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Search Results: 1 - 10 of 258193 matches for " José G.; Barrera-Vargas "
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Impregnación de platino y dimensión fractal en dos tipos de sólidos microporosos
Carriazo,José G.; Barrera-Vargas,Mario; Molina,Manuel F.;
Revista Ingenierías Universidad de Medellín , 2010,
Abstract: this research shows the modification of a zeolite y and a pillared clay (saponite) by impregnation with different platinum quantities (synthesis of pt catalysts). the solids were characterized about the chemical composition and texture. the textural characterization reveals important changes in the solids, showing that in the zeolitic catalysts microporosity is formed, whereas in the pillared clay the microporous structures are partially blocked. fractal dimension (by avnir-jaroniec method) indicates that the topographic features of the pillared clay surface are significantly affected due to the modification with platinum, probably as a consequence of platinum clusters formation.
Impregnación de platino y dimensión fractal en dos tipos de sólidos microporosos Platinum impregnation and fractal dimension on two types of micro-porous solids
José G. Carriazo,Mario Barrera-Vargas,Manuel F. Molina
Revista Ingenierías Universidad de Medellín , 2010,
Abstract: El presente trabajo muestra la modificación de una zeolita-Y y una arcilla pilarizada (tipo saponita) mediante impregnación con diferentes cargas de Pt (catalizadores a base de Pt). Los sólidos se caracterizaron en cuanto a su composición química y su textura. La caracterización textural revela cambios importantes en los sólidos, mostrando que se genera microporosidad en la serie de catalizadores zeolíticos y se bloquean las estructuras microporosas en la serie de catalizadores obtenidos a partir de la arcilla pilarizada. La determinación de la dimensión fractal (mediante el método de Avnir-Jaroniec) indica que la modificación con Pt afecta significativamente las características topográficas de la superficie de la arcilla pilarizada como consecuencia de la posible formación de agregados de Pt. This research shows the modification of a zeolite Y and a pillared clay (saponite) by impregnation with different platinum quantities (synthesis of Pt catalysts). The solids were characterized about the chemical composition and texture. The textural characterization reveals important changes in the solids, showing that in the zeolitic catalysts microporosity is formed, whereas in the pillared clay the microporous structures are partially blocked. Fractal dimension (by Avnir-Jaroniec method) indicates that the topographic features of the pillared clay surface are significantly affected due to the modification with platinum, probably as a consequence of platinum clusters formation.
EMPLEO DE DOS ARCILLAS NATURALES COLOMBIANAS EN LA ELIMINACIóN DE IONES METáLICOS EN SOLUCION ACUOSA
JOSé GREGORIO CARRIAZO,M. Barrera-Vargas,MARTHA J. SAAVEDRA
Scientia Et Technica , 2005,
Abstract: Se caracterizaron dos arcillas naturales mediante fisiadsorción de nitrógeno a 77K, análisis químico e intercambio catiónico y se emplearon en la eliminación de iones contaminantes (Cu2+, Al3+ y Fe3+) en solución. Las eficiencias en la eliminación de estos contaminantes indican la potencialidad de dichos materiales en procesos de descontaminación de aguas residuales.
Effect of Citric Acid, Phytase and Calcium Levels on the Calcium and Phosphorus Content in Egg: Yolk-Albumen and Shell, Yolk Color and Egg Quality in Diets of Laying Hens  [PDF]
Lily M. Vargas-Rodríguez, Jesús E. Morales-Barrera, José G. Herrera-Haro, Juan Antonio-Bautista, Roberto López-Pozos, David Hernández-Sánchez
Food and Nutrition Sciences (FNS) , 2016, DOI: 10.4236/fns.2016.714124
Abstract: To evaluate the effect of different levels of citric acid (CA) combined with phytase and calcium levels in the diets of laying hens on the calcium and phosphorus (P) contents of eggs: yolk-albumen and shell, yolk color and egg quality. A study was conducted with 24-week-old laying hens fed with a diet based on sorghum and soybean meal with 2.7 Mcal of EM/kg, 15% crude protein, 3.25% calcium and 0.25% available P. The levels of CA, phytase and calcium were 0%, 0.6% and 1.2%; 0 and 300 units of phytase (PHYU)/kg; and 3.0% and 3.25%, respectively. Phytase was added as an ingredient into to the diets, contributing 0.1% P and 0.3% calcium. A completely randomized factorial experiment was performed with a 3 × 2 × 2 design and 4 replications. The CA increased (P < 0.05) the P in the shell, and the combination of 1.2% CA, 300 PHYU phytase and 3.25% calcium increased (P < 0.05) the calcium in the eggshell. There was a CA × phytase × calcium interaction (P < 0.05) affecting egg yolk pigmentation; there were no differences in egg quality. It was concluded that adding CA to the diets of laying hens increases eggshell calcium content, and improves the phytase response. 1.2% CA × Phytase × 3.25% calcium significantly increases shell calcium by 0.56 g. Under the conditions of the present investigation, it would imply greater resistance of the eggs to be broken in the handling from the farm to the sales centers and consumer. Phytase interacts negatively with 0.6% CA at low calcium levels to degrade the yellow pigmentation of the yolk.
La nueva correlación de fuerzas para la gobernabilidad del Estado, el mercado y la sociedad
Vargas Hernández,José G;
Revista Venezolana de Economía y Ciencias Sociales , 2007,
Abstract: this article analyzes the problem of governance and the relations between the state, the market and society under the impact of globalization. it is argued that, despite the neoliberal tendency to limit and restrict the functions of the state, this continues to play a crucial role in regulating economic activity and it is of crucial importance to achieve an adequate equilibrium between the market, the private sector and the state
Sustentabilidad organizacional para el desarrollo ambiental y económico: el caso de micro empresas en San Sebastián del Sur
Vargas Hernández, José G.
Pecunia : Revista de la Facultad de Ciencias Económicas y Empresariales , 2010,
Abstract: En este trabajo se analiza la sustentabilidad de las organizaciones que realizan actividades de explotación del tule Thypha spp. en la Laguna de Zapotlán y su impacto en el desarrollo socioeconómico y ambiental de San Sebastián del Sur. La hipótesis inicial de trabajo se delimita con la consideración de que el escaso capital social de las organizaciones que realizan la explotación del tule Typha spp. de la Laguna de Zapotlán, limita la sustentabilidad del desarrollo, a pesar de que contribuye al sostenimiento de ingresos para más de 300 familias. El método de investigación empleado en el etnográfico, complementado con trabajo de campo apoyado con entrevistas informales, investigación documental y bibliográfica. La principal conclusión es que no existe un equilibrio entre la sustentabilidad de las organizaciones debido al escaso capital social y la sustentabilidad del desarrollo ambiental y económico.This paper analyzes sustainability and efficiency of organizations committed to the exploitation’ activities of tule Thypha spp at the Zapotlán’s Lake taking into consideration the socioeconomic and environmental impact in the municipalities of Gómez Farías and Zapotlán el Grande. The initial hypothesis departs from the consideration of the scarce social capital of organizations that limits development’s sustainability. The research method employed is the ethnographic complemented with field work supported by informal interviews, documental and bibliographic research. The outcomes of the application demonstrate that the drama of economic efficiency and sustainable development of micro-business is tied to constrain of social capital. The main conclusion is that it does not exists an equilibrium between the sustainability of organizations due to the scarcity of social capital and the sustainability of economic and environmental development. This finding has implications for the design and implementation of economic and social policies oriented towards the improvement of economic growth and sustainable development.
Cooperation and conflict among companies, communities, new social movements, and the role of the government. The case of Cerro de San Pedro
José G. Vargas- Hernández
HISTOReLo : Revista de Historia Regional y Local , 2009,
Abstract: The objective of this work is to analyze the relationships of cooperation and conflict among the mining company MSX; the communities of San Pedro, Soledad, and San Luis Potosí; the new social movements; and the three levels of government involved. The mining company began operations in a gold and silver open-pit mine with the support of officials from the local, state, and federal governments. The inhabitants of these communities, backed by environmental groups and non-government organizations argued that the project contaminated sources of fresh water, while also perturbing the environment and the region’s ecology. In this manner the article analyzes the impact, the social interaction, and the conflict among the distinct actors from a local and social-environmental perspective, after the historical contextualization of the subregion and the development of the mining industry is presented.
La organización y la estrategia: preferencias del estratega o imperativo para el éxito.
José G . Vargas Hernández
Revista de Administra??o Mackenzie , 2003,
Abstract: El objetivo de este trabajo es analizar la transformación de los procesos en la formulación de estrategias con relación a la evolución de la organización. Se determina que el pensamiento estratégico y la formulación de la estrategia ha sido privilegio único de la alta dirección hasta los 70’s, cuando el contexto se caracterizo por ser más o menos estable, en el que las ventajas comparativas eran suficientes para alcanzar el éxito de la organización a partir de la función del management tradicional. Sin embargo, al cambiar el medio ambiente competitivo por el fenómeno de La “turbulencia”, con mayor complejidad e incertidumbre, la alta dirección de l s organizaciones debe responder a crecientes demandas impuestas por las nuevas condiciones económicas y sociales. Y mediante un proceso continuo de innovación de todas las actividades de la empresa buscar ventajas competitivas sostenibles fundadas en elementos intangibles especialmente, en el “conocimiento”, El cual está interiorizado en todos los miembros de la organización. Por lo tanto, aunque la formulación de la estrategia sigue siendo facultad de la alta dirección, de alguna manera es influida por los demás integrantes de la organización.
THE ROLE OF GOVERNMENT IN ENHANCING ENTREPRENEURSHIP OF SMALL AND MEDIUM ENTERPRISES FOR ECONOMIC GROWTH
José G. Vargas Hernández
Revista da Micro e Pequena Empresa , 2011,
Abstract: The literature existing on entrepreneurship implicitly assumes that entrepreneurship and government and economic growth are positively related with each other and there is a positive correlation among them. However, few studies, whether theoretical or empirical, analyze such relation in an explicit manner. This paper aims to study the entrepreneurship notion and the barriers of entrepreneurship and mainly the role of government in enhancing entrepreneurship in the society.
STRATEGIC TRANSFORMATION PROCESSES IN ORGANIZATIONS
JOSé G. VARGAS HERNáNDEZ
Universitas Psychologica , 2003,
Abstract: The objective of this paper is to analyze the transformation processes in strategy formulation inrelation to the evolution of the organization. It is determined that strategic thinking and strategyformulation has been a unique privilege of top management until the 70’s when the context wascharacterized by being more or less stable, in which the comparative advantages were sufficient toachieve the organization’s success starting from the role of traditional management.However, when the competitive environment changes due to the turbulence phenomena, with morecomplexity and turbulence, top management of organizations must respond to increasing demandsimposed by the new social and economic conditions. And through a continuous process of innovationof all activities of the business to search for sustainable competitive advantages founded on intangibleelements, specifically on the “knowledge” which is internalized in all the members of the organization.Thus, although strategic formulation is still faculty of top management, in some way it is influenced byother members of the organization.
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