oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Search Results: 1 - 10 of 6005 matches for " Elkin Alonso; "
All listed articles are free for downloading (OA Articles)
Page 1 /6005
Display every page Item
DETERMINATION OF THE ISOSTERIC HEAT TO PLANTAIN PULP (musa paradisiaca) BY SORPTION ISOTHERMS
CIRO,HéCTOR; OSORIO,JAIRO ALEXANDER; CORTéS,ELKIN ALONSO;
DYNA , 2008,
Abstract: for sorptional data to be useful in simulation and design of storage and drying systems, they must be represented by equations valid in the conditions usually found in industrial practice. using the modified chung-pfost model and fitted by desorption the net and total isosteric heat of plantain pulp was evaluated. the net isosteric heat decreased with increasing moisture content ranging from 1670 kj/kg (5%.d.b) to 215 kj/kg (26%.d.b) where the better goodness of fit was presented by polynomial and power-law models.
DETERMINATION OF THE ISOSTERIC HEAT TO PLANTAIN PULP (musa paradisiaca) BY SORPTION ISOTHERMS
HéCTOR CIRO,JAIRO ALEXANDER OSORIO,ELKIN ALONSO CORTéS
DYNA , 2008,
Abstract: Las isotermas de sorción para ser usadas en la simulación y dise o de procesos de secado y almacenamiento de alimentos deben ser representadas por modelos válidos dentro de las condiciones encontradas en la práctica industrial. Usando el modelo de Chung-Pfost y ajustado por desorción el calor isostérico neto y totalpara pulpa de plátano fueron determinados. El calor neto isotérico neto decreció con el contenido de humedad del producto variando desde 1670 kJ/kg (5%.d.b) a 215 kJ/kg (26%.d.b) donde esta variación fue representada por el modelo potencial y polinomial.
Levels of physical activity, barriers, and stage of change in an urban population from a municipality in Colombia
Arango,Elkin Fernando; Pati?o,Fredy Alonso; Quintero,Mario Andrés; Arenas,Mónica María;
Colombia Médica , 2011,
Abstract: objective: to assess the levels of physical activity, barriers, and stage of change in an urban population 25 to 50 years of age from the municipality of santa rosa de osos, department of antioquia. materials and methods: a prevalence study was conducted, with a two-stage random sampling among 357 individuals not suffering from any known cardiovascular disease. a pre-designed survey was conducted to assess the levels of physical activity, the stage of change, and physical activity barriers. results: the total low physical activity was 9%, and by domains: work 66.9%, transport 60.8%, household and garden (yard work) 44.8%, and leisure-time 76.2%. the most important physical activity barriers were ?lack of willpower? (70%) and ?lack of time? (46.2%). the most prevalent stages of change were ?contemplation? (40.3%) and ?preparation? (17.1%). conclusion: low physical activity levels were found in different domains of daily life, together with a high prevalence of barriers and stages prior to physical activity practice, mainly among women and obese subjects.
ESTUDIO PRELIMINAR DEL COMPORTAMIENTO REOLOGICO BAJO COMPRESIóN UNIDIRECCIONAL DE LA PULPA DE PLáTANO (Musa AAB Simmonds)
CIRO VELáSQUEZ,HéCTOR JOSé; MONROY LAITON,FABIAN ARMANDO; CORTéS MARíN,ELKIN ALONSO;
DYNA , 2008,
Abstract: samples of plantain pulp (musa aab simmonds) were subjected to tests of unidirectional compression using an analyzer of texture ta-xt2i. the true flow curves (stress-strain) and rheological properties such as stress, strain and toughness to failure point were evaluated. the material was subjected under two loading direction (longitudinal and transversal) and three positions throughout the longitudinal axis of the product: initial, middle and final. the statistical analyses showed that the product is highly anisotropic, where the direction of load and the position within the material are significant effects in the rheological response of the material.
ESTUDIO PRELIMINAR DEL COMPORTAMIENTO REOLOGICO BAJO COMPRESIóN UNIDIRECCIONAL DE LA PULPA DE PLáTANO (Musa AAB Simmonds)
HéCTOR JOSé CIRO VELáSQUEZ,FABIAN ARMANDO MONROY LAITON,ELKIN ALONSO CORTéS MARíN
DYNA , 2008,
Abstract: Pulpa de plátano Dominico-Hartón fue sometida a ensayos de compresión unidireccional usando un analizador de textura TA-XT2i. Las curvas de flujo y las propiedades reológicas del producto a condición de falla como esfuerzo, deformación y tenacidad fueron determinadas. La pulpa fue sometida a dos direcciones de carga (longitudinal y transversal) en tres posiciones a lo largo del eje longitudinal del producto: inicial, medio y final. Los análisis estadísticos mostraron que el material es altamente anisotrópico, donde la dirección de carga y la posición dentro de la material son efectos significativos en la respuesta reológica del producto.
Levels of physical activity, barriers, and stage of change in an urban population from a municipality in Colombia
Elkin Fernando Arango,Fredy Alonso Pati?o,Mario Andrés Quintero,Mónica María Arenas
Colombia Médica , 2011,
Abstract: Objective: To assess the levels of physical activity, barriers, and stage of change in an urban population 25 to 50 yearsof age from the Municipality of Santa Rosa de Osos, department of Antioquia.Materials and methods: A prevalence study was conducted, with a two-stage random sampling among 357 individualsnot suffering from any known cardiovascular disease. A pre-designed survey was conducted to assess the levels of physicalactivity, the stage of change, and physical activity barriers.Results: The total low physical activity was 9%, and by domains: work 66.9%, transport 60.8%, household and garden(yard work) 44.8%, and leisure-time 76.2%. The most important physical activity barriers were lack of willpower (70%)and lack of time (46.2%). The most prevalent stages of change were contemplation (40.3%) and preparation (17.1%).Conclusion: low physical activity levels were found in different domains of daily life, together with a high prevalenceof barriers and stages prior to physical activity practice, mainly among women and obese subjects.
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.
CORRELACIóN ENTRE PROPIEDADES ANATóMICAS, RESISTENCIA A FLEXIóN ESTáTICA Y ENERGíA REQUERIDA PARA EL CORTE DE LA CA?A DE AZúCAR (Saccharum officinarum L.)
González Sánchez,Hugo Alberto; Toro Betancur,Alejandro; álvarez Mejía,Fernando; Cortés Marín,Elkin Alonso;
Revista Facultad Nacional de Agronomía, Medellín , 2008,
Abstract: the microstructure, anatomical structure, bending resistance and the energy required to cut stems of three varieties of sugar cane cultivated in the valle del cauca ( colombia ), were studied in order to have useful data for the development of cutting blades. microestructural and anatomical characterization tasks were performed by optical microscopy ( om), and scanning electron microscopy (sem). the physical and mechanical properties were determined after adaptation of astm standards (which were developed for wood), while the consumption of energy during cutting was evaluated by using a modified charpy type impact pendulum. the fibers and silica particles showed different geometry and distribution in the stems of the three studied varieties, and a relation was established between the microstructure of the stems and the energy required to cut them in the modified charpy pendulum. generally speaking, cutting the internodes required higher specific energy than cutting the nodes, and the use of blades with cutting angle of 20° led to lower levels of energy consumption. also, a relation of proportionality between the effective cross-sectional area of fibers (atef) and the specific energy consumed in cutting, as well as between the flexibility coefficient and the modulus of elasticity in bending were found.
Calidad de vida relacionada con la salud en usuarios de un programa de actividad física = Health-related quality of life in users of a physical activity program
Pati?o Villada, Fredy Alonso,Arango Vélez, Elkin Fernando,Lopera Orrego, Nelson Andrés,Ortiz Colorado, Natalia Andrea
Iatreia , 2011,
Abstract: Introducción: la calidad de vida relacionada con la salud (CVRS) permite evaluar el estado de salud de las personas y dise ar, implementar y evaluar programas de salud. Objetivo: determinar la percepción de la CVRS en usuarios de un programa de actividad física (AF). Metodología: estudio transversal en 177 sujetos pertenecientes a un programa de actividad física. Se aplicó el cuestionario SF-36v1.2 para evaluar la CVRS; se evaluó el consumo máximo de oxígeno (VO2máx) por medio la prueba de 2.000 metros y se determinó la prevalencia de algunos factores de riesgo cardiovascular a partir de las historias clínicas. Resultados: el puntaje promedio de CVRS más alto fue en el funcionamiento físico (FF) 90,5 (DE: 10,8) y más bajo en dolor corporal (DC) 78,1 (DE: 22,4) y vitalidad (VT) 78,1 (DE: 15,5). En las personas fumadoras, hipertensas, diabéticas, obesas y con niveles bajos de actividad fisica la mayoría de los puntajes de CVRS fueron más bajos (diferencias clínica y estadísticamente significativas). El VO2máx mostró correlación con los dominios funcionamiento físico (FF) (rho = 0,371; p = 0,0001), desempe o físico (DF) (rho = 0,177; p = 0,018) y dolor corporal (DC) (rho = 0,207; p = 0,006). Conclusión: las personas estudiadas tienen una percepción buena de la CVRS; sin embargo, en quienes reportaron tabaquismo, hipertensión arterial, diabetes mellitus, obesidad, dislipidemias y baja potencia aeróbica se presentó una menor percepción de la CVRS; las personas con obesidad mostraron mejores puntajes en los dominios del componente mental y aquellos con bajo nivel de AF mostraron puntajes bajos en dicho componente.
CORRELACIóN ENTRE PROPIEDADES ANATóMICAS, RESISTENCIA A FLEXIóN ESTáTICA Y ENERGíA REQUERIDA PARA EL CORTE DE LA CA A DE AZúCAR (Saccharum officinarum L.) CORRELATIONS AMONG ANATOMIC PROPERTIES, BENDING RESISTANCE AND ENERGY REQUIRED TO CUT SUGAR CANE (Saccharum officinarum L.)
Hugo Alberto González Sánchez,Alejandro Toro Betancur,Fernando álvarez Mejía,Elkin Alonso Cortés Marín
Revista Facultad Nacional de Agronomía, Medellín , 2008,
Abstract: La microestructura, estructura anatómica, la resistencia a la flexión y la energía requerida durante el corte de los tallos de tres variedades de ca a de azúcar cultivadas en el Valle del Cauca (Colombia), fueron estudiados con el propósito de adquirir información útil para el desarrollo de cuchillas para corte de esta especie. Las labores de caracterización microestructural y anatómica se apoyaron en las técnicas de microscopía óptica y electrónica de barrido. Las propiedades mecánicas se determinaron adaptando algunas normas ASTM para maderas, mientras que la energía al corte se evaluó usando un péndulo de impacto tipo Charpy modificado. En los tallos de las tres variedades estudiadas se observaron diferentes distribuciones y dimensiones geométricas de las fibras y se verificó la presencia de partículas de sílice. Se presentó en general mayor requerimiento de energía específica al corte en los entrenudos que en los nudos y un menor consumo específico de energía al corte con las cuchillas con ángulo de afilado de 20°. Se establecieron relaciones entre la microestructura de los tallos, comportamiento a la flexión y al corte, destacándose la relación proporcional entre el área transversal efectiva de fibra (ATEF) y la energía específica al corte, así como entre el coeficiente de flexibilidad y el módulo de elasticidad en flexión. The microstructure, anatomical structure, bending resistance and the energy required to cut stems of three varieties of sugar cane cultivated in the Valle del Cauca ( Colombia ), were studied in order to have useful data for the development of cutting blades. Microestructural and anatomical characterization tasks were performed by optical microscopy ( OM), and scanning electron microscopy (SEM). The physical and mechanical properties were determined after adaptation of ASTM standards (which were developed for wood), while the consumption of energy during cutting was evaluated by using a modified Charpy type impact pendulum. The fibers and silica particles showed different geometry and distribution in the stems of the three studied varieties, and a relation was established between the microstructure of the stems and the energy required to cut them in the modified Charpy pendulum. Generally speaking, cutting the internodes required higher specific energy than cutting the nodes, and the use of blades with cutting angle of 20° led to lower levels of energy consumption. Also, a relation of proportionality between the effective cross-sectional area of fibers (ATEF) and the specific energy consumed in cutting, as well as between the fl
Page 1 /6005
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.