Kinetics of Drying Medicinal Plants by Hybridization of Solar Technologies

Historically, medicinal plants have always had an important place in medicine. Medicinal plants processing represents a great challenge, due to their compounds sensitive to the environmental conditions that surround and degrade them. Mostly of these plants require to be dry to preserve its safety and medicinal properties; therefore, for proper drying, it is necessary to use sustainable devices that protect the desirable characteristics of plants from direct radiation. In this work, the kinetics of dehydration of three medicinal plants are presented in an indirect solar dryer. In addition, the experimental results were adjusted to nine mostly used models, to estimate the drying conditions required to achieve a desired final moisture content. Modified Page and Page were the models with better fit to experimental results. Furthermore, a computational simulation of temperature evolution and distribution inside the dryer is presented. These results agree with those obtained experimentally

Evaluación Térmica De Un Secador Solar Tipo Túnel Con Hibridación De Tecnologías Solares

Food preservation techniques have allowed seasonal foods to be consumed at any time of the year. Drying has been used for many years as a means of preservation to dry a wide variety of products. A tunnel-type solar dryer with the coupling of solar water and air heating technologies was built in the Faculty of Engineering of the Autonomous University of Campeche, located between the parallels 17°49' and 20°51' north latitude and the meridians 89°06' and 92°27' west longitude. The results of its thermal evaluation considering temperatures within the drying chamber and the climatological parameters are presented in this work. The results indicate that higher temperatures were reached with the air collector, the second-best option turned out to be the use of both technologies at the same time, and the lowest temperatures were obtained with the solar heaters of evacuated tubes, reaching 49°C, 48 °C, and 46 °C, respectively. The highest measured solar irradiation was 936.5 W/m2, the highest ambient temperature was 33.3 °C, and the lowest relative humidity was 63% at 13:00 h.  Las técnicas de conservación de alimentos han permitido que los alimentos estacionales puedan consumirse durante cualquier época del año lo cual es fundamental para garantizar la seguridad alimentaria de todos los habitantes del planeta. El secado se ha utilizado durante muchos años como medio de conservación para secar una gran variedad de productos. Se construyó un secador solar tipo túnel con acoplamiento de tecnologías de calentamiento solar de agua y aire en la Facultad de Ingeniería de la Universidad Autónoma de Campeche, ubicada entre los paralelos 17°49' y 20°51' de latitud norte y los meridianos 89°06' y 92°27' de longitud oeste; se presentan en este trabajo los resultados de su evaluación térmica considerando temperaturas dentro de la cámara de secado y los parámetros climatológicos. Los resultados indican que se alcanzaron mayores temperaturas con el colector de aire, la segunda mejor opción resultó ser la utilización de ambas tecnologías al mismo tiempo y las temperaturas más bajas se obtuvieron con los calentadores solares de tubos evacuados, alcanzando 49 °C, 48 °C y 46 °C, respectivamente. La irradiación solar más alta medida fue de 936.5 W/m2, la temperatura ambiente más elevada, 33.3 °C y la humedad relativa más baja fue de 63 %, a las 13:00 h

MOOC’s para la Educación Continua en Sistemas de Información durante la pandemia

Continuing education of the Universidad Autónoma de Campeche community during the COVID-19 pandemic was carried out through the Coursera for Campus program. This paper presents the methodology and analysis of the results obtained from the university community that participated in the platform program in the area of Information Systems.La educación continua de la comunidad de la Universidad Autónoma de Campeche durante la pandemia por COVID-19 se realizó a través del programa Coursera for Campus. En este trabajo se presenta la metodología y el análisis de los resultados obtenidos de la comunidad universitaria que participó en el programa de la plataforma en el área de Sistemas de Información

Nut drying of India cultivated in Campeche, México through direct solar technologies and under controlled conditions

 Las semillas de nuez de la India han sido usadas durante cientos de años en américa del sur gracias a sus múltiples propiedades beneficiosas y medicinales que posee. En este trabajo se presentan las características de la deshidratación de las semillas de nuez de la India utilizando un horno no convectivo a condiciones controladas de temperatura: 55°C y 65°C, con tiempos de secado de 1280 y 1080 minutos, respectivamente. Se utilizó además un secador solar directo tipo gabinete sin ventilación y secado a cielo abierto, obteniendo tiempos de secado promedios de 1020 y 1400 minutos, respectivamente. La temperatura en la cámara de secado más alta medida fue de 58.8°C. Las pruebas se realizaron en la Facultad de Ingeniería de la Universidad Nacional Autónoma de Campeche, en Campeche, México, ubicada a 19º51'00" de latitud norte, y 90º31'59" de longitud oeste, con un clima cálido-húmedo y valores promedio máximos de irradiancia solar de 970 W/m2. La humedad final de la nuez seca se osciló entre 6% y 4%. El tiempo de secado en gabinete fue más corto debido a que en convección natural se pueden alcanzar temperaturas más altas o muy cercanas a los 55 °C. Los resultados obtenidos muestran que el secado solar en gabinete es una tecnología simple y económica; se comprobó también la factibilidad técnica del secado solar de la semilla de marañón, obteniendo un valor agregado y alentando su producción en México. Palabras clave: Secador solar directo, Secado con temperaturas controladas, Convección natural, Cinética de secado

Desarrollo y análisis energético de destiladores solares de agua con convección natural y convección forzada

Desarrollo y análisis energético de destiladores solares de agua con convección natural y convección forzad

Temperature–air velocity association, experimental and modeling study of stevia leaves solar drying

Sugar is a natural high-calorie sweetener. Its excessive consumption is associated with health problems such as obesity, diabetes, heart disease, and degenerative issues. The stevia plant is a great natural substitute. It provides no calories and has medicinal properties such as oral antibacterial, hypoglycemic, and anti-hypertensive with a high nutritional value. In this work, the effects of temperature and air velocity in drying kinetics of stevia leaves were studied using a convective drier operating with air velocities (2, 3, and 4 m/s) and temperatures controlled (45 °C, 55 °C, and 65 °C). The highest drying rate was obtained at 65 °C and 4 m/s air velocity at 0.05 kg water/kg dry matter min. The experimental data were fitted to theoretical drying models to determine the best approach. It is found that the Page model gives a good fit for all experiments, with correlation coefficients ( R 2 ) > 0.9994. The equations to correlate this model's variables with air and temperature were determined. The results show that Δ E and glucoside values increase when temperature and air velocity increase

Improvements and Evaluation on Bitter Orange Leaves (Citrus aurantium L.) Solar Drying in Humid Climates

Dried, bitter orange leaves are widely used because of their nutritious and medicinal applications. As a result, many technologies have been used to accomplish its drying process. However, drying needs a long time and high energy demand, especially in humid climates. In this paper, bitter orange leaf drying was carried out using thermal and photovoltaic solar energy (integrated system, IS), eliminating the high humidity inside of the drying chamber to improve this process. A regular solar dryer (RD) was also used to compare the kinetics, mathematical modeling, and colorimetry study (as a quality parameter), evaluating both systems’ performances. The drying leaves’ weights were stabilized after 330 min in the RD and after 240 min in the IS, with a maximum drying rate of 0.021 kg water/kg dry matter∙min, reaching a relative humidity of 7.9%. The Page and Modified Page models were the best fitting to experimental results with an Ra2 value of 0.9980. In addition, the colorimetric study showed a better-preserved color using the IS, with an ∆E of 9.12, while in the RD, the ∆E was 20.66. Thus, this system implementation can reduce agroindustry costs by reducing time and energy with a better-quality and sustainable product, avoiding 53.2 kg CO2 emissions to the environment

Comparative study of different drying methods regard to the phenols and flavonoids content of dried Citrus aurantium L. leaves

Citrus Aurantium leaves contain compounds such as phenols and flavonoids that give it antioxidant properties. These properties can be affected by using any conservation method, such as drying. This study was carried out to determine the effects of different technologies of thermal drying on total phenols content (TPC) and the total flavonoids content (TFC) from the leaves of bitter orange (Citrus aurantium L.).  Solar drying was carried out under the open-air sun conditions and using two direct solar dryers; one with natural convection and the other with forced convection. TFC and TPC in equivalents of gallic acid (EGA) and quercetin (Q), respectively, of the ethanolic extracts of C. Aurantium were determined by using spectrophotometric techniques. The results showed maximum values of phenols for direct natural convection solar dryer (161.4 mg EGA/g MS) and minimum for shade drying (61.43 mg EAG/g MS). Regarding flavonoids, the highest values were obtained in the direct forced convection solar dryer (32.22 ± 1.6 mg QE/g MS), while in the open-air sun the lowest values were observed (11.72 mg QE/g MS). It is concluded, that the direct solar dryers are effective technologies to maintain the TPC and the TFC in the dry leaves of C. aurantium.Objective: To determine the effects of different thermal drying technologies on the total phenol and flavonoid contents (TPC) and total flavonoids (TFC) in sour orange (Citrus aurantium L.) leaves. Design/methodology/approach: Solar drying was carried out in outdoor sunny conditions using two direct solar dryers; one with natural convection, the other with forced convection. The total phenol and flavonoid contents in gallic acid equivalents (GAE) and quercetin (Q), respectively, of ethanolic extracts of C. aurantium were assessed with spectrophotometric techniques. Results: The results demonstrated maximum phenol values for the direct natural convection solar dryer (161.4 mg EAG/g MS) and minimum values for shade drying (61.43 mg EAG/g MS). As for flavonoids, the highest values were obtained in the direct forced convection solar dryer (32.22 ± 1.6 mg EQ/g MS), while the lowest was registered in the open air sun (11.72 mg EQ/g MS). Conclusions: Direct solar dryers are technologies effective for maintaining the phenols and total flavonoids content in dried leaves of C. aurantium.

Analysis of Energy and Environmental Indicators for Sustainable Operation of Mexican Hotels in Tropical Climate Aided by Artificial Intelligence

This study assessed the energy-use index and carbon-footprint performance of nine medium-category Mexican hotels (two–four stars) located in tropical-climate regions. The consumption of electrical and thermal energies of each hotel was collected during audits. Based on this, various scenarios of the partial replacement of the most energy-consuming devices were evaluated and synthesized in an expert model based on artificial neural networks. The artificial-intelligence model was designed to simultaneously associate the energy-consumption indicators, environmental impact, and economic savings of hotels based on their category, location, room number, number of existing electrical or thermal devices, and their percentage of substitution with more energy-efficient technologies. The model was used to compare the various partial-technology-substitution alternatives in each hotel that could reduce energy consumption and CO2 emissions based on the current values reported by the energy-use and environmental-impact indicators. The results of the proposed approach showed that even without making total replacements of equipment such as interior and exterior lighting or air conditioners, it was possible to identify configurations that could reduce the hotels’ energy use per room-year by 9–12%. In the environmental case, using more efficient technologies could reduce environmental mitigation. The proposed methodology represents an attractive option to facilitate the analyses and the decision making of administrators according to the needs of the type of hotel to improve its performance, which also affects the reduction in operating costs

Encuentro de Ciencias Básicas 1: retos frente a la deserción

Esta iniciativa surge al interior del Departamento de Ciencias Básicas de la Universidad Católica de Colombia, frente a preocupación emergente de los resultados obtenidos en las asignaturas impartidas por este departamento en áreas tales como: Matemáticas, Física, Estadística y Química, incidiendo como un factor determinante –no el único– en los índices de deserción del sistema de educación superior. Si bien, al interior de cada una de las instituciones de educación superior, se han gestado, propuesto y ejecutado diferentes estrategias que visan por la mejora en los resultados de pérdida y su impacto en la deserción, se evidencia la necesidad de trabajar conjuntamente, de manera interinstitucional, en propuestas para la generación de procesos de investigación que se centren en estos aspectos y que permitan transformaciones no solo en el hacer, sino en el ser de las asignaturas, su intencionalidad de formación, evaluación por competencias, perfil del estudiante y perfil del docente de Ciencias Básicas a nivel universitario, como factores determinantes en la aprobación y permanencia de los futuros profesionales en el sistema de educación superior. En este texto, editado por el Profesor Fredy R. Garay-Garay, el lector encontrará una muestra de los esfuerzos individuales que hacen las universidades frente al fenómeno de la deserción; no obstante, es apenas una invitación a continuar generando estrategias que garanticen procesos de enseñanza y aprendizaje de las Ciencias Básicas asertivos y que den cuenta de las necesidades contextuales de nuestras realidades.Editorial - Ciencias Básicas: retos frente a la deserción. Una estrategia de acompañamiento para aminorar la deserción en el Departamento de Ciencias Básicas de la Universidad de La Salle. El Lugar: interdisciplina y aprendizaje cooperativo. El programa de tutorías como medida para enfrentar la deserción estudiantil en el Departamento de Ciencias Básicas de la Universidad de La Salle. Factores de mortalidad académica en la asignatura Cálculo diferencial. Caso estudiantes de ingeniería de la Universidad Católica de Colombia. Internacionalización del currículo. Una experiencia en la asignatura Fundamentos de matemáticas Profesores integrales que forman y evalúan en ciencias por competencia