet wavelength region. The polarization of the emission lines and the continuums from the lithium-like nitrogen and from helium- and hydrogen-like carbon in recombining plasma is evaluated. Particle simulation in the velocity space gives the time scale for relaxation of anisotropic EVDFs. (author)

  14. Plasma nitriding of steels

    CERN Document Server

    Aghajani, Hossein

    2017-01-01

    This book focuses on the effect of plasma nitriding on the properties of steels. Parameters of different grades of steels are considered, such as structural and constructional steels, stainless steels and tools steels. The reader will find within the text an introduction to nitriding treatment, the basis of plasma and its roll in nitriding. The authors also address the advantages and disadvantages of plasma nitriding in comparison with other nitriding methods. .

  15. Cyclotron waves in plasma

    International Nuclear Information System (INIS)

    Lominadse, D.G.

    1975-01-01

    The book deals with fundamental physical concepts of the theory of cyclotron waves and cyclotron instabilities conditioned by the presence in plasma of direct or alternating electric currents passing in it perpendicularily to a magnetic field. A great variety of problems is considered connected with the linear theory of cyclotron oscillations in equilibrium and electron plasma of metals and semiconductors. Parametric excitations of electron cyclotron oscillations of plasma in an alternating electric field are studied. Particular attention is paid to the investigation of plasma turbulence arising as a result of development of cyclotron instabilities. Experimental data are discussed and compared with theoretical results

  16. Princeton Plasma Physics Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    1990-01-01

    This report discusses the following topics: principal parameters achieved in experimental devices fiscal year 1990; tokamak fusion test reactor; compact ignition tokamak; Princeton beta experiment- modification; current drive experiment-upgrade; international collaboration; x-ray laser studies; spacecraft glow experiment; plasma processing: deposition and etching of thin films; theoretical studies; tokamak modeling; international thermonuclear experimental reactor; engineering department; project planning and safety office; quality assurance and reliability; technology transfer; administrative operations; PPPL patent invention disclosures for fiscal year 1990; graduate education; plasma physics; graduate education: plasma science and technology; science education program; and Princeton Plasma Physics Laboratory reports fiscal year 1990.

  17. Princeton Plasma Physics Laboratory

    International Nuclear Information System (INIS)

    1990-01-01

    This report discusses the following topics: principal parameters achieved in experimental devices fiscal year 1990; tokamak fusion test reactor; compact ignition tokamak; Princeton beta experiment- modification; current drive experiment-upgrade; international collaboration; x-ray laser studies; spacecraft glow experiment; plasma processing: deposition and etching of thin films; theoretical studies; tokamak modeling; international thermonuclear experimental reactor; engineering department; project planning and safety office; quality assurance and reliability; technology transfer; administrative operations; PPPL patent invention disclosures for fiscal year 1990; graduate education; plasma physics; graduate education: plasma science and technology; science education program; and Princeton Plasma Physics Laboratory reports fiscal year 1990

  18. Plasma processing for VLSI

    CERN Document Server

    Einspruch, Norman G

    1984-01-01

    VLSI Electronics: Microstructure Science, Volume 8: Plasma Processing for VLSI (Very Large Scale Integration) discusses the utilization of plasmas for general semiconductor processing. It also includes expositions on advanced deposition of materials for metallization, lithographic methods that use plasmas as exposure sources and for multiple resist patterning, and device structures made possible by anisotropic etching.This volume is divided into four sections. It begins with the history of plasma processing, a discussion of some of the early developments and trends for VLSI. The second section

  19. Nonlinear Physics of Plasmas

    CERN Document Server

    Kono, Mitsuo

    2010-01-01

    A nonlinearity is one of the most important notions in modern physics. A plasma is rich in nonlinearities and provides a variety of behaviors inherent to instabilities, coherent wave structures and turbulence. The book covers the basic concepts and mathematical methods, necessary to comprehend nonlinear problems widely encountered in contemporary plasmas, but also in other fields of physics and current research on self-organized structures and magnetized plasma turbulence. The analyses make use of strongly nonlinear models solved by analytical techniques backed by extensive simulations and available experiments. The text is written for senior undergraduates, graduate students, lecturers and researchers in laboratory, space and fusion plasmas.

  20. The plasma universe

    International Nuclear Information System (INIS)

    Faelthammar, C.G.

    1989-12-01

    The term 'Plasma Universe', coined by Hannes Alfven, emphasices the fact that plasma phenomena discovered in the laboratory and in accessible regions of space. must be important also in the rest of the universe, which consists almost entirely of matter in the plasma state. Relevant aspect of this concept will be discussed. They include the response of the plasma to electric currents, the support of magnetic-field aligned electric fields, violation of the frozen-field condition, rapid release of magnetically stored energy, acceleration of charged particles, chemical separation, and filamentary and cellular structures. (authors)

  1. The plasma physics of plasma processing

    International Nuclear Information System (INIS)

    Shohet, L.

    1991-01-01

    Plasma processing is used for producing new materials with unusual and superior properties, for developing new chemical compounds and processes, for machining, and for altering and refining materials and surfaces. It has direct applications to semiconductor fabrication, materials synthesis, welding, lighting, polymers, anti-corrosion coatings, machine tools, metallurgy, electrical and electronics devices, hazardous waste removal, high performance ceramics, and many other items in both high-technology and the more traditional industries. Plasma processing takes on a wide variety of apparently different forms in industry, but the techniques share many common characteristics and problems. Control of the generation and flux of ions, electrons and free radicals in the plasma and their incidence on a surface is vital. Diagnostics, sensors, modeling techniques, and associated statistical methods are needed. However, without an in-depth understanding of the variety of phenomena taking place and their application to the industrial environment, advances in this technology, and its efficient use, will occur at a diminishing rate

  2. Similaridade genética entre clones de seringueira (Hevea brasiliensis, por meio de marcadores RAPD Genetic similarity among rubber tree (Hevea brasiliensis clones using RAPD markers

    Directory of Open Access Journals (Sweden)

    Karine Cristina Bicalho

    2008-10-01

    Full Text Available A seringueira [Hevea brasiliensis (Willd. ex. Adr. de Juss Muell.-Arg.] é uma espécie nativa da região amazônica e compreende a maior fonte produtora de borracha natural do mundo. Na busca de condições mais favoráveis ao cultivo, além da busca pela auto-suficiência na produção de borracha natural, o cultivo da seringueira migrou para outras regiões do país. Objetivou-se, com o presente trabalho, estimar a similaridade genética de genótipos de seringueira, provenientes de regiões distintas do país, Lavras-MG (UFLA e Campinas-SP (IAC, por meio de marcadores moleculares RAPD. A análise foi efetuada em 41 indivíduos, representados por 17 genótipos diferentes, com base em 19 primers, que geraram 121 fragmentos polimórficos. Os dados foram analisados utilizando o software NTSYS-pc - 2.1, por meio do coeficiente de Dice e pelo método das médias (UPGMA. A similaridade genética entre o material analisado variou de 0,56 a 1,00. Na análise do dendrograma, foram observados 18 grupos. Os clones (RRIM600, GT1, PB235, PL PIM e FX2261, utilizados em diferentes repetições, foram idênticos, quando comparados entre si, entretanto o mesmo não foi observado para os clones identificados como RRIM 701. Os resultados obtidos sugerem que o material avaliado na UFLA é o mesmo implantado no IAC, exceto o RRIM 701, mostrando uma ampla variabilidade genética, disponível para estudos e propagação da cultura.The rubber tree [Hevea brasiliensis (Willd. ex. Adr. de Juss Muell.-Arg.] is a native species from Amazon region, and represents the biggest source of natural rubber in the world.. However, the rubber tree culture has had an expansion to other brazilian regions, in search of more favorable conditions for its cultivation and self-sufficiency in natural rubber. The aim of this work was to estimate genetic similarity among rubber tree clones, from different Brazilian regions, Lavras (UFLA and Campinas (IAC, by using RAPD molecular markers

  3. Substituição de uréia por cloreto de amônio em dietas de bovinos: digestibilidade, síntese de proteína microbiana, parâmetros ruminais e sanguíneos - DOI: 10.4025/actascianimsci.v31i3.5938 Replacing urea with ammonium chloride in cattle diets: digestibility, synthesis of microbial protein, and rumen and plasma parameters - DOI: 10.4025/actascianimsci.v31i3.5938

    Directory of Open Access Journals (Sweden)

    Julio Cesar Barreto

    2009-09-01

    Full Text Available Foram utilizados cinco bovinos machos, castrados, da raça Holandesa Preta e Branca, com 450 kg de peso vivo em um delineamento quadrado latino 5 x 5, sendo os tratamentos cinco níveis de substituição, 0, 25, 50, 75 e 100% de ureia por cloreto de amônio, como fontes de nitrogênio não-proteico da dieta. Houve redução linear (p 0,05 a excreção de alantoína e de derivados de purinas na urina, purinas absorvidas, síntese de compostos nitrogenados microbianos e eficiência de síntese de proteína microbiana. Houve queda linear (p 0,05 a concentração de amônia no rúmen. O cloreto de amônio pode ser utilizado como fonte de NNP para bovinos em níveis de até 1,4% da matéria seca total da dieta.Five Holstein steers weighting 450 kg were used in a 5 x 5 Latin square statistical design, where treatments consisted of five replacement levels: 0, 25, 50, 75 and 100% of urea by ammonium chloride, as non-protein nitrogen in the diet. There was a linear decrease (p 0.05 daily excretion of allantoin, purine derivatives, absorbed purines, as well as microbial nitrogen compounds and microbial efficiency synthesis. Rumen pH and plasma urea nitrogen decreased linearly (p 0.05 ruminal ammonia concentration as urea was replaced by ammonium chloride. Ammonium chloride can be used as a non-protein nitrogen source in ruminant diets up to level of 1.4% of diet dry matter.

  4. La Violencia Latinoamericana vista por los Economistas

    Directory of Open Access Journals (Sweden)

    Salama Pierre

    2003-08-01

    Full Text Available

    Salama, Pierre. "La Violencia Lationoamericana vista por los Economistas", Cuadernos de Economía, V. XXII, n. 38, Bogotá, 2003 páginas 179-198.

    Este articulo sintetiza los estudios económicos publicados recientemente sobre la violencia en América Latina y analiza las causas suceptibles a acrecentarla: pobreza, desigualdad de los ingresos en nivel y variación, impunidad, diferencia entre la probabilidad de ser arrestado y la severidad de la pena impuesta, y narcotrafico. Sin embargo, la explicación de la violencia no se limitará a los factores económicos, puesto que el autor privilegia un enfoque inspirado en la antropología y la sociología.

  5. Toxicidad por óxido de etileno

    Directory of Open Access Journals (Sweden)

    Téllez M. Jairo A.

    1993-08-01

    Full Text Available

    El óxido de etileno, es un compuesto epóxido gaseoso, ampliamente utilizado en nuestro medio como agente esterilizante y de desinfección en instituciones hospitalarias. Los estudios realizados en varios países han demostrado efectos sobre la salud humana, caracterizados por  hipersensibilidad dérmica, irritación del tracto respiratorio, irritación ocular, excitación del S.N.C. y se asocia con presencia de abortos expontáneos, aberraciones cromosómicas e irritación crónica de laringe y tráquea en personal expuesto ocupacionalmente.

  6. Infeções alimentares por Campylobacter

    OpenAIRE

    Neto, Carlota Duarte Castro

    2017-01-01

    Dissertação para obtenção do grau de Mestre no Instituto Superior de Ciências da Saúde Egas Moniz Após o isolamento bem-sucedido em fezes na década de setenta do século passado (1972), Campylobacter tornou-se rapidamente a espécie bacteriana mais comumente associada a doenças diarreicas em todo o mundo. A infeção por Campylobacter provoca um espectro de doenças, incluindo enterite aguda, infeções extra-gastrointestinais e complicações pós-infeciosas. A doença gastrointestinal autolimita...

  7. fluidizado por proceso autotérmico

    Directory of Open Access Journals (Sweden)

    ZULAMITA ZAPATA BENABITHE

    2005-01-01

    Full Text Available El presente trabajo se basa en el estudio de la producción de carbón activado a partir de carbón mineral subbituminoso en un reactor de lecho fluidizado por proceso autotérmico. El carbón utilizado provino de la región de Amagá (Antioquia - Colombia y fue activado en dos reactores de lecho fluidizado de diferente diámetro interno, 10 cm y 22 cm. Los valores del área superficial específica y el volumen de poro de las muestras activadas fueron determinados a partir de las isotermas de N2 y CO2. Los resultados experimentales mostraron que los valores de áreas superficiales BET y DR y del Índice de Yodo se encontraron alrededor de 460 m2/g (SBET, 490 m2/g (SDR y 460 mg I2/g carbón.

  8. Plasma Physics An Introduction to Laboratory, Space, and Fusion Plasmas

    CERN Document Server

    Piel, Alexander

    2010-01-01

    Plasma Physics gives a comprehensive introduction to the basic processes in plasmas and demonstrates that the same fundamental concepts describe cold gas-discharge plasmas, space plasmas, and hot fusion plasmas. Starting from particle drifts in magnetic fields, the principles of magnetic confinement fusion are explained and compared with laser fusion. Collective processes are discussed in terms of plasma waves and instabilities. The concepts of plasma description by magnetohydrodynamics, kinetic theory, and particle simulation are stepwise introduced. Space charge effects in sheath regions, double layers and plasma diodes are given the necessary attention. The new fundamental mechanisms of dusty plasmas are explored and integrated into the framework of conventional plasmas. The book concludes with a brief introduction to plasma discharges. Written by an internationally renowned researcher in experimental plasma physics, the text keeps the mathematical apparatus simple and emphasizes the underlying concepts. T...

  9. EDITORIAL: Plasma jets and plasma bullets Plasma jets and plasma bullets

    Science.gov (United States)

    Kong, M. G.; Ganguly, B. N.; Hicks, R. F.

    2012-06-01

    Plasma plumes, or plasma jets, belong to a large family of gas discharges whereby the discharge plasma is extended beyond the plasma generation region into the surrounding ambience, either by a field (e.g. electromagnetic, convective gas flow, or shock wave) or a gradient of a directionless physical quantity (e.g. particle density, pressure, or temperature). This physical extension of a plasma plume gives rise to a strong interaction with its surrounding environment, and the interaction alters the properties of both the plasma and the environment, often in a nonlinear and dynamic fashion. The plasma is therefore not confined by defined physical walls, thus extending opportunities for material treatment applications as well as bringing in new challenges in science and technology associated with complex open-boundary problems. Some of the most common examples may be found in dense plasmas with very high dissipation of externally supplied energy (e.g. in electrical, optical or thermal forms) and often in or close to thermal equilibrium. For these dense plasmas, their characteristics are determined predominantly by strong physical forces of different fields, such as electrical, magnetic, thermal, shock wave, and their nonlinear interactions [1]. Common to these dense plasma plumes are significant macroscopic plasma movement and considerable decomposition of solid materials (e.g. vaporization). Their applications are numerous and include detection of elemental traces, synthesis of high-temperature materials and welding, laser--plasma interactions, and relativistic jets in particle accelerators and in space [2]-[4]. Scientific challenges in the understanding of plasma jets are exciting and multidisciplinary, involving interweaving transitions of all four states of matter, and their technological applications are wide-ranging and growing rapidly. Using the Web of Science database, a search for journal papers on non-fusion plasma jets reveals that a long initial phase up

  10. Geospace Plasma Dynamics

    Science.gov (United States)

    2013-05-22

    perturbations. High-speed solar wind streams cause recurrent geomagnetic activity and ionospheric disturbances. In [5], we analyze the equatorial...over eight successive orbits (~12 hours). A clear pre- reversal enhancement of upward plasma drift occurred between 18:00 and 19:00 LT when plasma

  11. Introduction to Plasma Spectroscopy

    CERN Document Server

    Kunze, H-J

    2009-01-01

    Based on lectures given at the Ruhr-University of Bochum for graduate students and postgraduates starting in plasma physics as well as from low- to high-density hot plasmas, this book introduces basic ideas and fundamental concepts and typical instrumentation from the X-ray to the infrared spectral regions

  12. General Relativistic Plasma Dynamics

    NARCIS (Netherlands)

    Moortgat, J.B.

    2006-01-01

    In this thesis I discuss the importance of general relativity on plasma physics in several astrophysical and cosmological contexts. The first chapters show how gravitational waves can excite all three fundamental low frequency magnetohydrodynamic plasma modes, the Alfven, slow and fast

  13. Atoms in dense plasmas

    International Nuclear Information System (INIS)

    More, R.M.

    1986-01-01

    Recent experiments with high-power pulsed lasers have strongly encouraged the development of improved theoretical understanding of highly charged ions in a dense plasma environment. This work examines the theory of dense plasmas with emphasis on general rules which govern matter at extreme high temperature and density. 106 refs., 23 figs

  14. Waves in unmagnetized plasma

    International Nuclear Information System (INIS)

    Lambert, A.J.D.

    1979-01-01

    A review of linear and weakly non-linear theory of electron waves, ion waves and electromagnetic waves in plasmas is presented. The author restricts the discussion to an infinitely extended, homogeneous and isotropic plasma, not affected by external fields and described by Vlasov's and Maxwell's equations. (Auth.)

  15. Plasma processing and chemistry

    NARCIS (Netherlands)

    Schram, D.C.

    2002-01-01

    A review. Plasma deposition and plasma conversion can be characterized by five steps: prodn. by ionization, transfer of chem. to precursors, transport of radicals to the surface, surface interactions with deposition, recirculation and generation of new monomers. For very fast deposition, large flows

  16. Plasma technology directory

    International Nuclear Information System (INIS)

    Ward, P.P.; Dybwad, G.L.

    1995-01-01

    The Plasma Technology Directory has two main goals: (1) promote, coordinate, and share plasma technology experience and equipment within the Department of Energy; and (2) facilitate technology transfer to the commercial sector where appropriate. Personnel are averaged first by Laboratory and next by technology area. The technology areas are accelerators, cleaning and etching deposition, diagnostics, and modeling

  17. Atoms in dense plasmas

    Energy Technology Data Exchange (ETDEWEB)

    More, R.M.

    1986-01-01

    Recent experiments with high-power pulsed lasers have strongly encouraged the development of improved theoretical understanding of highly charged ions in a dense plasma environment. This work examines the theory of dense plasmas with emphasis on general rules which govern matter at extreme high temperature and density. 106 refs., 23 figs.

  18. Microwave plasma mode conversion

    International Nuclear Information System (INIS)

    Torres, H.S.; Sakanaka, P.H.; Villarroel, C.H.

    1985-01-01

    The behavior of hot electrons during the process of laser-produced plasma is studied. The basic equations of mode conversion from electromagnetic waves to electrostatic waves are presented. It is shown by mode conversion, that, the resonant absorption and parametric instabilities appear simultaneously, but in different plasma regions. (M.C.K.) [pt

  19. Polychromatic holographic plasma diagnostics

    International Nuclear Information System (INIS)

    Zhiglinskij, A.G.; Morozov, A.O.

    1992-01-01

    Review of holographic interferometry properties is performed and advantages of this method by plasma diagnostics are indicated. Main results obtained by the method of holographic interferometry in studies of various-type plasmas are considered. Special attention is paid to multiwave plasma diagnostics, the necessity of which is related as a rule to multicomponent composition of plasma. The eight laser and gas-discharge sources and holographic schemes, which make it possible to realize plasma polychromatic and holographic interferometry, are considered. The advantages of the method are demonstrated by examples of polychromatic holographic diagnostics of arc discharge and discharge in a hollow cathode. Review of theoretical works determining the applicability area of resonance polychromatic interferometry is carried out

  20. Chaotic phenomena in plasmas

    International Nuclear Information System (INIS)

    Kawai, Y.

    1991-08-01

    It has recently been recognized that the research on various aspects of chaotic dynamics grows rapidly as one of some areas in nonlinear science. On the other hands, the plasma has long been called a treasure-house of nonlinear phenomena, so it is easy to imagine that the plasma is abundant in chaotic phenomena. In fact, the research on plasma chaos is going on, such as the research on the stochastic magnetic field and the chaotic orbit in the toroidal helical system, as well as the research in other experiments. To review the present status of the research on plasma chaos and to make clear the basic common physics, a working group was organized in 1990 as a collaboration research of National Institute for Fusion Science. This is the report on its activity in 1990, with a stress on experimental data obtained in basic plasma experiments and RFP, and on the relaxed theories and computer simulations. (author)

  1. Plasma based accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Caldwell, Allen [Max-Planck-Institut fuer Physik, Muenchen (Germany)

    2015-05-01

    The concept of laser-induced plasma wakefields as a technique to accelerate charged particles was introduced 35 years ago as a means to go beyond the accelerating gradients possible with metallic cavities supporting radio frequency electromagnetic fields. Significant developments in laser technology have made possible the pulse intensity needed to realize this concept, and rapid progress is now underway in the realization of laser-driven plasma wakefield acceleration. It has also been realized that similar accelerating gradients can be produced by particle beams propagating in plasmas, and experimental programs have also been undertaken to study this possibility. Positive results have been achieved with electron-driven plasma wakefields, and a demonstration experiment with proton-driven wakefields is under construction at CERN. The concepts behind these different schemes and their pros and cons are described, as well as the experimental results achieved. An outlook for future practical uses of plasma based accelerators will also be given.

  2. Solar system plasma waves

    Science.gov (United States)

    Gurnett, Donald A.

    1995-01-01

    An overview is given of spacecraft observations of plasma waves in the solar system. In situ measurements of plasma phenomena have now been obtained at all of the planets except Mercury and Pluto, and in the interplanetary medium at heliocentric radial distances ranging from 0.29 to 58 AU. To illustrate the range of phenomena involved, we discuss plasma waves in three regions of physical interest: (1) planetary radiation belts, (2) planetary auroral acceleration regions and (3) the solar wind. In each region we describe examples of plasma waves that are of some importance, either due to the role they play in determining the physical properties of the plasma, or to the unique mechanism involved in their generation.

  3. Plasma-material interactions

    International Nuclear Information System (INIS)

    Wilson, K.L.

    1984-01-01

    Plasma-interactive components must be resistant to erosion processes, efficient in heat removal, and effective in minimizing tritium inventory and permeation. As long as plasma edge temperatures are 50 eV, no one material can satisfy the diverse requirements imposed by these plasma materials interactions. The only solution is the design of duplex, or even more complicated, structures. The material that faces the plasma should be low atomic number, with acceptable erosion and evaporation characteristics. The substrate material must have high thermal conductivity for heat removal. Finally, materials must be selected judiciously for tritium compatibility. In conclusion, materials play a critical role in the achievement of safe and economical magnetic fusion energy. Improvements in materials have already led to many advances in present day device operation, but additional innovative materials solutions are required for the critical plasma materials interaction issues in future power reactors

  4. SUPERFAST THERMALIZATION OF PLASMA

    Science.gov (United States)

    Chang, C.C.

    1962-06-12

    A method is given for the superfast thermalization of plasma by shock conversion of the kinetic energy stored in rotating plasma rings or plasmoids colliding at near supersonic speeds in a containment field to heat energy in the resultant confined plasma mass. The method includes means for generating rotating plasmoids at the opposite ends of a Pyrotron or Astron containment field. The plasmoids are magnetically accelerated towards each other into the opposite ends of time containment field. During acceleration of the plasmoids toward the center of the containment field, the intensity of the field is sequentially increased to adiabatically compress the plasmoids and increase the plasma energy. The plasmoids hence collide with a violent shock at the eenter of the containment field, causing the substantial kinetic energy stored in the plasmoids to be converted to heat in the resultant plasma mass. (AEC)

  5. Antimatter plasmas and antihydrogen

    International Nuclear Information System (INIS)

    Greaves, R.G.; Surko, C.M.

    1997-01-01

    Recent successes in confining antimatter in the form of positron and antiproton plasmas have created new scientific and technological opportunities. Plasma techniques have been the cornerstone of experimental work in this area, and this is likely to be true for the foreseeable future. Work by a number of groups on trapping antimatter plasmas is summarized, and an overview of the promises and challenges in this field is presented. Topics relating to positron plasmas include the use of positrons to study the unique properties of electron endash positron plasmas, the interaction between positrons and ordinary matter, and the laboratory modeling of positron-annihilation processes in interstellar media. The availability of cold, trapped antiprotons and positrons makes possible the production of neutral antimatter in the form of antihydrogen. This is expected to enable precise comparisons of the properties of matter and antimatter, including tests of fundamental symmetries and the measurement of the interaction of antimatter with gravity. copyright 1997 American Institute of Physics

  6. A new large-scale plasma source with plasma cathode

    International Nuclear Information System (INIS)

    Yamauchi, K.; Hirokawa, K.; Suzuki, H.; Satake, T.

    1996-01-01

    A new large-scale plasma source (200 mm diameter) with a plasma cathode has been investigated. The plasma has a good spatial uniformity, operates at low electron temperature, and is highly ionized under relatively low gas pressure of about 10 -4 Torr. The plasma source consists of a plasma chamber and a plasma cathode generator. The plasma chamber has an anode which is 200 mm in diameter, 150 mm in length, is made of 304 stainless steel, and acts as a plasma expansion cup. A filament-cathode-like plasma ''plasma cathode'' is placed on the central axis of this source. To improve the plasma spatial uniformity in the plasma chamber, a disk-shaped, floating electrode is placed between the plasma chamber and the plasma cathode. The 200 mm diameter plasma is measure by using Langmuir probes. As a result, the discharge voltage is relatively low (30-120 V), the plasma space potential is almost equal to the discharge voltage and can be easily controlled, the electron temperature is several electron volts, the plasma density is about 10 10 cm -3 , and the plasma density is about 10% variance in over a 100 mm diameter. (Author)

  7. Plasma sheath criterion in thermal electronegative plasmas

    International Nuclear Information System (INIS)

    Ghomi, Hamid; Khoramabadi, Mansour; Ghorannevis, Mahmod; Shukla, Padma Kant

    2010-01-01

    The sheath formation criterion in electronegative plasma is examined. By using a multifluid model, it is shown that in a collisional sheath there will be upper as well as lower limits for the sheath velocity criterion. However, the parameters of the negative ions only affect the lower limit.

  8. Valoración del profesorado de magisterio sobre el aprendizaje basado en competencias implantado

    Directory of Open Access Journals (Sweden)

    Aurelio Villa

    2013-01-01

    Full Text Available A partir del curso académico 2010 - 11 se ha iniciado en Europa de modo oficial el Espacio Europeo de Educación Superior (EEES, y con él la puesta en marcha de las denominadas titulaciones Bolonia bajo la etiqueta del crédito europeo (European Credit Transf er System, ECTS. Este artículo trata de presentar el nivel de desarrollo del aprendizaje basado en competencias de las titulaciones de magisterio en España. A través de una metodología denominada Análisis Importancia - Realización (AIR (Martilla, J.A. y J ames, J.L., 1977 con la que se pretende dibujar la valoración que el profesorado y responsables académicos de magisterio realizan sobre el aprendizaje basado en competencias (ABC, y extraer las principales conclusiones del estudio empírico llevado a cabo en una muestra de 145 personas (profesores y gestores. Se presentan los resultados de un análisis factorial con cinco factores que describen el proceso de enseñanza - aprendizaje: planificación de competencias, gestión pedagógica, coordinación docente, tut oría y evaluación, y finalmente, revisión y mejora. Estos factores se correlacionaron con la formación recibida para iniciar el EEES y con el uso de la lección magistral. Obteniendo ambas variables correlaciones significativas. Este artículo se enriquece con otro artículo complementario que recoge la perspectiva cualitativa del profesorado sobre su visión de la implementación del proceso europeo y sus dificultades.

  9. Proceedings of the thirty second national symposium on plasma science and technology: plasma for societal benefits: book of abstracts

    International Nuclear Information System (INIS)

    Dave, Sandhya; Shravan Kumar, S.; Vijayakumaran; Singh, Raj; Awasthi, L.M.

    2017-01-01

    This symposium covers topics on: basic plasma, computer modelling for plasma, exotic plasma, industrial plasma, laser plasma theory, nuclear fusion, plasma diagnostics, laser plasma, plasma processing, pulsed power, space and astrophysical plasma. Papers relevant to INIS are indexed separately

  10. Plasma physics an introduction to laboratory, space, and fusion plasmas

    CERN Document Server

    Piel, Alexander

    2017-01-01

    The enlarged new edition of this textbook provides a comprehensive introduction to the basic processes in plasmas and demonstrates that the same fundamental concepts describe cold gas-discharge plasmas, space plasmas, and hot fusion plasmas. Starting from particle drifts in magnetic fields, the principles of magnetic confinement fusion are explained and compared with laser fusion. Collective processes are discussed in terms of plasma waves and instabilities. The concepts of plasma description by magnetohydrodynamics, kinetic theory, and particle simulation are stepwise introduced. Space charge effects in sheath regions, double layers and plasma diodes are given the necessary attention. The novel fundamental mechanisms of dusty plasmas are explored and integrated into the framework of conventional plasmas. The book concludes with a concise description of modern plasma discharges. Written by an internationally renowned researcher in experimental plasma physics, the text keeps the mathematical apparatus simple a...

  11. Autoagresión por quemaduras

    Directory of Open Access Journals (Sweden)

    Iris Montes de Oca

    1996-04-01

    Full Text Available Se realizó un estudio epidemiológico transversal en los casos de autoagresión por quemaduras, que acudieron al Cuerpo de Guardia del Servicio de Quemados del Hospital "Dr. Ernesto Guevara de la Serna", durante el período comprendido entre los meses de febrero de 1993 y febrero de 1994, con la finalidad de determinar el comportamiento de algunas variables de interés en estos casos. El universo de estudio lo constituyeron 57 casos, cuya información se recolectó de la gráfica general del paciente quemado (Modelo 71-05 y de los registros estadísticos del Servicio de Quemados del Hospital. Como fundamentales resultados y conclusiones se obtienen las siguientes: la mayor frecuencia de casos se encontró en las edades comprendidas entre 15 y 24 años; el sexo femenino resultó ser el más afectado en todos los grupos de edades. La cocina fue el lugar donde se efectuó el acto con mayor frecuencia. Se encontró un alto grado de asociación entre la supervivencia y la presencia de antecedentes de intentos suicidas. Presentaron la mayor incidencia por municipios los de Puerto Padre y Jobabo; el alcohol y el kerosene fueron los agentes causales más utilizados. En la casuística predominaron los grandes quemados.A transversal epidemiological study of the cases of self-aggression by burns, who received medical attention at the Emergency Department of the Burns Service of the "Dr. Ernesto Guevara de la Serna" Hospital from February, 1993 to February, 1994, was carried out aimed at determining the behaviour of some variables of interest in these cases. Fifty seven cases were studied and the information was collected from the general graph of the burn patient (Model 71-05, and from the statistical records of the Burns Service of the hospital. The main results and conclusions reached are the following: the highest frequency of cases was found in ages between 15 and 24; women were the most affected in all age groups; and kitchen was the place where the

  12. Waves in Space Plasmas Program

    Science.gov (United States)

    Fredricks, R. W.; Taylor, W. W. L.

    1981-01-01

    The Waves in Space Plasmas (WISP) program is a joint international effort involving instrumentation to be designed and fabricated by funding from NASA and the National Research Council of Canada. The instrumentation, with a tentatively planned payload for 1986, can be used to perturb the plasma with radio waves to solve problems in ionospheric, atmospheric, magnetospheric, and plasma physics. Among the ionospheric and plasma phenomena to be investigated using WISP instrumentation are VLF wave-particle interactions; ELF/VLF propagation; traveling ionospheric disturbances and gravity wave coupling; equatorial plasma bubble phenomena; plasma wave physics such as mode-coupling, dispersion, and instabilities; and plasma physics of the antenna-plasma interactions.

  13. Waves in Space Plasmas Program

    International Nuclear Information System (INIS)

    Fredricks, R.W.; Taylor, W.W.L.

    1981-01-01

    The Waves in Space Plasmas (WISP) program is a joint international effort involving instrumentation to be designed and fabricated by funding from NASA and the National Research Council of Canada. The instrumentation, with a tentatively planned payload for 1986, can be used to perturb the plasma with radio waves to solve problems in ionospheric, atmospheric, magnetospheric, and plasma physics. Among the ionospheric and plasma phenomena to be investigated using WISP instrumentation are VLF wave-particle interactions, ELF/VLF propagation, traveling ionospheric disturbances and gravity wave coupling, equatorial plasma bubble phenomena, plasma wave physics such as mode-coupling, dispersion, and instabilities, and plasma physics of the antenna-plasma interactions

  14. Nefrectomía simple por puerto único (LESS) asistida por robot (da Vinci)

    OpenAIRE

    CASTILLO C,OCTAVIO A; VIDAL M,IVAR; SEPÚLVEDA T,FRANCISCO

    2011-01-01

    Introducción: La cirugía mínimamente invasiva en urología avanza rápidamente y la cirugía laparo-endoscópica a través de puerto único (LESS) no es la excepción. Esta técnica por vía laparoscópica presenta mucha dificultad y requiere de un cirujano laparoscópico experimentado debido a la falta de triangulación y el cruce de los instrumentos. Los beneficios del sistema quirúrgico da Vinci® han sido introducidos recientemente en LESS. Presentamos dos casos de nefrectomía LESS asistida por robot....

  15. Consumo Voluntario de Forraje por Rumiantes en Pastoreo Consumo Voluntario de Forraje por Rumiantes en Pastoreo

    Directory of Open Access Journals (Sweden)

    José Mejía Haro

    2012-02-01

    Full Text Available The variation in voluntary forage intake is undoubtedly the major dietary factor determining level and efficiency of ruminant production. This variation is bigger and least predictable for grazing ruminants. Range ruminant productivity and efficiency is relatively low due, partly, to intake limitations; productivity could probably be increased most by increasing intake. Distension of the reticulo-rumen wall is the primary intake regulation mechanism of low-quality roughages in range ruminants, digestibility and rate of ingest passage also affect voluntary intake. Body size and metabolic bodysize as well affect intake of grazing animals. Kind and amount of supplementation, forage availability, and grazing intensity have been related to voluntary forage intake. La variación en el consumo voluntario de forraje es indudablemente el principal factor dietario que determina el nivel y eficiencia de producción en un rumiante. Esta variación es mayor y muy difícil de predecir bajo condiciones de pastoreo. La productividad y eficiencia de rumiantes en pastoreo es relativamente baja debido, en parte, a las limitaciones en el consumo; la productividad probablemente se podrá incrementar si se incrementa el consumo. La distensión de la pared del rumenretículo es el principal mecanismo de regulación del consumo de forrajes de baja calidad en rumiantes en pastoreo, aunque la digestibilidad y la tasa de pasaje también afectan el consumo voluntario. Igualmente, el consumo se ve afectado por el tamaño corporal y peso metabólico del animal, por la cantidad y tipo de suplemento ofrecido, por la disponibilidad de forraje y por la intensidad del pastoreo.

  16. Influence of plasma density and plasma sheath dynamics on the ion implantation by plasma immersion technique

    OpenAIRE

    Ensinger, Wolfgang

    1996-01-01

    Influence of plasma density and plasma sheath dynamics on the ion implantation by plasma immersion technique / B. Rauschenbach ... - In: Nuclear instruments and methods in physics research. B. 113. 1996. S. 266-269

  17. Instabilities in inhomogeneous plasma

    International Nuclear Information System (INIS)

    Mikhailovsky, A.B.

    1983-01-01

    The plasma inhomogeneity across the magnetic field causes a wide class of instabilities which are called instabilities of an inhomogeneous plasma or gradient instabilities. The instabilities that can be studied in the approximation of a magnetic field with parallel straight field lines are treated first, followed by a discussion of the influence of shear on these instabilities. The instabilities of a weakly inhomogeneous plasma with the Maxwellian velocity distribution of particles caused by the density and temperature gradients are often called drift instabilities, and the corresponding types of perturbations are the drift waves. An elementary theory of drift instabilities is presented, based on the simplest equations of motion of particles in the field of low-frequency and long-wavelength perturbations. Following that is a more complete theory of inhomogeneous collisionless plasma instabilities which uses the permittivity tensor and, in the case of electrostatic perturbations, the scalar of permittivity. The results are used to study the instabilities of a strongly inhomogeneous plasma. The instabilities of a plasma in crossed fields are discussed and the electromagnetic instabilities of plasma with finite and high pressure are described. (Auth.)

  18. High energy plasma accelerators

    International Nuclear Information System (INIS)

    Tajima, T.

    1985-05-01

    Colinear intense laser beams ω 0 , kappa 0 and ω 1 , kappa 1 shone on a plasma with frequency separation equal to the electron plasma frequency ω/sub pe/ are capable of creating a coherent large longitudinal electric field E/sub L/ = mc ω/sub pe//e of the order of 1GeV/cm for a plasma density of 10 18 cm -3 through the laser beat excitation of plasma oscillations. Accompanying favorable and deleterious physical effects using this process for a high energy beat-wave accelerator are discussed: the longitudinal dephasing, pump depletion, the transverse laser diffraction, plasma turbulence effects, self-steepening, self-focusing, etc. The basic equation, the driven nonlinear Schroedinger equation, is derived to describe this system. Advanced accelerator concepts to overcome some of these problems are proposed, including the plasma fiber accelerator of various variations. An advanced laser architecture suitable for the beat-wave accelerator is suggested. Accelerator physics issues such as the luminosity are discussed. Applications of the present process to the current drive in a plasma and to the excitation of collective oscillations within nuclei are also discussed

  19. Plasma Science Committee (PLSC)

    International Nuclear Information System (INIS)

    1990-01-01

    The Plasma Science Committee (PLSC) is a standing committee under the auspices of the Board on Physics and Astronomy, Commission on Physical Sciences, Mathematics, and Applications of the National Academy of Sciences--National Research Council. Plasma sciences represent a broad and diverse field. The PLSC has accepted the responsibility of monitoring the continuing development and assessing the general health of the field as whole. Although select advisory bodies have been created to address specific issues that affect plasma science, such as the Fusion Policy Advisory Committee (FPAC), the PLSC provides a focus for the plasma science community that is unique and essential. The membership of the PLSC is drawn from research laboratories in universities, industry, and government. Areas of expertise on the committee include accelerators and beams, space physics, astrophysics, computational physics and applied mathematics, fusion plasmas, fundamental experiments and theory, radiation sources, low temperature plasmas, and plasma-surface interactions. The PLSC is well prepared to respond to requests for studies on specific issues. This report discusses ion of the PLSC work

  20. Electromagnetic separator of plasma

    International Nuclear Information System (INIS)

    Gasilin, V.V.; Nezovibatko, Yu.N.; Poklepach, G.S.; Shvets, O.M.; Taran, V.S.; Tereshin, V.I.

    2005-01-01

    The progress in the widespread utilization of the PVD methods is determined in many respects by the plasma quality and, therefore, the necessity of an application of plasma separators, in particular magnetic separators. One needs to note that traditional magnetic separators have a number of problems their using, namely their unwieldiness, the presence of the isolated cameras and so on. We have proposed, manufactured and investigated the simple separator of plasma that doesn't require using additional cameras. As a source of metallic plasma the standard cathode vaporizer in the installation 'BULAT 6' was in use. Plasma stream from the cathode flowed through the not protected by isolation spiral solenoid. The solenoid input (from the cathode side) was under floating potential. The solenoid output was connected to the autonomous power supply system. The solenoid was prepared with stride winding and 90 degree turn. The solenoid current was 20-90 A and the solenoid voltage with respect to the vessel (earth) was +15 V. In this case drifting charged particles could freely fly out from the interior solenoid region to its boundary. The glow of the turned flow of plasma was observed during the supplying of the cathode and the solenoid. Plasma flow was separated from the coils and extended along the axis of solenoid. One can assume that this device ensures radial electric with respect to the bulk of plasma (the diameter of the bulk of plasma is comparable with the cathode diameter), the toroidal magnetic field, produced by solenoid, was of an order of 20 Oe. Magnetic field strength was sufficient for the magnetization of electrons, but it was rather small for magnetizing the ions and charged micro-droplets. The experiments carried out with aluminum cathode on the deposition of coatings at the stainless steel substrate have shown the high effectiveness of this separator operation. Coatings without droplets were obtained also on the glass substrate with HF- displacement

  1. The expanding plasma jet

    International Nuclear Information System (INIS)

    Sanden, M.C.M. van den.

    1991-01-01

    This thesis concerns the fundamental aspects of an argon plasma expanding from a cascaded arc. This type of plasma is not only used for fundamental research but also for technologically orientated research on plasma deposition and plasma sources. The important characteristics of the plasma are a strong supersonic expansion in which the neutral particle and ion densities decrease three orders of magnitude, followed by a stationary shock front. After the shock front the plasma expands further subsonically. A part of this thesis is devoted to the discussion of a newly constructed combined Thomson-Rayleigh scattering set up. With this set up the electron density, the electron temperature and the neutral particle density are measured locally in the plasma for different conditions. In the analysis of the measured spectra weak coherent effects and the measured apparatus profile are included. The inaccuracies are small, ranging from 1 to 4 percent for the electron density and 2 to 6 percent for the electron temperature, depending on the plasma conditions. The inaccuracy of the neutral particle density determination is larger and ranges from 10 to 50 percent. The detection limits for the electron and neutral particle density are 7.10 17 m -3 and 1.10 20 m -3 respectively. A side path in this thesis is the derivation of the Saha equation for a two-temperature plasma. The reason for this derivation was the dispute in the literature about the correct form of this equation. In this thesis it is shown, from the correct extension of the second law of thermodynamics and from the non-equilibrium formalism of Zubarev, That in the limit of m e /m h ->0 the generalized Saha equation depends on the electron temperature only. (author). 221 refs.; 54 figs.; 13 tabs

  2. Intoxicación ocupacional por mercurio

    Directory of Open Access Journals (Sweden)

    Augusto V Ramírez

    2008-03-01

    Full Text Available El mercurio, metal pesado ampliamente utilizado por el hombre, es muy tóxico; produce daño al sistema nervioso central, perturbaciones del comportamiento y lesiones renales. Se acumula en todos los seres vivos y no es esencial para ningún proceso biológico. La toxicidad del mercurio está directamente relacionada con su estado químico. El metilmercurio es la forma más dañina, con efectos neurotóxicos en adultos y en fetos de madres expuestas. El mercurio metálico no es menos tóxico. Las sales de mercurio inorgánico afectan directamente al riñón. Clínicamente, en la exposición ocupacional a mercurio se encuentra la triada clásica: temblor, alteración de la personalidad y estomatitis. En los últimos años se ha demostrado también alteración en la visión cromática. La exposición aguda se evalúa midiendo el mercurio en la sangre, mientras que la exposición crónica y ocupacional se determina mejor dosándolo en orina homogenizada de 24 horas. Los quelantes del metal -BAL, sus derivados o la D-penicilamina- son usados para tratar la intoxicación aguda o crónica.

  3. Histeria ainda hoje, por quê?

    Directory of Open Access Journals (Sweden)

    Dayse Santos Costa

    2016-04-01

    Full Text Available Resumo Estudo teórico que teve o propósito de discutir a histeria na contemporaneidade, considerando as mudanças culturais que podem ter acorrido desde a fundação da psicanálise até hoje. A discussão teve como cerne os apontamentos de Charles Melman, posto que seja um psicanalista que vem pensando a posição do sujeito nas condições da cultura ocidental atual. Foram destacados aspectos que nos conduziram a elaborar um pensamento em torno de como a neurose histérica aparece no contexto contemporâneo. Partimos do princípio de que sofremos uma mutação cultural, na qual passamos de uma cultura propensa à neurose para uma propensa à perversão. Tal concepção determina que lidamos com sujeitos que funcionam sob a ordem de uma nova economia psíquica e que em decorrência assistimos a expressão de uma histeria coletiva que, por sua vez, seria espaço de reivindicação dos sujeitos, a fim de requisitar um paradeiro e reinventar um pai que já esteja destituído.

  4. Identidad e interculturalidad: un horizonte por visitar

    Directory of Open Access Journals (Sweden)

    Marian Pérez Bernal

    2016-01-01

    Full Text Available En el presente trabajo mantenemos que el concepto de identidad defendido por Amin Maalouf puede ser una interesante vía para conseguir una aproximación entre las distintas culturas capaz de conducirnos a un diálogo fructífero que nos permitan gestionar la multiculturalidad actual. Defendemos que las culturas sean vistas como escenas de debate y contestación en constante proceso de construcción y reconstrucción y en las que siempre primen unos valores que nos conciernen a todos y que han de ser irrenunciables.In this paper, it is stated that the concept of identity defended by Amin Maalouf could be an interesting way to achieve a rapprochement amongst different cultures. This could lead to a fruitful dialog allowing to manage today’s multiculturalism. It is also defended that cultures should be considered as instruments of debate and reply on a continuous process of construction and reconstruction. However, cultures should not prevail over a series of values that concern to all of us and that should be inalienable.

  5. Libertad, igualdad, sostenibilidad. Por un ecofeminismo ilustrado

    Directory of Open Access Journals (Sweden)

    Puleo, Alicia H.

    2008-06-01

    Full Text Available This article presents the proposal of an enlightened Ecofeminism and defines it as an ethic-political thinking about human relations to Nature. It aims at ecojustice and sustainability, which are characterized through the criticism of prejudice, through the principles of equality and autonomy, and through the nominalist conceptualization of gender, intercultural dialogue and the sensible acceptance of science and technique. The enlightened Ecofeminism universalizes virtues such as caring for the human and non-human Nature, and defends a compassionate moral towards the radical finitude of the world.

    En este artículo se presenta la propuesta de un ecofeminismo ilustrado entendido como reflexión ético-política sobre las relaciones de los humanos con la Naturaleza. Orientado a la ecojusticia y la sostenibilidad, el ecofeminismo ilustrado se caracterizaría por la crítica al prejuicio, la defensa de los principios de igualdad y autonomía, la conceptualización nominalista del género, el diálogo intercultural, la aceptación prudente de la ciencia y la técnica, la universalización de las virtudes del cuidado aplicadas a los humanos y al resto de la Naturaleza, y una moral de la compasión frente a la radical finitud del mundo.

  6. Estudio electrofisiologico en la neuropatia por Vincristina

    Directory of Open Access Journals (Sweden)

    Olga P. Sanz

    1975-12-01

    Full Text Available Diez pacientes afectados por diversas patologías que requerían tratamiento crónico con Vincristina, fueron sometidos a estudios electrofisiológicos en los que se valoró: el número de unidades motoras (UM funcionantes en los músculos de la eminencia tenar, los valores de los incrementos medios de UM, velocidad de conducción motora y su latencia residual en el nervio mediano, la velocidad de conducción sensitiva del mismo nervio y el estado de la transmisión neuromuscular. Los valores obtenidos fueron comparados con grupos controles. Los resultados mostraron disminución del número de UM; las UM remanentes presentaron amplitud reducida junto a otras cuyo tamaño no superaba el del grupo control, hecho que sugiere la incapacidad de lograr una reinervación adecuada. Las velocidades de conducción motora y sensitiva mostraron valores diminuídos, con mayor compromiso en los segmentos distales. Junto a estos datos se halló respuesta miasteniforme al estímulo repetitivo. Todos estos resultados permiten postular la existencia de un compromiso de la unidad motora, abarcando todos sus segmentos, en pacientes intoxicados con Vincristina.

  7. Transport barriers in plasmas

    International Nuclear Information System (INIS)

    Caldas, I L; Szezech, J D Jr; Kroetz, T; Marcus, F A; Roberto, M; Viana, R L; Lopes, S R

    2012-01-01

    We discuss the creation of transport barriers in magnetically confined plasmas with non monotonic equilibrium radial profiles. These barriers reduce the transport in the shearless region (i.e., where the twist condition does not hold). For the chaotic motion of particles in an equilibrium electric field with a nonmonotonic radial profile, perturbed by electrostatic waves, we show that a nontwist transport barrier can be created in the plasma by modifying the electric field radial profile. We also show non twist barriers in chaotic magnetic field line transport in the plasma near to the tokamak wall with resonant modes due to electric currents in external coils.

  8. Radioimmunoassay of plasma progesterone

    Energy Technology Data Exchange (ETDEWEB)

    Langer, L; Veleminsky, J [Institute of Clinical Endocrinology, Lubochna (Czechoslovakia); Hampl, R; Starka, L [Vyzkumny Ustav Endokrinologicky, Prague (Czechoslovakia); Holan, J [Comenius Univ., School of Medicine, Martin (Czechoslovakia). Dept. of Physics and Nuclear Medicine

    1978-06-30

    A simple modification of plasma progesterone radioimmunoassay is described. 11..cap alpha..-Hydroxyprogesterone hemisuccinate - BSA conjugate was used as an immunogen. (1,2,6,7-H-3) Progesterone specific radioactivity 82 Ci.mmol/sup -1/ was purchased from Radiochemical Centre Amersham (England). The method has been applied for the analysis of more than 2000 plasma samples. The typical fluctuation of progesterone in plasma during the menstrual cycle, using data obtained with this method is illustrated. The reliability criteria of the method are given.

  9. Unexpected high plasma cobalamin

    DEFF Research Database (Denmark)

    Arendt, Johan F B; Nexo, Ebba

    2013-01-01

    It is well-established that more than 8% of patients examined for vitamin B12 deficiency unexpectedly have increased plasma levels of the vitamin, but so far there are no guidelines for the clinical interpretation of such findings. In this review, we summarise known associations between high plasma...... cobalamin binding proteins, transcobalamin and haptocorrin. Based on current knowledge, we suggest a strategy for the clinical interpretation of unexpected high plasma cobalamin. Since a number of the associated diseases are critical and life-threatening, the strategy promotes the concept of 'think...

  10. Ambipolar diffusion in plasma

    International Nuclear Information System (INIS)

    Silva, T.L. da.

    1987-01-01

    Is this thesis, a numerical method for the solution of the linear diffusion equation for a plasma containing two types of ions, with the possibility of charge exchange, has been developed. It has been shown that the decay time of the electron and ion densities is much smaller than that in a plasma containing only a single type of ion. A non-linear diffusion equation, which includes the effects of an external electric field varying linearly in time, to describe a slightly ionized plasma has also been developed. It has been verified that the decay of the electron density in the presence of such an electric field is very slow. (author)

  11. Nonequilibrium Phenomena in Plasmas

    CERN Document Server

    Sharma, A Surjalal

    2005-01-01

    The complexity of plasmas arises mainly from their inherent nonlinearity and far from equilibrium nature. The nonequilibrium behavior of plasmas is evident in the natural settings, for example, in the Earth's magnetosphere. Similarly, laboratory plasmas such as fusion bottles also have their fair share of complex behavior. Nonequilibrium phenomena are intimately connected with statistical dynamics and form one of the growing research areas in modern nonlinear physics. These studies encompass the ideas of self-organization, phase transition, critical phenomena, self-organized criticality and turbulence. This book presents studies of complexity in the context of nonequilibrium phenomena using theory, modeling, simulations, and experiments, both in the laboratory and in nature.

  12. Computing in plasma physics

    International Nuclear Information System (INIS)

    Nuehrenberg, J.

    1986-01-01

    These proceedings contain the articles presented at the named conference. These concern numerical methods for astrophysical plasmas, the numerical simulation of reversed-field pinch dynamics, methods for numerical simulation of ideal MHD stability of axisymmetric plasmas, calculations of the resistive internal m=1 mode in tokamaks, parallel computing and multitasking, particle simulation methods in plasma physics, 2-D Lagrangian studies of symmetry and stability of laser fusion targets, computing of rf heating and current drive in tokamaks, three-dimensional free boundary calculations using a spectral Green's function method, as well as the calculation of three-dimensional MHD equilibria with islands and stochastic regions. See hints under the relevant topics. (HSI)

  13. Plasma control and utilization

    International Nuclear Information System (INIS)

    Ensley, D.L.

    1976-01-01

    A plasma is confined and heated by a microwave field resonant in a cavity excited in a combination of the TE and TM modes while responding to the resonant frequency of the cavity as the plasma dimensions change to maintain operation at resonance. The microwave field is elliptically or circularly polarized as to prevent the electromagnetic confining field from going to zero. A high Q chamber having superconductive walls is employed to minimize wall losses while providing for extraction of thermonuclear energy produced by fusion of nuclei in the plasma. 24 claims, 15 figures

  14. Radiofrequency power in plasmas

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-12-31

    This document includes the various communications that were presented at the 11th topical conference on radio frequency power in plasmas which took place in Palm Springs in May 1995. It includes current diffusion studies to assess the non-inductive current deposition profiles, experiments for plasma to reach quickly an equilibrium state, and modelling of electrons in plasma. Some comparison studies also reveal the efficiency of the Quasi-Optical Grill antenna for reactor applications. Finally, a scenario for efficient mode conversion heating in the ion cyclotron range of frequency is presented. Separate abstracts were prepared for the 6 papers in this volume. (TEC).

  15. Plasma processing: Technologies and applications

    International Nuclear Information System (INIS)

    Naddaf, M.; Saloum, S.

    2005-01-01

    This study aims to present the fundamentals of physics of plasmas, methods of generation, diagnostics, and applications for processing of materials. The first chapter defines plasma in general as well as its main parameters, the most important differential equations in plasma physics, and classifies the types of plasmas. the various methods and techniques to create and sustain plasma are presented in the second chapter. Chapter 3 focuses on plasma diagnostic methods and tools. While chapter 4 deals with applications of plasma processing such as; surface modification of materials, plasma ashing and etching, plasma cutting, and the environmental applications of plasma. Plasma polymerization and its various applications have been presented in more details in the last chapter. (Author)

  16. Itinerarios Didácticos por la isla de Lanzarote

    OpenAIRE

    Becerra-Ramírez, Rafael; González Cárdenas, Elena; Gosálvez, Rafael U.; Escobar Lahoz, Estela; Dóniz-Páez, Javier

    2013-01-01

    Con la confección de esta guía de itinerarios didácticos por la isla de Lanzarote pretendemos contribuir a un mayor conocimiento de las características geográficas de este espacio dominado por las formas volcánicas que caracterizan un paisaje modificado por la mano del hombre que convive con los volcanes y los usa, tradicionalmente como soporte de sus cultivos, y modernamente como base de la industria turística. Los itinerarios didácticos por la isla de Lanzarote son la adaptación de los t...

  17. Unmatter Plasma revisited

    Science.gov (United States)

    Smarandache, Florentin

    2017-10-01

    Unmmatter Plasma is a novel form of plasma, exclusively made of matter and its antimatter counterpart. The electron-positron beam plasma was generated in the laboratory in the beginning of 2015. This experimental fact shows that unmatter, a new form of matter that is formed by matter and antimatter bind together (mathematically predicted since 2004) really exists. That is the electron-positron plasma experiment of 2015 is the experimentum crucis verifying the mathematically predicted unmatter. Unmatter is formed by combinations of matter and antimatter that bind together, or by long-range mixture of matter and antimatter forming a weakly-coupled phase. Binding and bound state means that the interaction is sufficiently strong to tie together the particles of a system, therefore hindering them from becoming free. For example, a usual liquid is a bound state of molecules, while a gas is an un-bounded where the molecules can move freely in successive collisions.

  18. Plasma concentrations of misonidazole

    Energy Technology Data Exchange (ETDEWEB)

    Notter, G; Rylander, U; Turesson, I

    1980-10-01

    The plasma concentrations of misonidazole doses between 0.6 and 2.0 g/m/sup 2/ were analyzed in respect to the variation within the same patient and between different patients. Peak plasma levels were observed after 2 hours. The mean plasma levels of misonidazole only at 3 hours were 23.8, 47.0 and 76.5 ..mu..g/ml after misonidazole doses of 0.6, 1.2 g/m/sup 2/, respectively. The half-life of misonidazole only was found to be 8.2 hours for women and 10.5 for men. Good linearity between plasma levels and drug doses was observed after administration of different single doses to the same patient within the dose range 0.6 to 2.0 g/m/sup 2/.

  19. Plasma-surface interaction

    International Nuclear Information System (INIS)

    Kurnaev, V.A.

    1996-01-01

    The latest experimental results characterizing plasma interaction with walls in thermonuclear facilities are presented. The main attention is paid to the mode of plasma ejection from the tokamak divertor receiving elements to study the properties of the so-called gas divertor. A sharp reduction of load on the receiving plates is provided in the mode at the expense of over-radiation of a substantial share of power in a layer of peripheral removed plasma. However, the sharp reduction of load on the current-receiving plates is accompanied by an increase of the main plasma charge up to an unacceptably high level. An alternative variant of solving the problem of heat and impurity removal in the form of a concept of capillary lithium divertor is described. Besides, the latest results of experiments in simulator devices are presented. 46 refs., 15 figs

  20. Plasma formation in TBR

    International Nuclear Information System (INIS)

    Del Bosco, E.

    1981-01-01

    In this work are presented and discussed results of the formation and equilibrium of the plasma current in TBR, a small tokamak, designed and contructed at the Instituto de Fisica of Universidade de Sao Paulo. The measured breakdown curves for H 2 , A and He are compared with the predictions of a simple model with reasonable agreement. The influence of stray magnetic fields in the plasma formation is investigated and conditions are chosen to facilitate the breakdown. The time profile of loop voltage and plasma current for shots with plasma equilibrium are shown. A comparison is made between experimental results and analytical-numerical model for tokamaks discharges with ohmic heating. Reasonable agreement is obtained when Z, effective atomic number, is assumed as a parameter. (Author) [pt

  1. Vol. 6: Plasma Physics

    International Nuclear Information System (INIS)

    Sitenko, A.

    1993-01-01

    Problems of modern physics and the situation with physical research in Ukraine are considered. Programme of the conference includes scientific and general problems. Its proceeding are published in 6 volumes. The papers presented in this volume refer to plasma physics

  2. Ferroelectric Plasma Thruster

    National Research Council Canada - National Science Library

    Kovaleski, Scott D; Kemp, Mark A

    2008-01-01

    .... When radiofrequency high voltage is applied between the electrodes, through the thickness of the crystal, a combination of triple point and piezoelectric effects produce dense plasma on the crystal surface...

  3. Fizeau plasma interferometer

    International Nuclear Information System (INIS)

    Frank, A.M.

    1980-01-01

    This paper describes a technique by which the sensitivity of plasma interferometers can be increased. Stabilization and fractional fringe measurement techniques have improved to the point where additional optical sensitivity could be useful

  4. Plasma relativistic microwave electronics

    International Nuclear Information System (INIS)

    Kuzelev, M.V.; Loza, O.T.; Rukhadze, A.A.; Strelkov, P.S.; Shkvarunets, A.G.

    2001-01-01

    One formulated the principles of plasma relativistic microwave electronics based on the induced Cherenkov radiation of electromagnetic waves at interaction of a relativistic electron beam with plasma. One developed the theory of plasma relativistic generators and accelerators of microwave radiation, designed and studied the prototypes of such devices. One studied theoretically the mechanisms of radiation, calculated the efficiencies and the frequency spectra of plasma relativistic microwave generators and accelerators. The theory findings are proved by the experiment: intensity of the designed sources of microwave radiation is equal to 500 μW, the frequency of microwave radiation is increased by 7 times (from 4 up to 28 GHz), the width of radiation frequency band may vary from several up to 100%. The designed sources of microwave radiation are no else compared in the electronics [ru

  5. Plasma turbulence in tokamaks

    Energy Technology Data Exchange (ETDEWEB)

    Caldas, Ibere L.; Heller, M.V.A.P.; Brasilio, Z.A. [Sao Paulo Univ., SP, RJ (Brazil). Inst. de Fisica

    1997-12-31

    Full text. In this work we summarize the results from experiments on electrostatic and magnetic fluctuations in tokamak plasmas. Spectral analyses show that these fluctuations are turbulent, having a broad spectrum of wavectors and a broad spectrum of frequencies at each wavector. The electrostatic turbulence induces unexpected anomalous particle transport that deteriorates the plasma confinement. The relationship of these fluctuations to the current state of plasma theory is still unclear. Furthermore, we describe also attempts to control this plasma turbulence with external magnetic perturbations that create chaotic magnetic configurations. Accordingly, the magnetic field lines may become chaotic and then induce a Lagrangian diffusion. Moreover, to discuss nonlinear coupling and intermittency, we present results obtained by using numerical techniques as bi spectral and wavelet analyses. (author)

  6. Micro Plasma Spectrometer

    Data.gov (United States)

    National Aeronautics and Space Administration — The purpose of this IRAD project is to develop a preliminary design elements of miniature electron and ion plasma spectrometers and supporting electronics, focusing...

  7. Gingival plasma cell granuloma

    Directory of Open Access Journals (Sweden)

    Amitkumar B Pandav

    2012-01-01

    Full Text Available Plasma cell granuloma, also known as inflammatory pseudotumor is a tumor-like lesion that manifests primarily in the lungs. But it may occur in various other anatomic locations like orbit, head and neck, liver and rarely in the oral cavity. We here report an exceedingly rare case of gingival plasma cell granuloma in a 58 year old woman who presented with upper gingival polypoidal growth. The histopathological examination revealed a mass composed of proliferation of benign spindle mesenchymal cells in a loose myxoid and fibrocollagenous stroma along with dense infiltrate of chronic inflammatory cells predominantly containing plasma cells. Immunohistochemistry for kappa and lambda light chains showed a polyclonal staining pattern confirming a diagnosis of plasma cell granuloma.

  8. Computational plasma physics

    International Nuclear Information System (INIS)

    Killeen, J.

    1975-08-01

    The behavior of a plasma confined by a magnetic field is simulated by a variety of numerical models. Some models used on a short time scale give detailed knowledge of the plasma on a microscopic scale, while other models used on much longer time scales compute macroscopic properties of the plasma dynamics. In the last two years there has been a substantial increase in the numerical modelling of fusion devices. The status of MHD, transport, equilibrium, stability, Vlasov, Fokker-Planck, and Hybrid codes is reviewed. These codes have already been essential in the design and understanding of low and high beta toroidal experiments and mirror systems. The design of the next generation of fusion experiments and fusion test reactors will require continual development of these numerical models in order to include the best available plasma physics description and also to increase the geometric complexity of the model. (auth)

  9. Plasma sprayed thermoregulating coatings

    International Nuclear Information System (INIS)

    Kudinov, V.V.; Puzanov, A.A.; Zambrzhitskij, A.P.; Soboleva, V.V.

    1979-01-01

    Shown is the possibility of plasma spraying application for thermoregulating coating formation. Given are test results of service properties of BeO, Al 2 O 2 plasma coatings on the substrates of the MA2-1 magnesium alloy. Described is a device for studying durability of coating optical parameters under ultraviolet irradiation in deep vacuum. Dynamics of absorption coefficient, growth caused by an increase in absorption centers amount under such irradiation is investigated

  10. Carbon plasma gun

    International Nuclear Information System (INIS)

    Mendel, C.W. Jr.; Zagar, D.M.; Mills, G.S.; Humphries, S. Jr.; Goldstein, S.A.

    1980-01-01

    A family of plasma guns supplying highly ionized carbon plasma is described. The guns are simple and inexpensive to construct and are pulsed by small capacitor banks of a few hundred joules. The output consists of 10 17 --10 18 multiply ionized carbon ions traveling at about 10 7 cm/s. Neutral output is very low and arrives well after the ionized carbon. The guns and pulsers are very reliable

  11. Plasma emission mechanisms

    International Nuclear Information System (INIS)

    Melrose, D.B.

    1985-01-01

    Only three emission processes are thought to play a role in solar radio emission: plasma emission, gyromagnetic emission and bremsstrahlung. In this chapter plasma emission is discussed and the processes involved in its production are treated, namely, the generation of Langmuir turbulence, the partial conversion into fundamental transverse radiation, production of secondary Langmuir waves and the generation of second-harmonic transverse radiation. (U.K.)

  12. Heating in toroidal plasmas

    International Nuclear Information System (INIS)

    Canobbio, E.

    1981-01-01

    This paper reports on the 2nd Joint Grenoble-Varenna International Symposium on Heating in Toroidal Plasmas, held at Como, Italy, from the 3-12 September 1980. Important problems in relation to the different existing processes of heating. The plasma were identified and discussed. Among others, the main processes discussed were: a) neutral beam heating, b) ion-(electron)-cyclotron resonance heating, c) hybrid resonance and low frequency heating

  13. Dynamics of magnetospheric plasmas

    International Nuclear Information System (INIS)

    Horwitz, J.L.

    1985-01-01

    The dynamical behavior of the magnetospheric plasmas which control the electrostatic charging of spacecraft is the result of the complex interaction of a variety of production, loss, transport, and energization mechanisms in the magnetosphere. This paper is intended to provide the spacecraft engineer with a foundation in the basic morphology and controlling processes pertaining to magnetospheric plasma dynamics in the inner magnetosphere, including the synchronous orbit region. 32 references

  14. Radio frequency plasma excitation

    International Nuclear Information System (INIS)

    Burden, M.St.J.; Cross, K.B.

    1979-01-01

    An investigation into the use of rf sputtering for ion cleaning of insulating substrates before ion plating is reported. Initial experiments consisted of sputtering metals with rf power followed by the deposition of copper onto glass slides using rf plasma excitation and biasing supply. It was found that good quality films were obtained by rf ion plating onto plastics with excellent adhesion over a wide operating pressure range. A block schematic of the rf plasma excitation system is shown. (UK)

  15. Multicusp plasma containment apparatus

    International Nuclear Information System (INIS)

    Limpaecher, R.

    1980-01-01

    It has been discovered that plasma containment by a chamber having multi-pole magnetic cusp reflecting walls in combination with electronic injection for electrostatic containment provides the means for generating magnetic field free quiescent plasmas for practical application in ion-pumps, electronic switches, and the like. 1250 ''alnico v'' magnets 1/2 '' X 1/2 '' X 1 1/2 '' provide containment in one embodiment. Electromagnets embodying toroidal funneling extend the principle to fusion apparatus

  16. Numerical simulation of plasmas

    International Nuclear Information System (INIS)

    Dnestrovskii, Y.N.; Kostomarov, D.P.

    1986-01-01

    This book contains a modern consistent and systematic presentation of numerical computer simulation of plasmas in controlled thermonuclear fusion. The authors focus on the Soviet research in mathematical modelling of Tokamak plasmas, and present kinetic hydrodynamic and transport models with special emphasis on the more recent hybrid models. Compared with the first edition (in Russian) this book has been greatly revised and updated. (orig./WL)

  17. Oscillations in quasineutral plasmas

    International Nuclear Information System (INIS)

    Grenier, E.

    1996-01-01

    The purpose of this article is to describe the limit, as the vacuum electric permittivity goes to zero, of a plasma physics system, deduced from the Vlasov-Poisson system for special initial data (distribution functions which are analytic in the space variable, with compact support in velocity), a limit also called open-quotes quasineutral regimeclose quotes of the plasma, and the related oscillations of the electric field, with high frequency in time. 20 refs

  18. Measuring the Plasma Density of a Ferroelectric Plasma Source in an Expanding Plasma

    International Nuclear Information System (INIS)

    Dunaevsky, A.; Fisch, N.J.

    2003-01-01

    The initial density and electron temperature at the surface of a ferroelectric plasma source were deduced from floating probe measurements in an expanding plasma. The method exploits negative charging of the floating probe capacitance by fast flows before the expanding plasma reaches the probe. The temporal profiles of the plasma density can be obtained from the voltage traces of the discharge of the charged probe capacitance by the ion current from the expanding plasma. The temporal profiles of the plasma density, at two different distances from the surface of the ferroelectric plasma source, could be further fitted by using the density profiles for the expanding plasma. This gives the initial values of the plasma density and electron temperature at the surface. The method could be useful for any pulsed discharge, which is accompanied by considerable electromagnetic noise, if the initial plasma parameters might be deduced from measurements in expanding plasma

  19. From particles to plasmas

    International Nuclear Information System (INIS)

    Van Dam, J.W.

    1989-01-01

    The title of this book, From Particles to Plasmas, has more than one meaning. First, it reflects how the scientific career of Marshall Rosenbluth has evolved, beginning in the field of elementary particle physics and extending into his major area of plasma physics. Secondly, it is meant to suggest the wide spectrum of subject matters addressed in the individual lectures, ranging from numerical simulation and space physics and accelerators to various subfields in the physics of plasmas. In the third place, the title is a reference to the way in which the theoretical description of plasmas is often constructed, namely starting from the motion of single particles and then incorporating collective effects. Most of the contributions in this book do concern various aspects of fusion plasma physics, which is the field in which most of Marshall Rosenbluth's scientific contributions have been and are being made. In this field his eminence and authority are indicated by the sobriquet pope of plasma physics that is often applied to him

  20. Plasma control device

    International Nuclear Information System (INIS)

    Matsutomi, Akiyoshi.

    1995-01-01

    Plasma position and shape estimation values are outputted based on measured values of coil current. When the measured values of the position and the shape are judged to be abnormal, position and shape estimation values estimated by a plasma position and shape estimation means are outputted as position and shape feed back values to a plasma position and shape control means instead of the position and shape measured values. Since only a portion of the abnormal position and shape measured values may also be replaced with the position and shape estimation values, errors in the plasma position and shape feed back values can be reduced as a whole. In addition, even if the position and shape measured values are abnormal or if they can not be measured, plasma control can be continued by alternative position and shape estimation values, thereby enabling to avoid interruption of plasma control. Since the position and shape estimation values are obtained not only with the measured values of coil current but also with the position and shape estimation values, the accuracy is improved. Further, noises superposed on the position and shape measured values are filtered, and the device is stabilized compared with a prior art device. (N.H.)

  1. Plasma position control device

    International Nuclear Information System (INIS)

    Takase, Haruhiko.

    1987-01-01

    Purpose: To conduct position control stably to various plasmas and reduce the burden on the control coil power source. Constitution: Among the proportional, integration and differentiation controls, a proportional-differentiation control section and an integration control section are connected in parallel. Then, a signal switching circuit is disposed to the control signal input section for the proportional-differentiation control section such that either a present position of plasmas or deviation between the present plasma position and an aimed value can be selected as a control signal depending on the control procedures or the state of the plasmas. For instance, if a rapid response is required for the control, the deviation between the present plasma position and the aimed value is selected as the input signal to conduct proportional, integration and differentiation controls. While on the other hand, if it is intended to reduce the burden on the control coil power source, it is adapted such that the control signal inputted to the proportional-differentiation control section itself can select the present plasma position. (Yoshihara, H.)

  2. Thermal plasmas: fundamental aspects

    International Nuclear Information System (INIS)

    Fauchais, P.

    2005-01-01

    This article treats of thermal plasmas, i.e. mainly produced by electric arcs and RF discharges. Their main characteristic is that they are generated at a pressure close to the atmospheric pressure (between 10 4 and 10 6 Pa) and refer to the classical kinetics of the Boltzmann equation. Because of the pressure, the collisions between particles are numerous and ionization is mainly due to a thermal effect. They correspond to electron densities between 10 20 and 10 24 m -3 and temperatures between 6000 and 25000 K. In these plasmas, the electric fields and the average free trajectories are too weak to generate a ionization state by direct inelastic collision. Ionization is thus essentially a thermal phenomenon due to elastic collisions. This article presents: 1 - the particles present in a plasma: definition, energy states; 2 - characteristic data: collisions, average free path and collision cross-section, distribution function, ionization types, charged particles mobility inside an electric field, scattering, Debye length; 3 - plasmas at the thermodynamical equilibrium: conditions of equilibrium, calculation of composition, thermodynamic properties, transport properties, radiation; 4 - thermal plasmas away from equilibrium: conditions of non-equilibrium, calculation of plasma composition, calculation of transport properties, quenching phenomenon. (J.S.)

  3. Online plasma calculator

    Science.gov (United States)

    Wisniewski, H.; Gourdain, P.-A.

    2017-10-01

    APOLLO is an online, Linux based plasma calculator. Users can input variables that correspond to their specific plasma, such as ion and electron densities, temperatures, and external magnetic fields. The system is based on a webserver where a FastCGI protocol computes key plasma parameters including frequencies, lengths, velocities, and dimensionless numbers. FastCGI was chosen to overcome security problems caused by JAVA-based plugins. The FastCGI also speeds up calculations over PHP based systems. APOLLO is built upon the WT library, which turns any web browser into a versatile, fast graphic user interface. All values with units are expressed in SI units except temperature, which is in electron-volts. SI units were chosen over cgs units because of the gradual shift to using SI units within the plasma community. APOLLO is intended to be a fast calculator that also provides the user with the proper equations used to calculate the plasma parameters. This system is intended to be used by undergraduates taking plasma courses as well as graduate students and researchers who need a quick reference calculation.

  4. Fueling by coaxial plasma guns

    International Nuclear Information System (INIS)

    Marshall, J.

    1977-01-01

    A review of the operational characteristics of ''snowplow'' and ''deflagration'' coaxial plasma guns is given. The injection of these plasmas into containment fields is discussed. The effect of a background plasma on low-beta injection is mentioned. The use of high-beta injection for reactor plasmas is described

  5. Numerical simulation in plasma physics

    International Nuclear Information System (INIS)

    Samarskii, A.A.

    1980-01-01

    Plasma physics is not only a field for development of physical theories and mathematical models but also an object of application of the computational experiment comprising analytical and numerical methods adapted for computers. The author considers only MHD plasma physics problems. Examples treated are dissipative structures in plasma; MHD model of solar dynamo; supernova explosion simulation; and plasma compression by a liner. (Auth.)

  6. Plasma-based accelerator structures

    International Nuclear Information System (INIS)

    Schroeder, Carl B.

    1999-01-01

    Plasma-based accelerators have the ability to sustain extremely large accelerating gradients, with possible high-energy physics applications. This dissertation further develops the theory of plasma-based accelerators by addressing three topics: the performance of a hollow plasma channel as an accelerating structure, the generation of ultrashort electron bunches, and the propagation of laser pulses is underdense plasmas

  7. Physics of partially ionized plasmas

    CERN Document Server

    Krishan, Vinod

    2016-01-01

    Plasma is one of the four fundamental states of matter; the other three being solid, liquid and gas. Several components, such as molecular clouds, diffuse interstellar gas, the solar atmosphere, the Earth's ionosphere and laboratory plasmas, including fusion plasmas, constitute the partially ionized plasmas. This book discusses different aspects of partially ionized plasmas including multi-fluid description, equilibrium and types of waves. The discussion goes on to cover the reionization phase of the universe, along with a brief description of high discharge plasmas, tokomak plasmas and laser plasmas. Various elastic and inelastic collisions amongst the three particle species are also presented. In addition, the author demonstrates the novelty of partially ionized plasmas using many examples; for instance, in partially ionized plasma the magnetic induction is subjected to the ambipolar diffusion and the Hall effect, as well as the usual resistive dissipation. Also included is an observation of kinematic dynam...

  8. Echo phenomena in a plasma

    International Nuclear Information System (INIS)

    Pavlenko, V.N.

    1983-01-01

    The mechanism of echo phenomenon in different plasma media: laboratory and cosmic plasma, metals and semiconductors is analyzed to get a more comprehensive idea on collective processes in a plasma and for practical applications in radiophysics and plasma diagnostics. The echo phenomenon permitted to confirm a reversible nature of the Landau damping, to prove the fact that the information on perturbation is conserved in a plasma (as non-damping oscillations of the distribution function) even after disappearing of the macroscopic field. The dependence of the diffusion coefficient on the velocity is measured, microturbulences in a plasma are investigated. New ways of the plasma wave conversion are suggested, as well as ''lightning'' of super-critical plasma layers and regions of plasma non-transparency. Prospective advantages of using echo for studying the mechanisms of charged particle interaction with the surface bounding a plasma are revealed

  9. Dust in flowing magnetized plasma

    International Nuclear Information System (INIS)

    Pandey, Birendra P.; Samarian, Alex A.; Vladimirov, Sergey V.

    2009-01-01

    Plasma flows occur in almost every laboratory device and interactions of flowing plasmas with near-wall impurities and/or dust significantly affects the efficiency and lifetime of such devices. The charged dust inside the magnetized flowing plasma moves primarily under the influence of the plasma drag and electric forces. Here, the charge on the dust, plasma potential, and plasma density are calculated self-consistently. The electrons are assumed non-Boltzmannian and the effect of electron magnetization and electron-atom collisions on the dust charge is calculated in a self-consistent fashion. For various plasma magnetization parameters viz. the ratio of the electron and ion cyclotron frequencies to their respective collision frequencies, plasma-atom and ionization frequencies, the evolution of the plasma potential and density in the flow region is investigated. The variation of the dust charge profile is shown to be a sensitive function of plasma parameters. (author)

  10. Úlceras por presión causadas por dispositivos clínicos

    OpenAIRE

    Iglesias Ruisánchez, Sandra

    2017-01-01

    Las úlceras por presión (UPP) son lesiones comunes en los pacientes hospitalizados, especialmente en las unidades de cuidados intensivos (UCI). Los enfermos críticos tienen un riesgo elevado de desarrollar UPP, debido principalmente a la limitación de la movilidad, disminuyendo su capacidad para cambiar activamente su posición en la cama o asiento. Además, el efecto de fármacos anestésicos y sedantes, puede causar una pérdida de la percepción sensorial cutánea. Los diferentes dispositivos clí...

  11. Plasma particle accelerators

    International Nuclear Information System (INIS)

    Dawson, J.M.

    1988-01-01

    The Superconducting Supercollider (SSC) will require an 87-kilometer accelerator ring to boost particles to 40 TeV. The SSC's size is due in part to the fact that its operating principle is the same one that has dominated accelerator design for 50 years: it guides particles by means of magnetic fields and propels them by strong electric fields. If one were to build an equally powerful but smaller accelerator, one would need to increase the strength of the guiding and propelling fields. Actually, however, conventional technology may not be able to provide significant increases in field strength. There are two reasons. First, the forces from magnetic fields are becoming greater than the structural forces that hold a magnetic material together; the magnets that produce these fields would themselves be torn apart. Second, the energy from electric fields is reaching the energies that bind electrons to atoms; it would tear electrons from nuclei in the accelerator's support structures. It is the electric field problem that plasma accelerators can overcome. Plasma particle accelerators are based on the principle that particles can be accelerated by the electric fields generated within a plasma. Because the plasma has already been ionized, plasma particle accelerators are not susceptible to electron dissociation. They can in theory sustain accelerating fields thousands of times stronger that conventional technologies. So far two methods for creating plasma waves for accelerators have been proposed and tested: the wakefield and the beat wave. Although promising electric fields have been produced, more research is necessary to determine whether plasma particle accelerators can compete with the existing accelerators. 7 figs

  12. Plasma state. The universe's fire

    International Nuclear Information System (INIS)

    Lehner, Th.

    2004-01-01

    The plasma is the fourth state of matter, obtained at a very high temperature by the separation of the electrons from their nuclei. Plasma represents 99% of the visible mass of our present day universe and was the unique state of matter at its very beginning. Plasmas are present in the core of stars and in the interstellar environment. More closer to us, they are responsible of spectacular phenomena, like aurora borealis, lightning, comet queues etc.. This book makes a review of the different types of plasmas (electromagnetic, Earth's plasmas, spatial plasmas, solar plasmas, astrophysical plasmas). One chapter presents the thermonuclear fusion as future energy source. Another one treats of the chaos and turbulence inside plasmas. Some applications of plasmas are reviewed: MHD and ionic propulsion systems, MHD energy conversion and MHD generators, thermo-ionic converters, solid-state plasmas, particle accelerators, coherent radiation sources, 'Zeta' machines, X-ray lasers, isotopic separation, non-neutral plasmas and charged beams, free-electrons lasers, electrons and positrons plasmas, industrial applications (etching and cleaning, manufacturing of solar cells, flat screens, industrial reactors, waste treatment, cold plasma-assisted sterilization, effluents decontamination etc.). A last chapter makes an overview of the modern research in plasma physics. (J.S.)

  13. Integrated modelling of the edge plasma and plasma facing components

    International Nuclear Information System (INIS)

    Coster, D.P.; Bonnin, X.; Mutzke, A.; Schneider, R.; Warrier, M.

    2007-01-01

    Modelling of the interaction between the edge plasma and plasma facing components (PFCs) has tended to place more emphasis on either the plasma or the PFCs. Either the PFCs do not change with time and the plasma evolution is studied, or the plasma is assumed to remain static and the detailed interaction of the plasma and the PFCs are examined, with no back-reaction on the plasma taken into consideration. Recent changes to the edge simulation code, SOLPS, now allow for changes in both the plasma and the PFCs to be considered. This has been done by augmenting the code to track the time-development of the properties of plasma facing components (PFCs). Results of standard mixed-materials scenarios (base and redeposited C; Be) are presented

  14. Low Temperature Plasma Medicine

    Science.gov (United States)

    Graves, David

    2013-10-01

    Ionized gas plasmas near room temperature are used in a remarkable number of technological applications mainly because they are extraordinarily efficient at exploiting electrical power for useful chemical and material transformations near room temperature. In this tutorial address, I will focus on the newest area of low temperature ionized gas plasmas (LTP), in this case operating under atmospheric pressure conditions, in which the temperature-sensitive material is living tissue. LTP research directed towards biomedical applications such as sterilization, surgery, wound healing and anti-cancer therapy has seen remarkable growth in the last 3-5 years, but the mechanisms responsible for the biomedical effects have remained mysterious. It is known that LTP readily create reactive oxygen species (ROS) and reactive nitrogen species (RNS). ROS and RNS (or RONS), in addition to a suite of other radical and non-radical reactive species, are essential actors in an important sub-field of aerobic biology termed ``redox'' (or oxidation-reduction) biology. I will review the evidence suggesting that RONS generated by plasmas are responsible for their observed therapeutic effects. Other possible bio-active mechanisms include electric fields, charges and photons. It is common in LTP applications that synergies between different mechanisms can play a role and I will review the evidence for synergies in plasma biomedicine. Finally, I will address the challenges and opportunities for plasma physicists to enter this novel, multidisciplinary field.

  15. Mechanisms of Plasma Therapeutics

    Science.gov (United States)

    Graves, David

    2015-09-01

    In this talk, I address research directed towards biomedical applications of atmospheric pressure plasma such as sterilization, surgery, wound healing and anti-cancer therapy. The field has seen remarkable growth in the last 3-5 years, but the mechanisms responsible for the biomedical effects have remained mysterious. It is known that plasmas readily create reactive oxygen species (ROS) and reactive nitrogen species (RNS). ROS and RNS (or RONS), in addition to a suite of other radical and non-radical reactive species, are essential actors in an important sub-field of aerobic biology termed ``redox'' (or oxidation-reduction) biology. It is postulated that cold atmospheric plasma (CAP) can trigger a therapeutic shielding response in tissue in part by creating a time- and space-localized, burst-like form of oxy-nitrosative stress on near-surface exposed cells through the flux of plasma-generated RONS. RONS-exposed surface layers of cells communicate to the deeper levels of tissue via a form of the ``bystander effect,'' similar to responses to other forms of cell stress. In this proposed model of CAP therapeutics, the plasma stimulates a cellular survival mechanism through which aerobic organisms shield themselves from infection and other challenges.

  16. 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.

  17. ITER plasma facing components

    International Nuclear Information System (INIS)

    Kuroda, T.; Vieider, G.; Akiba, M.

    1991-01-01

    This document summarizes results of the Conceptual Design Activities (1988-1990) for the International Thermonuclear Experimental Reactor (ITER) project, namely those that pertain to the plasma facing components of the reactor vessel, of which the main components are the first wall and the divertor plates. After an introduction and an executive summary, the principal functions of the plasma-facing components are delineated, i.e., (i) define the low-impurity region within which the plasma is produced, (ii) absorb the electromagnetic radiation and charged-particle flux from the plasma, and (iii) protect the blanket/shield components from the plasma. A list of critical design issues for the divertor plates and the first wall is given, followed by discussions of the divertor plate design (including the issues of material selection, erosion lifetime, design concepts, thermal and mechanical analysis, operating limits and overall lifetime, tritium inventory, baking and conditioning, safety analysis, manufacture and testing, and advanced divertor concepts) and the first wall design (armor material and design, erosion lifetime, overall design concepts, thermal and mechanical analysis, lifetime and operating limits, tritium inventory, baking and conditioning, safety analysis, manufacture and testing, an alternative first wall design, and the limiters used instead of the divertor plates during start-up). Refs, figs and tabs

  18. Plasma-Wall Interactions

    Energy Technology Data Exchange (ETDEWEB)

    Li, J; Chen, J L [Institute of Plasma Physics, Chinese Academy of Sciences (China); Guo, H Y [Tri Alpha Energy (United States); Institute of Plasma Physics, Chinese Academy of Sciences (China); McCracken, G M [Culham Science Centre, UKAEA, Abingdon (United Kingdom)

    2012-09-15

    The problem of impurities in fusion plasmas has been recognized since the beginning of the fusion programme. Early experiments in glass vacuum vessels released gas from the wall to such an extent that the radiation from the impurities prevented the plasma from being heated above about 50 eV. The radiative power loss is principally due to line radiation from partially stripped ions, which is particularly a problem during the plasma startup phase. Another problem is fuel dilution, which arises because impurity atoms produce many electrons and, for a given plasma pressure, these electrons take the place of fuel particles. Impurities can also lead to disruptions, as a result of edge cooling and consequent current profile modification. The fractional impurity level which radiates 10% of the total thermonuclear power for a 10 keV plasma is 50% for helium, 7% for carbon, and less than 0.1% for molybdenum. Clearly, impurities of low atomic number are a much less serious problem than those of high atomic number. (author)

  19. Plasma nuclear fusion method

    International Nuclear Information System (INIS)

    Yamazaki, Shunpei; Miyanaga, Shoji; Wakaizumi, Kazuhiro; Takemura, Yasuhiko.

    1990-01-01

    Nuclear fusion reactions are attained by plasma gas phase reactions using magnetic fields and microwaves, and the degree of the reactions is controlled. That is, deuterium (D 2 ) is introduced into a plasma container by utilizing the resonance of microwaves capable of generating plasmas at high density higher by more than 10 - 10 3 times as compared with the high frequency and magnetic fields, and an electric energy is applied to convert gaseous D 2 into plasmas and nuclear fusion is conducted. Further, the deuterium ions in the plasmas are attracted to a surface of a material causing nuclear fusion under a negatively biased electric field from the outside (typically represented by Pd or Ti). Then, deuterium nuclei (d) or deuterium ions collide to the surface of the cathode on the side of palladium to conduct nuclear reaction at the surface or the inside (vicinity) thereof. However, a DC bias is applied as an external bias with the side of the palladium being negative. The cold nuclear fusion was demonstrated by placing a neutron counter in the vicinity of the container and confirming neutrons generated there. (I.S.)

  20. Plasma-surface interactions

    International Nuclear Information System (INIS)

    Goeckner, M J; Nelson, C T; Sant, S P; Jindal, A K; Joseph, E A; Zhou, B S; Padron-Wells, G; Jarvis, B; Pierce, R; Overzet, L J

    2008-01-01

    Materials processing is at a crossroads. Currently a large fraction of industrially viable materials processing is via plasmas. Until recently it has been economical to just examine the influence the plasma properties on the desired surface processes and through this ultimately optimize manufacturing. For example, it is well known that the surface processes (etch or deposition), occur in the top few mono-layers of the surface. Thus, in film growth one requires that molecules from the gas-phase land and bond on the surface. However as processing has reached the nano-scale, development of viable processes has become more and more difficult. In part, this is because of all of the free parameters that exist in plasmas. To overcome this economic issue, tool vendors and semiconductor companies have turned to complex computational models of processing plasmas. For those models to work, one requires a through understanding of all of the gas-phase and surface-phase processes that are exhibited in plasmas. Unfortunately, these processes, particularly those at the surface, are not well understood. In this article we describe a viable model of the surface-phase based on cross sections for processes that occur. While originally developed of fluorocarbon systems, the model also appears to be applicable to hydrocarbon systems.

  1. Plasma-surface interactions

    Energy Technology Data Exchange (ETDEWEB)

    Goeckner, M J; Nelson, C T; Sant, S P; Jindal, A K; Joseph, E A; Zhou, B S; Padron-Wells, G; Jarvis, B; Pierce, R; Overzet, L J [Department of Electrical Engineering, University of Texas at Dallas (United States)], E-mail: goeckner@utdallas.edu

    2008-10-01

    Materials processing is at a crossroads. Currently a large fraction of industrially viable materials processing is via plasmas. Until recently it has been economical to just examine the influence the plasma properties on the desired surface processes and through this ultimately optimize manufacturing. For example, it is well known that the surface processes (etch or deposition), occur in the top few mono-layers of the surface. Thus, in film growth one requires that molecules from the gas-phase land and bond on the surface. However as processing has reached the nano-scale, development of viable processes has become more and more difficult. In part, this is because of all of the free parameters that exist in plasmas. To overcome this economic issue, tool vendors and semiconductor companies have turned to complex computational models of processing plasmas. For those models to work, one requires a through understanding of all of the gas-phase and surface-phase processes that are exhibited in plasmas. Unfortunately, these processes, particularly those at the surface, are not well understood. In this article we describe a viable model of the surface-phase based on cross sections for processes that occur. While originally developed of fluorocarbon systems, the model also appears to be applicable to hydrocarbon systems.

  2. Optical plasma torch electron bunch generation in plasma wakefield accelerators

    Directory of Open Access Journals (Sweden)

    G. Wittig

    2015-08-01

    Full Text Available A novel, flexible method of witness electron bunch generation in plasma wakefield accelerators is described. A quasistationary plasma region is ignited by a focused laser pulse prior to the arrival of the plasma wave. This localized, shapeable optical plasma torch causes a strong distortion of the plasma blowout during passage of the electron driver bunch, leading to collective alteration of plasma electron trajectories and to controlled injection. This optically steered injection is more flexible and faster when compared to hydrodynamically controlled gas density transition injection methods.

  3. Mujeres por la utilidad de la virtud

    Directory of Open Access Journals (Sweden)

    Nancy Rodríguez Pupo

    2014-08-01

    Full Text Available La mujer cubana ostenta una vasta tradición combativa y es ejemplo de entereza, abnegación, sacrificio y compromiso social. Quien se acerque a la historia de nuestro proceso nacional-liberador a todo lo largo de su devenir, constatará su presencia como forjadoras de la nación. Integrante fundamental de la sociedad, la mujer hizo suyas las ansias libertadoras y desempeñó un rol importante en aras de crear una patria común. Se trata de entender que en lo más mínimo su papel fue de “retaguardia”, sino todo lo contrario, su trabajo fue necesario y en no pocas ocasiones empuñó las armas y con valentía gritó ¡viva Cuba libre!, incluso a cambio de su vida, como lo protagonizó la tunera Mercedes Varona. El ejemplo de la mujer cubana y particularmente tunera, es imperecedero en su doble función de ser social y generadora de nuevas vidas, con amplias posibilidades de realización personal y profesional luego de 1959. Su actuación se manifiesta en cada actividad del sector de la salud pública como médica, enfermera, técnica, profesora y estomatóloga, así como también en otros puestos de trabajo no menos necesarios. Ellas con altruismo, solidaridad, responsabilidad y humanismo, son continuadoras de las mejores tradiciones científicas, patrióticas y revolucionarias de nuestro pueblo. Esta edición se dedica al 8 de marzo, día internacional de la mujer, las homenajeamos y recordamos la obra de Laura Martínez Carvajal, primera médica cubana, quien desafió los prejuicios de su época o Isabel Rubio que puso sus conocimientos de medicina farmacéutica al servicio del Ejército Libertador, en el que alcanzó los grados de capitana de sanidad; por citar dos entre las grandes. Otras féminas de la localidad ejercieron en la manigua sus dotes de parteras o enfermeras, tal el caso de Anita Cruz, magnífica artillera, quien estuvo al frente de un hospital de campaña durante la guerra. Allí curó heridas, infecciones, disenter

  4. Plasma cleaning for waste minimization

    Energy Technology Data Exchange (ETDEWEB)

    Ward, P.P.

    1993-07-01

    Although plasma cleaning is a recognized substitute for solvent cleaning in removing organic contaminants, some universal problems in plasma cleaning processes prevent wider use of plasma techniques. Lack of understanding of the fundamental mechanisms of the process, unreliable endpoint detection techniques, and slow process times make plasma cleaning processes less than desirable. Our approach to address these plasma cleaning problems is described. A comparison of plasma cleaning rates of oxygen and oxygen/sulfur hexafluoride gases shows that fluorine-containing plasmas can enhance etch rates by 400% over oxygen alone. A discussion of various endpoint indication techniques is discussed and compared for application suitability. Work toward a plasma cleaning database is discussed. In addition to the global problems of plasma cleaning, an experiment where the specific mixed-waste problem of removal of machine oils from radioactive scrap metal is discussed.

  5. Plasma Colloquium Travel Grant Program

    International Nuclear Information System (INIS)

    Hazeltine, R.D.

    1998-01-01

    OAK B188 Plasma Colloquium Travel Grant Program. The purpose of the Travel Grant Program is to increase the awareness of plasma research. The new results and techniques of plasma research in fusion plasmas, plasma processing space plasmas, basic plasma science, etc, have broad applicability throughout science. The benefits of these results are limited by the relatively low awareness and appreciation of plasma research in the larger scientific community. Whereas spontaneous interactions between plasma scientists and other scientists are useful, a focused effort in education and outreach to other scientists is efficient and is needed. The academic scientific community is the initial focus of this effort, since that permits access to a broad cross-section of scientists and future scientists including undergraduates, graduate students, faculty, and research staff

  6. Atoms in dense plasmas

    International Nuclear Information System (INIS)

    More, R.M.

    1987-01-01

    This paper covers some aspects of the theory of atomic processes in dense plasmas. Because the topic is very broad, a few general rules which give useful guidance about the typical behavior of dense plasmas have been selected. These rules are illustrated by semiclassical estimates, scaling laws and appeals to more elaborate calculations. Included in the paper are several previously unpublished results including a new mechanism for electron-ion heat exchange (section II), and an approximate expression for oscillator-strengths of highly charged ions (section V). However the main emphasis is not upon practical formulas but rather on questions of fundamental theory, the structural ingredients which must be used in building a model for plasma events. What are the density effects and how does one represent them? Which are most important? How does one identify an incorrect theory? The general rules help to answer these questions. 106 references, 23 figures, 2 tables

  7. Corpuscular plasma diagnostics

    International Nuclear Information System (INIS)

    Afrosimov, V.; Petrov, M.

    1984-01-01

    An elementary explanation is presented of the physical principles and important methods of corpuscular plasma diagnostics. The invaluable role of corpuscular methods for measuring the hot plasma ion component in thermonuclear facilities, especially hydrogen ions in tokamaks, is emphasized. All corpuscular methods employ analysis of fast neutral atoms and therefore the mechanism of their creation inside a hot plasma is explained first. The ammount of information obtainable from spectra of fast neutrals is discussed. Multichannel analyzers developed at the FTI A.F. Ioffe in Leningrad are described in detail. Classical passive corpuscular diagnostics are examined as are active methods using artifitial beams of hydrogen atoms. The method used for obtaining local values of ion temperature and density is explained. Corpuscular spectroscopic diagnostics and its application for measuring impurities is mentioned. (J.U.)

  8. Plasma cell leukemia

    DEFF Research Database (Denmark)

    Fernández de Larrea, C; Kyle, R A; Durie, B G M

    2013-01-01

    Plasma cell leukemia (PCL) is a rare and aggressive variant of myeloma characterized by the presence of circulating plasma cells. It is classified as either primary PCL occurring at diagnosis or as secondary PCL in patients with relapsed/refractory myeloma. Primary PCL is a distinct clinic......-pathological entity with different cytogenetic and molecular findings. The clinical course is aggressive with short remissions and survival duration. The diagnosis is based upon the percentage (≥ 20%) and absolute number (≥ 2 × 10(9)/l) of plasma cells in the peripheral blood. It is proposed that the thresholds...... regimens and bortezomib-based regimens are recommended followed by high-dose therapy with autologous stem cell transplantation if feasible. Allogeneic transplantation can be considered in younger patients. Prospective multicenter studies are required to provide revised definitions and better understanding...

  9. Plasma processing of nanomaterials

    CERN Document Server

    Sankaran, R Mohan

    2014-01-01

    CRC Press author R. Mohan Sankaran is the winner of the 2011 Peter Mark Memorial Award "… for the development of a tandem plasma synthesis method to grow carbon nanotubes with unprecedented control over the nanotube properties and chirality." -2011 AVS Awards Committee"Readers who want to learn about how nanomaterials are processed, using the most recent methods, will benefit greatly from this book. It contains very recent technical details on plasma processing and synthesis methods used by current researchers developing new nano-based materials, with all the major plasma-based processing techniques used today being thoroughly discussed."-John J. Shea, IEEE Electrical Insulation Magazine, May/June 2013, Vol. 29, No. 3.

  10. [Plasma properties: Annual report

    International Nuclear Information System (INIS)

    1987-01-01

    The Magneto-Fluid Dynamics Division of the Courant Institute is engaged in a broad program of basic research in the theoretical aspects of plasma physics and magneto-fluid dynamics with emphasis on those areas which are relevant to the fusion energy program. The total research program in the division includes efforts in the areas of plasma containment, stability, equilibrium, transport, wave propagation (including shock waves), heating, orbit theory, as well as numerical experiments and the development of practical numerical methods in all plasma problems. Applications are made to the following project areas: Tokamaks, Mirrors, Stellarators, and Alternate Concepts. Developments include the whole spectrum of models from macroscopic MHD and guiding center to Vlasov, drift kinetic Fokker-Planck, and Boltzmann. This document describes research completed as well as programs in progress

  11. Heating in toroidal plasmas

    International Nuclear Information System (INIS)

    Knoepfel, H.; Mazzitelli, G.

    1984-01-01

    The article is a rather detailed report on the highlights in the area of the ''Heating in toroidal plasmas'', as derived from the presentations and discussions at the international symposium with the same name, held in Rome, March 1984. The symposium covered both the physics (experiments and theory) and technology of toroidal fusion plasma heating. Both large fusion devices (either already in operation or near completion) requiring auxiliary heating systems at the level of tens of megawatts, as well as physics of their heating processes and their induced side effects (as studied on smaller devices), received attention. Substantial progress was reported on the broad front of auxiliary plasma heating and Ohmic heating. The presentation of the main conclusions of the symposium is divided under the following topics: neutral-beam heating, Alfven wave heating, ion cyclotron heating, lower hybrid heating, RF current drive, electron cyclotron heating, Ohmic heating and special contributions

  12. Relativistic plasma dispersion functions

    International Nuclear Information System (INIS)

    Robinson, P.A.

    1986-01-01

    The known properties of plasma dispersion functions (PDF's) for waves in weakly relativistic, magnetized, thermal plasmas are reviewed and a large number of new results are presented. The PDF's required for the description of waves with small wave number perpendicular to the magnetic field (Dnestrovskii and Shkarofsky functions) are considered in detail; these functions also arise in certain quantum electrodynamical calculations involving strongly magnetized plasmas. Series, asymptotic series, recursion relations, integral forms, derivatives, differential equations, and approximations for these functions are discussed as are their analytic properties and connections with standard transcendental functions. In addition a more general class of PDF's relevant to waves of arbitrary perpendicular wave number is introduced and a range of properties of these functions are derived

  13. Impacto do manejo da água na toxidez por ferro no arroz irrigado por alagamento

    Directory of Open Access Journals (Sweden)

    Fabiana Schmidt

    2013-10-01

    Full Text Available A toxidez por ferro é o distúrbio nutricional de maior ocorrência em arroz (Oryza sativa L. cultivado em sistemas alagados, derivada da quantidade excessiva de íons ferrosos (Fe2+ gerados pela redução de óxidos de ferro em solos alagados. Em experimento conduzido em casa de vegetação, foram avaliados os efeitos de manejos da água de irrigação na dinâmica de redução de um Planossolo e na manifestação da toxidez por ferro em arroz. Os tratamentos dispostos em blocos completos ao acaso com quatro repetições constaram de cinco manejos da água: T1- início do alagamento no estádio V2-V3 do arroz; T2- início do alagamento no estádio V6-V7; T3- T1 e drenagem no estádio V10-V11; T4- T2 e drenagem no estádio V10-V11; e T5- T1 e drenagens nos estádios V7-V8 e V10-V11. O atraso do início do alagamento para o estádio V6-V7 do arroz manteve os valores do Eh da solução do solo mais elevados, promovendo menor disponibilidade de Fe2+ na solução do solo e deslocando a máxima liberação de Fe2+ na solução do solo para estádios fenológicos mais avançados do arroz. A realização de drenagens ao longo do ciclo vegetativo do arroz promoveu a reoxidação do solo, que ocasionou o aumento dos valores de Eh e redução da concentração de Fe2+ na solução do solo. O uso de drenagens durante o período vegetativo do arroz foi eficiente no controle da toxidez por excesso de ferro, em arroz cultivado em solo alagado.

  14. Plasma Simulation Program

    Energy Technology Data Exchange (ETDEWEB)

    Greenwald, Martin

    2011-10-04

    Many others in the fusion energy and advanced scientific computing communities participated in the development of this plan. The core planning team is grateful for their important contributions. This summary is meant as a quick overview the Fusion Simulation Program's (FSP's) purpose and intentions. There are several additional documents referenced within this one and all are supplemental or flow down from this Program Plan. The overall science goal of the DOE Office of Fusion Energy Sciences (FES) Fusion Simulation Program (FSP) is to develop predictive simulation capability for magnetically confined fusion plasmas at an unprecedented level of integration and fidelity. This will directly support and enable effective U.S. participation in International Thermonuclear Experimental Reactor (ITER) research and the overall mission of delivering practical fusion energy. The FSP will address a rich set of scientific issues together with experimental programs, producing validated integrated physics results. This is very well aligned with the mission of the ITER Organization to coordinate with its members the integrated modeling and control of fusion plasmas, including benchmarking and validation activities. [1]. Initial FSP research will focus on two critical Integrated Science Application (ISA) areas: ISA1, the plasma edge; and ISA2, whole device modeling (WDM) including disruption avoidance. The first of these problems involves the narrow plasma boundary layer and its complex interactions with the plasma core and the surrounding material wall. The second requires development of a computationally tractable, but comprehensive model that describes all equilibrium and dynamic processes at a sufficient level of detail to provide useful prediction of the temporal evolution of fusion plasma experiments. The initial driver for the whole device model will be prediction and avoidance of discharge-terminating disruptions, especially at high performance, which are a

  15. Pulsed Plasma Electron Sources

    Science.gov (United States)

    Krasik, Yakov

    2008-11-01

    Pulsed (˜10-7 s) electron beams with high current density (>10^2 A/cm^2) are generated in diodes with electric field of E > 10^6 V/cm. The source of electrons in these diodes is explosive emission plasma, which limits pulse duration; in the case E Saveliev, J. Appl. Phys. 98, 093308 (2005). Ya. E. Krasik, A. Dunaevsky, and J. Felsteiner, Phys. Plasmas 8, 2466 (2001). D. Yarmolich, V. Vekselman, V. Tz. Gurovich, and Ya. E. Krasik, Phys. Rev. Lett. 100, 075004 (2008). J. Z. Gleizer, Y. Hadas and Ya. E. Krasik, Europhysics Lett. 82, 55001 (2008).

  16. Plasma diagnostic reflectometry

    International Nuclear Information System (INIS)

    Cohen, B.I.; Afeyan, B.B.; Garrison, J.C.; Kaiser, T.B.; Luhmann, N.C. Jr.; Domier, C.W.; Chou, A.E.; Baang, S.

    1996-01-01

    Theoretical and experimental studies of plasma diagnostic reflectometry have been undertaken as a collaborative research project between the Lawrence Livermore National Laboratory (LLNL) and the University of California Department of Applied Science Plasma Diagnostics Group under the auspices of the Laboratory Directed Research and Development Program at LLNL. Theoretical analyses have explored the basic principles of reflectometry to understand its limitations, to address specific gaps in the understanding of reflectometry measurements in laboratory experiments, and to explore extensions of reflectometry such as ultra-short-pulse reflectometry. The theory has supported basic laboratory reflectometry experiments where reflectometry measurements can be corroborated by independent diagnostic measurements

  17. Protective plasma envelope

    International Nuclear Information System (INIS)

    Bocharov, V.N.; Konstantinov, S.G.; Kudryavtsev, A.M.; Myskin, O.K.; Panasyuk, V.M.; Tsel'nik, F.A.

    1984-06-01

    A method of creating an annular plasma envelope used to protect the hot plasma from flows of impurities and gases from the walls of the vacuum chamber is described. The diameter of the envelope is 30 cm, the thickness of the wall is 1.5 cm, the length is 2.5 m, and its density is from 10 13 to 10 14 cm -3 . The envelope attenuates the incident (from outside) flow of helium 10-fold and the low of hydrogen 20-fold

  18. Plasma fractionation issues.

    Science.gov (United States)

    Farrugia, Albert; Evers, Theo; Falcou, Pierre-Francois; Burnouf, Thierry; Amorim, Luiz; Thomas, Sylvia

    2009-04-01

    Procurement and processing of human plasma for fractionation of therapeutic proteins or biological medicines used in clinical practice is a multi-billion dollar international trade. Together the private sector and public sector (non-profit) provide large amounts of safe and effective therapeutic plasma proteins needed worldwide. The principal therapeutic proteins produced by the dichotomous industry include gamma globulins or immunoglobulins (including pathogen-specific hyperimmune globulins, such as hepatitis B immune globulins) albumin, factor VIII and Factor IX concentrates. Viral inactivation, principally by solvent detergent and other processes, has proven highly effective in preventing transmission of enveloped viruses, viz. HBV, HIV, and HCV.

  19. Dust-Plasma Interactions

    International Nuclear Information System (INIS)

    Rosenberg, M.

    2010-01-01

    The objective of our theoretical research under this grant over the past 3 years was to develop new understanding in a range of topics in the physics of dust-plasma interactions, with application to space and the laboratory. We conducted studies related to the physical properties of dust, waves and instabilities in both weakly coupled and strongly coupled dusty plasmas, and innovative possible applications. A major consideration in our choice of topics was to compare theory with experiments or observations, and to motivate new experiments, which we believe is important for developing this relatively new field. Our research is summarized, with reference to our list of journal publications.

  20. Plasma YKL-40

    DEFF Research Database (Denmark)

    Jensen, Peter; Wiell, C; Milting, K

    2013-01-01

    Background  Plasma YKL-40 is an inflammatory biomarker. No useful biomarker exists in patients with psoriasis or psoriatic arthritis. Objective  To measure YKL-40 and high-sensitivity C-reactive protein (hs-CRP) in patients with psoriasis or psoriatic arthritis before and during treatment. Methods......-CRP at inclusion and during 48 weeks of adalimumab treatment. The patients with psoriatic arthritis were divided into responders and non-responders. Results  In patients with psoriasis, the baseline median PASI score was 10.8 and baseline YKL-40 was 45 μg/L. Seventeen per cent had elevated plasma YKL-40 compared...

  1. Steam torch plasma modelling

    Czech Academy of Sciences Publication Activity Database

    Jeništa, Jiří

    2017-01-01

    Roč. 37, č. 3 (2017), s. 653-687 ISSN 0272-4324 R&D Projects: GA ČR(CZ) GA15-19444S Institutional support: RVO:61389021 Keywords : Arc * Evaporation * Mass flow rate * Water-vortex stabilization * Net emission coefficients * Partial characteristics * Local thermodynamic equilibrium Subject RIV: BL - Plasma and Gas Discharge Physics OBOR OECD: Fluids and plasma physics (including surface physics) Impact factor: 2.355, year: 2016 http://link.springer.com/article/10.1007/s11090-017-9789-7

  2. Measurement of plasma parameters

    International Nuclear Information System (INIS)

    1999-01-01

    The physics issues of the measurements of the plasma properties necessary to provide both the control and science data for achieving the goals of the ITER device are discussed. The assessment of the requirements for these measurements is first discussed, together with priorities that relate to the experimental program. Subsequently, some of the proposed measurement techniques, the plasma diagnostics, are described with particular emphasis on their implementation on ITER and their capability to meet the requirements. A judgement on the present status of the diagnostic program on ITER is provided with some indication of the research and development program necessary to demonstrate viability of techniques or their implementation. (author)

  3. Plasma wave accelerator. II

    International Nuclear Information System (INIS)

    Mori, W.; Joshi, C.; Dawson, J.M.

    1982-01-01

    It was shown that the insertion of a cross magnetic field prevents the particles from getting out of phase with the electric field of the plasma wave in the beat wave accelerator scheme. Thus, using a CO 2 laser, n/sub c//n/sub e/ = (ω 0 /ω/sub p/) 2 approx. 35, and a 300 kG magnetic field, electrons can be (in principle) accelerated to 100 GeV in 2 meters. For comparison without the magnetic field, the same energies may be obtained in a n/sub c//n/sub e/ approx. 10 5 plasma over a distance of 100 meters

  4. Plasma-wall interactions

    International Nuclear Information System (INIS)

    Behrisch, Rainer

    1978-01-01

    The plasma wall interactions for two extreme cases, the 'vacuum model' and the 'cold gas blanket' are outlined. As a first step for understanding the plasma wall interactions the elementary interaction processes at the first wall are identified. These are energetic ion and neutral particle trapping and release, ion and neutral backscattering, ion sputtering, desorption by ions, photons and electrons and evaporation. These processes have only recently been started to be investigated in the parameter range of interest for fusion research. The few measured data and their extrapolation into regions not yet investigated are reviewed

  5. Liver resection in metastatic colorectal cancer: a multidisciplinary approach Resección hepática por metástasis de cáncer colorrectal: una visión multidisciplinar

    Directory of Open Access Journals (Sweden)

    J. F. Noguera Aguilar

    2005-11-01

    combinada a otras técnicas. Resultados: la mortalidad postoperatoria a los 30 días fue del 4%. Presentaron complicaciones el 28%, siendo la complicación más frecuente la infección de la herida quirúrgica (20%. Se transfundieron el 16,6% de los pacientes, con una necesidad transfusional media de 1000 cc. Dos casos precisaron reintervención (8%, en un caso precoz por absceso intraabdominal, y en otro caso tardía, por estenosis de la vía biliar principal. El porcentaje de recaídas global es del 36%, siendo más frecuente la extrahepática (26%. La supervivencia actuarial al año de seguimiento es del 90 y del 82% a los dos años. Se hallaban libres de enfermedad a los dos años el 64% de los pacientes. Conclusiones: los programas de resección hepática de metástasis de cáncer colorrectal pueden ser implantados por equipos multidisciplinares de reciente creación, si bien existe la necesidad de auditarse y situarse dentro de los parámetros de calidad.

  6. Optical properties of cluster plasma

    Energy Technology Data Exchange (ETDEWEB)

    Kishimoto, Yasuaki; Tajima, Toshiki [Japan Atomic Energy Research Inst., Neyagawa, Osaka (Japan). Kansai Research Establishment; Downer, M C

    1998-03-01

    It is shown that unlike a gas plasma or an electron plasma in a metal, an ionized clustered material (`cluster plasma`) permits propagation below the plasma cut-off of electromagnetic (EM) waves whose phase velocity is close to but below the speed of light. This results from the excitation of a plasma oscillation mode (and/or polarization mode) through the cluster surface which does not exist in usual gaseous plasma. The existence of this new optical mode, cluster mode, is confirmed via numerical simulation. (author)

  7. Plasma effects on subcellular structures

    International Nuclear Information System (INIS)

    Gweon, Bomi; Kim, Dan Bee; Jung, Heesoo; Choe, Wonho; Kim, Daeyeon; Shin, Jennifer H.

    2010-01-01

    Atmospheric pressure helium plasma treated human hepatocytes exhibit distinctive zones of necrotic and live cells separated by a void. We propose that plasma induced necrosis is attributed to plasma species such as oxygen radicals, charged particles, metastables and/or severe disruption of charged cytoskeletal proteins. Interestingly, uncharged cytoskeletal intermediate filaments are only minimally disturbed by plasma, elucidating the possibility of plasma induced electrostatic effects selectively destroying charged proteins. These bona fide plasma effects, which inflict alterations in specific subcellular structures leading to necrosis and cellular detachment, were not observed by application of helium flow or electric field alone.

  8. Dynamic plasma screening effects on atomic collisions in dense plasmas

    International Nuclear Information System (INIS)

    Young-Dae Jung

    1999-01-01

    Dynamic plasma screening effects are investigated on electron-ion collisional excitation and Coulomb Bremsstrahlung processes in dense plasmas. The electron-ion interaction potential is considered by introduction of the plasma dielectric function. The straight-ling trajectory method is applied to the path of the projectile electron. The transition probability including the dynamic plasma screening effect is found to be always greater than that including the static plasma screening effects. It is found that the differential Bremsstrahlung radiation cross section including the dynamic plasma screening effect is also greater than that including the static plasma screening effect. When the projectile velocity is smaller than the electron thermal velocity, the dynamic polarization screening effect becomes the static plasma screening effect. However, when the projectile velocity is greater than the electron thermal velocity, the interaction potential is almost unshielded

  9. Observation of plasma hole in a rotating plasma

    International Nuclear Information System (INIS)

    Nagaoka, Kenichi; Ishihara, Tatsuzo; Okamoto, Atsushi; Yoshimura, Shinji; Tanaka, Masayoshi Y.

    2001-01-01

    Plasma hole, a cylindrical density cavity, formed in a rotating plasma has been investigated experimentally. The plasma hole is characterized by large aspect ratio (length/radius ≥ 30), steep boundary layer between the hole and the ambient plasma (10 ion Larmor radius), and extremely high positive potential (130 V). The flow velocity field associated with plasma hole structure has been measured, and is found to have interesting features: (1) plasma rotates in azimuthal direction at a maximum velocity of order of ion sound speed, (2) plasma flows radially inward across the magnetic field line, (3) there present an axial flow reversal between core and peripheral region. It is found that the flow pattern of the plasma hole is very similar to the that of well-developed typhoon with core. (author)

  10. Partially ionized plasmas including the third symposium on uranium plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Krishnan, M. [ed.

    1976-09-01

    Separate abstracts are included for 28 papers on electrically generated plasmas, fission generated plasmas, nuclear pumped lasers, gaseous fuel reactor research, and applications. Five papers have been previously abstracted and included in ERA.

  11. Influência do nitrogênio adicionado por SHTPN na resistência à erosão por cavitação do aço inoxidável martensítico

    OpenAIRE

    Maftoum, Ricardo de Almeida

    2013-01-01

    Muitos estudos são realizados para melhorar a resistência à erosão por cavitação dos aços. Entre estes estudos, está a utilização de aços inoxidáveis enriquecidos com nitrogênio na superfície. O presente trabalho estudou o uso da técnica SHTPN (Solution Heat Treatment after Plasma Nitriding), que consiste em duas etapas. Primeiro utiliza-se a nitretação a plasma, para inserir o nitrogênio no material. Na sequência realiza-se o tratamento térmico de solubilização, para que o nitrogênio fique e...

  12. Ansiedad percibida por los pacientes hospitalizados por quemaduras, en una Unidad de Quemados

    Directory of Open Access Journals (Sweden)

    M. Alcázar-Gabás

    2014-06-01

    Full Text Available El presente trabajo, pretende describir el estado de ansiedad que experimentan los pacientes ingresados en una Unidad de Quemados. Uno de los factores clave en los cuidados del paciente quemado es una buena atención psicológica. La realidad demuestra que es el profesional de enfermería quien observa los síntomas emocionales durante los primeros días de ingreso y trata de responder a esa demanda de cuidado. Pretendemos, a través de la medición del nivel de ansiedad que perciben los pacientes ingresados en la Unidad de Quemados elegida para nuestro estudio durante el primer semestre del año 2009, identificar a aquellos que estén en riesgo de padecer mayores niveles de ansiedad durante su hospitalización, para así poder establecer un plan de cuidados adaptado a las necesidades emocionales de cada uno. Los resultados obtenidos nos permiten concluir que los pacientes quemados ingresados en la Unidad de Quemados presentaron niveles elevados de ansiedad que son superiores entre la población femenina, así como en aquellos pacientes con lesiones de mayor extensión. Determinamos también que los pacientes ingresados por quemaduras en la Unidad de Quemados a estudio fueron mayoritariamente varones, de nacionalidad española, residentes en medio urbano con una media de edad de 50 años, siendo las quemaduras producidas por llama en accidentes domésticos la causa más frecuente.

  13. Escenarios de costos generados por el uso del costeo variable

    OpenAIRE

    Zea Lourido, Felipe

    2013-01-01

    Este trabajo demuestra cómo el costeo absorbente, considerado por expertos en la materia, uno de los métodos de costeo usado frecuentemente por las organizaciones, con el propósito de determinar el valor de los inventarios y del costo de productos vendidos que intervienen en el estado de resultados para usuarios externos (stakeholders), al compararlo con el costeo variable, preferido por algunos administradores para toma de decisiones internas y usado en la preparación del estado de resultado...

  14. Itinerarios didácticos por la isla de Tenerife

    OpenAIRE

    Becerra Ramírez, María Carmen; Javier Dóniz-Páez; González Cárdenas, Elena; Gosálvez, Rafael U.; Becerra-Ramírez, Rafael; Escobar Lahoz, Estela

    2013-01-01

    Con la elaboración de esta guía de Itinerarios Didácticos por la isla de Tenerife pretendemos contribuir a un mayor conocimiento de las características geográficas de un espacio dominado por las formas y formaciones volcánicas que caracterizan un paisaje fuertemente modificado por la actividad humana. El hombre convive y usa lo que los volcanes le ofrecen, tradicionalmente como soporte de sus cultivos o de su actividad ganadera,y modernamente como base de la industria turística. Los itiner...

  15. Topoplastia de Cvintal assistida por laser de femtossegundo

    Directory of Open Access Journals (Sweden)

    Alexandre Takayoshi Ishizaki

    2013-06-01

    Full Text Available Apresentamos um relato de astigmatismo tardio progressivo pós-transplante de córnea para ceratocone, associado à afinamento periférico na junção doador-receptor, o que presumidamente pode ser considerado como recorrência da ectasia. O caso foi tratado por meio de Topoplastia de Cvintal assistida por laser de femtossegundo para a confecção da incisão com geometria "top hat", seguido de sutura com ajuste per-operatório guiado por ceratoscopia.

  16. Selección de Recursos Humanos por Competencias

    OpenAIRE

    Sánchez Domingo, Cristina

    2013-01-01

    Los objetivos de este trabajo son, por un lado conocer en qué consisten los procesos de valoración y selección de personas desde el enfoque de las competencias laborales. Para ello, ha sido preciso profundizar en el estudio del concepto de “competencia laboral”, y comprender qué es la Gestión de Recursos Humanos por Competencias, en cuyo seno se encuentra la propia Selección de Recursos Humanos. Por otra parte, un segundo objetivo del trabajo es conocer el grado de implantación de la Selecció...

  17. Orlando Castellanos. La pasión por la radio

    OpenAIRE

    Castellanos Molina, Orlando, 1930-1998

    2004-01-01

    Documento sonoro en el que se recogen entrevistas realizadas a Orlando Castellanos por Miguel Ángel de la Guardia, Miladys Ochoa, Fernando Rodríguez Sánchez (Ciego de Ávila), Ángel Ferrera, Boshmonar, Jaime Almiral, Radio Umbral de Santiago de Chile, Franco Carbón, Luis Toledo Sande y Estrella Díaz. Esta grabación pertenece a la colección Palabra Viva, desarrollada por el Centro Cultural Pablo de la Torriente Brau, a partir de las entrevistas realizadas por el periodista Orlando Castellanos. ...

  18. Review on plasmas in extraordinary media: plasmas in cryogenic conditions and plasmas in supercritical fluids

    Science.gov (United States)

    Stauss, Sven; Muneoka, Hitoshi; Terashima, Kazuo

    2018-02-01

    Plasma science and technology has enabled advances in very diverse fields: micro- and nanotechnology, chemical synthesis, materials fabrication and, more recently, biotechnology and medicine. While many of the currently employed plasma tools and technologies are very advanced, the types of plasmas used in micro- and nanofabrication pose certain limits, for example, in treating heat-sensitive materials in plasma biotechnology and plasma medicine. Moreover, many physical properties of plasmas encountered in nature, and especially outer space, i.e. very-low-temperature plasmas or plasmas that occur in high-density media, are not very well understood. The present review gives a short account of laboratory plasmas generated under ’extreme’ conditions: at cryogenic temperatures and in supercritical fluids. The fundamental characteristics of these cryogenic plasmas and cryoplasmas, and plasmas in supercritical fluids, especially supercritical fluid plasmas, are presented with their main applications. The research on such exotic plasmas is expected to lead to further understanding of plasma physics and, at the same time, enable new applications in various technological fields.

  19. Double plasma system with inductively coupled source plasma and quasi-quiescent target plasma

    International Nuclear Information System (INIS)

    Massi, M.; Maciel, H.S.

    1995-01-01

    Cold plasmas have successfully been used in the plasma-assisted material processing industry. An understanding of the physicochemical mechanisms involved in the plasma-surface interaction is needed for a proper description of deposition and etching processes at material surfaces. Since these mechanisms are dependent on the plasma properties, the development of diagnostic techniques is strongly desirable for determination of the plasma parameters as well as the characterization of the electromagnetic behaviour of the discharge. In this work a dual discharge chamber, was specially designed to study the deposition of thin films via plasma polymerization process. In the Pyrex chamber an inductively coupled plasma can be excited either in the diffuse low density E-mode or in the high density H-mode. This plasma diffuses into the cylindrical stainless steel chamber which is covered with permanent magnets to produce a multidipole magnetic field configuration at the surface. By that means a double plasma is established consisting of a RF source plasma coupled to a quasi-quiescent target plasma. The preliminary results presented here refer to measurements of the profiles of plasma parameters along the central axis of the double plasma apparatus. Additionally a spectrum analysis performed by means of a Rogowski coil probe immersed into the source plasma is also presented. The discharge is made in argon with pressure varying from 10 -2 to 1 torr, and the rf from 10 to 150 W

  20. Nuevas recomendaciones para el tratamiento de personas con infección por VIH

    Directory of Open Access Journals (Sweden)

    2003-01-01

    Full Text Available Las recomendaciones más recientes del Departamento de Salud y Servicios Sociales de los Estados Unidos de América, que fueron emitidas en julio de 2003, tienen por finalidad facilitar la elección de un régimen de tratamiento para personas infectadas por el VIH, habida cuenta de la gran variedad de fármacos antirretrovírticos que han surgido en años recientes. Los fármacos que han mostrado mayor eficacia y que constituyen la base del tratamiento actual pertenecen a tres grandes grupos terapéuticos: los inhibidores nucleosídicos de la transcriptasa inversa, los inhibidores no nucleosídicos de la transcriptasa inversa y los inhibidores de las proteinasas. Son estos grupos, a su vez, los que integran los llamados regímenes conservadores de grupos terapéuticos, cuya finalidad es dejar de reserva para el futuro algunos grupos de fármacos por si se presenta resistencia a los utilizados inicialmente. El tratamiento de la infección por VIH con antirretrovíricos es complejo y difícil de cumplir, dado el elevado número de pastillas y de dosis diarias, y antes de iniciarse en pacientes asintomáticos es de rigor sopesar sus ventajas y beneficios. En la decisión es indispensable tener en cuenta el deseo del paciente de ser tratado y su estado clínico general, en particular su carga vírica en plasma y su recuento plasmático de linfocitos T CD4+, cuya determinación se debe hacer solamente con métodos que hayan sido aprobados y con un mismo método a lo largo de todo el seguimiento para garantizar la uniformidad de los resultados. El tratamiento debe tener por meta reducir, durante el mayor tiempo posible, la carga vírica plasmática por debajo del umbral de detección recomendado; restaurar y conservar la función inmunitaria; mejorar la calidad de la vida y reducir la mortalidad y morbilidad que suelen acompañar a la infección por VIH. Aquellos pacientes en quienes fracasa el régimen inicial deben ser sometidos a un cambio de r

  1. Nuevas recomendaciones para el tratamiento de personas con infección por VIH

    Directory of Open Access Journals (Sweden)

    2003-08-01

    Full Text Available Las recomendaciones más recientes del Departamento de Salud y Servicios Sociales de los Estados Unidos de América, que fueron emitidas en julio de 2003, tienen por finalidad facilitar la elección de un régimen de tratamiento para personas infectadas por el VIH, habida cuenta de la gran variedad de fármacos antirretrovírticos que han surgido en años recientes. Los fármacos que han mostrado mayor eficacia y que constituyen la base del tratamiento actual pertenecen a tres grandes grupos terapéuticos: los inhibidores nucleosídicos de la transcriptasa inversa, los inhibidores no nucleosídicos de la transcriptasa inversa y los inhibidores de las proteinasas. Son estos grupos, a su vez, los que integran los llamados regímenes conservadores de grupos terapéuticos, cuya finalidad es dejar de reserva para el futuro algunos grupos de fármacos por si se presenta resistencia a los utilizados inicialmente. El tratamiento de la infección por VIH con antirretrovíricos es complejo y difícil de cumplir, dado el elevado número de pastillas y de dosis diarias, y antes de iniciarse en pacientes asintomáticos es de rigor sopesar sus ventajas y beneficios. En la decisión es indispensable tener en cuenta el deseo del paciente de ser tratado y su estado clínico general, en particular su carga vírica en plasma y su recuento plasmático de linfocitos T CD4+, cuya determinación se debe hacer solamente con métodos que hayan sido aprobados y con un mismo método a lo largo de todo el seguimiento para garantizar la uniformidad de los resultados. El tratamiento debe tener por meta reducir, durante el mayor tiempo posible, la carga vírica plasmática por debajo del umbral de detección recomendado; restaurar y conservar la función inmunitaria; mejorar la calidad de la vida y reducir la mortalidad y morbilidad que suelen acompañar a la infección por VIH. Aquellos pacientes en quienes fracasa el régimen inicial deben ser sometidos a un cambio de r

  2. Concentrations in plasma clozapine levels in schizophrenic and schizoaffective patients.

    Science.gov (United States)

    Iglesias García, Celso; Iglesias Alonso, Ana; Bobes, Julio

    There is great variability in plasma levels of clozapine. The objective of this study is to know the characteristics of patients treated with clozapine and the relationship between them and the variability of plasma levels. Descriptive, cross-sectional study of all patients currently treated with clozapine in a Psychiatric Service with a diagnosis of schizophrenic psychosis or schizoaffective disorder. The present study assessed physical situation, psychopathology and functionality of the patients and explored the associations and correlations between clinical variables and plasma levels. We studied 39 patients, predominantly men, with negative and depressive symptoms and cardiovascular risk factors (metabolic syndrome and smoking). Significant variability in dose and even greater in clozapine levels were observed. The levels of clozapine at equal doses/kg of body weight were higher in non-smokers, they had positive correlation with BMI and negative correlation with systolic BP, disruptive behaviors and number of cigarettes consumed. Plasma level monitoring clozapine is an important tool to avoid clozapine plasma levels monitoring and minimize undesirable clinical situations (metabolic syndrome, sedation, negative symptoms and functional impairment). It is also important to control the effects of a smoking habit for optimum drug bioavailability. Copyright © 2017 SEP y SEPB. Publicado por Elsevier España, S.L.U. All rights reserved.

  3. Plasma rotation study in Tore Supra radio frequency heated plasmas

    International Nuclear Information System (INIS)

    Chouli, Bilal

    2014-01-01

    Toroidal flows are found to improve the performance of the magnetic confinement devices with increase of the plasma stability and confinement. In ITER or future reactors, the torque from NBI should be less important than in present-day tokamaks. Consequently, it is of interest to study other intrinsic mechanisms that can give rise to plasma rotation in order to predict the rotation profile in experiments. Intriguing observations of plasmas rotation have been made in radio frequency (RF) heated plasmas with little or no external momentum injection. Toroidal rotation in both the direction of the plasma current (co-current) and in the opposite direction (counter-current) has been observed depending on the heating schemes and plasma performance. In Tore Supra, most observations in L-mode plasmas have been in the counter-current direction. However, in this thesis, we show that in lower hybrid current drive (LHCD), the core toroidal rotation increment is in co- or counter-current direction depending on the plasma current amplitude. At low plasma current the rotation change is in the co-current direction while at high plasma current, the change is in the counter-current direction. In both low and high plasma current cases, rotation increments are found to increase linearly with the injected LH power. Several mechanisms in competition which can induce co- or counter-current rotation in Tore Supra LHCD plasmas are investigated and typical order of magnitude are discussed in this thesis. (author) [fr

  4. Filamentary magnetohydrodynamic plasmas

    International Nuclear Information System (INIS)

    Kinney, R.; Tajima, T.; McWilliams, J.C.; Petviashvili, N.

    1994-01-01

    A filamentary construct of magnetohydrodynamical plasma dynamics based on the Elsaesser variables is developed. This approach is modeled after discrete vortex models of hydrodynamical turbulence, which cannot be expected in general to produce results identical to those based on a Fourier decomposition of the fields. In a highly intermittent plasma, the induction force is small compared to the convective motion, and when this force is neglected, the plasma vortex system is described by a Hamiltonian. A statistical treatment of a collection of discrete current-vorticity concentrations is given. Canonical and microcanonical statistical calculations show that both the vorticity and the current spectra are peaked at long wavelengths, and the expected states revert to known hydrodynamical states as the magnetic field vanishes. These results differ from previous Fourier-based statistical theories, but it is found that when the filament calculation is expanded to include the inductive force, the results approach the Fourier equilibria in the low-temperature limit, and the previous Hamiltonian plasma vortex results in the high-temperature limit. Numerical simulations of a large number of filaments are carried out and support the theory. A three-dimensional vortex model is presented as well, which is also Hamiltonian when the inductive force is neglected. A statistical calculation in the canonical ensemble and numerical simulations show that a nonzero large-scale magnetic field is statistically favored, and that the preferred shape of this field is a long, thin tube of flux. Possible applications to a variety of physical phenomena are suggested

  5. Plasma physics and instabilities

    International Nuclear Information System (INIS)

    Lashmore-Davies, C.N.

    1981-01-01

    These lectures procide an introduction to the theory of plasmas and their instabilities. Starting from the Bogoliubov, Born, Green, Kirkwood, and Yvon (BBGKY) hierarchy of kinetic equations, the additional concept of self-consistent fields leads to the fundamental Vlasov equation and hence to the warm two-fluid model and the one-fluid MHD, or cold, model. The properties of small-amplitude waves in magnetized (and unmagnetized) plasmas, and the instabilities to which they give rise, are described in some detail, and a complete chapter is devoted to Landau damping. The linear theory of plasma instabilities is illustrated by the current-driven electrostatic kind, with descriptions of the Penrose criterion and the energy principle of ideal MHD. There is a brief account of the application of feedback control. The non-linear theory is represented by three examples: quasi-linear velocity-space instabilities, three-wave instabilities, and the stability of an arbitrarily largeamplitude wave in a plasma. (orig.)

  6. Plasma focus matching conditions

    International Nuclear Information System (INIS)

    Soliman, H.M.; Masoud, M.M.; Elkhalafawy, T.A.

    1988-01-01

    A snow-plough and slug models have been used to obtain the optimum matching conditions of the plasma in the focus. The dimensions of the plasma focus device are, inner electrode radius = 2 cm, outer electrode radius = 5.5 cm, and its length = 8 cm. It was found that the maximum magnetic energy of 12.26 kJ has to be delivered to plasma focus whose density is 10 19 /cm 3 at focusing time of 2.55 μs and with total external inductance of 24.2 n H. The same method is used to evaluate the optimum matching conditions for the previous coaxial discharge system which had inner electrode radius = 1.6 cm, outer electrode radius = 3.3 cm and its length = 31.5 cm. These conditions are charging voltage = 12 kV, capacity of the condenser bank = 430 μf, plasma focus density = 10 19 /cm 3 focusing time = 8 μs and total external inductance = 60.32 n H.3 fig., 2 tab

  7. Plasma deposition of refractories

    International Nuclear Information System (INIS)

    Kudinov, V.V.; Ivanov, V.M.

    1981-01-01

    The problems of deposition, testing and application of plasma coating of refractory metals and oxides are considered. The process fundamentals, various manufacturing procedures and equipment for their realization are described in detail. Coating materials are given (Al, Mg, Al 2 O 3 , ZrO 2 , MgAlO 4 ) which are used in reactor engineering and their designated purposes are shown [ru

  8. 5. Laser plasma interaction

    International Nuclear Information System (INIS)

    Labaune, C.; Fuchs, J.; Bandulet, H.

    2002-01-01

    Imprint elimination, smoothing and preheat control are considerable problems in inertial fusion and their possible solution can be achieved by using low-density porous materials as a buffer in target design. The articles gathered in this document present various aspects of the laser-plasma interaction, among which we have noticed: -) numerical algorithmic improvements of the Vlasov solver toward the simulation of the laser-plasma interaction are proposed, -) the dependence of radiation temperatures and X-ray conversion efficiencies of hohlraum on the target structures and laser irradiation conditions are investigated, -) a study of laser interaction with ultra low-density (0,5 - 20 mg/cm 3 ) porous media analyzing backscattered light at incident laser frequency ω 0 and its harmonics 3*ω 0 /2 and 2*ω 0 is presented, -) investigations of laser interaction with solid targets and crater formation are carried out with the objective to determine the ablation loading efficiency, -) a self organization in an intense laser-driven plasma and the measure of the relative degree of order of the states in an open system based on the S-theorem are investigated, and -) the existence and stability of electromagnetic solitons generated in a relativistic interaction of an intense laser light with uniform under-dense cold plasma are studied

  9. Fundamentals of plasma physics

    CERN Document Server

    Bittencourt, J A

    1986-01-01

    A general introduction designed to present a comprehensive, logical and unified treatment of the fundamentals of plasma physics based on statistical kinetic theory. Its clarity and completeness make it suitable for self-learning and self-paced courses. Problems are included.

  10. Plasma source ion implantation

    International Nuclear Information System (INIS)

    Conrad, J.R.; Forest, C.

    1986-01-01

    The authors' technique allows the ion implantation to be performed directly within the ion source at higher currents without ion beam extraction and transport. The potential benefits include greatly increased production rates (factors of 10-1000) and the ability to implant non-planar targets without rastering or shadowing. The technique eliminates the ion extractor grid set, beam raster equipment, drift space and target manipulator equipment. The target to be implanted is placed directly within the plasma source and is biased to a large negative potential so that plasma ions gain energy as they accelerate through the potential drop across the sheath that forms at the plasma boundary. Because the sheath surrounds the target on all sides, all surfaces of the target are implanted without the necessity to raster the beam or to rotate the target. The authors have succeeded in implanting nitrogen ions in a silicon target to the depths and concentrations required for surface treatment of materials like stainless steel and titanium alloys. They have performed ESCA measurements of the penetration depth profile of a silicon target that was biased to 30 kV in a nitrogen discharge plasma. Nitrogen ions were implanted to a depth of 700A at a peak concentration of 30% atomic. The measured profile is quite similar to a previously obtained profile in titanium targets with conventional techniques

  11. Plasma skin regeneration technology.

    Science.gov (United States)

    Bogle, M A

    2006-09-01

    Plasma skin regeneration (PSR) technology uses energy delivered from plasma rather than light or radiofrequency. Plasma is the fourth state of matter in which electrons are stripped from atoms to form an ionized gas. The plasma is emitted in a millisecond pulse to deliver energy to target tissue upon contact without reliance on skin chromophores. The technology can be used at varying energies for different depths of effect, from superficial epidermal sloughing to deeper dermal heating. With the Portrait PSR device (Rhytec, Inc.) there are three treatment guidelines termed PSR1, PSR2, and PSR3. The PSR1 protocol uses a series of low-energy treatments (1.0,1.2 Joules) spaced 3 weeks apart. The PSR2 protocol uses one high-energy pass (3.0, 4.0 Joules) performed in a single treatment, and the PSR3 protocol uses two high-energy passes (3.0 4.0 Joules) performed in a single treatment. All protocols improve fine lines, textural irregularities, and dyspigmentation; however, skin tightening is probably more pronounced with the high-energy treatments.

  12. Stirring Strongly Coupled Plasma

    CERN Document Server

    Fadafan, Kazem Bitaghsir; Rajagopal, Krishna; Wiedemann, Urs Achim

    2009-01-01

    We determine the energy it takes to move a test quark along a circle of radius L with angular frequency w through the strongly coupled plasma of N=4 supersymmetric Yang-Mills (SYM) theory. We find that for most values of L and w the energy deposited by stirring the plasma in this way is governed either by the drag force acting on a test quark moving through the plasma in a straight line with speed v=Lw or by the energy radiated by a quark in circular motion in the absence of any plasma, whichever is larger. There is a continuous crossover from the drag-dominated regime to the radiation-dominated regime. In the crossover regime we find evidence for significant destructive interference between energy loss due to drag and that due to radiation as if in vacuum. The rotating quark thus serves as a model system in which the relative strength of, and interplay between, two different mechanisms of parton energy loss is accessible via a controlled classical gravity calculation. We close by speculating on the implicati...

  13. Reprocessing of spent plasma

    International Nuclear Information System (INIS)

    Pierini, G.

    1981-01-01

    This invention relates to a process for removing helium and other impurities from a mixture containing deuterium and tritium, a deuterium/tritium mixture when purified in accordance with such a process and, more particularly, to a process for the reprocessing of spent plasma removed from a thermofusion reactor. (U.K.)

  14. Planetary plasmas and fields

    International Nuclear Information System (INIS)

    Roederer, J.G.

    1976-01-01

    The magnetospheres of earth, Jupiter, and Mercury are discussed. The main features and physical processes characteristic of the quiet time earth magnetosphere are examined. Jupiter's larger and more distant magnetosphere is compared with the earth's and recent findings are reviewed. The plasma and field environment of Mercury is also discussed and similarities with the earth's magnetosphere are noted

  15. Implicit plasma simulation

    International Nuclear Information System (INIS)

    Langdon, A.B.

    1985-01-01

    Implicit time integration methods have been used extensively in numerical modelling of slowly varying phenomena in systems that also support rapid variation. Examples include diffusion, hydrodynamics and reaction kinetics. This article discussed implementation of implicit time integration in plasma codes of the ''particle-in-cell'' family, and the benefits to be gained

  16. Fundamentals of Plasma Physics

    International Nuclear Information System (INIS)

    Cargill, P J

    2007-01-01

    The widespread importance of plasmas in many areas of contemporary physics makes good textbooks in the field that are both introductory and comprehensive invaluable. This new book by Paul Bellen from CalTech by and large meets these goals. It covers the traditional textbook topics such as particle orbits, the derivation of the MHD equations from Vlasov theory, cold and warm plasma waves, Landau damping, as well as in the later chapters less common subjects such as magnetic helicity, nonlinear processes and dusty plasmas. The book is clearly written, neatly presented, and each chapter has a number of exercises or problems at their end. The author has also thankfully steered clear of the pitfall of filling the book with his own research results. The preface notes that the book is designed to provide an introduction to plasma physics for final year undergraduate and post-graduate students. However, it is difficult to see many physics undergraduates now at UK universities getting to grips with much of the content since their mathematics is not of a high enough standard. Students in Applied Mathematics departments would certainly fare better. An additional problem for the beginner is that some of the chapters do not lead the reader gently into a subject, but begin with quite advanced concepts. Being a multi-disciplinary subject, beginners tend to find plasma physics quite hard enough even when done simply. For postgraduate students these criticisms fade away and this book provides an excellent introduction. More senior researchers should also enjoy the book, especially Chapters 11-17 where more advanced topics are discussed. I found myself continually comparing the book with my favourite text for many years, 'The Physics of Plasmas' by T J M Boyd and J J Sanderson, reissued by Cambridge University Press in 2003. Researchers would want both books on their shelves, both for the different ways basic plasma physics is covered, and the diversity of more advanced topics. For

  17. Plasma Wave Electronic Terahertz Technology

    National Research Council Canada - National Science Library

    Shur, Michael

    2003-01-01

    Plasma waves are oscillations of electron density in time and space. In deep submicron field effect transistors plasma wave frequencies lie in the terahertz range and can be tuned by applied gate bias...

  18. Probing of flowing electron plasmas

    International Nuclear Information System (INIS)

    Himura, H.; Nakashima, C.; Saito, H.; Yoshida, Z.

    2001-01-01

    Probing of streaming electron plasmas with finite temperature is studied. For the first time, a current-voltage characteristic of an electric probe is measured in electron plasmas. Due to the fast flow of the electron plasmas, the characteristic curve spreads out significantly and exhibits a long tail. This feature can be explained calculating the currents collected to the probe. In flowing electron plasmas, the distribution function observed in the laboratory frame is non-Maxwellian even if the plasmas come to a state of thermal equilibrium. Another significant feature of the characteristic is that it determines a floating potential where the current equals zero, despite there being very few ions in the electron plasma. A high impedance probe, which is popularly used to determine the space potential of electron plasmas, outputs the potential. The method is available only for plasmas with density much smaller than the Brillouin limit

  19. High-frequency plasma oscillations

    Energy Technology Data Exchange (ETDEWEB)

    Akhiezer, A I; Fainberg, Y B; Sitenko, A G; Stepanov, K; Kurilko, V; Gorbatenko, M; Kirochkin, U [Academy of Sciences of the Ukrainian SSR (USSR)

    1958-07-01

    It is well known that the electrical conductivity of a plasma, the ion-electron equilibration time, and the time required to heat the electron component of the plasma all increase greatly with increasing temperature. Consequently, the usual method of Joule heating a plasma may be difficult to apply in the region of high temperatures (> 10{sup 6}K), especially if the plasma current alone, without any additional measures, is used to generate magnetic fields for the confinement of the plasma. Therefore, it is of interest to study methods of plasma heating that do not directly use Joule heat, especially methods by which energy is directly supplied to the ion component during the time between collisions. Some of these methods make use of ionic resonance as well as other resonance phenomena which can occur in plasma in an external magnetic field. This paper deals with certain aspects of the theory of high-frequency plasma oscillations.

  20. Basic physics of colloidal plasmas

    Indian Academy of Sciences (India)

    Plasma Physics Division, Institute of Advanced Study in Science and Technology, Khanapara, ..... tic wave) to form a random collection of the nonlinear wave grains (like ... [8] M S Sodha and S Guha, in Advances in plasma phyiscs edited by A ...