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Item type:Publication, The relationship between perceived learning, academic performance and academic engagement in virtual education for university students(Asian Online Journal Publishing Group, 2024-01-01)This study aimed to determine whether the three dimensions of academic engagement (cognitive, emotional and behavioral) were positively associated with perceived learning and academic performance. The participants were 301 university students from Lima. Structural equation models were used to test the proposed theoretical relationship between the variables. The results indicated that the model showed satisfactory fit indices (CFI = 0.956, TLI = 0.949, RMSEA = 0.043, SRMR = 0.062). Perceived learning was found to be predicted by cognitive engagement (β = 0.447, p < 0.01) and emotional engagement (β = 0.230, p < 0.05). However, there was no statistically significant relationship between behavioral engagement and perceived learning (β = 0.035, p = 0.840). On the other hand, academic performance was predicted by behavioral engagement (β = 0.393, p < 0.05) but not by cognitive (β = -0.164, p = 0.301) or emotional (β = 0.001, p = 0.991) engagement. The study highlights the importance of fostering academic engagement in university students to enhance both their academic performance and perceived learning. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Effect of hydrogen addition on soot maturity and volume fraction of ethylene non-premixed flames under different oxygen indices(Elsevier Ltd, 2024-01-01)An experimental and numerical study was carried out to analyze the effect of hydrogen addition on the fuel stream at various oxygen mole fraction of the oxidizer (oxygen index, OI), with emphasis on soot volume fraction and maturity. A target laminar coflow non-premixed ethylene flame was used as reference flame. Experimental evaluation of soot optical properties was carried out by measurements of two color absorption/emission signals, whereas detailed numerical simulations accounted for hydrogen tracking on the soot surface, allowing to define a H/C ratio that can be interpreted as representative of soot maturity. Results present an overall reduction on soot content and local flame emission with the H2 addition, while the opposite trend is encountered with the increase of OI. Changes are more pronounced close to the reaction zone near the flame edge, rather than the flame center. Under constant heat release rate conditions, temperature is mainly affected by the change of O2, whereas the addition of H2 results in a slight temperature variation. Both species intensify the combustion reactions, increasing the reaction rates and reducing the flame length. This effect is more noticeable for increasing the OI, than for the H2 addition for the cases studied. Carbon-to-soot conversion efficiency is reduced by H2 addition, as the soot oxidation processes become more predominant over soot formation processes, which are also affected by the change of temperature conditions. At 40% H2 addition, the carbon-to-soot efficiency remains approximately constant with the addition of O2. Overall, these trends are well-captured by the numerical simulations, although they underestimate soot volume fraction, specially for high OIs and near the flame wing. Finally, experimental results indicate that H2 prompts the soot maturation process, being more pronounced above 20% H2 addition, for high O2 contents, specially near the flame centerline. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Adapting the Technology Acceptance Model to Explore College Students' Intentions to Use Technology in Virtual Education(University of Barcelona, 2023-12-01)The use of technologies in educational contexts has been increasing due to the COVID-19 pandemic. However, the use of models that can explain a student's intention to use certain technologies has not been adequately researched, much less has it been possible to identify the validity of a model that maintained his factorial structure in different contexts. Therefore, this study seeks to adapt the technology acceptance model to Spanish, to be used with university students. Thus, a questionnaire was applied to 297 students belonging to a private university. The results indicate that the original factorial structure of the model is maintained when it is adapted to Spanish. Likewise, it was identified that there were no differences in the model according to the gender of the participant, which corroborates a factorial invariance of the model. Also, causal relationships within the model with the intention of using technologies are corroborated. We concluded that the technology acceptance model is maintained in a different context and can be used with university students to evaluate possible educational interventions in virtuality.