WorldWideScience

Sample records for zeolita natural modificada

  1. SÍNTESIS SELECTIVA DE BENZALDEHÍDO USANDO ZEOLITAS MODIFICADAS CON METALES DE TRANSICIÓN

    Directory of Open Access Journals (Sweden)

    Clara Saux

    2012-01-01

    Full Text Available Se estudió la oxidación selectiva de estireno para la obtención de benzaldehído sobre zeolitas ZSM-5 modificadas con diferentes metales de transición (cromo, cobalto, hierro, zinc, manganeso y cobre y utilizando peróxido de hidrógeno como oxidante. Dado que los mejores resultados se obtuvieron utilizando Cr-ZSM-5, estos materiales se estudiaron evaluando el efecto del tiempo de reacción, la masa de catalizador, la relación molar estireno/hidroperóxido, la naturaleza del solvente y la temperatura de reacción. Los mejores resultados de las condiciones evaluadas se obtuvieron trabajando con una relación molar sustrato/oxidante de 0,45 y utilizando acetonitrilo como solvente, dado su carácter aprótico y de mayor polaridad de los solventes evaluados (acetonitrilo, acetona, 2-butanol y 2-propanol. El aumento en la temperatura de reacción mostró un incremento en la conversión de estireno, el cual se desaceleró al superar los 60 oC por descomposición térmica del peróxido de hidrógeno.

  2. ELIMINACIÓN DE COLORANTES CATIÓNICOS USANDO OZONO, ZEOLITA NATURAL Y OZONO/ZEOLITA CATIONIC DYES REMOVAL USING OZONE, NATURAL ZEOLITE, AND OZONE/ZEOLITE

    Directory of Open Access Journals (Sweden)

    Héctor Valdés

    2009-12-01

    Full Text Available En este trabajo se comparan resultados experimentales de remoción azul de metileno (MB utilizando tratamientos basados en la oxidación con ozono (O3, la adsorción con zeolita natural (ZN, y tratamiento simultáneo de adsorción y oxidación con ozono en presencia de zeolita natural (O3/ZN. Se evalúa, a escala de laboratorio, el efecto del pH (2-8 y la presencia de sustancias atrapadoras radicales libres (iones acetatos en la velocidad de remoción y en la eficiencia de los procesos. Los experimentos se realizaron en un reactor diferencial compuesto por un estanque de 1 dm³ y una columna de 19 cm³ de capacidad. El ozono fue generado a razón de 5 g O3/h. Los resultados mostraron que el sistema simultáneo de oxidación/adsorción O3/ZN incrementa la velocidad de remoción del MB con respecto a los procesos separados de ozonización y adsorción con zeolita. En presencia de sustancias atrapadoras de radicales, se observó un 70% de disminución en la velocidad de remoción de MB cuando se empleó el tratamiento con O3 y sólo un 25% cuando se utiliza el tratamiento combinado O3/ZN. Los resultados sugieren que la reacción de oxidación del MB en el sistema tiene lugar fundamentalmente sobre la superficie de la zeolita.This paper compares experimental results on methylene blue (MB removal systems based on ozone oxidation, zeolite adsorption, and simultaneous adsorption-oxidation using ozone in the presence of natural zeolite. The effect of pH (2-8, and the presence of radical scavengers (sodium acetate on process rates and removal efficiencies are assessed at laboratory scale. The experimental system consisted of a 1L differential circular flow reactor and an ozone generator rated at 5 g O3/h. Results show that ozone oxidation combined with zeolite adsorption increases the overall MB oxidation rate with respect to ozonation process and zeolite adsorption. In presence of free radical scavenger, only a 25% of reduction on MB removal rate are

  3. REMOCIÓN DE COBRE Y NÍQUEL POR INTERCAMBIO CATIÓNICO CON UNA ZEOLITA NATURAL

    Directory of Open Access Journals (Sweden)

    Arnoldy Estupiñan

    2010-10-01

    Full Text Available Se empleó la zeolita natural clinoptilolita, para remover cobre y níquel de aguas residuales de una industria de galvanotecnia. La capacidad de intercambio determinada para la zeolita transformada al estado homoiónico sódico, fue de 0,794 meq/g para cobre y 0,447 meq/g para níquel. Se realizaron ensayos en cochada y en columna, alcanzando éste último un mayor acercamiento al equilibrio. En los ensayos de regeneración, la zeolita sódica concentró el cobre hasta 23,5 veces con respecto al valor que presenta en los enjuagues de los baños de recubrimiento en medio ácido, mostrando su potencialidad para usarla en el tratamiento de estos residuos, por su efectividad y bajo costo.

  4. REMOCIÓN DE PLOMO EN AGUA A PARTIR DE MATERIAL NANOESTRUCTURADO, NANOTUBOS DE CARBONO SOPORTADOS EN ZEOLITA NATURAL

    Directory of Open Access Journals (Sweden)

    Holanda I. Cruz

    2017-01-01

    Full Text Available En este trabajo se realizó la cinética de remoción de plomo en agua con un material nanoestructurado, nanotubos de carbono soportados en zeolita (NTC-ZN, y con zeolita natural (ZN. La zeolita utilizada proviene de los Valles Centrales de Oaxaca, México. El material nanoestructurado se sintetizó por el método de aspersión pirolítica bajo condiciones especificas; se caracterizó por microscopía electrónica de barrido y de transmisión (SEM y TEM y determinación de área superficial (BET. Los materiales se probaron con una solución de plomo a una concentración de 10 ppm bajo condiciones de agitación y filtrado a vacío. El filtrado se caracterizó por espectrometría de masas con plasma acoplado inductivamente (ICP-MS. Los porcentajes de remoción fueron de 99.96% para NTC-ZN y 99.27% para la zeolita natural en 120 minutos. Sin embargo un 94.5% de remoción se presenta en un tiempo 6 veces menor con el híbrido que con ZN.

  5. Diagramas de eslabilidad de zeolitas. I. Zeolitas en ambientes confinados alcalinos

    Directory of Open Access Journals (Sweden)

    La Iglesia, A.

    1989-12-01

    Full Text Available The stability fieds of zeolites in saline alkaline-lake deposits has been studied. Thermodynamical equilibriums were calculed by ussing a method of stimating the Gibbs free energies of formation of zeolites. We have studied the following stability fields: - Diagram c1inoptilolite-erionite-phillipsite.- Diagram analcime-clinoptilolite-chabazite-erionite-mordenite-phillipsite.- Diagram K-feldspar-zeolites in saline alkaline-lake deposits.The obtained stability diagrams show the influence of silica activity, water activity and alkaline ions activity on equilibrium relationship between analcime and alkalic silicic zeolites, and or feldspar and zeolites. pH influence on the solubility zeolites has been also studied. These results show, at pH below 10, that the most silicic zeolites (clinoptilolite and mordenite are more stable than low silicic ones (analcime and chabazite. However, at pH above 10, the low silicic zeolites are the most stable phases.Se estudia la estabilidad de las zeolitas que aparecen en ambientes confinados salinos. Los cálculos de equilibrio se realizan usando valores de energía libre de Gibbs estimados teóricamente. En este artículo se presentan los siguientes diagramas de estabilidad:- Diagrama clinoptiloita-erionita-phillipsita.- Diagrama aoalcima-clinoptilolita-chabazita-eriooita-mordenita-phillipsita.- Diagrama feldespato potásico-zeolitas depósitos salinos.Los diagramas calculados ponen de manifiesto la influencia de las actividades de los iones alcalinos, alcalinotérreos, agua y sílice en el equilibrio entre las distintas zeolitas y entre estas y el feldespato potásico. Se estudia también la influencia del pH en la solubilidad de las zeolitas. Los resultados obtenidos demuestran que las zeolitas muy silícicas (clinoptilolita y mordenita son las más estables a pH inferiores a 10. Por el contrario, las zeolitas de bajo contenido en sílice (analcima y chabazita son las más estables a pH superiores a 10.

  6. Natural Mexican zeolite, potential material for hydrogen storage; Zeolita natural mexicana, material para su posible uso en el almacenamiento de hidrogeno

    Energy Technology Data Exchange (ETDEWEB)

    Iturbe-Garcia, J. L.; Lopez Munoz, B. E. [Instituto Nacional de Investigaciones Nucleares (Mexico)]. E-mail: joseluis.iturbe@inin.gob.mx

    2009-09-15

    This work presents a study of the use of natural Mexican zeolite as a possible alternative for hydrogen storage. This zeolite material is from the state of Sonora. Its particle size was decreased using a grinding treatment with a mechanical alloying system for 5 hours. The mechanical alloying equipment was built in our Institute (Instituto Nacional de Investigaciones Nucleares, ININ). Later, zeolite in powder form was characterized with x-ray diffraction and sweep electron microscopy. It was heated in a micro-reactor at 350 degrees Celsius, which was simultaneously emptied over 2 hours to eliminate humidity and possible gases trapped in its structure. Next, the temperature was reduce to 10 degrees Celsius and it was placed in contact with ultra-high pure hydrogen at a pressure of 10 bars for 10 minutes. The analysis of hydrogen trapped in the zeolite was conducted with gas chromatography. The results of the chromatograms indicate that the zeolite absorbed and liberated the hydrogen in completely different conditions than those reported in the literature. That is, with our experimental conditions at low pressure and temperature, the hydrogen was absorbed in this type of material. [Spanish] En este trabajo se presenta un estudio sobre el uso de una zeolita natural de origen mexicano como posible alternativa para almacenar hidrogeno. Este material zeolitico procede del Estado de Sonora, al cual se le disminuyo el tamano de particula mediante un tratamiento de molienda con un sistema de aleado mecanico durante 5 horas. El equipo de aleado mecanico se construyo en nuestro Instituto (Instituto Nacional de Investigaciones Nucleares, ININ). Posteriormente, la zeolita en forma de polvo se caracterizo por medio de difraccion de rayos X y microscopia electronica de barrido. Se sometio a calentamiento en un micro-reactor a 350 grados Celsios y al mismo tiempo haciendo vacio durante 2 horas, para eliminar humedad y posibles gases que estuvieran atrapados en su estructura. En

  7. Aumento de la producción de biogás mediante el uso de zeolita natural

    Directory of Open Access Journals (Sweden)

    Francisco Díaz Marrero

    2011-02-01

    Full Text Available El presente trabajo analiza la influencia de una zeolita natural sobre el proceso de digestión anaerobia, a partir de las evidencias existentes sobre el incremento de la degradación de la materia orgánica y la producción de biogás cuando se añaden a los digestores ciertos materiales en los que se incluyen compuestos arcillosos. Teniendo en cuenta estos antecedentes es objetivo del presente trabajo contribuir a la creación de un biocatalizadorque favorezca la producción de biogás a partir de materiales de relativo bajo costo. A partir de lo reseñado en la literatura sobre las características de absorción del amonio por la zeolita (Roque, 19871 y partiendo de la existencia en Cuba de importantes yacimientos de este mineral que tiene como base fundamental una estructura porosa de aluminio-silicato.Fueron estudiadas diferentes dosis de zeolitas para determinar su efecto sobre los procesos anaerobios adicionándoles a éstos nitrógeno en forma urea (H2N-CO-NH2, compuesto éste que en su hidrólisis produce amonio.  The presentA woPrk LanIalCyseAs thCe inIfOluenNce Eof Sa n aItNuraDl zeUolitSe onT thRe pIrAoceLss Eof aSnaerobic digestion, starting from the existent evidences on the increment of the degradation of theorganic matter and the biogas production when they are added to the material certain digesters in those that are included compound loamy. Keeping in mind these antecedents is objective of the present work to contribute to the creation of a biocatalizer that favours the biogas production starting from materials of relative low cost.Starting from that pointed out in the literature on the characteristics of adsorption of the ammonium for the zeolite (Roque, 1987 and leaving of the existence in Cuba of important locations of this mineral that has like fundamental base a porous structure of aluminumsilicate.Different zeolite doses were studied to determine its effect on the anaerobic processes adding these nitrogen in urea form

  8. Captación de amonio en zeolita al incubar gallinaza y residuos de codorniz

    Directory of Open Access Journals (Sweden)

    Sarai Guadalupe Valerio Luna

    2016-04-01

    Full Text Available Con la finalidad de conocer el efecto de la zeolita en la volatilización del dióxido de carbono (CO2 y amoniaco (NH3, se estableció un ensayo de incubación durante 20 días en condiciones controladas de humedad y temperatura, para lo cual se realizaron mezclas entre residuos orgánicos de aves y cantidades de zeolita utilizando un diseño factorial 24, teniendo un total de 8 tratamientos donde se evaluaron cada día las emisiones de CO2 y NH3. Los datos obtenidos fueron sometidos a un análisis de varianza y a una prueba de Tukey. Los resultados mostraron que la zeolita ayuda a la disminución de emisiones de NH3, y no afectó la actividad microbiana presente, se concluye que la zeolita atrapó el ion amonio en su estructura y no permitió su transformación a NH3.

  9. Estudio sobre la incorporación y retención de plomo en zeolita natural

    Directory of Open Access Journals (Sweden)

    Abraham Mendoza Córdoba

    2014-12-01

    Full Text Available Las zeolitas son un grupo de minerales que corresponden a la clase de los silicatos (tectosilicatos, entre las diversas utilidades que tienen estos minerales está la resolución de problemas ambientales, particularmente en la eliminación de contaminantes, entre estos se encuentran los metales pesados, los cuales están presentes en los suelos de zonas industriales, en el agua potable, en los afluentes de aguas procedentes de la industria y de la actividad minera, o bien procedentes de mantos acuíferos. Su utilidad se debe en parte por tener una gran capacidad de intercambio iónico, así como también por tener una estructura con cavidades de dimensiones nanométricas, eso le da la capacidad de incorporar elementos ajenos al mineral dentro de dichas cavidades. En el presente trabajo se ha experimentado con Pb incorporándolo en zeolitas (chabazita como acetato de plomo (Pb(CH3COO2 3H2O con el fin de conocer, por una parte, la capacidad del mineral para alojar dicho metal después de activarla, y por otra parte, conocer la capacidad de retención del metal después de un proceso reversible a la incorporación de Pb (activación.

  10. Eliminación del arsénico en diferentes clases de aguas con zeolitas naturales

    OpenAIRE

    Lazo Camposano, Roberto

    2013-01-01

    Para el desarrollo del presente trabajo de Investigación se ha tenido Ia referencia sobre todo de las contaminaciones de las diferentes aguas sea este de origen natural, aguas subterráneas, aguas de rio, aguas procedentes de Iluvias, aguas de filtraciones, aguas de minas, etc, es decir toda clase de agua que contenga el arsénico que es perjudicial a la salud humana. En el presente trabajo se utilizará un medio adsorbente que consiste de zeolita natural (clinoptilolita) recubierta con óxido...

  11. La zeolita y su efecto en la eficiencia del nitrógeno en arroz y maíz

    Directory of Open Access Journals (Sweden)

    Miguel Soca

    2014-12-01

    Full Text Available Este trabajo evaluó el efecto de la zeolita en las reducciones de volatilización del nitrógeno amoniacal (RVNA y volumen de lixiviados (RVL así como en rendimientos de arroz Oryza sativa L. y maíz Zea mays L. En el primer experimento bajo un Diseño Completamente al Azar (DCA se evaluó el tamaño de partícula de zeolita (< 1 mm, 1 - 2 mm, 2 - 3 mm y 3-5 mm en RVNA. El segundo experimento, consistió en evaluar RVL con la aplicación de cuatro tratamientos: testigo (T, zeolita (Z, urea (U y urea + zeolita (UZ. El tercer experimento se desarrolló en un cultivo de arroz, donde se evaluaron dos métodos de aplicación (al voleo y trasplante con cuatro tratamientos (T, U, UZ10% y UZ15% y su efecto en el rendimiento del cultivo. El cuarto experimento realizado en un campo de maíz con dos tratamientos (U y UZ15% evaluó el rendimiento del cultivo en dos suelos (aluvial y esquelético. Los tamaños de partícula entre 3 y 5 mm obtuvieron RVNA del 50% y RVL del 48%. La aplicación de zeolita en arroz obtuvo RVNA de 60% y mejoró los rendimientos sin encontrar diferencias entre método de aplicación. También su aplicación mejoró el peso de grano por mazorca y el peso seco de grano de maíz. La zeolita mejoró la eficiencia de la fertilización nitrogenada.

  12. Evaluación de la zeolita natural utilizada como una tecnología productiva y limpia, aplicada al pasto Maralfalfa (Pennisetum sp) como un complemento en el uso de los fertilizantes nitrogenados

    OpenAIRE

    Pérez-Marín, Manuel Francisco

    2014-01-01

    Proyecto de Graduación (Maestría en Gestión de Recursos Naturales y Tecnologías de Producción) Instituto Tecnológico de Costa Rica, Escuela de Ingeniería Agroforestal, 2014. La necesidad de buscar alternativas para el aprovechamiento de fertilizantes en pastos de alta calidad como Maralfalfa (Pennisetum sp), lleva a investigar a la zeolita a modo de tecnología complementaria al programa de fertilización. Países como México, Colombia, Ecuador y Bolivia han utilizado la zeolita de tal forma ...

  13. Metodología de los trabajos de campo para la prospección de zeolitas naturales

    OpenAIRE

    Costafreda Mustelier, Jorge Luis

    2011-01-01

    Los yacimientos de zeolitas naturales, como cualquier otro, están sujetos a normas de investigación que varían en dependencia de las necesidades del momento. En los últimos seis años, por citar un ejemplo, el estudio y la explotación de los recursos no metálicos en España, incluyendo las zeolitas naturales, ha experimentado un fuerte declive que ubica la demanda muy por debajo de las cifras conocidas antes del 2008, fecha en que se destapó la verdadera cara de la llamada “burbuja inmobiliaria...

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

    OpenAIRE

    COVARRUBIAS GALLARDO, CRISTIAN MAURICIO; COVARRUBIAS GALLARDO, CRISTIAN MAURICIO

    2005-01-01

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

  15. ESTUDIO DEL IMPACTO TÉCNICO DE MEZCLAS DE CONCRETO HIDRÁULICO POR LA SUSTITUCIÓN PARCIAL DE CEMENTO POR ZEOLITA

    Directory of Open Access Journals (Sweden)

    I. Miranda Pasos

    2014-06-01

    Full Text Available La industria de la construcción cada vez más consciente de la necesidad de ejecutar obras con materiales que se obtengan y/o utilicen procesos industriales que minimicen la contaminación y, que contribuyan en el comportamiento de un producto como lo es el concreto hidráulico en la construcción, ha estado buscando alternativas de materiales que sustituyan total o parcialmente al cemento por otro cementante que contamine menos en su procesos de obtención y que conserve las propiedades o las mejore. Una alternativa para sustitución parcial del cemento es la zeolita, es un mineral que se obtiene por proceso de excavación y molienda de puzolana. La norma ASTM-618, define a las puzolanas como materiales silíceo o aluminio-silíceo que por sí solo poseen poco a ningún valor cementante, pero cuando se han dividido finamente y en presencia de agua e hidróxido de calcio (Cal reaccionan químicamente a temperatura ambiente para formar cementantes (Miranda, 2008. Recientemente se ha estudiado el efecto de adicionar mineral Cal-Zeolita para la elaboración del concreto, cuyos resultados son favorables al comportamiento mecánico y su durabilidad (Dopico J.J., et al. 2009. Para la elaboración de morteros para recubrimientos al incorporar arenas zeolíticas como sustituto de la arena tradicional (Tiburcio et al. 2008. El presente proyecto evaluó el comportamiento del concreto hidráulico en estado fresco y endurecido al sustituir de manera parcial cemento por zeolita. Se enfocó a la evaluación del comportamiento mecánico como al diseño de la mezcla de concreto hidráulico fabricado con cemento normal y con cemento-zeolita. Tomando en cuenta los resultados obtenidos, la zeolita incorporada en porcentajes entre el 5% y 10 % tiende a valores de resistencias muy cercanos al concreto normal, los modelos obtenidos así lo corroboran, por lo que se puede concluir la factibilidad de sustitución parcial de cemento por zeolita tomando en cuenta el

  16. Ácidos silícicos como catalizadores y fuente de silicio/metal para zeolitas

    OpenAIRE

    Barea Berzosa, Eva María

    2011-01-01

    Barea Berzosa, EM. (2005). Ácidos silícicos como catalizadores y fuente de silicio/metal para zeolitas [Tesis doctoral no publicada]. Universitat Politècnica de València. doi:10.4995/Thesis/10251/1868.

  17. ISOMERIZACIÓN DEL 1-CICLOHEXILOCTANO EN ZEOLITAS H-ZSM-22 Y H-Y

    Directory of Open Access Journals (Sweden)

    Jorge Quintero

    2009-06-01

    Full Text Available En este trabajo presentamos los resultados de la evaluacion energetica de los intermediarios de la isomerización del 1-ciclohexiloctano en dos etapas. La primera etapa corresponde a la isomerización del 1-ciclohexiloctano en fase gaseosa vía carbocationes clásicos, usando el nivel de teoría DFT/B3LYP y conjunto de funciones base 6-31G.  En la segunda etapa se desarrolló la coordenada de reacción de la isomerización del 1-ciclohexiloctano en presencia de zeolitas ácidas H-ZSM-22 y H-Y empleando el método ONIOM, usando los niveles de teoría B3LYP/6-31G:UFF. Nuestros resultados muestran diferencias significativas entre las reacciones en fase gaseosa y condensada. Estas diferencias ponen de manifiesto la influencia del confinamiento cuántico que sufren las moléculas al interior de los sistemas microporosos del tipo zeolitas.

  18. Estimación de propiedades termodinámicas de silicatos. Construcción de diagramas de actividad de zeolitas

    Directory of Open Access Journals (Sweden)

    La Iglesia, A.

    1995-12-01

    Full Text Available In this paper we analyze the present methods of estimation of the thermodynamic properties of silicates with special emphasis on the free energy and enthalpy of zeolites. These data are not available in the literature, as these phases are chemically complexo The obtained values allow us to build the 10 following thermodynamic equilibrium diagrams: solubility of laumontite, chabazite, analcime, volcanic glass, zeolite A and zeolite X, and stability diagrams of chabazite-analcime-phillipsite-volcanic glass, clinoptilolite-phillipsite-erionite, prehnite-laumontite-heulandite, and kaolinite-metakaolinhidrosodalite-zeolite A. These diagrams can be useful to understand the genesis of these minerals and the processes that allow their formation in the laboratory.En este artículo se pasa revista a los métodos actuales de estimación de propiedades termodinámicas de silicatos, haciendo especial énfasis a los dedicados a la estimación de la energía libre de formación y de la entalpía de zeolitas, datos poco disponibles en la bibliografía debido a la complejidad química de estas fases. Los valores obtenidos han permitido construir los 10 diagramas de equilibrio termodinámico siguientes: diagramas de solubilidad de laumontita, chabazita, analcima, vidrio volcánico, zeolita A y zeolita X y los de estabilidad de chabazita-analcima-philipsitavidrio volcánico, clinoptilolita-philipsita-erionita, prehnita-laumontita-heulandita y caolinita-metacaolinita-hidrosodalita-zeolita A. Estos diagramas pueden explicar la génesis de los minerales o los procesos que dan lugar a su síntesis en el laboratorio.

  19. ESTUDIO SOBRE LA INFLUENCIA DE LA INCORPORACIÓN DE CATIÓN METÁLICO EN LA ACTIVIDAD CATALÍTICA Y COMPORTAMIENTO MAGNÉTICO DE ZEOLITAS ZSM-5

    Directory of Open Access Journals (Sweden)

    Clara Saux

    2011-01-01

    Full Text Available Se sintetizaron zeolitas ZSM-5 con relación molar Si/Al 17 por el método hidrotérmico, las que fueron modificadas con cobalto y cromo por la técnica de impregnación por vía húmeda en un 3 % p/p del metal. Los resultados obtenidos por DRX, indican que la incorporación de ambos metales de transición no altera la estructura, ni la cristalinidad de la matriz original. Se detecta la presencia de especies Co3O4 para Co-ZSM-5 y Cr2O3 para el caso de Cr-ZSM-5. De las medidas de magnetización a temperatura ambiente se observa el efecto de los metales de transición sobre el comportamiento netamente diamagnético de la matriz zeolítica con la aparición de ciclos de histéresis que no saturan por presentar una componente paramagnética. Ambos materiales fueron probados como catalizadores para la reacción de oxidación selectiva de estireno con peróxido de hidrógeno, presentando buenos resultados en actividad con una elevada selectividad (superior al 70 % hacia benzaldehído.

  20. ZEOLITAS EN LA FERTILIZACIÓN QUÍMICA DEL CACAO CCN-51 ASOCIADO CON CUATRO ESPECIES MADERABLES

    Directory of Open Access Journals (Sweden)

    Fernando David Sánchez Mora

    2014-05-01

    Full Text Available Se evaluó el efecto de dos zeolitas comerciales del tipo clinoptilolita: Roca Mágica® (RM y Zeolite C® (ZC, incluidas en la fertilización química sobre la producción y rentabilidad del cacao “CCN-51”, de origen sexual, asociado con cuatro especies maderables [Caoba de montaña (Colubrina arborescens (Mill. Sarg, fernánsanchez (Triplaris cumingiana F., guayacán blanco (Cybistax donell-smithii Rose y laurel prieto (Cordia macrantha Chadat]. En la fertilización fueron utilizados los dos tipos de zeolita (RM y ZC y dos niveles (25 y 30%, más un testigo (sin zeolita. La fertilización se fraccionó en tres partes aplicándose urea, MgSO4, K2O y P2O5. Se empleó un diseño de parcelas divididas con cuatro especies maderables, cinco subtratamientos (tipos y niveles de zeolita y un testigo, en cuatro repeticiones. Se utilizó la prueba de Tukey al 5% de probabilidad. Se midió la fenología del cacao (brotación, floración, fructificación, cherelles wilt, número de mazorcas sanas y producción de cacao en kg ha-1. El mayor número de brotes los emitieron las plantas de cacao asociadas con fernánsanchez en la época lluviosa, posiblemente por la menor cobertura aérea de esta especie. El cacao alcanzó su mayor fructificación en la época lluviosa con las asociaciones fernánsanchez y guayacán y, 30% de ZC. El mayor número de mazorcas sanas, y producción de cacao fue obtenido con la asociación fernánsanchez en la época seca. La mayor rentabilidad se encontró con fernánsanchez y 25% de RM.

  1. REMOCIÓN DE MICROORGANISMOS PATÓGENOS PRESENTES EN UN LICOR MIXTO BAJO CONDICIONES DE LABORATORIO EMPLEANDO FILTROS EMPACADOS EN ZEOLITA NATURAL REMOVAL OF PATHOGENIC MICROORGANISMS PRESENT IN MIXED LIQUOUR UNDER LABORATORY CONDITIONS BY USING FILTERS PACKED IN NATURAL ZEOLITE

    Directory of Open Access Journals (Sweden)

    Diana Rocío Acevedo Cifuentes

    2012-12-01

    Full Text Available En este artículo, se presentan los resultados obtenidos en la remoción de coliformes totales, coliformes fecales y salmonella-shigella, presentes en un licor mixto proveniente de la planta de tratamiento de aguas residuales San Fernando (Medellín, Colombia, mediante el uso de una batería de filtros empacados en zeolita clinoptilolita. La experimentación se desarrolló bajo condiciones controladas de caudal y pH, a temperatura ambiente. Se empleó zeolita natural tipo clinoptilolita la cual se activó con solución salina y secado, se empacó en una batería compuesta por dos filtros, uno de flujo descendente y otro de flujo ascendente, para facilitar el contacto de la solución contaminada y el material adsorbente (zeolita. Se realizaron cinco ensayos independientes y al final de cada uno de ellos se lavó y se activó el material zeolítico antes de comenzar el siguiente. En cada ensayo se tomaron tres muestras. Se encontró que la eficiencia de los filtros bajo las condiciones específicas de diseño fue significativamente alta en la remoción de los patógenos evaluados, y el porcentaje de remoción fue independiente del valor de la concentración a la entrada del filtro. Además, la eficiencia en la remoción de los patógenos evaluados no dependió del tipo de microorganismo.This article displays results obtained when total coliforms, fecal coliforms, and Salmonella shigella were removed from mixed liquor taken from San Fernando waste water treatment plant in Medellín, Colombia, by using a battery of filters packed in zeolite clinoptilolite. Experiments were developed under controlled conditions of flow and pH at room temperature. Natural clinoptilolite-type zeolite was used activated with saline solution and drying; it was packed in a battery consisting of two filters (a downward-flow filter and an upward-flow filter in order to make contact of contaminated solution and adsorbent material (zeolite easier. Five independent tests were

  2. MODIFICACIONES DE LAS PROPIEDADES TEXTURALES Y ESTRUCTURALES DE UNA ZEOLITA USY Y DE SUS MEZCLAS CON "CAOLÍN CLAY" Y CLORHIDROL COMO CONSECUENCIA DEL TRATAMIENTO HIDROTÉRMICO

    Directory of Open Access Journals (Sweden)

    Yazmin Yaneth Agamez Pertuz

    2008-03-01

    Full Text Available El catalizador de FCC está constituido por partículas de composición compleja donde el componente activo es una zeolita Y. En este trabajo se presentan los resultados texturales y estructurales de una zeolita USY comercial lixiviada, de una serie de catalizadores con 7, 15, 25, 35 y 45% de material activo y los de estos materiales desactivados hidrotérmicamente. Las muestras se caracterizaron por fluorescencia de rayos X (FRX, difracción de rayos X (DRX, resonancia magnética nuclear de silicio (29Si RMN y fisiadsorción de nitrógeno a 77 K. A partir de estos resultados se hallaron correlaciones entre el volumen de microporo y el contenido de zeolita y entre el grado de cristalinidad y el porcentaje de zeolita. Además, se encontró que un tratamiento con sólo 20% de vapor de agua a 1033 K durante 16 horas destruye los grupos estructurales Si(2Al y Si(3Al como reflejo de la dealuminización drástica que sufre el material. 

  3. Síntesis de Zeolitas del tipo ZSM y su utilización en la producción de Hidrocarburos aromáticos a partir de Metanol

    Directory of Open Access Journals (Sweden)

    Jorge Bonilla

    2009-10-01

    Full Text Available Se sintetizaron las zeolitas ZSM-5 H *, ZSM- 8H * y ZSM-11H * y se utilizaron como catalizadores en la conversión de metanol a hidrocarburos y agua. La zeolita ZSM-5 presentó los mejores rendimientos de conversión a productos de punto de ebullición similares a los de la gasolina y en su mayoría aromáticos.

  4. Ungüento ZZ, antiséptico elaborado con una zeolita natural modificada

    Directory of Open Access Journals (Sweden)

    Iliana Perdomo López

    1998-12-01

    Full Text Available Se realizó el diseño del ungüento ZZ a partir del producto activo zeolítico ZZ, el cual posee una marcada actividad antimicrobiana en el tratamiento de las micosis y afecciones bacterianas. Se elaboraron 3 formulaciones las cuales se evaluaron mediante determinaciones físico-químicas. La formulación I respondió a la utilización del ungüento hidrófilo como base, la II a la crema secante y la III a una base emulsionada aceite en agua. Se obtuvo como resultado la no utilización de las formulaciones I y II por la interacción del principio activo con el laurilsulfato de sodio y con el monoestearato de glicerilo, respectivamente. La formulación III resultó muy adecuada desde el punto de vista tecnológico y se le realizaron estudios toxicológicos de irritabilidad dérmica que resultaron favorables, ya que no hubo irritación de las zonas tratadas.ZZ oinment was designed from an active zeolite product which has a marked antimicrobial effect in the treatment of micosis and bacterial affections. Three different formulations were evaluated for the product through physicial-chemical determinations. Formulation I used hidrophil oinment as a base; formulation II used drying cream and Formulation III chose an oil-in-water emulsified base. As a result of this assessment, formulations I and II were not chosen because of the interaction of the active agent with sodium laurylsulphate and with glyceril monostereate respectively. Formulation III turned out to be the most suitable from the technological viewpoint. Toxicological studies were performed on this formulation to observe skin irritability but the results were favourable since there was no trace of irritation in the treated areas.

  5. Modelado de curvas de ruptura en la adsorción de agua sobre sílica gel y zeolita 4A

    Directory of Open Access Journals (Sweden)

    Andrés Rivera Guerrero

    2014-01-01

    Full Text Available Este artículo presenta el desarrollo de un modelo computacional para simular la adsorción de agua en un lecho empacado, comparando el desempeño de una zeolita 4A y una sílica gel tipo ‘A’. Se usó una variación de la isoterma de Langmuir para la zeolita 4A y la isoterma de Tóth para la sílica gel; se utilizó el modelo de fuerza motriz lineal (LDF para la velocidad de adsorción, con un coeficiente total dependiente de la temperatura. El modelo está constituido por cinco ecuaciones diferenciales parciales asociadas con las variables: fracción molar de agua, temperatura, presión, velocidad superficial y carga adsorbida de agua. Para resolver el sistema se empleó el método de líneas (MOL con el integrador ODE15S de Matlab ® . Se evaluaron como variables de respuesta el intervalo de tiempo característico de la curva de ruptura, la asimetría, la temperatura máxima y la caída de presión, mediante un esquema factorial de dos niveles. El tipo de adsorbente es la variable que más influencia tiene en las variables de respuesta. A la zeolita corresponde la mayor velocidad de adsorción, comportamiento que puede explicarse si se observa la forma de su isoterma de adsorción, aunque presenta una menor capacidad de retención de agua y mayor resistencia a la transferencia de masa.

  6. Cálculo por dinámica y mecánica molecular de sitios y calores de adsorción de Dipentenos sobre Zeolita Y

    Directory of Open Access Journals (Sweden)

    Cristian Blanco

    2011-06-01

    Full Text Available Hemos utilizado métodos de la mecánica molecular para estudiar la adsorción de R-limoneno, p-ment-1-eno, p-ment-8-eno y p-mentano sobre faujasita silícea y sobre zeolitas Y con relación Si/Al = 2 que contenían diferentes cationes en el sitio SII (Nal+, Fe2+, FeH y MnH. Los cálculos mostraron que la presencia de dobles enlaces en la molécula que se adsorbe y el tipo de catión en SIl determinan la estabilidad del complejo adsorbatozeolita. Las interacciones entre el huésped y la molécula adsorbida estuvieron dominadas por las contribuciones electrostáticas, las cuales aumentaron con la carga del catión en SII. La orientación de las moléculas insaturadas en la supercaja fue resultado del balance entre el aumento de repulsiones estéricas entre zeolita y molécula adsorbida y el aumento de atracciones electrostáticas como resultado de la minimización de dos grupos de distancias: las distancias entre el catión en SII y los carbonos Sp2 de la molécula adsorbida y las distancias entre los oxígenos estructurales de la zeolita y los hidrógenos de la molécula adsorbida.

  7. Fenoloxidasa Modificada: Clave para identificar cepas de Cryptococcus neoformans

    Directory of Open Access Journals (Sweden)

    Carlos Canelo D

    2000-01-01

    Full Text Available Cryptococcus neoformans es la única levadura patógena capaz de sintetizar pigmentos como la melanina mediante la actividad de su enzima llamada fenoloxidasa. El objetivo del presente estudio fue implementar y estandarizar la prueba de la fenoloxidasa, como técnica complementaria en la identificación de cepas de C. neoformans. Se estudiaron 21 cepas, identificadas previamente con métodos convencionales. La prueba de la fenoloxidasa fue modificada debido a que su empleo originaba 9,6% (2/21 de falsa negatividad. Esta prueba modificada se optimizó a 28°C a partir de un medio con baja concentración de glucosa. Ningún aislamiento falso negativo fue encontrado luego de repetir tres veces el ensayo, y el pigmento melanina fue detectado con mayor rapidez.

  8. Armazenamento de abacaxi 'smooth cayenne' minimamente processado sob refrigeração e atmosfera modificada

    Directory of Open Access Journals (Sweden)

    Prado Mônica Elisabeth Torres

    2003-01-01

    Full Text Available Estudou-se a influência de diferentes atmosferas modificadas durante o armazenamento de abacaxis da cv. Smooth Cayenne minimamente processados, por um período de oito dias, a 5º C e 85% UR. Foram realizadas as análises de acidez total titulável (ATT, sólidos solúveis totais (SST, pH, líquido drenado (LD, pectina total (PT, pectina solúvel (PS, firmeza e determinou-se a atividade das enzimas polifenoloxidase (PFO e poligalacturonase (PG da polpa dos frutos, a cada 2 dias. Os tratamentos utilizados foram: atmosferas modificadas com a injeção de 5% de O2 e 5% de CO2, com 2% de O2 e 10% de CO2 e o Controle (atmosfera modificada passivamente. As atmosferas modificadas ativas apresentaram ação injuriosa sobre os tecidos do abacaxi minimamente processado, estimulando a atividade da PFO. O uso de atmosferas modificadas proporcionou menor atividade da PG e, conseqüentemente, menor solubilização de substâncias pécticas. O abacaxi cv. Smooth Cayenne, minimamente processado, apresentou uma vida útil de 6 dias, pois, embora suas principais características físicas e físico-químicas não tenham sido comprometidas, as alterações químicas e bioquímicas não permitiram que o produto atingisse os 8 dias de armazenamento previstos.

  9. Zeolites of the Valle Central of Costa Rica and its outskirts; Zeolitas del Valle Central de Costa Rica y sus alrededores

    Energy Technology Data Exchange (ETDEWEB)

    Zeledon, Luis Alonso [Moravia, San Jose, (Costa Rica)

    2004-12-15

    19 different species of zeolites have been found in 25 outcrops in the Valle Central of Costa Rica and in the Siquirres region. All the zeolites are secondary minerals and crystallized in little veins and vesicles of the basalts and pyroclastics rocks of the La Cruz and Grifo Alto formations, belonging to the Aguacate Group and the alkaline igneous rocks of Guayacan. The most frequent species of zeolites are stibnite, chabasite, laumontite, mesolite/mordenite, thomsonite, and analcime. Natrolite only was found near to Siquirres. (Author) [Spanish] Se describen 19 especies diferentes de zeolitas procedentes de 25 afloramientos en los alrededores del Valle Central de Costa Rica y en la region de Siquirres. Todas las zeolitas descritas son de origen secundario y se presentan en vetillas y vesiculas de los basaltos y rocas piroclasticas de las formaciones La Cruz y Grifo Alto del Grupo Aguacate y en las rocas igneas alcalinas de Guayacan. Las especies mas frecuentes son estilbita, chabasita, laumontita, mesolita/modernita, thomsonita y analcima. La natrolita solo se encontro en los alrededores de Siquirres. (Autor)

  10. Simulación físico-matemática del secado de la zeolita con microondas. // Physical-mathematical simulation of the zeolite drying with microwaves.

    Directory of Open Access Journals (Sweden)

    G. Quesada Ramos

    2004-01-01

    Full Text Available Se realiza una simulación físico-matemática del secado de la zeolita sometida a radiaciones de microondas utilizando la leyde Lambert. Las ecuaciones se expresan en un esquema implícito unidimensional, y se emplea el método numérico dediferencias finitas. La solución del sistema de ecuaciones se realiza por medio del método iterativo de Gauss-Seidel. Losresultados teóricos se comparan con los obtenidos experimentalmente.Palabras claves: Simulación, secado, zeolita, microondas._______________________________________________________________________________AbstractA physical-mathematical simulation of the zeolite drying with microwaves using the Lambert`s law is made. The equationsare expressed in an unidimensional implicit scheme, and the finite differences numeric method is used. The solution of theequations system is carried out by using the Gauss-Seidel´s iterativ method. The theoretical results are compared with thoseexperimentally obtained.Key words: Physical-mathematical simulation, drying, zeolite, microwaves.

  11. Empaque de alimentos en atmosferas modificadas

    OpenAIRE

    Restrepo Molina, Diego Alonso

    2003-01-01

    Resumen: Las técnicas usadas para reducir el oxígeno alrededor del alimento son conocidas como Modified Atmosphere Packaging (MAP) e incluyen el empacado en atmosfera controlada y el “verdadero” empacado en atmosfera modificada. Teniendo en cuenta que la refrigeración es considerada, en el ámbito de los alimentos, como uno de los métodos de conservación de mayor impacto, ya que retarda el deterioro de los alimentos almacenados por periodos importantes de tiempo, la combinación de la disminuci...

  12. Función ventilatoria en obreros expuestos al polvo de zeolita

    Directory of Open Access Journals (Sweden)

    Guillermo López Espinosa

    2000-08-01

    Full Text Available El presente estudio descriptivo y prospectivo se realizó en la Mina-Planta Zeolita Tasajeras, ubicada en el municipio de Ranchuelo, provincia de Villa Clara, desde septiembre del año 1998 a 1999 con el objetivo de evaluar la función ventilatoria en un grupo de obreros expuestos al polvo del mineral. A los 37 trabajadores que llevan 2 o más años de labor en el centro se les aplicó un cuestionario y se efectuaron 2 estudios espirométricos con un intervalo de 1 año. La información se analizó y los resultados fueron: de los 16 pa-cientes con prueba funcional ventilatoria patológica en el año 1998 se extendió a 24 en el 1999. El 64,8 % con afectación espirométrica mantiene entre 6 a 10 años de exposición al polvo del mineral zeolita y el 58,3 % son fumadores. El patrón espirográfico que predominó fue el obstructivo (56,8 % y se aprecia en el 62,1 % de los estudiados una disminución del flujo espiratorio forzado al 25 % (Vmax 25/H/L/TThe present descriptive and prospective study was conducted in "Tasajeras" Zeolite Mine-Plant, located in the municipality of Ranchuelo, province of Villa Clara, from September, 1998, to September, 1999, aimed at evaluating the ventilatory function in a group of workers exposed to zeolite dust. 37 workers with 2 or more years in the center answered a questionnarie. 2 sperimotric studies were carried out with a one-year interval. The information was analyzed and the results were the following: the number of patients undergoing the pathological ventilatory functional test was increased from 16, in 1998, to 24, in 1999. 64.8% of those with spirometric affectation have been exposed between 6 and 10 years to zeolite dust and 58.3% are smokers. The obstructive spirographic pattern prevailed (56.8%. A reduction of the forced expiratory flow to 25% (Vmax 25/H/L/T was observed in 62.1% of the studied individuals

  13. BIOADSORCIÓN DE ARSÉNICO (III EN SOLUCIÓN ACUOSA POR LA BIOMASA MODIFICADA DE Aspergillus niger

    Directory of Open Access Journals (Sweden)

    Erik E. Santos

    2017-01-01

    Full Text Available Se analizó la capacidad de remoción de As (III en solución acuosa por la biomasa modificada de Aspergillus niger, mediante Espectrometría de Absorción Atómica. La mayor bioadsorción (66% con 1 mg/L del metaloide fue a las 24 horas, a pH de 6.0, 28oC y 1 g de biomasa modificada. Con respecto a la temperatura, la más alta remoción fue a los 28oC, con un 66% de remoción a las 24 horas. A las concentraciones de As (III analizadas, la biomasa mostró una buena capacidad de remoción. Al aumentar la concentración del bioadsorbente, la remoción es más eficiente (91.2% con 5 g de biomasa, además de remover eficientemente el metaloide (67% de remoción en agua natural contaminada con 1 mg/100 mL de As (III a las 24 horas con 5 g de biomasa, por lo que puede ser utilizado para eliminar aguas residuales industriales.

  14. Utilización de la zeolita para disminuir los gases tóxicos de los motores de combustión interna. // The utilization of Cuban zeolites in the decrease of toxic gases emissions of internal combustion engines.

    Directory of Open Access Journals (Sweden)

    J. L. Reyes González

    2003-01-01

    Full Text Available En el trabajo se presentan los resultados obtenidos al utilizar la zeolita natural cubana para la disminución de los gasestóxicos que los motores de combustión interna MCI. envían a la atmósfera. Los experimentos fueron realizados en bancosde pruebas de MCI. tanto para motores de carburación como para motores diesel. Obteniéndose eficiencias de disminucióndel CO del 80 %, del CnHm del 50% y el humo negro en un 90%. Se demuestra la importancia de la granulometría de lazeolita para esta eliminación y para mantener la potencia del motor dentro de rangos aceptables.Palabras claves: Toxicidad, zeolita, medio ambiente, filtros, gases de escape._______________________________________________________________________________Abstract.In this paper are presented the results of the utilization of Cuban zeolites in the decrease of toxic gas emissions toatmosphere of internal combustion engines, (MCI. The experiments were carried out in test bank for gasoline and dieselengines. The efficiency in the decrement of CO was of 80%, CnHm in 50%, and 90 % in soot. The size of the zeolitesparticle importance in the efficiency is demonstrated.Key words: Toxicity, zeolite, enviroment, filters, gas emissions.

  15. Célula del SMF modificada genéticamente para sobreexpresar NGAL y su uso como medicamento

    OpenAIRE

    Hotter, Georgina; Jung, Michaela; Solà, Anna M.

    2009-01-01

    Célula del SMF modificada genéticamente para sobreexpresar NGAL y su uso como medicamento. La presente invención se encuadra dentro del campo de la biomedicina. Específicamente, la presente invención se refiere a una célula del Sistema Mononuclear Fagocítico o SMF, preferiblemente un monocito o un macrófago, modificada genéticamente para sobreexpresar la lipocalina asociada a gelatinasa de neutrófilos (NGAL, en sus siglas en inglés), a un método para su obtención y a s...

  16. Síntesis de zeolita LTA sobre soportes de corindón: Evaluación preliminar para la eliminación de metales pesados de efluentes acuosos

    Directory of Open Access Journals (Sweden)

    Jacas, A.

    2012-10-01

    Full Text Available The effectiveness of materials based on LTA Zeolite as active phase, for their incorporation into systems aimed at the removal of heavy metals on waste water is evaluated in a preliminary way. This type of Zeolite with the main channel of a minimum free diameter of 0,41 nm and a low SiO2/Al2O3 ratio is an interesting molecular sieve, which in turn display a high ion exchange capacity. From this point of view, LTA Zeolite crystals were obtained “in situ” by hydrothermal synthesis and characterized by x ray diffraction (XRD and scanning electron microscopy (SEM. We have studied the effect of hydrothermal synthesis time at 378 K. Likewise, the removal capacity of heavy metal from the active phase was evaluated in as a first step on diluted solutions of cooper salts at slightly acidic pH (~ 4,7.

    En este trabajo se evalúa de forma preliminar la efectividad del empleo de materiales basados en zeolita LTA, como fase activa para su incorporación en sistemas orientados a la eliminación de metales pesados presentes en aguas residuales. Este tipo de zeolitas con el canal principal de un diámetro mínimo libre de 0,41 nm y una baja relación SiO2/Al2O3 se presenta como un tamiz molecular interesante, que a su vez manifiesta una gran capacidad de intercambio iónico. Partiendo de este punto de vista, cristales de zeolita LTA fueron obtenidos “in situ” por síntesis hidrotermal y caracterizados por difracción de rayos X (DRX, y microscopia electrónica de barrido (MEB. Se ha estudiado el efecto del tiempo de tratamiento hidrotermal a 378 K. Asimismo, la capacidad de eliminación de metales pesados de la fase activa de los sistemas obtenidos fue evaluada en una primera etapa en soluciones diluidas de sales de cobre a pH ácido (~ 4,7.

  17. Transformações bioquímicas de abacaxi minimamente processado armazenado sob atmosfera modificada Biochemical modifications of pineapple minimally processed under modified atmosphere

    Directory of Open Access Journals (Sweden)

    Mônica Elisabeth Torres Prado

    2004-12-01

    Full Text Available Realizou-se estudo sobre a influência da atmosfera modificada com diferentes concentrações de gases durante o armazenamento de abacaxi cv. Smooth cayennne minimamente processado, por oito dias, à temperatura de 5ºC e 85% de UR. Foram realizadas análises de açúcares neutros, celulose, hemicelulose e poliuronídeos totais na parede celular. O abacaxi minimamente processado foi acondicionado sob duas Atmosferas Modificadas Ativas, uma com 5% de O2 e 5% de CO2 (AM1,outra com 2% de O2 e 10% de CO2 (AM2,e uma Atmosfera Modificada Passiva (Controle durante 8 dias de armazenamento. O uso de atmosferas modificadas ativas permitiu que o abacaxi minimamente processado sofresse menor degradação da parede celular com menor solubilização das hemiceluloses. Abacaxis minimamente processados e armazenados sob atmosfera modificada obtiveram uma vida de prateleira média de 6 dias, a 5º C.Pineapples minimally processed were, stored eight days (5ºC and 85% RH under passive and active atmosphere (MA. Neutral sugars, cellulose, hemicellulose, and total polyuronide analysis in cell wall were done. Two different active MA were tested: 5% of O2 + 5% of CO2 (MA1 and 2% of O2 + 10% of CO2 (MA2 and one passive MA (Control; during eight days of storage. Pineapples minimally processed stored under active modified atmosphere showed degradation of cell wall and less solubilization of hemicelluloses, besides being more effective in control of ethanol production and formation of off flavours. Pineapples minimally processed stored under modified atmosphere, showed life average of 6 days under refrigeration at 5ºC.

  18. Evaluación de las Propiedades Mecánicas de una Mezcla Densa en Caliente Modificada con un Desecho de PVC

    Directory of Open Access Journals (Sweden)

    Hugo A. Rondón-Quintana

    2011-12-01

    Full Text Available El presente trabajo evaluó en laboratorio, la resistencia mecánica bajo carga monotónica, el módulo resiliente y la resistencia a la deformación permanente que experimenta una mezcla asfáltica cuando se modifica con un desecho de policloruro de vinilo (PVC por vía húmeda. Adicionalmente, fue evaluada durante 21 meses, la influencia del medio ambiente de la ciudad de Bogotá D.C. sobre las propiedades mecánicas de la mezcla modificada. De los resultados obtenidos se concluye que la resistencia mecánica de la mezcla asfáltica modificada es superior en comparación con la convencional. La tendencia general de las mezclas con el tiempo de exposición al medio ambiente de Bogotá D.C. es experimentar un aumento en los valores de rigidez debido principalmente a procesos de endurecimiento por envejecimiento del ligante asfáltico. Sin embargo, para el caso de las mezclas fabricadas con CA 60-70 y modificadas con PVC en los primeros 15 meses de exposición, la rigidez disminuye por efecto de micro-fisuración térmica.

  19. 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

  20. Almacenamiento refrigerado de cerezas : efecto de madurez y atmósfera modificada

    OpenAIRE

    Yommi, Alejandra; Godoy, Carlos; Horvitz, Sandra; López Camelo, Andrés

    2002-01-01

    Se estudió el efecto de cosechar cerezas en dos estados de madurez: rojo pálido y rojo maduro y la utilización de atmósferas modificadas, empleando PBD de 11 y 40 m, sobre la calidad de fruta almacenada a 0 °C y después de 3 días a temperatura ambiente. La calidad fue evaluada en términos de pérdida de peso (%), color (ángulo hue), firmeza, contenido de sólidos solubles, aspecto de los pedicelos y presen...

  1. Revisão: alimentos frescos minimamente processados embalados em atmosfera modificada Review: fresh, minimally processed foods packaged under modified atmosphere

    Directory of Open Access Journals (Sweden)

    Joana Silva Santos

    2012-03-01

    Full Text Available Os alimentos frescos, minimamente processados e embalados sob atmosfera modificada atraem os consumidores que procuram produtos frescos e saudáveis, e que, ao mesmo tempo, são fáceis de transportar e preparar. A atmosfera no interior das embalagens consiste numa mistura de gases que está otimizada para cada alimento, de modo a preservar as suas qualidades durante mais tempo. A manutenção da temperatura de refrigeração durante o processamento, o armazenamento, a distribuição e a comercialização é essencial, por causa da natureza perecível dos produtos frescos minimamente processados. Este trabalho discute o estado de arte dos alimentos frescos minimamente processados (frutas, vegetais, carnes e pescados embalados em atmosfera modificada, com uma descrição pormenorizada dos últimos desenvolvimentos nesse campo.Fresh, minimally processed foods packaged under modified atmospheres are attractive to consumers searching for fresh healthy products that are also easy to transport and prepare. The atmosphere inside the package is a blend of gases optimized for each type of food, such that the quality characteristics are preserved for longer. However, due to the perishable nature of minimally processed fresh foods, maintenance at refrigeration temperatures is essential during processing, storage, distribution and commercialization. This paper discusses the state of art of minimally processed fresh foods (fruit and vegetables, meat and fish packaged under modified atmosphere, with a detailed description of the latest developments in this field.

  2. Nivel del PH salival en niños de 6 meses a 18 meses de edad con ingesta de leche evaporada modificada y leche materna

    OpenAIRE

    Flores Concha, Paulita

    2010-01-01

    RESUMEN Objetivo: Determinar el nivel del pH salival en niños de 6 meses a 18 meses de edad con ingesta de leche evaporada modificada y leche materna, en el Programa Nacional Wawa Wasi del distrito de Villa María del Triunfo, según el tiempo transcurrido. Material y método: La muestra estuvo conformada por 40 niños de 6 meses a 18 meses de edad, distribuidos en dos grupos: 20 que consumieron leche materna y 20 que ingirieron leche evaporada modificada. Se les dio a tomar la leche ...

  3. Structural simulation of natural zeolites; Simulacion estructural de zeolitas naturales

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-07-01

    The application of X-ray diffraction (XRD) in the study of crystalline structures of the natural and modified zeolites allows the identification, lattice parameter determination and the crystallinity grade of the sample of interest. Until two decades ago, simulation methods of X-ray diffraction patterns were developed with which was possible to do reliable determinations of their crystalline structure. In this work it is presented the first stage of the crystalline structure simulation of zeolitic material from Etla, Oaxaca which has been studied for using it in the steam production industry and purification of industrial water. So that the natural material was modified for increasing its sodium contents and this material in its turn was put in contact with aqueous solutions of Na, Mg and Ca carbonates. All the simulations were done with the Lazy-Pulverix method. The considered phase was clinoptilolite. It was done the comparison with three clinoptilolite reported in the literature. (Author)

  4. Evaluación de las propiedades mecánicas de una mezcla densa en caliente modificada con asfaltita/Mechanical Properties Evaluation of a hot Asphalt Mixture Modified with Asphaltite

    Directory of Open Access Journals (Sweden)

    Hugo Alexander Rondón Quintana

    2012-12-01

    Full Text Available El trabajo evaluó en laboratorio la resistencia mecánica bajo carga monotónica, el módulo resiliente y la resistencia a la deformación permanente que experimenta una mezcla asfáltica cuando se modifica con una asfaltita. Adicionalmente, fue evaluada durante dos años, la influencia del medio ambiente de la ciudad de Bogotá D.C., sobre las propiedades mecánicas de la mezcla modificada. Se concluye que la resistencia mecánica de la mezcla asfáltica modificada incrementa en comparación con la convencional. La tendencia general de las mezclas con el tiempo de exposición al medio ambiente de Bogotá D.C., es experimentar un aumento en los valores de rigidez debido principalmente a procesos de endurecimiento por envejecimiento del ligante asfáltico. Sin embargo, para el caso de las mezclas modificadas y fabricadas con CA 60-70 en los primeros cinco meses de exposición, la rigidez disminuye.The strength under monotonic load, resilient modulus and rutting were evaluated on a hot-mix asphalt (HMAmodified with a natural sphaltite. Additionally, the influence of the environmental conditions of BogotáD.C., was evaluated during two years on the mechanical properties of a modified asphalt mixture. The results show that the mechanical properties evaluated were better for the HMA mixes modified in compared with those with neat asphalts. The asphaltite produces higher mechanical resistance in HMA. The general tendency of the mixtures is increase the modulus with time due to aging of the asphalt cement. However, modified mixtures with AC 60- 70, decrease in stiffness during the first months.

  5. Evaluación de bolsa atmósfera modificada y concentraciones de anhídrido sulfuroso aplicadas sobre frutos de arándano alto (Vaccinium corymbosum L. cv. Emerald

    Directory of Open Access Journals (Sweden)

    Mario Rodríguez Beraud

    2015-01-01

    Full Text Available Con el objetivo de evaluar las técnicas de atmósfera modificada y aplicación de anhídrido sulfuroso sobre parámetros de calidad de postcosecha en frutos de arándanos (Vaccinium corymbosum L. cv. Emerald, se realizó un experimento de seis tratamientos, dados por la combinación de dos factores, atmósfera modificada (con y sin, y diferentes concentraciones de anhídrido sulfuroso (generadas por 0, 1 y 2 g de metabisulfito de sodio durante 7, 14, 21 y 28 días a 0 °C. Con la dosis de 2 g de metabisulfito de sodio en atmósfera modificada no se presentaron pudriciones, a diferencia del tratamiento testigo que presentó un 4,86% luego de 28 días de almacenaje. Los resultados indican que la incidencia de pudrición gris disminuyó significativamente (p ≤ 0,05 con anhídrido sulfuroso en bolsa atmósfera modificada, existiendo un efecto de interacción entre ambos factores, no obstante, el gas causó daños de blanqueamiento de frutos, el que correspondió a un 11,66% con una dosis de 2 g de metabisulfito de sodio, luego de 28 días de almacenaje. El uso de bolsa de atmósfera modificada redujo significativamente (p ≤ 0,05 la pérdida de peso por deshidratación (en promedio un 4% respecto a los tratamientos donde esta tecnología no fue utilizada. La concentración de sólidos solubles no fue influenciada por los tratamientos, manteniéndose entre 13 y 14%.

  6. ARCILLA BENTONÍTICA MODIFICADA CON QUITOSANO PARA MATERIALES COMPUESTOS BIODEGRADABLES

    Directory of Open Access Journals (Sweden)

    GUSTAVO NEIRA ARENAS

    2011-01-01

    Full Text Available Se estudió la modificación de una arcilla colombiana tipo montmorillonita con un biopolímero policatiónico -quitosano-, y se evaluó el efecto del peso molecular del modificante en la efectividad del tratamiento de modificación. Como material de partida se empleó una arcilla montmorillonítica sódica la cual se sometió a un procedimiento de modificación desarrollado para tal fin, empleando diferentes concentraciones de quitosano de bajo y alto peso molecular. Las muestras de arcilla modificada fueron analizadas mediante Difracción de Rayos X, Espectroscopía de Infrarrojo con Transformada de Fourier (FTIR, y Análisis Termogravimétrico (TGA con el fin de identificar los posibles efectos del tratamiento de modificación sobre la estructura de la arcilla. Los resultados mostraron una relación directa entre el incremento de la distancia interlaminar de la arcilla modifi cada y la concentración de quitosano, encontrándose un incremento máximo de 1,559 nm para la relación 2:1 en peso de quitosano de bajo peso molecular y arcilla. En general, se detectó una mayor separación interlaminar en la arcilla al emplear quitosano de bajo peso molecular como modificador, comparado con el quitosano de alto peso molecular, aunque en los dos casos se observó una integración efectiva del agente modificador a la estructura de la arcilla. El análisis IR de la arcilla modificada evidenció la presencia en la estructura de grupos CH, NH3+, CH y NH , provenientes del quitosano, mientras el análisis TG sugirió un cierto grado de hidrofobicidad asociada a la presencia de quitosano, siendo estos aspectos de gran importancia para la aplicación de estos materiales como refuerzos de películas poliméricas biodegradables.

  7. Estudio del comportamiento agronómico de las zeolitas en la fertilización del cultivo de la sandía (citrullus vulgaris) en la zona de taura, Guayas

    OpenAIRE

    Idrovo, Jorge; Quilambaqui, Miguel

    2009-01-01

    Con el fin de evaluar el comportamiento y efecto de las zeolitas en la producción del cultivo de la sandía, se realizó un estudio agronómico en la zona de Taura, Guayas, Ecuador, donde se instaló un ensayo de campo, en un área experimental de 3300 m2. El diseño que se aplicó en este estudio fue de un Bloques Completos al Azar (DBCA), conformado por 7 tratamientos y 4 repeticiones, con un total de 28 unidades experimentales. Los tratamientos a evaluarse, fueron dosis total de fertilizantes con...

  8. Vida-de-prateleira de goiabas minimamente processadas acondicionadas em embalagens sob atmosfera modificada

    Directory of Open Access Journals (Sweden)

    Pereira Leila Mendes

    2003-01-01

    Full Text Available Goiabas (Psidium guajava L., variedade vermelha "Paluma", minimamente processadas por desidratação osmótica branda, foram acondicionadas em embalagens rígidas de polietileno tereftalato (PET e estocadas à temperatura de 5masculineC, com o objetivo de avaliar a influência da embalagem sob atmosfera modificada e do processo de desidratação osmótica na vida-de-prateleira do produto. Goiabas sem o tratamento osmótico, acondicionadas nas embalagens de PET e em ar atmosférico, foram utilizadas como controle. Durante a estocagem foram avaliadas a perda de peso, a contaminação microbiológica, as características físico-químicas do produto e as concentrações de O2 e CO2 no interior das embalagens. As goiabas foram submetidas também a uma análise sensorial de aceitação, acompanhada da avaliação da intenção de compra do produto pelo consumidor. Verificou-se que a combinação da temperatura de estocagem, da embalagem sob atmosfera modificada passiva e do processo de desidratação osmótica proporcionou às goiabas minimamente processadas uma vida-de-prateleira de 24 dias, resultando num produto mais estável à contaminação microbiológica e com características sensoriais superiores às amostras controle, apresentando, também, melhor aceitação pelo consumidor.

  9. Avaliação da qualidade do abacaxi "Pérola" minimamente processado armazenado sob atmosfera modificada Evaluation of quality in fresh-cut 'Pérola' pineapple stored under modified atmosphere

    Directory of Open Access Journals (Sweden)

    Juliana Costa Bueno Santos

    2005-04-01

    Full Text Available Objetivou-se com este trabalho verificar o efeito da atmosfera modificada ativa sobre a qualidade do abacaxi minimamente processado. Assim, foram avaliadas as modificações físico-químicas, sensorial e microbiológica do abacaxi 'Pérola' minimamente processado submetido a diferentes atmosferas modificadas passiva e ativamente (controle - atmosfera modificada passiva; 5%O2 + 5%CO2 , 2%O2 + 10%CO2. A atmosfera com 2% O2 + 10% CO2 determinou menor perda de líquido drenado, embora tal perda tenha sido desprezível. A atmosfera modificada ativa preveniu o amaciamento do abacaxi minimamente processado, reduzindo a atividade da poligalacturonase e solubilização péctica. As variáveis pH e vitamina C não foram significativamente afetadas pela atmosfera modificada ativa. Maiores valores de sólidos solúveis totais (SST foram encontrados nos frutos sob atmosfera 5% O2 + 5% CO2 e no caso dos açúcares solúveis o tratamento com 2% O2 + 10% CO2 resultou em maiores teores. De acordo com análise sensorial, os frutos sob atmosfera modificada passiva se sobressaíram com relação ao sabor, aparência e cor. A análise microbiológica detectou valores insignificantes para fungos filamentosos, leveduras e coliformes a 35° e 45°C em todos os tratamentos. Conclui-se que o abacaxi 'Pérola' minimamente processado pode ser armazenado por 8 dias, a 5°C, sob atmosfera modificada passiva.The goal of this work was to verify the effect of active modified atmosphere on the quality of fresh-cut pineapple. Physical-chemical, sensory and microbiological changes of fresh-cut 'Pérola' pineapple treated with passive (control and active (5%O2 + 5%CO2; 2%O2 + 10%CO2 modified atmosphere were studied. The 2%O2 + 10%CO2 combination promoted the lowest loss of drained liquid, although they were negligible. Active modified atmosphere prevented the softening of fresh cut pineapples, reducing the poligalacturonase activity and pectin solubilization. The pH and ascorbic

  10. Determinación de parámetros físicos aplicables en el escalamiento de la síntesis de zeolita NaA, a partir de geles aluminosilicatos

    OpenAIRE

    Carmen M. López; Adriana García; Miguel Ríos; Neyla Rondón; Luis García; Johliny Casanova; Kevin Contreras

    2016-01-01

    Se estudió el efecto de parámetros físicos que influyen en la preparación de la zeolita NaA, a fin de determinar condiciones favorables para realizar el escalamiento de esta síntesis. Partiendo de una mezcla de síntesis con composición fija y cristalización a 80 °C se estudiaron los siguientes parámetros: orden y velocidad de agregado de las soluciones de partida, velocidad y tiempo de agitación de la mezcla de síntesis, agitación durante la cristalización, tiempo de cristalización y reciclo ...

  11. Estudio teórico de formas inusuales y modificadas de los ácidos nucleicos

    OpenAIRE

    Faustino Pló, Ignacio

    2013-01-01

    1) Estudio teórico de nucleobases modificadas. Las modificaciones químicas de ácidos nucleicos tienen una amplia variedad de aplicaciones tanto en clínica, utilizadas como agentes antisentido, así como en el estudio de las estructuras de los propios ácidos nucleicos, las interacciones proteína DNA o en la catálisis de ácidos nucleicos por poner algunos ejemplos. Actualmente se sintetizan cientos de análogos de nucleósidos estándar en laboratorios farmacéuticos, algunos de ellos como, ...

  12. “Aplicaciones farmacéuticas de los materiales zeolíticos"

    OpenAIRE

    Regragui, Salwa

    2016-01-01

    Las zeolitas son aluminosilicatos de estructura cristalina y microporosa. Pueden ser de origen natural u obtenido por síntesis química en el laboratorio. Incorporan en su estructura tridimensional moléculas de agua y cationes que ocupan los microporos. Estas características les confieren muchas ventajas como un gran poder de adsorción y una importante capacidad de intercambio catiónico. Además, la presencia de microporos de tamaño variable dependiendo del tipo de zeolita permite su uso como t...

  13. Novos sensores quimicos preparados com silica gel modificada com o ion piridinio

    OpenAIRE

    Lilian de Lourdes Lorencetti Prado

    1995-01-01

    Resumo: A sílica gel, com área superficial específica de 500 m.g e diâmetro médio de poros de 6 nm, foi organofuncionalizada com o íon piridínio. Reagiu-se a sílica com 3-cloropropiltrimetoxisilano e piridina, usando como solvente o CCI4. A quantidade de íons cloreto disponíveis para reações de troca iônica foi de 0,36 mmol.g. O espectro na região de infravermelho da sílica modificada (daqui para frente designada como SiPyCI) confirmou a presença dos grupos funcionais na superfície da mesma, ...

  14. Evaluación de la eficiencia de una batería de filtros empacados en zeolita en la remoción de metales pesados presentes en un licor mixto bajo condiciones de laboratorio

    OpenAIRE

    Acevedo Cifuentes, Diana Rocío; Builes Felizzola, Sandra Milena; Ordóñez Ante, Carlos Andrés; López Sánchez, Idalia Jacqueline

    2011-01-01

    En este artículo se muestran resultados de investigación obtenidos en la remoción de los metales pesados, plomo, níquel, cromo, cadmio y mercurio, presentes en una solución compuesta por licor mixto proveniente de la planta de tratamiento de aguas residuales de San Fernando y una solución preparada con metales pesados con una concentración conocida, mediante el uso de una batería de filtros empacados en zeolita clinoptilolita. La experimentación se desarrolló bajo condiciones controladas de c...

  15. Tratamiento quirúrgico de la pancreatitis aguda con técnica de Puestow modificada

    OpenAIRE

    Vázquez Merayo, Enrique; Moreno Pissau, Francisco; Labrada Arjona, Eduardo; Vázquez Martínez, Yovany Enrique

    2014-01-01

    La pancreatitis crónica representa uno de los mayores desafíos de la Gastroenterología, y su etiología sigue siendo difícil de establecer en 10-30 % de los pacientes. Se presenta un paciente masculino, de 13 años, con diagnóstico de pancreatitis crónica de tipo inmunológico, con estenosis del conducto pancreático principal. Necesitó tratamiento quirúrgico pancreaticoyeyunostomía longitudinal en Y de Roux, conocido como técnica de Puestow modificada. Se logró mejoría clínica, normalidad de sus...

  16. Caracterização de argamassa modificada por particula vegetal para nivelamento de contrapiso

    OpenAIRE

    Francisca Julia França Ferreira de Melo

    2007-01-01

    Resumo: O presente trabalho se propõe desenvolver uma argamassa para nivelamento de contra piso modificada com partículas vegetais de Pinus caribaea e avaliar suas características físicas e mecânicas. Os resíduos de Pinus utilizados são provenientes do processo de fabricação de lápis. Os traços tiveram seu fator água/cimento determinado pela trabalhabilidade. As misturas foram elaboradas com Cimento Portland CPII-E 32, areia, adição de partículas vegetais de Pinus e água proporcional ao traço...

  17. La Tuberculosis, Una Enfermedad Modificada*

    Directory of Open Access Journals (Sweden)

    Valentin Malagón Castro

    1993-12-01

    Full Text Available

    Con ocasión de un estudio de revisión que hemos llevado a cabo recientemente sobre la tuberculosis osteoarticular, *** se ha apreciado un cambio notable en las características y manifestaciones de esta enfermedad.

    Hemos sido testigos del comportamiento de la tuberculosis en los últimos 40 años. Realizamos la tesis profesional en el Hospital de niños de la Misericordia de Bogotá en el año 1950 (86, basada en el análisis de más de 300 enfermos de Mal de Pott tratados con pobres resultados en esa institución en la época prequimioterápica. Efectuamos estudios de control del tratamiento quirúrgico de esa afección en el Hospital Infantil Lorencita Villegas de Santos y publicamos sus resultados en los años 1975,1980 Y1987 (85-87-88. Los pacientes correspondientes a estas nuevas series, ya en la época de la quimioterapia moderna, presentaban un mejor pronóstico vital y funcional. Cuadro 1A.

    En el decenio 1978-1988 asistimos al descenso espectacular de la frecuencia de tuberculosis osteoarticular en las salas de nuestros hospitales. Posteriormente hemos sido igualmente testigos de su lenta y progresiva reaparición.

    El estudio actual nos ha mostrado profundos cambios, como ya se ha dicho, en el comportamiento de la entidad, por lo que estamos de acuerdo en denominarla: La tuberculosis, una enfermedad modificada, diferente a la que hasta hace un década parecía derrotada, vencida por las nuevas drogas y las recientes técnicas quirúrgicas.

    La actual es una enfermedad diferente que ha tomado una fuerza avasalladora que amenaza con volverse resistente al tratamiento específico y dar lugar a una pandemia de incalculables proporciones y de terribles consecuencias para la humanidad.

    El objeto de publicar este estudio es recordar a nuestros colegas, en especial a aquellos de las nuevas promociones que quizás no han tenido la oportunidad de estar en contacto con pacientes de tuberculosis osteoarticular, de

  18. Escala RIPASA para el diagnóstico de apendicitis aguda: comparación con la escala de Alvarado modificada

    Directory of Open Access Journals (Sweden)

    C.Z. Díaz-Barrientos

    2018-04-01

    Full Text Available Resumen: Introducción y objetivos: La apendicitis aguda es la primera causa de las urgencias quirúrgicas. Permanece como un diagnóstico difícil de establecer, particularmente entre jóvenes, ancianos y mujeres en edad reproductiva, en los cuales una serie de condiciones inflamatorias pueden presentar síntomas y signos similares a los de la apendicitis aguda. Diversos sistemas de puntuación se han creado con el fin de incrementar la certeza diagnóstica; estos son baratos, no invasivos y fáciles de usar o reproducir. La escala de Alvarado modificada es probablemente la más difundida y de mayor aceptación en los servicios de urgencias del mundo. Por otro lado, la escala RIPASA fue elaborada en 2010 con mejor sensibilidad y especificidad. En México se encuentran pocos estudios que comparen los diversos sistemas de puntuación en apendicitis. El objetivo es comparar la escala de Alvarado modificada y la escala RIPASA para el diagnóstico de pacientes con dolor abdominal y sospecha de apendicitis aguda. Material y métodos: Se realizó un estudio observacional, analítico y prolectivo, de julio de 2012 a febrero 2014 en el Hospital Universitario de Puebla. Las encuestas en proceso de evaluación fueron aplicadas a los pacientes con sospecha clínica de apendicitis. Resultados: Escala de RIPASA: curva ROC/PC 8.5 (área 0.595, sensibilidad (93.3%, especificidad (8.3%, VPP (91.8%, VPN (10.1%. Escala de Alvarado modificada: Curva ROC/PC 6 (área 0.719, sensibilidad (75%, especificidad (41.6%, VPP (93.7%, VPN (12.5%. Conclusiones: La escala de RIPASA contrastada con la escala de Alvarado modificada no mostró ventajas al aplicarse a pacientes con sospecha de apendicitis aguda. Abstract: Introduction and objectives: Acute appendicitis is the first cause of surgical emergencies. It is still a difficult diagnosis to make, especially in young persons, the elderly, and in reproductive-age women, in whom a series of inflammatory conditions can have

  19. Evaluación de la técnica modificada de Dennis para el diagnóstico de fasciolosis bovina

    Directory of Open Access Journals (Sweden)

    Stefanya Correa

    2016-04-01

    Conclusión. La validez y el desempeño de la técnica modificada de Dennis fueron superiores a los de la técnica tradicional, por lo que constituye una buena heramienta de tamización para el diagnóstico de la fasciolosis en estudios poblacionales y de prevalencia, así como en jornadas de salud animal.

  20. Recubrimiento comestible basado en goma arábiga y carboximetilcelulosa para conservar frutas en atmósfera modificada

    Directory of Open Access Journals (Sweden)

    S. Valle-Guadarrama

    2008-01-01

    Full Text Available El objetivo de este estudio fue desarrollar un recubrimiento comestible a base de goma arábiga (GA, carboximetilcelulosa (CMC y glicerol (GL como plastificante, para valorar su potencial de uso en sistemas de conservación de frutos en atmósfera modificada, mediante la evaluación de sus propiedades mecánicas, de barrera a gases y de transmisión de luz. En una fase de diseño evolutivo se obtuvo una formulación aproximada del recubrimiento; con esta base se definieron rangos de concentraciones de GA (20 y 30 %, CMC (0.25, 0.50 y 0.75 % y GL (5, 10 y 15 % para caracterizar el material. La combinación de GA en proporción de 30 %, CMC en un rango de 0.25 a 0.50 % y GL en un rango de 5 a 10 %, presentó un potencial adecuado para uso en conservación de frutos mediante sistemas de atmósfera modificada. El cambio de las concentraciones en GA, CMC y GL permitió regular las permeabilidadesa O2 y CO2 y la resistencia mecánica, con una transparencia mayor a 80 %.

  1. Evaluación de bolsa atmósfera modificada y concentraciones de anhídrido sulfuroso aplicadas sobre frutos de arándano alto (Vaccinium corymbosum L.) cv. Emerald

    OpenAIRE

    Mario Rodríguez Beraud; Anddy Wyss Valdés; Nelson Hormazábal Vásquez

    2015-01-01

    Con el objetivo de evaluar las técnicas de atmósfera modificada y aplicación de anhídrido sulfuroso sobre parámetros de calidad de postcosecha en frutos de arándanos (Vaccinium corymbosum L.) cv. Emerald, se realizó un experimento de seis tratamientos, dados por la combinación de dos factores, atmósfera modificada (con y sin), y diferentes concentraciones de anhídrido sulfuroso (generadas por 0, 1 y 2 g de metabisulfito de sodio) durante 7, 14, 21 y 28 días a 0 °C. Con la dosis de 2 g de meta...

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

    OpenAIRE

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

    2012-01-01

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

  3. Diseño de una planta de envasado de patatas en atmósfera modificada

    OpenAIRE

    Roldán Fernández, Rubén

    2012-01-01

    El proyecto pretende diseñar una planta de envasado de patatas, variedad Monalisa, para su comercialización y posterior distribución de este producto hortofrutícola. En dicha planta se realizarán las operaciones de lavado, pelado, selección, corte, secado y envasado en atmósfera modificada (CO2, O2 y N2). El producto envasado se almacenará en cámaras frigoríficas hasta su comercialización. Los españoles consumimos una media de 60,54 Kg de hortalizas frescas por persona y ...

  4. Radiação gama e atmosfera modificada passiva na qualidade de goiabas 'Pedro Sato'

    Directory of Open Access Journals (Sweden)

    André José de Campos

    2011-10-01

    Full Text Available O objetivo deste trabalho foi avaliar o efeito da irradiação gama associada à atmosfera modificada passiva na qualidade pós-colheita de goiabas 'Pedro Sato', verificando suas características físico-químicas. Foram utilizadas goiabas provenientes da região de Vista Alegre do Alto-SP,Brasil. Após a colheita, as goiabas foram imediatamente transportadas ao Laboratório de Frutas e Hortaliças, pertencente ao Departamento de Gestão e Tecnologia Agroindustrial, da Faculdade de Ciências Agronômicas - UNESP - Câmpus de Botucatu-SP, onde foram armazenadas a 10ºC e 90-95%UR, em câmara frigorífica, por 28 dias. Os tratamentos foram: controle 1 (sem embalagem e sem irradiação; controle 2 (embalagem de poliestireno (PS + polietileno de baixa densidade (PEBD e sem irradiação; tratamento 1 (PS+PEBD e 0,2kGy; tratamento 2 (PS+PEBD e 0,6kGy, e tratamento 3 (PS+PEBD e 1,0kGy. As análises realizadas foram: firmeza, sólidos solúveis (SS, acidez titulável (AT e índice de maturação. Foi utilizado o delineamento inteiramente casualizado, com esquema fatorial 5 x 5 (tratamento x tempo. Concluiu-se que as altas doses de irradiação promoveram efeito negativo nas características físico-químicas da goiaba 'Pedro Sato', e que apenas a menor dose utilizada (0,2kGy associada à atmosfera modificada conservou frutos com maior qualidade e aceitabilidade, indicado por maiores índice de maturação e teor de sólidos solúveis obtidos.

  5. COMPORTAMIENTO DE UNA MEZCLA DENSA DE ASFALTO EN CALIENTE MODIFICADA CON DESECHO DE POLICLORURO DE VINILO (PVC

    Directory of Open Access Journals (Sweden)

    Hugo Alexander Rondón Quintana

    2008-01-01

    Full Text Available En el mundo la tecnología de los asfaltos modificados ha sido una técnicaampliamente utilizada para mejorar las características que presentan las mezclasasfálticas convencionales cuando experimentan niveles elevados de tránsito ygradientes de temperatura. Por lo general lo que se busca con este tipo detecnología es mejorar algunas de las propiedades mecánicas y reológicas de losasfaltos y las mezclas asfálticas convencionales tales como la susceptibilidad térmica, la rigidez, y la resistencia al envejecimiento, a las deformaciones plásticas ya la fatiga. El artículo presenta los resultados experimentales de ensayar una mezcla asfáltica densa en caliente modificada con desecho de policloruro de vinilo (el cual se denominará en el presente trabajo PVC. Para la evaluación del comportamiento de las mezclas asfálticas convencionales y modificadas se realizaron ensayos Marshall, módulo dinámico y deformación permanente. Para el cemento asfáltico (CA con y sin aditivo se realizaron ensayos de caracterización de asfaltos como penetración, punto de ablandamiento y viscosidad. La modificación de las mezclas se realizó por vía húmeda y seca. Adicionando desecho de PVC al cemento asfáltico y a las mezclas, se obtiene un material más rígido con mayor resistencia a la penetración y menor susceptibilidad térmica a fluir.

  6. Avaliação de diferentes tipos de atmosferas modificadas na vida útil de carambolas minimamente processadas

    OpenAIRE

    Neves,Leandro Camargo; Prill,Marcos André de Souza; Silva,Vanuza Xavier da; Benedette,Ronaldo Moreno; Vieites,Rogério Lopes

    2006-01-01

    Este trabalho teve por objetivo a avaliação da vida útil potencial de carambolas cv. Golden Star, minimamente processadas, armazenadas em diferentes tipos de embalagens plásticas, para a concepção da atmosfera modificada. Os frutos colhidos fisiologicamente maturos apresentaram coloração verde-amarelada, sólidos solúveis (SS) médios de 6,8 ºBrix e massa média de 185 g. Antes da aplicação dos tratamentos, os frutos foram selecionados, higienizados em solução de hipoclorito de sódio (NaOCl) a 1...

  7. Avaliação do tratamento cirúrgico da doença de Dupuytren pela técnica da palma aberta modificada

    Directory of Open Access Journals (Sweden)

    Thiago Almeida Guilhen

    2014-01-01

    Full Text Available Objetivo: avaliar o tratamento cirúrgico com o uso da técnica da palma aberta modificada para o tratamento das contraturas graves da doença de Dupuytren. Métodos: em quatro anos, foram submetidos ao tratamento cirúrgico 16 pacientes, que pertenciam aos estágios III e IV da classificação proposta por Tubiana et al. Foram feitas aferições do déficit de extensão das articulações metacarpofalangeanas e inferfalangeana proximal e distal nos períodos pré-operatório, pós-operatório (três meses e pós-operatório tardio (cinco a oito anos. Angulações maiores do que 30° nas articulações metacarpofalangeanas e 15° nas interfalangeanas proximais foram consideradas como recidiva cirúrgica. Resultados: obtivemos uma média de déficit de extensão de 6,3° ao nível da articulação metacarpofalangeana, 13,8° na interfalangeana proximal e 1,9° na interfalangeana distal. Conclusão: a técnica da palma aberta modificada é um método eficaz no tratamento cirúrgico das contraturas graves na doença de Dupuytren.

  8. Desenvolvimento de massas alimenticias instantaneas de arroz, pelo processo de extrusão termoplastica, utilizando farinhas quimicamente modificadas

    OpenAIRE

    Elizabeth Harumi Nabeshima

    2007-01-01

    Resumo: Esta pesquisa consistiu em apresentar uma alternativa de utilização da farinha de arroz através da modificação química (fosfatação ou acetilação), agregando-lhe valor e possibilitando ampliar sua utilização como ingrediente alimentício, especialmente na produção de massas alimentícias instantâneas sem glúten. Inicialmente a farinha de arroz foi modificada quimicamente, sendo acetilada ou fosfatada, utilizando-se anidrido acético (0,465; 1,500; 4,000; 6,500 e 7,535g/100g farinha) ou ox...

  9. Qualidade da alface crespa minimamente processada acondicionada em atmosfera modificada Quality of minimally processed crisp head lettuce packaged under modified atmosphere

    Directory of Open Access Journals (Sweden)

    Rosana Mendes Roversi

    2004-08-01

    Full Text Available A alface Crespa (Lactuca sativa L.foi minimamente processada, tendo suas folhas destacadas e higienizadas, embalada em sacos plásticos de polietileno com modificação ativa da atmosfera dentro do pacote. Duas atmosferas foram aplicadas, variando-se o nível de CO2 em 10 e 15%, reduzindo nos dois casos o O2 a 5%. Após o acondicionamento, a alface foi imediatamente refrigerada. Comparou-se a qualidade da alface com e sem atmosfera modificada durante o armazenamento refrigerado. Monitoraram-se a variação da concentração de O2 e CO2 no interior das embalagens e a vida-útil da alface pela análise sensorial e microbiológica e a variação de sólidos solúveis. A influência da atmosfera modificada no crescimento de microrganismos e na variação de sólidos solúveis não foi relevante. Entretanto, essa tecnologia reduziu as taxas de respiração e, conseqüentemente, minimizou as perdas de qualidade sensorial da alface durante todo o armazenamento. A vida-útil da alface em atmosfera modificada foi estendida em até cinco dias além daquela alcançada pela alface acondicionada em atmosfera normal.The crisp head lettuce (Lactuca sativa L.was minimally processed, with the leaves being detached and cleaned, packaged in plastic bags made of polyethylene with modified atmosphere inside the bag. Two different atmospheres were applied: 10 and 15% of CO2, with the O2 level being reduced in both cases to 5%. After the packing, the lettuce was immediately refrigerated. The product quality with and without modified atmosphere was compared during the storage time. It was accompanied the changes in O2 and CO2 concentration inside the packaging and the product shelf life, through sensorial and microbiological analysis, and soluble solids variation. The influence of modified atmosphere in microorganisms grown and in soluble solids variation was not relevant. However this technology reduced the lettuce respiration rates and the quality sensorial loss

  10. Qualidade de uva 'Isabel' tratada com cloreto de cálcio em pós-colheita e armazenada sob atmosfera modificada

    Directory of Open Access Journals (Sweden)

    Rosana Sousa da Silva

    2012-03-01

    Full Text Available Uvas 'Isabel' foram tratadas após a colheita com cloreto de cálcio (CaCl2 e submetidas a atmosfera modificada para avaliação da manutenção de sua qualidade durante o armazenamento, a 12±1 ºC e 85±2% de UR. O experimento foi conduzido em delineamento inteiramente casualizado, em esquema fatorial 5 x 2 x 5, com 3 repetições, sendo cinco doses de CaCl2 (0,0; 0,5; 1,0; 2,0 e 4,0%, dois tipos de atmosfera [ambiente e modificada (AM] e cinco períodos, durante o armazenamento refrigerado. As avaliações foram acidez titulável (AT, sólidos solúveis (SS, relação SS/AT, pH, ácido ascórbico, incidência de podridão, perda de massa, aparência do engaço e índice de degrana. A AM reduziu a perda de massa, a incidência de podridão e manteve a aparência verde do engaço, ampliando a vida útil de uva 'Isabel' em seis dias. Doses de CaCl2 entre 0,5 e 2,0% reduziram a incidência de podridão. A aplicação de CaCl2 associado à AM reduziu a degrana em uva 'Isabel' durante o armazenamento refrigerado.

  11. Evaluación del aparato respiratorio en trabajadores expuestos a polvo del mineral zeolita

    Directory of Open Access Journals (Sweden)

    Guillermo López Espinosa

    1999-01-01

    Full Text Available Se realizó un estudio observacional de tipo transversal en la Mina-Planta de Zeolita Tasajeras, que pertenece al municipio de Ranchuelo, Villa Clara, en el período comprendido entre junio y septiembre de 1997, con el objetivo de determinar el estado clínico y funcional ventilatorio de los trabajadores. A los 73 pacientes con 2 o más años en la fábrica se les aplicó un cuestionario, y se les realizó un examen físico y una prueba funcional ventilatoria. Los resultados más relevantes corroboran que los trabajadores del área de mayor exposición al polvo refieren un mayor número de síntomas respiratorios, sobre todo los fumadores. Sin embargo, el 94,5 % presenta un examen físico de tórax negativo, el 68,8 % de los pacientes con prueba funcional ventilatoria patológica integran el área planta, son fumadores el 62,5 %, y el 63,1 % no usa con frecuencia el filtro respiratorio como medio de protección individualA croos-sectional observational study was carried out at the mine-plant zeolite in Tasajeras, municipality of Ranchuelo, Villa Clara, from June to September, 1997, aimed at determining the clinical and functional ventilatory status of the workers. 73 patients with 2 or more years in the factory answered a questionnarie and underwent a physical examination and a functional ventilatory test. According to the results, those workers that were more exposed to dust had a higher number of respiratory symptoms, mainly smokers. However, 94,5 % had a negative chest physical examination. 68.8 % of the area patients with pathological functional ventilatory test work in the of the plant. 62.5 % are smokers and 63.1 % do not use frequently the respiratory filter as a menas of individual protection.

  12. Armazenamento de melão 'Orange Flesh' minimamente processado sob atmosfera modificada Storage of 'Orange Flesh' mellons minimally processed and packaged under modified atmosphere

    Directory of Open Access Journals (Sweden)

    Mônica Elisabeth Torres Prado

    2005-04-01

    Full Text Available O aumento da demanda por produtos minimamente processados traz um grande desafio para a ciência e tecnologia de alimentos, considerando-se a escassez de informações sobre a manutenção da qualidade desses produtos. O armazenamento desses em condições adequadas é um ponto fundamental para o sucesso dessa tecnologia. Objetivou-se com este trabalho avaliar o efeito da atmosfera modificada ativa na conservação do melão tipo Orange Flesh minimamente processado. Os frutos, após o processamento, foram embalados sob atmosfera modificada (AM Passiva- Controle, AM Ativa com 5% de CO2 e 5% de O2 e AM Ativa com 10% de CO2 e 2% de O2, armazenados em câmara fria (6 ± 1 ºC e UR 85 ± 5% durante 8 dias e as amostras retiradas para análises de pH, sólidos solúveis totais (SST, acidez total titulável (ATT, açúcares solúveis totais (AST, firmeza, pectina total (PT, pectina solúvel (PS, e as enzimas pectinametilesterase (PME e poligalacturonase (PG a cada 2 dias de armazenamento. A atmosfera modificada ativa pouco influenciou no comportamento das variáveis pH, acidez total titulável (ATT, firmeza e pectina total com relação á atmosfera modificada passiva. No entanto, menor solubilização de pectinas foi detectada nas amostras armazenadas sob atmosfera com 10% de CO2 e 2% de O2. Não foram detectadas atividades das enzimas pectinametilesterase e poligalacturonase nos tratamentos analisados.The increase of the demand for products minimally processed brings a great challenge for the food science and technology, considering the shortage of information about the maintenance of the quality of those products. The storage of those products in appropriate conditions is a fundamental point for the success of such technology. The objective of this work was to evaluate the effect of the active modified atmosphere on the quality and conservation of the 'Orange Flesh' melons processed minimally. The fruits, after the processing, were wrapped under

  13. Potencial de cruzamento natural entre o arroz transgênico resistente ao herbicida glufosinato de amônio e o arroz daninho

    OpenAIRE

    Noldin,J.A.; Yokoyama,S.; Antunes,P.; Luzzardi,R.

    2002-01-01

    A utilização de cultivares de arroz irrigado resistentes a herbicidas não-seletivos, como o glufosinato de amônio, pode se constituir numa alternativa de controle de arroz daninho em lavouras de arroz irrigado. O objetivo deste trabalho foi avaliar a taxa e o sentido do cruzamento natural entre plantas de uma linhagem modificada geneticamente para resistência ao herbicida glufosinato de amônio (arroz GM) e ao arroz daninho. A taxa de cruzamento natural entre o arroz GM como receptor feminino ...

  14. Envasado de Carne de Vacuno con Hueso y Grasa en Atmósfera Modificada con CO2 y CO

    OpenAIRE

    Aspé, Estrella R; Roeckel, Marlene D; Martí, Cristina; Jiménez, Romel

    2008-01-01

    Se evaluó el efecto de envasado en atmósfera modificada (MAP) con bajo contenido de CO (0.1% y 0.4%) y presencia de CO2 sobre el color rojo y la vida útil de carne de vacuno. Se determinaron características microbiológicas, fisicoquímicas, organolépticas-sensoriales y de color del músculo y se compararon los resultados con el MAP de 70%O2+30%CO2. La vida útil de las muestras con O2 fue de 30 días mientras que para las muestras en MAP la vida útil fue de 40 a 45 días y no dependió de la concen...

  15. Evaluación de la eficiencia de una batería de filtros empacados en zeolita en la remoción de metales pesados presentes en un licor mixto bajo condiciones de laboratorio Evaluation of efficiency of a filter battery packaging zeolite in the removal of heavy metals in a mixed liquor under laboratory conditions

    OpenAIRE

    Diana Rocío Acevedo Cifuentes; Sandra Milena Builes Felizzola; Carlos Andrés Ordóñez Ante; Idalia Jacqueline López Sánchez

    2011-01-01

    En este artículo se muestran resultados de investigación obtenidos en la remoción de los metales pesados, plomo, níquel, cromo, cadmio y mercurio, presentes en una solución compuesta por licor mixto proveniente de la planta de tratamiento de aguas residuales de San Fernando y una solución preparada con metales pesados con una concentración conocida, mediante el uso de una batería de filtros empacados en zeolita clinoptilolita. La experimentación se desarrolló bajo condiciones controladas de c...

  16. Synthesis and characterization of zeolite from coal ashes modified by cationic surfactant; Sintese e caracterizacao de zeolita de cinzas de carvao modificada por surfactante cationico

    Energy Technology Data Exchange (ETDEWEB)

    Fungaro, D.A.; Borrely, S.I., E-mail: dfungaro@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2012-01-15

    Zeolite synthesized from coal fly ash was modified with different concentrations (2 and 20 mmol.L{sup -1}) of hexadecyltrimethylammonium bromide (HDTMA-Br). The Non-Modified Zeolite (NMZ) and Surfactant-Modified Zeolites (SMZ) were characterized by X-ray fluorescence spectrometry, X-ray diffraction, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy, thermogravimetric analysis, among others. The SMS presented negative charge probably due to the formation of a partial bilayer of HDTMA on exchangeable active sites on the external surface of NMZ. A decrease in surface area was observed for SMZ as compared to NMZ indicating zeolite surface coverage with HDTMA-Br molecules. The crystalline nature of the zeolite remained intact after adsorption of surfactant and heating for drying. FTIR analysis indicated that there were no significant changes in the structure of the zeolite after adsorption of surfactant. (author)

  17. Ammonia removal from high salt waste water using natural zeolite; Remocao de amonia de efluentes de alta salinidade utilizando zeolita natural

    Energy Technology Data Exchange (ETDEWEB)

    Geraldo, Lucia M.L. [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil); Arroyo, Pedro A. [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil). Centro de Pesquisas; Barros, Maria Angelica S.D.; Pazin, Elenice [Universidade Estadual de Maringa (UEM), PR (Brazil). Dept. de Quimica; Zola, Andreia S.; Zschornack, Marlon A. [Universidade Estadual de Maringa (UEM), PR (Brazil). Dept. de Quimica. Pos-Graduacao em Engenharia Quimica

    2008-07-01

    The present work aimed to study ammonium ion exchange using a fixed bed of natural zeolite clinoptilolite. First of all, it was carried out a bi component ion exchange of ammonium (150 mg/L) in the presence of K{sup +}, Ba{sup 2+}, Ca{sup 2+}, Sr{sup 2+} e Mg{sup 2+}. Thus, clinoptilolite showed a preference for strontium, barium and potassium cations, while there is a higher preference for Nh{sub 4}{sup +} cations instead calcium and magnesium. Secondly, it was studied the multicomponent ion exchange of ammonium (solution containing all cations). It was observed that the presence of competing cations decreases the content of ammonium retained in the bed until breakthrough point. Furthermore, it was also verified that multicomponent exchange in the presence of high salinity solution (60.000 mg/L of Na{sup +}), sodium influences the ion exchange mechanism, decreasing the up take capacity of ammonium for zeolitic bed. On the other hand, ammonium capture increases in the presence of natural effluent that possesses lower salinity (30.000 mg/L). Therefore, the results obtained evidence the application potentiality of clinoptilolite for ammonia up takes from industrial effluents, in what competition conditions by others cations are too severe and for that the zeolite natural presented good performance. (author)

  18. Performance of natural and modified smectite: kinetic and thermodynamics involving arsenic (V adsorption Desempenho de esmectita natural e modificada: cinética e termodinâmica envolvendo adsorção de arsênio (V

    Directory of Open Access Journals (Sweden)

    D. L Guerra

    2010-03-01

    Full Text Available A natural smectite sample has been modified by organofunctionalization process using synthetic route involved the reaction of 2-mercaptopyrimidine with 3-chloropropyltriethoxysilane. The resulting material (S MPY was characterized by SEM, FTIR, textural analysis and 29Si MAS-NMR. The ability of this material to removed As (V from aqueous solution was followed by series of adsorption isotherms adjusted to the Langmuir equation at room temperature and pH 2.0. The kinetic parameters analyzed by Lagergren and Elovich models gave a good fit for a pseudo-second order reaction with k2 in the 4.9 to 14.0 mmol-1 min-1 range for S MPY. The adsorption process was exothermic (ΔintH = -4.09 to -5.79 kJ.mol-1 accompanied by increase in entropy (ΔintS = 41.29 to 61.80 JK-1.mol-1 and Gibbs energy (ΔintG = -22.34 to -24.19 kJmol-1. The energetic effect caused by arsenic cation adsorption was determined through calorimetric titration at the solid-liquid interface and gave a net thermal effect that enabled the calculation of the exothermic values and the equilibrium constant.Uma amostra de esmectita natural foi modificada por processo de organofuncionalização usando rota sintética, envolvendo a reação de 2-mercaptopirimidina com 3-cloropropiltrietoxisilano. O material resultante (S MPY foi caracterizado por microscopia eletrônica de varredura, espectroscopia de infravermelho com transformada de Fourier, análise textural e 29Si MAS-NMR. A habilidade deste material para remover As (V a partir de solução aquosa foi investigada por series de isotermas ajustadas pela equação de Langmuir em temperatura ambiente e pH 2,0. Os parâmetros cinéticos foram analisados por modelos de Lagergren e Elovich, em que um bom ajuste foi obtido para o modelo de reação de pseudo-segunda ordem com k2 em 4,9 para 14,0 mmol-1 min-1 para S MPY. O processo de adsorção foi exotérmico (ΔintH = -4,09 to -5,79 kJmol-1 acompanhado por aumento de entropia (ΔintS = 41,29 to 61

  19. Aceite de girasol, semillas y plantas con distribución modificada de ácidos grasos en la molécula de triacil-glicerol

    OpenAIRE

    Garcés Mancheño, Rafael; Martínez-Force, Enrique

    2003-01-01

    El objeto de la presente invención es un aceite de girasol que se obtiene directamente de la semilla de girasol con de 12-40,8% de ácido esteárico calculado en relación al contenido total de ácidos grasos y con una distribución de ácidos grasos modificada entre las posiciones sn-1 y sn-3 de la molécula de triacilglicerol (TAG) comparado con el aceite obtenido del tipo silvestre de semillas de girasol. La invención también se refiere a una planta de girasol y a semillas que contien...

  20. Dyes adsorption blue vegetable and blue watercolor by natural zeolites modified with surfactants;Adsorcion de colorantes azul vegetal y azul acuarela por zeolitas naturales modificadas con surfactantes

    Energy Technology Data Exchange (ETDEWEB)

    Jardon S, C. C.; Olguin G, M. T. [ININ, Departamento de Quimica, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Diaz N, M. C., E-mail: teresa.olguin@inin.gob.m [Instituto Tecnologico de Toluca, Av. Instituto Tecnologico s/n, Ex-Rancho la Virgen, 52140 Metepec, Estado de Mexico (Mexico)

    2009-07-01

    In this work was carried out the dyes removal blue vegetable and blue watercolor of aqueous solutions, to 20 C, at different times and using a zeolite mineral of Parral (Chihuahua, Mexico) modified with hexadecyl trimethyl ammonium bromide or dodecyl trimethyl ammonium bromide. The zeolite was characterized before and after of its adaptation with NaCl and later with HDTMABr and DTMABr. For the materials characterization were used the scanning electron microscopy of high vacuum; elementary microanalysis by X-ray spectroscopy of dispersed energy and X-ray diffraction techniques. It was found that the surfactant type absorbed in the zeolite material influences on the adsorption process of the blue dye. Likewise, the chemical structure between the vegetable blue dye and the blue watercolor, determines the efficiency of the color removal of the water, by the zeolites modified with the surfactants. (Author)

  1. FRIGOCONSERVACIÓN Y ATMÓSFERAS MODIFICADAS EN FRUTOS DE AGUACATE MÍNIMAMENTE PROCESADO

    Directory of Open Access Journals (Sweden)

    J. A. Zarazúa-Escobar

    2005-01-01

    Full Text Available Este estudio tuvo como objetivo evaluar el efecto de dos atmósferas modificadas, una generada por polietileno de baja densidad lineal y el uso de Vacum 300, a dos temperaturas de almacenamiento 5 y 20 °C, así como el uso de antioxidantes (B-tocoferol, ácido Lascórbico y butilhidroxi-tolueno en la prolongación de la vida de anaquel de aguacate mínimamente procesado. Se evaluó la pérdida fisiológica de peso, color, firmeza, daños por frío, potencial de obscurecimiento, compuestos fenólicos, actividad de la polifenoloxidasa, incidencia y severidad de enfermedades, y evaluación sensorial. El mejor tratamiento fue el de película para vacío, Vacum 300 con antioxidantes (B-tocoferol, ácido L-ascórbico y butilhidroxi-tolueno almacenado a 5 °C, el cual tuvo la capacidad de mantener un aroma y apariencia aceptables en las rebanadas de aguacate. También redujo de forma considerable la pérdida fisiológica de peso, aminoró los desórdenes causados por el frío y conservó al producto en perfectas condiciones (libre de hongos a lo largo de 13 días.

  2. Qualidade do abacate 'HASS' frigoarmazenado submetido a atmosferas modificadas ativas

    Directory of Open Access Journals (Sweden)

    Rogério Lopes Vieites

    2014-06-01

    Full Text Available O objetivo deste trabalho foi avaliar a conservação do abacate 'Hass'frigoarmazenado submetido a atmosferas modificadas ativas. Os frutos foram acondicionados em embalagem de náilon+polietileno e submetidos à injeção de mistura de gases, constituindo os tratamentos: I - mistura gasosa do ambiente (21,0 kPa de O2+0,03 kPa de CO2; II - 4,0 kPa de O2+5,0kPa de CO2 ; III - 4,0 kPa de O2+6,0 kPa de CO2 ; IV - 4,0 kPa de O2+7,0 kPa de CO2, e V- 4,0 kPa de O2+8,0 kPa de CO2. As embalagens contendo os frutos foram armazenadas em câmara frigorífica, a uma temperatura de 10±1ºC e umidade relativa de 90±5%, durante 25 dias, sendo as análises realizadas a cada 5 dias. As análises realizadas foram perda de massa, atividade respiratória, potencial hidrogeniônico (pH, firmeza, acidez titulável (AT, sólidos solúveis (SS e atividade das enzimas pectinametilesterase (PME e poligalacturonase (PG. O tratamento em que os frutos foram submetidos à pressão parcial de 4,0 kPa de O2+7,0 kPa de CO2 foi o mais efetivo na conservação dos frutos, principalmente pela menor perda de massa e baixa produção de CO2.

  3. Remoción de Fe y Mn en aguas naturales por adsorción-oxidación sobre clinoptilolita

    Directory of Open Access Journals (Sweden)

    Carolina Cuchimaque Lugo

    2013-01-01

    Full Text Available En el presente trabajo de investigación se comprueba la eficiencia en la remoción de Fe y Mn de aguas naturales por el empleo de un medio adsorbente que consiste de zeolita natural (clinoptilolita, recubierta con Fe 2O3 y MnO2 a partir de FeCl3 y MnSO4, respectivamente. La zeolita por su gran capacidad de intercambio de cationes es un excelente soporte de estos óxidos. El mecanismo de la remoción es por adsorción-oxidación de estos metales sobre la superficie de la capa de óxido que cubre el grano de zeolita. En las pruebas de remoción mediante un sistema de filtración se estudiaron las variables pH, concentraciones de Fe y Mn, caudal en el a fluente y altura de la capa de la zeolita, resultando las dos últimas ser las de mayor relevancia en la remoción. Se utilizaron concentraciones de 1,0-7,0 mg/L para Fe y de 0,5-3,0 mg/L para Mn, en un rango de pH de 6,0-8,0. La eficiencia de la remoción disminuye con el aumento en la concentración de Fe, especialmente a valores de pH altos (> 7,5, por la formación de precipitados de Fe2O3 causando aceleración en la saturación del medio. No se obtuvo una diferencia significativa sobre la remoción con el empleo de los dos tipos de recubrimiento, aunque a altas concentraciones de estos metales, con la capa de Fe 2O3 se obtuvieron porcentajes de remoción un poco mayores, pero la desventaja es que con este tipo de óxido se obtuvo menor corrida de los filtros por la saturación del medio.

  4. Implementación de la filosofía hooponopónica modificada en el programa terapéutico para pacientes que funcionan a nivel neurótico

    Directory of Open Access Journals (Sweden)

    Roberto Anselmo Ramos Valverde

    2014-09-01

    Full Text Available Se fundamenta la implementación de la filosofía hooponopónica, modificada en el programa terapéutico de los pacientes que funcionan a nivel neurótico en el Hospital de Día de Las Tunas, lo cual responde a una de las líneas de investigación del proyecto institucional FiloArtMed. La filosofía hooponopónica de fundamento idealista, exotérico y negador de la realidad, de orígenes milenarios en Hawái, fue modificada teniendo en cuenta el significado de sus palabras claves: perdóname, gracias, lo siento, te amo, de acuerdo a los preceptos dialécticos materialistas de la Medicina y la Psicología cubanas, insertándola en el programa terapéutico integral del hospital de día para pacientes neuróticos como técnica cognitiva conductual reguladora del comportamiento, rectorizando las terapias a manera de núcleo terapéutico. Se desecharon sus preceptos acientíficos tradicionales y se incluyó, además, el ejercicio de meditación, derivado de esta filosofía, basado en el principio de la neuroplasticidad cerebral, como técnica de relajación y de limpieza mental, fungiendo como la entrada B de la psicoterapia grupal sistémica de regulación emocional

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

    Directory of Open Access Journals (Sweden)

    Nancy Eggs

    2012-01-01

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

  6. Tratamiento quirúrgico de la pancreatitis aguda con técnica de Puestow modificada

    Directory of Open Access Journals (Sweden)

    Enrique Vázquez Merayo

    Full Text Available La pancreatitis crónica representa uno de los mayores desafíos de la Gastroenterología, y su etiología sigue siendo difícil de establecer en 10-30 % de los pacientes. Se presenta un paciente masculino, de 13 años, con diagnóstico de pancreatitis crónica de tipo inmunológico, con estenosis del conducto pancreático principal. Necesitó tratamiento quirúrgico pancreaticoyeyunostomía longitudinal en Y de Roux, conocido como técnica de Puestow modificada. Se logró mejoría clínica, normalidad de sus enzimas en una semana, no hubo complicaciones, tuvo evolución posoperatoria satisfactoria, y una estadía hospitalaria de 14 días. Actualmente se mantiene con 4 años de evolución satisfactoria. La técnica efectuada en el paciente es considerada por muchos como la ideal, por su baja incidencia de mortalidad (menos del 3 % y por el alivio del dolor en más del 75 % de los pacientes. Por ello, se considera que esta técnica quirúrgica pudiera ser una opción terapéutica eficaz para este tipo de paciente.

  7. Impacto intraoperatorio de la ultrafiltración modificada en pacientes pediátricos sometidos a cirugía cardíaca con circulación extracorpórea

    Directory of Open Access Journals (Sweden)

    Pedro José Curi-Curi

    2016-07-01

    Conclusiones: La ultrafiltración modificada puede beneficiar a los pacientes pediátricos no neonatales con cardiopatía congénita operados con bomba porque es capaz de disminuir la concentración sérica de IL-6, IL-10 y lactato post-CEC. Adicionalmente, puede ayudar a filtrar C4d y a remover el exceso de líquido que promovería una mayor hemoconcentración, por lo que se recomienda su uso rutinario cuando las condiciones hemodinámicas lo permitan.

  8. Manejo do etileno em ameixas 'Laetitia' armazenadas sob atmosferas controlada e modificada ativa

    Directory of Open Access Journals (Sweden)

    Thais Roseli Corrêa

    2011-09-01

    Full Text Available O objetivo deste trabalho foi avaliar o efeito de condições de atmosfera controlada (AC e atmosfera modificada (AM ativa (filme PEBD de 40 µm, com duas perfurações de 1,0 mm de diâmetro, associadas ao manejo do etileno, sobre a manutenção da qualidade em ameixas 'Laetitia'. Os tratamentos avaliados consistiram no armazenamento refrigerado (60 dias a 0,5±0,1ºC em: atmosfera refrigerada (AR; 21,0 kPa O2 + <0,03 kPa CO2; AM; AM + baixo etileno (BE; AC; e AC + 1-MCP (1,0 µL L-1. As pressões parciais de O2 + CO2 (kPa foram de 1,0 + 1,0 e 2,5 + <0,1, em AC e AM, respectivamente. Os frutos armazenados em AC, independentemente do tratamento com 1-MCP, apresentaram retardo no amadurecimento, quando comparados aos frutos em AR. Contudo, os melhores resultados para a manutenção da textura da polpa e da acidez titulável foram obtidos em AC + 1-MCP. Os tratamentos não interferiram para a incidência de podridões, rachaduras e degenerescência da fruta. Frutos dos tratamentos AM + BE e AC + 1-MCP apresentaram menor escurecimento da polpa e maior aceitabilidade quanto à cor e ao sabor na análise sensorial em relação àqueles armazenados em AR.

  9. Evaluación de la eficiencia de una batería de filtros empacados en zeolita en la remoción de metales pesados presentes en un licor mixto bajo condiciones de laboratorio Evaluation of efficiency of a filter battery packaging zeolite in the removal of heavy metals in a mixed liquor under laboratory conditions

    Directory of Open Access Journals (Sweden)

    Diana Rocío Acevedo Cifuentes

    2011-01-01

    Full Text Available En este artículo se muestran resultados de investigación obtenidos en la remoción de los metales pesados, plomo, níquel, cromo, cadmio y mercurio, presentes en una solución compuesta por licor mixto proveniente de la planta de tratamiento de aguas residuales de San Fernando y una solución preparada con metales pesados con una concentración conocida, mediante el uso de una batería de filtros empacados en zeolita clinoptilolita. La experimentación se desarrolló bajo condiciones controladas de caudal y pH, a temperatura ambiente. Se encontró que la eficiencia de los filtros bajo las condiciones específicas de diseño es significativamente alta en la remoción de los metales pesados evaluados en la solución acuosa. Se encontró, además, que sin importar el valor de la concentración inicial, se obtuvo una remoción importante en los contaminantes luego de pasar por los filtros con una mayor eficiencia en la remoción del mercurio.This article shows the research results on the removal of five heavy metals (lead, nickel, chromium, cadmium and mercury present in a liquor made of a mixture of wastewater from San Fernando wastewater treatment plant and a solution prepared with known concentrations of heavy metals, using a series of batery filters packed with zeolita clinoptilolita. The experiments were run under controlled conditions of flow and pH, at room temperature. It was found that the removal efficiency was significantly high under the specified design conditions; also, it was found an important removal of the contaminants after passing through the filters, independently of the initial concentration, with the highest observed removal for mercury.

  10. Remoción de níquel, cadmio y zinc del agua, utilizando clinoptilolita heulandita

    Directory of Open Access Journals (Sweden)

    Thelma B. Pavón Silva

    2000-01-01

    Full Text Available Se aplica el proceso de intercambio iónico con una zeolita natural obtenida en Taxco, Guerrero, México, para la remoción de Zn, Cd y Ni de soluciones acuosas. Para este proceso, el mineral se homoionizó con cloruro de sodio y posteriormente se puso en contacto con soluciones 0.01 N de sales de nitratos de Zn, Cd y Ni, durante 8 días.

  11. Desenvolvimento de eletrodos de pasta de carbono modificada com 2-aminotiazol sílica gel para a determinação de metais em etanol combustível

    OpenAIRE

    Takeuchi, Regina Massako [UNESP

    2007-01-01

    Neste trabalho foram desenvolvidos métodos eletroanalíticos para a determinação de íons metálicos em etanol combustível, empregando-se eletrodos de pasta de carbono modificada com uma sílica organofuncionalizada com grupos 2-aminotiazol (CPE-SiAt). Foi realizado um estudo comparativo entre dois aglutinantes: Nujol® e parafina; sendo observado que este último foi mais apropriado para aplicações em amostras comerciais de etanol combustível. Além da utilização dos CPE-SiAt, empregou-se também um...

  12. Avaliação da adição de emulsificantes do tipo lecitinas modificadas na cristalização de manteiga de cacau e de chocolate amargo

    OpenAIRE

    Eriksen Koji Miyasaki

    2013-01-01

    Resumo: As lecitinas modificadas de soja estão sendo introduzidas no processamento de chocolates como alternativa à lecitina padrão para melhorar as propriedades reológicas e de cristalização. A influência da adição de 0,2 a 0,8% (m/m) de lecitinas hidrolisada enzimaticamente, hidroxilada, em pó e acetilada na cristalização da manteiga de cacau foi avaliada. No chocolate, foram adicionadas as lecitinas hidrolisada enzimaticamente e hidroxilada nas concentrações de 0,1 a 0,3% (m/m). Os resulta...

  13. Resistance of genetically modified potatoes to Potato virus Y under field conditions Resistência de plantas de batata geneticamente modificadas ao Potato virus Y em condições de campo

    Directory of Open Access Journals (Sweden)

    André Nepomuceno Dusi

    2009-09-01

    Full Text Available The objective of this work was to evaluate the resistance of genetically modified clones of potato to Potato virus Y (PVY under field conditions. Genetically modified plants were compared with nontransformed plants of the same cultivar. The plots were flanked with potato plants infected with both PVYº and PVY N strains (spread lines, in order to provide the experimental area with the source of virus, which was naturally spread by the native aphid population. The experiment was weekly monitored by visual inspections and by DAS-Elisa in the plants produced from the harvested tubers, in order to evaluate the resistance of transgenic plants throughout the plant growth cycle. By the end of the third year, no infection symptoms were observed in the 1P clone; clone 63P showed 1% of infection, in contrast to about 90% of nontransformed plants infected. The stable expression of resistance to PVY provided by the coat protein gene was obtained in genetically modified clones of potato plants cultivar Achat under field conditions, during three consecutive years.O objetivo deste trabalho foi avaliar a resistência de clones geneticamente modificados de batata ao Potato virus Y (PVY em condições de campo. As plantas geneticamente modificadas foram comparadas com plantas não modificadas da mesma cultivar. As parcelas foram delimitadas com plantas infectadas com as estirpes PVYº e PVY N (linhas disseminadoras, para tornar disponível, na área experimental, a fonte de inóculo de vírus, que foi naturalmente disseminada pela população nativa de afídeos. O experimento foi monitorado semanalmente por inspeção visual e por DAS-Elisa nas plantas produzidas a partir dos tubérculos colhidos, para avaliar a resistência de plantas transgênicas ao longo do ciclo de crescimento. Ao final do terceiro ano, nenhum sintoma de infecção foi observado no clone 1P; o clone 63P apresentou 1% de infecção, em contraste com cerca de 90% de plantas-controle infectadas

  14. Pirólise catalítica do PEBD usando como catalisador a vermiculita modificada

    Directory of Open Access Journals (Sweden)

    Franciel Aureliano Bezerra

    2016-01-01

    Full Text Available Resumo O polietileno de baixa densidade (PEBD é um dos polímeros mais usados atualmente, e a grande quantidade desse polímero produzida resulta em toneladas de resíduos, que necessitam ser tratados. Neste trabalho foi realizada a pirólise termocatalítica do PEBD usando como catalisador a argila vermiculita modificada, como alternativa para o tratamento dos resíduos. A argila foi tratada com solução de ácido nítrico a diferentes concentrações e calcinada a 400 °C. Os materiais foram caracterizados por técnicas de difratometria de raios X, termogravimetria, adsorção de nitrogênio e espectroscopia de energia dispersiva. A pirólise térmica e termocatalítica foi realizada em um micro reator acoplado com GC/MS, a 500 °C. O intuito da pirólise de resíduos poliméricos é a obtenção de hidrocarbonetos leves (C<16, que possam ser empregados na indústria química e petroquímica, através de quebras na cadeia polimérica. Os resultados foram satisfatórios, com aumento no rendimento para hidrocarbonetos leves ao empregar os catalisadores chegando a 71,4% de produtos com C<16, enquanto a pirólise térmica resultou apenas de 25,8%.

  15. Arsenic adsorption in pre-treatment natural zeolite with magnesium oxides; Adsorcion de arsenico en zeolita natural pretratada con oxidos de magnesio

    Energy Technology Data Exchange (ETDEWEB)

    Mejia Z, F. [Universidad Autonoma de Baja California, Instituto de Ingenieria, Blvd. Benito Juarez s/n, 21900 Mexicali, Baja California (Mexico); Valenzuela G, J. L.; Aguayo S, S.; Meza F, D., E-mail: fleridam@iq.uson.m [Universidad de Sonora, Departamentos de Geologia e Ingenieria Quimica y Metalurgia, Blvd. Luis Encinas y Rosales s/n, Col. Centro, 83000 Hermosillo, Sonora (Mexico)

    2009-07-01

    A methodology was developed to modify a natural zeolite (chabazite) with magnesium oxide in order to remove arsenic (As{sup +5}) from water for human consumption. It is proposed a magnesium oxide while regarded as an efficient adsorbent for removing metals in water. X-ray diffraction analyses show significant changes in the chabazite due to the presence of oxides and amorphous hydroxides incorporated during the pre-treatment. Experimental design results show an efficiency greater than 90% of As{sup +5} adsorbed in five minutes. The results indicate that the most significant variables affecting the adsorption of As{sup +5} are the initial concentration of As and the solid/liquid ratio. Experimental data fitted better to Freundlich isotherm with a 20.17 mg/g adsorption capability. (Author)

  16. Esternotomia mediana como via preferencial na anastomose de Blalock-Taussig modificada

    Directory of Open Access Journals (Sweden)

    Rogério ABRAHÃO

    1997-04-01

    Full Text Available A abordagem usual para a realização da anastomose de Blalock-Taussig modificada (ABTM tem sido a toracotomia lateral. Esta via acarreta necessariamente trauma ao parênquima pulmonar e acesso difícil por ocasião da operação definitiva. A esternotomia mediana (EM apresenta-se como uma alternativa com certas vantagens. Este trabalho visa avaliar a viabilidade técnica e os resultados da realização da ABTM por EM. Dez pacientes foram submetidos a esta técnica, interpondo-se enxertos de PTFE. A mortalidade imediata foi de 30%, e a tardia de 10%. Complicação imediata ocorreu em 10%. O tempo médio de internação foi 7,0 ± 0,5 dias. A variação da saturação da hemoglobina pré e pós-operatória foi 27,5 ± 11,7% (pThe usual approach for systemic-pulmonary shunts has been right or left thoracotomy and interposition of a PTFE vascular graft between the subclavian and pulmonary arteries. This approach, necessarily causes, trauma to the lungs and some difficulty for dissection and ligation later during definitive surgical correction. Median sternotomy has been used occasionally for right subclavian-pulmonary artery anastomosis with certain advantages over thoracotomy. In this series, 10 patients were submitted to systemic-pulmonary modified Blalock-Taussig shunts by median sternotomy as the first choice. There have been no technical difficulties. The grafts were anastomosed to the right subclavian artery or brachiocephalic trunk. The right pulmonary artery was preferred, but when infeasible, this side of the shunt was made to the pulmonary trunk or left pulmonary artery. There have been 3 early and 1 late death, unrelated to the shunt. Arterial saturation improved by 27.5 ± 11.7% (p<0.001 post-operatively. This technique is viable, with advantages over lateral approach due to easier access, avoiding lung trauma, permitting surgical alternatives and canulation if needed and may facilitate dissection for later ligation.

  17. Qualidade de mandioquinha-salsa minimamente processada e armazenada sob atmosfera modificada Quality of fresh-cut peruvian carrot: use of modified atmosphere

    Directory of Open Access Journals (Sweden)

    Elisângela Elena Nunes

    2009-10-01

    Full Text Available O objetivo deste trabalho foi verificar o efeito da atmosfera modificada, passiva e ativa, sobre a conservação de mandioquinha-salsa minimamente processada da cultivar 'Amarela de Senador Amaral', adquirida de lavoura comercial do Município de Lavras, Minas Gerais (MG. As raízes foram selecionadas, lavadas com detergente neutro e enxaguadas em água corrente. Em seguida, foram imersas em solução de hipoclorito de sódio 300mg L-1, por 15 minutos, e secas em temperatura ambiente. As raízes foram descascadas e cortadas em fatias de aproximadamente 1cm de espessura, imersas em solução de hipoclorito de sódio 50mg L-1, por 10 minutos, drenadas em peneiras plásticas e embaladas. As bandejas contendo as fatias de mandioquinha-salsa foram armazenadas em câmara fria (5±1°C e 98% UR por 15 dias. As seguintes análises foram realizadas a cada três dias: pH, acidez titulável, sólidos solúveis totais, firmeza, valores L* e b*, amido e avaliação sensorial (aparência e cor. O delineamento experimental foi inteiramente ao acaso (DIC, em esquema fatorial 3 x 6, sendo três tipos de atmosferas (passiva; ativa com injeção inicial das misturas: 2% O2 + 10% CO2 e 5% O2 + 5% CO2 e seis tempos de armazenamento (0, 3, 6, 9, 12 e 15 dias, com três repetições. Os valores médios de pH, acidez titulável, sólidos solúveis e firmeza encontrados neste trabalho foram 6,79, 0,13% de ácido málico, 4,04°Brix e 5,17N, respectivamente. A atmosfera modificada ativa (5% de O2 + 5% CO2 determinou maior valor L* às mandioquinhas-salsa minimamente processadas no sexto e no décimo segundo dia de armazenamento, quando comparada com a atmosfera (2% de O2 e 10% CO2. A atmosfera modificada ativa com 5% O2 + 5% CO2 determinou maiores valor b* e teores de amido às fatias de mandioquinha-salsa em comparação com as outras atmosferas. Conclui-se que a atmosfera modificada passiva, aliada à refrigeração e a boas práticas de fabricação, é suficiente

  18. Análise de Sistemas de Geração de Energia Elétrica com Base na Pegada Ecológica Modificada

    Directory of Open Access Journals (Sweden)

    Bruno Silva de Carvalho

    2011-08-01

    Full Text Available O presente trabalho determina a Pegada Ecológica modificada e a Capacidade de Carga (Zhao et al., 2004 de três sistemas de geração de energia elétrica com uso de combustíveis renováveis e as compara. Foram estudados os sistemas de Utilização de Resíduos Sólidos Urbanos em um Aterro Sanitário na cidade de São Paulo (Frimaio, 2011, Estação de Tratamento de Efluentes na cidade de Uppsala na Suécia (Bjorklund, et al., 2001 e uma Usina Autônoma localizada em São Paulo (Silva, 2006. Os resultados obtidos apontam que o sistema de Aproveitamento de resíduos apresenta melhor performance com relação ao sistema de Estação de Tratamento de Esgoto a Usina Autônoma.

  19. Armazenamento em atmosfera modificada e controlada de banana 'Prata' com absorção de etileno Modified and controlled atmosphere storage of 'Prata' banana with ethylene scrubbing

    Directory of Open Access Journals (Sweden)

    Auri Brackmann

    2006-10-01

    Full Text Available Foram conduzidos dois experimentos com o objetivo de avaliar o efeito da absorção do etileno e de pressões parciais de O2 e CO2 sobre a qualidade da banana 'Prata'. Os tratamentos no experimento 1 foram: AR (armazenamento refrigerado; AR + AE (absorção de etileno; e AM (atmosfera modificada + AE. No experimento 2 os tratamentos foram: AR; AR + AE; AM + AE; 21,0 kPa O2 + 3,0 kPa CO2 + AE; 21,0 kPa O2 + 4,5 kPa CO2 + AE; 21,0 kPa O2 + 6,0 kPa CO2 + RA; 21,0 kPa O2 + 4,5 kPa CO2; e 2,0 kPa O2 + 4,5 kPa CO2 + AE. As temperaturas de armazenamento foram 25ºC e 12ºC para os experimentos 1 e 2, respectivamente. Para o armazenamento em atmosfera modificada foram utilizados filmes de polietileno de baixa densidade, com espessura de 16gama. No experimento 1, a absorção de etileno proporcionou frutos com maior firmeza de polpa e menor escurecimento da casca. A AM+AE proporcionou frutos com cor da epiderme mais verde. No experimento 2, verificou-se que todos tratamentos em atmosfera controlada com absorção de etileno apresentaram cor da casca mais verde e menor escurecimento da casca. A banana 'Prata' pode ser armazenada em atmosfera modificada durante 14 e 21 dias a 25ºC e 12ºC, respectivamente, e por 28 dias em atmosfera controlada a 12ºC, sempre com absorção do etileno.Two experiments were carried out with the objective to evaluate the effect of storage conditions and ethylene scrubbing on the quality of 'Prata' bananas. The treatments of experiment 1 were: cold storage (CS; CS + ES (ethylene scrubbing and MA (modified atmosphere + ES. In experiment 2 treatments were: CS; CS + ES; MA + ES; 21kPa O2 + 3kPa CO2 + ES; 21kPa O2 + 4.5kPa CO2 + ES; 21kPa O2 + 6kPa CO2 + ES; 21kPa O2 + 4.5kPa CO2; and 2kPa O2 + 4.5kPa CO2 + ES. The storage temperatures were 25ºC and 12ºC for the experiments 1 and 2, respectively. In experiment 1, ethylene scrubbing maintained higher flesh firmness and lower skin browning. MA+ES maintained greener peel color. In

  20. Escolecita de aglomerados basálticos del complejo basal de Fuerteventura (Islas Canarias)

    OpenAIRE

    La Iglesia, Á.; Fernández Santín, Soledad; Hernández-Pacheco, A.

    1990-01-01

    Se caracteriza por análisis químico, microscopía óptica, difracción de Rayos X, análisis térmico diferencial, termogravimetría y espectroscopía de infrarrojos, una zeolita fibrosa perteneciente a la formación volcánica aglomerática del Complejo Basal de la isla de Fuerteventura. Los datos analíticos obtenidos confirman la identidad de esta zeolita fibrosa como escolecita. El análisis químico del mineral pone de manifiesto un elevado contenido en sodio, superior a los que aparecen en la biblio...

  1. Evaluación de las propiedades mecánicas de una mezcla densa en caliente modificada con un desecho de polietileno de baja densidad (PEBD Mechanical properties evaluation of a dense hot asphalt mixture modified with a residue of low density polyethylene (LDPE

    Directory of Open Access Journals (Sweden)

    Hugo Rondón Quintana

    2010-04-01

    Full Text Available El artículo presenta los resultados experimentales de ensayar una mezcla asfáltica densa en caliente tipo MDC-2 (acorde con las especificaciones del Instituto Nacional de Vías - INVIAS, 2007 modificada con un desecho de polietileno de baja densidad (PEBD. Para la evaluación del comportamiento de las mezclas asfálticas convencionales (sin aditivo y modificadas se realizaron ensayos Marshall, módulo dinámico, deformación permanente y resistencia a fatiga. Las mezclas fueron elaboradas con un cemento asfáltico (CA producido en Colombia tipo CA 80-100. Al CA con y sin aditivo se realizaron ensayos de caracterización de asfaltos como penetración y punto de ablandamiento. La modificación de las mezclas se realizó por vía húmeda. Las mezclas modificadas con desecho de PEBD experimentan mayor rigidez (bajo carga monotónica y cíclica y resistencia a la deformación permanente en comparación con las convencionales. Sin embargo la resistencia a fatiga de las mezclas convencionales disminuye cuando se adiciona PEBD al CA. Adicionalmente el CA modificado presenta mayor resistencia a la penetración, mayor punto de ablandamiento y menor susceptibilidad térmica a fluir que el convencional.Laboratory tests were used to evaluate the effect on the mechanical properties of a hot asphalt mix (MDC-2 as per INVIAS, 2007 specifications due to the addition by wet way of a residue of low density polyethylene (LDPE. The strength under monotonic load, resilient modulus, rutting and fatigue strength were evaluated. Asphalt cement (AC AC 80-100 was used from Colombia. The results show that the monotonic and cyclic mechanical strength evaluated were higher for the mixes modified with LDPE compared with mixtures with asphalts without additives. However, the mixes modified with LDPE undergo less fatigue strength. Additionally, characterization tests were conducted on asphalt cement with and without additive. The LDPE produces higher penetration resistance

  2. Tratamiento de la incontinencia urinaria de esfuerzo en la mujer, por la técnica de Perrin modificada

    Directory of Open Access Journals (Sweden)

    Edilberto Borges Cárdenas

    1995-12-01

    Full Text Available Se realizó un estudio prospectivo en 21 mujeres que presentaron incontinencia urinaria de esfuerzo, las cuales recibieron tratamiento quirúrgico por la técnica de Perrin modificada, en el Hospital General Docente "Guillermo Domínguez", del municipio Puerto Padre, en los años 1990 y 1991. Estas pacientes se siguieron después de operadas por espacio de 1 año, para evaluar los resultados mediatos obtenidos al aplicar esta técnica. Como principales resultados y conclusiones se expresan: la incontinencia urinaria de esfuerzo fue más frecuente después de la cuarta década de la vida, estuvo relacionada con la multiparidad y con el tipo de parto transpelviano; se encontró asociada con diversos grados de relajación pelviana, y resultaron los ligeros y medianos esfuerzos los que con mayor frecuencia la provocaron. Las pruebas de esfuerzo presentaron un alto grado de positividad. Técnicas quirúrgicas fallidas por vía vaginal, se recogieron como un antecedente importante. La retención urinaria fue la complicación posoperatoria más frecuente. El 95 % de los resultados mediatos alcanzados se evaluaron de satisfactorios

  3. Diseño y construcción de bobinas de Rogowski modificadas de bajo costo y alto desempeño

    Directory of Open Access Journals (Sweden)

    Diego Seuret Jiménez

    2014-01-01

    Full Text Available Las bobinas Rogowski son dispositivos sencillos, confiables y versátiles para hacer mediciones de corriente en una amplia gama de aplicaciones que van, desde dispositivos microelectrónicos hasta sistemas de alta potencia en instalaciones industriales. Se construyó una bobina de Rogowski y el circuito de acondicionamiento de la señal para poder hacer mediciones de su respuesta ante estímulos eléctricos y llevar a cabo un análisis cualitativo. Adicionalmente, a partir del modelo matemático de la bobina, se hizo una modificación en la estructura interna de la misma para obtener voltajes de mayor magnitud y facilitar la lectura en instrumentos de medición eléctrica. Estos resultados se compararon con una bobina comercial estándar y las mediciones del voltaje de salida de la bobina Rogowski modificada muestran una señal con menos ruido y de mayor magnitud. Al haber aumentado la relación señal ruido en el sistema, el circuito de integración y amplificación arrojan resultados esperados.

  4. Conservação pós-colheita de melão Charentais tratado com 1-MCP e armazenado sob refrigeração e atmosfera modificada Postharvest conservation of charentais melons treated with 1-MCP and stored under refrigeration and modified atmosphere

    Directory of Open Access Journals (Sweden)

    Pahlevi A de Souza

    2008-12-01

    Full Text Available Objetivando avaliar a vida útil pós-colheita de melão tipo Charentais (Cucumis melo L. sob refrigeração, tratados com 1-MCP e associado ou não a atmosfera modificada (AM, foram conduzidos dois experimentos em laboratório da Embrapa Agroindústria Tropical, Fortaleza-CE. Os frutos foram provenientes da Agroindústria Nolem Comercial Importadora e Exportadora Ltda, localizada no Agropólo Mossoró Açu-RN. Os frutos foram tratados com 300 e 600 ppb de 1-MCP, em seguida, metade desses frutos foram embalados em filmes plásticos, mantendo-se frutos embalados sem aplicação de 1-MCP nas mesmas condições de armazenamento dos demais. Os melões foram armazenados por 21 dias sendo 14 dias (9±1ºC e 87±5% UR + 7 dias (22±2ºC e 70±5% UR. Em função da aparência externa, a vida útil pós-colheita dos frutos armazenados sob atmosfera modificada, com ou sem tratamento inicial de 1-MCP foi de 21 dias, enquanto que dos frutos tratados inicialmente apenas com 1-MCP foi de 19 dias. A aplicação do 1-MCP proporcionou redução na atividade respiratória e na produção de etileno, e maior retenção da firmeza da polpa, menor perda de massa e melhor aparência externa quando associado a atmosfera modificada. A atmosfera modificada, isoladamente, foi eficiente em reduzir a perda de massa e manter melhor aparência externa.Aiming to evaluate the postharvest shelf life of Charentais melon (Cucumis melo L. stored under refrigeration, the fruits were treated with 1-MCP, associated or not with modified atmosphere (MAP. Two experiments were carried out at the laboratory of Embrapa Agroindústria Tropical in Fortaleza, Brazil, analyzing the chemical and physic quality characteristics. The fruits were obtained at the Agroindústria Nolem Comercial Importadora e Exportadora Ltda, located in Mossoró Açu, Brazil. The fruits were treated with 300 and 600 nL L-1 of 1-MCP, half of those were wrapped in plastic films, which were wrapped without the use of 1

  5. Utilização de zeólitas modificadas CaX e MgX como adsorventes de compostos orgânicos

    Directory of Open Access Journals (Sweden)

    Denise Maria Malachini Miotto

    2002-04-01

    Full Text Available Neste trabalho, foi avaliada a capacidade de adsorção de zeólitas modificadas, CaX e MgX, em contato com uma solução do subproduto do processo de extração de esteviosídeo, um adoçante extraído das folhas de Stevia rebaudiana. Os efeitos do processo de adsorção na estrutura zeolítica foram avaliados por meio de diversas técnicas de caracterização. As análises térmicas mostraram que os compostos adsorvidos sofrem pequenas mudanças estruturais sob aquecimento. A partir da espectroscopia ao infravermelho, foi verificado que o processo de adsorção não modifica a estrutura da zeólita. As medidas de área superficial e volume de poros indicaram que a adsorção ocorre preferencialmente na superfície externa e nos mesoporos. Finalmente, os resultados de acidez indicaram que a adsorção dos compostos orgânicos coloridos ocorre principalmente nos cátions de compensação.

  6. Sorption of Cs-137 and Co-60 in Natural Zeolites; Sorcion de Cs-137 y Co-60 en zeolitas naturales

    Energy Technology Data Exchange (ETDEWEB)

    Chales Suarez, G; Moreno Alvarez, D; Coutin Correa, D [Agencia de Energia Nuclear, La Habana (Cuba)

    1996-07-01

    The sorption of Cs-137 and Co-60 in natural zeolites under different conditions was studied. The behaviour of samples of mineral and rock from different deposit of the country was obtained and the decontamination of radioactive waters containing both radionuclides was performed; as part of the research to determine its application in the treatment of radioactive wastes in the country.

  7. El sistema de calificación cualitativa para la Prueba Gestáltica de Bender – Modificada. Estudio preliminar de sus propiedades psicométricas

    Directory of Open Access Journals (Sweden)

    César A. Merino Soto

    2010-01-01

    Full Text Available El presente artículo describe las propiedades psicométricaspreliminares del Sistema de CalificaciónCualitativa para la Prueba Gestáltica de Bender– Modificada, en un grupo de 97 niños que van a ingresar al primer grado de educación elemental en una escuela pública de Lima. Los niveles deconfiabilidad por consistencia interna y test-retestfueron más modestos que los del manual, aunque su rango potencial (por intervalos de confianzallega a niveles altos. La correlación con criterios de conducta orientada a la tarea, inteligencia fluida y el reporte parental de conductas de motricidad fina dan soporte a la validez y utilidad de este nuevo sistema en el contexto de la evaluación de niños de primer grado. Se discute su relevancia para la evaluación psicopedagógica y para la investigación educacional.

  8. Obtaining of iron particles of nanometer size in a natural zeolite; Obtencion de particulas de hierro de tamano nanometrico en una zeolita natural

    Energy Technology Data Exchange (ETDEWEB)

    Xingu C, E. G.

    2013-07-01

    The zeolites are aluminosilicates with cavities that can act as molecular sieve. Their crystalline structure is formed by tetrahedrons that get together giving place to a three-dimensional net, in which each oxygen is shared by two silicon atoms, being this way part of the tecto silicate minerals, its external and internal areas reach the hundred square meters for gram, they are located in a natural way in a large part of earth crust and also exist in a synthetic way. In Mexico there are different locations of zeolitic material whose important component is the clinoptilolite. In this work the results of three zeolitic materials coming from San Luis Potosi are shown, the samples were milled and sieved for its initial characterization, to know its chemical composition, crystalline phases, morphology, topology and thermal behavior before and after its homo-ionization with sodium chloride, its use as support of iron particles of nanometer size. The description of the synthesis of iron particles of nanometer size is also presented, as well as the comparison with the particles of nanometer size synthesized without support after its characterization. The characterization techniques used during the experimental work were: Scanning electron microscopy, X-ray diffraction, Infrared spectroscopy, specific area by means of BET and thermogravimetry analysis. (Author)

  9. Armazenamento de pitangas sob atmosfera modificada e refrigeração: II - qualidade e conservação pós-colheita Storage of Suriname cherry under modified atmosphere and refrigeration: quality and postharvest conservation

    Directory of Open Access Journals (Sweden)

    Adriana Ferreira dos Santos

    2006-04-01

    Full Text Available Este trabalho teve como objetivo avaliar o efeito de atmosfera modificada (AM na conservação pós-colheita de pitangas colhidas nos estádios de maturação e início da pigmentação (IP, vermelho-alaranjado (VA e vermelho predominante (VP e armazenadas a 10 e a 14 ºC (90 ± 1%UR e condições ambientes (23± 2 ºC e 85 ± 2%UR. O uso de AM associada à refrigeração resultou em menores perdas de massa, incidência de fungo e enrugamento. A AM também permitiu um aumento de quatro dias na vida útil pós-colheita, mantendo a qualidade acima do limite de aceitação durante oito dias, para pitangas do estádio VA mantidas sob refrigeração. Em conjunto, pitangas colhidas no estádio de maturação vermelho-alaranjado apresentaram melhor potencial de armazenamento, quando mantidas sob atmosfera modificada a 10 ºC.The aim of this work was to evaluate the effect of modified atmosphere (MA on postharvest conservation of Suriname cherry harvested in the maturity stages: pigment initiation (PI, red-orangish (RO and predominant red (PR, and stored at 10, 14 ºC (90 ± 1% RH, and room temperature (23± 2 ºC and 85 ± 2% RH. The use of MA associated with refrigeration resulted in lower mass loss, fungi incidence, and fruit shrinkage. The MA also allowed a four-day increase in postharvest life, maintaining the general quality above acceptance limit during eight days, for Suriname cherries of RO maturity stage, kept under refrigeration. Collectively, Suriname cherries harvested at the maturity stage red-orangish presented the best storage potential, when kept under modified atmosphere at 10 ºC.

  10. Efecto de una película plástica modificada en algunos aspectos bioquímicos de un cultivo de tomate (Solanum lycopersicum L. / Effect of a modified plastic film on some biochemical aspects of a tomato (Solanum lycopersicum L. crop

    Directory of Open Access Journals (Sweden)

    Ema Laura García-Enciso

    2014-04-01

    Full Text Available El objetivo del presente estudio fue conocer el efecto de una cubierta para invernadero modificada con nanopartículas y pigmentos fluorescentes, la cual se nombró CIQA, sobre el rendimiento, y algunas variables bioquímicas y la calidad de frutos de tomate. El trabajo se realizó en el Centro de Investigación en Química Aplicada ubicado en Saltillo, Coahuila. Se instalaron dos invernaderos, en uno se usó la cubierta convencional y en el otro la película modificada. Se midió la Radiación Fotosintéticamente Activa (PAR y la temperatura al interior y exterior de los invernaderos. Se estableció un cultivo de tomate en los invernaderos, se determinó el contenido de clorofilas y carotenoides en las plantas y en los frutos se evaluó el contenido de Vitamina C y licopeno. Las lecturas máximas de PAR fueron mayores en el exterior, luego en el invernadero convencional y por último en el invernadero CIQA. En cuanto a temperatura, las lecturas más altas se presentaron en el invernadero de plástico convencional, seguido por el invernadero con la película CIQA y el exterior. Se encontraron diferencias durante algunos muestreos para el contenido de carotenoides, Vitamina C y licopeno. Lo anterior permite concluir que la película plástica CIQA disminuye la radiación y la temperatura al interior del invernadero, sin afectar los estándares de calidad de los frutos y el rendimiento del cultivo.

  11. Envasado de Carne de Vacuno con Hueso y Grasa en Atmósfera Modificada con CO2 y CO Packaging of Bone and Fat Containing Beef Meat under a Modified Atmosphere Containing CO2 and CO

    OpenAIRE

    Estrella R Aspé; Marlene D Roeckel; Cristina Martí; Romel Jiménez

    2008-01-01

    Se evaluó el efecto de envasado en atmósfera modificada (MAP) con bajo contenido de CO (0.1% y 0.4%) y presencia de CO2 sobre el color rojo y la vida útil de carne de vacuno. Se determinaron características microbiológicas, fisicoquímicas, organolépticas-sensoriales y de color del músculo y se compararon los resultados con el MAP de 70%O2+30%CO2. La vida útil de las muestras con O2 fue de 30 días mientras que para las muestras en MAP la vida útil fue de 40 a 45 días y no dependió de la concen...

  12. Aumento da vida útil e microbiologia da carne suína embalada em atmosfera modificada Shelf life extension and microbiology of pork meat packaged in modified atmosphere

    Directory of Open Access Journals (Sweden)

    Sérgio Borges Mano

    2002-01-01

    Full Text Available Com o objetivo de avaliar o efeito da embalagem de carne suína em atmosfera modificada, obteve-se assepticamente amostras de lombo (Longissimus dorsi de suíno de aproximadamente 3x3cm que depois de lavadas em solução salina (0,35% estéril, foram introduzidas em bolsas de plástico (Cryovac BB4L de baixa permeabilidade. Dividiram-se em 4 lotes e se embalaram com aproximadamente 1,0l de ar (100%, nitrogênio (100%, 20/80 e 40/60 CO2/O2 e se termo-selaram. Finalmente, cada lote se subdividiu em 2, armazenando-se a 1 e 7ºC. Durante o armazenamento tomaram-se amostras determinando-se a composição da atmosfera, o pH e a composição da microbiota (microbiota total, bactérias lácticas, Enterobacteriaceae, Brochothrix thermosphacta e contagens em ágar pseudomonas. Os parâmetros de crescimento (fase de latência e tempo de duplicação dos microrganismos foram determinados mediante a equação de Gompertz. Os resultados demonstraram que a vida útil da carne suína é prolongada quando se armazena em atmosferas modificadas. As atmosferas enriquecidas com CO2 e a 1ºC mostraram uma maior eficácia. As atmosferas com CO2, mantiveram o pH das amostras constante durante todo o período de armazenamento. A 1 e 7ºC, as fases de latência e os tempos de duplicação da microbiota total foram progressivamente maiores na seguinte ordem: atmosfera de ar (100%, N2 (100%, 20/80 e 40/60 CO2/O2. Pode-se concluir que, tanto a 1 como a 7ºC, a utilização das atmosferas modificadas retardou o crescimento das bactérias alterantes da carne suína, favorecendo o prolongamento da vida útil, principalmente nas atmosferas com CO2.The objective of the present study was to evaluate the effect of modified atmospheres on refrigerated pork meat (Longissimus dorsi. Pork meat was cut into ca. 1cm thick slices of 9cm², introduced in Cryovac type BB4L bags, characterized by its low gas permeability, and divided into four batches. The bags of each batch were filled

  13. Fas2-ELISA y la técnica de sedimentación rápida modificada por lumbreras en el diagnóstico de la infección por Fasciola hepática

    Directory of Open Access Journals (Sweden)

    Vicente Maco Flores

    2002-04-01

    Full Text Available La fasciolosis humana es un problema de salud pública debido a la mayor incidencia de casos reportados en los últimos años alrededor del mundo. La necesidad de contar con técnicas o métodos de diagnóstico para Fasciola hepatica de mayor sensibilidad y especificidad es importante tanto para la práctica clínica como para determinar zonas endémicas. Objetivo: Evaluar las técnicas coprológicas y serológicas para el diagnóstico de la infección por Fasciola hepatica en humanos. Material y métodos: La población de estudio comprendió a niños en edad escolar entre 1-16 años de edad, pertenecientes a una zona de alta endemicidad (Junin, Perú. Se obtuvieron un total de 194 muestras de heces y 158 muestras de suero. Se evaluaron tres métodos coproparasitológicos: Método de Concentración éter-formol (MCEF, Técnica de Sedimentación Espontánea (TSE y la Técnica de Sedimentación Rápida (TSR modificada por Lumbreras, y tres métodos serológicos: Arco 2, Western blot para F. hepatica y Fas2-ELISA. Resultados: La TSR modificada por Lumbreras fue la de mayor rendimiento (20.61% en comparación con la TSE (13.40% y MCEF (7.72%. La sensibilidad de Fas2-ELISA fue de 96.77% superior a la del Western blot y Arco 2, con sensibilidades de 71.87% y 35.48%, respectivamente. Conclusiones: La TSR es superior a TSE y MCEF para el diagnóstico de la fasciolosis humana en la fase crónica. Fas2-ELISA, es una prueba de inmunodiagnóstico altamente sensible y que se propone debe ser usada como la prueba de diagnóstico de fasciolosis humana y de tamizaje de la infección en poblaciones humanas que habitan en regiones de alta endemicidad para esta parasitosis.

  14. Osteotomia em Chevron modificada: análise preliminar do comportamento baropodométrico Modified Chevron osteotomy: preliminary analysis of baropodometric behavior

    Directory of Open Access Journals (Sweden)

    Juliana Motta Costa

    2010-01-01

    Full Text Available OBJETIVO: Avaliar as características clínicas e baropodométricas da marcha de indivíduos com Hálux Valgo após a osteotomia em Chevron modificada, isolada ou em associação com a osteotomia de Weil. MÉTODOS: FORAM avaliados, antes e três meses após a cirurgia, 27 pés com deformidade leve e moderada. A avaliação clínica incluiu a pontuação da AOFAS e medidas radiográficas. A avaliação baropodométrica foi realizada através da Plataforma Emed-at. As variáveis Pico de Pressão, Integral Pressão-Tempo e Carga Relativa foram calculadas em 10 regiões: calcanhar, mediopé, 1-5º metatársicos, hálux, 2º, 3-5º dedos. RESULTADOS: Após a cirurgia houve aumento na pontuação da AOFAS e redução dos parâmetros radiográficos. A avaliação baropodométrica, após osteotomia em Chevron isolada, demonstrou redução da pressão e da força sob o 1º metatársico e hálux, assim como, aumento dessas variáveis nos metatársicos centrais e laterais. Após a osteotomia em Chevron/Weil ocorreram alterações significativas apenas na região do hálux e dos dedos. CONCLUSÃO: Em curto prazo, a técnica em Chevron modificada promoveu melhora das condições clínicas e dos parâmetros radiográficos. Em relação a avaliação baropodométrica constatou-se uma transferência de cargas da região medial para lateral do antepé, possivelmente pelo curto período de pós-operatório.OBJECTIVE: To evaluate the clinical and baropodometric characteristics of the gaits of individuals with a hallux valgus deformity after modified Chevron osteotomy, in isolation or in association with the Weil osteotomy. METHODS: Foot evaluation happened before and three months after surgery analyzing 27 mildly and moderately deformed feet. The clinical evaluation included the AOFAS score and radiographic measurements. The baropodometric evaluation was done with the Emed-at platform. Peak of Pressure, Pressure-Time Integral and Relative Load were calculated in

  15. Influência da embalagem de atmosfera modificada e do tratamento com cálcio na cinética de degradação de ácido ascórbico e perda de massa em goiabas (Psidium guajava L.

    Directory of Open Access Journals (Sweden)

    YAMASHITA Fábio

    2000-01-01

    Full Text Available Goiabas de mesa (var. Pedro Sato no estádio verde maturo foram armazenadas a 8°C (85-95% UR por 49 dias. Uma parte das amostras foi tratada com solução de cloreto de cálcio 2% (p/v e o restante permaneceu sem tratamento. Posteriormente, foram embaladas individualmente em dois tipos de embalagem de atmosfera modificada (CryovacÒ PD-900 e CryovacÒ PD-961. Goiabas sem embalagem e não tratadas com cálcio, mantidas à mesma temperatura de 8°C serviram como controle. Foram realizadas análises de perda de massa, acidez titulável, teores de sólidos solúveis totais e ácido ascórbico. Os frutos embalados apresentaram taxas de perda de massa menores que os sem embalagem (p<0,05. Os frutos tratados com cálcio não apresentaram diferença na taxa de degradação de ácido ascórbico em relação aos não tratados e os frutos embalados com PD-900 apresentaram retenção de ácido ascórbico maior. Após 4 semanas, as goiabas sem embalagem apresentaram-se impróprias para consumo, devido ao murchamento e ataque de fungos, enquanto que as embaladas estavam em bom estado. Após a sexta semana, apenas os frutos embalados com PD-900 sem tratamento com cálcio estavam próprios para consumo. A embalagem de atmosfera modificada reduziu a perda de massa e ácido ascórbico e prolongou a vida-de-prateleira do produto. O emprego de cálcio não afetou as características analisadas.

  16. Preparação de fibras de polipropileno modificadas com grupos mercaptan e sua utilização em compósitos com resina epoxídica

    Directory of Open Access Journals (Sweden)

    Dutra Rita C. L.

    1999-01-01

    Full Text Available Fibras de polipropileno modificadas com grupos mercaptan foram desenvolvidas através de processo de extrusão/fiação de misturas contendo PP e EVA modificado com grupos mercaptan (EVASH. A superfície destas fibras foi analisada por espectroscopia foto-eletrônica de raios-X (XPS, espectroscopia no infravermelho com transformada de Fourier, utilizando-se a técnica de refletância difusa (DRIFTS, tensão superficial e microscopia eletrônica de varredura. A partir destas técnicas, chegou-se à conclusão que o componente polar (EVASH se situa próximo à superfície da fibra. A utilização destas fibras em compósitos com resina epoxídica resultou em aumento considerável da resistência ao impacto e da temperatura de transição vítrea do material, indicando boa adesão interfacial matriz-fibra. Estas interações foram comprovadas por análise dinâmico-mecânicas.

  17. Hydrothermal Synthesis of Zeolite from Coal Class F Fly Ash. Influence of Temperature

    Directory of Open Access Journals (Sweden)

    Goñi, S.

    2010-06-01

    Full Text Available The influence of temperature of alkaline hydrothermal treatment on the conversion in zeolite of Spanish coal low calcium-fly ash (ASTM class F is presented in this work. Zeolite Na-P1 gismondine type (Na6Al6Si10O32.12H2O was formed at the temperature of 100ºC, which transformed in zeolite; analcime-C type (Na(Si2AlO6H2O and sodalite (1.08 Na2O.Al2O3.1.68SiO2.1.8H2O at 200ºC together with traces of tobermorite-11Å (Ca5(OH2Si6O16.4H2O. At this temperature the 100% of the fly ash reaction was allowed. An equivalent study was carried out in water as reference. The zeolite conversion of the fly ash was characterized by X ray diffraction (XRD, FT infrared (FTIR spectroscopy, surface area (BET-N2 and thermal analyses.

    En este trabajo se presenta el papel que juega la temperatura durante el tratamiento hidrotermal en medio alcalino para convertir una ceniza volante de bajo contenido en cal (clase F, según la norma ASTM en zeolita. Durante este tratamiento a la temperatura de 100ºC se forma Zeolita Na-P1 tipo gismondina (Na6Al6Si10O32.12H2O; al elevar la temperatura a 200ºC, dicha zeolita se transforma en zeolita Analcima C (Na(Si2AlO6H2O y en fase sodalita (1.08 Na2O.Al2O3.1.68SiO2.1.8H2O junto con trazas de tobermorita-11Å (Ca5(OH2Si6O16.4H2O. A esta temperatura y en estas condiciones se ha conseguido un 100% de reacción. Un estudio equivalente se ha llevado a cabo empleando agua como medio de referencia. La conversión de ceniza volante en zeolita se ha caracterizado mediante técnicas, como difracción de Rayos X (DRX, espectroscopia

  18. Atmosfera modificada e controle de etileno para bananas 'Prata-Anã' cultivadas na Amazônia Setentrional Brasileira

    Directory of Open Access Journals (Sweden)

    Marcos André de Souza Prill

    2012-12-01

    Full Text Available O presente trabalho teve por objetivo avaliar o efeito da atmosfera modificada (AM pelo uso de embalagem plástica de polietileno de baixa densidade (PEBD, do vácuo e da adsorção de etileno, visando à manutenção da qualidade das bananas 'Prata-Anã' produzidas em Roraima. As análises foram realizadas em intervalos de 5 dias após a colheita, até 35 dias de armazenamento refrigerado (AR. Verificou-se que os frutos submetidos a embalagem de PEBD apresentaram as menores perdas de massa fresca quando comparados aos demais. Da mesma forma, os frutos embalados na presença do adsorvedor de etileno obtiveram a melhor manutenção na coloração da casca, atraso temporal, do pico climatérico, assim como o retardamento na degradação do amido, os menores incrementos de sólidos solúveis e acidez titulável, as menores concentrações de etileno nos interiores das embalagens e atraso temporal e a diminuição da atividade enzimática. Isso, possivelmente, proporcionou os maiores teores de pectina total e solúvel ao final do período experimental. A combinação do uso da embalagem de PEBD com o sachê de permanganato de potássio (KMnO4 resultou no retardamento do processo de maturação dos frutos de banana 'Prata-Anã', quando armazenada a 12 ºC. Pode-se atribuir esse efeito benéfico à presença do sachê na adsorção de etileno e, consequentemente, na ação do etileno no amadurecimento dos frutos, retardando a senescência das bananas 'Prata-Anã'.

  19. Preparação de argila modificada com cloreto de cetilpiridíneo e avaliação da interação desta com o PVC Preparation of modified clay with cetylpyridinium chloride and evaluation of their interaction with PVC

    Directory of Open Access Journals (Sweden)

    Daniel K. Resende

    2010-09-01

    Full Text Available Foi preparada uma argila modificada com cloreto de cetilpiridíneo a partir da argila sódica por troca de cátions em solução. Foi avaliada a quantidade de agente de modificação em relação à argila sódica e o tempo reacional. Os materiais obtidos foram caracterizados por difração de raio X (XRD, análise termogravimétrica (TGA e ressonância magnética nuclear (RMN de baixo campo. Após a caracterização foi confirmada a modificação da argila e, também, foi verificado que o produto obtido pode ser empregado na preparação de nanocompósitos de PVC, considerando que o início da degradação do material preparado ocorreu em temperatura superior às comumente utilizadas no processamento do polímero. A adição da argila modificada apresentou uma dispersão adequada no PVC e manteve o início da degradação do material em temperatura compatível com o processamento do polímero, gerando um nanocompósito com parte esfoliada e intercalada.A modified silicate with cetylpyridinium was prepared from sodium clay with cation exchange in solution. The amount of modification agent for clay and the reaction time were evaluated. The materials produced were characterized using X ray diffraction (XRD, termogravimetric analysis (TGA and low field nuclear magnetic resonance (NMR. The formation of new organic clay was confirmed, which was introduced in PVC for the formation of nanocomposites. The beginning of degradation of the new clay occurred at temperatures higher than commonly used in the processing of PVC. The nanocomposites were partially exfoliated and partially intercalated.

  20. Armazenamento de pitanga sob atmosfera modificada e refrigeração: I-transformações químicas em pós-colheita Storage of Suriname cherry under modified atmosphere and refrigeration: I - postharvest chemical changes

    Directory of Open Access Journals (Sweden)

    Adriana Ferreira dos Santos

    2006-04-01

    Full Text Available Este experimento teve como objetivo avaliar as transformações pós-colheita em pitangas colhidas nos estádios de maturação vermelho-alaranjado (VA e vermelho predominante (VP e mantidas sob atmosfera modificada (AM por filme de cloreto de polivinila (PVC, a 10 ± 0,5 ºC, 14 ± 0,5ºC e (90 ± 1%UR e a temperatura ambiente (23 ± 2°C e 85 ± 2%UR. O uso de AM associada à refrigeração permitiu manutenção dos sólidos solúveis, acidez titulável, dos açúcares solúveis totais e vitamina C, e também resultou em menor taxa de aumento nos carotenóides totais para frutos do estádio de maturação VA mantido a 10 e 14ºC. Em conjunto, pitangas colhidas no estádio vermelho-alaranjado foram as que apresentaram melhor manutenção das características intrínsecas durante oito dias de armazenamento sob atmosfera modificada a 10ºC.The aim of this experiment was to evaluate postharvest changes in Suriname Cherry harvested in the maturity stages red-orangish (RO and predominant red (PR, kept under modified atmosphere (MA by polyvinyl chloride film (PVC, at 10± 0.5 ºC, 14± 0.5 ºC, 90 ± 1% RH and room temperature (23 ± 2°C. The use of MA associated with refrigeration allowed the maintenance of total soluble solids, titratable acidity, soluble sugars, and vitamin C, and also resulted in lower increase rate in total carotenoids for fruits in the RO maturity stages kept at 10 e 14ºC. All together, Suriname Cherries harvested in red-orangish skin color were those that presented better maintenance of the intrinsic characteristics during 8 days storage under modified atmosphere at 10ºC.

  1. Avaliação do uso da Escala Modificada de Borg na crise asmática Evaluación del uso de la Escala Modificada de Borg en la crisis de asma Evaluation of the use of the Modified Scale of Borg in the asthmatic crisis

    Directory of Open Access Journals (Sweden)

    Tatiane G. de Liz Cavallazzi

    2005-03-01

    Full Text Available A dispnéia é a maior causa de incapacidade e redução da qualidade de vida para pacientes com doenças respiratórias como é o caso da asma. Os objetivos deste estudo foram verificar o grau de dispnéia dos pacientes em crise asmática pela Escala Modificada de Borg e a correlação da melhora do grau de dispnéia com a melhora da função pulmonar verificada pelo Pico de Fluxo Expiratório (PFE. Foram incluídos 40 pacientes asmáticos em crise aguda, atendidos no serviço de Pronto Atendimento em Pneumologia do Hospital São Paulo, no período de setembro à dezembro de 2003. Antes e após o tratamento, os seguintes dados foram coletados: freqüência cardíaca (FC, freqüência respiratória (FR, PFE e saturação periférica de oxigênio (SpO2. O paciente era questionado sobre sua percepção da dispnéia pela Escala Modificada de Borg. No pré-tratamento ocorreu uma tendência dos valores altos da escala de Borg estarem relacionados aos valores baixos do PFE, invertendo esta relação no pós-tratamento. Esta escala é rápida, barata e de fácil aplicabilidade na avaliação de pacientes asmáticos. Pode ser utilizada por profissionais de saúde para a avaliação inicial dos pacientes em crise, bem como sua resposta ao tratamento.La disnea es probablemente, el factor aislado más importante en la limitación de la capacidad de pacientes con asma para el desempeño de las funciones básicas del dia a dia. En consecuencia da esse sintoma, esos pacientes procuran con frecuencia, los servicios de atención de salud. Considerando la necesidad de uma evaluación acurada de ese síntoma, este estudio tuvo como objetivos: evaluar el grado de dísnea de pacientes en crisis de asma, utilizando la escala modificada de Borg y verificar la correlación entre la majoria del grado de dísnea y la mejoria de la función pulmonar, verificada por el Pico de Flujo Expiratorio (PFE y la saturación de oxígeno (SpO2 . Participaron del estudio 40

  2. A operação de Norwood modificada para tratamento da síndrome de hipoplasia do coração esquerdo Modified Norwood procedure for hypoplastic left heart syndrome

    Directory of Open Access Journals (Sweden)

    Fernando A. Fantini

    2004-03-01

    Full Text Available OBJETIVO: Apresentar os resultados do tratamento da síndrome de hipoplasia do coração esquerdo (SHCE com técnica de Norwood modificada, na qual somente são usados tecidos autólogos para a reconstrução do arco aórtico. MÉTODO: De janeiro a dezembro de 2002, cinco recém-nascidos com idade variando de dois a nove dias (média 5,0 dias foram submetidos a operação de Norwood modificada. O diâmetro da aorta ascendente variou de 5 a 8 mm (média 6,2 mm. Foi empregada técnica na qual o arco aórtico e seus ramos foram amplamente dissecados, permitindo a reconstrução de um novo arco aórtico tendo a artéria pulmonar como via de saída, e com a utilização exclusiva de tecidos do próprio paciente. Anastomose sistêmico-pulmonar com politetrafluoretileno expandido de 3,0 mm foi utilizada em três pacientes e de 3,5 mm em dois pacientes. Todos foram operados com parada cardiocirculatória total. RESULTADOS: O tempo de parada cardiocirculatória variou de 41 a 60 minutos (média 52,8 minutos. Todas as crianças sobreviveram ao ato operatório e foram encaminhadas para a unidade de terapia intensiva com o esterno aberto. Ocorreu um óbito no 9: dia de pós-operatório por sepse, o que resultou numa taxa de sobrevivência imediata de 80%. Ocorreu um óbito tardio por pneumonia de aspiração aos dois meses. Uma criança foi submetida ao segundo estágio da operação (cavo pulmonar e encontra-se bem. Duas crianças estão em acompanhamento aguardando o próximo estágio. Em nenhuma delas existem evidências de obstrução do novo arco aórtico. CONCLUSÃO: A técnica de Norwood modificada mostrou-se eficaz e com risco cirúrgico aceitável para o tratamento da SHCE, sem evidências de obstrução do arco aórtico reconstruído.OBJECTIVE: To show current results of a modified Norwood procedure, where only autologous tissues are used in the reconstruction of the new aortic arch. METHOD: Between January and December of 2002, five neonates with

  3. Armazenamento refrigerado sob atmosfera modificada de pedúnculos de cajueiro-anão-precoce dos clones CCP-76, end-157, end-183 e end-189 Storage of cashew apples from dwarf clones CCP-76, end-157, end-183 and end-189 under refrigeration and modified atmosphere

    Directory of Open Access Journals (Sweden)

    Auricélia de Souza Morais

    2002-12-01

    Full Text Available Pedúnculos de clones de cajueiro-anão-precoce, dos clones CCP-76, END-157, END-183 e END-189, foram armazenados durante 25 dias, sob refrigeração associada a atmosfera modificada, com o objetivo de avaliar o efeito das condições atualmente utilizadas (5ºC e 85-90% de UR para conservação, transporte e comercialização de cajus in natura. Os pedúnculos foram avaliados a cada 5 dias quanto às seguintes características: perda de peso, firmeza, cor (antocianinas, sólidos e açúcares solúveis, acidez, pH, vitamina C e compostos fenólicos. O uso da refrigeração (5ºC e 85% U.R, associada a atmosfera modificada, proporcionou uma vida útil pós-colheita de 10 dias para o clone END 189, de até 15 dias para o clone END 157 e de até 25 dias para os clones CCP 76 e END 183. A temperatura de 5ºC não se mostrou adequada para armazenamento de pedúnculos de coloração mais intensa (END 157 e END 189 que a testemunha (CCP 76, provocando perda de cor (antocianinas a partir do 10º dia de armazenamento. A atmosfera modificada reduziu significativamente a perda de peso, favorecendo a aparência do produto para comercialização, independentemente do clone estudado.Apples or false fruits from early dwarf cashew clones CCP-76, END-157, END-183 and END-189 were stored for 25 days under refrigeration associated to modified atmosphere with the aim of evaluating the effect of the conditions presently adopted (5ºC and 85-90% RH for conservation, storage and commercialization of fresh cashew apples. The cashew apples were evaluated every 5 days for the following characteristics: weight loss, pulp firmness, color (anthocyannins, acidity, pH, soluble solids, vitamin C and phenolic contents. With the use of refrigeration and modified atmosphere it was possible to attain postharvest storage life of 10 days for clone END 189, 15 days for clone END 157 and up to 25 days for clones CCP 76 and END 183. It was found that 5ºC was not an adequate

  4. Germinación y crecimiento de Ochroma pyramidale (Cav. ex Lam. Urb. en Ecuador

    Directory of Open Access Journals (Sweden)

    Edwin Jiménez Romero

    2017-01-01

    Full Text Available Se evaluó la germinación y crecimiento de semillas de balsa aplicando siete tratamientos pre-germinativos: inmersión en HSO4 por 32 minutos, inmersión en agua a 80 °C durante tres minutos, testigo, remojo en agua a 100 °C por 15 minutos, remojo en agua de coco 12 horas, lijado de las semillas hasta que pierdan su brillo natural, calor seco 96 °C durante 5 minutos. Sembradas en siete sustratos utilizando tierra negra sola y combinada con: tamo de arroz, arcilla más arena, humus UTEQ, zeolita, arcilla más ceniza, humus nacaro (humus de Lombriz. Se realizó un diseño completamente al azar (DCA en un arreglo factorial 7 (sustratos x 7 (tratamientos pre-germinativos con tres repeticiones y 10 unidades de observación. A los 28 días el factor (sustrato que más influyó en el porcentaje de germinación fue tierra negra más zeolita 7 g/k con 17,75%. El tratamiento pre-germinativo (lijado de las semillas 20,85%. Tierra negra + humus UTEQ 0,70 g k -1 x remojo en agua de coco por 12 horas, alcanzó 133,11 mm de altura de plántula. Tierra negra + humus UTEQ 0,70 g/k con 3,27 mm de espesor del vástago. El mayor número de hojas (cinco se obtuvo en el tratamiento tierra negra + inmersión en HSO4.

  5. Prueba de tolerancia oral a la glucosa modificada en puérperas como diagnóstico retrospectivo de diabetes gestacional

    Directory of Open Access Journals (Sweden)

    Joel Cárdenas

    2004-03-01

    Full Text Available Objetivo: Determinar la relación entre la prueba de tolerancia oral a la glucosa (PTOG en puérperas con macrosomia fetal y plantearla como método de diagnóstico retrospectivo para diabetes gestacional. Diseño de estudio: Estudio clínico, de corte transversal, analítico, casos y controles. Material y Métodos: Estudio de 142 puérperas, 71 con recién nacidos macrosómicos y 71 con recién nacidos con pesos en percentiles de la normalidad. Se realizó una PTOG modificada de dos horas (basal, 1h y 2 h, con 100 g de glucosa, entre las primeras 8 y 48 horas posparto (positivo si [glicemia 2h - basal] + [glicemia 1h - basal] 110 mg/dL. Se utilizó el SPSS 10,0 para crear la base de datos y realizar el análisis estadístico: análisis univariado, bivariado para evaluar la hipótesis, y finalmente un análisis multivariado. Resultados: La PTOG anormal resultó un factor de riesgo para macrosomia fetal, con un odds ratio ajustado de 5,9; IC95% 2,6-13,4. Se encontró asociación entre antecedente de macrosomia fetal, odds ratio 15,7; IC95% 1,9-123,6 y control prenatal odds ratio 5,7; IC95% 1,2-26,8. Conclusión: Existe relación entre la PTOG en puérperas y macrosomia fetal, que puede ser usada como prueba diagnóstica retrospectiva de diabetes gestacional.

  6. Efecto de variedades de algodón genéticamente modificadas sobre larvas de Spodoptera frugiperda Smith (Lepidoptera: Noctuidae

    Directory of Open Access Journals (Sweden)

    Sandra Jimena Valencia Cataño

    2014-01-01

    Full Text Available Spodoptera frugiperda es una plaga polífaga de importancia económica en países tropicales y subtropicales. En Colombia ataca el algodonero (Gossypium hirsutum L., cultivo que ha tomado importancia gracias a la adopción de variedades genéticamente modificadas (GM. En el estudio se determinaron los efectos subletales de algunas de estas variedades sobre larvas de este insecto. Para el efecto, en condiciones de laboratorio (27°C, 65 ± 10% HR y 12 h fotoperiodo se evaluaron las variedades NuOPAL RR (proteína Cry1Ac, DP141 B2RF (proteínas Cry1Ac+Cry2Ab y DeltaOPAL RR (no Bt. Los parámetros evaluados fueron: (a peso de larvas, (bpeso de heces, (c peso del alimento ofrecido y (d peso del alimento no consumido. Como índices de consumo y digestibilidad se calcularon la tasa relativa de consumo (TRCo, la tasa relativa de crecimiento (TRCr, la eficiencia de conversión del alimento ingerido (ECI y la digestibilidad aproximada (DA. Los índices mostraron actividad antialimentaria de la variedad DP141 B2RF (Cry1Ac+Cry2Ab que afecta de forma negativa la tasa de crecimiento y la conversión del alimento por parte de las larvas. El peso de las larvas alimentadas en DP141 B2RF (Cry1Ac+Cry2Ab fue 58.6% menor que en la variedad no Bt. Los resultados muestran un efecto adverso de la variedad DP141 B2RF (Cry1Ac+Cry2Ab en el desarrollo larval de S. frugiperda. Se confirman los efectos antibióticos de las variedades GM evaluadas que inciden en un menor desarrollo y en la supervivencia de las larvas.

  7. Atmosfera modificada e refrigeração para conservação pós-colheita de camu-camu

    Directory of Open Access Journals (Sweden)

    Jacqueline de Oliveirai

    2014-06-01

    Full Text Available O presente trabalho tem por objetivo avaliar a conservação pós-colheita de camu-camu, utilizando a refrigeração e a atmosfera modificada propiciada pelos filmes de policloreto de vinila (PVC e polipropileno biaxialmente orientado de 50µm espessura (BOPP50 e assim avaliar a durabilidade em relação ao controle (sem embalagem. Os frutos foram mantidos a 5±1°C e 90±2% de umidade relativa, durante 25 dias e avaliados a cada quatro dias de armazenamento quanto à firmeza, pH, sólidos solúveis, acidez titulável, ácido ascórbico, antocianinas, perda de massa e concentração de CO2 da atmosfera no interior da embalagem. O filme de BOPP50 mostrou não ser a melhor alternativa para a conservação de camu-camu, pois a sua baixa permeabilidade aos gases ocasionou o acúmulo de CO2 no interior da embalagem, propiciando o processo fermentativo dos frutos após 13 dias de armazenamento. Os atributos pH, sólidos solúveis, acidez titulável, ácido ascórbico e antocianinas não foram afetados pelos tipos de filmes utilizados, mas sim pelos dias de armazenamento. Os resultados mostraram que a utilização do filme de PVC, juntamente com refrigeração, para conservação pós-colheita de camu-camu, foi eficaz na manutenção da firmeza do fruto e na redução de perda de massa, mantendo os frutos comercialmente viáveis por 21 dias, enquanto o controle e os revestidos por BOPP50 se apresentaram inviáveis após 13 dias de armazenamento.

  8. Zeolites modified with silver for the development of a water disinfection system; Zeolitas modificadas con plata para el desarrollo de un sistema de desinfeccion de agua

    Energy Technology Data Exchange (ETDEWEB)

    Aparicio V, S.

    2013-07-01

    In spite of great strides that have been taken in sanitation technologies, there still exist health problems due to microbiological contamination by water. The waterborne diseases have not been completely eradicated and are a big problem of economic interest and health. Moreover, the microbicidal properties of silver have been used for a long time. The use of silver as a disinfectant has many advantages; for example it inhibits a wide spectrum of microorganisms, it has oligo dynamic properties and owing its mechanisms of cell inactivation, it also does not allow the emergence of new resistant strains. In the present research, the kinetics of water disinfection with silver has been investigated, to develop small system for water disinfection, based in silver modified Mexican clinoptilolite. The chemical species of silver play a significant role in the disinfection processes. For this reason, in this work, were both the Ag{sup +} and nanoparticles of Ag{sup ο} considered. The synthesis of nanoparticles of Ag{sup ο} woes performed by thermal and chemical reduction. It was found that the chemical reduction of Ag{sup +} to Ag{sup ο} was more efficient because it presented more defined nano structures and better distribution than those of thermal reduction. Clinoptilolite of Taxco (Guerrero) was chosen to exchange the native ions from the clinoptilolite by Ag{sup +} from the aqueous medium, or to deposit the nanoparticles of Ag{sup ο} on this surface. These silver modified zeolitic materials were characterized by scanning electron microscopy (Sem), elemental analyses (EDS), X-ray diffraction (XRD) and neutron activation analysis (NAA). The results showed that the crystallographic structure of the clinoptilolite did not change during thermal and chemical reduction treatments of Ag{sup +} to obtain the nanoparticles of Ag{sup ο}. The bactericide activity of the silver modified zeolitic materials (with Ag{sup +} or nanoparticles of Ag{sup ο}) was evaluated on Escherichia coli Atcc 8739, in both distilled water and well water. Disinfection kinetic parameters demonstrated that the bactericide efficiency of clinoptilolite with Ag{sup +} (Z Ag-1 and Z Ag-2) was higher than those with nanoparticles of Ag{sup ο} (ZAgNps-1 and ZAgNps-2). The Ag desorbed from Z Ag-1 and Z Ag-2 during the disinfection process was higher than from ZAgNps-1 and ZAgNps-2. Furthermore it was found that the decay rate of E. coli was higher in well water than in distilled water, however the concentration of silver in well water is lower. Experimental data suggested that the bactericide effect and Ag desorption from modified zeolitic materials are determined by the chemical characteristics of the aqueous media, the type of chemical species of Ag and the concentration of Ag{sup +} in the water. The results obtained from this investigation were taken in account to make a proposal of a water disinfection system considering the clinoptilolite with nanoparticles of Ag{sup ο} as the bactericide agent. (Author)

  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. Modified technique to increase nostril cross-sectional area after using rib and septal cartilage graft over alar nasal cartilages Técnica modificada para aumentar a área seccional externa da narina após o uso de enxerto cartilaginoso de costela e septo sob as cartilagens alares nasais

    Directory of Open Access Journals (Sweden)

    Marcelo Wulkan

    2012-10-01

    Full Text Available PURPOSE: Describe a modified technique to increase nostril cross-sectional area using rib and septal cartilage graft over alar nasal cartilages. METHODS: A modified surgical technique was used to obtain, carve and insert cartilage grafts over alar nasal cartilages. This study used standardized pictures and measured 90 cadaveric nostril cross-sectional area using Autocad®; 30 were taken before any procedure and 60 were taken after grafts over lateral crura (30 using costal cartilage and 30 using septal cartilage. Statistical analysis were assessed using a model for repeated measures and ANOVA (Analysis of Variance for the variable "area". RESULTS: There's statistical evidence that rib cartilage graft is more effective than septal cartilage graft. The mean area after the insertion of septal cartilage graft is smaller than the mean area under rib graft treatment (no confidence interval for mean difference contains the zero value and all P-values are below the significance level of 5%. CONCLUSIONS: The technique presented is applicable to increase nostril cross section area in cadavers. This modified technique revealed to enhance more nostril cross section area with costal cartilage graft over lateral crura rather than by septal graft.OBJETIVO: Descrever uma técnica modificada para se aumentar a área seccional externa da narina com cartilagem septal e costal acima das cartilagens alares nasais. MÉTODOS: Utilizou-se uma técnica cirúrgica modificada para obter, esculpir e inserir enxertos de cartilagem sobre as cartilagens alares. Realizou-se fotos padronizadas e mensuração de 90 áreas seccionais externas de narina em cadáveres com Autocad®; 30 antes sem procedimento; 60 após a inclusão de enxertos sob a cruz lateral (30 usando cartilagem costal e 30 usando cartilagem septal. A análise estatística foi feita com um modelo de medidas repetidas e ANOVA para a variável "área" RESULTADOS: Existe evidência estatística de que o enxerto de

  11. Tratamento da espondilólise sintomática com reparo direto pela técnica de Buck modificada Tratamiento de la espondilolisis sintomática con preparo directo por la técnica de Buck modificada Modified Buck's direct repair to simptomatic spondylolysis treatment

    Directory of Open Access Journals (Sweden)

    Bruno Pinto Coelho Fontes

    2009-03-01

    Full Text Available OBJETIVO: justificar a reconstrução da pars interarticularis pela técnica modificada de Buck como método efetivo no tratamento de lombalgia por espondilólise ou espondilolistese tipo 1, refratárias ao tratamento conservador. MÉTODOS: avaliação retrospectiva de oito pacientes com idade entre 11 e 34 anos, operados e acompanhados no período de outubro de 2004 a maio de 2008 com a técnica de Buck utilizando-se parafusos canulados de titânio. Nenhum paciente foi imobilizado no pós-operatório. Os pacientes foram selecionados após serem submetidos a estudos por imagem utilizando radiografias e ressonância magnética. Também foram avaliados no pós-operatório, segundo os critérios de Henderson e quanto à satisfação com o tratamento, assim como o índice de consolidação. RESULTADOS: sete pacientes foram classificados como excelentes, retornando ao nível de prática esportiva e laboral prévia. Dentre eles, um evoluiu com parestesia transitória, com recuperação completa. A oitava paciente apresentou uma pseudartrose bilateral, mas com bom resultado do ponto de vista clínico. Todos os pacientes ficaram satisfeitos com o resultado. CONCLUSÃO: a reconstrução ístmica com parafusos de titânio atingiu excelentes resultados ao aliar biomecânica estável, dissecção mínima da musculatura, com preservação da anatomia e mobilidade do segmento.OBJETIVO: justificar la reconstrucción de la pars interarticularis por la técnica modificada de Buck como método efectivo en el tratamiento de la lumbalgia por espondilosis o espondilolistesis tipo 1, refractarias al tratamiento conservador. MÉTODOS: evaluación retrospectiva de ocho pacientes con edad entre 11 a 34 años, operados y acompañados en el periodo de Octubre de 2004 hasta Mayo de 2008 con la técnica de Buck usando tornillos canulados de titanio. Ningún paciente fue inmovilizado en el postoperatorio. Los pacientes fueron seleccionados después de ser sometidos a

  12. Tratamento cirúrgico videolaparoscópico da doença do refluxo gastroesofagiano: técnica de Nissen modificada - resultados clínicos e funcionais Videolaparoscopic surgical treatment of gastroesophageal reflux disease: modified Nissen technique - clinical and functional results

    Directory of Open Access Journals (Sweden)

    L. R. LOPES

    2001-06-01

    Full Text Available A doença do refluxo gastroesofagiano é muito freqüente na população e o tratamento cirúrgico é indicado em um número respeitável de pacientes. A escolha da via de acesso é a laparoscopia. Várias técnicas anti-refluxo podem ser empregadas e preferimos a técnica de Nissen modificada. OBJETIVO: Analisar os parâmetros clínicos e funcionais pré-operatórios comparados com os mesmos parâmetros pós-operatórios com a técnica empregada. MÉTODOS: Um grupo de 59 pacientes foi submetido a tratamento cirúrgico pela técnica de Nissen modificada videolaparoscópica. O diagnóstico pré-operatório foi feito por exame radiográfico contrastado e endoscopia digestiva alta em todos os pacientes. A manometria do esôfago realizada em 35 e a cintilografia em 15. Esofagite complicada ocorreu em 54,2% sendo 21 pacientes (35,6% com epitélio de Barrett. A técnica cirúrgica laparoscópica foi concluída em todos os pacientes. O tempo médio de cirurgia foi de 123,9 minutos. RESULTADOS: Não ocorreram complicações intra-operatórias. A alta se deu em média com 47,6 horas. Sintomas de disfagia, dor, epigastralgia, regurgitação e flatulência até o 30° dia ocorreram em 48,1% dos pacientes. Ocorreu uma reoperação por recurrência da doença e um óbito por necrose do fundo gástrico. O seguimento médio foi de 20,8 meses. Os exames pós-operatórios radiográficos, endoscópicos, manométricos e de cintilografia mostraram melhora significativa, bem como a avaliação clínica, que mostrou excelentes e bom resultados em 93,1% dos pacientes. CONCLUSÃO: A cirurgia de Nissen modificada videolaparoscópica corrigiu a doença do refluxo gastroesofagiano na maioria dos doentes acompanhados, associada à baixa morbimortalidade.BACKGROUND: Gastroesophageal reflux disease is highly common worldwide and surgical treatment is being indicated more frequently. Currently, laparoscopic is the access of choice and several antireflux techniques may be used

  13. Rumen dry matter degradability of fresh and ensiled sugarcane

    African Journals Online (AJOL)

    my mord

    2013-05-08

    May 8, 2013 ... Brasileira de Zootecnia, Viçosa-MG. pp. 977-985. Ferreira DA, Gonçalves L, Molina LR, Castro-Neto A, Tomich TR. (2007). Fermentation of sugarcane silage treated with urea, zeolita, bacteria inoculant and bacteria/enzymatic inoculants. Arq. Bras. Med. Vet. Zootec. 59:423-433. Garcia H, Abreu M, Soto JM ...

  14. Condições de secagem de uma pasta de anchoita modificada enzimaticamente na oxidação lipídica, lisina disponível e atividade antioxidante do produto Drying conditions of an enzymatic modified paste of anchovy in the lipid oxidation, available lisina and antioxidant activity of the product

    Directory of Open Access Journals (Sweden)

    Kelly de Moraes

    2013-03-01

    Full Text Available O objetivo do trabalho foi analisar as condições da secagem convectiva de uma pasta de anchoita (Engraulis anchoita modificada enzimaticamente, através da metodologia de superfícies de resposta, sendo as respostas consideradas: a oxidação lipídica (TBA, a redução da lisina disponível e a perda da atividade antioxidante específica. A pasta de anchoita modificada foi obtida por hidrólise enzimática da fração muscular (filés do pescado por Neutrase®. Foram avaliadas na operação de secagem, a temperatura do ar (60, 70 e 80°C e a espessura das amostras (1,5; 2,5 e 3,5mm. A análise estatística da secagem mostrou efeitos significativos da temperatura do ar e da espessura das amostras (PThe aim of the work was to analyze the conditions of the convective drying of an enzymatic modified paste of anchovy (Engraulis anchoita through the response surfaces methodology, and the responses were the lipid oxidation (TBA, reduction of the available lisina and loss of the specific antioxidant activity. The modified paste of anchovy was obtained through enzymatic hydrolysis of the fish muscular fraction (fillets by Neutrase®. In drying operation the air temperature (60, 70 and 80°C and the samples thickness (1.5, 2.5 and 3.5mm were studied. The statistical analysis of the drying showed significant effects of the air temperature and samples thickness (P<0.05. The best drying condition was obtained in the air temperature of 60°C and samples thickness of 2.5mm. In this condition the TBA index was of 0.93mgMDA kg-1, available lisina reduction of 16% and loss of the specific antioxidant activity of 20.2%.

  15. Effect of the modification of a natural mexican zeolite in the sorption of cadmium and 4-chloro phenol; Efecto de la modificacion de una zeolita natural mexicana en la sorcion de cadmio y 4-clorofenol

    Energy Technology Data Exchange (ETDEWEB)

    Cortes M, R [ININ, 52750 La Marquesa, Estado de Mexico (Mexico)

    2007-07-01

    Clinoptilolite type zeolite is a material of relative abundance in Mexico, which possess ion exchange properties and it can be used in the removal of metal ions from polluted waters. The external surface of zeolites can be modified with cationic surfactants. This modification could have a negative effect on the removal of metal ions and provides to the material the capacity to adsorb phenolic compounds. For this reason, it is important to know the capability of the modified material on the sorption of metal ions and phenolic compounds, simultaneously. The aim of this work was to evaluate the effect of the external surface modification with surfactant of a Mexican zeolite over its sorption capacity of cadmium and 4-chloro phenol, in batch and column systems. To accomplish that, a clinoptilolite type zeolitic rock from a deposit located in the state of Sonora, Mexico, was used. It was ground, sieved and characterized with different techniques; and its external surface area was modified with hexadecyltrimethylammonium bromide (HDTMA-Br). A grain size fraction was selected to carry out sorption kinetics and equilibrium experiments, as well as packed column tests with zeolitic material and solutions of cadmium and 4-chloro phenol. There are different models proposed in literature that are used to describe sorption kinetics and equilibrium. In this work, the sorption experimental results were adjusted to some of these models to identify controlling mechanisms on the kinetics and equilibrium of the studied systems. The results showed that the cadmium adsorption on natural and modified zeolite was similar in batch systems. For the case of 4-chloro phenol sorption, it was observed that natural zeolite does not retain this compound, while in modified zeolite the sorption is better than other comparable materials. The results also showed that for the case of cadmium sorption, the mechanism involved was ion exchange; while for sorption of 4-chloro phenol, a partition mechanism

  16. Comparação de parâmetros periodontais após utilização de contenção convencional 3x3 plana e contenção modificada Comparison of periodontal indexes after the use of conventional 3X3 plain retainer and modified retainer

    Directory of Open Access Journals (Sweden)

    Bianca Keiko Shirasu

    2007-02-01

    Full Text Available OBJETIVO: o presente estudo teve como propósito comparar os parâmetros periodontais após a utilização de dois tipos de contenções ortodônticas fixas: contenção convencional 3x3 plana (fio ortodôntico 0,8mm retilíneo fixado apenas nos caninos contralaterais e a contenção modificada (fio ortodôntico 0,6mm com dobras permitindo o livre acesso do fio dental e fixado em todos os dentes do segmento anterior. METODOLOGIA: quinze voluntários primeiramente utilizaram a contenção convencional por seis meses. Após um intervalo de quinze dias, foi instalada a contenção modificada, utilizada pelo mesmo período de tempo. Antes de cada fase os voluntários passaram por raspagem e alisamento radicular dos dentes e orientação de higiene bucal. Ao final de cada fase os seguintes parâmetros foram avaliados: índice de placa dentária, índice gengival e índice de cálculo dentário. Além disso, foi realizada a mensuração do cálculo no fio da contenção e todos os voluntários responderam a um questionário sobre a utilização, aceitação e conforto dos dois tipos de contenções. RESULTADOS E CONCLUSÕES: foi observado que o índice de placa e o índice gengival foram maiores para a contenção modificada (pAIM: the purpose of the present study was to compare periodontal indexes after the use of two types of bonded fixed retainers: conventional 3x3 plain retainer (orthodontic wire 0.8mm, bonded to the canine teeth only and the modified retainer (0.6mm multi strand wire, allowing free access to dental floss and bonded to all anterior teeth. METHODS: a test group of fifteen patients used the conventional retainer for 6 months. After a two week interval, the modified retainer was used for another 6 months. Previous to each phase, the patients went through tooth scaling, root planing and oral hygiene orientation. At the end of each phase the dental plaque index, gingival index and dental calculus index were evaluated. Furthermore, the

  17. Estabilidade de emulsões de d-limoneno em quitosana modificada Stability of d-limonene emulsions in modified chitosan

    Directory of Open Access Journals (Sweden)

    Camila Figueiredo Borgognoni

    2006-09-01

    Full Text Available A quitosana é um biopolímero produzido a partir da quitina, presente na casca de crustáceos. Atualmente, o estudo de suas propriedades se deve às suas diversas utilizações nas áreas farmacêutica e alimentícia. A quitosana utilizada neste estudo foi quimicamente modificada para tornar-se solúvel em água (quitosana succinilada. Estudou-se a estabilidade de emulsões com d-limoneno para que estes dados sejam úteis na sua posterior utilização como agente de encapsulação de d-limoneno por liofilização. Sua estabilidade foi analisada por espectrofotometria, em diferentes temperaturas, e por cromatografia gasosa associada à técnica da análise do espaço livre, à temperatura ambiente. Sua caracterização foi feita por microscopia óptica. Emulsões de maltodextrina com d-limoneno foram utilizadas para comparação já que maltodextrinas são muito usadas como agentes de encapsulação de aromas. Observou-se boa estabilidade de emulsões de quitosana succinilada com d-limoneno ao longo do tempo e características muito distintas em relação às observadas em emulsões de maltodextrina com d-limoneno. Pode-se concluir neste estudo que emulsões de quitosana succinilada com d-limoneno apresentaram características favoráveis à encapsulação de aromas.Chitosan is a biopolymer derived from chitin, a component of the shells of crustaceans. Recently, special attention has been given to the study of chitosan properties as a consequence of their wide application in pharmaceutical and food areas. In this study, the chitosan used was chemically modified in order to become water soluble (succinyl chitosan. The stability of succinyl chitosan emulsion with d-limonene was studied so that these results could be useful in a subsequent use of succinyl chitosan as a d-limonene encapsulating agent by lyophilization. The stability of the emulsion was analyzed using a spectrophotometer in different temperatures and by the headspace

  18. Paisagem, turismo e planejamento urbano

    Directory of Open Access Journals (Sweden)

    Bruno Luiz Domingos De Angelis

    1998-05-01

    Full Text Available O presente artigo aborda a relação entre paisagem - a urbana (modificada pela ação do homem e a natural (preservada -, turismo e o papel do planejamento urbano nesse contexto. A partir do descobrimento do Brasil, procura-se demonstrar a importância de nossa vegetação na exploração do segmento econômico-turístico e a necessidade de uma política compatível para o setor.

  19. Síntesis y caracterización de arcillas organofílicas y su aplicación como adsorbentes del fenol

    OpenAIRE

    Lazo, José C.; Navarro, Abel E.; Sun-Kou, María R.; Llanos, Bertha P.

    2008-01-01

    La característica hidrofílica intrínseca de una arcilla bentonita sódica fue modificada mediante intercambio catiónico con sales de amonio cuaternario para evaluar su capacidad para eliminar fenol a partir de soluciones acuosas. La arcilla natural no reportó adsorción significativa, mientras los cationes orgánicos: tetrametilamonio (TMA) hexadeciltrimetilamonio (HDTMA) y benciltrietilamonio (BTEA), demostraron mejorar la capacidad de adsorción de la arcilla en diferentes magnitudes. La caract...

  20. Formas farmacêuticas de liberação modificada: polímeros hidrifílicos Modified release of drug delivery systems: hydrophilic polymers

    Directory of Open Access Journals (Sweden)

    Carla Martins Lopes

    2005-06-01

    Full Text Available Os sistemas de liberação de fármacos são parte integrante da investigação farmacêutica. A maioria dos sistemas de liberação oral de fármacos é baseada em matrizes poliméricas. Nas duas décadas passadas, as matrizes hidrofílicas tornaram-se muito populares na formulação de formas farmacêuticas de liberação modificada. A escolha do polímero hidrofílico na formulação da matriz pode fornecer uma combinação apropriada dos mecanismos de intumescimento, de dissolução ou de erosão e determinam a cinética de liberação in vitro. As matrizes de intumescimento são sistemas monolíticos preparados pela compressão de mistura de um polímero hidrofílico e de um fármaco. Elas representam sistemas da liberação em que os vários mecanismos podem ser adaptados ao programa de liberação. O sucesso desses sistemas está relacionado com a tecnologia de fabricação e com as características físicas e físico-químicas do polímero, responsáveis pelo mecanismo de liberação.Drug delivery systems (DDS became an integral part of pharmaceutical research. The majority of oral DDS are matrix-based systems. Hydrophilic matrices for the past two decades have been popular in the formulation of controlled release solid dosage forms. Swellable matrices are monolithic systems prepared by compression of a powdered mixture of a hydrophilic polymer and a drug. They represent a delivery system in which various mechanisms can be adapted to the delivery program. Their success is linked to the established tabletting technology of manufacture. The choice of the hydrophilic polymer in the matrix formulation can provide an appropriate combination of swelling, dissolution or erosion mechanisms to evaluate in vitro release kinetics.

  1. Produção de três espécies de cogumelos Pleurotus e avaliação da qualidade em atmosfera modificada Production of three species of Pleurotus mushrooms and quality evaluation in modified atmosphere

    Directory of Open Access Journals (Sweden)

    Cristina Ramos

    2011-01-01

    Full Text Available A utilização de substratos vegetais à base de palha tem vindo a assumir uma importância crescente na cultura de cogumelos sapróbios, principalmente do género Pleurotus. Estes cogumelos são considerados muito interessantes do ponto de vista comercial, não só pelas suas características organolépticas e nutricionais, mas também pela sua fácil adaptação e manutenção, crescimento rápido e relativo baixo custo de cultura. No entanto, por se tratar de alimentos perecíveis, devido sobretudo à sua composição e elevada taxa respiratória, podem apresentar reduzido valor comercial, caso a conservação não seja efectuada nas melhores condições. No sentido de minimizar estas alterações, os cogumelos frescos devem ser submetidos a um processamento mínimo com utilização combinada de embalagem em atmosfera modificada, de forma a manter a qualidade e estabilidade no período de conservação. Neste trabalho foram efectuados ensaios de produção de três espécies do género Pleurotus, cultivadas em palha de trigo, com a finalidade de determinar a espécie mais produtiva e avaliar a qualidade dos mesmos durante a conservação quando processados e embalados em atmosfera modificada. Os resultados permitem concluir que a espécie mais produtiva foi a P. ostreatus, seguida da P. sajor-caju e P. eryngii, tendo sido a P. eryngii a que mostrou maior resistência à degradação no período de conservação estabelecido.The use of substrates straw has been increasing importance in mushroom saprophytic species grown, especially of Pleurotus genus. They are considered very interesting from the commercial point of view, not only for its nutritional and organoleptic characteristics, but also for its easy adaptation, rapid growth and relatively low culture cost. Mushrooms have a short shelf life when compared to most vegetables at ambient temperatures mainly due to its composition and high respiration rate. After yield and to reduce losses and

  2. REDUCCIÓN DE ÓXIDOSDE NITROGENO CON CATALIZADORES ZEOLÍTICOS INTERCAMBIADOS CON COBALTO

    Directory of Open Access Journals (Sweden)

    Enrique Alexis García Moya

    2012-10-01

    Full Text Available Se presenta un estudio sobre la reducción catalítica selectiva (RCS de NOx con metano en presencia de oxígeno en exceso con varios catalizadores a base de las zeolitas mordenita, ferrierita y ZSM-5 intercambiadas con diferentes cargas de cobalto y con las correspondientes zeolitas en forma acida. Cuando la mezcla reactiva contenía mayormente NO2 en lugar de NO, los catalizadores ácidos mostraron las más altas velocidades de formación de N2 en condiciones secas. Las mayores actividades se obtuvieron con los catalizadores Co-mordenita, siguiendo en orden de actividad los catalizadores Co-Ferrierita y Co-ZSM-5. El catalizador Co-Mordenita más activo se ensayó con una mezcla reactiva donde predominó el NO en lugar del NO2 bajo condiciones secas e hidrotérmicas y en presencia de SO2. Con la adición de 8% de agua a la mezcla de reacción se observó desactivación reversible, especialmente a bajas temperaturas. La adición de 60 ppm de SO2 disminuyó la velocidad de reacción aproximadamente a la mitad debido posiblemente al envenenamiento de algunos sitios activos.

  3. Effect of the humic acids in the adsorption of U (Vi) in a Mexican natural zeolite; Efecto de los acidos humicos en la adsorcion de U (VI) en una zeolita natural mexicana

    Energy Technology Data Exchange (ETDEWEB)

    Sandoval G, H. A.; Lopez del R, H.; Davila R, J. I.; Mireles G, F., E-mail: hlopezdelrio@hotmail.com [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico)

    2012-10-15

    The uranium adsorption was studied in a Mexican natural zeolite of the clinoptilolite type in presence and absence of humic acids (Ha). The adsorption kinetics of the binary U-zeolite and ternary U-Ha-zeolite systems were compared, and the effect of the humic matter impregnated in the zeolite in the uranium removal in function of the solution ph was studied. The experiments were made to environmental conditions and lightly acid ph, with fixed concentrations of uranium and Ha of 1 x 10{sup -5} M and 20 ppm, respectively, and a reason m/V of 5 mg/ml. The uranium adsorption in absence of Ha was of 96% and decreased to 45% in the ternary system U-Ha-zeolite. The data of the binary system U-zeolite were analyzed with three kinetic models of adsorption (pseudo-first order, pseudo-second order and Elovich). By means of non lineal regression was found that the uranium adsorption obeys a kinetic of pseudo-second order. It was observed that the uranium adsorption in the zeolite impregnated with Ha is favored to more ph at 5. (Author)

  4. Combined used of natural zeolites and microalgaes for the denitrification of wastewater from fertilizer plants; Uso combinado de zeolitas naturales y microalgas en la denitrificacion de aguas residuales

    Energy Technology Data Exchange (ETDEWEB)

    Soca Olazabal, N.; Blanco Toledo, F.; Pizarro Camacho, D.

    1997-06-01

    In our work we investigated the process of denitrification of waster-water with high percentage of nitrate and ammonia using natural zeolites that can be used later in agricultures fertilizer, because of the nitrogen load received. This effluents was used for micro algae growth reducing the nitrate concentration, the micro algae was Chlorella Vulgaris. The zeolite reduced the NH``+{sub 4} concentration up to 5 mg/l. and the NH``+{sub 4} concentration in the zeolite, it si very important in the agriculture. The chlorella Vulgaris reduces 30 mg/l of nitrate in six hours in the steady state. (Author) 9 refs.

  5. Efeito de diferentes tipos de argilas e modificadores orgânicos na morfologia e propriedades térmicas dos nanocompósitos de PET Effect of different types of clays and organic modifiers on the morphology and thermal properties of PET nanocomposites

    OpenAIRE

    Itamara Farias Leite; Oscar Loureiro Malta; Claudia M. O. Raposo; Luís Eduardo Canedo; Laura H. de Carvalho; Suédina M. de L. Silva

    2011-01-01

    Argilas bentoníticas natural e purificada (AN e AP) e montmorilonita (MMT), modificadas organicamente com os sais alquil amônio (A), alquil fosfônio (F) e com uma mistura de ambos (A e F), foram incorporadas, em teor de 1% em massa, ao PET pelo processo de fusão. Os híbridos obtidos foram caracterizados por difratometria de raios X (DRX), termogravimetria (TG), calorimetria exploratória diferencial (DSC) e microscopia eletrônica de transmissão (MET). Nanocompósitos com morfologia intercalada ...

  6. Onicomicosis: resultados preliminares del tratamiento clinicoquirúrgico en un grupo de pacientes

    Directory of Open Access Journals (Sweden)

    Rubén Pérez Armas

    1995-08-01

    Full Text Available Se hace un estudio de 40 pacientes con onicomicosis tratadas con la técnica quirúrgica seguida de aplicación local de zeolita esterilizada al 100 %, en el Servicio de Dermatología del Hospital Provincial Clinicoquirúrgico "Celia Sánchez Manduley" en el período comprendido entre mayo de 1992 y mayo de 1993. Sólo participaron pacientes con los criterios de inclusión propuestos en el protocolo de investigación. El 30 % correspondió a candidiasis ungueal y el 70 % a tiña ungueal. Se observaron resultados excelentes de curación en el 96,8 %. El tiempo mínimo de curación fue de 3 meses y el máximo de observación de 6 meses. Se subrayan las ventajas de esta técnsica en comparación con otros tratamientos utilizados según reportes de la literatura médica revisada, porque acorta el tiempo de curación y tratamiento, disminuye el costo por paciente curado, se evitaron los efectos secundarios que los medicamentos de nuevo tipo pueden producir, disminuyendo además sus importaciones con el consiguiente ahorro de divisas para el país. Demuestra el efecto polivalente de la zeolita tópica al 100 % sobre los dermatofitos y candidas.

  7. Qualidade de mangas 'Tommy Atkins' armazenadas sob atmosfera modificada Quality of 'Tommy Atkins' mangoes stored under modified atmosphere

    Directory of Open Access Journals (Sweden)

    Elisangela Marques Jeronimo

    2007-08-01

    Full Text Available Objetivou-se com este trabalho avaliar a qualidade pós-colheita de mangas 'Tommy Atkins', durante o armazenamento refrigerado, utilizando diferentes tipos de embalagens. Os tratamentos foram: frutos acondicionados individualmente em bandejas de acetato transparente, revestidas com filme plástico de cloreto de polivinila (PVC esticável de 14 µm, sem e com sachê de permanganato de potássio, preparado utilizando-se vermiculita como substrato, impregnada com KmnO4 (10 g / 500 g de fruto; frutos acondicionados individualmente em sacos plásticos de polietileno de baixa densidade 25 µm de parede simples (PE confeccionado ou não com permanganato de potássio e frutos acondicionados, em grupos de 5, em caixas de papelão com tampa, revestidas internamente ou não, com filme plástico confeccionado com permanganato de potássio. Os frutos foram armazenados a 13 ± 1°C, 85-90% UR por 20 dias e então transferidos para as condições de ambiente de 24,4 °C, 70% UR. Foram avaliadas a perda de massa fresca, aparência, firmeza da polpa, teor de sólidos solúveis, acidez titulável e ácido ascórbico. Verificou-se que o melhor tratamento de atmosfera modificada foi o de acondicionamento individual dos frutos de manga em bandejas de acetato transparentes, recoberta com o filme de PVC esticável. O permanganato de potássio na forma utilizada neste estudo (sachê e impregnado em filme plástico não interferiu nos resultados obtidos para a conservação dos frutos.The objective of this experiment was to evaluate the post harvest quality of 'Tommy Atkins' mangoes during refrigerated storage, using different types of packing. The modified atmosphere corresponded to the following treatments: fruits conditioned individually in plastic trays, covered with plastic film of polivinil chloride (PVC of 14 µm, without and with sachet of potassium permanganate (10 g; fruits conditioned individually in low density simple wall polyethylene bag of 25 µm made

  8. Sorption of cobalt in zeolites and natural clays of the clinoptilolite and kaolinite type; Sorcion de cobalto en zeolitas y arcillas naturales del tipo clinoptilolita y caolinita

    Energy Technology Data Exchange (ETDEWEB)

    Davila R, J.I.; Solache R, M. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    2006-07-01

    In this work the sorption of cobalt of aqueous solutions in two natural zeolites (clinoptilolite) and a clay (kaolinite) of origin in the center-north region of Mexico is evaluated. The effect of the pH and the time of contact in the process of sorption were evaluated. The cobalt retained in the aluminosilicates was determined by neutron activation analysis. The cobalt sorption in the materials in a range of pH from 4 to 7 does not present significant variations. The studies of reaction kinetics show a very fast sorption in the first 5 hours of contact, reaching the equilibrium in approximately 24 hours. The kinetics of sorption of the cobalt ions was represented better by the Ritchie reaction model modified of second order. The experimental data for the zeolites obtained at ambient temperature and varying the concentration were adjusted to the models of Freundlich, Langmuir and Freundlich-Langmuir isotherms and it was observed that the cobalt sorption it behaves according to the Freundlich isotherm model. (Author)

  9. Evaluation of mature landfill leachates Treatment systems: the case of the landfill Curva de Rodas (Medellín-Colombia

    Directory of Open Access Journals (Sweden)

    Sebastian Canizales

    2013-01-01

    Full Text Available Los lixiviados producidos en el relleno sanitario clausurado Curva de Rodas de la ciudad de Medellín se catalogan como “lixiviados maduros”, estos se caracterizan por ser un residuo poco biodegradable. En este trabajo se evalúa la eficiencia de cinco posibles tratamientos fisicoquímicos: adsorción con 5 tipos de carbón activado granular (CAG, adsorción con Zeolita tipo A, oxidación Fenton, precipitación química con Ca(OH2 y coagulación- floculación con Sulfato de Aluminio Tipo A. Mediante la adsorción con CAG se alcanzaron remociones de hasta 39% para DQO y 50% para Color. En el caso de adsorción con Zeolita tipo A se lograron remociones de hasta 3% en DQO y 7% en Color. En los ensayos de precipitación química se lograron remociones máximas de 16% en DQO y 50% en color y por el proceso de coagulación-floculación hasta del 27% en DQO y del 63% en color. Los mejores resultados se obtuvieron con el proceso de oxidación Fenton, neutralizando con NaOH se lograron remociones máximas de 95% en DQO y 97% en color. Al neutralizar con lixiviado sin tratar las remociones alcanzadas fueron de hasta 79% en DQO y 87% en color.

  10. Influência do armazenamento refrigerado em associação com atmosfera modificada por filmes plásticos na qualidade de mangas 'Tommy Atkins Influence of refrigerated storage associated with plastic film-modified atmosphere in quality of 'Tommy Atkins' mangoes

    Directory of Open Access Journals (Sweden)

    Joaci Pereira de Sousa

    2002-12-01

    Full Text Available Avaliou-se a qualidade de mangas Tommy Atkins, embaladas em filmes plásticos e armazenadas sob condição refrigerada. Utilizaram-se frutos da safra 2000 obtidos na Fazenda Paulicéia Empreendimentos Ltda., situada no Pólo Agrícola Mossoró-Assu. Os frutos foram colhidos no estádio 2 (Brix 7 º e 75% verde e 25% vermelha e selecionados de acordo com o tipo 12 (12 frutos/caixa e tratados com fungicida para evitar podridões. No laboratório, os frutos foram submetidos aos seguintes tratamentos: 1 - frutos não embalados; 2 - frutos embalados individualmente em cloreto de polivinila (PVC; 3 - frutos embalados em sacola de polietileno de alta densidade (PEAD; 4 - frutos embalados em sacola de polietileno de baixa densidade (PEBD. Os frutos foram armazenados por 42 dias em condição controlada (11 ± 1°C; 85-90% UR. O armazenamento dos frutos sob condição controlada, associada à atmosfera modificada pelos filmes plásticos, reduziu-lhes a perda de matéria fresca e proporcionou-lhes a manutenção dos teores de sólidos solúveis totais, açúcares solúveis totais e acidez total titulável. A atmosfera modificada pelos filmes plásticos manteve mais regular as perdas na firmeza da polpa, possibilitando uma vida útil pós-colheita de 42 dias em ralação à testemunha. Até o final do armazenamento, o uso de PEAD promoveu o desenvolvimento da coloração da casca e da polpa dos frutos, porém o uso de PVC e PEBD reteve a coloração da casca.The quality of mangoes cv Tommy Atkins enclosed in plastic films and stored under refrigerated conditions were evaluated. Mangoes from the 2000 crop harvested at the Fazenda Paulicéia Empreendimentos Ltda., located in the Mossoró-Assu Agropole were used as experimental unity. The fruits were harvested in stage 2 ( 7º brix and 75% green, 25% red and selected for the type 12 (12 fruits/box, then treated with fungicide to prevent rots. The fruits were submited to the following treatments in the

  11. Limpieza bucodental mediante técnicas de adsorción con material desechable: nueva alternativa de higiene oral

    OpenAIRE

    J.M. González-González

    2014-01-01

    El objetivo de este trabajo es mostrar diferentes materiales para hacer limpieza bucodental, con alto poder de adsorción, atóxicos y desechables (de usar y tirar), que masticados en la boca permitan arrastrar la placa bacteriana. Material y métodos: Se ha seleccionado información válida para el estudio en la base de datos medline, red de internet y bibliografía de archivos propios. Resultados: Entre los materiales hallados están: las sepiolitas, zeolitas, agares, carbón activo, polímeros de l...

  12. Alquilación de isobutano con olefinas: estudio de catalizadores sólidos ácidos

    OpenAIRE

    Dalla Costa, Bruno Oscar

    2013-01-01

    En esta tesis se evalúan diferentes catalizadores para la reacción de alquilación de isobutano con olefinas. Se estudian zeolitas microporosas, Y, X, Beta y Mordenita. Estos materiales presentan diferentes relaciones Si/Al y la regulación de acidez se realiza mediante intercambio iónico con La+3 y/o NH4+. Se presenta también el diseño de catalizadores mesoporosos, estudiándose sílices SBA-15 funcionalizadas con grupos sulfónicos. Los materiales microporosos con niveles de acidez moderados son...

  13. A musculatura epaxial e a fibrose epidural na compressão medular em cães submetidos à laminectomia dorsal modificada

    Directory of Open Access Journals (Sweden)

    Diego V. Beckmann

    2010-02-01

    Full Text Available O objetivo deste experimento foi isolar a musculatura epaxial da medula espinhal de cães submetidos à laminectomia dorsal modificada (LDM e averiguar se os músculos influenciaram na formação da fibrose epidural, na compressão medular e no aparecimento dos sinais neurológicos. Para isso, dez cães hígidos foram submetidos à LDM entre as vértebras T13 e L1 e distribuídos aleatoriamente em dois grupos denominados controle (I onde a medula espinhal permaneceu exposta sem a presença de implante, e tratado (IIonde foi colocado um im-plante a base de alumínio entre a musculatura epaxial adjacente e a medula espinhal exposta pela LDM. As avaliações constaram de exames neurológicos diários até 180 dias de pós-operatório (PO; mielografia, decorridos 15, 30 e 60 dias de PO; e avaliação macroscópica mediante a reintervenção cirúrgica. Não houve diferença durante as avaliações neurológicas. Aos 15 dias de PO, foi verificado na mielografia, que o grau de compressão da linha de contraste foi maior no grupo tratado (PThe purpose of this study was to isolate the adjacent epaxial musculature from exposed spinal cord by modified dorsal laminectomy in dogs with aluminum implant and to verify whether the muscles contribute to form epidural fibrosis, spinal cord compression, and development of neurological signs. Ten dogs were submitted to modified dorsal laminectomy between T13 and L1 and then distributed along two groups. Dogs in the group 1 remained with the spinal cord exposed without the implant; dogs in the group 2 had an aluminum implant inserted between the epaxial muscles and the exposed spinal cord. Neurological examination was daily performed until 180 days post surgery. Additionally, myelography at 15, 30, and 60 days post surgery and macroscopic evaluation of the implant at six months post surgery were done. There was no difference between groups in the neurological examination. A statistical difference in the degree of

  14. Evaluación de la anatomía mandibular relacionada con la osteotomía sagital de rama: estudio realizado en mandíbulas humanas adultas secas de cráneos de raza mestiza pertenecientes al departamento de anatomía de la Facultad de Odontología: Universidad Central del Ecuador

    OpenAIRE

    Daniela Mayorga; Diego Patricio Maldonado Coloma

    2015-01-01

    En la actualidad la osteotomía sagital de la rama mandibular representa una de las técnicas quirúrgicas más frecuentes utilizada en cirugía ortognática. Sin embargo desde su aparición ha venido siendo modificada hasta lograr los niveles de estandarización que posee en la actualidad. Dicha técnica ha sido modificada en diseño, extensión e instrumentación. El presente trabajo investigativo ha sido llevado a cabo con la finalidad de prevenir problemas anatómicos y quirúrgicos a través del estudi...

  15. Theories of modified gravity and reconstruction schemes of cosmological models

    OpenAIRE

    López Revelles, Antonio Jesús

    2013-01-01

    [spa] En esta memoria de tesis se expone el trabajo llevado a cabo por el doctorando durante los últimos cuatro años, el cual versa principalmente sobre diversos aspectos de soluciones cosmológicas obtenidas a partir de teorías de gravedad modificada. Para entender el origen y la importancia de las teorías de gravedad modificada es necesario comentar antes algunos hechos acontecidos durante el siglo XX en el marco de la cosmología. La cosmología como ciencia nació gracias a la Teoría de la Re...

  16. Estabilidad en el almacenamiento congelado de rebanadas de lomo de atún rojo (Thunnus sp. empacadas en atmósfera modificada con CO2

    Directory of Open Access Journals (Sweden)

    Myrna Luisa Medina Bracamonte

    2014-12-01

    Full Text Available La disponibilidad atún rojo fresco, entero y rebanado, como todo producto pesquero fresco está restringida para los consumidores en zonas distantes a los centros de producción por su estabilidad limitada en el almacenamiento. Por ello la industria pesquera en general, en la época de mayor producción, recurre a la congelación para conservar el excedente de producción, y al empacado para protegerlo del ambiente frío y seco del congelador, evitar su deshidratación y “quemaduras por frío”. El surgimiento del Empacado en Atmósfera Modificada como alternativa para incrementar la vida útil de productos alimenticios despertó la inquietud de evaluar la estabilidad de rebanadas de lomo de atún rojo (Thunnus sp. fresco, congeladas y empacadas con 100 % de CO2 durante su almacenamiento a las temperaturas convencionales para su distribución y venta, -10 y -18 ºC, evaluando la estabilidad química, física, microbiológica y sensorial de las rebanadas de lomo de atún rojo durante ≈ 4 meses de almacenamiento congelado. El 50 % de las rebanadas se congeló a -10 ºC (Tratamiento 1 y el 50 % restante a -18 ºC (Tratamiento 2. Las rebanadas congeladas se empacaron individualmente, el 50 % en atmósfera de 100 % de CO2 conservando la proporción 1:2 (rebanada:gas y el 50 % restante en atmósfera de aire. Se almacenaron a la temperatura correspondiente: Tratamiento 1 a -10 ºC y Tratamiento 2 a -18 ºC durante 111 días. Al final del almacenamiento el tratamiento P2 (100 % CO2 ofreció mejor barrera a la pérdida de humedad, favoreció la estabilidad de la fracción de proteínas solubles en solución salina. Las muestras P2 tuvieron mayor aceptación sensorial, fueron las más oscuras y rojas, con menor recuento microbiológico, coincidiendo con el menor contenido en bases volátiles totales. A -10 ºC la atmósfera de 100 % de CO2 no evitó la “quemadura por frío” y los panelistas percibieron el “olor a pescado”.

  17. Avaliação da utilização de embalagem em atmosfera modificada sobre a conservação de sardinhas (Sardinella brasiliensis Evaluation of the use of modied atmosphere packaging in sardine (Sardinella brasiliensis preservation

    Directory of Open Access Journals (Sweden)

    Anderson Junger Teodoro

    2007-03-01

    Full Text Available A vida útil dos alimentos perecíveis conservados em atmosfera normal é limitada principalmente pelo efeito do oxigênio atmosférico e o crescimento de microorganismos aeróbios produtores de alterações, que promovem mudanças de odor, sabor, cor e textura, conduzindo à perda da qualidade. A modificação da atmosfera prolonga significativamente a vida útil dos alimentos, quando comparados à refrigeração, podendo chegar a um aumento de três a quatro vezes. O trabalho teve como objetivo avaliar o efeito da embalagem de sardinhas (Sardinella brasiliensis em atmosfera modificada. As amostras foram divididas em 8 lotes, embaladas com aproximadamente 1,5 L de ar (100%, CO2 (100%, 50/50 CO2/O2 e vácuo e termo-seladas, sendo armazenadas por um período de 22 dias. A cada 2 dias as amostras foram avaliadas quanto ao pH, bases voláteis totais (BVT e contagens totais de microrganismos heterotróficos aeróbios mesófilos. Os valores de pH aumentaram durante o tempo de estocagem, com exceção das amostras armazenadas em 100 e 50% CO2. A evolução de BVT foi compatível com outros parâmetros, como pH e contagem de bactérias totais, sendo sua evolução mais lenta nas amostras em que ocorreu o uso de atmosfera modificada. Os microrganismos mesófilos, nas atmosferas enriquecidas com CO2, apresentaram fases de latência e tempos de duplicação maiores, quando comparados com os das amostras em que não foi aplicado o método. Sob o ponto de vista microbiológico, as embalagens enriquecidas com CO2 demonstraram ser o melhor método de conservação, como também os resultados de BVT se encontraram dentro dos limites de 30 mg.100 g -1 de acordo com o estabelecido pela RIISPOA8. Recomenda-se o uso da atmosfera de 100% de CO2 como forma de conservação da sardinha por apresentar melhores parâmetros de vida útil.The objective of the work was to evaluate the effect of sardines (Sardinella brasiliensis packaged in a modified atmosphere. The

  18. Desenvolvimento de nanocompósitos à base de amido de batata

    Directory of Open Access Journals (Sweden)

    Luciana Macedo Brito

    2013-01-01

    Full Text Available Nanocompósitos de amido de batata foram preparados pelo método de intercalação por solução, com a adição de argilas montmorilonita: organicamente modificada (Viscogel B8 e não modificada argila sódica (NT25 e de sílicas: modificada (R972 e não modificada (A200. Os nanocompósitos foram caracterizados pelas técnicas convencionais de difratometria de raios X e análise termogravimétrica. Foram caracterizados também por uma técnica denominada como não convencional, a ressonância magnética nuclear (RMN de baixo campo, que é alternativa e efetiva na caracterização de nanocompósitos. Com ela, pode-se investigar a dispersão das nanocargas pelo grau de intercalação e/ou esfoliação, além de verificar a distribuição e modificações da mobilidade molecular da matriz polimérica. Os materiais nanoestruturados obtidos com as argilas apresentaram boa dispersão e formação de nanomateriais mistos, com diferentes graus de intercalação e esfoliação. Ao adicionar as sílicas na matriz de amido pode-se observar uma diminuição da mobilidade do material, este efeito foi observado para ambas às sílicas utilizadas. Utilizando a técnica de TGA verificou-se um ligeiro aumento na estabilidade térmica do material produzido em relação ao amido.

  19. Avaliação do ganho funcional do cotovelo com a cirurgia de Steindler na lesão do plexo braquial

    OpenAIRE

    Rezende,Marcelo Rosa de; Massa,Bruno Sergio Ferreira; Furlan,Fernando Cesar; Mattar Junior,Rames; Paula,Emygdio Jose Leomil de; Santos,Simone Silva e; Freitas,Maura Cristina

    2011-01-01

    OBJETIVO: Avaliar ganho de força e amplitude de movimento do cotovelo após cirurgia de Steindler Modificada em pacientes com lesão do tronco superior do plexo braquial. MÉTODO: Foram acompanhados de 1998 a 2007 onze pacientes com lesão traumática fechada do tronco superior do plexo braquial. Todos apresentavam evolução de pelo menos 1 ano da lesão e grau de força de flexão do cotovelo que variou de M1 a M3. Os pacientes foram submetidos à cirurgia de Steindler modificada e seguidos por períod...

  20. Reconversión de catalizadores agotados de FCC para su uso en purificación de efluentes acuosos

    OpenAIRE

    Gonzalez, Maximiliano Ricardo; Pereyra, Andrea M.; Basaldella, Elena Isabel

    2015-01-01

    Se plantea la utilización de un catalizador FCC agotado como materia prima para sintetizar materiales zeolíticos, obteniéndose un sólido micrométrico con un alto contenido de zeolita NaA. El material zeolitizado se emplea a su vez para la eliminación del cromo trivalente presente en soluciones acuosas, comprobándose que presenta una gran capacidad de retención de Cr(III). Estos cationes pesados quedan contenidos en el seno de la fase sólida, la cual a su vez puede incluirse minoritariamente e...

  1. Efecto de la plata sobre el proceso de síntesis por fusión de un pigmento del tipo azul ultramarino

    OpenAIRE

    Castillo, Wilmer; González, Luis; Sánchez, Selene; Ocanto, Freddy; Linares, Carlos F

    2011-01-01

    Se realizó la síntesis de pigmentos inorgánicos del tipo azul ultramarino a partir de la mezcla de zeolita A, carbonato de sodio, azufre elemental y contenido de plata entre un 0 al 5% p/p a una temperatura de 800°C por espacio de 4h. Los sólidos fueron caracterizados por la técnicas de difracción de rayos X (DRX), infrarrojo con transformada de Fourier (FTIR) y espectroscopia de reflectancia de UV a fin de verificar la estructura y coloración de los materiales obtenidos. Los resultados mostr...

  2. Desproporción de etilbenceno en condiciones sub y supercríticas sobre materiales zeolíticos

    OpenAIRE

    Gómez Jiménez, Pilar

    2010-01-01

    El presente trabajo se encuadra en un área de investigación en la que confluyen tres líneas que se vienen desarrollando en el Departamento de Ingeniería Química de la Facultad de Ciencias Químicas de la Universidad Complutense de Madrid relativas a la síntesis, modificación y aplicación de zeolitas y zeotipos; el desarrollo de procesos catalíticos, y las aplicaciones de la tecnología supercrítica. Los compuestos aromáticos presentan una gran variedad de aplicaciones para la industria química ...

  3. Estudo da validade e confiabilidade intra e interobservador da versão modificada do teste de Schöber modificado em indivíduos com lombalgia Study of validity and intra and inter-observer reliability of modified-modified Schöber test in subjects with low-back pain

    Directory of Open Access Journals (Sweden)

    Christiane de Souza Guerino Macedo

    2009-09-01

    Full Text Available Em pacientes com lombalgia, mensura-se a amplitude de movimento (ADM da coluna lombar por meio da versão modificada do teste de Schöber modificado (MTSM, mas suas propriedades psicométricas não são comprovadas para uso clínico. Este estudo verificou a validade e confiabilidade intra e interobservador do MTSM em indivíduos com lombalgia, comparando as medidas da ADM com as obtidas por meio de radiografia, método considerado padrão-ouro. Participaram 20 voluntários com lombalgia, de ambos os sexos, funcionários de um Hospital Universitário. O MTSM foi aplicado duas vezes por dois avaliadores. As medidas obtidas pelo teste e por radiografia foram comparadas usando o coeficiente de correlação de Pearson, obtendo-se r=0,14, ou seja, correlação fraca. O coeficiente de correlação intraclasse (CCI dos MTSM intra-observador foi 0,96 (IC 95% 0,91;0,98 e interobservador 0,93 (IC 95% 0,84;0,97, indicando alta confiabilidade; o teste de Bland & Altman mostrou alta concordância intra e interobservador, com valores de -0,21 e -0,28, respectivamente. Embora tenha sido encontrada alta confiabilidade intra e interobservador na aplicação da versão modificada do teste de Schöber modificado, este apresentou baixa validade para medir a ADM da coluna lombar, quando comparado ao padrão-ouro.In patients with low-back pain the lumbar spine range of motion (ROM is often measured by the modified version of the modified Schöber test (MMST, but its psychometric properties have not been ascertained for clinical use. The purpose here was to verify intra and inter-observer validity and reliability of the MMST in subjects with low-back pain, and to compare obtained ROM measures to those obtained by radiography, taken as gold standard. The study involved 20 subjects with chronic low-back pain, of both sexes, employees at a university hospital. The MMST was applied twice by two examiners each. The Pearson correlation coefficient found when comparing

  4. Estudo transversal de ansiedade pré-operatória em crianças: utilização da escala de Yale modificada Estudio transversal de ansiedad preoperatoria en niños: utilización de la escala de Yale modificada A transversal study on preoperative anxiety in children: use of the modified Yale scale

    Directory of Open Access Journals (Sweden)

    Álvaro Antônio Guaratini

    2006-12-01

    Full Text Available JUSTIFICATIVA E OBJETIVOS: O emprego de escalas pode ser útil no reconhecimento dos estados de ansiedade, direcionando medidas que previnam complicações decorrentes de níveis elevados de ansiedade. A escala de ansiedade pré-operatória de Yale modificada (EAPY-m foi desenvolvida para avaliação da ansiedade em crianças na idade pré-escolar no momento da indução da anestesia. Essa escala possui caráter observacional e é rápida de ser completada. Os estudos sobre ansiedade em crianças no período pré-operatório não fazem menção à ansiedade no momento da avaliação pré-anestésica ambulatorial (APA. Este estudo transversal procurou avaliar o nível e a prevalência de ansiedade no momento da APA e da consulta clínica utilizando a escala EAPY-m, em crianças em idade pré-escolar. MÉTODO: Foram selecionadas 100 crianças, estado físico ASA I e IIi: G PED = 50 crianças a serem submetidas à avaliação clínica; G APA = 50 crianças a serem submetidas à apa para programação cirúrgica. O estudo se desenvolveu na sala de espera dos ambulatórios de pediatria e de apa enquanto as crianças aguardavam as consultas. Dois observadores aplicaram a escala EAPY-m de forma independente. Os parâmetros analisados foram dados sociodemográficos; mediana e porcentagem de pacientes com ansiedade (EAPY-m > 30. Foi realizada a análise estatística, sendo considerado significativo p JUSTIFICATIVA Y OBJETIVOS: La utilización de escalas puede ser útil en el reconocimiento de los estados de ansiedad, dirigido a medidas que prevengan complicaciones provenientes de niveles elevados de ansiedad. La Escala de Ansiedad Preoperatoria de Yale modificada (EAPY-m fue desarrollada para la evaluación de la ansiedad en niños en la edad preescolar al momento de la inducción de la anestesia. Esa escala posee un carácter de observación y es muy fácil para ser completada. Los estudios sobre ansiedad en niños en el período preoperatorio no

  5. Plantas transgênicas resistentes a insetos e organismos não-alvo: predadores, parasitóides e polinizadores - doi: 10.5102/ucs.v4i1.23

    Directory of Open Access Journals (Sweden)

    Marina Regina Frizzas

    2008-04-01

    Full Text Available Plantas geneticamente modificadas resistentes aos insetos oferecem benefícios à agricultura moderna. No entanto, esta tecnologia pode afetar o controle biológico natural e a biodiversidade por meio de efeitos diretos e indiretos das plantas transgênicas sobre o valor adaptativo e comportamental de predadores, parasitóides, polinizadores e outros artrópodes não-alvo. Neste artigo, são discutidos os impactos ou os efeitos potenciais de plantas transgênicas resistentes a insetos sobre organismos não-alvo, com ênfase em artrópodes predadores, parasitóides e polinizadores, e os principais estudos com plantas transgênicas resistentes a insetos, publicados nos últimos dez anos.

  6. Regeneration of clinoptilolite zeolite used for the ammonium removal; Regeneracion de zeolita clinoptilolita empleada para la remocion de amonio

    Energy Technology Data Exchange (ETDEWEB)

    Garcia G, M C

    2002-07-01

    The use of zeolites has been increased in the last years with different applications and with a great boom in the environmental area, but a little had been make about the regeneration of such zeolites. The presence of nitrogen-ammonia in water may cause serious pollution problems since it results to be toxic for fishes and other aquatic life forms, also it provokes the algae growing. The natural clinoptilolite contains interchangeable ions such as the sodium (Na{sup +}), potassium (K{sup +}), magnesium (Mg{sup 2+}) and calcium (Ca{sup 2+}) in different proportions depending on the mineral origin When the zeolite is upgraded to its sodium form, the cation exchange capacity and the preference by the nitrogen-ammonia are increased, allowing the reversible process of sorption. In this work it was proposed the regeneration to its sodium form about the ammonia clinoptilolite zeolite. The natural mineral was characterized using the methods such as: X-ray diffraction, Infrared spectroscopy, Thermal gravimetric analysis and surface area. The results show that the ammonium sorption was between 95% and 98.7% such an ambient temperature as a flow back. the zeolite was regenerated approximately from 60% in the first cycle up to 97% in the last cycle at flow back temperature and of 59.2% up to 96.9% at ambient temperature, it was not presented any significant effect which could be attributed to the temperature. During the exchange process, the cations present in the natural zeolite were exchanged with the ammonium ions, this process was not completed due to that retained ammonium quantity was major that of the desorpted ions, what shows that in addition of ion exchange, another type of sorption process exists. (Author)

  7. Estudo retrospectivo de 11 casos de aerofagia em equinos operados pela técnica de miectomia de Forssell modificada Modified Forssell's myectomy operation in windsucking horses: a retrospective study of 11 cases

    Directory of Open Access Journals (Sweden)

    José Luiz de Mello Nicoletti

    1996-12-01

    Full Text Available No presente trabalho foi feita unta revisão do resultado pós-operatório com a técnica de miectomia de Forssell modificada aplicada em 11 equinos portadores de aerofagia, atendidos no Hospital Veterinário da FMVZ-UNESP, Botucatu, no período entre julho de 1992 e abril de 1995. A técnica consiste basicamente na ressecção dos músculos omohioídeo, esternohioídeo e esternotirohioídeo associado à neurectomia do ramo ventral do nervo acessório, que inerva o músculo esternomandibular. As informações sobre a evolução pós-operatória. que variou entre 4 e 36 meses, foram obtidas por contacto telefônico ou carta questionário. As raças acometidas foram: Quarto de Milha (5 animais. Apaloosa (4 animais, Mangalarga (1 animal e Brasileira de Hipismo (1 animal, sendo 7 fêmeas e 4 machos, e as idades variaram entre 1,5 e 11 anos. O resultado pós-operatório mostrou que 7 animais (63.3% estavam totalmente recuperados; 2 animais (18.1% recuperaram-se parcialmente pois o problema recidivou embora em menor intensidade entre 30 e 90 dias após a cirurgia e 2 animais (18,1% não tiveram nenhuma melhora.The objective of this study was to observe the long-term results of the modifica Forssell's operation to correct windsucking in 11 horses. The post-operative results was obtained by telephone and written reports, 4 to 36 months after operation. Seven animals (63.3% became free of the vice. while two horses (18.1% were recorded as having partial improvement. The other two horses (18.1%, retumed to windsucking as the same as before surgery. Cosmetic results were considered excellent in the owners opinion.

  8. Estudio computacional de modelos físicos en estructuras porosas

    OpenAIRE

    Sánchez Brasero, Javier

    2009-01-01

    Proyecto Fin de Carrera leído en la Universidad Rey Juan Carlos en el curso académico 2008/2009. Tutores del Proyecto: Jesús Miguel Seoane Sepúlveda y José María Escola Sáez La difusión en zeolitas es un fenómeno de una gran importancia en ingeniería química. Esta difusión se diferencia de la difusión ordinaria en el sentido en que las moléculas tienen que moverse a través de canales de dimensiones moleculares. Consecuentemente, hay una interacción constante entre las moléculas qu...

  9. Metodologías Sintéticas para la Obtención de Compuestos de Coordinación Metal-Orgánicos

    OpenAIRE

    Bazán Blau, Begoña del Pilar; Barandika Argoitia, Miren Gotzone; Calderón Casado, Ainhoa; Fidalgo Marijuan, Arkaitz; Llano Tomé, Francisco; Urtiaga Greaves, Miren Karmele; Arriortua Marcaida, María Isabel

    2016-01-01

    Comunicación a congreso (póster): Reunión conjunta de la Sociedad Española de Mineralogía y la Sociedad Española de Arcillas (SEM-SEA 2012), Bilbao 27-30 de junio 2012. La síntesis de compuestos híbridos orgánicos-inorgánicos o metal-organic framework (MOF) ha atraído un interés especial durante las últimas dos décadas, debido a la posibilidad de obtener una gran variedad de estructuras de interés para su empleo en aplicaciones relacionadas con los materiales porosos, como las zeolitas o e...

  10. WEED CONTROL IN GENETICALLY MODIFIED GLYPHOSATE-TOLERANT SOYBEAN MANEJO DE PLANTAS DANINHAS EM SOJA GENETICAMENTE MODIFICADA TOLERANTE AO GLYPHOSATE

    Directory of Open Access Journals (Sweden)

    Júlio Cezar Durigan

    2011-04-01

    convencionais, exigem, além do controle químico, a adoção de outras estratégias de manejo de plantas daninhas. Objetivou-se, com este trabalho, avaliar o controle químico de plantas daninhas, em soja geneticamente modificada (transgênica tolerante ao herbicida glyphosate associado a coberturas vegetais, na entressafra. O experimento foi instalado em área experimental da FCAV/Unesp, Jaboticabal (SP. O delineamento experimental foi o de blocos ao acaso, em esquema de parcelas subdivididas, com quatro repetições. Nas parcelas, foram avaliadas as coberturas vegetais de Brachiaria brizantha (braquiarão cv. Marandu, Pennisetum americanum (milheto forrageiro cv. BN2 e vegetação espontânea, e, nas subparcelas, os herbicidas glyphosate, chlorimuron - ethyl + lactofen em mistura e fluazifop-p-butyl em aplicação sequencial, além de duas testemunhas sem aplicação. A cobertura com braquiarão contribuiu para o controle químico, exercendo supressão das plantas daninhas. A aplicação única de 720 g e.a. ha-1 de glyphosate, independentemente da cobertura vegetal utilizada na entressafra, foi suficiente para o controle adequado de Acanthospermum hispidum, Alternanthera tenella, Amaranthus sp., Bidens pilosa, Xanthium strumarium, Cenchrus echinatus, Digitaria sp. e Eleusine indica, com resultados similares ao tratamento (chlorimuron-ethyl + lactofen + fluazifop-p-buthyl. Comparados à testemunha capinada, os herbicidas testados não afetaram a altura das plantas, massa seca da parte aérea, massa de 100 grãos e a produtividade de grãos. As plantas de soja crescidas sobre os resíduos vegetais de braquiarão e milheto forrageiro apresentaram maior altura, porém, nenhuma outra característica avaliada na cultura foi influenciada pelas coberturas.

    PALAVRAS-CHAVE: Brachiaria brizantha; Pennisetum americanum; plantio direto

  11. Estudio de libertad de operación para una línea genéticamente modificada de papa (Solanum tuberosum L.

    Directory of Open Access Journals (Sweden)

    Alejandro Chaparro-Giraldo

    2014-01-01

    Full Text Available Título en ingles: Study of freedom to operate for a genetically modified potato (Solanum tuberosum L. line Título corto: Libertad de operación para papa GM Resumen: Durante el desarrollo de los productos biotecnológicos son utilizados materiales y procesos, que pueden estar protegidos por derechos de propiedad intelectual. Para evitar problemas legales en su comercialización, se deben realizar estudios de libertad de operación. Este estudio se realizó sobre una línea genéticamente modificada (GM de papa (Solanum tuberosum L. derivada de la variedad Pastusa Suprema, que expresa el gene Cry1Ac de Bacillus thuringiensis, desarrollada por la Corporación de Ciencias Biológicas y la Universidad Nacional de Colombia, Sede Medellín. El punto de partida, fue la deconstrucción del producto, cuyo resultado fue la lista de materiales y procesos usados en el desarrollo del producto. Se buscaron en bases de datos nacionales e internacionales de acceso público, las solicitudes de patentes y patentes relacionadas. En el nivel internacional, se encontraron cuatro solicitudes de patentes y dieciocho patentes relacionadas, la mayoría de las cuales, no han sido solicitadas en Colombia. En el nivel nacional, se encontraron 13 solicitudes de patentes, que han caducado, han sido negadas, abandonadas, desistidas, o están en requerimiento. Se encontró que la variedad tiene registro comercial, pero no título de obtentor. También se examinaron documentos de las instituciones participantes, que contuvieran cláusulas sobre propiedad intelectual, y otros documentos de interés, como los acuerdos de transferencia de materiales (ATM. Se concluye que la libertad de operación puede estar afectada más por problemas detectados en los ATM y en la complejidad de los acuerdos interinstitucionales suscritos, que por los derechos de propiedad intelectual. Palabras clave: Derechos de propiedad intelectual, biotecnología, cultivos transgénicos. Abstract:

  12. Comparação de parâmetros periodontais após utilização de contenção ortodôntica com fio trançado e contenção modificada Comparison of periodontal parameters after the use of orthodontic multi-stranded wire retainers and modified retainers

    Directory of Open Access Journals (Sweden)

    Marlice Azoia Lukiantchuki

    2011-08-01

    Full Text Available OBJETIVO: o presente estudo teve como objetivo comparar dois tipos de contenções ortodônticas fixas, em relação a parâmetros periodontais estabelecidos. A contenção com fio trançado é a mais comumente utilizada e a contenção modificada apresenta dobras que têm a finalidade de permitir o livre acesso do fio dental às áreas interproximais. MÉTODOS: para esse estudo cruzado, foram selecionados 12 voluntários que utilizaram, por 6 meses, A Contenção com fio trançado e B Contenção modificada - sendo essas fixadas em todos os dentes do segmento anterior. Após esse período experimental, foram feitas as seguintes avaliações: Índice de Placa Dentária, Índice Gengival, Índice de Cálculo Dentário e Índice de Cálculo ao longo do fio de contenção. Os voluntários também responderam a um questionário com relação à utilização, conforto e higienização das contenções. RESULTADOS: foi observado que o índice de placa e o índice gengival foram maiores nas faces linguais (pOBJECTIVE: The objective of the present study was to compare two types of fixed orthodontic retainers (a multi-stranded wire retainer and a modified retainer in relation to established periodontal parameters. The multi-stranded wire retainer is commonly used, and the modified retainer has bends to enable free access of dental floss to interproximal areas. METHODS: For this crossover study, 12 volunteers were selected and used the following retainers for six months: (A a multi-stranded wire retainer and (B a modified retainer. Both retainers were fixed to all anterior lower teeth.After this experimental period, the following evaluations were made: Dental Plaque Index, Gingival Index, Dental Calculus Index and Retainer Wire Calculus Index. The volunteers also responded to a questionnaire about the use, comfort and hygiene of the retainers. RESULTS: It was observed that the plaque index and the gingival index were higher on the lingual surface (p<0

  13. Weed control, biomass and microbial metabolism of soil depending on the application of glyphosate and imazethapyr on crop soybeansControle de plantas daninhas, biomassa e metabolismo microbiano do solo em função da aplicação de glifosato ou imazetapir na cultura da soja

    Directory of Open Access Journals (Sweden)

    Dirceu Agostinetto

    2011-08-01

    Full Text Available Studied the weed control and the changes of biomass and microbial soil properties at crop cultivated both genetically modified and non altered soybeans because of glyphosate or imazethapyr herbicide applications. Soybean cultivations were tested (BRS 244RR, genetically modified and BRS 154, non modified and herbicides (glyphosate and imazethapyr, and control treatment with weed. Variables were evaluated for phytotoxicity to the crop, control of Raphanus raphanistrum (wild radish, Digitaria sp. (crabgrass and Brachiaria plantaginea (alexsandregrass, total organic carbon (TOC, microbial biomass carbon (MBC, basal respiration (BR and metabolic quocient (QCO2. The herbicide glyphosate, applied as a single dose or sequentially, effectively controls the weeds wild radish, crabgrass and alexsandregrass and increases microbial activity, basal respiration and metabolic quocient. The microbial metabolism was not affected by the fact that the genotype or not genetically modified, but the use of the herbicide glyphosate.Estudou-se o controle de plantas daninhas, as variações da biomassa e do metabolismo microbiano do solo em áreas cultivadas com soja geneticamente modificada e não modificada, em função da aplicação dos herbicidas glifosato ou imazetapir. Testaram-se cultivares de soja (BRS 244RR, geneticamente modificada e BRS 154, não modificada e herbicidas (glifosato e imazetapir, e tratamento controle com capina. Como variáveis foram avaliadas a fitotoxicidade à cultura, controle de Raphanus raphanistrum (nabo, Digitaria sp. (milhã e Brachiaria plantaginea (papuã, teores de carbono orgânico total (COT, carbono da biomassa microbiana (CBM, respiração basal (RB e quociente metabólico (QCO2. O herbicida glifosato, aplicado em dose única ou seqüencial, controla eficientemente as plantas daninhas nabo, milhã e papuã, e aumenta a atividade microbiana, a taxa de respiração basal e o quociente metabólico. O metabolismo microbiano do solo

  14. Comparative study of the stability of free and modified papain incorporated in topical formulations

    Directory of Open Access Journals (Sweden)

    Claudinéia Aparecida Sales de Oliveira Pinto

    2011-12-01

    Full Text Available Papain is an enzyme used in topical formulations as a proteolytic debriding agent for the treatment of open, extensive wounds and burnings. It is also employed as an enhancer for cutaneous permeation of active compounds, chemical peeling and as a progressive depilatory agent. The stability of formulations containing enzymes is not easy. In this research, papain was modified with polyethylene glycol in order to increase the stability of the formulations. The comparative Normal Stability Testing of the topical formulations containing unmodified and modified papain showed that the modified variety presented with a differentiated profile under the adopted temperature conditions (5.0 ± 1.0 °C; 22.0 ± 2.0 °C; 40.0 ± 2.0 °C. The most suitable condition for non-modified papain were 5.0 ± 1.0 °C and, for modified papain, they were 22.0 ± 2.0 °C. These results confirmed the higher stability of modified papain compared to free papain, as well as its potential to be applied in topical formulations.A papaína é uma enzima utilizada em formulações tópicas como agente proteolítico debridante no tratamento de lesões abertas de grande extensão e queimaduras. É, também, empregada na pele íntegra como agente promotor da permeação cutânea de princípios ativos, peeling químico e como agente depilatório progressivo. A estabilidade de formulações contendo enzimas não é facilmente alcançada. No presente trabalho realizou-se a modificação da enzima com polietilenoglicol, visando maior estabilidade das formulações. A realização do Teste Estabilidade Normal comparativo entre as formulações contendo as formas da enzima não modificada e modificada demonstrou que a última apresentou um perfil de estabilidade diferenciado, nas diferentes condições (5,0 ± 1,0 °C; 22,0 ± 2,0 °C; 40,0 ± 2,0 °C. A condição de 5,0 ± 1,0 °C foi a mais adequada para a formulação contendo papaína não modificada enquanto a 22,0 ± 2,0 °C foi

  15. Deformidade de Sprengel: tratamento cirúrgico pela técnica de green modificada Sprengel's deformity: surgical correction by a modified green procedure

    Directory of Open Access Journals (Sweden)

    Sandro da Silva Reginaldo

    2009-06-01

    Full Text Available OBJETIVO: Demonstrar os resultados estéticos e funcionais de pacientes submetidos à correção cirúrgica de escápula alta congênita - deformidade de Sprengel - por uma modificação da técnica de Green, bem como avaliar o grau de satisfação dos pacientes e as complicações da técnica utilizada. MÉTODOS: Foram avaliados nove pacientes operados pela técnica de Green modificada, no período de setembro de 1993 a abril de 2008. Como modificação da técnica original foram realizados descolamento muscular subperiosteal, ressecção apenas da porção súpero-medial da escápula e, em vez da utilização de tração esquelética, optou-se pela fixação com fio de aço subcutâneo da porção medial da espinha da escápula à crista ilíaca posterior contralateral. A idade média dos pacientes foi de sete anos e três meses. O seguimento pós-operatório médio foi de três anos e sete meses. RESULTADOS: Houve incremento médio na elevação de cerca de 39º (variando de 0º a 80º . Segundo a classificação de Cavendish, obteve-se a melhora estética de dois graus em oito casos e de três graus em um. Todos os pacientes ficaram satisfeitos com o resultado. CONCLUSÕES: Os pacientes com deformidade de Sprengel submetidos a tratamento cirúrgico por meio de uma modificação da técnica de Green, com fixação da escápula na crista ilíaca posterior contralateral em vez de se utilizar tração esquelética, apresentaram melhora tanto funcional como estética; todos os pacientes e/ou familiares ficaram satisfeitos e as complicações relacionadas com a técnica cirúrgica não interferiram no resultado final.OBJECTIVE: To evaluate the cosmetic and functional results of patients submitted to surgical correction of Congenital High Scapula (Sprengel's Deformity using modified Green's Procedure, as well as patients' satisfaction and complications. METHODS: Nine patients submitted to surgical treatment from September 1993 to April 2008 have

  16. Efecto de la adición mineral cal- zeolita sobre la resistencia a la compresión y la durabilidad de un hormigón Effect of lime- zeolite binder on compression strength and durability properties of a concrete

    Directory of Open Access Journals (Sweden)

    Juan José Dopico Montes de Oca

    2009-08-01

    Full Text Available La práctica internacional reporta una creciente utilización de los hormigones de altas resistencias, con excelentes resultados en la durabilidad, relacionado con la obtención de una matriz cementicia muy densa, a partir del empleo de altos volúmenes de adiciones minerales muy finas, tales como las cenizas volantes, la microsílice, el metacaolín y otros materiales. Para los países emergentes, entre los cuales se ubica Cuba, el uso de estas adiciones puzolánicas resultan una solución relativamente costosa, dado los altos precios de importación de estos materiales puzolánicos, de ahí la utilidad de usar las fuentes nacionales de puzolanas disponibles de probada reactividad, como sustituías parciales de los contenidos de Cemento Portland Ordinario (CPO en las mezclas de hormigón, sin que se vean afectadas significativamente sus propiedades. El presente trabajo muestra la influencia del nivel de sustitución de los contenidos de Cemento Portland por adición mineral cal- puzolana, en combinación con superplastificante, en el comportamiento de la resistencia a la compresión y la durabilidad de un hormigón. Varios niveles de sustitución de CPO son evaluados, utilizando toba zeolítica como puzolana. Los resultados obtenidos corroboran la posibilidad del reemplazo de altos volúmenes de CPO por aglomerante cal-zeolita, sin que se afecten la resistencia a compresión requerida y su comportamiento ante la acción del ingreso del ion cloruro y la carbonatación.The international construction practice reports a remarkable use and development of high performance concretes, with excellent results in the durability properties, associated with a very dense cement matrix, defined from the use of high volumes of very fine minerals additions, such as, fly ash, silica fume, metakaolin and other fine powders. For the developing countries, among others Cuba, the use of these pozzolanic additions are relatively expensive, given for the high import

  17. Operação de Blalock-Taussig modificada para o tratamento paliativo de cardiopatias congênitas com hipofluxo pulmonar Blalock-Taussig operation for palliative treatment of congenital heart disease with low pulmonary flow

    Directory of Open Access Journals (Sweden)

    Miguel A Maluf

    1995-09-01

    Full Text Available De janeiro de 1990 a novembro de 1994, 72 pacientes portadores de cardiopatias congênitas com hipofluxo pulmonar foram submetidos à operação de Blalock-Taussig. A idade variou entre 2 dias e 11 anos (M:9,0 meses; 44 (61,1% eram do sexo masculino e 28 (38,8% do feminino; 38 (52,8% casos portadores de tétrade de Fallot; 7 (9,7% atresia pulmonar com septo interventricular íntegro (AP c/ SIVI; 6 (8,4% transposição das grandes artérias (TGA + estenose pulmonar (EP; 6 (8,4% atresia tricúspide (AT + EP; 6 (8,4% dupla via de entrada (DVE do ventrículo direito (VD ou ventrículo esquerdo (VE + (EP; 3 (4,2% transposição corrigida das grandes artérias (TCGA + comunicação interventricular (CIV + EP; 2 (2,7% dupla via de saída (DVS de VD ou VE + EP; 2 (2,7% defeito septal atrioventricular (DSAV + EP; 2 (2,7% isomerismo direito (D ou (E + EP. Os critérios de indicação foram: a neonatos com cardiopatias "dueto dependente"; b lactentes com piora de cianose ou crise de hipoxia; c crianças durante a infância com cardiopatias sem chance de uma correção biventricular. A técnica empregada foi a operação de Blalock-Taussig modificada, interpondo prótese entre artéria subclávia e artéria pulmonar. A prótese de Polytetrafluoroethylene (PTFE foi usada em 69 (94,5% casos, veia umbilical em 3 (4,1% casos e artéria mamária bovina em 1 (1,4% caso. Durante o ato operatório foi administrada dose única de heparina (1mg x kg peso, não sendo neutralizada no pós-operatório (PO e no seguimento tardio, dispensado o uso de anticoagulantes ou antiagregantes plaquetários. Houve 8 (11,1% óbitos no PO imediato: 5 (6,9% casos por obstrução da prótese (3 foram reoperados, 2 (2,7% casos por morte súbita (AP c/ SIVI e 1 (1,3% devido a processo infeccioso pulmonar. A obstrução da prótese como principal causa de óbito esteve diretamente relacionada à anatomia dos vasos (calibre da artéria subclávia e pulmonar e ou problemas de técnica cir

  18. Fungos micorrízicos nativos e Glomus clarun no rendimento de trevo vesiculoso cultivado em condições naturais e modificadas pela calagem e aplicação de fósforo Glomus clarun and native mycorrhizal fungi on yield of Trifolium spp. cultivated under natural and modified soil contitions with addition by phosphorus and liming

    Directory of Open Access Journals (Sweden)

    Antonio Carlos dos Santos Pessoa

    1997-03-01

    Full Text Available Em experimento desenvolvido na casa de vegetação na UFSM-RS, avaliou-se o efeito da introdução de fungos micorrizicos arbusculares (fMA Glomus clarum e nativos no rendimento de massa seca (MS e absorção de P pelo trevo vesiculoso (Trifolium spp. e verificou-se a compatibilidade entre a espécie introduzida e os fMA nativos ocorrentes no solo estudado. Os tratamentos/oram constituídos defatorial 4x2x2 com quatro níveis de fMA: G. clarum, fungos nativos, mistura de ambas as populações e controle sem inoculação de fMA: com dois valores de pH: 4,4 e 5,4 e com dois níveis de fósforo disponível (Mehlich l: 6 e ISmg/kg de solo. A introdução de G. clarum isoladamente ou em conjunto com fMA nativos, na condição de pH 4,4, e em baixa disponibilidade de P, aumentou o rendimento de MS e absorção de P. Em disponibilidade intermediária de P (l5mg/kg de solo e pH 5,4 não ocorreu diferença entre os tratamentos inoculados com fMA, mas destes ocorreu diferença para o tratamento sem inoculação, evidenciando a dependência do trevo pela micorrizaçâo. Tratamentos inoculados com G. clarum apresentaram maiores rendimentos de MS, absorção de P, colonização micorrizica e esporulação, mostrando que a introdução dessa espécie pode ser viável quando espécies nativas não são eficientes para a cultura ou tornam-se ineficientes quando a fertilidade do solo é modificada por aplicação de P e/ou calagem.The experiment v/as conducted under greenhouse condition at the University of Santa Maria, RS, Brazil. The objectives were to evaluate the introduction of arbuscular mycorrhizalfúngi (AMF Glomus clarum and natives fungi on the phosphorus uptake and dry matter (DM production from Trifolium spp. and Io verify lhe compatibilily between introduced specie and lhe nativo AMF occurence in lhe studied soil. The treatments was constituled of 4x2x2 factorial withfour AMF leveis: G. clarum, AMf native, mixture of both populations of AMF

  19. Next nature : nature changes along with us

    NARCIS (Netherlands)

    Mensvoort, van K.M.; Grievink, H.J.

    2011-01-01

    We debate saving nature, we dream about escaping to nature, but rarely do we ask "What is nature?". The Next Nature book radically shifts your notion of nature. Where technology and nature are traditionally seen as opposed, they now appear to merge or even trade places. With our urge to design our

  20. Modificação de fibra de carbono com PBLH e sua utilização em compósitos com resina epoxídica Hydroxyl-terminated polybutadiene-grafted carbon fiber in epoxy resin-based composites

    Directory of Open Access Journals (Sweden)

    Fábio L. Barcia

    1999-06-01

    Full Text Available Fibras de carbono contendo 1,4 e 2,1mmol/g de grupos carboxila e hidroxila fenólica, respectivamente, foram modificadas através de reação com TDI, resultando em fibras contendo 3,1 mmol/g de grupos isocianato. A introdução de grupos isocianato na superfície da fibra tornou possível a sua modificação com polibutadieno líquido hidroxilado. Fibras de carbono modificadas e não modificadas foram empregadas na preparação de compósitos com resina epoxídica, sendo observado um aumento considerável de resistência ao impacto em compósitos constituídos de fibras de carbono enxertadas com PBLH, devido, provavelmente, à natureza elastomérica da interface e à melhor adesão interfacial.Carbon fibers containing 1,4 e 2,1 mmol/g of carboxyl and phenolic hydroxyl groups, respectively, were modified through the reaction with TDI. The presence of isocyanate groups at the fiber surface made possible the fiber modification with hydroxyl terminated polybutadiene (HTPB. These modified and unmodified carbon fibers were employed in the preparation of epoxy resin-based composites. A substantial improvement in the impact properties was observed in the composites with HTPB-grafted carbon fibers when compared to unmodified carbon fibers. These results may be attributed to a higher interfacial adhesion promoted by reactions between the functional groups present at the modified carbon fiber surface and the epoxy matrix.

  1. Nature and nature values in organic agriculture

    DEFF Research Database (Denmark)

    Hansen, Lene; Noe, Egon; Højring, Katrine

    2006-01-01

    The relationship between agriculture and nature is a centra issue in the current agricultural debate. Organic farming has ambitions and a special potential in relation to nature. Consideration for nature is part of the guiding principals of organic farming and many organic farmers are committed...... to protecting natural qualities. However, the issue of nature, landscape, and land use is not straightforward. Nature is an ambiguous concept that involves multiple interests and actors reaching far beyond farmers. The Danish research project ......

  2. Qualitative and quantitative assessment of genetically modified soy in enteral nutrition formulas by polymerase chain reaction based methods Avaliação qualitativa e quantitativa de soja geneticamente modificada em fórmulas de nutrição enteral

    Directory of Open Access Journals (Sweden)

    Natália Eudes Fagundes de Barros

    2010-02-01

    Full Text Available OBJECTIVE: The aim of this work was to investigate the occurrence of Roundup Ready soybean in enteral nutrition formulas sold in Brazil. METHODS: A duplex Polymerase Chain Reaction based on the amplification of the lectin gene and the construction of the recombinant deoxyribonucleic acid of transgenic glyphosate-tolerant soybean (35S promoter and chloroplast transit peptide gene was performed in order to analyze the deoxyribonucleic acid obtained from nine soy protein isolate-containing formulas. RESULTS: Despite the highly processed nature of the food matrices, amplifiable deoxyribonucleic acid templates were obtained from all tested samples, as judged by the amplification of the lectin gene sequence. However, amplicons relative to the presence of Roundup Ready soybean were restricted to one of the nine enteral nutrition formulas analyzed as well as to the soybean reference powder, as expected. Quantitative analysis of the genetically modified formula by real-time Polymerase Chain Reaction showed a content of approximately 0.3% (w/w of recombinant deoxyribonucleic acid from the Roundup Ready soybean. CONCLUSION: The results show that one of the formulas contained genetically modified soy, pointing to the need of regulating the use of transgenic substances and of specific labeling in this product category.OBJETIVO: Investigar a ocorrência de soja transgênica em fórmulas de suporte nutricional comercializadas no Brasil. MÉTODOS: Foi desenvolvido o método da reação em cadeia da polimerase duplex, com base na amplificação do gene na lectina, e na construção do ácido desoxirribonucléico recombinante da soja transgênica tolerante a glifosato (promotor 35S e gene de peptídeo de trânsito de cloroplasto, a fim de avaliar o ácido desoxirribonucléico extraído a partir das nove fórmulas contendo isolado protéico de soja. RESULTADOS: Apesar do alto grau de processamento aos quais os produtos avaliados foram submetidos, foi poss

  3. Árvores geneticamente modificadas: técnicas, aplicações, riscos e os potenciais impactos associados a sua utilização Genetically modified trees: techniques, applications, risk and potential impacts associated with their use

    Directory of Open Access Journals (Sweden)

    Erlon Barbosa Valdetaro

    2011-03-01

    Full Text Available

    As espécies florestais possuem grande importância, oferecendo diversos produtos madeireiros e não madeireiros fundamentais para a sociedade. Neste contexto, a busca de novas tecnologias capazes de promover incremento na produtividade das florestas comerciais tem merecido grande atenção, sendo que a biotecnologia tem contribuído substancialmente para isso. Este ramo da ciência pode promover a modificação direta do genoma de um organismo alvo, por meio da análise e manipulação do DNA ou pela inserção de fragmentos do mesmo com função conhecida e, deste modo, alcançar características previamente desejadas, tais como resistência a doenças e ataques de pragas, redução do teor de lignina na madeira e geração de plantas tolerantes a diferentes tipos de estresse. Esta revisão objetiva relatar técnicas para a geração de árvores geneticamente modificadas, aplicações da transformação genética em essências florestais, riscos do uso desta tecnologia e seus potenciais impactos ambientais.

    doi: 10.4336/2011.pfb.31.65.51

    Forest species have great economic and social importance, offering various products as wood and non-timber fundamental to society. In this context, the search for new technologies that promote increase in productivity of commercial forests has received special attention and biotechnology has contributed substantially to this. This branch of science can promote direct modification of the genome of a target organism, through the analysis and manipulation of DNA genome or by insertion of fragments of the same with known function and thus to achieve desired characteristics, such as resistance to diseases and pests, lignin reduction in wood and generation of plants tolerant to different kinds of stresses. This review aims at reporting techniques for the generation of genetically modified trees, applications of genetic transformation in forest species, risks of using this technology and its potential

  4. Potencial de cruzamento natural entre o arroz transgênico resistente ao herbicida glufosinato de amônio e o arroz daninho Outcrossing potential of glufosinate-resistant rice to red rice

    Directory of Open Access Journals (Sweden)

    J.A. Noldin

    2002-08-01

    Full Text Available A utilização de cultivares de arroz irrigado resistentes a herbicidas não-seletivos, como o glufosinato de amônio, pode se constituir numa alternativa de controle de arroz daninho em lavouras de arroz irrigado. O objetivo deste trabalho foi avaliar a taxa e o sentido do cruzamento natural entre plantas de uma linhagem modificada geneticamente para resistência ao herbicida glufosinato de amônio (arroz GM e ao arroz daninho. A taxa de cruzamento natural entre o arroz GM como receptor feminino e o arroz daninho como doador de pólen foi de 0,22 e 0,02%, respectivamente para os ecótipos de arroz daninho com glumas de cor palha e com glumas pretas. No caso inverso, quando o arroz daninho foi o receptor feminino e o arroz GM o doador de pólen, a taxa de cruzamento foi de 0,26 e 0,14%, para o arroz daninho com glumas palha e com glumas pretas, respectivamente. Os resultados deste estudo evidenciaram que ocorreu cruzamento natural entre o arroz GM e o arroz daninho em percentuais que variaram de 0,14 e 0,48%, respectivamente para o arroz preto e para o arroz vermelho. A fim de minimizar a possibilidade de hibridação, medidas de controle eficientes devem ser adotadas no sentido de prevenir a coincidência de floração das plantas de arroz daninho com a das plantas de arroz GM cultivado.The broad spectrum non-selective herbicide ammonium glufosinate, combined with genetically modified glufosinate-resistant rice cultivars (GM rice, may comprise a rice weed control system for red rice and other weeds that infest Brazilian rice fields. The objective of this study was to evaluate the potential for outcrossing and gene flow of GM rice to red rice. Natural outcrossing between adjacent field plots (1 m x 1 m was measured during the 1999/2000 production season in Brazil. The outcrossing rate of the GM rice as the female parent to red rice, as the pollen donor, was 0.22% for strawhull and 0.02% for the blackhull red rice, respectively. In the reciprocal

  5. The Nature of Natural Hazards Communication (Invited)

    Science.gov (United States)

    Kontar, Y. Y.

    2013-12-01

    Some of the many issues of interest to natural hazards professionals include the analysis of proactive approaches to the governance of risk from natural hazards and approaches to broaden the scope of public policies related to the management of risks from natural hazards, as well as including emergency and environmental management, community development and spatial planning related to natural hazards. During the talk we will present results of scientific review, analysis and synthesis, which emphasize same new trends in communication of the natural hazards theories and practices within an up-to-the-minute context of new environmental and climate change issues, new technologies, and a new focus on resiliency. The presentation is divided into five sections that focus on natural hazards communication in terms of education, risk management, public discourse, engaging the public, theoretical perspectives, and new media. It includes results of case studies and best practices. It delves into natural hazards communication theories, including diffusion, argumentation, and constructivism, to name a few. The presentation will provide information about: (1) A manual of natural hazards communication for scientists, policymakers, and media; (2) An up-to-the-minute context of environmental hazards, new technologies & political landscape; (3) A work by natural hazards scientists for geoscientists working with social scientists and communication principles; (4) A work underpinned by key natural hazards communication theories and interspersed with pragmatic solutions; (5) A work that crosses traditional natural hazards boundaries: international, interdisciplinary, theoretical/applied. We will further explore how spatial planning can contribute to risk governance by influencing the occupation of natural hazard-prone areas, and review the central role of emergency management in risk policy. The goal of this presentation is to contribute to the augmentation of the conceptual framework

  6. Regularities, Natural Patterns and Laws of Nature

    Directory of Open Access Journals (Sweden)

    Stathis Psillos

    2014-02-01

    Full Text Available  The goal of this paper is to sketch an empiricist metaphysics of laws of nature. The key idea is that there are regularities without regularity-enforcers. Differently put, there are natural laws without law-makers of a distinct metaphysical kind. This sketch will rely on the concept of a natural pattern and more significantly on the existence of a network of natural patterns in nature. The relation between a regularity and a pattern will be analysed in terms of mereology.  Here is the road map. In section 2, I will briefly discuss the relation between empiricism and metaphysics, aiming to show that an empiricist metaphysics is possible. In section 3, I will offer arguments against stronger metaphysical views of laws. Then, in section 4 I will motivate nomic objectivism. In section 5, I will address the question ‘what is a regularity?’ and will develop a novel answer to it, based on the notion of a natural pattern. In section 6, I will raise the question: ‘what is a law of nature?’, the answer to which will be: a law of nature is a regularity that is characterised by the unity of a natural pattern.

  7. Zeolite and wollastonite synthesis from rice hull ash; Sintese de zeolitas e wolastonita a partir da cinza da casca de arroz

    Energy Technology Data Exchange (ETDEWEB)

    Fernandes, Alberto de Andrade

    2006-07-01

    Rice hull ash (RHA) is a industry scrap rich in amorphous silica. A simple and low-energy cost method for the extraction of this silica was researched. A low level of impurity and high reactivity material was produced, which is appropriate for the synthesis of zeolites and wollastonite (CaSiO{sub 3}). The synthetic zeolites has not similar structures in nature, and they have been more and more valued in the market due to their purity and efficiency in specific applications like ion exchange, molecular sieve and catalysis areas. High purity wollastonite has many applications in manufacturing and agriculture. The mineral wollastonite can be formed in nature in different ways; it is generally accepted two forming processes, both encompassing limestone metamorphism (heat and pressure). In this work, a new process for the synthesis of zeolites and wollastonite from RHA colloidal silica was developed. Moreover, the process is aimed at lower energy costs, fewer stages and fewer reactants consume. In this work, zeolite A used in detergent and zeolite ZSM-5, employed in the petrochemical industry due to its high selectivity in catalytic reactions and its high thermo and acid stability, were synthesized. The first step of the wollastonite synthesis was studied, with the purpose of obtaining calcium hydrosilicate. Eleven different hydrosilicates occur in the system Ca(OH){sub 2}-SiO{sub 2}-H{sub 2}O, in the second step it was annealed to form the wollastonite phase. (author)

  8. Utilización de Cromatografía Líquida de Alta Eficiencia (HPLC para determinar consumo de sustrato

    Directory of Open Access Journals (Sweden)

    Agostina Romero

    2016-08-01

    Full Text Available La incorporación de diferentes tipos de desechos industriales y hogareños, y muy especialmente de agroquímicos, son los principales motivos que pueden originar la contaminación de los ambientes naturales, esencialmente los cursos y cuerpos de agua natural. Los efectos nocivos pueden minimizarse merced a la fotodegradación, proceso que puede favorecerse por la adsorción de los contaminantes a arcillas naturales o modificadas con nanopartículas. En este último caso, para el estudio y seguimiento de la cinética de degradación de los contaminantes una técnica normalmente empleada es la cromatografía. En el caso particular del fenol, es posible aplicar la cromatografía líquida de alta eficiencia (HPLC, High Performance Liquid Chromatography. El presente trabajo se enfocó en la optimización de una técnica para el seguimiento de la adsorción y degradación de compuestos orgánicos, en particular fenol, mediante HPLC. Empleando un equipo Shimadzu CBM-20A, se obtuvo la mayor eficiencia con una corrida isotérmica a 25ºC en columna Phenomenex Luna C18 (2 de 250 mm de longitud y 4,6mm de diámetro interno usando como fase móvil una mezcla 50/50 (V/V acetonitrilo y agua ultrapura con un flujo de 1mL/min. Se empleó un detector espectrofotométrico UV (270 nm. La aplicación de la técnica con estos parámetros permitirán estudiar convenientemente los mecanismos de la fotodegradación del fenol adsorbido a arcillas modificadas con nanopartículas.

  9. Pilot study of iron and manganese removal from Mexican drinking water supply sources; Estudio piloto para remocion de fierro y manganeso en las fuentes de abastecimiento de Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Simeonova, Verguinia Petkova; Mintchev, Mintcho Lliev; Rivera, Maria Lourdes [Instituto Mexicano de Tecnologia del Agua, Jiutepec, Morelos (Mexico)

    1999-08-01

    This study demonstrates the efficiency of a technique for manganese removal through adsorption-oxidation on zeolite. Several Mexican groundwater sources were selected for pilot installations. The results show that the final iron and manganese concentrations are within the limits set in the Official Mexican Standard, NOM-127-SSA1, referring to drinking water. An analysis was made of the effect of the operating rate and the granule size of the filtering material on iron and manganese removal and of calcium and magnesium salts associated with hardness. Zeolite covered with manganese precipitates was highly selective for iron and manganese; this made the treatment of groundwater with high iron and manganese concentrations possible, even in the presence of hardness and alkalinity. A description is given of the procedures to prepare the material and regenerate its filtration capacity without interrupting the filtration process. [Spanish] El presente estudio comprueba la eficiencia de la tecnica propuesta para la remocion de manganeso por adsorcion-oxidacion sobre zeolita a traves de estudios piloto en varias fuentes subterraneas de Mexico. Los resultados demuestran que la concentracion de fierro y manganeso en el agua producida cumple con la Norma Oficial Mexicana NOM-127-SSA1 para el consumo humano en todo los casos estudiados. Fueron analizadas la influencia de la tasa de operacion y la granulometria del material filtrante sobre el grado de remocion de fierro y manganeso, asi como el efecto de las sales de calcio y magnesio que originan la dureza del agua. Durante la experimentacion se comprobo que la zeolita recubierta con los precipitados de manganeso es altamente selectiva respecto al fierro y manganeso, lo que permite tratar el agua de las fuentes subterraneas con elevada concentracion de Fe y Mn en presencia de alta dureza y alcalinidad. En el articulo se describen los procedimientos para la preparacion del material filtrante y la regeneracion de su capacidad sin

  10. 187. 31 Años de seguimiento de pacientes intervenidos de cirugía bono-bentall en nuestro medio

    Directory of Open Access Journals (Sweden)

    N. Miranda

    2012-04-01

    Conclusiones: La cirugía de Bono-Bentall modificada para operaciones sobre raíz y aorta ascendente y pacientes con disección aórtica aguda tipo A tiene buenos resultados en nuestro medio a corto y largo plazo, con una supervivencia a largo plazo elevada.

  11. Dyes removal of textile wastewater onto surfactant modified zeolite from coal ash and evaluation of the toxic effects; Remocao de corantes de efluente textil por zeolita de cinzas de carvao modificada por surfactante e avaliacao dos efeitos toxicos

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Patricia Cunico

    2015-07-01

    Zeolites synthesized from fly and bottom ashes and modified with hexadecyltrimethylammonium (HDTMA) were used as adsorbent to remove dyes - Solophenyl Navy (SN) and Solophenyl Turquoise (ST) and their hydrolysed forms Solophenyl Navy Hydrolysed (SNH) and Solophenyl Turquoise Hydrolysed (STH), from simulated textile wastewater. The HDTMA-modified fly zeolite (ZMF) and HDTMA-modified bottom zeolite (ZMB) were characterized by different techniques, as X-ray fluorescence spectrometry, X-ray diffraction and scanning electron microscopy, etc. The ZMF and ZMB presented negative charge probably due to the formation of a partial bilayer of HDTMA on exchangeable active sites on the external surface of unmodified zeolite. Initial dye concentration, contact time and equilibrium adsorption were evaluated. The adsorption kinetic for SN, ST, SNH and STH onto the zeolites followed the pseudo second-order model. The equilibrium time was 20 min for SN and ST and 30 min for SNH and STH, respectively. Langmuir, Freundlich and Temkin models were applied to describe the adsorption isotherms. Adsorption of the dyes were best described by the Langmuir model, with exception to SN/ZPM, SNH/ZPM and SNH/ZLM systems that followed Freundlich model. The maximum adsorption capacities were 3,64; 3,57; 2,91 e 4,93 for SN, ST, SNH e STH by ZLM, respectively and 0,235; 0,492; 1,26 e 1,86 by ZPM, in this order. The best performance for hydrolyzed dyes has been attributed to reduction of the size of dyes molecules during the hydrolysis process. Acute toxicity of the dyes to a different organism were evaluated by different test-organisms. Waterflea, Ceriodaphnia dubia showed EC50 value of 1,25; 54,5; 0,78 and 2,56 mgL{sup -1} for SN, ST, SNH and STH, respectively. The plant Lemna minor showed EC50 values of 18,9; 69,4; 10,9 and 70,9 mgL{sup -1} for SN, ST, SNH and STH, respectively. Midges larvae of Chironomus tepperi showed EC50 values of 119 and 440 mgL{sup -1} for SN and ST, respectively. Regarding the adsorption process, acute effects were substantially reduced after adsorption treatment of aqueous solution with SN and ST by ZMF, as well as their hydrolysed forms, showing no toxicity after removal of 100% of colour. After treatment with ZPM there was an increase of the toxicity, with exception of SHN and STH dyes that do not show toxicity after the treatment. Toxicity Identification Evaluation tests (TIE) were realized in order to identify what substances were causing the observed toxicity for the SN, ST and the leached of ZMF and ZMB. The acute effects were significantly reduced after manipulation with Solid-Phase Extraction (SPE) and Ethylenediaminetetraacetic acid (EDTA) for the leached of ZMB and ZMF. The dyes showed reduced in the toxicity after manipulation with EDTA indicating that the toxicants are mostly cationic metals. (author)

  12. Nature and nature values in organic agriculture

    DEFF Research Database (Denmark)

    Hansen, Lene; Noe, Egon; Højring, Katrine

    2006-01-01

    The relationship between agriculture and nature is a centra issue in the current agricultural debate. Organic farming has ambitions and a special potential in relation to nature. Consideration for nature is part of the guiding principals of organic farming and many organic farmers are committed...

  13. Natural radiation; A radiacao natural

    Energy Technology Data Exchange (ETDEWEB)

    Feliciano, Vanusa Maria Delage

    2016-07-01

    Cosmic radiation, as well as cosmogenic radiation, terrestrial radiation, radon and thorium are introduced in this chapter 3. The distribution of natural radiation sources is treated, where the percentage distribution of the contribution relative to exposure to radiation from natural and artificial sources is also included.

  14. Alternativas bioorgánicas en la multiplicación por esquejes de Psidium guajava (L.

    Directory of Open Access Journals (Sweden)

    Pedro Jesús López Labarta

    2017-05-01

    Full Text Available Con el objetivo, de emplear diferentes estimuladores para la reproducción del guayabo por esquejes en condiciones semicontroladas, la investigación se realizó en la finca la Nueva Esperanza, perteneciente a la Cooperativa de Créditos y Servicios Fortalecida Renato Guitart del municipio Camagüey, en el período comprendido de febrero a mayo del 2016. Se contó con una cámara para la reproducción de posturas del guayabo por esquejes, la cual posee riego por microjet programado; el soporte utilizado es la zeolita con diámetro de 1 a 3 mm, empleándose un diseño completamente aleatorizado con 6 tratamientos y 3 repeticiones cada uno. Se realizó la evaluación de plantas con gemas y sin gemas, plantas con raíces, número de hojas y plantas vivas en el cultivo de la guayaba. Para el análisis estadístico, se utilizó el SSPS versión 11.5.1 con análisis de varianza de clasificación simple, aplicando los rangos múltiples de Duncan para un nivel de significación de 0,05 %. Las alternativas bioorgánicas empleadas, determinaron eficiencia positiva en los mecanismos fisiológicos en el desarrollo de las plántulas, los tratamientos que mejor comportamiento fenológico fueron el humus líquido natural más ácido indolacético, humus líquido natural más ácido fosfórico y el humus líquido fortificado.

  15. Natural Colorants: Food Colorants from Natural Sources.

    Science.gov (United States)

    Sigurdson, Gregory T; Tang, Peipei; Giusti, M Mónica

    2017-02-28

    The color of food is often associated with the flavor, safety, and nutritional value of the product. Synthetic food colorants have been used because of their high stability and low cost. However, consumer perception and demand have driven the replacement of synthetic colorants with naturally derived alternatives. Natural pigment applications can be limited by lower stability, weaker tinctorial strength, interactions with food ingredients, and inability to match desired hues. Therefore, no single naturally derived colorant can serve as a universal alternative for a specified synthetic colorant in all applications. This review summarizes major environmental and biological sources for natural colorants as well as nature-identical counterparts. Chemical characteristics of prevalent pigments, including anthocyanins, carotenoids, betalains, and chlorophylls, are described. The possible applications and hues (warm, cool, and achromatic) of currently used natural pigments, such as anthocyanins as red and blue colorants, and possible future alternatives, such as purple violacein and red pyranoanthocyanins, are also discussed.

  16. Atmosfera modificada e 1-metilciclopropeno na conservação pós-colheita de kiwis cv. Bruno Modified atmosphere and 1-methylciclopropene on postharvest conservation of kiwis cv. Bruno

    Directory of Open Access Journals (Sweden)

    Leandro Camargo Neves

    2003-12-01

    Full Text Available Neste trabalho avaliou-se, em kiwis da cv Bruno, a ação do 1-Metilciclopropeno (1-MCP, na concentração de 625 ppb, associado ou não à atmosfera modificada gerada com o emprego de embalagem de polietileno de baixa densidade (PEBD, de 22µm. Os tratamentos testados foram: T1, controle (sem embalagem e 1-MCP; T2, sem embalagem com 1-MCP; T3, com embalagem de PEBD sem 1-MCP; T4, embalagem de PEBD mais o 1-MCP, sendo após armazenados em câmara fria a - 0,5 ± 0,5 ºC e 95 ± 5% de umidade relativa (U.R.. As avaliações foram realizadas após o pré-resfriamento, aos 45 dias, 45 + 5 dias (22 ± 3ºC e 75 ± 5% de U.R., 90 dias e 90 + 5 dias (22 ± 3ºC e 75 ± 5% de U.R.. As variáveis analisadas foram: firmeza de polpa (FP, sólidos totais (ST, acidez titulável (AT, concentração de etileno e de CO2 e análise sensorial (somente ao final do experimento. A maior firmeza de polpa e acidez titulável, o menor conteúdo de sólidos totais, as menores concentrações de etileno e CO2 e a melhor aceitabilidade pelos julgadores foi obtida com os frutos acondicionadas em PEBD de 22 µm e tratadas com 1-MCP.In this work was evaluated, for kiwis cv. Bruno, the Methylcyclopropene action (1-MCP, in concentration of 625 ppb, associated or not with modified atmosphere (MA using low density polyethylene bags (LDPE of 22µm. The following treatments were tested: T1: control (no bags and 1-MCP; T2 no bags with 1-MCP; T3 LDPE bags no 1-MCP; T4 LDPE bags and 1-MCP, then they were stored in cold chamber at - 0,5 ± 0,5 ºC and 95 ± 5% of RH for 45 or 90 days. The fruits were evaluated after pre-cooling, 45 days, 45 + 5 days (22 ± 3ºC and 75 ± 5% of RH., 90 days and 90 + 5 days (22 ± 3ºC and 75 ± 5% of RH.. The parameters analyzed were: pulp firmness (PF, total solids (TS, titritable acidity (TA, ethylene and CO2 concentration, and sensorial analyzes (only in the end of the experiment. The largest pulp firmness and titritable acidity, the smaller

  17. Mother natural: Motivations and associations for consuming natural foods.

    Science.gov (United States)

    Moscato, Emily M; Machin, Jane E

    2018-02-01

    Natural is perceived as innately positive and is a widely sought-after attribute in food products. The natural food industry continues to grow in response to rising consumer demand. This qualitative study explored mothers' motivations for purchasing and consuming natural food products for themselves and their families. Mothers are an important population because of their disproportionate influence on household food consumption. We employed participant photography and a series of three weekly focus groups to derive a rich understanding of the activities surrounding and motivations behind seeking natural in everyday buying decisions. Five major themes were identified. First, natural nurtures well-being: physical, psychological, social, and emotional health. Second, natural behaves "supernaturally," allowing positive attributes to be transmitted from the source to the recipient. Third, natural is associated with authenticity, providing a sense of trust, transparency, and control. Fourth, consuming natural reinforces the socially constructed idea of a good mother. Lastly, the preference for natural does not always translate into purchase; mothers face compromises because of conflicting priorities and resources. Understanding mothers' multiple motivations provides deeper insight into the attraction for natural products. The findings have application in positioning interventions for more nutritional eating and revising regulations on the food label natural. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Super Natural II--a database of natural products.

    Science.gov (United States)

    Banerjee, Priyanka; Erehman, Jevgeni; Gohlke, Björn-Oliver; Wilhelm, Thomas; Preissner, Robert; Dunkel, Mathias

    2015-01-01

    Natural products play a significant role in drug discovery and development. Many topological pharmacophore patterns are common between natural products and commercial drugs. A better understanding of the specific physicochemical and structural features of natural products is important for corresponding drug development. Several encyclopedias of natural compounds have been composed, but the information remains scattered or not freely available. The first version of the Supernatural database containing ∼ 50,000 compounds was published in 2006 to face these challenges. Here we present a new, updated and expanded version of natural product database, Super Natural II (http://bioinformatics.charite.de/supernatural), comprising ∼ 326,000 molecules. It provides all corresponding 2D structures, the most important structural and physicochemical properties, the predicted toxicity class for ∼ 170,000 compounds and the vendor information for the vast majority of compounds. The new version allows a template-based search for similar compounds as well as a search for compound names, vendors, specific physical properties or any substructures. Super Natural II also provides information about the pathways associated with synthesis and degradation of the natural products, as well as their mechanism of action with respect to structurally similar drugs and their target proteins. © The Author(s) 2014. Published by Oxford University Press on behalf of Nucleic Acids Research.

  19. Natural gas

    Energy Technology Data Exchange (ETDEWEB)

    Fraser, J W

    1967-08-01

    This report on the natural gas industry of Canada includes: composition and uses of natural gas, production statistics, exploration and development, reserve estimates, natural gas processing, transportation, and marketing. For the Canadian natural gas industry, 1966 was a year of moderate expansion in all phases, with a strong demand continuing for sulfur and liquid hydrocarbons produced as by-products of gas processing. Value of natural gas production increased to $199 million and ranked sixth in terms of value of mineral ouput in Canada. Currently, natural gas provides over 70% of Canada's energy requirements. Proved remaining marketable reserves are estimated to be in excess of a 29-yr supply.

  20. Fluxo gênico recíproco entre cultivares de soja convencional e geneticamente modificada

    Directory of Open Access Journals (Sweden)

    Welison Andrade Pereira

    2012-02-01

    Full Text Available O objetivo deste trabalho foi determinar o fluxo gênico recíproco entre duas cultivares de soja, uma tolerante e outra sensível ao glifosato, além de aplicar estimadores para determinar a taxa de fecundação cruzada na população e o número de sementes híbridas na progênie. O experimento compôs-se de quatro blocos com 40 fileiras de soja, com 20 fileiras de cada cultivar (CD217 e CD219RR. No estádio R8, cinco fileiras, distantes 0, 5, 1, 2, 4 e 8 m da cultivar adjacente, foram colhidas, trilhadas e analisadas quanto à ocorrência de fluxo gênico. Como características marcadoras, foram utilizadas as cores da flor, hipocótilo e pubescência, e a tolerância ao glifosato. As cultivares contrastam quanto às características analisadas, cada uma condicionada por um gene com dois alelos, em interação de dominância completa. Na progênie da cultivar tolerante, a maior taxa de híbridos encontrada foi 0, 27% e, na progênie da cultivar sensível, identificou-se 0, 83%; pela hipótese do efeito diluição, as taxas de hibridação natural populacional seriam 0, 104 e 0, 388%, respectivamente. O fluxo gênico recíproco entre as cultivares CD217 e CD219RR não é o mesmo em ambas as direções. Os estimadores propostos são úteis para determinar a taxa de híbridos em amostras de sementes.

  1. One for all? : connectedness to nature, inclusion of nature, environmental identity, and implicit association with nature

    NARCIS (Netherlands)

    Brügger, A; Kaiser, F.G.; Roczen, N.

    2011-01-01

    Pleasurable experiences in nature are suspected to promote a personal connection with nature, and subsequently, nature conservation in individuals. Using an Internet-based survey employing a convenience sample of the general population (N = 1,309), we developed a connection-with-nature instrument

  2. A Natural Logic for Natural-Language Knowledge Bases

    DEFF Research Database (Denmark)

    Andreasen, Troels; Styltsvig, Henrik Bulskov; Jensen, Per Anker

    2017-01-01

    We describe a natural logic for computational reasoning with a regimented fragment of natural language. The natural logic comes with intuitive inference rules enabling deductions and with an internal graph representation facilitating conceptual path finding between pairs of terms as an approach t...

  3. A Natural Logic for Natural-language Knowledge Bases

    DEFF Research Database (Denmark)

    Andreasen, Troels; Bulskov, Henrik; Jensen, Per Anker

    2017-01-01

    We describe a natural logic for computational reasoning with a regimented fragment of natural language. The natural logic comes with intuitive inference rules enabling deductions and with an internal graph representation facilitating conceptual path finding between pairs of terms as an approach t...

  4. [Development of the Feelings toward Nature Scale and relationship between feelings toward nature and proximity to nature].

    Science.gov (United States)

    Shibata, Seiji

    2016-04-01

    In the field of environmental psychology, there is rapidly growing interest in the concept of connectivity with nature, describing an individual's sense of being connected with nature. The author developed a new scale for assessing feelings toward nature, including connectedness. Confirmatory factor analysis indicated a five-factor model consisting of restorativeness, oneness, mystery, care, and aversion. Then, the relationships among availability of nature in respondents' neighborhood, age, and each subscale score of the Feelings toward Nature Scale, were analyzed using structural equation modeling. The availability of nature in neighborhoods was assessed using a geographic information system and respondents' subjective evaluations. Results indicate that overall connectedness to nature is weaker as availability of nature decreases, as assessed by subjective evaluation. Results also suggest that aversion toward nature in younger people is relatively stronger than in older generations.

  5. Prevalencia de microsporidios y otros parásitos intestinales en pacientes con infección por VIH, Bogotá, 2001.

    Directory of Open Access Journals (Sweden)

    Astrid Carolina Flórez

    2003-09-01

    Full Text Available Los parásitos intestinales oportunistas son protozoos que causan diarrea en pacientes infectados con el virus de inmunodeficiencia humana (VIH. Para determinar la prevalencia de microsporidios y otros parásitos oportunistas intestinales en pacientes infectados con el VIH con síntomas gastrointestinales y sistémicos, se estudiaron 115 pacientes que durante el 2001 consultaron al Hospital Santa Clara (33,0%, Clínica San Pedro-ISS (20,0%, Hospital Simón Bolívar (14,8%, San José (13,9%, Central de la Policía (6,1%, Compensar (5,2%, Liga de Lucha contra el Sida (2,6%, Hospital San Ignacio (2,6% y Hospital Militar (1,7%. La edad promedio fue de 36 años con un rango de 18 a 71 años; 14 eran mujeres y 101 hombres. La metodología empleada fue la recolección por paciente de dos muestras de materia fecal seriadas para montaje directo, concentración, coloración de Zielh Neelsen modificada para diagnóstico de coccidios intestinales y coloraciones de cromotropo modificada, Gramcromotropo y calcoflúor para diagnóstico de microsporidios. La prevalencia de oportunistas fue de 10,4 % para Cryptosporidium sp. En cuanto a microsporidios, se encontró que de 29% de positividad con cromotropo modificada como tamizaje, tan sólo 3,5% de las muestras se confirmaron como positivas con técnicas de calcoflúor y Gram-cromotropo. La prevalencia general de parásitos intestinales fue de 59,1%, de los cuales los principales patógenos fueron Blastocystis hominis con 25,2% y Entamoeba histolytica con 13%. En otros estudios con pacientes inmunosuprimidos por el VIH en Colombia, se han encontrado prevalencias de Cryptosporidium sp. menores que la hallada en esta investigación.

  6. Comportamento higroscópico do extrato seco de urucum (Bixa Orellana L Hygroscopic behavior of annatto (Bixa Orellana L dried extract

    Directory of Open Access Journals (Sweden)

    George Carlos dos Santos Anselmo

    2008-12-01

    Full Text Available Neste trabalho, objetivou-se determinar a higroscopicidade do urucum na forma de extrato seco. Neste estudo foram obtidas as atividades de água do extrato seco de urucum para as temperaturas de 10 a 50ºC e teores de água entre 6 e 22% base úmida. A metodologia empregada para as determinações foi o método dinâmico em que se utilizou o equipamento Thermoconstanter Novasina TH-2. Para os resultados experimentais aplicaram-se as equações propostas por Henderson modificada por Thompson e Henderson modificada por Cavalcanti Mata e Peleg. Por meio das análises dos parâmetros encontrados concluiu-se que a equação que melhor se ajusta aos dados experimentais é a equação de Henderson modificada por Cavalcanti Mata e que as isotermas de adsorção de água do extrato de urucum seco se comportaram sigmoidalmente, sendo consideradas do tipo II.The objective of this work was to verify the higroscopicity of annatto seeds in the dry extract form. The isotherms were determined by the dynamic method with the Thermoconstanter Novasina TH-2 equipment. The equilibrium temperatures were 10, 20, 30, 40 and 50 ºC to range of moisture content between 6 and 22%, wet basis. The equations proposed by Henderson modified by Thompson and Henderson modified by Cavalcanti Mata and Peleg were applied to the experimental data. Through the gotten parameters found concluded that the best equation to represent the experimental data is the Henderson equations modified by Cavalcanti Mata. It was also concluded that hygroscopic equilibrium isotherms of annatto seeds presented sigmoid forms, considered type II.

  7. Which naturalism for bioethics? A defense of moderate (pragmatic) naturalism.

    Science.gov (United States)

    Racine, Eric

    2008-02-01

    There is a growing interest in various forms of naturalism in bioethics, but there is a clear need for further clarification. In an effort to address this situation, I present three epistemological stances: anti-naturalism, strong naturalism, and moderate pragmatic naturalism. I argue that the dominant paradigm within philosophical ethics has been a form of anti-naturalism mainly supported by a strong 'is' and 'ought' distinction. This fundamental epistemological commitment has contributed to the estrangement of academic philosophical ethics from major social problems and explains partially why, in the early 1980s, 'medicine saved the life of ethics'. Rejection of anti-naturalism, however, is often associated with strong forms of naturalism that commit the naturalistic fallacy and threaten to reduce the normative dimensions of ethics to biological imperatives. This move is rightly dismissed as a pitfall since ethics is, in part, a struggle against the course of nature. Rejection of naturalism has drawbacks, however, such as deterring bioethicists from acknowledging the implicit naturalistic epistemological commitments of bioethics. I argue that a moderate pragmatic form of naturalism represents an epistemological position that best embraces the tension of anti-naturalism and strong naturalism: bioethics is neither disconnected from empirical knowledge nor subjugated to it. The discussion is based upon historical writings in philosophy and bioethics.

  8. Aplicaciones tecnológicas de las arcillas modificadas

    OpenAIRE

    Zavala Huaytán, Candy Natalie; Zavala Huaytán, Candy Natalie; Zavala Huaytán, Candy Natalie

    2009-01-01

    Las arcillas de la familia de las esmectitas representan un grupo de minerales constituidos por filosilicatos, cuyas propiedades físico-químicas dependen de su estructura y del tamaño de grano, muy fino (menor a 2 pm). Una propiedad peculiar de estas estructuras es que presentan sustituciones isomórficas que permiten sustituir al átomo de silicio (Si), situado en el centro de los tetraedros, por otro de menor carga, como el aluminio (Al3+); igualmente, se puede reemplazar el aluminio de las c...

  9. Aplicaciones tecnológicas de las arcillas modificadas

    OpenAIRE

    Picasso, Gino; Sun Kou, María del Rosario

    2008-01-01

    Las arcillas de la familia de las esmectitas representan un grupo de minerales constituidos por filosilicatos, cuyas propiedades físico-químicas dependen de su estructura y del tamaño de grano, muy fino (menor a 2 µm). Una propiedad peculiar de estas estructuras es que presentan sustituciones isomórficas que permiten sustituir al átomo de silicio (Si), situado en el centro de los tetraedros, por otro de menor carga, como el aluminio (A1(3+)); igualmente, se puede reemplazar el aluminio de las...

  10. Temporal naturalism

    Science.gov (United States)

    Smolin, Lee

    2015-11-01

    Two people may claim both to be naturalists, but have divergent conceptions of basic elements of the natural world which lead them to mean different things when they talk about laws of nature, or states, or the role of mathematics in physics. These disagreements do not much affect the ordinary practice of science which is about small subsystems of the universe, described or explained against a background, idealized to be fixed. But these issues become crucial when we consider including the whole universe within our system, for then there is no fixed background to reference observables to. I argue here that the key issue responsible for divergent versions of naturalism and divergent approaches to cosmology is the conception of time. One version, which I call temporal naturalism, holds that time, in the sense of the succession of present moments, is real, and that laws of nature evolve in that time. This is contrasted with timeless naturalism, which holds that laws are immutable and the present moment and its passage are illusions. I argue that temporal naturalism is empirically more adequate than the alternatives, because it offers testable explanations for puzzles its rivals cannot address, and is likely a better basis for solving major puzzles that presently face cosmology and physics. This essay also addresses the problem of qualia and experience within naturalism and argues that only temporal naturalism can make a place for qualia as intrinsic qualities of matter.

  11. On the Relationship between a Computational Natural Logic and Natural Language

    DEFF Research Database (Denmark)

    Andreasen, Troels; Bulskov, Henrik; Nilsson, Jørgen Fischer

    2016-01-01

    This paper makes a case for adopting appropriate forms of natural logic as target language for computational reasoning with descriptive natural language. Natural logics are stylized fragments of natural language where reasoning can be conducted directly by natural reasoning rules reflecting intui...... intuitive reasoning in natural language. The approach taken in this paper is to extend natural logic stepwise with a view to covering successively larger parts of natural language. We envisage applications for computational querying and reasoning, in particular within the life-sciences....

  12. Natural gas trends

    International Nuclear Information System (INIS)

    Anderson, A.

    1991-01-01

    This book provides data on many facets of the natural gas industry. Topics include: Canadian, Mexican; US natural gas reserves and production; Mexican and US natural gas consumption; market conditions for natural gas in the US; and Canadian natural gas exports

  13. 128. Seudoaneurisma aórtico gigante con fístula pulmonar tras cirugía de bentall-de bono

    Directory of Open Access Journals (Sweden)

    E. Gutiérrez Carretero

    2010-01-01

    La técnica Bentall - De Bono modificada ha demostrado ser segura y de elección para todas las enfermedades de la válvula aórtica y aorta ascendente. La dehiscencia de sutura es la causa más frecuente de PsA, siendo la presencia de fístula entre PsA y AP excepcional.

  14. Natural(es) remisión de V. ciencias natural(es).

    OpenAIRE

    2011-01-01

    [ES] Definición del término Natural(es) remisión de V. ciencias natural(es). en el diccionario Dicter. [EN] Definition of the word Natural(es) remisión de V. ciencias natural(es). in the dictionary Dicter.

  15. Natural Gas

    OpenAIRE

    Bakar, Wan Azelee Wan Abu; Ali, Rusmidah

    2010-01-01

    Natural gas fuel is a green fuel and becoming very demanding because it is environmental safe and clean. Furthermore, this fuel emits lower levels of potentially harmful by-products into the atmosphere. Most of the explored crude natural gas is of sour gas and yet, very viable and cost effective technology is still need to be developed. Above all, methanation technology is considered a future potential treatment method for converting the sour natural gas to sweet natural gas.

  16. PLURALIZING NATURE

    DEFF Research Database (Denmark)

    Clemmensen, Thomas Juel

    2014-01-01

    Denmark is widely recognised for its democratic approach to planning and the idea of planning for the common good. This interest in the common good and common values seems also to be reflected in the way which nature restoration is planned and managed – one common nature directed by the public...... authorities. But nature restoration is far from being a neural undertaking. Just like any other type of heritage production it can be the source of dissonance – ‘our’ nature is not necessary ‘their’ nature. Often this dissonance is managed in ways, which are not particular sensitive to site......-specificity. As exemplified by the Skjern River Restoration Project (1999-2003), one interpretation of the landscape sometimes suppresses other valid interpretations neglecting its diverse history. However, evidence from Switzerland suggests that planning for the common good, in the case of nature restoration, does...

  17. Natural Nanoparticles: A Particular Matter Inspired by Nature

    Directory of Open Access Journals (Sweden)

    Sharoon Griffin

    2017-12-01

    Full Text Available During the last couple of decades, the rapidly advancing field of nanotechnology has produced a wide palette of nanomaterials, most of which are considered as “synthetic” and, among the wider public, are often met with a certain suspicion. Despite the technological sophistication behind many of these materials, “nano” does not always equate with “artificial”. Indeed, nature itself is an excellent nanotechnologist. It provides us with a range of fine particles, from inorganic ash, soot, sulfur and mineral particles found in the air or in wells, to sulfur and selenium nanoparticles produced by many bacteria and yeasts. These nanomaterials are entirely natural, and, not surprisingly, there is a growing interest in the development of natural nanoproducts, for instance in the emerging fields of phyto- and phyco-nanotechnology. This review will highlight some of the most recent—and sometimes unexpected—advances in this exciting and diverse field of research and development. Naturally occurring nanomaterials, artificially produced nanomaterials of natural products as well as naturally occurring or produced nanomaterials of natural products all show their own, particular chemical and physical properties, biological activities and promise for applications, especially in the fields of medicine, nutrition, cosmetics and agriculture. In the future, such natural nanoparticles will not only stimulate research and add a greener outlook to a traditionally high-tech field, they will also provide solutions—pardon—suspensions for a range of problems. Here, we may anticipate specific biogenic factories, valuable new materials based on waste, the effective removal of contaminants as part of nano-bioremediation, and the conversion of poorly soluble substances and materials to biologically available forms for practical uses.

  18. Natural Philosophy

    OpenAIRE

    Blair, Ann M.

    2006-01-01

    Natural philosophy” is often used by European historians as an umbrella term to designate the study of nature before it can easily be identified with what we call “science” today, to avoid the modern and potentially anachronistic connotations of that term. But “natural philosophy” (and its equivalents in different languages) was also an actor's category, a term commonly used throughout the early modern period and typically defined quite broadly as the study of natural bodies. As the central ...

  19. Nature's palette: the search for natural blue colorants.

    Science.gov (United States)

    Newsome, Andrew G; Culver, Catherine A; van Breemen, Richard B

    2014-07-16

    The food and beverage industry is seeking to broaden the palette of naturally derived colorants. Although considerable effort has been devoted to the search for new blue colorants in fruits and vegetables, less attention has been directed toward blue compounds from other sources such as bacteria and fungi. The current work reviews known organic blue compounds from natural plant, animal, fungal, and microbial sources. The scarcity of blue-colored metabolites in the natural world relative to metabolites of other colors is discussed, and structural trends common among natural blue compounds are identified. These compounds are grouped into seven structural classes and evaluated for their potential as new color additives.

  20. Study of the Cd (II) removal in the presence of methyl orange with a natural zeolite conditioned with iron nanoparticles; Estudio de la remocion de Cd(II) en presencia de naranja de metilo con una zeolita natural acondicionada con nanoparticulas de hierro

    Energy Technology Data Exchange (ETDEWEB)

    Xingu C, E. G.

    2015-07-01

    This work presents a study on the removal of cadmium and/or methyl-orange dye in aqueous solution, using natural zeolite clinoptilolite, as sodium homo-ionized and impregnated with iron nanoparticles. Iron nanoparticles were synthesized in the presence of the zeolite by chemical reduction. The evaluation of the removal ability was performed in a monocomponent (cadmium or methyl-orange dye) system by varying the contact time and its initial concentration. Removal capacity in a bi-component (cadmium and methyl orange) system was also studied while varying their concentrations. The characterization of the zeolites, before and after the sorption process, was carried out using several analytical techniques. The characteristics of zeolite clinoptilolite and iron particles were observed by scanning electron microscopy. The iron particles showed diameter sizes between 60 and 200 nm, localized on the surface of the zeolite. By IR spectroscopy no structural changes were detected for any of the treatments made to the zeolitic materials. By X-ray diffraction the clinoptilolite crystalline phase was mainly identified, however, it failed to detect any phase of iron in the zeolite impregnated with iron nanoparticles. Moessbauer spectroscopy indeed detected the impregnated iron phase as iron borides. The homo-ionized and iron nanoparticles impregnated zeolite showed no change in the specific surface area, or the isoelectric point, their values were 22.3 m{sup 2}/g and ph 9.8, respectively. However, whereas the active site density for the homo-ionized zeolite was 2.87 sites/nm{sup 2}, for iron nanoparticles impregnated zeolite was 20.32 sites/nm{sup 2}. As a result of the analysis of the isotherms of cadmium, the maximum sorption capacity of the homo-ionized zeolite was 35.03 mg/g and for the iron nanoparticles impregnated zeolite was 36.43 mg/g. These maximum sorption capacities represent up to 85% of removed cadmium from concentrations of 50 to 600 mg/L. For the removal of methyl

  1. Learning from nature: Nature-inspired algorithms

    DEFF Research Database (Denmark)

    Albeanu, Grigore; Madsen, Henrik; Popentiu-Vladicescu, Florin

    2016-01-01

    .), genetic and evolutionary strategies, artificial immune systems etc. Well-known examples of applications include: aircraft wing design, wind turbine design, bionic car, bullet train, optimal decisions related to traffic, appropriate strategies to survive under a well-adapted immune system etc. Based......During last decade, the nature has inspired researchers to develop new algorithms. The largest collection of nature-inspired algorithms is biology-inspired: swarm intelligence (particle swarm optimization, ant colony optimization, cuckoo search, bees' algorithm, bat algorithm, firefly algorithm etc...... on collective social behaviour of organisms, researchers have developed optimization strategies taking into account not only the individuals, but also groups and environment. However, learning from nature, new classes of approaches can be identified, tested and compared against already available algorithms...

  2. Dissonant Nature

    DEFF Research Database (Denmark)

    Clemmensen, Thomas Juel

    2013-01-01

    Nature restoration is far from being a neural undertaking. Just like any other type of heritage production it can be the source of dissonance – ‘our’ nature is not necessary ‘their’ nature. Often this dissonance is managed in ways, which are not particular sensitive to site-specificity. As exempl...... and allows for multiple interpretations to coexist. Evidence can be found in the Re-naturalization of River Aire (2002-2015), a restoration project, which reveals approaches that could be labelled landscape architecture specific....

  3. Natural gas and Brazilian energetic matrix; Gas natural no Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Moraes, Ricardo Luchese de [White Martins S.A., Rio de Janeiro, RJ (Brazil)

    1997-07-01

    Recent projection of the market in global scale shows a tendency in natural gas using replacing mostly the fuel oil. Its market share well increase from 21.1% in 1994 to 24.0% in 2010. The annual energetic use will reach 29.23 x 10{sup 9} Gcal in 2010 (8990 million Nm{sup 3} natural gas/day) versus 18.90 x 10{sup 9} Gcal in 1994 (5810 million Nm{sup 3} natural gas/day). For Brazil, its consumption will increase from 8.7 million Nm{sup 3} natural gas/day in 1994 to 35.9 million Nm{sup 3} natural gas/day in 2010. Projects like Brazil-Bolivia natural gas pipeline, will supply 18 million Nm{sup 3} natural gas/day, which expected to start-up before the year 2000. This projects will supply the Brazilian southern regions, that do not consume natural gas at the current moment. Although there are many different kind of natural gas consumption in the industry this paper presents the technical and economical estimate of the injection in the blast furnace operating with coke or charcoal. The process simulation is done assisted by math modeling developed by White Martins/Praxair Inc. (author)

  4. US crude oil, natural gas, and natural gas liquids reserves

    International Nuclear Information System (INIS)

    1992-01-01

    This report presents estimates of proved reserves of crude oil, natural gas, and natural gas liquids as of December 31, 1991, as well as production volumes for the United States, and selected States and State subdivisions for the year 1991. Estimates are presented for the following four categories of natural gas: total gas (wet after lease separation), its two major components (nonassociated and associated-dissolved gas), and total dry gas (wet gas adjusted for the removal of liquids at natural gas processing plants). In addition, two components of natural gas liquids, lease condensate and natural gas plant liquids, have their reserves and production data presented. Also included is information on indicated additional crude oil reserves and crude oil, natural gas, and lease condensate reserves in nonproducing reservoirs. A discussion of notable oil and gas exploration and development activities during 1991 is also presented

  5. Naturalism and un-naturalism among the Cartesian physicians

    OpenAIRE

    Manning, Gideon

    2008-01-01

    Highlighting early modern medicine's program of explanation and intervention, I claim that there are two distinctive features of the physician's naturalism. These are, first, an explicit recognition that each patient had her own individual and highly particularized nature and, second, a self-conscious use of normative descriptions when characterizing a patient's nature as healthy (ordered) or unhealthy (disordered). I go on to maintain that in spite of the well documented Cartesian rejection ...

  6. Determinação de mercúrio em águas por CVAAS empregando sílica modificada por 2-aminotiazol

    OpenAIRE

    Silva, F. A. [UNESP; Alcântara, I. L. de [UNESP; Roldan, P. S. [UNESP; Padilha, C. C. F. [UNESP; Araújo, A. B. de [UNESP; Valente, J. P. S. [UNESP; Florentino, A. O. [UNESP; Padilha, P. M. [UNESP

    2005-01-01

    This paper discusses a rapid and sensitive method developed to determine trace levels of mercury in natural water samples by cold vapor atomic absorption spectrometry using a preconcentration system composed by mini-column packed with 100 mg of 2-aminothiazol modified silica gel (SiAT) coupled on-line with the spectrometer's cold vapor generator system. The optimum preconcentration conditions are also described here. The preconcentrated Hg(II) ions were eluted directly from the column to the ...

  7. Natural gas monthly

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-01-01

    The Natural Gas Monthly highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. From time to time, the Natural Gas Monthly features articles designed to assist readers in using and interpreting natural gas information.

  8. Natural aphrodisiacs.

    Science.gov (United States)

    Shamloul, Rany

    2010-01-01

    The search for a remedy or a prescription that can enhance sexual function and/or treat male erectile dysfunction has been an obsession throughout known history. Whether it was an Eastern civilization or a Western one, religious or atheist, man's aspiration for a better or best "manhood" has been a history-time goal. This review will discuss the current research done on the most popular natural aphrodisiacs and examine the weight of evidence to support or discourage the use of any of these substances to enhance sexual desire and/or function. Review of the current evidence on the use of natural substances as aphrodisiacs. Efficacy of natural aphrodisiacs in enhancing sexual function in men and women. There is little evidence from literature to recommend the usage of natural aphrodisiacs for the enhancement of sexual desire and/or performance. Data on yohimbine's efficacy does not support the wide use of the drug, which has only mild effects in the treatment of psychogenic ED. Although there's a positive trend towards recommending ginseng as an effective aphrodisiac, however, more in depth studies involving large number of subjects and its mechanism of action are needed before definite conclusions could be reached. Data on the use of natural aphrodisiacs in women is limited. The current body of objective evidence does not support the use of any natural aphrodisiac as an effective treatment for male or female sexual dysfunctions. Potent men and men with ED will continue the search for natural aphrodisiacs despite the current disappointing data on their effectiveness. Care should be taken regarding the fraud addition of sildenafil analogues to natural aphrodisiacs.

  9. ANÁLISIS CARIOTÍPICO DE CAPSICUM PUBESCENS (SOLANACEAE "ROCOTO"

    Directory of Open Access Journals (Sweden)

    Misael Guevara

    2014-06-01

    Full Text Available Análisis cariotípico de Capsicum pubescens R&P (Solanaceae. Los cromosomas han sido descritos, comparados y dibujados, usando una técnica de coloración modificada, C. pubescens tiene un número cromosómico diploide 2n = 24, de los cuales 11 pares son metacéntricos y 1 par submetacéntrico.

  10. Análisis de un sistema de selección de plantas transgénicas basado en la técnica de PCR

    Directory of Open Access Journals (Sweden)

    Yomara Ivonne Rozo Peña

    2004-07-01

    propuesta viable en cuanto a implementación práctica, versatilidad y confiabilidad de la planta transgénica. El sistema de selección por PCR contribuye a la inserción competitiva de los cultivos transgénicos dentro del marco socio-económico con respecto a las variedades modificadas genéticamente producidas en la actualidad.

  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

    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

  12. Deslignificación de pasta kraft de Pinus radiata con una levadura genéticamente modificada para producir lacasa

    OpenAIRE

    Arana-Cuenca, A.; Yagüe, Susana; Fermiñán, Encarnación

    2010-01-01

    Una posible aplicación biotecnológica de las lacasas fúngicas es el blanqueo de pasta de papel mediante la degradación de la lignina en la pasta cruda. Para ello es necesaria su producción a bajo coste y a concentraciones superiores a las secretadas por los hongos de forma natural. La expresión heteróloga en levaduras es una alternativa para su producción a mayor escala. En el presente trabajo se ha realizado la expresión heteróloga del gen cglcc1, responsable de la producción de lacasa en el...

  13. Removal of the blue 1 dye of aqueous solutions using ferric zeolite; Remocion del colorante azul 1 de soluciones acuosas utilizando zeolita ferrica

    Energy Technology Data Exchange (ETDEWEB)

    Pinedo H, S. Y.

    2010-07-01

    Water is essential to all life forms, including humans. In recent years water use has increased substantially, also has been altered in its capacity as a result of various human activities, such as domestic, industrial and agricultural, also by natural activity. Undoubtedly one of the main pollutants today are the waste generated by the food industry, due to the use of dyes for the production of their products. So it is necessary to restore water quality through treatment systems to remove contaminants, and thus prevent disease and imbalance of ecosystems. Due to the above, it is important to conduct research directed towards finding new ways to remove dyes such as blue 1 used in the food industry, using low cost materials and abundant in nature as zeolites. To accomplish the above, the present study has the purpose to evaluate the adsorption capacity of the blue dye 1 in aqueous solutions. To accomplish that objective, the zeolite material was reconditioned to improve its sorption properties of the material and provide the ability to adsorb pollutants such as this dye. The zeolite material was characterized by scanning electron microscopy and elemental analysis, X-ray diffraction and infrared spectroscopy. To evaluate the ability of blue 1 dye sorption the kinetics and sorption isotherms were determined; the experimental results were adjusted to mathematical models such as pseudo-first order, pseudo second order and Elovich to describe the kinetic process, and the Langmuir, Freundlich and Langmuir-Freundlich to describe sorption isotherms. The results showed that ferric zeolite surface is a heterogeneous material and has a considerable adsorption capacity, which makes it a potential adsorbent for removing color from aqueous streams. Also the sorption of the dye was evaluated at different ph values; the most sorption was carried out at ph values 1, 3 and 11. We also evaluated the change in mass where the sorption capacities for the blue 1 increase by increasing

  14. Oklo natural reactor

    International Nuclear Information System (INIS)

    Fujii, Isao

    1985-01-01

    In 1954, Professor Kazuo, Kuroda of Arkansas University in USA published the possibility that spontaneously generated natural nuclear reactors existed in prehistoric age. In 1972, 18 years after that, Commissariat a l'Energie Atomique published that in the Oklo uranium deposit in Gabon, Africa, a natural nuclear reactor was found. This fact was immediately informed to the whole world, but in Japan, its details have not necessarily been well known. The chance of investigating into this fact and visiting the Oklo deposit by the favor of COMUF, the owner of the Oklo deposit, was given, therefore, the state of the natural reactors, which has been known so far, is reported. At present, 12 natural reactors have been found in the vicinity of the Oklo deposit. The natural reactors were generated spontaneously in uranium deposits about 1.7 billion years ago when the isotopic abundance of U-235 was 3 %, and the chain reaction started naturally. When the concentration of U-235 lowered, the reaction stopped naturally. The abnormality in the U-235 abundance in natural uranium was found, and the cause was pursued. The evidence of the existence of natural reactors was shown. (Kako, I.)

  15. Natural and near natural tropical forest values

    Science.gov (United States)

    Daniel H. Henning

    2011-01-01

    This paper identifies and describes some of the values associated with tropical rain forests in their natural and near-natural conditions. Tropical rain forests are moist forests in the humid tropics where temperature and rainfall are high and the dry season is short. These closed (non-logged) and broad-leaved forests are a global resource. Located almost entirely in...

  16. Composición y diversidad de la regeneración natural en comunidades de Pinus-Quercus sometidas a una alta recurrencia de incendios en el noreste de México Composition and diversity of natural regeneration in Pinus-Quercus communities under high fire recurrence in northeastern México

    Directory of Open Access Journals (Sweden)

    Eduardo Alanís-Rodríguez

    2012-12-01

    Full Text Available Se estudió la regeneración natural a medio plazo de especies leñosas en un bosque mixto de Pinus-Quercus sometido a alta recurrencia de incendios (1972, 1984 y 1998 de mediana-alta intensidad en el noreste de México. El objetivo fue determinar la capacidad de recuperación de la vegetación frente a incendios recurrentes, y si ésta se puede ver modificada por una variable fisiográfica como es la exposición de la ladera (NE vs. NO. Los resultados mostraron que el 93% de las especies arbóreas son rebrotadoras obligadas que ya estaban antes del fuego. Esta capacidad de rebrote permite la reconstitución de la parte aérea de individuos ya existentes. El género clave por su abundancia es Quercus, siendo Q. rysophylla la especie más abundante después del fuego. Si bien la especie Pinus pseudostrobus está adaptada al fuego mediante una corteza gruesa y la longevidad de su banco de semillas, los incendios de mediana-alta intensidad de manera frecuente implican la pérdida local de la especie. Las exposiciones evaluadas no presentan diferencias significativas en su densidad (N/ha y dominancia (m²/ha pero sí en su diversidad y composición, siendo la exposición NO la más diversa. Estos resultados proporcionan una herramienta a considerar en la elaboración de planes de gestión de áreas protegidas del NE de México.We evaluated the natural regeneration of woody species at the mid-term in a Pinus-Quercus mixed forest affected by frequent medium-to-high intensity wildfires (1972, 1984 and 1998 in northeastern Mexico. The objective was to determine the recovery of vegetation from recurrent fires, and whether it depends on slope exposure (NE vs. NW. The results indicated that 93% of the species are obligated resprouters already present in the site before the fires. This capability enables the reconstitution of aerial part of existing individuals. According to abundance records, the key genus was Quercus, and Q. rysophylla was the most

  17. A Natural Love of Natural Products

    OpenAIRE

    Kingston, David G. I.

    2008-01-01

    Recent research on the chemistry of natural products from the author?s group that led to the receipt of the ACS Ernest Guenther Award in the Chemistry of Natural Products is reviewed. REDOR NMR and synthetic studies established the T-taxol conformation as the bioactive tubulin-binding conformation, and these results were confirmed by the synthesis of compounds which clearly owed their activity or lack of activity to whether or not they could adopt the T-taxol conformation. Similar studies wit...

  18. 18 CFR 2.78 - Utilization and conservation of natural resources-natural gas.

    Science.gov (United States)

    2010-04-01

    ... conservation of natural resources-natural gas. 2.78 Section 2.78 Conservation of Power and Water Resources... INTERPRETATIONS Statements of General Policy and Interpretations Under the Natural Gas Act § 2.78 Utilization and conservation of natural resources—natural gas. (a)(1) The national interests in the development and utilization...

  19. Manejo de soja transgênica com glifosato e imazetapir: efeito sobre a mesofauna e microbiota do solo

    Directory of Open Access Journals (Sweden)

    Danilo Dufech Castilhos

    2010-10-01

    Full Text Available A estabilidade de diferentes organismos da mesofauna, como ácaros e colêmbolos, e a atividade microbiana do solo são indicadores de qualidade físico-química e biológica do solo. Este trabalho teve por objetivo avaliar o efeito de métodos de controle de plantas concorrentes sobre a qualidade do solo cultivado com soja transgênica. Neste contexto, foram cultivados dois genótipos de soja, geneticamente modificada (GMRR BRS 244 RR e não modificada (NM BRS 154, no Centro Agropecuário da Palma da Universidade Federal de Pelotas (CAP, nas safras de 2005/2006 e 2006/2007. Para o controle de plantas daninhas, testaram-se, tratamentos com glifosato, imazetapir e capina. Avaliaram-se populações de ácaros e colêmbolos, o carbono da biomassa microbiana, a respiração basal e o quociente metabólico do solo. Verificou-se que a aplicação dos herbicidas, principalmente de glifosato, em soja BRS 244 RR cultivada em Planossolo resultou em desestabilidade da mesofauna e maior atividade da biomassa microbiana.

  20. Comportamiento de la corrosión de aleaciones de magnesio AZ31-B en ambiente marino, modificadas por el proceso de fricción-agitación Corrosion behavior in marine environment of magnesium alloy AZ31-B welded by friction-agitation process

    Directory of Open Access Journals (Sweden)

    Willian Aperador Chaparro

    2012-04-01

    Full Text Available En el presente artículo se estudia el comportamiento de la corrosión de la aleación de magnesio AZ31-B en ambiente marino simulado, modificada mediante el proceso de fricción-agitación (PFA, con el fin de determinar el efecto de las variables del proceso, velocidad de rotación y velocidad de avance. Se llevaron a cabo análisis mediante espectroscopia de impedancia electroquímica y curvas de polarización potencio-dinámicas (Tafel. Adicionalmente, se determinó la microestructura en las zonas del cordón de soldadura a través de metalografía óptica. Finalmente, se analizaron los productos de corrosión formados en la superficie de las muestras por medio del microscopio electrónico de barrido (SEM equipado con el analizador químico por EDS. Se observó que una relación de velocidad de avance/velocidad de rotación mayor produce menor velocidad de corrosión y con ello mayor resistencia a la corrosión en medios salinos, al parecer relacionados con el gran tamaño de grano en la zona agitada, que corresponde a más entrada de calor.The corrosion behavior of AZ31B magnesium alloy modified by friction stir processing (FSP was studied in simulated marine environment, in order to determine the effect of process variables rotation speed and travel speed. The corrosion analysis was carried upon by means of electrochemical impedance spectroscopy and potentiodynamic polarization curves (Tafel, metallographic analysis of the welded zones was done by optical microscopy and the chemical analysis of the corrosion products were done by using scanning electron microscope (SEM, equipped with EDS analyzer. It was observed that the increase of the rate rotation speed/travel speed of the process produces a decrease in the corrosion rate and the corresponding increase of the corrosion resistance in marine environment, apparently related to the higher grain size found in the stir zone, corresponding to a higher heat input.

  1. Nature gives us strength: exposure to nature counteracts ego-depletion.

    Science.gov (United States)

    Chow, Jason T; Lau, Shun

    2015-01-01

    Previous research rarely investigated the role of physical environment in counteracting ego-depletion. In the present research, we hypothesized that exposure to natural environment counteracts ego-depletion. Three experiments were conducted to test this hypothesis. In Experiment 1, initially depleted participants who viewed pictures of nature scenes showed greater persistence on a subsequent anagram task than those who were given a rest period. Experiment 2 expanded upon this finding by showing that natural environment enhanced logical reasoning performance after ego-depleting task. Experiment 3 adopted a two- (depletion vs. no-depletion) -by-two (nature exposure vs. urban exposure) factorial design. We found that nature exposure moderated the effect of depletion on anagram task performance. Taken together, the present studies offer a viable and novel strategy to mitigate the negative impacts of ego-depletion.

  2. Connection to Nature: Children's Affective Attitude toward Nature

    Science.gov (United States)

    Cheng, Judith Chen-Hsuan; Monroe, Martha C.

    2012-01-01

    A connection to nature index was developed and tested to measure children's affective attitude toward the natural environment. The index was employed through a survey that investigates students' attitude toward Lagoon Quest, a mandatory environmental education program for all fourth-grade, public school students in Brevard County, Florida. Factor…

  3. Three Sorts of Naturalism

    OpenAIRE

    Fink, Hans

    2006-01-01

    In "Two sorts of Naturalism" John McDowell is sketching his own sort of naturalism in ethics as an alternative to "bald naturalism". In this paper I distinguish materialist, idealist and absolute conceptions of nature and of naturalism in order to provide a framework for a clearer understanding of what McDowell's own naturalism amounts to. I argue that nothing short of an absolute naturalism will do for a number of McDowell's own purposes, but that it is far from obvious that this is his posi...

  4. Nature in Preschool

    DEFF Research Database (Denmark)

    Husted, Mia; Frøkjær, Thorleif

    Nature and nature phenomena’ has formed a specific curriculum theme in Danish preschool since early childhood curriculum was prescribed by law in 2004. However, recent evaluations show that the implementation of an early childhood curriculum has not produced an increased pedagogical focus...... on ‘nature and nature phenomena’ in preschools (EVA 2012). This finding, along with an increased political interest in goals and measurable outcome of early childhood curriculum (Broström 2012), will be the starting point in our ambition to carry out a more thorough qualitative investigation into links...... between preschool teachers’ understanding and interest in teaching nature and the rather poor evaluation....

  5. Naturalisms and religion

    NARCIS (Netherlands)

    Drees, Willem

    1997-01-01

    Such terms as materialism, naturalism, and near synonyms evoke strong negative reactions among many believers. However, the notion of naturalism has various meanings; implications for religion differ for the several varieties of naturalism. In this paper I analyze epistemological and ontological

  6. New methods for assessing the fascinating nature of nature experiences.

    Science.gov (United States)

    Joye, Yannick; Pals, Roos; Steg, Linda; Evans, Ben Lewis

    2013-01-01

    In recent years, numerous environmental psychology studies have demonstrated that contact with nature as opposed to urban settings can improve an individual's mood, can lead to increased levels of vitality, and can offer an opportunity to recover from stress. According to Attention Restoration Theory (ART) the restorative potential of natural environments is situated in the fact that nature can replenish depleted attentional resources. This replenishment takes place, in part, because nature is deemed to be a source of fascination, with fascination being described as having an "attentional", an "affective" and an "effort" dimension. However, the claim that fascination with nature involves these three dimensions is to a large extent based on intuition or derived from introspection-based measurement methods, such as self-reports. In three studies, we aimed to more objectively assess whether these three dimensions indeed applied to experiences related to natural environments, before any (attentional) depletion has taken place. The instruments that were used were: (a) the affect misattribution procedure (Study 1), (b) the dot probe paradigm (Study 2) and (c) a cognitively effortful task (Study 3). These instrument were respectively aimed at verifying the affective, attentional and effort dimension of fascination. Overall, the results provide objective evidence for the claims made within the ART framework, that natural as opposed to urban settings are affectively positive (cfr., affective dimension) and that people have an attentional bias to natural (rather than urban) environments (cfr., attentional dimension). The results regarding the effort dimension are less straightforward, and suggest that this dimension only becomes important in sufficiently difficult cognitive tasks.

  7. A Natural Language Architecture

    OpenAIRE

    Sodiya, Adesina Simon

    2007-01-01

    Natural languages are the latest generation of programming languages, which require processing real human natural expressions. Over the years, several groups or researchers have trying to develop widely accepted natural language languages based on artificial intelligence (AI). But no true natural language has been developed. The goal of this work is to design a natural language preprocessing architecture that identifies and accepts programming instructions or sentences in their natural forms ...

  8. Natural history and temporalization: reflections on Buffon's Natural history

    OpenAIRE

    Galfione, María Verónica

    2015-01-01

    This article presents a rereading of Buffon´s Natural History in the light of the concepts of temporal reversibility and irreversibility. The goal is to determine to what extent Buffon introduces a transformationist concept of natural forms in this work. To that effect, the main points of classical natural history and the doctrine of preformed germs are analyzed. Subsequently, Buffon´s use of the temporal variable is considered. This examination shows that despite his rejection of the theory ...

  9. Natural gums and modified natural gums as sustained-release carriers.

    Science.gov (United States)

    Bhardwaj, T R; Kanwar, M; Lal, R; Gupta, A

    2000-10-01

    Although natural gums and their derivatives are used widely in pharmaceutical dosage forms, their use as biodegradable polymeric materials to deliver bioactive agents has been hampered by the synthetic materials. These natural polysaccharides do hold advantages over the synthetic polymers, generally because they are nontoxic, less expensive, and freely available. Natural gums can also be modified to have tailor-made materials for drug delivery systems and thus can compete with the synthetic biodegradable excipients available in the market. In this review, recent developments in the area of natural gums and their derivatives as carriers in the sustained release of drugs are explored.

  10. Three Sorts of Naturalism

    DEFF Research Database (Denmark)

    Fink, Hans

    2006-01-01

    In "Two sorts of Naturalism" John McDowell is sketching his own sort of naturalism in ethics as an alternative to "bald naturalism". In this paper I distinguish materialist, idealist and absolute conceptions of nature and of naturalism in order to provide a framework for a clearer understanding...

  11. NATURAL GAS TRANSPORTATION

    OpenAIRE

    Stanis³aw Brzeziñski

    2007-01-01

    In the paper, Author presents chosen aspects of natural gas transportation within global market. Natural gas transportation is a technicaly complicated and economicly expensive process; in infrastructure construction and activities costs. The paper also considers last and proposed initiatives in natural gas transportation.

  12. Natural gas outlook

    International Nuclear Information System (INIS)

    Molyneaux, M.P.

    1998-01-01

    An overview of natural gas markets in Canada and in the United States was provided. The major factors that determine the direction of natural gas prices were depicted graphically. Price volatility has decreased in recent months. As expected, April through November total energy consumption reached historically high levels. Demand for natural gas during the summer of 1997 was not as strong as anticipated. Nuclear energy appears to be on the slippery slope, with natural gas-driven electricity projects to fill the void. Hydroelectricity had a strong showing in 1997. Prospects are less bright for 1998 due to above average temperatures. Canadian natural gas export capacity has increased 5.5 times between 1986 and estimated 1999 levels. Despite this, in 1997, deliveries to the United States were marginally behind expectations. Natural gas consumption, comparative fuel prices, natural gas drilling activity, natural gas storage capacity, actual storage by region, and average weekly spot natural gas prices, for both the U. S. and Canada, were also provided. With regard to Canada, it was suggested that Canadian producers are well positioned for a significant increase in their price realization mostly because of the increase in Canada's export capacity in 1997 (+175 Mmcf/d), 1998 (1,060 Mmcf/d) and potentially in 1999 or 2000, via the Alliance Pipeline project. Nevertheless, with current production projections it appears next to impossible to fill the 10.9 Bcf/d of export capacity that will be potentially in place by the end of 1999. tabs., figs

  13. Unnaturalised racial naturalism.

    Science.gov (United States)

    Hochman, Adam

    2014-06-01

    Quayshawn Spencer (2014) misunderstands my treatment of racial naturalism. I argued that racial naturalism must entail a strong claim, such as "races are subspecies", if it is to be a substantive position that contrasts with anti-realism about biological race. My recognition that not all race naturalists make such a strong claim is evident throughout the article Spencer reviews (Hochman, 2013a). Spencer seems to agree with me that there are no human subspecies, and he endorses a weaker form of racial naturalism. However, he supports his preferred version of 'racial naturalism' with arguments that are not well described as 'naturalistic'. I argue that Spencer offers us an unnaturalised racial naturalism. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. NATURAL LAW, HISTORY AND POLITICS LEY NATURAL, HISTORIA Y POLÍTICA LEI NATURAL, HISTÓRIA E POLÍTICA

    Directory of Open Access Journals (Sweden)

    James Drane

    2002-01-01

    Full Text Available The basic philosophical vision and ethical principles of Catholic Natural Law claim universality. Natural Law thinking aspires to objectivity and universality and at the same time is open to the continuing influence from history and politics. The background principles of positive law historically go by the name of Natural Law. Suffering and injustice contribute to a vision both of the structure of human existence and of what we mean by humane law and ethics. When we confront a cultural crisis, Natural Law, looks not to the past but to the future. Few people today talk of the ethical dimensions of social realities in terms of Natural Law. This is true both in the Church and in the State. In bioethics, the principles rooted in the universal structure of human life have to provide direction and regulations on the playing field of contemporary life and medicine. A liberal Catholic perspective tries to keep in play the universal and the particular aspects of Natural Law reasoningLa visión filosófica básica y los principios éticos de la Ley Natural Católica demandan universalidad. El pensamiento de la Ley Natural aspira a la objetividad y universalidad y, al mismo tiempo, está abierto a la continua influencia de la historia y la política. Los principios que yacen en la base de la ley positiva históricamente reciben el nombre de Ley Natural. El sufrimiento y la injusticia contribuyen a una visión, tanto de la estructura de la existencia humana como de lo que entendemos por una ley y una ética humanas. Cuando enfrentamos una crisis cultural, la Ley Natural no mira hacia el pasado sino que hacia el futuro. Es poca la gente que hoy en día habla de las dimensiones éticas de las realidades sociales en términos de Ley Natural. Esto vale tanto para la Iglesia como para el Estado. En bioética, los principios enraizados en la estructura universal de la vida humana tienen que proporcionar dirección y regulación en el campo de juego de la vida y

  15. ECONOMIC NATURE AND THE ROLE OF NATURAL RESOURCES PAYMENTS UNDER SUSTAINABLE ECONOMIC DEVELOPMENT

    Directory of Open Access Journals (Sweden)

    A. Zalievska-Shyshak

    2014-12-01

    Full Text Available The nature and value of natural resources payments under sustainable economic development are revealed. Mechanisms of using of natural resources potential of Ukraine are examined. Payments for use of natural resources is one of the most important components of an economic mechanism of nature management are established. Features of current legislation as to the setting fees for nature management are studied and the necessity of creating an effective institutional support in controlling of tax authorities for the collection of payments for natural resources and their evaluation is proved.

  16. New Methods for Assessing the Fascinating Nature of Nature Experiences

    Science.gov (United States)

    Joye, Yannick; Pals, Roos; Steg, Linda; Evans, Ben Lewis

    2013-01-01

    In recent years, numerous environmental psychology studies have demonstrated that contact with nature as opposed to urban settings can improve an individual’s mood, can lead to increased levels of vitality, and can offer an opportunity to recover from stress. According to Attention Restoration Theory (ART) the restorative potential of natural environments is situated in the fact that nature can replenish depleted attentional resources. This replenishment takes place, in part, because nature is deemed to be a source of fascination, with fascination being described as having an “attentional”, an “affective” and an “effort” dimension. However, the claim that fascination with nature involves these three dimensions is to a large extent based on intuition or derived from introspection-based measurement methods, such as self-reports. In three studies, we aimed to more objectively assess whether these three dimensions indeed applied to experiences related to natural environments, before any (attentional) depletion has taken place. The instruments that were used were: (a) the affect misattribution procedure (Study 1), (b) the dot probe paradigm (Study 2) and (c) a cognitively effortful task (Study 3). These instrument were respectively aimed at verifying the affective, attentional and effort dimension of fascination. Overall, the results provide objective evidence for the claims made within the ART framework, that natural as opposed to urban settings are affectively positive (cfr., affective dimension) and that people have an attentional bias to natural (rather than urban) environments (cfr., attentional dimension). The results regarding the effort dimension are less straightforward, and suggest that this dimension only becomes important in sufficiently difficult cognitive tasks. PMID:23922645

  17. Pluralising Nature

    DEFF Research Database (Denmark)

    Clemmensen, Thomas Juel

    2017-01-01

    suppress other valid perceptions, in conflict with the need for different groups of people to be able to identify with the same territory. However, planning for the common good, in the case of nature restoration, does not necessarily mean planning for one common nature. Understanding and working......Denmark is recognised for its democratic approach to planning, and for the idea of planning for the common good. This interest in the common good and in common values also seems to be reflected in the way that the restoration of nature is planned and managed, suggesting that there is one common...... “nature” that everyone can agree on. But nature restoration is far from being an unproblematic undertaking. As with any other type of heritage production, it can be the source of dissonance. As exemplified by the Skjern River Restoration Project, one perception of a landscape and its value as “nature” can...

  18. SuperNatural: a searchable database of available natural compounds.

    Science.gov (United States)

    Dunkel, Mathias; Fullbeck, Melanie; Neumann, Stefanie; Preissner, Robert

    2006-01-01

    Although tremendous effort has been put into synthetic libraries, most drugs on the market are still natural compounds or derivatives thereof. There are encyclopaedias of natural compounds, but the availability of these compounds is often unclear and catalogues from numerous suppliers have to be checked. To overcome these problems we have compiled a database of approximately 50,000 natural compounds from different suppliers. To enable efficient identification of the desired compounds, we have implemented substructure searches with typical templates. Starting points for in silico screenings are about 2500 well-known and classified natural compounds from a compendium that we have added. Possible medical applications can be ascertained via automatic searches for similar drugs in a free conformational drug database containing WHO indications. Furthermore, we have computed about three million conformers, which are deployed to account for the flexibilities of the compounds when the 3D superposition algorithm that we have developed is used. The SuperNatural Database is publicly available at http://bioinformatics.charite.de/supernatural. Viewing requires the free Chime-plugin from MDL (Chime) or Java2 Runtime Environment (MView), which is also necessary for using Marvin application for chemical drawing.

  19. WISC-III e WAIS-III na avaliação da inteligência de cegos WISC-III/WAIS-III en ciegos WISC-III and WAIS-III in intellectual assessment of blind people

    Directory of Open Access Journals (Sweden)

    Elizabeth do Nascimento

    2007-12-01

    Full Text Available Diante da escassez de pesquisas nacionais e de testes psicológicos destinados a avaliar pessoas cegas, desenvolveu-se um estudo psicométrico com as escalas verbais dos testes WISC-III e WAIS-III. Após as adaptações de alguns estímulos e das instruções, os testes foram aplicados em crianças (N = 120 e adultos (N = 52 residentes em Belo Horizonte. Os resultados indicaram que as escalas verbais modificadas apresentam uma boa consistência interna (alfa> 0,80. Além disso, a investigação da validade fatorial identifica a presença clara de apenas um componente. Este componente explica 81% e 64% para o WISC-III e WAIS-III, respectivamente. Conclui-se que as adaptações a que se procedeu não afetaram a estrutura fatorial das escalas. Deste modo, os profissionais poderão utilizar as escalas modificadas para avaliar a inteligência de pessoas cegas.Frente a la escasez de investigaciones nacionales asi como la ausencia de tests psicológicos que evaluen personas ciegas, se ha desarrollado un estudio psicometrico com la escalas verbales del WISC-III y WAIS-III. Posteriormente a las adaptaciones de algunos estímulos y de las instrucciones, las escalas fueron aplicadas a una muestra de niños (n=120 y de adultos (n=52 residentes en la ciudad de Belo Horizonte-Brasil. Los resultados indican que las escalas verbales modificadas presentan una alta fiabilidad (alpha >0,80 asi como la presencia clara de un unico componente responsable por 81% y 64% de la variancia del WIC-III e WAIS-III respectivamente. Se ha concluido que las modificaciones efectuadas no han comprometido la estructura factorial de las escalas verbales. Por tanto, los profesionales psicólogos pueden utilizar las escalas modificadas para la evaluación de la inteligencia de personas portadoras de ceguera.Owing to the almost lack of a national research on psychological testing for the evaluation of blind people, a psychometric study has been developed with the WISC-III and WAIS

  20. Mathematics in Nature Modeling Patterns in the Natural World

    CERN Document Server

    Adam, John A

    2011-01-01

    From rainbows, river meanders, and shadows to spider webs, honeycombs, and the markings on animal coats, the visible world is full of patterns that can be described mathematically. Examining such readily observable phenomena, this book introduces readers to the beauty of nature as revealed by mathematics and the beauty of mathematics as revealed in nature.Generously illustrated, written in an informal style, and replete with examples from everyday life, Mathematics in Nature is an excellent and undaunting introduction to the ideas and methods of mathematical modeling. It illustrates how mathem

  1. As sementes geneticamente modificadas e o direito ao desenvolvimento

    Directory of Open Access Journals (Sweden)

    Milena Barbosa Melo

    2017-12-01

    Full Text Available O presente artigo apresenta como objeto de investigação a ligação entre os direitos da propriedade intelectual no contexto dos organismos geneticamente modificados (OGM´S. Objetivou-se, especificamente, responder inquietações acerca dos danos reais para os consumidores, bem como o lucro para as empresas multinacionais, sem desconsiderar, ainda, os efetivos danos ao meio ambiente e à saúde. Utilizou metodologia pautada em pesquisa bibliográfica e documental a partir do método hermenêutico fazendo uso da interpretação judicial-histórica. Conclui pela relevância da temática para efetivação do direito ao desenvolvimento, bem como pela urgência de uma regulamentação da biossegurança, de forma a permitir melhor sustentação aos OGM´s.

  2. On nature and bioethics.

    Science.gov (United States)

    Peterson, Paul Silas

    2010-01-01

    The account of nature and humanity's relationship to nature are of central importance for bioethics. The Scientific Revolution was a critical development in the history of this question and many contemporary accounts of nature find their beginnings here. While the innovative approach to nature going out of the seventeenth century was reliant upon accounts of nature from the early modern period, the Middle Ages, late-antiquity and antiquity, it also parted ways with some of the understandings of nature from these epochs. Here I analyze this development and suggests that some of the insights from older understandings of nature may be helpful for bioethics today, even if there can be no simple return to them.

  3. Matematica Natural.

    Science.gov (United States)

    Lozano, Patricia; Medearis, Linda

    Matematica Natural (Natural Mathematics) is a mathematics curriculum for young children based on the assumption that they learn mathematics through concrete, real life, relevant experiences and that educational differences rather than cultural differences influence math achievement. The curriculum uses hands-on materials and activities to teach…

  4. Natur formet

    DEFF Research Database (Denmark)

    Søberg, Martin

    2011-01-01

    Anmeldelse af Malene Hauxner, "Fra naturlig natur til SUPERNATUR – Europæisk landskabsarkitektur 1967-2007 set fra Danmark", Risskov: Ikaros Press, 2011.......Anmeldelse af Malene Hauxner, "Fra naturlig natur til SUPERNATUR – Europæisk landskabsarkitektur 1967-2007 set fra Danmark", Risskov: Ikaros Press, 2011....

  5. Natural radiation

    International Nuclear Information System (INIS)

    Feliciano, Vanusa Maria Delage

    2016-01-01

    Cosmic radiation, as well as cosmogenic radiation, terrestrial radiation, radon and thorium are introduced in this chapter 3. The distribution of natural radiation sources is treated, where the percentage distribution of the contribution relative to exposure to radiation from natural and artificial sources is also included

  6. Writing Nature

    Directory of Open Access Journals (Sweden)

    Kristin Asdal

    2014-06-01

    Full Text Available This special issue of the Nordic Journal of Science and Technology Studies is interested in how nature, in different versions and forms, is invited into our studies, analyses, and stories. How is it that we “write nature”? How is it that we provide space for, and actually describe the actors, agents, or surroundings, in our stories and analyses? The articles in the issue each deal with different understandings of both the practices of writing and the introduction of various natures into these. In this introduction to the issue the editors engage with actor-network theory as a material semiotic resource for writing nature. We propose to foreground actor-network theory as a writing tool, at the expense of actor-network theory as a distinct vocabulary. In doing this and pointing out the semiotic origins to material-semiotics we also want to problematize a clear-cut material approach to writing nature.

  7. The Anthropocene, Ethics, and the Nature of Nature

    Science.gov (United States)

    Trachtenberg, Z.

    2012-12-01

    For Earth scientists the Anthropocene has a strict meaning, tied to evidence that human activities have produced pervasive impacts on the Earth. But it is also significant for scholars outside the Earth sciences. Social scientists study the ways human societies transform the landscape to make it more suited to human habitation; the Anthropocene idea has already served to reveal conceptual linkages among physical and social science research programs. And the Anthropocene has important implications for normative theorists who enquire into the basis of ethical standards that, ideally, guide human activities within the environment. An influential view has held the condition of the Earth's systems in the absence of human interference as such a standard. This view emphasizes the preservation of environmental systems in (or restoration to) their "natural" condition—either because that condition is the most advantageous for human beings, or because those systems have an intrinsic moral value human beings ought to respect. However, Anthropocene research destabilizes the concept of nature. For the "natural" is typically opposed to the artificial, i.e. to the results of human action, and although nature obviously provides the context for human activity, that context is taken to be exogenously given. For virtually all of Earth's history, its systems were "natural" in this sense. However, since the appearance of life on Earth, organisms engaging in what is called niche construction have fundamentally transformed those systems up to the planetary scale. There is no reason to regard human niche construction (e.g. agriculture) as different in kind—though of course anthropogenic impacts are greater than the impacts of other species. It follows that the Anthropocene demands that we move away from an outlook based on a strict opposition between a "natural" condition and the human activities which change it, towards one that conceives of the natural not as a condition, but as a

  8. Plutonium in nature; Le plutonium dans la nature

    Energy Technology Data Exchange (ETDEWEB)

    Madic, C.

    1994-12-31

    Plutonium in nature comes from natural sources and anthropogenic ones. Plutonium at the earth surface comes principally from anthropogenic sources. It is easily detectable in environment. The plutonium behaviour in environment is complex. It seems necessary for the future to reduce releases in environment, to improve predictive models of plutonium behaviour in geosphere, to precise biological impact of anthropogenic plutonium releases.

  9. Utilização de Placas de polipropileno e fios de náilon na técnica de fixação espinhal segmentar modificada em uma jibóia Polypropylene plates and nylon suture in a modified technique of segmental spinal fixation in a redtail boa

    Directory of Open Access Journals (Sweden)

    Simone Borges Salgueiro De Simone

    2011-05-01

    Full Text Available Um exemplar adulto de Boa constrictor com histórico de atropelamento foi atendido no Hospital Veterinário. Exames clínico e radiográfico identificaram a presença de uma luxação no terço médio da coluna vertebral. O paciente foi submetido à estabilização cirúrgica da lesão, em que se avaliou a eficácia de uma variação da técnica de fixação espinhal segmentar modificada. O segmento foi estabilizado através da fixação e placas plásticas sob forma de hemicerclagem nos corpos vertebrais, com auxílio de fio de náilon n. 0 e a síntese tecidual finalizou o procedimento. No pós-operatório, instituiu-se a antibioticoterapia, curativos locais diários e restrição de espaço até a cicatrização total do ferimento. A variação da técnica mostrou ser eficaz no realinhamento e estabilização anatômica da luxação do segmento vertebral para a serpente em questão.An adult exemplar of Boa constrictor with a history of overthrowing was send to the Veterinary Hospital. Clinical and radiographic examinations identified the presence of a dislocation in the third middle of the spine. The patient was submitted to a surgical correction of the lesion, which evaluated the effectiveness of a variation of the modified technique of segmental spinal fixation. The segment was stabilized by fixing plastic plates in the form of hemicerclage in the vertebral bodies, with nylon n.0, and tissue synthesis completed the procedure. Postoperatively, it was instituted antibiotic therapy, daily curatives and space restrictions until the complete healing of the wound. The variation of the technique has proved to be safe and effective for the snake of this study, promoting the realignment and stabilization of the anatomical vertebral segment.

  10. Francis Bacon's natural history and the Senecan natural histories of early modern Europe.

    Science.gov (United States)

    Jalobeanu, Dana

    2012-01-01

    At various stages in his career, Francis Bacon claimed to have reformed and changed traditional natural history in such a way that his new "natural and experimental history" was unlike any of its ancient or humanist predecessors. Surprisingly, such claims have gone largely unquestioned in Baconian scholarship. Contextual readings of Bacon's natural history have compared it, so far, only with Plinian or humanist natural history. This paper investigates a different form of natural history, very popular among Bacon's contemporaries, but yet unexplored by contemporary students of Bacon's works. I have provisionally called this form of natural history'Senecan' natural history, partly because it took shape in the Neo-Stoic revival of the sixteenth-century, partly because it originates in a particular cosmographical reading of Seneca's Naturales quaestiones. I discuss in this paper two examples of Senecan natural history: the encyclopedic and cosmographical projects of Pierre de la Primaudaye (1546-1619) and Samuel Purchas (1577-1626). I highlight a number of similarities between these two projects and Francis Bacon's natural history, and argue that Senecan natural history forms an important aspect in the historical and philosophical background that needs to be taken into consideration if we want to understand the extent to which Bacon's project to reform natural history can be said to be new.

  11. Within city limits: nature and children's books about nature in the city

    Science.gov (United States)

    Leonard S. Marcus

    1977-01-01

    Many children's books give the impression that we must leave the city to be "in nature.'' This is a review of children's books about nature found within city limits. The books include a natural history of New York City; a guide to city wildflowers and other weeds; a book about city trees; a delightful inquiry into the true nature of the roach;...

  12. Avaliação preliminar do emprego de arenito zeolítico da região nordeste do Brasil como material pozolânico para cimento Portland Preliminary evaluation of sandstones from northeastern Brazil with pozzolanic properties for Portland cement

    Directory of Open Access Journals (Sweden)

    M. S. Picanço

    2011-12-01

    Full Text Available As zeolitas possuem atividade pozolânica normalmente sem a necessidade de ativação térmica, por isto têm sido empregadas na produção de cimento e concreto hidráulicos desde a época do império romano. Hoje em dia são utilizadas na fabricação do cimento Portland através da substituição do clinquer em percentuais que variam entre 5 e 20%, dependendo da reatividade e da finura da zeólita. Em razão disto, são muito importantes do ponto de vista econômico e ambiental, principalmente quando não necessitam de tratamento térmico para adquirirem caráter pozolânico satisfatório, porque reduzem significativamente a energia de produção do clinquer e a liberação de CO2 proveniente tanto da descarbonatação da calcita como da combustão de combustíveis fósseis. Contudo, dados sobre reservas de zeólitas naturais são escassos e imprecisos. No Brasil, não existe conhecimento sobre depósitos naturais de zeólitas que possam ser explorados comercialmente. No nordeste do Brasil existe a ocorrência de zeolitas sedimentares relacionadas a arenitos descoberta nos anos 2000. Estes arenitos são constituídos de quartzo, argilominerais e zeolitas naturais (estilbita. O objetivo geral desse trabalho foi avaliar se esta zeólita natural presente no arenito possui atividade pozolânica satisfatória para ser empregada como adição mineral em cimentos Portland. No programa experimental o arenito zeolítico passou por beneficiamento através da remoção, por peneiramento, do quartzo e outros minerais inertes, de modo a concentrar a zeólita estilbita e com isto verificar as propriedades pozolânicas deste mineral. No estudo experimental foram empregadas as técnicas de difração de raios X, calorimetria, ensaios químicos e de determinação da atividade pozolânica em argamassas de cal hidratada e cimento Portland. Os resultados mostraram que o arenito zeolítico acelerou a hidratação do cimento Portland devido a extrema finura do

  13. Framing nature

    NARCIS (Netherlands)

    Jansen, Peter

    2017-01-01

    This PhD thesis is about communication concerning nature in the Netherlands. The purpose of this exploratory study is to take both a theoretical and an empirical look at whether (implicit) religious elements play a role in this communication about nature in the Netherlands.

    In this PhD

  14. Defining Nature-Based Preschools

    Science.gov (United States)

    Larimore, Rachel

    2016-01-01

    Nature-based early childhood education. Nature-based preschool. Nature preschool. Forest kindergarten. Nature kindergarten. Waldkindergarten. Forest school. These are a few of the program terms currently being discussed among early childhood environmental education professionals in the United States. Why is there so much discussion about the names…

  15. Hallazgo de thomsonita en vetillas asociadas a tobas básicas palagonitizadas de la región de Farallones (Cuba oriental

    Directory of Open Access Journals (Sweden)

    Gerardo Orozco-Melgar

    2008-03-01

    Full Text Available Se reporta por primera vez la presencia de thomsonita, la cual se determinó junto a otras zeolitas, en vetillas que cortan a tobas carmelitas palagonitizadas que yacen interestratificadas con tobas verdes zeolitizadas, ricas en clinoptilolita, de la formación Sabaneta (Paleoceno-Eoceno Medio. Las tobas carmelitas contienen analcima y phillipsita y afloran principalmente en la localidad de Farallones, a unos 30 km al suroeste de la ciudad de Moa; constituyen posiblemente un miembro de composición más básica que las tobas verdes zeolitizadas. El empleo de técnicas de difracción de rayos X, microscopía de polarización, microsonda electrónica y fluorescencia de rayos X permitió establecer la presencia de  thomsonita de alta sílice y moderado desorden estructural. En las vetillas, junto a la thomsonita se encontró analcima, posiblemente como relicto de la roca de caja, y natrolita.

  16. Nephrotoxicity of Natural Products.

    Science.gov (United States)

    Nauffal, Mary; Gabardi, Steven

    2016-01-01

    The manufacture and sale of natural products constitute a multi-billion dollar industry. Nearly a third of the American population admit to using some form of complementary or alternative medicine, with many using them in addition to prescription medications. Most patients fail to inform their healthcare providers of their natural product use and physicians rarely inquire. Annually, thousands of natural product-induced adverse events are reported to Poison Control Centers nationwide. Natural product manufacturers are not responsible for proving safety and efficacy, as the FDA does not regulate them. However, concerns exist surrounding the safety of natural products. This review provides details on natural products that have been associated with renal dysfunction. We have focused on products that have been associated with direct renal injury, immune-mediated nephrotoxicity, nephrolithiasis, rhabdomyolysis with acute renal injury, hepatorenal syndrome, and common adulterants or contaminants that are associated with renal dysfunction. The potential for natural products to cause renal dysfunction is justifiable. It is imperative that natural product use be monitored closely in all patients. Healthcare practitioners must play an active role in identifying patients using natural products and provide appropriate patient education. © 2016 S. Karger AG, Basel.

  17. Realidad Virtual, Estado del arte y análisis crítico.

    OpenAIRE

    Mejía Luna, Jacqueline Narcisa

    2012-01-01

    Las alteraciones de la realidad están estrechamente vinculadas a las modificaciones de la percepción, la realidad ha sido modificada por teóricos de los nuevos medios de comunicación, artistas, filósofos, periodistas, médicos, tecnólogos, otros; y se la bifurca en realidad virtual, realidad aumentada, realidad mixta, realidad simulada, realidad artificial, realidad en capas y realidad mejorada.

  18. Nature-based integration

    DEFF Research Database (Denmark)

    Pitkänen, Kati; Oratuomi, Joose; Hellgren, Daniela

    Increased attention to, and careful planning of the integration of migrants into Nordic societies is ever more important. Nature based integration is a new solution to respond to this need. This report presents the results of a Nordic survey and workshop and illustrates current practices of nature...... based integration by case study descriptions from Denmark, Sweden Norway and Finland. Across Nordic countries several practical projects and initiatives have been launched to promote the benefits of nature in integration and there is also growing academic interest in the topic. Nordic countries have...... the potential of becoming real forerunners in nature based integration even at the global scale....

  19. Virtual nature environment with nature sound exposure induce stress recovery by enhanced parasympathetic activity

    DEFF Research Database (Denmark)

    Annerstedt, Matilda; Jönsson, Peter; Wallergård, Mattias

    2013-01-01

    . The group that recovered in virtual nature without sound and the control group displayed no particular autonomic activation or deactivation. The results demonstrate a potential mechanistic link between nature, the sounds of nature, and stress recovery, and suggest the potential importance of virtual reality......Experimental research on stress recovery in natural environments is limited, as is study of the effect of sounds of nature. After inducing stress by means of a virtual stress test, we explored physiological recovery in two different virtual natural environments (with and without exposure to sounds...... of nature) and in one control condition. Cardiovascular data and saliva cortisol were collected. Repeated ANOVA measurements indicated parasympathetic activation in the group subjected to sounds of nature in a virtual natural environment, suggesting enhanced stress recovery may occur in such surroundings...

  20. Modeling Child–Nature Interaction in a Nature Preschool: A Proof of Concept

    Directory of Open Access Journals (Sweden)

    Peter H. Kahn

    2018-05-01

    Full Text Available This article provides a proof of concept for an approach to modeling child–nature interaction based on the idea of interaction patterns: characterizations of essential features of interaction between humans and nature, specified abstractly enough such that countless different instantiations of each one can occur – in more domestic or wild forms – given different types of nature, people, and purposes. The model draws from constructivist psychology, ecological psychology, and evolutionary psychology, and is grounded in observational data collected through a time-sampling methodology at a nature preschool. Through using a nature language that emphasizes ontogenetic and phylogenetic significance, seven keystone interaction patterns are described for this nature preschool: using one’s body vigorously in nature, striking wood on wood, constructing shelter, being in solitude in nature, lying on earth, cohabiting with a wild animal, and being outside in weather. These 7 interactions patterns are then brought together with 13 other patterns published elsewhere to provide a total of 20 keystone interaction patterns that begin to fill out the model, and to show its promise. Discussion focuses on what the model aims to be in terms of both product and process, on what work the model can currently do, and how to further develop the model.

  1. Teorias da lei natural: Pufendorf e Rousseau Natural law theories: Pufendorf and Rousseau

    Directory of Open Access Journals (Sweden)

    Luiz Felipe Netto de Andrade e Silva Sahd

    2007-01-01

    Full Text Available O presente artigo tem como objetivo reconstruir argumentos centrais desenvolvidos por Jean-Jacques Rousseau. Contra Samuel Pufendorf, Rousseau defende que a justiça não é natural. Ele recusa todo compromisso com a lei natural tradicional para voltar à posição de Thomas Hobbes. Ora, no estado originário de natureza, os princípios racionais da lei natural que expõe Pufendorf não podem ser conhecidos, e, por conseguinte, quando puderem ser conhecidos, não serão aplicados por natureza.The present article aims at reconstructing Jean-Jacques Rousseau’s central arguments. Against Samuel Pufendorf, Rousseau maintains that justice is not natural, thereby rejecting the compromise with traditional natural law and wholly returning to the position of Thomas Hobbes. Now, in the original state of nature, Pufendorf’s rational principles of natural law cannot be known; later, when they may be known, they are not by nature enforced.

  2. Liquefied natural gas projects in Altamira: impacts on the prices of the natural gas; Proyectos de gas natural licuado en Altamira: impactos sobre los precios del gas natural

    Energy Technology Data Exchange (ETDEWEB)

    Perez Cordova, Hugo; Elizalde Baltierra, Alberto [Petroleos Mexicanos (PEMEX), (Mexico)

    2004-06-15

    The possible incorporation of new points of supply of natural gas to the Sistema National de Gasoductos (SNG) through the import of Liquified Natural Gas or (GNL) could cause an important modification in the national balance of supply-demand of the fuel and in its price, if large volumes are received. An analysis is presented of the possible impact that would have in the natural gas national market and in its prices the import of GNL made by the region of Altamira, Tamaulipas. [Spanish] La posible incorporacion de nuevos puntos de oferta de gas natural al Sistema Nacional de Gasoductos (SNG) a traves de la importacion de Gas Natural Licuado (GNL), podria provocar una modificacion importante en el balance oferta-demanda nacional del combustible y en su precio, si se reciben fuertes volumenes. Se presenta un analisis del posible impacto que tendria en el mercado nacional del gas natural y en sus precios la importacion de GNL realizada por la region de Altamira, Tamaulipas.

  3. NATURE-RURAL SETTLEMENT INTERACTIONS

    Directory of Open Access Journals (Sweden)

    Zehra Eminağaoğlu

    2006-04-01

    Full Text Available Conservation and management of natural environments are generally brought up upon adverse developments against nature in the humannature interactions. Although individual actions are often considered to be more immediate innatıre-related issuesi ecologic problems tend to spread in time and lead to reginol or even global problems. For this reason, it stands imperative that economic, ecologic and aesthetic values of the environment we live in be protected and used sustainably. Being the scene of nature and the environment landscape signifies the whole with living and nonliving entities where we live in. Dameged and destroyed landscape scenes particularly in urban areas necessitaites the reconsideration of human-nature relations and nature-frendly life style. This study investigates the rural settlements that show harmony with nature and reflects qualities of natural environments on the dwellings. Particularly, with the examples of drawing and pictures it examines the associatiation of rural settlements with nature as well as the use of the green as an occasional or spacial element.

  4. Natural gas in India

    International Nuclear Information System (INIS)

    Lefevre, Thierry; Todoc, Jessie L.

    1999-11-01

    Contains Executive Summary and Chapters on: Country background; Overview of the energy sector; Natural gas supply; Natural gas infrastructure; Natural gas infrastructure; Natural gas demand; Outlook-government policy reform and industry development, and Appendices on Global and regional energy and gas trends; Overview of India's investment policy, incentives and regulation; The ENRON Dabhol power project. (Author)

  5. US crude oil, natural gas, and natural gas liquids reserves 1996 annual report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-12-01

    The EIA annual reserves report series is the only source of comprehensive domestic proved reserves estimates. This publication is used by the Congress, Federal and State agencies, industry, and other interested parties to obtain accurate estimates of the Nation`s proved reserves of crude oil, natural gas, and natural gas liquids. These data are essential to the development, implementation, and evaluation of energy policy and legislation. This report presents estimates of proved reserves of crude oil, natural gas, and natural gas liquids as of December 31, 1996, as well as production volumes for the US and selected States and State subdivisions for the year 1996. Estimates are presented for the following four categories of natural gas: total gas (wet after lease separation), nonassociated gas and associated-dissolved gas (which are the two major types of wet natural gas), and total dry gas (wet gas adjusted for the removal of liquids at natural gas processing plants). In addition, reserve estimates for two types of natural gas liquids, lease condensate and natural gas plant liquids, are presented. Also included is information on indicated additional crude oil reserves and crude oil, natural gas, and lease condensate reserves in nonproducing reservoirs. A discussion of notable oil and gas exploration and development activities during 1996 is provided. 21 figs., 16 tabs.

  6. Natural Dietary Phytosterols.

    Science.gov (United States)

    Racette, Susan B; Lin, Xiaobo; Ma, Lina; Ostlund, Richard E

    2015-01-01

    Most clinical phytosterol studies are performed by adding purified supplements to smaller phytosterol amounts present in the natural diet. However, natural dietary phytosterols themselves may also have important effects on cholesterol metabolism. Epidemiological work using food frequency questionnaires to estimate dietary intake suggest that extremes of normal consumption may be associated with 3-14% changes in LDL cholesterol. Standardized food databases do not have enough phytosterol values to allow calculation of phytosterol intake for individuals outside of specialized studies. Natural diets contain phytosterol amounts ranging from less than 60 mg/2000 kcal to over 500 mg/2000 kcal. Physiological studies in which whole body cholesterol metabolism is investigated show large effects of natural dietary phytosterols on cholesterol absorption efficiency, cholesterol biosynthesis and cholesterol excretion which exceed the magnitude of changes in LDL cholesterol. The dual effects of natural phytosterols on both LDL-C and whole body cholesterol metabolism need to be considered in relating them to potential protection from coronary heart disease risk.

  7. US crude oil, natural gas, and natural gas liquids reserves, 1992 annual report

    Energy Technology Data Exchange (ETDEWEB)

    1993-10-18

    This report presents estimates of proved reserves of crude oil, natural gas, and natural gas liquids as of December 31, 1992, as well as production volumes for the United States, and selected States and State subdivisions for the year 1992. Estimates are presented for the following four categories of natural gas: total gas (wet after lease separation), its two major components (nonassociated and associated-dissolved gas), and total dry gas (wet gas adjusted for the removal of liquids at natural gas processing plants). In addition, two components of natural gas liquids, lease condensate and natural gas plant liquids, have their reserves and production data presented. Also included is information on indicated additional crude oil reserves and crude oil, natural gas, and lease condensate reserves in nonproducing reservoirs. A discussion of notable oil and gas exploration and development activities during 1992 is provided.

  8. US crude oil, natural gas, and natural gas liquids reserves, 1992 annual report

    International Nuclear Information System (INIS)

    1993-01-01

    This report presents estimates of proved reserves of crude oil, natural gas, and natural gas liquids as of December 31, 1992, as well as production volumes for the United States, and selected States and State subdivisions for the year 1992. Estimates are presented for the following four categories of natural gas: total gas (wet after lease separation), its two major components (nonassociated and associated-dissolved gas), and total dry gas (wet gas adjusted for the removal of liquids at natural gas processing plants). In addition, two components of natural gas liquids, lease condensate and natural gas plant liquids, have their reserves and production data presented. Also included is information on indicated additional crude oil reserves and crude oil, natural gas, and lease condensate reserves in nonproducing reservoirs. A discussion of notable oil and gas exploration and development activities during 1992 is provided

  9. Novel natural food antimicrobials.

    Science.gov (United States)

    Juneja, Vijay K; Dwivedi, Hari P; Yan, Xianghe

    2012-01-01

    Naturally occurring antimicrobial compounds could be applied as food preservatives to protect food quality and extend the shelf life of foods and beverages. These compounds are naturally produced and isolated from various sources, including plants, animals and microorganisms, in which they constitute part of host defense systems. Many naturally occurring compounds, such as nisin, plant essential oils, and natamycin, have been widely studied and are reported to be effective in their potential role as antimicrobial agents against spoilage and pathogenic microorganisms. Although some of these natural antimicrobials are commercially available and applied in food processing, their efficacy, consumer acceptance and regulation are not well defined. This manuscript reviews natural antimicrobial compounds with reference to their applications in food when applied individually or in combination with other hurdles. It also reviews the mechanism of action of selected natural antimicrobials, factors affecting their antimicrobial activities, and future prospects for use of natural antimicrobials in the food industry.

  10. Development of natural gas ocean transportation chain by means of natural gas hydrate (NGH)

    International Nuclear Information System (INIS)

    Nogami, T.; Oya, N.; Ishida, H.; Matsumoto, H.

    2008-01-01

    Recent studies in Japan have suggested that natural gas hydrate (NGH) transportation of natural gas is more economical than liquefied natural gas (LNG) transportation systems for small, medium and remote gas fields. Researchers in Japan have built a 600 kg per day NGH production and pelletizing plant and regasification facility. This paper discussed feasibility studies conducted in southeast Asia to determine the unit's commercialization potential with large natural gas-related businesses including shipping companies and electric power utilities. The total supply chain was compared with the corresponding liquefied natural gas (LNG) and compressed natural gas (CNG) supply chains. The study also examined natural gas reserves, energy policies, the positioning of natural gas supplies, and future forecasts of natural gas demand. A conceptual design for an NGH supply chain in Indonesia was presented. Results of the study have demonstrated that the NGH chain is an appropriate and economically feasible transportation method for many areas in southeast Asia. 8 refs., 10 figs

  11. Querying Natural Logic Knowledge Bases

    DEFF Research Database (Denmark)

    Andreasen, Troels; Bulskov, Henrik; Jensen, Per Anker

    2017-01-01

    This paper describes the principles of a system applying natural logic as a knowledge base language. Natural logics are regimented fragments of natural language employing high level inference rules. We advocate the use of natural logic for knowledge bases dealing with querying of classes...... in ontologies and class-relationships such as are common in life-science descriptions. The paper adopts a version of natural logic with recursive restrictive clauses such as relative clauses and adnominal prepositional phrases. It includes passive as well as active voice sentences. We outline a prototype...... for partial translation of natural language into natural logic, featuring further querying and conceptual path finding in natural logic knowledge bases....

  12. Culture inavouée dans la nature, nature soumise dans la culture

    Directory of Open Access Journals (Sweden)

    Claude Rivière

    2001-12-01

    Full Text Available On peut tirer de l'idée que l'on se fait de la nature, soit une apologie de l'ordre dans le cosmos, soit un argument pour justifier l'existence d'un Dieu maître de la foudre et des saisons, soit l'enchantement d'un retour à l'état de nature supposé non conflictuel, soit enfin une conviction matérialiste selon laquelle l'homme doit dompter sa gourmandise et assurer la survie optimale de l'environnement sans le polluer. La société n'est pas à penser comme une modalité d'oubli de la nature mais en rapport d'inclusion dans la nature. Après périple philosophique de Platon à Moscovici, on déviera dans le champ des artistes peignant d'après nature et dans celui des linguistes analysant ce qui est dit contre nature. C'est la culture qui oppose nature et convention, fait et norme, matière et liberté humaine. C'est elle aussi qui nous fournit notre vocabulaire, nos classifications et nos jugements de valeur à propos de la nature. Récemment un courant écologiste se pose en protecteur sourcilleux de l'environnement et en organisateur d'un développement durable, mais dans la deep ecology, on glisse vers le culte d'une biosphère de rêve.

  13. Natural gas deregulation

    International Nuclear Information System (INIS)

    Ronchi, M.

    1993-01-01

    With the aim of establishing realistic options for deregulation in the natural gas industry, this paper first considers the structural evolution of this industry and evidences how it differs from the petroleum industry with which it exhibits some essential characteristics in common. This comparison is made in order to stress that, contrary to popular belief, that which is without doubt good for the petroleum industry is not necessarily so also for the natural gas industry. The paper concludes with separate analyses of the natural gas markets in the principal industrialized countries. Arguments are provided to show that the 'soft' deregulation option for the natural gas industry is not feasible, and that 'total' deregulation instead, backed by the passing of a suitable package of anti-trust laws 'unbundling' the industry's four major activities, i.e., production, storage, primary and secondary distribution, is the preferable option. The old concept of guaranteed supplies for minor users of natural gas should give way to the laws of supply and demand governing inter-fuel competition ensured through the strict supervision of vigilance committees

  14. Okulo natural reactors

    International Nuclear Information System (INIS)

    Yamakawa, Minoru

    1993-01-01

    French CEA has reported in 1972 that natural nuclear reactors existed in Okulo uranium deposit in Gabon in Africa, that caused nuclear fission chain reaction (Okulo phenomena) spontaneously two billion years ago. The fission products and transuranic elements produced by the natural reactors have been preserved in strata without movement while subjected to geological phenomena for such very long years. 16 zones of the natural reactors have been discovered so far. The geological features of the Okulo uranium deposit are explained. The total amount of 235 U lost by the chain reaction was estimated to be about 6t, and the fission products were about 6t. The Okulo phenomena offered the valuable results of the synthetic formation disposal test that the nature has carried out for such long years. The significance of the study on natural analog is discussed. Organic substances and the mechanism of holding and movement of uranium and fission nuclides, the stability of uraninite and the age measurement of the deposit by Nd-Sm process are reported as the main results. (K.I.)

  15. Natural gas purchasing

    International Nuclear Information System (INIS)

    Freedenthal, C.

    1993-01-01

    In recent years, natural gas has gained new momentum because of changes in marketing and regulations. The gas industry has always received an inordinate amount of regulatory control starting at the well head where the gas is produced to the consuming burner tip. Regulations have drastically impacted the availability of gas. Changes in the marketing and regulations have made the natural gas market sensitive at the point of production, the well head. Now, with plentiful supply and ease of transportation to bring the gas from the producing fields to the consumer, natural gas markets are taking advantage of the changed conditions. At the same time, new markets are developing to take advantage of the changes. This section shows consumers, especially the energy planners for large buyers of fuel, the advantages, sources and new methods of securing natural gas supplies. Background on how natural gas is produced and marketed are given. This section lists marketing sources, regulatory agencies and information groups available to help buyers and consumers of this important fuel for US industries and residences. 7 figs., 8 tabs

  16. Natural gas marketing II

    International Nuclear Information System (INIS)

    Anon.

    1988-01-01

    This book covers all aspects of gas marketing, from the basic regulatory structure to the latest developments in negotiating agreements and locating markets. Topics include: Federal regulation of the gas industry; Fundamentals of gas marketing contracts; FERC actions encouraging competitive markets; Marketing conditions from the pipelines' perspective; State non-utility regulation of natural gas production, transportation, and marketing; Natural gas wellhead agreements and tariffs; Natural gas processing agreements; Effective management of producer's natural gas contracts; Producer-pipeline litigation; Natural gas purchasing from the perspective of industrial gas users; Gas marketing by co-owners: problems of disproportionate sales, gas balancing, and accounting to royalty owners; Alternatives and new directions in marketing

  17. U.S. crude oil, natural gas, and natural gas liquids reserves 1997 annual report

    Energy Technology Data Exchange (ETDEWEB)

    Wood, John H.; Grape, Steven G.; Green, Rhonda S.

    1998-12-01

    This report presents estimates of proved reserves of crude oil, natural gas, and natural gas liquids as of December 31, 1997, as well as production volumes for the US and selected States and State subdivisions for the year 1997. Estimates are presented for the following four categories of natural gas: total gas (wet after lease separation), nonassociated gas and associated-dissolved gas (which are the two major types of wet natural gas), and total dry gas (wet gas adjusted for the removal of liquids at natural gas processing plants). In addition, reserve estimates for two types of natural gas liquids, lease condensate and natural gas plant liquids, are presented. Also included is information on indicated additional crude oil reserves and crude oil, natural gas, and lease condensate reserves in nonproducing reservoirs. A discussion of notable oil and gas exploration and development activities during 1997 is provided. 21 figs., 16 tabs.

  18. Solitonic natural orbitals

    Science.gov (United States)

    Cioslowski, Jerzy

    2018-04-01

    The dependence of the natural amplitudes of the harmonium atom in its ground state on the confinement strength ω is thoroughly investigated. A combination of rigorous analysis and extensive, highly accurate numerical calculations reveals the presence of only one positive-valued natural amplitude ("the normal sign pattern") for all ω ≥1/2 . More importantly, it is shown that unusual, weakly occupied natural orbitals (NOs) corresponding to additional positive-valued natural amplitudes emerge upon sufficient weakening of the confinement. These solitonic NOs, whose shapes remain almost invariant as their radial positions drift toward infinity upon the critical values of ω being approached from below, exhibit strong radial localization. Their asymptotic properties are extracted from the numerical data and their relevance to calculations on fully Coulombic systems is discussed.

  19. Natural short sleeper

    Science.gov (United States)

    Sleep - natural short sleeper ... 7 to 9 hours of sleep each night. Short sleepers sleep less than 75% of what is normal for their age. Natural short sleepers are different from people who chronically do ...

  20. Grado de motivación por el aprendizaje en estudiantes de enfermería de una universidad pública.

    OpenAIRE

    Casanova-Rubio, María; Loli-Ponce, Rudi; Sandoval-Vegas, Miguel; Velásquez-Perales, Rosa

    2017-01-01

    Objetivos: Determinar el grado de Motivación por el Aprendizaje en estudiantes de Enfermería de la UNMSM en el año 2012. Material y Métodos: Investigación descriptiva, cuantitativa, de corte transversal. La muestra estuvo conformada por 68 estudiantes de Enfermería. El grado de motivación se determinó mediante la aplicación de un cuestionario tipo Likert modificada, sometida a juicio de expertos (p

  1. Tratamiento quirúrgico de disección de aorta torácica ascendente en sindrome de marfán.

    Directory of Open Access Journals (Sweden)

    Efraín Montesinos Mosqueira

    2007-04-01

    Full Text Available Se presentan 5 casos consecutivos de pacientes con Síndrome de Marfan y disección de aorta torácica ascendente, quienes fueron tratados quirúrgicamente con reemplazo de raíz aórtica (operación modificada de Bentall. Todos los pacientes tuvieron plena recuperación y al seguimiento post alta realizan actividades de la vida diaria sin problemas. (Rev Med Hered 2007;18:110-115.

  2. ASPECTOS CLIMÁTICOS DE LAS ZONAS ÁRIDAS DEL NORTE DE LA ALTIPLANICIE MEXICANA

    Directory of Open Access Journals (Sweden)

    Enriqueta García

    2017-05-01

    gráficas ombrotérmicas modificadas para diversos regímenes pluviométricos, a fin de cuantificar el número de meses secos, y se tratan de determinar las causas probables de la aridez de la región. El objetivo primordial del trabajo es proporcionar las bases climáticas, en la selección de alternativas para un uso mas adecuado del suelo de la región.

  3. Alternative ways to transport natural gas; Transporte alternativo de gas natural

    Energy Technology Data Exchange (ETDEWEB)

    Moura, N.R.; Campos, F.B. [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES)

    2008-07-01

    The Brazilian energy matrix has been showing a huge increase in the demand of natural gas due mainly to industries and power plants. Today the Brazilian gas market is supplied with gas produced by PETROBRAS and imported from Bolivia. To increase the Brazilian gas supply, on the short and middle term, PETROBRAS will import LNG (liquefied natural gas) and exploit the new offshore fields discovered on the pre-salt area. The only proven technology available today to bring this offshore gas to the market is the pipeline, but its costs for the pre-salt area are high enough to keep the solution economically attractive. So, PETROBRAS are evaluating and developing alternative ways to transport offshore gas, such as LNG, CNG (Compressed Natural Gas), GTS (Gas-to-Solids or Natural Gas Hydrates) and ANG (Adsorbed Natural Gas). Using information available in the literature, this paper analyses the main concepts of CNG and LNG floating unities. This paper also presents the PETROBRAS R and D results on ANG and GTS aiming at offshore application. (author)

  4. Natural gas annual 1991

    International Nuclear Information System (INIS)

    1992-01-01

    The Natural Gas Annual provides information on the supply and disposition of natural gas to a wide audience including industry, consumers, Federal and State agencies, and educational institutions. The 1991 data are presented in a sequence that follows natural gas (including supplemental supplies) from its production to its end use. Tables summarizing natural gas supply and disposition form 1987 to 1991 are given for each Census Division and each State. Annual historical data are shown at the national level

  5. Natural gas annual 1993

    International Nuclear Information System (INIS)

    1994-01-01

    The Natural Gas Annual provides information on the supply and disposition of natural gas to a wide audience including industry, consumers, Federal and State agencies, and educational institutions. The 1993 data are presented in a sequence that follows natural gas (including supplemental supplies) from its production to its end use. Tables summarizing natural gas supply and disposition from 1989 to 1993 are given for each Census Division and each State. Annual historical data are shown at the national level

  6. Natural radiation environment

    International Nuclear Information System (INIS)

    Vohra, K.G.; Mishra, U.C.; Pillai, K.C.; Sadasivan, S.

    1982-01-01

    The volume presented contains papers presented at the Second Special Symposium on Natural Radiation Environment held at Bombay, India, during January 1981. The papers deal with such topics as : 1)high natural radiation background areas; 2)environmental natural radioactivity; 3)measurement techniques; 4)technologically enhanced radioactivity; 5)indoor radiation environment; 6)radon and daughters in ambient air, and 7)applications in Geosciences. Each of the 87 papers presented has been abstracted and indexed for the U.S. Department of Energy Technical Information Center's Energy Data Base

  7. Enhance Nature Exploration with Technology

    Science.gov (United States)

    Holloway, Patricia; Mahan, Carol

    2012-01-01

    Kids and nature seem like a natural combination, but what was natural a generation ago is different today. Children are spending less time outdoors but continue to need nature for their physical, emotional, and mental development. This fact has led author Richard Louv to suggest that today's children are suffering from "nature-deficit disorder"…

  8. TECHNOLOGY VS NATURE: HUMAN ERROR IN DEALING WITH NATURE IN CRICHTON'S JURASSIC PARK

    Directory of Open Access Journals (Sweden)

    Sarah Prasasti

    2000-01-01

    Full Text Available Witnessing the euphoria of the era of biotechnology in the late twentieth century, Crichton exposes the theme of biotechnology in his works. In Jurassic Park, he voices his concern about the impact of the use of biotechnology to preserve nature and its living creatures. He further describes how the purpose of preserving nature and the creatures has turned out to be destructive. This article discusses Crichton's main character, Hammond, who attempts to control nature by genetically recreating the extinct fossil animals. It seems that the attempt ignores his human limitations. Although he is confident that has been equipped with the technology, he forgets to get along with nature. His way of using technology to accomplish his purpose proves not to be in harmony with nature. As a consequence, nature fights back. And he is conquered.

  9. 21 CFR 172.510 - Natural flavoring substances and natural substances used in conjunction with flavors.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Natural flavoring substances and natural substances used in conjunction with flavors. 172.510 Section 172.510 Food and Drugs FOOD AND DRUG ADMINISTRATION....510 Natural flavoring substances and natural substances used in conjunction with flavors. Natural...

  10. Natural gas annual 1995

    International Nuclear Information System (INIS)

    1996-11-01

    The Natural Gas Annual provides information on the supply and disposition of natural gas to a wide audience including industry, consumers, Federal and State agencies, and educational institutions. The 1995 data are presented in a sequence that follows natural gas (including supplemental supplies) from its production to its end use. This is followed by tables summarizing natural gas supply and disposition from 1991 to 1995 for each Census Division and each State. Annual historical data are shown at the national level

  11. Asociación entre la contaminación del ambiente laboral y las enfermedades respiratorias en una empresa minera Association between the working environment pollution and the respiratory diseases in a mining enterpri

    Directory of Open Access Journals (Sweden)

    Guillermo López Espinosa

    2005-12-01

    Full Text Available Se realizó un estudio observacional en la Mina-Planta de Zeolita, perteneciente al municipio de Ranchuelo, provincia de Villa Clara, en el año 2003, que tuvo como objetivo demostrar la asociación existente entre la contaminación del ambiente laboral y las enfermedades respiratorias en los trabajadores. Para ello se recolectó información de la morbilidad laboral y se efectuó el estudio químico sanitario de la zona de trabajo, donde se encontró que el polvo de zeolita en el aire sobrepasaba los límites admisibles de exposición. El 61,9 % de los certificados médicos emitidos por enfermedades respiratorias fueron en los meses de alta producción, y un 76,4 % correspondió a trabajadores del área de mayor exposición al polvo, en la que además el 69,3 % de los trabajadores mantiene de 7 a 14 años de labor en el centro. En el área de menor exposición el riesgo de tener incapacidad laboral temporal por enfermedades respiratorias es de 5,50 veces. La contaminación del ambiente laboral constituyó un factor favorecedor para el desarrollo de afecciones respiratorias, por lo que recomendamos mejorar las condiciones de operación en los procesos tecnológicos con relación al sistema de despolvorización.An observational study was conducted in the Zeolite Mine-Plant of Ranchuelo municipality, province of Villa Clara, in 2003, aimed at showing the association existing between the working environment pollution and the respiratory diseases in the workers. To this end, information on working morbidity was collected and a chemical sanitary study of the working zone was undertaken. It was found that zeolite dust exceeded the admissible levels of exposure. 61.9 % of the medical certificates for respiratory diseases were issued in the months of high production. 76.4 % corresponded to workers from the area most exposed to dust, where 69.3 % of them have worked for 7-14 years. In the area of less exposure, the risk for presenting temporary working

  12. UNA COMPARACIÓN DE RENDIMIENTO ENTRE ORACLE Y MONGODB

    Directory of Open Access Journals (Sweden)

    Ismael Leonardo Vera Puerto

    2016-01-01

    Full Text Available Este trabajo tuvo por objetivo evaluar la arena (A, el carbón activado (CA y la zeolita (Z como materiales filtrantes para valorar su efecto en reutilización para agricultura de aguas residuales tratadas de un ambiente árido. Para esto se construyeron 7 columnas de filtración: a columna 1, 100 % de Z, b columna 2, 100 % de CA (origen A, c columna 3, 100 % de CA (origen B, d columna 4, 100 % de A, e columna 5, 50 % de Z sobre 50 % de CA, f columna 6, 50 % de A sobre 50 % de CA, y g columna 7, 50 % de Z sobre 50 % de A. En el afluente y efluente se evaluó boro (B, cloruro (Cl-, sulfato (SO4 -2, calcio (Ca+2, conductividad eléctrica (CE, pH y temperatura (T, junto a un grupo de metales pesados (As, Cd, Cu, Fe, Mn, Pb y Zn. Los resultados mostraron cómo el CA (de origen A o B es capaz de remover boro a valores por debajo de 0,75 mg/L. Sin embargo, en una etapa inicial (primera quincena los efluentes a este medio filtrante, presentaron un valor de CE mayor a 2,5 dS/m, y de pH mayor a 8,4, lo que seguramente traerá problemas para su aplicación en riego de cultivos. Por su parte, la arena, al ser de la región, presenta problemas de lixiviación de elementos, como el arsénico y el sodio, por lo que no debería utilizarse como material filtrante. Por el contrario, el único medio evaluado que tiene potencial de ser aplicado en la reducción de la salinidad es la zeolita. Este material filtrante, sin mezcla con otro, fue capaz de reducir hasta un 20 % el valor de la CE sin tener un efecto negativo en ninguno de los otros parámetros evaluados en este estudio, y además, sin mostrar un estado de saturación durante el tiempo de operación evaluado. En el caso de las columnas que utilizaron mezclas de materiales, no existe un efecto sinérgico para la eliminación de los parámetros de calidad del agua evaluados.

  13. Constructing nature behind the glass

    Directory of Open Access Journals (Sweden)

    Samuel J.M.M. Alberti

    2008-07-01

    Full Text Available By way of introducing this special issue of Museum and Society, ‘Constructing nature behind glass’, this paper first surveys the literature devoted to analyses of natural history objects and collections. Such work is to be found in interesting places – not only in museum studies, history of science, and professional museum literature, but also in visual studies, anthropology and cultural geography. After exploiting this writing for different perspectives on the cultural and practical construction of museum nature, this paper moves on to consider one popular topic, taxidermy. The ambiguous nature of taxidermic mounts, or ‘remnant models’, leads to a discussion of the relative status of specimen and artefact. I identify four configurations of their relationship: museum nature as opposed to material culture; museum nature as material culture; museum nature and material culture sharing parallel processes; and finally, museum nature and material culture entangled. All offer perspectives on the construction of nature and culture behind glass.

  14. Natural gas pricing

    International Nuclear Information System (INIS)

    Freedenthal, C.

    1993-01-01

    Natural gas pricing is the heart and soul of the gas business. Price specifically affects every phase of the industry. Too low a price will result in short supplies as seen in the mid-1970s when natural gas was scarce and in tight supply. To fully understand the pricing of this energy commodity, it is important to understand the total energy picture. In addition, the effect and impact of world and US economies, and economics in general are crucial to understanding natural gas pricing. The purpose of this presentation will be to show the parameters going into US natural gas pricing including the influence of the many outside industry factors like crude oil and coal pricing, market drivers pushing the gas industry, supply/demand parameters, risk management for buyers and sellers, and other elements involved in pricing analysis

  15. Natural gas benefits

    International Nuclear Information System (INIS)

    1999-01-01

    The General Auditor in the Netherlands studied the natural gas policy in the Netherlands, as has been executed in the past decades, in the period 1997-1999. The purpose of the study is to inform the Dutch parliament on the planning and the backgrounds of the natural gas policy and on the policy risks with respect to the benefits for the Dutch State, taking into account the developments in the policy environment. The final conclusion is that the proposed liberalization of the national natural gas market will result in a considerable deprivation of income for the State in case the benefit policy is not adjusted. This report includes a reaction of the Dutch Minister of Economic Affairs and an afterword of the General Auditor. In the appendix an outline is given of the natural gas policy

  16. U.S. crude oil, natural gas, and natural gas liquids reserves 1995 annual report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-11-01

    The EIA annual reserves report series is the only source of comprehensive domestic proved reserves estimates. This publication is used by the Congress, Federal and State agencies, industry, and other interested parties to obtain accurate estimates of the Nation`s proved reserves of crude oil, natural gas, and natural gas liquids. These data are essential to the development, implementation, and evaluation of energy policy and legislation. This report presents estimates of proved reserves of crude oil, natural gas, and natural gas liquids as of December 31, 1995, as well as production volumes for the US and selected States and State subdivisions for the year 1995. Estimates are presented for the following four categories of natural gas: total gas (wet after lease separation), nonassociated gas and associated-dissolved gas (which are the two major types of wet natural gas), and total dry gas (wet gas adjusted for the removal of liquids at natural gas processing plants). In addition, reserve estimates for two types of natural gas liquids, lease condensate and natural gas plant liquids, are presented. Also included is information on indicated additional crude oil reserves and crude oil, natural gas, and lease condensate reserves in nonproducing reservoirs. A discussion of notable oil and gas exploration and development activities during 1995 is provided. 21 figs., 16 tabs.

  17. Natural gas annual 1991

    International Nuclear Information System (INIS)

    1993-01-01

    The Natural Gas Annual 1991 provides information on the supply and disposition of natural gas to a wide audience including industry, consumers Federal and State agencies, and education institutions. This report, the Natural Gas Annual 1991 Supplement: Company Profiles, presents a detailed profile of selected companies

  18. Closer to Nature?

    DEFF Research Database (Denmark)

    Borkfelt, Sune; Kondrup, Sara; Röcklinsberg, Helena

    2015-01-01

    discourses in order to sell one image of animal welfare in intensive animal production while the actual production at the same time presupposes a quite different paradigm of animal welfare. Specifically, product advertising utilizes representations tied to concepts of naturalness in depictions of both animal...... lives and product processes as “natural”. Product marketing suggests a coherence between nature, production process (farm, animal), and end product, thereby creating associations that the lives of production animals are lived in nature and that their products bring a wholesome and sustainable...

  19. Nature as Measure

    DEFF Research Database (Denmark)

    Peters, Terri

    2011-01-01

    The potential for biomimicry lies far beyond the direct imitation of natural forms. Guest-editor Terri Peters describes how Janine Benyus, the biologist and innovation consultant, is using biomimicry to create performance metrics from natural technologies and processes for assessing aspects...

  20. Incremental natural gas resources through infield reserve growth/secondary natural gas recovery

    Energy Technology Data Exchange (ETDEWEB)

    Finley, R.J.; Levey, R.A.; Hardage, B.A.

    1993-12-31

    The primary objective of the Infield Reserve Growth/Secondary Natural Gas Recovery (SGR) project is to develop, test, and verify technologies and methodologies with near- to midterm potential for maximizing the recovery of natural gasfrom conventional reservoirs in known fields. Additional technical and technology transfer objectives of the SGR project include: To establish how depositional and diagenetic heterogeneities in reservoirs of conventional permeability cause reservoir compartmentalization and, hence, incomplete recovery of natural gas. To document examples of reserve growth occurrence and potential from fluvial and deltaic sandstones of the Texas gulf coast basin as a natural laboratory for developing concepts and testing applications to find secondary gas. To demonstrate how the integration of geology, reservoir engineering, geophysics, and well log analysis/petrophysics leads to strategic recompletion and well placement opportunities for reserve growth in mature fields. To transfer project results to a wide array of natural gas producers, not just as field case studies, but as conceptual models of how heterogeneities determine natural gas flow units and how to recognize the geologic and engineering clues that operators can use in a cost-effective manner to identify incremental, or secondary, gas.

  1. Natural gas annual 1997

    International Nuclear Information System (INIS)

    1998-10-01

    The Natural Gas Annual provides information on the supply and disposition of natural gas to a wide audience including industry, consumers, Federal and State agencies, and educational institutions. The 1997 data are presented in a sequence that follows natural gas (including supplemental supplies) from its production to its end use. This is followed by tables summarizing natural gas supply and disposition from 1993 to 1997 for each Census Division and each State. Annual historical data are shown at the national level. 27 figs., 109 tabs

  2. Natural gas annual 1997

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-10-01

    The Natural Gas Annual provides information on the supply and disposition of natural gas to a wide audience including industry, consumers, Federal and State agencies, and educational institutions. The 1997 data are presented in a sequence that follows natural gas (including supplemental supplies) from its production to its end use. This is followed by tables summarizing natural gas supply and disposition from 1993 to 1997 for each Census Division and each State. Annual historical data are shown at the national level. 27 figs., 109 tabs.

  3. Natural Ventilation in Atria

    DEFF Research Database (Denmark)

    Svidt, Kjeld; Heiselberg, Per; Hendriksen, Ole Juhl

    This case study comprises a monitoring programme as well as a Computational Fluid Dynamics (CFD) analysis of a natural ventilated atrium. The purpose has been to analyse the performance of a typical natural ventilation system in Denmark under both summer and winter conditions.......This case study comprises a monitoring programme as well as a Computational Fluid Dynamics (CFD) analysis of a natural ventilated atrium. The purpose has been to analyse the performance of a typical natural ventilation system in Denmark under both summer and winter conditions....

  4. Growing natural gas usage

    International Nuclear Information System (INIS)

    Saarni, T.

    1996-01-01

    Finnish natural gas usage topped the 3.3 billion cubic metre mark last year, up 3.6 % on the 1994 figure. Growth has increased now for 12 years in a row. Thanks to offtake by large individual users, the pipeline network has been expanded from South-East Finland to the Greater Helsinki area and central southern Finland. Natural gas plays a much larger role in this region than the 10 % accounted for by natural gas nationally would indicate. The growth in the share of Finland's energy use accounted for by natural gas has served to broaden the country's energy supply base. Natural gas has replaced coal and oil, which has considerably reduced the level of emissions resulting form energy generation

  5. A natural compromise: a moderate solution to the GMO & "natural" labeling disputes.

    Science.gov (United States)

    Amaru, Stephanie

    2014-01-01

    In the United States, genetically modified (GM) foods are labeled no differently from their natural counterparts, leaving consumers with no mechanism for deciphering genetically modified food content. The Food and Drug Administration (FDA) has not formally defined the term "natural," which is frequently used on food labels despite consumer confusion as to what it means. The FDA should initiate a notice and comment rulemaking addressing the narrow issue of whether use of the word "natural" should be permitted oil GM food labels. Prohibition of the use of"natural" on genetically modified foods would mitigate consumer deception regarding genetically modified food content without significantly disadvantaging genetically modified food producers.

  6. US crude oil, natural gas, and natural gas liquids reserves: 1990 annual report

    International Nuclear Information System (INIS)

    1991-09-01

    The primary focus of this report is to provide an accurate estimate of US proved reserves of crude oil, natural gas, and natural gas liquids. These estimates were considered essential to the development, implementation, and evaluation of natural energy policy and legislation. In the past, the government and the public relied upon industry estimates of proved reserves. These estimates were prepared jointly by the American Petroleum Institute (API) and the American Gas Association (AGA) and published in their annual report, Reserves of Crude Oil, Natural Gas Liquids, and Natural Gas in the United States and Canada. However, API and AGA ceased publication of reserves estimates after their 1979 report. By the mid-1970's, various federal agencies had separately established programs to collect data on, verify, or independently estimate domestic proved reserves of crude oil or natural gas. Each program was narrowly defined to meet the particular needs of the sponsoring agency. In response to recognized need for unified, comprehensive proved reserves estimates, Congress in 1977 required the Department of Energy to prepare such estimates. To meet this requirement, the EIA's reserves program was undertaken to establish a unified, verifiable, comprehensive, and continuing statistical series for proved reserves of crude oil and natural gas. The program was expanded to include proved reserves of natural gas liquids in the 1979 report. 36 refs., 11 figs., 16 tabs

  7. Is disease a natural kind?

    Science.gov (United States)

    D'Amico, R

    1995-10-01

    In The Nature of Disease, Lawrie Reznek argues that disease is not a natural kind term. I raise objections to Reznek's two central arguments for establishing that disease is not a natural kind. In criticizing his a priori, conceptual argument against naturalism, I argue that his conclusion rests on a weaker argument that appeals to the empirical diversity in the symptoms and manifestations of disease. I also raise questions about the account of natural kinds which Reznek utilizes and his point that conventions for classification are excluded by there being natural kinds.

  8. Perfil funcional de locomoção em um grupo de pacientes com lesão medular atendidos em um centro de reabilitação Perfil funcional de locomoción en un grupo de pacientes con lesión medular atendidos en un centro de rehabilitación Functional ambulation profile in a group of spinal cord injured patients attended at a rehabilitation center

    Directory of Open Access Journals (Sweden)

    Ana Cristina Franzoi

    2009-12-01

    Full Text Available OBJETIVO: descrever o perfil de locomoção de um grupo de pacientes com lesão medular (LM, correlacionando-o com as características da amostra. MÉTODOS: setenta pacientes (50 com LM traumática e 20 com LM não-traumática. Instrumentos: Classificação Funcional da Marcha Modificada (CFMM, WISCI-II, Escala de Ashworth Modificada (EAM, Classificação AIS, Lower Extremities Muscle Score (AIS-LEMS. Estatística: descritiva, comparação entre grupos, testes de correlação considerando pOBJETIVO: describir el perfil de locomoción de un grupo de pacientes con lesión medular (LM, correlacionándolo con las características de la muestra. MÉTODOS: setenta pacientes (50 con LM traumática y 20 con LM no traumática. Instrumentos: Clasificación Funcional de la Marcha Modificada (CFMM, WISCI-II, Escala de Ashworth Modificada (EAM, Clasificación AIS, AIS Lower Extremities Muscle Score (AIS-LEMS. Estadística: descriptiva, comparación entre grupos, testes de correlación considerando un pOBJECTIVE: to describe the locomotion profile of a group of spinal cord injured (SCI patients and its correlation with the sample features. METHODS: seventy patients (50 with traumatic SCI and 20 non-traumatic were assessed. Instruments: Modified Functional Ambulation Classification (MFAC, Walking Index for Spinal Cord Injury II (WISCI-II, Modified Ashworth Scale (MAS, American Spinal Injury Association Impairment Scale (AIS and AIS Lower Extremities Muscle Score (AIS-LEMS. Statistics: descriptive, comparison between groups, correlation tests (considering p<0,05. RESULTS: average values were: age: 36 years, 72.9% males, average time of lesion 4.7 years. AIS A, 38.6%; AIS B, 10%; AIS C, 22.8%; AIS D, 28.6%. Level of lesion: 32.8% cervical, 52.9% thoracic, 14.3% lumbar. More prevalent etiologies: gunshot wounds 30% and car accidents 18%. MFAC: Non-ambulation, 34.3%; Therapeutic ambulation 20%, Household ambulation 12.8%, community ambulation (32.9%; WISCI-II: 7

  9. Emancipating Nature

    DEFF Research Database (Denmark)

    Munk, Anders Kristian

    2012-01-01

    The issue of riverine flooding in the UK is closely tied up with computer simulations. Arguably, these modelling practices are ripe with the anticipation of nature. They aspire to pre-empt it, hence expect it to be ‘out there’, and ultimately work through formalized distillations of it – hydrodyn......The issue of riverine flooding in the UK is closely tied up with computer simulations. Arguably, these modelling practices are ripe with the anticipation of nature. They aspire to pre-empt it, hence expect it to be ‘out there’, and ultimately work through formalized distillations...... of it – hydrodynamic equations – which have their own anticipations and place their own demands on their modellers. Through the experience of a flood modelling apprenticeship I argue that the taking-place of such anticipations paradoxically relies on the birth of a hybrid, the model-modeller, and thus on a nature...

  10. LNG (Liquefied Natural Gas): the natural gas becoming a world commodity and creating international price references; GNL (Gas Natural Liquefeito): o gas natural se tornando uma commodity mundial e criando referencias de preco internacionais

    Energy Technology Data Exchange (ETDEWEB)

    Demori, Marcio Bastos [PETROBRAS, Rio de Janeiro, RJ (Brazil). Coordenacao de Comercializacao de Gas e GNL; Santos, Edmilson Moutinho dos [Universidade de Sao Paulo (USP), SP (Brazil). Inst. de Eletrotecnica e Energia. Programa Interunidades de Pos-Graduacao em Energia (PIPGE)

    2004-07-01

    The transportation of large quantities of natural gas through long distances has been done more frequently by Liquefied Natural Gas (LNG). The increase of natural gas demand and the distance of major reserves, allied to technological improvements and cost reduction through LNG supply chain, have triggered the expressive increase of LNG world market This paper tries to evaluate the influence that LNG should cause on natural gas world market dynamic, analyzing the tendency of gas to become a world commodity, creating international price references, like oil and its derivates. For this, are shown data as natural gas world reserves, the participation of LNG in natural gas world market and their increase. Furthermore, will be analyzed the interaction between major natural gas reserves and their access to major markets, still considering scheduled LNG projects, the following impacts from their implementation and price arbitrage that should be provoked on natural gas markets. (author)

  11. God, design, and naturalism: Implications of methodological naturalism in science for science-religion relation

    Directory of Open Access Journals (Sweden)

    Piotr Bylica

    2015-03-01

    Full Text Available The aim of this paper is to analyze the implications flowing from adopting methodological naturalism in science, with special emphasis on the relation between science and religion. Methodological naturalism, denying supernatural and teleological explanations, influences the content of scientific theories, and in practice leads to vision of science as compatible with ontological naturalism and in opposition to theism. Ontological naturalism in turn justifies the acceptance of methodological naturalism as the best method to know the reality. If we accept realistic interpretation of scientific theories, then methodological naturalism conflicts science with religion. Theistic evolution does not seem to be a proper way to reconcile Darwinism and methodological naturalism with theism. Many of such propositions are boiled down to deism. Although evolution can be interpreted theistically, it is not the way in which majority of modern scientists and respectable scientific institutions understand it.

  12. A natural adsorbent for natural gas industry; Um adsorvente nacional para a industria do gas natural

    Energy Technology Data Exchange (ETDEWEB)

    Cachina, G.H.A.B.; Silveira, V.R.; Melo, D.M.A. [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil); Balthar, A.R.; Oliveira, V.M.; Bayer, M.M. [CTGAS - Centro de Tecnologias do Gas, Natal, RN (Brazil); Barbosa, C.M.M. [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil)

    2004-07-01

    One the natural pollutants in the natural gas considered critical in reference to the corrosion is the H{sub 2}S. Its presence depends on the origin, as well as the own process used in the gas treatment, it can bring problems to the pipes and the final applications of natural gas (NG). The National Petroleum Agency (ANP) in its entrance number 104/02, establishes that the quantity of H{sub 2}S in NG, of national or imported origin, commercialized at the country can only be at the most 10 - 15 mg/m{sup 3}. In the Natural Gas Processing Unit (UPGN) different methods are used for the removal of H{sub 2}S, the absorption process (e.g. with aminas, Sulfinol{sup R} process) or for adsorption in tower filled with activated coal, zeolites and Sulfatreat{sup R}. In this work, the adsorbent material used is the mineral clay Paligorsquita. That class of clay minerals characterized by pores and a crystalline structure containing Tetrahedral layers linked by chains of longitudinal secondary lines. The typical unitary cell is formed basically by moisturized oxides of aluminum, Sicilian and magnesium of (Mg, Al)5SiO2O(OH)2(H20)4.4H20, with Mg specially located in octahedral sites. (author)

  13. Nature as Dissonant Heritage

    DEFF Research Database (Denmark)

    Clemmensen, Thomas Juel

    2014-01-01

    accepts that nature it not existing outside culture as something that be restored to its original state, but a contemporary product created and managed with certain objectives in mind, nature restoration like heritage production are prone to same kind of dissonance – our nature is not necessary...... their nature. According to Ashworth cultural dissonance can be managed in a number of different way depending on which type of plural society is preferred. Many of these management strategies consciously or unconsciously involve some form of denial, neglect, destruction, reinterpretation or marginalizing...

  14. Natural gas monthly, April 1999

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-05-06

    The Natural Gas Monthly (NGM) highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. From time to time, the NGM features articles designed to assist readers in using and interpreting natural gas information. There are two feature articles in this issue: Natural gas 1998: Issues and trends, Executive summary; and Special report: Natural gas 1998: A preliminary summary. 6 figs., 28 tabs.

  15. Symmetries in nature

    International Nuclear Information System (INIS)

    Mainzer, K.

    1988-01-01

    Symmetry, disymmetry, chirality etc. are well-known topics in chemistry. But they cannot only be found on the molecular level of matter. Atoms and elementary particles in physics are also characterized by particular symmetry groups. Even living organisms and populations on the macroscopic level have functional properties of symmetry. The whole physical, chemical, and biological evolution seems to be regulated by the emergence of new symmetries and the breaking down of old ones. One is reminded of Heisenberg's famous statement: 'Die letzte Wurzel der Erscheinungen ist also nicht die Materie, sondern das mathematische Gesetz, die Symmetrie, die mathematische Form' (Wandlungen in den Grundlagen der Naturwissenschaften, 1959). Historically the belief in symmetry and simplicity of nature has a long philosophical tradition from the Pythagoreans, Plato and Greek astronomers to Kepler and modern scientists. Today, 'symmetries in nature' is a common topic of mathematics, physics, chemistry, and biology. A lot of Nobel prizes were given in honour of inquiries concerning symmetries in nature. The fascination of symmetries is not only motivated by science, but by art and religion too. Therefore 'symmetris in nature' is an interdisciplinary topic which may help to overcome C.P. Snow's 'Two Cultures' of natural sciences and humanities. (author) 17 refs., 21 figs

  16. Symmetries in nature

    Energy Technology Data Exchange (ETDEWEB)

    Mainzer, K

    1988-05-01

    Symmetry, disymmetry, chirality etc. are well-known topics in chemistry. But they cannot only be found on the molecular level of matter. Atoms and elementary particles in physics are also characterized by particular symmetry groups. Even living organisms and populations on the macroscopic level have functional properties of symmetry. The whole physical, chemical, and biological evolution seems to be regulated by the emergence of new symmetries and the breaking down of old ones. One is reminded of Heisenberg's famous statement: 'Die letzte Wurzel der Erscheinungen ist also nicht die Materie, sondern das mathematische Gesetz, die Symmetrie, die mathematische Form' (Wandlungen in den Grundlagen der Naturwissenschaften, 1959). Historically the belief in symmetry and simplicity of nature has a long philosophical tradition from the Pythagoreans, Plato and Greek astronomers to Kepler and modern scientists. Today, 'symmetries in nature' is a common topic of mathematics, physics, chemistry, and biology. A lot of Nobel prizes were given in honour of inquiries concerning symmetries in nature. The fascination of symmetries is not only motivated by science, but by art and religion too. Therefore 'symmetris in nature' is an interdisciplinary topic which may help to overcome C.P. Snow's 'Two Cultures' of natural sciences and humanities. (author) 17 refs., 21 figs.

  17. Natural gas in Mexico

    International Nuclear Information System (INIS)

    Ramirez, M.

    1999-01-01

    A series of overhead viewgraphs accompanied this presentation which focused on various aspects of the natural gas industry in Mexico. Some of the viewgraphs depicted statistics from 1998 regarding natural gas throughput from various companies in North America, natural gas reserves around the world, and natural gas reserves in Mexico. Other viewgraphs depicted associated and non-associated natural gas production from 1988 to 1998 in million cubic feet per day. The Burgos Basin and the Cantarell Basin gas production from 1997 to 2004 was also depicted. Other viewgraphs were entitled: (1) gas processing infrastructure for 1999, (2) cryogenic plant at Cd. PEMEX, (3) average annual growth of dry natural gas production for 1997-2004 is estimated at 5.2 per cent, (4) gas flows for December 1998, (5) PGPB- interconnect points, (6) U.S. Mexico gas trade for 1994-1998, (7) PGPB's interconnect projects with U.S., and (8) natural gas storage areas. Technological innovations in the industry include more efficient gas turbines which allow for cogeneration, heat recovery steam generators which reduce pollutant emissions by 21 per cent, cold boxes which increase heat transfer efficiency, and lateral reboilers which reduce energy consumption and total costs. A pie chart depicting natural gas demand by sector shows that natural gas for power generation will increase from 16 per cent in 1997 to 31 per cent in 2004. The opportunities for cogeneration projects were also reviewed. The Comision Federal de Electricidad and independent power producers represent the largest opportunity. The 1997-2001 investment program proposes an 85 per cent sulphur dioxide emission reduction compared to 1997 levels. This presentation also noted that during the 1998-2001 period, total ethane production will grow by 58 tbd. 31 figs

  18. Natural Hazards, Second Edition

    Science.gov (United States)

    Rouhban, Badaoui

    Natural disaster loss is on the rise, and the vulnerability of the human and physical environment to the violent forces of nature is increasing. In many parts of the world, disasters caused by natural hazards such as earthquakes, floods, landslides, drought, wildfires, intense windstorms, tsunami, and volcanic eruptions have caused the loss of human lives, injury, homelessness, and the destruction of economic and social infrastructure. Over the last few years, there has been an increase in the occurrence, severity, and intensity of disasters, culminating with the devastating tsunami of 26 December 2004 in South East Asia.Natural hazards are often unexpected or uncontrollable natural events of varying magnitude. Understanding their mechanisms and assessing their distribution in time and space are necessary for refining risk mitigation measures. This second edition of Natural Hazards, (following a first edition published in 1991 by Cambridge University Press), written by Edward Bryant, associate dean of science at Wollongong University, Australia, grapples with this crucial issue, aspects of hazard prediction, and other issues. The book presents a comprehensive analysis of different categories of hazards of climatic and geological origin.

  19. The system of nature

    CERN Document Server

    D'Holbac, Baron

    1999-01-01

    "The source of Man's unhappiness is his ignorance of Nature."D'Holbach believed that the misery he saw in mankind around him was caused by religion and its superstitious beliefs - that there was a God who controlled destiny and would reward or punish individuals. The System of Nature was written to replace these delusions with a schema of understanding based solely on the physical workings of nature. "Let Man study this nature, let him learn her laws, contemplate her energies." For d'Holbach the soul is only the physical body, understood from a certain point of view, which dies when the body dies. All the events and the nature of the world can be understood in terms of the motion and properties of matter; even the tiniest causes contribute to huge events - a simple change in the diet of an Emperor (or some other such insignificant cause), he suggests might have been capable of "saving kingdoms." For him, nature's laws are fixed and necessary, and if Man wants to find happiness it is best to accept this - if g...

  20. Textbook for nature entrepreneurship : product of the WURKS project Nature Entrepreneurship and Tourism within Green Education (NatureToGo)

    NARCIS (Netherlands)

    Felder, M.; Pellis, A.

    2013-01-01

    In recent years, government funding for nature conservation and development has declined. As a result, links between nature conservation and entrepreneurship are increasingly being made in both practice and education. This comes with many questions and challenges. In Green Secondary Vocational

  1. The "History" of Victorian Scientific Naturalism: Huxley, Spencer and the "End" of natural history.

    Science.gov (United States)

    Lightman, Bernard

    2016-08-01

    As part of their defence of evolutionary theory, T. H. Huxley and Herbert Spencer argued that natural history was no longer a legitimate scientific discipline. They outlined a secularized concept of life from biology to argue for the validity of naturalism. Despite their support for naturalism, they offered two different responses to the decline of natural history. Whereas Huxley emphasized the creation of a biological discipline, and all that that entailed, Spencer was more concerned with constructing an entire intellectual system based on the idea of evolution. In effect, Spencer wanted to create a new scientific worldview based on evolutionary theory. This had consequences for their understanding of human history, especially of how science had evolved through the ages. It affected their conceptions of human agency, contingency, and directionality in history. Examining Huxley's and Spencer's responses to the "end" of natural history reveals some of the deep divisions within scientific naturalism and the inherent problems of naturalism in general. Whereas Huxley chose to separate the natural and the historical, Spencer opted to fuse them into a single system. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

  2. Lesson "Balance in Nature

    Science.gov (United States)

    Chapanova, V.

    2012-04-01

    Lesson "Balance in Nature" This simulation game-lesson (Balance in Nature) gives an opportunity for the students to show creativity, work independently, and to create models and ideas. It creates future-oriented thought connected to their experience, allowing them to propose solutions for global problems and personal responsibility for their activities. The class is divided in two teams. Each team chooses questions. 1. Question: Pollution in the environment. 2. Question: Care for nature and climate. The teams work on the chosen tasks. They make drafts, notes and formulate their solutions on small pieces of paper, explaining the impact on nature and society. They express their points of view using many different opinions. This generates alternative thoughts and results in creative solutions. With the new knowledge and positive behaviour defined, everybody realizes that they can do something positive towards nature and climate problems and the importance of individuals for solving global problems is evident. Our main goal is to recover the ecological balance, and everybody explains his or her own well-grounded opinions. In this work process the students obtain knowledge, skills and more responsible behaviour. This process, based on his or her own experience, dialogue and teamwork, helps the participant's self-development. Making the model "human↔ nature" expresses how human activities impact the natural Earth and how these impacts in turn affect society. Taking personal responsibility, we can reduce global warming and help the Earth. By helping nature we help ourselves. Teacher: Veselina Boycheva-Chapanova " Saint Patriarch Evtimii" Scholl Str. "Ivan Vazov"-19 Plovdiv Bulgaria

  3. Técnica para redução do tônus e alongamento muscular passivo: efeitos na amplitude de movimento de crianças com paralisia cerebral espástica

    Directory of Open Access Journals (Sweden)

    Luana dos Santos de Oliveira

    2017-04-01

    Full Text Available Introdução: A paralisia cerebral (PC é resultante de lesão no encéfalo em fase de maturação, acarretando em disfunções motoras. A espasticidade, forma mais comum de acometimento, gera prejuízos funcionais intensificados pela diminuição da mobilidade. Objetivo: Analisar os efeitos do alongamento passivo lento do músculo tríceps sural e de técnica para diminuir o tônus do conceito Bobath na amplitude de movimento (ADM de dorsiflexão do tornozelo de crianças com PC espástica. Métodos: Participaram 18 crianças atendidas no Hospital Estadual Mario Covas de Santo André e na Santa Casa de Diadema. O grau da hipertonia do músculo tríceps sural foi determinado pela Escala de Aswhorth Modificada e a ADM de dorsiflexão foi medida pela goniometria. Esses dois procedimentos foram realizados antes e após as seguintes situações: 1 aplicação de um protocolo de alongamento muscular passivo; 2 protocolo com uma técnica para diminuir o tônus do conceito Bobath; e 3 emprego associado dos dois protocolos. Resultados: O grau de hipertonia não se modificou após o protocolo 1, porém os protocolos 2 e 3 diminuíram a espasticidade de maneira semelhante, conforme a Escala de Ashworth Modificada. Já o ângulo de dorsiflexão aumentou após aplicação dos três protocolos: 1 (p=0,176; 2 (p=0,008; e 3, com o aumento mais significativo (p=0,003. Conclusão: A técnica para redução do tônus mostrou efeito positivo na redução da espasticidade, segundo a Escala de Ashworth Modificada, e no aumento da ADM de crianças espásticas. A execução subsequente do alongamento muscular aumentou sua efetividade.

  4. Finland's leading natural gas company

    International Nuclear Information System (INIS)

    Anon.

    2000-01-01

    The ownership structure of Finland's leading natural gas company, Gasum, changed fundamentally in 1999, and the company is now no longer a subsidiary of Fortum Corporation. 'Our new strong and broad ownership base will enable us to develop the natural gas business and pipeline network in Finland in response to the requirements of our Finnish customers', says Antero Jaennes, Gasum's Chairman and CEO, who stresses that Gasum is committed to remaining the leading developer of the Finnish natural gas market and the number-one gas supplier. Natural gas usage in Finland in 1999 totalled 3.9 billion m 3 (38.7 TWh), unchanged from 1998. Natural gas accounted for 11% of Finland's total primary energy need, as it did in 1998. The proportion of natural gas used in district heating rose by 2% to 36%, and moved down 2% in power generation to 10%. Industry's use of natural gas fell 1% to 17%. 75% of natural gas was used in combined heat and power (CHP) generation in industry and district heating. In 2000, Gasum expects to sell 4 billion m 3 of natural gas (40 TWh)

  5. Natural - synthetic - artificial!

    DEFF Research Database (Denmark)

    Nielsen, Peter E

    2010-01-01

    The terms "natural," "synthetic" and "artificial" are discussed in relation to synthetic and artificial chromosomes and genomes, synthetic and artificial cells and artificial life.......The terms "natural," "synthetic" and "artificial" are discussed in relation to synthetic and artificial chromosomes and genomes, synthetic and artificial cells and artificial life....

  6. Provincialising Nature

    DEFF Research Database (Denmark)

    Provincialising Nature: Multidisciplinary Approaches to the Politics of the Environment in Latin America offers a timely analysis of some of the crucial challenges, contradictions and promises within current environmental discourses and practices in the region. This book shows both challenging...... scenarios and original perspectives that have emerged in Latin America in relation to the globally urgent issues of climate change and the environmental crisis. Two interconnected analytical frameworks guide the discussions in the book: the relationship between nature, knowledge and identity and their role...

  7. 75 FR 13524 - Northern Natural Gas Company, Southern Natural Gas Company, Florida Gas Transmission Company, LLC...

    Science.gov (United States)

    2010-03-22

    ... Natural Gas Company, Southern Natural Gas Company, Florida Gas Transmission Company, LLC, Transcontinental... notice that on March 5, 2010, Northern Natural Gas Company (Northern Natural), 1111 South 103rd Street, Omaha, Nebraska 68124- 1000, filed on behalf of itself and other owners, Southern Natural Gas Company...

  8. Colour agnosia impairs the recognition of natural but not of non-natural scenes.

    Science.gov (United States)

    Nijboer, Tanja C W; Van Der Smagt, Maarten J; Van Zandvoort, Martine J E; De Haan, Edward H F

    2007-03-01

    Scene recognition can be enhanced by appropriate colour information, yet the level of visual processing at which colour exerts its effects is still unclear. It has been suggested that colour supports low-level sensory processing, while others have claimed that colour information aids semantic categorization and recognition of objects and scenes. We investigated the effect of colour on scene recognition in a case of colour agnosia, M.A.H. In a scene identification task, participants had to name images of natural or non-natural scenes in six different formats. Irrespective of scene format, M.A.H. was much slower on the natural than on the non-natural scenes. As expected, neither M.A.H. nor control participants showed any difference in performance for the non-natural scenes. However, for the natural scenes, appropriate colour facilitated scene recognition in control participants (i.e., shorter reaction times), whereas M.A.H.'s performance did not differ across formats. Our data thus support the hypothesis that the effect of colour occurs at the level of learned associations.

  9. God, design, and naturalism: Implications of methodological naturalism in science for science-religion relation

    OpenAIRE

    Piotr Bylica; Dariusz Sagan

    2015-01-01

    The aim of this paper is to analyze the implications flowing from adopting methodological naturalism in science, with special emphasis on the relation between science and religion. Methodological naturalism, denying supernatural and teleological explanations, influences the content of scientific theories, and in practice leads to vision of science as compatible with ontological naturalism and in opposition to theism. Ontological naturalism in turn justifies the acceptance of methodological na...

  10. Natural gas for vehicles

    International Nuclear Information System (INIS)

    Prieur, A.

    2006-01-01

    Following a decade-long upsurge in the use of natural gas in the energy sector (heating and especially electricity), new outlets for natural gas are being developed in the transport sector. For countries endowed with substantial local resources, development in this sector can help reduce oil dependence. In addition, natural gas is often used to reduce pollution, particularly in cities

  11. Natural radioactivity in water supplies

    International Nuclear Information System (INIS)

    Horner, J.K.

    1985-01-01

    This book outlines the scientific aspects of the control of natural radioactivity in water supplies, as well as the labyrinthine uncertainties in water quality regulation concerning natural radiocontamination of water. The author provides an introduction to the theory of natural radioactivity; addresses risk assessment, sources of natural radiocontamination of water, radiobiology of natural radioactivity in water, and federal water law concerning natural radiocontamination. It presents an account of how one city dealt with the perplexes that mark the rapidly evolving area of water quality regulation. The contents include: radioactivity and risk; an introduction to the atomic theory; an introduction to natural radioactivity; risk assessment; uranium and radium contamination of water; radiobiology of uranium and radium in water. Determination of risk from exposure to uranium and radium in water; the legal milieu; one city's experience; and summary: the determinants of evolving regulation

  12. Comparative study of cerium (IV) sorptive properties in zeolite Y and clinoptilolite; Estudio comparativo de la fijacion de cerio (IV) en zeolitas, faujasita-Y y clinoptilolita

    Energy Technology Data Exchange (ETDEWEB)

    Garcia D, O C

    1994-12-31

    Among the problems of protecting the environment from radioactive contamination, the reduction of radioactive releases by improving monitoring, decontamination, and burial methods is one of the most important. Natural sorbents are gaining increased significance for solving this problem. Among these, zeolites deserve special attention since they have sufficient sorptive capacity, are highly radiation resistant, are widely distributed exhibit selectivity and are inexpensive. In the present work we determine experimentally the sorptive characteristics of clinoptilolite as a function of various factors and demonstrate that clinoptilolite is capable of sorbing Ce(IV) over a wide pH range. (Author).

  13. The Ecology of Hope: Natural Guides to Building a Children and Nature Movement

    Science.gov (United States)

    Charles, Cheryl

    2009-01-01

    Cheryl Charles, Ph.D gave the 2009 Paul F-Brandwein Lecture. The lecture addresses the impact of children's disconnect from the natural world in their everyday lives. Co-founder of the Children & Nature Network (C&NN) with Richard Louv, author of "Last Child in the Woods: Saving Our Children from Nature-Deficit Disorder" (2005/2008), the author…

  14. Diseño y validación de una tarea computarizada tipo Stroop para evaluar sesgos de la atención en bulimia nerviosa

    OpenAIRE

    Camacho-Ruíz, Esteban Jaime; Mancilla-Díaz, Juan Manuel; Escoto-Ponce De León, María Del Consuelo; Yáñez-Tellez, María Guillermina

    2009-01-01

    Objetivo: Desarrollar una tarea computarizada tipo Stroop para evaluar sesgos en la atención hacia palabras relacionadas con la comida y la figura, en pacientes con bulimia nerviosa. Se desarrollaron cuatro listas de palabras con valencia positiva y negativa, relacionadas con la comida y la figura corporal. Método: treinta y dos mujeres con bulimia nerviosa emparejadas con 32 mujeres sin trastorno, respondieron la versión original y una modificada de la Prueba de Stroop computarizada. Resulta...

  15. Diseño y Validación de una Tarea Computarizada Tipo Stroop para Evaluar Sesgos de la Atención en Bulimia Nerviosa

    OpenAIRE

    Esteban Jaime Camacho-Ruíz

    2009-01-01

    Objetivo: Desarrollar una tarea computarizada tipo Stroop para evaluar sesgos en la atención hacia palabras relacionadas con la comida y la figura, en pacientes con bulimia nerviosa. Se desarrollaron cuatro listas de palabras con valencia positiva y negativa, relacionadas con la comida y la figura corporal. Método: treinta y dos mujeres con bulimia nerviosa emparejadas con 32 mujeres sin trastorno, respondieron la versión original y una modificada de la Prueba de Stroop computarizada. Resulta...

  16. Principales causas de la morosidad en la jurisdicción laboral

    OpenAIRE

    Rafael Ospina Morales

    2006-01-01

    El proyecto desarrollado es de gran magnitud e importancia, toda vez que surgen cascadas de leyes que al poco tiempo de su vigencia, están siendo modificadas, adicionadas o derogadas, por quienes solucionan todos los problemas de Estado con sus administrados, expidiendo leyes, SINAVERIGUARLAS CAUSAS que han generado la patología social en determinado momento. La Ley debe tener en cuenta el fenómeno social, pero no a la ligera, sino profundizando sobre el origen y ...

  17. Medicación antigotosa para agresión refractaria en pacientes autistas

    OpenAIRE

    Ortiz Tobón, Juan Felipe

    2002-01-01

    Las conductas hetero y autoagresivas en pacientes con autismo pueden ser refractarias a los medicamentos comúnmente empleados; sin embargo, la adenosina, purina neuromoduladora, ha demostrado ser una sustancia con propiedades antiagresivas dentro de modelos animales. Las vías de purinas se encuentran modificadas en ciertas patologías que presentan automutilaciones. El alopurinol aumentaría de forma indirecta las concentraciones de adenosina, por lo cual sería efectiva en el manejo de la agres...

  18. What's nature got to do with it? A situated historical perspective on socio-natural commodities.

    Science.gov (United States)

    Peluso, Nancy Lee

    2012-01-01

    Nature(s) have been commodified since the early days of capitalism, but through processes and socio-natural relationships mediated by their times, histories and localities. While the conditions under which nature's commodities are being trademarked today may be new, their potential for commodification is not. Commodifications of nature should not come as a surprise to environmental social scientists and activists. In this article, I argue that commodification of ‘nature's products, places and processes’ produces new sorts of socio-natures. Situated histories of rubber are particularly relevant because, like carbon, ecosystem services and other recently commodified natures, rubber sits comfortably on the line between a fictitious commodity and a commodity produced explicitly for market: the latex alone has almost no use value, and to give it any exchange value, it requires processing. Yet analytically, it is still considered a ‘natural commodity’, different from ‘synthetic rubber’ and other tradable tree latexes in qualities and socio-natural characteristics. However, it is the social relations constituting rubber's production and trade in various rainforest and agro-forestry environments that have given it a positive or negative connotation, rather than its natural properties or the ecological contexts within which it has been produced. By situating rubber in three of its globally important temporal and spatial contexts, I show how it has been subjected to fairy-tale-like stories that masked and naturalized its commodity lives of the moment. Understanding how history is told or remains untold is thus an essential part of the politics of knowledge production, but also of human experience and mobilization for change. It should be part of any political ecology analysis.

  19. Natural gas prices

    International Nuclear Information System (INIS)

    Johnson, W.A.

    1990-01-01

    Since the 1970s, many electric utilities and industrial boiler fuel users have invested in dual fuel use capability which has allowed them to choose between natural gas, residual fuel oil, and in some instances, coal as boiler fuels. The immediate reason for this investment was the need for security of supply. Wellhead regulation of natural gas prices had resulted in shortages during the 1970s. Because many industrial users were given lowest priority in pipeline curtailments, these shortages affected most severely boiler fuel consumption of natural gas. In addition, foreign supply disruptions during the 1970s called into question the ready availability of oil. Many boiler fuel users of oil responded by increasing their ability to diversify to other sources of energy. Even though widespread investment in dual fuel use capability by boiler fuel users was initially motivated by a need for security of supply, perhaps the most important consequence of this investment was greater substitutability between natural gas and resid and a more competitive boiler fuel market. By the early 1980s, most boiler fuel users were able to switch from one fuel to another and often did for savings measured in pennies per MMBtu. Boiler fuel consumption became the marginal use of both natural gas and resid, with coal a looming threat on the horizon to both fuels

  20. Natural Resource Management Plan

    Energy Technology Data Exchange (ETDEWEB)

    Green, T. [Brookhaven National Laboratory (BNL), Upton, NY (United States); Schwager, K. [Brookhaven National Laboratory (BNL), Upton, NY (United States)

    2016-10-01

    This comprehensive Natural Resource Management Plan (NRMP) for Brookhaven National Laboratory (BNL) was built on the successful foundation of the Wildlife Management Plan for BNL, which it replaces. This update to the 2003 plan continues to build on successes and efforts to better understand the ecosystems and natural resources found on the BNL site. The plan establishes the basis for managing the varied natural resources located on the 5,265-acre BNL site, setting goals and actions to achieve those goals. The planning of this document is based on the knowledge and expertise gained over the past 15 years by the Natural Resources management staff at BNL in concert with local natural resource agencies including the New York State Department of Environmental Conservation, Long Island Pine Barrens Joint Planning and Policy Commission, The Nature Conservancy, and others. The development of this plan works toward sound ecological management that not only benefits BNL’s ecosystems but also benefits the greater Pine Barrens habitats in which BNL is situated. This plan applies equally to the Upton Ecological and Research Reserve (Upton Reserve). Any difference in management between the larger BNL area and the Upton Reserve are noted in the text.

  1. Market prospective of natural gas 2010-2025; Prospectiva del mercado de gas natural 2010-2025

    Energy Technology Data Exchange (ETDEWEB)

    Diaz Bautista, Alejandro; Doniz Gonzalez, Virginia; Navarrete Barbosa, Juan Ignacio [Secretaria de Energia, Mexico, D.F. (Mexico)

    2010-07-01

    The Ministry of Energy, in compliance to Article 109 of the Natural Gas Regulations, publishes the Prospective natural gas market 2010-2025, which contains the most current information about the historical evolution and growth prospects of the domestic market country's natural gas and its role in the international context. This foresight is attached to the lines of action established in the National Energy Strategy, ratified by Congress in April 2010 in regard to strengthening the transportation infrastructure of natural gas, in order to ensure the supply of this fuel, therefore remains congruence with the instruments of power sector planning. The first one concerns the international panorama of natural gas in the different producing and consuming regions around the world. Chapter two provides a current perspective of those actions in the sector within the regulatory framework for natural gas in Mexico. The third chapter details the issues that occurred in the natural gas market during the period 1999-2009 and the fourth chapter discusses the expected evolution of demand and domestic supply of natural gas by 2025. [Spanish] La Secretaria de Energia, en el cumplimiento al Articulo 109 del Reglamento de Gas Natural, publica la Prospectiva del mercado de gas natural 2010-2025, la cual contiene la informacion mas actualizada acerca de la evolucion historica y las expectativas de crecimiento del mercado interno de gas natural del pais y su papel en el contexto internacional. Esta Prospectiva se apega a las lineas de accion establecidas en la Estrategia Nacional de Energia, ratificada por el Congreso en abril de 2010, en lo relativo a fortalecer la infraestructura de transporte de gas natural, con el fin de asegurar el suministro de este combustible, por lo cual se mantiene congruencia con los instrumentos de planeacion del sector energetico. La Prospectiva esta integrada por cuatro capitulos. El primero se refiere al panorama internacional del gas natural en las

  2. English Nature's ''natural areas'': a different look at the countryside

    International Nuclear Information System (INIS)

    Kirby, K.J.

    1994-01-01

    Nature conservation is often equated with the protection of nature reserves and other special sites. However in England such sites are now often surrounded by agricultural land of limited wildlife value. There is no guarantee that the plants and animal communities that we have inherited can be maintained in island-like patches. Therefore we must try to make the countryside in-between richer as well. The current changing agricultural and forestry scenes mean that there is a good possibility that this can be achieved. Short rotation coppice (SRC) is one of the new land-uses whose impact we need to consider. Studies to date indicate that it is a richer habitat than arable land or heavily improved grassland at the level of the individual field. Our concern in the countryside as a whole however is how blocks of SRC relate to other habitats and features; are there better alternative uses (from a wildlife point of view) in a particular landscape? The description of the current state and long-term objectives for particular Natural Areas should help us to make such decisions in a consistent way. Use of wood for fuel from traditional coppice is also likely to benefit nature conservation by bringing neglected woods back into rotation. Where large schemes are proposed however there are a number of issues related primarily to the timing of the work and methods of harvesting that may need adjustment to prevent damage to sensitive sites. Involvement of English Nature staff at an early stage should make it easier to resolve any potential problems. (Author)

  3. Natural gas monthly, August 1995

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-08-24

    The Natural Gas Monthly (NGM) highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. From time to time, the NGM features articles designed to assist readers in using and interpreting natural gas information. This month`s feature article is on US Natural Gas Imports and Exports 1994.

  4. Natural gas monthly, May 1997

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-05-01

    The Natural Gas Monthly highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. From time to time, the NGM features articles designed to assist readers in using and interpreting natural gas information. The feature article this month is ``Restructuring energy industries: Lessons from natural gas.`` 6 figs., 26 tabs.

  5. A mathematical nature walk

    CERN Document Server

    Adam, John A

    2009-01-01

    How heavy is that cloud? Why can you see farther in rain than in fog? Why are the droplets on that spider web spaced apart so evenly? If you have ever asked questions like these while outdoors, and wondered how you might figure out the answers, this is a book for you. An entertaining and informative collection of fascinating puzzles from the natural world around us, A Mathematical Nature Walk will delight anyone who loves nature or math or both. John Adam presents ninety-six questions about many common natural phenomena--and a few uncommon ones--and then shows how to answer them using mostly b

  6. Natural aerodynamics

    CERN Document Server

    Scorer, R S

    1958-01-01

    Natural Aerodynamics focuses on the mathematics of any problem in air motion.This book discusses the general form of the law of fluid motion, relationship between pressure and wind, production of vortex filaments, and conduction of vorticity by viscosity. The flow at moderate Reynolds numbers, turbulence in a stably stratified fluid, natural exploitation of atmospheric thermals, and plumes in turbulent crosswinds are also elaborated. This text likewise considers the waves produced by thermals, transformation of thin layer clouds, method of small perturbations, and dangers of extra-polation.Thi

  7. Modeling Natural Selection

    Science.gov (United States)

    Bogiages, Christopher A.; Lotter, Christine

    2011-01-01

    In their research, scientists generate, test, and modify scientific models. These models can be shared with others and demonstrate a scientist's understanding of how the natural world works. Similarly, students can generate and modify models to gain a better understanding of the content, process, and nature of science (Kenyon, Schwarz, and Hug…

  8. Short-term outlook for natural gas and natural gas liquids to 2006 : an energy market assessment

    International Nuclear Information System (INIS)

    2005-10-01

    In recent years, natural gas markets in North America have seen a close balance between supply and demand, resulting in high and volatile natural gas prices. The National Energy Board monitors the supply of all energy commodities in Canada along with the demand for Canadian energy commodities in domestic and export markets. This is the NEB's first energy market assessment report that presents a combined short-term analysis and outlook of natural gas and natural gas liquids (NGLs), such as ethane, propane and butane. It provides comprehensive information on the complexity of natural gas and NGL industries and highlights recent developments and topical issues. As a major producer of natural gas, western Canada has a correspondingly large natural gas processing capability that was developed specifically to extract NGLs. A world-scale petrochemical industry was developed in Alberta to convert NGLs into even higher valued products such as ethylene. Since NGLs in Canada are sourced mostly from natural gas, changes to the supply and demand for natural gas would impact NGL supply. This report addressed the issue of commodity prices with reference to crude oil, natural gas and NGL prices. Natural gas supply in terms of North American production and natural gas from coal (NGC) was also reviewed along with natural gas demand for residential and commercial heating, industrial use, power generation, and enhanced recovery for oil sand operations. There are about 692 gas plants in Canada that process raw natural gas into marketable gas and NGLs. Most are small field plants that process raw natural gas production to remove impurities such as sulphur, water and other contaminants. This report also discussed this infrastructure, with reference to field plants, straddle plants, pipelines, distribution and storage, including underground NGL storage. 3 tabs., 27 figs., 5 appendices

  9. Natural gas monthly, June 1994

    Energy Technology Data Exchange (ETDEWEB)

    1994-06-01

    The Natural Gas Monthly (NGM) highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. From time to time, the NGM features articles designed to assist readers in using and interpreting natural gas information. The feature article this month is the executive summary from Natural Gas 1994: Issues and Trends. 6 figs., 31 tabs.

  10. "Diseases and natural kinds".

    Science.gov (United States)

    Sulmasy, Daniel P

    2005-01-01

    David Thomasma called for the development of a medical ethics based squarely on the philosophy of medicine. He recognized, however, that widespread anti-essentialism presented a significant barrier to such an approach. The aim of this article is to introduce a theory that challenges these anti-essentialist objections. The notion of natural kinds presents a modest form of essentialism that can serve as the basis for a foundationalist philosophy of medicine. The notion of a natural kind is neither static nor reductionistic. Disease can be understood as making necessary reference to living natural kinds without invoking the claim that diseases themselves are natural kinds. The idea that natural kinds have a natural disposition to flourish as the kinds of things that they are provides a telos to which to tether the notion of disease - an objective telos that is broader than mere survival and narrower than subjective choice. It is argued that while nosology is descriptive and may have therapeutic implications, disease classification is fundamentally explanatory. Sickness and illness, while referring to the same state of affairs, can be distinguished from disease phenomenologically. Scientific and diagnostic fallibility in making judgments about diseases do not diminish the objectivity of this notion of disease. Diseases are things, not kinds. Injury is a concept parallel to disease that also makes necessary reference to living natural kinds. These ideas provide a new possibility for the development of a philosophy of medicine with implications for medical ethics.

  11. Almacenamiento de gas natural

    Directory of Open Access Journals (Sweden)

    Tomás Correa

    2008-12-01

    Full Text Available The largest reserves of natural gas worldwide are found in regions far of main cities, being necessary different alternatives to transport the fluid to the consumption cities, such as pipelines, CNG or ships, LNG, depending on distances between producing regions and demanding regions and the producing volumes. Consumption regions have three different markets to naturalgas; residential and commercial, industrial and power generation sector. The residential and commercial is highly seasonal and power generation sector is quite variable depending on increases of temperature during summer time. There are also external issuesthat affect the normal gas flow such as fails on the national system or unexpected interruptions on it, what imply that companies which distribute natural gas should design plans that allow supplying the requirements above mentioned. One plan is using underground natural gas storage with capacities and deliverability rates enough to supply demands. In Colombia there are no laws in this sense but it could be an exploration to discuss different ways to store gas either way as underground natural gas storage or above superficies. Existing basically three different types of underground natural gas storage; depleted reservoirs, salt caverns and aquifers. All ofthem are adequate according to geological characteristics and the needs of the distributors companies of natural gas. This paper is anexploration of technical and economical characteristics of different kind of storages used to store natural gas worldwide.

  12. Naturalness and image quality : saturation and lightness variation in color images of natural scenes

    NARCIS (Netherlands)

    Ridder, de H.

    1996-01-01

    The relation between perceived image quality and naturalness was investigated by varying the colorfulness of natural images at various lightness levels. At each lightness level, subjects assessed perceived colorfulness, naturalness, and quality as a function of average saturation by means of direct

  13. The Unnatural Nature of Nature and Nurture: Questioning the Romantic Heritage

    Science.gov (United States)

    Stables, Andrew

    2009-01-01

    From a cultural-historical perspective, nature and nurture (and thus education) are contested concepts. The paper focuses on the nature/nurture debate in the work of William Shakespeare (influenced by Montaigne) and in the Romantic tradition (evidenced by Rousseau and Wordsworth), and argues that while our Romantic inheritance (still highly…

  14. Kant on the history of nature: the ambiguous heritage of the critical philosophy for natural history.

    Science.gov (United States)

    Sloan, Phillip R

    2006-12-01

    This paper seeks to show Kant's importance for the formal distinction between descriptive natural history and a developmental history of nature that entered natural history discussions in the late eighteenth century. It is argued that he developed this distinction initially upon Buffon's distinctions of 'abstract' and 'physical' truths, and applied these initially in his distinction of 'varieties' from 'races' in anthropology. In the 1770s, Kant appears to have given theoretical preference to the 'history' of nature [Naturgeschichte] over 'description' of nature [Naturbeschreibung]. Following Kant's confrontations with Johann Herder and Georg Forster in the late 1780s, Kant weakened the epistemic status of the 'history of nature' and gave theoretical preference to 'description of nature'. As a result, Kant's successors, such as Goethe, could draw from Kant either a justification for a developmental history of nature, or, as this paper argues, a warrant from the critical philosophy for denying the validity of the developmental history of nature as anything more than a 'regulative' idea of reason.

  15. Natural photonic crystals

    Energy Technology Data Exchange (ETDEWEB)

    Vigneron, Jean Pol, E-mail: jean-pol.vigneron@fundp.ac.be [Research Center in Physics of Matter and Radiation (PMR), University of Namur (FUNDP), rue de Bruxelles, 61, B-5000 Namur (Belgium); Simonis, Priscilla [Research Center in Physics of Matter and Radiation (PMR), University of Namur (FUNDP), rue de Bruxelles, 61, B-5000 Namur (Belgium)

    2012-10-15

    Photonic structures appeared in nature several hundred millions years ago. In the living world, color is used for communication and this important function strongly impacts the individual chances of survival as well as the chances to reproduce. This has a statistical influence on species populations. Therefore, because they are involved in evolution, natural color-generating structures are - from some point of view - highly optimized. In this short review, a survey is presented of the development of natural photonic crystal-type structures occurring in insects, spiders, birds, fishes and other marine animals, in plants and more, from the standpoint of light-waves propagation. One-, two-, and three-dimensional structures will be reviewed with selected examples.

  16. Natural photonic crystals

    International Nuclear Information System (INIS)

    Vigneron, Jean Pol; Simonis, Priscilla

    2012-01-01

    Photonic structures appeared in nature several hundred millions years ago. In the living world, color is used for communication and this important function strongly impacts the individual chances of survival as well as the chances to reproduce. This has a statistical influence on species populations. Therefore, because they are involved in evolution, natural color-generating structures are - from some point of view - highly optimized. In this short review, a survey is presented of the development of natural photonic crystal-type structures occurring in insects, spiders, birds, fishes and other marine animals, in plants and more, from the standpoint of light-waves propagation. One-, two-, and three-dimensional structures will be reviewed with selected examples.

  17. Natural and technologic hazardous material releases during and after natural disasters: a review.

    Science.gov (United States)

    Young, Stacy; Balluz, Lina; Malilay, Josephine

    2004-04-25

    Natural disasters may be powerful and prominent mechanisms of direct and indirect hazardous material (hazmat) releases. Hazardous materials that are released as the result of a technologic malfunction precipitated by a natural event are referred to as natural-technologic or na-tech events. Na-tech events pose unique environmental and human hazards. Disaster-associated hazardous material releases are of concern, given increases in population density and accelerating industrial development in areas subject to natural disasters. These trends increase the probability of catastrophic future disasters and the potential for mass human exposure to hazardous materials released during disasters. This systematic review summarizes direct and indirect disaster-associated releases, as well as environmental contamination and adverse human health effects that have resulted from natural disaster-related hazmat incidents. Thorough examination of historic disaster-related hazmat releases can be used to identify future threats and improve mitigation and prevention efforts.

  18. Natural Information Processing Systems

    OpenAIRE

    John Sweller; Susan Sweller

    2006-01-01

    Natural information processing systems such as biological evolution and human cognition organize information used to govern the activities of natural entities. When dealing with biologically secondary information, these systems can be specified by five common principles that we propose underlie natural information processing systems. The principles equate: (1) human long-term memory with a genome; (2) learning from other humans with biological reproduction; (3) problem solving through random ...

  19. An Overview of Some Natural Products with Two A-Level Science Club Natural Products Experiments

    Science.gov (United States)

    Sosabowski, Michael Hal; Olivier, George W. J.; Jawad, Hala; Maatta, Sieja

    2017-01-01

    Natural products are ubiquitous in nature but do not form a large proportion of the A-level syllabuses in the UK. In this article we briefly discuss a small selection of natural products, focusing on alcohols, aldehydes and ketones, and alkaloids. We then outline two natural product experiments that are suitable for A-level chemistry clubs or…

  20. Orlice Nature Park - environmental themes

    International Nuclear Information System (INIS)

    Hanus, L.

    2002-01-01

    The aim of this abstract is to outline the main characteristics of Orlice Nature Park and of the procedure of Environmental Impact Assessment (EIA), and to evaluate public interest in the nature park and in nature protection in general. Orlice Nature Park was instituted in 1996. The function of the park is to protect the character of the area of landscape around the River Orlice. Orlice Natural Park covers an area of 115 sq. km. The main environmental risks to the park are: intensive agriculture, forest mono-culture, industry, transport, channel improvement, the building of holiday cottages, sport, and recreation. Among the conflicts of interest in the park are: nature protection, water management, building constrictions, business, fishery, water sports and recreation. During the process of Environmental Impact Assessment in Hradec Kralove, the public voiced its opinion against the building of a supermarket within the grounds of of the nature park. In this case the public showed its interest in the value of nature and landscape, the value of human health and the value of plant species. In general, the public and the local media show an interest in the park only in exceptional circumstances. (author)

  1. Nature Foil Reliefs

    Science.gov (United States)

    Lane, Shaw J.

    2012-01-01

    Nature has always been a source of inspiration for artists across the centuries. Artists such as Leonardo da Vinci, Georgia O'Keeffe, Ansel Adams, and Andy Goldsworthy all drew inspiration for their work from nature. Seeds come from the dried pods, which when planted and cared for, bear fruit. In this article, the author describes how her…

  2. European natural gas

    International Nuclear Information System (INIS)

    Thackeray, Fred

    1999-11-01

    Contains Executive Summary and Chapters on: Main issues; Natural gas consumption and supply: statistics and key features of individual countries; Sectoral natural gas consumption; Indigenous production; Imports; Prices and taxes; The spot market: The interconnector; Forecasts of production and consumption and contracted imports; Progress of markets liberalisation; Effects of environmentalist developments; Transmission networks and storage; Some principal players. (Author)

  3. Atmosfera modificada e controle de etileno para bananas 'Prata-Anã' cultivadas na Amazônia Setentrional Brasileira Atmospheric modification and ethylene's control in posthaverst, for 'Prata-Anã' bananas cultivated in the Setentrional Brazilian Amazon

    Directory of Open Access Journals (Sweden)

    Marcos André de Souza Prill

    2012-12-01

    Full Text Available O presente trabalho teve por objetivo avaliar o efeito da atmosfera modificada (AM pelo uso de embalagem plástica de polietileno de baixa densidade (PEBD, do vácuo e da adsorção de etileno, visando à manutenção da qualidade das bananas 'Prata-Anã' produzidas em Roraima. As análises foram realizadas em intervalos de 5 dias após a colheita, até 35 dias de armazenamento refrigerado (AR. Verificou-se que os frutos submetidos a embalagem de PEBD apresentaram as menores perdas de massa fresca quando comparados aos demais. Da mesma forma, os frutos embalados na presença do adsorvedor de etileno obtiveram a melhor manutenção na coloração da casca, atraso temporal, do pico climatérico, assim como o retardamento na degradação do amido, os menores incrementos de sólidos solúveis e acidez titulável, as menores concentrações de etileno nos interiores das embalagens e atraso temporal e a diminuição da atividade enzimática. Isso, possivelmente, proporcionou os maiores teores de pectina total e solúvel ao final do período experimental. A combinação do uso da embalagem de PEBD com o sachê de permanganato de potássio (KMnO4 resultou no retardamento do processo de maturação dos frutos de banana 'Prata-Anã', quando armazenada a 12 ºC. Pode-se atribuir esse efeito benéfico à presença do sachê na adsorção de etileno e, consequentemente, na ação do etileno no amadurecimento dos frutos, retardando a senescência das bananas 'Prata-Anã'.This present study aimed to evaluate the effect of modified atmosphere (MA by the use of plastic packaging for low density polyethylene (LDPE, the vacuum and the adsorption of ethylene, aiming the maintenance of the quality of bananas 'Prata Anã' cultived in Roraima.. Analyses were performed each 5 days after harvest, up to 35 days. It was verified that the fruit under LDPE bags showed the lowest losses of fresh weight when compared to the others. Likewise, as the fruits packed in the

  4. The Science of Middle Nature

    Science.gov (United States)

    Pataki, D. E.; Pincetl, S.

    2012-12-01

    In the field of biogeochemistry, urbanization is often considered as an "alteration" or "disturbance" to the earth's surface and its natural processes. This view is an outcome of the view of nature inherent in earth system science and ecology, in which nature is defined as separate from humans and society. However, other disciplines are based in alternative views of nature in which humans are more integral components of the landscape. Urban planning, landscape architecture, agriculture, and horticulture, for example, more fully integrate the role of landscape design and management in the functioning of human-dominated ecosystems. We suggest that the field of urban biogeochemistry has been somewhat limited by the predominant, disturbance-based view of the role of nature in cities, and that more deeply evaluating and broadening the concept of nature inherent in studies of urban processes can enhance our understanding of the role of urbanization in the earth system. A particularly useful concept is the "middle nature" proposed by Cosgrove (1993), which serves a purpose of "actively transforming nature into culture." It is this view of urban landscapes as middle nature, or transformation of urban space into human-dominated nature with a purpose, that is lacking from the current scientific discourse about the role of biogeochemistry in urban ecosystem services. A scientific evaluation of middle nature implies studying the performance of urban designs to meet intended cultural and environmental goals, including beauty, social equity, governance, and social capital as well as environmental quality. We describe our work in evaluating the transformed urban landscapes of Los Angeles from multiple perspectives that focus on urban livability, equity, and beauty as well as the physical impacts of plants and soils on the environment. The outcomes of this process do not necessary meet the traditional demands of biophysical ecology such as utilizing native species, maximizing

  5. Natural gas monthly, August 1993

    Energy Technology Data Exchange (ETDEWEB)

    1993-08-25

    The Natural Gas Monthly (NGM) is prepared in the Data Operations Branch of the Reserves and Natural Gas Division, Office of Oil and Gas, Energy Information Administration (EIA), US Department of Energy (DOE). The NGM highhghts activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. From time to time, the NGM features articles designed to assist readers in using and interpreting natural gas information.

  6. Natural Products and HIV/AIDS.

    Science.gov (United States)

    Cary, Daniele C; Peterlin, B Matija

    2018-01-01

    The study of natural products in biomedical research is not a modern concept. Many of the most successful medical therapeutics are derived from natural products, including those studied in the field of HIV/AIDS. Biomedical research has a rich history of discovery based on screens of medicinal herbs and traditional medicine practices. Compounds derived from natural products, which repress HIV and those that activate latent HIV, have been reported. It is important to remember the tradition in medical research to derive therapies based on these natural products and to overcome the negative perception of natural products as an "alternative medicine."

  7. Natural gas marketing and transportation

    International Nuclear Information System (INIS)

    Anon.

    1991-01-01

    This book covers: Overview of the natural gas industry; Federal regulation of marketing and transportation; State regulation of transportation; Fundamentals of gas marketing contracts; Gas marketing options and strategies; End user agreements; Transportation on interstate pipelines; Administration of natural gas contracts; Structuring transactions with the nonconventional source fuels credit; Take-or-pay wars- a cautionary analysis for the future; Antitrust pitfalls in the natural gas industry; Producer imbalances; Natural gas futures for the complete novice; State non-utility regulation of production, transportation and marketing; Natural gas processing agreements and Disproportionate sales, gas balancing, and accounting to royalty owners

  8. 75 FR 42432 - Northern Natural Gas Company, Southern Natural Gas Company, Florida Gas Transmission Company, LLC...

    Science.gov (United States)

    2010-07-21

    ... Natural Gas Company, Southern Natural Gas Company, Florida Gas Transmission Company, LLC, Transcontinental... abandonment of facilities by Northern Natural Gas Company, Southern Natural Gas Company, Florida Gas... resources, fisheries, and wetlands; Cultural resources; Vegetation and wildlife; Endangered and threatened...

  9. Virginia Natural Heritage Program

    Science.gov (United States)

    Heritage About Natural Heritage Overview, Mission Natural Heritage Inventory Community Ecology Program ) | Strategic Plan (PDF) | Executive Progress Report (PDF) | Code of Ethics (PDF) Your browser does not support

  10. Rethinking of the criteria for natural analogue study. A case of Tono natural analogue study

    International Nuclear Information System (INIS)

    Yoshida, Hidekazu

    1996-01-01

    Natural analogue regarding long-term performance of the geological disposal system for radioactive waste isolation is essentially the study of geochemical process which has been evolved in geological environment. All geochemical studies, however, will not be nominated as natural analogue studies. It is, therefore, important to be clear the criteria for natural analogue study with the view of analogy by following three categories, (1) Conceptual model development, (2) Data provision and (3) Model testing, for the concept of geological disposal and safety assessment model. Rethinking of the criteria for natural analogue study through the case of Tono Natural Analogue Study, and the usefulness of natural analogue study for the safety assessment of geological disposal system in Japan have been presented in this paper. (author)

  11. Natural Gas Multi-Year Program Plan

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-12-01

    This document comprises the Department of Energy (DOE) Natural Gas Multi-Year Program Plan, and is a follow-up to the `Natural Gas Strategic Plan and Program Crosscut Plans,` dated July 1995. DOE`s natural gas programs are aimed at simultaneously meeting our national energy needs, reducing oil imports, protecting our environment, and improving our economy. The Natural Gas Multi-Year Program Plan represents a Department-wide effort on expanded development and use of natural gas and defines Federal government and US industry roles in partnering to accomplish defined strategic goals. The four overarching goals of the Natural Gas Program are to: (1) foster development of advanced natural gas technologies, (2) encourage adoption of advanced natural gas technologies in new and existing markets, (3) support removal of policy impediments to natural gas use in new and existing markets, and (4) foster technologies and policies to maximize environmental benefits of natural gas use.

  12. STUDIES ON NATURAL WEATHERING OF RATTAN POWDER-FILLED NATURAL RUBBER COMPOSITES

    Directory of Open Access Journals (Sweden)

    Komethi Muniandy,

    2012-07-01

    Full Text Available This article investigates the effect of natural weathering on mechanical and morphological properties of rattan powder-filled natural rubber (NR composites as a function of filler loading and silane coupling agent. The rattan powder samples in the range of 0 to 30 phr were compounded with NR using a laboratory size two-roll mill. The natural weathering test was carried out for six months. The degradation of the samples was evaluated by performing a tensile test, a Fourier transform infrared spectroscopy (FTIR, and a scanning electron microscopy (SEM test. The results indicated that after natural weathering, an increase in stress at 100% elongation (M100 can be seen for samples without the silane coupling agent, whilst M100 was reduced for samples with silane coupling agent. A drastic reduction in tensile strength and elongation at break were observed for all samples due to the photo-oxidation process that occurred during the degradation of the samples. The extent of degradation on the samples’ surfaces and the presence of oxygenated products were confirmed by SEM and FTIR studies, respectively.

  13. Human-Nature for Climate Action: Nature-Based Solutions for Urban Sustainability

    Directory of Open Access Journals (Sweden)

    Helen Santiago Fink

    2016-03-01

    Full Text Available The global climate change agenda proceeds at an incremental pace while the Earth is approaching critical tipping points in its development trajectory. Climate action at this pinnacle juncture needs to be greatly accelerated and rooted in the fundamentals of the problem—human beings’ disconnection from nature. This paper underscores the valuable role nature and nature-based solutions can play in addressing climate change at the city scale and its implications for broader sustainability. Urban ecosystems (nature in cities are seen as an integral part of a proposed local climate action rubric wherein policy measures and integrated planning guide lowcarbon/impact development to create more resilient and sustainable urban environments. The use of green infrastructure is highlighted as a cost-effective means to contribute to mitigation and adaptation needs as well as to promote human wellbeing. The paper takes an exploratory view of the influence of ecosystem services, particularly cultural services, and its economics in relation to the individual and society to understand how biophilia can be nurtured to promote environmental stewardship and climate action.

  14. Technology, society and nature. Technik, Gesellschaft und Natur

    Energy Technology Data Exchange (ETDEWEB)

    Kraemer, S

    1982-01-01

    This paper intends to counter with a demand for systematics the boom of ecological oriented criticism passed on technical science and engineering and on the fact that individual sciences make a subject of engineering. It deals with the theoretical foundations of relationships between technology, society and nature. An interdisciplinary approach attempts to do justice to the multi-dimensionality of engineering and ''technology''. This approach includes the formulation of questions and the findings of social sciences, philosophy, and technology. The object is to determine technology as a form of social practice - a practice which includes the vital adjustment of man to his natural environment as well as the organisation of his social behaviour.

  15. Natural Weathering Exposure Station

    Data.gov (United States)

    Federal Laboratory Consortium — The Corps of Engineers' Treat Island Natural Weathering Exposure Station is a long-term natural weathering facility used to study concrete durability. Located on the...

  16. Alternative Fuels Data Center: Natural Gas

    Science.gov (United States)

    Natural Gas Printable Version Share this resource Send a link to Alternative Fuels Data Center : Natural Gas to someone by E-mail Share Alternative Fuels Data Center: Natural Gas on Facebook Tweet about Alternative Fuels Data Center: Natural Gas on Twitter Bookmark Alternative Fuels Data Center: Natural Gas on

  17. Natural gas monthly, August 1994

    Energy Technology Data Exchange (ETDEWEB)

    1994-08-24

    The Natural Gas Monthly (NGM) highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. From time to time, the NGM features articles designed to assist readers in using and interpreting natural gas information.

  18. Natural gas monthly, November 1993

    International Nuclear Information System (INIS)

    1993-01-01

    The Natural Gas Monthly (NGM) highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground state data are also reported. From time to time, the NGM features articles designed to assist readers in using and interpreting natural gas information

  19. Is device-modified trabeculectomy better than classic surgery for treatment of glaucoma?

    Directory of Open Access Journals (Sweden)

    Eduardo Pimente

    2017-08-01

    Full Text Available Resumen En los últimos años, diversas técnicas han surgido como complemento o reemplazo para la trabeculectomía, cirugía estándar en el manejo del glaucoma. La trabeculectomía modificada con dispositivo es una técnica reciente cuyos resultados en comparación con la técnica clásica aún no han sido del todo definidos. Para responder esta pregunta utilizamos Epistemonikos, la mayor base de datos de revisiones sistemáticas en salud, la cual es mantenida mediante búsquedas en múltiples fuentes de información, incluyendo MEDLINE, EMBASE, Cochrane, entre otras. Identificamos ocho revisiones sistemáticas que en conjunto incluyen 34 estudios aleatorizados. Extrajimos los datos desde las revisiones identificadas, reanalizamos los datos de los estudios primarios, realizamos un metanálisis y preparamos tablas de resumen de los resultados utilizando el método GRADE. Concluimos que la trabeculectomía modificada con dispositivo probablemente se asocia a un mayor éxito completo y que podría disminuir la presión intraocular más que la cirugía clásica. Además, está técnica probablemente tendría un mejor perfil de seguridad que la terapia estándar.

  20. Avaliação de diferentes tipos de atmosferas modificadas na vida útil de carambolas minimamente processadas Evaluation of different types of modified atmosphere in cold storage of star fruits minimally processed

    Directory of Open Access Journals (Sweden)

    Leandro Camargo Neves

    2006-12-01

    Full Text Available Este trabalho teve por objetivo a avaliação da vida útil potencial de carambolas cv. Golden Star, minimamente processadas, armazenadas em diferentes tipos de embalagens plásticas, para a concepção da atmosfera modificada. Os frutos colhidos fisiologicamente maturos apresentaram coloração verde-amarelada, sólidos solúveis (SS médios de 6,8 ºBrix e massa média de 185 g. Antes da aplicação dos tratamentos, os frutos foram selecionados, higienizados em solução de hipoclorito de sódio (NaOCl a 100 mg. L-1, resfriados por 12 horas a 15 ± 0,5 °C, seccionados transversalmente, sendo então novamente higienizados em solução de NaOCl a 10 mg.L-1, por 3 minutos. Em seguida, os pedaços em forma de estrelas foram acondicionados em bandejas rígidas de poliestireno, com capacidade para 250 g, e revestidas com os seguintes materiais: T1: filme plástico perfurado de polietileno de baixa densidade (PEBD, de 0,006 mm; T2: filme plástico poliolefínico com antiembassamento da Dupont® (AGF, de 0,015 mm; T3: filme plástico poliolefínico da Dupont® (HF, de 0,015 mm; T4: filme plástico de PEBD, de 60 µm; T5: filme plástico de PEBD, de 80 µm; T6: filme plástico de polipropileno (PP, de 22 µm, e T7: bandeja rígida de polietileno tereftalato (PET, com capacidade para 500 mL, com tampa do mesmo material. As embalagens foram então armazenadas em câmara frigorífica a 12 ± 0,5 °C e 90 ± 3% de U.R, por 18 dias. Observou-se que não houve diferença significativa quanto aos sólidos solúveis (SS e acidez titulável (AT. O maior número de microrganismos e valor de pH foram observados nos frutos embalados nos filmes plásticos de PEBD de 0,006 mm, AGF e HF de 0,015 mm da Dupont®. Entretanto, os frutos acondicionados nas embalagens PET apresentaram o maior teor de ácido ascórbico. Da mesma forma, somente nas embalagens PET é que se conseguiu modificação atmosférica eficiente do ponto de vista da manutenção dos atributos de

  1. Education in the imbalance of Nature

    Science.gov (United States)

    Shlafman, L. M.; Kontar, V. A.

    2013-12-01

    There are two concepts understanding of the real Nature: balanced and imbalanced. The traditional balanced concept understanding of Nature was originated in prehistoric times to calm the frightened souls of prehistoric man and manage groups of people. The balanced concept presupposes that Nature is isotropic, balanced, etc. The balanced concept of understanding of Nature gradually has moved to science and technology. The balanced concept of understanding of Nature is dominating from the prehistoric time up to today. But always parallel and opposite was exists the concept imbalanced understanding of Nature, which presupposes that Nature is anisotropy, imbalanced, etc. The balanced concept is much simpler than Imbalanced. The balanced concept has given mankind a lot of rough description of Nature which helped to solve a lot of practical problems but with sufficient accuracy, i.e. approximately, but not with an absolute precision. While people were few, and a lot of resources, person could take from Nature only what Nature gave willingly. During this period, people feared and respected Nature and Nature was able easily compensate the activity of people. The high accuracy of the description of Nature was not needed when resources were plentiful and people were few. But now the situation is completely different. The population has become a very large and growing. Traditional resources are almost run out and the lack of resources escalates. People are not afraid of Nature and bravely try to take by force what Nature does not give voluntarily. People invaded into imbalance Nature, and Nature can no longer compensate activity of people. The era of global change is started, including those that man provokes. In the conditions of global changes is insufficiently of the approximate solutions of the traditional balanced concept. The balanced concept is exhausted, and increasingly misleads people. The balanced concept cannot solve the problems that arise in the global change

  2. Why are natural disasters not 'natural' for victims?

    International Nuclear Information System (INIS)

    Kumagai, Yoshitaka; Edwards, John; Carroll, Matthew S.

    2006-01-01

    Some type of formal or informal social assessment is often carried out in the wake of natural disasters. One often-observed phenomenon in such situations is that disaster victims and their sympathizers tend to focus on those elements of disasters that might have been avoided or mitigated by human intervention and thus assign 'undue' levels of responsibility to human agents. Often the responsibility or blame is directed at the very government agencies charged with helping people cope with and recover from the event. This phenomenon presents particular challenges for those trying to understand the social impacts of such events because of the reflexive nature of such analysis. Often the social analyst or even the government agency manager must sort through such perceptions and behavior and (at least implicitly) make judgments about which assignments of responsibility may have some validity and which are largely the result of the psychology of the disaster itself. This article presents a conceptual framework derived largely from social psychology to help develop a better understand such perceptions and behavior. While no 'magic bullet' formula for evaluating the validity of disaster victims' claims is presented, the conceptual framework is presented as a starting point for understanding this particular aspect of the psychology of natural disasters

  3. Plutonium in nature

    International Nuclear Information System (INIS)

    Madic, C.

    1994-01-01

    Plutonium in nature comes from natural sources and anthropogenic ones. Plutonium at the earth surface comes principally from anthropogenic sources. It is easily detectable in environment. The plutonium behaviour in environment is complex. It seems necessary for the future to reduce releases in environment, to improve predictive models of plutonium behaviour in geosphere, to precise biological impact of anthropogenic plutonium releases

  4. Vermont Natural Resources Atlas

    Data.gov (United States)

    Vermont Center for Geographic Information — The purpose of the�Natural Resources Atlas�is to provide geographic information about environmental features and sites that the Vermont Agency of Natural Resources...

  5. Antiplasmodial Natural Products

    Directory of Open Access Journals (Sweden)

    Cláudio R. Nogueira

    2011-03-01

    Full Text Available Malaria is a human infectious disease that is caused by four species of Plasmodium. It is responsible for more than 1 million deaths per year. Natural products contain a great variety of chemical structures and have been screened for antiplasmodial activity as potential sources of new antimalarial drugs. This review highlights studies on natural products with antimalarial and antiplasmodial activity reported in the literature from January 2009 to November 2010. A total of 360 antiplasmodial natural products comprised of terpenes, including iridoids, sesquiterpenes, diterpenes, terpenoid benzoquinones, steroids, quassinoids, limonoids, curcubitacins, and lanostanes; flavonoids; alkaloids; peptides; phenylalkanoids; xanthones; naphthopyrones; polyketides, including halenaquinones, peroxides, polyacetylenes, and resorcylic acids; depsidones; benzophenones; macrolides; and miscellaneous compounds, including halogenated compounds and chromenes are listed in this review.

  6. Is natural history really dead?: Toward the rebirth of natural history ¿Está realmente muerta la historia natural?: Hacia el renacimiento de la Historia Natural

    Directory of Open Access Journals (Sweden)

    MARY F WILLSON

    2006-06-01

    Full Text Available In recent years natural history has been derided by some scientists as an old-fashion endeavor that does not follow the model of "hard" science and therefore should be considered "dead" and replaced by modern ecology, evolutionary biology, and conservation biology. We contend that natural history has much to offer to contemporary scientists and that it has a primary role in the creative process of generating novel hypotheses and designing significant field experiments and observationsEn años recientes, la historia natural ha sido desacreditada por científicos que la consideran un modelo obsoleto de ciencia y que, en consecuencia, se trataría de una disciplina "muerta" que ha sido reemplazada por la ecología moderna, la biología evolutiva y la biología de la conservación. Argumentamos aquí que la historia natural tiene mucho que ofrecer a los científicos contemporáneos y que juega un rol principal en el proceso de creación de hipótesis y en el diseño acertado de observaciones y experimentos de campo

  7. [Out of natural order: nature in discourses about cloning and stem cell research in Brazilian newspapers].

    Science.gov (United States)

    Medeiros, Flavia Natércia da Silva

    2013-11-30

    Different conceptions of nature influence media coverage and public opinion about biotechnology. This study reports on a discourse analysis of the ideas about nature and what is natural expressed in Brazilian media coverage of cloning and stem cell research. In the discourse against this research, the biotechnologies in question are placed outside the natural order of things and deemed immoral. In the discourse of those who defend it, nature is portrayed as indifferent to the fate of humans or even cruel, or else a barrier to be overcome, while cloning and embryonic stem cells are naturalized and Dolly the sheep is anthropomorphized. The mythifying or transcendental representations of nature do not just influence public opinion, but also have ethical and political implications.

  8. Immigration, social cohesion, and naturalization

    DEFF Research Database (Denmark)

    Lægaard, Sune

    2010-01-01

    social trust do not connect with issues of naturalization at all. Other conceptions of social cohesion are either politically controversial, problematic as part of the justification of stricter naturalization requirements, or in fact justify less demanding naturalization requirements....

  9. The naturalism of the sciences.

    Science.gov (United States)

    Dawes, Gregory W; Smith, Tiddy

    2018-02-01

    The sciences are characterized by what is sometimes called a "methodological naturalism," which disregards talk of divine agency. In response to those who argue that this reflects a dogmatic materialism, a number of philosophers have offered a pragmatic defense. The naturalism of the sciences, they argue, is provisional and defeasible: it is justified by the fact that unsuccessful theistic explanations have been superseded by successful natural ones. But this defense is inconsistent with the history of the sciences. The sciences have always exhibited what we call a domain naturalism. They have never invoked divine agency, but have always focused on the causal structure of the natural world. It is not the case, therefore, that the sciences once employed theistic explanations and then abandoned them. The naturalism of the sciences is as old as science itself. Copyright © 2018 Elsevier Ltd. All rights reserved.

  10. Who's afraid of natural gas?

    International Nuclear Information System (INIS)

    Patterson, W.

    1999-01-01

    Changes in our electricity systems provoked by natural gas power generation technology are paving the way for large-scale renewables use in the future. Natural gas and gas turbines are now such a cheap and easy option for electricity generation that they appear to cast a pall over renewables. The market share of gas-fired generation continues expanding inexorably. Its cost continues to fall, setting renewables an ever more demanding competitive target. Nevertheless, paradoxical though this may sound, natural gas is actually the natural ally of renewables. Despite the fierce competitive challenge it represents, natural gas may even be the most important single factor shaping a bright future for renewables. (author)

  11. Natural gas vehicles in Italy

    International Nuclear Information System (INIS)

    Mariani, F.

    1991-01-01

    The technology of compressed natural gas (CNG) for road vehicles originated 50 years ago in Italy, always able to adapt itself to changes in energy supply and demand situations and national assets. Now, due to the public's growing concern for air pollution abatement and recent national energy policies calling for energy diversification, the commercialization of natural gas road vehicles is receiving new momentum. However, proper fuel taxation and an increased number of natural gas distribution stations are required to support this growing market potential. Operators of urban bus fleets stand to gain substantially from conversion to natural gas automotive fuels due to natural gas being a relatively cheap, clean alternative

  12. Nature and Young Children: Encouraging Creative Play and Learning in Natural Environments. Second Edition

    Science.gov (United States)

    Wilson, Ruth

    2012-01-01

    Now in its second edition, "Nature and Young Children" promotes the holistic development of children by connecting them with nature. It offers advice and guidance on how to set up indoor and outdoor nature play spaces as well as encouraging environmentally responsible attitudes, values and behaviour in your early childhood setting. Covering topics…

  13. Natural gas monthly, June 1998

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-06-01

    The Natural Gas Monthly (NGM) highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. From time to time, the NGM features articles designed to assist readers in using and interpreting natural gas information. 6 figs., 27 tabs.

  14. Natural gas monthly, October 1998

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-10-01

    The Natural Gas Monthly (NGM) highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. From time to time, the NGM features articles designed to assist readers in using and interpreting natural gas information. 6 figs., 27 tabs.

  15. Natural gas monthly, May 1999

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-05-01

    The Natural Gas Monthly (NGM) highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. From time to time the NGM features articles designed to assist readers in using and interpreting natural gas information. 6 figs., 27 tabs.

  16. Natural gas 1995: Issues and trends

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-11-01

    Natural Gas 1995: Issues and Trends addresses current issues affecting the natural gas industry and markets. Highlights of recent trends include: Natural gas wellhead prices generally declined throughout 1994 and for 1995 averages 22% below the year-earlier level; Seasonal patterns of natural gas production and wellhead prices have been significantly reduced during the past three year; Natural gas production rose 15% from 1985 through 1994, reaching 18.8 trillion cubic feet; Increasing amounts of natural gas have been imported; Since 1985, lower costs of producing and transporting natural gas have benefitted consumers; Consumers may see additional benefits as States examine regulatory changes aimed at increasing efficiency; and, The electric industry is being restructured in a fashion similar to the recent restructuring of the natural gas industry.

  17. Natural radioactivity of Turkish natural stones as building materials

    International Nuclear Information System (INIS)

    Yaprak, Guenseli; Yasar, Oezden

    2008-01-01

    Full text: The Turkey has very important natural stones potential with over 5 billion m 3 marble reserves. According to 2002 giving data the number of Turkish stones export is 303 million US Dollars. In this regards, the present study deals with 90 Turkish natural stones. The studied samples were analyzed and the concentrations in Bq/kg dry weight of radioisotopes were determined by gamma-ray spectrometry using HPGe detector. The radon exhalation rates of natural stones were also measured by using solid state nuclear track detectors (LR-115 ). The radium equivalent activity varied from 183 Bq/kg to 522 Bq/kg for granite samples and from 1 Bq/kg to 37 Bq/kg for marble samples. The value of radon exhalation rate ranged from 0.003 Bq/m 2 h -1 to 0.768 Bq/m 2 h -1 for granite samples and from 0.001 Bq/m 2 h -1 to 0.02 Bq/m 2 h -1 for marble samples. The total absorbed dose rates in air ranged from 22 to 61 n Gy h -1 for one quarter utilization of granite samples. The annual effective dose rates per person indoors were determined to be between 108 and 298 μSv y -1 for of for one quarter utilization of the materials. Applying the dose criteria recently recommended by UNSCEAR for building materials, the natural stones meet the upper dose limit of 1mSvy -1 . So, there are not restrictions for use of any Turkish commercial marble as covering materials, including Turkish granites. (author)

  18. Naturally Efficient Emitters: Luminescent Organometallic Complexes Derived from Natural Products

    Science.gov (United States)

    Zhang, Wen-Hua; Young, David J.

    2013-08-01

    Naturally occurring molecules offer intricate structures and functionality that are the basis of modern medicinal chemistry, but are under-represented in materials science. Herein, we review recent literature describing the use of abundant and relatively inexpensive, natural products for the synthesis of ligands for luminescent organometallic complexes used for organic light emitting diodes (OLEDs) and related technologies. These ligands are prepared from the renewable starting materials caffeine, camphor, pinene and cinchonine and, with the exception of caffeine, impart performance improvements to the emissive metal complexes and resulting OLED devices, with emission wavelengths that span the visible spectrum from blue to red. The advantages of these biologically-derived molecules include improved solution processibility and phase homogeneity, brighter luminescence, higher quantum efficiencies and lower turn-on voltages. While nature has evolved these carbon-skeletons for specific purposes, they also offer some intriguing benefits in materials science and technology.

  19. Nature Contacts: Employee Wellness in Healthcare.

    Science.gov (United States)

    Trau, Deborah; Keenan, Kimberly A; Goforth, Meggan; Large, Vernon

    2016-04-01

    This study was designed to ascertain the amount of outdoor, indoor, and indirect nature contact exposures hospital employees have in a workweek. Hospital employees have been found particularly vulnerable to work-related stress. Increasing the nature contact exposure for hospital employees can reduce perceived stress; stress-related health behaviors; and stress-related health outcomes from outdoor, indoor, and indirect exposures to nature. Staff on the fourth floor postsurgical unit of a large hospital (N = 42) were ask to participate in an employee questionnaire "nature contact questionnaire". This 16-item nature environment questionnaire measures the amount and types of nature contact exposures employees have during a workweek. Majority of employees reported few, if any, nature contact exposures, specifically in the area of outdoor nature contacts with limited indoor and indirect contacts. These results indicated that employees on the fourth floor postsurgical floor have limited ability to reduce stress through nature contact exposures which could impact their perceived levels of work stress and stress-related behaviors and health outcomes. Nature contact exposures are both a relatively easy and an inexpensive way to improve employee stress. These findings indicate limitations to employees' exposure to nature contacts. Healthcare environments would benefit from a concerted effort to provide increased outdoor, indoor, and indirect nature contact exposures for employees. © The Author(s) 2015.

  20. Natural gas pipeline technology overview.

    Energy Technology Data Exchange (ETDEWEB)

    Folga, S. M.; Decision and Information Sciences

    2007-11-01

    The United States relies on natural gas for one-quarter of its energy needs. In 2001 alone, the nation consumed 21.5 trillion cubic feet of natural gas. A large portion of natural gas pipeline capacity within the United States is directed from major production areas in Texas and Louisiana, Wyoming, and other states to markets in the western, eastern, and midwestern regions of the country. In the past 10 years, increasing levels of gas from Canada have also been brought into these markets (EIA 2007). The United States has several major natural gas production basins and an extensive natural gas pipeline network, with almost 95% of U.S. natural gas imports coming from Canada. At present, the gas pipeline infrastructure is more developed between Canada and the United States than between Mexico and the United States. Gas flows from Canada to the United States through several major pipelines feeding U.S. markets in the Midwest, Northeast, Pacific Northwest, and California. Some key examples are the Alliance Pipeline, the Northern Border Pipeline, the Maritimes & Northeast Pipeline, the TransCanada Pipeline System, and Westcoast Energy pipelines. Major connections join Texas and northeastern Mexico, with additional connections to Arizona and between California and Baja California, Mexico (INGAA 2007). Of the natural gas consumed in the United States, 85% is produced domestically. Figure 1.1-1 shows the complex North American natural gas network. The pipeline transmission system--the 'interstate highway' for natural gas--consists of 180,000 miles of high-strength steel pipe varying in diameter, normally between 30 and 36 inches in diameter. The primary function of the transmission pipeline company is to move huge amounts of natural gas thousands of miles from producing regions to local natural gas utility delivery points. These delivery points, called 'city gate stations', are usually owned by distribution companies, although some are owned by

  1. 77 FR 19277 - Orders Granting Authority To Import and Export Natural Gas and Liquefied Natural Gas During...

    Science.gov (United States)

    2012-03-30

    ... and Export Natural Gas and Liquefied Natural Gas During February 2012 FE Docket Nos. FREEPORT LNG...-LNG QUICKSILVER RESOURCES INC 12-12-NG UNITED ENERGY TRADING CANADA, ULC 12-13-NG ENCANA NATURAL GAS... authority to import and export natural gas and liquefied natural gas. These Orders are summarized in the...

  2. Natural gas retailing: writing the last chapter of natural gas deregulation

    International Nuclear Information System (INIS)

    Bjerkelund, T.

    1995-01-01

    Under the A greement on Natural Gas Markets and Prices of October 1985, the Canadian federal government agreed to deregulate the price of natural gas and to allow a competitive gas market to develop. Several beneficial changes that have occurred as a result of the deregulation were described, including the Industrial Gas Users Association's (IGUA) view on the marketing and sale of natural gas by local gas distributor's (LDC) and the sale within the LDC franchise. IGUA's support for the separation between LDC distribution and LDC sales and marketing activities as the last step in deregulation process, was explained. Several arguments for the opposing view were also discussed. Recommendations were made for effective separation of LDC distribution and LDC sales/marketing activities

  3. Breast reconstruction - natural tissue

    Science.gov (United States)

    ... flap; TRAM; Latissimus muscle flap with a breast implant; DIEP flap; DIEAP flap; Gluteal free flap; Transverse upper gracilis flap; TUG; Mastectomy - breast reconstruction with natural tissue; Breast cancer - breast reconstruction with natural tissue

  4. Natural games

    International Nuclear Information System (INIS)

    Anttila, Jani; Annila, Arto

    2011-01-01

    A course of a game is formulated as a physical process that will consume free energy in the least time. Accordingly, the rate of entropy increase is the payoff function that will subsume all forms of free energy that motivate diverse decisions. Also other concepts of game theory are related to their profound physical counterparts. When the physical portrayal of behavior is mathematically analyzed, the course of a game is found to be inherently unpredictable because each move affects motives in the future. Despite the non-holonomic character of the natural process, the objective of consuming free energy in the least time will direct an extensive-form game toward a Lyapunov-stable point that satisfies the minimax theorem. -- Highlights: → Behavior in the context of game theory is described as a natural process. → The rate of entropy increase, derived from statistical physics of open systems, is identified as the payoff function. → Entropy as the payoff function also clarifies motives of collaboration and subjective nature of decision making. → Evolutionary equation of motion that accounts for the course of a game is inherently unpredictable.

  5. Natural knowledge as a propaedeutic to self-betterment: Francis Bacon and the transformation of natural history.

    Science.gov (United States)

    Lancaster, James A T

    2012-01-01

    This paper establishes the 'emblematic' use of natural history as a propaedeutic to self-betterment in the Renaissance; in particular, in the natural histories of Gessner and Topsell, but also in the works of Erasmus and Rabelais. Subsequently, it investigates how Francis Bacon's conception of natural history is envisaged in relation to them. The paper contends that, where humanist natural historians understood the use of natural knowledge as a preliminary to individual improvement, Bacon conceived self-betterment foremost as a means to Christian charity, or social-betterment. It thus examines the transformation of the moralizing aspect of Renaissance natural history in Bacon's conception of his Great Instauration.

  6. Methane-bomb natural gas

    International Nuclear Information System (INIS)

    Anon.

    1993-01-01

    About 50% of the so-called 'greenhouse-effect' is not caused by CO 2 , but by more dangerous gases, among them is methane. Natural gas consists to about 98% of methane. In Austria result about 15% of the methane emissions from offtake, storage, transport (pipelines) and distribution from natural gas. A research study of the Research Centre Seibersdorf points out that between 2.5% and 3.6% of the employed natural gas in Austria emits. The impact of this emitted methane is about 29 times worse than the impact of CO 2 (caused for examples by petroleum burning). Nevertheless the Austrian CO 2 -commission states that an increasing use of natural gas would decrease the CO 2 -emissions - but this statement is suspected to be based on wrong assumptions. (blahsl)

  7. Art, Technology and Nature

    DEFF Research Database (Denmark)

    Camilla Skovbjerg Paldam and Jacob Wamberg trace the Kantian heritage of radically separating art and technology, and inserting both at a distance to nature, suggesting this was a transient chapter in history. Thus, they argue, the present renegotiation between art, technology and nature is reminiscent......Since 1900, the connections between art and technology with nature have become increasingly inextricable. Through a selection of innovative readings by international scholars, this book presents the first investigation of the intersections between art, technology and nature in post-medieval times....... Transdisciplinary in approach, this volume’s 14 essays explore art, technology and nature’s shifting constellations that are discernible at the micro level and as part of a larger chronological pattern. Included are subjects ranging from Renaissance wooden dolls, science in the Italian art academies, and artisanal...

  8. Radiation stability of animate nature

    International Nuclear Information System (INIS)

    Romanov, G.N.; Spirin, D.A.

    1990-01-01

    The main principles of radiation safety for animate nature including provisions for biological species protection and main requirement for animate nature radiation protection, which is the guarantee of any ecosystem integrity, are discussed. Ecosystem should be taken as the objective unit for animate nature radiation protection. The maximum dose of biot irradiation may amount to 0.5 Gy/year, which is 20-fold lower than the main dose limit for animate nature and 40-fold lower than ecological dose limits for conifers as the weakest radiostable member in ecosystem, at environment radioactive contamination determined by radiation safety standards. The radiation protection of animate nature is guaranteed at such levels of environment radioactive contamination

  9. Influência do cultivo de milho transgênico em organismos não-alvo (Coleoptera : scarabaeinae) e da ingestão indireta através da cadeia trófica

    OpenAIRE

    Campos, Renata Calixto

    2016-01-01

    Tese (doutorado) - Universidade Federal de Santa Catarina, Centro de Ciências Biológicas, Programa de Pós-Graduação em Ecologia, Florianópolis, 2016. O uso de plantas transgênicas ou plantas geneticamente modificadas (GM) que expressam genes com atividade inseticida representam uma alternativa para controlar insetos pragas. As plantas transgênicas resistentes a insetos expressam genes derivados a partir da bactéria Bacillus thuringiensis (Bt). Durante a esporulação essa bactéria produz...

  10. PATELLOFEMORAL MODEL OF THE KNEE JOINT UNDER NON- STANDARD SQUATTING

    OpenAIRE

    GUSZTÁV FEKETE; BÉLA MÁLNÁSI CSIZMADIA; MAGD ABDEL WAHAB; PATRICK DE BAETS; LIBARDO V. VANEGAS-USECHE; ISTVÁN BÍRÓ

    2014-01-01

    Los modelos analíticos disponibles para calcular las fuerzas patelofemorales de la rodilla están limitados al movimiento estándar de cuclillas cuando el centro de gravedad es fijo horizontalmente. En este artículo se presenta un modelo para calcular con exactitud las fuerzas patelofemorales, teniendo en cuenta el cambio de posición del centro de gravedad del tronco durante una sentadilla profunda (posición de sentadilla modificada). Se valida la exactitud del modelo desarrollado mediante comp...

  11. Orientación del rol sexual en mujeres que trabajan en profesiones sexualmente tipificadas

    Directory of Open Access Journals (Sweden)

    Miriam Baruch Goldstein

    1991-06-01

    Full Text Available Se compararon 288 mujeres peruanas de profesiones tradicionalmente masculinas y femeninas, en la autopercepción de su masculinidad y femineidad a nivel global y en los contextos familiar y laboral. Se empleó la Escala de Orientación Sexual de Ragúz, SROS (1989 y versiones modificadas de la misma. Si bien el análisis de varianza y el t Student no evidenciaron diferencias en la ORS global o familiar, los grupos difirieron en su ORS laboral.

  12. Atmosfera modificada e refrigeração para conservação pós-colheita de uva 'Niagara Rosada' Modified atmosphere and cold storage for postharvest conservation of 'Niagara Rosada' table grape

    Directory of Open Access Journals (Sweden)

    Patrícia Cia

    2010-10-01

    Full Text Available O objetivo deste trabalho foi avaliar os efeitos da atmosfera modificada na conservação pós-colheita da uva 'Niagara Rosada' armazenada sob refrigeração, em dois experimentos. No primeiro experimento avaliou-se o acondicionamento de cachos nas seguintes embalagens: papelão ondulado (testemunha; tereftalato de polietileno (PET; cloreto de polivinila (PVC 17 μm; polietileno linear de baixa densidade (PELBD 25 μm; e PELBD 50 μm. Em outro experimento, avaliaram-se os sistemas de acondicionamento: sacolas de plástico abertas (testemunha; polietileno de baixa densidade (PEBD 25 μm; PEBD 25 μm, com injeção de mistura gasosa (21% O2/5% CO2; PEBD 25 μm (21% O2/10% CO2; PEBD 25 μm (21% O2/20% CO2. Os cachos foram armazenados a 1±1°C e 90±5% de umidade relativa (UR por 28 dias, seguido de armazenamento em condições do ambiente (25±2°C e 80±5% UR. Os cachos foram avaliados quanto à perda de massa de matéria fresca, firmeza, cor das bagas, esbagoamento, sólidos solúveis totais (SST, acidez titulável (AT, relação SST/AT e incidência de podridões. O filme PELBD 50 μm, a partir do 14º dia a 1°C, seguido por mais três dias a 25°C, causou a fermentação dos cachos. As embalagens PELBD 25 μm, com ou sem injeção de mistura gasosa, e PVC 17 μm reduzem a perda de massa de matéria fresca dos cachos, mas não reduzem o esbagoamento e a incidência de podridões.The objective of this work was to evaluate the effect of the modified atmosphere, on the storage life of 'Niagara Rosada' Table grape kept under refrigeration in two experiments. In the first one, grape clusters stored in different package materials were evaluated: corrugated cardboard boxes, polyethylene tereftalate (PET; 17-μm polyvinyl chloride (PVC; 25-μm low density linear polyethylene film (PELDB; and 50-μm PELDB. On a second assay, different packaging systems were evaluated: opened plastic bags; 25-μm low density polyethylene film (PEBD; 25-μm PEBD, with

  13. Natural Gas Regulation

    International Nuclear Information System (INIS)

    1995-01-01

    The regulation of Natural Gas. Natural gas Regulation clarifies and consolidates the legal and institutional framework for development of the industry through six principal elements: 1) Establishment of a vision of the industry. 2) Development of regulatory objectives. 3) Determination of relationships among industry participants. 4) Clear specification of the role of PEMEX in the industry. 5) Definition of the functions of the Regulatory authority. 6) Creation of a transition regime. In parallel with the development of the substantive legal framework, the law of the Comision Reguladora de Energia (CRE) was also enacted by Congress in October 1995 to strength the institutional framework and implement the legal changes. This law defines the CRE as an agency of the Energy Ministry with technical, operational, and budgetary autonomy, and responsibility for implementing natural gas industry regulation. (Author)

  14. Canadian natural gas

    International Nuclear Information System (INIS)

    Lucas, D.A.

    1991-01-01

    Canada's natural gas industry enjoys a quiet confidence as it looks ahead to the 1990s. In this paper, the author explains why, despite some critical uncertainties, the optimism endures. Reviewing the current conditions of supply, production, consumption, pipelines, and pipeline expansion plans, the author contends that the New World of the 1990s will belong to natural gas. The author's assessment of natural gas markets proceeds far beyond the borders of Canada. The author examines the determinants of gas prices throughout North America and he identifies the one force that promises to seize almost complete control of gas prices throughout the continent. While the analysis points out the attributes of this new pricing regime, it also names the obstacles that could prevent this emerging mechanism from assuming its anticipated position

  15. 77 FR 12274 - Orders Granting Authority To Import and Export Natural Gas and Liquefied Natural Gas During...

    Science.gov (United States)

    2012-02-29

    ... Authority To Import and Export Natural Gas and Liquefied Natural Gas During January 2012 AGENCY: Office of... LNG, LP 11-98-LNG ENERGY PLUS NATURAL GAS LLC 11-155-NG BROOKFIELD ENERGY MARKETING L.P 12-03-NG WPX... granting authority to import and export natural gas and liquefied natural gas. These Orders are summarized...

  16. Sebastian Kneipp and the Natural Cure Movement of Germany: Between Naturalism and Modern Medicine

    Directory of Open Access Journals (Sweden)

    Youkyung KO

    2016-12-01

    Full Text Available This study discusses the historical significance of the Natural Cure Movement of Germany, centering on the Kneipp Cure, a form of hydrotherapy practiced by Father Sebastian Kneipp (1821-1897. The Kneipp Cure rested on five main tenets: hydrotherapy, exercise, nutrition, herbalism, and the balance of mind and body. This study illuminates the reception of the Kneipp Cure in the context of the trilateral relationship among the Kneipp Cure, the Natural Cure Movement in general, and modern medicine. The Natural Cure Movement was ideologically based on naturalism, criticizing industrialization and urbanization. There existed various theories and methods in it, yet they shared holism and vitalism as common factors. The Natural Cure Movement of Germany began in the early 19th century. During the late 19th century and the early 20th century, it became merged in the Lebensreformbewegung (life reform movement which campaigned for temperance, anti-tobacco, and anti-vaccination. The core of the Natural Cure Movement was to advocate the world view that nature should be respected and to recognize the natural healing powers of sunlight, air, water, etc. Among varied natural therapies, hydrotherapy spread out through the activities of some medical doctors and amateur healers such as Johann Siegmund Hahn and Vincenz Prie β nitz. Later, the supporters of hydrotherapy gathered together under the German Society of Naturopathy. Sebastian Kneipp, one of the forefathers of hydrotherapy, is distinguished from other proponents of natural therapies in two aspects. First, he did not refuse to employ vaccination and medication. Second, he sought to be recognized by the medical world through cooperating with medical doctors who supported his treatment. As a result, the Kneipp cure was able to be gradually accepted into the medical world despite the “quackery” controversy between modern medicine and the Natural Cure Movement. Nowadays, the name of Sebastian Kneipp

  17. Preparation and properties of natural nanocomposites based on natural rubber and naturally occurring halloysite nanotubes

    International Nuclear Information System (INIS)

    Rooj, Sandip; Das, Amit; Thakur, Varun; Mahaling, R.N.; Bhowmick, Anil K.; Heinrich, Gert

    2010-01-01

    A 'green' composite based on natural halloysite nanotubes (HNTs) and natural rubber (NR) was prepared by mechanical mixing. A silane coupling agent, bis (triethoxysilylpropyl)-tetrasulphide, was utilized to enhance the properties of these composites. It was observed that the reinforcing activity of HNTs was superior to commercial silica coupled with the same amount of silane coupling agent. Moreover the on-set thermal degradation decomposition temperature was improved by ∼64 o C with the addition of 10 parts HNTs per hundred of rubber. Transmission electron microscopic images confirmed the good dispersion of the HNTs in the rubber matrix, whereas X-ray diffraction studies showed a little change in interlayer spacing between the two silicate layers of HNTs.

  18. Use of natural ingredients to control growth of Clostridium perfringens in naturally cured frankfurters and hams.

    Science.gov (United States)

    Jackson, Armitra L; Kulchaiyawat, Charlwit; Sullivan, Gary A; Sebranek, Joseph G; Dickson, James S

    2011-03-01

    A major concern for processed meats marketed as natural/organic is that they do not contain nitrite in concentrations known to be most effective for inhibiting foodborne pathogens. Supplemental treatments to increase the level and consistency of antimicrobial protection in these products may be important to provide consumers with the degree of safety that they have come to expect from conventionally cured meats. Therefore, the objective of this study was to identify and test ingredients that might improve processed meat product safety without altering their natural/organic status. Eight treatments of hams and frankfurters were prepared: (A) uncured control (typical ingredients except nitrite and nitrate); (B) conventionally cured control (erythorbate, nitrite, and a lactate-diacetate blend); (C) natural nitrate cure (including starter culture containing Staphylococcus carnosus); (D) natural nitrate cure (culture and natural antimicrobial A containing a vinegar, lemon, and cherry powder blend); (E) natural nitrate cure (culture and antimicrobial B containing a cultured sugar and vinegar blend); (F) natural nitrite cure without additional antimicrobials; (G) natural nitrite cure with natural antimicrobial A; and (H) natural nitrite cure with antimicrobial B. For the hams, treatments C, D, E, and H impacted growth of Clostridium perfringens to the same extent (P cured control (approximately 2 log less growth over time than uncured control). For frankfurters, treatments D, G, and H had an effect (approximately 1 log) on growth equivalent to that of the conventionally cured control (P cured meats have more potential for pathogen growth than conventionally cured products, but supplemental natural ingredients offer safety improvement.

  19. Natural radiation, protection against its effects and maintaining safe natural environment

    International Nuclear Information System (INIS)

    Alhassan, Muhammad

    2015-01-01

    Exposure to naturally occurring radioactivity and its consequences is an issue that needs the global concern, as practices bringing such radioactive materials closer to human environment through mining, building, industrial applications and food production and preservation is continuously increasing, in addition to the daily consumption in foods such as banana, carrot, potato and drinking water. Although it has direct and indirect impacts affecting human health that in some cases lead to the loss of lives and polluting natural environment, it is an inevitable task that necessitates devising some means of its minimization and protection against its hazardous effects. This could be achieved by the use of expertise ideas and by the creation of awareness and sharing related information with the people concerned and the general public. This paper gives an overview on the radiation present in natural environment, its sources, mechanism of its effects. The paper compares the radiation dose limits with the average doses from these sources in order to raise the challenges facing researchers, governments and the general individuals with regard to this issue. The paper also proposed applicable solutions to reduce the risks due to the exposure to natural radiation to ground level. (author)

  20. Electrospinning of PVC with natural rubber

    Science.gov (United States)

    Othman, Muhammad Hariz; Mohamed, Mahathir; Abdullah, Ibrahim

    2013-11-01

    Polyvinyl chloride (PVC) was mixed with natural rubbers which are liquid natural rubber (LNR), liquid epoxidised natural rubber (LENR) and liquid epoxidised natural rubber acrylate (LENRA) for a preparation of a fine non-woven fiber's mat. PVC and each natural rubbers(PVC:LENR, PVC:LNR and PVC:LENRA) were mixed based on ratio of 70:30. Electrospinning method was used to prepare the fiber. The results show that the spinnable concentration of PVC/ natural rubber/THF solution is 16 wt%. The morphology, diameter, structure and degradation temperature of electrospun fibers were investigated by scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). SEM photos showed that the morphology and diameter of the fibers were mainly affected by the addition of natural rubber. TGA results suggested that PVC electrospun fiber has higher degradation temperature than those electrospun fibers that contain natural rubber.

  1. Electrospinning of PVC with natural rubber

    International Nuclear Information System (INIS)

    Othman, Muhammad Hariz; Abdullah, Ibrahim; Mohamed, Mahathir

    2013-01-01

    Polyvinyl chloride (PVC) was mixed with natural rubbers which are liquid natural rubber (LNR), liquid epoxidised natural rubber (LENR) and liquid epoxidised natural rubber acrylate (LENRA) for a preparation of a fine non-woven fiber’s mat. PVC and each natural rubbers(PVC:LENR, PVC:LNR and PVC:LENRA) were mixed based on ratio of 70:30. Electrospinning method was used to prepare the fiber. The results show that the spinnable concentration of PVC/ natural rubber/THF solution is 16 wt%. The morphology, diameter, structure and degradation temperature of electrospun fibers were investigated by scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). SEM photos showed that the morphology and diameter of the fibers were mainly affected by the addition of natural rubber. TGA results suggested that PVC electrospun fiber has higher degradation temperature than those electrospun fibers that contain natural rubber

  2. Electrospinning of PVC with natural rubber

    Energy Technology Data Exchange (ETDEWEB)

    Othman, Muhammad Hariz; Abdullah, Ibrahim [Department of Chemistry, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia); Mohamed, Mahathir [Radiation Processing Technology Division (BTS), Malaysian Nuclear Agency, Bangi, 43000, Kajang (Malaysia)

    2013-11-27

    Polyvinyl chloride (PVC) was mixed with natural rubbers which are liquid natural rubber (LNR), liquid epoxidised natural rubber (LENR) and liquid epoxidised natural rubber acrylate (LENRA) for a preparation of a fine non-woven fiber’s mat. PVC and each natural rubbers(PVC:LENR, PVC:LNR and PVC:LENRA) were mixed based on ratio of 70:30. Electrospinning method was used to prepare the fiber. The results show that the spinnable concentration of PVC/ natural rubber/THF solution is 16 wt%. The morphology, diameter, structure and degradation temperature of electrospun fibers were investigated by scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). SEM photos showed that the morphology and diameter of the fibers were mainly affected by the addition of natural rubber. TGA results suggested that PVC electrospun fiber has higher degradation temperature than those electrospun fibers that contain natural rubber.

  3. Natural pet food: a review of natural diets and their impact on canine and feline physiology.

    Science.gov (United States)

    Buff, P R; Carter, R A; Bauer, J E; Kersey, J H

    2014-09-01

    The purpose of this review is to clarify the definition of "natural" as it pertains to commercial pet food and to summarize the scientific findings related to natural ingredients in pet foods and natural diets on the impact of pet health and physiology. The term "natural," when used to market commercial pet foods or pet food ingredients in the United States, has been defined by the Association of American Feed Control Officials and requires, at minimum, that the pet food be preserved with natural preservatives. However, pet owners may consider natural as something different than the regulatory definition. The natural pet food trend has focused on the inclusion of whole ingredients, including meats, fruits, and vegetables; avoiding ingredients perceived as heavily processed, including refined grains, fiber sources, and byproducts; and feeding according to ancestral or instinctual nutritional philosophies. Current scientific evidence supporting nutritional benefits of natural pet food products is limited to evaluations of dietary macronutrient profiles, fractionation of ingredients, and the processing of ingredients and final product. Domestic cats select a macronutrient profile (52% of ME from protein) similar to the diet of wild cats. Dogs have evolved much differently in their ability to metabolize carbohydrates and select a diet lower in protein (30% of ME from protein) than the diet of wild wolves. The inclusion of whole food ingredients in natural pet foods as opposed to fractionated ingredients may result in higher nutrient concentrations, including phytonutrients. Additionally, the processing of commercial pet food can impact digestibility, nutrient bioavailability, and safety, which are particularly important considerations with new product formats in the natural pet food category. Future opportunities exist to better understand the effect of natural diets on health and nutrition outcomes and to better integrate sustainable practices in the production of

  4. More natural gas

    International Nuclear Information System (INIS)

    Leprince, P.; Valais, M.

    1993-01-01

    This paper reports that large resources and growing markets are the salient prospects of natural gas for the coming decades. The greater impact of natural gas on the worldwide energy market can become a reality if several scientific disciplines can be mobilized in order to succeed in cutting production costs. Modeling, mechanics of complex fluids, and physical chemistry of interfaces are basic disciplines for understanding and mastering the gas processing technologies

  5. The Naturalized Nation: Anchoring, Objectification and Naturalized Social Representations of History

    Directory of Open Access Journals (Sweden)

    Eemeli Hakoköngäs

    2016-12-01

    Full Text Available This study focuses on the connection between social representations of history and collective memory from the perspective of elementary concepts of social representations theory: anchoring, objectification and naturalization. The aims of the study are to arrive at a conceptual clarity of this connection and demonstrate how to apply basic concepts of social representations theory to the study of collective memory. The study also focuses on the naturalized characteristics of Finnish history. The data consist of the covers of twenty Finnish history books between the years 1965 and 2014. All the covers are embellished with typography or visual images. The covers were analysed using a semiotic approach in which the interest is in the description (denotation, the associations (connotation and the meaning system these construe (myth. The analysis shows how national history is concretized with visual images (objectification, how the meaning of representation is conveyed (anchoring and how collective memory is maintained (naturalization, transmitted and shaped during the years. The results show how the stable collective memories and changing social representations of history are interacting. The most frequently used visual element was the colour blue, which alludes to the Finnish flag, a symbol of the nation that represents the core of Finnish history. The study suggests that it is possible to conceptualize collective memories as naturalized social representations of history. It shows how processes of anchoring and objectification serve as tools of collective memory and how the naturalized conceptions are subtly changed. In addition, the study develops the use of visual semiotic analysis in social representations research.

  6. Nature-Based Solutions in the EU: Innovating with nature to address social, economic and environmental challenges.

    Science.gov (United States)

    Faivre, Nicolas; Fritz, Marco; Freitas, Tiago; de Boissezon, Birgit; Vandewoestijne, Sofie

    2017-11-01

    Contemporary societies are facing a broad range of challenges, from pressures on human health and well-being to natural capital depletion, and the security of food, water and energy. These challenges are deeply intertwined with global processes, such as climate change and with local events such as natural disasters. The EU's research & innovation (R&I) policy is now seeking to address these challenges from a new perspective, with Nature-Based Solutions, and turn them into innovation opportunities that optimise the synergies between nature, society and the economy. Nature-Based Solutions can be an opportunity for innovation, and are here promoted by both policymakers and practitioners as a cost-effective way of creating a greener, more sustainable, and more competitive economy. Since 2013, the European Commission has devoted particular attention to Nature-Based Solutions through consultations and dialogues that sought to make the concept of these solutions more concrete and to define the concept's place within the spectrum of ecosystem-based approaches. In 2014, the Commission launched an expert group, which conducted further analysis, and made recommendations to help increase the use of Nature-Based Solutions and bring nature back into cities. In 2015, a survey was conducted on citizens' views and perceptions of 'Nature in Cities' to provide further insight for future work. Based on these elements and on results from running EU projects, the Commission has developed an R&I agenda for Nature-Based Solutions and has published targeted calls for proposals for large-scale demonstration projects in this field in 2016 and 2017. Additional R&I actions at EU level that promote systemic Nature-Based Solutions and their benefits to cities and territories are planned with the aim to improve the implementation capacity and evidence base for deploying Nature-Based Solutions and developing corresponding future markets. They are also expected to foster an interdisciplinary R

  7. Naturalness as an educational value

    DEFF Research Database (Denmark)

    Frølund, Sune

    2016-01-01

    Existentialism and postmodernism have both abandoned the idea of a human nature. Also, the idea of naturalness as a value for education has been targeted as a blind for conservative ideology. There are, however, good reasons to re-establish a sound concept of human naturalness. First of all...

  8. Naturalness and Animal Welfare.

    Science.gov (United States)

    Yeates, James

    2018-04-05

    Naturalness is considered important for animals, and is one criterion for assessing how we care for them. However, it is a vague and ambiguous term, which needs definition and assessments suitable for scientific and ethical questions. This paper makes a start on that aim. This paper differentiates the term from other related concepts, such as species-typical behaviour and wellbeing. It identifies contingent ways in which naturalness might be used, as: (i) prompts for further welfare assessment; (ii) a plausible hypothesis for what safeguards wellbeing; (iii) a threshold for what is acceptable; (iv) constraints on what improvements are unacceptable; and (v) demarcating what is not morally wrong, because of a lack of human agency. It then suggests an approach to evaluating animals' behaviour that is quantitative, is based on reality, and which assesses naturalness by degrees. It proposes classing unaffected wild populations as natural by definition. Where animals might have been affected by humans, they should be compared to the closest population(s) of unaffected animals. This approach could allow us both to assess naturalness scientifically, and to make practical decisions about the behaviour of domestic animals.

  9. Combinatorial synthesis of natural products

    DEFF Research Database (Denmark)

    Nielsen, John

    2002-01-01

    Combinatorial syntheses allow production of compound libraries in an expeditious and organized manner immediately applicable for high-throughput screening. Natural products possess a pedigree to justify quality and appreciation in drug discovery and development. Currently, we are seeing a rapid...... increase in application of natural products in combinatorial chemistry and vice versa. The therapeutic areas of infectious disease and oncology still dominate but many new areas are emerging. Several complex natural products have now been synthesised by solid-phase methods and have created the foundation...... for preparation of combinatorial libraries. In other examples, natural products or intermediates have served as building blocks or scaffolds in the synthesis of complex natural products, bioactive analogues or designed hybrid molecules. Finally, structural motifs from the biologically active parent molecule have...

  10. Managing soil natural capital

    DEFF Research Database (Denmark)

    Cong, Ronggang; Termansen, Mette; Brady, Mark

    2017-01-01

    Farmers are exposed to substantial weather and market related risks. Rational farmers seek to avoid large losses. Future climate change and energy price fluctuations therefore make adaptating to increased risks particularly important for them. Managing soil natural capital—the capacity of the soil...... to generate ecosystem services of benefit to farmers—has been proven to generate the double dividend: increasing farm profit and reducing associated risk. In this paper we explore whether managing soil natural capital has a third dividend: reducing the downside risk (increasing the positive skewness of profit......). This we refer to as the prudence effect which can be viewed as an adaptation strategy for dealing with future uncertainties through more prudent management of soil natural capital. We do this by developing a dynamic stochastic portfolio model to optimize the stock of soil natural capital—as indicated...

  11. Optimizing color reproduction of natural images

    NARCIS (Netherlands)

    Yendrikhovskij, S.N.; Blommaert, F.J.J.; Ridder, de H.

    1998-01-01

    The paper elaborates on understanding, measuring and optimizing perceived color quality of natural images. We introduce a model for optimal color reproduction of natural scenes which is based on the assumption that color quality of natural images is constrained by perceived naturalness and

  12. Radioactivity. Death prinicple in nature; Radioaktivitaet. Das Todesprinzip in der Natur

    Energy Technology Data Exchange (ETDEWEB)

    Russell, W.; Russell, L.

    2006-07-01

    Walter Russell's knowledge of the two basic Principles of the material universe, concentration and radiation, strongly suggests that the radioactivity is the ''death principle'' of creation. In its natural environment, radioactive radiation is vital for the overall balance, however, when spread out across the entire world, it causes massive global warming and turns planet earth into a hot desert. Part I: What is Atomic Energy?; How Radioactivity Kills; The World Voice. Part II: The True Nature of This Mind and Motion Universe; Prelude - The Transformation of Man; We Define God; The True Nature of Electricity and Gravitation; Our Eternal Universe; The Oneness of Gravity and Magnetism; The Mind Nucleus of the Atom; The Material Nucleus of the Atom. Part III: The Bridge Between Man and God. (orig./GL)

  13. EEC's: natural uramium supplies

    International Nuclear Information System (INIS)

    Anon.

    1981-01-01

    The demand for nuclear fuel to supply the nuclear plants within the ECC (31,200 MW at the end of last year) totalled nearly 9,600 tons of natural uranium and 4,900 of separation work units (SWU). Once reactors currently under construction come into service, the demand for natural uranium will reach 13,200 tons by 1985 and that for SWUs to 8,600. If one takes the years 1981 to 1985, total natural uranium needs during this period will be 56,300 tons and those for SWUs 35.100 [fr

  14. The unnatural racial naturalism.

    Science.gov (United States)

    Spencer, Quayshawn

    2014-06-01

    In the recent article, "Against the New Racial Naturalism", Adam Hochman (2013, p. 332) argues that new racial naturalists have been too hasty in their racial interpretation of genetic clustering results of human populations. While Hochman makes a number of good points, the purpose of this paper is to show that Hochman's attack on new racial naturalists is misguided due to his definition of 'racial naturalism'. Thus, I will show that Hochman's critique is merely a consequence of an unnatural interpretation of racial naturalism. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Can Nature Protection be Unsustainable? Models Behind Nature Protection in New Zealands National Parks

    Science.gov (United States)

    Hauhs, Michael; Bogner, Christina

    2013-04-01

    Nature protection can be justified by intrinsic values of life. Western culture sees nature as an autonomous system. Thus, nature protection is often synonymous with refraining from human interference as much as possible. This, however, can pose at least technical problems. Indeed, historical human impacts such as introduced species are often irreversible. In such cases refraining from human interference to protect threatened species is not an adequate management response. Nature protection in New Zealand is a prominent example. Many introduced species make a non-interventionist attitude infeasible to protect endemic species such as kiwis. Actually, active human interference is necessary to attain this goal. Therefore, one may consider nature protection as another form of land use. As any other form of land use, it needs standards of proper management (i.e. explicit goals, assessment, intervention etc.). In other words, it has to be shown to be sustainable. However, sustainability may rigorously be defined as an attribute of past land use only. Instantaneous positive indicators of sustainability may be elusive. At best it can be decided by observation whether or not a land use has been (not) sustainable until now. Stakeholders of nature protection have often different (implicit) concepts or models of nature in mind. This can lead to conflicts when it comes to management decisions. For example, the methods by which conservationists in New Zealand seek to re-establish historical species assemblages (e.g. aerial drop of poison into national parks) have come under criticism of animal rights groups as non-humane. We propose to use abstract modelling language to classify these concepts of nature protection and related issues. We show that from modelling perspective these conflicts pose a basic science problem rather than an applied science problem. This makes the delegation into existing disciplines so hard. We discuss possible implications for nature protection

  16. Buying natural gas in the spot market: risks related to the natural gas industry globalization; Aquisicao de gas natural em bases 'spot': riscos associados a globalizacao da industria do gas natural

    Energy Technology Data Exchange (ETDEWEB)

    Mathias, Melissa Cristina [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil); Szklo, Alexandre Salem [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE). Programa de Planejamento Energetico

    2008-07-01

    The growth of the international natural gas trade during the last decade resulted in the expectation that this product would be traded as a commodity. This expectation created a boom in the investments related to the commercialization of natural gas between borders, especially in the distinct segments of the chain of liquefied natural gas (LNG). Different agents launched themselves into liquefaction and regasification enterprises, and the ordering of ships also showed significant growth. Despite that, the natural gas market still cannot be considered global, and international gas transactions are primarily done within regional markets. This article investigates the challenges posed to the constitution of a global natural gas market. These challenges represent risks to the commercialization of this product in spot bases, for the agents that launch themselves into projects to export or import LNG to be commercialized through short term contracts in the international market for this product. (author)

  17. Adsorptive storage of natural gas

    International Nuclear Information System (INIS)

    Yan, Song; Lang, Liu; Licheng, Ling

    2001-01-01

    The Adsorbed Natural Gas (ANG) storage technology is reviewed. The present status, theoretical limits and operational problems are discussed. Natural gas (NG) has a considerable advantage over conventional fuels both from an environmental point of view and for its natural abundance. However, as well known, it has a two fold disadvantage compared with liquid fuels: it is relatively expensive to transport from the remote areas, and its energy density (heat of combustion/volume) is low. All these will restrict its use. Compressed natural gas (CNG) may be a solution, but high pressures are needed (up to 25 MPa) for use in natural-gas fueled vehicles, and the large cost of the cylinders for storage and the high-pressure facilities necessary limit the practical use of CNG. Alternatively, adsorbed natural gas (ANG) at 3 - 4 MPa offers a very high potential for exploitation in both transport and large-scale applications. At present, research about this technology mainly focuses on: to make adsorbents with high methane adsorption capacity; to make clear the effects of heat of adsorption and the effect of impurities in natural gas on adsorption and desorption capacity. This paper provides an overview of current technology and examines the relations between fundamentals of adsorption and ANG storage. (authors)

  18. The use of compressed natural gas as a strategy of development of natural gas industry; Utilizacao do GNC (Gas Natural Comprimido) como estrategia de desenvolvimento da industria do gas natural

    Energy Technology Data Exchange (ETDEWEB)

    Bock, Jucemara [Companhia de Gas do Estado do Rio Grande do Sul (Sulgas), Porto Alegre, RS (Brazil). Coordenacao de Segmento Veicular; Rickmann, Cristiano [Companhia de Gas do Estado do Rio Grande do Sul (Sulgas), Porto Alegre, RS (Brazil). Gerencia de Novos Negocios; Maestri, Juares [Companhia de Gas do Estado do Rio Grande do Sul (Sulgas), Porto Alegre, RS (Brazil). Gerencia de Mercado de Grandes Consumidores

    2008-07-01

    This work emphasizes the Compressed Natural Gas (CNG) as modal of transport, used by the Company of Gas of the State of Rio Grande do Sul - Sulgas, through experience in pioneering project in Brazil: the introduction of the technology of Compressed Natural Gas (CNG) to assist areas where there is not the infrastructure of pipeline for the transport. The article offers a display of the project of expansion of the Natural gas in Rio Grande do Sul, through the supply of CNG to the company Tramontina in Carlos Barbosa's city in the year of 2002. The last aspect focused by this article demonstrates as the use of this transport technology impelled the development of the transport market in the State and it has been used as an important strategy for the development of the market of Natural Gas Vehicle (NGV) in the state. (author)

  19. Natural-gas supply-and-demand problems

    International Nuclear Information System (INIS)

    Hatamian, H.

    1998-01-01

    World natural-gas consumption quadrupled in the 30 years from 1966 to 1996, and natural gas now provides 22% of the total world energy demand. The security of natural-gas supply is paramount and rests with the suppliers and the consumers. This paper gives an overview of world natural-gas supply and demand and examines the main supply problems. The most important nonpredictable variables in natural-gas supply are worldwide gas price and political stability, particularly in regions with high reserves. Other important considerations are the cost of development/processing and the transport of natural gas to market, which can be difficult to maintain if pipelines pass through areas of political instability. Another problem is that many countries lack the infrastructure and capital for effective development of their natural-gas industry. Unlike oil, the cost of transportation of natural gas is very high, and, surprisingly, only approximately 16% of the total world production currently is traded internationally

  20. Natural Selection and Morality

    Directory of Open Access Journals (Sweden)

    Alejandro Rosas

    2006-12-01

    Full Text Available Resumen:En este ensayo abordo los intentos, relativamente recientes, de dar una explicación de la moralidad como adaptación por selección natural. Mi exposición tiene una introducción y cuatro partes: en la primera explico en qué consiste la paradoja del altruismo biológico. En la segunda expongo la solución que apela a la selección de grupos, recientemente resurgida; la solución que presuntamente aplicó Charles Darwin cuando formuló sus reflexiones biológicas sobre la moralidad humana. En la tercera expongo la solución sociobiológica, que opta por negar que la selección natural pueda explicar directamente la moralidad humana. La moralidad se presenta más bien como opuesta a la naturaleza diseñada por selección natural. En la cuarta parte desarrollo brevemente una explicación de la moralidad como adaptación que beneficia a los individuos. No opone la moralidad a la naturaleza, ni apela a la selección de grupos. Se sirve de un mecanismo de selección que opera a través de preferencias en la interacción social.Abstract:In this essay, I address recent attempts to account for morality as an adaptation due to natural selection. After a brief introduction, my exposition has four sections. I first explain the paradox of biological altruism. Second, I explain the solution to the paradox in terms of group selection. This solution was presumably applied by Darwin himself as he discussed human morality, and it has experienced a recent revival, though it remains suspicious to most biologists. In the third section I offer a socio-biological solution that opts for denying that morality can be explained by any form of natural selection. Morality is opposed to human nature as designed by natural selection. In the fourth, I argue for an explanation in terms of individual selection. It does not oppose morality to nature, and does not need the workings of group selection; rather, it operates through the agents’ psychological preferences

  1. Hiking tourism development in protected areas and nature hazard prevention in the Lake Baikal natural territory

    Directory of Open Access Journals (Sweden)

    Luzhkova Natalia

    2013-01-01

    Full Text Available Since 2010, recreational development has been permitted in strict nature reserves (zapovedniks in Russia, the most highly protected category of Russian Federal Protected Areas. As zapovedniks comply with the 1b IUCN category for wilderness preservation, human activities within the reserves have been limited and, consequently, there has been little research on the natural hazard impact for tourism. The type of recreational use permitted in the territories and their buffer zones is called Educational Tourism. It is identified as “as a specialized type of ecological tourism where the main goal is an introduction to natural and cultural attractions”. Hiking is seen as one of these suitable types of tourism within the territories of zapovedniks, due to its low impact on natural features. As hiking trails are laid through natural landscapes, it is possible that natural disasters can both damage the infrastructure and cause fatal injuries for visitors. During the planning stages of trail construction, natural hazard monitoring should be conducted. Baikalskii Nature Biosphere Zapovednik in the Lake Baikal region is used as a model territory where scientific research and engineering are employed to better develop hiking tourism. Along with the monitoring of natural processes, several scenarios for trail planning, construction, and maintenance are being analyzed under the threat of mud slides, avalanches and floods.

  2. Natural gas for vehicles

    International Nuclear Information System (INIS)

    Chauveron, S. de

    1996-01-01

    This article presents compressed natural gas for vehicles (CNG), which can provide considerable advantages both as an alternative fuel and as a clean fuel. These assets are not only economic but also technical. The first part deals with what is at stake in developing natural gas as a motor fuel. The first countries to use CNG were those with natural gas resources in their subsoil. Today, with a large number of countries having to cope with growing concern about increasing urban pollution, natural gas is also seen as a clean fuel that can help cut vehicle pollutant emissions dramatically. In the second part a brief technical descriptions is given of CNG stations and vehicles, with the aim of acquainting the reader with some of CNG's specific technical features as compared to gasoline and diesel oil. Here CNG technologies are seen to be very close to the more conventional ones. (author)

  3. Natural gas consumption and economic growth: Are we ready to natural gas price liberalization in Iran?

    International Nuclear Information System (INIS)

    Heidari, Hassan; Katircioglu, Salih Turan; Saeidpour, Lesyan

    2013-01-01

    This paper examines the relationship between natural gas consumption and economic growth in Iran within a multivariate production model. We also investigate the effects of natural gas price on its consumption and economic growth using a demand side model. The paper employs bounds test approach to level relationship over the period of 1972–007. We find evidence of bidirectional positive relationship between natural gas consumption and economic growth in short-run and long-run, based on the production model. The findings also suggest that real GDP growth and natural gas have positive and negative impacts on gross fixed capital formation, respectively. Employment, however, was found to have negative but insignificant impact on gross fixed capital formation. Moreover, the estimation results of demand side model suggest that natural gas price has negative and significant impact on natural gas consumption only in the long-run, though there is insignificant impact on economic growth. These results imply that the Iranian government's decision for natural gas price liberalization has the adverse effects on economic growth and policy makers should be cautious in doing this policy. - Highlights: • Iran has been considered as a major natural gas producer in the world. • This paper examines the relationship between gas consumption and growth in Iran. • Positive impact of gas consumption on growth has been obtained. • The paper finds that gas consumption and income reinforce each other in Iran. • Natural gas price has also negative and significant impact on natural gas consumption in Iran

  4. 78 FR 19696 - Orders Granting Authority To Import and Export Natural Gas, To Import Liquefied Natural Gas, To...

    Science.gov (United States)

    2013-04-02

    ... DEPARTMENT OF ENERGY Orders Granting Authority To Import and Export Natural Gas, To Import Liquefied Natural Gas, To Export Liquefied Natural Gas and Vacating Prior Authority During December 2012 FE... granting authority to import and export natural gas and liquefied natural gas and vacating prior [[Page...

  5. Natural product mode of action (MOA) studies: a link between natural and synthetic worlds.

    Science.gov (United States)

    La Clair, James J

    2010-07-01

    In our understanding of matter, natural products deliver plots that would stun even the best productions of the legendary filmmaker, Sergio Leone. While every decade heralds a new genre of film (as well as avenues of small-molecule discovery), natural products and their "untamed prehistoric" plots continue to dazzle the fields of biotechnology, drug discovery, fragrances, food additives and agrochemistry. This review provides an abridged synopsis of the modes of natural product action discovered within the last decade and the tools and methods used in their discovery. Their stories are united in a common theme that unveils one of the more vital aspects of chemical biological research:understanding the global activity of Nature's arsenal of secondary metabolites.

  6. Natural radioactivity in the environment

    Energy Technology Data Exchange (ETDEWEB)

    Petr, I [Ceske Vysoke Uceni Technicke, Prague (Czechoslovakia). Fakulta Jaderna a Fysikalne Inzenyrska

    1980-01-01

    The effects were analyzed of natural radionuclides and cosmic radiation on radiation burden in man. The contents are shown of natural radionuclides in the earth crust, water, atmosphere, food chain and human organism. Using the data, the annual doses from natural sources to the gonads (1025 ..mu..Sv/yr) and to the bone marrow (986 ..mu..Sv) are estimated.

  7. Two criticisms of natural theology

    Directory of Open Access Journals (Sweden)

    Błażej Gębura

    2014-01-01

    Full Text Available The article aims at considering two general criticisms often formulated against the natural theology. First criticism is based on the thesis that the conclusions of the natural theology are not adequate with the religious beliefs of non-philosophers. It is widely known as opposition between God of Religion and God of Philosophers. One can find that argument in the writings of Blaise Pascal. I’m arguing for the thesis, that the natural theologian cannot fulfill the criteria given by the proponents of this argument. This is because the argument of the natural theology cannot contains the premises taken from the Revelation. If the argument of the natural theology would contain the premises taken from the Revelation, then it would be the argument of religion. But philosopher of religion (natural theologian can’t do this, if he wants to formulate an philosophical argument. The second criticism is based on the notion of a rational person. In the light of this argument, the natural theology is successful only, if every rational person will accept the conclusion “God exist”. I’m trying to show that there is no philosophical argument that can guarantee it’s acceptance by some rational persons. The acceptance of the conclusion of the argument of the natural theology is a matter of personal decision. There is no logical argument, which can “force” rational persons (rational subjects to accept it’s conclusion. But if this is true, the arguments for the existence of God are no worse than other philosophical arguments.

  8. Naturalness, value systems and perception of risk

    International Nuclear Information System (INIS)

    Drottz Sjoberg, B.M.

    1998-01-01

    Full text of publication follows: what is natural? And what is Nature? Are perceptions of Nature and naturalness related to perceptions of risk? This paper focuses on these aspects based on results from a Swedish representative sample (N=731), where subjects indicated e.g. the degree of naturalness of various phenomena, their views of nature, and personal life values, as well as perceptions of risk in specified contexts. The results showed a tendency to perceive as natural the phenomenon which is positively valued, i.e. what is natural is also good or desirable. Further, there were weak correlations between perceived naturalness and indicators of technological optimism, possibly indicating that persons with a more generous view of what is natural also more easily might accept change and outcomes due to human intelligence and activity. The construct of 'tampering with nature' has previously been shown to be one good predictor of perceived risk. The respondents also rated their agreement with items aimed to reflect the four 'views of nature' as suggested by Cultural Theory, i.e. nature as robust, capricious, tolerant and fragile. Nature was foremost perceived as fragile, but the main result clearly revealed that peoples' views of nature were complex and most often involved several of the suggested categories. The discussion focuses on the possible implications on environmental concern and risk perception given that Nature would develop into an undesirable type of locality. (author)

  9. Greenland and Natural Resources

    DEFF Research Database (Denmark)

    Lyck, Lise

    Greenland policy can delay and maybe change the future of the forecasted development of the use of natural resources. This book is relevant for anyone interested in Greenland in general and the development of Greenland both politically and economically and in relation natural resources....

  10. Diagrams of natural deductions

    Energy Technology Data Exchange (ETDEWEB)

    Popov, S V

    1982-01-01

    The concept of natural deductions was investigated by the author in his analysis of the complexity of deductions in propositional computations (1975). Here some natural deduction systems are considered, and an analytical procedure proposed which results in a deduction diagram for each system. Each diagram takes the form of an orientated, charge graph, features of which can be used to establish the equivalence of classes of deductions. For each of the natural deduction systems considered, a system of equivalent transformation schemes is derived, which is complete with respect to the given definition of equivalence. 2 references.

  11. Resfriamento rápido e armazenamento de caquis (Diospyrus kaki, L., cv. Fuyu, em condições de atmosfera refrigerada e modificada Fast cooling and storage of kakis (Diospyrus kaki, L., cv. Fuyu, in conditions of refrigerated atmosphere and modified

    Directory of Open Access Journals (Sweden)

    Valdecir Carlos Ferri

    2004-04-01

    Full Text Available Para aumentar o período de conservação após a colheita de caquis, da cultivar Fuyu, dois sistemas de armazenamento foram estudados: atmosfera refrigerada (AR e atmosfera modificada (AM. As frutas foram separadas em dois lotes: 1º resfriamento rápido a 0ºC até que a polpa atingisse 10ºC e, então, armazenadas em AR a 10±0,5ºC e 90±5% UR; 2º resfriamento rápido a 0ºC até que a polpa atingisse 0,5ºC, para serem armazenadas em condições de AR a 0±0,5ºC e 90±5% de UR e em AM com filme PEBD 80mim a 0±0,5ºC e 90±5% UR. Neste sistema (AM, também se testou o uso de sachet contendo 1g de permanganato de potássio. Através dos resultados obtidos, observou-se que, para o armazenamento de caquis 'Fuyu', por períodos de até 30 dias, a temperatura de 10ºC é eficiente e, para períodos superiores, o emprego de filmes de polietileno de baixa densidade de 80mim, associado com a absorção do etileno, é o mais aficaz. O armazenamento em AR a 0±0,5ºC e 90±5% UR não foi eficiente na conservação dos caquis.In order to increase the conservation period of kakis cultivar Fuyu after harvest, two storage systems were studied: refrigerated atmosphere (RA and modified atmosphere (MA. The fruits were separated in two groups: 1 rapid cooling at 0 ºC until the pulp reached 10ºC and, then stored in RA to 10±5 ºC and 90±5% RH; 2 rapid cooling at 0 ºC until the pulp reached 0,5 ºC and, then stored in RA to 0±0,5 ºC and 90±5% RH; and in MA with LDPE film 80mum 0±0.5ºC and 90±5% RH. In the systems (MA, also the sachet containing 1 g of potassium permanganate were tested. Through the obtained results it was observed that for the storage of kakis 'Fuyu', for periods until 30 days, the temperature of 10 ºC is efficient and, for longer periods the use of films of polyethylene of low density (LPDE of 80mum, associated with the absorption of the ethylene is also efficient. The storage in RA at 0±0,5 ºC and 90±5% RH was not efficient

  12. Naturally-occurring alpha activity

    Energy Technology Data Exchange (ETDEWEB)

    Mayneord, W V

    1960-12-01

    In view of the difficulties of assessing the significance of man-made radioactivity it is important to study for comparison the background of natural radioactivity against which the human race has evolved and lives. It is also important to define the present levels of activity so that it will be possible to detect and study as quickly as possible any changes which may occur owing to the release into the environment of new radioactive materials. Moreover, by the study of the behaviour of natural radioactivity light may be shed upon that of the artificially produced isotopes and a number of analogies traced between the two groups. These concepts have led to studies of naturally-occurring radioactive materials alongside a programme of research into fission products in food, water and air, as well as studies of the metabolism of both sets of materials in the human body. Since the last report there has been a useful increase in our knowledge of natural radioactivity in the biosphere, and its levels relative to the new man-made activities. These studies have necessitated technical developments, particularly in the methods of measuring and identifying alpha-ray emitters, to which group many of the more important natural radioactive materials belong.

  13. Journal of East African Natural History

    African Journals Online (AJOL)

    The Journal of East African Natural History is published jointly by the East Africa Natural History Society and the National Museums of Kenya. The Journal publishes papers and notes in the field of natural history, broadly defined as the study of organisms in their natural state, relevant to the eastern African region.

  14. Imagining Nature during Music Listening

    DEFF Research Database (Denmark)

    Bonde, Lars Ole; Beck, Bolette Daniels

    2018-01-01

    Nature, its delights and horrors, its creatures, its challenges and affordances play an underrated role in receptive music therapy, especially Guided Imagery and Music (GIM). In general, people from Western cultures are challenged in their mostly recreational relationship with nature, while ancient...... and traditional cultures worship nature as a place of holiness and wholeness. In GIM, a client or a group listens to music in a relaxed state and multi-modal imagery is evoked and supported by the music. The imagery is shared with the guide/therapist. This chapter will focus on ‘nature imagery’ in GIM through...... a primarily qualitative, exploratory study....

  15. Natural gas: redistributing the economic surplus

    International Nuclear Information System (INIS)

    Oliveira, A. de; Pinto Junior, H.Q.

    1990-01-01

    The natural gas has a limited role in the Brazilian energy balance. This role in industrial countries and some developing countries is much more important. Historically this contrasting situation can be explained by the limited natural gas reserves Brazil used to have. Since the oil crisis however the Brazilian natural gas reserves increased substantially without a similar increase in the role of natural gas in the energy balance. The existing institutional arrangement generates a struggle for the economic rent generated by natural gas production and consumption that seems to be at the core of this question. Our paper estimates the economic rent generated by natural gas in Brazil and its distribution among producers and consumers: it points toward a new institutional arrangement that could arguably, generate a new role for the natural gas in the Brazilian energy balance. (author)

  16. Study of the ortho-positron annihilation process in zeolite Y; Estudio del proceso de aniquilacion de ortopositronio en zeolita Y

    Energy Technology Data Exchange (ETDEWEB)

    Alvarado D, M E

    2010-07-01

    For several years a great interest has existed for the study of the natural and synthetic zeolites due to its properties. The porosity, one of their main characteristics allows that these materials are used as molecular sieves, catalysts, gases drying, etc. In order to investigating the porosity and other zeolite properties one carries out the study of the process of positron annihilation lifetime spectroscopy (Pals). This is a technique that provides information about the size and the pores form since is highly sensitive to the free volume and the superficial area of those porous materials as the zeolites. The study began with the elaboration of zeolite Y tablets in a hydraulic press where different pressures (from 0 to 1.26 GPa) and masses (70, 80 and 100 mg) were proven to obtain the estimate porosity of each tablet. A graph was elaborated and the effect of the mass and pressure with regard to the zeolite porosity was analyzed. Later on, the powder and tablets of 70 mg were characterized by means of X-ray diffraction (the glass size, interplanar distance, length and the volume of the unitary cell); scanning electron microscopy (the particles size and morphology); thermo gravimetric analysis (dehydration temperature and the stability up to 700 C) and the Brunauer Emmett Teller method (specific area). After the zeolite Y tablets characterization was carried out the positron annihilation process by means of Pals where its free volume of zeolite Y was analyzed, which includes to the structural cavities and the interparticle volume. The powdered zeolite was analyzed to different experimental conditions (preparation of the sample and the Pals equipment) to obtain the optimal conditions (a window with a time of 400 ns and a enlarged energy window) of analysis. On the other hand, the tablets were analyzed under optimal conditions to obtain the four components of time and intensity ({tau}, {Iota}), result of the different ways of positrons annihilation in the zeolite

  17. 21 CFR 582.30 - Natural substances used in conjunction with spices and other natural seasonings and flavorings.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Natural substances used in conjunction with spices... with spices and other natural seasonings and flavorings. Natural substances used in conjunction with spices and other natural seasonings and flavorings that are generally recognized as safe for their...

  18. The nature-disorder paradox: A perceptual study on how nature is disorderly yet aesthetically preferred.

    Science.gov (United States)

    Kotabe, Hiroki P; Kardan, Omid; Berman, Marc G

    2017-08-01

    Natural environments have powerful aesthetic appeal linked to their capacity for psychological restoration. In contrast, disorderly environments are aesthetically aversive, and have various detrimental psychological effects. But in our research, we have repeatedly found that natural environments are perceptually disorderly. What could explain this paradox? We present 3 competing hypotheses: the aesthetic preference for naturalness is more powerful than the aesthetic aversion to disorder (the nature-trumps-disorder hypothesis ); disorder is trivial to aesthetic preference in natural contexts (the harmless-disorder hypothesis ); and disorder is aesthetically preferred in natural contexts (the beneficial-disorder hypothesis ). Utilizing novel methods of perceptual study and diverse stimuli, we rule in the nature-trumps-disorder hypothesis and rule out the harmless-disorder and beneficial-disorder hypotheses. In examining perceptual mechanisms, we find evidence that high-level scene semantics are both necessary and sufficient for the nature-trumps-disorder effect. Necessity is evidenced by the effect disappearing in experiments utilizing only low-level visual stimuli (i.e., where scene semantics have been removed) and experiments utilizing a rapid-scene-presentation procedure that obscures scene semantics. Sufficiency is evidenced by the effect reappearing in experiments utilizing noun stimuli which remove low-level visual features. Furthermore, we present evidence that the interaction of scene semantics with low-level visual features amplifies the nature-trumps-disorder effect-the effect is weaker both when statistically adjusting for quantified low-level visual features and when using noun stimuli which remove low-level visual features. These results have implications for psychological theories bearing on the joint influence of low- and high-level perceptual inputs on affect and cognition, as well as for aesthetic design. (PsycINFO Database Record (c) 2017 APA, all

  19. Canadian natural gas winter 2005-06 outlook

    International Nuclear Information System (INIS)

    2005-11-01

    An outline of the Canadian natural gas commodity market was presented along with an outlook for Canadian natural gas supply and prices for the winter heating season of 2005-2006. In Canada, the level of natural gas production is much higher than domestic consumption. In 2004, Canadian natural gas production was 16.9 billion cubic feet per day (Bcf/d), while domestic consumption was much lower at 8.2 Bcf/d. The United States, whose natural gas consumption is higher than production, imported about 16 per cent of its natural gas supply from Canada and 3 per cent from other countries via liquefied natural gas imports. Canadian natural gas exports to the United States in 2004 was 8.7 Bcf/d, representing 51 per cent of Canada's production. In Canada, the most important natural gas commodity markets that determine natural gas commodity prices include the intra-Alberta market and the market at the Dawn, Ontario natural gas hub. A well connected pipeline infrastructure connects the natural gas commodity markets in Canada and the United States, allowing supply and demand fundamentals to be transferred across all markets. As such, the integrated natural gas markets in both countries influence the demand, supply and price of natural gas. Canadian natural gas production doubled from 7 to 16.6 Bcf/d between 1986 and 2001. However, in the past 3 years, production from western Canada has leveled out despite record high drilling activity. This can be attributed to declining conventional reserves and the need to find new natural gas in smaller and lower-quality reservoirs. The combination of steady demand growth with slow supply growth has resulted in high natural gas prices since the beginning of 2004. In particular, hurricane damage in August 2005 disrupted natural gas production in the Gulf of Mexico's offshore producing region, shutting-in nearly 9 Bcf/d at the height of damage. This paper summarized some of the key factors that influence natural gas market and prices, with

  20. 77 FR 31838 - Notice of Orders Granting Authority to Import and Export Natural Gas and Liquefied Natural Gas...

    Science.gov (United States)

    2012-05-30

    ... Granting Authority to Import and Export Natural Gas and Liquefied Natural Gas During April 2012 AGENCY... International, LLC....... 12-33-NG Phillips 66 Company 12-34-NG Northwest Natural Gas Company 12-41-NG Sequent... authority to import and export natural gas and liquefied natural gas. These Orders are summarized in the...

  1. 78 FR 38309 - Northern Natural Gas Company; Southern Natural Gas Company, L.L.C.; Florida Gas Transmission...

    Science.gov (United States)

    2013-06-26

    ... Natural Gas Company; Southern Natural Gas Company, L.L.C.; Florida Gas Transmission Company, LLC; Notice of Application Take notice that on June 4, 2013, Northern Natural Gas Company (Northern), 1111 South 103rd Street, Omaha, Nebraska 68124; on behalf of itself, Southern Natural Gas Company, L.L.C., and...

  2. Natural gas for vehicles (NGV)

    International Nuclear Information System (INIS)

    Prieur, A.

    2006-01-01

    Following a decade-long upsurge in the use of natural gas in the energy sector (heating and especially electricity), new outlets for natural gas are being developed in the transport sector. For countries endowed with substantial local resources, development in this sector can help reduce oil dependence. In addition, natural gas is often used to reduce pollution, particularly in cities. (author)

  3. Provincialising Nature

    DEFF Research Database (Denmark)

    Provincialising Nature: Multidisciplinary Approaches to the Politics of the Environment in Latin America offers a timely analysis of some of the crucial challenges, contradictions and promises within current environmental discourses and practices in the region. This book shows both challenging...... scenarios and original perspectives that have emerged in Latin America in relation to the globally urgent issues of climate change and the environmental crisis. Two interconnected analytical frameworks guide the discussions in the book: the relationship between nature, knowledge and identity and their role...... in understanding recent and current practices of climate change and environmental policy. The different chapters in this volume contribute to this debate by offering multidisciplinary perspectives on particular aspects of these two frameworks and through a multidirectional outlook that links the local, national...

  4. Natural User Interfaces

    OpenAIRE

    Câmara , António

    2011-01-01

    Dissertação de Mestrado em Engenharia Informática apresentada à Faculdade de Ciências e Tecnologia da Universidade de Coimbra This project’s main subject are Natural User Interfaces. These interfaces’ main purpose is to allow the user to interact with computer systems in a more direct and natural way. The popularization of touch and gesture devices in the last few years has allowed for them to become increasingly common and today we are experiencing a transition of interface p...

  5. The Effect of Gamma Irradiation on the Mechanical Properties of vulcanized Natural Rubber and Natural Rubber-Polyethylene Blends

    International Nuclear Information System (INIS)

    Sudradjat Iskandar

    2008-01-01

    To enhance the quality of vulcanized natural rubber and natural rubber-polyethylene blends, gamma irradiation has been done. The compound of natural rubber and natural rubber-polyethylene blends made by using roll mill machine. The mixed materials were antioxidant, anti ozon, plasticizer and vulcanisator. The natural rubber and natural rubber-polyethylene blends compound were vulcanizer and made a slab (film of sample) using hot and could press machine. The slabs produced were then gamma irradiated at irradiation dose of 75, 150 and 300 kGy. Before and after irradiation, the slab were characterized using strograph R1 machine. The results showed that the modulus 300 and hardness of vulcanized natural rubber and natural rubber-polyethylene blends were increasing; the tensile strength and tear strength were increasing to maximum level then decreasing with gamma irradiation, while the elongation at break was decreasing. The maximum tensile strength of vulcanized natural rubber and natural rubber-polyethylene blends were found at irradiation dose of 75 kGy. At the irradiation dose of 75 kGy, the tensile strength of vulcanized natural rubber increased from 17.6 MN/m 2 to 21.2 MN/m 2 , while the tensile strength of vulcanized natural rubber-polyethylene blends increased slightly from 18.7 MN/m 2 to 19.4 MN/m 2 . (author)

  6. 75 FR 70350 - Liberty Natural Gas LLC, Liberty Liquefied Natural Gas (LNG) Deepwater Port License Application

    Science.gov (United States)

    2010-11-17

    ... DEPARTMENT OF TRANSPORTATION Maritime Administration [USCG-2010-0993] Liberty Natural Gas LLC, Liberty Liquefied Natural Gas (LNG) Deepwater Port License Application AGENCY: Maritime Administration... announce they have received an application for the licensing of a natural gas deepwater port and the...

  7. 76 FR 4417 - Liberty Natural Gas LLC, Liberty Liquefied Natural Gas (LNG) Deepwater Port License Application

    Science.gov (United States)

    2011-01-25

    ... DEPARTMENT OF TRANSPORTATION Maritime Administration [USCG-2010-0993] Liberty Natural Gas LLC, Liberty Liquefied Natural Gas (LNG) Deepwater Port License Application AGENCY: Maritime Administration... application describes an offshore natural gas deepwater port facility that would be located approximately 16.2...

  8. Organobentonita como sustituto de negro de carbono en formulaciones de caucho

    Directory of Open Access Journals (Sweden)

    López Manchado, M. A.

    2004-04-01

    Full Text Available Rubber compounds based on natural rubber reinforced with ammonium salt modified bentonite have been prepared and characterized. It pretends to evaluate the possibility of using these white fillers as substitute of carbon black in natural rubber compounds. Vulcametric curves show that the organoclay and carbon black accelerate the vulcanization reaction and, furthermore, give rise to a marked increase in the torque. However, it is of interest to point out that these effects are more marked in the case of the organoclay. In addition, the mechanical characterization show the strong reinforcing effect of both fillers, but this effect is newly more sensible when the organoclay is added to the NR. It is worthy to note that the mechanical properties of 10% organoclay-NR nanocomposite are comparable to the 40 phr carbon black filled compound.

    Se han preparado y caracterizado nanocomposites de caucho natural reforzados con bentonita modificada orgánicamente con una sal de amonio. Se pretende evaluar la posibilidad de utilizar estas cargas claras como sustitutos del negro de carbono en las formulaciones de caucho natural. Las curvas de vulcanización muestran que tanto la bentonita organofilizada como el negro de carbono aceleran la reacción de vulcanización y además, dan lugar a un considerable incremento en el torque. No obstante, es interesante destacar que estos efectos son más marcados en el caso de la organobentonita. Por su parte, la caracterización mecánica muestra el fuerte efecto reforzante de ambas cargas, si bien este efecto es nuevamente más acusado en presencia de la organobentonita. Es importante señalar que las propiedades mecánicas del nanocomposite reforzado con 10 partes de organobentonita son similares a las del composite con 40 partes de negro de carbono.

  9. Globalization of the Natural Gas Industry

    International Nuclear Information System (INIS)

    Burns, RJ.

    1996-01-01

    This document deals with the foreseeable evolution of natural gas demand in the next 15 years. Natural gas consumption is growing faster than any other fossil fuel and, according to ENRON, the natural consumption growth will continue. The environmental aspect of natural gas use for power generation is presented, showing that gas use reduces pollution emissions (when compared with coal). On top of that, it appears that the conversion efficiency of gas is much higher than the conversion efficiency of coal steam. Eventually, natural gas resources should meet energy demand for decades. (TEC)

  10. Contaminación enteroparasitaria de lechugas expendidas en mercados del estado Lara. Venezuela

    OpenAIRE

    TRAVIEZO-VALLES, LUIS; DÁVILA, JUAN; RODRÍGUEZ, RICARDO; PERDOMO, OMAIRA; PÉREZ, JOSÉ

    2004-01-01

    Para determinar la contaminación de lechugas con enteroparásitos, se analizaron 100 muestras (50 lechuga americana y 50 lechuga romana) cultivadas en tres lugares distintos, Timotes y Bailadores (estado Mérida) y Chejendé (estado Trujillo) y expendidas en cuatro mercados diferentes del estado Lara: Terepaima, Cabudare, Las Trinitarias y Central. Las lechugas fueron procesadas según la técnica de Álvarez et al, modificada, detectando contaminación en el 29% de las muestras (16 LA y 13 LR) iden...

  11. Producción de proteínas recombinantes de Plasmodium falciparum en Escherichia coli

    Directory of Open Access Journals (Sweden)

    Ángela Patricia Guerra

    2016-04-01

    Conclusión. El uso de cepas de E. coli genéticamente modificadas fue fundamental para alcanzar altos niveles de expresión de las cuatro proteínas recombinantes evaluadas y permitió obtener dos de ellas en forma soluble. La estrategia utilizada permitió expresar cuatro proteínas recombinantes de P. falciparum en cantidad suficiente para inmunizar ratones y producir anticuerpos policlonales y, además, conservar proteína pura y soluble de dos de ellas para ensayos futuros.

  12. Oral vaccines against diarrhea associated with enteropathogenic Escherichia coli strains based on genetically modified Bacillus subtilis strains

    OpenAIRE

    Wilson Barros Luiz

    2010-01-01

    O objetivo deste trabalho foi a construção de linhagens geneticamente modificadas de B. subtilis capazes de expressar porções de intimina, principal componente envolvido na capacidade de colonização de linhagens enteropatogênicas de Escherichia coli (EPEC), como estratégia vacinal de administração oral contra diarréias infecciosas. As vacinas desenvolvidas empregaram cinco regiões da intimina de EPEC e linhagens de B. subtilis capazes de expressar e acumular proteínas recombinantes no citopla...

  13. Retenção e degradação de 14C-glifosato e remobilização dos seus resíduos ligados em diferentes classes de solos

    OpenAIRE

    Sayonara Andrade do Couto Moreno Arantes

    2007-01-01

    O glifosato é um dos herbicidas mais consumidos no Brasil e com perspectivas de aumento deste consumo, diante da expansão do plantio direto e do plantio de culturas geneticamente modificadas com resistência a esse herbicida. Porém, pesquisas com esta molécula são ainda incipientes em solos de clima tropical. Nesse contexto, esta pesquisa objetivou gerar dados para uma melhor compreensão do comportamento ambiental desta molécula. Com este intuito, foram realizados ensaios laboratoriais com um ...

  14. Mobbing: assédio moral em contexto de enfermagem

    OpenAIRE

    Carvalho, Guilhermina

    2010-01-01

    Este estudo pretende avaliar o impacto do mobbing (assédio moral ou assédio psicológico) em contexto de enfermagem relativamente à sua frequência, intensidade e efeito. Com isto, pretendeu-se dar visibilidade ao tema, melhor documentá-lo e por conseguinte, melhor compreendê-lo. Um dos objectivos deste trabalho consistiu em traduzir, adaptar e validar uma escala: a LIPT 60 (Leymann Inventory of Psychological Terrorization - versão modificada) a uma população portuguesa de enfermeiros em contex...

  15. Nota sobre culicídeos adultos coletados na região sul do Brasil

    Directory of Open Access Journals (Sweden)

    Barbosa Orlando Carlos

    1993-01-01

    Full Text Available São apresentados os resultados obtidos de coletas de mosquitos, com armadilha luminosa de Shannon, às margens de uma mata modificada, e armadilhas de Falcão na mesma mata e em ecótopos extra-florestais, no Município de Terra Boa, Estado do Paraná, Brasil, de setembro de 1988 a abril de 1990. Verificou-se a prevalência das espécies de culicídeos e compararam-se os dois métodos de coletas.

  16. Informes clínicos breves

    OpenAIRE

    Facultad de Medicina Revista

    1996-01-01

    Procedimientos mayores en cirugía general, Hospital San Juan de Dios. 511 casos / síndrome de pinzamiento de hombro: Tratamiento con acromioplastia de neer modificada  / Fascitis necrotizante / Colangitis aguda / Infusión continua de alfentanyl vs. anestesia general, inhalatoria convencional en varicosafenectomía / ecografía doppler en la evaluación de la hidronefrosis del niño / Analgesia epidural en el trabajo de parto: Comparación de dos técnicas: infusión continua vs. refuerzos / Manual d...

  17. Nature/culture/seawater.

    Science.gov (United States)

    Helmreich, Stefan

    2011-01-01

    Seawater has occupied an ambiguous place in anthropological categories of "nature" and "culture." Seawater as nature appears as potentiality of form and uncontainable flux; it moves faster than culture - with culture frequently figured through land-based metaphors - even as culture seeks to channel water's (nature's) flow. Seawater as culture manifests as a medium of pleasure, sustenance, travel, disaster. I argue that, although seawater's qualities in early anthropology were portrayed impressionistically, today technical, scientific descriptions of water's form prevail. For example, processes of globalization - which may also be called "oceanization" - are often described as "currents," "flows," and "circulations." Examining sea-set ethnography, maritime anthropologies, and contemporary social theory, I propose that seawater has operated as a “theory machine” for generating insights about human cultural organization. I develop this argument with ethnography from the Sargasso Sea and in the Sea Islands. I conclude with a critique of appeals to water's form in social theory.

  18. APPLICATION OF NATURAL TRANSFORM IN CRYPTOGRAPHY

    OpenAIRE

    Chindhe, Anil Dhondiram; Kiwne, Sakharam

    2017-01-01

    Abstaract−The newly defined integral transform ”Natural transform” has many application in the field of science and engineering.In this paper we described the application of Natural transform to Cryptography.This provide the algorithm for cryptography in which we use the natural transform of the exponential function for encryption of the plain text and corresponding inverse natural transform for decryption

  19. Living in cities, naturally.

    Science.gov (United States)

    Hartig, Terry; Kahn, Peter H

    2016-05-20

    Natural features, settings, and processes in urban areas can help to reduce stress associated with urban life. In this and other ways, public health benefits from, street trees, green roofs, community gardens, parks and open spaces, and extensive connective pathways for walking and biking. Such urban design provisions can also yield ecological benefits, not only directly but also through the role they play in shaping attitudes toward the environment and environmental protection. Knowledge of the psychological benefits of nature experience supports efforts to better integrate nature into the architecture, infrastructure, and public spaces of urban areas. Copyright © 2016, American Association for the Advancement of Science.

  20. Anthropologie de la nature

    OpenAIRE

    Descola, Philippe

    2010-01-01

    En apparence, l’anthropologie de la nature est une sorte d’oxymore puisque, depuis plusieurs siècles en Occident, la nature se caractérise par l’absence de l’homme, et l’homme par ce qu’il a su surmonter de naturel en lui. Mais la nature n’existe pas comme une sphère de réalités autonomes pour tous les peuples. En postulant une distribution universelle des humains et des non-humains dans deux domaines ontologiques séparés, nous sommes bien mal armés pour analyser tous ces systèmes d’objectiva...