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Search Results: 1 - 10 of 404376 matches for " Héctor José; Moreno Cárdenas "
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Biocombustibles: búsqueda de alternativas
Cortés Marírr,Elkin Alonso; Ciro Velásquez,Héctor José; Moreno Cárdenas,Edilson León;
CES Medicina Veterinaria y Zootecnia , 2011,
Abstract: today, the world is looking for different alternatives in order to solve the increasing difficulties that face its development, the feeding of its population and, in particular the feeding of developing nations. at the same time, the growing energy demand foreshadows the exhaustion of hydrocarbon reserves in the short and medium term and likewise a significant deterioration of natural resources, especially the contamination of water and the erosion of soil. in order to prevent irreversible changes and reduce the impact of greenhouse gases on the planet's climate, many countries have chosen to gamble on different strategies for the diversification of energy production utilizing renewable energy sources. the replacement of petroleum derived fuel with biofuels provides a reduction in co2 emissions generated by vehicles. this appears to indicate that the biofuels could potentially be an option, but one not without questions. the new agro-energy industry, unlike that of the oil industry, involves a production chain that impacts more directly the different sectors of the economy, especially the generation of employment, agricultural development and the agro-industry. the addition of biofuels to fuel mixtures can partially mitigate the need for the importation of hydrocarbons, which furthers the national biofuel policy versus energy trade balance, and to a certain extent defines the parameters for security at the supply level. the goal of this paper is to assess the possible scenario of replacement of the current energy matrix with vegetable derived alternative products.
Coronaria izquierda que emerge del seno coronario derecho en una paciente de 64 a os con angina
Francisco L. Moreno-Martínez,Luis F. Vega Fleites,Héctor A. Fleites Cárdenas
Revista Argentina de Cardiología , 2005,
Abstract:
Frecuencia de pseudoprognatismo y actividad del músculo masetero en pacientes fisurados
Ogalde L,Armando; Cárdenas A,Hernán; González N,José; Montoya S,Héctor;
Revista médica de Chile , 2000, DOI: 10.4067/S0034-98872000000900007
Abstract: background: as a consequence of a growth inhibition of middle third of the face, cleft lip surgery could lead to a pseudoprognathism. however, this is not always the case. also, when facial architecture is changed, the activity of muscles such as the masseter could be disturbed. aim: to study masseter electromyographic activity in operated cleft lip patients. material and methods: forty two patients with cleft lip (25 male, aged 13 to 35 years old) were studied. all were operated during their first year of life. an electromyography of masseter muscle was performed and from a teleradiography, anb and gonion angles were obtained. forty healthy subjects conformed the control group results: the sample was divided in two groups. a group of 20 patients had a significantly lower emg voltaje than control subjects (662 ± 228 and 1511 ± 340 μv respectively, p < 0.001). only seven patients had an anteriorly inverted bite with a mean anb of + 1.7 and a mean molar relation of -4.8, figures that confirm the presence of pseudoprognathism. conclusions: eighty three percent of cleft lip patients do not have cephalometric parameters of pseudoprognathism and half of the patients have a lower masseter activity (rev méd chile 2000; 128: 1005-1010)
Frecuencia de pseudoprognatismo y actividad del músculo masetero en pacientes fisurados Pseudoprognathism frequency and masseter muscle activity in operated cleft lip patients
Armando Ogalde L,Hernán Cárdenas A,José González N,Héctor Montoya S
Revista médica de Chile , 2000,
Abstract: Background: As a consequence of a growth inhibition of middle third of the face, cleft lip surgery could lead to a pseudoprognathism. However, this is not always the case. Also, when facial architecture is changed, the activity of muscles such as the masseter could be disturbed. Aim: To study masseter electromyographic activity in operated cleft lip patients. Material and methods: Forty two patients with cleft lip (25 male, aged 13 to 35 years old) were studied. All were operated during their first year of life. An electromyography of masseter muscle was performed and from a teleradiography, ANB and Gonion angles were obtained. Forty healthy subjects conformed the control group Results: The sample was divided in two groups. A group of 20 patients had a significantly lower EMG voltaje than control subjects (662 ± 228 and 1511 ± 340 μV respectively, p < 0.001). Only seven patients had an anteriorly inverted bite with a mean ANB of + 1.7 and a mean molar relation of -4.8, figures that confirm the presence of pseudoprognathism. Conclusions: Eighty three percent of cleft lip patients do not have cephalometric parameters of pseudoprognathism and half of the patients have a lower masseter activity (Rev Méd Chile 2000; 128: 1005-1010)
ANGIOPLASTIA DE RESCATE EN MUJER DE 33 A OS CON ANTICONCEPCIóN ORAL Y CORONARIOPATíA DILATADA / Rescue angioplasty in a 33-year old woman with oral contraception and dilated coronariopathy
Francisco L Moreno-Martínez,Luis F. Vega Fleites,Héctor A. Fleites Cárdenas,Rosendo S. Ibargollín Hernández
CorSalud , 2009,
Abstract: Coronary angioplasty is recognized nowadays as the first-choice therapeutic strategy for acute coronary syndrome with ST-segment elevation. Atherosclerotic disease is still the main cause ofthis sickness; however, other disturbances, such is dilated coronariopathy, may favor this coronary event. Although some authors raise that atherosclerosis is the main cause of coronary dilation, it is uncommon that this lipid disorder promotes consequences early in life. We present the case of a 33-year-old female (oral contraceptive user - etinor) who had not any apparent coronary risk factor but suffered from inferior acute myocardial infarction. The thrombolysis failed, and fortunately we could perform the angioplasty. Intracoronary thrombosis with distal embolism occurred, that waswhy we administered streptokinase. Possible mechanisms that involve oral contraceptives and dilated coronariopathy are discussed, and angiographic images are shown.
Removal of Aqueous Lead and Copper Ions by Using Natural Hydroxyapatite Powder and Sulphide Precipitation in Cyanidation Process  [PDF]
José Refugio Parga, Jesús Leobardo Valenzuela,ctor Vazquez, Mario Rodriguez, Héctor Moreno
Materials Sciences and Applications (MSA) , 2013, DOI: 10.4236/msa.2013.44028
Abstract:

Mining, ore processing, and smelting activities have contaminated soil and water resources with cyanide and heavy metals throughout the world. In-situ chemical immobilization is a remediation technology that decreases the concentrations of dissolved ions of copper cyanide and lead hydroxides by adsorption or precipitation. This study deals, with a process to recover lead hydroxides with natural hydroxyapatite powder and copper cyanide ions with sulphide precipitation from solutions of the cyanidation process. This technology is based on inducing nucleated precipitation of copper and silver in a serpentine reactor, using sodium sulfide as the precipitator, and sulfuric acid for pH control. Results show that pH value has a significant effect on copper cyanide removal efficiency, and it was determined the optimal pH range to be 2.5 - 3. At this pH value, the copper cyanide removal efficiency achieved was up to 99% with 60 percent of copper purity and the cyanide ions associated with this complex the recovery was 90%. For the elimination of lead hydroxides ions from the aqueous cyanidation process with natural hydroxiapatite powder the recovery was 99%. The abundance of cow bones, its low price and non-aggressive nature towards the environment are advantages for its utilization in point of view of wastewater cleanup and Dore with higher quality.

El bicentenario y la reforma del sector público en México. Los afanes de Sísifo
Campero Cárdenas, Gildardo Héctor;
Convergencia , 2009,
Abstract: in mexico since its struggle for his independence there have been promoted administrative reforms and improvements. but neither has it advanced in reversing poverty nor social inequity. with such purpose, as from the 19th century successive programs of administrative reform, structural change, modernization of the state, modernization of the administration, innovation and governmental quality, presidential agenda of good government and improvement of the public management, haven been tried without satisfactory results. there have been no advancement in reversing poverty, inequity and alienation. mexico is a country with two uneven worlds: that of the rich and that of the poor. the governance indicators 2008 show that we are well below nafta, ocde and some latin american countries. in the recent report of the corruption perception index 2008 we have not passed, with a grade of 3.6, in a scale from 0 to 10. as it has been indicated "other nations are doing a better job and they advance faster than mexico", hindered by groups of interest, lack in agreement and other political factors, simulation of change and imitation of neomanagerial models. in countries such as mexico the combat to poverty and the administrative reform are a lot more than a technical reform, they imply transforming the political frameworks of the state, such as control of class, and to pass from imitation to innovation. they demand for political ethics and governance in views of the general collective interest.
El bicentenario y la reforma del sector público en México. Los afanes de Sísifo
Gildardo Héctor Campero Cárdenas
Convergencia , 2009,
Abstract: En México, desde la lucha por su independencia, se han promovido reformas y mejoras administrativas. Tampoco se ha avanzado en revertir la pobreza ni la inequidad so cial. Con tal finalidad, desde el siglo XIX se han intentado sucesivos programas de Reforma Administrativa, Cambio Estructural, Modernización del Estado, Modernización de la Administración, Innovación y Calidad Gubernamental, Agenda Presidencial de Buen Gobierno y Mejora de la Gestión Pública, sin resultados satisfactorios. No se ha avanzado en revertir la pobreza, la inequidad y la marginación so cial. México es un país con dos mundos desiguales: el de los ricos y el de los pobres. Los indicadores de gobernanza para 2008 muestran que estamos muy por debajo de los países del TLC, la OCDE y algunos de América Latina. En el reciente informe del índice de Percepción de Corrupción 2008 salimos reprobados con una calificación de 3.6 en una escala de 0 a 10. Como se ha se alado otras naciones están haciendo un mejor trabajo y avanzan más rápido que México , obstaculizado por grupos de interés, falta de acuerdos y otros factores políticos, la simulación y la necesidad de sustituir la imitación de modelos neogerenciales por la propia innovación. En países como México el combate a la pobreza y la reforma administrativa son mucho más que una reforma técnica o administrativa, implican transformar los marcos políticos del Estado como dominio de clase, y pasar de la imitación a la innovación. Requieren de ética política y de buen gobierno para el interés colectivo gen eral.
Copper and Cyanide Recovery in Cyanidation Effluents  [PDF]
José R. Parga, Jesús L. Valenzuela, Héctor Moreno, Jaime E. Pérez
Advances in Chemical Engineering and Science (ACES) , 2011, DOI: 10.4236/aces.2011.14028
Abstract: Cyanidation is the main process for gold and silver recovery from its ores. In this study, a process is proposed to recover copper and cyanide from barren solutions from the Merrill-Crowe cementation process with zinc dust. This technology is based on inducing nucleated precipitation of copper and silver in a serpentine reactor, using sodium sulfide as the precipitator, and sulfuric acid for pH control. Results show that pH value has a significant effect on copper cyanide removal efficiency, and it was determined the optimal pH range to be 2.5 - 3. At this pH value, the copper cyanide removal efficiency achieved was up to 97 and 99%, when copper concentration in the influent was 636 and 900 ppm. respectively. In this process (sulphidization-acidification-thickening-HCN recycling), the cyanide associated with copper cyanide complexes, is released as HCN gas under weakly acidic conditions, allowing it to be recycled back to the cyanidation process as free cyanide. Cyanide recovery was 90%. Finally, this procedure was successfully run at Minera William in México.
La geología, evolución geomorfológica y geodinámica externa de la ciudad inca de Machupicchu, Cusco-Perú Geology, Morphologic Evolution and Geodynamic Phenomena of Machupicchu Inca City, Cusco-Perú
ctor Carlotto,José Cárdenas,Lionel Fidel
Revista de la Asociación Geológica Argentina , 2009,
Abstract: La ciudad inca de Machupicchu se sitúa dentro del santuario histórico de Machupicchu, en la Cordillera Oriental del sur del Perú; está a 2.450 m s.n.m., 500 m por encima del río Urubamba que corta la cordillera y forma un ca ón, con clima cálido de ceja de selva. La geología, con afloramientos graníticos y bloques de granitos apilados, forma un paisaje de caos granítico, sobre el que fue construida la ciudad inca de Machupicchu. La evolución geológica plio-cuaternaria muestra una exhumación muy rápida de la cordillera, la que condicionó los fenómenos geodinámicos que dieron la geomorfología actual y los fenómenos geodinámicos que afectan a la ciudad inca de Machupicchu. Durante la ocupación inca, los andenes con sistemas de drenajes y las construcciones con techos permitían una evacuación eficaz de las abundantes aguas de lluvias; sin embargo, este no es el caso actualmente, ya que las construcciones no tienen techo y gran parte de los drenajes no funcionan, generando infiltraciones, asentamientos, erosión superficial, sufusión, derrumbes, caída de rocas y deslizamientos superficiales. Los levantamientos geológicos al detalle y los estudios específicos en varias zonas (conjuntos) permiten dar recomendaciones para una adecuada evacuación de las aguas pluviales y evitar las infiltraciones o la erosión superficial, mediante drenajes y pisos impermeables.
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