Journal of Sciences and Engineering https://journals.cincader.org/index.php/sej <p><em>Journal of Sciences and Engineering</em> is a peer-reviewed, international and interdisciplinary research journal that focuses on all aspects of Sciences and Engineering. <em>Journal of Sciences and Engineering</em> publishes issues twice a year since 2017. </p> <p>All articles published are Open Access for readers and an article processing charge (APC) applies to papers accepted after peer review. </p> CINCADER Publishing en-US Journal of Sciences and Engineering 2523-9503 Influence of the virtual teaching modality on the desertion of students from the Computing and Informatics study program in the IESTP Laredo [Influencia de la modalidad de enseñanza virtual en la deserción de los estudiantes del programa de estudios de Co https://journals.cincader.org/index.php/sej/article/view/65 <p>The present research work has been developed with the purpose of evaluating the influence of the virtual teaching modality in the dropout of students from the study program of Computación e Informática in IESTP Laredo.</p> <p>The indicators used such as virtual learning, virtual learning systems, didactic units, terminal abilities, have been used to evaluate the degree of student dropout. The hypothesis was contrasted applying the pre-experimental design with pre-test and post-test. The result obtained from the significant coefficients of the respective indicators the pre test was 0,63; 1, 0,65; 0,78; 1; 0,82; 0,78 and the post test was 0,49; 0,61; 0,32; 0,66; 0,65; 0,58; 0,40. It was possible to determine that there is a contradiction within each of the indicators, since the results show that in each indicator at the end of the academic period 2020 - I, a lower participation of students was obtained in the development of the virtual learning process, which leads to dropout using this type of learning.</p> José Alberto Gómez Avila Franklin Alexis Díaz Díaz Elka Judiht Chávez Arana Juan Antonio Vega González Copyright (c) 2021 https://creativecommons.org/licenses/by/4.0 2021-01-07 2021-01-07 5 1 1 8 Perception on the improvement of attention service to the students under the basic conditions of quality for the institutional licensing of the Private University of Trujillo [Percepción sobre la mejora del servicio de atención a los estudiantes bajo las https://journals.cincader.org/index.php/sej/article/view/66 <p>This research work has been developed with the purpose of evaluating the improvement of the attention service to the students of the Private University of Trujillo with the fulfillment of condition I, component I.4 referring to information systems of the Basic Conditions of Quality (BCQ) to obtain institutional licensing. The indicators used as information systems that involve enrollment, payments, bibliographic material, virtual learning have been used to evaluate the improvement of the attention service to students. The hypothesis was contrasted by applying the pre-experimental design with pre-test and post-test. The result obtained from the significant coefficients of the respective indicators the pre-test was 0.42, 0.15, 0.71, 0.58, 0.35, 0.22, 0.42, 0 and the post-test was 0.93, 1, 0.88, 0.79, 0.88, 0.90, 0.83, 0.67. It was possible to determine that there is no contradiction within each of the indicators, since the results show that in each indicator after using the information systems required in the basic quality conditions, a better service for the students was obtained.</p> José Alberto Gómez Avila Franklin Alexis Díaz Díaz Elka Judiht Chávez Arana Juan Córdova Otero Juan Antonio Vega González Copyright (c) 2021 https://creativecommons.org/licenses/by/4.0 2021-01-07 2021-01-07 5 1 9 15 Cold cracking, microstructure, notch toughness, transverse and longitudinal hardness to the weld joint of P460NL1 steel [Fisuracion en frio, microestructura, tenacidad a la entalla, dureza transversal y longitudinal a la union de soldadura del acero P460N https://journals.cincader.org/index.php/sej/article/view/67 <p>Microstructural development, longitudinal HV10 hardness as transversal to the fusion zone and notch toughness in root and filling pass were evaluated at preheating temperatures of 100 °C, 140 °C, 180 °C, 220 °C and 260 °C in the weld joint of P460NL1 steel, by FCAW in root pass and for filling-finishing by means of the SAW process, the control of the start and interpass preheating temperatures was carried out by thermal blankets and digital pyrometer. The NDT of magnetic particles justify the acceptance or rejection of the specimens for the study. In selected points of the weld joint they showed the dependence of the hardness as a function of the microstructure. At room temperature, immediate cold cracking was observed. In the HAZ, the microconstituents generated areas of high hardness under the cord and areas of low hardness due to overturning, with the presence of Windmastatten ferrite, the increase in preheating determined the decrease and sometimes the absence of hardened structures. The profiles determined a decrease in hardness as the preheating temperature increased. Columnar grains with a high presence of WF ferrite in their different morphologies and FP (C) and refined areas with typical microconstituents were observed in the Fusion Zone. Homogeneity was evidenced with respect to notch toughness at all temperatures and the effect of passes on the longitudinal microstructure, which shows the benefit of the preheating temperature by reducing the hardness in critical areas and homogenizing the welded joint.</p> Hebert Gustavo Vizconde Poémape Osmar F. Armas joel A. Briceño Nilthon E. Zavaleta Norberto Damian Ñique Copyright (c) 2021 https://creativecommons.org/licenses/by/4.0 2021-01-22 2021-01-22 5 1 16 28 Current density and residence time in the electrocoagulation process and its influence on Fe2+ reduction [Densidad de corriente y tiempo de residencia en el proceso de electrocoagulación y su influencia en la reducción de Fe+2] https://journals.cincader.org/index.php/sej/article/view/68 <p>The present research work had as study variables the current density of 20, 40 and 80 mA/cm<sup>2</sup> and residence times of 10, 20, 40 and 60 minutes, within these evaluation parameters values ​​were taken of pH, conductivity and Fe<sup>2+</sup> removal percentage before and after the electrocoagulation process of artisanal acid mine drainage samples (AMD), the amount of AMD sample per test was 350 mL per test, from the results obtained it could be observed that For the current density of 80 mA/cm<sup>2</sup> and a time of 40 minutes, the highest percentage of removal was obtained (76.20%), likewise a minimum percentage of removal of 17.97% was obtained at 20 mA/cm<sup>2</sup>; The removal percentages are attributed to the effect of the current density of the electrocoagulation process, which allows increasing the initial pH values ​​of the effluent, which in turn allows the formation of precipitates and co-precipitates, in this case of Fe<sup>2+.</sup></p> Freddy Waldir Gómez Escobedo Jorge Edinson Gómez Escobedo Erick Alexander Choton Cipriano Dagner Marvin Castañeda Hilario César Pol Arévalo Aranda Hans Roger Portilla Rodriguez Aldo Roger Castillo Chung Alexander Yushepy Vega Anticona Copyright (c) 2021 https://creativecommons.org/licenses/by/4.0 2021-01-22 2021-01-22 5 1 29 37