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Sample records for bentonitas calcicas espanolas

  1. Research program to study the gamma radiation effects in Spanish bentonites; Programa de investigacion para estudiar los efectos de la radiacion gamma en bentonitas calcicas espanolas

    Energy Technology Data Exchange (ETDEWEB)

    Dies, J.; Tarrasa, F. [Universidad Politecnica de Catalunya (Spain); Cuevas de las, C.; Miralles, L.; Pueyo, J. J. [Universidad de Barcelona (Spain)

    2000-07-01

    The engineering barrier of a radioactive waste underground disposal facility, placed in a granitic host rock, will consist of a backfill of compacted bentonite blocks. At first, this material will be subjected to a gamma radiation field, from the waste canister, and heat from the spent fuel inside the canister. Moreover, any groundwater that reaches the repository will saturate the bentonite. For these reasons the performance of the engineered barrier must be carefully assessed in laboratory experiments. (Author)

  2. Las bentonitas en los detergentes ecológicos

    OpenAIRE

    Carrión Fité, Francisco Javier

    2009-01-01

    Este trabajo tuvo como objetivo principal conseguir una mejora en la suavidad del tejido de algodón en el mismo proceso lavado con tensioactivos ecológicos. Para ello, se añadió bentonita sódica al detergente, con el fin de producir un efecto de suavizado al ser lavado el tejido, pudiéndose obtener el denominado efecto “softergent”. La bentonita sódica (mineral formado por silicatos de aluminio hidratados) se mezcló con los tensioactivos utilizados en detergentes ecológicos. Este pro...

  3. USO DE BENTONITA EN AGUAS RESIDUALES DE CURTIEMBRES PARA LA REMOCIÓN DE Cr(III

    Directory of Open Access Journals (Sweden)

    Adriana Echavarria Isáza

    2010-10-01

    Full Text Available Se reporta un procedimiento eficiente para la remoción de Cr(lll de las aguas residuales de curtiembres utilizando bentonita natural y químicamente tratada. El mejor resultado se obtiene utilizando 7.5 gramos de bentonita natural para un volumen de efluente residual de 20 mi. Este sólido removió la totalidad del cromo(III presente en la muestra.

  4. Volcanic Evolution in the Galapagos: The Geochemistry and Petrology of Espanola Island

    Science.gov (United States)

    McGuire, M.; Varga, K. C.; Harpp, K. S.; Geist, D.; Hall, M. L.

    2015-12-01

    The Galapagos Archipelago consists of a series of volcanic islands located ~1,000 km west of South America that are thought to be the result of a mantle plume. The southeasternmost island, Espanola, is one of the smallest of the major islands, measuring only 7 by 14 km and reaching an elevation of 200 m. Espanola is also the oldest island in the chain, with K-Ar dates from 3.01 ± 0.11 to 3.31 ± 0.36 million years (Hall et al. 1983; White et al., 1993). The southern coast is defined by cliffs that exceed 100 m in height, made up of nearly flat-lying lavas that are each several meters thick. The northern coastline consists of lavas that dip gently toward the ocean from the highlands, as well as remnants of eroded cinder cones. Paleomagnetic measurements made in the field indicate that the western half of the island is reversely polarized, whereas most lavas measured across the eastern half are normally polarized. Major element analyses of samples from across the island indicate that fractional crystallization is the dominant process controlling chemical variations in Espanola lavas, suggesting a relatively long-lived magmatic plumbing system. Stratigraphically constrained chemical variations suggest the magma chamber may have experienced periodic replenishment by compositionally homogeneous primitive melts. Variable fluid-mobile trace element concentrations provide some evidence for contributions from ancient, recycled oceanic crust to the parental melts. Espanola lavas have more depleted Sr and Pb radiogenic isotope ratios than either Floreana or Fernandina, and lie on a mixing curve between the composition of the plume and that of the depleted upper mantle. Between ~3 and 8 Ma, the Galapagos Spreading Center was closer to the Galapagos plume than it is today. Given that Espanola was constructed during the same period, the depleted isotopic signatures suggest that plume-ridge interaction may have been a strong influence on the island's geochemical composition.

  5. Estudio descriptivo de la demanda espanola de turism en casas rurales

    OpenAIRE

    Roig Merino, Bernat

    2005-01-01

    Este estudio se plantea, como objetico generico, conocer y cuantificar la evolucion reciente de las principales caracteristicas de la demanda espanola de turismo en casas rurales. Para ello se ha efectuado una explotacion especifica de los datos de la estadistica sobre movimientos turisticos de los espanoles, que realiza el Miniesterio de Economia a traves del Institio de Estudios Turisticos. Los resultados obtenidos aportan informacion y datos nuevos sobre la evolucion reciente del turismo e...

  6. Analisis de la presencia en Internet de las empresas hortofruticolas espanolas y su relacion con el rendimento

    OpenAIRE

    Merono Cerdan, Angel Luis; Arcas Larios, Narciso; Soto Acosta, Pedro

    2007-01-01

    El objectivo de este estudio es doble. Por un lado, se analiza la presencia de sitios web en las empresas hortofruticolas espanolas y su relacion con el rendimiento de las mismas. Por otro lado, se propne y emplea una metodologia para analizar los contenidos del sitio web. Se ha analizado la presencia en Internet de 306 empresas hortofruticolas espanolas de tamano mediano, encontrando que un 10,1 por ciento todavia no cuentan con un sitio web ajeno, es decir, se trata simplemente de directori...

  7. Structure of the Espanola Basin, Rio Grande Rift, New Mexico, from SAGE seismic and gravity data

    Energy Technology Data Exchange (ETDEWEB)

    Ferguson, J.F. [Univ. of Texas, Richardson, TX (United States); Baldridge, W.S. [Los Alamos National Lab., NM (United States); Braile, L.W. [Purdue Univ., West Lafayette, IN (United States). Dept. of Earth and Atmospheric Sciences; Biehler, S. [Univ. of California, Riverside, CA (United States). Dept. of Earth Sciences; Gilpin, B. [Golden West College, Huntington Beach, CA (United States). Dept. of Physics; Jiracek, G.R. [San Diego State Univ., San Diego, CA (United States). Dept. of Geological Sciences

    1995-04-01

    Seismic and gravity data, acquired by the SAGE program over the past twelve years, are used to define the geometry of the Espanola basin and the extent of pre-Tertiary sedimentary rocks. The Paleozoic and Mesozoic units have been thinned and removed during Laramide uplift in an area now obscured by the younger rift basin. The Espanola basin is generally a shallow, asymmetric transitional structure between deeper, better developed basins to the northeast and southwest. The gravity data indicate the presence of three narrow, but deep, structural lows arrayed along the Embudo/Pajarito fault system. These sub-basins seem to be younger than the faults on the basin margins. This apparent focussing of deformation in the later history of the basin may be a response to changes in regional stress or more local accommodation of the rift extension. Future work is planned to develop seismic data over one of these sub-basins, the Velarde graben, and to better define the gravity map in order to facilitate three-dimensional modeling.

  8. BENTONITA COLOMBIANA MODIFICADA CON Al-Cu PARA LA OXIDACIÓN DE FENOL EN MEDIO ACUOSO DILUIDO

    OpenAIRE

    CARLOS ENRIQUE DAZA; SONIA MORENO; RAFAEL MOLINA

    2004-01-01

    Arcillas modificadas con Al-Cu fueron sintetizadas a partir de una bentonita colombiana variando la relación molar Cu/Al y la temperatura de hidrólisis. Los sólidos obtenidos fueron caracterizados por absorción atómica (AA), capacidad de intercambio catiónico residual (CIC) y difracción de rayos X (DRX). La oxidación de fenol en medio acuoso fue empleada para evaluar la actividad catalítica. Las arcillas obtenidas exhiben interesantes comportamientos catalíticos bajo condiciones moderadas (te...

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

    Directory of Open Access Journals (Sweden)

    C. Volzone

    2002-09-01

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

  10. Efecto del ph en la adsorción de cadmio, níquel y zinc sobre una bentonita

    OpenAIRE

    Pinilla Cuesta, Liz Adriana; Pinzón, Jorge Alejo

    2010-01-01

    Se estudió el efecto del pH sobre la adsorción de cadmio, niquel y zinc, en solución acuosa a 25"C, sobre una bentonita colombiana proveniente del Valle del Cauca. Los datos experimentales se analizaron con base en las isotermas de adsorción, la constante termodinámica de reparto Kdm (calculada mediante la isoterma de Langmuir), la relación de distribución Rd (obtenida del modelo Baeyens-Bradbury ) y una gráfica Kurbatov. La adsorción de cadmio, niquel y zinc aumenta con el pH. El or...

  11. EFECTO DEL pH EN LA ADSORCIÓN DE CADMIO, NÍQUEL Y ZINC SOBRE UNA BENTONITA

    OpenAIRE

    Liz Adriana Pinilla Cuesta; Jorge Alejo Pinzón

    2010-01-01

    Se estudió el efecto del pH sobre la adsorción de cadmio, niquel y zinc, en solución acuosa a 25"C, sobre una bentonita colombiana proveniente del Valle del Cauca. Los datos experimentales se analizaron con base en las isotermas de adsorción, la constante termodinámica de reparto Kdm (calculada mediante la isoterma de Langmuir), la relación de distribución Rd (obtenida del modelo Baeyens-Bradbury ) y una gráfica Kurbatov. La adsorción de cadmio, niquel y zinc aumenta con el pH. El or...

  12. Efecto del pH en la adsorción de cadmio, niquel y zinc sobre una bentonita

    Directory of Open Access Journals (Sweden)

    Liz Adriana Pinilla Cuenca

    2010-09-01

    Full Text Available Se estudió el efecto del pH sobre la adsorción de cadmio, niquel y zinc, en solución acuosa a 25°C, sobre una bentonita colombiana proveniente del Valle del Cauca. Los datos experimentales se analizaron con base en las isotermas de adsorción, la constante termodinámica de reparto KDM (calculada mediante la isoterma de Langmuir, la relación de distribución Rd (obtenida del modelo Baeyens-Bradbury y una gráfica Kurbatov.

  13. Efecto del pH en la adsorción de cadmio, niquel y zinc sobre una bentonita

    OpenAIRE

    Liz Adriana Pinilla Cuenca; Jorge Alejo Pinzón Bello

    2010-01-01

    Se estudió el efecto del pH sobre la adsorción de cadmio, niquel y zinc, en solución acuosa a 25°C, sobre una bentonita colombiana proveniente del Valle del Cauca. Los datos experimentales se analizaron con base en las isotermas de adsorción, la constante termodinámica de reparto KDM (calculada mediante la isoterma de Langmuir), la relación de distribución Rd (obtenida del modelo Baeyens-Bradbury ) y una gráfica Kurbatov.

  14. Aplicación de la isoterma langmuir a la adsorción competitiva de cadmio, níquel y zinc sobre una bentonita

    OpenAIRE

    Germán Darío Silva Giraldo; Jorge Alejo Pinzón Bello

    2010-01-01

    Se estudió la adsorción simultánea de los iones cadmio, níquel y zinc en solución acuosa de sus mezclas binarias y ternaria a 25°C, sobre una bentonita del Valle del Cauca, tanto en su estado natural como en su forma homoiónica de sodio.

  15. Estudio de la adsorción de cadmio, níquel y zinc sobre una bentonita natural y homoiónica de sodio

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    Germán Darío Silva Giraldo

    2010-09-01

    Full Text Available Se esmdió la adsorción de cadmio, níquel y zinc, en solución acuosa a 25 "C, sobre una bentonita procedente del Valle del Cauca, tanto en su estado natural como en su forma homoiónica de sodio.

  16. EFECTO DEL pH EN LA ADSORCIÓN DE CADMIO, NÍQUEL Y ZINC SOBRE UNA BENTONITA

    Directory of Open Access Journals (Sweden)

    Liz Adriana Pinilla Cuesta

    2010-11-01

    Full Text Available Se estudió el efecto del pH sobre la adsorción de cadmio, niquel y zinc, en solución acuosa a 25"C, sobre una bentonita colombiana proveniente del Valle del Cauca. Los datos experimentales se analizaron con base en las isotermas de adsorción, la constante termodinámica de reparto Kdm (calculada mediante la isoterma de Langmuir, la relación de distribución Rd (obtenida del modelo Baeyens-Bradbury y una gráfica Kurbatov. La adsorción de cadmio, niquel y zinc aumenta con el pH. El orden de adsorción encontrado: Cd > Ni≅Zn coincide con el establecido por el principio HSAB.

  17. Los depósitos de bentonita de Barda Negra y cerro Bandera, departamento Zapala, provincia del Neuquén, Argentina Bentonite deposits of Barda Negra and Cerro Bandera, Zapala Department, Neuquén Province, Argentina

    OpenAIRE

    A. Impiccini; J. M. Vallés

    2002-01-01

    Las bentonitas de la región nordpatagónica pueden ser agrupadas en dos distritos mineralogenéticos caracterizados desde el punto de vista geológico, geográfico y estratigráfico. En este trabajo se considera a las bentonitas terciarias localizadas en la región occidental, en el departamento Zapala, provincia del Neuquén. Los depósitos consisten en estratos lenticulares, subhorizontales, de 2 a 15 metros de espesor, la mayoría de ellos aflorantes. Están incluidos en la Formación Collón Curá, un...

  18. Los depósitos de bentonita de Barda Negra y cerro Bandera, departamento Zapala, provincia del Neuquén, Argentina

    Directory of Open Access Journals (Sweden)

    A. Impiccini

    2002-09-01

    Full Text Available Las bentonitas de la región nordpatagónica pueden ser agrupadas en dos distritos mineralogenéticos caracterizados desde el punto de vista geológico, geográfico y estratigráfico. En este trabajo se considera a las bentonitas terciarias localizadas en la región occidental, en el departamento Zapala, provincia del Neuquén. Los depósitos consisten en estratos lenticulares, subhorizontales, de 2 a 15 metros de espesor, la mayoría de ellos aflorantes. Están incluidos en la Formación Collón Curá, una secuencia miocena continental donde alternan tobas y areniscas. Los cuerpos de arcilla son productos de alteración de materiales piroclásticos vítreos en ambientes húmedos confinados, tales como cuerpos de agua someros. Los análisis por difracción de rayos X muestran que prevalece una esmectita dioctaédrica - montmorillonita - como único mineral arcilloso en la mayoría de los depósitos. Los minerales accesorios son cuarzo, feldespato, plagioclasa y cristobalita (ópalo-CT, y en menor proporción, ceolitas y yeso. El Na+ es el ión intercambiable dominante, junto con Ca++, Mg++ y K+. El contenido en Fe2O3 es muy alto. Estas bentonitas son buenos agentes ligantes en arenas de moldeo para fundición, pero sus propiedades reológicas y el test de filtrado no cumplen exactamente con las normas API para lodos de perforación de petróleo.

  19. Hidro conversión de heptano sobre una bentonita colombiana y una saponita española pilarizadas con aluminio y activadas con ácido

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    Manuel Fredy Molina C.

    2011-03-01

    Full Text Available El presente trabajo estudia una arcilla tipo esmectita, una bentonita colombiana, la cual fue sometida a modificación por pilarización con especies de aluminio, y a modificación por tratamiento con ácido clorhídrico de diferentes concentraciones. Igualmente, se empleó una saponita española modificada por pilarización con Al y tratada con ácido clorhídrico de diferentes concentraciones, con el objetode establecer un paralelo entre los dos tipos de arcillas en su comportamiento frente a las modificaciones estudiadas.Los sólidos fueron caracterizados por técnicas convencionales, tales como análisis químico, capacidad de intercambio catiónico, difracción de rayos X, acidez total y análisis de textura. Los resultados indican que los dos tipos dearcilla fueron igualmente pilarizados con Al, independientemente del origen de la esmectita de partida.Los resultados catalíticos en la hidroconversión de heptano, obtenidos sobre catalizadores bifuncionales (arcilla modificada impregnada con Pt revelan que la AlP-saponita es más eficiente en la isomerización que la AIP-bentonita. Esta mayor eficiencia es atribuida a la presencia de sitios ácidos fuertes tipo Si-OH ... Al, los cuales están presentes únicamente en las esmectitas, donde las sustituciones isomórficas están localizadas en las láminas tetraédricas. En montmorillonitas (bentonita, estas sustituciones se encuentran presentes en las láminas octaédricas, de manera que este tipo de sitios ácidos son reducidos o simplemente están ausentes.

  20. Seismic and Gravity Investigations of the Western Espanola Basin, Rio Grande Rift, New Mexico

    Science.gov (United States)

    Braile, L. W.; Coldren, B. G.; Baca, A.; Fontana, J.; Olheiser, M.; Ziff, M.; Keske, A.; Rhode, A.; Martin-Short, R.; Allen, W.; Denton, K. M.; Harper, C.; Baldridge, W.; Biehler, S.; Ferguson, J. F.; McPhee, D.; Snelson, C. M.

    2013-12-01

    The SAGE (Summer of Applied Geophysical Experience) program collected new seismic, gravity, electromagnetic and down-hole temperature data in 2013 in the western Espanola basin of the Rio Grande rift area of northern New Mexico. The location, about 25 km NW of Santa Fe, has been identified as a potential geothermal resources area based on relatively high temperature gradients in drill holes. The SAGE 2013 data collection was part of an integrated geophysical study of the area initiated in 2011. Seismic data consisted of a 4.8 km W to E profile (120 three-component stations in four overlapping deployments, 20 m station spacing, using a Vibroseis source - 20 m spacing for reflection VPs; 800 m spacing for refraction VPs) with both refraction and CMP reflection coverage. About 55,000 seismograms were recorded. The surface conditions (dry unconsolidated sediments) increased surface wave energy and limited the signal-to-noise level of the refraction and reflection arrivals. Utilizing longer source-receiver offsets improved the shot-gather record sections by emphasizing wider angle reflections which are very strong and coherent. The refraction data were modeled with first arrival travel time methods. The reflection data were processed to produce a CMP stacked record section. Strong reflectors from basin-filling sedimentary rocks (mostly Tertiary in age) are visible above reflections from a thin section of Paleozoic rocks and the basement. The lower reflections have an apparent dip to the west of about 12 degrees. Eighty-one new gravity measurements (detailed data at 200 m spacing along the seismic profile, and regional stations) were collected and combined with existing regional data for modeling. Interpretation of the seismic and gravity data was aided by refraction velocities, the existence of a nearby regional seismic reflection profile from industry, and lithologies and well-logs from a deep well. The sedimentary basin interpreted from the seismic and gravity data

  1. Diseño Experimental para la Caracterización de los Procesos de Hidratación de la Bentonita

    OpenAIRE

    Brú Espino, Antonio; Casero Díaz-Cano, David; Pastor Ruíz, Juan Manuel

    2001-01-01

    Presentamos el diseño experimental para el seguimiento de un proceso de hidratación de una bentonita. Se fabricaron muetras de potencias 2 cm x 12 cm x 12 cm y se introdujeron en una celda de Hele-Shaw con dos paredes de metacrilato y un marco de acero. En los experimentos de hidratación, se introduce un fluido por unos orificios del marco situados en la parte superior y en la parte inferior de la celda, con el fin de realizar experimentos de hidratación en ambos sentidos. Para tener una hidr...

  2. Mobilidade do zinco e do cobre em Argissolo com aplicação de argila bentonita Zinc and copper mobility in Argisol with application of bentonite clay

    Directory of Open Access Journals (Sweden)

    Gilvanise A. Tito

    2012-09-01

    Full Text Available A mobilidade dos metais pesados no solo é influenciada pelas características do solo, pela mineralogia das argilas e pelo teor do metal. Objetivando avaliar o efeito da bentonita na mobilidade do zinco e do cobre no solo, colunas de lixiviação preenchidas com um Argissolo foram submetidas a ensaios de mobilidade utilizando-se doses de bentonita (0, 30 e 60 t ha-1 e concentrações de zinco e cobre, de 50, 250 e 450 mg kg-1. As colunas de solo foram mantidas saturadas e sob fluxo de água permanente; em seguida foram determinados densidade, velocidade do fluxo, fator de retardamento, coeficiente de dispersão-difusão e número de Peclet. Os parâmetros de transporte foram definidos através do modelo computacional DISP. A incorporação de bentonita ao solo promoveu a retenção do zinco e do cobre pelo solo, principalmente deste último, diminuindo a concentração em solução lixiviada e os riscos de contaminação do meio ambiente. A aplicação de bentonita aumentou o fator de retardamento, mas reduziu o coeficiente de dispersão-difusão do solo.The mobility of heavy metals in the soil is influenced by the soil, the clay mineralogy and the amount of metal. Aiming to evaluate the effect of bentonite clay on zinc and copper mobility, leaching columns of soil, filled with an Argisol, utilising increasing doses of bentonite (0, 30 e 60 t ha-1 and concentrations of zinc and copper (50, 250 e 450 mg kg-1 were submitted to a saturated and steady flow. The flux density, velocity, transport retardation factor, dispersion-diffusion coefficient and breakthrough curves were obtained. The transport parameters were determined using the DISP computational model. The results allow to conclude that the application of bentonite clay to the soil promoted the retention of the zinc and copper, mainly the last one, decreasing the concentration in leachate and reducing potential contamination risks. The bentonite clay application increased the soil

  3. Propriedades térmicas de compósitos de polipropileno e bentonita organofílica

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    Elaine V. D. G. Líbano

    2012-01-01

    Full Text Available Uma argila bentonita policatiônica nacional foi utilizada para a produção de uma argila organofílica, obtida a partir da síntese com o sal de amônio quaternário, cloreto de cetiltrimetilamônio. A argila tratada com o sal orgânico (BENT-org e a não tratada (BENT foram caracterizadas por espectroscopia de absorção no infravermelho (FTIR e difratometria de raios X (DRX. Posteriormente, as argilas foram misturadas com o polipropileno (PP pelo método de intercalação por fusão em uma extrusora dupla-rosca co-rotativa. Os compósitos foram caracterizados pelas técnicas de DRX, calorimetria diferencial de varredura (DSC e análise termogravimétrica (TGA. Os resultados de FTIR e DRX mostraram a presença dos grupos característicos do sal de amônio e a intercalação deste entre as camadas do argilomineral. As análises de DRX dos compósitos com 3 e 5% em massa de BENT-org evidenciaram a presença de picos deslocados para regiões de baixo ângulo, sugerindo a intercalação das cadeias do polímero entre as camadas da argila. Os resultados de DSC indicaram que a argila pode ter atuado como agente nucleante devido ao aumento na Tcc (temperatura de cristalização no resfriamento dos compósitos. De acordo com os resultados de TG, constatou-se que a incorporação da argila ao PP melhorou a estabilidade térmica do polímero nos compósitos com 5% em massa de BENT e 3 e 5% em massa de BENT-org.

  4. Quality assurance programme in mammography of the Sociedad Espanola de Diagnosticos por Imagen de la Mama (SEDIM)

    International Nuclear Information System (INIS)

    The European Union Council Directive 97/43/Euratom of 30 June 1997 on health protection of individuals against the dangers of ionizing radiation in relation to medical exposure has been partially transposed to the Spanish national law by the Real Decreto 1976/1999, which establishes the quality criteria in Diagnostic Radiology. A key instrument in this legal regulation is the so-called Quality Assurance Program (QAP) which has to be implemented in each Diagnostic Radiology unit. The Spanish Breast Imaging Diagnostic Society (Sociedad Espanola de Diagnostico por Imagen de la Mama, SEDIM) has proposed a reference QAP to be used as a guide in all the mammography units in the country. Its main issues are displayed in the present paper. The SEDIM QAP includes some items related to justification and optimization of mammography exams as well as a proposal for the assignment of functions and responsibilities. A guide for the image and technical parameters quality evaluation is also included. Some keys on equipment acquisition, maintenance and on continuing education and information management can also be found in that document. (author)

  5. Caracterização e usos de argilas bentonitas e vermiculitas para adsorção de cobre (II) em solução

    OpenAIRE

    Santos C. P. F. dos; Melo D. M. A.; Melo M. A. F.; V. Sobrinho E.

    2002-01-01

    Vários trabalhos tratam da remoção de metais por argilas e argilominerais. O processo de remoção geralmente ocorre por precipitação, troca iônica e adsorção. Neste trabalho estudou-se a adsorção de solução de Cu (II) em vermiculita, bentonitas sódica e cálcica, proveniente de Campina Grande-PB , tendo-se como variáveis pH, tempo de contato e concentração do adsorvente. Os ensaios foram realizados à temperatura ambiente e as medidas de Absorção Atômica foram feitas no sobrenadante e no resíduo...

  6. INFLUÊNCIA DA TEMPERATURA NA REOLOGIA DE FLUIDOS DE PERFURAÇÃO PREPARADOS COM CARBOXIMETILCELULOSE, GOMA XANTANA E BENTONITA

    Directory of Open Access Journals (Sweden)

    Klismeryane Costa de Melo

    2013-10-01

    Full Text Available O comportamento reológico dos fluidos de perfuração pode sofrer alterações ao longo da perfuração em função do gradiente de temperatura do poço. A degradação térmica sofrida por alguns aditivos utilizados como viscosificantes restringe a utilização da classe dependendo da temperatura a qual será exposto. Este trabalho apresenta um estudo sobre o comportamento reológico da Goma Xantana (GX, da Carboximetilcelulose (CMC e da Bentonita (BNT em função da temperatura. Os Modelos matemáticos de Ostwald de Waale e o de Herschel-Bulkley foram aplicados para determinar os parâmetros reológicos. O efeito da hidratação dos polímeros e da argila na reologia de soluções aquosas foram previamente estudados. A caracterização reológica foi realizada através de ensaios de reologia, utilizando sistema de cilindros coaxiais, para obtenção das curvas de fluxo. A reologia foi avaliada em função da temperatura para cada um dos aditivos utilizados. Os resultados mostraram que a CMC se solubiliza rapidamente em água, porém apresenta maior degradação quando exposta a temperatura mais elevada. A GX se mostrou apta para ser utilizada em formulações de fluidos que serão usados em poços com gradiente de temperatura mais elevados. A bentonita não apresentou alterações no comportamento reológico em função do gradiente de temperatura estudado.

  7. Rio Arriba County Strategy To Combat Heroin Addiction. Hearing before a Subcommittee of the Committee on Appropriations, United States Senate, One Hundred Sixth Congress, First Session. Special Hearing (Espanola, New Mexico, March 30, 1999).

    Science.gov (United States)

    Congress of the U.S., Washington, DC. Senate Committee on Appropriations.

    At an Espanola (New Mexico) hearing, the Subcommittee on Commerce, Justice, and State, the Judiciary, and Related Agencies of the Senate Committee on Appropriations heard testimony on heroin addiction and intervention efforts in Rio Arriba County, New Mexico. An opening statement of Senator Pete Domenici outlined the problem of an epidemic of…

  8. Caracterización de bentonitas y zeolitas sin tratamiento como refuerzo en materiales compuestos de matriz polimérica//Characterization of untreated zeolites and bentonites as reinforcement in polymer matrix composites

    Directory of Open Access Journals (Sweden)

    Francisco Jesús Mondelo‐García

    2014-01-01

    Full Text Available Las bentonitas con microestructuras compuestas de placas silicio aluminosas. Se logró el objetivo de caracterizar las bentonitas sódicas de Wyoming, USA, Patagonia de Argentina, nordeste de Brasil, así como las bentonitas policatiónicas de Brasil, la cálcica activada con sodio y zeolita de Cuba no organofilizadas para emplearlas como refuerzo en materiales compuestos de matriz polimérica. Estosmateriales se evaluaron usando técnicas físico-químicas como fluorescencia de rayos X, difracción de rayos X, microscopia electrónica de barrido, humedad, capacidad de intercambio catiónico, absorción e hinchabilidad en diluyente acuoso. Los resultados confirmaron rangos variables de intercambio catiónico,hinchamiento y absorciòn en agua entre las bentonitas analizadas, debido a su naturaleza química estructural en hidratación, logrando mayores valores las sódicas, luego la cálcica activada y con menor valor las policatiónicas, pero permiten usarlas como carga en polímeros.Palabras claves: bentonita, zeolita, matriz polimérica, organofilizada, materiales compuestos._____________________________________________________________________________AbstractBentonites with aluminous silicon microstructure composed of plates. The work accomplished to characterize the sodium bentonites in Wyoming USA, Patagonia Argentina, Northeast Brazil and the Brazilian polycationic bentonites, calcium-activated sodium zeolite from Cuba without organic modificationnot organophilized to employ as reinforcing in composite materials of polymer matrix. These materials were evaluated for physical and chemical assay techniques such as X-ray fluorescence, X-ray diffraction, scanning electron microscopy, moisture, cation exchange capacity, absorption and swelling aqueousdiluent. The results confirmed variables ranges of cationic exchange, swelling and water absorption from the bentonites tested, due to its chemical-structural hydration, achieving higher values nature

  9. Cadmium and copper adsorption on bentonite: effects of pH and particle size Adsorção de cádmio e cobre em bentonita: efeito do pH e da granulometria

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    Lúcia Helena Garófalo Chaves

    2011-06-01

    Full Text Available Reactions of heavy metals with clay minerals are important in determining metal fates in the environment. However, the adsorption process of these metals by the bentonite has been extensively investigated. The objectives of this work were to assess the ability of bentonite clay to adsorb cadmium and copper and to study the effects of pH and particle size upon these metals adsorption. Adsorption isotherms were obtained from batch adsorption experiments, with increasing cadmium and copper concentrations (5-200 mg L-1. To find out the effects of pH and particle size on adsorption, the experiments were conducted at pH 4; 5 and 6 using particles sizes of As reações dos metais pesados com os minerais de argila são importantes para determinar o destino dos mesmos no meio ambiente. Assim, o processo de adsorção destes metais pela bentonita tem sido muito investigado. Objetivou-se com este trabalho avaliar a capacidade da argila bentonita em adsorver cádmio e cobre e os efeitos do pH e de sua granulometria na adsorção dos mesmos. A partir de experimentos tipo "batch", foram elaboradas isotermas de adsorção com quantidades crescentes de Cd e Cu (5-200 mg L-1. Para determinar o efeito do pH e da granulometria sobre a adsorção, os experimentos foram conduzidos a pH 4; 5 e 6, utilizando bentonita com granulometria < 0,5 mm e entre 0,5 a 2,0 mm. As quantidades de Cd e Cu adsorvidas pela bentonita foram determinadas pela diferença entre as concentrações inicial e final dos elementos na solução de equilíbrio. A bentonita adsorveu mais Cu do que Cd, entretanto a adsorção dos dois metais aumentaram com o aumento do pH independentemente da granulometria. Nenhum efeito da granulometria sobre a adsorção foi observada. Os dados experimentais foram bem ajustados ao modelo de Langmuir. A capacidade máxima de adsorção diminuiu e a energia de ligação aumentou em função do aumento do pH.

  10. Adição de bentonita sódica como adsorvente de aflatoxinas em rações de frangos de corte Utilization of sodium bentonite as adsorbent of aflatoxins in broiler feed

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    Juarez Morbini Lopes

    2006-10-01

    Full Text Available A presença de micotoxinas nas matérias-primas, principalmente no milho utilizado para rações para aves, é uma das maiores preocupações atuais devido aos danos causados por essa substâmcia não só aos animais, mas também aos produtores e às empresas do setor avícola. Considerando a utilização de adsorvente ou seqüestrante na ração para minimizar os efeitos deletérios, realizou-se um experimento para avaliar o efeito da adição de um adsorvente, baseado em bentonita sódica, na ração de frangos de corte, a fim de reduzir os efeitos de aflatoxinas. Foram utilizados 960 pintos Cobb de um dia de idade, distribuídos em oito repetições de 20 animais nos tratamentos: T1=sem aflatoxina;T2=3mg kg-1 de aflatoxina;T3=sem aflatoxina+0,5% de bentonita; T4=3mg kg-1 de aflatoxina+0,1% de bentonita; T5=3mg kg-1 de aflatoxina+0,3% de bentonita e T6=3mg kg-1 de aflatoxina+0,5% de bentonita. O consumo alimentar, o peso corporal e a conversão alimentar foram afetados pela presença da toxina na ração. A adição de bentonita sódica na ração sem aflatoxina não causou nenhum efeito depressivo nas aves. Nos tratamentos que continham 3mg kg-1 de aflatoxinas, a adição do adsorvente promoveu um melhor desempenho das aves, sendo que 0,3% de adição de bentonita apresentou melhores resultados.High concentrations of micotoxins in raw materials, mainly in corn used in poultry rations of food, is an important subject of study due to hazardous problems not only to the animals themselves but also to the producer and to the poultry industry due to the reduction of performance by aflatoxins. Taking into account the lack of efficient tecnique for its elimination, from the feed, an adsorbent was added to the diets in order to reduce the effects of aflatoxins. Nine hundred sixty day old Cobb chicks, distributed in 8 replicates of 20 birds per pen the following treatments: T1=No aflatoxin; T2=3mg kg-1 of aflatoxin; T3=no aflatoxin+0.5% of bentonite; T

  11. Caracterización física con difractogramas e hinchamiento de bentonitas organofílicas para adicionar a materiales compuestos poliméricos//Physical characterization with difractograms and swelling of organophilic bentonites to add to polymer composites

    OpenAIRE

    Francisco Jesús Mondelo‐García; Francisco Jesús‐Almeida; Flavio Manuel‐Sousa; José Luís Valín‐Rivera; María Grasa da‐Silva‐Valenzuela; Francisco Rolando Valenzuela‐Díaz

    2014-01-01

    Las bentonitas con partículas de microestructura combinada por placas de tetraedros y octaedros silicio-aluminosos, contienen cavidades interlaminares entre ellas, confiriéndoles cualidades positivas para usarse en tintas, medicamentos, fluidos de perforación, retener desechos contaminantes residuales y como refuerzos de polímeros. Se logró el objetivo de hidratar y modificar orgánicamentecon sal cuaternaria orgánica del tipo cloruro hexadecil trimetil amonio y sal de sodio a bentonitas sódic...

  12. SINTESIS Y CARACTERIZACIÓN DE BENTONITA MODIFICADA CON ESPECIES DE TiO2 y Fe-TiO2 OBTENIDAS DEL MINERAL ILMENITA

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    Juan Torres

    2014-07-01

    Full Text Available Se sintetizó una serie de sólidos nanoestructurados, obtenidos por la intercalación de nanopartículas de TiO2 y Fe-TiO2 en los espacios interlaminares de un mineral de arcilla esmectítico. Los nuevos materiales se prepararon mediante la modificación simultánea de dos minerales naturales: una bentonita y una ilmenita. Los materiales obtenidos se caracterizaron por fluorescencia de rayos X (FRX, espectroscopía infrarroja (IR, difracción de rayos X (DRX, microscopía electrónica de barrido (SEM y sortometría de nitrógeno. Los resultados del análisis químico (FRX confirmaron claramente la incorporación de titanio y de hierro en los materiales sintetizados. Los análisis por DRX, SEM y sortometría de nitrógeno verificaron la modificación del mineral de arcilla por incorporación de especies de dióxido de titanio, demostrando la generación de estructuras mesoporosas delaminadas o exfoliadas con incremento en los valores de área superficial y porosidad controlada.

  13. Efeito de sais quaternários de amônio na organofilização de uma argila bentonita nacional Effect of quaternary ammonium salts on the organophilization of national bentonite clay

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    R. Barbosa

    2006-12-01

    Full Text Available A bentonita, composta predominantemente pelo argilomineral montmorilonita que lhe confere as propriedades físicas concentra a maior parte das reservas nacionais (62% no Estado da Paraíba. A transformação da bentonita em argila organofílica consiste em um procedimento laboratorial simples e pode ser realizada através de reação de troca dos cátions (Na+ ou Ca2+ presentes na superfície e no espaço interlamelar dos argilominerais, por cátions de sais quaternários de amônio. Neste trabalho as bentonitas organofílicas foram preparadas utilizando quatro tipos diferentes de sais quaternários de amônio, tais como: cloreto de alquil dimetil benzil amônio (Dodigen, cloreto de estearil dimetil amônio (Praepagen, cloreto de cetil trimetil amônio (Genamin e brometo de cetil trimetil amônio (Cetremide. As argilas organofilizadas foram caracterizadas por termogravimetria, difração de raios X, análise química e por fluorescência de raios X. Os resultados confirmaram a incorporação dos sais quaternários de amônio na estrutura da argila e mostraram que dois dos quatro sais quaternários utilizados, o Praepagen e o Cetremide apresentaram uma faixa maior de estabilidade térmica.Bentonite clay, mainly composed by montmorillonite that provides the physical properties, concentrates the majority of the national reserve (62% in the Paraíba State. The transformation of bentonite clay to organoclay is made with a simple laboratory procedure and this modification can be obtained by cation (Na+ or Ca2+ exchange reaction that are present on the surface and in the interlayer space of the mineral clays by quaternary ammonium salts. In this, the organoclays bentonite were preparedwith four different types of quaternary ammonium salts such as alkyldimethylbenzylammonium chloride (Dodigen, esthearildimethylammonium chloride (Praepagen, cethyltrimethylammonium chloride (Genamin and cethyltrimethylammonium bromide (Cetremide. The organoclays were

  14. Misturas de um solo laterítico com cimento e bentonita para uso em cortinas verticais Mixtures of a lateritic soil with cement and bentonite for slurry wall purposes

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    Priscila Batista

    2010-06-01

    Full Text Available É crescente mundo afora o uso de cortinas verticais para contenção da contaminação em água subterrânea. Os solos lateríticos, pela sua ampla distribuição no Brasil, possuem grande potencial de aplicação nessas obras. Entretanto algumas questões ainda carecem de maior investigação, como a interação e compatibilidade desses solos com a bentonita e o cimento, principais aditivos usados para melhorar as propriedades das cortinas. O presente artigo avalia propriedades de um solo laterítico e suas misturas com bentonita e cimento, incluindo a investigação de parâmetros geotécnicos mecânicos e hidráulicos. A campanha laboratorial consistiu de ensaios de caracterização física, físico-química e mineralógica, de condutividade hidráulica, de compressão simples e de cisalhamento direto. Os resultados demonstram que a adição de 3% de bentonita em amostras compactadas não trouxe a diminuição esperada da condutividade hidráulica do solo laterítico, ainda que tenha proporcionado um considerável incremento na resistência ao cisalhamento da mistura.There is an increasing worldwide demand for slurry walls to contain contaminated groundwater. Lateritic soils, due to their wide distribution in the Brazilian territory, have great potential to be used in these cases. However, some issues remain uncertain and need investigation, including the interaction and compatibility of these soils with bentonite or cement, the most used additives to improve their geotechnical properties. This work evaluates some mechanical and hydraulic properties of a lateritic soil sample and its mixtures with bentonite and cement. The laboratorial procedures consisted of physical, physico-chemical and mineralogical characterization, hydraulic conductivity, uniaxial compression and direct shearing testing. The results demonstrate that the addition of 3% of bentonite in compacted samples did not decrease the hydraulic conductivity of the lateric soil as

  15. Propriedades térmicas de compósitos de polipropileno e bentonita organofílica Thermal properties of polypropylene and organophilic bentonite

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    Elaine V. D. G. Líbano

    2012-01-01

    Full Text Available Uma argila bentonita policatiônica nacional foi utilizada para a produção de uma argila organofílica, obtida a partir da síntese com o sal de amônio quaternário, cloreto de cetiltrimetilamônio. A argila tratada com o sal orgânico (BENT-org e a não tratada (BENT foram caracterizadas por espectroscopia de absorção no infravermelho (FTIR e difratometria de raios X (DRX. Posteriormente, as argilas foram misturadas com o polipropileno (PP pelo método de intercalação por fusão em uma extrusora dupla-rosca co-rotativa. Os compósitos foram caracterizados pelas técnicas de DRX, calorimetria diferencial de varredura (DSC e análise termogravimétrica (TGA. Os resultados de FTIR e DRX mostraram a presença dos grupos característicos do sal de amônio e a intercalação deste entre as camadas do argilomineral. As análises de DRX dos compósitos com 3 e 5% em massa de BENT-org evidenciaram a presença de picos deslocados para regiões de baixo ângulo, sugerindo a intercalação das cadeias do polímero entre as camadas da argila. Os resultados de DSC indicaram que a argila pode ter atuado como agente nucleante devido ao aumento na Tcc (temperatura de cristalização no resfriamento dos compósitos. De acordo com os resultados de TG, constatou-se que a incorporação da argila ao PP melhorou a estabilidade térmica do polímero nos compósitos com 5% em massa de BENT e 3 e 5% em massa de BENT-org.A Brazilian polycationic bentonite clay was used for producing an organophilic clay with the quaternary ammonium salt, cetyltrimethylammonium chloride. The salt treated clay (BENT-org and untreated clay (BENT were characterized by infrared spectroscopy (FTIR and X-ray diffraction (XRD. Then, each clay was mixed with polypropylene (PP by melt intercalation in a counter-rotating twin-screw extruder. The composites were characterized by XRD, differential scanning calorimetry (DSC and thermogravimetric analysis (TGA. The results from FTIR and XRD

  16. Los depósitos de bentonita de Barda Negra y cerro Bandera, departamento Zapala, provincia del Neuquén, Argentina Bentonite deposits of Barda Negra and Cerro Bandera, Zapala Department, Neuquén Province, Argentina

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    A. Impiccini

    2002-09-01

    Full Text Available Las bentonitas de la región nordpatagónica pueden ser agrupadas en dos distritos mineralogenéticos caracterizados desde el punto de vista geológico, geográfico y estratigráfico. En este trabajo se considera a las bentonitas terciarias localizadas en la región occidental, en el departamento Zapala, provincia del Neuquén. Los depósitos consisten en estratos lenticulares, subhorizontales, de 2 a 15 metros de espesor, la mayoría de ellos aflorantes. Están incluidos en la Formación Collón Curá, una secuencia miocena continental donde alternan tobas y areniscas. Los cuerpos de arcilla son productos de alteración de materiales piroclásticos vítreos en ambientes húmedos confinados, tales como cuerpos de agua someros. Los análisis por difracción de rayos X muestran que prevalece una esmectita dioctaédrica - montmorillonita - como único mineral arcilloso en la mayoría de los depósitos. Los minerales accesorios son cuarzo, feldespato, plagioclasa y cristobalita (ópalo-CT, y en menor proporción, ceolitas y yeso. El Na+ es el ión intercambiable dominante, junto con Ca++, Mg++ y K+. El contenido en Fe2O3 es muy alto. Estas bentonitas son buenos agentes ligantes en arenas de moldeo para fundición, pero sus propiedades reológicas y el test de filtrado no cumplen exactamente con las normas API para lodos de perforación de petróleo.Bentonites from the North Patagonia region can be grouped in two mineralogenic districts distinguishable on geological, geographical, and stratigraphical criteria. In this paper, we consider the Tertiary bentonites located in the western region, Zapala Department, Neuquén Province. The deposits occur in sub-horizontal lenticular beds, 2 to 15 m in thickness, most of which crop out at the surface. They lie within the Collón Curá Formation, a Miocene continental sequence of alternating tuffs and sandstones. The clay bodies are alteration products of pyroclastic glassy materials in confined wet

  17. Uso de bentonita na remediação de solos contaminados com zinco: efeito na produção de feijão Use of bentonite in the remediation of soils contaminated with zinc: effect on bean production

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    Gilvanise A. Tito

    2011-09-01

    Full Text Available Diversos procedimentos têm sido propostos para reduzir a concentração de metais pesados nos solos, e, conseqüentemente, seus efeitos poluidores. Dentre eles destacam-se a aplicação de materiais, como a bentonita, capazes de adsorver estes elementos, tornando-os menos disponíveis para as plantas. Objetivou-se com este trabalho avaliar a capacidade da bentonita na remediação de solos contaminados com zinco. Conduziu-se experimento em condições de casa de vegetação com delineamento inteiramente casualizado com três repetições e uma planta por parcela, utilizando-se como planta indicadora o feijão caupi (Vigna unguiculata L.. Os tratamentos consistiram de uma combinação fatorial 3 x 3, sendo o primeiro fator composto por três doses de Zn (50, 250 e 450 mg kg-1 e o segundo fator por três doses de bentonita (0, 30 e 60 t ha-1. Para o estudo, utilizou-se vasos com capacidade de18 kg, preenchidos com 15 kg de solo em mistura com as respectivas doses de bentonita e com o zinco. Os tratamentos permaneceram incubados por um período de 10 dias, e em seguida foi realizada a semeadura da planta indicadora. Aos 65 dias após a semeadura colheram-se folhas, caules, raízes, sementes e casca, que, depois de secos em estufa de circulação de ar (65°C, foram pesados, moídos e analisados quanto aos teores de zinco. Os resultados evidenciaram que a bentonita parece ser um excelente material inorgânico para remediar solos contaminados com zinco. A incorporação de bentonita ao solo aumenta a adsorção do zinco diminuindo a disponibilidade deste elemento para a planta tendendo, consequentemente, aumentar a produção de massa seca.Several procedures have been proposed to reduce the concentration of heavy metals in soils and consequently, to reduce polluting effects. One of the most used procedures is the application of materials such as bentonite capable of adsorbing these elements making them less available to plants. The objective of this

  18. Caracterización física con difractogramas e hinchamiento de bentonitas organofílicas para adicionar a materiales compuestos poliméricos//Physical characterization with difractograms and swelling of organophilic bentonites to add to polymer composites

    Directory of Open Access Journals (Sweden)

    Francisco Jesús Mondelo‐García

    2014-05-01

    Full Text Available Las bentonitas con partículas de microestructura combinada por placas de tetraedros y octaedros silicio-aluminosos, contienen cavidades interlaminares entre ellas, confiriéndoles cualidades positivas para usarse en tintas, medicamentos, fluidos de perforación, retener desechos contaminantes residuales y como refuerzos de polímeros. Se logró el objetivo de hidratar y modificar orgánicamentecon sal cuaternaria orgánica del tipo cloruro hexadecil trimetil amonio y sal de sodio a bentonitas sódicas del Nordeste brasileño y la Patagonia argentina, policatiónicas brasileñas, cálcica activada y zeolita ambas cubanas, estableciendo una caracterización entre muestras no tratadas y organofilizadas. Estos materiales se evaluaron comparativamente por difracción de rayos X ehinchamiento Foster en diluyentes orgánicos. Los resultados confirmaron una variación significativa fisicoquímica y microestructural en los difractogramas de las bentonitas organofílicas, mientras las partículas micrométricas tomaron dimensiones nanométricas, se incrementó mucho más el hinchamiento en estas, mejorando su efectividad de empleo, al emplearlas como refuerzo,adicionado a una matriz polimérica.Palabras claves: bentonita, organofílica, zeolita, hinchamiento Foster, matriz polimérica.______________________________________________________________________________AbstractThe bentonites with microstructure particles combined by plates tetrahedral and octahedral siliconaluminous contain interlaminares cavities including, conferring positive qualities for use in inks, medicines, drilling fluids; retain polluting waste residuals and as polymer reinforcements. The objective to hydrate and organically modified with organic quaternary salt of hexadecyl trimethyl ammonium chloride type and sodium salt the sodium bentonites Northeast Brazilian and PatagoniaArgentina, Brazilian polycationics, calcium activated and zeolite both Cuban, establishing a characterization

  19. Cervantes y su intertextualidad espanola

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    Alberto Blecua

    2013-12-01

    Full Text Available In this article I aim to investigate all the paraphrastic or literal allusions to Spanish texts in Cervantes's output. I leave to theorists of intertextuality the task of distinguishing among quotations, allusions, plagiarism and other palimpsest types. I omit – except for brief introductions – structural models such as chivalric romances, pastoral and picaresque novels, and Italian novellas. I have used, above all, the notes in the editions mentioned here, and followed the chronology of Cervantes's works.

  20. Cervantes y su intertextualidad espanola

    OpenAIRE

    Alberto Blecua

    2013-01-01

    In this article I aim to investigate all the paraphrastic or literal allusions to Spanish texts in Cervantes's output. I leave to theorists of intertextuality the task of distinguishing among quotations, allusions, plagiarism and other palimpsest types. I omit – except for brief introductions – structural models such as chivalric romances, pastoral and picaresque novels, and Italian novellas. I have used, above all, the notes in the editions mentioned here, and followed the chronology of Cerv...

  1. Ocorrência de uma nova bentonita brasileira nos basaltos intemperizados da formação Mosquito, bacia do Parnaíba, sul do Maranhão Occurrence of a new brazilian bentonite in the weathered basalts of the Mosquito formation, Parnaíba basin, southern Maranhão, Brazil

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    S. P. A. Paz

    2011-12-01

    Full Text Available No município de Formosa da Serra Negra, sul do Maranhão, às margens da rodovia MA006, encontram-se afloramentos de basaltos intemperizados da Formação Mosquito, apresentando textura bastante argilosa e potencial de ser um material bentonítico. Neste trabalho, esse material que vem sendo considerado uma nova ocorrência de bentonita no Brasil e, batizado de Formosa, foi caracterizado por difração de raios X, fluorescência de raios X, microscopia eletrônica de varredura, espectroscopia Mössbauer e capacidade de troca catiônica, em amostra total e após separação granulométrica, e ainda, comparada com duas das principais bentonitas brasileiras, Chocolate e Bofe. Apesar das variações químicas e mineralógicas encontradas, muito comuns nesse tipo de argila, as semelhanças observadas convencem o promissor uso da argila Formosa como bentonita, uma vez que o ponto principal da caracterização está na presença dominante de montmorillonita e baixa concentração de outras fases minerais, mostrando que esse material apresenta mineralogia importante do ponto de vista tecnológico.Extensive weathered basalt outcrops can be found in the vicinities of the Formosa da Serra Negra town, southern of Maranhão state, northern Brazil. They exhibit typical clay texture and an enormous potential to be used and explored as bentonite. This work deals with the chemical and mineralogical characterization of this material that has been named as Formosa Bentonite. The main following methods and analytical techniques were used: XRD, XRF, SEM, Mössbauer spectroscopy and CEC in total sample and after grain size separation. Two samples from the main Brazilian "Paraíba bentonites" (Chocolate and Bofe types were used for comparison purposes. The results show that the Formosa bentonite exhibit some chemical and mineralogical differences in comparison with the two reference samples, although the main and most important feature is the presence of

  2. Phytomass of beans and grain production as affected by zinc, copper and cadmium doses and bentonite application Fitomassa e produção do feijão afetadas pelas doses de zinco, cobre e cádmio e aplicação de bentonita

    Directory of Open Access Journals (Sweden)

    Gilvanise A. Tito

    2011-07-01

    Full Text Available The objective of this study was to determine the effect of zinc, copper and cadmium on phytomass and grain production and to evaluate indirectly the adsorbent effect of bentonite clay by determining the accumulation of these heavy metals in bean plants. The study consisted of three separate experiments (one for each cation with the application of three doses of bentonite (0, 30 and 60 t ha-1 in pots containing separately 50 mg of Zn; Cu and Cd kg-1 of soil, with three replicates. Thus, each experiment consisted of 9 experimental units. In each one, a bean plant was cultivated and after 65 days, samples of leaves, stems, roots and grains were collected. Afterwards, the samples were dried, weighed, grinded and the concentrations of Zn, Cu and Cd were determined. The phytomass of leaves of the plant growing on the soil with Zn, the Zn concentration in the whole plant and the Cd concentration in the leaves, stem and grains were significantly influenced by the bentonite application. Zn and Cd concentration in leaves, stem and grains decreased with the application of bentonite, indicating a positive effect of the clay application to the soil on the adsorption of these metals, decreasing the availability for plants. Zn was the most accumulated element in the plant, followed by Cd and Cu. The Zn, Cu and Cd accumulation in the plant obeyed the following sequence: stem > leaves > grains > roots; roots > stem > grains > leaves; roots > stem > leaves > grains, respectively.Objetivou-se, com este trabalho, estudar o efeito do cobre, zinco e cádmio em fitomassa e produção de grãos e avaliar indiretamente o efeito adsorvente da argila bentonita, determinando o acúmulo de metais pesados em plantas de feijão. O estudo consistiu de três experimentos separados (um para cada cátion, com a aplicação de três doses de bentonita (0, 30 e 60 t ha-1 em vasos contendo, separadamente, 50 mg de Zn, 50 mg de Cu e 50 mg de Cd kg-1 de solo, com três repeti

  3. Desenvolvimento de fluidos aquosos com bentonita para perfuração de poços de petróleo onshore Development of aqueous fluids with bentonite clay for drilling of onshore oil wells

    Directory of Open Access Journals (Sweden)

    R. C. A. M Nascimento

    2010-06-01

    Full Text Available Devido aos grandes desafios encontrados na perfuração de poços, há a necessidade de se desenvolver fluidos com propriedades adequadas e capazes de atender todas as exigências da perfuração, como elevada capacidade de carreamento de sólidos e alta lubricidade, como também fluidos ambientalmente corretos. O grau de impacto dos fluidos de perfuração no meio ambiente depende especialmente do tipo de fluido utilizado, se de base aquosa, oleosa, sintética ou mesmo de base ar. Portanto, é de fundamental importância o desenvolvimento de fluidos com características específicas em cada etapa da perfuração. Sendo assim, este trabalho objetivou o desenvolvimento de fluidos aquosos, com baixo teor de sólidos e propriedades reológicas, de filtração e lubricidade adequadas à perfuração de poços de petróleo onshore. Os fluidos foram formulados utilizando em sua composição bentonita sódica industrializada, aditivos poliméricos e lubrificantes, em diferentes concentrações. O estudo reológico, de filtração e lubricidade mostrou que os fluidos apresentam comportamento pseudoplástico e que os aditivos selecionados desempenham com êxito suas funções de modificadores reológicos, redutores de filtrado e agente lubrificante. Além disto, ficou evidenciada a necessidade de aditivos lubrificantes em fluidos aquosos contendo argila bentonítica e polímeros. A adição de 1% de lubrificante no fluido é suficiente para adequar a capacidade lubrificante dos fluidos.Due to challenges encountered in drilling wells, there is a need to develop fluids that have properties suitable and able to meet all the requirements of drilling, such as, high capacity for carrying of solid and high lubricity. Besides that, they need to be environmentally friend. The degree of impact of drilling fluids in the environment depends on the type of fluid used, if water or oil or synthetic or air based. It is therefore of fundamental importance to develop

  4. Utilização do planejamento experimental no estudo do efeito da composição de misturas de bentonitas na reologia de fluidos de perfuração. Parte II: composições ternárias Experimental design applied to the study of composition effect of bentonite on the rheology of drilling fluids. Part II: ternary compositions

    Directory of Open Access Journals (Sweden)

    L. F. A. Campos

    2007-03-01

    Full Text Available O objetivo deste trabalho foi utilizar o planejamento experimental para avaliar o efeito da composição de misturas ternárias de bentonitas na reologia de fluidos de perfuração de poços de petróleo. Por meio do planejamento foram determinadas as proporções dos componentes nas misturas ternárias das argilas e então ajustados modelos de regressão relacionando viscosidade aparente, viscosidade plástica e volume de filtrado com a proporção de cada argila. A aplicação da modelagem de misturas, incluindo composições ternárias, aliada a metodologia de superfícies de resposta e otimização matemática e gráfica permitiu delimitar uma gama de composições de argilas que favorece a melhoria das propriedades reológicas e de filtração dos fluidos estudados.The purpose of this work was to study of composition effect of ternary bentonite mixtures on the rheology of drilling fluids. Through the experimental design were defined the components proportions in the ternary clays mixtures and then adjusted regression models relating apparent and plastic viscosities and water loss, with the proportion of each clay. The application of mixture experimental design, include ternary composition, response surface methodology, graphic and mathematical optimization allowed to delimit a strip of compositions that favors the improvement of the rheological properties of the drilling fluids.

  5. Influência da concentração e purificação da argila na estrutura e permeação ao vapor de água de nanocompósitos PEBDL/bentonita Effect of loading level and clay purification on the structure and water vapor permeability of LLDPE/bentonite nanocomposites

    Directory of Open Access Journals (Sweden)

    Eduardo M. Silva

    2012-01-01

    Full Text Available Este trabalho tem por objetivo a preparação, caracterização e avaliação da permeabilidade ao vapor de água de filmes nanocompósitos poliméricos. Um polietileno linear de baixa densidade linear (PEBDL foi utilizado como matriz e uma argila bentonita Paraibana na sua forma natural, purificada e organofilizada foi adicionada à matriz em concentrações de 1 a 2% em massa. As argilas e os nanocompósitos foram caracterizados por espectroscopia no infravermelho (FTIR e por difração de raios x (DRX. A permeação ao vapor de água dos filmes foi determinada em função do teor e modificação da carga mineral. Os resultados mostram que a purificação (remoção de matéria orgânica e que a organofilização da carga foram eficientes e que nanocompósitos com morfologia intercalada foram obtidos em todos os casos. A presença de carga aumentou significativamente a permeabilidade dos filmes ao vapor de água, mas os efeitos da purificação e/ou organofilização da argila, bem como do teor de carga, nesta propriedade, foram discretos.This work is concerned with the preparation, characterization and measurement of water vapor permeability of LLDPE/bentonite nanocomposite films, containing 1% and 2% of natural, purified, and organophilized clay. FTIR and XRD techniques were used to characterize the clay and the composites. The results pointed to an effective clay purification procedure (removal of organic matter. Mostly intercalated nanocomposites were obtained in all cases. The addition of clay significantly increased the permeability of the films to water vapor. However, purification and/or organophilization of the clay, as well as loading level, were found to have little effect on the permeability.

  6. Influência da concentração e purificação da argila na estrutura e permeação ao vapor de água de nanocompósitos PEBDL/bentonita Effect of loading level and clay purification on the structure and water vapor permeability of LLDPE/bentonite nanocomposites

    Directory of Open Access Journals (Sweden)

    Eduardo M. Silva

    2013-01-01

    Full Text Available Este trabalho tem por objetivo a preparação, caracterização e avaliação da permeabilidade ao vapor de água de filmes nanocompósitos poliméricos. Um polietileno linear de baixa densidade linear (PEBDL foi utilizado como matriz e uma argila bentonita Paraibana na sua forma natural, purificada e organofilizada foi adicionada à matriz em concentrações de 1 a 2% em massa. As argilas e os nanocompósitos foram caracterizados por espectroscopia no infravermelho (FTIR e por difração de raios x (DRX. A permeação ao vapor de água dos filmes foi determinada em função do teor e modificação da carga mineral. Os resultados mostram que a purificação (remoção de matéria orgânica e que a organofilização da carga foram eficientes e que nanocompósitos com morfologia intercalada foram obtidos em todos os casos. A presença de carga aumentou significativamente a permeabilidade dos filmes ao vapor de água, mas os efeitos da purificação e/ou organofilização da argila, bem como do teor de carga, nesta propriedade, foram discretos.This work is concerned with the preparation, characterization and measurement of water vapor permeability of LLDPE/bentonite nanocomposite films, containing 1% and 2% of natural, purified, and organophilized clay. FTIR and XRD techniques were used to characterize the clay and the composites. The results pointed to an effective clay purification procedure (removal of organic matter. Mostly intercalated nanocomposites were obtained in all cases. The addition of clay significantly increased the permeability of the films to water vapor. However, purification and/or organophilization of the clay, as well as loading level, were found to have little effect on the permeability.

  7. Nanocompósitos de polietileno/argila bentonita nacional: influência da argila e do agente compatibilizante PE-g-MA nas propriedades mecânicas e de inflamabilidade Polyethylene/national bentonite clay nanocomposites: influence of clay and PE-g-MA coupling agent on the mechanical properties and flammability

    Directory of Open Access Journals (Sweden)

    Gustavo F. Brito

    2008-06-01

    Full Text Available Nanocompósitos de polietileno de alta densidade/argila bentonita nacional foram preparados por intercalação por fusão. A influência da adição da argila sem tratamento e da argila tratada com o sal quaternário de amônio Cetremide e do polietileno graftizado com anidrido maléico (PE-g-MA como agente compatibilizante foi avaliada. Os sistemas obtidos foram caracterizados por inflamabilidade, propriedades mecânicas e reológicas, difração de raios X e microscopia eletrônica de transmissão. Os resultados de difração de raios X e microscopia eletrônica de transmissão indicaram a obtenção de nanocompósitos com estruturas parcialmente esfoliadas e/ou intercaladas que conduziram ao aumento do módulo de elasticidade e do valor do torque. O teste de inflamabilidade mostrou que a adição da argila na matriz polimérica e a presença do PE-g-MA retardaram a velocidade de queima do sistema, ou seja, diminuíram a inflamabilidade do PE puro. Em geral, o sistema contendo o agente compatibilizante (PE-g-MA exibiu melhorias na estabilidade térmica e nanocompósitos parcialmente esfoliados foram formados, quando comparados à matriz de polietileno de alta densidade. O polietileno graftizado com anidrido maléico não apenas promoveu a esfoliação da argila, mas também facilitou a adesão carga-matriz, obtendo-se com isso melhorias nos resultados mecânicos do sistema.High density polyethylene/national bentonite clay nanocomposites were prepared with the melt intercalation technique. The effect of the clay without treatment and clay treated with quaternary ammonium salt Cetremide with polyethylene-graft-maleic anhydride as coupling agent was evaluated. The systems were characterized by flammability, mechanical and rheological properties, X ray diffraction and transmission electron microscopy. In general, the results of X ray diffraction and transmission electron microscopy showed partially exfoliated and/or intercalated structures with

  8. ISOTERMAS DE ADSORÇÃO DE COBRE POR BENTONITA

    Directory of Open Access Journals (Sweden)

    Gilvanise Alves Tito

    2008-01-01

    Full Text Available In environmental studies is important to know the adsorption process of heavy metals in clay minerals, since they are able to immobilize these metals. Knowing the cations adsorption is influenced for several factors, the objective of this research was to study the copper adsorption process by bentonite clay and to evaluate the electrolyte type and pH influence on this process. In order to quantify the adsorbed copper, 2 g of bentonite clay were equilibrated for 24 hours with 20 mL of a NaNO3 (0,01 mol L-1 solution and with 20 mL of water containing different quantities of copper (5, 10, 20, 40, 60, 80, 100,120 mg L-1 as background solutions of pH values 4 and 6. Langmuir's adsorption equation in its linearized form was applied and the values of the maximum capacity and those of the constant related to the bonding energy were obtained. Langmuir isotherms presented two distinct adsorption regions at both pH 4 and pH 6, showing that the adsorptive phenomenon occurs in two distinct stages. The adsorption of copper depends on pH and ionic strength and it increased with an increase in pH and decreased slightly with an increase in ionic strength. The maximum capacity of adsorption and the bonding energy varied with the pH, with electrolyte used and with the adsorption regions.

  9. Spanish solid wastes legislation; Legislacion espanola de Residuos Solidos

    Energy Technology Data Exchange (ETDEWEB)

    Castrillon Pelaez, L.; Maranon Maison, E.; Rodriguez Iglesias

    2001-07-01

    A review is made of the regulations in the field of solid wastes with the aim of providing a useful working tool for those entities that generate or manage some type of waste. The coming into force of the current Spanish Wastes Law establishes common regulations for all wastes, substituting all previous Municipal Waste and Toxic and Dangerous Waste Laws. For reasons of greater practical applicability, we have preferred in this paper to classify wastes on the basis of their characteristics. The regulations are thus presented in a series of sections: municipal waste, dangerous wastes, sewage plant sludge, cattle waste and specific risk materials, highlighting in each case those areas of the regulations that are of greater interest for the producers and managers of solid wastes. (Author)

  10. Chitosan/bentonite bionanocomposites: morphology and mechanical behavior; Bionanocompositos quitosana/bentonita: morfologia e comportamento mecanico

    Energy Technology Data Exchange (ETDEWEB)

    Braga, C.R.C.; Melo, F.M.A. de [Universidade Federal de Campina Grande (UFCG), PB (Brazil). Programa de Pos-graduacao em Ciencia e Engenharia de Materiais; Vitorino, I.F. [Universidade Federal de Campina Grande (UFCG), PB (Brazil). Dept. de Ciencia e Engenharia de Materiais; Fook, M.V.L.; Silva, S.M.L., E-mail: suedina@dema.ufcg.edu.b [Universidade Federal de Campina Grande (UFCG), PB (Brazil). Unidade Academica de Engenharia de Materiais

    2010-07-01

    This study chitosan/bentonite bionanocomposite films were prepared by solution intercalation process, seeking to investigate the effect of the chitosan/bentonite ratio (5/1 e 10/1) on the morphology and mechanical behavior of the bionanocomposites. It was used as nanophase, Argel sodium bentonite (AN), was provided by Bentonit Uniao Nordeste-BUN (Campina Grande, Brazil) and as biopolymer matrix the chitosan of low molecular weight and degree of deacetylation of 86,7% was supplied by Polymar (Fortaleza, Brazil). The bionanocomposites was investigated by X-ray diffraction and tensile properties. According to the results, the morphology and the mechanical behavior of the bionanocomposite was affected by the ratio of chitosan/bentonite. The chitosan/bentonite ratio (5/1 and 10/1) indicated the formation of an intercalated nanostructure and of the predominantly exfoliated nanostructure, respectively. And the considerable increases in the resistance to the traction were observed mainly for the bionanocomposite with predominantly exfoliated morphology. (author)

  11. Hydrothermal alterations of Bentonites in Almeria (Spain); Alteracion hidrotermal de las bentonitas de Almeria

    Energy Technology Data Exchange (ETDEWEB)

    Linares Gonzalez, J.; Barahona Fernandez, E.; Huertas Garcia, F.; Caballero Mesa, E.; Cuadros Ojeda, J.

    1996-12-01

    The use of bentonite as backfilling and sealing material in the high level radioactive waste disposals has been treated in previous studies accomplished by different authors. However, the use of this clayey barrier needs the resolution of different problems so that its efficiency will be enhanced. between those could be cited the study of the actual capacity of sealing the space around the canister and the accommodation to the pressure of the rocky environment; the possible variations in plasticity; the diffusion and reaction processes that can be produced through the barrier by groundwater, the capacity of radionuclides adsorption, etc. These studies, show that the bentonites with high content in smectite fulfill satisfactorily with the physical and chemical conditions to be used as sealing material, but it is known that the smectite can be unstable in diagenetic conditions similar to those are given in a deep repository of radioactive wastes, being transformed into illite. A conclusion of immediate interest is deduced from this last study. The bentonites used as sealing material in radioactive waste repositories must no contain Na as interlayer cation since it is very easily exchangeable by K. It is better to select those smectites with Ca and Mg that detain the entry of K in the interlayer and as a consequence the transformation process of smectite into illite is made more difficult. (Author)

  12. Filtración estabilizante en vinos blancos: una alternativa a la bentonita

    OpenAIRE

    López Bonillo, Francisco; Achaerandio Puente, María Isabel; Ferrando, Montserrat; Güell, Carme; Labbé, Mariela; E. Lira; Pandolfi, E.; Pashova, V.; Salazar González, Fernando Noé

    2013-01-01

    La obra recoge los trabajos cientificos presentados a la 27ª reunión anual del grupo de trabajo de experimentación en viticultura y enología, que con el apoyo del Ministerio de Agricultura, Alimentación y Medio Ambiente, se reunió durante los días 8,9 y 10 de mayo de 2012, en el Segurde-Boqueixon (A Coruña). A la reunión asistieron 32 técnicos e investigadores de 14 centros e institutos. Se presentaron un total de 19 comunicaciones, 13 de viticultura, 6 de enología y una sobre la viticultura ...

  13. Preparation and characterization of bentonite organo clay; Preparacao de caracterizacao de argilas bentonitas organofilicas

    Energy Technology Data Exchange (ETDEWEB)

    Bertagnolli, C.; Almeida Neto, A.F. [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Fac. de Engenharia Quimica. Lab. de Engenharia Ambiental; Silva, M.G.C., E-mail: meuris@feq.unicamp.b [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Fac. de Engenharia Quimica

    2009-07-01

    Bentonite clays organically modified have great potential use for environmental remediation, especially in the separation of organic compounds from the water. The aim of this work was the preparation of organophilic clays from 'Verde-Lodo' bentonite clay with the quaternary ammonium salts cetyl-pyridinium chloride and benzalkonium chloride. The materials obtained were characterized by XRD, thermogravimetric analyses, Helium picnometry, SEM and energy dispersive X-ray techniques. The results show consistently successful synthesis of the organoclay through the increase in the basal spacing, as well as salt elimination picks and presence of carbon and chlorine in the modified clays; they are inexistent elements in the natural clay. (author)

  14. Demographic outcomes and ecosystem implications of giant tortoise reintroduction to Espanola Island, Galapagos.

    Directory of Open Access Journals (Sweden)

    James P Gibbs

    Full Text Available Restoration of extirpated species via captive breeding has typically relied on population viability as the primary criterion for evaluating success. This criterion is inadequate when species reintroduction is undertaken to restore ecological functions and interactions. Herein we report on the demographic and ecological outcomes of a five-decade-long population restoration program for a critically endangered species of "ecosystem engineer": the endemic Española giant Galapagos tortoise (Chelonoidis hoodensis. Our analysis of complementary datasets on tortoise demography and movement, tortoise-plant interactions and Española Island's vegetation history indicated that the repatriated tortoise population is secure from a strictly demographic perspective: about half of tortoises released on the island since 1975 were still alive in 2007, in situ reproduction is now significant, and future extinction risk is low with or without continued repatriation. Declining survival rates, somatic growth rates, and body condition of repatriates suggests, however, that resources for continued population growth are increasingly limited. Soil stable carbon isotope analyses indicated a pronounced shift toward woody plants in the recent history of the island's plant community, likely a legacy of changes in competitive relations between woody and herbaceous plants induced by now-eradicated feral goats and prolonged absence of tortoises. Woody plants are of concern because they block tortoise movement and hinder recruitment of cactus--a critical resource for tortoises. Tortoises restrict themselves to remnant cactus patches and areas of low woody plant density in the center of the island despite an apparent capacity to colonize a far greater range, likely because of a lack of cactus elsewhere on the island. We conclude that ecosystem-level criteria for success of species reintroduction efforts take much longer to achieve than population-level criteria; moreover, reinstatement of endangered species as fully functioning ecosystem engineers may often require large-scale habitat restoration efforts in concert with population restoration.

  15. The Dawns of the Spanish Geo technic; Los albores de la Geotecnia espanola

    Energy Technology Data Exchange (ETDEWEB)

    Serrano Gonzalez, A.

    2013-06-01

    From a personal perspective, there are analyzed the first steps of the spanish Geotechnical Engineering history understood as an academic discipline but also linked in a very directly way the profession. This evolution is not foreign to the own history of the Geneticist in other countries of our cultural or geographical environment. The contributions discover that our predecessors transmitted important achievements to the international community. The direct presence in the international congresses of that time of the spanish geo technicians is analysed. Three consecutive stages are distinguished, personalizing in each of them the participation of celebrated spanish Civil Engineers. (Author)

  16. Environmental aspects of the Spanish energy policy. Implicaciones ambientales de la politica energetic espanola

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez Beltran, D. (Ministry of Public Works and Transport, Madrid (Spain))

    1992-01-01

    The environmental aspects of Spanish energy policy are discussed in headings entitled: energy saving as an important environmental requirement, international and community pressures, possible use of economic and fiscal instruments (taxes or incentives) - results of some community analysis, energy efficiency index evolution, need of changes in production systems and consumption models - energy saving plan, and the 'resources user pays principle' towards a sustainable development. 1 fig., 2 tabs.

  17. Productividad Global en la Mineria Espanola: Una Panoramica y Modelos Econometricos.

    OpenAIRE

    Rodriguez, X.A.

    2002-01-01

    En este trabajo estimamos la evolucion de la productividad total en la mineria española durante el periodo 1974-1991. Para ello proponemos la utilizacion de una metodologia de medida generica y flexible, que nos indica la trayectoria de la productividad a partir de los factores o fuentes mas importantes que la determinan. Estos resultados nos permiten deducir las caracteristicas productivas mas relevantes en la mineria española durante el periodo considerado y opinar sobre las perspectivas de...

  18. Analysis of the situation of Spanish metal mining; Analisis de situacion de la mineria metalica espanola

    Energy Technology Data Exchange (ETDEWEB)

    Espi Rodriguez, J. A.; Vazquez Guzman, F.; Leon Altamirano, C.; Perez Macias, D.

    2015-07-01

    This article is a summary of the original document drawn up by the Task Force on Mineral Resources and Reserves of the National Association of Mining Engineers, available in free digital format through the Link. (Author)

  19. Programa de lengua espanola: Guia para el profesor, 2 (Spanish Language Program: Teacher's Guide 2).

    Science.gov (United States)

    Martinez, Emiliano; And Others

    This teacher's guide is designed for use with "La Ciudad" and "Otros Amigos, Otras Culturas," two textbooks in the second part of the Spanish language series of readers. It contains lesson plans to enable the teacher to make better use of the texts and includes illustrations taken from each of the books themselves. (SK)

  20. Realities and paradoxes of the Spanish industry; Realidades y paradojas de la industria espanola

    Energy Technology Data Exchange (ETDEWEB)

    Torrens, L.

    2013-06-01

    Spanish industry has destroyed more than 900,000 jobs since the crisis. However, it has maintained and even increased their production and exports share in the whole European Union. Some indicators show competitive behavior of Spanish industry was correct in front of the rest of its European partners during the real estate bubble. The challenges facing the Spanish industry go through replacing the disappearance of the construction sector by to new emerging and more internationalized sectors. The article introduces the different items on the journal and makes several recommendations based on the results obtained. (Author)

  1. The Sociedad Espanola de Ceramica y Vidrio over half a century

    International Nuclear Information System (INIS)

    The double objective of this lecture is to commemorate, on the occasion of its golden jubilee, the work performed by the Spanish Society of Ceramics and Glass and to pay a special homage to the memory of its main promoter and supporter, Professor Antonio Garcia Verduch. Since its foundation in 1960 the Society has contributed to join all the experts in ceramics and glass, as well as to promote and spread among them scientific and technical knowledge related to both areas, while adapting itself to the investigation trends of each moment in time and to the interests of the different industrial sectors. Along its half century of history it has organized some hundred and twenty-five national congresses and specialized technical meetings and nine national congresses. It represents Spain in five international associations. The Society's main contribution, together with its international activities, has been the uninterrupted publication of its bimonthly magazine, the Society's Bulletin, which since 1999 is included in the database of the Science Citation Index. Furthermore, the Society keeps a permanent relationship with investigation centres, universities, museums, technicians and manufacturers associations and fairground institutions. As a sign of its promotion of technical development, the Society grants every year since 1977 its Alfa de Oro Awards to the most outstanding industrial products shown in the Valencia Fair, in order to highlight quality, technological innovation and design. In 1999 the Society's Electroceramics group created the Epsilon de Oro Awards which are granted every two years to the people or institutions that have produced the main scientific contribution in a given field. (Author).

  2. Decantation time of evaluation on bentonite clays fractionation; Avaliacao do tempo de decantacao no fracionamento de argilas bentonitas

    Energy Technology Data Exchange (ETDEWEB)

    Gomes, J.; Menezes, R.R.; Neves, G.A.; Lira, H.L; Santana, L.N.L., E-mail: lisiane@dema.ufcg.edu.b [Universidade Federal de Campina Grande (UFCG), PB (Brazil). Dept. de Engenharia de Materiais

    2009-07-01

    Bentonite clays present a great number of industrial uses, from petroleum to pharmaceutics and cosmetic industry. The bentonite clay present particles with very fine particles that is responsible by the vast application of these materials. However, commercial clays present wide particle size distribution and a significant content of impurities, particularly quartz, in the form of silt and fine silt. So, the aim of this work is to analyze the effect of the stirring and decantation time in the deagglomeration, purification and size separation of the bentonite clay particles from Paraiba. The clays were characterized by X-ray diffraction and particle size distribution. Based on the results it was observed the decantation time give the elimination of the agglomerates formed by submicrometric particles. The uses of decantation column give separation of the fraction below 200nm. (author)

  3. Experimental Setup to Characterize Bentonite Hydration Processes; Diseno experimental para la caracterizacion de los procesos de hidratacion de la bentonita

    Energy Technology Data Exchange (ETDEWEB)

    Bru, A.; Casero, D.; Pastor, J.M.

    2001-07-01

    We present an experimental setup to follow-up the hydration process of a bentonite. Clay samples, of 2 cm x 12 cm x 12 cm, were made and introduced in a Hele-Shaw cell with two PMM windows and two steel frames. In hydration experiments, a fluid enters by an orifice in the frame, located both at the top and the bottom of the cell, to perform hydration in both senses. To get a uniform hydration we place a diffuser near the orifice. Volume influxes in hydration cells are registered in time. The evolution of the developed interface was recorded on a videotape. The video cameras was fixed to a holder so that the vertical direction in the monitor was the same as the direction of the larger extension of the cell. (Author) 6 refs.

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

    OpenAIRE

    C. Volzone; L.B. Garrido

    2002-01-01

    Retention of chromium (III) from a tanning wastewater by modified Al-bentonites was studied. One bentonite from San Juan province, Argentina, was used. Al-bentonite was prepared by contact of bentonite with hydrolyzed OH-Al solutions (0.10 M in Al) for 24 hours. The modified Al-bentonites were obtained by: a) treatment with 0.5 M sodium chloride; b) with 0.5 M sodium chloride adjusted at pH 8; and c) treatment with an hexametaphosphate solution after sodium addition. Then, the samples were dr...

  5. Lifetime of Bentonites study: hydrothermal stability of saponites; Estudio de longevidad en bentonitas: estabilidad hidrotermal de saponitas

    Energy Technology Data Exchange (ETDEWEB)

    Leguey, S.; Cuevas, J.; Garralon, A. [Universidad Autonoma de Madrid, Facultad de Ciencias, Departamento de Quimica Agricola, Geologia y Geoquimica, Madrid (Spain)

    1996-10-01

    The report studies the lifetime of bentonite and the hydrothermal stability of saponites. The testing comprised determination of physical and chemical properties of clays, the stability of the mineral porosity, lifetime and the wall of clay.

  6. Asociacion Espanola de la Industria Electrica (UNESA) annual report 2006. Information about electricity activities; Asociacion Espanola de la Industria Electrica UNESA 2006 memoria estadistica. Informe sobre las actividades electricas

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-07-01

    The annual report of UNESA, the industrial grouping of major power companies in Spain, gives statistical data relating to power generation, transmission and distribution and a summary of achievements during 2006. Power is generated from fossil fuel, nuclear, and hydro power. Cooperation of UNESA with international organizations is reported. Detailed figures are given for electricity production during the year. A summary of the report is available in English and Spanish on the website www.unesa.es.

  7. The stress tests performed by the Spanish nuclear power plants.; Las pruebas de resistencia realizadas a las centrales nucleares espanolas

    Energy Technology Data Exchange (ETDEWEB)

    Alonso, J. R.

    2011-07-01

    In the wake of the accident that occurred at Fukushima nuclear power plant in Japan, the European Union decided to subject the European plants to a reassessment of their safety margins, in accordance with the lessons learned from that accident. On December 31st last, following a process of exhaustive analysis, the Nuclear Safety Council submitted the final reports corresponding to the evaluations performed by the Spanish nuclear power plants, with the results obtained and conclusions drawn. Also detailed are the actions proposed to improve the nuclear safety of these facilities in response to extreme situations. (Author)

  8. Conservation promotion policy of the Spanish energy industry; Politica de promocion de conservacion de la energia en la industria espanola

    Energy Technology Data Exchange (ETDEWEB)

    Alonso, Juan Antonio

    1992-03-01

    This paper focalizes the energy general policy of Spain from the National Energy Plan (1991-2000), presenting the strategic lines and testing the main decisions to be adopted in this present decade 5 tabs.

  9. 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.

  10. The service lifetime of Spain's nuclear plants; La vida util de las centrales nucleares espanolas

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez-Bolanos, M.

    2008-07-01

    In recent years consideration has been given to the long-term operation of nuclear reactors, beyond their originally foreseen design lifetime. This article analyses the legal and safety requirements that this implies, in the wake of the document dealing with this issue that was approved by the Plenary of the CSN in April 2005. The article is completed with an interview with Dale Klein, president of the United States regulatory body, in which he describes the experience accumulated in his country, where lifetime extensions have already been approved for 50 plants. (Author)

  11. {sup 14}C in human diet in three Spanish locations; {sup 14}C en dieta humana en tres localizaciones espanolas

    Energy Technology Data Exchange (ETDEWEB)

    Gomez Martinez, I.; Santos Arevalo, F. J.; Manjon, G.; Garcia-Tenorio, R.

    2011-07-01

    {sup 14}C reach humans via the diet. In this study we present the results of diet samples from three locations type Spanish, Seville, Caceres and Tenerife. These diets are collected quarterly and historical dates back to early 2008.

  12. The future of the coal on the energetic Spanish policy; El futuro del carbon en la politica energetica espanola

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2008-07-01

    This work was born as a result of the decision of the Foundation for Studies on energy, to undertake and analysis on the role of coal in the X XI century, because although coal appears as the fuel to be most affected by the provisions of the fight against global warming, it must be recognized its essential contribution in ensuring the power supply and to contain the cost of the kWh. The study was prepared by a group of professionals of the energy sector, without direct commercial links with the subject discussed, but with acknowledges expertise technique. It is pertinent to stress that the purpose of this study is to provide data and analyze rigorously technical options with a view to be able to use the coal energy, minimizing and, theoretically, eliminating the CO{sub 2} emissions. It is therefore not a document produced from predetermined positions, but it is deducted from the characteristics of the nature and mechanisms and other processes involved in generating electricity from coal, and in the treatment of generated CO{sub 2} for it not to reach the atmosphere. We intend to contribute to the better understanding by our society, a major problem for our economy and out welfare. (Author)

  13. The role of the consulting engineering and Spanish; el papel de la Ingenieria y la Consultoria Espanolas

    Energy Technology Data Exchange (ETDEWEB)

    Manzanedo del Rivero, I.; Casanova Valcazar, M.

    2011-07-01

    Within the Spanish energy model, the role assigned to the engineering and consulting is extensive, you must define an energetic mix. Aside for studies and projects are the product of everyday classic engineering companies, on the other, energy audits are a tool of the first order to know the current situation regarding energy consumption and to propose actions and measures that seek better use of energy and convergence with the model defined. (Author)

  14. Sources for researching the business history of Spanish mining; Fuentes para la historia empresarial de la mineria espanola

    Energy Technology Data Exchange (ETDEWEB)

    Perez de Perceval Verde, M. A.; Lopez-Morell, M. A.

    2013-09-01

    This article analyzes the sources available when studying the firms that have exploited underground resources in Spain in contemporary times. The materials we have are diverse, given the variety of mining areas, minerals, types of firms, nationalities involved, etc. Large businesses are covered, in the main, by business archives, which have evolved in different ways, whilst for smaller concerns and when reconstructing an overall business and production map the researcher is better served by tax registers, in particular those on the gross production tax. A wide set of sources with details of where to find them, what they offer, the obstacles they can produce and how best to use them to study the mining business fabric is also included. (Author)

  15. Reference dose levels in dental radiology Spanish; Niveles de dosis de referencia en la radiologia dental espanola

    Energy Technology Data Exchange (ETDEWEB)

    Velasco Hidalgo, F.; Velasco Hidalgo, E.; Alcaraz-Saura, M.; Martinez Garcia-Cervantes, A.; Andreu-Galvez, M.; Martinez-Beneyto, Y.; Alcaraz Banos, M.

    2011-07-01

    Our goal is to evaluate the DRLs to obtain a diagnostic image of a second upper molar in the usual conditions of clinical practice in recent years to assess the evolution of the doses administered to the patient during the last 8 years.

  16. Environmental management systems implemented in the Spanish nuclear power plants; Sistemas de gestion ambiental implantados en las centrales nucleares espanolas

    Energy Technology Data Exchange (ETDEWEB)

    Redondo, R.; Fernandez Guisado, M. B.; Hortiguela, R.; Bustamante, L. F.; Esparza, J. L.; Villareal, M.; Yague, F.

    2013-09-01

    The companies that own the Spanish Nuclear Power Plants, aware of social concern and in the context of a growing demanding environmental legislation, have a permanent commitment to the electricity production based on the principles of a maximum respect for the environment, safety, quality, professionalism and continuous improvement. In order to minimize the environmental impact of their plants they have implemented and Environmental Management System based on the ISO 14001 Standard. They minimize the environmental impact by identifying the significant environmental aspects and defining the corresponding objectives. This article describes the referred environmental management systems and their environmental objectives, as applied and defined by the Spanish Nuclear Power Plants. (Author)

  17. American legislation European and Spanish regulation on hazardous wastes; Apuntes sobre la legislacion americana, comunitaria y espanola sobre residuos peligrosos

    Energy Technology Data Exchange (ETDEWEB)

    Arango Mesa, H. [Universidad del Valle, Cali, Colombia (Colombia); Gomer Gotor, A. [Universidad de las Palmas de Gran Canaria, Canairias (Spain)

    1999-08-01

    This article approaches the Dangerous Residuals from the point of view of the effective legislation in the United States and the European Community, making emphasis in the Spanish Legislation by Considering it an extension of the normative of the European Community. (Author)

  18. The remuneration and performance evaluation of Spanish innovative firms; La retribucion y la evaluacion del desepeno en empresas innovadoras espanolas

    Energy Technology Data Exchange (ETDEWEB)

    Camelo Ordaz, C.; Fernandez Alles, M. L.; Valle Cabrera, R.

    2010-07-01

    This paper reviews the theoretical basis about the agency problem and the governance mechanisms utilised in order to reduce it. After explaining briefly other mechanisms to reduce agency problem, the paper focuses on the role of board of directors, analysing its functions and responsibilities. Finally, we explore the boards of directors of a Spanish sample over the period of 2004 through 2008, showing the fulfilment's degree of Unified Code's recommendations of 2006. (Author) 44 refs.

  19. Radiation hazard surveillance in spanish uranium mines; Control de los peligros de la radiactividad en las minas de uranio espanolas

    Energy Technology Data Exchange (ETDEWEB)

    Iranzo, E.; Liarte, J.

    1963-07-01

    The regulations applied in the uranium mines which belong to the Junta de Energia Nuclear to control the radioactive hazards, and to get the personal protection avoiding overexposures in the external radiation and inhalation of radioactive dust and gases are given. The Radon daughters concentration in the atmosphere of Avery one of the mines and the external radiation exposure and uranium excretion in urine of the miners during 1962 are specified. (Author) 9 refs.

  20. The effectivity of bentonites in cesium retention of cemented waste products; Efetividade das bentonitas na retencao de cesio em produtos de rejeitos cimentados

    Energy Technology Data Exchange (ETDEWEB)

    Tello, Cledola Cassia Oliveira de

    2001-01-15

    The nuclear energy has been used for the human development in different areas, as in the medicine, in the agriculture, in the industry and in the environmental protection, besides the electricity generation. As in other activities, in the use of nuclear energy, residues are also generated. They are considered radioactive wastes when the contaminant content can bring a potential negative impact in the human health and in the environment. In this case they should be properly managed and should not be released without treatment. In general the waste processing consists in a volume reduction followed by solidification and/or conditioning. A number of materials can be considered as immobilisation matrices for the wastes, with the objective of maintain the radioactive material physical and chemically stable. The cement is extensively used because it is easy to obtain, there is large. experience in its use and the processing is done at room temperature. Many materials have been studied to improve the fixation characteristics of the radionuclides in the cemented product. The aim of this study was to search, among Brazilian natural materials, those that could be effective in the contaminant retention without jeopardising the process and other characteristics of the waste product. Four types of bentonite were selected to the process and product evaluation tests. Many mixtures were prepared with simulated waste, cement and bentonite in different proportions. The viscosity, set time, compressive strength and leaching were evaluated. In addition it was verified if the products were monolithic and without free water. Inactive caesium was used as tracer. The leaching resistance is the most important parameter in the product evaluation, because it indicates the retention capacity of the matrix for radionuclides when the product is in contact with the water. In 1985 leaching tests were begun and they have been continued till now and from their results it was proved that the bentonites were efficient in the caesium retention. The leaching data were analysed by a BNL computer program that models four release mechanisms. A good fit was obtained for the partition mechanism. The results obtained in this study can be used in the repository safety assessment. (author)

  1. Study of the Properties of Bentonites for their use in Clay Geo synthetic Barriers; Estudio de la propiedades de las bentonitas para su utilizacion en barreras geosinteticas arcillosas

    Energy Technology Data Exchange (ETDEWEB)

    Leiro Lopez, A.; Mateo Sanz, B.; Garcia Cidoncha, H.; Blanco Fernandez, M.

    2014-02-01

    Bentonites used for the production of clay geo synthetic barriers need to meet some properties so that they can be a waterproofing system. among the bentonites used in industry, sodium bentonite has the lowest permeability due to its high water absorption capacity in the inter-laminar space, causing it to swell and form a barrier to water flow. this paper provides the study of the properties of four bentonite to evaluate their quality the study of the properties of four bentonite to evaluate their quality. For this study, the main properties have been tested: water absorption, swelling index, fluid loss, cation exchange capacity and montmorillonite content. In order to optimize the procedure for the characterization of bentonites, correlations between different tests have been done, to identify the most suitable ones. Finally, a compatibility test has been carried out to study the performance of bentonites in water containing a high amount of sales, because in this case, an ion exchange between the interlayer sodium ions of bentonite and cations dissolved in the water can take, resulting in a decrease swell of the bentonite. (Author)

  2. Geochemical Processes and compacted bentonite FEBEX with a thermohydraulic gradient with a thermohydraulic gradient; Procesos geoquimicos y modificaciones texturales en bentonita FEBEX compactada sometida a un gradiente termohidraulico

    Energy Technology Data Exchange (ETDEWEB)

    Leguey Jimenez, S.; Cuevas Rodriguez, J.; Martin Barca, M.; Vigil de la Villa Mencia, R.; Ramirez Martin, S.; Garcia Gimenez, R. [Universidad Autonoma de Madrid (Spain)

    2002-07-01

    At present, the main source of High Level radioactive Waste (HLW) is the electrical energy production during all sep of developing. In almost all the countries with nuclear programs, the option for the final management of HLW is the Deep Geological Repository (DGR), based on the concept of multi barrier. According to this concept, the wastes is isolated from biosphere by the interposition of confinement barrier. In the context of an investigation of the near field for a repository of HLW, the FEBEX Project, a set of laboratory test has been designed to give a better understanding of the thermo-hydro-mechanical and geochemical behaviour of the compacted bentonite as a confinement barrier. The object of these work is to analyse the properties of the bentonite and its behaviour under conditions that will be found in a repository. The precipitation of mineral phases, due to local changes in the chemical equilibrium and the hydration itself, can produce changes in the salinity of the interstitial water and in the microstructural organisation of the clay particles. the hydraulic and mechanical properties of the bentonite can be modified by the special conditions of the barrier. (Author)

  3. Bentonite clay purification for development of polymeric nan composites using a single screw extruder; Purificacao de argila bentonita para desenvolvimento de nanocomposito polimerico utilizando uma extrusora rosca simples

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-07-01

    In this work, a bentonite clay rich in montmorillonite was purified and chemical treat to be used in the development of poly (methyl methacrylate) /clay nanocomposites via melting processes. After the clay treatment and purification, a masterbatch with 25% clay and 75% PMMA was produced by solution technique, using acetone as solvent. For produce samples with 2.5% clay, the masterbatch along with pure polymer were added and mixed in single screw extruder with a diameter of 16 mm and W/D 26. X-rays diffractometry (XRD) and X-rays fluorescence (XRF). Tests were performed to evaluate and characterizing the bentonite clay used in the development of this work and differential scanning calorimetry (DSC) tests were performed to evaluate changes in the thermal properties of the nanocomposites produced. (author)

  4. Modifications in Compacted MX-80 Bentonite Due to Thermo-Hydraulic Treatment; Modificaciones en la Bentonita MX-80 Compactada Sometida a Tratamiento Termo-Hidraulico

    Energy Technology Data Exchange (ETDEWEB)

    Gomez-Espina, R.; Villar, M. V.

    2013-09-01

    The thermo-hydraulic tests reproduce the thermal and hydraulic conditions to which bentonite is subjected in the engineered barrier of a deep geological repository of radioactive waste. The results of thermo-hydraulic test TBT1500, which was running for approximately 1500 days, are presented. This is a continuation to the Technical Report Ciemat 1199, which presented results of test TBT500, performed under similar conditions but with duration of 500 days. In both tests the MX-80 bentonite was used with initial density and water content similar to those of the large-scale test TBT. The bentonite column was heated at the bottom at 140 degree centigrade and hydrated on top with deionized water. At the end of the test a sharp water content gradient was observed along the column, as well as an inverse dry density gradient. Hydration modified also the bentonite microstructure. Besides, an overall decrease of the smectite content with respect to the initial value took place, especially in the most hydrated areas where the percentage of interest ratified illite increased and in the longer test. On the other hand, the content of cristobalite, feldspars and calcite increased. Smectite dissolution processes (probably colloidal) occurred, particularly in the more hydrated areas and in the longer test. Due to the dissolution of low-solubility species and to the loss of exchangeable positions in the smectite, the content of soluble salts in the pore water increased with respect to the original one, especially in the longer test. The solubilized ions were transported; sodium, calcium, magnesium and sulphate having a similar mobility, which was in turn lower than that of potassium and chloride. The cationic exchange complex was also modified. (Author)

  5. Gas transport in the bentonite barrier of AGP and their interfaces; Transporte de gas en la barrera de bentonita de un AGP y sus interfases

    Energy Technology Data Exchange (ETDEWEB)

    Gutierrez Rodrigo, V.; Villar Gelicia, M. V.; Martin Martin, P. L.; Romero Alvarez, F. J.

    2014-07-01

    The research of gas transport processes through the barriers is of great relevance in the assessment of the behaviour of the repository. The main objective of this study is to determine the properties of gas transport in saturated bentonite samples and the interfaces between them. (Author)

  6. Caracterização e propriedades do material coloidal nanoestruturado β-FeOOH/bentonita Characterization and properties of colloidal β-FeOOH/bentonite nanostructured material

    Directory of Open Access Journals (Sweden)

    Fauze Jacó Anaissi

    2009-01-01

    Full Text Available A new mixed material was obtained through the combination of the suspensions of iron oxy-hydroxide and bentonite clay, denoted BFe. Analysis of its structure (XRD, Mossbauer and TGA and composition (AAS suggests the maintenance of the layer structure of the clay and an increase in the thermal stability of the BFe. Electrochemical studies performed in different electrolytes show that only in an alkaline medium it is possible to observe the redox peaks relative to the processes involving Fe+2/Fe+3 pair. Tests that evaluated the potential use of the photo-Fenton process showed an efficient degradation process of the dyes in significantly reduced reaction times.

  7. Study of mechanical properties of films of nanocomposites LLDPE/bentonite; Estudo das propriedades mecanicas de filmes de nanocompositos PEBDL/bentonita

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Eduardo M.; Carvalho, Laura H.; Canedo, Eduardo L.; Coutinho, Maria G.F.; Costa, Raquel B., E-mail: laura@dema.ufcg.edu.br [Unidade Academica de Engenharia de Materias, Universidade Federal de Campina Grande (UAEMa/UFCG) Campina Grande, PB (Brazil); Araujo, Arthur R.A. [Felinto Industria e Comercio Ltda., Campina Grande, PB (Brazil)

    2011-07-01

    Mechanical properties of LLDPE/bentonite clay were determined as a function of clay content (1 and 2% w/w), purification and organophilization. Raw materials were characterized by FTIR and XRD. Nanocomposites were obtained as flat films and characterized by XRD and mechanical properties. Results indicate that best overall mechanical properties were displayed by systems containing purified clay and that they tended to decrease with increasing clay content. Organofilization was effective and only intercalated nanocomposites were obtained. (author)

  8. Preparation and performance of Ecobras/bentonite biodegrading films; Preparacao e desempenho de filmes polimericos biodegradaveis a base de Ecobras e bentonita

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Ana Nery M.; Melo, Nadja M.C.; Canedo, Eduardo L.; Carvalho, Laura H., E-mail: laura@dema.ufcg.edu.br [Unidade Academica de Engenharia de Materiais, Universidade Federal de Campina Grande (UAEMa/UFCG) Campina Grande, PB (Brazil); Araujo, Arthur R.A. [Felinto Industria e Comercio Ltda., Campina Grande, PB (Brazil)

    2011-07-01

    Compounds based on the biodegradable polymer Ecobras and bentonite clay in its pristine, sonicated, and organically modified with a quaternary ammonium salt forms were prepared as flat films. Clays and compounds were characterized by x-ray diffraction and scanning electron microscopy. Mechanical properties of the films were determined according to pertinent ASTM standards. Reasonable properties, higher than those of the matrix, were obtained with compounds prepared with purified clays and organoclays, particularly for low clay loading. (author)

  9. Hydrothermal alkaline stability of bentonite barrier by concrete interstitial wastes; Alteracion alcalina hidrotermal de la barrera de bentonita por aguas intersticiales de cementos

    Energy Technology Data Exchange (ETDEWEB)

    Leguey Jimenez, S.; Cuevas Rodriguez, J.; Ramirez Martin, S.; Vigil de la villa Mencia, R.; Martin Barca, M. [Universidad Autonoma de Madrid, Madrid (Spain)

    2002-07-01

    At present, the main source of High Level radioactive Waste (HLW) is the electrical energy production during all the steps of developing. In almost all the countries with nuclear programs, the option for the final management of HLW is the Deep Geological Repository (DGR) based on the concept of multi barrier. According to this concept, the waste is isolated from biosphere by the interposition of confinement barriers. Two of the engineering barriers in the Spanish design of DGR in granitic rock are compacted bentonite and concrete. The bentonite barrier is the backfilling and sealing material for the repository gallery, because of its mechanical and physico-chemical properties. The main qualities of concrete as a component of a multi barrier system are its low permeability, mechanical resistance and chemical properties. With regard to chemical composition of concrete, the alkaline nature of cement pore water lowers the solubility of many radioactive elements. However, structural transformation in smectite, dissolution or precipitation of minerals and, consequently, changes in the bentonite properties could occurs in the alkaline conditions generated by the cement degradation. The main objective of the present work is to evaluate the effect of concrete in the stability of Spanish reference bentonite (La Serrata of Nijar, Almeria, Spain) in conditions similar to those estimated in a DGR in granitic rock. Because of the main role of bentonite barrier in the global performance of the repository, the present study is essential to guarantee its security. (Author)

  10. Membrane Bioreactors design and operation improvements: The Spanish Experience; Avances en el diseno y la operacion de los biorreactores de membrana: La experiencia espanola

    Energy Technology Data Exchange (ETDEWEB)

    Iglesias Esteban, R.; Ortega de Miguel, E.; Martinez Tarifa, M. A.; Simon Andreu, P.; Moragas Bouyart, L.; Garcia Fernandez, E.; Robuste Cartro, J.; Rodriguez-Roda layret, I.

    2012-07-01

    A Membrane Bioreactor (MBR) is a modification of a conventional activated sludge (CAS) plant where the secondary settling ins replaced by a low pressure ultrafiltration (UF) or micro filtration (MF) membranes separation process in order to obtain an effluent almost free of suspended solids and microorganisms. since the first MBR installation in 2002, the number and capacity of these systems have exponentially increased in spain, driven by the high quality of the effluent which allows direct reuse and discharge into environmentally sensitive areas, the compactness and automation of these plants and the possibility of upgrading existing wastewater treatment plants (WWTP) which no longer reach the required effluent quality levels. There were 45 operating MBR systems in 2011 and the total municipal wastewater treatment capacity by this type of plants will be about 90 hm{sup 3} in 204 when the current projects have been implemented. Today, Spain public and private wastewater management agencies consider MBR plants as an alternative of treatment but first they had to face a complex learning period to operate and design this kind of system. A significant progress has been made over the last years, but especially energy efficiency responds to the challenge of continuous improvement. Membrane fouling control consumes most of the energy involved in the process therefore, anti fouling materials and better membrane air-scour systems that allow the frequency and intensity of air flow to be controlled in realtime, are being investigated. This brings MBR closer to the CAS process in terms of energy efficiency. Breakthroughs in the design and operation of MBR plants are being collected in a guide for the implementation of MBR led by CEDEX, in which the main managers and operators are involved. This paper presents some of these improvements. (Author) 9 refs.

  11. Genetic-Structural relations in some types of spanish uranium deposits; Relaciones genetico-estructurales de algunos tipos de mienralizaciones uraniferas espanolas

    Energy Technology Data Exchange (ETDEWEB)

    Alia Medina, M.

    1962-07-01

    On the spanish hercynian areas there are different types of uraniferous deposits, which may be classified in the following groups: Group I, high temperature magmatic deposits, Group II, low temperature veins and Group III supergenic deposits, generated by weathering of the former ones or by lixiviation of the intra granitic uranium. The deposits belonging to Group I are founding the hercynian ge anticlinal; those of Groups II and III, chiefly in the eugeosyncline. The explanation suggested for these genetic-structural relationships assumes that, in the ge anticlinal, uranium would migrate from the dioritic magmas to form and high temperature deposits. In the eugeosyncline, a large fraction of the uranium would migrate towards more differentiated granites, in which it might partially remain or from which it might have been finally concentrated in the epithermal veins or by later tectonic actions. The Group III deposits ar more frequent in the eugeosyncline, due to the greater abundance of more differentiated intrusive rocks. (Author) 16 refs.

  12. Spanish firms patenting in the European office. characteristics compared with non-applicant; Las empresas espanolas que patentan en la oficina Europea. Caracteristicas comparadas con las no solicitantes

    Energy Technology Data Exchange (ETDEWEB)

    Barajas, A.; Huergo, E.; Moreno, L.

    2012-07-01

    The objective of this paper is to provide evidence about the features of Spanish firms applying for patents to the European Patent Office between 1998 and 2008. We compare these firms with a control sample of non-applicants during the same period and focus especially on firms that have been awarded public aid for R and D projects by the Centre for the Development of Industrial Technology. (Author) 14 refs.

  13. Spanish experience in the use of synthetic geo membranes for hydraulic works; Experiencia espanola en el uso de geomembranas sinteticas en obras hidraulicas

    Energy Technology Data Exchange (ETDEWEB)

    Blanco Fernandez, M.; Leiro Lopez, A.

    2014-02-01

    The Spanish institution Centro de Estudios y Experimentacion de Obras Publicas (CEDEX) has studied for decades the behaviour of geosynthetic products, specially the polymeric geo synthetic barriers used as waterproofing systems of different hydraulic works, mainly in reservoirs. Both in geotextiles or related products and in geomembranes, initial characteristics are determined; besides of that, periodic controls along the service life are performers in geomembranes. The monitoring of more than two hundred hydraulic structure hydraulic structures requires technical inspection, taking samples and replacing them, experimental tests and recommendations, with the purpose of increasing security and durability in hydraulic structures. Because of that, the Spanish experience in this field of technology is presented along this paper. (Author)

  14. Stability analysis criteria in landfill design based on the Spanish code; Criterios de estabilidad en el diseno de un vertedero, basado en la normativa espanola

    Energy Technology Data Exchange (ETDEWEB)

    Estaire Gepp, J.; Pardo de Santayana, F.

    2014-02-01

    The design of a landfill requires performing stability analyses. To perform such analyses it is necessary to define different design situations and their corresponding safety factors. Geo synthetics are normally used to construct the lining system of the landfills, causing critical slip surfaces to pass along one of the different geo synthetic interfaces. Determination of the shear strength of such critical interfaces is, therefore, an extremely important issue. In this paper, these aspects are analysed based on what is set in the Spanish codes and in the technical literature. As a result of the study, some tables are presented which relate the different design situations (normal, accidental or extraordinary) to the shear strength of the lining system to be used (peak or residual) and define the minimum factor of safety to be accomplished. (Author)

  15. Evolution of Spanish industrial companies in the first decade of XXI century; Evolucion de las empresas industriales espanolas en la primera decada del siglo XXI

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez Tirados, R. M.; Medina Rojas, S.

    2011-07-01

    This article discusses the key issues that have influenced the evolution of Spanish industrial companies in the first decade of XXI century. This evolution is clearly influenced by the economic crisis that began in 2007 and has become clear in 2008. As for industrial production, is made a forecast based on an data analysis and the results have achieved if the current economic crisis would not have taken place. Another aspect presented refers to the organization of Spanish companies, the influence of industrial policy and equally, the role of technology parks and synergy's between university-business to these parks. (Author)

  16. Participation of CIEMAT in 27th annual meeting of the Spanish Nuclear Safety; Participacion del CIEMAT en la 27 Reunion Anual de la Sociedad Nuclear Espanola

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-07-01

    The book assembles the paper of researches of CIEMAT during the 27th annual meeting of Spanish Nuclear society. The paper were presented during the following sessions: 1. Maintenance and in-service inspection 2. Radioactive wastes. 3. Environment 4. R and D management 5. Nuclear Safety. 6. Lifetime. (Author)

  17. European Spallation Source ESS. Spanish participation in the ESS Primary system design; Fuente Europea de Spallation ESS. Participacion espanola en el diseno del sistema primario de la ESS

    Energy Technology Data Exchange (ETDEWEB)

    Dominguez, M. T.; Albisu, F.

    2001-07-01

    Neutron scattering provides basic microscopic information on the structure and dynamics of materials which underpins our understanding of condensed matter in fields as diverse as biology, material science chemistry, earth sciences and physics. Europe is preeminent, in this field and the current proposal for a next generation neutron source, the European Spallation source (ESS), will ensure that neutron beams of the highest quality are available early next century to a broad spectrum of users from academia and industry. In the Large Facilities Report to the Commission of the European Community (CEC) in 1990, the Neutron Study Panel underlined the continuing need for neutron scattering and recognised that a major initiative was necessary to secure an effective on-going neutron science programme in Europe for the year 2000 and beyond. (Author)

  18. Participation of CIEMAT in 26th annual meeting of the Spanish Nuclear Safety; Participacion del CIEMAT en la 26 reunion anual de la Sociedad Nuclear Espanola

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    The book assembles the paper of researches of CIEMAT during the 26th annual meeting of Spanish Nuclear society. The paper were presented during the following sessions: 1. Maintenance and in-service inspection 2. Radioactive wastes 3. Environment 4. R and D management 5. Nuclear Safety 6. Lifetime.

  19. Medical Physics in the new undergraduate curriculum of Spanish medical schools; La Fisica Medica en los nuevos planes de estudio de grado de las facultades de medicina espanola

    Energy Technology Data Exchange (ETDEWEB)

    Guibelalde, E.; Calzado, A.; Chevalier, M.

    2011-07-01

    The purpose of this paper is to present a systematic review of the contents of Medical Physics in the curricula of the new curriculum Grade in Spanish medical schools after the entry into force of that legislation.

  20. The logistics, the key for the competitiveness of the Spanish vehicle manufacturing plants; La logistica, clave para la competitividad de las plantas espanolas de fabricacion de vehiculos

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Lopez, A.

    2012-07-01

    This article aims to outline the logistics chain in the automotive sector and analyze the current situation of the different modes of transport for finished vehicles. Nowadays the Spanish production plants depend on the export, wage levels are very close to the European average and transport costs are winning importance. With the integration of new EU countries with cheaper labor costs and more favorable geographical situation, the distribution logistics become a key variable for the competitiveness of Spanish automotive industry. All data used come from official sources and are as updated as possible. (Author)

  1. What they have in common the engineering from the Spanish nuclear power plants?; Que tienen en comun las ingenierias de las centrales nucleares espanolas

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Mendez, M.

    2012-11-01

    In recent years, Spain Nuclear Power Plant Engineering have switched their project/task management method to Critical Chain multi-project management, developed by Dr. Goldratt, achieving outstanding results in improving quality and productivity. Multitasking reduction, task and resource synchronizing without the need of exact schedules, implementing a real-time priority information system, relying on the software Concerto, and daily decision making are the basis for the management change that has generated productivity increases of between 20% to 50%, opening new horizons for improvement in other scenarios such as optimizing refueling shutdowns. (Author)

  2. Fuel cycle management by the electric enterprises and spanish nuclear Power plants; Gestion del ciclo de combustible por las empresas electricas y centrales nucleares espanolas

    Energy Technology Data Exchange (ETDEWEB)

    Celma, E. M.; Gonzalez, C.; Lopez, J. V.; Melara, J.; Lopez, L.; Martinez, J. C.; Culbras, F.; Blanco, J.; Francia, L.

    2015-07-01

    The Nuclear Fuel Group reports to the Technology Committee of the UNESA Nuclear Energy Committee, and is constituted by representatives of both the Spanish Utilities and the Nuclear Power Plants. The Group addresses the nuclear plant common issues in relation to the operation and management of the nuclear fuel in their different stages of the Fuel Cycle. The article reviews the activities developed by the Group in the Front-End, mainly in the monitoring of international programs that define criteria to improve the Fuel Reliability and in the establishment of common bases for the implementation of changes in the regulation applying the nuclear fuel. Concerning the Back-End the Group focuses on those activities of coordination with third parties related to the management of used fuel. (Author)

  3. Evaluating wind power potential in the Spanish Antarctic Base (BAE); Evaluacion del Potencial Eolico en la Base Antartica Espanola Juan Carlos I

    Energy Technology Data Exchange (ETDEWEB)

    Arribas de Paz, L. M.; Garcia Barquero, C.; Navarro Montesinos, J.; Cuerva Tejero, A.; Cruz Cruz, I.; Roque Lopez, V.; Marti Perez, I. [Ciemat. Madrid (Spain)

    2000-07-01

    The objective of the work is to model wind field in the surroundings of the Spanish Antarctic Base (BAE in the following). The need of such a work comes from the necessity of an energy source able to supply the energy demand in the BAE during the Antarctic winter. When the BAE is in operation (in the Antarctic summer) the energy supply comes from a diesel engine. In the Antartic winter the base is closed, but the demand of energy supply is growing up every year because of the increase in the number of technical and scientific machines that remain in the BAE taking different measurements. For this purpose the top of a closed hill called Pico Radio, not perturbed by close obstacles, has been chosen as the better site for the measurements. The measurement station is made up with a sonic an-emometer and a small wind generator to supply the energy needed by the sensors head heating of the anemometer. this way, it will be also used as a proof for the suitability of a wind generator in the new chosen site, under those special climactic conditions. (Author) 3 refs.

  4. Application of Spanish legislation on radiation protection in contaminated soils; Aplicacion de la normativa espanola sobre suelos contaminados en proteccion radiologica

    Energy Technology Data Exchange (ETDEWEB)

    Trueba Alonso, C.; Robles Atienza, B.

    2013-07-01

    As the developments that have led the regulations on contaminated soils conventional pollutants are more advanced than those due to radioactive contaminants, this work is a state of the art of the current situation and is framed within the developments in R and D for radiation protection of the public and the environment. (Author)

  5. Electromagnetic fields and safety : information and risk perception in Spanish population; Campos electromagneticos y salud: informacion y percepcion del riesgo en la poblacion espanola

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, A.; Guillen, V.

    2005-07-01

    There is a lack of knowledge about both the information the general population in Spain has on electromagnetic fields (EMF) and the public risk perception regarding the exposure to non-ionizing EMF emitting sources. The aims of the present preliminary survey were to assess what the Spanish population knew about EMF, to explore their health risk perception associated with the exposure to commonly used sources of non-ionizing radiation; and to know their risk perception regarding cell towers. A total number of 801 adult participants, randomly selected answered a telephone interview based on a 13-item semi-structured questionnaire. Sixty-nine per cent of the interviewees reported having no knowledge about electromagnetic fields. Up to 88.9% mentioned to have a little or no information at all on the health effects of EMF. Comparing risk perception regarding several commonly used devices, mobile telephones and microwave ovens were associated with a higher heath risk than TV and computers. Of those who believed that the devices mentioned were linked with health problems, 40.7% associated them with cancer. Regarding base stations, 52.1% of the sample envisioned such sources as a health risk, and of those who believed so, the majority linked the proximity of base stations with cancer. Gender differences were observed in risk perception. (Author) 16 refs.

  6. Desenvolvimento de fluidos aquosos com bentonita para perfuração de poços de petróleo onshore Development of aqueous fluids with bentonite clay for drilling of onshore oil wells

    OpenAIRE

    R. C. A. M Nascimento; L. V. Amorim; L. N. L. Santana

    2010-01-01

    Devido aos grandes desafios encontrados na perfuração de poços, há a necessidade de se desenvolver fluidos com propriedades adequadas e capazes de atender todas as exigências da perfuração, como elevada capacidade de carreamento de sólidos e alta lubricidade, como também fluidos ambientalmente corretos. O grau de impacto dos fluidos de perfuração no meio ambiente depende especialmente do tipo de fluido utilizado, se de base aquosa, oleosa, sintética ou mesmo de base ar. Portanto, é de fundame...

  7. Assessment by X-ray diffraction the process of bentonite organophilization using a different quaternary ammonium salts; Avaliacao por difracao de raios X do processo de organofilizacao de uma bentonita utilizando diferentes sais quaternarios de amonio

    Energy Technology Data Exchange (ETDEWEB)

    Silva, L.A. da; Rosario, J.A. do; Lima, R.B.; Milioli, C.C.; Gusatti, M.; Linhares, R.H.; Kuhnen, N.C.; Riella, H.G., E-mail: lasqmc@hotmail.co [Universidade Federal de Santa Catarina (UFSC), Florianopolis, SC (Brazil). Campus Reitor Joao David Ferreira Lima; Cumbane, A.J. [Universidade Eduardo Mondlane (UEM), Maputo (Mozambique)

    2010-07-01

    The process was conducted in an organophilization Bentonite originated from the Company of Industrial Minerals of Mozambique Ltd. (Mimoc). The transformation of bentonite organophilic clay were performed in laboratory procedures that aim to mechanochemical exchange of Na{sup +} and Ca{sup 2+} from the interlayer space of clay minerals by cations of quaternary ammonium salts. In this study we used two types of salts, which are: the cetyl trimethyl ammonium chloride and alkyl dimethyl benzyl ammonium chloride at different concentrations (30, 50, 80, 100 meq/100 g clay). The natural bentonite and organophilic clay samples were characterized by X-ray diffraction (XRD) to obtain the mineralogical constituents and analysis phases of the increase in interlayer distance confirming the incorporation of quaternary ammonium salts in the structure of clays. (author)

  8. Tests for the characterization of bentonite used in the manufacture of clay geo synthetic barriers (GBR-C); Ensayos para la caracterizacion de las bentonitas utilizadas en la fabricacion de las barreras geosinteticas arcillosas (GBR-C)

    Energy Technology Data Exchange (ETDEWEB)

    Leiro, A.; Mateo, B.; Garcia, H.; Llorente, S.

    2011-07-01

    Bentonites are clays essentially composed of the smectite minerals. they are used in the manufacture of Clay Geosynthetic Barriers )GBR-C) which are low-permeability geosynthetic materials, forming part of the lining technologies and construction waterproofing systems. This article shows a series of testing to evaluate the quality of the bentonite for such use. Correlation between different testing has also been established in order to identify the most suitable ones for their characterization. (Author) 8 refs.

  9. Influence of the chemical modification and content of the clay on the mechanical properties of polypropylene and national bentonite composites; Influencia da modificacao quimica e do teor de argila nas propriedades mecanicas de compositos de polipropileno e bentonita nacional

    Energy Technology Data Exchange (ETDEWEB)

    Libano, Elaine V.D.G., E-mail: elainelibano@uezo.rj.gov.br [Centro Universitario Estadual da Zona Oeste - UEZO - RJ (Brazil); Pacheco, Elen B.A.V.; Visconte, Leila L.Y. [Universidade Federal do Rio de Janeiro - UFRJ, Instituto de Macromoleculas Professora Eloisa Mano - IMA, RJ (Brazil)

    2011-07-01

    The polypropylene/national clay composite was prepared by melt intercalation in a counter-rotating twin screw extruder, using bentonite as filler either in the natural (BENT) form or modified with the ammonium salt, cetyltrimethylammonium chloride (BENT-org). The clay was used in 1, 3 and 5%w. The influence of the modification and content of clay on the mechanical properties of this system was analysed. The analyses of infrared spectroscopy (FTIR) and X-ray diffraction (XRD) showed that clay organophilization did occur. The tensile modulus and the tensile strength at the yield point were not affected by chemical modification (BENT and BENT-org) or clay content. On the other hand, it was evidenced that the elongation at the yield point decreased with the addition of BENT and BENT-org to polypropylene. According to the thermogravimetric results, it was evidenced that the incorporation of clay into polypropylene improved thermal stability of the polymer in the composites with 5%w of BENT and 3 and 5%w of BENT-org. (author)

  10. Study of mechanical, rheological and thermal properties of nanocomposite HMSPP (high melt strength polypropylene) with Brazilian bentonite; Estudo das propriedades mecanicas, reologicas e termicas de nanocomposito de HMSPP (polipropileno com alta resistencia do fundido) com uma bentonita brasileira

    Energy Technology Data Exchange (ETDEWEB)

    Fermino, Danilo Marin

    2011-07-01

    This work concerns to the study of the mechanical, thermal and rheological behavior of the nano composite HMSPP - Polypropylene High Melt Strength (obtained at a dose of 12.5 kGy) and a bentonite clay Brazilian Paraiba, known as 'Chocolate' in concentrations of 5 and 10% by weight, comparison of to one American Clay, Cloisite 20A nanocomposite was done. Agent compatibilizer polypropylene-graft, known as maleic anhydride (PP-g-AM) was addict 3% concentration thought technique melt intercalation using a twin-screw extruder and the specimens were prepared by injection process. The mechanical behavior was evaluated by strength, flexural strength and impact tests. The thermal behavior was evaluated by the techniques of differential scanning calorimetry (DSC) and thermogravimetry (TGM). The rheological behavior was evaluated in rheometer. The morphology of the nanocomposites was studied by the technique of scanning electron microscopy (SEM). The organophilic bentonite and the nanocomposites were characterized by X-ray diffraction (XRD) and infrared (FTIR). (author)

  11. Study and development of nanocomposites PBT/bentonite clay treated by ionizing radiation: preparation and characterization; Estudo e desenvolvimento de nanocompositos PBT/argila bentonita tratados por radiacao ionizante: preparacao e caracterizacao

    Energy Technology Data Exchange (ETDEWEB)

    Sartori, Mariana do Nascimento

    2014-07-01

    This work describes the preparation and characterization of composites based on poly (butylene terephthalate) - PBT and brazilian modified clay prepared by the melt intercalation. PBT nanocomposites with 3 and 5 % by weight of organically modified clay, by the addition of a quaternary ammonium salt, were prepared by extrusion using a twin-screw extruder machine. After the extrusion process, the materials were injected to obtain specimens tests samples for the characterization tests. Part of the specimens samples were irradiated using an electron beam accelerator with 1.5 MeV at room temperature in the presence of air. Samples of pure PBT and irradiated and non-irradiated nanocomposites were characterized by mechanical tests of tensile, flexural and impact, heat distortion temperature (HDT), X - ray diffraction (XRD), scanning electron microscopy (SEM), melt flow index (MFI) thermogravimetry (TG) and differential scanning calorimetry (DSC) and the correlation between the properties was discussed. The results showed that the addition of clay, in both percentages, promoted an increase greater than 50 % in tensile strength at break and a gain of around 35% in heat distortion temperature when compared to the pure polymer. The treatment with ionizing radiation of electron beam at the doses used in this study showed no significant changes in material properties. (author)

  12. Study of influence of content organoclay on mechanical properties of propylene and bentonite clay nanocomposites; Estudo da influencia do teor de argila organofilica nas propriedades mecanicas de nanocompositos de polipropileno e argila bentonita

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-07-01

    In this work we studied activated organoclay nanocomposites in pilot scale, obtained by physical mixing in twin screw extruder co-rotating. The organophilic clay content included in the formulation of these compounds ranged from 2 to 6% by weight. The clays were characterized using the techniques of x-ray. Systems PP / clay were characterized by tensile test, flexural and impact strength. The results indicated that there was no loss of mechanical properties and thermo-mechanical properties of the nanocomposite obtained. (author)

  13. Study on the mechanical properties of a HMS-PP nanocomposite with a Brazilian bentonite; Estudo das propriedades mecanicas de um nanocomposito de HMS-PP com uma bentonita brasileira

    Energy Technology Data Exchange (ETDEWEB)

    Fermino, D.M.; Parra, D.F.; Lugao, A.B.; Oliani, W.L., E-mail: mfermino@usp.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Valenzuela-Diaz, F.R. [Universidade de Sao Paulo (USP), SP (Brazil). Escola Politecnica. Dept. de Engenharia Metalurgica e de Materiais

    2010-07-01

    This work concerns to the study of the mechanical behavior of the nanocomposite HMSPP - Polypropylene High Melt Strength (obtained at a dose of 12.5 kGy) and a bentonite clay Brazilian Paraiba (PB), known as 'Chocolate' in concentrations of 5 and 10% by weight, comparison of to one American Clay, cloisite 20A nanocomposite was done. Agent compatibilizer polypropylene-graft, known as maleic anhydride (PP-g-AM) was addict 3% concentration thought technique melt intercalation using a twin-screw extruder and the specimens were prepared by injection process. The mechanical behavior was evaluated by strength, flexural strength and impact tests. The morphology of the nanocomposites was studied by the technique of Scanning Electron Microscopy (SEM), while the organophilic bentonite and nanocomposites were characterized by X-ray diffraction (XRD) and infrared (FTIR). (author)

  14. Validez Convergente de la Version Espanola Preliminar del Child Abuse Potential Inventory: Depresion y Aduste Marital (Convergent Validity of the Preliminary Spanish Version of the Child Abuse Potential Inventory: Depression and Marital Adjustment).

    Science.gov (United States)

    Arruabarrena, M. Ignacia; de Paul, Joaquin

    1992-01-01

    "Convergent validity" of preliminary Spanish version of Child Abuse Potential (CAP) Inventory was studied. CAP uses ecological-systemic model of child maltreatment to evaluate individual, family, and social factors facilitating physical child abuse. Depression and marital adjustment were measured in three groups of mothers. Results found…

  15. Mechanical characterization of a reduced activation 9 Cr ferritic/martensitic steel of spanish production; Caracterizacion mecanica de un acero ferritico/martenitico de activacion reducida de produccion espanola

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, D.; Serrano, M.

    2012-07-01

    This paper shows the first results concerning the characterization of two heats of a reduced activation 9 Cr ferritic/martensitic steel (RAFM) made in Spain, called AF1B and AF2A. The results of this characterization are compared with their European counterparts, EUROFER97-2, which was chosen as reference material. All activities described were performed in the Structural Materials Unit of CIEMAT, within the national project TECNO-FUS CONSOLIDER INGENIO.The two Spanish heats have the same production process and heat treatment. Both heats have a similar tensile behaviour similar to EUROFER97-2, but on the other hand impact properties are lower. The microstructure of AF1B reveals large biphasic inclusions that affecting its mechanical properties, especially the impact properties. AF2A casting was free of these inclusions. (Author) 24 refs.

  16. 15 years of Spanish participation in the international projects of R and D coal technology coordinated by OCICARBON; 15 Anos de Participacion Espanola en los foros Internacionales de I+D Tecnologico del Carbon coordinados por OCICARBON

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    As fulfillment of strategy objectives, OCICARBON ( the Spanish Management Association for Coal Research and Development Projects) has maintained a strong link with European and International entities, devoted to coal research and development activities. As consequence of these collaborations, it has been reached uncountable economical and technological benefits, from the projects carried out by Spanish industries and technological entities, under the European Programmes umbrella. In this summary report, it is informed about how the co-ordination of national and international entities, was organised and structured; and the national results, obtained as consequence of the activities carried out by OCICARBON. (Author)

  17. Spanish participation in the Benchmark of the OECD of CFDs applied to nuclear safety: the test of Tee Junction; Participacion espanola en el Benchmark de la OCDE de CFDS aplicados a Seguridad Nuclear: el test de la Tee Junction

    Energy Technology Data Exchange (ETDEWEB)

    Abdelaziz Essa, M. A.; Chiva, S.; Munoz-Cobo, J. L.

    2011-07-01

    In this paper we show the main results obtained by the groups of the Universities UPV and UJI (GITH-Inter-Universitary Group on Thermal-Hidraulics), in the modeling of the OCDE Benchmark on the T-Junction performed during the year 2010. This benchmark consisted in predicting, using CFD codes the velocity and temperature distributions downstream the junction. Also was considered a important issue the prediction of the velocity and temperature fluctuations, especially the Power Spectral density of the temperature fluctuations. The results obtained in the Benchmark by the GITH group were very good.

  18. Participation of CIEMAT in the 29 Annual meeting of the Spanish Nuclear Society. Zaragoza 1,2 y 3 October 2003; Participacion del CIEMAT en la 29 Reunion Anual de la Sociedad Nuclear Espanola

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-07-01

    The book assembles the paper of researches of CIEMAT during the 29th annual meeting of Spanish Nuclear Society. The paper were presented during the following sessions : 1. Nuclear fuel. 2. R and D materials. 3.Operation and maintenance. Lifetime. 4.- R and D and T participation and transmutation.5. Environment. 6. Radioactive wastes and dismantling. 7. Nuclear safety. 8. Nuclear law.

  19. Development of database for spent fuel and special waste from the Spanish nuclear power plants; Desarrollo de la base de datos para el combustible gastado y residuos especiales de las centrales nucleares espanolas

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez Gandal, R.; Rodriguez Gomez, M. A.; Serrano, G.; Lopez Alvarez, G.

    2013-07-01

    GNF Engineering is developing together with ENRESA and with the UNESA participation, the spent fuel and high activity radioactive waste data base of Spanish nuclear power plants. In the article is detailed how this strategic project essential to carry out the CTS (centralized temporary storage) future management and other project which could be emerged is being dealing with, This data base will serve as mechanics of relationship between ENRESA and Spanish NPPS, covering the expected necessary information to deal with mentioned future management of spent fuel and high activity radioactive waste. (Author)

  20. III Joint Congress of the Spanish Societies of Medical Physics and Radiation Protection, 18-21 Jun 2013, Caceres Spain; III Congreso Conjunto Sociedad Espanola Fisica Medica y Proteccion Radiologica, 18-21 Junio 2013, Caceres, Espana

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-07-01

    This congress offers the opportunity to see the state of the art in the field of medical physics and radiation protection from a scientific and technical. this work requires a comprehensive assessment and coordination to achieve content that represent a high percentage of current lines of work and research in our country. (Author)

  1. Eco-innovation an evolution of innovation? Empirical analysis at the Spanish tile ceramic industry; Eco-innovacion, una evolucion de la innovacion? Analisis empirico en la industria ceramica espanola

    Energy Technology Data Exchange (ETDEWEB)

    Segarra-Ona, M.; Peiro-Signes, A.; Miret-Pastor, L.; Albors-Garrigos, J.

    2011-07-01

    Innovation and sustainable development are considered to be economic drivers and crucial in fixing competitive position of companies. Eco-innovation, known as a synergic relation among both concepts must be an element to consider when designing the company's strategy. The objective of this paper is to analyze which are the variables that determine that innovative companies go beyond and consider the improvement of their environmental impact as an output when developing innovating activities. This research considers firms belonging to the Spanish tile industry. Data has been provided by PITEC Database. The paper identifies the moderating factors that influence the eco-innovative behavior of firms. (Author)

  2. Control and Data Acquisitions System for the spanish Beamline (BM25) at the ESRF; Sistema de Control y Acquisicion de Datos para la Linea Espanola (BN25) del ESRF

    Energy Technology Data Exchange (ETDEWEB)

    Pereira Gonzalez, A.; Olalla Garcia, C.; Sanchez Sanz, J.; Castro, G. R.

    2005-07-01

    A new control and data acquisition system has been developed for BM25 Spanish Line at the ESRF. The system is based in VMEbus, Motorola PreP architecture and Linux Operating System and it's linked to a local ETHERNET network which provides the way of communicate with the servers (PC workstations). In these computers, the data are available for general usage in order to analyze them. The data acquisition consists of many channels connected to the VME crates mainly, independent between them, and fully programmable by drivers, CLUI's and GUI's interfaces, and a set of independent systems (embedded ones, PLCs, others) controlling the security aspects. This report is described in terms of their architecture, their electronic system to the process hard ware and the functionality and the application development facilities they provide using the software and the data acquisition. (Author) 18 refs.

  3. The tourist area life cycle: its application to the Spanish Costa del Sol and its environment; El ciclo de vida de un area turistica: su aplicacion a la Costa del Sol espanola y su medio ambiente

    Energy Technology Data Exchange (ETDEWEB)

    Perez, P.L.

    2012-07-01

    The Theory of a Tourism Area Life Cycle, formulated by Richard W. Butler, has seven phases of evolution, which are applied to the tourism destination. In this concept, the location is treated as if it were a living organism. That is to say, it is born, it flourishes, if it develops an illness, it may die or in accordance with its particular reality it may be reborn. This theory may also stipulate the sustainability of a tourism destination, as its carrying capacity, or multiple capacities, may only be analyzed within its position in the cycle. This is the first time the theory has been applied to the Spanish Costa del Sol and it is determined, that this destination does not fit completely in any one phase. Therefore, it is necessary to create its own series, by designating it, as that of pre-stagnation. Also, it is concluded, that, at present, given the distortion between its aquatic environmental carrying capacity, due to the consumption of this resource, by the golf courses and its consequential negative social carrying capacity, it is an unsustainable tourism destination. Though, it does have the capacity to overcome this situation, by recycling the water used for irrigating these courses. (Author)

  4. Patterns of technology diffusion Spanish. An identification through the information contained in patents; Pautas de difusion de la tecnologia espanola. Una identificacion a traves de la informacion contenida en las patentes

    Energy Technology Data Exchange (ETDEWEB)

    Acosta Sero, M.; Coronado Guerrero, D.; Fernandez Perez, A. M.

    2010-07-01

    This paper aims to answer the following research questions: What countries are the geographical destinations of technological knowledge generated by Spanish inventors? What sectors take advantage of the technological knowledge produced in a different sector? What are the characteristics of the patented knowledge more intensively diffused? Our methodology rests on a biblio metric analysis of patent granted by the Patent Office from the US (USPTO) to Spanish inventors. We found some relevant aspects that might be useful to think about technological policy favouring knowledge diffusion. (Author) 27 refs.

  5. Technology and industrialization in Spanish economy from 1950 to 1960: the patents as technological activity indicators; Tecnologia e industrializacion en la economia espanola de 1950 a 1960: Nueva evidencia a partir de datos de patentes

    Energy Technology Data Exchange (ETDEWEB)

    Hidalgo Nuchera, A.; Molero Zayas, J.; Granda Gayo, I.

    2007-07-01

    The goal of this research is to study the innovative activity developed in the fifties by the Spanish industry focussing on the foreign technology incorporated in the activity of several industrial sectors. The structure of innovation in each sector has been characterized by using patents as technological activity indicators. The data of patents registered in Spain belonging to the 1950-1960 period have been obtained taking into account the research developed by the Department of Business Administration of the Universidad Politecnica de Madrid through a subsidy granted by the Spanish Patent Office. (Author)

  6. The evolution of energy costs and their effect on the competitiveness of Spanish industry; La evolucion de los costes energeticos y su efecto en la competitividad de la industria espanola

    Energy Technology Data Exchange (ETDEWEB)

    Arocena, P.; Diaz, A. C.

    2015-07-01

    This paper analyzes the role of energy costs in the Spanish manufacturing and its evolution during the period 2000-2010. We carry out a descriptive analysis to firstly, determine the share of energy expenses on total operating expenses and personnel costs, and compare it with that registered in other European countries. Secondly, we analyze the evolution of the energy expenditure in relation to the output value created throughout the decade 2000-2010 and decompose such variation into a price effect and a quantity effect. (Author)

  7. Experimental study of the transport of HTO, {sup 3}6Cl and {sup 1}37Cs through barriers of bentonite and granite; Estudio experimental del transporte de HTO, {sup 3}6Cl y {sup 1}37Cs a traves de barreras de bentonita y granito

    Energy Technology Data Exchange (ETDEWEB)

    Mingarro, M.; Garcia-Gutierrez, M.; Morejon, J.; Missana, T.; Gil, P.

    2013-07-01

    The evaluation of the behavior of the engineered (bentonite) and natural (granite) barrier of a deep geological repository of high level radioactive waste, needs the knowledge of radionuclide migration and retention processes under conditions as similar as possible to the real ones. In CIEMAT a large-scale experiment has been designed with the objective of studying diffusive transport at the bentonite/granite interface of a geological repository in crystalline rock. The diffusion of three tracers has been analyzed: HTO (as conservative and neural element); Cl (as conservative anionic element) and Cs (as conservative cationic element). It was observed that cesium disappeared very fast from the water deposit, due to its strong retention on bentonite. On the other hand, HTO and Cl, disappeared much slower and could be finally detected in the granite at several centimeters from the original source.

  8. Simulación del Transporte deTrazadores en Medios Porosos: Aplicación al Caso de Arcillas

    OpenAIRE

    Brú Espino, Antonio; Casero Díaz-Cano, David

    2001-01-01

    Presentamos un marco para describir el transporte de trazadores en medios heterogéneos, tales como los medios porosos tales como las bentonitas. En estos medios, la aproximación de campo medio no es válida ya que exiten ciertas restricciones geométricas y el transporte es anómalo.

  9. Maintenance and improvement of thermal hydraulic system codes using results of OCDE experiments (PKL, Rosa, Atlas) and application to Spanish Nuclear power plants. Camp-Spain project; Mejora y mantenimiento de codigos termohidraulicos de sistema de base a resultados de los experimentos OECD (PKL, ROSA y ATLAS) y su aplicacion a plantas espanolas, proyecto Camp-Espana

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez, M.; Perez, J.; Martorell, S.; Carlos, S.; Villanueva, J. F.; Sanchez, F.; Queral, C.; Rebollo, M. J.; Rivas-Lewicky, J.; Verdu, G.; Gallardo, S.; Miro, R.; Querol, A.; Munoz-Cobo, J. L.; Escriva, A.; Berna, C.; Reventos, F.; Freixa, J.; Martinez, V.

    2016-08-01

    CSN involvement in different international NEA experimental TH programmes has outlined the scope for a new period of CAMP-Espana activities, currently focused on the: -Analysis, simulation and investigation of specific safety aspects of PKL3/OECD and ATLAS/OECD experiments. -Analysis of applicability and/or extension of the results in these projects to the safety, operation or availability of the Spanish nuclear power plants. Both objective are carried out by simulating experiments and plant application with the last available versions of NRC TH codes (RELAP5 or TRACE). A CAMP in kind contribution (NUREG/IA) is aimed as final result of both types of analyses. Five different national research groups (from Technical Universities of Madrid, Valencia and Cataluna) ate carrying out the development of these activities. (Author)

  10. Thermal energy consumption and carbon dioxide emissions in ceramic tile manufacture - Analysis of the Spanish and Brazilian industries; Consumo de energia termica y emisiones de dioxido de carbono en la fabricacion de baldosas ceramicas Analisis de las industrias Espanola y Brasilena

    Energy Technology Data Exchange (ETDEWEB)

    Monfort, E.; Mezquita, A.; Vaquer, E.; Mallol, G.; Alves, H. J.; Boschi, A. O.

    2012-11-01

    Spain and Brazil are two of the world's biggest ceramic tile producers. The tile manufacturing process consumes a great quantity of thermal energy that, in these two countries, is mainly obtained from natural gas combustion, which entails CO{sub 2} emission, a greenhouse gas. This study presents a comparative analysis of the thermal energy consumption and CO{sub 2} emissions in the ceramic tile manufacturing process in Spain and Brazil, in terms of the different production technologies and different products made. The energy consumption and CO{sub 2} emissions in ceramic tile manufacture by the wet process are very similar in both countries. In the dry process used in Brazil, less thermal energy is consumed and less CO{sub 2} is emitted than in the wet process, but it is a process that is only used in manufacturing one particular type of product, which exhibits certain technical limitations. While in Spain the use of cogeneration systems in spray-dryers improves significantly the global energy efficiency. The average energy consumption in the different process stages, in both countries, lies within the range indicated in the Reference Document on Best Available Techniques in the Ceramic Manufacturing Industry (BREF of the Ceramic Manufacturing Industry) of the European Union. (Author) 14 refs.

  11. Is it necessary to adopt measures in occupational radiological protection in Spanish NORM industries devoted to the processing of minerals and raw materials; Es necesario adoptar medidas de proteccion radiologica ocupacionales en algunas industrias NORM espanolas dedicadas al procesdado de minerales o materias primas?

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Tenorio, R.; Bolivar, J. P.

    2010-07-01

    In this work it is documented why is quite limited the number os Spanish NORM industries devoted to the processing of minerals and/or raw materials where it is necessary to adopt occupational radiological protection countermeasures. These countermeasures are coincident in some cases with OHS countermeasures historically applied in the affected industries and in most cases can be only needed in working situations associated with maintenance operations. (Author) 6 refs.

  12. Realization of R and D and its composition in the Spanish manufacturing company, differentiated analysis of the determinants of research and development; Realizacion de I+D y su composiscion en la empresa manufacturera espanola. Analisis de los determinantes diferenciados de la investigacion y el desarrollo

    Energy Technology Data Exchange (ETDEWEB)

    Barge-Gil, A.; Lopez, A.

    2012-07-01

    The aim of this paper is to explore the differentiated effect of classical R and D determinants (size, technological opportunity, demand pull and appropriability) on research and development. First, we briefly expose the differences between research and development activities. Second, we analyze different issues related to R and D performance by Spanish manufacturing firms. We find that less than half of the firms with R and D perform both research and development. With respect to the determinants, we find that technological opportunity and industry level of appropriability have a higher effect on innovation activities (compared with the effect on development activities). (Author) 40 refs.

  13. Social Cooperability: The case of mayor in the Czech Republic, Poland and Slovakia

    Czech Academy of Sciences Publication Activity Database

    Vajdová, Zdenka

    Valencia : Sociedad Espanola de Sistemas Generales, 1999 - (Rerrer, L.), s. 403-410 ISBN 84-7795-233-7. [Systems Science European Congress /4./. Valencia (IT), 22.09.1999-24.09.1999] R&D Projects: GA AV ČR IAA8028703 Subject RIV: AO - Sociology, Demography

  14. Third Dialogue Between Chinese and Spanish Mayors Held in Taiyuan

    Institute of Scientific and Technical Information of China (English)

    Ni; Yuan

    2014-01-01

    <正>The Third Dialogue between Chinese and Spanish Mayors sponsored by the CPAFFC,the Federation of Spanish Municipalities and Provinces(Federacion Espanola de Municipios y Provincias-FEMP)and the Shanxi Provincial People’s Government and hosted by the Foreign and Overseas Chinese Affairs Office of the Shanxi Provincial Government was held in Taiyuan on September 16,2013.

  15. Estudio por Microespectroscopía Raman Confocal de Mezclas PP/PE praparadas por Moldeo por compresión y Moldeo por inyección

    Czech Academy of Sciences Publication Activity Database

    López-Quintana, S.; Schmidt, Pavel; Pastor, J. M.; Merino, J. C.; Raab, Miroslav

    San Sebastian : Sociedades Espanolas de Física y Química , 1999. s. 152. [Nuevas perspectivas en polimeros. 07.09.1999-09.09.1999, San Sebastian] R&D Projects: GA ČR GA106/97/1071 Subject RIV: CD - Macromolecular Chemistry

  16. "Sometimes I Am Spanish and Sometimes Not": A Study of the Identity and Integration of Spanish Muslim Women

    Science.gov (United States)

    Sibai, Salam Adlbi

    2010-01-01

    This article reports part of a wider investigation which is still being developed and analyzes in depth the lives of female university students who are both Spanish and Muslim. The first part of this research was published in the "Revista Espanola de Educacion Comparada," where the results of the study in Madrid are presented. Here, the second…

  17. Spanish Bilateral Initiatives for Education in Latin America

    Science.gov (United States)

    Cortina, Regina; Sanchez, Maria Teresa

    2007-01-01

    The research presented in this article concerns la Agencia Espanola de Cooperacion Internacional (Spanish Agency for International Cooperation--AECI) and its growing presence in Latin America since the late 1990s. The aim is to evaluate the transformative potential that bilateral funding can have on educational reform in the region. The article…

  18. Special Report: Conflicting Data on Spanish Intransitive Verbs in Two Leading Dictionaries.

    Science.gov (United States)

    Teschner, Richard V.; Flemming, Jennifer

    1996-01-01

    Presents a conflation of and a comparison between the 1,646 verbs the Royal Academy's "Diccionario de la lengua espanola" (Dictionary of the Spanish Language) classifies as solely or partly intransitive and the 1,382 verbs that are so classified by the "Pequeno Larousse ilustrado" (Illustrated Larousse Small Dictionary). Considerable disagreement…

  19. The Social Significance and Value Dimension of Current Mexican American Dialectal Spanish. A Glossary for the Human Service Professions. Part II.

    Science.gov (United States)

    Gomez, Ernesto; Cerda, Gilberto

    Results of a study documenting the Mexican American's unique Spanish dialectal expressions used in the barrios of San Antonio, Texas, and its surrounding areas are presented. The expressions included are those which were not recorded in the "Diccionario de la Real Academia Espanola" (19th Edition) or which were recorded therein but with different…

  20. A comparison of national and international megavoltage calibration protocols

    International Nuclear Information System (INIS)

    Almond lists, describes and compares the following radiation therapy dosimetry protocols and standards of the following groups: Deutsches Institut fuer Normung (DIN), Nordic Association of Clinical Physics (NACP), National Council on Radiation Protection and Measurements (NCRP), Hospital Physicists Association (HPA), American Association of Physics in Medicine (AAPM), Bureau National de Metrologie (BNM), and the Sociedad Espanola de fisica Medica (SEFM)

  1. Retención de Zn, Cd y Pb por sólidos arcillosos

    OpenAIRE

    Rueda, Mónica

    2015-01-01

    Los sólidos arcillosos son recursos minerales no metálicos explotados debido a la demanda de numerosas industrias. Sus principales constituyentes son los denominados minerales arcillosos dentro de los cuales se encuentran la caolinita, esmectita e illita, entre otros. No obstante, entre los distintos argilominerales se destaca la esmectita por su capacidad adsorbente en general. La bentonita es una roca que contiene mayoritariamente este grupo de mineral arcilloso y en las tobas el grado de a...

  2. Comportamiento geoquímico de barreras arcillosas: transformaciones hidrotermales en esmectitas alumínicas

    Directory of Open Access Journals (Sweden)

    Cuadros, F. J.

    1993-08-01

    Full Text Available The use of bentonite barriers in radiactive waste repositories is conditioned by its transformation into illite, due to the influence of temperature and solutions in the canister vicinity. This reaction is known in burial diagenesis and hydrothermal alterations, but its mechanism is not yet well stablished. A preliminary study on spanish bentonites shows that important variations exist in the chemical solutions in contact with bentonites in a hydrothermal environment.El uso de bentonitas como barrera en almacenamientos de residuos radiactivos viene condicionado por su posible transformación en ilita debido a la influencia de la temperatura y de las soluciones cercanas al contenedor. Esta reacción se conoce en zonas de diagénesis de enterramiento y en áreas hidrotermales, pero su mecanismo no está todavía bien establecido. En un estudio preliminar realizado sobre bentonitas españolas se ha encontrado que existen variaciones importantes en el quimismo de las soluciones en contacto con bentonitas en ambiente hidrotermal.

  3. Caracterização estrutural de argilas bentoníticas nacional e importada: antes e após o processo de organofilização para utilização como nanocargas Structural characterization of Brazilian and imported bentonitic clays: before and after the process of organophilization for utilization as nanofiller

    Directory of Open Access Journals (Sweden)

    I. F. Leite

    2008-09-01

    Full Text Available Foi utilizada uma bentonita natural codificada como ASCN oriunda da Bentonit União Nordeste, PB sob forma de pó com granulometria inferior a 0,074 µm. A bentonita ASCN foi modificada organicamente através de troca iônica com o sal brometo de cetil trimetil amônio Cetremide e denominada ASCM. Para obter bentonitas organofílicas, inicialmente, dispersões aquosas de bentonita/sal Cetremide foram mantidas sob agitação mecânica constante a aproximadamente 80 °C por 30 min. Em seguida o sistema foi mantido em repouso por 24 h, sendo então lavado e filtrados os insumos. Por fim os materiais foram secos a 60 °C e então desagregados e passados em malha 200 para serem caracterizados. Como parâmetro de comparação foi utilizada uma bentonita importada organofílica Cloisite 30 B (Southern Clay Products, Texas, EUA. Ambas argilas foram caracterizadas estruturalmente por análise química, capacidade de troca de cátions, espectroscopia no infravermelho (FTIR, difração de raios X e análise termogravimétrica. A análise química mostrou a presença de óxidos característicos da estrutura do aluminossilicato e eventual redução na maioria dos óxidos metálicos quando as bentonitas foram organofilizadas, ASCM e Cloisite 30B, característico do processo de troca dos cátions metálicos por moléculas do sal orgânico. Mediante os espectros de FTIR verifica-se a presença de bandas características das moléculas do sal nas bentonitas e através da análise de difração de raios X observa-se um aumento no espaçamento basal pela inserção das cadeias do sal entre as lamelas da bentonita, confirmando assim a obtenção de bentonitas organofílicas. A curva termogravimétrica das bentonitas organofílicas indicou que a bentonita Cloisite 30 B apresentou-se mais estável termicamente que a bentonita ASCM.A natural bentonite coded as ASCN supplied by Bentonit União Nordeste from Paraíba, Brazil in powder form with particle size smaller

  4. ¿Como Conseguir que Crezcan la Productividad y el Empleo, y Disminuya el Desequilibrio Exterior?

    OpenAIRE

    Rafael Domenech; Juan Ramon Garcia Lopez

    2010-01-01

    Tras la crisis economica iniciada en 2008, el declive economico de sectores como el de la inversion residencial ha puesto de manifiesto que la economia espanola necesita reorientar su actividad productiva hacia sectores con mayor potencial de crecimiento futuro y de creacion de empleo, como aquellos orientados a la demanda exterior. Este cambio exige acelerar la implementacion de politicas economicas que incentiven la demanda de empleo, la competitividad de las empresas, su internacionalizaci...

  5. Small scale preparative electrolysis in sonoelectrochemical cell optimized with the help of simulation of ultrasonic intensity distribution

    Czech Academy of Sciences Publication Activity Database

    Klíma, Jiří; Ludvík, Jiří; Urban, Jiří; González-Garcia, J.; Sáez, V.; Frias-Ferrer, A.

    Madrid : Sociedad Espanola de Acústica, 2007 - (Calvo-Manzano, A.; Pérez-López, A.; Santiago, S.), 43.55/1/-43.55/5/ ISBN 84-87985-12-2 R&D Projects: GA MŠk 1P05OC074 Institutional research plan: CEZ:AV0Z40400503 Keywords : electrochemistry * electrolysis * ultrasonic intensity distribution Subject RIV: CG - Electrochemistry http://www.sea-acustica.es/WEB_ICA_07

  6. Is Einstein Still Right?

    CERN Document Server

    Yunes, Nicolas

    2015-01-01

    This is an article commissioned by the Spanish Physics Magazine ("Revista Espa\\~nola de F\\'isica") for the Centennial Anniversary of the discovery of General Relativity. The article reviews experimental and observational efforts to test Einstein's theory of General Relativity in a variety of scenarios (from the Solar System to binary pulsars, from the Sag A* to binary black hole and neutron star coalescences).

  7. Spanish Electric Sector Nuclear R and D Model

    International Nuclear Information System (INIS)

    This paper presents the R and D model that, based on the experience gained and lessons learned in nearly forty years of nuclear power use in Spain, is Promoted by the Spanish Electricity Sector for the nuclear R and D activities it develops in a coordinated manner in the frame of the Nuclear Energy Committee of the Association Espanola de la Industria Electrica (UNESA). (Author)

  8. Forestaciones con encina y alcornoque en el area de la dehesa en el marco del Reglamento (CEE) 2080/92 (1993-2000)

    OpenAIRE

    Ovando, Paola; Campos, Pablo; Montero, Gregorio

    2007-01-01

    La Union Europea adopta en el ano 1992 una serie de medidas de acompanamiento a la reforma de la politica agraria comun. la politica de abandono de tierras agricolas dedicadas a cultivos excedentarios fue incentivada mediante ayudas a su forestacion, reguladas por el REglamento 2080/1992. Esta intervencion publica ha tenido en el area de la dehesa espanola una influencia favorable a la expansion de sus dos especies forestales mas emblematicas: la encina y el alcornoque. La superficie forestad...

  9. Caracterización preliminar de las zeolitas del yacimiento "Los Murcianos" Almería

    OpenAIRE

    Calvo Pérez, Benjamín; Costafreda Mustelier, Jorge Luis; Estévez Fernández, Esteban

    2005-01-01

    En un ambiente geológico volcánico, compuesto por andesitas piroxénicas, brechas, tobas, piroclastos de composición andesítica y dacítica, alteradas en gran parte por las soluciones hidrotermales, se encuentra un depósito de zeolita tipo mordenita, explotado desde hace varios años como bentonita. El reciente hallazgo de la zeolita con un contenido de mordenita de hasta 57 %, ha cambiado radicalmente la visión genética del yacimiento y con ello se han abierto nuevas posibilidade...

  10. Obtención, caracterización y estudio de la estabilidad térmica de arcillas pilarizadas de aluminio

    OpenAIRE

    Tzayhrí Gallardo; Guillermo Osorio; Sofía Arrellano

    2000-01-01

    En el presente trabajo se estudiaron las propiedades de estabilidad de tres arcillas pilarizadas de aluminio (Al-PILCs) sintetizadas a partir de una bentonita, variando algunos parámetros en su preparación. Los estudios de hinchamiento y de difracción de rayos X mostraron que se requiere una relación mayor de 1.5 mmol de Al/g de arcilla, para efectuar la pilarización, siendo la relación de 6.0 mmol Al/g la que propició un producto con mejor acomodamiento cara-cara. Las Al-PILCs fueron es...

  11. Caracterización de la Arcilla como Barrera de Ingeniería para la Migración de Contaminantes: Propiedades Térmicas, Hidráulicas y Mecánicas

    OpenAIRE

    Brú Espino, Antonio; Casero Díaz-Cano, David

    2001-01-01

    En este trabajo caracterizamos la estructura de una arcilla, concretamente la bentonita. Nuestro propósito es realzar la importancia que la heterogeneidad de la estructura del medio tiene en los procesos de transporte.La aleatoriedad de los tamaños de poros produce un transporte anómalo de los contaminantes. Analizamos los resultados de la porosimetría de mercurio y los comparamos con simulaciones, hallando que la distribución de los tamaños de los poros sigue una ley de potencias

  12. Inmovilización de dos lipasas para su aplicación en el pretratamiento de aguas residuales de la industria láctea = immobilization of two lipases for use in pretreatment of wastewater from dairy industry

    OpenAIRE

    Díaz Ramos, Margarita

    2012-01-01

    En este trabajo se preparó un sistema biocatalítico con un buen desempeño en la hidrólisis de aguas residuales con alto contenido de grasas como pretratamiento del tratamiento biológico anaerobio o aerobio de esta clase de aguas residuales. Se inmovilizaron dos clases de lipasas provenientes de los hongos, Candida rugosa (Tipo VII de Sigma Chemical Co.) y Rhizopus oryzae (Fluka) en quitina y bentonita modificada. La quitina se produjo a partir de los caparazones de jaibas mediante...

  13. Procedimiento de regeneración de salmueras de aceitunas y otros productos vegetales para su utilización posterior

    OpenAIRE

    Brenes Balbuena, Manuel; Sánchez Roldán, Francisco; García García, Pedro; Garrido Fernández, A.

    1990-01-01

    El procedimiento de regeneración de salmueras de aceitunas y otros productos vegetales para su utilización posterior corrige el pH a las salmueras previamente a su tratamiento con carbón activo. Después se decanta este absorbente junto a gran parte de los sólidos en suspensión gracias a la adición de una suspensión de bentonita, se filtra seguidamente con la ayuda de tierras diatomeas y se conserva la solución adicionando ácido ascórbico u otros antioxidantes y manteniendo condiciones a...

  14. Naturaleza de las esmectitas del yacimiento de Morrón de Mateo (Cabo de Gata, Almería) en relación con la roca madre y/o con los procesos posteriores a la bentonitización (Implicaciones analógicas para la barrera de ingeniería de un almacenamiento de residuos radiactivos)

    OpenAIRE

    Pelayo Bayón, Marta; Pérez del Villar Guillén, L.; García Romero, Emilia

    2009-01-01

    El yacimiento de bentonita Morrón de Mateo se está estudiando como análogo natural del efecto térmico y geoquímico que puede esperarse en la barrera de arcilla de un Almacenamiento Geológico Profundo (AGP) de residuos radiactivos, debido al decaimiento radiactivo de los productos de fisión y del efecto de la oxidación del contenedor. El yacimiento presenta un domo volcánico que intruyó a través de una formación volcanosedimentaria formada por capas de material piroclástico, epi...

  15. Thermo-Hydro-Mechanical Behaviour of expansive clays under high temperatures

    OpenAIRE

    Jacinto, Abel Carlos

    2010-01-01

    Esta Tesis presenta los resultados de la investigación desarrollada en el marco del proyecto Temperature Buffer Test (TBT). El objetivo general de este proyecto es investigar el desempeño de la bentonita usada en barreras de ingeniería bajo la acción de las altas temperaturas que se esperan alrededor de los contenedores con residuos vitrificados. Dentro del proyecto, se ha implementado un ensayo de campo a escala real que simula el almacenamiento de residuos radioactivos de alta actividad. Ad...

  16. Caracterización del comportamiento termo-hidro-mecánico de arcillas expansivas

    OpenAIRE

    Pintado Llurba, Xavier

    2002-01-01

    En los últimos años, se ha estado analizando la posibilidad de almacenar los residuos radioactivos de alta actividad procedentes del combustible gastado procedente de las centrales nucleares de producción de energía eléctrica, en galerías excavadas en roca. Entre la cápsula que contiene el residuo radioactivo y la roca, se estudia colocar una arcilla expansiva tipo bentonita (proyecto FEBEX; Alonso et al., 2000). Esta tesis se ha concentrado en el estudio y caracterización termo-hidro-mecánic...

  17. Influência da hidrociclonagem e da secagem por spray dryer nas propriedades reológicas de argilas bentoníticas

    OpenAIRE

    V. C. Marques; H. C. Silva; A. M. T. Rodrigues; J. M. Cartaxo; R. R. Menezes; H. S. Ferreiral

    2015-01-01

    ResumoA exploração desordenada ao longo dos anos das argilas bentoníticas do município de Boa Vista, PB, resultou no esgotamento das variedades nobres. Assim, o que existe atualmente são bentonitas com elevado percentual de minerais acessórios, elementos contaminantes a exemplo do quartzo, os quais influem negativamente nas propriedades reológicas das dispersões. O presente trabalho propõe concentrar dispersões dessas argilas pouco nobres pela operação de hidrociclonagem e posterior secagem p...

  18. Influência da adição de uma carga nanoparticulada no desempenho de compósitos poliuretano/fibra de juta Influence of a nanoparticulate filler addition on the mechanical properties of polyurethane/jute fiber composites

    OpenAIRE

    José R. A. Neto; Laura H. Carvalho; Edcleide M. Araújo

    2007-01-01

    Neste trabalho as propriedades mecânicas de um compósito, formado a partir de uma matriz de poliuretano derivado do óleo de mamona e reforçada por um tecido tramado de juta, foram avaliadas. O efeito da adição de pequenos teores de bentonita cálcica e sódica sobre as propriedades mecânicas da matriz de poliuretano e de compósitos poliuretano/juta também foi investigado. Os resultados indicam que a incorporação de fibra de juta à matriz poliuretana promoveu melhora significativa nas propriedad...

  19. Electronic properties of molecular solids: the peculiar case of solid Picene

    OpenAIRE

    Roth F.; Gatti M; Cudazzo P.; Grobosch M.; Mahns B.; Buchner B.; Rubio A.; Knupfer M.

    2010-01-01

    We are grateful to the Deutsche Forschungsgemeinschaft for financial support (KN393/5 and KN393/9). This work was also supported by the Spanish MEC (FIS2007-65702-C02-01), ACIPromociona (ACI2009-1036), ‘Grupos Consolidados UPV/EHU del Gobierno Vasco’ (IT-319- 07), ETORTEK and by the European Union through e-I3 ETSF (contract 211956) and THEMA (contract 228539) projects. We acknowledge support from the Barcelona Supercomputing Center (‘Red Espanola de Supercomputacion’).

  20. Procedimientos de selección de personal en pequeñas y medianas empresas españolas

    OpenAIRE

    Pamela Alonso; Silvia Moscoso; Dámaris Cuadrado

    2015-01-01

    Este estudio analiza el grado de uso de los diferentes instrumentos de selección en las pequenas y media- ˜ nas empresas (PYME) espanolas. Los resultados encontrados muestran que el CV, las referencias y la ˜ entrevista sin estructura son empleados por la mayoría de las empresas tanto medianas como pequenas. ˜ Estos instrumentos no son los mejores en términos de sus propiedades psicométricas. Los resultados también indican que otros instrumentos con buenas o excelentes propiedades psicométric...

  1. Recopilación de tweets y medición de la relevancia basada en la topología

    OpenAIRE

    DUATO CATALÁN, DANIEL

    2015-01-01

    [ES] En este proyecto se ha creado una base de datos MongoDB y una aplicacion en Python ´ que utiliza la API de Twitter para obtener tuits e informacion de las cuentas de usuarios. Se ´ ha obtenido una coleccion de tuits relacionados con pol ´ ´ıtica espanola. Se han implementado ˜ los algoritmos PageRank y HITS usando matrices obtenidas a partir tanto de las relaciones de seguimiento entre cuentas como de las relaciones de retuits y se han empleado para ordenar a los autores d...

  2. Preconcentration of low-grade uranium ores with environmentally acceptable tailings, part I

    International Nuclear Information System (INIS)

    The low-grade ore sample used for this investigation originated from Agnew Lake Mines Limited, Espanola, Ontario. It contained about 1% pyrite and 0.057% uranium, mainly as uranothorite with a small amount of brannerite. Both of these minerals occur in the quartz-sericite matrix of a conglomerate. A preconcentration process has been developed to give a high uranium recovery, reject pyrite, radium and thorium from the ore and produce environmentally acceptable tailings. This process applies flotation in combination with high intensity magnetic separation and gravity concentration

  3. Elasticidad de la demanda francesa de carne de cordero de origen espanol

    OpenAIRE

    Ameur, Mehrez; Kaabia, Monia Ben; Jose M. Gil

    2004-01-01

    En este trabajo se aborda el estudio de las exporaciones espanolas de carne de ovino y caprino hacia la UE y, en particular, hacia Francia, principal destino de las mismas. El metodo utilizado se basa en la estimacion de un sistema de demanda de importaciones en el que se ha prestado especial atencion a las propiedades estadisticas de las series incluidas. La existencia de precios no estacionarios ha determinado la realizacion de un analisis previo de los mismos con el fin de determinar si es...

  4. La Guadalupe Mexicana a la deriva por el mar de China

    OpenAIRE

    Arcos, María Fernanda G. De Los

    2013-01-01

    A mediados del siglo xviii el gobierno español de Filipinas hizo el encargo de la construcción de una nave en el reino de Siam. Se trataba de un galeón destinado a la llamada carrera de Acapulco, lo cual no significaba solamente el comercio transpacífico sino todo el conjunto de la relación directa entre la América espanola y el Asia oriental. El joven barco recibió el nombre de La Guadalupe Mexicana. Cuando zarpó de su lugar de nacimiento para ir a Marsella y desde allí emprender la ruta a N...

  5. A study on the piston ring wear in automotive engine Seat 1500 CA by means of radioactive tracer technique; Estudio del desgaste de segmentos en motor Seat 1500 CA mediante trazadores radiactivos

    Energy Technology Data Exchange (ETDEWEB)

    Val Cob, M. del; Chul, Y.; Fuentes Figuera de Vargas, J.

    1971-07-01

    The iron side wear in the chromium-plated top compression ring has been a matter of interest for the engine makers and it has been required by them to investigate the wear characteristics of the chromium-plated piston ring. Meanwhile, Bureau of Nuclear Energy in Spain (Junta de Energia Nuclear) and Seat Car Manufacturing Company (Sociedad Espanola de Automoviles de Turismo) agreed to study the wear characteristics of chromium-plated piston ring of type CA gasoline engine for Seat 1500 car by means of radioactive tracer technique. (Author) 9 refs.

  6. ESTUDIO POR DRX DE LA INTERCALACIÓN-PILARIZACIÓN DE UN MINERAL DE ARCILLA TIPO 2:1 CON ESPECIES POLIOXOCATIÓNICAS DE ALUMINIO

    OpenAIRE

    J. G. Carriazo; M-J. Saavedra; M-F. Molina

    2009-01-01

    El presente trabajo muestra la intercalación-pilarización exitosa de un mineral tipo esmectita (bentonita) con especies polioxocatiónicas de aluminio empleando soluciones precursoras de nitrato básico, la obtención en estado sólido del agente pilarizante y su caracterización por difracción de rayos X (DRX). La intercalación-pilarización del mineral procede mediante la inserción inicial de policationes con tamaño aproximado de 9.6 Å y la posible formación de fase ¿-AlOOH luego de la calcinació...

  7. Efecto del ultrasonido en la síntesis de arcilla pilarizada con aluminio en medio concentrado

    OpenAIRE

    Sonia Moreno; Nancy Sanabria; Rafael Molina

    2009-01-01

    En este trabajo se realizó la síntesis de bentonita pilarizada con aluminio en medio concentrado, empleando ultrasonido en la etapa de intercalación. El agente pilarizante fue preparado por hidrólisis del AlCl3 con NaOH, seguido de precipitación con disolución de Na2SO4 y redisolución en Ba(NO3)2, y fue caracterizado por fluorescencia de rayos X (FRX), difracción de rayos X (DRX), microscopía electrónica de barrido (SEM) y resonancia magnética nuclear de aluminio (27Al-RMN). La arcilla pilari...

  8. Enzimas de função hepática na aflatoxicose aguda experimental em frangos de corte Hepatic enzimes function in experimental acute enzimes aflatoxicosis in broilers

    Directory of Open Access Journals (Sweden)

    Adriana Borsa

    1998-12-01

    Full Text Available Com o objetivo de avaliar a função hepática de aves experimentalmente intoxicadas por aflatoxina, com e sem uso de bentonita sódica, foram utilizados 40 (quarenta frangos de corte, machos, linhagem Ross, divididos em 4 (quatro grupos de 10 (dez. animais, sendo que cada grupo foi submetido a um tratamento: T1 - controle (ração sem aflatoxina ou bentonita, T2 - ração com 5ppm de aflatoxina, T3 - ração com 5ppm de aflatoxina e 0,5% de bentonita sódica e T4 - ração com 0,5% de bentonita sódica. Todos estes tratamentos foram aplicados do 1° ao 42 ° dia de vida das aves. Aos 21, 35 e 42 dias de idade, foram analisados os níveis séricos das enzimas aspartato aminotransferase (AST, alanina aminotransferase (ALT, lactato desidrogenase (LDH e gama glutamiltransferase (GGT, A análise da variância mostrou que houve interação entre os tratamentos e datas de colheita de material, para as seguintes variáveis: AST, LDH e GGT. Para estas, foi aplicado o teste de Tukey, comparando-se as médias de cada tratamento em cada data. Observou-se que as enzimas AST, ALT e GGT não apresentaram diferenças significativas entre tratamentos, porém, nos tratamentos l e 2, a AST apresentou um aumento linear (pThe aim ofthis study is to evaluate ïhe hepatic function of experimentally intoxicated broilers by aflatoxin with and without sodium bentonite. Forty Ross mole broilers, were used divided into 4 groups of 10 birds, and such groups have been submitted to the following treatments: T1- control (feed without aflatoxin or sodium bentonite, T2- feed containing 5ppm of aflatoxin, T3- feed containing 5ppm of aflatoxin and 0.5% of sodium bentonite and T4- feed containing 0.5% of sodium bentonite. Ali these treatments have been appiied from the l st to the 42nd day of lif e. On the days 21, 35 and 42, the serum leveis of the enzimes aspartate aminotransferase (AST, alanino aminotransferase (ALT, lactate dehydrogenase (LDH and gamma glutamiltransferase (GGT

  9. Adsorção de Ni2+ e Zn2+ em argila calcinada: estudo de equilíbrio em coluna de leito fixo

    OpenAIRE

    A. L. P. de Araujo; I. L. Nogueira; M. G. C. da Silva; M. L. Gimenes; Barros, M. A. S. D.

    2013-01-01

    A aplicação de argilas para adsorção de metais pesados presentes em efluentes tem sido objeto de estudo em muitas pesquisas em virtude das inúmeras vantagens técnicas e econômicas. Este trabalho teve como objetivo obtenção de isotermas de adsorção de níquel e zinco em coluna de leito fixo utilizando como adsorvente argila bentonita calcinada a 500 ºC. Os experimentos para remoção de níquel e zinco foram conduzidos à temperatura ambiente (20 ºC - 25 ºC), pH da alimentação ajustado em 4,5, mass...

  10. Encapsulação: efeitos sobre a germinação e sanidade das sementes de algodão

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    Arantes Hermes Augusto Guimarães

    2000-01-01

    Full Text Available A presença de línter sobre a superfície das sementes de algodão dificulta os processos de beneficiamento e de semeadura. A aplicação de produtos encapsulantes sobre a superfície da semente pode-se constituir em alternativa para a solução desse problema. Assim, o presente trabalho teve como objetivo estudar o efeito da utilização de diferentes produtos encapsulantes na germinação de sementes de algodão. Para tanto, foram utilizados três lotes de sementes de algodão, cv. IAC 20, safra 94/95, sendo avaliados dez tratamentos: deslintamento mecânico, deslintamento químico, deslintamento mecânico e encapsulação com gesso + bentonita, com Sepiret 4015 e com Sepiret 6182, todos com e sem a aplicação de fungicida. Foram avaliadas a germinação e a sanidade das sementes, em quatro épocas (logo após o preparo das sementes, aos três, seis e nove meses de armazenamento. O delineamento experimental foi o inteiramente casualizado com dez tratamentos e quatro repetições, utilizando-se o teste de Tuckey para a comparação de médias. Pode-se concluir que há possibilidade de utilizar a encapsulação para sementes de algodão; os produtos mais adequados são o gesso + bentonita ou o Sepiret 6182; ocorre efeito benéfico da aplicação do fungicida às sementes.

  11. Radiotherapy evolution in Spain (1896-1996)

    International Nuclear Information System (INIS)

    We show radiotherapy evolution in Spain, from the introduction of the Roentgenology till the consolidation of the radiation therapy. We analyze the development of the roentgenology and the contribution of the dermatologist in it. We should emphasize the importance of the V International Congress of Electrology and Medical Radiology wich took place in December of 1910 in Barcelona in the development of the deep radiotherapy in the treatment of gynecological neoplasms. The sanitary struggle campaigns cancer influenced a lot the development of Spanish radiotherapy. the development of the Cancer's Pavilion of the ''Hospital de la Santa Creu i Sant Pau'' was the most important radiotherapic event in the previous period to the Spanish civil war. After the late introduction of cobaltotherapy in Spain, the birth of the ''Asociacion Espanola de Radioterapia y Oncologia (AERO) helped to consolidate the speciality. (Author) 36 refs

  12. A comparative study of dumping limits in the bye-laws and regulations on industrial waste waters; Estudio comparativo de los limites de vertido en las ordenanzas y reglamentos de aguas residuales industriales

    Energy Technology Data Exchange (ETDEWEB)

    Orus Lacort, M. A.; Capafons, C.; Tussell Ossould, E.; Mantecon Pascual, R.

    2003-07-01

    Since Barcelona City Council published its first set of regulations on the dumping of waste in the sewer system, a large number of regulations have been drawn up and revised throughout Spain. Commission 5 of the Asociacion Espanola de Abastecimientos de Agua y Saneamiento (Spanish Association of Water Supplies and Sewerage) collected 43 of these regulations and extracted 63 parameters from them. Surprisingly, it found that rather unconventional parameters, such arsenic and mercury levels, were the ones most often mentioned. On the contrary, organo chlorides and COT were seldom mentioned. Lists and graphs of parameters are presented showing coincidence or dispersion in the concentrations, Peninsular Spain was divided into four regions (North, Centre, Levant and south) with a view to finding common points sin the regulations depending on the area concerned. (Author)

  13. Nuclear energy in Spain

    International Nuclear Information System (INIS)

    The 'Plan Energetico Nacional de 1983' (1983 National Energy Program)(PEN-83) was approved recently by the Spanish Government and presented to the 'Cortes Espanolas' (Spanish Parliament) in May 1984. The PEN-83 is being discussed at present in the Parliament and it is possible that some modifications be introduced, but expectedly will be rather limited and minor. PEN-83 covers the period 1983-1992. It includes a comparative analysis of the evolution and situation in OECD countries and in Spain. In Spain the offer, supply and consumption of primary energy and of the interrelation with other economic indicators, such as the gross domestic product, inflation rate and unemployment compared with that of the industrialized OECD countries, has shown a much lower capability to adapt its structure to the energy price increases

  14. Procedimientos de selección de personal en pequeñas y medianas empresas españolas

    Directory of Open Access Journals (Sweden)

    Pamela Alonso

    2015-01-01

    Full Text Available Este estudio analiza el grado de uso de los diferentes instrumentos de selección en las pequenas y media- ˜ nas empresas (PYME espanolas. Los resultados encontrados muestran que el CV, las referencias y la ˜ entrevista sin estructura son empleados por la mayoría de las empresas tanto medianas como pequenas. ˜ Estos instrumentos no son los mejores en términos de sus propiedades psicométricas. Los resultados también indican que otros instrumentos con buenas o excelentes propiedades psicométricas, como los tests de habilidades cognitivas, las medidas de personalidad, las entrevistas estructuradas y las pruebas profesionales, son empleados por un porcentaje cada vez mayor de empresas. Por último, se comentan las implicaciones que estos resultados tienen para la práctica profesional y se ofrecen sugerencias para futuras investigaciones.

  15. 110 years of Avipoxvirus in the Galapagos Islands.

    Directory of Open Access Journals (Sweden)

    Patricia G Parker

    Full Text Available The role of disease in regulating populations is controversial, partly owing to the absence of good disease records in historic wildlife populations. We examined birds collected in the Galapagos Islands between 1891 and 1906 that are currently held at the California Academy of Sciences and the Zoologisches Staatssammlung Muenchen, including 3973 specimens representing species from two well-studied families of endemic passerine birds: finches and mockingbirds. Beginning with samples collected in 1899, we observed cutaneous lesions consistent with Avipoxvirus on 226 (6.3% specimens. Histopathology and viral genotyping of 59 candidate tissue samples from six islands showed that 21 (35.6% were positive for Avipoxvirus, while alternative diagnoses for some of those testing negative by both methods were feather follicle cysts, non-specific dermatitis, or post mortem fungal colonization. Positive specimens were significantly nonrandomly distributed among islands both for mockingbirds (San Cristobal vs. Espanola, Santa Fe and Santa Cruz and for finches (San Cristobal and Isabela vs. Santa Cruz and Floreana, and overall highly significantly distributed toward islands that were inhabited by humans (San Cristobal, Isabela, Floreana vs. uninhabited at the time of collection (Santa Cruz, Santa Fe, Espanola, with only one positive individual on an uninhabited island. Eleven of the positive specimens sequenced successfully were identical at four diagnostic sites to the two canarypox variants previously described in contemporary Galapagos passerines. We conclude that this virus was introduced late in 1890's and was dispersed among islands by a variety of mechanisms, including regular human movements among colonized islands. At present, this disease represents an ongoing threat to the birds on the Galapagos Islands.

  16. Estudio cinético del proceso de digestión anaerobia de las aguas residuales de la elaboración de aceitunas de mesa negras

    Directory of Open Access Journals (Sweden)

    Borja Padilla, R.

    1992-12-01

    Full Text Available A kinetic study of the anaerobic digestion process of wastewaters from black olive preparation was carried out. The bioreactors used accommodated various suspended micronized clay supports of different chemical composition (Sepiolite and Bentonite. Assuming that the overall anaerobic digestion process conforms to a first-order kinetics, experimental data pairs, namely the methane volume yielded (G and the time (t fitted the equation: G=Gm·[1-exp (-Ko·t], the rate coefficient, Ko, was determined in each of the situations studied. The support used has a marked influence on the kinetic constant of the process; the Sepiolite support yields significantly the highest values. The average Ko values, obtained in the rank of COD between 0 and 1 g/L were: 1,83 days-1 (Sepiolite and 1,23 days-1 (Bentonite. For values of COD greater than 1g/L, the specific rate constant decreased when the volume of wastewater added or substrate concentration was increased. The yield coefficients of methane, Yp/s, were 333 and 316 mL CH4/g COD for the Sepiolite and Bentonite reactor, respectively. Treatment yields of COD were above 95% in all the cases.

    Se ha efectuado un estudio cinético del proceso de digestión anaerobia de las aguas residuales obtenidas en la elaboración de aceitunas negras, mediante biorreactores que contienen en suspensión soportes micronizados de tipo arcilloso de distinta composición química (Sepiolita y Bentonita. Admitiendo que globalmente el proceso de digestión anaerobia sigue una cinética de primer orden, se ajustan las parejas de datos experimentales, volumen de metano acumulado (G, tiempo (t a la ecuación: G=Gm·[1-exp (-Ko·t], determinándose los valores del coeficiente de velocidad Ko, para cada caso estudiado. El soporte utilizado ejerce una influencia acusada sobre la constante cinética del proceso

  17. Avaliação da integridade e da retenção de metais pesados em materiais estabilizados por solidificação Assessment of integrity and retention of heavy metals in materials stabilized by solidification

    Directory of Open Access Journals (Sweden)

    André Luiz Fiquene de Brito

    2009-03-01

    Full Text Available A quantidade de resíduos sólidos industriais tem aumentado significativamente em decorrência da industrialização, e o seu gerenciamento adequado é necessário para reduzir o impacto ao meio ambiente e aos ecossistemas. Neste trabalho, foram avaliadas a integridade e a retenção de metais pesados em materiais estabilizados por solidificação. Foi adotado o planejamento completamente aleatorizado com um único fator, ou seja, foram comparadas as médias de quatro tratamentos (A, B, C e D com 0, 40, 50 e 60% respectivamente de contaminantes e três repetições. Cimento Portland comum, bentonita sódica e hidróxido de cálcio foram usados para estabilizar por solidificação o resíduo sólido sintético contendo óxido de Cd2+, Pb2+ e Cu2+. Pode-se concluir que os tratamentos influenciaram no resultado de lixiviação do cádmio, chumbo e cobre. Os tratamentos mostraram que as concentrações do extrato solubilizado e lixiviado aumentam em função da quantidade de cádmio, chumbo e cobre adicionada. O maior valor encontrado foi para o material proveniente do tratamento D, que apresentou lixiviação igual a 32,815 mg.kg-1 para o cádmio e 29,769 mg.kg-1 para o chumbo. Para os ensaios de integridade/durabilidade, constatou-se que o aumento da absorção de água fez com que a resistência à compressão diminuísse. O uso de cimento, de hidróxido de cálcio e de bentonita sódica se mostrou ideal para retenção de metais pesados, evitando a sua lixiviação e a solubilização para o meio ambiente.As the quantity of hazardous industrial wastes increases significantly owing to rapid industrialization, its appropriate management is required to reduce adverse impacts on humans and ecosystems. This work evaluated the integrity and retention of heavy metals in materials stabilized by solidification. It was adopted a completely randomized design with a single factor, that is, the averages of four treatments were compared (A, B, C and D with 0

  18. Análise da influência do tratamento de purificação no comportamento de inchamento de argilas organofílicas em meios não aquosos Analysis of the influence of the purification treatment on the swelling behavior in non-aqueous media of organophilic clays

    Directory of Open Access Journals (Sweden)

    H. S. Ferreira

    2008-03-01

    Full Text Available As argilas bentonitas possuem importantes funções em fluidos de perfuração não aquosos. No entanto, impurezas presentes na argila e a escolha inadequada do sal quaternário utilizado no seu processo de organofilização podem comprometer a compatibilidade do sistema argila-fluido. Assim, este trabalho tem por objetivo analisar a influência do tratamento de purificação e dos sais quaternários de amônio no comportamento de inchamento de argilas organofílicas em meios não aquosos. A argila bentonita foi purificada através de procedimento de sedimentação e as argilas organofílicas foram preparadas utilizando-se cloreto de alquil benzil amônio (Dodigen, cloreto de diestearil dimetil amônio (Praepagen, cloreto de cetil trimetil amônio (Genamim e brometo de cetil trimetil amônio (Cetremide. As argilas organofilizadas foram caracterizadas por difração de raios X e determinação da distribuição do tamanho de partículas e, em seguida, submetidas ao ensaio de inchamento de Foster em éster, parafina e óleo diesel. Os resultados mostram que o processo de purificação foi eficiente na redução de impurezas presentes na bentonita e que a argila organofílica purificada tratada com Praepagen e Genamim apresenta valores de inchamento de Foster em éster, óleo diesel e parafina superiores aos obtidos com argilas organofílicas sem purificação (natural e comercial.Bentonite clays play important roles in oil based drilling fluids. However, clay impurities and the wrong choose of the quaternary ammonium salt used in the organophilization process can lead to organoclay-fluid low interactions. Thus, this work has as aim study the influence of the purification process and quaternary ammonium salts on the swelling behavior in oil media of organophilic clays. The bentonite clay was purified using a sedimentation process and organoclay were prepared using alkyl dimethyl benzyl ammonium chloride (Dodigen, distearyl dimethyl ammonium

  19. Estudio cinegético de la digestión anaerobia de alpechín, procedente de la extracción de aceite utilizando olivex, previamente biotratado con Geotrichum Candidum

    Directory of Open Access Journals (Sweden)

    González Becerra, A.

    1992-08-01

    Full Text Available A kinetic study of the anaerobic digestion of olive mill wastewater (OMW which was obtained with the technological helper "Olivex", was carried out. An identical wastewater, obtained without this enzyme was also used. Both OMW were pre-treated aerobically with Geotrichum Candidum to eliminate the greater part of the phenolic compounds responsible for inhibition. The anaerobic process was carried out in bioreactors with microorganisms immobilized on two micronized clay supports, Sepiolite and Bentonite. Assuming that the overall anaerobic digestion process conforms to a first-order kinetic, specific rate constants, Ko, were obtained by using the Roediger's equation in each case. In contrast to what takes place with both OMW without pretreatment, kinetic constant was observed virtually constant when the substrate concentration was increased, in the range of COD (chemical oxygen demand studied. The mean value of this kinetic parameter was a 40% larger for the OMW obtained with Olivex compared to the reference OMW, in the two digesters used. Sepiolite favoured the kinetic and increased the yield coefficient compared to Bentonite.Se ha efectuado un estudio cinético del proceso de digestión anaerobia de un alpechín obtenido con el coadyuvante tecnológico "Olivex" en comparación con un testigo obtenido sin este enzima, que previamente han sido tratados de forma aerobia con Geotrichum Candidum para eliminar la mayor parte de los compuestos fenólicos responsables de su poder inhibidor. El proceso anaerobio se ha realizado en biorreactores con microorganismos inmovilizados en dos soportes micronizados arcillosos, Sepiolita y Bentonita. Admitiendo que globalmente el proceso de digestión anaerobia sigue una cinética de primer orden, se obtienen las constantes específicas de velocidad, Ko, para cada caso estudiado usando la ecuación de Roediger. A diferencia de lo que ocurre con ambos alpechines sin pretratar, la constante cinética se mantiene pr

  20. Uso de argila organofílica na compatibilização de misturas PP/EPDM The use of an organoclay on the compatibilization of PP/EPDM Blends

    Directory of Open Access Journals (Sweden)

    Kaline R. M. Ferreira

    2011-01-01

    Full Text Available Misturas PP/EPDM com variadas razões PP:EPDM, não compatibilizadas e compatibilizadas com o polipropileno modificado com anidrido maleico (PP-g-MA, foram preparadas por fusão. A influência da adição de 1 pcr de uma argila bentonita na morfologia, propriedades mecânicas e reológicas destas misturas foi avaliada. A bentonita empregada como carga, proveniente da Bentonit União Nordeste/PB foi purificada e modificada organicamente com tecnologia desenvolvida por nosso grupo de pesquisa, antes de ser adicionada às misturas. Os dados de difratometria de raios X mostraram que, para diferentes razões de PP:EPDM na mistura a incorporação de 1 pcr de argila organofílica resultou na formação de nanocompósitos intercalados desordenados (20 ou 40% de EPDM ou intercalados/esfoliados (10 e 30% EPDM. A incorporação da argila organofílica provocou alterações nas propriedades morfológicas, mecânicas e reológicas das misturas, especialmente daquelas preparadas com 30% em massa de EPDM onde a ação compatibilizante da argila foi observada.PP/EPDM blends with different PP:EPDM ratios, non-compatibilized and compatibilized with maleic anhydride grafted polypropylene (PP-g-MA were prepared by melting. The influence of 1 phr bentonite clay addition on the morphology, mechanical and rheological properties of these blends was evaluated. The bentonite used as a filler, provided by Bentonit União Nordeste/PB, was purified and organically modified with a technology developed by our research group, before being added to the blends. X-ray diffraction results showed that, for blends having different PP:EPDM ratios, 1 phr organoclay addition led to the formation of intercalated (20 or 40% EPDM or intercalated/exfoliated (10 and 30% EPDM nanocomposites. The morphological, mechanical and rheological properties of the blends were modified by organoclay addition, especially for those with 30 wt% of EPDM, where a compatibilizing effect of the organoclay

  1. Comparação da eficiência de três materiais na sorção e difusão dos íons metálicos através de ensaios experimentais e simulação computacional A comparison of the efficiency of three materials on metal ions sorption and diffusion using experimental tests and computational simulation

    Directory of Open Access Journals (Sweden)

    Cláudia Virgínia Lacerda

    2011-12-01

    Full Text Available Com objetivo de obter parâmetros fundamentais do transporte e retenção de íons metálicos em sistemas de contenção, utilizou-se lixiviado sintético, com pH 1 e conhecidas concentrações dos íons cromo, cádmio e cobre. Através de ensaios de sorção e difusão molecular, estudou-se o comportamento dos íons metálicos em solo compactado, solo com 10% de bentonita sódica compactado e solo compactado sobreposto por geomembrana. Foi implementado, no programa MPHMTP (Multi Phase Heat and Mass Transfer Program, as equações que descrevem o comportamento dos íons investigados com parâmetros de ajustes obtidos através dos ensaios de sorção e difusão. A presença da geomembrana minimiza a migração dos metais pelo processo difusivo, sendo que a capacidade de sorção do solo não é exigida em função da presença da geomembrana. Porém a opção solo com bentonita mostrou-se uma alternativa específica predominantemente pela capacidade de sorção do cádmio.The present study aims to quantify basic parameters for the transport and retention of metal ions in contention barrier systems. A synthetic leachate with pH 1 and known concentrations of ions chromium, cadmium and copper was used. Sorption and molecular diffusion experiments were carried out in compacted soil, soil mixture with 10% sodium bentonite and compacted soil overlaid with geomembrane. It was implemented in the program MPHMTP (Multi Phase Heat and Mass Transfer Program where the equations describe ion behavior under adjusted parameters obtained from sorption and diffusion tests. The geomembrane’s presence minimizes ion migration through a diffusive process, and eliminates the need for the soil sorption capacity. But the soil with the bentonite option proved to be the most predominant specific alternative due to its cadmium sorption capacity.

  2. Physicochemical and biological characterization of the Roble river, Upper Cauca, western Colombia Caracterización fisicoquímica y biológica del río Roble, Alto Cauca, occidente de Colombia

    Directory of Open Access Journals (Sweden)

    Carlos A. García-Alzate

    2010-06-01

    Full Text Available To determine dial and seasonal differences as well as productivity and the trophic status of the lower Roble river, a tributary of the Vieja and upper Cauca rivers of west Colombia, we sampled phytoplankton, zooplankton, fish and macroinvertebrates and recorded physicochemical variables (dissolved oxygen, percent oxygen saturation, pH, conductivity, relative humidity, environmental, water, maximum and minimum temperatures, width, depth, current velocity, substrate, CO2, COD, BOD, total calcium and magnesium hardness, total, dissolved and suspended solids, alkalinity, acidity, chlorine and turbidity during the wet and dry seasons. Most physicochemical variables such as relative humidity, dissolved oxygen and percent oxygen saturation showed low coefficients of variation, except for oxygen deficit. The Shannon-Wiener diversity index, equity and dominance had low values around 0.5. We recorded eight orders, 28 families and 58 genera of macroinvertebrates, three divisions, five orders and 45 genera of phytoplankton, two divisions and six genera of zooplankton and 19 species of fishes. This river has an allochthonous-heterotrophic trophic state and productivity is oligotrophic but with a tendency to eutrophication.Para determinar las diferencias diarias y estaciónales, así como la productividad y el estado trófico del río Roble, un afluente de la Vieja, alto Cauca al occidente de Colombia, tomamos muestras de fitoplancton, zooplancton, peces y macroinvertebrados y registramos variables físico-químicas (oxígeno disuelto, porcentaje de saturación de oxígeno, pH, conductividad, humedad relativa, temperaturas ambiente, del agua, máximas y mínimas, ancho, profundidad, velocidad de la corriente, sustrato, CO2, DQO, DBO5, dureza total, dureza calcica y durezas magnesicas, sólidos totales, disueltos y suspendidos, alcalinidad , acidez, cloruros y turbidez durante sequía y lluvias. La mayoría de las variables físico-químicas tales como la

  3. The Person Centered approach in Gerontology: New validity evidence of the Staff Assessment Person-directed Care Questionnaire

    Directory of Open Access Journals (Sweden)

    Teresa Martínez

    2016-01-01

    Full Text Available Antecedentes/Objetivos La atención centrada en la persona es un enfoque innovador que busca mejorar la calidad asistencial de los servicios para personas mayores que precisan cuidados. Ante el creciente interés hacia este enfoque es necesario contar con instrumentos de medida que permitan evaluar en qué grado los servicios gerontológicos llevan a cabo una atención centrada en la persona. El objetivo de este trabajo es la adaptación y validación del Staff Assessment Person-directed Care (PDC en población espanola. ˜ Método Se llevó a cabo la traducción y adaptación del PDC al espanol ˜ y se aplicó a una muestra de 1.339 profesionales de atención directa, pertenecientes a 56 residencias para personas mayores. El estudio de las propiedades psicométricas se realizó desde el marco de la Teoría Clásica de los Tests y los modelos de Teoría de Respuesta a los Ítems. Resultados El coeficiente alfa de Cronbach fue de 0,97 y el coeficiente de fiabilidad test-retest de 0,89. La Función de Información indica que la prueba mide de forma precisa para un amplio rango de puntuaciones (valores entre -2 y + 2. La estructura factorial del PDC es esencialmente unidimensional, confirmándose la existencia de dos grandes dimensiones que se articulan a su vez en ocho factores muy correlacionados. En cuanto a la validez predictiva destacan las correlaciones del PDC con el The Person-centered Care Assessment Tool (r= 0,68, con el clima organizacional (r = 0,67 y con los factores del burnout, agotamiento emocional (r= -0,41 y realización personal (r = 0,46. Conclusiones La versión espanola ˜ del PDC confirma los resultados encontrados en otras poblaciones, presentando unas excelentes propiedades psicométricas para su uso en la evaluación de residencias de personas mayores, tanto con fines profesionales como de investigación.

  4. Paleomagnetism and Tectonic Interpretations of the Taos Plateau Volcanic Field, Rio Grande Rift, New Mexico

    Science.gov (United States)

    Brown, Laurie L.; Caffall, Nancy M.; Golombek, Matthew P.

    1993-01-01

    The tectonic response of the Taos Plateau volcanic field in the southern San Luis basin to the late stage extensional environment of the Rio Grande rift was investigated using paleomagnetic techniques. Sixty-two sites (533 samples) of Pliocene volcanic units were collected covering four major rock types with ages of 4.7 to 1.8 Ma. Twenty-two of these sites were from stratigraphic sections of the lower, middle and upper Servilleta Basalt collected in the Rio Grande gorge at two locations 19 km apart. Flows from the lower and middle members in the southern gorge record reversed polarities, while those in Garapata Canyon are normal with an excursion event in the middle of the sequence. The uppermost flows of the upper member at both sites display normal directions. Although these sections correlate chemically, they seem to represent different magnetic time periods during the Gilbert Reversed-Polarity Chiron. Alternating field demagnetization, aided by principal component analysis, yields 55 sites with stable directions representing both normal and reversed polarities, and five sites indicating transitional fields. Mean direction of the normal and inverted reversed sites is I=49.3 deg. and D=356.7 deg. (alpha(sub 95)=3.6 deg). Angular dispersion of the virtual geomagnetic poles is 16.3 deg, which is consistent with paleosecular variation model G, fit to data from the past 5 m.y. Comparison with the expected direction indicates no azimuthal rotation of the Taos Plateau volcanic field; inclination flattening for the southern part of the plateau is 8.3 deg +/- 5.3 deg. Previous paleomagnelic data indicate 10 deg- 15 deg counterclockwise rotation of die Espanola block to the south over the past 5 m.y. The data suggest the Taos Plateau volcanic field, showing no rotation and some flattening in the south and east, has acted as a stable buttress and has been downwarped by overriding of the southeastern end of the plateau by the Picuris Mountains, which make up the northern

  5. EFECTO DEL ULTRASONIDO EN LA SÍNTESIS DE ARCILLA PILARIZADA CON ALUMINIO EN MEDIO CONCENTRADO

    Directory of Open Access Journals (Sweden)

    Sonia Moreno

    2009-04-01

    Full Text Available En este trabajo se realizó la síntesis de bentonita pilarizada con aluminio en medio concentrado, empleando ultrasonido en la etapa de intercalación. El agente pilarizante fue preparado por hidrólisis del AlCl3 con NaOH, seguido de precipitación con disolución de Na2SO4 y redisolución en Ba(NO32, y fue caracterizado por fluorescencia de rayos X (FRX, difracción de rayos X (DRX, microscopía electrónica de barrido (SEM y resonancia magnética nuclear de aluminio (27Al-RMN. La arcilla pilarizada fue caracterizada por FRX, DRX y fisiadsorción de N2 a 77 K, revelando propiedades estructurales y texturales comparables a la modificada siguiendo la metodología convencional: suspensiones diluidas y tiempos de intercalación elevados. El empleo de suspensiones concentradas de arcilla-agente pilarizante y la aplicación de ultrasonido en la etapa de intercalación, permiten una disminución en el volumen de agua entre el 90-95 % y una reducción en el tiempo de intercalación entre el 70–93 % respecto al método convencional de pilarización.

  6. Influência da hidrociclonagem e da secagem por spray dryer nas propriedades reológicas de argilas bentoníticas

    Directory of Open Access Journals (Sweden)

    V. C. Marques

    2015-09-01

    Full Text Available ResumoA exploração desordenada ao longo dos anos das argilas bentoníticas do município de Boa Vista, PB, resultou no esgotamento das variedades nobres. Assim, o que existe atualmente são bentonitas com elevado percentual de minerais acessórios, elementos contaminantes a exemplo do quartzo, os quais influem negativamente nas propriedades reológicas das dispersões. O presente trabalho propõe concentrar dispersões dessas argilas pouco nobres pela operação de hidrociclonagem e posterior secagem por spray dryer, visando à obtenção de amostras com valores de reologia de acordo com norma EP-1EP-00011-A da Petrobrás. Assim, preparou-se dispersões de três composições com as argilas Bofe, Chocolate, Verde-Lodo, Chocobofe e Sortida previamente selecionadas por planejamento experimental com concentrações de 4% em massa de argila para serem concentradas por hidrociclonagem. Os concentrados foram secos por spray dryer em duas condições de secagem. Os resultados evidenciaram a eficiência das operações de hidrociclonagem e secagem por spray dryer das misturas com notável melhoria nas propriedades reológicas.

  7. Preparação e caracterização de nanocompósitos poliméricos baseados em quitosana e argilo minerais

    Directory of Open Access Journals (Sweden)

    Ana Paula Santos de Melo Fiori

    2014-10-01

    Full Text Available Neste trabalho foram preparados nanocompósitos baseados em quitosana e diferentes tipos de argilas usando polietileno glicol (PEG como plastificante. As amostras foram caracterizadas por espectroscopia de infravermelho (FTIR, difração de raios X (DRX, análise termogravimétrica (TGA/DTG, e por análise mecânica (ensaio de tração com o objetivo de avaliar as interações entre a quitosana e a argila. Os filmes de nanocompósitos preparados usando Bentonita sódica (Ben apresentaram um aumento de 81,2% no valor da tensão máxima de ruptura e uma redução de 16,0% no módulo de elasticidade (Young em relação aos filmes de quitosana com PEG (QuiPEG, evidenciando que a introdução da argila na matriz polimérica resultou em um filme mais flexível e resistente, cujo alongamento na ruptura foi 93,6% maior que o apresentado pelo filme de QuiPEG.

  8. Influência da adição e da modificação química de uma carga mineral nanoparticulada nas propriedades mecânicas e no envelhecimento térmico de compósitos poliuretano/sisal Influence of a nanoparticulate mineral filler addition and chemical modification of the mechanical properties and thermal aging of PU/Sisal composites

    Directory of Open Access Journals (Sweden)

    Maria Roberta O. Pinto

    2005-11-01

    Full Text Available Este trabalho trata do efeito da hibridização do reforço, através da adição de uma carga mineral (bentonita nanoparticulada, no desempenho mecânico de compósitos poliuretano/sisal contendo 25% em massa de fibras de sisal e moldados por compressão. As propriedades mecânicas, de tração e impacto, dos sistemas compósitos estudados foram avaliadas em função do teor (0-10% em massa e de modificações químicas da carga mineral. Os efeitos do envelhecimento térmico nas propriedades tênseis (sigma, E, épsilon de compósitos selecionados também foram investigados. O reforço mineral (Bentonita sódica Brasgel-PA foi empregado em quatro formas, a saber: a como fornecido (sem tratamento, b tratado com ácido clorídrico (0,6N, c modificado com cloreto de dodecil dimetil benzil amônio (Dodigen e d modificado com brometo de cetil trimetil amônio (Cetremide. Os resultados indicam que a incorporação da bentonita eleva as propriedades mecânicas dos compósitos e que melhores propriedades foram obtidas quando a bentonita foi tratada com o ácido clorídrico. O envelhecimento térmico em tempos curtos (até 4 dias provocou elevação no módulo elástico e resistência na ruptura dos compósitos, o que foi atribuído à pós-cura da matriz. Em tempos longos (32 dias a exposição térmica causou decréscimo nas propriedades tênseis (sigma, E, épsilon dos compósitos investigados, o que foi atribuído à degradação oxidativa da matriz e dos reforços. O compósito mais resistente ao envelhecimento térmico foi o híbrido cuja carga mineral foi organofilizada com o sal Cetremide. Anáslies por DRX e MEV indicam que a estrutura dos compósitos híbridos é um misto de micro e nanocompósito.This work deals with filler hybridization effects, by the addition of a nanoparticulate mineral filler (bentonite, on the mechanical performance of compression molded Polyurethane/sisal composites with 25 wt % fiber content. Composite tensile and

  9. DESARROLLO DE UNA PASTA DE REVELADO BASADA EN EL REACTIVO DE FRY

    Directory of Open Access Journals (Sweden)

    Roberto Puentes

    2012-01-01

    Full Text Available En el presente trabajo se realiza el diseño de un agente de revelado o revenido químico basado en una pasta conteniendo el reactivo de Fry (una solución de CuCl2 en HCl y bentonita. Esta pasta de revelado, puede aplicarse a diversas muestras de hierro y aceros similares a las encontradas en muchos motores de vehículos. La eficiencia del revelado es similar a la que presenta el uso del reactivo líquido. Además, esta pasta de revelado presenta ventajas para su aplicación, pues evita los problemas de derrame de soluciones ácidas durante su aplicación por técnicos y peritos policiales. Los ensayos por microscopía electrónica muestran asimismo que no se produce una alteración morfológica de la superficie metálica durante el proceso. Actualmente la pasta desarrollada está siendo eficientemente utilizada por personal policial en Uruguay.

  10. Content validity evidences in test development: An applied perspective

    Directory of Open Access Journals (Sweden)

    Elena Delgado-Rico

    2012-01-01

    Full Text Available El objetivo de este estudio instrumental es mostrar los pasos a seguir para la obtenci6n de evidencias de validez de contenido dentro del proccso de construcción/adaptacion de tests. Para ello se haec usa de una perspectiva aplicada, presentandose el estudio de validez de contenido llevada a cabo para la adaptacion espm:lo1a de la version rasgo del S'fafe-Trait Cheerfitlness Inventory (STCI-T. Este trabajo profundiza en las fases que permiten obtener evidencias de validez de contenido: 1 definicion de las areas de contenido a evaluar, 2 construcci6n de items y 3 evaluaci6n a traves de expertos de los items constnridos. Para este liltimo plmto se muestran los resultados encontrados para un panel de expertos previamente seleccionado. La presentaci6n se centTa en los criterios para la selecci6n de expertos, procedimiento general a seguir, material para admirristrar, aspectos a evaluar de los items, Ycwculos mas importantes. Se temlina argllmentando sobre la relev8ncia de la validez de contenido en el proceso de constmccion/adaptacion de tests a partir de los resultados obtenidos para la adaptacion espanola del STCI-T. Estos resultados ponen de manifiesto llllOS buenos indices de validez de contenido para los items de la version espm:l01a del STCI-T.

  11. Composición corporal y velocidad de lanzamiento en jugadoras de élite de balonmano

    Directory of Open Access Journals (Sweden)

    Miriam García Expósito

    2011-01-01

    Full Text Available El objetivo de este estudio fue describir y comparar las caracteristicas antropometricas, composicion corporal, somatotipo y velocidad de lanzamiento de las jugadoras de balonmano de la seleccion espanola de diferentes categorias. Fueron estudiadas 59 jugadoras de balonmano, todas ellas pertenecen a las categorias juvenil, junior y senior. Las variables analizadas fueron: 20 medidas antropometricas, el indice de masa corporal, sumatorio de cuatro pliegues, porcentaje muscular, el somatotipo y las velocidades de lanzamiento. No se encontraron diferencias estadisticamente significativas (p . 0,05 en las variables que caracterizan a la muestra asi como en el somatotipo y velocidad de lanzamiento en los distintos equipos nacionales. Todas las selecciones estudiadas presentan un somatotipo endo-mesomorfico a excepcion del equipo juvenil que presenta un somatotipo meso-endomorfico. Los resultados corroboran que existe un prototipo de jugadora de balonmano similar en todas las categorias. El componente mesomorfico es el predominante por lo que se puede deducir que la robustez musculo-esqueletico en el balonmano femenino puede ser determinante.

  12. Factors controlling the stable isotopic composition of recent precipitation in Spain

    International Nuclear Information System (INIS)

    Composite monthly samples of precipitation were collected for the period 2000-2004 at 16 meteorological stations included in the 'Red Espanola de Vigilancia de Isotopos en la Precipitation' (REVIP), the Spanish Network for Isotopes in Precipitation, Oxygen-18 and deuterium results were used to review previous maps showing the spatial distribution of isotope contents over the Iberian Peninsula. Long-term mean weighted values of δ18O over the Iberian Peninsula range from ca. -4.0 per mille in stations from Andalusia to ca. -10.0 per mille in the stations located in the northern plateau. The δ2H-δ18O relationship of the long-term, weighted means is in good agreement with the GMWL, showing excess values only slightly above 10 per mille indicating the relevance of air masses of Atlantic origin, as the main source of water vapour over the Iberian Peninsula. The spatial distribution of δ18O and δ2H in precipitation over the Iberian Peninsula can be explained by a simple multiple regression model, based on two geographic factors: latitude and elevation. This polynomial model reproduces reasonably well the observed spatial distribution of the stable isotope composition of precipitation over Spain, facilitating the use of stable isotopes as a tool to trace the origin of surface and ground waters. Differences between measured and predicted δ18O values with both global and local scale models are explained by other regional and local factors that influence the isotopic composition of precipitation. (author)

  13. Factors controlling the stable isotopic composition of recent precipitation in Spain

    International Nuclear Information System (INIS)

    Composite monthly samples of precipitation were collected for the period 2000- 2004 at 16 meteorological stations included in the 'Red Espanola de Vigilancia de Isotopos en la Precipitacion' (REVIP), the Spanish Network for Isotopes in Precipitation. Oxygen-18 and deuterium results were used to review previous maps showing the spatial distribution of isotope contents over the Iberian Peninsula. Long-term mean weighted values of δ18O over the Iberian Peninsula range from ca. -4.0 per mille in stations from Andalusia to ca. -10.0 per mille in the stations located in the northern plateau. The δ2H-δ18O relationship of the long-term weighted means is in good agreement with the GMWL, showing d-excess values only slightly above 10 per mille, indicating the relevance of air masses of Atlantic origin, as the main source of water vapour over the Iberian Peninsula. The spatial distribution of δ18O and δ2H in precipitation over the Iberian Peninsula can be explained by a simple multiple regression model, based on two geographic factors: latitude and elevation. This polynomial model reproduces reasonably well the observed spatial distribution of the stable isotope composition of precipitation over Spain, facilitating the use of stable isotopes as a tool to trace the origin of surface and ground waters. Differences between measured and predicted δ18O values with both global and local scale models are explained by other regional and local factors that influence the isotopic composition of precipitation. (author)

  14. Preoperational radiation surveillance of the WIPP Project by EEG for the years 1993 - 1995

    International Nuclear Information System (INIS)

    Average 241Am, 239+240Pu and 238Pu concentrations measured in ambient air near the Waste Isolation Pilot Plant (WIPP) site during 1993, 1994 and 1995 are consistent with similar data reported by the U.S. Environmental Protection Agency (EPA) and Los Alamos National Laboratory (LANL) for Espanola, Pojoaque and Santa Fe, New Mexico. Through the use of replicate analyses of matrix blanks minimum detectable activity (MDA), minimum detectable concentration (MDC) and action levels (ACTL) were established for the Environmental Evaluation Group (EEG) measurement system. Using MDA data from fixed air sampler (FAS) filters and conservative assumptions applied in the National Council on Radiation Protection and Measurements (NCRP) Report 123 (NCRP 1996), it is shown that the EEG sampling and measurement methodology is capable of detecting effluent air emissions which would produce a dose that is approximately 1000 times below the 40 CFR 191 Subpart A limit of 2.5E-4 Sv/y (25 mrem/y). A similar calculation using the NCRP worksheet with storm water effluent MDCs found the EEG measurement program capable of detecting actinide emissions which would result in a dose that is approximately 10 times below the dose limits in 40 CFR 191 Subpart A and 40 CFR 61 Subpart H

  15. Transversotrema Witenberg, 1944 (Trematoda: Transversotrematidae) from inshore fishes of Australia: description of a new species and significant range extensions for three congeners.

    Science.gov (United States)

    Cutmore, Scott C; Diggles, Ben K; Cribb, Thomas H

    2016-09-01

    Four transversotrematid trematodes are reported from commercial teleost species in Australian waters. Transversotrema hunterae n. sp. is described from three species of Sillago Cuvier (Sillaginidae) from Moreton Bay, south-east Queensland. Molecular characterisation using ITS2 rDNA confirmed this stenoxenic specificity of Transversotrema hunterae n. sp., with identical sequence data from Sillago maculata Quoy & Gaimard, S. analis Whitley and S. ciliata Cuvier. Phylogenetic analysis, based on 28S rDNA data, demonstrates that T. hunterae n. sp. belongs to the 'Transversotrema licinum clade' and is most closely related to Transversotrema licinum Manter, 1970 and T. polynesiae Cribb, Adlard, Bray, Sasal & Cutmore, 2014, with the three species forming a well-supported clade in all analyses. We extend the known host and geographical ranges of three previously described Transversotrema species, T. licinum, T. elegans Hunter, Ingram, Adlard, Bray & Cribb, 2010 and T. espanola Hunter & Cribb, 2012. The new records represent significant range extensions for the three species and permit further examination of the patterns of biogeographical distribution in Australian waters. Host-specificity of Transversotrema species is examined, and the degree to which morphological analysis can inform taxonomic studies of this group is discussed. PMID:27522364

  16. Dosimetry by means of external dose rate measurements in patients undergoing 131I thyroid cancer theraphy; Dosimetria de pacientes con cancer diferenciado de tiroides en tratamiento de terapia metabolica con 131I a partir de medidas de tasa de dosis externa

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz, M.A.; Ferrer, N.; Cordoba, D.; Alonso, L.; Sastre, J.M.; Arranz, L.

    2010-07-01

    Dosimetry in patients treated with radiopharmaceuticals needs to be carried out for each individual treatment. No standardized procedure is currently available. In our study, the dosimetry for each individual treatment has been calculated using the dose protocol of the Sociedad Espanola de Fisica Medica for the treatment of thyroid cancer with 131I. This protocol is currently under review, since it proposes a procedure which only uses the daily external dose rate measurements during the patient hospital stay and an external dose rate measurement performed 7-9 days after the activity administration. The results obtained seem to be consistent with those found by other authors following different procedures. Moreover, this protocol has proved to be very useful to verify the values of doses established for red marrow are not exceeded. The maximum activity that can be administered in later treatments could also be assessed with this procedure. Additionally, the activity in urine, which cannot be measured directly, was determined. The potential dose which any patients relative or any person staying close to the patient might receive during the treatment was determined as well. These results make it possible to establish more realistic criteria regarding radiation protection. (Author).

  17. Analysis of the soil amplification factor in NCSE-02 and Eurocode-8 regulations: application to the 11th May , 2011 Lorca earthquake

    International Nuclear Information System (INIS)

    Earthquakes are one of the geological hazards which have produced more human and material loses in the history of manking. Seismic engineering has the purpose of studying the soil dynamic behavior in order to desing structures and buildings adapted to the effects triggered by earthquakes. Within this purpose, one of the most important tasks has been the sutdy of the amplifying effect of seismic movement due to ground characteristics, which is often a major cause responsible of the damage produced by earthquakes, even when their magnitude is not very high. In this article, the soil amplifying effects is considered according to two official sismorresistant regulations in Spain: the current Norma de Construccion Sismorresistente Espanola (NCSE-02) and the European regulation Eurocode 8 (EC-8). First, soils classification different criteria is analyzed and how this affects the soil factor and, particularly, the design seismic action in the form of response spectra. Subsequently, we compared the result of apllying both regulations to typical geological scenarios where the application of either regulation may cause notable differences. The second part of the paper deals with the comparison of NCSE-02 and EC-8 applied in the frame of a real case: the 11th May, 2011 Lorca earthquake. We compare the response spectra from both regulations to the actual response spectra derived from the accelerometric record of the earthquake at the Lorca station, and discuss which one fits it better. (Author)

  18. Analysis of the soil amplification factor in NCSE-02 and Eurocode-8 regulations: application to the 11{sup t}h May , 2011 Lorca earthquake; Analisis del efecto de amplificacion sismica por suelos en las normativas NCSE-02 y Eurocodigo 8: aplicacion al terremoto de Lorca del 11 de Mayo de 2011

    Energy Technology Data Exchange (ETDEWEB)

    Corsino Fernandez, C.; Garcia-Mayordomo, J.

    2014-07-01

    Earthquakes are one of the geological hazards which have produced more human and material loses in the history of manking. Seismic engineering has the purpose of studying the soil dynamic behavior in order to desing structures and buildings adapted to the effects triggered by earthquakes. Within this purpose, one of the most important tasks has been the sutdy of the amplifying effect of seismic movement due to ground characteristics, which is often a major cause responsible of the damage produced by earthquakes, even when their magnitude is not very high. In this article, the soil amplifying effects is considered according to two official sismorresistant regulations in Spain: the current Norma de Construccion Sismorresistente Espanola (NCSE-02) and the European regulation Eurocode 8 (EC-8). First, soils classification different criteria is analyzed and how this affects the soil factor and, particularly, the design seismic action in the form of response spectra. Subsequently, we compared the result of apllying both regulations to typical geological scenarios where the application of either regulation may cause notable differences. The second part of the paper deals with the comparison of NCSE-02 and EC-8 applied in the frame of a real case: the 11{sup t}h May, 2011 Lorca earthquake. We compare the response spectra from both regulations to the actual response spectra derived from the accelerometric record of the earthquake at the Lorca station, and discuss which one fits it better. (Author)

  19. Preoperational radiation surveillance of the WIPP Project by EEG for the years 1993 - 1995

    Energy Technology Data Exchange (ETDEWEB)

    Kenney, J.W.; Gray, D.H.; Ballard, S.C. [Environmental Evaluation Group, Carlsbad, NM (United States)

    1998-03-01

    Average {sup 241}Am, {sup 239+240}Pu and {sup 238}Pu concentrations measured in ambient air near the Waste Isolation Pilot Plant (WIPP) site during 1993, 1994 and 1995 are consistent with similar data reported by the U.S. Environmental Protection Agency (EPA) and Los Alamos National Laboratory (LANL) for Espanola, Pojoaque and Santa Fe, New Mexico. Through the use of replicate analyses of matrix blanks minimum detectable activity (MDA), minimum detectable concentration (MDC) and action levels (ACTL) were established for the Environmental Evaluation Group (EEG) measurement system. Using MDA data from fixed air sampler (FAS) filters and conservative assumptions applied in the National Council on Radiation Protection and Measurements (NCRP) Report 123 (NCRP 1996), it is shown that the EEG sampling and measurement methodology is capable of detecting effluent air emissions which would produce a dose that is approximately 1000 times below the 40 CFR 191 Subpart A limit of 2.5E{sup -4} Sv/y (25 mrem/y). A similar calculation using the NCRP worksheet with storm water effluent MDCs found the EEG measurement program capable of detecting actinide emissions which would result in a dose that is approximately 10 times below the dose limits in 40 CFR 191 Subpart A and 40 CFR 61 Subpart H.

  20. Preparação e caracterização de organobentonita modificada com ionenos alifáticos Preparation and characterization of aliphatic ionene-modified organobentonite

    Directory of Open Access Journals (Sweden)

    Arão P. Costa Filho

    2005-07-01

    Full Text Available A preparação de complexos bentonita-ionenos a partir da adsorção de tetrametil-[x,y]-ionenos, onde x= 2 e y= 4,6,10 ou 12, e o 2-hidróxi-3-cloro-ioneno, EPI-DMA, foi realizada com a finalidade de observar o comportamento do tamanho do espaçador do ioneno na expansão basal (d001 das camadas de uma bentonita comercial do Brasil. Os complexos foram caracterizados por espectrometria de absorção na região do infravermelho, termogravimetria, fluorescência e difração de raios X. A partir das análises por fluorescência e difração de raios X dos complexos, foi observado que os poli-quaternários de amônio são adsorvidos nas superfícies internas e externas da argila delaminada, acima da capacidade de troca catiônica, CTC = 91 meq/100g de argila (calculada a partir de dados de fluorescência de raios X. A expansão basal das camadas da argila com os diferentes policátions revelou que o tamanho do espaçador é o fator mais importante, independentemente das massas molares dos ionenos, tal como foi observado principalmente entre os complexos Bt-2,10- e Bt-2,12-ioneno, com massas molares de 12000 e 5000 g/mol, respectivamente.The preparation of bentonite-ionene complexes based on the adsorption of 2y-ionenes, where y = 4, 6, 10 or 12 and an ionene of the epichloridrin-dimethylamine EPI-DMA kind, was carried out in order to observe the behavior of the ionene spacer size in the expansion of the basal space (d-spacing, d001 of a Brazilian commercial bentonite. The complexes were characterized by adsorption spectromety in the infrared region, thermogravimetry, fluorescence and X-Ray diffraction. Ionenes were synthesized and characterized by infrared and nuclear magnetic resonance, the latter technique being useful for determining the average number molecular weight values. Based on the clay-ionenes complexes it could be observed that the ammonium polyquaternaries are adsorbed on the inner and outer clay surfaces, above the ion exchange

  1. Use of spectral data for estimating the relationship between iron oxides and 2:1 minerals with their respective reflectancesUso de dados espectrais para estimar a relação entre óxidos de ferro e minerais 2:1 com suas respectivas reflectâncias

    Directory of Open Access Journals (Sweden)

    Everson Cezar

    2013-09-01

    repetições por tratamento. As leituras espectrais das amostras de hematita, goethita, magnetita e bentonita foram realizadas por meio do equipamento FieldSpec 3 jr, o qual recobre a faixa espectral de 350 a 2500 nm. Após as leituras, foram escolhidos os intervalos que melhor representavam os minerais e realizaram-se as análises estatísticas a partir dos fatores de reflectância médios encontrados nestes pontos. Os resultados mostraram que a hematita, goethita e magnetita apresentam relação não linear com seus respectivos fatores de refletância, enquanto que a bentonita apresenta relação linear não só no intervalo estudado, mas em toda faixa coberta pelo equipamento. Desta maneira, conclui-se que quantidades relativamente pequenas destes óxidos de ferro são capazes de afetar a reflectância do solo da mesma forma que quantidades próximas de 100%. Com relação aos minerais 2:1 conclui-se que o aumento na proporção dos mesmos em uma determinada classe de solo leva a uma queda progressiva do fator de reflectância em todo o espectro-óptico, assim como descrito para outros elementos.

  2. Chemical signature of two Permian volcanic ash deposits within a bentonite bed from Melo, Uruguay

    Directory of Open Access Journals (Sweden)

    Liane M. Calarge

    2006-09-01

    Full Text Available A Permian bentonite deposit at Melo, Uruguay is composed of a calcite-cemented sandstone containing clay pseudomorphs of glass shards (0-0.50 m overlying a pink massive clay deposit (0.50-2.10m. The massive bed is composed of two layers containing quartz and smectite or pure smectite respectively. The smectite is remarkably homogeneous throughout the profile: it is a complex mixed layer composed of three layer types whose expandability with ethylene glycol (2EG 1EG or 0EG sheets in the interlayer zone which correspond to low-, medium- and high-charge layers respectively varies with the cation saturating the interlayer zone. The smectite homogeneity through the profile is the signature of an early alteration process in a lagoonal water which was over saturated with respect to calcite. Compaction during burial has made the bentonite bed a K-depleted closed system in which diagenetic illitization was inhibited. Variations in major, REE and minor element abundances throughout the massive clay deposit suggest that it originated from two successive ash falls. The incompatible element abundances are consistent with that of a volcanic glass fractionated from a rhyolite magma formed in a subduction/collision geological context.Um depósito Permiano de bentonita em Melo, Uruguai,é composto por um arenito com cimento calcítico contendo pseudomorfos de argila sobre detritos vítreos(0-0.50 m superpostos a um deposito maciço de argila rosado (0.50-2.10 m. A camada maciça é composta por dois níveis contendo quartzo e esmectita ou esmectita pura, respectivamente. A homogeneidade de esmectita ao longo do perfil é notável: trata-se de um interestratificado composto de três tipos de camadas, cuja expansibilidade com etileno-glicol (folhas 2EG, 1EG ou 0EG na zona interfoliar correspondentes a camadas com baixa, média e alta carga, respectivamente variam com o tipo de cátion que satura a zona interfoliar. A homogeneidade da esmectita ao longo do perfil

  3. Engineered barriers for radioactive waste confinement

    Directory of Open Access Journals (Sweden)

    Fernández, R.

    2011-09-01

    Full Text Available Nuclear power plants generate long-lived radioactive waste of high toxicity. The security assessment of repositories destined to definitive confinement of radioactive waste has been studied for several decades. Deep geological repositories are technically feasible and begin to be built by some pioneer countries. The scientific evaluation of interactions between the different engineered barriers is studied by laboratory experiments, natural analogues and modeling studies. The three methods are able to represent and validate the main geochemical processes that take place in the near field. This paper reviews the scientific and technical basis of the concept of geological disposal, with particular focus on the methods of study applied to the evaluation of geochemical stability of the bentonite barrier.

    Las centrales nucleares generan residuos radiactivos de elevada peligrosidad y permanencia en el tiempo. La evaluación de la seguridad de repositorios destinados al alojamiento definitivo de estos residuos lleva estudiándose desde hace varias décadas. El almacenamiento geológico es técnicamente factible y empieza ya a desarrollarse en países pioneros. La evaluación científica de las interacciones entre las distintas barreras de ingeniería se estudia mediante ensayos de laboratorio, análisis de análogos naturales y modelos teóricos. Las tres vías de estudio son capaces de representar y validar los principales procesos geoquímicos que tienen lugar en el campo cercano al repositorio. Este artículo revisa los fundamentos científicos y técnicos del concepto de almacenamiento geológico detallando, en particular, los métodos de estudio aplicados a la evaluación de la estabilidad geoquímica de la barrera de bentonita.

  4. Evaluación de la reducción de pelets utilizando carbón como agente reductor

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    Sandra Patricia Pérez Velásquez Alfonso López Díaz

    2010-11-01

    Full Text Available La obtención del acero se realiza a partir del mineralde hierro o de  la chatarra. En el primer caso el procesotiene lugar vía alto horno–convertidor; en el segundo,vía horno  eléctrico de  arco. Sin  embargo,  al hornoeléctrico también se pueden cargar los denominadospelets  prerreducidos  de  minerales  de  hierro,materiales metálicos  que  pueden  ser  obtenidos  apartir de  finos de mineral de hierro  (portador de  lacarga metálica,  finos de  carbón  (agente  reductor,finos  de  cal  (agente  desulfurante  y  bentonita(aglomerante, los cuales son convertidos en ovoidesmediante el empleo de un disco peletizador. El trabajomuestra  la  caracterización  realizada  a  las materiasprimas,  los  ensayos  de  reducibilidad  efectuados  apelets cargados en un horno tipo Linder –fabricadosa partir de dos yacimientos colombianos de mineralesde  hierro–  y  el  diseño  y  construcción  de  un  hornopara evaluar el comportamiento de los pelets durantela  reducción. Describe  los  equipos  y  analiza  sus

  5. Composition and diagenetic processes of sandstone and tuff deposits of the Cenomanian Cardiel Formation, Cardiel Lake area, province of Santa Cruz Composición y procesos diagenéticos de los depósitos de arenisca y toba de la Formación Cardiel (Cenomaniano, área Lago Cardiel, provincia de Santa Cruz

    Directory of Open Access Journals (Sweden)

    R.R. Andreis

    2007-06-01

    sandstone beds indicate main sediment transport directions towards the north, northeast, and less frequently to the southwest. The abundance of glass shards thorough this unit indicates a magmatic origin related to the volcanoes situated along the Andean Mountains possibly associated with alternating plinian and subplinian eruptions with brief phreato- plinian processes.La Formación Cardiel de alrededor de 200 m de espesor en el área estudiada, contiene diferentes tipos de depósitos volcaniclásticos, mayormente representados por tobas finas y bentonitas, y epiclásticos subordinados como areniscas líticas con colores castaño amarillentos, amarillentos u oliva claros, limolitas y arcilitas. Paleosuelos de tonalidad rojiza con algunas raíces axiales y débiles estructuras prismáticas aparecen en el tope de las limolitas, tobas o bentonitas. Las tufitas y tobas contienen los mismos componentes neovolcánicos, junto a abundantes vitroclastos y menor cantidad de fragmentos pumíceos. Diferentes tipos de vitroclastos pueden ser reconocidos dentro de esta unidad, mientras que los fragmentos pumíceos están representados por diversas variedades vesiculares. Clastos de tobas son frecuentes en las tufitas. Casi todas las muestras contienen montmorillonita diagenética y pedogenéticamente infiltrada, como así también zeolitas. Fueron identificadas clinoptilolita Ca-Na-K (Si/Al>4 predominante, y menor cantidad de analcima (Si/Al cerca de 3. La esmectita y la clinoptilolita pueden reemplazar los vitroclastos y los fragmentos pumíceos, o rellenar espacios, mientras que la esmectita también forma finos cutanes. La secuencia de procesos diagenéticos incluye la transformación (hidrólisis del vidrio a esmectita, y luego a zeolitas. Además, las zeolitas preceden el crecimiento de calcita (a veces remplazan vitroclastos o fragmentos pumíceos, y la infiltración de óxidos-hidróxidos de hierro. La variación vertical de las zeolitas puede ser explicada por la existencia de

  6. Colonialismo y santidad en las Islas Marianas: la sangre de los mártires (1668-1676

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    Coello de la Rosa, Alexandre

    2011-12-01

    Full Text Available In this article I analyze the conquest and colonization of the Marianas islands (1668-1676 as an example of the construction of the Catholic frontier in the Spanish possessions in the Pacific. One of the main objectives consists of analyzing martyrdom as one of the strategies used by the Jesuit missionaries to convert the Marianas islands to the Catholic faith. The first Jesuit martyrs −Diego Luis de San Vítores, Luis de Medina, and Sebastián de Monroy, SJ, among others− were elevated to the category of «distinguished heroes» of the Catholic Reformation who died as victims of the unbeatable barbarians in defence of Christian faith. Martyrdom, as longing and culmination of the missionary experience, turned those peripheral spaces into central points of reference wherein would end up rooting Christian dogma.

    En este artículo examino la conquista y colonización de las islas Marianas (1668-1676 como un ejemplo de la construcción de la frontera católica en las posesiones espanolas del Pacífico. Uno de los objetivos es analizar el martirio como uno de los mecanismos utilizados por los misioneros jesuitas para convertir las islas Marianas al catolicismo. Los primeros mártires −Diego Luis de San Vítores, Luis de Medina y Sebastián de Monroy, SJ, entre otros− se convirtieron en «héroes insignes» de la Reforma católica que murieron víctimas de los «bárbaros indómitos» en defensa de la fe. El martirio, como anhelo y culminación de la experiencia misionera, transformó aquellos espacios periféricos en puntos de referencia centrales donde acabaría triunfando el dogma cristiano.

  7. Influencia de los coadyuvantes tecnológicos utilizados en el proceso de elaboración de aceite de oliva sobre la cinética del proceso de digestión anaerobia del alpechín

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    Borja Padilla, R.

    1992-08-01

    Full Text Available A kinetic study of the anaerobic digestion of olive mill wastewater, which was obtained with the technological helper "Olivex" (Carbohydrase -pectinases, cellulases and hemicellulases- from the Aspergillus aculeatus was carried out. An identical wastewater, obtained without this enzymatic formulation was also used. The process was carried out in bioreactors with microorganisms immobilized on two micronized clay supports, Sepiolite and Bentonite. The methane volume-time data pairs obtained were used to calculate the specific rate constant, Ko, by using the Roediger's equation. A decrease of the specific rate constant value was observed over the substrate concentration studied when the volume of wastewater added was increased; this confirmed the occurrence of an inhibition process, which was more marked for the olive mill wastewater obtained with Olivex. The Levenspiel's model was used to obtain the inhibition constants of this process.

    Se ha efectuado un estudio cinético del proceso de digestión anaerobia de un alpechín obtenido con el coadyuvante tecnológico "Olivex" (Carbohidrasa -pectinasas, celulasas y hemicelulasas- procedente de Aspergillus aculeatus en comparación con un testigo obtenido sin esta formulación enzimática. El proceso se ha realizado en biorreactores con microorganismos inmovilizados en dos soportes micronizados arcillosos, Sepiolita y Bentonita. A partir de los datos volumen de metano-tiempo, se calculan las constantes específicas de velocidad, Ko, utilizando la ecuación de Roediger. Dentro del rango de concentración de sustrato estudiado se observa una disminución de la constante cinética al aumentar el volumen de residuo añadido a los digestores lo que confirma la existencia de un proceso de inhibición, que es más acusado en el caso del alpechín obtenido con Olivex. Para determinar las constantes de inhibición del proceso se utiliza el modelo propuesto por Levenspiel.

  8. Obtenção de nanocompósitos condutores de montmorilonita/polipirrol: efeito da incorporação do surfactante na estrutura e propriedades

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    Sílvia Daniela Araújo da Silva Ramôa

    2014-01-01

    Full Text Available Nanocompósitos de montmorilonita/polipirrol (MMT/PPy foram preparados a partir da polimerização in situ do pirrol na presença de argila, bentonita sódica natural, (MMT-Na+ em solução aquosa com ou sem surfactante aniônico, dodecil sulfato de sódio (SDS, utilizando-se o cloreto de ferro (III hexahidratado (FeCl3.6H2O, como oxidante. A estrutura e propriedades dos nanocompósitos obtidos pela polimerização in situ do pirrol na presença de SDS (MMT/PPy.SDS e sem surfactante (MMT/PPy foram avaliadas e comparadas a partir da espectroscopia de infravermelho com transformada de Fourier (FTIR, difração de raios X (DRX, microscopia eletrônica de varredura (MEV, microscopia eletrônica de transmissão (MET, análise termogravimétrica (TG e método padrão quatro pontas. Os difratogramas dos nanocompósitos revelaram que o espaçamento basal d001 da MMT (1,42 nm foi alterado para valores maiores, indicando a intercalação do PPy na MMT para ambos os nanocompósitos obtidos. Os difratogramas e as imagens de MET e MEV dos nanocompósitos de MMT/PPy.SDS confirmaram que a presença do SDS na reação promoveu, além da intercalação, esfoliação parcial da argila. Os nanocompósitos MMT/PPy.SDS apresentaram condutividade elétrica (9,50 S/cm maior do que o nanocompósito de MMT/PPy (4,44 S/cm. A presença da argila melhorou de forma significativa a estabilidade térmica do PPy.

  9. Purificação e organofilização em escala piloto de argilas bentoníticas com tensoativo não iônico e aplicação em nanocompósitos poliméricos

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    Wilma Sales Cavalcanti

    2014-08-01

    Full Text Available O objetivo deste trabalho foi a purificação e organofilização em escala piloto de dois tipos de argila bentonita (cinza e verde com tensoativo não iônico e a aplicação destas argilas em nanocompósitos com matriz de Polipropileno (PP. As argilas foram purificadas e em seguida organicamente modificadas com tensoativo não iônico tornando-se organofílicas, sendo denominadas de CPO e VPO respectivamente, e caracterizadas por Análise Granulométrica por Difração a Laser (AG, análise química por Fluorescência de Raios X (EDX, Difração de Raios X (DRX e espectroscopia no infravermelho (IV. Os resultados de AG e EDX mostraram redução significativa do teor de areia e da sílica livre na forma de quartzo confirmando que houve a purificação da argila. Os resultados de DRX e IV mostraram que a organofilização em escala piloto das argilas foi realizada com sucesso. Os compósitos contendo 3pcr de argila foram caracterizados por DRX, Calorimetria exploratória diferencial (DSC, Termogravimetria (TG e propriedades mecânicas. As análises por DRX indicaram formação de um nanocompósito com estrutura intercalada para o sistema PP/E-GMA/CPO, enquanto para o sistema PP/E-GMA/VPO formou-se um micro-compósito. Os resultados de DSC indicaram que as argilas não influenciaram na temperatura de fusão do PP. Os resultados de TG indicaram que as argilas CPO e VPO melhoraram a estabilidade térmica do PP. O sistema PP/E-GMA/CPO foi o que apresentou maior estabilidade térmica e maior módulo. As resistências à tração e ao impacto dos compósitos não apresentaram melhora significativa em relação ao PP puro. Mesmo assim, este comportamento é importante uma vez que as propriedades mecânicas do PP não foram deterioradas.

  10. Influência da adição de uma carga nanoparticulada no desempenho de compósitos poliuretano/fibra de juta Influence of a nanoparticulate filler addition on the mechanical properties of polyurethane/jute fiber composites

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    José R. A. Neto

    2007-03-01

    Full Text Available Neste trabalho as propriedades mecânicas de um compósito, formado a partir de uma matriz de poliuretano derivado do óleo de mamona e reforçada por um tecido tramado de juta, foram avaliadas. O efeito da adição de pequenos teores de bentonita cálcica e sódica sobre as propriedades mecânicas da matriz de poliuretano e de compósitos poliuretano/juta também foi investigado. Os resultados indicam que a incorporação de fibra de juta à matriz poliuretana promoveu melhora significativa nas propriedades sob tração dos compósitos. A adição de pequenos teores de argila à matriz alterou o desempenho mecânico dos compósitos, porém os resultados não foram os esperados. O compósito híbrido poliuretano/argila/fibra de juta, contudo, apresentou propriedades mecânicas superiores às dos compósitos reforçados unicamente com tecido de juta, o que indica uma atuação sinérgica dos reforços híbridos argila/juta.In this work the mechanical properties of polyurethane/jute fiber composites were evaluated as a function of fiber content and mineral filler addition. A polyurethane (PU derived from castor oil was used as the matrix and hessian cloth as reinforcement. The effect of the incorporation of small amounts of local clay (bentonite, in its calcium and sodium forms, on the mechanical properties of polyurethane/jute composites was also investigated. The results indicate that the tensile properties of the composites substantially increased with jute fiber addition and that although the mechanical properties of the matrix were affected by the addition of nanoparticulate clay, the improvement was not as expected. This was attributed to poor mixing and dispersion of the filler, which was confirmed by SEM. A synergistic effect was observed for the hybrid clay/jute fiber composites, with considerable improvement in the mechanical performance of the hybrid composites.

  11. Estudo do comportamento reológico das argilas bentoníticas de Cubati, Paraíba, Brasil Rheological behavior study of bentonite clays from Cubati, Paraíba, Brazil

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    R. R. Menezes

    2009-12-01

    Full Text Available O estado da Paraíba possui jazidas de bentonitas utilizadas comercialmente para uma vasta gama de setores tecnológicos. No entanto, esses jazimentos estão se exaurindo, após dezenas de anos de exploração. Assim, este trabalho tem por objetivo dar prosseguimento à caracterização de argilas bentoníticas de Cubati, PB, estudando o comportamento reológico das dispersões argila-água de modo avaliar seu desempenho para fluidos de perfuração de poços de petróleo base água. As amostras estudadas foram secas a 60 ºC e determinou-se sua capacidade de troca de cátions. As argilas foram transformadas em sódica por tratamento com Na2CO3 e em seguida realizou-se o estudo do comportamento reológico das dispersões. As viscosidades, aparente e plástica, o volume de filtrado, os parâmetros reológicos do fluido e a sua força gel foram determinados. Os resultados evidenciaram que cada amostra apresenta um teor ótimo de carbonato de sódio e que as dispersões argila-água possuem um comportamento pseudo-plástico e tixotrópico. Duas amostras apresentam potencial para utilização como agentes viscosificantes para fluidos de perfuração.The bentonites of the state of Paraíba, Brazil, are commercially used in numerous technological sectors, particularly in oil drilling muds. However, these bentonite deposits are becoming exhausted due to several years of exploitation. Thus, the aim of this work was continue the characterization of the bentonites from Cubati, Paraíba, studying the rheological behavior of water-clay suspensions, evaluating their viability to be used in oil drilling muds. The samples were dried at 60 ºC and, their cation exchange capacity was determined. The natural bentonite clays were transformed in sodium bentonite by addition of concentrated Na2CO3 solution, then the suspensions rheological study was performed. The apparent and plastic viscosities, water loss, rheological parameters and the gel force were determined

  12. La flexibilidad laboral: significados y consecuencias Labour Flexibility: Meanings and Consequences

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    Juan Ignacio Martínez Pastor

    2011-09-01

    Full Text Available

    Los objetivos del articulo son 1 analizar las consecuencias de la flexibilidad laboral en el curso vital de los individuos, 2 asi como saber si la flexibilidad ha socavado o reforzado la importancia de las clases sociales, de la educacion y del genero en distintos aspectos concernientes al curso vital, sobre todo relacionados con el empleo en Espana. La peculiaridad espanola con respecto a la flexibilidad radica en la alta proporcion de contratos temporales. La mayor diferencia entre estos contratos y los indefinidos es su menor coste de despido. La manera en la que el Estado del Bienestar ha introducido la flexibilidad ha logrado un equilibrio de riesgos entre generaciones, por lo que no puede decirse que haya unos claros ganadores o perdedores. Los datos indican que los efectos de la flexibilizacion sobre el curso vital de los individuos son mucho mas modestos de lo que las hipotesis preven. Asimismo, la flexibilización no ha mermado la importancia de las clases sociales ni de los niveles de estudio para explicar la posición de los individuos en el mercado laboral, aunque tampoco hay una clara evidencia de que las brechas entre los individuos de distintas clases ocupaciones o con distintos niveles de estudio hayan aumentado en Espana.

    The objectives of the paper are 1 to analyse the effects of labour flexibility on individuals from a lifecourse perspective and 2 to know whether flexibility has undermined or reinforced the effects of social classes, education and gender on several aspects concerning the life-course, above all those related to employment in Spain. The peculiarity of the Spanish case lies in the proportion of fixed-term contracts. The greatest difference between these contracts and permanent contracts is not the job to be done, or even its temporary or permanent nature, but rather the lower layoff cost. The way that the Welfare State has introduced flexibilisation has achieved a balance of risks between the generations

  13. Lo global y lo local en la colonialidad: prácticas cotidianas en la Nueva Población y Fuerte de Floridablanca (San Julián, Siglo XVIII The global and the local in coloniality: daily practices at Nueva Población y Fuerte de Floridablanca, San Julián Bay, during the eighteenth century

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    Marcia Bianchi Villelli

    2012-07-01

    Full Text Available La expansión colonial de la sociedad moderna fue estudiada recientemente desde varias disciplinas y perspectivas. Desde la arqueología histórica sudamericana en particular se ha discutido la naturaleza homogeneizante de este proceso global en función de reevaluar los diversos contextos específicos en el tiempo y en el espacio. Este trabajo se centra en la articulación entre la escala global y la particular para discutir el lugar asignado a los agentes y procesos locales en la constitución de las sociedades coloniales. A partir de los aportes de la teoría poscolonial latinoamericana, se busca discutir el concepto de sociedad moderna, para así reconocer los legados coloniales. Esta discusión se ilustra con el estudio de la colonización española de la costa patagónica a fines del siglo XVIII, en particular, el caso de la Nueva Población y Fuerte de Floridablanca (Bahía de San Julián, 1780-1784. El estudio de la reproducción y transformación social en Floridablanca se centró en los escenarios sociales no contemplados por la Corona espanola en su planificación colonial. El énfasis en las prácticas cotidianas en una escala pequena permitió un abordaje a la tensión entre las categorías definidas desde el orden colonial y su puesta en práctica.Recently, the colonial expansion of modern society has been studied from various disciplines and theoretical perspectives. South American historical archaeology in particular has discussed the homogenizing nature of this global process in order to reevaluate specific contexts through time and space. This paper is centered on the articulation of the global and the particular and the place assigned to agents and local processes in the formation of colonial societies. Latin American postcolonial theory shines light on this debate through the critical assessment of modern discourse and the acknowledgement of colonial legacies. The discussion is illustrated with a case study from the Spanish

  14. Subjective nutritional val oration generated by the patient in the hematology oncology users

    International Nuclear Information System (INIS)

    Everybody knows that all protein calorie malnutrition is not only the cause of death in cancer patients but also affects the good performance treatment as well as their quality of life. Because of that common complication, it is necessary the use of simple tools to detect its occurrence. A recent study called NUPAC perceive that 52% of patients in advanced stages presents protein calorie malnutrition. The tool used was the subjective global valuation which is generated by the patient and is based on clinical parameters. The Eastern Cooperative Oncology Group showed that a weight loss predicts the treatment response reducing the survival and quality of life. In 2002 a study carried out in the Nutritional Support Unit, University Hospital Vall d'Hebron in Barcelona recorded that at admission only 16,7% of patients were within normal nutritional values, 38.9% were undernourished moderate and 44.4% severe malnutrition, nutritional assessment at discharge showed no significant changes in relation to income hospital. 81.2% of these patient had a prescribed diet v / o of which 43.1% needed some supplements type and only 23% an artificial diet. The valuation method used was also generated by the subjective global valuation patient. Considering the impact that the nutritional status has in the evolution of neoplastic disease we saw the need to make a job using the above tool applied by personnel out of the nutrition in order to evaluate and identify patients who need or no simple nutritional intervention. Our study was conducted in the period of August-October in 2004 and included 50 users, of both sexes (26 males and 24 females) treated with polychemotherapy (which were excluded in the first series of MDT) and either ambulatory or hospitalized at transplant unit or conventional sector in Hematology-Oncology Service at the Asociacion Espanola Primera de Socorros Mutuos. Part of the questionnaire was completed by the own user and It also were performed by anthropometric

  15. Comportamento termomecânico de compósitos ativos preparados com nanocompósitos epóxi/argila organofílica e fios de liga Ni-Ti com memória de forma Thermomechanical behavior of active composites prepared with epoxy/organoclay nanocomposites and Ni-Ti shape memory alloy wires

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    Artur S. C. Leal

    2012-01-01

    Full Text Available Neste trabalho, nanocompósitos epóxi/argila organofílica foram selecionados como matriz por apresentarem valores de temperatura de transição vítrea (Tg e estabilidade térmica suficientemente alta para que fios de uma liga com memória de forma (LMF possam ser incorporados. Para tanto, quatro frações volumétricas de fios LMF de Ni-Ti (1,55, 2,56, 3,57 e 4,54% foram embebidas na matriz epoxídica diglicidil éter do bisfenol-A (DGEBA, reticulada com a amina aromática 4,4’-diamino difenil sulfona (DDS contendo 1 pcr da argila bentonita purificada organofiliada (APOC. A formação do nanocompósito foi confirmada por análise de difração de raio X, enquanto a transformação de fase dos fios de Ni-Ti foi determinada por análise dinâmico-mecânica (DMA. As amostras dos compósitos ativos preparados a partir da matriz de nanocompósito e fios de Ni-Ti foram caracterizadas principalmente por DMA. De acordo com os resultados obtidos foi constatada uma recuperação do módulo de armazenamento do compósito ativo durante o aquecimento na faixa de transformação de fase dos fios de Ni-Ti quando a fração volumétrica foi mantida em torno de 3,5%.In this work, epoxy/organoclay nanocomposites were selected as matrix for presenting high enough glass transition temperature (Tg and thermal stability values in order to be incorporated in shape memory alloys (SMA. Four volume fractions of SMA wires containing Ni-Ti (1.55, 2.56, 3.57 and 4.54% were embedded in diglycidyl ether of bisphenol A (DGEBA, cured with the aromatic amine 4,4’-diamino diphenyl sulfone (DDS and containing 1 phr of purified organobentonite (APOC. The formation of nanocomposite was confirmed by X ray diffraction analysis, while the phase transformation of Ni-Ti wires was determined by dynamic mechanical analysis (DMA. Samples of the active composites prepared from nanocomposite matrix and Ni-Ti wires were mainly characterized by DMA. A recovery of the storage modulus of

  16. Germinação de sementes de cenoura osmoticamente condicionadas e peletizadas com diversos ingredientes Germination of carrot seed primed and pelleted with several ingredients

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    Warley M Nascimento

    2009-03-01

    Full Text Available A semente de cenoura caracteriza-se por ser relativamente pequena, o que dificulta o processo de distribuição, tornando a mecanização por semeadeiras convencionais uma prática difícil. A técnica da peletização tem sido utilizada visando a melhoria da distribuição de sementes e o estabelecimento de plântulas no campo. As sementes peletizadas geralmente apresentam menor velocidade de germinação quando comparadas com as sementes nuas do mesmo lote. O condicionamento osmótico tem sido utilizado para aumentar a velocidade de germinação de sementes. Neste estudo foram avaliados materiais cimentantes para a peletização de sementes e verificadas as relações existentes entre o condicionamento osmótico e a germinação das sementes peletizadas de cenoura cv. Alvorada. A peletização foi feita utilizando-se, como material de enchimento, a mistura de microcelulose e areia fina em volumes iguais e, para enchimento foram avaliados cinco materiais cimentantes: bentonita, methocel, opadry, rhoximat e goma arábica. Sementes peletizadas receberam ou não o acabamento com iriodin. Uma testemunha (sementes nuas foi incluída no ensaio. Em outro estudo, sementes foram osmoticamente condicionadas em solução aerada de polietileno glicol e peletizadas imediatamente após o condicionamento osmótico ou após a secagem. Os produtos rhoximat e opadry apresentaram as melhores características como material cimentante, formando uma fina camada de revestimento, que resultou na formação de péletes com superfície lisa, uniforme e ótima aparência externa. Em geral, péletes apresentaram uma ligeira redução na porcentagem e na velocidade de germinação, em comparação às sementes não peletizadas, com diferenças maiores para os péletes que receberam o acabamento com iriodin. O condicionamento osmótico aumentou a velocidade de germinação das sementes peletizadas de cenoura.Carrot seeds are small and the distribution in the field by

  17. Desempenho de perus de corte alimentados com níveis crescentes de aflatoxinas, com ou sem adição de adsorvente Turkey performance fed with increasing aflatoxins levels, with or without adsorvent inclusion

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    Janio Morais Santurio

    1998-03-01

    Full Text Available Este trabalho foi realizado durante o verão de 1995/96 com o objetivo de determinar o nível de aflatoxinas (AFL capaz de causar prejuízos no desempenho de perus de corte criados sob condições ambientais de baixo desafio, bem como avaliar a eficácia da adição de bentonita sódica natural (BSN como um adsorvente. Foram utilizados 1008 perus de corte, alojados em 84 boxes seguindo um delineamento experimental de blocos casualizados com 14 tratamentos distribuídos em um arranjo fatorial 7x2, sendo 7 níveis de adição de AFL, (0, 10, 50, 100, 500, 1000 e 2000ppb e 2 níveis de adição de BSN (0 e 0,5%. Aos 21 dias de idade, as aves alimentadas com as dietas sem adição de BSN mostraram uma redução significativa (PThis experiment was carried out in the 1995/96 summer to determine the aflatoxin (AFL levels ability to decrease turkey performance raised under excellent environmental conditions and also to avaluate a natural sodium bentonite (NSB efficiency as an adsorbent. One thousand and eight poults were housed in 84 floor pens following a randomized complete block design with 14 treatments arranged in a 7x2 factorial, with 7 AFL levels (0, 10, 50, 100, 500, 1000 and 2000ppb and 2 NSB levels (0 and 0.5%. At 21 days of age the birds fed without NSB showed body weight gain (BWG and feed intake (FI reduction (P<0.05 from 500ppb or more of AFL, whereas the birds fed with NSB showed BWG and FI reduction (P<0.05 only from 1000ppb or more of AFL. These same results were observed at 40 days of age, but at 70 days, the BWG and FI reduction was statistically significant (P<0.05 from 500ppb or more of AFL, with or without NSB inclusion. In general, birds fed with NSB had about 15 to 20% less BWG and FI reduction than birds fed without NSB. The feed conversion (FC was less affected by AFL levels, although it worsened with increasing AFL levels. AFL have greatly affected the mortality rate. At 21 days of age the birds fed with 1000 and 2000pbb of

  18. Tratamiento de salmueras de fermentación de aceitunas verdes

    Directory of Open Access Journals (Sweden)

    Garrido Fernández, A.

    1992-10-01

    de polisulfona de 1.000 daltons de corte molecular es lo más adecuado, trabajando a una presión de 18 bars. Un pretratamiento con bentonita (2 g/l, temperatura entre 30 y 45°G y la menor concentración inicial de polifenoles y sólidos en suspensión aumentan el rendimiento de forma considerable. En principio, un estudio económico aproximado de costes indica que la regeneración por cualquiera de los dos sistemas daría una salmuera regenerada a un precio algo inferior al obtenido al preparar el líquido de gobierno para envasar a partir de sus componentes.

  19. Obtenção de argilas organofílicas purificadas através de tensoativos iônicos e não iônicos visando uso em fluidos de perfuração base óleo Getting purified organoclays by ionic and non-ionic surfactant aiming use in oil based drilling fluids

    Directory of Open Access Journals (Sweden)

    J. M. R. Costa

    2012-12-01

    Full Text Available Em perfurações de petróleo sensíveis ao contato com água, torna-se necessária a utilização de fluidos de perfuração base óleo. Nestes casos, utilizam-se argilas organofílicas, que são obtidas a partir de argilas bentoníticas purificadas e tratadas com a adição de tensoativos. A utilização do hidrociclone pode representar uma ferramenta eficiente e de custo acessível para purificar argilas naturais em escala industrial. Este trabalho tem por objetivo estudar a purificação de argilas bentoníticas utilizando-se um hidrociclone, visando o desenvolvimento de argilas organofílicas para uso em fluidos de perfuração base óleo. As caracterizações das amostras das argilas estudadas - Brasgel PA e Chocolate - foram efetuadas por meio das técnicas: análise granulométrica por difração de laser, difração de raios X (DRX e análise química por fluorescência de raios X. A caracterização das argilas organofílicas obtidas foi efetuada por meio dos seguintes métodos: DRX e por uma modificação do inchamento de Foster. Os resultados mostram que o processo de purificação foi eficiente na redução de impurezas presentes na bentonita e que a argila organofílica purificada tratada com Praepagen WB e Imidazolina Oléica Vegetal apresenta valores de inchamento de Foster em éster, óleo diesel e parafina superiores aos obtidos com argilas organofílicas sem purificação (natural, e evidenciando maior afinidade com o tensoativo Praepagen WB.Oil drilling in sensitive contact with water, becomes required the use of oil base drilling fluids. In these cases, organoclays are used, which are made from clay bentonite purified and treated with surfactants addition. The use of the hydrocyclone can be a effective tool and affordable for purifying clays in industrial scale. This work aims to study the purification of clays bentonite using a hydrocyclone, aiming to develop organoclays for use in oil base drilling fluids. The

  20. A Cafe Scientifique for Teens

    Science.gov (United States)

    Hall, M.; Mayhew, M.

    2008-12-01

    It is well-known to those pursuing the quest to connect scientists to the public that an exceedingly hard-to- reach demographic is people of high school age. Typically, kids may tag along with their parents to museums until they reach adolescence, and then don't again appear in museums until they themselves have children. We have addressed this demographic challenge for free-choice-learning by developing a Cafe Scientifique program specifically for high school students. The Cafe Scientifique model for adults was developed in England and France, and has now spread like wildfire across the U.S. Typically, people come to a informal setting like a cafe, socialize and have food and drink, and then hear a short presentation by a scientist on a hot science topic in the news. This is followed by a period of lively discussion. We have followed this model for high school age students in four towns in northern New Mexico--Los Alamos, Santa Fe, Espanola, and Albuquerque--which represent a highly diverse demographic. We started this novel project with some trepidation, i.e. what if we build it and they don't come. But the program has proven popular beyond our expectations in all four towns. A part of the secret of success is the social setting, and-especially for this age group-the food provided. But we have also found that the kids are genuinely interested in the science topics, directing their own program, and interacting with scientists. We have often heard statements like, "I think it is important to be well-informed citizens". One of the most important aspects of the Cafes for the kids is to be able to discuss and argue about issues related to the science topic with the presenter and each other. It is an important part of the popularity that the Cafes do not involve school or parents, but also that we have strived to give the kids ownership of the program. Each town has a Youth Leadership Team-open to any teen-that discusses and prioritizes potential topics, conducts

  1. Puertollano IGCC Power Plant; Central de Gasificacion Integrada en Ciclo Combinado de Puertollano

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-07-01

    The Puertollano IGCC Power Plant, rated 335 MW and located in Puertollano, Ciudad Real, in the central area of Spain, is a project led by ELCOGAS, a company incorporated by the European utilities ENDESA, ELECTRICITE DE FRANCE, IBERDROLA HIDROCANTABRICO ELECTRICIDADE DE PURTUGAL, ENEL and NATIONAL POWER and the technology and equipment suppliers SIEMENS, KRUPP UHDE and BABCOCK WILCOX ESPANOLA. IGCC technology is based in a process of coal gasification to obtain a clean combustion synthetic gas, integrated with a combined cycle, agas and steam, electricity-generating unit. The energy efficiency which is aimed to achieve at the Plant is 46% in ISO conditions. The Gasification unit uses the process of pressurised entrained flow for coal gasification. The gas is produced by the reaction of coal with oxygen at high temperatures, of up to 1600 degree centigree. This process is capable of gasifying a wide variety of types and qualities of coal for the production of a synthetic fuel gas. In the case of Puertollano, the raw fuel is a 50% mixture by weight of local coal and petroleum coke. The oxygen needed in the process and the nitrogen used for covering the fuel is generated in the Air Separation. The Gas Cleaning and Sulphur Recovery Unit clean the gases from contaminants and solid particles before to send them to the Gas Turbine. The clean gas is burnt in gas turbine of the Combined Cycle Plant, producing electricity. The exhaust gases feed a heat recovery steam generator, which produces steam used to generate additional electricity in a conventional steam turbine. The gas turbine is capable of operating both with synthetic gas and with natural gas, allowing operation flexibility. The net output of the plant up to December 1999 was 3.061 GWh, from them 344 GWh were produced with synthetic gas. This project has an important technological value, being the first power plant which uses coal gasification to feed a combined cycle in Spain and being also the biggest power plant

  2. Efeito da adição de componentes inorgânicos na resistência mecânica de moldes de areia para fundição Effect of addition of inorganic components on the mechanical strength of sand molds for casting

    Directory of Open Access Journals (Sweden)

    M. S. Cilla

    2012-03-01

    Full Text Available O processo de fundição mais rápido, econômico e convencional é o de moldagem em areia a verde, onde o ligante principal é uma argila umedecida (bentonita. Entretanto, devido a exigências tecnológicas, são utilizados também ligantes tóxicos como resinas furânicas, fenólicas ou uretânicas. Novas tecnologias vêm sendo desenvolvidas para a recuperação e inertização das areias, porém as resinas disponíveis atualmente têm como limitação "ecológica" sua origem química. Após sua utilização estes moldes são descartados, e assim, os ligantes tóxicos tornam-se um problema ambiental. Desta maneira, a substituição destes ligantes por compostos orgânicos derivados de fontes renováveis como a resina poliuretana derivada do óleo de mamona minimiza os impactos ambientais, conduzindo o processo de fundição rumo à sustentabilidade, necessária devido ao aumento do rigor da legislação ambiental. Devido ao comportamento térmico do poliuretano vegetal, que se decompõem de maneira mais acentuada quando exposto a altas temperaturas quando comparado aos ligantes orgânicos tradicionais a adição de componentes inorgânicos se faz necessária como promotora da ligação entre os grãos de areia e conseqüente coesão dos moldes durante a etapa de fusão. Neste sentido, o uso de diagramas de fases na previsão do surgimento de fase líquida pela adição de componentes inorgânicos à mistura areia/resina em moldes de areia para fundição e seu efeito na resistência mecânica dos moldes em altas temperaturas, funciona como ferramenta teórica no auxílio à determinação das composições dos moldes de acordo com sua solicitação térmica durante a fusão. Testes iniciais de moldagem e resistência mecânica a temperatura ambiente mostraram que a resina poliuretana derivada da mamona apresenta resultados comparáveis aos das resinas comerciais. Também a adição dos componentes inorgânicos e seu efeito quando submetido a