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Sample records for tbp-mic determinacion espectrofotometrica

  1. Spectrophotometric Determination of Microamounts of Uranium previous Extraction with TBP-MIC; Determinacion Espectrofotometrica de Microcantidades de Uranio previa extraccin con Metilisobutilcetona-Fosfato de Tributilo

    Energy Technology Data Exchange (ETDEWEB)

    Vera Palomino, J.; Palomares Delgado, F.; Petrement, J.; Fernandez Cellini, R.

    1962-07-01

    Selective extraction of uranium in nitric acid medium with a mixture of Tbp-MIC (1:10) has been achieved. Aluminium nitrate was used as salting agent. Complexing agents were added in order to avoid extraction of impurities. Extraction conditions have been studied so that extraction is almost practically complete in a single run. (Author) 19 refs.

  2. Spectrophotometric Determination of Microamounts of Uranium previous Extraction with TBP-MIC

    International Nuclear Information System (INIS)

    Vera Palomino, J.; Palomares Delgado, F.; Petrement, J.; Fernandez Cellini, R.

    1962-01-01

    Selective extraction of uranium in nitric acid medium with a mixture of Tbp-MIC (1:10) has been achieved. Aluminium nitrate was used as salting agent. Complexing agents were added in order to avoid extraction of impurities. Extraction conditions have been studied so that extraction is almost practically complete in a single run. (Author) 19 refs

  3. Spectrophotometric determination of silica in water. Low range; Determinacion espectrofotometrica de silicio en aguas. Rango bajo

    Energy Technology Data Exchange (ETDEWEB)

    Acosta L, E. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)]. e-mail: eal@nuclear.inin.mx

    1992-07-15

    The spectrophotometric method for the determination of the silica element in water, demineralized water, raw waters, laundry waters, waters treated with ion exchange resins and sea waters is described. This method covers the determination of the silica element in the interval from 20 to 1000 {mu}g/l on 50 ml. of base sample. These limits its can be variable if the size of the used aliquot one is changed for the final determination of the silica element. (Author)

  4. Spectrophotometric determination of silica in water with Hach equipment; Determinacion espectrofotometrica de silicio en aguas con equipo Hach

    Energy Technology Data Exchange (ETDEWEB)

    Acosta L, E. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)]. e-mail: eal@nuclear.inin.mx

    1992-06-15

    The method for the determination of the silica element in water, demineralized water, raw waters, laundry waters, waters treated with ion exchange resins and sea waters using the indicated technique in the operation manual of the Hach equipment with a DR/3 spectrophotometer is described. This method covers the determination of the silica element in the interval from 0 to 1.5 mg/l on 50 ml. of base sample. These limits its can be variable if the size of the used aliquot one is changed for the final determination of the silica element. (Author)

  5. Spectrophotometric determination of fluorides in water with Hach equipment; Determinacion espectrofotometrica de fluoruros en aguas con equipo Hach

    Energy Technology Data Exchange (ETDEWEB)

    Acosta L, E. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)]. e-mail: eal@nuclear.inin.mx

    1994-11-15

    The spectrophotometric method for the determination of the fluoride ion in water, demineralized water, raw waters, laundry waters and waters treated with ion exchange resins , using the technique and the SPADNS coloring indicated in the operation manual of the Hach equipment is described. This method covers the determination of the fluoride ion in the range from 0 to 2 mg/l on 25 ml. of radioactive base sample. These limits can be variable if the size of the used aliquot one is changed for the final determination of the fluoride ion. (Author)

  6. Spectrophotometric determination of zinc in impure solutions; Determinacion Espectrofotometrica de Zinc en muestras de rio-Tinto prvia estracciond el Ditizonato con Tetracloruro

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Hernandez, B.; Reyes Tamaral, A.

    1972-07-01

    A dithizone colorimetric method is described for determining zinc concentrations of 0.001 to 5 g/l in aqueous solutions from Rio Tinto Mines, containing copper, iron and other impurities. Citrate, cyanide and bis-(2hydroxyethyl)-dithiocarbamate are added to the aqueous sample of masking several metals, and zinc is extracted at pH 5 with a solution of dithizone in carbon tetrachloride. Excess of dithizone is removed with sodium sulphide, and optical density of zinc dithionate in organic solution is measured at 5.35 nm. Calibration curves obey Beer's law up to 0.5 micro Zn/ml. (Author) 5 refs.

  7. Spectrophotometric determination of aluminium in presence of iron with eriochrome cyanine R. Essays with a decolorated reagent; Determinacion espectrofotometrica de aluminio en presencia de hierro con eriocromocianina R. Ensayos con un reactivo decolorado

    Energy Technology Data Exchange (ETDEWEB)

    Barrachina Gomez, M.; Gasco Sanchez, L.; Fernandez Cellini, R.

    1962-07-01

    The behaviour of the extinction coefficient of aqueous solutions of Eriochrome Cyanine R is studied. It is found that at pH 5-6 the diluted acid solutions decolorate rapidly according to an exponential law (538 m{mu}). The fact that the decoloree solutions go on still reacting with the aluminium has. (Author) 12 refs.

  8. Spectrophotometric determination of uranium with arsenazo previous liquid-liquid extraction and colour development in organic medium; Determinacion espectrofotometrica de uranio con arsenazo, previa extraccion y desarrollo del color en medio organico

    Energy Technology Data Exchange (ETDEWEB)

    Palomares Delgado, F.; Vera Palomino, J.; Petrement Eguiluz, J. C.

    1964-07-01

    The determination of uranium with arsenazo is hindered by a great number of cation which form stable complexes with the reactive and may given rise to serious interferences. By studying the optimum conditions of uranium the extraction be means of tributylphosphate solutions dissolved in methylisobuthylketone, under conditions for previous masking of the interfering cations, an organic extract was obtained containing all the uranium together with small amounts of iron. The possible interference derived from the latter element is avoided by reduction with hydroxylammoniumchlorid followed by complex formation of the Fe(II)-ortophenantroline compound in alcoholic medium. (Author) 17 refs.

  9. Algunas determinaciones del pregnandiol urinario en el aborto amenazante

    OpenAIRE

    Castillo Vega, Eudoro

    2011-01-01

    El presente trabajo tiene por objeto hacer algunas "determinaciones del pregnandiol urinario en enfermas con síntomas evidentes de aborto amenazante", o bien, en enfermas en cuya historia anamnésica se encuentre el antecedente de uno o más abortos anteriores, así como también de partos prematuros y que, ni en los primeros ni en los últimos se haya encontrado una causa bien determinada. En lo posible, se han escogido pacientes con antecedente Serológico Negativo y de constitución topográfica a...

  10. Algunas determinaciones del pregnandiol urinario en el aborto amenazante

    Directory of Open Access Journals (Sweden)

    Eudoro Castillo Vega

    1956-07-01

    Full Text Available El presente trabajo tiene por objeto hacer algunas "determinaciones del pregnandiol urinario en enfermas con síntomas evidentes de aborto amenazante", o bien, en enfermas en cuya historia anamnésica se encuentre el antecedente de uno o más abortos anteriores, así como también de partos prematuros y que, ni en los primeros ni en los últimos se haya encontrado una causa bien determinada. En lo posible, se han escogido pacientes con antecedente Serológico Negativo y de constitución topográfica anatómica, en cuanto a pelvis se refiere, normales. Es de lógica que, a una enferma con una desviación uterina o con un tumor pélvico, no se puede achacar el aborto a deficiencia de Progesterona o de cualquiera otra hormona, pues la causa es verdaderamente objetiva.

  11. Contributions te the study of methods and factors affecting the spectrophotometric determination of boron traces with carmin uranium compounds; Contribucion al estudio del metodo y factores que afectan a la determinacion espectrofotometrica de trazas de boro con Carmin en compuestos de uranio

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez Cellini, R.; Gasco Sanchez, L.

    1956-07-01

    The study of some factors affecting the spectrophotometric determination of boron traces with carmin is made; the influence of carmin from different origin, the stability of complex carmin-boric acid in relation with the sulphuric acid concentration, the interference produced by ion nitrate, and the ion uraline and light influence are discussed. (Author) 36 refs.

  12. Estudio de la variabilidad edáfica de algunas determinaciones químicas a traves de un muestreo compuesto

    OpenAIRE

    Vázquez, Mabel Elena; Leroux, G.

    1983-01-01

    p.7-13 Se muestreo una superficie de una hectárea hasta los 18 cm de profundidad, de un suelo caracterizado como Argialbol Argiacuico, ubicado en el Partido de Luján, Provincia de Buenos Aires. El muestreo puntual fue sistemático con diagrama de cuadrícula, extrayéndose un total de 49 muestras que integraron en forma aleatoria 3 repeticiones de muestras compuestas de 10, 20, 30, 40 y 49 submuestras. Sobre ellas se realizaron las siguientes determinaciones: N-NO3 , P extractable, capacidad ...

  13. Variabilidad espacial en determinaciones de carbono, nitrógeno, fósforo y ph, de un muestreo sistemático de suelo

    OpenAIRE

    Conti, Marta Elvira; Arrigo, Nilda Marta; Palma, Rosa Martha

    1980-01-01

    p.43-48 En una unidad taxonómica planosol somero, se realizó un muestreo sistemático tridimensional. Se obtuvieron 100 muestras en una cuadrícula diseñada sobre una hectárea. En el ensayo se incorporaron dos fuentes de variabilidad: a) distinta profundidad, b) distintos manejos. Sobre ellos se realizaron las determinaciones de carbono total, nitrógeno total, fósforo asimilable, pH actual y pH potencial. En todos los casos se describe la población a través de su media muestral, varianza y c...

  14. Del confesionario a Freud : hipótesis provocativa sobre las determinaciones sociales en el surgimiento del psicoanálisis

    OpenAIRE

    Ozollo, Javier

    2015-01-01

    El artículo pretende ejemplificar, para el caso del psicoanálisis y en líneas generales, la relación entre sociedad y conocimiento. Es decir, se pone en relación los núcleos centrales de un nuevo descubrimiento o, en términos más correctos, de una nueva ruptura con las determinaciones sociales en última instancia. Así, se describen los puntos medulares del descubrimiento de Freud y se analiza la correlación existente con lo...

  15. The need of alkalinity determination in the characterization of rain; Necesidad de la determinacion de la alcalinidad en la caracterizacion de la lluvia

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-01-01

    In this paper is presented the alkalinity determination of the carbonic species in the rain waters by the Gran titration method. The alkalinity values obtained by this method in low electric conductivity waters are fairly reliable. Also, the existing studies on the characterization of acid rains, are discussed. [Espanol] En este trabajo se presenta la medicion de la alcalinidad y la determinacion de las especies carbonicas en las aguas de lluvia por el metodo de la titulacion de Gran. Los valores de alcalinidad obtenidos por este metodo en las aguas de baja conductividad electrica son bastante confiables. Asimismo, se discuten los estudios existentes sobre la caracterizacion de la lluvia acida en la republica mexicana.

  16. Determinaciones termogravimétricas y de calor específico de un concentrado comercial de ulexita, entre temperatura ambiente y 1.000 ºC

    Directory of Open Access Journals (Sweden)

    Flores, H. R.

    2006-12-01

    Full Text Available The important amount of hydration water in the ulexite (NaCaB5O9.8H2O, allows using calcination methods to increase its B2O3 content. This paper analyses the thermal decomposition reaction of a preconcentrated ulexite through weight loss measurements, which occur during the heating of samples until 1000 ºC. Determinations of heat content at each temperature were made using an isoperibol calorimeter. The mean specific heat was calculated from these values, and its dependence on temperature was determined. The maximum weight loss was about 32.5 % and the specific heat obtained was 1,13 kJ/kgºC for solid samples and 1,38 kJ/kgºC for fluid samples.The results are useful for the design of the industrial process, in order to determine the thermal requirements for heating calcined ulexite, and to obtain smelted ulexite.

    El elevado contenido de agua de hidratación de la ulexita (NaCaB5O9.8H2O permite utilizar la calcinación como método de concentración. En este trabajo se analiza la reacción de descomposición térmica de un preconcentrado de ulexita a través de determinaciones de la pérdida de peso ocurrida durante el calentamiento de la muestra hasta 1000 ºC. Por otra parte, se ha determinado el valor del calor sensible a cada temperatura ensayada mediante un calorímetro tipo isoperibol y se ha calculado el calor específico medio de la muestra calcinada, así como su variación con la temperatura. Se obtuvieron pérdidas de peso de 32,5 % y valores del calor específico de 1,13 kJ/kgºC para muestras sólidas y 1,38 kJ/kgºC para las fluidas. Los resultados son de utilidad para el diseño del proceso industrial, para la determinación del requerimiento térmico para el calentamiento de ulexita calcinada y para la obtención de una frita.

  17. Determinaciones coulométricas sobre probetas de cobre expuestas a vapores con bajos contenidos de ácido propiónico

    Directory of Open Access Journals (Sweden)

    Alejandro Echavarría

    2004-01-01

    Full Text Available En el presente estudio se evaluó el efecto de tres concentraciones de vapor de ácido propiónico (260, 380 y 680 partes por billón en volumen, ppbv en una corriente de aire a 30 °C y 90% de humedad relativa sobre el deterioro del cobre, mediante la determinación de la carga total requerida para reducir los compuestos formados, utilizando la técnica de la reducción coulométrica según norma ASTM B-825-97. Los ensayos electroquímicos se realizaron para 7, 14 y 21 días de exposición. Además, se hicieron determinaciones gravimétricas a los 21 días de exposición, según norma ASTM G1-90, para comparar la velocidad de corrosión con los resultados electroquímicos. Las exposiciones se realizaron en una cámara climática con controles electrónicos de temperatura y de humedad relativa a un flujo de aire constante de 4 L/min. El contaminante fue agregado al flujo del aire mediante tubos de emisión de ácido propiónico con diferentes aberturas de emisión y certificados gravimétricamente a 2.650, 3.750 y 6.900 ng/min. Los resultados mostraron diferencias estadísticas (con 95% de confiabilidad para la carga requerida en la reducción total de los óxidos entre los 7 y 21 días de exposición y que ésta también aumenta con el nivel de contaminante, indicando que los productos de corrosión crecen con el tiempo de exposición y con el aumento en la concentración del ácido. Particularmente se encontró que la técnica de reducción coulométrica es más confiable que la gravimétrica para evaluar la velocidad de corrosión en estos ambientes, típicos de atmósferas de muy baja agresividad. En la técnica gravimétrica, la remoción de metal base inherente al proceso de decapado ácido es del mismo orden de magnitud con respecto al de los productos formados en el proceso de corrosión, conduciendo a alta dispersión de los resultados

  18. Determining the optimal dose of Fenton reagent in a leachate treatment by Fenton-adsorption; Determinacion de la dosis optima de reactivo Fenton en un tratamiento de lixiviados por Fenton-adsorcion

    Energy Technology Data Exchange (ETDEWEB)

    Mendez Novelo, Roger Ivan; Pietrogiovanna Bronca, Jose Alfredo; Santos Ocampo, Beatriz; Sauri Riancho, Maria Rosa; Giacoman Vallejos, German; Castillo Borges, Elba Rene [Universidad Autonoma de Yucatan, Facultad de Ingenieria, Merida, Yucatan (Mexico)]. E-mail: mnovelo@uady.mx

    2010-07-01

    tipo Fenton-adsorcion con el que se obtuvieron mejores resultados que con otros tratamientos fisicoquimicos o biologicos reportados en la literatura. El proceso Fenton consiste en tratar la carga contaminante con una combinacion de H{sub 2}O{sub 2} y FeSO4 en condiciones acidas. Se evaluo si la filtracion de los lodos producidos durante el proceso Fenton es un proceso mas eficiente que la sedimentacion. Se determino el tiempo de contacto optimo de la oxidacion Fenton, asi como la dosis optima de los reactivos usados en funcion de la DQO del lixiviado, mediante la determinacion de las mejores relaciones [Fe{sup 2+}]/[H{sub 2}O{sub 2}] y [DQO]/[H{sub 2}O{sub 2}]. Despues de optimizar el proceso, se filtraron las muestras oxidadas y se ensayo la adsorcion mediante columnas empacadas con carbon activado granular. Se concluyo que el lodo generado por el proceso Fenton se remueve mas eficientemente mediante filtracion que por sedimentacion. Los tiempos de contacto optimos fueron de 5 min para la remocion de la DQO y una hora para la remocion de color, tiempo elegido para proteger el carbon activado. Las mejores relaciones para [Fe{sup 2+}]/[H{sub 2}O{sub 2}] y [DQO]/[H{sub 2}O{sub 2}] fueron 0.6 y 9, respectivamente. La eficiencia maxima de remocion despues del proceso de adsorcion fue de 98.9 % para la DQO y 100 % para el color. El indice de biodegradabilidad final alcanzado despues de las pruebas de Fenton-adsorcion fue de 0.24.

  19. Volatile organic compounds determination in the atmosphere of Mexico City by the use of optical systems and non conventional methods; Determinacion de compuestos organicos volatiles en la atmosfera de la Ciudad de Mexico mediante el uso de sistemas opticos y metodos convencionales

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz, Maria Esther; Arriaga, Jose Luis; Garcia, Isidoro [Gerencia de Ciencias de Ambiente, Instituto Mexicano del Petroleo, Mexico, D.F. (Mexico)

    1996-04-01

    . Las tres tecnicas ofrecen diferentes ventajas para la determinacion de las especies en la atmosfera, las muestras en canisteres nos dan la concentracion total de los COV y la concentracion de mas de 200 especies diferentes asi como tambien permiten la determinacion de CO y CH{sub 4}. El muestreo en cartuchos puede utilizarse para detectar emisiones ocasionales. Por otro lado el DOAS es un medio para seguir la evolucion de especies selectas durante periodos largos que permite analizar la influencia de los parametros meteorologicos como la velocidad y direccion del viento, sobre la concentracion de cada contaminante. Los resultados que aqui se presentan se obtuvieron mediante la colaboracion del grupo de Ciencias del Ambiente del Instituto Mexicano del Petroleo (GCA-IMP) con otros grupos.

  20. The federal law of the Revenue Agency responsibility, the national oil industry and the determination of the average price of the Mexican mixture for export: implications and limitations; La ley federal de responsabilidad hacendaria, la industria petrolera nacional y la determinacion del precio promedio de la mezcla mexicana de exportacion: implicaciones y limitaciones

    Energy Technology Data Exchange (ETDEWEB)

    Baltierra, Lauro; Huerta, Carlos E.; Ruiz Alarcon, Fluvio Cesar [LX legislatura, Camara de Diputados, Mexico, D.F. (Mexico)

    2006-11-15

    en la economia del pais, al propiciar un proceso de financiarizacion del sector, asi como las implicaciones que se originan de la fijacion inamovible del precio del petroleo por disposicion legal. Como ello limita las potestades constitucionales de la Camara de Diputados al negarle la facultad, que ejercia hasta la expedicion de la Ley, para evaluar las estimaciones del Ejecutivo Federal respecto al precio promedio de la mezcla mexicana de exportacion. En el primer apartado se realiza un balance de como el Presupuesto de Egresos de la Federacion se proyecta como un instrumento para frenar la inversion publica en el sector petrolero. En el segundo se atienden aspectos relacionados con la estimacion de precio del petroleo a partir de la Ley de Federal de Presupuesto y Responsabilidad Hacendaria, senalando las incongruencias que significa establecer una formula para la determinacion del mismo. En un tercer apartado, se tratan la subvaluacion de los precios del crudo como factor clave para el uso discrecional de los excedentes petroleros. En el cuarto apartado, se analizan los Criterios Generales de Politica Economica para el ano 2007, que conforme a la nueva Ley Federal de Presupuesto y Responsabilidad Hacendaria fueron remitidos a la Camara de Diputados por el Ejecutivo Federal en el mes de abril. Por ultimo, se presentan las estimaciones de la mezcla mexicana de exportacion para 2007 que a consideracion de los autores oscilara entre 50 y 51 dolares como promedio anual.

  1. Determination of heat losses in the Cerro Prieto, Baja California, geothermal field steam transportation network based on the thermal insulation condition of the steam pipelines; Determinacion de perdidas de calor en la red de transporte de vapor del campo geotermico de Cerro Prieto, Baja California, con base en el estado fisico del aislamiento termico de vaporductos

    Energy Technology Data Exchange (ETDEWEB)

    Ovando Castelar, Rosember; Garcia Gutierrez, Alfonso; Martinez Estrella, Juan Ignacio [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)]. E-mail: rovando@iie.org.mx; Canchola Felix, Ismael; Jacobo Galvan, Paul; Miranda Herrera, Carlos; Mora Perez, Othon [Comision Federal de Electricidad, Gerencia de Proyectos Geotermoelectricos, Residencia General de Cerro Prieto, Mexicali, B.C. (Mexico)

    2011-07-15

    . En este trabajo se analiza el impacto del estado fisico del aislamiento termico sobre las perdidas de calor en las tuberias de la red de vaporductos del CGCP y se estima la magnitud de estas perdidas mediante la aplicacion de un metodo iterativo. Este metodo permitio determinar la temperatura de superficie con base en un balance de calor que considera los tres mecanismos basicos de transferencia de calor: conduccion, conveccion y radiacion termica. Finalmente, con base en la determinacion de longitudes y diametros para cada estado de aislamiento de los vaporductos y en las condiciones de operacion globales de la red, se cuantifican las perdidas de calor a traves de los aislantes para toda la red de transporte. Los resultados obtenidos permitieron evaluar la magnitud de estas perdidas en comparacion con la perdida global de energia que ocurre durante el transporte de vapor desde los pozos hasta las plantas de generacion electrica.

  2. Solvent. I. Extraction systems applied to uranium analysis. I. Extraction studies with Tributyl phosphate-Methyl-isobutyl-ketone; Metodos de extraccion don disolventes aplicados al analisis quimico del uranio. I. Estudio de la extraccion con fosfato de tributilo-metilisobutilcetano

    Energy Technology Data Exchange (ETDEWEB)

    Vera Palomino, J.; Palomares Delgado, F.; Petrement Eguiluz, J. C.

    1964-07-01

    A factorial study of the selective extraction of uranium with a mixture of TBP-MIC was carried out using 0,8 N nitric acid and different salting agents. We use the most suitable salting agent to develop new factorial experiments in order to get an equation involving the percent of extracted uranium, E, the concentration of the extraction agent in the organic phase, c, and the concentration of the slating agent in the aqueous phase, n. (Author) 3 refs.

  3. Solvent. I. Extraction systems applied to uranium analysis. I. Extraction studies with Tributyl phosphate-Methyl-isobutyl-ketone

    International Nuclear Information System (INIS)

    Vera Palomino, J.; Palomares Delgado, F.; Petrement Eguiluz, J. C.

    1964-01-01

    A factorial study of the selective extraction of uranium with a mixture of TBP-MIC was carried out using 0,8 N nitric acid and different salting agents. We use the most suitable salting agent to develop new factorial experiments in order to get an equation involving the percent of extracted uranium, E, the concentration of the extraction agent in the organic phase, c, and the concentration of the slating agent in the aqueous phase, n. (Author) 3 refs

  4. Optical signal response pf the alanine gel solution for photons and electrons clinical beams;Resposta espectrofotometrica da solucao gel de alanina para feixes clinicos de fotons e eletrons

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Cleber Feijo; Campos, Leticia Lucente [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2009-07-01

    Alanine gel dosimeter is a new gel material developed at IPEN that presents significant improvement on previous alanine systems developed by Costa (1994). The measure technique is based on the transformation of ferrous ions (Fe{sup 2+}) in ferric ions (Fe{sup 3+}) after irradiation. The DL-Alanine (C{sub 3}H{sub 7}NO{sub 2}) is an aminoacid tissue equivalent that improves the production of ferric ions in the solution. This work aims to study the comparison of optical signal response of the alanine gel solution for photons and electrons clinical beams. It was observed that the calibration factor can be considered independent of quality of the radiation for photons and electrons clinical beams. Therefore, it can be used the same calibration factor for evaluating the absorbed dose in photons and electrons fields in the energy of 6 MeV. Alanine Gel Dosimeter presents good performance and can be useful as alternative dosimeter in the radiotherapy area using MRI technique for 3D dose distribution evaluation. (author)

  5. Dosimetric evaluation of spectrophotometric response of alanine gel solution for gamma, photons, electrons and thermal neutrons radiations; Avaliacao dosimetrica da resposta espectrofotometrica da solucao gel de alanina para radiacao gama, de fotons, de eletrons e de neutrons termicos

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Cleber Feijo

    2009-07-01

    Alanine Gel Dosimeter is a new gel material developed at IPEN that presents significant improvement on Alanine system developed by Costa. The DL-Alanine (C{sub 3}H{sub 7}NO{sub 2}) is an amino acid tissue equivalent that improves the production of ferric ions in the solution. This work aims to analyse the main dosimetric characteristics this new gel material for future application to measure dose distribution. The performance of Alanine gel solution was evaluated to gamma, photons, electrons and thermal neutrons radiations using the spectrophotometry technique. According to the obtained results for the different studied radiation types, the reproducibility intra-batches and inter-batches is better than 4% and 5%, respectively. The dose response presents a linear behavior in the studied dose range. The response dependence as a function of dose rate and incident energy is better 2% and 3%, respectively. The lower detectable dose is 0.1 Gy. The obtained results indicate that the Alanine gel dosimeter presents good performance and can be useful as an alternative dosimeter in the radiotherapy area, using MRI technique for tridimensional dose distribution evaluation. (author)

  6. Thermographic and spectrophotometric analysis of the extrinsic tooth bleaching using a diode laser and a LED system. In vitro; Analise termografica e espectrofotometrica do clareamento dental extrinsico utilizando laser de diodo e sistema de LED. Estudio In vitro

    Energy Technology Data Exchange (ETDEWEB)

    Micheli, Paola Racy de

    2004-07-01

    The aim of this study was to evaluate the intra-pulpal temperature change, as well as to compare the bleaching power of a 38% hydrogen peroxide (Opalescence Xtra Boost- Ultradent. Inc), when activated with a diode laser, with a LED system and without activation, in the extrinsic tooth bleaching in vitro. Ten mandibular human incisors, a thermocouple, 45 bovine incisors and a spectrophotometer (Shade Eye- Shofu) for the color analysis. The samples were divided into 3 groups: 38% hydrogen peroxide activated by a diode laser (ZAP lasers, wavelength 808 nm {+-} 5, power of 1,4 W); 38% hydrogen peroxide activated by LED (Bright LEC-Mmoptics, wavelength 470 nm {+-} 25, power of 380 mW); 38% hydrogen peroxide without activation. After the artificial pigmentation, the bleaching agent acted for the same time in the 3 groups, differing only by the type of activation. The results of temperature showed that the LED activation was safer than the diode laser, which, in some measures exceeded the limit of 5.6 deg C. The luminosity of the samples did not show significantly statistics differences in none of the groups and moments of this study. The diode laser and LED activation did not influenced at the bleaching power of the peroxide, which showed effective for removing stains, with great capacity of bleaching bovine tooth artificially darkened. (author)

  7. Determination of Pu in soil samples; Determinacion de Pu en muestras de suelo

    Energy Technology Data Exchange (ETDEWEB)

    Torres C, C. O.; Hernandez M, H.; Romero G, E. T. [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Vega C, H. R., E-mail: carioli_32907@hotmail.com [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas, Zac. (Mexico)

    2016-10-15

    The irreversible consequences of accidents occurring in nuclear plants and in nuclear fuel reprocessing sites are mainly the distribution of different radionuclides in different matrices such as the soil. The distribution in the superficial soil is related to the internal and external exposure to the radiation of the affected population. The internal contamination with radionuclides such as Pu is of great relevance to the nuclear forensic science, where is important to know the chemical and isotopic compositions of nuclear materials. The objective of this work is to optimize the radiochemical separation of plutonium (Pu) from soil samples and to determine their concentration. The soil samples were prepared using acid digestion assisted by microwave; purification of Pu was carried out with AG1X8 resin using ion exchange chromatography. Pu isotopes were measured using ICP-SFMS. In order to reduce the interference due to the presence of {sup 238}UH {sup +} in the samples, a solvent removal system (Apex) was used. In addition, the limit of detection and quantification of Pu was determined. It was found that the recovery efficiency of Pu in soil samples ranges from 70 to 93%. (Author)

  8. Dose determination in computed tomography; Determinacion de dosis en tomografia computada

    Energy Technology Data Exchange (ETDEWEB)

    Descamps, C.; Garrigo, E.; Venencia, D. [Fundacion Marie Curie, Instituto Privado de Radioterapia, Departamento de Fisica Medica, Obispo Oro 423, X5000BFI Cordoba (Argentina); Gonzalez, M. [Universidad Nacional de Cordoba, Facultad de Ciencias Exactas, Fisicas y Naturales, Av. Velez Sarsfield 299, Corboba (Argentina); Germanier, A., E-mail: agermani@ceprocor.uncor.edu [Ministerio de Ciencia y Tecnologia, Ceprocor, Alvarez de Arenas 230, X5004AAP Barrio Juniors, Cordoba (Argentina)

    2011-10-15

    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%.

  9. Fluorescence uranium determination; Determinacion de uranio por fluorescencia. I. Proyecto de equipo y comprobacion

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez Cellini, R.; Crus Castillo, F. de la; Barrera Pinero, R.

    1960-07-01

    An equipment for analysis of uranium by fluorescence was developed in order to determine it at such a low concentration that it can not be determined by the most sensible analytical methods. this new fluorimeter was adapted to measure the fluorescence emitted by the phosphorus sodium fluoride-sodium carbonate-potasium carbonate-uranyl, being excited by ultraviolet light of 3,650 A the intensity of the light emitted was measure with a photomultiplicator RCA 5819 and the adequate electronic equipment. (Author) 19 refs.

  10. Quantitative spectrographic determination of zirconium minerals; Determinacion espectrografica cuantitative de circonio en minerales

    Energy Technology Data Exchange (ETDEWEB)

    Rocal Adell, M.; Alvarez Gonzalez, F.; Fernandez Cellini, R.

    1958-07-01

    The method described in the following report permits the quantitative determination of zirconium in minerals and rocks in a 0,02-100% of ZrO{sub 2} concentration rate. The excitation is carried out by a 10 ampere continuous current arc among carbon electrodes, and placing the sample in a crater of 2 mm depth. For low concentrations a dilution of the sample with the same weight as its own in carbon powder and with 1/25 of its weight of Co{sub 3}O{sub 4} (internal patron) is carried out. Line Zr 2571,4, Co 2585,3 and Co 2587,2 are used. (Author) 6 refs.

  11. DETERMINACION DEL COEFICIENTE DE DIFUSIÓN DEL AGUA EN SEMILLAS DE AMARANTHUS CRUENTUS REHUMECTADAS

    Directory of Open Access Journals (Sweden)

    María L. Balmaceda

    2015-01-01

    Full Text Available En este trabajo se estima experimentalmente los coeficientes de difusión efectivos de agua en semillas de amaranto rehumectadas para posteriores estudios del rendimiento y calidad del popeado o reventado del grano. Las semillas se rehumectaron por inmersión en agua a temperaturas de 11, 35 y 50 °C durante intervalos de tiempo de 0.5, 1, 2 y 4 h, determinándose gravimétricamente la humedad adquirida en cada condición estudiada. Para estimar el coeficiente de difusión se empleó el modelo difusional basado en la solución analítica de la segunda ley de Fick, considerando a la semilla de amaranto como una esfera de radio 0.6 mm. Se midieron las humedades de equilibrio en las condiciones estudiadas luego de un tiempo de 24 h de rehumectación. Los resultados obtenidos fueron similares a los encontrados por otros autores para semillas de quinua y otras variedades de amaranto, con características semejantes. Los valores de los coeficientes de difusión efectivos aumentaron con el incremento de la temperatura.

  12. Determinacion de periodos fundamentales del suelo mediante vibraciones ambientales en el municipio de Humacao, Puerto Rico

    Science.gov (United States)

    Cintron Aponte, Rommel

    La tecnica de Nakamura ha sido utilizada a nivel mundial para determinar periodos fundamentales del suelo. La tecnica consiste en calcular y graficar cocientes espectrales H/V de vibraciones ambientales registradas sobre el suelo. Mediciones de vibraciones ambientales fueron tomadas en 151 lugares dentro del municipio de Humacao, localizado al este de Puerto Rico. Los datos se procesaron utilizando espectros de Fourier y espectros de potencia. La tecnica fue validada al compararla con los resultados de cocientes espectrales H/V de registros de sismos debiles y tambien con una modelacion numerica realizada con datos de un ensayo "downhole". Las graficas de los cocientes espectrales H/V fueron divididas en casos y grupos, los cuales dependen de la facilidad para identificar el periodo fundamental pico y amplitudes en frecuencias menores de 1 Hz, respectivamente. Los resultados obtenidos con ambos espectros fueron comparados y se concluye que los mismos se complementan para proveer resultados mas confiables. Se crearon mapas de periodos fundamentales, factores de amplitud, isoperiodos y clasificacion sismica de sitio. Los mapas de isoperiodos fueron realizados en las zonas mas pobladas sobre depositos de suelo. El mapa de periodos fundamentales del suelo mostro buena correlacion con la geologia local. El mapa de clasificacion sismica derivado de periodos de sitio fue comparado con el mapa de clasificacion sismica derivado de barrenos geotecnicos. El mapa de clasificacion obtenido de periodos puede sobreestimar un poco algunas clasificaciones del suelo. Sin embargo, este mapa puede proveer un estimado aproximado de la velocidad de onda de corte promedio del suelo hasta una profundidad de 100 pies (30 metros).

  13. Determination of electrodebiles parameters of quark b; Determinacion de los parametros electrodebiles del quark b

    Energy Technology Data Exchange (ETDEWEB)

    Chamizo Llatas, M.

    1995-07-01

    In the present work we analyze the process e{sup e{yields}}bb with the data collected during 1991 and 1992 by the Z,3 detector situated in the LEP e{sup es}torage-ring (CERN). From the measurements of the cross-sections and the charge asymmetry we determine the parameters of the b quark in the framework of the Standard Model. Finally, we parametrize the possible deviations from the model an obtain upper and lower. limits for the mass of the t quark. (Author) 23 refs.

  14. Determination of carbonyl compounds in air by HPLC; Determinacion de compuestos carbonilicos en aire por HPLC

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, S.; Perez, R.M.; Campos, A.; Gonzalez, D.

    1995-07-01

    A method for the determination of seven carbonyl compounds in air is presented. The procedure involve sampling of air by a Sep-Pak Cartridge impregnated with 2,4-dinitrophenylhydrazine. Elution was done with 3 mL of acetonitrile and the eluate was diluted to 5 mL. The analysis was done by HPLC with UV detection and external standard method quantification. It has been achieved relative standard deviations about 5% and detection limits of 80 ng/cartridge for formaldehyde, acetaldehyde and acetoacetonitrile. Three different types of samples (rural, urban, petrol emission) were successfully analyzed. (Author) 12 refs.

  15. Determination of the thermal conductivity of metallic coatings; Determinacion de la conductividad termica de recubrimientos metalicos

    Energy Technology Data Exchange (ETDEWEB)

    Uc Way, Manuel Eugenio

    1998-02-01

    Due to the corrosion by high temperature there is a serious problem of unavailability and efficiency of the steam generators in the thermoelectric power stations. One of the parts that is more affected by this phenomenon is the superheater tube banks. In order to diminish this problem it is intended to apply to these tubes a metallic coating nickel and chromium based (80Ni20Cr), the deposition of the coating is made by the method of thermal spraying of powders by flame. The coating thickness once it has been deposited is of the order of 500mm, it is doubtless that the thermal flow between gases of combustion and the fluid conducted in the tubes is affected. That is why it is important to know the thermal conductivity of the coating in order to evaluate the impact that it has in the operation of the steam generator. This necessity is the one that gives rise to the present thesis project, in which a technique that allows to measure the thermal conductivity of the coating is designed. The experimentation is carried out taking as departure point the ASTM norm E1225-87 and is adapted to the characteristics of the material to prove. A test piece of stainless steel 316 was designed to measure the thermal flow that traverses the coating. First the experimental installation was characterized in order to determine its reliability. Later the experimentation was made finding an average thermal conductivity of 2.09{+-}0.72 W/m K in the temperature interval of 110-180 Celsius degrees. This value is 12.3% inferior to the corresponding one of a solid metal of the same composition. If we consider that in the high temperature banks of the steam generators the thermal flow is in the interval from 15.000 to 100.000 W/m{sup 2} and a coating thickness of the order of 500mm it would cause that this material would introduce a temperature difference of 0.6 to 4 Celsius degrees, respectively. Please note that for the highest thermal flow a maximum affectation of 4 Celsuis degrees is obtained. This value is small when it is compared with the effect that introduces the deposition of slag in these banks of tubes, that is in the order of 50 to 250 Celsuis degrees approximately, for this interval of thermal flows. [Espanol] Debido a la corrosion por alta temperatura se tiene un serio problema por indisponibilidad y eficiencia de los generadores de vapor en las centrales termoelectricas. Una de las partes mas afectadas por este fenomeno son los bancos de tubos de los sobrecalentadores. Con el objeto de disminuir dicho problema se pretende aplicar a los tubos antes mencionados un recubrimiento metalico a base de niquel y cromo (80Ni20Cr), la deposicion del recubrimiento se hace por el metodo de termorrociado de polvos por flama. El espesor del recubrimiento una vez que ha sido depositado es del orden de 500mm, es indudable que el flujo termico entre los gases de combustion y el fluido conducido en los tubos se ve afectado. Por esto es importante conocer la conductividad termica del recubrimiento a fin de evaluar el impacto que se tiene en el funcionamiento del generador de vapor. Esta necesidad es la que da lugar al presente proyecto de tesis, en el cual se disena una tecnica que permite medir la conductividad termica del recubrimiento. La experimentacion se lleva a cabo tomando como punto de partida la norma E1225-87 de la ASTM y se adecua a las caracteristicas del material a probar. Se diseno una probeta de acero inoxidable 316 para medir el flujo termico que atraviesa el recubrimiento. Primero se caracterizo la instalacion experimental a fin de determinar su confiabilidad. Posteriormente se realizo la experimentacion encontrandose una conductividad termica promedio de 12.09{+-}0.72 W/m K en el intervalo de temperatura de 110-180 grados Celsius. Este valor es 12.3% inferior al correspondiente a un metal solido de la misma composicion. Si consideramos que en los bancos de alta temperatura de los generadores de vapor el flujo termico se encuentra en el intervalo de 15,000 a 100,000 W/m2 y un espesor de recubrimiento del orden de 500mm se tendria que dicho material introduciria una diferencia de temperatura de 0.6 a 4 grados Celsius, respectivamente. Notese que para el mas alto flujo termico se tiene una afectacion maxima de 4 grados Celsius. Este valor es pequeno cuando se le compara con el efecto que introduce la deposicion de escoria en dichos bancos de tubos que es del orden de 50 a 250 grados Celsius aproximadamente para dicho intervalo de flujos termicos.

  16. Determination of 230Th in soils; Determinacion de 230Th en suelos

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez, A.; Palomares, J.

    1988-07-01

    A method for the determination of 230Th in environmental soils is described. Hydroxides formed, previous fusion with sodium peroxide are dissolved with HNO3 8N. The thorium is coprecipitated with F3La and purified by anion exchange (AG 1x8 50-100 mesh). Thorium is electroplated onto a stainless steel disc, 230xh is counted by alpha spectrometry and 234'fn u;;ed as tracer by beta counting. The chemical yield for 1g of soil sample is 60-80%. Minimum detectable activities are about 2 mBq/g.

  17. Spectrographic determination of impurities in uranium tetrafluoride; Determinacion espectrografica de impurezas en tetrafluoruro de uranio

    Energy Technology Data Exchange (ETDEWEB)

    Capdevila Perez, C.; Roca Adell, M.; Alvarez Gonzalez, F.

    1967-07-01

    A carrier distillation method for the determination of Ag, Al, As, B, Cd, Cr, Cu, Fe, Mg, Mn, Ni, Pb, and Si in uranium tetrafluoride was develop ped. the previous addition of 25% Y{sub 2}3 prevents the excitation of uranium by conversion of the volatile UF{sub 4} into U{sub 3}0{sub 8} during the arc discharge. NaCl or Ga{sub 2}0{sub 3}, containing Ge and V as internal standards, are used as carriers, and samples are arced in 10 Amp. d.c. arc in a graphite anode cup. 7 mm diameter, 10 mm deep, being the weight of charge 300 mg. (Author) 14 refs.

  18. Spectrographic determination of impurities in magnesium metal; Determinacion espectrografica de impurezas en magnesio

    Energy Technology Data Exchange (ETDEWEB)

    Capdevila, C.; Diaz-Guerra, J. P.

    1979-07-01

    The spectrographic determination of trace quantities of Al, B, Cd, Co, Cr, Cu, Fe, Li, Hn, Mo, Ni and Si in magnesium metal is described. Samples are dissolved with HNO{sub 3} and calcinate into MgO. In order to avoid losses of boron NH{sub 4}OH is added to the nitric solution. Except for aluminium and chromium the analysis is performed through the use of the carrier distillation technique. These two impurities are determined by burning to completion the MgO. Among the compounds studied as carriers (AgCl, AgF, CsCl, CuF{sub 2}, KCl and SrF{sub 2}) AgCl allows, In general, the best volatilization efficiency. Lithium determination is achieved by using KC1 or CsCl. Detection limits, on the basis of MgO, are in the range 0,1 to 30 ppm, depending on the element. (Author) 8 refs.

  19. Determination of the neutron mass; Determinacion de la masa del neutron

    Energy Technology Data Exchange (ETDEWEB)

    Amador V, P.; Chacon R, A.; Arcos P, A.; Rodriguez N, S.; Pinedo S, A.; Vega C, H.R. [Unidad Academica de Estudios Nucleares, Cipres 10, Fracc. La Penuela, 98068 Zacatecas (Mexico)]. e-mail: paus2281@yahoo.com.mx

    2005-07-01

    The binding energy of the deuteron was measured and it was determined the neutron mass starting from the nuclear reaction, {sup 1}{sub 0} n + {sup 1}{sub 1} H {yields}{sup 2}{sub 1} D + {gamma}. The produced photon is soon a gamma ray that is emitted when the hydrogen captures a thermal neutron. The photon energy was measured using two spectrometric systems for gamma rays. A system with a detector of NaI(TI) of 3'' x 3'' and the other one with a High-purity Germanium detector. The first detector has a bigger efficiency and a smaller resolution in comparison with the second detector. The energy of the measured photon is the binding energy of the deuteron. With the measurement of the photon energy and the masses of the proton and of the deuterium it was determined the neutron mass. The value of the mass obtained with both systems it was compared with the value reported in the literature. The nuclear reaction was induced in a volume of paraffin that it was bombing with a source {sup 239} PuBe whose activity is of 3.7 x 10{sup 10} Bq. (Author)

  20. Rapid determination of filamentous microorganisms in activated sludge; Determinacion rapida de microorganismos filamentosos en fangos activados

    Energy Technology Data Exchange (ETDEWEB)

    Arnaiz, C.; Jimenez, C.; Estevez, F. [Empresa Municipal de Abastecimiento y Saneamiento de Aguas de Sevilla (Spain)

    1999-07-01

    Despite many methods available biomass estimation of a bioprocess may sometimes become laborious and impracticable. Samples containing filamentous organisms, as in Wastewater Treatment Plants, present special counting difficulties. If they are abundant they may need to be estimated separately. In this work a counting method for these organisms is show. The main goal is to improve chlorination of activated sludge suffering bulking or foaming through a quantitative record of filamentous bacteria. (Author) 12 refs.

  1. Determination of the TLD-100 physical parameters; Determinacion de parametros fisicos del TLD-100

    Energy Technology Data Exchange (ETDEWEB)

    Paucar J, J.; Picon C, C. [Instituto Nacional de Enfermedades Neoplasicas. INEN. Av. Angamos Este 2520, Lima 34 (Peru)

    1998-12-31

    This study was realized in the Physics service at the Radiotherapy Department of the National Institute of Neoplasic Diseases in Lima, Peru, it was determined the activation energy, the kinetic order and the frequency factor of the fifth peak of the TLD-100 thermoluminescent spectra using different algorithms. This was carried out in parallel with the implementation and design of a software and an interface associated with the Tl lecturer which allows a semiautomatic control for a thermoluminescent lecturer process. (Author)

  2. Determinaciones cuantitativas de la composición de yogures por tecnología NIRS

    OpenAIRE

    Gago Jansà, Meritxell

    2011-01-01

    El presente Trabajo Fin de Máster versa sobre la tecnología NIRS y su utilidad en la determinación de los principales constituyentes químicos del yogur; es decir, proteínas, grasas, hidratos de carbono, minerales y vitaminas. Este trabajo consta de dos partes bien diferenciadas: - La primera parte es teórica y se expone un acercamiento a la espectroscopia NIR con las aplicaciones que ha tenido en la industria alimentaria, en concreto en los derivados lácteos y sobre todo en el yogur. ...

  3. Determination of Tc-99 in radioactive wastes; Determinacion de Tc-99 en desechos radiactivos

    Energy Technology Data Exchange (ETDEWEB)

    Rivera S, A. A.

    2015-07-01

    Tc-99 is a fission product and one of the most important radionuclides from the view point of safety assessment for the disposal of radioactive waste because of its long half-life (2.1 x 10{sup 5} years) and high mobility in soil-water systems, if this is released into the environment in significant quantities can concentrate on plants and animals. Tc-99 is a pure beta emitter with a maximum energy of 292 KeV, so their quantification imposes destructive methods to be analyzed by liquid scintillation. Therefore the quantification of Tc-99 in ion exchange resins requires of the mineralization of these and separation of Tc-99 of other radioisotopes present in the resin. Therefore the object of this thesis is to develop a quantification method of Tc-99 content in spent exchange resins. So in order to track the behavior of technetium during digestion exchange resins and radiochemical separation, given its high volatility, in this work the {sup 99m}Tc is used. To determine the degree of mineralization of the resins, an analysis was performed by chromatography. Subsequently the method used to determine the percentage of {sup 99m}Tc aerosolized during mineralization of resin is described. After the method for the radiochemical separation of {sup 99m}Tc is presented by liquid-liquid extraction using crown ether as extractant; for this testing was performed by varying the molarity of the extractant, the ratio of solvent extractant, type of digestion of the resin and the presence of Sr-85, in order to study the behavior of {sup 99m}Tc in the presence of this radioisotope. Finally, a track beta spectra of a sample of {sup 99m}Tc eluted from a generator {sup 99}Mo/{sup 99m}Tc function of time was performed. (Author)

  4. Determination of palladium by flame photometry; Determinacion de paladio por fotometria de llama

    Energy Technology Data Exchange (ETDEWEB)

    Parallada Bellod, R.

    1964-07-01

    A study on the determination of palladium by lame photometry, fixing the most convent experimental conditions and using solvents to increase the emission of this elements is carried out. Among the organic solvents, acetone has been found the most efficient. The interferences produced by anions and cations have also been studied and an analytical method is related, in which lines of calibration of 0 to 100 ppm palladium re used. (Author) 7 refs.

  5. Determination of cyanobacteria toxins (microcystins): current situation; Problematica y situacion actual de la determinacion de toxinas de cianobacterias: microcistinas

    Energy Technology Data Exchange (ETDEWEB)

    Moreno Navarro, I. M.; Pichardo Sanchez, S.; Carmean Fernandez, A. M. [Universidad de Sevilla (Spain)

    2003-07-01

    A review of the different biological and chemical methods developed to determine cyano bacterial toxins, microcystins (MC), in freshwater has been carried out. However, any of them have been accepted as a standard method by the official environmental agencies. Biological methods as the mouse bioassays, immunoassays or protein phosphatase, inhibition assays are used as screening methods to detect MC. Analytical methods as High Performance Liquid Chromatography (HPLC) or Capillary Electrophoresis (CE), with different detectors, allow to identify and quantify the individual toxins produced by different cyano bacterial species. (Author) 40 refs.

  6. Quantitative spectrographic determination of traces of germanium in lignite; Determinacion Espectrografica Cuantitativa de trazas de Germanio en Lignitos

    Energy Technology Data Exchange (ETDEWEB)

    Martin, M.; Roca, M.

    1972-07-01

    A burning technique in a d.c. arc at 10 amp has been employed. The standards have been prepared from a natural lignite with a low germanium content. In order to enhance sensitivity, AgCl, K{sub 2}SO{sub 4}, CuF{sub 2}, Sb{sub 2}S{sub 3} and Bi{sub 2}S{sub 3} have been tested as sweeping materials. Using 2% CuF{sub 2} a detection limit of 1 ppm germanium is attainable. Bi, Cu, Sb and Sn have been studied as internal standards: the former leads to the, highest precision (1 6%). Results show good agreement with those obtained by the addition method. (Author) 6 refs.

  7. Uranium potentiometer determination in inactive atmosphere with ferric sulfate; Determinacion poteniometrica de uranio en atmosfera inerte con sulfato ferrico

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez Cellini, R.; Alonso Lopez, J.

    1956-07-01

    Potentiometric titration of Uranium with (SO{sub 4}){sub 3} Fe{sub 2}, using Cd as reducing agent has been studied; acidity and sensibility of this reaction are fixed. This method yields good results for uranite group, removing previously phosphate by ion exchange with Amberlite IR-120. (Author)

  8. Spectrographic determination of impurities in enriched uranium solutions; Determinacion espectrografica de impurezas en soluciones de uranio enriquecido

    Energy Technology Data Exchange (ETDEWEB)

    Capdevila, C.; Roca, M.

    1980-07-01

    A spectrographic procedure for the determination of trace amounts of Al, B, Ba, Be, Bi, Ca, Cd, Co, Cr, Cu, Fe, K, L i , Hg, Mn, Mo, Na, Nb, Ni, P, Pb, Ru, Sb, Sn, Sr, Ti, V, Zn, and Zr in enriched uranyl nitrate solutions from the reprocessing of spent nuclear fuels is described. After removal of uranium by either TBP or TNOA solvent extraction, the aqueous phase Is analysed by the graphite spark technique. TBP is adequate for all impurities, excepting boron and phosphorus; both of these elements can sat is factory be determined by using TNOA after the addition of mannitol to avoid boron losses. (Author) 4 refs.

  9. Quantitative spectrographic determination of traces of manganese in ferric oxide; Determinacion espectrografica cuantitativa de trazas de manganeso en oxido ferrico

    Energy Technology Data Exchange (ETDEWEB)

    Capdevila, C.; Roca, M.

    1968-07-01

    In order to enhance the sensitivity, different electrode types and sweeping substances have been studied. Graphite anodes, with 5 x 2,5, 4 x 4,5, 4 x 8 and 7 x 10 mm crater, as well as CuF{sub 2}, AgCl, ZnO and graphite powder as sweeping materials, have been tested. A JACO-Ebert grating spectrograph and 10 amp. d.c. arc have been employed, choosing the proper exposure times from moving-plate studies. Using 4 x 4,5 mm electrodes and 75% AgCl a detection limit of 0,2 ppm is attainable. (Author) 7 refs.

  10. Fluorimetric determination of uranium in zirconium and zircaloy alloys; Determinacion fluorimetrica de uranio en aleaciones de zirconio y zircaloy

    Energy Technology Data Exchange (ETDEWEB)

    Acosta L, E. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)]. e-mail: eal@nuclear.inin.mx

    1991-05-15

    The objective of this procedure is to determine microquantities of uranium in zirconium and zircaloy alloys. The report also covers the determination of uranium in zirconium alloys and zircaloy in the range from 0.25 to 20 ppm on 1 g of base sample of radioactive material. These limit its can be variable if the size of the used aliquot one is changed for the final determination of uranium. (Author)

  11. Determination of {sup 60}Co sorption in natural clinoptilolite; Determinacion de la sorcion de {sup 60}Co en clinoptilolita natural

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez B, E.; Granados C, F. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    1997-07-01

    It was studied the clinoptilolite behavior coming from a deposit in Taxco, Guerrero in hydration and stabilization conditions with sodium for determining its sorption properties. The ion exchange process was carried out through gamma spectrometry using a CoCl{sub 2} solution marked with {sup 60} Co at p H 6.5 in different contact times. It was observed a maximum sorption of 0.408 m eq Co{sup +2}/g mineral, from 0.314 m eq Co{sup +2}/g mineral correspond at ion exchange. (Author)

  12. Determination of radon levels in Mexico City; Determinacion de niveles de radon en la Ciudad de Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Pena G, P

    1992-01-15

    The study of the determination of radon levels in the houses room in Mexico City is part of the project Emanometry of the radon. To carry out this study, the passive method was used, which consists of: thin film dosemeter of cellulose nitrate, container of the same one and spark accountant. The method is based on the mensurations of exhibition of the number of marks of alpha track is of the open type and it allows to average the radon activity along several weeks and it presents low concentrations. This study was carried out in 4 periods of exhibition of 3 months each one. (Author)

  13. Spectrographic determination of strontium in yttrium-90 solutions; Determinacion espectrografica de estroncio en soluciones de itrio-90

    Energy Technology Data Exchange (ETDEWEB)

    Roca, M.; Capdevila, C.

    1970-07-01

    The copper spark method has been used for determining strontium in the concentration range 1-100 g/ml in yttrium-90 solutions containing 0,5 % or thereabouts of ammonium citrate. The influence of the citric acid as well as the ammonium citrate with regard to 2N HCL solutions has been studied: the citric acid enhances the line intensities of strontium. The employment of either barium or lanthanum as reference element compensates for this enhancement. Because of the increase in sensitivity mentioned above, the study of influence of the citric acid has been extended and several impurities usually determined in radioisotope solutions have been considered. (Author) 4 refs.

  14. Volatile organic compound (VOC) determination in working atmospheres; Determinacion de compuestos organicos volatiles (VOC) en ambiente laboral

    Energy Technology Data Exchange (ETDEWEB)

    Blass A, Georgina; Panama T, Luz A; Corrales C, Deyanira [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2003-07-01

    The present work describes, in a synthesized way, the implementation and application of procedures based on the normativity related to the subject of the volatile organic compounds (Volatile Organic Compounds VOC), that allow to sample, quantify and evaluate the present contamination in the working atmosphere of a refinery due to the fugitive emissions of VOC and other substances. In accordance with the corresponding normativity, more than 189 organic compounds denominated dangerous air polluting agents (Hazardous Air Pollutants, HAP) can be found in a working atmosphere, but they are the 11 main HAP that can be found in a refinery. In the present article the work made for the sampling and quantification of 5 of the 11 dangerous polluting agents of the air: benzene, toluene, xylene, iso-octane and naphthalene. [Spanish] El presente trabajo describe, de manera sintetizada, la implementacion y aplicacion de procedimientos basados en la normatividad relacionada al tema de los compuestos organicos volatiles (Volatil Organic Compounds, VOC), que permiten muestrear, cuantificar y evaluar la contaminacion presente en el ambiente laboral de una refineria debido a las emisiones fugitivas de VOC y otras sustancias. De acuerdo con la normatividad correspondiente, mas de 189 compuestos organicos denominados contaminantes peligrosos del aire (Hazardous Air Pollutants, HAP), pueden ser encontrados en un ambiente laboral, pero son 11 los principales HAP que pueden ser hallados en una refineria. En el presente articulo se informa el trabajo realizado para el muestreo y cuantificacion de 5 de los 11 contaminantes peligrosos del aire: benceno, tolueno, xileno, iso-octano y naftaleno.

  15. Determinacion del N y P en abonos organicos mediante la tecnica del elemento faltante y un bioensayo microbiano

    Directory of Open Access Journals (Sweden)

    Eduardo Salas

    2001-01-01

    Full Text Available Mediante la tecnica del elemento faltante en ferinvernadero y el uso de un bioensayo microbiano se determin6 la disponibilidad de N y P en 6 sus- greenhoutratos: suelo s6lo 0 en mezcla 9: 1 con diversos abo- nos organicos, a saber: pollinaza (CM, compost (C, bocashi (B, vermicompost (V 0 broza de ca- determife (Br. En ambos bioensayos y para cada sustrato se realiz6 un experimento factorial 2x2 (fertiliza- ci6n con P y N; las combinaciones resultantes fue- ron: +P, +N, +P+N y -P-N (testigo. En el bioensa- yo microbiano se utiliz6 un diseno de bloques al azar con 6 repeticiones y se midi6 el crecimiento microde la biomasa microbiana nativa (BM 2 dias des- pues de aplicar el tratamiento e incubar con gluco- sa. En la prueba de invernadero se utiliz6 un dise- no completamente al azar con 4 repeticiones, se utiliz6 sorgo (Sorghum vulgare como planta indi- cadora. Se midi6 el peso seco de la parte aerea de lasplantas a los 34 dias de la siembra (PS y el con- tenido foliar de nutrimentos. Ambos bioensayos in- sordicaron respuesta del suelo a la aplicaci6n de P y N. La mezcla del suelo con un 10% de CM, CoB mostraron los valores mas altos de BM y PS. La mezcla suelo:CM no respondi6 a ningun tratamien- to qufmico, mientras que en mezcla con el C 0 el B respondi6 a la aplicaci6n de N pero no al P. Con el Vola Br se obtuvo las menores respuestas de las variables y hubo respuesta ala adici6n de P y N. La tecnica del elemento faltante de invernadero

  16. Determinaciones y relaciones de interacción en el triángulo constituido por preguntas, creatividad y aprendizaje

    Directory of Open Access Journals (Sweden)

    Romina Elisondo

    2016-01-01

    Full Text Available El objetivo del ensayo es argumentar teórica y empíricamente acerca de las relaciones entre preguntas, creatividad y aprendizaje; y proponer orientaciones para construir contextos educativos creativos. Iniciamos el escrito presentando planteos teóricos referidos al enfoque problem finding y destacamos la importancia de las preguntas en la evaluación de la creatividad. Para construir las argumentaciones, recuperamos resultados de una investigación reciente titulada Evaluación de la creatividad: análisis de variables alternativas relacionadas con la forma y el contenido de las respuestas en el test CREA. Luego, nos referimos a la creatividad como componente indispensable de los aprendizajes y proponemos una perspectiva educativa en la cual las preguntas son el eje para la construcción de contextos creativos de enseñanza y aprendizaje. Destacamos el papel de las preguntas únicas e inesperadas como estrategias de enseñanza y de aprendizaje. La perspectiva educativa propuesta también reconoce las particularidades de los contextos tecnológicos actuales como espacios propicios para la interrogación. Asimismo, argumentamos acerca de los sustentos cognitivos, metacognitivos y emocionales de las preguntas en contextos educativos. Por último, planteamos consideraciones respecto de las relaciones entre preguntas, creatividad y aprendizajes en contextos mediados tecnológicamente.

  17. Anaerobic digestion of vinasses: determination of biomass; Digestion anaerobia de vinazas de vino: determinacion de la biomasa viable

    Energy Technology Data Exchange (ETDEWEB)

    Solera, R.; Romero, L.; Salles, D.

    2002-07-01

    In this paper, we studied the thermophilic anaerobic treatment of vinasses. The viable bacterial population was quantified by soil medium plating techniques, employing an anaerobic chamber for spreading into plates and subsequent incubation of inoculated plates. This technique has been applied to the measurement of the microbial population contained in both single and tow-stage, laboratory-scale reactors. In the single-stage process the main reaction steps-acidogenesis and methano genesis-take place in the same reactor, while in the two-stage process they take place in separate reactors. (Author) 11 refs.

  18. Determination of {sup 40}K in water samples; Determinacion del {sup 40}K en muestras de agua

    Energy Technology Data Exchange (ETDEWEB)

    Delgado, C. E.; Miranda C, L.; Cuevas J, A. K.; Vega C, H. R., E-mail: rmfranccesco0223@hotmail.com [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico)

    2014-10-15

    The natural water used for human consumption comes from different sources, which may contain suspended solids in varying proportions. In groundwater, the source of suspended solids is related to the dissolution of mineral strata by the waters and leaching of rocks. Also, the radioactivity could concentrate on the bodies of slow-moving water that eventually could present a risk to ecosystems, as well as for the consumer. The water usually contains several natural radionuclides as: tritium, radon, radio, uranium isotopes, etc. The objective of this study was to evaluate the concentration of {sup 40}K in water from different areas of Zacatecas state (Mexico). Four water samples were taken in triplicate from different areas; the {sup 40}K concentration was measured with a spectrum metric system of gamma radiation with NaI (Tl) scintillation detector of 7.62 cm. In the measuring process a standard was prepared using water and KCl analytic grade where the {sup 40}K concentration is 6.25 mol/Lt adding 250 mg/ml of potassium. Also the system was calibrated in energy using 3 point sources of {sup 137}Cs, diameter {sup 22}Na and 7.62 cm of height, using containers Marinelli and {sup 60}Co. In the obtained spectra was observed that the photon of 1.432 MeV that emits the {sup 40}K when decaying is the most important. The highest concentration was of 123 ± 5.2 Bq/lt and the lowest was of 9 ± 0.4 Bq/lt. Under the standards of drinking water, an amount of {sup 40}K deposits an effective dose which contributes to annual dose received by people. (Author)

  19. Determination of degradation conditions of exchange resins containing technetium; Determinacion de condiciones de degradacion de resinas de intercambio conteniendo tecnecio

    Energy Technology Data Exchange (ETDEWEB)

    Rivera S, A.; Monroy G, F.; Quintero P, E., E-mail: aa_1190@hotmail.com [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2014-10-15

    The quantification of Tc-99 in spent exchange resins, coming from nuclear power plants, is indispensable to define their administration. The Tc-99 is a pure beta emitter of 210000 years of half-life, volatile and of a high mobility in water and soil. For this reason, the objective of this work is to establish a digestion method of ionic exchange resins containing technetium that retains more than 95% of this radioisotope. Mineralization tests were carried out of a resin Amberlite IRN-150 by means of an oxidation heat, in acid medium, varying the resin mass, the medium volume, the media type, the temperature and the digestion time. The digested samples were analyzed by gas chromatography to estimate the grade of their degradation. The {sup 99m}Tc was used as tracer to determine the technetium percentage recovered after mineralizing the resin. The digestion process depends on the temperature and the resin mass. At higher temperature better mineralization of samples and to greater resin mass to a constant temperature, less degradation of the resin. The spectra beta of the {sup 99m}Tc and {sup 99}Tc are presented. (Author)

  20. Experimental determination about thermal comfort conditions in buildings; Determinacion experimental de las condiciones de confort termico en edificaciones

    Energy Technology Data Exchange (ETDEWEB)

    Ambriz Garcia, Juan Jose; Garcia Chavez, Jose Roberto; Paredes Rubio, Hernando Romero [Universidad Autonoma Metropolitana (Mexico)]. E-mail: agj@xanum.uam.mx; jgc@correo.azc.uam.mx; hrp@xanum.uam.mx

    2006-04-15

    This paper analyzes the thermal comfort importance in a building. And the influence it exerts on quality of life as well as the efficiency of people work activities. There are comments about some models which better help to estimate the recommended temperature levels. The experimental evaluation results from a Mexico City population sampler are presented. This work was done in a Controlled Environment Laboratory; the obtained outcomes proved the preferences occupants exceed the comfort zone greatest limit accepted in the reference international standards. The meaning of this conclusion is thermal comfort can be reached with higher temperatures and consequently an energy consumption and an environment impact decrease. [Spanish] En este trabajo se analiza la importancia que tiene el confort termico en la calidad de vida de las personas que ocupan una edificacion y en la eficiencia de sus actividades. Se comentan algunos modelos con los cuales se estiman los niveles de temperatura recomendados y se presentan los resultados de una evaluacion experimental realizada en un Laboratorio de Ambiente Controlado con una muestra de la poblacion del Distrito Federal. Los resultados que se obtuvieron demuestran que los ocupantes tienen preferencias que rebasan el limite superior de la zona de confort comunmente aceptada en los estandares internacionales de referencia. Esto quiere decir que el confort puede lograrse con mayores temperaturas, lo que se traduce en menor consumo de energia y menor impacto en el ambiente.

  1. Determination of tin in cassiterite ores by colorimetry of iodometry; Determinacion de Estano en minerales y productos de concentracion

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Hernandez, B.

    1972-07-01

    The analytical methods are described far the determination of tin in cassiterite ores. The gallein-colorimetric method is described for determining small amounts of tin, covering the 0,01-0,5 per cent range. The sample is decomposed by heating with ammonium iodide, and tin is analyzed colorimetrically by means of it s complex with gallein. The final measure may be brought about either visually or spectrophotometrically at 525 nm. (Author)

  2. Determination of carbon in uranium and its compounds; Determinacion de carbono en uranio metal y sus compuestos

    Energy Technology Data Exchange (ETDEWEB)

    Perez-Garcia, M. M.

    1972-07-01

    This paper collects the analytical methods used our laboratories for the determination of carbon in uranium metal, uranate salts and the oxides, fluorides and carbides of uranium. The carbon is usually burned off in a induction or resistance oven under oxygen flow. The CO{sub 2} is collected in barite solution. Where it is backtitrated with potassium biphthalate. (Author)

  3. Determination of mercury in dentists through Neutron activation analysis; Determinacion de mercurio en odontologos mediante Analisis por activacion neutronica

    Energy Technology Data Exchange (ETDEWEB)

    Padilla M, M.A.; Granados C, F. [Instituto Nacional de Investigaciones Nucleares, Departamento de Quimica, A.P. 18-1027, C.P. 11801 Mexico D.F. (Mexico)

    2000-07-01

    It was determined the mercury levels in urine through Neutron activation analysis to 25 dentists who have been exposed to mercury by several time periods, because of the routine manipulations of amalgams. The determined concentrations of mercury were less to 10 {mu} g Hg/l of urine. The results were founded inside the safety limits reported in the literature. The mercury levels in the dentists are associated with a wide variety of factors that contribute to their exposure as: number of years of dental practice, number of amalgams manipulated between others. (Author)

  4. Determination of forces induced by steam flow in turbines; Determinacion de fuerzas inducidas por flujo de vapor en turbinas

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Castrejon, Juan Carlos

    2008-09-15

    The steam flow induced vibrations in turbines is a common problem during the operation of 300 MW turbines and it is one of the problems that requires solution to develop 1 GW steam turbines. The flow induced vibration is caused because there is an interaction between blades and the flow field. Blades are subjected to the forces caused by the flow field, but also the flow field is affected by the blades and its movement. The nozzle wakes cause uneven pressure field downstream and produces alternating forces on blades which lead to blade vibrations. Some of the vibrations originated in this way may damage the blades and affect the turbine performance. The forces acting on blades (and causing forced vibrations) as a result of the variations in the flow field in the axial rotor-stator clearance are studied in this project. These forces were determined applying computer fluid dynamics (CFD) in two turbine stages. The CFD analysis was carried out in the Curtis stage and in the last stage, using 2D and 3D models. An important part of the analysis is focused on discussing the pressure field variation, because this variation caused the forces acting on blades. The flow field was resolved using CFD and the computed pressure field was integrated around the blades to get the forces acting on blades. These computed dynamical forces were analyzed using a FFT analysis and the results were used in the blade useful life estimation and in the investigation of the failure causes of these blades. In every turbine stage the RNG - turbulence model and the sliding mesh method was used to deal with the blade motion. The 3D models were resolved using parallel computation in a cluster of 6 AMD 64 Opteron processors of 2412.36 MHz and 8 Gb of RAM. The results of the simulation in both stages get the pressure field behavior in the axial rotor-stator clearance and determine the force acting on the blades. These results showed that both, the pressure field and the force magnitude acting on blades, has a harmonic pattern. The pressure field variation as time function is uniform: the peaks and valleys across the axial clearance are always in phase. However the instant picture of the pressure field it's different: the peaks and valleys are not in phase and the number of peaks and valley changed across the clearance. In the case of the forces acting on blades, a Fourier on the forces calculated was used to determine the coefficients and frequency of a Fourier equation which can be used to calculate the alternating stresses on the blade in order to predict the useful life blades. [Spanish] Las vibraciones inducidas por flujo de vapor en turbinas representan uno de los problemas que enfrenta la operacion de turbinas de vapor cuya capacidad rebasa los 300 MW. Ademas estas constituyen uno de los limites tecnologicos para el desarrollo de turbinas de vapor de mas de 1 GW. Este tipo de fenomeno tiene su origen en la interaccion del rotor con el fluido que se encuentra en sus proximidades. El flujo de vapor dentro de la turbina es complejo, ya que es turbulento e inestable. A medida que el flujo pasa una etapa de estator o de rotor, se generan secundarios, vortices en los filos de salida, estelas con caracteristicas de flujo diferentes al flujo principal en los pasajes. Estas variaciones en el flujo son las que inducen vibraciones forzadas en los alabes. Ademas existen varios factores que contribuyen a la aplicacion de vibraciones en alabes inducidas por flujo como son: inestabilidad del flujo de vapor en los claros de los sellos, secuencia de apertura de las valvulas, estelas de las toberas, obstrucciones en algunas de las toberas y diferente espaciamiento en las toberas. Las vibraciones por flujo pueden ser peligrosas si su frecuencia coincide con la frecuencia natural del sistema, provocando efectos mas nocivos que las vibraciones por desbalance o por desalineamiento, pues tienen amplitudes mas grandes y provocan esfuerzos alternantes en los componentes del rotor, lo que lleva a fracturas de los componentes por fatiga. Este trabajo estudia y calcula las fuerzas de excitacion de las vibraciones inducidas por flujo. Se realiza el analisis del flujo, en dos etapas diafragma-rotor de una turbina de vapor, con base en el Modelado Computacional de Dinamica de Fluidos (MCDF). Las etapas de la turbina bajo estudio son la primera etapa o paso Curtis y la ultima etapa o etapa de baja presion de la Turbina. El paso Curtis esta formado por alabes pequenos y el flujo esta sometido a altas presiones. El ultimo paso esta compuesto por alabes grandes y el flujo esta sometido a bajas presiones. El MCDF resuelve numericamente las ecuaciones que representan la dinamica de fluidos y se obtiene la variacion del campo de presion en el claro axial rotor-estator causada por la interaccion de las estelas del borde de salida de los diafragmas con el movimiento de los alabes. La variacion del campo de presion induce fuerzas en los alabes ocasionando vibraciones forzadas. En cada una de las etapas se realizaron simulaciones en 2D y 3D, que se resolvieron en funcion del tiempo, usando el modelo de turbulencia RNG - y la tecnica de malla deslizante, para simular el movimiento de los alabes. Los modelos en 3D se resolvieron usando computo en paralelo en un cluster compuesto por 6 procesadores AMD Optaron e 64 bits, 2412.36 MHz y 8Gb de memoria RAM. Los resultados de las simulaciones en las dos etapas, permitieron obtener el comportamiento del campo de presion en el claro axial tobera-rotor y las fuerzas que este campo induce sobre los alabes. La fuerza sobre los alabes fue calculada usando un codigo que se ejecutaba en cada paso temporal de la simulacion, esta fuerza fue posteriormente analizada usando la transformada rapida de Fourier para obtener la fuerza sobre los alabes como una expresion matematica. Usar el MCDF para obtener las fuerzas que actuan sobre los alabes y que son inducidas por flujo representa una ventaja sobre otros metodos de calculo que usan geometrias simplificadas en 2D y caracteristicas de flujo promedio, y no toman en cuenta la geometria real de las turbinas ni consideran que el flujo sea no homogeneo. Ademas con el MCDF se obtiene que las fuerzas inducidas son ondulatorias (cambian en su magnitud con respecto al tiempo), otros metodos de calculo solo muestran una fuerza constante en el tiempo. Finalmente el estudio de la presion en el claro axial tobera-rotor mostro que cuando los alabes estan en movimiento, el campo de flujo para una region dada del claro es completamente ondulatorio con sus picos o valles en fase. Cambiando solo la amplitud de las ondas. Pero instantaneamente el campo de presion tienen una forma diferente alturas, asi como tambien el numero de picos y valles en cada perfil cambia en el sentido del claro.

  5. Determinacion del error sistematico del momentum de muones producidos por interacciones neutrino-nucleon en el detector MINER$\

    Energy Technology Data Exchange (ETDEWEB)

    Diaz Bautista, Gonzalo A. [Pontifical Catholic Univ. of Peru, Lima (Peru)

    2015-11-29

    El Modelo Estandar describe todas las partculas observadas en el naturaleza hasta el momento as como las caractersticas que gobiernan a las interacciones fundamentales entre ellas. En especial es posible identicar a las interacciones electromagnetica y debil, las cuales bajo determinadas condiciones de temperatura y energa pueden ser descritas a traves de una sola teora que engloba a ambas. A esta teora se le denomina electrodebil y tiene como nalidad caracterizar las propiedades de la interaccion maniesta a partir de la mezcla de las interacciones electromagnetica y debil, la que tambien lleva como nombre interaccion electrodebil. Particularmente, los neutrinos son de especial interes ya que, por un lado, interactuan por medio de la interaccion debil muy raramente en comparacion con otras partculas y, por el otro, no son acertadamente descritos por el Modelo Estandar. Por medio de observaciones experimentales que demostraban que los neutrinos cambian de sabor al propagarse, fenomeno llamado oscilaciones de neutrinos, se pudo llegar a la conclusion de que la implicancia de este fenomeno da como consecuencia que los neutrinos efectivamente s tienen masa, algo que entra en contradiccion con la descripcion inicial del Modelo Estandar, el cual los describe como partculas sin masa. Es de esta manera que las oscilaciones de neutrinos han sido y siguen siendo en la actualidad objeto de interes en la Fsica de Altas Energas tanto teorica como experimental. A n de poder realizar mediciones precisas de oscilaciones de neutrinos, los experimentos encargados de estas mediciones deben tratar de reducir sus incertidumbres en lo posible. Una de estas proviene de la caracterizacion de las secciones de choque de los neutrinos cuando interactuan con la materia, particularmente los nucleones al interior de los nucleos atomicos. El experimento MINERA esta orientado, entre otras cosas, a hacer una correcta caracterizacion de secciones de choque neutrino-nucleon por medio del estudio de un tipo especco de interaccion denominado corriente cargada, cuyas partculas de estado nal incluye hadrones y, principalmente, muones. La precision en los resultados de secciones de choque esta sujeta a que la energa y el momentum estos muones sean, a su vez, correctamente caracterizados, incluyendo sus incertidumbres sistematicas. El objetivo de este trabajo de tesis es precisamente presentar la metodologa usada para medir las energas de los muones producidos por interacciones de neutrinos y sus correspondientes incertidumbres asociadas a dicha medicion.

  6. Photostability Assessment in Amorphous-Silicon Solar Cells; Determinacion de la Fotoestabilidad en Celulas Solares de Silicio Amorfo

    Energy Technology Data Exchange (ETDEWEB)

    Gandia, J. J.; Carabe, J.; Fabero, F.; Jimenez, R.; Rivero, J. M. [Ciemat, Madrid (Spain)

    2000-07-01

    The present status of amorphous-silicon-solar-cell research and development at CIEMAT requires the possibility to characterise the devices prepared from the point of view of their stability against sunlight exposure. Therefore a set of tools providing such a capacity has been developed. Together with an introduction to photovoltaic applications of amorphous silicon and to the photodegradation problem, the present work describes the process of setting up these tools. An indoor controlled-photodegradation facility has been designed and built, and a procedure has been developed for the measurement of J-V characteristics in well established conditions. This method is suitable for a kinds of solar cells, even for those for which no model is still available. The photodegradation and characterisation of some cells has allowed to validate both the new testing facility and method. (Author) 14 refs.

  7. Determination of thermal neutrons diffusion length in graphite; Determinacion de la Longitud de Difusion de los Neutrones Termicos en Grafito

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Fite, J.

    1959-07-01

    The diffusion length of thermal neutrons in graphite using the less possible quantity of material has been determined. The proceeding used was the measurement in a graphite pile which has a punctual source of rapid neutrons inside surrounded by a reflector medium (paraffin or water). The measurement was done in the following conditions: a) introducing an aluminium plate between both materials. b) Introducing a cadmium plate between both materials. (Author) 91 refs.

  8. Element determination of fine particles in environmental aerosols using PIXE; Determinacion elemental de paticulas finas en aerosoles ambientales usando PIXE

    Energy Technology Data Exchange (ETDEWEB)

    Garcia O, B. [ITT, 50000 Toluca (Mexico); Aldape U, F. [ININ, 52750 La Marquesa, Estado de Mexico (Mexico)]. e-mail: gaolivab@gmail.com

    2007-07-01

    The Mexico city is classified as one of the more populated cities of the world which presents a decrease in the air quality and that gives place to a severe problematic in atmospheric pollution. To cooperate in the solution of this problem it is necessary to carry out studies that allow a better knowledge of the atmosphere of the city. This study presents the results of a monitoring campaign of fine particle carried out from September 21 to December 12, 2001 in three sites of the Mexico City center area. The samples were collected every third day with a collector type unit of heaped filters (Gent). The analysis of these samples was carried out in the 2 MV accelerator of the National Institute of Nuclear Research (ININ) applying the PIXE technique and with this analysis its were identified in the samples approximately 15 elements in each one of the 3 sites and was calculated the concentration in that its were present. With these results a database was created and by means of it mathematical treatment the Enrichment factor (FE), the time series of each element and the multiple correlation matrix were evaluated. The obtained results showed that the Civil Registration site (Salto del Agua) it was the more polluted coinciding that to a bigger concentration of activities a bigger increase in the pollution is generated. (Author)

  9. DETERMINACION DE FACTORES DE RIESGO DE MOBBING EN LAS EMPRESAS ESTATALES DE LA PROVINCIA DE SANTA ELENA

    Directory of Open Access Journals (Sweden)

    Bertha Maggi De Monserrate

    2016-04-01

    Full Text Available El Mobbing es una patalogía considerada por la Organizacion Mundial de la Salud y la Organizacion Panamericana como una entidad clinica muy violenta que en los ultimos dias ha tomado un auge considerable afectando el desarrollo de las naciones y constituyendo una amenaza para la salud publica a nivel mundial. Este término proviene del vocablo anglosajón que se traduce como acoso moral, psicoterror laboral, violencia psicológica, en resumen una medida de conducta agresiva hacia el trabajador victima, por parte de otro trabajador agresor. Los especialistas coinciden en que se trata de un problema de salud publica, alcanzando el grado de epidemia - pandemia. El objetivo de proyecto es determinar los factores de riesgo que inducen al Mobbing en los trabajadores de los Establecimientos Estatales de la Provincia de Santa Elena, en una muestra al azar de 400 trabajadores. El instrumento de Recoleccion de datos será el Inventario de Acoso Moral de Leyman. El resultado será diagnostico de Mobbing en los trabajadorobjeto de estudio para la intervención psicológica respectiva.

  10. Plutonium determination in urine by techniques of mass spectrometry; Determinacion de plutonio en orina por tecnicas de espectrometria de masas

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez M, H. [ININ, Departamento de Quimica, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Yllera de Ll, A., E-mail: hector.hernandez520@gmail.com [Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas, Departamento de Medio Ambiente, Av. Complutense 22, 28040 Madrid (Spain)

    2013-10-15

    The objective of this study was to develop an analytic method for quantification and plutonium reappraisal in plane tables of alpha spectrometry be means of the mass spectrometry technique of high resolution with plasma source inductively coupled and desolvator Aridus (Aridus-Hr-Icp-Ms) and mass spectrometry with accelerator (AMS). The obtained results were, the recovery percentage of Pu in the plane table was of ∼ 90% and activity minimum detectable obtained with Aridus-Hr-Icp-Ms and AMS was of ∼ 3 and ∼ 0.4 f g of {sup 239}Pu, respectively. Conclusion, the results demonstrate the aptitude of the Aridus-Hr-Icp-Ms and AMS techniques in the Pu reappraisal in plane tables with bigger speed and precision, improving the values notably of the activity minimum detectable that can be obtained with the alpha spectrometry (∼ 50 f g of {sup 239}Pu). (author)

  11. Determination of some heavy metals in wetlands by PIXE; Determinacion de algunos metales pesados en jales por medio de PIXE

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez O, J.; Rios M, C. [UAZ, 98160 Zacatecas (Mexico)

    2008-07-01

    In this work the results of the analysis are presented, using the PIXE technique (Proton Induced X-ray Emission), in soil samples of the El Bordo, Vetagrande, Zacatecas, before and after subjecting them to a lixiviation process for the recovering of gold, silver and mercury. This community is part of the mining region nearer to the Zacatecas city municipality, region in which the mining exploitation dates from the colonial time. During almost 350 years the 'yard benefit' method was used or amalgamation with mercury, process that besides having used big quantities of mercury, generated a great quantity of mineral waste calls 'mine wetlands', those that were accumulating, crawled by the rains, toward the streams that end in the prey 'The Pedernalillo'. The dispersion of wetlands them it has extended from the prey until the communities of Tacoaleche, Zoquite, Lampotal and El Bordo, embracing an approximate area of 16 x 2 Km{sup 2} and forming with the course of the time an accumulated of several millions of tons. In order to determining if the process of recovery of gold, silver and mercury make soluble to other contained metals in these wastes, samples were gathered in an area of 600 m{sup 2} in the community of The Border, Vetagrande, Zacatecas. Half of the samples were subjected to the lixiviation process in a local metal recovery plant and the other part was analyzed without processing. The analysis of both types of samples by means of the PIXE was carried out in the University of Arizona in Tucson. (Author)

  12. Determinants of labor safety management in Spanish companies; Determinacion de la gestion de la seguridad laboral en las empresas espanolas

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez Muniz, B.; Montes Peon, J. M.; Vazquez Ordas, C. J.

    2011-07-01

    Managing health and safety risks in an integrated way with the operations of the organization has been of increasing importance in recent years. This approach reduces accident rates, reducing losses and improves the firm's productivity. However, very little attention has been paid to analyse the organizational factors that favour or limit the implementation of the safety management system in firms. In an attempt to address this gap in the literature, the present study focuses on the identification of the characteristics of the organization that encourage the development of this system. The results show that several factors, as firm's size, previous experience on quality and environmental management or internationalisation, among others, have a positive influence on safety management system. (Author) 62 refs.

  13. FIA versatile system for spectrophotometric determinations of vanadium and molybdenum exploring the catalytic activities of V(V) and Mo(VI); Sistema FIA polivalente para determinacoes espectrofotometricas de vanadio e molibdenio explorando as atividades cataliticas de V(V) e Mo(VI)

    Energy Technology Data Exchange (ETDEWEB)

    Luca, Gilmara Caseri de

    1996-02-01

    A versatile system for chemical analysis by flow injection analysis was developed and applied for catalytic spectrophotometric determination of vanadium or molybdenum in metallic alloys. The selected methods were based upon indicator reactions chromotropic (CS)-bromate acid or hydrogen iodide-peroxide, respectively. Initially, a model system was proposed, in which common parameters for methods were studied. This included a re-sampling process in which high degrees of samples dilution were obtained. Other parameters such as concentrations and reagents addition order, reaction medium Ph, temperature and ionic power, as well as procedures for sample solubilization, were studied relating to each method. A mini-column with cationic exchanger resin (Dowex 50W-X8, 50-100 mesh, H{sup +} form) was used. The system for vanadium determination processes 120 samples by hour, consuming 2,0 mg CS and 10 mg K Br O{sub 3b}y determination. Concerning the method for molybdenum, the reagents consumption was 2,0 mg KI and 1,0 {mu}L of solution 30% H{sub 2}O{sub 2} by determination, since the analytic velocity was the same, in relation to vanadium.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1994-07-01

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

  15. 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)

  16. PREPARACION Y DETERMINACION DE LA CONFIGURACION ABSOLUTA DE DERIVADOS DEL (3R,6R)- Y (6S,6S)-3alfa, 6beta-TROPANODIOL

    OpenAIRE

    MUÑOZ FLORES, MARCELO ANDRES; MUÑOZ FLORES, MARCELO ANDRES

    2008-01-01

    Los alcaloides del tropano son un grupo definido de productos naturales que tienen en común el esqueleto base 8-metil-8-azabiciclo[3.2.1]octano. Hasta ahora se conocen más de 200 de estos alcaloides, la mayoría pertenecientes a las familias botánicas de las Solanáceas, Eritroxiláceas y Convolvuláceas. Estas moléculas presentan variados usos farmacológicos, la mayoría de éstos relacionados a su capacidad de bloquear los sitios activos de los receptores colinérgicos muscarínicos. La (-)-e...

  17. Development of Methodologies from Determination of Organic Components from Atmospheric Aerosol; Desarrollo de Metodologias para la Determinacion de Componentes Organicos del Aerosol Atmosferico

    Energy Technology Data Exchange (ETDEWEB)

    Pindado, O.; Perez, R.; Garcia, R.; Barrado, A. I.; Sevillano, M. L.; Gonzalez, D.

    2006-07-01

    It is presented method for the organic compound determination, such as n-alkanes, PAH's, alcohols and fatty acids that are comprised the particulate matter of aerosol. The procedure is based on sampling the particulate matter over quartz fibre filters that will be extracted by means of the Soxhiet technique, and later they will be divided by means of silicagel column. PAH's is analyzed by means of HPLCm whereas the rest is analyzed by GC-MS and for it, acids and alcohol must be previously derivatized with BSTFA.12 samples took shelter of fractions PMIO and PM2.5 of the aerosol of country side like application of the method. (Author) 60 refs.

  18. APLICACIÓN DE LA HERRAMIENTA FRAX® PARA LA DETERMINACION DEL RIESGO DE FRACTURA EN MUJERES DE UN ÁMBITO RURAL

    Directory of Open Access Journals (Sweden)

    Rafael Gómez Navarro

    2010-01-01

    Resultados: El número final de mujeres estudiadas fue 76, su edad media 67,9 ± 13,4. El riesgo absoluto de fractura osteoporótica fue del 8,1 ± 7,9 y el riesgo de fractura de cadera del 3,7 ± 5,3. Se recomendó solicitar DEXA en 9 (11,8% y plantear el inicio de tratamiento en 3 (3,9%. Para 9 mujeres (>84 años, la Guía no establecía recomendaciones. El número necesario de mujeres a cribar para indicar la realización de una DEXA es 8,4 y de 25,3 para iniciar un tratamiento. Se inició en los 3 casos recomendados y en otra mujer más para la que la Guía no emitía recomendación. Conclusiones: La herramienta FRAX® nos ha facilitado determinar de una manera sencilla el riesgo absoluto de fractura osteoporótica y de cadera de las mujeres de nuestra población lo que nos ha ayudado a decidir iniciar tratamiento antirresortivo casi en el 4 % de las estudiadas.

  19. Determination of leveled costs of electric generation for gas plants, coal and nuclear; Determinacion de costos nivelados de generacion electrica para plantas de gas, carbon y nucleares

    Energy Technology Data Exchange (ETDEWEB)

    Alonso V, G.; Palacios H, J.C.; Ramirez S, J.R.; Gomez, A. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)]. e-mail: galonso@nuclear.inin.mx

    2005-07-01

    The present work analyzes the leveled costs of electric generation for different types of nuclear reactors known as Generation III, these costs are compared with the leveled costs of electric generation of plants with the help of natural gas and coal. In the study several discount rates were used to determine their impact in the initial investment. The obtained results are comparable with similar studies and they show that it has more than enough the base of the leveled cost the nuclear option it is quite competitive in Mexico. Also in this study it is also thinks about the economic viability of a new nuclear power station in Mexico. (Author)

  20. Development of an analytic method for arsenic's determination in lime and tortilla; Desarrollo de un metodo analitico para determinacion de arsenico en cal y tortilla

    Energy Technology Data Exchange (ETDEWEB)

    Huato Soberanis, Julio; Ogura, Tetsuya [Universidad Autonoma de Guadalajara, Guadalajara, Jalisco (Mexico)

    1995-02-01

    A spectrophotometric method to determine As in tortilla and lime has been optimized, modifying the AsH{sub 3} generator. The reaction between arsin (AsH{sub 3}){sub 4} and diethyldithiocarbamate of Ag (AgDDC); was followed spectrophotometrically. The conditions under which the As remains in the ash during the calcination of the tortillas were studied. It was found that when they were heated in a quartz tube with a careful control of the air flow and oxygen, as well as the heating temperature, the arsenic loss in minimized. [Spanish] Se ha optimizado el metodo para determinar As en la tortilla y cal mediante espectrometria en el visible del color producido en la reaccion entre Arsina (AsH{sub 3}){sub 4} y dietilditiocarbamato de plata (AgDDC); modificando el generador de AsH{sub 3}. Se han buscado las condiciones en las que el arsenico permanece en las cenizas de la calcinacion de las tortillas; encontrandose que las tortillas deben calentarse en un tubo de cuarzo con control del flujo de aire y oxigeno asi como de la temperatura de calentamiento.

  1. Determination of the degradation constant and endogenous constant and endogenous respiration using a respirometric technique. Determinacion de la constante de degradacion y respiracion endogena mediante una tecnica respirometrica

    Energy Technology Data Exchange (ETDEWEB)

    Menendez Gutierrez, C.; Perez Olmo, J.

    1993-08-01

    Using the common basic equation for expressing the activated sludge process, it was established that where the sludge is more than 5 days old, employing the total biomass descomposition speed coefficient (kb) may lead to EDAR design errors. It should be replaced by the coefficient for the degradable biomass (kj) which is relatively quick and easy to determine. (Author) 5 refs.

  2. Development of a methodology for the determination of radionuclides by Icp-SFMS; Desarrollo de una metodologia para la determinacion de radionuclidos en aerosoles por ICP-SFMS

    Energy Technology Data Exchange (ETDEWEB)

    Mendez G, C. G.; Romero G, E. T.; Hernandez M, H. [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Solis R, C.; Chavez L, E. R., E-mail: griselmendez@fisica.unam.mx [UNAM, Instituto de Fisica, Ciudad Universitaria, 04510 Ciudad de Mexico (Mexico)

    2016-09-15

    A methodology was established for the determination of {sup 75}As, {sup 202}Hg, {sup 208}Pb, {sup 60}Ni, {sup 232}Th, {sup 234}U, {sup 235}U, {sup 238}U, by magnetic field inductive coupling mass spectrometry (Icp-SFMS) of various samples at the National Laboratory of Nuclear Forensic Research of the Instituto Nacional de Investigaciones Nucleares (ININ) in order to determine radionuclides in aerosol samples. The concentrations calculation of {sup 75}As, {sup 202}Hg, {sup 208}Pb and {sup 60}Ni allowed to validate the reliability of the proposed methodology when comparing the concentrations obtained with the application of the same and the concentrations of the same elements reported for the Certified Reference Material (CRM) of particulate atmospheric material of an urban area (Nist 1648-a), the comparison showed that the proposed methodology is feasible for the determination of not only radionuclides, but also for these trace elements. Detection and quantification limits of the order of microns of ng L{sup -1} were reached, corroborating with this the acceptance of the proposed methodology. Concentrations of the radionuclides of interest for CRM could be calculated. The concentrations of the radionuclides found in white samples and of the reagents used in the processing of the aerosol filters indicated that the calculations found belong to or correspond to the calculations that are reflected in the background measurement. Concentrations of {sup 232}Th, {sup 234}U, {sup 235}U and {sup 238}U in aerosols of the Cuernavaca City, Morelos (Mexico) showed higher values than those established by the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR), however the concentration of the radioisotopes per unit volume are within the typical values reported for the northern hemisphere; the value of isotopic ratios greater than unity point to the influence of anthropogenic activities or environmental factors such as the direction of the wind or the imbalance of these radionuclides in the atmosphere. (Author)

  3. Determination of the response of a NaI(Tl) detector; Determinacion de la respuesta de un detector de NaI(Tl)

    Energy Technology Data Exchange (ETDEWEB)

    Vega C, H.R.; Manzanares A, E.; Hernandez D, V.M.; Chacon R, A. [Universidad Autonoma de Zacatecas, A.P. 336, 98000 Zacatecas (Mexico)]. e-mail: fermineutron@yahoo.com

    2006-07-01

    By means of Monte Carlo calculations it was determined the response of a scintillator of NaI (Tl) of 7.62 {phi} x 7.62 cm to monoenergetic gamma rays of 0.2 to 3.5 MeV. The response allows to determine the spectra of height of pulses of the monoenergetic photons. This type of calculations was also carried out for photons emitted by sources of Cs-137, Co-60, Na-22, Na-24 and {sup 239} PuBe, with the purpose of reproducing the gamma spectra obtained with this type of detecting. In the calculations the detector was modelled as a NaI cylinder with Al cover and the base of lucite; due to the absence of reliable information on the quantity of thallium in the calculations this information was omitted: for photons whose energy is greater to 1.022 MeV the presence of the gamma peak of the simple escape and twice is observed. The source was modelled as punctual and was located to 5 cm along the axial axis of the detector. To verify the calculations its were carried out measurements with a spectrometer with a scintillator of 7.62 {phi} x 7.62 cm. In the measured spectra the sum peak is observed, while in those calculated it doesn't appear; because the simultaneous detection of photons of different energy doesn't happen each photon since, in single form, it is followed until its complete absorption in the scintillator or when it escapes from the volume of the detector. To reproduce the sum peak and to obtain height spectra of pulses similar to those measured, the sum photons were introduced in the calculations. With the purpose of that Monte Carlo calculation it reproduces the scattering around the photopeak it was used a gaussian function in each photopeak whose characteristics were obtained starting from the experimental data. The calculation of the response of a scintillator allows to establish the capacity of the measurement of the gamma radiation as well as to distinguish the real events of those that appear by the limitations of the detection process. (Author)

  4. An Optimised Method to Determine PAHs in a Contaminated Soil; Metodo Optimizado para la Determinacion de PAHs en un Suelo Contaminado

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Alonso, S.; Perez Pastor, R. M.; Sevillano castano, M. L.; Escolano Segovia, O.; Garcia Frutos, F. J.

    2007-07-20

    An analytical study is presented based on an optimised method to determine selected polycyclic aromatic hydrocarbons (PAHs) by High Performance Liquid Chromatography (HPLC) with fluorescence detection. The work was focused to obtain reliable measurements of PAH in a gas work contaminated soil and was performed in the frame of the project 'Assessment of natural remediation technologies for PAHs in contaminated soils' (Spanish Plan Nacional l+D+i, CTM 2004-05832-CO2-01): First assays were focused to evaluate an initial proposed procedure by sonication extraction in the contaminated soil. Afterwards to extend the efficiency and reduce solvent and time consuming of extraction procedures, the more relevant parameters that affect the extraction step were investigated. A comparison between sonication and microwave procedures was done, and the influence of sample grinding was studied. In general, both extraction techniques led on comparable results, although sonication procedure needs to be more carefully optimised. Finally, as a final application of the optimised method, the effect of particle size on relative distribution of selected PAHs in the contaminated soil was investigated. Relative abundance of more volatile PAHs showed a decreasing according to lower grain size, while relative abundance of less volatile compounds indicated an increasing of concentration levels for lower grain size. (Author) 10 refs.

  5. Determination of isodose curves in Radiotherapy using an Alanine/ESR dosemeter; Determinacion de curvas de isodosis en Radioterapia usando un dosimetro de Alanina/ESR

    Energy Technology Data Exchange (ETDEWEB)

    Chen, F.; Baffa, O.; Graeff, C.F.O. [Departamento de Fisica e Matematica. Universidade de Sao Paulo FFCLRP. 14040-901 Ribeirao Preto-SP (Brazil)

    1998-12-31

    It was studied the possible use of an Alanine/ESR dosemeter in the isodose curves mapping in normal treatments of Radiotherapy. It was manufactured a lot of 150 dosemeters with base in a mixture of D-L Alanine dust (80 %) and paraffin (20 %). Each dosemeter has 4.7 mm diameter and 12 mm length. A group of 100 dosemeters of the lot were arranged inside 50 holes of the slice 25 of the phantom Rando Man. The phantom irradiation was realized in two opposed projections (AP and PA) in Co-60 equipment. A group of 15 dosemeters was take of the same lot for obtaining the calibration curve in a 1-20 Gy range. After irradiation the signal of each dosemeter was measured in an ESR spectrometer operating in the X-band ({approx} 9.5 GHz) and the wideness of Alanine ESR spectra central line was correlated with the radiation dose. The wideness dose calibration curve resulted linear with a correlation coefficient 0.9996. The isodose curves obtained show a profile enough similar at comparing with the theoretical curves. (Author)

  6. Electron density and temperature determination in a Tokamak plasma using light scattering; Determinacion de la densidad y temperatura electronicas en un Tokamak mediante difusion luminosa

    Energy Technology Data Exchange (ETDEWEB)

    Perez-Navarro Gomerz, A.; Zurro Hernandez, B.

    1976-07-01

    A theoretical foundation review for light scattering by plasmas is presented. Furthermore, we have included a review of the experimental methods for electron density and temperature measurements, with spatial and time resolution, in a Tokamak plasma using spectral analysis of the scattered radiation. (Author) 13 refs.

  7. Simultaneous determination of Cr, Ni and V in urine by electrothermal atomic absorption spectrometry (ET AAS); Determinacion simultanea de Cr, Ni y V en orina mediante et aas

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez, Maria A.; Hermida, Jeymi [Universidad Central de Venezuela, Caracas (Venezuela, Bolivarian Republic of). Escuela de Quimica. Centro de Quimica Analitica

    2011-07-01

    A procedure for the simultaneous determination of Cr, Ni, and V in urine by electrothermal atomic absorption spectrometry (ET AAS) was optimized by factorial design, and performed at a pyrolysis and atomization temperatures of 1300 and 2500 deg C, respectively, using 15 {mu}g de Mg(NO{sub 3}){sub 2} as chemical modifier. Characteristics mass of 14, 6 and 220 {rho}g and detection limits of the method of 0.07, 0.38 and 0.75 {mu}g L{sup -1} were obtained for Cr, Ni and V respectively. The methodology was validated using a Liphochek Urine Metals Control sample (Bio-Rad) (P=0.05). The methodology was applied to samples of voluntary Venezuelan people, not environmentally exposed to specific emissions, and results ranging from < LOD-1.1 and 1.3-3.3 {mu}g L{sup -1} was observed for Cr and V, respectively, and not detectable levels for Ni. (author)

  8. Determination of the extinction factor in function of the density of dislocations; Determinacion del factor de extincion en funcion de la densidad de dislocaciones

    Energy Technology Data Exchange (ETDEWEB)

    Macias B, L.R

    1991-12-15

    There are exist three basic types of crystalline lattice defects: point, line (or dislocations) and surface defects. Such defects may be incorporated intentionally to produce desired mechanical and physical properties. This report presents a FORTRAN language program to calculate the extinction factor in samples of polycrystalline copper as function of the dislocations density. (Author)

  9. La reflexión y el método. Estudio de las determinaciones reflexivas en la "Ciencia de la Lógica" de Hegel

    OpenAIRE

    Gutiérrez Cuartango, Román

    1992-01-01

    [cat] El tema principal de la tesis es la transformación que tiene lugar en el seno de la "Ciencia de la Lógica", tanto en la reflexión como en la relación de ésta con su asunto. Una tal modificación se convierte en la posibilidad misma del sistema, así como de la totalidad mediada, en la que cabe tanto la crítica de la metafísica como la exposición del absoluto; en uno y el mismo sentido. Además, la “Erhebung” de la reflexión desde su posición habitual, como reflexión abstracta, externa o de...

  10. Determination of the dose index in computerized tomography using thermoluminescent dosemeters; Determinacion del indice de dosis en tomografia computada usando dosimetros termoluminiscentes

    Energy Technology Data Exchange (ETDEWEB)

    Azorin, J.C.; Calderon, A. [Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada-IPN, 11500 Mexico D.F. (Mexico); Azorin, J. [UAM-I, 09340 Mexico D.F. (Mexico)

    2004-07-01

    In this work the obtained results of the determination of the dose index are presented in thorax studies in computed tomography and helical tomography carried out in Mexico using thermoluminescent dosemeters of LiF: Mg,Cu,P + Ptfe developed and manufactured in our country. The results showed that under similar conditions of irradiation and operation (pitch = 1), significant differences don't exist among the doses absorbed measures in the phantom due to the two types of used tomographs. (Author)

  11. The determination of phosphorus in uranium minerals and resulting solutions; Determinacion de fosforo en minerales de uranio y soluciones procedentes de su beneficio

    Energy Technology Data Exchange (ETDEWEB)

    Petrement Eguiluz, J. C.; Rarellada Bellod, R.; Fernandez Cellini, R.

    1964-07-01

    Interferences of several elements present in Spanish uranium minerals in the phosphorus determination by the spectrophotometrical method of the molibdovanada te phosphoric acid are studied. A method is described with a previous separation of these element by a cationic resin. This method is successfully applied to the phosphorus determination in acid or alkaline lixiviation solutions of uranium minerals, as well as in the evaluates of ion exchange resins used used technically for the concentration of solutions with a low uranium content. (Author) 11 refs.

  12. Fluor determination by alkaline hydrolysis of the uranium and thorium fluorides; Determinacion de fluor por hidrolisis alcalina en fluoruros de uranio y torio

    Energy Technology Data Exchange (ETDEWEB)

    Barrachina Gomez, L.; Gasco Sanchez, L.

    1961-07-01

    The alkaline hydrolysis of the uranium and thorium fluorides is studded and a new method for the determination of the fluoride, on the basis of a indirect volumetric titration with standard soda, is proposed. The compounds that may influence the hydrolysis of the uranium fluoride and that may be occasionally found in it as impurities are also studied. the method can be applied to the uranium fluoride except when there is a great quantity of F{sub 2}UO{sub 2} or UO{sub 3} present in the sample. (Author) 20 refs.

  13. Spectrographic determination of metallic impurities in organic coolants for nuclear reactors; Determinacion espectrografica de impurezas metalicas en refrigerantes organicos para reactores nucleares

    Energy Technology Data Exchange (ETDEWEB)

    Martin Munoz, M.; Alvarez Gonzalez, F.

    1969-07-01

    A spectrochemical method for determining metallic impurities in organic coolants for nuclear reactors is given. The organic matter in solid samples is eliminated by controlled distillation and dry ashing in the presence of magnesium oxide as carrier. Liquid, samples are vacuum distillated. The residue is analyzed by carrier distillation and by total burning techniques. The analytical results are discussed and compared with those obtained destroying the organic matter without carrier and using the copper spark technique. (Author) 12 refs.

  14. Direct reading spectrochemical determination of aluminium, iron and silicon in fluorite; Determinacion espectroquimica de lectura directa de aluminio, hierro y silicio en fluorita

    Energy Technology Data Exchange (ETDEWEB)

    Roca, M.

    1966-07-01

    A quantitative spectrochemical method for the determination of Al, Fe and Si in fluorite has been worked out. The sample was supported in a graphite electrode with crater of 5 mm. in diameter, 2,5 mm deep, and burned by a d.c. are in a direct reading spectrometer. The excitation of samples has been studied without dilution as well as using graphite powder as diluent in the ratios 1:1, 1:4, and 1:9; the latter factor was chosen. Ag, Ca, Co, Cr, Mo and Sn were tested as internal standards. It has not been found any significant inter element effect. It is necessary to use natural fluorite as base material for the standards. (Author) 5 refs.

  15. Design quality control of the activity determination total alpha liquid effluents; Diseno de control de calidad de la determinacion de actividad alfa total en efluentes liquidos

    Energy Technology Data Exchange (ETDEWEB)

    Yague, L.; Alvarez, A.; Navarro, N.; Noguerales, C.

    2011-07-01

    The total alpha activity index is the joint action of all alpha emissions in a sample. This is a very useful in designing the analytical control of liquid effluent into the environment. Presents the design of quality control applied to the determination of total alpha activity.

  16. Determination of microquantities of methanol and ethanol in toluene by gas chromatography; Determinacion de microcantidades de metanol y de etanol en tolueno por cromatogrfia de gases

    Energy Technology Data Exchange (ETDEWEB)

    Perez, M. M.

    1970-07-01

    A study is made of the detection of methanol and ethanol in toluene by means of gas chromatography, using Porapak Q columns, 1 m long at 189 degree centigree, employing a flame ionization detector, with propanol as an internal standard. The variation od the detector absolute and relative response was found to be linear within the range of concentration studied, that is, from 5 to 1000 ppm. The limit of sensitivity for the detection of ethanol in a column of 2% Ucon, over Chromosorob G deactivated with 0,1% Carbowax 400, was 20 ppm, which was four times higher than the limit of sensitivity of the Porapak Q column. Also in this case, the absolute and relative response of the detector was linear. (Author) 3 refs.

  17. A model for the determination of the nominal potential for a linear accelerator; Un modelo para la determinacion del potencial nominal de un acelerador lineal

    Energy Technology Data Exchange (ETDEWEB)

    Gutt, F.; Silva, P.; Guerrero, R.; Diaz, J.; Colmenares, J. [Instituto Venezolano de Investigaciones Cientificas (IVIC), Laboratorio Secundario de Calibracion Dosimetrica (LSCD), Apartado 21827, Caracas 1020 A (Venezuela)

    1998-12-31

    The objective of the present work is to find a physical mathematical model based on the reason of the dose percentages at 10 and 20 cm depth, at 100 cm DFS and a 10 x 10 cm{sup 2} field. It was utilized literature data of new manufactured accelerators and those are in use in hospitals, which allow to prove the model under different conditions. Our objective consists only to obtain a model that verifies the nominal potential for a linear accelerator, but without pretending that such a model to be used to calculate any one factor to determination of absorbed dose. (Author)

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

    Directory of Open Access Journals (Sweden)

    Carlos Alberto Severiche Sierra

    2013-06-01

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

  19. Determination of uranium traces in fuel cans of nuclear reactors; Determinacion de trazas de uranio en vainas de combustible de reactores nucleares

    Energy Technology Data Exchange (ETDEWEB)

    Acosta L, C.E.; Benavides M, A.M.; Sanchez P, L.A.; Nava S, G.F. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    1997-07-01

    The objective of this work is to quantify the uranium content that as impurity can be found in zircon and zircaloy alloys which are used in the construction of fuel cans. The determination of this serves as a quality control measure due to that the increment of uranium content in alloy, diminishing the corrosion resistance. The fluorimetric method was used to do this determination. It is a very sensitive, reliable, rapid method also high reproducibility and repeatability as well as low detection limits (0.25 mg/kg). (Author)

  20. Determination of interplanar distances starting from diffraction spectra for PC microcomputer; Determinacion de distancias interplanares a partir de espectros de difraccion para microcomputadora PC

    Energy Technology Data Exchange (ETDEWEB)

    Macias B, L.R

    1991-07-15

    The objective of this work, consists in that starting of a digitized diffraction spectra result of the structural analysis technique, it is possible by means of the analysis of a computer program, to detect the diffraction peaks and well-known the wavelength to obtain the values of the interplanar distances to be compared with the JCPDS (Joint Committee on Powder Diffraction Standards). (Author)

  1. Determinacion de la bioactividad y la resistencia a la compresion de bloques de Poliapatita Determination of the bioactivity and the compression resistance of Poliapatita

    Directory of Open Access Journals (Sweden)

    Haney Castro Fernández

    2010-01-01

    Full Text Available Poliapatita® is a composite in study formed by HAP-200®, CaCO3 and POVIAc®. The aims of this work were the determination of the bioactivity and the compression resistance (CR of biomaterial. The composite was put in contact with a Simulated Body Fluid (28 days at 37 ºC to evaluate the formation of an superficial apatite layer similar to the bone mineral composition; and to see how diminished the CR in conditions similar to implantation. The bioactivity was evaluated mainly by Scanning Electron Microscopy, Energy-dispersive X-ray Spectroscopy. The composite studied was bioactive and fulfills the requierement of CR asked by ISO 13779-1:2001.

  2. Analytical methods for 2,4-D (Dichlorophenoxyacetic acid) determination; Metodos analiticos para la determinacion del 2,4-D (Acido diclorofenoxiacetico)

    Energy Technology Data Exchange (ETDEWEB)

    Martinez G, M.S.M

    1999-06-01

    The 2,4-D herbicide is one of the main pesticides for controlling the bad grass in crops such as the water undergrowth. In Mexico the allowed bound of this pesticide is 0.05 mg/l in water of 2,4-D so it is required to have methods trusts and exacts, which can used in order to detected low concentration of it. In this work we show some for the conventional techniques and for establishing the 2,4-D concentrations. The UV-Vis spectrometer and liquids chromatography due that they are the most common used nowadays. Beside, we introduce a now developed technique, which is based on the neutronic activation analysis. Though use of the UV-Vis spectrometer technique it was possible target the concentrations interval between 1 and 200 mg/l. In the liquids chromatography interval was between 0.1 and 0.9, and by the neutronic activation analysis the interval was between 0.01 and 200 mg/l. (Author)

  3. Determinacio?n de carbono en la biomasa ae?rea de Ceroxylon peruvianum en la cuenca del ri?o Utcubamba

    OpenAIRE

    Maicelo Quintana, Jorge Luis

    2013-01-01

    En la cuenca media del ri?o Utcubamba existen diversas especies nativas, dentro de ellas la que mayor importancia ha demostrado es Ceroxylon peruvianum (pona), forma parte del componente len?oso en los sistemas de produccio?n agropecuaria, ya sea en asociacio?n no sistema?tica como sistemas agroforestales y sistemas silvopastoriles con componentes de especies arbo?reas, pastos cultivados y mejorados y especies de ganado vacuno. El objetivo principal de la investigacio?n fue la determinacio...

  4. 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)

  5. Determination of the particle size distribution in a powder using radiotracers; Determinacion de la distribucion de tamano de particulas en un polvo utilizando radiotrazadores

    Energy Technology Data Exchange (ETDEWEB)

    Revilla D, R

    1974-07-01

    To determine experimentally the particle size distribution in a powder the meshed method is generally used. This method has the disadvantage that in the obtained distribution is not observed at detail the fine structure of such distribution. In this work, a method for obtaining the distribution of particle size using radiotracers is presented. In the obtained distribution by this method it is observed with more detail the fine structure of the distribution, comparing with the obtained results by the classical method of meshed. The radiotracer method has major resolution for the experimental determination mentioned. In the chapter 1, it is done a brief analysis about theoretical aspects related with the method. In the first part it is analysed the particle behavior (sedimenting) in a fluid. The second part treats the relating with the radioactivity of an activated material as well as its detection. In the chapter 2, a description of the method is done also the experimental problems to applying to the alumina crystals sample are discussed. In the chapter 3 the obtained results and the mistake calculations in such results are showed. Finally, in the chapter 4 the conclusions and recommendations are given which is possible to obtain better results and improve to those in this work were obtained. (Author)

  6. Determination of the fast neutrons spectra by the Elastic scattering method (n, p); Determinacion del espectro de neutrones rapidos por el metodo de la dispersion elastica (n, p)

    Energy Technology Data Exchange (ETDEWEB)

    Elizalde D, J

    1973-07-01

    This work consists in determining the fast neutron spectra emitted by a Pu-Be isotopic source. The implemented technique is based in the spectrometry (n, p). This consists in making to fall on a fast neutrons beams (polyenergetic) over a thin film of hydrogenated material, detecting the spectra of emitted protons at a fix angle. The polyethylene film and the used solid state detector are inside of a vacuum chamber. The detector is placed at 30 degree with respect to direction of the incident neutrons beam. The protons spectra is stored in a multichannel. the energy is obtained with the prior calibration of the system. The data processing involves the transformation of the protons spectra observed at the falling on neutrons spectra over the film. The energy of the neutrons is related with that of the protons, according to the collision kinematical equations. The cross section of elastic collision of the neutrons with the hydrogen atoms is obtained from literature. Applying these relations to the observed spectra it is obtained the falling on neutron spectra over the film. (Author)

  7. 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)]. e-mail: jgj@nuclear.inin.mx

    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)

  8. Determinacion de la configuracion E-Z de los acidos Fumarico y Maleico. Un experimento orientado a incentivar el desarrollo de la investigacion cientifica en alumnos de Pregrado

    Directory of Open Access Journals (Sweden)

    Bustos Carlos

    2000-01-01

    Full Text Available In this work we intend to eliminate the idea that laboratory exercises seem like cookbooks. That is, exercises shall be presented as a problematic situation. Based on observation and experimentation, the students should determine the E-Z configuration of maleic and fumaric acids. The basis of this laboratory exercise is the acid-catalyzed isomerization of maleic acid to fumaric acid. Students are given the starting material, reagents and the experimental procedure. They are told that the starting material is a dicarboxylic acid containing a C=C double bond of formula C4H4O4. Students determine melting points, solubilities, acidity and chromatographic patterns for both the starting material and the product, so that a configuration of each acid can be proposed. This type of experiment yields excellent results, because the students are left to deduce that maleic acid is less stable than fumaric acid. Additionally, they conclude that maleic acid is the "Z" isomer and fumaric acid is the "E" isomer. Finally, this laboratory exercise allows the students to develop simultaneously their critical-thinking skills with the respective laboratory techniques and not to see chemistry as recipes to be followed.

  9. Determination of the thickness of radiation equipment computed tomography (CT); Determinacion del espesor de radiacion en equipos de tomografia computarizada (TC)

    Energy Technology Data Exchange (ETDEWEB)

    Gago Gomez, P.; Ayala Lazaro, R.; Gonzalez Ruiz, C.; Hurtado Sanchez, A.; Sierra Diaz, F.

    2011-07-01

    The cutting thickness determination radiologically diagnosed TC teams is usually done directly irradiating a film situated at the height of radiological isocenter, with collimated beams to cut thicknesses nominal and valuing the size of these same in plaque. This test is usually done by measuring directly on the surface irradiated. This affects the measurement accuracy when the tolerance established for this test in the Spanish Protocol as is the uncertainty associated scale. Can be assessed simultaneously moving the table and adjusted the nominal value.

  10. Solvent extraction separation and spectrographic determination of palladium, rhodium and ruthenium in uranium; Determinacion espectrografica de paladio, rodio y rutenio en uranio, mediante separacion previa por extraccion

    Energy Technology Data Exchange (ETDEWEB)

    Capdevilla, C.; Alduan, F. A.

    1980-07-01

    The determination of Pd, Rh and Ru in uranium at low ppm level, using solvent extraction has been studied. BPHA, TNOA, TOPO and TBP have been tried as complexing agents; TBP In hexane and 5 M nitric acid medium provides a virtually quantitative extraction. The layer containing the impurities is collected Into graphite powder, and this powder is analysed spectro graphically using carrier destination method with % CuF{sub 2} as a carrier. (Author) 11 refs.

  11. Monte Carlo simulation: tool for the calibration in analytical determination of radionuclides; Simulacion Monte Carlo: herramienta para la calibracion en determinaciones analiticas de radionucleidos

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, Jorge A. Carrazana; Ferrera, Eduardo A. Capote; Gomez, Isis M. Fernandez; Castro, Gloria V. Rodriguez; Ricardo, Niury Martinez, E-mail: cphr@cphr.edu.cu [Centro de Proteccion e Higiene de las Radiaciones (CPHR), La Habana (Cuba)

    2013-07-01

    This work shows how is established the traceability of the analytical determinations using this calibration method. Highlights the advantages offered by Monte Carlo simulation for the application of corrections by differences in chemical composition, density and height of the samples analyzed. Likewise, the results obtained by the LVRA in two exercises organized by the International Agency for Atomic Energy (IAEA) are presented. In these exercises (an intercomparison and a proficiency test) all reported analytical results were obtained based on calibrations in efficiency by Monte Carlo simulation using the DETEFF program.

  12. Aspectos experimentales de la determinacion de curvas esfuerzo-deformacion a alta temperatura y en atmosfera controlada: Refractarios Al2O3-MgO-C

    Directory of Open Access Journals (Sweden)

    Cavalieri, A. L.

    2011-06-01

    Full Text Available A methodology for the mechanical evaluation of refractory materials at high temperatures and controlled atmosphere, designed and implemented in the Structural Materials Laboratory of Ceramics Division of INTEMA, is described. The methodology includes the measurement of the specimen deformation by contact extensometry in compression tests to obtain stress-strain curves and the use of a gaseous flow as a system to control atmosphere. The determination of stress-strain curves of Al2O3-MgO-C commercial refractories used in steelmaking ladles at room temperature and 1260°C in different atmospheres is presented as an example of application of this methodology.Se presenta una metodología diseñada e implementada en el Laboratorio de Materiales Estructurales de la División Cerámicos del INTEMA para la evaluación del comportamiento mecánico de materiales refractarios a altas temperaturas y en atmósfera controlada. La metodología comprende la determinación de la deformación por extensometría de contacto en ensayos en compresión con el fin de obtener curvas esfuerzo-deformación y el uso de un sistema de control de atmósfera por desplazamiento a través del pasaje de una corriente gaseosa. La determinación de curvas esfuerzo-deformación de ladrillos refractarios comerciales Al2O3-MgO-C utilizados en cucharas de acería a temperatura ambiente y a 1260 °C en diferentes atmósferas se presenta como ejemplo de aplicación de esta metodología.

  13. Analysis of inflow in geothermal wells to determine their maximum flow; Analisis del influjo en pozos geotermicos para la determinacion de sus flujos maximos

    Energy Technology Data Exchange (ETDEWEB)

    Aragon-Aguilar, Alfonso; Izquierdo-Montalvo, Georgina; Pal-Verma, Mahendra; Santoyo-Gutierrez, Socrates [Instituto de Investigaciones Electricas (Mexico); Moya-Acosta, Sara L [Centro Nacional de Investigacion y Desarrollo Tecnologico (Mexico)

    2009-01-15

    Inflow performance relationships developed for petroleum and geothermal reservoirs are presented. Four of them were selected to be used in this work. Such relationships were developed considering features of a typical geothermal system. The performance of the selected relationships was assessed using data from production tests in several wells of different fields. A methodology is presented to determine the value of the maximum flow (W{sub max}) from the inflow relationships; its application is demonstrated using the data of the 10 production tests. It was found that the calculated value of W{sub max} under stabilization conditions may be related to the reservoir response. In general, there is a good agreement between the calculated values of W{sub max} from the different methods. The differences in the W{sub max} values vary within 10%. It was found that the stability in the calculated values of W{sub max} as a response of the reservoir is a function of the flow magnitude. So, the wells with flow greater than 200 t/h reach the stability of W{sub max} at openings 50% less of their total capacity. [Spanish] Se presentan las relaciones del comportamiento de influjo desarrolladas para yacimientos petroleros y geotermicos. Se seleccionaron cuatro de ellas para usar en este trabajo. Tales relaciones fueron desarrolladas considerando condiciones de un sistema geotermico tipico. Se analizo el comportamiento de las relaciones escogidas utilizando datos de pruebas de produccion de varios pozos de diferentes campos. Se presenta una metodologia para determinar el valor del flujo maximo (W{sub max}) a partir de las relaciones de influjo; se demuestra su aplicabilidad usando los datos de diez pruebas de produccion. Se encontro que el valor de W{sub max} calculado bajo condiciones de estabilizacion se puede relacionar con la respuesta del yacimiento. En general se encuentra buena concordancia entre los valores calculados de W{sub max} usando los diferentes metodos. Las diferencias en los valores de W{sub max} varian dentro de 10%. Se encontro que la estabilidad en los valores calculados de W{sub max} como una respuesta del yacimiento es funcion de la magnitud del flujo. Asi para pozos con flujos mayores de 200t/h, la estabilidad en los valores de W{sub max} se alcanza a aperturas menores del 50% de su capacidad total.

  14. Determination of radiation levels by neutrons in an accelerator for radiotherapy; Determinacion de niveles de radiacion por neutrones en un acelerador para radioterapia

    Energy Technology Data Exchange (ETDEWEB)

    Paredes G, L.; Salazar B, M.A. [Instituto Nacional de Investigaciones Nucleares, Apdo. Postal 18-1027, 11801 Mexico D.F. (Mexico); Genis S, R. [Fundacion Clinica Medica Sur, Puente de Piedra 150, Col. Torriello Guerra, Tlalpan 14050, Mexico D.F. (Mexico)

    1998-12-31

    It was determined the radiation levels by neutrons due to photonuclear reactions ({gamma}, n) which occur in the target, levelling filter, collimators and the small pillow blinding of a medical accelerator Varian Clinac 2100C of 18 MeV, using thermoluminescent dosemeters UD-802AS and US-809AS. The experimental values were presented for the patient level, inside and outside of the radiation field, as well as for the small pillow. (Author)

  15. Determination of total alpha activity index in samples of radioactive wastes; Determinacion del indice de actividad alfa total en muestras de desechos radiactivos

    Energy Technology Data Exchange (ETDEWEB)

    Galicia C, F. J.

    2015-07-01

    This study aimed to develop a methodology of preparation and quantification of samples containing radionuclides beta and/or alpha emitters, to determine the rates of alpha and beta total activity of radioactive waste samples. For this, a device of planchettes preparer was designed, to assist the planchettes preparation in a controlled environment and free of corrosive vapors. Planchettes were prepared in three means: nitrate, carbonate and sulfate, to different mass thickness, natural uranium (alpha and beta emitter) and in case of Sr-90 (beta emitter pure) only in half nitrate; and these planchettes were quantified in an alpha/beta counter, in order to construct the self-absorption curves for alpha and beta particles. These curves are necessary to determine the rate of alpha-beta activity of any sample because they provide the self-absorption correction factor to be applied in calculating the index. Samples with U were prepared with the help of the device of planchettes preparer and subsequently were analyzed in the proportional counter Mpc-100 Pic brand. Samples with Sr-90 were prepared without the device to see if there was a different behavior with respect to obtaining mass thickness. Similarly they were calcined and carried out count in the Mpc-100. To perform the count, first the parameters of counter operating were determined: operating voltages for alpha and beta particles 630 and 1500 V respectively, a count routine was generated where the time and count type were adjusted, and counting efficiencies for alpha and beta particles, with the aid of calibration sources of {sup 210}Po for alphas and {sup 90}Sr for betas. According to the results, the counts per minute will decrease as increasing the mass thickness of the sample (self-absorption curve), adjusting this behavior to an exponential function in all cases studied. The minor self-absorption of alpha and beta particles in the case of U was obtained in sulfate medium. The self-absorption curves of Sr-90 follow the same trend as U for beta particles. (Author)

  16. 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)

  17. Experimental petrology for the thermobarometric determination of mineral paragenesis: the fluid inclusions; Petrologia experimental para la determinacion termobarometrica de paragenesis minerales: las inclusiones fluidas

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez Partida, Eduardo; Torres Rodriguez, Vicente; Birkle, Peter [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1994-05-01

    There is a great number of phenomena in nature in which some fluid participates as the main component. Such is the case of oil deposits formation, of metallic minerals, geothermal systems, metamorphic and diagenetic deposits. The common denominator of all of them is that in some part of their stages important physico-chemical processes occurred in the related fluids, leaving evidence of such phenomena in the fluid inclusions. The Geothermal Department has petrologic vanguard tools for reservoir problems resolution, since it has laboratories for the study on fluid inclusions by means of the technique called cryoscopic-microthermometry that permits the definition of physico-chemical conditions of the brine that participated or participates in the hydrothermal systems formation. The method simultaneously permits to know the characteristics of the initial brine that participated in the interaction water-rock phenomenon, observe the boiling phenomena, and determine conditions of initial pressure in the reservoirs. [Espanol] Existe un gran numero de fenomenos en la naturaleza en los que participa algun fluido como componente principal. Tal es el caso de la formacion de yacimientos de petroleo, de minerales metalicos, de sistemas geotermicos, yacimientos metamorficos y diageneticos. El comun denominador de todos ellos es que en alguna de sus etapas ocurrieron procesos fisicoquimicos importantes en los fluidos relacionados, quedando evidencia de tales fenomenos en las inclusiones fluidas. El Departamento de Geotermia cuenta con herramientas petrologicas de vanguardia para la resolucion de problemas en yacimientos, ya que tiene laboratorios para el estudio de las inclusiones fluidas por medio de la tecnica denominada microtermometria-crioscopica que permite definir condiciones fisicoquimicas de la salmuera que participo o participa en la formacion de sistemas hidrotermales. El metodo permite simultaneamente conocer las caracteristicas de la salmuera inicial que participo en el fenomeno de interaccion aguaroca, observar fenomenos de ebullicion y determinar condiciones de presion inicial en los yacimientos.

  18. Determination of the hot rolling stress by means of tensile tests; Determinacion de la tension de laminacion en caliente a partir de ensayos de traccion

    Energy Technology Data Exchange (ETDEWEB)

    Monsalve, A.; Artigas, A.; Celentano, D.; Guzman, A.; Colas, R.; Houbaert, Y.

    2013-03-01

    Prediction of mechanical behavior of hot rolled steels is an important aspect during industrial processing. The rolling stress needed to the process were estimated using three methods, the first of which is related to the Sellars's model that takes into account the friction coefficient and the yield stress. The second method estimates the rolling stress as the average stress obtained during the tensile tests. The third method, estimates the rolling stress from the data of power consumed by the rolling equipment. This methodology was applied in this study to a carbon steel. The conclusion of the work is that results obtained by Sellars's and consumed power, are coincident. The method based on the average tensile stress predicts stresses lower than those obtained with other two methods. (Author) 26 refs.

  19. Determination of {sup 40} K in food and whole body; Determinacion de {sup 40} K en alimentos y en cuerpo entero

    Energy Technology Data Exchange (ETDEWEB)

    Quintero P, E.; Alfaro L, M.M.; Valentin A, G.; Rojas M, V.P. [ININ, 52750 La Marquesa, Estado de Mexico (Mexico)

    2007-07-01

    We present the concentration of radioactivity of {sup 40}K, in samples of some foods consumed by the population settled down in the area of influence of the Nuclear Center of Mexico, using the foods more representative of this area. We also present the concentration of this radioisotope in the human body classified by ages and sex. (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. Determination of potassium by means of the {sup 40}K measurement; Determinacion de potasio mediante la medicion del {sup 40}K

    Energy Technology Data Exchange (ETDEWEB)

    Escareno J, E.; Vega C, H. R., E-mail: edmundoej@hotmail.com [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico)

    2011-11-15

    The concentration of total potassium through the gamma-rays measurement of 1461 KeV emitted during the disintegration of the {sup 40}K was determined. In the nature three isotopes of the K exist: {sup 39}K, {sup 41}K and {sup 40}K, this last is radioactive with a half life of 1.2 x 10{sup 9} years. The {sup 40}K isotope is in a relationship of 0.0117% with regard to the K, this characteristic is used with the purpose of estimating the total quantity of potassium. The potassium has a very important paper in the growth and the reproduction of animals and plants. Due to the secular equilibrium, the emission of {gamma}-rays is proportional to the concentration of K. In this work a group of calibration sources were prepared and a spectrometry system was characterized with NaI(Tl) to determine the concentration of total K. (Author)

  2. Determination of the geothermal well damage from its production tests; Determinacion del dano en pozos geotermicos a partir de sus pruebas de produccion

    Energy Technology Data Exchange (ETDEWEB)

    Aragon Aguilar, Alfonso; Izquierdo Montalvo, Georgina; Arellano Gomez, Victor [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2011-06-13

    In this work the evolution is described that undergoes the factor of damage in a well during its productive stage, which is identifiable from the diminution in the characteristics of its production. It is mentioned that during the productive stage of wells, its declination is, in many occasions, synonymous of the damage presence. Traditionally, the damage effect is determined from the equations for analysis of the transitory tests of pressure. Nevertheless, the execution of this type of tests requires relatively long periods of time to obtain the stabilization of the well and of significant costs. By the previous facts the development of techniques to determine the damage from production tests was initiated. In this article is presented the curve-type of geothermal inflow affected by the damage, from which the value of this one in a geothermal well for the time in which its test of production is realized can be determined. A methodology is proposed to determine the damage effect in the well using the proposed curve-type and its applicability with examples of test measurements of well discharge is demonstrated in Mexican geothermal fields. From the conducted analyses it is found that the numerical value of the damage determined in selected wells increases based on the time of exploitation, which indicates a deterioration of its productive characteristics. The previous statements aid to constitute a technical endorsement for the decision making, on the pertinent actions that can be executed in the well. [Spanish] En este trabajo se describe la evolucion que sufre el factor de dano en un pozo durante su etapa productiva, el cual es identificable a partir de la disminucion en las caracteristicas de su produccion. Se menciona que durante la etapa productiva de los pozos, su declinacion es, en muchas ocasiones, sinonimo de la presencia de dano. Tradicionalmente, el efecto de dano se determina a partir de las ecuaciones para analisis de las pruebas transitorias de presion. Sin embargo, la ejecucion de este tipo de pruebas requiere de periodos relativamente largos de tiempo para lograr la estabilizacion del pozo y de costos significativos. Por lo anterior se empezaron a desarrollar tecnicas para determinar el dano a partir de pruebas de produccion. En este articulo se presenta la curva-tipo de influjo geotermico afectada por dano, a partir de la cual se puede determinar el valor de este en un pozo geotermico para el tiempo en que se realiza su prueba de produccion. Se propone la metodologia para determinar el efecto de dano en el pozo usando la curva-tipo propuesta y se demuestra su aplicabilidad con ejemplos de mediciones de pruebas de descarga en pozos de campos geotermicos mexicanos. De los analisis efectuados se encuentra que el valor numerico del dano determinado en los pozos seleccionados aumenta en funcion del tiempo de explotacion, lo cual indica un deterioro en sus caracteristicas productivas. Lo anterior ayuda a conformar un respaldo tecnico para la toma de decisiones, sobre las acciones pertinentes que pueden ejecutar en el pozo.

  3. Determination of low concentrations of thorium in geological materials by X-ray fluorescence; Determinacion de bajas concentraciones de torio en materiales geologicos mediante fluorescencia de rayos X

    Energy Technology Data Exchange (ETDEWEB)

    Roca, M.; Bayon, A.

    1981-07-01

    An X-ray fluorescence method for the determination of thorium in geological samples down to 2 ppm ThO{sub 2} has been developed. To achieve this determination limit an exposed area of the sample 42.5 mm in diameter is used, working with a molybdenum target tube operated at 90 kV and 30 m A. Corrections for background and line interference of the Rb K{alpha} radiation have been carefully considered and empirical correction coefficients calculated. (Author) 3 refs.

  4. X-Ray Fluorescence Spectrometry. I.- Determination of thorium in ores; Espectrometria de fluorescencia de rayos X. A.- Aplicacion a la determinacion de torio en minerales

    Energy Technology Data Exchange (ETDEWEB)

    Bermudez Polonio, J.; Crus Castillo, F. de la; Fernandez Cellini, R.

    1961-07-01

    A X-ray spectrometric method has been developed for analysis of thorium in ores in the range of concentration from 0.01 to 0.5 percent ThO{sub 2}, using selenium as a internal standard. The concentration of thorium is determined in a working curve prepared by plotting the percentage of ThO{sub 2} against the ratio intensity of the Th L{alpha}{sub 1} line to Sek{sub {beta}}1 line. (Author) 17 refs.

  5. Determination of Sn in 99{sup m}Tc Radiopharmaceutical Kits by Polarographic Methods; Determinacion de Estano en Radiofarmacos de 99{sup m}Tc mediante Metodos Polarograficos

    Energy Technology Data Exchange (ETDEWEB)

    Castro, M.; Cruz, J.; Sanchez, M.

    2009-07-01

    Kits of 99{sup m}Tc radiopharmaceuticals are used in nuclear medicine for diagnosis of different diseases. Sn (II) is one of the essential components in their formulations, which is used for reduction 99{sup m}Tc-pertechnetate in cold kits for on-site preparation 99{sup m}Tc-pertechnetate radiopharmaceuticals. Usually, these cold kits contain different additives (complexing agents, antioxidants, buffers, etc.) and the amount of Sn (II) varies from kit to kit. The determination of Sn in these products is essential in assessing their quality. We report here the development of a new polarographic method for the determination of Sn (II) and total Sn in representative radiopharmaceuticals kits (for the content of Sn and chemical composition) produced at the Center of Isotopes of Cuba (CENTIS). These methods were validated by analysis of variance and recovery techniques. From the results of the validation, the characteristic functions of uncertainties and fits are considered for the established methods, which give the necessary evidences to demonstrate the usefulness of these methods according to the current trends in Analytical Chemistry. This work provides practical results of great importance for CENTIS. After the speciation of Sn in the MAG3 radiopharmaceuticals kit is inferred that the production process is affected by uncontrolled factors that influence in the product stability, which demonstrates the necessity for analytical tools for the characterization of products and processes. (Author) 57 refs.

  6. Location and determination of steps of capacitors in shunt for distribution power lines; Localizacion y determinacion de pasos de capacitores en derivacion para lineas de distribucion

    Energy Technology Data Exchange (ETDEWEB)

    Pampin Vergara, Gabriela; Sarmiento Uruchurtu, Hector [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2001-07-01

    A methodology is presented to determine the optimal location of the capacitor banks in shunt for distribution networks. The proposed tool allows knowing the bank type to install (fixed, disconnect able or of pass), as well as the electrical parameters of the feeder and the economic benefit that the banks of capacitors represent, with a minimum of input data. Its development in a spreadsheet allows the analysis of numerous alternatives in an easy way. The method is based on that the structure of the feeders of distribution is, generally, of radial type, with which, and by means of an iterative process, the optimal location of the capacitor banks in shunt is looked for. The type of bank is determined based of the demand, as well as the number of steps. The results of the analysis in feeders of the network of the central area are shown. [Spanish] Se presenta una metodologia para determinar la localizacion optima de los bancos de capacitores en derivacion en redes de distribucion. La herramienta propuesta permite conocer el tipo de banco a instalar (fijo, desconcectable o de paso), asi como los parametros electricos del alimentador y el beneficio economico que representan los bancos de capacitores, con un minimo de datos de entrada. Su desarrollo en una hoja de calculo permite el analisis de numerosas alternativas de manera facil. El metodo se basa en que la estructura de los alimentadores de distribucion es, por lo general, de tipo radial, con lo cual, y por medio de un proceso iterativo, se busca la localizacion optima de los bancos de capacitores en derivacion. Se determina el tipo de banco en funcion de la demanda, asi como el numero de pasos. Se muestran resultados del analisis en alimentadores de la red del area central.

  7. Determination of the costs of the nuclear desalination using the DEEP code from IAEA; Determinacion de los costos de la desalacion nuclear utilizando el codigo DEEP del OIEA

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez S, J.R.; Palacios H, J.C.; Alonso V, G. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)]. e-mail: jrrs@nuclear.inin.mx

    2005-07-01

    The desalination of seawater is being an important solution to satisfy the demands of drinking water to population's centers that have hydric resources very limited, like it is the case of some Arab countries and arid regions of the planet, in where they have settled desalination plants that use as energy source to those fossil fuels or nuclear energy plants. Taking into account that the desalination of seawater is a process that consumes a lot of thermal and/or electric energy, it is necessary to quantify the costs of the supply and that of the desalination plant for different options and technologies, looking for this way the but appropriate for the specific conditions of the region where it has planned the desalination of seawater. In this report the three technologies but promising for the desalination are described and by means of the DEEP code the costs of production of water and energy are evaluated, using as thermal source different types of power nuclear reactors. It was obtained according to DEEP that the costs of the electricity generation for the considered reactors are around 40 USD/MWh. With these costs of electric power generation and using the DEEP code is obtained that the costs of production of drinking water are around 1 USD/m{sup 3}. (Author)

  8. Analytical Comparison of Miniaturized Methods for Selected PAH Determination in Clean Waters; Comparacion Analitica de 4 Metodos Miniaturizados de Determinacion de PAHs mediante HPLC en Aguas

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, S.; Perez, R. M.; Fernandez, O.

    2012-04-11

    A study on the comparison and evaluation of 4 miniaturized extraction methods for the determination of selected PAHs in clear waters is presented. Four types of liquid-liquid extraction were used for chromatographic analysis by HPLC/ FD. The main objective was the optimization and development of simple, rapid and low cost methods, minimizing the use of extracting solvent volume. The work also includes a study on the scope of the methods developed at low and high levels of concentration. (Author) 13 refs.

  9. Determination of copper in geological materials by X-ray fluorescence; Determinacion de cobre en materiales geologicos mediante fluorescencia de rayos X

    Energy Technology Data Exchange (ETDEWEB)

    Roca, M.; Bayon, A.

    1981-07-01

    X-ray fluorescence has been applied to the determination of copper content of geological materials in the concentration range of 0.01 to % CuO. A molybdenum target tube Is used, samples being presented in finely-ground powder form. Various methods for the correction for background and Instrumental copper interferences have been considered. To correct for matrix effects different tube scattered primary radiations have been tested as references or internal standards. MoK(41 - (C) provides the most suitable results. The use of influence empirical coefficients for the effect of iron on copper and of mass absorption coefficients has also been considered. For samples with a high content of lead, several procedures to correct for I t s influence have been investigated. Comparison between data obtained by X-ray fluorescence and wet-chemical techniques indicated good agreement. (Author) 6 refs.

  10. Direct determination of uranium in human urine by Icp-SFMS; Determinacion directa de uranio en orina humana por ICP-SFMS

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez M, H. [ININ, Departamento de Quimica, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Yllera de Ll, A., E-mail: hector.hernandez520@gmail.com [Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas, Departamento de Medio Ambiente, Av. Complutense 22, 28040 Madrid (Spain)

    2013-10-15

    The success of the measurement and the evaluation of the internal exposure are highly dependent of the effective capacities for the radiation measurement in biological samples (mainly urine and the feces). Usually, during the samples bioassay of human urine, a pre-concentration and purification of the radionuclides is carried out previously to the quantitative analysis. These stages, as the analysis time are the main source of uncertainty in the measurement process. In the uranium case, this is not necessary when are used mass spectrometry techniques, in particular, Mass Spectrometry of Magnetic Sector with Inductively Coupled Plasma (Icp-SFMS). This work presents the results obtained for the uranium analysis in samples of human urine during the participation in the inter-comparison exercises of the Association pour la Promotion de Controle de Qualite des Analyses de Biologie Medicale en Radiotoxicologie (PROCORAD) in the period 2010 and 2011. The analyses were realized directly in the diluted urine samples (dilution factor 1:20) in 5% of HNO{sub 3}. The obtained results, were normalized to the total urine sample (V = 0.5 L), these values coincide with the waited reference values of uranium in the urine sample. Additionally, were calculated the detection limits of {sup 235}U= 0.049 x 10{sup -3} μg L{sup -1} and {sup 238}U= 7.37 x 10{sup -3} μg L{sup -1}. (author)

  11. Claves y pautas graficas en la determinacion de edad en dos especies del genero Thryothorus (Troglodytidae) en el Pacifico de Nicaragua

    Science.gov (United States)

    Marvin Torrez; Wayne J. Arendt

    2011-01-01

    Photographic key to determine age in two Thryothorus wrens from Nicaragua's Pacific slope. – We used plumage and molt characteristics to determine age in two Neotropical species of the family Troglodytidae, Rufous-and-White Wren (Thryothorus rufalbus) and Plain Wren (T. modestus). Color density, shape, and strength of the black barring in the remiges, rectrices,...

  12. Determination of NAPL contamination and evolution of remediation by means nuclear techniques; Determinacion de contaminacion NAPL y evolucion de remediacion mediante tecnicas nucleares

    Energy Technology Data Exchange (ETDEWEB)

    Balcazar, M.; Pena, P.; Lopez, A.; Flores, J. H.; Villegas, D. [ININ, 52750 La Marquesa, Estado de Mexico (Mexico); Schubert, M.; Knoller, K. [UFZ, Helmholtz Centre for Environmental Research-UFZ, Permoserstr. 15, 04318 Leipzig (Germany)]. e-mail: mbg@nuclear.inin.mx

    2008-07-01

    In this work the application of two nuclear techniques is presented: Natural radioactive tracer and stable isotopics tracer, that allow the localization and delimitation of the contamination in ground and underground water for hydrocarbons denominated NAPL. The work was carry out on the whole and with access permission to facilities and technical information, in a storage center and distribution of fuel of hydrocarbons where occurred a spill for hydrocarbons, approaching actions of remediation that allow to the date to fulfill the normative one applicable. By means of measurement of {sup 222} Rn, in situ, it was possible to be related its ground concentration to the degree of contamination previously determined; the evaluation of {sup 222} Rn in underground water in group with the determination of stable isotope {delta}{sup 34}S, {delta}{sup 18}O and {delta}{sup 13}C as well as the dissolved inorganic coal allowed to locate the contamination source in underground water to 100 m of depth in the aquifer and to determine the existence of a natural bioremediation. (Author)

  13. Determination of radon in the air of housings of the Aguascalientes municipality; Determinacion de radon en el aire en viviendas del municipio de Aguascalientes

    Energy Technology Data Exchange (ETDEWEB)

    Jasso G, M.R.; Lira P, M.G.; Bonilla P, A.; Ruvalcaba S, L.; Gutierrez S, K.M.; Sandoval A, G.E. [Instituto Tecnologico de Aguascalientes, Av. Lopez Mateos 1801, 20256 Aguascalientes (Mexico); Sanchez H, L. [CNSNS, Dr. Barragan 779, 03020 Mexico D.F. (Mexico)]. e-mail: jassogonzalezre@yahoo.com.mx

    2006-07-01

    This study reports the results of the first exploratory sampling of the radon concentration in the air in a group of housings of the Aguascalientes City, Mexico. The municipality of Aguascalientes was divided in 4 sampling areas considering a total of 179 housings. In these housings, the radon concentration in the air was monitored during a period of 10 days. The results obtained in this study indicate that the radon concentration in the air of 45% of the sampling housings overcomes the concentration limit of 250 Bq/m{sup 3} suggested by the EPA. (Author)

  14. Determination of the load state of lead-acid batteries using neural networks; Determinacion del estado de carga de baterias plomo-acido utilizando redes neuronales

    Energy Technology Data Exchange (ETDEWEB)

    Cristin V, Miguel A; Ortega S, Cesar A [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2005-07-01

    The charge of lead-acid batteries (LAB), as in any other type of batteries, consists of replacing the energy consumed during the discharge. Nevertheless, as no physical or chemical process is good enough to totality recharge a battery, it is necessary to supply to it more than the 100% of the energy demanded during its discharge. A critical factor to make a suitable load control of the batteries is to determine its own state of load. That is to say, to have an efficient load control, it is necessary to count on means that allow to accurately determining the residual capacity of the battery to deliver load. This one is the one of the aspects of greater interest in the research centers around world. For this reason, in this work it was pretended to develop a calculation algorithm of the state of load of batteries based on a fuzzy-neural network that could calculate the state of load without using the battery current as an input. This is because one of the main problems for the designers of battery load controllers is the correct supervision of the current that circulates around the system in all the rank of operation of the same one because the sensors do not have a linear behavior. [Spanish] La recarga de baterias plomo-acido (BPA), como cualquier otro tipo de baterias, consiste en reponer la energia consumida durante la descarga. Sin embargo, como ningun proceso fisico o quimico es lo bastante eficiente para recargar a totalidad una bateria, es necesario suministrarle mas del 100% de la energia demandada durante su descarga. Un factor critico para realizar un adecuado control de carga de las baterias, es determinar su propio estado de carga. Es decir, para tener un control de carga eficiente, es necesario contar con un medio que permita determinar con precision la capacidad remanente de la bateria para entregar carga. Este es uno de los aspectos de mayor interes en los centros de investigacion alrededor el mundo. Por tal razon, en este trabajo se propuso desarrollar un algoritmo de calculo del estado de carga de baterias basado en una red neuro-difusa que pudiera calcular el estado de carga sin utilizar la corriente de la bateria como entrada. Ello se debe a que uno de los principales problemas para los disenadores de controladores de carga de bateria es la correcta supervision de la corriente que circula por el sistema en todo el rango de operacion del mismo pues los sensores no tienen un comportamiento lineal.

  15. Determination of Cr and Cd concentration adsorbed by chicken feathers; Determinacion de concentracion de Cr y Cd adsorbido por plumas de pollo

    Energy Technology Data Exchange (ETDEWEB)

    Lopez M, A.; Cuapio O, L.A.; Cardenas P, S.; Balcazar, M. [ININ, 52750 La Marquesa, Estado de Mexico (Mexico); Jauregui, V.; Bonilla P, A. [ITA, Aguascalientes (Mexico)

    2008-07-01

    In this work the results of the samples analysis of chicken feathers are presented, used as adsorber of the heavy metals Cd and Cr present in water solutions with well-known concentrations of these metals. It was used the Neutron Activation Analysis technique (AAN), using the TRIGA Mark-III reactor of the Nuclear Center of Mexico. The obtained results they show the advantages of having a versatile installation for the analysis of this type of samples. By means of the analysis of the results, it was determined the feasibility of using chicken feathers like adsorber of these metals present in polluted waters, additionally, it was detected the presence of others polluting elements in the inputs to prepare the reference solutions as well as in the processes, so much of preparation of the feathers like of the metals adsorption. (Author)

  16. Methods of Uranium Determination in solutions of Tributyl Phosphate and Kerosene; Metodos de determinacion de uranio en soluciones de fosfato de tributilo y queroseno

    Energy Technology Data Exchange (ETDEWEB)

    Petrement Eguiluz, J.; Palomares Delgado, F.

    1962-07-01

    A new analytical method for the determination of uranium in organic solutions of tributyl phosphate and kerosene is proposed. In this method the uranium is reectracted from the aqueous phase by reduction with cadmium in acid solution. The uranium can be determined in this solution by the usual methods. In case of very diluted solutions, a direct spectrophtometrical determination of uranium in the organic phase with dibenzoylmethane is proposed. (Author) 21 refs.

  17. Determination of {sup 2}30Th (Ionium) in uranium ores and wastes from uranium reprocessing. IV. Calculation of ionium separation yield; Determinacion de {sup 2}39Th (Ionio) en minerales y residuos del procesado de Uranio. IV: Determinacion del rendimiento en la separacion del {sup 2}30 Th

    Energy Technology Data Exchange (ETDEWEB)

    Galiano Sedano, J. A.; Acena Barrenechea, M. L.

    1974-07-01

    For determining ionium ({sup 2}30Th) in minerals and uranium processing wastes by precipitation with fluorhidric acid, using lanthanum as carrier, and selective extraction with tenoytrifluoroacetone (TTA) followed by radiometric determination of the isolated nuclide, it is necessary the use of a tracer since the chemical yield of the separation ranges between wide limits. In this paper, the use of the beta-emitter {sup 2}34Th as the most convenient tracer is discussed. Equations are derived for correcting for counting errors introduced by other thorium isotopes which are present either in the sample or in the tracer, as well as for calculating the chemical yield of the separation. These equations have been experimentally checked by ionium determinations carried out with different types of samples. (Author) 18 refs.

  18. Determination of the stability of the uranyl ion sipped in {tau}-hydrogen phosphate of zirconium in sodic form; Determinacion de la estabilidad del ion uranilo sorbido en {tau}-hidrogenofosfato de zirconio en forma sodica

    Energy Technology Data Exchange (ETDEWEB)

    Ordonez R, E.; Fernandez V, S.M. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico); Drot, R.; Simoni, E. [Universite de Paris-Sud-XI, Institut de Physique Nucleaire d' Orsay, Groupe de radiochimie, Bat. 100, 91406 Orsay (France)]. e-mail: edo@nuclear.inin.mx

    2005-07-01

    The stability of the uranyl sipped in the zirconium {tau}-hydrogen phosphate in sodic form ({tau}-NaZrP), was carried out characterizing the complexes formed by Laser spectroscopy in the visible region and by X-ray photoelectron spectroscopy. The material was prepared by a new synthesis technique working in nitrogen atmosphere and to low temperatures. The sorption of the uranyl ion was made in acid media with concentrations of 10{sup -4} and 10{sup -5} of uranyl nitrate and with ion forces of 0.1 and 0.5 M of NaClO{sub 4}. The spectra of induced fluorescence with laser (TRLFS) show that the uranyl is fixed in very acid media in three well differentiated species, to pH less acid, the specie of long half life disappears and are only those of short half life. The results of the binding energy obtained by XPS indicate that the binding energy of the uranyl confer it a stable character to the complex formed in the {tau}-NaZP, that makes to this material appropriate to retain to the uranyl in solution to high ion forces and in acid media. (Author)

  19. Validation of the technique of kinetic fosforimetria induced by laser for the determination of the concentration of uranium in urine; Validacion de la tecnica de fosforimetria cinetica inducida por laser para la determinacion de la concentracion de uranio en orina

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez, C.; Sierra, I.; Benito, P.; Lopez, C.

    2013-07-01

    This paper describes the methodology used to conduct the validation of the method of determination of uranium using the technique of Kinetic Phosphorescence Analyser (KPA) The technical requirements of the standard 17025 stresses the need for validation samples KPA urine of workers exposed to risk of internal contamination. (Author)

  20. Determination of the ratio between phosphorus and uranium in surface waters selected in the State of Mexico; Determinacion de la relacion entre fosforo y uranio en cuerpos de agua seleccionados en el Estado de Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Ordonez R, E

    2001-07-01

    The agricultural regions lately, they have suffered a severe contamination for the big ones quantities of chemical fertilizers and of pesticides applied to improve their production and quality, increasing these in areas with temperatures but you lower that the average. For the importance of the physicochemical processes that they are made in the waters to settle down surface near to agricultural fields, the physicochemical characteristics were analysed of these waters to determine the contributions that they carry out the phosphate fertilizers that are carried by the escorrentia toward the borders and to make a pursuit of their variability during an agricultural cycle, in times of the summertime and of rains, as well as to observe the effect of the depth in these physicochemical properties. Its were sampling three borders and a spring that it served of white, all them located in the suburbs of the Xinantecatl (Nevado de Toluca), municipality of Zinacantepec, State of Mexico, area with the temperatures but drops registered in the region. They were carried out samplings in the first days of the months of April, July and November. The points of those sampled borders were the influent, the effluent and 3 different depths (lm, 3m and 5m). where was not possible sampling all the points, its were sampling only the one influent and the effluent. The selected physicochemical parameters were the temperature, the pH, the conductivity electric and the one oxygenates dissolved This determination in situ you carries out with a team portable of type Check-Mate, of interchangeable electrodes. The certain anions they were phosphates, nitrates, sulfates and bicarbonates; the measurement of the concentration of anions, one carries out for ultraviolet-visible light spectroscopy and titration. The cations analysed they were sodium, potassium, iron, calcium and magnesium. The cations concentration was determined by atomic absorption spectroscopy. The determination of the uranium concentration it was made by means of neutron activation analysis. The physicochemical parameters diminished of value in the temporary analysis, as long as those anions and the cations didn't show a behavior defined in this same analysis, while in the analysis in depth these parameters presented minimum changes. In the modelling one for computer packages, the results of the speciation analysis chemistry, by means of the Medusa program, they revealed that the species of uranium in solution but abundant they were phosphate uranyl monoacid, tris uranyl carbonate and bis uranyl carbonate and, in smaller proportion, the species of aqueous uranyl hydroxide. The characterization of waters for the program GWW gave as a result that the facies but representative it was the bicarbonate magnesia. In the study of the quality of the one it dilutes with ends of agricultural watering, they were classified as capable for this purpose. The analysis statistical one carries out with base in the correlation coefficient whose value among the uranium and the match is moderated in three sampling points. (Author)

  1. Determination of Fe-55 and Ni-63 in Environmental Samples. Analytical Problems. Characteristic Limits. Automatized Calculation; Determinacion de 55{sup F}e y 63{sup N}i en Muestras Ambientales. Problemas Analiticos. Limites Caracteristicos. Calculo Automatizado

    Energy Technology Data Exchange (ETDEWEB)

    Gasco, C.; Navarro, N.; Gonzalez, P.; Heras, M. C.; Gapan, M. P.; Alonso, C.; Calderon, A.; Sanchez, D.; Morante, R.; Fernandez, M.; Gajate, A.; Alvarez, A.

    2008-08-06

    The Department of Vigilance Radiologica y Radiactividad Ambiental from CIEMAT has developed an appropriate analytical methodology for Fe-55 and Ni-63 sequential determination in environmental samples based on the procedure used by RIS0 Laboratories. The experimental results obtained in the mayor and minor elements behaviour (soil and air constituents) in the different types of resins used for separating Fe-55 and Ni-63 are showed in this report. The measuring method of both isotopes by scintillation counting has been optimized with Ultima Gold liquid with different concentrations of stable element Fe and Ni. The decontamination factors of different gamma-emitters are experimentally determined in this method with the presence of soil matrix. The Fe-55 and Ni-63 activity concentrations and their associated uncertainties have been calculated from the counting data and sample preparation. A computer application has been implemented in Visual Basic in excel sheets for: (I) obtaining the counting data from spectrometer and counts in each window, (II) representing graphically the background and sample spectrums, (III) determining the activity concentration and its associated uncertainty and (IV) calculating the characteristic limits using ISO 11929 (2007) with various confidence levels. (Author) 30 refs.

  2. Uncertainty Evaluation and Influence of Gran Size to Determine PAHs in a Contaminated Soil; Influencia del Tamano de Particula de un Suelo Contaminado en las Incertidumbres Asociadas al Metodo de Determinacion de PAHs

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Alonso, S.; Perez Pastor, R. M.; Escolano Segoviano, O.; Garcia Frutos, F. J.

    2007-07-20

    An evaluation of uncertainty associated to PAH determination in a contaminated soil is presented. The work was focused to measure the influence of grain size on concentration deviations and give a measure of result confidence of PAHs in the gasworks contaminated soil. This study was performed in the frame of the project 'Assessment of natural remediation technologies for PAHs in contaminated soils'(Spanish Plan Nacional I+D+i, CTM 2004-05832-CO2-01). This paper is presented as follows: A brief introduction which describes the main uncertainty contributions associated to chromatographic analysis. Afterwards, a statistic calculation was performed to measure each uncertainty component. Finally, a global uncertainty was calculated and the influence of grain size and distribution of compounds according to volatility was evaluated. (Author) 10 refs.

  3. A Simple Analytical Method Using HPLC with Fluorescence Detection to Determine Selected Polycyclic Aromatic Compounds in Filter Samples; Metodo Analitico Sencillo para la Determinacion de Compuestos Aromaticos Policiclicos en Muestras de Filtros mediante HPLC con Detector de Fluorescencia

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, S.; Perez, R. M.

    2014-06-01

    A study on the comparison and evaluation of a miniaturized extraction method for the determination of selected PACs in sample filters is presented. The main objective was the optimization and development of simple, rapid and low cost methods, minimizing the use of extracting solvent volume. The work also includes a study on the intermediate precision. (Author)

  4. Determination of tolerances in the positioning of the treatment table from an image-guided system; Determinacion de tolerancias en el posicionamiento de la mesa de tratamiento a partir de un sistema de imagen guiada

    Energy Technology Data Exchange (ETDEWEB)

    Perez Moreno, J. M.; Zucca Aparicio, D.; Fernandez leton, P.; Garcia Ruiz-Zorrilla, J.; Minanbres Moro, A.

    2011-07-01

    The use of techniques of image-guided radiotherapy (TGRT) aims to reduce the uncertainties associated with patient positioning. One of the techniques more recent development is the cone beam CT (CBCT), consisting of the acquisition of volumetric images of the patient by a detector integrated into the linear accelerator. By analyzing the results of all sessions of treatment to all patients in which the positioning has been carried out with image-guided system MV CBCT have been determined tolerance tables for translational coordinates of the table treatment based on pathology and immobilization system used. (Author)

  5. Method for determining the wedge angle from the daily measurements made with the measurement enabled devices DC6; Metodo para la determinacion del angulo de cuna a partir de las medidas diarias realizadas con el dispositio de medida QC6

    Energy Technology Data Exchange (ETDEWEB)

    Marques Fraguela, E.; Suero Rodrigo, M. A.

    2011-07-01

    The aim of this paper is to present a method for determining the angle of the wedges virtual electron linear accelerator (ALE) Siemens Primus, from the daily measurements made with the measurement system PTW-QC6Plus and found to be sufficiently sensitive to determine variations of {+-} 1 of this parameter. In addition, we study the behavior statistically CUFLE angle over a year.

  6. Quantitative determination of alpha-quartz in airborne dust samples by x-ray diffraction; Determinacion cuantitativa de cuarzo-alfa en polvo atmosferico mediante difraccion de rayos X

    Energy Technology Data Exchange (ETDEWEB)

    Bayon, A.; Roca, M.

    1982-07-01

    The quantitative determination by X-ray diffractometry of alpha-quartz In airborne respirable dust samples on silver membrane filters is considered. A cobalt anode X-ray tube Is employed. NiO is used as Internal standard In order to compensate for both the variations of specimen absorption and the effect due to the nonuniformity of the incident X-ray beam and to the incomplete homogeneity on the filters of samples and standards. (Author) 17 refs.

  7. An Evaluation of Uncertainty Associated to Analytical Measurements of Selected Polycyclic Aromatic Compounds in Ambient Air; Estudio sobre las Incertidumbres Asociadas al Metodo de Determinacion de PAC's Seleccionados en Muestras de Aire Ambiente

    Energy Technology Data Exchange (ETDEWEB)

    Barrado, A. I.; Garcia, S.; Perez, R. M.

    2013-06-01

    This paper presents an evaluation of uncertainty associated to analytical measurement of eighteen polycyclic aromatic compounds (PACs) in ambient air by liquid chromatography with fluorescence detection (HPLC/FD). The study was focused on analyses of PM{sub 1}0, PM{sub 2}.5 and gas phase fractions. Main analytical uncertainty was estimated for eleven polycyclic aromatic hydrocarbons (PAHs), four nitro polycyclic aromatic hydrocarbons (nitro-PAHs) and two hydroxy polycyclic aromatic hydrocarbons (OH-PAHs) based on the analytical determination, reference material analysis and extraction step. Main contributions reached 15-30% and came from extraction process of real ambient samples, being those for nitro- PAHs the highest (20-30%). Range and mean concentration of PAC mass concentrations measured in gas phase and PM{sub 1}0/PM{sub 2}.5 particle fractions during a full year are also presented. Concentrations of OH-PAHs were about 2-4 orders of magnitude lower than their parent PAHs and comparable to those sparsely reported in literature. (Author) 7 refs.

  8. Implementation in laboratories of Latin America of procedures of harmonized essay for the determination of the radioactive contamination of food; Implementacion en laboratorios de Latinoamerica de procedimientos de ensayo armonizados para la determinacion de la contaminacion radiactiva de alimentos

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez G, I.M. [CPHR (Cuba); Iglicki, F.A. [CNEA (Argentina); Aguirre G, J. [CNSNS, (Mexico); Melo F, A.C. de [Instituto de Radioprotecao e Dosimetria, (Brazil); Tomicic M, I.J. [Comision Chilena de Energia Nuclear, (Chile); Loria M, L.G. [Centro de Investigacion en Ciencias Atomicas Nucleares y Moleculares, (Costa Rica); Diodati, J.M. [ARN, Av. Del Libertador 8250, Buenos Aires (1429), (Argentina); Vasquez B, L.R. [Comision Ecuatoriana de Energia Atomica, (Ecuador); Alarcon S, F.A. [Centro de Investigaciones y Aplicaciones Nucleares, El Salvador (El Salvador); Civil, M. [Laboratoire Veterinaire et de Controle de Qualite des Aliments, (Haiti); Naut M, B.C. [Universidad Autonoma de Santo Domingo, Republica Dominicana (Dominican Republic); Odino M, M.R. [Direccion Nacional de Energia y Tecnologia Nuclear (Uruguay); Flores M, Y.R. [Direccion General de Energia Atomica, (Venezuela); Rossbach, M. [International Atomic Energy Agency, (Austria)]. e-mail: isis@cphr.edu.cu

    2006-07-01

    In Latin America, nowadays, it is not had harmonized essay procedures for the determination of radioactive contaminants in foods. Equally, the great diversity of institutions that in each country are devoted to carry out this control and the difference in the level that its possess the same ones in quality matter, its impose the necessity to implant a Quality Management System on the base of harmonized technical criteria that its help to obtain reliable analytical results. With this end, it was proposed and it was approved the ARCAL LXXIX regional project: 'Harmonization of the technical and specific requirements of quality for the control of the radioactive contamination of foods'. In this work the aspects more significant of the design and content of the Manual of technical procedures for the determination of radioactive contaminants in foods, elaborated in the marks of the one referred project are presented. The same one includes eight procedures for the previous treatment of the samples, the spectrometric determination of gamma emitters radionuclides, the determination of the alpha activity indexes and total beta, of {sup 131} I, {sup 89,90} Sr, {sup 226} Ra, {sup 238,} {sup 239} Pu and {sup 3} H, using different methodologies validated in the region. The actions carried out to implement this Manual are also exposed. (Author)

  9. Determination of metal traces in lubricating oils by Aas and Icp-SFMS after microwave digestion; Determinacion de trazas metalicas en aceites lubricantes mediante EAA e ICP-SFMS despues de la digestion por microondas

    Energy Technology Data Exchange (ETDEWEB)

    Perez B, M. A.; Acosta L, C. E.; Hernandez M, H.; Romero G, E. T.; Lara A, N.; Kuri C, A., E-mail: manuel.perez@inin.gob.mx [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2016-09-15

    The analysis of lubricating oils allows to monitor the operating conditions of the machines and equipment, their pollution levels, degradation and finally their wear and useful life, as well as to establish a preventive lubrication program as a technical diagnostic maintenance tool. The useful life of oil is the period of functional time has in the machine until the antioxidants are consumed, producing large changes in the physical (density and viscosity) and chemical properties of the base oil, resulting in a wear of the components that make up the machine. The present work includes a theoretical as well as analytical basis for determining the content of metallic elements (Ag, Al, Cu, Fe, Mg, Sn and Zn) at trace level in used lubricating oils. A simple and rapid method of analysis is proposed, consisting mainly of the pretreatment of the sample by acidic digestion with a microwave oven. Subsequently an open digestion in a heating plate is carried out to dryness and recovered with concentrated HNO{sub 3}. For the quantitative analysis two analytical techniques were used: flame atomic absorption spectroscopy (Aas) and magnetic sector mass spectrometry with inductively coupled plasma source (Icp-SFMS). In both cases, the proposed method offers a good linearity and sensitivity for each of the trace elements under study. The accuracy of the method expressed as relative standard deviation ranges from 1.4 to 2.3%. In relation to the accuracy measurement, an oil was also analyzed as a certified reference material (Conostan 500 mg/L), with the concentration of certified Mg, obtaining satisfactory results. (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. Application of the exact distribution pj{sub k} in the determination of kinetic parameters in a reactor; Aplicacion de la distribucion exacta p{sub k} a la determinacion de parametros cineticos de un reactor

    Energy Technology Data Exchange (ETDEWEB)

    Alca Ruiz, F.

    1982-07-01

    In this report one distribution of neutron counts obtained by a detector placed in a reactor is studied in order to be used in the determination of reactor kinetic parameters such as {beta}/{lambda} and reactivities. The parameters accuracy from this new method is compared with the Feynman and Mogilner method, based too in Reactor Neutron Noise Analysis. These three methods have been applied to JEN-2 reactor and the better accuracy and faster collection of experimental data give some interest to the new method which only requires a good footing code. (Author) 68 refs.

  12. Analytical Evaluation to Determine Selected PAHs by HPLC in a Type 2 Fuel; Evaluacion Analitica de 4 Metodos de Determinacion de PAHs medianteHPLC en un Fuel de Tipo II

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Alonso, S.; Perez Pastor, R. M.; Sevillano Castano, M. L.; Escolano Segovia, O.; Garcia Frutos, F. J.

    2009-05-21

    An evaluation of analytical parameters to determine selected PAHs in a fuel oil type II by HPLC coupled to fluorescence and diode detectors is presented. The study was focused on four conventional treatments of these kinds of oil samples and the main objective was giving a measure of confidence level of PAH results in the fuel oil. This study was performed in the frame of the project Assessment of natural attenuation of PAHs in agricultural soil contaminated with fuel from an accidental spill (Spanish National Plain I+D+I, CTM2007-64537). This paper is presented as follows: Analysis of reference material 1582 (NIST) by using the four kinds of sample treatments of interest. Application of variance analysis to compare results obtained from type II fuel by using each sample treatment and chromatographic detector. Finally, a statistic calculation was performed to measure uncertainty components in chromatographic analysis. (Author)

  13. 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)

  14. Determination of concentration of radon, volatile organic compounds (VOC) and water chemistry in springs near to Popocatepetl volcano; Determinacion de la concentracion de radon, VOCs y Quimica del agua en manantiales cercanos al volcan Popocatepetl

    Energy Technology Data Exchange (ETDEWEB)

    Pena, P.; Segovia, N.; Lopez M, B.E.; Cisniega, G. [ININ, A.P. 18-1027, 11801 Mexico D.F. (Mexico); Valdes, C.; Armienta, M.A.; Mena, M. [Instituto de Geofisica, UNAM, 04510 Mexico D.F. (Mexico)

    2004-07-01

    Popocatepetl volcano is a high-risk active volcano in Central Mexico where the highest population density in the country is settled. Radon in the soil and groundwater together with water chemistry from samples of nearby springs is analysed as a function of the 2002-2003 volcanic activity. Soil radon indicated fluctuations related both the meteorological parameters and sporadic explosive events. Groundwater radon showed essentially differences in concentration due to the specific characteristics of the studied springs. Water chemistry showed stability along the monitoring period indicating also differences between springs. No anthropogenic pollution from volatile organic compounds was observed. (Author)

  15. Determination of the solid consumption in the transport of sands in sea beds with gold 198; Determinacion del gasto solido en el transporte de arenas en lechos marinos con oro 198

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez A, G

    1983-07-01

    The study of the movement of sediments in sea beds, is necessary when one plans to build a port. Among the techniques used for this studies, it is the radiotracer balance that gives an useful estimation of the quantity of sediment that it moves per day and by meter (perpendicular to the displacement). The main objectives of this work are: to) to present the characteristics of the obtaining of the used radiotracer, describing details those used safety measures, b) to describe the handling of the radiotracer and it radiological safety, during the transport and injection in the sea bottom, c) description of the detection way and the used equipment, d) to describe the information processing obtained in the field and finally, e) the estimate of the solid consumption and the determination of the direction and speed of displacement of those sediments in the sea bottom, in front of the Tabasco coast, to be used jointly with the information obtained by means of other techniques so that one can make a good planning of the operations of dredging during the construction and later on the maintenance of the Dos Bocas marine terminal. The first step is to obtain the radiotracer that in this case was sand of uniform grain metric, marked superficially with Gold-198. The second step is to transport the sand to the place of interest, to place it in the injection equipment and to deposit it in the sea bottom. The third step is to detect the radiotracer in the sea bed, from a craft that drags a sled, which takes mounted a scintillation detector of sodium iodide activated with thallium NaI(Tl) (probe). The fourth step is to process the field information and to obtain the corresponding results. (Author)

  16. Determination of {sup 222}Rn and its physico-chemical and biological characteristics in aquifers of Toluca valley; Determinacion de {sup 222}Rn y caracteristicas fisicoquimicas y biologicas en acuiferos del Valle de Toluca

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez, A.; Aranda, P.; Ceballos, S.; Cruz, D.; Jauregui, B.; Lopez, R.; Pena, P.; Salazar, S.; Segovia, N.; Tamez, E. [Instituto nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    1997-07-01

    In this work it is realized a geochemical study which includes the evaluation of {sup 222} Rn concentration in drinking water wells at Toluca city and a spring water of Almoloya de Juarez municipality at State of mexico. the same is studied about evolution of {sup 222} Rn concentration in water of the hydrating which supply it to those wells. the geochemical evaluation also covers the determination of major and minor elements or trace and the biological analysis of water. The study includes two seasonal cycles, the low water mark one and other the rainy for being able to evaluate the aquifers reloading effects in the water composition. (Author)

  17. Determination of dissolved oxygen in saline waters applying mathematical methods and as a membrane electrode sensor; Determinacion de oxigeno disuelto en aguas salinas aplicando modelos matematicos y como sensor electrodo de membrana

    Energy Technology Data Exchange (ETDEWEB)

    Mayari, R.; Espinosa, M. C.; Ruiz, M. [Centro Nacional de Investigaciones Ceintificas. La Habana (Cuba); Romero, E. [Universidad de Huelva (Spain)

    2000-07-01

    This work shows as specific methodology for the determination of dissolved oxygen in saline waters that allows to consider the variations of temperature and of concentration of salts. Both factors influence the solubility of the gases in water, making possible in place measurements, in bodies of water with content of salts unto of the concentration of sea water, with greater dependability. The mathematical models obtained are shown, the errors due to equipment, as well as the results obtained when applying this methodology in saline waters with diverse levels of contamination this allows to discern when the decrease of dissolved oxygen levels is due to an increase in the salinity or to an increase in the contamination of the water body. (Author) 7 refs.

  18. Application of digital image processing to determine the causes of failures in SAE 1018 carbon steel; Aplicacion del procesamiento digital de imagenes para la determinacion de las causas que provocan fallas en el acero al carbono SAE 1018

    Energy Technology Data Exchange (ETDEWEB)

    Bolanos-Rodriguez, E [Escuela Superior de Tizayuca, Universidad Autonoma del Estado de Hidalgo, Tizayuca, Hidalgo (Mexico)]. E-mail: bola7112@yahoo.com.mx; Gonzalez-Islas, J.C. [Universidad Tecnologica de Tulancingo, Tulancingo, Hidalgo (Mexico)]. E-mail: juanc.gonzalez@utec-tgo.edu.mx; Felipe-Riveron, E.M. [Centro de Investigacion en Computacion, Instituto Politecnico Nacional, Mexico, D.F. (Mexico)]. E-mail: edgardo@cic.ipn.mx

    2013-03-15

    The research is focused on determining the causes of failures in the SAE 1018 carbon steel that is used in pipes carrying drinking water. Digital processing of images captured by photomicrographs by scanning electron microscopy coupled with the technique of X-ray microanalysis. The results demonstrate that the low quality of the raw materials and the manufacturing process of steel are the reasons for the occurrence of cracks observed in the material. [Spanish] La investigacion se centra en determinar las causas que provocan fallas en el acero al carbono SAE 1018 que es utilizado en tuberias que transportan agua potable. Se emplea el procesamiento digital de imagenes de las microfotografias captadas por medio de microscopia electronica de barrido, unido a la tecnica de microanalisis de rayos X. Los resultados obtenidos demuestran que la baja calidad de las materias primas y el proceso de manufactura del acero son las razones de la ocurrencia de fisuras observadas en el material.

  19. Determination of kinetic parameters in Tl dosemeters of LiF: Mg, Cu, P + PTFE developed in the ININ; Determinacion de parametros cineticos en dosimetros Tl de LiF: Mg, Cu, P + PTFE desarrollados en el ININ

    Energy Technology Data Exchange (ETDEWEB)

    Basurto G, B.S

    2002-07-01

    The objective of this work, is the one of determining the kinetic parameters of the dosemeter of LiF: Mg, Cu, P + Ptfe; starting from the curves Tl obtained at being irradiated with alpha radiation ({alpha}), beta ({beta}) and gamma ({gamma}). As like to compare its sensitivity with each radiation type, considering the sensitivity of the TLD-100 as the unit. In the Chapter 1, the fundamental structure of the matter is described, making emphasis in the different radiation types, and their interaction with this. In the Chapter 2, the units are described but used in the dosimetry of the radiation. In the Chapter 3, the basic concepts of the phenomenon of Tl are described and those are explained characteristic of the deconvolution method to determine the kinetics of the one phenomenon. In the Chapter 4, the methodology is detailed that was used in the elaboration of this thesis work, describing the material Tl that were considered like reference, as well as the sources of ionizing radiation, with those that the dosemeters were irradiated and the equipment in the one that the curves Tl was obtained. Reference is made to the software used to carry out the deconvolution of the curves Tl that were obtained in the one experimental development. In the Chapter 5, the obtained results of this study are presented, showing the tables of homogenization of dosemeters and the reading of the same one; they are observed the curves Tl obtained to different radiation doses (alpha, beta and gamma), the intensity Tl in function of the dose. Also they are tabulated, the obtained results in the kinetic parameters of the three different study materials (TLD-100H, USA; TLD-100, USA and LiF: Mg, Cu, P + Ptfe developed in the l.N.l.N). They are analyzed shortly for each material Tl their sensitivity to the ionizing radiation as well as their kinetic parameters. The obtained results showed that the Tl dosemeters of LiF: Mg,Cu,P + Ptfe, they presented a bigger sensitivity that the TLD-100 when being irradiated with gamma radiation of {sup 60} Co, in air. While when being irradiated with the same type of radiation, but in phantom of water, their sensitivity was lightly smaller. To the being irradiated with beta radiation of {sup 90} Sr, the relative sensitivity diminished and it was considerably smaller when being irradiated with alpha radiation of {sup 244} Cm. (Author)

  20. Determination of bitumen and rubber content in bituminous mixes containing crumb tyre rubber; Determinacion del contenido de betum y de caucho en las mezclas bituminosas que incorporan plvo de caucho procedente de neumaticos fuera de uso

    Energy Technology Data Exchange (ETDEWEB)

    Rubio Guzamn, B.; Jimenez Saez, R.

    2009-07-01

    In recent years the use of crumb rubber from scrap tyres as a component of hot bituminous mixes for road construction, has been officially promoted by the Public Administration in Spain, by issuing several publications of both informative and normative nature, aimed to spread knowledge and experiences on the subject and also to specify the requirement and regulate the working applications for this material. However, it also seems necessary to develop new test methods which, allows control of the rubber content in crumb rubber-added mixes, regardless of the process (wet or dry) followed for the mix production. This article describes a procedure reliable enough to determine both the soluble bituminous binder and the rubber contents in bituminous mixes based on two combined, previously standardized test methods: binder extraction with solvent and ignition. (Author) 7 refs.

  1. Determination of mercury in urine through Neutron activation analysis in dentists, as a measure of occupational exposure; Determinacion de mercurio en orina mediante analisis por activacion neutronica en odontologos, como una medida de exposicion ocupacional

    Energy Technology Data Exchange (ETDEWEB)

    Padilla M, M.A

    2000-07-01

    The mercury level was studied in urine to a dentists group belonging at the Universidad Autonoma del Estado de Mexico to determine the grade of contamination to the exposure of this element during their occupational activity. It was used the Neutron activation analysis which is an analytical method based in the irradiation with neutrons toward a stable nuclide. This can suffer a nuclear transformation to produce a radioactive nuclide and so it will be able to realize a quantitative analysis of itself. The TRIGA Mark III Reactor at the Nuclear Center in Mexico was used to realize this type of analysis due to the neutron fluxes which can be obtained as well as to the facilities in the irradiation of the sample.The purpose of this work is to determine the concentrations of mercury in the occupational exposed personnel such as dentists and so giving the recommendations of safety required to their production. (Author)

  2. Natural radioactivity levels and danger ratio in cements, concretes and mortars used in construction; Determinacion de niveles radiactivos naturales e indices de peligrosidad en cementos, hormigones y morteros utilizados en construccion

    Energy Technology Data Exchange (ETDEWEB)

    Meneses, J.; Pacheco, C.; Avila, J. M.; Miro, C.

    2010-07-01

    We have determined the natural radiation level in three types of adhesive cements, five types of concrete and two types of mortars of different strength normally used in the construction field. Of these materials, both concrete and mortars were prepared in our laboratories, cements the contrary were of a commercial nature.

  3. Determination of nitrogen in wheat flour through Activation analysis using Fast neutron flux of a Thermal nuclear reactor; Determinacion de nitrogeno en harina de trigo mediante analisis por activacion empleando el flujo de neutrones rapidos de un reactor nuclear termico

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez G, T

    1976-07-01

    In this work is done a technical study for determining Nitrogen (protein) and other elements in wheat flour Activation analysis, with Fast neutrons from a Thermal nuclear reactor. Initially it is given an introduction about the basic principles of the methods of analysis. Equipment used in Activation analysis and a brief description of the neutron source (Thermal nuclear reactor). The realized experiments for determining the flux form in the irradiation site, the half life of N-13 and the interferences due to the sample composition are included too. Finally, the obtained results by Activation and the Kjeldahl method are tabulated. (Author)

  4. Determination of rubidium and strontium in geological materials by X-Ray fluorescence spectrometry; Determinacion de rubidio y estroncio en materiales geologicos mediante espectrometria de fluorescencia de rayos X

    Energy Technology Data Exchange (ETDEWEB)

    Roca, M.

    1979-07-01

    In order to determine whole-rock ages by the Rb/Sr procedure, an X-ray fluorescence spectrometry method for the determination of both elements has been developed. The samples are pressed into boric acid backed and ringed pellets with this material as a binding agent. Matrix corrections are made following the determination od the mass absorption coefficients, based on the intensity of the Compton-scattered peak of MoK{alpha}. or MoK{beta}{sub 1}.3. The U. S. Geological Survey granodiorite GSP-1 is used as a reference standard. Spectral-line interferences have been carefully studied and the empirical correction factors determined. A BASIC language program for calculating the Rb and Sr concentrations and the Rb/Sr ratios has been written. (Author) 7 refs.

  5. The use of halogen carriers and buffers in the spectrographic determination of boron in carbonaceous materials and their combustion products; Empleo de agentes halogenantes y reguladores en la determinacion espectrografica de Boro en carbones y productos derivados

    Energy Technology Data Exchange (ETDEWEB)

    Rucandio, M. I.; Martin, M.; Roca, M.

    1992-07-01

    For the determination of boron in carbonaceous materials (high purity graphite, coals and their processed products, such as ashes and slags from thermoelectric power plants) by atomic emission spectroscopy with direct current are excitation and photographic recording, the behaviour of the analyte in the presence of halide compounds or spectrochemical buffers has been studied. Among the halides, cupric fluoride at a low concentration (2%) becomes very suitable for the graphite analysis, and at a higher concentration (25 %) for coals, being necessary in this case to carry out a dilution of samples with graphite. Strontium carbonate as a spectrochemical buffer allows to analyse satisfactorily coals and their combustion products. (Author) 13 refs.

  6. Determination of mean molecular weights in organic reactor coolants. III. Differential cryoscopy with thermoelectric thermometer; Determinacion de masas moleculares medias en refrigerantes nucleares organicos. III-Crioscopia diferencial con termometro termoelectrico

    Energy Technology Data Exchange (ETDEWEB)

    Becerro, E.; Carreira, M.

    1968-07-01

    The solubility problems raised by some components of the polymeric residue of irradiated polyphenolic coolants, which make it necessary to operate with very small samples, have been solved by means of a differential cryoscopic technique using a thermoelectric thermometer (thermal) as sensitive element. The method is based on the direct measurement of the difference between the freezing points of the investigated solution and of a reference solution whose concentration may be changed at will. The change of {delta} V (mV) versus c(molal) is linear, the equivalent point being determined either analytically or graphically depending on the required accuracy. The method has been tested by measurements on pure polyphenyls, using diphenyl ether as solvent. It has been also applied to the main prospective coolants for the DON reactor. Working with 10{sup 2} molal solutions the accuracy is better than {+-} 2 per cent. (Author) 2 refs.

  7. Determination of average molecular weights on organic reactor coolants. II.-Freezing point depression method for diphenyl-ether solutions; Determinacion de masas moleculares medias en refrigerantes nucleares organicos. II.- Crioscopia de disoluciones en eter difenilico

    Energy Technology Data Exchange (ETDEWEB)

    Carreira, M.

    1965-07-01

    In order to reduce limitations of solubility, the cryoscopic method developed for benzene solutions of polyphenyl mixtures has been extended to diphenyl-ether solutions by introducing some modifications imposed by the physico-chemical properties of this solvent. The Nernsto theory of Beckman's method has been revised, taking into account the heat-transfer characteristics of the system, and the results of that analysis have been used to fix upon the design parameters of a cryoscopic apparatus for measurements on diphenyl-ether solutions. (Author) 9 refs.

  8. Contribution to the spectrographic determination of impurities in uranium by the carrier distillation method; Nuevas aportaciones a la determinacion espectrografica de impurezas en materiales de uranio por el metodo de distilacion fraccionada con portador

    Energy Technology Data Exchange (ETDEWEB)

    Capdevila, C.

    1967-07-01

    The carrier distillation method for the determination of impurities in uranium has been modified in order to get a greater sensitivity. Electrodes 9.5 mm. diam. with a crater 7 mm. diam. and 10 mm. deep have been used, being the weigh of charge 300 mg.. The elements considered were: Al, As, B, Ca, Cd, Co, Cr, Cu, Fe, Mg, Mn, Mo, Ni, P, Pb, Si, Sn, Ti and V, over the range 0.01 to 30 ppm. (Author) 13 refs.

  9. Separation of oily materials in radioactive waste waters by flotation. Determination of operation and control parameters; Separacion de materiales oleosos en aguas residuales radiactivas por flotacion. Determinacion de parametros de operacion y control

    Energy Technology Data Exchange (ETDEWEB)

    Ortiz O, H.B.; Flores E, R.M. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)]. e-mail: huemantzin@prodigy.net.mx

    2003-07-01

    In this work the determination of the operation and control parameters (air/solids ratio G/S, retention time {theta}, pressure P and de pressurized volume of mixed air-water V), of the flotation system used in the treatment of oleaginous residual water (polluted mainly with {sup 60} Co) coming from the decontamination process of worn out oils, using as response parameters the concentration of oleaginous material and the residual turbidity. The obtained results allowed to observe the dependence of G/S with the pressure and volume of air-water given. At the same time it was settled down that the set of operation conditions that offers the greater separation percentage of G As and turbidity in the smallest time, they are those obtained by V{sub 2} = 0.0012 m{sup 3} and P{sub 2} = 620 kPa, (G/S = 0.30 - 0.35, = 14-16 min) for what were employees as the ideal values of operation and control in the flotation system. As long as, the concentration of total Co is found under 1 mgL{sup -1}. Finally, the selected flotation system showed high separation levels of {sup 60} Co, whose specific activity are below of 0.007 BqmL{sup -1}. (Author)

  10. Determination of the neutron spectra in the treatment room of a linear accelerator for radiotherapy; Determinacion de los espectros de neutrones en la sala de tratamiento de un acelerador lineal para radioterapia

    Energy Technology Data Exchange (ETDEWEB)

    Vega C, H.R. [Universidad Autonoma de Zacatecas, Cuerpo Academico de Radiobiologia, A.P. 336, 98000 Zacatecas (Mexico); Barquero, R. [Hospital Universitario Rio Hortega, Valladolid (Spain); Mendez, R.; Iniguez, M.P. [Depto. de Fisica Teorica, Atomica, Molecular y Nuclear, Universidad de Valladolid, 47011 Valladolid (Spain)

    2003-07-01

    By means of a series of measures and Monte Carlo calculations the dosimetric characteristics of the photoneutrons have been determined that take place in volume to a linear accelerator of radiotherapy of 18 MV, LINAC, mark Siemens Mevatron model. The measures were carried out with thermoluminescent dosemeters TLD 600 and TLD 700 that were naked exposed and confined with cover of Cd and Sn, inside a sphere of paraffin and inside spheres Bonner. (Author)

  11. Transmission of Helicobacter pylori via water for human consumption. Determination by means of the molecular method using PCR; Helicobacter pylori, su transmision a traves de las aguas para el consumo humano. Determinacion por metodo molecular con la PCR

    Energy Technology Data Exchange (ETDEWEB)

    Amo, A. J.; Moreno, C.; Apraiz, D.; Catalan, V. [LABAQUA. Alicante (Spain)

    1998-12-31

    Helicobacter pylori is the cause of chronic gastritis, duodenal ulcers and stomach cancer. Its natural reservoirs and transmission mechanisms are still little understood. The gastro-oral route-especially vomiting and regurgitation-is one transmission path, especially in young children and babies. It has been found in some patients saliva and dental plaque, which suggests a possible oral-oral contagion route. The discovery of H. Pylori human excrement points to a faecal-oral route as the main transmission pathway via water for human consumption. It is therefore important to develop detection methods such as isolation by culture and polymerase chain reaction (PCR) to effectively monitor this pathogen in human drinking water. (Author) 30 refs.

  12. An X-ray fluorescence method for the determination of small quantities el elements collected on filters; Determinacion de pequenas concentraciones de elementos en filtros por espectrometria de fluorescencia de rayos X

    Energy Technology Data Exchange (ETDEWEB)

    Diaz-Guerra, J. P.; Bayon, A.

    1981-07-01

    An X-ray fluorescence method for the determination of As, Ba, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Se, U, V and Zn collected on P.V.C. filters in concentration ranges from 0,6 to 1000{mu}g, depending on the element, is described. A sequential automatic spectrometer with a chromium tube is used for tho Ba determination, while As, Hg, Pb, Se and U are bottler determined with a molybdenum one. For the rest of the elements a tungsten target is preferred. The interferences between AsK{sup {alpha}}{sub 1},2- PbL{sup {alpha}}{sub 1},2 and CrK{sup {alpha}}{sub 1},2-Vk{beta}{sub 1},3 lines are corrected by applying specific coefficients. The radial variation of the primary X-ray beam intensity on the irradiated surface has been specially studied with chromium, gold, molybdenum and tungsten tubes. For that purpose different x-ray wavelengths in the range 9,89 A to 0,56 A have been selected. The curves obtained show a rather high heterogeneity for the excitation source. This conclusion implies the need for an homogeneous distribution of elements on the filter. (Author) 7 refs.

  13. Determination of the detection efficiency of a HPGe detector by means of the MCNP 4A simulation code; Determinacion de la eficiencia de deteccion de un detector HPGe mediante el codigo de simulacion MCNP 4A

    Energy Technology Data Exchange (ETDEWEB)

    Leal, B. [Centro Regional de Estudios Nucleares, A.P. 579C, 98068 Zacatecas (Mexico)

    2004-07-01

    In the majority of the laboratories, the calibration in efficiency of the detector is carried out by means of the standard sources measurement of gamma photons that have a determined activity, or for matrices that contain a variety of radionuclides that can embrace the energy range of interest. Given the experimental importance that has the determination from the curves of efficiency to the effects of establishing the quantitative results, is appealed to the simulation of the response function of the detector used in the Regional Center of Nuclear Studies inside the energy range of 80 keV to 1400 keV varying the density of the matrix, by means of the application of the Monte Carlo code MCNP-4A. The adjustment obtained shows an acceptance grade in the range of 100 to 600 keV, with a smaller percentage discrepancy to 5%. (Author)

  14. {sup 222} Rn determination and physicochemical characteristic and biological in aquifers in the Toluca Valley; Determinacion de {sup 222} Rn y caracteristicas fisicoquimicas y biologicas en acuiferos del Valle de Toluca

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez A, A

    1998-10-01

    Concentration levels of {sup 222} Rn and {sup 226} Rn have been analyzed in water samples from boreholes belonging to the drinking water supply system around Toluca, Mexico. The {sup 222} Rn source is the decay of {sup 226} Rn within the solid matrix of the aquifer. The study was performed during the dry and rainy seasons. {sup 222} Rn concentration was determined by the liquid scintillation technique, {sup 226} Rn was determined by gamma spectrometry, the physicochemical parameters and bacteriological analysis were performed by conventional chemical techniques. Solubilized trace elements were determined by Inductively Coupled Plasma - Mass Spectrometry (Icp-Ms). The radon level fluctuations at the boreholes in Toluca city and Almoloya spring indicated differences in the radon content. At borehole Lodos Prietos 2, the temperature and radon level were systematically the highest in comparison with the other boreholes and the spring indicating a contribution of a regional flow to the water of this particular borehole. The result for {sup 226} Rn, the average {sup 222} Rn observed during the sampling period, no correspondence occurs between the radium and the radon content indicating that, radon is not supported by radium, but is incorporated into the water through fissures in the rocks in contact with the water. The radon levels obtained in house faucets which water is supplied by boreholes decrease as a function of the distance from the source borehole to the house. With the chemical composition of each one of the studied boreholes and spring a Piper diagram was draw indicating the kind of water. The boreholes and spring can be classified as bicarbonate calcium/magnesium. Almost no fluctuation on time was observed in the chemical species and trace elements only a slight increase was observed at the end of the rain season. At Almoloya, spring pollution with coliform bacteria and nitrates showed an anthropogenic contribution to the water deterioration probable and fertilizers and detritus. Most of the studied water samples were potable, however at Lodos Prietos 2 borehole the fluorine concentration was higher than the established norm. (Author)

  15. The radioactive equilibrium and determination methods for ratio e Ra/U; Desequilibrio Radiactivos-1. Metodo {sub {beta}}-{gamma}. Determinacion de la razon eRa/U. Valoracion del contenido en U{sub 3}O{sub 8}

    Energy Technology Data Exchange (ETDEWEB)

    Mingarro, E.

    1966-07-01

    The main problems concerning the radioactive non-equilibrium on minerals and a simultaneous counting procedure for {beta}- and {gamma}- activities developed to solve those problems, are described. (Author)

  16. Determination of interplanar distances starting from diffraction spectra for the Cyber computer of the ININ; Determinacion de distancias interplanares a partir de espectros de difraccion para la computadora Cyber del ININ

    Energy Technology Data Exchange (ETDEWEB)

    Macias B, L.R

    1991-04-15

    To identify a compound by means of diffraction it is required to obtain it spectrum or diffractogram that it is not more than a graphic I/I{sub o} vs. 2 {theta}. Since this analysis type is carried out on samples of glasses, it is expected that when impacting the radiation on the sample and to vary the angles {theta} and 2 {theta}, and when being completed the Bragg law, constructive interference it exists among all the radiation beams that emerge of the sample and take place the diffraction. In this work the diffractogram is identified by means of a graph equipment (x,t) that directly obtains the graphic I/I{sub o} vs. 2 {theta} and in this it has to be carried out angular measurement of the present peaks and later on with the data 2 {theta}{sub i} it was proceeds to compare with the totally identified patterns as the contents in the Powder Diffraction File of the Joint Committee on Powder Diffraction Standards (JCPDS). (Author)

  17. Using Bromocresol Purple to Determine Fecal Coliforms with the Most Probable Number Technique; Utilizacion de purpura de bromocresol para la determinacion de coliformes fecales con la tecnica del numero mas probable (NMP)

    Energy Technology Data Exchange (ETDEWEB)

    Vazquez Borges, E.; Mendez Novelo, R.

    2003-07-01

    The object of this piece of research was to determine the reliability of using bromocresol purple as an indicator for determining fecal coliforms by means of the most probable number (MPN) technique using multiple tubes and comparing the results obtained in this way with those obtained using the traditional technique of the formation of carbon dioxide in a Durham tube. Twelve samples of different types of water were analysed using sets of nine tubes, one with a Durham tube and another with the addition of bromocresol purple. In the former case, a reaction was jadged as positive (indicating the presence of coliforms) if CO{sub 2} was formed in the Durham tube. In the latter case, the reaction was considered as positive if a change in colour-from purple to yellow-of the culture medium was observed. A statistical analysis was performed to determine the significant differences in the sensitivity and specificity of both methods. (Author)

  18. Determination of patterns of interplanar distances starting from crystalline parameters for the Cyber computer of the ININ; Determinacion de patrones de distancias interplanares a partir de parametros cristalinos para la computadora Cyber del ININ

    Energy Technology Data Exchange (ETDEWEB)

    Macias B, L.R

    1991-03-15

    In this report a program in Fortran language that reproduces the pattern of the Joint Committee on Powder Diffraction Standards is presented and that it can be applied to identify non well-known samples such as in those that only by means of articles or other sources the values of the parameters of the elementary cell are lightly known and by this way the correspondent diffraction pattern can be accurately generated. (Author)

  19. Determination of lead in clay enameled by X-ray fluorescence technique in Total reflection and by Scanning Electron Microscopy; Determinacion de plomo en esmaltado de barro por Fluorescencia de rayos X en reflexion total y Microscopia Electronica de Barrido

    Energy Technology Data Exchange (ETDEWEB)

    Zarazua O, G.; Carapia M, L. [Instituto Nacional de Investigaciones Nucleares, C.P. 52045 Estado de Mexico (Mexico)

    2000-07-01

    This work has the objective of determining lead free in the glazed commercial stewing pans using the X-ray fluorescence technique in Total reflection (FRX) and the observation and semiquantitative determination of lead by Analytical Scanning Electron Microscopy (ASEM). (Author)

  20. Application of the methodology of surface of answer in the determination of the PCT in the simulation of a LOFT; Aplicacion de la metodologia de superficies de respuesta en la determinacion del PCT en la simulacion de un LOFT

    Energy Technology Data Exchange (ETDEWEB)

    Alva N, J. [IPN, Escuela Superior de Fisica y Matematicas, Departamento de Ingenieria Nuclear, Av. IPN s/n, Col. Lindavista, Mexico 07738 D.F. (Mexico); Ortiz V, J.; Amador G, R. [ININ, 52750 La Marquesa, Estado de Mexico (Mexico)]. e-mail: neriaesfm@gmail.com

    2008-07-01

    This article summarizes the main typical of the methodology of surfaces and answer (MSA) and its connections with the lineal regression analysis. Also, an example of the application of MSA in the prediction of the principle cladding temperature (PCT) of a combustible assembly of a nuclear reactor, whose used data were taken from the simulation of a LOFT (Loss Of Fluid Test) during a course of experts. The made prediction will be used like one first approach to predict the behavior of the PCT, this is made in order to diminish the time of calculation when realizing the executions of codes thermal hydraulics of better estimation. The present work comprises of the theoretical base of the project in charge to delineate a methodology of uncertainty analysis for codes of better estimation, employees in the thermal hydraulics analysis and safety of plants and nuclear reactors. The institutions that participate in such project are: ININ, CFE, IPN and CNSNS, is possible to mention that this project is sponsored by the IAEA. (Author)

  1. Determination of the global daily radiation the value during the day; Determinacion de la irradiacion global diaria a partir de un minimo de valores de la irradiancia a lo largo del dia

    Energy Technology Data Exchange (ETDEWEB)

    Vazquez, M.; Fernandes, F.; Santos, J.; Prado, T.

    2004-07-01

    This paper is about the minimum number of solar irradiance values distributed along a day that lets to estimate the daily solar irradiation with an acceptable margin of error. The final objective of the study is to use the irradiance calculated from Meteosat images for obtaining solar radiation maps. The data base utilised is the radiance (minute radiation) and daily irradiation data base from the meteo-radiometric station of the University of Vigo Solar Lab for the years 2002 and 2003. Acceptable results are found with three values of the irradiance covering the six central hours of the day. In this case it is proposed a second order equation as the optimal regression adjustment. It is found also that it is not necessary to use more than five irradiance values covering the ten central hours of the day given that the optimal lineal regression adjustment is lineal, that is the proposed. (Author)

  2. Determination of activity by gamma spectrometry of radionuclides present in drums of residues generated in nuclear centrals; Determinacion de actividad por espectrometria gamma de radionucleidos presentes en tambores de residuos generados en centrales nucleares

    Energy Technology Data Exchange (ETDEWEB)

    Aguiar, J.C.; Fernandez, J. [Autoridad Regulatoria Nuclear, Av. Del Libertador 8250, Ciudad Autonoma de Buenos Aires (Argentina)]. e-mail: jaguiar@cae.arn.gov.ar

    2006-07-01

    The generation of radioactive residuals in nuclear centrals as CNA I (Atucha I Nuclear Central) and CNE (Embalse Nuclear Central) makes that the measurement of those radionuclides has been a previous stage to the waste management. A method used in those nuclear centrals it is the gamma spectrometry with HPGe detectors, previous to the immobilization of the residual in a cemented matrix, with this the contact with the external agents and its possible dispersion to the atmosphere in the short term is avoided. The ARN (Nuclear Regulatory Authority) of Argentina it carries out periodically intercomparisons and evaluations of the measurement and procedures systems used in the nuclear power stations for the correct measurement and determination of activity of radioactive residuals by gamma spectrometry. In this work an independent method of measurement is exposed to the nuclear power stations. To determine the activity of the residuals by gamma spectrometry deposited in drums, it is required of the precise knowledge of the efficiency curve for such geometry and matrix. Due to the RNA doesn't have a pattern of these characteristics, a mathematical model has been used to obtain this efficiency curve. For it, it is necessary to determine previously: 1) the geometric efficiency or solid angle sustained by the source-detector system (drum-detector) applying a mathematical model described in this work. 2) To estimate the auto-attenuation factor that present the photons in the cemented matrix, these calculations are carried out with a simple equation and its are verified with the Micro Shield 6.10 program. The container commonly used by these nuclear power stations its are drums for 220 liters constructed with SAE 1010 steel and with a thickness of 0.127 cm, with an approximate weight 7.73 Kg., internal diameter of 57.1 cm, and height: 87 cm. The results obtained until the moment register a discrepancy from 5 to 10% with relationship to the measurements carried out by the nuclear power stations. (Author)

  3. Determination of the radon concentration in soil and ground water and its association with the seismicity; Determinacion de la concentracion del radon en suelo y agua subterranea y su asociacion con la sismicidad

    Energy Technology Data Exchange (ETDEWEB)

    Pena, P.; Segovia, N. [ININ, A.P. 18-1027, 11801 Mexico D.F. (Mexico); Azorin, J. [UAM-I, 09340 Mexico D.F. (Mexico)

    2003-07-01

    The coast of the Mexican Pacific is one of the seismic areas more active of the world due to the subduction of the badges of Coconuts and Rivera under the badge of North America. The earthquakes that happen in this part of Mexico they are of great magnitude and they affect to the central plateau of the country where finds the biggest population density. On the other hand the coast of the Gulf of Mexico presents one relatively low seismic activity. It is in this region where it is the nuclear plant of Laguna Verde (PNLV) and the studies of seismicity of the area should be carried out for questions of nuclear security. One carries out a study of fluctuations of the concentration of the radon in floor and it dilutes underground in the mentioned areas using accustomed to detectors of nuclear appearances (LR-115). Possibly they were also used detecting automatic (Clipperton sounds out). In some cases it was analysed the gamma radiation in soil using thermoluminescent dosemeters (CaSO{sub 4}: Dy + Ptfe). The mineralogical composition of rock samples was obtained, by means of technical conventional and Electron scanning microscopy and an X-ray diffractometer. The study one carries out along the coast of Guerrero, from Guacamayas, Mich. until Marquelia, Gro., of 1993 at 1998 and in the coast of the Gulf of Mexico, in the PNLV and their surroundings, of 1994 at 1996. The fluctuations of the radon concentration and of the gamma radiation, were analysed in function of the local seismic activity, the meteorological parameters and those characteristic geologic. In the area of the PNLV, the results showed that in general the averages of those value of the radon concentration, as much in floor as in water, they were low. A station located in a flaw area (New Ranch) the one that I present the values was but high of radon concentration, corresponding those but first floor to the PNLV. The seismic activity during the one period of sampling was sporadic and of low intensity and alone one could observe that the flaw area the one that had values bigger than the radon concentration was. Some variations of the concentration of the radon could be correlated with the meteorological parameters and those characteristic geologic. The anomalies of the values of the concentration of the radon were presented in general during the rainy season. In the coast of the Pacific one observes an intense seismic activity (M>4) in the period of sampling. The concentration of the radon in floor measured in long periods of time didn't respond with picks one to one to the local earthquakes, but it showed a global increase in an area of high seismic activity. The variations of the radon concentration and of the radiation gamma they showed a strong correlation among if. The differences in the composition of the rocks were reflected in you differ so much in the radon emanation like in the levels of radiation gamma in the area studied. The fluctuations of the concentration of the radon in floor showed occasionally dependence with the meteorological parameters, the same as in the area of the Gulf, the maximum values were obtained mainly in the rainy season. (Author)

  4. Determination of the dose rate to the center of the irradiation chamber of the Gamma cell 220 AECL; Determinacion de la razon de dosis al centro de la camara de irradiacion del Gammacell 220 AECL

    Energy Technology Data Exchange (ETDEWEB)

    Zuazua G, M.P

    1991-11-15

    To determine the dose rate at the center of the irradiation chamber of the Gamma cell 220 AECL, two different spectrophotometers for to measure the absorbency of the irradiated dosemeters were used. In the first one dosimetry, the absorbency of the irradiated Fricke solution was read in the Varian-UV-visible spectrophotometer Series 634 of the Applied Research Management. For the second dosimetry it was used the Shimadzu UV-visible spectrophotometer belonging to the Special Projects Department. The obtained results in this study are presented. (Author)

  5. Simultaneous determination of Ra-226, natural uranium and natural thorium by gamma-ray spectrometry INa(Ti), in solid samples.; Determinacion de U (Natural), Th (Natural) y Ra-226 en diversos materiales, mediante espectrometria con INa (TI)

    Energy Technology Data Exchange (ETDEWEB)

    Salvador, S.; Navarro, T.; Alvarez, A.

    1991-07-01

    A method has been developed to determine activities of Ra-226, natural uranium and natural thorium by gamma-ray spectrometry. The measurement system has been calibrated using standards specially prepared at the laboratory. It is necessary to assume secular equilibrium in the samples, between Ra-226 and Th-232 and its daughters nuclides, and between U-238 and its immediate daughter Th-234, as the photo peaks measured are those of the daughters. The results obtained indicate that this method can of ter replace the radiochemical techniques used to measure activities in this type of sample. The method has been successfully used to determine these natural isotopes in samples from uranium mills. (Author) 9 refs.

  6. Determination of Carbon-14 in environmental samples by mixing 14CO{sub 2} with a liquid scintillator; Determinacion de carbono-14 en muestras ambientales por incorporacion de 14CO{sub 2} a un centelleador liquido

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, M. R.; Gomez, V.; Heras, M. C.; Beltran, M. A.

    1990-07-01

    A method for the determination of Carbon-14 (14CO2) in environmental samples has been developed. The method use the direct absorption of the carbon dioxide into Carbosorb, followed with incorporation of the mixture (Carbosorb-CO2) to the liquid scintillator. The results obtained to apply this method and the benzene synthesis, usual in our laboratory, are discussed and compared. The method of collection of atmospheric samples is also described. (Author) 10 refs.

  7. Analysis of polycyclic aromatic hydrocarbons I. Determination by gas chromatography with glass and fused silica capillary columns; Analisis de Hidrocarburos aromaticos policiclicos. I. Determinacion por cromatografia de gases con columnas capilares de vidrio de silice fundida

    Energy Technology Data Exchange (ETDEWEB)

    Perez, M. M.; Gonzalez, D.

    1987-07-01

    A study of the analysis by gas chromatography of aromatic polycyclic hydrocarbons is presented. The separation has been carried out by glass and fused silica capillary column. The limitations and the advantages of the procedure are discussed in terms of separation efficiency, sensitivity and precision. (Author) 17 refs.

  8. Determination of the angular dependence of the detector matrix Matrix X-evolution of IBA; Determinacion de la dependencia angular del detector matricicial Matrix-X-evolution de IBA

    Energy Technology Data Exchange (ETDEWEB)

    Mateos, J. C.; Luis, F. J.; Sanchez, G.; Herrados, M.

    2011-07-01

    The objective of this work consists in determining the correction for the angular dependence of the detector-Evolution Matrix x matrix (IBA, Germany), when used in the multi cube dummy (IBA, Germany), verification of treatment VMAT IMRT, using the software OP'IMRT (IBA, Germany).

  9. Sampling procedure, receipt and conservation of water samples to determine environmental radioactivity; Procedimiento para el muestreo, recepcion y conservacion de muestras de agua para la determinacion de la radiactividad ambiental

    Energy Technology Data Exchange (ETDEWEB)

    Herranz, M.; Navarro, E.; Payeras, J. (and others)

    2009-07-01

    The present document informs about essential goals, processes and contents that the subgroups Samling and Samples Preparation and Conservation believe they should be part of the procedure to obtain a correct sampling, receipt, conservation and preparation of samples of continental, marine and waste water before qualifying its radioactive content.

  10. Analysis of a calculation method for the determination of the value of safety or control bars; Analisis de un metodo de calculo para la determinacion del valor de barras de seguridad o control

    Energy Technology Data Exchange (ETDEWEB)

    Aguilar H, F.; Torres A, C.; Filio L, C. [ININ, Gcia. de Reactores, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    1982-09-15

    Due to the control or safety bars in a nuclear reactor are constituted by strongly absorbent materials, the Diffusion Theory like tool for the calculation of bar values is not directly applicable, should it use the Transport Theory. However the speed and economy of the Diffusion codes for the reactors calculation, those make attractiveness and by this reason its are used in the determination of characteristic parameters and even in the determination of bar values, not without before to make some theoretical developments that allow to make applicable this theory. The application of the Diffusion Theory in strongly absorbent media is based on the use of some effective cross sections distinct from the real ones obtained when imposing the reason that among the flow and it gradient in the external surface of such media (control element in general, bar type or flagstone) be similar to the one obtained using Transport Theory in all the control region (multiplicative and absorbent media) with those real cross sections. The effective cross sections were obtained of the Leopard-NUMICE cell code which has incorporate the respective calculation theory of effective cross sections. Later these constants its were used in the bidimensional diffusion code Exterminator-II, simulating in it, the distribution of safety or control bars. From the cell code its were also obtained the respective constants of the homogeneous fuel cell. The results as soon as those obtained bar values of the diffusion code, its were compared with some experimental results obtained in the R{phi} Swedish reactor of natural uranium and heavy water. In this work an analysis of the bar value of one of them, trying to determine the applicability of the method is made. (Author)

  11. Determination of Zeta-potential interface in quartz-solutions non aqueous of lithium; Determinacion de potencial zeta de la interfase cuarzo-disoluciones no acuosas de cloruro de litio

    Energy Technology Data Exchange (ETDEWEB)

    Rubio-Hernandez, F.J. [Departamento Fisica AplicadaII, Universidad de Malaga (Spain)

    1995-06-01

    Electrophoretic mobility measurements of quartz particles dispersed in methanol and ethanol, with different electrolyte concentrations (LiCL) were made. Zeta-potential was calculated by using Henry`s equation. LiCL is an indifferent electrolyte for this system. Quartz does not specifically interact with both alcohols. (Author)

  12. Spectrographic Determination of Impurities in Ceramic Materials for Nuclear Fusion Reactors. I. Analysis of Alumina; Determinacion Espectrografica de impurezas en materiales ceramicos para fusion nuclear. I.- Analisis de alumina

    Energy Technology Data Exchange (ETDEWEB)

    Rucandio, M. I.; Roca, M.; Melon, A.

    1990-07-01

    The determination of minor and trace elements in the aluminium oxide considered as possible ceramic material in thermonuclear fusion reactors has been studied. The concentration ranges are 0.1 - 0.3 * for Ca, Si and Y, and at the ppm level for Co, Cr, Fe, Hf, K, Li, Mg, Mn, Na, Ni, Se, Ta, Ti, V and Zr. Atomic emission spectroscopy with direct current ore excitation and photographic detection has been employed. For Hf, Mg, Ta, Ti, V and Zr the use of 40% of copper fluoride as a carrier and of Nb as lnternal standard provide suitable sensitivities and precessions, while for the rest of elements the bent results are obtained with graphite powder in different proportions and Rb or Sn as internal standard. (Author) 7 refs.

  13. Study of granitic biotites by X-ray fluorescence analysis: determination of iron, manganese, titanium, calcium, potassium, silicon and aluminium; Estudio de biotitas graniticas por fluorescencia de rayos X: Determinacion de hierro, manganeso, titanio, calcio, potasio, silicio y aluminio

    Energy Technology Data Exchange (ETDEWEB)

    Toubes, R. O.; Bermudez Polonio, J.

    1968-07-01

    A method for the quantitative determination of iron, manganese, titanium, calcium potassium, silicon, and aluminium, is reported, Sample preparation is carried out by the miniature flux technique, and rubidium is used as internal standard for silicon and aluminium. (Author) 5 refs.

  14. Uranium Determination in Samples from Decommissioning of Nuclear facilities Related to the First Stage of Nuclear Fuel Cycle; Determinacion de Uranio en Muestras Procedentes del Desmantelamiento de Instalaciones de la Primera Parte del Cielo del Combustible Nuclear

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez, A.; Correa, E.; Navarro, N.; Sancho, C. [Ciemat, Madrid (Spain); Angeles, A.

    2000-07-01

    An adequate workplace monitoring must be carried out during the decommissioning activities, to ensure the protection of workers involved in these tasks. In addition, a large amount of waste materials are generated during the decommissioning of nuclear facilities. Clearance levels are established by regulatory authorities and are normally quite low. The determination of those activity concentration levels become more difficult when it is necessary to quantify alpha emitters such as uranium, especially when complex matrices are involved. Several methods for uranium determination in samples obtained during the decommissioning of a facility related to the first stage of the nuclear fuel cycle are presented in this work. Measurements were carried out by laboratory techniques. In situ gamma spectrometry was also used to perform measurements on site. A comparison among the different techniques was also done by analysing the results obtained in some practical applications. (Author)

  15. Determination of Cd and Pb in canned pineapple by atomic absorption spectroscopy using a graphite oven; Determinacion de Cd y Pb en pina enlatada por espectrometria de absorcion atomica utilizando horno de grafito

    Energy Technology Data Exchange (ETDEWEB)

    Linares P, G.; Sanchez P, L.; Benavides M, A.; Acosta L, C. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    1997-07-01

    Owing to the food susceptibility to be contaminated it is necessary to realize pursuit studies or frequent monitoring about the content of certain metals which represent health risks by its toxicological effects in the human being and another living organisms. In this work the cadmium and lead concentrations are determined in six national brands of canned pineapple analysing separately sugar sirup and the fruit. (Author)

  16. Determination and analysis of the physical chemical characteristics of witness coupons of boral for the CNLV; Determinacion y analisis de las caracteristicas fisico quimicas de cupones testigo de boral para la CNLV

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez M, J.L.; Aguilar H, F.; Rivero G, T.; Carrillo M, R. [ININ, Apdo. Post 18-1027, Col Escandon, 11801 Mexico D.F. (Mexico)]. E-mail: jlgm@nuclear.inin.mx; fah@nuclear.inin.mx; trg@nuclear.inin.mx; racm@nuclear.inin.mx

    2004-07-01

    The burnt fuel elements that are extracted in each charging of the Units 1 and 2 of the Nuclear Power Plant of Laguna Verde, are deposited in shelves placed in the storage reservoir designed for this end. Each cell or storage shelf has a structure type cage. Among the cells neutron absorber material is placed, (Boral), what allows to avoid the possible criticality that could settle down when accumulating in the storage the irradiated fuel elements. This boral has been designed to maintain its characteristics of thermal neutron absorber during a lifetime of the plant. To check that the wings and the Boral have not suffered some degradation or some change due to the environmental conditions in the warehouse, it is necessary to watch over their physical and chemical characteristics periodically, what is carried out by a surveillance program based on Badges or manufactured witness coupons of the same material that the wings. The badges witness are embedded in a special wing, which is placed in the place with more radiation in the pool. In this work the laboratory tests carried out in the ININ to the coupon witness 03 of the Unit 2, (II-03) are described, being presented the results and obtained conclusions. (Author)

  17. Determination of the facade potentially collecting areas in urban places by means of a computational graphic model; Determinacion del area de fachadas potencialmente colectoras, en medios urbanos, a traves de un modelo grafico computacional

    Energy Technology Data Exchange (ETDEWEB)

    Mesa, Nestor A; Cortegoso, Jose L; De rosa, Carlos [Centro Regional de Investigaciones Cientificas y Tecnnologicas (CRICYT) Mendoza (Argentina)

    2000-07-01

    In Argentina almost 30% of the total end-use energy is consumed by the building sector. Within it, for residential use, the most usual fuel is natural gas. According to a 1997 survey, the known reserves would last approximately 32 years at the present rate of consumption. It is therefore essential to asses the performance of the building stock, in relation to energy conservation and the access to renewable energy resources, in order to plan the future urban development within the scope of maximum achievable energetic and environmental sustainability compatible whit the present urban morphology. The particular features of environments within the urban system, may significantly condition the access to and the availability of climatic resources. When the technical feasibility of a specific climatic design, for a new or refurbished building is analyzed, it is necessary to asses the available solar potential and potentially collecting areas, particularly within high density urban environment, where the shadows cast by tall neighboring buildings can significantly reduce solar access. A graphic-computational model developed for the purpose is described; it is a precise and easy to use tool. Departing from the loading of the buildings volumes coordinates, of a given urban environment and the solar position it will draw axonometric perspectives as seen from the sun. It will then calculate the areas, normal to the sun beams of the radiation prisms impinging on every building facade, for any hour or day of the year. The model was developed within the environment of the AutoCADR program. [Spanish] Del total de los recursos energeticos consumidos en la Argentina casi el 30% corresponde al uso domestico, de ese total a escala residencial el mas utilizado para la calefaccion es el gas natural, contando en la actualidad, segun estudios realizados en el ano 1997, con un volumen de reserva para unos 32 anos, manteniendose la tasa de consumo actual. Esto hace imprescindible conocer el comportamiento del parque edificio, en lo referente a la conservacion de energia y el acceso a los recursos energeticos renovables, para planificar el crecimiento urbano dentro de un marco de maxima sustentabilidad energetico ambiental compatible con la actual morfologia urbana. Las particulares caracteristicas de la estructura urbana, condicionan de manera significativa el acceso y la disponibilidad de recursos climaticos. Cuando se analiza la viabilidad de un diseno bioclimatico en un edificio nuevo o en el reciclado de uno existente es necesario conocer el potencial solar disponible, ademas de las areas colectoras potenciales, sobre todo en ambitos urbanos de alta densidad, donde la incidencia de los volumenes edilicios vecinos, sobre el acceso al sol es notable. Se describe un metodo grafico computacional de alta precision y de facil manejo que, a partir de la carga de una volumetria edilicia y de los valores de posicion solar, permite obtener perspectivas axonometricas vistas desde el sol, dando como resultado, superficies de secciones normales a la direccion de los rayos solares incidentes sobre cada fachada asoleada, para cualquier hora y dia del ano. La rutina del metodo se desarrolla dentro del ambiente de programacion de AutoCAD{sup R}, por considerar que dicho entorno, es uno de los mas utilizados en el medio del diseno asistido por computadora, lo que permite obtener un resultado facilmente transferible.

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

    Energy Technology Data Exchange (ETDEWEB)

    Martin, R.; Manero, F.

    1984-07-01

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

  19. Spectrographic Determination of Impurities in Ceramic Materials for Nuclear fusion Reactors. II. Analysis of Magnesium Aluminate; Determinacion Espectrografia de Impurezas en materiales Ceramicos para Fusion Nuclear. II. Analisis de Aluminato de Magnesio

    Energy Technology Data Exchange (ETDEWEB)

    Rucandio, M. I.; Roca, M.; Melon, A.

    1990-07-01

    The determination of minor and trace elements in the magnesium aluminate, considered as possible material in thermonuclear fusion reactors, has been studied. The concentration ranges are 0.1 - 0.3 % for Ca, SI and Y, and at the ppm level for Co, Cr, Fe, Hf, K, Li, Mn, Na, Ni, Se, Ta, Ti, V and Zr. Atomic emission spectroscopy with direct current are excitation and photographic detection has been employed. For Hf, Ta and Zr the use of 40% of copper fluoride as a carrier and of Nb as internal standard provide suitable sensitivities and precessions, while for the rest of elements the best results are obtained with graphite powder in different proportions and Rb or Sn as internal standard. (Author)4 refs.

  20. Determination of the kinetic parameters of K{sub 2}Y F{sub 5}: Tb; Determinacion de los parametros cineticos de K{sub 2}Y F{sub 5}: Tb

    Energy Technology Data Exchange (ETDEWEB)

    Gallegos, A.A. [CICATA-IPN, Legaria 694, Col. Irrigacion, 11500 Mexico D.F. (Mexico); Khaidukov, N.M. [Kurnakov Institute of General and Inorganic Chemistry, Moscow (Russian Federation); Azorin, J. [UAM-I, 09340 Mexico D.F. (Mexico)

    2005-07-01

    In this work the K{sub 2}Y doped materials with percentages of 0.01 and 0.2 of F{sub 5} and, 0.8 and 0.99 of Tb{sup 3+} were studied to determine the kinetic parameters (activation energy and frequency factor) of TL peaks with the purpose of comparing those sensitive qualities of the materials at the doping with TR and their candidacy for tests of TL dosimetry (linearity of the response with the absorbed dose and the reproducibility of the measures of the dose). The samples were irradiated with a beta source of {sup 90} Sr/{sup 90} Y, to ambient temperature, giving its a dose of 236.6 mGy, later the kinetic parameters with different experimental procedures were determined: isothermal decay to ambient temperature and erased of peaks not desired to greater temperature than the ambient. The glow curves (TL curves) were obtained with an TL analyzer Harshaw 4000, with interface to CPU for the handling of the data of the curves, which were treated with the curve form method and the models of: Chen first approach and Chen modified, corrected Lushchik approach and Grossweiner approach, to calculate the kinetic parameters of the sample. (Author)

  1. Determination of the neutrons energy spectrum in the central thimble of the reactor core TRIGA Mark III; Determinacion del espectro de energia de los neutrones en el dedal central del nucleo del reactor TRIGA Mark III

    Energy Technology Data Exchange (ETDEWEB)

    Parra M, M. A.; Luis L, M. A. [Universidad Autonoma Metropolitana, Unidad Azcapotzalco, Division de Ciencias Basicas, Av. San Pablo No. 180, Col. Reynosa Tamaulipas, 02200 Mexico D. F. (Mexico); Raya A, R.; Cruz G, H. S., E-mail: roberto.raya@inin.gob.mx [ININ, Departamento del Reactor, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2013-10-15

    This work presents the measurement of the neutrons spectrum in energies in the central thimble of the reactor TRIGA Mark III to a power of 1 MW in stationary state, with the core in the center of the pool. To achieve this objective, several thin sheets were irradiated (one at the time) in the same position of the core. The activation probes were selected in such a way that covered the energy range (1 x 10{sup -10} to 20 MeV) of the neutrons spectrum in the reactor core, for this purpose thin sheets were used of {sup 197}Au, {sup 58}Ni, {sup 115}In, {sup 24}Mg, {sup 27}Al, {sup 58}Fe, {sup 59}Co and {sup 63}Cu. After the irradiation, the high energy gamma emissions of the activated thin sheets were measured by means of gamma spectrometry, in a counting system of high resolution, with a Hyper pure Germanium detector, obtaining this way the activity induced in the thin sheets whose magnitude is proportional to the intensity of the neutrons flow, this activity together to a theoretical initial spectrum are the main entrance data of the computational code SANDBP (Hungarian version of the code Sand-II) that uses the unfolding method for the calculation of the spectrum. (Author)

  2. Determination of the physical parameters of the nuclear subcritical assembly Chicago 9000 of the IPN using the Serpent code; Determinacion de los parametros fisicos del conjunto subcritico nuclear Chicago 9000 del IPN usando el codigo SERPENT

    Energy Technology Data Exchange (ETDEWEB)

    Arriaga R, L.; Del Valle G, E. [IPN, Escuela Superior de Fisica y Matematicas, Av. Instituto Politecnico Nacional s/n, U.P. Adolfo Lopez Mateos, Col. San Pedro Zacatenco, 07738 Mexico D. F. (Mexico); Gomez T, A. M., E-mail: guten_tag_04@hotmail.com [ININ, Departamento de Sistemas Nucleares, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2013-10-15

    For the Serpent code was developed the three-dimensional model corresponding to the nuclear subcritical assembly (S A) Chicago 9000 of the Escuela Superior de Fisica y Matematicas del Instituto Politecnico Nacional (ESFM-IPN). The model includes: a) the core, formed by 312 aluminum pipes that contain 5 nuclear fuel rods (natural uranium in metallic form), b) the multi-perforated plates where they penetrate the inferior part of each pipe to be able to remain in vertical form, c) water, acting as moderator and reflector, and d) the recipient lodging to the core. The pipes arrangement is hexagonal although the transversal section of the recipient that lodges to the core is circular. The entrance file for the Serpent code was generated with the data provided by the manual of the S A use about the composition and density of the fuel rods and others obtained in direct form of the rods, as the interior and external diameter, mass and height. Of the obtained physical parameters, those more approached to that reported in the manual of the subcritical assembly are the effective multiplication factor and the reproduction factor η. The differences can be because the description of the fuel rods provided by the manual of the S A use do not correspond those that are physically in the S A core. This difference consists on the presence of a circular central channel of 1.245 diameter centimeters in each fuel rod. The fuel rods reported in the mentioned manual do not have that channel. Although the obtained results are encouraging, we want to continue improving the model to incorporate in this the detectors, defined this way by the Serpent code, which could determine the existent neutrons flux in diverse points of interest like the axial or radial aligned points and to compare these with those that are obtained in an experimental way when a generating neutrons source (Pu-Be) is introduced. Added to this effort the cross sections for each unitary cell will be determined, so that these are used in a transport code developed in the ESFM-IPN. (Author)

  3. Determination of cross-section starting from a decay curve composed of two halves lives; Determinacion de la seccion eficaz a partir de una curva de decaimiento compuesta de dos vidas medias

    Energy Technology Data Exchange (ETDEWEB)

    Martinez Q, E.; Aguilera, E.F. [Instituto Nacional de Investigaciones Nucleares, Departamento del Acelerador, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    1998-07-01

    It is presented a method developed to determine the cross section of 3n channel of the fusion reaction {sup 6} He + {sup 209} Bi which is based in the {alpha} decay curve of residual nucleus, {sup 212} At. (Author)

  4. Development of a simplified methodology for the isotopic determination of fuel spent in Light Water Reactors; Desarrollo de una metodologia simplificada para la determinacion isotopica del combustible gastado en reactores de agua ligera

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez N, H.; Francois L, J.L. [FI-UNAM, 04510 Mexico D.F. (Mexico)]. e-mail: hermilo@lairn.fi-b.unam.mx

    2005-07-01

    The present work presents a simplified methodology to quantify the isotopic content of the spent fuel of light water reactors; their application is it specific to the Laguna Verde Nucleo electric Central by means of a balance cycle of 18 months. The methodology is divided in two parts: the first one consists on the development of a model of a simplified cell, for the isotopic quantification of the irradiated fuel. With this model the burnt one is simulated 48,000 MWD/TU of the fuel in the core of the reactor, taking like base one fuel assemble type 10x10 and using a two-dimensional simulator for a fuel cell of a light water reactor (CPM-3). The second part of the methodology is based on the creation from an isotopic decay model through an algorithm in C++ (decay) to evaluate the amount, by decay of the radionuclides, after having been irradiated the fuel until the time in which the reprocessing is made. Finally the method used for the quantification of the kilograms of uranium and obtained plutonium of a normalized quantity (1000 kg) of fuel irradiated in a reactor is presented. These results will allow later on to make analysis of the final disposition of the irradiated fuel. (Author)

  5. Utilization of shear stress for determination of activation energy of the defects created by neutron irradiation; Utilizacion de la tension de fluencia en la determinacion de la energia de activacion de defectos producidos por irradiacion neutronica

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, Hector C.; Miralles, Monica [Comision Nacional de Energia Atomica, Buenos Aires (Argentina)

    1996-07-01

    This paper describes an experimental technique used for the determination thermodynamical parameters such as activation energy using the thermal annealing of increments of Critical resolved Shear Stress of the defects created by neutron irradiation at 77 K. The doses chosen for this work was 3.1 x 10 {sup 16} n/cm{sup 2} since the defects are stable to plastic deformation and the cascades of atomic displacements do not overlap. Specimens without any prior deformation were used allowing then the single addition of the initial stress to that due to the created defects. (author)

  6. Determination of silver, gold, zinc and copper in mineral samples by various techniques of instrumental neutron activation analysis; Determinacion de plata, oro, zinc y cobre en muestras minerales mediante diversas tecnicas de analisis por activacion de neutrones instrumental

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez R, N. I.; Rios M, C.; Pinedo V, J. L. [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas, Zac. (Mexico); Yoho, M.; Landsberger, S., E-mail: neisla126@hotmail.com [University of Texas at Austin, Nuclear Engineering Teaching Laboratory, Austin 78712, Texas (United States)

    2015-09-15

    Using the method of instrumental neutron activation analysis, mineral exploration samples were analyzed in order to determine the concentrations of silver, gold, zinc and copper; these minerals being the main products of benefit of Tizapa and Cozamin mines. Samples were subjected to various techniques, where the type of radiation and counting methods were chosen based on the specific isotopic characteristics of each element. For calibration and determination of concentrations the comparator method was used, certified standards were subjected to the same conditions of irradiation and measurement that the prospecting samples. The irradiations were performed at the research reactor TRIGA Mark II of the University of Texas at Austin. The silver concentrations were determined by Cyclical Epithermal Neutron Activation Analysis. This method in combination with the transfer pneumatic system allowed a good analytical precision and accuracy in prospecting for silver, from photo peak measurement 657.7 keV of short half-life radionuclide {sup 110}Ag. For the determination of gold and zinc, Epithermal Neutron Activation Analysis was used, the photo peaks analyzed corresponded to the energies 411.8 keV of radionuclide {sup 199}Au and 438.6 keV of metastable radionuclide {sup 69m}Zn. On the other hand, copper quantification was based on the photo peak analysis of 1039.2 keV produced by the short half-life radionuclide {sup 66}Cu, by Thermal Neutron Activation Analysis. The photo peaks measurement corresponding to gold, zinc and copper was performed using a Compton suppression system, which allowed an improvement in the signal to noise relationship, so that better detection limits and low uncertainties associated with the results were obtained. Comparing elemental concentrations the highest values in silver, zinc and copper was for samples of mine Tizapa. Regarding gold values were found in the same range for both mines. To evaluate the precision and accuracy of the methods used, various geological reference materials with satisfactory results according to the certified values were analyzed. (Author)

  7. Determination of Th and U by neutron activation for gamma spectrometry calibration in situ; Determinacion de Th y U por activacion neutronica para calibracion de espectrometria gamma in situ

    Energy Technology Data Exchange (ETDEWEB)

    Nava M, F.; Rios M, C.; Mireles G, F.; Saucedo A, S.; Davila R, I.; Pinedo, J. L. [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98060 Zacatecas (Mexico); Landsberger, S., E-mail: iqnava@hotmail.com [University of Texas at Austin, Nuclear Engineering Teaching Laboratory, Pickle Research Campus, R9000 Austin, Texas 78712 (United States)

    2012-10-15

    Using the analysis by neutron activation to determine the profile of the thorium and uranium concentration calibration factors were obtained for their use in the gamma spectrometry in situ. Three sites were selected (San Ramon, Villa de Cos y la Zacatecana) and the analysis by activation was development in the Laboratory of Nuclear Engineering Teaching of the Texas University in Austin with the nuclear reactor Ut-TRIGA. Starting from the gamma spectra in situ, the areas of normalized photo-pick of the radioisotopes were: {sup 208}Tl and {sup 228}Ac for the thorium series and {sup 214}Pb and {sup 214}Bi for the uranium series. The averages of the factors found in units of (cpm/Bq/Kg) are of 105.63{+-}8.32 and 75.87{+-}4.61 for the thorium and uranium, respectively. (Author)

  8. Analysis by neutron activation in moss samples for the determination of Cr, Se, As and Hg; Analisis por activacion neutronica en muestras de musgos para la determinacion de Cr, Se, As y Hg

    Energy Technology Data Exchange (ETDEWEB)

    Mejia C, R.; Garcia R, G. [Instituto Tecnologico de Toluca, Departamento de Posgrado, Av. Tecnologico s/n, Fraccionamiento La Virgen, 52149 Metepec, Estado de Mexico (Mexico); Lopez R, C.; Avila P, P.; Longoria G, L. C., E-mail: rosario.mejia@inin.gob.mx [ININ, Departamento del Reactor, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2012-10-15

    This research work, presents a study of environmental monitoring in the Metropolitan Area of Toluca Valley using as bio-monitors to the mosses (bryophytes) native of different sites, analyzing the concentrations of As, Cr, Hg and Se, present in its structure. The analysis technique used to identify and to quantify to these elements was the Analysis by Neutron Activation, a nuclear analytic technique that allowed determining the concentrations at track level for its great versatility. Likewise the morphological study of the bryophyte Leskea angustata is presented by scanning electron microscopy. (Author)

  9. Spectrographic determination of impurities in ammonium hydrogen fluoride samples. II. Study of the behaviour of the added matrices; Determinacion espectrografica de impurezas en bibluoruro amonico. II. Estudio del comportamiento de las matrices adicionadas

    Energy Technology Data Exchange (ETDEWEB)

    Alduan, F. A.; Roca, M.; Capdevila, C.

    1979-07-01

    In order to account for the variations In the shape of the excitation-volatilization' curves and the values of the line intensities of the different impurities determined in ammonium bifluoride, the behaviour of the added matrices (graphite, 63203, GeO{sub 2}, MgO and ZnO) has been considered. With this aim the influence of the added matrices on the are discharge parameters (temperature and electronic concentration) and on the exhaustion rate of the electrode load as a function of the excitation time has been studied. On the other hand, the curve of variation of the line intensity of the metallic component of each matrix versus time has been obtained and the residues in the electrode cavity have been investigated by X-ray powder diffraction. (Author) 7 refs.

  10. Influence of geometry calibration in the determination of gamma emitters in active carbon filters; Influencia de la geometria de calibracion en la determinacion de emisores gamma en filtros de carbon activo

    Energy Technology Data Exchange (ETDEWEB)

    Laurado Tarrago, M.; Tent Petrus, J.

    2013-07-01

    Testing laboratories participate in external quality controls. For these controls are useful it is necessary to eliminate factors that can introduce sources of variability in the results. A factor to consider in this paper as a source of variability is the calibration geometry chosen for the correct quantification of the activity concentrations. This work contains the results of the intercomparison exercise and from them analysed the effect of the geometry of calibration used in the quantification of activity concentrations present in the activated carbon filter. (Author)

  11. Determination of low concentrations of pyridine in piperidine by gas chromatography and infrared spectroscopy; Determinacion de bajas concentraciones de piperidina en piridina por cromatografia de gases y espectroscopia infrarroja

    Energy Technology Data Exchange (ETDEWEB)

    Perez Garcia, M. M.; Parellada Bellod, R.

    1979-07-01

    This paper describes the determination of low amounts of piperidine in pyridine in the concentration range of 0-5%. After an exhausting review of the bibliography on the column selection, the chromatographic separation and determination are made on the following column: 27% Pennwalt- 223; 4% KOH on Gas-Chrom R; 80-100 mesh with flame ionization detector. The retention indexes of both compounds and tho Rohrschneider constants of the phase used are calculated. The minimum detection limit achieved for piperidine is 0,25%. (Author) 25 refs.

  12. Determination of silicon and chromium content in gray cast iron by the Van der Pauw method; Determinacion del contenido de silicio y cromo en fundiciones grises mediante el metodo de Van der Pauw

    Energy Technology Data Exchange (ETDEWEB)

    Tremps, E.; Enrique, J. L.; Moron, C.; Garcia, A.; Gomez, A.

    2013-07-01

    In this paper we show a system based on the resistivity measurement of samples of gray cast iron by the Van der Pauw method to calculate the silicon content in the samples. Twenty five trials have been carried out, studying resistive and metallographic characteristics of the samples. This has demonstrated that it is possible to obtain, by this method, the silicon content in molten flat with low content of alloying elements, also the content of chromium in series smelters where the rate of silicon remains constant. (Author)

  13. Determining the sustainability of ceramic and glass industry using environmental management tools; Determinacion de la sostenibilidad de la industria mineral de la ceramica y del vidrio mediante herramientas de gestion ambiental

    Energy Technology Data Exchange (ETDEWEB)

    Espi Rodriguez, J. A.

    2011-07-01

    In the last few years we have seen the creation of an everyday larger and varied series of are creating large and varied series of environmental management tools used to analyze and classify environmentally each mineral and its physical, economic and environmental circumstances. Thus we now, count with the Material Flow Analysis (MFA) of a mining operation, the Life Cycle Analysis (LCA), Energy and Exergy Analysis, Cost Benefit Environmental Analysis, Carbon Footprints, the Best Available Technology (BTA) and many others able to analyze and classify ore deposit site types, availability of resources, environmental impact conditions, transparency in communication and almost all crucial aspects related with the environmental geometry of the mining production process. This paper focuses on the application of some management tools that best fit to the minerals used in the ceramic and glass industry. (Author) 12 refs.

  14. 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)

  15. Monitoring organo chlorine pesticides in surface and ground water in San Juan (Argentina); Determinacion de pesticiddas organoclorados en aguas superficiales y subterraneas de la provincia de San Juan (Argentina)

    Energy Technology Data Exchange (ETDEWEB)

    Omar, B.; Suero, E.; Augusto, M.; Gimenez, M.; Flores, N.

    2003-07-01

    The level of contamination with organo chlorine pesticides and the occurrence of their degradation products in the basins of the two main rivers. San Juan and Jackal, of the Province of San Juan, Argentina, were determined. Surface and groundwater samples from both river basins were evaluated by capillary GC and results confirmed with Mass Spectrometry. Chemicals investigated were 16 organo chlorine pesticides. For a total number of 314 samples, the percentage of positive samples ranged from 68.6% for Heptachlor to 16% for Aldrin. concentration values and the percentage of positive samples in groundwater were significantly lower than those found in surface water. Samples taken in different seasons did not show significant differences. (Author) 18 refs.

  16. Determination of metallic impurities in raw materials for radioisotope production by atomic absorption spectroscopy; Determinacion de trazas metalicas en amterias primas para la produccion de radioisotopos por espectroscopia de absorcion atomica

    Energy Technology Data Exchange (ETDEWEB)

    Roca, M.; Alvarez, F.; Capdevila, C.

    1969-07-01

    Atomic absorption spectrometry has been used for the determination of traces of calcium in scandium oxide, copper in zinc, iron in cobalt oxide, manganese In ferric oxide, nickel in copper and zinc in gallium oxide. The influences on the sensitivities arising from the hollow cathode currents, the gas pressures and the acid concentrations have been considered. A study of the interferences from the metallic matrices has also been performed, the interference due to the absorption of the manganese radiation by the atoms of iron being the most outstanding . In order to remove the interfering elements and increase sensitivity, pre-concentration methods have been tested. The addition methods has also been used. (Author) 14 refs.

  17. Determination of the dose in eyes lens by TLD, in PET/CT by technicians in PET/CT service; Determinacion de la dosis en cristalino por medio de TLD, en personal tecnico de servicio PET/CT

    Energy Technology Data Exchange (ETDEWEB)

    Marino, Emiliano A., E-mail: eam.marino@gmail.com [Universidad Nacional de Cuyo (UNC), Rio Negro (Argentina). Instituto Balseiro; Arenas, German M. [Fundacion Escuela de Medicina Nuclear (FUESMEN), Mendoza (Argentina)

    2013-11-01

    This work was supported, on the one hand, in a part of the project ORAMED which consisted of a design of a TLD dosimeter for measurements of Hp (3) in areas close to the lens, for interventional radiology physicians. On the other hand, Berhens work proposes using calibrated TLDs Hp (0.07) and Hp (10) to estimate Hp (3) crystal. This resulted in dosimeters calibrated using Hp (10) slab, and mount them on glasses, to estimate the dose to the lens of the technical staff of the Service PET / CT. The value obtained 29mSv/year of Lens Dose Equivalent exceeds the recommended limit. We also demonstrate that, under the current working conditions, the values of Hp (3) reported from whole body dosimeter does not represent faithfully the lens dose.

  18. Determination of damage and In vivo DNA repairing through the unicellular in gel electrophoresis technique; Determinacion del dano y la reparacion del ADN In vivo mediante la tecnica de electroforesis unicelular en gel

    Energy Technology Data Exchange (ETDEWEB)

    Mendiola C, M.T.; Morales R, P. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    1997-07-01

    The experimental conditions were standardized for the unicellular in gel electrophoresis technique setting up (EUG) at the Cellular Radiobiology laboratory. Preliminary experiments were realized with human cells and mouse which were exposed to ionizing radiation or hydroxide peroxide (H{sub 2}O{sub 2}) to induce DNA damage and to verify the technique performance. It was analysed the In vivo repairing kinetics of induced damage by gamma radiation in mouse leukocytes which were exposed to {sup 137} Cs source and taking samples of peripheric blood of the tail of each mouse at different exposure times and processing them for EUG. In function of the cells proportion with damage in each time it was determined the existence of fast repairing mechanism at the first 15 minutes followed by a slight increase in the damage and a late repairing stage between 30 and 90 minutes. It was analysed this behavior and the potentiality of this In vivo system. (Author)

  19. Spectrophotometric determination of Fe(II) in Geological Materials by Using Ferrozine as Cromogenic Reagent; Determinacion Espectrofotometria de Fe(II) en Materiales Geologicos Utilizando Ferrozina como Reactivo Cromogenico

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez, D. M.; Martin, R.; Marin, J.; Morante, R.; Gutierrez, L.; Bayon, A. [Ciemat, Madrid (Spain)

    2000-07-01

    A rapid and sensitive spectrophotometric method for the determination of labil ferrous iron in geological materials is described. Samples are trated by boiling with hydrochloric acid for 60 min. in an atmosphere of carbon dioxide. Systematic erroneous results due to high concentrations of ferric iron are resolved. The limit of detection for the method was 0.02% of FeO. International standard granites analysed by the proposed method showed recoveries ranged from 81-102%. (Author) 9 refs.

  20. Determination and Distribution of Critical Loads: Application to the Forest Soils in the Autonomous Region of Madrid; Determinacion y Distribucion de Cargas Criticas: Aplicacion a los Suelos forestales de la comunidad Autonoma de Madrid

    Energy Technology Data Exchange (ETDEWEB)

    Sousa, M.; Schmid, T.; Rabago, I. [Ciemat, Madrid (Spain)

    2000-07-01

    The critical loads of acidity and sulphur have been determined for forest soils within the north and north-west of the Autonomous Region of Madrid. The SMB-CCE and SMB-PROFILE Steady state models have been applied using a 1 km x 1 km resolution. the forest ecosystems have been characterised according to the soil and forest type, slope and climatic data using a Geographic Information System. In order to estimate the critical loads, processes such as weathering rate of the parent material, atmospheric deposition, critical alkalinity leaching rate and nutrients absorbed by the vegetation have been considered. In general the forest soils present high critical load values for acidity and sulphur. The more sensitive zones are found in the north of the Sierra of Guadarrama. Independent of the applied methods, the results are associated to the types of soils where Leptosols have the lowest. Cambisoles and Regosoles intermediate and luvisoles the most elevated values. (Author) 40 refs.

  1. Calibration of a Gamma Spectrometry System Used for the Determination of Cs-137 in Spanish Soils; Puesta a Punto de un sistema de Expectrometria Gamma para la Determinacion de Cs-137 en Suelos Espanoles

    Energy Technology Data Exchange (ETDEWEB)

    Barreraa, M.; Romero, M. L.; Valino, F.

    2008-07-01

    The document describes the methodology used at CIEMAT in order to determine, by gamma spectrometry, the background levels of the radionuclide Cs-137 in soils of the Spanish peninsular territory. the work is a part of an extensive research project developed jointly by the University of the Basque Country (UPV-EHU) and the CIEMAT, endellite Content and migration of radiocaesium and radiostrontium in Spanish soils, which is funded by the Plan I+D of the Spanish Nuclear Security Council (CSN). The objective of the project is to establish the reference levels of man-made radionuclides in Spanish soils, with respect to which the evaluation of a possible posterior accidental release of radioactive material could be appraised. The activity concentration of the fission products Cs-137 has been determined in 34 soil cores extracted from representative Spanish soils type zones. This publication describes the experimental system employed, its calibration, the particular conditions applied to perform the measurements, as well as the experimental validation of the methodology. The activity profiles and inventories of the radioactive element so obtained are also presented. The estimation of the background Cs-137 reference levels, will provide a basis for later applications as the study of the spatial distribution in the region, the determination of the correlation between the deposited activity and the meteorological conditions, or the calculation of the specific migration parameters of the radioactive elements in Mediterranean conditions. (Author) 15 refs.

  2. Comparison in the determination of absorbed dose by biological and physical methods to patients in treatment of cardiac intervention; Comparacion en la determinacion de dosis absorbida por metodos biologicos y fisicos a pacientes en tratamiento de intervencionismo cardiaco

    Energy Technology Data Exchange (ETDEWEB)

    Guerrero C, C.; Arceo M, C., E-mail: citlali.guerrero@inin.gob.mx [ININ, Departamento de Biologia, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2014-10-15

    The use of less invasive procedures, lower risk and quick recovery as cardiac intervention have proven to be an efficient alternative to reestablish the correct bloodstream of the patient. In this case the patient is subjected to values of absorbed dose above to which is subjected in a study with X-rays for medical diagnosis, and this can cause radiation injuries to the skin. The target organ, in this case can be exposed to doses of 2 Gy above. Different methods to estimate the dose were use, physical by Radiochromic film, as biological by dicentric analysis. Both methods provided additional information demonstrating thus the risk in the target organ and the patient. The most reliable biological indicator of exposure to ionizing radiation is the study of chromosomal aberrations, specifically dicentric in human lymphocytes. This test allowed establishing the exposure dose depending of the damage. (Author)

  3. Determination of stresses caused by fluctuation of acoustic load in the steam dryers of a BWR; Determinacion de esfuerzos originados por fluctuacion de carga acustica en los secadores de vapor de un reactor BWR

    Energy Technology Data Exchange (ETDEWEB)

    Centeno P, J.; Quezada G, S.; Prieto G, A.; Vazquez R, A.; Espinosa P, G. [Universidad Autonoma Metropolitana, Unidad Iztapalapa, Av. San Rafael Atlixco No. 186, Col. Vicentina, 09340 Mexico D. F. (Mexico); Nunez C, A., E-mail: javcuami26@hotmail.com [Comision Nacional de Seguridad Nuclear y Salvaguardias, Dr. Jose Ma. Barragan No. 779, Col. Narvarte, 03020 Mexico D. F. (Mexico)

    2014-10-15

    The extended power up-rate (EPU) in a nuclear power plant cause various problems in BWR components also in the steam system. This due to increased steam flow generated in the reactor and is conveyed to the turbine by the four main steam lines (MSL). One of the most serious problems is the generation of acoustic pressure loads in the metal structure of the steam dryer which eventually leads to fatigue failure and even the appearance of cracks, and in turn it causes loose parts that are entrained by the steam and transported in the MSL. This problem is due to the fluctuation of load acoustics caused by the union of the safety or relief valves (SRV) with the MSL, spreading through these to reach the reactor pressure vessel (RPV) where the effect of resonance of the acoustic wave is amplified and impacts directly in the supporting structure of the steam dryer, skirt and the panels where the mixture liquid-steam is dried, by centrifugation effect and runoff of liquid water. Efforts in the steam dryer operating conditions of EPU for two cases will be analyzed in this work, the first is before the installation of Acoustic Side Branch (ASB), and in the second case we consider the installation of said ASB in the standpipes of SRV. The analysis was performed with numerical experiments on a platform for computational fluid dynamics with virtual geometries previously designed based on the actual components of the reactor and steam system. The model to study is delimited by the top of the RPV, the steam dryer and a section of each of the four MSL with ten standpipes of SRV. With the obtained data and considering the mechanical-structural properties of the steam dryer material, we can evaluate the mechanical resistance to impacts by acoustic pressure load and its possible deformation or cracking. (Author)

  4. Determination of the stability constants of lanthanum, praseodymium, europium, erbium and lutetium complexes with chloride ions; Determinacion de las constantes de estabilidad de los complejos de lantano, praseodimio, europio, erbio y lutecio con iones cloruro

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez R, E. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    2008-07-01

    The stability constants of La{sup 3+}, Pr{sup 3+}, Eu{sup 3+}, Er{sup 3+} and Lu{sup 3+} chloride complexes were determined in perchloric acid media using a liquid-liquid extraction method. The dinonyl napthalene sulfonic acid in n-heptane was used as extractant. The lanthanide (Ln) concentrations were measured by a radiochemical (Eu and Lu) and a spectrophotometric (La, Pr, and Er) methods. In the last method, xylenol orange was used for the determinations at ph 6. The stability constants of lanthanum, praseodymium, erbium and lutetium chloride complexes were determined in 2, 3 and 4 M ionic strength and europium in 1, 2 and 3 M, at 303 K. The fitting of experimental data to the equations for the calculation of the stability constants, was carry out considering both one chemical species (LnCl{sup 2+}) or two chemical species (LnCl{sup 2+} and LnCl{sub 2}{sup +}). The Specific Ion Interaction Theory was applied to the values of log {beta}{sup I}{sub Ln},{sub Cl} and the first stability constants at zero ionic strength were calculated by extrapolation. The same theory could not be applied to the log {beta}{sup I}{sub Ln},{sub 2Cl}, due to its low abundance and the values determined for the stability constants were similar. The distribution diagrams of the chemical species were obtained using the program MEDUSA and considering log {beta}{sup I}{sub Ln},{sub CI}, log {beta}{sup I}{sub Ln},{sub 2CI} values obtained in this work and the hydrolysis constants taken from the literature. The lanthanide chloride complexes are present in solution at specific conditions of ionic strength, concentration and in the absence of hydrolysis. The log {beta}{sup I}{sub Ln},{sub Cl} data were related to the charge density and the corresponding equations were obtained. These equations could be used to determine the stability constants along the lanthanide series. (Author)

  5. Analytical Issues on the Determination of Carotenoids in Microalgae by Liquid Chromatography with Diode Array Detector; Aspectos Analiticos sobre la Determinacion de Compuestos Carotenoides en Microalgas mediante Cromatografia de Liquidos con Detector de Diodos

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, S.; Perez, R. M.

    2012-04-11

    A preliminary study of literature review on the determination of carotenoids in microalgae samples by HPLC with diode array detector is presented. Main objective has been focused to compile data from literature and based on the main aspects of the analytical methodology used in the determination of these compounds. The work is structured as follows and affecting major analytical difficulties: Procurement and commercial availability of standard solutions. Stage of sample treatment. Chromatographic analysis. (Author) 19 refs.

  6. Radioactive wastes repository in Temascalapa, State of Mexico, public opinion. Determination of health effects; Repositorio de residuos radiactivos en Temascalapa Estado de Mexico, Opinion publica. Determinacion de efectos en la salud

    Energy Technology Data Exchange (ETDEWEB)

    Solis Tinoco, E

    1998-12-31

    Nuclear waste usually concerns public about the impact on public health and the environment. In Mexico, such interest exists, particularly in the Temascalapa Municipality, Mexico where a low level waste repository recognized by the IAEA, has been functioning since 1972. Maquixco repository is located at 42 Kilometers northeast of Mexico City. Although the environmental radiological monitoring records have demonstrated negligible impact on the environment, in 1998 an unusual public polemic on radioactive health effects appeared among Temascalapa residents. This paper presents a research performed during 1998 with the participation of the National Nuclear Research Institute of Mexico and the National Autonomous University of Mexico. The research design allowed the involvement of local authorities, as a way of stimulate public participation. The research was performed in nine locations of the Temascalapa Municipality, it was focused on public polemics, associated to Maquixco repository as well as trying to identify demographic factors that exert influence on public attitudes. There are also presented the results of personal dosimetry analysis performed on a four hundred residents sample of this Municipality. (Author)

  7. EURADOS action for determination of americium in skull measures in vivo and Monte Carlo simulation; Accion EURADOS para la determinacion de americio en craneo mediante medidas in-vivo y simulacion Monte Carlo

    Energy Technology Data Exchange (ETDEWEB)

    Lopez Ponte, M. A.; Navarro Amaro, J. F.; Perez Lopez, B.; Navarro Bravo, T.; Nogueira, P.; Vrba, T.

    2013-07-01

    From the Group of WG7 internal dosimetry of the EURADOS Organization (European Radiation Dosimetry group, e.V.) which It coordinates CIEMAT, international action for the vivo measurement of americium has been conducted in three mannequins type skull with detectors of Germanium by gamma spectrometry and simulation by Monte Carlo methods. Such action has been raised as two separate exercises, with the participation of institutions in Europe, America and Asia. Other actions similar precede this vivo intercomparison of measurement and modeling Monte Carlo1. The preliminary results and associated findings are presented in this work. The laboratory of the body radioactivity (CRC) of service counter of dosimetry staff internal (DPI) of the CIEMAT, it has been one of the participants in vivo measures exercise. On the other hand part, the Group of numerical dosimetry of CIEMAT is participant of the Monte Carlo2 simulation exercise. (Author)

  8. Correction for the interference of strontium in the determination of uranium in geologic samples by X-ray fluorescence; Correccion de la interferencia del estroncio en la determinacion del uranio en materiales geologicos mediante fluorescencia de rayos X

    Energy Technology Data Exchange (ETDEWEB)

    Roca, M.; Bayon, A.

    1981-07-01

    A suitable empirical algorithm for the correction for the spectral interference of the SrK{alpha} on the UL{alpha} line has been derived. It works successfully for SrO concentrations up to 8% with a minimum detectable limit of 20 ppm U{sub 3}O{sub 8}. X-ray spectrometry procedure allows also the determination of the SrO contents of the samples. A program in BASIC language for data reduction has been written. (Author) 3 refs.

  9. The use of re espirometry in determining the inhibition produced by toxic substances in activated sludge; Empleo de la respirometria en la determinacion de la inhibicion provocada sobre lodos activados por sustancias toxicas

    Energy Technology Data Exchange (ETDEWEB)

    Quesada, I.; Jaureguil, U.; Menendz, C.

    2001-07-01

    In manufacturing pharmaceuticals processes such as synthesis, fermentation and extractions are commonly employed. Such processes generate waste waters, with an organic content that is not very biodegradable, as they also contain inhibiting substances. in the first place, inhibition due to formaldehyde on a sludge medium, as measured by its respiratory activity, was studied at concentrations of 90, 180 and 360 mg/l. The results obtained were plotted on a graph and an almost straight line was found to correlate the degree of inhibition to the concentration of formaldehyde. In view of the reliability of this method, also backed up by the literature, several more tests were carried out, this time using streptomycin as the inhibitor. In this case it was found that the respiratory activity of the activated sludge was reduced to 50% with a streptomycin concentration of 19 mg/l. A further study using inhibition halos showed that concentrations of <10 mg/l did not affect the organisms studied (E, coli, Ps aeruginosa and B, subtilis). However, inhibition was found at concentrations of the antibiotic of 30 mg/l especial in the case of B, subtilis. (Author) 17 refs.

  10. Determination of the dose rapidity of a {sup 90} Sr beta radiation source using thermoluminescent dosemeters; Determinacion de la rapidez de dosis de una fuente de radiacion beta de {sup 90}Sr usando dosimetros termoluminiscentes

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez M, P.R.; Azorin N, J.; Rivera M, T. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    2000-07-01

    The thermoluminescent dosemeters developed in Mexico, have been used efficiently in environmental and personal dosimetry. When the dose rate of some source is not known can be estimated with the use of thermoluminescent dosemeters taking in account the geometrical array used in the irradiations for reproducibility of the results in posterior irradiations. In this work it was estimated the dose rate of a {sup 90} Sr-{sup 90} Y beta radiation source which is property of the Nuclear Sciences Institute, UNAM, therefore it was l ended to the Metropolitan Autonomous University- Iztapalapa Unit for the characterization of new Tl materials, taking account of the institutional collaboration agreements. (Author)

  11. Determination of dose to patient in different teams of TC and assessment with international reference levels; Determinacion de dosis a pacientes en diferentes equipos de TC y evaluacion con niveles de referencia internacionales

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz Morales, C.; Fernandez lara, A. A.; Buades Forner, M. J.; Tobarra Gonzalez, B. M.

    2013-07-01

    The increase in CT studies and the differences observed between the different equipment used in our hospital prompted us to determine the doses to patients in different studies and check the results obtained with the reference values published internationally. (Author)

  12. Analytical Evaluation to Determine Selected PAHs in a Contaminated Soil With Type II Fuel; Metodo Optimizado de Extraccion por Ultrasonidos para la Determinacion de PAHs Seleccionados en un Suelo Contaminado con Fuel de Tipo II

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Alonso, S.; Perez Pastor, R. M.; Sevillano Castano, M. L.; Garcia Frutos, F. J.

    2010-10-21

    A study on the optimization of an ultrasonic extraction method for selected PAHs determination in soil contaminated by type II fuel and by using HPLC with fluorescence detector is presented. The main objective was optimize the analytical procedure, minimizing the volume of solvent and analysis time and avoiding possible loss by evaporation. This work was carried out as part of a project that investigated a remediation process of agricultural land affected by an accidental spillage of fuel (Plan Nacional I + D + i, CTM2007-64 537). The paper is structured as: Optimization of wavelengths in the chromatographic conditions to improve resolution in the analysis of fuel samples. Optimization of the main parameters affecting in the extraction process by sonication. Comparison of results with those obtained by accelerated solvent extraction. (Author) 3 refs.

  13. Benzene Synthesis for ''14C Measurements and Evaluation of Uncertainty in Mollusk Shells; Sintesis de Benceno para la Determinacion de C''14 y Evaluacion de su Incertidumbre en Conchas de Moluscos

    Energy Technology Data Exchange (ETDEWEB)

    Romero del Hombrebueno, B.; Simon, M. A.; Larena, P.

    2002-07-01

    This work describes the method and instrumentation used by Environmental Isotopes laboratory of the CIEMAT Analytical Chemistry Laboratory (DIAE) for the synthesis of benzene from carbonates of mollusk shells and the liquid scintillation counting of ''14C for radiocarbon dating in these samples. The usefulness of mollusk shells for ''14 C dating are considered. (Author)

  14. Concentración de la propiedad y contenidos de la televisión abierta nacional de Colombia 1998 - 2015: entre las determinaciones del rating y el proyecto educativo-cultural

    OpenAIRE

    Coa Murillo, Ana Lucía

    2017-01-01

    En esta tesis se analizan los contenidos de la televisión abierta nacional de Colombia desde 1998, fecha en la que aparecieron los canales privados, hasta el 2015, para conocer de qué maneras la concentración de la propiedad de los medios ha configurado las lógicas de producción y programación de sus contenidos. La investigación se inscribe en el marco de la Economía Política de la Comunicación en América Latina, que tiene la concentración de la propiedad de los medios como uno de sus objetos...

  15. Preparation and determination of the luminescent characteristics of ZrO{sub 2} in powder; Preparacion y determinacion de las caracteristicas luminiscentes del ZrO{sub 2} en polvo

    Energy Technology Data Exchange (ETDEWEB)

    Rivera M, T. [ESIME-IPN Unidad Culhuacan Mexico D.F. (Mexico); Olvera T, L.; Azorin N, J.; Soto E, A.M.; Velazquez O, C.; Campero C, A. [UAM-I, 09340 Mexico D.F. (Mexico)

    2004-07-01

    In this work the luminescent characteristics of the ZrO{sub 2} are presented using the method of Thermally Stimulated Luminescence (TSL), also called thermoluminescence (Tl). The powders of ZrO{sub 2} were obtained by two preparation methods: for precipitation and for evaporation of Sol-gel. The luminescent characteristics of the ZrO{sub 2} are determined using a lamp of radiation of UV light and a radiation source of beta particles of {sup 90}Sr/{sup 90}Y. Using the method of thermal stimulation the curve representative thermoluminescent of the previously irradiated material was obtained. The curve Tl of the ZrO{sub 2} irradiated with UV light presents a maximum in 180 C. Likewise, the spectrum of the curve Tl of the ZrO{sub 2} irradiated with particles beta presents a maximum centered in 181 C. While using gamma radiation like excitement source one has a spectrum with a peak centered in 184 C. When subjecting the materials obtained by sol-gel to a process of calcination at 1000 C for 24 hours a curved Tl it presents with two maxim in 185 and in 290 C respectively. The intensity of the response induced in the material it is a decisive factor to continue studying the dosimetric characteristics of the ZrO{sub 2} what allows to consider it as a potential material to use it in the beta particle dosimetry and of the UV light using the thermoluminescence method (Tl). (Author)

  16. Establishment of the conditions for the determination of the concentration of the uranyl ion in perchloric media by Fluorescence; Establecimiento de las condiciones para la determinacion de la concentracion del ion uranilo en medio perclorico por Fluorescencia

    Energy Technology Data Exchange (ETDEWEB)

    Contreras R, A.; Ordonez R, E.; Fernandez V, S.M. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)]. e-mail: contraida@yahoo.com.mx

    2004-07-01

    The influence of the p H is reported in the spectra of luminescence of the ion uranyl in sodium perchlorate 2M. The best spectra were observed to ph <3 that to neutral and basic p Hs this is explained by the present species. They were carried out four calibration curves for the uranyl in perchloric acid media, taking into account the area under the curve, the maximum height of two characteristic peaks of this ion, in those that one observes a better correlation with the maximum height of the peak located to 486.7 nm. (Author)

  17. Geological determination of the limits, area and volume of the geothermal reservoir of the Los Humeros geothermal field, Puebla, Mexico; Determinacion geologica de los limites, area y volumen del yacimiento geotermico de Los Humeros, Puebla, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Castillo Hernandez, Daniel [Gerencia de Proyectos Geotermoelectricos, Comision Federal de Electricidad, Morelia, Michoacan (Mexico)

    1999-08-01

    A geologic analysis to determine the limits, area and volume of the exploitable reservoir of the Los Humeros Geothermal Field, in Puebla, Mexico was carried out. We defined the structural boundaries, both at surface and at deep that seem to control the distribution of the fluids of high enthalpy and favor or limit the production of steam. With 40 wells drilled to date, an average thickness of the lithological producer Unit of 1 163 m has been estimated. A surface of 12.54 km{sup 2} was calculated, that with the estimated thickness, gives a volume of the reservoir of 14.6 km{sup 3}. We consider that there are two main production sectors in the Geothermal Field: The Central Collapse and The Mastaloya Corridor. [Spanish] Se realizo un analisis geologico para determinar los limites, area y volumen del yacimiento explotable del campo geotermico de Los Humeros en Puebla, Mexico. Se definen las barreras estructurales, tanto superficiales como del subsuelo, que controlan la distribucon de los fluidos de alta entalpia que favorecen o limitan la produccion de vapor. Con los 40 pozos perforados hasta la fecha, se estima un espesor promedio de la unidad productora de 1 163 m. Se calculo una superficie de 12.54 km{sup 2}, la que con el espesor mencionado, da un volumen del yacimiento de 14.6 km{sup 3}. Se plantea que dentro del campo existen dos sectores principales de produccion. El Colapso Central y el Corredor de Mastaloya.

  18. 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)

  19. Determination of trace amounts of selenium in minerals and rocks by flame less atomic-absorption spectrometry; Determinacion de selinio en minerales y rocas por espectrometria de absorcion atomica

    Energy Technology Data Exchange (ETDEWEB)

    Alduan, F. A.; Capdevilla, C.

    1980-07-01

    The determination of trace amounts of selenium In silicate rocks and feldspar by solvent extraction and graphite furnace atomic-absorption spectrometry has been stu- died. Sodium diethyl-ditio carbamate and ammonium pyrrolidine dithiocarbamate have been tried as chelating agents. The best results are achieved when selenium is extracted Into carbon tetrachloride as the sodium diethyldithiocarbamate complex. The method allows to detect 0,75 ppm of selenium in the sample. Recoveries are about 100%. (Author) 7 refs.

  20. Combinación de sistemas de flujo de baja y alta presion para la determinacion de Mg, Ca y Sr en salmueras por espectrofotometria de absorcion atomica con llama Combination of low- and high-pressure flow systems for the determination of Mg, Ca and Sr in brines by flame atomic absorption spectrometry

    Directory of Open Access Journals (Sweden)

    José Neira

    2001-04-01

    Full Text Available This article describes the combination of low- and high-pressure flow systems for the determination of Magnesium, Calcium and Strontium by flame atomic absorption spectrometry (FAAS. In the low-pressure system a short C-18 RP column (length 0,5 cm was utilized for the preconcentration/matrix separation step, xylenol orange was used as chelating agent and tetrabutylamonium acetate for ion pair formation. The hydraulic high pressure nebulization (HHPN was used for sample transport and sample introduction in the high pressure system. The repeatabilities and detection limits for Mg, Ca and Sr were determined and compared with those obtained by pneumatic nebulization (PN. The results show that the detection limits obtained using the HHPN for Mg, Ca and Sr are between 1.5 to 2 times better than those obtained by PN when the signal transient was measured in area. The system presented a sampling frequency of 130 h-1 for direct determination of Mg, Ca or Sr in samples of saturated sodium chloride used in the production of chlorine and sodium hydroxide.

  1. The biological degradation as an energy option, determination of the effects of the aerobic phase on the subsequent production of biogas in a sanitary landfill; La degradacion biologica como una opcion energetica, determinacion de los efectos de la fase aerobia sobre la subsecuente produccion de biogas en un relleno sanitario

    Energy Technology Data Exchange (ETDEWEB)

    Aguilar Juarez, Oscar [Asesoria de Servicios Ambientales del Bajio (ASSB), (Mexico)

    2010-07-01

    The present work deals with the energy evaluation of biological processes as energy source and is based on works concerning laboratory, pilot and field research. The objective of the research is to integrate the effect of the aerobic phase during the process of degradation of organic residues (basically the organic fraction of domestic residues), where the last aim is the biogas production. The usefulness of the results is reflected in the suitable estimation of the filling of a sanitary landfill considering the composition of the residues deposited and the effects that this management will have on the run-up time of the same and the velocity of biogas production. Finally, integrates a reflection on the intrinsic energy implications of the process and of the biogas yielding, which is evaluated as well as energy source. [Spanish] El presente trabajo trata sobre la valoracion energetica de procesos biologicos como fuente de energia y se basa en trabajos de investigacion a nivel de laboratorio, piloto y de campo. El objetivo de la investigacion es integrar el efecto de la fase aerobia durante el proceso de degradacion de residuos organicos (basicamente la fraccion organica de residuos domesticos), donde el fin ultimo es la produccion de biogas. La utilidad de los resultados se refleja en la estimacion adecuada del llenado de un relleno sanitario considerando la composicion de los residuos ahi depositados y los efectos que tendra esta gestion sobre el tiempo de estabilizacion de los mismos y la velocidad de produccion de biogas. Finalmente, se integra una reflexion sobre las implicaciones energeticas intrinsecas al proceso y del rendimiento de biogas, el cual a su vez es valorizado como fuente de energia.

  2. Importance of salt in the production matrix of the efficiency curve for the determination of the total alpha activity in water samples; Importancia de la matriz salina en la fabricacion de la curva de eficiencia para la determinacion del indice de actividad alfa total en muestras de agua

    Energy Technology Data Exchange (ETDEWEB)

    Baeza, A.; Corbacho, J. A.

    2011-07-01

    The determination of total alpha activity by the evaporation method allows obtaining, from a quick and inexpensive technique, the order of magnitude of the total activity of all alpha emitters present in a sample of water. This study shows that the detection efficiency curve varies significantly depending on the sodium salt is used to manufacture calibration and/or reference radionuclide used. (Author)

  3. Concentration levels of alpha emitting radionuclides in natural waters. Implications in the use of various radionuclides of reference for the determination of total alpha activity index; Niveles de concentracion de radionucleidos emisores alfa en aguas de origen natural. Implicaciones en el uso de los distintos radionucleidos de referencia para la determinacion del indice de actividad total alfa

    Energy Technology Data Exchange (ETDEWEB)

    Corbacho, J. A.; Baeza, A.; Guillen, J.; Valles, I.; Serrano, I.; Camacho, A.; Montana, M.

    2013-07-01

    The present study was carried out a statistical evaluation of the natural radioactive contents of a large number of water samples collected at different points of the Spanish geography, in order to meet its controlling radioactive composition and assessing the implications of total alpha activity index can have in this type of samples. (Author)

  4. Determination of uranium isotopes ({sup 235}U, {sup 238}U) and trace elements (Cd, Pb, Cu and As) in bottled drinking water by Icp-SFMS; Determinacion de isotopos de uranio ({sup 235}U, {sup 238}U) y elementos traza (Cd, Pb, Cu y As) en agua embotellada para beber por ICP-SFMS

    Energy Technology Data Exchange (ETDEWEB)

    Lara A, N.; Hernandez M, H.; Romero G, E. T.; Kuri de la C, A.; Perez B, M. A., E-mail: nancy.lara@inin.gob.mx [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2016-09-15

    In the present work we propose an optimized method for the quantification of uranium isotopes ({sup 235}U, 2{sup 38}U) and the elements Cd, Pb, Cu and As in bottled water for drinking at trace levels of concentration. Based on the multi-element detection capability, the high sensitivity and resolution that the Mass Spectrometry with Magnetic Sector with Inductively Coupled Plasma Source (Icp-SFMS) technique offers; the high, medium and low resolution analysis conditions for the elements under study were established and optimized using and Element 2/Xr equipment and the 23 multi-elemental Certified Reference Material (CRM). The analysis method was validated using the standard reference material Nist 1643d and CRM mono-elemental s as external standards for the quantification of the analytes. Samples, targets and CRM were acidified with 2% of HNO{sub 3} and analyzed without pretreatment under the established analysis conditions. The results obtained show concentrations of {sup 235}U, {sup 238}U, {sup 111}Cd, {sup 208}Pb, {sup 63}Cu and {sup 75}As in the range of μg L{sup -1}, the linearity obtained from the calibration curves for each element has correlation coefficients < 0.99 in all cases, the accuracy of the method in terms of percent relative standard deviation (RSD %) was less than 5%, the mean recovery rate of Nist 1643d ranged from 96.46% to 101.12%. The optimization of the method guarantees the stability and calibration of the equipment throughout the analysis, as well as the ability to resolve interferences. In conclusion, the method proposed using Icp-SFMS offers the advantages of being fast and simple for the multi-elemental analysis in water at trace levels, with low limits of quantification and detection, with good linearity, accuracy, precision and reproducibility to a degree of reliability of 95%. (Author)

  5. 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)

  6. Development of an analytical method for the direct determination of uranium isotopes in occupationally exposed personnel urine samples using Icp-SFMS; Desarrollo de un metodo analitico para la determinacion directa de isotopos de uranio en muestras de orina de personal ocupacionalmente expuesto (POE) usando ICP-SFMS

    Energy Technology Data Exchange (ETDEWEB)

    Torres C, C. O.; Hernandez M, H.; Romero G, E. T. [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Vega C, H. R., E-mail: hector.hernandez@inin.gob.mx [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98060 Zacatecas, Zac. (Mexico)

    2016-09-15

    The development of an analytical method for measuring actinides in radioactive waste, environmental and biological samples has been a major challenge in institutions dedicated to the nuclear sector. Is for this reason that the developed and validated methods to measure isotopes of elements belonging to the actinide family have as main objective the characterization of radioactive wastes, the monitoring of radioactive installations and the dosimetric evaluation of occupationally exposed personnel, this for the purpose to prevent incidents or radiological accidents and to safeguard workers. This research work is focused on determining isotopes of uranium (U) and obtaining isotope ratios in urine samples of occupationally exposed personnel using a Magnetic Sector Mass Spectrometer with Inductively Coupled Plasma Source (Icp-SFMS), which is a versatile and promising technique for a large number of applications. The urine samples are acidified in order to favor the dissolution of the analytes in the samples, minimizing as much as possible their loss by sorption in the walls of the sampling bottle. For the determination of U in urine samples, dilution was performed, taking 2 ml of the urine samples and weighing it to 100 ml with 2% ultra pure HNO{sub 3} and finally performing the measurement by Icp-SFMS. The results obtained in the measurements of U show an order of magnitude in terms of sensitivity offered by Icp-SFMS. The isotopic ratios {sup 234}U/{sup 238}U, {sup 235}U/{sup 238}U are very close to the results reported by the literature and the quantification of the isotopes of said element show be within the concentration range of U, indicating that is exposed to depleted U. Additionally, Limit of Detection and Quantification Limit calculations were performed, which are of the order of pg mL{sup -1}. (Author)

  7. A geodetic coseismic fault-slip model for the May, 11{sup t}h 2011 Lorca earthquake using radar interferometry and GPS; Determinacion geodesica del deslizamiento de falla para el terremoto de Lorca del 11 de Mayo de 2011 usando interferometria radar y GPS

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, P. J.; Tiampo, K. F.; Palano, M.; Cannovo, F.; Fernandez, J.

    2012-07-01

    The Alhama de Murcia Fault (AMF) is a compound multi-segmented oblique left-lateral fault system. The AMF is one the longest faults in the Eastern Betics Shear zone (Southeastern Spain). In the last decades its seismogenic potential has been carefully evaluated based on paleoseismological data. On May 11{sup t}h, 2011 a moderate (Mw 5.1) earthquake shook the region, causing nine casualties and severe damage in Lorca city (Murcia region). The early reported location of the aftershock sequence did not draw any particular trend; furthermore in-situ geology surveys did not identify any surface coseismic slip-related ground deformation. In order to provide better seismic hazard assessments, we need to locate and, if possible, characterize the fault-slip distribution that generated this earthquake. In this work, we detected small but significant ground deformation close to the epicentral area of the Lorca earthquake by using geodetic (satellite radar interferometry and GPS) data. Geodetic data was processed by using a stack of differential radar interferograms (corrected for a known long-term subsidence contribution), daily GPS estimated coordinates and high-rate 1-Hz GPS data. We jointly inverted the detected static coseismic displacements for the fault plane geometry parameters by using a rectangular dislocation model embedded in a homogeneous elastic half-space. The best-fitting fault plane closely follows the geologically derived AMF geometry (NE-SW strike trend and dipping {approx}70 degree centigrade to NW). Later, the obtained model geometry was extended and divided into patches to allow for a detailed analysis of the fault slip distribution pattern. Slip distribution indicates that slip occurred in a main patch 4-5 km long with reverse and left lateral motion (with peak fault slip magnitude of {approx}20 cm). However, the modelling results also indicate that fault slip occurred close to the surface along the centre and southwest of the city of Lorca. The shallower character of the slip and the effect of a finite dynamic rupture fault arrest probably caused the relatively intense ground acceleration recorded in the city of Lorca ({approx}0.4g) and increased the building damage. This study also represents the first modern geodetic ally observed ground deformation signature due to seismic activity in the Iberian Peninsula. (Author) 33 refs.

  8. Risk evaluation on internal corrosion of a gas pipeline cut section based on metal mechanic tests and physiochemical analysis of the solids deposited in the pipes; Determinacion del riesgo por corrosion interna de un tramo cortado de una linea de transporte de gas natural a partir de ensayos metalmecanicos y del analisis fisicoquimico de los solidos depositados en la tuberia

    Energy Technology Data Exchange (ETDEWEB)

    Ditta Sarmiento, Johanna Milena [PETROBRAS International (BRASPETRO) (Colombia). Ingenieria de Corrosion DPSU

    2003-07-01

    After inspecting a one of the most important pipelines in Colombia, using intelligent tool, the pipe sections were selected that presented losses of thickness which probably they would be risking integrity of the same one and after, these sections were cut and replaced. To one of the cut sections a study with the objective was made him establish the present forms of corrosion and to determine the phenomena that influenced the presence of the damages. For this study were moderate thicknesses of the wall of the tube and was determined the criticality comparing it with its nominal thickness, according to Standard ASME B - 31G. Taking advantage of the presence solids in the surface, one became both, physical and chemical analysis, DRX and elementary analysis, with the objective to determine its origin and to correlate it with the types of corrosion that were in the line. The morphology that determined were Microbiological Influenced Corrosion, Erosion - Corrosion, Pitting and CO2 corrosion. Then, from all this information the analysis becomes of risks by internal corrosion in pipeline, the plan of mitigation and the plans of monitoring and inspection of the line to avoid the presence of anyone of these forms of corrosion in the future immediate. (author)

  9. Identification of ftalates used as additives in the geo membrane of a la Florida reservoir through gas chromatography-mass spectrometry; Determinacion de las ftalatos utilizados como aditivos en la geomembrana de la bolsa de la florida mediante cromtografia de gases-espectrometria de masas

    Energy Technology Data Exchange (ETDEWEB)

    Blanco, M.; Rico, G.; Pargada, L.; Aguiar, E.; Castillo, F.

    2009-07-01

    This article studies the behaviour of the plastified poly (vinyl chloride) (PVC-P) applied as synthetic geo membrane for the waterproofing of the La Florida reservoir. We show the results of the initial examen of its properties and its most significant characteristics eighteen years after being applied. Furthermore we isolate and identify the quantitative and qualitative aspects of the plasticizers used in its formula through infrared spectroscopy, gas chromatography and mass spectrometry technic. We have identified as the said plasticizers di-n-octyl phthalate, di-n-decyl phthalate and n-decyl n-octyl phthalate, and we calculate the joint average molecular weight using Wilsons equation. The results found that the geo membranes we have studied has shown an excellent behaviour along through time. (Author) 53 refs.

  10. Analysis of sodium metal by X-ray fluorescence spectrometry (I). Determination of Hf, Mo, Nb, Ta, Ti, V and Zr; Analisis de sodio metal por espectrometria de fluorescencia de rayos X. Determinacion de Hf, Mo, Nb, Ta, Ti, V y Zr

    Energy Technology Data Exchange (ETDEWEB)

    Diaz-Guerra, J. P.

    1981-07-01

    A method allowing the determination of trace quantities of Hf, Mo, Nb, Ta, Ti, Vi and Zr in sodium metal previous transformation into Na{sub 2}S0{sub 4} is described. The enrichment of the impurities is performed through a coprecipitation technique in sulfuric medium by using Fe{sup 3}+ as a collector and cupferron or phenyfluorone as the precipitating reagent. The matrix influence and the best concentration of the collector (10/{mu}/ml), adequate pH (1,3 or 4, respectively) and optimum filter type (Millipore BSWP02500 or BDWP04700, respectively) have been studied, as well as the precipitation recoveries corresponding to the reagent above. It has been demonstrated the batter efficiency of the cupferron for determining all the Impurities. Detection limits range from 0.01 to 0.2 ppm., depending on the element, for samples 4 g in weight. An automatic spectrometer attached to a 16 K minicomputer and X-ray tube with a gold anode (2250-2700 W) are used. The Interferences between the lines ZrK{alpha} (2{sup n}d order) - HfL{alpha} and TiK{beta} - VK {alpha} have been studied and the respective correction coefficients have been deduced. (Author) 8 refs.

  11. Study of the analytic quality in the determinations of Cr, Fe, Mn, Cu, Zn, Pb and Hg through conventional and nuclear analytical techniques in mosses of the MATV; Estudio de la calidad analitica en las determinaciones de Cr, Fe, Mn, Cu, Zn, Pb y Hg a traves de tecnicas analiticas nucleares y convencionales en musgos de la ZMVT

    Energy Technology Data Exchange (ETDEWEB)

    Caballero S, B.

    2013-07-01

    To evaluate the environmental risks of air pollution and to facilitate the decision-making for control, is necessary to have the capacity to generate data with analytical quality. A comparison between nuclear (Neutron activation analysis and total reflection X-ray fluorescence spectrometry) and no nuclear analytical techniques (atomic absorption spectrometry and inductively coupled plasma optical emission spectrometry) for simultaneous determination of metal content (Cr, Cu, Fe, Hg, Mn, Pb and Zn) in mosses from Metropolitan Area of the Toluca Valley (MATV) was performed. Epiphytic mosses (Fabriona ciliaris and Leskea angustata) were sampled in two campaigns, 16 sites (urban, transition and natural) and were prepared for each technique. The biological certified reference materials were used for the quality control and to evaluate accuracy, precision, linearity, detection and quantification limits. Results show that nuclear analytical techniques and no nuclear applied in chemical analysis of Cr, Cu, Fe, Hg, Mn, Pb and Zn in moss from MATV are comparable and therefore all of these can potentially be used for this purpose. However, if its considered both, the performance parameters and economic/operational characteristics is widely recommended inductively coupled plasma optical emission spectrometry, conventional analytical technique, which showed the highest analytical grade quality. Also were observed spatial and temporal variations in the concentrations of Cr, Cu, Fe, Hg, Mn, Pb and Zn in mosses from MATV and was discussed its potential origin. The urban sites had the highest concentration of anthropogenic elements as Cr, Cu, Fe, Hg, Pb and Zn because are strongly impacted by roads with high vehicle traffic. (Author)

  12. Optimization of methodology by X-ray fluorescence for the metals determination in aquatic plants of the high course of the Lerma river; Optimizacion de la metodologia por fluorescencia de rayos X para la determinacion de metales en plantas acuaticas del curso alto del Rio Lerma

    Energy Technology Data Exchange (ETDEWEB)

    Albino P, E.

    2015-07-01

    The high course of the Lerma river has a pollution problem in its hydrological system due to discharges of urban wastewater and industrial areas; the pollutants that affect the hydrological system are metals, which are absorbed by living organisms and probably incorporated into the food chain. For this reason in this work the technique of X-ray fluorescence total reflection was applied in six species of aquatic plants that grow in the high course of the Lerma river: Arroyo Mezapa (Eichhornia crassipes, Juncus efusus, Hydrocotyle, Schoenoplectus validus) Ameyalco river (Lemna gibba) and Atarasquillo river (Berula erecta) in order to evaluate the metals concentration (Cr, Mn, Fe, Ni, Cu, Zn and Pb) as well as the translocation factor and bioaccumulation factor for each aquatic species. According to the results, was observed that the highest concentration of metals is located in the deeper parts; metals which present a significant concentration are Mn and Fe in the six species of aquatic plants. According to the translocation factor the species having a higher translocation of metals are: Juncus efusus in Mn (1.19 mg/L) and Zn (1.31 mg/L), Hydrocotyle (1.14 mg/L), the species Eichhornia crassipes not show translocation. For bioaccumulation factor, was observed that the most bioaccumulation of metals is found in the soluble fraction of the six species of aquatic plants, especially Fe followed of Cu and Zn. Also was considered that the Berula erecta plant had a higher bioaccumulation of metals such as Cr, Mn, Fe, Cu and Zn so it can be considered as a hyper-accumulating species of these elements. With the results can be considered that the technique of X-ray fluorescence total reflection is 95% reliable to determine the concentration of metals within the structures of the aquatic plants used for this study. (Author)

  13. Uses of complexone III and ion exchange resins in colorimetric determination with o-phenanthroline of Fe traces in uranium compounds; Aplicacion de la complexona III y resinas combadoras a la determinacion colorimetrica con orto-fenantro-lina de trazas de dhierro en compuesto de uranio

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez Cellini, R.; Ruiz Sanchez, F.

    1956-07-01

    The determination of small quantities of iron using o-phenanthroline, assumes the elimination of some cations interference by means of pH control before the formation of a coloured complex. We have eluded that difficulty by the connected action of complexones III and ion exchange. the previous forms quelate with the iron (III) with a stability constant high enough to permit the pass of an iron solution through a cation resin column without being fixed which never occurs with the interferer cations. Mercury is the only element with a similar stability, but it has been eliminated previously. (Author) 16 refs.

  14. Determinacion del efecto antiinflamatorio de los extractos hexánicos, etanólicos y clorofórmicos de las plantas medicinales: Bursera aloexylon, Amphypteryngium adstringens, Tilia mexicana, Verbascum thapsus, Rosmarinus officinalis, Salvia hispanica, Aloe vera, Opuntia ficus-indica en un modelo animal

    OpenAIRE

    Baez Castillo, Glenda

    2007-01-01

    En el presente trabajo se evaluó el efecto antiinflamatorio de los extractos hexánico, de etanólico y de clorofórmico de las siguientes plantas medicinales del estado de Puebla: Bursera aloexylon (linaloe), Amphypterygium adstringens (cuachalalate), Tilia mexicana (tila), Verbascum thapsus (gordolobo), Rosmarinus officinalis (romero), Salvia hispanica (chía), Aloe vera (sábila), Opuntia ficus-indica (nopal). La planta seca y molida (100g) se dejó macer...

  15. Determination of the state of operating mechanical stresses acting on surface piping with problems of differential collapses in the Venta de Carpio Terminal; Determinacion del estado de esfuerzos mecanicos actuantes en tuberias superficiales con problemas de hundimientos diferenciales en la Terminal Venta de Carpio

    Energy Technology Data Exchange (ETDEWEB)

    Neri B, Ernesto R; Garcia E, Nairoby [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2004-07-01

    The Venta de Carpio Terminal is located in the Northern part of the old Texcoco Lake, State of Mexico, in highly compressible soil. In it, it is received, regulated, measured and distributed natural gas, LP gas and PEMEX Refinacion products that are supplied to distribution terminals of and consumption centers located in the central area of the country, that encompasses the states of Puebla, Tlaxcala, Mexico, Hidalgo, Queretaro and a small part of the Federal District. The construction of the Venta de Carpio station dates from 1960; since then, it has presented important regional settlements, mainly due to the water extraction of the subsoil, that have imposed deformations to the piping systems connected to the surface facilities that have been piloted in the terminal. Equally, other surface piping systems and facilities present deformations by differential settlement between their supports. [Spanish] La Terminal Venta de Carpio se ubica en la parte norte del antiguo Lago de Texcoco, Estado de Mexico, en terreno altamente compresible. En ella, se recibe, regula, mide y distribuye gas natural, gas LP y productos de Pemex Refinacion que se suministran a terminales de distribucion y centros de consumo localizados en el area central del pais, que comprende los estados de Puebla, Tlaxcala, Mexico, Hidalgo, Queretaro y una pequena parte del Distrito Federal. La construccion de la estacion Venta de Carpio data de 1960; desde entonces, se han presentado asentamientos regionales importantes debidos, principalmente a la extraccion de agua del subsuelo, que han impuesto deformaciones a los sistemas de tuberias conectados con las instalaciones superficiales que han sido piloteadas en la terminal. De igual modo, otros sistemas de tuberias e instalaciones superficiales presentan deformaciones por hundimientos diferenciales entre sus apoyos.

  16. Application of the pM{sup '}-pC{sub H} diagrams in the determination of hydrolysis constants of the lanthanides; Aplicacion de los diagramas pM{sup '}-pC{sub H} en la determinacion de las constantes de hidrolisis de los lantanidos

    Energy Technology Data Exchange (ETDEWEB)

    Lopez G, H.; Jimenez R, M.; Solache R, M. [Instituto Nacional de Investigaciones Nucleares, Departamento de Quimica, A.P. 18-1027, 11801 Mexico D.F. (Mexico); Rojas H, A. [Universidad Autonoma Metropolitana, Departamento de Quimica, Area de Quimica Analitica (Mexico)

    2001-07-01

    The pM{sup '}-pC{sub H} diagrams allowed to determine the saturation and non-saturation zones of Lu(OH){sub 3} in solid phase and those were applied for determining the hydrolysis and lutetium solubility constants, using the radioactive isotope Lu-177. The first constant of hydrolysis was also determined by the potentiometric method in absence of solid phase. (Author)

  17. Determination of lutetium (III) hydrolysis constants in the middle of ion force 1M sodium chloride at 303 K; Determinacion de las constantes de hidrolisis del lutecio (III), en medio de fuerza ionica 1M de cloruro de sodio, a 303 K

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez R, M.; Solache R, M.J. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico); Ramirez G, J.J.; Rojas H, A. [Universidad Autonoma Metropolitana-Iztapalapa, Mexico D.F. (Mexico). Dept. de Quimica

    1997-07-01

    With the purpose to complete information about the lutetium (III) hydrolysis constants here is used the potentiometric method to determine those in the middle of ion force 1M sodium chloride at 303 K. (Author)

  18. Determination of hydrolysis constants for gadolinium in ion strength media 2M of NaCl, NaClO{sub 4} and KCl at 303 K; Determinacion de las constanted de hidrolisis del gadolinio en los medios de fuerza ionica 2M de NaCl, NaClO{sub 4} y KCl, a 303 K

    Energy Technology Data Exchange (ETDEWEB)

    Serna M, S.; Jimenez R, M.; Solache R, M. [Instituto Nacional de Investigaciones Nucleares, Departamento de Quimica, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    1999-07-01

    This work was made with the purpose to extend information about the hydrolysis constants of gadolinium (III) in ion strength media 2M of NaCl, NaClO{sub 4}, KCl at 303 K using the potentiometric method for this determination, and analysing starting from those data, the influence of anions and cations. It is concluded that the media which were determined the hydrolysis constants are very important and it is recommended the sodium perchlorate as the more adequate salt for those determinations. Also it was obtained the distribution diagrams of chemical species in each one of the media studied. (Author)

  19. Determination of K{sub ps} and {beta}{sub 1,H} in a wide interval of initial concentrations of lutetium; Determinacion de K{sub ps} y {beta}{sub 1,H} en un amplio intervalo de concentraciones iniciales del lutecio

    Energy Technology Data Exchange (ETDEWEB)

    Lopez-G, H.; Jimenez R, M.; Solache R, M. [ININ. Apdo. Postal 18-1027, Mexico D.F. (Mexico); Rojas H, A. [UAM-I, A.P. 55-534, 09340, Mexico. D.F. (Mexico)

    2006-07-01

    solubility product constants and the first of lutetium hydrolysis in the interval of initial concentration of 3.72 X 10{sup -5} to 2.09 X 10{sup -3} M of lutetium, in a 2M of NaCIO{sub 4} media, at 303 K and under conditions free of CO{sub 2} its were considered. The solubility diagrams (pLu{sub (ac)}-pC{sub H}) by means of a radiochemical method were obtained, and starting from its the pC{sub H} values that limit the saturation and no-saturation zones of the solutions were settled down. Those diagrams allowed, also, to calculate the solubility product constants of Lu(OH){sub 3}. The experimental data to the polynomial solubility equation were adjusted, what allowed to calculate those values of the solubility product constants of Lu(OH){sub 3} and to determine the first hydrolysis constant. The value of precipitation pC{sub H} diminishes when the initial concentration of the lutetium increases, while the values of K{sub ps} and {beta}{sub 1,H} its remain constant. (Author)

  20. A radiochemical procedure for a low-level measurement of ''241Am in environmental samples using a supported functional organo phosphorus extractant; Metodo analitico para la determinacion de ''241Am en muestras biologicas y sedimentos marinos mediante uso de una columna con extractante organico

    Energy Technology Data Exchange (ETDEWEB)

    Gasco, C.; Anton, M. P.; Alvarez, A.; Navarro, N.; Salvador, S.

    1994-07-01

    The transuranides analysis in environmental samples is carried out by CIEMAT using standardized methods based on sequential separation with ionic-exchange resins. The americium fraction is purified through a two-layer ion exchange column and lately in an anion-exchange column in nitric acid methanol medium. The technique is time consuming and the results are not completely satisfactory (low recovery and loss of a-resolution) for some samples. The chemical compound CMPO (octyl(phenyl)-N,N-diisobutyl carbomoylmethyiphosphine oxide) dissolved in TPB (tributyl phosphate) and supported on an inert substrate has been tested directly for ''241Am analysis by a large number of laboratories. A new method that combines both procedures has been developed. The details of the improved procedure are described in this paper. The advantages of its application to environmental samples (urine, faeces and sediments) are discussed. The utilization of standard samples, with americium certified concentrations confirms the reliability of our measurements. (Author) 8 refs.

  1. Polarographic determination of Iodide and Iodate, in Solutions Coming from Aerosols in Fission Products Containment Studies in Nuclear Power Stations; Determinacion Polarografica de Especies de Iodo (Ioduro y Iodato) en Soluciones Procedentes de Aerosoles, para Estudios de Contencion de Productos de Fision en Centrales Nucleares

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez, M.; Ballesteros, O.; Fernandez, M.; Clavero, M.; Gonzalez, A. M. [Ciemat, Madrid (Spain)

    2000-07-01

    A polarographic method is described for the iodine species determination, iodide and iodate in water solutions. the iodate can be determined by differential pulse polarography. Calibration curves and the detection and determination limits have been obtained. Iodides is oxidized to iodate with sodium hypochlorite and the excess of oxidizing agent is destroyed with sodium sulphide. The concentration of iodide is calculated as the difference between the concentration of iodate in the sample before and after the oxidation. As an application, species of iodine in samples coming from the experimental plants GIRS (Gaseous Iodine Removal by Sprays) of Nuclear Fission Department of the CIEMAT, dedicated to fission products containment studies in nuclear power station, were determined. (Author) 10 refs.

  2. Determination of the zero in the Two theta angle and the wavelength in the neutron diffractometer for the Cyber computer of the ININ and for the IBM compatible microcomputers; Determinacion del cero en el angulo Dos teta y la longitud de onda en el difractometro de neutrones para la computadora Cyber del ININ y para microcomputadoras compatibles con IBM

    Energy Technology Data Exchange (ETDEWEB)

    Macias B, L.R

    1991-05-15

    The objective of this work consists on determining the calibration in the angular parameters and the neutron wavelength used in the neutron diffractometer of the TRIGA Mark III reactor, through some readings in that a well-known sample is used by means of a Fortran computer program that is used in the CYBER computer of the ININ in Mexico, and/or in micro computers compatible with IBM. The program was also designed to determine the zero of the 2 {theta} angle of the goniometer of the diffractometer. The generated data were proven by means of well-known data of the Powder Diffraction File of the Joint Committee on Powder Diffraction Standards (JCPDS). (Author)

  3. Determination of experimental conditions for the analysis of rare-earth elements by X-ray fluorescence spectrometry. Application to oxalates and potassium sulphate matrices; Establecimiento de varibles experimentales para la determinacion de tierras raras por espectrometria de fluorescencia de rayos X. Aplicacion a los concentrados de oxalatos y sulfatos

    Energy Technology Data Exchange (ETDEWEB)

    Bayon Fuentes, A.; Bermudez Polonio, J.

    1969-07-01

    A previous theoretical and experimental study is carried out in order to analyze the rare earths elements by X-ray florescence spectrometry. All possible spectral interferences are considered. The working conditions for each element were selected, taking into account the peak/background ratio values for the following parameters: tungsten, molybdenum and chromium targets, current and voltage, analyzing crystals, and scintillation and flow proportional counters. Calibration curves were plotted showing the concentration of rare earths elements in oxalates and potassium sulphate matrices, and the theoretical detection limits for each element: are calculated. (Author) 8 refs.

  4. Left ventricle function in patients with ischemic cardiopathy: determination of the expulsion fraction of the left ventricle with gated-SPECT. Experience in the CMN 20 de Noviembre ISSSTE; Funcion ventricular izquierda en pacientes con cardiopatia isquemica: determinacion de la fraccion de expulsion del ventriculo izquierdo con gated-SPECT. Experiencia en el CMN 20 de Noviembre ISSSTE

    Energy Technology Data Exchange (ETDEWEB)

    Mendoza, L.; Puente, A.; Hernandez, T.; Jimenez, L. [Departamento de Medicina Nuclear y Cardiologia, Hospital CMN 20 de Noviembre, ISSSTE, 03000 Mexico D.F. (Mexico)

    2007-07-01

    The objective of this work is to correlate the expulsion fraction of the left ventricle (FEVI) obtained by means of g-SPECT and other diagnostic methods: ECO 2D and ventriculography for heart catheterization (CTT). (Author)

  5. Thermogravimetric and specific heat determinations of a commercial reconcentrated sample of ulexite, between room temperature and 1,000 degree centigree; Determinaciones termogravimetricas y de calor especifico de un concentrado comercial de ulexita, entre temperature ambiente y 1.000 grados centigrados

    Energy Technology Data Exchange (ETDEWEB)

    Flores, H. R.; Valdez, S. K.

    2006-07-01

    The important amount of hydration water in the ulexite (NaCaN{sub 5}O{sub 9}.8H{sub 2}O), allows using calcination methods to increase its B{sub 2}O{sub 3} content. This paper analyses the thermal decomposition reaction of a preconcentrated ulexite through weight loss measurements, which occur during the heating of samples until 1000 degree centigree, Determinations of heat content at each temperature were made using an isoperibol calorimeter. The mean specific heat was calculated from these values, and its dependence on temperature was determined. The maximum weight loss was about 32.5% and the specific heat obtained was 1,13 kJ/kg 0 C for solid samples and 1,38 kJ/kg''0 C for fluid samples. The results are useful for the design of the industrial process, in order to determine the thermal requirements for heating calcined ulexite, and to obtain smelted ulexite. (Author) 19 refs.

  6. Determination of the hydrolysis constants of Europium (III), in ion strength media 4, 5 and 6 M NaClO{sub 4} at 303 K; Determinacion de las constantes de hidrolisis del Europio (III), en medios de fuerza ionica 4, 5 y 6 M de NaClO{sub 4} a 303 K

    Energy Technology Data Exchange (ETDEWEB)

    Alvarado B, A.; Jimenez R, M.; Solache R, M. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    1999-07-01

    This work was made with the purpose to complete information about the hydrolysis constants of Europium (III) in high ion strength media. So it was determined at a ion forces media 4, 5 and 6 M of sodium perchlorate at 303 K. The method used was the potentiometric with the aid of the Super quad computer program. In high ion strength media, the measurements of p H do not correspond directly to negative logarithm of the concentration of hydrogen ions, by this it is necessary to calibrate the electrode in these conditions. The Europium was hydrolized at pC{sub H} values greater 6 in all cases. The potentiometric method used under the described experimental conditions is adequate to determine the hydrolysis constants of Europium (III). According to the results and diagrams of chemical species of Europium obtained we can conclude that the hydrolysis constants, differ by its distribution but not in its identity. (Author)

  7. Study of the influence of the composition and density of the cement for the determination of the efficiency to the extent of using homogeneous packages ISOCS; Estudio de la influencia de la composicion y densidad del cemento para la determinacion de la eficiencia en la medida de bultors homogeneos mediante ISOCS

    Energy Technology Data Exchange (ETDEWEB)

    Marijuan, M. J.; Suarez-Navarro, J. A.; Esteban-Limenez, M. A.; Quinones, J.

    2013-07-01

    This work has studied the influence of the composition and density of the matrix, so as distance drum-detector in the determination of counting efficiencies, using Canberra [11-13], software ISOCS on drums with homogeneous residues. Also, efficiencies determined experimentally curves have been compared and using such software. The studies were carried out with the drum in a static position and with twist. A container prepared with soil samples was employed for the validation of the technical upgraded in the sample preparation laboratory and measured by the technique of segmented gamma spectrometry and the proposal in this paper. With the studies has established a methodology to determine the efficiency of measurement drums with waste homogeneous with twist.

  8. Radioecological studies at the National Accelerator Centre based on the determination of {sup 1}29I by accelerator mass spectrometry (AMS); Estudios radioecologicos en el Centro Nacional de Aceleradores basados en la determinacion de {sup 1}29I mediante espectrometria de masas con acelerador (AMS)

    Energy Technology Data Exchange (ETDEWEB)

    Lopez-Gutierrez, J. M.; Gomez-Guzman, J. M.; Chamizo, E.; Santos, F. J.; Garcia-Leon, M.; Garcia-Tenorio, R.

    2013-07-01

    Since 2006 a compact system of mass spectrometry with Accelerator (AMS) is installed at the National Center of Accelerators, Seville. After an initial set-up and study have been opening many lines of research in fields such as archeology, geology, paleontology, oceanography, oceanography, internal dosimetry and characterization of radioactive waste, among others. In particular, based on the measurement of {sup 1}29I have made contributions to the field of radioecology and radiation protection. In this work they are summarized and presented some of these investigations. (Author)

  9. Procedure Development to Determine Organic Compounds in the PM{sub 1}-2.5 and PM{sub 2}.5-10 Fractions of Atmospheric Aerosols; Desarrollo de la Metodologia para la Determinacion de los Compuestos Organicos en las Fracciones PM{sub 1}-2.5 y PM{sub 2}.5-10 del Aerosol Atmosferico

    Energy Technology Data Exchange (ETDEWEB)

    Pindado, O.; Perez, R. M.

    2011-07-28

    An analytical procedure development to measure organic compounds such as aliphatic hydrocarbons, polycyclic aromatic compounds, n-alcohols and fatty acids in PM{sub 1}-2.5 and PM{sub 2}.5-10 of atmospheric aerosol is accomplished. The development encompasses an optimization of extraction step, derivatization step and chromatographic analysis. The method developed consists in a microwave extraction, followed by a stage of fractionation and analysis by GC/MS. (Author) 20 refs.

  10. Determination of the adaptive response induced In vivo by gamma radiation and its relation with the sensibility to the damage induction in the DNA and with the repairing capacity; Determinacion de la respuesta adaptativa inducida In vivo por radiacion gamma y su relacion con la sensibilidad a la induccion de dano en el ADN y con la capacidad de reparacion

    Energy Technology Data Exchange (ETDEWEB)

    Mendiola C, M.T

    2002-07-01

    The kinetics of damage induction and repair at different doses as well as the adaptive response induced by gamma ray exposure were determined in murine leukocytes in vivo. The damage-repair kinetics were established after the exposure to 0.5, 1.0 or 2.0 Gy in a {sup 137}Cs source. Peripheral blood samples were obtained from the tails of mice, the percentage of damaged cells and the DNA migration in each one were analyzed by the single cell gel electrophoresis (SCG) technique or comet assay. Results indicated that there was an induction of approximately 75% comets with the doses of 1.0 and 2.0 Gy, which was considerably reduced to 22% and 42% respectively during the first 15 minutes. This evidences the presence of a rapid repair process and suggests that leucocytes are genetically well prepared to repair this kind of damage. After 15 minutes, a second increase in the percentage of damaged cells that was proportional to dose occurred, which seems to represent the breaks produced during the repair of other kind of lesions. After that a second reduction was observed, reaching values near to the basal ones, except with the dose of 2.0 Gy. The kinetics obtained with the dose of 0.5 Gy was similar to that established with 1.0 Gy, but in this case the initial damage was 50 % lower. Besides, the adaptive response was observed after the exposure of the mice to an adaptive dose of 0.01 Gy and to a challenge dose of 1.0 Gy 60 minutes later. The pretreatment reduced the percentage of damaged cells caused by the challenge dose to one third approximately, and also diminished this parameter produced during the late repair process. This indicates that the early adaptive response is caused, instead of by an increment in repair, by the induction of a process that protects DNA from damage induction by radiation, i.e synthesis of substances that increase the scavenging of free radicals. (Author)

  11. Determination of {sup 60} Co by means of Neutron Activation Analysis in the sorption of Co in synthesized porous oxides by the combustion method; Determinacion de {sup 60} Co por medio de AAN en la sorcion de Co en oxidos porosos sintetizados por metodo de combustion

    Energy Technology Data Exchange (ETDEWEB)

    Lugo, V.; Bulbulian, S.; Urena, F. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)]. e-mail: violelugo@yahoo.es

    2005-07-01

    Recently inorganic materials are investigating as sorbent of radioactive pollutants present in water. The inorganic oxides belong to this group of materials. A quick method exists for the obtaining of inorganic oxides, denominated combustion method that could be used to produce porous oxides successfully with good properties for the sorption of radioactive ions. In this investigation, iron oxides, magnesium and zinc were synthesized obtained by the combustion method, comparing them with those synthesized by the calcination method, using two different synthesis temperatures. The obtained solids were characterized by scanning electron microscopy (Sem), by X-ray diffraction (XRD) and by semiquantitative elemental analysis (EDS). After the characterization, the crystalline oxides synthesized by both methods, to temperature of 800 C, were evaluated as sorbents in the removal of Co{sup 2+} ions, through experiments in batch, and using neutron activation analysis, determining the sorption percentage, with this it was concluded that the magnesium oxide produced by combustion it is more effective in the removal of Co{sup 2+} ions than that synthesized by calcination. It was determined the surface area of the magnesium oxides, obtaining a surface area greater for the synthesized oxide by combustion method. (Author)

  12. Neural network design with combined backpropagation and creeping random search learning algorithms applied to the determination of retained austenite in TRIP steels; Diseno de redes neuronales con aprendizaje combinado de retropropagacion y busqueda aleatoria progresiva aplicado a la determinacion de austenita retenida en aceros TRIP

    Energy Technology Data Exchange (ETDEWEB)

    Toda-Caraballo, I.; Garcia-Mateo, C.; Capdevila, C.

    2010-07-01

    At the beginning of the decade of the nineties, the industrial interest for TRIP steels leads to a significant increase of the investigation and application in this field. In this work, the flexibility of neural networks for the modelling of complex properties is used to tackle the problem of determining the retained austenite content in TRIP-steel. Applying a combination of two learning algorithms (backpropagation and creeping-random-search) for the neural network, a model has been created that enables the prediction of retained austenite in low-Si / low-Al multiphase steels as a function of processing parameters. (Author). 34 refs.

  13. Study of New Analytical Methodologies for the Analysis of Polychlorinated Dibenzo-P-Dioxins (PCDDs) and Polychlorinated Di benzofurans (PCDFs) by Quadrupole Ion Storage Tandem-in-time Mass Spectrometry. Application to Environmental Samples; Estudio de nuevas metodologias analiticas en la determinacion de policlorodibenzo-P-dioxinas (PCDDs) y policlosrodibenzofuranos (PCDFs) por espectrometria de masas con trampa ionica. Aplicacion a muestras medioambientales

    Energy Technology Data Exchange (ETDEWEB)

    Sanz Chichon, M. P.

    2008-07-01

    Two alternative analytical methodologies have been developed for the analysis of polychlorinated dibenzo-p-dioxins (PCDDs) and di benzofurans (PCDFs) in environmental samples. The techniques studied have been: Pressurized Fluid Extraction (PFE) and Microwave-Assisted Extraction (MAE) versus Soxhlet extraction; the automated system Power-PrepTM versus the conventional cleanup using open chromatographic columns with different adsorbents and the application of tandem mass spectrometry (HRGC-MS/MS) versus high resolution mass spectrometry (HRGC-HRMS) for PCDD/Fs detection and quantification. (Author) 233 refs.

  14. Measurement of the mass of mercury in electrolytic cells of Chemical Industry of the Istmo s. a. of c. v. Coatzacoalcos Plant, Ver. (Mexico); Determinacion de la masa de mercurio en celdas electroliticas de Industria Quimica del Istmo s. a. de c. v. Planta Coatzacoalcos, Ver

    Energy Technology Data Exchange (ETDEWEB)

    Angeles C, A.; Vizuet G, J.; Herrera M, J. M.; Flores M, J

    2001-01-15

    For the industry of the production of caustic soda and chlorine is commonly use electrolytic cells with mobile electrode of mercury; in the process it gets lost mass, and there is necessity to know the quantity of mercury that exists in each cell. To know the periodic levels of mercury in the 40 electrolytic cells of the Plant of Coatzacoalcos, in the State of Veracruz (Mexico), the investigators of the ININ used the technique of isotopic dilution by mean of the radioactive injection of a radioactive tracer.(Author)

  15. A empiric expression to interpret the approximation of {lambda} cI phages to E. coli C{sub 6}00 bacteria; Determinacion experimental de la cinetica de laproximacion del fago /{lambda}cl a la bacteria E. coli C{sub 6}00 Expression empirica interpretativa del proceso

    Energy Technology Data Exchange (ETDEWEB)

    Garces, F.; Vidania, R. de

    1984-07-01

    In general the process of adsorption of phages to bacteria is considered in the bibliography as an statistical process. In this work we use an empiric expression which allows to interpret the approximation of {lambda}cI pages to E. coli C{sub 6}00 bacteria. This expression introduces some changes respect to a pure statistical description of the approximation process. (Author) 26 refs.

  16. Implementation of a constant load method, for determination of crack growth velocities in MEX-03 system of National Institute of Nuclear Research; Implementacion de un metodo de carga constante, para la determinacion de velocidades de crecimiento de grieta en el sistema MEX-03 del ININ

    Energy Technology Data Exchange (ETDEWEB)

    Diaz S, A.; Fuentes C, P.; Merino C, F. [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)], e-mail: angeles.diaz@inin.gob.mx

    2009-10-15

    Whit the objective of to complete the existent techniques for susceptibility evaluation to phenomenon of stress corrosion cracking in laboratories of Applied Sciences Area of National Institute of Nuclear Research; was realized and documented the modification of a high pressure and temperature equipment, identified as MEX-03 to carry out the implementation of a growth and crack propagation assay, using a constant load method. The assay was realized to a specimen of stainless steel AISI 304l type CT of an inch, which was previously thermally sensitize, simulating the typical degradation of this materials type below operation conditions in a BWR. The MEX-03 system, consist from an annexed auto key to a load system which originally was controlled by displacement; therefore were carried out modifications to achieve the control by load. The realized adjustments allowed to maintain a constant load during all the experiment, and as much the temperature conditions (T = 288 C) as of pressure (P = 8 Mpa) were controlled during the assay realization. The steel was exposed to a conditioned ambient with hydrogen gas addition; simulating a well-known alternative chemistry as hydrogen water chemistry that is used to mitigate the phenomenon of stress corrosion cracking, main degradation mechanism of austenitic stainless steels. The continuation of the crack behavior was realized by means of electric potential fall technique and later was validated of visual form through the fractographic analysis of cracked surface. The modification and control of equipment for realization of this experiment is necessary, for what should be carried out new assays, whose results will allow to establish the effect of dynamic and static methods in velocity determination of crack growth to laboratory level; to be considered in the existent models of crack propagation in systems and components in operation. (Author)

  17. Multi-elemental analysis of atmospheric pollutants and determination of particle size using the PIXE method, a cascade impactor and a filter unit constructed in Mexico; Analisis multielemental de contaminantes atmosfericos y determinacion de tamano de particula utilizando el metodo PIXE, un impactor de cascada y una unidad de filtro construidos en Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Aldape U, F. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    1989-01-15

    This work presents: 1) The methodology and the experimental conditions of the PIXE technique so that it is used as a better option inside the analytical methods in aerosols studies, 2) The development, tests and applications of a cascade impactor of the Batelle type built to determine particle size to use it jointly with the mentioned technique in the determination of the elements concentration according to its size.By this way is fulfilled with the first goal of this extensive project. (Author)

  18. Recommended values of the humidity correction factor k{sub n} for determining exposure in an X-ray beam with free-air chambers; Valores recomendados del factor de correccion por humedad, k{sub h} para la determinacion de la exposicion en un haz de rayos X usando camaras de paredes de aire

    Energy Technology Data Exchange (ETDEWEB)

    Los Arcos, J.M.; Brosed, A.

    1983-07-01

    The experimental values stated by CCEMRI (Section I) concerning the humidity correction factor k{sub h} required for determining exposure in an X-ray beam with free-air chambers are commented and a method to estimate k{sub n} numerically, at any particular combination of relative humidity, pressure and temperature, la explained. A table of k{sub h}, calculated for relative humidity varying from 0% to 90%, for pressures in the range of 70 kPa to 104kPa and temperatures between 15 degree centigree and 30 degree centigree, is included. (Author) 10 refs.

  19. Experimental aspects of stress-strain curves determination at high temperature and controlled atmosphere: Al{sub 2}O{sub 3}-MgO-C refractories; Aspectos experimentales de la determinacion de curvas esfuerzo-deformacion a alta temperatura y en atmosfera controlada: Refractarios Al{sub 2}O{sub 3}-MgO-C

    Energy Technology Data Exchange (ETDEWEB)

    Munoz, V.; Rohr, G. A.; Tomba Martinez, A. G.; Cavalieri, A. L.

    2011-07-01

    A methodology for the mechanical evaluation of refractory materials at high temperatures and controlled atmosphere, designed and implemented in the Structural Materials Laboratory of Ceramics Division of INTEMA, is described. The methodology includes the measurement of the specimen deformation by contact extensometry in compression tests to obtain stress-strain curves and the use of a gaseous flow as a system to control atmosphere. The determination of stress-strain curves of Al{sub 2}O{sub 3}-MgO-C commercial refractories used in steelmaking ladles at room temperature and 1260 degree centigrade in different atmospheres is presented as an example of application of this methodology. (Author) 34 refs.

  20. Utility of the tetrophosmine-{sup 99m}Tc in the determination of malignant tumours located in the muscle-skeletal system, preliminary report; Utilidad de la tetrofosmina-{sup 99m}Tc en la determinacion de malignidad de tumores localizados en el sistema musculoesqueletico, reporte preliminar

    Energy Technology Data Exchange (ETDEWEB)

    Garcia R, J.C.; Gonzalez, I.F.; Rico, G.; Linares, L.M.; Delgado C, E.; Baena, L. [Centro Nacional de Rehabilitacion, Mexico D.F. (Mexico); Adame, G.; Gonzalez R, D. [MIYMSA, Mexico D.F. (Mexico); Perez C, J.P.; Valencia, S. [Hospital medica Sur, Mexico D.F. (Mexico)

    2005-07-01

    From its authorization by the FDA, as radiopharmaceutical to be used in studies of myocardial perfusion, multiple articles have appeared in the literature it prescribes that its validate the use of the tetrophosmine-{sup 99m}Tc in the valuation of different tumors, so much in the determination of malignancy, like in the evolution and in the response to the treatment. For that reason the objective of this protocol is to evaluate the utility of the tetrophosmine- {sup 99m}Tc in the determination of malignancy in non treated tumors located in the skeletal muscle system, in a population of 40 patients coming from the service of bony tumors of the National Center of Rehabilitation. For the time being its report the discoveries in 27 studies. (Author)

  1. Determination of Rn{sup 222} in samples of well water and domicile of the cities of Chihuahua and Aldama, Mexico; Determinacion de Rn{sup 222} en muestras de agua de pozos y domicilio de las ciudades de Chihuahua y Aldama, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Villalba, L.; Colmenero S, L.; Montero C, M.E. [Centro de Investigacion en Materiales Avanzados (CIMAV), Av. Miguel de Cervantes Saavedra 120, 31109 Chihuahua (Mexico)]. e-mail: lourdes.villalba@cimav. edu. mx

    2004-07-01

    The study of the content of dissolved Rn{sup 222} is presented in underground water and of domicile of the cities of Chihuahua and Aldama of the State of Chihuahua. The existence of the Rn{sup 222} in the underground waters comes from its constant production in the rocks of the terrestrial bark. It has been determined that the radon is a noble gas of more solubility in the water, this solubility induces high concentrations in underground water, as well as bigger risk to the health in the human body once ingested or inhaled. Of the 32 wells studied in the cities of Chihuahua and Aldama, the content of dissolved Rn{sup 222} in the water of 22 of them is bigger than 11 Bq/l and of 73 studied samples of water of domiciles 47 show bigger values that 11 Bq/l. These radon contents are attributable to the uraniferous rocks present in the aquifers. (Author)

  2. Sensitivity analysis of the influence of the medium energy and initial fluence FWHM of electron determining a Bremsstrahlung photon spectrum of a linear accelerator; Analisis de sensibilidad de la influencia de la energia media FWHM de la influencia inicial de electrones en la determinacion de un espectro de fotones Bremsstrahlung de un acelerador lineal

    Energy Technology Data Exchange (ETDEWEB)

    Juste, B.; Miro, R.; Verdu, G.; Diez, S.; Campayo, J. M.

    2012-11-01

    A correct dose calculation in patient under radiotherapy treatments requires and accurate description of the radiation source. The main goal of the present work is to study the effects of initial electron beam characteristics on Monte Carlo calculated absorbed dose distribution for a 6 MeV linac photon beam. To that, we propose a methodology to determine the initial electron fluence before hitting the accelerator target for an Elektra Precis a medical linear accelerator. The method used for the electron radiation source description is based on a Software for Uncertainty and Sensitivity Analysis (SUSA) and Monte Carlo simulations using the MCNP5 transport code. This electron spectrum has been validated by means of comparison of its resulting depth dose curve in a water cube with experimental data being the mean difference below the 1%. (Author)

  3. Sensitivity analysis the influence of the average energy and FWHM of the initial fluence electrons in the determination of a spectrum of photons Bremsstrahlung of a linear accelerator; Analisis de sensibilidad de la influencia de la energia media y FWHM de la fluencia inicial de electrones en la determinacion de un espectro de fotones Bremsstrahlung de accelerador lineal

    Energy Technology Data Exchange (ETDEWEB)

    Justo, B.; Miro, R.; Verdu, G.; Diez, S.; Campayo, J. M.

    2011-07-01

    The main objective of this work is to study the effects of the initial beam characteristics of electrons in the absorbed dose distribution calculated by Monte Carlo for a photons beam of 6 MeV emitted by a medical linear accelerator.

  4. Development of an analytical model for the determination of {sup 60}Co in aqueous samples by atomic absorption and gamma spectrometry techniques; Elaboracion de un modelo analitico para la determinacion de {sup 60}Co en muestras acuosas mediante tecnicas de absorcion atomica y espectrometria gamma

    Energy Technology Data Exchange (ETDEWEB)

    Solis A, N. A.

    2015-07-01

    The applications of the nuclear energy in industry and medicine generate radioactive wastes that must be isolated and confined in order to limit its spread in the biosphere. These types of wastes are generated in hospitals, industry, research centers and nuclear power plants (during de fuel cycle). The radioactive elements (radionuclides) cannot be destroyed by any known method, either chemical or mechanical. Its final destruction is produced by radioactive decay, which makes them stable isotopes, or nuclear transmutation being bombarded with atomic particles. Consequently, the radioactive waste management is to control the radioactive discharges and reduce to tolerable limits, eliminating of effluents and wastes the radionuclides of interest, concentrating them so they can be stored or evacuated so that later not appear in dangerous concentration in the biosphere. In Mexico, the main generators of radioactive wastes are the nuclear power plant of Laguna Verde in Veracruz, Hospitals of the public and private sector, in addition Instituto Nacional de Investigaciones Nucleares (ININ) some institutes and facilities of the UNAM and Instituto Politecnico Nacional (IPN) and industries among others. The aqueous radioactive wastes, particularly those from the nuclear power plants contain traces of cobalt-60. Currently there is no model or analytical technique for the separation of this radionuclide, so it became necessary to develop an analytical model for separation and facilitate their disposal. In this paper was shown that atomic absorption and gamma spectrometry techniques can separate the active concentration of the inactive, which is important because the total concentration can be associated through direct relationships with the wear of metal parts of the nuclear reactor, since the metal alloys of the same reactor containing a fraction of cobalt. Also this analytical and mathematical model that can be reproducible and applicable to full sets of samples and that this correlation can be interpreted graphically to obtain approximate values for active or inactive cobalt concentration. (Author)

  5. Determination of the extractive capacity of para-tert butyl calix[8]arene octa-phosphinoylated towards uranyl ions from an aqueous-acidic-salty medium; Determinacion de la capacidad extractiva del p-ter-butilocalix[8]areno octa-fosfinoilado hacia iones uranilo de un medio acuo-acido salino

    Energy Technology Data Exchange (ETDEWEB)

    Serrano V, E. C.

    2011-07-01

    The extraction properties of octa-phosphinoylated para-tert butyl calix[8]arene (prepared in the laboratory) in chloroform towards uranyl ions from an aqueous-acidic-salty medium (HNO{sub 3}-3.5 NaNO{sub 3}) containing uranyl nitrate salt, was investigated. Two spectroscopic techniques UV/Vis and Luminescence were used for this study. The latter permitted analyze the fluorescence from the uranyl ions influenced by the surrounding medium. Both permitted to learn about the power of this calixarene as extractant towards the mentioned ions. Its extraction ability or capability using this calixarene at 5.91 x 10{sup -4} M towards the uranyl ions was 400% as determined by UV/Vis while fluorescence revealed 100% of uranyl ion extraction. A closed analysis of the results obtained by using these techniques revealed that the stoichiometry of the main extracted species was 1calixarene:2 uranyl ions. The loading capacity of the calixarene ligand towards the uranyl ions was also investigated using both techniques. UV/Vis resulted to be inadequate for quantifying exactly the loading capacity of the calixarene whereas luminescence was excellent indeed, using a 5.91 x 10{sup -4} M calixarene concentration, its loading capacity was 0.157 M of free uranyl ions from 0.161 M of uranyl ions present in the aqueous-acidic-salty medium. The extracts from the ability and capacity studies were concentrated to dryness, purified and the dried extracts were analyzed by infrared and neutron activation analysis. By these techniques it was demonstrated that during the extraction of the uranyl ions by the calixarene ligand they form thermodynamically and kinetically stable complexes, since in the solid state, the 1:2, calixarene; uranyl ions stoichiometry was kept with the minimum formula: (UO{sub 2}){sub 2}B{sub 8}bL{sup 8}(NO{sub 3}){sub 4}(H{sub 2}O){sub 4}CHCl{sub 3}(CH{sub 3}OH){sub 3} the methanol molecules come from its purification. It is proposed that B{sub 8}bL{sup 8} calixarene in chloroform medium is a good extractant for the treatment of nuclear wastes or radioactive wastes containing uranium in a rich aqueous-acidic-salty medium. (Author)

  6. Study of an X-ray fluorescence thin film method for the determination of uranium in low activity solutions; Estudio de un metodo de fluorescencia de rayos X en capa delgada para la determinacion del uranio en soluciones de baja actividad

    Energy Technology Data Exchange (ETDEWEB)

    Diaz-Guerra, J. P.

    1980-07-01

    The application of the X-ray fluorescence thin film technique to the uranium determination in nitric solutions for a concentration range from 1 g/l to 100 g/l and activity levels under 5 mCi/ml is studied. The most suited excitation and measurement conditions are also studied and the uranium matrix effect correction, which is performed through the double dilution, {alpha}{sub U}U interaction coefficient calculation and internal standard methods, is discussed. The specimen preparation is satisfactorily accomplished by using P.V.C. filters fixed on aluminium supports. (Author) 18 refs.

  7. Determination of the dose equivalent Hp(0.07) in hands of occupationally exposed personnel in the practice of proton emission tomography (PET/CT); Determinacion de la dosis equivalente Hp(0.07) en manos de trabajadores ocupacionalmente expuestos en la practica de Tomografia por Emision de Positrones (PET/CT)

    Energy Technology Data Exchange (ETDEWEB)

    Lea, D. [Servicio de Radiofisica Sanitaria, Unidad de Tecnologia Nuclear, Instituto Venezolano de Investigaciones Cientificas, Ministerio de Ciencia y Tecnologia, Km 11 Carretera Panamerican, Altos del Pipe, Caracas (Venezuela); Ruiz, N.; Esteves, L. [Centro Diagnostico Docente Las Mercedes, Calle Paris cruce con calle Caroni, Edif. CDD, Las Mercedes, Caracas (Venezuela)]. e-mail: dlea@ivic.ve

    2006-07-01

    In Venezuela recently it was implanted the Positron Emission Tomography technique (PET) with the perspective of implanting it at national level. Even when in our country practices it of nuclear medicine it exists from early of 70, there is not experience in the determination of the occupational doses by exposure to the external radiation in hands. By this reason, a concern exists in the workers of the centers of nuclear medicine where it is practiced the Positron Emission Tomography technique. In absence of the TLD dosimetry to measure dose in hands in our country, measurements of the dose equivalent of the workers of the PET national reference center were made, using a detector of hands type diode. It was determined the dose in hands in terms of dose equivalent Hp(0.07) in two work positions, that is: the corresponding to the transfer of the receiving vial of ({sup 18}F) FDG to the shield, quality control and uni doses division. The second work position corresponds the person in charge of administering, via intravenous, the ({sup 18}F) FDG. In this work it realizes the dose equivalent in hands Hp(0.07) measures in each one of the work positions before described by daily production. The informed doses correspond to a total average produced activity of 20.4 GBq (550 mCi). The results of the measurements in terms of dose equivalent in hands Hp(0.07) correspond to 2.1 {+-} 20% mSv in the work position of division and 0.4 {+-} 10% mSv in the position of injection of the radioactive material. At short term this foreseen until 4 productions per week, what means an annual dose equivalent Hp(0.07) in hands of 400 mSv approximately, without taking into account abnormal situations as its are spills of the ({sup 18}F) FDG in the work place. This work is the starting point so that the regulatory authority settles down, in Venezuela, dose restrictions in the PET practices and implant, in the centers of nuclear medicine, an optimization politics of this practice in conformity with the ALARA principle. (Author)

  8. Determination of the sensitization of two coatings by steel welding 308l by the EPR-Dl and Astm A-262 practice A techniques; Determinacion de la sensibilizacion de dos revestimientos por soldadura de acero 308L por las tecnicas EPR-DL y ASTM A-262 practica A

    Energy Technology Data Exchange (ETDEWEB)

    Arganis J, C. R.; Zenteno S, J. C.; Robles F, J. L.; Rodriguez M, E.; Vazquez P, A., E-mail: carlos.arganis@inin.gob.mx [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2014-10-15

    A stainless steel 308l coating was deposited by the shielded metal arc welding (SMAW) on steel A36 with a thickness of 4.726 mm in three layers. The sensitization was measured with the technique of Electrochemical Potentiodynamic Reactivation of Double-loop (EPR-Dl), using a portable cell and other of conventional window. The standard Astm A-262, practice A was used to verify the sensitization values. Two samples were used, a welding on a plate of 323 x 172 x 76.2 mm and the second welding on the end of a plate of 12.7 mm of thickness and 280 mm of longitude, with a post-welding process with gas tungsten arc welding (GTAW) with electrode ERNiCr{sub 3} and a process SMAW with electrode ENICRFe{sub 3}. The coating on the plate showed low values of sensitization grade (DOS) in all the points, indicating a very quick heat extraction and an inter dendritic structure type step. The second sample presented DOS values that are related with a structure of low sensitization and the influence of the heat of the post-welding process and a structure of recrystallized grains. (Author)

  9. Determination of the exposition rapidity in the level 49.90 of the reactor building for the decrease in the water level of the spent fuel pool; Determinacion de la rapidez de exposion en el nivel 49.90 del edificio del reactor por la disminucion en el nivel de agua de la alberca de combustible gastado

    Energy Technology Data Exchange (ETDEWEB)

    Mijangos D, Z. E.; Herrera H, S. F.; Cruz G, M. A.; Amador C, C., E-mail: zoedelfin@gmail.com [Comision Federal de Electricidad, Central Nucleoelectrica Laguna Verde, Subgerencia de Ingenieria, Km 44.5 Carretera Cardel-Nautla, 91476 Laguna Verde, Alto Lucero, Veracruz (Mexico)

    2014-10-15

    The fuel assemblies storage in the nuclear power plant of Laguna Verde (NPP-L V) represents a crucial aspect, due to the generated dose by the decay heat of the present radio-nuclides in the assemblies retired of the reactor core, after their useful life. These spent assemblies are located inside the spent fuel pool (SFP), in the level 49.90 m in the Reload Floor of the Reactor building of NPP-L V. This leads to the protection at personnel applying the ALARA (As Low As Reasonably Achievable) criteria, fulfilling the established dose criteria by the Regulator Body the Comision Nacional de Seguridad Nuclear y Salvaguardias (CNSNS). Considering the loss scenario of the cooling system of the SFP, in which the SFP water vaporizes, is important to know the water level in which the limit of effective dose equivalent is fulfilled for the personnel. Also, is important for the instrumentation of the SFP, for the useful life of the same instruments. In this work is obtained the exposition rapidity corresponding to different water levels of SFP in the Reload Floor of NPP-L V, to identify the minimum level of water where the limit of effective dose equivalent is fulfilled of 25 rem s to the personnel, established in the Article 48 of the General Regulation of Radiological Safety of CNSNS and the Chapter 50 Section 67 of the 10-Cfr of Nuclear Regulatory Commission in USA. The water level is also identified where the exposition rapidity is of 15 m R/hr, being the value of the set point of the area radiation monitor D21-Re-N003-1, located to 125 cm over the level 49.90 meters of the Reload Floor of NPP-L V. (Author)

  10. Upgrade in the CNSNS of the determination process about the importance for the impact evaluation to the safety of defaults or violations in the national nuclear facilities; Actualizacion en la CNSNS del proceso de determinacion de la importancia para la evaluacion de impacto a la seguridad de incumplimientos o violaciones en las instalaciones nucleares mexicanas

    Energy Technology Data Exchange (ETDEWEB)

    Espinosa V, J. M.; Jauregui Ch, V., E-mail: jmespinosa@cnsns.gob.mx [Comision Nacional de Seguridad Nuclear y Salvaguardias, Dr. Barragan No. 779, Col. Narvarte, 03020 Mexico D. F. (Mexico)

    2014-10-15

    Inside the process of Impact Evaluation to the Safety of the Direccion General Adjunta de Seguridad Nuclear of the Comision Nacional de Seguridad Nuclear y Salvaguardias (CNSNS) the Significance Determination Process (SDP) is used, developed by the United States Nuclear Regulatory Commission (US NRC), to evaluate the violations or defaults to the regulatory framework and to determine its importance to the risk by means of a fixed color: Green (Very low impact to the safety), White (Low impact to moderate to the safety), Yellow (Substantial impact to the safety) or Red (High impact to the safety). All this inside the seven safety foundations of the Reactor Oversight Process: Initiator Events, Mitigation Systems, Integrity of the Barriers, Preparation for Emergencies, Occupational Radiological Safety, Radiological Safety of the Public and Physical Safety. At present the US NRC has developed a new version of the SDP, which presents changes in its structure and the opportunity of carrying out informed evaluations in risk, with more detail about the violations or defaults that happen in different areas. The CNSNS carries out the adaptation of this last version of the SDP in order to have an updated tool for the violations and defaults characterization to the regulatory framework happened in the nuclear power plant of Laguna Verde. In this article is mentioned the legal framework that confers the CNSNS the attributions to impose urgency measures and administrative sanctions to its licensees, also is established the definition of the different colors that the SDP contemplates in function of the increased risk (ΔCdf), a description of the SDP objectives and the elements that conform it is presented, in the same way some examples to illustrate its application are raised. Finally, the steps to continue for their implementation are mentioned. (Author)

  11. Study on generation and granulometry of a standard aerosol of CINa for use in determinations of filtration efficiency of absolute filters; Estudio sobre la generacion y granulometria de un aerosol patron de CINa para la determinacion de eficacias filtrantes de filtros absolutos

    Energy Technology Data Exchange (ETDEWEB)

    Milla, E.

    1978-07-01

    This work has as objective the study of the conditions of generation and granulometry of an aerosol generated by atomizing with compressed a i r a solution of CINa in water in order to obtain particles, CINa cubes. The droplets of the spray formed are dried in a stream of air, acting as a carrier, inside the pipe of a bank of test filters. The granulometric analysis has been carried out by sampling in the gaseous phase. A dispersion photometer was used that yields the size spectrum of particles. The variables concerned in generation, whose influence on aerosol granulometry were analyzed are: characteristic diameter of atomizer unit, pressure of compressed air of generation, concentration of saline solution, temperature of air carrier, length of bank pipe, sampling position across a section, length of sampling duct and ratio between speeds in pipe and duct. (Author) 50 refs.

  12. CFD simulation in emptying tanks for calculating submergence in the case of storage tanks, the CFD simulation is based on the modeling of the suction nozzle which affects the study and final part of the storage tank; Aplicacion de simulacion CFD en el analisis del vaciado de tanques de almacenamiento para determinacion del nivel de sumergencia

    Energy Technology Data Exchange (ETDEWEB)

    Arranz Iglesias, J.; Gavilan Moreno, C.; Sarti Fernandez, F.

    2014-07-01

    The study consists in simulating the emptying of the tank when the water level is near the level of the suction nozzle. The objective pursued is to detect the harmful phenomena that may occur in aspiration, ranging from the appearance of vortices and bubble formation to excessive fluid accelerations. (Author)

  13. Determination of the neutron fluence in the welding of the 'Core shroud' of the BWR reactor core; Determinacion de la fluencia neutronica en las soldaduras del 'core shroud' del nucleo de un reactor BWR

    Energy Technology Data Exchange (ETDEWEB)

    Lucatero, M.A.; Xolocostli M, J.V.; Gomez T, A.M.; Palacios H, J.C. [ININ, 52750 Ocoyoacac, Estado de mexico (Mexico)]. e-mail: mal@nuclear.inin.mx

    2006-07-01

    With the purpose of defining the inspection frequency, in function of the embrittlement of the materials that compose the welding of the 'Core Shroud' or encircling of the core of a BWR type reactor, is necessary to know the neutron fluence received for this welding. In the work the calculated values of neutron fluence accumulated maxim (E > 1 MeV) during the first 8 operation cycles of the reactor are presented. The calculations were carried out according to the NRC Regulatory Guide 1.190, making use of the DORT code, which solves the transport equation in discreet ordinate in two dimensions (xy, r{theta}, and rz). The results in 3D were obtained applying the Synthesis method according to the guide before mentioned. Results are presented for the horizontal welding H3, H4, and H5, showing the corresponding curves to the fluence accumulated to the cycle 8 and a projection for the cycle 14 is presented. (Author)

  14. Radiotherapy with linear accelerator in a patient with permanent pacemaker, methodology and results of dose determination in a case in vivo; Radioterapia con Linac en un paciente con marcapasos permanente, metodologia y resultados de determinacion de dosis en un caso in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Diaz A, P.; Dominguez O, X.; Toledo B, V.; Nungaray, H.; Zazueta L, F., E-mail: pdiaz@hospitalsanjavier.co [Hospital San Javier, Pablo Casals No. 640, Col. Prados Providencia, 44670 Guadalajara, Jalisco (Mexico)

    2010-09-15

    This work presents the methodology used by the radiotherapy department of the Hospital San Javier in the patients handling with pacemaker. By means of dosimetry to the implant area of the pacemaker together with electrocardiography measurements during the radiotherapy sessions, the pacemaker performance is evaluated with the objective of detecting any anomaly to the same caused by electromagnetic interference and/or accumulated dose. It is necessary to follow specific protocols in these patients type that guarantee their security during the exposition to ionizing radiation since a definitive consent that allows to calculate the failure probability of pacemaker in this therapeutic condition does not exist. (Author)

  15. Determination of uranium and {sup 2}10Po in the river Odiel to assess the radioactive impact of acid mine drainage; Determinacion de uranio y {sup 2}10Po en el rio Odiel para valorar el impacto radiactivo de los drenajes acidos mineros

    Energy Technology Data Exchange (ETDEWEB)

    Manjon, G.; Lehritani, M.; Mantero, J.; Diaz Frances, I.; Garcia-Tenorio, R.

    2013-07-01

    Since 1986 this research group has been monitoring of radioactive environmental impact in the estuary of the river Odiel, generated by the factories of production of phosphoric acid from Huelva, that emitting NORM waste. Once closed factories, is observed a second source of contamination: mining drains. To verify this source have been studied concentration levels of natural radionuclides in the waters and sediments of the river Odiel, in areas that are incorporated drains. (Author)

  16. Spectrographic determination of impurities in ammonium bifluoride. III. Study of the processes of vaporization, transport and excitation of the elements Al, B, Cu and Cr; Determinacion espectrografico de impurezas en bifluoruro amonico. III. Estudio de los procesos de volatilizacion, transporte y excitacion de los elementos Al, B, Cu, Cr

    Energy Technology Data Exchange (ETDEWEB)

    Alduan, F. A.; Roca, M.; Capdevila, C.

    1979-07-01

    The influences of the processes of vaporization, transport and excitation on the shape of the volatilization-excitation curves and on the values of the spectral-line intensities have been investigated in a method for the spectrographic determination of Al, B, Cu and Cr In ammonium bifluoride samples by direct current are excitation in Scribner type electrodes, with addition of different matrices (graphite, 63203, GeO{sub 2}, MgO and Zn0). The reaction products in the electrode cavity have been identified by X-ray powder diffraction analysis and the percentages of vaporized and diffused element evaluated through analysis by total-burning spectrographic methods. In addition, the values of both the number of particles entering the discharge column and the transport efficiencies have been calculated. Thus, the origin of most observed differences has been explained. (Author) 11 refs.

  17. Application of the Temez model to determine surface and groundwater influx into the Cornisa-Vega-de-Granada water system with a view to integrating it into a conjunctive use code; Aplicacion del modelo de Temez a la determinacion de la aportacion superficial y subterranea del sistema hidrologico Cornisa-Vega de Granada para su implementacion en un modelo de uso conjunto

    Energy Technology Data Exchange (ETDEWEB)

    Murillo, J. M.; Navarro, J. A.

    2011-07-01

    We describe an application of the Temez model to calculate total water influx in a natural regime and its division into its surface and groundwater components. We also suggest a suitable way of integrating the data series obtained into the SIMGES conjunctive use code. The literature offers a considerable number of precipitation-runoff models for calculating the total influx into a basin. Within this context the Temez model is a relatively simple code which in certain cases has decided advantages over more complex ones, as we point out in this paper. For a better understanding of this model, we include an annex showing its mathematical basis. We used the Temez model to calculate the surface and groundwater influx into the Cornisa-Vega de Granada water system, which comprises 25 river sub-basins, 5 reservoirs and 23 aquifers, meaning that the interrelation between surface water and groundwater is quite complex and difficult to assess. In addition to this, some points of the series are quite difficult to calibrate because the natural regime of the water system is being considerably altered by human activity. We analyse the four parameters used in the Temez model together with the factors affecting both its calibration and the reliability and uncertainties of the results deriving from its application. (Author)

  18. Analytical Procedure Development to Determine Polycyclic Aromatic Compounds in the PM{sub 2}.5-PM{sub 1}0 Fraction of Atmospheric Aerosols; Desarrollo de una Metodologia Analitica para la Determinacion de Compuestos Aromaticos Policiclicos en las Fracciones PM{sub 2}.5-PM{sub 1}0 del Aerosol Atmosferico

    Energy Technology Data Exchange (ETDEWEB)

    Barrado, A. I.; Garcia, S.; Perez, R. M.

    2013-06-01

    This paper presents an optimized and validated analytical methodology for the determination of various polycyclic aromatic compounds in ambient air using liquid chromatography with fluorescence detection. This analysis method was applied to samples obtained during more than one year in an area of Madrid. Selected compounds have included thirteen polycyclic hydrocarbons considered priorities by the EPA, and hydroxylated derivatives, which have been less investigated in air samples by liquid chromatography with fluorescence detection. We have characterized and compared the concentration ranges of compounds identified and studied seasonal and monthly variations. In addition, the techniques have been applied to study multivariate correlations, factor analysis and cluster analysis to extract as much information as possible for interpretation and more complete and accurate characterization of the results and their relationship with meteorological parameters and physicochemical. (Author) 50 refs.

  19. Optimized Analytical Method to Determine Gallic and Picric Acids in Pyrotechnic Samples by Using HPLC/UV (Reverse Phase); Optimizacion del Metodo Analitico mediante HPLC/UV Operando en Fase Inversa para la Determinacion de Acido Galico y Acido Picrico en Muestras de Origen Pirotecnico

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Alonso, S.; Perez Pastor, R. M.

    2013-10-01

    A study on the optimization and development of a chromatographic method for the determination of gallic and picric acids in pyrotechnic samples is presented. In order to achieve this, both analytical conditions by HPLC with diode detection and extraction step of a selected sample were studied. (Author)

  20. Calculus of radiolytic products generation in water due to alpha radiation. Determination of the spent nuclear fuels matrix alteration rate Determination of velocity of spent fuel matrix; Calculo de la generacion de productos radioliticos en agua por radiacion {alpha}. Determinacion de la velocidad de alteracion de la matriz del combustible nuclear gastado

    Energy Technology Data Exchange (ETDEWEB)

    Quinones, J.; Serrano, J.; Diaz Arocas, P.; Rodriguez Almazan, J. L. [Ciemat. Madrid (Spain); Bruno, J.; Cera, E.; Merino, J.; Esteban, J. A.; Martinez-Esparza, A. [Enresa. Madrid (Spain)

    2000-07-01

    The generation of radiolytic products as a result of alpha radiation in the surface of the spent fuel is a key process in order to understand how the it becomes degraded in repository conditions. The present work has established a radiolytic model based on a set of reactions involving fuel oxidation-dissolution and radiolytic products recombination. It also includes the decrease of the dose rates as the main alpha emitters decay away. Four cases, with varying parameters of the system, have been assessed. The results show a decrease in both the concentration of the radiolytic products in the gap water and the degradation of the fuel matrix. It has been estimated that in the period of the evaluation (10''6 years) up to 52% of the pellet is altered in the conservative cases, whereas only 11% is altered in the realistic cases. No significant differences were observed when the carbonates reactions were included in the system. (Author)

  1. Radiological protection on interstitial brachytherapy and dose determination and exposure rate of an Ir-192 source through the MCNP-4B; Proteccion radiologica en braquiterapia intersticial y determinacion de la dosis y tasa de exposicion de una fuente de Ir-192 mediante el MCNP-4B

    Energy Technology Data Exchange (ETDEWEB)

    Morales L, M.E. [INEN, Av. Angamos Este 2520- Surquillo, Lima (Peru)

    2006-07-01

    The present work was carried out in the Neurological Sciences Institute having as objective to determine the dose and the rate of exhibition of the sources of Iridium 192, Iodine 125 and Palladium 103; which are used to carry out implant in the Interstitial Brachytherapy according to the TG43. For it we carry out a theoretical calculation, its are defined in the enter file: the geometry, materials of the problem and the radiation source, etc; in the MCNP-4B Monte Carlo code, considering a punctual source and for the dose determination we simulate thermoluminescent dosemeters (TLD): at 5 cm, 50 cm, 100 cm and 200 cm of the source. Our purpose is to analyze the radioprotection measures that should take into account in this Institute in which are carried out brain biopsies using a Micro mar stereotactic mark, and in a near future with the collaboration of a doctor and a cuban physique seeks to be carried out the Interstitial Brachytherapy technique with sources of Ir-192 for patient with tumors like glioblastoma, astrocytoma, etc. (Author)

  2. Optimization of the Analytical Method Using HPLC with Fluorescence Detection to Determine Selected Polycyclic Aromatic Compounds in Clean Water Samples; Optimizacion del Metodo Analitico mediante HPLC con Detector de Fluorescencia para la Determinacion de Ciertos Compuestos Aromaticos Policiclicos en Muestras de Aguas Limpias

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Alonso, S.; Perez Pastor, R. M.

    2013-10-01

    A study on the comparison and evaluation of 3 miniaturized extraction methods for the determination of selected PACs in clear waters is presented. Three types of liquid-liquid extraction were used for chromatographic analysis by HPLC with fluorescence detection. The main objective was the optimization and development of simple, rapid and low cost methods, minimizing the use of extracting solvent volume. The work also includes a study on the scope of the methods developed at low and high levels of concentration and intermediate precision. (Author)

  3. Quality in the organizations (enterprises and institutions of production and of services). Validation of the determination by atomic absorption of sodium and potassium in acid rain; Calidad de las organizaciones (empresas e instituciones de produccion y de servicios). Validacion de la determinacion por absorcion atomica de sodio y potasio en lluvia acida

    Energy Technology Data Exchange (ETDEWEB)

    Arreola T, D.L

    2005-07-01

    The present work is focused to the environmental area and in specific to the validation of an analytical method by means of one of the techniques more used for the determination of metals, the atomic absorption spectrophotometry. Applied to the study of the acid rain and its diverse forms in the nature. As well as their consequences and the role that the man carries out in the contribution toward this phenomenon. To approach the following text it will be mention shortly how is distributed, beginning with the introduction that is about the importance of the role of the acid rain, its effects and repercussions in the environment. In the first chapter the points that we should be evaluated to carry out a validation are analyzed. Being the main ones, the precision, accuracy, lineal interval, among others. Continuing in the second chapter with the foundation study, equipment and interferences of the atomic absorption spectrophotometry technique. The last chapter contains the experimental part, continuing for each evaluated point, from the experimental development, results and its analysis. (Author)

  4. Determination of the ratio of the spectral fluence of electrons in water, using a Newton Cotes closed quadrature method: rule composed of trapezium with non equi-spaced nodes; Determinacion de la razon de fluencias espectrales de electrones en agua, usando un metodo de cuadratura cerrada de Newton Cotes: regla compuesta del trapecio con nodos no equi-espaciados

    Energy Technology Data Exchange (ETDEWEB)

    Moranchel y Rodriguez, M. [IPN, ESFM, Departamento de Ingenieria Nuclear, 07738 Mexico D.F. (Mexico)]. e-mail: mmoranchel@ipn.mx

    2008-07-01

    The central problem of the dosimetry of the ionizing radiations is the determination of the dissipated energy by unit of mass of irradiated material. This energy usually is inferred of ionization measures in a small cavity of air housed inside the material medium. The Bragg-Gray cavity theory was the first one in estimating the dissipated energy through the ionizations that the primary electrons cause in the cavity. The primary electrons are generated by photoelectric effect, pair production and by Compton dispersion of the photon beams that initially impact on the material. However, in a more realist approach the existence of secondary electrons due to the electron-electron interaction it will be considered. The Spencer-Attix cavity theory considers to the secondary electrons as responsible part for the energy deposited in the means, for that a total spectral fluence of electrons (primary and secondary) it appears in this theory. Few electrons spectra have been published, mainly, those that include the contribution of secondary electrons ({delta} rays). Leaving of the ideas of Spencer-Attix, in this work an approach method to determine the rate of electron spectral fluences (total regarding primary) for a wide variety of material Z, and energy sources T{sub 0} is presented. The method for materials used by Spencer-Attix is applied, it is proven its reliability and it is applied to the water like absorber medium by its importance in the clinical dosimetry. (Author)

  5. Determination of the mechanical properties and fracture mechanisms of YSZ and GDC for electrolyte-supported SOFCs by instrumented indentation test; Determinacion de las propiedades mecanicas y mecanismos de fractura de electrolitos soportados de YSZ y GDC mediante ensayos de indentacion instrumentada

    Energy Technology Data Exchange (ETDEWEB)

    Roa, J. J.; Morales, M.; Capdevila, X. G.; Segarra, M.

    2010-07-01

    The main purpose of this work is to evaluate the different mechanical properties and the different fracture mechanisms activated during the instrumented indentation process of the electrolytes based on Yttria stabilized zirconia (YSZ) and gadolinia doped ceria (GDC), for solid oxide fuel cells (SOFCs). Both materials, with a thickness of 200 {mu}m, were shaped by uniaxial pressing at 500 MPa, and sintered at 1400 degree centigrade. Mechanical properties such as hardness (H) and Young's modulus (E) have been studied at different penetration depths using the Oliver and Pharr equations. The different fracture mechanisms activated during the instrumented indentation process have been studied at constant penetration depth of 500 nm, performed with a diamond Berkovich tip indenter. The residual indentation imprints have been observed with atomic force microscopy (AFM). The hardness and Young's modulus for YSZ electrolytes are higher than for GDC materials, due to the different fracture mechanism activated during the indentation process. As a result, the electrolytes of YSZ presented trans- and intergranular fracture mechanisms, depending on the place of the residual indentation imprint (in the grain boundary or in the middle of the grain, respectively). However, the GDC electrolyte revealed radical cracks at the corners of the residual nano indentation imprints, thus producing a phenomenon known as chipping. (Author)

  6. Determination of the exposure speed of radiation emitted by the linear accelerator, using the code MCNP5 to evaluate the radiotherapy room shields of ABC Hospital; Determinacion de la rapidez de exposicion de la radiacion emitida por el acelerador lineal, utilizando el codigo MCNP5, para evaluar los blindajes de la sala de radioterapia del Hospital ABC

    Energy Technology Data Exchange (ETDEWEB)

    Corral B, J. R.

    2015-07-01

    Humans should avoid exposure to radiation, because the consequences are harmful to health. Although there are different emission sources of radiation, generated by medical devices they are usually of great interest, since people who attend hospitals are exposed in one way or another to ionizing radiation. Therefore, is important to conduct studies on radioactive levels that are generated in hospitals, as a result of the use of medical equipment. To determine levels of exposure speed of a radioactive facility there are different methods, including the radiation detector and computational method. This thesis uses the computational method. With the program MCNP5 was determined the speed of the radiation exposure in the radiotherapy room of Cancer Center of ABC Hospital in Mexico City. In the application of computational method, first the thicknesses of the shields were calculated, using variables as: 1) distance from the shield to the source; 2) desired weekly equivalent dose; 3) weekly total dose equivalent emitted by the equipment; 4) occupation and use factors. Once obtained thicknesses, we proceeded to model the bunker using the mentioned program. The program uses the Monte Carlo code to probabilistic ally determine the phenomena of interaction of radiation with the shield, which will be held during the X-ray emission from the linear accelerator. The results of computational analysis were compared with those obtained experimentally with the detection method, for which was required the use of a Geiger-Muller counter and the linear accelerator was programmed with an energy of 19 MV with 500 units monitor positioning the detector in the corresponding boundary. (Author)

  7. Determination of the dosimetric properties of ZrO{sub 2}: Cu and it use in the ultraviolet radiation dosimetry; Determinacion de las propiedades dosimetricas de ZrO{sub 2}: Cu y su empleo en la dosimetria de la radiacion ultravioleta

    Energy Technology Data Exchange (ETDEWEB)

    Molina P, D. [Centro de Proteccion e Higiene de las Radiaciones, Apdo. Postal 6195, La Habana (Cuba); Olvera T, L.; Azorin N, J.; Barrera S, M.; Soto E, A.M. [UAM-I, Av. San Rafael Atlixco 186, 09340 Mexico D.F. (Mexico); Rivera M, T. [Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada, Unidad Legaria del IPN, Av. Legaria 694, 11500 Mexico D.F. (Mexico)]. e-mail: daniel@cphr.edu.cu

    2006-07-01

    In this work the experimental results of studying the thermoluminescent characteristics (TL) of the zirconium oxide doped with copper (ZrO{sub 2}: Cu) exposed to ultraviolet light of wavelength in the interval of 200-400 nm are presented. The material in powder form was prepared using the sol-gel method. The dosimetric characteristics studied includes the emission curve TL (curved TL), the thermoluminescent response in function of the wavelength, the minimum dose detectable and the lineality of the response. The TL response of the ZrO{sub 2}: Cu in function of the wavelength presents two maxima, in 260 and 290 nm, respectively. The TL curve of the ZrO{sub 2}: Cu showed two peaks, in 120 and 170 C, respectively, being its similar form for all the studied wavelengths. The response in function of the spectral irradiance results to be lineal in the interval from 160 to 2300 mJ/cm{sup 2}. The obtained results when studying the TL properties of ZrO{sub 2}: Cu exposed to the ultraviolet radiation show that it gathers dosimetric characteristics prominent to be used as an ultraviolet radiation dosemeter. (Author)

  8. Quantitative elemental determination of the particulate matter in the atmosphere of Pachuca city and the Real del Monte village, Hidalgo by means of PIXE technique; Determinacion elemental cuantitativa de la materia particulada en la atmosfera de la ciudad de Pachuca y el poblado de Real del Monte, Hidalgo, mediante la tecnica PIXE

    Energy Technology Data Exchange (ETDEWEB)

    Guasso G, C.L. [ITT, 50000 Toluca (Mexico)

    2001-07-01

    All the pollutants that are generated so much of anthropogenic activities as natural cause effects to the health, and of course its increase the atmospheric pollution. Today in day for the great advance of the technology other pollutants are even generated but noxious to the human being's health, such it is the case of the particles, which are also called particulate matter airborne (MPA). This has motivated, to establish control measures leaning in collection strategies and certified analysis techniques, accurate and reliable. In the National Institute of Nuclear Research (ININ) they have been carried out studies on particulate matter airborne. In 1991 it was installed, calibrated and validated the nuclear technique of atomic origin based on proton beams known as PIXE. The characterization of the (MPA) it is carried out applying this technique and the collection by means of Dichotomous collectors (SFU). The thesis work that is presented next, includes the topic of the atmospheric pollution by particulate matter airborne (MPA) in a mining region, inside the Hidalgo State. The study was carried out during the 1998 winter season, only embracing the whole month of March in alternate days giving a total of 112 samples. Two sites that are highly active in the mining were studied, these are: the Real del Monte town and the Hidalgo state capital: Pachuca. Four samples per day were collected beginning to the 7:00 am--7:00 pm (daytime period) and concluding to the 7:00 pm -7:00 am (nocturne period). The characterization of its elementary content is carried out using the X-ray emission induced by particles technique (PIXE) that is a nuclear technique able to analyze 23 chemical elements beginning from the Al to the Pb, it requires of a very small sample quantity, it is very sensitive and it is not destructive. This characterization one carries out so much for fraction PM{sub 2.5} (fine) like as PM{sub 10} (thick) in both sites, also it was analyzed the temporary variation that the chemical elements detected in the samples present in the atmosphere and it was determined for each particle fraction the enrichment factor, all them during the daytime and nocturne periods. The document is removed in 5 topics, the topic I refers to the foundations, in them that is the MPA and the introduction to the PIXE technique is presented; the topic ll is the methodology used for the samples characterization, using the introduction of the technique and instrumentation of the same one, as well as the mathematical process for the determination of the concentrations of the detected elements, also approaches the analysis programs used for the concentration determination; the topic III, it presents the results discussion, the topic IV the conclusions and lastly the topic V it includes the recommendations with base to the obtained results, its are also presented the carried out consultations and the annexes for both sites, these last ones include charts of results, graphic of temporary variation, location map of the sites and enrichment factor graphics. (Author)

  9. Geochronological and thermochronological constraints on porphyry copper mineralization in the Domeyko alteration zone, northern Chile Determinaciones geocronológicas y termocronológicas para la mineralización de cobre porfídico en la zona de alteración de Domeyko, norte de Chile

    Directory of Open Access Journals (Sweden)

    Víctor Maksaev

    2010-01-01

    Full Text Available At Domeyko, 40 km south of Vallenar in northern Chile (28°57'S-70°53'W, the Dos Amigos and Tricolor porphyry copper centers are located within a north-south-elongated hydrothermal alteration zone 6x1.5 km of surface dimensions. The centers are related to tonalite to granodiorite porphyry stocks displaying potassic alteration, which are surrounded by Lower Cretaceous andesitic volcanic rocks with sericitic, kaolinite-illite and propylitic alteration zones. The western boundary of the alteration zone is marked by the post-mineralization Cachiyuyo Batholith of granodioritic to dioritic composition. U-Pb zircon ages for the Dos Amigos porphyry are of 106.Ü3.5 and 104.0±3.5 Ma; and 108.5±3.4 for the nearby Tricolor porphyry. The Cachiyuyo Batholith yielded U-Pb zircon ages of 99.6±1.8 and 99.1±1.9 Ma; and 40Ar/39Ar ages for biotite of 96.9±3.9 and 94.8±0.9 Ma. These dates indicate that batholith emplacement postdated the Dos Amigos and Tricolor porphyries, in agreement with geological relationships. Although copper mineralization is spatially and genetically related to the Lower Cretaceous (Albian porphyry stocks, most of the dated hydrothermal micas from the Dos Amigos and Tricolor porphyries yielded 40Ar/39Ar ages between 97.1±2.5 and 96.0±1.4 Ma, which overlap within error with the cooling ages obtained for the neighboring batholith. 40Ar/39Ar dating of micas revealed significant disturbance of their K-Ar isotopic systematics that complicates accurate determination of the timing of hydrothermal activity at Domeyko. Nevertheless, the 40Ar/39Ar data establish a minimum Late Cretaceous age for this activity. A fission track age of 59.8±9.8 Ma of apatite from the Dos Amigos porphyry indicates cooling through the temperature range of the apatite partial annealing zone (~125-60°C during the Paleocene; and an (U-Th/He age of 44.7±3.7 Ma of apatite from the same porphyry sample shows cooling through the temperature range of the apatite He partial retention zone (~85-40°C during the Eocene. These ages correspond to the exhumation of the porphyry, and the latter provides a maximum age for the supergene enrichment processes that formed the chalcocite blanket currently mined at Dos Amigos.En Domeyko, a 40 km al sur de la ciudad de Vallenar, en el norte de Chile (28°57'S-70°53'O, se ubican los pórfidos cupríferos Dos Amigos y Tricolor dentro de una zona de alteración hidrotermal elongada en sentido norte-sur de 6x1,5 km. Estos están relacionados con stocks porfídicos tonalíticos a granodioríticos con alteración potásica, rodeados por zonas de alteraciones sericítica, caolinita-illita y propilítica, las cuales afectaron principalmente rocas volcánicas del Cretácico Inferior. El límite oeste de la zona de alteración lo constituye el Batolito Cachiyuyo postmineral de composición granodiorítica a diorítica. Edades U-Pb en circón para el pórfido Dos Amigos son de 106,1±3,5 Ma y 104,0±3,5 Ma y de 108,5±3,4 Ma para el pórfido Tricolor. El Batolito Cachiyuyo adyacente dio edades U-Pb en circón de 99,6±1,9 y 99,1±1,9 Ma y edades 40Ar/39Ar en biotita de 96,9±3,9 y 94,8±0,9 Ma. De acuerdo a estas edades el emplazamiento del batolito fue posterior a los pórfidos Dos Amigos y Tricolor, consistente con las relaciones geológicas. Aunque la mineralización de cobre está relacionada espacialmente y genéticamente con los stocks porfídicos del Cretácico Inferior (Albiano, la mayoría de las micas datadas de los pórfidos Dos Amigos y Tricolor dieron edades 40Ar/39Ar entre 97,1±2,5 y 96,0±1,4 Ma, las cuales son coincidentes con las edades de enfriamiento obtenidas para el batolito. La datación 40Ar/39Ar por pasos de micas reveló una importante perturbación del sistema isotópico K-Ar de las mismas, lo que complica una determinación exacta de la edad de la actividad hidrotermal en Domeyko, pero los datos 40Ar/39Ar establecen con certeza una edad mínima Cretácico Tardío para ella. Una edad de trazas de fisión en apatita de 59,8±9,8 Ma para el pórfido Dos Amigos indica enfria

  10. Determination {sup 230}Th by ICP-MS for the control of activities of restoration of an area of land contaminated with uranium mining sterile; Determinacion de {sup 230}Th mediante ICP-MS durante el control de las actividades de restauracion de un area de terreno contaminada con esteriles de mineria de uranio

    Energy Technology Data Exchange (ETDEWEB)

    Yague, L.; Conde, E.; Navarro, N.; Fernandez, M.; Ortiz, M. I.; Noguerales, C.; Gasco, C.

    2013-07-01

    In 2012, within the activities for the Project PIMIC (CIEMAT) took out the first stage of restoration of a contaminated area. This is an area which had a residual contamination due to burial tailings uranium mining. The activities have been: elimination of the arboreal mass, excavation of the ground and earthmoving. The methodology applied is described in this work and is based on the combination of gamma spectrometry technique and development of a method of analysis {sup 230}Th by ICP-MS. (Author)

  11. Validation of the methodology for determining As, Sb, Hg, and Se in the water supply in Tudela, Navarra, spain, by atomic absorption; Validacion de la metodologia para la determinacion de As, Sb, Hg, y Se en aguas de abastecimiento a Tudela (Navarra) por absorcion atomica

    Energy Technology Data Exchange (ETDEWEB)

    Gale, M. A.; Cebrian, N.; Ormad, P.; Ovelleiro, J. L.

    2002-07-01

    In compliance with the current regulations on water quality, an analytical methodology has been put in place in the laboratory of the waste water treatment plant in Tudela, Navarre (Spain) to monitor As, Sb, Hg, and Se in the water going into the public water supply. The technique used to monitor these elements is atomic absorption spectrometry, As, Sb, Se are determined by the generation of hydrides and Hg by the generation of cold vapour. In addition, in order to ensure the authenticity of the results, the methodology employed has been validated by a study of the following technical characteristics: linearity, work interval, sensitivity, precision and accuracy. Extremely satisfactory results were obtained in all cases. A linear range between 0 and 1000 mg/l for all four elements and extremely low detection and quantification limits (less than 1 mg/l) were found. In the study of the method's accuracy, the C. V. s were below the legally established minima and the method was found to be very accurate. (Author) 18 refs.

  12. Construction of an external electrode for determination of electrochemical corrosion potential in normal operational conditions of an BWR type reactor for hot cells; Construccion de un electrodo externo para determinacion del potencial de corrosion electroquimico en condiciones normales de operacion de un reactor tipo BWR para celdas calientes

    Energy Technology Data Exchange (ETDEWEB)

    Aguilar T, J.A.; Rivera M, H.; Hernandez C, R. [Departamento de Sintesis y Caracterizacion de Materiales, Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    2001-07-01

    The behavior of the corrosion processes at high temperature requires of external devices that being capable to resist a temperature of 288 Centigrade and a pressure of 80 Kg/cm{sup 2}, to give stable and reproducible results of some variable and resisting physically and chemically the radiation. The external electrode of Ag/AgCl fulfils all the requirements in the determination of the electrochemical corrosion potential under normal operational conditions of a BWR type reactor in hot cells. (Author)

  13. Study on the preparation and stability of uranium carbide samples for the determination of oxygen, hydrogen and nitrogen by fusion under high vacuum; Estudio sobre la preparacion y estabilidad de las muestras de carburo de uranio para la determinacion de oxigeno, hidrogeno y nitrogeno por fusion en alto vacio

    Energy Technology Data Exchange (ETDEWEB)

    Perez Garcia, M.

    1966-07-01

    In view of the high reactivity of uranium carbide, the method employed for the preparation of the sample for the analysis of its gas content: oxygen, hydrogen and nitrogen, has a decisive influence on the analytical results. The variation in the O{sub 2}, H{sub 2} and N{sub 2} content of the uranium carbide has been studied in this paper with the methods utilized for the sample preparation (grinding and cutting). (Author) 9 refs.

  14. Estimation of the water volume to be managed in the infrastructure of phase II of the artificial recharge plant in the El Carracillo region, Segovia (western area); Determinacion de los volumenes de agua a gestionar en las infraestructuras de la fase II del proyecto de recarga artificial del acuifero cuaternario de la comarca de El Carracillo, Segovia (sector occidental)

    Energy Technology Data Exchange (ETDEWEB)

    Macias Antequera, C.; Martinez Gamo, R.; Martinez Rubio, J.

    2014-10-01

    The first hydrogeological investigation for the definition of the Carracillo aquifer (Segovia) was carried out in order to plan the best possible artificial recharge works provided for within the framework of the Royal Decree- Law 9/1998 El Carracillo Aquifer Recharge. Intake and Pipeline Work, Infiltration and Irrigation Adequacy (Segovia) These studies revealed the existence of two regions hydro geologically favourable for water storage from flows derived from the river Cega: the first known as the paleo-landform site located within the irrigation area, and the second area called the storage area located in the eastern sector of the district. In order to exactly estimate the minimum and maximum volume of water that has to be managed in the paleo-landform site over a period of five years, the Tragsa Group has carried out, at the request of the Ministry of Agriculture Fisheries and Food, some of the hydrogeological work, which included the exhaustive follow up of the piezometric behaviour of the aquifer and the detailed analysis of each of the external actions that have a direct influence upon it, such as the useful rain, the artificial recharge, the extraction by pumping, and the overland flow, amongst others. (Author)

  15. Método gravimétrico para determinar in situ la humedad volumétrica del suelo

    Directory of Open Access Journals (Sweden)

    Ricardo Radulovich

    2009-01-01

    m de profundidad, para un volumen de 0,001 m3. Se determinó los valores de Avol para 3 suelos de Costa Rica. Estos valores no fueron significativamente diferentes de, y sí fueron significativamente correlacionados a, determinaciones termogravimétricas estándar de contenido de humedad convertidas a Avol.

  16. Particle Flux in the Western Black Sea in the Present and over the Last 5,000 Years: Temporal Variability, Sources, Transport Mechanisms.

    Science.gov (United States)

    1987-09-01

    Determinacion de Al, Fe, Mg, Ti y Mn en sedimentos marinos. Estudio comparativo de las tecnicas Si de plasma de induccion (ICP) absorcion atomica...Fiur 10:r Cros-coreltio between’ th rai abn/croae pu bignc sliae rto fte20 n ,00m ta o Phsfti.93.Oe lgofstcorsodst.n.smln inevl hc s 13 dy. Te

  17. nigeria

    African Journals Online (AJOL)

    Rose

    AMA (Agencia de Medio Ambiente de Andalucia, Spain),. 1992. Determinacion del contenido de pesticides en agues y de metales en organismo vivos (. Determining the pesticide content in waters and the metal content in living organisms). Seville,. Spain Ed. AMA, 55-67. Biney, C.A., 1991. Trace metal levels in fish from.

  18. Determination of differences in the left ventricular ejection fraction (LVEF) by radionuclides and echocardiography pre and post treatment with anthracycline in pediatric patients with oncology diagnostic of the La Raza Medical Center; Determinacion de diferencias en la fraccion de eyeccion del ventriculo izquierdo (FEVI) por radionuclidos y ecocardiografia pre y post tratamiento con antraciclinas en pacientes pediatricos con diagnostico oncologico del Centro Medico La Raza

    Energy Technology Data Exchange (ETDEWEB)

    Veras R, H

    2003-07-01

    The objective of this work was to correlate the left ventricular ejection fraction determine by radionuclide angiocardiography and echocardiography in pediatric patients under anthracycline treatment. Material and methods: 41 patients were studied with range age from 3 to 14 years, with oncology diagnostic that were treated with anthracycline. Radionuclide angiocardiography and echocardiography were performed before an after anthracycline administration to determine the changes in the Ieft ventricular ejection fraction. Results: Anthracycline treatment caused no changes in the electrocardiography, echocardiogram and radionuclide angiocardiography. Conclusions: In our study anthracycline treatment caused no changes in the electrocardiography, echocardiography and both radionuclide angiocardiography techniques, first-pass and equilibrium. A high correlation was obtaining when left ventricular ejection fraction is compared between radionuclide angiocardiography and echocardiogram. (Author)

  19. Determination of the correction factor for attenuation, dispersion and production of electrons (K{sub wall}) in the wall of graphite of a ionization chamber Pattern National Type CC01 in fields of gamma radiation of {sup 60}Co; Determinacion del factor de correccion por atenuacion, dispersion y produccion de electrones (K{sub wall}) en la pared de grafito de una Camara de Ionizacion Patron Nacional Tipo CC01 en campos de radiacion gamma de {sup 60} Co

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez R, J.T.; Morales P, J.; Cruz E, P. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    2001-12-15

    It was determined the Kwall correction factor for the wall of graphite of the chamber of the pattern national type CC01 series 133 for a radiation field Gamma of {sup 60}Co. With this end to measured the currents of ionization l(x) as function of the thickness of the wall of the chamber: X=4,8,12,16 and 20 mm.The mensurations for each thickness consisting of three groups, of sizes n = 30 or 60 data for each group; obtaining 8 complete groups of mensurations independent in eight different dates.The determinate the factor carried out using three regression models: lineal, logarithmic and quadratic, models that were tried to validate with the tests of : i) Shapiro-Wilk and {chi}{sup 2} for the normality of the entrance data ii) Tests of Bartlett for variances homogeneity among groups for each thickness iii) The tests of Duncan for the stockings among groups of each thickness, and iv) The tests of adjustment lack (LOF) for the models used. Nevertheless, alone the models of the group of corresponding mensurations at 01-03-2000 17-08-2001 they can be validated by LOF, but not for tests of normality and homogeneity of variances. Among other assignable causes of variation we have: i) The values captured by the system of mensuration of the variables of it influences: pressure, temperature and relative humidity don{sup t} belong together with the existent ones to the moment to capture the l(x). ii) The mensuration room presents flows of air, for what was suited o diminish their volume and to eliminate the flows of air. iii) A protocol settled down of taking of measures that it consisted in: - Pre-irradiation 5 minutes the chamber after the change of polarity and hood change, with a period of stabilization of 5 minutes after the pre-irradiation. - Pre-irradiation for 5 minutes before the taking of the readings, with the object of eliminating variation sources assigned to currents of escapes or due variations to transitory. iv) To realize corrections for relative humidity of agreement with the reference, [13). Nevertheless, our values of Kwall = 1.1035 {sub +} 0.08% and those reported by the manufacturer (Kwall=1.0136), both fixeds with a lineal model, defer a maximum of 0.1%. (Author)

  20. Determination of the constants of the solubility product of Ln(OH){sub 3} and the effect of the chloride ions on the lanthanum hydrolysis, praseodymium and lutetium in aqueous solutions of ion force 2 Molar; Determinacion de las constantes del producto de solubilidad de Ln(OH){sub 3} y el efecto de los iones cloruro sobre la hidrolisis de lantano, praseodimio y lutecio en soluciones acuosas de fuerza ionica 2 Molar

    Energy Technology Data Exchange (ETDEWEB)

    Lopez G, H.D

    2005-07-01

    The behavior of lanthanum (III), praseodymium (III), and lutetium (III) was studied in 2 M NaClO{sub 4} (aq) and 2 M NaCl (aq) at 303 K and free -CO{sub 2} conditions. Solubility diagrams (p Ln(aq)-pC{sub H}) were obtained by means of a radiochemical method. The pC{sub H} borderlines of saturation and unsaturation zones of the solutions and solubility product constants for Ln(OH){sub 3} were determined from these diagrams. The fitting of the solubility equation to the experimental values of p Ln(aq)-pC{sub H} diagrams allowed the calculation of the first hydrolysis and solubility product constants. Independently, the stability constants for the first species of hydrolysis were determined by means of pH titrations, the data were treated with the program SUPERQUAD and fitted to the mean ligand number equation. The stability constants for the species LnCl{sup 2+} were as well calculated in 2M ionic strength and 303 K from the hydrolysis constant values obtained in both perchlorate and chloride media. The values obtained for La, Pr and Lu were: logK{sub ps}: 21.11 {+-} 0.09, 19.81 {+-} 0.11 and 18.10 {+-} 0.13 in 2M NaClO{sub 4}; logK{sub ps}: 22.22 {+-} 0.09, 21.45 {+-} 0.14 and 18.52 {+-} 0.29 in 2M NaCl; log {beta}{sub 1}: - 8.64 {+-} 0.02, - 8.37 {+-} 0.01 and - 7.95 {+-} 0.11 in 2M NaClO{sub 4}; log {beta}{sub 1}{sup /} : - 9.02 {+-} 0.11, - 8.75 {+-} 0.01 and - 8.12 {+-} 0.03 in 2M NaCl and the values for log {beta}{sub 1,Cl} were - 0.0255, - 0.155 and - 0.758, respectively. (Author)

  1. LABORATORIO DE HORMONAS: ASPECTOS PRÁCTICOS

    Directory of Open Access Journals (Sweden)

    René E. Díaz T., DR.

    2015-11-01

    Full Text Available Las técnicas de laboratorio de análisis hormonales han experimentado grandes progresos en las últimas décadas, actualmente se pueden realizar determinaciones hormonales con gran precisión y automatización, sin embargo, existen muchos elementos que es necesario tener en consideración al momento de interpretar un examen hormonal. El elegir el examen adecuado para la condición que estamos estudiando, el conocer sus limitaciones y potenciales falsos positivos y negativos es parte del conocimiento que es fundamental tener como clínicos. En este artículo se pretende entregar una breve revisión de las principales determinaciones hormonales, orientado a aspectos que puedan ser de utilidad al médico no especialista en su práctica clínica.

  2. Análisis de contaminantes en aguas residuales industriales mediante espectrofotometría de absorción molecular y atómica

    OpenAIRE

    Torres Andrés, Adrián

    2017-01-01

    Las aguas residuales suponen un grave problema incrementado con el desarrollo industrial. Las plantas de tratamiento de aguas residuales son muy importantes para preservar el medioambiente y eliminar compuestos contaminantes. Es interesante desarrollar métodos analíticos sencillos y robustos para determinar contaminantes como metales, amonio o cianuro y conocer la calidad del agua. Este trabajo recoge determinaciones de este tipo de compuestos en aguas residuales industriales mediante espectr...

  3. REPENSANDO LA CRISIS COMO CONCRECIÓN CONCEPTUAL

    Directory of Open Access Journals (Sweden)

    Mario González Arencibia

    2006-07-01

    Full Text Available El ensayo pretende contribuir a la reflexión sobre la crisis como concreción conceptual desde el enfoque marxista. Desde el punto de vista metodológico, asume como aspecto central a la crisis como el resultado de múltiples manifestaciones, siendo un proceso de determinaciones, que contiene una relación de causa y efecto, que abarca esta como un todo único y de manera dialéctica.

  4. Mineralización de los fertilizantes orgánicos, sirle y turba.

    OpenAIRE

    Reverte Navarro, Pablo; Costa Yagüe, Francisco

    1980-01-01

    En el trabajo que se ha llevado a cabo nos ha interesado conocer algunos aspectos del comportamiento de dos tipos de fertilizantes orgánicos, sirle y turba, cuando sufren un período de descomposición en el suelo. Para intentar cumplir los fines propuestos en esta experiencia, se han realizado diversas determinaciones químicas y microbiológicas.

  5. Un estado del arte en pedagogía e infancia

    OpenAIRE

    Vargas Amézquita, Sonia Lucia

    2015-01-01

    El presente estado del arte tiene como eje central la pedagogía e infanciase realiza por parte del Grupo de Investigación en Pedagogía e Infanciay se rige por las determinaciones de la División de Investigaciones yPosgrados (DIP), de la Corporación Universitaria Adventista (UNAC).

  6. Evolucion demografica y demanda de viviendas en Galicia.

    OpenAIRE

    Lopez, Carmen

    1998-01-01

    El objetivo de este trabajo es analizar los efectos que sobre la demanda de viviendas tendra la evolucion de la poblacion gallega en el periodo 1991 - 2026, mediante estimaciones y previsiones sobre flujos de formacion y desaparicion de hogares. Para la determinacion de necesidades de viviendas principales asociadas a este proceso se plantean diferentes escenarios alternativos en funcion, entre otros factores, del grado de reutilizacion de las viviendas que quedan libres como consecuencia de ...

  7. Vitamina C, carotenoides, fenólicos totais e atividade antioxidante de goiaba, manga e mamão procedentes da Ceasa do Estado de Minas Gerais = Vitamin C, carotenoids, phenolic compounds and antioxidant activity of guava, mango and papaya from Ceasa of Minas Gerais State

    Directory of Open Access Journals (Sweden)

    Daniela da Silva Oliveira

    2011-01-01

    Full Text Available Este estudo teve como objetivo analisar o conteudo de compostos antioxidantes (acido ascorbico - AA, acido desidroascorbico - ADA, vitamina C total, licopeno, £]-caroteno, £]-criptoxantina e estimativa de compostos fenolicos e avaliar a atividade antioxidante, em goiaba, manga e mamao. A analise de carotenoides e vitamina C foi realizada por Cromatografia Liquida de Alta Eficiencia (CLAE. O teor de fenolicos totais foi determinado utilizando o reagente de Folin-Ciocalteu e leitura espectrofotometrica. A atividade antioxidante foi avaliada pelo Teste do 2,2-diphenil-2-picril-hidrazil (DPPH¡E e do Poder Redutor. A Anova (ƒÑ = 0,05 foi utilizada para a analise dos dados. Os teores dos constituintes antioxidantes diferiram entre as tres frutas, mas a goiaba foi a fruta que apresentou teores mais elevados de compostos fenolicos, vitamina C total, ADA e licopeno, alem dos maiores valores para atividade antioxidante. Foi constatada forte correlacao entre os testes que avaliaram a atividade antioxidante e o teor de fenolicos totais, demonstrando serem estes os principais compostos antioxidantes a contribuirem para a atividade antioxidante das frutas analisadas, em ambos os testes. E importante incentivar a utilizacao das frutas avaliadas neste estudo, tanto em nivel domestico quanto em estabelecimentos de alimentacao coletiva para aumentar o consumo de antioxidantes naturais pela populacao.This study aimed to analyze the content of antioxidant compounds (ascorbic acid - AA, dehydroascorbic acid - DHA, total vitamin C, lycopene, £]-carotene, £]-cryptoxanthin and phenolic compounds and to evaluate the antioxidant activity in guava, mango and papaya.The analysis of carotenoids and vitamin C was performed by high performance liquid chromatography (HPLC. The content of phenolic compounds was determined using the Folin-Ciocalteu reagent and spectrophotometric reading. Antioxidant activity was evaluated by testing the 2.2-diphenyl-2-picryl

  8. Measurement of dose equivalent with personal dosemeters and instrumentation of radiological protection in the new operative ICRU magnitudes, for external fields of beta radiation. Part III. Determination of the joint of factors of angular conversion for the secondary source pattern Nr. - 86 Of (1850) MBq; Medicion de dosis equivalente con dosimetros personales e instrumentacion de proteccion radiologica en las nuevas magnitudes operativas ICRU, para campos de radiacion Beta externos. Parte III. Determinacion del conjunto de factores de conversion angular para la fuente patron secundario Nr.- 86 de (1850) MBq

    Energy Technology Data Exchange (ETDEWEB)

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

    1994-02-15

    It determined the assembly of factors of angular conversion T(0;{alpha}), for the source secondary pattern of {sup 90}Sr/{sup 90}Y (1850 MBq) at a distance detecting source of 30 cm, in the following angles: 0, 15, 30, 45, 60 and 75{sup 0}. Obtaining the values of: 1.01, 1.05, 1.13, 1.19 and 0.95, respectively. Their Global uncertainty is smaller to 1.5% for all the cases and its percentage differences with regard to the values reported by the Draft of the norm ISO 6980(1992) they are smaller to 3.0% for all the cases.The technique employee was that of the extrapolation Chamber and the treatment of the uncertainties is made of agreement with the recommendations of the BIPM. (Author)

  9. Comparação entre a utilização de saliva e sangue para determinação do lactato mínimo em cicloergômetro e ergômetro de braço em mesa-tenistas Comparacion entre la utilizacion de saliva y sangre para la determinacion del lactato mínimo en cicloergómetro y ergómetro de brazo en tenistas de mesa Comparison between the use of saliva and blood for the minimum lactate determination in arm ergometer and cycle ergometer in table tennis players

    Directory of Open Access Journals (Sweden)

    Alessandro Moura Zagatto

    2004-12-01

    Full Text Available O objetivo do estudo foi verificar a possibilidade de determinar o teste de lactato mínimo (TLM com concentrações de sódio (Na+, potássio (K+ e lactato (LAC na saliva em ergômetro de braço e cicloergômetro. Foram participantes deste estudo oito mesa-tenistas de nível internacional. Como estímulo anaeróbio no TLM em ambos os ergômetros foram utilizados testes máximos de 30 segundos. No ergômetro de braço isocinético (Cybex Ube 2432 foi aplicada a força máxima com rotação fixa em 102rpm e no cicloergômetro, aplicada a carga de 7,5% do peso corporal (Kp. Após o estímulo anaeróbio no ergômetro de braço, foi iniciado um teste incremental com rotações na manivela constante a 60rpm, iniciado a 49 watts com aumento de 16 watts a cada estágio de três minutos de exercício. A intensidade correspondente ao TLM foi determinado com amostras de sangue e saliva (LACmin braço; Na+min braço-saliva e K+min braço-saliva, respectivamente. Para o cicloergômetro, a carga inicial foi de 85 watts e aumento de 17 watts com rotação do pedal constante a 70rpm. Cada estágio de exercício também teve a duração de três minutos. O LACmin foi determinado utilizando amostras de sangue e saliva (LACmin ciclo; Na+min ciclo-saliva, K+min ciclo-saliva e LACmin ciclo-saliva, respectivamente. Em ambos os ergômetros, as intensidades obtidas no TLM foram correspondentes à derivada zero do ajuste polinomial entre metabólito versus intensidade. Foram utilizados, como procedimentos estatísticos, o teste ANOVA One Way, teste t de Student pareado e teste de correlação de Pearson com níveis de significância de 5%. Os LACmin determinados com amostras de sangue e de saliva, tanto para o ergômetro de braço (LACmin braço 91,71 ± 12,43; Na+min braço-saliva 71,99 ± 23,42; K+min braço-saliva 79,67 ± 17,72, quanto para cicloergômetro (LACmin ciclo 157,68 ± 13,48; LACmin ciclo-saliva 135,49 ± 33,2; Na+min ciclo-saliva 121,81 ± 51,31; K+min ciclo-saliva 135,49 ± 33,21, não foram diferentes significativamente. Contudo, essas intensidades não apresentaram correlações significativas. Pode-se então concluir que a utilização de metabólitos na saliva para determinação do TLM não parece ser possível para esse protocolo quando os ergômetros utilizados são o ergômetro de braço isocinético e o cicloergômetro.El objetivo de estudio fué el de verificar la posibilidad de determinar el test de lactato mínimo (TLM con concentraciones de sodio (Na+, potasio (K+ y lactato (LAC en la saliva en ergómetro de brazo y cicloergómetro. Fueron participantes de este estudio ocho tenistas de mesa de nivel internacional. Como estímulo anaeróbico en el TLM en ambos ergômetros, fueron utilizados tests máximos de 30 segundos. En el ergómetro de brazo isocinético (CYBEX UBE 2432 fué aplicada la fuerza máxima con rotación fija en 102 rpm en el cicloergómetro aplicando una carga de 7,5% del peso corporal (Kp. Después del estímulo anaeróbico en el ergómetro de brazo, fué iniciado un test incremental con rotaciones en la manivela constante a 60 rpm, iniciando a 49 Watts con aumento de 16 Watts en cada etapa de 3 minutos del ejercicio. La intensidad correspondiente al TLM fué determinado con muestras de sangre y saliva (LACmin brazo; Na+min brazo-saliva e K+min braço-saliva, respectivamente. Para el cicloergometro, la carga inicial fue de 85 Watts y aumento de 17 Watts con rotación del pedal constante a 70 rpm. Cada etapa de ejercicio también tiene una duración de 3 minutos. El LACmin fué determinado utilizando las muestras de sangre y saliva (LACmin ciclo; Na+min ciclo-saliva, K+min ciclo-saliva e LACmin ciclo-saliva, respectivamente. En ambos ergómetros, las intensidades obtenidas en el TLM fueron correspondientes a la derivada cero del ajuste polinominal entre metabólito versus intensidad. Fueron utilizados como procedimientos estadísticos, el test ANOVA One Way, test "t" de Student apareado al test de correlación de Pearson con niveles de significancia de 5%. Los LACmin determinados con muestras de sangre y de saliva tanto para el ergômetro de brazo (LACmin brazo 91,71 ± 12,43; Na+min brazo-saliva 71,99 ± 23,42; K+min brazo-saliva 79,67 ± 17,72, como para el cicloergómetro (LACmin ciclo 157,68 ± 13,48; LACmin ciclo-saliva 135,49 ± 33,2; Na+min ciclo-saliva 121,81 ± 51,31; K+min ciclo-saliva 135,49 ± 33,21 no fueron diferentes significativamente. Con todo, estas intensidades no presentaron correlaciones significativas. Se puede entónces concluir que la utilización de los metabólitos en la saliva para la determinación de la del TLM no parece ser posible para este protocolo cuando los ergómetros utilizados son el ergómetro de brazo isocinético y el cicloergómetro.The aim of this study was to verify if it is possible to determine the lactate minimum test (LMT by saliva sodium (Na+, potassium (K+ and lactate (LAC concentrations in arm ergometer and cycle ergometers. Eight male international-level table tennis players participated in this study. To induce increases of lactate concentration in both ergometers, 30 seconds maximal tests were used with maximal force application in constant 102 rpm in isokinetic arm ergometer (Cybex UBE 2432, and loads of 7.5% of body weight (Kp in cycle ergometer (mechanical Monark. After the anaerobic stimulus in arm ergometer, the incremental test was applied at constant 60 rpm, started at 49 watts and increment loads of 16 watts each three minutes. The LMT intensity was determined with the analysis of the blood lactate (LACmin arm and the saliva concentrations of sodium (Na+min arm-saliva and potassium (K+min arm-saliva. For the cycle ergometer, the incremental test started with an intensity of 85 watts and increments of 17 watts at constant speed of 70 rpm. The stages were also of three minutes. The LACmin was determined using blood and saliva samples (LACmin cycle; Na+min cycle-saliva, K+min cycle-saliva and LACmin cycle-saliva, respectively. In both ergometers, the intensity obtained in lactate minimum test was correspondent to zero derived polynomial adjustments by metabolite concentrations versus exercise intensities. The statistical analysis included one way ANOVA test, paired t-test and Pearson's correlations. For all tests applications, the significance level was prefixed at 5%. The several LACmin determinations using blood and saliva samples did not show significant differences in arm and cycle ergometers (LACmin arm 91.71 ± 12.43; Na+min arm-saliva 71.99 ± 23.42; K+min arm-saliva 79.67 ± 17.72; LACmin cycle 157.68 ± 13.48; LACmin cycle-saliva 135.49 ± 33.2; Na+min cycle-saliva 121.81 ± 51.31; K+min cycle-saliva 135.49 ± 33.21 watts. However, these intensities presented no significant correlations. These results showed that determination of the LMT by saliva lactate, sodium and potassium concentrations seems not to be possible with the use of isokinetic arm ergometer and cycle ergometers.

  10. El mundo del libro: Camilo: presencia y destino Junio de 1967

    Directory of Open Access Journals (Sweden)

    Monseñor Germán Guzmán C.

    1967-06-01

    Full Text Available Monseñor Germán Guzmán ha escrito una Biografía apasionada, rencorosa, ácida de diatribas contra lo que llama el capitalismo, la burguesía que engorda, las clases que son inútiles para tomar determinaciones que transformen completamente la fisonomía de Colombia. Se conmueve, Monseñor con la sangre de los pobres del mundo, con la afrenta a los desheredados, contra un mundo que ha negado a Cristo. Y cifra y compendia en el sacerdote Camilo Torres Restrepo, toda la realidad de esa lucha.

  11. Determinación de las propiedades ópticas de materiales tipo composite utilizados en odontología

    OpenAIRE

    Carvalho Zavaglia, Cecília Amelia; López Palacio, Raúl Ernesto

    2000-01-01

    La determinación de las propiedades ópticas del obturante tipo composite, desarrollado en el Departamento de Ingenieria de los Materiales (FEM,UNICAMP), fue el objetivo fundamental del presente trabajo. El material en estudio es formado por la mezcla, de cantidades específicas, de polímeros acrílicos, iniciador, acelerador y relleno inorgánico de tamaño de partícula determinado. Las determinaciones fueron realizadas siguiendo las indicaciones descritas en la norma I.S.O. 4049 d...

  12. Costos privados de la educación superior universitaria

    OpenAIRE

    Carrizo, Alejandro Rogelio

    2015-01-01

    Algunos estudios relevantes en educación manifiestan que las decisiones que adoptan las familias o los individuos respecto a iniciar sus estudios universitarios están influenciadas por las condiciones socioeducativas y económicas en que se encuentren. Respecto del estudio de los fenómenos educativos desde un enfoque económico, la reciente Economía de la Educación se ha ocupado de realizar algunas determinaciones vinculadas a los costos de este sector, pero desde una mirada preemine...

  13. Curva de intensidad frecuencia y duración de inundaciones (IFD) para el municipio Venezuela, provincia Ciego de Ávila, Cuba

    OpenAIRE

    Oscar Brown Manrique; Yurisbel Gallardo Ballat; José E. Valdés

    2013-01-01

    La investigacion se desarrolló en el minicipio de Venezuela de la provincia de Ciego de Ávila, con el proposito de construir las curvas de intensidad frecuencia duracion de las inundaciones sobre la base de las precipitaciones efectivas de esa localidad y su ajuste a las funciones de Talbot y Aparicio. Se determinaron igualmente el índice de precipitación efectiva normal (IPN) de gran utilidad para la determinacion de la intensidad de este fenómeno. Los resultados demuestran que las precipita...

  14. Prevalencia de factores de riesgo para enfermedad cardiovascular en una muestra de pacientes con hipertensión arterial esencial: estudio descriptivo Prevalence of risk factors for cardiovascular disease in a sample of patients with essential hypertension: descriptive study

    OpenAIRE

    Solón Navarrete H; Diego Huertas R; Luis E Rozo M; Jorge E Ospina

    2009-01-01

    Introducción: la valoración del riesgo cardiovascular permite identificar los grupos en los cuales se debe dar prioridad a las actividades de prevención (primaria y secundaria) dirigidas a reducir la morbimortalidad cardiovascular. Metodología: se incluyeron 2.167 pacientes hipertensos colombianos (edad media: 62,6 años; de los cuales 56,4% eran mujeres y 43,6% hombres) a quienes su médico realizó una encuesta estructurada y registró los resultados del examen físico y de las determinaciones b...

  15. Idolos populares y literatura en América Latina

    Directory of Open Access Journals (Sweden)

    Carlos Monsiváis

    1984-01-01

    Full Text Available A lo largo del siglo se produce en América Latina una importante operación literaria, ideológica y social de resultas de la cual muchos de los límites y de las barreras impuestas por la así llamada "alta cultura" -la representación de lo mejor de Occidente- se derrumban, y una serie de factores considerados "vulgares, de mal gusto, indignos del mínimo a precio", ocupan un sitio fundamental en las determinaciones culturales.

  16. Investigación de cocaína y marihuana en meconio de neonatos atendidos en un hospital público: Primera experiencia realizada en la ciudad Córdoba, Argentina Screening of cocaine and marijuana in meconium of newborns from a public hospital of city of Córdoba, Argentina

    OpenAIRE

    Andrés Suárez; Alberto Peirano; Inés González; Edgar Odierna; Nilda Gait; Ruth Llebeilli; Cristian Hansen

    2009-01-01

    Se investigaron cocaína y marihuana en meconio de neonatos nacidos en la Maternidad Provincial de la Ciudad de Córdoba y se relacionaron los resultados con las semanas de gestación y los pesos al nacer. Las determinaciones se realizaron utilizando inmunoensayo y cromatografía gaseosa-espectrometría de masas. Se analizaron 48 muestras de meconio recolectadas durante un año (2007-2008). De los 48 meconios analizados, 17 correspondieron a neonatos masculinos y 31 a neonatos femeninos. Se procesa...

  17. Paisajes para un desarrollo sustentable y participativo

    Directory of Open Access Journals (Sweden)

    Rafael Mata Olmo

    2014-11-01

    Para terminar, el texto recoge una experiencia de proyecto territorial de paisaje, la del Plan Insular de Menorca (Islas Baleares, España, aprobado en 2003. Se sintetizan sus determinaciones sobre la protección de determinados terrenos por sus altos valores paisajísticos, sus directrices para que las políticas sectoriales (turismo, agricultura, infraestructuras, etc. incorporen criterios paisajísticos, y sus iniciativas para la gestión y mejora del paisaje y para el fomento del acceso público a su contemplación y disfrute.

  18. La movilidad en la formación inicial de maestros de lenguas extranjeras: El caso de un Prácticum Internacional

    OpenAIRE

    Sanz de la Cal, Esther

    2014-01-01

    La adopción del Prácticum Internacional como dispositivo de investigación proporciona, en su aplicación efectiva, un lugar de producción de conocimiento sobre el impacto de la movilidad en el marco formativo del Prácticum Internacional, para el desarrollo de un perfil europeo profesional del docente de lenguas extranjeras de Educación Primaria, en formación inicial. En la primera parte, se ha realizado un análisis retrospectivo, comparativo y evolutivo de las determinaciones y recomendacione...

  19. TOMA DE DECISIONES, ESTILOS DE COMUNICACIÓN EN EL CONFLICTO Y COMUNICACIÓN FAMILIAR EN ADOLESCENTES BACHILLERES

    OpenAIRE

    Alejandro Cesar A. Luna Bernal; Francisco A. Laca Arocena; Liliana Isabel Cedillo Navarro

    2012-01-01

    En este trabajo se analizan correlaciones significativas entre patrones de toma de decisiones, autoconfianza como tomador de determinaciones, patrones de comunicación familiar y estilos de mensajes en el manejo de conflictos con los padres en 412 adolescentes bachilleres con edades de entre 15 y 19 años, quienes respondieron una versión adaptada del Cuestionario de Estilos de Mensajes en el Manejo del Conflicto, el Cuestionario Melbourne de Toma de Decisiones y la Escala de Autoconfianza como...

  20. Evaluación global subjetiva y escala de malnutrición-inflamación para valorar el estado nutricional de pacientes en diálisis peritoneal con hipoalbuminemia Subjective global assessment and malnutrition-inflammation scale to assess the nutritional status of patients on peritoneal dialysis with hypoalbuminaemia

    OpenAIRE

    Sagrario Jiménez Jiménez; Francisca Muelas Ortega; Pilar Segura Torres; Francisco José Borrego Utiel; José Manuel Gil Cunquero; Antonio Liébana Cañada

    2012-01-01

    Los pacientes con insuficiencia renal crónica en diálisis peritoneal con frecuencia están mal nutridos o en riesgo de desnutrición, por sus especiales características y favorecido por múltiples factores, como otras patologías asociadas, diálisis inadecuada, estado inflamatorio, pérdida de nutrientes por el dializado, etc. Se han descrito numerosos métodos para evaluar el estado nutricional, siendo las medidas antropométricas y determinaciones de laboratorio las más utilizadas, pero cuando las...

  1. La Cromogranin A como marcador sérico en el diagnóstico, pronóstico y seguimiento del cáncer de próstata. Seguimiento de 10 años

    OpenAIRE

    Ruano Pérez, Ricardo

    2014-01-01

    [ES]Objetivo: Es un estudio prospectivo en el que se pretende establecer la utilidad de incorporar la determinación de la Cromogranin A como marcador sérico neuroendocrino en pacientes con cáncer de próstata, tanto en el momento del diagnóstico como en el seguimiento de los pacientes. Método: Se propone utilizar la Cromogranin A sérica de forma complementaria a los marcadores prostáticos convencionales en el diagnóstico y para el control evolutivo de los pacientes. Todas las determinacion...

  2. La incertidumbre de futuro y la estrategia empresarial

    Directory of Open Access Journals (Sweden)

    Carlos Jaime Buitrago Quintero

    2007-12-01

    Full Text Available Las decisiones estratégicas de las empresas están orientadas a definir las accionesque deben emprenderse para asegurar las condiciones de supervivencia, crecimientoy rentabilidad sostenida que se esperan. Tales determinaciones se crean bajo situacionesde incertidumbre, puesto que no se conocen las circunstancias de futurodel entorno empresarial.El propósito de los estudios prospectivos es identificar situaciones futuras y potencialesde negocio, para reducir las condiciones de incertidumbre con el fin deasumir las decisiones que tengan mayor posibilidad de éxito para la organización.

  3. Prevalencia de hepatitis viral tipo B en pacientes y personal de tres unidades de hemodiálisis en Lima.

    OpenAIRE

    BUSSALLEU, Alejandro; CIEZA, Javier; COLICHON, Alejandro; BERRIOS, Jorge

    2013-01-01

    Se estudiaron 103 pacientes y 41 miembros del personal médico y paramédico de tres centros de hemodiálisis en Lima, Perú, para determinar infección por hepatitis B. El antigeno de superficie de la hepatitis B(HBsAg) fue detectado en 21.36% de los pacientes y2.4% del personal. El anticuerpo de superficie (antiHBs) en 47.57% respectivamente. Las determinaciones de hicieron por el método de ELISA. En los pacientes la presencia de ambos marcadores no se relacionó a las transfusiones sanguíneas. E...

  4. Monitorización respiratoria del paciente pediátrico en la Unidad de Cuidados Intensivos

    OpenAIRE

    Alejandro Donoso; Daniela Arriagada; Dina Contreras; Daniela Ulloa; Megan Neumann

    2016-01-01

    La monitorización respiratoria representa un importante rol en el cuidado del niño con falla respiratoria aguda. Por tanto, su apropiado uso y correcta interpretación (reconociendo qué señales y variables deben ser priorizadas) deberían ayudar a un mejor entendimiento de la fisiopatología de la enfermedad y de los efectos de las intervenciones terapéuticas. Asimismo, la monitorización del paciente ventilado permite, entre otras determinaciones, evaluar diversos parámetros de la mecánica respi...

  5. Conservación de la cepa Lecanicillium lecanii en agua destilada estéril

    OpenAIRE

    Angela Ofelia Díaz Llanes; Teresita Lemes Rodríguez

    2009-01-01

    Se evaluó el método de preservación en agua destilada para el hongo entomopatógeno Lecanicillium lecanii, con el objetivo de definir sus posibilidades de aplicación en la conservación de este hongo. El estudio se realizó inoculando asépticamente las esporas en bulbos que contenían agua destilada estéril y fueron almacenados a temperatura ambiente y refrigeración. La efectividad del método fue evaluada mediante determinaciones de viabilidad, características macroscópicas y microscópicas del ho...

  6. Reference hematological values in Argentinian terrestrial turtle (Chelonoidis chilensis chilensis)

    OpenAIRE

    Troiano, Juan Carlos; Silva, M. C.

    1998-01-01

    Se tomaron muestras sanguíneas de 150 ejemplares sanos de tortuga terrestre argentina (Chelonoidis chilensis chilensis) por medio de punción de la vena coccígea superior. Las determinaciones que se realizaron incluyeron recuentos de glóbulos rojos, leucocitos y trombocitos, hematocrito, concentración de hemoglobina, índices hematimétricos y fórmulas leucocitarias relativas, las que se compararon con otras especies de Testudinidae. No se observaron cambios estadísticamente significativos en lo...

  7. La alimientación y la composición de la leche en explotaciones gallegas

    OpenAIRE

    Vázquez Yáñez, O.P.; Gónzalez Rodríguez, A.

    2006-01-01

    El contenido de urea en leche, de facil determinacion en los laboratories interprofesionales de leche, puede ser de uso generalizado como herramienta de diagnostico de la alimentacion de vacas lecheras en Galicia. Se revisan trabajos que relacionan la urea en la leche y en sangre con la produccion de leche por vaca y con la reproduccion del rebano. Un aspecto importante hoy es la relacion del nivel de urea en leche con el medio ambiente. Se puede prevenir el exceso de aporte de N (detectado e...

  8. Estudio para el mejoramiento de la calidad analítica en la determinación de hierro sérico en laboratorios de análisis bioquímicos

    OpenAIRE

    Cailliat, María Cristina

    2011-01-01

    En diversas condiciones, la medición de hierro sérico es fundamental para estudiar el “estado del hierro del paciente”. Este estudio comprende una serie de determinaciones básicas que permite conocer, en primera instancia, si el paciente presenta un déficit o un exceso de este analito. La carencia de hierro es la deficiencia nutricional de mayor prevalencia en todo el mundo, y su evaluación temprana, especialmente en niños y embarazadas, evita retrasos en el desarrollo intelectual del recién ...

  9. Cribado de cáncer de cérvix: ¿merece la pena la búsqueda activa?

    OpenAIRE

    Ángeles Morales Martínez; Lorena Blanco Rodríguez; Cristina Morales Martínez; Sonia Tejuca Somoano

    2015-01-01

    Objetivos: Conocer el porcentaje de mujeres que han realizado una citología en los últimos 5 años y el ámbito de realización. Detectar alteraciones citológicas precursoras de cáncer de cérvix en mujeres sin cribado o con cribados inadecuados y conocer la prevalencia de determinaciones de VPH positivas. Diseño: Estudio descriptivo transversal. Emplazamiento: Centro de Salud de Natahoyo, Gijón. Participantes: Mujeres de 40 a 50 años residentes en la zona básica y adscritas al centro de...

  10. El contexto importa: reflexiones acerca de cómo los contextos y la composición escolar afectan el rendimiento y la experiencia educativa de los estudiantes

    OpenAIRE

    Balarin, María

    2016-01-01

    El punto de partida de este balance es la idea de que, en sistemas complejos como el educativo, los resultados son producto de interacciones dinámicas entre actores, contextos —culturales, sociales e institucionales— y políticas, por lo que resulta imposible reducir los resultados a un conjunto singular, específico y replicable de determinaciones. El balance busca profundizar en esta idea explorando la forma en que los contextos influyen en el rendimiento educativo de los estudiantes. Para el...

  11. Contenido de vitamina C en zumos de frutas envasados y naturales. Práctica de laboratorio interactiva.

    OpenAIRE

    Milla González, Miguel; Espada Bellido, Estrella

    2016-01-01

    En esta práctica de laboratorio simulada se aplica el método oficial (método del 2,6-diclorofenolindofenol) para determinar el contenido en vitamina C (ácido ascórbico) en un zumo. Hay tres opciones de análisis: contenido en vitamina C en un zumo de marca comercial, contenido en vitamina C en un zumo de marca blanca y contenido en vitamina C en el zumo natural de naranja. Para cada caso, se hacen cinco determinaciones y se calcula el valor medio de vitamina C expresado en mg por 100 mililitro...

  12. Forecasting con Machine Learning y Deep Learning

    OpenAIRE

    Espeleta, Carlos

    2018-01-01

    Cada vez más empresas necesitan buenas determinaciones futuras de su demanda. Muchas empresas disponen de sistemas basados en técnicas clásicas, disponibles en software como SAS, IBM o Excel. Este proyecto pretende explicar cómo segmentar el porfolio de productos para entender de que forma se pueden reducir costes y de- terminar donde dedicar más recursos. Además se compararán diferentes técnicas para determinar predicciones, empezando por modelos de series temporales. Des- pués se analizarán...

  13. Efectos de los Bicarbonatos contenidos en el agua de riego sobre el suelo

    Directory of Open Access Journals (Sweden)

    Luis Fuentes Aguilar

    1969-06-01

    Full Text Available La acción de los bicarbonatos en el agua de riego sobre las propiedades químicas y físicas de los suelos, es conocida desde hace varios años pero no se le ha dado toda la importancia que requiere. Esto es debido a que las propiedades de los suelos se deben, principalmente, a los cationes solubles e intercambiables que se acumulan en ellos. Por otra parte, en la mayoría de las zonas afectadas por excesivas acumulaciones de sales por el agua de riego, las determinaciones que se efectúan, normalmente, son de cloruros y sulfatos.

  14. Edipo temprano, «Nachtráglichkeit» y conflicto psíquico.

    OpenAIRE

    Jaime Szpilka

    1982-01-01

    En nuestra teoría y en nuestra clínica nos enfrentamos cotidianamente con la cuestión acerca de si las determinaciones eficaces en la génesis del conflicto psíquico, la manera de comprender el material de nuestros pacientes y la instrumentación efectiva de la cura deben o no pasar necesariamente por la mediación estructurante de lo que FREUD denominara el complejo nuclear de las neurosis, es decir el complejo de Edipo. Si esta mediación no constituyera necesidad tendríamos derecho de establec...

  15. Algoritmo para generar formulas de características geométricas de las secciones planas, su implementación en DERIVE // Algorithm for the calculation of the geometric characteristics of the plane sections defined for polygonal, their implementation in DERI

    Directory of Open Access Journals (Sweden)

    Rolando Rivero-Galán

    2010-01-01

    Full Text Available ResumenEn la esfera del diseno de estructuras y de elementos de maquinas, se presenta con relativafrecuencia el calculo de determinadas caracteristicas o propiedades geometricas de seccionesplanas, como son entre otras: el area de una seccion transversal, el centro de gravedad, unmomento de inercia o mas general la determinacion de alguna caracteristica geometrica definidapor una integral doble extendida en la region del plano que ocupa la seccion, pieza o elemento.El presente trabajo tiene como objetivo la confeccion de un programa para computadora,utilizando el asistente matematico DERIVE, para la determinacion de las caracteristicas geometricasde secciones planas cuyo contorno este constituido por segmentos de rectas.Palabras claves: Algoritmo, seccion plana, DERIVE, momentos, centro de gravedad.______________________________________________________________AbstractIn the sphere of the design of structures, is relative frequency the calculation of certaincharacteristic or geometric properties of plane sections, like: the area of a traverse section, thecenter of gravity, a moment of inertia or more general the determination of some geometriccharacteristic defined by a double integral extended in the region of the plane that occupies thesection, piece or element.The present work has as objective the making of a program for computer, using the mathematicalassistant DERIVE, for the determination of the geometric characteristics of plane sections whosecontour this constituted by segments of right.Key words: Algorithm, plane section, DERIVE, moments, center of gravity

  16. Análisis sobre las decisiones de los contratistas para licitar en la industria de la construcción palestina Analysis of contractors' bidding decision in the Palestinian construction industry

    Directory of Open Access Journals (Sweden)

    Adnan Enshassi

    2010-08-01

    Full Text Available Ambas, la determinación de licitar y la determinación del precio a licitar son muy importantes para cada contratista. La importancia de estas determinaciones descansa en el hecho que, el éxito o fracaso del negocio contratista, depende de los resultados derivados de tales determinaciones. El objetivo de este artículo es identificar y analizar los factores que, se estima, afectan las determinaciones de licitar y del margen de utilidad en la industria de la construcción de la Franja de Gaza. Una encuesta, tipo cuestionario, reveló las respuestas de 77 contratistas generales. Los resultados indicaron que la mayoría de los contratistas depende de procesos subjetivos para tomar la determinación de licitar o no licitar, y para las determinaciones de margen de utilidad, fundamentados en un juicio basado en la experiencia. Algunos factores son considerados importantes en ambas determinaciones, mientras que otros factores son considerados importantes sólo para un tipo de determinación y no para la otra. Los grupos más importantes que afectan la licitación/no licitación y el margen de utilidad, resultaron ser el grupo "cliente y consultor del proyecto" y el grupo "Condiciones del proyecto que contribuyen a la rentabilidad del mismo". Los resultados también indicaron que, la capacidad financiera actual del cliente, tamaño del proyecto y la situación financiera de la empresa, constituyen factores principales para decidir si licitar o no licitar. Con relación a la determinación de margen de utilidad, se determinó que la duración del proyecto, el ambiente político y los plazos de pago constituyen los principales factores que afectan la determinación de margen de utilidad. Este estudio proporciona algunas recomendaciones.Both the bid decision and the determination of the bid price are very important to every contractor. The importance of such decisions lies in the fact that, the success or failure of a contractor's business depends on the

  17. Estudio electrofisiológico de la funcion neuromuscular en una poblacion intoxicada con plomo

    Directory of Open Access Journals (Sweden)

    O. M. Genovese

    1988-03-01

    Full Text Available Un grupo de 12 pacientes con cifras elevadas de plombemia y disminuidas de ALA D fueron estudiados electrofisiológicamente. Se efectuaron las siguientes determinaciones: amplitud de potencial evocado muscular; latencia distal motora; velocidad de conducción motora en los nervios mediano, ciático poplíteo externo y radial; velocidad de conducción sensitiva y amplitud del potencial evocado sensitivo de nervio en el mediano; exploración electromiográfica convencional; estudio de la transmisión neuromuscular, mediante estimulación repetitiva del nervio ciático popliteo externo a diversas frecuencias, con registro de la amplitud del potencial en músculo tibial anterior. Los datos obtenidos fueron comparados con controles. Se buscaron correlaciones entre las determinaciones bioquímicas y los diferentes hallazgos electrofisiológicos que a su vez se correlacionaron entre si y también con el tiempo de evolución de la intoxicación. Los hallazgos pusieron de manifiesto la presencia de neuropatía axonal junto a moderada desmielinización. La exploración de la transmisión neuromuscular mostró ocasional decremento o incremento de la amplitud del potencial muscular evocado, hechos que suponen cierta participación de la unión neuromuscular. Se halló correlación solamente entre disminución de ALA D y la disminución de las amplitudes del potencial sensitivo del mediano y el evocado muscular del mismo nervio y con la disminución de la VCM del nervio radial. Una débil relación se observó entre el tiempo de exposición y la disminución de la VCS del nervio mediano y VCM del radial. Las determinaciones bioquímicas y el tiempo de exposición transcurridos no probaron ser parámetros sensibles para determinar el grado de afectación del sistema nervioso periférico. El conjunto do hallazgos sugiere que el desarrollo de la neuropatía puede estar ligado a factores individuales de predisposición al daño nervioso.

  18. Solvents orgànics en electroforesi capil·lar i cromatografia de líquids

    OpenAIRE

    Subirats i Vila, Xavier

    2007-01-01

    La cromatografia de líquids d'alta eficàcia (HPLC) és la tècnica de separació més àmpliament utilitzada, degut a la seva sensibilitat, exactitud de les determinacions quantitatives i aplicabilitat a anàlits no volàtils o termolàbils d'interès científic i industrial. L'electroforesi capil·lar juga un paper fonamental en bioquímica. Aquesta tècnica permet obtenir anàlisis ràpides amb una elevada resolució i un baix consum de reactius auxiliars, fet que minimitza la generació de residus. L'objec...

  19. La calidad del agua destilada en la determinación de cenizas conductimétricas en azúcares crudos

    OpenAIRE

    Roberto J Rodríguez-Mambuca; Julián Rodríguez-López; Armando Perdomo-Morales

    2013-01-01

    Se llevaron a cabo experimentos de determinaciones en paralelo de muestras de azúcar crudo usando el método de ceniza conductimétrica del ICUMSA 2007, con agua de conductividad de 2 μ Siemens/cm y una réplica utilizando agua destilada en el intervalo de 2 a 10 μ Siemens/cm, para evaluar la posibilidad de sustituir el agua de conductividad exigida por la técnica analítica por agua destilada común en estos análisis. Se evaluó estadísticamente el conjunto de 58 muestras pareadas y de este anális...

  20. Política de vivienda como determinante de la segregación residencial en la ciudad de Ibagué, Colombia

    Directory of Open Access Journals (Sweden)

    Alexandra López Martínez

    2017-12-01

    Full Text Available El fenómeno de la segregación es inherente al sistema de producción capitalista, en donde los procesos económicos (sector privado, políticos (el Estado e ideológicos, son los que determinan cómo se ocupa el espacio urbano. En este sentido el objetivo de este trabajo es indagar sobre las determinaciones económicas, políticas e ideológicas que han influenciado en el surgimiento de este fenómeno en Ibagué, para ello se hace un análisis por fases desde comienzos del siglo XX hasta el año 2017, teniendo como referencia lo acontecido a manera general en Colombia y que haya tenido influencia o no en el municipio en mención.

  1. Operation of industrial electrical substations. Part II: practical applications

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez Jimenez, Juan J; Zerquera Izquierdo, Mariano D; Beltran Leon, Jose S; Garcia Martinez, Juan M; Alvarez Urena, Maria V; Meza Diaz, Guillermo [Universidad de Guadalajara (Mexico)]. E-mails: cheosj@yahoo.com; mdzi@hotmail.com; beltran5601@yahoo.com.mx; jmargarmtz@yahoo.com; victory_alvarez@telmexmail.com; depmec@cucei.udg.mx

    2013-03-15

    The practical application of the methodology explained in Part 1 in a Cuban industry is the principal objective of this paper. The calculus of the economical operation of the principal transformers of the industrial plant is shown of the one very easy form, as well as the determination of the equations of the losses when the transformers operate under a given load diagram. It is calculated the state load which will be passed to the operation in parallel. [Spanish] El objetivo principal de este trabajo es la aplicacion practica de la metodologia, en una industria cubana, que se explico en la Parte 1. El calculo de la operacion economica de los principales transformadores de la planta industrial se muestra de una forma muy facil, asi como la determinacion de las ecuaciones de las perdidas cuando los transformadores operan bajo un diagrama de carga dado. Se calcula la carga de estado que se pasa a la operacion en paralelo.

  2. Remarks on the proportioning of cements in set mortars and concretes

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    Calleja, J.

    1966-03-01

    Full Text Available Not availableLos métodos al uso para determinar la dosificación de conglomerantes en conglomerados, y más concretamente de cemento (portland o no en morteros y hormigones fraguados, tienen en general limitaciones que les hacen adolecer, en la mayoría de los casos prácticos, de errores considerables. En circunstancias determinadas generalmente imprevistas, estos errores pueden aumentar notablemente e invalidar los resultados y las conclusiones que de los mismos pudieran extraerse. En evitación de ello es preciso entonces complementar los métodos con otras determinaciones, particularmente si el dictamen basado en el resultado hallado para la dosificación puede afectar seriamente a intereses económicos, o determinar una responsabilidad de cualquier tipo.

  3. La figura del llunk’u y el clientelismo en la Bolivia de Evo Morales

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    Gaya Makaran

    2016-06-01

    Full Text Available El artículo pretende examinar el fenómeno del clientelismo en los gobiernos del Movimiento al Socialismo (MAS en la Bolivia actual (2006-2015, como una herramienta de cooptación y neutralización de los movimientos sociales. Se analizará el contexto socio-histórico del fenómeno clientelista en Bolivia, tomando en cuenta las determinaciones culturales. Por lo cual el clientelismo boliviano se inscribirá en el concepto local del “llunk’u” o “llunkerío”, relacionado con el mundo aymara-quechua. Se mostrarán los mecanismos estructurales del poder político en Bolivia que llevan al clientelismo y paternalismo estatal y sus consecuencias para la autonomía de los movimientos sociales y la calidad de la vida política del país.

  4. Validación del método para la determinación de número de onda por ft-ir en películas de poliestireno

    OpenAIRE

    Herrera-Basurto, Raúl; Mercader-Trejo, F.; Martínez Suárez, F.

    2013-01-01

    Se utilizó la Guía EURACHEM “The Fitness for Purpose of Analytical Methods”1, para realizar la validación del método empleado en la determinación del número de onda de películas de poliestireno. Las películas de poliestireno son patrones utilizados en la calibración de la escala de número de onda de espectrómetros infrarrojos con transformada de Fourier (FT-IR), también son usados para el control de calidad en las determinaciones por FT-IR. La guía señala que tiene como fin pri...

  5. La violencia escolar como régimen de visibilidad

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    Oscar Fernando Forero-Londoño

    2011-01-01

    Full Text Available Este escrito aborda los discursos sobre la violencia escolar y los asume como regímenes de visibilidad que se construyen históricamente. Además, expone de manera esquemática cómo son asumidas las nociones de juventud, cultura escolar y cultura juvenil en los estudios sobre la violencia escolar. Reflexionar sociológicamente sobre las diversas formas de definir la violencia escolar y su relación con las poblaciones en condición juvenil implica asumir que las determinaciones analíticas de estas categorías coadyuvan a conservar o transformar la realidad y que, en consecuencia, la mirada del investigador social es una mirada al mismo tiempo política.

  6. La fórmula del cuerpo sin órganos una aproximación Bergsoniana a su enunciación

    OpenAIRE

    Ruiz Stull, Miguel

    2011-01-01

    Tomada desde Artaud por Deleuze ya desde la redacción de Lógica del sentido (1969), la expresión de cuerpo sin órganos (CsO) no deja de causar al menos perplejidad. En su enunciación se traman puntos cruciales de la filosofía de Deleuze desde su teoría del acontecimiento y de la diferencia, pasando por una definición y una analítica del deseo, hasta una determinada noción de vida que articularía el proceso de su generación. Sin desestimar lo anterior y los profusos usos y determinaciones actu...

  7. La metáfora de lo uno-múltiple: una (re-conceptuación dialógica de la identidad personal (una crítica al reduccionismo ?posmodernista?

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    Marcos Engelken Jorge

    2005-05-01

    Full Text Available En este trabajo pretendo corregir algunos de los ?excesos? y simplificaciones de las teorías posmodernistas sobre la identidad. Trato de restituir al sujeto una ontología que no lo reduzca a meras determinaciones sociales, recuperar su carácter corpóreo-orgánico (embodiment para su comprensión/construcción y, de este modo, retomar la cuestión de la unidad del sujeto (y de la unidad de/en su identidad frente a la manida exaltación de su fragmentación (pluralidad de su identidad; en oposición a lo cual sostengo la idea de una ?pluralidad de/en su identidad?.

  8. Corrosion detection and monitoring in steam generators by means of ultrasound; Deteccion y monitoreo de corrosion por medio de ultrasonido en generadores de vapor

    Energy Technology Data Exchange (ETDEWEB)

    Chacon Nava, Jose G.; Calva, Mauricio [Instituto de Investigaciones Electricas, Cuernavaca (Mexico); Fuentes Samaniego, Raul [Universidad Autonoma de Nuevo Leon (Mexico); Peraza Garcia, Alejandro [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1987-12-31

    The tube and component failures in steam generators due to corrosion cause huge economical losses. In this article the internal corrosion processes (hydrogen attack) and high temperature corrosion are described, as well as the ultrasound techniques used for its detection. The importance of obtaining corrosion rates, which are fundamental parameters for the detection of the tube`s residual life. The purpose is to prevent possible failures that would diminish the power plant availability. [Espanol] Las fallas de tuberia en componentes de generadores de vapor debidas a corrosion ocasionan considerables perdidas economicas. En este articulo se describen los procesos de corrosion interna (ataque por hidrogeno) y corrosion en alta temperatura, asi como tecnicas de ultrasonido empleadas para su deteccion. Se destaca la importancia de obtener valores de velocidad de corrosion, que es un parametro fundamental para la determinacion de la vida residual de tuberias. El proposito es poder prevenir posibles fallas que disminuyan la disponibilidad de centrales termoelectricas.

  9. MODELO DE GESTION DE MANEJO COSTERO INTEGRADO EN EL ECUADOR

    Directory of Open Access Journals (Sweden)

    Vladimir Soria

    2016-04-01

    Full Text Available Se ha estudiado el manejo costero integrado como una forma de gobernanza ambiental en la provincia de Santa Elena que incluyen dos aspectos: fortalecimiento institucional y participacion ciudadana. El deficiente control ambiental existente exige un modelo de gestión a escala local basado en tres ejes: el fortalecimiento de las capacidades institucionales de los gobiernos locales; el ordenamiento territorial para una adecuada determinacion y delimitacion de las competenecias en materia ambientak  costera y la participacion ciudadana a nivel del régimen de la comunas en coordinación con los distintos niveles de gobierno. Se propone el estudio delas caracteristicas específicasde cada comua ubicada en la faja costera para implementar en cada una de ella el respectivo modelo de gestion. Tambien se propone la creación de un obeservatorio de manejo costero integrado para medir el avance en manejo costero iuntegrado de la provincia de Santa Elena.

  10. MODELO DE GESTION DE MANEJO COSTERO INTREGADO EN EL ECUADOR

    Directory of Open Access Journals (Sweden)

    Vladimir Soria

    2016-04-01

    Full Text Available Las zonas costeras son espacios en los que se desarrollan importantes actividades económicas que generan presiones e impactos sobre el medio ambiente, lo cual requiere respuestas por parte de sector público y privado para garanatizar la sostenibilidad en la gestion de sus recursos. El manejo costero integrado como propuesta de gobernanza incluye dos caminos: fortalicimiento institucional y participacion ciudadana. El presente artículo propone un modelo de gestion a escala local basado en tre ejes: el fortalecimiento de las capacidades institucionales de los gobiernos locales; el ordenamiento territorial para una adecuada determinacion y deliitacion de las competencias en materia ambientala costera  y la participacion ciudadana a nivel del régimen de las comunas en coordinación con los distintos niveles de gobierno.  Un total de 26 comunas costeras con estudiadas y se presentan resultados para evaluar el grado de cumplimiento de los objetivos de desarrollo.

  11. Los Nogales, nueva fauna de vertebrados del Mioceno medio de Madrid

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    Morales, J.

    2006-12-01

    Full Text Available A new vertebrate fauna from the Middle Aragonian (Middle Miocene of the city of Madrid is presented. A description of the stratigraphic framework and the field campaigns carried out on this fossiliferous locality are included. The preliminary studies have allow the taxonomic assignations included on this work. The evolutionary stage of several taxa recorded in the locality allowed its correlation to the Middle Aragonian Biozone Dc.Una nueva fauna de vertebrados del Aragoniense medio (Mioceno medio del área urbana de Madrid es presentada. Se incluye una descripción del contexto estratigráfico del yacimiento y las excavaciones que se han realizado en esta localidad fosilífera. Los estudios preliminares han permitido realizar las determinaciones taxonómicas incluidas en el trabajo. El estado evolutivo de algunos de los taxa registrados en esta localidad ha permitido su correlación con la Biozona Dc del Aragoniense medio.

  12. La simulación

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    Alfonso Hanssen

    1968-01-01

    Full Text Available El hecho por el cual el hombre, debido a sus propias fuerzas y a los mecanísmos de que está dotado, se siente un ser extraño de naturaleza, deberá servirnos de ángulo visual o de punto de referencia para el estudio de la simulación. Porque no es la extrañeza apoderada de su ser un simple sinónimo de simulación , de tal suerte que el comportamiento tuviese razón de ser únicamente en el contexto de la biología, a decir, en la particularidad inminente de un acontecer en donde se escapan las determinaciones esxteriores que lo transforman.

  13. La desatención y la hiperactividad en los niños como modo de manifestar el sufrimiento psíquico

    Directory of Open Access Journals (Sweden)

    Beatriz Janin

    2013-11-01

    Full Text Available Este trabajo es resultado de una investigación en curso sobre los niños desatentos e hiperactivos. Se plantea el tema del diagnóstico en la infancia, diferenciando diagnosticar y catalogar. Se desarrollan teóricamente algunas de las determinaciones de la hiperactividad en la infancia, considerando que en muchos de estos niños se encuentran alteraciones en momentos fundantes de la constitución psíquica. This work is the result of an ongoing investigation into inattentive e hyperactive children. The subject of diagnosis in childhood is examined, and a distinction is made between diagnosis and classification. Some of the determinations of hyperactivity are discussed from a theoretical point of view. It is maintained that many of these children can be found to have suffered disturbances at crucial moments of their psychical constitution.

  14. La política de la guerra sin estado de guerra

    Directory of Open Access Journals (Sweden)

    Gisela Daza y Mónica Zuleta

    1998-04-01

    Full Text Available ¿Es el desplazamiento forzoso un efecto local del conflicto interno colombiano? Explicitar los elementos que constituyen el fenómeno de violencia generalizada requiere romper con las visiones que los encadenan a las determinaciones de su territorialidad. Por ello creemos que situarse en la intersección global-local posibilita analizar nuestro transcurrir en el conjunto de relaciones que articulan aOccidente, describiendo de manera simultánea los modos como lo particular y lo regular se componen en él. Este artículo intenta plantear hipotéticamente algunos de los efectos que tal articulación produce para la comprensión del fenómeno de los desplazados en el concierto de la violencia generalizada.

  15. La Ciudadanía en las Constituciones Mexicanas del Siglo XIX: Inclusión y Exclusión Político-Social en la Democracia Mexicana La Ciudadanía en las Constituciones Mexicanas del Siglo XIX: Inclusión y Exclusión Político-Social en la Democracia Mexicana

    Directory of Open Access Journals (Sweden)

    Graciela Velázquez Delgado

    2012-02-01

    Full Text Available En la sociedad decimonónica mexicana se fueron gestando desde la Independencia pretensiones de instituir una nueva nación y con ella una nueva organización del Estado. Sin embargo, no es posible hablar acerca de la construcción de la ciudadanía sin reconocer que dicha organización se dio en circunstancias muy desiguales para los individuos y que además quienes construyeron el concepto y lo enmarcaron constitucionalmente siempre tuvieron en mente la exclusión de la mayor parte de la población. En estas circunstancias, la ciudadanía surge como una categoría que incluye no sólo determinaciones políticas, sino también valores y determinaciones de tipo económico, social y cultural en su sentido más amplio. During the nineteenth century, Mexican society was moving toward the formation of a new nation and with it, a new organization of the State. However, it is not possible to speak of the creation of citizenship without acknowledging that this was carried out under circumstances which were very unequal for the individuals concerned: those who developed this concept and framed it in the Constitution always had in mind the exclusion of a majority of the population. Under these circumstances, citizenship emerges as a category that includes not only specific policies, but also values and standards of economic, social, and cultural natures, in their broadest sense.

  16. Estimation of the resource for small, mini and micro hydro-energy: Applications in Mexico. First part: Estimation of the Resource (Annexe 8 in 'A vision of year 2030 on the use of the renewable energies in Mexico'); Estimacion del recurso para pequena, mini y micro hidroenergia: Aplicaciones en Mexico. Primera parte: Estimacion del Recurso (Anexo 8 en 'Una vision al 2030 de la utilizacion de las energias renovables en Mexico')

    Energy Technology Data Exchange (ETDEWEB)

    Valdez Ingenieros, S.A. de C.V. [Cuernavaca, Morelos (Mexico)

    2005-08-15

    In this document a discussion is presented on the potential denominated small, mini or micro-hydraulic whereupon counts the country with the intention of coming to its development or operation. The use of hydro-energy in small scale is possible as much as for the auto-industrial supply as for productive activities in rural areas. Comments also made on the uncertainties of its assessment and the way it considers to follow to continue with the works that take to conclude at 100% the assessment of the national potential in the near future, since apparently in Mexico a little more of 2% of such potential has been only developed. One knows that in other countries in the last ten years, an accelerated development of this power source with satisfactory results has been obtained. [Spanish] En este documento se presenta una discusion sobre el potencial denominado pequeno, mini o micro hidraulico con que cuenta el pais con el objeto de proceder a su desarrollo o explotacion. El uso de la hidroenergia en pequena escala es posible tanto para el auto abasto industrial como para actividades productivas en el medio rural. Se comenta tambien sobre las incertidumbres de su determinacion y se plantea el camino a seguir para continuar con los trabajos que lleven a concluir al 100% la determinacion del potencial nacional en el futuro cercano, ya que al parecer en Mexico solo se ha desarrollado un poco mas del 2% de dicho potencial. Se sabe que en otros paises en los ultimos diez anos, se ha logrado un acelerado desarrollo de esta fuente energetica con resultados satisfactorios.

  17. Simple method of dynamic Young’s modulus determination in lime and cement mortars

    Directory of Open Access Journals (Sweden)

    Rosell, J. R.

    2011-03-01

    Full Text Available The present work explains a simple method to determine the dynamic Young module (MOE by inducing a set of small mechanical perturbation to samples of lime and cement mortars and correlating the results obtained with results determined using other techniques and methods. The procedure described herein follows the instructions stated in the UNE-EN ISO 12680-1 standard for refractory products although in this study the instructions are applied to standardized RILEM 4x4x16 cm test samples made of lime and cement mortars. In addition, MOE determinations are obtained by using ultrasonic impulse velocity while static Young's modulus determinations are obtained by performing conventional bending tests. The ability of this procedure to correlate with results from other techniques, along with its simplicity, suggests that it can be widely adapted to determine the deformability of mortars under load using standardized samples.

    El presente trabajo muestra un método simple para determinar el módulo de Young dinámico (MOE a partir de pequeñas perturbaciones mecánicas producidas a probetas de mortero de cal y de cemento, correlacionando los resultados obtenidos con las correspondientes mediciones realizadas con otras técnicas. El procedimiento sigue básicamente las instrucciones fijadas en la norma UNE-EN ISO 12680-1 de productos refractarios, pero aplicándolo a probetas normalizadas RILEM 4x4x16 de morteros confeccionados con cal y cemento. Paralelamente se realizan determinaciones del MOE a partir de la velocidad de paso de impulsos ultrasónicos y determinaciones del módulo de Young estático a partir de ensayos de flexión convencionales. La simplicidad del método aplicado y la correlación de los resultados obtenidos con las variables medidas permiten concluir que esta metodología es de aplicación directa para determinar la deformabilidad bajo carga de los morteros a partir de probetas normalizadas.

  18. Plaguicidas y cáncer de mama en mujeres cordobesas

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    R. Angulo Lucena

    2001-06-01

    Full Text Available La exposición a contaminantes ambientales constituye en la actualidad un problema importante en salud pública, sobre todo con respecto al papel que dichos tóxicos juegan como carcinogenéticos. Este hecho junto con la incidencia creciente del cáncer de mama en España y de que no existe una relación clara entre esta patología y la exposición a plaguicidas, conduce a plantearnos evaluar el papel de los plaguicidas como factor de riesgo en el cáncer de mama en mujeres cordobesas.Se realiza un estudio de casos-controles en 134 mujeres que fueron sometidas a intervenciones quirúrgicas por lesiones mamarias en el Hospital Universitario Reina Sofía de Córdoba. A todas se les realiza un cuestionario, así como un estudio anatomopatológico y determinaciones en grasa mamaria de cuatro plaguicidas (HCB, HCH, p,p’DDE y Aldrín mediante cromatografía de gases.Tras el estudio anatomopatológico se estableció que 69 presentaban lesiones malignas (casos y 65 lesiones benignas (controles. Las determinaciones analíticas respecto a los 4 plaguicidas, detectan niveles elevados de p,p’DDE en todas las muestras, seguidas del HCB y Aldrín y en menores niveles y muestras se detecta el HCH.El análisis univariante detectó la edad, duración de la lactancia y niveles de Aldrín como factores de riesgo en las lesiones malignas, pero el análisis multivariante identificó los niveles del pesticida Aldrín como el factor más significativo en dichas lesiones (p < 0.001.Se establece la relación causal entre Aldrín y cáncer de mama, y se sugiere la necesidad de realizar nuevos estudios para eliminar los factores de confusión.

  19. Acidez y peso específico de la leche de cabra de un grupo de capricultores de la Meseta Central costarricense

    Directory of Open Access Journals (Sweden)

    Alejandro Chac\\u00F3n Villalobos

    2004-01-01

    Full Text Available Acidez y peso específico de la leche de cabra de un grupo de capricultores de la Meseta Central costarricense. El estudio fue efectuado en la Estación Experimental Alfredo Volio Mata de la Universidad de Costa Rica y en la Asociaci ón Costarricense de Criadores de Cabras localizadas en el Alto de Ochomogo de Cartago. La leche de cabra de siete productores fue evaluada desde el primero de junio hasta el 31 de diciembre de 2002. El peso en kg, la acidez en grados Dornic y el peso específico de la leche fueron registrados diariamente. Se determinó un valor característico de 17,7 ± 0,3 ºD para la acidez y de 1,03 ± 0,002 para el peso específico. Aná- lisis de varianza seguidos de una prueba post hoc de Scheffé se efectuaron para evaluar posibles variaciones en la acidez o el peso específico a lo largo de los meses para todos los datos sin importar el origen de la leche. Igualmente se evaluaron posibles variaciones en las mismas variables para cada uno de los productores y entre ellos a lo largo de los meses. Los resultados obtenidos en todos los casos mostraron que no existieron diferencias en todas las determinaciones evaluadas para acidez (P≤0,05. Para el peso específico si se detectaron diferencias significativas (P≤0,01 en todas las determinaciones evaluadas. Al correlacionar el peso específico y la acidez de todos los datos se obtuvo un coeficiente de correlación de 0,03, lo cual hace imposible argumentar la existencia de alguna relación proporcional entre estas dos variables. Al correlacionar la cantidad de leche producida con el peso específico se obtuvo un coeficiente de correlación de -0,67.

  20. Generalidades sobre Rocas y Análisis Químicos de Suelos.

    Directory of Open Access Journals (Sweden)

    Orozco R. Aycardo

    1940-03-01

    Full Text Available Desde el día en que inicie el presente trabajo, apoyado por la amable circular que me proporcionó el Rector de la Facultad Nacional de Agronomía, el Jorge Gutiérrez, para dirigirme a diversos lugares del país en solitud de material que me sirviera para poner en práctica los diversos métodos que me fuere dado ejecutar, no tuve otro objetivo que el de reunir el mayor número posible de métodos, para hacer un análisis químico del suelo. Tenía el pleno convencimiento de que nada nuevo iba a aportar a las ciencias químicas, pero en cambio, como me lo sugirió el que más tarde designé como Presidente de Tesis, doctor Antonio Durán A., si podría compilar una serie de métodos explicados en un lenguaje tan sencillo, como en texto alguno pudiera presentarse. Entonces nació en mí el deseo de proporcionar a los estudiantes venideros un texto elemental sobre principios de análisis de algunos elementos de importancia agronómica, el cual no lo dudo me ha quedado defectuoso, pero estoy seguro que, el ser corregido por el Profesor respectivo, tendrá el valor a que yo aspiro. Con gran delicadeza he practicado los sistemas de análisis que anoto, procurándome así una experiencia que si es corta en realidad de verdad, si me permite diferenciar los diversos métodos de determinaciones, basado en la bondad de resultados verificados en muchas ocasiones. No creyendo tanto en la influencia del factor personal cuanto es la bondad del método, he resuelto acogerme hasta el conocimiento de nuevos y más eficientes, a los siguientes para las determinaciones de elementos, partiendo de soluciones clorhídricas.

  1. Variaciones seculares de período en las RR Lyrae de ω~Centauri

    Science.gov (United States)

    Marraco, H. G.; Milesi, G. E.

    Utilizando 689 observaciones de 35 estrellas RR Lyrae del cúmulo globular ω Centauri hemos obtenido nuevas determinaciones de sus períodos y sus correspondientes variaciones seculares. Las observaciones fueron obtenidas de la literatura con la excepción de un grupo 66 determinaciones que se presentan por vez primera aquí. Utilizando el parámetro testigo σ descripto en Marraco & Muzzio (Publ. Astron. Soc. Pacific 92, 700, 1980), hemos realizado un ajuste bidimensional en P y β (donde β es la variación secular del período). Con este fin la totalidad de las 689 observaciones fueron llevadas a un sistema fotométrico común. Para esto se realizó un cuidadoso análisis de los numerosos errores en la identificación de las estrellas de las series de comparación. Los resultados de los ajustes bidimensionales fueron analizados utilizando técnicas de procesamiento de imágenes. Con este fin el parámetro de ajuste σ fue representado como función de P y β. En las imágenes resultantes se buscaron los mínimos y al menor de ellos se lo aceptó como período instantáneo verdadero y su variación secular β. La determinación precisa de cada parámetro se realizó mediante ajuste de gaussianas y se determinaron sus errores. A modo de ejemplo la variable #8 fue analizada en una matriz de 501 × 501 elementos representando el parámetro σ para valores comprendidos entre 0,521034 valores el parámetro testigo resulta σ= 0,127 . Si no se tiene en cuenta la variación secular del período y se busca aquél de mejor ajuste para β = 0, se obtiene P = 0,5212960 días, pero entonces el parámetro de ajuste resulta tan alto como σ = 0,23 .

  2. Water quality in a lagoon in the southeast pampa region of Argentina Calidad del agua en una laguna del sudeste pampeano (Argentina

    Directory of Open Access Journals (Sweden)

    C. Fernández

    2007-03-01

    Full Text Available This work evaluates the chemical and bacteriological qualities of the recreational waters of the Sauce Grande lagoon (Argentina. Samples were taken between March 2002 and December 2003. Ninety-six samples from three sampling stations were analyzed in order to determine the density of aerobic heterotrophic microorganisms, the presence of sulphite-reducing clostridia, and the most probable number of total coliforms, E. coli, fecal enterococci and P. aeruginosa. The water pH, temperature and chemical composition (N-NO3-, PO4³-, Na+, Ca++ +Mg++, EC and SAR were also determined. Statistical analysis shows an increase in the microbial parameters of fecal pollution and in the population of heterotrophic microorganisms during the warmest months, influenced by higher temperatures and the more intensive recreational use. Bacterial count indicated that fecal pollution was statistically lower at the recreational area monitoring station; however, P. aeruginosa, an opportunistic pathogen, was present in higher than permitted densities in all determinations. These results show that, from the physico-chemical point of view, anthropogenic activities do not significantly affect the quality of the resource.En el presente trabajo se evaluó la calidad bacteriológica y química en aguas de la laguna Sauce Grande (Argentina. Los muestreos fueron realizados entre marzo de 2002 y diciembre de 2003. Se analizaron un total de 96 muestras provenientes de tres estaciones de monitoreo, determinando: densidad de microorganismos heterótrofos mesófilos, presencia de clostridios sulfito-reductores y número más probable de coliformes totales, Escherichia coli, enterococos fecales y Pseudomonas aeruginosa. También se efectuaron determinaciones de pH, temperatura del agua y composición química (N-NO3-, PO4(3-, Na+, Ca++ + Mg++, CE y RAS. Se observó que en los meses más cálidos se produjo un aumento en los parámetros microbianos indicadores de contaminación fecal y en

  3. Microscale adaptation of the potentiometric method with ion-selective electrode for the quantification of fluoride; Adaptacion a microescala del metodo potenciometrico con electrodo ion selectivo para la cuantificacion de fluoruro

    Energy Technology Data Exchange (ETDEWEB)

    Guevara Ruiz, Paulina; Ortiz Perez, Maria Deogracias [Laboratorio de Bioquimica, Facultad de de Medicina, Universidad Autonoma de San Luis Potosi, San Luis Potosi, San Luis Potosi, (Mexico)]. E-mail: mdortiz@uaslp.mx

    2009-05-15

    Similarly to other countries, ground water from Mexico is naturally polluted by fluoride. The main effects of fluoride at typical ground water concentrations are dental fluorosis, neurological deficits and reproductive disorders. In order to verify that the fluoride concentration is within the allowed guideline in Mexico (NOM 127 and 201), it is important to monitor fluoride levels in water and commercial beverages. The aim of this work is to develop a modification of the standard potentiometric method for fluoride determination in water, in order to reduce costs and amount of potentially toxic waste substances. Both methods were validated, the standard potentiometric method with the ion selective electrode and the microscale modification proposed in this paper. The methods were compared using statistic tests and graphics, followed by the comparison of 125 samples of commercial bottled water sold in the city of San Luis Potosi. Optimal results were obtained for the validation of both methods, and the microscale modification showed statistically identical results to those obtained with the standard method in all samples of bottled water. The microscale modification is a good alternative for fluoride assessment in water and beverages, and it represents a 95 % reduction of costs and chemical waste. [Spanish] En varios paises, incluido Mexico se presenta una contaminacion natural con fluoruro en agua subterranea; los principales efectos en la salud observados en poblacion expuesta a concentraciones mayores al valor permisible (que en Mexico es de 1.5 mg/L) son la fluorosis dental y esqueletica, asi como dano reproductivo y neurologico. En varios estados de la republica Mexicana, este problema es aun desconocido, de ahi la necesidad de evaluar las concentraciones de fluoruro en agua de consumo en varias comunidades. Asi, el objetivo de este trabajo es desarrollar un metodo a microescala para la determinacion de fluoruro en agua, que al reducir la cantidad de reactivo y

  4. Trayectorias laborales entre el empleo, el desempleo y las microunidades en México

    Directory of Open Access Journals (Sweden)

    Carlos Salas

    2003-01-01

    Full Text Available Los planteamientos teóricos sobre el desempleo que se utilizan comúnmente, en particular la segmentación rígida, no son válidos para México. Aquí se recurre al análisis de trayectorias laborales de la población laboral entre distintas actividades, sectores y unidades de distinto tamaño. Este análisis está asociado al uso de regresiones logit que relacionan el trabajo en los micronegocios con diversas características demográficas y económicas de la población laboral. Un resultado que surge de este análisis es la persistente permanencia de los trabajadores en microunidades. Es pertinente señalar que no se trata de demostrar empíricamente la validez de resultados alcanzados mediante el uso del análisis econométrico. Más bien se busca ejemplificar el funcionamiento dinámico y las múltiples determinaciones que tiene la actividad en los micronegocios. En las conclusiones hay una sección dedicada a los problemas metodológicos implícitos en el uso de las técnicas estadísticas para verificar la validez de una hipótesis.

  5. O conceito de gênero: uma leitura com basenos trabalhos do GT Sociologia da Educação da ANPEd (1999-2009

    Directory of Open Access Journals (Sweden)

    Marília Pinto de Carvalho

    2011-01-01

    Full Text Available Este artículo es resultado del trabajo encomendado por el GT de Sociología de la Educación, con el objetivo de impulsar el debate teórico sobre el concepto de género en el ámbito del grupo. Delante de la imposibilidad de hacer una discusión amplia de todas las vertientes y polémicas que envuelven el concepto, se decidió enfocarlo a partir de los autores más utilizados en los trabajos presentados en el GT en los últimos diez años: Scott, Bourdieu y Connell. Se cree que las cuestiones que son planteadas aquí reflejan algunas de las tensiones y problemas candentes en los estudios feministas, pudiendo contribuir para que estudiosos de la educación, mismo no tornándose especialistas, consideren también las determinaciones de género en sus estudios específicos.

  6. Mulheres para a Marinha do Brasil: recrutamento e seleção das primeiras oficiais enfermeiras (1980-1981

    Directory of Open Access Journals (Sweden)

    Ana Paula Carvalho Orichio

    2012-01-01

    Full Text Available Estudio histórico-social, cualitativo, cuyos objetivos fueron describir el proceso de selección de oficiales enfermeras para el Cuerpo Auxiliar Femenino de la Reserva de la Marina y analizar el proceso de incorporación del habitus militar por las enfermeras aprobadas en el concurso, durante el curso de formación. Se utilizaron documentos escritos y testimonios orales de cuatro enfermeras militares que han compuesto la primera turma. Los datos, recogidos en el período de enero hasta octubre de 2010, fueron organizados, clasificados y analizados conforme el método histórico y con base en los conceptos de habitus y campo de Bourdieu. Se evidenció que el proceso de formación de las primeras oficiales enfermeras de la Marina de Brasil contempló la rigorosa incorporación de determinaciones distintas y distintivas relativas al comportamiento requerido para una oficial militar, especialmente en lo que concierne a las interdicciones que reafirmaban el poder masculino. Se concluyó que la incorporación del habitus militar mediante el aprendizaje de símbolos y gestos militares demarcó la construcción de la identidad de la enfermera militar.

  7. Estimated losses of energy in a power system using a semi-statistical methodology; Estimacion de perdidas de energia en un sistema electrico de potencia mediante una metodologia semi-estadistica

    Energy Technology Data Exchange (ETDEWEB)

    Martinez Martinez, D [Centro Universitario UAEM, Valle de Teotihuacan (Mexico)]. E-mail: david_2mtz@hotmail.com; Martinez Lendech, J.F [Instituto Tecnologico de Estudios Superiores del Oriente del Estado de Hidalgo (Mexico)]. E-mail: mrtzlendech@hotmail.com; Garcia Herrera, C; Olvera Ricano, J.G. [Centro Universitario UAEM, Valle de Teotihuacan (Mexico)]. E-mails: cozobi_garcia@yahoo.com.mx; jgolverar@uaemex.mx

    2013-03-15

    Determination of electrical losses is one of the most important tasks for any enterprise dedicated to generation, transmission, transformation and/or distribution of electric energy. Any enterprise dedicated to these activities does continuously energy balances in order to estimate whole electrical losses of specific processes. However, it is necessary to classify the whole electrical losses into technical and non-technical losses. This paper presents a proposal for estimating technical and non-technical losses in an electrical power system. [Spanish] La determinacion de las perdidas de energia electrica es una de las labores mas importantes en cualquier empresa dedicada a la generacion, transmision, transformacion y/o distribucion de energia electrica. Es indudable que toda empresa dedicada a cualquiera de las actividades mencionadas anteriormente realiza periodicamente balances de energia que permiten estimar el valor de las perdidas totales de energia del proceso considerado. No obstante, para poder realizar un mejor analisis de la problematica de las perdidas de energia, es necesario separar el valor total de perdidas obtenido mediante un balance de energia, en perdidas tecnicas y perdidas no tecnicas. El presente trabajo presenta una propuesta para la estimacion de perdidas tecnicas y no tecnicas en un sistema electrico de potencia.

  8. A pesquisa sobre a organização da escolaridade em ciclos no Brasil (2000-2006: mapeamento e problematizações

    Directory of Open Access Journals (Sweden)

    Jefferson Mainardes

    2009-01-01

    Full Text Available Este artículo presenta un análisis de 123 tesis y disertaciones sobre la organización de la escolaridad en ciclos en Brasil escritas durante período que abarca del 2000 al 2006. Resulta en una tentantiva por realizar una revisión sistemática de las investigaciones sobre el tema con el objetivo de identificar las principales tendencias, contribuciones, lagunas y problemas con él relacionados. A partir del analisis de estos trabajos el artículo explora dos aspectos específicos: la relación macro y micro y la discusión sobre los fundamentos de la política (escuela en ciclos. El artículo indica que es necesario profundizar aspectos teóricos y metodológicos de la investigación sobre ciclos, considerar las determinaciones más amplias relacionadas a la política, como el sistema de mediaciones, de forma de buscar una comprensión del conjunto de las relaciones que se establecen con los demás fenómenos y con la totalidad.

  9. Trabajo social y campo posmoderno: critica de sus proposiciones en torno a la intervención profesional = Social work and postmodern field: critical of its proposals about professional intervention

    Directory of Open Access Journals (Sweden)

    Gianna, Sergio Daniel

    2015-01-01

    Full Text Available El trabajo que aquí se presente tiene por finalidad el análisis y crítica de una de las tendencias contemporáneas en el Trabajo Social argentino: el campo posmoderno. Para ello, resulta fundamental el estudio y análisis de las principales determinaciones que presenta el campo posmoderno en las ciencias sociales, en particular, sus consideraciones en torno a la modernidad, la transición a un nuevo estadio de la sociabilidad, de carácter posmoderno, y la función que ejerció y ejerce la ciencia en la actualidad. Esto, permite identificar las mediaciones existentes entre éstas proposiciones teóricas y la configuración de un campo posmoderno en el Trabajo Social y como se generan un conjunto de proposiciones teóricas, políticas y éticas en torno a la intervención profesional

  10. Development and fabrication process for ZnO based varistors for medium voltage arresters 13000 V to 34000 V; Desarrollo y produccion de varistores de ZnO dopados para media tension 13000 V a 34000 V

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez Rolon, B.; Ireta Moreno, F. [Facultad de Ingenieria Mecanica, Electrica y Electronica, Universidad de Guanajuato, Salamanca, Guanajuato (Mexico)]. E-mail: barbara@salamanca.ugto.mx; fireta@salamanca.ugto.mx

    2011-04-15

    The fabrication process for ZnO doped varistor blocks with Sb2O3/ Bi2O3 to medium tension of 13000 V to 34000 V, and was optimised in terms of a starting composition and firing temperatures with amounts for Sb2O3/ Bi2O3 ratios of 1.7 by dry pressing, and fired in the temperature 1150 degrees Celsius {+-}2 degrees Celsius. The microstructure characteristics were analysed across the surface of the varistor blocks in order to evaluate their microstructure homogeneity. Their current-voltage I-V and energy handling capabilities were also determined. Characteristics and electrical properties of the varistor blocks are discussed. [Spanish] El proceso de fabricacion para varistores de media tension de 13000 V a 34000 V de ZnO consistio en dopar con Sb2O3, Bi2O3 y optimizarlos en terminos de la composicion de inicio, con una relacion de Sb2O3/Bi2O3 de 1.7, y el uso de aditivos para ceramicas, la temperatura de sinterizado fue de 1150 grados centigrados {+-}2 grados centigrados. Se investigo la homogeneidad de la microestructura. Se determinaron las propiedades electricas mediante la determinacion de la grafica I-V. Las caracteristicas electricas son discutidas.

  11. LA FIESTA: UTOPÍA, HISTORIA Y DERECHO A LA VIDA

    Directory of Open Access Journals (Sweden)

    MAXIMILIANO SALINAS CAMPOS

    2011-10-01

    Full Text Available Este trabajo quiere ser una aproximación a una reflexión historiológica acerca de la fiesta. ¿Cómo introducir el tema de la fiesta como un sentido de la Historia? El mundo intelectual y material de Occidente, sobre todo a partir de sus determinaciones burguesas, lleva a una negación del tema. La historicidad occidental se autoconcibe desde las lógicas de la conquista, explotación y racionalización del mundo. Estas lógicas culminan con el derecho a la muerte de la Tierra. Una reflexión acerca de la fiesta tiene que revertir dichas lógicas para reencontrar el derecho a la vida de la Tierra. Aquí alcanza su sentido más radical la pregunta sobre el carácter histórico de la fiesta. La fiesta nos coloca en el horizonte del origen, la subsistencia y el destino de la vida sobre la Tierra. Todo esto debe ser visto en la perspectiva de la refiguración de la imagen de Dionisos, concebido como arquetipo de la vida indestructible.

  12. Methodology for calculating the tourist carrying capacity as a tool for environmental management and its implementation in five northern Colombian Caribbean beaches

    International Nuclear Information System (INIS)

    Botero, Camilo; Yuri, Hurtado; Gonzalez, Jose

    2008-01-01

    This paper presents a new methodology to calculate carrying capacity in tourist beaches, further than merely environmental issues. Moreover, it understands beaches as complex systems towards its sustainable development. Five beaches in the North Caribbean coast of Colombia were chosen and classified in four tourism beach sorts: intensive, conservation, shared and ethnic. The analysis was done with legal framework review, fieldwork and indicators design, within three components: environmental support, urban infrastructure and tourist services. A new model to calculate carrying capacity in tourist beaches was created, and later applied on the study beaches. Current conditions of the five beaches were highlighted, their tourist carrying capacity were calculated and more important actions in each component were recommended. The main conclusion foster to take in consideration natural conditions as a core factor in beach management, but including a holistic approach in making decision process. Also this paper showed the current conditions of Colombian beaches as a warning, giving recommendations in short and medium term. This document is result of the project Determinacion de un sistema de calificacion y certificacion de playas turisticas.

  13. O MITO DO “FATOR ANTRÓPICO” NO DISCURSO AMBIENTAL GEOGRÁFICO

    Directory of Open Access Journals (Sweden)

    Elias Lopes de Lima

    2015-01-01

    Full Text Available Este artículo presenta una evaluación crítica de la forma en que se abordan las cuestiones ambientales en la geografia cuando es guiado en el discurso de la intervención antrópica. Gran parte de los estudios geográficos sobre el cuadro natural y los problemas ambientales han sido incapaces de comprender el hombre en la producción del espacio geográfico sin subordinarlo la un punto de vista antinómico de la naturaleza, dentro de la cual él es sólo un de sus partes integrales entre otros, sin dejar espacio, por lo tanto, las determinaciones históricas y sociales relativo a la producción del espacio. Contribuye a esta idea errónea un discurso ecoló- gico ambiental lo cual reduce la dialéctica entre la sociedad y la naturaleza a un mero intervención humana en el cuadro natural, restringiendo todo el proceso histórico de la producción social de la naturaleza y del espacio geográfico a un “factor antrópico”.

  14. Observaciones acerca de la dosificación de cemento en morteros y hormigones fraguados

    Directory of Open Access Journals (Sweden)

    Calleja Carrete, J.

    1965-09-01

    Full Text Available Present methods to determine the proportioning of cements in conglomerates, and specifically cement (whether Portland or not in set mortars and concretes, have general limitations which in most practical cases have the disadvantage that they involve considerable errors. In given cases, which are usually unexpected, these errors may considerably increase, and render useless the inferences that could be drawn therefrom. To avoid this it is necessary to supplement these methods with other means of determining the cement content. This will be especially so if the results could lead to serious economic consequences, or to evaluate responsibilities of any other type.Los métodos al uso para determinar la dosificación de conglomerantes en conglomerados, y más concretamente de cemento (portland o no en morteros y hormigones fraguados, tienen, en general, limitaciones que les hacen adolecer en la mayoría de los casos prácticos de errores considerables. En circunstancias determinadas, generalmente imprevistas, estos errores pueden aumentar notablemente e invalidar los resultados y las conclusiones que de los mismos pudieran extraerse. En evitación de ello es preciso entonces complementar los métodos con otras determinaciones, particularmente si el dictamen basado en el resultado hallado para la dosificación puede afectar seriamente a intereses económicos, o determinar una responsabilidad de cualquier tipo.

  15. Determinación volumétrica de la sílice en el cemento Portland

    Directory of Open Access Journals (Sweden)

    Calleja, J.

    1966-09-01

    Full Text Available Not availableSe describe un método volumétrico para la determinación cuantitativa de la sílice en el cemento portland, basado en la precipitación de la misma como fluorosilicato potásico, hidrólisis de esta sal insoluble en las condiciones de ensayo y valoración del ácido fluorhídrico liberado, con una disolución de hidróxido sódico. El método da valores reproducibles con muy escasa dispersión. La diferencia entre los valores más dispares de series de diez determinaciones hechas en una misma muestra por el mismo operador, son del orden de la tolerada por las normas A.S.T.M. (método gravimétrico para valores de un mismo operador obtenidos sobre una muestra. La diferencia entre cualesquiera otros dos valores de las series, o entre uno cualquiera de ellos y la media correspondiente a dicha serie, es muy inferior al margen de tolerancia de la A.S.T.M. Finalmente, entre el valor gravimétrico según el método de las normas A.S.T.M. y los valores volumétricos obtenidos por el método descrito, a la media de ellos, existe una concordancia aceptable.

  16. Pequeñas lecciones (provisionales respecto de la formación para la investigación educativa y social

    Directory of Open Access Journals (Sweden)

    Eduardo FERNÁNDEZ RODRÍGUEZ

    2011-01-01

    Full Text Available En este artículo se pretende dar una serie de localizaciones reflexivas acerca de la formación para la investigación educativa y social. Partiendo de un contexto actual, en el que la investigación se encuentra sometida a las necesidades y determinaciones del capitalismo académico, lo que se plantea aquí es una serie de interrogantes que, a modo de pequeñas lecciones, nos sirvan para volver a pensar lo que hacemos en la formación de investigadores sociales. Aparecen cuestiones relacionadas con: la geocultura del investigador-empresario, el desarrollo de un conocimiento basado en el paradigma de la Complejidad y los Estudios culturales, la incorporación del sujeto pos-positivista a la comprensión de los fenómenos sociales, la relación de la investigación social con las teorías sobre la democracia, o la necesaria revisión de la Investigación Participativa. Estas cosas, y muchas otras, deben formar parte de un curso cero respecto del campo, tan variado y conflictivo, de la investigación social y educativa.

  17. El hierro en la roca zeolitizada del yacimiento de Palmarito de Cauto: separación y caracterización de fases magnéticas

    Directory of Open Access Journals (Sweden)

    Daria Tito-Ferro

    2011-03-01

    Full Text Available Se presenta un estudio sobre la roca zeolitizada del yacimiento de Palmarito de Cauto, constituida fundamentalmente por zeolita del tipo mordenita, con el objetivo de identificar las principales fases magnéticas y otras fases asociadas al hierro y recomendar métodos para su eliminación. Para el estudio, diferentes clases de tamaño de partícula (-0,09+0,05; -0,05+0,038 y -0,038+0 mm de zeolita fueron sometidas a separación gravimétrica y magnética para concentrar fases no zeolíticas asociadas al hierro. Antes y después de cada separación, las muestras fueron sometidas a determinaciones de contenido de hierro, mediciones de susceptibilidad magnética y análisis por difracción de rayos-X. Se identificó a magnetita como principal fase magnética (ferromagnética asociada al hierro en la roca zeolitizada de Palmarito de Cauto. Además se demostró que mediante el uso de métodos gravimétricos y magnéticos pueden ser separadas y eliminadas las fases no zeolíticas asociadas al hierro en estas zeolitas naturales. Las mayores cantidades de hierro separadas se lograron

  18. Hybrid 95: Software for the design of hybrid systems, Potrerillo of Santa Teresa; Hybrid 95: Software de diseno de sistemas hibridos, Potrerillo de Santa Teresa

    Energy Technology Data Exchange (ETDEWEB)

    Casaravilla, G.; Chaer, R. [Instituto de Ingenieria Electrica, Facultad de Ingenieria, Universidad de la Republica, Montevideo (Uruguay)

    1997-12-31

    This paper describes the software Hybrid 95 and how it is used for the design of hybrid systems. As an application example some of the design stages are looked over (determination of the wind resource, simulations for sizing generation/storage and topology) of the Potrerillo installation. Taking into account the site clear ecological connotations, during the design consideration is made of the visual impact that represents the possible wind-generator, therefore several locations and wind-generator heights are studied, even arriving to the wind-generation elimination. [Espanol] Este trabajo describe el software Hybrid 95 y como se utiliza a los efectos del diseno de sistemas hibridos. Como ejemplo de aplicacion se recorren algunas de las etapas del diseno (determinacion del recurso eolico, simulaciones para el dimensionado de generacion/acumulacion y topologia) de la instalacion de Potrerillo. Teniendo en cuenta las claras connotaciones ecologistas del lugar, durante el diseno se tiene presente el impacto visual que representa el eventual aerogenerador por lo que se estudian diversas ubicaciones y alturas de aerogenerador, llegandose incluso a estudiar la eliminacion de la generacion eolica.

  19. Normas de calidad para las variedades de mango "tommy Atkins" y "común" (hilacha

    Directory of Open Access Journals (Sweden)

    Gabriela Mahecha

    2010-05-01

    Full Text Available Se caracterizaron dos variedades Je mango (Manauifera indica L; Tommy Atkins y Común.Se realizaron las siguientes determinaciones; a físicas; forma, volumen, dureza, peso total, rendimiento en pulpa y relación longitud/diámetro y b químicos: % de acidez titulable, y de almidón, °Brix, pH, índice de madurez y análisis sensorial,Se ensayó un método cualitativoparadeterminaralmidon.se desarrollaron cartas de color tanto de la cascara como de la pulpa, del estado verde al maduro y se diseñó un dispositivo para medir en forma ágil la longitud y los diámetros de la fruta. En las dos variedades se encontraron correlaciones altamente significativas entre la longitud y los diámetros mayor y menor, la longitud y el peso total, la dureza sin cascara y el índice de madurez, el peso específico aparente y el % de almidón y entre el contenido de almidón y el índice de madurez. En base a los resultados obtenidos se establecieron estándares preliminares de calidad para selección de mango durante la recolección, comercialización y mercadeo

  20. El factor laboral en la crisis y cambio organizativo de cinco empresas industriales en los 80s

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    Edgar Augusto Valero

    1996-05-01

    Full Text Available RESUMEN A partir de información variada de un grupo de cinco empresas industriales de diferentes ramas, que tienen en común su significación como establecimientos antiguos, de gran tamaño e importancia  a nivel nacional, se construye el proceso en que surge y se estabiliza  un esquema de organización de la producción y manejo laboral que por varias décadas predomino en un importante sector de empresas colombianas. La incidencia de factores externos a las firmas como la política económica y la situación de mercado, e internos como las determinaciones sobre la organización del tipo tecnología, mano de obra disponible  y cierto paternalismo empresarial, dan forma a un tipo de gestión de la fuerza laboral muy orientado por principios que se han definido como tradicionales, paternalistas  o de empresa providencia. Como veremos, en tres de las empresas estudiadas los elementos tradicionales no se expresan solo en la relación empresarios- trabajadores, si no que transcienden a los vínculos entre empresarios y comunidades; en estos casos se originaron no solo islotes de estabilidad laboral, sino también estructuras de apoyo a las zonas geográficas en que operaban las grandes empresas.

  1. Víctimas del arte: Reflexiones en torno a la representación de la guerra en Colombia

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    Alejandro Gamboa

    2016-04-01

    Full Text Available Pocos temas son tan delicados y problemáticos de representar como el de la memoria de la guerra: cúmulos de testimonios, imágenes y relatos presentan al artista-investigador un reto formal, epistémico y ético. Usando como ejemplo la instalación titulada Sudarios, realizada por la artista colombiana Erika Diettes (Cali, 1978, este artículo reflexiona sobre el actual “boom” de prácticas artísticas que representan la guerra en Colombia. Se argumentará que las lógicas del “repudio a la guerra” y el “homenaje a las víctimas”, vehiculadas acríticamente por algunas obras de arte, pueden estar re-produciendo formas de subjetividad en la que toda identidad es aplanada, donde la historia es suspendida y los conflictos pospuestos. Así, suprimir la complejidad del fenómeno de la guerra (con sus determinaciones económicas, políticas, históricas, ideológicas, entre otros estaría propiciando el despliegue de sentimientos morales que pueden ser absorbidos por el poder hegemónico.

  2. Comportamiento de las fracciones activas del fósforo inorgánico en los vertisoles crómicos de Holguín.

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    Yakelin Cobo-Vidal

    2013-07-01

    Full Text Available La investigación se realizó con la información de 40 perfiles de suelo de un vertisol crómico, en áreas cultivadas con caña de azúcar de la Empresa Azucarera Holguín. Se tomaron las determinaciones analíticas correspondientes a las fracciones activas del fósforo inorgánico (P-Ca, P-Fe, P-Al, P-total y el fósforo asimilable por el método de Oniani, a las profundidades 0-25, 25-50, 50-75 y 75-100 cm. Los resultados mostraron un bajo nivel del P- total con una progresiva disminución de la profundidad del perfil, P-Ca es la fracción dominante en estos suelos, lo que indica un bajo nivel de meteorización del perfil, P-Fe y P-Al a diferencia de P-Ca disminuyen con la profundidad. La relación de las fracciones activas con el pH, demostró que P-Ca aumenta, a medida que lo hace el pH, una relación inversa mostró el fósforo ligado a las fracciones (P-Fe y P-Al.

  3. Osteoporosis secundaria. tratamiento actualizado

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    G. Sofía Oviedo, Dra.

    2013-09-01

    Full Text Available La osteoporosis se caracteriza por alteración de la microarquitectura del hueso con disminución de la resistencia lo que predispone a fracturas, siendo éstas la complicación más grave por su alta morbimortalidad. Es una patología prevalente, pero subdiagnosticada con muerte asociada a complicaciones que son más frecuentes que otras patologías como el cáncer de mama. La osteoporosis secundaria se manifiesta con fracturas por fragilidad y se presenta en mujeres premenopáusicas, hombres adultos jóvenes y en el 30% de las mujeres postmenopáusicas. Una anamnesis y examen físico acucioso así como determinaciones de laboratorio, densitometría ósea y radiología de columna son fundamentales para el conocimiento de su causa, ya sea endocrina, hematológica, gastroenterológica o medicamentos entre otras. El tratamiento de la patología de base asociado a terapia específica para osteoporosis comprende cambios en el estilo de vida, aporte de calcio y vitamina D, bifosfonatos, teriparatide y denosumab los que se indican de acuerdo a la causa y magnitud del compromiso.

  4. USO DE BIOPREPARADOS EN EL COMPOSTAJE DE RESIDUOS ORGÁNICOS URBANOS

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    Einstein Churchill Aveiga Villacis

    2016-12-01

    Full Text Available El trabajo tuvo como objetivo evaluar la aplicación de biopreparados microbianos como aceleradores del proceso de compostaje de residuos orgánicos generados en la Universidad Laica Eloy Alfaro de Manabí. En el proceso se emplearon cajoneras de madera que contenian 170 kg de material inicial, el cual fue inoculado con los aceleradores del proceso de compostaje, ensayando tres variantes: T1, testigo (sin inoculo; T2, EM comercial y T3, microorganismos nativos. El inóculo fue asperjado al inicio del proceso de compostaje que duró ocho semanas, en este lapso se monitoreó pH, humedad y temperatura. Al final del proceso se tomó una muestra compuesta de cada tratamiento y se realizaron determinaciones físico-químicas y pruebas de fitotoxicidad empleando semillas de caupi (Vigna unguiculata. Los resultados determinaron que la temperatura, pH y humedad no variaron significativamente; sin embargo, los indicadores de estabilidad y madurez del compost (C/N, MO, N, P, microelementos y porcentaje de germinación de semillas de caupi fueron favorables en el compost que había sido inoculado con microorganismos nativos, alcanzando valores óptimos, según la norma técnica colombiana 5167. Los resultados demuestran que los inóculos son eficientes en el proceso de compostaje y que el compost obtenido puede ser utilizado con fines agrícolas.

  5. Pubertad precoz y tumoración torácica: presentación de un caso

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    María Nataly Laredo Reyna

    Full Text Available Se reporta el caso de un paciente de 7 años de edad, que inicia su enfermedad con disnea progresiva, el desarrollo genital, de acuerdo con los criterios de Marshall y Tanner, muestra un estadio G2 VP3. En el tórax se halló una tumoración de bordes regulares y definidos, con presencia de calcificaciones y áreas quísticas de contenido heterogéneo. Las determinaciones basales de FSH, LH y testosterona fueron de < 10 mUI/mL, 12,2 mUI/mL y 724 ng/dL, respectivamente. La determinación de la α-feto proteína fue de 145,1 ng/mL. La exéresis del tumor mejoró el cuadro respiratorio, la remisión de los niveles hormonales y la detención del proceso de pubertad precoz. El estudio anatomopatológico de la tumoración mediastinal correspondió a un tumor de células germinales con componente predominante de teratoma maduro y coriocarcinoma. La pubertad precoz de etiología neoplásica es una causa rara, su diagnóstico es primordial para aplicar un tratamiento oportuno.

  6. Method to estimate the convective mixing height from atmospheric sounding data; Un metodo para estimar la altura de la capa de mezcla a partir de datos de radiosondeo atmosferico

    Energy Technology Data Exchange (ETDEWEB)

    Salcido, Alejandro [Instituto de Investigaciones Electricas, Temixco, Morelos (Mexico); Castro, Telma [Universidad Nacional Autonoma de Mexico, Mexico, D.F. (Mexico)

    2000-07-01

    A simple method to estimate the convective mixing height from atmospheric sounding data is presented in this paper. The proposed method is based on the slab model of the atmospheric boundary layer, which assumes that virtual potential temperature remains constant in the mixed layer, increases linearly with height in the free atmosphere, and has a discontinuity at the entrainment layer (in fact, the entrainment layer is assumed to be infinitesimal in depth). The proposed method was applied in Mexico City in order to estimate the mixing height values for 5:00 and 17:00 hours (local time) from January to May of 1993 and 1994. [Spanish] En este trabajo se presenta un metodo para estimar la altura de la capa de mezcla a partir de los datos de radiosondeo atmosferico. El metodo esta basado en un modelo de la capa limite atmosferica donde la temperatura potencial virtual se mantiene constante en la capa de mezclado, sufre una discontinuidad en la zona de entrainment (el espesor de la cual se supone infinitesimal), y crece linealmente con la altura en la atmosfera libre. El metodo desarrollado se utilizo para la determinacion de la altura de la capa de mezcla de la Ciudad de Mexico para las 11:00z y 23:00z de los dias de los meses de enero a mayo de los anos de 1993 y 1994.

  7. Modelo matemático para la descripción de la transferencia de calor para tierra vertida

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    Edgardo Jonathan Suárez-Domínguez

    2014-01-01

    Full Text Available La arquitectura de tierra implica procesos constructivos sustentables ya que utiliza materiales vernáculos duraderos cuyos residuos son de bajo impacto al ambiente. La tierra vertida es una técnica a partir de la cual pueden tenerse muros resistentes dentro de la edificación de viviendas pero cuyas propiedades han sido poco evaluadas y representadas a partir de modelos. La transferencia de calor es una de las características más importantes cuando se edifica en zonas calurosas pues implica ciertos niveles de confort para los usuarios. El presente trabajo propone un modelo para determinar la difusividad térmica de tierra vertida con uso potencial para otras determinaciones a diversas temperaturas, algunas implicaciones también son presentadas. Se encontró que el coeficiente de difusividad térmica de muestras de tierra vertida fue de   4.319  10 8 m 2 s 1 , mientras que su calor específico es de 1.1030 kJkg-1K 1 .

  8. Algunas variables bioquímicas en adolescentes obesos con antecedente de bajo peso al nacer

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    María del Carmen Valdés Alonso

    Full Text Available Introducción: la malnutrición intraútero ha sido postulada con vinculación a afecciones del desarrollo embrionario que determinan el desarrollo ulterior de obesidad, diabetes mellitus tipo 2, dislipidemias, disfunción mitocondrial y aterosclerosis. Objetivo: determinar las complicaciones metabólicas en adolescentes obesos con antecedentes de bajo peso al nacer. Métodos: estudio descriptivo y de corte transversal. Se incluyeron 50 pacientes obesos, con antecedentes de bajo peso al nacer y embarazo a término, de ambos sexos, en las edades comprendidas entre 9 y 17 años de edad, que asistieron a la consulta externa del servicio de Endocrinología del Hospital Pediátrico Docente "Juan Manuel Márquez", en el período comprendido de enero de 2011 a enero de 2012. Se realizaron determinaciones de colesterol, triglicéridos, aminotransferasas hepáticas, glucemia, e insulinemia en ayunas y posprandial de dos horas. Resultados: las variables bioquímicas estudiadas no mostraron diferencias entre los puntos de corte utilizados para clasificar el peso al nacer. La transaminasa glutámico pirúvica mostró valores más altos en los adolescentes entre 15 y 17 años de edad. Conclusiones: la hipertrigliceridemia fue más elevada en el sexo femenino, mientras que la hiperglucemia y la hiperinsulinemia lo fueron en el masculino.

  9. Indicadores de calidad de las harinas de trigo: índice de calidad industrial y su relación con ensayos predictivos

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    A.E. de la Horra

    2012-12-01

    Full Text Available El objetivo de este trabajo fue estudiar y evaluar la capacidad de diferentes parámetros para predecir la calidad de las harinas de trigo, analizando las relaciones existentes entre éstos y el índice de calidad industrial (ICI. Se utilizaron siete muestras de harina de trigo provistas por la CEI Barrow. Se determinaron parámetros relacionados con la calidad del grano de trigo, la molienda y la composición de las harinas. Además, se llevaron a cabo ensayos relacionados con el comportamiento de las masas (ensayo farinográfico y alveográfico y se elaboró pan. Se calculó el ICI para cada una de las muestras y se estudió su relación con pruebas de predicción y ensayos de calidad. El ICI mostró correlaciones significativas y positivas con el contenido de macropolímero de glutenina, la extensibilidad alveográfica y el tiempo de desarrollo de la masa. Estas relaciones podrían resultar beneficiosas en la evaluación de la aptitud de las harinas para la elaboración de diferentes productos panificados, ya que constituyen determinaciones más sencillas y no requieren de equipamiento de alta tecnología ni grandes cantidades de muestra.

  10. Azar, libertad y responsabilidad: aportes para una práctica psicológica

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    Horacio Manrique Tisnés

    2013-01-01

    Full Text Available Este artículo propone una mirada sobre la responsabilidad partiendo de los conceptos de azar y libertad, los cuales se consideran básicos para sostener que el sujeto tiene la pos ibilidad de elegir, a pesar de sus determinaciones. En este sentido, lo azaroso, entendido como el comportamient o impredecible de ciertos eventos, dada su falta de regularidad, se interrelaciona con aspectos determinados y otros aleatorios. Por su parte, la libertad es posibilidad de elegir. La responsabilidad, entendid a como una consecuencia del azar, y la libertad se define como “la respuesta acorde con el propio ser” (Ramírez, 2 012, p. 45. Con base en lo anterior, la psicología, en cualquiera de sus campos, puede generar efectos d e responsabilización en el sujeto, por sí mismo y por el entorno, teniendo en cuenta las respuest as que puede dar un ser humano en una situación elemental, primaria o secundaria. Dentro de este contexto, cabe resaltar l a respuesta secundaria que puede ofrecer una persona, en la medida en que ésta caracteriza su responsabilidad ét ica, la cual puede ser promovida por la práctica psicológica basada en una actitud analítica.

  11. ESTUDIO POR ESPECTROFOTOMETRIA UV-VIS DE LA REACCIÓN ENTRE LOS IONES CIANURO Y EL PICRATO. UN EJEMPLO PRÁCTICO DE APLICACIONES ANALITICAS Y ESTUDIOS CINÉTICOS

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    Alberto de J Oliveros-Bastidas

    2009-06-01

    Full Text Available  La cinética de la reacción entre el ión cianuro y el picrato de sodio se estudió por espectrofotometría UV-Vis. Se observó una reacción de orden uno para ambos reactivos, así como un desplazamiento batocrómico de la señal de máxima absorbancia, incrementando la concentración de cualquiera de los reactivos, asociada a la formación de complejos de diferente estequiometría y resultando en los consiguientes cambios en los parámetros espectrométricos. Estos resultados sustentan una interacción de tipo p para el complejo resultante, resultado que se pudo generalizar utilizando otras moléculas donadoras que muestran las posibles interferencias de algunos compuestos químicos en las determinaciones cualitativas y cuantitativas de la frecuencia cianogénica y la determinación cuantitativa de glucósidos cianogénicos en plantas.

  12. Hipotiroidismo congénito secundario a hipoplasia tiroidea detectado en edad adulta

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    Paula Monti

    2013-04-01

    Full Text Available La ubicación anatómica de la glándula tiroidea y su biosíntesis hormonal están reguladas por la expresión de ciertos genes, cuya alteración puede conducir a las denominadas disgenesias tiroideas: agenesia, ectopía e hipoplasia, así como a las variantes dishormonogenéticas. Se presenta el caso de una paciente con retraso mental y diagnóstico de hipotiroidismo realizado en la edad adulta. Las determinaciones bioquímicas confirmaron el diagnóstico de hipotiroidismo no autoinmune. Este caso representa la evolución prolongada de una hipofunción tiroidea, que cursó en forma solapada y no diagnosticada durante 53 años de vida, con secuelas relevantes de esta deficiencia al momento del diagnóstico. La terapia exógena logró mejorías evidentes en la signo sintomatología, pero no revirtió el presunto daño neurológico atribuible a la falta de hormona tiroidea necesaria durante el desarrollo fetal. En la necropsia realizada se encontró escaso tejido tiroideo cervical correspondiente a hipoplasia tiroidea eutópica. El hallazgo de un remanente tiroideo menor a 1 cm permite explicar la supervivencia de la paciente hasta una edad avanzada.

  13. Thermal analysis for energy consumption reduction in cooling water systems; Analisis termico para la reduccion del consumo de energia en sistemas de agua de enfriamiento

    Energy Technology Data Exchange (ETDEWEB)

    Picon Nunez, Martin [Instituto de Investigaciones Cientificas, Universidad de Guanajuato, Guanajuato (Mexico); Quillares Vargas, Luis [Tecnopinch, S. A. de C. V., (Mexico)

    1998-12-31

    This paper presents the fundamental principles for the thermal analysis of cooling water systems in processing plants. In existing heat dissipating networks this methodology application allows the identification of opportunities for reducing the energy consumption used for cooling water pumping. The methodology is based on the determination of the minimum cooling water flow as a function of the installed heat exchange capacity, subjected to the restrictions of the maximum allowed temperature elevation. The methodology application to real systems, has resulted in saving 20% of the total energy consumed in cooling water pumping. [Espanol] En este trabajo se presentan los principios fundamentales para el analisis termico de sistemas de enfriamiento en plantas de proceso. En redes de eliminacion de calor existentes, la aplicacion de esta metodologia permite identificar oportunidades para reducir el consumo de energia utilizada para el bombeo del fluido enfriante. La metodologia se basa en la determinacion del flujo minimo de agua de enfriamiento en funcion de la capacidad de transferencia de calor instalada, sujeta a las restricciones de maximo incremento de temperatura permitido. La aplicacion de la metodologia a sistemas reales, ha resultado en ahorros del 20% del total de la energia que se consume en el bombeo del agua de enfriamiento.

  14. Pensar la historia del pensamiento

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    Jimmy Washburn Calvo

    2012-11-01

    Full Text Available Se aborda la pertinencia de estudiar la historia de la filosofía en la enseñanza superior, como medio para inducir la enseñanza de la propia filosofía. La premisa es que todo ejercicio filosófico tiene lugar en un contexto histórico y cultural, y pesan sobre aquel las determinaciones de ese contexto, de manera que la investigación debe considerar el espacio y las condiciones en que se ha procurado producir conocimiento filosófico y se han acuñado particulares teorías y conceptos. En la consideración del contexto histórico de producción de la filosofía hallaremos elementos que nos permitirán hallar analogías entre las sociedades que produjeron esos marcos teórico-filosóficos y nuestras propias sociedades centroamericanas, que pueden afrontar, como aquellas, condiciones semejantes.

  15. COMPARACIÓN ENTRE ELECTRODOS POSAI Y ELECTRODOS COMERCIALES EN LA TITULACIÓN POTENCIOMÉTRICA DE SULFAMETOXAZOL Y TRIMETOPRIMA

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    Graciela Romero

    2012-01-01

    Full Text Available En este trabajo se compararon los electrodos POSAI (Película de Óxido Sobre Acero Inoxidable con los electrodos comerciales en la determinación potenciométrica de las sustancias activas sulfametoxazol y trimetoprima presentes en el medicamento Bactrim. La determinación de trimetoprima se llevó a cabo a través de la reacción ácido-base en medio no acuoso empleando ácido perclórico como solución titulante, mientras que en la valoración de sulfametoxazol se empleó nitrito de sodio para efectuar una reacción de óxido-reducción. El uso de los electrodos prototipo platino/POSAI para la reacción de óxido-reducción y el electrodo prototipo POSAI como electrodo de referencia en la reacción ácido-base presentaron un funcionamiento equiparable con el electrodo de platino/Ag/AgCl y el electrodo de vidrio comercial al detectar los mismos volúmenes de solución titulante en el punto de equivalencia bajo las condiciones de estudio en las determinaciones que se efectuaron a microescala.

  16. OBTENCIÓN Y CARACTERIZACIÓN DE CARBÓN ACTIVADO A PARTIR DE RESIDUOS OLIVÍCOLAS Y OLEÍCOLAS POR ACTIVACION FÍSICA

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    Ana J. Filippín

    2017-01-01

    Full Text Available En este trabajo se evaluó la potencial aplicación de biomasa de olivo en la elaboración de carbón activado. Las materias primas empleadas fueron hueso de aceituna extraído del alperujo y madera de poda del olivar, cuya caracterización se llevó a cabo en base a ensayos preliminares y a su contenido en lignina, celulosa y hemicelulosa. La obtención de los carbones activados (c.a. se realizó en dos etapas, carbonización y activación. La carbonización se llevó a cabo en atmósfera inerte a 600 °C y el proceso de activación consistió en una pirolisis a diferentes temperaturas (desde 280 °C a 900 °C con dióxido de carbono o aire como activantes. Se caracterizaron los c.a. mediante determinaciones de rendimiento en base seca (YC, Microscopia de Barrido Electrónico (MEB, Microsonda Electrónica (EDS, Área Superficial Especifica (BET y determinación de índice de yodo. Los carbones activados de mejor calidad se lograron por activación con dióxido de carbono.

  17. Derecho positivo y derecho natural: una reflexión desde el iusnaturalismo sobre la necesidad y naturaleza de la determinación

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    Sebastián Contreras

    2013-06-01

    Full Text Available El presente trabajo intenta analizar la naturaleza de la derivatio per modum determinationis. La filosofía escolástica enseña que la determinatio es uno de los modos de derivarse la ley humana desde la ley natural, particularmente el modo en que se deriva el derecho positivo o civil. En este trabajo el autor se detiene a revisar su modalidad, así como algunos criterios para reconocer las determinaciones o normas positivas.O presente trabalho procura analisar a natureza da derivatio per modum determinationis. A filosofia escolástica ensina que a determinatio é um dos modos por meio dos quais se deriva a lei humana a partir da lei natural, particularmente o modo no qual se deriva o direito positivo ou civil. Neste trabalho o autor se detém a revisar sua modalidade, bem como alguns critérios para reconhecer as determinações ou normas positivas.

  18. A numerical comparison between the spatially-growing and temporally-growing disturbance in a pipe

    Energy Technology Data Exchange (ETDEWEB)

    Pacheco, Rafael J. [Universidad de Guanajuato, Guanajuato (Mexico); Pacheco Vega, Arturo [University of Nortre Dame, IN (United States); Pacheco Vega, H. Raul [University of British Columbia, Vancouver (Canada)

    2001-08-01

    The linear stability of Poiseuille flow in a pipe is examined for the infinitesimal disturbances propagating in both, time and space. The numerical procedure for obtaining the eigenvalues of the linear problem and its adjoint is based on the spectral collocation method with shifted Chebyshev polynomials. The Fredholm alternative is then applied to determine the group velocity. We show that the temporal damping rates of axisymmetric infinitesimal perturbations are related to those in space by the group velocity in accord with the theory first developed by Gaster. [Spanish] Se examina la estabilidad lineal del flujo de Poiseuille en una tuberia para perturbaciones infinitesimales que se propagan en el tiempo y el espacio. El proceso numerico para obtener los valores caracteristicos del problema lineal y su adjunto se basa en el metodo espectral de colocacion con los polinomios de Chebyshev. La teoria de la alternativa de Fredholm se aplica a la determinacion de la velocidad de grupo. Se demuestra que las razones de decaimiento para las perturbaciones axisimetrias infinitesimales temporales estan relacionadas con las espaciales mediante la velocidad de grupo, de acuerdo con la teoria presentada por primera vez por Gaster.

  19. Hydrolysis and oxidation of covering oil in canned dried tomatoes as affected by pasteurization

    Directory of Open Access Journals (Sweden)

    Caponio, Francesco

    2005-09-01

    Full Text Available The effects of pasteurization on the chemical quality of the extra-virgin olive oil used as a covering for canned dried tomatoes were studied during storage through conventional (acidity, peroxide value, p-anisidine value, spectrophotometric indexes and non conventional (polar compounds analytical determinations. All the performed analyses show that extra-virgin olive oil from pasteurized samples underwent hydrolytic degradation slightly more than unheated ones but resulted slightly less oxidized than oil from untreated vessels.Los efectos de la pasterización sobre la calidad química del aceite de oliva virgen extra de cobertura en tomates desecados enlatados han sido estudiados durante su almacenamiento a través de determinaciones analíticas convencionales (acidez, índice peróxidos, índice de p-anisidina, índices espectrofotométricos y no convencionales (compuestos polares. Todos los análisis realizados muestran que el aceite de oliva virgen extra de las muestras pasterizadas sufre una degradación hidrolítica ligeramente mayor que el de las no tratadas pero resulta menos oxidado que el aceite de las muestras no tratadas.

  20. Mujeres, a caminar por nuestra salud

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    Natividad Pinto Afanador

    2004-01-01

    Full Text Available El artículo es una revisión de la autora, para mostrar a las mujeres la importancia de la actividad física introyectada en el diario vivir y más enfocada hacia el cambio comportamental al que se debe llegar, para tener, a través de ella, una actitud preventiva en contra o a favor de la salud. Parte de unos interrogantes que aún las mujeres se hacen, para tomar determinaciones de sus actitudes frente a la actividad física. Muestra resultados de estudios practicados en otros países del mundo, pero también reporta datos de investigaciones realizadas en el contexto. Además, incluye los beneficios físicos, psicológicos y emocionales que la actividad física puede aportar a todas las personas. El objetivo es mostrar, al género femenino, indicadores sólidos y comportamientos preventivos, que orienten a favor de la actividad física, con planteamientos acerca de las diferentes posibilidades para realizar la actividad física y sobre su importancia.

  1. Recomendaciones para la aplicación de algunos métodos analíticos incluidos en el reglamento CEE 2568/91 relativo a las características de los aceites de oliva y de orujo de oliva

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    León Camacho, M.

    1994-12-01

    Full Text Available Among the analytical methods officially adopted by the European Union to be applied to olive oils and olive pomace oils, some troubles have been found in the application of the procedures for the determination of sterols, trilinolein, trans isomers of fatty acids and waxes. The study of such difficulties suggests several modifications and recommendations facilitating the performance of methods and improving the reliability of results.

    Entre los métodos analíticos aceptados oficialmente por la Unión Europea para su aplicación a los aceites de oliva y los aceites de orujo de oliva, las determinaciones de esteroles, trilinoleína, isómeros trans de los ácidos grasos y ceras han mostrado algunas dificultades en su aplicación.
    El estudio de dichos problemas ha permitido establecer diversas modificaciones y recomendaciones que facilitan la práctica de los métodos y mejoran la fiabilidad de los resultados.

  2. Los espacios del consumo cultural colectivo

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    XAN BOUZADA FERNÁNDEZ

    2001-01-01

    Full Text Available El tratamiento de un asunto sociológico como el de los equipamientos culturales nos obliga a situarnos en un lugar encrucijada en el que se hilvanan temáticas tales como la sociología urbana, la sociología de la cultura o la sociología de la vida cotidiana. El abordaje de las causas de su génesis, así como el acercamiento al modo cómo se producen sus lógicas de implantación, nos lleva a cuestionar algunos de los supuestos hoy preponderantes que, a la manera de "prenociones", tienden a erigirse en explicación aparente de las políticas concretas y de las tomas de decisión en este ámbito. Determinados conceptos como el de "democratización cultural", inspirado en sus orígenes en el reformismo progresista de postguerra en Francia, podrían haber estado actuando como un mito que impidiese visualizar el hecho de que las políticas de producción de equipamientos culturales han tendido a homogeneizarse, independizándose de las determinaciones contextuales de caráctere político-ideológico, manteniendo una función estratégica como instrumentos al servicio de la reproducción de los poderes locales instalados.

  3. de riego 03, Valle de Mezquital, Hidalgo, México

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    F. Prieto-García

    2007-01-01

    Full Text Available En este trabajo se realiza el estudio de caracterización fisicoquímica y de extracciones secuenciales selectivas de metales trazas, tóxicos y no biodegradables y el metaloide arsénico, en suelos de la zona Actopan-Ixmiquilpan. La caracterización fisicoquímica se realizó mediante determinaciones de texturas de suelos, materia orgánica, pH, entre otros, para clasificar los suelos; paralelamente se realizaron evaluaciones de extracciones secuenciales selectivas de metales trazas (Pb, Cd, Cr y Hg y del metaloide As, siguiendo el esquema de Tessier et al. (1979, con el fin de correlacionar las características de estos suelos con los tiempos de irrigación, la cual se realiza con aguas negras desde hace más de 20 años (para esta zona. En general se encontró una correlación directa de los tiempos de irrigación con los contenidos de materia orgánica y una acumulación apreciable de Pb y Cr fundamentalmente, que puede acarrear problemas a más largo plazo por contaminación de cultivos.

  4. Prevalencia de factores de riesgo y riesgo cardiovascular global en la población de Tres Lomas

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    María E. Mazzei

    2008-01-01

    Full Text Available Resumen:La mortalidad atribuida a las enfermedades cardiovasculares se encuentra en primer lugar y en aumento en los países en vías de desarrollo. En la Argentina, las enfermedades cardiovasculares producen, junto con el cáncer, más del 50% de las muertes anuales. En contraposición a las enfermedades infecciosas, éstas se denominan genéricamente enfermedades no transmisibles y se ha demostrado que son prevenibles en gran medida a través del control y el manejo de los llamados factores de riesgo para el desarrollo de enfermedades cardiovasculares. Es por ello que la información sobre la prevalencia y la variación en el tiempo de estos factores de riesgo es fundamental para realizar una vigilancia epidemiológica del problema de las enfermedades cardiovasculares en la población y, a su vez, para proponer acciones comunitarias preventivas.ObjetivosObtener información sobre los factores de riesgo cardiovascular en la población de Tres Lomas (Buenos Aires, calcular el riesgo cardiovascular global (RCG y comparar estos resultados con los descriptos para toda la Argentina.Material y métodosSe entrevistaron al azar 522 adultos de Tres Lomas. Se utilizó el cuestionario para vigilancia epidemiológica de la OPS y se realizaron mediciones antropométricas. En 100 individuos se determinaron lípidos y glucemia para estimar el RCG, definido como probabilidad de desarrollar un evento no fatal o muerte coronaria en los próximos 10 años. Por último, estas prevalencias se compararon con las estimadas a nivel nacional.ResultadosHubo menor prevalencia de diabetes (7,7% versus 11,9%; p < 0,0001, tabaquismo (27,7% versus 33,4%; p < 0,0054 y depresión (14,4% versus 22,8%; p < 0,0001, aunque más sobrepeso y obesidad que el promedio país (58,4% versus 49,1%; p < 0,0001. Aunque la medición de la tensión arterial fue más frecuente que el promedio (82,2% versus 68,4%; p < 0,0001, las determinaciones de glucemia (50,2% versus 69,3%; p < 0,0001 y de

  5. Efecto de la suplementación con Vimang® sobre indicadores de estrés oxidativo en jóvenes con diabetes mellitus tipo 1 Effect of Vimang® supplementation on oxidative stress markers in young patients with type 1 diabetes mellitus

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    Adrián Luis Escobar Aedo

    2011-08-01

    Full Text Available Introducción: el estrés oxidativo juega un papel fundamental en la fisiopatogenia de las complicaciones de la diabetes mellitus. Se ha empleado con éxito el producto natural antioxidante Vimang® en enfermedades caracterizadas por incremento del estrés oxidativo. Objetivo: evaluar el efecto del Vimang® sobre el estado redox, en personas jóvenes con diabetes mellitus tipo 1. Métodos: se realizó un ensayo clínico fase II, unicéntrico, aleatorizado y controlado, en el que se evaluó la eficacia antioxidante del Vimang® en tabletas, en jóvenes con diabetes mellitus tipo 1. Fueron incluidos 50 pacientes, que se distribuyeron en 2 grupos de 25 cada uno, que recibieron Vimang® en tabletas de 300 mg cada 8 h y placebo, respectivamente. Se evaluó el control glucémico a través de la hemoglobina glucosilada, se realizó un lipidograma completo y determinaciones hemoquímicas. Fueron evaluadas las variables de daño por estrés oxidativo: potencial de peroxidación, hidroperóxidos totales, productos avanzados de la oxidación de proteínas, malonilaldehído y del antioxidante endógeno glutatión reducido. Las determinaciones se realizaron antes, y a los 3 meses de la intervención. Los grupos fueron comparados entre sí, en los dos tiempos, así como internamente con respecto al estado basal previo a la suplementación con Vimang® o placebo. Resultados: el potencial de peroxidación se incrementó a los 3 meses en ambos grupos (pIntroduction: the oxidative stress plays a fundamental role in the pathogenesis of diabetes mellitus complications. Vimang® (a natural antioxidant product has been successfully used diseases characterized by an increase of oxidative stress. Objective: to assess the effect of Vimang® on the redox state in young people presenting with type 1 diabetes mellitus. Methods: a phase II clinical, randomized, controlled unicenter trial to assess the antioxidant effectiveness tablets Vimang® in young people with type 1

  6. Estado redox en pacientes infectados por VIH/sida con insuficiencia renal crónica sometidos a hemodiálisis The redox state of VIH/AIDS patients suffering chronic renal failure and undergoing hemodyalisis

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    Olga Castaño Araujo

    2012-12-01

    Full Text Available Introducción: el balance redox alterado en el curso de la insuficiencia renal crónica ha sido considerado un factor contribuyente a la morbilidad y mortalidad de la enfermedad y un factor asociado a la progresión de la infección por sida. Objetivo: valorar el estado redox en pacientes infectados por VIH con insuficiencia renal crónica que requirieron hemodiálisis. Métodos: se realizó un estudio de casos y controles en 20 pacientes VIH/sida con insuficiencia renal crónica y 40 individuos aparentemente sanos. Se realizaron determinaciones de malonildialdehído, glutatión, superóxido dismutasa, catalasa, productos avanzados de la oxidación de proteínas, hidroperóxidos y potencial de peroxidación, conjuntamente con los marcadores de progresión: conteo de linfocitos T CD4+ y carga viral y una serie de determinaciones hemoquímicas y hematológicas. El análisis se realizó antes, a los 30 min y a los 240 min del tratamiento dialítico. Estadísticamente se verificaron los supuestos de igualdad de varianza y normalidad de las variables, y en dependencia se aplicó una prueba paramétrica o no paramétrica. El resultado fue significativo para pIntroduction: the altered redox balance in chronic renal failure has been considered a contributing factor to morbidity and mortality from this disease and as an AIDS progression-associated factor. Objective: to assess the redox state in HIV patients suffering chronic renal failure that requires haemodialysis. Methods: a case-control study was conducted in 20 HIV/AIDS patients with chronic renal failure and in 40 apparently healthy individuals. Estimations of malonildialdehyde, gluthatione, superoxide dismutase, catalase, advanced products from protein oxidation, hydroperoxides and peroxidation potentials, as well as progression markers such as T CD4+ lymphocyte count, viral load and a series of hemochemical and hematological determinations were all made. The analysis was made before, 30 minutes

  7. Melting properties of some structured lipids native to high stearic acid soybean oil

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    Dunn, R. O.

    2004-06-01

    Full Text Available A number of structured lipids native to high stearic acid soybean oil were synthesized and their physical properties were determined by pulsed nuclear magnetic resonance (NMR, Mettler dropping point and differential scanning calorimetry (DSC. 1,3 Distearo-2-olein (SOS, 1,3 distearo-2-linolein (SLS and1,3 distearo-2-linolenin (SlnS were synthesized from pure 1,3 diacylglycerols and the appropriate fatty acid. Pulsed NMR determinations over the temperature range 10-50 ºC showed that the symmetrical triacylglycerols (SUS: where S = stearic, U = oleic, linoleic or linolenic are high and sharply melting materials, all showing substantial amounts of solids at temperatures up to 33.3 ºC, yet are completely melted at only a few degrees higher. Mettler dropping points for SOS, SLS and SlnS were 44.1, 37.9 and 36.5 ºC respectively. The heats of fusion for the structured triacylglycerols were determined by DSC and shown to be of the order 29-32 cal/gm compared to 45 cal/gm for SSS. The heats of fusion were also calculated from Mettler dropping point determinations as admixtures with soybean oil and showed consistent agreement with the DSC data.Se sintetizaron algunos lípidos estructurados procedentes del aceite de soja con alto contenido en ácido esteárico y sus propiedades físicas se determinaron por resonancia magnética nuclear pulsada (NMR, punto de goteo Mettler y calorimetría diferencial de barrido (DSC. Se sintetizaron 1,3 diestearo-2-oleina (SOS, 1,3 diestearo-2-linoleina (SLS y 1,3 diestearo-2-linolenina (SlnS a partir de 1,3 diacilgliceroles y de los ácidos grasos adecuados puros. Las determinaciones de NMR pulsada en el rango de temperaturas 10- 50 ºC mostraron que los triacilgliceroles simétricos (SUS: donde S = esteárico, U = oleico, linoleico o linolénico funden a mayor temperatura y más bruscamente, todos presentan altos contenidos en sólidos a todas las temperaturas hasta los 33.3 ºC, estando completamente fundidos

  8. Plaguicidas y cáncer de mama en mujeres cordobesas Pesticides and breast cancer in women from Cordoba

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    M. L. Jodral Villarejo

    2001-06-01

    Full Text Available La exposición a contaminantes ambientales constituye en la actualidad un problema importante en salud pública, sobre todo con respecto al papel que dichos tóxicos juegan como carcinogenéticos. Este hecho junto con la incidencia creciente del cáncer de mama en España y de que no existe una relación clara entre esta patología y la exposición a plaguicidas, conduce a plantearnos evaluar el papel de los plaguicidas como factor de riesgo en el cáncer de mama en mujeres cordobesas.Se realiza un estudio de casos-controles en 134 mujeres que fueron sometidas a intervenciones quirúrgicas por lesiones mamarias en el Hospital Universitario Reina Sofía de Córdoba. A todas se les realiza un cuestionario, así como un estudio anatomopatológico y determinaciones en grasa mamaria de cuatro plaguicidas (HCB, HCH, p,p’DDE y Aldrín mediante cromatografía de gases.Tras el estudio anatomopatológico se estableció que 69 presentaban lesiones malignas (casos y 65 lesiones benignas (controles. Las determinaciones analíticas respecto a los 4 plaguicidas, detectan niveles elevados de p,p’DDE en todas las muestras, seguidas del HCB y Aldrín y en menores niveles y muestras se detecta el HCH.El análisis univariante detectó la edad, duración de la lactancia y niveles de Aldrín como factores de riesgo en las lesiones malignas, pero el análisis multivariante identificó los niveles del pesticida Aldrín como el factor más significativo en dichas lesiones (p Se establece la relación causal entre Aldrín y cáncer de mama, y se sugiere la necesidad de realizar nuevos estudios para eliminar los factores de confusión.Exposure to environmental contaminants is an important public health problem, specially because of its possible carcinogenic effect. The raising incidence of cancer breast in Spain, together with the absence of clear association between this pathology and exposure to pesticides motivated us to assess the possible etiological role of

  9. Development of a chromatographic method for the study of the stability and compatibility of Mexican fuel oils; Desarrollo de un metodo cromatografico para el estudio de estabilidad y compatibilidad de combustoleos mexicanos

    Energy Technology Data Exchange (ETDEWEB)

    Blass Amador, Georgina; Panama Tirado, Luz Angelica [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1992-11-01

    compatibility of fuel oil mixes. [Espanol] En Mexico, la mayoria de la energia electrica producida proviene del uso de combustibles residuales pesados conocidos como combustoleos los cuales han sufrido disminuciones en la calidad debido a una combinacion de factores, entre los que destaca el de los cambios en el proceso de refinacion. Es necesario desarrollar metodos que sean capaces de indicar la inestabilidad (formacion de sedimento o incremento en viscosidad durante el almacenamiento o calentamiento) o incompatibilidad (formacion de sedimento al mezclar dos o mas) de los combustoleos utilizados en las centrales termoelectricas. El objetivo de este trabajo fue el desarrollar una prueba alternativa para el estudio de la compatibilidad y/o estabilidad de combustoleos mexicanos empleando cromatografia de liquidos de alta resolucion (CLAR) y asi poder determinar aspectos estructurales del combustoleo que determinan su estabilidad. Dado que la formacion de sedimentos ocurre cuando el poder disolvente del combustible es inadecuado para mantener los asfaltenos en solucion, es importante conocer la medida del poder disolvente o aromaticidad del diluyente; asi pues, la primera parte de este trabajo se centro en la determinacion del perfil de compuestos aromaticos de los diluyentes de los combustoleos, la otra parte se dedico a la determinacion del perfil de distribucion de los pesos moleculares de los asfaltenos presentes en los combustoleos. Los perfiles de la fraccion aromatica, asi como los de distribucion de pesos moleculares se determinaron empleando cromatografia de liquidos, en la que se empleo una variedad de columnas y de disolventes. Se efectuo una combinacion de pruebas de rutina tales como contenido de asfaltenos, equivalencia de tolueno, viscosidad, etcetera con el fin de obtener correlaciones con el metodo cromatografico desarrollado. En este articulo se discute solo la seccion correspondiente a la obtencion del perfil de contenidos de aromaticos de los combustoleos. Se

  10. El tránsito vehículo-peatonal desde un punto de vista psicocultural

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    Gilbert Ulloa Brenes

    2011-12-01

    Full Text Available El objetivo de este artículo es proponer una serie de insumos epistemológicos y teóricos, como aproximación psicocultural, desde la cual se entienda el tránsito de vehículos y peatones en calidad de campo cultural propio de la sociedad moderna industrializada. Dicha propuesta sintetiza parte de los resultados de una investigación básica previa. La idea central de este trabajo supone que, en el tránsito vehículo-peatonal, se expresan aspectos como el ideal del maquinismo, algunos elementos de la ideología capitalista y una forma particular de constitución de los sujetos que participan en él. La construcción teórica se basa en las tesis de Max Horkheimer sobre las determinaciones sociales en procesos como la percepción y la formación de conceptos, las formulaciones de Pierre Bourdieu respecto a la constitución de los campos sociales y la perspectiva de Jacques Lacan en torno a lo simbólico y la identificación. A partir de esta propuesta, se concluye que una perspectiva psicocultural del tránsito de vehículos y peatones se basaría en la indagación sobre la racionalidad y la ideología imperante en los fenómenos asociados al tránsito vehículo peatonal, en la consideración de la estructura particular de este campo y en la forma como lo simbólico ubica a los sujetos participantes en él.

  11. Leptospira interrogans en una población canina del Gran Buenos Aires: variables asociadas con la seropositividad

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    Rubel Diana

    1997-01-01

    Full Text Available Se determinó la seroprevalencia de leptospirosis en una población canina suburbana con el objeto de analizar la asociación entre distintas variables individuales y ambientales y la seropositividad a leptospirosis. El estudio, de diseño transversal, se llevó a cabo durante julio de 1992 en un barrio del Gran Buenos Aires en el que viven unos 9 500 habitantes y una población canina de unos 2 000 animales. Se estudió una muestra aleatoria de 223 perros, de cada uno de los cuales se obtuvo una muestra de sangre. La ficha epidemiológica del animal se obtuvo por encuesta al ama de casa. Las determinaciones serológicas se realizaron por microaglutinación frente a 10 serotipos de Leptospira interrogans. Se halló seropositividad en 57% de los 223 perros examinados; 82% de los sueros positivos coaglutinaron con dos o más serotipos. Los serotipos detectados con mayor frecuencia fueron canicola y pyrogenes. La seroprevalencia en hembras fue menor que en machos (P <0,05 y entre los cachorros de menos de 1 año de edad, menor que en los animales de mayor edad (P <0,01. El callejeo del perro y la presencia de agua estancada frente a la vivienda del propietario fueron los factores de riesgo más importantes entre los que se estudiaron. Las asociaciones de la seropositividad con el contacto con un basural, con el comportamiento de caza del perro y con la presencia de roedores en la vivienda no fueron estadísticamente significativas. Se discuten distintas medidas de control.

  12. Leptospira interrogans en una población canina del Gran Buenos Aires: variables asociadas con la seropositividad

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    Diana Rubel

    1997-08-01

    Full Text Available Se determinó la seroprevalencia de leptospirosis en una población canina suburbana con el objeto de analizar la asociación entre distintas variables individuales y ambientales y la seropositividad a leptospirosis. El estudio, de diseño transversal, se llevó a cabo durante julio de 1992 en un barrio del Gran Buenos Aires en el que viven unos 9 500 habitantes y una población canina de unos 2 000 animales. Se estudió una muestra aleatoria de 223 perros, de cada uno de los cuales se obtuvo una muestra de sangre. La ficha epidemiológica del animal se obtuvo por encuesta al ama de casa. Las determinaciones serológicas se realizaron por microaglutinación frente a 10 serotipos de Leptospira interrogans. Se halló seropositividad en 57% de los 223 perros examinados; 82% de los sueros positivos coaglutinaron con dos o más serotipos. Los serotipos detectados con mayor frecuencia fueron canicola y pyrogenes. La seroprevalencia en hembras fue menor que en machos (P <0,05 y entre los cachorros de menos de 1 año de edad, menor que en los animales de mayor edad (P <0,01. El callejeo del perro y la presencia de agua estancada frente a la vivienda del propietario fueron los factores de riesgo más importantes entre los que se estudiaron. Las asociaciones de la seropositividad con el contacto con un basural, con el comportamiento de caza del perro y con la presencia de roedores en la vivienda no fueron estadísticamente significativas. Se discuten distintas medidas de control.

  13. A new method of damage determination in geothermal wells from geothermal inflow with application to Los Humeros, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Aragon, A [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico); Moya, S. L [Centro Nacional de Investigacion y Desarrollo Tecnologico, Cuernavaca, Morelos (Mexico); Garcia-Gutierrez, A; Arellano, V [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2008-10-15

    Geothermal inflow type curves were obtained for different values of well damage (i.e., inflow performance relationships). The method was evaluated by diagnosing the damage of thirteen producing wells in the Los Humeros, Puebla, Mexico geothermal field. Permeability determinations were carried out for these wells and their productivity indices were estimated. Comparison of the diagnoses made via damage effects against the results of field pressure tests showed that the maximum difference between both approaches is on the order of 0.7 damage units. The methodology allows reservoir characterization along its productive life, since several production tests are carried out while the reservoir is producing. The data obtained from production tests are used to determine the damage effect and permeability of the rock formation. Previously the damage (skin factor) could only be determined from the analyses of transient pressure tests. [Spanish] Se presenta la obtencion de curvas-tipo de influjo geotermico para diferentes valores de dano, y se demuestra su aplicacion en los analisis de produccion de pozos geotermicos determinando el dano en trece pozos del campo geotermico de Los Humeros, Puebla, Mexico. Tambien se hicieron determinaciones de la permeabilidad en las zonas de produccion de estos pozos y de sus respectivos indices de productividad. Se compararon los resultados del valor de dano obtenido con la metodologia propuesta, con los valores de dano obtenidos a partir de pruebas de presion, encontrando que las diferencias maximas entre ambas tecnicas es del orden de 0.7 unidades de dano. La presente metodologia permite la caracterizacion del yacimiento a lo largo de su vida productiva a partir de las mediciones de las pruebas de produccion efectuadas en los pozos. La metodologia propuesta es innovadora porque anteriormente el dano solamente se podia determinar a partir de los analisis de las mediciones de la pruebas de presion.

  14. DE LA PREGUNTA ¿QUÉ ES LA CRÍTICA?, A ¿QUÉ HACE LA CRÍTICA? PARA FINALMENTE INDAGAR ¿A QUIÉN LE INTERESA LA CRÍTICA TELEVISIVA?

    Directory of Open Access Journals (Sweden)

    Yamila Heram

    2010-01-01

    Full Text Available En el siglo XX se produjo una amplia proliferación de las industrias culturales (radio, televisión, video, Internet. Esta masificación de la cultura otorgó un nuevo lugar a la crítica, anteriormente reservada a la literatura y extensiva a otras artes, y luego prolongable a los medios masivos de comunicación como objeto de interés. En lo que respecta a la crítica televisiva, se parte de un problema, que podríamos resumirlo como el de analizar, interpretar y evaluar “un objeto democrático”; todos consumimos televisión y todos tenemos algo para decir acerca de ella, pero ¿a quién le importa la crítica televisiva? Por eso, de los tres interrogantes que se desprenden del título nos interesa detenernos en este último, ya que si bien no pretendemos obviar definiciones, ni funciones, consideramos que el énfasis en esta última pregunta acarrea un análisis por las determinaciones. A modo de hipótesis consideramos que una posible y contextual respuesta permitirá dar cuenta de los desplazamientos y tensiones en la manera de abordar la temática de la televisión por parte del campo académico por un lado y por el otro, de cierta prensa de interpretación y orientación cultural.

  15. Contracción, hinchamiento y peso específico aparente de madera de eucalipto colorado (Eucalyptus tereticornis Smith

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    Andrea Cardoso

    2013-12-01

    Full Text Available Con el objetivo de contribuir al conocimiento del comportamiento de la madera de Eucalyptus tereticornis en Uruguay, se estudió la contracción y el hinchamiento lineal y volumétrico para diferentes condiciones de humedad relativa, a una temperatura de 25 ºC. Se construyó una isoterma parcial dándole importancia a las condiciones de humedad de equilibrio en las que es posible encontrar productos realizados con esta madera en Uruguay, por ejemplo, pisos interiores o exteriores. De cinco árboles de una cortina de 50 años ubicada en el departamento de Durazno se seleccionaron discos a dos alturas. A partir de estas se prepararon probetas para las determinaciones de contracción e hinchamiento. Se encontró que el peso específico aparente básico fue de 0,630, al 12% de contenido de humedad fue de 0,859 y al 15 % de 0,872. La contracción radial, tangencial y volumétrica fue de 7,04%, 14,70% y 20,64%, respectivamente, y el hinchamiento radial fue de 7,61%, el tangencial de 17,61% y 26,62% el volumétrico. Sobre la isoterma se observó una diferencia esperable entre la curva de sorción y la de desorción en el rango de humedad relativa estudiado de 53% a 84%.

  16. Thermal behavior of building materials based in woody fibers; Comportamiento termico de materiales constructivos a base de fibras lenosas

    Energy Technology Data Exchange (ETDEWEB)

    Flores Murrieta, Fernando E; Bojorquez Baez, Inocente; Llovera Esteban, Arturo; Hernandez Rodriguez, Jose [Universidad de Quintana Roo, Chetumal, Quintana Roo (Mexico); Perez Sanchez, Maria M [Universidad Autonoma de Yucatan, Merida (Mexico)

    2000-07-01

    A Test development to obtain the thermal conductivity and the study of thermal performance of building materials by a device of the Guarded Hot Plate (25 x 24.8 cm) according to standards ASTM C 518-91 and C 717-97, in a range of low temperatures (23-50 Celsius degrees) are presented in this work. The device consist of a structure whit: heat source system; heat dissipator system; plates and specimens fastener, and assembly of thermocouples and insulated plates. Subsequently in the experiments, will be necessary to reach a steady state to different temperatures for monitoring the thermal gradient. Another side, considering the electric power of the overall system and the modified Fouriers equation for two specimens, we can obtain the thermal conductivity, for instance: Plaster; woods and new materials based on woody fibers. [Spanish] En este trabajo se presenta el estudio del comportamiento termico y desarrollo de prueba de conductividad termica tanto en materiales de construccion como aquellos basado en fibras lenosas en un rango de bajas temperaturas (23-50 grados Celsius). De acuerdo con las normas ASTM C-518-91 y C-177-97, se utiliza un dispositivo de placa caliente guardada de 25 x 24.8 cm. que requiere de dos muestras identicas de especimenes diferentes colocadas entre una fuente de calor y una fuente fria aisladas termicamente. Se presenta el desarrollo experimental para determinar la conductividad termica en estado estacionario a varias temperaturas de operacion en materiales constructivos tales como: yeso, madera de pino y a base de fibra lenosa. Los dos primeros materiales se han utilizado como referencia en la comparacion de las propiedades termofisicas que aparecen en la bibliografia tecnica. Lo cual nos permite tener un buen grado de confiabilidad en el dispositivo utilizado en la determinacion de dichas propiedades.

  17. Ontología de la resistencia

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    Mario Teodoro Ramírez Cobián

    2017-07-01

    Full Text Available A partir del uso político-social del término “resistencia”, este ensayo propone un análisis filosófico del concepto de resistencia a través de ciertos pensadores importantes del siglo XX y lo que va de este siglo. Se analiza así el concepto fenomenológico y ontológico de resistencia en cuanto cualidad ontológica (el Ser es lo que resiste a las determinaciones epistémicas y antropológicas en Merleau-Ponty y autores recientes vinculados al llamado nuevo realismo o realismo especulativo (Meillassoux, Harman, Ferraris. A través de una recuperación de ideas de Deleuze y Foucault, se ofrece un concepto político de resistencia como proceso “primario” respecto al poder, a partir de lo cual se propone una redefinición de la democracia como el poder de resistencia del pueblo. Fromthepolitical and social use of theterm "resistance", thispaperproposes a philosophicalanalysis of the concept of resistancethroughcertainimportantthinkers of thetwentiethcenturyand so farthiscentury. Thephenomenological and ontological concept of resistance as ontological quality is analyzed (the Being is what resists epistemic and anthropological determinations in Merleau-Ponty and recent authors linked to the so-called new realism or speculative realism (Meillassoux, Harman, Ferraris. Throughrecovery of ideas of Deleuze and Foucault it´soffered a concept of resistance as "primary" processwithrespect to power, fromwhich a redefinition of democracy as the power of the people for resistance.

  18. Concentración de inmunoglobulinas totales en calostros de vacas en explotaciones lecheras de Costa Rica

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    Jorge Alberto Elizondo-Salazar

    2015-01-01

    Full Text Available El objetivo del presente estudio fue determinar la concentración de inmunoglobulinas (Igs totales en el calostro producido por vacas lecheras y establecer el efecto que la raza y el número de parto pueden tener sobre dicha concentración. Los datos corresponden a determinaciones de concentración de Igs totales determinadas por medio de un calostrómetro en 537 muestras obtenidas entre los años 2010 y 2012, durante los meses de agosto a noviembre en 50 fincas lecheras ubicadas en las provincias de San José, Alajuela, Heredia y Cartago. Las razas de las vacas se clasificaron en Holstein, Jersey, cruce HolsteinxJersey y otras. El tamaño de las fincas osciló entre 10 y 300 vacas en ordeño. Para fines del presente estudio, se consideró un calostro de buena calidad cuando la concentración de Igs fue ≥ 50 mg/ml. La concentración de Igs osciló entre 10 y 140 con un promedio de 85 mg/ml. Del total de muestras analizadas, 13,2% presentaron una concentración inadecuada de Igs. Al considerar el efecto de raza sobre la concentración de Igs, no se encontraron diferencias significativas. El efecto de número de parto de la vaca influyó significativamente sobre la concentración de Igs encontrándose que a mayor número de parto la concentración de Igs aumenta. La información del estudio indica que la calidad de calostro es alta y que una falla en la transferencia de inmunidad pasiva podría deberse a factores como el volumen del calostro consumido, y el tiempo que transcurre desde el nacimiento y la primera toma de calostro.

  19. The financing of the petroleum industry in the world; El financiamiento de la industria petrolera en el mundo

    Energy Technology Data Exchange (ETDEWEB)

    Romo Rico, Daniel; Galina Hidalgo, Sergio [Instituto Mexicano del Petroleo, (Mexico)

    2004-06-15

    The complexity in the development of the oil industry makes it to be an important requester of financial, technological and human resources. In particular, the subject of the financing receives special relevance because of the determination of assigning resources to the investment implies to face diverse factors of risk that limit the return for the resource providers. The objective of this work is to determine the proportions of the problems to finance the oil industry and to illustrate the different forms of financing more used in the world as much by companies as from by oil countries governments. It is established that there is an ample range of financing alternatives; same that are based on the different contexts faced by the companies and governments. One concludes that exist three large tendencies of study for the problem of the financing in the world: a) the employed by the transnational corporations; b) the one used by independent oil companies and c) the one that is used in the nations with hydrocarbon reserves. [Spanish] La complejidad en el desarrollo de la industria petrolera, le hacen ser una importante demandante de recursos financieros, tecnologicos y humanos. En particular, el tema del financiamiento cobra especial relevancia porque la determinacion de asignar recursos a la inversion implica enfrentar diversos factores de riesgo que limitan el retorno para los proveedores de los recursos. El objetivo de este trabajo es dimensionar la problematica para financiar la industria petrolera e ilustrar las distintas formas de financiamiento mas usadas en el mundo tanto por empresas como por gobiernos de paises petroleros. Se establece que hay una amplia gamma de alternativas de financiamiento, mismas que estan en funcion de los distintos contextos enfrentados por las empresas y gobiernos. Se concluye que existen tres grandes tendencias de estudio para el problema del financiamiento en el mundo: a) el empleado por las corporaciones trasnacionales; b) el

  20. La destrucción del estatuto antropomorfo del narrador en la obra de Juan José Saer

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    Rafael Arce

    2014-04-01

    Full Text Available El trabajo propone una hipótesis que busca ceñir la singularidad de todos los narradores en la obra de Juan José Saer. Para ello, traza una genealogía de la instancia narrativa saeriana como voz fenomenal. La categoría propuesta propone pensar al narrador saeriano como una relación conciencia-mundo en la cual se disuelve tanto la consistencia de la objetividad, presupuesto de la novela realista, como la consistencia de la subjetividad, presupuesto de la novela de vanguardia. El narrador saeriano plantea un tipo de interrogación que intenta disolver las certezas narrativas, incluso las negativas, para trabajar en el terreno raso de la experiencia, entendiendo por ésta la relación entre un sí-mismo sin subjetividad y un mundo de cosas que se desprende de sus determinaciones objetivantes.   Abstract   This work proposes a hypothesis that tries to stick to the singularity of every narrator in the work of Juan José Saer. For that, it traces a genealogy of Saer’s narrative instance as amazing voice. The proposed category suggests thinking about the Saer’s narrator as a relationship between conscience and world where both the consistency of objectivity, an estimation of the realist novel, and the consistency of subjectivity, an estimation of the vanguard novel, are dissolved. The Saer’s narrator sets a kind of interrogation that tries to separate the narrative truths, even the negative ones, to work on the flat ground of experience, understanding by this the relationship between oneself without subjectivity and a material world that can be deduced of its objectifying determinations.

  1. Calidad fisicoquímica, microbiológica y toxicológica de leche cruda en las cuencas ganaderas de la región Puno –Perú

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    Magaly Brousett-Minaya

    2015-01-01

    Full Text Available El objetivo del presente trabajo fue evaluar la calidad de la leche cruda en cuanto a sus propiedades fisicoquímicas, microbiológicas y toxicológicas en siete cuencas representativas de la región Puno. Los resultados fueron comparados con los estándares establecidos en la Norma Técnica Peruana para leche y productos lácteos NTP 200.001-2003 y con la Norma oficial mexicana NOM-155-SCFI-2012 para los parámetros de proteína y lactosa en ausencia de parámetros peruanos. Para la caracterización fisicoquímica se determinó pH, acidez, densidad, contenido de grasa, proteína, lactosa, sólidos totales y sólidos no grasos; también se realizaron análisis microbiológicos de E. Coli y mesófilos. Del mismo modo el estudio abarcó el análisis de residuos de pesticidas como son organoclorados, organofosforados, carbamatos y piretroides en concentración de 1,0 ug/g de muestra los cuales dieron resultados negativos para los cuatro grupos de pesticidas, las determinaciones fisicoquímicas en más del 50% de las cuencas (a excepción de acidez y pH se encontraron dentro de los estándares de la NTP y la NOM. La presencia de mesófilos en su mayoría fueron encontrados dentro de los parámetros establecidos a excepción de dos cuencas lecheras y en cuanto a E. Coli ninguna cuenca cumplió con las normas establecidas encontrándose una leche de baja calidad higiénica.

  2. Calculo Preliminar de la Tasa de Meteorización del Batolito Antioqueño, Cordillera Central, Colombia

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    Carolina Garcia

    2004-12-01

    Full Text Available Este trabajo es una estimación preliminar del tiempo necesario para generar la espesa capa de saprolito que caracteriza el perfil de meteorización actual de un batolito cuarzodiorítico cretácico que aflora en altiplanos de la Cordillera Central de Colombia, entre 5º50' y 7º00' de latitud Norte y 74º50' y 75º35' de longitud Oeste y a alturas entre 750 y 2700 m.Se utilizan datos obtenidos previamente mediante el análisis de la composición química de las aguas superficiales de cuatro cuencas con áreas diferentes, ubicadas sobre el Batolito Antioqueño, al este de Medellín. Los cáculos se hicieron con el método basado en la pérdida de componentes en solución utilizando diferentes valores de solutos. Al utilizar la pérdida de sílice se obtiene un tiempo de meteorización de unos 6 x 10 6 años, comparable con el obtenido mediante la datación de las cenizas volcánicas mas antiguas que recubren la topografía actual y que indican la fecha mínima de configuración de la superficie de erosión.A pesar de resultar de una serie de suposiciones simplificadoras, este resultado es interesante y justifica la realización de determinaciones mas detalladas. Confirma la larga preservación de superficies de erosión antiguas conformadas sobre un saprolito que desde hace varios millones de años no ha sido sometido a una erosión profunda, fenómeno poco común en una zona tectónicamente activa como la estudiada.

  3. La iniciativa económica local tras la ley 27/2013, de 27 de diciembre, de racionalización y sostenibilidad de la administración local

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    Fernando Garcia Rubio

    2015-06-01

    Full Text Available La reforma local de 2013 ha supuesto un cambio en el ámbito de la actividad y competencias locales que con respecto a la iniciativa económica de las entidades locales supone una absoluta supeditación al principio de estabilidad presupuestaria del art 135 de la Carta Magna de estas. Así el presente trabajo pretende analizar las nuevas determinaciones del art 86 LRBRL , tras la modificación de este por la ley 27/2013, de 27 de diciembre y las condiciones y formas de ejercicio de la actividad económica de las corporaciones locales partiendo del estudio desde la jurisprudencia , la doctrina , el derecho comunitario y la legislación estatal y autonómica de dicho ejercicio sus formas y modalidades , el procedimiento y los requisitos para ello, determinando el nuevo modelo de actividad económica local. The local reform of 2013 has been a change in the scope of activity and local powers with respect to economic initiative of local authorities is an absolute subordination to the principle of budgetary stability art 135 of the Magna Carta of these. So this paper analyzes the art 86 LRBRL new determinations, following the amendment of this by law 27/2013, of 27 December and the conditions and forms of exercise of economic activity of local government from the study from the jurisprudence, literature, Community law and national and regional legislation for that year its forms and modalities, the procedure and requirements for it, determining the new model of local economic activity.

  4. Deconstruyendo espejos coloniales. Primeras aproximaciones al análisis situacional del liderazgo indígena en el Tawantinsuyu, Siglos XV-XVI

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    Horacio Miguel Hernán Zapata

    2011-01-01

    Full Text Available El presente artículo parte de una deconstrucción del “espejo” con que los los funcionarios de la Corona española y las diferentes órdenes religiosas concibieron a las antiguas organizaciones nativas de autoridad andina (kurakas, mallkus, inkas, en tanto éstas fueron asimiladas a los sistemas de autoridad propios de las dinastías europeas, que en términos generales eran más centralizados y jerárquicos. Dicha deconstrucción intenta inscribir las estrategias y prácticas de liderazgo indígena en un nuevo “espejo” explicativo y comprensivo, observando tanto las determinaciones socioculturales como la capacidad de agencia de los actores, mostrando de esa manera que el acceso a la jefatura y su ejercicio dependían, además de las virtudes personales del sujeto, de la constitución de una red de parentesco, reciprocidad y de alianzas extendida. El objetivo de este trabajo es indagar las singulares prácticas sociales y políticas de las sociedades andinas en la conformación de las estructuras de poder y autoridad bajo el orden estatal del Tawantinsuyu. Proponemos identificar, a través de la interpretación etnohistórica de un corpus documental, los mecanismos de legitimación y de ejercicio del poder asumidos por los kurakas y los gobernantes inkas.

  5. Characterization of traffic-generated pollutants in Bucharest

    Energy Technology Data Exchange (ETDEWEB)

    Raducan, G. [University of Bucharest, Faculty of Physics, Department of Atmospheric Physics, Magurele, Bucharest (Romania)]. E-mail: gabi_raducan@yahoo.com; Stefan, S. [University of Bucharest, Faculty of Physics, Department of Atmospheric Physics, Magurele, Bucharest (Romania)

    2009-01-15

    European Union Council directive 96/62/EC on ambient air quality assessment and management requires the development of action plans for zones where the concentrations of pollutants in ambient air exceed limit values. In the urban areas the limit values are exceeded, especially due to the traffic. In this paper, we analyzed the temporal variability levels of concentration of NO{sub X}, O{sub 3} and SO{sub 2} in two street canyons. The distribution of concentrations proves that traffic is the most important source of NO{sub X}, this pollutant being emitted during running of the vehicle engines. The level of pollution within U2 street is 25% less than U1 street, even though the measured traffic within U2 street is 50% less than within U1 street. This happen because the streets geometry and locations are different. [Spanish] La directiva 96/62/EC del Consejo de la Union Europea sobre determinacion y manejo de la calidad del aire ambiental establece que deben existir planes de accion para las zonas donde la concentracion de contaminantes excede los valores limite. En las areas urbanas dichos valores limite se rebasan en especial debido al trafico. En este trabajo analizamos la variabilidad temporal de los niveles de concentracion de NO{sub X}, O{sub 3} y SO{sub 2} en dos canones urbanos. La distribucion de las concentraciones demuestra que el trafico es la fuente mas importante de NO{sub X}, contaminante que se emite por la operacion de los motores vehiculares. El nivel de contaminacion en la calle U2 es 25% menor que el de la calle U1, aun cuando el trafico cuantificado en la calle U2 es 50% menor que el de la U1. Esto se debe a que la geometria y la ubicacion de las calles es diferente.

  6. Energy use and production, demography and the world-market oil price-influencing twenty years of economic performance and environment degradation in Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Lopez Lemus, Luis Gerardo [SUNY College of Environmental Science & Forestry (United States)

    1997-07-01

    I present a compilation of data describing Mexico's economic performance as it relates to demographic and natural resource characteristics. Statistical correlations suggest that long term economic output and energy efficiency are influenced mostly by human population numbers and fuel consumption rate, although its fluctuations have been clearly driven by those of the world-market oil price throughout 1970-90. Neither energy production, agricultural yield, OPEC's oil price or forest coverage appeared important in determining Mexican GDP response for this 20-year period. Significant relations of these fluctuations were found also in the rates of deforestation, air pollution and agricultural production, being all of these variables seemingly independent of the intrinsic human population growth rate. I discuss how Mexico could bridge the GDP gap with its current Nafta partners from this system-energy perspective. [Spanish] Presento una coleccion de datos que describen el comportamiento de la economia de Mexico relacionado con las caracteristicas demograficas y de sus recursos naturales. Las correlaciones estadisticas sugieren que la produccion economica a largo plazo y la eficiencia de la energia estan influenciadas principalmente por las cifras de poblacion humana y por el regimen de consumo de combustible, si bien sus fluctuaciones han sido claramente impulsadas por los precios del petroleo en mercado mundial a traves de 1970 a 1990. Ni la produccion de energia, el rendimiento agricola, el precio del petroleo de OPEC o la extension de los bosques resultaron importantes en la determinacion de la respuesta del PIB de Mexico para este periodo de 20 anos. Se encontraron relaciones significativas de estas fluctuaciones tambien en los regimenes de deforestacion, contaminacion del aire y produccion agricola, siendo todas esta variables de forma similar independientes de regimen intrinseco del crecimiento de la poblacion humana. Analizo como podria Mexico salvar la

  7. Medición de cortisol y sus fracciones: Una puesta al día

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    Patricia Maidana

    2013-12-01

    Full Text Available La determinación del cortisol sérico total forma parte fundamental de la exploración bioquímica de la función adrenocortical. Dado que esta hormona circula en plasma, en parte unida a proteínas de transporte y en parte en estado libre, existe la posibilidad de realizar la determinación de sus diferentes fracciones no solo en sangre sino también en orina, saliva y otros fluidos biológicos. Es posible realizar tanto determinaciones basales como pruebas funcionales y de esta manera evaluar la secreción de cortisol en un momento dado del día, estudiar su variación circadiana y analizar su relación con el resto de los componentes del eje hipotálamo-hipófiso-adrenal. Las mediciones habituales de cortisol en sangre, saliva y orina reflejan los niveles de esta hormona en el momento de la recolección o durante un período de 24 horas. Recientemente han aparecido trabajos en los cuales se propone la determinación de cortisol en cabello y uñas como potenciales marcadores del estatus hormonal en períodos más prolongados. El objetivo de esta revisión es realizar una puesta al día acerca de la metodología disponible actualmente en nuestro medio para la evaluación del eje adrenal, haciendo hincapié en su aplicación para el diagnóstico clínico.

  8. Caracterización físico-química y organoléptica de miel de Melipona beecheii obtenida en sistemas agroforestales

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    Leydi Fonte

    Full Text Available La investigación se realizó en la Estación Experimental de Pastos y Forrajes "Indio Hatuey", con el objetivo de determinar las características organolépticas y físico-químicas de la miel producida por Melipona beecheii. Para la extracción y el envasado de la miel se utilizaron jeringuillas estériles y frascos secos esterilizados, debidamente etiquetados. Después, se detectó en la muestra la presencia de granos de polen pertenecientes a Gliricidia sepium, y se realizó un análisis sensorial y físico-químico basado en los siguientes indicadores: aspecto, color, olor, sabor, textura, humedad (g/100 g, acidez libre (meq/100 g, pH y sólidos solubles (g/100 g = %. Además, se realizaron determinaciones cromatográficas de los azúcares presentes. Los valores de pH estuvieron alrededor de 3,6; la acidez libre fue de 35,0 meq/100 g, y la humedad, de 24 %. Por su parte, el análisis sensorial estuvo acorde con las especificaciones de calidad recomendadas en la norma de calidad cubana, ya que la miel no presentó ningún sabor, aroma o color desagradables. Se concluye que la miel de M. beecheii presentó una excelente calidad, al no sufrir ningún proceso de degradación aparente; por ello se puede considerar como una miel fresca, lo que constituye un requisito clave para cualquier alimento destinado al consumo humano.

  9. Vasculitis asociadas a anticuerpos anti-citoplasma de neutrófilos: Clínica y tratamiento

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    María Virginia Paolini

    2013-04-01

    Full Text Available Las vasculitis asociadas a anticuerpos anti-citoplasma de neutrófilos (ANCA comprenden a un grupo de enfermedades caracterizadas por la inflamación de la pared de pequeños vasos. Analizamos las características epidemiológicas y clínicas en una serie de 47 pacientes: 23 (49% granulomatosis de Wegener (GW, 15 (32% poliangeítis microscópica (PAM y nueve (19% vasculitis limitada al riñón (VLR. La edad media al inicio de los síntomas fue de 50.7 ± 14.9 años. La manifestación clínica más frecuente fue el compromiso renal en 41 (87% pacientes, seguido por el pulmonar en 26 (55% y el otorrinolaringológico en 17 (36%. En 26 (55% se asoció compromiso renal y pulmonar. La forma clínica más frecuente fue la generalizada en 23 (49%, seguida por la grave en 18 (38%. El 89% presentaron determinaciones de ANCA positivas. Cuatro (8% no recibieron tratamiento inmunosupresor de inicio. De los 43 que recibieron tratamiento de inicio, 29 (67% tuvieron remisión completa, con un tiempo de remisión promedio de 35.3 meses. Once (26% presentaron recaídas, diez (91% recaídas mayores y uno (9% menor. Doce (28% fallecieron, siete en forma temprana y cinco durante la evolución de la enfermedad. Quince (31% evolucionaron a insuficiencia renal crónica. Los 26 pacientes en seguimiento tuvieron respuesta al tratamiento y 20 (77% de ellos estaban en remisión al finalizar el estudio. Las vasculitis asociadas a ANCA continúan siendo enfermedades de alta morbilidad y mortalidad, a pesar de las mejorías logradas con los tratamientos inmunosupresores.

  10. Ungüento ZZ, antiséptico elaborado con una zeolita natural modificada

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    Iliana Perdomo López

    1998-12-01

    Full Text Available Se realizó el diseño del ungüento ZZ a partir del producto activo zeolítico ZZ, el cual posee una marcada actividad antimicrobiana en el tratamiento de las micosis y afecciones bacterianas. Se elaboraron 3 formulaciones las cuales se evaluaron mediante determinaciones físico-químicas. La formulación I respondió a la utilización del ungüento hidrófilo como base, la II a la crema secante y la III a una base emulsionada aceite en agua. Se obtuvo como resultado la no utilización de las formulaciones I y II por la interacción del principio activo con el laurilsulfato de sodio y con el monoestearato de glicerilo, respectivamente. La formulación III resultó muy adecuada desde el punto de vista tecnológico y se le realizaron estudios toxicológicos de irritabilidad dérmica que resultaron favorables, ya que no hubo irritación de las zonas tratadas.ZZ oinment was designed from an active zeolite product which has a marked antimicrobial effect in the treatment of micosis and bacterial affections. Three different formulations were evaluated for the product through physicial-chemical determinations. Formulation I used hidrophil oinment as a base; formulation II used drying cream and Formulation III chose an oil-in-water emulsified base. As a result of this assessment, formulations I and II were not chosen because of the interaction of the active agent with sodium laurylsulphate and with glyceril monostereate respectively. Formulation III turned out to be the most suitable from the technological viewpoint. Toxicological studies were performed on this formulation to observe skin irritability but the results were favourable since there was no trace of irritation in the treated areas.

  11. Intervención educativa para las enfermedades de transmisión sexual ITS/VIH/SIDA

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    José Manuel Contreras Tejeda

    2014-08-01

    Full Text Available Se realizó un estudio de intervención educativa con los pacientes del Reparto Nuevo Salomé, perteneciente al Policlínico Julio Antonio Mella del municipio de Camagüey; con el objetivo de elevar el nivel de conocimientos sobre las ITS/VIH/SIDA por haberse detectado un alza en los índices de las enfermedades de trasmisión sexual (ITS/VIH/SIDA, con valores por encima de la media mantenida en esa área. El periodo de estudio estuvo comprendido entre los meses de enero y junio de 2013 y el universo de estudio estuvo constituido por toda la población del área, quedando conformada la muestra por 120 pacientes, con edades entre 16 y 56 años; éstos pacientes dieron su consentimiento para participar en la investigación. Se les aplicó un cuestionario para evaluar el nivel de conocimientos sobre las ITS/VIH/SIDA antes y después de la intervención, se empleó un método educativo basado en técnicas afectivas participativas. Se hicieron determinaciones de laboratorio a todos los pacientes. Los datos obtenidos fueron procesados mediante el sistema estadístico SPSS y presentados en tablas. Al final de la intervención, el 84.1% de los pacientes mostraron conocimientos sobre la identificación de las ITS, el 76.6% en lo referente a las vías de transmisión y el 82.5% sobre los factores de riesgo. Las técnicas afectivas participativas empleadas fueron efectivas en el incremento de los conocimientos de los pacientes

  12. Divagaciones: la ciudad, el campo, la comunicación

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    Gustavo M. Quesada

    2015-01-01

    Full Text Available Espero plantear algunos puntos para un debate de tiroteo entre el alcalde y un pequeño propietario la comunicación rural en una perspectiva de rural. Me pregunto, ¿es esto desarrollo? integración campo-ciudad. En estos puntos se En la integración campo-ciudad es necesario anotarán las diferencias del campo y de la ciudad. Su comprender que, en la mayoría de los casos, el explicación requerirá elaboraciones teóricas y campo lleva todas las probabilidades de perder. La metodológicas particulares. Al hablar de tecnología de producción, las determinaciones sobre comunicación rural, hay que considerar que la política agrícola y las operaciones de descripción de sus problemas alude a otros campos comercialización se realizan en la ciudad bajo su del conocimiento que podrían tratarse ampliamente influjo. Cubriré este debate bajo el prisma de como comunicación de las minorías o comunicación educador / comunidad rural. popular. Quizá así se pueda aspirar a un desarrollo pesar de que el área que abarca la que sirva para evitar nuevos suicidios o tiroteos enseñanza de la comunicación ha sido causados por errores tecnológicos. y a propósito de últimamen te una de las más, fértiles, citaré suicidios y tiroteos allá van dos hechos que mucho aquí como punto de referencia solamente me impresionaron.

  13. Rapigluco-test. Resultados de la evaluación externa y pruebas de terreno

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    Niurka Russeaux Guía

    2000-12-01

    Full Text Available Se evaluó el RapiGluco-Test en el Centro Nacional de Referencia para el Laboratorio Clínico. El intervalo de linealidad resultó satisfactorio entre 2,5 y 22 mmol/L de glucosa y la recuperación del método fue del 90 %. En el estudio de exactitud, tanto para los lotes experimentales como para los de escalado, se encontró buena correlación con los métodos de referencia utilizados. La precisión evaluada a 2 niveles de concentración fue buena. Se distribuyeron 49 lotes del reactivo en hospitales y policlínicos de todo el país y se realizaron 1 818 000 determinaciones de glucosa entre 1993 y 1996. No se presentaron quejas en relación con el comportamiento del producto.The RapiGluco-Test was evaluated at the National Center of Reference for Clinical Laboratory. The lineality interval was successful between 2.5 and 22 mmol/L of glucose and the recovery of the method was of 90%. During the accuracy test it was found that both the experimental lots and the scale-up lots had a good correlation with the reference methods used. The precision evaluated at 2 levels of concentration was also good. 49 lots of the reagent were distributed in hospitals and polyclinics all over the country. 1 818 glucose determinations were obtained from 1993 to 1996. There were no complaints about the behaviour of the product.

  14. La fórmula del cuerpo sin órganos una aproximación Bergsoniana a su enunciación

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    Miguel Ruiz Stull

    2011-01-01

    Full Text Available Tomada desde Artaud por Deleuze ya desde la redacción de Lógica del sentido (1969, la expresión de cuerpo sin órganos (CsO no deja de causar al menos perplejidad. En su enunciación se traman puntos cruciales de la filosofía de Deleuze desde su teoría del acontecimiento y de la diferencia, pasando por una definición y una analítica del deseo, hasta una determinada noción de vida que articularía el proceso de su generación. Sin desestimar lo anterior y los profusos usos y determinaciones actuales que ha cobrado esta noción, nuestro propósito es vincular al CsO con la concepción de vida, que según nuestra lectura, se halla en la base de su formulación. Esto permanece en el texto como subyacente, y nuestra propuesta se inscribe en determinar el grado de influjo que posee el vitalismo de Bergson en la concepción de esta fórmula: desde este punto de vista es plausible sostener que el CsO es una operación que se funda de modo crucial en una lectura atenta al élan vital de bergsoniano. En suma, si el CsO es una involución creadora por definición de su proceso, no es sino porque su puesta en marcha significa y se efectúa en una constante y radical lucha que implica cada vez el desmontaje o desmembramiento de la idea de organismo.

  15. Influencia de la producción integrada del olivar sobre la calidad del aceite de oliva virgen

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    Gutiérrez-Rosales, F.

    2006-12-01

    Full Text Available A study has been conducted to determine the influence of integrated olive production on the quality of extra virgin olive oil. On two different dates, samples from three different holdings were taken in integrated production (I parcels, and in conventional production (C parcels, both adjacent. The analytical determinations were free acidity, peroxide value, K232 and K270, fatty acid composition, esterols, phenolic compounds, tocopherols, stability to oxidation and sensory analysis. Most interesting among the results obtained were total contents of esterols and tocopherols, higher in olive oils of integrated production.Se ha realizado un estudio para ver la influencia de la producción integrada del olivar sobre la calidad del aceite de oliva virgen. Se tomaron muestras de aceitunas de tres fincas distintas, en parcelas correspondientes a olivar de secano, de producción integrada (I, y en parcelas adyacentes a estas de producción convencional (C, en dos fechas diferentes. Las determinaciones analíticas realizadas han sido acidez libre, índice de peróxidos, K232 y K270, composición de ácidos grasos, esteroles, compuestos fenólicos, tocoferoles, estabilidad oxidativa y análisis sensorial. En los resultados obtenidos destaca que los valores más altos de esteroles totales y tocoferoles corresponden a los aceites de producción integrada. Así mismo, los aceites de producción convencional presentan mayor contenido de fenoles totales y parecen ofrecer mayor estabilidad.

  16. Valores de transaminasas en cabras criollas infectadas con Trypanosoma vivax Transaminases values in Creole goats infected with Trypanosoma vivax

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    Emir Espinoza

    2002-01-01

    Full Text Available La presente comunicación reporta los valores de las enzimas transaminasas, Aspartatoaminotransferasa (AST y Alaninaaminotransferasa (ALT encontrados en sueros de cabras infectadas con la cepa de Trypanosoma vivax Stock (TvIIV y sus controles. Las determinaciones se realizaron durante un lapso experimental de diez semanas, divididos en dos períodos iguales (pre y post-infección por intermedio de un método colorimétrico, utilizando kits comerciales. Los datos fueron analizados mediante la prueba t Student's. En el caso de la AST, la comparación de las medias parciales de ambos grupos infectado y control, no indicó diferencias estadísticas. Con respecto a la ALT, la contrastación de las medias parciales de pre y post-infección del grupo de cabras infectadas, señaló diferencias significativas (PThe present communication reports the transaminases enzymes values Aspartatoaminotransferase (AST and Alaninaaminotransferase (ALT in serum from goats infected with the Trypanosoma vivax Stock (TvIIV. The determinations were realized during a ten week experimental period divided into two equal periods (pre- and post-infection by colorimetric method, using commercial kits. The dates were analyzed through the t Student's test. In the AST case, the comparison between partial means of infected and control groups did not show any statistical differences. In relation to ALT, the contrast of partial means to pre- and post-infection from infected goats group indicated significant differences (P<0.01.

  17. [Not Available].

    Science.gov (United States)

    Zubiaga, Lorea; Ruiz-Tovar, Jaime; Giner, Lorena; González, Juan; Aguilar, María Del Mar; García, Alejandro; Calpena, Rafael; Durán, Manuel

    2016-07-19

    Introducción y objetivo: el IMC puede resultar engañoso para ciertas complexiones corporales, por lo que se han propuesto otros parámetros como la adiposidad (calculada a través de fórmula CUN-BAE,) el índice de Framingham de riesgo cardiovascular (IF) y el índice aterogénico (IA) (rCT/HDL-c) como predictores de riesgo cardiovascular. Se propone comparar estos factores como marcadores de éxito terapéutico tras cirugía en pacientes obesos sometidos a gastrectomía vertical laparoscópica (GVL) como procedimiento de cirugía bariátrica.Material y métodos: realizamos un estudio observacional prospectivo de pacientes sometidos a GVL y con un periodo de seguimiento mínimo de 1 año. Analizamos la evolución de IMC, adiposidad, IF e IA.Resultados: analizamos 140 pacientes. El IMC preoperatorio fue de 49,1 kg/m2, con una adiposidad del 54,8%, un IF 7,54% y un IA de 4,2. A los 12 meses el IMC era de 28,4 kg/m2, con una adiposidad del 39,4%, un IF del 3,7% y un IA de 1,64. En función de estos resultados, a los 12 meses el IMC medio está en rango de sobrepeso, la adiposidad en niveles de obesidad (obesidad: > 25% en hombres y > 35% en mujeres), el IF en rango de riesgo cardiovascular bajo (solo en las determinaciones posoperatorias. Estos elementos suponen herramientas útiles para valorar la disminución del riesgo de enfermedad cardiovascular después de cirugía bariátrica.

  18. Validez concurrente y predictiva de la escala de cribado de estilo de vida delictivo revisada -ECEViD R-

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    Jorge Luis Castillo

    2009-10-01

    Full Text Available Antecedentes. La metodología de evaluación del riesgo de violencia ha evolucionado en los últimos tiempos. Las predicciones efectuadas en el sistema judicial requieren determinaciones basadas en evidencias y transparencia en sus procedimientos. Objetivos. Evaluar la validez concurrente y predictiva de la versión argentina de la Lifestyle Criminality Screening Form Revised -LCSF-R-, denominada escala de cribado de estilo de vida delictivo revisada -ECEViD R-. Material y métodos. Luego de traducir al español y adaptar al medio local la LCSF-R, se evaluó una cohorte de 100 personas candidatas consecutivas a liberación o alta del servicio penitenciario de la provincia de Buenos Aires con la ECEViD R y otras tres escalas: la Psychopathic Checklist Revised (PCL R, la Assessing Risk For Violence (HCR 20 y la Violence Risk Appraisal Guide (VRAG. El reclutamiento duró quince meses y el seguimiento, en promedio, dos años y medio. Se consignaron eventos violentos y delitos no violentos; se chequearon pérdidas por fallecimiento y salida del país. Se recabó la información mediante fuentes de información múltiples. Resultados. Éstos permiten sostener la validez concurrente de la ECEViD. Respecto de la validez predictiva no se obtuvieron resultados positivos significativos. Conclusión. Los autores sugieren que la ECEViD R resulta ser un instrumento candidato apropiado para el cribado en evaluaciones de riesgo de violencia, dado el comportamiento similar presentado con instrumentos más complejos.

  19. Long term vision on the use of the renewable energies in Mexico: Solar energy. First Part: Evaluation of the Solar Resource in Mexico (Annexe 6-I in 'A vision of year 2030 on the use of the renewable energies in Mexico'); Vision a largo plazo sobre la utilizacion de las energias renovables en Mexico: Energia solar. Primera Parte: Evaluacion del Recurso Solar en Mexico (Anexo 6-I en 'Una vision al 2030 de la utilizacion de las energias renovables en Mexico')

    Energy Technology Data Exchange (ETDEWEB)

    Estrada Gasca, Claudio A; Arancibia Bulnes, Camilo A; Dorantes Rodriguez, Ruben; Islas Samperio, Jorge; Muhlia Velasquez, Agustin [Universidad Nacional Autonoma de Mexico (Mexico)

    2005-08-15

    The application of the solar energy requires an evaluation of the solar resource. It is understood by evaluation the determination of the amount of solar energy available to be used in an application; from the point of view of the present applications it is advisable to distinguish two: the direct solar radiation and the diffuse solar radiation, that conform what it is known as the global solar radiation, or hemispheric. All the solar collectors have capacity to use the direct radiation, their capacity to use diffuse radiation depends on the concentration factor of the radiation that characterizes them. Another distinction that can be done is the measurement of different parts from the spectrum. It is not simple to predict the value of the solar radiation in a site or given moment, this has implications in the design of solar facilities, which are constructed to operate during a large number of years. [Spanish] La aplicacion de la energia solar requiere una evaluacion del recurso solar. Se entiende por evaluacion a la determinacion de la cantidad de energia solar disponible para ser utilizada en una aplicacion; desde el punto de vista de las aplicaciones actuales conviene distinguir dos: la radiacion solar directa y la radiacion solar difusa, que conforman lo que se conoce como la radiacion solar global, o hemisferica. Todos los colectores solares tienen capacidad de utilizar la radiacion directa, su capacidad de usar radiacion difusa depende del factor de concentracion de la radiacion que los caracteriza. Otra distincion que se puede hacer es la medicion de diferentes partes del espectro. No es sencillo predecir el valor de la radiacion solar en un sitio o momento dado, esto tiene implicaciones en el diseno de instalaciones solares, las cuales se construyen para operar durante un numero grande de anos.

  20. Geochemistry of tertiary-quaternary lavas of Mt. Oku Northwest Cameroon

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    Njilah Konfor

    2007-01-01

    Full Text Available El Monte Oku ocupa la posición central en el sector continental de los volcanes de la Línea Volcánica de Camerún (CVL. Las observaciones del terreno, petrográfica mayor, huella y REE geoquímica, indican que esas lavas son basanita/basalto alcalino trachita/reolita junto al boquete composicional dentro del terreno benmoreita. Este boquete, que no se puede explicar por diagonal de muestreo, puede por lo tanto reflejar la densidad de filtración dentro del sistema magmático. Sin embargo, la acumulación y la fragmentación de las mayores fases minerales: piroxenas, olivinos y plagioclasa, parecen haber controlado la evolución del magma. La cristalización ha mostrado ser el mayor proceso de diferenciación que da a lugar al espectro de los magmas de este estrato-volcán, aunque la contaminación cortical en el nivel superior de las cámaras del magma no puede ser impedida en este medio continental intra-plato. Las determinaciones K-Ar age indican que la actividad volcánica del Monte Oku ocurrió en tres episodios precisos, 25-22 Ma, 18-14 Ma y < 1 Ma. No hay evidencia de actividad volcánica entre 14 y 1 Ma. Para edades < 1 Ma BP, la actividad volcánica fue reasumida creando conos y cráteres abundantes.

  1. “PORQUE TE QUIERO…” UNA MIRADA A LA VIOLENCIA BASADA EN GÉNERO EN LAS RELACIONES DE NOVIAZGO EN LA CIUDAD DE CARTAGENA DE INDIAS

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    Ana Milena Montoya Ruíz

    2013-08-01

    Full Text Available Las relaciones de noviazgo marcan el desarrollo de la vida de los jóvenes, en ellas se desarrollan las primeras experiencias íntimas con otros diversos y las prácticas amatorias, que influirán en la construcción de su proyecto de vida, razón por la cual es necesario conocer comprender y sensibilizar sobre las manifestación de algunas conductas violentas que se presentan en este momento de la vida, e identificar cuáles de ellas se basan en la condición de género. Este trabajo ficar cuáles de ellas se basan en la condición de género. Este trabajo pretende ser una reflexión para transformar los patrones y determinaciones sociales que han hecho de la unión amorosa, en los jóvenes,relaciones de sometimiento en las cuales se prolongan la inequidad de los géneros y se manifiestan diversas tipos de conductas constitutivas de violencia física y simbólica, usadas como forma de resolver los conflictos y acordar las reglas de la amorosidad. Presentamos los resultados del estudio de las experiencias amatorias y de encuentro, de los jóvenes estudiantes de tres instituciones de y de encuentro, de los jóvenes estudiantes de tres instituciones de flexiones que han tratado de explicar qué promueve la violencia de género entre la población juvenil.

  2. Los idiomas iberorrománicos en los elementos de lingüística románica de Petar Skok

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    Pavao Tekavčić

    1992-12-01

    Full Text Available La cultura hispánica, una de las más prestigiosas del mundo, está presente también, desde hace mucho tiempo, entre las naciones eslavas meridionales. Además de evidentes influencias literarias (véase el recientemente aparecido primer tomo de nuestra revista, un elemento de esta presencia es el conocimiento de las lenguas romanicas de la Península Ibérica, en primer lugar naturalmente del castellano. En las páginas que siguen entendemos el estudio de las lenguas iberorrománicas a nivel universitario, lo que abarca además la evolución de los tres idiomas desde el latín hasta su estado actual: es decir, su gramática histórica (el termíno es, desde hace algún tiempo, un tanto odioso, pero clara y cómodo. Más aun, el estudio histórico de las lenguas iberorromanicas incluye tambien Ia comparaci6n con otros idiomas emparentados (gramatica romanica comparativa y Ia determinacion del Iugar de los idiomas romanicos de Iberia en la Romania. Estas disciplinas, que a primera vista pueden parecer reservadas a especialistas de lingüística histórica románica, son en realidad importantes partes de la cultura de una nación, y son una de las no mínimas piedrezuelas del gran mosaico llamado Romania.

  3. Incidencia de factores de riesgo y modalidades de enfermedad ateroesclerótica en pacientes de Puerto Padre

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    Caridad María Osorio Sosa

    2014-08-01

    Full Text Available Se realizó un estudio transversal descriptivo con 1049 personas mayores de 40 años, que acudieron al Laboratorio Clínico del Hospital General Docente “Guillermo Domínguez López” en el período comprendido entre mayo de 2012 y junio de 2013, con el objetivo de caracterizar los factores de riesgo y las modalidades de enfermedad aterosclerótica en una población de Puerto Padre. Se realizaron, a través de métodos enzimáticos y colorimétricos, las dosificaciones séricas de colesterol total, triglicéridos, HDL colesterol, creatinina, urea. También se efectuaron las determinaciones de LDL colesterol, proteinuria de 24 horas y microalbuminuria. Se encontró que los factores de riesgo de enfermedad ateroesclerótica fueron el hábito de fumar, la hipertensión arterial, la diabetes mellitus y la obesidad. También en la mayoría se encontraron dislipidemias, siendo la hipertrigliceridemia la más frecuente en todos los grupos de edades. Además, una gran parte de estos pacientes presentaron niveles alterados en las lipoproteínas, fundamentalmente bajos niveles de HDL colesterol. Se debe resaltar el hecho de que la mayoría de los pacientes con enfermedad ateroesclerótica definida tuvieron alteraciones en los valores de las pruebas de función renal, y que todos presentaron microalbuminuria positiva

  4. Argumentos para una Sociología posthumanista y postsocial Arguments for a Postsocial and Posthumanistic Sociology

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    Fernando J. García Selgas

    2010-11-01

    Full Text Available En este trabajo articulo y desarrollo una serie de argumentos en favor de una mirada sociológica posthumanista que no siga identificando sociedad con espacio nacional ni definiéndola como la agregación de individuos humanos o como el conjunto de determinaciones que rigen su vida en común. Lo primero es mostrar que, como en el paso de la comunidad tradicional a la sociedad o asociación moderna, ahora transitamos hacia una realidad social como ensamblaje que descentra al ser humano. Lo siguiente es deshacerse del reflejo anti-fetichista de las ciencias sociales para poder admitir la agencia social por parte de los objetos, a lo cual nos ayuda bastante el entender como la lógica tecnocientífica de la mutua constitución de investigadores y objetos de estudio se extiende a la totalidad de la realidad social. Para terminar presento también la cara constructiva y propositiva de este posthumanismo.

     

    My aim in this paper is to articulate and develop several arguments for a posthumanist, sociological perspective in which society is not confined within, and identified as, national space or defined as aggregation or structural determination of human beings. My first argument is a plea for a new social transition from the modern idea of association to the idea of a not human-centred assemblage, like we moved from community to society. In order make it easier to assume the social agency of objects I help to get ride of the anti-fetishism bias in social sciences and show, at the same time, how the logic of technoscience, in which researchers and scientific objects are mutually constituted, is pervading the whole social reality. Last, but not least, I undertake a brief presentation of the constructive side of posthumanism in Sociology.

     

  5. LA SITUACIÓN DEL PERSONAL AL SERVICIO DE LA ADMINISTRACIÓN LOCAL

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    Lorenzo Mellado Ruiz

    2015-01-01

    Full Text Available Se analizan en este artículo los aspectos más importantes relacionados con el empleo público local derivados de la reforma del régimen local español de 2013. Sobre la base de los principios centrales de control, estabilidad presupuestaria, recuperación de las competencias estatales y limitación del personal, se estudian las nuevas previsiones sobre el personal eventual y directivo, el nuevo y detallado régimen de los funcionarios locales con habilitación de carácter nacional y las modificaciones en materia de régimen retributivo, número de altos cargos y funciones de intervención. Se ha pretendido, sobre todo, verificar el grado de cumplimiento y desarrollo de las nuevas determinaciones a un año de la entrada en vigor de la Ley. The aim of this paper is to deal with the most outstanding aspects that arise from the new regulation of public officials in Spain, after the 2013 Act. Mainly focused on the principles of control, budgetary stability, restoration of Goverment competences and limitation of the number of public officials, this paper analyze the new regulation of the local civil servants, specially the so called “funcionarios con habilitación de carácter nacional” and the modificantions in remuneration regime, quantity of senior staff and intervention functions. Furthermore, it is intended checking the degree of compliance and development the new determinations one year after it has been passed.

  6. Partículas suspendidas (PST y partículas respirables (PM10 en el Valle de Aburrá, Colombia

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    Julio César Saldarriaga Molina

    2004-01-01

    Full Text Available En el Valle de Aburrá, región noroccidental de Colombia, habitado por tres millones de personas, recorrido por 400.000 vehículos aproximadamente y con la presencia de un sector industrial textil, de alimentos y metal-mecánico importante, se evaluaron las concentraciones de partículas suspendidas totales (PST y partículas respirables (PM10, durante el período de diciembre de 2000 a junio de 2001.Las determinaciones de PST y PM10 se realizaron en diez estaciones, distribuidas de norte a sur, cubriendo zonas urbanas y rurales de los municipios de Girardota, Bello, Medellín, Itagüí, Sabaneta y Caldas. Al analizar la relación PM10/PST, se encontró que las mejores correlaciones estadísticas se localizan en las zonas centro y sur del valle de Aburrá. Además se observó la tendencia creciente en la relación PM10/PST, desde 0,527 en la estación rural Girardota (Norte, hasta 0,813 en la estación urbana Caldas (Sur.Dicho gradiente en la relación PM10/PST parece estar relacionado con el régimen de vientos que predomina en el Valle de Aburrá con dirección norte-sur, el cual hace que las partículas más pequeñas migren de norte a sur, incrementando la relación PM10/PST en la misma dirección

  7. Utilidad clínica de las pruebas hormonales e inmunológicas en la evaluación de las enfermedades del tiroides Clinical usefulness of hormonal and immunological tests for the evaluation of thyroid diseases

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    María Teresa Marrero Rodríguez

    2012-12-01

    Full Text Available Las enfermedades tiroideas son un importante problema de salud que afecta a un gran porcentaje de la población. Las pruebas bioquímicas constituyen el pilar fundamental para su diagnóstico y seguimiento. El desarrollo de ensayos de segunda y tercera generación ha supuesto un gran avance en el diagnóstico de estas enfermedades. El texto incluye los ensayos utilizados para diagnosticar y tratar las diferentes enfermedades tiroideas, provee información bioquímica y clínica actualizada contenida en secciones referidas a la utilidad clínica de las determinaciones de hormonas tiroideas totales y libres, anticuerpos antitiroideos, tirotropina humana y tiroglobulina, de manera que pueda ofrecer, tanto al laboratorio como al médico, un panorama general de la utilidad y la capacidad actual de estas pruebas.Thyroid diseases are a significant health problem affecting a high percentage of the population. The biochemical tests are the fundamental pillar for diagnosis and follow-up. The development of second and third-generation assays has represented a great advance in diagnosing these diseases. The text covers the tests to diagnose and treat a number of thyroid diseases, and provides the reader with updated biochemical and clinical information in sections about the clinical usefulness of total and free thyroid hormone determinations, antithyroid antibodies, human thyrotropin and thyroglobulin. In this way, it can offer both the lab and the physician a general overview of the usefulness and the current capability of these tests.

  8. Efectos de dos sistemas de producción en el contenido de minerales en el fruto de Musa AAB Simmonds

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    Guerra Hernández Katty Julia

    2011-12-01

    Full Text Available Los sistemas de producción orgánico y/o ecológico tienen como objetivo garantizar la sostenibilidad y la renovación de base natural, mediante la limitación del uso de productos de síntesis química para favorecer el ambiente y la salud humana. Teniendo en cuenta estas características, se estudió el efecto de los sistemas de producción orgánico y convencional sobre el contenido de nutrientes minerales del fruto del plátano Hartón (Musa AAB Simmonds, durante el proceso de maduración. Las determinaciones se realizaron en la Universidad de Córdoba (Montería, Colombia con el fin de establecer las diferencias en el contenido de minerales en los frutos en ambos sistemas y en diferentes estados de maduración. Se utilizó un diseño completamente al azar con arreglo factorial 2 x 5 y cinco repeticiones. Los factores fueron: sistema de producción y estado de maduración; los cinco niveles del segundo factor correspondieron a los grados de maduración: verde-oscuro (V, verde-claro (VC, amarillo-verde (AV, amarillo (A y muy amarillo (MA. Los resultados obtenidos muestran que entre ambos sistemas de producción y en distintos grados de maduración, se presentan diferencias significativas (P < 0.05 en los contenidos de calcio, magnesio, potasio, sodio, hierro y zinc.

  9. Cuba y el despertar de los nacionalismos en la España peninsular

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    Enric UCELAY DA CAL

    2010-02-01

    Full Text Available RESUMEN: El presente artículo analiza el papel nuclear que el nacionalismo cubano tuvo en la aparición y crecimiento de los nacionalismos contemporáneos en España. Tanto el nacionalismo español como los nacionalismos periféricos, especialmente el catalán y el vasco, estuvieron determinados por el modelo y las formas nacionalistas que surgieron de manera pionera en la Gran Antilla. Por otro lado, el enfrentamiento entre nacionalismo cubano y respuesta españolista establecería las pautas ideológicas de radicalización que posteriormente serían repetidas en contextos metropolitanos. Desentrañar esas determinaciones y esas pautas en el marco de la dimensión cubana de la política española es, pues, el tema central de este trabajo. Palabras Clave: Cuba, España, Imperio, Nacionalismo cubano, Nacionalismos peninsulares. ABSTRACT: The article analyzed the central role that Cuban nationalism played in the appearance and growth of contemporary nationalism in Spain. Both Spanish nationalism and peripheral nationalism, especially in Catalonia and the Basque Country, were determined by the nationalist model and forms that were pioneered in Cuba. Moreover, the confrontation between Cuban nationalism and the Spanish response was to establish the ideological lines of radicalization that would subsequently be repeated in metropolitan contexts. The deciphering of these determinations and these lines in the framework of the Cuban dimension of Spanish politics is thus the central theme of this study. Key words: Cuba, Spain, Empire, Cuban Nationalism, Peninsular Nationalism.

  10. Loss in tocopherols and oxidative stability during the frying of frozen cassava chips

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    Corsini, Mara S.

    2009-03-01

    Full Text Available The present study was aimed at verifying tocopherols losses and oxidative stability changes in vegetable oils used in discontinuous frying. The frying of frozen cassava chips was carried out in a household electric frying pan, where the oil was heated to a temperature of 180°C for 25 hours, with fresh oil replacement. The results obtained from the analytical determinations were submitted to variance analysis, in a factorial scheme, using a completely randomized design, making it possible to determine the influence of the type of oil and frying times on changes in the oil. The data show that the smallest changes occur in palm oil, which is more saturated. For sunflower and cottonseed oils, which are more unsaturated, there was a clear decrease in both tocopherol concentration and oxidative stability.El objetivo de este trabajo fue analizar los cambios en la concentración de tocoferoles y la evolución de la alteración oxidativa en aceites vegetales utilizados en fritura discontinua. La fritura de palitos de mandioca congelados fue realizada en una freidora eléctrica doméstica, en la cual el aceite fue calentando a 180°C, durante 25 horas, con reposición de aceite fresco. Los resultados obtenidos de las determinaciones analíticas fueron sometidos a análisis de variancia, en esquema factorial para determinar la influencia de los factores aceite y tiempo de fritura sobre las alteraciones en los aceites. Los resultados muestran que las menores alteraciones ocurren para el aceite de palma, más saturado. Para los aceites de algodón y girasol, más insaturados, se verificó que, conforme disminuyó la concentración de tocoferoles, disminuye la estabilidad oxidativa.

  11. Estabilidad en estante de tabletas de las hojas de Tamarindus indica L

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    Jesús Rafael Rodríguez Amado

    2012-06-01

    Full Text Available Objetivo: evaluar la estabilidad física, química y microbiológica, en estante, de tabletas de hojas de Tamarindus indica L. Métodos: se evaluaron las propiedades físico-mecánicas, la concentración de polifenoles, los perfiles de disolución y la calidad microbiológica durante dos años, manteniendo las tabletas envasadas en frascos de cloruro de polivinilo de alta densidad, con tapa inviolable y almacenadas en lugar seco y fresco. Se realizaron determinaciones de cada una de las propiedades cada tres meses. Resultados: Durante el estudio, las tabletas mantuvieron el color marrón claro que las caracteriza, el mismo olor fresco a fruta madura y la misma apariencia física. Las propiedades físicas se mantuvieron intactas durante dos años: dureza mayor que 5 kg/f (Monsanto, friabilidad menor que 1 %, masa y la altura dentro de la variabilidad permitida. El tiempo de desintegración fue menor que 10 min. La cantidad de polifenoles liberada en 30 min estuvo por encima del 87 % durante el estudio. Conclusiones: se demostró que las tabletas de tamarindo 120 mg, mantienen las propiedades físico-mecánicas, la concentración de polifenoles y la calidad microbiológica y biofarmacéutica durante dos años. Para asegurar la estabilidad química de las tabletas con mayor precisión, en este momento se desarrollan estudios por cromatografía de capa delgada.

  12. Kinetics of absorption of the environmental moisture in grainy materials

    Energy Technology Data Exchange (ETDEWEB)

    Villar-Cocina, E.; Valencia-Morales, E.; Gonzalez-Rodriguez, R. [Universidad Central de las Villas, Villaclara (Cuba)

    2001-02-01

    The moisture absorption in granulated materials used in foundry technologies is analyzed. The absorption process has a diffusive behavior mainly. A simple experimental technique, in which the wet weight increment was recorded as the experimental variable and an analytic method with computing procedure to find the parameters characterizing the process was used. The determination of these parameters by traditional methods is a very difficult task, very refined and expensive trials are needed. The fitting of the model permits to determine the diffusion coefficient and the moisture concentration in the separation surface between the sample and the environment. The concentration profiles are established for different times. Finally, the possibility of occurrence of superimposed diffusive processes in some materials is analyzed and the diffusion coefficient and the amount of moisture incorporated by each process are calculated. [Spanish] Se analiza la absorcion de humedad en materiales granulados utilizados en tecnologias de funcion cuyo proceso tiene un comportamiento difusivo principalmente. Se utiliza una tecnica experimental simple en la cual el incremento en peso humedo es registrado como variable experimental. Un metodo analitico con procesamiento computacional es usado para determinar los parametros que caracterizan el proceso, cuya determinacion por metodos tradicionales es dificil y requiere de ensayos muy refinados y costosos. El ajuste del modelo permite determinar el coeficiente de difusion y la concentracion de humedad en la superficie de separacion de la muestra y la atmosfera circundante. Se establecen los perfiles de concentraciones para diferentes instantes de tiempo. Finalmente, la posibilidad de ocurrencia de procesos difusivos superpuestos en algunos materiales es analizada y son calculados los coeficientes de difusion y la cantidad de humedad incorporada por cada proceso.

  13. Efectos de diferentes fracciones de harinas de trigo pan obtenidas con molino industrial sobre la calidad de galletitas dulces

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    G.N. Barrera

    2012-12-01

    Full Text Available Se evaluaron las propiedades físico-químicas y calidad galletitera de distintas fracciones de harina de trigo pan obtenidas por molienda industrial, y se compararon con una harina de trigo pan obtenida por molienda experimental. Se determinó que los procedimientos de molienda incidieron sobre el contenido de almidón dañado y el porcentaje de cenizas en las harinas. Se observó un incremento en el contenido de almidón dañado y una disminución en el contenido de cenizas. Se registraron variaciones significativas en el perfil de capacidad de retención de solventes (SRC e Índice de sedimentación en dodecil sulfato de sodio (IS-SDS. El factor galletita (FG, la dureza, la rugosidad superficial y la fracción de área de agrietamiento de las galletitas mostraron cambios significativos según la fracción de harina utilizada. El proceso de molienda afectó significativamente la capacidad de las harinas para la elaboración de galletitas. El análisis de componentes principales permitió discriminar entre las diferentes fracciones de harinas a partir de las evaluaciones fisicoquímicas y reológicas, lo que indica que la combinación de ambos tipos de determinaciones permite predecir el comportamiento tecnológico de una harina para la elaboración de galletitas.

  14. Síntesis y caracterización del almidón oxidado para su posterior evaluación como agente aglutinante en tabletas

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    Milena Díaz Molina

    1999-08-01

    Full Text Available Se realizó un estudio sobre la oxidación del almidón de maíz, con el objetivo de caracterizarlo y posteriormente evaluarlo para su posible uso en la industria farmacéutica. Se efectuó un diseño experimental donde se midió la influencia de 3 variables: concentración del agente oxidante (permanganato de potasio en medio ácido, concentración de almidón y tiempo de reacción; las 3 variables resultaron significativas. El almidón oxidado fue caracterizado mediante la determinación del contenido de grupos carbonilos y carboxilos, determinaciones físico-químicas y reológicas. En este sentido, se apreciaron variaciones de sus propiedades en comparación con las del almidón nativo. Estadísticamente, se logró correlacionar el número de grupos carbonilos en el almidón oxidado con la disminución de la viscosidad y de la temperatura de gelatinización, así como con el aumento de la capacidad de hinchamiento.The oxidation of corn starch was studied to characterize it and assess it for possible use in the drug industry. An esperimental design allowed us to measure the effect of 3 variables: exidizing agent concentration (sedium permanganate in acid medium; starch concentration and reaction time. The three variables were significant. The oxidized starch was characterized by the determination of carboxyl and carbonyl group content; physico -chemical and reologic properties. In this regard, there were changes in the oxidized properties as compared to those of the natural starch. The number of carboxyl groups was statistically correlation to a reduction in viscosity and gelatinization temperature, and to a rise in swelling capacity.

  15. Design and construction of a live insulator washing system for transformers; Diseno y construccion de un sistema de lavado en vivo para los aisladores de transformadores

    Energy Technology Data Exchange (ETDEWEB)

    Lizama-Camara, Y.A. [Universidad Veracruzana, Veracruz (Mexico)]. E-mail: yahir_lizama@ieee.org; Mendieta-Antunez, J.A.; Blanco-Brisset, E. [Industrias IEM, Tlalnepantla, Estado de Mexico (Mexico)]. E-mail: unamanu@hotmail.com; Olivares Galvan, J.C.; Escarela-Perez, R. [Universidad Autonoma Metropolitana, Unidad Azcapotzalco, Mexico, D.F. (Mexico)]. E-mails: jolivare_1999@yahoo.com; r.escarela@ieee.org

    2012-04-15

    Through the electrical industry history there have been developments of different cleaning methods to avoid the insulators flashover s due to pollution. This paper describes the principal cleaning methods applicable to transformers insulators, emphasizing the high pressure fixed-type live insulator washing method, which was applied for cleaning the insulators of 900 MVA transformer bank of the Laguna Verde power plant localized at the state of Veracruz in Mexico. We propose a transformer insulator cleaning methodology, which identifies the main variables to take into account (the voltage level of the transformers, the pollution level of the insulators, determination of the optimal wash time, the amount of water, the optimal pressure of water jet, the maximum conductivity of the water and the wind velocity), reference values are given for these variables. In addition, we present an economic cost analysis when applying a method of this kind in an electric substation. [Spanish] A lo largo de la historia de la industria electrica se han desarrollado diferentes metodos de limpieza para evitar las fallas de los aisladores de los transformadores debido a la contaminacion. Este articulo describe los principales metodos de limpieza aplicables a los aisladores de transformadores, enfatizando el sistema de lavado en vivo tipo fijo con agua a alta presion, metodo que fue aplicado para realizar la limpieza de los aisladores en el banco de transformadores de 900 MVA de la central electrica Laguna Verde, ubicada en el estado de Veracruz, en Mexico. Se propone una metodologia para la limpieza de los aisladores de transformadores, donde se identifican las principales variables a tomar en cuenta (el nivel de tension de los transformadores, nivel de contaminacion de los aisladores, determinacion del tiempo optimo de lavado, cantidad de precipitacion de agua, presion optima del chorro de agua, maxima conductividad del agua y las velocidades de los vientos) y se dan valores de

  16. Políticas de la teoría: práctica teórica y práctica política en Louis Althusser

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    Fernando Cocimano Mónaco

    2016-03-01

    Full Text Available El presente artículo tiene por objetivo problematizar la relación entre teoría y práctica política en la obra de Althusser. Asimismo, la relación entre teoría y política está íntimamente ligada al problema de la totalidad social. Es decir, para Althusser hay una relación estrecha entre el modo de concebir las prácticas y la conceptualización de la estructura social. Para ello, nos detendremos en la crítica que Althusser realizara a Hegel, puesto que condensa muchos de estos problemas. La totalidad hegeliana reduce todas las determinaciones y prácticas de la vida social al concepto produciendo de ese modo una “indistinción” entre las prácticas, en la medida en que todas ellas no son sino una manifestación del concepto. Frente a esta indistinción idealista, Althusser va a señalar la necesidad de pensar la articulación de prácticas singulares a la luz de lo que el llamará un “todo complejo y sobredeterminado”. En efecto, es a través del concepto de sobredeterminación que buscaremos pensar la primacía de la práctica política sobre la teoría. Intentaremos demostrar que esa primacía no supone un “salto a la política”, entendiendo por ello un desentendimiento de los problemas teóricos, ahora si resueltos a partir de su reducción a los conflictos políticos, sino que alude a una articulación diferencial que exige modos complejos del conocer.

  17. PESO DE HOJAS COMO HERRAMIENTA PARA ESTIMAR EL ÁREA FOLIAR EN SOYA

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    Felipe Rafael Garcés Fiallos

    2011-07-01

    Full Text Available Cuantificaciones del área foliar en plantas son importantes en estudios de daños ocasionados por enfermedades, por lo tanto su determinación requiere el uso de equipamientos que no siempre se encuentran disponibles para todos. La utilización de determinaciones indirectas, como el peso de materia fresca o seca podría ayudar en este proceso. En este trabajo, se evaluó la relación entre el peso de hojas y área foliar, a partir de plantas recolectadas en el estadío R7.1, en 64 parcelas de campo con el cultivar de soja Nidera 5909 RG. El peso fresco fue medido luego de la colecta, el peso seco después de 48 horas de incubación a 65° C y el área foliar a través de un integralizador digital Licor. Fueron obtenidas ecuaciones significativas (p < 0.0001 e R2 de 0.74 a 0.97 para cada estrato y para la planta entera. Para la media de la planta, la relación de área foliar fue de y = 45.53 x + 19.03 para peso fresco e y = 176.17 x – 75.30 para peso seco. Esta herramienta se presenta potencialmente viable para estimar el área foliar de la planta. La utilización del peso seco es mas trabajosa, más no requiere pesaje de las hojas inmediatamente después de su colecta. La utilización futura de esta herramienta requiere estudios adicionales con otros cultivares a fin de verificarse si el comportamiento es similar.

  18. Phase-conjugate interferometer to estimate refractive index and thickness of transparent plane parallel plates

    Energy Technology Data Exchange (ETDEWEB)

    Pastrana-Sanchez, R.; Rodriguez-Zurita, G.; Vazquez-Castillo, J. F. [Benemerita Universidad Autonoma de Puebla, Puebla (Mexico)

    2001-04-01

    A technique to estimate the refractive index and thickness of homogeneous plane parallel dielectric plates is proposed using a phase-conjugate interferometer, in which counting of interference fringes is employed. The light beam impinges a tilted plate before it enters a phase-conjugate interferometer, and a count of the fringes passing through a given reference at the observing plane gives the phase changes as a function of tilting angle. The obtained data is fitted to a mathematical model, which leads to the determination of both refractive index and thickness simultaneously. In this letter, experimental data from two interferometers are also discussed for comparison. One with an externally-pumped phase-conjugate mirror achieved with a BSO photorefractive crystal and another one with conventional mirrors. Results show that the phase sensitivity of the phase-conjugate interferometer is not simply twice the corresponding sensitivity of the conventional version. [Spanish] Se propone una tecnica para medir indices de refraccion y espesores de placas dielectricas plano paralelas homogeneas empleando un interferometro con fase conjugada, en el cual se usa el conteo de franjas. El haz luminoso incide en una placa inclinada bajo inspeccion antes de entrar en un interferometro equipado con un espejo conjugador de fase, y se realiza un conteo de las franjas que pasan por determinada referencia en el plano de observacion, proporcionando los cambios de fase en funcion del angulo de inclinacion. Los datos obtenidos se ajustan a un modelo, el cual conduce a la determinacion, tanto del indice de refraccion como del espesor, simultaneamente. En este trabajo se discuten datos experimentales provenientes de dos interferometros para su comparacion. Uno de ellos tiene un espejo conjugador basado en un cristal BSO fotorrefractivo, mientras que el otro es una variante con espejos convencionales. Se muestra que la sensibilidad de fase del interferometro con conjugador de fase no

  19. Resultados del estudio serológico tras la vacunación frente a Neisseria meningitidis serogrupo C en niños

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    Espín Ríos María Isabel

    2000-01-01

    Full Text Available BACKGROUND: El aumento de incidencia de enfermedad meningocócica en la Región de Murcia en la temporada 1996/97 motivó que la Dirección General de Salud desarrollara en septiembre-octubre de 1997 una Campaña de Vacunación frente al meningococo serogrupo C. El objetivo de este trabajo fue conocer el porcentaje de niños menores de 5 años de edad que mostraban seroconversión postvacunal al mes de la vacunación y el porcentaje de los mismos que conservaban inmunidad al año de la vacunación. MÉTODO: Estudio de seguimiento de 296 niños entre 18 y 59 meses de edad. Las determinaciones serológicas ser realizaron antes de la vacunación, al mes y al año de la vacunación. La titulación de anticuerpos se determinó según el "ensayo bactericida" de los Centers for Disease Control. RESULTADOS: De los 296 niños estudiados únicamente 11 (3,7% mostraron títulos de anticuerpos bactericidas antes de la vacunación. Al mes, de los niños que no mostraban anticuerpos antes de la vacunación, 167 (63,7% seroconvirtieron. Se observó una tendencia lineal estadísticamente significativa (p<0.001 de aumento del porcentaje de seroconversión con la edad de vacunación. Al año de la vacunación, de entre los niños seroconvertidos al mes de la vacunación, únicamente 6 (4,3% mostraban anticuerpos bactericidas. CONCLUSIÓN: El porcentaje de seroconversión en menores de 5 años de edad, tras la administración de la vacuna de polisacárido capsular C, presentó un claro incremento con la edad. La seroprotección adquirida en niños vacunados declina rápidamente en el año siguiente a la vacunación.

  20. Diseño y validación de un nuevo método para estimar reductores hidrosolubles asociados con la quitina Design and validation of a new method for estimation of water-soluble reducers associated with chitin

    Directory of Open Access Journals (Sweden)

    Yania Suárez Pérez

    2005-12-01

    Full Text Available Se desarrolló por primera vez un método espectrofotométrico para estimar reductores hidrosolubles asociados con la quitina materia prima. Para el ajuste del método se utilizó glucosamina como sustancia de referencia. Las determinaciones se realizaron a 330 nm que fue la longitud de onda de máxima absorción. Se seleccionó como tiempo óptimo de calentamiento 5 min y se verificó la selectividad de la respuesta analítica. Se demostró el cumplimiento de la ley de Lambert-Beer en el intervalo de 100-300 mg/mL. Se obtuvo un extracto acuoso a partir de quitina materia prima procesado para eliminar posibles interferencias, el cual se empleó como control en la validación del método. El método fue lineal, exacto y preciso en el intervalo estudiado. El límite de detección fue de 25,21 mg/mL y el de cuantificación de 65,45 mg/mL.For the first time, a spectrophotometric method to estimate water-soluble reducers associated with raw material chitin was developed. For the purpose of adjusting the method, glucosamine as a reference substance was used. The estimations were made at 330 nm that was the wavelength of maximum absorption. The selected optimal heating time was 5 min; the selectivity of analytical response was checked. The Lambert-Beer law was demonstrated in the 100-300 mg/mL interval. An aqueous extract from raw material chitin was obtained and then processed to eliminate possible interference and be used as a control for the method validation. The method was linear, exact and accurate in the studied interval. The detection limit was 25,21 mg/mL and the quantification limit was 65,45 mg/mL.

  1. Viabilidad de semillas de arroz provenientes de plantas obtenidas in vitro

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    Maylin Pérez-Bernal

    2013-04-01

    Full Text Available Se evaluó la viabilidad de semillas de arroz índica (Oryza sativa L. variedad IACuba-28 provenientes de plantas cultivadas in vitro. Dichas semillas fueron conservadas en bolsas de plástico durante 0, 2, 5, 7, 9 y 12 años en un banco de semillas a 4 °C y 34% de humedad relativa. La prueba de germinación se realizó en una muestra aleatoria de las accesiones A2000, A2003, A2005, A2007, A2010, A2012 y como prueba bioquímica se determinó la actividad alfa-amilasa en las semillas en germinación. En ambas determinaciones se incluyeron controles positivos con semillas nuevas obtenidas de plantas cultivadas en campo. Se halló una reducción progresiva del porcentaje de germinación, a medida que aumentó el tiempo de conservación en banco de germoplasma, así, a los 12 años de conservación se dio el mayor número de semillas muertas, contaminadas y plantas anormales. En todas las accesiones se observó un aumento de la actividad alfa-amilasa hasta el quinto día de germinación para luego disminuir, encontrando diferencias (P < 0.05 entre accesiones jóvenes y antiguas. La actividad alfaamilasa promedio en el quinto día de germinación fue de 0.25 en las accesiones con menor tiempo de almacenamiento, mientras que en las más antiguas fue de 0.192. La diferencia más marcada se observó en la accesión almacenada por 12 años, donde el pico de actividad sólo llegó a 0.0614. Este estudio demostró que las semillas provenientes de cultivo in vitro mantienen su viabilidad durante 10 años de almacenamiento en las condiciones del estudio; transcurrido este tiempo se perciben cambios desfavorables en los parámetros de germinación y en los niveles de la actividad alfa-amilasa.

  2. Utilidad de la recolección de orina de dos horas para el diagnóstico del tipo de acidosis tubular renal

    Directory of Open Access Journals (Sweden)

    Margarita Irene Rocha-Gómez

    2015-08-01

    Full Text Available La acidosis tubular renal se caracteriza por acidosis metabólica hiperclorémica. El diagnóstico del tipo de acidosis tubular renal se realiza mediante la medición del transporte tubular máximo de bicarbonato y de la capacidad de acidificación urinaria; sin embargo, estas pruebas son invasivas y requieren determinaciones especializadas. Objetivo: comparar la utilidad de la recolección urinaria de dos horas, una prueba relativamente simple y al alcance de muchos laboratorios, con la medición del transporte tubular máximo de bicarbonato y con la capacidad de acidificación urinaria (procedimientos de referencia para clasificar el tipo de acidosis tubular renal en pacientes pediátricos. Material y método: el estudio se realizó en niños con diagnóstico de acidosis tubular renal. El primer día se recolectó la muestra sérica y urinaria de dos horas. Al día siguiente se efectuaron los procedimientos de referencia administrando bicarbonato de sodio en 8 horas; las muestras se colectaron cada hora y se determinaron la reabsorción de bicarbonato y la acidificación urinaria.  Resultados: se incluyeron 19 pacientes y en 17 casos la colección urinaria de dos horas confirmó el diagnóstico de los procedimientos de referencia. La recolección urinaria de dos horas tuvo sensibilidad de 0.94 y especificidad de 0.67 para el diagnóstico de acidosis tubular renal distal. Conclusión: la recolección de orina de dos horas se realiza en forma menos invasiva y ofrece resultados semejantes a los procedimientos de referencia.

  3. Estudio de bioequivalencia de dos formulaciones de tabletas de carbamazepina de liberación retardada Study of bioequivalence of two carbamazepine retard-release tablet formulations

    Directory of Open Access Journals (Sweden)

    2000-03-01

    Full Text Available En 12 voluntarios sanos se efectuó un estudio de bioequivalencia de dos preparados comerciales de carbamazepina en tabletas de liberación retardada. Este estudio permitió comparar la biodisponibilidad de la formulación de referencia Tegretol® Retard de Ciba Geigy elaborado en Colombia por Novartis, y la formulación de prueba Carbamazepina MK Retard, de Tecnoquímicas. Para evaluar la bioequivalencia se determinaron las curvas de concentración plasmática vs tiempo de las dos formulaciones y se calcularon las áreas bajo la curva (AUC y las concentraciones máximas (Cmáx. Para la formulación de prueba el intervalo de confianza del 90% para el AUC estuvo entre 95.7 y 100.7% y para el C(máx entre el 88.6 y el 106.1%. Para ambas determinaciones el rango de aceptación, según normas internacionales, está entre 80 y 125% de la formulación de referencia. Esto demuestra la bioequivalencia de las dos formulaciones. A study of the bioequivalence of two comercial carbamazepine retard-release formulations was carried out in 12 healthy volunteers. Studies of bioequivalence allow to compare the bioavailability of the innovator formulation with generic, alternative or branch formulations. In order to evaluate the bioequivalence, plasma carbamazepine concentration/time curves were obtained for the Tegretol® Retard Tablets –reference formulationand for the test formulation; the area under each curve and the maximum concentration were calculated. After the calculation, statistical analysis of data for the area under the curve of the Carbamazepine Retard Tablets –test formulation, was between 95.7% and 100.7 % and the maximum concentration of the test formulation was between 88.6% and 106.1%; both parameters with the 90% confidence interval. Since the acceptance range was determined to be between 80.0% and 125.0% of the reference formulation, we concluded from this study that the two formulations are bioequivalent.

  4. Finite differences numerical model for mass and energy transport in geothermal reservoirs with carbon dioxide; Modelo numerico en diferencias finitas para el transporte de masa y energia en yacimientos geotermicos con bioxido de carbono

    Energy Technology Data Exchange (ETDEWEB)

    Moya, Sara Lilia; Ruiz, Jose Napoleon; Aragon, Alfonso; Iglesias, Eduardo [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1995-01-01

    A numerical model using finite differences method for mass and energy transport in a geothermal reservoir is presented, where the rock is considered as a porous media and the two phase-flow composed by water and carbon dioxide. The Alternating Direction Implicit (ADI) method was employed to have the advantage of generate tridiagonal matrix, and that also has shown to be efficient in mono-phase natural convection studies for porous media and cavities. It is concluded that this method has the capability of modeling two-phase flow in porous media. The mathematical formulation is for two-dimensional and transient behavior, and includes a new thermodynamic model for solubility of carbon dioxide in water, that can be applied up to 350 degrees celsius and 500 bar. Finally, this paper includes a rigorous formulation for determining thermodynamics and transport properties of binary H{sub 2}O-CO{sub 2} system. [Espanol] Se presenta un modelo numerico en diferencias finitas para el transporte de masa y energia en el sistema roca-fluido de los yacimientos geotermicos, considerando roca porosa homogenea y flujo bifasico de agua con bioxido de carbono. Se aplica el metodo denominado de direcciones alternadas implicito que tiene la ventaja de generar matrices tridiagonales y que ha mostrado ser eficiente para estudios de conveccion natural de flujos monofasicos en medios porosos y en cavidades. Se concluye que este metodo tambien tiene la capacidad de modelar flujos bifasicos en medios porosos. La formulacion matematica, bidimensional y transitoria, incluye un nuevo modelo termodinamico para la solubilidad del bioxido de carbono en agua el cual considera el comportamiento no ideal de los componentes en la mezcla gaseosa y la compresibilidad de la fase liquida, valido hasta 350 grados celsius y 500 bar. Se incluye asimismo una formulacion, lo mas rigurosa posible, para la determinacion de las propiedades termodinamicas y de transporte del sistema binario H{sub 2}O-CO{sub 2}, en el

  5. Characteristics of denatured rapeseed oil during storage and refining processes

    Directory of Open Access Journals (Sweden)

    Philen, R. M.

    2000-10-01

    Full Text Available In 1981, toxic oil syndrome, a progressive multi-system disease caused by consumption of rapeseed oil denatured with aniline occurred in Spain. To date, the causal toxic agent or agents remain unknown. Measures of acidity, moisture, impurities, phosphorous, soaps, and spectrophotometric determinations of color at 409 nm were performed. Since fatty acid anilide concentrations in these oils are associated with risk of disease, w e studied the formation of aniline-derived compounds over time after oil denaturation and by oil deodorization temperatures (200ºC, 215ºC, 230ºC, 245ºC, 260ºC, y 270ºC and times (3, 4, 4.5, 5, 5.5 and 6 hours. Formation of fatty acid anilide compounds increased with storage time. Deodorization led to a reduction of total anilides in all the samples, particularly at temperatures above 245ºC. Esters of 3-(N-phenylamino-1,2-propanediol were not detected.En 1981 tuvo lugar en España el llamado «Síndrome del Aceite Tóxico», una enfermedad progresiva multi-sistemática causada por el consumo de aceite de colza desnaturalizado con anilina. Hasta la fecha, el agente o agentes tóxicos causantes permanecen desconocidos. Se han realizado medidas de acidez, humedad, impurezas, fósforo, jabones y determinaciones espectrofotométricas de color a 409 nm. Puesto que las concentraciones de anilidas de los ácidos grasos en estos aceites se asocian al riesgo de padecer la enfermedad, se estudiaron la formación de compuestos derivados de anilina durante el tiempo de desnaturalización y con las temperaturas y tiempos de desodorización (temperaturas: 200ºC, 215ºC, 230ºC, 245ºC, 260ºC, y 270ºC y tiempos: 3, 4, 4.5, 5, 5.5 y 6 horas. La formación de anilidas de ácidos grasos aumenta con el tiempo de almacenamiento. La desodorización conlleva una reducción de la cantidad total de anilidas en todas las muestras, particularmente cuando la temperatura es superior a 245ºC. No fueron

  6. Development of applications in Internet for the calculation of solar control devices; Desarrollo de una aplicacion en Internet para el calculo de dispositivos de control solar

    Energy Technology Data Exchange (ETDEWEB)

    Perez V, Jesus B; Robles G, Saul; Villa M, Hector A; Cabanillas L, Rafael E [Universidad de Sonora, Hermosillo, Sonora (Mexico)

    2000-07-01

    In this work the development of an interactive software, visible over the World Wide Web, is presented to support the basic calculation required to control the solar gain inside buildings and houses. The site has two main parts: one part describes in a very required parameters to design devices for the control of the illumination inside the buildings, like overhangs and wingwalls for shading. The other part has the routines and procedures to calculate the sun position for any date and position over the earth, and the horizontal and vertical protection angles. The part to implement the calculations has been developed as a Java applet which can run on any platform and let the users, in an interactive way, to get the results. This software makes possible that any Internet user can run the application from his/her own computer without having to compile of use sophisticated procedures as it happens with traditional languages. With this web site it is intended to cover the necessity of having simple and reliable means for architects and civil engineers to support the use of solar energy and the saving of energy in bioclimatic design of buildings. [Spanish] En este trabajo se presenta el desarrollo de un sitio interactivo visible en el World Wide Web (WWW) que pretende servir de apoyo para los calculos basicos de control de asoleamiento en viviendas y edificios. El sitio esta conformado por dos partes principales: una parte cubre el aspecto informativo, donde en forma sencilla y clara, se explican los conceptos y parametros necesarios para disenar los dispositivos de control, alerones y parteluces. La otra parte contiene los procedimientos y las rutinas de calculo para la determinacion de la posicion solar para cualquier fecha del ano desde cualquier punto sobre la tierra, asi como los angulos de sombreado vertical y horizontal. Para la realizacion de los calculos se ha construido un applet de Java, el cual puede ejecutarse desde cualquier plataforma de computacion y

  7. Flowing equation gradually varied in rectangles channels on depth curve; Ecuacion del flujo gradualmente variado en canales rectangulares de fondo curvo

    Energy Technology Data Exchange (ETDEWEB)

    Sotelo-Avila, G.; Gallegos-Silva, J. [Universidad Nacional Autonoma de Mexico, Mexico, D.F. (Mexico)

    2002-03-01

    The study of channel flow usually have its basis in the hydrostatic distribution of pressure and the rectilinear flow hypotheses. It is from this hypothesis that the main flow equations are obtained. However, this is not applicable to a vertically curved flow that is present in a curved bed channel. This kind of channel is used to join two different slopes or in ski jumps. This kind of flow presents several changes from the rectilinear flow as in the velocity and pressure distributions and even in the energy loses. The authors of this article propose an equation of gradually varied flow for vertically-curved bed rectangular channels that adds a coefficient to modify the velocity in the calculus of the local friction gradient. With these results is possible now to analyze flow profiles in vertically-curved bed channels where before were used the methods for straight channels and therefore, increase accuracy. [Spanish] Las hipotesis del movimiento rectilineo y de distribucion hidrostatica de la presion son ciertamente las mas importantes en la hidraulica de canales, y de ellas se derivan los principales modelos de flujo que usualmente emplean. Sin embargo, no es valido aplicar la misma hipotesis y metodos de analisis al flujo curvilineo, que ocurre cuando el canal adopta curvaturas verticales en el fondo, las cuales inducen cambios importantes en la distribucion de la velocidad, presion y hasta en la perdida d energia. Tal es el caso de canales que contienen curvas verticales para unir tramos de distintas pendientes y producir el cambio en la direccion del flujo en cubetas deflectoras y vertedores en tunel. Los autores de este articulo proponen una ecuacion de flujo gradualmente variado en canales rectangulares de fondo curvo, esta es de gran utilidad en la determinacion del perfil del flujo con dichas caracteristicas, donde se plantea la adicion de un factor de amplificacion de la velocidad en el calculo del gradiente local de friccion, para tomar en cuenta el

  8. The decrease of the energy performance for the soiling of the air filters in gas turbines; Disminucion de la eficiencia energetica por ensuciamiento de filtros de aire en turbinas de gas

    Energy Technology Data Exchange (ETDEWEB)

    Romero Paredes, H.; Ambriz, J. J.; Vargas, M.; Godinez, M.; Gomez, F.; Valdez, L.; Pantoja, G. [Universidad Autonoma Metropolitana, Unidad Iztapalapa, Mexico D. F. (Mexico)

    1995-12-31

    The object of this paper is to study the effect in the turbine output of a gas turbine of the conditions of the compressor air inlet in going through a series of filters. The algorithm for the calculation of the energy losses due to the variation of the pressure drop caused by the filters according to their cleanliness condition. In the first part the series of variables that affect the gas turbines performance are exemplified, afterwards the characteristics of the air flow into a turbine are presented as well as their effects on the system. Later on, the results obtained of the system simulation are presented and compared with a real case. From the results it can be determined, that depending on the system and on the environment conditions the efficiency drop might be up to 3%, in accordance with the filters cleanliness. The maintenance periods strongly depend on the air quality variations at the filter house inlet in the zone where the power plant is located. [Espanol] El presente trabajo tiene por objetivo estudiar el efecto en la potencia generada en una turbina de gas de las condiciones de entrada del aire al compresor de una turbina de gas al pasar por un conjunto de filtros. Se presenta el algoritmo para la determinacion de las perdidas energeticas debidas a la variacion de la caida de presion generada por los filtros de acuerdo con su estado de limpieza. En la primera parte se ejemplifica el conjunto de variables que influyen en la eficiencia de las turbinas de gas, posteriormente se mencionan las caracteristicas de flujo de aire hacia una turbina y se muestran los efectos sobre el sistema. A continuacion se presentan los resultados obtenidos de la simulacion del sistema y se comparan con un caso real. De los resultados se puede apreciar que, dependiendo del sistema y de las condiciones ambientales el decremento en la eficiencia puede ser hasta del 3% en funcion del nivel de limpieza de los filtros. Los periodos de mantenimiento dependen fuertemente de las

  9. Manejo agronómico de los Vertisoles en México: una revisión

    Directory of Open Access Journals (Sweden)

    Carlos Alberto Torres Guerrero

    2016-10-01

    Full Text Available Los Vertisoles ocupan el 8.3% del territorio nacional y se consideran los suelos más productivos del país. A pesar de ello, las investigaciones sobre su manejo agronómico han sido llevadas a cabo sólo en algunas localidades del país o en campos experimentales que impide la transferencia de tecnología. Varios esfuerzos se han realizado por generar información en este tipo de suelos desde 1985, sobre todo en el Altiplano Mexicano y en la zona costera del Golfo de México donde son dominantes y presentan serios problemas de degradación; sin embargo, también son comunes en otras regiones de México en las cuales se cuenta con escasa información. El objetivo de esta investigación fue realizar una revisión bibliográfica acerca del manejo agronómico de Vertisoles en México y las modificaciones que sufren sus propiedades físicas y químicas. El análisis de la información indica que los Vertisoles presentan problemas de manejo en cuatro aspectos principales: a mecanización; b compactación, c drenaje y d fertilización. No obstante su complejidad, las caracterizaciones de sus propiedades edáficas se han realizado sólo con algunas determinaciones físicas o químicas. El entendimiento de los procesos de formación puede ayudar a generar prácticas agronómicas adecuadas para cada zona agroclimática y disminuir los problemas de degradación física (compactación y química (declinación de la fertilidad que se están presentando en nuestro país.

  10. Compactación inducida por el tránsito vehicular sobre un suelo en producción hortícola Induced compaction by the vehicular traffic in a soil for horticultural crop production

    Directory of Open Access Journals (Sweden)

    Antonino Marcelo Terminiello

    2000-01-01

    Full Text Available Se realizaron ensayos en campo con el objeto de caracterizar el estado de compactación de un suelo en producción hortícola inducida por el tránsito, luego del desarrollo del ciclo de un cultivo de repollo (Brassica oleracea L. grupo capitata y su incidencia sobre el rendimiento. Se efectuaron determinaciones de resistencia a la penetración, densidad aparente y humedad gravimétrica sobre el suelo y biomasa aérea al finalizar el ciclo del cultivo en los sectores de mayor y menor número de pasajes de vehículos. Los valores de resistencia a la penetración fueron de 1,7 y 1,3 MPa, significativamente mayores para el tratamiento de más de 7 y 3 pasadas respectivamente en el rango de profundidad de 0-100 mm . No se manifestaron diferencias en el parámetro densidad aparente en la totalidad del perfil. Se encontraron diferencias estadísticamente significativas en biomasa aérea, para el tratamiento de 3 pasadas (1902.6 g planta-1, en relación al de mas de 7 pasadas (1447,9 g planta-1. El pasaje repetido sobre los surcos originan incrementos en la resistencia a la penetración a nivel superficial. El peso fresco y la materia seca del cultivo son afectados por el número de pasadas de los tractores y máquinas agrícolas.Field test were carried out with the objective of characterizing the state of compaction in horticultural soil induced by traffic, after the development of a cabbage crop (Brassica oleracea L. group capitata cycle, and its incidence on yield. Measurements of penetration resistance, bulk density, and moisture content in soil were made and aeread biomass at the end of the cycle crop in sectors with larger and smaller number of vehicles passes. Values of penetration resistance of 1.7 and 1.3 MPa were found for treatment with more than 7 passes and 3 passes respectively in the depth range of 0-100 mm. No significant differences were found in bulk density parameter in the entire soil profile. Statistically significant differences

  11. Prevalence of Colacium vesiculosum (Colaciales: Euglenophyceae on planktonic crustaceans in a subtropical shallow lake of Argentina

    Directory of Open Access Journals (Sweden)

    Yolanda Zalocar

    2011-09-01

    Full Text Available Colacium vesiculosum (Euglenophyceae is an epibiont common on planktonic microcrustaceans of continental waters. The interaction between epibionts and substrate organisms is not very well known, particularly in subtropical environments of South America. In the present work, we analyzed the prevalence, density, biomass and attachment sites of C. vesiculosum on planktonic microcrustaceans from Paiva Lake, a subtropical lake of Argentina. With the aim to evaluate whether epibionts affect the filtering rates of Notodiaptomus spiniger, the dominant planktonic crustacean, we carried out bioassays using phytoplankton Colacium vesiculosum Ehrenberg (Euglenophyceae es un epibionte común en microcrustáceos del plancton de aguas continentales. La interacción epibiontes y organismo substrato es poco conocida, particularmente en ambientes subtropicales de América del Sur. Se analiza la prevalencia, densidad, biomasa y sitios de adhesión de C. vesiculosum en microcrustáceos planctónicos de un lago subtropical de Argentina. Con el fin de evaluar si los epibiontes afectan la tasa de filtración de Notodiaptomus spiniger Brian, crustáceo dominante del zooplancton, se realizaron bioensayos utilizando el fitoplancton <53µm. Los crustáceos fueron muestreados con un tubo de PVC (1m de largo, 10cm de diámetro filtrándose 50L de agua a través de una red de 53µm de abertura de malla. El recuento de los microcrustáceos se realizó en cámaras de Bogorov bajo microscopio estereoscópico. Los organismos infectados fueron separados y observados al microscopio fotónico para determinaciones de densidad y biovolumen de los epibiontes, y su distribución en el exoesqueleto. La prevalencia de C. vesiculosum fue mayor en crustáceos adultos que en estadíos larvales y juveniles. El grupo más infestado fue el de los copépodos calanoideos en relación con su alta densidad. Los sitios de adhesión sobre el exoesqueleto fueron las regiones del cuerpo que durante la

  12. Antropometría en la evaluación nutricional de adolescentes del sexo femenino

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    Elena Cristina Vidaillet Calvo

    2002-03-01

    Full Text Available Se realizó un estudio antropométrico en 197 niñas de Ciudad de La Habana, según las normas del Programa Biológico Internacional. Se tomó peso, talla, pliegues cutáneos tricipital y subescapular, y dimensiones corporales. Los índices antropométricos fueron área grasa del brazo (AGB, índice energía/proteína (I E/P, el índice de masa corporal (IMC y área muscular del brazo (AMB. Se clasificaron en canales percentilares según las Normas de Cuba para individuos hasta los 19 años. Se buscó el valor promedio, la desviación estándar y la mediana por edad, e indicadores para evaluar el estado nutricional de la muestra. Los datos se procesaron de forma automatizada y se aplicó la prueba de significación estadística. Se halló que la muestra en su mayoría se situó a la derecha de los percentiles 4 y 5 para todas las determinaciones y que el mayor tanto por ciento de obesidad fue el punto de corte de Amador.An anthropometric study of 197 children from the City of Havana was conducted following the International Biological Programs standards. Weight, size, tricipital and subescapular falfolds and body dimensions values were taken. The anthropometric indexes were fatty area of the arm, energy/protein index, body mass index and muscle area of the arm. They were classified in percentiles according to Cuban standards for individuals aged up to 19 years. The average value, the standard deviation and median per age was estimated and also indicators for evaluating the nutritional status of the sample were found. Data were automatically processed and statistical significance test was applied. It was found that most of the sample was placed on the right of percentiles 4 and 5 for every estimation whereas the highest percentage of obesity was Amador´s cut point.

  13. ARCHAEOMAGNETIC STUDY OF THE EDIFICIO DE LAS COLUMNAS COMPLEX, EL TAJIN, MESOAMERICA (Estudio arqueomagnético del complejo del Edificio de las Columnas, El Tajín, Mesoamérica

    Directory of Open Access Journals (Sweden)

    Jaime Urrutia-Fucugauchi

    2017-12-01

    temperaturas de bloqueo. Las determinaciones de paleointensidad, que cumplen con los criterios de calidad, presentan valores altos y bajos. Posibles factores involucrados son alteraciones durante los tratamientos térmicos y la presencia de magnetizaciones secundarias. La influencia de alteraciones y de magnetizaciones multivectoriales que residen en arreglos con espectros que traslapan requiere de análisis detallados para la estimación de paleointensidades.

  14. Prevalencia de factores de riesgo para enfermedad cardiovascular en una muestra de pacientes con hipertensión arterial esencial: estudio descriptivo Prevalence of risk factors for cardiovascular disease in a sample of patients with essential hypertension: descriptive study

    Directory of Open Access Journals (Sweden)

    Solón Navarrete H

    2009-04-01

    Full Text Available Introducción: la valoración del riesgo cardiovascular permite identificar los grupos en los cuales se debe dar prioridad a las actividades de prevención (primaria y secundaria dirigidas a reducir la morbimortalidad cardiovascular. Metodología: se incluyeron 2.167 pacientes hipertensos colombianos (edad media: 62,6 años; de los cuales 56,4% eran mujeres y 43,6% hombres a quienes su médico realizó una encuesta estructurada y registró los resultados del examen físico y de las determinaciones bioquímicas para efectuar una estratificación del riesgo de enfermedad cardiovascular. Resultados: únicamente 32,1% de los pacientes tenía cifras de tensión arterial controladas al momento de la evaluación. El riesgo cardiovascular de la población en estudio fue bajo en 19,3%, moderado en 35,9%, alto en 30,6% y muy alto en 14%. La coexistencia de hipertensión arterial más diabetes incrementó la prevalencia de patologías renales, hipertrofia ventricular izquierda, enfermedad coronaria y enfermedad vascular periférica. Conclusiones: en pacientes hipertensos existe la necesidad de generar estrategias de detección y reducción efectiva del riesgo cardiovascular más allá del control de las cifras de tensión.Introduction: with the assessment of cardiovascular risk physicians can identify those groups in which they must prioritize prevention activities (primary and secondary to reduce cardiovascular morbidity and mortality. Methodology: we included 2,167 colombian hypertensive patients (average age: 62.6 years, 56.4% were women and 43.6% men, their doctors conducted a structured survey, recorded their results of physical examination and biochemical determinations for make a stratification of risk of cardiovascular disease. Results: only 32.1% of patients had controlled blood pressure levels at the survey time. This is the cardiovascular risk observed: low 19.3%, 35.9% moderate, high 30.6% and 14% very high. The coexistence of HBP + diabetes

  15. Hipoglucemia facticia inducida por insulina en un paciente diabético tipo 1 Facticious hypoglycaemia induced by insulin in a type 1 diabetic patient

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    Tania Espinosa Reyes

    2004-12-01

    Full Text Available La hipoglucemia facticia es un atentado deliberado para provocar niveles séricos bajos de glucosa con el uso de insulina o de agentes hipoglucemiantes orales. Paciente JCB, masculino, 12 años, blanco, diabético tipo 1 de 2 años de evolución. Motivo de consulta: episodios de hipoglucemia severa con convulsiones y coma. Se tomaron muestras para anticuerpos antiislotes pancreáticos (ICA y péptido C en condiciones basales y durante la hipoglucemia, así como determinaciones de hemoglobina glucosilada (HBA1 durante la evolución de la enfermedad, ultrasonografía, tomografía axial computadorizada (TAC y resonancia magnética nuclear (RMN de páncreas. Se obtuvieron insulinemias elevadas, valores extremadamente disminuidos de peptinemia C, incremento del índice de masa corporal y función renal y hepática dentro de parámetros normales. Los estudios imagenológicos fueron normales. Se concluye que a pesar de la relativa baja frecuencia de la hipoglucemia facticia en el diabético, es imprescindible tenerla en cuenta. La detección precoz facilita la atención psicológica temprana del paciente y previene la exposición a acciones que impliquen riesgo para la vida o daño permanente.Factitious hypoglycaemia is a deliberate attempt to provoke low serum levels of glucose by using insulin or lowering-glycaemia agents. A case is reported of a white, male, 12-year-old type 1 diabetic patient of 2 years of evolution. Chief complaint: episodes of severe hypoglycaemia with convulsions and coma. Samples for pancreatic anti-islet cell antibodies and peptide C were taken under basal conditions and during hypoglycaemia. Determinations of glucosylated haemoglobin (HBA1 during the evolution of the disease, ultrasonography, CAT and nuclear magnetic imaging of pancreas were performed. Elevated insulinemias, extremely reduced values of peptinemia C, increase of the body mass index, and renal and hepatic function within the normal parameters were obtained. The

  16. Caída de presión en lecho fijo de cubos de papa, remolacha y zanahoria considerando encogimiento Queda de pressão em leito fixo de cubos de batata, beterraba e cenoura considerando encolhimento

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    Javier Telis-Romero

    2003-12-01

    Full Text Available En este trabajo fue determinada experimentalmente la porosidad de lechos de cubos de papa, remolacha y zanahoria en función de la humedad con aristas iniciales de 8mm. La porosidad del lecho, con diferentes contenidos de humedad obtenida por secado a 70ºC por diferentes tempos, fue calculada utilizando las determinaciones experimentales de volumen del lecho y volumen real de las partículas. Estos dos volumenes fueran bien representados por ecuaciónes lineares basadas en la Ley de la aditividad de los volumens. La porosidad fue representada satisfactoriamente por una ecuación parabólica. La relación volumen del lecho adimensional y humedad fue representada por polinomios de tercer grado. Utilizando un equipamiento con sistema de control, fue determinada experimentalmente la caída de presión a través de un lecho fijo de cubos de papas, zanahoria y remolacha de 100mm de espesura y los resultados fueron representados de manera satisfactoria por una ecuación obtenida por una modificación empírica del modelo de Ergun. Como era de esperarse, la caída de pression aumento com la disminución de la porosidad del lecho, consequencia del encogimiento de los productos.Neste trabalho, o porosidade de leitos de cubos de batata, beterraba e cenoura com arestas iniciais de 8mm, foi determinada experimentalmente em função da umidade. A porosidade do leito, com diferentes umidades, obtidas por secagem a 70ºC por tempos diferentes, foi calculada utilizando-se as determinações experimentais de volume do leito e volume real das partículas. Esses dois volumes foram bem representados por equações lineares baseadas na lei da adtividade dos volumes. A porosidade foi representada satisfatoriamente por uma equação parabólica. A relação entre o volume do leito admensional e a umidade foram representadas por polinômios de terceiro grau. A queda de pressão através de um leito fixo de cubos de batata, beterraba e cenoura de 100mm de espessura foi

  17. Efecto de las condiciones de secado sobre el endurecimiento de los granos de caraota (Phaseolus vulgaris pretratados con vapor

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    María Virginia Mujica

    2017-12-01

    Full Text Available El endurecimiento de los granos de caraota (Phaseolus vulgaris generado por el almacenamiento en condiciones de alta temperatura y humedad relativa representa una limitante importante para su consumo. El objetivo del presente trabajo fue evaluar el efecto de un tratamiento con vapor y luego secado a los granos de P. vulgaris recién cosechados en la prevención de su endurecimiento. Inicialmente, se construyeron las curvas de secado a 40; 47,5 y 55 ºC. Seguidamente, los granos se trataron con vapor por 8 min 20 s y se sometieron a un proceso de secado, bajo un diseño central compuesto cuyos factores fueron la temperatura del aire (40 y 55 ºC y el tiempo de secado (4 y 8 h. La muestra secada de cada tratamiento se dividió en 3 lotes, el primero se analizó de inmediato y los otros se almacenaron por 5 semanas bajo 2 condiciones distintas 5 ºC/34 % HR y 37 ºC/75 % HR. Las determinaciones realizadas fueron humedad, capacidad de imbibición, tiempo de cocción y actividad de la peroxidasa soluble. El tiempo de secado fue de 6,5; 5 y 2,5 h a 40; 47,5 y 55 ºC, respectivamente, para alcanzar una humedad de 13 % (b.s.. El coeficiente de difusión resultó igual a 3,40x10-9; 3,52x10-9 y 3,87x10-9 m2/s, a 40, 47,5 y 55 ºC, respectivamente. El valor de la energía de activación fue de 7,33 kJ/mol. La aplicación de vapor y posterior secado de los granos no previno su endurecimiento, y este no dependió de la actividad de la peroxidasa soluble. Por lo que se puede inferir que los compuestos fenólicos y la enzima peroxidasa no son los únicos implicados en el mecanismo de endurecimiento de los granos de P. vulgaris.

  18. Perspectivas sobre la enseñanza de la lectura y escritura. Consideraciones acerca de la situación de la alfabetización inicial

    Directory of Open Access Journals (Sweden)

    Flor de María Rionda

    2015-04-01

    Full Text Available El trabajo surge de una investigación que indaga la situación de la enseñanza de la lectura y escritura en los procesos de alfabetización inicial de las escuelas primarias de Salta, desde la cátedra de Psicopedagogía de la Alfabetización de la carrera de Ciencias de la educación de la Facultad de Humanidades de la UNSa. El proyecto de investigación representó un espacio de reflexión que facilitó pensar la situación de la enseñanza inicial de la lectura y escritura, considerando la característica sustantiva de la investigación social, en la cual los sujetos se delimitan en interrelación con procesos históricos, determinaciones contextuales y prácticas específicas. Las prácticas alfabetizadoras, reducidas a la aplicación de uno u otro método o el solapamiento de los mismos alrededor de perspectivas innovadoras, con las que muchas veces se entra en contradicción desde las decisiones prácticas, fueron el desafío de la investigación. Desde la mirada realizada, se intentó profundizar en los significados de los proce-sos de enseñanza en situaciones escolares considerando las prácticas docentes, en rela-ción con la vigencia de los llamados métodos de lectoescritura, en las escuelas de Salta Capital. Se indagó en el espacio del aula porque es aquí donde se construyen y circulan significados en los que se pueden reconocer las relaciones y contradicciones que refle-jan los marcos teóricos y las decisiones políticas, a lo largo de los procesos históricos.

  19. Kinetic and morphological differentiation of ettringites in plain and blended Portland cements with metakaolin and the ASTM C 452-68 test. Part II: Morphological differentiation by SEM and XRD analysis

    Directory of Open Access Journals (Sweden)

    Talero, R.

    2009-03-01

    Full Text Available The same cementitious materials (OPCs, SRPCs and matekaolin, MK, the same blended cements and the same ASTM C 452-68 test than in Part I, were used. Other complementary determinations were: chemical analysis of cementing materials, SEM and XRD analysis of ettringites and specific properties of some cement tested and of their pastes.The experimental results have also demonstrated that when 7.0% SO3, equivalent to 15.05% of gypsum, was added to the M pozzolan-containing Portland cement and tested with the ASTM C 452-68 method, it was not found to behave aggressively but rather as “setting regulator ”, because the increase in mechanical strengths over time and setting times in these mixes were, therefore, similar to the pattern observed in any PC. However, when the gypsum content was raised to triple than that amount (21.0% SO3, it behaved aggressively. In both cases, logically, ettringite from both origins were involved in the resulting beneficial or adverse behavior.En esta Parte II se utilizaron los mismos materiales cementíceos (CPO, CPRS, y metakaolín, MK, los mismos cementos de mezcla y el mismo método de ensayo ASTM C 452-68 que en la Parte I. Otras determinaciones complementarias fueron: análisis químico de los materiales cementíceos, análisis por DRX y SEM de ettringitas y propiedades específicas de algunos cementos ensayados y de sus pastas.Los resultados experimentales obtenidos han demostrado también que, el 7.0% de SO3 presente en los 30 cementos de mezcla con MK, ensayados conforme el método ASTM C 452-68, no se comporta como agresivo sino como ”regulador de fraguado”, porque los tiempos de fraguado y el aumento de resistencias mecánicas fueron como los de cualquier CP. De aquí que algunos de esos cementos de mezcla puedan ser considerados “cementos hidráulicos expansivos”, el resto, no. Sin embargo, cuando la cantidad de yeso aportada fue el triple (21,0% SO3, se comportó como agresivo, motivo por el cual

  20. PRIMERAS INVESTIGACIONES SOBRE UNA ESTRUCTURA MORTUORIA SINGULAR DE CAZADORES-RECOLECTORES EN LA PATAGONIA ARGENTINA: EL ENTIERRO SHAG (The Shag Burial: Preliminary Research Results from a Singular Mortuary Structure of Hunter-Gatherers in Argentinian Patagonia

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    Leandro Zilio

    2017-03-01

    Full Text Available El entierro Shag se ubica en la costa norte de la provincia de Santa Cruz, Patagonia argentina. Se trata de una estructura con morfología anular o de anillo, de aproximadamente 10 m de diámetro, conformada por rocas. La estructura fue alterada por pingüinos de Magallanes, quienes realizaron un pozo de nidificación y, como consecuencia, expusieron en superficie una serie de restos óseos humanos. Para la Patagonia no existen antecedentes de estructuras mortuorias similares a Shag. Se presenta una datación radiocarbónica, el plano de la estructura, determinaciones bioantropológicas, estudios de isótopos estables δ13C y δ15N, y análisis tafonómicos de los restos óseos. Se interpreta que el sitio corresponde a una estructura mortuoria de cazadores-recolectores datada en el Holoceno tardío. Los estudios isotópicos permiten inferir que el individuo analizado basó su dieta en recursos de ambientes marinos y terrestres. ENGLISH: The Shag burial is located in the Santa Cruz province along the northern coast of the Argentinian Patagonia. The Shag burial site is contained by a structure with annular or ring morphology made out of rocks and approximately 10 m in diameter. The structure was altered by Magellanic penguins that built a nesting well, exposing a series of human bone remains on the surface. There is no record of similar mortuary structures within Patagonia. This paper presents a number of data including absolute radiocarbon dates, the plan of the structure, bioanthropological determinations, stable isotope studies of δ13C and δ15N, and taphonomic analyses of the bone remains. The site is interpreted to as a hunter-gatherers mortuary structure dated to the Late Holocene. The isotopic studies on the individual allow us to infer a varied diet, in which both marine and terrestrial food products were consumed.