Volume 10, issue 1

A lightning detection system based on a large-diameter Rogowski coil and an analog integrator was developed for wind turbine applications and is presented in this paper. To accurately detect lightning current, the Rogowski coil was designed with a lower cutoff frequency of 0.1 Hz. The analog integrator, comprising an inverting active integrator, and an amplifier, was used to restore the original waveform of the lightning current. Tests were conducted to verify the bandwidth of the system using alternating current, damped sinusoidal current, and a rectangular pulse. The system demonstrated a bandwidth of 0.1 Hz to 100 kHz, which is within the standard acceptable range. This lightning detection system offers a significantly lower cost compared to commercial alternatives, making it highly suitable for practical applications.

Extemporaneous omeprazole-based preparations are commonly used in hospitals; however, there are no validated studies about physicochemical stability. This study aimed to determine if temperature, luminosity, and the type of diluent affect the stability of omeprazole in the extemporaneous preparation. For stability, the methodology validated previously by our group was used. The 2k experimental design included Temperature (25ºC and 35ºC) and Luminosity (covered by light and 400 Lx) variables. Diluents were evaluated at five levels: 1) Citric acid + polyethylene glycol solution, 2) Polyethylene glycol solution, 3) Physiological saline solution, 4) Citric acid + polyethylene glycol solution + physiological saline solution, and 5) Polyethylene glycol solution + physiological saline solution. Minitab 18 software was used for data analysis, and the degradation kinetics were determined by linear regression. The optimal condition for physicochemical stability was a temperature of 25ºC covered by light (OM1-3h 49’, OM2-3h 2’, SSF-5h 8’, OM1SSF-2h 27’, OM2SSF-6h 23’). The diluent based on physiological saline solution provided more than five hours of shelf-life, and more than six hours, the diluent based on OM2 + SSF. However, the best option is physiological saline solution, considering the accessibility of the diluent. In conclusion, environmental conditions should be considered in extemporaneous omeprazole-based preparation since they are affected by temperature, luminosity, and type of diluent. Assessing shelf-life prior to administration is necessary to provide a safe and effective drug, avoiding the occurrence of side effects in patients.

The rapid expansion of digital universities across Africa addresses the need for scalable higher education solutions, but challenges such as limited physical infrastructure and high dropout rates persist. In digital learning environments, effective interaction with educational content is crucial for student success. This article explores the transformative role of chatbots integrated into digital university platforms, with a specific focus on their impact on learner-content interactions. Leveraging the frequent use of messaging applications and advances in Artificial Intelligence (AI), we examine how chatbot integration enhances student engagement, facilitates personalized access to core educational modules, and supports formative assessments to reinforce learning outcomes. Using the Rasa open-source framework and the Moodle Learning Management System (LMS), we present a model that not only delivers content efficiently but also provides an interactive learning experience through AI-driven dialogue systems. Furthermore, a comparison of the different AI tools used for educational chatbots will be presented, to determine the most suitable solutions for digital teaching. This analysis will consider various aspects such as efficiency, customization, flexibility and ease of integration of the tools into educational environments. This study highlights how chatbots can foster a more dynamic and responsive learning ecosystem, ultimately improving student retention and mastery of key concepts in digital universities. In this article, we explore the broader impact of chatbots on learner interaction with educational content, not just their integration. It also emphasizes student engagement and retention.