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Sample records for contendo ions cromo

  1. USO DE PALHA DE AÇO COMERCIAL PARA O TRATAMENTO DE EFLUENTES CONTENDO CROMO HEXAVALENTE PROVENIENTES DE PROCESSOS DE ELETROCOLORAÇÃO DE AÇOS INOXIDÁVEIS

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    Kallyni Irikura

    Full Text Available Residual solutions containing Cr(VI ions can be harmful to the environment as well as to human health. Hence, practical and efficient methods for the treatment of such solutions are welcome. In this note, the treatment with commercial steel wool pads of a Cr(VI residual solution from electrochemical coloration processes of stainless steel is described in detail. Successful treatment was achieved when an amount of steel wool equivalent to 20% in excess in relation to the theoretical stoichiometric amount was used, followed by chemical precipitation with sodium hydroxide up to pH 10-11 and separation by filtration under reduced pressure. The treatment yielded a final solution with concentrations of Cr(III and Cr(VI ions of only 0.29 ± 0.02 mg L-1 and < 0.01 mg L-1, respectively. These concentration values are significantly lower than the maximum limits established by CONAMA for industrial wastewaters, attesting the efficiency of the treatment.

  2. Bioadsorción de iones de plomo y cromo procedentes de aguas residuales utilizando la cáscara de la mandarina (Citrus Reticuata Var. Clementina)

    OpenAIRE

    Verdugo Vergara, José Francisco

    2017-01-01

    El presente trabajo tiene el objetivo de evaluar la capacidad de bioadsorción de plomo y cromo mediante la cáscara de la mandarina, la cual es considerada un residuo, con esta investigación lo que se desea es aprovechar este residuo, empleándolo como bioadsorbente en el tratamiento de las aguas residuales contaminadas con metales pesados. En los procesos de bioadsorción se variaron algunos parámetros. The objective of this work assignment is to evaluate the bioadsorption capacity of lead a...

  3. The removal of toxic metals from liquid effluents by ion exchange resins. Part IV: Chromium(III)/H+ /Lewatit SP112; La eliminación de metales tóxicos presentes en efluentes líquidos mediante resinas de cambio iónico. Parte IV: cromo(III)/H+/Lewatit SP112

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    Alguacil, F.J.

    2017-09-01

    This investigation presented results on the removal of chromium(III), from aqueous solution in the 0-5 pH range, using Lewatit SP112 cationic exchange resin. Several aspects affecting the ion exchange process were evaluated, including: the influence of the stirring speed, temperature, pH of the solution, resin dosage and aqueous ionic strength. The selectivity of the system was tested against the presence of other metals in the aqueous solution, whereas the removal of chromium(III) from solutions was compared with results obtained using multiwalled carbon nanotubes as adsorbents. From the batch experimental data, best fit of the results is obtained with the Langmuir model, whereas the ion exchange process is best explained by the pseudo-second order model, moreover, experimental data responded well to the film-diffusion controlled model. Elution of the chromium(III) loaded into the resin is well accomplished by the use of sodium hydroxide solutions. [Spanish] En este trabajo se presentan los resultados obtenidos en la eliminación de cromo(III) de disoluciones acuosas (pH 0-5) mediante la resina de intercambio catiónico Lewatit SP112. Se han investigado algunas variables que pueden afectar al sistema: influencia de la agitación, temperatura, pH y fuerza iónica del medio acuoso y cantidad de resina; también se ha investigado acerca de la selectividad del sistema cuando otros metales están presentes en el medio acuoso, comparándose los resultados de la eliminación del cromo(III) usando la resina con los resultados obtenidos cuando se emplea otro adsorbente como son los nanotubos de carbono de pared múltiple. Los resultados experimentales indican que la carga del cromo(III) en la resina responde mejor al modelo de Langmuir, mientras que los modelos cinéticos indican que la carga del metal en la resina responde al modelo de pseudo-segundo orden y difusión en la capa límite. La elución del cromo(III) se realiza con disoluciones de hidróxid.

  4. Desempenho de um filme livre de cromo na proteção contra a corrosão de ligas de alumínio 2024.

    OpenAIRE

    Mayra Rúbia Silva Castro

    2001-01-01

    Este trabalho propõe o uso de um filme preparado a partir de solução aquosa alcalina contendo íons de lítio, borato e alumínio, no sentido de inibir a corrosão de ligas de alumínio de uso aeronáutico, buscando sempre comparações com filmes de sais de cromo, atualmente utilizados. Os filmes foram obtidos por dip coating (5 minutos) e por polarização anódica (5 e 45 minutos) de ligas de alumínio 2024-T3 na solução aquosa alcalina contendo íons de lítio, borato e alumínio. Foram feitas micrograf...

  5. Retention of chromium by modified Al-Bentonite Retenção de cromo por Al-bentonita modificada

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    C. Volzone

    2002-09-01

    Full Text Available Retention of chromium (III from a tanning wastewater by modified Al-bentonites was studied. One bentonite from San Juan province, Argentina, was used. Al-bentonite was prepared by contact of bentonite with hydrolyzed OH-Al solutions (0.10 M in Al for 24 hours. The modified Al-bentonites were obtained by: a treatment with 0.5 M sodium chloride; b with 0.5 M sodium chloride adjusted at pH 8; and c treatment with an hexametaphosphate solution after sodium addition. Then, the samples were dried at 100 °C and heated at 500 °C. The chromium (III retention by samples was carried out in batch system putting in contact the material with a 2000 ppm Cr tannery waste at different times. The retained chromium was characterized by analyzing the supernatant using UV-visible spectroscopy. The different chromium retention was correlated with structural characteristics of the solids.Foi estudada a retenção de cromo (III de águas residuais por meio de Al-bentonitas modificadas. Foi usada uma bentonita da província de San Juan, Argentina. As bentonitas-Al forma preparadas colocando-as em contato com soluções (0,10 M Al hydrolizadas de OH-Al durante 24 horas. As bentonitas-Al modidicadas foram obtidas por meio de: a tratamento com cloreto de sódio 0,5 M; b com cloreto de sódio 0,5 M sodium com pH ajustado para 8; e c tratamento com uma solução de hexametafosfato após a adição de sódio. As amostras foram então secas a 100 °C e aquecidas a 500 °C. A retenção do cromo (III pelas amostras foi feita em lotes colocando o material em contato em diferentes tempos com um resíduo contendo 2000 ppm de cromo. O cromo retido foi caracterizado por meio de análise do sobrenadante usando espectroscopia UV-visível. As diferentes retenções de cromo foram correlacionadas com características estruturais dos sólidos.

  6. ESTUDIO DE LA ADSORCION DE CROMO HEXAVALENTE COMO BIOMATERIAL LA ECTODERMIS DE OPUNTIA

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    Eduardo Campos Medina

    2008-01-01

    En este artículo se presenta el fenómeno de adsorción química como una opción viable en el tratamiento de aguas residuales que contiene disueltos iones metálicos, específicamente se aborda el estudio del Cromo Hexavalente, el cual se puso en contacto con el biomaterial de Ectodermis de Opuntia. Dicho biomaterial se puso en contacto con soluciones de dicho elemento solo y formando un complejo coloreado con la difenilcarbazida (DFC), esto con la finalidad de estudiar el comportamiento de la ads...

  7. con dietas suplementadas con Cromo-L-metionina

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    Ram\\u00F3n Garc\\u00EDa-Castillo

    2006-01-01

    Full Text Available Un total de 48 cerdos (Sus scrofa domesticus; 24 machos castrados y 24 hembras cruzados (Yorkshire, Hampshire, Duroc y Landrace de 3,5 a 4,0 meses de edad y 60,0 ± 5,0 kg PV en finalización. Se alimentaron con dietas isoproteícas (14,5 % PC e isoenergéticas (3.400 kcal EM/kg de MS, adicionadas con Cr-L-metionina (MiCroPlex® (0, 200, 400 y 600 ppb. El experimento tuvo una duración de 45 días y se realizó de agosto a noviembre del 2002 en las instalaciones de la Universidad Autónoma Agraria Antonio Narro, localizada en Saltillo, Coahuila, México. Al tener los animales aproximadamente 95 kg PV, se tomó muestra de 15 ml de sangre por cada animal para determinar la concentración de glucosa, ácido úrico, creatinina, urea, proteinas totales y colesterol. Se aplicó un diseño completamente al azar con arreglo factorial 2 x 4; dos para el factor sexo y cuatro para nivel de cromo. Los metabolitos en suero no fueron afectados (P>0,05 por el factor sexo. La glucosa en suero disminuyó (P<0,05 y el colesterol incrementó (P<0,05 con cromo en la dieta. Se concluye que el Cr incrementa el metabolismo de glucosa y disminuye el de colesterol, con lo cual puede haber energía disponible para síntesis de proteína la cual es necesaria para el crecimiento de los animales

  8. Avaliação da remoção de cromo (III por materiais compósitos porosos adsorventes de PE-g-MA, fibra de coco e quitosana, usando planejamento experimental

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    Dilma Alves Costa

    2017-04-01

    Full Text Available RESUMO Os processos de adsorção podem ser empregados no tratamento de efluentes líquidos contendo metais pesados visando a reduzir os danos ambientais. Porém, o alto custo dos materiais adsorventes justifica a aplicação de adsorventes alternativos, como a fibra de coco (FC e a quitosana (Q. Assim, este trabalho teve como objetivo desenvolver compósitos porosos adsorventes a partir da mistura de polietileno graftizado com anidrido maleico/FC/Q/NaCl, como agente porogênico (PE-g-MA/FC/Q/NaCl, e avaliar estatisticamente a capacidade de adsorção do cromo (III em solução, com auxílio do software Statistica 5.0®. Os resultados mostraram que a eficiência do processo sofreu influência das dimensões da FC, do teor de Q e do pH da solução contendo Cr (III. A capacidade máxima de remoção de Cr (III por unidade de massa do compósito foi de 42,28 mg.g-1.

  9. Profundidad del surco gingival en dientes primarios restaurados con coronas de acero cromo

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    Rubén Muñoz Delgado

    2015-01-01

    Full Text Available Objetivo: Evaluar la relación entre el ajuste marginal y la profundidad del surco gingival en dientes primarios restaurados con coronas de acero cromo. Métodos: Se midió la profundidad del surco gingival de 114 dientes primarios restaurados con coronas de acero cromo en 67 niños, ambos sexos, de 3 a 6 años de edad de la clínica de Estomatología Pediátrica de la UATx, México. La población en estudio fue dividida en tres grupos: a experimental (n=30, b control (n=8, y c control negativo (n=29. Previo consentimiento informado se tomaron los índices de placa (LöeSilness 1967 e índice gingival en seis superficies; se midió el surco gingival con sonda periodontal y las coronas de acero cromo fueron evaluadas clínica y radiográficamente según su ajuste marginal y longitud cervical. Resultados: Los índices de placa y gingival no mostraron diferencias significativas para los grupos experimental y control negativo. El 34% de las coronas mostraron buen ajuste marginal, 33% un mal ajuste, 10.5% cortas, 7.9% largas y el 14% otro tipo de mal ajuste. La profundidad del surco gingival fue estadísticamente significativa para el primer y segundo molar inferior derechos y en los caninos inferiores (p >0.05; la superficie disto-vestibular presentó la mayor profundidad del surco gingival (2.34 mm, siendo estadísticamente significativa (p>0.05. Conclusiones: La profundidad del surco gingival fue mayor en los dientes rehabilitados con coronas de acero cromo mal ajustadas y sobre contorneadas (largas. La presencia de placa bacteriana y gingivitis estuvo relacionada con las coronas de acero cromo mal ajustadas.

  10. Eliminación de cromo de efluentes ácidos, mediante adsorción con wollastonita natural

    OpenAIRE

    Martín Antonio Encinas Romero; Luis Alberto Núñez Rodríguez; Agustín Gómez Álvarez; Guillermo Del Carmen Tiburcio Munive

    2015-01-01

    El presente trabajo evalúa las características de la remoción de cromo con wollastonita natural a partir de soluciones sintéticas de cromo (VI) en medio ácido. Para realizar este estudio se desarrolló un diseño factorial 23 en el cual se estudiaron los factores: relación sólido/líquido, concentración de cromo en solución y temperatura. Se analizó el efecto de los factores principales y sus interacciones sobre el porcentaje de remoción de cromo mediante análisis gráficos. Asimismo, se desarr...

  11. Bacillus sp. G3 un microorganismo promisorio en la biorremediación de aguas industriales contaminadas con cromo hexavalente

    OpenAIRE

    Alexander Mora Collazos

    2016-01-01

    Introducción: El presente trabajo tuvo como objetivo identificar y caracterizar microorganismos provenientes de un agua residual industrial potencialmente útiles en biorremediación de aguas contaminadas con cromo hexavalente. Metodología: Se realizó el aislamiento de tres microorganismos partiendo de un agua residual industrial proveniente de una empresa de galvanoplastia. Se evaluó el potencial de los microorganismos aislados en su capacidad para reducir cromo hexavalente; escogiéndose al ai...

  12. Estudio de la biosorción de cromo con hoja de café

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    Luis Carlos Florez García

    2009-05-01

    Full Text Available El objeto de este trabajo es proveer una alternativa para la remoción de metales pesados como el cromo de las aguas residua- les (efluentes de la industria del cuero y de electrorrecubrimientos de piezas metálicas (galvanoplastia, utilizando como bioma- sa hojas de café. A condiciones de operación de pH de la disolución de 4, grado de agitación 0 rpm, tamaño de partícula de la biomasa de 0,149 mm de diámetro y relación masa de biomasa / volumen de disolución de 0,85 gr/ml, se obtuvieron eficien- cias en la remoción de cromo, con la hoja de café variedad castillo, coffee arabica del 82% para disoluciones sintéticas de1.000 mg/L.

  13. Alteraciones cromosómicas diagnosticadas en sangre periférica

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    Irenia Blanco Pérez

    2013-12-01

    Full Text Available Introducción: el estudio citogenético en linfocitos de sangre periférica es un medio diagnóstico muy solicitado por diferentes especialidades médicas, es utilizado ampliamente para diagnosticar diferentes cromosomopatías de origen genético. Objetivo: describir las principales alteraciones cromosómicas diagnosticadas en sangre periférica en la Provincia de Pinar del Río a partir de enero del año 2007 hasta diciembre del 2011. Material y método: se efectuó un estudio descriptivo de tipo retrospectivo en 831 pacientes que fueron remitidos al Centro Provincial de Genética Médica. La muestra la conformaron 117 pacientes que resultaron positivos al mostrar en su cariotipo hallazgos de cromosomopatías. Se analizaron: el motivo de indicación, la cantidad de diagnósticos realizados, los tipos de anomalías detectadas. Resultados: en el período estudiado se detectaron 68 casos positivos, el orden de frecuencia de las anomalías cromosómicas fue: las aberraciones estructurales (60.6 %, aberraciones numéricas (34.1 % y mosaicos (5.1 %. Las principales alteraciones correspondieron a trisomías, translocaciones y polimorfismos cromosómicos, sobre todo del cromosoma 9. Conclusiones: los resultados de este estudio se comportan de manera similar con los reportados en la bibliografía revisada y confirma la alta prevalencia de alteraciones cromosómicas en la población de Pinar del Río, donde cabe destacar, la importancia del estudio citogenético en sangre periférica a las personas con antecedentes de abortos espontáneos, infertilidad, dismórfias, reordenamientos cromosómicos balanceados, entre otros, con el fin de establecer un diagnóstico certero, oportuno y proporcionar un buen asesoramiento genético.

  14. Refractory oxides containing aluminium and barium Oxidos refratários contendo alumínio e bário

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    T. J. Davies

    1998-10-01

    Full Text Available Oxides containing aluminium and barium, optionally with chromium, are refractory with several possible industrial uses. A gel precursor of an oxide having the formula BaO.n(Al2xCr2yO3, where 1Oxidos contendo alumínio e bário, opcionalmente com crômio, são refratários com vários possíveis usos industriais. Foi preparado um gel precursor de um óxido de formula BaO.n(Al2xCr2yO3, com 1cromo III, formando então um gel que é queimado para se obter o óxido desejado. Filamentos podem ser estraídos duramente a formação do gel ou extrudados de um gel semi-rígido. Estudos de infravermelho com transformada de Fourier, difração de raios X e ressonância magnética nuclear com 27AL mostraram que o bário não é incorporado diretamente na estrutura do gel. Oxidos de alumínio e bário foram obtidos somente após liquefação de espécies de bário. Foi preparada uma mistura de pós adequada para queima para se obter um óxido de fórmula BaO.m[Al2x Cr2y O3] com 4,6cromo III, com quantidades relativas variando para se obter na queima valores desejados de m e de y. Corpos cerâmicos resistentes da fórmula BaO 6 Al2O3 (m=6 e y=0 foram preparados. Estudos de difração de raios X de óxidos de composições (n ou m=6 e y=0 sinterizados em alta temperatura mostraram que mono-aluminato de bário é uma fase intermediária de baixa temperatura. Cromo III reduz a temperatura necessária para formar um óxido de alumínio e bário. É feito um sumário de trabalhos anteriormente publicados.

  15. Bacillus sp. G3 un microorganismo promisorio en la biorremediación de aguas industriales contaminadas con cromo hexavalente

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    Alexander Mora Collazos

    2016-01-01

    Full Text Available Introducción: El presente trabajo tuvo como objetivo identificar y caracterizar microorganismos provenientes de un agua residual industrial potencialmente útiles en biorremediación de aguas contaminadas con cromo hexavalente. Metodología: Se realizó el aislamiento de tres microorganismos partiendo de un agua residual industrial proveniente de una empresa de galvanoplastia. Se evaluó el potencial de los microorganismos aislados en su capacidad para reducir cromo hexavalente; escogiéndose al aislado bacteriano G3 por mostrase potencialmente útiles en biorremediación de cromo hexavalente. Se realizó la caracterización morfológica, bioquímica e inferencias filogenéticas basadas en el gen del ARNr 16S del aislado seleccionado; se evaluó el potencial de reducción de cromo hexavalente asociado a la actividad microbiana y la actividad enzimática utilizando un extracto libre de células; de forma adicional, se realizaron bioensayos de reducción de cromo evaluando la acción conjunta de los 3 microorganismos. Resultados: Los datos moleculares y pruebas bioquímicas sugieren que el asilado bacteriano G3 pertenece al grupo de Bacillus cereus sensu lato. Los bioensayos de reducción de cromo hexavalente (10 mg/L realizados con Bacillus sp. G3 mostraron una reducción química del 100% del contaminante al cabo de diez horas en medio LB y de 34 horas en agua residual industrial. El extracto libre de células obtenido a partir del aislado bacteriano G3 mostró actividad de cromato reductasa al reducir el cromo hexavalente a su forma trivalente, mostrando valores óptimos de actividad relativa a 28ºC y 6.5 de pH. La acción conjunta de los microorganismos sobre la reducción de cromo se mostró cinco veces menos eficiente que los ensayos realizados solo con la cepa G3. Discusión o conclusión: Los resultados sugieren, que el aislado bacteriano G3 se muestra como un microorganismo con buen potencial para utilizarse en procesos de biorremediaci

  16. Eliminación de cromo de efluentes ácidos, mediante adsorción con wollastonita natural

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    Martín Antonio Encinas Romero

    2015-05-01

    Full Text Available El presente trabajo evalúa las características de la remoción de cromo con wollastonita natural a partir de soluciones sintéticas de cromo (VI en medio ácido. Para realizar este estudio se desarrolló un diseño factorial 23 en el cual se estudiaron los factores: relación sólido/líquido, concentración de cromo en solución y temperatura. Se analizó el efecto de los factores principales y sus interacciones sobre el porcentaje de remoción de cromo mediante análisis gráficos. Asimismo, se desarrolló una ecuación de predicción del porcentaje de remoción de cromo en función de los efectos principales e interacciones más significativas, obteniendo correlaciones satisfactorias entre la información experimental y la predicha por la ecuación.

  17. Evaluación de cromo en ambientes de trabajo en una industria de curtiembres y una de galvanoplastia

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    Sonia Agudelo C.

    2010-07-01

    Full Text Available Fueron determinados los contenidos de cromo hexavalente y cromo total soluble en muestras de aire, para una industria de curtiembres y una de galvanoplastia, ubicadas en Santafé de Bogotá, con el fin de evaluar el riesgo por exposición ocupacional a estas especies. Las muestras fueron recolectadas por medio de bombas de succión, colocadas en la zona de respiración de los trabajadores, utilizando como elemento de captación filtros de membrana de cloruro de polivinilo PVC. Fue utilizado como sistema de muestreo el método de período parcial con muestras consecutivas. La especie Cr(VI fue determinada por colorimetría y cromo total soluble por espectrofotometría de absorción atómica con llama, previa optimización de los métodos. Para la industria de curtiembres los contenidos de Cr(VI oscilan entre no detectables y 9.4pg/m^ de aire y cromo total soluble entre no detectable y 74.0pg/m\\ Para la industria de galvanoplastia fueron encontrados contenidos de Cr(VI entre no detectable y 140pg/m' y cromo total soluble entre no detectable y 500pg/m'. Para las dos industrias estudiadas se superan los niveles permitidos durante varios muéstreos.

  18. Comparação das reservas glicogênicas em ratos jovens e envelhecidos tratados com picolinato de cromo

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    Rodrigues, Marcella Damas; Borin, Sérgio Henrique; Paulino, Patrícia Carla; Arruda, Eder João; Silva, Carlos Alberto da

    2014-01-01

    INTRODUÇÃO: Entre os suplementos utilizados no meio esportivo, o mineral cromo tem se destacado, principalmente por potencializar a ação da via insulínica, ação extremamente importante na manutenção da homeostasia metabólica. A ação do cromo parece ter ação importante como coadjuvante nas dinâmicas da ação insulínica.OBJETIVO: Avaliar o perfil glicogênico, bem como a sensibilidade tecidual à insulina e a pancreática à glicose em ratos jovens e envelhecidos tratados com picolinato de cromo.MÉT...

  19. ADSORCIÓN DE CROMO HEXAVALENTE EN LA CÁSCARA DE ARROZ MODIFICADA QUÍMICAMENTE

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    Nancy Eggs; Susana Salvarezza; Ricardo Azario; Nicolás Fernández; María del C. García

    2012-01-01

    El objetivo del presente estudio fue analizar los factores cinéticos que afectan la adsorción de cromo (VI) en solución empleando como bioadsorbente la cáscara de arroz modificada químicamente, con hidróxido de potasio 1% m/m o con ácido fosfórico 1M. Se estudió la adsorción de cromo (VI) considerando los siguientes parámetros pH, tiempo de incubación, masa del bioadsorbente y concentración inicial del tóxico. La determinación de cromo hexavalente y total se realizó por el método de la difeni...

  20. Caracterización y recuperación de sales de cromo hexavalente de un pasivo ambiental

    OpenAIRE

    Rangel Cordova, Agustín Alexander; Isarain Chávez, Eloy; Maldonado Vega, María

    2015-01-01

    La presente investigación exploró diferentes soluciones de lavado con la finalidad de llevar a cabo la recuperación de cromo hexavalente a partir de un residuo industrial regulado por la NOM-147-SEMARNAT/SSA1-2004. El tratamiento consistió en un muestreo aleatorio simple así como su caracterización fisicoquímica, teniendo como base la alta solubilidad de la especie hexavalente de cromo. Posterior a ello se realizaron una serie de lavados utilizando cinco diferentes disoluciones (agua, ácido s...

  1. Reducción de cromo hexavalente en cementos usando sulfato ferroso mono y heptahidratado: eficacia y almacenabilidad

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    Valverde, J. L.; Lobato, J.; Fernández, I.; Marijuán, L.; Pérez-Mohedano, S.; Talero, R.

    2005-01-01

    [ES] Las sustancias que contienen cromo hexavalente están clasificadas en la legislación comunitaria como sustancias carcinogénicas, mutagénicas y sensibilizantes. El cromo hexavalente del cemento potencia la sensibilización y provoca graves reacciones alérgicas que sufren bastante a menudo los trabajadores que lo manipulan habitualmente, ya sea en fábrica o en el sector de la construcción. La dermatitis alérgica o de contacto que produce es muy dolorosa y puede dejar a los trabajadores en es...

  2. Fosfato de cromo (III marcado con diferentes radionúclidos para uso en radiosinoviortesis

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    Jorge Cruz Arencibia

    2012-06-01

    Full Text Available Introducción: la radiosinoviortesis se utiliza en el tratamiento de la sinovitis crónica, complicación frecuente en enfermedades sistémicas como artritis reumatoide y hemofilia. En la práctica clínica internacional se emplean diferentes coloides y suspensiones radiactivas, pero su número es reducido y su disponibilidad limitada. Objetivo: obtención y caracterización físico-química de suspensiones de fosfato de cromo (III marcadas con radionúclidos como potenciales radiofármacos para uso en radiosinoviortesis. Métodos: las suspensiones se obtuvieron por síntesis química, los radionúclidos se añadieron al inicio de la reacción o después de finalizada esta. El tamaño de partículas se estimó mediante microscopia óptica y filtración por membranas. Asimismo se evaluó por espectrofotometría la estabilidad de la suspensión al ser resuspendida en distintos medios. La pureza radioquímica se determinó por cromatografía de papel. Resultados: se obtuvo y caracterizó una suspensión de fosfato de cromo (III. El producto obtenido presentó un tamaño de partículas predominante entre 0,8-5 µm y que al ser suspendidas en solución de gelatina al 2 % en tampón acetato 1 mg/mL no sedimentó en menos de 3 h. Se estableció la tecnología para la obtención de formulaciones de fosfato de cromo (III marcado con 32P e 90Y y se demostró la factibilidad de marcar la suspensión obtenida con otros radionúclidos trivalentes como 177Lu y 68Ga. Conclusiones: los resultados permiten considerar al fosfato de cromo (III una suspensión base para la obtención de radiofármacos para uso en radiosinoviortesis en diferentes articulaciones, en función de las características físico-nucleares de los radionúclidos que se empleen.

  3. Efecto in vitro del cromo (VI) sobre un biomarcador tumoral p53 y daño al ADN en hepatocitos murinos

    OpenAIRE

    Delgado Sarmiento, Pavel; Vera Gonzales, Corina; Arenas Chávez, Carlos

    2013-01-01

    El cromo es un metal pesado de uso múltiple en las diferentes especialidades que abarca la ciencia y tecnología en el mundo. Sin embargo, el cromo (VI) provoca daños en el ser humano por ingestión en dosis concentradas; produciendo anomalías en diferentes tipos de células; lo cual ha sido reportado por el Organismo Panamericano de Salud y Organismo Mundial de la Salud. En el presente trabajo se plantea el estudio de los efectos del cromo (VI) in vitro en hepatocitos murinos, los cuales fueron...

  4. Diseño de un biofiltro para reducir el índice de contaminación por cromo generado en las industrias del curtido de cueros

    OpenAIRE

    HIGUERA COBOS, OSCAR FABIÁN; ARROYAVE LONDOÑO, JUAN FELIPE; FLOREZ GARCIA, LUIS CARLOS

    2010-01-01

    El sector industrial de las curtiembres genera descargas con volúmenes altos de concentrados de cromo. El cromo es usado en esta industria como agente de curtido. La dificultad que presenta el uso de sales de cromo en el curtido de pieles, se debe a la gran cantidad de curtiente que no se fija y finalmente se descarga al ambiente, en las aguas residuales causando efectos negativos en el ambiente y a la salud humana. El objeto de este trabajo es proveer una alternativa para la remoción de crom...

  5. DISEÑO DE UN BIOFILTRO PARA REDUCIR EL ÍNDICE DE CONTAMINACIÓN POR CROMO GENERADO EN LAS INDUSTRIAS DEL CURTIDO DE CUEROS

    OpenAIRE

    OSCAR FABIÁN HIGUERA COBOS; JUAN FELIPE ARROYAVE LONDOÑO; LUIS CARLOS FLOREZ GARCIA

    2009-01-01

    El sector industrial de las curtiembres genera descargas con volúmenes altos de concentrados de cromo. El cromo es usado en esta industria como agente de curtido. La dificultad que presenta el uso de sales de cromo en el curtido de pieles, se debe a la gran cantidad de curtiente que no se fija y finalmente se descarga al ambiente, en las aguas residuales causando efectos negativos en el ambiente y a la salud humana. El objeto de este trabajo es proveer una alternativa para la remoción de crom...

  6. ADSORCIÓN DE CROMO HEXAVALENTE EN LA CÁSCARA DE ARROZ MODIFICADA QUÍMICAMENTE

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    Nancy Eggs

    2012-01-01

    Full Text Available El objetivo del presente estudio fue analizar los factores cinéticos que afectan la adsorción de cromo (VI en solución empleando como bioadsorbente la cáscara de arroz modificada químicamente, con hidróxido de potasio 1% m/m o con ácido fosfórico 1M. Se estudió la adsorción de cromo (VI considerando los siguientes parámetros pH, tiempo de incubación, masa del bioadsorbente y concentración inicial del tóxico. La determinación de cromo hexavalente y total se realizó por el método de la difenilcarbazida y por espectrofotometría de absorción atómica, respectivamente. El tratamiento químico con hidróxido de potasio o con ácido fosfórico de la cáscara de arroz produjo un aumento en la adsorción del tóxico. El análisis cinético de la adsorción de cromo (VI sugiere que el proceso es favorable cuando se trabaja a pH ácido (inferior a 2, se incrementa con la masa de bioadsorbente y con el tiempo de contacto.

  7. Empleo de microalga Scenedesmus obliquas en la eliminación de cromo presente en aguas residuales galvánicas

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    Pellón, A.

    2003-02-01

    Full Text Available Dumping wastewaters from plating industry with a high content in chromium is a potential hazard for people and environment. It is known that some metals, including the heavy metals, at low concentrations participate in different metabolic routes, but at high concentration are toxic for many living organisms. Some microorganism taking the heavy metals from the environment are capable of concentrating and accumulating large quantities of them in different citoplasmatic structures with no-toxic effects. Microalgae have affinity by the polyvalent metals making possible their use as depollutant agent in waters that contains dissolved metallic ions as alternative methods when others methods of recycle are unusable. In this report a chromium removal study from a plating wastewater, using scenedesmus obliquus culture was made. The removal efficiency of Cr (VI was 12 % and Cr (III was 27 % and for condition of algae's immobilization removal of Cr (III was 95 %.

    El vertido de aguas residuales con alto contenido de cromo, procedentes de las industrias galvanoplásticas, es un peligro potencial que se le presenta a la población y al medio ambiente. Se conoce que algunos metales, incluyendo los pesados, a concentraciones bajas participan en diferentes rutas metabólicas, pero en altas concentraciones pueden ser tóxicos para muchos organismos vivos. Algunos microorganismos toman los metales pesados del medio ambiente, siendo capaces de concentrar y acumular grandes cantidades de los mismos en diferentes estructuras citoplasmáticas, sin que lleguen a ocasionar efectos tóxicos en los mismos. Las microalgas son un ejemplo de este comportamiento, ya que tienen afinidad por los metales polivalentes, de ahí la posibilidad de su aplicación como agentes descontaminantes en aguas que contengan iones metálicos disueltos como método alternativo cuando no se pueda utilizar otro método de recuperación. En este trabajo se realizó un estudio de

  8. O uso do picolinato de cromo como coadjuvante no tratamento da diabetes mellitus - doi: 10.5102/ucs.v3i2.558

    OpenAIRE

    Marangon, Antônio Felipe Corrêa; Fernandes, Luis Gabriel de Melo

    2008-01-01

    O cromo é elemento essencial requerido para o metabolismo normal de carboidratos e lipídeos. A deficiência de cromo em humanos e outros mamíferos tem resultado em sintomas comparado àqueles associados ao início de diabetes, como elevação da glicose sangüínea, insulina, colesterol e triglicerídeos, e diminuição das lipoproteínas de alta densidade (HDL). A resposta ao cromo está relacionada ao grau de intolerância à glicose. Tem sido demonstrado que o cromo é efetivo no tratamento dos vár...

  9. O uso do picolinato de cromo como coadjuvante no tratamento da diabetes mellitus - doi: 10.5102/ucs.v3i2.558

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    Antônio Felipe Corrêa Marangon

    2008-04-01

    Full Text Available O cromo é elemento essencial requerido para o metabolismo normal de carboidratos e lipídeos. A deficiência de cromo em humanos e outros mamíferos tem resultado em sintomas comparado àqueles associados ao início de diabetes, como elevação da glicose sangüínea, insulina, colesterol e triglicerídeos, e diminuição das lipoproteínas de alta densidade (HDL. A resposta ao cromo está relacionada ao grau de intolerância à glicose. Tem sido demonstrado que o cromo é efetivo no tratamento dos vários tipos de diabetes e é considerado um dos nutrientes menos tóxicos.

  10. DISEÑO DE UN BIOFILTRO PARA REDUCIR EL ÍNDICE DE CONTAMINACIÓN POR CROMO GENERADO EN LAS INDUSTRIAS DEL CURTIDO DE CUEROS

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    OSCAR FABIÁN HIGUERA COBOS

    2009-01-01

    Full Text Available El sector industrial de las curtiembres genera descargas con volúmenes altos de concentrados de cromo. El cromo es usado en esta industria como agente de curtido. La dificultad que presenta el uso de sales de cromo en el curtido de pieles, se debe a la gran cantidad de curtiente que no se fija y finalmente se descarga al ambiente, en las aguas residuales causando efectos negativos en el ambiente y a la salud humana. El objeto de este trabajo es proveer una alternativa para la remoción de cromo de aguas residuales de curtiembre utilizando la biomasa de hoja de café variedad castillo, coffea arabica.

  11. Cuantificación de plomo, cadmio y cromo mediante sialoquímica

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    GONZÁLEZ MIREYA

    1997-01-01

    Full Text Available Objetivo. Determinar las concentraciones de plomo, cadmio y cromo, y establecer su posible asociación con diferentes factores sociodemográficos. Material y métodos. Se seleccionó una muestra representativa de 100 estudiantes de posgrado de la Facultad de Odontología de la Universidad Nacional Autónoma de México (UNAM, a los cuales se les colectó saliva total no estimulada. Dichas muestras fueron analizadas por espectrofotometría de absorción atómica con horno de grafito. Resultados. Metales pesados como el plomo, el cadmio y el cromo se encuentran en concentraciones mucho más altas que las informadas en la literatura: Pb, = 3.10 m g/dL-1, máxima: 16.8 my g/dL-1, y mínima: 0.04 my g/dL-1; Cd, = 0.25 my g/dL-1, máxima: 2.04 my g/dL-1, y mínima: 0.004 my g/dL-1; y Cr, = 1.43 my g/dL-1, máxima: 4.82 my g/dL-1, y mínima: 0.05 my g/dL-1. Asimismo, variables como la zona de residencia, el sexo, la edad y la ingesta de comida enlatada no influyen en los niveles de plomo y cromo. Sin embargo, en el caso del cadmio y la edad existe una asociación inversa (ji²= 5.9012, p<= 0.05; gamma = -0.5224, p<= 0.05. Conclusiones. La sialoquímica juega un papel importante en la detección de contaminantes, fármacos, drogas y enfermedades locales y sistémicas. La contaminación por metales pesados sigue siendo un problema de salud pública, por lo que el gobierno debe consolidar un programa cuyo objetivo sea eliminar los diferentes contaminantes del ambiente. Asimismo, se deben realizar otros estudios para verificar la asociación de variables como sexo, edad, uso de cerámica vidriada, alimentación y zona de residencia con las concentraciones de metales pesados en saliva.

  12. REMOCION DE CROMO Y MATERIA ORGANICA DISUELTA EN EFLUENTES INDUSTRIALES POR ADSORCIÓN E INTERCAMBIO IONICO EN ZEOLITA Y CARBON ACTIVADO.

    OpenAIRE

    COVARRUBIAS GALLARDO, CRISTIAN MAURICIO; COVARRUBIAS GALLARDO, CRISTIAN MAURICIO

    2005-01-01

    Se estudió la remoción de cromo y materia orgánica desde solución acuosa utilizando métodos de separación basados en el uso de zeolitas y carbón activado. Para este propósito se evaluó la operación de remoción de cromo en columnas empacadas de zeolita y c 175p.

  13. Avaliação da estabilidade de xaropes contendo aminas aromáticas

    OpenAIRE

    Beatriz Resende Freitas

    2002-01-01

    Atualmente a grande malona dos fármacos apresenta grupamento amínico. Estes quando associados à açúcares redutores ou a outros adjuvantes farmacêuticos contendo carbonila, freqüentemente produzem manchas de escurecimento ou descoloração, a Reação de Maillard pode explicar tal ocorrência. Além de poder comprometer a idoneidade do produto. O presente trabalho tem como objetivo estudar o comportamento de xaropes contendo aminas aromáticas, tendo em vista que a associação entre açúcares e aminas ...

  14. Baixa dosagem de óxido de cromo para estimativa da produção fecal em bovinos Low level of chromium oxide to estimate faecal output in cattle

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    Henrique Mendonça Nunes Ribeiro Filho

    2008-12-01

    Full Text Available Foi avaliado o uso de baixa dosagem de óxido de cromo (Cr2O3 incorporado em um alimento concentrado para estimativa da produção fecal (PF em bovinos. Para tanto, foram conduzidos quatro ensaios de digestibilidade in vivo utilizando quatro novilhos com peso vivo médio de 214±31kg, recebendo ad libitum no cocho azevém anual (Lolium multiflorum Lam. cortado verde. Aproximadamente 200g de ração contendo 5g kg-1 do indicador foi fornecida diariamente durante 12 dias, sendo feito a coleta de dados e amostras nos últimos cinco dias de cada período. A PF foi medida com o uso de sacolas de coleção total ou estimada com base na concentração do indicador em amostras fecais coletadas duas vezes ao dia (8 e 16h ou a intervalos de duas horas entre 8 e 22h. A concentração média de cromo nas amostras coletadas às 8 e 16h (445mg kg-1 foi semelhante à média geral de todos os horários (447mg kg-1. O grau de recuperação fecal (GR do indicador aumentou linearmente, de aproximadamente 40% para em torno de 80%, com o aumento da concentração fecal de cromo até esta última atingir um valor em torno de 250mg kg-1 de MO. Quando a concentração de cromo nas fezes foi superior a este valor o GR se manteve relativamente constante, em média 76%. A produção fecal foi superestimada pelo indicador em até 35% quando não corrigido para o GR. Quando corrigido para a recuperação fecal, as estimativas de produção fecal de MO estimadas foram similares às observadas. A excreção fecal de bovinos alimentados com azevém pode ser acuradamente estimada com o uso de baixa dosagem de óxido de cromo incorporado em uma ração peletizada concomitante à coleta de duas amostragens diárias de fezes.The aim of this research was to evaluate the use of a low level of chromium oxide (Cr2O3 incorporated into the concentrate ration to estimate faecal output (FO in cattle. Four in vivo digestibility essays were conducted using four steers with live weights of

  15. Comparação das reservas glicogênicas em ratos jovens e envelhecidos tratados com picolinato de cromo

    OpenAIRE

    Rodrigues,Marcella Damas; Borin,Sérgio Henrique; Paulino,Patrícia Carla; Arruda,Eder João; Silva,Carlos Alberto da

    2014-01-01

    INTRODUÇÃO: Entre os suplementos utilizados no meio esportivo, o mineral cromo tem se destacado, principalmente por potencializar a ação da via insulínica, ação extremamente importante na manutenção da homeostasia metabólica. A ação do cromo parece ter ação importante como coadjuvante nas dinâmicas da ação insulínica. OBJETIVO: Avaliar o perfil glicogênico, bem como a sensibilidade tecidual à insulina e a pancreática à glicose em ratos jovens e envelhecidos tratados com picolinato de cro...

  16. Contaminación por cromo en Noreste de la Ciudad de México, un enfoque Interdisciplinario

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    Margarita Eugenia Gutiérrez R.

    1986-01-01

    Full Text Available En el municipio de Tultitlán, Edo.de México, se acumularon residuos industriales con un alto contenido de cromo en formas químicas muy solubles, por lo que el elemento se está dispersando en el entorno. Principalmente se infiltra y contamina aguas subterráneas, pero en menor medida también está afectando la atmósfera y los suelos. En este artículo se describen los niveles de cromo en aguas profundas y suelos; los antecedentes y las causas que provocaron el problema, las características del medio, una primera estimación del área afectada; y, finalmente, se plantean posibles soluciones.

  17. USO DE CENIZA VOLANTE EN LA REMOCIÓN DE CROMO (III DE LOS EFLUENTES LÍQUIDOS DE CURTIEMBRES

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    Edison Gil Pavas

    2010-10-01

    Full Text Available El presente estudio describe un método simple y económico para la remoción de cromo (III de efluentes líquidos de la industria de curtiembres utilizando ceniza volante. El proceso se llevó a cabo en forma discontinua utilizando como variables la masa de ceniza volante, el tiempo de contacto y la temperatura o el pH, Con estas variables se realizó un diseño de experimentos tipo Box-Wilson, el cual se optimizó posteriormente empleando un programa estadístico. Se utilizó una ceniza volante original y otra sometida a un tratamiento químico. Los resultados mostraron la posibilidad de bajar concentración inicial de cromo de 1850 ppm a una final de 0,008 ppm, cumpliendo así con las exigencias ambientales sobre este agente contaminante.

  18. Recuperación del cromo y aluminio del licor de desecho (wl en forma de sales dobles

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    Pedro R. Bassas-Noa

    2006-03-01

    Full Text Available El licor WL es un residual de la industria del níquel agresivo al medio ambiente por su acidez que contiene elementos metálicos de gran valor. Se propone un tratamiento para la separación con  hidróxido de amonio y la recuperación de la mayor cantidad de cromo y aluminio contenidos en el mismo. Se logra precipitar una mezcla de hidróxidos de aluminio que tratada con ácido sulfúrico permite obtener, por cristalización, la sal sulfato de aluminio y amonio dodecahidratada. Posteriomente se cristaliza la sal sulfato doble de cromo y amonio dodecahidratado. Se demuestra que el sulfato doble de cromo y amonio dodecahidratado y el sólido separado presentan características químicas que hacen posible su aplicación en la industria textil y de cerámica, entre otras. El esquema aplicado permite la recuperación de valores metálicos y la disminución del alto poder contaminante del licor de desecho WL.

  19. Comparação das reservas glicogênicas em ratos jovens e envelhecidos tratados com picolinato de cromo

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    Marcella Damas Rodrigues

    2014-10-01

    Full Text Available INTRODUÇÃO: Entre os suplementos utilizados no meio esportivo, o mineral cromo tem se destacado, principalmente por potencializar a ação da via insulínica, ação extremamente importante na manutenção da homeostasia metabólica. A ação do cromo parece ter ação importante como coadjuvante nas dinâmicas da ação insulínica. OBJETIVO: Avaliar o perfil glicogênico, bem como a sensibilidade tecidual à insulina e a pancreática à glicose em ratos jovens e envelhecidos tratados com picolinato de cromo. MÉTODO: Foram utilizados ratos Wistar, com idade de 3 e 24 meses, distribuídos em quatro grupos experimentais (n = 6, assim denominados: jovens (J, jovens suplementados com picolinato de cromo (JP, 80 µg/Kg, envelhecidos (E e envelhecidos suplementados com picolinato de cromo (EP, 80 µg/Kg. A sensibilidade à insulina foi avaliada através do teste de tolerância à insulina (ITT, 2 U/Kg e a sensibilidade pancreática, através do teste de tolerância à glicose (GTT, 2 g/Kg. Na análise estatística foi utilizado teste de normalidade de dados de Kolmogorov-Smirnov, seguido de ANOVA e o teste post-hoc de Tukey, p < 0,05. RESULTADOS: O grupo envelhecido apresentou menores reservas glicogênicas se comparado ao grupo jovem; por sua vez, o tratamento com picolinato promoveu elevação das reservas hepáticas de ratos jovens sem efeito nos envelhecidos. No mesmo perfil de análise, foi demonstrado que o tratamento com picolinato promoveu elevação das reservas glicogênicas musculares, efeito observado tanto nos jovens quanto nos envelhecidos. No grupo jovem, não foi observada diferença no ITT, porém houve redução da área sob a curva descrita no GTT. No grupo envelhecido, houve elevação da responsividade à insulina no ITT e redução da área sob a curva. CONCLUSÃO: O picolinato expressou ação de secretagogo e sensibilizador da ação insulínica, com expressão mais significativa nos músculos envelhecidos.

  20. Efecto de la asociación alga-bacteria Bostrychia calliptera (Rhodomelaceae en el porcentaje de remoción de cromo en laboratorio

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    Ana Lucía Rengifo-Gallego

    2012-09-01

    Full Text Available Para determinar el porcentaje de remoción de cromo en la asociación alga-bacteria, se tomaron ejemplares del alga Bostrychia calliptera de pneumatóforos de Avicennia germinans y Rizophora mangle, en la desembocadura del Río Dagua, Pacífico colombiano. El ensayo se realizó in vitro en agua marina sintética a dos concentraciones de cromo 5 y 10mg/L, empleando biorreactores con cuatro tratamientos; i material Alga-Bacteria (AB, ii material algal con antibiótico Alga-antibiótico (AA, iii consorcio bacteriano natural (CBN y iv control sin presencia de B. calliptera ni bacteria. Se monitoreó el comportamiento de poblaciones bacterianas y el porcentaje de disminución de cromo mediante AAS (Espectroscopía de absorción atómica. Se obtuvo diferencias significativas entre los tratamientos Alga-bacteria (AB y el consorcio bacteriano natural (CBN, siendo Alga-bacteria más eficiente a 10mg/L (87%. El consorcio bacteriano natural CBN obtuvo mayor porcentaje de remoción a bajas concentraciones de cromo a 5ppm (62.85%. Los resultados mostraron una interacción positiva entre las bacterias asociadas (CBN a la superficie del alga roja B. calliptera en su proceso acumulativo de cromo.

  1. Considerações sobre cromo, insulina e exercício físico Consideraciones sobre cromo, insulina y ejercicio fisico Considerations about chromium, insulin and physical exercise

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    Mariana Rezende Gomes

    2005-10-01

    Full Text Available O cromo é um mineral-traço essencial presente em diminutas proporções em alguns alimentos como carnes, cereais integrais, oleaginosas e leguminosas. Atualmente, esse mineral tem sido utilizado como suplemento alimentar no meio esportivo com a proposta de promover maior ganho de massa muscular e maior perda de gordura corporal. Todavia, a participação do cromo no metabolismo resume-se ao aumento da sensibilidade à insulina, por meio da ligação de quatro átomos de cromo a uma proteína intracelular específica denominada apocromodulina, que, por sua vez, liga-se ao receptor de insulina de células de tecidos periféricos concomitantemente à insulina, porém em outro sítio localizado no domínio intracelular. Essa ligação amplifica a cascata de sinais intracelulares responsáveis pelo estímulo da translocação de GLUT4 e, conseqüentemente, aumenta a captação de glicose e aminoácidos. O cromo também inibe a enzima-chave da síntese de colesterol, melhorando o perfil lipídico de indivíduos com dislipidemias. Não são significativas as alterações de composição corporal em esportistas, mas, por outro lado, a suplementação com cromo pode, em alguns casos relatados, melhorar o perfil lipídico e o quadro de diabetes tipo 2 de indivíduos que sofrem destes desequilíbrios metabólicos.El cromo es un mineral traza esencial presente en proporciones pequeñas en algunos alimentos como carnes, cereales integrales, oleaginosas y leguminosas. Actualmente, este mineral ha sido utilizado como suplemento alimenticio en el medio deportivo con la propuesta de promover mayor ganancia de masa muscular y mayor pérdida de grasa corporal. Todavía, la participación del cromo en el metabolismo se resume al aumento de la sensibilidad a la insulina, por medio de la unión de cuatro átomos de cromo a una proteína intracelular específica denominada apocromodulina que, a su vez, se liga al receptor de insulina de células de tejidos perif

  2. Propriedades texturais e catalíticas de óxidos de ferro contendo cromo e cobre Textural and catalytic properties of chromium and copper-doped iron oxides

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    Marluce Oliveira da Guarda Souza

    1998-07-01

    Full Text Available Chromium and copper-doped hematites were prepared with the aim of studying the synergistic effect of these dopants on the textural and on the catalytic properties of the iron oxides towards the high temperature shift reaction. It was found that the most active catalysts were those with the highest amount of copper. They had the Fe(II/Fe(III ratio near the stoichiometric value of magnetite, the highest surface areas under the reactional atmosphere and the greatest tendency to produce the active form; they also were poorly crystalline solids. The best performance was shown by the catalyst with Fe/Cu=10, heated at 300ºC. It can thus be concluded that copper acts both as textural and structural promoter in these catalysts.

  3. USO DE ESCHERICHIA COLI PARA BIORREMEDIACIÓN DE EFLUENTES CONTAMINADOS POR CROMO (VI

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    María C. Panigatti

    2012-01-01

    Full Text Available El objetivo del trabajo fue estudiar el uso de la Escherichia coli en la detoxificación de aguas residuales con Cr (VI perteneciente a una planta metalmecánica. Se evaluó el crecimiento y desarrollo de E. coli con distintas concentraciones de Cr (VI, en diferentes tiempos y condiciones de trabajo. Se estudió la biorreducción de cromo utilizando la cepa en estudio, en diferentes soportes y se evaluó la influencia de la presencia de metales tales como plomo, níquel y zinc. La bacteria fue capaz de reducir Cr(VI trabajando con concentraciones de hasta 200 mg . L-1. Se comprobó la adaptabilidad de la cepa para adoptar como mecanismo de detoxificación, la biorreducción del metal pesado. La presencia de otros metales como plomo, níquel y zinc retrasa el proceso, pero no lo inhibe totalmente. Los resultados obtenidos demuestran la posibilidad de utilizar E. coli en la biorremediación de un efluente industrial conteniendo Cr(VI.

  4. Suplementação oral com picolinato de cromo em pacientes com diabetes tipo 2: um ensaio clínico randomizado

    OpenAIRE

    Paiva, Ana Nunes

    2015-01-01

    Diante da importância do papel do cromo no mecanismo da sensibilidade à insulina tem sido estudada a suplementação com este mineral em pacientes diabéticos. Assim, o objetivo deste estudo foi avaliar o efeito da suplementação oral com picolinato de cromo (PicCr) nas concentrações glicêmicas, lipidêmicas, perfil antioxidante e parâmetros antropométricos em pacientes com diabetes mellitus tipo 2 (DM2) mal controlados(hemoglobina glicada A1c (HbA1c) ≥ 7%). Para tanto, foi conduzido um ensaio clí...

  5. Estudio de la recuperación de cromo hexavalente mediante un reactor electroquímico de compartimentos separados por separadores cerámicos

    OpenAIRE

    REYES PINEDA, HENRY

    2011-01-01

    La Tesis Doctoral "Estudio de la recuperación de cromo hexavalente mediante un reactor electroquímico de compartimentos separados por separadores cerámicos" se centra en la posibilidad de recuperación del cromo hexavalente procedente de las disoluciones de mordentado de las industrias de metalizado de plásticos mediante la utilización de un reactor electroquímico de compartimentos separados por separadores cerámicos fabricados a diferente presión y diferente composición de almidón. Con la rec...

  6. Reducción de percloroetileno y cromo hexavalente mediante FE(0) y bioestimulación de microorganismos anaerobios

    OpenAIRE

    VÁZQUEZ MORILLAS, Alethia; VACA MIER, Mabel; BELTRÁN VILLAVICENCIO, Margarita; LÓPEZ CALLEJAS, Raymundo; ÁLVAREZ, Pedro J

    2007-01-01

    En este trabajo se estudiaron las interacciones Fe-microorganismos simulando el entorno de una barrera reactiva permeable (BRP), para la reducción de percloroetileno (PCE) y cromo hexavalente en acuíferos contaminados. La bioestimulación de los microorganismos se llevó a cabo mediante la adición de un cosustrato para el desarrollo de las comunidades microbianas presentes de manera natural en el suelo. Se empleó un compuesto comercial que libera hidrógeno (HRC, por sus siglas en inglés) a tasa...

  7. Anormalidades Cromosómicas en la Microsporogénesis de Aloe Vera (L.) Burm. F. (Aloaceae)

    OpenAIRE

    IMERY BUIZA, José; CEQUEA RUÍZ, Hernán

    2002-01-01

    El objetivo del presente trabajo es verificar la existencia de anormalidades cromosómicas asociadas a la baja fertilidad del polen en Aloe vera. El estudio se realizó a partir del aplastamiento de anteras inmaduras fijadas en etanol-acético y coloreadas con orceína. La viabilidad del polen se determinó en microcultivos de agar y sacarosa. Las anormalidades más frecuentes en meiosis I fueron: quiasmas persistentes entre homólogos grandes y desplazamiento precoz de cromosomas pequeños, uno o má...

  8. Tratamiento de disoluciones que contienen cromo hexavalente mediante electrocoagulación con ánodos de hierro

    OpenAIRE

    ARROYO NÚÑEZ, MARÍA GUADALUPE

    2011-01-01

    Los residuos de cromo hexavalente y sus compuestos se originan en industrias tales como la fabricación de coches, el refino del petróleo, el tratamiento de superficies, la preparación de cromato, las industrias de fertilizantes y las industrias que emplean componentes de Cr(VI) como inhibidores de la corrosión. Los compuestos derivados del Cr(VI) son muy contaminantes, tienen un efecto altamente oxidante y facilidad para penetrar en membranas biológicas, además de ser cancerígenos para los...

  9. Avaliação da fundibilidade de uma liga de cobalto-cromo

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    CARREIRO Adriana da Fonte Porto

    1999-01-01

    Full Text Available Neste trabalho propusemo-nos a avaliar a fundibilidade de uma liga de cobalto-cromo (VERA-PDI em função da utilização de três revestimentos: Knebel (aglutinado por sílica, Termocast e Wirovest (aglutinados por fosfato e duas temperaturas de aquecimento para o molde (900°C e 950°C. Para a execução do teste foi utilizado o método descrito por HINMAN et al.9 (1985. O método de fundição foi o de cera perdida sob chama de gás-oxigênio. Os dados obtidos foram submetidos a análise estatística e demonstraram não haver diferença estatisticamente significante para os revestimentos Knebel e Wirovest, e diferença estatisticamente significante ao nível de 0,1% para o revestimento Termocast quando da variação da temperatura de aquecimento do molde. Quando analisamos os revestimentos sob temperatura do molde de 900°C verificamos diferença estatisticamente significante entre Knebel e Termocast e Knebel e Wirovest ao nível de 0,1%, e diferença entre Termocast e Wirovest ao nível de 5%. Para a temperatura de 950°C houve diferença estatisticamente significante ao nível de 0,1% entre todos os revestimentos. Dentro dos parâmetros utilizados neste estudo pudemos concluir que, para a liga VERA-PDI, a utilização do revestimento Knebel e temperatura de aquecimento do molde de 950°C proporcionaram melhores resultados quanto à fundibilidade.

  10. CUERPO Y MODERNIDAD EN COLOMBIA DURANTE LA DÉCADA DE LOS CUARENTA: AN APPROACH FROM CROMOS MAGAZINE

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    Harvey Murcia Quiñones

    2015-01-01

    Full Text Available Este artículo presenta las maneras como el cuerpo fue registrado visual y textualmente en una de las revistas más importantes a mediados del siglo XX en Colombia: Cromos. El trabajo tiene como propósito resaltar las tensiones y los regímenes semióticos con los que el lenguaje empieza a experimentar la realidad social y el cuerpo. El periodo de tiempo analizado va desde 1940 hasta 1949, años marcados por la violencia, bonanzas económicas y rupturas en las políticas culturales y gubernamentales. En esta época también se dinamiza la idea de una modernidad más industrializada -más fabricada- y aumentan las narrativas sobre la ciudad como forma discursiva. Así, lo que se quiere resaltar es cómo en la revista Cromos se exterioriza una forma de enunciar un cuerpo, las estrategias semióticas y narrativas sobre cuerpo para dotarlo de un sentido más cercano a las propuestas que implicaban los cambios sociales del periodo a analizar.

  11. Suplementação com cromo e desempenho reprodutivo de vacas zebu primíparas mantidas a pasto

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    Aragón V.E.F.

    2001-01-01

    Full Text Available Foram utilizadas 126 vacas zebu primíparas, mantidas a pasto durante a estação de monta, divididas em dois grupos, suplementado (72 animais e controle (54 animais, com o objetivo de estudar a influência da suplementação com cromo (Cr sobre algumas características reprodutivas. Utilizou-se como fonte de cromo a levedura Sacharomices cerevisae adicionada à mistura mineral (0,017% Cr. Não houve diferença significativa nos pesos das crias ao nascer e ao final do experimento. O peso final das vacas foi maior no grupo suplementado (428,5kg vs. 380,5kg. A porcentagem de animais em estro foi maior no grupo suplementado (98,6% vs. 88,7% e a porcentagem total de prenhez apresentou apenas tendência em ser maior no grupo suplementado (87,5% vs. 75,47%. O intervalo parto-primeiro cio foi menor nos animais que receberam Cr (120,5 dias vs. 142,8 dias. O número de doses de sêmen por vaca inseminada (1,57 e por vaca gestante (1,85 no grupo controle foi semelhante ao de vacas inseminadas (1,69 e gestantes (1,90 no grupo suplementado.

  12. BIOADSORCIÓN DE CROMO (VI EN SOLUCIÓN ACUOSA POR LA BIOMASA DE AMARANTO (Amaranthus caudatus

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    Adriana Rodríguez

    2017-01-01

    Full Text Available Se analizó la capacidad de remoción de Cromo (VI en solución acuosa por la biomasa de Amaranto, por el método de la d ifenilcarbazida. La mayor bioadsorción (100% con 100 mg/L del metal fue a las 4 horas, a pH de 1.0, 28 o C y 5 g de biomasa . Con respecto a la temperatura, la más alta remoción fue a los 60 o C, con un 100% de remoción a los 75 minutos. A las concentraciones de Cromo (VI analizadas, la biomasa natural mostró una excelente capacidad de remoción, además de que re mueve eficientemente el metal in situ (72% y 63% de remoción en tierra y agua contaminadas, a los 7 días de incubación con 2 5 g de la biomasa . Los resultados muestran que el biosorbente utilizado remueve Cr(VI , de aguas residuales industriales , satisfact oriamente .

  13. PENETRACIÓN Y DISOLUCIÓN DEL REFRACTARIO DE CROMO-MAGNESIO POR ESCORIAS FAYALÍTCAS

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    VANESA BAZÁN

    2012-01-01

    Full Text Available Los refractarios magnesia-cromo se han utilizado con éxito en diferentes procesos metalúrgicos a altas temperaturas, tales como hierro y acero, la industria del cemento y procesos pirometalúrgicos no ferrosos. En particular en la fundición, en los procesos de conversión de refino de cobre. Esos materiales tienen buenas características en relación con el uso y los requisitos de resistencia al choque térmico. Sin embargo, representan un problema importante en la contaminación del medio ambiente. El objetivo de este estudio fue investigar las interacciones entre la escoria generada en el convertidor Peirce-Smith e cobre y los ladrillos refractarios de magnesia-cromo ladrillos. Los fenómenos de infiltración y ataques químicos en el material refractario causado por la escoria formada durante el proceso de conversión de cobre se han estudiado mediante el desarrollo de las diferentes pruebas de laboratorio a temperaturas de hasta 1300 ° C.

  14. Contaminación aguda por vertidos textiles: Tratamiento de carpines dorados (Carassius auratus) con dicromato potásico; determinación de la toxicidad y niveles de cromo en branquias.

    OpenAIRE

    Riva Juan, María del Carmen; Flos Bassols, Rosa; Crespi Rosell, Martí; Balash, J.

    1980-01-01

    El cromo es el metal pesado cuantitativamente más importante en el vertido de la Industria Textil; procede esencialmente de los procesos de tintura con colorantes cromatables. Hemos sometido carpines dorados al tratamiento agudo con dicromato potásico disuelto en el agua de tanques experimentales. Se determina la toxicidad y los niveles de cromo en branquias. La concentración de cromo en el tejido branquia1 se halla mediante espectrofotometría de absorción atómica, previa digestión c...

  15. Medicina, Reordenamientos Cromosómicos y sus Bases Moleculares en los Procesos Oncohematológicos

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    Jorge J. Yunis

    1993-08-01

    Full Text Available

    Sus posibilidades en el diagnóstico, como criterio pronóstico y para la detección de la enfermedad residual

    Introducción

    Se ha demostrado claramente que en pacientes con enfermedades neoplásicas existen frecuentemente reordenamientos genómicos específicos. Uno de los mecanismos de transformación mejor entendido es el que tiene lugar en un gran número de leucemias y linfomas del tipo no-Hodgking. En ellos se ha observado la existencia de un defecto específico estructural clonal a nivel cromosómico. Frecuentemente, el defecto consiste en una translocación recíproca, con dos puntos de ruptura muy precisos. Uno de estos puntos de ruptura se sitúa en el lugar de un proto-oncogén que se desregula por causa del reordenamiento cromosómico.

    Esta falta de regulación, después del reordenamiento, es de efecto dominante, en el que un proto-oncogén se transforma en oncogén. Con el reordenamiento cromosómico puede resultar que el segmento de un proto-oncogén se fusiona con el segmento de otro gen en el segundo cromosoma, creando un defecto único o específico de cáncer en el cual el nuevo gen híbrido produce una proteína de fusión (por ejemplo la fusión de los genes BCRI ABL in la t(9;22 de la leucemia mieloide crónica.

    Alternativamente el proto-oncogén de un cromosoma se desregula por su proximidad a una secuencia reguladora de otro gen en el segundo cromosoma. En este caso el proto-oncogén convertido en oncogén mantiene la estructura proteica normal pero se produce anormalmente (por ejemplo MYC an la t(8;14 en ellinfoma de Burkitt.

    Anivel clínico, el análisis cromosomal es un instrumento de diagnóstico eficaz. Por ejemplo, cuando se utilizó el análisis cromosómico de alta resolución en un estudio de más de 800 pacientes con cáncer, llevado a cabo en nuestro laboratorio, se pudo determinar que las células malignas de la mayor parte de los tumores

  16. EFEITOS DO CROMO HEXAVALENTE SOBRE O CRESCIMENTO DE RAÍZES E CICLO CELULAR NO MERISTEMA DA PONTA DA RAIZ DE Allium cepa

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    Mary Helen Pestana da Costa

    2016-09-01

    Full Text Available O Cromo hexavalente [Cr (VI] é classificado pela Agência Internacional de Pesquisa sobre Câncer (IARC como cancerígeno para os seres humanos. A principal fonte de contaminação ambiental pelo cromo em ecossistemas aquáticos está relacionada com a aplicação industrial deste metal. No presente estudo, foram avaliados os efeitos citotóxicos e genotóxicos do Cr (VI no ciclo celular de células do meristema da raiz de Allium cepa. O teste foi usado para avaliar efeitos do cromo na germinação de sementes, alongamento das raízes, índice mitótico e indução de micronúcleos e anomalias do ciclo mitótico. Sementes de A. cepa foram germinadas em cinco diferentes condições: (1 controle negativo, água destilada; (2 grupo T1, tratado com dicromato de potássio a 6 mg.L-1; (3 grupo T2, tratado com dicromato de potássio a 12 mg.L-1; (4 grupo T3, tratado com dicromato de potássio a 24 mg.L-1; (5 controle positivo, tratado com NMU (N-nitroso-N-metilureia a 0,125 mg.L-1. As análises estatísticas efetuadas foram ANOVA e coeficiente de correlação de Pearson. Mesmo sem afetar o índice de germinação de sementes e o alongamento das raízes, os resultados demonstraram efeitos citotóxicos sobre o índice mitótico, bem como efeitos genotóxicos do cromo hexavalente. Palavras-chave: Cromo, Allium cepa, ciclo celular, citotoxicidade, genotoxicidade.

  17. Determinación de cromo hexavalente sobre el crecimiento de Selenastrum capricornutum

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    Giovanna Lida Arboleda Díaz

    2002-01-01

    Full Text Available Sobre cultivos de Selenastrum capricornutum, se ensayaron algunas condiciones ambientales,como iluminación (continua y fotoperíodo, agitación (continua y manual y nutricionalescomo la relación nitrógeno y fósforo (N:P, 50:1 y 25:1 en el medio de cultivo. (En este casosobre el medio sugerido por la EPA (1994. La finalidad de estos experimentos era la de de-terminar y escoger las condiciones con las cuales se habría de trabajar en el laboratorio, tantopara el mantenimiento y propagación del cultivo como para la realización de pruebas de toxici-dad de Selenastrum capricornutumcon Cromo hexavalente (Cr+6 . Fue evidente que cada uno delos factores tuvo un efecto directo sobre el crecimiento, sin embargo en la selección de lascondiciones se debió tener en cuenta que los resultados fueron una suma de factores queinteractuaban de manera simultánea en el tiempo sobre los cultivos. Finalmente, los análisisllevaron a la selección de las condiciones de iluminación continua, con una intensidad de 4000Lux, agitación continua a 100 rpm y la relación N:P en el medio de cultivo de 50:1. Una vezfueron establecidas las condiciones con las que se debía trabajar en el laboratorio se procedióa realizar los ensayos de toxicidad, se determinó la CI50-72h (concentración inhibitoria cin-cuenta a las setenta y dos horas de Selenastrum capricornutumcon Cr+6, obteniendo la cartacontrol, y cuyo valor al tóxico de referencia fue de 0.127mg/l, con un coeficiente de variaciónde 18.6%, y con un intervalo de sensibilidad de 0.080-0.174mg/l.

  18. Redução química e biológica do cromo hexavalente aplicado ao solo

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    D. D. Castilhos

    2001-06-01

    Full Text Available Realizou-se um experimento em laboratório, com o objetivo de avaliar não só a redução do cromo hexavalente aplicado ao solo com ênfase ao efeito da aplicação de carbono orgânico, manganês divalente, mas também a participação da microbiota do solo. Utilizaram-se, como unidades experimentais, amostras de 50 g de um Argissolo, acondicionadas em sacos de polipropileno e incubadas durante 42 dias com calcário para elevar o pH a 6,0 (2,0 t ha-1 de CaCO3 + MgCO3 na proporção de 2:1, Cr6+, esterco bovino e Mn2+ nas doses de 20, 50 e 40 mg kg-1, respectivamente. Metade das amostras foi sujeita à esterilização por autoclavagem com o objetivo de eliminar a atividade biológica. A aplicação de esterco bovino e sulfato de manganês promoveu a total redução do cromo hexavalente para cromo trivalente (Cr6+ → Cr3+ no solo, em 42 dias. Os modelos, quadrático e exponencial, foram os que melhor descreveram a cinética de redução com o tempo. A redução do Cr6+ foi estimulada pela atividade microbiana, sendo 16% maior em amostras de solo não esterilizadas, que continham esterco bovino, em comparação com as mesmas amostras esterilizadas por autoclavagem. Os resultados demonstraram que a descontaminação do solo que contém teores tóxicos de Cr6+ pode ser viabilizada tanto pela incorporação de adubo orgânico como pela manutenção de sua atividade biológica.

  19. Propriedades ópticas e estruturais de óxido de zinco contendo enxofre

    OpenAIRE

    Gabriela Zanotto Bosshard

    2012-01-01

    Resumo: O objetivo deste projeto foi investigar a síntese de óxido de zinco contendo enxofre obtido a partir de sulfeto de zinco nas fases wurtzita (hexagonal) e blenda de zinco (cúbica), assim como fazer a caracterização e estudar as alterações estruturais e ópticas dos materiais sintetizados e compará-las às propriedades do óxido de zinco sintetizado a partir de hidroxicarbonato de zinco. O método de síntese utilizado permite a obtenção de sulfeto de zinco hexagonal ou cúbico a baixa temper...

  20. Remoción de cromo y demanda química de oxígeno de aguas residuales de curtiembre por electrocoagulación

    OpenAIRE

    Mayta, Roddy; Mayta, Jhony

    2017-01-01

    Se estudió la remoción de cromo III y demanda química de oxígeno (DQO) de muestras de aguas residuales de curtiduría por electrocoagulación (EC) en un reactor electroquímico de operación discontinua. La influencia de los tiempos (15 a 45 min), voltajes (5 a 10 V), diluciones (0 a 2) y sus interacciones en el proceso de EC fueron significativos (p

  1. Evaluación del efecto tóxico del acetato plomo y el cloruro de cromo sobre el metabolismo bacterial anaerobio

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    Beatriz Wills

    2004-01-01

    Full Text Available Se presentan los resultados del estudio de toxicidad del cloruro de cromo (CrCl3 y el acetato de plomo (CH3COO2Pb del lodo de un reactor anaerobio de flujo ascendente y manto de lodos (UASB, aclimatado y estabilizado en el laboratorio con una solución de suero en polvo sintético; los ensayos de toxicidad se realizaron en botellas serológicas de 60 mL, se utilizaron como sustratos soluciones de ácido fórmico y suero en polvo sintético y se ensayaron concentraciones de cloruro de cromo en el rango de 1.000 a 5.000 mg/L, y de 1.000 a 10.000 mg/L para el acetato de plomo. Durante 72 horas se valoró la producción de metano en mL y el comportamiento del potencial redox en mV.Se presentaron reducciones del 50% en la producción de metano a concentraciones de 3.322 mg/L para cloruro de cromo y 1.415 mg/L para el acetato de plomo cuando el sustrato fue ácido fórmico, y a 2.291 mg/L para el cloruro de cromo y 1.982 mg/L para el acetato de plomo cuando el sustrato fue suero en polvo sintético.En síntesis, el artículo demuestra que las bacterias metanogénicas tienen un grado de resistencia cuantificable con respecto a las diferentes concentraciones de metales aplicados

  2. Chromosome complement and meiosis of Holmbergiana weyenberghii (Opiliones: Sclerosomatidae: Gagrellinae from Argentina Complemento cromosómico y meiosis de Holmbergiana weyenberghii (Opiliones: Sclerosomatidae: Gagrellinae de Argentina

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    Sergio G. Rodríguez Gil

    2010-12-01

    Full Text Available The cytogenetical analysis of the harvestman Holmbergiana weyenberghii (Holmberg (Eupnoi, Sclerosomatidae, Gagrellinae from Argentina is reported for the first time. The complement of males is composed of 18 chromosomes. In meiosis there are nine homomorphic bivalents: one large, five medium-sized and three small. The chromosome number of H. weyenberghii is within the range of diploid numbers of the subfamily Gagrellinae Thorell, which shows the lowest chromosome numbers among the sclerosomatids.Se analiza citogenéticamente, por primera vez, una especie de opilión proveniente de Argentina: Holmbergiana weyenberghii (Holmberg (Eupnoi, Sclerosomatidae, Gagrellinae. Los machos tienen un complemento cromosómico compuesto por 18 cromosomas. En meiosis, hay nueve bivalentes homomórficos: uno mayor, cinco medianos y tres menores. El número cromosómico de H. weyenberghii se encuentra dentro del rango de números diploides de los Gagrellinae Thorell; esta subfamilia presenta los números cromosómicos más bajos de Sclerosomatidae.

  3. Redução de cromo hexavalente por bactérias isoladas de solos contaminados com cromo Reduction of hexavlent chromium by isolated bacteria of contaminated soils with chromium

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    Daniele Conceição

    2007-12-01

    Full Text Available A redução do Cr(VI para Cr(III diminui a toxidade deste metal no ambiente, uma vez que o Cr(III é insolúvel às membranas biológicas. Assim, a redução microbiana do Cr(VI é uma alternativa para reduzir os impactos ambientais causados por este metal, utilizado em diversos processos industriais. O objetivo deste trabalho foi selecionar microrganismos a partir de solo contaminado com cromo e caracterizar sua capacidade de redução do Cr(VI durante o crescimento celular. A atividade de redução do Cr(VI pelos isolados foi quantificada com o reagente de s-difenilcarbazida. No isolamento, foram obtidas 20 bactérias resistentes a cromo(VI; seis destas foram capazes de reduzir acima de 100mg L-1 Cr(VI em 24 horas. As bactérias selecionadas foram eficientes na redução do Cr(VI e apresentam potencial para outros estudos, visando à aplicação em processos de biorremediação.The reduction of Cr(VI to Cr(III decrease the toxic effect of this metal in the environment, because Cr(III is insoluble to the biological membranes. The microbial reduction of Cr(VI it is an alternative to reduce the environmental impacts caused by this metal used in several industrial processes. The objective of this research was to select microorganisms from chromium contaminated soil and to characterize their ability to reduce Cr(VI. The activity of reduction of Cr(VI for the isolated was quantified with s-diphenylcarbazide. A group of 20 chromium resistant bacteria were isolated; six of these were able to reduce 100mg L-1 Cr(VI in 24 hours. The isolated bacteria, from contaminated soil can remediate chromate and presented potential for other studies seeking their application in bioremediation processes.

  4. Eficacia del medio de cultivo CromoCen(R CC en el diagnóstico de la infección urinaria Efficacy of the CromoCen (R culture medium in the diagnosis of urinary infection

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    Emilio Simón Barroso de la Cruz

    2006-12-01

    Full Text Available Se realizó la evaluación del desempeño con muestras clínicas de orina para determinar la eficacia del CromoCen(R CC como medio de cultivo en el diagnóstico de la infección urinaria, e identificar, con su utilización, los grupos bacterianos más frecuentes y el tiempo necesario para realizar el diagnóstico. En una muestra de 500 casos atendidos en la consulta externa de urología y realizados en el servicio de microbiología de San Antonio de los Baños, en la provincia de La Habana, en el período comprendido desde enero a junio de 2003. Se confirmó la hipótesis de trabajo: el medio de cultivo estudiado fue eficaz en el diagnóstico rápido de la infección urinaria. Desde el punto de vista ético se mantuvo la confidencialidad, se elevó la autoestima del binomio médico-paciente, y su calidad de vida desde el punto de vista bioético, por lo que se recomienda emplear este medio de cultivo en el diagnóstico rápido de la infección urinaria.The evaluation of the performance with clinical samples of urine was carried out to determine the efficacy of CromoCen(R CC as a culture medium in the diagnosis of urinary infection, and to identify with its use the most frequent bacterial groups and the time necessary to make the diagnosis. In a sample of 500 cases seen at the aoutpatient department of urology and analyzed at the microbiology service of San Antonio de los Baños, in the province of Havana, from January to June, 2003, it was confirmed the working hypothesis: the studied culture medium was efficient for the rapid diagnosis of urinary infection. From the ethical point of view, the reliability was maintained, and the self-steem of the physician-patient binomial, as well as the quality of life of the patient from the bioethical view increased. That's why, it is recommended to use this culture medium in the rapid diagnosis of the urinary infection.

  5. PRODUÇÃO DE QUEIJO TIPO QUARK FUNCIONAL CONTENDO EXOPOLISSACARÍDEOS

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    Tatia Tie Yuhara

    2015-01-01

    Full Text Available Alimentos com bactérias probióticas ou prebióticos estão incluídos na categoria de alimentos contendo compostos bioativos que tem despertado interesse devido ao efeito benéfico sobre a saúde. O objetivo do trabalho foi a formulação de produto simbiótico e funcional com bactérias láticas probióticas produtoras de exopolissacarídeos (EPS. Para isto, promoveu-se a fermentação por 24 h a 37 ºC de soro de leite em pó e leite desnatado em duas formulações: “F1” contendo o prebiótico goma acácia e inoculada de bactéria probiótica Lactobacillus casei LC1, e “F2” formulada com inulina como prebiótico e fermentação por L. acidophilus LA5. Nos produtos fermentados foi determinada a quantidade de EPS produzida pelos diferentes probióticos e os valores encontrados foram de 103,5 mg/100g (F1 e 109,2 mg/100g (F2. Verificou-se que os produtos apresentaram estabilidade microbiológica e físico-química com contagens de probióticos ao final de 21 dias de armazenamento refrigerado de 2,5x109 UFC/g, pH 3,98 e 32% de extrato seco total (EST para F1 e 6,0x108 UFC/g, pH 4,16 e 31,5% EST para F2, ausência S. aureus e de coliformes. Conclui-se que o queijo Quark funcional apresentou altas contagens de bactérias láticas probióticas e presença de EPS, níveis estes importantes para a ação como alimentos funcionais e sobrevivência no trato gastrointestinal.

  6. Resistência de união entre liga de níquel-cromo e cimentos resinosos

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    FRANÇA Rodrigo de Oliveira

    1998-01-01

    Full Text Available O objetivo do trabalho foi a determinação da retentividade, por ensaio de tração, entre uma liga de níquel-cromo e cimentos resinosos (Comspan, Panavia Ex e All-Bond C & B, com quatro tratamentos superficiais (liso, microjateado, ataque eletrolítico e silicoater e armazenagem por 3 e 30 dias em solução de NaCl a 0,9%, a 37° C e termociclagem intercalada na segunda (a 5 e 55° C, por 1 minuto em cada banho, perfazendo 600 ciclos. Os corpos de prova eram discos, providos de alça fixadora entre si dois a dois. Os resultados permitiram concluir que: superfícies lisas conduzem a baixíssimas retentividades e tratadas com silicoater a altíssimos valores, com qualquer cimento e condição de armazenagem; Panavia Ex com superfícies microjateadas também conduz a altas retentividades; a maior retentividade foi obtida pela combinação silicoater/All-Bond C&B.

  7. REMOCIÓN DE CROMO HEXAVALENTE DE AGUAS CONTAMINADAS USANDO QUITOSANO OBTENIDO DE EXOESQUELETO DE CAMARÓN

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    Yina Pájaro

    2013-08-01

    Full Text Available El exoesqueleto de camarón desechadopor la industria puede ser aprovechadopara la obtención de quitina y quitosanocon la utilización de reactivos comercialesde muy bajo costo. El quitosano esun biopolímero que tiene diversos usos,entre ellos, la remoción de metales pesadosa partir de aguas residuales. En esteestudio se utilizó quitosano para la remociónde cromo hexavalente a partir demuestras de aguas residuales del procesode galvanizado (cromado de una industriade Cartagena. La remoción de cromose realizó por un proceso discontinuo, aun pH óptimo encontrado en este estudiode 2.0 y una temperatura de 26 ºC. Lacinética de adsorción fue estudiada medianteel uso de la isoterma de Langmuir,siendo la capacidad máxima de adsorción(Qmax de 200 mg/g. La remoción de cromohexavalente a partir de las muestrasde aguas residuales fue del 99.98 %.

  8. Germination and sporophytic development of Regnellidium diphyllum Lindman (Marsileaceae in the presence of hexavalent chromium Germinação e desenvolvimento esporofítico de Regnellidium diphyllum Lindman (Marsileaceae na presença de cromo hexavalente

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    MA. Kieling-Rubio

    2010-12-01

    Full Text Available Regnellidium diphyllum Lindman is a heterosporous fern, growing in aquatic environments and surrounding wetlands, which is assumed to be threatened by increasing water pollution and disappearance of its natural habitats. Among contaminants, hexavalent chromium - Cr(VI - is known to be present in effluents from some leather tanning factories. Megaspore germination tests were performed using Meyer's solution, at concentrations 0 (control, 0.1, 0.5, 1, 5, 10, 15, 20, 30, 50, and 80 mg.L-1, from a standard solution of Titrisol® 1000 mg.L-1. The primary development of apomictic sporophytes was studied using solutions containing 0.025 to 4.8 mg.L-1 of Cr(VI. The experiments were conducted in a growth chamber at 24 ± 1 ºC and for a 12-hour photoperiod under fluorescent lights, providing a nominal irradiance of 77 µmol.m-2/s. Significant differences in megaspore germination, with subsequent sporophytic development, were verified from 0.5 mg.L-1 Cr(VI concentration onwards. Growth of primary root and primary and secondary leaves was significantly reduced at 3.2 mg.L-1 Cr(VI concentration or higher. Considering the pollution from Cr(VI in some areas of R. diphyllum natural occurrence, these data indicate that low reproductive rates and disappearance of populations are likely to occur in these situations.Regnellidium diphyllum Lindman é uma filicínea heterosporada que se desenvolve em ambientes aquáticos e áreas úmidas circundantes, sendo considerada ameaçada pelo aumento da poluição e desaparecimento dos seus hábitats naturais. Entre os contaminantes, o cromo hexavalente - Cr(VI - é conhecido por estar presente nos efluentes de algumas indústrias de curtimento de couro. Testes de germinação foram realizados em meio líquido de Meyer, com concentrações de 0(controle; 0,1; 0,5; 1; 5; 10; 15; 20; 30; 50; e 80 mg.L-1 de Cr(VI, a partir de uma solução padrão de Titrisol® a 1000 mg.L-1. O desenvolvimento primário dos esporófitos apom

  9. Determinación del contenido de compuestos de cromo en el cemento portland por espectrofotometría de absorción atómica. Segunda parte

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    Gaspar-Tebar, Demetrio

    1976-12-01

    Full Text Available Not availableEn un trabajo anterior (1 se ha puesto de manifiesto la importancia que tiene conocer el contenido de compuestos de cromo (III y de cromo (VI en el cemento portland, habiendo determinado dicho contenido en diversas 'muestras de distintos cementos, fabricados por la industria española, por espectrofotocolorimetría del complejo coloreado formado en la reacción que tiene lugar entre el cromo (VI y la s-difenilcarbacida, de tal modo que se puedan utilizar como patrones para estudiar y poner a punto un procedimiento rápido y preciso que utiliza la espectrofotometría de absorción atómica, objeto del presente artículo.

  10. Reproductive activity and performance of ½ Nellore and heifers fed with supplementation with organic chromium Atividade reprodutiva e desempenho produtivo de novilhas nelore taurino submetidas a suplementação com cromo orgânico

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    Joilmaro Rodrigo Pereira Rosa

    2011-06-01

    Full Text Available This experimental evaluated the start of reproductive activity, body weight gain and carcass finishing of two genetic groups of heifers submitted to mineral supplementation with organic chromium. 90 heifers with 12 months of age were divided into four groups: 30 Nellore with chromium, 30 Nellore without chromium, 15 ½ Taurine with chromium, 15 ½ Taurine without chromium. For 12 months the animals were weighed every 28 days and ultrasound exams performed with 15 months of age for reproductive evaluation and 18 months for carcass evaluation. There was interaction between genetic groups and organic chromium supplementation for body weight at slaughter and body weight gain. The ½ Taurine heifers supplemented with chromium showed greater body weight at slaughter (330.1kg and body weight gain (0,563kg/day than Nellore heifers with chromium (304.8kg; 0,414kg/day, Nellore without chromium (304.7kg; 0,401kg/day and ½ Taurine without chromium (298.6kg; 0,408kg/day. However there was no effect of interaction between genetic groups and chromium organic supplementation, of genetic groups and of chromium organic supplementation on carcass characteristic. The use of organic chromium supplementation showed improvements on body growth and on the start of reproductive activity in heifers, without changing the finishing carcass characteristic.O presente experimento avaliou o início da atividade reprodutiva, ganho de peso corporal e acabamento de carcaça de dois grupos genéticos de novilhas submetidas à suplementação mineral com cromo orgânico em pastejo sob lotação intermitente. Noventa novilhas (60 Nelore e 30 ½ taurino de 12 meses de idade foram separadas em quatro grupos: Trinta fêmeas Nelore com cromo, 30 fêmeas Nelore sem cromo, 15 fêmeas ½ sangue taurino com cromo e 15 fêmeas ½ sangue taurino sem cromo. Durante 12 meses os animais foram pesados a cada 28 dias e os exames ultrassonográficos realizados aos 15 meses de idade para avalia

  11. Karyotypic polymorphism and evolution within and between the Liolaemus monticola (Iguanidae "northern 2n = 38-40" chromosome race populations in central Chile Polimorfismo cromosómico y evolución intra e inter poblacional de la raza cromosómica "Norte 2n = 28-40" de Liolaemus monticola (Iguanidae en Chile Central

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    MADELEINE LAMBOROT

    2001-03-01

    Full Text Available Chromosomal genotypes were scored from 359 Liolaemus monticola lizards of the "northern, 2n = 38-40" chromosomal race from 21 locality samples between the Maipo (and one of its tributaries and the Aconcagua (and one of its tributaries ribers, plus a sample from the interracial hybridization zone, and some representative locality samples of the "southern 2n = 34" and the "multiple fission 2n = 42-44" chromosomal races for comparisons. The first seven variable chromosomal pairs were coded as Mendelian genotypes and statistically summarized by several clustering and population genetic algorithms. Spatial and temporal differentiation was assessed by chromosome frequencies, chromosomal diversity and heterozygosity. While no differentiation was found for diversity in the "northern 2n = 38-40" race, chromosomal frequencies and heterozygosity showed significant spatial differentiation that permit distinguishing between the coastal, Andean and transversal mountain range populations. The sample of Cuesta Chacabuco may represent a hybrid zone between the other two range samples. The origin of the chromosomal rearrangements, the population cytogenetics, and the recombination patterns resulting from chromosomal heterozygosity are compared in these chromosomal races, thus expanding the geographical area. These patterns are discussed with respect to the evolution of this complex in Chile and the importance of the riverine barriers in central ChileSe cuantificaron los "genotipos" cromosómicos para 359 lagartijas de 21 muestras poblacionales de la raza "Norte, 2n = 38-40" comprendida entre los ríos: río Maipo y uno de sus afluentes el río Yeso y río Aconcagua (y uno de sus afluentes el río Juncal. Con fines comparativos agregamos una muestra de la zona de hibridación interracial, algunas muestras representativas de la raza "Sur 2n = 34" y una de la raza "múltiples fisiones 2n = 42-44". Los siete primeros pares cromosómicos variables fueron codificados

  12. O uso e os impactos da reciclagem de cromo em indústrias de curtume em Mato Grosso do Sul, Brasil Usage and recycling of chromium at tanneries in Mato Grosso do Sul, Brazil

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    Tânia Christina Marchesi de Freitas

    2006-12-01

    Full Text Available Um estudo da dinâmica de emissão de cromo foi realizado em dois curtumes representativos de Mato Grosso do Sul. Apenas cromo III foi encontrado durante a investigação. Foram realizadas extensivas análises químicas de cromo nos efluentes e corpos receptores durante seis meses e os valores obtidos foram comparados com os da legislação existente. Demonstrou-se que, em alguns casos, a concentração de cromo atinge níveis ecologicamente perigosos, pois foram encontrados valores acima do permitido para águas. O processo de reciclagem de cromo em curtumes mostrou-se como um processo para a normalização das concentrações de cromo nas diferentes etapas de produção e na emissão desse elemento.A study of the dynamics of chromium emissions was carried out at two major tanneries operating in the State of Mato Grosso do Sul. Chromium III was the only species found during the investigation. Extensive chemical analyses for chromium were performed at the effluents and receptive sites for six months and the results were compared with the values required by the existing official acts, showing that they are were above ecologically dangerous levels. The concentrations of chromium in waters also were found to exceed the permissible values, but with a tendency toward reduction. Recycling was found to be the important operation capable of normalizing chrome concentrations at the various steps of production and in the release of this element into the environment.

  13. Aspectos fundamentais no desenvolvimento de sistemas microemulsionados contendo anfotericina B para uso oftálmico

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    Walteçá Louis Lima Silveira

    2013-01-01

    Full Text Available A exemplo do que ocorre com outros fármacos, a biodisponibilidade da anfotericina B (AmB através da via ocular repreesenta um grande desafio para a pesquisa científica. Na verdade, a baixa biodisponibilidade apresentada por tal molécula é devido, principalmente, a presença das barreiras oculares que impedem a absorção deste fármaco para os tecidos internos. A toxicidade associada a este fármaco, assim como a sua baixa capacidade em permear a córnea íntegra também consiste em um problema associado ao seu uso clínico. Novos veículos seguros e eficazes para a liberação ocular da AmB são, portanto, necessários. As microemulsões (MEs aparecem como um interessante sistema devido à sua transparência, estabilidade termodinâmica e favorável viscosidade. O conhecimento do processo de formação das MEs contendo AmB, assim como a compreensão de toda a sua caracterização físicoquímica correspondem a aspectos importantes para se determinar as condições favoráveis para que estes sistemas venham a ser empregados como colírios. Esta revisão tem como objetivo, portanto, abordar este tema enfatizando os principais aspectos relacionados com a utilização de MEs como sistemas de liberação para a AmB através da via tópica oftálmica.

  14. Cariotipo del pejelagarto tropical Atractosteus tropicus (Lepisosteiformes: Lepisosteidae y variación cromosómica en sus larvas y adultos

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    Lenin Arias-Rodríguez

    2009-09-01

    Full Text Available El cariotipo del pejelagarto Atractosteus tropicus se describe por medio de tinción Giemsa de 295 preparaciones cromosómicas en mitosis a partir de 120 larvas y 15 adultos (5 hembras y diez machos de la población que habita en Tabasco, sureste de México. El número diploide 2n=56 cromosomas se dio en 281 dispersiones cromosómicas de un total de 445 muestras, de ellas 73 dispersiones provinieron de 206 metafases larvales, y 208 dispersiones de 239 metafases de adultos. Se observó variación en el número de cromosomas desde 46 hasta 64 elementos cromosómicos (larvas. Las metafases con 58 cromosomas fueron el segundo valor más abundante, después del número diploide 2n=56 (35%. En los adultos esa variación no fue relevante. Esta variación cromosómica se relaciona con microcromosomas móviles. El cariotipo se determinó de seis dispersiones cromosómicas bien definidas de tres hembras y tres machos; y el cariotipo promedio se integró de ocho pares de cromosomas metacéntricos (m, cuatro pares de cromosomas submetacéntricos (sm, ocho pares de telocéntricos (t, y ocho pares de microcromosomas telocéntricos (*t El número fundamental observado en el cariotipo típico promedio fue NF = 80 brazos cromosómicos. No se detectaron diferencias sexuales.Karyotype of the tropical gar Atractosteus tropicus Lepisosteiformes: Lepisosteidae and chromosomal variation in their larval and adults. The karyotype of the tropical gar Atractosteus tropicus is described from conventional Giemsa-staining of 295 mitotic chromosome slides from 120 larvae and 15 adults (five females and ten males from Tabasco, southern of Mexico. The diploid number 2n = 56 chromosomes was calculated (73 spreads from 206 larval and 208 adult metaphases. Variation on chromosome number was from 46 (4.4% to 64 (3.9% chromosome elements on larval samples, whereas 58 (11.7 % chromosomes were the second most abundant after the diploid number of 2n = 56 (35%. Such variation was

  15. Repercusiones del picolinato de cromo en el metabolismo proteico en función de la edad Repercussions of chromium picolinate in the protein metabolism based on the age

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    M. J. González Muñoz; I. Meseguer; M. C. Martínez Para; M. V. Aguilar; A. Bernao

    2006-01-01

    Antecedentes: Comercializado como suplemento dietético, el picolinato de cromo ha sido promocionado como constructor muscular y como un agente de pérdida de peso, al incrementar el músculo esquelético por su acción sobre la insulina. Objetivo: En este estudio se ha evaluado el efecto que, la suplementación de la dieta de ratas en distintas etapas de crecimiento (infantil y puberal), con 500 µg Cr/día en forma de picolinato de cromo (12 días), tiene sobre su crecimiento y utilización pro...

  16. Planteamiento y evaluación de las aplicaciones de los productos obtenidos en la hidrólisis alcalina de las virutas de cromo generadas durante el procesamiento del cuero

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    Díaz, Andrea; Jiménez, Juliana; Pérez, Monica; Narváez Rincón, Paulo César

    2010-01-01

    Considerando el concepto de maximizar la reutilización de residuos sólidos de curtiembres en diversos usos industriales y la minimización del impacto ambiental que estos generan, se evalúan algunas aplicaciones de los subproductos obtenidos por la hidrólisis alcalina de las “virutas de cromo”5 generadas durante la etapa de rebalado en el procesamiento del cuero. El hidróxido de cromo obtenido transformado en sulfato de cromo mo- nobasico puede reutilizarse en el procesamiento del cuero co...

  17. Determinação das espécies de cromo nas cinzas da incineração de couro wet-blue em reatores de leito fixo e leito fluidizado

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    Clauren Moura Martins

    2001-01-01

    Este trabalho tem como objetivo a determinação quantitativa da concentração de cromo (III, VI e total) nas cinzas de serragem de couro wet-blue, incineradas em reatores de leito fixo nas temperaturas de 450, 550 e 650 C e reator de leito fluidizado nas temperaturas de 730, 780, 830 e 850 C, verificando se estes resultados estão dentro dos limites permitidos pelas normas ambientais brasileiras e, consequentemente, se em relação à concentração de cromo, os processos de incineração utilizados sã...

  18. Diversification of the Public Reader in Bogotá (1910- 1924. An Analysis of El Gráfico and Cromos Illustrated Magazines

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    Paula Andrea Marín Colorado

    2016-07-01

    Full Text Available El Gráfico (1910-1941 and Cromos (1916-present day were two widely recognized Colombian magazines of the first decades of the XX c. The objective of both of these publications was the (real and imaginary configuration of a wide reading public that would consolidate the editorial industry; a possible reason for the inclusion of literature as a comercial Enterprise in these publications. This study will examine the configuration of the reader, as part of the editorial project of both magazines, and the reading (and consumer practices evident in aspects such as advertising and the writing forms included, such as chronicles, short stories and literary criticism.

  19. Medición de la capacidad de chlorella vulgaris y scenedesmus acutus para la remoción de cromo de aguas de curtiembre

    OpenAIRE

    Ardila Forero, Liliana

    2012-01-01

    El proceso de curtido de pieles es una actividad contaminante debido a la liberación de agentes tóxicos al medio ambiente; el más importante de aquellos es el cromo trivalente, usado como agente curtiente. Se han planteado diferentes alternativas para la remoción de este metal del agua residual del proceso de curtido, incluyendo la optimización de los procesos y operaciones dentro de las curtiembres, y soluciones de final de tubo como los procesos fisicoquímicos de adsorción y precipitación a...

  20. Técnicas emergentes en medicina reproductiva: diagnóstico cromosómico del primer corpúsculo polar del ovocito

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    Dr. A. Crosby Javier, Ph.D.

    2010-05-01

    Las indicaciones más comunes para este tratamiento son: 1 evitar el aborto en pacientes con aborto recurrente sin explicación anatómica ni clínica; 2 mejorar las tasas de implantación en mujeres mayores de 37 años con antecedentes de procedimientos anteriores en los que se transfirieron embriones de buena calidad; 3 evitar el nacimiento de niños con enfermedades de origen cromosómico en mujeres mayores de 39 años.

  1. Tecnología para la gestión del alumbre de cromo (III) y potasio como pigmento cerámico

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    Morales-Rodríguez, Idalberto Clemente; Rivas-Fernández, Katia; Ferro-Nieto, Alyn; Moro-Muñoz, Wilson; Calzadilla-Liens, Alfredo

    2017-01-01

    Entre los desechos peligrosos que se generan en Cuba están los reactivos ociosos y caducados, algunos de los cuales contienen metales pesados. Estas sustancias se acumulan sin una disposición final, ni uso apropiado, con la finalidad de no contaminar el medio ambiente. En tal sentido, los autores proponen una alternativa de utilización para el alumbre de cromo (III) y potasio, al convertirlo en óxido por precipitación con un álcali para aplicarlo como pigmento cerámico. Además se presentan la...

  2. Extracción de cromo con disolventes orgánicos. I parte. Extracción con DEHPA

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    de Juan, D.

    1998-06-01

    Full Text Available Chromium and its compounds give toxic and/or hazardous characteristics to all those industrial wastes, solids or liquids, that contain them. Organic solvent extraction is a technique that allows the recovery of chromium contained in these residues. In this work the extraction of Cr(III from aqueous solutions with solutions of a cationic reactive (DEHPA in kerosene is studied. In the same way the stripping process was studied. It has been found that Cr(III and DEHPA react in a 1/1 molar ratio, being the extraction kinetics very fast. Final aqueous phase final pH influence extraction yield, so that it is necessary to work with pH values between 3 and 4. It must be added a modifier (isodecanol to the organic phase to avoid the formation of a third phase in the stripping process. The concentration of isodecanol has to be higher than 15 %, so the organic phase used was a solution of 12.5 % v/v DEHPA in kerosene and 20 % v/v isodecanol. The stripping process is slow and must be carried out in an oxidant alkalyne medium, thus an aqueous solution of NaOH and H2O2 was used. An increase in the concentration of NaOH and H2O2 leads to an increase in the stripping yield initially, and becomes stable when concentrations of NaOH and H2O2 used are higher than 0.45 N and 4 % v/v respectively.

    El cromo y sus compuestos confieren un carácter tóxico y/o peligroso a los residuos industriales, sólidos o líquidos, que los contienen. Una técnica que permite recuperar el cromo existente en estas sustancias es la extracción con disolventes orgánicos. En el presente trabajo se estudia la extracción del Cr(III presente en disoluciones acuosas con disoluciones de un reactivo de carácter catiónico (DEHPA en queroseno. Igualmente se estudia el proceso de reextracción. Se ha encontrado que el Cr(III y el DEHPA reaccionan mol a mol, siendo la cinética de extracción muy rápida. El pH final de

  3. REMOCIÓN DE CROMO VI DE SOLUCIONES ACUOSAS POR ADSORCIÓN SOBRE CARBONES ACTIVADOS MODIFICADOS

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    Nubia Céspedes

    2009-05-01

    Full Text Available En este trabajo se determina la adsorción de Cr6+ de disoluciones acuosas en dos carbones activados comerciales en función del grado de modificación (reducción, oxidación de la superficie de los adsorbentes con tratamientos térmicos en presencia de hidrógeno, oxígeno y ácido nítrico. La química superficial de los carbones activados originales y modificados se examina por los métodos de titulaciones de Böehm y descomposición con temperatura programada (DTP. Los ensayos de evaluación de la capacidad de adsorción se realizan con soluciones modelo de ión cromato y bajo distintas condiciones de concentración inicial, tiempo de contacto, pH del medio, temperatura y masa de adsorbente. Se comprueba que la modificación de la superficie de los adsorbentes afecta el grado de adsorción del ión cromato en la medida en que los sólidos tratados con H2 muestran la mayor  capacidad de remoción. Las variables que afectan favorablemente la extensión de la remoción de cromo son: concentración inicial de 100 ppm,  pH  inicial de  2,0, temperatura de 25 °C y  masa de adsorbente de 100 mg. 

  4. Avaliação da biodisponibilidade relativa de duas formulações contendo levocetirizina em voluntarios sadios

    OpenAIRE

    Milena Rodrigues Morita

    2008-01-01

    Resumo: Objetivo: Desenvolver e validar um método analítico para quantificação de levocetirizina em plasma humano. Além disso, a biodisponibilidade relativa de uma formulação contendo 5 mg de dicloridrato de levocetirizina (formulação teste e formulação referência produzida por Farmalab Indústrias Químicas e Farmacêuticas Ltda.) foi avaliada em trinta e seis voluntários sadios de ambos os sexos. Método: O plano de estudo utilizado foi aberto, randomizado, cruzado com um intervalo de washout d...

  5. Verificación analítica para las determinaciones de cromo hexavalente en aguas por espectrofotometría

    Directory of Open Access Journals (Sweden)

    Carlos Alberto Severiche Sierra

    2013-06-01

    Full Text Available En la actualidad la prestación de servicios analíticos de laboratorios, toma de forma ascendente más auge y utilidad. El efecto de un análisis de aguas es forjar resultados correctos y confiables, siendo la verificación de ensayos uno de los aspectos más importantes y factor clave para conseguir este propósito. La determinación de cromo hexavalente en aguas por colorimetría con la difenilcarbazida es la metodología analítica más usada y útil que se conoce en el ámbito científico técnico, principalmente, por su alta selectividad y también debatida por su reacción a las interferencias. En el presente estudio se hizo la valoración analítica del método espectrofotométrico para la determinación de cromo hexavalente en aguas; el objetivo de este trabajo fue confirmar correctamente la aplicación del método para el análisis de aguas. Se trabajaron muestras de diferentes tipos de agua: potable, residual y superficial, siguiéndose estrictamente los protocolos de verificación. Se encontraron resultados satisfactorios en precisión y exactitud con el fin de emitir resultados confiables y reales de la muestra analizada.

  6. Relación microestructura resistencia al desgaste de recubrimientos duros ricos en cromo y tungsteno aplicados por soldadura electrica (SMAW

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    Lisys Margarita León Sevilla

    2004-01-01

    Full Text Available Se comparó la microestructura y resistencia a la abrasión de recubrimientos duros depositados por soldadura sobre placas de acero estructural ASTM A36. Se utilizaron cinco electrodos comerciales, dos de bajo cromo, dos de alto cromo aplicados en una y dos capas y uno rico en tungsteno depositado en una capa La resistencia al desgaste fue evaluada en una máquina de rueda de caucho y arena seca construida según la norma ASTM G65-80. Como material abrasivo se utilizaron partículas de sílice con índice de finura AFS 50- 70. La caracterización de las microestructuras se realizó utilizando microscopía óptica y electrónica de barrido. Los resultados mostraron que el parámetro de resistencia a la abrasión no está directamente relacionado con dureza del material pero sí con el tipo, tamaño, forma, composición química y distribución de los carburos presentes en la matriz del recubrimiento. La mejor resistencia a la abrasión se obtuvo en depósitos con microestructura compuesta por carburos primarios (del tipo M7C3 en recubrimientos ricos en Cr o del tipo MC, M6C en recubrimientos ricos en W en una matriz eutéctica.

  7. Alteraciones cromosómicas en Leucemias mieloides agudas, un estudio de nueve años en 312 pacientes, implicaciones en el diagnóstico, pronóstico, tratamiento y seguimiento de la enfermedad

    Directory of Open Access Journals (Sweden)

    G. Guevara

    2001-07-01

    Full Text Available Definir el tipo, frecuencia y distribución de las alteraciones cromosómicas presentes en una población colombiana con diagnóstico de leucemia mieloide aguda. Determinar su asociación con las características clinicopatológicas y analizar su impacto sobre la sobrevida de los pacientes.

  8. Relación entre factores micro- estructurales e impacto repetido en aleaciones de alto cromo para bolas de molino.

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    E. Albertin

    2008-01-01

    Full Text Available Las aleaciones de alto cromo son empleadas para la fabricación de bolas de molino en industrias de procesamiento de minerales. Los usuarios y fabricantes requieren lograr mejores resultados técnicos-económicos en sus aplicaciones, por lo que necesitan aumentar los conocimientos relacionados con los aspectos estructurales de estos materiales. En este trabajo se realiza una investigación con vistas a establecer relaciones entre la estructura de las aleaciones y su comportamiento ante el impacto repetido que es un fenómeno característico en estos procesos. Se funden bolas con varias aleaciones hipo eutécticas, eutécticas, e hipereutécticas; se prueban en un equipo que simula el impacto repetido. Los resultados permiten comprobar los buenos resultados de aleaciones hipo eutécticas con relaciones de Cr/C altas y a su vez altos contenidos de Cr y de aleaciones eutécticas para menores relaciones de Cr/C y menores contenidos de Cr, en ambos casos los carburos eutécticos son de forma simétrica, regulares y no forman redes continuas de carburos asimétricos bordeando los granos, que presentan peores comportamiento en el impacto repetido y que son el caso de las hipoeutécticas con bajas relaciones Cr/C y las hipereutécticas donde aparecen también grandes carburos primarios.High Chromium alloys are used to manufacture grinding balls for the Industry of Construction Materials. Customers and users need to improve their knowledge about the relationships between microstructure and the parts damage in these alloys to obtain better technical-economics results. In this paper the results of a research to obtain different microstructures of eutectics, hipoeutectics and hipereutectics alloys are presented, searching for the lesser damage in these alloys. These alloys are tested in a repeated impact testing machine that simulate its mechanical behaviour .The results show a good behaviour for hipoeutectic alloys with high relations of Cr/C and high

  9. Crescimento inicial de mudas de Acacia mangium cultivadas em mantas de fibra de coco contendo substrato de lodo de esgoto

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    Rômulo Fredson Duarte

    2011-02-01

    Full Text Available O objetivo deste trabalho foi avaliar o crescimento inicial de mudas de Acacia mangium semeadas em "manta" de fibra de coco contendo substrato de lodo de esgoto. O delineamento experimental foi em blocos casualizados com 13 tratamentos e três repetições, distribuídos em esquema fatorial (6 x 2 + 1 com seis proporções de fibra de coco e resíduo agregante, combinados com substratos com e sem lodo de esgoto, mais o tratamento-controle (terra de subsolo. Foram avaliados o índice de velocidade de emergência (IVE, a percentagem de emergência (EM e a altura das plantas aos 40 e 60 dias após a emergência. O tratamento- controle apresentou melhores resultados em relação ao IVE e EM quando comparado com os tratamentos utilizando "manta" de fibra de coco e resíduo agregante. Não houve diferença entre o controle e os tratamentos com "mantas" em altura das plantas aos 40 e 60 dias. Não foram observadas interações entre o tipo de substrato utilizado no semeio e as diferentes proporções de fibra de coco na "manta". A presença de lodo no substrato não influenciou o IVE e a EM, contudo verificou-se que o substrato sem lodo de esgoto proporcionou maior crescimento em altura das plantas. O uso de "mantas" contendo 50 e 100% de fibra de coco proporcionou maior crescimento às mudas de acácia em condições de campo.

  10. Separación selectiva de hierro y cromo de las lejías agotadas del decapado de acero inoxidable

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    Gálvez, J. L.

    2005-12-01

    Full Text Available Stainless steel spent pickling baths are very complex solutions of metals and acids (HNO3 and HF and are a very important environmental concern. Several processes have been developed for acid recovery (free and bounded acid with techniques like acid retardation, solvent extraction, evaporation and dialysis diffusion. In these processes, metallic content is precipitated and treated for its disposal. We have developed a process that permits the separation of metals by means of a selective precipitation, induced by adding free fluoride. Iron (Fe and chromium (Cr precipitate as pentafluorides and nitrogennickel (Ni remains in solution. After this stage, complex fluorides can be hydrolized with alkali to give iron and chromium hydroxides, releasing fluoride in solution

    Los baños ácidos agotados del decapado de acero inoxidable son disoluciones muy complejas debido al alto contenido de metales y ácidos (HNO3 y HF, por lo que constituyen un grave problema medioambiental. Existen tratamientos comerciales para la recuperación del ácido (libre o complejado que se basan en técnicas de retardo ácido, extracción con disolventes, evaporación o membranas. En estos procesos el contenido metálico es precipitado y tratado como un residuo. El grupo de investigación formado por los autores del presente trabajo ha desarrollado un procedimiento que permite el aprovechamiento de dichos metales mediante su recuperación selectiva con una técnica de precipitación modificada inducida por fluoruro libre. Se consigue la precipitación de hierro (Fe y cromo (Cr como pentafluoruros (pH 3-4,5 dejando el níquel en disolución. Posteriormente, los fluoruros complejos son hidrolizados con álcali dando lugar a hidróxidos de hierro y cromo, mientras que el fluoruro es redisuelto.

  11. Biossorção de níquel e cromo de um efluente de galvanoplastia utilizando alga marinha pré-tratada em coluna = Biosorption of nickel and chromium from a galvanization effluent using seaweed pre-treated on a fixed-bed column

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    Márcia Teresinha Veit

    2009-04-01

    Full Text Available Este trabalho teve por objetivo o estudo da biossorção dos íons cromo e níquel presentes no efluente do processo de uma indústria de galvanoplastia, utilizando como biossorvente a biomassa de alga marinha pré-tratada Sargassum filipendula. As condições deoperação da coluna foram: massa de biossorvente de 8 g, pH do efluente de alimentação 3,85, temperatura de 30ºC, vazão de 6 mL min.-1 e concentrações iniciais de alimentação (cromo+níquel de 7,12 e 3,66 meq L-1. Foi empregado um modelo matemático para representar a dinâmica da biossorção em coluna de leito fixo. O modelo da isotermamulticomponente de Langmuir (qm= 2,78 meq g-1, bCr = 0,85 L meq-1, bNi = 0,08 L meq-1 foi utilizado para representar os dados de equilíbrio da coluna e para simular a dinâmica de biossorção dos íons. Os resultados da simulação demonstraram que o modelo matemáticoempregado foi capaz de descrever satisfatoriamente a complexa dinâmica de biossorção dos íons presentes no efluente.This work investigated the biosorption of chromium (III and nickel (II present in the effluent of a galvanoplasty plant using the pre-treated biomass of Sargassum filipendula seaweed. The column operation conditions were 8 g of biosorbent mass, 3.85 pH for the feed effluent, 30ºC temperature, 6 mL min.-1 flow rate, 7.12 meq L-1 initial chromium concentration and 3.66 meq L-1 initialnickel concentration. A mathematical model was used to represent the dynamics of biosorption of the metals in a fixed-bed column. The Langmuir multicomponent isotherm model (qm = 2.78 meq g-1, bCr = 0.85 L meq-1, bNi = 0.08 L meq-1 was used to represent the equilibrium data of the column and to simulate the biosorption dynamics of the ions. The simulation results showed that the mathematical model described satisfactory the complex binary biosorption of chromium and nickel in the effluent.

  12. Descripción de la nocividad del cromo proveniente de la industria curtiembre y de las posibles formas de removerlo Description of chrome toxicity from the tannery industry and possible ways of removing it

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    Álvaro Chávez Porras

    2010-07-01

    Full Text Available Los diversos compuestos de cromo (Cr representan una gran amenaza al ambiente y al hombre debido a sus efectos nocivos. Las intoxicaciones se manifiestan en lesiones renales, gastrointestinales, del hígado, del riñón, de la glándula tiroides y la médula ósea, y la velocidad corporal de eliminación es muy lenta. Las industrias de curtiduría de pieles utilizan sales de Cr en sus procesos, que generan cantidades de efluentes líquidos con alto contenido de este metal, el cual, debe ser removido a fin de cumplir con la legislación ambiental. En esta revisión se presenta una descripción de algunas de las técnicas de remoción como la electrolítica o electrodeposición; el intercambio iónico; la precipitación y los sistemas biológicos. Cada una de ellas ofrece una solución práctica y viable en términos económicos, ambientales y de mejoramiento continuo de los procesos, permitiendo pensaren una producción sostenible y responsable.The various chromium (Cr compounds represent a major threat to both environment and human beings, due to its harmful effects. Toxicity is shown in kidney, gastrointestinal tract, liver, thyroid glands, and in the marrow; and body elimination speed is very slow. Tannery industries use Cr salts in their processes, generating large amounts of liquid effluents with high content of this metal; which should be removed in order to comply with existing environmental legislation. This study provides a description of techniques such as electrolytic removal or electroplating, ion exchange process; process of precipitation; and biological systems. Each one of them offers a practical and feasible solution in terms of economy, environment, and continuous improvement of processes, which allows thinking of a sustainable and responsible production.

  13. Caracterización de la región cromosómica 15q11-q13 del genoma humano. Variabilidad genómica en el autismo e identificación de ncRNAs

    OpenAIRE

    Cerrato Rivera, Celia

    2007-01-01

    La tesis doctoral con título "Caracterización de la región cromosómica 15q11-13 del genoma humano. Variabilidad genómica en el autismo e identificación de ncRNAs" se basa en el estudio de la región cromosómica 15q11-q13, centrándonos en los aspectos de la variabilidad genómica y su significado funcional. En la primera parte del estudio buscamos reordenamientos de 15q11-q13 en pacientes con autismo, mediante la genotipación de marcadores microsatélites cubriendo dicha región, y definimos una d...

  14. Alteraciones cromosómicas en Leucemias linfoides agudas; un estudio de nueve años en 632 pacientes: implicaciones en el diagnóstico, pronóstico, tratamiento y seguimiento de la enfermedad

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    G. Guevara

    2001-07-01

    Full Text Available Las leucemias linfoides agudas son las neoplasias más comunes en niños, produciendo todavía alta mortalidad en nuestro medio. En estos tumores se han descrito una amplia variedad de alteraciones cromosómicas que se asocian con el pronóstico, diagnóstico morfológico y que sirven de marcadores para escoger la terapia y seguir la enfermedad. En esta investigación se quizo analizar el tipo y frecuencia de las aberraciones cromosómicas en una población colombiana de niños y adultos con diagnóstico de LLA.

  15. Equilibrios de óxido-reducción. Variación del potencial de un par con el pH. Reacción entre el par dicromato-cromo y yodo-yoduro. Problema interactivo.

    OpenAIRE

    Milla González, Miguel

    2015-01-01

    El potencial redox de los oxoaniones oxidantes varía en función de la concentración de protones del medio. Eso le ocurre al par dicromato-cromo(III). Sin embargo, el potencial del par yodo-yoduro es formalmente independiente del pH. En este ejercicio es necesario calcular el pH para el que la reacción entre ambos pares no va teóricamente en ningún sentido.

  16. Cuantificación de plomo, cadmio y cromo mediante sialoquímica Quantification of lead, cadmium and chromium through sialochemistry

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    MIREYA GONZÁLEZ

    1997-05-01

    Full Text Available Objetivo. Determinar las concentraciones de plomo, cadmio y cromo, y establecer su posible asociación con diferentes factores sociodemográficos. Material y métodos. Se seleccionó una muestra representativa de 100 estudiantes de posgrado de la Facultad de Odontología de la Universidad Nacional Autónoma de México (UNAM, a los cuales se les colectó saliva total no estimulada. Dichas muestras fueron analizadas por espectrofotometría de absorción atómica con horno de grafito. Resultados. Metales pesados como el plomo, el cadmio y el cromo se encuentran en concentraciones mucho más altas que las informadas en la literatura: Pb, = 3.10 m g/dL-1, máxima: 16.8 my g/dL-1, y mínima: 0.04 my g/dL-1; Cd, = 0.25 my g/dL-1, máxima: 2.04 my g/dL-1, y mínima: 0.004 my g/dL-1; y Cr, = 1.43 my g/dL-1, máxima: 4.82 my g/dL-1, y mínima: 0.05 my g/dL-1. Asimismo, variables como la zona de residencia, el sexo, la edad y la ingesta de comida enlatada no influyen en los niveles de plomo y cromo. Sin embargo, en el caso del cadmio y la edad existe una asociación inversa (ji²= 5.9012, pObjective. To determine the concentration of lead (Pb, cadmium (Cd, and chromium (Cr and establish the possible association of these heavy metals with some sociodemographic factors. Material and methods. A representative sample of one hundred dental students from the National Autonomous University of Mexico living in Mexico City participated in this study. Unstimulated human whole saliva samples were analyzed by Atomic Absorption Spectroscopy. Results. Concentrations of Pb, Cd, and Cr were higher than those reported elsewhere: Pb ( or = 3.10 m g/dL-1; Maximum: 16.8 mu g/dL-1 and Minimum: 0.04 mu g/dL-1, Cd ( or = 0.25 mu g/dL-1; Maximum: 2.04 mu g/dL-1 and Minimum: 0.004 mu g/dL-1 and Cr ( or = 1.43 mu g/dL-1; Maximum: 4.82 mu g/dL-1 and Minimum: 0.05 mu g/dL-1. No association was found between the variables studied (age, sex, geographic area and canned food consumption

  17. MINIMIZACIÓN DE RESIDUOS DE CROMO MEDIANTE LA APLICACIÓN DE UNA TÉCNICA DE RECICLADO DIRECTO DE LICORES DE PIQUELADO - CURTIDO EN EL PROCESAMIENTO DE PIELES

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    Ramiro Escalera Vásquez

    2013-07-01

    Full Text Available Uno de los problemas ambientales confrontados por las curtiembres bolivianas es la emisión de residuos líquidos contaminados con cromo, del cual se desechan significativas cantidades en los procesos convencionales. Aunque este versátil metal pesado juega un rol importante en el metabolismo de plantas y animales, en bajas concentraciones, sus derivados oxidados, Cr (VI, son extremadamente tóxicos. Como alternativa de prevención de la contaminación, se ha realizado una investigación en torno a la aplicación del método de Reciclado Directo  de Licores Residuales en la etapa de piquelado - curtido de pieles. Se ha demostrado mediante numerosas corridas experimentales realizadas en laboratorio y en planta, que el reciclaje directo de licores residuales de curtido es técnicamente viable para su implantación en las etapas de piquelado y curtido del proceso de fabricación de cueros al cromo en una curtiembre común. La calidad del cuero terminado no se deteriora con el re-uso directo de los licores de cromo hasta en 10 reciclos. El control del proceso puede realizarse con la medición de parámetros muy simples: La densidad de los licores, la fuerza iónica relacionada con la densidad, el grado de acidez (pH y la concentración de cromo en los licores residuales. Se generan ahorros importantes en el consumo de reactivos químicos, entre el 9% y el 44%, y sobre todo, en consumo de agua, 77%. La mitigación del impacto ambiental producido por el contenido de Cr(III en los licores de curtido, se traduce en una disminución de más de 70% de la masa desechada de Cr(III, cuando se usa el reciclado directo, respecto de la masa que se desecha en curtidos normales sin reciclo. La implementación del reciclado directo de licores de cromo es replicable a otras industrias similares, que existen en gran número en Bolivia.

  18. DESENVOLVIMENTO DE NANOEMULSÕES E NANOCÁPSULAS POLIMÉRICAS CONTENDO TIOCONAZOL E INCORPORAÇÃO EM HIDROGÉIS

    OpenAIRE

    Andréia Pisching Garcia Härter

    2013-01-01

    Este trabalho objetivou o desenvolvimento de nanoemulsões e nanocápsulas poliméricas contendo tioconazol para o tratamento tópico de micoses superficiais. Inicialmente, foi validado um método por cromatografia líquida com detecção UV para quantificação do tioconazol nas formulações nanoestruturadas. O método apresentou-se específico, linear, preciso, exato e robusto. As nanoemulsões e nanocápsulas de PCL contendo o tioconazol (1,0 mg/mL) foram preparadas pelos métodos de emulsificação espontâ...

  19. Desempenho de vacas em lactação alimentadas com dietas contendo torta de macaúba

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    R.A. Azevedo

    2014-02-01

    Full Text Available Avaliaram-se o consumo de nutrientes e a produção e composição do leite de vacas da raça Holandesa alimentadas com dietas contendo diferentes quantidades de inclusão de torta de macaúba. Oito animais foram distribuídos em dois quadrados latinos 4x4, sendo quatro tratamentos, 0, 100, 200 e 300g kg-1 de TM na matéria seca da dieta, e quatro períodos experimentais de 21 dias, 14 de adaptação e sete de avaliações. A adição de quantidades crescentes de torta de macaúba à dieta alterou o consumo de matéria seca, matéria orgânica, proteína bruta, extrato etéreo, fibra em detergente neutro, carboidratos não fibrosos, produção e os teores de lactose, extrato seco desengordurado e sólidos totais do leite, bem como a eficiência alimentar e a digestibilidade da matéria seca. Por outro lado, não foi verificada diferença nos teores de gordura do leite. A adição da TM em até 300g kg-1 da dieta comprometeu o consumo e o desempenho produtivo dos animais.

  20. Verificação da atividade antibacteriana de sabonete líquido contendo extrato glicólico de Dimorphandra mollis Benth.

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    KETYLIN FERNANDA MIGLIATO

    2009-12-01

    Full Text Available Dimorphandra mollis Benth., Compositae, falsobarbatimão, é utilizada topicamente como cicatrizante, adstringente e antimicrobiano. No presente estudo, verificou-se a atividade antibacteriana de sabonete líquido contendo extrato glicólico de D. mollis (EGD em diferentes concentrações (8, 15 e 20% e em diferentes pHs (6 e 8. Foram preparadas cinco formulações (F de sabonete: F1 - triclosan (0,1%, F2 - EGD (8%, F3 - EGD (15%, F4 - EGD (20% e F5 - sem conservante. Cascas de D. mollis foram secas em estufa de ar circulante e pulverizadas. Os extratos brutos foram preparados por turbo-extração utilizando-se etanol. Após filtração, os extratos foram concentrados em evaporador rotatório, liofilizados e ressuspendidos em propilenoglicol para a obtenção do extrato glicólico. A atividade antibacteriana foi verificada pelo método de difusão em ágar, empregando cilindros em placa. Placas contendo Staphylococcus aureus, Pseudomonas aeruginosa e Escherichia coli foram incubadas a 37ºC durante 24 horas. Após incubação, as leituras foram realizadas com paquímetro, observando-se o diâmetro do halo de inibição de crescimento bacteriano. Verificouse que o sabonete líquido contendo triclosan provocou inibição do crescimento bacteriano em ambos os pHs; já os sabonetes sem conservante e contendo EGD, independente da concentração e do pH empregados, não apresentaram atividade antibacteriana. Palavras-chave: Atividade antibacteriana. Sabonete líquido. Dimorphandra mollis Benth.

  1. Fosfato de cromo (III marcado con diferentes radionúclidos para uso en radiosinoviortesis Chromium (III phosphate labelled with several radionuclides for use in radiosynoviothersis

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    Jorge Cruz Arencibia

    2012-06-01

    Full Text Available Introducción: la radiosinoviortesis se utiliza en el tratamiento de la sinovitis crónica, complicación frecuente en enfermedades sistémicas como artritis reumatoide y hemofilia. En la práctica clínica internacional se emplean diferentes coloides y suspensiones radiactivas, pero su número es reducido y su disponibilidad limitada. Objetivo: obtención y caracterización físico-química de suspensiones de fosfato de cromo (III marcadas con radionúclidos como potenciales radiofármacos para uso en radiosinoviortesis. Métodos: las suspensiones se obtuvieron por síntesis química, los radionúclidos se añadieron al inicio de la reacción o después de finalizada esta. El tamaño de partículas se estimó mediante microscopia óptica y filtración por membranas. Asimismo se evaluó por espectrofotometría la estabilidad de la suspensión al ser resuspendida en distintos medios. La pureza radioquímica se determinó por cromatografía de papel. Resultados: se obtuvo y caracterizó una suspensión de fosfato de cromo (III. El producto obtenido presentó un tamaño de partículas predominante entre 0,8-5 µm y que al ser suspendidas en solución de gelatina al 2 % en tampón acetato 1 mg/mL no sedimentó en menos de 3 h. Se estableció la tecnología para la obtención de formulaciones de fosfato de cromo (III marcado con 32P e 90Y y se demostró la factibilidad de marcar la suspensión obtenida con otros radionúclidos trivalentes como 177Lu y 68Ga. Conclusiones: los resultados permiten considerar al fosfato de cromo (III una suspensión base para la obtención de radiofármacos para uso en radiosinoviortesis en diferentes articulaciones, en función de las características físico-nucleares de los radionúclidos que se empleen.Introduction: radiosynoviorthesis is used in treating chronic synovitis, a frequent complication of some systemic diseases as rheumatoid arthritis and hemophilia. There are different colloids and radioactive

  2. El cromo (VI Induce la frecuencia de mutación y pérdida de Heterocigocidad En Saccharomyces cerevisiae

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    Gustavo Santoyo

    2018-01-01

    Full Text Available El cromo (Cr es uno de los principales contaminantes en desechos industriales, asociado con diversos daños a la saludhumana, motivo por el que en este trabajo analizamos el efecto del Cr hexavalente sobre la frecuencia de mutaciónespontánea (utilizando el gen reporteroCAN1 y la pérdida de heterocigocidad en la levaduraSaccharomycescerevisiae. Se comparó su efecto en una mutante en el genrev3, que codifica para la polimerasa zeta. Los resultadossugieren que el Cr(VI puede inducir la frecuencia de mutación entre 20 y 28 veces, a concentraciones de 25 y 50mM, respectivamente eincrementarse en una mutanterev3y aunque no se observaron los mismos niveles como enla cepa silvestre, esto sugiere que, además derev3, existen otros factores que inducen la aparición de mutacionesen el marcador empleado. El Cr también tuvo un efecto al aumentar la pérdida de heterocigocidad de entre 50 y57 veces en la cepa silvestre y la mutanterev3, respectivamente. Estos resultados muestran queREV3participa en elefecto mutagénico causado por el Cr(VI, pero no en la pérdida de heterocigocidad, en las células de la levadura.

  3. Disgenesia gonadal mixta como forma de presentación de un desorden de la diferenciación sexual de causa cromosómica

    Directory of Open Access Journals (Sweden)

    María del Carmen Valdés Alonso

    Full Text Available La diferenciación sexual es un proceso genéticamente determinado y controlado, que puede ser alterado por diferentes tipos de mutaciones genéticas, o por el efecto de hormonas u otros disruptores ambientales que actúan sobre el embrión, resultando en la formación de genitales externos que no se corresponden con el sexo genético y con los genitales internos. La disgenesia gonadal mixta clasifica en los desórdenes de la diferenciación sexual de causa cromosómica. Se describe un paciente de un año de edad que es atendido en el Hospital Pediátrico “Juan Manuel Márquez”, por presentar genitales externos atípicos. El diagnóstico del paciente fue de disgenesia gonadal mixta, y se realizó con los complementarios siguientes: ecografía ginecológica, estudios hormonales y cariotipo. El tratamiento instaurado inicialmente, fue quirúrgico en dos tiempos operatorios, y el seguimiento hormonal hasta la pubertad (14 años, cuando se inició terapia de reemplazo hormonal según lo establecido por la edad de la paciente.

  4. Dietas para frangos de corte contendo quirera de arroz Performance of broiler feed with broken rice in diets

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    Berilo de Souza Brum Júnior

    2007-10-01

    Full Text Available O experimento foi realizado para avaliar o uso da quirera de arroz na dieta de frangos de corte. Foram utilizados 240 pintos machos, alojados em galpão, contendo 12 boxes de 2m² de área. Cada box continha comedouro tubular, bebedouro pendular e campânula nos 21 dias iniciais. As aves foram distribuídas em um delineamento inteiramente casualizado, com três tratamentos e quatro repetições, as quais receberam dietas contendo 0, 20 e 40% de inclusão de quirera de arroz. Os dados foram submetidos à análise de regressão e à análise de variância e, quando houve diferença, aplicou-se o teste de Tukey. O ganho de peso, o consumo de ração e a conversão alimentar de 1-21, 1-35 e 1-42 dias (P>0,05 não foram afetados pela substituição do milho por quirera de arroz. A umidade de cama, o índice de eficiência produtivo, o rendimento de carcaça quente, de fígado, coração, coxa, sobre-coxa e peito não apresentaram diferença (P>0,05. No entanto, os rendimentos de moela, bem como a pigmentação da canela e do bico, diminuíram linearmente com o aumento do nível de quirera de arroz na dieta. Conclui-se que a quirera de arroz pode ser incluída nas dieta, substituindo o milho, para frangos de corte.An experiment was carried to evaluate the performance of broilers fed with diferent levels of broken rice. The experiment was conducted with 240 males broilers chicks, Cobb 500, were distributed in floor pens of 2m² each, with one tubular feeder, one pendular drinker, an electrical brooder and on the top of rice hulls. An entirely randomized experimental design was used, with 3 treatments and 4 replicates with 20 birds each, which received, diets containing 0, 20 and 40% of broken rice. Data were submitted to Analisis of regression. Weight gain, feed intake, feed conversion to the1- 21, 1- 35 and 1-42 days of age, litter humidity, carcass, liver, breast, thigh and drumstick yield did not present significant difference. The gizzard and the

  5. Adsorção de cromo (VI por carvão ativado granular de soluções diluídas utilizando um sistema batelada sob pH controlado Chromium (VI adsorption by GAC from diluted solutions in batch system and controlled ph

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    Renata Santos Souza

    2009-09-01

    Full Text Available Na Amazônia o cromo é empregado principalmente na indústria de couro e de madeira, sendo responsável por vários problemas de saúde porque é tóxico para os seres vivos. A remoção de cromo de efluentes industriais é feita por meio de diversos processos como a adsorção. Este trabalho mostra os resultados da adsorção de Cr(VI por carvão ativado granular comercial (CAG como adsorvente de soluções diluídas empregando um sistema de adsorção batelada com controle de pH. Os grupos funcionais da superfície do CAG foram determinados pelo método de Boehm. Além disso, o efeito do pH na adsorção de Cr(VI, o equilíbrio e a cinética de adsorção foram estudados nas condições experimentais (pH = 6, MA = 6g, tempo de adsorção 90min.. Na superfície do CAG, os grupos carboxílicos foram determinados em maior concentração (MAS=0,43 mmol/gCAG, estes, presentes em concentrações elevadas aumentam a adsorção do metal, principalmente em valores de pH ácidos. A capacidade de adsorção é dependente do pH da solução, devido a sua influência nas propriedades de superfície do CAG e nas diferentes formas iônicas das soluções de Cr(VI. Os dados de equilíbrio da adsorção foram ajustados satisfatoriamente pela isoterma de Langmuir (R²=0,988, tipo favorável. A partir da cinética de adsorção a 5mg/L e 20mg/L, os resultados obtidos foram compatíveis com o valor limite preconizado na legislação nacional (Res. nº 357/05. Portanto, para o sistema experimental utilizando CAG foi eficiente na remoção de Cr(VI a partir de correntes líquidas contendo baixas concentrações do metal.In Amazonia, chromium is mainly used in the leather and wood industries. It is responsible for many health problems, because of its toxicity. These industries remove chromium waste by various processes, such as adsorption. This work shows the results of Cr(VI adsorption by commercial granular activated carbon (GAC as adsorbent from diluted

  6. Ion nitriding post-oxidation as an alternative technique to electrolytic chromium; Nitruracion post-oxidacion ionica como tecnica alternativa al cromado electrolitico

    Energy Technology Data Exchange (ETDEWEB)

    Diaz-Guillen, J. C.; Granda-Gutierrez, E.E.; Campa-Castilla, A.; Perez-Aguilar, S.I.; Garza-Gomez, A.; Candelas-Ramirez, J.; Mendez-Mendez, R. [COMIMSA. Corporacion Mexicana de Investigacion en Materiales S.A. de C.V., Saltillo, Coahuila (Mexico)]. E-mail: jcarlos@comimsa.com

    2010-11-15

    The effect of temperature and processing time during post-oxidation on hardness and corrosion resistance of AISI 1045 samples treated through nitriding and post-oxidation in a pulsed plasma discharge is evaluated in this paper. Also, a comparative analysis of the mechanical properties obtained with the dual nitriding - post oxidation process versus those properties of typical hard chrome coatings was performed with an aim to propose an alternative technique to the processes of galvanic coatings. The latter revealed that the process of ion nitriding and post-oxidation provides similar properties in hardness and improves the corrosion resistance compared to the hard chrome case. It is conclude that the technique of ion nitriding and post-oxidation is a non environmental harmful technology with strong potential to replace highly polluting electroplating techniques for application of hard chrome coatings. [Spanish] En el presente trabajo se evalua el efecto del tiempo y la temperatura de post-oxidacion sobre las propiedades de dureza y resistencia a la corrosion de muestras de acero AISI 1045 sometido al proceso de nitruracion post-oxidacion ionica en plasmas pulsados. Asi mismo, con el objetivo de fundamentar la propuesta de utilizacion de la nitruracion post-oxidacion ionica como una tecnica alternativa a los procesos galvanicos para aplicacion de recubrimientos de cromo duro, se realizo un analisis comparativo de propiedades, evidenciando que, mediante el proceso nitruracion postoxidacion ionica, es posible obtener caracteristicas similares en dureza y mejores en resistencia a la corrosion que las tipicas obtenidas para el cromo duro. Los resultados obtenidos permiten postular una tecnica que no dana al medio ambiente, como lo es la nitruracion post-oxidacion ionica, como candidata potencial para sustituir las tecnicas galvanicas altamente contaminantes para aplicacion de cromo duro.

  7. Frecuencia de aberraciones cromosómicas en sujetos con gonosomopatías: Experiencia en 19 años de trabajo Frequency of chromosomal aberrations in subjects with gonosomopathies: Experience in 19 years of work

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    Marlén Quesada Dorta

    2004-08-01

    Full Text Available El objetivo de este trabajo fue determinar la frecuencia de aberraciones cromosómicas en un grupo de pacientes portadores de gonosomopatías y relacionar en cada caso el significado de las diferentes aberraciones cromosómicas encontradas con el diagnóstico clínico realizado. Se estudiaron desde el punto de vista citogenético 656 pacientes con diagnóstico presuntivo de gonosomopatías, recibidos en el laboratorio de genética molecular del Hospital Clinicoquirúrgico "Hermanos Ameijeiras" entre los años 1982 y 2001, procedentes de distintas instituciones hospitalarias del país. Del total de pacientes con diagnóstico presuntivo de gonosomopatías, en el 32,7 % (215/656 se confirmó el diagnóstico clínico con el estudio citogenético. El estudio cromosómico se realizó por técnicas de bandas G. Los reordenamientos cromosómicos encontrados se clasificaron en 4 grupos; el de mayor frecuencia fue el de las gonosomopatías numéricas, con 110 pacientes que representan el 51 % del total. En orden de frecuencia siguieron el grupo de las alteraciones numéricas y estructurales (mosaicos con 59 pacientes (27,0, las inversiones de sexo con 24 (12,0 y el grupo de las gonosomopatías estructurales con 22 (10,0. Las aberraciones cromosómicas más comunes fueron las gonosomopatías numéricas (síndromes de Turner y Klinefelter. El estudio cromosómico en estos pacientes constituye un indicador de valor diagnóstico de gran importancia para la conducta terapéutica a seguir en cada caso.This paper was aimed at determining the frequency of chromosomal aberrations in a group of patients carriers of gonosomopathies and at relating in each case the meaning of the different chromosomal aberrations found to the patients' clinical diagnosis. 656 patients with presumptive diagnosis of gonosomopathies from different hospital institutions of the country that were received at the mollecular genetics laboratory of "Hermanos Ameijeiras" Clinical and Surgical

  8. Caracterización Fitoquímica y Efecto Hipoglucemiante de Tecoma stans y su Relación con la Presencia del Cromo como Factor de Tolerancia a la Glucosa Phytochemical Characterization and Hypoglycemic Effect of the Tecoma stans and its Relationship to the Presence of Chromium as a Factor for Glucose Tolerance

    OpenAIRE

    Ma. de J Ibarra; Pedro C Cantú; María J Verde; Azucena Oranday

    2009-01-01

    Se realizó la caracterización fitoquímica y la determinación del cromo en hojas de Tecoma stans, observando su efecto hipoglucemiante en animales con diabetes mellitus inducida en forma experimental. Como hiperglucemiante se utilizó estreptozotocina en ratas machos Sprague-Dawley a una dosis de 45 mg/kg de peso. Los tratamientos experimentales, todos por vía oral, fueron los siguientes para grupos diabéticos y grupos no diabéticos: agua, infusión de la planta, picolinato de cromo, e infusión ...

  9. Estudo dos mecanismos de detoxificação e tolerância aos metais cromo e cobre em Pseudokirchneriella subcapitata e Pistia stratiotes e o uso das macrófitas Typha sp e Phragmites sp na remoção de nutrientes em wetlands construídos

    OpenAIRE

    Patrícia Carla Giloni de Lima

    2010-01-01

    A presente pesquisa teve por objetivos principais: (1) estudar a bioacumulação do metal cromo (40-50 \\'mü\\'g/L) na Clorophyceae Pseudokirchneriella subcapitata (Korshikov) Hindak 1990 e dos metais cobre (2-10 \\'mü\\'g/L) e cromo (1-6 mg/L) na macrófita Pistia stratiotes L.; (2) avaliar os mecanismos de detoxificação, as estratégias de defesa e tolerância de Pistia stratiotes L., visando recomendar seu uso na fitorremediação; ambos através do uso do Delineamento Composto Central (DCC) e Metodol...

  10. DESARROLLO Y VALIDACIÓN DE UN MÉTODO ESPECTROFOTOMÉTRICO/COLORIMÉTRICO PARA LA DETERMINACIÓN DE CROMO (III EN LICORES RESIDUALES DE PIQUELADO-CURTIDO

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    Ramiro Escalera Vásquez

    2007-01-01

    Full Text Available Dos métodos no destructivos fueron desarrollados y validados para la determinación de concentraciones de sales de cromo en licores residuales de curtido que se producen en la fabricación de cueros: Un método espectrofotométrico y un método colorimétrico derivado. Los dos métodos se basan en el análisis de espectros de absorbancia-longitud de onda generados por soluciones patrón que fueron preparadas con los mismos reactivos químicos comerciales utilizados por una curtiembre local, en el intervalo de longitud de onda de 190-800 nm (UV-visible. Ambos métodos satisfacen los criterios fundamentales de validación: proporcionalidad (buena linealidad y buena sensibilidad dentro del intervalo de concentraciones de sales de cromo que se observa en los licores residuales de curtido; precisión (buena repetibilidad/reproducibilidad; exactitud (sin diferencias estadísticas respecto a métodos oficiales y selectividad (buena especificidad para la sal de cromo. Estos métodos son prácticos por su simplicidad, bajo costo y rapidez. Requieren equipos de bajo costo (un espectrofotómetro de rango visible o un colorímetro fabricado manualmente, usan los mismos reactivos químicos que se aplican en procesos de curtido corriente y no requieren de condiciones de seguridad especiales ni personal especializado. Los métodos pueden ser utilizados para el control de reciclado directo de licores de curtido-piquelado, facilitando de esta manera la adopción de esta técnica de Producción Más Limpia por parte de los fabricantes de cueros, especialmente curtiembres de escala pequeña y mediana.

  11. Evaluación genotóxica del extracto oleoso de la semilla de Carapa guianensis Aublet en el ensayo de aberraciones cromosómicas en ratones Balb/c

    Directory of Open Access Journals (Sweden)

    Daniel Francisco Arencibia Arrebola

    Full Text Available Introducción: el extracto oleoso de la semilla de Carapa guianensis Aublet ha tenido diversos usos biomédicos. Recientemente fue evaluado este extracto, el cual manifestó grandes potencialidades como antioxidante en ensayos in vivo; pero poco se conoce de su efecto sobre el ADN en biomodelos experimentales. Objetivo: evaluar el potencial genotóxico del extracto oleoso de la semilla de Carapa guianensis en el ensayo de aberraciones cromosómicas de células de la médula ósea de ratones Balb/c. Métodos: se formaron cinco grupos experimentales: un grupo placebo (Tween 65 al 2 %, tres tratados con niveles de dosis del extracto (400, 1 000 y 2 000 mg/kg, administrados por vía oral durante 14 días; por último, un grupo control positivo tratado con ciclofosfamida, en dosis de 50 mg/kg por vía intraperitoneal 48 y 24 h antes de la eutanasia. Se administraron cinco animales/sexo/grupo. Después de los 14 días de administración se les efectuó la eutanasia por dislocación cervical y se les extrajo la médula ósea del fémur para proceder a realizar la técnica citogenética de aberraciones cromosómicas. Resultados: los resultados entre controles y tratados con el extracto no difirieron para los dos sexos en las variables índice mitótico, Gaps, células con poliploidías, número de células con aberraciones cromosómicas y cromatídicas y el porcentaje de células con aberraciones. Sin embargo, sí difirieron controles y tratados contra el grupo tratado con ciclofosfamida, lo que valida nuestros resultados. Conclusiones: el extracto oleoso de la semilla de la Carapa guianensis no posee potencialidades genotóxicas en la formación de aberraciones cromosómicas, sobre todo estructurales en células de la médula ósea de ratones Balb/c de ambos sexos.

  12. EVALUACIÓN Y REGULACIÓN DE PARÁMETROS EN UN EQUIPO DISEÑADO PARA LA DISMINUCIÓN DE CROMO(VI), PROVENIENTES DE LA INDUSTRIA DE RECUBRIMIENTOS GALVÁNICOS

    OpenAIRE

    Acosta Niño, Gema Eunice; Bourdón García, Alejandro; Coy Barrera, Carlos Andrés

    2013-01-01

    RESUMEN Con el fin de generar los medios necesarios para poder llevar a cabo las pruebas de remoción de cromo(VI) en aguas residuales de la industria galvánica, se realizó la captura de datos a partir de prototipo de equipo inicial a escala de laboratorio para conseguir el objetivo principal, disminuir la cantidad de metales en aguas residuales contaminadas con diferentes metales. Es así que con los datos obtenidos en el presente estudio se plantearon algunas modificaciones necesarias para me...

  13. EVALUACIÓN Y REGULACIÓN DE PARÁMETROS EN UN EQUIPO DISEÑADO PARA LA DISMINUCIÓN DE CROMO(VI), PROVENIENTES DE LA INDUSTRIA DE RECUBRIMIENTOS GALVÁNICOS

    OpenAIRE

    Gema Eunice Acosta Niño; Alejandro Bourdón García; Carlos Andrés Coy Barrera

    2013-01-01

    Con el fin de generar los medios necesarios para poder llevar a cabo las pruebas de remoción de cromo(VI) en aguas residuales de la industria galvánica, se realizó la captura de datos a partir de prototipo de equipo inicial a escala de laboratorio para conseguir el objetivo principal, disminuir la cantidad de metales en aguas residuales contaminadas con diferentes metales. Es así que con los datos obtenidos en el presente estudio se plantearon algunas modificaciones necesarias para mejorar la...

  14. Utilización de ceniza volante y catalizador fcc gastado en la recuperación de cromo (iii) de los efluentes líquidos de las curtiembres

    OpenAIRE

    Amaya, Jeceny; Tristancho, Andrés; Sánchez Castellanos, Francisco José

    2010-01-01

    El presente trabajo estudia la posibilidad de utilizar dos desechos sólidos industriales: la ceniza volante de TERMOPAIPA y el catalizador de equilibrio gastado (FCC) de ECOPETROL, en la remoción y recuperación de cromo de los efluentes líquidos de las curtiembres. La ceniza volante se sometió a dos tratamientos hidrotérmicos alcalinos para obtener estructuras zeolíticas de mejores propiedades, y el catalizador gastado se calcinó para eliminar el coque de su superficie. La caracterización de ...

  15. Cinética de la biosorción de cromo hexavalente en solución acuosa por biomasa de Hueso de Prunus Pérsica (Durazno)

    OpenAIRE

    Flores Rodríguez, Wilber Hugo

    2014-01-01

    El cromo hexavalente (Cr +6) representa un riesgo para el equilibrio ambiental y la salud humana, los métodos convencionales para remover metales pesados presentes en efluentes industriales generalmente son costoso e/o ineficientes. La biosorción es una alternativa novedosa, eficiente y económica para resolver este problema ya que es posible emplear subproductos de bajo costo y alta capacidad de remoción; El objetivo de este trabajo fue determinar las propiedades físico-químicas del hueso de ...

  16. A new method in estimation of total hexavalent chromium in Portland pozzolan cement; Un nuevo método en la determinación del cromo hexavalente total en cemento Portland puzolánico.

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, R.; Sharma, D.

    2017-07-01

    Variamine blue was used first time for the detection of hexavalent chromium from cement samples. In present method, cement was treated sequentially with water, sulphate and carbonate buffer to extract soluble, sparingly soluble and insoluble hexavalent chromium respectively. Extracted Cr (VI) was determined using variamine blue as chromogenic reagent. The determination is based on the reaction of hexavalent chromium with potassium iodide in an acid medium to liberate iodine. This oxidizes variamine blue to form a violet coloured species having an absorption to maximum at 556 nm. Energy-dispersive X-ray spectroscopy (EDX) and Infrared Spectroscopy (IR) confirmed the complete extraction of hexavalent chromium by sequential extraction process. SRM 2701 (Reference material from NIST, USA) was used for revalidating the results. The percentage of recovery for proposed and reference method (diphelycarbazide method) varied from 98.5 to 101 and 97.5 to 100.5. Whereas, their relative error percentage varied from -1.5 to 0.33 and -2.5 to 0.5. [Spanish] El azul de variamina se utilizó por primera vez para la detección de cromo hexavalente en muestras de cemento. En el presente método, el cemento se trató secuencialmente con agua, y tampones sulfato y carbonato para extraer el cromo hexavalente soluble, poco soluble e insoluble, respectivamente. El Cr (VI) extraído se determinó utilizando azul de variamina como reactivo cromógeno, por reacción del cromo hexavalente con yoduro de potasio en un medio ácido para liberar yodo. Esto oxida al azul de variamina para formar una especie de color violeta con una absorción máxima a 556 nm. El análisis por energía dispersiva de rayos X (EDX) y la espectroscopía de infrarrojos (IR) confirmaron la extracción completa de cromo hexavalente mediante el proceso de extracción secuencial. Se utilizó SRM 2701 (material de referencia de NIST, EE.UU.) para validar los resultados. El porcentaje de recuperación para el m

  17. Histologia do fígado de tilápia do Nilo ( Oreochromis niloticus alimentados com dietas contendo silagem biológica de pescado

    Directory of Open Access Journals (Sweden)

    Claucia A. Honorato

    2014-12-01

    Full Text Available Resumo: Este estudo teve como objetivo avaliar as possíveis alterações histopatológicas hepática de tilápias do Nilo alimentadas com dietas contendo silagem biológica de pescado com diferentes concentrações protéicas. Foram utilizados 180 juvenis alimentados com dietas contendo três níveis de proteína (20, 24 and 28% PB, e duas proporções de silagem biológica (¼ e ½ durante 75 dias. Os fragementos de fígado foram fixados em Bouin e inclusos em Histosec®. Posteriorente foram cortados em microtomo com espessura de 2 a 5μm. O método utilizado para coloração foi hematoxilina/eosina e PAS. Os cortes histológicos foram analisados em microscopio de luz. O desarranjo na morfologia do fígado dos peixes alimentados com silagem biológica foi influenciado pelos altos níveis protéicos, e pelo aumento ½ de proporções de proteínas de origem animal das dietas. Foi observado que a variação dos hepatócitos está diretamente ligada com o tipo da dieta fornecida para os peixes. Nos peixes alimentados com as dietas contendo 28% PB, o fígado apresentou desarranjo da estrutura cordonal dos hepatócitos, pontos de necrose e deslocamento do núcleo para periferia. Níveis elevados de silagem biológica de pescado provoca alterações deletérias no fígado. O nível de proteína adequado para manter o desenvolvimento associado à saúde do peixe é de 24%PB.

  18. Extracción de cromo con disolventes orgánicos. III parte. Aplicación al tratamiento de residuos polimetálicos industriales

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    de Juan, D.

    1998-10-01

    Full Text Available The use of Primene 81R as extraction agent of chromium present in solid wastes containing nickel, iron and copper has been studied. The waste was leached with a sulphuric acid solution up to pH 3 and oxidation of Cr(III to Cr(VI with Caro acid was also studied. Because of the negative result of oxidation, the treatment was applied on Cr(III directly. Extraction/scrubbing/stripping process was studied in the leach. The composition of organic phase used in the extraction step was 10 % v/v Primene 81R, 10 % isodecanol and kerosene. All the iron, 91 % Cr, 10 % Ni and large part of the copper contained in the initial leach solution are recovered in the organic phase. In the scrubbing stage (with a sulphuric acid solution at pH 1,4, all the copper and nickel and 30 % Cr go to the washing liquor, while all the iron and 70 % Cr remained in the organic phase. In the stripping stage (with a 2N NH4OH or 2N NaOH solution all the iron and chromium are recovered as a precipitate of highly absorbent hydroxides. After the treatment mentioned, 63 % Cr and 100 % Fe are recovered as a mixture of hydroxides, and 28 % of the initial chromium, all the nickel and the copper are found in the washing liquor.

    Se estudia la aplicación del Primene 81R como agente de extracción del cromo presente en residuos sólidos que poseen níquel, hierro y cobre. El residuo se lixivió con disolución de ácido sulfúrico hasta pH 3 y se investigó la oxidación del Cr(III a Cr(VI con ácido de Caro. Ante el nulo resultado en la oxidación, se actuó directamente sobre el Cr(III. Se estudió el proceso de extracción/lavado/reextracción sobre la lejía de lixiviación. La fase orgánica empleada en la extracción estaba constituida por 10 % v/v de Primene 81R, 10 % de isodecanol y queroseno. En la fase orgánica se recupera todo el hierro, el 91 % Cr, el 10 % Ni y gran parte del cobre contenidos en la lejía de partida. En la etapa de lavado (con disolución de

  19. Desenvolvimento de material de referência para microbiologia de alimentos contendo Listeria monocytogenes em matriz queijo

    Directory of Open Access Journals (Sweden)

    Marcelo Luiz Lima Brandão

    2013-10-01

    Full Text Available A NBR ISO/IEC 17025:2005, uma das normas mais utilizadas em laboratórios de ensaio, descreve como um de seus critérios para a garantia da qualidade dos resultados analíticos a participação periódica dos laboratórios em ensaios de proficiência (EP. Os analitos, utilizados nos EP são materiais de referência (MR provenientes de um mesmo lote, e devem apresentar características de homogeneidade e estabilidade. O objetivo deste estudo foi produzir um MR qualitativo destinado ao ensaio de pesquisa de Listeria monocytogenes em matriz queijo pela técnica de liofilização. Para a produção do MR, foi utilizado como matriz o queijo Minas frescal (QMF ultrafiltrado. A matriz foi distribuída em frascos, contaminada com a bactéria alvo e submetida à liofilização, tendo a sacarose como crioprotetor. O MR produzido foi considerado homogêneo e estável na temperatura de ≤-70°C durante todo o período estudado (10 meses. O material apresentou estabilidade a 4, 25, 30 e 35°C por quatro dias e a -20°C por 48 dias, e os resultados estatísticos indicam tendência à estabilidade. Conclui-se que o material apresentou todos os requisitos necessários de um MR de qualidade e poderia ser transportado aos laboratórios participantes de um EP à temperatura máxima de 35°C por até quatro dias, uma vez que os resultados indicaram a manutenção da concentração celular nesse período. Esse foi o primeiro trabalho a descrever uma metodologia de produção de MR contendo L. monocytogenes em matriz queijo.

  20. Nota científica: perfil bioquímico de ratos alimentados com iogurte contendo extrato de erva-mate (Ilex paraguariensis St. Hil)

    OpenAIRE

    Ril,Franciele Taís; Loch,Camila Ronsoni; Valduga,Alice Teresa; Macedo,Sandra Manoela Dias; Cichoski,Alexandre José

    2011-01-01

    Este estudo teve como objetivo avaliar o efeito do iogurte contendo extrato de erva-mate (Ilex paraguariensis) e com/sem culturas probióticas sobre o perfil lipídico, glicêmico, hepático e renal de ratos alimentados com esses tipos de iogurtes. Ratos da linhagem Wistar (42) foram divididos em três grupos (n=14), e receberam iogurte sem extrato de erva-mate, iogurte com extrato de erva-mate 0,1% e iogurte com extrato de erva-mate 0,1% e culturas probióticas, durante 30 dias. Não foi observado ...

  1. Análise exploratória aplicada no estudo de medicamentos contendo piroxicam Exploratory analysis applied in study of pharmaceutical formulations with piroxicam

    Directory of Open Access Journals (Sweden)

    Graciele Parisotto

    2005-12-01

    Full Text Available A identificação de diferentes formulações de medicamentos manipulados contendo piroxicam foi estudada, empregando espectros de reflexão difusa no infravermelho médio com transformada de Fourier (DRIFTS, em associação com a técnica de análise por agrupamentos hierárquicos (AAH. Os espectros de amostras, de 5 diferentes farmácias de manipulação, contendo piroxicam (10 mg e 20 mg e seus respectivos excipientes, foram adquiridos em um espectrofotômetro NICOLET Magna 550, obtendo-se duas réplicas de cada amostra. Para a análise multivariada, as informações espectrais foram tratadas no programa Pirouette® 2.7 da Infometrix, utilizando-se as regiões espectrais 1340 a 1470 cm-1, 1535 a 1680 cm-1, 2800 a 3004 cm-1 e 3290 a 3400 cm-1. Os dendogramas foram construídos com os dados auto-escalados, e correção do espalhamento da luz (MSC, utilizando três tipos de construção: simples, flexível e incremental. Com a aplicação da análise hierárquica de agrupamentos constatou-se a formação de dois grupos distintos, um contendo os princípios ativos, e outro contendo os excipientes. Os resultados demonstram que a técnica DRIFTS em conjunto com análise por agrupamentos hierárquicos constitui uma alternativa para o controle de qualidade dos processos de produção de medicamentos.The identification of different pharmaceutical formulations with piroxicam was studied, using spectra of diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS, in association with hierarchical cluster analysis (HCA technique. The spectra of samples of the 5 different compounding pharmacies, containing 10 or 20 mg of piroxicam and its respective inactive ingredients, had been collected in Nicolet Magna 550 spectrophotometer. For the multivariate analysis, the spectral information had been processed in software package Pirouette® 2.7 of the Infometrix. The dendograms had been constructed with the autoscaled data, and multiplicative scatter

  2. EVALUACIÓN DE LA CINÉTICA DE LA ACUMULACIÓN DE CROMO EN EL BUCHÓN DE AGUA (Eichhornia crassipes AVALIAÇÃO DA CINÉTICA DE ACUMULAÇÃO DE CROMO EM JACINTO DE AGUA (Eichhornia crassipes EVALUATION OF THE KINETICS OF ACCUMULATION OF CHROMIUM IN WATER HYACINTH (Eichhornia crassipes

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    RICARDO BENÍTEZ

    2011-12-01

    Full Text Available Eichhornia crassipes es una planta de rápido crecimiento distribuida en casi todos los países tropicales, que puede tolerar condiciones de contaminación por metales o por eutrificación de cuerpos de aguas lénticos y lóticos. Esta planta se ha convertido en un problema ambiental; no obstante, ha despertado interés en el tratamiento de la contaminación por metales en suelos agrarios y cuerpos de agua. La toxicidad de los metales es un serio inconveniente en esta motivación, ya que influye en la capacidad de acumulación y la transmisión en la cadena trófica. En esta investigación se evaluó el comportamiento de las tasas de acumulación de cromo en la macrófita acuática Eichhornia crassipes, a concentraciones de 30, 60 y 90 mg/L, utilizando un diseño experimental aleatorio, con control y tres repeticiones por nivel. Los estudios llevados a cabo en acuarios de vidrio, evidenciaron sitios de acumulación de cromo en la planta, estableciéndose la cinética de acumulación.Eichhornia crassipes é uma planta de rápido crescimento distribuídas em quase todos os países tropicais, que podem tolerar condições de contaminação por metáis ou de eutrofização das massas de águas lênticos e lóticos. Essa planta tornou-se um problema ambiental, no entanto, despertou o interesse no tratamento da poluição por metais em solos agrícolas e corpos d'água. A toxicidade dos metais é um problema serio com esse raciocínio, uma vez que afeta a capacidade de armazenamento e transmissão na cadeia alimentar. Neste estudo avaliou o comportamento das taxas de acúmulo de cromo em macrófitas aquáticas Eichhornia crassipes, em concentrações de 30, 60 e 90 mg/L, utilizando um delineamento inteiramente casualizado, com controle e três repetições por nível. Estudos realizados em aquários de vidro, apresentaram sítios de acumulação de crómio na planta, que institui a cinética de acumulação.Eichhornia crassipes is a fast growing plant

  3. Influência do cromo no desempenho, na qualidade da carne e no teor de lipídeos no plasma sanguíneo de frangos de corte Chromium influence on performance, meat quality and concentration of lipids in broiler blood plasma

    Directory of Open Access Journals (Sweden)

    Luciana Maria Garcia de Souza

    2010-04-01

    Full Text Available Avaliou-se o efeito da suplementação de cromo na dieta sobre o desempenho, o rendimento de carcaça, a qualidade da carne, o teor de colesterol no peito e os parâmetros bioquímicos do sangue de frangos de corte. O delineamento experimental utilizado foi o inteiramente casualizado, com cinco níveis de tripicolinato de cromo (0, 150, 300, 450 e 600 µg/kg de cromo e seis repetições de 50 aves por unidade experimental. A utilização do tripicolinato de cromo não teve efeito no desempenho dos frangos de corte. Os níveis de cromo não influenciaram o rendimento de carcaça nem o pH do peito dos frangos aos 42 dias de idade. Em avaliação da composição de matéria seca, proteína bruta e extrato etéreo da carne de peito, apenas a porcentagem de extrato etéreo foi influenciada, e de forma quadrática, pelos níveis de cromo na dieta. O nível de 218,2 µg de cromo diminuiu a porcentagem de extrato etéreo em 7,03 em comparação à ausência de cromo. A suplementação de cromo nas dietas não influenciou o teor de colesterol total na carne do peito, mas alterou os níveis de HDL aos 14 dias de idade e os de VLDL e os triglicérides aos 21 dias de idade. A suplementação dietética de cromo não influenciou o desempenho e rendimento de carcaça. Níveis entre 218,2 e 360,3 ìg de cromo interferem no teor de gordura da carne e nos níveis de lipídeos do sangue dos frangos de corte.The aim of this work was to evaluate the effect of dietary chromium supplementation on performance, carcass yield, meat quality, cholesterol level on the breast and blood biochemical parameters on broilers. It was used a complete randomized experimental design with five levels of chromium tripicolinate (0, 150, 300, 450 and 600 µg/kg of chromium and six replicates with 50 broilers per experimental unit. The use of chromium tripicolinate had no effect on the performance of broilers. The levels of chromium did not change the carcass yield neither the breast p

  4. Desempenho e resposta metabólica de bezerros recebendo dietas suplementadas com cromo Performance and metabolic response of calves fed diets supplemented with chromium

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    Marcus Antonio Zanetti

    2003-12-01

    Full Text Available Quatorze bezerros com quatro meses de idade, foram distribuídos em dois tratamentos, sendo um controle e um com suplementação de 0,4 mg de cromo orgânico por kg/M.S de ração basal. A ração basal foi constituída de 52% de feno de coastcross e 48% de concentrado à base de fubá de milho e soja extrusada, e foi oferecida ao animais durante 98 dias. Foi efetuado o controle diário da ingestão de alimentos. Na última semana foi realizado um teste de tolerância à glicose, com os animais em condições de conforto térmico. Para os grupos controle e tratado , o ganho em peso (1,330 e 1,320 kg/dia, a eficiência alimentar (0,24 e 0,25 kg e a conversão alimentar (4,13 e 4,07 kg, foram semelhantes. Apesar de o grupo tratado apresentar tendência de eliminar a glicose mais rapidamente, os grupos não diferiram entre si.Fourteen dairy calves, four months of age were allocated in two treatments: control and supplemented with 0,4 ppm of Cr in the basal diet, which had 52% of grass hay and 48% of concentrate (corn meal and extruded soybeans during 98 days. Feed intake was measured daily. In the last week were performed a glucose tolerance test. Performance were not affected by treatment (liveweight gain 1.330 and 1.320 kg/d; feed efficiency 0.24 and 0.25 and feed conversion, 4.13 and 4.07 for control and treated groups respectively. Chromium tended to decrease the blood glucose, but there were no statistical differences.

  5. Estudio del comportamiento de los recargues multicapas de depósitos soldados de fundición blanca al cromo

    Directory of Open Access Journals (Sweden)

    R. Collazo-Carceller

    2009-05-01

    Full Text Available Se determina la influencia de los parámetros Energía introducida (Hi, Número de capas (Nc y Ancho del depósito (Ad, en la morfología y el incremento de la resistencia al desgaste abrasivo de capas depositadas sobre acero 1020 utilizando el electrodo de fundición blanca al cromo UTP Ledurit – 61. Empleando la microscopia óptica se identificaron y cuantificaron las fases presentes, analizando su efecto en el desgaste. Siendo determinante la influencia de la inclinación de las dendritas y su posición con respecto a 90° en el incremento de la resistencia al desgaste abrasivo. Se caracterizaron los posibles mecanismos de daño superficial provocado por desgaste abrasivo empleando la microscopia electrónica de barrido. Se propusieron modelos lineales para correlacionar la influencia de la cantidad, tamaño, dispersión de los carburos y el ángulo de inclinación de las dendritas, en el incremento de la resistencia al desgaste.The influence of different parameters in layer morphology and abrasion resistance of Fe-Cr-C electrodes UTP Ledurit – 61 on steel 1020 was studied. Introduced Energy (Hi, Number of Layers (Nc, and Deposit Width (Ad were the main parameters considered. The metallographic identification and quantification of metal phases and the determination of their effect in abrasion resistance were made with optical microscopy. The abrasive wear test characterized by scanning electron microscopy, defines a possible mechanism of surface damage. It was found that the angle formed between a normal line to the surface and the dendrite inclination is directly related with the increment of wear resistance. Lineal models that correlate wear resistance with quantity, size, and carbide dispersion and dendrite angle inclination were also developed.

  6. CONSUMO DE NUTRIENTES, DIGESTIBILIDADE IN VIVO E IN VITRO DE DIETAS PARA CÃES CONTENDO POLPA DE CITRUS E FOLHA DE ALFAFA

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    Malafaia Maria Isabel Fonseca Rocha

    2002-01-01

    Full Text Available Determinaram-se os consumos de nutrientes e a digestibilidade aparente, in vivo e in vitro, em dez cadelas submetidas a uma dieta controle (R0 acrescida de 10 (R10 e 20% (R20 de uma mistura contendo polpa de citros (PC e folhas de feno de alfafa. A digestibilidade foi estimada pela coleta total de fezes e pelo uso das cinzas insolúveis em ácido. Quando expressos em % do peso vivo, os consumos de água, de matéria seca (MS, de matéria orgânica (MO e de proteína bruta (PB diminuiram à medida que os níveis de fibra aumentaram. Entretanto, a digestibilidade da MS, da PB, da fibra em detergente neutro (FDN e do extrato etéreo (EE aumentou com o acréscimo do consumo das fontes fibrosas. A digestibilidade estimada pelos dois métodos resultou em valores cuja diferença não ultrapassou 5 unidades. Houve diferenças nos valores de digestibilidade in vitro quanto à origem do inóculo fecal e os maiores valores foram para as amostras dos ingredientes fibrosos incubados com inóculo oriundo dos animais que estavam ingerindo as dietas contendo as fontes de fibra. A polpa de citros resultou na maior digestibilidade in vitro, enquanto que a ração controle, na menor.

  7. Avaliação de plantas transgênicas de Petunia x hybrida contendo o gene Psag12 - ipt cultivadas sob deficiência nutricional.

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    Francine Lorena Cuquel

    2001-05-01

    Full Text Available Deficiência nutricional em plantas pode causar clorose, necrose, desfolha, redução do crescimento e da produtividade e senescência prematura. Aplicações xógenas de citocinina podem aliviar tais sintomas. Este estudo foi efetuado para avaliar os efeitos da produção auto-regulada de citocinina na tolerância de plantas de petúnia (Petunia x hybrida à deficiência nutricional. Um gene quimérico contendo o promotor SAG12 unido ao gene ipt, o qual codifica a produção de isopentenyl transferase, uma enzima da rota metabólica da biossíntese de citocinina, foi introduzido em petúnia através de transformação mediada por Agrobacterium. Duas plantas contendo o gene ipt foram selecionadas e autopolinizadas para obtenção das linhas a serem submetidas à deficiência nutricional. Ambas as linhas PSAG12–ipt avaliadas foram mais tolerantes à deficiência nutricional que as plantas do tipo selvagem. Os resultados indicam que a produção endógena de citocinina pode aumentar a tolerância das plantas à deficiência nutricional.

  8. Desenvolvimento de formulações de biscoitos tipo cookie contendo café Development of cookie formulations containing coffee

    Directory of Open Access Journals (Sweden)

    Melissa de Abreu Andrade Rodrigues

    2007-03-01

    Full Text Available Este trabalho teve como objetivo desenvolver formulações de biscoitos tipo cookie contendo café. Desenvolveram-se três formulações com inserção de café como: bebida tipo expresso, café solúvel e café torrado e moído, utilizando como base uma formulação americana adaptada aos ingredientes brasileiros e à inserção de café. A composição centésimal média (base seca foi: 7% umidade, 70% carboidratos, 8% proteínas, 21% gorduras e 1% minerais, com valor calórico médio de 499 kcal.100 g -1. A composição centesimal e o valor calórico observados foram similares a valores reportados para biscoitos cookie comercialmente disponíveis. A forma de inserção de café afetou as características sensoriais dos produtos, avaliados por metodologia descritiva de perfil de sabor e de textura. A Formulação 1 (bebida tipo expresso apresentou valores inferiores para a intensidade dos atributos referentes à presença de rachaduras, fragmentação, presença de pontos escuros, aroma de café e queimado. A Formulação 2 (café solúvel apresentou notas superiores de intensidade dos atributos de cor marrom, brilho, sabor amargo e de queimado, sabor residual de açúcar mascavo e crocância da borda e inferiores para concavidade. A Formulação 3 (café torrado e moído apresentou valores superiores para a presença de pontos escuros. As três formulações apresentaram notas satisfatórias e equivalentes de aceitação por crianças.The aim of the present study is to develop cookie formulations containing coffee. Three formulations were developed, each with a distinct way of adding coffee: espresso beverage, instant coffee and roasted coffee powder. The average proximate composition (dry basis of the formulations was 7% moisture, 70% carbohydrates, 8% protein, 21% fat and 1% minerals, resulting in an average caloric value of 499 kcal per 100 g product. Both the proximate composition and average caloric value were similar to values reported

  9. Cascarilla de arroz: material alternativo y de bajo costo para el tratamiento de aguas contaminadas con cromo (vi

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    Doria Herrera Gloria María

    2011-11-01

    Full Text Available Este trabajo muestra la capacidad de la cascarilla de arroz para remover iones de Cr (VI en aguas simuladas de curtiembres a condiciones de laboratorio. La infl uencia de las variables pH, concentración inicial del metal, dosifi cación de adsorbente y tiempo de contacto sobre el proceso de adsorción fue determinada. Se encontró remociones superiores al 94% a un valor de pH 1, dosifi cación de 3 g/L, concentración de 3 mg/L, velocidad de agitación de 127 rpm y a un tiempo de contacto de 720 min. Los resultados se evaluaron con un nivel de signifi cancia del 95% haciendo uso de la herramienta estadística ANOVA. La información referente al equilibrio del proceso fue ajustada a los modelos de Freundlich, Langmuir, Dubinin- Raduskevich y Thempkin, obteniendo buena correlación con la isoterma de Langmuir, con un valor de capacidad de adsorción de 1.25 mg/g a un pH 1. Para comprobar la ocurrencia de cambios estructurales sobre el material adsorbente se realizaron análisis a través de la técnica DRIFT (Espectroscopi a Infrarroja de Refl ectancia Difusa antes y después del proceso de remoción, así como un análisis bromatológico para determinar alguna variación en su composición.

  10. Pigmentos lipossolúveis e hidrossolúveis em plantas de salvínia sob toxicidade por cromo Liposoluble and hydrosoluble pigments in salvinia under chromium toxicity

    Directory of Open Access Journals (Sweden)

    P.F. Pereira

    2012-12-01

    Full Text Available Devido à intensa utilização industrial, o cromo é considerado um importante poluente ambiental. O presente trabalho objetivou determinar os teores de pigmentos hidro e lipossolúveis em plantas de salvínia expostas a concentrações crescentes de Cr, visando estabelecer parâmetros bioquímicos para utilização dessa macrófita em programas de biomonitoramento e/ou fitorremediação da poluição causada por esse poluente metálico em ambientes aquáticos. As plantas foram submetidas a concentrações crescentes de Cr e avaliadas após quatro, seis e dez dias de tratamento. Os resultados dos ensaios permitiram concluir que plantas de salvínia sob condições de estresse por Cr apresentam reduções nas concentrações das clorofilas a, b e total e, em contraste, aumentos nas concentrações de antocianinas totais. Embora a concentração de carotenoides totais não tenha sido alterada em resposta ao Cr, as variações nas concentrações dos demais pigmentos lipossolúveis e dos pigmentos hidrossolúveis observadas nas folhas das plantas de salvínia podem ser utilizadas como parâmetros bioquímicos de biomonitoramento da poluição causada por esse elemento metálico em ambientes aquáticos.Due to widespread industrial use, chromium is considered a serious environmental pollutant. This study aimed to determine the content of hydrosoluble and liposoluble pigments in salvinia plants exposed to increasing concentrations of Cr, to establish biochemical parameters for the use of macrophyta in pollution bio-monitoring programs and/or phyto-remediation in aquatic environments by this pollutant metal. The plants were exposed to increasing concentrations of Cr and evaluated after four, six, and ten days of treatment. The test results showed that salvinia plants under stress conditions for Cr exhibit decreases in the concentrations of chlorophylls a, b, and total, and, in contrast, increases in anthocyanin concentrations. Although the

  11. Ion-ion collisions

    International Nuclear Information System (INIS)

    Salzborn, Erhard; Melchert, Frank

    2000-01-01

    Collisions between ions belong to the elementary processes occurring in all types of plasmas. In this article we give a short overview about collisions involving one-electron systems. For collisions involving multiply-charged ions we limit the discussion to one specific quasi-one-electron system. (author)

  12. Determinación del contenido de compuestos de cromo en el cemento portland por espectrofotometría de absorción atómica. Primera parte

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    Gaspar-Tebar, Demetrio

    1976-09-01

    Full Text Available Not availableEn el presente trabajo se da cuenta de un procedimiento para determinar el contenido de compuestos de cromo en el cemento portland por absorción atómica, bien por el método directo o por el de las adiciones patrones. La fusión se realiza con LiBO2 y la eliminación de interferencias por adición de La (III (1%. Para el desarrollo del trabajo ha sido necesario averiguar dicho contenido por espectrofotocolorimetría del complejo formado por reacción del cromo presente en los cementos, una vez pasado a Cr (VI, con la s-difenilcarbacida. Por otra parte se ha estudiado una variación del método propuesto sustituyendo la fusión alcalina con Na2 C03, o con la mezcla Na2CO3-K2CO3, por la fusión con LiBO2 que proporciona resultados menos dispersos y una desviación estándar estimada, una precisión y un coeficiente de variación menores. Si bien la sensibilidad del método colorimétrico es mayor que la del método propuesto de absorción atómica, éste último es más rápido, con una precisión del mismo orden y, además, permite analizar cuantitativamente los compuestos de cromo siguiendo la marcha que normalmente se utiliza para los demás constituyentes del cemento por absorción atómica. Se hace un estudio estadístico, calculando la desviación estándar estimada, la precisión y el coeficiente de variación de los resultados obtenidos en diversos cementos y clínkeres de cemento portland españoles.

  13. Efecto de la adición de un 10 % en volumen de cromo en el comportamiento a tracción de aleaciones pulvimetalúrgicas NiAlCr

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    García-Barriocanal, J.

    2005-08-01

    Full Text Available The mechanical properties of Ni3Al-Cr reinforced with 10% in volume fraction of chromium particles produced by powder metallurgy have been studied. For this purpose, milled powders with composition of Ni-20.9Al-8Cr-0.49B (% at. with and without the addition of 10% in volume fraction of chromium particles have been produced. Both alloys were consolidated by hot isostatic pressing (HIP. After HIP, heat treatment was applied to homogenize the microstructure. The chromium reinforcement has an important effect in the yield strength and ultimate strength increase. The reinforced alloy presents a yield strength of 1300 MPa at room temperature with respect to 800 MPa for the un-reinforced material. After heat treatment, the yield strength of both alloys does not change significantly. However, a decrease in ductility and ultimate tensile strength have been observed

    En este trabajo se estudia la influencia de la adición de un 10 % en volumen, de cromo en las propiedades mecánicas de aleaciones Ni3Al-Cr procesadas por vía pulvimetalúrgica. Para ello se prepararon dos aleaciones: la primera, se obtuvo por molienda de polvo de composición Ni-20,9Al-8Cr-0,49B (% at. y, a la segunda, se le añadió un 10 % en volumen de partículas de cromo, mediante un proceso de mezcla, previo al de molienda. Ambas, fueron consolidadas mediante compactación isostática en caliente (HIP y, por último, se les aplicaron tratamientos térmicos para homogeneizar la microestructura. Los resultados experimentales han mostrado que el refuerzo de cromo tiene como efecto un importante aumento del límite elástico y de la resistencia. Así, el material reforzado presenta un límite elástico cercano a 1.300 MPa, a temperatura ambiente, frente a los 800 MPa que presenta el material sin reforzar, a la misma temperatura. En relación con las propiedades mecánicas de los materiales tratados térmicamente, se observa que ambos experimentan un acusado

  14. Efeito de soluções fluoretadas contendo xilitol e sorbitol no número de estreptococos do grupo mutans na saliva de seres humanos

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    Gonçalves Nilza Cristina Lopes Afonso de Valor

    2001-01-01

    Full Text Available O objetivo do estudo foi avaliar o efeito de soluções de fluoreto de sódio a 0,05% contendo 2,5% ou 12,5% de xilitol no número de estreptococos do grupo mutans presentes na saliva. Participaram do estudo duplo cego, do tipo cruzado, 50 meninos entre 8 e 16 anos, distribuídos aleatoriamente em quatro grupos. Destes, 33 finalizaram o estudo. As soluções utilizadas foram: solução placebo; solução de fluoreto de sódio a 0,05%; solução de fluoreto de sódio a 0,05% + 2,5% xilitol + 2% sorbitol; solução de fluoreto de sódio a 0,05% + 12,5% xilitol + 2% sorbitol. Os indivíduos utilizaram 20 mL de uma das soluções, duas vezes ao dia. Cada solução foi utilizada por um período experimental de 28 dias. Os períodos experimentais foram intercalados por períodos de descanso de 10 dias. As soluções contendo xilitol a 2,5% e 12,5% não apresentaram diferença significativa (P = 0,32 em termos do logaritmo do número de estreptococos do grupo mutans. No entanto, a diferença foi significativa quando essas soluções foram comparadas às soluções de fluoreto de sódio e placebo (P < 0,001. Os resultados sugerem que a solução de fluoreto de sódio a 0,05% com adição de xilitol a 2,5% ou 12,5% reduziu significativamente o número de estreptococos do grupo mutans.

  15. Tempo de reepitelização corneana com a instilação de colírio contendo hialuronato de sódio e carboximetilcelulose

    Directory of Open Access Journals (Sweden)

    Luciane Bugman Moreira

    2013-10-01

    Full Text Available OBJETIVO: Avaliar o tempo de reepitelização corneana pós abrasão usando colírios comercialmente disponíveis, um contendo hialuronato de sódio a 0,4%, outro contendo carboximetilcelulose a 1%, e comparar com a reepitelização sem instilação de colírio. MÉTODOS: Foram utilizados 24 coelhos, nos quais foi feita a abrasão mecânica da córnea nos 8 mm centrais. Esses animais foram divididos em três grupos. O primeiro grupo recebeu um colírio disponível comercialmente contendo hialuronato de sódio 0,4%, o segundo recebeu um colírio contendo carboximetilcelulose 1% e o terceiro não recebeu nenhuma droga. A avaliação foi feita a cada 24 horas por meio da análise de fotografias digitais sob luz azul de cobalto e coramento das córneas com fluoresceína a 2%. O estudo das imagens foi feito pelo sistema de análise de imagens do Autocad 2009®. A análise dos dados foi feita comparando o tempo total de reepitelização da córnea e a cada 24 horas entre os três grupos. RESULTADOS: A velocidade de reepitelização do grupo que usou colírio contendo hialuronato de sódio foi em média 90 horas; o grupo que usou carboximetilcelulose apresentou média de 105 horas; e o grupo que não usou nenhum tipo de lubrificante apresentou média de 108 horas para total reepitelização. Houve uma melhor performance na reepitelização após 96 horas nas córneas dos coelhos que usaram os colírios lubrificantes, sendo essa diferença estatisticamente comprovada. CONCLUSÃO: O colírio contendo hialuronato de sódio 0,4% mostrou índice de eficácia maior que aquele contendo carboximetilcelulose 1%, e este maior eficácia que o controle. Os resultados encontrados neste estudo mostram que o uso de lubrificantes no processo de reepitelização são de extrema valia e devem ser usados de rotina na clínica oftalmológica.

  16. Ion implantation

    International Nuclear Information System (INIS)

    Dearnaley, Geoffrey

    1975-01-01

    First, ion implantation in semiconductors is discussed: ion penetration, annealing of damage, gettering, ion implanted semiconductor devices, equipement requirements for ion implantation. The importance of channeling for ion implantation is studied. Then, some applications of ion implantation in metals are presented: study of the corrosion of metals and alloys; influence or ion implantation on the surface-friction and wear properties of metals; hyperfine interactions in implanted metals

  17. ADSORBENTES A BASE DE CASCARILLA DE ARROZ EN LA RETENCIÓN DE CROMO DE EFLUENTES DE LA INDUSTRIA DE CURTIEMBRES ADSORVENTES A BASE DE CASCA DE ARROZ NA RETENÇÃO DE CROMO DE EFLUENTES DA INDÚSTRIA DE CURTUMES RICE HUSK-BASED ADSORBENTS IN THE REMOVAL OF CHROMIUM FROM TANNING INDUSTRY EFLUENTS

    Directory of Open Access Journals (Sweden)

    YANSY MILENA RODRÍGUEZ

    2012-06-01

    Full Text Available Diferentes materiales adsorbentes fueron preparados a partir de la cascarilla de arroz (un residuo lignocelulósico agroindustrial, para la remoción de cromo presente en las aguas resultantes de la curtición, debido a su alta toxicidad para la salud humana y a nivel ambiental. La cascarilla de arroz se evaluó como ceniza y carbón activado con acido fosfórico e hidróxido de sodio como agentes activantes. La parte experimental consistió en la calcinación de la cascarilla de arroz, activación química, caracterización, pruebas de adsorción y absorción atómica; obteniendo mejores resultados el adsorbente activado con hidróxido de sodio. Para la activación de la cascarilla de arroz con NaOH se requirió una serie de experimentos para determinar las mejores condiciones de operación en el proceso de obtenci��n del carbón activado. Se obtuvo una mayor remoción en el carbón que se activo a una temperatura de 600°C, un tiempo de activación de 30 minutos y una concentración de la solución de 1% p/p; la remoción de cromo fue del 72,8% comparado con la cascarilla de arroz activada con H3PO4 que fue del 54,5% y la ceniza de cascarilla de arroz 49,2%.Diferentes materiais adsorventes fórum preparados a partir da casca de arroz, um resíduo lignocelulósico agroindustrial, para a remoção de cromo das águas resultantes da curtição, devido a sua alta toxicidade na saúde e ao nível ambiental. A casca de arroz, a qual se avalia como cinza e carvão ativado com acido fosfórico e hidróxido de sódio como agentes ativadores. A parte experimental consta de calcinação da casca de arroz, ativação química, caracterização, testes de adsorção e absorção atômica; obtendo os melhores resultados o adsorvente ativado com hidróxido de sódio. A ativação da casca de arroz com NaOH se precisaram uma série de experimentos para determinar as melhores condições de operação no processo de obtenção do carvão ativado. Obteve

  18. Efeitos da suplementação de cromo (Cr) sobre o dempenho produtivo, a população de protozoários e resposta imunitária em ovinos

    OpenAIRE

    Dallago, Bruno Stéfano Lima

    2008-01-01

    O presente trabalho foi desenvolvido com objetivo de determinar a influência da suplementação de cromo (Cr) dietético sobre o desempenho produtivo, população de protozoários ruminais e resposta imunitária em ovinos. O delineamento experimental foi inteiramente casualizado com quatro tratamentos e seis repetições. Para tanto foram utilizados 24 ovinos inteiros da raça Santa Inês com peso vivo médio inicial de 22,89 ± 2,23 kg e idade aproximada de três meses e 15 dias distribuídos em quatro tra...

  19. Acumulación de metales (cadmio, zinc, cobre, cromo, níquel y plomo) en especies del género Pelargonium, suministro desde el suelo, ubicación en la planta y toxicidad

    OpenAIRE

    Orroño, Daniela Inés

    2011-01-01

    La acción antrópica puede causar la contaminación de los suelos con metales. Para la remediación de pequeñas áreas contaminadas se sugirió el uso de plantas ornamentales. En esta tesis, inicialmente se estudió la capacidad de fitorremediación de tres especies del género Pelargonium en un suelo contaminado con cadmio, zinc, cobre, cromo, níquel y plomo, y se seleccionó la más tolerante (Pelargonium hortorum). Los objetivos fueron estudiar en qué fracciones químicas y físicas del suelo se ubica...

  20. Mejora de la tenacidad de un acero de ultraalto contenido en carbono nnediante unión por laminación con un acero al cromo y molibdeno

    Directory of Open Access Journals (Sweden)

    Pozuelo, M.

    2005-12-01

    Full Text Available Laminated composite materials containing five layers of ultrahigh carbon steel, 1.35%C, and five layers of a Cr-Mo steel were processed by roll bonding. The rolling procedure improves the bonding of layers and refines the microstructure, diminishing grain size and removing the pearlitic zones. Charpy impact tests were carried out to evaluate the impact properties. Toughness of the laminated composite was highly improved respect to the ultrahigh carbon steel. Moreover, it was double than that of the Cr-Mo steel in the arrester orientation. These results reveal the important role of the interfaces in the mechanical properties of the composite materials.

    Se procesaron mediante unión por laminación, dos materiales compuestos laminados de 10 capas: cinco capas de un acero de ultraalto contenido en carbono con 1,35 % C, alternadas con otras cinco de un acero al cromo y molibdeno. La laminación en caliente consolida la unión entre las capas y afina la microestructura, reduciendo el tamaño de grano y eliminando las zonas de perlita presentes inicialmente. Se realizaron ensayos de impacto Charpy para evaluar su resistencia al impacto. El material compuesto laminado mejoró sustancialmente la tenacidad del acero de ultraalto carbono, además de duplicar la resiliencia del acero al cromo y molibdeno en la orientación "en serie". Estos resultados ponen de manifiesto la importancia de las intercaras en las propiedades mecánicas de los materiales compuestos.

  1. Biossorção de níquel e cromo de um efluente de galvanoplastia utilizando alga marinha pré-tratada em coluna - DOI: 10.4025/actascitechnol.v31i2.864

    Directory of Open Access Journals (Sweden)

    Márcia Teresinha Veit

    2009-06-01

    Full Text Available Este trabalho teve por objetivo o estudo da biossorção dos íons cromo e níquel presentes no efluente do processo de uma indústria de galvanoplastia, utilizando como biossorvente a biomassa de alga marinha pré-tratada Sargassum filipendula. As condições de operação da coluna foram: massa de biossorvente de 8 g, pH do efluente de alimentação 3,85, temperatura de 30ºC, vazão de 6 mL min.-1 e concentrações iniciais de alimentação (cromo+níquel de 7,12 e 3,66 meq L-1. Foi empregado um modelo matemático para representar a dinâmica da biossorção em coluna de leito fixo. O modelo da isoterma multicomponente de Langmuir (qm= 2,78 meq g-1, bCr = 0,85 L meq-1, bNi = 0,08 L meq-1 foi utilizado para representar os dados de equilíbrio da coluna e para simular a dinâmica de biossorção dos íons. Os resultados da simulação demonstraram que o modelo matemático empregado foi capaz de descrever satisfatoriamente a complexa dinâmica de biossorção dos íons presentes no efluente.

  2. Avaliação da estabilidade e atividade antioxidante de uma emulsão base não-iônica contendo resveratrol

    Directory of Open Access Journals (Sweden)

    Marcela Kist Lange

    2009-03-01

    Full Text Available Vários são os fatores que podem ocasionar a instabilidade de uma emulsão, destacando-se a oxidação, reação prevenida pelo emprego de antioxidantes. O butil-hidróxi-tolueno (BHT tem sido um dos antioxidantes sintéticos mais utilizados em formulações cosméticas, porém, a busca da indústria farmacêutica e cosmética pelo emprego de produtos de origem natural tem sido cada vez maior. Visto isso, o objetivo do presente trabalho foi a incorporação do resveratrol, um composto fenólico encontrado principalmente em uvas bem como em vinhos tintos, em uma emulsão base não-iônica para avaliação do perfil de estabilidade e atividade antioxidante em comparação a uma emulsão base não-iônica contendo o BHT. O perfil de estabilidade foi analisado pela observação das características organolépticas, determinação do pH e espalhabilidade, e atividade antioxidante através do teste com o radical livre 2,2-difenil-1-picrilhidrazila (DPPH. Em relação à estabilidade, a altas temperaturas, a emulsão contendo BHT mostrou-se superior à emulsão contendo resveratrol. Pela análise da atividade antioxidante, o resveratrol tanto na sua forma de extrato seco, como quando incorporado na emulsão, demonstrou significativa superioridade em relação ao BHT, podendo ser sua utilização uma alternativa viável em preparações cosméticas, devido ao seu grande potencial antioxidante.There are several factors that can lead to the instability of an emulsion, highlighting the oxidation, a reaction prevented by the use of antioxidants. The butylated hydroxytoluene (BHT has been one of the most used synthetic antioxidants in cosmetic formulations; however, pharmaceutical and cosmetic industries have shown considerable interest regarding the search for the use of natural products. Based on this, the objective of this work was the incorporation of resveratrol, a natural phenolic compound found mainly in grapes as well as in red wines, into a non

  3. Concentração plasmática de cortisol, uréia, cálcio e fósforo em vacas de corte mantidas a pasto suplementadas com levedura de cromo durante a estação de monta Cortisol, urea, calcium and phosphorus plasma concentration in grazing beef cows supplemented with high chromium yeast during breeding season

    Directory of Open Access Journals (Sweden)

    Eduardo Fabian Aragón Vásquez

    2003-08-01

    Full Text Available Foi pesquisada a influência da suplementação com cromo (Cr sobre a concentração plasmática de cortisol, uréia, cálcio e fósforo em vacas zebu mantidas a pasto e numa situação de estresse calórico durante a estação de monta. Foram utilizadas trinta vacas primíparas com peso entre 380 e 385kg. Os animais foram divididos em grupos de 15 vacas, formando o tratamento suplementado com Cr e o tratamento não suplementado (controle. As vacas pastorearam em piquetes formados por Brachiaria brizanta cv. Marandu. A fonte de Cr foi levedura enriquecida (1g Cr kg-1 de produto comercial e foi adicionado à mistura mineral aportando 0,017% de Cr. Amostras de sangue foram tomadas em três períodos através de venipunção jugular e coletadas em tubos contendo heparina. As amostras de plasma foram analisadas para fósforo, cálcio, uréia e cortisol. Os dados foram analisados como um desenho de blocos ao acaso. O consumo médio diário de mistura mineral foi de 72,92g no grupo suplementado com Cr (12,40mg Cr/cabeça/dia e 77,84g no grupo controle (0,78mg Cr/cabeça/dia. A concentração plasmática de cortisol, no grupo suplementado com Cr, foi menor que no tratamento controle (2,11mg dl-1 vs. 3,29mg dl-1. As concentrações plasmáticas de fósforo (6,36mg dl-1 vs 3,56mg dl-1 e de cálcio (12,87mg dl-1 vs 9,02mg dl-1 foram maiores no grupo suplementado com Cr durante o primeiro período, mas não existiram diferenças no segundo e terceiro períodos de colheita. Os níveis plasmáticos de uréia (17,13mg dl-1 vs. 17,70mg dl-1 não foram diferentes entre os grupos experimentais.The influence of supplemental chromium (Cr on plasma cortisol, urea, calcium and phosphorus concentration were investigated in grazing cattle in caloric stress situation during the breeding season. Thirty primiparous zebu cows with 380 to 385kg of body weight were assigned to the following treatments: 15 cows fed supplemental Cr and 15 cows without supplemental Cr (Control

  4. Influence of a cobalt-chromium metal framework on surface roughness and Knoop hardness of visible light-polymerized acrylic resins Influência de estrutura metálica de cobalto-cromo na rugosidade e dureza Knoop superficiais de resinas acrílicas polimerizadas por luz visível

    Directory of Open Access Journals (Sweden)

    Joane Augusto de Souza Júnior

    2006-06-01

    bacteriano. O objetivo deste trabalho foi comparar os valores de rugosidade e dureza Knoop de uma resina polimerizada por luz visível com resinas acrílicas polimerizadas por microondas ou banho de água, na presença de estrutura metálica. Para tanto, trinta e seis espécimes nas dimensões de 30,0 x 4,0 ± 0,05 mm de resina acrílica polimerizada por microondas (Onda Cryl, luz visível (Triad e banho de água (Clássico (controle, contendo barra metálica de cobalto cromo foram preparadas. Após a polimerização, os espécimes foram acabados e polidos com lixas abrasivas de 360 a 1000 de granulação em politriz, seguidas de pasta de diamante e disco de feltro. A rugosidade foi avaliada em perfilômetro mecânico (Surfcorder SE 1700 e a dureza Knoop (Kg/mm² em microdurômetro (Shimadzu HMV 2000 a 50, 100, 200, 400 e 800 µm de distância da barra metálica. Os valores de rugosidade e dureza Knoop foram submetidos a ANOVA a dois critérios e comparadas com os testes Tukey e Kruskal Wallis ao nível de significância de 5%. Diferenças estatisticamente significantes foram encontradas (p0.05. Dentro das limitações deste estudo in vitro, concluiu-se que a presença de metal não influenciou nos valores de rugosidade e dureza das resinas.

  5. Equivalência farmacêutica e estudo comparativo dos perfis de dissolução de medicamentos genéricos contendo paracetamol

    Directory of Open Access Journals (Sweden)

    Thiele Faccim de Brum

    2012-08-01

    Full Text Available Este trabalho teve como objetivo principal comparar, através do estudo de equivalência farmacêutica e do perfil de dissolução in vitro, oito medicamentos genéricos contendo paracetamol 750 mg, comercializados na região central do Rio Grande do Sul. As análises foram realizadas em conformidade com a monografia do paracetamol comprimidos, descrita na Farmacopeia Brasileira (2010. Os genéricos A, B, D, E, F, G e H são equivalentes farmacêuticos do medicamento referência, pois foram aprovados em todos os testes a que foram submetidos. O Genérico C, no entanto, foi reprovado no doseamento. Quando avaliados em relação ao perfil de dissolução, pelos critérios descritos na RDC 31/2010, somente o genérico E não possui o mesmo perfil de dissolução que o medicamento referência, porém quando comparados pela eficiência de dissolução (ED podemos verificar que somente os Genéricos G, H, F e A possuem a mesma ED que o medicamento referência.

  6. Dermatite de contato por metais: prevalência de sensibilização ao níquel, cobalto e cromo Metal contact dermatitis: prevalence of sensitization to nickel, cobalt and chromium

    Directory of Open Access Journals (Sweden)

    Ida Duarte

    2005-04-01

    Full Text Available FUNDAMENTOS: Dermatite de contato (DC por metais é dermatose comum em diversos grupos populacionais. OBJETIVOS: Caracterizar o grupo com DC ao níquel, cromo e cobalto na população estudada, determinar a prevalência da sensibilização aos mesmos, verificar as combinações de testes positivos e comparar com a literatura. CASUÍSTICAS E MÉTODOS: Foram realizados testes epicutâneos em 1.208 pacientes com hipótese diagnóstica de DC. Selecionaram-se aqueles com testes positivos aos metais. RESULTADOS: Obtiveram-se 404 pacientes (33,5% da amostra com pelo menos um teste positivo ao níquel e/ou cobalto e/ou cromo. Foram 487 testes positivos a metais, correspondendo a 48% de todos os testes positivos. A maioria dos pacientes era do sexo feminino (72%, de cor branca (54%, com idade entre 40 e 49 anos (25% empregada na área de limpeza (59%. Dos 404, 329 (81,5% foram positivos a apenas um tipo de metal, sendo 60% com teste positivo ao níquel, 13% ao cromo e 8,5% ao cobalto. Cerca de 18,5% apresentaram testes positivos a dois ou três metais, sendo a associação níquel/cobalto a mais comum. CONCLUSÕES: A sensibilização aos metais foi de 48%, entre os testes positivos e ocorreu principalmente em mulheres da cor branca, na faixa etária de 40 a 49 anos e sem correlação ocupacional. A maioria apresentou sensibilização a apenas um metal. Esses dados são semelhantes aos de outros trabalhos já publicados.BACKGROUND: Metal contact dermatitis (nickel, cobalt and chromium is a common dermatosis among several population groups. OBJECTIVE: To describe the individuals with metal contact dermatitis in the group studied, to determine the prevalence of skin sensitization by nickel, cobalt and chromium, to verify the positive test combinations among these three substances and to compare our results with the literature. PATIENTS AND METHODS: Patch test was performed in 1208 patients with a presumptive diagnosis of contact dermatitis. Those with

  7. Avaliação das técnicas de precipitação química e encapsulamento no tratamento e destinação conjunta de resíduos líquidos contendo cromo e vidrarias de laboratório Evaluation of chemical precipitation and encapsulation techniques in the treatment and joint disposal of liquid wastes containing chromium and laboratory glassware

    Directory of Open Access Journals (Sweden)

    Juliana Graciela Giovannini

    2008-01-01

    Full Text Available In this paper, we present procedures for the treatment and final disposal of residual solutions containing chromium, in order to evaluate the effectiveness of chemical precipitation of the metal and the potential of the glass encapsulation technique, using broken laboratory glassware. The results demonstrated that pH-values convenient for chemical precipitation are between 10 - 11. With regard to Cr(OH3 encapsulation, the leaching and solubilization tests allowed to classify the waste as non-dangerous and non-inert. Finally, it is pointed out that the adoption of waste management practices in universities should be encouraged, helping to train professionals skilled in good laboratory practices.

  8. Cinética da degradação ruminal de dietas contendo farelo de casca de pequi Ruminal degradation kinetics of diets with pequi hulls bran

    Directory of Open Access Journals (Sweden)

    Luciana Castro Geraseev

    2011-09-01

    Full Text Available A casca de pequi é um resíduo do processamento do fruto, encontrado em grande volume nas regiões do cerrado brasileiro, que pode constituir uma alternativa para a alimentação de ruminantes. Avaliou-se a cinética da degradação ruminal da matéria seca (MS, proteína bruta (PB e fibra em detergente neutro (FDN do farelo da casca de pequi (FCP e de dietas contendo diferentes níveis do resíduo em substituição ao capim-elefante (CE. Foram utilizados quatro caprinos, machos, portando cânulas ruminais, dispostos em um delineamento experimental de blocos ao acaso com parcela subdividida. Avaliaram-se os parâmetros de degradabilidade do FCP, capim-elefante e de dietas contendo 0, 10, 20 e 30% de FCP em substituição ao CE. Os alimentos foram incubados no rúmen nos tempos de 4, 8, 12, 24, 48, 72 e 96 horas. Os resultados indicaram degradação potencial da MS, PB e FDN do resíduo superiores a 90, 80 e 80%, respectivamente. A adição do FCP em substituição ao CE resultou em maior degradabilidade da matéria seca e fibra em detergente neutro, reflexo da maior fração solúvel e potencialmente degradável da MS do FCP. Para a fração protéica, a adição de FCP correlacionou-se negativamente com a fração solúvel, degradação potencial e efetiva, e positivamente com a fração insolúvel potencialmente degradável. A substituição do capim-elefante por FCP permite melhor aproveitamento da dieta, elevando o aporte de nutrientes ao animal.The pequi hulls is a waste of pequi processing, found in large volume in the Brazilian Cerrado, which may provide an alternative to ruminants' diet. This experiment was developed to evaluate the ruminal degradation kinects of dry matter (DM, crude protein (CP and neutral detergent fiber (NDF of pequi hulls bran (PHB and experimental diets, with different substitution levels of elephant grass (EG by pequi hulls bran. Four goats castrated with ruminal cannulas were used in a randomized complete block

  9. Estruturação de cristais de gelo em soluções aquosas contendo solutos diversos Ice crystals structuring in water solutions containing different solutes

    Directory of Open Access Journals (Sweden)

    CLÉCIA SILVA CARNEIRO

    2000-02-01

    Full Text Available Existe uma grande demanda de conhecimentos na área de criopreservação de frutos tropicais com vistas a reduzir os danos celulares provocados por cristais de gelo durante o congelamento. O objetivo deste trabalho foi estudar a capacidade de estruturação de cristais de gelo. Soluções aquosas contendo arabinose, glicose, piridoxina, creatina, metionina, lisina e arginina, foram submetidas a congelamento lento em ar estático e as amostras resultantes examinadas por microscopia ótica sob luz polarizada. Os açúcares arabinose e glicose provocaram nos cristais de gelo estruturações que variaram de uma configuração hexagonal a uma arbórea, dentre outras. Vitaminas hidrossolúveis e compostos hidrofílicos ou hidrofóbicos favoreceram a formação de arranjamentos circulares filamentosos.There is a great demand for information about the cryopreservation of tropical fruits to reduce cell damage caused by ice crystals during freezing. The objective of this work was to study the structuring capacity of ice cristals. Water solutions having arabinose, glucose, pyridoxine, creatine, methionine, lysine and arginine were submitted to a slow freezing process and the resulting samples were examined under an optical microscope under polarized light. Sugars (arabinose and glucose caused a range of structures, from hexagonal to tree-like configurations, among others. Water soluble vitamins and hydrophilic or hydrophobic compounds favored the formation of needles arranged in a circular-type manner.

  10. Valor nutritivo de dietas contendo torta de mamona submetida a métodos alternativos de destoxificação para ovinos

    Directory of Open Access Journals (Sweden)

    R.N. Furtado

    2012-02-01

    Full Text Available Avaliaram-se o consumo e a digestibilidade de nutrientes por ovinos alimentados com rações contendo torta de mamona sem tratamento (NT, tratadas com calcário calcítico (CC, ureia (UR, fosfato monobicálcico (FOS e por autoclave (ACL. Foram utilizados 20 ovinos em delineamento em blocos ao acaso, sendo 10 machos inteiros e 10 fêmeas, mestiços de raça Morada Nova. As dietas foram isoproteicas e isoenergéticas. A ricina foi parcialmente desnaturada pelos tratamentos de destoxificação da torta de mamona. Não houve efeito dos tratamentos de destoxificação da torta de mamona sobre o consumo de nutrientes. A digestibilidade da fibra em detergente neutro no tratamento NT foi de 57,5%, maior que no tratamento CC, de 52,4%. A digestibilidade do extrato etéreo foi mais alta no tratamento CC, média de 71,3%, em relação ao tratamento FOS, de 68,2%. Houve maior consumo de fibra em detergente neutro e fibra em detergente ácido dos machos em relação às fêmeas quando o consumo foi expresso em g/dia. A torta de mamona NT pode ser utilizada em dietas de ovinos como alimento proteico alternativo, participando em até 8% da dieta total, sem ocasionar redução expressiva no consumo e na digestibilidade.

  11. Ion Colliders

    CERN Document Server

    Fischer, W

    2014-01-01

    High-energy ion colliders are large research tools in nuclear physics to study the Quark-Gluon-Plasma (QGP). The range of collision energy and high luminosity are important design and operational considerations. The experiments also expect flexibility with frequent changes in the collision energy, detector fields, and ion species. Ion species range from protons, including polarized protons in RHIC, to heavy nuclei like gold, lead and uranium. Asymmetric collision combinations (e.g. protons against heavy ions) are also essential. For the creation, acceleration, and storage of bright intense ion beams, limits are set by space charge, charge change, and intrabeam scattering effects, as well as beam losses due to a variety of other phenomena. Currently, there are two operating ion colliders, the Relativistic Heavy Ion Collider (RHIC) at BNL, and the Large Hadron Collider (LHC) at CERN.

  12. Recoil ions

    International Nuclear Information System (INIS)

    Cocke, C.L.; Olson, R.E.

    1991-01-01

    The collision of a fast moving heavy ion with a neutral atomic target can produce very highly charged but slowly moving target ions. This article reviews experimental and theoretical work on the production and use of recoil ions beyond the second ionization state by beams with specific energies above 0.5 MeV/amu. A brief historical survey is followed by a discussion of theoretical approaches to the problem of the removal of many electrons from a neutral target by a rapid, multiply charged projectile. A discussion of experimental techniques and results for total and differential cross sections for multiple ionization of atomic and molecular targets is given. Measurements of recoil energy are discussed. The uses of recoil ions for in situ spectroscopy of multiply charged ions, for external beams of slow, highly charged ions and in ion traps are reviewed. Some possible future opportunities are discussed. (orig.)

  13. Ion colliders

    International Nuclear Information System (INIS)

    Fischer, W.

    2010-01-01

    Ion colliders are research tools for high-energy nuclear physics, and are used to test the theory of Quantum Chromo Dynamics (QCD). The collisions of fully stripped high-energy ions create matter of a temperature and density that existed only microseconds after the Big Bang. Ion colliders can reach higher densities and temperatures than fixed target experiments although at a much lower luminosity. The first ion collider was the CERN Intersecting Storage Ring (ISR), which collided light ions (77Asb1, 81Bou1). The BNL Relativistic Heavy Ion Collider (RHIC) is in operation since 2000 and has collided a number of species at numerous energies. The CERN Large Hadron Collider (LHC) started the heavy ion program in 2010. Table 1 shows all previous and the currently planned running modes for ISR, RHIC, and LHC. All three machines also collide protons, which are spin-polarized in RHIC. Ion colliders differ from proton or antiproton colliders in a number of ways: the preparation of the ions in the source and the pre-injector chain is limited by other effects than for protons; frequent changes in the collision energy and particle species, including asymmetric species, are typical; and the interaction of ions with each other and accelerator components is different from protons, which has implications for collision products, collimation, the beam dump, and intercepting instrumentation devices such a profile monitors. In the preparation for the collider use the charge state Z of the ions is successively increased to minimize the effects of space charge, intrabeam scattering (IBS), charge change effects (electron capture and stripping), and ion-impact desorption after beam loss. Low charge states reduce space charge, intrabeam scattering, and electron capture effects. High charge states reduce electron stripping, and make bending and acceleration more effective. Electron stripping at higher energies is generally more efficient. Table 2 shows the charge states and energies in the

  14. Ion colliders

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, W.

    2011-12-01

    Ion colliders are research tools for high-energy nuclear physics, and are used to test the theory of Quantum Chromo Dynamics (QCD). The collisions of fully stripped high-energy ions create matter of a temperature and density that existed only microseconds after the Big Bang. Ion colliders can reach higher densities and temperatures than fixed target experiments although at a much lower luminosity. The first ion collider was the CERN Intersecting Storage Ring (ISR), which collided light ions [77Asb1, 81Bou1]. The BNL Relativistic Heavy Ion Collider (RHIC) is in operation since 2000 and has collided a number of species at numerous energies. The CERN Large Hadron Collider (LHC) started the heavy ion program in 2010. Table 1 shows all previous and the currently planned running modes for ISR, RHIC, and LHC. All three machines also collide protons, which are spin-polarized in RHIC. Ion colliders differ from proton or antiproton colliders in a number of ways: the preparation of the ions in the source and the pre-injector chain is limited by other effects than for protons; frequent changes in the collision energy and particle species, including asymmetric species, are typical; and the interaction of ions with each other and accelerator components is different from protons, which has implications for collision products, collimation, the beam dump, and intercepting instrumentation devices such a profile monitors. In the preparation for the collider use the charge state Z of the ions is successively increased to minimize the effects of space charge, intrabeam scattering (IBS), charge change effects (electron capture and stripping), and ion-impact desorption after beam loss. Low charge states reduce space charge, intrabeam scattering, and electron capture effects. High charge states reduce electron stripping, and make bending and acceleration more effective. Electron stripping at higher energies is generally more efficient. Table 2 shows the charge states and energies in the

  15. Metodologias para determinação da digestibilidade de dietas contendo fontes proteicas vegetal ou animal em cães Methodology for determination of digestibility of diets containing vegetable or animal protein sources in dogs

    Directory of Open Access Journals (Sweden)

    Carolina Pedro Zanatta

    2013-04-01

    Full Text Available Objetivou-se avaliar diferentes metodologias de determinação da digestibilidade em cães, alimentados com duas dietas contendo fontes proteicas animal (farinha de vísceras de aves - FVA e vegetal (farelo de soja - FS. As metodologias avaliadas foram: colheita total de fezes (CTF e os indicadores cinza insolúvel em ácido (CIA, fibra em detergente ácido (FDA e fibra bruta (FB. Foram utilizados 8 cães adultos, em delineamento Cross over, em parcela subdividida no tempo (parcela: fontes proteicas; e subparcela: metodologias de digestibilidade. O período experimental foi constituído por cinco dias de adaptação, com cinco dias de colheita total de fezes. A dieta contendo FS apresentou maior CDA da PB, enquanto a dieta contendo FVA apresentou maior CDA dos demais nutrientes e energia metabolizável (EM. Os CDA e EM determinados pela CTF e pelos indicadores não diferiram entre si, podendo ser determinados pelos indicadores FB, FDA e CIA, independentemente da fonte proteica da dieta.The objective was to evaluate different methods of measuring digestibility in dogs fed two diets containing animal (poultry by products - PBP and vegetable (soybean meal - SBM protein sources. The methods evaluated were: total fecal collection (TFC and indicators: acid insoluble ash (AIA, acid detergent fiber (ADF and crude fiber (CF. Eight dogs were distributed in Cross Over in split plots (plot: sources of protein; subplot: methods for digestibility, fed by five days of adaptation and five days of total fecal collection. The diet containing SBM had a higher ADC of CP, while the diet containing POM showed higher ADC of all nutrients and metabolizable energy (ME. The ADC and ME determined by the TFC and the indicators did not differ. Thus, the ADC of diets in dogs can be determined by TFC and CF, ADF and AIA indicators, regardless of source of dietary protein.

  16. Microestrutura, fases cristalinas e propriedades elétricas de porcelanas aluminosas contendo diferentes concentrações de Fe2O3sinterizadas em atmosfera redutora e oxidante

    Directory of Open Access Journals (Sweden)

    D. H. Piva

    2015-09-01

    Full Text Available ResumoPorcelanas aluminosas contendo diferentes concentrações de Fe2O3 foram sinterizadas em atmosfera oxidante e redutora. A microestrutura e fases formadas foram investigadas com o auxílio de difração de raios X e microscopia eletrônica de varredura. Espectroscopia de impedância foi utilizada para estudar as propriedades elétricas. Os resultados indicaram que todas as amostras apresentaram mulita e coríndon como fases majoritárias e pequenas frações de quartzo. A adição de Fe2O3 provocou o surgimento de hematita nas amostras sinterizadas em atmosfera oxidante e, ferro metálico nas amostras contendo > 3%p sinterizadas em atmosfera redutora. Os espectros de impedância indicam que as características da fase vítrea e interface entre fase vítrea /fases cristalinas regem o comportamento elétrico global das amostras. Não obstante, diferentes atmosferas de queima provocam efeitos opostos na resistividade elétrica das porcelanas contendo Fe2O3. A presença de hematita foi considerada a responsável pela diminuição da resistividade elétrica nas amostras sinterizadas em atmosfera oxidante, enquanto que o aumento na resistividade elétrica das amostras sinterizadas em atmosfera redutora foi atribuído à elevada quantidade de fase vítrea e porosidade. Estes resultados indicam que atmosfera redutora durante a queima pode favorecer o uso de matérias-primas com maiores concentrações de Fe2O3, desde que todo óxido de ferro tenha se dissolvido na fase liquida durante a queima.

  17. Artigo revisão: estabilização de suspensões aquosas contendo grafite Review article: stabilization of graphite-containing aqueous suspensions

    Directory of Open Access Journals (Sweden)

    I. R. de Oliveira

    2000-12-01

    Full Text Available A aplicação de materiais refratários contendo grafite tem aumentado muito nos últimos 10 anos, especialmente no caso de concretos refratários. Tais refratários são considerados compósitos singulares em que o grafite contribui para a redução da expansão térmica, aumento da resistência ao choque térmico, da energia de fratura e da resistência ao ataque por escória. Entretanto, sua baixa molhabilidade por água e líquidos orgânicos dificulta o seu processamento por meio de suspensões. Em virtude disso, um tratamento da superfície das partículas de grafite deve ser realizado visando melhorar sua molhabilidade e dispersão em suspensão aquosa. As principais características estruturais e superficiais responsáveis pela sua baixa molhabilidade e os métodos de tratamento superficial mais utilizados são abordados nesta revisão. Tais métodos de tratamento superficial envolvem, principalmente, a adsorção de agentes ativos na superfície, como é o caso dos surfactantes e polieletrólitos, e a cobertura da superfície por uma espécie hidrofílica.The application of graphite-containing refractories has increased enormously over the latest ten years, especially in the case of refractory castables. Graphite in such refractories contributes to the reduction of the material thermal expansion and improvement on its thermal shock resistance, fracture energy and slag resistance. However, the low wettability of graphite in water and organic liquids represents a barrier to its processing. Therefore, a surface treatment of graphite particles is required to improve its wettability and enable its dispersion in aqueous suspensions. The main structural and surface characteristics responsible for the low wettability of graphite, as well as the most common surface treatment methods applied are discussed in the present review article. Such surface treatment methods include the surface covering of graphite by hydrophilic species and the

  18. Consumo e digestibilidade aparente em bezerros da raça holandesa alimentados com dietas contendo diferentes níveis de volumoso

    Directory of Open Access Journals (Sweden)

    Ricardo Dias Signoretti

    1999-02-01

    Full Text Available O objetivo deste trabalho foi avaliar o efeito de diferentes níveis de volumoso nas dietas sobre os consumos e as digestibilidades aparentes de matéria seca (MS, matéria orgânica (MO, proteína bruta (PB, extrato etéreo (EE, fibra em detergente neutro (FDN, carboidratos totais (CHOT e energia bruta (EB e sobre os consumos de nutrientes digestíveis totais (NDT. Trinta e cinco bezerros da raça Holandesa puros por cruzamento, não-castrados, com idade média de 60 dias e peso vivo inicial de 78 kg, foram distribuídos em delineamento inteiramente casualizado, com nove repetições por dieta, exceto para a dieta com 10% de volumoso, com oito repetições. Os animais foram alimentados à vontade com dietas contendo níveis de 10, 25, 40 e 55% de volumoso, na base da MS, usando-se feno de capim coast-cross (Cynodon dactylon, fubá de milho e farelo de soja, os quais constituíram dietas com aproximadamente 16% de PB. O óxido crômico foi usado para obtenção das estimativas dos fluxos de MS fecal. Os carboidratos totais foram obtidos por 100 - (%PB + %EE + %Cinzas. O consumo de NDT foi obtido por (cPB - PBf + 2,25 (cEE - EEf + (cCHOT - CHOTf, em que c significa consumo e f, excreção fecal. Não houve efeito dos níveis de volumoso nas dietas sobre os consumos de MS e MO (kg/dia, % PV e g/kg0,75 e de PB e CHOT (kg/dia e % PV. O consumo de FDN (kg/dia, %PV e g/kg0,75 aumentou, enquanto o consumo de EE e NDT (em kg/dia e %PV reduziu linearmente em função dos níveis de volumoso na dieta. Houve efeito linear decrescente sobre as digestibilidades aparentes de MS, MO, PB, EE, CHOT e EB, em função do aumento dos níveis de volumoso nas dietas, enquanto a digestibilidade aparente da FDN não foi influenciada. Os consumos de EE, FDN e NDT e as digestibilidades aparentes de MS, MO, EE, PB, CHOT e EB foram influenciados pelos níveis de volumoso nas dietas.

  19. Qualidade de medicamentos fitoterápicos contendo extrato de Aesculus hippocastanum registrados no Brasil / Quality of phytotherapeutic drugs registered in Brazil containing Aesculus hippocastanum extract

    Directory of Open Access Journals (Sweden)

    Evelin Elfriede Balbino

    2014-08-01

    Full Text Available As sementes de Aesculus hippocastanum L. (Hippocastanaceae, conhecida como casta-nha-da-Índia, são utilizadas em várias partes do mundo no tratamento da insuficiência venosa crônica. O objetivo do presente estudo foi avaliar a qualidade de amostras co-merciais de medicamentos fitoterápicos contendo extrato de sementes de A. hippocas-tanum. O total de 16 amostras comercializadas no Brasil com registro válido em março de 2013 foram avaliadas quanto à correspondência com as especificações do dossiê de registro aprovado pela ANVISA. As amostras foram analisadas em Laboratório Oficial, quanto ao perfil cromatográfico, teor de escina, características macroscópicas e micros-cópicas e peso médio. A bula e a rotulagem foram avaliadas por especialista da ANVISA. Os resultados apontaram que 13 dos 16 medicamentos avaliados apresentavam ao me-nos uma não-conformidade. Portanto, é imprescindível a implementação de ações de vigilância sanitária efetivas, com foco no monitoramento e avaliação de medicamentos fitoterápicos ao longo de sua comercialização. ------------------------------------------------------------------- The seeds of Aesculus hippocastanum L. (Hippocastanaceae, known as horse-chestnut, have been used in several parts of the world to treat chronic venous insufficiency. The present study aimed to evaluate the quality of commercial samples of herbal medicines containing extract of A. hippocastanum seeds. In total, 16 commercial samples from Brazilian market with a valid registration in March 2013 were analyzed for the concor-dance with the specifications contained in each application file approved by ANVISA. The fingerprint, the content of aescin, the mean weight and macro and microscopic analysis of these medicines were carried out in an official laboratory. Furthermore, the evalua-tion of the package leaflet and the packaging was achieved by an ANVISA specialist. The results showed that 13 of the 16 commercial

  20. Parâmetros sangüíneos de pacu Piaractus mesopotamicus (Holmberg, 1887 alimentados com dietas suplementadas com cromo trivalente em duas densidades de estocagem = Hematological parameters of pacu Piaractus mesopotamicus (Holmberg, 1887 fed diets supplemented with trivalent chromium in two stocking densities

    Directory of Open Access Journals (Sweden)

    Rodrigo Yudi Fujimoto

    2007-10-01

    Full Text Available O objetivo deste trabalho foi avaliar os efeitos da suplementação com cromo trivalente (0, 6, 12 e 18 mg kg-1 de ração sobre as variáveis hematológicas de Piaractus mesopotamicus, mantidos em duas densidades de estocagem (4 e 20 kg m-3. Os mantidos na maior densidade e alimentados com dietas suplementadas com 0 e 6 mg de cromo kg-1apresentaram redução do número de linfócitos circulantes, sugerindo má adaptação a essa condição de alta densidade. Nas dietas suplementadas com 12 e 18 mg kg-1, tal efeito não foi observado, porém verificou-se aumento do número de trombócitos no tratamento com 12 mg de cromo kg-1. A inexistência de diferença significativa entre os tratamentos, aos 30 dias, sugere a adaptação dos peixes ao tipo de alimento e à situação de alta densidade. Portanto, nas condições deste ensaio, a suplementação com 12 e 18 mg de cromo kg-1 é interessante como estratégia alimentar durante 15 dias.This work evaluated the effects of chromium supplementation on thehematological parameters of Piaractus mesopotamicus Holmberg, 1887 maintained in two stocking densities. Fish were fed diets supplemented with 0, 6, 12 and 18 mg trivalent chromium kg-1 dry ration and maintained at 4 and 20 kg m-3. The fish under high stockingdensity and fed diets supplemented with 0 and 6 mg kg-1 showed reduction in the number lymphocytes, which suggests non-adaptation to this condition of high density. This was not observed in fish fed diets supplemented with 12 and 18 mg chromium kg-1, but an increasein the number of thrombocytes was evident. The lack of difference between treatments after 30 days may suggest a possible adaptation of fish to the situation. It can be added that supplementation with 12 and 18 mg chromium kg-1 is an interesting feeding strategy for aperiod of 15 days.

  1. ion irradiation

    Indian Academy of Sciences (India)

    Swift heavy ions interact predominantly through inelastic scattering while traversing any polymer medium and produce excited/ionized atoms. Here samples of the polycarbonate Makrofol of approximate thickness 20 m, spin coated on GaAs substrate were irradiated with 50 MeV Li ion (+3 charge state). Build-in ...

  2. Ion microprobes

    International Nuclear Information System (INIS)

    Coles, J.N.; Long, J.V.P.

    1977-01-01

    An ion microprobe is described that has an ion extraction arrangement comprising two separate paths for ions and electrons diverging from a common point. A cone shaped or pyramidal guard electrode surrounds each path the apex angles being equal and coinciding with the said point. The guard electrodes are positioned to lie tangentially to each other and to a planar surface including the said point. An aperture is provided for the two paths at the apexes of both guard electrodes, and electrical connections between the guard electrodes enable the same potential to be applied to both guard electrodes. Means are provided for generating oppositely polarised electric fields within the guard electrodes, together with means for causing a focused ion beam to strike the common point without suffering astigmatism. The means for causing a focused ion beam to strike the said point includes an ion gun for directing an ion beam along one of the paths and means to provide an axial accelerating field there along. Optical viewing means are also provided. Existing designs enable only ions or electrons, but not both, to be extracted at any one time. (U.K.)

  3. Sistemática, taxonomía y domesticación de alpacas y llamas: nueva evidencia cromosómica y molecular Systematics, taxonomy and domestication of alpaca and llama: new chromosomal and molecular evidence

    Directory of Open Access Journals (Sweden)

    JUAN C MARÍN

    2007-06-01

    Full Text Available Existen cuatro especies de camélidos sudamericanos, dos de ellos silvestres, guanaco (Lama guanicoe y vicuña (Vicugna vicugna, y dos formas domésticas, alpaca (Lama pacos y llama (Lama glama, cuyo origen ha sido objeto de debate. En el presente estudio la variación en el patrón de bandas G de los cromosomas de llamas y alpacas y la secuencia de dos genes mitocondriales han sido usados para estudiar el origen y la clasificación de llamas y alpacas. Patrones de bandas cromosómicas similares fueron observados en las cuatro especies de Lamini, incluso similares a los descritos para camello, Camelus bactrianus. Sin embargo, se encontraron finas y consistentes diferencias en los brazos cortos del cromosoma 1, permitiendo separar a camellos, guanacos y llamas, de las de vicuñas y alpacas. Este patrón fue consistente incluso en un híbrido guanaco x alpaca. Relaciones equivalentes fueron encontradas en las secuencias completas del gen para citocromo b, así como en el árbol de expansión mínima de las secuencias parciales de la región control, agrupando a guanacos con llamas y a vicuñas con alpacas. Los análisis filogenéticos mostraron a V. vicugna y a L. guanicoe como grupos recíprocamente monofHéticos. El análisis de las secuencias de ambos genes mostró dos ciados entre las vicuñas, concordantes con las subespecies reconocidas para esta especie, pero los resultados obtenidos para guanacos no reflejaron la existencia de las cuatro subespecies previamente propuestas. El análisis combinado de variaciones cromosómicas y moleculares demostraron una alta similitud genética entre alpacas y vicuñas, así como entre llamas y guanacos. Aunque se revela hibridización direccional, nuestros resultados apoyan fuertemente la hipótesis de que la llama se deriva de L. guanicoe, y la alpaca de V. vicugna, apoyando la reclasificación de la alpaca como V. pacosFour camelid species exist in South America: two wild, the guanaco (Lama guanicoe and

  4. EVALUACIÓN Y REGULACIÓN DE PARÁMETROS EN UN EQUIPO DISEÑADO PARA LA DISMINUCIÓN DE CROMO(VI, PROVENIENTES DE LA INDUSTRIA DE RECUBRIMIENTOS GALVÁNICOS

    Directory of Open Access Journals (Sweden)

    Gema Eunice Acosta Niño

    2013-01-01

    Full Text Available Con el fin de generar los medios necesarios para poder llevar a cabo las pruebas de remoción de cromo(VI en aguas residuales de la industria galvánica, se realizó la captura de datos a partir de prototipo de equipo inicial a escala de laboratorio para conseguir el objetivo principal, disminuir la cantidad de metales en aguas residuales contaminadas con diferentes metales. Es así que con los datos obtenidos en el presente estudio se plantearon algunas modificaciones necesarias para mejorar las condiciones y eficiencia del equipo y aumentar las posibilidades de uso mediante la determinación de los parámetros de trabajo usando la técnica de electrocoagulación. Los parámetros analizados fueron: voltaje, intensidad de corriente, conductividad, pH y temperatura durante una hora de funcionamiento del reactor. A lo largo del texto se pueden observar los cambios realizados sobre el prototipo inicial, cuyo concepto principal es el manejo de la electrocoagulación, para disminuir la cantidad de metales en aguas residuales. Un resultado final de interés a analizar entre otros, es el consumo de energía, pues basándose en este consumo se calculó el valor final del gasto energético versus el costo ambiental, lo que sin duda resulta ser un aporte importante para su uso en la remoción de metales pesados y abre la posibilidad de continuar con estudios posteriores de este tipo para la elaboración de nuevos reactores mucho más eficientes y útiles en la industria en general, y como respuesta, ayudará bastante en la disminución de la contaminación ambiental.

  5. Estudio del comportamiento de los recargues multicapas de depósitos soldados de fundición blanca al cromo // Study of the hard facing weld behavior in deposits of white chromium steels.

    Directory of Open Access Journals (Sweden)

    R. Collazo-Carceller

    2009-05-01

    Full Text Available Se determina la influencia de los parámetros Energía introducida (Hi, Número de capas (Nc yAncho del depósito (Ad, en la morfología y el incremento de la resistencia al desgaste abrasivo decapas depositadas sobre acero 1020 utilizando el electrodo de fundición blanca al cromo UTPLedurit – 61. Empleando la microscopia óptica se identificaron y cuantificaron las fases presentes,analizando su efecto en el desgaste. Siendo determinante la influencia de la inclinación de lasdendritas y su posición con respecto a 90° en el incremento de la resistencia al desgaste abrasivo.Se caracterizaron los posibles mecanismos de daño superficial provocado por desgaste abrasivoempleando la microscopia electrónica de barrido. Se propusieron modelos lineales paracorrelacionar la influencia de la cantidad, tamaño, dispersión de los carburos y el ángulo deinclinación de las dendritas, en el incremento de la resistencia al desgaste.Palabras claves: morfología, desgaste abrasivo, parámetros de soldadura, dendritas, modelos.__________________________________________________________________________AbstractThe influence of different parameters in layer morphology and abrasion resistance of Fe-Cr-Celectrodes UTP Ledurit – 61 on steel 1020 was studied. Introduced Energy (Hi, Number of Layers(Nc, and Deposit Width (Ad were the main parameters considered. The metallographicidentification and quantification of metal phases and the determination of their effect in abrasionresistance were made with optical microscopy. The abrasive wear test characterized by scanningelectron microscopy, defines a possible mechanism of surface damage. It was found that the angleformed between a normal line to the surface and the dendrite inclination is directly related withthe increment of wear resistance. Lineal models that correlate wear resistance with quantity, size,and carbide dispersion and dendrite angle inclination were also developed.Key words: morphology, abrasive

  6. Ion implantation

    International Nuclear Information System (INIS)

    Johnson, E.

    1986-01-01

    It is the purpose of the present paper to give a review of surface alloy processing by ion implantation. However, rather than covering this vast subject as a whole, the survey is confined to a presentation of the microstructures that can be found in metal surfaces after ion implantation. The presentation is limited to alloys processed by ion implantation proper, that is to processes in which the alloy compositions are altered significantly by direct injection of the implanted ions. The review is introduced by a presentation of the processes taking place during development of the fundamental event in ion implantation - the collision cascade, followed by a summary of the various microstructures which can be formed after ion implantation into metals. This is compared with the variability of microstructures that can be achieved by rapid solidification processing. The microstructures are subsequently discussed in the light of the processes which, as the implantations proceed, take place during and immediately after formation of the individual collision cascades. These collision cascades define the volumes inside which individual ions are slowed down in the implanted targets. They are not only centres for vigorous agitation but also the sources for formation of excess concentrations of point defects, which will influence development of particular microstructures. A final section presents a selection of specific structures which have been observed in different alloy systems. (orig./GSCH)

  7. Using microalgae scenedesmus obliquus in the removal of chromium present in plating wastewaters; Empleo de microalga scenedesmus obliquus en la eliminaciond e cromo presente en aguas residuales galvanicas

    Energy Technology Data Exchange (ETDEWEB)

    Pellon, A.; Benitez, F.; Frades, J.; Garcia, L.; Cerpa, A.; Alguacil, F. J.

    2003-07-01

    Dumping wastewaters from plating industry with a high content in chromium is a potential hazard for people and environment. It is known that some metals, including the heavy metals, at low concentrations participate in different metabolic routes, but at high concentration are toxic for many living organisms. Some microorganism taking the heavy metals from the environment are capable of concentrating and accumulating large quantities of them in different citiplasmatic structures with no-toxic effects. Microalgaehave affinity by the polyvalent metals making possible their use as depollutant agent in waters that contains dissolved metallic ions as alternative methods when others methods of recycle are unusable. In this report a chromium removal study from a plating wastewater, using scenedesmus obliquus culture was made. The removal efficiency of Cr (VI) was 12% and Cr (III) was 27% and for condition of algae's immobilization removal of Cr (III) was 95%. (Author) 19 refs.

  8. Nutritional evaluation of elephant-grass silages with byproduct of annato Avaliação nutricional de silagens de capim-elefante contendo subproduto do urucum

    Directory of Open Access Journals (Sweden)

    Margareth Maria Teles Rêgo

    2010-10-01

    Full Text Available The objective of the present study was to evaluate the nutritional value of elephant-grass silages containing annato byproduct. Twenty intact rams were distributed in a complete randomized block design with five diets (0; 4; 8; 12 and 16% annato byproduct in the silage and four replications and used to estimate the intake, apparent nutrient digestibility, content of total digestible nutrients and nitrogen balance. The addition of annato byproduct raised the intakes of dry matter (DM, organic matter (OM, crude protein (CP, neutral detergent fiber (NDF, acid detergent fiber (ADF, ether extract (EE, total carbohydrates (TC, non-fibrous carbohydrates (NFC and total digestible nutrients (TDN, in body weight (%BW and in metabolic weight (g kg-1BW0.75. The digestibilities of DM (55.95%, OM (58.19%, CP (45.34%, NDF (52.79%, ADF (45.79%, EE (34.96% and NFC (99.86% were not influenced by the addition of annato byproduct. The inclusion of annato byproduct in elephant-grass silage increased digestibility of total carbohydrates, the TDN content and the nitrogen balance. The aditions of annato byproduct at levels up to 16% of the elephant grass silage natural matter improves nutrient intake and nitrogen balance.Objetivou-se avaliar o valor nutritivo de silagens de capim-elefante contendo subproduto do processamento do urucum. Vinte ovinos machos, não-castrados, foram distribuídos em delineamento inteiramente casualizado com cinco dietas (0; 4; 8; 12 e 16% de subproduto de urucum na silagem e quatro repetições, e utilizados para estimar o consumo, a digestibilidade aparente de nutrientes, o teor de nutrientes digestíveis totais e o balanço de nitrogênio. A adição de subproduto de urucum elevou os consumos de matéria seca (MS, matéria orgânica (MO, proteína bruta (PB, fibra em detergente neutro (FDN, fibra em detergente ácido (FDA, extrato etéreo (EE, carboidratos não-fibrosos (CNF, carboidratos totais e nutrientes digestíveis totais (NDT

  9. ARGAMASSA CONTENDO AGREGADO MIÚDO RECICLADO DE RESÍDUO DE CONSTRUÇÃO E DEMOLIÇÃO

    Directory of Open Access Journals (Sweden)

    Juliana Oliveira Malta

    2013-11-01

    Full Text Available Normal 0 21 false false false PT-BR X-NONE X-NONE Os diferentes tratamentos dados aos agregados reciclados influenciam nas propriedades das argamassas nos estados fresco e endurecido. Como estes agregados também possuem características peculiares, tais como, elevada absorção, forma lamelar, textura áspera e menor massa específica, surge a necessidade de estudar as diferentes práticas empregadas na dosagem de misturas contendo resíduos. Este trabalho tem como objetivo avaliar a influência da incorporação de agregado miúdo reciclado em argamassas nos estados fresco e endurecido. Foram realizadas misturas de referência, e com teores de 25% e 50% de substituição de agregado miúdo natural por agregado miúdo reciclado. Para avaliar a influência da adição do resíduo nas argamassas no estado fresco utilizou-se o ensaio da mesa de consistência. Para avaliar essa influência no estado endurecido, foram realizados os ensaios de resistência à compressão axial nas idades de 3, 7 e 28 dias, além do ensaio de Absorção por imersão, na idade de 28 dias. Os resultados mostram que as misturas com agregado miúdo reciclado apresentaram-se menos resistentes e mais absorventes em relação às de referência. Este fato pode endossar a ideia de que a água de compensação utilizada para misturar as argamassas recicladas pode não permanecer no interior do agregado reciclado, migrando para a pasta, aumentando a relação a/c da mesma, tornando-a mais porosa e menos resistente. /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Tabela normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso

  10. Sistemas biodegradáveis contendo acetato de prednisolona para administração orbitária Biodegradable systems containing prednisolone acetate for orbital administration

    Directory of Open Access Journals (Sweden)

    Ricardo Martins Duarte Byrro

    2009-08-01

    Full Text Available OBJETIVO: O presente estudo objetivou o desenvolvimento e a avaliação de um sistema biodegradável de liberação de fármacos com característica de liberação prolongada, destinado à administração orbitária de acetato de prednisolona (AP. MÉTODOS: O sistema desenvolvido, na forma de microesferas (MEs de poli-e-caprolactona (PCL contendo o AP, foi obtido pelo método de evaporação de solvente. As MEs foram caracterizadas por microscopia eletrônica de varredura (MEV, calorimetria diferencial exploratória (DSC, avaliação do teor de encapsulação e pelo perfil de liberação in vitro. O perfil de liberação in vivo foi avaliado em coelhos após administração peribulbar de uma suspensão aquosa das MEs. A biocompatibilidade local do sistema foi verificada por meio de análise histopatológica da região de implantação. RESULTADOS: Após obtenção das MEs, a análise morfológica por MEV mostrou a viabilidade do método de obtenção do sistema. O teor de AP encapsulado foi de 43 ± 7% e pode ser considerado bastante satisfatório. A caracterização do sistema por DSC, além de confirmar a sua estabilidade, não indicou a existência de interação entre o fármaco e o polímero. O estudo de liberação in vitro indicou que o sistema apresenta perfil de liberação prolongada. O estudo in vivo confirmou o perfil de liberação prolongado do AP a partir das MEs, sugerindo, também, a viabilidade do sistema devido à ausência de toxicidade local. CONCLUSÃO: O conjunto dos resultados obtidos neste trabalho é relevante e credencia o sistema desenvolvido como uma possível alternativa ao tratamento de orbitopatias inflamatórias.PURPOSE: The present study aimed to evaluate an injectable extended-release formulation of prednisolone acetate (PA for orbital administration. METHODS: Microspheres (MEs of poly-e-caprolactone (PCL containing PA were developed by the method of solvent evaporation. The MEs obtained were characterized by

  11. Comportamento ingestivo de ovinos Santa Inês alimentados com dietas contendo farelo de cacau Ingestive behavior of Santa Inês sheep fed diets with cocoa meal

    Directory of Open Access Journals (Sweden)

    Gleidson Giordano Pinto de Carvalho

    2008-04-01

    Full Text Available O experimento foi conduzido para avaliar o comportamento ingestivo de ovinos alimentados com dietas contendo farelo de cacau. Foram utilizados 16 ovinos Santa Inês fêmeas, não-gestantes e não-lactantes, com peso corporal médio de 25 kg e aproximadamente 12 meses de idade, mantidos em baias individuais. O farelo de cacau foi fornecido no concentrado nos níveis de 0, 10, 20 e 30% e, como volumoso, utilizou-se feno de mandioca. As dietas foram fornecidas em mistura completa, na proporção 50:50 volumoso:concentrado. Os tempos de alimentação, ruminação e ócio obtidos em 24 horas de observação foram semelhantes. Contudo, os animais que consumiram dietas com maiores níveis de farelo de cacau, acima de 14,8% de substituição no concentrado, reduziram o número de bolos ruminados por dia, que foi compensado pelo aumento do tempo de mastigações por bolo. Os consumos de matéria seca (MS e fibra em detergente neutro (FDN e a eficiência de alimentação (g MS e FDN/hora não foram influenciados pelos níveis de farelo de cacau na dieta, entretanto, esse alimento provocou alterações na eficiência de ruminação (g MS e FDN/bolo. O número de mastigações merícicas por bolo ruminado aumentou linearmente, enquanto o número de mastigações por dia apresentou comportamento quadrático, com valor máximo de 42.818,4 mastigações diárias para o nível de 16,9% de farelo de cacau. Embora não se tenha verificado diferença nos consumos de MS e FDN (kg/dia, a inclusão de farelo de cacau em dietas para ovinos Santa Inês afetou alguns parâmetros do comportamento ingestivo.The experiment was carried out to evaluate the ingestive behavior of sheep fed diets containing cocoa meal. Sixteen Santa Inês female sheep, no-pregnant, no-lactating, averaging 25 kg of body weight and 12 months of age, maintained in individual barns were used. The cocoa meal was fed in the concentrate at the levels of 0, 10, 20 and 30%, and as forage was cassava

  12. Emprego do ultra-som modo B e com efeito Doppler, termômetro infravermelho e medidas antropométricas na avaliação de uma formulação cosmética anticelulítica contendo extrato hidroglicólico de Trichilia catigua e Ptychopetalum olacoides Bentham

    OpenAIRE

    Idalina Maria Nunes Salgado Reis dos Santos

    2005-01-01

    Hidrolipodistrofia ginóide (H.L.D.G.), a celulite, é comumente tratada com cosméticos contendo extratos vegetais. O estudo realizado foi: ultra-sonografia na avaliação da espessura da hipoderme e a microcirculação cutânea; uso de termômetro infravermelho na medida da temperatura e análise das medidas antropométricas da uma formulação cosmética anticelulítica contendo extrato hidroglicólico de Trichilia catigua e Ptychopetalum olacoides Bentham (catuaba e marapuama). Foram realizadas medidas i...

  13. Efecto de la asociación alga-bacteria Bostrychia calliptera (Rhodomelaceae en el porcentaje de remoción de cromo en laboratorio The effect of chromium removal by Algae-bacteria Bostrychia calliptera (Rhodomelaceae consortia under laboratory conditions

    Directory of Open Access Journals (Sweden)

    Ana Lucía Rengifo-Gallego

    2012-09-01

    Full Text Available Para determinar el porcentaje de remoción de cromo en la asociación alga-bacteria, se tomaron ejemplares del alga Bostrychia calliptera de pneumatóforos de Avicennia germinans y Rizophora mangle, en la desembocadura del Río Dagua, Pacífico colombiano. El ensayo se realizó in vitro en agua marina sintética a dos concentraciones de cromo 5 y 10mg/L, empleando biorreactores con cuatro tratamientos; i material Alga-Bacteria (AB, ii material algal con antibiótico Alga-antibiótico (AA, iii consorcio bacteriano natural (CBN y iv control sin presencia de B. calliptera ni bacteria. Se monitoreó el comportamiento de poblaciones bacterianas y el porcentaje de disminución de cromo mediante AAS (Espectroscopía de absorción atómica. Se obtuvo diferencias significativas entre los tratamientos Alga-bacteria (AB y el consorcio bacteriano natural (CBN, siendo Alga-bacteria más eficiente a 10mg/L (87%. El consorcio bacteriano natural CBN obtuvo mayor porcentaje de remoción a bajas concentraciones de cromo a 5ppm (62.85%. Los resultados mostraron una interacción positiva entre las bacterias asociadas (CBN a la superficie del alga roja B. calliptera en su proceso acumulativo de cromo.Water pollution is one of the most important environmental problems worldwide. Recently, biotechnology studies have oriented efforts to study algae-bacterium consortia with the aim to understand the mechanisms to find a possible solution in environmental sciences. This study determined the percentage of chromium removal by the alga-bacterium association exposed to a set of different chromium concentrations under controlled in vitro conditions. Wild plants of Bostrychia calliptera associated with bacterial populations were collected from Dagua River, Pacific coast of Colombia, and were monitored in the laboratory. The trial was conducted with synthetic seawater in bioreactors at two chromium levels: 5 and 10mg/L, and four different experimental treatments: i algae

  14. Microhardness evaluation around composite restorations using fluoride-containing adhesive systems Avaliação da microdureza ao redor de restaurações de compósito confeccionadas com sistemas adesivos contendo fluoretos

    Directory of Open Access Journals (Sweden)

    Cláudia Silami de Magalhães

    2005-09-01

    utilizaram sistemas adesivos contendo fluoretos (FCAS, após tratamento dessas superfícies restauradas aos protocolos de ciclagem térmica e pH. Cavidades cilíndricas padronizadas foram preparadas em 175 superfícies de esmalte de fragmentos dentais, os quais foram aleatoriamente divididos em sete grupos (n=25. Quatro grupos utilizaram os FCAS: Optibond Solo (OS; Prime&Bond 2.1 (PB; Syntac Sprint (SS e Tenure Quick (TC. Outros grupos consistiram em restaurações "Sandwich" (STR - ionômero de vidro como base + restauração em composíto ou utilizaram Single Bond com (SB ou sem (SBWC ciclagens. Os sistemas adesivos foram aplicados segundo as instruções dos fabricantes e as cavidades restauradas com compósito microparticulado (Durafill VS. Após o acabamento e polimento, todos grupos foram submetidos a 1.000 ciclos térmicos (5 ºC e 55 ºC e a um protocolo de ciclagem de pH (desmineralização-pH 4,3 e remineralização-pH 7,0, exceto para o grupo SBWC. A microdureza das superfícies de esmalte foi mensurada ao redor das restaurações. Indentações foram feitas nas distâncias de 100, 300 and 450-mm da parede cavitária. Os dados foram analisados pela ANOVA (2 fatores and Teste de Duncan (5%. Os valores médios ± DP da microdureza do esmalte para os grupos foram (Kg/mm²: SBWC: 314,50 ± 55,93ª ; SB: 256,78 ± 62,66b; STR: 253,90 ± 83,6b; TQ: 243,93 ± 68,3b; OS: 227,97 ± 67,1c; PB: 213,30 ± 91,3d; SS: 208,73 ± 86,6d. As médias ± DP de microdureza para as distâncias 150, 300, 450 mm da parede cavitária foram, respectivamente: 234,46 ± 77,81ª; 240,24 ± 85,12ª; 262,06 ± 79,46b. O grupo SBWC que não foi submetido aos protocolos de ciclagem térmica e pH mostrou a maior média de microdureza do esmalte e os FCAS resultaram nos menores valores de microdureza. Na distância de 450 mm da parede cavitária, a microdureza apresentou aumento significativo.

  15. Investigation of alternative phosphating treatments for nickel and hexavalent chromium elimination; Investigacao de tratamentos alternativos de fosfatizacao para eliminacao do niquel e cromo hexavalente

    Energy Technology Data Exchange (ETDEWEB)

    Jazbinsek, Luiz Antonio Rossi

    2014-07-01

    obtained with passivation treatment in niobium containing solution could be considered as a promising alternative to replace passivation with hexavalent chromium ions. Despite of the promising results, adjustments in the baths to obtain stability are still needed and should guide the next steps of the subject of this research. (author)

  16. Evaluación de la seguridad de una suspensión de fosfato de cromo(III para uso en radiosinoviortesis Evaluation of the safety a Chromium (III Phosphate suspension for radiosynoviorthesis

    Directory of Open Access Journals (Sweden)

    Jorge Cruz Arencibia

    2013-03-01

    Full Text Available Objetivo: evaluar la fuga de radiactividad de la cavidad articular después de la administración de suspensiones radiomarcadas de Fosfato de Cromo(III y la probabilidad de inducción de genotoxicidad. Métodos: las suspensiones se obtuvieron según método reportado. Para la evaluación de la fuga articular las suspensiones marcadas se administraron por vía intraarticular en ratas y conejos. El seguimiento se realizó por medición de la actividad retenida por cámara gamma. En los estudios de genotoxicidad se determinó la frecuencia de formación de micronúcleos en eritrocitos de médula ósea de ratas para 2 dosis y 2 tiempos para cada preparado. Resultados: para las suspensiones radiomarcadas en estudio la fuga fue no significativa durante 3 semanas (Objective: to evaluate the leakage of radioactivity after intraarticular administration of radioactive suspensions based on Chromium (III Phosphate as well as the probability of induction of genotoxic effect. Methods: the suspensions were obtained in line with the published procedure. For the articular leakage evaluation, the radioactive suspensions were intraarticulary administered in rats and rabbits. The radioactivity retention was measured by gamma chamber. A comparison with commercial radiopharmaceutical labeled with 32P was made. The genotoxicity studies determined the frequency of micronuclei formation in the rats´ bone marrow erythrocytes by using 2 doses and 2 time intervals for each preparation. Results: the radiolabeled suspensions under evaluation showed that the leakage was not significant during 3 weeks (<3% for the suspension labeled with 51Cr and ~5% in the one labeled with 32P and the advantages of having larger particle preparation were confirmed. For those suspension labeled with 32P and 90Y , no significant difference was seen in the frequency of micronuclei formation for the first time interval, regardless of the administered doses. The micronuclei formation increased

  17. Disgenesia gonadal mixta con fórmula cromosómica 45,X/46,X, (mar. Presentación de una paciente Mixed gonodal dysgenesis with chromosomic formula 45,X/46,X (mar. A case report

    Directory of Open Access Journals (Sweden)

    Pedro González Fernández

    2002-12-01

    Full Text Available Se presentó una paciente con estigmas turnerianos y cariotipo 45,X/46,XX con diagnóstico inicial de síndrome de Turner a la que se le realizó clitoridectomía por hipertrofia del clítoris a los 8 meses de edad. Se reevaluó a los 6 años de edad y se le realizó cariotipo con técnicas de bandas G (GTG con fórmula cromosómica de 45,X/46,X, (cromosoma marcador -mar; dicho marcador dio la impresión de una deleción del cromosoma X desde Xq13 ®Xq ter y Xp22 ®Xp ter. Se completó dicho estudio con técnica molecular de reacción en cadena de la polimerasa (PCR y se identificó el gen SRY en el cromosoma marcador. Se realizó intervención quirúrgica por mínimo acceso y se comprobó ausencia de útero así como trompa en el lado derecho con ausencia de gónada y en el lado opuesto, testículo rudimentario; se planteó el diagnóstico de disgenesia gonadal mixta.A patient with Turner stigmas and karyotype 45,X/46,XX with initial diagnosis of Turner's syndrome is presented. Clitoridectomy was performed due to hypertrophy of the clitoris when she was 8. She was reevaluated at 6 and karyotype was made by using G bands techniques (GTG with chromosomic formula of 45,X/46,X, (marker chromosome -mar; such marker gave the impression of a deletion of chromosome X from Xq13 ®Xq ter and Xp22 ®Xp ter. This study was completed with the molecular technique of polymerase chain reaction (PCR and the SRY gene was identified in the marker chromosome. The patient underwent minimum access surgery and it was proved the absence of uterus and tube on the right side with no gonad and a rudimentary testis on the opposite side. Mixed gonodal dysgenesis was diagnosed.

  18. Diseño Mc. Lean‐Anderson aplicado para obtener recubrimientos de electrodos aleados con carbono, cromo y titanio//Mc. Lean‐Anderson design applied for recovered electrodes obtaining with carbon, chrome and titanium alloys

    Directory of Open Access Journals (Sweden)

    Carlos René Gómez-Pérez

    2013-05-01

    Full Text Available En el trabajo se estudia el comportamiento de electrodos recubiertos destinados al relleno superficial con el proceso de soldadura manual (SMAW, Shielded Metal Arc Welding. Para el diseño experimental se aplican un procedimiento de cálculo para el revestimiento y un plan de mezclas del tipo Mc. Lean-Anderson. En el diseño se conjuga una matriz compuesta por Calcita (26,73 %, Ferrosilicio (19,02 %,Ferromanganeso (16,58 %, Rutilo (26,69 %, Silicato de Potasio (11,70 % y diferentes cargas de aleación conformadas por Grafito (2 ≤ X1 ≤ 10 %, Ferro Cromo (5 ≤ X2 ≤ 35 %, ferrotungsteno (5 ≤ X3 ≤ 10 % y matriz (60 ≤ X4 ≤ 80 %. En el trabajo se ofrecen criterios sobre la selección de los niveles límites a explorar durante el plan experimental, a partir de consideraciones sobre los materiales empleados, sus rangos y el procedimiento de fabricación de los electrodos.Palabras claves: electrodos recubiertos, recubrimientos de electrodos, smaw, diseño de experimentos, relleno superficial._______________________________________________________________________________AbstractIn the present work the behavior of recovered electrodes for superficial filler with Shielded Metal Arc Welding (SMAW process is study. For the experimental design a coating calculation procedure and a Mc. Lean- Anderson type experimental plan are used. On the experimental design a matrix, composed by Calcite (26,73 %, Ferrosilicio (19,02%, Ferromanganese (16,58%, Rutile (26,69%, Potassium Silicate (11,70 %, and a alloy, conformed by Graphite (2 ≤ X1 ≤ 10, Ferro Chromium (5 ≤ X2 ≤ 35 %, ferrotungsteno (5 ≤ X3 ≤ 10 % and matrix (60 ≤ X4 ≤ 80 % is conjugated. In the work some criteria on the selection of the levels limits to explore during the experimental plan are offer, starting from considerations on the materials employees, their ranges and the procedure of production of the electrodes.Key words: recovered electrodes, electrodes coating, smaw

  19. Ion channeling

    International Nuclear Information System (INIS)

    Erramli, H.; Blondiaux, G.

    1994-01-01

    Channeling phenomenon was predicted, many years ago, by stark. The first channeling experiments were performed in 1963 by Davies and his coworkers. Parallely Robinson and Oen have investigated this process by simulating trajectories of ions in monocrystals. This technique has been combined with many methods like Rutherford Backscattering Spectrometry (R.B.S.), Particles Induced X-rays Emission (P.I.X.E) and online Nuclear Reaction (N.R.A.) to localize trace elements in the crystal or to determine crystalline quality. To use channeling for material characterization we need data about the stopping power of the incident particle in the channeled direction. The ratios of channeled to random stopping powers of silicon for irradiation in the direction have been investigated and compared to the available theoretical results. We describe few applications of ion channeling in the field of materials characterization. Special attention is given to ion channeling combined with Charged Particle Activation Analysis (C.P.A.A.) for studying the behaviour of oxygen atoms in Czochralski silicon lattices under the influence of internal gettering and in different gaseous atmospheres. Association between ion channeling and C.P.A.A was also utilised for studying the influence of the growing conditions on concentration and position of carbon atoms at trace levels in the MOVPE Ga sub (1-x) Al sub x lattice. 6 figs., 1 tab., 32 refs. (author)

  20. Ion source

    International Nuclear Information System (INIS)

    1977-01-01

    The specifications of a set of point-shape electrodes of non-corrodable material that can hold a film of liquid material of equal thickness is described. Contained in a jacket, this set forms an ion source. The electrode is made of tungsten with a glassy carbon layer for insulation and an outer layer of aluminium-oxide ceramic material

  1. Nanocompósitos poliméricos de polietileno de alta densidade contendo hidróxidos duplos lamelares intercalados com ânions derivados de corantes azo

    Directory of Open Access Journals (Sweden)

    Ademir Zimmermann

    2014-06-01

    Full Text Available O presente trabalho descreve a síntese e caracterização de hidróxidos duplos lamelares (HDL de Zn/Al na razão molar 2:1, os quais foram intercalados com íons cloreto hidratados e ânions derivados dos corantes azo alaranjado de metila (AM e alaranjado II (AII. Após caracterização, os materiais foram utilizados como cargas em polietileno de alta densidade (PEAD e nanocompósitos foram preparados por extrusão e injeção, seguindo a norma ASTM D638-10. Os teores de cargas variaram de 0,1 até 2% (incluindo-se os sais de sódio dos corantes e os nanocompósitos homogêneos foram avaliados em relação as suas propriedades estruturais, térmicas e mecânicas. De modo geral, após a adição das cargas existe somente uma pequena influência na temperatura de fusão e cristalização do PEAD. Para os HDLs contendo o pigmento intercalado com o ânion do corante AM e sais de sódio de ambos os corantes, as propriedades mecânicas apresentaram leve aumento do módulo e tensão de ruptura e diminuição do alongamento em relação ao polímero puro e um comportamento inverso foi observado para o ânion AII, além do HDL contendo ânions cloreto hidratados.

  2. Avaliação in situ de um dentifrício contendo MFP/DCPD na incorporação de flúor e remineralização do esmalte dental humano

    Directory of Open Access Journals (Sweden)

    KOO Hyun

    1999-01-01

    Full Text Available O objetivo deste estudo foi analisar in situ a efetividade de um dentifrício contendo monofluorfosfato (MFP e sistema abrasivo fosfodicálcio diidratado (DCPD, quando comparado com dentifrício placebo. O estudo foi do tipo cross-over com oito voluntários em duas etapas de 45 dias. Os voluntários utilizaram dispositivo intra-oral palatino de resina acrílica contendo 4 blocos de esmalte com lesão de cárie artificial. Após cada etapa, foi analisada a incorporação de flúor (flúor total em ppm F e microdureza (em Knoop dos blocos de esmalte dental. Os resultados obtidos (média ± E.P. das áreas integradas sob as curvas demonstraram que a concentração de flúor incorporado no esmalte tratado com dentifrício MFP/DCPD foi significativamente maior que no placebo (4.508,55 ± 965,82 e 1.485,51 ± 191,72, respectivamente e os dados de microdureza demonstraram que o dentifrício MFP/DCPD foi capaz de remineralizar o esmalte dental em 34%, enquanto no placebo observou-se perda de 14% de mineral. Assim, os dados obtidos deste estudo demonstraram que o dentifrício MFP/DCPD foi efetivo não apenas na incorporação de flúor no esmalte, mas também na capacidade de remineralizar a lesão de cárie, quando comparado com o placebo.

  3. Ion-ion collisions and ion storage rings

    International Nuclear Information System (INIS)

    Mowat, J.R.

    1988-01-01

    Improved understanding of fundamental ion-ion interactions is expected to emerge from research carried out with ion storage rings. In this short survey the significant advantages and unique features that make stored ions useful targets for collision experiments are reviewed and discussed. It is pointed out that improvements to existing ion-ion experiments, as well as qualitatively new experiments, should occur over the next few years as ion storage rings become available for atomic physics. Some new experiments are suggested which are difficult if not impossible with present-day technology, but which seem feasible at storage rings facilities. (orig.)

  4. Resistência da pele de carpa espelho (Cyprinus carpio specularis curtida pelas técnicas ao cromo e bioleather - DOI: 10.4025/actascianimsci.v26i4.1711 Resistance of the carp mirror skin (Cyprinus carpio specularis tanned by chromium and bioleather technique - DOI: 10.4025/actascianimsci.v26i4.1711

    Directory of Open Access Journals (Sweden)

    José Telmo Agostin Schmidt

    2004-04-01

    Full Text Available O objetivo do trabalho foi avaliar a técnica de curtimento bioleather e o curtimentocom sais de cromo, em peles de carpa espelho (Cyprinus carpio specularis. As peles foram retiradas com o auxílio de uma máquina, identificadas e congeladas. Em seguida, foram curtidas por meio de duas técnicas diferentes. O passo seguinte foi retirada dos corpos de prova, que foram levados para o laboratório, climatizado em torno de 23ºC e umidade relativa, do ar de 50%, conforme NBR 10455 (1988, por 24 horas. Para os testes de resistência à tração, ao alongamento e à determinação da força de rasgamento progressivo, utilizou-se o dinamômetro EMIC. Foram retiradas amostras da região dorsal do couro para análise de microscopia eletrônica de varredura (MEV. As amostras foram secas em ponto crítico com CO2 e metalizadas com íons de ouro-paládio. Em seguida as amostras foram elétron-micrografados com o JEOL-JSM 5410. Observou-se o entrelaçamento e sobreposição das camadas das fibras colágenas, que proporcionam maior resistência ao couro, constatada pelos testes realizados. Os couros curtidos com a técnica bioleather apresentaram maiores valores no teste de tração (20,45 N/mm2 em comparação ao cromo (12,32 N/mm2. Não houve diferença na elongação entre os tratamentos (bioleather = 72,52%; cromo = 84,74%. Para o teste de rasgamento progressivo, o curtimento ao cromo foi superior (26,28 N/mm, comparado ao bioleather (11,96 N/mm. Entretanto, os dois curtimentos podem ser utilizados nas peles dessa espécie de peixe para a confecção de vestuários.The objective of the work was to evaluate the tanning technique to bioleather and with chromium salts, in carp mirror skins (Cyprinus carpio specularis. The skins wore removed by means of a machine, identified and congealed. Next they were tanned by the two techniques. The test bodies wore removed and taken to the laboratory climatized around 23ºC and relative humidity of the 50% air, as ABNT

  5. Ion Beam Extraction by Discrete Ion Focusing

    DEFF Research Database (Denmark)

    2010-01-01

    An apparatus (900) and methods are disclosed for ion beam extraction. In an implementation, the apparatus includes a plasma source (or plasma) (802) and an ion extractor (804). The plasma source is adapted to generate ions and the ion extractor is immersed in the plasma source to extract a fracti...

  6. Níveis de cromo-ácido nicotínico em dietas de suínos em crescimento e terminação Levels of chromium-nicotinic acid in diets for growing-finishing pigs

    Directory of Open Access Journals (Sweden)

    Gustavo Julio Mello Monteiro de Lima

    1999-03-01

    Full Text Available O objetivo deste estudo foi avaliar os efeitos de níveis crescentes de cromo dietético, na forma de ácido nicotínico, sobre o desempenho e nas características de carcaça de suínos. Noventa e seis suínos (Landrace x Large White x Duroc, machos castrados e fêmeas, com peso médio inicial de 25,93±0,57 kg foram distribuídos ao acaso em baias de dois animais do mesmo sexo, segundo um esquema fatorial 6 x 2 (6 níveis de Cr e 2 sexos. Uma dieta basal (0 ppb Cr foi suplementada com 100, 200, 300, 400 e 500 ppb de Cr, na forma de Cr-ácido nicotínico, incluído através do premix vitamínico. Os animais, aos 70 dias de experimento, foram pesados, abatidos, e as carcaças avaliadas utilizando-se a pistola Hennessy e o Método Brasileiro de Classificação de Carcaças. Houve efeito significativo (P0,05 do nível de Cr sobre qualquer dos parâmetros estudados, seja de desempenho ou de avaliação de carcaça por qualquer dos métodos utilizados. A adição de níveis de até 500 ppb de Cr, na forma de Cr-ácido nicotínico, não altera o desempenho e a qualidade de carcaça de suínos em crescimento e em terminação.Ninety-six barrows and gilts (Landrace x Large White x Duroc, with average initial weight of 25.93±0.57 kg, were used in order to evaluate the effects of Cr on performance and carcass characteristics, in a random block design, according to a 6 x 2 factorial arrangement (6 Cr levels x 2 sexes. A basal diet (0 ppb Cr was supplemented with 100, 200, 300, 400 e 500 ppb Cr, as Cr-nicotinic acid, added to the vitamin premix. On the 70th day of the experimental period, all animals were weighted, slaughtered and had their carcass evaluated using Hennessy probe and the Brazilian Carcass Classification Method. There was a significant sex effect (P0.05. The addition of up to 500 ppb Cr in the diet, in the form of Cr-nicotinic acid, did not improve performance and carcass traits of growing-finishing pigs.

  7. Variación espacial y temporal en los contenidos de mercurio, plomo, cromo y materia orgánica en sedimento del complejo de humedales de Ayapel, Córdoba, noroccidente colombiano

    Directory of Open Access Journals (Sweden)

    Alex Fernando Rúa Cardona

    2013-01-01

    Full Text Available Las planicies de inundación atlánticas colombianas están impactadas por la minería aurífera artesanal desarrollada durante las últimas décadas. Sin embargo, la contaminación local por mercurio ha sido comparada con niveles de acción de otras latitudes y no se han incluido otros metales de interés sanitario en las investigaciones. El presente estudio contribuyó al conocimiento de la respuesta geoquímica espacial inducida por el pulso hidrológico y la composición de materia orgánica (MO en el área de influencia del complejo de humedales de Ayapel. Se evaluó la distribución espacial y temporal de mercurio (Hg, plomo (Pb, cromo (Cr y MO en el sedimento reciente del complejo cenagoso de Ayapel y se contrastó con el nivel de referencia de contaminación local por Hg (0,032 μg g-1, Pb (2,39 μg g-1 y Cr (89,58 μg g-1 determinado en la Formación Betulia. Los rangos de los tres metales fueron: 0,008-0,117 μg Hg g-1; 1,090-11,870 μg Pb g-1 y 5,350- 93,430 μg Cr g-1. El Hg mostró la mayor variabilidad espacial (0,083 ± 0,064 μg g-1 y niveles superiores en el afluente del frente de explotación aurífera en la década del 80. En comparación con el nivel de referencia, el 91 % del sedimento reciente presentó enriquecimiento por Pb (6,376 ± 4,048 μg g-1 y el 66,6 % enriquecimiento por Hg. En contraste, el contenido de Cr fue relativamente bajo (96,325 ± 29,868 μg g-1 y presentó tendencia a disminuir de oriente a occidente. El sedimento fue predominantemente inorgánico, con porcentajes medios de cenizas de 88,154 ± 3,822 % y escasos niveles de MO (11,846 ± 3,822 %. Se presume el aumento en la movilidad del Hg debido a la alta tasa de respiración de MO en la zona central del espejo de agua principal de la ciénaga de Ayapel. La resuspensión y migración de sedimentos contaminados es facilitada por la inestabilidad térmica de la columna de agua influenciada por la acción del viento.

  8. PROPRIEDADES E AVALIAÇÃO CATALÍTICA DA ZEÓLITA X NANOMÉTRICA CONTENDO CÁTIONS METILAMÔNIO

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    João G. P. Vicente

    2016-07-01

    Full Text Available The reduction of zeolite particle is one of the main features currently searched; it is due to the catalytic gains that these materials come in some reactions. In this work two faujasite zeolites of type X were evaluated, a micrometer and nanometric. Zeolites in sodium form were exchanged ionically with methylammonium cations. These materials were evaluated as catalysts in the Knoevenagel condensation reaction. Steric impediments restricted the ion exchange in the micrometer zeolite and have become more predominant due to the increase in the volume of cations. In nanometric sample such impediments were less evident due to the reduction of the particles provide greater accessibility to exchangers cations to inaccessible sodium in micrometer zeolite. The best catalytic performances were achieved with zeolites containing the monomethylammonium cation. The increased of the accessibility and diffusion of the reactants and products through the pores of the nanometric zeolite provided the best butyraldehyde conversions independent the exchanger cation

  9. Desenvolvimento e estudos de estabilidade de cremes e géis contendo sementes e extratos do bagaço da uva Isabel (Vitis labrusca L.

    Directory of Open Access Journals (Sweden)

    JOãO RONALDO N. FERREIRA

    2010-12-01

    Full Text Available No cenário mundial, inúmeras indústrias de cosméticos buscam a inovação, utilizando-se de matérias-primas de origens diversificadas, principalmente oriundas de vegetais, representando uma alternativa de substituição de materiais sintéticos por naturais. Com esse intuito, no presente estudo, realizou-se o desenvolvimento e a avaliação da estabilidade de emulsões e géis contendo extratos e sementes do bagaço da uva Isabel (Vitis labrusca L., uma espécie de uva rica em compostos fenólicos e flavonoides com grande atividade antioxidante. Com isso, buscou-se evidenciar o período em que os produtos mantiveram suas propriedades físico-químicas, frente a variações climáticas forçadas em estudos acelerados, durante o período de armazenamento. Foram preparados cremes contendo 5 e 10% de extrato glicólico do bagaço da uva e géis contendo 10% de sementes trituradas, sendo acondicionados em condições ambientais distintas e avaliados, através de testes físico-químicos, no período de 60 dias. Durante esse período, não foram evidenciados sinais de instabilidade físico-química nos cremes analisados frente às condições testadas. No entanto, o gel apresentou leve alteração da cor e do odor, sugerindo a necessidade de estabilização físico-química de seus constituintes naturais com a adição de antioxidantes. Palavras-chave: Antioxidante. Esfoliante. Estabilidade. Uva Isabel. Vitis labrusca L. ABSTRACT Development and testing of the stability of creams and gels containing extracts of the pomace and seeds of Isabel grapes (Vitis labrusca L. Numerous cosmetic companies around the world seek innovation, using raw materials of various origins, mainly derived from plants, as natural alternatives to synthetic materials. With this in mind, this study was carried out to develop and test the stability of emulsions and gels, respectively containing extracts of pomace and seeds of Isabel grape (Vitis labrusca L., a

  10. ION GUN

    Science.gov (United States)

    Dandl, R.A.

    1961-10-24

    An ion gun is described for the production of an electrically neutral ionized plasma. The ion gun comprises an anode and a cathode mounted in concentric relationship with a narrow annulus between. The facing surfaces of the rear portions of the anode and cathode are recessed to form an annular manifold. Positioned within this manifold is an annular intermediate electrode aligned with the an nulus between the anode and cathode. Gas is fed to the manifold and an arc discharge is established between the anode and cathode. The gas is then withdrawn from the manifold through the annulus between the anode and cathode by a pressure differential. The gas is then ionized by the arc discharge across the annulus. The ionized gas is withdrawn from the annulus by the combined effects of the pressure differential and a collimating magnetic field. In a 3000 gauss magnetic field, an arc voltage of 1800 volts, and an arc current of 0.2 amp, a plasma of about 3 x 10/sup 11/ particles/cc is obtained. (AEC)

  11. Heavy ions

    CERN Multimedia

    CERN. Geneva; Antinori, Federico

    2001-01-01

    Colliding two heavy nuclei at ultrarelativistic energies allows to create in the laboratory a bulk system with huge density, pressure and temperature and to study its properties. It is estimated that in Pb-Pb collisions at CERN-SPS we reach over an appreciable volume an energy density which exceeds by more than a factor 20 that of normal nuclear matter. At such densities, the hadrons are so closely packed that they interpenetrate; novel physics phenomena are expected to appear. QCD predicts that under such conditions a phase transition from a system composed of colourless hadrons to a Quark-Gluon Plasma (QGP) should occur. A rich ultrarelativistic heavy-ion physics programme is under way both at BNL-AGS and at CERN-SPS since 1986. The results obtained so far have led CERN to officially announce evidence for a new state of matter last year. A long-range programme of heavy-ion physics at higher energies is under way (BNL-RHIC) and in preparation (CERN-LHC). These lectures are meant as an introduction to the phy...

  12. Heavy ions

    CERN Multimedia

    CERN. Geneva. Audiovisual Unit

    2002-01-01

    Colliding two heavy nuclei at ultrarelativistic energies allows to create in the laboratory a bulk system with huge density, pressure and temperature and to study its properties. It is estimated that in Pb-Pb collisions at CERN-SPS we reach over an appreciable volume an energy density which exceeds by more than a factor 20 that of normal nuclear matter. At such densities, the hadrons are so closely packed that they interpenetrate; novel physics phenomena are expected to appear. QCD predicts that under such conditions a phase transition from a system composed of colourless hadrons to a Quark-Gluon Plasma (QGP) should occur. A rich ultrarelativistic heavy-ion physics programme is under way both at BNL-AGS and at CERN-SPS since 1986. The results obtained so far have led CERN to officially announce evidence for a new state of matter last year. A long-range programme of heavy-ion physics at higher energies is under way (BNL-RHIC) and in preparation (CERN-LHC). These lectures are meant as an introduction to the phy...

  13. Parâmetros sangüíneos de pacu Piaractus mesopotamicus (Holmberg, 1887 alimentados com dietas suplementadas com cromo trivalente em duas densidades de estocagem - DOI: 10.4025/actascianimsci.v29i4.1019 Hematological parameters of pacu Piaractus mesopotamicus (Holmberg, 1887 fed diets supplemented with trivalent chromium in two stocking densities - DOI: 10.4025/actascianimsci.v29i4.1019

    Directory of Open Access Journals (Sweden)

    Flávio Ruas de Moraes

    2008-03-01

    Full Text Available O objetivo deste trabalho foi avaliar os efeitos da suplementação com cromo trivalente (0, 6, 12 e 18 mg kg-1 de ração sobre as variáveis hematológicas de Piaractus mesopotamicus, mantidos em duas densidades de estocagem (4 e 20 kg m-3. Os mantidos na maior densidade e alimentados com dietas suplementadas com 0 e 6 mg de cromo kg-1 apresentaram redução do número de linfócitos circulantes, sugerindo má adaptação a essa condição de alta densidade. Nas dietas suplementadas com 12 e 18 mg kg-1, tal efeito não foi observado, porém verificou-se aumento do número de trombócitos no tratamento com 12 mg de cromo kg-1. A inexistência de diferença significativa entre os tratamentos, aos 30 dias, sugere a adaptação dos peixes ao tipo de alimento e à situação de alta densidade. Portanto, nas condições deste ensaio, a suplementação com 12 e 18 mg de cromo kg-1 é interessante como estratégia alimentar durante 15 dias.This work evaluated the effects of chromium supplementation on the hematological parameters of Piaractus mesopotamicus Holmberg, 1887 maintained in two stocking densities. Fish were fed diets supplemented with 0, 6, 12 and 18 mg trivalent chromium kg-1 dry ration and maintained at 4 and 20 kg m-3. The fish under high stocking density and fed diets supplemented with 0 and 6 mg kg-1 showed reduction in the number lymphocytes, which suggests non-adaptation to this condition of high density. This was not observed in fish fed diets supplemented with 12 and 18 mg chromium kg-1, but an increase in the number of thrombocytes was evident. The lack of difference between treatments after 30 days may suggest a possible adaptation of fish to the situation. It can be added that supplementation with 12 and 18 mg chromium kg-1 is an interesting feeding strategy for a period of 15 days.

  14. DESCOLORIMENTO DE EFLUENTE ASSOCIADO AO TINGIMENTO DE ÁGATAS CONTENDO RODAMINA B COM DIFERENTES COMBINAÇÕES FOTOCATALÍTICAS VIA PROCESSOS OXIDATIVOS AVANÇADOS (POA´s

    Directory of Open Access Journals (Sweden)

    Tiago Bender Wermuth

    2013-12-01

    Full Text Available O tingimento é um dos processos de acabamento das pedras semi-preciosas até a sua comercialização. Este é muito usado na indústria da ágata utilizando elevada demanda de água o que gera uma grande quantidade de águas residuárias, contendo moléculas corantes complexas, como a Rodamina B, que apresenta características de poluente orgânico com ecotoxicidade e genotoxicidade elevadas. Neste trabalho objetivou-se buscar o desenvolvimento de POA’s capazes de degradar os efluentes sintéticos provenientes do tingimento de pedras semi-preciosas contendo o corante Rodamina B (C.I 45170. Para uma melhor eficiência de remoção da Rodamina B, utilizou-se dois métodos distintos de fixação do catalisador utilizado. Primeiramente se trabalho com sílica-gel branca (1-3 mm, Tyvek e posteriormente com o Polietileno de baixa densidade (PEBD. Realizada a preparação dos materiais, investigou-se algumas combinações de métodos como UV/TiO2/SiO2/O3, UV/TiO2/PEBD/O3 bem como, o monitoramento de alguns parâmetros, como pH e a absorbância de amostras sintéticas. Os testes foram realizados em um reator em acrílico composto de lâmpada germicida (SCT – G13/T8/15W, onde se trabalhou com um volume útil de 1 L.Compondo ainda o reator, utilizou-se uma proveta de 1 litro e uma bomba peristáltica. A concentração de Rodamina B utilizada foi de 20 mg L-1. A partir dos resultados obtidos foi possível verificar que a combinação do UV/TiO2/PEBD/O3 mostrou-se ser mais eficiente. Essa combinação proporcionou um valor de constante cinética na ordem de 28,6 x 10-3 min-1. Se comparado aos demais processos investigados, pode-se observar que se teve um aumento do valor de k.

  15. Análise dos medicamentos e interações potenciais de prescrições contendo antimicrobianos dispensados em uma farmácia comunitária de Ijuí / RS

    Directory of Open Access Journals (Sweden)

    Bruna Rodrigues Weber

    2012-01-01

    Full Text Available A resistência bacteriana se constitui em preocupação mundial e a prescrição inadequada de antimicrobianos é um dos fatores que pode influenciar nas suas taxas. O objetivo foi avaliar as prescrições contendo antimicrobianos dispensados em uma farmácia comunitária do município de Ijuí/RS, para identificar os antimicrobianos e osfármacos prescritos em associação, bem como interações medicamentosas potenciais. Métodos: A amostra foi constituída por prescrições retidas no local do estudo, de 28 de novembro de 2010 a 31 de março de 2011, que continham ao menos um antimicrobiano listado no Anexo I da RDC 44/2010. Resultados: Foram analisadas 268 prescrições, contendo 283 antimicrobianos, em 15 prescrições foram prescritos dois produtos. A classe das penicilinas, presente em 30,04% das prescrições, e as quinolonas (23,67% foram os mais prescritos. Em 45,9% das prescrições, pelo menos mais um medicamento foi associado aoantimicrobiano, totalizando 167 medicamentos, sendo principalmente a classe dos analgésicos e antipiréticos (43,11% e dos antiinflamatórios e antirreumáticos não-esteróides (29,94%. Os antiinflamatórios e antirreumáticos não-esteróides estavampresentes em 82,05% das 39 interações medicamentosas potenciais encontradas, sendo que a principal classe de antimicrobianosenvolvida foi a das penicilinas (64,1%. Conclusão: é necessário que os profissionais responsáveis pela prescrição e pela dispensação estejam capacitados para identificar e evitar a presença de interações medicamentosas, proporcionando mais segurança para o usuário e efetividade no tratamento. Entende-se que seja necessário rever e padronizar os critérios de prescrição, dispensação e administração, a fim de racionalizar o uso dos antimicrobianos.

  16. Avaliação de xaropes contendo cloridrato de metoclopramida, pelo método de Bratton-Marshall Evaluation of metoclopramide syrups by Bratton-Marshall method

    Directory of Open Access Journals (Sweden)

    Beatriz Resende Freitas

    2005-06-01

    Full Text Available Atualmente, a maioria dos fármacos apresenta grupamento amínico. Estes quando associados a açúcares redutores ou a outros adjuvantes farmacêuticos contendo carbonila, freqüentemente produzem problemas de estabilidade, comprometendo a idoneidade do produto. A Reação de Maillard pode explicar tal ocorrência. Neste trabalho estudou-se o comportamento de xarope contendo amina aromática, tendo em vista a associação de açúcares e aminas, a Reação de Maillard e problemas de estabilidade. O protótipo escolhido foi o cloridrato de metoclopramida, benzamida com atividade farmacológica antiemética. Amostras dos xaropes de cloridrato de metoclopramida foram mantidas em estufa a 40 °C por seis meses. Em intervalos regulares de tempo alíquotas foram retiradas e submetidas à análise pelo método de Bratton-Marshall, seguida de leitura espectrofotométrica. Não houve grande variação no teor do cloridrato de metoclopramida em relação ao teor de açúcar, sendo que foram preparadas amostras padronizadas dos xaropes de cloridrato de metoclopramida em diferentes concentrações de açúcar. Houve diminuição do teor do cloridrato de metoclopramida, da ordem de 50%, tanto para amostras padronizadas como para amostra comercial.Nowadays, most of the drugs have amine group in their structure. These drugs, when associated to sugar reducers, or other carbonyl excipients frequently produce dark stains or fading. The Maillard reaction can explain such occurrence. In this work, we have studied the behavior of syrups containing aromatic amines. It is known that association of sugars and amines can generate problems of stability. The chosen prototype was the metoclopramide hydrochloride, a benzamide, with anti-emetic pharmacological activity. Samples of the metoclopramide syrups were maintained in stove at 40 °C for six months. In regular time intervals aliquots were removed and submitted to quantitative determination by the Bratton

  17. Adição de cromo hexavalente no crescimento, nodulação e absorção de nutrientes em soja Hexavalent chromium effects on soybeans growth, nitrogen fixation and nutrients absorption

    Directory of Open Access Journals (Sweden)

    Danilo Dufech Castilhos

    2001-12-01

    Full Text Available Foram avaliados os efeitos de doses crescentes de Cr6+ sobre a produção de matéria seca, absorção de nutrientes e fixação biológica de nitrogênio em plantas de soja. Antes da semeadura, as sementes foram tratadas com inóculo turfoso contendo Bradyrhizobium japonicum. As plantas foram cultivadas durante 40 dias em vasos "Leonard" que continha areia na parte superior e solução nutritiva sem nitrogênio na parte inferior. Os tratamentos constaram das seguintes doses de Cr6+ (K2Cr2O7 na solução nutritiva: 0, 5, 10, 20 e 40mg -1. Foi constatado que concentrações de Cr6+ maiores que 5mg -1 diminuíram a produção de matéria seca da parte aérea e radicular da soja, o número e peso de nódulos secos de Bradyrhizobium, como também a fixação biológica de nitrogênio e a absorção de P, K, Ca e Mg. Teores de Cr na parte aérea de plantas de soja superiores a 3,4mg Kg-1 podem ser considerados fitotóxicos.This study was carried out to evaluate the effect of hexavalent chromium on dry matter production, nutrient uptake and nitrogen fixation in soybeans (Glycine max The seeds were inoculated with comercial strains of Bradyrhizobium japonicum (SEMIA 587 and 5019 and the plants were grown in "Leonard Jars" containing washed sand in the upper portion and nutrient solution (without N in the lower. Five Cr6+ concentrations were used: 0, 5, 10, 20 e 40mg -1 in the nutrient solution. Concentrations of Cr6+ above 5mg -1 decreased plants and nodules dry matter production, number of nodules, nitrogen fixation and P, K, Ca e Mg uptake. Chromium concentrations in soybean tops above 3,4mg kg-1 were considered phytotoxic.

  18. Desenvolvimento e avaliação da estabilidade física de loções O/A contendo filtros solares Development and evaluation of physical stability from O/ W lotions containing sunscreens

    Directory of Open Access Journals (Sweden)

    Greice Stefani Borghetti

    2006-12-01

    Full Text Available Os objetivos deste estudo foram desenvolver e avaliar a estabilidade física de loções do tipo O/A contendo 6% (p/p do filtro solar octilmetoxicinamato (OMC ou metilbenzilidenocânfora (MBC. As formulações foram armazenadas em temperatura ambiente durante seis meses e durante este período foram avaliadas com relação às suas características macroscópicas, viscosidade, comportamento reológico, índice de óleo, espalhabilidade e Fator de Proteção Solar (FPS. Os resultados demonstram que as formulações foram estáveis por seis meses. Os valores de FPS foram significativamente (P The objectives of this study were to develop and to evaluate the physical stability of O/W lotions containing 6% (w/w of the sunscreen octylmethoxycinnamate (OMC or methyl benzylidene camphor (MBC. The formulations were stored at room temperature, for six months and during this period its macroscopic characteristics, viscosity and rheological behavior, oil indexes, spreading properties and Sun Protection Factor (SPF were evaluated. The results demonstrate that both formulations were stable for six months. The SPF values were significantly (P < 0.05 higher for MBC formulation. On the other hand, the OMC formulation presented significantly (P < 0.05 higher spreading and lower viscosity values during the storage period.

  19. Characterization of iron phosphate glasses prepared by microwave heating; Obtencao de vidros fosfatos contendo ferro por meio do aquecimento em fornos de microondas

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, Fabio Jesus Moreira de

    2006-07-01

    Phosphate glasses have been investigated since the fifties, because they are relatively easy to prepare, have low melting temperatures (1000 deg C - 1200 deg C), and low glass transition. However, these glasses were very sensitive to humidity, showing a very low chemical durability. Iron phosphate glasses have been prepared by melting inorganic precursors in conventional electric furnaces and induction furnaces. By adding iron, phosphate glasses became chemical resistant and were thought to be used as nuclear waste forms or mechanical resistance fibers. The use of microwaves has been investigated because it makes possible a fast and homogeneous heating of the materials. Microwave promotes the self-heating of the material by the interaction of the external electromagnetic field with the molecules and ions of the material. Niobium phosphate glasses was also produced already through the heating of precursors in microwave ovens. Other glasses containing iron in theirs structure was produced by conventional furnaces and they had your structures analyzed. But even so, it was not still published synthesis of iron phosphate glasses starting from the melting of precursors materials in microwave ovens. In the present work mixtures of (NH{sub 4}){sub 2}HPO{sub 4} and Fe{sub 3}O{sub 4} or (NH{sub 4}){sub 2}HPO{sub 4} and Fe{sub 2}O{sub 3} were exposed to microwave energy with electromagnetic waves of 2,45 GHz. It was proposed that the absorption of this radiation for the material causes the heating from room temperature to melting temperature. The obtained iron phosphate glasses was analyzed by X-ray diffraction, Moessbauer spectroscopy, and Differential Thermal Analysis. Iron phosphate glasses were also produced in electrical furnaces for comparison. (author)

  20. Ion beam monitoring

    International Nuclear Information System (INIS)

    McKinney, C.R.

    1980-01-01

    An ion beam analyzer is specified, having an ion source for generating ions of a sample to be analyzed, means for extracting the sample ions, means for focusing the sample ions into a beam, separation means positioned along the ion beam for selectively deflecting species of ions, and means for detecting the selected species of ions. According to the specification, the analyzer further comprises (a) means for disabling at least a portion of the separation means, such that the ion beam from the source remains undeflected; (b) means located along the path of the undeflected ion beam for sensing the sample ions; and (c) enabling means responsive to the sensing means for automatically re-enabling the separation means when the sample ions reach a predetermined intensity level. (author)

  1. Recoil ion spectroscopy with heavy ions

    International Nuclear Information System (INIS)

    Beyer, H.F.; Mann, R.

    1984-01-01

    This chapter examines the production of very high charge state ions in single ion-atom collisions. Topics considered include some aspects of highly ionized atoms, experimental approaches, the production of highly charged target ions (monoatomic targets, recoil energy distribution, molecular fragmentation, outer-shell rearrangement, lifetime measurements, a comparison of projectile-, target-, and plasma-ion stripping), and secondary collision experiments (selective electron capture, potential applications). The heavy-ion beams for the described experiments were provided by accelerators such as tandem Van de Graaff facility and the UNILAC

  2. Surface negative ion production in ion sources

    International Nuclear Information System (INIS)

    Belchenko, Y.

    1993-01-01

    Negative ion sources and the mechanisms for negative ion production are reviewed. Several classes of sources with surface origin of negative ions are examined in detail: surface-plasma sources where ion production occurs on the electrode in contact with the plasma, and ''pure surface'' sources where ion production occurs due to conversion or desorption processes. Negative ion production by backscattering, impact desorption, and electron- and photo-stimulated desorption are discussed. The experimental efficiencies of intense surface negative ion production realized on electrodes contacted with hydrogen-cesium or pure hydrogen gas-discharge plasma are compared. Recent modifications of surface-plasma sources developed for accelerator and fusion applications are reviewed in detail

  3. Análise morfométrica da carótida de suínos submetidos a angioplastia com ou sem implante de stent de cromo-cobalto Morphometric analysis of swine carotid artery angioplasty with or without cobalt-chromium stent implantation

    Directory of Open Access Journals (Sweden)

    João Luiz de Lara Elesbão

    2010-06-01

    Full Text Available Contexto: A hiperplasia intimal é a reação tardia mais comum decorrente da angioplastia. O uso de stents de cromo-cobalto é bem estudado na circulação coronariana, porém não há muitos estudos que abordem o uso desses stents nas circulações carotídea e periférica. Objetivo: Analisar mediante morfometria a reação intimal presente na artéria carótida de suínos submetidos a angioplastia isoladamente e a angioplastia seguida de implante de stent de cromo-cobalto. Materiais e métodos: Em oito suínos, foi realizada angioplastia da artéria carótida comum direita e angioplastia seguida de implante de um stent de cromo-cobalto na artéria carótida comum esquerda. Após 4 semanas, os animais foram submetidos a eutanásia para a retirada de amostras de tecido arterial e preparo de lâminas histológicas. As imagens das lâminas foram digitalizadas e analisadas por programa de morfometria digital. A análise estatística foi realizada através da média e desvio padrão das áreas em cada grupo, utilizando-se o Teste t de Student. O valor de p Background: Intimal hyperplasia is the most common delayed response to angioplasty. The use of cobalt-chromium stents is well studied in the coronary circulation; however, there are few studies on their use in the carotid and peripheral circulation. Objective: To analyze the intimal reaction in a swine carotid artery undergoing simple angioplasty and angioplasty followed by implantation of cobalt-chromium stent. Materials and methods: We carried out angioplasty in the right common carotid artery and angioplasty with cobalt-chromium stent in the left common carotid artery in eight swine. Four weeks later, all animals were sacrificed for arterial tissue sampling and preparation of histological slides. Slide images were scanned and analyzed using a digital morphometry program. Statistical analysis was performed by mean values and standard deviations of the areas in each group, using the Student's t

  4. Gas phase ion chemistry

    CERN Document Server

    Bowers, Michael T

    1979-01-01

    Gas Phase Ion Chemistry, Volume 1 covers papers on the advances of gas phase ion chemistry. The book discusses the advances in flow tubes and the measurement of ion-molecule rate coefficients and product distributions; the ion chemistry of the earth's atmosphere; and the classical ion-molecule collision theory. The text also describes statistical methods in reaction dynamics; the state selection by photoion-photoelectron coincidence; and the effects of temperature and pressure in the kinetics of ion-molecule reactions. The energy distribution in the unimolecular decomposition of ions, as well

  5. Avaliação do desempenho de frangos de corte alimentados com rações contendo probiótico e diferentes níveis de nucleotídeos

    Directory of Open Access Journals (Sweden)

    João Batista Canevari Bruno

    2012-02-01

    Full Text Available O objetivo deste trabalho foi avaliar o desempenho de frangos de corte alimentados com ração contendo um probiótico comercial e diferentes níveis de nucleotídeos. Foram utilizados 1050 pintos de 01 dia, machos da linhagem Ross 308 totalizando trinta e cinco aves por boxe, em um delineamento inteiramente casualizado com cinco repetições por tratamento. As aves foram criadas até 42 dias de idade, e receberam as rações experimentais a base de milho e farelo de soja contendo 6 níveis de nucleotídeos (0; 100; 200; 300; 400 e 500 gramas por tonelada de ração. Os nucleotídeos foram utilizados na fase inicial (1 a 21 dias e fase de crescimento (22 a 35 dias. Durante a fase final (36 a 42 dias os nucleotídeos foram removidos da ração . Houve melhora linear no desempenho dos frangos no período de 1 a 21 dias, indicando que, quanto maior o nível de nucleotídeos na dieta, maior o peso corporal das aves. A conversão alimentar também melhorou linearmente nesse período à medida que aumentou o nível de nucleotídeos na ração. O peso no período de 35 dias, também teve um comportamento linear, semelhante ao período de 1 a 21 dias, indicando que, o nível de nucleotídeos na ração melhorou o desempenho. A concentração plasmática de acido úrico demonstrou efeito quadrático no período de 1 a 21 dias, indicando 231,59 gramas de nucleotídeos por tonelada de ração, como o melhor, em níveis mínimos de ácido úrico, por outro lado, no período de 35 dias de idade, estimou-se o nível de 208,99 g de nucleotídeos por tonelada de ração; como o melhor em níveis mínimos de ácido úrico no sangue. No período final (35 a 42 dias e período total (1 a 42 dias de idade não foi possível o observar efeito dos contrastes testados neste trabalho.

  6. Produção de mudas de tomateiro em substratos contendo fibra de coco e pó de rocha Tomato seedlings production using substrates with coconut fiber and rock waste

    Directory of Open Access Journals (Sweden)

    Regynaldo A Sampaio

    2008-12-01

    Full Text Available Com o objetivo de avaliar proporções dos resíduos fibra de coco (FC e pó de rocha de granito (RG como substratos na produção de mudas de tomateiro, cultivar Kada Gigante, realizou-se um experimento em casa de vegetação na UFMG-ICA. Foi utilizado o delineamento experimental em blocos ao acaso, com quatro repetições. Os tratamentos foram constituídos por uma testemunha e seis proporções de fibra de coco (FC e pó de rocha de granito (RG: T1 - Substrato comercial Hortimix®; T2 - 0% FC + 100% RG; T3 - 20% FC + 80% RG; T4 - 40% FC + 60% RG; T5 - 60% FC + 40% RG; T6 - 80% FC + 20% RG; T7 - 100% FC + 0% RG. O cultivo foi feito em bandeja de poliestireno expandido com células de 3,5 x 3,5 x 5,0 cm. Foram avaliados o diâmetro do coleto, a altura da planta, o índice de velocidade de emergência, a percentagem de emergência e a massa fresca e seca da parte aérea e da raiz. Em praticamente todas as características avaliadas o substrato comercial foi superior aos substratos contendo fibra de coco e pó de rocha. Considerando-se apenas os substratos contendo fibra de coco e pó de rocha, as mudas com melhores características foram obtidas com a mistura de aproximadamente 70% em volume de fibra de coco.A greenhouse experiment was carried out to evaluate the ratio of coconut fiber and rock waste, in the tomato seedling production (cultivar Kada Gigante, in Montes Claros, Brazil. The experimental design was of randomized complete blocks with four replicates. The treatments were composed of a control and six ratios of coconut fiber (FC and rock waste (RG: T1 - Commercial Substrate Hortimix®; T2 - 0% FC + 100% RG; T3 - 20% FC + 80% RG; T4 - 40% FC + 60% RG; T5 - 60% FC + 40% RG; T6 - 80% FC + 20% RG; T7 - 100% FC + 0% RG. The cultivation was done in polystyrene trays with cells of 3.5 x 3.5 x 5,0 cm. Stem diameter, seedling height, emergency speed index, emergency percentage, root and aerial part of fresh and dry matter were evaluated. In

  7. Laser ion sources

    Energy Technology Data Exchange (ETDEWEB)

    Bykovskij, Yu

    1979-02-01

    The characteristics a laser source of multiply-ionized ions are described with regard to the interaction of laser radiation and matter, ion energy spectrum, angular ion distribution. The amount of multiple-ionization ions is evaluated. Out of laser source applications a laser injector of multiple-ionization ions and nuclei, laser mass spectrometry, laser X-ray microradiography, and a laser neutron generators are described.

  8. Estudo de propriedades físico-químicas envolvidas no processo de compactação de uma formulação experimental contendo zidovudina

    Directory of Open Access Journals (Sweden)

    Tatiana Angiolucci

    2012-04-01

    Full Text Available Estudo das propriedades físico-químicas envolvidos no processo de compactação de uma formulação experimental contendo como fármaco modelo a zidovudina. O objetivo foi caracterizar o comportamento físico-químico de comprimidos produzidos por compressão direta usando-se diferentes pressões de compactação. Nas análises foram empregadas metodologias convencionais e não convencionais. A metodologia não convencional foi o uso da técnica da atenuação de raios-gama na determinação da porosidade. As metodologias convencionais utilizadas foram os testes de friabilidade, dureza e dissolução. Os modelos teóricos utilizados para explicar o comportamento físico-químico da formulação sob compressão são os proposto por Heckel e Walker. Os estudos mostraram que o processo de densificação é governado principalmente por deformações do tipo plásticas e pressões em torno de 246MPa são suficientes para induzir deformação plástica e consolidação do sistema compactado. Os resultados da análise de Walker indicam que a formulação tem propriedades de compressão que podem ser melhoradas.

  9. Consumo e digestibilidade aparente de minerais em dietas para cães contendo polpa de citros e folha de alfafa Intake and apparent digestibility of the minerals in canine diets containing citrus pulp and alfalfa leaf

    Directory of Open Access Journals (Sweden)

    Maria Isabel Fonseca Rocha Malafaia

    2002-10-01

    Full Text Available O consumo diário e a digestibilidade aparente de macro e microminerais, foram determinados em cadelas que receberam uma dieta controle (R0, acrescida de 10 (R10 ou 20% (R20 de uma mistura contendo polpa de citros (PC e folhas de alfafa desidratadas. A digestibilidade aparente dos minerais foi estimada por meio da quantidade do elemento mineral ingerido, subtraída daquela eliminada nas fezes. A medida que a ingestão de fibra dietética aumentou, o consumo de MS (em g/kgPV diminuiu e as digestibilidades aparentes do Ca, P, Mg, Na, Zn, Fe e Cu foram maiores. A exceção foi para o Mn, cuja digestibilidade reduziu-se com o aumento da ingestão de fibra. Apenas para o K, não se verificou alteração na sua digestibilidade em função do nível de fibra na dieta.The daily intake and the apparent digestibility of macro and microminerals were determined in bitches fed either a control diet (R0 or the same diet but containing 10% (R10 or 20% (R20 of a mixture composed of citrus pulp and dehydrated alfalfa leaf. The apparent digestibility was estimated as being the amount of a mineral element ingested minus the amount of the element quantified in the feces. Once the dietary fiber intake increased, the intake of dry matter (in g/kgLW reduced and the Ca, P, Mg, Na, Zn, Fe and Cu apparent digestibility increased. Exception was the Mn digestibility reduction as the fiber intake increased. Only the K digestibility was not influenced by the diet fiber level.

  10. Emulsion of systems containing egg yolk, polysaccharides and vegetable oil Emulsão de sistemas contendo gema de ovo, polissacarídeos e óleo vegetal

    Directory of Open Access Journals (Sweden)

    Clitor Junior Fernandes de Souza

    2012-10-01

    Full Text Available This work characterizes the emulsifying properties of systems containing egg yolk (0.1; 1.0 and 2.5 % w/v and polysaccharides (xanthan gum, carrageen, pectin and carboxymethylcellulose and three different vegetable oils (sunflower, canola, and palm oils. Emulsifying activity and emulsion stability were measured of each combination and it was found the effect of the oil on emulsion stability correlated to the amount of monounsaturated fatty acid. Additionally, increased egg yolk concentration increased emulsifying activity by reducing coalescence of oil droplets. Lastly, 2.5% egg yolk and 0.2% polysaccharide generated emulsions with high emulsifying activity, excellent stability, and droplet size of 4.32 µm.Neste trabalho, caracterizam-se as propriedades emulsificantes de sistemas contendo gema de ovo (0,1; 1,0 e 2,5% m/v, polissacarídeos (goma xantana, carragena, pectina e carboximetilcelulose e três diferentes óleos vegetais (óleos de palma, canola e girassol. Atividade emulsificante e estabilidade da emulsão foram medidas para cada combinação e verificou-se o efeito do óleo sobre a estabilidade da emulsão correlacionada com a quantidade de ácido graxo monoinsaturado. Além disso, a concentração de gema de ovo aumentou a atividade emulsificante, reduzindo a coalescência das gotículas de óleo. Por último, 2,5 % de gema de ovo e 0,2% de polissacarídeo formaram emulsões com alta atividade emulsificante, excelente estabilidade e tamanho de gota de 4,32 µm.

  11. Crescimento, esporulação e viabilidade de fungos entomopatogênicos em meios contendo diferentes concentrações do óleo de nim (Azadirachta indica

    Directory of Open Access Journals (Sweden)

    Marques Renata Paro

    2004-01-01

    Full Text Available A associação de extratos de origem vegetal com fungos entomopatogênicos pode aumentar a eficiência do controle biológico de pragas, reduzir custos e impactos ambientais. No presente trabalho, avaliou-se, através da concentração inibitória mínima, o efeito do óleo de nim (NIM-I-GO sobre o crescimento, esporulação e viabilidade de Metarhizium anisopliae, Beauveria bassiana e Paecilomyces farinosus. Utilizou-se o meio BDA, contendo diferentes concentrações de óleo de nim (C1: 5% de óleo de nim, e sucessivamente concentrações iguais a fraction one-half da concentração anterior, até C11: 0,0048% de óleo de nim. O óleo de nim reduziu o crescimento de colônias de B. bassiana e P. farinosus, que não diferiram significativamente do controle apenas na concentração C11, mas para M. anisopliae o mesmo efeito foi observado com 0,039% de óleo de nim (C8. A esporulação também foi significativamente reduzida pelo óleo de nim, exceto na concentração C11 para B. bassiana; contudo, não se verificou efeito do óleo na viabilidade de esporos dos fungos.

  12. Validação de método analítico para doseamento de flavonoides totais em cápsulas contendo extrato seco de Passiflora incarnata L.

    Directory of Open Access Journals (Sweden)

    Juliana Ziliotto

    2012-08-01

    Full Text Available Este trabalho teve como objetivo desenvolver e validar metodologia analítica por espectrofotometria no UV para a quantificação de flavonóides totais, expressos em vitexina, em cápsulas contendo extrato seco de Passiflora incarnata L. O método foi desenvolvido a partir da metodologia de doseamento de flavonóides totais descrita na monografia do extrato seco de P. incarnata L, disponível na Farmacopeia Britânica (2010. A validação da metodologia analítica de doseamento foi realizada de acordo com a Anvisa RE N° 899/2003 e diretrizes da International Conference on Harmonization. O método mostrou-se seletivo, pois não houve interferência dos adjuvantes na leitura das absorbâncias nas soluções analisadas. Apresentou coeficiente de correlação linear (r de 0,9999, confirmando a linearidade do método. Os valores de desvio padrão relativo, obtidos tanto para precisão, nos níveis de repetibilidade e precisão intermediária, quanto para exatidão não excederam o máximo de 15% determinado nos critérios de aceitação para métodos bioanalíticos, considerando a complexidade da matéria-prima vegetal.

  13. Efeito do óleo de mamona em composições de borracha natural contendo sílica Effects from the castor oil on silica-filled natural rubber compounds

    Directory of Open Access Journals (Sweden)

    Helson M. da Costa

    2004-03-01

    Full Text Available O potencial do óleo de mamona como um ativador para a vulcanização de composições de borracha natural (NR contendo sílica foi investigado. Utilizando-se um planejamento de experimentos adequado, manteve-se a concentração de sílica e outros aditivos constantes enquanto as quantidades de ácido esteárico, óleo de mamona e poli(etileno-glicol foram variadas. A cura foi conduzida em um reômetro de disco oscilatório TI-100 e a variável de controle escolhida foi a resistência à tração. Os resultados demonstraram que o óleo de mamona sozinho não exerce influência considerável sobre o desempenho mecânico da borracha natural em presença de sílica.The possible use of castor oil fatty acid as an activator for the vulcanization reaction in silica-filled natural rubber (NR compounds was investigated. The design and analysis of the experiments were carried out by keeping constant the concentration of silica and the other ingredients while the amounts of stearic acid, castor oil and poly(ethylene glycol were varied. Cure was carried out on a TI-100 oscillating disk rheometer, and the tensile strength was chosen as the control variable. The results show that the addition of castor oil does not significantly change the mechanical performance of silica-filled natural rubber compounds.

  14. EMBALAGEM PLÁSTICA CONTENDO POLIAMIDA 6 PARA PRODUTOS CÁRNEOS E QUEIJOS: MIGRAÇÃO DE CAPROLACTAMA E EFEITO DA IRRADIAÇÃO. UMA REVISÃO

    Directory of Open Access Journals (Sweden)

    Juliana Silva FÉLIX

    2009-06-01

    Full Text Available

    As poliamidas são muito usadas como embalagem de alimentos, principalmente devido à resistência mecânica, térmica, química e à gordura, às boas propriedades de barreira e por serem termoformáveis. Filmes mono ou multicamadas contendo poliamida 6 são usados especialmente no acondicionamento de produtos cárneos e queijos. A caprolactama, monômero da poliamida 6, assim como oligômeros de baixa massa molecular, aditivos, compostos de degradação, entre outros, também podem estar presentes nas embalagens e têm potencial para migrar para o alimento em contato. O emprego da poliamida 6 como embalagem plástica para contato com alimentos é permitido no Brasil, na Europa e nos Estados Unidos, estando também autorizado o uso para contato com alimentos pré-embalados que serão submetidos à radiação ionizante. Apesar da baixa toxicidade, a presença de caprolactama em alimentos é considerada indesejável. A migração da caprolactama de embalagens de poliamida para alimentos e simulante de alimentos tem sido relatada em alguns estudos. Os níveis de caprolactama migrados variam dependendo da composição da embalagem, do tempo e temperatura de contato, do tipo de simulante ou alimento, entre outros fatores. A migração de caprolactama de embalagens de poliamida irradiadas está ainda relacionada à dose de irradiação, mas de maneira geral, mostra tendência de redução com o aumento da dose.

  15. PADRONIZAÇÃO DE EXCIPIENTES PARA MANIPULAÇÃO DE CÁPSULAS GELATINOSAS DURAS CONTENDO EXTRATO SECO DE VALERIANA (Valeriana officinalis, PRODUZIDAS NO PROJETO FARMÁCIA VIVA EM SOBRAL-CE

    Directory of Open Access Journals (Sweden)

    Antônio Neudimar Bastos Costa

    2016-07-01

    Full Text Available O Projeto Farmácia Viva é o primeiro projeto de assistência social farmacêutica desenvolvido no Brasil baseado no emprego científico de plantas medicinais. Dentre as formulações padronizadas a partir de cápsulas gelatinosas duras, destacam-se as cápsulas contendo Extrato Seco de Valeriana. Para manipulação dessas cápsulas, é necessária uma quantidade adicional de excipientes, que possuem papel importante na qualidade, segurança e no desempenho do medicamento. O objetivo deste estudo é padronizar excipientes para formulação fitoterápica em cápsulas manipuladas no Projeto Farmácia Viva. A metodologia seguida foi por meio de análise bibliográfica sobre os variados excipientes e fitoterápicos e análise de bulas de medicamentos para posterior sugestão de padronização. Foram manipuladas 30 cápsulas e submetidas ao controle da qualidade, onde foram avaliados o peso médio, limite de variação, coeficiente de variação, desvio padrão e variação do conteúdo teórico das cápsulas. A formulação de Valeriana proposta teve como excipientes escolhidos o estearato de magnésio (0,5 % como lubrificante, o dióxido de silício coloidal (1,0 % como deslizante, o talco farmacêutico (1,0 % como adsorvente, o amido farmacêutico (73,0 % como um diluente hidrofóbico, lactose monohidratada (24,5 % como um diluente hidrofílico. Todos os resultados do controle da qualidade obtidos atenderam as especificações farmacopeicas.

  16. Análise comparativa de embalagens secundárias e bulas de medicamentos contendo Panax ginseng C. A. Meyer A comparative analysis of inner wrapping and package inserts for medicines containing Panax ginseng C. A. Meyer

    Directory of Open Access Journals (Sweden)

    Mariangela Tirico Auricchio

    2007-10-01

    Full Text Available As informações contidas nas bulas e embalagem de medicamentos de diferentes fabricantes contendo Panax ginseng foram analisadas comparativamente com os dados encontrados na literatura científica. Observaram-se bulas longas, com várias informações em relação às indicações de uso, muitas das quais sem comprovação em humanos, e todas foram deficitárias em relação aos .efeitos adversos e interações medicamentosas. Foi observada falta de padronização quanto às posologias, em relação tanto ao extrato seco, quanto ao teor dos ginsenosídeos presentes. Constatou-se a falta de homogeneidade nas informações aos usuários sobre indicações de uso, efeitos adversos e interações medicamentosas entre as oito amostras estudadas.The information provided on package inserts and inner wrapping of eight products containing Panax ginseng from different manufacturers was compared internally and checked against data from the scientific literature. The inserts included extensive text, containing abundant information on indications for use, but no scientific evidence in humans. All the inserts lacked information on potential adverse effects and drug interaction. There was no standardization as to dose regimens, particularly in relation to the dried extract and ginsenoside concentration. The eight inserts thus showed no concern over standardization, indication for usage, or possible side effects and drug interactions.

  17. Estudo de toxicologia clínica de um fitoterápico contendo Passiflora incarnata L., Crataegus oxyacantha L., Salix alba L. em voluntários saudáveis

    Directory of Open Access Journals (Sweden)

    Demétrius F. Nascimento

    Full Text Available O Pasalix® é um produto fitoterápico contendo uma associação de três plantas medicinais: Passiflora incarnata, Salix alba e Crataegus oxyacantha. Sua principal indicação é para o tratamento da ansiedade e insônia. O objetivo desse estudo foi avaliar a toxicologia clínica dessa formulação em voluntários saudáveis. Para isso realizou-se um ensaio clínico não aleatório, aberto, com 24 voluntários sadios do sexo masculino, que receberam ambulatorialmente dois (2 comprimidos revestidos do fitoterápico duas vezes ao dia, durante 28 dias ininterruptos. Os voluntários foram incluídos no estudo somente quando considerados saudáveis após avaliação clínica, exame físico e exames laboratoriais que antecederam o estudo. A avaliação laboratorial incluiu análise hematológica, bioquímica e sorológica. A avaliação clínica e laboratorial foi repetida após a 1ª, 2ª, 3ª e 4ª semanas de tratamento e 7 dias após a última administração. O Pasalix® foi bem tolerado pelos 24 voluntários não apresentando eventos adversos graves. Os exames clínicos, eletrocardiográficos e laboratoriais efetuados antes, durante e após o ensaio não evidenciaram sinais de toxicidade nos diversos órgãos e sistemas avaliados, confirmando a segurança da preparação para utilização em ensaios de eficácia terapêutica.

  18. Ion Beam Propulsion Study

    Science.gov (United States)

    2008-01-01

    The Ion Beam Propulsion Study was a joint high-level study between the Applied Physics Laboratory operated by NASA and ASRC Aerospace at Kennedy Space Center, Florida, and Berkeley Scientific, Berkeley, California. The results were promising and suggested that work should continue if future funding becomes available. The application of ion thrusters for spacecraft propulsion is limited to quite modest ion sources with similarly modest ion beam parameters because of the mass penalty associated with the ion source and its power supply system. Also, the ion source technology has not been able to provide very high-power ion beams. Small ion beam propulsion systems were used with considerable success. Ion propulsion systems brought into practice use an onboard ion source to form an energetic ion beam, typically Xe+ ions, as the propellant. Such systems were used for steering and correction of telecommunication satellites and as the main thruster for the Deep Space 1 demonstration mission. In recent years, "giant" ion sources were developed for the controlled-fusion research effort worldwide, with beam parameters many orders of magnitude greater than the tiny ones of conventional space thruster application. The advent of such huge ion beam sources and the need for advanced propulsion systems for exploration of the solar system suggest a fresh look at ion beam propulsion, now with the giant fusion sources in mind.

  19. Negative ion sources

    International Nuclear Information System (INIS)

    Ishikawa, Junzo; Takagi, Toshinori

    1983-01-01

    Negative ion sources have been originally developed at the request of tandem electrostatic accelerators, and hundreds of nA to several μA negative ion current has been obtained so far for various elements. Recently, the development of large current hydrogen negative ion sources has been demanded from the standpoint of the heating by neutral particle beam injection in nuclear fusion reactors. On the other hand, the physical properties of negative ions are interesting in the thin film formation using ions. Anyway, it is the present status that the mechanism of negative ion action has not been so fully investigated as positive ions because the history of negative ion sources is short. In this report, the many mechanisms about the generation of negative ions proposed so far are described about negative ion generating mechanism, negative ion source plasma, and negative ion generation on metal surfaces. As a result, negative ion sources are roughly divided into two schemes, plasma extraction and secondary ion extraction, and the former is further classified into the PIG ion source and its variation and Duoplasmatron and its variation; while the latter into reflecting and sputtering types. In the second half of the report, the practical negative ion sources of each scheme are described. If the mechanism of negative ion generation will be investigated more in detail and the development will be continued under the unified know-how as negative ion sources in future, the development of negative ion sources with which large current can be obtained for any element is expected. (Wakatsuki, Y.)

  20. Ion sources for heavy ion fusion

    International Nuclear Information System (INIS)

    Yu, S.S.; Eylon, S.; Chupp, W.

    1995-09-01

    The development of ion sources for heavy ion fusion will be reported with particular emphasis on a recently built 2 MV injector. The new injector is based on an electrostatic quadrupole configuration, and has produced pulsed K + ions of 950 mA peak from a 6.7 inch curved alumino silicate source. The ion beam has reached 2.3 MV with an energy flatness of ±0.2% over 1 micros. The measured normalized edge emittance of less than 1 π mm-mr is close to the source temperature limit. The design, construction, performance, and comparisons with three-dimensional particle-in-cell simulations will be described

  1. Electron Beam Ion Sources

    CERN Document Server

    Zschornacka, G.; Thorn, A.

    2013-12-16

    Electron beam ion sources (EBISs) are ion sources that work based on the principle of electron impact ionization, allowing the production of very highly charged ions. The ions produced can be extracted as a DC ion beam as well as ion pulses of different time structures. In comparison to most of the other known ion sources, EBISs feature ion beams with very good beam emittances and a low energy spread. Furthermore, EBISs are excellent sources of photons (X-rays, ultraviolet, extreme ultraviolet, visible light) from highly charged ions. This chapter gives an overview of EBIS physics, the principle of operation, and the known technical solutions. Using examples, the performance of EBISs as well as their applications in various fields of basic research, technology and medicine are discussed.

  2. Ions and light

    CERN Document Server

    Bowers, Michael T

    2013-01-01

    Gas Phase Ion Chemistry, Volume 3: Ions and Light discusses how ions are formed by electron impact, ion-molecule reactions, or electrical discharge. This book discusses the use of light emitted by excited molecules to characterize either the chemistry that formed the excited ion, the structure of the excited ion, or both.Organized into 10 chapters, this volume begins with an overview of the extension of the classical flowing afterglow technique to include infrared and chemiluminescence and laser-induced fluorescence detection. This text then examines the experiments involving molecules that ar

  3. Negative-ion states

    International Nuclear Information System (INIS)

    Compton, R.N.

    1982-01-01

    In this brief review, we discuss some of the properties of atomic and molecular negative ions and their excited states. Experiments involving photon reactions with negative ions and polar dissociation are summarized. 116 references, 14 figures

  4. Quadrupole Ion Traps

    Indian Academy of Sciences (India)

    to do precision spectroscopic measurements on these ions. ... Bonn, investigated the non-magnetic quadrupole mass filter, .... the details of which will be discussed in the subse- ... the radial plane the ion undergoes a circular motion with the.

  5. Negative ion detachment processes

    International Nuclear Information System (INIS)

    Champion, R.L.; Doverspike, L.D.

    1990-10-01

    This paper discusses the following topics: H - and D - collisions with atomic hydrogen; collisional decomposition of SF 6 - ; two-electron loss processes in negative ion collisions; associative electron detachment; and negative ion desorption from surfaces

  6. Ion sources in AMS

    International Nuclear Information System (INIS)

    Iyer, Indira S.

    1997-01-01

    Accelerator Mass Spectrometry (AMS) entails the sputtering of various samples in an ion source followed by high precision mass analysis of the sputtered ion species in a Tandem Electrostatic Accelerator. A brief account is given

  7. Single Cathode Ion Thruster

    Data.gov (United States)

    National Aeronautics and Space Administration — Objective is to design an electrostatic ion thruster that is more efficient, simpler, and lower cost than the current gridded ion thruster. Initial objective is to...

  8. Applications of decelerated ions

    International Nuclear Information System (INIS)

    Johnson, B.M.

    1985-03-01

    Many facilities whose sole purpose had been to accelerate ion beams are now becoming decelerators as well. The development and current status of accel-decel operations is reviewed here. Applications of decelerated ions in atomic physics experiments are discussed

  9. Fundamentals of ion exchange

    International Nuclear Information System (INIS)

    Townsend, R.P.

    1993-01-01

    In this paper the fundamentals of ion exchange mechanisms and their thermodynamics are described. A range of ion exchange materials is considered and problems of communication and technology transfer between scientists working in the field are discussed. (UK)

  10. Gas phase ion chemistry

    CERN Document Server

    Bowers, Michael T

    1979-01-01

    Gas Phase Ion Chemistry, Volume 2 covers the advances in gas phase ion chemistry. The book discusses the stabilities of positive ions from equilibrium gas-phase basicity measurements; the experimental methods used to determine molecular electron affinities, specifically photoelectron spectroscopy, photodetachment spectroscopy, charge transfer, and collisional ionization; and the gas-phase acidity scale. The text also describes the basis of the technique of chemical ionization mass spectrometry; the energetics and mechanisms of unimolecular reactions of positive ions; and the photodissociation

  11. Ion mobility spectrometry

    CERN Document Server

    Eiceman, GA

    2005-01-01

    Key Developments for Faster, More Precise Detection Capabilities Driven by the demand for the rapid and advanced detection of explosives, chemical and biological warfare agents, and narcotics, ion mobility spectrometry (IMS) undergone significant refinements in technology, computational capabilities, and understanding of the principles of gas phase ion chemistry and mobility. Beginning with a thorough discussion of the fundamental theories and physics of ion mobility, Ion Mobility Spectrometry, Second Edition describes the recent advances in instrumentation and newly

  12. Intense ion beam generator

    International Nuclear Information System (INIS)

    Humphries, S. Jr.; Sudan, R.N.

    1977-01-01

    Methods and apparatus for producing intense megavolt ion beams are disclosed. In one embodiment, a reflex triode-type pulsed ion accelerator is described which produces ion pulses of more than 5 kiloamperes current with a peak energy of 3 MeV. In other embodiments, the device is constructed so as to focus the beam of ions for high concentration and ease of extraction, and magnetic insulation is provided to increase the efficiency of operation

  13. Ion sources for accelerators

    International Nuclear Information System (INIS)

    Alton, G.D.

    1974-01-01

    A limited review of low charge sate positive and negative ion sources suitable for accelerator use is given. A brief discussion is also given of the concepts underlying the formation and extraction of ion beams. Particular emphasis is placed on the technology of ion sources which use solid elemental or molecular compounds to produce vapor for the ionization process

  14. Negative Ion Density Fronts

    International Nuclear Information System (INIS)

    Igor Kaganovich

    2000-01-01

    Negative ions tend to stratify in electronegative plasmas with hot electrons (electron temperature Te much larger than ion temperature Ti, Te > Ti ). The boundary separating a plasma containing negative ions, and a plasma, without negative ions, is usually thin, so that the negative ion density falls rapidly to zero-forming a negative ion density front. We review theoretical, experimental and numerical results giving the spatio-temporal evolution of negative ion density fronts during plasma ignition, the steady state, and extinction (afterglow). During plasma ignition, negative ion fronts are the result of the break of smooth plasma density profiles during nonlinear convection. In a steady-state plasma, the fronts are boundary layers with steepening of ion density profiles due to nonlinear convection also. But during plasma extinction, the ion fronts are of a completely different nature. Negative ions diffuse freely in the plasma core (no convection), whereas the negative ion front propagates towards the chamber walls with a nearly constant velocity. The concept of fronts turns out to be very effective in analysis of plasma density profile evolution in strongly non-isothermal plasmas

  15. Nanostructures by ion beams

    Science.gov (United States)

    Schmidt, B.

    Ion beam techniques, including conventional broad beam ion implantation, ion beam synthesis and ion irradiation of thin layers, as well as local ion implantation with fine-focused ion beams have been applied in different fields of micro- and nanotechnology. The ion beam synthesis of nanoparticles in high-dose ion-implanted solids is explained as phase separation of nanostructures from a super-saturated solid state through precipitation and Ostwald ripening during subsequent thermal treatment of the ion-implanted samples. A special topic will be addressed to self-organization processes of nanoparticles during ion irradiation of flat and curved solid-state interfaces. As an example of silicon nanocrystal application, the fabrication of silicon nanocrystal non-volatile memories will be described. Finally, the fabrication possibilities of nanostructures, such as nanowires and chains of nanoparticles (e.g. CoSi2), by ion beam synthesis using a focused Co+ ion beam will be demonstrated and possible applications will be mentioned.

  16. Artigo revisão: atuação dos antioxidantes em refratários contendo carbono Review article: performance of the antioxidants in carbon containing refractories

    Directory of Open Access Journals (Sweden)

    A. P. Luz

    2007-12-01

    Full Text Available Os materiais refratários contendo carbono têm despertado grande atenção nos últimos anos, uma vez que são amplamente utilizados na indústria siderúrgica em virtude de suas excelentes propriedades. A presença do carbono nos refratários contribui para o aumento da resistência ao choque térmico, da energia de fratura e da resistência ao ataque por escória. Entretanto, a principal desvantagem do seu uso é a sua alta susceptibilidade a oxidação. Com o objetivo de manter o carbono presente na estrutura do material refratário o maior tempo possível, algumas medidas são requeridas para reduzir sua oxidação sob condições operacionais. Desta forma, o uso de substâncias conhecidas como antioxidantes tem sido extensivamente estudado. Os principais antioxidantes, suas características e formas de atuação são abordados nesta revisão. A formação de novos compostos devido à reação entre os antioxidantes com o carbono, nitrogênio, oxigênio e o próprio material refratário pode provocar um preenchimento parcial dos poros e redução da taxa de interdifusão dos gases, havendo assim a prevenção da oxidação do carbono presente no refratário.Carbon containing refractories have received great attention over the last years, as they are widely used in the steel making industry due to their better properties, such as: higher thermal shock resistance, fracture energy and slag resistance. However, their main disadvantage is the carbon oxidation. Aiming to keep carbon in the structure of the refractory material some actions are required in order to reduce its oxidation under operational conditions. Therefore, the use of materials known as antioxidants has been extensively studied. The main antioxidants, their characteristics and performance are discussed in the present review article. The formation of new compounds due to the reaction of the antioxidants with carbon, nitrogen, oxygen and the refractory material can induce a pore

  17. Desempenho de bovinos jovens alimentados com dietas contendo grão úmido de milho ou sorgo Performance of young cattle fed diets with high moisture corn or sorghum

    Directory of Open Access Journals (Sweden)

    Mauricio Scoton Igarasi

    2008-03-01

    Full Text Available Objetivou-se com este estudo verificar diferenças no desempenho de animais jovens alimentados com dietas contendo grão úmido de milho ou sorgo. Utilizaram-se dois tratamentos experimentais, nos quais a dieta total possuía, como ingrediente energético principal, grão úmido de milho (TMU ou grão úmido de sorgo (TSU. Noventa novilhos inteiros F1 Red Angus ´ Nelore, com 8 meses de idade e 240 kg de peso vivo médio inicial, foram alimentados durante 172 dias e divididos nos dois tratamentos, segundo delineamento inteiramente casualizado. Não foi verificada diferença para ganho de peso diário, ganho de peso total e peso final de abate. Com relação à carcaça, a área de olho-de-lombo, a espessura de gordura subcutânea e a espessura de gordura na garupa também não diferiram estatisticamente entre os tratamentos. Concluiu-se que a substituição integral do TMU pelo TSU não alterou o desempenho de bovinos jovens em confinamento.The differences on performance of young cattle fed diets with high moisture corn or sorghum were evaluated in two treatments, where the main energy source of the total diet was composed of high moisture corn (HMC or sorghum (HMS. Ninety Angus ´ Nelore crossbred young bulls, averaging 8 month of age and 240 kg BW and fed during 172 days were allotted to two experimental treatments as a completely randomized design. No treatment effect on average daily gain, total weight gain and slaughter final weight was observed. Regarding the carcass, ribeye area, subcutaneous fat thickness and rump fat thickness also did not differ between treatments. In conclusion, the totally replacement of high moisture corn by high moisture sorghum did not affect performance of feedlot young cattle.

  18. Desenvolvimento e estudos de estabilidade preliminares de emulsões O/A contendo Cetoconazol 2,0% = Development and Preliminary Stability Evaluations of O/W emulsion containing Ketoconazole 2.0%

    Directory of Open Access Journals (Sweden)

    Vanessa Catalá Casteli

    2008-07-01

    Full Text Available O objetivo deste trabalho foi desenvolver emulsões O/A contendo Cetoconazol 2,0% e avaliar sua estabilidade preliminar por meio da análise de suas características físicoquímicas, tais como homogeneidade, formação de agregados, floculação, cremeação ecoalescência. As emulsões foram formuladas utilizando diferentes bases autoemulsionantes, compostas por álcool cetoestearílico, álcool etoxilado, álcool graxos superiores, ácido esteárico, lanolina e outros. As emulsões foram submetidas aos testes de centrifugação,estresse térmico e ciclo gela-degela, e suas características organolépticas e físico-químicas foram avaliadas no início e no final de cada ensaio. Todas as amostras mantiveram sua homogeneidade após o teste de centrifugação, mas somente os sistemas preparados comceras autoemulsionáveis constituídas por álcool graxos superiores (Polawax NF® e Copolímero de Amônio Acriloil dimetiltaurato VP, Trilauril 4 fosfato, Sesquisosterato de metil glicose, Óleo de flores de verão e Tetradibutil pentaeritritil hidroxihidrocinamato deGlicerina (Hostacerin NCB® mantiveram sua estabilidade após testes de estresse térmico e ciclo gela-degela.The objective of this work was the development of O/W emulsions containing Ketoconazole 2.0% and to evaluate their preliminary stability by analyzing physical-chemical characteristics such as homogeneity, aggregation formation, flocculation, creaming and coalescence. The emulsions were formulated using different self-emulsifying bases, composed of cetearyl alcohol, ethoxylalcohol, higher fatty alcohol, stearic acid, lanolin and others. The O/W emulsions were evaluated by centrifugation test, thermal stress test, and freezing/defrosting cycles, and its organoleptic and physical-chemistry characteristics were analyzed before and after eachassay. All samples maintained their homogeneity after the centrifugation test, but only the systems prepared with self emulsifying composed of

  19. Desempenho da tilápia-do-Nilo arraçoada com dietas contendo farinha de sangue bovino atomizado ou convencional = Performance of nile tilapia fed with spray-dried or vat-dries bovine blood meal

    Directory of Open Access Journals (Sweden)

    Willian Vicente Narváez-Solarte

    2011-07-01

    Full Text Available Foi avaliado o desempenho e os índices de rendimento da tilápia-do-Nilo (Oreochromis niloticus alimentada com níveis crescentes de farinha de sangue atomizado (FSA ou de farinha de sangue convencional (FSC em dietas formuladas com base em aminoácidos digestíveis. Foram utilizados 252 alevinos, distribuídos num delineamento inteiramente casualizado, em esquema fatorial (2 x 4 + 1, duas classes de farinha de sangue com quatro níveis de inclusão de cada farinha na dieta, e uma dieta-controle, com quatro repetições. Os tratamentos consistiram em uma dieta-controle à base de farelo de soja, contendo 34% de proteína digestível (PD e 3.200 kcal de energia digestível kg-1 (ED, mais quatro rações formuladas com FSA e quatro rações com FSC, com inclusões de 5, 10, 15 e 20% de cada farinha na ração, mantendo-se os níveis de PD, ED, fósforo, cálcio, lisina, metionina, treonina e triptofano idênticos aos da dieta-controle. Concluiu-se que é possível utilizar até 15% da FSC em rações para tilápia-do-Nilo na fase de 5 a 150 g de peso vivo.The study evaluated the performance and carcass composition index of Nile tilapia (Oreochromis niloticus fed with diets containing increasing levels of spray-dried blood meal (SDBM and vat-dried blood meal (VDBM and formulated based on digestible amino acids. Two hundred and fifty-two fingerlings were distributed in a completelyrandomized design, in a (2 x 4 + 1 factorial model, two types of blood meal with four levels of each blood meal in the diet, and a control diet (without blood meal, with four replications. The treatments consisted of soybean meal-based control diet, with 34%digestible protein (DP and 3,200 kcal of digestible energy kg-1 (DE, plus four diets formulated with SDBM and four diets with VDBM, containing 5, 10, 15 and 20% of each meal in feed, maintaining identical DP, DE, phosphorus, calcium, lysine, methionine, threonine and tryptophan levels as those of the control diet. The

  20. Crescimento, conversão alimentar e rendimento de carcaça de bezerros da raça holandesa alimentados com dietas contendo diferentes níveis de volumoso

    Directory of Open Access Journals (Sweden)

    Ricardo Dias Signoretti

    1999-02-01

    Full Text Available Este trabalho foi conduzido para avaliar o efeito dos diferentes níveis de volumoso nas dietas sobre o consumo médio diário de matéria seca total (CDMST, o ganho médio de peso, a conversão alimentar e o rendimento de carcaça. Trinta e seis bezerros da raça Holandesa puros por cruzamento, com idade média de 60 dias e peso vivo (PV inicial de 78 kg, foram distribuídos em delineamento inteiramente casualizado. Os animais foram alimentados à vontade com dietas contendo níveis de 10, 25, 40 e 55% de volumoso, na base da MS, usando-se feno de capim coast-cross (Cynodon dactylon, fubá de milho e farelo de soja, os quais constituíram dietas com aproximadamente 16% de PB. Os animais foram pesados a cada periodo de 28 dias, com pesagens mais freqüentes para os animais que se aproximavam dos pesos de abate pré-estabelecidos, de 190 ± 10 kg e 300 ± 10 kg, para os grupos 1 e 2, respectivamente. O consumo de matéria seca não foi influenciado pelos níveis de volumoso nas dietas para ambos os grupos. Houve efeito linear crescente para conversão alimentar expressa em PV e peso corporal vazio (PCVZ. Os ganhos médios de peso diários expressos em PV e PCVZ decresceram linearmente, em função dos níveis de volumoso nas dietas. O peso da carcaça quente e o rendimento de carcaça quente para os animais de grupo 2 não foram influenciados, enquanto o rendimento de carcaça quente dos animais do grupo 1 decresceu linearmente, com o aumento de volumoso nas dietas. Os ganhos médios de pesos diários aos 28 e 56 dias, para o grupo 1, e aos 28, 56, 84 e 112 dias, para o grupo 2, reduziram linearmente com a elevação dos níveis de volumoso nas dietas. O desempenho dos bezerros de ambos os grupos de abate foi maior com uso de menores níveis de volumoso na dieta, porém, acima de 5 meses de idade, o uso de maiores níveis de volumoso não acarretou prejuízos à performance dos animais.

  1. In vitro antimicrobial efficiency of a mouthwash containing triclosan/gantrez and sodium bicarbonate Eficiência antimicrobiana in vitro de um enxaguatório bucal contendo triclosan/gantrez e bicarbonato de sódio

    Directory of Open Access Journals (Sweden)

    Juliana Rico Pires

    2007-12-01

    Full Text Available Several antiseptic substances have been used as adjuncts to routine mechanical procedures of oral hygiene, based on their antimicrobial effects. The objective of this study was to assess in vitro the antimicrobial efficiency of a mouthwash containing Triclosan/Gantrez and sodium bicarbonate in comparison to both positive and negative controls. Standard strain samples of Escherichia coli, Pseudomonas aeruginosa, Actinomyces viscosus and Bacillus subtilis were used. Samples of Streptococcus mutans and Gram-negative bacilli were collected from 20 volunteers (10 with a clinically healthy periodontium and 10 presenting biofilm-associated gingivitis. Evaluation of the antimicrobial activity was performed by determining the minimal inhibitory concentration (MIC. The results indicated that the test solution inhibited the growth of both Gram-negative and Gram-positive microorganisms from the volunteers’ saliva as well as that of the standard strains at the MIC dilution of 1:20, whereas the MIC dilution of 0.12% chlorhexidine against the same bacteria was 1:80. Thus, even though the tested mouthrinse solution presented an in-vitro antimicrobial activity superior to that of a placebo, it was inferior to that of chlorhexidine.Diversas substâncias antisépticas têm sido utilizadas como adjuntos aos procedimentos mecânicos rotineiros de higiene oral, com base em seus efeitos antimicrobianos. O objetivo deste estudo foi avaliar, in vitro, a eficiência antimicrobiana de um enxaguatório bucal contendo Triclosan/Gantrez e bicarbonato de sódio, em comparação a controles positivos e negativos. Linhagens padrão de Escherichia coli, Pseudomonas aeruginosa, Actinomyces viscosus e Bacillus subtilis foram utilizadas. Amostras de Streptococcus mutans e Bacilos Gram-negativos foram coletadas de 20 voluntários (10 com um periodonto clinicamente saudável e 10 com gengivite associada à presença de biofilme. A avaliação da atividade antimicrobiana foi

  2. A cytochemical study of acid carbohydrates on the surface of Candida lipolytica grown in tween 80-containing medium Estudo citoquímico dos carboidratos ácidos na superfície de Candida lipolytica crescida em meio contendo tween 80

    Directory of Open Access Journals (Sweden)

    Aline E. Nascimento

    2000-03-01

    Full Text Available Carbohydrate-containing molecules were located on the surface of Candida lipolytica by using ruthenium red in a cytochemical study. The yeast was grown in media containing Tween 80. The surfactant, at 1.0% and 0.5%, was added to the culture medium in different intervals of time, correspondent to the beginning of exponential growth phase, mid of logarithimic phase and beginning of stationary growth phase. Control cultures were grown in a medium containing glucose. The growth of the yeast in media containing glucose and Tween 80 induced changes in the pattern of distribution and location of acid polyssacharides in the cell wall of the microorganism. In adition, the pattern also changed according to Tween 80 concentration. The influence of Tween 80 on cellular carbohydrate expression is discussed.Moléculas contendo resíduos de açúcares foram localizadas sobre a superfície de Candida lipolytica utilizando-se o vermelho de rutênio como marcador citoquímico. A levedura foi semeada em meio contendo Tween 80. O surfactante, nas concentrações de 1,0% e 0,5%, foi adicionado ao meio de cultivo em diferentes intervalos de tempo, correspondentes ao início da fase exponencial de crescimento, meio da fase logarítmica e final da fase exponencial de crescimento, Culturas-controles foram cultivadas em meio contendo glicose como fonte de carbono. O crescimento da levedura em meios contendo glicose ou Tween 80 induziu o surgimento de alterações na distribuição e na localização de polissacarídeos ácidos na parede celular do organismo. Células crescidas em glicose ou Tween 80 exibiram variações citoquímicas em função de sua fase de crescimento. Adicionalmente, o padrão de marcação citoquímica também sofreu variações de acordo com a concentração do surfactante. A influência do surfactante na expressão de carboidratos é discutida.

  3. Comportamento de cura de adesivo epoxídico contendo grupo mercaptana avaliado por espectroscopia no infravermelho (MIR/NIR e calorimetria exploratória diferencial (DSC Cure behavior of epoxy adhesive containig mercaptan group evaluated by infrared spectroscopy (MIR/NIR and differential scanning calorimetry (DSC

    Directory of Open Access Journals (Sweden)

    Hilzette P. C. Andrade

    2008-01-01

    Full Text Available No presente trabalho, a flexibilidade de um adesivo epoxídico contendo diglicidiléter de bisfenol A (DGEBA e dietilenotriamina (DETA como agente de cura foi modificada pela adição de um segundo componente contendo grupos mercaptana (CAPCURE. A adição de amianto ao adesivo contendo CAPCURE também foi avaliada. As reações entre os grupos epoxídicos e os grupos amina, assim como entre os grupos epoxídicos e os grupos mercaptana, foram estudadas nas regiões espectrais do infravermelho médio (MIR e próximo (NIR. Observou-se que o amianto não interfere nas reações de cura e que a espectroscopia FT-NIR evidencia melhor as alterações espectrométricas ocorridas durante as reações em relação à análise FT-MIR. O tempo das reações de cura foi monitorado por calorimetria exploratória diferencial (DSC, observando-se que a introdução do CAPCURE acelerou a cura da resina. A energia de ativação (Ea das reações de cura foi obtida pelos métodos de Barrett e Borchardt-Daniels. Os adesivos contendo CAPCURE mostraram Ea em torno de 30 kJ.mol-1, enquanto o adesivo DGEBA/DETA apresentou Ea de 46 kJ.mol-1, ambas calculadas pelo método de Barrett.In the present work, the flexibility of an epoxy adhesive containing diglycidylether of bisphenol-A (DGEBA and diethylenetriamine (DETA as curing agent was changed by the addition of a second component containing mercaptan groups (CAPCURE. The addition of asbestos as a filler in the adhesive containing CAPCURE was also evaluated. Epoxy-amine and epoxy-mercaptan reactions were studied in NIR and MIR spectral regions. The filler addition did not cause influence on the cure reactions and spectrometric changes of cure reactions could be better observed by FT-NIR than FT-MIR analysis. The cure reaction time was monitored by DSC experiments and it was observed that the introduction of CAPCURE accelerated the cure reaction. The activation energies (Ea of curing reactions were obtained using Barrett

  4. Enhanced ion acoustic fluctuations and ion outflows

    Directory of Open Access Journals (Sweden)

    F. R. E. Forme

    1999-02-01

    Full Text Available A number of observations showing enhanced ion acoustic echoes observed by means of incoherent scatter radars have been reported in the literature. The received power is extremely enhanced by up to 1 or 2 orders of magnitude above usual values, and it is mostly contained in one of the two ion acoustic lines. This spectral asymmetry and the intensity of the received signal cannot be resolved by the standard analysis procedure and often causes its failure. As a result, and in spite of a very clear spectral signature, the analysis is unable to fit the plasma parameters inside the regions of ion acoustic turbulence. We present European Incoherent Scatter radar (EISCAT observations of large ion outflows associated with the simultaneous occurrence of enhanced ion acoustic echoes. The ion fluxes can reach 1014 m-2 s-1 at 800 km altitude. From the very clear spectral signatures of these echoes, a method is presented to extract estimates of the electron temperature and the ion drift within the turbulent regions. It is shown that the electron gas is strongly heated up to 11 000 K. Also electron temperature gradients of about 0.02 K/m exist. Finally, the estimates of the electron temperature and of the ion drift are used to study the possible implications for the plasma transport inside turbulent regions. It is shown that strong electron temperature gradients cause enhancement of the ambipolar electric field and can account for the observed ion outflows.Key words. Ionosphere (auroral ionosphere; ionosphere · magnetosphere interactions; plasma waves and instabilities.

  5. Vacuum Arc Ion Sources

    CERN Document Server

    Brown, I.

    2013-12-16

    The vacuum arc ion source has evolved into a more or less standard laboratory tool for the production of high-current beams of metal ions, and is now used in a number of different embodiments at many laboratories around the world. Applications include primarily ion implantation for material surface modification research, and good performance has been obtained for the injection of high-current beams of heavy-metal ions, in particular uranium, into particle accelerators. As the use of the source has grown, so also have the operational characteristics been improved in a variety of different ways. Here we review the principles, design, and performance of vacuum arc ion sources.

  6. Heavy-ion radiography

    International Nuclear Information System (INIS)

    Fabrikant, J.I.; Tobias, C.A.; Holley, W.R.; Benton, E.V.; Woodruff, K.H.; MacFarland, E.W.

    1983-01-01

    High energy, heavy-ion beams offer superior discrimination of tissue electron densities at very low radiation doses. This characteristic has potential for diagnostic medical imaging of neoplasms arising in the soft tissues and organs because it can detect smaller inhomogeneities than x rays. Heavy-ion imaging may also increase the accuracy of cancer radiotherapy planning involving use of accelerated charged particles. In the current physics research program of passive heavy-ion imaging, critical modulation transfer function tests are being carried out in heavy-ion projection radiography and heavy-ion computerized tomography. The research goal is to improve the heavy-ion imaging method until it reaches the limits of its theoretical resolution defined by range straggling, multiple scattering, and other factors involved in the beam quality characteristics. Clinical uses of the imaging method include the application of heavy-ion computerized tomography to heavy-ion radiotherapy planning, to the study of brain tumors and other structures of the head, and to low-dose heavy-ion projection mammography, particularly for women with dense breasts where other methods of diagnosis fail. The ions used are primarily 300 to 570 MeV/amu carbon and neon ions accelerated at the Lawrence Berkeley Laboratory Bevalac

  7. Ion implantation into iron

    International Nuclear Information System (INIS)

    Iwaki, Masaya

    1978-01-01

    The distribution of implanted ions in iron, the friction characteristics and the corrosion of iron were studied. The distribution of Ni or Cr ions implanted into mild steel was measured. The accelerated voltage was 150 keV, and the beam current density was about 2 microampere/cm 2 . The measurement was made with an ion microanalyzer. The measured distribution was compared with that of LSS theory. Deep invasion of Ni was seen in the measured distribution. The distribution of Cr ions was different from the distribution calculated by the LSS theory. The relative friction coefficient of mild steel varied according to the dose of implanted Cu or N ions, and to the accelerating voltage. Formation of compound metals on the surfaces of metals by ion-implantation was investigated for the purpose to prevent the corrosion of metals. The resistance of mild steel in which Ni ions were implanted was larger than that of mild steel without any treatment. (Kato, T.)

  8. Crater formation by single ions, cluster ions and ion "showers"

    CERN Document Server

    Djurabekova, Flyura; Timko, Helga; Nordlund, Kai; Calatroni, Sergio; Taborelli, Mauro; Wuensch, Walter

    2011-01-01

    The various craters formed by giant objects, macroscopic collisions and nanoscale impacts exhibit an intriguing resemblance in shapes. At the same time, the arc plasma built up in the presence of sufficiently high electric fields at close look causes very similar damage on the surfaces. Although the plasma–wall interaction is far from a single heavy ion impact over dense metal surfaces or the one of a cluster ion, the craters seen on metal surfaces after a plasma discharge make it possible to link this event to the known mechanisms of the crater formations. During the plasma discharge in a high electric field the surface is subject to high fluxes (~1025 cm-2s-1) of ions with roughly equal energies typically of the order of a few keV. To simulate such a process it is possible to use a cloud of ions of the same energy. In the present work we follow the effect of such a flux of ions impinging the surface in the ‘‘shower’’ manner, to find the transition between the different mechanisms of crater formati...

  9. Dietas contendo silagem de milho (Zea maiz L. e feno de capim-tifton 85 (Cynodon spp. em diferentes proporções para bovinos Corn silage and tifton 85 bermudagrass hay-based diets for steers

    Directory of Open Access Journals (Sweden)

    Ana Clara Rodrigues Cavalcante

    2004-12-01

    Full Text Available Avaliaram-se o consumo, a digestibilidade, o pH e concentração de amônia ruminais e a taxa de passagem em bovinos alimentados com dietas contendo feno de capim-tifton 85 (TIF e silagem de milho (SM em diferentes proporções. Utilizaram-se quatro animais castrados, com peso médio de 523kg, fistulados no rúmen, distribuídos em um quadrado latino 4 x 4, recebendo 60% de volumoso e 40% de concentrado, na base da matéria seca. O volumoso consistiu das seguintes proporções (%: 100 TIF:0 SM; 67 TIF:33 SM; 33 TIF:67 SM e 0 TIF:100 SM. Os consumos de matéria seca (MS, de matéria orgânica (MO e de matéria orgânica digestível (MOD, de proteína bruta (PB, de fibra em detergente neutro (FDN e de carboidratos totais (CHOT e digeríveis (CHOD não foram influenciados pelas diferentes proporções de feno de capim-tifton 85: silagem de milho nas dietas, registrando-se valores médios de 9,2; 8,7; 6,4; 1,1; 3,7; 7,3 e 5,4 kg/dia, respectivamente. O consumo de extrato etéreo (EE elevou linearmente com o aumento da silagem de milho nas dietas. As digestibilidades aparentes da MS, MO, PB, EE e CHO também não foram influenciadas pelas diferentes proporções de silagem de milho, obtendo-se, respectivamente, valores médios de 71,8; 73,0; 69,5; 69,2 e 73,9%. Para a digestibilidade da FDN, observou-se efeito quadrático, estimando-se valor máximo de 65,2% para dietas contendo 30,98% de silagem de milho. Estimou-se concentração máxima de amônia de 12,0 mg/100 ml e valor mínimo de pH de 5,98 às 2,44 e 6,82 horas após a alimentação, respectivamente. A taxa de passagem não foi influenciada pelas diferentes proporções de feno:silagem, no volumoso, apresentando valor médio de 4,2%/hora.The intake, digestibility, ruminal pH and ammonia concentrations and passage rate were evaluated in steers fed corn silage (CS and Tifton 85 bermudagrass hay (T85H-based diets, at different forage proportions. Four rumen fistulated steers with 523 kg of live

  10. Fermentação ruminal e eficiência microbiana em bezerros holandeses alimentados com dietas contendo diferentes níveis de concentrado Ruminal fermentation and microbial efficiency in Holstein calves fed diets with different concentrate levels

    Directory of Open Access Journals (Sweden)

    Peter Johann Bürger

    2000-02-01

    Full Text Available RESUMO - Este trabalho foi realizado para avaliar os efeitos de diferentes níveis de concentrado sobre os parâmetros da fermentação ruminal, as digestibilidades aparente, total, ruminal e intestinal de N, a eficiência microbiana e o balanço de N. Cinco bezerros holandeses, inteiros, fistulados no rúmen e abomaso, com idade média inicial de 5,8±0,7 meses e 107,4±11,0 kg PV médio inicial, foram distribuídos em quadrado latino 5x5 (tratamento x período. Os animais foram alojados em baias individuais e alimentados à vontade com dietas contendo 30,0; 45,0; 60;0; 75,0; e 90,0% de concentrado, com base na MS, em rações contendo como volumoso, o feno de capim coast-cross e no concentrado, o farelo de soja, fubá de milho. Os valores de pH foram influenciados pelos níveis de concentrado das rações, e , 11,3 horas após a alimentação, foram estimandos os valores mínimos de 6,10; 5,89; 5,67; 5,46; e 5,24, para as rações com níveis de 30,0; 45,0; 60,0; 75,0; e 90,0%de concentrado nas rações, respectivamente. A concentração de amônia ruminal reduziu linearmente, em função dos tempos pós-alimentação, apresentando comportamento quadrático, com valores mínimos de 6,84; 7,14; 7,63; 7,82; 8,09; e 8,00 mg/dL, para 86,31; 84,86; 83,41; 81,95; 77,59; e 68,86% de concentrado nas rações. O numero de protozoários ruminais reduziu linearmente com o aumento dos níveis de concentrado nas rações. A eficiência de síntese de compostos nitrogenados microbianos aumentou linearmente com os níveis de concentrado nas rações.ABSTRACT - This work was conducted to evaluate the effects of different concentrate levels on the parameters of at ruminal fermentation, the apparent, total, ruminal and intestinal N digestibilities, the microbial efficiency and the N balance. Five rumen and abomasum fistulated bull Holstein calves, with an initial average age of 5.8±0.7 months and initial average of 107.4±11.0 kg LW were allotted to a 5x5

  11. Optical effects of ion implantation

    International Nuclear Information System (INIS)

    Townsend, P.D.

    1987-01-01

    The review concerns the effects of ion implantation that specifically relate to the optical properties of insulators. Topics which are reviewed include: ion implantation, ion range and damage distributions, colour centre production by ion implantation, high dose ion implantation, and applications for integrated optics. Numerous examples are presented of both diagnostic and industrial examples of ion implantation effects in insulators. (U.K.)

  12. Ion beam stabilization in ion implantation equipment

    International Nuclear Information System (INIS)

    Pina, L.

    1973-01-01

    The results are presented of experimental efforts aimed at ion beam current stabilization in an equipment for ion implantation in solids. The related problems of power supplies are discussed. Measured characteristics of laboratory equipment served the determination of the parameters to be required of the supplies as well as the design and the construction of the supplies. The respective wiring diagram is presented. (J.K.)

  13. Calculation of ion storage in electron beams with account of ion-ion interactions

    International Nuclear Information System (INIS)

    Perel'shtejn, Eh.A.; Shirkov, G.D.

    1979-01-01

    Ion storage in relativistic electron beams was calculated taking account of ion-ion charge exchange and ionization. The calculations were made for nitrogen ion storage from residual gas during the compression of electron rings in the adhezator of the JINR heavy ion accelerator. The calculations were made for rings of various parameters and for various pressures of the residual gas. The results are compared with analogous calculations made without account of ion-ion processes. It is shown that at heavy loading of a ring by ions ion-ion collisions play a significant part, and they should be taken into account while calculating ion storage

  14. Duopigatron ion source studies

    International Nuclear Information System (INIS)

    Bacon, F.M.; Bickes, R.W. Jr.; O'Hagan, J.B.

    1978-07-01

    Ion source performance characteristics consisting of total ion current, ion energy distribution, mass distribution, and ion current density distribution were measured for several models of a duopigatron. Variations on the duopigatron design involved plasma expansion cup material and dimensions, secondary cathode material, and interelectrode spacings. Of the designs tested, the one with a copper and molybdenum secondary cathode and a mild steel plasma expansion cup proved to give the best results. The ion current density distribution was peaked at the center of the plasma expansion cup and fell off to 80 percent of the peak value at the cup wall for a cup 15.2 mm deep. A total ion current of 180 mA consisting of 60 to 70 percent atomic ions was produced with an arc current of 20 A and source pressure of 9.3 Pa. More shallow cups produced a larger beam current and a more sharply peaked ion current density distribution. Typical ion energy distributions were bell-shaped curves with a peak 10 to 20 V below anode potential and with ion energies extending 30 to 40 V on either side of the peak

  15. Quantitative ion implantation

    International Nuclear Information System (INIS)

    Gries, W.H.

    1976-06-01

    This is a report of the study of the implantation of heavy ions at medium keV-energies into electrically conducting mono-elemental solids, at ion doses too small to cause significant loss of the implanted ions by resputtering. The study has been undertaken to investigate the possibility of accurate portioning of matter in submicrogram quantities, with some specific applications in mind. The problem is extensively investigated both on a theoretical level and in practice. A mathematical model is developed for calculating the loss of implanted ions by resputtering as a function of the implanted ion dose and the sputtering yield. Numerical data are produced therefrom which permit a good order-of-magnitude estimate of the loss for any ion/solid combination in which the ions are heavier than the solid atoms, and for any ion energy from 10 to 300 keV. The implanted ion dose is measured by integration of the ion beam current, and equipment and techniques are described which make possible the accurate integration of an ion current in an electromagnetic isotope separator. The methods are applied to two sample cases, one being a stable isotope, the other a radioisotope. In both cases independent methods are used to show that the implantation is indeed quantitative, as predicted. At the same time the sample cases are used to demonstrate two possible applications for quantitative ion implantation, viz. firstly for the manufacture of calibration standards for instrumental micromethods of elemental trace analysis in metals, and secondly for the determination of the half-lives of long-lived radioisotopes by a specific activity method. It is concluded that the present study has advanced quantitative ion implantation to the state where it can be successfully applied to the solution of problems in other fields

  16. Heating tokamaks via the ion-cyclotron and ion-ion hybrid resonances

    International Nuclear Information System (INIS)

    Perkins, F.W.

    1977-04-01

    For the ion-ion hybrid resonance it is shown that: (1) the energy absorption occurs via a sequence of mode conversions; (2) a poloidal field component normal to the ion-ion hybrid mode conversion surface strongly influences the mode conversion process so that roughly equal electron and ion heating occurs in the present proton-deuterium experiments, while solely electron heating is predicted to prevail in deuterium-tritium reactors; (3) the ion-ion hybrid resonance suppresses toroidal eigenmodes; and (4) wave absorption in minority fundamental ion-cyclotron heating experiments will be dominated by ion-ion hybrid mode conversion absorption for minority concentrations exceeding roughly 1 percent. For the ion-cyclotron resonance, it is shown that: (1) ion-cyclotron mode conversion leads to surface electron heating; and (2) ion-cyclotron mode conversion absorption dominates fundamental ion-cyclotron absorption thereby preventing efficient ion heating

  17. Morphological and structural analysis of ferrite NiFe{sub 2}O{sub 4} doped with chromium; Analise estrutural e morfologica de ferrita NiFe{sub 2}O{sub 4} dopada com cromo

    Energy Technology Data Exchange (ETDEWEB)

    Costa, A.C.F., E-mail: anacristina@dema.ufcg.edu.br [Universidade Federal de Campina Grande (UFCG), PB (Brazil). Unidade Academica de Engenharia de Materiais; Viana, K.M.S. [Universidade Federal do Rio Grande do Norte (UFRN), Natal (Brazil). Escola de Ciencias e Tecnologia; Miola, E.J.; Antonio, S.G.; Kiminami, R.H.G.A. [Universidade Federal de Sao Carlos (UFSCar), SP (Brazil); Paiva-Santos, C.O. [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Araraquara, SP (Brazil). Departamento de Fisico-Quimica

    2011-07-01

    This paper reports on the effect of the substitution of Fe{sup 3+} for Cr{sup 3+} ions in the spinel lattice of the powders was investigated. Nickel ferrite powders with a NiFe{sub 2-x}Cr{sub x}O{sub 4} nominal composition (x = 0.0; 0.5; 1.0 and 1.5 mol of the chromium) were synthesized by combustion reaction using urea as fuel. The powders resulting were characterized by XRD, nitrogen adsorption by BET, SEM and Mössbauer spectroscopy ({sup 57}Fe Mössbauer spectra). The results show that the substitution of the Fe{sup 3+} for Cr{sup 3+} ions increased the crystalline degree of the phase, reduced the superficial area and consequently increased the particle size. The Mössbauer spectra of the samples also confirm the distribution of the particles size by the magnetic properties. Analyze of the spectra Mössbauer gives an estimate of the superparamagnetic and ferromagnetic particles behavior in each sample for several chromium concentrations. (author)

  18. Atmospheric ions and pollution

    International Nuclear Information System (INIS)

    Renoux, A.

    1977-01-01

    The various types of atmospheric ions are defined, the main sources of natural atmospheric radioactivity inducing the formation of radioactive ions in the air are then recalled. The basic equations governing the formation of these ions are indicated and the most current experimental methods used for detecting them are described (Zeleny tubes, Erikson tubes). The special properties of these ions are examined, they are particularly emphasized for the smaller ones. The existence of a discret spectrum of mobilities is shown and the presence of big negative radioactive ions is investigated. Indicative information are given on the granulometric distribution of the atmospheric radioactivity in the air, from small positive Ra A ion fixation on aerosols [fr

  19. Materials analysis fast ions

    CERN Document Server

    Denker, A; Rauschenberg, J; Röhrich, J; Strub, E

    2006-01-01

    Materials analysis with ion beams exploits the interaction of ions with the electrons and nuclei in the sample. Among the vast variety of possible analytical techniques available with ion beams we will restrain to ion beam analysis with ion beams in the energy range from one to several MeV per mass unit. It is possible to use either the back-scattered projectiles (RBS – Rutherford Back Scattering) or the recoiled atoms itself (ERDA – Elastic Recoil Detection Analysis) from the elastic scattering processes. These techniques allow the simultaneous and absolute determination of stoichiometry and depth profiles of the detected elements. The interaction of the ions with the electrons in the sample produces holes in the inner electronic shells of the sample atoms, which recombine and emit X-rays characteristic for the element in question. Particle Induced X-ray Emission (PIXE) has shown to be a fast technique for the analysis of elements with an atomic number above 11.

  20. Ion thruster performance model

    International Nuclear Information System (INIS)

    Brophy, J.R.

    1984-01-01

    A model of ion thruster performance is developed for high flux density cusped magnetic field thruster designs. This model is formulated in terms of the average energy required to produce an ion in the discharge chamber plasma and the fraction of these ions that are extracted to form the beam. The direct loss of high energy (primary) electrons from the plasma to the anode is shown to have a major effect on thruster performance. The model provides simple algebraic equations enabling one to calculate the beam ion energy cost, the average discharge chamber plasma ion energy cost, the primary electron density, the primary-to-Maxwellian electron density ratio and the Maxwellian electron temperature. Experiments indicate that the model correctly predicts the variation in plasma ion energy cost for changes in propellant gas (Ar, Kr, and Xe), grid transparency to neutral atoms, beam extraction area, discharge voltage, and discharge chamber wall temperature

  1. Ion emission microscope microanalyzer

    International Nuclear Information System (INIS)

    Cherepin, V.T.; Olckovsky, V.L.

    1977-01-01

    In the ion microanalyzer (microprobe) the object is exposed to the bombardment of a highly focused ion beam, the secondary ions emitted from the object being analyzed by means of a mass filter. In order to be able to control the position of an analysis synchronous to the local analysis of an object an ion-optical converter (electron image with a fluorescent screen) is placed behind the aperture diaphragm in the direction of the secondary ion beam. The converter allows to make visible in front of the mass filter a non-split ion image characterizing the surface of the surface investigated. Then a certain section may be selected for performing chemical and isotope analyses. (DG) [de

  2. Outlook for ion exchange

    International Nuclear Information System (INIS)

    Kunin, R.

    1977-01-01

    This paper presents the history and theory of ion exchange technology and discusses the usefulness of ion exchange resins which found broad applications in chemical operations. It is demonstrated that the theory of ion exchange technology seems to be moving away from the physical chemist back to the polymer chemist where it started originally. This but confronted the polymer chemists with some knotty problems. It is pointed out that one has still to learn how to use ion exchange materials as efficiently as possible in terms of the waste load that is being pumped into the environment. It is interesting to note that, whereas ion exchange is used for abating pollution, it is also a polluter. One must learn how to use ion exchange as an antipollution device, and at the same time minimize its polluting properties

  3. HEAVY ION LINEAR ACCELERATOR

    Science.gov (United States)

    Van Atta, C.M.; Beringer, R.; Smith, L.

    1959-01-01

    A linear accelerator of heavy ions is described. The basic contributions of the invention consist of a method and apparatus for obtaining high energy particles of an element with an increased charge-to-mass ratio. The method comprises the steps of ionizing the atoms of an element, accelerating the resultant ions to an energy substantially equal to one Mev per nucleon, stripping orbital electrons from the accelerated ions by passing the ions through a curtain of elemental vapor disposed transversely of the path of the ions to provide a second charge-to-mass ratio, and finally accelerating the resultant stripped ions to a final energy of at least ten Mev per nucleon.

  4. Comportamento ingestivo de cordeiros e digestibilidade dos nutrientes de dietas contendo alta proporção de concentrado e diferentes fontes de fibra em detergente neutro Lamb feeding behavior and nutrient digestibility of high concentrate diets with different neutral detergent fiber sources

    Directory of Open Access Journals (Sweden)

    Clayton Quirino Mendes

    2010-03-01

    Full Text Available Dois experimentos foram realizados para avaliar os efeitos da substituição da fibra em detergente neutro (FDN do bagaço de cana-de-açúcar in natura pela FDN da casca de soja em dietas com alta proporção de concentrado sobre o comportamento ingestivo de cordeiros e a digestibilidade dos nutrientes. No primeiro experimento, 60 cordeiros com 16,4 ± 0,3 kg de peso corporal e idade inicial de 67 ± 2 dias foram distribuídos em delineamento de blocos completos casualizados, em esquema fatorial 2 × 2 + 1, composto de duas fontes de FDN (bagaço de cana in natura ou casca de soja, dois teores de FDN (14 ou 18% e uma dieta controle contendo 100% de concentrado. No segundo experimento, cinco cordeiros foram distribuídos em quadrado latino 5 × 5 e submetidos às mesmas dietas do experimento 1. As dietas contendo as fontes de fibra promoveram maior consumo de matéria seca, matéria orgânica e FDN e maior tempo de ingestão, ruminação e mastigação (minutos/dia em comparação à dieta contendo 100% de concentrado. As dietas contendo o bagaço de canade-açúcar in natura proporcionaram maior atividade de ruminação que aquelas com casca de soja. Entretanto, a utilização da casca de soja proporcionou menor atividade de mastigação e maior digestibilidade dos nutrientes em relação ao bagaço de cana-de-açúcar in natura. A casca de soja pode ser utilizada como única fonte adicional de FDN em dietas contendo alto teor de concentrado para cordeiros.Two experiments were performed to determine the effects of replacing the neutral detergent fiber from sugarcane bagasse with soybean hulls neutral detergent fiber in high concentrate diets on lamb feeding behavior and apparent nutrient digestibility. In the first experiment, 60 ram lambs with 16.4 ± 0.3 kg body weight and 67 ± 2 days old were allotted to a complete randomized block design as a 2 × 2 + 1 factorial arrangement of treatments, consisting of two neutral detergent fiber sources

  5. Electron-ion collisions

    International Nuclear Information System (INIS)

    Crandall, D.H.

    1982-01-01

    This discussion concentrates on basic physics aspects of inelastic processes of excitation, ionization, and recombination that occur during electron-ion collisions. Except for cases of illustration along isoelectronic sequences, only multicharged (at least +2) ions will be specifically discussed with some emphasis of unique physics aspects associated with ionic charge. The material presented will be discussed from a primarily experimental viewpoint with most attention to electron-ion interacting beams experiments

  6. Ion implantation in semiconductors

    International Nuclear Information System (INIS)

    Gusev, V.; Gusevova, M.

    1980-01-01

    The historical development is described of the method of ion implantation, the physical research of the method, its technological solution and practical uses. The method is universally applicable, allows the implantation of arbitrary atoms to an arbitrary material, ensures high purity of the doping element. It is linked with sample processing at low temperatures. In implantation it is possible to independently change the dose and energy of the ions thereby affecting the spatial distribution of the ions. (M.S.)

  7. Ion implantation in semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Gusev, V; Gusevova, M

    1980-06-01

    The historical development of the method of ion implantation, the physical research of the method, its technological solution and practical uses is described. The method is universally applicable, allows the implantation of arbitrary atoms to an arbitrary material and ensures high purity of the doping element. It is linked with sample processing at low temperatures. In implantation it is possible to independently change the dose and energy of the ions thereby affecting the spatial distribution of the ions.

  8. Ion implantation in metals

    International Nuclear Information System (INIS)

    Vook, F.L.

    1977-02-01

    The application of ion beams to metals is rapidly emerging as a promising area of research and technology. This report briefly describes some of the recent advances in the modification and study of the basic properties of metals by ion implantation techniques. Most of the research discussed illustrates some of the new and exciting applications of ion beams to metals which are under active investigation at Sandia Laboratories, Albuquerque

  9. Heavy-ion targets

    International Nuclear Information System (INIS)

    Adair, H.L.; Kobisk, E.H.

    1985-01-01

    This chapter examines the characteristics of targets required in heavy-ion accelerator physics experiments. The effects of target parameters on heavy-ion experimental results are reviewed. The target fabrication and characterization techniques used to minimize experimental problems during heavy-ion bombardment are described. Topics considered include target thickness and uniformity, target lifetime, target purity, substrate materials, Doppler shift effects, metal preparations, and target preparation methods

  10. Cluster ion beam facilities

    International Nuclear Information System (INIS)

    Popok, V.N.; Prasalovich, S.V.; Odzhaev, V.B.; Campbell, E.E.B.

    2001-01-01

    A brief state-of-the-art review in the field of cluster-surface interactions is presented. Ionised cluster beams could become a powerful and versatile tool for the modification and processing of surfaces as an alternative to ion implantation and ion assisted deposition. The main effects of cluster-surface collisions and possible applications of cluster ion beams are discussed. The outlooks of the Cluster Implantation and Deposition Apparatus (CIDA) being developed in Guteborg University are shown

  11. Neutron ion temperature measurement

    International Nuclear Information System (INIS)

    Strachan, J.D.; Hendel, H.W.; Lovberg, J.; Nieschmidt, E.B.

    1986-11-01

    One important use of fusion product diagnostics is in the determination of the deuterium ion temperature from the magnitude of the 2.5 MeV d(d,n) 3 He neutron emission. The detectors, calibration methods, and limitations of this technique are reviewed here with emphasis on procedures used at PPPL. In most tokamaks, the ion temperature deduced from neutrons is in reasonable agreement with the ion temperature deduced by other techniques

  12. Ion transport in stellarators

    International Nuclear Information System (INIS)

    Ho, D.D.M.; Kulsrud, R.M.

    1985-09-01

    Stellarator ion transport in the low-collisionality regime with a radial electric field is calculated by a systematic expansion of the drift-Boltzmann equation. The shape of the helical well is taken into account in this calculation. It is found that the barely trapped ions with three to four times the thermal energy give the dominant contribution to the diffusion. Expressions for the ion particle and energy fluxes are derived

  13. Ion optics in an ion source system

    Energy Technology Data Exchange (ETDEWEB)

    Abdel-Salam, F W; Moustafa, O A; El-Khabeary, H [Accelerators Dept, Nuclear Research Center, Atomic Energy Authority, Cairo (Egypt)

    1997-12-31

    An analysis of ion beams from an ion source which consisted of a hemispherical anode, a plane earthed cathode, and a focusing electrode has been carried out. The focal properties of such electrode arrangement were studied using axially symmetric fields. Axial and radial electric fields were obtained as functions of the axial distance. It was found that the radial component of the gradient of potential pushes the ions towards the axis, which indicates the convergent action of the system. The effect of voltage variation between the boundary and the focusing electrode on the position of the plasma boundary are given using the experimental data of the ion source characteristics and its geometrical parameters. The advantages of plasma diffusing outside the source through a small aperture were used by applying a potential to the focusing electrode. It was possible to extract a large ion current from the expanded plasma. The system constituted a lens with a focal length of 29.4 mm. 7 figs.

  14. Ion trap device

    Science.gov (United States)

    Ibrahim, Yehia M.; Smith, Richard D.

    2016-01-26

    An ion trap device is disclosed. The device includes a series of electrodes that define an ion flow path. A radio frequency (RF) field is applied to the series of electrodes such that each electrode is phase shifted approximately 180 degrees from an adjacent electrode. A DC voltage is superimposed with the RF field to create a DC gradient to drive ions in the direction of the gradient. A second RF field or DC voltage is applied to selectively trap and release the ions from the device. Further, the device may be gridless and utilized at high pressure.

  15. Doppler ion program description

    International Nuclear Information System (INIS)

    Henline, P.

    1980-12-01

    The Doppler spectrometer is a conventional Czerny-Turner grating spectrometer with a 1024 channel multiple detector. Light is dispersed across the detector, and its output yields a spectrum covering approximately 200 A. The width of the spectral peak is directly proportional to the temperature of the emitting ions, and determination of the impurity ion temperature allows one to infer the plasma ion temperature. The Doppler ion software system developed at General Atomic uses a TRACOR Northern 1710-31 and an LSI-11/2. The exact configuration of Doublet III is different from TRACOR Northern systems at other facilities

  16. Lithium-ion batteries

    CERN Document Server

    Yoshio, Masaki; Kozawa, Akiya

    2010-01-01

    This book is a compilation of up-to-date information relative to Li-Ion technology. It provides the reader with a single source covering all important aspects of Li-Ion battery operations. It fills the gap between the old original Li-Ion technology and present state of the technology that has developed into a high state of practice. The book is designed to provide a single source for an up-to-date description of the technology associated with the Li-Ion battery industry. It will be useful to researchers interested in energy conversion for the direct conversion of chemical energy into electrica

  17. Correlation ion mobility spectroscopy

    Science.gov (United States)

    Pfeifer, Kent B [Los Lunas, NM; Rohde, Steven B [Corrales, NM

    2008-08-26

    Correlation ion mobility spectrometry (CIMS) uses gating modulation and correlation signal processing to improve IMS instrument performance. Closely spaced ion peaks can be resolved by adding discriminating codes to the gate and matched filtering for the received ion current signal, thereby improving sensitivity and resolution of an ion mobility spectrometer. CIMS can be used to improve the signal-to-noise ratio even for transient chemical samples. CIMS is especially advantageous for small geometry IMS drift tubes that can otherwise have poor resolution due to their small size.

  18. Heavy ion storage rings

    International Nuclear Information System (INIS)

    Schuch, R.

    1987-01-01

    A brief overview of synchrotron storage rings for heavy ions, which are presently under construction in different accelerator laboratories is given. Ions ranging from protons up to uranium ions at MeV/nucleon energies will be injected into these rings using multiturn injection from the accelerators available or being built in these laboratories. After injection, it is planned to cool the phase space distribution of the ions by merging them with cold electron beams or laser beams, or by using stochastic cooling. Some atomic physics experiments planned for these rings are presented. 35 refs

  19. Desempenho bioeconômico de suínos em crescimento e terminação alimentados com rações contendo farelo de coco Bioeconomic performance of growing - finishing pigs fed diet with coconut meal

    Directory of Open Access Journals (Sweden)

    José Evânio da Costa Siebra

    2008-11-01

    Full Text Available Objetivou-se avaliar o desempenho de suínos em crescimento e terminação alimentados com rações contendo farelo de coco. Foram utilizados 20 suínos machos castrados mestiços Landrace × Large White com 19,7 ± 2,9 kg de peso vivo inicial e 89,2 ± 5,8 kg de peso vivo final distribuídos em delineamento de blocos casualizados com quatro tratamentos (0, 10, 20 ou 30% de farelo de coco e cinco repetições. Avaliaram-se o desempenho, o ganho de peso médio diário, o consumo de ração médio diário e a conversão alimentar nas fases de crescimento (65 a 107 dias de idade e crescimento-terminação (65 a 149 dias de idade. Os parâmetros econômicos avaliados foram a receita bruta média, o custo médio da alimentação, a margem bruta média e a rentabilidade média. Os melhores resultados de ganho de peso médio diário e receita bruta média na fase de crescimento foram obtidos com o nível de 22,5% de farelo de coco na ração. Na fase de crescimento-terminação, a receita bruta média no período total indica que é possível incluir 22,4% de farelo de coco em dietas para suínos formuladas com farelo residual de milho e farelo de soja.The objective was to evaluate the performance of growing- finishing pigs fed diet with coconut meal. Twenty crossbred Large White × Landrace barrows with initial 19.7 ± 2.9 kg BW and final 89.2 ± 5.8 kg BW were allotted to complete a randomized blocks design with four levels (0, 10, 20 or 30% of coconut meal and five replications. Performance traits, as average daily weight gain, average daily feed intake and feed conversion ratio in grower phase (65 to 107 days old and grower-finisher phase (65 to 149 days old were evaluated. Economic parameters evaluated were: average gross income, average feed cost, gross margin and average return. The best results of average weight daily gain and average gross income in the grower phase were obtained with the level of 22.5% of coconut meal in the diet. In grower

  20. Estudo de perfil de dissolução dos medicamentos de referência, genérico e similar contendo cefalexina na forma farmacêutica cápsula

    Directory of Open Access Journals (Sweden)

    MARLUS CHORILLI

    2010-06-01

    Full Text Available Com o avanço da tecnologia e das pesquisas envolvendo liberação de fármacos, modernização de testes e maior ênfase da previsibilidade de efeitos terapêuticos por meio dos testes in vitro, os testes de dissolução e os estudos de perfis de dissolução têm ganhado cada vez mais importância. Apesar de terem sido introduzidos inicialmente como uma forma de caracterizar o perfil de liberação de fármacos pouco solúveis, atualmente os testes de dissolução fazem parte das monografias de quase todas as formas farmacêuticas sólidas orais. Este trabalho teve como objetivo estudar o perfil de dissolução (porcentagem de fármaco dissolvido versus tempo dos medicamentos de referência, genérico e similar contendo cefalexina 500 mg na forma farmacêutica de cápsulas. Foram analisadas três especialidades farmacêuticas (referência, genérico e similar, os quais foram submetidos ao teste de dissolução e perfil de dissolução in vitro. Os resultados obtidos no teste de dissolução permitem concluir que as amostras encontraram-se de acordo com as especificações e o perfil de dissolução deste medicamento, nesta forma farmacêutica, é considerado de dissolução rápida (85% de fármaco dissolvido em 15 minutos. Portanto, existe uma grande semelhança entre as curvas obtidas, o que sugere que se trata de equivalentes farmacêuticos. Palavras-chave: Cefalexina. Perfil de dissolução. Medicamento referência. Medicamento genérico. Medicamento similar. ABSTRACT Study of dissolution profile of the pioneer brand name, generic and similar brand name pharmaceutical products containing cephalexin in the form of capsules With recent advances in technology and research into drug delivery, the modernization of tests and greater emphasis on the predictability of therapeutic effect by means of in vitro tests, the dissolution test and the study of dissolution profiles are gaining more and more importance. Though introduced

  1. Superovulação em coelhas alimentadas com ração, contendo diferentes fontes de óleos vegetais = Super-ovulation in rabbit does fed on rations containing different sources of vegetable oil

    Directory of Open Access Journals (Sweden)

    Márcia Aparecida Andreazzi

    2006-07-01

    Full Text Available Avaliou-se a resposta ovulatória de 40 coelhas, distribuídas em um delineamento experimental inteiramente casualizado, com quatro tratamentos (ração sem adição de óleo e rações contendo 3% de óleo de canola, óleo de milho ou óleo de soja e 10 repetições. Aplicou-se uma dose única de 40 UI de gonadotrofina coriônica eqüina (eCG e, 48 horas após, as coelhas foram cobertas. Decorridas 72 horas das coberturas, as coelhas foram sacrificadas e coletaram-se 10 mL de sangue para análise dos níveis séricos de progesterona e 17β-estradiol. Também foi obtido o peso do útero com os ovários e contado o número de folículos e de corpos lúteos. Para a colheita dos embriões, realizaram-se 3 lavagens por corno uterino, com o meio Dulbecco modificado (PBS. O efluente foi colhido e as estruturasembrionárias avaliadas. Não foram observadas diferenças (P>0,05 quanto aos níveis séricos de progesterona e 17β-estradiol, peso do útero com os ovários, número de folículos e de corpos lúteos nos ovários direito e esquerdo e n��mero de estruturas viáveis e degeneradas. Porém, houve efeito (PEffects of super-ovulation on 40 rabbit does were evaluated. Females were distributed in a completely randomized design, with four treatments (oil-free ration and rations with 3% canola oil, corn oil or soybean oil and 10 replications. Each doe received a unique intramuscular dose of 40 UI of equine corionic gonadotrophin (eCG; 48hours later they underwent breeding. After 72 hours of breeding, the does were slaughtered and 10mL blood samples were collected for progesterone and 17β-estradiol serum level analyses. Other parameters, such as weight of uterus with ovaries, number of follicles and of corpora lutea, were obtained. Embryos were recovered by three flushings, per uterine corn, with Dulbecco extender (PBS. The recovered effluent was analyzed to find out structures and classify them according to morphology and age. No differences

  2. Avaliação da matriz nutricional da enzima fitase em rações contendo sorgo para poedeiras comerciais Evaluation of the nutritional matrix values for phytase enzyme in laying hens diets with sorghum

    Directory of Open Access Journals (Sweden)

    Elaine Cristina Ligeiro

    2009-10-01

    Full Text Available Avaliaram-se os efeitos da inclusão de fitase e de sua matriz nutricional em rações contendo sorgo sobre o desempenho das aves, a qualidade dos ovos, a ingestão e a excreção e retenção de fósforo e nitrogênio em poedeiras comerciais. Utilizaram-se 180 poedeiras comerciais, distribuídas em delineamento inteiramente ao acaso em esquema fatorial 2 × 2 + 1, com dois níveis de fitase (0 e 500 FTU/kg de ração e dois níveis de substituição do milho pelo sorgo (50 e 100% e uma ração testemunha (isenta de sorgo e fitase, constituindo cinco tratamentos com seis repetições de seis aves. As rações foram à base de milho e farelo de soja, sem fitase e sorgo, considerando a matriz nutricional da fitase. O desempenho e a qualidade dos ovos foram avaliados em quatro períodos de 28 dias. Ao final do experimento, um ensaio de metabolismo foi realizado para quantificar a ingestão, excreção e retenção aparente de fósforo e nitrogênio e avaliar a viabilidade econômica das rações. Ao considerar a matriz nutricional da fitase, as exigências em energia, cálcio, fósforo, proteína e aminoácidos foram atendidas, mesmo com a redução dos níveis nutricionais da dieta, e o desempenho e a qualidade dos ovos não foram comprometidos. A adição de fitase nas rações possibilitou reduzir todos os parâmetros econômicos avaliados. O sorgo pode substituir totalmente o milho e ser o único grão energético da dieta.The effects were assessed of including phytase and its nutritional matrix in diets containing sorghum on the performance of the birds, egg quality, intake and phosphorus excretion and retention in laying hens. One hundred and eighty laying hens were arranged in a randomized complete design in a 2 × 2 + 1 factorial arrangement with two phytase levels (0 and 500 FTU/kg diet, two levels of corn replacement for sorghum (50 and 100% and a control diet (without phytase and sorghum forming five treatments and six replications of

  3. Comportamento ingestivo e parâmetros sanguíneos em ovinos que receberam dietas contendo aditivos à base de extratos de própolis em pó

    Directory of Open Access Journals (Sweden)

    O.P. Prado-Calixto

    Full Text Available RESUMO Objetivou-se avaliar os efeitos do extrato de própolis (LLOSC2 sobre o comportamento ingestivo e os parâmetros sanguíneos em cordeiros alimentados com dieta concentrada. Foram utilizados quatro cordeiros machos, castrados, sem raça definida e com peso médio inicial de 32±1,92kg, mantidos em gaiolas metabólicas individuais durante todo o período experimental. O delineamento experimental foi em quadrado latino 4x4, com quatro animais, quatro dietas e quatro períodos experimentais. As dietas diferiram em relação à adição ou não de extratos de própolis à ração. As dietas testadas diferiam na adição de zero (controle, 1(88,16mg/g de flavonoides, duas (176,32mg/g de flavonoides ou três (264,48mg/g de flavonoides doses de aditivo à base de extrato de própolis LLOSC2. A dieta tinha relação volumoso:concentrado de 40:60 e foi formulada para ganhos de 250g. A ração concentrada era composta de milho e farelo de soja. O comportamento ingestivo dos animais foi observado por 24 horas, divididas em quatro períodos de seis horas. As coletas de sangue eram realizadas no último dia do período. Não houve efeito das doses LLOSC2 sobre o tempo despendido em alimentação, ruminação, ócio e ingestão de água. A duração do ciclo ruminativo foi maior nos animais que receberam duas doses de LLOSC2, e o número de movimentos mastigatórios também tendeu a aumentar no período que compreendia das 13 às 19h. Já a dieta contendo uma dose de LLOSC2 aumentou a duração da ruminação do bolo bem como o seu número total de mastigações no período de uma a sete horas. Houve uma diminuição nos níveis séricos de cortisol com a adição de três doses de LLOSC2. O hemograma, o leucograma, o perfil bioquímico e as imunoglobulinas não foram afetados pela inclusão das doses de LLSOC2. A administração de extrato de própolis LLOSC2 à dieta de ovinos não afetou seu comportamento ingestivo, os parâmetros hematol

  4. Translocation of Klebsiella sp. in mice fed an enteral diet containing prebiotics Translocação de Klebsiella sp. em camundongos alimentados com dieta enteral contendo prebióticos

    Directory of Open Access Journals (Sweden)

    Daniele Ferreira da Silva

    2009-04-01

    Full Text Available OBJECTIVE: This work aimed to evaluate the effect of fructooligosaccharide and inulin added to an enteral diet on the translocation of Klebsiella sp. in mice. METHODS: Four- to six-week-old Swiss albino mice were divided into nine groups and fed enteral diets containing different combinations of fructooligosaccharide, inulin, antibiotic and corticoid, inoculated or not with Klebsiella pneumoniae. On day 5, the animals of four groups were fed an enteral diet contaminated with approximately 10(10CFU/g of K. pneumoniae. At defined times, two animals of each group were sacrificed and their organs (spleen, heart, liver, lungs, and kidneys were aseptically collected, weighed, and analyzed for the presence of typical Klebsiella sp. colonies. RESULTS: A higher number of CFU/g of Klebsiella was detected in the organs of the animals in the immune-suppressed group fed the diet contaminated with K. pneumoniae and without prebiotics. Animals fed the diet enriched with fructooligosaccharide and inulin, at a concentration of 15.3mg/g of body weight, had a shorter period of Klebsiella sp. translocation, compared with those not fed prebiotics in the diet. CONCLUSION: The addition of fructooligosacharide and inulin in enterais diets at a concentration of 15.3mg/g of body weight resulted in the reduction of translocation of Klebsiella for spleen, heart, liver, lung and kidneys of mice that had received the diet contaminated associated or not with antibiotic and imunodepressor drug.OBJETIVO: Avaliar o efeito da administração de frutooligossacarídeo e inulina, adicionados à dieta enteral, na translocação de Klebsiella sp. em camundongos. MÉTODOS: Camundongos albinos suíços, com quatro a seis semanas de vida, foram divididos em nove grupos e tratados com dietas enterais contendo diferentes combinações de frutooligossacarídeos, inulina, antibiótico e corticóide, inoculadas ou não com Klebsiella pneumoniae. No quinto dia de experimento, os animais dos

  5. Dynamics of gas levels inside packages containing minimally processed Pera orange Dinâmica dos níveis gasosos dentro de embalagens contendo laranja Pera minimamente processada

    Directory of Open Access Journals (Sweden)

    Maria Cecília de Arruda Palharini

    2012-12-01

    Full Text Available The purpose of this study was to evaluate the changes in concentrations of O2 and CO2 inside packages of minimally processed Pera orange. Previously selected oranges that were washed, sanitized, and chilled were peeled using hydrothermal treatment (immersion of fruits in water at 50 °C for 8 minutes. The peeled oranges were then packed in five different plastic packages under passive and active modified atmosphere (5% O2 + 10% CO2 + 85% N2. The fruits were stored at 6 °C and 12 °C. The package headspace gas composition was evaluated for twelve days at 6 °C and nine days at 12 °C. The polypropylene film (32 µm promoted modified atmosphere similar to that initially injected (5% O2 + 10% CO2 + 85% N2 at 6 °C and 12 °C. With regard to the atmosphere modification system, the injection of a gas mixture anticipated achieving an equilibrium atmosphere inside the packages at 12 °C. At 6 °C, the gas composition inside the packages was kept close to that of the injection, but the equilibrium was not verified.O objetivo deste trabalho foi avaliar as mudanças nas concentrações de O2 e CO2 do interior de embalagens contendo laranja Pera minimamente processada. Laranjas previamente selecionadas, lavadas, sanitizadas e resfriadas foram descascadas por meio de tratamento hidrotérmico (imersão dos frutos em água a 50 °C por 8 minutos. Laranjas descascadas foram acondicionadas em cinco materiais de embalagem sob atmosfera modificada passiva e atmosfera modificada ativa (5% O2 + 10% CO2 + 85% N2. O armazenamento dos frutos foi realizado a 6 °C e 12 °C. A composição gasosa no interior das embalagens foi avaliada durante doze dias a 6 °C e durante 9 dias a 12 °C. O filme de polipropileno (32 µm propiciou atmosfera modificada semelhante injetada inicialmente (5% O2 + 10% CO2 + 85% N2 a 6 °C e 12 °C. Em relação ao sistema de modificação da atmosfera, a injeção de mistura gasosa antecipou a atmosfera de equilíbrio, dentro das embalagens

  6. Pigmentação de gemas de ovos de codornas japonesas alimentadas com rações contendo colorífico Egg yolk colour of japanese quail fed on diets with spice

    Directory of Open Access Journals (Sweden)

    Newton Tavares Escocard de Oliveira

    2007-10-01

    Full Text Available Objetivou-se neste trabalho avaliar, semanalmente, o grau de pigmentação de gemas de ovos de codornas japonesas alimentadas com rações contendo diferentes níveis de colorífico (163,8 mg bixina/100 g, no decorrer de quatro semanas. Utilizaram-se 240 codornas japonesas (Coturnix japonica fêmeas, em delineamento experimental em blocos inteiramente casualizados, com oito tratamentos, cinco repetições e seis codornas por unidade experimental. Os tratamentos, constituídos por oito rações experimentais resultantes da combinação de quatro níveis de colorífico na ração (0; 1,5; 3,0 e 4,5% e duas fontes energéticas (milho e quirera de arroz, foram distribuídos nas parcelas, enquanto que os quatro dias experimentais (7º, 14º, 21º e 28º constituíram as subparcelas. A equação de regressão estimada com o uso do modelo logarítmico explicou 96% da variação dos dados de escore colorimétrico das gemas. No 7º e 14º dia do experimento, os níveis de colorífico estimados que promoveram escores colorimétricos de gemas com padrão caipira (8,5 a 9,0 pontos foram de 1,5%, em rações à base de milho, e 3,0%, em rações à base de quirera de arroz. No 21º e 28º dia experimental, os valores estimados foram de 0,75% (rações com milho e 2,25% (rações com quirera. Em rações com 46,0% de milho ou quirera de arroz, o uso de níveis superiores a 3,0% de colorífico promoveu aumento das perdas de pigmento, pelas excretas, e conseqüente redução da capacidade de deposição de pigmentos nas gemas.One aimed in this work to evaluate , weekly, the egg yolk colour grade of japanese quails fed on diets with different levels of spice (163.8 mg bixin/100 g, in course of four weeks. Two hundred and forty japanese female quails (Coturnix japonica were used in a completely randomized block outline, with eight treatments, five replicates and six quails per experimental unit. The treatments, consisted of eight experimental diets resultant from

  7. Seleção de inoculantes à base de turfa contendo bactérias diazotróficas em duas variedades de arroz = Selection of peats inoculants with diazotrophic bacteria in two rice varieties

    Directory of Open Access Journals (Sweden)

    Vera Lúcia Divan Baldani

    2010-01-01

    Full Text Available O estudo consistiu em avaliar a sobrevivência e a eficiência das bactérias diazotróficas Herbaspirillum seropedicae, Burkholderia sp. e Azospirillum brasilense, inoculadas em dois tipos de turfas. A sobrevivência das bactérias foi determinada pelo método do NúmeroMais Provável (NMP, durante o armazenamento de até seis meses. A eficiência foi avaliada pela contribuição destas bactérias nos parâmetros agronômicos de acúmulo de massa seca e N-total dos grãos nas variedades de arroz IR42 e IAC4440. O experimento foi conduzido emvasos com solo, em delineamento inteiramente casualizado com três repetições, em arranjo fatorial 2 x 4. Os dados obtidos mostraram que o inoculante contendo a estirpe de Burkholderia sp. manteve o número de células viáveis em torno de 108 cel. g-1 de turfa no período testado, enquanto nos demais inoculantes este número ficou em torno de 106. Os ensaios de inoculação não mostraram diferenças significativas quanto à origem das turfas usadas como veículo sobre os parâmetros agronômicos e sobrevivência das bactérias. O tratamento que continha H. seropedicae manteve o acúmulo de massa seca e N-total dos grãos estatisticamente igual ao tratamento que recebeu 40 kg N ha-1, embora tenham sido observados aumentos de 13 e 19,4% nestes parâmetros na variedade IAC4440. Os resultados mostraram-se promissores quanto à utilização da prática de inoculação na cultura do arroz. The study consisted of a comparison of two-peat materials (Brazil and Canada containing different C-total content. The peats were inoculated with strains of Herbaspirillum seropedicae ZAE 94, Burkholderia sp. M130, and Azospirillum brasilense Sp109, and monitored during a period of six months in relation to variation on humidity and survival of bacteria in the inoculant. The quantification of viable cells in the inoculant was measured by the Most Probable Number (MPN method. The rice seeds were pelleted with the respective

  8. Desempenho e características de carcaça de cordeiros alimentados em comedouros privativos recebendo rações contendo semente de girassol Performance and carcass traits of lambs fed diets containing sunflower seed in creep feeding

    Directory of Open Access Journals (Sweden)

    Vicente de Paulo Macedo

    2008-11-01

    Full Text Available Avaliaram-se o desempenho e as características quali e quantitativas da carcaça de cordeiros alimentados com ração contendo semente de girassol. Utilizaram-se 16 cordeiros distribuídos aleatoriamente em um delineamento inteiramente casualizado com quatro tratamentos (0,00; 6,60; 13,20 ou 19,80% de semente de girassol na matéria natural, cada um com quatro repetições, totalizando 16 cordeiros. As dietas continham 2,65; 2,78; 2,89 e 2,93 Mcal/kg de energia metabolizável e 18,38; 18,75; 19,98 e 21,18% de proteína bruta, respectivamente, e foi fornecida ad libitum. Os cordeiros foram pesados a cada 14 dias e mantidos com as ovelhas até atingirem 28 kg, quando foram abatidos, após jejum de sólidos por 18 horas, para obtenção do peso vivo ao abate e registro do peso da carcaça quente e do conteúdo gastrintestinal, utilizados no cálculo do peso de corpo vazio. As carcaças foram mantidas por 24 horas em câmara frigorífica em temperatura de 5ºC para obtenção do peso de carcaça fria. Os níveis de semente de girassol na dieta não afetaram as características de desempenho dos cordeiros. No entanto, os pesos de carcaça quente e de carcaça fria; os pesos de pescoço, baixo, paleta, costela descoberta, costela, lombo; e os rendimentos comerciais de carcaça e costela descoberta, costela, lombo, paleta, pescoço e baixo sofreram efeito da adição da semente de girassol. O fornecimento de semente de girassol na dieta não influencia as características qualitativas e morfométricas da carcaça de cordeiros.Performance and quantitative and qualitative carcass traits of lambs fed with diets containing sunflower seed were evaluated. Sixteen lambs were randomly distributed to a completely randomized design with four diets (0.00, 6.60, 13.20 or 19.80% of sunflower seed, % as fed, with 4 replications. The diets contained 2.65, 2.78, 2.89 and 2.93 Mcal / kg of metabolize energy and 18.38, 18.75, 19.98 and 21.18% crude protein

  9. Comportamento ingestivo de cordeiros alimentados com dietas contendo diferentes níveis de fibra em detergente neutro Ingestive behavior of lambs fed with a diet of different levels of fiber in neutrol detergent

    Directory of Open Access Journals (Sweden)

    Adriano Ramos Cardoso

    2006-04-01

    Full Text Available Avaliou-se o efeito de diferentes níveis de fibra em detergente neutro (FDN, na dieta sobre o comportamento ingestivo de cordeiros Ile de France x Texel. Foram utilizados 20 cordeiros distribuídos em um delineamento experimental inteiramente casualizado, em um total de quatro tratamentos com cinco repetições, e alimentados à vontade com dietas que continham 25%, 31%, 37% e 43% de FDN. Foi utilizada uma ração em mistura completa de silagem de sorgo (AG 2005E e mistura concentrada constituída por farelo de soja, grão de milho quebrado e mistura mineral. As dietas eram isoprotéicas contendo 17% de PB. As dietas foram fornecidas duas vezes ao dia, às 8:00 e às 16:00 horas. O comportamento ingestivo foi determinado mediante observação visual, ocorrido durante 24 horas, a intervalos de 5 minutos, para se determinar o tempo despendido em alimentação, ruminação e ócio. O aumento do teor de fibra na ração não influenciou significativamente (P>0,05 os tempos despendidos em alimentação, ruminação, ócio e tempo de mastigação total. Houve efeito linear crescente sobre as variáveis eficiência de alimentação e de ruminação de FDN (P>0,05. Os ovinos confinados possuem hábito de alimentação predominantemente diurno e de ruminação noturno.The effect of different neutral detergent fiber (NDF levels in the diet on the Ile de France x Texel lambs ingestive behavior was evaluated. Twenty lambs distributed in a fully randomized experimental design were used, in a total of four treatments and five repetitions, fed ad libitum with 25%, 31%, 37% and 43% NDF diets. A ration in a complete mixing in sorghum silage (AG 2005 E and concentrate mixing of soybean meal, fragmented corn grains and mineral mixing was used. The diets were isoproteic (17% crude protein and were given twice a day, at 8 AM and 4 PM. The ingestive behavior was determined by observation, during 24 hours with 5 minutes intervals, to determine the time spent in

  10. Desempenho de frangos de corte alimentados com rações contendo diferentes níveis de cálcio suplementadas com fitase Performance of broilers fed diets with different calcium levels and supplemented with phytase

    Directory of Open Access Journals (Sweden)

    Daniella Carolina Zanardo Donato

    2011-10-01

    Full Text Available Um experimento foi conduzido para avaliar o efeito de rações contendo diferentes níveis de cálcio e suplementadas com fitase sobre o desempenho de frangos de corte nas fases inicial (1 a 21 dias, de crescimento (22 a 35 dias e final (36 a 42 dias. Foram utilizados 2.160 pintos de corte machos da linhagem AG Ross 308, de 1 a 42 dias de idade, distribuídos em 6 tratamentos, cada um com 6 repetições. Foi utilizado um delineamento inteiramente casualizado em esquema fatorial 3 × 2, com 3 níveis de fitase (0, 600 e 1.200 ftu/kg e 2 de cálcio (0,94 e 0,66%; 0,84 e 0,59%; e 0,78 e 0,54% para as fases inicial, de crescimento e final, respectivamente. As rações experimentais ainda tinham níveis reduzidos de fósforo disponível e níveis mínimos de proteína bruta. Ao final de cada fase, avaliaram-se o ganho de peso, o consumo de ração, a conversão alimentar e a mortalidade. Houve interação entre os níveis de fitase e de cálcio estudados para ganho de peso, consumo de ração e mortalidade nas três fases avaliadas. Os melhores resultados foram obtidos com a suplementação de fitase no nível de 1.200 ftu/kg de ração em associação aos menores níveis de cálcio. Nenhum resultado significativo foi observado para conversão alimentar. Os níveis nutricionais de cálcio podem ser reduzidos em 30% em dietas com baixos níveis de fósforo disponível e níveis mínimos de proteína bruta, desde que as dietas sejam suplementadas com 1.200 ftu/kg de fitase.An experiment was carried out to evaluate the effect of diets with different calcium levels and supplemented with phytase on the performance of broiler chickens in initial (1 to 21 days of age, growing (22 to 35 days of age and final (36 to 42 days of age phases. Two thousand one hundred and sixty male broilers from AG Ross 308 line, from 1 to 42 days old were distributed in 6 treatments, with 6 replicates each. A completely randomized design in a 3 × 2 factorial scheme was used

  11. High current ion sources

    International Nuclear Information System (INIS)

    Brown, I.G.

    1989-06-01

    The concept of high current ion source is both relative and evolutionary. Within the domain of one particular kind of ion source technology a current of microamperers might be 'high', while in another area a current of 10 Amperes could 'low'. Even within the domain of a single ion source type, what is considered high current performance today is routinely eclipsed by better performance and higher current output within a short period of time. Within their fields of application, there is a large number of kinds of ion sources that can justifiably be called high current. Thus, as a very limited example only, PIGs, Freemen sources, ECR sources, duoplasmatrons, field emission sources, and a great many more all have their high current variants. High current ion beams of gaseous and metallic species can be generated in a number of different ways. Ion sources of the kind developed at various laboratories around the world for the production of intense neutral beams for controlled fusion experiments are used to form large area proton deuteron beams of may tens of Amperes, and this technology can be used for other applications also. There has been significant progress in recent years in the use of microwave ion sources for high current ion beam generation, and this method is likely to find wide application in various different field application. Finally, high current beams of metal ions can be produced using metal vapor vacuum arc ion source technology. After a brief consideration of high current ion source design concepts, these three particular methods are reviewed in this paper

  12. Ion mobilities and ion-atom interaction potentials

    International Nuclear Information System (INIS)

    Gatland, I.R.

    1982-01-01

    The techniques for measuring the mobilities of ions in gases, relating interaction potentials to mobilities, and determining potentials from experimental mobilities are reviewed. Applications are presented for positive alkali ions and negative halogen ions in inert gases. (Auth.)

  13. Ion-beam technologies

    Energy Technology Data Exchange (ETDEWEB)

    Fenske, G.R. [Argonne National Lab., IL (United States)

    1993-01-01

    This compilation of figures and diagrams reviews processes for depositing diamond/diamond-like carbon films. Processes addressed are chemical vapor deposition (HFCVD, PACVD, etc.), plasma vapor deposition (plasma sputtering, ion beam sputtering, evaporation, etc.), low-energy ion implantation, and hybrid processes (biased sputtering, IBAD, biased HFCVD, etc.). The tribological performance of coatings produced by different means is discussed.

  14. Ion beam studies

    International Nuclear Information System (INIS)

    Freeman, J.H.; Chivers, D.J.; Gard, G.A.; Temple, W.

    1977-04-01

    A description of techniques for the production of intense beams of heavy ions is given. A table of recommended operational procedures for most elements is included. The ionisation of boron is considered in some detail because of its particular importance as a dopant for ion implantation. (author)

  15. Where do ions solvate?

    Indian Academy of Sciences (India)

    We study a simple model of ionic solvation inside a water cluster. The cluster is modeled as a spherical dielectric continuum. It is found that unpolarizable ions always prefer the bulk solvation. On the other hand, for polarizable ions, there exists a critical value of polarization above which surface solvation becomes ...

  16. Ion implantation of metals

    International Nuclear Information System (INIS)

    Dearnaley, G.

    1976-01-01

    In this part of the paper descriptions are given of the effects of ion implantation on (a) friction and wear in metals; and (b) corrosion of metals. In the study of corrosion, ion implantation can be used either to introduce a constituent that is known to convey corrosion resistance, or more generally to examine the parameters which control corrosion. (U.K.)

  17. Heavy ion fusion

    International Nuclear Information System (INIS)

    Bangerter, R.O.

    1986-01-01

    This report on the International Symposium on Heavy Ion Fusion held May 27-29, 1986 summarizes the problems and achievements in the areas of targets, accelerators, focussing, reactor studies, and system studies. The symposium participants recognize that there are large uncertainties in Heavy Ion Fusion but many of them are also optimistic that HIF may ultimately be the best approach to fusion

  18. High brightness ion source

    International Nuclear Information System (INIS)

    Dreyfus, R.W.; Hodgson, R.T.

    1975-01-01

    A high brightness ion beam is obtainable by using lasers to excite atoms or molecules from the ground state to an ionized state in increments, rather than in one step. The spectroscopic resonances of the atom or molecule are used so that relatively long wavelength, low power lasers can be used to obtain such ion beam

  19. Heavy ion inertial fusion

    International Nuclear Information System (INIS)

    Fessenden, T.J.; Friedman, A.

    1991-01-01

    This report describes the research status in the following areas of research in the field of heavy ion inertial fusion: (1) RF accelerators, storage rings, and synchrotrons; (2) induction linacs; (3) recirculation induction accelerator approach; (4) a new accelerator concept, the ''Mirrortron''; (5) general issues of transport, including beam merging, production of short, fat quadrupoles with nearly linear focusing, calculations of beam behaviour in image fields; 3-D electrostatic codes on drift compression with misalignments and transport around bends; (6) injectors, ion sources and RFQs, a.o., on the development of a 27 MHz RFQ to be used for the low energy portion of a new injector for all ions up to Uranium, and the development of a 2 MV carbon ion injector to provide 16 C + beams of 0.5 A each for ILSE; (7) beam transport from accelerator to target, reporting, a.o., the feasibility to suppress third-order aberrations; while Particle-in-Cell simulations on the propagation of a non-neutral ion beam in a low density gas identified photo-ionization by thermal X-rays from the target as an important source of defocusing; (9) heavy ion target studies; (10) reviewing experience with laser drivers; (11) ion cluster stopping and muon catalyzed fusion; (12) heavy ion systems, including the option of a fusion-fission burner. 1 tab

  20. Ion mobility sensor system

    Science.gov (United States)

    Xu, Jun; Watson, David B.; Whitten, William B.

    2013-01-22

    An ion mobility sensor system including an ion mobility spectrometer and a differential mobility spectrometer coupled to the ion mobility spectrometer. The ion mobility spectrometer has a first chamber having first end and a second end extending along a first direction, and a first electrode system that generates a constant electric field parallel to the first direction. The differential mobility spectrometer includes a second chamber having a third end and a fourth end configured such that a fluid may flow in a second direction from the third end to the fourth end, and a second electrode system that generates an asymmetric electric field within an interior of the second chamber. Additionally, the ion mobility spectrometer and the differential mobility spectrometer form an interface region. Also, the first end and the third end are positioned facing one another so that the constant electric field enters the third end and overlaps the fluid flowing in the second direction.

  1. Cryogenic surface ion traps

    International Nuclear Information System (INIS)

    Niedermayr, M.

    2015-01-01

    Microfabricated surface traps are a promising architecture to realize a scalable quantum computer based on trapped ions. In principle, hundreds or thousands of surface traps can be located on a single substrate in order to provide large arrays of interacting ions. To this end, trap designs and fabrication methods are required that provide scalable, stable and reproducible ion traps. This work presents a novel surface-trap design developed for cryogenic applications. Intrinsic silicon is used as the substrate material of the traps. The well-developed microfabrication and structuring methods of silicon are utilized to create simple and reproducible traps. The traps were tested and characterized in a cryogenic setup. Ions could be trapped and their life time and motional heating were investigated. Long ion lifetimes of several hours were observed and the measured heating rates were reproducibly low at around 1 phonon per second at a trap frequency of 1 MHz. (author) [de

  2. Molecular ion photofragment spectroscopy

    International Nuclear Information System (INIS)

    Bustamente, S.W.

    1983-11-01

    A new molecular ion photofragment spectrometer is described which features a supersonic molecular beam ion source and a radio frequency octapole ion trap interaction region. This unique combination allows several techniques to be applied to the problem of detecting a photon absorption event of a molecular ion. In particular, it may be possible to obtain low resolution survey spectra of exotic molecular ions by using a direct vibrational predissociation process, or by using other more indirect detection methods. The use of the spectrometer is demonstrated by measuring the lifetime of the O 2 + ( 4 π/sub u/) metastable state which is found to consist of two main components: the 4 π/sub 5/2/ and 4 π/sub -1/2/ spin components having a long lifetime (approx. 129 ms) and the 4 π/sub 3/2/ and 4 π/sub 1/2/ spin components having a short lifetime (approx. 6 ms)

  3. Ion Implantation of Polymers

    DEFF Research Database (Denmark)

    Popok, Vladimir

    2012-01-01

    The current paper presents a state-of-the-art review in the field of ion implantation of polymers. Numerous published studies of polymers modified by ion beams are analysed. General aspects of ion stopping, latent track formation and changes of structure and composition of organic materials...... are discussed. Related to that, the effects of radiothermolysis, degassing and carbonisation are considered. Specificity of depth distributions of implanted into polymers impurities is analysed and the case of high-fluence implantation is emphasised. Within rather broad topic of ion bombardment, the focus...... is put on the low-energy implantation of metal ions causing the nucleation and growth of nanoparticles in the shallow polymer layers. Electrical, optical and magnetic properties of metal/polymer composites are under the discussion and the approaches towards practical applications are overviewed....

  4. A novel ion imager for secondary ion mass spectrometry

    International Nuclear Information System (INIS)

    Matsumoto, Kazuya; Miyata, Kenji; Nakamura, Tsutomu

    1993-01-01

    This paper describes a new area detector for secondary ion mass spectrometry (SIMS) ion microscope, and its performance. The operational principle is based on detecting the change in potential of a floating photodiode caused by the ion-induced secondary-electron emission and the incoming ion itself. The experiments demonstrated that 10 1 -10 5 aluminum ions per pixel can be detected with good linear response. Moreover, relative ion sensitivities from hydrogen to lead were constant within a factor of 2. The performance of this area detector provides the potential for detection of kiloelectronvolt ion images with current ion microscopy

  5. Ion thermometers - nuclear reactor applications

    International Nuclear Information System (INIS)

    Rosenkranz, J.; Jakes, D.

    The principle is briefly described of ion thermometers and the effects are reported of radiation on the ion crystal properties. The results show that ion thermometers are applicable for in-core measurements. (J.P.)

  6. 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

  7. Laser-cooled atomic ions as probes of molecular ions

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Kenneth R.; Viteri, C. Ricardo; Clark, Craig R.; Goeders, James E.; Khanyile, Ncamiso B.; Vittorini, Grahame D. [Schools of Chemistry and Biochemistry, Computational Science and Engineering and Physics, Georgia Institute of Technology, Atlanta, GA 30332 (United States)

    2015-01-22

    Trapped laser-cooled atomic ions are a new tool for understanding cold molecular ions. The atomic ions not only sympathetically cool the molecular ions to millikelvin temperatures, but the bright atomic ion fluorescence can also serve as a detector of both molecular reactions and molecular spectra. We are working towards the detection of single molecular ion spectra by sympathetic heating spectroscopy. Sympathetic heating spectroscopy uses the coupled motion of two trapped ions to measure the spectra of one ion by observing changes in the fluorescence of the other ion. Sympathetic heating spectroscopy is a generalization of quantum logic spectroscopy, but does not require ions in the motional ground state or coherent control of the ion internal states. We have recently demonstrated this technique using two isotopes of Ca{sup +} [Phys. Rev. A, 81, 043428 (2010)]. Limits of the method and potential applications for molecular spectroscopy are discussed.

  8. Ion-Ion Plasmas Produced by Electron Beams

    Science.gov (United States)

    Fernsler, R. F.; Leonhardt, D.; Walton, S. G.; Meger, R. A.

    2001-10-01

    The ability of plasmas to etch deep, small-scale features in materials is limited by localized charging of the features. The features charge because of the difference in electron and ion anisotropy, and thus one solution now being explored is to use ion-ion plasmas in place of electron-ion plasmas. Ion-ion plasmas are effectively electron-free and consist mainly of positive and negative ions. Since the two ion species behave similarly, localized charging is largely eliminated. However, the only way to produce ion-ion plasmas at low gas pressure is to convert electrons into negative ions through two-body attachment to neutrals. While the electron attachment rate is large at low electron temperatures (Te < 1 eV) in many of the halogen gases used for processing, these temperatures occur in most reactors only during the afterglow when the heating fields are turned off and the plasma is decaying. By contrast, Te is low nearly all the time in plasmas produced by electron beams, and therefore electron beams can potentially produce ion-ion plasmas continuously. The theory of ion-ion plasmas formed by pulsed electron beams is examined in this talk and compared with experimental results presented elsewhere [1]. Some general limitations of ion-ion plasmas, including relatively low flux levels, are discussed as well. [1] See the presentation by D. Leonhardt et al. at this conference.

  9. Heavy-ion dosimetry

    International Nuclear Information System (INIS)

    Schimmerling, W.

    1980-03-01

    This lecture deals with some of the more important physical characteristics of relativistic heavy ions and their measurement, with beam delivery and beam monitoring, and with conventional radiation dosimetry as used in the operation of the BEVALAC biomedical facility for high energy heavy ions (Lyman and Howard, 1977; BEVALAC, 1977). Even so, many fundamental aspects of the interaction of relativistic heavy ions with matter, including important atomic physics and radiation chemical considerations, are not discussed beyond the reminder that such additional understanding is required before an adequte perspective of the problem can be attained

  10. Ion implantation technology

    CERN Document Server

    Downey, DF; Jones, KS; Ryding, G

    1993-01-01

    Ion implantation technology has made a major contribution to the dramatic advances in integrated circuit technology since the early 1970's. The ever-present need for accurate models in ion implanted species will become absolutely vital in the future due to shrinking feature sizes. Successful wide application of ion implantation, as well as exploitation of newly identified opportunities, will require the development of comprehensive implant models. The 141 papers (including 24 invited papers) in this volume address the most recent developments in this field. New structures and possible approach

  11. IN MEMORIAM ION VATAMANU

    Directory of Open Access Journals (Sweden)

    S.P. Palii

    2012-12-01

    Full Text Available A dreamer in his creative solitude, an objective and lucid analyst of history and contemporaneity, an energetic and decisive leader with an uncanny ability for crisis management – all these describe Ion Vatamanu. His wife Elena and daughters Mihaela, Mariana, Leontina treasure a personal universe in which the magical spark of Ion Vatamanu’s love and joy of life meld the everyday in and out of poetry. Ion Vatamanu’s instantaneous connection to the audiences and deeply felt words still touch the hearts of his many colleagues and friends. Downloads: 2

  12. Ion implantation for microelectronics

    International Nuclear Information System (INIS)

    Dearnaley, G.

    1977-01-01

    Ion implantation has proved to be a versatile and efficient means of producing microelectronic devices. This review summarizes the relevant physics and technology and assesses the advantages of the method. Examples are then given of widely different device structures which have been made by ion implantation. While most of the industrial application has been in silicon, good progress continues to be made in the more difficult field of compound semiconductors. Equipment designed for the industrial ion implantation of microelectronic devices is discussed briefly. (Auth.)

  13. Multivalent ion conducting solids

    Energy Technology Data Exchange (ETDEWEB)

    Imanaka, N. [Osaka Univ., Suita, Osaka (Japan). Dept. of Applied Chemistry

    2008-07-01

    Solid electrolytes possess important characteristics for industrial applications. Only a single ionic species can macroscopically migrate in these solids. This paper described a the new NASICON (M-Zr-Nb-P-O) type system, exhibiting an exceptionally high level of trivalent M3+ ion conductivity on polycrystalline solids. The partial substitution of the smaller higher valent Nb5+ ion for Zr4+ stabilized the NASICON phase and realized the M3+ ion conduction in the NASICON structure. It was concluded that the conductivities of the series are comparable to those of the practically applied solid electrolytes of oxide anion conductors of YSZ and CSZ. 3 refs., 2 figs.

  14. Heavy ion physics

    International Nuclear Information System (INIS)

    Kalpakchieva, R.; Cherepanov, E.A.

    1993-01-01

    The international school-seminar on heavy ion physics had been organized in Dubna in may of 1993. The scientific program of reports covers the following main topics: synthesis and properties of heavy nuclei; synthesis and investigation of properties of exotic nuclei; experiments with radioactive nuclear beams; interaction between complex nuclei at low and intermediate energies. It also includes reports on laser spectroscopy and exotic nuclear beams, on some application of heavy ion beams for the problems of solid state physics, on construction of multidetector facilities and on developing of heavy ion accelerator complexes. Short communication

  15. Compact microwave ion source

    International Nuclear Information System (INIS)

    Leung, K.N.; Walther, S.; Owren, H.W.

    1985-05-01

    A small microwave ion source has been fabricated from a quartz tube with one end enclosed by a two grid accelerator. The source is also enclosed by a cavity operated at a frequency of 2.45 GHz. Microwave power as high as 500 W can be coupled to the source plasma. The source has been operated with and without multicusp fields for different gases. In the case of hydrogen, ion current density of 200 mA/cm -2 with atomic ion species concentration as high as 80% has been extracted from the source

  16. Jet laser ion source

    International Nuclear Information System (INIS)

    Dem'yanov, A.V.; Sidorov, S.V.

    1994-01-01

    External laser injector of multicharged ions (MCI) is developed in which wide-aperture aberration-free wire gauze spherical shape electrodes are applied for effective MCI extraction from laser plasma and beam focusing. Axial plasma compression by solenoid magnetic field is used to reduce ion losses due to transverse movement of the scattering laser plasma. Transverse magnetic field created by another solenoid facilitates the effective laser plasma braking and consequently, leads to the narrowing of energy spectrum of plasma ions and its shift towards lower energies. 2 refs.; 3 figs

  17. Carbon Ion Therapy

    DEFF Research Database (Denmark)

    Bassler, Niels; Hansen, David Christoffer; Herrmann, Rochus

    On the importance of choice of target size for selective boosting of hypoxic tumor subvolumina in carbon ion therapy Purpose: Functional imaging methods in radiotherapy are maturing and can to some extent uncover radio resistant structures found within a tumour entity. Selective boost of identified...... effect. All cell lines investigated here did not reach an OER of 1, even for the smaller structures, which may indicate that the achievable dose average LET of carbon ions is too low, and heavier ions than carbon may be considered for functional LET-painting....

  18. Avaliação da resistência da pele de tilápia do Nilo (Oreochrmis niloticus nos sentidos longitudinal, transversal e diagonal, depois de submetida ao curtimento com sais de cromo e recurtimento com diferentes agentes curtentes = Evaluation of resistance of the Nile tilapia (Oreochromis niloticus skin in longitudinal, transversal and diagonal position after tanning with chromium salts and retanning with different tanning substances

    Directory of Open Access Journals (Sweden)

    Maria Luiza Rodrigues de Souza

    2006-07-01

    Full Text Available O objetivo do trabalho foi avaliar a resistência da pele da Tilápia do Nilo (Oreochromis niloticus no sentido longitudinal, transversal e diagonal, depois de curtida com sais de cromo e recurtida por diferentes técnicas de recurtimento. As peles foram distribuídas em delineamento inteiramente casualizado, em fatorial 3x3, sendo 3 técnicas de recurtimento (T1 = com 4% de sais de cromo; T2 = 6% com taninos vegetais e T3 = com 6% de taninos sintéticos e 3 posições de retirada dos corpos-de-prova (P1 = longitudinal; P2 = transversal e P3 = diagonal, com 6 repetições por tratamento, em triplicata. O couro foi considerado a unidade experimental. Para os testes dedeterminação da resistência à tração, ao alongamento e ao rasgamento progressivo, foi utilizado o dinamômetro EMIC. A espessura dos couros variou de 1,00 a 1,20 mm, não diferindo entre as técnicas de recurtimento. Não houve diferença significativa para tração quanto às técnicas de recurtimento, porém, quanto à posição de retirada dos corpos-de-prova, foi significativamente maior para transversal (11,92 N/mm2. A técnica de recurtimento e a posição não influenciaram norasgamento progressivo (variou de 24,47 a 29,12 N/mm. O couro na posição transversal apresentou maior alongamento independentemente da técnica aplicada, não diferindo apenas na técnica T2 para a posição longitudinal. A pele recurtida com sais de cromo e no sentido transversal apresentou maior resistência à tração e ao alongamento. O recurtimento e a posição não interferiram no rasgamento progressivo.The objective of this experiment was to evaluate the resistance of the Nile tilapia (Oreochromis niloticus skin in longitudinal, transversal and diagonal sections after tanning with chromium salts and re-tanning with different tanning substances. Skins were distributed in a totally randomized design, 3 by 3, with three re-tanning techniques (T1 = with 4% chromium salts; T2 = 6% vegetal

  19. Comportamento ingestivo em caprinos alimentados com dietas contendo cana-de-açúcar tratada com óxido de cálcio Ingestive behavior in goats fed diets containing sugar cane treated with calcium oxide

    Directory of Open Access Journals (Sweden)

    Gleidson Giordano Pinto de Carvalho

    2011-08-01

    Full Text Available Objetivou-se avaliar o efeito do tratamento da cana-de-açúcar com óxido de cálcio (CaO sobre o comportamento ingestivo em caprinos. Foram utilizados oito caprinos da raça Saanen, machos castrados, com peso corporal médio de 22,6 kg e 4 meses de idade, distribuídos em dois quadrados latinos 4 × 4, com quatro períodos experimentais de 14 dias. Os animais foram mantidos em baias individuais de 1,2 m², com piso ripado de madeira, providas de comedouros e bebedouros individuais. As dietas foram formuladas para ser isoproteicas e conter 14% de proteína bruta (PB e apresentaram 70% de cana-de-açúcar tratada com 0; 0,75; 1,5 ou 2,25% de óxido de cálcio (com base na matéria natural corrigida com 1% de ureia e 30% de concentrado fornecidas a vontade. A cana-de-açúcar com a adição das doses de óxido de cálcio, foi triturada em desintegradora estacionária, pesada e acondicionada em baldes plásticos de 50 L, tratada com o óxido de cálcio e fornecida aos animais após 24 horas de armazenamento. Os tempos despendidos em alimentação, ruminação (min/dia, min/kg MS e min/kg FDN e ócio (min/dia não foram afetados pela adição de óxido de cálcio à cana-de-açúcar. A adição de óxido de cálcio à cana-de-açúcar não influenciou a eficiência em alimentação e ruminação, mas provocou redução do tempo médio despendido por período de alimentação. O comportamento ingestivo de caprinos em crescimento não é afetado pela utilização de dietas contendo cana-de-açúcar tratada com até 2,25% de óxido de cálcio.The objective of this work was to evaluate the effect of sugar cane treated with calcium oxide (CaO on ingestive behavior in goats. It was used eight castrated male Saanen goats, with 22.6 kg average body weight and at four months of age, distributed in two 4 × 4 Latin squares, with four 14-day experimental periods. The animals were kept in individual 1.2-m² stalls, with wood battened floor, provided with

  20. Uso de misturas de adubos contendo ou não enxofre na adubação do cultivar IAC 16 de algodoeiro The effect of sulfur on 'IAC 16' cotton

    Directory of Open Access Journals (Sweden)

    Nelson M. Silva

    1981-01-01

    Full Text Available Durante quatro anos agrícolas, foi conduzido com o algodoeiro - cultivar IAC 16, ensaio de caráter permanente, de competição de misturas de adubos contendo ou não enxofre, em Latossolo Roxo, ácido, de baixa fertilidade, anteriormente ocupado com pastagem não adubada, no municipio de Guaíra (SP. A combinação de produtos comerciais, como sulfato de amônio, salitre-do-chile, nitrato de amônio, superfosfatos simples e triplo, e cloreto de potássio, permitiu ceder às plantas N e K em doses constantes e P e S em doses variáveis. No primeiro e no último ano agrícola, foram aplicadas pequenas quantidades de calcário dolomítico. A produtividade das plantas no primeiro ano agrícola foi muito baixa, mesmo nos níveis altos de adubação, o que confirma o risco de insucesso que se corre cultivando o algodoeiro em início de correção de solo ácido. O efeito do fósforo sobre a produção das plantas praticamente inexistiu nesse ano e foi de natureza quadrática após sucessivos acúmulos de adubos. A ação do enxofre se fez sentir desde o primeiro ano, aumentando com o tempo e com a efetivação do efeito das calagens. O superfosfato simples comportou-se como adubo misto, tendo proporcionado aumentos no teor de Ca trocável do solo e na concentração de Ca e S na folha do algodoeiro, após aplicações sucessivas. Através dos anos, proporcionou produtividades sistematicamente superiores às devidas ao superfosfato triplo. As maiores produções, entretanto, foram obtidas com a inclusão do sulfato de amônio em cobertura. Não se observou correlação satisfatória entre concentração de nutrientes na planta e níveis de produtividade, uma vez que K, S, N e P se acumularam nas folhas das plantas que não receberam PeSna adubação, devido provavelmente à pouca carga de capulhos formada nesse caso.The influence of the repeated applications of fertilizer mixtures containing P and S and of mixtures without S, was studied by a

  1. Avaliar clinicamente uma solução contendo 0,12% de clorexidina, 0,05% de cetilpiridínico, e 0,05% de fluoreto de sódio na formação da placa e manchamento dental

    OpenAIRE

    Silva, Wagner Chagas da

    2008-01-01

    Apesar de sua eficácia no combate de infecções orais, a pigmentação de dentes e língua associada ao uso de soluções de clorexedina é um dos efeitos adversos que mais desencoraja o uso deste antisséptico por tempo prolongado. O objetivo deste estudo foi analisar o efeito da solução para bochecho contendo 0,12% de clorexidina, 0,05% de cetilpiridínio e 0,05% de fluoreto de sódio, na atividade anti- placa e formação da pigmentação extrínseca dental e da língua. Participara...

  2. Padrão Nictemeral do pH Ruminal e Comportamento Alimentar de Cabras Leiteiras Alimentadas com Dietas Contendo Diferentes Relações Volumoso: Concentrado Nictemeral Pattern of Ruminal pH and Feeding Behavior of Dairy Goats Fed Diets with Different Roughage to Concentrate Ratio

    Directory of Open Access Journals (Sweden)

    André Luigi Gonçalves

    2001-12-01

    Full Text Available Os objetivos do presente estudo foram a caracterização do padrão nictemeral do pH ruminal e a avaliação do comportamento alimentar de cabras leiteiras alimentadas com dietas compostas por diferentes relações volumoso:concentrado. Foram utilizadas cinco cabras, com peso médio de 58 kg, não-lactantes, não-gestantes, fistuladas no rúmen, em cinco períodos experimentais. Cada animal foi observado em cada um dos cinco tratamentos, que consistiram das relações volumoso:concentrado de 100:0, 80:20, 60:40, 40:60 e 20:80, em um delineamento em quadrado latino 5×5. As dietas foram fornecidas a cada 6 horas, buscando amenizar a variação dos níveis de pH ruminal, durante o período de 24 horas, para todos os tratamentos. Após a adaptação dos animais às dietas experimentais, estes foram observados por um período de 48 horas, no qual foi mensurado o pH ruminal a cada hora, bem como em outro período de mesma duração, em que se observou o comportamento a cada 10 minutos. Foi constatado que o nível de concentrado crescente resultou em decréscimo sobre o pH, cujos valores decresceram mais drasticamente em níveis acima de 60%. Observou-se também o efeito de tratamento sobre tempo de alimentação, ruminação e ócio. O tempo de alimentação foi maior para as dietas contendo valores acima de 60% de volumoso. A dieta contendo 100% de volumoso apresentou maior tempo de ruminação e menor ócio, seguida das dietas contendo 80 e 60% de volumoso, enquanto aquelas contendo 40 e 20% apresentaram menor tempo de ruminação e maior ócio.The objectives of the present study were to characterize nictemeral pattern of ruminal pH and feed behavior of dairy goats fed diets presenting different ratios of roughage:concentrate. Five non pregnant non lactating goats, ruminally cannulated, and averaging 58 kg were used during the five experimental periods. A 5x5 Latin square was used to evaluate five treatments consisted of roughage to concentrate

  3. Atomic negative ions

    International Nuclear Information System (INIS)

    Brage, T.

    1991-01-01

    We review some of the recent progress in the studies of alkaline-earth, negative ions. Computations of autodetachment rates, electron affinities and transition wavelengths are discussed and some new and improved results are given

  4. Ion exchange phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Bourg, I.C.; Sposito, G.

    2011-05-01

    Ion exchange phenomena involve the population of readily exchangeable ions, the subset of adsorbed solutes that balance the intrinsic surface charge and can be readily replaced by major background electrolyte ions (Sposito, 2008). These phenomena have occupied a central place in soil chemistry research since Way (1850) first showed that potassium uptake by soils resulted in the release of an equal quantity of moles of charge of calcium and magnesium. Ion exchange phenomena are now routinely modeled in studies of soil formation (White et al., 2005), soil reclamation (Kopittke et al., 2006), soil fertilitization (Agbenin and Yakubu, 2006), colloidal dispersion/flocculation (Charlet and Tournassat, 2005), the mechanics of argillaceous media (Gajo and Loret, 2007), aquitard pore water chemistry (Tournassat et al., 2008), and groundwater (Timms and Hendry, 2007; McNab et al., 2009) and contaminant hydrology (Chatterjee et al., 2008; van Oploo et al., 2008; Serrano et al., 2009).

  5. Ion implantation control system

    International Nuclear Information System (INIS)

    Gault, R. B.; Keutzer, L. L.

    1985-01-01

    A control system is disclosed for an ion implantation system of the type in which the wafers to be implanted are mounted around the periphery of a disk which rotates and also moves in a radial direction relative to an ion beam to expose successive sections of each wafer to the radiation. The control system senses beam current which passes through one or more apertures in the disk and is collected by a Faraday cup. This current is integrated to obtain a measure of charge which is compared with a calculated value based upon the desired ion dosage and other parameters. The resultant controls the number of incremental steps the rotating disk moves radially to expose the adjacent sections of each wafer. This process is continued usually with two or more traverses until the entire surface of each wafer has been implanted with the proper ion dosage

  6. Sensing with Ion Channels

    CERN Document Server

    Martinac, Boris

    2008-01-01

    All living cells are able to detect and translate environmental stimuli into biologically meaningful signals. Sensations of touch, hearing, sight, taste, smell or pain are essential to the survival of all living organisms. The importance of sensory input for the existence of life thus justifies the effort made to understand its molecular origins. Sensing with Ion Channels focuses on ion channels as key molecules enabling biological systems to sense and process the physical and chemical stimuli that act upon cells in their living environment. Its aim is to serve as a reference to ion channel specialists and as a source of new information to non specialists who want to learn about the structural and functional diversity of ion channels and their role in sensory physiology.

  7. Ion implantation apparatus

    International Nuclear Information System (INIS)

    Forneris, J.L.; Hicks, W.W.; Keller, J.H.; McKenna, C.M.; Siermarco, J.A.; Mueller, W.F.

    1981-01-01

    The invention relates to ion bombardment or implantation apparatus. It comprises an apparatus for bombarding a target with a beam of ions, including an arrangement for measuring the ion beam current and controlling the surface potential of the target. This comprises a Faraday cage formed, at least in part, by the target and by walls adjacent to, and electrically insulated from, the target and surrounding the beam. There is at least one electron source for supplying electrons to the interior of the Faraday cage and means within the cage for blocking direct rectilinear radiation from the source to the target. The target current is measured and combined with the wall currents to provide a measurement of the ion beam current. The quantity of electrons supplied to the interior of the cage can be varied to control the target current and thereby the target surface potential. (U.K.)

  8. Electrostatic ion acoustic waves

    International Nuclear Information System (INIS)

    Hasegawa, A.

    1983-01-01

    In this paper, certain aspects of plasma physics are illustrated through a study of electrostatic ion acoustic waves. The paper consists of three Sections. Section II deals with linear properties of the ion acoustic wave including derivation of the dispersions relation with the effect of Landau damping and of an ambient magnetic field. The section also introduces the excitation processes of the ion acoustic wave due to an electron drift or to a stimulated Brillouin scattering. The nonlinear properties are introduced in Section III and IV. In Section III, incoherent nonlinear effects such as quasilinear and mode-coupling saturations of the instability are discussed. The coherent nonlinear effects such as the generation of ion acoustic solitons, shocks and weak double layers are presented in Section IV. (Auth.)

  9. Trapping radioactive ions

    CERN Document Server

    Kluge, Heinz-Jürgen

    2004-01-01

    Trapping devices for atomic and nuclear physics experiments with radioactive ions are becoming more and more important at accelerator facilities. While about ten years ago only one online Penning trap experiment existed, namely ISOLTRAP at ISOLDE/CERN, meanwhile almost every radioactive beam facility has installed or plans an ion trap setup. This article gives an overview on ion traps in the operation, construction or planing phase which will be used for fundamental studies with short-lived radioactive nuclides such as mass spectrometry, laser spectroscopy and nuclear decay spectroscopy. In addition, this article summarizes the use of gas cells and radiofrequency quadrupole (Paul) traps at different facilities as a versatile tool for ion beam manipulation like retardation, cooling, bunching, and cleaning.

  10. Ion plasma electron gun

    International Nuclear Information System (INIS)

    Wakalopulos, G.

    1976-01-01

    In the disclosed electron gun positive ions generated by a hollow cathode plasma discharge in a first chamber are accelerated through control and shield grids into a second chamber containing a high voltage cold cathode. These positive ions bombard a surface of the cathode causing the cathode to emit secondary electrons which form an electron beam having a distribution adjacent to the cathode emissive surface substantially the same as the distribution of the ion beam impinging upon the cathode. After passing through the grids and the plasma discharge chamber, the electron beam exits from the electron gun via a foil window. Control of the generated electron beam is achieved by applying a relatively low control voltage between the control grid and the electron gun housing (which resides at ground potential) to control the density of the positive ions bombarding the cathode

  11. Ion sensing method

    Science.gov (United States)

    Smith, Richard Harding; Martin, Glenn Brian

    2004-05-18

    The present invention allows the determination of trace levels of ionic substances in a sample solution (ions, metal ions, and other electrically charged molecules) by coupling a separation method, such as liquid chromatography, with ion selective electrodes (ISE) prepared so as to allow detection at activities below 10.sup.-6 M. The separation method distributes constituent molecules into fractions due to unique chemical and physical properties, such as charge, hydrophobicity, specific binding interactions, or movement in an electrical field. The separated fractions are detected by means of the ISE(s). These ISEs can be used singly or in an array. Accordingly, modifications in the ISEs are used to permit detection of low activities, specifically, below 10.sup.-6 M, by using low activities of the primary analyte (the molecular species which is specifically detected) in the inner filling solution of the ISE. Arrays constructed in various ways allow flow-through sensing for multiple ions.

  12. EPR of uranium ions

    International Nuclear Information System (INIS)

    Ursu, I.; Lupei, V.

    1984-02-01

    A review of the electron paramagnetic resonance data on the uranium ions is given. After a general account of the electronic structure of the uranium free atoms and ions, the influence of the external fields (magnetic field, crystal fields) is discussed. The main information obtained from EPR studies on the uranium ions in crystals are emphasized: identification of the valence and of the ground electronic state, determination of the structure of the centers, crystal field effects, role of the intermediate coupling and of the J-mixing, role of the covalency, determination of the nuclear spin, maqnetic dipole moment and electric quadrupole moment of the odd isotopes of uranium. These data emphasize the fact that the actinide group has its own identity and this is accutely manifested at the beginning of the 5fsup(n) series encompassed by the uranium ions. (authors)

  13. Trapping radioactive ions

    International Nuclear Information System (INIS)

    Kluge, H.-J.; Blaum, K.

    2004-01-01

    Trapping devices for atomic and nuclear physics experiments with radioactive ions are becoming more and more important at accelerator facilities. While about ten years ago only one online Penning trap experiment existed, namely ISOLTRAP at ISOLDE/CERN, meanwhile almost every radioactive beam facility has installed or plans an ion trap setup. This article gives an overview on ion traps in the operation, construction or planing phase which will be used for fundamental studies with short-lived radioactive nuclides such as mass spectrometry, laser spectroscopy and nuclear decay spectroscopy. In addition, this article summarizes the use of gas cells and radiofrequency quadrupole (Paul) traps at different facilities as a versatile tool for ion beam manipulation like retardation, cooling, bunching, and cleaning

  14. Ion exchange equilibrium constants

    CERN Document Server

    Marcus, Y

    2013-01-01

    Ion Exchange Equilibrium Constants focuses on the test-compilation of equilibrium constants for ion exchange reactions. The book first underscores the scope of the compilation, equilibrium constants, symbols used, and arrangement of the table. The manuscript then presents the table of equilibrium constants, including polystyrene sulfonate cation exchanger, polyacrylate cation exchanger, polymethacrylate cation exchanger, polysterene phosphate cation exchanger, and zirconium phosphate cation exchanger. The text highlights zirconium oxide anion exchanger, zeolite type 13Y cation exchanger, and

  15. Heavy ion accelerators

    International Nuclear Information System (INIS)

    Schmelzer, C.

    1974-01-01

    This review of the present state of work on heavy-ion accelerators pays particular attention to the requirements for nuclear research. It is divided into the following sections: single-particle versus collective acceleration, heavy-ion accelerators, beam quality, and a status report on the UNILAC facility. Among the topics considered are the recycling cyclotron, linacs with superconducting resonators, and acceleration to the GeV/nucleon range. (8 figures, 2 tables) (U.S.)

  16. Ion Mass Determination

    DEFF Research Database (Denmark)

    2010-01-01

    An apparatus (100) is described for determining the mass of ions, the apparatus configured to hold a plasma (101 ) having a plasma potential. The apparatus (100) comprises an electrode (102) having a surface extending in a surface plane and an insulator (104) interfacing with the electrode (102......, and a processing unit (108) configured to interpret the detected impact locations in terms of the mass of the impacting ions....

  17. Ion beam diagnosis

    International Nuclear Information System (INIS)

    Strehl, P.

    1994-04-01

    This report is an introduction to ion beam diagnosis. After a short description of the most important ion beam parameters measurements of the beam current by means of Faraday cups, calorimetry, and beam current transformers and measurements of the beam profile by means of viewing screens, profile grids and scanning devices, and residual gas ionization monitors are described. Finally measurements in the transverse and longitudinal phase space are considered. (HSI)

  18. Ion implantation - an introduction

    International Nuclear Information System (INIS)

    Townsend, P.D.

    1986-01-01

    Ion implantation is a widely used technique with a literature that covers semiconductor production, surface treatments of steels, corrosion resistance, catalysis and integrated optics. This brief introduction outlines advantages of the technique, some aspects of the underlying physics and examples of current applications. Ion implantation is already an essential part of semiconductor technology while in many other areas it is still in an early stage of development. The future scope of the subject is discussed. (author)

  19. Produção de leite, consumo e digestibilidade aparente dos nutrientes, pH e concentração de amônia ruminal em vacas lactantes recebendo rações contendo silagem de milho e fenos de alfafa e de capim-coastcross

    Directory of Open Access Journals (Sweden)

    Moreira Andréia Luciane

    2001-01-01

    Full Text Available Utilizaram-se 10 vacas lactantes HPC e mestiças H*Z, com 55 dias de parição, peso médio de 540 kg, distribuídas em um delineamento em switch-back com o objetivo de avaliar a produção e a composição do leite, o consumo e a digestibilidade aparente de matéria seca (MS, matéria orgânica (MO, fibra em detergente neutro (FDN, proteína bruta (PB, carboidratos totais (CT e extrato etéreo (EE, e o pH e a concentração de amônia ruminal. Os animais foram alimentados ad libitum com cinco dietas contendo silagem de milho (SM, feno de alfafa (FA, feno de capim-coastcross (FCC, ½ FA+½ SM, ½ FCC+1/2 SM, na proporção de 60%, da ração total (base de matéria seca. Os consumos dos nutrientes não foram influenciados pelas dietas. As digestibilidades aparentes de MS, PB e FDN foram maiores para as dietas contendo silagem de milho. O pH e a concentração de amônia do líquido ruminal não foram influenciados pelas dietas, porém observou-se resposta quadrática para o tempo de coletas. Registrou-se maior produção de leite para os animais que receberam silagem de milho. Os teores de proteína bruta e gordura do leite não foram influenciados pelas dietas.

  20. Ion-specific thermodynamical properties of aqueous proteins

    Directory of Open Access Journals (Sweden)

    Eduardo R.A. Lima

    2010-03-01

    Full Text Available Ion-specific interactions between two colloidal particles are calculated using a modified Poisson-Boltzmann (PBequationandMonteCarlo(MCsimulations. PBequationspresentgoodresultsofionicconcentration profiles around a macroion, especially for salt solutions containing monovalent ions. These equations include not only electrostatic interactions, but also dispersion potentials originated from polarizabilities of ions and proteins. This enables us to predict ion-specific properties of colloidal systems. We compared results obtained from the modified PB equation with those from MC simulations and integral equations. Phase diagrams and osmotic second virial coefficients are also presented for different salt solutions at different pH and ionic strengths, in agreement with the experimental results observed Hofmeister effects. In order to include the water structure and hydration effect, we have used an effective interaction obtained from molecular dynamics of each ion and a hydrophobic surface combined with PB equation. The method has been proved to be efficient and suitable for describing phenomena where the water structure close to the interface plays an essential role. Important thermodynamic properties related to protein aggregation, essential in biotechnology and pharmaceutical industries, can be obtained from the method shown here.Interações íon-específicas (dependentes do tipo de íon presente em solução entre duas partículas coloidais são calculadas usando a equação de Poisson-Boltzmann (PB modificada e simulações de Monte Carlo (MC. As equações de PB apresentam bons resultados de perfis de concentração nas proximidades de um macro-íon, principalmente para soluções salinas contendo íons monovalentes. Estas equações incluem não só interações eletrostáticas, mas também potenciais de dispersão, que têm origem nas polarizabilidades de íons e proteínas, permitindo a predição de propriedades íon-específicas de

  1. 2010 ion run: completed!

    CERN Multimedia

    CERN Bulletin

    2010-01-01

    After a very fast switchover from protons to lead ions, the LHC has achieved performances that allowed the machine to exceed both peak and integrated luminosity by a factor of three. Thanks to this, experiments have been able to produce high-profile results on ion physics almost immediately, confirming that the LHC was able to keep its promises for ions as well as for protons.   First direct observation of jet quenching. A seminar on 2 December was the opportunity for the ALICE, ATLAS and CMS collaborations to present their first results on ion physics in front of a packed auditorium. These results are important and are already having a major impact on the understanding of the physics processes that involve the basic constituents of matter at high energies. In the ion-ion collisions, the temperature is so high that partons (quarks and gluons), which are usually constrained inside the nucleons, are deconfined to form a highly dense and hot soup known as quark-gluon plasma (QGP). The existence of ...

  2. Collective focusing ion accelerator

    International Nuclear Information System (INIS)

    Goldin, F.J.

    1986-01-01

    The principal subject of this dissertation is the trapping confinement of pure electron plasmas in bumpy toroidal magnetic fields, with particular attention given to the trapping procedure and the behavior of the plasma during the final equilibrium. The most important aspects of the equilibrium studied were the qualitative nature of the plasma configuration and motion and its density, distribution and stability. The motivation for this study was that an unneutralized cloud of electrons contained in a toroidal system, sufficiently dense and stable, may serve to electrostatically focus ions (against centrifugal and self space charge forces) in a cyclic ion accelerator. Such an accelerator, known as a Collective Focusing Ion Accelerator (CFIA) could be far smaller than conventional designs (which use external magnetic fields directly to focus the ions) due to the smaller gyro-radium of an electron in a magnetic field of given strength. The electron cloud generally drifted poloidally at a finite radius from the toroidal minor axis. As this would preclude focusing ions with such clouds, damping this motion was investigated. Finite resistance in the normally perfectly conductive vessel wall did this. In further preparation for a working CFIA, additional experiments studied the effect of ions on the stability of the electron cloud

  3. Ion mixing and numerical simulation of different ions produced in the ECR ion source

    International Nuclear Information System (INIS)

    Shirkov, G.D.

    1996-01-01

    This paper is to continue theoretical investigations and numerical simulations in the physics of ECR ion sources within the CERN program on heavy ion acceleration. The gas (ion) mixing effect in ECR sources is considered here. It is shown that the addition of light ions to the ECR plasma has three different mechanisms to improve highly charged ion production: the increase of confinement time and charge state of highly ions as the result of ion cooling; the concentration of highly charged ions in the central region of the source with high energy and density of electrons; the increase of electron production rate and density of plasma. The numerical simulations of lead ion production in the mixture with different light ions and different heavy and intermediate ions in the mixture with oxygen, are carried out to predict the principal ECR source possibilities for LHC applications. 18 refs., 23 refs

  4. Influence of calcinable cylinders cast in cobalt-chromium alloy on the passivity of implant-supported frameworks = Influência de cilindros calcináveis fundidos em cobalto-cromo na passividade de próteses implanto-suportadas

    Directory of Open Access Journals (Sweden)

    Triches, Diego Fernandes

    2009-01-01

    Full Text Available Objetivo: Este trabalho avaliou a influência da utilização de cilindros calcináveis no grau de passividade de infra-estruturas que simulam uma prótese parcial fixa de três elementos sobre dois implantes. Metodologia: Foram utilizados dois implantes de hexágono externo de 3,75 mm×10 mm, com seus respectivos pilares intermediários, fixados numa base de aço, formando o modelomestre. A partir disto, foram fabricadas dez infra-estruturas em liga de cobalto-cromo através da técnica de fundição por indução. Foram criados dois grupos: Grupo 1 utilizando cilindros pré-usinados para a fabricação de cinco infra-estruturas; Grupo 2 cinco infra-estruturas fundidas com cilindros de plástico calcináveis. Para avaliação da passividade foram utilizados extensômetros colados na região oclusal e cervical do pôntico das infra-estruturas. A medição foi realizada no momento do aperto do segundo parafuso protético com torque de 10Ncm. Os dados foram analisados pelo teste t de Student (a=0,05. Resultados: As médias (desvio-padrão dos grupos foram de 39,16 (24,74 mV/V no Grupo 1 e 43,76 (21,13 mV/V no Grupo 2. Não houve diferença estatisticamente significante entre os grupos (P=0,815. Conclusão: Considerando-se as limitações deste trabalho, sugere-se que o uso de cilindros calcináveis obtém o mesmo grau de passividade que o uso de cilindros pré-usinados

  5. Biomaterials modification by ion beam

    International Nuclear Information System (INIS)

    Zhang Tonghe; Yi Zhongzhen; Zhang Xu; Wu Yuguang

    2001-01-01

    Ion beam technology is one of best ways for the modification of biomaterials. The results of ion beam modification of biomaterials are given. The method and results of improved biocompatibility are indicated by ion beam technology. The future development of ion beam modification of biomaterials is discussed

  6. Ion-selective electrode reviews

    CERN Document Server

    Thomas, J D R

    1983-01-01

    Ion-Selective Electrode Reviews, Volume 5 is a collection of articles that covers ion-speciation. The book aims to present the advancements of the range and capabilities of selective ion-sensors. The topics covered in the selection are neutral carrier based ion-selective electrodes; reference electrodes and liquid junction effects in ion-selective electrode potentiometry; ion transfer across water/organic phase boundaries and analytical; and carbon substrate ion-selective electrodes. The text will be of great use to chemists and chemical engineers.

  7. Ion optics of RHIC EBIS

    Energy Technology Data Exchange (ETDEWEB)

    Pikin, A.; Alessi, J.; Beebe, E.; Kponou, A.; Okamura, M.; Raparia, D.; Ritter, J.; Tan, Y.; Kuznetsov, G.

    2011-09-10

    RHIC EBIS has been commissioned to operate as a versatile ion source on RHIC injection facility supplying ion species from He to Au for Booster. Except for light gaseous elements RHIC EBIS employs ion injection from several external primary ion sources. With electrostatic optics fast switching from one ion species to another can be done on a pulse to pulse mode. The design of an ion optical structure and the results of simulations for different ion species are presented. In the choice of optical elements special attention was paid to spherical aberrations for high-current space charge dominated ion beams. The combination of a gridded lens and a magnet lens in LEBT provides flexibility of optical control for a wide range of ion species to satisfy acceptance parameters of RFQ. The results of ion transmission measurements are presented.

  8. Ion beam inertial fusion

    International Nuclear Information System (INIS)

    Bangerter, R.O.

    1995-01-01

    About twenty years ago, A. W. Maschke of Brookhaven National Laboratory and R. L. Martin of Argonne National Laboratory recognized that the accelerators that have been developed for high energy and nuclear physics are, in many ways, ideally suited to the requirements of inertial fusion power production. These accelerators are reliable, they have a long operating life, and they can be efficient. Maschke and Martin noted that they can focus ion beams to small focal spots over distances of many meters and that they can readily operate at the high pulse repetition rates needed for commercial power production. Fusion, however, does impose some important new constraints that are not important for high energy or nuclear physics applications. The most challenging new constraint from a scientific standpoint is the requirement that the accelerator deliver more than 10 14 W of beam power to a small quantity (less than 100 mg) of matter. The most challenging constraint from an engineering standpoint is accelerator cost. Maschke showed theoretically that accelerators could produce adequate work. Heavy-ion fusion is widely recognized to be a promising approach to inertial fusion power production. It provides an excellent opportunity to apply methods and technology developed for basic science to an important societal need. The pulsed-power community has developed a complementary, parallel approach to ion beam fusion known as light-ion fusion. The talk will discuss both heavy-ion and light-ion fusion. It will explain target physics requirements and show how they lead to constraints on the usual accelerator parameters such as kinetic energy, current, and emittance. The talk will discuss experiments that are presently underway, specifically experiments on high-current ion sources and injectors, pulsed-power machines recirculating induction accelerators, and transverse beam combining. The talk will give a brief description of a proposed new accelerator called Elise

  9. Ion-selective electrode reviews

    CERN Document Server

    Thomas, J D R

    1985-01-01

    Ion-Selective Electrode Reviews, Volume 7 is a collection of papers that covers the applications of electrochemical sensors, along with the versatility of ion-selective electrodes. The coverage of the text includes solid contact in membrane ion-selective electrodes; immobilized enzyme probes for determining inhibitors; potentiometric titrations based on ion-pair formation; and application of ion-selective electrodes in soil science, kinetics, and kinetic analysis. The text will be of great use to chemists and chemical engineers.

  10. Clues From Pluto's Ions

    Science.gov (United States)

    Kohler, Susanna

    2016-05-01

    Nearly a year ago, in July 2015, the New Horizons spacecraft passed by the Pluto system. The wealth of data amassed from that flyby is still being analyzed including data from the Solar Wind Around Pluto (SWAP) instrument. Recent examination of this data has revealedinteresting new information about Plutos atmosphere and how the solar wind interacts with it.A Heavy Ion TailThe solar wind is a constant stream of charged particles released by the Sun at speeds of around 400 km/s (thats 1 million mph!). This wind travels out to the far reaches of the solar system, interacting with the bodies it encounters along the way.By modeling the SWAP detections, the authors determine the directions of the IMF that could produce the heavy ions detected. Red pixels represent IMF directions permitted. No possible IMF could reproduce the detections if the ions are nitrogen (bottom panels), and only retrograde IMF directions can produce the detections if the ions are methane. [Adapted from Zirnstein et al. 2016]New Horizons data has revealed that Plutos atmosphere leaks neutral nitrogen, methane, and carbon monoxide molecules that sometimes escape its weak gravitational pull. These molecules become ionized and are subsequently picked up by the passing solar wind, forming a tail of heavy ions behind Pluto. The details of the geometry and composition of this tail, however, had not yet been determined.Escaping MethaneIn a recent study led by Eric Zirnstein (Southwest Research Institute), the latest analysis of data from the SWAP instrument on board New Horizons is reported. The team used SWAPs ion detections from just after New Horizons closest approach to Pluto to better understand how the heavy ions around Pluto behave, and how the solar wind interacts with Plutos atmosphere.In the process of analyzing the SWAP data, Zirnstein and collaborators first establish what the majority of the heavy ions picked up by the solar wind are. Models of the SWAP detections indicate they are unlikely

  11. Study of ion exchange equilibrium and determination of heat of ion exchange by ion chromatography

    International Nuclear Information System (INIS)

    Liu Kailu; Yang Wenying

    1996-01-01

    Ion chromatography using pellicularia ion exchange resins and dilute solution can be devoted to the study of ion exchange thermodynamics and kinetics. Ion exchange equilibrium equation was obtained, and examined by the experiments. Based on ion exchange equilibrium, the influence of eluent concentration and resin capacity on adjusted retention volumes was examined. The effect of temperature on adjusted retention volumes was investigated and heats of ion exchange of seven anions were determined by ion chromatography. The interaction between anions and skeleton structure of resins were observed

  12. Ion nitriding of aluminium

    International Nuclear Information System (INIS)

    Fitz, T.

    2002-09-01

    The present study is devoted to the investigation of the mechanism of aluminium nitriding by a technique that employs implantation of low-energy nitrogen ions and diffusional transport of atoms. The nitriding of aluminium is investigated, because this is a method for surface modification of aluminium and has a potential for application in a broad spectrum of fields such as automobile, marine, aviation, space technologies, etc. However, at present nitriding of aluminium does not find any large scale industrial application, due to problems in the formation of stoichiometric aluminium nitride layers with a sufficient thickness and good quality. For the purposes of this study, ion nitriding is chosen, as an ion beam method with the advantage of good and independent control over the process parameters, which thus can be related uniquely to the physical properties of the resulting layers. Moreover, ion nitriding has a close similarity to plasma nitriding and plasma immersion ion implantation, which are methods with a potential for industrial application. (orig.)

  13. The ion circus

    Energy Technology Data Exchange (ETDEWEB)

    Minaya Ramirez, Enrique [GSI Helmholtzzentrum, Darmstadt (Germany); Lunney, David [CSNSM- IN2P3/CNRS, Universite de Paris-Sud, Orsay (France)

    2010-07-01

    The ability to prepare radioactive beams for experiments in nuclear structure has seen important developments in recent years. The use of ion traps and buffer-gas cooling now enables the accumulation and purification of even short-lived nuclides. This is a key point for future installations since higher intensity also brings increased isobaric contamination which can be disastrous for background. Until now, the development of beam cooler/bunchers has relied on linear (radiofrequency quadrupole) Paul traps. In this contribution we describe the progress in developing a novel circular Paul trap. The ion circus, so named for its ability to trap ions at different positions along the ring circumference and to eject them in either perpendicular or tangential direction, has also been designed to cool and mass separate the ions over a longer flight path. The resolving power is increased as the ions orbit in the ring and are cooled with buffer gas at a much lower pressure. The first prototype is now under test in Orsay. We report results of the first tests and the future program.

  14. Inverted magnetron ion source

    International Nuclear Information System (INIS)

    Singh, B.; Boyarsky, D.

    1985-01-01

    The present invention provides, in a preferred embodiment, a cylindrical stainless steel cathode with end pieces thereon to form a cathode chamber within. In addition, in a preferred embodiment, there is a stainless steel rod which passes axially through the cathode chamber and which is electrically insulated therefrom at the end pieces. The stainless steel cathode has first and second apertures formed therein with the first to be connected to a source of ionizable gas and the second to act as the opening through which there passes a stream of ions to an ion beam target. A magnetic flux source is coupled to the cathode chamber to pass magnetic flux therethrough and a voltage source is connected between the anode and the cathode to provide an electrostatic field therebetween whereby when ionizable gas is fed into the cathode chamber, it is ionized and a stream of ions emanates from the second aperture. In a preferred embodiment there is further provided an electrostatic ion focusing means to focus the ion stream emanating from the second aperture

  15. Majority ion heating near the ion-ion hybrid layer in tokamaks

    International Nuclear Information System (INIS)

    Phillips, C.K.; Hosea, J.C.; Ignat, D.; Majeski, R.; Rogers, J.H.; Schilling, G.; Wilson, J.R.

    1995-08-01

    Efficient direct majority ion heating in a deuterium-tritium (D-T) reactor-grade plasma via absorption of fast magnetosonic waves in the ion cyclotron range of frequencies (ICRF) is discussed. Majority ion heating results from resonance overlap between the cyclotron layers and the D-T ion-ion hybrid layer in hot, dense plasmas for fast waves launched with high parallel wavenumbers. Analytic and numerical models are used to explore the regime in ITER plasmas

  16. Ion channels versus ion pumps: the principal difference, in principle.

    Science.gov (United States)

    Gadsby, David C

    2009-05-01

    The incessant traffic of ions across cell membranes is controlled by two kinds of border guards: ion channels and ion pumps. Open channels let selected ions diffuse rapidly down electrical and concentration gradients, whereas ion pumps labour tirelessly to maintain the gradients by consuming energy to slowly move ions thermodynamically uphill. Because of the diametrically opposed tasks and the divergent speeds of channels and pumps, they have traditionally been viewed as completely different entities, as alike as chalk and cheese. But new structural and mechanistic information about both of these classes of molecular machines challenges this comfortable separation and forces its re-evaluation.

  17. Heavy-ion radiography

    International Nuclear Information System (INIS)

    Fabrikant, J.I.; Tobias, C.A.; Holley, W.R.; Benton, E.V.

    1981-01-01

    Heavy-particle radiography has clinical potential as a newly developed noninvasive low-dose imaging procedure that provides increased resolution of minute density differences in soft tissues of the body. The method utilizes accelerated high-energy ions, primarily carbon and neon, at the Bevalac accelerator at the Lawrence Berkeley Laboratory. The research program for medicine utilizes heavy-ion radiography for low-dose mammography, for treatment planning for cancer patients, and for imaging and accurate densitometry of skeletal structures, brain and spinal neoplasms, and the heart. The potential of heavy-ion imaging, and particularly reconstruction tomography, is now proving to be an adjunct to existing diagnostic imaging procedures in medicine, both for applications to the diagnosis, management and treatment of clinical cancer in man, and for the early detection of small soft-tissue tumors at low radiation dose

  18. Heavy ion inertial fusion

    International Nuclear Information System (INIS)

    Keefe, D.; Sessler, A.M.

    1980-01-01

    Inertial fusion has not yet been as well explored as magnetic fusion but can offer certain advantages as an alternative source of electric energy for the future. Present experiments use high-power beams from lasers and light-ion diodes to compress the deuterium-tritium (D-T) pellets but these will probably be unsuitable for a power plant. A more promising method is to use intense heavy-ion beams from accelerator systems similar to those used for nuclear and high-energy physics; the present paper addresses itself to this alternative. As will be demonstrated the very high beam power needed poses new design questions, from the ion-source through the accelerating system, the beam transport system, to the final focus. These problems will require extensive study, both theoretically and experimentally, over the next several years before an optimum design for an inertial fusion driver can be arrived at. (Auth.)

  19. Acceleration of radioactive ions

    International Nuclear Information System (INIS)

    Laxdal, R.E.

    2003-01-01

    There is an intense interest world-wide in the use of radioactive ion beams (RIBs) for experiment. In many existing or proposed facilities ions are produced or collected at source potential, ionized and re-accelerated. Within the past year three new ISOL based facilities have added dedicated post-accelerators to deliver accelerated RIBs to experiment. The paper gives an overview of RIB accelerators present and future, and explores the inherent features in the various acceleration methods with an emphasis on heavy ion linacs. The ISAC-I and ISAC-II post-accelerators are discussed as examples. Commissioning results and initial operating experience with ISAC-I will be presented

  20. Ion accelerators for space

    International Nuclear Information System (INIS)

    Slobodrian, R.J.; Potvin, L.

    1991-01-01

    The main purpose of the accelerators is to allow ion implantation in space stations and their neighborhoods. There are several applications of interest immediately useful in such environment: as ion engines and thrusters, as implanters for material science and for hardening of surfaces (relevant to improve resistance to micrometeorite bombardment of exposed external components), production of man made alloys, etc. The microgravity environment of space stations allows the production of substances (crystalline and amorphous) under conditions unknown on earth, leading to special materials. Ion implantation in situ of those materials would thus lead uninterruptedly to new substances. Accelerators for space require special design. On the one hand it is possible to forego vacuum systems simplifying the design and operation but, on the other hand, it is necessary to pay special attention to heat dissipation. Hence it is necessary to construct a simulator in vacuum to properly test prototypes under conditions prevailing in space

  1. Heavy ion inertial fusion

    International Nuclear Information System (INIS)

    Keefe, D.; Sessler, A.M.

    1980-07-01

    Inertial fusion has not yet been as well explored as magnetic fusion but can offer certain advantages as an alternative source of electric energy for the future. Present experiments use high-power beams from lasers and light-ion diodes to compress the deuterium-tritium (D-T) pellets but these will probably be unsuitable for a power plant. A more promising method is to use intense heavy-ion beams from accelerator systems similar to those used for nuclear and high-energy physics; the present paper addresses itself to this alternative. As will be demonstrated the very high beam power needed poses new design questions, from the ion source through the accelerating system, the beam transport system, to the final focus. These problems will require extensive study, both theoretically and experimentally, over the next several years before an optimum design for an inertial fusion driver can be arrived at

  2. Ion cyclotron resonance heating

    International Nuclear Information System (INIS)

    Tajima, T.

    1982-01-01

    Ion cyclotron resonance heating of plasmas in tokamak and EBT configurations has been studied using 1-2/2 and 2-1/2 dimensional fully self-consistent electromagnetic particle codes. We have tested two major antenna configurations; we have also compared heating efficiencies for one and two ion species plasmas. We model a tokamak plasma with a uniform poloidal field and 1/R toroidal field on a particular q surface. Ion cyclotron waves are excited on the low field side by antennas parallel either to the poloidal direction or to the toroidal direction with different phase velocities. In 2D, minority ion heating (vsub(perpendicular)) and electron heating (vsub(parallel),vsub(perpendicular)) are observed. The exponential electron heating seems due to the decay instability. The minority heating is consistent with mode conversion of fast Alfven waves and heating by electrostatic ion cyclotron modes. Minority heating is stronger with a poloidal antenna. The strong electron heating is accompanied by toroidal current generation. In 1D, no thermal instability was observed and only strong minority heating resulted. For an EBT plasma we model it by a multiple mirror. We have tested heating efficiency with various minority concentrations, temperatures, mirror ratios, and phase velocities. In this geometry we have beach or inverse beach heating associated with the mode conversion layer perpendicular to the toroidal field. No appreciable electron heating is observed. Heating of ions is linear in time. For both tokamak and EBT slight majority heating above the collisional rate is observed due to the second harmonic heating. (author)

  3. Ion-selective electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Mikhelson, Konstantin N. [St. Petersburg State Univ. (Russian Federation). Ion-Selective Electrode Laboratory

    2013-06-01

    Ion-selective electrodes (ISEs) have a wide range of applications in clinical, environmental, food and pharmaceutical analysis as well as further uses in chemistry and life sciences. Based on his profound experience as a researcher in ISEs and a course instructor, the author summarizes current knowledge for advanced teaching and training purposes with a particular focus on ionophore-based ISEs. Coverage includes the basics of measuring with ISEs, essential membrane potential theory and a comprehensive overview of the various classes of ion-selective electrodes. The principles of constructing ISEs are outlined, and the transfer of methods into routine analysis is considered.

  4. Ion beam texturing

    Science.gov (United States)

    Hudson, W. R.

    1977-01-01

    A microscopic surface texture was created by sputter-etching a surface while simultaneously sputter-depositing a lower sputter yield material onto the surface. A xenon ion-beam source was used to perform the texturing process on samples as large as 3-cm diameter. Textured surfaces have been characterized with SEM photomicrographs for a large number of materials including Cu, Al, Si, Ti, Ni, Fe, stainless steel, Au, and Ag. A number of texturing parameters are studied including the variation of texture with ion-beam powder, surface temperature, and the rate of texture growth with sputter etching time.

  5. Magnetic ions in crystals

    CERN Document Server

    Stevens, K W

    2014-01-01

    There have been many demonstrations, particularly for magnetic impurity ions in crystals, that spin-Hamiltonians are able to account for a wide range of experimental results in terms of much smaller numbers of parameters. Yet they were originally derived from crystal field theory, which contains a logical flaw; electrons on the magnetic ions are distinguished from those on the ligands. Thus there is a challenge: to replace crystal field theory with one of equal or greater predictive power that is based on a surer footing. The theory developed in this book begins with a generic Hamiltonian, on

  6. [Relativistic heavy ion research

    International Nuclear Information System (INIS)

    1990-01-01

    At Brookhaven National Laboratory, participation in the E802 Experiment, which is the first major heavy-ion experiment at the BNL-AGS, was the main focus of the group during the past four years. The emphases of the E802 experiment were on (a) accurate particle identification and measurements of spectra over a wide kinematical domain (5 degree LAB < 55 degree, p < 20 GeV/c); and (b) measurements of small-angle two-particle correlations, with event characterization tools: multiplicity array, forward and large-angle calorimeters. This experiment and other heavy ion collision experiments are discussed in this report

  7. Secondary ion emission

    International Nuclear Information System (INIS)

    Krohn, V.E.

    1976-01-01

    The Saha-Langmuir equation that describes the equilibrium emission process, surface ionization, has also been used to describe ion yields observed in the non-equilibrium emission process, sputtering. In describing sputtering, it is probably best to include the potential due to an image charge in the expression for negative as well as positive ion yield and to treat the work function and the temperature as parameters having limited physical significance. Arguments are presented to suggest that sputtered material is not emitted from a plasma. (Auth.)

  8. Heavy ion collisions

    International Nuclear Information System (INIS)

    Jacak, B.V.

    1994-01-01

    Heavy ion collisions at very high energies provide an opportunity to recreate in the laboratory the conditions which existed very early in the universe, just after the big bang. We prepare matter at very high energy density and search for evidence that the quarks and gluons are deconfined. I describe the kinds of observables that are experimentally accessible to characterize the system and to search for evidence of new physics. A wealth of information is now available from CERN and BNL heavy ion experiments. I discuss recent results on two particle correlations, strangeness production, and dilepton and direct photon distributions

  9. Ion-selective electrodes

    CERN Document Server

    Mikhelson, Konstantin N

    2013-01-01

    Ion-selective electrodes (ISEs) have a wide range of applications in clinical, environmental, food and pharmaceutical analysis as well as further uses in chemistry and life sciences. Based on his profound experience as a researcher in ISEs and a course instructor, the author summarizes current knowledge for advanced teaching and training purposes with a particular focus on ionophore-based ISEs. Coverage includes the basics of measuring with ISEs, essential membrane potential theory and a comprehensive overview of the various classes of ion-selective electrodes. The principles of constructing I

  10. Double chamber ion source

    International Nuclear Information System (INIS)

    Uman, M.F.; Winnard, J.R.; Winters, H.F.

    1978-01-01

    The ion source is comprised of two discharge chambers one of which is provided with a filament and an aperture leading into the other chamber which in turn has an extraction orifice. A low voltage arc discharge is operated in an inert gas atmosphere in the filament chamber while an arc of higher voltage is operated in the second ionization chamber which contains a vapor which will give the desired dopant ion species. The entire source is immersed in an axial magnetic field parallel to a line connecting the filament, the aperture between the two chambers and the extraction orifice. (author)

  11. Asymmetric ion trap

    Science.gov (United States)

    Barlow, Stephan E.; Alexander, Michael L.; Follansbee, James C.

    1997-01-01

    An ion trap having two end cap electrodes disposed asymmetrically about a center of a ring electrode. The inner surface of the end cap electrodes are conformed to an asymmetric pair of equipotential lines of the harmonic formed by the application of voltages to the electrodes. The asymmetry of the end cap electrodes allows ejection of charged species through the closer of the two electrodes which in turn allows for simultaneously detecting anions and cations expelled from the ion trap through the use of two detectors charged with opposite polarity.

  12. [Relativistic heavy ion research

    International Nuclear Information System (INIS)

    1991-01-01

    The present document describes our second-year application for a continuation grant on relativistic heavy-ion research at Nevis Laboratories, Columbia University, over the two-year period starting from November 15, 1990. The progress during the current budget year is presented. This year, construction of RHIC officially began. As a result, the entire Nevis nuclear physics group has made a coherent effort to create new proposal for an Open Axially Symmetric Ion Spectrometer (OASIS) proposal. Future perspectives and our plans for this proposal are described

  13. Small Column Ion Exchange

    International Nuclear Information System (INIS)

    Huff, Thomas

    2010-01-01

    Small Column Ion Exchange (SCIX) leverages a suite of technologies developed by DOE across the complex to achieve lifecycle savings. Technologies are applicable to multiple sites. Early testing supported multiple sites. Balance of SRS SCIX testing supports SRS deployment. A forma Systems Engineering Evaluation (SEE) was performed and selected Small Column Ion Exchange columns containing Crystalline Silicotitanate (CST) in a 2-column lead/lag configuration. SEE considered use of Spherical Resorcinol-Formaldehyde (sRF). Advantages of approach at SRS include: (1) no new buildings, (2) low volume of Cs waste in solid form compared to aqueous strip effluent; and availability of downstream processing facilities for immediate processing of spent resin.

  14. Electron capture in ion atom and ion-ion collisions

    International Nuclear Information System (INIS)

    Barat, M.

    1986-01-01

    Electron capture (EC) by positive ions in collision with various targets has remained one of the most important subjects of research since the early 30's. From a theoretical point of view, EC is obviously a coupled 3-body problem: at least two cores and an active electron that jumps between them. Practical interest in EC arose in a variety of fields. Recently a renewed interest arose from the physics of thermonuclear fusion, where capture by highly charged ionic impurities were found to be an important process in tokamak devices. For that reasons, a number of reviews were devoted to this subject during the past years, including lectures given in various NATO advanced science institutes. The aim of this lecture is not at all to add a new review to this list, but (i) to summarize the very basis of the present theoretical approaches at low and moderate collision energy, (ii) to pinpoint some crucial difficulties in the theoretical treatment, (iii) to select specific examples which, to the taste of the author, reflect some present practical interest, or some significant advances. 48 references, 38 figures, 1 table

  15. Ion-selective electrode reviews

    CERN Document Server

    Thomas, J D R

    1982-01-01

    Ion-Selective Electrode Reviews, Volume 3, provides a review of articles on ion-selective electrodes (ISEs). The volume begins with an article on methods based on titration procedures for surfactant analysis, which have been developed for discrete batch operation and for continuous AutoAnalyser use. Separate chapters deal with detection limits of ion-selective electrodes; the possibility of using inorganic ion-exchange materials as ion-sensors; and the effect of solvent on potentials of cells with ion-selective electrodes. Also included is a chapter on advances in calibration procedures, the d

  16. Cooling of molecular ion beams

    International Nuclear Information System (INIS)

    Wolf, A.; Krohn, S.; Kreckel, H.; Lammich, L.; Lange, M.; Strasser, D.; Grieser, M.; Schwalm, D.; Zajfman, D.

    2004-01-01

    An overview of the use of stored ion beams and phase space cooling (electron cooling) is given for the field of molecular physics. Emphasis is given to interactions between molecular ions and electrons studied in the electron cooler: dissociative recombination and, for internally excited molecular ions, electron-induced ro-vibrational cooling. Diagnostic methods for the transverse ion beam properties and for the internal excitation of the molecular ions are discussed, and results for phase space cooling and internal (vibrational) cooling are presented for hydrogen molecular ions

  17. Analytical applications of ion exchangers

    CERN Document Server

    Inczédy, J

    1966-01-01

    Analytical Applications of Ion Exchangers presents the laboratory use of ion-exchange resins. This book discusses the development in the analytical application of ion exchangers. Organized into 10 chapters, this book begins with an overview of the history and significance of ion exchangers for technical purposes. This text then describes the properties of ion exchangers, which are large molecular water-insoluble polyelectrolytes having a cross-linked structure that contains ionic groups. Other chapters consider the theories concerning the operation of ion-exchange resins and investigate th

  18. Development of focused ion beam systems with various ion species

    International Nuclear Information System (INIS)

    Ji Qing; Leung, K.-N.; King, Tsu-Jae; Jiang Ximan; Appleton, Bill R.

    2005-01-01

    Conventional focused ion beam systems employ a liquid-metal ion source (LMIS) to generate high-brightness beams, such as Ga + beams. Recently there has been an increased need for focused ion beams in areas like biological studies, advanced magnetic-film manufacturing and secondary-ion mass spectroscopy (SIMS). In this article, status of development on focused ion beam systems with ion species such as O 2 + , P + , and B + will be reviewed. Compact columns for forming focused ion beams from low energy (∼3keV), to intermediate energy (∼35keV) are discussed. By using focused ion beams, a SOI MOSFET is fabricated entirely without any masks or resist

  19. Energy landscapes for mobile ions in ion conducting solids

    Indian Academy of Sciences (India)

    molecular dynamics (MD) simulations yields quantitative predictions of the ion transport characteristics. As ... Solid electrolytes; bond valence analysis; ion transport in glasses. 1. .... clusters are considered to contribute only to a.c. conduc-.

  20. An RF ion source based primary ion gun for secondary ion mass spectroscopy

    International Nuclear Information System (INIS)

    Menon, Ranjini; Nabhiraj, P.Y.; Bhandari, R.K.

    2011-01-01

    In this article we present the design, development and characterization of an RF plasma based ion gun as a primary ion gun for SIMS application. RF ion sources, in particular Inductively Coupled Plasma (ICP) ion sources are superior compared to LMIS and duoplasmtron ion sources since they are filamentless, can produce ions of gaseous elements. At the same time, ICP ion sources offer high angular current density which is an important factor in producing high current in small spot size on the target. These high current microprobes improve the signal to noise ratio by three orders as compared to low current ion sources such as LMIS. In addition, the high current microprobes have higher surface and depth profiling speeds. In this article we describe a simple ion source in its very basic form, two lens optical column and characteristics of microprobe

  1. Polyatomic ions from a high current ion implanter driven by a liquid metal ion source

    Science.gov (United States)

    Pilz, W.; Laufer, P.; Tajmar, M.; Böttger, R.; Bischoff, L.

    2017-12-01

    High current liquid metal ion sources are well known and found their first application as field emission electric propulsion thrusters in space technology. The aim of this work is the adaption of such kind of sources in broad ion beam technology. Surface patterning based on self-organized nano-structures on, e.g., semiconductor materials formed by heavy mono- or polyatomic ion irradiation from liquid metal (alloy) ion sources (LMAISs) is a very promising technique. LMAISs are nearly the only type of sources delivering polyatomic ions from about half of the periodic table elements. To overcome the lack of only very small treated areas by applying a focused ion beam equipped with such sources, the technology taken from space propulsion systems was transferred into a large single-end ion implanter. The main component is an ion beam injector based on high current LMAISs combined with suited ion optics allocating ion currents in the μA range in a nearly parallel beam of a few mm in diameter. Different types of LMAIS (needle, porous emitter, and capillary) are presented and characterized. The ion beam injector design is specified as well as the implementation of this module into a 200 kV high current ion implanter operating at the HZDR Ion Beam Center. Finally, the obtained results of large area surface modification of Ge using polyatomic Bi2+ ions at room temperature from a GaBi capillary LMAIS will be presented and discussed.

  2. Heavy ion transfer reactions

    International Nuclear Information System (INIS)

    Weisser, D.C.

    1977-06-01

    To complement discussions on the role of γ rays in heavy ion induced reactions, the author discusses the role played by particle detection. Transfer reactions are part of this subject and are among those in which one infers the properties of the residual nucleus in a reaction by observing the emerging light nucleus. Inelastic scattering ought not be excluded from this subject, although no particles are transferred, because of the role it plays in multistep reactions and in fixing O.M. parameters describing the entrance channel of the reaction. Heavy ion transfer reaction studies have been under study for some years and yet this research is still in its infancy. The experimental techniques are difficult and the demands on theory rigorous. One of the main products of heavy ion research has been the thrust to re-examine the assumptions of reaction theory and now include many effects neglected for light ion analysis. This research has spurred the addition of multistep processes to simple direct processes and coupled channel calculations. (J.R.)

  3. Heavy ion accelerator GANIL

    International Nuclear Information System (INIS)

    1975-04-01

    This article presents GANIL, a large national heavy ion accelerator. The broad problems of nuclear physics, atomic physics, astrophysics and physics of condensed media which can be approached and studied with this machine are discussed first, after which the final construction project is described. The project comprises a circular injector, a separated sector cyclotron up beam stripper, and a second separated cyclotron downstream [fr

  4. Requirements for Ion Sources

    International Nuclear Information System (INIS)

    Scrivens, R

    2013-01-01

    Ion sources produce beams for a large variety of different physical experiments, industrial processes and medical applications. In order to characterize the beam delivered by them, a list of requirements is necessary. In this chapter the list of principal requirements is specified and definitions for them are given. (author)

  5. Heavy ion fusion

    International Nuclear Information System (INIS)

    Hofmann, Ingo

    1993-01-01

    With controlled thermonuclear fusion holding out the possibility of a prolific and clean new source of energy, the goal remains elusive after many years of continual effort. While the conventional Tokamak route with magnetic confinement continues to hit the headlines, other alternatives are now becoming competitive. One possible solution is to confine the thermonuclear fuel pellet by high power beams. Current research and perspectives for future work in such inertial confinement was the subject of the 'Prospects for Heavy Ion Fusion' European Research Conference held in Aghia Pelaghia, Crete, last year. Its main focus was on the potential of heavy ion accelerators as well as recent advances in target physics with high power lasers and light ion beams. Carlo Rubbia declared that high energy accelerators, with their high efficiency, are the most promising approach to economical fusion energy production. However the need for cost saving in the driver accelerator requires new ideas in target design tailored to the particularities of heavy ion beams, which need to be pushed to the limits of high current and phase space density at the same time

  6. Industrial ion source technology

    Science.gov (United States)

    Kaufman, H. R.; Robinson, R. S.

    1978-01-01

    An analytical model was developed to describe the development of a coned surface texture with ion bombardment and simultaneous deposition of an impurity. A mathematical model of sputter deposition rate from a beveled target was developed in conjuction with the texturing models to provide an important input to that model. The establishment of a general procedure that will allow the treatment of manay different sputtering configurations is outlined. Calculation of cross sections for energetic binary collisions was extened to Ar, Kr.. and Xe with total cross sections for viscosity and diffusion calculated for the interaction energy range from leV to 1000eV. Physical sputtering and reactive ion etching experiments provided experimental data on the operating limits of a broad beam ion source using CF4 as a working gas to produce reactive species in a sputtering beam. Magnetic clustering effects are observed when Al is seeded with Fe and sputtered with Ar(?) ions. Silicon was textured at a micron scale by using a substrate temperature of 600 C.

  7. Ion implantation into diamond

    International Nuclear Information System (INIS)

    Sato, Susumu

    1994-01-01

    The graphitization and the change to amorphous state of diamond surface layer by ion implantation and its characteristics are reported. In the diamond surface, into which more than 10 16 ions/cm 2 was implanted, the diamond crystals are broken, and the structure changes to other carbon structure such as amorphous state or graphite. Accompanying this change of structure, the electric conductivity of the implanted layer shows two discontinuous values due to high resistance and low resistance. This control of structure can be done by the temperature of the base during the ion implantation into diamond. Also it is referred to that by the base temperature during implantation, the mutual change of the structure between amorphous state and graphite can be controlled. The change of the electric resistance and the optical characteristics by the ion implantation into diamond surface, the structural analysis by Raman spectroscopy, and the control of the structure of the implanted layer by the base temperature during implantation are reported. (K.I.)

  8. Application of ion exchangers

    International Nuclear Information System (INIS)

    Markhol, M.

    1985-01-01

    Existing methods of multi-element separation for radiochemical analysis are considered. The majority of existing methods is noted to be based on application of organic and inorganic ion exchangers. Distillation, coprecipitation, extraction as well as combination of the above methods are also used. Concrete flowsheets of multi-element separation are presented

  9. Heavy-ion microscopy

    International Nuclear Information System (INIS)

    Kraft, G.; Yang, T.C.H.; Richards, T.; Tobias, C.A.

    1980-01-01

    This chapter briefly describes the techniques of optical microscopy, scanning and transmission electron microscopy, soft x-ray microscopy and compares these latter techniques with heavy-ion microscopy. The resolution obtained with these various types of microscopy are compared and the influence of the etching procedure on total resolution is discussed. Several micrographs of mammalian cells are included

  10. Field ion microscopy

    International Nuclear Information System (INIS)

    Ramanathan, D.

    1975-01-01

    The basic features of the Field-Ion Microscope (FIM) and the theory of image formation are explained. Design parameters of the FIM, factors limiting its resolution, interpretation of the image, etc are briefly outlined. Relative merits of the various imaging gases and the applications of the FIM are also covered. (K.B.)

  11. Relativisitic heavy ion collisions

    International Nuclear Information System (INIS)

    Tannenbaum, M.J.

    1987-01-01

    Some of the objectives and observables of Relativistic Heavy Ion Physics are presented. The first experimental results from oxygen interactions at CERN, 200 GeV/c per nucleon, and BNL, 14.5 GeV/c per nucleon are shown. The data indicate more energy emission than was originally predicted. 25 refs., 19 figs

  12. Ion-Beam-Excited Electrostatic Ion Cyclotron Waves

    DEFF Research Database (Denmark)

    Michelsen, Poul; Pécseli, Hans; Juul Rasmussen, Jens

    1976-01-01

    Self-excited electrostatic ion cyclotron waves were observed in an ion-beam-plasma system produced in a DP-operated Q-machine. The frequency of the waves showed the theoretically predicted variation with the magnetic field.......Self-excited electrostatic ion cyclotron waves were observed in an ion-beam-plasma system produced in a DP-operated Q-machine. The frequency of the waves showed the theoretically predicted variation with the magnetic field....

  13. Compact RF ion source for industrial electrostatic ion accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Hyeok-Jung, E-mail: hjkwon@kaeri.re.kr; Park, Sae-Hoon; Kim, Dae-Il; Cho, Yong-Sub [Korea Multi-purpose Accelerator Complex, Korea Atomic Energy Research Institute, Gyeongsangbukdo 38180 (Korea, Republic of)

    2016-02-15

    Korea Multi-purpose Accelerator Complex is developing a single-ended electrostatic ion accelerator to irradiate gaseous ions, such as hydrogen and nitrogen, on materials for industrial applications. ELV type high voltage power supply has been selected. Because of the limited space, electrical power, and robust operation, a 200 MHz RF ion source has been developed. In this paper, the accelerator system, test stand of the ion source, and its test results are described.

  14. Compact RF ion source for industrial electrostatic ion accelerator

    Science.gov (United States)

    Kwon, Hyeok-Jung; Park, Sae-Hoon; Kim, Dae-Il; Cho, Yong-Sub

    2016-02-01

    Korea Multi-purpose Accelerator Complex is developing a single-ended electrostatic ion accelerator to irradiate gaseous ions, such as hydrogen and nitrogen, on materials for industrial applications. ELV type high voltage power supply has been selected. Because of the limited space, electrical power, and robust operation, a 200 MHz RF ion source has been developed. In this paper, the accelerator system, test stand of the ion source, and its test results are described.

  15. Negative ion sources for tandem accelerator

    International Nuclear Information System (INIS)

    Minehara, Eisuke

    1980-08-01

    Four kinds of negative ion sources (direct extraction Duoplasmatron ion source, radial extraction Penniing ion source, lithium charge exchange ion source and Middleton-type sputter ion source) have been installed in the JAERI tandem accelerator. The ion sources can generate many negative ions ranging from Hydrogen to Uranium with the exception of Ne, Ar, Kr, Xe and Rn. Discussions presented in this report include mechanisms of negative ion formation, electron affinity and stability of negative ions, performance of the ion sources and materials used for negative ion production. Finally, the author will discuss difficult problems to be overcome in order to get any negative ion sufficiently. (author)

  16. Heavy-ion radiography and heavy-ion computed tomography

    International Nuclear Information System (INIS)

    Fabrikant, J.I.; Holley, W.R.; McFarland, E.W.; Tobias, C.a.

    1982-02-01

    Heavy-ion projection and CT radiography is being developed into a safe, low-dose, noninvasive radiological procedure that can quantitate and image small density differences in human tissues. The applications to heavy-ion mammography and heavy-ion CT imaging of the brain in clinical patients suggest their potential value in cancer diagnosis

  17. Using Ion Exchange Chromatography to Separate and Quantify Complex Ions

    Science.gov (United States)

    Johnson, Brian J.

    2014-01-01

    Ion exchange chromatography is an important technique in the separation of charged species, particularly in biological, inorganic, and environmental samples. In this experiment, students are supplied with a mixture of two substitution-inert complex ions. They separate the complexes by ion exchange chromatography using a "flash"…

  18. Recharging of a screened ion on the molecular ion

    International Nuclear Information System (INIS)

    Karbovanets, M.I.; Lazur, V.Yu.; Yudin, G.L.; Gosudarstvennyj Komitet po Ispol'zovaniyu Atomnoj Ehnergii SSSR, Obninsk. Fiziko-Ehnergeticheskij Inst.)

    1987-01-01

    Charge exchange of a screened ion on a molecular ion is studied in the Oppenheimer-Brinkman-Cramers approximation. To calculate ion exchange probabilities and cross sections summed over the final degenerated electron states method of Green functions analogous to that applied earlier in the direct Coulomb excitation theory and atomic ionization is developed

  19. Cs+ ion source for secondary ion mass spectrometry

    International Nuclear Information System (INIS)

    Bentz, B.L.; Weiss, H.; Liebl, H.

    1981-12-01

    Various types of cesium ionization sources currently used in secondary ion mass spectrometry are briefly reviewed, followed by a description of the design and performance of a novel, thermal surface ionization Cs + source developed in this laboratory. The source was evaluated for secondary ion mass spectrometry applications using the COALA ion microprobe mass analyzer. (orig.)

  20. ECR ion source based low energy ion beam facility

    Indian Academy of Sciences (India)

    Mass analyzed highly charged ion beams of energy ranging from a few keV to a few MeV plays an important role in various aspects of research in modern physics. In this paper a unique low energy ion beam facility (LEIBF) set up at Nuclear Science Centre (NSC) for providing low and medium energy multiply charged ion ...

  1. Hidden ion population: Revisited

    International Nuclear Information System (INIS)

    Olsen, R.C.; Chappell, C.R.; Gallagher, D.L.; Green, J.L.; Gurnett, D.A.

    1985-01-01

    Satellite potentials in the outer plasmasphere range from near zero to +5 to +10 V. Under such conditions ion measurements may not include the low energy core of the plasma population. In eclipse, the photoelectron current drops to zero, and the spacecraft potential can drop to near zero volts. In regions where the ambient plasma density is below 100 cm -3 , previously unobserved portions of the ambient plasma distribution function can become visible in eclipse. A survey of the data obtained from the retarding ion mass spectrometer (RIMS) on Dynamics Explorer 1 shows that the RIMS detector generally measured the isotropic background in both sunlight and eclipse in the plasma-sphere. Absolute density measurements for the ''hidden'' ion population are obtained for the first time using the plasma wave instrument observations of the upper hybrid resonance. Agreement in total density is found in sunlight and eclipse measurements at densities above 80 cm -3 . In eclipse, agreement is found at densities as low as 20 cm -3 . The isotropic plasma composition is primarily H + , with approx.10% He + , and 0.1 to 1.0% O + . A low energy field-aligned ion population appears in eclipse measurements outside the plasmasphere, which is obscured in sunlight. These field-aligned ions can be interpreted as field-aligned flows with densities of a few particles per cubic centimeter, flowing at 5-20 km/s. The problem in measuring these field-aligned flows in sunlight is the masking of the high energy tail of the field-aligned distribution by the isotropic background. Effective measurement of the core of the magnetospheric plasma distribution awaits satellites with active means of controlling the satellite potential

  2. Ion beam analysis

    International Nuclear Information System (INIS)

    Bethge, K.

    1995-01-01

    Full text: Ion beam analysis is an accelerator application area for the study of materials and the structure of matter; electrostatic accelerators of the Van de Graaff or Dynamitron type are often used for energies up to a few MeV. Two types of machines are available - the single-ended accelerator type with higher beam currents and greater flexibility of beam management, or the tandem accelerator, limited to atomic species with negative ions. The accelerators are not generally installed at specialist accelerator laboratories and have to be easy to maintain and simple to operate. The most common technique for industrial research is Rutherford Back Scattering Spectrometry (RBS). Helium ions are the preferred projectiles, since at elevated energies (above 3 MeV) nuclear resonance scattering can be used to detect photons associated with target molecules containing elements such as carbon, nitrogen or oxygen. Due to the large amount of available data on nuclear reactions in this energy range, activation analysis (detecting trace elements by irradiating the sample) can be performed with charged particles from accelerators over a wider range of atoms than with the conventional use of neutrons, which is more suited to light elements. Resonance reactions have been used to detect trace metals such as aluminium, titanium and vanadium. Hydrogen atoms are vital to the material performance of several classes of materials, such as semiconductors, insulators and ceramics. Prudent selection of the projectile ion aids the analysis of hydrogen composition; the technique is then a simple measurement of the emitted gamma radiation. Solar cell material and glass can be analysed in this way. On a world-wide basis, numerous laboratories perform ion beam analysis for research purposes; considerable work is carried out in cooperation between scientific laboratories and industry, but only a few laboratories provide a completely commercial service

  3. Design and simulation of ion optics for ion sources for production of singly charged ions

    Science.gov (United States)

    Zelenak, A.; Bogomolov, S. L.

    2004-05-01

    During the last 2 years different types of the singly charged ion sources were developed for FLNR (JINR) new projects such as Dubna radioactive ion beams, (Phase I and Phase II), the production of the tritium ion beam and the MASHA mass separator. The ion optics simulations for 2.45 GHz electron cyclotron resonance source, rf source, and the plasma ion source were performed. In this article the design and simulation results of the optics of new ion sources are presented. The results of simulation are compared with measurements obtained during the experiments.

  4. Design and simulation of ion optics for ion sources for production of singly charged ions

    International Nuclear Information System (INIS)

    Zelenak, A.; Bogomolov, S.L.

    2004-01-01

    During the last 2 years different types of the singly charged ion sources were developed for FLNR (JINR) new projects such as Dubna radioactive ion beams, (Phase I and Phase II), the production of the tritium ion beam and the MASHA mass separator. The ion optics simulations for 2.45 GHz electron cyclotron resonance source, rf source, and the plasma ion source were performed. In this article the design and simulation results of the optics of new ion sources are presented. The results of simulation are compared with measurements obtained during the experiments

  5. Prolonging coherence in trapped ions

    CSIR Research Space (South Africa)

    Uys, H

    2010-09-01

    Full Text Available The authors study pulse sequences that dynamically decouple 9Be+ ions from their decohering environment. The noise environment the ions see is artificially synthesized to emulate a variety of physical systems. By incorporating measurement feedback...

  6. Desempenho e características de carcaça de cordeiros alimentados com dietas contendo alta proporção de concentrado adicionadas de agentes tamponantes Performance and carcass characteristics of feedlot lambs fed high grain diets with buffer compounds

    Directory of Open Access Journals (Sweden)

    Adilson Luis Gastaldello Junior

    2010-03-01

    Full Text Available Objetivou-se com este estudo avaliar os efeitos da adição de bicarbonato de sódio ou de fontes de calcário com diferentes granulometrias na ração, associadas ou não a monensina sódica, sobre o desempenho e as características de carcaça de cordeiros confinados recebendo dietas contendo alta proporção de concentrado. Quarenta e dois cordeiros Santa Inês com peso inicial de 21 ± 3 kg e 88 ± 5 dias de idade foram distribuídos em blocos completos casualizados em arranjo fatorial 2 × 3, com seis tratamentos e sete repetições. Os animais foram alimentados com rações contendo 90% de concentrado, 10% de feno de "coastcross", uma fonte de calcário (calcário calcítico ou calcário calcítico tipo filler ou bicarbonato de sódio (NaHCO3, com ou sem adição de monensina sódica (30 mg/kg da MS. Não foi observada influência dos agentes tamponantes no consumo de matéria seca e no ganho de peso médio diário. Entretanto, a conversão alimentar dos animais alimentados com as rações contendo monensina sódica (3,32 kg MS/kg de ganho foi melhor que naqueles que consumiram as rações sem esse aditivo (3,58 kg MS/kg de ganho. Não houve efeito dos agentes tamponantes nos parâmetros de carcaça avaliados, observando-se valores médios de 50,4%; 2,4%; 13,9 cm² e 1,9 mm para o rendimento de carcaça quente, a perda por resfriamento, a área de olho-de-lombo e a espessura de gordura, respectivamente. A adição de monensina melhora a conversão alimentar e pode aumentar a rentabilidade do sistema de produção de cordeiros confinados.The objective of this study was to assess the effects of adding sodium bicarbonate or limestone sources with different particle sizes to the diet, and their interaction with sodium monensin, on the performance and carcass characteristics of feedlot lambs fed fed high grain diets. Forty two Santa Ines lambs were used with 21 ± 3 kg initial average body weight and 88 ± 5 days old in feedlot, placed a

  7. Atividade microbiana cecal e contribuição nutricional da cecotrofia em coelhos alimentados com rações contendo diferentes fontes de fibra e níveis de amido Caecal microbial activity and caecotrophy nutritional contribution in rabbits fed diets with different starch levels and fiber sources

    Directory of Open Access Journals (Sweden)

    Alex Martins Varela de Arruda

    2003-08-01

    Full Text Available Objetivou-se neste estudo a avaliação da atividade microbiana cecal e a contribuição nutricional da cecotrofia em coelhos alimentados com rações contendo diferentes níveis de amido (22 a 32% em média mediante a inclusão de milho grão e diferentes fontes de fibra (feno de alfafa ou casca de soja, em esquema fatorial 2x2. No primeiro experimento, 40 coelhos alojados em gaiolas de engorda individuais, em delineamento inteiramente casualizado e alimentados à vontade dos 45 aos 85 dias de idade, foram abatidos para coleta dos conteúdos ileais e cecais. A concentração de ácidos graxos voláteis foi influenciada pela interação entre tratamentos, sendo 93,82 mmol/l para ração de maior nível de amido com casca de soja e 80,03 mmol/l para ração de menor nível de amido com feno de alfafa. No segundo experimento, 40 coelhos aos 65 dias de idade, alojados em gaiolas de engorda individuais, em delineamento inteiramente casualizado, foram alimentados à vontade por 10 dias, e receberam colares de madeira para permitir a coleta total de cecotrofos. Houve influência da interação entre tratamentos sobre os teores de proteína e energia dos cecotrofos, sendo de 29,66% e 4204,87 kcal/kg para ração contendo maiores níveis de amido e casca de soja e de 27,98% e 4080,46 kcal/kg para ração contendo menores níveis de amido e feno de alfafa. As rações de alto amido ou com casca de soja propiciaram maior enriquecimento do conteúdo cecal e melhor aporte nutricional para os coelhos.The objective of this study was to evaluate the caecal microbial activity and caecotrophy nutritional contribution in rabbits fed diets with differents starch levels (22 or 32% on average from a high or low inclusion of corn grain and differents fiber sources (alfalfa hay or soybean hulls, in a 2x2 factorial design. In the first experiment, 40 rabbits were individually housed in fattening cages within entirely randomized design, and fed ad libitum from 45 to 85

  8. Low-altitude ion heating with downflowing and upflowing ions

    Science.gov (United States)

    Shen, Y.; Knudsen, D. J.; Burchill, J. K.; Howarth, A. D.; Yau, A. W.; James, G.; Miles, D.; Cogger, L. L.; Perry, G. W.

    2017-12-01

    Mechanisms that energize ions at the initial stage of ion upflow are still not well understood. We statistically investigate ionospheric ion energization and field-aligned motion at very low altitudes (330-730 km) using simultaneous plasma, magnetic field, wave electric field and optical data from the e-POP satellite. The high-time-resolution (10 ms) dataset enables us to study the micro-structures of ion heating and field-aligned ion motion. The ion temperature and field-aligned bulk flow velocity are derived from 2-D ion distribution functions measured by the SEI instrument. From March 2015 to March 2016, we've found 17 orbits (in total 24 ion heating periods) with clear ion heating signatures passing across the dayside cleft or the nightside auroral regions. Most of these events have consistent ion heating and flow velocity characteristics observed from both the SEI and IRM instruments. The perpendicular ion temperature goes up to 4.5 eV within a 2 km-wide region in some cases, in which the Radio Receiver Instrument (RRI) sees broadband extremely low frequency (BBELF) waves, demonstrating significant wave-ion heating down to as low as 350 km. The e-POP Fast Auroral Imager (FAI) and Magnetic Field (MGF) instruments show that many events are associated with active aurora and are within downward current regions. Contrary to what would be expected from mirror-force acceleration of heated ions, the majority of these heating events (17 out of 24) are associated with the core ion downflow rather than upflow. These statistical results provide us with new sights into ion heating and field-aligned flow processes at very low altitudes.

  9. Metal ion transporters and homeostasis.

    OpenAIRE

    Nelson, N

    1999-01-01

    Transition metals are essential for many metabolic processes and their homeostasis is crucial for life. Aberrations in the cellular metal ion concentrations may lead to cell death and severe diseases. Metal ion transporters play a major role in maintaining the correct concentrations of the various metal ions in the different cellular compartments. Recent studies of yeast mutants revealed key elements in metal ion homeostasis, including novel transport systems. Several of the proteins discover...

  10. Ion sources for industrial use

    International Nuclear Information System (INIS)

    Sakudo, Noriyuki

    1994-01-01

    Industrial applications of ion beams began in the 1970's with their application in fabrication of semiconductor devices. Since then, various improvements have been carried out for source lifetimes, current levels and diversification of ion species. Nowadays, ion beams are expected to be used for surface modification of materials as well as semiconductor fabrication. In this report, some of the typical ion sources are reviewed from the viewpoint of future industrial use. (author)

  11. Membranes in Lithium Ion Batteries

    Science.gov (United States)

    Yang, Min; Hou, Junbo

    2012-01-01

    Lithium ion batteries have proven themselves the main choice of power sources for portable electronics. Besides consumer electronics, lithium ion batteries are also growing in popularity for military, electric vehicle, and aerospace applications. The present review attempts to summarize the knowledge about some selected membranes in lithium ion batteries. Based on the type of electrolyte used, literature concerning ceramic-glass and polymer solid ion conductors, microporous filter type separators and polymer gel based membranes is reviewed. PMID:24958286

  12. Membranes in Lithium Ion Batteries

    Directory of Open Access Journals (Sweden)

    Junbo Hou

    2012-07-01

    Full Text Available Lithium ion batteries have proven themselves the main choice of power sources for portable electronics. Besides consumer electronics, lithium ion batteries are also growing in popularity for military, electric vehicle, and aerospace applications. The present review attempts to summarize the knowledge about some selected membranes in lithium ion batteries. Based on the type of electrolyte used, literature concerning ceramic-glass and polymer solid ion conductors, microporous filter type separators and polymer gel based membranes is reviewed.

  13. Numerical simulation of ion temperature gradient driven modes in the presence of ion-ion collisions

    International Nuclear Information System (INIS)

    Xu, X.Q.

    1990-08-01

    Ion temperature gradient driven modes in the presence of ion-ion collisions in a toroidal geometry with trapped ions have been studied by using a 1 2/2 d linearized gyro-kinetic particle simulation code in the electrostatic limit. The purpose of the investigation is to try to understand the physics of flat density discharges, in order to test the marginal stability hypothesis. Results giving threshold conditions of L Ti /R 0 , an upper bound on k χ , and linear growth rates and mode frequencies over all wavelengths for the collisionless ion temperature gradient driven modes are obtained. The behavior of ion temperature gradient driven instabilities in the transition from slab to toroidal geometry, with trapped ions, is shown. A Monte Carlo scheme for the inclusion of ion-ion collisions, in which ions can undergo Coulomb collisional dynamical friction, velocity space diffusion and random walk of guiding centers, has been constructed. The effects of ion-ion collisions on the long wave length limit of the ion modes is discussed. 44 refs., 12 figs

  14. Ion temperature via laser scattering on ion Bernstein waves

    International Nuclear Information System (INIS)

    Wurden, G.A.; Ono, M.; Wong, K.L.

    1981-10-01

    Hydrogen ion temperature has been measured in a warm toroidal plasma with externally launched ion Bernstein waves detected by heterodyne CO 2 laser scattering. Radial scanning of the laser beam allows precise determination of k/sub perpendicular to/ for the finite ion Larmor radius wave (ω approx. less than or equal to 2Ω/sub i/). Knowledge of the magnetic field strength and ion concentration then give a radially resolved ion temperature from the dispersion relation. Probe measurements and Doppler broadening of ArII 4806A give excellent agreement

  15. Photochemical reactions of actinide ions

    International Nuclear Information System (INIS)

    Tomiyasu, Hiroshi

    1995-01-01

    This paper reviews the results of photochemical studies of actinide ions, which have been performed in our research group for past several years as follows: I) behavior of the excited uranyl(VI) ion; II) photo-reductions of the uranyl ion with organic and inorganic compounds; III) photo-oxidations of uranium(IV) and plutonium(III) in nitric acid solutions. (author)

  16. Digestibilidade e tempo de trânsito gastrintestinal de dietas contendo níveis crescentes de fibra bruta para pacu - doi: 10.4025/actascianimsci.v32i2.8625 Digestibility and gastrointestinal transit time of diets with increasing dietary fiber levels to pacu - doi: 10.4025/actascianimsci.v32i2.8625

    Directory of Open Access Journals (Sweden)

    Thiago Matias Torres Nascimento

    2010-07-01

    Full Text Available O objetivo deste trabalho foi avaliar a digestibilidade e o tempo de trânsito gastrintestinal (TTGI de dietas contendo níveis crescentes de fibra bruta (FB para pacus. Para avaliar a digestibilidade foram utilizados 288 pacus, em delineamento inteiramente casualizado, alimentados em aquários e transferidos para coletores do tipo Guelf Modificado, utilizando-se o método de coleta parcial de fezes. As rações foram marcadas com 1% de óxido de crômio para a determinação da digestibilidade das dietas. No ensaio de TTGI, 288 pacus foram distribuídos em 24 aquários em delineamento inteiramente casualizado e alimentados com rações contendo 1% óxido de titânio ou crômio, que apresentam cores diferentes, verde ou branca, respectivamente. Por meio de massagem abdominal foi averiguada periodicamente a cor das fezes, e o TTGI foi estabelecido quando as fezes de todos os peixes apresentaram cor verde. Os coeficientes de digestibilidade aparente das dietas e o TTGI foram reduzidos com aumento do nível de FB nas dietas. Conclui-se que em dietas para pacus pode-se empregar até 9% de FB sem efeito negativo na digestibilidade da energia, proteína, matéria seca e estrato etéreo e sem alterar o TTGI.This work aimed to evaluate the effect of increasing dietary fiber levels on the digestibility and gastrointestinal transit time (GTT for pacu. The digestibility trial used 288 pacu in a completely randomized design, fed in aquaria and transferred to a modified Guelf-type feces collector, using the partial sampling method. The inert marker on the diets was chromic oxide (1% to establish the diet digestibility. In the GTT assay, 288 pacu were distributed in 24 aquaria in a completely randomized design. Fish were fed with two colored diets – green and white – and feces color was determined after abdominal pressure. The white and green diets used 1% of titanium and chromic oxides, respectively. Total GTT was determined when all fish showed green

  17. Efeito de gomas de mascar contendo clorofenol / peróxido de hidrogênio, xilitol ou clorexidina no fluxo salivar, pH, capacidade tampão e escores salivares de Streptococcus mutans = Effects of chlorophenol / hydrogen peroxide versus xylitol or chlorhexidine as chewing gum on salivary flow rate, pH, buffer capacity and salivary Streptococcus mutans scores

    Directory of Open Access Journals (Sweden)

    Yévenes López, Ismael

    2014-01-01

    Full Text Available Objetivos: Gomas de mascar medicadas são preparações sólidas, de dose única, que devem ser mastigadas por um determinado período de tempo a fim de que um ou mais agentes farmacológicos sejam admnistrados. Neste contexto, gomas de mascar medicadas com três ingredientes farmacêuticos ativos – cânfora, p-clorofenol e peróxido de hidrogênio – foram avaliadas como agentes terapêuticos para cárie dentária. O objetivo deste estúdio foi comparar o efeito de gomas de mascar contendo chlorophenol / peróxido de hidrogênio, xilitol ou clorexidina sobre Streptococos mutans salivares, pH, capacidade tampão, a taxa de secreção salivar. Métodos: Foi realizado estudo duplo-cego, com deliamento de randomização cruzada de tratamento em 24 pacientes. Esses foram submetidos a seis sequências diferentes de tratamento. Gomas de mascar foram administradas três vezes ao dia durante 20 minutos, pela manhã, tarde e noite. No início e no final das três fases de amostras de saliva experimentais foram obtidas para a determinação de pH, capacidade tampão, fluxo salivar e enumeração quantitativa de S. mutans. Resultados: O uso de goma medicado de cânfora com p-clorofenol e peróxido de hidrogénio não modificaram os parâmetros químicos salivares medidos, e reduziram o número de S. mutans, após 7 dias. Gomas de mascar contendo clorexidina reduziram significativamente a contagem quantitativa de S. mutans e a taxa de fluxo salivar em um período de 7 dias. Conclusões: O uso de gomas de mascar medicadas com base de cânfora / p-clorofenol ou com peróxido de hidrogênio não altera significativamente os parâmetros químicos salivares e não reduz significativamente o número de S. mutans após a utilização por período de 7 dias

  18. Antiplaque and antigingivitis effects of a gel containing Punica granatum Linn extract: a double-blind clinical study in humans Efeito antiplaca e antiinflamatório de um gel contendo extrato de romã: estudo clínico duplo-cego em humanos

    Directory of Open Access Journals (Sweden)

    Alexandre Daher Yunes Salgado

    2006-06-01

    Full Text Available OBJECTIVES: The antiplaque and antigingivitis effects of a gel containing 10% Punica granatum Linn extract were evaluated using a 21-day partial-mouth experimental model of gingivitis. METHODS: 23 volunteers participated in this cross-over, double-blind study, carried out in 2 phases of 21 days each. For each period of the experiment, an acrylic toothshield was made for each volunteer to carry the test or placebo gel as well as to avoid brushing of the 4 experimental teeth (posterior teeth in the lower left quadrant. The subjects were randomly assigned to use either the placebo gel (control group or the test gel (experimental group and were instructed to brush the remaining teeth normally 3 times a day. On days 0 and 21, the visible plaque index (VPI and gingival bleeding index (GBI were recorded. RESULTS: The results did not show statistically significant difference between control and experimental groups for either of the indices (VPI and GBI. CONCLUSION: The gel containing 10% Punica granatum Linn extract was not efficient in preventing supragingival dental plaque formation and gingivitis.OBJETIVOS: O efeito antiplaca e antigengivite de um gel contendo extrato de romã a 10% foi avaliado utilizando um modelo de gengivite experimental parcial em humanos. MÉTODOS: 23 indivíduos participaram voluntariamente deste estudo cruzado, duplo-cego, compreendendo dois períodos de 21 dias cada um. Uma moldeira de acrílico foi confeccionada para cada participante, a qual foi utilizada como carreadora dos géis sobre a área a ser avaliada (hemiarco inferior esquerdo. Os sujeitos foram aleatoriamente designados para usar o gel placebo (grupo controle ou o gel teste (grupo experimental, sendo instruídos a colocar o gel na moldeira e esta sobre os dentes teste, escovando os outros normalmente três vezes ao dia. No dia 0 e dia 21 os índices de placa visível (IPV e índice de sangramento gengival (ISG foram registrados. RESULTADOS: Os resultados n

  19. Digestibilidade aparente da energia e da fibra de dietas para ovinos contendo uréia, amiréia ou farelo de algodão Apparent digestibility of energy and fiber of sheep diets containing urea, starea or cottonseed meal

    Directory of Open Access Journals (Sweden)

    Jane Maria Bertocco Ezequiel

    2001-02-01

    Full Text Available Este trabalho foi conduzido com o objetivo de avaliar a digestibilidade da energia e da fibra de dietas contendo uréia, amiréia ou farelo de algodão como fontes protéicas exclusivas e silagem de milho como volumoso. Utilizaram-se 24 borregos com 11 meses de idade e peso médio 31 kg e o método da coleta total de fezes. A ingestão de matéria seca foi de 64,1; 68,8 e 71,4 g/kg PV0,75/dia e as digestibilidades da energia da FDN e da FB foram 63,0; 67,7 e 64,4%, 39,6; 55,7 e 50,0%, 47,0; 49,3 e 53,4%, respectivamente, para dietas com uréia, amiréia e farelo de algodão. Os ganhos em peso foram 278,5; 348,0; e 293,7 g/anim.dia, na mesma ordem. O uso da amiréia poderá ser o mais adequado, em relação a uréia e farelo de algodão, em dietas para borregos contendo silagem de milho como volumoso.This research was conducted to evaluate the energy and the fiber digestibility of diets containing urea, starea and cottonseed meal as nitrogen sources and corn silage as forage. Twenty-four lambs averaging 11 months old and initial 31 kg LW and total feces collection method were used. Dry matter intake was 64.1, 68.8 and 71.4 g /kg PV.75 /day and the energy, NDF and CF digestibilities were 63.0, 67.7 and 64.4%, 39.6, 55.7 and 50.0%, 47.0, 49.3 and 53.4%, for the diets with urea, starea and cottonseed meal, respectively. The average weights gain were 278.5, 348.0 and 293.7 g/anim./day, in the same above sequence. The use of starea would be more adequate in relation to urea and cottonseed meal in diets with corn silage as forage for lambs.

  20. Estudo Reológico de Tintas de Poliuretano Contendo PAni-DBSA Aplicadas como Materiais Absorvedores de Microondas (8-12 GHz Rheological Study of Paints Based on Polyurethane and PAni-DBSA and its Application as Microwave Absorbing Materials (8 - 12 GHz

    Directory of Open Access Journals (Sweden)

    Rogério S. Biscaro

    2002-10-01

    Full Text Available Neste trabalho preparou-se tintas condutoras baseadas em blendas de poliuretano contendo polianilina em diferentes proporções. Estudou-se as influências do método de dopagem da polianilina (PAni e do tempo de processamento da mistura no comportamento reológico da tinta. Verificou-se que a dopagem, com o ácido dodecilbenzeno sulfônico (DBSA, por processamento reativo (PAni-DBSA-pr afetou, de maneira mais acentuada, a viscosidade da tinta devido, principalmente, ao excesso de ácido dopante presente nessa amostra. Esse efeito foi observado pelas análises reológicas devido às alterações nos valores de viscosidade complexa, controlando-se o tempo de repouso das misturas. Medidas espectrofotométricas na região do infravermelho foram realizadas para verificar a ocorrência de interações entre os componentes da mistura (o poliuretano e a polianilina, constatando-se que, possivelmente, não ocorreram ligações químicas, mas somente interações físicas. Observou-se também que, amostras contendo 15% (m/m de PAni-DBSA-pr absorveram aproximadamente 48% da radiação eletromagnética incidente (8-12 GHz, indicando a viabilidade do uso desta tinta como material absorvedor de radiação.In this work, conducting paints based on blends of polyurethane and polyaniline in different proportions were prepared. The effects of both, polyaniline doping method and the blend processing time on the paint rheological behavior were evaluated. It was observed that the doping of the polyaniline with dodecylbenzene sulphonic acid (DBSA by reactive processing (PAni-DBSA-pr altered the paint complex viscosity due to the excess of the DBSA used in that doping process. This effect was observed during the rheological analyses by controlling the resting time of the prepared samples. FTIR analyses were carried out to verify possible interactions among the components of the mixture (polyurethane and polyaniline, suggesting that no chemical reactions occurred, but

  1. High current vacuum arc ion source for heavy ion fusion

    International Nuclear Information System (INIS)

    Qi, N.; Schein, J.; Gensler, S.; Prasad, R.R.; Krishnan, M.; Brown, I.

    1999-01-01

    Heavy Ion fusion (HIF) is one of the approaches for the controlled thermonuclear power production. A source of heavy ions with charge states 1+ to 2+, in ∼0.5 A current beams with ∼20 micros pulse widths and ∼10 Hz repetition rates are required. Thermionic sources have been the workhorse for the HIF program to date, but suffer from sloe turn-on, heating problems for large areas, are limited to low (contact) ionization potential elements and offer relatively low ion fluxes with a charge state limited to 1+. Gas injection sources suffer from partial ionization and deleterious neutral gas effects. The above shortcomings of the thermionic ion sources can be overcome by a vacuum arc ion source. The vacuum arc ion source is a good candidate for HIF applications. It is capable of providing ions of various elements and different charge states, in short and long pulse bursts, with low emittance and high beam currents. Under a Phase-I STTR from DOE, the feasibility of the vacuum arc ion source for the HIF applications is investigated. An existing ion source at LBNL was modified to produce ∼0.5 A, ∼60 keV Gd (A∼158) ion beams. The experimental effort concentrated on beam noise reduction, pulse-to-pulse reproducibility and achieving low beam emittance at 0.5 A ion current level. Details of the source development will be reported

  2. Production of highly charged ion beams from ECR ion sources

    International Nuclear Information System (INIS)

    Xie, Z.Q.

    1997-09-01

    Electron Cyclotron Resonance (ECR) ion source development has progressed with multiple-frequency plasma heating, higher mirror magnetic fields and better technique to provide extra cold electrons. Such techniques greatly enhance the production of highly charged ions from ECR ion sources. So far at cw mode operation, up to 300 eμA of O 7+ and 1.15 emA of O 6+ , more than 100 eμA of intermediate heavy ions for charge states up to Ar 13+ , Ca 13+ , Fe 13+ , Co 14+ and Kr 18+ , and tens of eμA of heavy ions with charge states to Kr 26+ , Xe 28+ , Au 35+ , Bi 34+ and U 34+ have been produced from ECR ion sources. At an intensity of at least 1 eμA, the maximum charge state available for the heavy ions are Xe 36+ , Au 46+ , Bi 47+ and U 48+ . An order of magnitude enhancement for fully stripped argon ions (I ≥ 60 enA) also has been achieved. This article will review the ECR ion source progress and discuss key requirement for ECR ion sources to produce the highly charged ion beams

  3. Scanning ion microscopy with low energy lithium ions

    International Nuclear Information System (INIS)

    Twedt, Kevin A.; Chen, Lei; McClelland, Jabez J.

    2014-01-01

    Using an ion source based on photoionization of laser-cooled lithium atoms, we have developed a scanning ion microscope with probe sizes of a few tens of nanometers and beam energies from 500 eV to 5 keV. These beam energies are much lower than the typical operating energies of the helium ion microscope or gallium focused ion beam systems. We demonstrate how low energy can be advantageous in ion microscopy when detecting backscattered ions, due to a decreased interaction volume and the potential for surface sensitive composition analysis. As an example application that demonstrates these advantages, we non-destructively image the removal of a thin residual resist layer during plasma etching in a nano-imprint lithography process. - Highlights: • We use an ion source based on photoionization of laser-cooled lithium atoms. • The ion source makes possible a low energy (500 eV to 5 keV) scanning ion microscope. • Low energy is preferred for ion microscopy with backscattered ions. • We use the microscope to image a thin resist used in nano-imprint lithography

  4. Production of highly ionized recoil ions in heavy ion impact

    International Nuclear Information System (INIS)

    Tawara, H.; Tonuma, T.; Be, S.H.; Shibata, H.; Kase, M.; Kambara, T.; Kumagai, H.; Kohno, I.

    1985-01-01

    The production mechanisms of highly ionized recoil ions in energetic, highly charged heavy ion impact are compared with those in photon and electron impact. In addition to the innershell ionization processes which are important in photon and electron impact, the electron transfer processes are found to play a key role in heavy ion impact. In molecular targets are also observed highly ionized monoatomic ions which are believed to be produced through production of highly ionized molecular ions followed by prompt dissociation. The observed N 6+ ions produced in 1.05MeV/amu Ar 12+ ions on N 2 molecules are produced through, for example, N 2 12+ *→N 6+ +N 6+ process. (author)

  5. Fusion at counterstreaming ion beams - ion optic fusion (IOF)

    International Nuclear Information System (INIS)

    Gryzinski, M.

    1981-01-01

    The results of investigation are briefly reviewed in the field of ion optic fusion performed at the Institute of Nuclear Research in Swierk. The ion optic fusion concept is based on the possibility of obtaining fusion energy at highly ordered motion of ions in counterstreaming ion beams. For this purpose TW ion beams must be produced and focused. To produce dense and charge-neutralized ion beams the selective conductivity and ballistic focusing ideas were formulated and used in a series of RPI devices with low-pressure cylindrical discharge between grid-type electrodes. 100 kA, 30 keV deuteron beams were successfully produced and focused into the volume of 1 cm 3 , yielding 10 9 neutrons per 200 ns shot on a heavy ice target. Cylindrically convergent ion beams with magnetic anti-defocusing were proposed in order to reach a positive energy gain at reasonable energy level. (J.U.)

  6. Ion microtomography using ion time-of-flight

    International Nuclear Information System (INIS)

    Roberts, M.L.; Heikkinen, D.W.; Proctor, I.D.; Pontau, A.E.; Olona, G.T.; Felter, T.E.; Morse, D.H.; Hess, B.V.

    1992-01-01

    We have developed and are in the process of testing an ion time-of-flight (TOF) detector system for use in our ion microtomography measurements. Using TOF, ion energy is determined by measurement of the ion's flight time over a certain path length. For ion microtomography, the principle advantage of TOF analysis is that ion count rates of several hundred thousand counts per second can be achieved as compared to a limit of about ten thousand ions per second when using a solid-state silicon surface barrier detector and associated electronics. This greater than 10 fold increase in count rate correspondingly shortens sample analysis time or increases the amount of data that can be collected on a given sample. Details of the system and progress to date are described

  7. A laser ablation ion source for the FRS ion catcher

    Energy Technology Data Exchange (ETDEWEB)

    Rink, Ann-Kathrin; Ebert, Jens; Petrick, Martin; Reiter, Pascal [Justus Liebig Universitaet Giessen (Germany); Dickel, Timo; Geissel, Hans; Plass, Wolfgang; Scheidenberger, Christoph [Justus Liebig Universitaet Giessen (Germany); GSI, Darmstadt (Germany); Purushothamen, Sivaji [GSI, Darmstadt (Germany)

    2013-07-01

    The FRS Ion Catcher was developed to serve as test bench for the low energy branch of the Super FRS to slow down exotic nuclei and prepare them for further measurements/ experiments. It consists of a cryogenic stopping cell to thermalise the ions, a diagnostic unit for stopping cell characterisation and various radiofrequency quadrupole structures to guide the ions to the Multiple-Reflection Time-of-Flight Mass Spectrometer for mass measurements, α spectroscopy and isobar separation. To characterise the extraction times of the stopping cell, which is one of the main performance parameters of such a cell, a laser ablation ion source has been develped and tested. This ion source provides a sharply defined starting point of the ions for the extraction time measurement. In the future this source will provide reference ions to calibrate the mass spectrometer for accurate mass measurements.

  8. Design study of primary ion provider for relativistic heavy ion collider electron beam ion source.

    Science.gov (United States)

    Kondo, K; Kanesue, T; Tamura, J; Okamura, M

    2010-02-01

    Brookhaven National Laboratory has developed the new preinjector system, electron beam ion source (EBIS) for relativistic heavy ion collider (RHIC) and National Aeronautics and Space Administration Space Radiation Laboratory. Design of primary ion provider is an essential problem since it is required to supply beams with different ion species to multiple users simultaneously. The laser ion source with a defocused laser can provide a low charge state and low emittance ion beam, and is a candidate for the primary ion source for RHIC-EBIS. We show a suitable design with appropriate drift length and solenoid, which helps to keep sufficient total charge number with longer pulse length. The whole design of primary ion source, as well as optics arrangement, solid targets configuration and heating about target, is presented.

  9. Características produtivas e imunológicas de frangos de corte submetidos a dietas suplementadas com cromo, criados sob diferentes condições de ambiente Productive and immunological traits of broiler chickens fed diets supplemented with chromium, reared under different environmental conditions

    Directory of Open Access Journals (Sweden)

    Alexandre Oba

    2012-05-01

    Full Text Available Objetivou-se avaliar o desempenho, a resposta imune e as características de carcaça de frangos de corte alimentados com dietas suplementadas com cromo complexado a levedura (Saccharomyces cerevisae, criados em diferentes condições de temperatura. O experimento foi conduzido em câmaras climáticas com sistema de aquecimento e refrigeração, utilizando-se as seguintes condições de temperatura, de acordo com as idades: 1 a 3 dias (35, 35 e 35 ºC ± 2, 4 a 7 dias (35, 30, 25 ºC ± 2, 8 a 14 dias (34, 27 e 20 ºC ± 2, 15 a 21 dias (33, 26 e 18 ºC ± 2 e de 22 a 47 dias (32, 26 e 18 ºC ± 2, respectivamente, para temperatura quente, termoneutra e fria. As dietas foram suplementadas com 0, 400, 800, 1.200 μg Cr/kg. A suplementação de 400 μg Cr/kg melhora a viabilidade e, em aves mantidas em temperatura quente, a conversão alimentar, enquanto a temperatura de criação mostrou ter grande influência sobre as características produtivas em todas as fases de criação. As aves criadas em temperatura quente apresentam melhor resposta imune, maior rendimento de carcaça e pernas e resultados inferiores de desempenho e rendimento de peito.The objective of this experiment was to evaluate performance, immune response and traits concerning carcass and poultry cuts of broiler chickens fed diets supplemented with chromium-yeast (Saccharomyces cerevisae, reared under different environmental temperature conditions. Birds were reared in climate chambers with heating and cooling system, using the following environmental temperatures according to ages: from 1 to 3 days of age (35, 35 and 35 ºC ± 2, from 4 to 7 days of age (35, 30 and 25 ºC ± 2, from 8 to 14 days old (34, 27 and 20 ºC ± 2, from 15 to 21 days of age (33, 26 and 18 ºC ± 2 and from 22 to 47 days of age (32, 26 and 18 ºC ± 2, respectively, for high, thermoneutral and low temperatures. Diets were supplemented with 0; 400; 800; and 1,200 μg Cr/kg. Supplementation with 400 μg Cr

  10. Cleanliness distribution of high-carbon chromium bearing steel billets and growth behavior of inclusions during solidification; Distribución y crecimiento de inclusiones en la solidificación de barras de acero para rodamientos con cromo y alto contenido de carbono

    Energy Technology Data Exchange (ETDEWEB)

    Gu, C.; Bao, Y.; Lin, L.

    2017-09-01

    Variation of cleanliness and distribution of inclusions in thickness and width direction of highcarbon chromium bearing steel billets has been studied using total oxygen and nitrogen analysis and SEM/EDS, and the growth behavior of inclusions during solidification was studied with the help of solidification model. The region wit h relatively high total oxygen contents in the cross profile of billets is between inner arc side 3/16 and outer arc side 1/4; between left edge side 5/16 and right edge side 5/16. The formation sequence of inclusions is MgO-Al2O3 > TiN > MnS. MnS could wrap MgO-Al2O3 and reduces the damage to steel matrix caused by the latter, but generally could not effectively wrap TiN. Besides, TiN could wrap MgO-Al2O3 before MnS, which would weaken the protective capacity of MnS. Moreover, compared with MgO-Al2O3 inclusions, the sizes of TiN inclusions are generally larger. Thus the control of TiN inclusions should be strengthened. In hickness direction, the maximum size regions of TiN and MnS inclusions are inner arc side 1/3 and outer arc side 1/3; in width direction, the regions are edge side 1/3. During bearing processing, these regions and the regions with high total oxygen content should be avoided. [Spanish] La distribución de inclusiones en las secciones transversales y longitudinales de barras de acero para rodamientos al cromo con alto contenido de carbono se ha estudiado determinando el contenido total de nitrógeno y oxígeno y mediante SEM/EDS. El crecimiento de inclusiones durante la solidificación se estudió con la ayuda del modelo de solidificación. La zona con contenido total de oxígeno relativamente alto en la sección transversal de las barras, es entre el arco interior de 3/16 y el exterior 1/4; entre el borde izquierdo 5/16 y el derecho 5/16. La secuencia de formación de las inclusiones es MgO-Al2O3 > TiN > MnS. El MnS podría envolver a los óxidos de magnesio y aluminio (MgO-Al2O3) y reducir el daño causado al acero, pero

  11. Experimental Evaluation of a Negative Ion Source for a Heavy Ion Fusion Negative Ion Driver

    International Nuclear Information System (INIS)

    Grisham, L.R.; Hahto, S.K.; Hahto, S.T.; Kwan, J.W.; Leung, K.N.

    2004-01-01

    Negative halogen ions have recently been proposed as a possible alternative to positive ions for heavy ion fusion drivers because electron accumulation would not be a problem in the accelerator, and if desired, the beams could be photo-detached to neutrals. To test the ability to make suitable quality beams, an experiment was conducted at Lawrence Berkeley National Laboratory using chlorine in an RF-driven ion source. Without introducing any cesium (which is required to enhance negative ion production in hydrogen ion sources) a negative chlorine current density of 45 mA/cm 2 was obtained under the same conditions that gave 57 45 mA/cm 2 of positive chlorine, suggesting the presence of nearly as many negative ions as positive ions in the plasma near the extraction plane. The negative ion spectrum was 99.5% atomic chlorine ions, with only 0.5% molecular chlorine, and essentially no impurities. Although this experiment did not incorporate the type of electron suppression technology that i s used in negative hydrogen beam extraction, the ratio of co-extracted electrons to Cl - was as low as 7 to 1, many times lower than the ratio of their mobilities, suggesting that few electrons are present in the near-extractor plasma. This, along with the near-equivalence of the positive and negative ion currents, suggests that the plasma in this region was mostly an ion-ion plasma. The negative chlorine current density was relatively insensitive to pressure, and scaled linearly with RF power. If this linear scaling continues to hold at higher RF powers, it should permit current densities of 100 45 mA/cm 2 , sufficient for present heavy ion fusion injector concepts. The effective ion temperatures of the positive and negative ions appeared to be similar and relatively low for a plasma source

  12. Trapped Ion Qubits

    Energy Technology Data Exchange (ETDEWEB)

    Maunz, Peter Lukas Wilhelm

    2017-04-01

    Qubits can be encoded in clock states of trapped ions. These states are well isolated from the environment resulting in long coherence times [1] while enabling efficient high-fidelity qubit interactions mediated by the Coulomb coupled motion of the ions in the trap. Quantum states can be prepared with high fidelity and measured efficiently using fluorescence detection. State preparation and detection with 99.93% fidelity have been realized in multiple systems [1,2]. Single qubit gates have been demonstrated below rigorous fault-tolerance thresholds [1,3]. Two qubit gates have been realized with more than 99.9% fidelity [4,5]. Quantum algorithms have been demonstrated on systems of 5 to 15 qubits [6–8].

  13. Negative ion sourcery

    International Nuclear Information System (INIS)

    Os, C.F.A. van.

    1989-01-01

    The work described in this thesis is involved by current research programs in the field of nuclear-fusion. A brief introduction to fusion is given, anticipated problems related to current drive of the fusion plasma are pinpointed and probable suggestions to overcome these problems are described. One probable means for current drive is highlighted; Neutral Beam Injection (NBI). This is based on injecting a 1 MeV neutral hydrogen or deuterium beam into a fusion plasma. Negative ions are needed as primary particles because they can easily be neutralized at 1 MeV. The two current schemes for production of negative ions are described, volume production and negative surface ionization. The latter method is extensively studied in this thesis. (author). 171 refs.; 55 figs.; 7 tabs

  14. Heavy ion fusion III

    International Nuclear Information System (INIS)

    Hammer, D.; Max, C.; Perkins, F.; Rosenbluth, M.

    1987-03-01

    This report updates Heavy Ion Fusion, JSR-82-302, dated January, 1983. During the last four years, program management and direction has been changed and the overall Inertial Confinement Program has been reviewed. This report therefore concentrates on accelerator physics issues, how the program has addressed those issues during the last four years, and how it will be addressing them in the future. 8 refs., 3 figs

  15. Ion funnel device

    Energy Technology Data Exchange (ETDEWEB)

    Ibrahim, Yehia M.; Chen, Tsung-Chi; Harrer, Marques B.; Tang, Keqi; Smith, Richard D.

    2017-11-21

    An ion funnel device is disclosed. A first pair of electrodes is positioned in a first direction. A second pair of electrodes is positioned in a second direction. The device includes an RF voltage source and a DC voltage source. A RF voltage with a superimposed DC voltage gradient is applied to the first pair of electrodes, and a DC voltage gradient is applied to the second pair of electrodes.

  16. Recombination of cluster ions

    Science.gov (United States)

    Johnsen, Rainer

    1993-01-01

    Some of our recent work on molecular band emissions from recombination of molecular dimer ions (N4(+) and CO(+) CO) is discussed. Much of the experimental work was done by Y. S. Cao; the results on N4(+) recombination have been published. A brief progress report is given on our ongoing measurements of neutral products of recombination using the flowing-afterglow Langmuir-probe technique in conjunction with laser-induced fluorescence.

  17. Cancer therapy with ions

    International Nuclear Information System (INIS)

    Mandrillon, P.

    1993-01-01

    The treatment of tumours with charged particles, ranging from protons to 'light ions' (Carbon, Oxygen, Neon) has many advantages, but up to now has been little used because of the absence of facilities. After the successful pioneering work carried out with accelerators built for physics research, machines dedicated to this new radiotherapy are planned or already in construction. The rationale for this new radiotherapy, the accelerators and the beam delivery systems needed are presented in this paper. (orig.)

  18. Relativistic heavy ion reactions

    Energy Technology Data Exchange (ETDEWEB)

    Brink, D M

    1989-08-01

    The theory of quantum chromodynamics predicts that if nuclear matter is heated to a sufficiently high temperature then quarks might become deconfined and a quark-gluon plasma could be produced. One of the aims of relativistic heavy ion experiments is to search for this new state of matter. These lectures survey some of the new experimental results and give an introduction to the theories used to interpret them. 48 refs., 4 tabs., 11 figs.

  19. Ion optics for accelerators

    International Nuclear Information System (INIS)

    Enge, H.A.

    1974-01-01

    A review is given of ion-optic devices used in particle accelerators, including electrostatic lenses, magnetic quadrupoles, and deflecting magnets. Tube focusing in dc accelerators is also treated, and a novel scheme for shaping the electrodes to produce strong focusing is described. The concepts of emittance (phase space) and emittance conservation are briefly discussed. Chromatic and spatial aberrations are introduced, and it is shown how they can be calculated and sometimes substantially reduced. Some examples are given

  20. Relativistic heavy ion physics

    International Nuclear Information System (INIS)

    Hansen, O.

    1985-01-01

    In the fall of 1986 beams of heavy ions up to A ∼ 40 at total energies up to E ∼ 225 GeV/-nucleon will become available for experiments at CERN (60 and 225 GeV/nucleon) and at Brookhaven (15.5 GeV/nucleon). Are these energies interesting in relation to the ideas of creating quark deconfinement? An energy consideration of the planned experiments is presented, as well as a description of the experimental arrangement. (Auth.)

  1. Fungitoxicity of metal ions

    Energy Technology Data Exchange (ETDEWEB)

    Somers, E

    1961-01-01

    The in vitro fungistatic activity of some twenty-four metal cations has been determine against Alternaria tenuis and Botrytis fabae. The metal salts, mainly nitrates, were tested in aqueous solution without added spore germination stimulant. The logarithm of the metal ion concentration at the ED 50 value has been found to conform to the exponenttial relationship with electronegativity proposed by Danielli and Davies (1951). These results are discussed in relation to the site of action of metal cations on the fungal cell.

  2. Negative ion beam processes

    International Nuclear Information System (INIS)

    Hayward, T.D.; Lawrence, G.P.; Bentley, R.F.; Malanify, J.J.; Jackson, J.A.

    1975-06-01

    Los Alamos Scientific Laboratory fiscal year 1975 work on production of intense, very bright, negative hydrogen (H - ), ion beams and conversion of a high-energy (a few hundred MeV) negative beam into a neutral beam are described. The ion source work has used a cesium charge exchange source that has produced H - ion beams greater than or equal to 10 mA (about a factor of 10 greater than those available 1 yr ago) with a brightness of 1.4 x 10 9 A/m 2 -rad 2 (about 18 times brighter than before). The high-energy, neutral beam production investigations have included measurements of the 800-MeV H - -stripping cross section in hydrogen gas (sigma/sub -10/, tentatively 4 x 10 -19 cm 2 ), 3- to 6-MeV H - -stripping cross sections in a hydrogen plasma (sigma/sub -10/, tentatively 2 to 4 x 10 -16 cm 2 ), and the small-angle scattering that results from stripping an 800-MeV H - ion beam to a neutral (H 0 ) beam in hydrogen gas. These last measurements were interrupted by the Los Alamos Meson Physics Facility shutdown in December 1974, but should be completed early in fiscal year 1976 when the accelerator resumes operation. Small-angle scattering calculations have included hydrogen gas-stripping, plasma-stripping, and photodetachment. Calculations indicate that the root mean square angular spread of a 390-MeV negative triton (T - ) beam stripped in a plasma stripper may be as low as 0.7 μrad

  3. Relativistic heavy ion reactions

    International Nuclear Information System (INIS)

    Brink, D.M.

    1989-08-01

    The theory of quantum chromodynamics predicts that if nuclear matter is heated to a sufficiently high temperature then quarks might become deconfined and a quark-gluon plasma could be produced. One of the aims of relativistic heavy ion experiments is to search for this new state of matter. These lectures survey some of the new experimental results and give an introduction to the theories used to interpret them. 48 refs., 4 tabs., 11 figs

  4. Small size ion pumps

    International Nuclear Information System (INIS)

    Cyranski, R.; Kiliszek, Cz.R.; Marks, J.; Sobolewski, A.; Magielko, H.

    2001-01-01

    This paper describes some designs of the two versions ion pumps and their range operation for various magnetic fields. The first version is made with different cell size in the anode element and titanium cathode operating in magnetic field from 600 to 650 Gs and the second version with the same anode element but differential Ti/Ta cathode working in magnetic field above 1200 Gs

  5. Ion Trap Quantum Computing

    Science.gov (United States)

    2011-12-01

    variations of ion traps, including (1) the cylindrically symmetric 3D ring trap; (2) the linear trap with a combination of cavity QED; (#) the symmetric...concepts of quantum information. The major demonstration has been the test of a Bell inequality as demonstrated by Rowe et al. [50] and a decoherence...famous physics experiment [62]. Wolfgang Paul demonstrated a similar apparatus during his Nobel Prize speech [63]. This device is hyperbolic- parabolic

  6. Investigation on Ion Source Parameters

    CERN Document Server

    M. Cheikh Mhamed, S. Essabaa, C. Lau

    The EURISOL multi-mega-watt target station requires dedicated radioactive ion sources. Notably, they must be capable of operating under extremely hard radiations and with a larger fission target producing over 1014 fissions/s. The realisation of next-generation ion sources suitable for such operating conditions needs exhaustive studies and developments. In order to take up such a challenge, a review on radioactive ion sources was achieved and the investigation on ion source parameters was in particular focused on a plasma ion source through a R&D program.

  7. Ion sources for medical accelerators

    Science.gov (United States)

    Barletta, W. A.; Chu, W. T.; Leung, K. N.

    1998-02-01

    Advanced injector systems for proton synchrotrons and accelerator-based boron neutron capture therapy systems are being developed at the Lawrence Berkeley National Laboratory. Multicusp ion sources, particularly those driven by radio frequency, have been tested for these applications. The use of a radio frequency induction discharge provides clean, reliable, and long-life source operation. It has been demonstrated that the multicusp ion source can provide good-quality positive hydrogen ion beams with a monatomic ion fraction higher than 90%. The extractable ion current densities from this type of source can meet the injector requirements for both proton synchrotron and accelerator-based boron neutron capture therapy projects.

  8. Ion-acoustic plasma turbulence

    International Nuclear Information System (INIS)

    Bychenkov, V.Y.; Silin, V.P.

    1982-01-01

    A theory is developed of the nonlinear state that is established in a plasma as a result of development of ion-acoustic instability. Account is taken simultaneously of the linear induced scattering of the waves by the ions and of the quasilinear relaxation of the electrons by the ion-acoustic pulsations. The distribution of the ion-acoustic turbulence in frequency and in angle is obtained. An Ohm's law is established and expressions are obtained for the electronic heat flux and for the relaxation time of the electron temperature in a turbulent plasma. Anomalously large absorption and scattering of the electromagnetic waves by the ion-acoustic pulsations is predicted

  9. GANIL Workshop on Ion Sources

    International Nuclear Information System (INIS)

    Leroy, Renan

    1999-01-01

    The proceedings of the GANIL Workshop on Ion Sources held at GANIL - Caen on 18-19 March 1999 contains 13 papers aiming at improving the old source operation and developing new types of sources for nuclear research and studies of ion physics. A number of reports are devoted to applications like surface treatment, ion implantation or fusion injection. The 1+→n+ transformation, charged particle transport in ECR sources, addition of cesium and xenon in negative ion sources and other basic issues in ion sources are also addressed

  10. Ion channeling revisited

    Energy Technology Data Exchange (ETDEWEB)

    Doyle, Barney Lee [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Corona, Aldo [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Nguyen, Anh [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2014-09-01

    A MS Excel program has been written that calculates accidental, or unintentional, ion channeling in cubic bcc, fcc and diamond lattice crystals or polycrystalline materials. This becomes an important issue when simulating the creation by energetic neutrons of point displacement damage and extended defects using beams of ions. All of the tables and graphs in the three Ion Beam Analysis Handbooks that previously had to be manually looked up and read from were programed into Excel in handy lookup tables, or parameterized, for the case of the graphs, using rather simple exponential functions with different powers of the argument. The program then offers an extremely convenient way to calculate axial and planar half-angles and minimum yield or dechanneling probabilities, effects on half-angles of amorphous overlayers, accidental channeling probabilities for randomly oriented crystals or crystallites, and finally a way to automatically generate stereographic projections of axial and planar channeling half-angles. The program can generate these projections and calculate these probabilities for axes and [hkl] planes up to (555).

  11. Collective ion acceleration

    International Nuclear Information System (INIS)

    Godfrey, B.B.; Faehl, R.J.; Newberger, B.S.; Shanahan, W.R.; Thode, L.E.

    1977-01-01

    Progress achieved in the understanding and development of collective ion acceleration is presented. Extensive analytic and computational studies of slow cyclotron wave growth on an electron beam in a helix amplifier were performed. Research included precise determination of linear coupling between beam and helix, suppression of undesired transients and end effects, and two-dimensional simulations of wave growth in physically realizable systems. Electrostatic well depths produced exceed requirements for the Autoresonant Ion Acceleration feasibility experiment. Acceleration of test ions to modest energies in the troughs of such waves was also demonstrated. Smaller efforts were devoted to alternative acceleration mechanisms. Langmuir wave phase velocity in Converging Guide Acceleration was calculated as a function of the ratio of electron beam current to space-charge limiting current. A new collective acceleration approach, in which cyclotron wave phase velocity is varied by modulation of electron beam voltage, is proposed. Acceleration by traveling Virtual Cathode or Localized Pinch was considered, but appears less promising. In support of this research, fundamental investigations of beam propagation in evacuated waveguides, of nonneutral beam linear eigenmodes, and of beam stability were carried out. Several computer programs were developed or enhanced. Plans for future work are discussed

  12. Ion temperature gradient instability

    International Nuclear Information System (INIS)

    1989-01-01

    Anomalous ion thermal conductivity remains an open physics issue for the present generation of high temperature Tokamaks. It is generally believed to be due to Ion Temperature Gradient Instability (η i mode). However, it has been difficult, if not impossible to identify this instability and study the anomalous transport due to it, directly. Therefore the production and identification of the mode is pursued in the simpler and experimentally convenient configuration of the Columbia Linear Machine (CLM). CLM is a steady state machine which already has all the appropriate parameters, except η i . This parameter is being increased to the appropriate value of the order of 1 by 'feathering' a tungsten screen located between the plasma source and the experimental cell to flatten the density profile and appropriate redesign of heating antennas to steepen the ion temperature profile. Once the instability is produced and identified, a thorough study of the characteristics of the mode can be done via a wide range of variation of all the critical parameters: η i , parallel wavelength, etc

  13. Ion-induced sputtering

    International Nuclear Information System (INIS)

    Yamamura, Yasumichi; Shimizu, Ryuichi; Shimizu, Hazime; Ito, Noriaki.

    1983-01-01

    The research on ion-induced sputtering has been continued for a long time, since a hundred or more years ago. However, it was only in 1969 by Sigmund that the sputtering phenomena were theoretically arranged into the present form. The reason why the importance of sputtering phenomena have been given a new look recently is the application over wide range. This paper is a review centering around the mechanism of causing sputtering and its characteristics. Sputtering is such a phenomenon that the atoms in the vicinity of a solid surface are emitted into vacuum by receiving a part of ion energy, or in other words, it is a kind of irradiation damage in the vicinity of a solid surface. In this meaning, it can be considered that the sputtering based on the ions located on the clean surface of a single element metal is simple, and has already been basically understood. On the contrary, the phenomena can not be considered to be fully understood in the case of alloys and compounds, because these surface conditions under irradiation are not always clear due to segregation and others. In the paper, the physical of sputtering, single element sputtering, the sputtering in alloys and compounds, and the behaviour of emitted particles are explained. Finally, some recent topics of the sputtering measurement by laser resonant excitation, the sputtering by electron excitation, chemical sputtering, and the sputtering in nuclear fusion reactors are described. (Wakatsuki, Y.)

  14. Determinação espectrofotométrica de aspartame em adoçantes por injeção em fluxo usando um reator em fase sólida contendo fosfato de zinco imobilizado

    Directory of Open Access Journals (Sweden)

    Pereira Airton Vicente

    2000-01-01

    Full Text Available A flow injection spectrophotometric method was developed for determining aspartame in sweeteners. Sample was dissolved in water and 250 µL of the solution was injected into a carrier stream of 5.0 x 10-5 mol L-1 sodium borate solution. The sample flowed through a column (14 cm x 2.0 mm packed with Zn3(PO42 immobilized in a polymeric matrix of polyester resin and Zn(II ions were released from the solid-phase reactor by formation of the Zn(II-aspartame complex. The mixture merged with a stream of borate buffer solution (pH 9.0 containing 0.030 % (m/v alizarin red S and the Zn(II-alizarin red complex formed was measured spectrophotometrically at 540 nm. The calibration graph for aspartame was linear in the concentration range from 10 to 80 µg mL-1 with a detection limit of 4 µg mL-1 of aspartame. The RSD was 0.3 % for a solution containing 40 µg mL-1 aspartame (n = 10 and seventy results were obtained per hour. The proposed method was applied for determining aspartame in commercial sweeteners.

  15. Ion source with plasma cathode

    International Nuclear Information System (INIS)

    Yabe, E.

    1987-01-01

    A long lifetime ion source with plasma cathode has been developed for use in ion implantation. In this ion source, a plasma of a nonreactive working gas serves as a cathode in place of a thermionic tungsten filament used in the Freeman ion source. In an applied magnetic field, the plasma is convergent, i.e., filamentlike; in zero magnetic field, it turns divergent and spraylike. In the latter case, the plasma exhibits a remarkable ability when the working gas has an ionization potential larger than the feed gas. By any combination of a working gas of either argon or neon and a feed gas of AsF 5 or PF 5 , the lifetime of this ion source was found to be more than 90 h with an extraction voltage of 40 kV and the corresponding ion current density 20 mA/cm 2 . Mass spectrometry results show that this ion source has an ability of generating a considerable amount of As + and P + ions from AsF 5 and PF 5 , and hence will be useful for realizing a fully cryopumped ion implanter system. This ion source is also eminently suitable for use in oxygen ion production

  16. Ion source of discharge type

    Energy Technology Data Exchange (ETDEWEB)

    Enchevich, I.B. [TRIUMF, Cyclotron Div., Vancouver, British Columbia (Canada); Korenev, S.A. [JINR, Hihg Energy Physics Lab., Dubna, Moscow (Russian Federation)

    1992-07-01

    A new scheme of ion source based on a dielectric surface sliding discharge is described. The conditions to form this type of discharge are analyzed and experimental results are shown. The main parameters of this ion source are: accelerating voltage U = 1/20kV; continuous extracted ion beam; current density j = 0.01/0.5 A/cm{sup 2}; ions of Cl, F, C, H; residual gas pressure P = 10{sup -6} Torr. A magnetic system is used to separate the different types of ions. The dielectric material in the discharge circuit (anode plasma emitter) defines the type of ions. The emission characteristics of plasma emitter and the discharge parameters are presented. The ion current yield satisfies the Child-Langmuir law. (author)

  17. Ion source of discharge type

    International Nuclear Information System (INIS)

    Enchevich, I.B.; Korenev, S.A.

    1992-07-01

    A new scheme of ion source based on a dielectric surface sliding discharge is described. The conditions to form this type of discharge are analyzed and experimental results are shown. The main parameters of this ion source are: accelerating voltage U = 1/20kV; continuous extracted ion beam; current density j = 0.01/0.5 A/cm 2 ; ions of Cl, F, C, H; residual gas pressure P = 10 -6 Torr. A magnetic system is used to separate the different types of ions. The dielectric material in the discharge circuit (anode plasma emitter) defines the type of ions. The emission characteristics of plasma emitter and the discharge parameters are presented. The ion current yield satisfies the Child-Langmuir law. (author)

  18. Resonance Ionization Laser Ion Sources

    CERN Document Server

    Marsh, B

    2013-01-01

    The application of the technique of laser resonance ionization to the production of singly charged ions at radioactive ion beam facilities is discussed. The ability to combine high efficiency and element selectivity makes a resonance ionization laser ion source (RILIS) an important component of many radioactive ion beam facilities. At CERN, for example, the RILIS is the most commonly used ion source of the ISOLDE facility, with a yearly operating time of up to 3000 hours. For some isotopes the RILIS can also be used as a fast and sensitive laser spectroscopy tool, provided that the spectral resolution is sufficiently high to reveal the influence of nuclear structure on the atomic spectra. This enables the study of nuclear properties of isotopes with production rates even lower than one ion per second and, in some cases, enables isomer selective ionization. The solutions available for the implementation of resonance laser ionization at radioactive ion beam facilities are summarized. Aspects such as the laser r...

  19. A review of polarized ion sources

    International Nuclear Information System (INIS)

    Schmor, P.W.

    1995-06-01

    The two main types of polarized ion sources in use on accelerators today are the Atomic Beam Polarized Ion Source (ABIS) source and the Optically Pumped Polarized Ion Source (OPPIS). Both types can provide beams of nuclearly polarized light ions which are either positively or negatively charged. Heavy ion polarized ion sources for accelerators are being developed. (author). 35 refs., 1 tab

  20. Unimolecular and collisionally induced ion reactions

    International Nuclear Information System (INIS)

    Beynon, J.H.; Boyd, R.K.

    1978-01-01

    The subject is reviewed under the following headings: introduction (mass spectroscopy and the study of fragmentation reactions of gaseous positive ions); techniques and methods (ion sources, detection systems, analysis of ions, data reduction); collision-induced reactions of ions and unimolecular fragmentations of metastable ions; applications (ion structure, energetic measurements, analytical applications, other applications). 305 references. (U.K.)

  1. Electron string ion sources for carbon ion cancer therapy accelerators

    Science.gov (United States)

    Boytsov, A. Yu.; Donets, D. E.; Donets, E. D.; Donets, E. E.; Katagiri, K.; Noda, K.; Ponkin, D. O.; Ramzdorf, A. Yu.; Salnikov, V. V.; Shutov, V. B.

    2015-08-01

    The type of the Electron String Ion Sources (ESIS) is considered to be the appropriate one to produce pulsed C4+ and C6+ ion beams for cancer therapy accelerators. In fact, the new test ESIS Krion-6T already now provides more than 1010 C4+ ions per pulse and about 5 × 109 C6+ ions per pulse. Such ion sources could be suitable to apply at synchrotrons. It has also been found that Krion-6T can provide more than 1011 C6+ ions per second at the 100 Hz repetition rate, and the repetition rate can be increased at the same or larger ion output per second. This makes ESIS applicable at cyclotrons as well. ESIS can be also a suitable type of ion source to produce the 11C radioactive ion beams. A specialized cryogenic cell was experimentally tested at the Krion-2M ESIS for pulse injection of gaseous species into the electron string. It has been shown in experiments with stable methane that the total conversion efficiency of methane molecules to C4+ ions reached 5%÷10%. For cancer therapy with simultaneous irradiation and precise dose control (positron emission tomography) by means of 11C, transporting to the tumor with the primary accelerated 11C4+ beam, this efficiency is preliminarily considered to be large enough to produce the 11C4+ beam from radioactive methane and to inject this beam into synchrotrons.

  2. Características nutricionais da carne de cordeiros terminados com dietas contendo cana-de-açúcar ou silagem de milho e dois níveis de concentrado Nutritional characteristics of meat from lambs finished with diets containing sugar cane or corn silage on two levels of concentrate

    Directory of Open Access Journals (Sweden)

    André Gustavo Leão

    2011-05-01

    Full Text Available Com o objetivo de avaliar as características nutricionais da carne de cordeiros terminados em confinamento com dietas contendo cana-de-açúcar ou silagem de milho em duas relações volumoso:concentrado (60:40 ou 40:60, utilizaram-se 32 cordeiros Ile de France, não-castrados, com 15 kg de peso corporal distribuídos em delineamento experimental inteiramente casualizado, em esquema fatorial 2 × 2. Os animais foram confinados em baias individuais e abatidos aos 32 kg. A carne dos cordeiros teve 74,55% de umidade, 19,61% de proteína bruta, 1,04% de cinzas e 51,28 mg/100 g de colesterol. O teor de extrato etéreo foi maior na carne dos cordeiros alimentados com dietas com silagem de milho (3,97% e na carne daqueles que receberam alimentação mais concentrada (4,02%. Os ácidos graxos em maior concentração na carne dos cordeiros foram C18:1w9 (37,93%, C16:0 (26,41%, C18:0 (17,09%, C14:0 (4,18% e C18:2w6 (4,00%. A carne dos animais alimentados com dietas contendo cana-de-açúcar apresentou maiores teores dos ácidos C10:0 (0,47% e C20:4w6 (4,17% e menores de C16:1w7 (2,02% e C18:3w3 (0,25%. A dieta com maior quantidade de cana-de-açúcar (60% promoveu maiores teores dos ácidos C15:0 (0,68%, C17:0 (2,13% e C20:2 (1,34% na carne. Dietas contendo cana-de-açúcar ou maior quantidade de volumoso (60% promovem menor deposição de gordura na carne de cordeiros. O tipo de volumoso tem maior influência no perfil de ácidos graxos da carne de cordeiro em comparação à relação volumoso:concentrado das dietas. Dietas contendo cana-de-açúcar em maiores proporções originam carne com maiores concentrações de ácidos graxos saturados de cadeia ímpar.The objective of this work was to evaluate nutritional characteristics of meat from lambs finished on feedlot with diets containing sugar cane or corn silage on two roughage:concentrate ratios (60:40 or 40:60. It was used 32 non castrated Ile de France lambs, with 15 kg of body weight distributed

  3. Efeito de um dentifrício fluoretado contendo bicarbonato de sódio na contagem de estreptococos do grupo mutans, acidogenicidade e composição da placa dental Effect of a fluorated dentifrice containing baking soda on mutans counting, acidogenicity and dental plaque composition

    Directory of Open Access Journals (Sweden)

    Rosa Fernanda IGNÁCIO

    1999-01-01

    Full Text Available Avaliou-se o efeito de um dentifrício contendo bicarbonato de sódio na contagem de estreptococos do grupo mutans (EM, acidogenicidade e composição da placa dental. Vinte e três voluntários escovaram os dentes 3 vezes ao dia, com formulações fluoretadas (1.500 ppm F, contendo, ou sílica (SÍLICA, ou carbonato de cálcio (CARBONATO, ou carbonato de cálcio mais bicarbonato de sódio (CARB/BICAR, num delineamento duplo cego cruzado, com 3 etapas de 30 dias. No 28º dia, 8 a 12 horas após a última escovação, foi realizada a contagem de estreptococos do grupo mutans na saliva (EMS. No 30º dia (após 2 dias, nos quais os voluntários bochecharam 3 vezes/dia uma suspensão do dentifrício em água, e 6 vezes/dia sacarose a 10%, analisou-se na placa dental, após 10 a 12 horas do último bochecho de dentifrício: a contagem de mutans (EMP; b polissacarídeos álcali solúveis (PSA; c flúor solúvel em ácido (FSA; d pH no tempo zero (T0, após 5 minutos de bochecho com sacarose (T5, calculando-se o DpH (T0-T5. Os resultados (média + erro padrão para SÍLICA, CARBONATO e CARB/BICAR foram respectivamente:1 EMS (x106 UFC/ml saliva = 11,43 + 7,62 A; 2,33 + 1,04 A; 2,07 + 1,10 A; 2 EMP (x106 UFC/mg placa = 0,099 + 0,095 A; 0,027 + 0,018 A; 0,007 + 0,003 A; 3 PSA (mg/mg placa = 6,89 + 0,62 AC; 8,46 + 0,80 AB; 6,11 + 0,59 C; 4 FSA ((mg/g placa = 36,67 + 10,10 A; 48,12 + 19,23 A; 52,21 + 15,12 A; 5 T0 = 6,72 + 0,12 A; 6,88 + 0,13 A; 6,65 + 0,11 A; 6 T5 = 5,61 + 0,13 A; 5,71 + 0,13 A; 5,70 + 0,12 A; 7 DpH = 1,12 + 0,11 A; 1,17 + 0,11 A; 0,95 + 0,10 A, sendo que médias seguidas por letras distintas diferem entre si ao nível de 5% de significância. Os resultados demonstram que, embora o dentifrício contendo bicarbonato de sódio tenha apresentado, coletivamente, uma tendência a influenciar positivamente nos diversos fatores relacionados à cárie dental, não diferiu significantemente dos dentifrícios contendo carbonato de cálcio ou s

  4. Diffuse ions produced by electromagnetic ion beam instabilities

    International Nuclear Information System (INIS)

    Winske, D.; Leroy, M.M.

    1984-01-01

    The evolution of the electromagnetic ions beam instability driven by the reflected ion component backstreaming away from the earth's how shock into the foreshock region is studied by means computer simulation. The linear the quasi-linear states of the instability are found to be in good agreement with known results for the resonant model propagating parallel to the beam along the magnetic field and with theory developed in this paper for the nonresonant mode, which propagates antiparallel to the beam direction. The quasi-linear stage, which produces large amplitude 8Bapprox.B, sinusoidal transverse waves and ''intermediate'' ion distribution, is terminated by a nonlinear phase in which strongly nonlinear, compressive waves and ''diffuse'' ion distributions are produced. Additional processes by which the diffuse ions are accelerated to observed high energies are not addressed. The results are discussed in terms of the ion distributions and hydromagnetic waves observed in the foreshock of the earth's bow shock and of interplanetary shocks

  5. Gas and metal ion sources

    International Nuclear Information System (INIS)

    Oaks, E.; Yushkov, G.

    1996-01-01

    The positive ion sources are now of interest owing to both their conventional use, e.g., as injectors in charged-particle accelerators and the promising capabilities of intense ion beams in the processes related to the action of ions on various solid surfaces. For industrial use, the sources of intense ion beams and their power supplies should meet the specific requirements as follows: They should be simple, technologically effective, reliable, and relatively low-cost. Since the scanning of an intense ion beam is a complicated problem, broad ion beams hold the greatest promise. For the best use of such beams it is desirable that the ion current density be uniformly distributed over the beam cross section. The ion beam current density should be high enough for the treatment process be accomplished for an acceptable time. Thus, the ion sources used for high-current, high-dose metallurgical implantation should provide for gaining an exposure dose of ∼ 10 17 cm -2 in some tens of minutes. So the average ion current density at the surface under treatment should be over 10 -5 A/cm 2 . The upper limit of the current density depends on the admissible heating of the surface under treatment. The accelerating voltage of an ion source is dictated by its specific use; it seems to lie in the range from ∼1 kV (for the ion source used for surface sputtering) to ∼100 kV and over (for the ion sources used for high-current, high-dose metallurgical implantation)

  6. Cobalt alloy ion sources for focused ion beam implantation

    Energy Technology Data Exchange (ETDEWEB)

    Muehle, R.; Doebeli, M. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Zimmermann, P. [Eidgenoessische Technische Hochschule, Zurich (Switzerland)

    1997-09-01

    Cobalt alloy ion sources have been developed for silicide formation by focused ion beam implantation. Four eutectic alloys AuCo, CoGe, CoY and AuCoGe were produced by electron beam welding. The AuCo liquid alloy ion source was investigated in detail. We have measured the emission current stability, the current-voltage characteristics, and the mass spectrum as a function of the mission current. (author) 1 fig., 2 refs.

  7. Ion structure and sequence of ion formation in acetylene flames

    Energy Technology Data Exchange (ETDEWEB)

    Larionova, I.A.; Fialkov, B.S.; Kalinich, K.YA.; Fialkov, A.B.; Ospanov, B.S.

    1993-06-01

    Results of a study of the ion composition of acetylene-air flames burning at low pressures are reported. Data on ion formation are compared for flames of saturated hydrocarbons, oxygen-containing fuels, and acetylene. It is shown that the characteristics of ion formation in the flame front and directly ahead of it are similar to those observed in flames of other fuels. These characteristics, however, are different in the low-temperature region. 9 refs.

  8. Ion channels in plants.

    Science.gov (United States)

    Hedrich, Rainer

    2012-10-01

    Since the first recordings of single potassium channel activities in the plasma membrane of guard cells more than 25 years ago, patch-clamp studies discovered a variety of ion channels in all cell types and plant species under inspection. Their properties differed in a cell type- and cell membrane-dependent manner. Guard cells, for which the existence of plant potassium channels was initially documented, advanced to a versatile model system for studying plant ion channel structure, function, and physiology. Interestingly, one of the first identified potassium-channel genes encoding the Shaker-type channel KAT1 was shown to be highly expressed in guard cells. KAT1-type channels from Arabidopsis thaliana and its homologs from other species were found to encode the K(+)-selective inward rectifiers that had already been recorded in early patch-clamp studies with guard cells. Within the genome era, additional Arabidopsis Shaker-type channels appeared. All nine members of the Arabidopsis Shaker family are localized at the plasma membrane, where they either operate as inward rectifiers, outward rectifiers, weak voltage-dependent channels, or electrically silent, but modulatory subunits. The vacuole membrane, in contrast, harbors a set of two-pore K(+) channels. Just very recently, two plant anion channel families of the SLAC/SLAH and ALMT/QUAC type were identified. SLAC1/SLAH3 and QUAC1 are expressed in guard cells and mediate Slow- and Rapid-type anion currents, respectively, that are involved in volume and turgor regulation. Anion channels in guard cells and other plant cells are key targets within often complex signaling networks. Here, the present knowledge is reviewed for the plant ion channel biology. Special emphasis is drawn to the molecular mechanisms of channel regulation, in the context of model systems and in the light of evolution.

  9. Positive ion irradiation facility

    International Nuclear Information System (INIS)

    Braby, L.A.

    1985-01-01

    Many questions about the mechanisms of the response of cells to ionizing radiation can best be investigated using monoenergetic heavy charged particle beams. Questions of the role of different types of damage in the LET effect, for example, are being answered by comparing repair kinetics for damage induced by electrons with that produced by helium ions. However, as the models become more sophicated, the differences between models can be detected only with more precise measurements, or by combining high- and low-LET irradiations in split-dose experiments. The design of the authors present cell irradiation beam line has limited the authors to irradiating cells in a partial vacuum. A new way to mount the dishes and bring the beam to the cells was required. Several means of irradiating cells in mylar-bottom dishes have been used at other laboratories. For example at the RARAF Facility, the dual ion experiments are done with the dish bottom serving as the beam exit window but the cells are in a partial vacuum to prevent breaking the window. These researchers have chosen instead to use the dish bottom as the beam window and to irradiate the entire dish in a single exposure. A special, very fast pumping system will be installed at the end of the beam line. This system will make it possible to irradiate cells within two minutes of installing them in the irradiation chamber. In this way, the interaction of electron and ion-induced damage in Chlamydomonas can be studied with time between doses as short as 5 minutes

  10. Practical aspects of trapped ion mass spectrometry, 5 applications of ion trapping devices

    CERN Document Server

    March, Raymond E

    2009-01-01

    Examines ion/neutral and ion/ion reactions, ion spectroscopy, and the structural characterization of proteins and peptides using quadropole ion trap mass spectrometry, Fourier transform - ion cyclotron resonance (FT-ICR) mass spectrometry, and traveling wave ion mobility mass spectrometry.

  11. High energy ion implantation

    International Nuclear Information System (INIS)

    Ziegler, J.F.

    1985-01-01

    High energy ion implantation offers the oppertunity for unique structures in semiconductor processing. The unusual physical properties of such implantations are discussed as well as the special problems in masking and damage annealing. A review is made of proposed circuit structures which involve deep implantation. Examples are: deep buried bipolar collectors fabricated without epitaxy, barrier layers to reduce FET memory sensitivity to soft-fails, CMOS isolation well structures, MeV implantation for customization and correction of completed circuits, and graded reach-throughs to deep active device components. (orig.)

  12. Physics of ion sputtering

    International Nuclear Information System (INIS)

    Robinson, M.T.

    1984-04-01

    The ejection of atoms by the ion bombardment of solids is discussed in terms of linear collision cascade theory. A simple argument describes the energies of the ejecta, but elaborate models are required to obtain accurate sputtering yields and related quantities. These include transport theoretical models based on linearized Boltzmann equations, computer simulation models based on the binary collision approximation, and classical many-body dynamical models. The role of each kind of model is discussed. Several aspects of sputtering are illustrated by results from the simulation code MARLOWE. 20 references, 6 figures

  13. Ion implantation for semiconductors

    International Nuclear Information System (INIS)

    Grey-Morgan, T.

    1995-01-01

    Full text: Over the past two decades, thousands of particle accelerators have been used to implant foreign atoms like boron, phosphorus and arsenic into silicon crystal wafers to produce special embedded layers for manufacturing semiconductor devices. Depending on the device required, the atomic species, the depth of implant and doping levels are the main parameters for the implantation process; the selection and parameter control is totally automated. The depth of the implant, usually less than 1 micron, is determined by the ion energy, which can be varied between 2 and 600 keV. The ion beam is extracted from a Freeman or Bernas type ion source and accelerated to 60 keV before mass analysis. For higher beam energies postacceleration is applied up to 200 keV and even higher energies can be achieved by mass selecting multiplycharged ions, but with a corresponding reduction in beam output. Depending on the device to be manufactured, doping levels can range from 10 10 to 10 15 atoms/cm 2 and are controlled by implanter beam currents in the range up to 30mA; continuous process monitoring ensures uniformity across the wafer of better than 1 % . As semiconductor devices get smaller, additional sophistication is required in the design of the implanter. The silicon wafers charge electrically during implantation and this charge must be dissipated continuously to reduce the electrical stress in the device and avoid destructive electrical breakdown. Electron flood guns produce low energy electrons (below 10 electronvolts) to neutralize positive charge buildup and implanter design must ensure minimum contamination by other isotopic species and ensure low internal sputter rates. The pace of technology in the semiconductor industry is such that implanters are being built now for 256 Megabit circuits but which are only likely to be widely available five years from now. Several specialist companies manufacture implanter systems, each costing around US$5 million, depending on the

  14. Compact ion accelerator source

    Science.gov (United States)

    Schenkel, Thomas; Persaud, Arun; Kapadia, Rehan; Javey, Ali

    2014-04-29

    An ion source includes a conductive substrate, the substrate including a plurality of conductive nanostructures with free-standing tips formed on the substrate. A conductive catalytic coating is formed on the nanostructures and substrate for dissociation of a molecular species into an atomic species, the molecular species being brought in contact with the catalytic coating. A target electrode placed apart from the substrate, the target electrode being biased relative to the substrate with a first bias voltage to ionize the atomic species in proximity to the free-standing tips and attract the ionized atomic species from the substrate in the direction of the target electrode.

  15. Ion channels in glioblastoma.

    Science.gov (United States)

    Molenaar, Remco J

    2011-01-01

    Glioblastoma is the most common primary brain tumor with the most dismal prognosis. It is characterized by extensive invasion, migration, and angiogenesis. Median survival is only 15 months due to this behavior, rendering focal surgical resection ineffective and adequate radiotherapy impossible. At this moment, several ion channels have been implicated in glioblastoma proliferation, migration, and invasion. This paper summarizes studies on potassium, sodium, chloride, and calcium channels of glioblastoma. It provides an up-to-date overview of the literature that could ultimately lead to new therapeutic targets.

  16. Relativistic heavy ion collisions

    International Nuclear Information System (INIS)

    Barz, H.W.; Kaempfer, B.; Schulz, H.

    1984-12-01

    An elementary introduction is given into the scenario of relativistic heavy ion collisions. It deals with relativistic kinematics and estimates of energy densities, extrapolations of the present knowledge of hadron-hadron and hadron-nuleus to nucleus-nucleus collisions, the properties of the quark-gluon plasma and the formation of the plasma and possible experimental signatures. Comments are made on a cosmic ray experiment which could be interpreted as a first indication of the quark-gluon phase of the matter. (author)

  17. Contact ionization ion source

    International Nuclear Information System (INIS)

    Hashmi, N.; Van Der Houven Van Oordt, A.J.

    1975-01-01

    An ion source in which an apertured or foraminous electrode having a multiplicity of openings is spaced from one or more active surfaces of an ionisation electrode, the active surfaces comprising a material capable of ionising by contact ionization a substance to be ionized supplied during operation to the active surface or surfaces comprises means for producing during operation a magnetic field which enables a stable plasma to be formed in the space between the active surface or surfaces and the apertured electrode, the field strength of the magnetic field being preferably in the range between 2 and 8 kilogauss. (U.S.)

  18. Nanostructuring by ion beam

    International Nuclear Information System (INIS)

    Valbusa, U.; Boragno, C.; Buatier de Mongeot, F.

    2003-01-01

    In metals, the surface curvature dependence of the sputtering yield and the presence of an extra energy barrier whenever diffusing adatoms try to descend step edges, produce a similar surface instability, which builds up regular patterns. By tuning the competition between these two mechanisms, it is possible to create self-organized structures of the size of few nanometers. Height, lateral distance and order of the structures change with the deposition parameters like ion energy, dose, incident angle and substrate temperature. The paper offers an overview of the experiments carried out and foresees possible applications of these results in the area of material science

  19. Sympathetic cooling of ions in a hybrid atom ion trap

    Energy Technology Data Exchange (ETDEWEB)

    Hoeltkemeier, Bastian

    2016-10-27

    In this thesis the dynamics of a trapped ion immersed in a spatially localized buffer gas is investigated. For a homogeneous buffer gas, the ion's energy distribution reaches a stable equilibrium only if the mass of the buffer gas atoms is below a critical value. This limitation can be overcome by using multipole traps in combination and/or a spatially confined buffer gas. Using a generalized model for elastic collisions of the ion with the buffer gas atoms, the ion's energy distribution is numerically determined for arbitrary buffer gas distributions and trap parameters. Three regimes characterized by the respective analytic form of the ion's equilibrium energy distribution are found. One of these is a novel regime at large atom-to-ion mass ratios where the final ion temperature can tuned by adiabatically decreasing the spatial extension of the buffer gas and the effective ion trap depth (forced sympathetic cooling). The second part of the thesis presents a hybrid atom ion trap designed for sympathetic cooling of hydroxide anions. In this hybrid trap the anions are immersed in a cloud of laser cooled rubidium atoms. The translational and rovibrational temperatures of the anions is probed by photodetachment tomography and spectroscopy which shows the first ever indication of sympathetic cooling of anions by laser cooled atoms.

  20. Heavy ion beams from the new Hungarian ECR ion source

    International Nuclear Information System (INIS)

    Biri, S.; Valek, A.; Ditroi, F.; Koivisto, H.; Arje, J.; Stiebing, K.; Schmidt, L.

    1998-01-01

    The first beams of highly charged ions in Hungary were obtained in fall of 1996. The new 14.5 GHz ECR ion source of ATOMKI produced beams of multiply charged ions with remarkable intensities at first experiments. Since then, numerous further developments were carried out. An external electrondonor electrode drastically increased the plasma density and, consequently, the intensity of highly charged ions. These upgrades concentrated mainly on beams from gaseous elements and were carried out by the ECRIS team of ATOMKI. Another series of experiments - ionising from solids - however, was done in the framework of an international collaboration. The first metal ion beam has been extracted from the ECRIS in November 1997 using the known method of Metal Ions from Volatile Compounds (MIVOC). The possibility to put the MIVOC chamber inside the ion source was also tested and the dosing regulation problem of metal vapours inside the ion source was solved. As a result, beams of more than 10 μA of highly charged Fe and Ni ions were produced. (author)

  1. Note: Ion source design for ion trap systems

    Science.gov (United States)

    Noriega, J. R.; Quevedo, M.; Gnade, B.; Vasselli, J.

    2013-06-01

    A small plasma (glow discharge) based ion source and circuit are described in this work. The ion source works by producing a high voltage pulsed discharge between two electrodes in a pressure range of 50-100 mTorr. A third mesh electrode is used for ion extraction. The electrodes are small stainless steel screws mounted in a MACOR ionization chamber in a linear arrangement. The electrode arrangement is driven by a circuit, design for low power operation. This design is a proof of concept intended for applications on small cylindrical ion traps.

  2. Fundamental processes in ion plating

    International Nuclear Information System (INIS)

    Mattox, D.M.

    1980-01-01

    Ion plating is a generic term applied to film deposition processes in which the substrate surface and/or the depositing film is subjected to a flux of high energy particles sufficient to cause changes in the interfacial region of film properties compared to a nonbombarded deposition. Ion plating is being accepted as an alternative coating technique to sputter deposition, vacuum evaporation and electroplating. In order to intelligently choose between the various deposition techniques, the fundamental mechanisms, relating to ion plating, must be understood. This paper reviews the effects of low energy ion bombardment on surfaces, interface formation and film development as they apply to ion plating and the implementation and applications of the ion plating process

  3. Proton and carbon ion therapy

    CERN Document Server

    Lomax, Tony

    2013-01-01

    Proton and Carbon Ion Therapy is an up-to-date guide to using proton and carbon ion therapy in modern cancer treatment. The book covers the physics and radiobiology basics of proton and ion beams, dosimetry methods and radiation measurements, and treatment delivery systems. It gives practical guidance on patient setup, target localization, and treatment planning for clinical proton and carbon ion therapy. The text also offers detailed reports on the treatment of pediatric cancers, lymphomas, and various other cancers. After an overview, the book focuses on the fundamental aspects of proton and carbon ion therapy equipment, including accelerators, gantries, and delivery systems. It then discusses dosimetry, biology, imaging, and treatment planning basics and provides clinical guidelines on the use of proton and carbon ion therapy for the treatment of specific cancers. Suitable for anyone involved with medical physics and radiation therapy, this book offers a balanced and critical assessment of state-of-the-art...

  4. Ion exchange technology assessment report

    International Nuclear Information System (INIS)

    Duhn, E.F.

    1992-01-01

    In the execution of its charter, the SRS Ion Exchange Technology Assessment Team has determined that ion exchange (IX) technology has evolved to the point where it should now be considered as a viable alternative to the SRS reference ITP/LW/PH process. The ion exchange media available today offer the ability to design ion exchange processing systems tailored to the unique physical and chemical properties of SRS soluble HLW's. The technical assessment of IX technology and its applicability to the processing of SRS soluble HLW has demonstrated that IX is unquestionably a viable technology. A task team was chartered to evaluate the technology of ion exchange and its potential for replacing the present In-Tank Precipitation and proposed Late Wash processes to remove Cs, Sr, and Pu from soluble salt solutions at the Savannah River Site. This report documents the ion exchange technology assessment and conclusions of the task team

  5. Mini ion trap mass spectrometer

    Science.gov (United States)

    Dietrich, D.D.; Keville, R.F.

    1995-09-19

    An ion trap is described which operates in the regime between research ion traps which can detect ions with a mass resolution of better than 1:10{sup 9} and commercial mass spectrometers requiring 10{sup 4} ions with resolutions of a few hundred. The power consumption is kept to a minimum by the use of permanent magnets and a novel electron gun design. By Fourier analyzing the ion cyclotron resonance signals induced in the trap electrodes, a complete mass spectra in a single combined structure can be detected. An attribute of the ion trap mass spectrometer is that overall system size is drastically reduced due to combining a unique electron source and mass analyzer/detector in a single device. This enables portable low power mass spectrometers for the detection of environmental pollutants or illicit substances, as well as sensors for on board diagnostics to monitor engine performance or for active feedback in any process involving exhausting waste products. 10 figs.

  6. Negative hydrogen ion production mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Bacal, M. [UPMC, LPP, Ecole Polytechnique, UMR CNRS 7648, Palaiseau (France); Wada, M. [School of Science and Engineering, Doshisha University, Kyoto 610-0321 (Japan)

    2015-06-15

    Negative hydrogen/deuterium ions can be formed by processes occurring in the plasma volume and on surfaces facing the plasma. The principal mechanisms leading to the formation of these negative ions are dissociative electron attachment to ro-vibrationally excited hydrogen/deuterium molecules when the reaction takes place in the plasma volume, and the direct electron transfer from the low work function metal surface to the hydrogen/deuterium atoms when formation occurs on the surface. The existing theoretical models and reported experimental results on these two mechanisms are summarized. Performance of the negative hydrogen/deuterium ion sources that emerged from studies of these mechanisms is reviewed. Contemporary negative ion sources do not have negative ion production electrodes of original surface type sources but are operated with caesium with their structures nearly identical to volume production type sources. Reasons for enhanced negative ion current due to caesium addition to these sources are discussed.

  7. Ion detection in mass spectrometry

    International Nuclear Information System (INIS)

    Bolbach, Gerard

    2016-03-01

    This course aims at providing some elements for a better understanding of ion detectors used in mass spectrometers, of their operations, and of their limitations. A first part addresses the functions and properties of an ideal detector, how to detect ions in gas phase, and particle detectors and ion detectors used in mass spectrometry. The second part proposes an overview of currently used detectors with respect to their operation principle: detection from the ion charge (Faraday cylinder), detection by inductive effects (FTICR, Fourier Transform Ion Cyclotron Resonance), and detection by secondary electron emission. The third part discusses the specificities of secondary electron emission. The fourth one addresses operating modes and parameters related to detectors. The sixth part proposes a prospective view on future detectors by addressing the following issues: cryo-detector, inductive effect and charge detectors, ion detection and nano materials

  8. Air ions and aerosol science

    International Nuclear Information System (INIS)

    Tammet, H.

    1996-01-01

    Collaboration between Gas Discharge and Plasma Physics, Atmospheric Electricity, and Aerosol Science is a factor of success in the research of air ions. The concept of air ion as of any carrier of electrical current through the air is inherent to Atmospheric Electricity under which a considerable statistical information about the air ion mobility spectrum is collected. A new model of air ion size-mobility correlation has been developed proceeding from Aerosol Science and joining the methods of neighboring research fields. The predicted temperature variation of the mobility disagrees with the commonly used Langevin rule for the reduction of air ion mobilities to the standard conditions. Concurrent errors are too big to be neglected in applications. The critical diameter distinguishing cluster ions and charged aerosol particles has been estimated to be 1.4 endash 1.8 nm. copyright 1996 American Institute of Physics

  9. Ion climate and radon concentration

    International Nuclear Information System (INIS)

    Busbarna, L.

    1981-01-01

    Characteristic values of radon concentration in natural ion climate and in open air were compared and the effect of artificially produced negative ion excess on the radon concentration of air was studied. The results show that the radon concentration measurable at the rise of negative ion excess is smaller than that in the case of natural equilibrium. This effect can be utilized lowering the background of the scintillation chambers, thus increasing their sensitivity. The negative ions of the artificial ion climate lower radon concentration in closed space. The question arises whether only the ion climate is responsible for the effects on the organism and on the nervous system or the radon concentration of the air also contributes to them. (author)

  10. An ion displacement membrame model.

    Science.gov (United States)

    Hladky, S B; Harris, J D

    1967-09-01

    The usual assumption in treating the diffusion of ions in an electric field has been that the movement of each ion is independent of the movement of the others. The resulting equation for diffusion by a succession of spontaneous jumps has been well stated by Parlin and Eyring. This paper will consider one simple case in which a different assumption is reasonable. Diffusion of monovalent positive ions is considered as a series of jumps from one fixed negative site to another. The sites are assumed to be full (electrical neutrality). Interaction occurs by the displacement of one ion by another. An ion leaves a site if and only if another ion, not necessarily of the same species, attempts to occupy the same site. Flux ratios and net fluxes are given as functions of the electrical potential, concentration ratios, and number of sites encountered in crossing the membrane. Quantitative comparisons with observations of Hodgkin and Keynes are presented.

  11. Ion implantation: an annotated bibliography

    International Nuclear Information System (INIS)

    Ting, R.N.; Subramanyam, K.

    1975-10-01

    Ion implantation is a technique for introducing controlled amounts of dopants into target substrates, and has been successfully used for the manufacture of silicon semiconductor devices. Ion implantation is superior to other methods of doping such as thermal diffusion and epitaxy, in view of its advantages such as high degree of control, flexibility, and amenability to automation. This annotated bibliography of 416 references consists of journal articles, books, and conference papers in English and foreign languages published during 1973-74, on all aspects of ion implantation including range distribution and concentration profile, channeling, radiation damage and annealing, compound semiconductors, structural and electrical characterization, applications, equipment and ion sources. Earlier bibliographies on ion implantation, and national and international conferences in which papers on ion implantation were presented have also been listed separately

  12. Influence of metal ions on pellet morphology and polygalacturonase synthesis by Aspergillus niger 3T5B8 Influência dos íons metálicos na morfologia do agregado e na síntese de poligalacturonase por Aspergillus niger 3T5B8

    Directory of Open Access Journals (Sweden)

    Sônia Couri

    2003-04-01

    Full Text Available The effects of cations addition on pellet morphology and polygalacturonase (PG synthesis by Aspergillus niger 3T5B8 were studied and compared with a control system. Fe(II, Cu(II, Zn(II and Mn(II were added to the fermentation medium separately, and also as combined groups of cations. The addition of Fe2+ and/or Zn2+ ions was significantly positive to the enzyme production. A positive effect in the biomass content, however, was only obtained when the same metal ions were added separately. On the other hand, Cu2+ and Mn2+ ions had almost no effect on these parameters. The morphology of the pellets was studied by image processing techniques. Small pellets with small cores were usually obtained when Fe2+ and Zn2+ ions were individually or collectively added to the medium. The pellets produced in media containing Fe2+ or Zn2+ ions were compact, while the ones produced in a medium containing both cations were considered diffuse. Autolysis of the core was observed for large control pellets, due to the deficient nutrient transfer to the interior of the pellet. The pellets obtained in a medium containing both Fe2+ and Zn2+ ions were high enzyme producers, probably due to a loose morphology, induced by the presence of combined groups of metal ions in the medium, favoring the nutrient transfer.O efeito da adição de cátions na morfologia do agregado e na síntese de poligalacturonase (PG por Aspergillus niger 3T5B8 foi estudado e comparado com um sistema controle. Fe(II, Cu(II, Zn(II and Mn(II foram adicionados ao meio de fermentação, tanto separadamente, como em grupos de cátions. A adição dos íons Fe2+ e/ou Zn2+ foi positivamente significante para a produção da enzima. Um efeito similar no teor de biomassa, contudo, só pode ser observado quando os mesmos íons foram adicionados isoladamente. Por outro lado, os íons Cu2+ e Mn2+ não afetaram significativamente estes parâmetros. Utilizando-se técnicas de processamento de imagens para o estudo

  13. Electrohydrodynamic emitters of ion beams

    International Nuclear Information System (INIS)

    Dudnikov, V.G.; Shabalin, A.L.

    1990-01-01

    Physical processes determining generation of ion beams with high emission current density in electrohydrodynamic emitters are considered. Electrohydrodynamic effects developing in ion emission features and kinetics of ion interaction in beams with high density are discussed. Factors determining the size of the emission zone, emission stability at high and low currents, cluster generation, increase of energy spread and decrease of brightness are analyzed. Problems on practical provision of stable EHD emitter functioning are considered. 94 refs.; 8 figs.; 1 tab

  14. Relativistic heavy-ion physics

    CERN Document Server

    Herrera Corral, G

    2010-01-01

    The study of relativistic heavy-ion collisions is an important part of the LHC research programme at CERN. This emerging field of research focuses on the study of matter under extreme conditions of temperature, density, and pressure. Here we present an introduction to the general aspects of relativistic heavy-ion physics. Afterwards we give an overview of the accelerator facility at CERN and then a quick look at the ALICE project as a dedicated experiment for heavy-ion collisions.

  15. Other applications of ion microbeams

    International Nuclear Information System (INIS)

    Cookson, J.A.

    1987-01-01

    The paper concerns the analytical and non-analytical applications of ion microbeams. The analytical applications considered include:-fusion research, environmental studies, ion implantations and criminology, and each is briefly discussed. Non-analytical applications in which nuclear microprobes have been used include:-thickness and uniformity measurements, energy loss radiography, channelling contrast, tomography, topography, ion implantation, and detector testing, and these are also discussed. (UK)

  16. Heavy ion medical accelerator, HIMAC

    International Nuclear Information System (INIS)

    Yamada, Satoru

    1993-01-01

    The heavy ion beam is undoutedly suitable for the cancer treatment. The supriority of the heavy ions over the conventional radiations including protons and neutrons comes mainly from physical characteristics of a heavy particle with multiple charges. A straggling angle due to a multiple Coulomb scattering process in a human body is small for heavy ions, and the small scattering angle results in a good dose localization in a transverse direction. An ionization ratio of the heavy ion beam makes a very sharp peak at the ends of their range. The height of the peak is higher for the heavier ions and shows excellent biomedical effects around Ne ions. In order to apply heavy ion beams to cancer treatment, Heavy Ion Medical Accelerator in Chiba (HIMAC) has been constructed at National Institute of Radiological Sciences. The accelerator complex consists of two ion sources, two successive linac tanks, a pair of synchrotron rings, a beam transport system and an irradiation system. An operation frequency is 100 MHz for two linacs, and the ion energy is 6.0 MeV/u at the output end of the linac. The other four experimental rooms are prepared for basic experiments. The synchrotron accelerates ions up to 800 MeV/u for a charge to mass ratio of 1/2. The long beam transport line provides two vertical beams in addition with two horizontal beams for the treatment. The three treatment rooms are prepared one of which is equipped with both horizontal and vertical beam lines. The whole facility will be open for all scientists who have interests in the heavy ion science as well as the biophysics. The conceptual design study of HIMAC started in 1984, and the construction of the accelerator complex was begun in March 1988. The beam acceleration tests of the injector system was successfully completed in March of this year, and tests of the whole system will be finished throughout this fyscal year. (author)

  17. A laser activated ion source

    International Nuclear Information System (INIS)

    Hughes, J.; Luther-Davies, B.; Hora, H.; Kelly, J.

    1978-01-01

    Apparatus for generating energetic ions of a target material from a cold plasma of the material is described. A pulsed laser beam is directed onto the target to produce the cold plasma. Laser beam pulses are short in relation to the collision time in the plasma. Non-linear elctrodynamic forces within the plasma act to accelerate and eject ions from the plasma. The apparatus can be used to separate ions of isotopes of an element

  18. Cornell electron beam ion source

    International Nuclear Information System (INIS)

    Kostroun, V.O.; Ghanbari, E.; Beebe, E.N.; Janson, S.W.

    1981-01-01

    An electron beam ion source (EBIS) for the production of low energy, multiply charged ion beams to be used in atomic physics experiments has been designed and constructed. An external high perveance electron gun is used to launch the electron beam into a conventional solenoid. Novel features of the design include a distributed sputter ion pump to create the ultrahigh vacuum environment in the ionization region of the source and microprocessor control of the axial trap voltage supplies

  19. Ion induced Auger spectroscopy

    International Nuclear Information System (INIS)

    Thomas, E.W.; Legg, K.O.; Metz, W.A.

    1980-01-01

    Auger electron spectra are induced by impact of heavy ions (e.g. Ar + ) on surfaces; it has been suggested that analysis of such spectra would be a useful technique for surface analysis. We have examined the Auger spectra for various projectile-target combinations and present as representative data the spectra for 100 keV Ar + impact on Al, Cr, Mn, Fe and Co. For a projectile incident on a species of higher nuclear charge the spectrum is dominated by Auger lines from the projectile, broadened considerably by the Doppler effect due to the projectile's motion. The spectra are not characteristic of the target and therefore offer no opportunity for surface analysis. For a projectile incident on a target of lower nuclear charge the spectrum is that of the target species but the spectrum is consistent with the source being sputtered excited atoms; the Auger electrons do not come from the surface. We conclude that the ion induced Auger spectra are in general not a convenient method for surface analysis. (orig.)

  20. Electrically switched ion exchange

    Energy Technology Data Exchange (ETDEWEB)

    Lilga, M.A. [Pacific Northwest National Lab., Richland, WA (United States); Schwartz, D.T.; Genders, D.

    1997-10-01

    A variety of waste types containing radioactive {sup 137}Cs are found throughout the DOE complex. These waste types include water in reactor cooling basins, radioactive high-level waste (HLW) in underground storage tanks, and groundwater. Safety and regulatory requirements and economics require the removal of radiocesium before these wastes can be permanently disposed of. Electrically Switched Ion Exchange (ESIX) is an approach for radioactive cesium separation that combines IX and electrochemistry to provide a selective, reversible, and economic separation method that also produces little or no secondary waste. In the ESIX process, an electroactive IX film is deposited electrochemically onto a high-surface area electrode, and ion uptake and elution are controlled directly by modulating the potential of the film. For cesium, the electroactive films under investigation are ferrocyanides, which are well known to have high selectivities for cesium in concentrated sodium solutions. When a cathode potential is applied to the film, Fe{sup +3} is reduced to the Fe{sup +2} state, and a cation must be intercalated into the film to maintain charge neutrality (i.e., Cs{sup +} is loaded). Conversely, if an anodic potential is applied, a cation must be released from the film (i.e., Cs{sup +} is unloaded). Therefore, to load the film with cesium, the film is simply reduced; to unload cesium, the film is oxidized.