New tuning rules for PID controllers based on IMC with minimum IAE for inverse response processes

In this paper new tuning rules for Proportional Integral Derivative (PID) are presented, which are based on Internal Model Control (IMC). This set of equations minimizes the performance index, in this case, the Integral Absolute Error (IAE). Furthermore, a correlation is proposed in order to calculate the tuning parameter of the method, where a holding oscillation response is obtained regarding changes in the set point. This value represents a stability limit for the IMC method. The overall development is then applied to an Inverse Response System of second order and with dead time

Estudio de la estructura de recubrimientos de silicio depositados mediante proyección térmica por llama oxiacetilénica

RESUMEN: Se estudió el efecto del tipo de llama, del tipo de sustrato y de la distancia de proyección sobre la porosidad y el espesor de recubrimientos de silicio depositados por medio de proyección térmica por llama oxiacetilénica. Para la elaboración de los recubrimientos se utilizó una llama reductora, una neutra y una oxidante, con el objetivo de calentar y posteriormente proyectar las partículas de silicio sobre sustratos de aluminio y de Ti6Al4V, a una distancia de proyección de 15 cm y 8.5 cm. Los resultados indican que los recubrimientos depositados a 8.5 cm son más compactos y que la utilización de una llama neutra reduce ligeramente la porosidad y permite tener capas más gruesas. Así mismo, los recubrimientos depositados sobre sustratos de Ti6Al4V presentaron menor porosidad y menos fallas estructurales que los depositados sobre aluminio.ABSTRACT: The effect of flame type, material substrate and spray distance on the porosity and thickness of silicon coatings elaborated by oxy-acetylene flame spray were studied. Reductive, neutral and oxidative flames were used in order to manufacture the coatings on aluminum and Ti6Al4V substrates, using spray distances of 15 cm and 8.5 cm. The results indicate that the coatings elaborated using a spray distance of 8.5 cm are more compact than those manufactured using a spray distance of 15 cm and that the use of a neutral flame slightly decreases the porosity increases thickness. Also the porosity and structural defects in coatings elaborated on Ti6Al4V substrates are lower than those manufactured on aluminum

Implementation of Integrative Projects as a Contribution to the Major Design Experience in Chemical Engineering

The training of chemical engineers requires creating dynamics that bring them closer to the reality of professional practice and providing active learning experiences to develop skills that strengthen critical thinking, autonomy, teamwork, and communication, as a contribution to sustainable engineering education. However, these experiences are isolated, and sometimes do not show an integrated vision between different areas of knowledge. This work aims to introduce the lessons learned by creating capstone integrative projects as tools for the design and control of processes in the Faculty of Chemical Engineering of the Universidad Pontificia Bolivariana. The capstone project was developed in randomly selected groups to develop a basic engineering proposal for an industrial process of local or national interest. Validation was carried out, consisting of surveys of 54 students in the last year of the program, an opinion query of 60 recent graduates, and a focus group of five graduates, with a profile of employers, management of innovation, development, and design of chemical processes. Between 2016 and 2020, more than 43 processes were evaluated with students, evidencing a significant improvement in the skills defined by the faculty in the graduation profile. A total of 94% of the graduates in that period recognize the capstone project as an integrator of design and process control, and it is concluded that this contributes positively to the professional development of the chemical engineer

Implementation of Integrative Projects as a Contribution to the Major Design Experience in Chemical Engineering

The training of chemical engineers requires creating dynamics that bring them closer to the reality of professional practice and providing active learning experiences to develop skills that strengthen critical thinking, autonomy, teamwork, and communication, as a contribution to sustainable engineering education. However, these experiences are isolated, and sometimes do not show an integrated vision between different areas of knowledge. This work aims to introduce the lessons learned by creating capstone integrative projects as tools for the design and control of processes in the Faculty of Chemical Engineering of the Universidad Pontificia Bolivariana. The capstone project was developed in randomly selected groups to develop a basic engineering proposal for an industrial process of local or national interest. Validation was carried out, consisting of surveys of 54 students in the last year of the program, an opinion query of 60 recent graduates, and a focus group of five graduates, with a profile of employers, management of innovation, development, and design of chemical processes. Between 2016 and 2020, more than 43 processes were evaluated with students, evidencing a significant improvement in the skills defined by the faculty in the graduation profile. A total of 94% of the graduates in that period recognize the capstone project as an integrator of design and process control, and it is concluded that this contributes positively to the professional development of the chemical engineer

METODOLOGÍA PARA LA MEDICIÓN DE INNOVACIONES TECNOLÓGICAS APLICADAS A EMPRESAS DEL SECTOR AGROINDUSTRIAL METHODOLOGY TO MEASURE TECHNOLOGICAL INNOVATION APPLIED TO COMPANIES FROM AGROINDUSTRIAL SECTOR

El proyecto contempló en una forma preliminar, el análisis de los indicadores de innovación de empresas del sector de elaboración de productos alimenticios*, según la encuesta del DANE [1] en donde se clasifican las empresas por su grado de innovación. Posteriormente se analizaron los fundamentos matemáticos de la difusión de la innovación tecnológica en tres empresas del sector agroindustrial de Colombia, así como las variables involucradas en este fenómeno; para ello se estudiaron los parámetros de desempeño, ventas y producción en el tiempo, los cuales presentan un comportamiento de curvas en "S" o curva logística con el fin de poder analizar los puntos de inflexión y otros parámetros de innovaciones tecnológicas a través de correlaciones matemáticas. Para analizar las curvas en "S" se tomaron varios modelos matemáticos de distribución logística y luego de encontrar el que se ajustó a los datos de las empresas se procedió a realizar la correlación empleando el software Statgraphics; con esta herramienta se encontraron los valores de las constantes que existen en el modelo. Con las curvas generadas por los datos obtenidos en el sector agroindustrial, con series de tiempos entre uno y cinco años y con los valores de las constantes se analizaron los puntos de inflexión, parámetros de crecimiento y las asíntotas de cada una de las curvas en "S" propuestas, y se generaron conclusiones relacionadas con ciclos de innovación, estrategia de mercadeo, tiempos para la protección de innovaciones y otros parámetros de desempeño que son útiles para las empresas del sector.This project looked at, in a preliminary phase, the innovation indicators analysis for companies from food manufacturing sector according to the survey by DANE in this survey the companies are classified according its innovation level. After that, the mathematical foundations of the technological innovation diffusion were analyzed in three companies from agroindustrial sector in Colombia, moreover the variables involved in this phenomenon, in order to this, performance parameters such as sales and production quantity along the time, are studied. These parameters have behaved as "S" curves or logistic curve, this aims to analyze the inflexion points and some other technological innovation parameter through mathematical correlations. In order to build the "S" curves some mathematical models of logistic distribution were taken and after finding the model that fitted according to the data, the correlation was calculated with Statgraphics software, using this tool the constant values in the model were calculated. With the curves generated with the data of agroindustrial sector, using time series between one and five years and with the calculated value of the constants of the equation, the inflection points, the growing rates and the asymptotes were analyzed for each one of the purposed "S" curves to make conclusions about the innovation cycles, marketing strategies, protection time for the innovation and other performance parameters which are useful for the companies and the sector they belong

Uso de la perforación dinámica como un método alternativo para determinar el comportamiento mecánico de materiales refractarios

La dureza de los materiales cerámicos generalmente se determina mediante microindentación Vickers, para lo cual la muestra debe ser rigurosamente pulida y se deben analizar múltiples huellas para que el resultado sea representativo de las propiedades..

Uso de la perforación dinámica como un método alternativo para determinar el comportamiento mecánico de materiales refractarios

Ceramic materials hardness is usually determined by Vickers microindentation, which requires rigorous sample preparation and highly demanding analysis of traces turning this method difficult to use in industrial applications. This research is focused to correlate Vickers Hardness to drilling resistance by a hard-tipped drill-bit on alumina, alumina-zirconia-silica (AZS) and alumina-chromite refractories bricks. Alumina and AZS bricks were manufactured by electromelting process leading to obtain highly densified microstructures, while alumina-chromite bricks were manufactured by pressing and sintering which conducts to lower densification and particles cohesion within the bricks microstructure. Alumina and AZS refractories measured hardness is 1506.00 ± 99.71 HV1,5N (15.10 ± 0.90 GPa) and 1028.00 ± 95.49HV2,7N (10.30 ± 0.90 GPa) respectively, which is in contrast with the low measured hardness on alumina-chromite bricks of 54.00 ± 2.00 HV50N (0.54 ± 0.02 GPa) despite of the high hardness of alumina and chromite used as feedstock maybe due to a low cohesion between the particles. Drilling resistance results showed a well-fitted behavior regarding the measured Vickers hardness then the drilling resistance test is useful to predict the hardness of highly densified as well as of friable ceramic materials.La dureza de los materiales cerámicos generalmente se determina mediante microindentación Vickers, para lo cual la muestra debe ser rigurosamente pulida y se deben analizar múltiples huellas para que el resultado sea representativo de las propiedades mecánicas del material, dificultando su uso en el ámbito industrial. En este trabajo se relacionó la dureza Vickers de ladrillos refractarios de alúmina, alúminacircona-sílice (AZS) y de alúmina-cromita, con la resistencia que tienen los mismos a ser perforados por una broca para concreto con punta de carburo de tungsteno. Los refractarios de alúmina y de AZS estudiados fueron fabricados por electrofusión, lo que les confiere alta densificación, mientras que los de alúmina-cromita fueron manufacturados mediante prensado y sinterizado y, por lo tanto, la cohesión entre las partículas que los constituyen y su densificación es baja. La dureza medida para el ladrillo de alúmina y el de AZS es de 1506,00 ± 99,71 HV1,5N (15,10 ± 0,90 GPa) y 1028,00 ± 95,49 HV2,7N (10,30 ± 0,90 GPa) respectivamente, mientras que para el de alúminacromita la dureza es sorprendentemente baja, tan solo de 54,00 ± 2,00 HV50N (0,54±0,02 GPa), a pesar de que este material está constituido por partículas altamente duras, lo cual es producto de la baja cohesión de dichas partículas. Los resultados obtenidos indican que existe buena concordancia entre la resistencia a la perforación y la dureza Vickers de los ladrillos estudiados, por lo que el ensayo de perforación mecánica puede ser utilizado para predecir la dureza tanto en materiales cerámicos bien densificados, como en aquellos poco densificados

El cultivo de plátano : manual técnico

Aspectos socioeconómicos del cultivo de plátano en colombia -- La planta de plátano -- La semilla de plátano -- Establecimieno del cultivo -- Sistemas agroforestales con plátano para el eje cafetero -- Manejo del suelo -- Manejo del cultivo -- Manejo integrado de plagas -- Manejo integrado de enfermedades -- Enfermedades del fruto -- Cosecha, postcosecha y agroindustria -- Costos de producción.124 página