Use of Plackett–Burman and Box–Behnken designs to optimize bioelectricity production from winery residues

[Abstract]: This study aimed to estimate the bioelectricity production process using a vinasse solution through the application of Plackett–Burman and Box–Behnken designs. An electrochemical cell was constructed using Arduino to measure the potential difference between an anode and cathode immersed in a vinasse solution, which is a byproduct of wine production containing organic compounds and ions that undergo redox reactions. The Plackett–Burman design identified the most influential variables among eight previously selected (concentration of the electrolyte, pH, temperature, stirring, addition of NaCl, yeast dose and electrode:solution ratio). The results showed that the most influencing variables were the vinasse concentration and stirring and a peak of 306 mV could be observed for a 100 mL experiment. The third most influential variable regarding the process was NaCl addition, which showed its high influence at larger times. Based on these results, the Box–Behnken design was used to determine the possible ranges of variation of the independent variables (vinasse concentration, stirring and NaCl dose) to maximize the bioelectricity production. Therefore, with the combination of the intermediate concentrated vinasse (1:3 v/v ratio) and stirring, a peak of 431.1 mV could be observed when adding 2% NaCl after 15 min of the experiment. In what concerns the instant bioelectricity, measured after 1 min of the experiment, values up to 437.9 mV could be observed although yeast and/or NaCl are necessary at short times. This study provides insights into the bioelectricity production process from vinasse, contributing to the understanding and potential for sustainable energy generation.Centro Universitario de la Defensa en la Escuela Naval Militar ; PICUD-2022-0

An assessment on the efficiency of clothing with UV protection among the Spanish Navy school students

[Abstract] Concern about the harmful effects that ultraviolet (UV) rays have on the skin of people who are routinely exposed to solar radiation has driven the industry of skin protection creams, sunglasses and clothing. Spanish Navy personnel are subject to different levels of exposure depending on their rank and function. The objective of this research is to analyze the behavioral variables associated to the effects on the skin caused by UV rays, denoted by the combined effects of perceived susceptibility and perceived severity, on their decision to purchase and wear uniforms with UV protection. A confirmatory analysis using a structural equation modeling (SEM) was performed on a sample of 100 respondents. The model results revealed a strong mediating characteristic of the intention to use, variable associated with the exogenous variables. Attitude towards the use of clothing and social influence, as well as the exogenous variable clothing action planning, on the sun protective clothing use during tactical maneuvers. These relationships were significant with p-values close to zero. However, exogenous variables related to perceived susceptibility and perceived severity in exposure to sunlight did not represent a significant influence when mediated by self-efficacy in use. The results revealed the consequence of awareness about the importance of protecting oneself and the influence that usage habits can have on the military with respect to the decision to purchase uniforms with UV protection.The authors gratefully acknowledge the financial support provided by the Spanish Ministry of Science & Innovation under the I+D+i state program “Challenges Research Projects” (RTI2018-098900-B-I00) and the Regional Government of Castilla y León (INVESTUN/19/BU/004 and INVESTUN/22/BU/0001).Junta de Castilla y León; INVESTUN/19/BU/004Junta de Castilla y León; INVESTUN/22/BU/000

Scoping Review About Working Conditions and Health of Immigrant Workers in Spain

Fundamentos: La relación entre inmigración, trabajo y salud constituye uno de los retos más importantes en salud laboral y más concretamente en España por el importante incremento de proporción inmigrante acontecido en el mercado laboral. El objetivo de esta investigación es conocer la relación entre las condiciones de trabajo y sus efectos en la salud de trabajadores inmigrantes en España. Métodos: Revisión bibliográfica de artículos científicos originales en español e inglés Medline y Medes (1998-2012). Se revisaron los textos completos de los artículos incluidos. Resultados: Se incluyeron 20 estudios, 13 con metodología de investigación cuantitativa y 7 cualitativa. Los temas tratados abordaban problemas específicos de salud relacionados con el trabajo (principalmente lesiones por accidente de trabajo), incapacidad laboral y diferencias en condiciones de trabajo y empleo. Los hallazgos de los estudios mostraron mayor incidencia de lesiones por accidentes de trabajo, menores tasas de incapacidad laboral, mayor prevalencia de presentismo laboral, exposición a factores psicosociales y precariedad laboral en la población inmigrante. Conclusiones: A pesar de la singularidad del proceso demográfico migratorio, los problemas de salud y determinantes identificados no difieren de los referenciados en otros países, en otros contextos y en otros momentos.Background:The relationship between immigration, work, and health is one of the most important challenges in occupational health at current, particularly in Spain, by the significant increase in the migrant workers in the labor market occurred. This investigation aims to know the relationship betwen working conditions and their effects on migrant workers. Methods: Scoping review of scientific papers on this topic at the Medline and Medes databases in Spanish and English (1998-2012). The articles included were full text reviewed. Results: 20 studies were included, 13 with quantitative methodology and 7 qualitative. The topics address specific health problems related to work (primarily occupational accidents), disability, and differences in working conditions and employment. The findings of the studies show a higher incidence of injury accidents, lower rates of disability, higher prevalence of work presenteeism, exposure to psychosocial factors, and precariousness. Conclusion: Despite the uniqueness of the demographic process migration happened in Spain, health problems and determinants identified no different from those referenced in other countries, in other contexts and in other times

A Low-Cost Luxometer Benchmark for Solar Illuminance Measurement System Based on the Internet of Things

Natural illumination has an important place in home automation applications. Among other advantages, it contributes to better visual health, energy savings, and lower CO2 emissions. Therefore, it is important to measure illuminance in the most accurate and cost-effective way. This work compares several low-cost commercial sensors (VEML 7700, TSL2591, and OPT3001) with a professional one (ML-020S-O), all of them installed outdoors. In addition, a platform based on the Internet of Things technology was designed and deployed as a centralized point of data collection and processing. Summer months have been chosen for the comparison. This is the most adverse situation for low-cost sensors since they are designed for indoor use, and their operating range is lower than the maximum reached by sunlight. The solar illuminance was recorded every minute. As expected, the obtained bias depends on the solar height. This can reach 60% in the worst circumstances, although most of the time, its value stays below 40%. The positive side lies in the good precision of the recordings. This systematic deviation makes it susceptible to mathematical correction. Therefore, the incorporation of more sensors and data that can help the global improvement of the precision and accuracy of this low-cost system is left as a future line of improvement.The authors gratefully acknowledge the financial support provided by the Spanish Ministry of Science & Innovation under the I+D+i state program “Challenges Research Projects” (RTI2018-098900-B-I00) and the Regional Government of Castilla y León (IN-VESTUN/19/BU/004 and INVESTUN/22/BU/0001). Diego Granados López also thankfully acknowledges the financial support from the Junta de Castilla-León (ORDEN EDU/556/2019)

Pixel-Based Image Processing for CIE Standard Sky Classification through ANN

Digital sky images are studied for the definition of sky conditions in accordance with the CIE Standard General Sky Guide. Likewise, adequate image-processing methods are analyzed that highlight key image information, prior to the application of Artificial Neural Network classification algorithms. Twenty-two image-processing methods are reviewed and applied to a broad and unbiased dataset of 1500 sky images recorded in Burgos, Spain, over an extensive experimental campaign. The dataset comprises one hundred images of each CIE standard sky type, previously classified from simultaneous sky scanner data. Color spaces, spectral features, and texture filters image-processing methods are applied. While the use of the traditional RGB color space for image-processing yielded good results (ANN accuracy equal to 86.6%), other color spaces, such as Hue Saturation Value (HSV), which may be more appropriate, increased the accuracy of their global classifications. The use of either the green or the blue monochromatic channels improved sky classification, both for the fifteen CIE standard sky types and for simpler classification into clear, partial, and overcast conditions. The main conclusion was that specific image-processing methods could improve ANN-algorithm accuracy, depending on the image information required for the classification problem.Regional Government of Castilla y León under the “Support Program for Recognized Research Groups of Public Universities of Castilla y León” (BU021G19) and the Spanish Ministry 595 of Science and Innovation under the I + D + i state program “Challenges Research Projects” (Ref. RTI2018-098900-B-I00). Diego Granados López expresses his thanks for economic support from the Junta de Castilla-León (PIRTU Program, ORDEN EDU/556/2019)

Lista de especies de los escarabajos fruteros (Melolonthidae: Cetoniinae) de Colombia

The particular characteristics of both adults and larvae, have led some authors to consider them an independent group within the Scarabaeidae family. Several Latin American authors follow the proposal of Endrodi (1966), who considers the Cetoniinae a subfamily within the Melolonthidae family. The suprageneric revision of Krikken, (1984), elevates this group to the level of the Cetoniidae family, including the subfamilies Cetoniinae, Trichinae and Valginae who make up a monophyletic group related to the Rutelinae-Dynastinae (Morón & Deloya, 1997). Although this proposal is followed by the American school, there is not yet a consensus between the Latin American and American specialists. In this work the Latin American proposal is adopted.Las características particulares tanto de los adultos como de las larvas, han llevado a algunos autores a considerarlos como un grupo independiente dentro de la familia Scarabaeidae. Varios autores latinoamericanos siguen la propuesta de Endrodi, (1966), quién considera a los Cetoninos, como una subfamilia dentro de la familia Melolonthidae. La revisión supragenérica de Krikken, (1984), eleva este grupo a un nivel de familia Cetoniidae, incluyendo en ella a las subfamilias Cetoniinae, Trichinae y Valginae las cuales conforman grupo monofilético relacionado con los Rutelinae-Dynastinae (Morón & Deloya, 1997) Esta propuesta es seguida por la escuela americana, sin embargo aún no existe un consenso entre los especialistas latinos y americanos. En el presente trabajo se adopta la propuesta latinoamericana

Enhancing LoRaWAN scalability with Longest First Slotted CSMA

Financiado para publicación en acceso aberto: Universidade de Vigo/CISUGCompelling features such as low power consumption and low complexity make LoRaWAN one of the most promising technologies to provide long-range connectivity to resource-constrained devices. However, LoRaWAN suffers from limited scalability since it uses an Aloha-based protocol for accessing the channel that causes a huge amount of frame collisions when the number of devices (or the network load) is high. This paper presents LFS-CSMA, a new medium access control mechanism that enhances the scalability of LoRaWAN networks by just combining the well-known slotted Aloha and CSMA schemes in a novel manner. With LFS-CSMA, longer frames are transmitted earlier within a given timeslot. Thus, devices with short frames to be transmitted can check the channel availability before sending them and avoid collisions if they detect an ongoing transmission. Performance results show that LFS-CSMA causes far less collisions than traditional MAC mechanisms, thus improving the scalability of LoRaWAN networks significantly.Agencia Estatal de Investigación | Ref. PID2020-113240RB-I00Xunta de Galici

Design Sprint: Enhancing STEAM and Engineering Education Through Agile Prototyping and Testing Ideas

[Abstract] Creating project-based learning experiences in the classroom where students learn in a team to solve complex problems and to develop creative and critical thinking is a challenge. Design Sprint (DS) is an agile methodology (implemented in 5 days) with the goal of creating innovative design based on user needs (User Experience). The objective of this work was to develop an Engineering Drawing classroom experience linked to the context of the current COVID-19 pandemic with the Design Sprint methodology. The experience had to involve the integration of theory and practice, the application of knowledge, the development of both hard and soft skills, and the empowerment of students to conduct research. 56 first-year students following three STEAM degrees at the University of A Coruña participated in this experience. The activities were designed for both face-to-face and remote learning. Microsoft Teams and Moodle were used for tutoring and for monitoring student progress. The Moodle Workshop tool was used for the evaluation of the prototypes that were developed and the projects were evaluated by video. The students defended their projects through a presentation in lightning talk format (Ignite). Evaluation rubrics were used following a triple approach: co-evaluation, hetero-evaluation and self-evaluation. The 3D design of the projects was developed with Autodesk software. A total of 18 projects were developed. Once the projects were completed, a survey was administered to evaluate the levels of student satisfaction. The survey results were very positive. The Design Sprint projects also showed positive effects on grades. The Design Sprint method has promoted an interactive learning environment. In addition to its simplicity, a further advantage of DS method is that all student dedication is planned. Students were therefore less likely to feel overloaded, all of which helps with better time management. The DS methodology is multipurpose, so it can be applied to various fields and subjects