One of the principles of sustainable development is to replace chemicals traditionally derived from oil with alternative, renewable materials. For example, phenol and phenol derivatives currently used in the manufacture of wood adhesives can be replaced (at least in part) by biopolymers extracted from biomass. In this work, pine bark (a renewable…

In this article a potentiometric method for reducing sugar quantification is described. Copper(II) ion reacts with the reducing sugar (glucose, fructose, and others), and the excess is quantified using a copper wire indicator electrode. In order to accelerate the kinetics of the reaction, working conditions such as pH and temperature must be…

An undergraduate biochemistry laboratory experiment that will teach the technique of fluorescence resonance energy transfer (FRET) while analyzing protein-induced DNA bending is described. The experiment uses the protein TATA binding protein (TBP), which is a general transcription factor that recognizes and binds specific DNA sequences known as…

For curriculum content-related reasons, inquiry activities can be difficult in classrooms unless the activities are approached in a manner that makes variations among student group findings understandable in the context of the study. Studies of individual animals and plant reactions to stimuli, such as insect exploratory behavior, allow the…

The most recent data on stars orbiting Sagittarius A*, the black hole at the center of the Milky Way galaxy, have been used in an experiment undertaken by second-year university students to determine the distance R[theta] to the center of the galaxy. Students applied each of Kepler's 17th-century laws, in turn, to 21st-century data. The…

Magnetic braking is a long-established application of Lenz's law. A rigorous analysis of the laws governing this problem involves solving Maxwell's equations in a time-dependent situation. Approximate models have been developed to describe different experimental results related to this phenomenon. In this paper we present a new method for the…

We present an experiment, well adapted for students of introductory optics courses, for the visualization of the impact of spherical aberration in the point spread function of imaging systems. The demonstrations are based on the analogy between the point-spread function of spherically aberrated systems, and the defocused patterns of 1D slit-like…

This paper revisits the demonstration of Lenz by dropping magnets down a non-magnetic tube. Recent publications are reviewed and ideas for undergraduate laboratory investigations are suggested. Finally, an example of matching theory to observation is presented. (Contains 4 tables, 5 figures and 3 footnotes.)

Using an easy-to-make cylindrical resonator, students can measure the speed of sound in a gas, u, with sufficiently high precision (by locating standing-wave Lissajous patterns on an oscilloscope) to observe real gas properties at one atmosphere and 300 K. For CO[subscript 2] and SF[subscript 6], u is found to be 268.83 and 135.25 m s[superscript…

Normal mode solutions for the perfectly flexible hanging cord problem have been known for over 200 years. More recently, theoretical results for a hanging cord with a point mass attached were presented. Here the theoretical results are tested experimentally using high-precision techniques which are accessible for use in an introductory laboratory.…

State and district science standards typically call for students to take part in hands-on labs and experiments in the elementary grades. The 1996 National Science Education Standards, which were written by the National Research Council and serve as a reference for many states, emphasize similar activities. Yet the use of even simple labs and…

Inquiry is a goal of science education reform. Middle school science teachers and their students can develop understanding of inquiry by using an experimental design format. Facilitating this format with the four-question strategy helps students to design their investigations. An example of varying concentrations of vinegar and water illustrates…

This paper introduces a novel model of laboratory education, namely the TriLab. The model is based on recent advances in ICT and implements a three access modes to the laboratory experience (virtual, hands-on and remote) in one software package. A review of the three modes is provided with highlights of advantages and disadvantages of each mode.…

This study was a mixed quantitative-qualitative research to evaluate the efficacy of a designed student-centred instructional (DSCI) program for teaching about acids and bases. The teaching innovation was designed based on constructivist, hands-on inquiry and context-based approaches and implemented in seven 45-min lessons with a class of 36 grade…

Incorporating business skills such as problem-solving, public presentations, collaboration, and self-direction into STEM (science, technology, engineering and mathematics) subjects is an excellent way to build students' enthusiasm for these disciplines. When educators add workplace internships to the learning experience, they are well on their way…