"Sinorhizobium meliloti" is a bacterium of great agroeconomic importance because of its ability to fix atmospheric nitrogen in symbiotic association with alfalfa ("Medicago sativa") roots, and it is often used in model studies. We investigated the effects of exopolysaccharides (EPSs) in cell-to-cell and cell-to-surface…

Undergraduate laboratory courses, owing to their larger sizes and shorter time slots, are often conducted in highly structured modes. However, this approach is known to interfere with students' engagement in the experiments. To enhance students' engagement, we propose an alternative mode of running laboratory courses by creating some…

We developed a multipart laboratory experiment on the synthesis of free-standing hydrogels for junior to senior undergraduate students. In this experiment series that runs over the course of multiple 3-h lab periods, small everyday objects belonging to the students are reproduced as hydrogels by first creating negative templates in thermally cured…

The advanced organic chemistry experiments describe the preparation of fused six-membered lactams to isoxazole and isoxazoline by employing Ugi four-component reaction (U-4CR) and intramolecular nitrile oxide cyclization (INOC) synthetic sequence. The experiments were carried out in 28 h (overnight for U-4CR) and 2 h (for INOC) using commercially…

A four week laboratory experiment was designed on the basis of a modification of the Weiss-Cook reaction for the preparation of "cis"-1,5-dimethylbicyclo[3.3.0]octane-3,7-dione. In general, this very versatile organic reaction involves a two-step process reacting biacetyl with 2 mol of dimethyl-1,3-acetonedicarboxylate to form…

In the first-year general chemistry laboratory course, instrumental data collection involving sample quantification has often been limited to absorption spectroscopy due to the inaccessibility of emission techniques suitable for large enrollments and novice users. In this laboratory experiment, students explore the complementary techniques of…

Understanding the controls of the oxidation rate of iron (Fe) in oxygenated aquatic systems is fundamental for students of the Earth and Environmental Sciences as it defines the bioavailability of Fe, a trace metal essential for life. The laboratory experiment presented here was successfully developed and used during a third-year undergraduate lab…

Zinc oxide is a common additive in food, cosmetics, and medicines. Here, we describe the validation of methods to analyze two pharmaceutical samples containing ZnO--talc powder and dermal ointment--by ethylenediaminetetraacetic acid (EDTA) titration. The methods developed were implemented as a practical class to students of a Quantitative Analysis…

This paper presents an experimental lab designed for undergraduate students which focuses on soil science and chemistry. Students perform a series of tests to classify soil's phosphate retaining characteristics, texture, pH, organic matter content, and permeability with the addition of a novel soil amendment, Al Mg biochar. This lab has minimal…

In this paper, the inclusion of history and philosophy of science in science teaching is proposed with the goal of depicting pre-service primary teachers' perception of the role of historical experiments in learning science and the nature of science. In order to achieve this, a teaching-learning sequence was designed and conducted in the context…

Recognized as one of the most beautiful experiments of all time, the oil drop experiment performed by Robert Millikan and his graduate students (primarily Harvey Fletcher) is a standard in the repertoire of experiments performed by undergraduate physics students. However, "as a teaching lab it does not enjoy a good reputation for three…

The dynamic study of pendulum systems is considered an indispensable subject for physics and mechanics students in colleges and high schools. In this paper, a detailed methodology is given concerning the use of smartphones in pedagogical practical work for studying the dynamics of pendulum systems. Whereas, three aspects have been discussed…

During the coronavirus pandemic, there have been significant challenges in the remote teaching and demonstration of experiments, especially those that require laboratory testing equipment. With a desire to give students a feel for our materials laboratory on open days and allow them to gain a deeper understanding of what materials science and…

Here, we propose the use of magnetic levitation (MagLev) device, as a simple, cheap, and portable experimental technique to measure the density of diamagnetic materials in laboratory settings. We highlight the basics of a standard MagLev system for measuring the density of unknown diamagnetic materials/objects using permanent magnets, paramagnetic…

This paper demonstrates the use of a smartphone as a low-cost multi-channel optical fibre spectrophotometer suitable for physics laboratory classes. A custom-designed cradle and structure support were fabricated using 3D printing. The plastic optical fibres were arranged and inserted into the hole of the cradle to guide the light to the rear…