This present describes the results of the evaluation regarding the self-perception of personal and social attitudes acquired by university students from an engineer-ing faculty at a state university in Peru, in the context of virtual teaching and learning, declared by the health emergency by COVID-19; For which the follow-ing objectives were proposed, to determine the variation or impact that the self-perception of personal and social attitudes experienced, having as reference sce-narios, the academic semester with face-to-face teaching (academic semester 2019B) and then the academic semester developed totally virtual (2020A). An exploratory-descriptive research level was used, with a longitudinal non-experimental design, whose population and sample is made up of 674 and 761 students, in the 2019B and 2020A semesters respectively. The data collection in-struments were validated through Cronbach's Alpha, whose average results per academic semester were 0.960 and 0.958. After the investigation, it was found that there is no negative impact, due to virtual teaching; On the contrary, on aver-age, there was an increase in all levels of satisfaction, increasing the level very satisfied by 52.8% and the level satisfied by 3.25%.
The modeling and simulation of the catalytic dehydrogenation process of cyclohexanol in a fixed-bed catalytic reactor is presented, leading to finding the relationship between the effectiveness factor, the Thiele modulus, and the Weisz–Prater modulus of the catalyst particles with respect to their axial and radial position, for which the external conditions of concentration and temperature around each particle were previously obtained by applying the material and energy balances in the catalyst bed considering a two-dimensional pseudo-homogeneous model with radial diffusion. Subsequently, the material balances are established in terms of the molar flux density and conversion, the energy balance in terms of the heat flux density, Fick’s law, Fourier’s law, and the differential form of the effectiveness factor non-isothermal for each particle chosen based on the proposed meshing. The Thiele modulus calculated for most of the points is between 0.8 and 0.25, with a tendency towards the lower limit, and the theoretical values established as the limit for the Thiele modulus fluctuate between 0.4<Th<4. Therefore, the effectiveness factor analyzed is between 1 and 1/Th; this indicates that both the reaction speed as well as the diffusion speed within the particle have an influence on the intraparticle process, which is confirmed by the calculation of the Weisz–Prater modulus whose values are not <<1 nor >>1. The results obtained are subjected to a statistical test leading to analyzing whether there are significant differences both in the Thiele modulus, as well as in the effectiveness factor with respect to the radius and length of the reactor. It has been determined that there are no significant differences between the effectiveness factor with respect to the radius of the reactor; however, according to the analysis of variance, there are significant differences in the effectiveness factor with respect to length and, likewise, there are significant differences in the Thiele modulus and the Weisz–Prater modulus with respect to radius and length.
<span lang="EN-US">The article aims to analyze the perception of professional skills acquired in online learning among electronic engineering students. The research method is qualitative, with a descriptive approach, since it focuses on analyzing the statistics of the students' perception (frequency of satisfaction levels). Initially, the reliability of the instrument was determined using Cronbach's Alpha, obtaining a consistency coefficient of 0.967 and 0.932, in the academic semesters 2020-I and 2020-II, respectively. The data collected by means of a virtual questionnaire were processed in the SPSS software transformed into the Likert scale. The results obtained show a high perception among electronic engineering students in reference to the professional skills they have acquired. There is an increase in satisfaction from 66.78% (2020-I) to 74.26% (2020-II) between the first and second academic semester, despite the abrupt and unexpected change in the teaching-learning modality, in the second semester achieved a greater adaptation of this process. However, the online learning method should continue to be improved so that students perceive with greater satisfaction that they possess the skills to solve problems and cases related to the specialty) and the skills to master practical professional skills.</span>
<span lang="EN-US">This study analyzed the perception of Mechanical Engineering and Systems Engineering students in the process of evaluating teacher performance in online teaching due to the COVID-19 pandemic. This was descriptive-correlational research. The results showed that the Systems Engineering students performed a better perception with the class session management factor and low qualification to the didactic strategies factor. Likewise, the Pearson correlation test indicated a significant relationship (0.000) between the specific factors on the overall performance factor. The topic factor has the greatest strength on the qualification of the overall performance factor, with a constant Pearson's correlation of 0.964. The Mechanical Engineering students showed a better perception with the class session planning factor and low qualification to the didactic strategies factor. Likewise, the Pearson correlation test indicated a significant relationship (0.000) between the specific factors on the overall performance factor. The didactic strategies factor being the one that has the greatest strength on the qualification of the overall performance factor, with a correlation constant Pearson's of 0.983.</span>
The rheological behavior of aqueous solutions of polyvinyl alcohol at 4, 6, 8 and 10% by weight has been studied and evaluated at temperatures of 20, 25, 30 and 35 °C, using five non-Newtonian fluid models independent of time: Ferrys, Robertson-Stiff, Williamson, Sisko, and Ellis de Haven. The classical method consists in carrying out regression analysis. Using a comparative procedure of determination coefficients and variances, the model that most appropriately adjusts the experimental data to said model is selected. From the statistical point of view, the Sisko and Robertson-Stiff models present better regression parameters; to better specify the choice of the respective rheological model, a new factor has been proposed in the literature, the viscosity factor (VF), which expresses the relationship between apparent and dynamic viscosity. The analysis of this factor for the five models confirms the greater stability of the Ellis de Haven model in terms of the coefficient of variation of the VF. The value of VF fluctuates between 1 and 2 for all ranges of temperature and concentration experienced for vinyl alcohol solutions. As a consequence of the above, for the choice of the non-Newtonian fluid model associated with the rheology of the aqueous solution of polyvinyl alcohol, it is necessary to analyze the statistical parameters and the VF factor simultaneously.
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