The Use of Active Methodologies for Teaching–Learning Systems in Telecommunications

This article discusses the adoption of the Problem Based Learning (PBL) and Project Based Learning (P2BL) approaches in the teaching/learning process of telecommunications. A computational environment was defined to combine these two approaches which focused on the teaching of courses that cover topics related to telecommunications systems. Newly graduated professionals face difficulties when entering the job market, as they have to deal with situations that are not experienced in the academic world. There is still a tendency to rely on traditional approaches for the teaching of telecommunications systems that have proved to be inefficient, as they are only concerned with content and not the applications that the student will require in the job market. The aim of this research is to investigate whether the adoption of PBL and P2BL in a computational environment can enhance student learning more effectively than the traditional teaching approach. This involved conducting an experiment in 7 undergraduate classes to compare the performance of the students that adopted PBL and P2BL with that of the students who were taught with the traditional approach. Data were collected on the grades obtained by the students in the courses and these were statistically analyzed. The results show that the adoption of PBL and P2BL led to the students achieving a 32% increase in performance. However, it was noted that the infrastructure of the institutions directly influences the way the approaches are adopted and, hence affects, the results.

     

Universal tracer monitored titrations

Titrations, while primarily known as the chemical rite of passage for fledgling science students, are still widely used for chemical analysis. With its many years of existence and improvement, the method would seem an unlikely candidate for innovation, yet it is desirable, in this age of autonomous sensing where analyzers may be sent into space or to the bottom of the ocean, to have a simplified titrimetric method that does not rely upon volumetric or gravimetric measurement of sample and titrant. In previous work on the measurement of seawater alkalinity, we found that use of a tracer in the titrant eliminates the need to measure mass or volume. Here, we show the versatility of the method for diverse types of titrations and tracers. The results suggest that tracers may be employed in all types of titrations, opening the door for greatly simplified laboratory and field-based chemical analysis.     

Cavitation Clusters in Lipid Systems: The Generation of a Bifurcated Streamer and the Dual Collapse of a Bubble Cluster

Several studies have reported the use of high-intensity ultrasound (HIU) to induce the crystallization of lipids. The effect that HIU has on lipid crystallization is usually attributed to the generation of cavities but acoustic cavitation has never been fully explored in lipids. The dynamics of a particular cavitation cluster next to a piston like emitter (PLE) in an oil was investigated in this study. The lipid systems, which are important in food processing, are studied with high-speed camera imaging, laser scattering, and acoustic pressure measurements. A sequence of stable clusters was noted. In addition, a bifurcated streamer was detected, which exists within a sequence of clusters. This is shown to originate from two clusters on the PLE tip oscillating with a 180° phase shift in time with respect to one another. Finally, the collapse phase of the cluster is shown to involve a rapid (~10 μs) two-stage process. These results show that the dynamics of cluster formation and collapse is driven by HIU power levels and might have implications in lipid sonocrystallization.