Howard Nuñez Celis, M. Rincón Ortiz, Andrés González Hern´ández
Cr2O3 coatings were deposited on carbon steel through the flame spraying technique using two types of flames (neutral and oxidizing). The protective and morphological characteristics of the coatings were determined. The coatings had layer thickness values of 114 and 214µm for oxidizing and neutral samples, respectively. Porosity percentages of 4.5 % and 2.5 % were determined, where the neutral sample presented the greatest porosity due to the insufficient fusion of the oxide particles during the process, resulting in the formation of a heterogeneous and less compact layer. Microcracks and pores were found on the surface and cross-section of the coatings, due to the thermal expansion generated during the solidification process. The coating protective capacity was evaluated by electrochemical techniques over 672 hours in a 3.5 %wt NaCl saline solution. The results evidenced that the coatings manufactured with the oxidizing flame presented more corrosion resistance compared to those prepared with the neutral flame. The corrosion products were more evident in the neutral flame coatings, because of the diffusion mechanisms from the substrate to the surface coating through the interconnected pores. Finally, the wettability of the sodium chloride solution in the Cr2O3 coatings was measured by the contact angle technique, finding that the oxidizing flame coatings exhibited a higher angle contact value (64.8°) in contrast to the neutral flame coatings (35°).
{"title":"Corrosion Behavior of Flame Sprayed Cr2O3 Coatings on Carbon Steel in Chloride Solutions","authors":"Howard Nuñez Celis, M. Rincón Ortiz, Andrés González Hern´ández","doi":"10.22395/rium.v21n40a9","DOIUrl":"https://doi.org/10.22395/rium.v21n40a9","url":null,"abstract":"Cr2O3 coatings were deposited on carbon steel through the flame spraying technique using two types of flames (neutral and oxidizing). The protective and morphological characteristics of the coatings were determined. The coatings had layer thickness values of 114 and 214µm for oxidizing and neutral samples, respectively. Porosity percentages of 4.5 % and 2.5 % were determined, where the neutral sample presented the greatest porosity due to the insufficient fusion of the oxide particles during the process, resulting in the formation of a heterogeneous and less compact layer. Microcracks and pores were found on the surface and cross-section of the coatings, due to the thermal expansion generated during the solidification process. The coating protective capacity was evaluated by electrochemical techniques over 672 hours in a 3.5 %wt NaCl saline solution. The results evidenced that the coatings manufactured with the oxidizing flame presented more corrosion resistance compared to those prepared with the neutral flame. The corrosion products were more evident in the neutral flame coatings, because of the diffusion mechanisms from the substrate to the surface coating through the interconnected pores. Finally, the wettability of the sodium chloride solution in the Cr2O3 coatings was measured by the contact angle technique, finding that the oxidizing flame coatings exhibited a higher angle contact value (64.8°) in contrast to the neutral flame coatings (35°).","PeriodicalId":31131,"journal":{"name":"Revista Ingenierias Universidad de Medellin","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43153276","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Soil salinization is one of the main constraints for food production. These processes occur mainly in irrigated areas, due to natural conditions and inadequate fertilization and irrigation practices. The objective of this article was to generate a model to identify and spatialize the levels of vulnerability to soluble phase salinization in the irrigation districts of Colombia as a complementary tool for the management of soil salinization risk. Two tools were integrated to achieve the objective. On the one hand, the multi-criteriaanalysis method called Analytic Hierarchy Process (AHP) was applied to assign weights to the analysis parameters and build the Soil Vulnerability to Salinization Index (SVSS), and on the other hand, geographic information systems (GIS) were applied to spatialize the analysis parameters and the SVSS, as well as to define the homogeneous vulnerability zones. Finally, the model was applied to a case study. The resulting model considered vulnerability parameters. The most important are Aridity Index, Soil Texture and Fertilization Practices. On a second level are Drainage Infrastructure and Depth of the Water Level. Other factors considered were Slope of the land, Irrigation Water Application Efficiency and Irrigation Water Distribution Pattern. In the case study it was found that 71.8 % of the territory presents Medium Vulnerability and 27.9 % High Vulnerability. The determining parameters of these results were the low efficiencies of irrigation water application, inadequate fertilization practices, clayey textures and lack of subsurface drainage systems.
{"title":"METHODOLOGICAL PROPOSAL TO ASSESS THE VULNERABILITY OF SOILS TO SALINIZATION IN FLAT AREA IRRIGATION DISTRICTS","authors":"Andrés Echeverri Sánchez","doi":"10.22395/rium.v21n40a3","DOIUrl":"https://doi.org/10.22395/rium.v21n40a3","url":null,"abstract":"Soil salinization is one of the main constraints for food production. These processes occur mainly in irrigated areas, due to natural conditions and inadequate fertilization and irrigation practices. The objective of this article was to generate a model to identify and spatialize the levels of vulnerability to soluble phase salinization in the irrigation districts of Colombia as a complementary tool for the management of soil salinization risk. Two tools were integrated to achieve the objective. On the one hand, the multi-criteriaanalysis method called Analytic Hierarchy Process (AHP) was applied to assign weights to the analysis parameters and build the Soil Vulnerability to Salinization Index (SVSS), and on the other hand, geographic information systems (GIS) were applied to spatialize the analysis parameters and the SVSS, as well as to define the homogeneous vulnerability zones. Finally, the model was applied to a case study. The resulting model considered vulnerability parameters. The most important are Aridity Index, Soil Texture and Fertilization Practices. On a second level are Drainage Infrastructure and Depth of the Water Level. Other factors considered were Slope of the land, Irrigation Water Application Efficiency and Irrigation Water Distribution Pattern. In the case study it was found that 71.8 % of the territory presents Medium Vulnerability and 27.9 % High Vulnerability. The determining parameters of these results were the low efficiencies of irrigation water application, inadequate fertilization practices, clayey textures and lack of subsurface drainage systems.","PeriodicalId":31131,"journal":{"name":"Revista Ingenierias Universidad de Medellin","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47337736","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Lina Patricia Vega-Garzon, Jeimy Alejandra Parra Ramos, Maria Paz García Sarmiento, Maria Alejandra Ruiz Gaitán, Liz Anyury Pedraos Juya
This paper aims to make a bibliographic literature review about the current and potential uses of geothermal energy within the food industry, which uses a third of the world’s energy during production in all the processes involved. Fossil fuels are the most common sources for generating electrical energy for the food industry. However, it is known that they cause adverse environmental effects such as atmospheric pollution, ecosystem disturbances and natural resource depletion. Due to the lack of published studies about this subject, this review was carried out using different databases. Of the 77 documents published between 2010 and 2020, more than 70 % of them were written in English by researchers from 67 institutions from around the world. These documents allow us to analyze a sample of countries where the implementation of geotermal energy has a greater advance in processes implementing geothermal energy in the food industry; such as heating and cooling systems for the drying of fruits and vegetables, and producing various foods, achieving energy coverage close to 10 % in this industry.
{"title":"USE OF GEOTHERMAL ENERGY IN THE FOOD INDUSTRY: A REVIEW","authors":"Lina Patricia Vega-Garzon, Jeimy Alejandra Parra Ramos, Maria Paz García Sarmiento, Maria Alejandra Ruiz Gaitán, Liz Anyury Pedraos Juya","doi":"10.22395/rium.v21n40a5","DOIUrl":"https://doi.org/10.22395/rium.v21n40a5","url":null,"abstract":"This paper aims to make a bibliographic literature review about the current and potential uses of geothermal energy within the food industry, which uses a third of the world’s energy during production in all the processes involved. Fossil fuels are the most common sources for generating electrical energy for the food industry. However, it is known that they cause adverse environmental effects such as atmospheric pollution, ecosystem disturbances and natural resource depletion. Due to the lack of published studies about this subject, this review was carried out using different databases. Of the 77 documents published between 2010 and 2020, more than 70 % of them were written in English by researchers from 67 institutions from around the world. These documents allow us to analyze a sample of countries where the implementation of geotermal energy has a greater advance in processes implementing geothermal energy in the food industry; such as heating and cooling systems for the drying of fruits and vegetables, and producing various foods, achieving energy coverage close to 10 % in this industry.","PeriodicalId":31131,"journal":{"name":"Revista Ingenierias Universidad de Medellin","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44705598","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
La escasez hídrica en zonas con precipitaciones abundantes a causa de sequías resulta ser, en cierto sentido, contradictorio; sin embargo, los efectos de dicha situación pueden llegar a tener consecuencias dramáticas en la productividad y desarrollo de las comunidades. Este trabajo evaluó la amenaza por sequía en el departamento de Córdoba, Colombia, mediante el Índice Estandarizado de Precipitación (SPI), para un escenario crítico definido por las intensidades máximas de eventos con ocurrencia de dos años de retorno, utilizando la información de 40 estaciones meteorológicas; evaluando el SPI a escalas de 3 y 6 meses y caracterizando dicho índice en términos de intensidad, duración, frecuencia y magnitud. Los resultadosmuestran la ocurrencia de sequías de intensidad moderada, con frecuencia de 58 % y 56 % a escala trimestral y semestral respectivamente, resultando en amenaza por sequía en categorías media y alta para algunas zonas del departamento; lo cual indica que, si bien sobre la zona de estudio se registran abundantes precipitaciones, se puede presentar escasez del recurso en el largo plazo provocado por sequías.
{"title":"EVALUACIÓN DE AMENAZA POR SEQUÍA EN EL DEPARTAMENTO DE CÓRDOBA, COLOMBIA","authors":"Álvaro José Zabaleta Ortega, Eglendis Nobles Orozco, Teobaldis Mercado Fernández, Ángel Díaz Carvajal","doi":"10.22395/rium.v21n40a6","DOIUrl":"https://doi.org/10.22395/rium.v21n40a6","url":null,"abstract":"La escasez hídrica en zonas con precipitaciones abundantes a causa de sequías resulta ser, en cierto sentido, contradictorio; sin embargo, los efectos de dicha situación pueden llegar a tener consecuencias dramáticas en la productividad y desarrollo de las comunidades. Este trabajo evaluó la amenaza por sequía en el departamento de Córdoba, Colombia, mediante el Índice Estandarizado de Precipitación (SPI), para un escenario crítico definido por las intensidades máximas de eventos con ocurrencia de dos años de retorno, utilizando la información de 40 estaciones meteorológicas; evaluando el SPI a escalas de 3 y 6 meses y caracterizando dicho índice en términos de intensidad, duración, frecuencia y magnitud. Los resultadosmuestran la ocurrencia de sequías de intensidad moderada, con frecuencia de 58 % y 56 % a escala trimestral y semestral respectivamente, resultando en amenaza por sequía en categorías media y alta para algunas zonas del departamento; lo cual indica que, si bien sobre la zona de estudio se registran abundantes precipitaciones, se puede presentar escasez del recurso en el largo plazo provocado por sequías.","PeriodicalId":31131,"journal":{"name":"Revista Ingenierias Universidad de Medellin","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49546913","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Juan Carlos Vesga Ferreira, Martha Fabiola Contreras Higuera, José Antonio Vesga Barrera
Una red LAN es considerada como un escenario en el cual los nodos tienen la necesidad recurrente de transmitir, lo cual genera una disputa constante ara acceder al medio, y las redes BPL (Broadband Power Line) no son una excepción. La tecnología BPL se caracteriza usar las redes energéticas como medios de transmisión y para esto usa varios estándares, estando el IEEE 1901 entre ellos, debido a su amplia aceptación, Basados en el crecimiento de la demanda de estos nuevos servicios y para ofrecer niveles aceptables de QoS (Calidad del Servicio en sus siglas en inglés), el IEEE 1901 opera un mecanismo híbrido de acceso al medio soportado por CSMA/CA y TDMA. Sin embargo, esta estrategia ha mostrado muy poca eficiencia al incrementarse el número de nodos en la red, ya que solo puede haber un nodo transmitiendo al mismo tiempo. Este artículo propone un mecanismo de acceso al medio en OFDMA (Orthogonal Frequency-Division Multiple Access), basado en juegos de votación ponderada y soportado por el índice de poder Deegan-Packel con el fin de optimizar el acceso en el tiempo y frecuencia del dominio, mejorando así el desempeño de la red y permitiendo que múltiples nodos transmitan simultáneamente.
{"title":"Uso del índice de poder Deegan-Packel para la optimización de acceso al medio en redes LAN con tecnologías BPL","authors":"Juan Carlos Vesga Ferreira, Martha Fabiola Contreras Higuera, José Antonio Vesga Barrera","doi":"10.22395/rium.v21n40a7","DOIUrl":"https://doi.org/10.22395/rium.v21n40a7","url":null,"abstract":"Una red LAN es considerada como un escenario en el cual los nodos tienen la necesidad recurrente de transmitir, lo cual genera una disputa constante ara acceder al medio, y las redes BPL (Broadband Power Line) no son una excepción. La tecnología BPL se caracteriza usar las redes energéticas como medios de transmisión y para esto usa varios estándares, estando el IEEE 1901 entre ellos, debido a su amplia aceptación, Basados en el crecimiento de la demanda de estos nuevos servicios y para ofrecer niveles aceptables de QoS (Calidad del Servicio en sus siglas en inglés), el IEEE 1901 opera un mecanismo híbrido de acceso al medio soportado por CSMA/CA y TDMA. Sin embargo, esta estrategia ha mostrado muy poca eficiencia al incrementarse el número de nodos en la red, ya que solo puede haber un nodo transmitiendo al mismo tiempo. Este artículo propone un mecanismo de acceso al medio en OFDMA (Orthogonal Frequency-Division Multiple Access), basado en juegos de votación ponderada y soportado por el índice de poder Deegan-Packel con el fin de optimizar el acceso en el tiempo y frecuencia del dominio, mejorando así el desempeño de la red y permitiendo que múltiples nodos transmitan simultáneamente.","PeriodicalId":31131,"journal":{"name":"Revista Ingenierias Universidad de Medellin","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43321642","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Edward Andrés García-Saavedra, Alejandra Torres-Velasco, C. Medina-Ramírez, Juan Manuel Barraza-Burgos, J. Guerrero-Pérez
En este trabajo se evaluó la morfología de carbonizados provenientes de mezclas de bagazo de caña de azúcar y carbón con concentraciones de bagazo de 0, 25, 50, 75 y 100 % p/p y tamaños de partícula -0.25 mm y -20 mm. Las muestras se alimentaron a un proceso de desvolatilización a 900 °C en un reactor tubular de arrastre (-0.25 mm) y un reactor de lecho fijo tipo batch (-20 mm). La morfología de los carbonizados se determinó a través de análisis de imagen. El área superficial se evaluó por medio de análisis BET para tamaño de partícula -0.25 mm. Los resultados mostraron que para tamaños de partícula -20 mm se obtuvieron efectos sinergísticos hacia la generación de morfologías reactivas (paredes delgadas + paredes gruesas) con el aumento de la concentración de bagazo. Se encontró que el carbón generó mayor concentración de morfologías tipo pared gruesa y sólido.
{"title":"MORFOLOGÍA DE CARBONIZADOS DE MEZCLAS BAGAZO-CARBÓN: EFECTO DEL TAMAÑO DE PARTÍCULA Y CONCENTRACIÓN DE BAGAZO","authors":"Edward Andrés García-Saavedra, Alejandra Torres-Velasco, C. Medina-Ramírez, Juan Manuel Barraza-Burgos, J. Guerrero-Pérez","doi":"10.22395/rium.v21n40a4","DOIUrl":"https://doi.org/10.22395/rium.v21n40a4","url":null,"abstract":"En este trabajo se evaluó la morfología de carbonizados provenientes de mezclas de bagazo de caña de azúcar y carbón con concentraciones de bagazo de 0, 25, 50, 75 y 100 % p/p y tamaños de partícula -0.25 mm y -20 mm. Las muestras se alimentaron a un proceso de desvolatilización a 900 °C en un reactor tubular de arrastre (-0.25 mm) y un reactor de lecho fijo tipo batch (-20 mm). La morfología de los carbonizados se determinó a través de análisis de imagen. El área superficial se evaluó por medio de análisis BET para tamaño de partícula -0.25 mm. Los resultados mostraron que para tamaños de partícula -20 mm se obtuvieron efectos sinergísticos hacia la generación de morfologías reactivas (paredes delgadas + paredes gruesas) con el aumento de la concentración de bagazo. Se encontró que el carbón generó mayor concentración de morfologías tipo pared gruesa y sólido.","PeriodicalId":31131,"journal":{"name":"Revista Ingenierias Universidad de Medellin","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43119431","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Daniel Maestre-Cambronel, J. P. Rojas, J. Duarte-Forero
Induction motors have played a central role in the techno-economic development of modern industries and electric power generation. However, the presence of recurring failures hinders a cost-effective performance and leads to catastrophic damage. Therefore, the present study proposed an assessment to investigate the influence of two types of failures in induction motors, namely failure due to broken bars in the rotor and defects in the connection between the rotor bars and the end ring. Accordingly, a three-phase induction motor was evaluated under different failure conditions that modified the operational torque and rotational speed. The results indicated that both types of failures magnify both the core and copper power losses by up to 13.3 % and 8 %, respectively, compared to the healthy condition. On the other hand, an efficiency reductionbetween 1.94 % to 3.41 % is an indication of failure progression. Finally, the appearance of harmonics 3 and 7, and the intensified magnitude of harmonic 5, represent a clear sign of failure occurrence related to rotor barsand defects in the connection to the end ring. In conclusion, the proposed methodology proved to be an adequate tool to predict failure appearance, which has a direct impact on extending the lifetime of induction motors.
{"title":"EVALUATION OF FAULTS IN THE SQUIRREL CAGE THREE-PHASE INDUCTION MOTORS","authors":"Daniel Maestre-Cambronel, J. P. Rojas, J. Duarte-Forero","doi":"10.22395/rium.v21n40a8","DOIUrl":"https://doi.org/10.22395/rium.v21n40a8","url":null,"abstract":"Induction motors have played a central role in the techno-economic development of modern industries and electric power generation. However, the presence of recurring failures hinders a cost-effective performance and leads to catastrophic damage. Therefore, the present study proposed an assessment to investigate the influence of two types of failures in induction motors, namely failure due to broken bars in the rotor and defects in the connection between the rotor bars and the end ring. Accordingly, a three-phase induction motor was evaluated under different failure conditions that modified the operational torque and rotational speed. The results indicated that both types of failures magnify both the core and copper power losses by up to 13.3 % and 8 %, respectively, compared to the healthy condition. On the other hand, an efficiency reductionbetween 1.94 % to 3.41 % is an indication of failure progression. Finally, the appearance of harmonics 3 and 7, and the intensified magnitude of harmonic 5, represent a clear sign of failure occurrence related to rotor barsand defects in the connection to the end ring. In conclusion, the proposed methodology proved to be an adequate tool to predict failure appearance, which has a direct impact on extending the lifetime of induction motors.","PeriodicalId":31131,"journal":{"name":"Revista Ingenierias Universidad de Medellin","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46337446","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mónica Andrea Botero Londoño, Hermann Raul Vargas Torres, Clara Lilia Calderón Triana
In this work, solar cells with Mo/CuInSe2/CdS/n+–ZnO structure were deposited and experimentally characterized by the I-V curve. From these results, the electrical parameters were estimated fitting, theoretically, the curve to determine the most important variables. The estimation was carriedout using the single and double diode models and comparing the curve that best fits. The estimated variables were photogenerated current (Iph), dark current of the diode (Is), series resistance (Rs), shunt resistance (Rp) and diode ideality factors (a1 and a2) according to each model of circuit taken for optimization. The adjustment of the current-voltage (I-V) and power-voltage (P-V) curves achieved with the double diodemodel indicates that in the manufactured solar cells, interfacial states are present in the p-n junction, which decreases the efficiency of the device.
{"title":"PRODUCTION OF SOLAR CELLS AND ESTIMATION OF ITS ELECTRICAL PARAMETERS FROM ITS EXPERIMENTAL CHARACTERIZATION","authors":"Mónica Andrea Botero Londoño, Hermann Raul Vargas Torres, Clara Lilia Calderón Triana","doi":"10.22395/rium.v21n40a2","DOIUrl":"https://doi.org/10.22395/rium.v21n40a2","url":null,"abstract":"In this work, solar cells with Mo/CuInSe2/CdS/n+–ZnO structure were deposited and experimentally characterized by the I-V curve. From these results, the electrical parameters were estimated fitting, theoretically, the curve to determine the most important variables. The estimation was carriedout using the single and double diode models and comparing the curve that best fits. The estimated variables were photogenerated current (Iph), dark current of the diode (Is), series resistance (Rs), shunt resistance (Rp) and diode ideality factors (a1 and a2) according to each model of circuit taken for optimization. The adjustment of the current-voltage (I-V) and power-voltage (P-V) curves achieved with the double diodemodel indicates that in the manufactured solar cells, interfacial states are present in the p-n junction, which decreases the efficiency of the device.","PeriodicalId":31131,"journal":{"name":"Revista Ingenierias Universidad de Medellin","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42598537","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Johan Sebastian Ibañez Ramírez, Tatiana Echeverri Salazar, Omar Danilo Castrillón Gómez
El objetivo de este artículo es medir a través de técnicas inteligentes el nivel de vida universitaria de una población universitaria. En esta investigación, una variable dependiente llamada calidad de vida universitaria se toma en cuenta junto con 10 variables independientes: carga académica, recursos económicos, relación con compañeros de clase, relación con docentes, currículum, actividades extracurriculares, vivienda actual,relaciones familiares, estado emocional y entorno universitario. Para el muestreo de estas variables se llevaron a cabo 127 encuestas a estudiantes de una universidad pública ubicada en la región central del país.Subsecuentemente, las variables más relevantes fueron seleccionadas a través de técnicas estadísticas con el fin de establecer un archivo de análisis desde el algoritmo de clasificación de árbol de decisiones J48 de la plataforma Weka. EL resultado demuestra, con una efectividad de más del 80 % que las variables más influyentes en la calidad de vida universitaria son: entorno universitario, vivienda actual, estado emocional y relación con los docentes, encontrando, varias veces, que la calidad de vida también puede depender de variables externas a la universidad, tales como: vivienda actual y estado emocional. Estos resultados son de gran importancia en el diseño de las políticas universitarias por venir.
{"title":"Predicción de la calidad de vida universitaria a través de minería de datos","authors":"Johan Sebastian Ibañez Ramírez, Tatiana Echeverri Salazar, Omar Danilo Castrillón Gómez","doi":"10.22395/rium.v21n40a1","DOIUrl":"https://doi.org/10.22395/rium.v21n40a1","url":null,"abstract":"El objetivo de este artículo es medir a través de técnicas inteligentes el nivel de vida universitaria de una población universitaria. En esta investigación, una variable dependiente llamada calidad de vida universitaria se toma en cuenta junto con 10 variables independientes: carga académica, recursos económicos, relación con compañeros de clase, relación con docentes, currículum, actividades extracurriculares, vivienda actual,relaciones familiares, estado emocional y entorno universitario. Para el muestreo de estas variables se llevaron a cabo 127 encuestas a estudiantes de una universidad pública ubicada en la región central del país.Subsecuentemente, las variables más relevantes fueron seleccionadas a través de técnicas estadísticas con el fin de establecer un archivo de análisis desde el algoritmo de clasificación de árbol de decisiones J48 de la plataforma Weka. EL resultado demuestra, con una efectividad de más del 80 % que las variables más influyentes en la calidad de vida universitaria son: entorno universitario, vivienda actual, estado emocional y relación con los docentes, encontrando, varias veces, que la calidad de vida también puede depender de variables externas a la universidad, tales como: vivienda actual y estado emocional. Estos resultados son de gran importancia en el diseño de las políticas universitarias por venir.","PeriodicalId":31131,"journal":{"name":"Revista Ingenierias Universidad de Medellin","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47132939","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Andrés Mauricio Paredes Rodríguez, Juan Carlos Osorio Gómez
En la actualidad, la gestión de inventarios se ha convertido en una decisión estratégica para las organizaciones, debido al alto impacto que tiene sobre el desempeño general de las cadenas de suministro. En el presente estudio se evalúa el impacto que tiene la implementación de una política de inventario R, S en el flujo de caja de una red de distribución. La investigación involucra el funcionamiento de una cadena de suministro de artículos ferreteros conformada por un detallista y un fabricante, la cual es simulada a través de la herramienta dinámica de sistemas. Los principales resultados del estudio validan el impacto positivo que tiene la ejecución de la política sobre la liquidez de la red. Asimismo, se logra determinar la dominancia que tienen sobre el desempeño general del sistema parámetros como la demanda, el periodo de revisión y la capacidad máxima de producción.
{"title":"Simulación dinámica de una política de inventario R, S en una cadena de suministro de artículos ferreteros","authors":"Andrés Mauricio Paredes Rodríguez, Juan Carlos Osorio Gómez","doi":"10.22395/rium.v20n39a11","DOIUrl":"https://doi.org/10.22395/rium.v20n39a11","url":null,"abstract":"En la actualidad, la gestión de inventarios se ha convertido en una decisión estratégica para las organizaciones, debido al alto impacto que tiene sobre el desempeño general de las cadenas de suministro. En el presente estudio se evalúa el impacto que tiene la implementación de una política de inventario R, S en el flujo de caja de una red de distribución. La investigación involucra el funcionamiento de una cadena de suministro de artículos ferreteros conformada por un detallista y un fabricante, la cual es simulada a través de la herramienta dinámica de sistemas. Los principales resultados del estudio validan el impacto positivo que tiene la ejecución de la política sobre la liquidez de la red. Asimismo, se logra determinar la dominancia que tienen sobre el desempeño general del sistema parámetros como la demanda, el periodo de revisión y la capacidad máxima de producción.","PeriodicalId":31131,"journal":{"name":"Revista Ingenierias Universidad de Medellin","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49122048","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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