Sistema Regional de Información
en línea para Revistas Científicas de América Latina,
el Caribe, España y Portugal

In this work, we study the approximate controllability of a control system with unbounded delay, non-instantaneous impulse, and non-local conditions. These results prove once again that the controllability of a linear system is preserved if we consider the impulses, the non-local conditions and the delays as disturbances of it, which is very natural in real life problems, never the critical points of a differential equation is exactly the critical point of the model that it represents, the same happens with the impulses, the delay and non-local conditions; they are intrinsic phenomena to the real problem, that many times they are not taken into account at the moment of carrying out the mathematical modeling. To achieve our result, we will use a technique developed by A. Bashirov et al., which does not use fixed point theorems. On the other hand, as the delay is infinite, we consider a phase space that satisfies the axiomatic theory propose by Hale-Kato to study retarded differential equations with unbounded delay.

Education is an essential condition to achieve the development of societies; therefore, it is necessary to guarantee its accessibility to the entire population and specially to disadvantaged sectors. This study analyzed the spatial accessibility of the population to public primary and secondary education centers in four peri-urban parishes in the canton of Cuenca. Two approaches were used for data processing. The first one was at the household level. As a result, information was obtained for 408 students. The second one is at the level of consolidated areas that formulates accessibility scenarios, relating travel costs in time and distance. These scenarios were modeled using tools based on Geographic Information Systems. As a result, the most used means of transportation is by foot (54.38%) and an average travel time of 13.5 minutes. Thus, the educational centers are close to each other even though they are peri-urban.

The construction industry involves complex systems that involve aspects such as workload and compliance with economic goals and project deadlines, among others. The management of these aspects determines that workers are subjected to work environments with high demands of physical and mental effort and prone to accidents. This research aimed to establish the trade-offs between occupational safety and health (OHS) management, efficiency, and workload in construction companies. Thirty construction companies in Ecuador associated with the construction chambers of Quito, Cuenca, and Guayaquil participated in the study. A questionnaire validated by experts was developed with three questions related to management in three dimensions: workload, efficiency, and safety. This research shows that companies trade OHS and workload for greater efficiency and profitability. Furthermore, the results of this study suggest the areas in which construction companies should implement improvements to achieve better management performance.

The objective of this research is to quantitatively evaluate the performance and security functionalities of the main firewalls based on free software currently available. Synthetic analytical and historical-logical scientific methods were used to analyze the literature related to the object of study and the experimental method was applied to verify the performance of the identified solutions. Metrics such as bandwidth, jitter and packet loss rate were used to measure the network performance of the firewalls using the iPerf3 tool. The htop tool was used to check the CPU and RAM consumption of the solutions. It was identified that Endian, Zentyal, pfSense, OPNsense, VyOS, IPFire and ClearOS provide a set of functionalities that contribute to increase the security in data networks. The results obtained showed that ClearOS has the best overall CPU and RAM consumption rates, which demonstrated its high efficiency in securing data networks with savings and optimal use of hardware resources. The identified findings facilitate decision making for the deployment of cyber-security tools in digital networks of organizations with scarce computational resources.

Valproic acid is an anti-seizure drug characterized by increasing brain levels of gamma-aminobutyric acid. Thus, it has been widely used to treat epilepsy and various neurological disorders. However, there are contradictory reports on its hepatotoxic effect. The objective of this work was to analyze the levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) enzymes in patients with neurological disorders treated with valproic acid. Thirty-eight patients treated with valproic acid and 10 individuals without treatment (control group) were studied. Whole blood samples obtained by venipuncture were processed. Aminotransferase levels were determined from the serum obtained by Molecular Absorption Spectrophotometry. The data was processed using the Mann-Whitney tests, Dunnett-ANOVA method to establish the statistical significance of the results. It was determined that there are no statistically significant differences between the serum levels of aminotransferases in both groups (treated with valproic acid and control) and the reference enzyme levels. Therefore, in this exploratory study, the pharmacological action of valproic acid did not reveal the induction of intrinsic or idiosyncratic reactions of importance on hepatic metabolism mediated by aminotransferases in the population studied.

Estimados lectores, Novasinergia comienza el quinto año de su vida, presentando su volumen 5, número 1. Publicar nuestro número seis meses antes de lo habitual ha sido un reto. Sin embargo, la madurez de nuestra revista, los árbitros, los autores y los lectores lo han hecho posible. Gracias a todos ustedes. Publicar el Vol. 4 No. 2 en diciembre de 2021 y el Vol. 5 No. 1 en enero ha supuesto una gran cantidad de trabajo. Hemos recibido artículos de múltiples disciplinas tanto como del extranjero y como de otras universidades del Ecuador. Se han procesado alrededor de 80 manuscritos y sólo 20 artículos han sido aceptados. Novasinergia ha cosechado una gran receptividad en sus lectores. No tenemos duda de que en conjunto con nuestros lectores recorremos el camino a consolidarnos como una importante revista científica multidisciplinaria en el Ecuador. Ha pasado 1 año, 9 meses y 20 días desde que la Organización Mundial de la Salud declaró la pandemia mundial. La batalla continúa con una ligera sensación de superación de la crisis. Se ha demostrado que, como raza, somos frágiles. Y debemos estar atentos, así como continuar cultivando nuestra generación de conocimientos formales para poder sobrevivir a las crisis que se avecinan. Muchas gracias. 

Debido a las consecuencias del cambio climático, las afectaciones del microclima y el efecto de isla calor en las ciudades, esta investigación busca evaluar el potencial de ventilación natural y aprovechamiento energético a escala urbana en Casco Antiguo de la Ciudad de Panamá. Indicadores como Potencial Climático de Ventilación Natural (PCVN), Horas Satisfechas de Ventilación Natural (NVSH) e Indicador de Consumo Eléctrico (ICE) fueron empleados. Para ello, se llevaron a cabo simulaciones energéticas dinámicas acoplando los programas ENVI-met y DesignBuilder. Un proceso de optimización a partir de estudios paramétricos y análisis de sensibilidad permite comparar materiales de construcción de envolventes, acristalamientos y horario de operación de ventanas con cantidad de horas de incomodidad térmica. Los resultados mostraron que el espacio construido no cuenta con un microclima beneficioso para ventilación natural (PCVN = 19.41%) y esta no favorece el confort térmico interior de las edificaciones (NVSH = 3.11%). El proceso de optimización mostró que los materiales de las envolventes no generan cambios significativos con respecto a horas de incomodidad térmica en modo pasivo a escala urbana; sin embargo, un aprovechamiento energético en modo activo se vio reflejado al implementar paredes y techos de material super aislado.

En este trabajo se presentan los resultados de la evaluación de la huella de carbono entre un vehículo con motor de combustión interna (VMCI) y uno con motor eléctrico a baterías (VEB), considerando el panorama energético de Ecuador. Para esto, se utilizó el análisis del Pozo-a-la-Rueda, determinando primeramente la matriz de generación de energía eléctrica en el país. Como caso de estudio se consideró un vehículo KIA Soul y KIA Soul EV (versión eléctrica). De esta manera, se usaron las características técnicas de ambos vehículos provistas por el fabricante, y consideraciones sobre la distancia de conducción, ruta del combustible, vida útil y reemplazo de baterías, así como emisiones debidas al chasis y la carrocería de los vehículos. Los resultados obtenidos indican que las emisiones de gases de efecto invernadero de un VMCI en Ecuador es 236.16 gCO2/km, mientras que el VEB emite 63.14 gCO2/km, lo que significa apenas un 27% de las emisiones producidas por el VMCI. Estos resultados representan un impacto positivo para reducir los índices de contaminación ambiental, indicando además la necesidad de sostener y acelerar el cambio de la matriz energética del país hacia una generación de energía limpia y sostenible.

The objective of this work was to analyze the implementation of the Science, Technology, Engineering, and Mathematics (STEM) educational approach for the teaching of Physics through project-based learning (PBL) in first-year high school students. Attention was focused on developing the disciplinary content and scientific skills proposed in the National Curriculum. The study involved 197 students and 11 teachers who teach Physics and Mathematics in a rural educational institution of fiscal support. The data collection technique used was a survey, and the questionnaire instrument included Likert scale items. The results showed the interest and need that exists in the educational field to implement this approach. The findings provide an overview of teachers' knowledge of STEM and the development of scientific skills in students through APB.

Se desarrolló un sistema de monitoreo meteorológico con el objetivo de alertar la presencia de temperaturas extremas que puedan ocasionar daños en cultivos por estrés térmico. El diseño y construcción está compuesto de dos módulos: el primero se instala en el cultivo y contiene una sonda DS18B20 que captura muestras de temperatura instantánea en un radio de 100 metros con una resolución de ±0.3°C y periodicidad de 20 segundos, también incorpora un algoritmo estadístico para validar cada medición antes de transmitirlo inalámbricamente al segundo módulo instalado en la vivienda del agricultor, el cual incorpora un menú de opciones en una pantalla táctil de 3.2 pulgadas que permite configurar limites térmicos de acuerdo al tipo de cultivo, entonces el sistema evalúa los datos y activa una alarma sonora al detectar la aproximación de una temperatura de estrés. Los resultados muestran una comunicación confiable en un radio de 19 km, con capacidad para respaldar datos históricos por 200 años convirtiéndolo en una fuente de información para futuros estudios. El prototipo demostró un alto grado de confiabilidad y utilidad por parte de los agricultores de la provincia de Chimborazo en Ecuador.