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Sample records for para calcular dose

  1. Descapitalización de las tasas efectivas para calcular el interés simple

    OpenAIRE

    Avelino Sánchez, Esteban Marino; Cerna Maguiña, Héctor Félix

    2014-01-01

    La tasa de interés nominal, se utiliza normalmente para calcular interés simple e interés compuesto (bajo ciertos supuestos o condiciones). En sentido contrario, utilizar la tasa efectiva para calcular el interés simple no es usual. Sin embargo, en el Perú se utiliza para calcular interés legal laboral; entonces el problema consiste en descapitalizar la tasa de interés legal efectiva, como su factor acumulado, a través de experimentos de cálculo en Excel, observar las propiedades de la potenc...

  2. Relojes de agua, una oportunidad para calcular integrales

    OpenAIRE

    Thiabut, Elena

    2007-01-01

    Este artículo propone una investigación sobre clepsidras (relojes de agua) para alumnos de 2º de bachillerato. El cálculo integral será la clave para descubrir cómo la geometría de los recipientes condiciona el funcionamiento de estos mecanismos milenarios.

  3. Programa computacional para calcular a potência requerida de máquinas e implementos agrícolas

    OpenAIRE

    Pablo Pereira Corrêa Klaver; Ricardo Ferreira Garcia; José Francisco Sá Vasconcelos Júnior; Delorme Corrêa Junior; Wellington Gonzaga Vale

    2013-01-01

    O uso de programas computacionais no setor agrícola permite atingir objetivos específicos na área. Dentre esses, um dos mais complexos é a seleção adequada de máquinas e implementos agrícolas visando à otimização de operações agrícolas, devido, principalmente, à grande variedade de equipamentos existentes no mercado e a gama de tarefas e situações de trabalho que estas são submetidas no campo. O objetivo deste trabalho foi desenvolver um programa computacional para calcular a potência requeri...

  4. Programa computacional para calcular a potência requerida de máquinas e implementos agrícolas

    Directory of Open Access Journals (Sweden)

    Pablo Pereira Corrêa Klaver

    2013-12-01

    Full Text Available O uso de programas computacionais no setor agrícola permite atingir objetivos específicos na área. Dentre esses, um dos mais complexos é a seleção adequada de máquinas e implementos agrícolas visando à otimização de operações agrícolas, devido, principalmente, à grande variedade de equipamentos existentes no mercado e a gama de tarefas e situações de trabalho que estas são submetidas no campo. O objetivo deste trabalho foi desenvolver um programa computacional para calcular a potência requerida de máquinas e implementos agrícolas normalmente utilizados na condução de operações de campo, desde o preparo do solo até as operações de implantação de culturas. Desenvolvido em linguagem PHP, o programa computacional baseia-se na norma ASAE D497.4 - Agricultural Machinery Management Data como referência para desenvolvimento de cálculos. A partir do programa desenvolvido, tornou-se possível a execução de tarefas para cálculos de avaliação da demanda de potência de máquinas e implementos agrícolas de forma simplificada pela internet.

  5. Herramienta web para calcular el impacto radiologico asociado al transporte de residuos radiactivos al ATC

    OpenAIRE

    Calleja Rubio, Jose Antonio; Gutierrez Martin, Fernando; Colón Hernández, Cristobal

    2012-01-01

    Técnicos de TECNATOM, S.A. e Investigadores de la (UPM), han desarrollado un programa para analizar la logística y los impactos potenciales del transporte por carretera de materiales radiactivos en España. El transporte de materiales radiactivos es un tema de renovado interés en nuestro país debido a la creciente movilidad que cabe esperar, sobre todo tras la entrada en operación del almacén temporal centralizado (ATC) previsto para los próximos años. Este almacén está destinado a resi...

  6. A method for determining an indicator of effective dose calculation due to inhalation of Radon and its progeny from in vivo measurements; Um metodo para determinar um indicador para calcular dose efetiva devida a inalacao de Radonio e seus descendentes utilizando medicoes in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Estrada, Julio Jose da Silva

    1994-07-01

    Direct measurement of the absolved dose to lung tissue from inhalation of radon and its progeny is not possible and must be calculated using dosimetric models, taking into consideration the several parameters upon which the dose calculation depends. To asses the dose due to inhalation of radon and its progeny, it is necessary to estimate the cumulative exposure. Historically, this has been done using WLM values estimated with measurements of radon concentration in air. The radon concentration in air varies significantly, however, in space with time, and the exposed individual is also constantly moving around. This makes it almost impossible to obtain a precise estimate of an individual's inhalation exposure. This work describes a pilot study to calculate lung dose from the deposition of radon progeny, via estimates of cumulative exposure derived from in vivo measurements of {sup 210} Pb, in subjects exposed to above-average radon and its progeny concentrations in their home environments. The measurements were performed in a whole body counter. With this technique, the exposed individuals become, in affect, their own samplers and dosimeters and the estimate of cumulative exposure is not affected by the variation of the atmospheric concentration of radon and its progeny in time and space. Forty individuals identified as living in homes with radon levels ranging from about 740 Bq/m{sup 3} to 150.000 Bq/m{sup 3} were measured. Also, additional 34 measurements were made on personnel from NYUMC/NIEM who live in a residential area surrounding the laboratory in which the levels of radon have been shown to be at below average values. To realize these measurements a methodology was developed to determine the subject's background, using a head phantom made with a cubic plastic container containing known amounts of potassium and calcium dissolved in four liters of water. The effective doses calculated from the in vivo measurements are compared to effective doses estimated, for

  7. A method for determining an indicator of effective dose calculation due to inhalation of Radon and its progeny from in vivo measurements; Um metodo para determinar um indicador para calcular dose efetiva devida a inalacao de Radonio e seus descendentes utilizando medicoes in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Estrada, Julio Jose da Silva

    1994-07-01

    Direct measurement of the absolved dose to lung tissue from inhalation of radon and its progeny is not possible and must be calculated using dosimetric models, taking into consideration the several parameters upon which the dose calculation depends. To asses the dose due to inhalation of radon and its progeny, it is necessary to estimate the cumulative exposure. Historically, this has been done using WLM values estimated with measurements of radon concentration in air. The radon concentration in air varies significantly, however, in space with time, and the exposed individual is also constantly moving around. This makes it almost impossible to obtain a precise estimate of an individual's inhalation exposure. This work describes a pilot study to calculate lung dose from the deposition of radon progeny, via estimates of cumulative exposure derived from in vivo measurements of {sup 210} Pb, in subjects exposed to above-average radon and its progeny concentrations in their home environments. The measurements were performed in a whole body counter. With this technique, the exposed individuals become, in affect, their own samplers and dosimeters and the estimate of cumulative exposure is not affected by the variation of the atmospheric concentration of radon and its progeny in time and space. Forty individuals identified as living in homes with radon levels ranging from about 740 Bq/m{sup 3} to 150.000 Bq/m{sup 3} were measured. Also, additional 34 measurements were made on personnel from NYUMC/NIEM who live in a residential area surrounding the laboratory in which the levels of radon have been shown to be at below average values. To realize these measurements a methodology was developed to determine the subject's background, using a head phantom made with a cubic plastic container containing known amounts of potassium and calcium dissolved in four liters of water. The effective doses calculated from the in vivo measurements are compared to effective doses

  8. Novo método para calcular o diâmetro médio de agregados de solos

    Directory of Open Access Journals (Sweden)

    Q. de JONG van LIER

    1997-12-01

    Full Text Available Ao calcular o diâmetro médio ponderado (DMP ou o diâmetro médio geométrico (DMG de uma amostra de solo, ponderam-se o diâmetro médio aritmético (no caso do DMP ou o logarítmico (no caso do DMG de cada classe pela massa de agregados nela retida. A média aritmética de cada classe, multiplicada pela massa de agregados retidos na respectiva classe, apenas é correta, quando ocorrer uma distribuição simétrica de massa de agregados dentro de cada classe, o que é muito pouco provável. O objetivo deste trabalho, desenvolvido no final de 1996 no Departamento de Solos da UFRGS, Porto Alegre, é propor um novo método para o cálculo do diâmetro médio dos agregados, presumindo ser a distribuição dentro de cada classe semelhante à distribuição dos agregados de toda a amostra. Essa proposta pressupõe ser o diâmetro médio da classe mais bem estimado por aquele diâmetro que divide os agregados contidos nela em duas partes de massa igual. Para isso foi apresentado um procedimento de cálculo, e o diâmetro médio assim encontrado foi denominado "diâmetro médio ajustado" (DMA. Para testar o método, utilizaram-se dados existentes de vários solos, condições de manejo do solo e rotações de culturas. Considerando os resultados, justifica-se a utilização do parâmetro DMA no lugar do DMP ou DMG, por representar mais corretamente o diâmetro médio dos agregados de uma amostra de solo.

  9. Aplicación de un sistema para calcular déficit de fuerza resistencia en atletas de fondo

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    Eduardo Valcarce Merayo

    2012-12-01

    Full Text Available Con este estudio se pretende determinar la evolución en la longitud de zancada en atletas de resistencia que no periodizan el entrenamiento de fuerza. En el estudio participaron 6 sujetos varones atletas de resistencia de 31 años (± 4,6 años, con una experiencia deportiva de 14 años (± 4 años que realizaron un entrenamiento interválico donde se determinó la velocidad, frecuencia y amplitud de zancada media de cada repetición a partir de la zona de grabación. El porcentaje de pérdida de amplitud de zancada, medido a través del índice SLS (stride loss strength comparó dicha pérdida de longitud de zancada (cm/m ∙ s–1 entre grupos de repeticiones: Grupo 1 (repeticiones 1-7, Grupo 2 (repeticiones 8-14, Grupo 3 (repeticiones 15-21 observándose un descenso significativo en el índice SLS entre Grupo 2 y el Grupo 3 (p = 0,05. Concluyendo que este indicador es una herramienta específica para determinar posibles déficits de fuerza en este tipo de deportistas, ayudando a entrenadores y atletas que quieran evaluar los niveles de fuerza resistencia en una medición de campo.

  10. Uso de integración según Gauss para calcular la fotosíntesis en modelos de Simulación de Crecimiento de Cultivos.

    Directory of Open Access Journals (Sweden)

    Donatus M. Jansen

    2012-03-01

    Full Text Available Tres modelos dinámicos y explicativos para calcular la fotosíntesis de cultivos son comparados. Los modelos difieren en la forma de integrar numéricamente la fotosíntesis sobre el tiempo y el dosel: el modelo de Euler usa pasos pequeños y fijos, y los modelos de Goudriaan y adaptado lo hacen con el método de Gauss, seleccionando puntos claves en el intervalo de integración del tiempo y del dosel. El modelo adaptado incluye el efecto del cambio de la temperatura diurna en la fotosíntesis y tiene flexible el número de puntos para la evaluación en el tiempo, cuando el modelo de Goudriaan asume que el efecto de la temperatura es constante y usa tres puntos de evaluación en el tiempo. El comportamiento de los modelos de Goudriaan y adaptado es relacionado al del modelo de Euler por dos condiciones climatologicas (tropical y templado, tres tipos de distribución de la radiación en el día: simétrico, simétrico con picos e intensidad de radiación en la mañana dos veces más grande que en la tarde. Los resultados del modelo adaptado en general tiene una relación ligeramente mejor al modelo de Euler comparado con el modelo de Goudriaan, sugiriendo que el uso de este modelo, con cinco puntos de evaluación en el tiempo, da buenos resultados.

  11. Cuestionario para calcular la Huella Ecológica de estudiantes universitarios mexicanos y su aplicación en el Campus Zaragoza de la Universidad Nacional

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    José Manuel Ibarra-Cisneros

    2014-01-01

    Full Text Available En este trabajo se desarrolló un cuestionario de 30 preguntas para calcular la huella ecológica (HE de estudiantes universitarios mexicanos, considerando el estilo de vida y el patrón de consumo propios de la cultura mexicana. Primero, se obtuvo de anuarios estadísticos la productividad promedio (en ton/ha/año, de los bienes agropecuarios y pesqueros más demandados, y de papel de cuadernos escolares, con la finalidad de determinar la superficie que se requiere para producir el consumo anual del mexicano promedio, por tipo de bien; también, se calculó el área promedio para absorber el dióxido de carbono generado por el consumo de energía directo (debido al uso de transportes, de equipos electrónicos, de agua caliente para ducharse y de agua potable de empleo cotidiano, e indirecto (producción, distribución y comercialización de productos. Posteriormente, se transformaron las superficies obtenidas a hectáreas globales (hag mediante factores de conversión y se aplicó el cuestionario a 125 alumnos universitarios obteniendo una HE de 1.48 hag, con resultado de mayor impacto ambiental individual al rubro de alimentos (0.42 hag por el consumo de cárnicos, seguido del uso de energía (0.35 hag, principalmente por utilizar gas LP en la ducha cotidiana. Esta HE está dentro de los límites de sustentabilidad global (< 1.61 hag. No hubo diferencias significativas debidas al nivel de estudios, edad o sexo de la muestra. Finalmente, se concluye que el instrumento desarrollado es coherente con los resultados obtenidos de cuestionarios disponibles en línea y elaborados en países de alto nivel de consumo de bienes y servicios y que aquí se presenta la primera calculadora de huella ecológica que toma en cuenta la idiosincrasia mexicana.

  12. UN PROGRAMA PARA CALCULAR LAS REPRESENTACIONES IRREDUCIBLES DE SN, EN LA FORMA SEMINORMAL DE YOUNG 1 MATEMÁTICA COMPUTACIONAL COMO APOYO A LA DOCENCIA

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    Álvaro Duque S.J.

    2002-06-01

    Full Text Available Las matrices de las representaciones irreducibles de un grupo G se usan para el cómputo de la Transformada Generalizada de Fourier de una función definida en G. Existen muchas otras aplicaciones para las representaciones irreducibles de un grupo. Nosotros elaborarnos un software que calcula las matrices de las representacionesirreducibles del grupo simétrico en la forma serninormal de Young. Este programa corre en el Sistema Algebraico Computacional CoCoA.

  13. FRAX TM: un nuevo instrumento para calcular el riesgo absoluto de fracturas a 10 años FRAX TM: A new instrument for calculating 10-year absolute fracture risk

    Directory of Open Access Journals (Sweden)

    Haraldo Claus-Hermberg

    2009-10-01

    Full Text Available La eficacia de nuevos agentes farmacológicos para la prevención de fracturas osteoporóticas y la decisión de intervención con la misma finalidad en la práctica clínica han sido guiadas por la evaluación de la densitometría ósea (DMO. Sin embargo, reconociendo la naturaleza multifactorial de ese desenlace, recientemente se dio a conocer el calculador Fracture Risk Assessment Tool (FRAX™ que persiguiendo los mismos objetivos de modelos previos, integra y combina varios de esos factores ponderadamente para estimar el riesgo absoluto de fractura de cadera o un combinado de fracturas osteoporóticas para los siguientes 10 años. El mismo sería ajustable a cualquier país incorporando al modelo la incidencia de fractura de cadera y las expectativas de vida edad- y sexo-específicas para la población a que pertenece el individuo. Este instrumento es presentado como un nuevo paradigma para ayudar en la toma de decisiones terapéuticas, especialmente farmacológicas. En la presente revisión se discuten algunas de sus características, como ser: la pretendida aplicabilidad a poblaciones de distintos países, la conveniencia de utilizar el riesgo absoluto a 10 años para todo el espectro etario de interés y si la eficacia de los tratamientos farmacológicos para la prevención de fracturas óseas en pacientes osteoporóticos podrá comprobarse también en pacientes seleccionados para tratamiento en base a este modelo. Finalmente, se llama la atención sobre el hecho de que aún no están claramente determinados los umbrales de riesgo orientadores para la toma de decisiones, los que obviamente tendrán un relevante impacto en el número de pacientes pasibles de tratamiento.The efficacy of new pharmacological agents for the prevention of osteoporotic fractures and the clinical decision to intervene with that purpose in daily medical practice have been guided by the evaluation of bone mineral density (BMD. However, given the multifactorial

  14. Apresentação de um programa de computador para calcular a discrepância de tamanho dentário de Bolton Presentation of a computer program to calculate the Bolton’s tooth size discrepancy

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    Adriano Francisco de Lucca Facholli

    2006-04-01

    Full Text Available O diagnóstico da discrepância de tamanho dentário de Bolton é de fundamental importância para a boa finalização do tratamento ortodôntico. Por meio da medição dos dentes, com o auxílio de um paquímetro digital e a inserção dos valores no programa de computador desenvolvido e apresentado pelos autores, o trabalho do ortodontista fica mais simples, pois não é necessário realizar nenhum cálculo matemático ou auxiliar-se de nenhuma tabela de valores, eliminando-se a probabilidade de erros. Além disso, o programa apresenta a localização da discrepância por segmento - total, anterior e posterior - e individual - por elemento dentário, permitindo assim maior precisão na planificação das estratégias para a resolução dos problemas, caminhando para um tratamento ortodôntico de sucesso.The diagnosis of the Bolton’s Tooth Size Discrepancy is of fundamental importance for the good orthodontics finalization. Through the measurement of the teeth with the aid of a digital caliper and the insert of the values in the computer program developed by the authors and which that it will be presented in this article, the orthodontist’s work is simpler, because it is not necessary to accomplish any mathematical calculation or to aid of any table of values, eliminating the probability of mistakes. Besides, the program presents the location of the discrepancy for segment - overall, anterior and posterior - and individual - for dental element, allowing larger precision in the planning of the strategies for the resolution of the problems and walking for a success orthodontic treatment.

  15. Nuevas orientaciones para calcular la profundidad efectiva de la capa endurecida en engranajes de acero cementado // New orientations to calculate the effective depth of the layer hardened in engagements of cemented steel

    OpenAIRE

    G. González Rey

    1999-01-01

    Se exponen y discuten los inconvenientes de las clásicas y conocidas recomendaciones para decidir el espesor efectivo de capaendurecida en los dientes cementados de engranajes cilíndricos y cónicos. Además, se exponen los recientes trabajo realizados porISO TC60/WG 14 en la normalización de la profundidad efectiva de capa cementada, tomando como base las propuestas alemana yestadounidense. Es verificada mediante 5 ejemplos la aplicabilidad del estado actual de las recomendaciones de profundid...

  16. ¿CÓMO CALCULAR LOS COSTOS MEDIOAMBIENTALES? CASO: EMPRESA GRÁFICA DE CIENFUEGOS

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    Keitel, Becerra

    Full Text Available El mundo necesita urgentemente que se proteja el medio ambiente, muchas empresas y organizaciones destinan grandes recursos para lograr ese fin y lograr un Desarrollo Sostenible como máxima a alcanzar por cualquier país u organización. Se hace entonces imprescindible determinar cuánto le dedican las Empresas al medio ambiente, teniendo en cuenta que las Entidades tienen un contrato implícito con la sociedad y el medio, producto de los recursos que utiliza y los desechos y desperdicios que vierte, es por eso que se necesitan calcular y registrar los costos medioambientales por productos, para enriquecer la gestión medioambiental de la entidad y favorecer de esta manera una excelente toma de decisiones. La siguiente investigación busca un procedimiento que permita dar solución a esta problemática, logrando su conformación con el uso de diversas técnicas dentro de las que se destacan las listas de chequeos medioambientales y el ciclo de vida del producto, que permite además poder conocer por separado como cada proceso y producto impacta en el medioambiente.

  17. Helicobacter pylori infection in patients with calcular cholecystitis: a hospital based study

    International Nuclear Information System (INIS)

    Hussain, A.; Haider, I.Z.; Ahmad, S.

    2011-01-01

    Background: Helicobacter pylori, a gram negative bacillus has been recognised as a public health problem and approximately half of the world population has H. pylori infection causes chronic gastritis, peptic ulcer disease and gastric malignancies. Objective of this study was to determine the frequency of H. pylori infection in patients of chronic calcular cholecystitis. Methods: This cross-sectional descriptive study was conducted at Liaquat University Hospital, Hyderabad, Pakistan from April 2010 to September 2010. All patients with history of gallstone presented with acute abdominal pain, dyspepsia, bloating and epigastric discomfort and diagnosed as calcular cholecystitis were further evaluated for the detection of H. pylori by serology and histopathology. Frequency and percentage of H. pylori infection in patients with calcular cholecystitis was calculated. Result: Total 100 patients of cholelithiasis underwent laparoscopic cholecystectomy were recruited. The pain in upper right part of the abdomen was observed in all 100 patients, fever in 75%, nausea and vomiting in 68%, loss of appetite in 45%, feeling of tiredness or weakness in 22%, headache in 38%, chills in 52%, backache in 58%, pain under the right shoulder in 45%, heartburn in 67%, belching in 54%, indigestion in 80%, dyspepsia in 90%, bloating in 88%, and epigastric discomfort in 85% patients. Eighty-two percent patients had family history of gallstones. The mean age of overall study population was 48.72 +- 8.78 years and mean age of H. pylori infected calcular cholecystitis patients was 47.98 +- 5.43 years in male and 48.76 +- 6.68 years in females. The H. pylori infection was identified in 55% patients with calcular cholecystitis, of which 32.7% were males and 67.3% were females (p=0.03, statistically significant). Majority of females (60%) had =40 U/ml antibody titre (p=0.917, non-significant). Conclusion: A possible relationship was identified between Helicobacter pylori and calcular

  18. Factores geométricos para calcular a flexión engranajes cilíndricos rectos asimétricos con perfil evolvente - trocoide // Geometric factors for determining the bending strength of asymmetric spur gears with profile teeth involute-trochoid

    Directory of Open Access Journals (Sweden)

    Javier Antonio Cárdenas-Oliveros

    2011-08-01

    Full Text Available ResumenSe propone un modo de cálculo analítico basado en el análisis del modelo gráfico del diente de losengranajes cilíndricos rectos asimétricos con perfil de evolvente y trocoide, que permite obtener lasvariables asociadas a la determinación de los factores geométricos de forma y de resistencia,necesarios para el cálculo de la resistencia a flexión. Este tipo de procedimiento es empleado porprimera vez para obtener el parámetro geométrico de forma. Además, se establecen losfundamentos que aportan la determinación del parámetro geométrico de resistencia J para estostipos de engranajes. Los resultados de la presente investigación permiten determinar el esfuerzomáximo a la flexión a partir de los coeficientes geométricos de forma y resistencia, se construyeronecuaciones, tablas y diagramas representativos de estos parámetros. La aplicación práctica de esteenfoque de solución, permite la generalización del mismo en los mecanismos de transmisión conengranajes cilíndricos de dientes rectos asimétricos de perfil evolvente trocoide..Palabras claves: engranaje recto asimétrico, factores geométricos, resistencia a la flexión, CAD/CAE.__________________________________________________________________________AbstractIn this paper an analytical method of calculus based on computer analysis of the spur gears graphicmodel with asymmetric teeth of involute profile and trochoid is proposed, it was estimated formgeometry factor and bending strength by a direct calculus method. This procedure is first used toobtain form geometry factor. Furthermore, the factor J foundation for these types of gears wasestablished. The results of this research determinates analytically the maximum bending stress, usingthe form geometry factor and bending geometry factor, built equations, tables and diagramsrepresenting these parameters. The practical application of this solution approach allows thegeneralization of it in use in transmission

  19. ¿Cómo transformar los modelos input-output para calcular multiplicadores netos?

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    Pereira López, Xesús

    2015-11-01

    Full Text Available The aim of this paper is to calculate net input-output multipliers using different adjustments on the Leontief inverse, without simply removing part of its elements. Moreover, in order to increase the accuracy of the estimation, a standardization of the inverse is offered. The empirical application is presented for the Galician economy, based on the year 2011. A comparison between the proposed extended methodology and the traditional I-O techniques is shown, throughout the results obtained in the estimation of the backward and forward sectoral linkages. With this new approach, some of the conventional key sectors will not appear as such, like the case of the construction sector.

  20. Dose vocal em professores: correlação com a presença de disfonia

    OpenAIRE

    Gama, Ana Cristina Côrtes; Santos, Juliana Nunes; Pedra, Elisângela de Fátima Pereira; Rabelo, Alessandra Terra Vasconcelos; Magalhães, Max de Castro; Casas, Estevam Barbosa de Las

    2016-01-01

    RESUMO Professores são profissionais com alta prevalência de disfonia, para a qual os principais fatores de risco são as longas jornadas de trabalho em salas de aula com presença de ruído ambiental. O objetivo da pesquisa foi calcular o tempo de fonação e a dose cíclica de professoras com disfonia e de professoras sem alteração de voz durante a atividade letiva. Para o estudo, dois grupos foram analisados: cinco professoras com disfonia funcional constituíram o grupo de professores disfônicos...

  1. Dose coefficients for public exposition; Coeficientes de dose para exposicao ao publico

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-01

    This Regulation refers to the requirements of the Regulation CNEN-NN.3.01 'Basic Guidelines for Radiation Protection', to be applied to the dose calculus with the objective of verification according to the limits and restrictions of dose and reference levels of the public individuals, expressed in its section 5

  2. High doses of carbamazepine for refractory partial epilepsy Altas doses de carbamazepina para epilepsia parcial refratária

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    Cristiana Borges Pereira

    1996-03-01

    Full Text Available Forty-eight patients with partial seizures were analysed during treatment with 1200 mg/d or more of carbamazepine (CBZ. Thirty-three were on monotherapy and fifteen on polytherapy. The other drugs were kept unchanged in the patients on polytherapy. The dose of CBZ was increased if no control was observed and the patient had no side effects. The doses used ranged between 1200 and 1900 mg/day (1200 mg/day, n=18; 1300mg/day, n=1; 1400 mg/day, n=7; 1600 mg/day, n=9; 1700 mg/day, n=4; 1800 mg/day, n=8; 1900 mg/day, n=1. Anticonvulsant plasma levels were taken to confirm patient compliance. The average plasma level was 9.6 ug/mL. The period of follow up varied from 3 to 96 months (M=25.6. Seizure's control was observed in 7 (14.48% patients taking 1200 mg/day and in 2 (4.16% patients taking 1400 mg/day of CBZ. Thirty-nine patients did not show any control (81.21%. Ten patients (20.81% had signs of intoxication. When patients have no improvement with 1400 mg/day, it is difficult to obtain any control despite the use of higher doses of CBZ, which frequently expose the patient to significant side effects.Foram analisados 48 pacientes epilépticos com crises parciais que faziam uso de carbamazepina (CBZ em doses iguais ou superiores a 1200 mg por dia. Trinta e três estavam em monoterapia e 15 em politerapia. As outras medicações foram mantidas constantes durante a manipulação da dose de CBZ nos pacientes em politerapia. O critério utilizado para o aumento da dose de CBZ foi a falta de controle clínico e a ausência de efeitos colaterais (independente da dosagem sérica. A dose máxima variou de 1200 a 1900 mg/dia (1200 mg, n=18; 1300 mg/dia, n=1; 1400 mg/dia, n=7; 1600 mg/dia, n=9; 1700 mg/dia, n=4; 1800 mg/dia, n=8 ; 1900 mg/dia, n=1. Dosagens séricas de anticonvulsivantes eram utilizadas no sentido de confirmar a aderência ao tratamento. A média das dosagens disponíveis foi de 9,6 ug/mL. O tempo de seguimento variou de 3 a 96 meses (M=25

  3. Testicular shield for para-aortic radiotherapy and estimation of gonad doses

    OpenAIRE

    Ravichandran, R.; Binukumar, J. P.; Kannadhasan, S.; Shariff, M. H.; Ghamrawy, Kamal El

    2008-01-01

    For radiotherapy of para-aortic and abdominal regions in male patients, gonads are to be protected to receive less than 2% of the prescribed dose. A testicular shield was fabricated for abdominal radiotherapy with 15 MV X-rays ((Clinac 2300 CD, Varian AG) with low melting point alloy (Cerroband). The dimensions of the testicular shield were 6.5 cm diameter and 3.5 cm depth with 1.5 cm wall thickness. During treatment, this shield was held in position by a rectangular sponge and Styrofo...

  4. Testicular shield for para-aortic radiotherapy and estimation of gonad doses.

    Science.gov (United States)

    Ravichandran, R; Binukumar, J P; Kannadhasan, S; Shariff, M H; Ghamrawy, Kamal El

    2008-10-01

    For radiotherapy of para-aortic and abdominal regions in male patients, gonads are to be protected to receive less than 2% of the prescribed dose. A testicular shield was fabricated for abdominal radiotherapy with 15 MV X-rays ((Clinac 2300 CD, Varian AG) with low melting point alloy (Cerroband). The dimensions of the testicular shield were 6.5 cm diameter and 3.5 cm depth with 1.5 cm wall thickness. During treatment, this shield was held in position by a rectangular sponge and Styrofoam support. Phantom measurement was carried out with a humanoid phantom and a 0.6 cc ion chamber. The mean energy of the scattered photon was calculated for single scattering at selected distances from the beam edge and with different field dimensions. One patient received radiotherapy with an inverted Y field and gonad doses were estimated using calibrated thermo-luminescent detector (TLD) chips. Measured doses with the ion chamber were 7.1 and 3.5% of the mid-plane doses without a shield at 3 and 7.5 cm off-field respectively. These values decreased to 4.6 and 1.7% with the bottom shield alone, and to 1.7 and 0.8% with both bottom and top shields covering the ion chamber. The measured doses at the gonads during the patient's treatment were 0.5-0.92% for the AP field (0.74 +/- 0.17%, n = 5) and 0.5-1.2% for the PA field (0.88 +/- 0.24%, n = 5). The dose received by the testis for the full course of treatment was 32 cGy (0.8%) for a total mid-plane dose of 40 Gy. The first-scatter energy estimated at the gonads is around 1.14 MeV for a primary beam of 15 MV for a long axis dimension of 37 cm of primary field. During the patient's treatment, the estimated absorbed doses at the gonads were comparable with reported values in similar treatments. The testicular shield reported in this study is of light weight and could be used conveniently in treatments of abdominal fields.

  5. Testicular shield for para-aortic radiotherapy and estimation of gonad doses

    Directory of Open Access Journals (Sweden)

    Ravichandran R

    2008-01-01

    Full Text Available For radiotherapy of para-aortic and abdominal regions in male patients, gonads are to be protected to receive less than 2% of the prescribed dose. A testicular shield was fabricated for abdominal radiotherapy with 15 MV X-rays ((Clinac 2300 CD, Varian AG with low melting point alloy (Cerroband. The dimensions of the testicular shield were 6.5 cm diameter and 3.5 cm depth with 1.5 cm wall thickness. During treatment, this shield was held in position by a rectangular sponge and Styrofoam support. Phantom measurement was carried out with a humanoid phantom and a 0.6 cc ion chamber. The mean energy of the scattered photon was calculated for single scattering at selected distances from the beam edge and with different field dimensions. One patient received radiotherapy with an inverted Y field and gonad doses were estimated using calibrated thermo-luminescent detector (TLD chips. Measured doses with the ion chamber were 7.1 and 3.5% of the mid-plane doses without a shield at 3 and 7.5 cm off-field respectively. These values decreased to 4.6 and 1.7% with the bottom shield alone, and to 1.7 and 0.8% with both bottom and top shields covering the ion chamber. The measured doses at the gonads during the patient′s treatment were 0.5-0.92% for the AP field (0.74 ± 0.17%, n = 5 and 0.5-1.2% for the PA field (0.88 ± 0.24%, n = 5. The dose received by the testis for the full course of treatment was 32 cGy (0.8% for a total mid-plane dose of 40 Gy. The first-scatter energy estimated at the gonads is around 1.14 MeV for a primary beam of 15 MV for a long axis dimension of 37 cm of primary field. During the patient′s treatment, the estimated absorbed doses at the gonads were comparable with reported values in similar treatments. The testicular shield reported in this study is of light weight and could be used conveniently in treatments of abdominal fields.

  6. Fundamentación matemática de un software para calcular valores regionales de variables respiratorias

    Directory of Open Access Journals (Sweden)

    Antonio Barber Gutiérrez

    1996-12-01

    Full Text Available Por el interés de conocer los valores regionales de las variables respiratorias más útiles en clínica, se presenta la fundamentación matemática de un software que cuantifica imágenes pulmonares obtenidas en gamma-cámara. La distribución del isótopo se convierte en 16 valores regionales de la función pulmonar. El software evalúa las imágenes partiendo de la relación actividad del isótopo contra tiempo y la incorporación de los datos adicionales siguientes: 1. CRF (capacidad residual funcional del pulmón; 2. comienzo de la inyección radiactiva (t o; 3. gasto cardíaco (GC; 4. frecuencia del pulso (f 5. presión barométrica (P B; 6. fracción de oxígeno atmosférico (F IO 2. En el trabajo se identifican las siglas médicas usadas y se da una introducción fisiológica sobre cada variable respiratoria.As a result of the existing interest for knowing the regional values of the most useful respiratory variables in clinics, it is presented the mathematical foundation of a software that quantifies pulmonary images obtained in gamma-camera. The isotope distribution becomes into 16 regional values of the pulmonary function. The software evaluates the images starting from the relation isotope activity against time, and the incorporation of the following additional data: 1, FRC (functional residual capacity of the lung; 2. beggining of radioactive injection (t o; 3. cardiac output (CO; 4. pulse frequency (f; 5. barometric pressure (Pb ; 6. atmospheric oxygen fraction (F10 2. The medical acronyms used are identified in this paper and a physiological introduction on every respiratory variable is given.

  7. Eye dose measurements using conventional and rare-earth screens during tomography of the para-nasal sinuses

    International Nuclear Information System (INIS)

    Eddleston, B.; Moores, B.M.; Walker, A.

    1977-01-01

    Eye dose measurements have been performed when using medium speed conventional and rare-earth screen-film combinations during tomography of the para-nasal sinuses. The measurements showed that using conventional intensifying screens with the A.P. view a total eye dose of about 20 rad may be given during an examination. This eye dose can be reduced by 98% using the P.A. position. If rare-earth screen/film combinations were employed the eye dose measured in the A.P. view was reduced by 75% of that obtained with conventional screens without detectable loss of image quality. A total eye dose reduction of about 99.5% was measured in the P.A. view with the rare-earth systems. (author)

  8. ?`Es necesario calcular detalladamente funciones de partición atómicas?

    Science.gov (United States)

    Milone, L. A.; Merlo, D. C.

    Basándonos en extensos y precisos cómputos de funciones de partición realizados por nosotros para distintos átomos, se muestra que en el cálculo u obtención de ciertas magnitudes (notablemente la presión electrónica, la abundancia de un elemento deducida a partir de un estado fuertemente ionizado, etc.) el error porcentual que se comete es pequeño (inferior a 1 %) si se adopta, como valor de la función de partición, el peso estadístico del término correspondiente al estado fundamental del átomo. Esta notable simplificación acelera el cálculo, por ejemplo, de un modelo de atmósfera estelar, sin disminuir la precisión de los resultados.

  9. Manual method for dose calculation in gynecologic brachytherapy; Metodo manual para o calculo de doses em braquiterapia ginecologica

    Energy Technology Data Exchange (ETDEWEB)

    Vianello, Elizabeth A.; Almeida, Carlos E. de [Instituto Nacional do Cancer, Rio de Janeiro, RJ (Brazil); Biaggio, Maria F. de [Universidade do Estado, Rio de Janeiro, RJ (Brazil)

    1998-09-01

    This paper describes a manual method for dose calculation in brachytherapy of gynecological tumors, which allows the calculation of the doses at any plane or point of clinical interest. This method uses basic principles of vectorial algebra and the simulating orthogonal films taken from the patient with the applicators and dummy sources in place. The results obtained with method were compared with the values calculated with the values calculated with the treatment planning system model Theraplan and the agreement was better than 5% in most cases. The critical points associated with the final accuracy of the proposed method is related to the quality of the image and the appropriate selection of the magnification factors. This method is strongly recommended to the radiation oncology centers where are no treatment planning systems available and the dose calculations are manually done. (author) 10 refs., 5 figs.

  10. High-dose Extended-Field Irradiation and High-Dose-Rate Brachytherapy With Concurrent Chemotherapy for Cervical Cancer With Positive Para-Aortic Lymph Nodes

    International Nuclear Information System (INIS)

    Kim, Young Seok; Kim, Jong Hoon; Ahn, Seung Do; Lee, Sang-wook; Shin, Seong Soo; Nam, Joo-Hyun; Kim, Young-Tak; Kim, Yong-Man; Kim, Jong-Hyeok; Choi, Eun Kyung

    2009-01-01

    Purpose: To determine the efficacy and toxicity of extended-field radiotherapy (RT) with concurrent platinum-based chemotherapy in patients with uterine cervical carcinoma and positive para-aortic nodes. Methods and Materials: We retrospectively reviewed the results for 33 women with Stage IB-IVB cervical cancer. Each patient had received 59.4 Gy, including a three-dimensional conformal boost to the para-aortic lymph nodes and 41.4-50.4 Gy of external beam radiotherapy to the pelvis. Each patient also underwent six or seven applications of high-dose-rate brachytherapy (median, 5 Gy to point A at each session). Results: The median follow-up period of surviving patients was 39 months. The most common acute toxicity was hematologic, observed in 23 women. Severe acute and late gastrointestinal toxicity was observed in 3 and 4 patients, respectively. More than three-quarters of patients showed a complete response, encompassing the primary mass, metastatic pelvic, and para-aortic lymph nodes. Of the 33 women, 15 had no evidence of disease, 6 had persistent disease, 4 developed in-field failures, and 6 developed distant failures. The 5-year overall and disease-free survival rate was 47% and 42%, respectively. Conclusion: Concurrent chemoradiotherapy with extended-field radiotherapy is feasible in women with uterine cervical carcinoma and positive para-aortic lymph nodes, with acceptable late morbidity and a high survival rate, although it was accompanied by substantial acute toxicity.

  11. Monte Carlo calculations for doses in organs and tissues to oral radiography; Calculo de Monte Carlo para doses em orgaos e tecidos para radiologia oral

    Energy Technology Data Exchange (ETDEWEB)

    Sampaio, E V.M.

    1986-12-31

    Using the MIRD 5 phantom and Monte Carlo technique, organ doses in patients undergoing external dental examination were calculated taking into account the different x-ray beam geometries and the various possible positions of x-ray source with regard to the head of the patient. It was necessary to introduce in the original computer program a new source description specific for dental examinations. To have a realistic evaluation of organ doses during dental examination it was necessary to introduce a new region in the phantom heat which characterizes the teeth and salivary glands. The attenuation of the x-ray beam by the lead shield of the radiographic film was also introduced in the calculation. (author).

  12. Radiosurgery for Para-IAC Meningiomas: The Effect of Radiation Dose to the Cochlea on Hearing Outcome

    International Nuclear Information System (INIS)

    Kim, Young-Hoon; Kim, Dong Gyu; Han, Jung Ho; Chung, Hyun-Tai; Kim, In Kyung; Song, Sang Woo; Park, Jeong-Hoon; Kim, Jin Wook; Kim, Yong Hwy; Park, Chul-Kee; Kim, Chae-Yong; Paek, Sun Ha; Jung, Hee-Won

    2012-01-01

    Purpose: This study was performed to assess the radiosurgical results of meningiomas extending into the internal acoustic canal (para-IAC meningiomas), with a particular focus on the effect of radiation dose to the cochlea on hearing outcome. Methods and Materials: A total of 50 patients who underwent radiosurgery for para-IAC meningiomas between 1998 and 2009, which were followed for 2 years, were enrolled. The mean age was 55.8 years (range, 15–75). The mean tumor volume was 6.1 cm 3 (range, 1.0–19.0), the mean tumor length in the IAC was 6.9 mm (range, 1.3–13.3), and the mean prescribed marginal dose was 13.1 Gy (range, 10–15) at an isodose line of 50%. The mean follow-up duration was 46 months (range, 24–122). Results: Eight (16.0%) patients had nonserviceable hearing at the time of surgery. At the last follow-up, the tumor control rate was 94%; unchanged in 17 patients, decreased in 30 patients, and increased in 3 patients. Among 42 patients with serviceable hearing at the time of radiosurgery, it was preserved in 41 (97.6%) patients at the last follow-up. The maximal and mean radiation doses to the cochleae of these 41 patients were 5.8 Gy ± 0.3 (range, 3.1–11.5) and 4.3 Gy ± 0.2 (range, 2.2–7.5), respectively. The maximal dose to the cochlea of the patient who lost hearing after radiosurgery was 4.7 Gy. Conclusions: The radiation dose to the cochlea may have the minimal toxic effect on the hearing outcome in patients who undergo radiosurgery for para-IAC meningiomas.

  13. Out-of-field organ doses and associated radiogenic risks from para-aortic radiotherapy for testicular seminoma

    Energy Technology Data Exchange (ETDEWEB)

    Mazonakis, Michalis, E-mail: mazonak@med.uoc.gr; Berris, Theocharis; Damilakis, John [Department of Medical Physics, Faculty of Medicine, University of Crete, P. O. Box 2208, 71003 Iraklion, Crete (Greece); Varveris, Charalambos; Lyraraki, Efrossyni [Department of Radiotherapy and Oncology, University Hospital of Iraklion, 71110 Iraklion, Crete (Greece)

    2014-05-15

    Purpose: The aims of this study were to (a) calculate the radiation dose to out-of-field organs from radiotherapy for stage I testicular seminoma and (b) estimate the associated radiogenic risks. Methods: Monte Carlo methodology was employed to model radiation therapy with typical anteroposterior and posteroanterior para-aortic fields on an anthropomorphic phantom simulating an average adult. The radiation dose received by all main and remaining organs that defined by the ICRP publication 103 and excluded from the treatment volume was calculated. The effect of field dimensions on each organ dose was determined. Additional therapy simulations were generated by introducing shielding blocks to protect the kidneys from primary radiation. The gonadal dose was employed to assess the risk of heritable effects for irradiated male patients of reproductive potential. The lifetime attributable risks (LAR) of radiotherapy-induced cancer were estimated using gender- and organ-specific risk coefficients for patient ages of 20, 30, 40, and 50 years old. The risk values were compared with the respective nominal risks. Results: Para-aortic irradiation to 20 Gy resulted in out-of-field organ doses of 5.0–538.6 mGy. Blocked field treatment led to a dose change up to 28%. The mean organ dose variation by increasing or decreasing the applied field dimensions was 18.7% ± 3.9% and 20.8% ± 4.5%, respectively. The out-of-field photon doses increased the lifetime intrinsic risk of developing thyroid, lung, bladder, prostate, and esophageal cancer by (0.1–1.4)%, (0.4–1.1)%, (2.5–5.4)%, (0.2–0.4)%, and (6.4–9.2)%, respectively, depending upon the patient age at exposure and the field size employed. A low risk for heritable effects of less than 0.029% was found compared with the natural incidence of these defects. Conclusions: Testicular cancer survivors are subjected to an increased risk for the induction of bladder and esophageal cancer following para-aortic radiotherapy. The

  14. Calculation of dose equivalents for photon skyshine production; Calculo da dose equivalente para fotons decorrente da producao de skyshine

    Energy Technology Data Exchange (ETDEWEB)

    Frota, Marco A.; Kelecom, Alphonse [Universidade Federal Fluminense, Niteroi, RJ (Brazil). Dept. de Biologia Geral. Lab. de Radiobiologia e Radiometria (LARARA)]. E-mail: egbakel@vm.uff.br

    2005-07-01

    Some radiation facilities are designed with little shielding in the ceiling above the accelerator. A problem may then arise as a result of the radiation scattered by the atmosphere to points at ground level outside the treatment room. Stray radiation of this type is referred to as skyshine, and the National Council on Radiation Protection and Measurements Report No. 51 (NCRP 1977) gives methods for the calculation of skyshine for accelerator facilities. McGinley (1993) has compared skyshine measurements made at an 18 MeV medical accelerator facility with values calculated using the techniques presented in NCRP Report No. 51. Measurements were made of the photon levels outside a treatment room housing a Varian 2100 deg C. The roof above the accelerator was designed for weather protection only and offered little shielding for the primary beam and scattered radiation. The distance from the treatment room floor to the roof was 4.27 m, and the primary walls were constructed of concrete 2.0 m thick.The secondary walls were fabricated of concrete 0.99 m thick. The results for the photon skyshine rate dose as a function of distance from the isocenter using Monte Carlo code, are compared with those in NCRP publication 74 and measured obtained. The photon skyshine dose rates simulated for real clinic spectra transmitted through roof range from 4.7 to 14.6 nSv.s{sup -1}. (author)

  15. Recomendações para se evitar grandes erros de dose em tratamentos radioterapêuticos Recommendations to avoid gross errors of dose in radiotherapeutic treatments

    Directory of Open Access Journals (Sweden)

    Cleber Nogueira de Souza

    2001-02-01

    Full Text Available Erros humanos são uma importante fonte de falhas em todos os passos do planejamento e do tratamento radioterapêutico. Com o objetivo de reduzir este grau de incerteza, várias organizações especializadas recomendam minuciosos programas de garantia da qualidade. No Brasil, programas deste tipo vêm tendo sua exigência intensificada, e a maioria dos serviços de radioterapia vem se orientando neste sentido, tanto em relação aos equipamentos de radiação e dosimetria, quanto em relação à verificação dos cálculos de dose em pacientes e das revisões das fichas de planejamento. Como uma contribuição a este esforço de qualidade, apresentam-se algumas recomendações para se evitar falhas de tratamento devidas a erros na dose de radiação recebida pelo paciente, como redundância nas verificações dos cálculos feitos manualmente ou por computador, e, também, a verificação da dose acumulada para cada paciente sob tratamento, semanalmente, além de se evitar a possibilidade de acesso a qualquer sistema de segurança do equipamento ao pessoal técnico treinado para apenas o operar. Além disso, deve-se considerar a possibilidade de se empregar um sistema computadorizado de verificação e registro do tratamento, dessa maneira prevenindo-se erros durante a aplicação diária devidos à seleção indevida dos diferentes parâmetros do tratamento. Reportam-se quatro incidentes radioativos recentes ocorridos no mundo, com injúrias em pacientes, e algumas ocorrências de erros grandes de dose.Human mistakes are an important source of errors in radiotherapy and may occur at every step of the radiotherapeutic planning and treatment. To reduce this level of uncertainties, several specialized organizations have recommended a comprehensive quality assurance program. In Brazil, the requirement for these programs has been strongly stressed, and most radiotherapy services have pursued this goal regarding radiation units and dosimetry equipment

  16. Complications from high-dose para-aortic and pelvic irradiation for malignant genitourinary tumors

    International Nuclear Information System (INIS)

    Komaki, R.; Barber-Derus, S.; Glisch, C.; Lawton, C.A.; Cox, J.D.; Wilson, J.F.

    1986-01-01

    Between 1967 and 1982, 59 patients (33 with gynecologic malignancies and 26 with malignant tumors of the genitourinary system) received irradiation of 40 Gy or more for metastases to the para-aortic lymph nodes, in addition to pelvic irradiation. Disease in the para-aortic lymph nodes was controlled in 50 patients; the treatment failed in nine. Moderately acute side effects were seen in 25 patients, but none was severe. Late effects of irradiation were moderate in five patients and severe in three. Thirty patients are alive at 5 years. The benefits of local control and prolonged disease-free survival appear to outweigh considerably the risk of late effects from pelvic and para-aortic irradiation for advanced malignant tumors of the genitourinary system

  17. Cálculo de la concurrencia para el modelo de Heisenberg

    OpenAIRE

    Castellanos,R; Franco,R; Silva-Valencia,J

    2010-01-01

    La concurrencia es una cantidad que nos permite medir el grado de entreveramiento que presenta un sistema cuántico y se puede calcular a partir de la matriz densidad reducida. En este artículo mostramos explicitamente como calcular la concurrencia para una cadena finita de espines s =1/2 descrita por el modelo de Heisenberg anistrópico. Nosotros mostramos que para cadenas finitas la concurrencia tiene un máximo en el punto crítico Δ = 1, la cual es una de las principales características ...

  18. Methodology to administer therapeutic dose of I-131; Metodologia para administrar dosis terapeutica de I-131

    Energy Technology Data Exchange (ETDEWEB)

    Basteris M, J.; Gomez D, R. [Universidad Autonoma de Yucatan, Facultad de Medicina, Merida, Yucatan (Mexico)

    2007-07-01

    The present work suggests the use of measures guided to eliminate the resulting chronic sialoadenitis of the treatment of the thyroid cancer with Iodine-131, as well as the use of citric fruits to stimulate the salivation, the post-dose administration of liquids to accelerate the gastric emptying avoiding the secondary effects as the vomit is included. (Author)

  19. High-Temperature Gas-Cooled Reactor Critical Experiment and its Application to Thorium Absorption Rates; Experience Critique pour l'Etude d'un Reacteur a Haute Temperature, Refroidi par un Gaz et son Application a la Determination des Taux d'Absorption du Thorium; Kriticheskij opyt, postavlennyj na vysokotemperaturnom reaktore s gazovym okhlazhdeniem, i primenenie ego dlya opredeleniya stepeni pogloshcheniya toriya; Experimento Critico Efectuado en un Reactor de Elevada Temperatura Refrigerado por Gas y su Aplicacion para Calcular los Indices de Absorcion del Torio

    Energy Technology Data Exchange (ETDEWEB)

    Bardes, R. G.; Brown, J. R.; Drake, M. K.; Fischer, P. U.; Pound, D. C.; Sampson, J. B.; Stewart, H. B. [General Dynamics Corporation,San Diego, CA (United States)

    1964-04-15

    variations en fonction de la temperature (coefficient Doppler d'activation). Pour mesurer le coefficient Doppler par oscillation de la reactivite, on se sert de la totalite de la cartouche centrale au cours d'une operation qui permet de la porter a une temperature pouvant atteindre 425 Degree-Sign C et d'eliminer experimentalement les effets qui ne contribuent pas a la capture de neutrons de resonance par le thorium. Pour toute une gamme d'experiences, les resultats obtenus concordent bien avec les resultats theoriques. Le memoire decrit la mesure de l'integrale de resonance pour le thorium et ses variations en fonction de la temperature. Dans le procede que l'on a mis au point pour mesurer la capture de resonance, on utilise l'or comme etalon et le vanadium comme matiere donnant le taux d'absorption en 1/v. Ce procede a ete choisi parce que le thorium est disperse dans le graphite et qu'il est difficile d'appliquer le procede habituel du rapport cadmium. Les resultats empiriques concordent bien avec les resultats theoriques dans une large gamme de variables. En outre, les resultats des mesures du coefficient Doppler par les deux methodes (oscillation de la reactivite et activation) concordent. Les auteurs estiment que ce fait merite d'etre releve, car dans les ouvrages publies jusqu'ici ces deux procedes donnaient des resultats differents. (author) [Spanish] Al definir los principios teoricos del reactor de elevada temperatura refrigerado por gas, y de su primer prototipo en Peach Bottom, la General Atomic decidio efectuar un experimento critico con miras a reunir ciertos datos de entrada requeridos para el analisis nuclear. Debido a las necesidades especificas de la teoria de las construcciones nucleares, en lo que atane a los datos de entrada acerca de la absorcion del torio, los autores elaboraron un sistema experimental formado por un conjunto critico con reticulado central rodeado por una region amortiguadora y otra activado'. Este tipo de conjunto, en el que el

  20. Rectal dose assessment in patients submitted to high-dose-rate brachytherapy for uterine cervix cancer; Avaliacao da dose no reto em pacientes submetidas a braquiterapia de alta taxa de dose para o tratamento do cancer do colo uterino

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Jetro Pereira de [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Faculdade de Medicina; Rosa, Luiz Antonio Ribeiro da [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)], e-mail: lrosa@ird.gov.br; Batista, Delano Valdivino Santos; Bardella, Lucia Helena [Instituto Nacional de Cancer (INCA), Rio de Janeiro, RJ (Brazil). Unit of Medical Physics; Carvalho, Arnaldo Rangel [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil). Lab. of Thermoluminescent Dosimetry

    2009-03-15

    Objective: The present study was aimed at developing a thermoluminescent dosimetric system capable of assessing the doses delivered to the rectum of patients submitted to high-dose-rate brachytherapy for uterine cervix cancer. Materials and methods: LiF:Mg,Ti,Na powder was the thermoluminescent material utilized for evaluating the rectal dose. The powder was divided into small portions (34 mg) which were accommodated in a capillary tube. This tube was placed into a rectal probe that was introduced into the patient's rectum. Results: The doses delivered to the rectum of six patients submitted to high-dose-rate brachytherapy for uterine cervix cancer evaluated by means of thermoluminescent dosimeters presented a good agreement with the planned values based on two orthogonal (anteroposterior and lateral) radiographic images of the patients. Conclusion: The thermoluminescent dosimetric system developed in the present study is simple and easy to be utilized as compared to other rectal dosimetry methods. The system has shown to be effective in the evaluation of rectal doses in patients submitted to high-dose-rate brachytherapy for uterine cervix cancer. (author)

  1. SCINFI, a program to calculate the standardization curve in liquid scintillation counting; SCINFI, un programa para calcular la curva de calibracion eficiencia-extincion en centelleo liquido

    Energy Technology Data Exchange (ETDEWEB)

    Grau Carles, A.; Grau Malonda, A.

    1984-07-01

    A code, SCINFI, was developed, written in BASIC, to compute the efficiency- quench standardization curve for any radionuclide. The program requires the standardization curve for 3H and the polynomial relations between counting efficiency and figure of merit for both 3H and the problem (e.g. 14{sup C}). The program is applied to the computation of the efficiency-quench standardization curve for 14{sup c}. Five different liquid scintillation spectrometers and two scintillator solutions have bean checked. The computation results are compared with the experimental values obtained with a set of 14{sup c} standardized samples. (Author)

  2. Metodología para calcular la profundidad de socavación general en ríos de montaña (lecho de gravas)

    OpenAIRE

    Barbosa Gil, Sebastian

    2013-01-01

    La modelación de la profundidad de socavación general se puede hacer desde varios enfoques, a partir de metodologías netamente empíricas como la teoría del régimen, formulaciones semi-empíricas basadas en una condición de equilibrio, o mediante balances de masa entre el sedimento transportado y la capacidad de transporte de una corriente. En éste trabajo se comparan los resultados obtenidos por estas diferentes metodologías a partir de mediciones bienales de cambios en el lecho de un tramo...

  3. TRANGE: computer code to calculate the energy beam degradation in target stack; TRANGE: programa para calcular a degradacao de energia de particulas carregadas em alvos

    Energy Technology Data Exchange (ETDEWEB)

    Bellido, Luis F.

    1995-07-01

    A computer code to calculate the projectile energy degradation along a target stack was developed for an IBM or compatible personal microcomputer. A comparison of protons and deuterons bombarding uranium and aluminium targets was made. The results showed that the data obtained with TRANGE were in agreement with other computers code such as TRIM, EDP and also using Williamsom and Janni range and stopping power tables. TRANGE can be used for any charged particle ion, for energies between 1 to 100 MeV, in metal foils and solid compounds targets. (author). 8 refs., 2 tabs.

  4. Propuesta para calcular los costos de calidad en la industria del Banano orgánico de la Región Lambayeque.

    OpenAIRE

    Vásquez Chirre, Fátima del Carmen

    2014-01-01

    El banano orgánico es un producto diferenciado (en relación a los productos convencionales) y, por lo tanto, con valor agregado, que se dirige a un nicho específico de mercado. En el Perú, la producción y la exportación de banano orgánico es una actividad relativamente nueva que surge a finales de los años noventa. La producción se localiza en la zona norte del país, en las regiones de Tumbes, Piura y Lambayeque, donde existen 3.414 hectáreas certificadas. De ellas, el 30% se concent...

  5. Critical Consideration of the Methods of Calculation Used in the Evaluation of the Absorbed Dose to the Skin in Cases of External Contamination; Observations Critiques sur les Methodes de Calcul Utilisees pour l'Evaluacion de la Dose Absorbee par la Peau en Cas de Contamination Externe; 041a 0420 0414 ; Observaciones Criticas Sobre los Metodos de Calculo Utilizados para Evaluar la Dosis Absorbida por la Piel en Caso de Contaminacion Externa

    Energy Technology Data Exchange (ETDEWEB)

    Casnati, E.; Breuer, F. [Gruppo di Dosimetria e Standardizzazione, CNEN, Centro di Studi Nucleari della Casaccia, Rome (Italy)

    1965-06-15

    resultats permettent de conclure que, dans la geometrie consideree, on peut determiner par des formules de type exponentielle, d'une part la dose imputable aux rayons beta et, d'autre part, la dose imputable aux rayons gamma pour la couche basale de la peau;- on peut considerer les resultats comme acceptables du point de vue de la radioprotection. (author) [Spanish] La dosis absorbida, suele calcularse mediante la formula de Loevinger cuando se trate de particulas beta mientras que para las radiaciones electromagneticas se recurre habitualmente a una formula exponencial. En la memoria, los autores se proponen examinar si en el caso de contaminacion cutanea puede considerarse satisfactorio el empleo de una formula exponencial (la formula de Rossi y Ellis) y de una formula similar para calcular la dosis beta y la dosis gamma, respectivamente. Con este objeto, se han comparado los resultados.obtenidos para este tipo especial de geometria por medio de la formula de Rossi y Ellis y con la formula de Loevinger para partfculas beta; por lo que respecta a la radiacion gamma, se han comparado los valores obtenidos mediante la formula exponencial y con otras dos formulas mas complejas, que se ajustan a las condiciones de acumulacion fotonica maxima nula, respectivamente. Estos resultados permiten sacar la conclusion de que, dadas las condiciones geometricas de que se trata, pueden determinarse mediante la formula de tipo exponencial tanto la dosis de radiacion beta como la dosis de radiacion gamma en la dermis. Los resultados son aceptables desde el punto de vista de la proteccion radiologica. (author) [Russian] Obychno pri podschete dozy ispol'zuetsja formula Laevingera dlja chastic i jeksponencial'naja formula dlja jelektromagnitnyh izluchenij. V doklade rassmatrivaetsja vopros o tom, mozhno li schitat' udovletvoritel'nym ispol'zovanie jeksponencial'noj formuly (podobnoj formule Rossi i Jellisa) i analogichnyh formul pri podschete sootvetstvenno beta- i gamma-dozy. S jetoj cel

  6. Cocleotoxicidade da gentamicina por doses habituais para neonatos - estudo funcional A functional study on gentamicin-related cochleotoxicity in its conventional dose in newborns

    Directory of Open Access Journals (Sweden)

    Carla Luiza Baggio

    2010-02-01

    Full Text Available A identificação precoce das alterações auditivas possibilita a intervenção ainda no "período crítico" e ideal de estimulação da linguagem e da audição. A ototoxicidade infantil é um tema bastante controverso. Têm sido relatadas percentagens variáveis de casos de ototoxicidade em crianças com vários antibióticos aminoglicosídeos. Os principais grupos pediátricos que recebem antibióticos aminoglicosídeos são recém-nascidos com infecções graves na UTI neonatal. OBJETIVOS: Verificar o aspecto funcional das células ciliadas externas da cóclea a esquemas terapêuticos utilizados para o tratamento de infecções no período neonatal. FORMA DE ESTUDO: Experimental. MATERIAL E MÉTODO: Foram estudadas 26 cobaias albinas, através das emissões otoacústicas por produto de distorção, prévia e posteriormente a aplicação de gentamicina. RESULTADOS: Em todas as avaliações, o estado funcional das células ciliadas externas, estudadas pelas emissões otoacústicas por produto de distorção, mostraram-se preservadas. CONCLUSÃO: Neste experimento não foram observadas alterações no funcionamento das células ciliadas externas de cobaias albinas sob tratamento com gentamicina nas doses de 4 mg/Kg/dia e 2,5 mg/Kg/dia a cada 12 horas, por 10 e 14 dias.The early identification of hearing impairment allows for an intervention still in the "critical" and ideal period of hearing and language stimulation. Pediatric ototoxicity is a very controversial topic. There have been variable percentages of ototoxicity cases in children with different aminoglycosides antibiotics. The main pediatric groups whom receive aminoglycosides are newborns with severe infections on the neonatal ICU. AIM: to check the functional aspect of the cochlear external hair cells and treatment regimens used to treat infections during the neonatal period. STUDY DESIGN: Experimental. Materials and Methods: we studied 26 albino guinea pigs, through distortion

  7. Cytogenetics dosimetry: dose-response curve for low doses of X-ray; Dosimetria citogenetica: curva dosis-respuesta para bajas dosis de rayos-X

    Energy Technology Data Exchange (ETDEWEB)

    Lara, Virginia E. Noval; Pineda Bolivar, William R.; Riano, Victor M. Pabon, E-mail: venovall.15@hotmail.com, E-mail: wrpineda@misena.edu.co, E-mail: vmpabonr@udistrital.edu.co [Universidad Distrital Francisco Jose de Caldas (UD), Bogota (Colombia). Grupo de Investigacion en Ciencia y Tecnologia Nuclear; Ureana, Cecilia Crane, E-mail: cecicrane@yahoo.com [Instituto Nacional de Salud (INS), Bogota (Colombia). Laboratorio de Genetica

    2013-07-01

    The purpose of this study was to conduct a preliminary study for the standardization in the future, the dose-response curve for low doses of X-rays, through the analysis of in vitro cultures of peripheral blood samples of 3 men and 3 women occupationally not exposed to artificial sources of ionizing radiation, age 18-40 years, where possible nonsmokers.

  8. Dose inseminante para fertilização artificial de ovócitos de dourado Insemination dose for artificial fertilization of dourado oocytes

    Directory of Open Access Journals (Sweden)

    Eduardo Antônio Sanches

    2009-11-01

    Full Text Available Objetivou-se determinar a dose inseminante adequada para uso na fertilização artificial de ovócitos de dourado (Salminus brasiliensis. Os ovócitos foram distribuídos em delineamento inteiramente casualizado, e fertilizados com uma das relações espermatozoides/ovócito 6,0×10³; 6,0×10(4; 6,0×10(5; 6,0×10(6 ou 3,0×10(7, cada uma com quatro repetições. Considerou-se unidade experimental uma incubadora de volume útil de 2,5 L, contendo 2,0 mL de ovócitos não-hidratados. As taxas de fertilização foram mensuradas 8 horas após o início da fertilização. Com intuito de verificar possíveis efeitos da diluição seminal na movimentação dos espermatozoides, realizou-se a mensuração do tempo de duração da motilidade espermática dos espermatozoides de dourado, ativados por meio de diferentes relações de diluição: 6,8×10-5; 6,8×10-4; 6,8×10-3; 6,8×10-2; 3,4×10-1 e 1,0 mL de sêmen por mL de água. O tempo de duração da motilidade foi avaliado em delineamento inteiramente casualizado composto de seis tratamentos e três repetições. As taxas de fertilização apresentaram relação quadrática com o número de espermatozoides por ovócito. As relações de diluição do sêmen tiveram efeito inversamente proporcional sobre a duração da motilidade espermática. A relação que proporcionou melhores taxas de fertilização artificial de ovócitos de dourado (Salminus brasiliensis foi de 30.722 espermatozoides por ovócio.The objective of the present study was to determine the proper insemination dose of dourado (Salminus brasiliensis oocytes. The oocytes were placed in a randomized complete design and fertilized with one of the spermatozoa.oocytes-1 ratio, 6.0×10³, 6.0×10(4, 6.0×10(5, 6.0×10(6, 3.0×10(7 SPZ:OOC, each one with four replications. An experimental unit was considered to be an incubator with a 2.5L useful volume containing 2.0 mL non-hydrated oocytes. The fertilization rates were measured eight hours

  9. Propuesta para el cálculo del Índice Dm para la validez de los ítemes

    OpenAIRE

    Dominguez Lara, Sergio

    2013-01-01

    Se presenta un programa en formato MS Excel para calcular el índice Dm para la validez de los ítemes. La validez es un proceso de acumulación de pruebas para apoyar la interpretación y el uso de las puntuaciones de los tests psicológicos, siendo las relaciones de los puntajes con otras variables externas una importante fuente de validación. Una variante es la llamada validez relacionada al criterio, en la cual se espera una correlación significativa con aquellos criterios externos que son teó...

  10. Comparison of dose distribution for proton beams and electrons: advantages and disadvantages; Comparacao de distribuicao de dose para feixes de protons e eletrons: vantagens e desvantagens

    Energy Technology Data Exchange (ETDEWEB)

    Neto, Joao T.M.; Ferreira, Maira B.; Braga, Victor B. [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil)

    2016-07-01

    This study consists of a simulation of cancer therapy using a beam of protons and electrons. By comparing dose distribution curves for both beams we have showed the advantages and disadvantages of both therapies. The study was performed with Monte Carlo simulations using Geant4 code for a brain tumor, and it was found that the presence of the Bragg peak in proton beam allows a higher dose deposition in tumor and protection of adjacent tissues, while the electron beam has an entry dose in the tissue higher than the proton, yielding to the tissue neighbors of the tumor, unnecessary radiation. Moreover, it was also found significant production of neutrons from the proton beam, showing its main disadvantage. The continuation of this work will add the comparison with clinical beams of photons. (author)

  11. Estimation of absorbed dose by newborn patients subjected to chest radiographs; Estimativa de dose efetiva para radiografias do torax em pediatria neonatal

    Energy Technology Data Exchange (ETDEWEB)

    Bunick, Ana P. [Faculdades Pequeno Principe, Curitiba, PR (Brazil); Schelin, Hugo R. [Instituto de Pesquisa Pele Pequeno Principe, Curitiba, PR (Brazil); Denyak, Valeriy [Hospital Infantil Pequeno Principe, Curitiba, PR (Brazil)

    2016-07-01

    The aim of this study is to present an estimate of the effective dose received by newborn patients hospitalized in NICU and subjected to X-ray examinations of the chest in the AP projection. Initially, were followed examinations chest X-rays performed on newborn patients and subsequently, simulated in a newborn simulator object. The ESAK values obtained by TLDs were used to calculate the effective dose obtained at each examination by Caldose{sub X} software. The estimated values for the effective dose in the simulated exams in this study range from 2,3μSv the 10,7μSv. The results achieved are, generally, inferior to those reported for similar previous studies. (author)

  12. Protocol for adaptation of internal dosimetry techniques for planning of individualized doses of {sup 131}I in pediatric patients; Protocolo para adaptacao de tecnicas de dosimetria interna para planejamento de doses individualizadas de {sup 131}I em pacientes pediatricos

    Energy Technology Data Exchange (ETDEWEB)

    Biancardi, Rodrigo

    2011-07-01

    The optimization of radiation doses is emphasized in diseases with good prognosis, as differentiated thyroid carcinomas, especially in pediatric patients, since the radiation risk is conversely proportional to age. Aiming to establish individual treatment planning, it has been studied four dosimetry methodologies (external dose monitoring, image quantification, urine and blood bioassay) for four 13.3 {+-} 1.5-year-old female patients, who received 107 {+-} 15 MBq (2,9 {+-} 0,4 mCi) for tracer dose and 5.5 {+-} 0.3 GBq (149 {+-} 8 mCi) for thyroid ablation. Effective half-lives, residence times and cumulated activities were estimated in organs and tissues with iodine uptake, through planar images quantification by conjugate-view and attenuation correction, in order to compare biokinetic behavior in tracer dose and ablative dose phases. For external monitoring, two patients had similar whole-body effective half-lives in both phases. For this methodology, despite the uncertainties associated to measurements, equipment used and procedures performed were adequate. For urine bioassay, there were not similarities among the patients whole-body effective half-lives. Through blood bioassay, it was observed that 0.2 % of the administered activity for ablative dose remained in the blood until 76 hours after administration. The external monitoring allowed estimating effective doses in patients mothers by conversion of the environmental equivalent dose. In the ablative dose phase, the effective doses resulted in 1.3 {+-} 0.3 mSv in the hospital and 0.3 {+-} 0.1 mSv in patients houses. (author)

  13. Development of Software for dose Records Data Base Access; Programacion para la consulta del Banco de Datos Dosimetricos

    Energy Technology Data Exchange (ETDEWEB)

    Amaro, M

    1990-07-01

    The CIEMAT personal dose records are computerized in a Dosimetric Data Base whose primary purpose was the individual dose follow-up control and the data handling for epidemiological studies. Within the Data Base management scheme, software development to allow searching of individual dose records by external authorised users was undertaken. The report describes the software developed to allow authorised persons to visualize on screen a summary of the individual dose records from workers included in the Data Base. The report includes the User Guide for the authorised list of users and listings of codes and subroutines developed. (Author) 2 refs.

  14. Criteria for calculation of effective dose from the individual monitoring; Criterios para calculo de dose efetiva a partir da monitoracao individual

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-11-15

    This Regulation refers to the requirements of the Regulation CNEN-NN.3.01. 'Basic Act of Radiological Protection', as expressed in the section 5.9, and its application to the effective dose calculation for individual occupationally exposed. from the internal and external individual monitoring data

  15. Methodology for management of therapeutic dose of I-131; Metodologia para administrar dosis terapeutica de I-131

    Energy Technology Data Exchange (ETDEWEB)

    Basteris M, J.; Gomez D, R. [Universidad Autonoma de Yucatan, Facultad de Medicina, Merida, Yucatan (Mexico)

    2007-07-01

    The present work suggests the use of measures guided to eliminate the resulting chronic sialoadenitis of the treatment previously described with a therapeutic dose bigger than ablative of Iodine 131, as well as the use of citric fruits to stimulate the salivation, the administration of liquid post-dose is included to accelerate the gastric emptying avoiding the secondary effects as the vomit. (Author)

  16. DosedPet application for Nuclear Medicine: Calculation of the volume of medication needed for PET/CT patient; Aplicativo DosedPet para uso em Medicina Nuclear: calculo do volume de medicamento necessario para paciente de PET/CT

    Energy Technology Data Exchange (ETDEWEB)

    Nascimento, Pedro Augusto do; Rodrigues, Araken dos S. Werneck, E-mail: pedroan88@gmail.com [Universidade de Brasilia (UnB), DF (Brazil). Programa de Pos Graduacao em Ciencias e Tecnologias em Saude

    2016-07-01

    This paper presents the application (APP) DosePet that calculates the amount of medicament for PET / CT in patients according to the predetermined radiation dose. The software has been designed using the web MIT App Inventor2 tool for Android platform. The application allows the workers to simulate the amount of radiation still existing in the facilities after the applications, increasing security and reducing exposures, and enable greater efficiency in the use of the radiopharmaceutical. (author)

  17. A phantom for assessing the personal dose equivalent, H{sub P}(10); Um fantoma para a avaliacao do equivalente de dose pessoal, H{sub P}(10).

    Energy Technology Data Exchange (ETDEWEB)

    Santoro, C.; Filho, J.A [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Departamento de Energia Nuclear; Santos, M.A.P.; Filho, L.C.G., E-mail: chsantoro@gmail.com, E-mail: masantos@cnen.gov.br, E-mail: l.filho@cnen.gov.br, E-mail: jaf@ufpe.br [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil)

    2013-10-15

    Characteristics of a phantom designed to evaluate the personal dose equivalent, H{sub P}(10), and appropriate for photographic dosimetry are presented. It is called HP(10) phantom due to cavities constructed to insert dosimetric films at a depth of 10 mm. The H{sub P}(10) phantom is irradiated with ionizing radiation energy, E, from 45 to 1250 keV, with doses ranging from 0.2 to 50 mSv. It is positioned in the direction α = 0 °, and the radiation field focusing perpendicular to its front surface. So, are established calibration curves of dosimeters in the position conventionally true and quantities H{sub P}(10). It made a comparison between the responses obtained with the H{sub P}(10) phantom and responses obtained when using the calibration procedure recommended by ISO dosimeters. The ISO recommends getting the air kerma, Ka, for photons at test point of the radiation field by an ionization chamber. And through conversion coefficients, h{sub pK} (10; E, α), becomes the air kerma for H{sub P}(10). The ISO 4037-3 recommendation has been studied by researchers to ensure that the low energy spectral differences occur in radiation fields which are generated by various X-ray equipment, and induce changes in the percentages of conversion coefficients on the order of 10% to 90% . On the basis of the recommendations ISO, this article develops phantom able to assess the dose to the influence of scattering and absorption of radiation, its implications with respect to dosimetry, providing improvement in the assessment of doses. (author)

  18. Calculation of neutron fluence to dose equivalent conversion coefficients using GEANT4; Calculo de coeficientes de fluencia de neutrons para equivalente de dose individual utilizando o GEANT4

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro, Rosane M.; Santos, Denison de S.; Queiroz Filho, Pedro P. de; Mauricio, CLaudia L.P.; Silva, Livia K. da; Pessanha, Paula R., E-mail: rosanemribeiro@oi.com.br [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2014-07-01

    Fluence to dose equivalent conversion coefficients provide the basis for the calculation of area and personal monitors. Recently, the ICRP has started a revision of these coefficients, including new Monte Carlo codes for benchmarking. So far, little information is available about neutron transport below 10 MeV in tissue-equivalent (TE) material performed with Monte Carlo GEANT4 code. The objective of this work is to calculate neutron fluence to personal dose equivalent conversion coefficients, H{sub p} (10)/Φ, with GEANT4 code. The incidence of monoenergetic neutrons was simulated as an expanded and aligned field, with energies ranging between thermal neutrons to 10 MeV on the ICRU slab of dimension 30 x 30 x 15 cm{sup 3}, composed of 76.2% of oxygen, 10.1% of hydrogen, 11.1% of carbon and 2.6% of nitrogen. For all incident energy, a cylindrical sensitive volume is placed at a depth of 10 mm, in the largest surface of the slab (30 x 30 cm{sup 2}). Physic process are included for neutrons, photons and charged particles, and calculations are made for neutrons and secondary particles which reach the sensitive volume. Results obtained are thus compared with values published in ICRP 74. Neutron fluence in the sensitive volume was calculated for benchmarking. The Monte Carlo GEANT4 code was found to be appropriate to calculate neutron doses at energies below 10 MeV correctly. (author)

  19. Experimental method for calculation of effective doses in interventional radiology; Metodo experimental para calculo de dosis efectivas en radiologia intervencionista

    Energy Technology Data Exchange (ETDEWEB)

    Herraiz Lblanca, M. D.; Diaz Romero, F.; Casares Magaz, O.; Garrido Breton, C.; Catalan Acosta, A.; Hernandez Armas, J.

    2013-07-01

    This paper proposes a method that allows you to calculate the effective dose in any interventional radiology procedure using an anthropomorphic mannequin Alderson RANDO and dosimeters TLD 100 chip. This method has been applied to an angio Radiology procedure: the biliary drainage. The objectives that have been proposed are: to) put together a method that, on an experimental basis, allows to know dosis en organs to calculate effective dose in complex procedures and b) apply the method to the calculation of the effective dose of biliary drainage. (Author)

  20. Optimization of the therapeutic dose of {sup 131}I for thyroid differentiated carcinoma; Otimizacao da dose terapeutica com {sup 131}I para carcinoma diferenciado da tiroide

    Energy Technology Data Exchange (ETDEWEB)

    Lima, Fabiana Farias de

    2002-09-01

    I-131 thyroid cancer therapy is based on the strategy of concentrating radioactive iodine in the thyroid tissue, to completetly eliminate thyroid tissue and functioning thyroid cancer metastases remaining after thyroidectomy. In Brazil, fixed activities of {sup 131} I generally are given, sometimes either delivering insufficient activities to ablate all of the remnants, or unnecessarily high activities, with patients remaining in the hospital for some period of time. This investigation proposes a protocol of individualized planning of ablative doses, based on individual patients metabolisms and measured thyroid remnant masses. Simulated thyroid remnants were fabricated in various forms, volumes and activities, and optimum image acquisition parameters were determined using Single-Photon Emission Computed Tomography 9SPECT). Resultant images were evaluated, to determine the apparent volumes and the {sup 131} I concentrations. I-131 metabolism was studied in 9 patients who had undergone thyroidectomies. Their thyroid remnant masses were determined applying the same parameters used in SPECT simulation studies, and the optimum activity for their therapy was calculated and compared to the established fixed activity of 3.7 GBq (100 mCi), which would have normally been assigned. Background subtraction using the method of percent maximum counts, using a value of 67.5%, combined with scatter correction (triple energy window method), was shown to be optimum for SPECT quantification of volumes between 3-10 ml. Errors in the method were below 9% for sources with regular geometries and around 11% for sources with irregular geometries. In the patient studies, it was observed that 78% of patients could have received reduced activities of {sup 131} (from 0.8-3-2. GBq (20-87 nCi). In addition, 33% of these patients could have received low enough activities to have discharged from the hospital, using an individualized administration scheme. This could also have resulted in a dose

  1. TASA DE RENDIMIENTO DE CAPITAL DE COLOMBIA PARA EL PERIODO ENTRE 1990 Y 2001

    OpenAIRE

    Ana María Tribín Uribe

    2006-01-01

    Arnold Harberger en 1969 estimó la tasa de rendimiento de capital para Colombia. En su investigación desarrolló una metodología para calcular las variables relevantes que se necesitan para estimarla. Este trabajo replica la metodología de Harberger con datos recientes y encuentra el costo de oportunidad del capital para tres escenarios diferentes. En el primer escenario se toman los datos de las Cuentas Nacionales y de las Naciones Unidas y se desarrolla la metodología de Harberger, los resul...

  2. Formas de adubação e doses de uréia para mudas clonais de cacau cultivadas em substrato Forms and doses of urea to fertilize clonal cocoa tree cuttings cultivated in substrate

    Directory of Open Access Journals (Sweden)

    José Olimpio de Souza Júnior

    2008-12-01

    Full Text Available O N é o nutriente mais demandado pelas plantas. Contudo, para produção de mudas enraizadas de cacaueiro em substratos e sob irrigação freqüente não existem estudos de calibração de adubação nitrogenada. Os objetivos deste trabalho foram comparar a eficiência das adubações no substrato e foliar com uréia para mudas clonais de cacau e definir doses recomendáveis e nível crítico foliar de N. O experimento foi instalado em viveiro de produção de mudas do Instituto Biofábrica de Cacau, em Ilhéus, Bahia, em julho de 2006, envolvendo 10 tratamentos (duas formas de adubação, combinadas com cinco doses de uréia, em blocos casualizados, com quatro repetições. A parcela útil constituiu-se de 12 mudas clonais de cacaueiro cultivadas em tubetes, contendo 288 cm³ de substrato (50 % de fibra de coco e 50 % de Plantmax®. O substrato foi corrigido com 3,20 kg m-3 de calcário e adubado com 2,68 kg m-3 de superfosfato simples. Os tratamentos foram aplicados entre o 82º até o 138º dia, com as seguintes doses semanais de N: 0, 20, 40, 60 e 80 mg dm-3 via substrato e 0,0; 2,25; 4,5; 9,0; e 13,5 g L-1 via foliar. Em todos os tratamentos, fez-se a adubação complementar com P, K, S, Zn e B via substrato. Aos 145 dias, as plantas foram colhidas, sendo avaliados: diâmetro da haste principal, altura, área foliar, matéria seca da parte aérea (MSPA, teor de nutrientes na folha diagnóstica e conteúdo de nutrientes na parte aérea. As variáveis biométricas e nutricionais responderam aos tratamentos. A adubação via substrato proporcionou produção máxima superior à adubação foliar, para MSPA, altura e área foliar. As doses recomendáveis de N, calculadas para obtenção de 99 % da produção máxima, variaram de acordo com a variável biométrica de 43 a 76 mg dm-3 para adubação via substrato e de 9,1 a 11,7 g L-1 para adubação foliar. O nível crítico foliar de N, para obtenção de 99 % da produção máxima da MSPA

  3. Development of methodology for assessment of absorbed dose and stopping power for low energy conversion electrons; Desenvolvimento de uma metodologia para estimativa da dose absorvida e do poder de freamento para eletrons de conversao de baixa energia

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, Ivan Pedro Salati de

    1995-08-01

    The evaluation of absorbed dose in the case of external and internalcontamination due to radionuclides is sometimes hard, because of the difficulties in the assessment of the absorbed dose caused by electrons with energy less than 100 KeV in mucous membrane. In this work, a methodology for assessment of absorbed dose and stopping power in VYNS (co-polymer of polivinyl chloride - acetate) absorbers, for the 62.5 KeV and 84-88 KeV energy {sup 109} Cd conversion electrons, working with a 4 {pi} proportional pressurized detector, is presented. In order to assure the reproducibility of measurement conditions, one of the detector halves has been used to obtain a spectrum of a thin {sup 109} Cd source, without absorber. The other half of the detector was used in concomitance to obtain spectra with different thicknesses if absorber. The absorbed energy was obtained subtracting each spectrum with absorber from the spectrum without absorber, which were stored in a microcomputer connected to signal processing systems by ACE type interface. The VYNS weight and thickness were evaluated using common radionuclide metrology procedures. As VYNS has characteristics similar to a tissue equivalent material, the results obtained are consistent with dosimetric concepts and have a good agreement with those of the literature. (author)

  4. Modelos para estimar consumo e exigências nutricionais para poedeiras comerciais

    OpenAIRE

    Palma Bendezu, Hilda Cristina [UNESP

    2016-01-01

    O objetivo deste trabalho foi elaborar um modelo para calcular as ingestões de aminoácidos e energia para a fase de maturação sexual e produção de ovos. As exigências de energia, aminoácidos e consumo de ração foram calculados pelo método fatorial, considerando na fase de maturação sexual a quantidade de nutrientes requerida para mantença e a quantidade de nutrientes necessários para crescimento e deposição de nutrientes corporais em cada componente do corpo (ovário, oviduto, corpo livre de ...

  5. Propuesta de implementación de un modelo de calidad para la selección de software base para servidores.

    OpenAIRE

    Espinel Mena, Gonzalo Patricio; Montaluisa Yugla, Franklin Javier

    2012-01-01

    La propuesta de implementación plantea la utilización de un modelo de calidad estructurado para ayudar a resolver el problema de adquirir paquetes de software de base que encajen normalmente dentro de un entorno organizacional. El modelo de calidad estructurado para un dominio de un paquete dado proporcionará una taxonomía de características de software de calidad, y métricas para calcular su valor. El modelo de calidad se basa la norma ISO/IEC 9126 de la ISO (Organización Internacional de No...

  6. Uma ferramenta para planejamento de estudos para concursos

    Directory of Open Access Journals (Sweden)

    Leonardo Pimentel

    2015-11-01

    Full Text Available De acordo com a constituição brasileira, a única forma de se tornar um empregado do governo é passar em um concurso público. O exame de conhecimento do cargo é um dos componentes mais importantes de um concurso. Estudar para esse exame é uma tarefa que requer planejamento. Um meio de obter um bom planejamento é construir uma grade de horários que relacione as matérias a serem estudadas com os respectivos horários disponíveis para o estudo. Esse tipo de problema se assemelha bastante à gerência de projetos, em que se procura estabelecer a distribuição das atividades ao longo do tempo disponível. Assim, torna-se interessante explorar a dinâmica de estudos para concursos como um projeto. O presente trabalho apresenta a ferramenta de apoio ao estudos - Passe-me, baseada no ciclo PDCA (do inglês, Plan-Do-Check-Act. Por se tratar de uma ferramenta web, o tempo de resposta para produzir uma grade de estudos é fundamental. A ferramenta faz uso de algoritmo genético para calcular a grade de horários priorizando a velocidade de resposta. A ferramenta foi avaliada em diferentes cenários de uso e obteve desempenho satisfatório durante a produção da grade de estudos.

  7. Mapping of isoexposure curves for evaluation of equivalent environmental doses for radiodiagnostic mobile equipment; Mapeamento de curvas de isoexposicao para avaliacao de equivalente de dose ambiente para equipamentos moveis de radiodiagnostico

    Energy Technology Data Exchange (ETDEWEB)

    Bacelar, Alexandre, E-mail: abacelar@hcpa.ufrgs.b [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil). Hospital de Clinicas. Setor de Fisica Medica e Radioprotecao; Andrade, Jose Rodrigo Mendes, E-mail: jose.andrade@santacasa.tche.b [Irmandade da Santa Casa de Misericordia de Porto Alegre, RS (Brazil). Servico de Atencao a Saude e Qualidade de Vida; Fischer, Andreia Caroline Fischer da Silveira; Accurso, Andre; Hoff, Gabriela, E-mail: andreia.silveira.001@acad.pucrs.b, E-mail: andre.accurso@acad.pucrs.b [Pontificia Univ. Catolica do Rio Grande do Sul (PUC/RS), Porto Alegre, RS (Brazil). Grupo de Experimentacao e Simulacao Computacional em Fisica Medica

    2011-10-26

    This paper generates iso exposure curves in areas where the mobile radiodiagnostic equipment are used for evaluation of iso kerma map and the environment equivalent dose (H{sup *}(d)). It was used a Shimadzu mobile equipment and two Siemens, with non anthropomorphic scatter. The exposure was measured in a mesh of 4.20 x 4.20 square meter in steps of 30 cm, at half height from the scatterer. The calculation of H{sup *}(d) were estimated for a worker present in all the procedures in a period of 11 months, being considered 3.55 m As/examination and 44.5 procedures/month (adult UTI) and 3.16 m As/examination and 20.1 procedure/month (pediatric UTI), and 3.16 m As/examination and 20.1 procedure/month (pediatric UTI). It was observed that there exist points where the H{sup *}(d) was over the limit established for the free area inside the radius of 30 cm from the central beam of radiation in the case of pediatric UTI and 60 cm for adult UTI. The points localized 2.1 m from the center presented values lower than 25% of those limit

  8. Adesao ao guia alimentar para populacao brasileira

    Directory of Open Access Journals (Sweden)

    Eliseu Verly Junior

    2013-12-01

    Full Text Available OBJETIVO : Analisar a adesão ao Guia Alimentar para População Brasileira. MÉTODOS : Amostra composta por participantes do Inquérito de Saúde de São Paulo (n = 1.661 que preencheram dois recordatórios de 24 horas. Foi utilizado modelo bivariado de efeito misto para a razão entre o consumo de energia do grupo de alimentos e o consumo calórico total. A razão estimada foi utilizada para calcular o percentual de indivíduos com consumo abaixo ou acima da recomendação. RESULTADOS : Pelo menos 80,0% da população consome abaixo do recomendado para: leite e derivados; frutas e sucos de frutas; e cereais, tubérculos e raízes; aproximadamente 60,0% para legumes e verduras; 30,0% para feijões; e 8,0% para carnes e ovos. Adolescentes apresentaram a maior inadequação para legumes e verduras (90,0%, e o estrato de maior renda foi associado à menor inadequação para óleos, gorduras e sementes oleaginosas (57,0%. CONCLUSÕES : Foi observado consumo inadequado dos grupos de alimentos relacionados com aumento do risco de doenças crônicas.

  9. Baixas doses de misoprostol vaginal (12,5 versus 25 mcg para indução do parto a termo Low-dose vaginal misoprostol (12.5 versus 25 µg for induction of labor at term

    Directory of Open Access Journals (Sweden)

    Francisco Airton Rangel Filho

    2007-12-01

    Full Text Available OBJETIVO: comparar a efetividade de baixas doses de misoprostol vaginal (12,5 versus 25 mcg para indução do trabalho de parto. MÉTODOS: ensaio clínico controlado, randomizado, duplo-cego, realizado entre maio de 2005 e abril de 2006. Foram incluídas 62 gestantes com gravidez a termo, membranas íntegras, que necessitaram de indução do parto. Foi administrado 25 mcg (32 ou 12,5 mcg de misoprostol (30, a cada quatro horas, até, no máximo, oito doses. Estudaram-se o tipo de parto, tempo entre o início da indução e o parto, complicações perinatais e efeitos maternos adversos. As variáveis de controle foram idades materna e gestacional, paridade e índice de Bishop. Os testes estatísticos utilizados foram cálculos de médias, desvios padrão e teste t de Student (variáveis numéricas contínuas, c² (variáveis categóricas e Mann-Whitney (variáveis discretas. RESULTADOS: não houve diferença significante entre o Grupo de 12,5 e 25 mcg em relação ao intervalo de tempo entre a primeira dose e o parto (1.524 minutos versus 1.212 minutos, p=0,3, na freqüência de partos vaginais (70 versus 71,8%, p=0,7, no escore de Apgar inferior a sete ao quinto minuto (3,3 versus 6,25%, p=0,5 e na freqüência de taquissistolia (3,3 versus 6,2%, p=0,5. A média da dose total administrada de misoprostol foi significativamente maior no Grupo de 25 mcg (40 versus 61,2 mcg, p=0,03. CONCLUSÕES: misoprostol vaginal na dose de 12,5 mcg foi eficiente, com efeitos colaterais semelhante, à dose de 25 mcg de misoprostol vaginal, para indução do parto a termo.PURPOSE: to compare the effectiveness of low doses of vaginal misoprostol (12.5 versus 25 µg for induction of labor. METHODS: a double-blind, randomized, controlled clinical trial was performed in Santa Casa de Misericórdia de Sobral, from May 2005 to April 2006. Sixty-two term pregnant women, with intact membranes and with indication for labor induction, were included. They randomly received 25

  10. Validación de un modelo empírico para calcular, mediante laser y fotodiodo, la potencia en función de la distancia para un blanco difusor

    OpenAIRE

    Blázquez Campo, Pablo

    2012-01-01

    Este proyecto fin de carrera se centra en un estudio teórico y experimental de un sistema de emisión/recepción, formado por láser y fotodiodo, con el objetivo de validar un modelo empírico que describa el comportamiento de un blanco difusor iluminado con un haz colimado y describa la potencia recibida en función de la distancia con el punto de reflexión. A partir de los resultados experimentales, obtenidos y procesados mediante un software de aplicación general (Matlab) hallaremos la ecuación...

  11. Efeito de baixas doses de irradiação nos carotenóides majoritários em cenouras prontas para o consumo Effect of low doses of irradiation on the carotenoids in read-to-eat carrots

    Directory of Open Access Journals (Sweden)

    Keila S. Cople Lima

    2004-06-01

    Full Text Available O presente estudo teve como objetivo avaliar o efeito das baixas doses da radiação gama na concentração de carotenóides totais, alfa e beta-caroteno em cenouras minimamente processadas, durante a vida-útil. As cenouras são as principais fontes de carotenóides provitamínicos A (alfa e beta-caroteno de origem vegetal. De acordo com a Pesquisa de Orçamento Familiar (POF realizada na região Sudeste do Brasil, no grupo de raízes e tubérculos a cenoura é amplamente consumida. A estabilidade dos carotenóides varia grandemente durante o processamento e o armazenamento, dependendo de sua estrutura, temperatura, oxigênio, luz, umidade, atividade de água e presença de ácidos e metais antioxidantes e pró-oxidantes. As cenouras minimamente processadas neste experimento foram manualmente descascadas, lavadas, cortadas mecanicamente, acondicionadas em embalagens com atmosferas modificadas de 5% O2 / 10% CO2 e 21% O2 (ar sintético, tratadas com radiação ionizante gama, fonte de césio, nas doses de 0,25, 0,50, 0,75 e 1,00kGy, e armazenadas a 5°C durante 24 dias. Os carotenóides totais foram quantificados por espectrofotometria a 449nm. Para a determinação de alfa e beta-caroteno utilizou-se cromatografia líquida de alta eficiência (CLAE. Os diferentes tratamentos e o grupo controle foram, também, avaliados através das análises de cor e voláteis, por cromatografia gasosa/espectrometria de massas associada à microextração em fase sólida (CG-EM/MEFS, para estudar as perdas dos carotenóides durante o processamento.This study aims was to evaluate the effect of low doses of gamma radiation on the total carotenoids, alpha and beta-carotene content in minimally processed carrots, during the shelflife. Carrots are the mains vegetable source of carotenoids provitamin A (alpha and beta-carotene. According to the Family Budget Survey (FBS carried out in the Brazilian Southeast, within the roots and tubers group, carrots are widely

  12. Comportamento da dose glandular versus contraste do objeto em mamografia: determinação de formalismo semi-empírico para diferentes combinações alvo-filtro Behavior of subject contrast versus glandular dose in mammography: determination of a semi-empirical formalism for different target-filter combinations

    Directory of Open Access Journals (Sweden)

    Gabriela Hoff

    2006-06-01

    Full Text Available OBJETIVO: Verificar o efeito da mudança no contraste do objeto, tempo de exposição e dose de radiação quando diferentes espessuras de filtração de molibdênio (Mo e ródio (Rh são empregadas em mamógrafos. MATERIAIS E MÉTODOS: Realizaram-se medidas da exposição na entrada da pele com uma câmara de ionização para diferentes espessuras para os filtros de Mo e Rh. Para determinar a dose glandular média foi utilizado simulador de BR12 (50% tecido adiposo e 50% tecido glandular de diferentes espessuras (4 cm e 8 cm. Energias na faixa de 24 kVp a 34 kVp foram empregadas e filmes Kodak MinR 2000 foram utilizados. RESULTADOS: Os resultados evidenciaram dados de contraste do objeto, dose glandular e tempo de exposição para diferentes espessuras de filtros adicionais e diferentes tensões. Esses dados indicaram aumento nos valores de contraste do objeto e tempo de exposição, com o aumento da espessura dos filtros. A dose glandular apresentou comportamento com diferentes tendências para cada caso analisado. Equações foram definidas para possibilitar a estimativa do contraste do objeto, dose glandular e tempo de exposição para os casos estudados. CONCLUSÃO: Os resultados possibilitaram a estimativa de equações que auxiliam na verificação do comportamento do contraste do objeto e da dose glandular para simuladores com espessura de 4 cm e 8 cm e para os filtros de Rh e Mo. Dessa forma, torna-se possível estimar a figura de mérito (razão entre o contraste do objeto e a dose glandular, podendo auxiliar na análise da relação risco-benefício dos casos estudados.OBJECTIVE: Our purpose was to verify the effect of changes in subject contrast, exposure time and radiation dose when different thicknesses of molybdenum (Mo and rhodium (Rh filters are used in mammography equipments. MATERIALS AND METHODS: Entrance skin exposure measurements were performed with an ionization chamber for different thicknesses of Mo and Rh filters

  13. Estudo comparativo entre uma e duas doses efetivas (DE95 de rocurônio para a intubação traqueal Estudio comparativo entre una y de los dosis efectivas (DE95 de rocuronio para la intubación traqueal A comparative study between one and two effective doses (ED95 of rocuronium for tracheal intubation

    Directory of Open Access Journals (Sweden)

    Luciano Carlos Gomes de Miranda

    2008-06-01

    Full Text Available JUSTIFICATIVA E OBJETIVOS: Os bloqueadores neuromusculares (BNM são fármacos utilizados para produzir relaxamento da musculatura esquelética e facilitar a intubação traqueal (IT. A literatura descreve como sendo necessárias duas doses efetivas (DE95 o ideal para a IT. O rocurônio é um BNM não-despolarizante do tipo esteróide, sintético e de duração intermediária. O objetivo desse estudo foi avaliar e comparar as condições de intubação traqueal (IT, utilizando uma e duas doses efetivas (DE95 do rocurônio, seguindo os critérios da Conferência de Consenso de Copenhague. MÉTODO: Foram avaliados 60 pacientes divididos aleatoriamente em dois grupos de 30, de ambos os sexos, idades entre 20 e 60 anos, estado físico ASA I e II, Mallampati 1 e 2, índice de massa corporal (IMC JUSTIFICATIVA Y OBJETIVOS: Los bloqueadores neuromusculares (BNM son fármacos utilizados para producir el relajamiento de la musculatura esquelética y facilitar la intubación traqueal (IT. La literatura describe que son necesarias de los dosis efectivas (DE95 lo ideal para la IT. El rocuronio es un BNM no despolarizador del tipo esteroide, sintético y de duración intermedia. El objetivo de este estudio fue evaluar y comparar las condiciones de intubación traqueal (IT, utilizando una y de los dosis efectivas (DE95 del rocuronio, secundando los criterios de la Conferencia de Consenso de Copenhague. MÉTODO: Se estudiaron 60 pacientes divididos aleatoriamente en 2 grupos de 30, de ambos sexos, edades entre 20 y 60 años, estado físico ASA I y II, Mallampati 1 y 2, índice de masa corporal (IMC BACKGROUND AND OBJECTIVES: Neuromuscular blockers (NMB are used to induce relaxation of skeletal muscles and facilitate tracheal intubation (TI. According to the literature, two effective doses (ED95 of NMB are ideal for TI. Rocuronium is a steroid-type, synthetic, non-depolarizing neuromuscular blocker of medium duration. The objective of this study was to evaluate

  14. Estimación lineal de los requerimientos nutricionales del NRC para ganado de leche

    Directory of Open Access Journals (Sweden)

    Jorge Elizondo

    2002-01-01

    Full Text Available Se determinaron ecuaciones de regresión lineal para calcular en forma directa los requerimientos nutricionales del ganado de leche (TND, ED, EM, ENL, PC, Ca, P, Vitamina Ay Vitamina D en diferentes etapas fisiológicas: mantenimiento, gestación y producción del ganado de leche. Se utilizó como base la tabla de requerimientos nutricionales del NRC. En todas las ecuaciones se calculó el coeficiente de determinación para conocer el grado de ajuste.

  15. Baixa dose de misoprostol sublingual (12,5 µg para indução do parto Low dose of sublingual misoprostol (12.5 µg for labor induction

    Directory of Open Access Journals (Sweden)

    Daniele Sofia de Moraes Barros Gattás

    2012-04-01

    Full Text Available OBJETIVO: Descrever os resultados maternos e perinatais utilizando 12,5 µg de misoprostol sublingual para indução do parto em gestantes com feto vivo a termo. MÉTODOS: Realizou-se um estudo multicêntrico, tipo ensaio clínico, aberto e não randomizado, no período de julho a dezembro de 2009. Foram incluídas 30 gestantes com indicação de indução do parto, a termo, feto vivo, escore de Bishop menor ou igual a seis, apresentação cefálica, peso fetal estimado menor que 4.000 g e índice de líquido amniótico maior que cinco. Foram excluídas mulheres com cicatriz uterina, alteração da vitalidade fetal, anomalias congênitas, gestação múltipla, restrição de crescimento intrauterino, hemorragia genital e contraindicações ao parto vaginal. O comprimido de misoprostol sublingual 12,5 µg foi administrado a cada seis horas, até o início do trabalho de parto, máximo de oito doses. RESULTADOS: O trabalho de parto foi induzido satisfatoriamente em 90% das gestantes. As médias dos intervalos entre a primeira dose e o início das contrações uterinas e o parto foram de 14,3±11,7 horas e 25,4±13 horas, respectivamente. A frequência de parto vaginal foi de 60%. A taquissistolia ocorreu em duas gestantes, sendo revertida em ambos os casos sem necessitar de cesariana. A eliminação de mecônio foi observada em quatro pacientes e o escore de Apgar foi menor que sete no quinto minuto em um recém-nascido. CONCLUSÃO: Os desfechos maternos e perinatais foram favoráveis depois da indução do parto com misoprostol sublingual na dose de 12,5 µg a cada seis horas. No entanto, são necessários ensaios clínicos controlados comparando esse esquema posológico com outras doses e vias de administraçãoPURPOSE: To describe the maternal and perinatal outcomes after the use of 12.5 µg of sublingual misoprostol for labor induction in women with term pregnancy and a live fetus. METHODS: We conducted a multicenter, open and non

  16. DOSE NÃO USUAL DE VARFARINA PARA ALCANÇAR RNI TERAPÊUTICA EM UMA CRIANÇA DE QUATRO MESES: FATORES DE RISCO NÃO GENÉTICOS AINDA SÃO UM DESAFIO

    Directory of Open Access Journals (Sweden)

    Lucas Miyake Okumura

    Full Text Available RESUMO Objetivo: Descreve se uma criança do sexo feminino, com quatro meses de idade, que necessitou de varfarina 0.7 mg/kg/dia (5 mg. Discutem se os fatores de risco clinicamente relevantes para prescrição de altas doses do anticoagulante em crianças. Descrição do caso: Em novembro de 2015, uma criança de 5 kg (36 semanas, pré termo foi admitida no pronto atendimento por status epilepticus e febre. Diazepam, fenitoína e ceftriaxona foram prescritos inicialmente. A pesquisa no líquor revelou presença de sete leucócitos, 150 mg/dL de proteínas, 1 mg/dL de glucose e cocos Gram positivos. Em tomografia de crânio, foram observados sinais hipodensos em cerebelo, lobo temporal e núcleos de base à esquerda, sugerindo vasculite infecciosa por meningite pneumocócica. Após o quadro agudo da encefalite, a criança desenvolveu uma trombose e necessitou de anticoagulação com enoxaparina e, posteriormente, com varfarina. Dez dias de tratamento com o segundo fármaco foram necessários para atingir relação normalizada internacional (RNI terapêutica, tendo sido realizados cinco ajustes de dose desde a primeira prescrição de varfarina. Comentários: Os fatores de risco determinantes para necessidade de doses maiores de varfarina foram idade e uso de nutrição enteral. Fenobarbital e prednisona também podem ter contribuído para o uso de uma das maiores doses de varfarina já relatadas na literatura. A despeito da importância dos testes de polimorfismo genético, os pediatras devem estar atentos para identificar os fatores que contribuem para a prescrição de maiores doses de varfarina, de forma a minimizar os riscos de trombose, reduzindo os custos com internação e exames laboratoriais.

  17. MÉTODOS INDIRECTOS PARA LA ESTIMACIÓN DE POBLACIONES OCULTAS

    Directory of Open Access Journals (Sweden)

    Rocío Lorenzo Ortega

    2017-01-01

    Full Text Available En determinadas situaciones podemos encontrar dificultades a la hora de calcular prevalencias en algunas poblaciones. Es el caso de personas que tienen comportamientos que son difíciles de identificar debido a que pueden estar sancionados socialmente o ser ilegales. Es lo que llamamos poblacio - nes ocultas. Este artículo proporciona una revisión crítica de los métodos más utilizados para calcular el tamaño de una población de difícil acceso. Se trata de métodos indirectos, que estiman la prevalencia de una población oculta basándose en fuentes de datos incompletas. Se exponen diferentes métodos, cada uno de ellos tiene diferentes indicaciones para ser utilizado, dependiendo de los datos de los que dispongamos. Además, precisan de una serie de requisitos para poder ser aplicados y cada uno está expuesto a di - ferentes tipos de sesgos. Por estos motivos, hay que valorar correctamente los datos disponibles para aplicar el método más preciso, y si fuese posible, utilizar simultáneamente varios métodos para poder comparar los resultados obtenidos, además de valorar críticamente los resultados y comprobar si se ajustan a la realidad.

  18. Proyecto básico de cimentación de gravedad para eólica offshore mediante cajones cuadrados construidos en dique flotante

    OpenAIRE

    García Monroy, Sergio

    2014-01-01

    RESUMEN: Planteamiento. Se ha estudiado la posibilidad de construcción de un parque de molinos para energía eólica offshore. Para ello se ha comenzado con unos datos de partida que incluían condiciones metaoceánicas básicas, estudio geológico simple y un predimensionamiento. Este predimensionamiento consistía en un cajón hormigonado en dique flotante de base octogonal. A partir de lo mencionado se han ampliado los estudios marinos y geológicos para poder calcular los esfuerzos, mediante formu...

  19. Modelación de la asimetría y curtosis condicionales: una aplicación VaR para series colombianas

    OpenAIRE

    Andrés Eduardo Jiménez Gómez; Luis Fernando Melo Velandia

    2014-01-01

    Las metodologías tradicionales utilizadas para calcular el valor en riesgo y el valor en riesgo condicional usualmente modelan el primer y segundo momento de las series, suponiendo que el tercer y cuarto momento son constantes. En este documento se utiliza la metodología de Hansen [1994] para modelar los primeros cuatro momentos de la serie, en particular, se usan varias formas paramétricas para modelar la asimetría y curtosis. Las medidas de VaR y CVaR tradicionales y las propuestas son calc...

  20. Utilização de máquina fotográfica digital (multi-burst) para aulas experimentais de cinemática - queda livre

    OpenAIRE

    Corveloni,E.P. Moraes; Gomes,E.S.; Sampaio,A.R.; Mendes,A.F.; Costa,V.L.L.; Viscovini,R.C.

    2009-01-01

    Nesse trabalho foi utilizada uma máquina fotográfica digital, com a função multi-burst (fotos tiradas em sequência) para analisar o movimento de queda livre e com os dados obtidos calcular o valor da aceleração da gravidade local. Para avaliar o experimento, foi também calculado um valor teórico para aceleração da gravidade local. Comparado com o obtido experimentalmente, foi possível observar um desvio pequeno, o que mostrou que a máquina fotográfica digital pode ser uma boa ferramenta pedag...

  1. Preparación de un plan muestreo para la auditoría de proyectos de desarrollo tecnológico

    Directory of Open Access Journals (Sweden)

    Luís Antonio Garavito Herrera

    2004-01-01

    Full Text Available Se presenta un plan de muestreo para auditoría e interventoría de proyectos de desarrollo tecnológico. Se plantea un esquema general de los proyectos relevantes del muestreo, cuáles deben tenerse en cuenta, un procedimiento para determinar el tamaño y la selección de la muestra y calcular algunas estadísticas inferenciales acerca de la población muestreada. Es una combinación de técnicas tradicionales de muestreo estadístico y muestreo para aceptación en control de calidad.

  2. Validation of dose-response curve of CRCN-NE - Regional Center for Nuclear Sciences from Northeast Brazil for {sup 60}Co: preliminary results; Validacao da curva dose-resposta do CRCN-NE para {sup 60}Co: resultados preliminares

    Energy Technology Data Exchange (ETDEWEB)

    Mendonca, Julyanne C.G.; Mendes, Mariana E.; Hwang, Suy F.; Lima, Fabiana F. [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil); Santos, Neide, E-mail: july_cgm@yahoo.com.br [Universidade Federal de Pernambuco (CCB/UFPE), Recife, PE (Brazil). Departamento de Genetica

    2014-07-01

    The cytogenetic study has the chromosomal alterations as biomarkers in absorbed dose estimation by the body of individuals involved in exposure to ionizing radiation by interpreting a dose response calibration curve. Since the development of the technique to the analysis of data, you can see protocol characteristics, leading the International Atomic Energy Agency indicate that any laboratory with intention to carry out biological dosimetry establish their own calibration curves. The Biological Dosimetry Laboratory of the Centro Regional de Ciencias Nucleares (CRCN-NE/CNEN), Brazil, recently established the calibration curve related to gamma radiation ({sup 60}Co). Thus, this work aimed to start the validation of this calibration curve from samples of three different blood donors which were irradiated with an absorbed known single dose of 1 Gy. Samples were exposed to {sup 60}Co source (Glaucoma 220) located in the Department of Nuclear Energy (DEN/UFPE). After fixation with methanol and acetic acid and 5% Giemsa staining, the frequency of chromosomal alterations (dicentric chromosomes, acentric rings and fragments) were established from reading of 500 metaphases per sample and doses were estimated using Dose Estimate program. The results showed that, using the dose-response curve calibration for dicentrics, the dose absorbed estimated for the three individuals ranged from 0.891 - 1,089Gy, taking into account the range of confidence of 95%. By using the dose-response curve for dicentrics added to rings and for the same interval of confidence the doses ranged from 0,849 - 1,081Gy. Thus, the estimative encompassed known absorbed dose the three individuals in confidence interval of 95%. These preliminary results seems to demonstrate that dicentric dose-response curves and dicentrics plus rings established by CRCN-NE / CNEN are valid for dose estimation in exposed individuals. This validation will continue with samples from different individuals at different doses.

  3. Radiochromic film use to record dose profile variations in chest CT scan; Utilizacao do filme radiocromico para registro da variacao do perfil de dose em varredura de TC de torax

    Energy Technology Data Exchange (ETDEWEB)

    Mourao, Arnaldo P.; Santana, Priscila C., E-mail: aprata@des.cefetmg.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Departamento de Engenharia Nuclear; Silva, Teogenes A. da; Alonso, Thessa C. [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2015-12-15

    The CT scans generate higher doses in patients than those caused by other types of diagnostic radiology using the attenuation of X-ray beams. Technological advances have increased the clinical applications of computed tomography (CT) and consequently the demand for these exams. Dose reduction strategies are difficult to implement because of a lack of proper guidance on the CT scanning. However, CT offers the possibility of adjusting the image acquisition parameters according to the patient physical profile and the diagnostic application for which it is intended to scan. Knowledge of the dose distribution is important when thinking about varying the acquisition parameters to reduce the dose. In this work was used a PMMA chest phantom to observe the dose deposition in 5 areas. Radiochromic film strips were placed inside the chest phantom, in peripheral and in the central region. The phantom was placed in the scanner isocenter and it was performed the irradiation of its central region using a chest acquisition protocol. After the phantom CT scan the radiochromic film strips were processed for obtaining digital images. Digital images were reworked to obtain the dose variation profiles for each position. The results showed a wide variation in absorbed dose by the phantom, either within a same position along the length of the film strip, as in the comparison among the five regions which the strips are placed. In this second case the dose variations were even greater. (author)

  4. Uncertainties associated to the using of alanine/EPR for the dose interval in the radiotherapy; Incertezas associadas na utilizacao da alanina/RPE para o intervalo de dose da radioterapia

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues Junior, O.; Campos, L. L. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2004-07-01

    The High Doses Laboratory of IPEN is developing a dosimetric system for high doses based on Electron Paramagnetic Resonance (EPR) of free radical radiation induced on alanine. The objective of this work is to present the efforts towards to improve the measure accuracy for doses in the range between 1-10 Gy. This system could be used as reference by radiotherapy services, as much in the quality control of the equipment, as for routine accompaniment of more complex handling where the total doses can reach some grays. The main problem for routine implantation is the calibration and the traceability of the system and many errors sources affects the accuracy of the measurements. In this work are discussed same aspects related on the uncertainty evaluation associated with high dose measurement using alanine and EPR. (author)

  5. Primary and scattering contributions to beta scaled dose point kernels by means of Monte Carlo simulations; Contribuicoes primaria e espalhada para dosimetria beta calculadas pelo dose point kernels empregando simulacoes pelo Metodo Monte Carlo

    Energy Technology Data Exchange (ETDEWEB)

    Valente, Mauro [CONICET - Consejo Nacional de Investigaciones Cientificas y Tecnicas de La Republica Argentina (Conicet), Buenos Aires, AR (Brazil); Botta, Francesca; Pedroli, Guido [European Institute of Oncology, Milan (Italy). Medical Physics Department; Perez, Pedro, E-mail: valente@famaf.unc.edu.ar [Universidad Nacional de Cordoba, Cordoba (Argentina). Fac. de Matematica, Astronomia y Fisica (FaMAF)

    2012-07-01

    Beta-emitters have proved to be appropriate for radioimmunotherapy. The dosimetric characterization of each radionuclide has to be carefully investigated. One usual and practical dosimetric approach is the calculation of dose distribution from a unit point source emitting particles according to any radionuclide of interest, which is known as dose point kernel. Absorbed dose distributions are due to primary and radiation scattering contributions. This work presented a method capable of performing dose distributions for nuclear medicine dosimetry by means of Monte Carlo methods. Dedicated subroutines have been developed in order to separately compute primary and scattering contributions to the total absorbed dose, performing particle transport up to 1 keV or least. Preliminarily, the suitability of the calculation method has been satisfactory, being tested for monoenergetic sources, and it was further applied to the characterization of different beta-minus radionuclides of nuclear medicine interests for radioimmunotherapy. (author)

  6. Un modelo matemático para calcular el costo de manutención de un estudiante de la facultad de ingeniería (u.na.m.

    Directory of Open Access Journals (Sweden)

    Juan Carlos Michalus

    2006-07-01

    Full Text Available Este artículo presenta los resultados de una investigación cuyo objetivo fue encontrar un modelo matemático que permita determinar con cierto grado de precisión el costo mensual que debe afrontar un alumno que estudia en la Facultad de Ingeniería de la Universidad Nacional de Misiones. Se estudiaron los componentes del costo de manutención, estableciendo cuáles son los más significativos y finalmente se construyó un modelo matemático utilizando regresión lineal múltiple considerando los factores principales en base a regresores cualitativos. Se realizaron pruebas estadísticas que arrojaron resultados satisfactorios poniendo de manifiesto la bondad del modelo. Se desarrolló un software de aplicación sencillo de utilizar, el que se puso a disposición de la comunidad a través de la página web de la Facultad de Ingeniería. This paper presents the results of a research whose objective was to find a mathematical model in order to determine, with a certain degree of precision, the monthly cost which should be afforded by a student of Facultad de Ingeniería, Universidad Nacional de Misiones (FI-U.Na.M.. The cost of living was analysed determining the most significant components. Finally a mathematical model was built. For this purpose a Multiple Lineal Regression was used. Statistical tests were made which showed positive results. A user-friendly software was developed to allow the community to consult on the Web Page of  FI-U.Na.M.

  7. Three L-subshells atomic model to compute counting efficiency of electron-capture nuclides; Modelo con tres subcapas L para calcular la eficiencia de recuento de nucleidos que se desintegran por captura electronica

    Energy Technology Data Exchange (ETDEWEB)

    Grau, A.; Arcos, J. M. los

    1986-07-01

    The present paper develops a three L-subshell a and K, M-a hells atomic model in order to obtain the counting efficiency in liquid scintillation counting. Mathematical expressions are given to calculate the probabilities of 264 different atomic rearrangement way so as the corresponding effective energies. This new model will permit to test the influence of the different atomic and nuclear parameters upon the counting efficiency nuclides of low and medium atomic number decaying by electron capture. (Author) 8 refs.

  8. MÉTODO DELPHI EN ESTUDIOS DE PROSPECTIVA TECNOLÓGICA: Una aproximación para calcular el número de expertos y aplicación del coeficiente de competencia experta “K”

    Directory of Open Access Journals (Sweden)

    JHON WILDER ZARTHA SOSSA

    2017-07-01

    Full Text Available This paper deals with the Delphi method, its origins and characteristics. The main aspect to address is to provide information to identify an adequate number of experts in the choice of topics in the applications of the Delphi method in foresight. For that purpose, one Delphi study was evaluated in the period 2012 - 2015 on priority technologies regarding biodegradable packaging in the year 2032. On the results of this study, the incidence of the number of experts was evaluated with 9, 15, 22 and 24 experts. The results highlighted the existence of common core of technologies that were priorities from analysis 9 to 24 experts; regarding the expert competence coefficient "k" the results with the 16 experts with a coefficient "k" greater than or equal to 0.8, in four of the five groups, achieved high agreement percentages in relation to the core group of priority topics.

  9. An multi objective heuristic method for calculating the performance of distribution network with distributed generators; Um metodo heuristico multi-objetivo para calcular o desempenho de redes de distribuicao com geradores distribuidos

    Energy Technology Data Exchange (ETDEWEB)

    Ciric, Rade M.; Padilha, Antonio [UNESP, Ilha Solteira, SP (Brazil)

    2002-07-01

    This paper describes the allocation and the performance of the distributed generators installed in a electric power distribution network, and presents a investigation to determining the impacts of distributed generators integration in power systems and the distribution network global performance.

  10. Proposal of methodology for calculating the degree of impact caused by perturbations recorded in a power transmission system; Proposicao de metodologia para calcular o grau de impacto causado pelas perturbacoes registradas em um sistema eletrico de transmissao

    Energy Technology Data Exchange (ETDEWEB)

    Vianna, E.A.L. [Centrais Eletricas do Norte (ELETRONORTE), Porto Velho, RO (Brazil)], E-mail: elainelimavianna@yahoo.com.br; Lambert-Torres, G.; Silva, L.E.B. da [Universidade Federal de Itajuba (UNIFEI), MG (Brazil)], Emails: germanoltorres@gmail.com, leborges@unifei.edu.br; Rissino, S.; Silva, M.F. da [Universidade Federal de Rondonia (UFRO), Porto Velho, RO (Brazil)], Emails: srissino@gmail.com, felipe@unir.br

    2009-07-01

    Disturbances recorded in a electric power system compromise the quality and continuity energy supply and are measured by means of performance indicators. This article defines the attributes that contribute to increased the severity of disturbances recorded in an Electrical Power Transmission and proposes a methodology for calculating the degree of impact caused each of them. The proposed methodology allows quantification of the impact caused by a disturbance, and its comparison with other disturbance, in one system or distinct systems.

  11. Assessment of radiation doses to the para-aortic, pelvic, and inguinal lymph nodes delivered by image-guided adaptive brachytherapy in locally advanced cervical cancer

    DEFF Research Database (Denmark)

    Mohamed, Sandy M I; Aagaard, Torben; Fokdal, Lars U

    2015-01-01

    PURPOSE: This study evaluated the dose delivered to lymph nodes (LNs) by brachytherapy (BT) and the effect of BT image-guided optimization on the LN dose. METHODS AND MATERIALS: Twenty-five patients with locally advanced cervical cancer were retrospectively analyzed, 16 patients of them had LN...

  12. Proposition for restriction dose levels for occupational exposition in medical practices; Propuesta de niveles de restriccion de dosis para la exposicion ocupacional en las practicas medicas

    Energy Technology Data Exchange (ETDEWEB)

    Callis, Ernesto; Cornejo, Nestor; Lopez, Gladys; Capote, Eduardo; Diaz Bernal, Efren [Centro de Proteccion y Higiene de las Radiaciones, La Habana (Cuba)]. E-mail: ernesto@cphr.edu.cu; Domenech, Haydee

    2001-07-01

    A study was carried out in order to propose restriction levels for occupational exposures in nuclear medicine and teletherapy. The initial data were the annual doses of occupational exposed workers reported by external dosimetry of 23 institutions since 1990 to 1999, which were analyzed by statistical processing to obtain the variation ranges of this magnitude. Dose values corresponding to the 75-percentile were then considered in this study. Simultaneously, a model of the exposure scenarios was used for the estimation of the annual effective doses, this estimation was supported with measurements of dose rates carried out in the institutions. The restriction levels were obtained by multiplying the sum of the annual doses (normal and potential) by a reserve coefficient defined in the present work. The determined restriction levels are in the range of those obtained by other similar studies. (author)

  13. Determination of effective dose for workers hemodynamics service using double dosimetry; Determinacion de la dosis efectiva para los trabajadores del servicio de hemodinamica usando doble dosimetria

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz Lopez, M. A.; Lobato Munoz, M.; Jodar Lopez, C. A.; Ramirez Ros, J. C.; Jerez Sainz, M. I.; Pamos Urena, M.; Carrasco Rodriguez, J. L.

    2013-07-01

    The use of an additional dosimeter at the level of the neck above the lead apron we can provide an indication of the dose in the head (the Crystal dose). In addition, it is possible to combine the two readings of the dosimeter to provide an improved estimate of the effective dose. In the hemodynamics service of our Hospital we have maintained a worker for 3 years with the double dosimetry read monthly. With the readings from these dosimeters will do following algorithms, several estimates of the effective dose to see if, with working conditions that occur in this service, it would be necessary to extend this practice to the rest of the workers to get a better estimation of effective dose. (Author)

  14. Researches, development and characterization of dosimetric materials for monitoring in irradiation processes with high doses; Pesquisa, desenvolvimento e caracterizacao de materiais dosimetricos para monitoramento em processos de irradiacao com doses altas

    Energy Technology Data Exchange (ETDEWEB)

    Galante, Ana Maria Sisti

    2003-07-01

    Dosimetric materials that can be produced in Brazil with material acquired in the national market to replace the imported dosimeters used in radiation processing were developed in this work. Mixtures of potassium nitrate and sensitizers compounds as manganese dioxide, barium nitrate and potassium bromide were prepared in the pellet form. Dosimetric characteristics such as dose-response useful range, sensitivity, environmental conditions and dose rate influences were evaluated in {sup 60}Co gamma radiation fields. Dyed polymethylmethacrylate detectors were also produced and its dosimetric characteristics were evaluated. The main characteristics evaluated in this case were: dose response useful range sensitivity, environmental conditions, dose rate influences and radiation energy dependence in gamma radiation fields and accelerated electrons beam of 0.8 to 1.5 MeV. The applied analytic technique was spectrophotometry. The calibration was performed in the irradiation facilities belonging to IPEN and certified by the International Atomic Energy Agency by means of the program IDAS (International Dose Assurance Service ) using the Fricke dosimeter. The mixture of potassium nitrate and manganese dioxide presented the best results and a wide dose range between 200 and 600 kGy. The response of the developed polymethylmethacrylate detectors are similar to the imported detectors and the dose range is characteristic to each detector and depends on the dye added in its formulation. (author)

  15. Caracterização da dose letal mínima por irradiação gama para Penicillium citrinum Characterization of minimum lethal dosis of gama irradiation to Penicillium citrinum

    Directory of Open Access Journals (Sweden)

    A. N. Norberg

    1993-12-01

    Full Text Available O uso das radiações ionizantes na destruição de microrganismos responsáveis pela deterioração de alimentos ou causadores de infecções ou toxinfecções alimentares, constituiu-se aplicação da energia nuclear, para fins verdadeiramente pacíficos. Penicillium citrinum é um fungo produtor de micotoxinas, responsáveis por intoxicações em humanos e animais que se utilizam de alimentos contaminados. Há escassez de informações sobre a resistência do P. citrinum à irradiação gama; assim esta pesquisa objetivou determinar a dose letal por irradiação gama para esse microrganismo. Foram irradiadas 76 suspensões, contendo aproximadamente 100.000 esporos por mililitro, com doses entre 0,2 e 2,2 KGy (KiloGray, sendo os sobreviventes re-irradiados com doses até 3,0 KGy. O fungo foi totalmente destruído com dose de 2,2 KGy. P. citrinum descendentes dos sobreviventes de 2,0 KGy, quando re-irradiados também foram totalmente destruídos com dose de 2,2 KGy. Observou-se um aumento da resistência às doses mais baixas em relação ao fungo não irradiadoThe use of nuclear power through radiation for the destruction of microrganisms which cause food decay, and toxicosis, is specifically for peaceful purposes. Penicillium citrinum is a fungus which produce mycotoxins responsible for intoxication in humans and animals as a result of eating contaminated food. There is little informations on the resistance of P. citrinum to radiation. The objective of this research is to determine the lethal dose of gama radiation for these microrganisms. Seventy six suspensions containing approximately 100,000 spores/ml received a dose of radiation between 0.2 and 2.2 KGy (KiloGray, being one sample still alive re-irradiated with doses up to 3.0 KGy. The fungus were totally destroyed with a 2.2 KGy. Seventy six suspensions containing approximately 100,000 spores/ml received a dose of radiation between 0.2 and 2.2 KGy, being one sample still alive re

  16. Cálculo de un sistema de inyección multifuel para motores Diesel

    OpenAIRE

    PAVÍA PARRA, MARC

    2015-01-01

    [ES] Los nuevos diseños de motores buscan como estrategia la combinación de propiedades de los combustibles Diesel y gasolina convencionales, por sus ventajas en cuanto a rendimiento y emisiones. El presente proyecto calculará el impacto que estos cambios pueden tener sobre la mezcla combustible-aire, y cómo se quema el combustible en el motor. Para ello se empleará un código de cálculo 1D de chorros, en el cual se definen las condiciones de contorno en el cilindro del motor y se puede predec...

  17. Propuesta numérica para el cálculo generalizado del factor de efectividad

    Directory of Open Access Journals (Sweden)

    Hermes A. Rangel Jara

    1995-01-01

    Full Text Available El presente trabajo desarrolla y pone a prueba una propuesta numérica de tipo generalizado para calcular el factor de efectividad de una pastilla catalítica. La estrategia numérica se elabora a partir del análisis del sistema acoplado de ecuaciones diferenciales, originado de la aplicación de los principios de conservación de masa y energía a los fenómenos de transferencia de masa, calor y de la reacción química, bajo una condición estable.

  18. Aplicación Android para el seguimiento de Cetáceos

    OpenAIRE

    Suárez Vélez, María Fernanda

    2013-01-01

    El propósito del proyecto es desarrollar una aplicación basada en el sistema operativo Android que ofrezca ayuda en el seguimiento de delfines en el mar, mediante el cálculo de la distancia donde aparece el animal. Esto se consigue haciendo uso de la Realidad Aumentada y con el empleo del acelerómetro, la brújula, la cámara y el GPS de la tablet, junto con su altura sobre la superficie del mar y el ángulo de inclinación del dispositivo, que es usado para calcular la distancia ...

  19. Dose response curve of induction of MN in lymphocytes for energies Cs-137; Curva dosis respuesta de induccion de micronucleos en linfocitos para las energias Cs-137

    Energy Technology Data Exchange (ETDEWEB)

    Serna Berna, A.; Alcaraz, M.; Acevedo, C.; Vicente, V.; Fuente, I. de la; Canteras, M.

    2006-07-01

    The determination of the dose-response curve is a crucial step to use the Micronucleus assay in Lymphocytes as a biological dosimeters. The most widely used fitting function is the linear-quadratic function. The coefficients are fitted by calibration data provided by irradiations of blood from healthy donors. In our case we performed the calibration curve corresponding to gamma radiation from Cesium-137 (660 keV). Doses ranged from 0 to 16 Gy. The fitting procedure used was the iteratively re weighted least square algorithm implemented in a Matlab routine. The results of the analysis of our data show that the dose-effect curve does not follow a linear-quadratic curve at high radiation doses, diminishing the quadratic parameters as dose increases. This can be interpreted as a micronucleus saturation effect beyond a certain dose level. We conclude that the MN assay with lymphocytes can be well characterized as a biological dosimeters up to a maximum dose of 4.5 Gy. (Author)

  20. Dose rate range extension of the calibration of dosemeters at LNMRI, Rio de Janeiro, Brazil; Expansao da faixa de taxas de dose para a calibracao de instrumentos de medir radiacao no LNMRI, Rio de Janeiro, Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Cabral, T.S.; Carlos, M.T.; Ramos, M.M.O., E-mail: tschirn@ird.gov.b, E-mail: marcia@ird.gov.b, E-mail: mmoramos@ird.gov.b [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2009-07-01

    The present work has an objective the implantation of a experimental arrange for application of essays of instrument calibration for measurement of low dose rate, which measure rate less than 10 {mu}Sv/h

  1. Radiation doses in mammography as planning parameters for premature breast cancer tracking programs; Doses de radiacao em mamografias como parametros de planejamento para programas de rastreamento do cancer precoce da mama

    Energy Technology Data Exchange (ETDEWEB)

    Souza Ferreira, Rubemar de

    1994-12-31

    Radiation doses are the main parameters applied to the evaluation of mammographic radiological impact. This study, for a sample of 407 women, were analyzed, through the thermoluminescent dosimetry, radiation doses in the surface of skin and glandular absorbed doses for cranio-caudal view. The results show the presence of a large dose range to the same mammographic procedure, which, analyzed enclosed with 585 facilities, suggest be necessary the standardization of the mammographic technique. From that results, with the additive model, the excess of breast cancer (radioinduced) and lifetime loss risk, for age groups between 30 and 70 years were estimated. Is demonstrated that the benefits from dedicated mammography, overcome the relationship among the epidemiological aspects of breast cancer and ionizing radiation as an harmful agent, which may show an important correlation for large exposed populations, point out the importance of the continuous risk and benefit evaluation to the new technologies introduced. (author). 86 refs., 40 figs., 14 tabs.

  2. A reference dosimetric system for dose interval of radiotherapy based on alanine/RPE; Um sistema dosimetrico de referencia para o intervalo de doses da radioterapia baseado na alanina/RPE

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues Junior, Orlando; Galante, Ocimar L.; Campos, Leticia L. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)]. E-mail: rodrijr@net.ipen.br

    2001-07-01

    This work describes the development of a reference dosimetric system based on alanine/EPR for radiotherapy dose levels. Currently the IPEN is concluding a similar system for the dose range used for irradiation of products, 10-10{sup 5} Gy. The objective of this work is to present the efforts towards to improve the measure accuracy for doses in the range between 1-10 Gy. This system could be used as reference by radiotherapy services, as much in the quality control of the equipment, as for routine accompaniment of more complex handling where the total doses can reach some grays. The system uses alanine as detector and electronic paramagnetic resonance - EPR as measure technique. To reach accuracy better than 5% mathematical studies on the best optimization of the EPR spectrometer parameters and methods for the handling of the EPR sign are discussed. (author)

  3. Implementation of three-dimensional planning in brachytherapy of high dose rate for gynecology therapies; Implementacao de planejamento tridimensional em braquiterapia de alta taxa de dose para tratamentos ginecologicos

    Energy Technology Data Exchange (ETDEWEB)

    Sales, Camila Pessoa de

    2015-09-01

    This work aims to implement the three-dimensional (3D) planning for gynecological brachytherapy treatments. For this purpose, tests of acceptance and commissioning of brachytherapy equipment were performed to establish a quality and periodic assurance program. For this purpose, an important step was searching for a material to be used as a dummy source, since the applicators do not have any specific dummy. In addition, the validation of the use of applicators library was made for reconstruction in computed tomography (CT) and magnetic resonance imaging (MRI). In order to validate 3D planning, comparison of doses in dose assessment points used in bidimensional (2D) plans have been performed with volumetric doses to adjacent organs to the tumor. Finally, a protocol was established for 3D brachytherapy planning alternately using magnetic resonance image (MRI) and CT images, making evaluation of the dose in the tumor through the recording of MR and CT images. It was not possible to find a suitable material that could be used as dummy in MRI. However, the acquisition of the license's library for the applicators made possible the 3D planning based on MRI. No correlation was found between volumetric and specific doses analyzed, showing the importance of the implementation of 3D planning. The average ratio between D{sub 2cc} and ICRU{sub Bladder} dose was 1,74, 22% higher than the ratio found by others authors. For the rectum, D{sub 2cc} was less than dose point for 60% of fractions; the average difference was 12,5%. The average ratio between D{sub 2cc} and point dose rectum, 0,85, is equivalent to the value showed by Kim et al, 0,91. The D{sub 2cc} for sigmoid was 69% higher than point dose used, unless it was not possible compare this value, since the sigmoid point used in the 2D procedures is not used in others institutes. Relative dose in 2 cc of sigmoid was 57% of the prescription dose, the same value was found by in literature. This work enabled the

  4. Systems automated reporting of patient dose in digital radiology; Sistema automatizado para generacion de informes de dosis a paciente en radiologia digital

    Energy Technology Data Exchange (ETDEWEB)

    Collado Chamorro, P.; Sanz Freire, C. J.; Martinez Mirallas, O.; Tejada San Juan, S.; Lopez de Gammarra, M. S.

    2013-07-01

    It has developed a procedure automated reporting of doses to patients in Radiology. This procedure allows to save the time required of the data used to calculate the dose to patients by yields. Also saves the time spent in the transcription of these data for the realization of the necessary calculations. This system has been developed using open source software. The characteristics of the systems of digital radiography for the automation of procedures, in particular the registration of dose should benefit from patient. This procedure is validated and currently in use at our institution. (Author)

  5. Commercial sugar, an alternative dosemeter for the dose determination in radiological emergency conditions; Azucar comercial, un dosimetro alternativo para la determinacion de dosis en situaciones de emergencia radiologica

    Energy Technology Data Exchange (ETDEWEB)

    Urena N, F.; Galindo, S. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    1997-07-01

    It was carried out the dosimetric evaluation of commercial sugar, with the purpose to determine the feasibility to be able to use this type of substance as a dosimetric material in cases to present some radiological emergency cases. The studied parameters using the Electron Paramagnetic Resonance (EPR) technique were: pre-doses signal or depth signal, dose-response stability, reproducibility, reliability and signal clearing decreasing. (Author)

  6. Study of distribution dose for chest radiography using the computational model ALDERSON/EGSnrc; Estudo da distribuição de dose para radiografia de tórax utilizando o modelo computacional ALDERSON/EGSnrc

    Energy Technology Data Exchange (ETDEWEB)

    Muniz, B.C., E-mail: bianca.cm95@gmail.com [Instituto de Educação, Ciência e Tecnologia de Pernambuco (IFPE), Recife, PE (Brazil). Lab. de Dosimetria Numérica; Menezes, C.J.M. [Centro Regional de Ciências Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil). Lab. de Física Médica

    2017-07-01

    Numerical dosimetry uses Computational Exposure Models (MCE) to perform dose studies in situations of radiation exposure without the need for individuals to be exposed. MCEs are essentially composed of a simulator of the radioactive source, a Monte Carlo code, and a phantom of voxels representing the human anatomy. The objective of this work was to perform a study of the dose distribution in the thoracic region in radiographic exams using the MCE ALDERSON / EGSnrc. For that, virtual simulations were performed using Monte Carlo Method techniques to calculate the dose in the simulator of voxels representative of the thoracic region. The results show that most beam energy was deposited in the skeleton for all simulated radiological techniques, while smaller fractions were deposited in the lungs and soft tissue. For example, at 90 kV voltage, 14% of the energy was deposited in the bone medium, while lungs and soft tissue receive only 5 and 3%, respectively. It is concluded that the ALDERSON / EGSnrc MCE can be used for studies of the dose distribution on chest radiographs used in radiodiagnosis practice, thus optimizing dose absorbed in the patient in clinical exams.

  7. Quantification of micronuclei in blood lymphocytes of patients exposed to gamma radiation for dose absorbed assessment; Quantificacao de micronucleos em linfocitos de pacientes expostas a radiacao gama para a avaliacao da dose absorvida

    Energy Technology Data Exchange (ETDEWEB)

    Barbosa, Isvania Maria Serafim da Silva

    2003-02-15

    Dose assessment in an important step to evaluate biological effects as a result of individual exposure to ionizing radiation. The use of cytogenetic dosimetry based on the quantification of micronuclei in lymphocytes is very important to complement physical dosimetry, since the measurement of absorbed dose cannot be always performed. In this research, the quantification of micronuclei was carried out in order to evaluate absorbed dose as a result of radiotherapy with {sup 60}Co, using peripheral blood samples from 5 patients with cervical uterine cancer. For this purpose, an aliquot of whole blood from the individual patients was added in culture medium RPMI 1640 supplemented with fetal calf serum and phytohaemagglutinin. The culture was incubated for 44 hours. Henceforth, cytochalasin B was added to block the dividing lymphocytes in cytokinesis. The culture was returned to the incubator for further of 28 hours. Thus, cells were harvested, processed and analyzed. Values obtained considering micronuclei frequency after pelvis irradiation with absorption of 0,08 Gy and 1,8 Gy were, respectively, 0,0021 and 0,052. These results are in agreement with some recent researches that provided some standard values related to micronuclei frequency induced by gamma radiation exposure in different exposed areas for the human body. The results presented in this report emphasizes biological dosimetry as an important tool for dose assessment of either total or partial-body exposure to ionizing radiation, mainly in retrospective dose investigation. (author)

  8. Desarrollo de un software para el cálculo de la pérdida de potencia de un buque en función del aumento de la corrosión en su casco

    OpenAIRE

    Castells Mur, Marçal

    2016-01-01

    Uno de los problemas más importantes que se presenta en el proyecto de un buque es la determinación de su potencia para que el buque navegue a una determinada velocidad. Existen estudios para predeterminar la resistencia total en aguas tranquilas. Mientras que en mar abierto y al cabo de un cierto tiempo ésta resistencia es mayor. En este proyecto se va a desarrollar un software para calcular el incremento de resistencia del buque en función de la rugosidad adquirida a lo largo del tiempo...

  9. Medición y análisis de un modelo para la determinación del costo de capital de las pymes del subsector de confección en Bogotá

    OpenAIRE

    Cruz Castro, Carlos Hernán

    2012-01-01

    En síntesis, para los encargados de la gestión financiera en empresas del sector de la confección en Bogotá, existe un problema que tiene que ver con el desconocimiento de un modelo que les permita calcular el costo del capital que requieren para su financiamiento y que se adecue a las condiciones del entorno en que operan. Para aportar a la solución de dicho problema, el presente trabajo se propone realizar un repaso de los diferentes modelos teóricos disponibles en la literatura financie...

  10. Applicability of a prototype for determination of absorbed dose using brachytherapy equipment with Ir-192 sources; Aplicabilidade de um prototipo para determinacao da dose absorvida utilizando equipamentos de braquiterapia com fontes de IR-192

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Vivianne Lucia Bormann; Almeida, Mayara Gabriella Oliveira de; Vieira, Rafaela Etelvina de Amorim; Silva, Waldecy Ananias da; Nascimento, Rizia Keila, E-mail: vlsouza@cnen.gov.br, E-mail: mayaradqf@hotmail.com, E-mail: rodriguesss@hootmail.com, E-mail: waldecy@cnen.gov.br, E-mail: riziakeila@hotmail.com [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil)

    2014-07-01

    This work aims at the development and improvement of a device to perform the absolute dosimetry sources of Ir-192 using the Fricke solution contained in a flask. The Fricke solution used was prepared using amounts of ferrous ammonium sulfate, sodium chloride and sulfuric acid, diluted with water tri distilled pre-established in the literature. The spectrophotometer used was a UV-VIS spectrophotometer (Beckman DU-640 Counter) for measuring the optical density at wavelength 304 nm. The calculation for determining the radial dose takes into account the radial distance and the angle formed with the transverse axis of the source. As the results obtained can be seen that the states of Pernambuco, Ceara, Paraiba e Piaui are in accordance with the recommendations of international standards of the International Atomic Energy Agency (IAEA), which considers not acceptable a difference greater than 5% of prescribed dose and measured dose.

  11. Erosividade da chuva para o bioma Pantanal

    Directory of Open Access Journals (Sweden)

    Daniel Okamoto Machado

    2014-06-01

    Full Text Available A escassez de dados pluviográficos na região do Pantanal fez com que muitos autores utilizassem equações de regressão obtidas em outras regiões do Brasil para calcular o Fator R da Equação Universal de Perda de Solo (USLE. O presente estudo define equações para a previsão da erosividade em região do bioma Pantanal, correlacionando a erosividade das chuvas calculada pelo índice EI30 e o coeficiente de chuva (Rc. A equação desenvolvida, do tipo potencial, apresenta consistência e correlação significativa com os dados observados, obtendo valor de coeficiente de determinação de 97%. Portanto, a equação de erosividade proposta pode ser utilizada para estimativa do fator R da USLE a partir dos dados mensais e anuais de precipitação da região e de outras regiões com características climáticas semelhantes.

  12. Quantification of tomography images for dose calculation for diagnosis and therapy in nuclear medicine; Quantificacao de imagens tomograficas para calculo de dose em diagnose e terapia em medicina nuclear

    Energy Technology Data Exchange (ETDEWEB)

    Massicano, Felipe

    2010-07-01

    The nuclear medicine area has an increasing slope in the therapy of diseases, particularly in the treatment of radiosensitive tumors. Due to the high dose levels in radionuclide therapy, it is very important the accurate quantify of the dose distribution to avoid deleterious effects on healthy tissues. In Brazil, the internal dosimetry system used is the MIRD (Medical Internal Radiation Dose) based on a reference model that does not have adequate patient data to obtain a dose accurate assessment in therapy. However, in recent years, internal radionuclide dosimetry evaluates the spatial dose distribution base ad on information obtained from CT and SPECT or PET images together with the using of Monte Carlo codes. Those systems are called patient-specific dosimetry systems. In the Nuclear Engineering Center at IPEN, this methodology is in development. When the CT images are inserted into the Monte Carlo code MCNP5 through of use of a interface software called SCMS the dosimetry can be accomplished using patient-specific data, resulting in a more accurate energy deposition in organs of interest. This work aim to contribute with the development of part of that patient-specific dosimetry for therapy. To achieve this goal we have proposed three specific objectives: (1) Development of a software to convert images from Computed Tomography (CT) in the tissue parameters ({rho}, {omega}({iota})); (2) Development of a software to perform attenuation correction in nuclear medicine tomographic images (SPECT or PET) and to provide the map of relative activity and (3) Provide data to the SCMS code by these two software. The software developed for the rst specific objective was the Image Converter Computed Tomography (ICCT), which obtained a good accuracy to determine the density and the tissue composition; the elements that had high variation were carbon and oxygen. Fortunately, this variation for the energy range used in radionuclide therapy is not detrimental to the dose

  13. Potential radiation doses likely to be received by the radiologists and para medical staff in an hospital in Pakistan. (G. M. counter, survey meter measurements )

    International Nuclear Information System (INIS)

    Ali, A.; Zeb, J.; Iqbal, S.; Orfi, S.D.

    1999-01-01

    Potential radiation doses likely to received by the radiologists and paramedical staff in a typical hospital in Pakistan have been measured using a very sensitive radiation survey meter (FAG FH40F2) employing in Geiger Muller counter (FHZ 120] as a role which is extendable up to 4 meters in length. The measurements have been compared with internationally accepted Maximum Permissible Radiation Dos Level (MPDL). Radiation dose rates measured on the hands of two radiologist during fluoroscopy examination of the patient were of the order of 1 m Sv.h/sup -1/ and 540 u Sv. h/sup -1/ which were 400% to 21% higher than the MPDL (250 u Sv. h/sup -1/). Radiation dose rates measured on the chest of the nurses were 300 and 50 u Sv. h/sup -1/, which were 3000% to 500% higher than those of MPDL(10 u Sv. h/sup -1/). Such high dose rates present a serious situation from radiation damage point of view and deserve attention of the hospital management and of national regulatory authority so as to minimize the potential radiation doses to the radiologists and paramedical staff. As Low As Reasonably Achievable (ALARA) concept should be implemented in the health sector. (author)

  14. Promoción de la Salud Sexual: Aportes para la investigación y la acción

    OpenAIRE

    Cáceres, Carlos F.; Salazar, Ximena; Girón, Maziel; Olivos, Fernando; Pérez Luna, Griselda; Sandoval, Clara; Segura, Eddy; Zambrano, Débora

    2009-01-01

    El origen de esta publicación fue documentar el esfuerzo desarrollado por el equipo de la Unidad de Salud, Sexualidad y Desarrollo Humano de la Universidad Peruana Cayetano Heredia, dirigido por el Dr. Carlos F. Cáceres, para evaluar cuán factible resultaba el calcular los indicadores de salud sexual recomendados en el Marco de Implementación de la Estrategia. La primera parte de este libro se centra en los desafíos metodológicos que enfrentaron los investigadores para medir estos indicadores...

  15. Ionizing radiation dose control for workers in a nuclear plant working with unsealed sources; Controle da dose de radiacao ionizante para trabalhadores em uma instalacao radiativa com fontes nao seladas

    Energy Technology Data Exchange (ETDEWEB)

    Gerulis, Eduardo

    2006-07-01

    With the liberation of the use of the nuclear energy for peaceful applications, International Commission Radiological Protection, ICRP, founded in 1928, created a system of protection of the undesirable doses of ionizing radiation in 1958. This has been received by workers, members of the public and environment and hence it became possible for the introduction of these applications. This protection system is adopted by the International Agency of Energy Atomic, IAEA, that publishes recommendations in safety series, 88 and by the Comissao Nacional de Energia Nuclear, CNEN, which publishes these regulations. The international recommendations and national regulations were adapted and they need to be applied in this way. The present paper uses recommendations of the publication 75 from ICRP, of the publication 115 from 88 and regulations of the regulation NN 3.01 from CNEN to present, through radiological protection measures, the ionizing radiation dose control for workers in a nuclear plant that works in the research, production, division and packing of unsealed sources to be used in clinical applications. In that way it is possible to prevent appropriately the undesirable doses and to confirm the received doses. (author)

  16. Determination of gamma radiation dose for destruction of Salmonella spp. in chicken flesh.; Determinacao da dose de radiacao gama para a destruicao de Salmonella spp. em carne de frango

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Andreia Ferreira dos

    1997-07-01

    The aim of this study was to determinate: 1) the radio sensibility of Salmonella typhimurium ATCC 14028 in soy trypticase broth; 2) the radio sensibility of Salmonella typhimurium ATCC 14028 in chicken thigh and; 3) to recommend a radiation dose which can be non hazardous for human consumption

  17. MYDOZE: Application Web for management and optimisation of doses to patients in tests radiodiagnostics; MYDOZE: Aplicacion Web para gestion y optimizacion de dosis a pacientes en pruebas radiodiagnosticas

    Energy Technology Data Exchange (ETDEWEB)

    Peinado Zamora, A. B.; Laguna Lobato, M. A.; Gil Agudo, A.; Zapata Jimenez, J. C.

    2013-07-01

    The service of Radiofisica y Proteccion Radiologica del Hospital general Universitario de Ciudad Real, carried out a study whose objective is to optimize the dose to patients undergoing diagnostic scans with ionizing radiation. To address this task, is required a software tool that facilitates on the one hand the acquisition of dosimetric data acquired digital equipment and the other interface of exploitation of this data for statistics and analysis of these. the computer tool to develop should allow storing parameters with information demographic and dose of the patient in medical scans thanks to called DICOM medical image standard. (Author)

  18. Evaluation of the Analytical Anisotropic Algorithm (AAA) in dose calculation for fields with non-uniform fluences considering heterogeneity correction; Avaliacao do Algoritmo Analitico Anisotropico (AAA) no calculo de dose para campos com fluencia nao uniforme considerando correcao de heterogeneidade

    Energy Technology Data Exchange (ETDEWEB)

    Bornatto, P.; Funchal, M.; Bruning, F.; Toledo, H.; Lyra, J.; Fernandes, T.; Toledo, F.; Marciao, C., E-mail: pricila_bornatto@yahoo.com.br [Hospital Erasto Gaertner (LPCC), Curitiba, PR (Brazil). Departamento de Radioterapia

    2014-08-15

    The purpose of this study is to evaluate the calculation of dose distribution AAA (Varian Medical Systems) for fields with non-uniform fluences considering heterogeneity correction. Five different phantoms were used with different density materials. These phantoms were scanned in the CT BrightSpeed (©GE Healthcare) upon the array of detectors MAPCHECK2 TM (Sun Nuclear Corporation) and irradiated in a linear accelerator 600 CD (Varian Medical Systems) 6MV and rate dose 400MU/min with isocentric setup. The fluences used were exported from IMRT plans, calculated by ECLIPSE™ planning system (Varian Medical Systems), and a 10x10 cm{sup 2} field to assess the heterogeneity correction for uniform fluence. The measured dose distribution was compared to the calculated by Gamma analysis with approval criteria of 3% / 3 mm and 10% threshold. The evaluation was performed using the software SNCPatient (Sun Nuclear Corporation) and considering absolute dose normalized at maximum. The phantoms best performers were those with low density materials, with an average of 99.2% approval. Already phantoms with plates of higher density material presented various fluences below 95% of the points approved. The average value reached 94.3%. It was observed a dependency between fluency and approved percentage points, whereas for the same fluency, 100% of the points have been approved in all phantoms. The approval criteria for IMRT plans recommended in most centers is 3% / 3mm with at least 95% of points approved, it can be concluded that, under these conditions, the IMRT plans with heterogeneity correction can be performed , however the quality control must be careful because the difficulty of the system to accurately predict the dose distribution in certain situations. (author)

  19. Baixas doses de bupivacaína a 0,5% isobárica para raquianestesia unilateral Bajas dosis de bupivacaína a 0,5% isobárica para raquianestesia unilateral Low isobaric 0.5% bupivacaine doses for unilateral spinal anesthesia

    Directory of Open Access Journals (Sweden)

    Luiz Eduardo Imbelloni

    2004-06-01

    Full Text Available JUSTIFICATIVA E OBJETIVOS: A raquianestesia unilateral pode apresentar diversas vantagens, principalmente no paciente ambulatorial. Baixas doses de anestésicos locais, lenta velocidade de injeção subaracnóidea e posição de decúbito lateral são relacionados com a facilidade de produzir distribuição unilateral na raquianestesia. Neste estudo, foi verificada a possibilidade de se obter raquianestesia unilateral com bupivacaína a 0,5% isobárica. MÉTODO: A raquianestesia com 1 ml de bupivacaína isobárica a 0,5% (5 mg foi realizada através de agulha 27G Quincke em 25 pacientes, estado físico ASA I e II submetidos à cirurgias ortopédicas. A punção subaracnóidea foi realizada por via lateral com o paciente em decúbito lateral, com o membro a ser operado voltado para cima, e 1 ml de bupivacaína isobárica foi injetado na velocidade de 1 ml.30s-1. Bloqueios sensitivo e motor (picada de agulha e escala de 0 a 3 foram comparados entre os lados a ser operado e o contralateral. RESULTADOS: Os bloqueios motor e sensitivo entre o lado operado e o contralateral foram significativamente diferentes em todos os tempos avaliados. No membro operado todos os pacientes apresentaram anestesia cirúrgica. No membro contralateral, aos 20 minutos, 9 pacientes apresentaram bloqueio sensitivo; aos 40 minutos 18 pacientes e aos 60 minutos 17 pacientes. Portanto, o bloqueio sensitivo unilateral ocorreu em 7 pacientes (28% e em ambos os membros em 18 pacientes (72%. Raquianestesia unilateral foi obtida em 28% dos pacientes. Estabilidade hemodinâmica foi observada em todos os pacientes. Nenhum paciente desenvolveu cefaléia pós-punção dura-máter. CONCLUSÕES: A bupivacaína isobárica (5 mg proporciona predominante bloqueio unilateral após 20 minutos na posição lateral. A solução isobárica de bupivacaína se mobiliza dentro do LCR após 20 minutos, resultando num bloqueio unilateral em apenas 28% dos pacientes. A principal vantagem da

  20. Utilization of ALANPOL dosemeter composed by alanine and polyethylene for determination of doses in industrial effluents; Utilizacao do dosimetro ALANPOL composto por alanina e polietileno para determinacao de doses em efluentes industriais

    Energy Technology Data Exchange (ETDEWEB)

    Rela, Carolina S.; Sampa, Maria Helena de O.; Napolitano, Celia M. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)]. E-mail: csrela@ipen.br; Pontuschka, Walter M. [Sao Paulo Univ., SP (Brazil). Inst. de Fisica

    2005-07-01

    A study of traceability and accuracy was performed with the dosimetry system ALANPOL developed by IVHTJ/ Poland that uses alanine as a dosimeter and EPR as the read out system. The dosimeter ALANPOL is a polymer compound that aggregates alanine. The dosimeter has the outside diameter 3 mm, and the length of 25,4 mm (1 inch). In order to use this dosimeter for monitoring the existing real time calorimetry dosimeter system set up in a electron beam waste treatment plant. Electron beam and gamma irradiation experiments with ALANPOL was carried out under demineralized water and industrial effluent. The result show that in the dose range of 1-40 kGy the ALANPOL dosimeter system is suitable underwater monitoring for absorbed dose and can be applied for the evaluation of the on line calorimetry dosimeter system. (author)

  1. Evaluation of dose calculation algorithms using the treatment planning system XiO with tissue heterogeneity correction turned on; Validacao dos algoritmos de calculo de dose do sistema de planejamento XiO considerando as correcoes para heterogeneidade dos tecidos

    Energy Technology Data Exchange (ETDEWEB)

    Fairbanks, L.R.; Barbi, G.L.; Silva, W.T. da; Reis, E.G.F. dos; Borges, L.F.; Bertucci, E.C.; Maciel, M.F.; Amaral, L.L. do, E-mail: lefairbanks@yahoo.com.b [Universidade de Sao Paulo (USP), Ribeirao Preto, SP (Brazil). Hospital das Clinicas. Servico de Radioterapia

    2010-07-01

    Since the cross-section for various radiation interactions is dependent upon tissue material, the presence of heterogeneities affects the final dose delivered. This paper aims to analyze how different treatment planning algorithms (Fast Fourier Transform, Convolution, Superposition, Fast Superposition and Clarkson) work when heterogeneity corrections are used. To that end, a farmer-type ionization chamber was positioned reproducibly (during the time of CT as well as irradiation) inside several phantoms made of aluminum, bone, cork and solid water slabs. The percent difference between the dose measured and calculated by the various algorithms was less than 5%; This is in accordance with the recommendation of several references.The convolution method shows better results for high density materials (difference {approx}1 %), whereas the Superposition algorithm is more accurate for low densities (around 1,1%).

  2. Evaluation of dose calculation algorithms using the treatment planning system Xi O with tissue heterogeneity correction turned on; Validacao dos algoritmos de calculo de dose do sistema de planejamento Xi O considerando as correcoes para heterogeneidade dos tecidos

    Energy Technology Data Exchange (ETDEWEB)

    Fairbanks, Leandro R.; Barbi, Gustavo L.; Silva, Wiliam T.; Reis, Eduardo G.F.; Borges, Leandro F.; Bertucci, Edenyse C.; Maciel, Marina F.; Amaral, Leonardo L., E-mail: lefairbanks@yahoo.com.b [Universidade de Sao Paulo (HCRP/USP), Ribeirao Preto, SP (Brazil). Hospital das Clinicas. Servico de Radioterapia

    2011-07-01

    Since the cross-section for various radiation interactions is dependent upon tissue material, the presence of heterogeneities affects the final dose delivered. This paper aims to analyze how different treatment planning algorithms (Fast Fourier Transform, Convolution, Superposition, Fast Superposition and Clarkson) work when heterogeneity corrections are used. To that end, a farmer-type ionization chamber was positioned reproducibly (during the time of CT as well as irradiation) inside several phantoms made of aluminum, bone, cork and solid water slabs. The percent difference between the dose measured and calculated by the various algorithms was less than 5%.The convolution method shows better results for high density materials (difference {approx}1 %), whereas the Superposition algorithm is more accurate for low densities (around 1,1%). (author)

  3. Safety analysis for the Abadia de Goias repository: alternative evaluation of the ingestion dose rate critical distance; Analise de seguranca para o repositorio de Abadia de Goias: avaliacao alternativa da distancia critica de taxa de dose de ingestao

    Energy Technology Data Exchange (ETDEWEB)

    Martin Alves, A.S. de; Passos, E.M. dos [NUCLEN, Rio de Janeiro, RJ (Brazil)

    1995-12-31

    An alternative calculation of the ingestion dose rate critical distance due to a hypothetical release of Cs-137 from the structure of the Repository of Abadia de Goias is presented. The release pathway considers the repository - groundwater region - well - and food chain. The main adopted modification comparing to the previous work is the inclusion of the convective and molecular diffusion terms in the radionuclide transport equation in addition to the radioactive decay term. (author). 6 refs, 1 tab.

  4. Dose evaluation and establishment of reference levels in activity for nuclear medicine; Avaliação de dose e estabelecimento de níveis de referência em atividade para a medicina nuclear

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro, Julio Cesar de Souza

    2017-07-01

    The International Commission on Radiation Protection (ICRP) has emphasized the importance of accurately determining the mean dose levels, or administered activity, received by the patients for each medical procedure that uses ionizing radiation. However, the number of bibliographic references addressing the need to know and optimize these levels is insufficient, or rather limited, which may lead to non-standardizes techniques, a lack of exposures control, and also the increase of associated radiological risks of these procedures. In this context, a software in Visual Basic® of Microsoft© language was developed whose function is to elaborate a method of obtaining the Reference Levels in Activity (RLA) for nuclear medicine patients by determining the third quartile of the examinations carried out. The program also allows obtaining absorbed dose values in critical organs based on patient specificities as age, sex and Body Mass Index (BMI) in order to evaluate the risk involved in each procedure. The main nuclear medicine diagnostic procedures were evaluated through the database of two public hospitals and a private clinic, obtaining the NRAs of each facility, where the software was validated by comparison with the traditionally accepted calculation methods. Due to the results obtained in each installation, in addition to NRA determination, gaps in treatment capacities and unjustified dose variations for the same procedure were identified, indicating the need for optimization. Thus, the developed program is able to provide the estimated values of effective and absorbed doses involved in each procedure, for each patient, providing reference values for nuclear medicine field, not available in the national scenario so far. (author)

  5. Proposal of a high dose rate brachytherapy model for in vitro radiobiology studies; Proposta de um modelo de braquiterapia de alta taxa de dose para estudos de radiobiologia in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Geraldo, Jony M.; Nogueira, Luciana B.; Andrade, Lidia M. [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil); Trindade, Cassia [Hospital Luxemburgo, Belo Horizonte, MG (Brazil); Furtado, Clascidia A.; Ladeira, Luiz Orlando, E-mail: jony.marques@mariopenna.org.br [Centro de Desenvolvimento da Tecnologia Nuclear (CTDN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2016-07-01

    The aim of this research was to develop an easy and reproducible approach for experimental HDR brachytherapy allowing in vitro irradiation studies based on clinical parameters. An acrylic platform was designed to attach T25 tissue culture flasks and multi-well tissue culture plates as well as kept the catheters in a fixed position during irradiation. CT images were taken and the irradiation was planned for 550cGy dose applied on adherent tumor cells. Dosimetric measurements were done and all relevant uncertainties were taken into account in order to figure out the correct dose range received by the cells. Tumor cells were irradiated two times over an interval of 24h between irradiations. Proof of concepts of this approach was carried out by biological effects analysis using a radioresistant human epidermoid carcinoma A431 cell line. Cellular proliferation and cell cycle phase were assessed by Trypan blue exclusion assay and DNA content analysis by flow cytometry, respectively. This approach allowed uniform dose distribution around the arrangement in all types of tissue culture plastics evaluated. Corrections due to uncertainties were managed. Regarding in vitro assays there was a significant (p<0.05) decreasing of cellular proliferation rate in irradiated cells. Moreover, increased percentage of cells arrested in G2/M phase (32.3 ± 1.5%) were observed for treated group compared with untreated cells. (author)

  6. Proposal of a high dose rate brachytherapy model for radiobiology studies in vitro; Proposta de um modelo de braquiterapia de alta taxa de dose para estudos de radiobiologia in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Geraldo, Jony M.; Andrade, Lidia M., E-mail: jony.marques@mariopenna.org.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte (Brazil). Departamento de Fisica; Trindade, Cassia [Hospital Luxemburgo, Belo Horizonte, MG (Brazil); Nogueira, Luciana B. [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte (Brazil). Faculdade de Medicina; Furtado, Clascidia A.; Ladeira, Luiz Orlando [Centro de Desenvolvimento da Tecnologia Nuclear (CTDN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2016-07-01

    The aim of this research was to develop an easy and reproducible approach for experimental HDR brachytherapy allowing in vitro irradiation studies based on clinical parameters. An acrylic platform was designed to attach T25 tissue culture flasks and multi-well tissue culture plates as well as kept the catheters in a fixed position during irradiation. CT images were taken and the irradiation was planned for 550cGy dose applied on adherent tumor cells. Dosimetric measurements were done and all relevant uncertainties were taken into account in order to figure out the correct dose range received by the cells. Tumor cells were irradiated two times over an interval of 24h between irradiations. Proof of concepts of this approach was carried out by biological effects analysis using a radioresistant human epidermoid carcinoma A431 cell line. Cellular proliferation and cell cycle phase were assessed by Trypan blue exclusion assay and DNA content analysis by flow cytometry, respectively. This approach allowed uniform dose distribution around the arrangement in all types of tissue culture plastics evaluated. Corrections due to uncertainties were managed. Regarding in vitro assays there was a significant (p<0.05) decreasing of cellular proliferation rate in irradiated cells. Moreover, increased percentage of cells arrested in G2/M phase (32.3 ± 1.5%) were observed for treated group compared with untreated cells. (author)

  7. A methodology to establish the appearance of cancer cases due to radiation dose in compressed breast; Uma metodologia para comprovar o aparecimento de casos de cancer devido a dose de radiacao na mama comprimida

    Energy Technology Data Exchange (ETDEWEB)

    Feital, Joao Carlos Da Silva; Delgado, Jose Ubiratan; Peixoto, Jose Guilherme P.; Fonseca, Hugo Geraldo Da, E-mail: jfeital@ird.gov.br, E-mail: delgado@ird.gov.br, E-mail: guilherm@ird.gov.br, E-mail: hfonseca@ird.gov.br [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2013-10-01

    It is known that more than 20% of the world's population will contract some type of cancer. In Brazil, with the exception of skin cancer (non melanoma) the breast cancer ranks first among the higher frequency of tumours among women and in general, although the methods of detection are advancing in the year 2010 took place about 13 thousand deaths in about 50,000 cases, probably due to late detection of these neoplasm. New cases of breast cancer in a given population can be proven from absorbed dose quantity, calculated for the compressed breast, due to the risk by means of exposure to x rays in this radiodiagnostic practices. Methodology: Exposures were held in an ionization chamber and the other quantities required were obtained to the screen-film equipment of mammography. Results: Also experimental results were of compressed breast an equivalent dose of ( 1.82 mSv {+-} 0.2%) or (3.64 mSv {+-} 0.2%) for both projections, i.e. medium lateral oblique and cranio caudal. The experimental value obtained here is consistent with the calculated results and published in the literature for analog and CR equipment. Conclusion: From the result of dose equivalent in the breast, one can say that there will be effectively attesting as to the appearance of new cases of cancer if approximately 80 million women are exposed to radiation emitted by mammographers. (author)

  8. Monte Carlo method for dose calculation due to oral X-rays; Coeficientes de conversao para calculo de doses devidos a radiografias odontologicas utilizando o metodo de Monte Carlo

    Energy Technology Data Exchange (ETDEWEB)

    Loureiro, Eduardo Cesar de Miranda

    1998-06-01

    The increasing utilization of oral X-rays, especially in youngsters and children, calls for the assessment of equivalent doses in their organs and tissues. With this purpose, a Monte Carlo code was adapted to simulate an X-ray source irradiating phantoms of the MIRD-5 type with different ages (10, 15 and 40 years old) to calculate the conversion coefficients which transform the exposure at skin to equivalent doses at several organs and tissues of interest. In order to check the computer program, simulations were performed for adult patients using the original code (ADAM.FOR developed at the GSF-Germany) and the adapted program (MCDRO.PAS). Good agreement between results obtained with both codes was observed. Irradiations of the incisive, canine and molar teeth were simulated. The conversion factors were calculated for the following organs and tissues: thyroid, active bone narrow (head and whole body), bone (facial skeleton, cranium and whole body), skin (head and whole body) and crystalline. Based on the obtained results, it follows that the younger the patient and the larger the field area, the higher the dose in assessed organs and tissues. The variation of the source-skin distance does not change the conversion coefficients. On the other hand, the increase in the voltage applied to the X-ray tube causes an increase in the calculated conversion coefficients. (author)

  9. Diseño y cálculo de un reductor de velocidad para un polipasto de uso industrial de engranajes cilíndricos de dientes helicoidales, con hipótesis de cálculo para los dos sentidos de giro de motor

    OpenAIRE

    SORO SALA, SANTIAGO

    2016-01-01

    [ES] El objetivo de este trabajo final de grado es el de diseñar y calcular un reductor de velocidades, de uso industrial, para un polipasto de cadena. El reductor de velocidades será de dos etapas, de engranajes cilíndricos de dientes helicoidales. Se realizan los cálculos para las hipótesis de giro horario y antihorario, Esto se debe a que este tipo de engranajes, transmiten esfuerzos axiales, de dirección variable según su sentido de giro. En el proceso de cálculo del red...

  10. Determination of the dose around an ovoid for treatments in intracavitary brachytherapy Hdr; Determinacion de la dosis alrededor de un ovoide para tratamientos en braquiterapia intracavitaria HDR

    Energy Technology Data Exchange (ETDEWEB)

    Rivera M, T. [IPN, Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada, Legaria No. 694, Col. Irrigacion, 11500 Mexico D. F. (Mexico); Velasco V, R. A. E. [Hospital Central Militar, Periferico y Ejercito Nacional s/n, Lomas de Sotelo, 11200 Mexico D. F. (Mexico); Serrano F, A. K. [Hospital Juarez de Mexico, Av. Instituto Politecnico Nacional No. 5190, Col. Magdalena de las Salinas, 03220 Mexico D. F. (Mexico); Azorin N, J., E-mail: trivera@ipn.m [Universidad Autonoma Metropolitana, Unidad Iztapalapa, Av. San Rafael Atlixco No. 186, Col. Vicentina, 09340 Mexico D. F. (Mexico)

    2010-09-15

    On this work the results of the dosimetric measurements are presented around an ovoid of 2 cm diameter. The measurements were carried out using a water mannequin, an ovoid, a radiation gamma source of {sup 192}Ir and thermoluminescent dosemeters. The dosimetry was realized in the direction of the rectum and bladder. To know the effect of the shielding of the devices type Manchester in the dose, the thermoluminescent dosemeters were irradiated to a radiation gamma source of {sup 192}Ir contained in the Gamma med Plus equipment. The planning was realized normalizing the calculation to 2.5 cm from the applicator center on the transverse plane (2.5, 0, 0). The results show that the dose distribution for an ovoid without shielding is more uniform in the transversal plane to the source axis. The results were compared with the calculated results by means of the planning system BrachyVision. While the absorbed dose distribution around an ovoid with shielding is completely anisotropic. This anisotropic is due to the shielding. (Author)

  11. Baixa dose de bupivacaína isobárica, hiperbárica ou hipobárica para raquianestesia unilateral Baja dosis de bupivacaína isobara, hiperbara o hipobara para anestesia raquidea unilateral Low dose isobaric, hyperbaric, or hypobaric bupivacaine for unilateral spinal anesthesia

    Directory of Open Access Journals (Sweden)

    Luiz Eduardo Imbelloni

    2007-06-01

    Full Text Available JUSTIFICATIVA E OBJETIVOS: A raquianestesia unilateral pode apresentar vantagens principalmente em pacientes em regime ambulatorial. Baixa dose da solução anestésica, velocidade lenta da injeção espinal e a posição lateral facilitam a obtenção da distribuição unilateral na raquianestesia. Foram comparadas soluções isobárica, hiperbárica e hipobárica de bupivacaína com objetivos de se obter raquianestesia unilateral em pacientes submetidos a intervenções cirúrgicas ortopédicas em regime ambulatorial. MÉTODO: Cento e cinqüenta pacientes foram aleatoriamente separados em três grupos para receberem 5 mg de bupivacaína a 0,5% isobárica (Grupo Iso, ou 5 mg de bupivacaína a 0,5% hiperbárica (Grupo Hiper, ou 5 mg de bupivacaína a 0,15% hipobárica (Grupo Hipo. As soluções foram administradas no interespaço L3-L4 com o paciente na posição lateral e permanecendo nesta posição por 20 minutos. A anestesia sensitiva foi avaliada pelo teste da picada da agulha. O bloqueio motor avaliado pela escala modificada de Bromage. Ambos os bloqueios foram comparados com o lado não operado e entre si. RESULTADOS: Existiu diferença significativa entre o lado operado e não-operado em todos os três grupos aos 20 minutos, mas maior freqüência de raquianestesia unilateral foi obtida com as soluções hiperbárica e hipobárica de bupivacaína. Bloqueio sensitivo e motor foram observados em 14 pacientes do Grupo Iso, 38 pacientes no Grupo Hiper e 40 pacientes no Grupo Hipo. Não ocorreram alterações hemodinâmicas em nenhum paciente. Não foram observados cefaléia pós-punção nem sintomas neurológicos temporários. CONCLUSÕES: A raquianestesia com soluções hipobárica e hiperbárica proporcionou maior freqüência de unilateralidade. Após 20 minutos a solução isobárica de bupivacaína mobilizou-se no líquido cefalorraquidano (LCR, resultando em apenas 28% de raquianestesia unilateral.JUSTIFICATIVA Y OBJETIVOS: La

  12. Preliminary analysis of doses to evaluate the image quality in radiographic examinations in veterinary radiology;Analise preliminar das doses para avaliacao da qualidade da imagem em exames radiograficos na radiologia veterinaria

    Energy Technology Data Exchange (ETDEWEB)

    Pinto, Ana Carolina B.C.F.; Dias, Mayara T.P.; Santos, Andrea C. [Universidade de Sao Paulo (USP), SP (Brazil). Faculdade de Medicina Veterinaria e Zootecnia; Melo, Camila S.; Furquim, Tania A.C. [Universidade de Sao Paulo (IEE/USP), SP (Brazil). Inst. de Eletrotecnica e Energia

    2009-07-01

    This work has as objective to promote the analysis of the radiological doses and quality of the image of the technical letter used for the accomplishment of thorax and coxal radiographic examination of animals of canine and feline species. The study was accomplished in the service of Diagnosis for Image in Veterinarian Hospital of Veterinary Medicine and Zootecnia College of University of Sao Paulo, in two conventional equipment. Initially, physical features of the animals and the technique used were collected for each one of the 188 radiographic examinations of thorax and 52 examinations of coxal. The animals were placed in different groups, according to their body weight. For each group, the averages for each feature were calculated: thickness of the radiographed region, tension, electric current, time of exhibition, current product electric-time, size of the used film, presence or absence of bucky and feature of focus (narrow or thick). On the basis of the averages of group M (of lesser weights that 5kg for cats and between 10,1kg and 20kg for dogs), was executed a physical analysis of the current technical letter, using the equipment: ionization chamber (to determinate the value of kerma in air), simulator objects (representative of the thickness of the animal) and three dispositive standards of test that evaluate space resolution, resolution in low contrast and contrast-detail. The obtained images were analyzed and compared for a physicist and a radiologist medical veterinary. The results had shown that the examinations supply dose considered high for techniques used mainly for coxal. The equipment A, although to supply higher doses, presents the better images for the majority of the projections. However, the study indicates that there are not exactly reference levels, but these examinations must pass for improvement of quality of image (author)

  13. Study of noise sources of image for optimization of radiation doses in skull computerized tomography; Estudo das fontes de ruido da imagem para fins de otimizacao das doses na tomografia computadorizada de cranio

    Energy Technology Data Exchange (ETDEWEB)

    Medeiros, R.B.; Garos, K.A.C. [UNIFESP - Universidade Federal de Sao Paulo, SP (Brazil)]. E-mail: rbitelli@cfrh.epm.br

    2001-07-01

    Our goal was to evaluate the exposure factors that can change the image noise of head CT in different slices thicknesses. We have evaluated the images noise at several mAs varying from 50 to 800 mAs for 100, 120 and 140 kVp as tension values. The images uniformity were determined for all technical exposure conditions. We did not observed any important noise reduction for values up 200 mAs which can justify the increase of radiation doses through the increase of mAs. (author)

  14. Control system for solar tracking based on artificial vision; Sistema de control para seguimiento solar basado en vision artificial

    Energy Technology Data Exchange (ETDEWEB)

    Pacheco Ramirez, Jesus Horacio; Anaya Perez, Maria Elena; Benitez Baltazar, Victor Hugo [Universidad de onora, Hermosillo, Sonora (Mexico)]. E-mail: jpacheco@industrial.uson.mx; meanaya@industrial.uson.mx; vbenitez@industrial.uson.mx

    2010-11-15

    This work shows how artificial vision feedback can be applied to control systems. The control is applied to a solar panel in order to track the sun position. The algorithms to calculate the position of the sun and the image processing are developed in LabView. The responses obtained from the control show that it is possible to use vision for a control scheme in closed loop. [Spanish] El presente trabajo muestra la manera en la cual un sistema de control puede ser retroalimentado mediante vision artificial. El control es aplicado en un panel solar para realizar el seguimiento del sol a lo largo del dia. Los algoritmos para calcular la posicion del sol y para el tratamiento de la imagen fueron desarrollados en LabView. Las respuestas obtenidas del control muestran que es posible utilizar vision para un esquema de control en lazo cerrado.

  15. New routes of preparation of polyaniline films and dosimetric characterization for high-doses gamma radiation; Novas rotas de preparacao de filmes de polianilina e caracterizacao dosimetrica para radiacao gama em altas doses

    Energy Technology Data Exchange (ETDEWEB)

    Pacheco, Ana Paula Lima

    2003-08-15

    This work presents a new conducting polymeric material based on polyaniline thin films that will be used in the confection of dosimetric devices. On preparation of the films a homogeneous and viscous solution of poly (acrylic acid) and MnO{sub 2} is deposited on PMMA surface, which after dried, is immersed in an acid aniline solution. The films formed present low resistivity (6.10{sup 2} {omega}m), good mechanical resistance and adherence on the electrodes. The films were characterized by infrared spectroscopy, conductivity measurements and manganese elemental analyses. The resistance variations show linear correlation (r{sup 2} = 0,9928) with gamma irradiation dose in the range of 1000 to 6000 Gy, with medium error less than 5% and sensitivity response. The dosimetric devices present as advantage real time measurements, low cost, use in calibration of industrial radioactive sources. Moreover, this composite could in future replace Fricke dosimeter and its applications. A calibration curve is showed for PANI dosimeter, here proposed, to use at high gamma doses. (author)

  16. Parameter calculation tool for the application of radiological dose projection codes; Herramienta de calculo de parametros para la aplicacion de codigos de proyeccion de dosis radiologicas

    Energy Technology Data Exchange (ETDEWEB)

    Galindo G, I. F.; Vergara del C, J. A.; Galvan A, S. J. [Instituto Nacional de Electricidad y Energias Limpias, Reforma 113, Col. Palmira, 62490 Cuernavaca, Morelos (Mexico); Tijerina S, F., E-mail: francisco.tijerina@cfe.gob.mx [CFE, Central Nucleoelectrica Laguna Verde, Carretera Federal Cardel-Nautla Km 42.5, 91476 Municipio Alto Lucero, Veracruz (Mexico)

    2016-09-15

    The use of specialized codes to estimate the radiation dose projection to an emergency postulated event at a nuclear power plant requires that certain plant data be available according to the event being simulated. The calculation of the possible radiological release is the critical activity to carry out the emergency actions. However, not all of the plant data required are obtained directly from the plant but need to be calculated. In this paper we present a computational tool that calculates the plant data required to use the radiological dose estimation codes. The tool provides the required information when there is a gas emergency venting event in the primary containment atmosphere, whether well or dry well and also calculates the time in which the spent fuel pool would be discovered in the event of a leak of water on some of the walls or floor of the pool. The tool developed has mathematical models for the processes involved such as: compressible flow in pipes considering area change and for constant area, taking into account the effects of friction and for the case of the spent fuel pool hydraulic models to calculate the time in which a container is emptied. The models implemented in the tool are validated with data from the literature for simulated cases. The results with the tool are very similar to those of reference. This tool will also be very supportive so that in postulated emergency cases can use the radiological dose estimation codes to adequately and efficiently determine the actions to be taken in a way that affects as little as possible. (Author)

  17. Determination of optimal doses of radiation for the plant breeding of pseudo cereals; Determinacion de dosis optimas de radiacion para el mejoramiento de seudocereales

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez J, J [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico); Gomez P, L [Universidad Nacional Agraria La Molina, Lima (Peru)

    2005-07-01

    With the purpose of promoting the use of the radiations for the plant breeding of pseudo cereals, it was determined a simple and economic method that allows the quick selection of radiation dose that induce in the vegetable organisms the changes wanted. For it it was work with quinua seeds (Chenopodium quinoa Willd.) an Andean pseudo cereal that, due to their nutritious and physiologic characteristics it is considered by the FAO like one of the foods of the future and for the NASA like an organism that is good to remove the carbon dioxide from the atmosphere and at the same time, to generate food, oxygen and water for the crew during the space missions of long duration and that it has already improved by means of the radiation application. The proposed method consists on the evaluation, of the embryonic structures (radicule, hypocotyl and cotyledons) in the irradiated seeds as well as of the development of root, primary shaft and true leaves in the plants. The changes in the growth, form, number and color of the structures as well as the time of appearance of each one, allow to predict the morphological changes and inclusive some physiologic ones that will have the mature organisms, so that in only three weeks it is possible to select the doses more appropriate. (Author)

  18. Development of a program for calculation of second dose and securities in brachytherapy high dose rate; Elaboracion de un programa para el segundo calculo de la dosis y seguridades en braquiterapia de alta tasa de dosis

    Energy Technology Data Exchange (ETDEWEB)

    Esteve Sanchez, S.; Martinez Albaladejo, M.; Garcia Fuentes, J. D.; Bejar Navarro, M. J.; Capuz Suarez, B.; Moris de Pablos, R.; Colmenares Fernandez, R.

    2015-07-01

    We assessed the reliability of the program with 80 patients in the usual points of prescription of each pathology. The average error of the calculation points is less than 0.3% in 95% of cases, finding the major differences in the axes of the applicators (maximum error -0.798%). The program has proved effective previously testing him with erroneous dosimetry. Thanks to the implementation of this program is achieved by the calculation of the dose and part of the process of quality assurance program in a few minutes, highlighting the case of HDR prostate due to having a limited time. Having separate data sheet allows each institution to its protocols modify parameters. (Author)

  19. Development of a computational code for the internal doses assessment of the main radionuclides of occupational exposure at IPEN; Desenvolvimento de um codigo computacional de apoio ao calculo de dose interna para radionuclideos de interesse do IPEN

    Energy Technology Data Exchange (ETDEWEB)

    Claro, Thiago Ribeiro

    2011-07-01

    The dose resulting from internal contamination can be estimated with the use of biokinetic models combined with experimental results obtained from bioanalysis and assessment of the time of incorporation. The biokinetics models are represented by a set of compartments expressing the transportation, retention and elimination of radionuclides from the body. The ICRP publications, number 66, 78 and 100, present compartmental models for the respiratory tract, gastrointestinal tract and for systemic distribution for an array of radionuclides of interest for the radiological protection. The objective of this work is to develop a computational code for the internal doses assessment of the main radionuclides of occupational exposure at IPEN. Consequently serving as a agile and efficient tool for the designing, visualization and resolution of compartmental models of any nature. The architecture of the system was conceived containing two independent software: CBT - responsible for the setup and manipulation of models and SSID - responsible for the mathematical solution of the models. Four different techniques are offered for the resolution of system of equations, including semi-analytical and numerical methods, allowing for comparison of precision and performance of both. The software was developed in C{ne} programming, using a Microsoft Access database and XML standards for file exchange with other applications. Compartmental models for uranium, thorium and iodine radionuclides were generated for the validation of the CBT software. The models were subsequently solved via SSID software and the results compared with the values published in the issue 78 of ICRP. In all cases the system replicated the values published by ICRP. (author)

  20. Biological assay of chromatin dispersal simplified for determining absorbed dose of ionizing radiation; Ensayo biologico simplificado de dispersion de cromatina para la determinacion de dosis de radiacion ionizante

    Energy Technology Data Exchange (ETDEWEB)

    Galaz, S.; Perez, G.; Stockert, J. C.; Blazquez-Castro, A.

    2011-07-01

    Currently, the production of nuclear halos chromatin dispersion methods is a good procedure for nuclear analysis by in situ hybridization (Wiegant et al., 1992, Gerdes et al. 1994), to detect apoptosis, DNA fragmentation and cell death rates in cell cultures (Fernandez et al., 2005, Enciso et al. 2006). It is customary to display the nuclear halos by fluorescence microscopy using propidium iodide, ethidium bromide or DAPI (Gerdes et al., 1994, Sestili et al. 2006). Using this technique based on a modified protocol of fast halo assay [FHA],(Sestili et al. 2006), has developed a simplified method to quantify the cytogenetic damage induced by ionizing radiation (dispersion test chromatin in agarose thin smear), which allows visualization of halos after staining for light microscopy or fluorescence and correlating the ratio: total area occuped by the halo nucleus / nucleus (halo-core index [IHN] ) with radiation dose.

  1. Software para el cálculo de parámetros en cribas vibratorias de separación bajo el criterio de la velocidad límite de las partículas

    OpenAIRE

    Arturo Martínez Rodríguez

    2009-01-01

    Se presenta el manual de usuario del software "CRIBAS" para el cálculo de los principales arámetros de las cribas vibratorias empleadas para la limpieza o clasificación de productos agrícolas. El software posibilita calcular los parámetros adecuados de las cribas vibratorias de manera tal que las partículas que deben pasar a través de los agujeros de la superficie de la criba, no sobrepasen, en su movimiento de avance a lo largo de la criba, la dimensión de dichos agujeros, lo cual se garan...

  2. Un método numérico-estadístico para determinar el volumen elemental representativo (VER) de la pasta de cemento en la medición de la difusividad

    OpenAIRE

    Zhang, M. Z.; Ye, G.; van Breugel, K.

    2010-01-01

    La difusividad del hormigón depende de su microestructura a numerosas escalas, desde nanómetros hasta milímetros, por lo que se precisa de técnicas multiescala para representar este parámetro. Junto con el principio de homogeneización, uno de los métodos multiescala más habituales es el volumen elemental representativo (VER). El objeto de este estudio era establecer un procedimiento que permitiera determinar el VER necesario para calcular la difusividad de la pasta de cemento, basándose en un...

  3. Development of a computational model for the calculation of neutron dose equivalent in laminated primary barriers of radiotherapy rooms; Desenvolvimento de um modelo computacional para calculo do equivalente de dose de neutrons em barreiras primarias laminadas de salas de radioterapia

    Energy Technology Data Exchange (ETDEWEB)

    Rezende, Gabriel Fonseca da Silva

    2015-06-01

    Many radiotherapy centers acquire 15 and 18 MV linear accelerators to perform more effective treatments for deep tumors. However, the acquisition of these equipment must be accompanied by an additional care in shielding planning of the rooms that will house them. In cases where space is restricted, it is common to find primary barriers made of concrete and metal. The drawback of this type of barrier is the photoneutron emission when high energy photons (e.g. 15 and 18 MV spectra) interact with the metallic material of the barrier. The emission of these particles constitutes a problem of radiation protection inside and outside of radiotherapy rooms, which should be properly assessed. A recent work has shown that the current model underestimate the dose of neutrons outside the treatment rooms. In this work, a computational model for the aforementioned problem was created from Monte Carlo Simulations and Artificial Intelligence. The developed model was composed by three neural networks, each being formed of a pair of material and spectrum: Pb18, Pb15 and Fe18. In a direct comparison with the McGinley method, the Pb18 network exhibited the best responses for approximately 78% of the cases tested; the Pb15 network showed better results for 100% of the tested cases, while the Fe18 network produced better answers to 94% of the tested cases. Thus, the computational model composed by the three networks has shown more consistent results than McGinley method. (author)

  4. Presentation of the DosePet application (APP) for use in Nuclear Medicine: calculation of the amount of medicament for PET / CT patients; Apresentacao do aplicativo DosedPet para uso em Medicina Nuclear: calculo do volume de medicamento necessario para paciente de PETCT

    Energy Technology Data Exchange (ETDEWEB)

    Nascimento, Pedro Augusto do; Rodrigues, Araken dos S. Werneck, E-mail: pedroan88@gmail.com [Universidade de Brasilia (UnB), Brasilia, DF (Brazil). Faculdade Ceilandia. Programa de Pos Graduacao em Ciencias e Tecnologias em Saude

    2016-07-01

    This paper presents the application (APP) DosePet that calculates the amount of medicament for PET / CT in patients according to the predetermined radiation dose. The software has been designed using the web MIT App Inventor2 tool for Android platform. The application allows the workers to simulate the amount of radiation still existing in the premises after the applications, increasing security and reducing exposures, and enable greater efficiency in the use of the radiopharmaceutical. (author)

  5. Determinación de la capacidad requerida para la prestación del servicio de mantenimiento en plantas de generación de energía hidroeléctrica

    Directory of Open Access Journals (Sweden)

    Diana Lucía Guzmán Gómez

    2004-01-01

    Full Text Available En este artículo se presenta la metodología utilizada para determinar la capacidad requerida de personal para la prestación del servicio de mantenimiento electromecánico en tres plantas de generación hidroeléctrica. Se empleó el método de pronósticos para determinar el número de horas requeridas para efectuar las actividades de mantenimiento en el año 2003 y el estudio de variables para calcular el tiempo disponible de los operarios. Los resultados permitieron determinar el número óptimo de personal y plantear alternativas para efectuar el mantenimiento, las cuales fueron evaluadas por medio de los métodos multicriterio discretos.

  6. ALGORITMO PARA DISEÑAR LÍNEAS DE TRANSMISIÓN CON CABLES PROTECTORES SEGMENTADOS

    Directory of Open Access Journals (Sweden)

    Héctor Silvio Llamo Laborí

    2011-02-01

    Full Text Available En las líneas de transmisión a voltajes de 220 kV y mayores, el valor de las pérdidas en loscables protectores puede justificar económicamente su segmentación para reducirlas a cero.Se presentan los resultados y las características de un algoritmo para diseñar o comprobar eldiseño de esquemas de cables protectores segmentados a partir de calcular el voltaje máximoinducido electromagnéticamente en los mismos.  In the 220 kV and higher transmission lines, the lost value in the ground wires can justifieseconomically its segmentation to reduce it to zero.Are presented the characteristics and results of an algorithm to design or test the schemesof segmented ground wires calculating the electromagnetic voltage induced on it.

  7. Sistema de comercio electrónico para el sector textil: generar maniquíes 3D a partir de imágenes del sensor Kinect

    OpenAIRE

    Olabarria Iñarra, Ibon

    2014-01-01

    Este proyecto consiste en analizar la viabilidad técnica un sistema de información para mejorar el comercio electrónico de compra –venta de ropa. El nuevo sistema de comercio electrónico ayudará al usuario a escoger el tamaño de la prenda con más precisión. El sistema consiste en calcular las medidas esenciales del cuerpo del cliente utilizando el dispositivo Kinect. Posteriormente, estas medidas se introducen en el programa Makehuman que genera un maniquí en 3D. Con la idea de que en el futu...

  8. Verma procedure to determine thermodynamic properties of liquids; Procedimiento Verma para determinar propiedades termodinamicas de liquidos

    Energy Technology Data Exchange (ETDEWEB)

    Mahendra P, Verma [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2005-07-01

    In this paper are presented, the thermodynamic inconsistencies in formulation IAPWS-95 as well as the limitations in the experimental data of the thermodynamic properties of the water. In addition, a new methodology was developed: Verma procedure for the measurement of the calorific capacity of water. Thus, a procedure is presented to calculate other thermodynamic properties of liquids such as water. In the transformation processes of the planet Earth, water is an essential component. Nevertheless, the knowledge about its properties is still very limited. Recently, Verma developed a new program: SteamTablesIIE, to calculate the properties of water as a function of two independent variables between temperatures (T), pressure (P), volume (V), internal energy (U), enthalpy (H), Gibas energy (G) and entropy (S). Yet, thermodynamic inconsistencies were found in the formulation, same that are the limiting factors for the operation of the SteamTablesIIE in all the ranks of the independent variables. [Spanish] En este trabajo se presentan, tanto las inconsistencias termodinamicas en la formulacion IAPWS-95 como las limitaciones en los datos experimentales de las propiedades termodinamicas del agua. Ademas, se desarrollo una nueva metodologia: Procedimiento Verma para la medicion de la capacidad calorifica del agua. Asi, se presenta un procedimiento para calcular otras propiedades termodinamicas de liquidos tales como el agua. En los procesos de transformacion del planeta tierra, el agua es un componente esencial. Sin embargo, el conocimiento acerca de sus propiedades es todavia muy limitado. Recientemente, Verma desarrollo un nuevo programa: SteamTablesIIE, para calcular las propiedades del agua como una funcion de dos variables independientes entre temperaturas (T), presion (P), volumen (V), energia interna (U), entalpia (H), energia Gibas (G) y entropia (S). Con todo, se encontraron inconsistencias termodinamicas en la formulacion, mismas que son las limitantes para el

  9. Uso de meia dose de agonista do GnRH de depósito para supressão hipofisária em ciclos de fertilização in vitro Half-dose long-acting form of GnRH agonist for pituitary suppression in cycles of in vitro fertilization

    Directory of Open Access Journals (Sweden)

    Élvio Tognotti

    2007-04-01

    Full Text Available OBJETIVO: descrever a experiência de um serviço de reprodução assistida com a utilização de meia dose de agonista do GnRH de depósito para a supressão hipofisária em ciclos de fertilização in vitro (FIV. MÉTODOS: estudo prospectivo em que foram avaliados ciclos de FIV ou "intracytoplasmatic sperm injection" (ICSI utilizando meia dose de acetato de leuprolide de depósito, iniciado na fase lútea média do ciclo menstrual, no período de agosto de 2005 a março de 2006. Foi administrado FSH recombinante para indução ovariana controlada em dose variada. O hCG era administrado quando pelo menos um folículo atingisse 19 mm de diâmetro máximo. Realizou-se FIV ou ICSI nos oócitos maduros de acordo com fator de infertilidade. Transferiram-se até quatro embriões por paciente no segundo ou terceiro dia após a captação. O uso de progesterona foi iniciado no mesmo dia da coleta oocitária. A dosagem sérica de beta-hCG foi realizada no 14° dia após a coleta dos oócitos. Foram avaliados os seguintes parâmetros: número de ciclos aspirados, ciclos cancelados e ciclos transferidos, quantidade total de FSH utilizado, número de oócitos maduros, taxa de fertilização, número de embriões transferidos, taxa de implantação embrionária e taxa de gestação clínica. RESULTADOS: 109 ciclos de FIV/ICSI utilizaram o protocolo descrito. A média de idade das pacientes foi 34,9 anos. A taxa de cancelamento foi de 1,8% dos ciclos iniciados. Foram utilizadas 1.905 UI de gonadotrofina, em média, por ciclo iniciado. Um total de 86,5% dos oócitos obtidos eram maduros, e a taxa de fertilização foi de 76,3%. A média de embriões transferidos foi 2,7. As taxas de gestação por aspiração e por transferência foram 25,2 e 25,7%, respectivamente. Um total de 26,3% das gestações eram gemelares e 5,3%, trigemelares. CONCLUSÃO: a administração de meia dose (1,87 mg de acetato de leuprolide de depósito para bloqueio hipofisário pode ser

  10. Calculation of absorbed dose for skin contamination imparted by beta radiation through the VARSKIN modified code for 122 interesting isotopes for nuclear medicine, nuclear power plants and research; Calculo de dosis absorbida para contaminacion en piel impartida por radiacion beta mediante el codigo VARSKIN modificado para 122 isotopos de interes para medicina nuclear, plantas nucleares e investigacion

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez R, J T [Depto. de Metrologia, ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    1991-07-01

    In this work the implementation of a modification of the VARSKIN code for calculation of absorbed dose for contamination in skin imparted by external radiation fields generated by Beta emitting is presented. The modification consists on the inclusion of 47 isotopes of interest even Nuclear Plants for the dose evaluation in skin generated by 'hot particles'. The approach for to add these isotopes is the correlation parameter F and the average energy of the Beta particle, with relationship to those 75 isotopes of the original code. The methodology of the dose calculation of the VARSKIN code is based on the interpolation, (and integration of the interest geometries: punctual or plane sources), of the distribution functions scaled doses in water for beta and electrons punctual sources, tabulated by Berger. Finally a brief discussion of the results for their interpretation and use with purposes of radiological protection (dose insurance in relation to the considered biological effects) is presented.

  11. Development of a external exposure computational model for studying of input dose in skin for radiographs of thorax and vertebral column; Desenvolvimento de um modelo computacional de exposicao externa para estudo da dose de entrada na pele para radiografias de torax e coluna

    Energy Technology Data Exchange (ETDEWEB)

    Muniz, Bianca C.; Menezes, Claudio J.M., E-mail: bianca.cm95@gmail.com, E-mail: cjmm@cnen.gov.br [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil); Vieira, Jose W., E-mail: jwvieira@br.inter.net [Instituto Federal de Educacao, Ciencia e Tecnologia de Pernambuco (IFPE), Recife, PE (Brazil)

    2014-07-01

    The dosimetric measurements do not always happen directly in the human body. Therefore, these assessments can be performed using anthropomorphic models (phantoms) evidencing models computational exposure (MCE) using techniques of Monte Carlo Method for virtual simulations. These processing techniques coupled with more powerful and affordable computers make the Monte Carlo method one of the tools most used worldwide in radiation transport area. In this work, the Monte Carlo EGS4 program was used to develop a computer model of external exposure to study the entrance skin dose for chest and column X-radiography and, aiming to optimize these practices by reducing doses to patients, professionals involved and the general public. The results obtained experimentally with the electrometer Radcal, model 9015, associated with the ionization chamber for radiology model 10X5-6, showed that the proposed computational model can be used in quality assurance programs in radiodiagnostic, evaluating the entrance skin dose when varying parameters of the radiation beam such as kilo voltage peak (kVp), current-time product (mAs), total filtration and distance surface source (DFS), optimizing the practices in radiodiagnostic and meeting the current regulation.

  12. Determinação da dose de radiação gama para reduzir a população de Salmonella spp em carne de frango Determination of gamma radiation doses to reduce Salmonella spp in chiken meat

    Directory of Open Access Journals (Sweden)

    A.F. Santos

    2003-08-01

    Full Text Available O consumo de carne de frango contaminada com Salmonella é uma causa importante de salmonelose em todo o mundo. Essa doença transmitida por alimentos, é um problema de saúde pública e causa de perdas econômicas substanciais. O processo de irradiação é um método eficiente de conservação de alimentos por reduzir o número de microrganismos patogênicos e deteriorantes, sem que as características organolépticas e nutricionais do alimento sejam alteradas significativamente. Os objetivos desta pesquisa foram determinar o valor D10 de Salmonella Typhimurium ATCC 14028, inoculada em sobrecoxas de frango, e recomendar uma dose de radiação para ser aplicada a esse alimento a fim de torná-lo seguro do ponto de vista microbiológico. O valor D10 foi calculado a partir da curva de sobreviventes dessa bactéria em sobrecoxas de frango, após terem sido expostas às doses de 0kGy; 0,1kGy; 0,2kGy; 0,3kGy; 0,5kGy; 0,6kGy; 0,7kGy e 0,8kGy. O valor D10 variou de 0,241kGy a 0,480kGy. Considerando o maior valor D10 e o maior nível de contaminação de Salmonella spp encontrado em sobrecoxas de frango - 0,4NMP/g - adquiridas em feiras livres da cidade de São Paulo, a dose de radiação gama recomendada para garantir a segurança do produto em relação à presença de Salmonella spp é de 3,8kGy.The consumption of chicken meat contaminated with Salmonella spp is an important cause of salmonellosis worldwide. This food-borne disease is a public health problem and causes substantial economical loss. Irradiation process is an effective method for food preservation because it causes no significant change in organoleptic and nutritional food characteristics and destroys pathogenic and spoilage microorganisms. D10 values were calculated through the number of survivors for S. Typhimurium ATCC 14028, inoculated in chicken thighs, after being irradiated with different doses of gamma radiation - 0.0kGy; 0.1kGy; 0.2kGy; 0.3kGy; 0.5kGy; 0.7kGy and 0.8kGy . D10

  13. Cuantificación de especies químicas y propiedades termodinámicas de los gases para el cálculo de su temperatura en el interior de la cámara de combustión en MCI. // Chemical species quantification and thermodynamic properties of gases for temperature calc

    OpenAIRE

    F. Soto Pau; J. A. Silva; A. M. dos Santos; A. G. Sanches

    2003-01-01

    Se presentan las herramientas utilizadas en los cálculos y análisis de resultados, para la comparación del desempeñode un motor de combustión interna MCI utilizando etanol, gasolina y mezclas de ambos combustibles. Se hizonecesario en dicha investigación calcular la temperatura en el interior de la cámara de combustión para cada ensayo,con el objetivo de entender el comportamiento de la generación de CO, CO2, NOx, THC y emisión de O2 por elescape. Son varios autores los que brindan ecuaciones...

  14. ANÁLISIS DE INCERTIDUMBRE DE UN MODELO PARA LECHUGAS (Lactuca sativa L. CULTIVADAS EN INVERNADERO

    Directory of Open Access Journals (Sweden)

    Irineo Lorenzo López-Cruz

    2013-01-01

    Full Text Available Un análisis de incertidumbre para un modelo de crecimiento de un cultivo permite evaluar la variabilidad en sus parámetros y deducir una distribución de incertidumbre para cada variable que el modelo predice. Estos estudios se han practicado raramente en modelos para cultivos bajo invernadero. En el presente trabajo se presenta una metodología para llevar a cabo un análisis de incertidumbre para un modelo de un cultivo bajo invernadero y se aplica para determinar la variabilidad de los parámetros del modelo NICOLET desarrollado para explicar el crecimiento de lechugas (Lactuca sativa L.. Se definieron funciones de densidad de probabilidad para todos los parámetros del modelo y se asignaron sus valores mediante muestreo Monte Carlo, aleatorio e hipercubo latino, mediante un total de N = 2000 muestras. Posteriormente se ejecutaron 2000 simulaciones para calcular las salidas del modelo NICOLET para cada escenario. Finalmente, se analizó la distribución de las variables carbono en las vacuolas, carbono en la estructura, peso seco total y contenido de nitratos, mediante el cálculo de sus histogramas y medidas estadísticas. Las simulaciones se realizaron con el programa para análisis de incertidumbre y sensibilidad Simlab, disponible para el ambiente de programación Matlab. La variable carbono en las vacuolas presentó la mayor incertidumbre ya que su coeficiente de variación (CV en ambos muestreos, aleatorio e hipercubo latino, fue de 35.27 y 35.67 %, respectivamente, seguida del contenido de nitratos (CV = 18.16 % y CV = 19.07 %, el carbono estructural (CV = 5.52 % y CV = 5.67 % y el peso seco total (CV = 4.80 % y CV = 4.82 %.

  15. Calculation of the absorbed dose for contamination in skin imparted by beta radiation through the Varskin code modified for 122 isotopes of interest for nuclear medicine, nuclear plants and research; Calculo de dosis absorbida para contaminacion en piel impartida por radiacion beta mediante el codigo Varskin modificado para 122 isotopos de interes para medicina nuclear, plantas nucleares e investigacion

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez R, J T

    1992-06-15

    In this work the implementation of a modification of the Varskin code for calculation of absorbed dose by contamination in skin imparted by external radiation fields generated by beta emitting is presented. The necessary data for the execution of the code are: isotope, dose depth, isotope activity, geometry type, source radio and time of integration of the isotope, being able to execute combinations of up to five radionuclides. This program it was implemented in Fortran 5 by means of the FFSKIN source program and the executable one in binary language BFFSKIN being the maximum execution time of 5 minutes. (Author)

  16. Patterns of Lethality and Absorbed Dose Distributions in Mice for Monoenergetic Neutrons; Letalite et Distribution de la Dose Absorbee chez la Souris pour des Neutrons Monoenergetiques; Letal'nost' i raspredelenie pogloshchennoj dozy pri obluchenii myshej monoehnergeticheskimi neitronami; Letalidad y Distribucion de las Dosis Absorbidas por el Raton para Neutrones Monoenergeticos

    Energy Technology Data Exchange (ETDEWEB)

    Frigerio, N. A.; Jordan, D. L. [Argonne National Laboratory, Argonne, IL (United States)

    1964-03-15

    V {+-} 50 keV pour couvrir la region des resonances de N et de O. On a constate que la courbe de letalite est une fonction marquee de Tenergie des neutrons et une fonction egalement marquee mais independante de la distribution de la dose. Toutefois, quelles que soient la dose, l'energie et la distribution, tous les animaux qui ont survecu 5 j ont ensuite survecu au moins 144 j, puis sont morts sous les effets a long terme habituels. Cela donne a penser que les neutrons rapides monoenergetiques n ayant pas subi de contamination gamma ou epithermique produisent presque exclusivement la 'mort intestinale ' precoce. (author) [Spanish] La presencia de intensas resonancias para el C, el N y el O, en el intervalo de 100 a 1500keV, ha permitido estudiar las interacciones especificas neutron-nuclido, que se manifiestan por variaciones de la letalidad, maximos de la EBR, etc. Mediante protones resueltos de 62 {mu}A, procedentes de un acelerador de van de Graaf, de 1882 keV a 2738 keV, se obtuvieron neutrones monoenergeticos por intermedio de la reaccion {sup 7}Li(p, n){sup 7}Be. Los autores expusieron al efecto de los neutrones monoenergeticos a hembras de raton virgenes, CF-1, en capsulas de celuloide, a distancias de 3,1 a 11,3 cm de la fuente, bajo angulos de 0 a 1 radian. Durante la exposicion bilateral, los animales giraban simultaneamente en orbitas circulares o elipticas normales al eje del haz. De esta manera se podia regular la distribucion de la dosis en el cuerpo del animal. Los autores midieron el flujo absoluto con contadores de fision de {sup 235}U y por receuento absoluto mediante alambres y laminas de oro activados, revestidos de Gd. Determinaron las dosis absorbidas con microcamaras de ionizacion y con un dosimetro de FeSO{sub 4}-NH{sub 4}SCN de alta sensibilidad, preparado especialmente para este fin. Para la medicion de las dosis relativas, usaron contadores gaseosos de Hurst para protones de retroceso y centelleadores de {sup 10}B, {sup 6}Li y de protones de

  17. “implementación de un sistema de aire comprimido para un taller de mecánica automotriz”

    OpenAIRE

    Zhimnaycela Reino, Carlos Fernando; Camposano, Filian

    2013-01-01

    En este proyecto de graduación se encontrara una guía práctica para la instalación, puesta en marcha y mantenimiento de un sistema de aire comprimido. Para calcular el consumo total del sistema, se hacen las estimaciones de equipos a utilizar, la forma que debe determinarse la unidad compresora con su respectivo factor de seguridad en el caso de aumentar el consumo del sistema. Se diseña la red de tuberías, se calcula el diámetro de la tubería, la caída de presión y selecciona la tuberí...

  18. Aportes para la estimación de la huella de carbono en los grandes asentamientos urbanos de Argentina

    Directory of Open Access Journals (Sweden)

    Rosana Ferraro

    2013-07-01

    Full Text Available El cambio climático y su efecto más inmediato, el calentamiento global, plantean desafíos para la gestión ambiental de las ciudades. Uno de ellos es estimar su huella de carbono con la finalidad de morigerar los potenciales impactos. El presente trabajo propone calcular las emisiones de CO2 producidas por las actividades antrópicas de los 15 asentamientos urbanos de Argentina de más de 300.000 habitantes. Para ello se analizaron por localidad los consumos de energía eléctrica y se calcularon las emisiones de CO2 por sector de demanda eléctrica. Los resultados muestran que Argentina, en general, y los grandes asentamientos, en particular, tienen una baja contribución de emisiones de CO2, que se asocian en orden decreciente con la actividad industrial, residencial y comercial.

  19. Descripción de la zona de alta difusión en un modelo bidimensional para hojas de corriente

    Science.gov (United States)

    Montero, M. F.; Paola, C. A.; Platzeck, A. M.

    Los modelos bidimensionales para describir hojas de corriente de alta simetría no suministran una descripción detallada de las regiones donde la difusión es considerablemente importante. Tal es el caso de los modelos desarrollados en la década del '60 por Sweet, Parker, Petschek y Sonnerup. En esta comunicación presentamos una solución de las ecuaciones MHD en el entorno del origen, construyendo series bidimensionales para todas las magnitudes físicas involucradas. Valiéndonos de la alta simetría y de las características del problema, logramos reducir el número de coeficientes a calcular. Utilizamos un programa autoconsistente para extender el cálculo a regiones vecinas con difusión moderada o despreciable.

  20. Curva dose-resposta do exercício em hipertensos: análise do número de sessões para efeito hipotensor Curva dosis-respuesta del ejercicio en hipertensos: análisis del número de sesiones para efecto hipotensor Dose-response curve to exercise in hypertensive individuals: analysis of the number of sessions to the hypotensive effect

    Directory of Open Access Journals (Sweden)

    Paulo Ricardo Nazário Viecili

    2009-05-01

    Full Text Available FUNDAMENTO: O efeito do exercício na pressão arterial já é conhecido, entretanto a curva dose-resposta do efeito hipotensor do exercício em hipertensos ainda não está clara. OBJETIVO: Avaliar a curva dose-resposta do número de sessões necessárias para causar efeito hipotensor em indivíduos hipertensos. MÉTODOS: Participaram deste estudo 88 indivíduos, com 58 ± 11 anos, divididos em grupo experimental (GE - composto de 48 integrantes de um programa de exercício físico (PEF de 3 meses, 3 vezes por semana, com 40' de exercício aeróbio a 70% do VO2máx e exercícios musculares a 40% da CVM - e grupo-controle (GC - 40 indivíduos que não realizaram PEF. As pressões arteriais sistólica (PAS e diastólica (PAD foram mensuradas antes de cada uma das 36 sessões no GE e avaliadas por MAPA no GC. Observaram-se as diferenças na PA, o índice de variação (D% e o efeito hipotensor máximo (EHM% entre as sessões. Os dados foram expressos por M ± DP, e usou-se teste t e correlação, considerando p FUNDAMENTO: Ya se conoce el efecto del ejercicio en la presión arterial, sin embargo, la curva dosis-respuesta del efecto hipotensor del ejercicio en hipertensos no está aclarada aún. OBJETIVO: Evaluar la curva dosis-respuesta del número de sesiones necesarias para causar efecto hipotensor en individuos hipertensos. MÉTODOS: El estudio estaba conformado por 88 individuos, con 58 ± 11 años, divididos en grupo experimental (GE -conformado por 48 integrantes de un programa de ejercicio físico (PEF de tres meses, tres veces por semana, con 40' de ejercicio aerobio al 70% del VO2máx y ejercicios musculares al 40% de la capacidad voluntaria máxima (CVM; y grupo-control (GC con 40 individuos que no realizaron el PEF. Se midieron las presiones arteriales sistólica (PAS y diastólica (PAD del GE antes de cada una de las 36 sesiones y en el GC se las evaluaron por monitoreo ambulatorio de presión arterial (MAPA. Se observaron las

  1. Uso de antagonista de GnRH (cetrorelix em dose única para evitar ovulações prematuras em ciclos de fertilização assistida Single dose of GnRH antagonist (cetrorelix to avoid premature ovulation in assisted fertilization cycles

    Directory of Open Access Journals (Sweden)

    Pedro Luís Rosan

    2003-09-01

    Full Text Available OBJETIVO: verificar a eficácia de uma dose única subcutânea de acetato de cetrorelix em evitar a ovulação prematura em ciclos de fertilização assistida. MÉTODOS: estudo prospectivo, randomizado e controlado, pelo qual foram avaliados 20 ciclos de estimulação ovariana em mulheres submetidas a fertilização assistida, 10 das quais utilizaram o esquema tradicional de bloqueio hipofisário com análogos de GnRH em doses diárias (grupo controle e 10 utilizaram antagonista de GnRH em dose única de 3 mg no 7º dia de estimulação ovariana (grupo cetrorelix. Foram dosados FSH, LH, estradiol e progesterona no soro no primeiro e sétimo dia da estimulação, no dia da injeção de HCG e no dia da captação de oócitos. Os grupos foram comparados entre si quanto a eficácia do bloqueio hipofisário (nível de progesterona no dia da aplicação do HCG e desempenho nos ciclos de fertilização assistida (ampolas de gonadotrofinas utilizadas, folículos maiores que 18 mm, oócitos captados, taxas de fertilização, implantação e gravidez utilizando os testes de Mann-Whitney e exato de Fisher. RESULTADOS: não houve diferença significativa entre os grupos controle e cetrorelix, respectivamente, para a mediana da idade (31,5 e 34 anos, índice de massa corpórea (24 e 22, ampolas de gonadotrofinas utilizadas (34 e 32, folículos recrutados (3,5 e 3,0, oócitos captados (11 e 5, embriões obtidos (4 e 3, taxas de fertilização (93,7 e 60%, p = 0,07 e gravidez (50 e 60%, p = 0,7. Em ambos os grupos observou-se bloqueio hipofisário eficaz durante o período de estimulação ovariana. CONCLUSÕES: estes resultados confirmam a eficácia da dose única de 3 mg de acetato de cetrorelix em prevenir ovulações prematuras em pacientes submetidas a fertilização assistida, mostrando tendência a obtenção de menor número de embriões e menores taxas de fertilização no grupo cetrorelix em relação ao grupo controle. As taxas de implantação e

  2. Prototipo de motor de realidad aumentada tridimensional para dispositivos móviles

    OpenAIRE

    Suárez Canosa, Xoan Iago

    2016-01-01

    La Realidad Aumentada es la tecnología que nos permite superponer elementos gráficos sobre el mundo real. Para que ésta pueda funcionar adecuadamente es necesario conocer con precisión cuál es la posición de la cámara desde la que vemos el mundo y cómo se conforman las imágenes que nos muestra. En este trabajo mostramos cómo calcular la posición de la cámara a partir de diferentes marcas tanto naturales como artificiales, vemos cual es la mejor forma de proyectar sobre estas ma...

  3. Carga limite para juntas mecânicas em laminados de fibra de carbono

    OpenAIRE

    Arthur Chaves de Mas Santacreu

    1989-01-01

    Neste trabalho são testadas várias juntas parafusadas com laminados de fibra de carbono. São investigadas as influências dos parâmetros geométricos e dos parâmetros de constituição do laminado no comportamento da curva carga versus deformação do furo carregado. Paralelamente é desenvolvido um modelo de elementos finitos linear elástico para calcular a deformação do furo carregado a partir das propriedades mecânicas do material e da geometria da junta. É proposto um critério de previsão de car...

  4. Uso de software libre para el aprendizaje de la integral definida

    OpenAIRE

    Medina, Mabel Azucena; Rubio, Héctor Eduardo

    2013-01-01

    Se desarrolla la experiencia de una unidad didáctica en el marco de la teoría de Brousseau y de la Enseñanza para la Comprensión. El Tópico Generativo es la integral definida. Las Metas de Comprensión son la definición de la integral definida y las formas de evaluación de la integral definida. Los Desempeños de Comprensión son actividades autónomas de evaluación de integrales definidas. El propósito de esta actividad es que los alumnos comprendan que pueden calcular aproximadamente una integr...

  5. Sistemas fotovoltaicos conectados à rede para Moçambique

    Directory of Open Access Journals (Sweden)

    Marcos Herbert Smith dos Santos

    2013-12-01

    Full Text Available A energia solar fotovoltaica é uma fonte limpa e importante opção como fonte alternativa de energia elétrica. Um estudo das condições energéticas de Moçambique, na África, através do ministério de energia, daquele governo, fornece dados importantes para conhecimento das condições de suas regiões desprovidas de energia elétrica. Os dados solarimétricos são usados para se definir um sistema fotovoltaico. Estes podem ser obtidos do órgão meteorológico da região, que fornece dados para as cidades das estações meteorológicas espalhadas pelo país e de laboratórios de pesquisa internacionais de campo que fornecem dados solarimétricos, usando satélites de varredura, que são capazes de cobrir todo globo terrestre e disponibilizarem aplicativos que permitem, através das coordenadas do local, identificar exatamente a irradiação solar em qualquer ponto. Neste estudo, dados laboratoriais, validados através de comparações com os dados de órgãos oficiais da região, permitiram se montar um banco de dados solarimétricos e se calcular o potencial fotovoltaico de geração de energia de cada local. Foram também observadas regiões, desprovidas de redes elétricas, muito propícias ao aproveitamento da energia solar para geração direta de eletricidade, para ser conectada à rede de distribuição.

  6. Estudo comparativo da qualidade de imagem dos modos de aquisição da PET: validação de um protocolo para reduzir a dose de radiação Comparative study on imaging quality in PET acquisition modes: validation of a protocol for reducing the radiation dose

    Directory of Open Access Journals (Sweden)

    Solange Amorim Nogueira

    2009-04-01

    Full Text Available OBJETIVO: O presente experimento visa a validar um protocolo de aquisição em 3D na tomografia por emissão de pósitrons, em substituição ao modo 2D, de forma a reduzir a dose de radiação nos pacientes, sem perda da qualidade de imagens. MATERIAIS E MÉTODOS: Foram realizadas 27 simulações em equipamento Discovery ST, nos modos 2D com quatro minutos de aquisição e 3D com dois e quatro minutos. Utilizou-se um simulador do protocolo da National Electrical Manufacturers Association. No interior deste simulador estão inseridas seis esferas com diferentes diâmetros para a determinação da qualidade de imagem. As aquisições foram comparadas por três médicos nucleares, sem que eles identificassem o modo de aquisição. Cada observador atribuiu o valor igual a 1 quando alguma esfera não foi identificada ou valor 2 para esferas visíveis. RESULTADOS: A análise qualitativa pelo kappa generalizado demonstrou que a frequência de esferas visíveis foi maior no modo 3D com quatro minutos (85% e a porcentagem de concordância também foi maior (88,9%, com kappa generalizado = 0,725 [0,507;0,942]. CONCLUSÃO: O modo 3D com quatro minutos de aquisição e com menores atividades de FDG-18F pode ser utilizado em pacientes com biótipo equivalente ao simulador, sem perda de qualidade de imagem.OBJECTIVE: The present study is aimed at validating a 3D acquisition protocol for positron emission tomography as a replacement for the 2D mode, to reduce the radiation dose delivered to patients, without any loss in the quality of images. MATERIALS AND METHODS: The study comprised 27 simulations in a Discovery ST equipment with four-minute 2D acquisitions, and two-minute and four-minute 3D acquisitions, utilizing a chest phantom according to the National Electrical Manufacturers Association protocol. Six spheres with different diameters were inserted into this phantom as a means for determining the images quality. The images were blindly reviewed by three

  7. Brazilian experience using high-dose sequential therapy (HDS followed by autologous hematopoietic stem cell transplantation (ASCT for malignant lymphomas Experiência brasileira utilizando terapia sequencial de alta dose seguido de transplante autólogo de célula-tronco hematopoética para linfomas malignos

    Directory of Open Access Journals (Sweden)

    Cármino A. de Souza

    2009-08-01

    óstico; 62% com grande massa e 42% com IPI de alto risco ou intermediário. Após alta dose de ciclofosfamida (HDCY, nove pacientes faleceram. Oitenta pacientes realizaram o transplante, sendo que 47% estavam em RC e 15% faleceram devido à toxicidade. A sobrevida global foi de 45% em oito anos para estes pacientes. Trinta e cinco pacientes não realizaram o transplante por causas diversas. Sobrevida global para todos os pacientes foi de 42%, DLBCL, 40%; T-cell, 40% e zona do manto, 20% (P=NS. Pacientes que obtiveram RC após HDCY tiveram melhor sobrevida global e livre de progressão (38% e 17%, respectivamente do que os que permaneceram em PD (P<0.0001. O modelo de Cox resultou que o número de linhas terapêuticas antes da HDCY (RR 1.41 IC 95%: 1.04-1.90, P=0.02 e PD antes da HDCY (RR 2.70, IC 95%: 1.49-4.91, P<0.001 e após HDCY (RR 5.38, IC 95%: 2.93-9.87, P<0.0001. Nosso estudo sugere que HDS é um método eficiente de tratamento para melhorar o status e reduzir a massa tumoral. Em relação à toxicidade, é factível, especialmente em pacientes de prognóstico ruim

  8. Calibration curve to establish the exposure dose at Co{sup 60} gamma radiation; Curva de calibracion para establecer dosis de exposicion a radiacion gamma de Co{sup 60}

    Energy Technology Data Exchange (ETDEWEB)

    Guerrero C, C; Brena V, M [Departamento de Biologia, Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, Mexico D.F. (Mexico)

    2000-07-01

    The biological dosimetry is an adequate method for the dose determination in cases of overexposure to ionizing radiation or doubt of the dose obtained by physical methods. It is based in the aberrations analysis produced in the chromosomes. The behavior of leisure in chromosomes is of dose-response type and it has been generated curves in distinct laboratories. Next is presented the curve for gamma radiation produced in the National Institute of Nuclear Research (ININ) laboratory. (Author)

  9. Preparation of an application for the control of the dose delivered by equipment of computed tomography (CT); Elaboracion de una aplicacion para el control de la dosis impartida por equipos de tomografia computerizada (TC)

    Energy Technology Data Exchange (ETDEWEB)

    Torres Cabrera, R.; Agulla Otero, M.; Hernando Gonzalez, I.

    2013-07-01

    Although TC are native digital equipment, the collection and treatment of the doses given to the patients it continues to present difficulties to date, especially in the still very large number of teams that do not produce a formal report of dose (SR). This work shows the experience gained in the development of an application that allows the calculation, monitoring and control of the dose given to patients by teams of TC. (Author)

  10. Diseño de una metodología para el cálculo de los costos de calidad

    Directory of Open Access Journals (Sweden)

    Nancy Oña Aldama

    1998-08-01

    Full Text Available Se estableció una metodología para el cálculo y análisis de los costos de calidad y a partir de ésta se pudo calcular y analizar los costos de prevención, evaluación y por fallos de 1995, en la que se utilizó para el cumplimiento de los objetivos diferentes técnicas gráficas, como diagrama circular, Pareto, flujo informativo y otras. Se compararon los valores obtenidos con 3 indicadores económicos.A methodology for the calculation and analysis of quality costs was established. By using this methodology it was possible to calculate and analyze the prevention and evaluation costs and the costs by failures in 1995. Different graphical techiniques, such as circular diagram, Pareto, information flow and others were used in order to fulfil the objectives. The values obtained were compared with 3 economic indicators.

  11. Class solution to decrease rectal dose in prostate radiotherapy treatments 3D-CRT; Solucion de clase para disminuir dosis en recto en tratamientos de prostata con radioterapia 3D-CRT

    Energy Technology Data Exchange (ETDEWEB)

    Andres Rodriguez, C.; Tortosa Oliver, R.; Alonso Hernandez, D.; Mari Palacios, A.; Castillo Belmonte, A. del

    2011-07-01

    This paper contains a method developed in our center with conventional 3D radiotherapy techniques to increase the dose conformation around the target volume in prostate cancer treatments significantly reduced the doses to the rectum. To evaluate the goodness of the method, the results are compared with two classical techniques of treatment.

  12. Calculations of received dose for different points in the enrichment uranium oxide warehouse at 4%; Calculos de dosis recibida para diferentes puntos en el almacen de oxido de uranio enriquecido al 4%

    Energy Technology Data Exchange (ETDEWEB)

    Alonso V, G. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    1990-06-15

    In order to verifying that the received dose so much inside as outside of the warehouse of enriched uranium dioxide to 4% it doesn't represent risk to the personnel, the modelling of this and the corresponding calculations for the extreme case of dose at contact are made. (Author)

  13. Independent dose calculation in IMRT for the Tps Iplan using the Clarkson modified integral; Calculo independiente de dosis en IMRT para el TPS Iplan usando la integral modificada de Clarkson

    Energy Technology Data Exchange (ETDEWEB)

    Adrada, A.; Tello, Z.; Garrigo, E.; Venencia, D., E-mail: jorge.alberto.adrada@gmail.com [Instituto Privado de Radioterapia, Obispo Oro 423, X5000BFI Cordoba (Argentina)

    2014-08-15

    Intensity-Modulated Radiation Therapy (IMRT) treatments require a quality assurance (Q A) specific patient before delivery. These controls include the experimental verification in dose phantom of the total plan as well as dose distributions. The use of independent dose calculation (IDC) is used in 3D-Crt treatments; however its application in IMRT requires the implementation of an algorithm that allows considering a non-uniform intensity beam. The purpose of this work was to develop IDC software in IMRT with MLC using the algorithm proposed by Kung (Kung et al. 2000). The software was done using Matlab programming. The Clarkson modified integral was implemented on each flowing, applying concentric rings for the dose determination. From the integral of each field was calculated the dose anywhere. One time finished a planning; all data are exported to a phantom where a Q A plan is generated. On this is calculated the half dose in a representative volume of the ionization chamber and the dose at the center of it. Until now 230 IMRT planning were analyzed carried out ??in the treatment planning system (Tps) Iplan. For each one of them Q A plan was generated, were calculated and compared calculated dose with the Tps, IDC system and measurement with ionization chamber. The average difference between measured and calculated dose with the IDC system was 0.4% ± 2.2% [-6.8%, 6.4%]. The difference between the measured and the calculated doses by the pencil-beam algorithm (Pb) of Tps was 2.6% ± 1.41% [-2.0%, 5.6%] and with the Monte Carlo algorithm was 0.4% ± 1.5% [-4.9%, 3.7%]. The differences of the carried out software are comparable to the obtained with the ionization chamber and Tps in Monte Carlo mode. (author)

  14. Dose limits

    International Nuclear Information System (INIS)

    Fitoussi, L.

    1987-12-01

    The dose limit is defined to be the level of harmfulness which must not be exceeded, so that an activity can be exercised in a regular manner without running a risk unacceptable to man and the society. The paper examines the effects of radiation categorised into stochastic and non-stochastic. Dose limits for workers and the public are discussed

  15. Nitrogen doses and weed control via intercropping with gliricidia for corn production Doses de nitrogênio e controle de plantas daninhas, através da consorciação com gliricídia, para produção de milho

    Directory of Open Access Journals (Sweden)

    P.S.L. Silva

    2010-01-01

    de nitrogênio sobre os rendimentos de grãos e de milho verde. Devido ao crescente interesse sobre a degradação ambiental, muitas práticas agrícolas adotadas no passado estão sendo reexaminadas. No que se refere ao controle de plantas daninhas, estratégias que empregam controle mecânico, incluindo consorciação, estão sendo objeto de renovado interesse. O objetivo deste estudo foi avaliar os efeitos da aplicação de doses de nitrogênio (0, 40, 80, and 120 kg N ha-1; como sulfato de amônio e do controle de plantas daninhas sobre o crescimento e os rendimentos de espigas verdes e de grãos da cultivar de milho AG 1051. Utilizou-se o delineamento experimental de blocos completos casualizados com parcelas subdivididas e nove repetições. Além das doses de nitrogênio, a cultivar AG 1051 foi submetida aos seguintes tratamentos, aplicados às subparcelas: sem capina, duas capinas (aos 20 e 40 dias após a semeadura, e consorciação com gliricídia (Gliricidia sepium. A gliricídia foi semeada por ocasião da semeadura do milho, entre as fileiras da gramínea, usando-se duas sementes por cova, em covas distanciadas por 0,30 m. A gliricídia não controlou as plantas daninhas e propiciou crescimento e rendimentos de espigas verdes e grãos similares aos obtidos com a ausência de capinas. Todavia, o número de espigas maduras obtido com a consorciação com a gliricídia não diferiu do obtido com a realização de duas capinas. O controle de plantas daninhas não teve efeito sobre a altura da planta e sobre o número de espigas verdes empalhadas comercializáveis, com a aplicação de 120 kg N ha-1; indicando que o nitrogênio melhorou a capacidade competitiva do milho. A realização de duas capinas proporcionou as maiores médias para o peso total de espigas verdes, número de espigas verdes despalhadas comercializáveis, pesos de espigas verdes empalhadas e despalhadas, comercializáveis, rendimento de grãos e seus componentes, que os demais tratamentos

  16. Estudio Te\\'orico del espectro de emisi\\'on para un sistema microcavidad-punto cu\\'antico en una aproximaci\\'on de campo medio (Theoretical study of emission spectrum for a quantum dot-microcavity system in a mean field approximation)

    OpenAIRE

    Rojas-Arias, Juan S.; Rodriguez, B.; Vinck-Posada, Herbert

    2015-01-01

    En este trabajo, se obtiene una expresi\\'on num\\'erica para calcular el espectro de emisi\\'on de un sistema microcavidad-punto cu\\'antico usando una teor\\'ia de campo medio en el formalismo de la matriz densidad. El sistema modelado es un micropilar semiconductor que contiene un \\'unico punto cu\\'antico en el interior de la microcavidad, este sistema presenta p\\'erdida de fotones a trav\\'es de los espejos de la cavidad y bombeo de excitones al punto cu\\'antico. Obtenemos una ecuaci\\'on maestr...

  17. Development of a methodology for doss assessment viewing the use of NORM on building materials; Desenvolvimento de uma metodologia para avaliacao de doses visando o uso de NORM em materiais de construcao

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Antonio Fernando Costa de

    2009-07-01

    The objective of this study was to develop a methodology for estimating the radiological impact on man of the residues of naturally occurring radioactive materials (NORMs) that potentially can be used for the construction of homes and roads. Residues of this type, which are being produced in great quantities by the Brazilian mining industry, are typically deposited in non-appropriated conditions such that they may have a long-time adverse impact on the environment, and hence on man. A mathematical model was developed to calculate the doses resulting from the use of NORM residues, thus allowing a preliminary analysis of the possibility to recycle the residues. The model was used to evaluate the external dose due gamma radiation, the dose to skin caused by beta radiation, and the internal dose due to inhalation of radon and its decay products. The model was verified by comparisons with results of other studies about doses due to gamma and beta radiation from finite and infinite radioactive sources, with relatively good agreement. In order to validate the proposed methodology, a comparison was made against experimental results for a house constructed in accordance with CNEN regulations using building materials containing NORM residues. Comparisons were made of the dose due to gamma radiation and the radon concentration in the internal environment. Finally, the methodology was used also to estimate the dose caused by gamma radiation from a road constructed in the state of Rondonia, Brazil, which made use of another NORM residue. (author)

  18. Jaws calibration method to get a homogeneous distribution of dose in the junction of hemi fields; Metodo de calibracion de mandibulas para conseguir una distribucion homogenea de dosis en la zona de union de hemicampos

    Energy Technology Data Exchange (ETDEWEB)

    Cenizo de Castro, E.; Garcia Pareja, S.; Moreno Saiz, C.; Hernandez Rodriguez, R.; Bodineau Gil, C.; Martin-Viera Cueto, J. A.

    2011-07-01

    Hemi fields treatments are widely used in radiotherapy. Because the tolerance established for the positioning of each jaw is 1 mm, may be cases of overlap or separation of up to 2 mm. This implies heterogeneity of doses up to 40% in the joint area. This paper presents an accurate method of calibration of the jaws so as to obtain homogeneous dose distributions when using this type of treatment. (Author)

  19. Absorbed doses profiles vs Synovia tissue depth for the Y-90 and P-32 used in radiosynoviortesis treatment; Perfiles de dosis absorbida vs profundidad de tejido sinovial para el Y-90 y el P-32 empleados en tratamiento de radiosinoviortesis

    Energy Technology Data Exchange (ETDEWEB)

    Torres B, M.B.; Ayra P, F.E. [Centro de Isotopos (Cuba); Garcia R, E. [Hospital General Docente Enrique Cabrera (Cuba); Cornejo D, N. [CPHR, (Cuba); Yoriyaz, H. [IPEN, (Brazil)]. e-mail: nestor@cphr.edu.cu

    2006-07-01

    The radiosynoviortesis treatment has been used during more of 40 years as an alternative to the chemical and surgical synovectomy to alleviate the pain and to reduce the inflammation in suffered patients of rheumatic arthropathies, haemophilic arthropathies and other articulation disorders. It consists on the injection of radioactive isotopes inside a synovial cavity. For to evaluate the dosimetry of the radiosynoviortesis treatment is of great interest to know the absorbed dose in the volume of the target (synovia). The precise calculation of the absorbed dose in the inflamed synovia it is difficult, for numerous reasons, since the same one will depend on the thickness of the synovial membrane, the size of the articular space, the structure of the synovial membrane, the distribution in the articulation, the nature of the articular liquid, etc. Also the presence of the bone and the articular cartilage, components also of the articulation, it even complicated more the calculations. The method used to evaluate the dosimetry in radioactive synovectomy is known as the Monte Carlo method. The objective of our work consists on estimating with the Monte Carlo code MCNP4B the absorbed dose of the Y-90 and the P-32 in the depth of the synovial tissue. The results are presented as absorbed dose for injected millicurie (Gy/mCi) versus depth of synovial tissue. The simulation one carries out keeping in mind several synovia areas, of 50 cm{sup 2} to 250 cm{sup 2} keeping in mind three states of progression of the illness. Those obtained values of absorbed dose using the MCNP4B code will allow to introduce in our country an optimized method of dose prescription to the patient, to treat the rheumatic arthritis in medium and big articulations using the Y-90 and the P-32, eliminating the fixed doses and fixed radionuclides for each articulation like it happens in many clinics of Europe, as well as the empiric doses. (Author)

  20. Characterization by Monte Carlo of the dose after a glass shield lead for gamma ray; Caracterizacion por Monte Carlo de la dosis tras un blindaje de vidrio de plomo para rayos gamma

    Energy Technology Data Exchange (ETDEWEB)

    Esteve Sanchez, S.; Gil Conde, M.; Contreras Gonzalez, J. L.; Rosado, J.; Pazyi, V.

    2013-07-01

    When a gamma-ray beam crosses the border between two media characterized by atomic number very different is they produce effects on the distribution of doses near the border difficult to predict with simple models. The case of rays gamma affecting a lead glass is particularly interesting for its application to shielding of common use. interested in studying the importance of the residual dose after the shield. (Author)

  1. Controllable dose

    International Nuclear Information System (INIS)

    Alvarez R, J.T.; Anaya M, R.A.

    2004-01-01

    With the purpose of eliminating the controversy about the lineal hypothesis without threshold which found the systems of dose limitation of the recommendations of ICRP 26 and 60, at the end of last decade R. Clarke president of the ICRP proposed the concept of Controllable Dose: as the dose or dose sum that an individual receives from a particular source which can be reasonably controllable by means of any means; said concept proposes a change in the philosophy of the radiological protection of its concern by social approaches to an individual focus. In this work a panorama of the foundations is presented, convenient and inconveniences that this proposal has loosened in the international community of the radiological protection, with the purpose of to familiarize to our Mexican community in radiological protection with these new concepts. (Author)

  2. Regression models in the determination of the absorbed dose with extrapolation chamber for ophthalmological applicators; Modelos de regresion en la determinacion de la dosis absorbida con camara de extrapolacion para aplicadores oftalmologicos

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez R, J T; Morales P, R

    1992-06-15

    The absorbed dose for equivalent soft tissue is determined,it is imparted by ophthalmologic applicators, ({sup 90} Sr/{sup 90} Y, 1850 MBq) using an extrapolation chamber of variable electrodes; when estimating the slope of the extrapolation curve using a simple lineal regression model is observed that the dose values are underestimated from 17.7 percent up to a 20.4 percent in relation to the estimate of this dose by means of a regression model polynomial two grade, at the same time are observed an improvement in the standard error for the quadratic model until in 50%. Finally the global uncertainty of the dose is presented, taking into account the reproducibility of the experimental arrangement. As conclusion it can infers that in experimental arrangements where the source is to contact with the extrapolation chamber, it was recommended to substitute the lineal regression model by the quadratic regression model, in the determination of the slope of the extrapolation curve, for more exact and accurate measurements of the absorbed dose. (Author)

  3. Calculation of dose distribution in the patient for verification of plans of intensity modulated radiation therapy; Calculo de la distribucion de dosis en el paciente para la verificacion de planes de radioterapia de intensidad modulada

    Energy Technology Data Exchange (ETDEWEB)

    Perez Moreno, J. M.; Zucca Aparicio, D.; Garcia Ruiz-Zorrila, J.; Fernandez Leton, J. P.; Minambres Moro, A.

    2013-07-01

    The precision in the delivery of radiation therapy treatments intensity modulated depends on, among other things, of the proper administration of the sequence of radiation calculated on the planning system. In recent years the electronic devices of imaging portal have shown as a useful tool for the measurement of dose distribution with high resolution. An algorithm has been developed to calculate the distribution of dose in the patient's Anatomy, using the accelerator as measuring equipment electronic imaging of portal In this way the acceptance criteria can be changed in the dosimetry verifications pretreatment of radiation therapy treatments, from those based on evaluation of gamma index to others based on the evaluation of the distribution of dose in the patient. (Author)

  4. Valorization of the GAFCHROMIC XR-R film for radiation dose estimation in the skin; Valoracion de las peliculas Gafchromic XR-R para estimacion de dosis a piel en ''ablacion por radiofrecuencia''

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez Garcia, M.; Otero Martinez, C.; Camino, X. M.; Sendon del Rio, J. R.; Luna Vega, V.; Lobato Busto, R.; Mosquera Sueiro, J.; Pombar Camean, M.

    2006-07-01

    The adequacy of the couple formed by the GAFCHROMIC XR-R film and the MICROTEK Scan Maker 8700 for skin dose determination has been evaluated. The main advantages are the ease of use the films, since it can be manipulated without special care and the ability to archive it in the dosimetric history of the patient. The main limiting factors coming from the scanner are the reproducibility over time and noise in the digitization; it is shown that this last component can be minimized at the cost of resolution. From the film itself, the limiting factors are the inter and intra film uniformity. Contributing an 6,5% to the overall uncertainty in dose determination. Overall, it has been shown that skin dose determination is possible with this film with an uncertainty below 10%. (Author)

  5. Stability of the response and dependence of the optical signal as function of dose rate of the alanine gel dosimeter for electron clinic beams; Estabilidade da resposta e dependencia do sinal optico em funcao da taxa de dose do dosimetro alanina gel para feixes clinicos de eletrons

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Cleber Feijo; Dias, Daniel Menezes; Campos, Leticia Lucente, E-mail: cfsilva@ipen.b, E-mail: dmdias@ipen.b, E-mail: lcrodri@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2009-07-01

    This work evaluates the stability of response and the dependence on the optical response of dose rate of the alanine gel solution developed at the IPEN, Sao Paulo, Brazil, for possible future usage as 3D dosemeter in the medical area, as the area is lack of measure instrumentation for three dimension dose

  6. Estimation of absorbed and effective dose in {sup 18}F-FDG em PET- CT exams for diagnosis of lung cancer; Estimativa de dose absorvida e efetiva em exames de {sup 18}F-FDG em PET- CT para diagnostico de cancer de pulmao

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, Guilherme Neto de Pinho; Santana, Priscila do Carmo, E-mail: guinpc1@ufmg.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Departamento de Anatomia e Imagem; Oliveira, Paulo Marcio Campos de; Reis, Lucas Paixao dos [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2015-04-15

    This paper presents an evaluation of tissues and organs absorbed doses as well as the effective dose resulting from PET-CT scans performed with {sup 18}F-FDG radiopharmaceutical for lung cancer diagnosis in whole body scans. The ICRP-106 biokinetic model was used to estimate the absorbed and effective doses from the radiopharmaceutical for both male and female patient according to the characteristics of anthropomorphic Alderson Rando® simulators. Computer Tomography doses were evaluated using thermoluminescent detectors inserted in the same anthropomorphic simulators. Optimization protocols for image acquisition and the use of automatic exposure control were used in order to reduce patient doses, taking into account the equipment model and its system. The effective dose in female patients was 5.8 mSv. The effective dose in male patients was 8.4 mSv. The dose values estimated for the {sup 18}F-FDG PET-CT scan are below the values described in the literature. This is because the CT was not used for diagnostic but for morphological mapping. (author)

  7. Dose calculations for a simplified Mammosite system with the Monte Carlo Penelope and MCNPX simulation codes; Calculos de dosis para un sistema Mammosite simplificado con los codigos de simulacion Monte Carlo PENELOPE y MCNPX

    Energy Technology Data Exchange (ETDEWEB)

    Rojas C, E.L.; Varon T, C.F.; Pedraza N, R. [ININ, 52750 La Marquesa, Estado de Mexico (Mexico)]. e-mail: elrc@nuclear.inin.mx

    2007-07-01

    The treatment of the breast cancer at early stages is of vital importance. For that, most of the investigations are dedicated to the early detection of the suffering and their treatment. As investigation consequence and clinical practice, in 2002 it was developed in U.S.A. an irradiation system of high dose rate known as Mammosite. In this work we carry out dose calculations for a simplified Mammosite system with the Monte Carlo Penelope simulation code and MCNPX, varying the concentration of the contrast material that it is used in the one. (Author)

  8. Verification of the calculation program for brachytherapy planning system of high dose rate (PLATO); Programa de verificacion del calculo para un sistema de planificacion de braquiterapia de alta tasa de dosis (PLATO)

    Energy Technology Data Exchange (ETDEWEB)

    Almansa, J.; Alaman, C.; Perez-Alija, J.; Herrero, C.; Real, R. del; Ososrio, J. L.

    2011-07-01

    In our treatments are performed brachytherapy high dose rate since 2007. The procedures performed include gynecological intracavitary treatment and interstitial. The treatments are performed with a source of Ir-192 activity between 5 and 10 Ci such that small variations in treatment times can cause damage to the patient. In addition the Royal Decree 1566/1998 on Quality Criteria in radiotherapy establishes the need to verify the monitor units or treatment time in radiotherapy and brachytherapy. All this justifies the existence of a redundant system for brachytherapy dose calculation that can reveal any abnormality is present.

  9. The ferrous ammonium sulfate solid system, as dosemeter for processes at low temperatures and high doses of gamma radiation; El sistema sulfato ferroso amoniacal solido, como dosimetro para procesos a bajas temperaturas y altas dosis de radiacion gamma

    Energy Technology Data Exchange (ETDEWEB)

    Juarez C, J.M.; Ramos B, S.; Negron M, A. [ICN-UNAM, 04510 Mexico D.F. (Mexico)

    2005-07-01

    This paper presents the results obtained from a study of the radiation induced oxidation of crystalline ferrous ammonium sulfate with gamma rays at 295 K, 263 K and 77 K and dose from 0 to 300 kGy. The radiation induced decomposition of ferrous ammonium sulfate has been studied by the dissolution of the irradiated salt in 0,8 N sulfuric acid. The main product is Fe{sup 3+} and molar concentration of ferric ion was determined spectrophotometrically in the UV region at 304 nm. The optical density values showed a linear dependence with dose, indicating that the data obtained might be used to create a calibrating curve. Color in irradiated salt changes from blue to green, yellow and orange according to the absorbed dose. The accuracy and the reproducibility of the system were tested. In addition, some other characteristics make possible the use of this system as a dosimeter, similar to Fricke chemical dosemeter, at low temperatures and high dose. (Author)

  10. Determination of the conversion coefficient for ambient dose equivalent, H(10), from air kerma measurements; Determinacion del coeficiente de conversion para la dosis equivalente ambiental, H*(10), a partir de mediciones de kerma en aire

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez J, F. [UNAM, Facultad de Ciencias, Circuito Exterior, Ciudad Universitaria, 04510 Ciudad de Mexico (Mexico); Alvarez R, J. T., E-mail: trinidad.alvarez@inin.gob.mx [ININ, Departamento de Metrologia de Radiaciones Ionizantes, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2015-09-15

    Namely the operational magnitudes can be determined by the product of a conversion coefficient by exposure air kerma or fluence, etc. In particular in Mexico for the first time is determined the conversion coefficient (Cc) for operational magnitude Environmental Dose Equivalent H(10) by thermoluminescence dosimetry (TLD) technique. First 30 TLD-100 dosimeters are calibrated in terms of air kerma, then these dosimeters are irradiated inside a sphere ICRU type of PMMA and with the aid of theory cavity the absorbed dose in PMMA is determined at a depth of 10 mm within the sphere D{sub PMMA}(10), subsequently absorbed dose to ICRU tissue is corrected and the dose equivalent H(10) is determined. The Cc is determined as the ratio of H(10)/K{sub a} obtaining a value of 1.20 Sv Gy{sup -1} with a u{sub c}= 3.66%, this being consistent with the published value in ISO-4037-3 of 1.20 Sv Gy{sup -1} with a u{sub c}= 2%. (Author)

  11. Use of Monte Carlo simulation software for the calculation of the effective dose in cone beam Tomography; Uso del software de simulacion Monte Carlo para el calculo de la dosis efectiva en Tomografia de haz conico

    Energy Technology Data Exchange (ETDEWEB)

    Gomes B, W. O., E-mail: wilsonottobatista@gmail.com [Instituto Federal da Bahia, Rua Emidio dos Santos s/n, Bardalho, 40301-015 Salvador, Bahia (Brazil)

    2015-10-15

    Full text: In this study irradiation geometry applicable to PCXMC and the consequent calculation of effective dose in applications of cone beam computed tomography (CBCT) was developed. Two different CBCT equipment s for dental applications were evaluated: Care Stream Cs-9000 3-Dimensional and Gendex GXCB-500 tomographs. Each protocol initially was characterized by measuring the surface kerma input and the product air kerma-area, P{sub KA}. Then, technical parameters of each of the predetermined protocols and geometric conditions in the PCXMC software were introduced to obtain the values of effective dose. The calculated effective dose is within the range of 9.0 to 15.7 μSv for Cs 9000 3-D and in the range 44.5 to 89 mSv for GXCB-500 equipment. These values were compared with dosimetric results obtained using thermoluminescent dosimeters implanted in anthropomorphic mannequin and were considered consistent. The effective dose results are very sensitive to the radiation geometry (beam position); this represents a factor of fragility software usage, but on the other hand, turns out to be a very useful tool for quick conclusions regarding the optimization process of protocols. We can conclude that the use of Monte Carlo simulation software PCXMC is useful in the evaluation of test protocols of CBCT in dental applications. (Author)

  12. Mejora en los calendarios de cultivo para agricultura de secano en ceja de selva

    Directory of Open Access Journals (Sweden)

    Enrique Meseth

    2014-01-01

    Full Text Available Estetrabajo tuvocomo objetivo mejorar el manejo del agua para la agricultura en Vilcabambay similaresregiones en la ceja de selva, mediante eficientes calendarios de cultivo que permitan satisfacer las necesidadesde agua utilizando agricultura de secano, a fin de maximizar el rendimiento de los cultivos. Para ello se llevó acabo dos estudios de campo durante la temporada seca en septiembre de 2012 y la temporada de lluvias enfebrero de 2013 para medir el caudal de ríos y canales; asimismo se analizaron 19 muestras del suelo,presentando texturas franco y franco arenoso. Se utilizó datos delclima, cultivos y suelo para calcular lasnecesidades de agua en los cultivos y las necesidades de riego con el programa Cropwat, indicando que laevapotranspiración de cultivos es baja debido a la humedad y temperatura fría. Los cultivos no requieren riegodurante la temporada de lluvias, dediciembre aabril, sin embargo durante la temporada seca existennecesidades de riego, con una capacidad de flujo máximo de 1,72 l s-1en mayo. La capacidad de flujo puedeser satisfecha por riachuelos y manantiales con caudales de 2 a 6 l s-1en la misma temporada. Los resultadosde la investigación indican que es posible practicar la agricultura de secano, regando la tierra antes de lasiembra para que el rendimiento de los cultivos no sea afectado, caso contrario algunas cosechas comoverduras y papas se reducirían en un 4,7% y 1,4% respectivamente. Para minimizar estos efectos, se sugieresembrar ambos cultivos un mes más tarde de lo acostumbrado, adaptando su periodo de crecimiento a latemporada de lluvias.

  13. La teoría de conjuntos difusos como una opción para medir la pobreza. El caso de México

    Directory of Open Access Journals (Sweden)

    Marco Antonio Morales-Ramos

    2008-01-01

    Full Text Available El principal propósito de este artículo es presentar la teoría de conjuntos difusos como un instrumento confiable y preciso para medir pobreza, que además ofrece ventajas comparativas respecto a los métodos tradicionalmente empleados para esta tarea. Este artículo también muestra que la metodología de conjuntos difusos es compatible con la información censal (información agrupada para calcular índices de pobreza. Se presentan los resultados de medir la pobreza para los niveles estatal, municipal y localidad, y se comparan con resultados oficiales. Esta comparación revela que la teoría difusa resuelve algunos de los problemas metodológicos que enfrentan las líneas de pobreza y los índices de marginación, lo que hace de este instrumento una opción útil no solo para medir, sino también para aplicar y evaluar la política pública encaminada a combatir la pobreza.

  14. Deformaciones en el hormigón por fluencia para un estado tensional discontinuo con el tiempo

    Directory of Open Access Journals (Sweden)

    Rosso Ródenas, José Ramón

    1980-08-01

    Full Text Available Public Works Technical Engineer The overlap principle admitted in the CEB-FIP 1970 Recommendations and in the EH-68 is not valid for deformation formulae due to creep, of the present instructions EH-73 and EP-77, and it represents a serious setback when designing a structure when loads are acting that have a discontinuous way in time. The purpose of this article is to arbitrate a method that will enable us to calculate a creep curve for an intermediary discharge that fulfils the overlap principle, admitting the load creep curve and the deferred elastic deformation one for total compliance with the EH-73 and EP-77.

    El principio de superposición admitido en las Recomendaciones del CEB-FIP de 1970 y en la EH-68 no es válido para las fórmulas de deformaciones por fluencia de las actuales Instrucciones EH-73 y EP-77, por lo que constituye un grave inconveniente para proyectar una estructura cuando actúan cargas de una manera discontinua con el tiempo. El objeto de este artículo es el de arbitrar un método que nos permita calcular una curva de fluencia para una descarga intermedia que cumpla con el principio de superposición, admitiendo como ciertas la curva de fluencia de carga y la de deformación elástica diferida para descarga total de las EH-73 y EP-77.

  15. DIMENSIONAMENTO DA PRODUÇÃO ENERGÉTICA DE UM COLETOR SOLAR PLANO PARA AQUECIMENTO DE ÁGUA

    Directory of Open Access Journals (Sweden)

    Tiago Sinigaglia

    2016-12-01

    Full Text Available A radiação solar na forma de energia térmica pode ser utilizada para aquecer água e em diversas outras atividades. Um sistema de aquecimento solar é composto por um coletor solar, um reservatório térmico, circuito hidráulico e ainda pode ter uma fonte de energia auxiliar. Este trabalho tem por objetivo calcular a produção energética de uma placa coletora solar para atender a demanda de água quente utilizada na higienização de ordenhadeiras de uma propriedade rural de Tuparendi, RS. Com a utilização da energia térmica solar pode se diminuir o consumo de energia elétrica, contribuindo para a sustentabilidade do planeta e da atividade leiteira que possui uma margem de lucro não tão expressiva. A produção energética da placa coletora foi calculada pela metodologia F-chart e assim foi encontrada no mercado a placa coletora que produziu as melhores frações solares para a necessidade. Conclui-se que em alguns meses do ano a energia útil disponível  será menor que a demanda energética, necessitando assim de uma fonte de energia auxiliar.

  16. Dose and dose rate monitor

    International Nuclear Information System (INIS)

    Novakova, O.; Ryba, J.; Slezak, V.; Svobodova, B.; Viererbl, L.

    1984-10-01

    The methods are discussea of measuring dose rate or dose using a scintillation counte. A plastic scintillator based on polystyrene with PBD and POPOP activators and coated with ZnS(Ag) was chosen for the projected monitor. The scintillators were cylindrical and spherical in shape and of different sizes; black polypropylene tubes were chosen as the best case for the probs. For the counter with different plastic scintillators, the statistical error 2σ for natural background was determined. For determining the suitable thickness of the ZnS(Ag) layer the energy dependence of the counter was measured. Radioisotopes 137 Cs, 241 Am and 109 Cd were chosen as radiation sources. The best suited ZnS(Ag) thickness was found to be 0.5 μm. Experiments were carried out to determine the directional dependence of the detector response and the signal to noise ratio. The temperature dependence of the detector response and its compensation were studied, as were the time stability and fatigue manifestations of the photomultiplier. The design of a laboratory prototype of a dose rate and dose monitor is described. Block diagrams are given of the various functional parts of the instrument. The designed instrument is easiiy portable, battery powered, measures dose rates from natural background in the range of five orders, i.e., 10 -2 to 10 3 nGy/s, and allows to determine a dose of up to 10 mGy. Accouracy of measurement in the energy range of 50 keV to 1 MeV is better than +-20%. (E.S.)

  17. HidroEsta, software para cálculos hidrológicos

    Directory of Open Access Journals (Sweden)

    Máximo Villón Béjar

    Full Text Available Este trabajo de investigación se orientó a la elaboración de una herramientacomputacional bajo el título HidroEsta, software para cálculos hidrológicos,utilizando Visual Basic, el cual pretende ser una aplicación que permita facilitar y simplificar los cálculos laboriosos que se deben realizar en los estudios hidrológicos. El software permite el cálculo de los parámetros estadísticos, cálculos de regresión lineal, no lineal, simple y múltiple, así como regresión polinomial, evaluar si una serie de datos se ajustan a una serie de distribuciones, calcular a partir de la curva de variación estacional o la curva de duración, eventos de diseño con determinada probabilidad de ocurrencia, realizar el análisis de una tormenta y calcular intensidades máximas, a partir de datos de pluviogramas, los cálculos de aforos realizados con correntómetros o molinetes, el cálculo de caudalesmáximos, con métodos empíricos y estadísticos, cálculos de la evapotranspiración y cálculo del balance hídrico. En la investigación se probaron diferentes métodos numéricos para la solución de las ecuaciones, seleccionándose el más adecuado para cada situación. El producto del trabajo proporciona al ingeniero civil, agrícola, agrónomo, hidrólogos y otros especialistas que trabajen en este campo, una herramienta que permite realizar cálculos, simulaciones rápidas, y determinar los caudales o precipitaciones de diseño.

  18. Evaluation of the use of a Business Intelligence system for management of patient radiation dose undergone to nuclear medicine exams; Avaliação do uso de um sistema de Business Intelligence para gerenciamento da dose de pacientes submetidos a exames de medicina nuclear

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, A.C.F.S.; Capaverde, A.S.; Moreira, M.N.; Moraes, A.L.; Andrade, J.R.M.; Bacelar, A., E-mail: acfischer@hcpa.edu.br [Hospital de Clínicas de Porto Alegre (HCPA), RS (Brazil). Serviço de Física Médica e Radioproteção

    2017-07-01

    The feasibility of using a Business Intelligence (BI) system, IMPAX BI (Agfa), to manage the effective radiation dose of patients undergoing Nuclear Medicine exams was evaluated. The evaluation was divided into four stages, using retrospective data from the activity administered to adult patients in the year 2016. It was possible with the system to create panels to filter the data by date and display them in table and / or graphs, indicating the estimated doses and established limits. The IMPAX BI system proved to be a tool capable of assisting in dose management in Nuclear Medicine since it facilitates the identification of cases in which the patient is submitted to doses higher than those defined in the protocols of exams.

  19. EPR response of sucrose and microcrystalline cellulose to measure high doses of gamma radiation; Respuesta EPR de sacarosa y celulosa micro cristalina para medir altas dosis de radiacion gamma

    Energy Technology Data Exchange (ETDEWEB)

    Torijano, E.; Cruz, L.; Gutierrez, G.; Azorin, J.; Aguirre, F. [Universidad Autonoma Metropolitana, Unidad Iztapalapa, Av. San Rafael Atlixco 186, Col. Vicentina, 09340 Mexico D. F. (Mexico); Cruz Z, E., E-mail: eftc@xanum.uam.mx [UNAM, Instituto de Ciencias Nucleares, Circuito Exterior, Ciudad Universitaria, 04510 Mexico D. F. (Mexico)

    2015-10-15

    Solid dosimeters of sucrose and microcrystalline cellulose (Avicel Ph-102) were prepared, following the same process, in order to compare their EPR response against that of the l-alanine dosimeters considered as reference. All lots of dosimeters were irradiated with gamma radiation in Gamma beam irradiator with 8 kGy/h of the Nuclear Sciences Institute of UNAM. Doses ranged from 1 to 10 kGy respectively. We found that both the response of sucrose as microcrystalline cellulose were linear; however, the response intensity was, on average, twenty times more for sucrose. Comparing this against the EPR response of l-alanine in the range of doses, it was found that the response to sucrose is a third part; and microcrystalline cellulose is a sixtieth, approximately. The results agree with those found in the literature for sucrose, leaving open the possibility of investigating other dosage ranges for cellulose. (Author)

  20. Didactic revision of the operative magnitudes system ICRU for the evaluation of the equivalent dose in radiation external fields; Revision didactica del sistema de magnitudes operativas ICRU para la evaluacion de la dosis equivalente en campos externos de radiacion

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez R, J. T., E-mail: trinidad.alvarez@inin.gob.mx [ININ, Departamento de Metrologia de Radiaciones Ionizantes, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2014-10-15

    In this work is presented in a didactic way the operative magnitudes system ICRU, showing as these magnitudes carry out an appropriate estimate of the effective equivalent doses H{sub E} and the effective dose. The objective is to present the basic concepts of the dosimetry for radiation external fields with purposes of radiological protection, because the assimilation lack and technological development of this dosimetric magnitudes system has persisted for near 50 years, in terms of practice of the radiological protection in Mexico. Also, this system is an essential part of safety basic standards of the IAEA and ICRP recommendations 26, 60, 74 and 103, as well as of the ICRU 25, 39, 43, 51 and 57. (Author)

  1. Proposal for the classification of closed indoor spaces according to concentration of {sup 222}Rn and the possible doses involved; Propuesta para la clasificacion de los espacios interiores cerrados por su concentracion de Rn-222 y las posibles dosis involucradas

    Energy Technology Data Exchange (ETDEWEB)

    Espinoza, Marco; Leon, Kety; Martinez, Jorge [Direccion de Servicios, Instituto Peruano de Energia Nuclear, Lima (Peru)

    2014-07-01

    Radon causes more than 50 % of total dose from natural background radiation per year. It is widely demonstrated the capacity of radon to induce lung cancer in people exposed to this radioactive gas for long periods. Radon emerges continuously from materials that constitute soils, building materials and minerals present in our natural environment, all over the world. In our country, it is necessary to get better regulations to control the exposition of people to this gas inside buildings, dwellings and facilities where people spend their time. Our country has very simple and scarce regulations on this respect. At present, national regulations about radon are adaptations of recommendations and guides published for international organizations but without national studies or statistics to give realistic support to those rules. This work propose a classification for closed spaces where people live and work in this country taking into consideration their {sup 222}Rn concentration and probable doses involved. (authors).

  2. Mobilização corporal para prevenção de úlceras por pressão: custo direto com pessoal

    OpenAIRE

    Lima,Antônio Fernandes Costa; Castilho,Valéria

    2015-01-01

    RESUMOObjetivo:calcular o custo total médio (CTM) relativo à mão de obra direta (MOD) de profissionais de enfermagem para a mobilização corporal de pacientes visando à prevenção de úlceras por pressão.Método:estudo de caso quantitativo, exploratório-descritivo. Observou-se a realização de 656 mobilizações preventivas e calculou-se o custo multiplicando-se o tempo despendido pelos profissionais pelo custo unitário da MOD.Resultados:o CTM com MOD por Unidade correspondeu a: Clínica Médica R$ 5,...

  3. Determination of conversion factors of kerma and fluence to ambient dose equivalent for X-rays generated between 50 kV{sub p} to 125 kV{sub p}; Determinacao dos fatores de conversao de kerma no ar e de fluencia para o equivalente de dose ambiental para raios-X gerados no intervalo de 50 kV{sub p} a 125 kV{sub p}

    Energy Technology Data Exchange (ETDEWEB)

    Nogueira, Maria do Socorro

    1997-12-31

    The ambient dose equivalent was determined experimentally on the interval of energy of X ray applied in diagnostic radiology. A PMMA sphere was used to simulate the trunk human (phantom), based on the definition of the report ICRU 39. The absorbed dose in different positions in the phantom was determined using LiF-TLD 100. The X ray spectra were measured with a high-purity germanium detector (HP Ge). It was also determined the HVL and the effective energy in this energy range. The conversion coefficient of the K{sub air} and {Phi} to H{sup *}(d) were determined to 10, 50 and 60 mm deep in the PMMA sphere. The obtained values were compared with data of the literature. The maximum uncertainty obtained for the coefficients was 7.2%. All parameters were also determined to the X ray quality of the incident and transmitted beam by the patient, according to the recommendation of the standard DIN 6872. The conversion factor was calculated for those situations where the X-ray beam is transmitted by a layer and Pb and it is necessary to estimate the effective dose, as in the case of shielding project of radiology diagnosis room. (author) 51 refs., 35 figs., 15 tabs.

  4. Determination of conversion factors of kerma and fluence to ambient dose equivalent for X-rays generated between 50 kV{sub p} to 125 kV{sub p}; Determinacao dos fatores de conversao de kerma no ar e de fluencia para o equivalente de dose ambiental para raios-X gerados no intervalo de 50 kV{sub p} a 125 kV{sub p}

    Energy Technology Data Exchange (ETDEWEB)

    Nogueira, Maria do Socorro

    1998-12-31

    The ambient dose equivalent was determined experimentally on the interval of energy of X ray applied in diagnostic radiology. A PMMA sphere was used to simulate the trunk human (phantom), based on the definition of the report ICRU 39. The absorbed dose in different positions in the phantom was determined using LiF-TLD 100. The X ray spectra were measured with a high-purity germanium detector (HP Ge). It was also determined the HVL and the effective energy in this energy range. The conversion coefficient of the K{sub air} and {Phi} to H{sup *}(d) were determined to 10, 50 and 60 mm deep in the PMMA sphere. The obtained values were compared with data of the literature. The maximum uncertainty obtained for the coefficients was 7.2%. All parameters were also determined to the X ray quality of the incident and transmitted beam by the patient, according to the recommendation of the standard DIN 6872. The conversion factor was calculated for those situations where the X-ray beam is transmitted by a layer and Pb and it is necessary to estimate the effective dose, as in the case of shielding project of radiology diagnosis room. (author) 51 refs., 35 figs., 15 tabs.

  5. Dose rate constants for new dose quantities

    International Nuclear Information System (INIS)

    Tschurlovits, M.; Daverda, G.; Leitner, A.

    1992-01-01

    Conceptual changes and new quantities made is necessary to reassess dose rate quantities. Calculations of the dose rate constant were done for air kerma, ambient dose equivalent and directional dose equivalent. The number of radionuclides is more than 200. The threshold energy is selected as 20 keV for the dose equivalent constants. The dose rate constant for the photon equivalent dose as used mainly in German speaking countries as a temporary quantity is also included. (Author)

  6. Doses de composto orgânico comercial na composição de substratos para a produção de mudas de maracujazeiro em diferentes tipos de cultivo protegido

    OpenAIRE

    Costa,Edilson; Leal,Paulo A. M.; Sassaqui,Adriano R.; Gomes,Viviane do A.

    2010-01-01

    Doses de composto orgânico comercial misturado ao solo foram utilizadas como substrato na produção de mudas de maracujazeiro amarelo. O experimento foi conduzido no Campus de Aquidauana, da Universidade Estadual de Mato Grosso do Sul, de setembro a dezembro de 2007. Utilizaram-se seis ambientes protegidos: estufa plástica com pé-direito de 2,5m; viveiro telado com Sombrite® 50%, com pé-direito de 2,5m; viveiro telado de tela termo-refletora Aluminet® 50%, com pé-direito de 2,5m; viveiro cober...

  7. Una Medicion de la Pobreza: Un Enfoque Complementario para el Caso Colombiano

    Directory of Open Access Journals (Sweden)

    Sinisterra Paz Gullermo A.

    2003-08-01

    Full Text Available

    Sinisterra Paz, Guillermo A. " Una Medicion de la Pobreza: Un Enfoque Complementario para el Caso Colombiano" , Cuadernos de Economia, V. XXII , n. 38, Bogotá, 2003, paginas 127 - 150.

    En la literatura sobre la pobreza es cada vez mas aceptada la perspectiva sociologica de privaciones relativas, entendida como los los sentimientos de frustacion que tienen las personas al interior de la sociedad, al no tener acceso a las oportunidades que si son viables para otros. A partir de esto se han estructurado varios modelos que buscan medir dicha definicion de pobreza desde el punto de vista de la teoria economica. Se busca dar una vision complementaria a la forma de calcular la pobreza en Colombia, ultilizando el concepto de privaciones relativas, que es mucho mas rico en informacion que los conceptos normalmente utilizados, esto permite diagnosticar mejor quienes son pobres y quienes no lo son. Ademas, son aproximacimaciones que han sido tomadas por lo general en los paises desarrollados. Se utilizo una aproximacion econometrica a la definicion de la pobreza basada en tecnicas de analisis de secciones  transversales.

  8. para palmito

    Directory of Open Access Journals (Sweden)

    Francisco Paulo Chaimsohn

    2007-01-01

    Full Text Available Densidades de siembra, arreglos espaciales y fertilización en pejibaye (Bactris gasipaes cv Diamantes-10 para palmito. La investigación se llevó a cabo en la Estación Experimental Los Diamantes (Guápiles, Costa Rica, el 3 de octubre del 2003, cuyo objetivo fue la evaluación del efecto de diferentes densidades de siembra (3.333, 5.000 y 6.666 plantas/ha, arreglos espaciales, y diversos métodos de fertilización (química, orgánica, sobre el crecimiento de las plantas de pejibaye para producción de palmito. Se consideraron las variables diámetro y altura del tallo primario y el número de hojas y rebrotes como indicadores de producción. El período de evolución abarcó sólo los primeros 25 meses de crecimiento en el campo. El número de hojas, la altura y el diámetro del tallo no mostraron diferencias de respuesta relevantes. Sólo el número de rebrotes disminuyó al aumentar la densidad de la población, cuando se midió a los 15 meses de edad. El efecto de la fertilización se hizo evidente después de la primera cosecha, realizada a los 20 meses, debido al aumento de la competencia entre plantas, ahora más desarrolladas. Fue entonces cuando la fertilización química indujo la producción de un mayor número y vigor de los rebrotes. Sin embargo, las prácticas evaluadas 25 meses después de la siembra, no habían infl uido hasta ese momento en el número de palmitos cosechados, ni tampoco había afectado las características físicas de los sectores foliar y caulinar del palmito.

  9. Analysis of FT-IR for dosimetric characterization of poly(vinylidene fluoride - hexafluoropropylene) irradiated with high doses of gamma radiation; Analise de FT-IR para caracterizacao dosimetrica do poli(fluoreto de vinilideno - hexafluorpropileno) irradiado com altas doses de radiacao gama

    Energy Technology Data Exchange (ETDEWEB)

    Liz, Otavio Souza Rocha; Medeiros, Adriana de Souza [Universidade Federal de Minas Gerais (DEN/UFMG), Belo Horizonte, MG (Brazil). Dept. de Engenharia Nuclear; Faria, Luiz Oliveira de, E-mail: farialo@cdtn.b [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2011-10-26

    Polymeric materials when exposed to ionizing radiation undergo changes such as the crosslinking and chain oxidation. Recently, the optical absorption intensities in the ultraviolet visible region (273 nm) due to radio- induction of conjugated C=C bonds in P(VDF-TrFE) copolymers has been successfully used for high dose dosimetry purposes in gamma fields ranging from 0.1 to 200 kGy. In this context, the interest of performing a systematic investigation on another fluorinated copolymer of PVDF, the (Polyvinylidene fluoride - hexa fluoro propylene) [P(VDF- HFP)] has come to light, not only for UV-VIS range but also for the near and medium infrared ranges. In this investigation FTIR and UV-Vis spectra, acquired before and after irradiation, were used to investigate the relationship between optical absorbance and delivered gamma doses ranging from 100 to 3,000 kGy. The results indicate that the absorption band at 1729 cm-1, originated by the chain oxidation through the radioinduction of C=O bonds, presents an unambiguous behavior with the delivered gamma doses in a very large extension, ranging from 0 to 1,000 kGy. This results lead to conclude that P(VDF-HFP) copolymer shows excellent dosimetric properties which make it able to be investigated as a high dose dosimeter

  10. Un modelo de programación binaria mixta para el problema generalizado de la p-centdiana

    Directory of Open Access Journals (Sweden)

    Marisa Martinez

    2002-01-01

    Full Text Available Los problemas de localización tratan de averiguar la ubicación de las instalaciones de una empresa de modo que se minimicen los costes o se maximicen los beneficios. Dos de los modelos más utilizados en localización en redes son el problema de la p-mediana y el problema del p-centro. El primero consiste en minimizar la suma total de las distancias ponderadas, mientras que el segundo trata de minimizar la máxima distancia ponderada desde un centro de servicio hasta sus usuarios asignados. El objetivo del problema de la p-mediana hace que sea eficiente pero no equitativo, mientras que la cota implícita en el problema del p-centro lo convierte en equitativo pero no eficiente. Para combinar ambos aspectos, aparece en la década de los 70 un nuevo problema, el de la p-centdiana, cuya función objetivo es una mezcla de las dos anteriores. En este trabajo presentamos un modelo de programación binaria mixta para el problema generalizado de la p-centdiana sobre una red en el que los pesos asociados al p-centro y a la p-mediana no son necesariamente iguales. El primer paso para resolver el problema es identificar su conjunto dominante finito. En consecuencia, previamente a la descripción del modelo, proponemos un algoritmo que nos permitirá calcular este conjunto.

  11. Contenção farmacológica do gato-do-mato-pequeno, Leopardus tigrinus, para colheita de sêmen, pela associação de tiletamina zolazepam e xilazina Chemical restraint of tigrinas, Leopardus tigrinus, for semen collection with allometrically scaled doses of tiletamine, zolazepam, and xylazine

    Directory of Open Access Journals (Sweden)

    Julio C. Juvenal

    2008-11-01

    Full Text Available Foram avaliados os efeitos anestésicos da associação de cloridrato de tiletamina, cloridrato de zolazepam e cloridrato de xilazina para contenção farmacológica de gatos-do-mato-pequenos, Leopardus tigrinus Schreber, 1775 (Felidae, submetidos à colheita de sêmen por eletroejaculação. Formularam-se três diferentes protocolos, sendo as doses calculadas individualmente, por meio de extrapolação alométrica interespecífica, com base nas indicações posológicas usuais para o cão doméstico com massa de 10,0 kg. No Protocolo 1 (n=10 a base para o cálculo alométrico foi 5,0mg/kg para tiletamina + zolazepam e 0,5mg/kg para xilazina; no Protocolo 2 (n=12, foi 5,0mg/kg para tiletamina + zolazepam e 0,75mg/kg para xilazina; e no Protocolo 3 (n=11, foi 5,0mg/ kg para tiletamina + zolazepam e 1,0mg/kg para xilazina. Os animais foram anestesiados em três ocasiões, com intervalo mínimo de 30 dias. Após a administração dos fármacos, monitorizaram-se durante 120 minutos freqüência cardíaca, freqüência respiratória, temperatura retal, miorrelaxamento e nocicepção. Também foram avaliados período de latência, período anestésico hábil e contaminação do ejaculado por urina. De um total de 32 colheitas, houve contaminação por urina em 10 colheitas (31,2% e em 18 alíquotas (0,07%, as quais foram desprezadas, não inviabilizando a análise e o processamento do sêmen. Observou-se pequeno aumento da temperatura retal durante a eletroejaculação, justificado pela contração muscular, ocorrendo redução da temperatura após o procedimento. As freqüências cardíaca e respiratória oscilaram durante o experimento, porém se mantiveram dentro dos padrões fisiológicos para a espécie. Nos três protocolos analisados não houve diferença significativa de sensibilidade de membros torácicos entre momentos antes e durante a eletroejaculação (pe"0,10, caracterizando assim a eficácia dos protocolos em propiciar analgesia e

  12. Técnica para obtenção do aparelho geniturinário e dosagem do PSA (Prostate Specific Antigen no hamster sírio, Mesocricetus auratus Technique for collecting blood for PSA (Prostate Specific Antigen dosing and genitourinary system obtaining in syrian hamster, Mesocricetus auratus

    Directory of Open Access Journals (Sweden)

    Dimas José Araújo Vidigal

    2004-12-01

    ículas seminais e testículos. Observou-se nos Hamsters adultos (n=20, setenta por cento de alterações nos anexos sexuais a saber: um caso (5% de processo supurativo das vesículas seminais, um caso (5% de processo inflamatório isolado das vesículas seminais, um caso (5% de Processo inflamatório das vesículas seminais, HBP e prostatite concomitante e um caso (5% de infarto testicular e prostatite. Onze animais (55%, dos Hamsters adultos, apresentaram HBP (Hiperplasia Benigna da Próstata. Conclusão: A técnica cirúrgica descrita mostrou-se eficiente para a obtenção dos orgãos e estruturas do aparelho geniturinário, estudo histológico desses orgãos e dosagem do PSA no Hamster Sírio, Mesocricetus auratus.Purpose: To explain the available technique in collecting blood for PSA (Prostate Specific Antigen dosing and the genitourinary system extracting from Syrian Hamster, Mesocricetus auratus, and correspond PSA findings to anexed sexual histologic changes. Methods: Thirty (n=30 Hamsters were used in the experiment: ten (n=10 animals were on the average age of 47,5 days on the decease mourent, being qualified as young and twenty ( n=20 animals over the age of one year were qualified as adults. After being under chetamina cloridate and diazepam anesthesia, on the superior abdomen level, c. 1,5mL to 2,0mL of blood were collected for total PSA dosing though ELISA method, with human antigen. They died after blood extracting. After verifying the animal death, laparatomy was carried out, extracting in complete monoblock the genitourinary system for a histologic study of sexual anexes. A PSA correlation was set with the found histologic changes. Results: An excellent anesthesian plan was obtained after shooting chetamina cloridate and diazepam intraperitoneum on the animals, that made possible to collect blood through the cava vein trans-derm via to the superior abdomen for the PSA dosing. The animal died after blood collecting. Laparatomy was carried out with the complete

  13. Proposal of a postal system for Ir-192 sources calibration used in high dose rate brachytherapy with LiF:Mn:Ti thermoluminescent dosemeters; Proposta de um sistema postal para a calibracao de fontes de {sup 192} Ir, utilizadas em braquiterapia de alta taxa de dose, com dosimetros termoluminescentes de LiF: Mn: Ti

    Energy Technology Data Exchange (ETDEWEB)

    Vieira, W.S.; Borges, J.C.; Almeida, C.E.V. [Instituto de Radioprotecao e Dosimetria. CNEN Caixa Postal 37750, 22780-160, Rio de Janeiro (Brazil)

    1998-12-31

    A proposal in order to improve the brachytherapy quality control and to allow postal intercomparison of Ir-192 sources used in high dose rate brachytherapy has been presented. The LiF: Mn: Ti (TLD 100) detector has been selected for such purpose. The experimental array and the TLDs irradiation and calibration techniques, at the treatment units, have been specified in the light of more recent methodology of Ir-192 calibration sources. (Author)

  14. Calibration of photographic dosemeters to evaluate the personal equivalent dose, Hp (10), irradiated by different radiation qualities and angles of incidence; Calibracao de dosimetros fotograficos para avaliar o equivalente de dose pessoal, Hp(10), irradiados por diferentes qualidades de radiacao e angulos de incidencia

    Energy Technology Data Exchange (ETDEWEB)

    Santoro, Christiana; Antonio Filho, Joao, E-mail: chsantoro@gmail.com, E-mail: jaf@ufpe.br [Universidade Federal de Pernambuco (DEN/UFPE), Recife, PE (Brazil). Departamento de Energia Nuclear; Santos, Marcus Aurelio P.; Goncalves Filho, Luiz Carlos, E-mail: masantos@cnen.gov.br, E-mail: l.filho@cnen.gov.br [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, Pe (Brazil)

    2013-07-01

    To use radiation detectors, should periodically perform tests and calibrations on instruments in order to verify its good functionality. One way to ascertain the quality of the instrument is to conduct a study of the angular dependence of the response of the radiation detectors. The photographic dosimetry has been used widely to quantify the radiation doses and to estimate levels of doses received by workers involved with X-and gamma radiation. Photographic dosimeters are used because provide wide range of exposure and good accuracy. One of the sources of error have been introduced by different irradiation geometries between calibration and measurement in radiation fields used in x-ray and gamma ray sources, therefore, there is a need for an evaluation of the sensitivity of dosimeters with variation of the angle of the incident beam. In this study were tested 190 photographic dosemeters in the Metrology Laboratory of the Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE) using the phantom H{sub p} (10), where the dosimeters are evaluated on the basis of the new operational magnitude for individual monitoring, the equivalent personal dose, H{sub p} (10). Angular dependence of these radiation detectors was studied in X radiation fields (in the range of 45 keV energy to 164 keV) and gamma radiation ({sup 137}Cs-662 keV e {sup 60}Co - 1250 keV)

  15. Preparation and determination of kerma for Iridium 192 sources of low dose rate for brachytherapy; Preparacion y determinacion del kerma de fuentes de iridio-192 de baja tasa de dosis para braquiterapia

    Energy Technology Data Exchange (ETDEWEB)

    Tendilla, J.I.; Tovar M, V.; Mitsoura, E.; Aguilar H, F.; Alanis M, J. [Instituto Nacional de Investigaciones Nucleares, C.P. 52045-1, Salazar, Esrado de Mexico, D.F. (Mexico)

    2000-07-01

    The practice of Brachytherapy with Iridium-192 sources of low dose rate (0.4 - 0.8 Gy/h) is a technique used in the treatment of diverse illnesses. in this work the preparation, quality control and calibration are presented in terms of kerma in air of Iridium-192 using as target these recycled Iridium-Platinum wires. The targets were obtained as decayed sources of different radio therapeutical centers in the country and they were characterized by Scanning electron microscopy in order to determine their chemical composition. Subsequently it was developed an experimental design to establish the effect of neutron flux, geometrical array and irradiation time over the activity and percentage of the sources homogeneity. The homogeneity was determined by auto radiography and by Gamma spectroscopy. Once the optimal irradiation conditions were established, it is determined the apparent activity and kerma in air using a well type ionization chamber with traceability to a primary laboratory. Iridium-192 sources were obtained with an average homogeneity 96 %, apparent activity 282.129 {+-} 0.531 M Bq and kerma in air 0.03200 {+-} 0.00006 m Gy m/h A. (Author)

  16. Determination of absorbed dose in crystalline and thyroid gland with irradiation protocols applied in orthopantomography equipment for dental examination; Determinacion de dosis absorbida en cristalino y glandula tiroides con protocolos de irradiacion aplicados en equipos de ortopantomografia para panoramica dental

    Energy Technology Data Exchange (ETDEWEB)

    Munoz A, A. A.; Ramirez A, L. M. [Instituto Tecnologico Metropolitano, Grupo de Investigacion e Innovacion Biomedica, Medellin, Antioquia (Colombia); Sosa A, M. A.; Azorin V, J. C.; Vallejo H, M. A. [Universidad de Guanajuato, Departamento de Fisica, Loma del Bosque 103, Lomas del Campestre, 37150 Leon, Guanajuato (Mexico)

    2016-10-15

    Ionizing radiations are very useful in the medical field for the diagnostic use of different pathologies. Currently there are different technologies for diagnostic imaging using conventional X-ray, computed tomography, mammography, angiography, dental panoramic X-ray, among others. However, it should be noted that exposure to radiation in this type of diagnostic tests has increased considerably in recent years, because radiological examinations are not always carried out according to the actual clinical needs of each patient, increasing the risk to develop cancer. In this paper, the absorbed dose in the lens and thyroid gland was measured with the help of TLD-100 dosimeters located in a PMMA phantom adapted for orthopantomography (dental panoramic X-ray) equipment in 5 hospitals; using the parameters pre-configured for normal adult for irradiation. A Harshaw 3500 equipment was used to read the dosimeters, obtaining a value of 1.324 ± Sd 0.01 mGy for crystalline and 1.044 ± Sd 0.03 mGy values which are intended to be validated under other conditions and protocols. (Author)

  17. Monte Carlo design of a system for the detection of explosive materials and analysis of the dose; Diseno Monte Carlo de un sistema para la deteccion de materiales explosivos y analisis de la dosis

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez A, P. L.; Medina C, D.; Rodriguez I, J. L.; Salas L, M. A.; Vega C, H. R., E-mail: pabloyae_2@hotmail.com [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas, Zac. (Mexico)

    2015-10-15

    The problems associated with insecurity and terrorism have forced to designing systems for detecting nuclear materials, drugs and explosives that are installed on roads, ports and airports. Organic materials are composed of C, H, O and N; similarly the explosive materials are manufactured which can be distinguished by the concentration of these elements. Its elemental composition, particularly the concentration of hydrogen and oxygen, allow distinguish them from other organic substances. When these materials are irradiated with neutrons nuclear reactions (n, γ) are produced, where the emitted photons are ready gamma rays whose energy is characteristic of each element and its abundance allows estimating their concentration. The aim of this study was designed using Monte Carlo methods a system with neutron source, gamma rays detector and moderator able to distinguish the presence of Rdx and urea. In design were used as moderators: paraffin, light water, polyethylene and graphite; as detectors were used HPGe and the NaI(Tl). The design that showed the best performance was the moderator of light water and HPGe, with a source of {sup 241}AmBe. For this design, the values of ambient dose equivalent around the system were calculated. (Author)

  18. CONVERGÊNCIA DOS MODELOS DE ÁRVORES BINOMIAIS PARA AVALIAÇÃO DE OPÇÕES

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    Tara Keshar Nanda Baidya

    2001-06-01

    Full Text Available Black & Scholes (1973 desenvolveram um modelo para a avaliação de opções de compra e venda do tipo Europeu. Merton (1973 estendeu o modelo para ações que pagam dividendos. Muitos outros desenvolvimentos foram feitos acerca dos dois trabalhos citados, mas talvez um dos mais importantes foi proposto por Cox, Ross & Rubinstein (1979, onde o processo estocástico (para o preço da ação objeto em tempo e estado contínuo (Movimento Geométrico Browniano proposto por Black & Scholes foi aproximado por um processo de tempo e estado discreto (Random Walk. O modelo de Cox, Ross & Rubinstein, hoje conhecido como Modelo Binomial, tornou-se um dos métodos mais utilizados para calcular o valor de opções, principalmente opções americanas, devido a sua simplicidade e fácil implementação computacional. Mas, o modelo binomial possui uma convergência fraca, em forma oscilatória, para o valor verdadeiro. Este artigo pretende mostrar as principais soluções encontradas na literatura para acelerar a convergência.Black & Scholes (1973 developed a model for pricing European call options on assets that do not pay dividends. Merton (1973 extended it to include assets that pay dividends. Many other developments have been made after that. Perhaps one of the most important work in this area was proposed by Cox, Ross & Rubinstein (1979, where the stochastic process for the price of the underlying asset proposed by Black & Scholes was approximated by a discrete time binomial process. The method proposed by Cox, Ross & Rubinstein became very popular because of its simplicity and easy implementation. But the convergence of the binomial model is weak and oscillatory. This work pretends to explain the main solutions found in the literature to accelerate convergence.

  19. Carriles para alta velocidad. Comportamiento en fatiga

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    Duart, J. M.

    2005-02-01

    -aire inducido. Los ensayos de fatiga de los carriles soldados se llevan a cabo por flexión en cuatro puntos en concordancia con la norma europea. El método Locati, descrito en esta nota, está basado en la Ley de Miner de daño acumulado y en las curvas de Wohler del material ensayado. Permite calcular, con precisión suficiente, las tensiones límites de fatiga al 50%. Así, los valores obtenidos, en ensayos a dos millones de ciclos, para carriles sin soldar (Sf = 353 MPa, carriles soldados con precalentamiento de oxipropano (Sf = 225 MPa y carriles soldados con precalentamiento de propano-aire inducido (Sf = 210 MPa son muy similares y aceptables a los estipulados por los métodos de determinación del límite de fatiga según norma europea. Debido a la comodidad, rapidez y bajo coste del método Locati resulta, en nuestra opinión, muy adecuado para el control de calidad de los procesos de soldadura aluminotérmica en vigor, de carriles de alta resistencia.

  20. Método modificado de muestreo por conglomerados para la evaluación rápida de necesidades después de un desastre

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    Malilay J.

    1997-01-01

    Full Text Available El método de muestreo por conglomerados puede utilizarse para llevar a cabo la evaluación rápida de las necesidades de salud y de otro tipo en comunidades afectadas por desastres naturales. El método, que se basa en el modelo usado por el Programa Ampliado de Inmunización de la OMS para estimar la cobertura con vacunación, ha sido modificado para que proporcione 1 estimaciones de la población que queda en una zona determinada y 2 estimaciones del número de personas con necesidades específicas en la zona que ha sido afectada por un desastre. Este enfoque difiere del que se ha usado anteriormente a raíz de otros desastres en que las evaluaciones rápidas de las necesidades solo han consistido en estimar la proporción de la población con necesidades específicas. Aquí se propone un diseño de encuesta modificado que se basa en el uso de n x k para calcular la población restante, la gravedad del daño, la proporción y el número de personas con necesidades específicas, el número de domicilios dañados o destruidos y los cambios que sufren estas estimaciones en determinado período como parte de la encuesta.

  1. MODELO PARA EL PROCESO DE EXTRACCIÓN, TRANSFORMACIÓN Y CARGA EN BODEGAS DE DATOS. UNA APLICACIÓN CON DATOS AMBIENTALES

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    Néstor Darío Duque Méndez

    2016-01-01

    Full Text Available La administración de bodegas de datos o datawarehouse requiere de un procesamiento para garantizar la veracidad, integridad y centralización de los datos cuando existen diversas fuentes de información, haciendo necesario utilizar aplicativos especializados para la Extracción, Transformación y Carga de datos (ETL. Estos aplicativos presentan conflictos en su parametrización, carecen de la implementación de filtros de corrección adaptables a las características de los datos y pueden demandar altos costos para su implementación. En el presente artículo se plantea un modelo genérico que aplica las etapas de ETL y permite realizar seguimiento del proceso al mantener un registro histórico de errores filtrados y calcular indicadores para identificar la calidad en el procesamiento. La validación del modelo fue realizada sobre un caso de estudio con datos ambientales. El modelo demostró obtener resultados satisfactorios. Se plantea realizar más validaciones del modelo, en otros ámbitos, incluyendo nuevos tipos y estructuras de datos.

  2. Measurement of extrapolation curves for the secondary pattern of beta radiation Nr. 86 calibrated in rapidity of absorbed dose for tissue equivalent by the Physikalisch Technische Bundesanstalt; Medicion de curvas de extrapolacion para el patron secundario de radiacion beta Nr. 86 calibrado en rapidez de dosis absorbida para tejido equivalente por el Physikalisch Technische Bundesanstalt

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez R, J.T

    1988-10-15

    The following report has as objective to present the obtained results of measuring - with a camera of extrapolation of variable electrodes (CE) - the dose speed absorbed in equivalent fabric given by the group of sources of the secondary pattern of radiation Beta Nr. 86, (PSB), and to compare this results with those presented by the calibration certificates that accompany the PSB extended by the primary laboratory Physikalisch Technische Bundesanstalt, (PTB), of the R.F.A. as well as the uncertainties associated to the measure process. (Author)

  3. Baixas doses de melatonina exógena no diabetes experimental : implicações para a estrutura, função e defesa antioxidante do testículo e epidídimo de ratos = Low doses of exogen melatonin under experimental diabetes: implications for rat testicular and epididimal structure, function and antioxidant defense

    OpenAIRE

    Carolina Frandsen Pereira da Costa

    2014-01-01

    Resumo: Existem inúmeras evidências de que o diabetes afeta a função reprodutiva masculina, provocando danos aos parâmetros espermáticos, e portanto, influenciando a fertilidade dos indivíduos afetados. A melatonina é um hormônio secretado pela glândula pineal que apresenta uma extensa gama de atuações, dentre elas um papel fundamental no controle da esteroidogênese e na proteção contra radicais livres. O objetivo deste estudo foi avaliar se a melatonina oferecida oralmente, em baixas doses, ...

  4. Measurement of conversion coefficients between air Kerma and personal dose equivalent and backscatter factors for diagnostic X-ray beams; Determinacao experimental dos coeficientes de conversao de Kerma no ar para o equivalente de dose pessoal, Hp(d), e fatores de retroespalhamento em feixes de raios-x diagnostico

    Energy Technology Data Exchange (ETDEWEB)

    Rosado, Paulo Henrique Goncalves

    2008-07-01

    Two sets of quantities are import in radiological protection: the protection and operational quantities. Both sets can be related to basic physical quantities such as kerma through conversion coefficients. For diagnostic x-ray beams the conversion coefficients and backscatter factors have not been determined yet, those parameters are need for calibrating dosimeters that will be used to determine the personal dose equivalent or the entrance skin dose. Conversion coefficients between air kerma and personal dose equivalent and backscatter factors were experimentally determined for the diagnostic x-ray qualities RQR and RQA recommended by the International Electrotechnical Commission (IEC). The air kerma in the phantom and the mean energy of the spectrum were measured for such purpose. Harshaw LiF-100H thermoluminescent dosemeters (TLD) were used for measurements after being calibrated against an 180 cm{sup 3} Radcal Corporation ionization chamber traceable to a reference laboratory. A 300 mm x 300 mm x 150 mm polymethylmethacrylate (PMMA) slab phantom was used for deep-dose measurements. Tl dosemeters were placed in the central axis of the x-ray beam at 5, 10, 15, 25 and 35 mm depth in the phantom upstream the beam direction Another required parameter for determining the conversion coefficients from was the mean energy of the x-ray spectrum. The spectroscopy of x-ray beams was done with a CdTe semiconductor detector that was calibrated with {sup 133} Ba, {sup 241} Am and {sup 57} Co radiation sources. Measurements of the x-ray spectra were carried out for all RQR and RQA IEC qualities. Corrections due to the detector intrinsic efficiency, total energy absorption, escape fraction of the characteristic x-rays, Compton effect and attenuation in the detector were done aiming an the accurate determination of the mean energy. Measured x-ray spectra were corrected with the stripping method by using these response functions. The typical combined standard uncertainties of

  5. Pré-tratamento com água e doses de ácido indolbutírico para estaquia herbácea de pitangueiras Pre-treatments with water and indole butyric acid dosis for herbaceous cuttings of Surinam cherry

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    Daiane Silva Lattuada

    2011-12-01

    Full Text Available No Brasil, a maioria dos pomares de pitangueira (Eugenia uniflora é formada por mudas do tipo pé-franco, o que torna os plantios com baixa uniformidade genética. A propagação vegetativa via estaquia é uma alternativa viável para propagação de diversas espécies frutíferas, podendo ser utilizada também com as espécies nativas, proporcionando a formação de pomares homogêneos, com a produção de mudas com alta sanidade, além de antecipar a produção. Nesse contexto, conduziu-se um estudo visando à multiplicação vegetativa da pitangueira, em que se testou a estaquia herbácea a partir de estacas coletadas de plantas matrizes jovens e adultas, submetidas a três períodos de imersão em água (0, 24 ou 48 horas, além da aplicação de doses de ácido indolbutírico (0, 2000, 4000 e 6000mg L-1. Foram avaliadas a sobrevivência (%, a retenção e a emissão foliar (n° folhas/ estaca, a calogênese (% e enraizamento das estacas (%. Ao final do experimento, avaliou-se massa fresca e seca de parte aérea e raiz, número de folhas e área foliar. O delineamento experimental foi o completamente casualizado, com três repetições de dez plantas por tratamento para os parâmetros não destrutivos e três repetições de cinco plantas por tratamento para os parâmetros destrutivos. A estaquia herbácea foi eficiente para produzir mudas de pitangueira, especialmente quando utilizadas estacas oriundas de plantas jovens sem necessidade de pré-lavagem nem adição de auxinas exógenas.In Brazil, most of the Surinam cherry (Eugenia uniflora orchards is formed by ungrafted plants, which makes the plantations have low genetic uniformity. The vegetative minicutting propagation is a viable alternative for the propagation of several fruit species, and can also be used with native species providing the formation of orchards with homogeneous populations of plants, with production of seedlings with high health and accelerated propagation process

  6. Performance evaluation of the QC-6PLUS quality control system in terms of photons and electrons absorbed doses to water; Avaliacao do desempenho do sistema de controle da qualidade QC-6Plus em termos de dose absorvida na agua para fotons e eletrons

    Energy Technology Data Exchange (ETDEWEB)

    Teixeira, Flavia Cristina da Silva

    2004-06-15

    The quality of the treatment in radiotherapy depends on the necessary knowledge of the liberated dose in the tumor and of several other physical parameters and dosimetric that characterize the profile of the radiation field. Worrying about the reliability of some commercial equipment that aim at determining the main parameters of a radiation field in a practical way for daily checks in an institution with radiotherapy service, in this work a study of the performance of the quality assurance system, QC6-Plus manufactured by PTW-Freiburg for daily checks, was developed, in order to assure the use of this equipment with larger reliability level in the routine of quality assurance of the hospitals as well as to make possible its use in the Program of Regulatory Inspections of the Services of Radiotherapy of the Country accomplished by IRD/CNEN. The found results indicate that the system QC6-Plus is perfectly adapted and practical for relative measures of daily and weekly control of the main parameters of clinical beans in agreement with reference values recommended in TECDOC 1151. However for measurements of absolute dose it should not be used because, for beams of electrons the system does not present the necessary characteristics to execute this measure type in agreement with the reference protocol, TRS 398, and for photons of energy 15 MV presented a deviation in relation to the conventional method of absolute dosimetry of 7,7%, that it is a lot above the expected in agreement with TRS 398. (author)

  7. Application of low-dose gamma irradiation to extend the shelf life of minimally processed Red Beet (Beta vulgaris sp. vulgaris L.), cv. Early Wonder; Aplicacao de baixas doses de radiacao gama para extensao da vida util de beterraba vermelha (Beta vulgaris ssp. vulgaris L.), cv. Early Wonder, minimamente processada

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez, Nilber Kenup

    2006-07-01

    This study was aimed at investigating the effects of low-dose gamma irradiation on shelf-life extension and phyto sanitary safety of minimally processed red beet with basis on physicochemical; microbiological; chemical and sensory analyses. The samples (Beta vulgaris ssp. vulgaris L.), Early Wonder cultivar, were cultivated in the experimental area of the Horticulture Sector of the Departamento de Fitotecnia of the Instituto de Agronomia, Universidade Federal Rural do Rio de Janeiro, Seropedica, RJ, as part of two experiments performed during the second semester of 2005. In each experiment, 1200 plants (40 per linear meter of terrain) were sowed. Physicochemical analyses (fresh mass; length; average diameter and total soluble solids) of the edible part of the red beets (their tuberous roots) were periodically carried out in order to assess the most appropriate time for harvest by monitoring the development of the plants. Those times were found to be 104 and 73 days after transplanting, respectively. The harvested edible part of the roots were minimally processed and separated in two groups: (1) gamma irradiated (with doses of 0.5; 1.0 and 1.5 kGy) and (2) non-irradiated (control). All samples were stored at 8 degree C. Microbiological analyses were performed during the storage period (22 and 21 days, for experiments 1 and 2, respectively) in order to evaluate the phyto sanitary quality of the samples (Salmonella sp.; coliforms and total count of mesophilic aerobic and lactic acid bacteria). The samples irradiated with 1.0 and 1.5 kGy were found to remain appropriate for consumption for 21 days, as compared to only 7 days for the control. Monitoring of chemical composition was also performed and included the determination of saccharose; glucose; fructose and vitamins B1 and B2. No difference was found between the concentrations of those vitamins in irradiated and control samples at the end of the storage period, whereas significant changes in sugar contents were

  8. Fontes e doses de nitrogênio na adubaçâo química do cafeeiro I: latossolo roxo transição para latossolo vermelho-amarelo, orto Nitrogen fertilizers for coffee - I: red latosol transition to clay red yellow latosol

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    F. R. Pupo de Moraes

    1976-01-01

    Full Text Available Nitrocálcio, salitre-do-chile, sulfato de amônio e uréia, nas doses de 75, 150, 225 e 300 quilogramas de N por hectare, foram estudados comparativamente em um experimento de adubação química nitrogenada em café mundo novo, instalado em latossolo roxo transição para latossolo vermelho-amarelo, orto da região de Campinas, SP, em março de 1957, tendo sido efetuadas 11 colheitas de 1959 a 1969, inclusive. O nitrogênio foi aplicado parceladamente em 2, 4, 5 e 9 fracionamentos anuais durante a fase inicial do ensaio ou seja, até o ano agrícola 1963/64. A partir de então o esquema do parcelamento passou a 1, 2, 3 e 4 fracionamentos por ano. Após a colheita de 1969, os cafeeiros foram cortados a 50 cm do solo, efetuando-se em 1972 uma série de amostragens de solo e de folhas de cafeeiros, para a avaliação dos efeitos decorrentes da aplicação continuada das várias fontes de nitrogênio aplicadas. As produções de café obtidas durante todo o transcorrer do ensaio revelaram uma reação altamente significativa e positiva para as doses crescentes de nitrogênio. O Nitrocálcio e o sulfato de amônio foram as melhores fontes de nitrogênio, tendo diferido significativamente da uréia e do salitre-do-chile. O sulfato de amônio foi inicialmente superior ao Nitrocálcio sendo, entretanto, superado por este na parte final do experimento. Da colheita obtida no ano de 1961 foram separadas amostras de frutos provenientes das várias fontes de N estudadas, para determinação dos teores de macro e micronutrientes. Foram observadas diferenças no teor de N entre os tratamentos que receberam esse elemento e o controle não adubado. Foram observadas também diferenças nos teores de Fe e Mn nos frutos, entre as fontes de N utilizadas. No final do experimento foi observado um efeito acidificante sobre o solo, em decorrência do emprego do sulfato de amônio, da uréia e do Nitrocálcio. Observou-se aumento significativo nos teores de manganês e

  9. Localização de robô em ambiente interno utilizando um dispositivo móvel baseado no sistema operacional android para navegação inercial

    OpenAIRE

    Pedro Ramon de Mello Silva

    2015-01-01

    Resumo: A navegação autônoma de robôs tem sido alvo de pesquisa. Um dos problemas a ser resolvido em navegação é a localização de um robô móvel enquanto este se locomove, ou seja, estimar o deslocamento e orientação para calcular a trajetória realizada. Um sistema de navegação inercial é um método de realizar a localização do robô utilizando sensores inerciais (acelerômetro, giroscópio e magnetômetro). Este trabalho apresenta a utilização de um dispositivo móvel baseado no sistema operacional...

  10. Tres aproximaciones para estimación y distribución espacio-temporal del balance hídrico: el caso de la cuenca de Cuitzeo, Michoacán, México

    OpenAIRE

    Alfredo Amador García; Erna Granados López; Manuel E. Mendoza

    2012-01-01

    La distribución espacial de la energía y los flujos de ciclo hidrológico en forma de vapor (evapotranspiración), escurrimiento e infiltración en una región, son una función de las características climáticas (precipitación, temperatura y evaporación) y del paisaje (relieve, suelo y cobertura) de un área y constituyen el llamado ciclo hidrológico. El modelo general de evaluación de cada uno de los compartimentos y flujos es el balance hídrico. Los métodos desarrollados para calcular el balance ...

  11. Characterization of thermal neutron fields for calibration of neutron monitors in accordance with great equivalent dose environment H⁎(10); Caracterização de campos de nêutrons térmicos para a calibração de monitores de nêutrons em termos da grandeza equivalente de dose ambiente H⁎(10)

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Larissa P. S. da; Silva, Felipe S.; Fonseca, Evaldo S.; Patrao, Karla C.S.; Pereira, Walsan W. [Instituto de Radioproteção e Dosimetria (LNMRI/IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil). Laboratório Nacional de Metrologia das Radiações Ionizantes; Astuto, Achilles, E-mail: larissapaizante@poli.ufrj.br [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil)

    2017-07-01

    The Laboratório Brasileiro de Nêutrons do Instituto de Radioproteção e Dosimetria (IRD/CNEN) has developed and built a thermal neutron flux facility to provide neutron fluence for dosimeters (Astuto, 2014). This fluency is obtained by four 16 Ci sources {sup 241}AmBe (α, n) positioned around the channel positioned in the center of the Thermal Flow Unit (UFT). The UFT was built with blocks of paraffin with graphite addition and graphite blocks of high purity to obtain a central field with a homogeneous thermal neutron fluence for calibration purposes with the following measurements: 1.2 x 1.2 x 1.2 m{sup 3}. The objective of this work is to characterize several points, in the thermal energy range, in terms of the equivalent ambient dose quantity H⁎(10) for calibration and irradiation of monitors neutrons.

  12. Costo-efectividad de una alternativa para la prestación de servicios de atención primaria en salud para los beneficiarios del Seguro Popular de México

    Directory of Open Access Journals (Sweden)

    Alejandro Figueroa Lara

    2016-09-01

    Full Text Available Objetivo. Calcular la razón costo-efectividad de servicios públicos y privados contratados por el Seguro Popular en primer nivel de atención. Material y métodos. Se evaluó una experiencia piloto de contratación de servicios de primer nivel de atención a la salud en el estado de Hidalgo, México, midiendo, con base en una encuesta poblacional, la calidad general y la detección de disminución de visión. Se analizó la sensibilidad mediante simulaciones de Monte Carlo. Resultados. El prestador privado es dominante en calidad y costo-efectivo para la detección de disminución de visión. Conclusiones. La compra estratégica de prestadores privados de atención primaria es promisoria para mejorar los servicios de salud y reducir los costos.

  13. Áreas potenciales para el cultivo de girasol en condiciones de temporal en Guanajuato, México

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    Enrique López-Rocha

    2018-05-01

    Full Text Available En los últimos cinco años en México se registró un incremento de 189,50 a 13 219,84 hectáreas, en la superficie de cultivo de girasol en temporal, particularmente en el estado de Guanajuato se sembró aproximadamente 450 hectáreas en 2016. Esta forma de cultivo requiere de planeación que contemple variables bioclimáticas para el óptimo desarrollo y rendimiento. El objetivo del presente trabajo fue determinar las áreas con potencial bioclimático para el establecimiento del cultivo de girasol en temporal en el estado de Guanajuato. Durante el ciclo otoño-invierno del 2016 se monitorearon y se estratificaron 45 parcelas de girasol, distribuidas en once municipios, en las que se registró el rendimiento asociado a temperatura máxima y mínima, humedad relativa, radiación solar, precipitación y evapotranspiración. Los datos de parcelas con un rendimiento mayor a 1,89 t/ha se utilizaron para generar polígonos con una saturación de 56 puntos de abundancia, para calcular la distribución potencial mediante el programa Maxent, con 23 variables bioclimáticas como predictores. Las variables con mayor contribución porcentual a la distribución potencial fueron: temperatura promedio del cuatrimestre más seco, altitud, régimen de humedad y perfil edáfico. Las áreas potenciales para el establecimiento del cultivo suman una superficie total de 317 028 hectáreas, donde el clima predominante es semicálido subhúmedo, temperatura media anual de 20 °C, precipitación media anual de 600 a 800 mm y una altitud de 500 a 1500 msnm.

  14. Modelo etiológico dos comportamentos de risco para os transtornos alimentares em adolescentes brasileiros do sexo feminino

    Directory of Open Access Journals (Sweden)

    Leonardo de Sousa Fortes

    2016-01-01

    Full Text Available Resumo: O objetivo foi construir um modelo etiológico dos comportamentos de risco para os transtornos alimentares em adolescentes brasileiros do sexo feminino. Participaram 1.358 adolescentes de quatro cidades. Foram avaliados os comportamentos de risco para os transtornos alimentares, insatisfação corporal, pressões midiáticas, autoestima, estado de humor, sintomas depressivos e perfeccionismo por intermédio de escalas psicométricas. Peso, estatura e dobras cutâneas foram aferidos para calcular o índice de massa corporal (IMC e o percentual de gordura (%G. O modelo de equação estrutural explanou 76% da variância dos comportamento de risco (F(9, 1.351 = 74,50; p = 0,001. Os achados indicaram que a insatisfação corporal mediou a relação entre as pressões midiáticas, autoestima, estado de humor, IMC, %G e os comportamentos de risco (F(9, 1.351 = 59,89; p = 0,001. Vale destacar que embora os sintomas depressivos não tenham se relacionado com a insatisfação corporal, o modelo indicou relação direta com os comportamentos de risco para os transtornos alimentares (F(2, 1.356 = 23,98; p = 0,001. Concluiu-se que somente o perfeccionismo não aderiu ao modelo etiológico dos comportamentos de risco para os transtornos alimentares em adolescentes brasileiras.

  15. Aplicativo computacional para la planeación de la producción en una empresa fabricante de autopartes

    Directory of Open Access Journals (Sweden)

    Andrea Hernández

    2008-11-01

    Full Text Available Este trabajo describe el desarrollo de un aplicativo computacional para la planeación y secuenciación de la producción en una empresa colombiana fabricante de autopartes. El aplicativo integra pronósticos de ventas y órdenes en firme para calcular el plan maestro de producción, que se secuencia en la planta de producción. Un caso de estudio muestra la funcionalidad de la aplicación propuesta y compara los resultados de las secuencias propuestas con las que resultaron de las prácticas actuales. Los resultados muestran que la implementación del aplicativo puede mejorar los niveles de servicio y la satisfacción del cliente si se cumplen ciertos prerrequisitos descritos en el artículo. / This paper describes the development of a computer application for production planning and scheduling in a Colombian auto part company. Such an application integrates sales forecasts and firm orders, to calculate a Master Production Schedule which is validated with a detailed shop floor scheduling plan. A case study illustrates the functionality of the proposed application and compares the computer-calculated production plans with the current practices. The results show that the implementation of the application can improve service levels and customer satisfaction, given some prerequisites described in the paper are met.

  16. Costo día cama servicio pensionado para una enfermedad en un hospital de Chile

    Directory of Open Access Journals (Sweden)

    Alex Medina Giacomozzi

    2015-12-01

    Full Text Available Uno de los temas de mayor complejidad en salud es la determinación de los costos involucrados en una atención de una enfermedad, por la gran cantidad de costos indirectos incurridos que provienen de los diversos servicios que directa o indirectamente intervienen, por lo que su asignación al usuario requirente, afectado por un problema de salud, ya sea de recuperación o rehabilitación, es sin lugar a dudas el problema más importante a resolver de cualquier sistema de costos. Además, es un problema ineludible pues la organización necesita tener información confiable, oportuna y lo más exacta posible sobre el costo de sus productos, para una correcta toma de decisiones, por lo que el objetivo del presente artículo es calcular el costo indirecto incurrido por procedimiento y su asignación por inductor de costos a un caso real para una atención cerrada en la unidad de pensionado de un hospital público chileno. La metodología seguida implicó identificar todas las actividades y costos involucrados en una atención, mediante la identificación de los inductores de costos y su distribución a una enfermedad en particular, siguiendo el criterio de costo por paciente-enfermedad. El resultado demuestra que es posible incorporar la valorización del día cama y, por tanto, reconocer los costos indirectos incurridos en la atención de una enfermedad en particular, lo que permite contar con un instrumento de identificación de costos, que responda a las necesidades de información para un establecimiento en concreto y que es posible replicar, con las adecuaciones pertinentes, a otros establecimientos de salud.

  17. MÉTODOS FISIOTÉCNICOS PARA ESTUDIAR ESPECIES HORTÍCOLAS BAJO AGOBIO HÍDRICO: REVISIÓN CONCEPTUAL Y METODOLÓGICA

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    E. Troyo-Diéguez

    2007-01-01

    Full Text Available El estudio del balance del agua en las plantas y cultivos de zonas secas es fundamental para comprender los procesos fisiológicos de producción y su adaptación a las condiciones ambientales donde prevalezca deficiencia de agua o estrés hídrico. Actualmente se han propuesto diferentes conceptos para caracterizar el estado hídrico en las plantas. El objetivo de este estudio fue analizar algunos de los métodos más utilizados para el estudio de plantas bajo estrés hídrico. Dichos métodos se basan en la medición del potencial hídrico y sus componentes, así como en la evaluación de la transpiración. Por su parte, el análisis de las curvas presiónvolumen permite calcular el potencial osmótico y el potencial de turgencia. Lo anterior es importante para el estudio de los cultivos bajo diferentes gradientes ambientales y para comparar ecotipos o variedades de una especie vegetal. Diversas consideraciones deben tomarse en cuenta para que su aplicación redunde en información útil para la elaboración de conclusiones válidas en investigación básica o aplicada. Dichas consideraciones deben incluir una precisa valoración acerca de la fisiología propia de la planta, que abarca necesariamente varios aspectos como la edad de la misma, época y hora de medición, estado de sanidad y funcionamiento a nivel de planta completa.

  18. From personnel dose to personal dose

    International Nuclear Information System (INIS)

    Hoefert, M.; Raffnsoe, R.C.; Tuyn, J.W.N.; Wittekind, D.

    1985-01-01

    From following the development of personnel doses at CERN over the past six years it has become evident that work in areas of induced radioactivity is the principal cause of exposure. The results of photon dose measurements free-in-air and around a phantom are presented and discussed in the light of new quantities in individual monitoring. The importance of these results, with respect to the practical situation, is discussed and the problem of phantom size is mentioned. Finally, the results of dose measurements in the phantom are presented, since such information is important in cases where it becomes necessary to transform personnel doses into personal doses. (author)

  19. Ingresos fiscales y elasticidades tributarias: estimación de las elasticidades tributarias de corto y largo plazo para los principales impuestos

    Directory of Open Access Journals (Sweden)

    Carlos Conejo Fernández

    2011-12-01

    Full Text Available Este artículo tiene como objetivo proporcionar una medición de las elasticidades de los principales impuestos del sistema tributario costarricense, de manera que permita dar señales sobre los efectos que se pueden percibir conforme sucedan los cambios en la economía y que contribuya al análisis de las situación fiscal del país.  Las estimaciones de las elasticidades se obtienen por medio de la aplicación de un modelo de regresión y se estiman las elasticidades de corto y largo plazo. Las elasticidades tributarias miden el cambio que experimentan los ingresos tributarios ante cambios en el ingreso o producción nacional. Si la recaudación depende de varios factores, lo fundamental es determinar para cuál factor es útil calcular la elasticidad, a la vez, debe tenerse presente que el valor de la elasticidad depende básicamente de la estructura impositiva y de la progresividad del sistema. La elasticidad de la recaudación tributaria es una variable de gran importancia en los análisis de la evolución fiscal y para las proyecciones de ingresos tributarios. Los resultados muestran que la elasticidad de largo plazo de los ingresos presenta un comportamiento elástico con respecto a las bases que se especificaron para cada impuesto.

  20. Cinética de desinfección para cinco desinfectantes utilizados en industria farmacéutica Disinfection kinetics of five disifectants used in pharmaceutical industry

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    Lena Carolina Echeverri Prieto

    2007-08-01

    Full Text Available Para evaluar la actividad desinfectante de cada agente químico se implementó una metodología cuantitativa por medio de la neutralización de estos con el medio Dey-Engley y recuperar las células viables después de cada ensayo y calcular la cinética de desinfección la cual es expresada como coeficiente de letalidad (k. Se observó que este valor era inversamente proporcional al tiempo de contacto para los tratamientos con B. subtilis frente a todos los desinfectantes, y para A. niger con el alcohol etílico al 70 %, el amonio cuaternario catiónico y el hipoclorito de sodio.To assess disinfectant activity from each chemical agent, a quantitative methodology was implemented by means of its neutralization with Dey-Engley medium, and thus to achieve recovery of viable cells after each assay and to estimate disinfection kynetics, which is expressed as lethal coefficient (k. It was observed that this value was proportionally inverse to contact time for treatments with B. subtilis versus all the disinfectants, and for A. niger with 70 % ethyl alcohol, ionic quaternary ammonium, and the sodium hypochlorite.

  1. The Ethanol-Chlorobenzene Aerated System as a New High-Level Dosimeter for Routine Measurements; Le Systeme Ethanol-Chlorobenzene Aere Utilise Comme Dosimetre pour les Mesures Courantes de Fortes Doses; Aehrirovannaya sistema ehtanola-khlorobenzola v kachestve novogo dozimetra vysokogo urovnya dlya provedeniya obychnykh izmerenij; Dosimetro de Etanol-Clorobenceno Saturado de Aire para la Determinacion de Intensidades Elevadas

    Energy Technology Data Exchange (ETDEWEB)

    Dvornik, I.; Zec, U.; Ranogajec, F. [Institute ' ' Ruder Boskovic' ' , Zagreb, Yugoslavia (Croatia)

    1966-11-15

    conditions experimentales. Ce rendement n'est que legerement sensible aux impuretes normales. Avec des composants de purete analytique et moindre, on obtient des rendements reproductibles compris dans une gamme de quelques pour cent de cette valeur en presence de 4% d'eau et de benzene et d'acetaldehyde ou d'acetone 2 * 10{sup -3} M. On obtient une plus grande precision dosimetrique en determinant exactement G(C1{sup )} pour des matieres donnees par etalonnage au moyen du dosimetre de Fricke. Avec 4 Degree-Sign )o de CB et 4% d'eau, toutes les qualites d'ethanol donnent G(Cl{sup -}) = 3,65 {+-} 0,05 quels que soient les adjuvants utilises. L'effet des variations de la teneur en eaii comprises entre {+-} 1 % est negligeable. On determine directement la concentration de l'acide chlorhydrique dans toute la gamme correspondant a la dose par un titrage mercurimetrique ou alcalimetrique dans l'echantillon irradie, avec une precision egale ou superieure a 1%. Des experiences incompletes avec des electrons rapides ont prouve que des systemes semblables pourraient etre interessants pour etalonner et mesurer des irradiations industrielles utilisant des faisceaux d'electrons intenses. La simplicite de la. preparation et de l'analyse, ainsi que la tres grande precision en general, font de ce nouveau dosimetre aux multiples qualites un instrument presque unique en son genre pour le calibrage dosimetrique des sources et la mesure courante des irradiations intervenant dans les procedes industriels. (author) [Spanish] El rendimiento en HCl obtenido por radiolisis mediante los rayos gamma del {sup 60}Co, expresado en funcion de. la dosis (0,05 a 100 Mrad), de la intensidad de dosis (0,5a 2500 rad s{sup -1}) y de la concentracion del clorobenceno (CB), es 5 {+-} 0,1 para concentraciones de Cb comprendidas entre 20 y 40% en condiciones experimentales muy diversas. Este rendimiento solo se altera ligeramente con las impurezas corrientes. Los componentes de pureza analitica e inferior dan

  2. Avaliação do estado ácido-básico materno com o uso de sufentanil por via subaracnóidea em diferentes doses para cesarianas e suas repercussões sobre os recém-nascidos Evaluación del estado ácido-básico materno con el uso de sufentanil por vía subaracnóidea en diferentes dosis para cesáreas y sus repercusiones sobre los recién nacidos Evaluation of maternal acid-base status after different doses of spinal sufentanil for cesarean section and its effects on the neonates

    Directory of Open Access Journals (Sweden)

    Luís Fernando Lima Castro

    2003-02-01

    Full Text Available JUSTIFICATIVA E OBJETIVOS: O sufentanil subaracnóideo em obstetrícia promove alívio imediato da dor, melhor qualidade da anestesia e analgesia pós-operatória mais prolongada, tendo como efeito colateral mais grave a depressão respiratória. Objetivou-se neste estudo avaliar o estado ácido-básico materno com o uso de sufentanil subaracnóideo em diferentes doses, associado à bupivacaína hiperbárica, para cesarianas e suas repercussões sobre os recém-nascidos. MÉTODO: Foram avaliadas 40 gestantes a termo, estado físico ASA I, com idades entre 17 e 35 anos, submetidas à cesariana eletiva sob raquianestesia e divididas em 2 grupos eqüitativos: no grupo I, receberam 12 mg de bupivacaína a 0,5% hiperbárica associados a 2,5 µg de sufentanil e no grupo II, receberam 12 mg de bupivacaína a 0,5% hiperbárica associados a 5 µg de sufentanil. Foram avaliados: estado ácido-básico materno através de gasometria arterial antes da realização da anestesia e após o nascimento do concepto, SpO2, alterações hemodinâmicas, vitalidade dos recém-nascidos através do índice de Apgar e gasometria do cordão umbilical e presença de efeitos colaterais. RESULTADOS: Os grupos mostraram-se homogêneos nos parâmetros avaliados, observando-se discreta acidose metabólica materna compensada em ambos os grupos tanto antes da realização da anestesia como logo após o nascimento do concepto; porém, sem repercussões clínicas. Os recém-nascidos apresentaram boa vitalidade e gasometrias compatíveis com a normalidade. CONCLUSÕES: A associação de bupivacaína hiperbárica a 0,5% a pequenas doses de sufentanil subaracnóideo em cesarianas mostrou ser técnica segura ao binômio materno-fetal, preservando seu estado hemodinâmico e ácido-básico.JUSTIFICATIVA Y OBJETIVOS: El sufentanil subaracnóideo en obstetricia promueve alivio inmediato del dolor, mejor calidad de la anestesia y analgesia pós-operatoria más prolongada, y que tiene como

  3. Different doses of exogenous surfactant for treatment of meconium aspiration syndrome in newborn rabbits Estudo dos efeitos de diferentes doses de surfactante exógeno para o tratamento da síndrome de aspiração de mecônio em coelhos recém-nascidos

    Directory of Open Access Journals (Sweden)

    João Cesar Lyra

    2004-01-01

    Full Text Available OBJECTIVE: To evaluate the effects of 2 different doses of exogenous surfactant on pulmonary mechanics and on the regularity of pulmonary parenchyma inflation in newborn rabbits. METHOD: Newborn rabbits were submitted to tracheostomy and randomized into 4 study groups: the Control group did not receive any material inside the trachea; the MEC group was instilled with meconium, without surfactant treatment; the S100 and S200 groups were instilled with meconium and were treated with 100 and 200 mg/kg of exogenous surfactant (produced by Instituto Butantan respectively. Animals from the 4 groups were mechanically ventilated during a 25-minute period. Dynamic compliance, ventilatory pressure, tidal volume, and maximum lung volume (P-V curve were evaluated. Histological analysis was conducted using the mean linear intercept (Lm, and the lung tissue distortion index (SDI was derived from the standard deviation of the means of the Lm. One-way analysis of variance was used with a = 0.05. RESULTS: After 25 minutes of ventilation, dynamic compliance (mL/cm H2O · kg was 0.87 ± 0.07 (Control; 0.49 ± 0.04 (MEC*; 0.67 ± 0.06 (S100; and 0.67 ± 0.08 (S200, and ventilatory pressure (cm H2O was 9.0 ± 0.9 (Control; 16.5 ± 1.7 (MEC*; 12.4 ± 1.1 (S100; and 12.1 ± 1.5 (S200. Both treated groups had lower Lm values and more homogeneity in the lung parenchyma compared to the MEC group: SDI = 7.5 ± 1.9 (Control; 11.3 ± 2.5 (MEC*, 5.8 ± 1.9 (S100; and 6.7 ± 1.7 (S200 (*P OBJETIVO: Avaliar os efeitos de duas diferentes doses de surfactante exógeno sobre a mecânica pulmonar e sobre a regularidade da expansão do parênquima pulmonar em coelhos recém-nascidos. MÉTODO: Coelhos recém-nascidos foram traqueostomizados e randomizados em quatro grupos de estudo: grupo-Controle, sem aspiração de mecônio; grupo MEC, com aspiração de mecônio e sem tratamento com surfactante exógeno; grupos S100 e S200, ambos com aspiração de mecônio e tratados

  4. Dose sculpting with generalized equivalent uniform dose

    International Nuclear Information System (INIS)

    Wu Qiuwen; Djajaputra, David; Liu, Helen H.; Dong Lei; Mohan, Radhe; Wu, Yan

    2005-01-01

    With intensity-modulated radiotherapy (IMRT), a variety of user-defined dose distribution can be produced using inverse planning. The generalized equivalent uniform dose (gEUD) has been used in IMRT optimization as an alternative objective function to the conventional dose-volume-based criteria. The purpose of this study was to investigate the effectiveness of gEUD optimization to fine tune the dose distributions of IMRT plans. We analyzed the effect of gEUD-based optimization parameters on plan quality. The objective was to determine whether dose distribution to selected structures could be improved using gEUD optimization without adversely altering the doses delivered to other structures, as in sculpting. We hypothesized that by carefully defining gEUD parameters (EUD 0 and n) based on the current dose distributions, the optimization system could be instructed to search for alternative solutions in the neighborhood, and we could maintain the dose distributions for structures already satisfactory and improve dose for structures that need enhancement. We started with an already acceptable IMRT plan optimized with any objective function. The dose distribution was analyzed first. For structures that dose should not be changed, a higher value of n was used and EUD 0 was set slightly higher/lower than the EUD value at the current dose distribution for critical structures/targets. For structures that needed improvement in dose, a higher to medium value of n was used, and EUD 0 was set to the EUD value or slightly lower/higher for the critical structure/target at the current dose distribution. We evaluated this method in one clinical case each of head and neck, lung and prostate cancer. Dose volume histograms, isodose distributions, and relevant tolerance doses for critical structures were used for the assessment. We found that by adjusting gEUD optimization parameters, the dose distribution could be improved with only a few iterations. A larger value of n could lead to

  5. Estimación de la huella hídrica para un cultivo de pitahaya amarilla (Selenicereus megalanthus

    Directory of Open Access Journals (Sweden)

    Eliana Alexandra Sánchez Bautista

    2015-10-01

    Full Text Available El presente proyecto evaluó el impacto de la huella hídrica dentro del proceso productivo de pitahaya amarilla (Selenicereus megalanthus. La huella hídrica es un indicador multidimensional que cuantifica el volumen de agua utilizado para la producción de un bien. El objetivo del presente estudio es cuantificar el consumo del recurso hídrico, para concientizar a los habitantes del municipio de Palestina, Huila sobre la importancia de la administración adecuada y eficiente del mismo. Adicional a esto, se diseñó un sistema de captación de agua para suplir las necesidades de la población en época de sequía y, de esta manera, no parar las actividades económicas por falta del recurso. Cada tipo de huella hídrica se determinó a partir de valores teóricos e información secundaria suministrada por un cultivador del municipio de Palestina. Estos valores se utilizaron como base para determinar las huellas azul, verde y gris del cultivo de pitahaya amarilla en su fase productiva. El estudio se realizó por medio del manejo del software CropWat 8.0 (propuesto por la FAO en el año 2010, el cual es un programa informático que permite calcular las necesidades hídricas de los cultivos, con base en la tierra, el clima y los datos del mismo cultivo.

  6. Propuesta para evaluar la capacidad de procesos de manufactura multivariados

    Directory of Open Access Journals (Sweden)

    Manuel Alberto Rodriguez Medina

    2014-08-01

    Full Text Available Los productos manufacturados hoy en día poseen varias características de calidad que son importantes para el cliente y cuando no están correlacionadas, se usan varios índices de capacidad, tales como el Cp, Cpk y Cpm para evaluar la habilidad que tiene el proceso de producir productos de calidad. Para el caso contrario, se encontró en la revisión de literatura, índices de capacidad propuestos para medir la capacidad de un proceso cuando las características de calidad están correlacionadas. La mayoría de las propuestas coinciden en que debe definirse una región de especificación que represente lo que el cliente desea y otra región de variación del proceso que muestre el desempeño que tiene el proceso. Adicionalmente, como resultados de la revisión anterior, se observa que los autores difieren en la forma de definir ambas regiones, oportunidad que se aprovecha para presentar una nueva propuesta, mediante la cual se definen de una manera confiable ambas regiones y que al compararlas se obtienen un par de índices de capacidad multivariados CpM y CpkM, que son extensiones de los índices univariados Cp y Cpk. Por último, se utilizan los datos de un proceso, los cuales se pueden modelar por medio de una distribución normal bivariada para calcular los índices de capacidad propuestos en este trabajo, posteriormente se comparan con el valor de otros índices de capacidad similares, propuestos por otros autores, obteniéndose un desempeño por sobre otros índices de la literatura consultada. The manufactured products have several quality characteristics that are important for the customer. When the quality characteristics are not correlated, using several indices, such as Cp, Cpk and Cpm to assess the ability of the process to produce quality products. For the opposite case was found in the literature review, proposed capability indices to measure the ability of a process when the quality characteristics are correlated. Most proposals

  7. Pocket total dose meter

    International Nuclear Information System (INIS)

    Brackenbush, L.W.; Endres, G.W.R.

    1984-10-01

    Laboratory measurements have demonstrated that it is possible to simultaneously measure absorbed dose and dose equivalent using a single tissue equivalent proportional counter. Small, pocket sized instruments are being developed to determine dose equivalent as the worker is exposed to mixed field radiation. This paper describes the electronic circuitry and computer algorithms used to determine dose equivalent in these devices

  8. On dose distribution comparison

    International Nuclear Information System (INIS)

    Jiang, Steve B; Sharp, Greg C; Neicu, Toni; Berbeco, Ross I; Flampouri, Stella; Bortfeld, Thomas

    2006-01-01

    In radiotherapy practice, one often needs to compare two dose distributions. Especially with the wide clinical implementation of intensity-modulated radiation therapy, software tools for quantitative dose (or fluence) distribution comparison are required for patient-specific quality assurance. Dose distribution comparison is not a trivial task since it has to be performed in both dose and spatial domains in order to be clinically relevant. Each of the existing comparison methods has its own strengths and weaknesses and there is room for improvement. In this work, we developed a general framework for comparing dose distributions. Using a new concept called maximum allowed dose difference (MADD), the comparison in both dose and spatial domains can be performed entirely in the dose domain. Formulae for calculating MADD values for various comparison methods, such as composite analysis and gamma index, have been derived. For convenience in clinical practice, a new measure called normalized dose difference (NDD) has also been proposed, which is the dose difference at a point scaled by the ratio of MADD to the predetermined dose acceptance tolerance. Unlike the simple dose difference test, NDD works in both low and high dose gradient regions because it considers both dose and spatial acceptance tolerances through MADD. The new method has been applied to a test case and a clinical example. It was found that the new method combines the merits of the existing methods (accurate, simple, clinically intuitive and insensitive to dose grid size) and can easily be implemented into any dose/intensity comparison tool

  9. Metodología para determinación de factores de forma de radiación aplicada a la configuración particular plano-esfera

    Directory of Open Access Journals (Sweden)

    Héctor Armando Durán Peralta

    2006-01-01

    Full Text Available En el diseño de hornos y dispositivos que calientan o enfrían sistemas mediante radiación se necesita calcular el factor de forma, el cual permite determinar la transferencia de calor por radiación entre superficies que estén a diferente temperatura. Generalmente los textos de transferencia de calor deducen y muestran la ecuación para obtener el factor de forma entre dos superficies que intercambian calor por radiación para configuraciones muy sencillas, pero no muestran cómo se hace el cálculo para geometrías y configuraciones un poco más completas. Muchos de los estudiantes que han cursado la asignatura o asignaturas de transferencia de calor quedan con la impresión de que los factores de forma se calculan sin ningún problema. Otros preguntan por qué en los textos no muestran cómo se calcula el factor de forma para configuraciones un poco más complejas o más reales. Este documento pretende responder esa inquietud, además de presentar como objetivo una estrategia de cálculo con fines netamente pedagógicos que puede ser aplicada a otras configuraciones más complejas.

  10. Nivel tecnológico de invernadero y riesgo para la salud de los jornaleros

    Directory of Open Access Journals (Sweden)

    L. D. Ortega Martínez

    2017-01-01

    Full Text Available Introducción: Lo s invernaderos se clasifican por niveles alto, medio o bajo según las tecnologías que se le adapten , con la que se crean condiciones óptimas de radiación, temperatura, humedad y dióxido de carbono que permiten mejorar la producción agrícola , así como el de sarrollo de organismos perjudiciales que se combaten aplicando plaguicidas, exponiendo a los jornaleros a sus vapores y residuos. Método: Se determinó el daño geno tóxico en muestras de células epiteliales de exfoliación bucal de los jornaleros a través de l ensayo de micronúcleos, de 40 jornaleros expuestos a plaguicidas, 20 laboraron en invernaderos de baja tecnología y 20 en invernaderis de tecnología alta. Resultados: Los de baja tecnología mostraron resultados más altos de frecuencias para todas las an ormalidades nucleares comparando con el grupo control, especialmente de cromatina condensada, picnosis, cariolisis y micro nú cleos. Al calcular el riesgo, se midió las frecuencias de micron ú cleos en razón de probabilidades (OR, para los jornaleros de inver naderos de alta tecnología el OR = 17.06 (95 % IC 3.4 - 83.7 y de baja tecnología OR = 50.66 (% IC 7.5 - 341.7. Conclusión: Los resultados indican que los jornaleros que laboran en invernaderos de baja tecnología muestran una mayor frecuencia de células con anormalidades nucleares, debido al efecto de condiciones laborales y exposición a los plaguicidas.

  11. Fatores de Risco para Infecção Pós-Craniotomia

    Directory of Open Access Journals (Sweden)

    Gustavo Palmer Irffi

    2016-10-01

    Full Text Available Justificativa e Objetivos: A infecção pós-craniotomia é um risco real para a recuperação do paciente, com aumento da morbimortalidade e, também, dos custos para o sistema de saúde. Com uma alta incidência de complicações, chegando a até 11%, é importante ter noção dos fatores de risco desse procedimento a fim de melhorar a qualidade do atendimento e da recuperação do paciente. Dessa forma, o objetivo desse artigo é definir o risco de infecção nesse procedimento; indicar a incidência de infecção de sítio cirúrgico e de meningite; apontar os principais fatores de risco; e calcular a taxa de óbito de craniotomia. Métodos: O estudo foi uma coorte retrospectiva em seis hospitais de Belo Horizonte por um período de dez anos. Dados foram colhidos e analisados buscando resultados relacionados à incidência e aos fatores de risco pós-craniotomia. Resultados: As infecções globais têm uma incidência de 8,8%, as infecções de sítio cirúrgico de 5,1% e as meningites de 2,3%. A taxa de letalidade está em 8,3%. Conclusão: Os principais fatores de risco são o escore American Society of Anesthesiologists (ASA > 2 e o uso de próteses; o uso de anestesia geral se mostrou um fator protetor em relação ao desenvolvimento de infecções.

  12. When is a dose not a dose?

    International Nuclear Information System (INIS)

    Green, Patrick

    1992-01-01

    There is confusion over radiation dose limits between the International Commission on Radiological Protection, the National Radiological Protection Board and the Ministry of Agriculture, Fisheries and Food (MAFF), reports a Friends of the Earth's radiation campaigner. MAFF is suggesting the inadequate ICRP public dose limit does not apply to public exposures which arise from environmental contamination from past radioactive discharges. (author)

  13. Estrategias para negociaciones exitosas.

    OpenAIRE

    José B. Parra V; Evelinda Santiago J.; Misael Murillo M.; Candy Atonal N.

    2010-01-01

    Las estrategias de negociación son herramientas para disminuir conflictos o para intercambiar bienes y servicios. Una negociación exitosa crea relaciones de solidaridad y propicia reciprocidad, cooperación y confianza para quienes tendrán relaciones permanentes de negociación con beneficios para ambas partes. Una estrategia de negociación exitosa requiere manejar el desarrollo del ambiente social del grupo de personas, con la finalidad de tener presente las fronteras que no pueden irrumpirse....

  14. Dose from radiological examinations

    International Nuclear Information System (INIS)

    Imamura, Keiko; Uji, Teruyuki; Sakuyama, Keiko; Fujikawa, Mitsuhiro; Fujii, Masamichi

    1976-01-01

    Relatively high gonad doses, several hundred to one thousand mR, have been observed in case of pelvis, hip-joint, coccyx, lower abdomen and lumber examination. Dose to the ovary is especially high in barium enema and I.V.P. examinations. About 12 per cent of the 4-ray examination are high-dose. The gonad dose is relatively high in examination of abdomen and lower extremities, in infants. The dose to the eyes is especially high, 1.0 to 2.5R per exposure, in temporal bone and nasal sinuses tomography. X-ray doses have been compared with dose limits recommended by ICRP and with the gonad dose from natural radiations. The gonad dose in lumbar examination, barium enema, I.V.P. etc. is as high as the maximum permissible dose per year recommended by ICRP. Several devices have been made for dose reduction in the daily examinations: (1) separating the radiation field from the gonad by one centimeter decreases the gonad dose about one-half. (2) using sensitive screens and films. In pelvimetry and in infant hip-joint examination, the most sensitive screen and film are used. In the I.V.P. examination of adult, use of MS screen in place of FS screen decreases the dose to one-third, in combination with careful setting of radiation field, (3) use of grid increases the dose about 50 percent and the lead rubber protection (0.1mm lead equivalent) decreases the gonad dose to one-thirtieth in the spinal column examination of infant, (4) A lead protector, 1mm thickness and 2.5cm in diameter, on the eyes decreases the dose to about one-eighth in the face and nead examinations. These simple and effective methods for dose reduction. Should be carried out in as many examinations as possible in addition to observing dose limits recommended by ICRP. (Evans, J.)

  15. Análisis de Mezclas Espectrales para el estudio de la deforestación y establecimiento de la línea de referencia de emisiones en el marco del programa REDD. Aplicación a la región de San Martín, Perú.

    OpenAIRE

    Garcia Rodriguez, Rafael; Natal Tello, Ángel

    2015-01-01

    La determinación de la línea histórica de deforestación como parte del establecimiento de la línea de referencia de emisiones, en el marco del programa REDD (Reducing Emissions from Deforestation and Forest Degradation), permite medir la evolución de la pérdida de bosque en un periodo definido de tiempo. El objetivo fue calcular la línea histórica de deforestación mediante estudio multitemporal para el periodo 1998-2011, en la región de San Martín (Perú), utilizando la metodología de Análisis...

  16. Criterio no asintótico para el diseño de sistemas Bonus-Malus mediante GPBM

    Directory of Open Access Journals (Sweden)

    Antonio Heras Martínez

    2002-01-01

    Full Text Available El diseño de sistemas Bonus-Malus habitualmente está basado en la distribución estacionaria de la probabilidad. Se supone que una póliza ha alcanzado el estado estacionario (n0 cuando la probabilidad de que dicha póliza pertenezca a la clase Ci es constante para todo n mayor o igual que n0 . Esta distribución estacionaria de probabilidad es sencilla de calcular. Su cálculo está basado en la Teoría de Cadenas de Markov y requiere que el sistema cumpla ciertas condiciones (sea Cadena de Markov irreducible y todos sus estados sean recurrentes en tiempo esperado finito. Podría ocurrir que estas condiciones no se cumplan y en este caso no se podría utilizar la distribución estacionaria. Por otra parte, los criterios basados en la distribución estacionaria no tienen en cuenta a las pólizas nuevas en la empresa ni a las que llevan poco tiempo. Por estos motivos, se propone un nuevo criterio que tenga en cuenta la edad de las pólizas de la cartera.

  17. Cálculo, mediante la aplicación del algoritmo de ajuste por mínimos cuadrados, de los componentes de velocidad para estaciones GNSS continuas

    Directory of Open Access Journals (Sweden)

    Jorge Moya Zamora

    2014-07-01

    Full Text Available El cálculo de la velocidad de una estación de observación continua GNSS representa un insumo fundamental en la geodesia moderna. El hecho de determinar la posición de las estaciones GNSS de forma diaria implica que se puedan establecer las series temporales de las estaciones, con base en las cuales se puede obtener información de la influencia de fenómenos que afecten el comportamiento de estas. En este artículo se plantea una descripción del algoritmo de ajuste por mínimos cuadrados adaptado y aplicado a la determinación de los componentes de velocidad de estaciones de observación continua. Además, se aplica este algoritmo para la calcular la velocidad de la estación ETCG, perteneciente al Sistema Geocéntrico para las Américas (SIRGAS.

  18. Diseño e implementación de una estrategia de control predictivo para el secado de arroz paddy

    Directory of Open Access Journals (Sweden)

    Alfonso Cubillos Varela

    2010-01-01

    Full Text Available Este artículo trata sobre la modelación y control del proceso de secado de arroz Paddy en silo inclinado usando técnicas de control predictivo. Para esto se usa un secador a escala 1,10 con capacidad de 25 kilos de grano, totalmente instrumentado donde se puede medir en línea la temperatura y humedad del grano de arroz y del medio ambiente. Además, permite medir y manipular el flujo y temperatura del aire de secado. Con el fin de diseñar el controlador, primero se obtiene un modelo dinámico basado en el principio de capa delgada, luego se diseña e implementa la estrategia de control predictivo, conocida como DMC (Dynamic Matriz Control la cual utiliza la respuesta paso y repuesta libre del sistema para calcular la acción de control óptima. Como consecuencia de este proceso se obtienen resultados prometedores del uso de este tipo de tecnología en el secado de arroz Paddy, a reducción del tiempo de secado, b evitar la pérdida de masa por sobresecado, c garantizar un secado más homogéneo y por lo tanto una mejora en la calidad del arroz y la productividad de la industria molinera de la Región.

  19. DIIFUSIÓN COLECTTIVA Y TÉRMICA PARA UN SISTEMA DE N PARTÍCULAS ATMOSFÉRICAS ASIMÉTRICAS E INTERACTUANTES

    Directory of Open Access Journals (Sweden)

    Jorge Mulia

    2012-01-01

    Full Text Available En este trabajo se propone un modelo mecánico estadístico en e cual se connsidera a la attmósfera como un gas de N partícula asímetricas e interactuantes, bajo esta consideracion se utiliza termodinámica mesoscóppica fuera de equilibrio para determinar un conjunto de ecuaciones tipo Fokker-Planc como funckciones de la posición, tiempo, veloccidad angula y la orientación molecular de cada partícula asimétrica. Usando el balance del momento lineal en el régimen difusivo se determina expresione para 1, 2 y N partículas que permiten calcular la presión que ejercen las moléculas atmosféricas asimétricas sobre otras partículas, así como la difusión térmica colectiva correspondient tes. Se obtuvo una explicación teórica de las ecuaciones de continuidad en fu unción de la velocidad angular y la orientación molecular de cada i-ésima partícula as a simétrica, de manera e balance de masa y la ley de conservació del momento lineal.

  20. Proposta para a estimação da corrupção regional no Brasil

    Directory of Open Access Journals (Sweden)

    André Carraro

    2015-12-01

    Full Text Available DOI: http://dx.doi.org/10.5007/2175-7984.2015v14n31p326 Este artigo tem por objetivo apresentar uma metodologia alternativa de estimação da corrupção regional no Brasil. Sabe-se que a corrupção afeta negativamente a eficiência dos serviços públicos, e mesmo sendo um problema antigo, somente há pouco tempo têm sido aprofundados os estudos nessa área. São poucos, e muitas vezes inconsistentes os índices com dados objetivos para calcular a corrupção. Para este novo índice, utilizamos como a principal fonte de dados a base de dados do Cadastro de Responsáveis com Contas Julgadas Irregulares (Cadirreg, já que esta se fundamenta em análise multivariada, mais especificamente no método dos componentes principais. A análise deste índice torna possível identificar os estados mais, ou menos, corruptos, para, então, o governo ter possibilidade de tomar medidas preventivas a este problema. Encontramos como estados brasileiros mais corruptos Bahia, São Paulo e Maranhão; já Acre, Rondônia e Santa Catarina apresentaram os menores índices de corrupção.

  1. Subvenciones para instituciones Directrices para gastos de ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    IDRC CRDI

    División de Administración de Subvenciones ... En la Parte 2 del Acuerdo de Subvención estándar de IDRC se incluyen los límites ... pagar los costos de sustitución (tiempo libre para personal académico) de los investigadores principales.

  2. Insignificant levels of dose

    International Nuclear Information System (INIS)

    Webb, G.A.M.; McLean, A.S.

    1977-01-01

    The procedures recommended by the International Commission on Radiological Protection (ICRP) for making decisions concerning controllable sources of radiation exposure of the public include 'justification' and 'optimisation'. The tool recommended by the ICRP for reaching these decisions is collective dose or dose commitment supplemented by consideration of doses to individuals. In both these considerations the practical problem arises of whether very small doses to large numbers of people should contribute to the final decision-making process. It may be that at levels of dose which are small increments on natural background, the relationship between dose and effect is linear even though the slope may be close to zero. If so, collective dose is a meaningful concept and the calculation of total detriment for the purpose of justification could legitimately include all doses. In the calculation of collective doses for the purpose of optimisation, which involves decisions on how much money or resource should be allocated to dose reduction, it is necessary to appraise radiation detriment realistically. At low levels of dose to the individual such as those small by comparison with variations in natural background within the UK, the risk to the individual is such that his well-being will not be significantly changed by the presence or absence of the radiation dose. These small doses, which are well below the point at which an individual attaches significance, should not carry a societal significance. Societal acceptance of risk is analysed with a view to assessing a level of possible risk, and hence dose, below which resources should not in general be diverted to secure further reduction. A formulation for collective dose commitment is proposed incorporating a cut-off to exclude insignificant doses. The implications of this formulation in practical situations are discussed

  3. Total dose meter development

    International Nuclear Information System (INIS)

    Brackenbush, L.W.

    1986-09-01

    This report describes an alarming ''pocket'' monitor/dosimeter, based on a tissue-equivalent proportional counter, that measure both neutron and gamma dose and determines dose equivalent for the mixed radiation field. This report details the operation of the device and provides information on: the necessity for a device to measure dose equivalent in mixed radiation fields; the mathematical theory required to determine dose equivalent from tissue equivalent proportional; the detailed electronic circuits required; the algorithms required in the microprocessor used to calculate dose equivalent; the features of the instrument; program accomplishments and future plans

  4. Dose reader CD-02

    International Nuclear Information System (INIS)

    Jakowiuk, A.; Kaluska, I.; Machaj, B.

    2005-01-01

    Dose Reader CD-02 is designed for measurement of dose from a long narrow band of dosimetric foil used for check up and control of electron beam dose during sterilization of materials and products on conveyor belt. Irradiated foil after processing (heating) is inserted into foil driving (moving) system and when the foil is moved across focused light beam the absorbed dose is measured and displayed at the same time at computer monitor (in form of a diagram). The absorbed dose is measured on the principle of light attenuation at selected light wavelength (foil absorbance is measured). (author)

  5. Dose conversion factors

    International Nuclear Information System (INIS)

    Kocher, D.C.; Eckerman, K.F.

    1992-01-01

    The following is discussed in this report: concepts and quantities used in calculating radiation dose from internal and external exposure. Tabulations of dose conversion factor for internal and external exposure to radionuclides. Dose conversion factors give dose per unit intake (internal) or dose per unit concentration in environment (external). Intakes of radionuclides for internal exposure and concentrations of radionuclides in environment for external exposure are assumed to be known. Intakes and concentrations are obtained, e.g., from analyses of environmental transport and exposure pathways. differences between dosimetry methods for radionuclides and hazardous chemicals are highlighted

  6. “Filtro c” para la fuente de alimentación de un inversor trifásico. Una curiosidad técnica; “CAPACITOR FILTER” TO POWER SUPLAY FOR TREE-PHASE INVERTER. A TECHNICAL CURIOSITY.

    Directory of Open Access Journals (Sweden)

    Alberto Nilo Basanta Otero

    2011-02-01

    Full Text Available Se presenta el análisis para encontrar, a partir de algunas restricciones y criterios técnicos-prácticos, unaexpresión matemática útil y también, muy fácil de recordar, que permite calcular el “Filtro C” para el casodel Rectificador Monofásico Onda Completa, tipo Puente, que garantice la Tensión Media de Directa a laentrada del Inversor Trifásico, en versiones de Variadores de Velocidad para motores de pequeñapotencia, aunque también dicha expresión podría usarse en otras aplicaciones en la que se permita unrizado del 10%. A partir de esa expresión de cálculo se deriva otra más general que puede ser utilizada encualquier otra aplicación en la que también se permita un rizado del 10% de la Tensión Media de Directa. In this document you will find a useful and easy to remember mathematical expression that will help you tocalculate the capacitance value needed in the single-phase, full-wave, bridge rectifier to be used as apower supply for a three-phase inverter in a low power variable frequency motor drive application. Also thisexpression could be used in any other application where a 10% ripple in the power supply voltage signal ispermitted.

  7. A prescrição semanal de sulfato ferroso pode ser altamente efetiva para reduzir níveis endêmicos de anemia na infância Long-term preventive mass prescription of weekly doses of iron sulfate may be highly effective to reduce endemic child anemia

    Directory of Open Access Journals (Sweden)

    Carlos Augusto Monteiro

    2002-04-01

    Full Text Available A anemia por deficiência de ferro em crianças é um dos maiores problemas nutricionais enfrentados pelos países em desenvolvimento. Estudos controlados indicam que doses intermitentes de sais de ferro podem ter eficácia semelhante à obtida com o esquema tradicional diário. O objetivo desse estudo é avaliar, em uma população onde a anemia na infância é endêmica, a efetividade da prescrição preventiva de doses semanais de sulfato ferroso a todas as crianças entre seis e 59 meses de idade por um período de seis meses. Crianças dos grupos controle e intervenção foram selecionadas a partir de uma amostra aleatória da população de crianças da cidade de São Paulo. Os pais das crianças do grupo intervenção receberam orientação nutricional e frascos de solução de sulfato ferroso com a instrução de ofertá-la aos filhos uma vez por semana até a próxima visita da equipe de pesquisa, que ocorreria em aproximadamente seis meses. Os pais das crianças do grupo controle receberam somente orientação nutricional. O efeito da intervenção foi avaliado por mudanças na concentração da hemoglobina e na prevalência de anemia. As comparações entre os dois grupos foram baseadas na "intenção-de-tratar" e todas as estimativas foram ajustadas para concentração inicial de hemoglobina, idade inicial, duração do seguimento e renda familiar. O ganho médio de hemoglobina devido à intervenção foi de 4,0 g/l e a queda na prevalência de anemia foi de mais de 50%. A intervenção foi particularmente eficiente em prevenir o declínio da concentração de hemoglobina durante os dois primeiros anos de vida. Esse estudo demonstra que, em condições similares àquelas que poderiam facilmente ser reproduzidas por programas regulares de saúde pública, a prescrição universal de doses semanais de sulfato ferroso reduz significativamente o risco de anemia na infância.Iron-deficiency anemia in children remains one of the most

  8. Enjebi Island dose assessment

    International Nuclear Information System (INIS)

    Robison, W.L.; Conrado, C.L.; Phillips, W.A.

    1987-07-01

    We have updeated the radiological dose assessment for Enjebi Island at Enewetak Atoll using data derived from analysis of food crops grown on Enjebi. This is a much more precise assessment of potential doses to people resettling Enjebi Island than the 1980 assessment in which there were no data available from food crops on Enjebi. Details of the methods and data used to evaluate each exposure pathway are presented. The terrestrial food chain is the most significant potential exposure pathway and 137 Cs is the radionuclide responsible for most of the estimated dose over the next 50 y. The doses are calculated assuming a resettlement date of 1990. The average wholebody maximum annual estimated dose equivalent derived using our diet model is 166 mremy;the effective dose equivalent is 169 mremy. The estimated 30-, 50-, and 70-y integral whole-body dose equivalents are 3.5 rem, 5.1 rem, and 6.2 rem, respectively. Bone-marrow dose equivalents are only slightly higher than the whole-body estimates in each case. The bone-surface cells (endosteal cells) receive the highest dose, but they are a less sensitive cell population and are less sensitive to fatal cancer induction than whole body and bone marrow. The effective dose equivalents for 30, 50, and 70 y are 3.6 rem, 5.3 rem, and 6.6 rem, respectively. 79 refs., 17 figs., 24 tabs

  9. Oro para Colombia

    OpenAIRE

    Rubio Forero, María Claudia

    2016-01-01

    Las mujeres han debido atravesar un largo camino partiendo de la discriminación hasta empezar un proceso de equidad en la sociedad y en el deporte, de esta manera llegar a ser parte de un evento como los Juegos Olímpicos. Esta tesis toma el caso de tres atletas colombianas y describe su proceso de formación para lograr dos medallas de oro para el país.

  10. Estrategias para negociaciones exitosas.

    Directory of Open Access Journals (Sweden)

    José B. Parra V

    2010-01-01

    Full Text Available Las estrategias de negociación son herramientas para disminuir conflictos o para intercambiar bienes y servicios. Una negociación exitosa crea relaciones de solidaridad y propicia reciprocidad, cooperación y confianza para quienes tendrán relaciones permanentes de negociación con beneficios para ambas partes. Una estrategia de negociación exitosa requiere manejar el desarrollo del ambiente social del grupo de personas, con la finalidad de tener presente las fronteras que no pueden irrumpirse. Otro aspecto importante, es el lenguaje corporal utilizado por las personas y las tácticas que se practican. El manejo de esta información permite diseñar diferentes modelos de negociaciones para cada caso específico. Este documento propone la utilización de la herramienta MONACO, diseñada por los autores, que es un software útil para encontrar los mejores tácticas posibles dentro de una negociación; basándose en el lenguaje corporal que muestra el negociante oponente durante cada oferta monetaria. El uso de este software da al negociador la oportunidad de manejar las negociaciones con mayor control, el negociador que usa el software puede elegir una estrategia de acuerdo a las relaciones que espera mantener con el negociador oponente.

  11. Dose measurements in mammography

    International Nuclear Information System (INIS)

    Kainberger, F.; Kallinger, W.

    1977-01-01

    Dose measurements at the mamma during mammography were carried out in the form of direct measurement with thermoluminescent dosimetry. Measurement was done for the in- and outcoming doses at the mamma, the dose exposure of the sternal region and the scattered rays above the symphysis, the latter as parameter for the genetic radiation exposure. As expected, the dose of the smooth radiation used for mammography showed a strong decrease at the outcome point in comparison with the income point. Surprisingly high was the scattered radiation in the sternal region. A corresponding protection by lead plates could be taken into consideration. Extremely low is the scattered radiation above the symphysis. Even measurements with the very sensitive calcium fluoride dosimeters did not reveal any practically important dose in the symphysis region. Most measurement values remained below the determinable dose of 0.3mR. Some maximal values varied in the range of 3-1 mR. (orig.) [de

  12. Dosimetric contribution of the organs of the I{sup 123}, I{sup 124} and I{sup 131} bio-kinetics in the dose estimate for euthyroid adults; Contribucion dosimetrica de los organos de la biocinetica de I{sup 123}, I{sup 124} y I{sup 131} en el estimado de dosis para adultos eutiroideos

    Energy Technology Data Exchange (ETDEWEB)

    Vasquez, A. M.; Rojas, A. R.; Castillo, D. C.; Idrogo, C. J.; Flores, U. H., E-mail: marvva@hotmail.com [Universidad Nacional de Trujillo, Av. Juan Pablo II s/n, Ciudad Universitaria, Trujillo (Peru)

    2011-10-15

    Using the formalism MIRD and the representation of Crysty-Eckerman for the thyroid adult, is demonstrated that the dosimetric contributions of source organs of the biokinetics of the radiopharmaceuticals I{sup 123}, I{sup 124} and I{sup 131} (iodine) are not significant in the dose estimate. Therefore, the total absorbed dose by the gland is its auto-dose. Equally, the reported results do not present significant differences to the results found by the Marinelli scheme (auto-dose) for the thyroid represented by a sphere of 20 grams. (Author)

  13. Registration of radiation doses

    International Nuclear Information System (INIS)

    2000-02-01

    In Finland the Radiation and Nuclear Safety Authority (STUK) is maintaining the register (called Dose Register) of the radiation exposure of occupationally exposed workers in order to ensure compliance with the principles of optimisation and individual protection. The guide contains a description of the Dose Register and specifies the responsibilities of the party running a radiation practice to report the relevant information to the Dose Register

  14. MEDIDAS DE NÚCLEO INFLACIONARIO PARA COSTA RICA

    Directory of Open Access Journals (Sweden)

    Gabriela Saborío Muñoz

    2003-07-01

    Full Text Available En este documento se elaboran y evalúan medidas alternativas de núcleo inflacionario para Costa Rica. La idea fundamental contempla al núcleo inflacionario como un indicador de la tendencia subyacente de la inflación capaz de capturar el componente del cambio total de precios común a todos los bienes y servicios, cuya persistencia se mantendría en el mediano y largo plazo y que excluye los cambios en los precios relativos de estos. La medida de núcleo inflacionario seleccionada se contrasta con el Índice de Núcleo Inflacionario (INI, indicador de inflación subyacente actualmente utilizado por el Banco Central de Costa Rica (BCCR.El Índice Subyacente de Inflación (ISI, definido como una medida de núcleo inflacionario que excluye un 30,7% del peso total del Índice de Precios al Consumidor (IPC, refleja más fielmente la tendencia subyacente de la inflación y logra capturar el movimiento más permanente del nivel general de precios, aislando las variaciones en precios relativos. Además, el ISI es fácil de calcular e interpretar lo cual ayuda a incrementar la transparencia y credibilidad de la política monetaria. También es un indicador oportuno, aumentando su valor para los que formulan la política monetaria. Por último, el ISI supera algunas de las limitaciones del INI, como son la falta de un criterio estadístico para definir el punto de corte de los bienes y servicios a excluir y el alto porcentaje del peso total del IPC eliminado. AbstractThis paper builds and evaluates several alternative measures of core inflation for Costa Rica. The chosen measure of core inflation is contrasted with the core inflation index (INI, which is the indicator of underlying inflation used today by the Central Bank of Costa Rica (BCCR. The main idea is that core inflation is a good indicator of the underlying inflation and catches the part of overall price change common to all the goods and services that is expected to persist in the

  15. Paediatric dose display

    International Nuclear Information System (INIS)

    Griffin, D.W.; Derges, S.; Hesslewood, S.

    1984-01-01

    A compact, inexpensive unit, based on an 8085 microprocessor, has been designed for calculating doses of intravenous radioactive injections for children. It has been used successfully for over a year. The dose is calculated from the body surface area and the result displayed in MBq. The operator can obtain the required dose on a twelve character alphanumeric display by entering the age of the patient and the adult dose using a hexadecimal keyboard. Circuit description, memory map and input/output, and firmware are dealt with. (U.K.)

  16. An environmental dose experiment

    Science.gov (United States)

    Peralta, Luis

    2017-11-01

    Several radiation sources worldwide contribute to the delivered dose to the human population. This radiation also acts as a natural background when detecting radiation, for instance from radioactive sources. In this work a medium-sized plastic scintillation detector is used to evaluate the dose delivered by natural radiation sources. Calibration of the detector involved the use of radioactive sources and Monte Carlo simulation of the energy deposition per disintegration. A measurement of the annual dose due to background radiation to the body was then estimated. A dose value compatible with the value reported by the United Nations Scientific Committee on the Effects of Atomic Radiation was obtained.

  17. An environmental dose experiment

    International Nuclear Information System (INIS)

    Peralta, Luis

    2017-01-01

    Several radiation sources worldwide contribute to the delivered dose to the human population. This radiation also acts as a natural background when detecting radiation, for instance from radioactive sources. In this work a medium-sized plastic scintillation detector is used to evaluate the dose delivered by natural radiation sources. Calibration of the detector involved the use of radioactive sources and Monte Carlo simulation of the energy deposition per disintegration. A measurement of the annual dose due to background radiation to the body was then estimated. A dose value compatible with the value reported by the United Nations Scientific Committee on the Effects of Atomic Radiation was obtained. (paper)

  18. Doses from portable gauges

    International Nuclear Information System (INIS)

    Linauskas, S.H.

    1988-08-01

    Field studies to measure actual radiation exposures of operators of commercial moisture-density gauges were undertaken in several regions of Canada. Newly developed bubble detector dosimeter technology and conventional dosimetry such as thermoluminescent dosimeters (TLDs), integrating electronic dosimeters (DRDs), and CR-39 neutron track-etch detectors were used to estimate the doses received by 23 moisture-density gauge operators and maintenance staff. These radiation dose estimates were supported by mapping radiation fields and accounting for the time an operator was near a gauge. Major findings indicate that gauge maintenance and servicing workers were more likely than gauge operators to receive exposures above the level of 5 mSv, and that neutron doses were roughly the same as gamma doses. Gauge operators receive approximately 75% of their dose when transporting and carrying the gauge. Dose to their hands is similar to the dose to their trunks, but the dose to their feet area is 6 to 30 times higher. Gamma radiation is the primary source of radiation contributing to operator dose

  19. Radiation dose in vertebroplasty

    International Nuclear Information System (INIS)

    Mehdizade, A.; Lovblad, K.O.; Wilhelm, K.E.; Somon, T.; Wetzel, S.G.; Kelekis, A.D.; Yilmaz, H.; Abdo, G.; Martin, J.B.; Viera, J.M.; Ruefenacht, D.A.

    2004-01-01

    We wished to measure the absorbed radiation dose during fluoroscopically controlled vertebroplasty and to assess the possibility of deterministic radiation effects to the operator. The dose was measured in 11 consecutive procedures using thermoluminescent ring dosimeters on the hand of the operator and electronic dosimeters inside and outside of the operator's lead apron. We found doses of 0.022-3.256 mGy outside and 0.01-0.47 mGy inside the lead apron. Doses on the hand were higher, 0.5-8.5 mGy. This preliminary study indicates greater exposure to the operator's hands than expected from traditional apron measurements. (orig.)

  20. Financial impact of outpatient clinic radioiodine therapy with sodium iodide I-131 for the treatment of patients with differentiated low-risk thyroid carcinoma in relation to hospital doses; Impacto financeiro da radioiodoterapia ambulatorial com iodeto de sódio I-131 para tratamento de pacientes com carcinoma diferenciado da tireóide de baixo risco em relação às doses hospitalares

    Energy Technology Data Exchange (ETDEWEB)

    Berenguer, P.F.; Chang, T.M.C.; Silva, R.A.M.; Neto, A.H.D.; Belo, I.B., E-mail: pricilaberenguer@gmail.com [Instituto de Medicina Integral Professor Fernando Figueira, Recife, PE (Brazil). Serviço de Medicina Nuclear; Santos, M.A.P. [Centro Regional de Ciências Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife (Brazil). Coordenação de Radioproteção

    2017-07-01

    Differential thyroid carcinoma (CDT) is the most prevalent endocrine malignancy in the world, with an excellent prognosis and a 10-year survival rate of over 95%. By 2013, the lowest activity of I-131 authorized by the Brazilian Unified Health System (SUS) in the therapy of patients with low-risk CDT was 3,700 MBq, requiring hospitalization. Recent studies have shown similar effectiveness between low and high doses of I-131 in the treatment of low-risk CDT. In 2014, the Ministry of Health included in the list of SUS procedures the use of lower activities (1,110 MBq and 1,850 MBq) for this purpose. The Brazilian National Nuclear Energy Commission (CNEN) also authorized the outpatient use of activity up to 1,850 MBq of I-131. Objective: To evaluate the financial impact of the adoption of ambulatory radioiodine therapy in patients with CDT of low-risk when compared to the hospital dose. Methods: Analysis of patients with CDT low-risk who were treated with an outpatient dose of I-131 from August / 2014 to January / 2017 at a nuclear medicine service in Recife, PE, Brazil. The cost of outpatient versus hospital doses was calculated. Results: A total of 289 patients underwent low doses of iodine therapy were evaluated, resulting in a savings of R$227,793.80. Conclusion: Outpatient radioiodine therapy in the treatment of patients with CDT of low-risk resulted in a 61.10% reduction in SUS expense, in addition to enabling faster care.

  1. Braquiterapia de alta taxa de dose no Brasil High-dose rate brachytherapy in Brazil

    Directory of Open Access Journals (Sweden)

    Sérgio Carlos Barros Esteves

    2004-10-01

    Full Text Available A braquiterapia de alta taxa de dose foi introduzida em nosso meio em janeiro de 1991. Desde então, houve uma mudança significativa na abordagem das neoplasias malignas em relação às vantagens do novo método, e também resolução da demanda reprimida de braquiterapia para as neoplasias ginecológicas. Nos primeiros dez anos de atividade, o Brasil tratou, em 31 serviços, 26.436 pacientes com braquiterapia, sendo mais de 50% das pacientes portadoras de neoplasias do colo uterino. Este estudo mostra o número e o perfil de pacientes tratados com esse método e a sua distribuição no território nacional, deixando explícito o benefício da braquiterapia de alta taxa de dose para o Brasil.High-dose rate brachytherapy was first introduced in Brazil in January 1991. Significant changes in the management of malignant neoplasms were observed since utilization of high-dose rate brachytherapy. The high number of gynecological patients awaiting for brachytherapy also decreased during this period. In the first ten years 26,436 patients were treated with high-dose rate brachytherapy. More than 50% of these patients presented neoplasms of the uterine cervix. In this study we present the number and profile of the patients treated with high-dose rate brachytherapy as well as the distribution of these patients in the Brazilian territory, proving the benefit of the use of high-dose rate brachytherapy in Brazil.

  2. Feasibility of the use of PET/CT with {sup 1}8F-colina to increase the dose in traprostaticas lesions in radiotherapy of prostate cancer treatment; Viabilidad del uso de la PET/TC con {sup 1}8F-colina para aumentar la dosis en las lesiones intraprostaticas en tratamientos de radioterapia de cancer de prostata

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Hernandez, T.; Vicedo Gonzalez, A.; Pastor Peidro, J.; Lopez Torrecilla, J.; Rosello Ferrando, J.; Brualla Congalez, L.; Granero Cabanero, D.; Ferrer Rebolleda, J.; Sanchez Jurado, R.

    2013-07-01

    This paper explores the viability of an escalation of doses higher than 80 Gy in intraprostatics lesions, defined by 18FFluorocolina PET/CT, analyzing the variation of the dose in the organs of risk with respect to traditional planning with CT. (Author)

  3. Dosimetric evaluation in organs of the Tc{sup 99m}, I{sup 123} bio-kinetics to estimate dose in thyroid children 1 and 5 years; Evaluacion dosimetrica en organos de la biocinetica del Tc{sup 99m}, I{sup 123} para estimar dosis en tiroides ninos 1 y 5 anos

    Energy Technology Data Exchange (ETDEWEB)

    Vasquez, A. M.; Quispe, R.; Vasquez, D. J.; Rocha, M. D.; Morales, N. R.; Marin, R. K. [Universidad Nacional de Trujillo, Av. Juan Pablo II s/n, Ciudad Universitaria, Trujillo (Peru); Zelada, A. L., E-mail: marvva@hotmail.com [Universidad Cesar Vallejo, Grupo de Fisica Medica, Av. Larco s/n, Trujillo (Peru)

    2012-10-15

    Using the formalism MIRD and the representation of Cristy-Eckerman for the thyroid in children of 1 and 5 years, is demonstrated that the dosimetric contribution of the organs of I{sup 123} (iodure) bio-kinetics is not significant in the dose estimate. The total dose absorbed by the gland is its auto dose. The dosimetric contribution of the organs source of the Tc{sup 99m} (pertechnetate) bio-kinetics in the gland is significant in the dose estimate like to be ignored. The reported results for the iodure are not significantly different to the found for the Marinelli scheme (auto-dose) for thyroid represented by a sphere of 1,78 and 3,45 grams. (Author)

  4. Effective dose equivalent

    International Nuclear Information System (INIS)

    Huyskens, C.J.; Passchier, W.F.

    1988-01-01

    The effective dose equivalent is a quantity which is used in the daily practice of radiation protection as well as in the radiation hygienic rules as measure for the health risks. In this contribution it is worked out upon which assumptions this quantity is based and in which cases the effective dose equivalent can be used more or less well. (H.W.)

  5. Doses from radiation exposure

    International Nuclear Information System (INIS)

    Menzel, H-G.; Harrison, J.D.

    2012-01-01

    Practical implementation of the International Commission on Radiological Protection’s (ICRP) system of protection requires the availability of appropriate methods and data. The work of Committee 2 is concerned with the development of reference data and methods for the assessment of internal and external radiation exposure of workers and members of the public. This involves the development of reference biokinetic and dosimetric models, reference anatomical models of the human body, and reference anatomical and physiological data. Following ICRP’s 2007 Recommendations, Committee 2 has focused on the provision of new reference dose coefficients for external and internal exposure. As well as specifying changes to the radiation and tissue weighting factors used in the calculation of protection quantities, the 2007 Recommendations introduced the use of reference anatomical phantoms based on medical imaging data, requiring explicit sex averaging of male and female organ-equivalent doses in the calculation of effective dose. In preparation for the calculation of new dose coefficients, Committee 2 and its task groups have provided updated nuclear decay data (ICRP Publication 107) and adult reference computational phantoms (ICRP Publication 110). New dose coefficients for external exposures of workers are complete (ICRP Publication 116), and work is in progress on a series of reports on internal dose coefficients to workers from inhaled and ingested radionuclides. Reference phantoms for children will also be provided and used in the calculation of dose coefficients for public exposures. Committee 2 also has task groups on exposures to radiation in space and on the use of effective dose.

  6. Gonad dose in cineurethrocystography

    International Nuclear Information System (INIS)

    Ardran, G.M.; Dixon-Brown, A.; Fursdon, P.S.

    1978-01-01

    The technical factors used for cineurethrocystography for the true lateral projection in females are given. The mid-line radiation dose has been measured with LiF TLD inserted into the vagina in 19 examinations. The average dose recorded was 148 mrad, the range being 50 to 306 mrad, the average number of cine frames exposed was 96. Data obtained using a Rando phantom indicated that the average ovary dose would be 30% greater than the mid-line dose since the near ovary receives a higher dose than the more distant one. The technique used for men is also given, the average gonad dose in six men being 123 mrad, range 56 to 243 mrad when simple lead foil gonad protection was used; the average number of cine frames was 107. The dose in one man without gonad protection was 1575 mrad for 112 cine frames. The results for both sexes compare favourably with those of others reported in the literature and with gonad doses recorded in typical IVP examinations. (author)

  7. Internal dose estimates

    International Nuclear Information System (INIS)

    Wrenn, M.E.

    1977-01-01

    Internal doses, the procedures for making them and their significance has been reviewed. Effects of uranium, radium, lead-210, polonium-210, thorium in man are analysed based on data from tables and plots. Dosimetry of some ingested nuclides and inhalation dose due to radon-222, radon-220 and their daugther products are discussed [pt

  8. Occupational dose constraint

    International Nuclear Information System (INIS)

    Heilbron Filho, Paulo Fernando Lavalle; Xavier, Ana Maria

    2005-01-01

    The revision process of the international radiological protection regulations has resulted in the adoption of new concepts, such as practice, intervention, avoidable and restriction of dose (dose constraint). The latter deserving of special mention since it may involve reducing a priori of the dose limits established both for the public and to individuals occupationally exposed, values that can be further reduced, depending on the application of the principle of optimization. This article aims to present, with clarity, from the criteria adopted to define dose constraint values to the public, a methodology to establish the dose constraint values for occupationally exposed individuals, as well as an example of the application of this methodology to the practice of industrial radiography

  9. Implantación de placas solares para mejorar el consumo en calderas marinas

    OpenAIRE

    Rodríguez Ramos, Miguel Daniel

    2017-01-01

    En el presente trabajo se realizarán cálculos a partir de un ciclo de vapor obtenido de una instalación de vapor marina. A partir de estos datos, se calculará el consumo de combustible. Al mismo tiempo se procederá a realizar los cambios oportunos en los valores de partida del ciclo debido a la instalación de las placas solares, y en consecuencia se calcularán nuevamente los valores de consumo, rendimiento, etc. Además, se tendrán en cuenta 3 disposiciones diferentes en l...

  10. Vaporizador artesanal de éter para cirurgia experimental em pequenos roedores

    Directory of Open Access Journals (Sweden)

    Marcus Vinicius Henriques Brito

    1998-01-01

    Full Text Available O presente trabalho descreve modelo experimental de vaporizador artesanal de éter, modificado a partir do modelo de WAYNFORTH & FLECKNELL, a fim de manter fluxo contínuo e homogêneo do anestésico em cirurgias onde se utiliza roedores de pequeno porte como animais de experimentação. O sistema é construído a partir de material encontrado em casas de materiais para aquários, sonda e tubo de ensaio de uso hospitalar, base de madeira e campânula de vidro confeccionada em vidraçaria. Como vantagens do sistema pode-se citar a manutenção do animal em plano anestésico sem que haja necessidade de contínuas "induções" com algodão embebido em éter e ofertado por via nasal, com perda do excesso para o meio ambiente e inalação do mesmo por quem conduz o experimento. Diminui-se assim quantidade de anestésico total gasto, devido manter-se níveis de oferta mais homogêneas por um fluxo contínuo de acordo com o plano anestésico do animal. Consegue-se também através do consumo aferido no tubo de ensaio, calcular aproximadamente o volume / minuto inalado, consumindo-se em média 5 ml de éter em uma hora de anestesia para ratos com 300g, obtendo com isto economia da substância, melhor controle da quantidade inalada pelo animal e redução da poluição do meio ambiente pelo mesmo.This paper described a homemade ether vaporizer, changed from WAYNFORTH & FLECKNELL model for small animals. The device is build with hospital material and products bought in aquarium’s shops. Their advantages are maintenance of anesthetic level without successive "inductions" by inhalatory nasal ether ; ether consumption of 5 ml per hour in animals with 300 g ; smaller ambient pollution and small cost. The disadvantages are a hardness and reduction of the plastic tubes after approximately 150 hour in use, by ether action and the necessity of experience acquisition in anesthetic manipulation with the device

  11. Tiempo para un cambio

    Science.gov (United States)

    Woltjer, L.

    1987-06-01

    En la reunion celebrada en diciembre dei ano pasado informe al Consejo de mi deseo de terminar mi contrato como Director General de la ESO una vez que fuera aprobado el proyecto dei VLT, que se espera sucedera hacia fines de este aAo. Cuando fue renovada mi designacion hace tres aAos, el Consejo conocia mi intencion de no completar los cinco aAos dei contrato debido a mi deseo de disponer de mas tiempo para otras actividades. Ahora, una vez terminada la fase preparatoria para el VLT, Y habiendose presentado el proyecto formalmente al Consejo el dia 31 de marzo, y esperando su muy probable aprobacion antes dei termino de este ano, me parece que el 10 de enero de 1988 presenta una excelente fecha para que se produzca un cambio en la administracion de la ESO.

  12. Dose response relationship at low doses

    International Nuclear Information System (INIS)

    Schull, W.J.

    1992-01-01

    The data that have accrued in Hiroshima and Nagasaki on the effects of ionizing radiation on the developing human brain are reviewed. Effects considered are severe mental retardation, lowered IQ scores, decline in school performance, seizures, other neuropsychological effects, and small head size. All these factors may be related to radiation doses received by the mother during pregnancy. (L.L.) 3 figs., tab., 7 refs

  13. Establishment and Study of Dose Fields for the Irradiation of Experimental Animals with High-Energy Protons; Creation et Etude de Champs de Rayonnements pour l'Irradiation d'Animaux de Grande Taille par des Protons de Haute Energie; Sozdanie i issledovanie doznykh polej dlya oblucheniya ehksperimental'nykh zhivotnykh protonami bol'shoj ehnergii; Produccion y Estudio de Campos Radia Torios para la Exposicion de Animales de Laboratorio a Protones de Elevada Energia

    Energy Technology Data Exchange (ETDEWEB)

    Afanas' ev, V. P.; Keirim-Markus, I. B.; Kuznecova, S. S.; Litvinova, Je. G.; Sokolova, I. K.; Stukina, L. E.

    1964-03-15

    Present-day accelerators make it possible to obtain beams of protons which have adequate intensity but are not suitable for the general irradiation of large experimental animals. Using the synchrotron of the Joint Institute of Nuclear Research it has been shown that with the aid of absorbers it is possible to expand a proton beam to the dimensions required, without introducing the accompanying radiations. Dose fields, uniform within {+-} 10%, in which primary protons constitute between 99 and 88% of the tissue dose, were obtained for irradiation of dogs with protons of energy 510, 250 and 120 MeV. The tissue doses and the radiation composition were studied in a dog phantom. Irradiation conditions for ensuring uniform radiation of the dog's body are proposed. Various questions of high-energy proton dosimetry are discussed, and the use of different types of dosimeter are considered in this connection. The paper also describes a method of determining the contribution of cascade neutrons to the proton flux, using activation detectors. (author) [French] Les accelerateurs actuels permettent d'obtenir des faisceaux de protons d'une intensite suffisante mais impropres a l'irradiation generale de grands animaux d'experience. A l'aide du synchrocyclotron OIAI, on a montre que le recours aux absorbants permet d'elargir le faisceau de protons jusqu'aux dimensions voulues sans y introduire de rayonnements secondaires. Pour irradier des chiens par des protons de 510, 250 et 120 MeV, on a pu ainsi realiser des champs de rayonnements uniformes a {+-}10% pres, dans lesquels les protons primaires constituaient 99 a 88% de la dose tissulaire. Les auteurs ont etudie des doses tissulaires et la composition du rayonnement a l'interieur d'un fantome de chien. Ils indiquent dans quelles conditions on assure une irradiation uniforme du corps de l'animal. Les auteurs examinent plusieurs questions relatives a la dosimetrie des neutrons de grande energie. Ils justifient l'emploide divers

  14. Synchronized dynamic dose reconstruction

    International Nuclear Information System (INIS)

    Litzenberg, Dale W.; Hadley, Scott W.; Tyagi, Neelam; Balter, James M.; Ten Haken, Randall K.; Chetty, Indrin J.

    2007-01-01

    Variations in target volume position between and during treatment fractions can lead to measurable differences in the dose distribution delivered to each patient. Current methods to estimate the ongoing cumulative delivered dose distribution make idealized assumptions about individual patient motion based on average motions observed in a population of patients. In the delivery of intensity modulated radiation therapy (IMRT) with a multi-leaf collimator (MLC), errors are introduced in both the implementation and delivery processes. In addition, target motion and MLC motion can lead to dosimetric errors from interplay effects. All of these effects may be of clinical importance. Here we present a method to compute delivered dose distributions for each treatment beam and fraction, which explicitly incorporates synchronized real-time patient motion data and real-time fluence and machine configuration data. This synchronized dynamic dose reconstruction method properly accounts for the two primary classes of errors that arise from delivering IMRT with an MLC: (a) Interplay errors between target volume motion and MLC motion, and (b) Implementation errors, such as dropped segments, dose over/under shoot, faulty leaf motors, tongue-and-groove effect, rounded leaf ends, and communications delays. These reconstructed dose fractions can then be combined to produce high-quality determinations of the dose distribution actually received to date, from which individualized adaptive treatment strategies can be determined

  15. Low doses effects

    International Nuclear Information System (INIS)

    Tubiana, M.

    1997-01-01

    In this article is asked the question about a possible carcinogens effect of low dose irradiation. With epidemiological data, knowledge about the carcinogenesis, the professor Tubiana explains that in spite of experiments made on thousand or hundred of thousands animals it has not been possible to bring to the fore a carcinogens effect for low doses and then it is not reasonable to believe and let the population believe that low dose irradiation could lead to an increase of neoplasms and from this point of view any hardening of radiation protection standards could in fact, increase anguish about ionizing radiations. (N.C.)

  16. Tasas efectivas del impuesto de renta para sectores de la economía colombiana entre el 2000 y el 2015

    Directory of Open Access Journals (Sweden)

    Jairo Orlando Villabona Robayo

    2017-09-01

    Full Text Available El principal objetivo de este trabajo es calcular la tasa efectiva del impuesto neto de renta generado por las personas jurídicas, pertenecientes a cada uno de los sectores de la economía colombiana, usando la información disponible en los agregados de declaraciones de renta de la Dirección de Impuestos y Aduanas Nacionales (dian, durante el periodo 2000-2015. Las tasas efectivas obtenidas muestran que el impuesto neto de renta real pagado por las personas jurídicas no es tan alto como se cree, además de que los valores de estas tasas presentan diferencias significativas, para los diferentes sectores económicos, debido a la existencia de beneficios tributarios que impactan de forma diferente a cada sector. Estas diferencias demuestran la inequidad horizontal del sistema tributario colombiano, dado que sectores que no son tan relevantes en generación de empleo, tales como el financiero y el minero, fueron los que presentaron los mayores montos de beneficios tributarios.

  17. Software efical para la gestión eficiente de motores en la industria; Software Efical for Efficient Management of Motors in the Industry

    Directory of Open Access Journals (Sweden)

    Elías V de la Rosa Masdueño

    2011-02-01

    Full Text Available En este trabajo se explica el diseño, e implementación de una herramienta capaz de controlar y gestionareficientemente los motores eléctricos de una industria. Para ello se elaboró un software de fácil manejoque resolviera el problema y que además brindara otras opciones a los usuarios que hicieran uso delmismo. EFICAL®, controla el inventario de los motores y sus equipos accionados, sus parámetrosnominales, mantenimientos y ensayos, permite calcular la eficiencia por distintos métodos y brinda ademásdatos de catálogos de diversos fabricantes.  This work explains the developing and application of a software tool for efficient management of electricmotors in the industry. For this it was develop friendly software that solve the problem and more over givesanother option to users. EFICAL®, controls the motor inventory and the equipment that they drive, theirnominal parameters, maintenance, and testing; also allow the efficiency calculations by various methodsand gives the catalog data of some manufacturers.

  18. Comparison in the calculation of committed effective dose using the ICRP 30 and ICRP 60 models for a repeated incorporation by inhalation of I-125; Comparacion en el calculo de la dosis efectiva comprometida usando los modelos del ICRP 30 y del ICRP 60 para una incorporacion repetida por inhalacion de I-125

    Energy Technology Data Exchange (ETDEWEB)

    Carreno P, A.L.; Cortes C, A. [CNSNS, Dr. Barragan 779, Col. Narvarte, Mexico D.F. (Mexico); Alonso V, G.; Serrano P, F. [IPN, Edificio de Fisica Avanzada Zacatenco, 07300 Mexico D.F. (Mexico)

    2005-07-01

    Presently work, a comparison in the calculation of committed effective dose using the models of the ICRP 30 and those of the ICRP 60 for the analysis of internal dose due to repeated incorporation of I-125 is shown. The estimations of incorporated activity are obtained starting from the proportionate data for an exercise of inter comparison, with which it should be determined the internal dose later on. For to estimate the initial activity incorporated by repeated dose was assumed that this it was given through of multiple individual incorporations which happened in the middle points of the monitoring periods. The results using the models of the ICRP 30 and of the ICRP 60 are compared and the causes of the differences are analyzed. (Author)

  19. Calculation of dose absorbed for the verification of the calibration curves UH-Density electronic relative obtained with various mannequins; Calculo de dosis absorbida para la verificacion de las curvas de calibracion UH-Densidad electronica relativa obtenidas con distintos maniquies

    Energy Technology Data Exchange (ETDEWEB)

    Perez Alvarez, M. E.; Sena Espinel, E. de; Delgado Aparicio, J. M.; Martin Rincon, C.; Garcia Repiso, S.; Ramos Pacho, J. A.; Verde Velasco, J. M.; Gomez Gonzalez, N.; Cons Perez, N.; Saez Beltran, M.

    2013-07-01

    In order to discern with what calibration curve is obtained a more accurate dosimetry distribution, dose measurements are carried out on the treatment unit and the values found are evaluated. (Author)

  20. Simulación con Monte Carlo para dosimetría de 153Samario-HM en un modelo anatómico geométrico de rodilla humana

    Directory of Open Access Journals (Sweden)

    Hardy Pérez Alberto Ernesto

    2010-01-01

    Full Text Available El 153Sm-hm es una nueva opción para realizar sinovectomía por radiación, que actualmente se encuentra en valoración. Este trabajo tiene como objetivo calcular la dosis absorbida en tejidos articulares proporcionada por la administración de 153Sm-hm intraarticular, utilizando la simulación de Monte Carlo, en una propuesta de un modelo simplificado anatómico geométrico de la articulación de la rodilla. Esto con el propósito de aportar datos que apoyen la administración segura y eficaz del radiofármaco en estudio a pacientes con enfermedad reumática de la articulación de la rodilla. Se concluye que la actividad administrada de 153Sm-hm por vía intra-articular es de 370 MBq para conseguir una dosis absorbida en membrana sinovial de 110 Gy, considerada como la dosis de ablación de la mencionada membrana.

  1. Diseño de un sistema de acumulación de costos para la micro, pequeña y mediana industria panadera

    Directory of Open Access Journals (Sweden)

    Marysela C. Morillo Moreno

    2006-01-01

    Full Text Available Las micro, pequeñas y medianas industrias (MPyMI son fundamentos en una economía sólida, ellas deben diseñar estrategias gerenciales y de apoyo acorde a sus características que les permitan mejorar su competitividad y buscar su consolidación; de allí la necesidad de contar con sistemas de acumulación de costos que generen información apropiada, oportuna y detallada. Luego de un diagnóstico realizado en las industrias panaderas del municipio Barinas, estado Barinas, se constató que éstas son en su mayoría MPyMI, y que no poseen un sistema de acumulación de costos adecuado que permita calcular costos de producción precisos para la planificación, control y toma de decisiones. Por ello, se presentan los resultados de una investigación proyectiva ubicada en el nivel comprensivo, en la cual se diseña un sistema de costos adaptado a las necesidades de estas industrias, compatible con la naturaleza de sus actividades fabriles, a objeto de facilitar y difundir su uso. Se propone un Sistema de Acumulación de Costos Híbrido, a partir de la combinación del sistema de costos por proceso y del sistema de costos por operaciones, para obtener información sistemática, oportuna y confiable, de los costos de producción para la toma de decisiones, dotados a la vez de procedimientos y mecanismos de control.

  2. Un método híbrido para resolver el problema de control óptimo de semáforos

    Directory of Open Access Journals (Sweden)

    Allende Alonso, Sira

    2009-01-01

    Full Text Available El objetivo de este trabajo es resolver un problema de control óptimo que consiste en asignar tiempos a luces de semáforos que regulan cruces de dos calles con los dos sentidos de circulación. El criterio de comparación a considerar se expresa en una función objetivo a minimizar que puede ser: longitud de las colas, cantidad de vehículos en el peor de los casos, tiempo de espera, una combinación de las anteriores, entre otras posibilidades. De esta forma se obtiene un modelo tipo problema de optimización con restricciones de equilibrio, en particular con restricciones de complementariedad lineal. Para su solución, proponemos un método híbrido que combina una heurística, tipo recocido simulado, para calcular una buena aproximación a la solución, que luego será mejorada con un algoritmo quasi-Newton para problemas de optimización no suaves. Además, presentaremos algunos ejemplos numéricos. ABSTRACT Let us consider an intersection of two two-way streets. We want to solve the problem of finding the switch times of the corresponding traffic lights minimizing a certain criterion, such as the length of the queues, the number of vehicles at the worst queue, waiting time, a combination, etc. The resulting model is an optimization problem with equilibrium constraints, namely a linear complementarity constraints problem. In this work we propose a hybrid solution strategy where an approximation to the solution is computed by means of a simulated annealing algorithm and then it is improved by a quasi-Newton method for non-smooth optimization problems. We will also present some numerical examples.

  3. Principales métodos para el cálculo de la lente intraocular después de la cirugía refractiva corneal

    Directory of Open Access Journals (Sweden)

    Taimí Cárdenas Díaz

    Full Text Available Con el surgimiento y el desarrollo de la cirugía refractiva corneal se han podido corregir quirúrgicamente a millones de pacientes con defectos refractivos. Con el cursar de los años comienza a opacarse fisiológicamente el cristalino, y disminuye la agudeza visual en estos pacientes a quienes se les modificó la curvatura corneal. Ante la necesidad de remover el cristalino y de calcular una lente intraocular de potencia adecuada para conseguir la emetropía, surge un nuevo reto a la Oftalmología. El cálculo de la lente intraocular en pacientes con cirugía refractiva corneal es mucho más complejo, pues además de tener longitudes axiales extremas, se añaden factores por la intervención previa que alteran la predictibilidad del resultado visual, con la aplicación de las fórmulas de cálculo de lente intraocular existentes. Se han descrito varios métodos que permiten determinar correctamente la potencia de la lente a implantar, dependiendo de los datos de los que se dispongan; de ahí la motivación para realizar una revisión de diferentes publicaciones con el propósito de describir los principales métodos empleados para realizar el cálculo de la lente intraocular en estos pacientes. Se utilizó la plataforma Infomed, específicamente la Biblioteca Virtual de Salud, con todos sus buscadores.

  4. Determination of the absorbed dose rate to a person exposed to a spent source of {sup 60}Co for radiotherapy; Determinacion de la rapidez de dosis absorbida a una persona expuesta a una fuente gastada de {sup 60}Co para radioterapia

    Energy Technology Data Exchange (ETDEWEB)

    Garcia M, T.; Angeles C, A.; Benitez, J. A.; Ruiz C, M. A., E-mail: teodoro.garcia@inin.gob.mx [ININ, Departamento de Proteccion Radiologica, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2016-09-15

    In this work the analysis of absorbed dose rate to a person in made due to the exposure to a spent source of {sup 60}Co of radiotherapy, which has been removed from its shielding clandestinely to sell the shielding as scrap. During the removal of the source of their shielding the people were necessarily exposed to the field of gamma radiation. The activity of the source is considered to be 2595 Ci at the exposure time and to determine the rate of absorbed dose to different organs and the velocity of effective absorbed dose to which the person (s) who manipulated the source of {sup 60}Co were considered three plausible scenarios of manipulation of the source , through modeling with MCNP5. For the execution of the scenarios and the determination of the absorbed doses, two different phantoms are considered. The results obtained for each scenario show that the dose rates to which the people who manipulated the source without the shielding were exposed are extremely high, and in short time the lethal dose is reached. (Author)

  5. Point absorbed dose verification for volumetric modulated arc therapy plans. A comparative study between ionization microchamber and chamber array; Verificacion de dosis absorbida en un punto para planes de arcoterapia volumetrica modulada. Estudio comparativo entre microcamara de ionizacion y matriz de camaras

    Energy Technology Data Exchange (ETDEWEB)

    Caudepon Moreno, F.; Pizarro Trigo, F.; Sanchez Jimenez, J.; Nunez Martinez, L.; Morillas Ruiz, J.; Palomo Llinares, R.

    2016-10-01

    According to the international recommendations a quality control must be made for IMRT treatments before these can be delivered. These recommendations are applied to volumetric modulated arc therapy treatments in our Department. As a part of the verifications chain, measurements of absorbed dose in a phantom point and in the phantom volume are made for a specific patient with ionization chamber and ionization chambers array, respectively. The aim of this issue is to compare measurements of absorbed dose between these two kinds of detectors. The predictions of absorbed dose from Treatment Planning System are taken as the reference one. The differences among these measurements and the reference are calculated for 105 specific patients. A statistical analysis shows that the measurements of absorbed dose with chamber and array are strongly correlated. This result allows us to eliminate from our verifications chain the measurements of absorbed dose in a phantom point with ionization chamber because these ones are included in measurements of absorbed dose in the volume with a very small statistic risk. As a result, much time can be saved in the verifications process without any lack of quality. (Author)

  6. Para-Hermitian and para-quaternionic manifolds

    International Nuclear Information System (INIS)

    Ivanov, S.; Zamkovoy, S.

    2003-10-01

    A set of canonical para-Hermitian connections on an almost para-Hermitian manifold is defined. A Para-hermitian version of the Apostolov-Gauduchon generalization of the Goldberg-Sachs theorem in General Relativity is given. It is proved that the Nijenhuis tensor of a Nearly para-Kaehler manifolds is parallel with respect to the canonical connection. Salamon's twistor construction on quaternionic manifold is adapted to the para-quaternionic case. A locally conformally hyper-para-Kaehler (hypersymplectic) flat structure with parallel Lee form on the Kodaira-Thurston complex surfaces modeled on S 1 x SL (2, R)-tilde is constructed. Anti-self-dual locally conformally hyper-para-Kaehler (hypersymplectic) neutral metrics with non vanishing Weyl tensor are obtained on the Inoe surfaces. An example of anti-self-dual neutral metric which is not locally conformally hyper-para-Kaehler (hypersymplectic) is constructed. (author)

  7. Para-Hermitian and para-quaternionic manifolds

    Energy Technology Data Exchange (ETDEWEB)

    Ivanov, S [University of Sofia ' St. Kl. Ohridski' , Faculty of Mathematics and Informatics, Sofia (Bulgaria) and Abdus Salam International Centre for Theoretical Physics, Trieste (Italy); Zamkovoy, S [University of Sofia ' St. Kl. Ohridski' , Faculty of Mathematics and Informatics, Sofia (Bulgaria)

    2003-10-01

    A set of canonical para-Hermitian connections on an almost para-Hermitian manifold is defined. A Para-hermitian version of the Apostolov-Gauduchon generalization of the Goldberg-Sachs theorem in General Relativity is given. It is proved that the Nijenhuis tensor of a Nearly para-Kaehler manifolds is parallel with respect to the canonical connection. Salamon's twistor construction on quaternionic manifold is adapted to the para-quaternionic case. A locally conformally hyper-para-Kaehler (hypersymplectic) flat structure with parallel Lee form on the Kodaira-Thurston complex surfaces modeled on S{sup 1} x SL (2, R)-tilde is constructed. Anti-self-dual locally conformally hyper-para-Kaehler (hypersymplectic) neutral metrics with non vanishing Weyl tensor are obtained on the Inoe surfaces. An example of anti-self-dual neutral metric which is not locally conformally hyper-para-Kaehler (hypersymplectic) is constructed. (author)

  8. Doses from radioactive methane

    International Nuclear Information System (INIS)

    Phipps, A.W.; Kendall, G.M.; Fell, T.P.; Harrison, J.D.

    1990-01-01

    A possible radiation hazard arises from exposure to methane labelled with either a 3 H or a 14 C nuclide. This radioactive methane could be released from a variety of sources, e.g. land burial sites containing radioactive waste. Standard assumptions adopted for vapours would not apply to an inert alkane like methane. This paper discusses mechanisms by which radioactive methane would irradiate tissues and provides estimates of doses. Data on skin thickness and metabolism of methane are discussed with reference to these mechanisms. It is found that doses are dominated by dose from the small fraction of methane which is inhaled and metabolised. This component of dose has been calculated under rather conservative assumptions. (author)

  9. Controllable dose; Dosis controlable

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez R, J T; Anaya M, R A [ININ, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    2004-07-01

    With the purpose of eliminating the controversy about the lineal hypothesis without threshold which found the systems of dose limitation of the recommendations of ICRP 26 and 60, at the end of last decade R. Clarke president of the ICRP proposed the concept of Controllable Dose: as the dose or dose sum that an individual receives from a particular source which can be reasonably controllable by means of any means; said concept proposes a change in the philosophy of the radiological protection of its concern by social approaches to an individual focus. In this work a panorama of the foundations is presented, convenient and inconveniences that this proposal has loosened in the international community of the radiological protection, with the purpose of to familiarize to our Mexican community in radiological protection with these new concepts. (Author)

  10. Acetaminophen dosing for children

    Science.gov (United States)

    ... your child, call your provider. Proper Dosing of Suppositories If your child is vomiting or will not take oral medicine, you can use suppositories. Suppositories are placed in the anus to deliver ...

  11. Radiation dose electrophysiology procedures

    International Nuclear Information System (INIS)

    Hernandez-Armas, J.; Rodriguez, A.; Catalan, A.; Hernandez Armas, O.; Luque Japon, L.; Moral, S.; Barroso, L.; Rfuez-Hdez, R.

    2006-01-01

    The aim of this paper has been to measure and analyse some of the parameters which are directly related with the doses given to patients in two electrophysiology procedures: diagnosis and ablation with radiofrequency. 16 patients were considered in this study. 13 them had an ablation with radiofrequency at the Unit of Electrophysiology at the University Hospital of the Canaries, La Laguna., Tenerife. The results of skin doses, in the ablation cases, were higher than 2 Gy (threshold of some deterministic effects). The average value was 1.1 Gy. The personal doses, measured under the lead apron, for physician and nurses were 4 and 3 micro Sievert. These results emphasised the necessity of radiation protection measures in order to reduce, ad much as possible, the doses to patients. (Author)

  12. Dose in conventional radiography

    International Nuclear Information System (INIS)

    Acuna D, E.; Padilla R, Z. P.; Escareno J, E.; Vega C, H. R.

    2011-10-01

    It has been pointed out that medical exposures are the most significant sources of exposure to ionizing radiation for the general population. Inside the medical exposures the most important is the X-ray use for diagnosis, which is by far the largest contribution to the average dose received by the population. From all studies performed in radiology the chest radiography is the most abundant. In an X-ray machine, voltage and current are combined to obtain a good image and a reduce dose, however due to the workload in a radiology service individual dose is not monitored. In order to evaluate the dose due to chest radiography in this work a plate phantom was built according to the ISO recommendations using methylmethacrylate walls and water. The phantom was used in the Imaging department of the Zacatecas General Hospital as a radiology patient asking for a chest study; using thermoluminescent dosimeters, TLD 100 the kerma at the surface entrance was determined. (Author)

  13. Maximum permissible dose

    International Nuclear Information System (INIS)

    Anon.

    1979-01-01

    This chapter presents a historic overview of the establishment of radiation guidelines by various national and international agencies. The use of maximum permissible dose and maximum permissible body burden limits to derive working standards is discussed

  14. Irradiation dose of cosmonauts

    International Nuclear Information System (INIS)

    Makra, Zs.

    1978-01-01

    The results obtained by determining the irradiation dose during the spaceflights of Apollo as well as the Sojouz-3 and Sojouz-9 spacecrafts have been compared in the form of tables. In case of Apollo astronauts the irradiation dose was determined by two methods and its sources were also pointed out, in tables. During Sojouz spacetravels the cosmonauts were exposed to a negligible dose. In spite of this fact the radiation danger is considerable. The small irradiation doses noticed so far are due to the fact that during the spaceflights there was no big proturberance. However, during the future long-range spacetravels a better radiation shielding than the one used up to now will be necessary. (P.J.)

  15. Ibuprofen dosing for children

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000772.htm Ibuprofen dosing for children To use the sharing features ... much of this medicine can be harmful. How Ibuprofen can Help Your Child Ibuprofen is a type ...

  16. Effects of low doses

    International Nuclear Information System (INIS)

    Le Guen, B.

    2001-01-01

    Actually, even though it is comfortable for the risk management, the hypothesis of the dose-effect relationship linearity is not confirmed for any model. In particular, in the area of low dose rate delivered by low let emitters. this hypothesis is debated at the light of recent observations, notably these ones relative to the mechanisms leading to genetic instability and induction eventuality of DNA repair. The problem of strong let emitters is still to solve. (N.C.)

  17. Gonadal doses from radiotherapy

    International Nuclear Information System (INIS)

    Solomon, S.B.; Morris, N.D.

    1980-06-01

    The method of calculation of gonadal doses arising from different radiotherapeutic procedures is described. The measurement of scatter factors to the gonads from superficial and deep therapy is detailed and the analytic fits to the experimental data, as a function of field position, field size and beam energy are given. The data used to calculate the gonadal doses from treatments using linear accelerators, teletherapy and sealed sources are described and the analytic fits to the data given

  18. Proposta de um procedimento alternativo para avaliar o ofuscamento: uma abordagem temporal da direção da visão

    Directory of Open Access Journals (Sweden)

    Natalia Giraldo Vásquez

    Full Text Available Resumo O ofuscamento pode ser considerado como um dos aspectos mais complexos do processo de avaliação da iluminação natural devido a sua natureza subjetiva e às limitações nas formas de avaliação. Embora o brilho seja uma resposta subjetiva, muitos índices foram desenvolvidos para quantificar este fenômeno. Os modelos de avaliação de brilho existentes assumem usuários com direções da visão fixas, ignorando o caráter temporal/dinâmico da visão. Neste estudo, um professor foi adotado como sujeito dinâmico para a caracterização das diversas direções da visão. Sendo um trabalho experimental, os procedimentos adotados envolveram o uso de vídeo, um programa para edição de vídeo, imagens HDR e o uso do programa Photolux para o processamento das imagens. Com o valor do DGI obtido para cada direção da visão, a partir de cada posição, em todos os cenários e o tempo que o professor manteve a sua visão para cada direção, foram realizadas duas ponderações pelo tempo de permanência: DGItd (em cada direção e DGItp (em cada posição, permitindo calcular o índice total para a sala de aula. Os resultados indicaram reduções de até 30% no DGI total da sala, com relação ao DGI estático. Este estudo reforça a relevância de se incorporar a condição temporal na avaliação do ofuscamento.

  19. Proposta de modelo para dimensionamento do pessoal de enfermagem em assistência domiciliária Propuesta de modelo para la provisión de personal de enfermería en asistencia domiciliaria Proposal for a model for calculating the size of nursing staff in home care

    Directory of Open Access Journals (Sweden)

    Luiza Watanabe Dal Ben

    2007-03-01

    Full Text Available A assistência domiciliária (AD suscita questionamentos sobre a necessidade do número de horas diárias e dos dias de assistência de enfermagem por parte dos compradores da prestação de serviços à saúde em domicílio. Identificar os critérios adotados por gerentes e enfermeiras para o dimensionamento do pessoal de enfermagem. Os dados foram coletados por meio de entrevista semi-estruturada e analisados segundo o método de análise de conteúdo. Identificaram-se três categorias: elegibilidade do paciente; tempo despendido na assistência e perfil de competência do profissional. As etapas consideradas foram: identificação da carga média diária de trabalho; determinação da proporção das categorias profissionais; jornada de trabalho dos profissionais de enfermagem e identificação do índice de segurança técnica para cobertura de ausências previstas e de não previstas. Com base nessas variáveis, propusemos um modelo para calcular o quadro de profissionais de enfermagem em AD, agilizando o processo de tomada de decisão.La asistencia domiciliaria (AD suscita interrogantes sobre la necesidad del número de horas diarias y de los días de asistencia de enfermería por parte de los compradores de prestación de servicios a la salud en domicilio. Tuvo por objetivo identificar los criterios adoptados por gerentes y enfermeras para el cálculo del personal de enfermería. Los datos fueron recolectados por medio de una entrevista semi-estructurada y analizados según el método de análisis de contenido. Se identificaron tres categorías: elegibilidad del paciente, tiempo invertido en la asistencia y perfil de competencia del profesional. Las etapas consideradas fueron: identificación de la carga promedio diario de trabajo; determinación de la proporción de las categorías profesionales; jornada de trabajo de los profesionales de enfermería e identificación del índice de seguridad técnica para la cobertura de ausencias

  20. In vivo Tl dosimetry for the quality control in Radiotherapy with {sup 60} Co and brachytherapy of low dose rate; Dosimetria Tl in vivo para el control de calidad en Radioterapia con {sup 60} Co y Braquiterapia de baja tasa de dosis

    Energy Technology Data Exchange (ETDEWEB)

    Velez, G.; Bustos, S.; Balmaceda, O.; Gutierrez, S.; Ferraris, M. [Servicio de Radioterapia, Hospital San Roque. Rosario de Santa Fe 374. CP 5000. Cordoba (Argentina)

    1998-12-31

    In vivo dosimetry is used every time with more frequency as a valuable tool for the quality control in Radiotherapy. The measurements of input and output doses provide us information about the technique accuracy or the treatment procedure used; likewise the dose measurement which rectum or bladder receive in gynecologic implants contribute to the improving and adjusting the procedures in brachytherapy. Besides, it may be identify systematic errors in particular situations which allow to optimize the treatment and to minimize errors. It was realized a study at the Radiotherapy service in San Roque Hospital (Cordoba) to control the procedures used in the treatment of distinct oncologic pathologies. Its were selected patients, which were realized the routine planning with the planning system of computerized treatments Prowess 3000, that later its were controlled with In vivo thermoluminescent dosimetry using the Ceprocor Services (Cordoba). Its were realized dose skin measurements in treatments of mammary gland, pelvis, thorax, head and neck and it were measured doses in body cavities, as oral cavity, rectum, esophagus, etc. arranging the TLD inside special catheters. In the case of dose skin, the dosemeters were arranged in acrylic porta-dosemeters, at pairs, which later they were enveloped and sealed. It was founded a very good agreement among the In vivo measurements and the predicted by the planner. In some cases, the control allows to modify the treatment for to avoid over or sub dosages of the distinct organs affected by the radiation field. (Author)

  1. ParaChoice Model.

    Energy Technology Data Exchange (ETDEWEB)

    Heimer, Brandon Walter [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Levinson, Rebecca Sobel [Sandia National Lab. (SNL-CA), Livermore, CA (United States); West, Todd H. [Sandia National Lab. (SNL-CA), Livermore, CA (United States)

    2017-12-01

    Analysis with the ParaChoice model addresses three barriers from the VTO Multi-Year Program Plan: availability of alternative fuels and electric charging station infrastructure, availability of AFVs and electric drive vehicles, and consumer reluctance to purchase new technologies. In this fiscal year, we first examined the relationship between the availability of alternative fuels and station infrastructure. Specifically, we studied how electric vehicle charging infrastructure affects the ability of EVs to compete with vehicles that rely on mature, conventional petroleum-based fuels. Second, we studied how the availability of less costly AFVs promotes their representation in the LDV fleet. Third, we used ParaChoice trade space analyses to help inform which consumers are reluctant to purchase new technologies. Last, we began analysis of impacts of alternative energy technologies on Class 8 trucks to isolate those that may most efficaciously advance HDV efficiency and petroleum use reduction goals.

  2. EDUTOOL®: UN INSTRUMENTO PARA LA EVALUACIÓN Y ACREDITACIÓN DE LA CALIDAD DE LOS MOOCS

    Directory of Open Access Journals (Sweden)

    Miguel Baldomero Ramírez-Fernández

    2015-01-01

    Full Text Available Esta investigación analiza la calidad normativa de los cursos MOOCs (Massive Open Online Courses a través del instrumento EduTool®, marca registrada en la Oficina Española de Patentes y Marcas (3.087.298, en vigor. Surge de una línea de trabajo de investigación de la Universidad Pablo de Olavide (Sevilla y desarrollada en el Laboratorio de Inteligencia Computacional (LIC. EduTool® se desarrolla bajo los auspicios de la norma UNE 66181 y en el LIC se han analizado las ponderaciones de los subfactores de cada una de las dimensiones (reconocimiento de la formación, metodología de aprendizaje y niveles de accesibilidad de esta norma sobre la Gestión de la Calidad de la Formación Virtual a los MOOCs mediante lógica difusa. En este sentido, la agregación de las variables lingüísticas de 10 jueces expertos se realizó mediante la función OR probabilística y se desfuzzificaron mediante el método del centroide de área para calcular las citadas ponderaciones. Para medir la calidad de los cursos se procedió a buscar y seleccionar relevantes plataformas MOOC: Udacity, EdX, MiríadaX y Coursera. Posteriormente, por muestreo no probabilístico intencional se seleccionaron los cursos MOOCs más relevantes relativos a las categorías de informática y ciencias de la computación. Para este procedimiento de recogida de información, se habilitaron en dichas plataformas a dos ingenieros informáticos para la codificación y valoración de la calidad de estos cursos utilizando el citado instrumento. Los resultados analíticos y gráficos muestran que, de forma general, la calidad de la media de los MOOCs analizados en cada plataforma se sitúa por encima de la puntuación que describe el mínimo exigido (50 %. Así pues, se apreció una calidad media superior en las plataformas Coursera (66,34 % y EdX (62,62 %, intermedia en la plataforma Udacity (54,92 % y algo inferior en la plataforma MiríadaX (50,40 %.

  3. Universidades accesibles para todos

    Directory of Open Access Journals (Sweden)

    Roxana Stupp Kupiec

    2001-01-01

    Full Text Available Este trabajo pretende hacer conciencia sobrelos factores que inciden en la construcción colectiva deuniversidades dispuestas a innovar y transformar suideología, sus políticas, el currículum, los servicios estu-diantiles, la infraestructura física y administrativa y lasestrategias de comunicación e información, bajo el para-digma de la accesibilidad en el entorno. Se hace referen-cia al marco legal internacional y nacional que orientalas acciones que deben planificarse e implementarse enlas instituciones de Educación Superior.En la construcción de universidades accesibles para to-dos se requiere de un cambio en la concepción curricu-lar. Se analizan conceptos como la flexibilidad en la for-mación y el acceso a los planes de estudio para respondera las necesidades educativas de todos los estudiantes. Para promover estas transformaciones se proponen prin-cipios y prácticas tales como la interdisciplinareidad y lainclusión del tema de la discapacidad en todas las carre-ras. Además, se presentan ejemplos de aplicación en dife-rentes áreas del perfil profesional, en la formación deldocente universitario y en actividades de proyección so-cial, vida estudiantil e investigación. En el ámbito estu-diantil, se describen algunos servicios y procesos que sehan desarrollado en la Universidad de Costa Rica

  4. Educando para la ignorancia

    Directory of Open Access Journals (Sweden)

    Miguel Durán

    1996-06-01

    Full Text Available Más que describir una situación particular, los autores buscan con este escrito motivar al estudiante para que asuma posiciones críticas; así como dar un campanazo de alerta a los profesores, en relación a los conocimientos que transmiten a sus alumnos y la forma en que lo hacen; todo con el ánimo de generar verdaderos espacios de reflexión en la universidad.

  5. Using a field radiometer to estimate instantaneous sky clearness Radiômetro de campo para cálculo da clareza instantânea do céu

    Directory of Open Access Journals (Sweden)

    Eduardo G. Souza

    2006-06-01

    Full Text Available Reflectance measurements of crop plants and canopies show promise for guiding within-season, variable-rate nitrogen (N application. Most research results have been obtained around solar noon with clear skies. However, for practical application, the system must work under cloudy skies or away from solar noon. The objective of this work was to assess the effect of cloud conditions on reflectance measurements of a corn canopy. The approach was to estimate an instantaneous sky clearness index (ICI which could be used to correct field radiometer data for variations in cloud cover, such that the same reflectance reading would be obtained (and the same N recommendation made for the same plants regardless of cloud conditions. Readings were taken from morning until night over 11 days with a range of sky conditions (sunny, overcast, partly cloudy. Data from clear days were used to estimate the theoretical expected spectral global radiation incident on a horizontal surface. The ICI was calculated as the ratio between the actual spectral global radiation and the corresponding theoretical global radiation. Analysis of the ICI for each band showed that the influence of cloudiness was different for each band. Thus, the cloud effect could not be compensated by the use of a band ratio or vegetation index.Medidas da reflectância das folhas das plantas mostram-se promissoras para a aplicação de nitrogênio a taxa variável; entretanto, a maioria dos resultados de pesquisa foi obtida ao redor do meio-dia solar e com céu aberto, porém para aplicações práticas um sistema tem que trabalhar debaixo de céu nublado e fora do meio-dia solar. O objetivo deste trabalho foi avaliar o efeito de condições de nuvem em medidas de reflectância de milho. A abordagem foi calcular um índice instantâneo de clareza do céu (ICI que pode ser usado para corrigir dados de radiômetros de campo para variações em cobertura de nuvem, tal que essas reflectâncias seriam

  6. INICIATIVAS PARA EL CAMBIO

    Directory of Open Access Journals (Sweden)

    César Alfonso Defrancisco-Larrañaga

    2013-07-01

    Full Text Available El planeta no atraviesa por su mejor momento en materia de conservación y renovación de sus recursos naturales. Claramente en los últimos tiempos los recursos hídricos han venido haciéndose cada vez menores; el hombre ha notado con preocupación y vivido en carne propia este fenómeno, que de no ser tratado a tiempo, podría atentar contra la existencia misma. Esto lo ha alentado a buscar métodos que sirvan como solución para contrarrestar éste mal y crear conciencia entre sus iguales, para así poder garantizar su permanencia y la de su entorno durante muchas generaciones. En países desarrollados del continente europeo y en algunos lugares de América del norte, el uso de sistemas de reutilización y tratamiento de aguas grises y aprovechamiento de las aguas lluvias se ha convertido en una constante y nos están dando las pautas para poder seguir el ejemplo y así de esta manera poder aportar a la causa ambiental y a su vez crear un ahorro en nuestros gastos mensuales de consumo.

  7. Dosimetric contribution of organs of biokinetics of {sup 99m}Tc and {sup 123}I to estimate radiation doses in thyroids of children of 1 and 5 years; Contribucion dosimetrica de organos de la biocinetica del {sup 99m}Tc y {sup 123}I para estimar dosis en tiroides de ninos de 1 y 5 anos

    Energy Technology Data Exchange (ETDEWEB)

    Vasquez, M.V.; Castillo, C.E.; Abanto, D.M.; Rocha, D.; Garcia, W.H.; Marin, K., E-mail: marvva@hotmail.com [Universidad Nacional de Trujillo (UNT), Trujillo (Peru); Quispe, R. [Centro de Ciencias Aplicadas y Desarrollo Tecnologico, UNAM, Mexico (Mexico)

    2015-07-01

    The absorbed doses by thyroids during uptake studies through biokinetics of radiopharmaceuticals containing {sup 123}I (iodine) or {sup 99m}Tc (pertechnetate) are estimated. Using the MIRD scheme and the representation of Cristy-Eckerman for thyroids in children of 1 and 5 years, the objective of the study was to determine whether the dosimetric biokinetic contributions of the organs of {sup 123}I (iodide) and {sup 99m}Tc (pertechnetate) biokinetic are significant in the estimated of the absorbed dose for thyroid uptake studies.

  8. Blind method of clustering for the evaluation of the dose received by personnel in two methods of administration of radiopharmaceuticals; Metodo ciego de clusterizacion para la evaluacion de la dosis recibida por el personal en dos metodos de administracion de radioformacos

    Energy Technology Data Exchange (ETDEWEB)

    VerdeVelasco, J. M.; Gonzalez Gonzalez, M.; Montes Fuentes, C.; Verde Velasco, J.; Gonzalez Blanco, F. J.; Ramos Pacho, J. A.

    2013-07-01

    The difficulty for the injection of drugs marked with radioactive isotopes while syringe is located within the lead protector does that in many cases staff do it chooses to use the syringe outside the lead protector, increasing therefore the dose of radiation received. In our service raises the possibility of using a different methodology, channeling a pathway through a catheter, which allows administer, in all cases, with the syringe within the lead guard. We will check if significant differences can be seen both in the dose absorbed by the staff as in the time it takes to perform the administration of the drug using the method proposed compared injection without guard. (Author)

  9. Assessment of internal doses

    CERN Document Server

    Rahola, T; Falk, R; Isaksson, M; Skuterud, L

    2002-01-01

    There is a definite need for training in dose calculation. Our first course was successful and was followed by a second, both courses were fully booked. An example of new tools for software products for bioassay analysis and internal dose assessment is the Integrated Modules for Bioassay Analysis (IMBA) were demonstrated at the second course. This suite of quality assured code modules have been adopted in the UK as the standard for regulatory assessment purposes. The intercomparison measurements are an important part of the Quality Assurance work. In what is known as the sup O utside workers ' directive it is stated that the internal dose measurements shall be included in the European Unions supervision system for radiation protection. The emergency preparedness regarding internal contamination was much improved by the training with and calibration of handheld instruments from participants' laboratories. More improvement will be gained with the handbook giving practical instructions on what to do in case of e...

  10. Mean inactivation dose (D)

    International Nuclear Information System (INIS)

    Vijayakumar, S.; Ng, T.C.; Raudkivi, U.; Meaney, T.J.

    1990-01-01

    By predicting treatment outcome to radiotherapy from in vitro radiobiological parameters, not only individual patient treatments can be tailored, but also new promising treatment protocols can be tried in patients in whom unfavorable outcome is predicted. In this respect, choosing the right parameter can be very important. Unlike D 0 and N which provide information of the distal part of the survival curve, mean inactivation dose (D) estimates overall radiosensitivity. However, the parameters reflecting the response at the clinically relevant low-dose region are neglected in the literature. In a literature survey of 98 papers in which survival curves or D 0 /N were used, only in 2 D was used. In 21 papers the D 0 /n values were important in drawing conclusions. By calculating D in 3 of these 21 papers, we show that the conclusion drawn may be altered with the use of D. The importance of ''low-dose-region-parameters'' is reviewed. (orig.)

  11. Dose Reduction Techniques

    International Nuclear Information System (INIS)

    WAGGONER, L.O.

    2000-01-01

    As radiation safety specialists, one of the things we are required to do is evaluate tools, equipment, materials and work practices and decide whether the use of these products or work practices will reduce radiation dose or risk to the environment. There is a tendency for many workers that work with radioactive material to accomplish radiological work the same way they have always done it rather than look for new technology or change their work practices. New technology is being developed all the time that can make radiological work easier and result in less radiation dose to the worker or reduce the possibility that contamination will be spread to the environment. As we discuss the various tools and techniques that reduce radiation dose, keep in mind that the radiological controls should be reasonable. We can not always get the dose to zero, so we must try to accomplish the work efficiently and cost-effectively. There are times we may have to accept there is only so much you can do. The goal is to do the smart things that protect the worker but do not hinder him while the task is being accomplished. In addition, we should not demand that large amounts of money be spent for equipment that has marginal value in order to save a few millirem. We have broken the handout into sections that should simplify the presentation. Time, distance, shielding, and source reduction are methods used to reduce dose and are covered in Part I on work execution. We then look at operational considerations, radiological design parameters, and discuss the characteristics of personnel who deal with ALARA. This handout should give you an overview of what it takes to have an effective dose reduction program

  12. CT dose management

    International Nuclear Information System (INIS)

    Zasheva, Ts.; Georgiev, E.; Kirova, G.

    2013-01-01

    Full text: Introduction: In recent decades Computed Tomography established itself as one of the most common study with a very wide range of applications and techniques of scanning. Best diagnostic value of the method resist to the risks of ionizing radiation, as statistics show that CT is one of the main sources of continuously increasing dose to the population. What you will learn: The physical parameters of the X-ray tube and the principles of image reconstruction; The relationship between variables parameters and the received dose; The ratio between the force and voltage of the current to the image quality, Influence of the used contrast medium to the physical properties of the image, The ratio of patient BMI to image processing, Effective use of knowledge for the optimal CT protocol. Discussions: The goal to reduce the dose received by the patient during a CT scan while keeping the diagnostic quality of the image puts to the test as handset X-ray producers and technicians who need to master the technique of study protocol forming as well as to balance the harm - benefit ratio. Among the most popular techniques are these of dose modulation, low-dose computed tomography at the expense of a reduction of the current or voltage intensity, and control of the number of post-processing algorithms for the image reconstruction. Conclusion: The training of radiologists and X-ray technicians plays a major role in optimizing of technical parameters in view of the reduction of the dose for the patient, while maintaining the diagnostic quality of the image

  13. Dose Reduction Techniques

    Energy Technology Data Exchange (ETDEWEB)

    WAGGONER, L.O.

    2000-05-16

    As radiation safety specialists, one of the things we are required to do is evaluate tools, equipment, materials and work practices and decide whether the use of these products or work practices will reduce radiation dose or risk to the environment. There is a tendency for many workers that work with radioactive material to accomplish radiological work the same way they have always done it rather than look for new technology or change their work practices. New technology is being developed all the time that can make radiological work easier and result in less radiation dose to the worker or reduce the possibility that contamination will be spread to the environment. As we discuss the various tools and techniques that reduce radiation dose, keep in mind that the radiological controls should be reasonable. We can not always get the dose to zero, so we must try to accomplish the work efficiently and cost-effectively. There are times we may have to accept there is only so much you can do. The goal is to do the smart things that protect the worker but do not hinder him while the task is being accomplished. In addition, we should not demand that large amounts of money be spent for equipment that has marginal value in order to save a few millirem. We have broken the handout into sections that should simplify the presentation. Time, distance, shielding, and source reduction are methods used to reduce dose and are covered in Part I on work execution. We then look at operational considerations, radiological design parameters, and discuss the characteristics of personnel who deal with ALARA. This handout should give you an overview of what it takes to have an effective dose reduction program.

  14. Radioactive cloud dose calculations

    International Nuclear Information System (INIS)

    Healy, J.W.

    1984-01-01

    Radiological dosage principles, as well as methods for calculating external and internal dose rates, following dispersion and deposition of radioactive materials in the atmosphere are described. Emphasis has been placed on analytical solutions that are appropriate for hand calculations. In addition, the methods for calculating dose rates from ingestion are discussed. A brief description of several computer programs are included for information on radionuclides. There has been no attempt to be comprehensive, and only a sampling of programs has been selected to illustrate the variety available

  15. Use of low doses of cobalt 60 gamma radiation on beet (Beta vulgaris L.), carrot (Daucus carota L.) and radish (Raphanus sativus L.) seed to stimulate increase yield; Emprego da radiacao gama do cobalto 60 em sementes de beterraba (Beta vulgaris L.), cenoura (Daucus carota L.) e rabanete (Raphanus sativus L.) para estimular o aumento da producao

    Energy Technology Data Exchange (ETDEWEB)

    Bovi, Jose Eduardo

    2000-07-01

    The research had the aim of evaluating the effects of low doses of Cobalt-60 gamma radiation on seeds of radish (Raphanus sativus L.) cultiva Champion, cultivars Nantes Forto (european origin) and Brasilia (Rio Grande do Sul origin) carrot (Daucus carota L. var. sativus (Hoffm.) Thell), and red beet (Beta vulgaris L.) cultivar Tall Top Early Wonder before sowing, its effects on plant growth, on the yield and roots storage of two tillages: with sowing in the same day of radiation and six days after radiation seeds. The data showed that the seeds radiation did not interfered negatively on plants growth, and the species presented differences as roots production and doses on both plantation: radish with 5,0 Gy and 2,5 Gy doses respectively to the first and the second sowings, Brasilia carrot with 2,5 Gy dose to both sowings. Nantes carrot with 2,5 Gy and 5,0 Gy respectively to the first and the second sowings, and beet with 7,5 Gy and 5,0 Gy respectively to the first and the second plantations. There is not statistics difference by Tukey test (5% and 1%) and none relation between seeds radiation and loss weight on roots storage. (author)

  16. Flexión de Una Barra Delgada Empotrada en un Extremo: Aproximación para Pequeñas Pendientes

    Directory of Open Access Journals (Sweden)

    Beléndez Tarsicio

    2002-01-01

    Full Text Available En los cursos de Física y Mecánica para estudiantes universitarios de Ciencias e Ingeniería, y dentro del tema dedicado a la elasticidad, se estudian los sólidos deformables, asícomo los fenómenos de tracción, compresión, cizalladura, torsión, exión y pandeo. En el caso de la exión uno de los ejemplos que suele analizarse es el de una barra delgada empotrada en un extremo sobre la que actúa una fuerza concentrada vertical en el extremo libre. El estudio se hace para pequeños desplazamientos o pequeñas pendientes de la barra, lo que permite integrar fácilmente la ecuación diferencial de la barra exionada y calcular la elástica y la echa o desplazamiento vertical del extremo libre. Sin embargo, la aproximación para pequeñas pendientes que se hace en la bibliografía es incompatible con otra consideración que siempre se tiene en cuenta y es que la longitud de la fibra neutra de la barra no cambia cuando la barra exiona. En este trabajo se presenta, para al problema de la exión de una barra delgada en voladizo, una aproximación para pequeños desplazamientos o pequeñas pendientes de la barra menos aproximada de lo común". Para ello se introduce como hipótesis la constancia de la longitud de la fibra neutra de la barra lo que permite obtener unas ecuaciones más precisas que las que aparecen en la bibliografía. Los resultados obtenidos se han comparado con los exactos asícomo con las medidas experimentales realizadas en el laboratorio con una regla de acero empotrada en un extremo. Las ecuaciones de la elástica se obtienen siguiendo un tratamiento análogo al desarrollado por Feynman cuando estudia la viga exionada en su libro de Física, por lo que el desarrollo aquípresentado puede ser seguido sin muchos problemas por cualquier estudiante de Física o Mecánica de los primeros cursos universitarios.

  17. Estimation of the contribution by neutrons to the equivalent dose for exposed occupationally personnel and people in medical use facilities: X rays of equal or superior energy to 10 MV; Estimacion de la contribucion por neutrones a la dosis equivalente para personal ocupacionalmente expuesto y publico en instalaciones de uso medico: rayos X de energia igual y/o superior a 10 MV

    Energy Technology Data Exchange (ETDEWEB)

    Ortega J, R.; Reyes S, M. A. [Comision Nacional de Seguridad Nuclear y Salvaguardias, Dr. Jose Ma. Barragan 779, Col. Narvarte, 03020 Mexico D. F. (Mexico); Moranchel y R, M., E-mail: rojimenez@cnsns.gob.mx [IPN, Escuela Superior de Fisica y Matematicas, Departamento de Ingenieria Nuclear, Av. Instituto Politecnico Nacional s/n, U. P. Adolfo Lopez Mateos, Edif. 9, Col. San Pedro Zacatenco, 07738 Mexico D. F. (Mexico)

    2013-10-15

    In Mexico the use of electron accelerators for treating cancerous tumors had grown enormously in the last decade. When the treatments are carried out with X-ray beam energy below 10 MV the design of the shielding of the radioactive facility is determined by analyzing the interaction of X-rays, which have a direct impact and dispersion, with materials of the facility. However, when it makes use of X-ray beam energy equal to or greater than 10 MV the neutrons presence is imminent due to their generation by the interaction of the primary beam X-ray with materials head of the accelerator and of the table of treatment, mainly. In these cases, the design and calculation of shielding considers the generation of high-energy neutrons which contribute the equivalent dose that public and occupationally staff exposed (POE) will receive in the areas surrounding the facility radioactive. However, very few measurements have been performed to determine the actual contribution to the neutron dose equivalent received by POE and public during working hours. This paper presents and estimate of the actual contribution of the neutron dose equivalent received by public and POE facilities in various radioactive medical use, considering many factors. To this end, measurements were made of the equivalent dose by using a neutron monitor in areas surrounding different radioactive installations (of Mexico) which used electron accelerators medical use during treatment with X-ray beam energy equal to or greater than 10 MV. The results are presented after a statistical analysis of a wide range of measures in order to estimate more reliability real contribution of the neutron dose equivalent for POE and the public. (author)

  18. Estimation of the contribution of neutrons to the equivalent dose for personnel occupationally exposed and public in medical facilities: X-ray with energy equal or greater than 10MV; Estimacion de la contribucion por neutrones a la dosis equivalente para personal ocupacionalmente expuesto y publico en instalaciones de uso medico: rayos X de energia igual y/o superior a 10MV

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, Alfonso Mayer; Jimenez, Roberto Ortega; Sanchez, Mario A. Reyes, E-mail: amgesfm@hotmail.com, E-mail: rojimenez@cnsns.gob.mx [Comision Nacional de Seguridad Nuclear y Salvaguardias (CNSNS), Mexico, D.F. (Mexico); Moranchel y Mejia, Mario, E-mail: mmoranchel@ipn.mx [Instituto Politecnico Nacional (ESFM/IPN), Mexico, D.F. (Mexico). Escuela Superior de Fisica y Matematicas. Departamento de lngenieria Nuclear

    2013-07-01

    In Mexico the use of electron accelerators for treating cancerous tumors had grown enormously in the last decade. When the treatments are carried out with X-ray beam energy below 10 MV the design of the shielding of the radioactive facility is determined by analyzing the interaction of X-rays, which have a direct impact and dispersion, with materials of the facility. However, when it makes use of X-ray beam energy equal to or greater than 10 MV the neutrons presence is imminent due to their generation by the interaction of the primary beam X-ray with materials head of the accelerator and of the table of treatment, mainly. In these cases, the design and calculation of shielding considers the generation of high-energy neutrons which contribute the equivalent dose that public and Occupationally Staff Exposed (POE) will receive in the areas surrounding the facility radioactive. However, very few measurements have been performed to determine the actual contribution to the neutron dose equivalent received by POE and public during working hours. This paper presents an estimate of the actual contribution of the neutron dose equivalent received by public and POE facilities in various radioactive medical use, considering many factors. To this end, measurements were made of the equivalent dose by using a neutron monitor in areas surrounding different radioactive installations (of Mexico) which used electron accelerators medical use during treatment with X-ray beam energy equal to or greater than 10 MV. The results are presented after a statistical analysis of a wide range of measures in order to estimate more reliability real contribution of the neutron dose equivalent for POE and the public. (author)

  19. Fertilizer micro-dosing

    International Development Research Centre (IDRC) Digital Library (Canada)

    Localized application of small quantities of fertilizer (micro-dosing), combined with improved planting pits for rainwater harvesting, has generated greater profits and food security for women farmers in the Sahel. • Women are 25% more likely to use combined applications, and have expanded areas of food crops (cowpea,.

  20. Weldon Spring dose calculations

    International Nuclear Information System (INIS)

    Dickson, H.W.; Hill, G.S.; Perdue, P.T.

    1978-09-01

    In response to a request by the Oak Ridge Operations (ORO) Office of the Department of Energy (DOE) for assistance to the Department of the Army (DA) on the decommissioning of the Weldon Spring Chemical Plant, the Health and Safety Research Division of the Oak Ridge National Laboratory (ORNL) performed limited dose assessment calculations for that site. Based upon radiological measurements from a number of soil samples analyzed by ORNL and from previously acquired radiological data for the Weldon Spring site, source terms were derived to calculate radiation doses for three specific site scenarios. These three hypothetical scenarios are: a wildlife refuge for hunting, fishing, and general outdoor recreation; a school with 40 hr per week occupancy by students and a custodian; and a truck farm producing fruits, vegetables, meat, and dairy products which may be consumed on site. Radiation doses are reported for each of these scenarios both for measured uranium daughter equilibrium ratios and for assumed secular equilibrium. Doses are lower for the nonequilibrium case

  1. Low dose epidemiologic studies

    International Nuclear Information System (INIS)

    Anon.

    1990-01-01

    In this chapter the BEIR committee has reviewed low-dose irradiation studies since the BEIR III report. They have considered the carcinogenic effectiveness of low-LET in populations exposed to radiation from a number of different sources: diagnostic radiography; fallout from nuclear weapons testing; nuclear installations; radiation in the workplace and high levels of natural background radiation

  2. Radiation doses to Finns

    International Nuclear Information System (INIS)

    Rantalainen, L.

    1996-01-01

    The estimated annual radiation doses to Finns have been reduced in the recent years without any change in the actual radiation environment. This is because the radiation types have been changed. The risk factors will probably be changed again in the future, because recent studies show discrepancies in the neutron dosimetry concerning the city of Hiroshima. Neutron dosimetry discrepancy has been found between the predicted and estimated neutron radiation. The prediction of neutron radiation is calculated by Monte Carlo simulations, which have also been used when designing recommendations for the limits of radiation doses (ICRP60). Estimation of the neutron radiation is made on the basis of measured neutron activation of materials in the city. The estimated neutron dose beyond 1 km is two to ten, or more, times as high as the predicted dose. This discrepancy is important, because the most relevant distances with respect to radiation risk evaluation are between 1 and 2 km. Because of this discrepancy, the present radiation risk factors for gamma and neutron radiation, which rely on the Monte Carlo calculations, are false, too. The recommendations of ICRP60 have been adopted in a few countries, including Finland, and they affect the planned common limits of the EU. It is questionable whether happiness is increased by adopting false limits, even if they are common. (orig.) (2 figs., 1 tab.)

  3. Dose Reduction Techniques

    CERN Document Server

    Waggoner, L O

    2000-01-01

    As radiation safety specialists, one of the things we are required to do is evaluate tools, equipment, materials and work practices and decide whether the use of these products or work practices will reduce radiation dose or risk to the environment. There is a tendency for many workers that work with radioactive material to accomplish radiological work the same way they have always done it rather than look for new technology or change their work practices. New technology is being developed all the time that can make radiological work easier and result in less radiation dose to the worker or reduce the possibility that contamination will be spread to the environment. As we discuss the various tools and techniques that reduce radiation dose, keep in mind that the radiological controls should be reasonable. We can not always get the dose to zero, so we must try to accomplish the work efficiently and cost-effectively. There are times we may have to accept there is only so much you can do. The goal is to do the sm...

  4. Distribuciones simuladas de valores de d13c de colágeno humano: implicancias para los estudios paleodietarios

    Directory of Open Access Journals (Sweden)

    Barrientos, Gustavo

    2005-01-01

    Full Text Available El objetivo de este trabajo es presentar los primeros resultados derivados de la aplicación de un programa de simulación de distribuciones de valores de δ13C de colágeno humano (DeltaCarb130.0, desarrollado por los autores. DeltaCarb130.0 es un programa simple que simula la composición isotópica (δ13C del colágeno de huesos humanos obtenida a través de una dieta de composición variable, constituida por tres ingestas diarias, durante un período de 1825 días (5 años. La composición de la dieta y los valores de δ13C de cada recurso dietario (vegetales C3 y C4, carne de herbívoros consumidores de C3 y C4, de mamíferos marinos, de peces y moluscos se obtienen, en cada etapa de la simulación, a través de un proceso aleatorio a partir de datos de abundancia relativa y rangos de valores de δ13C de cada tipo de recurso. Se analizarán estadísticamente las distribuciones de valores de δ13C obtenidas a partir de n corridas del programa para cada combinación dietaria, con la finalidad de obtener medidas de tendencia central y de dispersión asociadas a cada tipo de dieta y calcular la probabilidad de obtener valores "outliers", un rasgo frecuente en el estudio de casos arqueológicos.

  5. Dose tracking and dose auditing in a comprehensive computed tomography dose-reduction program.

    Science.gov (United States)

    Duong, Phuong-Anh; Little, Brent P

    2014-08-01

    Implementation of a comprehensive computed tomography (CT) radiation dose-reduction program is a complex undertaking, requiring an assessment of baseline doses, an understanding of dose-saving techniques, and an ongoing appraisal of results. We describe the role of dose tracking in planning and executing a dose-reduction program and discuss the use of the American College of Radiology CT Dose Index Registry at our institution. We review the basics of dose-related CT scan parameters, the components of the dose report, and the dose-reduction techniques, showing how an understanding of each technique is important in effective auditing of "outlier" doses identified by dose tracking. Copyright © 2014 Elsevier Inc. All rights reserved.

  6. When is a dose not a dose?

    International Nuclear Information System (INIS)

    Bond, V.P.

    1991-01-01

    Although an enormous amount of progress has been made in the fields of radiation protection and risk assessment, a number of significant problems remain. The one problem which transcends all the rest, and which has been subject to considerable misunderstanding, involves what has come to be known as the 'linear non-threshold hypothesis', or 'linear hypothesis'. Particularly troublesome has been the interpretation that any amount of radiation can cause an increase in the excess incidence of cancer. The linear hypothesis has dominated radiation protection philosophy for more than three decades, with enormous financial, societal and political impacts and has engendered an almost morbid fear of low-level exposure to ionizing radiation in large segments of the population. This document presents a different interpretation of the linear hypothesis. The basis for this view lies in the evolution of dose-response functions, particularly with respect to their use initially in the context of early acute effects, and then for the late effects, carcinogenesis and mutagenesis. 11 refs., 4 figs

  7. para mejorar el %R

    Directory of Open Access Journals (Sweden)

    Alfredo Díaz Mata

    2001-01-01

    Full Text Available En este trabajo se revisan dos indicadores técnicos bursátiles que están estrechamente relacionados, el oscilador estocástico %K de Lane y el oscilador %R de Williams; asimismo, se evalúa el uso de dos mecanismos asociados con el primero y que no suelen utilizarse con el %R: el proceso de frenado (slowing y el uso de un promedio móvil del propio oscilador estocástico como disparadores de señales de compra y de venta. Realizando simulaciones con 27 acciones y el Índice de Precios y Cotizaciones de la Bolsa Mexicana de Valores se verifica la hipótesis principal y se comprueba que, efectivamente, en muchos casos, el uso del proceso de frenado con el oscilador %R de Williams permite tomar mejores decisiones. Por otro lado, se concluye que de los dos disparadores de señales el que mejor funciona, tanto para %K como para %R es el uso de cotas inferior y superior. Este artículo surgió en el curso de una investigación sobre el análisis técnico bursátil de acciones que se puede realizar en su totalidad por computadora y que, esencialmente, excluye el análisis gráfico. Uno de los propósitos del estudio es determinar si es posible, y bajo qué mecanismos, establecer un sistema de análisis bursátil que le permita al inversionista tomar decisiones de inversión en acciones en la Bolsa Mexicana de Valores sin tener que emplear la considerable cantidad de tiempo que es necesario para el análisis gráfico tradicional. Durante este estudio se realizó un análisis preliminar de unos 120 indicadores técnicos para, por un lado, conocerlos con cierto detalle y, por otra parte, aislar aquellos que prometían ser de utilidad para el objetivo de la investigación. Fue en este proceso cuando se detectó que existen dos indicadores que están relacionados y que permiten un análisis por separado que tiene, cuando menos, dos ventajas. En primer lugar está el placer que da a quien gusta de estos temas encontrarse con indicadores que, de acuerdo

  8. Dose specification for radiation therapy: dose to water or dose to medium?

    International Nuclear Information System (INIS)

    Ma, C-M; Li Jinsheng

    2011-01-01

    The Monte Carlo method enables accurate dose calculation for radiation therapy treatment planning and has been implemented in some commercial treatment planning systems. Unlike conventional dose calculation algorithms that provide patient dose information in terms of dose to water with variable electron density, the Monte Carlo method calculates the energy deposition in different media and expresses dose to a medium. This paper discusses the differences in dose calculated using water with different electron densities and that calculated for different biological media and the clinical issues on dose specification including dose prescription and plan evaluation using dose to water and dose to medium. We will demonstrate that conventional photon dose calculation algorithms compute doses similar to those simulated by Monte Carlo using water with different electron densities, which are close (<4% differences) to doses to media but significantly different (up to 11%) from doses to water converted from doses to media following American Association of Physicists in Medicine (AAPM) Task Group 105 recommendations. Our results suggest that for consistency with previous radiation therapy experience Monte Carlo photon algorithms report dose to medium for radiotherapy dose prescription, treatment plan evaluation and treatment outcome analysis.

  9. Inmunopotenciadores para la acuicultura

    Directory of Open Access Journals (Sweden)

    Rocmira Pérez

    2014-04-01

    Full Text Available La acuicultura es una de las actividades económicas de mayor crecimiento para la producción de alimentos. Uno de sus principales retos es la obtención de grandes volúmenes de producción con la mayor calidad posible. Esto conlleva a una reducción de la aplicación de antibióticos y productos quimioterapéuticos. Una de las estrategias más prometedoras es la aplicación de inmunopotenciadores, principalmente en los cultivos intensivos. El objetivo de este trabajo fue revisar los principales inmunopotenciadores, así como las tendencias y retos de su uso mundial. Se resumen las particularidades moleculares y funcionales de los mismos y se hace énfasis en los más estudiados: levamisol, ß-glucanos, lipopolisacárido, vitamina C, extractos de plantas y hormonas. Todos estos compuestos de naturaleza heterogénea inciden mayoritariamente en los componentes de la inmunidad innata de los peces, fortaleciendo y potenciando la resistencia a enfermedades; adicionalmente algunos de ellos tienen funciones antiestrés y favorecen su crecimiento. Se concluye que los inmunopotenciadores constituyen una estrategia viable para reducir las pérdidas por problemas sanitarios en el sector de la acuicultura; pero aún quedan por solucionar aspectos como la vía de administración y la etapa de inmunización adecuada para cada especie y tipo de cultivo.

  10. Desarrollo de un modelo matemático de diferencias finitas para el análisis del campo de temperaturas en la soldadura por arco de chapas finas de acero inoxidable

    Directory of Open Access Journals (Sweden)

    Miguel, V.

    2010-12-01

    Full Text Available This work develops a finite difference method to evaluate the temperature field in the heat affected zone in butt welding applied to AISI 304 stainless steel thin sheet by GTAWprocess. A computer program has been developed and implemented by Visual Basic for Applications (VBA in MS-Excel spreadsheet. The results that are obtained using the numerical application foresee the thermal behaviour of arc welding processes. An experimental methodology has been developed to validate the mathematical model that allows to measure the temperature in several points close to the weld bead. The methodology is applied to a stainless steel sheet with a thickness lower than 3 mm, although may be used for other steels and welding processes as MIG/MAG and SMAW. The data which has been obtained from the experimental procedure have been used to validate the results that have been calculated by the finite differences numerical method. The mathematical model adjustment has been carried out taking into account the experimental results. The differences found between the experimental and theoretical approaches are due to the convection and radiation heat losses, which have not been considered in the simulation model.With this simple model, the designer will be able to calculate the thermal cycles that take place in the process as well as to predict the temperature field in the proximity of the weld bead.

    En este trabajo se desarrolla un método de diferencias finitas para calcular el campo de temperaturas en la zona afectada por el calor en la soldadura de dos chapas de acero inoxidable AISI 304, soldadas mediante el procedimiento GTAW. Se ha desarrollado un programa informático implementado en libros de cálculo MS-Excel con Visual Basic para Aplicaciones (VBA. Los experimentos modelizados a través de la aplicación numérica predicen el comportamiento térmico de un procedimiento de soldadura. Para la validación del modelo matemático se ha desarrollado un

  11. Ha vuelto para mirarnos

    OpenAIRE

    Casalderrey, Francisco

    2008-01-01

    En cada entrega analizaremos un cuadro, mirándolo con ojos matemáticos. Con esa particular mirada, fruto de nuestra propia (de)formación. Y desde ese punto de vista haremos paseos por el arte y las matemáticas. Espero que el lector, como hago yo mismo, disfrute descubriendo más allá de lo que a simple vista distinguiría cualquiera. Al fin de cuentas, el arte, como las matemáticas, han sido creados para hacernos disfrutar.

  12. Interfaces para control cerebral

    OpenAIRE

    Spinelli, Enrique Mario

    2000-01-01

    La función de una interfaz para control cerebral basada en señales de electroencefalograma (EEG), en forma general denominada BCI (Brain control Interface), es establecer un enlace directo entre el cerebro y una máquina, sin utilizar acciones motoras directas. Una BCI permite realizar operaciones simples a partir de la interpretación de las señales de EEG. Su desarrollo está principalmente orientado hacia la ayuda a personas con discapacidades motoras severas, que poseen deterioros en el sist...

  13. Comunicar para la salud

    Directory of Open Access Journals (Sweden)

    Lic. Eva Bocco

    1998-01-01

    Full Text Available Con este trabajo quiero plantearles una inquietud en torno al rol que nos cabe a los comunicadores en el área de la salud desde la perspectiva de la comunicación para la salud. ¿Se puede pensar la salud pública desvinculada de la comunicación? ¿La comunicación es posible sin la existencia de salud en la comunidad? ¿Qué puede hacer un comunicador en el ministerio de salud? ¿Puede un estado desarrollar políticas de salud sin la presencia de la comunicación?

  14. Democracia para ciudadanos ciborgs

    Directory of Open Access Journals (Sweden)

    Juan Varela

    2007-07-01

    Full Text Available Enumera los instrumentos imprescindibles de la ciberpolítica para campañas electorales en España, cuando se renovaron los cargos municipales. La política vuelve a ser personal cuando ciudadanos y políticos se hablan cara a cara y cita varios ejemplos, reconociendo la recuperación de la comunicación directa. La ciberdemocracia es muy exigente. Los políticos prefieren la magia de la imagen. La sociedad no sabe como detener la propaganda viral que bombardea a los buscadores de red.

  15. Democracia para ciudadanos ciborgs

    OpenAIRE

    Juan Varela

    2007-01-01

    Enumera los instrumentos imprescindibles de la ciberpolítica para campañas electorales en España, cuando se renovaron los cargos municipales. La política vuelve a ser personal cuando ciudadanos y políticos se hablan cara a cara y cita varios ejemplos, reconociendo la recuperación de la comunicación directa. La ciberdemocracia es muy exigente. Los políticos prefieren la magia de la imagen. La sociedad no sabe como detener la propaganda viral que bombardea a los buscadores de red.

  16. The Hanford Emergency Dosimetry System; Le Systeme de Dosimetrie pour les Cas d'Urgence a Hanford; 0421 0418 0421 0422 0414 ; El Sistema Dosimetrico de Hanford para Casos de Urgencia

    Energy Technology Data Exchange (ETDEWEB)

    Larson, H. V.; Keene, A. R. [Radiation Protection Operation, Hanford Laboratories, General Electric Company, Hanford Atomic Products Operation, Richland, WA (United States)

    1965-06-15

    dosimetros contienen laminas de los mismos elementos que el dosimetro de pelicula y constituyen un medio mas para calcular la dosis individual. (author) [Russian] Proekt v Hjenforde predstavljaet soboj bol'shoj atomnyj promyshlennyj kompleks, v kotoryj vhodjat jadernye reaktory, zavody po proizvodstvu teplovydeljajushhih jelementov, ustanovki dlja himicheskogo razdelenija i issledovatel'skie laboratorii. V dopolnenie k programme nabljudenija i kontrolirovanija radiacionnogo obluchenija personala razrabotana sistema avarijnogo dozimetricheskogo kontrolja s cel'ju obespechenija bystroj ocenki bol'shih doz, provedenija otbora sluzhashhih i kontrolja nad nimi, preduprezhdenija personala i sozdanija centrov avarijnogo kontrolja personala, ocenki vneshnih doz obluchenija, ocenki soderzhanija radioaktivnyh materialov v organizme, obnaruzhenija i regulirovanija zagrjaznenija okruzhajushhej sredy i bystrogo sostavlenija dannyh ob obluchenii v kachestve rukovodstva dlja personala skoroj pomoshhi i vrachej. Osnovnoj upor delaetsja na hjenfordskij plenochnyj dozimetr, kotoryj imeet pri sebe vse lica v predelah kontroliruemyh zon. Dozimetr obespechivaet pravil'noe vyjavlenie lichnosti vladel'ca, a ocenka plenki mozhet byt' provedena v techenie 90 minut. Razdel'no, i vmeste s tem odnovremenno, mozhno provesti obrabotku ostal'nyh sostavnyh chastej dozimetra s cel'ju opredelenija spektra nejtronov i velichiny dozy v pjati gruppah jenergii, a takzhe dat' bystruju ocenku nejtronnoj dozy pri odnokratnom stolknovenii, ot neskol'kih do tysjach rad. Gamma-luchi obnaruzhivajutsja v diapazone ot 20 millirentgen do 1500 rentgen (pri obrabotke komponentov plenki) i ot 10 do 10 000 rentgen (pri obrabotke jekranirovannyh tantalom ftoristyh sterzhnej). V avarijnuju sistemu vkljuchajutsja programmy, obespechivajushhie ponimanie sotrudnikami sistemy, podgotovku v oblasti dozimetrii i sotrudnichestvo s rukovodstvom v dele bystrogo vyjavlenija, kontrolirovanija i izolirovanija porazhennyh izlucheniem

  17. Dose Vocal: uma revisão integrativa da literatura

    Directory of Open Access Journals (Sweden)

    Joana Perpétuo Assad

    Full Text Available RESUMO O objetivo da pesquisa foi realizar uma revisão da literatura referente aos tipos de dose vocal e aos resultados destas medidas em diferentes situações comunicativas. Houve levantamento da literatura nacional e internacional, publicada nos idiomas Inglês, Espanhol ou Português, utilizando-se as bases de dados MEDLINE, LILACS, IBECS e ISI (Web of Science, dos últimos 21 anos, cujos artigos estavam disponíveis na íntegra. Quinze estudos contemplaram os critérios propostos. A maioria dos artigos estudou professores, visto que são mais vulneráveis para a ocorrência de disfonia. Os tipos de dose encontrados foram porcentagem de fonação, dose temporal, dose cíclica, dose de distância, dose de energia radiada e dose de energia dissipada. O aumento da dose vocal está associado ao uso excessivo e prolongado da voz na atividade docente, principalmente entre os professores da educação infantil e os de canto. As altas doses vocais correlacionam-se também à presença de disfonia, ao maior nível de ruído ambiental, à grande variação prosódica na fala e à autopercepção de fadiga vocal. Pacientes com disfonia comportamental (nódulos e pólipos apresentam maiores doses vocais que pacientes com outros quadros disfônicos. Fatores como repouso de voz e uso do amplificador vocal indicam a diminuição da dose da voz.

  18. Serie: Madera para construcción Acabados para madera

    OpenAIRE

    Sáenz-Muñoz, Marta; Instituto Tecnológico de Costa Rica

    2012-01-01

    Durante mucho tiempo, la madera ha sido utilizada como material de construcción para resolver principalmente objetivos estructurales; sin embargo, actualmente, el uso de la madera ha tomado mucho auge en la estética de las construcciones, para brindar apariencia y calidez. En la actualidad, el mercado ofrece una amplia gama productos para dar diversos “acabados” a la madera, los cuales sirven para resaltar la belleza de algunas de ellas, realzar características como el color y la veta, o bien...

  19. Tumor significant dose

    International Nuclear Information System (INIS)

    Supe, S.J.; Nagalaxmi, K.V.; Meenakshi, L.

    1983-01-01

    In the practice of radiotherapy, various concepts like NSD, CRE, TDF, and BIR are being used to evaluate the biological effectiveness of the treatment schedules on the normal tissues. This has been accepted as the tolerance of the normal tissue is the limiting factor in the treatment of cancers. At present when various schedules are tried, attention is therefore paid to the biological damage of the normal tissues only and it is expected that the damage to the cancerous tissues would be extensive enough to control the cancer. Attempt is made in the present work to evaluate the concent of tumor significant dose (TSD) which will represent the damage to the cancerous tissue. Strandquist in the analysis of a large number of cases of squamous cell carcinoma found that for the 5 fraction/week treatment, the total dose required to bring about the same damage for the cancerous tissue is proportional to T/sup -0.22/, where T is the overall time over which the dose is delivered. Using this finding the TSD was defined as DxN/sup -p/xT/sup -q/, where D is the total dose, N the number of fractions, T the overall time p and q are the exponents to be suitably chosen. The values of p and q are adjusted such that p+q< or =0.24, and p varies from 0.0 to 0.24 and q varies from 0.0 to 0.22. Cases of cancer of cervix uteri treated between 1978 and 1980 in the V. N. Cancer Centre, Kuppuswamy Naidu Memorial Hospital, Coimbatore, India were analyzed on the basis of these formulations. These data, coupled with the clinical experience, were used for choice of a formula for the TSD. Further, the dose schedules used in the British Institute of Radiology fraction- ation studies were also used to propose that the tumor significant dose is represented by DxN/sup -0.18/xT/sup -0.06/

  20. [Evaluation of Organ Dose Estimation from Indices of CT Dose Using Dose Index Registry].

    Science.gov (United States)

    Iriuchijima, Akiko; Fukushima, Yasuhiro; Ogura, Akio

    Direct measurement of each patient organ dose from computed tomography (CT) is not possible. Most methods to estimate patient organ dose is using Monte Carlo simulation with dedicated software. However, dedicated software is too expensive for small scale hospitals. Not every hospital can estimate organ dose with dedicated software. The purpose of this study was to evaluate the simple method of organ dose estimation using some common indices of CT dose. The Monte Carlo simulation software Radimetrics (Bayer) was used for calculating organ dose and analysis relationship between indices of CT dose and organ dose. Multidetector CT scanners were compared with those from two manufactures (LightSpeed VCT, GE Healthcare; SOMATOM Definition Flash, Siemens Healthcare). Using stored patient data from Radimetrics, the relationships between indices of CT dose and organ dose were indicated as each formula for estimating organ dose. The accuracy of estimation method of organ dose was compared with the results of Monte Carlo simulation using the Bland-Altman plots. In the results, SSDE was the feasible index for estimation organ dose in almost organs because it reflected each patient size. The differences of organ dose between estimation and simulation were within 23%. In conclusion, our estimation method of organ dose using indices of CT dose is convenient for clinical with accuracy.

  1. Effects of proton radiation dose, dose rate and dose fractionation on hematopoietic cells in mice

    International Nuclear Information System (INIS)

    Ware, J.H.; Rusek, A.; Sanzari, J.; Avery, S.; Sayers, C.; Krigsfeld, G.; Nuth, M.; Wan, X.S.; Kennedy, A.R.

    2010-01-01

    The present study evaluated the acute effects of radiation dose, dose rate and fractionation as well as the energy of protons in hematopoietic cells of irradiated mice. The mice were irradiated with a single dose of 51.24 MeV protons at a dose of 2 Gy and a dose rate of 0.05-0.07 Gy/min or 1 GeV protons at doses of 0.1, 0.2, 0.5, 1, 1.5 and 2 Gy delivered in a single dose at dose rates of 0.05 or 0.5 Gy/min or in five daily dose fractions at a dose rate of 0.05 Gy/min. Sham-irradiated animals were used as controls. The results demonstrate a dose-dependent loss of white blood cells (WBCs) and lymphocytes by up to 61% and 72%, respectively, in mice irradiated with protons at doses up to 2 Gy. The results also demonstrate that the dose rate, fractionation pattern and energy of the proton radiation did not have significant effects on WBC and lymphocyte counts in the irradiated animals. These results suggest that the acute effects of proton radiation on WBC and lymphocyte counts are determined mainly by the radiation dose, with very little contribution from the dose rate (over the range of dose rates evaluated), fractionation and energy of the protons.

  2. Effects of proton radiation dose, dose rate and dose fractionation on hematopoietic cells in mice.

    Science.gov (United States)

    Ware, J H; Sanzari, J; Avery, S; Sayers, C; Krigsfeld, G; Nuth, M; Wan, X S; Rusek, A; Kennedy, A R

    2010-09-01

    The present study evaluated the acute effects of radiation dose, dose rate and fractionation as well as the energy of protons in hematopoietic cells of irradiated mice. The mice were irradiated with a single dose of 51.24 MeV protons at a dose of 2 Gy and a dose rate of 0.05-0.07 Gy/min or 1 GeV protons at doses of 0.1, 0.2, 0.5, 1, 1.5 and 2 Gy delivered in a single dose at dose rates of 0.05 or 0.5 Gy/min or in five daily dose fractions at a dose rate of 0.05 Gy/min. Sham-irradiated animals were used as controls. The results demonstrate a dose-dependent loss of white blood cells (WBCs) and lymphocytes by up to 61% and 72%, respectively, in mice irradiated with protons at doses up to 2 Gy. The results also demonstrate that the dose rate, fractionation pattern and energy of the proton radiation did not have significant effects on WBC and lymphocyte counts in the irradiated animals. These results suggest that the acute effects of proton radiation on WBC and lymphocyte counts are determined mainly by the radiation dose, with very little contribution from the dose rate (over the range of dose rates evaluated), fractionation and energy of the protons.

  3. "Colaborar para Competir"

    Directory of Open Access Journals (Sweden)

    Martha Liliana Hijuelos-Cárdenas

    2015-06-01

    Full Text Available De acuerdo con Michael Porter, los Clusters se definen como “Una agrupación de empresas e instituciones relacionadas entre sí, pertenecientes a un mismo sector o segmento de mercado, que se encuentran próximas geográficamente y que colaboran para ser más competitivas”. Los Clusters son en última instancia una herramienta de competitividad basada en la cooperación de sus miembros, y es una de las estrategias recientes, en el país, para incrementar la productividad y competitividad y las apuestas productivas desde el nivel local. Y es precisamente esta cercanía geográfica de las empresas de un mismo sector, lo que a la vez que genera la competencia entre ellas, también les facilita el acceso a insumos y a conocimientos específicos y en última instancia les permite promover la innovación.

  4. Principios teatrales para docentes

    Directory of Open Access Journals (Sweden)

    R. Irene Arroyo Zúñiga

    2005-01-01

    Full Text Available Este trabajo pretende dar herramientas a los docentes para que puedan utilizarlas como parte de las actividades dentro de un plan de elección, en cualquier disciplina. Además encontrará una exposición de los elementos que componen el arte de la representación escénica, como son: 1. Expresión corporal; es la capacidad de expresar emociones partiendo únicamente de nuestro cuerpo. 2. Impostación; es la habilidad de proyectar la voz sin lastimar las cuerdas vocales. 3. Dicción; es la pronunciación correcta de las palabras. 4. Actuación; es la posibilidad de crear un personaje partiendo de los recursos expresivos y de la forma natural en que el alumno acostumbra a reaccionar. Técnica de improvisación, en éste artículo propongo una serie de seis pasos que pueden ser de gran ayuda a la hora de usar el teatro como recurso didáctico. El teatro a lo largo de la historia ha sido usado para transmitir conocimientos, valores, creencias y todo aspecto inherente a los individuos y su entorno social. Por lo tanto debemos aprovechar al máximo los beneficios que nos ofrece el teatro como educadores

  5. The methodology proposed to estimate the absorbed dose at the entrance of the labyrinth in HDR brachytherapy facilities with IR-192; Propuesta de metodologia para estimar la dosis absorbida en la entrada del laberinto en instalaciones de braquiterapia HDR con Ir-192

    Energy Technology Data Exchange (ETDEWEB)

    Pujades, M. C.; Perez-Calatayud, J.; Ballester, F.

    2012-07-01

    In the absence of procedure for evaluating the design of a brachytherapy (BT) vault with maze from the point of view of radiation protection, usually formalism of external radiation is adapted. The purpose of this study is to adapt the methodology described by the National council on Radiological Protection and Measurements Report 151 (NCRP 151). Structural Shielding Design for megavoltage X-and Gamma-Ray Radiotherapy facilities, for estimating dose at the door in BT and its comparison with the results megavoltage X-and Gamma-Ray Radiotherapy Facilities, for estimating dose at the door in BT and its comparison with the results obtained by the method of Monte Carlo (MC) for a special case of bunker. (Author) 17 refs.

  6. Occupational dose assessment and national dose registry system in Iran

    International Nuclear Information System (INIS)

    Jafari-Zadeh, M.; Nazeri, F.; Hosseini-Pooya, S. M.; Taheri, M.; Gheshlaghi, F.; Kardan, M. R.; Babakhani, A.; Rastkhah, N.; Yousefi-Nejad, F.; Darabi, M.; Oruji, T.; Gholamali-Zadeh, Z.; Karimi-Diba, J.; Kazemi-Movahed, A. A.; Dashti-Pour, M. R.; Enferadi, A.; Jahanbakhshian, M. H.; Sadegh-Khani, M. R.

    2011-01-01

    This report presents status of external and internal dose assessment of workers and introducing the structure of National Dose Registry System of Iran (NDRSI). As well as types of individual dosemeters in use, techniques for internal dose assessment are presented. Results obtained from the International Atomic Energy Agency intercomparison programme on measurement of personal dose equivalent H p (10) and consistency of the measured doses with the delivered doses are shown. Also, implementation of dosimetry standards, establishment of quality management system, authorisation and approval procedure of dosimetry service providers are discussed. (authors)

  7. Simulation of dose deposition in heterogeneities in the human body, using the Penelope code for photons beams of energies of a linear accelerator; Simulacion de la deposicion de dosis en las heterogeneidades del cuerpo humano, usando el codigo Penelope para haces de fotones de energias de un acelerador lineal

    Energy Technology Data Exchange (ETDEWEB)

    Cardena R, A. R.; Vega R, J. L.; Apaza V, D. G., E-mail: cardroj@yahoo.es [Universidad Nacional de San Agustin, Av. Independencia s/n, Arequipa (Peru)

    2015-10-15

    The progress in cancer treatment systems in heterogeneities of human body has had obstacles by the lack of a suitable experimental model test. The only option is to develop simulated theoretical models that have the same properties in interfaces similar to human tissues, to know the radiation behavior in the interaction with these materials. In this paper we used the Monte Carlo method by Penelope code based solely on studies for the cancer treatment as well as for the calibration of beams and their various interactions in mannequins. This paper also aims the construction, simulation and characterization of an equivalent object to the tissues of the human body with various heterogeneities, we will later use to control and plan experientially doses supplied in treating tumors in radiotherapy. To fulfill the objective we study the ionizing radiation and the various processes occurring in the interaction with matter; understanding that to calculate the dose deposited in tissues interfaces (percentage depth dose) must be taken into consideration aspects such as the deposited energy, irradiation fields, density, thickness, tissue sensitivity and other items. (Author)

  8. Doses from radiation exposure

    CERN Document Server

    Menzel, H G

    2012-01-01

    Practical implementation of the International Commission on Radiological Protection's (ICRP) system of protection requires the availability of appropriate methods and data. The work of Committee 2 is concerned with the development of reference data and methods for the assessment of internal and external radiation exposure of workers and members of the public. This involves the development of reference biokinetic and dosimetric models, reference anatomical models of the human body, and reference anatomical and physiological data. Following ICRP's 2007 Recommendations, Committee 2 has focused on the provision of new reference dose coefficients for external and internal exposure. As well as specifying changes to the radiation and tissue weighting factors used in the calculation of protection quantities, the 2007 Recommendations introduced the use of reference anatomical phantoms based on medical imaging data, requiring explicit sex averaging of male and female organ-equivalent doses in the calculation of effecti...

  9. Radiation dose rate meter

    International Nuclear Information System (INIS)

    Kronenberg, S.; Siebentritt, C.R.

    1981-01-01

    A combined dose rate meter and charger unit therefor which does not require the use of batteries but on the other hand produces a charging potential by means of a piezoelectric cylinder which is struck by a manually triggered hammer mechanism. A tubular type electrometer is mounted in a portable housing which additionally includes a geiger-muller (Gm) counter tube and electronic circuitry coupled to the electrometer for providing multi-mode operation. In one mode of operation, an rc circuit of predetermined time constant is connected to a storage capacitor which serves as a timed power source for the gm tube, providing a measurement in terms of dose rate which is indicated by the electrometer. In another mode, the electrometer indicates individual counts

  10. Small dose... big poison.

    Science.gov (United States)

    Braitberg, George; Oakley, Ed

    2010-11-01

    It is not possible to identify all toxic substances in a single journal article. However, there are some exposures that in small doses are potentially fatal. Many of these exposures are particularly toxic to children. Using data from poison control centres, it is possible to recognise this group of exposures. This article provides information to assist the general practitioner to identify potential toxic substance exposures in children. In this article the authors report the signs and symptoms of toxic exposures and identify the time of onset. Where clear recommendations on the period of observation and known fatal dose are available, these are provided. We do not discuss management or disposition, and advise readers to contact the Poison Information Service or a toxicologist for this advice.

  11. Radiation dose measurements

    International Nuclear Information System (INIS)

    1960-01-01

    About 200 scientists from 28 countries and 5 international organizations met at a symposium on radiation dosimetry held by the International Atomic Energy Agency in June 1960. The aim of the symposium was not so much the description of a large number of measuring instruments as a discussion of the methods used, with special emphasis on those problems which had become important in the context of recent developments, such as the measurement of mixed or very large doses

  12. Low dose epidemiology

    International Nuclear Information System (INIS)

    Tirmarche, M.; Hubert, P.

    1992-01-01

    Actually, epidemiological studies have to establish if the assessment of cancer risk can be verified at low chronic radiation doses. The population surveillance must be very long, the side effects and cancers of such radiation appearing much later. In France, this epidemiological study on nuclear workers have been decided recently. Before describing the experiment and french projects in epidemiology of nuclear workers, the authors present the main english and american studies

  13. Time-dose modifications

    International Nuclear Information System (INIS)

    Kian Ang, K.

    1987-01-01

    Changes in fractionation schedule can be made by various approaches. However, from the first principle, it is anticipated that strategies of hyperfractionation and/or accelerated fractionation offer the most promised in improving the therapeutic ratio. Hyperfractionation is defined as a treatment schedule in which a large number of significantly reduced dose fractions (--1.2 Gy/fraction) is used to give a greater total dose in a conventional overall time period. The results of the pilot studies testing the efficacy of hyperfractionation have been encouraging. The most valid clinical trial of pure hyperfractionation, however, is that conducted by the EORTC. This study compared 70 Gy in 35 fractions or 80.5 Gy in 70 fractions over 7 weeks in the treatment of patients with oropharyngeal carcinomas. The local tumor control was significantly improved in the hyperfractionated arm without increasing the morbidity. Accelerated fractionation is defined as a schedule in which the overall time of treatment is reduced without significant changes in the total dose and fraction size. The strategy has been used to treat patients with malignant gliomas, melanomas and Head and Neck cancers. The data in Head and Neck Cancers seem to be promising

  14. Dose calculation for electrons

    International Nuclear Information System (INIS)

    Hirayama, Hideo

    1995-01-01

    The joint working group of ICRP/ICRU is advancing the works of reviewing the ICRP publication 51 by investigating the data related to radiation protection. In order to introduce the 1990 recommendation, it has been demanded to carry out calculation for neutrons, photons and electrons. As for electrons, EURADOS WG4 (Numerical Dosimetry) rearranged the data to be calculated at the meeting held in PTB Braunschweig in June, 1992, and the question and request were presented by Dr. J.L. Chartier, the responsible person, to the researchers who are likely to undertake electron transport Monte Carlo calculation. The author also has carried out the requested calculation as it was the good chance to do the mutual comparison among various computation codes regarding electron transport calculation. The content that the WG requested to calculate was the absorbed dose at depth d mm when parallel electron beam enters at angle α into flat plate phantoms of PMMA, water and ICRU4-element tissue, which were placed in vacuum. The calculation was carried out by the versatile electron-photon shower computation Monte Carlo code, EGS4. As the results, depth dose curves and the dependence of absorbed dose on electron energy, incident angle and material are reported. The subjects to be investigated are pointed out. (K.I.)

  15. Dose reduction in evacuation proctography

    International Nuclear Information System (INIS)

    Hare, C.; Halligan, S.; Bartram, C.I.; Gupta, R.; Walker, A.E.; Renfrew, I.

    2001-01-01

    The goal of this study was to reduce the patient radiation dose from evacuation proctography. Ninety-eight consecutive adult patients referred for proctography to investigate difficult rectal evacuation were studied using a digital imaging system with either a standard digital program for barium examinations, a reduced dose digital program (both with and without additional copper filtration), or Video fluoroscopy. Dose-area products were recorded for each examination and the groups were compared. All four protocols produced technically acceptable examinations. The low-dose program with copper filtration (median dose 382 cGy cm 2 ) and Video fluoroscopy (median dose 705 cGy cm 2 ) were associated with significantly less dose than other groups (p < 0.0001). Patient dose during evacuation proctography can be reduced significantly without compromising the diagnostic quality of the examination. A digital program with added copper filtration conveyed the lowest dose. (orig.)

  16. Optimized dose distribution of a high dose rate vaginal cylinder

    International Nuclear Information System (INIS)

    Li Zuofeng; Liu, Chihray; Palta, Jatinder R.

    1998-01-01

    Purpose: To present a comparison of optimized dose distributions for a set of high-dose-rate (HDR) vaginal cylinders calculated by a commercial treatment-planning system with benchmark calculations using Monte-Carlo-calculated dosimetry data. Methods and Materials: Optimized dose distributions using both an isotropic and an anisotropic dose calculation model were obtained for a set of HDR vaginal cylinders. Mathematical optimization techniques available in the computer treatment-planning system were used to calculate dwell times and positions. These dose distributions were compared with benchmark calculations with TG43 formalism and using Monte-Carlo-calculated data. The same dwell times and positions were used for a quantitative comparison of dose calculated with three dose models. Results: The isotropic dose calculation model can result in discrepancies as high as 50%. The anisotropic dose calculation model compared better with benchmark calculations. The differences were more significant at the apex of the vaginal cylinder, which is typically used as the prescription point. Conclusion: Dose calculation models available in a computer treatment-planning system must be evaluated carefully to ensure their correct application. It should also be noted that when optimized dose distribution at a distance from the cylinder surface is calculated using an accurate dose calculation model, the vaginal mucosa dose becomes significantly higher, and therefore should be carefully monitored

  17. Método de diagnóstico para el monitoreo de resistencia a insecticidas en poblaciones de “picudo del algodonero”, Anthonomus grandis (Coleoptera: Curculionidae

    Directory of Open Access Journals (Sweden)

    Teodoro STADLER

    2009-01-01

    Full Text Available El control de las poblaciones de Anthonomus grandis Boheman, por debajo de su umbral de daño económico durante el ciclo del cultivo del algodón, se realiza en forma efectiva hasta el momento, a través de insecticidas de síntesis. La presión selectiva de las aplicaciones extensivas e intensivas de insecticidas hace imperativa la detección temprana de focos de resistencia a los mismos, en función de un correcto manejo del fenómeno. Se desarrolló un método de diagnóstico de resistencia para A. grandis a partir de la técnica “vial test”, que fue adaptada en forma de “kit” para el monitoreo rápido y sencillo de los focos de resistencia en el campo. La toxicidad (CL99, para calcular la concentración discriminante (CD del insecticida y la preparación del “kit”, se obtiene a partir de bioensayos de laboratorio con una cepa normal susceptible de A. grandis. Se determinó la vida media de los insecticidas dentro de los viales por CIPAC MT 46, para establecer una fecha de vencimiento del “kit”. La CD y el método en su conjunto fueron validados a través de ensayos a campo. El “kit”, usado en el monitoreo de resistencia en el campo, fue especialmente diseñado para ser utilizado en las condiciones geográficas, económicas y socio-culturales presentes en la región algodonera argentina. La implementación de esta técnica permitirá conseguir la información necesaria, y así obtener una apropiada alternancia de insecticidas. Como consecuencia, se prevé una reducción de impactoambiental de las prácticas agronómicas en el control de plagas en algodón.

  18. Ruptura de aneurismas de aorta abdominal. Herramienta informática para su predicción // Rupture of abdominal aortic aneurysm. Software for its prediction

    Directory of Open Access Journals (Sweden)

    Guillermo Villalta‐Alonso

    2011-01-01

    Full Text Available La ruptura de los aneurismas de aorta abdominal representa un evento clínico muy importantedebido a su alta tasa de mortalidad. Los indicadores empleados actualmente para decidir eltratamiento a pacientes con aneurismas son el diámetro máximo transversal y la tasa de crecimiento,los que pueden ser considerados insuficientes, pues no tienen una base teórica físicamentefundamentada. En el presente artículo se definen los fundamentos para el diseño de una herramientainformática para PC que permita predecir, con suficiente precisión para ser clínicamente relevante, elriesgo de ruptura de aneurismas de aorta abdominal sobre bases personalizadas del paciente. Laherramienta consta de 3 módulos, que están diseñados para procesar toda la información delpaciente e integrarla mediante un modelo que incorpora la interrelación de los factores biomecánicosde diferentes naturalezas (biológicos, estructurales y geométrico y escalas (temporal y dimensional,con el objetivo de calcular un indicador numérico y personalizado del riesgo de ruptura. Estaherramienta debe constituir un elemento auxiliar del facultativo médico en la toma de decisionesrespecto del tratamiento adecuado a pacientes con aneurisma.Palabras claves: AAA, riesgo de ruptura, modelo multiescala, predicción, herramienta informática.___________________________________________________________________AbstractThe rupture of abdominal aortic aneurysm (AAA represents an important clinical event due to its highmortality rate. Currently the criteria to decide on the treatment of AAA patients are the peaktransverse diameter and the growth rate which can be considered insufficient because they have nota reasonable physical base. The foundations for the design of PC software to predict, with sufficientaccuracy to be clinically relevant, the risk of AAA rupture on patient-specific basis are defined in thispaper. The software consists of 3 modules which are designed for processing all

  19. Bases para proyectiles dirigidos

    Directory of Open Access Journals (Sweden)

    Editorial, Equipo

    1959-03-01

    Full Text Available Aunque actualmente no se ha llegado a una línea general de métodos o sistemas que gobiernen un tipo característico de rampa y servicios auxiliares necesarios para el lanzamiento al espacio de proyectiles dirigidos a grandes alturas y distancias, las experiencias obtenidas en diferentes ensayos, utilizando distintos tipos de proyectiles y trayectorias balísticas, han sentado toda una serie de procedimientos, datos y conclusiones de gran valor balístico que, aun teniendo en cuenta la continua evolución del proyectil, sus formas, combustibles y alcances, se conocen ya, con bastante aproximación, las condiciones mínimas que ha de reunir una base dedicada a este tipo de lanzamientos.

  20. Dose gradient curve: A new tool for evaluating dose gradient.

    Science.gov (United States)

    Sung, KiHoon; Choi, Young Eun

    2018-01-01

    Stereotactic radiotherapy, which delivers an ablative high radiation dose to a target volume for maximum local tumor control, requires a rapid dose fall-off outside the target volume to prevent extensive damage to nearby normal tissue. Currently, there is no tool to comprehensively evaluate the dose gradient near the target volume. We propose the dose gradient curve (DGC) as a new tool to evaluate the quality of a treatment plan with respect to the dose fall-off characteristics. The average distance between two isodose surfaces was represented by the dose gradient index (DGI) estimated by a simple equation using the volume and surface area of isodose levels. The surface area was calculated by mesh generation and surface triangulation. The DGC was defined as a plot of the DGI of each dose interval as a function of the dose. Two types of DGCs, differential and cumulative, were generated. The performance of the DGC was evaluated using stereotactic radiosurgery plans for virtual targets. Over the range of dose distributions, the dose gradient of each dose interval was well-characterized by the DGC in an easily understandable graph format. Significant changes in the DGC were observed reflecting the differences in planning situations and various prescription doses. The DGC is a rational method for visualizing the dose gradient as the average distance between two isodose surfaces; the shorter the distance, the steeper the dose gradient. By combining the DGC with the dose-volume histogram (DVH) in a single plot, the DGC can be utilized to evaluate not only the dose gradient but also the target coverage in routine clinical practice.

  1. Efecto de la cantidad de cría de abeja Apis mellifera (Apidae sobre la eficacia del Oxavar® para el control del ácaro Varroa destructor (Varroidae Effect of Apis mellifera (Apidae honeybee brood amount on Oxavar® acaricide efficacy against the mite Varroa destructor (Varroidae

    Directory of Open Access Journals (Sweden)

    Jorge Marcangeli

    2004-12-01

    Full Text Available El objetivo del presente trabajo fue evaluar la eficacia acaricida del Oxavar® en el control del ácaro ectoparásito Varroa destructor (Anderson & Trueman. El trabajo fue realizado en el apiario experimental del Centro de Extensión Apícola ubicado en Coronel Vidal, provincia de Buenos Aires. Se seleccionaron diez colmenas tipo Langstroth que fueron divididas en dos grupos: a cinco colmenas con tres cuadros cubiertos completamente de cría en desarrollo y b cinco colmenas con seis cuadros cubiertos por cría. Ambos grupos recibieron cinco ml of Oxavar® (Apilab, Argentina; 64,6 g/l de ácido oxálico en agua destilada por cuadro cubierto por abejas adultas en tres dosis a intervalos de siete días. Semanalmente, se colectaron los ácaros muertos de los pisos especiales provistos a las colmenas de estudio con el objeto de evitar su remoción por parte de las abejas. Una vez concluido el tratamiento, en cada colmena se introdujeron dos tiras plásticas de Apistan® (Roteh, Argentina para eliminar los ácaros remanentes y poder así calcular la eficacia acaricida del Oxavar®. Los resultados mostraron que la eficacia del Oxavar® en el primer grupo (85,6% ± 1,4 resultó significativamente superior a la registrada en el segundo grupo (75,7 ± 1,7. Estas diferencias fueron testeadas a partir del número total de ácaros eliminados por el Oxavar® y Apistan® en ambos grupos de colmenas (pThe aim of this work was to evaluate the effect of honeybee brood on acaricide efficacy of Oxavar® to control the ectoparasitic mite Varroa destructor (Anderson & Trueman. Work was done at Centro de Extensión Apícola experimental apiary located at Coronel Vidal, province of Buenos Aires. Ten Langstroth hives were selected and divided in two groups: a hives containing three honeybee combs full of brood and b hives containing six honeybee brood combs. Both groups received five ml of Oxavar® (Laboratorio Apilab, Argentina; 64.6 g/l oxalic acid in destilled water

  2. Registrar para avanzar

    Directory of Open Access Journals (Sweden)

    Laia Matarranz Torres

    2017-06-01

    Full Text Available El farmacéutico comunitario es un profesional sanitario con un enorme potencial para mejorar no solo el uso de los medicamentos (detectando, por ejemplo, resultados negativos de la medicación, sino también la prevención de enfermedades y la promoción de la salud pública. Sin duda, el desarrollo y el impulso que están teniendo los servicios profesionales farmacéuticos (SPF desde hace años pueden contribuir decisivamente a que este potencial se consolide de una forma definitiva, obteniendo el reconocimiento del conjunto del sistema sanitario, incluyendo tanto a otros profesionales de la salud (médicos, enfermería, medicina especializada… como a la Administración y, por supuesto, a los propios pacientes beneficiarios de estos servicios. Es cierto que la figura del farmacéutico y su ejercicio sanitario han estado tradicionalmente bien considerados por la población, pero no es menos verdad que la integración de la actividad asistencial de la farmacia comunitaria en el Sistema Nacional de Salud (SNS es, cuanto menos mejorable, y que, incluso, algunas manifestaciones ponen en entredicho de vez en cuando la labor científico-asistencial de las farmacias o generan dudas sobre su capacidad para formar parte de pleno derecho de los equipos de salud que deben trabajar de forma coordinado en la mejora de la atención sanitaria de los pacientes.

  3. Determination of organ doses and effective doses in radiooncology

    International Nuclear Information System (INIS)

    Roth, J.; Martinez, A.E.

    2007-01-01

    Background and Purpose: With an increasing chance of success in radiooncology, it is necessary to estimate the risk from radiation scatter to areas outside the target volume. The cancer risk from a radiation treatment can be estimated from the organ doses, allowing a somewhat limited effective dose to be estimated and compared. Material and Methods: The doses of the radiation-sensitive organs outside the target volume can be estimated with the aid of the PC program PERIDOSE developed by van der Giessen. The effective doses are determined according to the concept of ICRP, whereby the target volume and the associated organs related to it are not taken into consideration. Results: Organ doses outside the target volume are generally < 1% of the dose in the target volume. In some cases, however, they can be as high as 3%. The effective doses during radiotherapy are between 60 and 900 mSv, depending upon the specific target volume, the applied treatment technique, and the given dose in the ICRU point. Conclusion: For the estimation of the radiation risk, organ doses in radiooncology can be calculated with the aid of the PC program PERIDOSE. While evaluating the radiation risk after ICRP, for the calculation of the effective dose, the advanced age of many patients has to be considered to prevent that, e.g., the high gonad doses do not overestimate the effective dose. (orig.)

  4. Calculus of spatial distribution of absorbed dose to cellular level by Monte Carlo simulation for a radio-labelled peptide with {sup 188}Re and with nuclear internalization : preliminary results; Calculo de la distribucion espacial de dosis absorbida a nivel celular por simulacion Monte Carlo para un peptido radiomarcado con {sup 188}Re y con internalizacion nuclear : resultados preliminares

    Energy Technology Data Exchange (ETDEWEB)

    Rojas C, E. L. [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Santos C, C. L. [Universidad Autonoma del Estado de Mexico, Paseo Tollocan y Jesus Carranza, Toluca 50120, Estado de Mexico (Mexico)], e-mail: leticia.rojas@inin.gob.mx

    2009-10-15

    The {sup 188}Re is a radionuclide of radiation gamma emitter, useful in obtaining of gamma-graphic images, but it is also emitter of beta radiations and Auger electrons. A bio-molecule directed to a specific receptor of a cancer cell labeled with a emitter radionuclide of beta particles and Auger electrons, as the {sup 188}Re-Tat-Bombesin, it has the potential to be used in radiotherapy of molecular targets for its capacity to penetrate to cellular nucleus. In this system, the radiation dose is distributed in way located at microscopic levels in sub cellular specific places, where Auger emissions contributes of significant way in absorbed dose. The cellular dosimetry is realized in most of cases, using analytic or semi analytical methods, for example the cellular MIRD methodology. However, it is required to complement these calculations simulating the electrons transport and considering experimental bio kinetics data. Therefore, in this work preliminary results are presented of dosimetric calculation to sub cellular level for {sup 188}Re-Tat-Bombesin by Monte Carlo simulation, using the 2008 version of PENELOPE: PENEASY code. The spatial distribution of absorbed dose in membrane, cytoplasm and nucleus, was calculated with geometry of a cell of 10 {mu}m of diameter, a nucleus of 2 {mu}m of ratio and membrane of 0.2 {mu}m of thickness, considering elementary constitution for each cellular compartment proposal in literature. The total number of disintegrations at sub cellular level was evaluated integrating the activity in function of time starting from experimental bio kinetics data in mamma cancer cells MDA-MB231. The preliminary results show that 46.4% of total disintegrations for unit of captured activity by cell occurs in nucleus, 38.4% in membrane and 15.2% in cytoplasm. The due absorbed dose to Auger electrons for 1 Bq of {sup 188}Re located in cellular membrane were respectively of 1.32E-1 and 1.43E-1 Gy in cytoplasm and nucleus. (Author)

  5. Determinación de parámetros de transformación local para escalas cartográficas grandes: Apoyo al proceso de migración de Internacional Bogotá a MAGNA SIRGAS

    Directory of Open Access Journals (Sweden)

    Gil Pérez Sandra Milena

    2011-11-01

    Full Text Available El presente trabajo busca calcular parámetros de transformación local para ser aplicados en procesos de migración de datos al nuevo Sistema de Referencia MAGNASIRGAS. Constituye también un acercamiento a este Datum como plataforma de georreferenciación del país en reemplazo del antiguo Datum Bogotá. El informe completo establece el contexto espacial de los trabajos, esbozando sus características en cuanto a condiciones fisiográficas, edáficas y de zonas de vida. El marco conceptual presenta un estado del arte de los principales conceptos teóricos y prácticos que dan base al proyecto y que permiten entender procesos que se abordan en los capítulos siguientes. La metodología establece paso a paso las tareas seguidas que permitieron lograr los objetivos trazados por el estudio en cuanto al cálculo de parámetros y a su utilización acertada a un conjunto de datos espaciales. En este aparte del documento, pueden monitorearse claramente no solo los procesos, sino todas las herramientas tecnológicas necesarias, representadas en programas de postproceso y cálculo, que permitieron a este trabajo ser una experiencia exitosa.

  6. Observación de las estrategias que emplean los profesores de educación física para enseñar responsabilidad personal y social

    Directory of Open Access Journals (Sweden)

    Amparo Escart\\u00ED

    2013-01-01

    Full Text Available El objetivo de este trabajo ha sido doble: (1 Calcular las propiedades psicométricas de la primera parte de la versión española del Tool for Assessing Responsibility-Based Education (TARE que hemos denominado “Instrumento de observación de las estrategias de los profesores para enseñar responsabilidad”; (2 analizar las diferentes estrategias docentes utilizadas por 4 profesores de educación física en sus clases. Los resultados indicaron que la versión española de este instrumento presenta fiabilidad y validez satisfactorias. Por otro lado, respecto a las estrategias empleadas encontramos que los cuatro docentes fueron ejemplo de respeto y dieron a los alumnos la oportunidad de participar con éxito en las actividades de clase. Sin embargo, en general, utilizaron en pocas ocasiones estrategias que favorecieran la autonomía y la capacidad de liderazgo. También fue muy bajo en todos los profesores el uso de la transferencia y la utilización de estrategias encaminadas a la participación de los alumnos en el proceso de evaluación de su propio aprendizaje. Se observaron diferencias entre los profesores, en las estrategias docentes encaminadas a dar voz al alumnado.

  7. Intercomparison On Depth Dose Measurement

    International Nuclear Information System (INIS)

    Rohmah, N; Akhadi, M

    1996-01-01

    Intercomparation on personal dose evaluation system has been carried out between CSRSR-NAEA of Indonesia toward Standard Laboratory of JAERI (Japan) and ARL (Australia). The intercomparison was in 10 amm depth dose measurement , Hp (10), from the intercomparison result could be stated that personal depth dose measurement conducted by CSRSR was sufficiently good. Deviation of dose measurement result using personal dosemeter of TLD BG-1 type which were used by CSRSR in the intercomparison and routine photon personal dose monitoring was still in internationally agreed limit. Maximum deviation of reported doses by CSRSR compared to delivered doses for dosemeter irradiation by JAERI was -10.0 percent and by ARL was +29 percent. Maximum deviation permitted in personal dose monitoring is ± 50 percent

  8. Dose-to-man studies

    International Nuclear Information System (INIS)

    Anon.

    1976-01-01

    Dose-to-Man Studies focused on developing computer data handling and computer modules which permit easy, rapid assessment of the dose to southeastern United States populations from routine or accidental releases of radionuclides to atmospheric and stream systems

  9. Dose monitoring in nuclear emergency

    International Nuclear Information System (INIS)

    Nan Hongjie; Yang Zhongping; Lei Xin

    2012-01-01

    In order to protect people from irradiation sickness and rebuild the radiation filed in nuclear emergency, personal and environmental dose need to be monitored. The application of TLD in dose monitoring is discussed in this paper. (authors)

  10. Comparación de dos métodos de colecta para Anophelinos (Cebo humano y trampa de luz CDC, durante la época seca y lluviosa, Yurimaguas, Perú 2005.

    Directory of Open Access Journals (Sweden)

    Neil Salazar C

    2006-04-01

    Full Text Available Objetivo: Evaluar la efectividad de dos métodos de colectas para Anofelinos adultos (cebo humano y trampas de luz CDC, en el intra y peridomicilio durante la época lluviosa y seca entre enero a junio de 2005 en una localidad endémica de malaria del distrito de Yurimaguas, Loreto, Perú. Materiales y métodos: Las colectas de los mosquitos adultos con cebo humano y trampas de luz CDC se realizó en cinco barrios: San Juan, Santa Rosa, Central, San Antonio y Florida de la localidad de Munichis, Yurimaguas. Se seleccionaron nueve casas por cada método de colecta. Se estimaron ecuaciones de regresión lineal, cuadrática y cúbica para calcular el número de anofelinos colectados por cebo humano a partir de datos de captura por trampas de luz. Resultados: Se capturó 7790 anofelinos en cebos humanos y 1525 en trampas de luz. Durante toda la evaluación se encontraron nueve especies de Anopheles, siendo las cuatro más abundantes: Anopheles benarrochi Gabaldon, Cova & López, 1941 (85,2%, Anopheles rangeli Gabaldon, Cova & López, 1940 (7,3%, Anopheles konderi Galvao & Damasceno, 1942 (4,0% y Anopheles triannulatus Neiva & Pinto, 1922 (3,1%. La trampa de luz CDC capturó 16,4; 15,3; y 17,1% de anofelinos totales, en el intradomicilio y en el peridomicilio, respectivamente en comparación con los capturados por cebo humano. No existieron diferencias entre la época seca y lluviosa en ninguno de los parámetros evaluados. Conclusiones: Se proponen tres modelos de regresión para estimar el número de anofelinos colectados en cebos humanos intra y peridomiciliarios a partir de trampas de luz CDC.

  11. A review of radiology staff doses and dose monitoring requirements

    International Nuclear Information System (INIS)

    Martin, C. J.

    2009-01-01

    Studies of radiation doses received during X-ray procedures by radiology, cardiology and other clinical staff have been reviewed. Data for effective dose (E), and doses to the eyes, thyroid, hands and legs have been analysed. These data have been supplemented with local measurements to determine the most exposed part of the hand for monitoring purposes. There are ranges of 60-100 in doses to individual tissues reported in the literature for similar procedures at different centres. While ranges in the doses per unit dose-area product (DAP) are between 10 and 25, large variations in dose result from differences in the sensitivity of the X-ray equipment, the type of procedure and the operator technique, but protection factors are important in maintaining dose levels as low as possible. The influence of shielding devices is significant for determining the dose to the eyes and thyroid, and the position of the operator, which depends on the procedure, is the most significant factor determining doses to the hands. A second body dosemeter worn at the level of the collar is recommended for operators with high workloads for use in assessment of effective dose and the dose to the eye. It is proposed that the third quartile values from the distributions of dose per unit DAP identified in the review might be employed in predicting the orders of magnitude of doses to the eye, thyroid and hands, based on interventional operator workloads. Such dose estimates could be employed in risk assessments when reviewing protection and monitoring requirements. A dosemeter worn on the little finger of the hand nearest to the X-ray tube is recommended for monitoring the hand. (authors)

  12. The para-petroleum industry

    International Nuclear Information System (INIS)

    2002-07-01

    The para-petroleum industry includes societies that realize studies and installations for the deposits exploitation. This document presents the situation of the para-petroleum industry in 2001, the world investment growth of the activity, the french societies financial results and an inventory of the main operations in the amalgamation domain. (A.L.B.)

  13. Dose. Detriment. Limit assessment

    International Nuclear Information System (INIS)

    Breckow, J.

    2015-01-01

    One goal of radiation protection is the limitation of stochastic effects due to radiation exposure. The probability of occurrence of a radiation induced stochastic effect, however, is only one of several other parameters which determine the radiation detriment. Though the ICRP-concept of detriment is a quantitative definition, the kind of detriment weighting includes somewhat subjective elements. In this sense, the detriment-concept of ICRP represents already at the stage of effective dose a kind of assessment. Thus, by comparing radiation protection standards and concepts interconvertible or with those of environment or occupational protection one should be aware of the possibly different principles of detriment assessment.

  14. Radon dose and aerosols

    International Nuclear Information System (INIS)

    Planinic, J.; Radolic, V.; Faj, Z.; Vukovic, B.

    2000-01-01

    The equilibrium factor value (F) was measured in the NRPB radon chamber and the corresponding track density ratio (r = D/D 0 ) of bare (D) and diffusion (D 0 ) LR-115 nuclear track detectors was determined, as well as the regression equation F(r). Experiments with LR-115 nuclear track detectors and aerosol sources (burning candle and cigarette) were carried out in the Osijek University radon chamber and afterwards an empirical relationship between the equilibrium factor and aerosol concentration was derived. For the purpose of radon dose equivalent assessment, procedures for determining the unattached fraction of radon progeny were introduced using two nuclear track detectors. (author)

  15. Hanford Environmental Dose Reconstruction Project

    International Nuclear Information System (INIS)

    Cannon, S.D.; Finch, S.M.

    1992-10-01

    The objective of the Hanford Environmental Dose Reconstruction (HEDR) Project is to estimate the radiation doses that individuals and populations could have received from nuclear operations at Hanford since 1944. The independent Technical Steering Panel (TSP) provides technical direction. The project is divided into the following technical tasks. These tasks correspond to the path radionuclides followed from release to impact on humans (dose estimates):Source Terms, Environmental Transport, Environmental Monitoring Data, Demography, Food Consumption, and Agriculture, and Environmental Pathways and Dose Estimates

  16. Effective dose and dose to crystalline lens during angiographic procedures

    International Nuclear Information System (INIS)

    Pages, J.

    1998-01-01

    The highest radiation doses levels received by radiologists are observed during interventional procedures. Doses to forehead and neck received by a radiologist executing angiographic examinations at the department of radiology at the academic hospital (AZ-VUB) have been measured for a group of 34 examinations. The doses to crystalline lens and the effective doses for a period of one year have been estimated. For the crystalline lens the maximum dose approaches the ICRP limit, that indicates the necessity for the radiologist to use leaded glasses. (N.C.)

  17. Calculations of doses for the personnel wrapped up in the radiological accident of the Specialties Hospital of the National Medical Center ''Siglo XXI''; Calculos de dosis para el personal involucrado en el accidente radiologico del Hospital de Especialidades del Centro Medico Nacional ''Siglo XXI''

    Energy Technology Data Exchange (ETDEWEB)

    Cortes C, A. [CNSNS, Dr. Barragan 779, Col Narvarte, Mexico D.F. (Mexico)]. e-mail: acortes@cnsns.gob.mx

    2004-07-01

    In this work the methodology used by the National Commission of Nuclear Safety and Safeguards for the determination of the internal dose due to the ingestion of coffee with I-131 for the personnel of the service of nuclear medicine of the Hospital of Specialties of the National Medical Center ''Siglo XXI'' of the Mexican Institute of the Social Insurance (IMSS), that was poured in the coffeepot of the service by a deliberate act before mentioned, is presented. Three different techniques were used to determine the initial activity incorporated starting from the measurements of retained activity in thyroid for 6 people of the service of nuclear medicine; the techniques employee provided consistent results. Using the results of the technique of the best estimator, it was applied the proposed methodology by the International Commission of Radioprotection in its publication 30 to determine the absorbed doses by the personnel involved in the accident, with which the Commission determines the administrative consequences to those that it should be held the personnel and the directive of the service of nuclear medicine of the one nosocome. (Author)

  18. Dose planning and dose delivery in radiation therapy

    International Nuclear Information System (INIS)

    Knoeoes, T.

    1991-01-01

    A method has been developed for calibration of CT-numbers to volumetric electron density distributions using tissue substitutes of known elemental composition and experimentally determined electron density. This information have been used in a dose calculation method based on photon and electron interaction processes. The method utilizes a convolution integral between the photon fluence matrix and dose distribution kernels. Inhomogeneous media are accounted for using the theorems of Fano and O'Connor for scaling dose distribution kernels in proportion to electron density. For clinical application of a calculated dose plan, a method for prediction of accelerator output have been developed. The methods gives the number of monitor units that has to be given to obtain a certain absorbed dose to a point inside an irregular, inhomogeneous object. The method for verification of dose distributions outlined in this study makes it possible to exclude the treatment related variance contributions, making an objective evaluation of dose calculations with experiments feasible. The methods for electron density determination, dose calculation and prediction of accelerator output discussed in this study will all contribute to an increased accuracy in the mean absorbed dose to the target volume. However, a substantial gain in the accuracy for the spatial absorbed dose distribution will also follow, especially using CT for mapping of electron density together with the dose calculation algorithm. (au)

  19. Normal tissue dose-effect models in biological dose optimisation

    International Nuclear Information System (INIS)

    Alber, M.

    2008-01-01

    Sophisticated radiotherapy techniques like intensity modulated radiotherapy with photons and protons rely on numerical dose optimisation. The evaluation of normal tissue dose distributions that deviate significantly from the common clinical routine and also the mathematical expression of desirable properties of a dose distribution is difficult. In essence, a dose evaluation model for normal tissues has to express the tissue specific volume effect. A formalism of local dose effect measures is presented, which can be applied to serial and parallel responding tissues as well as target volumes and physical dose penalties. These models allow a transparent description of the volume effect and an efficient control over the optimum dose distribution. They can be linked to normal tissue complication probability models and the equivalent uniform dose concept. In clinical applications, they provide a means to standardize normal tissue doses in the face of inevitable anatomical differences between patients and a vastly increased freedom to shape the dose, without being overly limiting like sets of dose-volume constraints. (orig.)

  20. Absorbed dose in CT. Comparison by CT dose index

    International Nuclear Information System (INIS)

    Yamamoto, Kenji; Akazawa, Hiroshi; Andou, Takashi

    2002-01-01

    Few reports have discussed the absorbed dose on CT units with increased scanning capacity even with the current widespread adoption of multi-slice CT units. To compare and investigate the dose indexes among CT units, we measured the absorbed dose on CT units operating in Nagano Prefecture Japan. The measurements showed proportionality between phantom absorbed dose and the exposured mAs values in conventional scanning operation. Further, the measurements showed that the absorbed dose in the center of the phantom differed by about 2.1-fold between the highest and lowest levels on individual CT units. Within a single company, multi-slice CT units of the same company gave absorbed doses of about 1.3 to 1.5 times those of conventional single-slice CT units under the same exposured conditions of conventional scanning. When the scanning pitch was reduced in helical scanning, the absorbed dose at the center of the phantom increased. (author)

  1. Comparison of normal tissue dose with three-dimensional conformal techniques for breast cancer irradiation including the internal mammary nodes

    NARCIS (Netherlands)

    van der Laan, Hans Paul; Dolsma, Willemtje; van t Veld, Aart; Bijl, HP; Langendijk, JA

    2005-01-01

    PURPOSE: To compare the Para Mixed technique for irradiation of the internal mammary nodes (IMN) with three commonly used strategies, by analyzing the dose to the heart and other organs at risk. METHODS AND MATERIALS: Four different three-dimensional conformal dose plans were created for 30 breast

  2. Para-bosons and Para-fermions in Quantum Mechanics

    International Nuclear Information System (INIS)

    Cattani, M.S.D.; Fernandes, N.C.

    1982-01-01

    Within the framework of the ordinary quantum mechanics, a detailed study of the energy eigenfunctions of N identical particles using the irreducible representations of the permutation group in the Hilbert space is performed. It is shown that the para-states, as occurs with the boson and fermion states, are compatible with the postulates of quantum mechanics and with the principle of indistinguishability. A mathematical support for the existence of para-bosons and para-fermions is given. Gentile's quantum statistics is, in a certain sense, justified. (Author) [pt

  3. Generating para-water from para-hydrogen: A Gedankenexperiment.

    Science.gov (United States)

    Ivanov, Konstantin L; Bodenhausen, Geoffrey

    2018-07-01

    A novel conceptual approach is described that is based on the transfer of hyperpolarization from para-hydrogen in view of generating a population imbalance between the two spin isomers of H 2 O. The approach is analogous to SABRE (Signal Amplification By Reversible Exchange) and makes use of the transfer of spin order from para-hydrogen to H 2 O in a hypothetical organometallic complex. The spin order transfer is expected to be most efficient at avoided level crossings. The highest achievable enrichment levels of para- and ortho-water are discussed. Copyright © 2018 Elsevier Inc. All rights reserved.

  4. Intraoperative radiation in the canine para-aortic abdomen

    International Nuclear Information System (INIS)

    Hoopes, P.J.; Gillette, E.L.

    1984-01-01

    Twenty adult beagle dogs received intraoperatively delivered 6 MeV electrons to the para-aortic abdomen and bladder. The dogs were equally divided into 4 dose groups receiving 22 Gy, 30 Gy, 38.5 Gy and 47 Gy. The 5 cm x 8 cm radiation field included a variable portion of the left kidney, the left ureter, the abdominal aorta and vena cava, the base of the bladder and the left sciatic and femoral nerves. The lesions observed were fibroelastic proliferation of the aortic intima, severe renal atrophy and fibrosis, ureteral stenosis, bladder fibrosis and demyelinating peripheral neuropathies. Histologic, morphometric and dose response analyses are compared with responses of dogs receiving more conventional fractionated doses to a total of 60 Gy, 70 Gy or 80 Gy x-ray in 6 weeks

  5. Evaluation of a pyrex glass shield for the dose reduction in extremities to manipulate a {sup 90} Sr- {sup 90} Y generator; Evaluacion de un blindaje de vidrio pyrex para la reduccion de las dosis en extremidades al manipular un generador de {sup 90} Sr- {sup 90} Y

    Energy Technology Data Exchange (ETDEWEB)

    Ayra P, F.E.; Xiques C, A.; Torres B, M.B. [Centro de Isotopos, Carretera La Rada, Km 3 1/2, Guanabacoa, La Habana (Cuba)]. e-mail: feayra@centis.edu.cu

    2006-07-01

    The production of Y-90 of high activity it specifies (free of payee) for their use in radioimmunotherapy uses the Strontium 90 as isotope source. Depending on the method employee for the separation of both isotopes several types of generators are described in different bibliographies. The column generator used in the facilities of the Center of Isotopes requires of a frequent manipulation causing significant dose in the skin of the extremities due to the exhibition to the radiation beta of high energy. The properties of the shieldings for this radiation type have been well studied Y they consist in several publications. To be in correspondence with requirements of radiological protection in the Cuban legislation, the column was covered with a tube of glass pyrex of 5 mm of thickness and it was monitored the exposure with an ionization chamber. At the own time, the shielding using the Monte Carlo method was evaluated. It was used the MCNP 4C code to simulate the absorption of the beta particles generated in the process of disintegration of the Sr-90 and Y-90 in the glass shielding. The column generator and the fluence of beta particles were modeled in different points inside the shielding to determine if the experimentally measured values correspond to electrons that were not absorbed or to the weak stopping radiation generated in the glass due to the deceleration of these particles. A cylinder of 4 mm of diameter simulates the source (it dilutes) and a tube of walls of 6 mm of thickness simulates the shielding more the wall of the column around the generator. This it was divided in cells of 1 mm of thickness and the energy deposited in them was evaluated. The results show that all the electrons generated in the source are absorbed in the shielding and the exposure rates decrease in more of 78 times using the 5 mm of pyrex glass. The doses in extremities to the operators of the generator don't surpass the 70 mSv by year that is the dose restriction imposed in

  6. New recommendations for dose equivalent

    International Nuclear Information System (INIS)

    Bengtsson, G.

    1985-01-01

    In its report 39, the International Commission on Radiation Units and Measurements (ICRU), has defined four new quantities for the determination of dose equivalents from external sources: the ambient dose equivalent, the directional dose equivalent, the individual dose equivalent, penetrating and the individual dose equivalent, superficial. The rationale behind these concepts and their practical application are discussed. Reference is made to numerical values of these quantities which will be the subject of a coming publication from the International Commission on Radiological Protection, ICRP. (Author)

  7. Para compreender a ciberliteratura

    Directory of Open Access Journals (Sweden)

    Lucia Santaella

    2012-12-01

    Full Text Available http://dx.doi.org/10.5007/1807-9288.2012v8n2p229   Mediante as mídias digitais, a configuração da literatura sofreu um salto qualitativo em todos os seus aspectos. O espaço virtual gerado pelas redes de computadores funciona como um novo meio. Abre-se com ele uma miríade de oportunidades que expandem o conceito de literatura em função da emergência de novas formas de criação literária. Disso decorre que a criação, a teoria e a crítica literárias exigem a redefinição de seus paradigmas herdados da era de Gutenberg. Tendo isso em vista, este artigo está voltado para a construção textual e hipertextual no espaço digital, o que implica uma exploração do que é ciberliteratura, em que ela se cruza e em que diverge da literatura impressa, que estratégias significantes a caracterizam e como essas estratégias são interpretadas pelos usuários na sua busca de significado.

  8. para promover la salud

    Directory of Open Access Journals (Sweden)

    Ma. del Consuelo Chapela

    2002-01-01

    Full Text Available Hablar de educación a distancia sustentada en el desarrollo de la cibernética obliga a reflexionar sobre sus definiciones, objetivos y medios, especialmente si pensamos en las necesidades de la fracción de población que no tiene acceso a las posibilidades que ofrece el desarrollo tecnológico. En este trabajo se presenta e ilustra con un ejemplo práctico, una perspectiva sobre las posibilidades de la educación a distancia desde las necesidades de la promoción de la salud entre grupos de población marginada en el mundo virtual. Se propone la creación de bibliotecas itinerantes regionales que pongan a disposición de la población con acceso limitado a la información, la tecnología comunicativa necesaria para apoyar los trabajos de promoción de la salud.

  9. Dose estimate for effective internal contamination in the occupationally exposed workers(OEW) that handling open sources for thyroid therapy using {sup 131} I (3779); Estimacion de la dosis efectiva por contaminacion interna en los trabajadores ocupacionalmente expuestos (TOE) que manipulan fuentes abiertas para el tratamiento de tiroides con {sup 131}I (3779)

    Energy Technology Data Exchange (ETDEWEB)

    Lecuna, J.A.; Carrizales, L.I., E-mail: jj1211g@yahoo.com, E-mail: lcarriza@ivic.gob.ve [Instituto Venezolano de Investigaciones Cientificas (IVIC), Caracas (Venezuela, Bolivarian Republic of); Dantas, B.M., E-mail: bmdantas@ird.gov.br [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2013-11-01

    Handling of a variety of unsealed sources in Nuclear Medicine has led a significant risk of internal exposure of workers. {sup 131}I stands out among the radionuclides of frequent use due its wide application in diagnosis and treatment of thyroid diseases. The increasing radionuclide use for medical purposes and treatment of diseases creates a need for capable methodologies of controlling the internal contamination of work. Currently, in Venezuela, there are about 17 Nuclear Medicine Services between public and private, of which 5 are operating; however, individual monitoring is still limited in the control of internal exposure. This work presents the development of bioassay techniques 'in vivo', in order to quantify the incorporation of {sup 131}I used in Nuclear Medicine. It also presents the research results of internal exposure of a group of workers involved in handling of therapeutic dose of {sup 131}I . The 'in vivo' detection system was calibrated with the thyroid simulator developed at the Institute of Radiologic Protection and Dosimetry (IRD, Rio de Janeiro - Brazil) and which also has the UTN-IVIC (Caracas - Venezuela). The results showed that the bioassay method developed in this work has sufficient sensitivity for its use in routine intake survey of workers in Nuclear Medicine. Between the two workers controlled in this study, both had measurable results in terms of incorporation. Therefore, it is important to keep control of it and also gives us the possibility to evaluate the incorporations in suspected accident. The highest estimate of the effective dose was 1,28x10{sup -5} Sv by inhalation and 1,27x10{sup -5} Sv by ingestion.

  10. Para-equilibrium phase diagrams

    International Nuclear Information System (INIS)

    Pelton, Arthur D.; Koukkari, Pertti; Pajarre, Risto; Eriksson, Gunnar

    2014-01-01

    Highlights: • A rapidly cooled system may attain a state of para-equilibrium. • In this state rapidly diffusing elements reach equilibrium but others are immobile. • Application of the Phase Rule to para-equilibrium phase diagrams is discussed. • A general algorithm to calculate para-equilibrium phase diagrams is described. - Abstract: If an initially homogeneous system at high temperature is rapidly cooled, a temporary para-equilibrium state may result in which rapidly diffusing elements have reached equilibrium but more slowly diffusing elements have remained essentially immobile. The best known example occurs when homogeneous austenite is quenched. A para-equilibrium phase assemblage may be calculated thermodynamically by Gibbs free energy minimization under the constraint that the ratios of the slowly diffusing elements are the same in all phases. Several examples of calculated para-equilibrium phase diagram sections are presented and the application of the Phase Rule is discussed. Although the rules governing the geometry of these diagrams may appear at first to be somewhat different from those for full equilibrium phase diagrams, it is shown that in fact they obey exactly the same rules with the following provision. Since the molar ratios of non-diffusing elements are the same in all phases at para-equilibrium, these ratios act, as far as the geometry of the diagram is concerned, like “potential” variables (such as T, pressure or chemical potentials) rather than like “normal” composition variables which need not be the same in all phases. A general algorithm to calculate para-equilibrium phase diagrams is presented. In the limit, if a para-equilibrium calculation is performed under the constraint that no elements diffuse, then the resultant phase diagram shows the single phase with the minimum Gibbs free energy at any point on the diagram; such calculations are of interest in physical vapor deposition when deposition is so rapid that phase

  11. Integral dose conservation in radiotherapy

    International Nuclear Information System (INIS)

    Reese, Adam S.; Das, Shiva K.; Curle, Charles; Marks, Lawrence B.

    2009-01-01

    Treatment planners frequently modify beam arrangements and use IMRT to improve target dose coverage while satisfying dose constraints on normal tissues. The authors herein analyze the limitations of these strategies and quantitatively assess the extent to which dose can be redistributed within the patient volume. Specifically, the authors hypothesize that (1) the normalized integral dose is constant across concentric shells of normal tissue surrounding the target (normalized to the average integral shell dose), (2) the normalized integral shell dose is constant across plans with different numbers and orientations of beams, and (3) the normalized integral shell dose is constant across plans when reducing the dose to a critical structure. Using the images of seven patients previously irradiated for cancer of brain or prostate cancer and one idealized scenario, competing three-dimensional conformal and IMRT plans were generated using different beam configurations. Within a given plan and for competing plans with a constant mean target dose, the normalized integral doses within concentric ''shells'' of surrounding normal tissue were quantitatively compared. Within each patient, the normalized integral dose to shells of normal tissue surrounding the target was relatively constant (1). Similarly, for each clinical scenario, the normalized integral dose for a given shell was also relatively constant regardless of the number and orientation of beams (2) or degree of sparing of a critical structure (3). 3D and IMRT planning tools can redistribute, rather than eliminate dose to the surrounding normal tissues (intuitively known by planners). More specifically, dose cannot be moved between shells surrounding the target but only within a shell. This implies that there are limitations in the extent to which a critical structure can be spared based on the location and geometry of the critical structure relative to the target.

  12. Marcadores para la Realidad Aumentada para fines educativos

    Directory of Open Access Journals (Sweden)

    María Reina Zarate Nava

    2013-12-01

    Full Text Available La Realidad Aumentada (AR es considerada por algunos expertos como la tecnología en crecimiento para el 2014, en diferentes sectores: ingeniería, educación, juegos y negocios, siendo este último el más usado en él 2013. Sin embargo en el sector educativo la AR se presenta en algunos proyectos que se han desarrollado para diferentes áreas de las ciencias, como Química, Física y Matemáticas, lo anterior con el objetivo de facilitar el proceso de Enseñanza-Aprendizaje. En el presente artículo se presenta el modelo de patrones utilizado para un Proyecto AR enfocado en Química, el cual presenta un conjunto de patrones que fueron valorados para facilitar el rastreo de los objetos y a su vez el entendimiento de algunos materiales de los laboratorios de Química I.

  13. Algoritmos para problemas de empacotamento

    OpenAIRE

    Eduardo Candido Xavier

    2006-01-01

    Resumo: Neste trabalho estudamos diversos problemas de empacotamento considerados NP-difíceis. Assumindo a hipótese de que P ? NP, sabemos que não existem algoritmos eficientes (complexidade de tempo polinomial) exatos para resolver tais problemas. Uma das abordagens consideradas para tratar tais problemas é a de algoritmos de aproximação, que são algoritmos eficientes e que geram soluções com garantia de qualidade. Neste trabalho apresentamos alguns algoritmos aproximados para problemas de e...

  14. Teores proteicos em dietas para vacas Holandesas leiteiras em confinamento

    Directory of Open Access Journals (Sweden)

    V.R. Paiva

    2013-08-01

    Full Text Available Avaliou-se o efeito de dietas com níveis de proteína bruta ‒ PB (10, 12, 14 e 16% na matéria seca ‒ MS em vacas Holandesas mestiças com produção de leite médio (PL de 13kg/dia. Utilizou-se silagem de milho como volumoso, e a relação volumoso:concentrado foi de 75:25. Houve aumento linear para o consumo de todos os componentes da dieta, exceto para o consumo de carboidratos totais e carboidratos não fibrosos (CNF, que reduziram linearmente. O consumo dos nutrientes digestíveis totais (NDT apresentou comportamento quadrático, com valor máximo estimado de 10,13kg/dia, na dose de 15,62% de PB na dieta. As digestibilidades de PB, EE, FDN e FDNcp aumentaram linearmente. Já os valores de digestibilidade de MS, MO, CNF e NDT apresentaram efeito quadrático, estimando-se ponto de máximo de 65,09; 67,23; 78,35 e 67,92 nas doses de 15,39; 15,22; 15,62 e 15,68% de PB, respectivamente. A PL, sem e com correção para 3,5% de gordura, a variação de peso corporal e a composição do leite aumentaram linearmente, exceto para lactose, que não apresentou efeito. O nível de 14% de PB na dieta é o mais indicado para alimentação de vacas com produção média de 13kg/dia de leite.

  15. Estudo do momento ótimo de reforma para povoamentos de Eucalyptus spp - o caso da redução dos custos.

    Directory of Open Access Journals (Sweden)

    Álvaro Nogueira de Souza

    2010-08-01

    Full Text Available Os objetivos deste trabalho foram: a propor e verificar a eficiência de um modelo matemático que permita estudar os efeitos do progresso tecnológico (redução dos custos sobre a época ótima de substituir povoamentos de Eucalyptus spp; b determinar a rotação florestal de um povoamento de Eucalyptus spp; c verificar qual seria o momento de substituir se as receitas estivessem constantes desde o início dos incentivos fiscais, ou seja, na década de 60, e, d projetar o momento de substituir o povoamento no futuro, considerando os custos decrescentes e a produtividade constante a valores de hoje. Utilizou-se a Função Gompertz para o cálculo da produção de madeira. O critério utilizado para a avaliação econômica da viabilidade dos projetos foi o Valor Presente Líquido. O modelo proposto permitiu calcular o efeito do progresso tecnológico nos custos no período entre 1960 e 2000 e projetar os valores dos custos para o período entre 2000 e 2040. Concluiu-se que: a a rotação, com valores atuais, encontra-se, em 7 anos, mantidas as receitas da década de 60; b o momento ótimo de reforma estaria em seis cortes; c o modelo mostrou-se eficiente para estimativas em um horizonte de até 40 anos; o estudo da cadeia de substituição mostrou que as épocas ótimas de reforma caíram ao longo dos anos, de seis cortes na década de 60, três na década de 80 e dois atualmente; a tendência é permanecer nos dois cortes passando a três com um pequeno aumento na produtividade das talhadias.

  16. Patient dose measurement and dose reduction in East Anglia (UK)

    International Nuclear Information System (INIS)

    Wade, J.P.; Goldstone, K.E.; Dendy, P.P.

    1995-01-01

    At the end of 1990 a programme of patient dose measurements was introduced as part of the quality assurance service already provided for X ray departments throughout the East Anglian Health Region (UK). Thermoluminescence dosemeters (TLDs) were used to measure over 1200 skin entrance surface doses for four common radiographic views in 33 hospitals in both the NHS and private sector. The four views were chosen to cover a wide range of equipment and techniques. The data collected have enabled Regional reference doses to be set which, for all views considered, fall below the National Radiological Protection Board (NRPB) Reference levels. In departments which exceeded reference levels, techniques were reviewed, improvements suggested and doses re-measured, in accordance with the recommended procedure for patient dose audit. A significant finding was that, given appropriate controls, X ray departments in the private sector could achieve the same acceptably low doses as NHS departments. (Author)

  17. The Importance of Dosimetry to the Medical Management of Persons Accidentally Exposed to High Levels of Radiation; Le Role de la Dosimetrie Dans les Soins Medicaux a Donner aux Personnes Accidentellement Exposees a de Fortes Doses de Rayonnement; 0417 041d 0410 0427 0414 ; Importancia de la Dosimetria para el Tratamiento Medico de las Personas Accidentalmente Expuestas a Dosis Elevadas de Radiaciones

    Energy Technology Data Exchange (ETDEWEB)

    Andrews, G. A.; Lushbaugh, C. C. [Medical Division, Oak Ridge Institute of Nuclear Studies (United States); Auxier, J. A. [Health Physics Division, Oak Ridge National Laboratory, Oak Ridge, TN (United States)

    1965-06-15

    Radiation accidents continue to occur sporadically and it appears that there is no hope of eliminating them entirely. The management of patients exposed to large doses of radiation is constantly improving because of increasing ability to prevent and treat infection and to control haemorrhage. The possible effectiveness of temporary bone marrow grafts offers promise of a further reduction in mortality. The use of this growing biological information is closely related to, and to a large extent dependent upon, improvements in physical dosimetry for radiation accidents. (author) [French] Des accidents provoques par les rayonnements continuent a se produire de temps a autre et il ne semble guere que l'on puisse esperer les eliminer entierement. Toutefois, le traitement des sujets exposes a de fortes doses de rayonnement ne cesse de s'ameliorer; on parvient, en effet, dans une mesure croissante a empecher et a traiter l*infection ainsi qu'a arreter l'hemorragie. Comme la greffe temporaire de la moelle des os semble devoir donner des resultats, on peut s*attendre a une nouvelle reduction du taux de mortalite. L'application de ces connaissances biologiques sans cesse accrues est fonction, dans une large mesure, des ameliorations apportees a la dosimetrie physique des accidents nucleaires. (author) [Spanish] De vez en cuando se siguen produciendo accidentes de irradiacion y las perspectivas de evitarlos por completo parecen ser bastante remotas. El tratamiento de las victimas expuestas a dosis elevadas de radiaciones mejora constantemente debido a la creciente posibilidad de prevenir y tratar las infecciones, y de controlar las hemorragias. Tambien es posible que la eficacia de ios injertos temporales de medula osea se traduzca en una disminucion de la mortalidad. El aprovechamiento de estos conocimientos biologicos cada vez mas amplios guarda una estrecha relacion con los perfeccionamientos en materia de dosimetria fisica en caso de accidentes de irradiacion. (author

  18. Efeito de diferentes doses de flavonóides em ratos hiperlipidêmicos

    Directory of Open Access Journals (Sweden)

    OLIVEIRA Tania Toledo de

    2002-01-01

    Full Text Available O objetivo deste estudo foi avaliar o efeito de diferentes doses de baicaleína, morina, naringenina, naringina, quercetina e rutina no aumento dos níveis de colesterol-HDL e trigliceróis em ratos hiperlipidêmicos. Tais flavonóides foram administrados em 3 doses (5, 10, 15 mg/animal a ratos machos da raça Wistar, com 30 dias de vida, alimentados com dieta não purificada de fórmula da marca Labina®. A hiperlipidemia foi induzida pela administração de Triton, na dose de 300 mg/kg de peso vivo. Após 24 horas, os flavonóides foram administrados, sendo cada dose aplicada em grupos de 8 animais. Após 48 horas da aplicação do Triton, os animais foram anestesiados e, por punção cardíaca, amostras de sangue foram coletadas para realização das análises de colesterol, colesterol-HDL e triacilgliceróis no soro. Os melhores resultados para a redução do colesterol foram obtidos com os flavonóides quercetina e rutina, na dose de 5 mg, e naringenina, na dose de 10 mg. A baicaleína, nas doses de 5 e 10 mg, foi a que apresentou as menores reduções para colesterol-HDL. Já para as concentrações de triacilgliceróis, a baicaleína foi a que mais reduziu este parâmetro, independentemente da dose utilizada.

  19. Sistema de geoespacialização da demanda de irrigação suplementar para o Estado de Minas Gerais I: descrição Geospatialization system for demand of supplementary irrigation in the State of Minas Gerais I: description

    Directory of Open Access Journals (Sweden)

    Marcos O. Santana

    2003-04-01

    Full Text Available Com este trabalho objetivou-se desenvolver um sistema automático e monitorado de regionalização da demanda de irrigação suplementar das principais culturas irrigadas no Estado de Minas Gerais, disponibilizando tais informações via rede mundial de computadores (Internet com três atualizações semanais. O sistema, denominado IRGNET, utiliza dados de estações climáticas automáticas do Instituto Nacional de Pesquisas Espaciais (INPE para estimativa da perda de água pela cultura por evapotranspiração e a reposição da água no solo, pela precipitação. Utilizou-se um sistema de informações geográficas para espacializar e gerar mapas temáticos de evapotranspiração de referência e de precipitação diária do Estado e se desenvolveu um programa computacional para calcular o balanço hídrico e determinar a lâmina de irrigação para qualquer localidade do Estado.This study had the aim to develop an automatic and controlled system of regionalized supplemental irrigation demand for the main irrigated crops in the State of Minas Gerais by providing this information three times a week by the World Wide Web (Internet. The socalled IRGNET system uses data collected by automatic weather stations belonging to the National Institute for Space Research (INPE for the assessment of water loss in crop evapotranspiration and also the water supply by rainfall. A geographic information system was used to spatialize and create thematic maps about crop evapotranspiration and daily rainfall in the State. A computer program was also developed to calculate the soil water balance and to determine the irrigation water depth for any place within the State.

  20. Seletividade de herbicidas para cebola em semeadura direta Selectivity of herbicides for onions in direct sowing

    Directory of Open Access Journals (Sweden)

    Lino R. Ferreira

    1999-04-01

    Full Text Available As plantas de cebola provenientes da semeadura direta, têm-se mostrado muito sensíveis aos herbicidas recomendados para a cultura transplantada, principalmente aqueles com ação sobre plantas daninhas dicotiledôneas. Os efeitos do fracionamento da dose dos herbicidas oxyfluorfen, ioxynil-octanoato, fluazifop-p-butil e sethoxydim foram avaliados em dois cultivares (Granex Ouro e Granex 33, no sistema de semeadura direta. A tolerância dos dois cultivares ao oxyfluorfen e ao ioxynil-octanoato aumentou com a idade das plantas e com o parcelamento das doses, aplicando-se doses menores no estádio de duas folhas. Sethoxydim e fluazifop-p-butil foram seletivos para a cultura, independente da dose inicial aplicada e do cultivar avaliado.The plants of onions, from direct sowing, have shown to be quite sensitive toward herbicides recommended for transplanted culture, especially those acting on dycotiledoneous weeds. The effects of dose fractionating of herbicides oxyfluorfen, ioxynil-octanoato, fluazifop-p-butil and sethoxydim were evaluated in two cultivars (Granex Ouro and Granex 33, in the direct sowing system. The tolerance of the two cultivars toward oxyfluorfen and ioxynyl-octanoato increased with the plants age and with the parceling of the doses, applying smaller doses in the two leaves stage. Sethoxydim and fluazifop-p-butyl were selective for the culture, regardless of the applied initial doses and the evaluated cultivar.

  1. In defence of collective dose

    International Nuclear Information System (INIS)

    Fairlie, I.; Sumner, D.

    2000-01-01

    Recent proposals for a new scheme of radiation protection leave little room for collective dose estimations. This article discusses the history and present use of collective doses for occupational, ALARA, EIS and other purposes with reference to practical industry papers and government reports. The linear no-threshold (LNT) hypothesis suggests that collective doses which consist of very small doses added together should be used. Moral and ethical questions are discussed, particularly the emphasis on individual doses to the exclusion of societal risks, uncertainty over effects into the distant future and hesitation over calculating collective detriments. It is concluded that for moral, practical and legal reasons, collective dose is a valid parameter which should continue to be used. (author)

  2. Fast in vivo volume dose reconstruction via reference dose perturbation

    International Nuclear Information System (INIS)

    Lu, Weiguo; Chen, Mingli; Mo, Xiaohu; Parnell, Donald; Olivera, Gustavo; Galmarini, Daniel

    2014-01-01

    Purpose: Accurate on-line reconstruction of in-vivo volume dose that accounts for both machine and patient discrepancy is not clinically available. We present a simple reference-dose-perturbation algorithm that reconstructs in-vivo volume dose fast and accurately. Methods: We modelled the volume dose as a function of the fluence map and density image. Machine (output variation, jaw/leaf position errors, etc.) and patient (setup error, weight loss, etc.) discrepancies between the plan and delivery were modelled as perturbation of the fluence map and density image, respectively. Delivered dose is modelled as perturbation of the reference dose due to change of the fluence map and density image. We used both simulated and clinical data to validate the algorithm. The planned dose was used as the reference. The reconstruction was perturbed from the reference and accounted for output-variations and the registered daily image. The reconstruction was compared with the ground truth via isodose lines and the Gamma Index. Results: For various plans and geometries, the volume doses were reconstructed in few seconds. The reconstruction generally matched well with the ground truth. For the 3%/3mm criteria, the Gamma pass rates were 98% for simulations and 95% for clinical data. The differences mainly appeared on the surface of the phantom/patient. Conclusions: A novel reference-dose-perturbation dose reconstruction model is presented. The model accounts for machine and patient discrepancy from planning. The algorithm is simple, fast, yet accurate, which makes online in-vivo 3D dose reconstruction clinically feasible.

  3. Experimental evaluation of neutron dose in radiotherapy patients: Which dose?

    Energy Technology Data Exchange (ETDEWEB)

    Romero-Expósito, M., E-mail: mariateresa.romero@uab.cat; Domingo, C.; Ortega-Gelabert, O.; Gallego, S. [Grup de Recerca en Radiacions Ionizants (GRRI), Departament de Física, Universitat Autònoma de Barcelona, Bellaterra 08193 (Spain); Sánchez-Doblado, F. [Departamento de Fisiología Médica y Biofísica, Universidad de Sevilla, Sevilla 41009 (Spain); Servicio de Radiofísica, Hospital Universitario Virgen Macarena, Sevilla 41009 (Spain)

    2016-01-15

    Purpose: The evaluation of peripheral dose has become a relevant issue recently, in particular, the contribution of secondary neutrons. However, after the revision of the Recommendations of the International Commission on Radiological Protection, there has been a lack of experimental procedure for its evaluation. Specifically, the problem comes from the replacement of organ dose equivalent by the organ-equivalent dose, being the latter “immeasurable” by definition. Therefore, dose equivalent has to be still used although it needs the calculation of the radiation quality factor Q, which depends on the unrestricted linear energy transfer, for the specific neutron irradiation conditions. On the other hand, equivalent dose is computed through the radiation weighting factor w{sub R}, which can be easily calculated using the continuous function provided by the recommendations. The aim of the paper is to compare the dose equivalent evaluated following the definition, that is, using Q, with the values obtained by replacing the quality factor with w{sub R}. Methods: Dose equivalents were estimated in selected points inside a phantom. Two types of medical environments were chosen for the irradiations: a photon- and a proton-therapy facility. For the estimation of dose equivalent, a poly-allyl-diglicol-carbonate-based neutron dosimeter was used for neutron fluence measurements and, additionally, Monte Carlo simulations were performed to obtain the energy spectrum of the fluence in each point. Results: The main contribution to dose equivalent comes from neutrons with energy higher than 0.1 MeV, even when they represent the smallest contribution in fluence. For this range of energy, the radiation quality factor and the radiation weighting factor are approximately equal. Then, dose equivalents evaluated using both factors are compatible, with differences below 12%. Conclusions: Quality factor can be replaced by the radiation weighting factor in the evaluation of dose

  4. Angular dependence of shallow dose

    International Nuclear Information System (INIS)

    Alvarez, J.L.

    1986-01-01

    The theoretical response of a detector is discussed and compared to measurements of shallow dose with tissue and phantom response detectors. A definite energy dependent angular response of dose and measurement was observed which could not be explained by simple trigonometric arguments. The response is back scatter dependent and must be considered in detector design and dose measurements. It is not possible for standard detectors to follow this response

  5. Full dose CHOP chemotherapy

    International Nuclear Information System (INIS)

    Tominaga, Shinichi; Kondo, Makoto; Ando, Yutaka; Yamashita, Shoji; Uematsu, Minoru; Shigematsu, Naoyuki; Nishiguchi, Iku; Hashimoto, Shozo

    1985-01-01

    Since 1982, we have performed 125 courses of CHOP chemotherapy for 27 patients of malignancy, adhering to the original regimen as strictly as possible. CHOP chemotherapy consisted of Cyclophosphamide 750 mg/m 2 , iv, on day 1; Adriamycin 50 mg/m 2 , iv, on day 1; Vincristine 1.4 mg/m 2 , iv, on day 1 (maximum single dose 2.0 mg) and Prednisolone 50 mg/m 2 , po, day 1 through 5. The cycle was repeated every 21 days. As side effects, myelosuppression, hair loss, fever, nausea, vomiting, liver dysfunction, stomatitis, neuropathy, herpes zoster, arrhythmia and hemorrhagic cystitis were seen. Due to myelosuppression, twenty patients experienced febrile episodes at each nadir of WBC counts on 40 courses. However, any febrile patient did not have life threatening infection. Other side effects were also reversible. The radiotherapy of most patients was carried out as initially scheduled, except for 3 patients in whom irradiation was interrupted due to severe stomatitis or herpes zoster. We consider that CHOP chemotherapy is excellent in feasibility even when combined with radiotherapy. (author)

  6. Mobilização corporal para prevenção de úlceras por pressão: custo direto com pessoal

    Directory of Open Access Journals (Sweden)

    Antônio Fernandes Costa Lima

    2015-10-01

    Full Text Available RESUMOObjetivo:calcular o custo total médio (CTM relativo à mão de obra direta (MOD de profissionais de enfermagem para a mobilização corporal de pacientes visando à prevenção de úlceras por pressão.Método:estudo de caso quantitativo, exploratório-descritivo. Observou-se a realização de 656 mobilizações preventivas e calculou-se o custo multiplicando-se o tempo despendido pelos profissionais pelo custo unitário da MOD.Resultados:o CTM com MOD por Unidade correspondeu a: Clínica Médica R$ 5,38 por mudança de decúbito, R$ 5,26 por posicionamento em poltrona, R$ 5,55 por auxílio deambulação; Clínica Cirúrgica R$ 2,42 por mudança de decúbito, R$ 2,30 por posicionamento em poltrona, R$ 2,96 por auxílio deambulação e Unidade de Terapia Intensiva R$ 8,15 por mudança de decúbito, R$ 7,57 por posicionamentos em poltrona, R$ 15,32 por auxílio deambulação.Conclusão:o conhecimento gerado poderá subsidiar o gerenciamento de custos relacionados aos recursos humanos necessários ao cuidado de enfermagem eficiente e eficaz.

  7. Programa para la ejecución de la reconfiguración de alimentadores de distribución primaria

    Directory of Open Access Journals (Sweden)

    Yoel R Rosales Hernández

    2011-02-01

    Full Text Available La reconfiguración en las redes de distribución primaria se ejecuta mediante la operación de interruptoresnormalmente abiertos y normalmente cerrados, manteniendo siempre una topología radial, y uno de susobjetivos es disminuir las pérdidas totales de la red donde se aplique. Se presenta un programa endesarrollo con una interfaz muy amigable y funciones que permiten calcular la reconfiguración óptima paraalcanzar el estado de pérdidas mínimas en cualquier circuito de distribución primaria modelado. Su algoritmode cálculo está basado en un método heurístico muy sencillo y atractivo para programar, el lenguaje deprogramación utilizado es el Borland Delphi versión 5. Este resultado puede constituir una útil herramientapara el estudio de las redes primarias durante su planificación y explotación.  The reconfiguration of primary distribution networks is run by means of normally open and normally closedswitches. It keeps radial topology and aims at lowering losses on the network where it is being run. Thispaper includes an undergoing program which has an interactive interface and functions enabling an optimumreconfiguration. This program allows to know the minimum losses at any represented primary distributioncircuit and may become a useful tool for the study of primary networks being planned or used. Its calculationalgorithm is based on an easy-to-program heuristic method. The programming language used was BorlandDelphi 5.

  8. El juego como vehículo para mejorar las habilidades de lectura en niños con dificultad lectora

    Directory of Open Access Journals (Sweden)

    Natalia Cadavid Ruiz

    2014-01-01

    Full Text Available A partir de las escasas propuestas de intervención de la lectura en población infantil colombiana, el presente estudio tiene por objetivo evaluar el impacto de un programa de intervención de la lectura, centrado en juego y aprendizaje implícito, sobre el desempeño lector en niños con dificultades lectoras, inmediatamente después y seis meses posteriores a la aplicación del programa. Método. Por medio de un diseño cuasi - experimental, transversal y comparativo, se evaluaron 20 niños, entre los 7 y 9 años de edad, con un desarrollo psicológico típico, quienes asistían regularmente a un colegio público de la ciudad de Cali (Colombia. Las evaluaciones pre y post incluyeron la aplicación de pruebas que exploran conciencia fonológica, capacidad lectora y rendimiento cognitivo general. Estos datos se emplearon para calcular diferencias entre los desempeños de los niños, obtenidos en la preintervención, posintervención inmediata y a largo plazo. Resultados. Los datos recogidos demostraron que los niños mejoran significativamente su rendimiento lector inmediatamente después de la aplicación del programa, con un efecto que se mantiene a largo plazo. Conclusión. Las dificultades lectoras que presentan los niños participantes pueden mejorarse con la aplicación de un programa de intervención de la lectura, centrado en el juego y aprendizaje implícito.

  9. Radiation dose in dental radiology

    International Nuclear Information System (INIS)

    Cohnen, M.; Kemper, J.; Moedder, U.; Moebes, O.; Pawelzik, J.

    2002-01-01

    The aim of this study was to compare radiation exposure in panoramic radiography (PR), dental CT, and digital volume tomography (DVT). An anthropomorphic Alderson-Rando phantom and two anatomical head phantoms with thermoluminescent dosimeters fixed at appropriate locations were exposed as in a dental examination. In PR and DVT, standard parameters were used while variables in CT included mA, pitch, and rotation time. Image noise was assessed in dental CT and DVT. Radiation doses to the skin and internal organs within the primary beam and resulting from scatter radiation were measured and expressed as maximum doses in mGy. For PR, DVT, and CT, these maximum doses were 0.65, 4.2, and 23 mGy. In dose-reduced CT protocols, radiation doses ranged from 10.9 to 6.1 mGy. Effective doses calculated on this basis showed values below 0.1 mSv for PR, DVT, and dose-reduced CT. Image noise was similar in DVT and low-dose CT. As radiation exposure and image noise of DVT is similar to low-dose CT, this imaging technique cannot be recommended as a general alternative to replace PR in dental radiology. (orig.)

  10. Hanford Environmental Dose Reconstruction Project

    International Nuclear Information System (INIS)

    Finch, S.M.; McMakin, A.H.

    1991-04-01

    The objective of the Hanford Environmental Dose Reconstruction Project is to estimate the radiation doses that populations could have received from nuclear operations at Hanford since 1944. The project is being managed and conducted by the Pacific Northwest Laboratory (PNL) under the direction of an independent Technical Steering Panel (TSP). The project is divided into the following technical tasks. These tasks correspond to the path radionuclides followed, from released to impact on humans (dose estimates): source terms; environmental transport; environmental monitoring data; demographics, agriculture, food habits; and, environmental pathways and dose estimates

  11. Occupational dose trends in Tanzania

    International Nuclear Information System (INIS)

    Muhogora, W.E.; Nyanda, A.M.; Ngaile, J.E.; Lema, U.S.

    1998-01-01

    This paper describes the present status of occupational radiation exposure of monitored workers in Tanzania from 1986 to 1997. The analysis of dose records observes over this period, a fluctuating trend both in the individual and collective doses. The trend is more related to the fluctuations of the number of radiation workers than to the possible radiation safety changes of the working conditions. It has been found that, the maximum annual dose for the worker in all work categories was about 18 mSv y -1 . This suggests that the occupational radiation exposure in all practices satisfies the current dose limitation system. The national exposure summary shows that, the highest collective dose of 12.8 man-Sv which is 90% of the total collective dose, was due to medical applications. The applications in industry and research had a contribution of nearly 0.8 and 0.7 man-Sv respectively. From the professional point of view, the medical diagnostic radiographers received the highest collective dose of 11.2 man-Sv. Although the medical physicists recorded the minimum collective dose of nearly 0.07 man-Sv, the data shows that this profession received the highest mean dose of about 33 mSv in 12 years. Some achievements of the personnel monitoring services and suggestions for future improvement are pointed out. (author)

  12. Prenatal radiation doses from radiopharmaceuticals

    International Nuclear Information System (INIS)

    Rojo, A.M.; Gomez Parada, I.M.; Di Trano, J.L.

    1998-01-01

    The radiopharmaceutical administration with diagnostic or therapeutic purpose during pregnancy implies a prenatal radiation dose. The dose assessment and the evaluation of the radiological risks become relevant due to the great radiosensitivity of the fetal tissues in development. This paper is a revision of the available data for estimating fetal doses in the cases of the more frequently used radiopharmaceuticals in nuclear medicine, taking into account recent investigation in placental crossover. The more frequent diagnostic and therapeutic procedures were analyzed according to the radiation doses implied. (author) [es

  13. Hanford Environmental Dose Reconstruction Project

    International Nuclear Information System (INIS)

    Finch, S.M.; McMakin, A.H.

    1992-06-01

    The objective of the Hanford Environmental Dose Reconstruction Project is to estimate the radiation doses that individuals and populations could have received from nuclear operations at Hanford since 1944. The project is being managed and conducted by the Battelle Pacific Northwest Laboratories under contract with the Centers for Disease Control. The independent Technical Steering Panel (TSP) provides technical direction. The project is divided into the following technical tasks. These tasks correspond to the path radionuclides followed, from release to impact on humans (dose estimates): source terms; environmental transport; environmental monitoring data; demography, food consumption, and agriculture; environmental pathways and dose estimates

  14. Radiation doses in interventional neuroradiology

    International Nuclear Information System (INIS)

    Theodorakou, C.; Butler, P.; Horrocks, J.A.

    2001-01-01

    Patient radiation doses during interventional radiology (IR) procedures may reach the thresholds for radiation-induced skin and eye lens injuries. This study investigates the radiation doses received by patients undergoing cerebral embolization. Measurements were conducted using thermoluminescent dosimeters. Radiotherapy verification films were used in order to visualise the radiation field. For each procedure the fluoroscopic and digital dose-area product, the fluoroscopic time, the total number of acquired images and entrance-skin dose calculated by the angiographic unit were recorded. In this paper, the skin, eye and thyroid glands doses on a sample of patients are presented. From a preliminary study of 13 patients having undergone cerebral embolization, it was deduced that six of them have received a dose above 1 Gy. Detailed dose data from patients undergoing IR procedures will be collected in the future with the aim of developing a model to allow estimation of the dose prior to the procedure as well as to look at techniques of dose reduction. (author)

  15. Gamma dosimetry of high doses

    International Nuclear Information System (INIS)

    Martinez C, T.; Galvan G, A.; Canizal, G.

    1991-01-01

    The gamma dosimetry of high doses is problematic in almost all the classic dosemeters either based on the thermoluminescence, electric, chemical properties, etc., because they are saturated to very high dose and they are no longer useful. This work carries out an investigation in the interval of high doses. The solid system of heptahydrate ferrous sulfate, can be used as solid dosemeter of routine for high doses of radiation. The proposed method is simple, cheap and it doesn't require sophisticated spectrophotometers or spectrometers but expensive and not common in some laboratories

  16. Spiral CT and radiation dose

    International Nuclear Information System (INIS)

    Imhof, H.; Schibany, N.; Ba-Ssalamah, A.; Czerny, C.; Hojreh, A.; Kainberger, F.; Krestan, C.; Kudler, H.; Noebauer, I.; Nowotny, R.

    2003-01-01

    Recent studies in the USA and Europe state that computed tomography (CT) scans compromise only 3-5% of all radiological exams, but they contribute 35-45% of total radiation dose to the patient population. These studies lead to concern by several public authorities. Basis of CT-dose measurements is the computed tomography dose index (CTDI), which was established 1981. Nowadays there are several modifications of the CTDI values, which may lead to confusion. It is suggested to use the standardized CTDI-100 w. value together with the dose length product in all CT-examinations. These values should be printed on all CT-images and allows an evaluation of the individualized patient dose. Nowadays, radiologist's aim must be to work at the lowest maximal diagnostic acceptable signal to noise ratio. To decrease radiation dose radiologist should use low kV and mA, but high pitches. Newly developed CT-dose-reduction soft-wares and filters should be installed in all CT-machines. We should critically compare the average dose used for a specific examination with the reference dose used in this country and/or Europe. Greater differences should caution the radiologist. Finally, we as radiologists must check very carefully all indications and recommend alternative imaging methods. But we have also to teach our customers--patients and medical doctors who are non-radiologists--that a 'good' image is not that which show all possible information, but that which visualize 'only' the diagnostic necessary information

  17. Utilidad de winmedtra para conocer la prevalencia del tabaquismo en un hospital de referencia

    Directory of Open Access Journals (Sweden)

    A. Ranchal-Sánchez

    2015-06-01

    Full Text Available Introducción: La creación de lugares de trabajo sin humo sigue siendo la medida de mayor implantación frente al tabaquismo. WinMedtra es la aplicación informática corporativa del Servicio Andaluz de Salud para la Vigilancia de la Salud. Objetivo: Aprovechando dicha aplicación, planteamos mostrar su utilidad para calcular la prevalencia de tabaquismo en un Hospital de referencia. Material y método: Estudio observacional a partir de los exámenes de salud realizados en 2013 (n=1672. Se extrajeron los datos relativos al consumo de tabaco de WinMedtra realizándose una estadística descriptiva e inferencial (prueba "t" de Student, análisis de varianza simple y Ji-Cuadrado. Resultados: La aplicación informática nos ha permitido obtener datos del hábito tabáquico en la población laboral estudiada. La prevalencia de sujetos fumadores activos fue de un 22,8% (IC95%:20,79%-24,81% y el 19,8% eran ex fumadores, por lo que el 77,2% no fumaba en el periodo del estudio (IC95%: 75,19%-79,21%. El consumo acumulado fue mayor en el grupo de los hombres que en el de las mujeres (21,08 ± 16,31 versus 15,38±13,28 paquetes-año (t: 3,61, p<0,001. Se obtuvieron diferencias significativas (p<0,001 al comparar la edad media de los no fumadores con respecto a la de los fumadores, (48,33± 9,82 versus 50,55 ± 7,62 años y a la de exfumadores (48,33 ± 9,82 versus 50,65 ± 8,32 años. En relación a la categoría laboral, el mayor porcentaje de "No fumadores" pertenecía al personal residente en formación (87% seguido del grupo de jefaturas (75%; siendo los auxiliares administrativos (34,7% y el los supervisores (33,3% quienes presentaban un mayor porcentaje de consumo tabáquico (Ji-cuadrado=131,23, p<0,001. Conclusiones: La aplicación informática puede ser útil para tener un conocimiento epidemiológico más exacto de la magnitud de conductas adictivas como el tabaquismo en centros de trabajo, obteniéndose en nuestro estudio una prevalencia de

  18. Eficiência no uso da água na cana-de-açúcar sob diferentes lâminas de irrigação e níveis de zinco no litoral paraibano Water use efficiency in sugarcane crop under different depths of irrigation and zinc doses in coastal region of Paraíba, Brazil

    Directory of Open Access Journals (Sweden)

    Carlos H. A. Farias

    2008-09-01

    Full Text Available Esta pesquisa foi conduzida em área experimental da Fazenda Capim II, localizada no Município de Capim - PB, com o intuito de determinar a eficiência no uso da água (EUA pela cana-de-açúcar (Saccharum officinarum L., cultivar SP 79-1011. O delineamento experimental consistiu em blocos casualizados, com três repetições, em esquema fatorial 5 x 5. Os tratamentos referentes à lâmina de irrigação foram: sequeiro; 25; 50; 75 e 100% da ETc (1.026,57 mm com as respectivas precipitações efetivas de 780,06; 713,31; 487,54; 243,71 e 194,51 mm; os níveis de zinco estudados foram 0; 1; 2; 3 e 4 kg ha-1. O equipamento de irrigação utilizado foi do tipo pivô central, com turno de rega de nove dias. A eficiência no uso da água (EUA na produção de colmos e de açúcar aumenta à medida que se eleva a lâmina total de água aplicada à cultura. Para a região norte-paraibana dos tabuleiros costeiros, a EUA na produção de colmo e de açúcar, de forma maximizada, é 7,12 e 0,67 kg m-3, respectivamente.The study was conducted in an experimental area of the Capim II Farm, located in the municipality of Capim - PB, Brazil, with the objective of determining the efficiency in the use of the water (WUE for the sugarcane crop (Saccharum officinarum L., cultivar SP 79-1011. The experimental design consisted of randomized blocks, with three replications in a 5 x 5 factorial design. The irrigation treatments were: rainfed; 25; 50; 75 and 100% of the ETc (1,026.57 mm with the respective effective precipitations of 780.06; 713.31; 487.54; 243.71 and 194.51 mm. The levels of zinc studied were 0; 1; 2; 3 and 4 kg ha-1. The irrigation equipment used in the study was a central pivot with irrigation frequency of nine days. The water use efficiency (WUE of sugarcane crop in terms of cane production and of sugar increased with the depth of water applied. For the Coastal Table Lands of northern Paraiba, the maximized WUE for sugarcane and sugar production is

  19. Tres aproximaciones para estimación y distribución espacio-temporal del balance hídrico: el caso de la cuenca de Cuitzeo, Michoacán, México

    Directory of Open Access Journals (Sweden)

    Alfredo Amador García

    2012-02-01

    Full Text Available La distribución espacial de la energía y los flujos de ciclo hidrológico en forma de vapor (evapotranspiración, escurrimiento e infiltración en una región, son una función de las características climáticas (precipitación, temperatura y evaporación y del paisaje (relieve, suelo y cobertura de un área y constituyen el llamado ciclo hidrológico. El modelo general de evaluación de cada uno de los compartimentos y flujos es el balance hídrico. Los métodos desarrollados para calcular el balance hídrico de una región toman como base el enfoque de transferencia de masa o el de transferencia de energía. Este trabajo se planteó como objetivo calcular, comparar y evaluar tres aproximaciones en la estimación del balance hídrico regional espacialmente distribuido en cuencas sin datos de aforos. El modelamiento espacial de las variables hidrometeorológicas se efectuó en el sistema de información geográfica ArcView 3.2, y el modelamiento de los del escurrimiento se realizó con el sistema HEC versión 3.1.0. La primera aproximación está basada en el análisis de la información registrada en las estaciones meteorológicas disponibles, estimación puntual del balance hídrico mensual conforme al método de Thornthwaite y Mather y de polígonos de Thiessen; la segunda, en el cálculo y distribución de los parámetros para la aplicación del Método de Thornthwaite y Mather; finalmente la tercera aproximación se basó en el uso de la ecuación de FAO – Penman. Se escogió a la cuenca del lago de Cuitzeo como área de aplicación de los modelos. Destaca que mediante el resultado de la 3ª aproximación el volumen anual promedio de escurrimientos corresponde a 229.05 hm3. Dicho volumen es apenas 8.5 hm3 inferior al estimado como necesario para mantener 1 m de profundidad en la extensión del cuerpo de agua del lago de Cuitzeo. Esta diferencia representa en esa misma extensión una eventual fluctuación de 3 cm en el nivel medio del

  20. Low doses effects and gamma radiations low dose rates

    International Nuclear Information System (INIS)

    Averbeck, D.

    1999-01-01

    This expose wishes for bringing some definitions and base facts relative to the problematics of low doses effects and low dose rates effects. It shows some already used methods and some actual experimental approaches by focusing on the effects of ionizing radiations with a low linear energy transfer. (N.C.)

  1. Do dose area product meter measurements reflect radiation doses ...

    African Journals Online (AJOL)

    Enrique

    SA JOURNAL OF RADIOLOGY • August 2004. Abstract. This study determined the correlation between radiation doses absorbed by health care workers and dose area product meter (DAP) measurements at Universitas Hospital, Bloemfontein. The DAP is an instrument which accurately measures the radiation emitted from ...

  2. Do dose area product meter measurements reflect radiation doses ...

    African Journals Online (AJOL)

    This study determined the correlation between radiation doses absorbed by health care workers and dose area product meter (DAP) measurements at Universitas Hospital, Bloemfontein. The DAP is an instrument which accurately measures the radiation emitted from the source. The study included the interventional ...

  3. Composição química de tubérculos de batata para processamento, cultivados sob diferentes doses e fontes de potássio Chemical composition of potato tubers for processing, grown in different levels and sources of potassium

    Directory of Open Access Journals (Sweden)

    Diomar Augusto de Quadros

    2009-06-01

    Full Text Available A batata é considerada um dos poucos alimentos capazes de nutrir a crescente população mundial por ser fonte de energia e conter elevado teor de proteínas, vitaminas e minerais. Porém os teores desses compostos sofrem influência de diversos fatores como: cultivar utilizada, condições edafoclimáticas, safra, colheita e armazenamento. Assim, o presente trabalho teve como objetivo determinar a composição química de batatas (cvs. Atlantic, Asterix, Innovator e Shepody, cultivadas em quatro doses (0, 120, 360 e 1080 kg K2O.ha-1 e duas fontes de potássio (KCl e K2SO4. As amostras foram provenientes do município de Fazenda Rio Grande/PR, cultivadas na safra das águas. Foram realizadas as seguintes determinações: vitamina C, umidade, proteínas, lipídios, cinzas, carboidratos, energia, amido e potássio. A cv. Atlantic apresentou os maiores teores médios de cinzas (0,93% e potássio (528,80 mg.100 g-1; a cv. Asterix, a maior umidade (81,47%; a cv. Innovator, os maiores teores de proteínas (2,25%, lipídios (0,06%, carboidratos (17,72%, energia (80,40 kcal.100 g-1 e amido (16,45%; e a cv. Shepody obteve a maior quantidade de vitamina C (31,01 mg.100 g-1. Pode-se concluir que a composição química das batatas é dependente da cultivar e da adubação potássica (dose e fonte empregada.Potato is considered one of the few foods able to nourish the growing world population for being a source of energy and containing high levels of proteins, vitamins, and minerals. However, these compounds suffer influence of several factors such as the use of cultivars, soil and climate characteristics, crop, harvest, and storage. Hence, the present paper aims to determine the potato chemical composition (cvs. Atlantic, Asterix, Innovator and Shepody, grown under four different levels (0, 120, 360 and 1080 kg K2O.ha-1 and two different sources of potassium (KCl e K2SO4. Samples of crop water production were collected from a farm in the city of Fazenda

  4. Characterization of TLD-100 in powders for dosimetric quality control of {sup 192} Ir sources used in brachytherapy of high dose rate; Caracterizacion de TLD-100 en polvo para control de calidad dosimetrico de fuentes de Ir{sup 192} usadas en braquiterapia de alta tasa de dosis

    Energy Technology Data Exchange (ETDEWEB)

    Loaiza C, S.P

    2007-07-01

    The Secondary Standard Dosimetric at the National Institute of Nuclear Research (ININ) calibrated a lot of powdered TLD-100 (LiF:Mg,Ti) in terms of absorbed dose to water D{sub w} for the energy of: {sup 60}Co, {sup 137C}s, X rays of 250 and 50 kVp. Later on, it is carried out an interpolation of the calibration for the energy of the {sup 192}Ir. This calibration is part of a dosimetric quality control program, to solve the problems of traceability for the measurements carried out by the users of {sup 192}Ir sources employed in the treatments of High Dose Rate Brachytherapy (HDR) at the Mexican Republic. The calibrations of the radiation beams are made with the following protocols: IAEA TRS-398 for the {sup 60}Co for D{sub w}, using a secondary standard ionization chamber PTW N30013 calibrated in D{sub w} by the National Research Council (NRC, Canada). AAPM TG-43 for D{sub w} in terms of the strength kerma Sk, calibrating this last one quantity for the {sup 137}Cs radioactive source, with a well chamber HDR 1000 PLUS traceable to the University of Wisconsin (US). AAPM TG-61 for X ray of 250 and 50 kVp for D{sub w} start to Ka using field standard a Farmer chamber PTW 30001 traceable to K for the Central Laboratory of Electric Industries (CLEI, France). The calibration curves (CC) they built for the response of the powder TLD: R{sub TLD} vs D{sub w}: For the energy of {sup 60}Co, {sup 137}Cs, X rays of 250 and 50 kVp. Fitting them with the least square method weighed by means of a polynomial of second grade that corrects the supra linearity of the response. iii. Each one of the curves was validated with a test by lack of fitting and for the Anderson Darling normality test, using the software MINITAB in both cases. iv. The sensibility factor (F{sub s}) for each energy corresponds to the slope of the CC, v. The F{sub s} for the two {sup 192}Ir sources used are interpolated: one for a Micro Selectron source and the other one a Vari Source source. Finally, a couple of

  5. A dose error evaluation study for 4D dose calculations

    Science.gov (United States)

    Milz, Stefan; Wilkens, Jan J.; Ullrich, Wolfgang

    2014-10-01

    Previous studies have shown that respiration induced motion is not negligible for Stereotactic Body Radiation Therapy. The intrafractional breathing induced motion influences the delivered dose distribution on the underlying patient geometry such as the lung or the abdomen. If a static geometry is used, a planning process for these indications does not represent the entire dynamic process. The quality of a full 4D dose calculation approach depends on the dose coordinate transformation process between deformable geometries. This article provides an evaluation study that introduces an advanced method to verify the quality of numerical dose transformation generated by four different algorithms. The used transformation metric value is based on the deviation of the dose mass histogram (DMH) and the mean dose throughout dose transformation. The study compares the results of four algorithms. In general, two elementary approaches are used: dose mapping and energy transformation. Dose interpolation (DIM) and an advanced concept, so called divergent dose mapping model (dDMM), are used for dose mapping. The algorithms are compared to the basic energy transformation model (bETM) and the energy mass congruent mapping (EMCM). For evaluation 900 small sample regions of interest (ROI) are generated inside an exemplary lung geometry (4DCT). A homogeneous fluence distribution is assumed for dose calculation inside the ROIs. The dose transformations are performed with the four different algorithms. The study investigates the DMH-metric and the mean dose metric for different scenarios (voxel sizes: 8 mm, 4 mm, 2 mm, 1 mm 9 different breathing phases). dDMM achieves the best transformation accuracy in all measured test cases with 3-5% lower errors than the other models. The results of dDMM are reasonable and most efficient in this study, although the model is simple and easy to implement. The EMCM model also achieved suitable results, but the approach requires a more complex

  6. The patient dose survey and dose reduction in diagnostic radiology

    International Nuclear Information System (INIS)

    Dang Thanh Luong; Duong Van Vinh; Ha Ngoc Thach

    2000-01-01

    This paper presented the results of the patient dose survey in some hospitals in Hanoi from 1995 to 1997. The main investigated types of the X-ray examination were: Chest PA, LAT; Skull PA/AP, LAT; Lumbar spine AP, LAT; and Pelvis AP. The fluctuation of the entrance surface doses (ESD) was too large, even in the same type of X-ray examination and X-ray facility. It was found that the ratio of maximum and minimum ESD were ranged from 1.5 to 18. The mean values of ESD for chest and skull were higher than CEC recommended values, while the mean values of lumbar spine and pelvis were smaller than that of CEC recommended values. The result of dose intercomparison was also reported. Some methods of dose reduction were applied for improving the patient dose in X-ray departments such as a high kV technique, high sensitive screen-film combination. (author)

  7. HERRAMIENTAS GEOMÉTRICAS PARA EL DISEÑO BÁSICO DE COLUMNAS DE DESTILACIÓN CON MEZCLAS AZEOTRÓPICAS HETEROGÉNEAS TERNARIAS: I. CÁLCULO DEL REFLUJO MÍNIMO FERRAMENTAS GEOMÉTRICAS PARA O DESENHO BÁSICO DE COLUNAS DE DESTILACÃO COM MISTURAS AZEOTRÓPICAS HETEROGÊNEAS TERNARIAS: I. CÁLCULO DO REFLUXO MÍNIMO GEOMETRICAL TOOLS FOR THE BASIC DESIGN OF DISTILLATION COLUMNS WITH TERNARY HETEROGENEOUS AZEOTROPIC MIXTURES: I. MINIMUM REFLUX CALCULATION

    Directory of Open Access Journals (Sweden)

    César Augusto Sánchez

    2012-12-01

    Full Text Available En este trabajo se presentan herramientas numéricas útiles para calcular el reflujo mínimo en torres infinitas. Como eje de los argumentos se consideran dos elementos geométricos: los ramales de puntos pinch (RPP y la estructura determinada por la binodal y la línea de vapor. El interés principal consiste en la integración de estos elementos con las fronteras de destilación a reflujo total, con el fin de explorar el problema del diseño conceptual. Se demuestra la utilidad de estos elementos resolviendo el problema del reflujo mínimo (PRM para tres ejemplos que involucran las deshidrataciones de mezclas acuosas de ácido acético utilizando n-amilacetato y de etanol utilizando benceno. Se evidencia que la estructura de las líneas de destilación a reflujo mínimo para las separaciones agudas satisface las regularidades observadas en los sistemas homogéneos.Neste trabalho apresentam-se ferramentas numéricas úteis para calcular o refluxo mínimo em torres infinitas. Como eixo dos argumentos se consideram dois elementos geométricos: os ramais de pontos pinch (RPP e a estrutura determinada pela binodal e a linha de vapor. O interesse principal consiste na integração destes elementos com as fronteiras de destilação a refluxo total com o fim de explorar o problema do desenho conceitual. Demonstra-se a utilidade destes elementos resolvendo o problema do refluxo mínimo (PRM para três exemplos que envolvem as desidratações de misturas aquosas de ácido acético utilizando n-amilacetato e de etanol utilizando benzeno. Evidencia-se que a estrutura das linhas de destilação a refluxo mínimo para as separações agudas satisfaz as regularidades observadas nos sistemas homogêneos.Useful numerical tools to calculate the minimum reflux for infinite towers with heterogeneous azeotropic ternary mixtures are presented. For this, two geometrical elements are involved: the pinch point branches (PPB and the structure defined by the binodal

  8. Uso do 1-metilciclopropeno para retardar a maturação de tomate

    Directory of Open Access Journals (Sweden)

    Krammes Juliana Golin

    2003-01-01

    Full Text Available Tomates (Lycopersicon esculentum, cultivar 'Santa Clara' e o híbrido 'Carmen' (longa vida, tratados no estádio verde-maduro com 1-metilciclopropeno (1-MCP, apresentaram retardo nos picos de produção de etileno e CO2, redução nas taxas respiratórias, maior acidez titulável, maior retenção de firmeza e retardo no desenvolvimento de cor vermelha em relação a frutos não tratados, durante vida de prateleira a 23ºC. Os teores de sólidos solúveis totais não foram afetados pelo tratamento com 1-MCP. As doses de 1-MCP necessárias para retardar os picos de produção de etileno e CO2 e aumentar a acidez foram de 300 nl L-1 e 500 nl L-1, para tomates 'Santa Clara' e 'Carmen', respectivamente. Todavia, a retenção de firmeza e o retardo na evolução de cor vermelha da casca foram substanciais com a dose 150 nl L-1 para a cultivar 'Santa Clara', e com a dose de 250 nl L-1 para o híbrido 'Carmen'. Estes resultados mostram o grande potencial de emprego comercial do 1-MCP para retardar a maturação de tomates 'Santa Clara' e 'Carmen' em temperaturas ambientes.

  9. Planificación automatizada del arranque de generadores para la restauración de sistemas eléctricos de potencia ;Generator Start-Up automated planning for electric power system restoration

    Directory of Open Access Journals (Sweden)

    Leonel Francisco Aleaga Loaiza

    2015-06-01

    Full Text Available La elección de la secuencia de arranque de los generadores afecta directamente a la capacidad de generación disponible en el proceso de restauración del sistema de potencia. En este artículo se utiliza un método basado en la planificación automatizada para calcular la secuencia de arranque de las unidades de generación en el proceso de restauración de sistemas eléctricos de potencia. Se presenta una formulación basada en acciones donde se involucran varios factores complejos tales como: la naturaleza combinatoria, el conocimiento de expertos, varias restricciones y condiciones cambiantes en el tiempo que deben cumplirse y la optimización de varios recursos numéricos. Los resultados de prueba sobre el sistema IEEE39-barras muestran que el método es muy eficiente en obtener planes precisos y optimizados para restaurar el sistema de generación utilizando un algoritmo de planificación automatizada basado en la búsqueda heurística con capacidades de razonamiento en tiempo continuo.The choice of generator startup sequence affects directly the available generation capacity in the power system restoration process. In this paper an automated planning based method is used to calculate the startup sequence generating units in the electric power system restoration process. An action-based formulation is presented where several complex factors are involved such us: the combinatorial nature, expert knowledge, several restrictions and changing conditions over time that must be met and the optimization of several numerical resources. The test result son theIEEE39-bus system show that the method is veryefficientto obtain accurate and optimized plans to restore the generation system using an automated planning algorithm based on heuristic search with capabilities of reasoning in continuous time.

  10. Utilização de sensoriamento remoto em análises de albedo e temperatura de superfície em Londrina - PR: contribuições para estudos de ilha de calor urbana

    Directory of Open Access Journals (Sweden)

    Nancy Laura Rios Gamarra

    2014-12-01

    Full Text Available Este trabalho avaliou o albedo (αs e a temperatura de superfície continental (Tsup provenientes de sensoriamento remoto, e a temperatura do ar (Tar medida in situ no intuito de caracterizar a Ilha de Calor Urbana (ICU na cidade de Londrina (Paraná. Foram utilizados dados de αs e Tsup obtidos do sensor MODIS, e medições in situ de Tar realizadas entre junho e agosto de 2011 por sensores meteorológicos instalados em 13 locais na cidade. Os dados de αs e Tsup foram utilizados para calcular um índice de urbanização (IU na região e posteriormente comparado com Tar. A análise dos dados de αs e Tsup foi consistente com as medições in situ, evidenciando sua aplicabilidade na avaliação espaço-temporal de fenômenos acoplados continente-atmosfera, tais como a ICU. A mancha urbana da cidade de Londrina apresentou valores de IU compreendido entre 18 e 20, bem maiores que as áreas mais vegetadas (14 - 16. Nesse sentido, o IU demonstrou-se ser uma metodologia útil para representar a evolução espaço-temporal de áreas urbanas, o que pode propiciar uma avaliação detalhada do impacto da mudança de cobertura de solo no clima local e regional. Além disso, os resultados indicam que dados obtidos via satélite podem auxiliar grandemente na quantificação da ICU, quando dados in situ estiverem indisponíveis.

  11. Time and dose in carcinogenesis

    International Nuclear Information System (INIS)

    Mayneord, W.V.; Clarke, R.H.

    1978-05-01

    Previous work on the implications of different forms of dose response relationships is extended to include time as a variable, not only in time of irradiation but also in the time of appearance of effects following irradiation. The forms of relationships for time distribution of tumours revealed experimentally for both radiation and chemical carcinogens are first considered. It appears that much data may be correlated in terms of a log-normal distribution of tumour yield following the insult. Further, it is noted, that there is evidence that the median time of tumour appearance may be a function of total dose received or even of dose rate for protracted exposure. Using numerical values of these parameters derived from the biological literature speculative studies have been made of the effects on dose response relationships of using a time distribution of tumour yield, considering both uniform irradiation and point sources. In addition the effects of using dose rate rather than dose to define the log-normal distribution to tumour appearance have been investigated. It is assumed that biological response is directly proportional to dose but that effect is distributed in time. From this linear assumption the appearance of non-linear dose response relationships and apparent thresholds are continually seen. Finally, both the importance of attempting analyses of biological data in terms of stochastic concepts and the need for biological data to test our hypotheses is emphasised. (author)

  12. EPA's Benchmark Dose Modeling Software

    Science.gov (United States)

    The EPA developed the Benchmark Dose Software (BMDS) as a tool to help Agency risk assessors facilitate applying benchmark dose (BMD) method’s to EPA’s human health risk assessment (HHRA) documents. The application of BMD methods overcomes many well know limitations ...

  13. Microbeams, microdosimetry and specific dose

    International Nuclear Information System (INIS)

    Randers-Pehrson, H.

    2002-01-01

    Dose and its usefulness as a single parameter to describe the amount of radiation absorbed are well established for most situations. The conditions where the concept of dose starts to break down are well known, mostly from the study of microdosimetry. For low doses of high LET radiation it is noted that the process of taking the limiting value of the energy absorbed within a test volume divided by the mass within that volume yields either zero or a relatively large value. The problem is further exacerbated with microbeam irradiations where the uniformity of the energy deposition is experimentally manipulated on the spatial scale of cells being irradiated. Booz introduced a quantity to deal with these problems: the unfortunately named 'mean specific energy in affected volumes'. This quantity multiplied by the probability that a test volume has received an energy deposit is equal to dose (in situations where dose can be defined). I propose that Booz's quantity be renamed 'specific dose', that is the mean energy deposited divided by the mass within a specified volume. If we believe for instance that the nucleus of a cell is the critical volume for biological effects, we can refer to the nuclear specific dose. A microbeam experiment wherein 10 per cent of the cell nuclei were targeted with 10 alpha particles would be described as delivering a nuclear specific dose of 1.6 Gy to 10 per cent of the population. (author)

  14. Radiation absorbed doses in cephalography

    International Nuclear Information System (INIS)

    Eliasson, S.; Julin, P.; Richter, S.; Stenstroem, B.

    1984-01-01

    Radiation absorbed doses to different organs in the head and neck region in lateral (LAT) and postero-anterior (PA) cephalography were investigated. The doses were measured by thermoluminescence dosimeters (TLD) on a tissue equivalent phantom head. Lanthanide screens in speed group 4 were used at 90 and 85 k Vp. A near-focus aluminium dodger was used and the radiation beam was collimated strictly to the face. The maximum entrance dose from LAT was 0.25 mGy and 0.42 mGy from a PA exposure. The doses to the salivary glands ranged between 0.2 and 0.02 mGy at LAT and between 0.15 and 0.04 mGy at PA exposures. The average thyroid gland dose without any shielding was 0.11 mGy (LAT) and 0.06 mGy (PA). When a dodger was used the dose was reduced to 0.07 mGy (LAT). If the thyroid gland was sheilded off, the dose was further reduced to 0.01 mGy and if the thyroid region was collimated out of the primary radiation field the dose was reduced to only 0.005 mGy. (authors)

  15. Central index of dose information

    International Nuclear Information System (INIS)

    1991-01-01

    The Central Index of Dose Information (CIDI) is a national database of occupational exposure to radiation operated by the NRPB as agent for the Health and Safety Executive. It receives summarised information on the radiation doses to classified persons in Great Britain annually from Approved Dosimetry Services. This document is the first annual CIDI summary of the data, giving statistics for 1986. (UK)

  16. ¿Argumentar para definir o definir para argumentar?

    OpenAIRE

    Silva, Luz; Samper, Carmen

    2013-01-01

    Se presenta y se ilustra un marco de referencia de un estudio en curso para obtener el título de Maestría en Docencia de la Matemática de la Universidad Pedagógica Nacional (Colombia); estudio sobre la conexión entre las acciones de definir y argumentar, que puede contribuir a la práctica de profesores en ejercicio y en formación. La habilidad para construir una definición es un posible indicio de comprensión, mientras que saberla de memoria no garantiza la comprensión del concepto (Vinner, 1...

  17. Dose optimisation in computed radiography

    International Nuclear Information System (INIS)

    Schreiner-Karoussou, A.

    2005-01-01

    After the installation of computed radiography (CR) systems in three hospitals in Luxembourg a patient dose survey was carried out for three radiographic examinations, thorax, pelvis and lumbar spine. It was found that the patient doses had changed in comparison with the patient doses measured for conventional radiography in the same three hospitals. A close collaboration between the manufacturers of the X-ray installations, the CR imaging systems and the medical physicists led to the discovery that the speed class with which each radiographic examination was to be performed, had been ignored, during installation of the digital imaging systems. A number of procedures were carried out in order to calibrate and program the X-ray installations in conjunction with the CR systems. Following this optimisation procedure, a new patient dose survey was carried out for the three radiographic examinations. It was found that patient doses for the three hospitals were reduced. (authors)

  18. Evolution of radon dose evaluation

    Directory of Open Access Journals (Sweden)

    Fujimoto Kenzo

    2004-01-01

    Full Text Available The historical change of radon dose evaluation is reviewed based on the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR reports. Since 1955, radon has been recognized as one of the important sources of exposure of the general public. However, it was not really understood that radon is the largest dose contributor until 1977 when a new concept of effective dose equivalent was introduced by International Commission on Radiological Protection. In 1982, the dose concept was also adapted by UNSCEAR and evaluated per caput dose from natural radiation. Many researches have been carried out since then. However, lots of questions have remained open in radon problems, such as the radiation weighting factor of 20 for alpha rays and the large discrepancy of risk estimation among dosimetric and epidemiological approaches.

  19. Bone and marrow dose modeling

    International Nuclear Information System (INIS)

    Stabin, Michael G.

    2004-01-01

    Nuclear medicine therapy is being used increasingly in the treatment of cancer (thyroid, leukemia/lymphoma with RIT, primary and secondary bone malignancies, and neuroblastomas). In all cases it is marrow toxicity that limits the amount of treatment that can be administered safely. Marrow dose calculations are more difficult than for many major organs because of the intricate association of bone and soft tissue elements. In RIT, there appears to be no consensus on how to calculate that dose accurately, or of individual patients ability to tolerate planned therapy. Available dose models are designed after an idealized average, healthy individual. Patient-specific methods are applied in evaluation of biokinetic data, and need to be developed for treatment of the physical data (dose conversion factors) as well: age, prior patient therapy, disease status. Contributors to marrow dose: electrons and photons

  20. Radiation dose during angiographic procedures

    International Nuclear Information System (INIS)

    Lavoie, Ch.; Rasuli, P.

    2001-01-01

    The use of angiographic procedures is becoming more prevalent as new techniques and equipment are developed. There have been concerns in the scientific community about the level of radiation doses received by patients, and indirectly by staff, during some of these radiological procedures. The purpose of this study was to assess the level of radiation dose from angiographic procedures to patient at the Ottawa Hospital, General Campus. Radiation dose measurements, using Thermo-Luminescent Dosimeters (TLDs), were performed on more than 100 patients on various procedures. The results show that while the patient dose from the great majority of angiographic procedures is less than 2 Gy, a significant number of procedures, especially interventional procedures may have doses greater than 2 Gy and may lead to deterministic effects. (author)

  1. Labour cost of radiation dose

    International Nuclear Information System (INIS)

    Cook, A.; Lockett, L.E.

    1978-01-01

    In order to optimise capital expenditure on measures to protect workers against radiation it would be useful to have a means to measure radiation dose in money terms. Because labour has to be employed to perform radiation work there must be some relationship between the wages paid and the doses received. Where the next increment of radiation dose requires additional labour to be recruited the cost will at least equal the cost of the extra labour employed. This paper examines some of the factors which affect the variability of the labour cost of radiation dose and notes that for 'in-plant' exposures the current cost per rem appears to be significantly higher than values quoted in ICRP Publication 22. An example is given showing how this concept may be used to determine the capital it is worth spending on installed plant to prevent regular increments of radiation dose to workers. (author)

  2. Patient dose measurement and dose reduction in chest radiography

    Directory of Open Access Journals (Sweden)

    Milatović Aleksandra A.

    2014-01-01

    Full Text Available Investigations presented in this paper represent the first estimation of patient doses in chest radiography in Montenegro. In the initial stage of our study, we measured the entrance surface air kerma and kerma area product for chest radiography in five major health institutions in the country. A total of 214 patients were observed. We reported the mean value, minimum and third quartile values, as well as maximum values of surface air kerma and kerma area product of patient doses. In the second stage, the possibilities for dose reduction were investigated. Mean kerma area product values were 0.8 ± 0.5 Gycm2 for the posterior-anterior projection and 1.6 ± 0.9 Gycm2 for the lateral projection. The max/min ratio for the entrance surface air kerma was found to be 53 for the posterior-anterior projection and 88 for the lateral projection. Comparing the results obtained in Montenegro with results from other countries, we concluded that patient doses in our medical centres are significantly higher. Changes in exposure parameters and increased filtration contributed to a dose reduction of up to 36% for posterior-anterior chest examinations. The variability of the estimated dose values points to a significant space for dose reduction throughout the process of radiological practice optimisation.

  3. Establishment Of Dose Correlation During Dose Mapping On Medical Devices

    International Nuclear Information System (INIS)

    Ruzalina Baharin; Hasan Sham; Ahsanulkhaliqin Abdul Wahab

    2014-01-01

    This paper explains the work done during product dose mapping in order to get the correlation between doses at MINTec-Sinagama plant. Product used was medical devices in aluminium tubes packaged in cardboard kegs packaging with average weight of 12 kg per carton. 12 cartons were loaded in every one tote to give 0.2 g/ cm 3 of density. Ceric cerous dosimeters were placed at specific locations as indicated in SP14: Product Dose Mapping, QMS of MINTec-Sinagama around three planes. Three processes were made at different days as a three replicates to show the reproducibility of measurements. (author)

  4. Dosimetric systems of high dose, dose rate and dose uniformity in food and medical products

    International Nuclear Information System (INIS)

    Vargas, J.; Vivanco, M.; Castro, E.

    2014-08-01

    In the Instituto Peruano de Energia Nuclear (IPEN) we use the chemical dosimetry Astm-E-1026 Fricke as a standard dosimetric system of reference and different routine dosimetric systems of high doses, according to the applied doses to obtain the desired effects in the treated products and the doses range determined for each type of dosimeter. Fricke dosimetry is a chemical dosimeter in aqueous solution indicating the absorbed dose by means an increase in absorbance at a specific wavelength. A calibrated spectrophotometer with controlled temperature is used to measure absorbance. The adsorbed dose range should cover from 20 to 400 Gy, the Fricke solution is extremely sensitive to organic impurities, to traces of metal ions, in preparing chemical products of reactive grade must be used and the water purity is very important. Using the referential standard dosimetric system Fricke, was determined to March 5, 2013, using the referential standard dosimetric system Astm-1026 Fricke, were irradiated in triplicate Fricke dosimeters, to 5 irradiation times (20; 30; 40; 50 and 60 seconds) and by linear regression, the dose rate of 5.400648 kGy /h was determined in the central point of the irradiation chamber (irradiator Gamma cell 220 Excel), applying the decay formula, was compared with the obtained results by manufacturers by means the same dosimetric system in the year of its manufacture, being this to the date 5.44691 kGy /h, with an error rate of 0.85. After considering that the dosimetric solution responds to the results, we proceeded to the irradiation of a sample of 200 g of cereal instant food, 2 dosimeters were placed at the lateral ends of the central position to maximum dose and 2 dosimeters in upper and lower ends as minimum dose, they were applied same irradiation times; for statistical analysis, the maximum dose rate was 6.1006 kGy /h and the minimum dose rate of 5.2185 kGy /h; with a dose uniformity of 1.16. In medical material of micro pulverized bone for

  5. Taller para desarrollar la creatividad

    OpenAIRE

    MARTÍNEZ GUEROLA, BEATRIZ

    2015-01-01

    [ES] Partimos de la base de que la creatividad es una capacidad realmente valiosa, no solo para el ámbito artístico, si no para cualquier aspecto de la vida. Este proyecto está enfocado a un taller diseñado para que a partir de técnicas de expresión gráfico-plásticas podamos estimular y desarrollar la creatividad, principalmente en niños de tercer ciclo de primaria. Con este proyecto relacionamos el arte y la creatividad que se asocia a esté con la educación. Martínez Guerola, B. (2015). T...

  6. External beam abdominal radiotherapy in patients with seminoma stage I: field type, testicular dose, and spermatogenesis

    International Nuclear Information System (INIS)

    Jacobsen, Kari Dolven; Olsen, Dag Rune; Fossaa, Kristian; Fossaa, Sophie Dorothea

    1997-01-01

    Purpose: To establish a predictive model for the estimation of the gonadal dose during adjuvant para-aortic (PA) or dog leg (DL: PA plus ipsilateral iliac) field radiotherapy in patients with testicular seminoma. Methods and Materials: The surface gonadal dose was measured in patients with seminoma Stage I receiving PA or DL radiotherapy. Sperm cell analysis was performed before and 1 year after irradiation. PA and DL radiotherapy were simulated in the Alderson phantom while we measured the dose to the surface and middle of an artificial testicle, varying its position within realistic anatomical constraints. The symphysis-to-testicle distance (STD), field length, and thickness of the patient were experimental variables. The developed mathematical model was validated in subsequent patients. Results: The mean gonadal dose in patients was 0.09 and 0.32 Gy after PA and DL irradiation, respectively (p < 0.001). DL radiotherapy, but not PA irradiation led to significant reduction of the sperm count 1 year after irradiation. The gonadal dose-reducing effect of PA irradiation was confirmed in the Alderson phantom. A significant correlation was found between the STD and the gonadal dose during DL irradiation. A mathematical model was established for calculation of the gonadal dose and confirmed by measurements in patients. Conclusions: During radiotherapy of seminoma, the gonadal dose decreases with increasing STD. It is possible to predict the individual gonadal dose based on delivered midplane dose and STD

  7. Standardization of high-dose measurement of electron and gamma ray absorbed doses and dose rates

    International Nuclear Information System (INIS)

    McLaughlin, W.L.

    1985-01-01

    Intense electron beams and gamma radiation fields are used for sterilizing medical devices, treating municipal wastes, processing industrial goods, controlling parasites and pathogens, and extending the shelf-life of foods. Quality control of such radiation processes depends largely on maintaining measurement quality assurance through sound dosimetry procedures in the research leading to each process, in the commissioning of that process, and in the routine dose monitoring practices. This affords documentation as to whether satisfactory dose uniformity is maintained throughout the product and throughout the process. Therefore, dosimetry at high doses and dose rates must in many radiation processes be standardized carefully, so that 'dosimetry release' of a product is verified. This standardization is initiated through preliminary dosimetry intercomparison studies such as those sponsored recently by the IAEA. This is followed by establishing periodic exercises in traceability to national or international standards of absorbed dose and dose rate. Traceability is achieved by careful selection of dosimetry methods and proven reference dosimeters capable of giving sufficiently accurate and precise 'transfer' dose assessments: (1) they must be calibrated or have well-established radiation-yield indices; (2) their radiation response characteristics must be reproducible and cover the dose range of interest; (3) they must withstand the rigours of back-and-forth mailing between a central standardizing laboratory and radiation processing facilities, without excessive errors arising due to instabilities, dosimeter batch non-uniformities, and environmental and handling stresses. (author)

  8. Exhibidor de cinturones para Montagne

    OpenAIRE

    Galletti, Julia

    2017-01-01

    En el exhibidor de cinturones diseñado para la marca de ropa deportiva Montagne se produjo un trabajo estético-formal en relación a la simbología característica de la marca. Su principal característica es ser un exhibidor 360°, es decir que desde cualquier punto de vista se puede obtener un buen panorama del producto expuesto. Está confeccionado en materiales livianos para facilitar su movilidad dentro del local estipulado (exhibición en vidriera o mostrador). Asimismo, es totalmente desarmab...

  9. Colombia competente para la paz

    Directory of Open Access Journals (Sweden)

    Norma Sofía Vanegas Torres

    2013-07-01

    Full Text Available La paz y la convivencia en Colombia demandan el desarrollo de un enfoque humanístico, una competencia particular que como las restantes competencias implican un saber y un saber hacer dentro de un contexto, pero que en este caso se relacionan más concretamente con el saber vivir. Este artículo analiza el desarrollo de una posible de competencia para la paz y analiza la importancia de la academia como medio para su desarrollo e instrumentalización. Se analizan al mismo tiempo las connotaciones de esta competencia en el marco de la sociedad posmoderna contemporánea.

  10. Evaluación de los métodos directo, precipitado y Friedewald para la cuantificación de colesterol LDL y HDL en pollos de engorde

    Directory of Open Access Journals (Sweden)

    José Henry Osorio

    2012-12-01

    Full Text Available El objetivo fue evaluar los métodos directo y precipitado para el colesterol de las lipoproteínas de alta densidad y los métodos directo, precipitado y Friedewald para el colesterol de las lipoproteínas de baja densidad en pollos de engorde. Se obtuvo suero de 30 pollos de engorde de 36 días de edad, en ayunas, de la línea Cobb 500, se determinaron los niveles de triglicéridos y colesterol total usando un kit enzimático-colorimétrico. El colesterol, tanto de las lipoproteínas de alta densidad como de las de baja densidad, se midió por el método de precipitación y el método directo, y la estimación del colesterol de la lipoproteína de baja densidad se determinó usando la fórmula de Friedewald. Las medias ± desviación estándar para los niveles de colesterol de las lipoproteínas de alta densidad, por los métodos directo y precipitado, en mg/dl, fueron de: 92,8 ± 16,7; 92,2 ± 16,3, respectivamente. El valor P del test F es mayor a 0,05, por lo cual no hay diferencia estadísticamente significativa, con un índice de confianza de 95 % entre métodos, y para los niveles de colesterol de la lipoproteínas de baja densidad por los métodos directo, precipitado y Friedewald, en mg/dl, fueron: 51,8 ± 9,4; 21,9 ± 12,6 y 26,1 ± 12,9, respectivamente. El valor P del test F es inferior a 0,05 evidenciando diferencia estadísticamente significativa, con un índice de confianza de 95 % entre métodos. Se concluye que en los pollos de engorde se puede cuantificar el colesterol de la lipoproteína de alta densidad con los dos métodos evaluados (directo y precipitado, sin embargo, para calcular el colesterol de la lipoproteína de baja densidad solo se recomienda utilizar el método directo ya que los métodos de precipitado y de Friedewald dieron resultados mucho menores en dicha especie.

  11. Microcomputer based sliding regime discrete control for synchronous AC motors Control discreto por microordenador basado en regímenes deslizantes para motores de corriente alterna síncronos

    Directory of Open Access Journals (Sweden)

    Eduardo Palomar–Lever

    2007-12-01

    Full Text Available The basic ideas to design discrete algorithms used to calculate unmeasured mechanical or electrical variables, in order to control electrical motors in mechanical systems are presented. The main point of the paper is to simplify the algorithms by using a linear discrete time model without any variable limitations and to reduce the computing capacity requirements of the controller. Limited references, based on the discrete sliding mode for the exception of the influences of variable limitations, are proposed and designed. The main advantage of the controller presented in this paper is that a large control error does not bestow any problems. In such a case, the system always works in an area without the limitations. Original observation algorithms of both position and rotational velocity for exterior permanent magnet synchronous motors are designed. A computer simulation was performed and the results are presented, showing high dynamic accuracy.Se presentan las ideas básicas para diseñar algoritmos discretos para calcular las variables mecánicas o eléctricas, no medidas sino estimadas, para controlar motores eléctricos en sistemas mecánicos. El objetivo principal de este artículo es simplificar los algoritmos usando un modelo de tiempo discreto lineal sin ninguna limitación en las variables y reducir los requisitos de capacidad informática del controlador. Las referencias limitadas, basadas en el modo deslizante discreto para la excepción de las influencias de limitaciones de las variables, se proponen y diseñan. La ventaja principal del controlador presentada en este artículo es que un error de control grande no causa ningún problema. En dicho caso, el sistema trabaja siempre en un área sin limitaciones. Se diseñan los algoritmos de la observación originales de la posición y de la velocidad rotatoria para el imán permanente exterior de motores síncronos. Se llevó a cabo una simulación en computadora y se presentan los

  12. Radiation dose estimates for radiopharmaceuticals

    International Nuclear Information System (INIS)

    Stabin, M.G.; Stubbs, J.B.; Toohey, R.E.

    1996-04-01

    Tables of radiation dose estimates based on the Cristy-Eckerman adult male phantom are provided for a number of radiopharmaceuticals commonly used in nuclear medicine. Radiation dose estimates are listed for all major source organs, and several other organs of interest. The dose estimates were calculated using the MIRD Technique as implemented in the MIRDOSE3 computer code, developed by the Oak Ridge Institute for Science and Education, Radiation Internal Dose Information Center. In this code, residence times for source organs are used with decay data from the MIRD Radionuclide Data and Decay Schemes to produce estimates of radiation dose to organs of standardized phantoms representing individuals of different ages. The adult male phantom of the Cristy-Eckerman phantom series is different from the MIRD 5, or Reference Man phantom in several aspects, the most important of which is the difference in the masses and absorbed fractions for the active (red) marrow. The absorbed fractions for flow energy photons striking the marrow are also different. Other minor differences exist, but are not likely to significantly affect dose estimates calculated with the two phantoms. Assumptions which support each of the dose estimates appears at the bottom of the table of estimates for a given radiopharmaceutical. In most cases, the model kinetics or organ residence times are explicitly given. The results presented here can easily be extended to include other radiopharmaceuticals or phantoms

  13. Effects of small radiation doses

    International Nuclear Information System (INIS)

    Fuchs, G.

    1986-01-01

    The term 'small radiation dosis' means doses of about (1 rem), fractions of one rem as well as doses of a few rem. Doses like these are encountered in various practical fields, e.g. in X-ray diagnosis, in the environment and in radiation protection rules. The knowledge about small doses is derived from the same two forces, on which the radiobiology of human beings nearly is based: interpretation of the Hiroshima and Nagasaki data, as well as the experience from radiotherapy. Careful interpretation of Hiroshima dates do not provide any evidence that small doses can induce cancer, fetal malformations or genetic damage. Yet in radiotherapy of various diseases, e.g. inflammations, doses of about 1 Gy (100 rad) do no harm to the patients. According to a widespread hypothesis even very small doses may induce some types of radiation damage ('no threshold'). Nevertheless an alternative view is justified. At present no decision can be made between these two alternatives, but the usefullness of radiology is definitely better established than any damage calculated by theories or extrapolations. Based on experience any exaggerated fear of radiations can be met. (author)

  14. Patient dose in neonatal units

    International Nuclear Information System (INIS)

    Smans, K.; Struelens, L.; Smet, M.; Bosmans, H.; Vanhavere, F.

    2008-01-01

    Lung disease represents one of the most life-threatening conditions in prematurely born children. In the evaluation of the neonatal chest, the primary and most important diagnostic study is therefore the chest radiograph. Since prematurely born children are very sensitive to radiation, those radiographs may lead to a significant radiation detriment. Hence, knowledge of the patient dose is necessary to justify the exposures. A study to assess the patient doses was started at the neonatal intensive care unit (NICU) of the Univ. Hospital in Leuven. Between September 2004 and September 2005, prematurely born babies underwent on average 10 X-ray examinations in the NICU. In this sample, the maximum was 78 X-ray examinations. For chest radiographs, the median entrance skin dose was 34 μGy and the median dose area product was 7.1 mGy.cm 2 . By means of conversion coefficients, the measured values were converted to organ doses. Organ doses were calculated for three different weight classes: extremely low birth weight infants ( 2500 g). The doses to the lungs for a single chest radiograph for infants with extremely low birth weights, low birth weights and normal birth weights were 24, 25 and 32 μGy, respectively. (authors)

  15. CT dose reduction in children

    International Nuclear Information System (INIS)

    Vock, Peter

    2005-01-01

    World wide, the number of CT studies in children and the radiation exposure by CT increases. The same energy dose has a greater biological impact in children than in adults, and scan parameters have to be adapted to the smaller diameter of the juvenile body. Based on seven rules, a practical approach to paediatric CT is shown: Justification and patient preparation are important steps before scanning, and they differ from the preparation of adult patients. The subsequent choice of scan parameters aims at obtaining the minimal signal-to-noise ratio and volume coverage needed in a specific medical situation; exposure can be divided in two aspects: the CT dose index determining energy deposition per rotation and the dose-length product (DLP) determining the volume dose. DLP closely parallels the effective dose, the best parameter of the biological impact. Modern scanners offer dose modulation to locally minimise exposure while maintaining image quality. Beyond the selection of the physical parameters, the dose can be kept low by scanning the minimal length of the body and by avoiding any non-qualified repeated scanning of parts of the body. Following these rules, paediatric CT examinations of good quality can be obtained at a reasonable cost of radiation exposure. (orig.)

  16. Plutonium dose-effect relationship

    International Nuclear Information System (INIS)

    Matsuoka, Osamu

    1976-01-01

    Dose in internal exposure to Pu was investigated, and dose-effect relationship was discussed. Dose-effect relationship in internal exposure was investigated by means of two methods, which were relationship between dose and its effect (relationship between μ Ci/Kg and its effect), and exposure dose and its effects (rad-effect), and merits and demerits of two methods were mentioned. Problems in a indication method such as mean dose were discussed with respect to the dose in skeleton, the liver and the lung. Pu-induced osteosarcoma in mice rats, and beagles was described, and differences in its induction between animals were discussed. Pulmonary neoplasma induced by 239 PuO 2 inhalation in beagles was reported, and description was made as to differences in induction of lung cancer between animals when Pu was inhaled and was taken into the lung. A theoretical and experimental study of a extrapolation of the results of the animal experiment using Pu to human cases is necessary. (Serizawa, K.)

  17. Dose concentration and dose verification for radiotherapy of cancer

    International Nuclear Information System (INIS)

    Maruyama, Koichi

    2005-01-01

    The number of cancer treatments using radiation therapy is increasing. The background of this increase is the accumulated fact that the number of successful cases is comparative to or even better than surgery for some types of cancer due to the improvement in irradiation technology and radiation planning technology. This review describes the principles and technology of radiation therapy, its characteristics, particle therapy that improves the dose concentration, its historical background, the importance of dose concentration, present situation and future possibilities. There are serious problems that hinder the superior dose concentration of particle therapy. Recent programs and our efforts to solve these problems are described. A new concept is required to satisfy the notion of evidence based medicine, i.e., one has to develop a method of dose verification, which is not yet available. This review is for researchers, medical doctors and radiation technologists who are developing this field. (author)

  18. Pharmacokinetically guided dosing of (high-dose) chemotherapeutic agents

    NARCIS (Netherlands)

    Attema-de Jonge, M.E. (Milly Ellen)

    2004-01-01

    Due to variation in drug distribution, metabolism and elimination processes between patients, systemic exposure to chemotherapeutic agents may be highly variable from patient to patient after administration of similar doses. This pharmacokinetic variability may explain in part the large variability

  19. Superficial dose evaluation of four dose calculation algorithms

    Science.gov (United States)

    Cao, Ying; Yang, Xiaoyu; Yang, Zhen; Qiu, Xiaoping; Lv, Zhiping; Lei, Mingjun; Liu, Gui; Zhang, Zijian; Hu, Yongmei

    2017-08-01

    Accurate superficial dose calculation is of major importance because of the skin toxicity in radiotherapy, especially within the initial 2 mm depth being considered more clinically relevant. The aim of this study is to evaluate superficial dose calculation accuracy of four commonly used algorithms in commercially available treatment planning systems (TPS) by Monte Carlo (MC) simulation and film measurements. The superficial dose in a simple geometrical phantom with size of 30 cm×30 cm×30 cm was calculated by PBC (Pencil Beam Convolution), AAA (Analytical Anisotropic Algorithm), AXB (Acuros XB) in Eclipse system and CCC (Collapsed Cone Convolution) in Raystation system under the conditions of source to surface distance (SSD) of 100 cm and field size (FS) of 10×10 cm2. EGSnrc (BEAMnrc/DOSXYZnrc) program was performed to simulate the central axis dose distribution of Varian Trilogy accelerator, combined with measurements of superficial dose distribution by an extrapolation method of multilayer radiochromic films, to estimate the dose calculation accuracy of four algorithms in the superficial region which was recommended in detail by the ICRU (International Commission on Radiation Units and Measurement) and the ICRP (International Commission on Radiological Protection). In superficial region, good agreement was achieved between MC simulation and film extrapolation method, with the mean differences less than 1%, 2% and 5% for 0°, 30° and 60°, respectively. The relative skin dose errors were 0.84%, 1.88% and 3.90%; the mean dose discrepancies (0°, 30° and 60°) between each of four algorithms and MC simulation were (2.41±1.55%, 3.11±2.40%, and 1.53±1.05%), (3.09±3.00%, 3.10±3.01%, and 3.77±3.59%), (3.16±1.50%, 8.70±2.84%, and 18.20±4.10%) and (14.45±4.66%, 10.74±4.54%, and 3.34±3.26%) for AXB, CCC, AAA and PBC respectively. Monte Carlo simulation verified the feasibility of the superficial dose measurements by multilayer Gafchromic films. And the rank

  20. Effective doses in paediatric radiology

    International Nuclear Information System (INIS)

    Iacob, Olga; Diaconescu, Cornelia; Roca, Antoaneta

    2001-01-01

    Because of their longer life expectancy, the risk of late manifestations of detrimental radiation effects is greater in children than in adults and, consequently, paediatric radiology gives ground for more concern regarding radiation protection than radiology of adults. The purpose of our study is to assess in terms of effective doses the magnitude of paediatric patient exposure during conventional X-ray examinations, selected for their high frequency or their relatively high doses to the patient. Effective doses have been derived from measurements of dose-area product (DAP) carried out on over 900 patients undergoing X-ray examinations, in five paediatric units. The conversion coefficients for estimating effective doses are those calculated by the NRPB using Monte-Carlo technique on a series of 5 mathematical phantoms representing 0, 1, 5, 10 and 15 year old children. The annual frequency of X-ray examinations necessary for collective dose calculation are those reported in our last national study on medical exposure, conducted in 1995. The annual effective doses from all medical examinations for the average paediatric patient are as follows: 1.05 mSv for 0 year old, 0.98 mSv for 1 year old, 0.53 mSv for 5 year old, 0.65 mSv for 10 year old and 0.70 mSv for 15 year old. The resulting annual collective effective dose was evaluated at 625 man Sv with the largest contribution of pelvis and hip examinations (34%). The annual collective effective associated with paediatric radiology in Romania represent 5% of the annual value resulting from all diagnostic radiology. Examination of the chest is by far the most frequent procedure for children, accounting for about 60 per cent of all annually performed X-ray conventional examinations. Knowledge of real level of patient dose is an essential component of quality assurance programs in paediatric radiology. (authors)

  1. Late effects of low doses and dose rates

    International Nuclear Information System (INIS)

    Paretzke, H.G.

    1980-01-01

    This paper outlines the spectrum of problems and approaches used in work on the derivation of quantitative prognoses of late effects in man of low doses and dose rates. The origins of principal problems encountered in radiation risks assessments, definitions and explanations of useful quantities, methods of deriving risk factors from biological and epidemiological data, and concepts of risk evaluation and problems of acceptance are individually discussed

  2. Effects of low doses; Effet des faibles doses

    Energy Technology Data Exchange (ETDEWEB)

    Le Guen, B. [Electricite de France (EDF-LAM-SCAST), 93 - Saint-Denis (France)

    2001-07-01

    Actually, even though it is comfortable for the risk management, the hypothesis of the dose-effect relationship linearity is not confirmed for any model. In particular, in the area of low dose rate delivered by low let emitters. this hypothesis is debated at the light of recent observations, notably these ones relative to the mechanisms leading to genetic instability and induction eventuality of DNA repair. The problem of strong let emitters is still to solve. (N.C.)

  3. Savannah River Site dose control

    International Nuclear Information System (INIS)

    Smith, L.S.

    1992-01-01

    Health physicists from the Brookhaven National Laboratory (BNL) visited the Savannah River Site (SRS) as one of 12 facilities operated by the Department of Energy (DOE) contractors with annual collective dose equivalents greater than 100 person-rem (100 person-cSv). Their charter was to review, evaluate and summarize as low as reasonably achievable (ALARA) techniques, methods and practices as implemented. This presentation gives an overview of the two selected ALARA practices implemented at the SRS: Administrative Exposure Limits and Goal Setting. These dose control methods are used to assure that individual and collective occupational doses are ALARA and within regulatory limits

  4. Are low radiation doses Dangerous?

    International Nuclear Information System (INIS)

    Garcia Lima, O.; Cornejo, N.

    1996-01-01

    In the last few years the answers to this questions has been affirmative as well as negative from a radiation protection point of view low doses of ionizing radiation potentially constitute an agent causing stochasting effects. A lineal relation without threshold is assumed between dose and probability of occurrence of these effects . Arguments against the danger of probability of occurrence of these effects. Arguments again the danger of low dose radiation are reflected in concepts such as Hormesis and adaptive response, which are phenomena that being studied at present

  5. What is correct: equivalent dose or dose equivalent

    International Nuclear Information System (INIS)

    Franic, Z.

    1994-01-01

    In Croatian language some physical quantities in radiation protection dosimetry have not precise names. Consequently, in practice either terms in English or mathematical formulas are used. The situation is even worse since the Croatian language only a limited number of textbooks, reference books and other papers are available. This paper compares the concept of ''dose equivalent'' as outlined in International Commission on Radiological Protection (ICRP) recommendations No. 26 and newest, conceptually different concept of ''equivalent dose'' which is introduced in ICRP 60. It was found out that Croatian terminology is both not uniform and unprecise. For the term ''dose equivalent'' was, under influence of Russian and Serbian languages, often used as term ''equivalent dose'' even from the point of view of ICRP 26 recommendations, which was not justified. Unfortunately, even now, in Croatia the legal unit still ''dose equivalent'' defined as in ICRP 26, but the term used for it is ''equivalent dose''. Therefore, in Croatian legislation a modified set of quantities introduced in ICRP 60, should be incorporated as soon as possible

  6. Health effect of low dose/low dose rate radiation

    International Nuclear Information System (INIS)

    Kodama, Seiji

    2012-01-01

    The clarified and non-clarified scientific knowledge is discussed to consider the cause of confusion of explanation of the title subject. The low dose is defined roughly lower than 200 mGy and low dose rate, 0.05 mGy/min. The health effect is evaluated from 2 aspects of clinical symptom/radiation hazard protection. In the clinical aspect, the effect is classified in physical (early and late) and genetic ones, and is classified in stochastic (no threshold value, TV) and deterministic (with TV) ones from the radioprotection aspect. Although the absence of TV in the carcinogenic and genetic effects has not been proved, ICRP employs the stochastic standpoint from the safety aspect for radioprotection. The lowest human TV known now is 100 mGy, meaning that human deterministic effect would not be generated below this dose. Genetic deterministic effect can be observable only in animal experiments. These facts suggest that the practical risk of exposure to <100 mGy in human is the carcinogenesis. The relationship between carcinogenic risk in A-bomb survivors and their exposed dose are found fitted to the linear no TV model, but the epidemiologic data, because of restriction of subject number analyzed, do not always mean that the model is applicable even below the dose <100 mGy. This would be one of confusing causes in explanation: no carcinogenic risk at <100 mGy or risk linear to dose even at <100 mGy, neither of which is scientifically conclusive at present. Also mentioned is the scarce risk of cancer in residents living in the high background radiation regions in the world in comparison with that in the A-bomb survivors exposed to the chronic or acute low dose/dose rate. Molecular events are explained for the low-dose radiation-induced DNA damage and its repair, gene mutation and chromosome aberration, hypothesis of carcinogenesis by mutation, and non-targeting effect of radiation (bystander effect and gene instability). Further researches to elucidate the low dose

  7. Dose determination in computed tomography

    International Nuclear Information System (INIS)

    Descamps, C.; Garrigo, E.; Venencia, D.; Gonzalez, M.; Germanier, A.

    2011-10-01

    In the last years the methodologies to determine the dose in computed tomography have been revised. In this work was realized a dosimetric study about the exploration protocols used for simulation of radiotherapy treatments. The methodology described in the Report No. 111 of the American Association of Medical Physiques on a computed tomograph of two cuts was applied. A cylindrical phantom of water was used with dimensions: 30 cm of diameter and 50 cm of longitude that simulates the absorption and dispersion conditions of a mature body of size average. The doses were determined with ionization chamber and thermoluminescent dosimetry. The results indicate that the dose information that provides the tomograph underestimates the dose between 32 and 35%.

  8. Hanford Environmental Dose Reconstruction Project

    International Nuclear Information System (INIS)

    McMakin, A.H.; Cannon, S.D.; Finch, S.M.

    1992-07-01

    The objective of the Hanford Environmental Dose Reconstruction (HEDR) Project is to estimate the radiation doses that individuals and populations could have received from nuclear operations at Hanford since 1944. The TSP consists of experts in environmental pathways, epidemiology, surface-water transport, ground-water transport, statistics, demography, agriculture, meteorology, nuclear engineering, radiation dosimetry, and cultural anthropology. Included are appointed technical members representing the states of Oregon, Washington, and Idaho, a representative of Native American tribes, and an individual representing the public. The project is divided into the following technical tasks. These tasks correspond to the path radionuclides followed from release to impact on humans (dose estimates): Source terms, environmental transport, environmental monitoring data, demography, food consumption, and agriculture, and environmental pathways and dose estimates. Progress is discussed

  9. Dose from drinking water Finland

    International Nuclear Information System (INIS)

    Maekelaeinen, Ilona; Salonen, Laina; Huikuri, Pia; Arvela, Hannu

    1999-01-01

    The dose from drinking water originates almost totally from naturally occurring radionuclides in the uranium-238 series, the most important nuclide being radon-222. Second comes lead-210, and third polonium-210. The mean age-group-weighted dose received by ingestion of drinking water is 0.14 mSv per year. More than half of the total cumulative dose of 750 manSv is received by the users of private wells, forming 13% of the population. The most exposed group comprises the users of wells drilled in bedrock, who receive 320 manSv while comprising only 4% of the population. The calculated number of annual cancer incidences due to drinking water is very sensitive to the dose-conversion factors of ingested radon used, as well as to the estimated lung cancer incidences caused by radon released from water into indoor air. (au)

  10. Doses from Medical Radiation Sources

    Science.gov (United States)

    ... Medical Radiation Sources Michael G. Stabin, PhD, CHP Introduction Radiation exposures from diagnostic medical examinations are generally ... of exposure annually to natural background radiation. Plain Film X Rays Single Radiographs Effective Dose, mSv Skull ( ...

  11. Gamma Radiation Doses In Sweden

    International Nuclear Information System (INIS)

    Almgren, Sara; Isaksson, Mats; Barregaard, Lars

    2008-01-01

    Gamma dose rate measurements were performed in one urban and one rural area using thermoluminescence dosimeters (TLD) worn by 46 participants and placed in their dwellings. The personal effective dose rates were 0.096±0.019(1 SD) and 0.092±0.016(1 SD)μSv/h in the urban and rural area, respectively. The corresponding dose rates in the dwellings were 0.11±0.042(1 SD) and 0.091±0.026(1 SD)μSv/h. However, the differences between the areas were not significant. The values were higher in buildings made of concrete than of wood and higher in apartments than in detached houses. Also, 222 Rn measurements were performed in each dwelling, which showed no correlation with the gamma dose rates in the dwellings

  12. Extremity doses to interventional radiologists

    International Nuclear Information System (INIS)

    Wihtby, M.; Martin, C. J.

    2002-01-01

    Radiologists performing interventional procedures are often required to stand close to the patient's side when carrying out manipulations under fluoroscopic control. This can result in their extremities receiving a high radiation dose, due to scattered radiation. These doses are sometimes high enough to warrant that the radiologist in question be designated a classified radiation worker. Classification in the UK is a result of any worker receiving or likely to receive in the course of their duties in excess of 3/10ths of any annual dose limit (500mSv to extremities, skin). The doses to the legs of radiologists have received less attention than those to the hands, however the doses may be high, due to the proximity of the legs and feet to scattered radiation. The legs can be exposed to a relatively high level of scattered radiation as the radiation in produced from scatter of the un attenuated beam from the bottom of the patient couch. The routine monitoring of extremity doses in interventional radiology is difficult due to several factors. Firstly a wide range of interventional procedures in undertaken in every radiology department, and these procedures require many different techniques, equipment and skills. This means that the position the radiologist adopts in relation to scattering medium and therefore their exposure, depends heavily on the type of procedure. As the hands which manipulate the catheters within the patient are often located close to the patients side and to the area under irradiation, the distribution of dose across the hands can be variable, with very high localised doses, making routine monitoring difficult. The purpose of this study was to determine the magnitude and distribution of dose to the hands and legs of interventional radiologists carrying out a wide range of both diagnostic and therapeutic interventional procedures. To ascertain the most effective method of monitoring the highest dose in accordance with the Basic safety standards

  13. Dose Distribution of Gamma Irradiators

    International Nuclear Information System (INIS)

    Park, Seung Woo; Shin, Sang Hun; Son, Ki Hong; Lee, Chang Yeol; Kim, Kum Bae; Jung, Hai Jo; Ji, Young Hoon

    2010-01-01

    Gamma irradiator using Cs-137 have been widely utilized to the irradiation of cell, blood, and animal, and the dose measurement and education. The Gamma cell 3000 Elan (Nordion International, Kanata, Ontario, Canada) irradiator was installed in 2003 with Cs-137 and dose rate of 3.2 Gy/min. And the BioBeam 8000 (Gamma-Service Medical GmbH, Leipzig, Germany) irradiator was installed in 2008 with Cs-137 and dose rate of 3.5 Gy/min. Our purpose was to evaluate the practical dosimetric problems associated with inhomogeneous dose distribution within the irradiated volume in open air state using glass dosimeter and Gafchromic EBT film dosimeter for routine Gamma irradiator dosimetry applications at the KIRAMS and the measurements were compared with each other. In addition, an user guideline for useful utilization of the device based on practical dosimetry will be prepared. The measurement results of uniformity of delivered dose within the device showed variation more than 14% between middle point and the lowest position at central axis. Therefore, to maintain dose variation within 10%, the criteria of useful dose distribution, for research radiation effects, the irradiated specimen located at central axis of the container should be placed within 30 mm from top and bottom surface, respectively. In addition, for measurements using the film, the variations of dose distribution were more then 50% for the case of less than 10 second irradiation, mostly within 20% for the case of more than 20 second irradiation, respectively. Therefore, the irradiation experiments using the BioBeam 8000 irradiator are recommended to be used for specimen required at least more than 20 second irradiation time.

  14. Calculating radiation exposure and dose

    International Nuclear Information System (INIS)

    Hondros, J.

    1987-01-01

    This paper discusses the methods and procedures used to calculate the radiation exposures and radiation doses to designated employees of the Olympic Dam Project. Each of the three major exposure pathways are examined. These are: gamma irradiation, radon daughter inhalation and radioactive dust inhalation. A further section presents ICRP methodology for combining individual pathway exposures to give a total dose figure. Computer programs used for calculations and data storage are also presented briefly

  15. Dose assessment at Bikini Atoll

    International Nuclear Information System (INIS)

    Robison, W.L.; Phillips, W.A.; Colsher, C.S.

    1977-01-01

    Bikini Atoll is one of two sites in the northern Marshall Islands that was used by the United States as testing grounds for the nuclear weapons program from 1946 to 1958. In 1969 a general cleanup began at Bikini Atoll. Subsistence crops, coconut and Pandanus fruit, were planted on Bikini and Eneu Islands, and housing was constructed on Bikini Island. A second phase of housing was planned for the interior of Bikini Island. Preliminary data indicated that external gamma doses in the interior of the island might be higher than in other parts of the island. Therefore, to select a second site for housing on the island with minimum external exposure, a survey of Bikini Atoll was conducted in June 1975. External gamma measurements were made on Bikini and Eneu Islands, and soil and vegetations samples collected to evaluate the potential doses via terrestrial food chains and inhalation. Estimates of potential dose via the marine food chain were based upon data collected on previous trips to the atoll. The terrestrial pathway contributes the greater percentage, external gamma exposure contributes the next highest, and inhalation and marine pathways contribute minor fractions of the total whole body and bone marrow doses. The radionuclides contributing the major fraction of the dose are 90 Sr and 137 Cs. All living patterns involving Bikini Island exceed federal guidelines for 30-yr population doses. The Eneu Island living pattern leads to doses that are slightly less than federal guidelines. All patterns evaluated for Bikini Atoll lead to higher doses than those on the southern islands at Enewetak Atoll

  16. Personnel external dose monitoring system

    International Nuclear Information System (INIS)

    Zhao Hengyuan

    1989-01-01

    The status and trend of personnel external dose monitoring system are introduced briefly. Their characteristics, functions and TLD bedges of some commercially available automatic TLD system, including UD-710A (Matsushita, Japan), Harshaw-2271, 2276 (Harshaw, USA), Harshaw-8000 (Harshaw/Filtrol), Studsvik-1313 (Sweden) and Pitman-800 (UK) were depicted in detail. Finally, personnel dose management and record keeping system were presented and two examples were given

  17. Weldon Spring historical dose estimate

    International Nuclear Information System (INIS)

    Meshkov, N.; Benioff, P.; Wang, J.; Yuan, Y.

    1986-07-01

    This study was conducted to determine the estimated radiation doses that individuals in five nearby population groups and the general population in the surrounding area may have received as a consequence of activities at a uranium processing plant in Weldon Spring, Missouri. The study is retrospective and encompasses plant operations (1957-1966), cleanup (1967-1969), and maintenance (1969-1982). The dose estimates for members of the nearby population groups are as follows. Of the three periods considered, the largest doses to the general population in the surrounding area would have occurred during the plant operations period (1957-1966). Dose estimates for the cleanup (1967-1969) and maintenance (1969-1982) periods are negligible in comparison. Based on the monitoring data, if there was a person residing continually in a dwelling 1.2 km (0.75 mi) north of the plant, this person is estimated to have received an average of about 96 mrem/yr (ranging from 50 to 160 mrem/yr) above background during plant operations, whereas the dose to a nearby resident during later years is estimated to have been about 0.4 mrem/yr during cleanup and about 0.2 mrem/yr during the maintenance period. These values may be compared with the background dose in Missouri of 120 mrem/yr

  18. Technical basis for dose reconstruction

    International Nuclear Information System (INIS)

    Anspaugh, L.R.

    1996-01-01

    The purpose of this paper is to consider two general topics: Technical considerations of why dose-reconstruction studies should or should not be performed and methods of dose reconstruction. The first topic is of general and growing interest as the number of dose-reconstruction studies increases, and one asks the question whether it is necessary to perform a dose reconstruction for virtually every site at which, for example, the Department of Energy (DOE) has operated a nuclear-related facility. And there is the broader question of how one might logically draw the line at performing or not performing dose-reconstruction (radiological and chemical) studies for virtually every industrial complex in the entire country. The second question is also of general interest. There is no single correct way to perform a dose-reconstruction study, and it is important not to follow blindly a single method to the point that cheaper, faster, more accurate, and more transparent methods might not be developed and applied. 90 refs., 4 tabs

  19. Weldon Spring historical dose estimate

    Energy Technology Data Exchange (ETDEWEB)

    Meshkov, N.; Benioff, P.; Wang, J.; Yuan, Y.

    1986-07-01

    This study was conducted to determine the estimated radiation doses that individuals in five nearby population groups and the general population in the surrounding area may have received as a consequence of activities at a uranium processing plant in Weldon Spring, Missouri. The study is retrospective and encompasses plant operations (1957-1966), cleanup (1967-1969), and maintenance (1969-1982). The dose estimates for members of the nearby population groups are as follows. Of the three periods considered, the largest doses to the general population in the surrounding area would have occurred during the plant operations period (1957-1966). Dose estimates for the cleanup (1967-1969) and maintenance (1969-1982) periods are negligible in comparison. Based on the monitoring data, if there was a person residing continually in a dwelling 1.2 km (0.75 mi) north of the plant, this person is estimated to have received an average of about 96 mrem/yr (ranging from 50 to 160 mrem/yr) above background during plant operations, whereas the dose to a nearby resident during later years is estimated to have been about 0.4 mrem/yr during cleanup and about 0.2 mrem/yr during the maintenance period. These values may be compared with the background dose in Missouri of 120 mrem/yr.