In this work, we have developed a versatile three-in-one single beam visible colorimeter for undergraduate laboratory courses. The battery and mains electricity supply (utility power), wired and wireless data logging, and 3D-printed components are three important highlights of the developed visible colorimeter. The system is based on a low-cost…

Photogates play an important part of many of today's physics laboratory experiments. They signal when an infrared (IR) beam is interrupted, thus supplying the experimenter with important timing information. Currently photogates use an infrared photodiode (IR transmitter) and a phototransistor (IR receiver). User-built photogates have a weakness…

This paper outlines a comprehensive teaching laboratory course program that centers on titration analysis, a timeless and essential technique in analytical chemistry spanning various disciplines, such as environmental science, medicine, and industry. In these fields, titration analysis is paramount for determining the concentrations of substances…

Undergraduates use a spike sorting routine developed in Octave to analyze the spiking activity generated from mechanical stimulation of spines of cockroach legs with the inexpensive SpikerBox amplifier and the free software Audacity. Students learn the procedures involved in handling the cockroaches and recording extracellular action potentials…

The use of radioactive isotopes in radioactive decay studies can be a problem due to the manipulation of radioisotopes, expensive equipment, and the difficulty of finding samples with a reasonable half-life (between 1 and 10 min). In this paper, we present a mock-up of a Geiger-Mu¨ller counter plus three fictitious radioisotopes. They form an…

The COVID-19 pandemic has significantly affected teaching processes worldwide, particularly in laboratory-intensive courses. To adapt, online experiments have been implemented globally. In response, educators at the Department of Chemistry, Chulalongkorn University, developed a Lab@Home chemistry experiment for their general chemistry lab course…

We designed and tested a 3D motion tracking system which displays acquired and derived data using augmented reality. This setup, based on a virtual reality headset and its controllers, is a relatively low-cost, high-precision, six degrees of freedom, high-speed, multiple-objects tracking device. This apparatus proves to be a very high-quality…

In a classical electronic laboratory, there is an experiment where a diode is connected in a series with a resistor and a variable DC voltage source in order to draw the characteristic I-V curve of the diode. Input voltage is gradually increased starting from 0 V, and the potential difference between the diode's terminals is read by using a…

This work reports the first use of rubber latex waste as the hydrophobic reagent for a low-cost, simple, and rapid fabrication of a paper towel-based experimental device (PTED) with a circular design of 5 mm to demonstrate the factors affecting chemical equilibrium; this serves as a user-friendly means for a laboratory experiment. The illustration…

We demonstrate that the simplicity of preparing functional microfluidic devices using 3D printing is well suited for undergraduate laboratories. Educational experiments utilizing non-paper-based microfluidic devices are often relegated to well-equipped, resource rich universities because traditional fabrication techniques require specialized and…

The study of buoyancy becomes very interesting when we measure the apparent weight of the body and the liquid vessel weight. In this paper, we propose an experimental apparatus that measures both the forces mentioned before as a function of the depth that a cylinder is sunk into the water. It is done using two load cells connected to an Arduino.…

Contribution: Prior studies indicate that students experimenting with characterization of optical planar waveguides use expensive ready-made prism couplers without clear understanding about construction of the entire optical measurement system. This paper presents a cost-effective modified bright-mode prism coupler that helps students learn…

Lab activities typically involve phenomena that are invisible to the naked eye. For example, in thermodynamics transfer of heat and temperature changes are perceived by the sense of touch or indirectly observed by the use of thermometers. New tools can be introduced to increase the opportunities for talking science. In this paper, we explore…

Portuguese schools hold important collections, most organised in the late nineteenth and early twentieth centuries. This scientific heritage, however, is still to be discovered. This article focuses on the creation, development, and role of natural history collections in Portuguese secondary schools, between the second half of the nineteenth…

In this laboratory experiment, students performed thermogravimetric analysis (TGA) coupled with mass spectrometry (MS) of herbaceous materials (TGA-MS) and learned to analyze mass-loss curves, as well as identify common fragmentation ions. The experiment is the first one to present the application of TGA in a currently relevant topic: biomass…