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Search Results: 1 - 10 of 72161 matches for " José Alfredo PIETROGIOVANNA BRONCA "
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DETERMINACIóN DE LA DOSIS óPTIMA DE REACTIVO FENTON EN UN TRATAMIENTO DE LIXIVIADOS POR FENTON-ADSORCIóN
Roger Iván MéNDEZ NOVELO,José Alfredo PIETROGIOVANNA BRONCA,Beatriz SANTOS OCAMPO,María Rosa SAURI RIANCHO
Revista internacional de contaminación ambiental , 2010,
Abstract: Los lixiviados son el resultado de la percolación de líquidos a través de los desechos sólidos en proceso de estabilización. La complejidad de su tratamiento se debe a que su composición es altamente tóxica y variable. Lo anterior y el suelo altamente permeable de la península de Yucatán, representan un alto peligro a la salud. Se ensayó un tratamiento de oxidación tipo Fenton-adsorción con el que se obtuvieron mejores resultados que con otros tratamientos fisicoquímicos o biológicos reportados en la literatura. El proceso Fenton consiste en tratar la carga contaminante con una combinación de H2O2 y FeSO4 en condiciones ácidas. Se evaluó si la filtración de los lodos producidos durante el proceso Fenton es un proceso más eficiente que la sedimentación. Se determinó el tiempo de contacto óptimo de la oxidación Fenton, así como la dosis óptima de los reactivos usados en función de la DQO del lixiviado, mediante la determinación de las mejores relaciones [Fe2+]/[H2O2] y [DQO]/[H2O2]. Después de optimizar el proceso, se filtraron las muestras oxidadas y se ensayó la adsorción mediante columnas empacadas con carbón activado granular. Se concluyó que el lodo generado por el proceso Fenton se remueve más eficientemente mediante filtración que por sedimentación. Los tiempos de contacto óptimos fueron de 5 min para la remoción de la DQO y una hora para la remoción de color, tiempo elegido para proteger el carbón activado. Las mejores relaciones para [Fe2+]/[H2O2] y [DQO]/[H2O2] fueron 0.6 y 9, respectivamente. La eficiencia máxima de remoción después del proceso de adsorción fue de 98.9 % para la DQO y 100 % para el color. El índice de biodegradabilidad final alcanzado después de las pruebas de Fenton-adsorción fue de 0.24.
Determinación de la dosis óptima de reactivo Fenton en un tratamiento de lixiviados por Fenton-adsorción
MéNDEZ NOVELO, Roger Iván;PIETROGIOVANNA BRONCA, José Alfredo;SANTOS OCAMPO, Beatriz;SAURI RIANCHO, María Rosa;GIáCOMAN VALLEJOS, Germán;CASTILLO BORGES, Elba René;
Revista internacional de contaminación ambiental , 2010,
Abstract: leachates are formed as a result of the percolation of liquids, through the solid wastes in stabilization process. their composition is variable and highly toxic; therefore, leachates treatment is a complex task. due to the high permeability of the soil of the yucatán peninsula leachates represent a high risk to health. fenton type oxidation and adsorption treatment have been tested, and they have showed better results than other types of biological or physicochemical treatment. fenton process consists in treating the contaminant load with a combination of h2o2 and feso4 under acidic conditions. experiments were conducted in order to determine if filtration was better than the sedimentation of the sludges. the optimum contact time and the best relations [fe2+]/[h2o2] and [cod]/[h2o2] were determined. subsequently, the oxidized samples were filtered and the adsorption process was tested using two columns in series packed with activated carbon. it was concluded that the sludge generated by the fenton process was removed more efficiently through filtration than sedimentation. optimal contact times were 5 min for cod removal, and 1 hour for colour removal; process time was set to one hour in order to protect the activated carbon. the best relations for [fe2+]/[h2o2] and [cod]/[h2o2] were 0.6 and 9 respectively. the maximum removal efficiency after the adsorption process was 98.9% for cod and 100% for colour at zero time of the column. a final biodegradability index of 0.24 was reached after the fenton-adsorption tests.
Germinación y sobrevivencia de esclerocios de (Phymatotrichopsis omnivora) en respuesta a NaOCl y suelo con glucosa
Samaniego Gaxiola, José Alfredo;
Agricultura técnica en México , 2008,
Abstract: sclerotia of phymatotrichopsis omnivora can survive for 20 years in the soil; however, if sclerotia are exposed to chemical agents or microbial competition in soil, survival is reduced to few weeks. the objective of this research was to study the germination and survival of p. omnivore sclerotia, treated first with a solution of naocl and then exposed to microbiota competition in soil supplemented with dextrose. the experiments were carried out at 'la laguna' research station of the national research institute for forestry, agriculture and livestock under a completely random factorial design. sclerotia were immersed in 200, 500 and 3 000 ppm naocl solutions during 0.3, 1, 8, and 72 h. at two temperatures, 15-20 and 28 °c, afterwards were placed in soil added with 0.0, 0.125, 0.25 and 0.5 mg g-1 of dextrose during 14 days under saturated conditions at 28 °c. sclerotia immersed into a 3 000 ppm solution of naocl during 20 min showed 90% germination in sterile sand and pda and only 15% in non-sterile sand and pda. when sclerotia were germinated before being immersed in naocl, viability was 100% in all substrates utilized. survival of sclerotia decreased with the increase in the time of immersion, concentration of naocl, and concentration of dextrose added to the soil. sclerotia immersed during one hour or more in 1 000 ppm or higher of naocl solution and placed in soil with 0.25 or 0.5 mg g-1 of added dextrose showed a maximum survival of 20%. sclerotia survival was high in some treatments at 15-20 °c than in similar treatments at 28 °c, possible due to a protective effect of naocl on sclerotia exposed to soil microbiota enhanced by added dextrose.
Acceso oportuno y permanencia escolar de alumnos de 6 a 14 a?os en Sonora, 2003-2005
Flores Valdez, José Alfredo;
Región y sociedad , 2009,
Abstract: the concept of quality in education is better interpreted by analyzing its different dimensions, in particular by making judgments about the efficiency, pertinence, and equity of the system as a whole. this approach has been used in various studies of the educational system based on the analysis of academic results, understood as synonymous of educational efficiency, ignoring the important and basic issue of access to education. there is much to be done; a detailed analysis of education coverage by age and grade not only shows meaningful progress in sonora between 2003 and 2005, but also highlights the main problems. in this sense, the biggest weaknesses are timely access and permanence, the key to academic success in children aged 10-12 and 14, who are in the final stages of elementary and middle school. the challenge is to avoid the repetition of school grades in elementary school as a preventive measure to avoid desertion, another big problem in middle school.
La vuelta de Jesús a los discípulos. Los rostros de la parusía en el Cuarto Evangelio
NORATTO G,JOSé ALFREDO;
Theologica Xaveriana , 2008,
Abstract: this paper explores the richness of the theological and eschatological conceptions subtending the language of the parousia in the texts of the literary and theological tradition of the fourth gospel. its originality and novelty are represented by the way in which the different traditions referring to the second advent of the lord are articulated, with the intention of expliciting the different eschatological horizons and of grasping the enormous hermeneutical potential of ?ρχομαι in its epiphanic dimension, and its extension in implicit language represented mainly by the verbs of vision, knowledge and revelation, and the paradigmatic figure of the paraclete.
La vuelta de Jesús a los discípulos. Los rostros de la parusía en el Cuarto Evangelio A volta de Jesus aos discípulos. Os rostos da Parusia no Quarto Evangelho The return of Jesus to the disciples. The faces of the Parousia in the Fourth Gospel
JOSé ALFREDO NORATTO G
Theologica Xaveriana , 2008,
Abstract: Explora la riqueza de concepciones cristológicas y escatológicas subyacentes al lenguaje de la Parusía, en los textos de la tradición literaria y teológica del Cuarto Evangelio. Su originalidad y novedad están representadas por la forma como se han articulado las distintas referencias a la segunda venida del Se or, con la intención de explicitar los distintos horizontes escatológicos y captar el enorme potencial hermenéutico de ρχομαι en su dimensión epifánica, y su extensión en el lenguaje implícito, representado especialmente por los verbos de visión, conocimiento y revelación, y la paradigmática figura del Paráclito. Neste artigo explora-se a variedade de concep es cristológicas e escatológicas, que saem ao linguagem da Parusia nos textos, da tradi o literária e teológica do quarto evangelho. Sua originalidade e novidade est o representadas pela maneira como se tem unido as diversas referências, á segunda volta do senhor com a inten o de expor os diferentes horizontes escatológicos e entender o grande potencial hermenêutico de ρχομαι na sua dimens o epifánica e sua inten o na linguagem explicita e representada especialmente pelos verbos de vis o, conhecimento e revela o, junto á paradigmática figura do Paráclito. This paper explores the richness of the theological and eschatological conceptions subtending the language of the Parousia in the texts of the literary and theological tradition of the Fourth Gospel. Its originality and novelty are represented by the way in which the different traditions referring to the second advent of the Lord are articulated, with the intention of expliciting the different eschatological horizons and of grasping the enormous hermeneutical potential of ρχομαι in its epiphanic dimension, and its extension in implicit language represented mainly by the verbs of vision, knowledge and revelation, and the paradigmatic figure of the Paraclete.
Herejías y disidencias en la frontera de Rioverde: los Barragán en el siglo XVIII
Rangel Silva, José Alfredo
Revista de Indias , 2010,
Abstract: Thanks to knowledge acquired as a bandit and mule driver, the Spaniard, Gabriel Fernández de Lima, alias Rufino Barragán, amassed a great fortune after settling in Rioverde, a war zone populated since the end of the 17th century by Spanish minor noblemen. His heretical opinions and dissolute lifestyle were scrutinised by the Inquisition, who also had problems with his son and grandson. The documentation gathered together in different archives allows us to reconstruct the lives of the members of this singular family of pioneers in the North, known for their rather unorthodox behaviour. Gracias a los conocimientos adquiridos como bandido y arriero, el espa ol Gabriel Fernández de Lima, alias Rufino Barragán, amasó una gran fortuna tras instalarse en Rioverde, una zona de guerra poblada desde finales del siglo XVII por hidalgos espa oles. Sus opiniones heréticas y vida licenciosa fueron analizadas por la Inquisición, quien también tuvo problemas con su hijo y nieto. La documentación reunida en diversos archivos permite reconstruir la vida de los integrantes de una singular familia de pioneros en el Norte, conocida por sus manifestaciones poco ortodoxas.
Economía y mercado en la minería tradicional mexicana, 1873-1929
Uribe Salas, José Alfredo
Revista de Indias , 2001,
Abstract: This article studies the behaviour of the Mexican traditional mining industry, with deep historical roots, in a world scenery determined by the two great depressions of 1873-1874 and 1929-1932. The modernization of the productive system is analyzed, together with the enterprise strategies to get round the pitfalls imposed by the international market of metals (cost/benefit) and the low propensity of the great silver and gold producting firms to widen the internal market. En este artículo de estudia el comportamiento de la industria minera tradicional mexicana, de hondas raíces históricas, en un escenario internacional marcado por dos grandes depresiones: la de 1873-1874 y la de 1929-1932. Se destaca la modernización del aparato productivo, y se analizan las estrategias empresariales para sortear los escollos impuestos por el mercado internacional de metales (costos/beneficios) y la baja propensión de las grandes empresas productoras de plata y oro a la ampliación del mercado interno.
Minería del cobre en el occidente del México prehispánico: un acercamiento historiográfico
Uribe Salas, José Alfredo
Revista de Indias , 1996,
Abstract: Ignorance of Tarascan metallurgical culture has caused untenable omissions, overstatements and historical errors of fact This historiographical essay calls attention to this metallurgical culture, which -within the Mesoamerican context- had an extensive knowledge of the work with metals, particularly copper and it alloys; this knowledge was superior to that of regions familiar with the work of native gold and silver. El desconocimiento de la cultura metalúrgica tarasca ha llevado a omisiones insostenibles, lo mismo que a afirmaciones desproporcionadas y a errores históricos. Este ensayo historiográfico insiste sobre la cultura metalúrgica tarasca, que se caracterizó, en el contexto mesoamericano, por el amplio conocimiento de los metales, particularmente en la confección de objetos de cobre y sus aleaciones, superior a aquellas regiones en donde se trabajaron metales nativos como el oro y la plata.
EDITORIAL
José Alfredo Aparicio
Psicología desde el Caribe , 2002,
Abstract:
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