Characterisation of electrical power systems based on electrical curves and their properties

[Abstract]: Due to the proliferation of renewable energy systems, the study of voltage and frequency stability is a crucial aspect. Recently, this problem has been approached from a purely geometrical point of view with interesting results. The present work investigates the properties of the so-called electrical curves described by arbitrary voltage or current vectors in Euclidean spaces. Through the invariants of these curves, certain indices can be constructed to detect abnormal operation or irregular characteristics in electrical power systems. Different scenarios and examples have been solved in this work to support the proposed theory

Recycling of aggregates of Panasqueira mines as refractory lining of metal casting

Nas minas da Panasqueira (Covilhã, Portugal) acumulam-se montes de resíduos (agregados) provenientes da extração de tungsténio sem qualquer aplicação. Este trabalho pretende contribuir para implementar um novo uso para estes resíduos integrando-os como revestimento refratário no processo de moldação a verde da fundição de metais não ferrosos. Os resultados mostram o potencial do uso destes resíduos da fundição de metais não ferrosos.Over the years, in the Panasqueira mines (Covilhã, Portugal) were accumulated mountains of stones (wastes) has a result of the tungsten extraction without any application. This research aims to assist in the implementation of these wastes, using it as refractory lining in foundry (green moulding process), particular in foundry of non-ferrous metals. Experimental methodology consisted in mineralogical characterization (XRF and XRD), as well as the evaluation of the permeability to water vapour, fundamental aspect to be considered in the materials which constitute the moulds with refractory properties for metal casting. Two compositions have been considered and subsequently assessed by scanning electron microscopy (SEM), his behaviour as notferrous cast metal container, studying both the contact area and the contiguous zone of thermal diffusion. The results show that wastes can be used as a main component in the manufacture of refractory mould for casting non-ferrous metals moulded in green.Os autores agradecem o apoio técnico fundamental dos centros de investigação da Universidade de Granada, Grupo de investigação HUM 629, do CAST – Centro de Ciência e Tecnologias Aeroespaciais e do CMADE - Centro de Materiais e Tecnologias da Construção da Universidade da Beira Interior.info:eu-repo/semantics/publishedVersio

Improvement of learning through European educational projects

Proceedings TEEM 2020: Eighth International Conference on Technological Ecosystems for Enhancing Multiculturality.[EN]The purpose of this article is to set out the research plan for the doctoral thesis, which deals with the definition of a methodological guide for the successful use of digital technologies in education, especially in eLearning, taking as a reference European educational projects that have been successful in achieving an improvement in the teaching and learning process. We live in an increasingly digital society that requires citizens to be prepared to adapt to the needs of the moment and to solve the problems that arise. For this to be possible, the education system must be prepared to adequately train future citizens who will join a changing labor market. To this end, teachers must be trained and know how to carry out efficient educational projects that allow them to make the most of the potential of ICT in the classroom or in distance education. The situation experienced during the 2019-2020 school year with the COVID-19 pandemic has tested the education system and its ability to adapt to a situation where the use of distance education was required and where ICT was very much needed in most of the cases to bring education to the homes. These factors make it very necessary to work for a better teaching professionalization. Therefore, the main objective of this PhD work is to enable teachers to design their projects, involving electronic learning, in a more effective way. To achieve this, what better than to use the educational projects compiled in the Erasmus+ results platform, which allow the analysis of project typology, outcomes, topics and to see those that have been catalogued as a good practice or success story. This database will be a key tool to gather information together with the collaboration of the main actors of those projects that have been successful. A methodological guide would allow teachers and teacher trainers to know the key factors that help to achieve a good design of educational projects and allow an optimal use of ICT resources and the greatest impact on the teaching-learning process

Nutritional and biomass evaluation of a Megathyrsus maximus collection in a dry tropical climate in Colombia

Agronomic and nutritional parameters of a set of 28 accessions of Megathyrsus maximus established in Colombia during the rainy season were evaluated to identify accessions with differences in nutritional quality and characterize germplasm of M. maximus. ANOVA and multivariate analysis showed differences among accessions. Agronomic variables such as plant height, dry matter yield and green fresh weight were not correlated with nutritional variables. Flowering affected nutritional quality (neutral detergent fiber, acid detergent fiber and relative feed value). Flowering, fiber content, digestibility and crude protein content had the most influence on forage quality of M. maximus. The integral evaluation of biomass and nutritional parameters showed that the set of 28 M. maximus accessions contained 2 accessions with high nutritional quality and competitive biomass production. Heterogeneity of the collection in nutritional and agronomic assessments supports plant-breeding and offers alternatives for cattle producers in the tropics

Diagnostic Accuracy of Anthropometric Markers of Obesity for Prediabetes: A Systematic Review and Meta-Analysis

Introduction: Prediabetes is a significant public health concern due to its high risk of progressing to diabetes. Anthropometric measures of obesity, including body mass index (BMI), waist circumference (WC), and waist-to-height ratio (WHtR) have been demonstrated as key risk factors in the development of prediabetes. However, there is a lack of clarity on the diagnostic accuracy and cut-off points of these measures. Objective: To determine the diagnostic accuracy of these anthropometric measures for their most effective use in identifying prediabetes. Methodology: A systematic review (SR) with metanalysis of observational studies was carried out. The search was conducted in four databases: Pubmed/Medline, SCOPUS, Web of Science, and EMBASE. For the meta-analysis, sensitivity and specificity, together with their 95% confidence intervals (CI 95%) were calculated. Results: Among all the manuscripts chosen for review, we had four cross-sectional studies, and three were classified as cohort studies. The forest plots showed the combined sensitivity and specificity for both cross-sectional and cohort studies. For cross-sectional studies, the values were as follows: BMI had a sensitivity of 0.63 and specificity of 0.56, WC had a sensitivity of 0.59 and specificity of 0.58, and WHtR had a sensitivity of 0.63 and specificity of 0.73. In the cohort studies, the combined sensitivity and specificity were: BMI at 0.70 and 0.45, WC at 0.68 and 0.56, and WHtR at 0.68 and 0.56, respectively. All values are provided with 95% confidence intervals. Conclusions: This systematic review and meta-analysis evaluated the diagnostic accuracy of BMI, WC, and WHtR in identifying prediabetes. The results showed variations in sensitivity and specificity, with WHtR having the highest specificity in cross-sectional studies and BMI having improved sensitivity in cohort studies

Utilidad diagnóstica de la prueba de riesgo de la Asociación Americana de Diabetes para prediabetes y diabetes. Una revisión sistemática y metaanálisis

Introducción. Dado el aumento de los casos de prediabetes y diabetes mellitus tipo 2 (DM2) a nivel mundial, y al poco acceso de análisis de laboratorio en varios lugares, es necesario contar con la implementación de un método de detección simple, rápido y sin laboratorio: la prueba de riesgo de la Asociación Americana de Diabetes (ADA): el ADA test risk score (ADATRS). Objetivo. Realizar una revisión sistemática (RS) con metaanálisis sobre la utilidad diagnóstica del ADATRS para prediabetes y DM2. Materiales. RS con metaanálisis de estudios de pruebas diagnósticas. Se realizó la búsqueda en cuatro bases de datos: PubMed/Medline, SCOPUS, Web of Science y EMBASE. Se obtuvieron los verdadero positivos, verdaderos negativos, falsos positivos y falsos negativos de cada estudio. Se construyeron tablas de 2×2 con base en la información del artículo o de los autores. Así, se presentaron diagramas de bosque con un intervalo de confianza al 95% (IC 95%), tanto de la sensibilidad como especificidad en conjunto del ADATRS para ambos eventos de interés. Resultados. Los diagramas de bosque revelaron que la sensibilidad y especificidad para prediabetes fueron 0,91 (IC95%: 0,82–0,96) y 0,52 (IC95%: 0,36–0,67), respectivamente. Mientras que, para DM2, la sensibilidad y especificidad, combinados fueron 0,85 (IC95%: 0,71–0,93) y 0,56 (IC95%: 0,47–0,65), respectivamente. Conclusiones. Nuestra revisión sistemática y metanálisis de la literatura actual sugiere que el ADATRS puede ser útil como método de cribado para prediabetes y DM2, dado su alta sensibilidad. Sin embargo, existe mucha heterogeneidad y pocos estudios aun al respecto; por lo tanto, se necesitan más trabajos de investigación en diferentes poblaciones y con métodos más estandarizados para finalmente determinar la importancia clínica de este cuestionario como herramienta de cribado o diagnóstico para la prediabetes o DM2

Metabolically Obese Normal-Weight Phenotype as a Risk Factor for High Blood Pressure: A Five-Year Cohort

"Background: The metabolically obese normal-weight (MONW) phenotype has been considered a risk factor for different chronic diseases, but its role in high blood pressure (HBP) is still unclear. The aim of the study is to determine if the MONW phenotype constitutes a risk factor for hypertension in Peruvian adults belonging to a 5-year cohort. Methods: This is a retrospective cohort study. A secondary analysis from the database of the PERU MIGRANT study was carried out from the MONW and non-MONW cohorts; after a 5-year follow-up, the appearance of HBP was evaluated in the subjects of both cohorts. To assess the strength and magnitude of the association, a Poisson regression model (crude and adjusted) with robust variance was used. The measure of association was the relative risk (RR). Results: The incidence of HBP was 11.30%. In the multivariable analysis, subjects with the MONW phenotype had a 2.879-fold risk of presenting HBP in 5 years compared with those who were not MONW at the beginning of the study; this was adjusted for categorized age, sex, group, and state of smoker and alcohol drinker (RR: 2.055; 95% confidence interval (CI): 1.118 - 3.777; P = 0.020). Conclusions: The presence of the MONW phenotype doubled the incidence of HBP, even after adjusting for other covariates. However, studies in this field should continue. If these findings are confirmed, it should be considered that presenting an adequate weight for height should not be interpreted as a condition free of metabolic alterations, so screening for hypertension should be carried out regardless of w

The Fruit Intake–Adiposity Paradox: Findings from a Peruvian Cross-Sectional Study

"Due to the increase in obesity worldwide, international organizations have promoted the adoption of a healthy lifestyle, as part of which fruit consumption stands out. However, there are controversies regarding the role of fruit consumption in mitigating this disease. The objective of the present study was to analyze the association between fruit intake and body mass index (BMI) and waist circumference (WC) in a representative sample of Peruvians. This is an analytical cross-sectional study. Secondary data analysis was conducted using information from the Demographic and Health Survey of Peru (2019–2021). The outcome variables were BMI and WC. The exploratory variable was fruit intake, which was expressed in three different presentations: portion, salad, and juice. A generalized linear model of the Gaussian family and identity link function were performed to obtain the crude and adjusted beta coefficients. A total of 98,741 subjects were included in the study. Females comprised 54.4% of the sample. In the multivariate analysis, for each serving of fruit intake, the BMI decreased by 0.15 kg/m2 (β = −0.15; 95% CI −0.24 to −0.07), while the WC was reduced by 0.40 cm (β = −0.40; 95% CI −0.52 to −0.27). A negative association between fruit salad intake and WC was found (β = −0.28; 95% CI −0.56 to −0.01). No statistically significant association between fruit salad intake and BMI was found. In the case of fruit juice, for each glass of juice consumed, the BMI increased by 0.27 kg/m2 (β = 0.27; 95% CI 0.14 to 0.40), while the WC increased by 0.40 cm (β = 0.40; 95% CI 0.20 to 0.60). Fruit intake per serving is negatively related to general body adiposity and central fat distribution, while fruit salad intake is negatively related to central distribution adiposity. However, the consumption of fruit in the form of juices is positively associated with a significant increase in BMI and WC.

The Fruit Intake–Adiposity Paradox: Findings from a Peruvian Cross-Sectional Study

"Due to the increase in obesity worldwide, international organizations have promoted the adoption of a healthy lifestyle, as part of which fruit consumption stands out. However, there are controversies regarding the role of fruit consumption in mitigating this disease. The objective of the present study was to analyze the association between fruit intake and body mass index (BMI) and waist circumference (WC) in a representative sample of Peruvians. This is an analytical cross-sectional study. Secondary data analysis was conducted using information from the Demographic and Health Survey of Peru (2019–2021). The outcome variables were BMI and WC. The exploratory variable was fruit intake, which was expressed in three different presentations: portion, salad, and juice. A generalized linear model of the Gaussian family and identity link function were performed to obtain the crude and adjusted beta coefficients. A total of 98,741 subjects were included in the study. Females comprised 54.4% of the sample. In the multivariate analysis, for each serving of fruit intake, the BMI decreased by 0.15 kg/m2 (β = −0.15; 95% CI −0.24 to −0.07), while the WC was reduced by 0.40 cm (β = −0.40; 95% CI −0.52 to −0.27). A negative association between fruit salad intake and WC was found (β = −0.28; 95% CI −0.56 to −0.01). No statistically significant association between fruit salad intake and BMI was found. In the case of fruit juice, for each glass of juice consumed, the BMI increased by 0.27 kg/m2 (β = 0.27; 95% CI 0.14 to 0.40), while the WC increased by 0.40 cm (β = 0.40; 95% CI 0.20 to 0.60). Fruit intake per serving is negatively related to general body adiposity and central fat distribution, while fruit salad intake is negatively related to central distribution adiposity. However, the consumption of fruit in the form of juices is positively associated with a significant increase in BMI and WC.

The Fruit Intake–Adiposity Paradox: Findings from a Peruvian Cross-Sectional Study

Due to the increase in obesity worldwide, international organizations have promoted the adoption of a healthy lifestyle, as part of which fruit consumption stands out. However, there are controversies regarding the role of fruit consumption in mitigating this disease. The objective of the present study was to analyze the association between fruit intake and body mass index (BMI) and waist circumference (WC) in a representative sample of Peruvians. This is an analytical cross-sectional study. Secondary data analysis was conducted using information from the Demographic and Health Survey of Peru (2019–2021). The outcome variables were BMI and WC. The exploratory variable was fruit intake, which was expressed in three different presentations: portion, salad, and juice. A generalized linear model of the Gaussian family and identity link function were performed to obtain the crude and adjusted beta coefficients. A total of 98,741 subjects were included in the study. Females comprised 54.4% of the sample. In the multivariate analysis, for each serving of fruit intake, the BMI decreased by 0.15 kg/m2 (β = −0.15; 95% CI −0.24 to −0.07), while the WC was reduced by 0.40 cm (β = −0.40; 95% CI −0.52 to −0.27). A negative association between fruit salad intake and WC was found (β = −0.28; 95% CI −0.56 to −0.01). No statistically significant association between fruit salad intake and BMI was found. In the case of fruit juice, for each glass of juice consumed, the BMI increased by 0.27 kg/m2 (β = 0.27; 95% CI 0.14 to 0.40), while the WC increased by 0.40 cm (β = 0.40; 95% CI 0.20 to 0.60). Fruit intake per serving is negatively related to general body adiposity and central fat distribution, while fruit salad intake is negatively related to central distribution adiposity. However, the consumption of fruit in the form of juices is positively associated with a significant increase in BMI and WC