Mechanical analysis of Genoa 03 stirling engine

Due to the new technologies development based on renewable sources of energy, in recent years Stirling engines have become very important in the energetic sector. Many of them do not allow the use of fluid lubricants and, thus, the effect of friction losses is important. For this purpose, a mathematical model has been developed based on the force balance in the crankshaft using the pressure distribution in the cylinders. The aim of this work is to characterize the mechanical losses in a Genoa 03 Stirling engine using a numerical model and experimentally via the drag method. The results of this model have been compared with those obtained experimentally on Genoa 03 Stirling engine. In the experimental results, a proportional increase in friction torque due to the average pressure and the speed of the crankshaft is observed. The first of these is caused by an increase of dry friction forces and the second, by the viscous friction between the working fluid and the inner walls of the engine. Also in this paper, irreversible processes in a beta type Stirling engine have been investigated in order to highlight the impact of losses on mechanical power and its performance. This article develops the first study of the mechanical losses of Genoa 03 experimental Stirling engine, which has an output power of 3 kW. Although the model response follows the same trends as the experiments, those simplifications provide errors which become more significant as the engine speed increases.Ministerio de Economía y Competitividad ENE2013-43465-

Metodología Activa de Enseñanza Basada en el Aprendizaje por Proyectos (EBAP) en la Asignatura Superficies Complejas. Desarrollo y Aplicación de nuevo sistema de evaluación: Coevaluación Intergrupo

La innovación docente en la asignatura de Superficies Complejas tiene como línea fundamental de trabajo el desarrollo de la “Enseñanza basada en el Aprendizaje por Proyectos” (EBAP). Pretendemos el desarrollo y propuesta de aplicación de un nuevo sistema de evaluación: “Coevaluación Intergrupo” que haga partícipe al alumnado del proceso de evaluación de los proyectos. En concreto, se propone aplicar la Teoría de Expertones para la elaboración de un Instrumento de Valoraciones Difusas (IVD) que considere las opiniones proporcionadas por el profesor y alumnos en base a criterios de evaluación del proyecto de grupo. Creemos que la teoría de expertones proporciona un método de evaluación optimizado para la decisión de grupo multicriterios en el campo de la evaluación de proyectos de diseño industriales. No conocemos ningún trabajo científico en la investigación sobre innovación docente, que haya empleado esta metodología para la evaluación de trabajos de grupo orientados a la EBAP.The educational innovation in the course of Complex Surfaces takes as fundamental work line, the development of “Learning Based on Projects” (LBP). We seek the development and proposed of implementation of a new evaluation system "Intergroup co-evaluation”. In particular it is suggested to apply Experton's Theory for developing of a Fuzzy Valuations Instrument (FVD). It considers the opinions provided by the teacher and students based on evaluation criteria for the group project. We believe that the Experton´s Theory provides a method of optimized evaluation for multi-criteria group decision in the evaluation field of industrial design projects. We do not know any scientific work in the investigation in research on educational innovation, which has used this methodology for the evaluation of group work oriented to the LBP

Repotenciación del Sistema Informático de Denuncias Policiales para producir de manera eficiente información estadística en la Policía Nacional del Perú

El presente estudio propone una solución deseable, factible y viable al inadecuado proceso de producción de estadística en la Policía Nacional del Perú. Sobre el particular, se identificó como problema público que la información estadística producida por dicha institución, a nivel nacional, durante el periodo 2018 – 2019, no permite la transferencia de información, y el mapeo y/o georreferenciación de datos en tiempo real y de manera segura, tampoco entregar conocimiento útil y oportuno al usuario; por lo tanto, no genera valor público. El marco teórico y arquitectura del problema se sustentan en cuatro conceptos: Gobierno abierto, como paradigma para mejorar el desempeño de la gestión pública; Denuncia policial, como fuente esencial de la información estadística; Procesamiento de la información, como herramienta básica para generar conocimiento estadístico; y Estadística policial, como bien público. El tratamiento de la información se realizó mediante las técnicas de la observación, entrevistas, encuestas y revisión de documentos. El diseño del prototipo final de innovación identificó como factor causal el Inapropiado sistema informático, como problema reformulado Mejorar la eficiencia en la producción de información estadística policial, y como desafío de innovación ¿Cómo podemos mejorar la eficiencia en la producción de información estadística para generar valor público?; asimismo, mediante la herramienta design thinking se eligió como alternativa de solución la Repotenciación del Sistema Informático de Denuncias Policiales. Los actores involucrados, principalmente los expertos de la Dirección de Tecnología de la Información y Comunicación PNP, reconocieron la importancia de la propuesta y recomendaron su implementación. Como conclusión general, el trabajo de investigación sustenta la necesidad de implementar el proyecto final de innovación, soportado en su simplicidad teórica y práctica, y en su propósito de generar valor público.This study proposes a desirable, feasible and viable solution to the inadequate statistical production process in the National Police of Peru. In this regard, it was identified as a public problem that the statistical information produced by said institution, at the national level, during the 2018-2019 period, does not allow the transfer of information, and the mapping and / or georeferencing of data in real time and safe way, nor deliver useful and timely knowledge to the user; therefore, it does not generate public value. The theoretical framework and architecture of the problem is based on four concepts: Open government, as a paradigm to improve the performance of public management; Police report, as an essential source of statistical information; Information processing, as a basic tool to generate statistical knowledge; and Police statistics, as a public good. The information treatment was carried out through observation techniques, interviews, surveys and document review. The design of the final innovation prototype identified the Inappropriate computer system as a causal factor, as a reformulated problem Improving efficiency in the production of police statistical information, and as an innovation challenge How can we improve the efficiency in the production of statistical information to generate value public ?; Likewise, through the design thinking tool, the Repowering of the Police Complaints Computer System was chosen as an alternative solution. The actors involved, mainly the experts from the PNP Information and Communication Technology Directorate, recognized the importance of the proposal and recommended its implementation. As a general conclusion, the research work supports the need to implement the final innovation project, supported by its theoretical and practical simplicity, and its purpose of generating public value

A Fuzzy Delphi Consensus Methodology Based on a Fuzzy Ranking

Delphi multi-round survey is a procedure that has been widely and successfully used to aggregate experts’ opinions about some previously established statements or questions. Such opinions are usually expressed as real numbers and some commentaries. The evolution of the consensus can be shown by an increase in the agreement percentages, and a decrease in the number of comments made. A consensus is reached when this percentage exceeds a certain previously set threshold. If this threshold has not been reached, the moderator modifies the questionnaire according to the comments he/she has collected, and the following round begins. In this paper, a new fuzzy Delphi method is introduced. On the one hand, the experts’ subjective judgments are collected as fuzzy numbers, enriching the approach. On the other hand, such opinions are collected through a computerized application that is able to interpret the experts’ opinions as fuzzy numbers. Finally, we employ a recently introduced fuzzy ranking methodology, satisfying many properties according to human intuition, in order to determine whether the expert’s fuzzy opinion is favorable enough (comparing with a fixed fuzzy number that indicates Agree or Strongly Agree). A cross-cultural validation was performed to illustrate the applicability of the proposed method. The proposed approach is simple for two reasons: it does not need a defuzzification step of the experts’ answers, and it can consider a wide range of fuzzy numbers not only triangular or trapezoidal fuzzy numbers

Methodology for Olive Pruning Windrow Assessment Using 3D Time-of-Flight Camera

The management of olive pruning residue has shifted from burning to shredding, laying residues on soil, or harvesting residues for use as a derivative. The objective of this research is to develop, test, and validate a methodology to measure the dimensions, outline, and bulk volume of pruning residue windrows in olive orchards using both a manual and a 3D Time-of-Flight (ToF) camera. Trees were pruned using trunk shaker targeted pruning, from which two different branch sizes were selected to build two separate windrow treatments with the same pruning residue dose. Four windrows were built for each treatment, and four sampling points were selected along each windrow to take measurements using both manual and 3D ToF measurements. Windrow section outline could be defined using a polynomial or a triangular function, although manual measurement required processing with a polynomial function, especially for high windrow volumes. Different branch sizes provided to be significant differences for polynomial function coefficients, while no significant differences were found for windrow width. Bigger branches provided less bulk volume, which implied that these branches formed less porous windrows that smaller ones. Finally, manual and 3D ToF camera measurements were validated, giving an adequate performance for olive pruning residue windrow in-field assessment

Frequency measurement under non-sinusoidal conditions

Frequency measurement is an important issue in electrical engineering. Electric power systems have become increasing complex over the last decade. The use of distributed generation, the connection of non-linear loads and the presence of unexpected system faults are the main causes of frequency variations. In addition, power quality includes frequency as an important index. From a hardware instrumentation point of view, frequency measurement has different requirements: i.) Large power systems have slow frequency variation due to the high inertia of the overall network. This kind of problem requires frequency measuring methods capable of detecting small and also slow frequency variations. ii.) Small power systems can have frequency variation due to their reduced short-circuit power capacity. This type of problem requires fast methods with the capacity to detect large frequency variations. There are different groups of methods intended for frequency measurement. The methods can be compared in terms of computation and dynamic response, especially when the main voltage is disturbed. This research work focuses on frequency measurement under non-sinusoidal conditions. The paper studies the behaviour of a modified version of Sezi's method and its hardware implementation using a microcontroller. This system can be used for frequency measurement or as a synchronized sampling source in harmonic measurement (e.g. EN 61000-4-7) The fast time response of the system enables it to be used in almost all kinds of application: small and slow frequency variations; frequency triggering in power system protection and power quality index characterisation

Users’ perception of visual design and usefulness of a web-based educational tool

Our research has become increasingly aware of the relevance of visual design in understanding learners’ attitudes towards the use of virtual tools. Likewise, perceived usefulness is an essential antecedent of the cumulative impressions of and preferences for them. Therefore, the aim of this study is to investigate the main effects of visual design and usefulness on learning and productivity in the domain of web-based educational tools. A Structural Equation Modelling, specifically Partial Least Square (PLS), is proposed to assess the relationships between the constructs. Visual design and usefulness have a significant effect on the learner’s perception of the extent to which needs, goals and desires have been fully met, and, by extension, learning performance. Furthermore, higher expressive aesthetics reduces the impact of classical features on satisfaction

Effectiveness of a brief intervention on the resilience, mindfulness and empathy of nursing professionals

Objetivos: Evaluar la eficacia de una intervención guiada basada en la reducción del estrés y compasión, sobre la resiliencia, desgaste por empatía y atención plena de profesionales sanitarios. Metodología: Estudio cuasiexperimental con grupo control e intervención combinada multimodal impartido en 3 sesiones. Grupo control (n = 23), grupo experimental (n = 23).Recogida de datos: se hicieron 4 observaciones y se utilizaron las herramientas Escala Breve de Resiliencia, Inventario Friburgo de Mindfulness, Inventario de Desgaste por Empatía y datos sobre el perfil laboral y vida personal de las profesionales. Para analizar la relación entre variables se utilizó un modelo lineal general, la pruebas de chi cuadrado o de Fisher y análisis de regresión. Resultados: No se encontró un efecto significativo de la intervención evaluada en la puntuación obtenida en atención plena, resiliencia o empatía. El grupo control obtuvo mayor puntuación en atención plena cuando se relacionó con la unidad de trabajo no covid y la ausencia de estresores personales F (1,21)=16,081 p=<0,01, ŋ2=0,434. El perfil empático normal sin riesgo, fue significativamente mayor en unidades no covid frente a las covid en la primera evaluación (70% vs 30%, p=0,002). El perfil de baja resiliencia en técnicos de cuidados auxiliares de enfermería, fue mayor durante la última evaluación (72,2% vs 27,8%, p=0,003), momento que coincidió con un mayor número de pacientes hospitalizados por covid. Conclusiones: Factores personales y laborales (categoría profesional, la unidad de trabajo y presión asistencial) tuvieron más influencia en el bienestar psicológico de los profesionales, que la intervención realizada.Objectives: Assess the efficacy of a guided intervention based on stress reduction and compassion, related to resilience and compassion fatigue of healthcare professionals. Methods: Quasi-experimental study with a control and intervention groups, combining a multimodal intervention delivered in 3 sessions. Control group (n = 23), experimental group (n = 23). Data collection: 4 observations were made using the Brief Resilience Scale, Freiburg Mindfulness Inventory, Compassion Fatigue Inventory and data on the professional profile and personal life. In order to analyze the relationship between variables, a general linear model, the chi-square or Fisher test, and regression analysis were used. Results: No significant effect of the evaluated intervention was found on the score obtained in mindfulness, resilience or empathy. The control group obtained a higher score in mindfulness when related to the non-covid work unit and the absence of personal stressors F(1.21)=16.081 p=<0.01, ŋ2=0.434. The normal empathic profile without risk was significantly higher in non-covid units compared to covid units in the first evaluation (70% vs 30%, p=0.002). The profile of low resilience in auxiliary nurses was higher during the last evaluation (72.2% vs 27.8%, p=0.003), a moment in which a greater number of patients were hospitalized with covid. Conclusions: A higher influences on professionals psychological wellbeing was present with personal and job related factors (professional category, work place and healthcare pressure) than the intervention carried out

Efectividad de una intervención breve en la resiliencia, atención plena y empatía de profesionales de enfermería

Objectives: Assess the efficacy of a guided intervention based on stress reduction and compassion, related to resilience and compassion fatigue of healthcare professionals.Methods: Quasi-experimental study with a control and intervention groups, combining a multimodal intervention delivered in 3 sessions. Control group (n = 23), experimental group (n = 23). Data collection: 4 observations were made using the Brief Resilience Scale, Freiburg Mindfulness Inventory, Compassion Fatigue Inventory and data on the professional profile and personal life. In order to analyze the relationship between variables, a general linear model, the chi-square or Fisher test, and regression analysis were used.Results: No significant effect of the evaluated intervention was found on the score obtained in mindfulness, resilience or empathy. The control group obtained a higher score in mindfulness when related to the non-covid work unit and the absence of personal stressors F(1.21)=16.081 p=&lt;0.01, ŋ2=0.434. The normal empathic profile without risk was significantly higher in non-covid units compared to covid units in the first evaluation (70% vs 30%, p=0.002). The profile of low resilience in auxiliary nurses was higher during the last evaluation (72.2% vs 27.8%, p=0.003), a moment in which a greater number of patients were hospitalized with covid.Conclusions: A higher influences on professionals psychological wellbeing was present with personal and job related factors (professional category, work place and healthcare pressure) than the intervention carried out.Objetivos: Evaluar la eficacia de una intervención guiada basada en la reducción del estrés y compasión, sobre la resiliencia, desgaste por empatía y atención plena de profesionales sanitarios.Metodología: Estudio cuasiexperimental con grupo control e intervención combinada multimodal impartido en 3 sesiones. Grupo control (n = 23), grupo experimental (n = 23). Recogida de datos: se hicieron 4 observaciones y se utilizaron las herramientas Escala Breve de Resiliencia, Inventario Friburgo de Mindfulness, Inventario de Desgaste por Empatía y datos sobre el perfil laboral y vida personal de las profesionales. Para analizar la relación entre variables se utilizó un modelo lineal general, la pruebas de chi cuadrado o de Fisher y análisis de regresión.Resultados: No se encontró un efecto significativo de la intervención evaluada en la puntuación obtenida en atención plena, resiliencia o empatía. El grupo control obtuvo mayor puntuación en atención plena cuando se relacionó con la unidad de trabajo no covid y la ausencia de estresores personales F (1,21)=16,081 p=&lt;0,01, ŋ2=0,434. El perfil empático normal sin riesgo, fue significativamente mayor en unidades no covid frente a las covid en la primera evaluación (70% vs 30%, p=0,002). El perfil de baja resiliencia en técnicos de cuidados auxiliares de enfermería, fue mayor durante la última evaluación (72,2% vs 27,8%, p=0,003), momento que coincidió con un mayor número de pacientes hospitalizados por covid.Conclusiones: Factores personales y laborales (categoría profesional, la unidad de trabajo y presión asistencial) tuvieron más influencia en el bienestar psicológico de los profesionales, que la intervención realizada

Treatment of Sorghum Hybrid 85 P15 (Pioneer®) Seeds and their Influence on Melanaphis sacchari/sorghi Infestation

Context: Sorghum is a hosting plant of Melanaphis sacchari/sorghi. The control measures against the insect include the treatment of seeds. However, evaluation of the effect of insecticides on insect populations and the agronomic variables of the crop, are needed. Aim: To evaluate the influence of insecticides clothianidin, thiamethoxan, and imidacloprid during the treatment of hybrid 85 P15 (Pioneer®) seeds on the agronomic variables of the crop and infestation with M. sacchari/sorghi. Methods: The experiment was conducted in the School of Higher Studies in Xalostoc, Mexico, in 2018. Four doses of Poncho®, Cruiser® 5 FS, and Tools® TS in the treatment of hybrid 85 P15 (Pioneer®) seeds. A randomized block experimental design was applied, and the percentage of germination, M. sacchari/sorghi infestation, and agronomic parameters of the crop, were determined. Results: All the parameters achieved more than 90% of germination, which demonstrated that the products and doses did not affect this parameter. Likewise, no differences were observed in the treatments. The use of these insecticides in hybrid seeds had a little influence on aphid infestation. These treatments do not affect the content of chlorophyll, but other parameters, like Brix degree, and the fresh leaf weight were affected. Conclusions: The seed treatment does not reduce the percentage of germination of 85 P15 (Pioneer®) hybrids, a strong control was not achieved over infestation of aphids, but it did affect some agronomic variables; hence, evaluation of other hybrids is recommended