Universidad Nacional de Jaén

La limitada disponibilidad de energía eléctrica en zonas alejadas de la red pública motiva la evaluación del recurso eólico como alternativa para el abastecimiento energético local. En este contexto, la investigación tuvo como objetivo implementar y evaluar un prototipo de aerogenerador de eje vertical diseñado para operar con bajas velocidades de viento en el caserío Cruz Grande, distrito de Jaén. El estudio fue de tipo aplicado, con diseño experimental. Para el dimensionamiento se consideró una velocidad de viento de 2.72 m/s, una densidad del aire de 1.09 kg/m³ y un coeficiente de potencia de 0.35; bajo estas condiciones, para alcanzar una potencia de 12.15 W se obtuvo un rotor de 3.91 m², conformado por cinco aspas semicilíndricas de 0.50 m de diámetro. En la etapa de evaluación, mediante un sistema embebido con sensores se registró que, a una velocidad de 2.72 m/s, el rotor alcanzó 14 RPM y generó una potencia de 1.12 W. El análisis económico reportó un VAN de -S/. 5021.50, una TIR de -31 % y una relación beneficio-costo de 0.069, por lo que se concluye que el proyecto no es económicamente viable y no se recomienda su implementación a gran escala sin mejoras sustanciales en eficiencia o en las condiciones del recurso eólico.

El conocimiento y la práctica sobre donación voluntaria de sangre en trabajadores constituyen factores esenciales para promover participación responsable en salud.Objetivo: Determinar la relación entre el nivel de conocimiento y la práctica de donación voluntaria de sangre en trabajadores del Centro de Salud Morro Solar, Jaén, durante el año 2023. Materiales y métodos: Se trabajó un enfoque enfoque cuantitativo y diseño no experimental de tipo transversal. La muestra estuvo conformada por 101 trabajadores del Centro de Salud Morro Solar, seleccionados mediante muestreo no probabilístico por conveniencia Resultados: Se encontró que el 80,2% de los trabajadores alcanzaron un nivel alto de conocimiento sobre la donación voluntaria de sangre; sin embargo, solo 29,7% reportaron haberla practicado, frente a 70,3% que nunca lo hicieron. Este resultado evidencia una discrepancia entre conocimiento y acción, confirmada por un valor p = 0,9, lo que indica ausencia de asociación estadísticamente significativa entre ambas variables. Conclusiones: Se confirma que, aunque la mayoría de trabajadores posee un nivel alto de conocimiento sobre la donación voluntaria de sangre, este no se traduce en una práctica efectiva. La ausencia de asociación estadística entre conocimiento y acción evidencia la influencia de factores externos en la decisión de donar. También, las diferencias observadas por género y edad indican la necesidad de implementar estrategias educativas y motivacionales diferenciadas, orientadas a incrementar la participación en la donación voluntaria.

Many Malaysian Form 6 ESL students struggle to achieve the MUET Writing Paper standards, especially in linguistic correctness, lexical range, and grammatical control. Addressing this issue, the current study looked into the efficacy of incorporating artificial intelligence (AI) writing tools to improve students' writing skills. The study, which was based on the Technology Acceptance Model (TAM) and Constructivist learning theory, looked at how AI-supported writing instruction helps learners engage and develop knowledge. A quantitative quasi-experimental approach was used with 16 Lower Six ESL pupils at a Malaysian secondary school. Over the course of a six-week intervention, students conducted guided MUET-style writing activities with AI writing tools. Pre- and post-test writings were graded using an analytical rubric that corresponded to MUET descriptors for vocabulary, grammar, and mechanics. Performance differences were measured using descriptive and inferential techniques. The findings demonstrated considerable improvements in all writing components, with vocabulary showing the biggest increase, followed by grammar and mechanics. These findings show that AI systems may efficiently scaffold linguistic accuracy and lexical development using instant feedback and iterative revision. The study emphasizes the pedagogical potential of AI-assisted instruction in improving MUET-oriented writing performance and advocates for its incorporation into post-secondary ESL curriculum.

This study’s object is the approximation of a non-swept helical tubular surface by strips of sweeping surfaces (toruses) and the construction of sweeps of these strips. Approximating non-swept tubular surfaces by sections of sweep ones is a common practice in the design of various types of pipelines. A clear example of such an approximation is a sports ball whose outer shell consists of a certain number of separate elements. These elements must fit most tightly to the non-swept surface along its certain lines. Such lines are the lines of curvature. The task is to find these lines on the surface in order to subsequently analytically describe the torus strip, which is tangent to the non-swept surface along this line. As is known, there are two families of mutually perpendicular lines of curvature on surfaces. This paper considers a family of curvature lines that has advantages over another one in terms of approximation. This explains the results reported here. Their special feature is that in order to find the desired family of curvature lines, it is necessary to solve a differential equation. The solution to this equation was borrowed from a scientific article and used for further calculations. The results were visualized in the form of an approximated tubular surface with four and six strips. The sweeps of these strips were constructed for a tubular surface, in which the center line is a helical line r = 1. All dimensions are given in linear units. Instead of a circle generatrix, it is given by the radius of the cylinder a = 2, which hosts it, and the helical parameter b = 1.5 (step H = 9.4). The radius of the circle generatrix of the tubular surface of the original tubular surface in the approximated surface in the given examples is a polygon (square or equilateral hexagon).

This study's object is the process of cargo movement along the helical surface of an oblique open helicoid under the action of its natural weight. Such movement takes place in gravity chutes where the cargo descends under the action of its natural weight. Gravity (screw) chutes are used for transportation, separation, and enrichment of material. For a given surface, the problem is solved by composing differential equations of motion of a mathematical point, which is conditionally replaced by cargo, in projections onto the axis of the spatial coordinate system. If the surface is helical, then after stabilization of the motion, it is possible to find the parameters of the helical line – the trajectory of cargo movement. The task implies solving the inverse problem – constructing a helical surface along a given trajectory of cargo descent, which is a helical line. The results are attributed to the use of two accompanying trihedra of the trajectory with a common vertex and tangent orts to the trajectory, which coincide. One of them is a Frenet trihedron whose position is determined by the differential characteristics of the curve, and the second is a Darboux trihedron, the position of which depends on the point of the trajectory on the surface. In addition to the two coincident orts, the remaining four orts are located in the plane normal to the trajectory. The use of these two orts makes it possible to compose differential equations of motion of the load in projections onto a moving Darboux trihedron, one of the planes of which is tangent to the surface. A feature of the solution to the problem is that the trajectory of the load, i.e., the helix, is given by radius r of the cylinder on which it is located and velocity V of the load. Using these data, angle β of its ascent is determined. For example, at r = 0.5 m, V = 2.5 m/s, the angle of elevation is β = 20.7°. Then, a helical linear surface is constructed that passes through the given trajectory

This paper considers the process of segmenting an optoelectronic image acquired from an unmanned aerial vehicle based on the artificial bee colony algorithm. The principal hypothesis of this study assumes that the use of the artificial bee colony algorithm for segmenting an optoelectronic image acquired from an unmanned aerial vehicle could reduce segmentation errors of the first and second kinds. A method for segmenting an optoelectronic image acquired from an unmanned aerial vehicle based on the artificial bee colony algorithm has been improved, which, unlike known ones, involves the following: – initialization of the population of scout bees; – calculation of the objective function; – determining the best and promising positions; – calculation of the optimal value of the segmentation threshold; – image division into segments; – checking the stopping criterion; – bee migration; – acquisition of a segmented image. Experimental studies have been conducted on the segmentation of an optoelectronic image acquired from an unmanned aerial vehicle using a method based on the artificial bee colony algorithm. The visual quality of the segmented image makes it possible to conclude that segmentation using the artificial bee colony method is possible. Comparative analysis of segmented images (improved and known methods) indicates a clearer separation of the object of interest (car) using the method based on the artificial bee colony algorithm. The results of calculating segmentation errors of the first and second kind indicate a reduction in segmentation errors of the first kind by 9% and errors of the second kind by 7% when segmenting an optoelectronic image using the method based on the artificial bee colony algorithm

Chronic constipation represents a burden in the modern world and is most prevalent in the elderly. Constipation has been linked to alterations in the gut microbiota, especially to an increase in methanogenic microorganisms. Prebiotics and some probiotics have already shown beneficial effects in constipation through improving stool consistency and modulating the gut microbiota. In the current double-blind, randomized and parallel-arm clinical study, 24 subjects with constipation were supplemented with NextDext™, a dextran prebiotic, or ABB C24, a prebiotic-postbiotic combination of NextDext™ and ABB C22®, for two weeks to evaluate their effects on stool consistency (Bristol Stool Form Scale) and gut microbiome. The results showed a significant improvement in stool consistency after taking NextDext™ from constipated to normal (Bristol Scale) and a trend to improvement after ABB C24 supplementation. Consumption of NextDext™ increased the presence of some beneficial bacterial groups, such as Bifidobacterium longum and Roseburia hominis, and reduced the presence of microorganisms associated with constipation, such as Blautia obeum, Escherichia coli and Collinsella aerofaciens. Consumption of ABB C24 reduced the presence of Blautia obeum and the methanogenic bacteria Methanobrevibacter smithii, while increased beneficial Clostridium leptum and Coprococcus spp. There were no significant alterations in gut diversity indexes of richness and evenness, even if ABB C24 seemed to increase diversity in a greater number of volunteers. Although NextDext™ influenced more microbial groups and restored microbial groups associated with opioid use, the species modulated by ABB C24 reverted microbial alterations consistently reported in constipation, suggesting an added value of the postbiotic ABB C22®. Both could benefit different profiles of constipation sufferers. This study was registered in ClinicalTrials.gov: NCT06738433.

Edible mushrooms are well-known for their culinary and nutritional values. Additionally, they serve as a natural source of polyphenols, a group of bioactive compounds that significantly treat diseases associated with oxidative stress. The polyphenolic profile of mushrooms mainly consists of phenolic acids and flavonoids, whose chemical properties have attracted the attention of both the food and pharmaceutical industries. Consequently, methods for extracting polyphenols from mushrooms encompass conventional techniques (maceration and Soxhlet extraction) as well as innovative or green methods (ultrasound-assisted extraction, microwave-assisted extraction, pressurized liquid extraction, supercritical fluid extraction, enzyme-assisted extraction, and pulsed electric field extraction). Nonetheless, extraction with pressurized liquids and supercritical fluids is considered the most suitable method, as they function in a gentle and selective manner, preserving the integrity of the phenolic compounds. The use of mushroom-derived phenolic compounds in food and pharmaceutical formulations continues to face challenges concerning the safety of these extracts, as they might contain unwanted substances. Future applications should incorporate purification systems to yield highly pure extracts, thereby creating safe polyphenol carriers (for food and pharmaceutical products) for consumers.

ABSTRACT Assessment and institutional effectiveness (IE) continuous improvement efforts persist in being regularly ineffective in advancing an equity agenda. They often seem to be relegated to in-name-only endeavors, with gross mismatches occurring between intentions, actions, and impact. This disconnect results in the maintenance of unjust and inequitable status quo around student and educator success. How can and should assessment professionals responsible for institutional accountability demand and elicit justice in higher education’s ways of being so that students may thrive? How can assessment professionals change the landscape and culture of institutions, assess the meaningfulness and impact of equity-building work, and increase personal efficacy? This article uses the equity framework offered by Samuga_Gyaanam+Bheda (2022) and in the book Centering Equity in Assessment to share three case studies of infusing equity in and by assessment/IE work for educational success—in student support, in institutional programming, and on the curricular front—for practitioners to learn from and deploy.