Proficiency with instrumental analysis via GC-MS is an important skill for chemistry students. The application of analytical techniques and fundamental theoretical principles to real-world problems can be valuable learning exercises for undergraduates which can also improve their analytical thinking skills. Xylitol is generally considered safe for…

A recent textbook research, carried out on a sample of 20 American physics textbooks, shows that the authors mainly keep the old definition of weight. According to that definition, the weight of a body is the gravitational force on the body. In such a conceptual frame, the objects in the spaceship are "apparently weightless" because they…

An undergraduate organic chemistry laboratory experiment that provides an introduction to the concepts and practices of photoredox catalysis is reported. While undergraduate-level photochemistry experiments typically place emphasis on analytical properties of catalysts rather than synthetic applications, this experiment showcases the power and…

Surface modification has been considered as a fundamental item in upper-division undergraduate and master courses. Thus, the development of experiments regarding processes and characterization of surface-modification phenomena is highly desired. In this article, we propose an electrochemical and computational study of widely used…

The research reported in this article represents a systematic, multiyear investigation of student understanding of the behavior of bipolar junction transistor circuits using a variety of different tasks to isolate and probe key aspects of transistor circuit behavior. The participants in this study were undergraduates enrolled in upper-division…

Resonance is an ubiquitous phenomenon present in many systems. In particular, air resonance in cavities was studied by Hermann von Helmholtz in the 1850s. Originally used as acoustic filters, Helmholtz resonators are rigid-wall cavities that reverberate at given fixed frequencies. An adjustable type of resonator is the so-called "universal…

An interdisciplinary laboratory experiment was designed and carried out on the basis of the photo/electrochromism of N,N'-bis(cysteine)pyromellitic diimide (BCPD), suitable for organic chemistry laboratory I and physical chemistry laboratory II students. In the organic chemistry laboratory, students synthesized BCPD and studied its…

An integrated pair of experiments has been developed to introduce undergraduate students to the ways in which electrochemistry can complement conventional synthetic chemistry involving redox reactions. Students first use cyclic voltammetry and linear scan voltammetry to characterize and quantify the products of the reaction between…

Drawing equipotential and electric field lines is an activity commonly found in most second-semester introductory physics courses. Unfortunately, current commercial lab offerings are expensive and do not afford the opportunity for real-time graphical visualization of the trends in voltage in different regions. In this brief article, we describe a…

Approximately 1 billion metric tons of food are lost each year due to mycotoxins (FAO 2013), secondary metabolites produced by fungi (Marin et al. 2013) that contaminate crops (Placinta, D'Mello, and MacDonald 1999) and threaten the health of domestic animals and humans (Sobrova et al. 2010). The fungus "Fusarium graminearum" produces…

The convenient synthesis of dihydroberberine by the reduction of berberine is described as an experiment for an upper-division undergraduate organic chemistry laboratory course. Students obtained up to 74% yield of the desired pure product without the use of chromatographic techniques. The antimicrobial activities of both compounds against…

An experimental procedure is presented that was developed by fifth-year chemical engineering and industrial chemistry undergraduates at the Federal University of Rio de Janeiro doing the discipline on Experimental Organic Technology. The aim of this study was to apply the solvatochromic effect of the dye Nile Blue chloride to the characterization…

The aims of teaching have evolved along with the society in which we live, from a teaching based in memory to a one that teaches to reason, in order to adapt to the accelerated rate of change imposed by the application of scientific discoveries in our society. We have a society in continuous learning, which requires the ability to reason in order…

In this study, a new model termed as "Flexible Inquiry Based Science Teaching", which is developed using the framework of the inquiry approach is proposed. Science teachers (n=2) who participated in the study were instructed on the inquiry approach and their in-class activity applications were examined. The "electricity module"…

To learn with data, students need "data" to explore. This can be deceptive--data-rich experiences typically involve much more than a straightforward science lab. Solving real problems with data means identifying authentic questions that are meaningful to students and provide a foundation for deep inquiry. Such situations often lend…