Rainwater Harvesting for Agricultural Irrigation: An Analysis of Global Research

Within a context of scarce water resources for agriculture, rainwater harvesting constitutes a promising alternative that has been studied by different disciplines in recent years. This article analyses the dynamics of global research on rainwater harvesting for agricultural irrigation over the last two decades. To do this, qualitative systematic analysis and quantitative bibliometric analysis have been carried out. The results reveal that this line of research is becoming increasingly important within research on irrigation. Environmental sciences and agricultural and biological sciences are the most relevant subject areas. Agricultural Water Management, Physics and Chemistry of the Earth, and Irrigation and Drainage are the journals that have published the most articles on the subject. India, China, the United States (USA), South Africa, and the Netherlands are the countries that lead this line of research. Although significant progress has been made in this subject area, it is necessary to increase the number of studies on the capacity of rainwater harvesting systems to cover irrigation needs in different farming contexts, the factors that determine their adoption by farmers, the economic and financial feasibility of their implementation, and their contribution to mitigating global climate change

Crónica de las I Jornadas de Arqueología Social. Universidad de Cádiz. 16-17-23-30 noviembre y 1 diciembre

Crónica de las I Jornadas de Arqueología Social. Universidad de Cádiz. 16-17-23-30 noviembre y 1 diciembr

Verdades y mentiras de nuestra realidad, pretextos para manifestar nuestras voces. Secuencia didáctica para la producción de artículos de opinión

La presente investigación tuvo como propósitos determinar la incidencia de una secuencia didáctica, de enfoque comunicativo, en la producción de textos argumentativos, de los estudiantes de EBS, de la Escuela Normal Superior del Quindío (E.N.S.Q) de la ciudad de Armenia y reflexionar sobre las prácticas de enseñanza del lenguaje de una de las docentes durante dicha implementación. Para el logro de estos objetivos, se desarrolló una investigación de carácter cuantitativo, con enfoque cuasiexperimental, diseño pre-test-pos-test, que se complementó con el análisis cualitativo de las prácticas de la enseñanza de una de las docentes. El análisis de la información cuantitativa, se llevó a cabo en la producción textual de 34 estudiantes del grado noveno que fueron evaluados antes y después de la implementación de la Secuencia Didáctica. El instrumento diseñado para valorar ambas pruebas fue una rejilla de producción escrita, cuyas dimensiones fueron: Situación de Comunicación, Superestructura y Lingüística Textual. El análisis y contrastación de los resultados obtenidos se realizaron mediante la aplicación del estadígrafo T de Student, el cual permitió rechazar la hipótesis nula y validar la hipótesis de trabajo, esto es: La implementación de una secuencia didáctica de enfoque comunicativo, mejoró significativamente la producción de textos argumentativos, tipo artículo de opinión, de los estudiantes, de tal manera que estos dejan de ver la escritura como una tarea, para asumirla como un proceso que permite la forma de expresión de sus ideas. Respecto al análisis cualitativo, se identificó una transformación en la enseñanza del lenguaje escrito, de tal forma que, igual que los estudiantes, la profesora entendió la escritura como un proceso que, si parte de situaciones reales de comunicación y tiene destinatarios reales, puede convertirse en una herramienta potente para transformar el pensamiento y empoderar a los estudiantes como ciudadanos críticos

NOTAS SOBRE LA ANIDACIÓN DEL BIENPARADO COMÚN (NYCTIBIUS GRISEUS) EN EL VALLE GEOGRÁFICO DEL RIO CAUCA (CALI, COLOMBIA)

RESUMEN ∙ El Bienparado Común (Nyctibius griseus) habita desde el oeste de México hasta el norte de Argentina y Uruguay. A pesar de ser una especie común, la información existente sobre su historia natural es muy poca, especialmente sobre su comportamiento reproductivo. En este trabajo proveemos información detallada sobre su biología reproductiva basada en cuatro nidos monitoreados en Cali (Valle geográfico del Rio Cauca, Colombia). Los nidos eran concavidades en la parte superior de ramas truncadas, en cada una de las cuales se encontró un huevo blanco con manchas lila y marrón claro, distribuidas en toda la superficie. Durante la incubación, los padres permanecieron en el nido todo el día hasta las 18:34 ± 00:06 h (rango = 18:24–18:53 h), momento en el cual los adultos dejan desatendido el nido hasta el inicio de la sesión de incubación nocturna, la cual empezó a las 19:08 ± 00:07 h (rango = 19:00–19:15 h). El porcentaje de atención al nido fue de 95,03 ± 0,98% (n = 1 nido). El tiempo de permanencia del polluelo en el nido fue 46 días (n = 1 nido), con una tasa específica de crecimiento (K) de 0,124. La forma del nido, coloración del huevo y cuidado parental registrados aquí concuerdan con reportes previos para esta y otras especies del género. Sin embargo, la atención al nido y la tasa de crecimiento de los polluelos fueron mayores que la registrada en otros estudios.ABSTRACT ∙ Notes on the nesting of Common Potoo (Nyctibius griseus) in the valley of Rio Cauca (Cali, Colombia) Thee Common Potoo (N. griseus) is distributed from west Mexico to northern Argentina and Uruguay. Despite its wide distribution, information regarding its natural history is sparse, in particular concerning its nesting behavior. In this study, we present detailed breeding biology information based on four nests monitored in Cali, Colombia (Río Cauca valley). Nests were concavities on the top of truncated branches where one white egg with lilac and light brown speckles distributed over the entire surface was laid. Based on nest temperature loggers the parents incubated continuously through the day. The first foraging trip in the evening at 18:34 ± 00:06 h (range = 18:24–18:53 h) interrupted incubation until the start of the nocturnal incubation shift at 19:08 ± 00:07 h (range = 19:00–19:15 h). Nest attentiveness was 95.03 ± 0.98% (n = 1 nest). The nestling period lasted 46 days (n = 1 nest), and nestling growth rate (K) was 0.124. Nest shape, egg coloration, and parental care recorded in our study were consistent with previous reports for N. griseus and other species of the genus. However, nest attentiveness and growth rate of nestlings were higher compared with other studies

Sustainable Irrigation in Agriculture: An Analysis of Global Research

Irrigated agriculture plays a fundamental role as a supplier of food and raw materials. However, it is also the world’s largest water user. In recent years, there has been an increase in the number of studies analyzing agricultural irrigation from the perspective of sustainability with a focus on its environmental, economic, and social impacts. This study seeks to analyze the dynamics of global research in sustainable irrigation in agriculture between 1999 and 2018, including the main agents promoting it and the topics that have received the most attention. To do this, a review and a bibliometric analysis were carried out on a sample of 713 articles. The results show that sustainability is a line of study that is becoming increasingly more prominent within research in irrigation. The study also reveals the existence of substantial differences and preferred topics in the research undertaken by different countries. The priority issues addressed in the research were climatic change, environmental impact, and natural resources conservation; unconventional water resources; irrigation technology and innovation; and water use efficiency. Finally, the findings indicate a series of areas related to sustainable irrigation in agriculture in which research should be promoted

Enseñanza – aprendizaje del concepto de digestión humana en estudiantes del grado sexto

En este trabajo de investigación se identificaron los modelos explicativos más frecuentes y los obstáculos más comunes en el proceso enseñanza – aprendizaje del concepto de digestión humana, en estudiantes de sexto grado de básica secundaria, reconociendo la importancia de realizar una exploración de ideas previas de los estudiantes. Se realizó el análisis de la información empleando la herramienta ATLAS TI. Una vez identificados los modelos y los obstáculos se diseñó una unidad didáctica que permita mejorar los procesos de enseñanza - aprendizaje del concepto de digestión humana empleando estrategias metacognitivas y de lenguaje que faciliten su desenvolvimiento en la vida cotidiana y facilitar la solución de problemas en diferentes situaciones y contextos.Abstract : In this research the explanatory models frequently the most common obstacles in the teaching process were identified - learning the concept of human digestion, sixth grade students in junior high school, recognizing the importance of a preliminary exploration of student ideas. Information analysis was performed using the ATLAS IT tool. Learning the concept of human digestion and using metacognitive strategies to facilitate language development in your daily life and facilitate problem solving in different situations - Once identified models and obstacles a teaching unit that will improve the teaching was designed and contextsMaestrí

Study of the Influence of Tool Wear of Two Drill Bits Manufactured with Different Coating Processes in Drilling Carbon/Glass Fiber Hybrid Composite Bounded with Epoxy Polymer.

Fiber Reinforced Polymer (FRP) laminates have been widely used in engineering applications in recent decades. This is mainly due to their superior mechanical properties compared to single-phase materials. High strength-to-weight ratio, high stiffness, and excellent corrosion and fatigue resistance are some of the attractive properties of these materials. In large structures, drilling composite panels is a typical operation to assemble different parts with mechanical fasteners. This operation severely threatens the quality of the holes and, therefore, the joint strength. This study aims to study the wear evolution of two drill bits manufactured with different coatings processes (chemical vapor deposition and physical vapor deposition) and their influence on the quality of the holes. A carbon/glass fiber sandwich structure was selected as the workpiece, and a high-speed machine center was used to drill 1403 holes per tool in the laminates. The wear analysis of the tool was characterized in terms of flank wear and crater wear. For the delamination analysis caused by drilling, two types of delamination are identified (type I and II), and their values were quantified through the equivalent delamination factor (Fed). The results showed that, in general, the process used to apply the coating to the tool influences the wear mode and the delamination damage. The first tool, diamond coated with Chemical Vapor Deposition (CVD), showed more severe crater wear in the flank face and coating loss at the end of the cutting edges. However, with a Physical Vapor Deposition (PVD) coating process, the second tool presented flank wear more controlled but a more severe coating loss and edge rounding near the tip, producing further delamination. Using a supporting plate showed a reduction of delamination type I but not for delamination type II, which is related to edge rounding.This research was funded by Generalitat Valenciana under the project GV/2021/060

Multi-objective optimization analysis of cutting parameters when drilling composite materials with special geometry drills

The cutting tool geometry is strongly influencing damage induced during drilling of composite materials. The searching of new and optimum geometries reducing the damage on the laminates is still a challenge for the scientific community and industry. This study focuses on drilling woven CFRP laminates with four different tool geometries, analyzing the influence of the cutting parameters on the cutting forces and delamination damage. The work is divided in three phases; the first phase carries out a full factorial design of experiments conducted to quantify the significance of each process parameter as well as its interaction, on the generation of delamination at the hole entry and exit as well as the thrust force and torque. The second phase uses the response surface methodology (RSM) to establish the relationships between each output variable and the input variables based on ANOVA results. Finally, a multi-objective optimization strategy has been presented using the fitting equations to select optimum ranges of design parameters that can minimize collectively the aforementioned output variables. Ultimate objective is the process improvement toward negligible defects during drilling of woven CFRP composites.The researchers are indebted to the Ministerio de Economía y Empresa de España (Projects DPI2017-89197-C2-1-R and DPI2017-89197-C2-2-R) for the financial support which permitted to conduct part of this work as well as the Ministerio the Ciencia, Innovación y Universidades (Juan de la Cierva program with the reference FJCI-2017-34910

Hybrid FE/ANN and LPR approach for the inverse identification of material parameters from cutting tests

Accuracy of numerical models based in finite elements (FE), extensively used for simulation of cutting processes, depends strongly on the identification of proper material parameters. Experimental identification of the constitutive law parameters for simulation of cutting processes involves unsolved problems such as the complex testing techniques or the difficulty to reproduce the stress triaxiality state during cutting. This work proposes a methodology for the inverse identification of the material parameters from cutting test. Two hybrid approaches are compared. One of them based on FE and artificial neural networks (ANN). The other one based on FE and local polynomial regression (LPR). Firstly, a FE model is validated with experimental data. Then, ANN and LPR are trained with FE simulations. Finally, the estimated ANN and LPR models are used for the inverse identification of material parameters. This identification is solved as an optimization problem. The FE/LPR approach shows good performance, outperforming the FE/ANN approach.The authors acknowledge the financial support of this work to the Ministry of Science and Education of Spain (under project DPI2008-06746).Publicad