A colorimetric method for total capsaicinoids in chili pepper ("Capsicum") fruit is described. The placental material of the pepper, containing 90% of the capsaicinoids, was physically separated from the colored materials in the pericarp and extracted twice with methanol, capturing 85% of the remaining capsaicinoids. The extract, evaporated and…

Photography is one of the few fine art forms that were initially developed by scientists such as Herschel and Talbot; however, in the modern chemistry curriculum, photography has become divorced from its scientific beginnings and resides in the studio arts department of most universities. An upper-level undergraduate experiment is described in…

A cost-effective, hands-on laboratory exercise is described for demonstrating nanoscale fabrication at non-research-based educational institutions. The laboratory exercise also contains a component involving qualitative and quantitative surface characterization of student-fabricated nanoscale structures at institutions with on-site access to an…

The goal of this dissertation is to enable better predictive models by engaging raw experimental data through the Instrumental Model. The Instrumental Model captures the protocols and procedures of experimental data analysis. The approach is formalized by encoding the Instrumental Model in an XML record. Decoupling the raw experimental data from…

Continuous feed and bleed ultrafiltration, modeled with the gel polarization model for the limiting flux, is shown to provide a rich source of non-linear algebraic equations that can be readily solved using numerical and graphical techniques familiar to undergraduate students. We present a variety of numerical problems in the design, analysis, and…

Being able to facilitate effective hands-on laboratory experiences in introductory physics courses is a challenging task, even when contemporary laboratory facilities, equipment, and new technologies for data collection and analysis are available. At institutions without adequate resources, especially those in developing countries, we have found…

This paper was inspired by the numerous requests from "TPT" readers to expand the number of examples of "recurrent study" lab exercises described in my previous paper "Physics Labs with Flavor." I recommend that readers examine it first in order to better understand this one as my attempt here is to be brief. In that paper, one can find details…

In a 4-h laboratory exercise, students accomplish a series of enzymatic macerations of apple mash, assess the viscosity of the mash during the maceration, extract the juice by centrifugation, and measure the levels of antioxidant phenols extracted into the juice after different enzyme treatments. The exercise shows the impact of enzyme-catalyzed…

In this paper the method of converting mechanical work into electrical energy with the participation of a preliminarily charged condenser while the electrodes are sliding in it is presented. Using this method, we can obtain a considerable increase of converted electrical power, depending on the initial energy of the charged condenser, distance…

In this pilot study, a genetics-based laboratory exercise using the cyanobacterium Fremyella diplosiphon was developed and trialled with thirteen Natural Sciences undergraduates. Despite most students only having limited prior exposure to molecular genetics laboratory methods, this cohort confirmed that they were able to follow the protocol and…

The acid ionization constant, K[subscript a], of acetic acid and the base ionization constant, K[subscript b], of ammonia are determined easily and rapidly using a datalogger, a pH sensor, and a conductivity sensor. To decrease sample preparation time and to minimize waste, sequential aliquots of a concentrated standard are added to a known volume…

In this experiment students are exposed to concepts in inorganic synthesis and various spectroscopies as applied to a tri-tungsten cluster with applications in biomedical imaging. The tungsten-acetate cluster, Na[W[superscript 3](mu-O)[subscript 2](CH[superscript 3]COO)[superscript 9]], 1, was synthesized and characterized by [superscript 1]H-NMR,…

In this article we make some significant remarks on the experimental study of the absorption of gamma radiation passing through matter. These remarks have to do with the seemingly unexpected trend of the measured intensity of radiation versus the thickness of the absorber, which puzzles students and its explanation eludes many laboratory…

What follows is a description of several activities involving the Stefan-Boltzmann radiation law that can provide laboratory experience beyond what is normally found in traditional introductory thermodynamics experiments on thermal expansion, specific heat, and heats of transformation. The activities also provide more extensive coverage of and…

This laboratory experiment provides a safe and effective way to instruct undergraduate organic chemistry students about natural-product extraction, purification, and NMR spectroscopic characterization. On the first day, students extract dried habanero peppers with toluene, perform a pipet silica gel column to separate carotenoids from…