Información tecnológica

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List of Papers (Total 133)

Efecto de un Pretratamiento Químico en el Deshidratado del Arándano por Métodos Combinados

The objective of this paper was to study the chemical removal of blueberry skin at different soda concentrations and immersion times. In methodology, a surface response factorial design of type 22 was considered. As a response, blueberry skin removal was considered, either total or partial. The variables analyzed were soda concentration and immersion time. Results indicated that...

Análisis Energético y Económico de Sistemas Simples de Cogeneración

This paper investigates energy savings and economic aspects related to the use of internal combustion engines in cogeneration plants for buildings. Technical criteria that characterize the operation of simple cogeneration systems with variable thermal energy demands are defined. Also, the problem of finding the annual operational strategies for the variations of load demands and...

Estudio Cinético y de Superficie de Respuesta para la Rehidratación de Zanahorias (Daucus carota) Liofilizadas

In this work the effect of temperature on  the kinetics, the diffusion coefficient sand the addition of citric acid and sodium chloride on the rehydration of frozen-dried carrots (Daucus carota) have been studied. The model response surface was 4 factors with 3 central points. For 70 and 93 ºC, no significant differences (a=0.05) for the kinetic constant with mean of 0.42min-1...

Propiedades Físicas y Mecánicas de Bloques de Hormigón Compuestos con Áridos Reciclados

The main objective of this paper is to show a technique for the construction of prefabricated concrete bricks utilizing recycled aggregates coming from demolitions of pavements and to check the degree of fulfillment of the current rules that are applied to the manufacture of these building elements. The physical and grain-size characteristics of the aggregates constituent of the...

Evaluación del Contenido de Licopeno en Pastas de Tomate Comerciales

Lycopene content and some physicochemical and microbiological properties of tomato pastes, three made in Venezuela and one imported, were determined. The methodology consisted of the extraction of the carotenoid compounds present in the tomato pastes with acetone. Then, the carotenoid extract was separated and purified by thin layer chromatography using light oil ether as solvent...

Selección de un Modelo Primario para Describir la Curva de Crecimiento de Bacterias Lácticas y Brochothrix thermosphacta sobre Emulsiones Cárnicas Cocidas

Three primary models to describe the growth curve of lactic acid bacteria and Brochothrix thermosphacta on cooked meat emulsions have been compared.  The following kinetic growth parameters were determined: lag time (l), maximum specific growth rate (µmax) and maximum microbial density (ymax). The models Logístico, Gompertz y Baranyi were employed and the goodness-of-fit of the...

Estudio Experimental para la Predicción del Funcionamiento de Evaporadores

In this work, an industrial scale evaporator with one tube, that can be assembled in six different ways, was designed and constructed. A model based on the identification and reduction of variables was developed and an experimental evaluation was made by operating the evaporator in a climbing forced circulation. The data were related applying the global model and a simple...

Aplicación para Formular y Resolver Modelos Matemáticos de Sistemas de Evaporación Multiefecto

An application to formulate and to solve mathematical models of multieffect evaporation systems Is presented. The application allows that any user, without being an expert in optimization, simulation and chemical engineering can simulate, optimize, make re-engineering or synthesize a multieffect evaporation system. The information of the problem is entered by means of tables or...

Análisis de Modelos de Lechos Fuente en Multietapa, utilizando la Distribución del Tiempo de Residencia de los Sólidos

A comparative analysis of flow models developed for the solids in a multistage spouted bed system designed by Arriola (1997), is presented. Models for the residence time distribution, suitable for commercial applications in processing seeds and grains, has been selected in the study. The experimental residence time distribution function was obtained by the stimulus-response...

Evaluación de la Disponibilidad de Minerales en Harinas de Frijol y en Mezclas de Maíz/Frijol Extrudidas

In the present work the effects of extrusion on mineral availability of extruded mixtures based on maize and cowpea (with and without previous inactivation treatment) were analyzed. In the formulation of foods aimed to food programs  the amount and the quality of protein and bioavailability of the nutrients must be considered. One alternative, explored in this work, is to use...

Efecto de Tiempos de Retención Hidráulico de Agua, en un Sistema de Cultivo Experimental de un Paso para Trucha Arcoiris (Oncorhynchus mykiss)

On an experimental fish farming system, two hydraulic retention times, above the normally used values, were tested to evaluate the effect on the growth of rainbow trout (Oncorhynchus mykiss) under normal conditions of production (>700 g), on the quality of water and on the productivity of the system. The results show that there are no differences on the growth between the groups...

Diferentes Técnicas para el Alisado de Tensiones 3D

The combined application of two techniques improved for zone tension smoothing: Superconvergent Patch Recovery (SPR) and Recovery by Equilibrium Patches (REP), are analyzed. The techniques are improved on hexahedrons for three-dimensional domain problems which allow obtaining more exact results when using the finite elements method. To analyze the combination behavior of these...

Cálculo y Predicción de Azeótropos Multicomponentes con Modelos de Coeficientes de Actividad

This paper studies the multicomponent azeotropic capacity prediction of activity coefficient models. Wilson and UNIFAC models are used for homogeneous azeotropes while UNIQUAC and UNIFAC models are used for heterogeneous azeotropes. Calculations were done with the commercial software DISTIL and HYSYS using the DISTIL Data Base for the binary parameters. In the case that binary...

Automatización de un Secador Convectivo de Aire Caliente para fines de Docencia en Ingeniería de Alimentos

This paper describes the design and installation of an automated experimental device applied to a parallel co-current hot air dryer to perform drying studies in the field of food engineering. The development of this work was divided into two main activities: (i) design of the automation system and (ii) validation of automatically collected data. A device capable of collecting and...

Pronóstico de la Concentración de Ozono en Guadalajara-México usando Redes Neuronales Artificiales

A forecasting model to predict the maximum ozone concentration in a specific day in the Metropolitan Area of Guadalajara-Mexico was developed. An Artificial Neuronal Network fed with six meteorological variables and three chemicals was used. Nodes in the hidden layer were varying in a number among 12 and 15. The transfer functions were log-sigmoid for the hidden layer and linear...

Implementación de un Laboratorio Virtual para la enseñanza de Controladores PID

The objective of this work is to develop a teaching tool, which allows variations in the parameters of the controller to see the influence they have on the stability of this process, with the aim of teaching process control using the computer. In the cases studied the values of the parameters were first fixed and then the students are allowed to change them both in the controller...

Un Modelo de Programación No-lineal para la Planeación de la Producción de Gas y Petróleo

In this work, a model to optimize the planning of gas and oil production in several wells is proposed. The planning horizon is divided in several periods for which the demand is known, and a cost coefficient is associated to each well in the objective function. The formulation includes the pressure decrease effect at the wellbore when the well is producing and the pressure...

Comparación del Método del Principio de la Máxima Entropía en la Estimación de Parámetros de la Distribución de Valores Extremos Tipo I

The method of the Principle of Maximum Entropy (POME) applied to the estimation of parameters of the extreme value type I distribution, (EVI) is analyzed. The POME method has been compared with others of widespread use, like the methods of moments (MOM), maximum likelihood (ML) and probability weighted moments (PWM), with both real flood data and through distributional sampling...

Estudio Experimental de la Tensión Interfacial Transitoria para Sistemas Alcanos-Agua-Triton X-100 empleando la Técnica de la Gota Emergente

The objective of this work was to study the effect of the concentration of a non-ionic surfactant in water on the interfacial tension of an alkane series. For this purpose Triton X-100 and the alkanes: hexane, heptane, octane, decane, undecane and dodecane were selected for analysis. The tests were done at concentrations of 10-3, 10-4 and 10-5 mol/L and the emergent drop model...

Comportamiento de Catalizadores PtMo/g-Al2O3-B2O3 en Reacciones de Hidrodesaromatización de Naftaleno e Hidrodesulfuración de Dibenzotiofeno

With the aim of studying the functionalities of hydrodesulfurization (HDS) catalysts, a series of PtMo/g-Al2O3-B2O3 catalysts wit different concentrations of Mo and B were prepared and tested in naphthalene hidrodesaromatization HDA, under H2S atmosphere, and dibenzothiophene (DBT) hydrodesulfurization reactions. It was observed that under the typical conditions of hydrotreatment...

Estudio del Fenómeno Explosión de Superficie en la Reacción NO+CO en Pt(100) por Simulación de Monte Carlo Dinámico

In this work the catalytic reduction of NO by CO on a Pt(100) surface by dynamic Monte Carlo simulation is presented. The objective is to analyze the temporal and spatial-temporal behavior. A Langmuir-Hinshelwood mechanism and a model where all the reaction steps are taken into account are considered and the so-called surface explosion is simulated. The analysis also includes...

Discrepancias en los Cálculos Termodinámicos Relacionados con la Deshidrogenación de Parafinas

In this paper, the differences between the equilibrium constants and conversions, for the dehydrogenation of paraffins, calculated by three methods and the values traditionally accepted in the literature are presented. Usually, it is accepted that the equilibrium conversions, for the dehydrogenation of paraffins, increase with the number of carbons in a monotonous way. However...