Cesar Gomez-Lahoz

This paper investigates the effects of a guaranteed prize incentive, in the form of an extra score, on student engagement in the quality assurance system (QAS) questionnaires employed for evaluating teaching performance at the University of Malaga. The incentive system aims to counteract declining participation rates and mitigate potential survey fatigue among students. Employing a comprehensive dataset spanning multiple academic years and subjects, the study utilized statistical analyses to evaluate the incentive’s effectiveness, considering its potential impact on both final grades and QAS questionnaire outcomes. The results demonstrate a substantial increase in participation rates, with over 85% of students acknowledging the motivating influence of the incentive. However, concerns regarding the compromise of anonymity arose among 40% of students, possibly linked to the physical presence of teachers during the verification process of the QAS questionnaire submission. The statistical analyses raise questions about the incentive’s influence on students’ final grades while indicating that the incentive system does not significantly affect the results of the QAS questionnaires. The study contributes valuable insights into the complexities of incentivizing student participation in teaching assessments within the higher education landscape. To the best of our knowledge, there are few publications that investigate the use of an additional score as an incentive for students’ participation in QAS questionnaires.

Lithium-ion batteries play an important role in our modern society as the main option to power portable electronic devices and electric vehicles. The growing demand for these batteries encourages the development of more efficient recycling processes, aiming to decrease the environmental impact of the spent batteries and recover their valuable components. In this paper, a combined hydrometallurgical-electrodialytic method is proposed for processing battery waste. In the combined technique, the amount of leaching solution is reduced as acid is generated via electrolysis. At the same time, the use of ion-exchange membranes and the possibility of electroplating allows for a selective separation of the target metals. Experiments were performed using LiCoO₂, which is one of the most used cathodes in lithium-ion batteries. First, 0.1 M HCl solution was used in batch extractions to study the kinetics of LiCoO₂ dissolution, reaching an extraction of 30% and 69% of cobalt and lithium, respectively. Secondly, hydrometallurgical extraction experiments were carried out in three-compartment electrodialytic cells, enhanced with cation-exchange membranes. Experiments yielded to a selective recovery in the catholyte of 62% of lithium and 33% of cobalt, 80% of the latter electrodeposited at the cathode.

Electrokinetic remediation (EKR) is probably the only feasible alternative to treat contaminated soils with low hydraulic conductivity. This technology is based on the application of an electric current between two groups of electrodes into the soil inducing several transport and transformation processes. As a result, the contaminants and water are transported toward the electrodes by electromigration, electroosmosis, electrophoresis, and diffusion. This study applied EKR to a real soil with a high concentration of lead. To evaluate the most suitable reagent to enhance the technique, semibatch extraction and EKR experiments at different scales were carried out. The enhancing agents used were acetic and nitric acids as weak and strong acids, respectively, and EDTA as a complexing reagent. A mathematical model for the comparison of the energy requirements at different scales was applied, showing that the defined parameter is a useful tool for the prediction of the energy requirements of EKR technique. The results indicate that the proposed methodology allows better knowledge about the behavior of contaminants under different experimental conditions.