Chemical Vapor Deposition of Aluminum Oxide Thin Films Using a Low-cost Direct Liquid Injection Delivery System: An Educational Laboratory Experiment

Abstract The chemical vapor deposition is an attractive technique for the growth of thin films and coatings, mainly focused in applications of wear protection, corrosion and microelectronic. This technique has received special attention because allows to deposit thin films and coatings on complex substrates with irregular geometry. The laboratory experiment presented includes a delivery system based on an electro mechanical injector, denominated direct liquid injection, an updated variant of the classical chemical vapor deposition process with the aim of providing a more constant vapor phase for the process. Although it's numerous advantages, the high price for this equipment represents a barrier for the widespread of this technique in academic environments. The accessible materials used for this experiment setup allows building the setup in laboratories and facilities of universities and research centers focused on nanotechnology and materials science. The experiment setup has been successfully build and is used as a compressive hands-on tool to teach undergraduate, master and doctorate students the direct liquid injection chemical vapor deposition technique

Stable Continuous Production of γ-Valerolactone from Biomass-Derived Levulinic Acid over Zr–Al-Beta Zeolite Catalyst

© 2020 by the authors.The one-pot conversion of biomass-derived platform molecules such as levulinic acid (LA) and furfural (FAL) into γ-valerolactone (GVL) is challenging because of the need for adequate multi-functional catalysts and high-pressure gaseous hydrogen. As a more sustainable alternative, here we describe the transfer hydrogenation of LA to GVL using isopropanol as a hydrogen donor over a Zr-modified beta zeolite catalyst in a continuous fixed-bed reactor. A stable sustained production of GVL was achieved from the levulinic acid, with both high LA conversion (ca. 95%) and GVL yield (ca. 90%), for over at least 20 days in continuous operation at 170 °C. Importantly, the small decay in activity can be advantageously overcome by the means of a simple in situ thermal regeneration in the air atmosphere, leading to a complete recovery of the catalyst activity. Key to this outstanding result is the use of a Zr-modified dealuminated beta zeolite with a tailored Lewis/Brønsted acid sites ratio, which can synergistically catalyze the tandem steps of hydrogen transfer and acid-catalyzed transformations, leading to such a successful and stable production of GVL from LA.This research was funded by Spanish Ministry of Science, Innovation and Universities, grant number RTI2018-094918-B-C42, Regional Government of Madrid, grant number P2018/EMT-4344 (Biotres); and University Rey Juan Carlos (Young Researchers R&D Project ref. M2181—Biocavi).Peer reviewe

Analysis of a novel proposal using temperature and efficiency to prevent fires in photovoltaic energy systems

Fires in photovoltaic (PV) electrical systems are a real and serious problem because this phenomenon can have severe consequences for the safety of people and the environment. In some cases, fires result from a lack of maintenance or improper installation of PV modules. It is essential to consider prevention and continuous monitoring of the electrical parameters to minimize these risks, as these factors increase the temperature of the photovoltaic modules. The use of thermal analysis techniques can prevent hotspots and fires in photovoltaic systems; these techniques allow detecting and correcting problems in the installation, such as shadows, dirt, and poor-quality connections in PVs. This paper presents a case study of the implementation of thermal analysis in an installation of photovoltaic modules connected to a solar pumping system to identify the formation of hotspots through thermal images using an unmanned aerial vehicle (UAV). Here, a novel methodology is proposed based on the comparison of temperature increases concerning the values of short circuit current, open circuit voltage, and real efficiency of each PV module. In addition, an electrical safety methodology is proposed to design a photovoltaic system that prevents fires caused by hotspots, contemplating critical parameters such as photovoltaic power, number of photovoltaic modules, DC:AC conversion ratio, electrical conductor selection, control devices, and electrical protection; the performance power expected was obtained using standard power test conditions, including irradiance factor, photovoltaic module (PVM) temperature factor, and power reduction factor

Los vídeo tutoriales como apoyo al proceso de enseñanza aprendizaje y sus implicaciones pedagógicas en el diseño instruccional

Las nuevas tecnologías en el ámbito educativo exigen que sean diseñadas de manera adecuada con el apoyo del diseño instruccional y fundamentos pedagógicos de tal manera que los conocimientos a transmitir sean los apropiados.Se tiene una gran variedad de herramientas que apoyan al aprendizaje, siendo el video-tutorial las más utilizada por los estudiantes para resolver dudas y aprender de manera autónoma, sin embargo, en una encuesta se pudo comprobar que es una herramienta muy útil para los estudiantes, pero que al mismo tiempo se pierden en la búsqueda de información y los contenidos no son siempre los que se requieren, por lo que esta investigación es una propuesta para motivar a los docentes en el diseño adecuado de este multimedia educativo

Mental health knowledge and classroom experiences of school teachers in Aragon, Spain

Research shows that many mental disorders begin in childhood but are sometimes not diagnosed until later years. School-age children spend much of their time in schools and have daily interactions with school teachers.AimExamine school teachers’ experiences of mental disorders in school going children and adolescents and their associated mental health training needs.Method and sampleA descriptive cross-sectional study was carried out with teachers in Infant-Primary and Secondary Education-Baccalaureate schools.ResultsA convenience sample of 685 teachers responded to the online survey. Participants worked in both urban and rural areas and in Infant-Primary and Secondary Education-Baccalaureate schools. Over half of participants reported classroom experiences of learner mental disorders such as ADHD, anxiety, conduct disorders or autism. Most participants acknowledged a training need, both in recognition of symptoms of mental disorders and in care resources and processes. However, 80% of respondents reported having not received any training in this regard. Participant preferences for training included face-to-face or hybrid – combined online learning. Participants also considered the management of their own mental health to be deficient, therefore any training should incorporate personal mental health awareness and self-help strategies.ConclusionIn Aragón (Spain), teachers of children and adolescents with mental disorders, recognize a need for training in the identification of symptoms and other aspects of mental healthcare, such as availability and access to services. Protocols for early identification and referral would promote mentally healthy school environments and reduce stigma which could be a barrier to timely intervention. In addition, any training should include mental health self-care for teachers

Renewable Energies in the Agricultural Sector: A Perspective Analysis of the Last Three Years

Renewable energy arises as a tool for the supply of energy to the agriculture sector. Currently, there is a growing concern for the environment. This circumstance has led to technological progress in energy use in relation to natural resources and their availability for all productive sectors, including agriculture. The main objective of this work is to perform analysis from a bibliometric point of view and to analyze scientific advances in renewable energy and agriculture worldwide that have occurred in the last three years (2019–2021). The purpose of this study is to provide an overview of the last three years on the topic in order to contribute to the international scientific community, specifically towards collaboration between authors, institutions, and countries. A keyword analysis using community detection was applied to detect the five main clusters of this research and was largely dedicated to the following topics: renewable energy technologies in agriculture, bioenergy, sustainable agriculture, biomass energy, and the environmental impact of agriculture. The main countries found to be conducting research on renewable energy and agriculture include India, China, the United States, Italy, the United Kingdom, Poland, Indonesia, Germany, the Russian Federation, and Spain; the most important institutions conducting research in this area include the Ministry of Agriculture of the People’s Republic of China, the Tashkent Institute of Irrigation and Agricultural Mechanization Engineers at the National Research University in Uzbekistan, the Chinese Academy of Agricultural Sciences, and the Grupo de Investigação em Engenharia e Computação Inteligente para a Inovação e o Desenvolvimento in Portugal. These results may contribute to the identification of new research needs and therefore to the development of future directions of research on renewable energies in the agricultural sector

Health-related behaviors and symptoms of anxiety and depression in Spanish nursing students: an observational study

Background: Symptoms of anxiety and depression are prevalent among young adults and are a significant public health issue. College students are at a higher risk of experiencing poor mental health than other young people due to several factors, including moving away from home, financial pressures, heavy workload, poor time management skills, competitivity, new processes of socialization and insufficient coping mechanisms, among others. In addition, nursing students’ mental and physical health may also be affected by unhealthy lifestyle habits and health-related behaviors. Aim: To determine the prevalence of symptoms of depression and anxiety, and the association between these symptoms and health-related behaviors, in a population of Spanish student nurses. Methods: Cross-sectional study on a sample of 339 nursing students. We used the Hospital Anxiety and Depression Scale, the International Physical Activity Questionnaire-Short form, the Spanish Healthy Eating Index and an “ad hoc” questionnaire for sociodemographic variables. The association between psychological symptoms and health-related behaviors was analyzed through binary logistic regression models. Results: The prevalence of symptoms of depression and anxiety was 3.8% and 24.5%, respectively. Negative health-related behaviors were frequent, namely tobacco and alcohol consumption, suboptimal physical activity and diet. Moderate physical activity was associated with a lower probability of experiencing depressive symptoms. Symptoms of anxiety were related to a low level of physical activity, an unhealthy diet and alcohol consumption ≥2 times a week. Conclusion: Student nurses could benefit from the implementation of both physical and mental health promotion initiatives

Mental health knowledge and classroom experiences of school teachers in Aragon, Spain

BackgroundResearch shows that many mental disorders begin in childhood but are sometimes not diagnosed until later years. School-age children spend much of their time in schools and have daily interactions with school teachers.AimExamine school teachers’ experiences of mental disorders in school going children and adolescents and their associated mental health training needs.Method and sampleA descriptive cross-sectional study was carried out with teachers in Infant-Primary and Secondary Education-Baccalaureate schools.ResultsA convenience sample of 685 teachers responded to the online survey. Participants worked in both urban and rural areas and in Infant-Primary and Secondary Education-Baccalaureate schools. Over half of participants reported classroom experiences of learner mental disorders such as ADHD, anxiety, conduct disorders or autism. Most participants acknowledged a training need, both in recognition of symptoms of mental disorders and in care resources and processes. However, 80% of respondents reported having not received any training in this regard. Participant preferences for training included face-to-face or hybrid – combined online learning. Participants also considered the management of their own mental health to be deficient, therefore any training should incorporate personal mental health awareness and self-help strategies.ConclusionIn Aragón (Spain), teachers of children and adolescents with mental disorders, recognize a need for training in the identification of symptoms and other aspects of mental healthcare, such as availability and access to services. Protocols for early identification and referral would promote mentally healthy school environments and reduce stigma which could be a barrier to timely intervention. In addition, any training should include mental health self-care for teachers