In this work, the oscillations of a homogeneous string fixed at both ends, and loaded with a finite number of masses, are studied. Through a simple device, the cases with one and two concentrated masses are analysed in detail. The normal modes are observed and the corresponding frequencies are recorded. The experimental results and the solutions…

A study was conducted to examine the structural order-disorder transformation promoted by controlled heat treatment using X-ray diffraction technique (XRD) and photoluminescence (PL) techniques as tools to monitor the degree of structural order. The experiment was observed to be versatile and easily achieved with low cost which allowed producing…

The space shuttle Endeavour, slated to begin an 11-day mission August 7, will carry an educational payload that includes two "growth chambers" loaded with basil and lettuce seeds, and a list of activities to be led by teacher-turned-astronaut Barbara R. Morgan. The activities targeted to K-12 students are add-ons to the shuttle crew's primary…

Although the averageness hypothesis of facial attractiveness proposes that the attractiveness of faces is mostly a consequence of their averageness, 1 study has shown that caricaturing highly attractive faces makes them mathematically less average but more attractive. Here the authors systematically test the averageness hypothesis in 5 experiments…

Listeners hearing an ambiguous phoneme flexibly adjust their phonetic categories in accordance with information telling what the phoneme should be (i.e., recalibration). Here the authors compared recalibration induced by lipread versus lexical information. Listeners were exposed to an ambiguous phoneme halfway between /t/ and /p/ dubbed onto a…

Predictive visual context facilitates visual search, a benefit termed contextual cuing (M. M. Chun & Y. Jiang, 1998). In the original task, search arrays were repeated across blocks such that the spatial configuration (context) of all of the distractors in a display predicted an embedded target location. The authors modeled existing results using…

In everyday life, people typically observe fragments of causal networks. From this knowledge, people infer how novel combinations of causes they may never have observed together might behave. I report on 4 experiments that address the question of how people intuitively integrate multiple causes to predict a continuously varying effect. Most…

The construction of a fluorometer and a spectrofluorometer using flashlight or a sunlight excitation source in a shoebox and the eye as a detector is being described. The assembly helps in understanding several fundamental ideas related to the subject very easily.

We have designed a laboratory experiment to illustrate the use of spectroelectrochemical techniques for determination of aqueous iron. The experiment described in this article is applicable to an undergraduate laboratory course in analytical chemistry. Students are asked to fabricate spectroelectrochemical sensors, make electrochemical and optical…

Crystals of naphthalene form on the surface of an acetone solution and dance about in an animated fashion illustrating surface tension, crystallization, and intermolecular forces. Additional experiments reveal the properties of the solution. Flows within the solutions can be visualized by various means. Previous demonstrations of surface motion…

In this laboratory experiment, general chemistry students measure the heating curves for three different systems: (i) 500 g of room-temperature water heated by a small desk lamp, (ii) 500 g of an ice-water mixture warmed by conduction with room-temperature surroundings, and (iii) 500 g of an ice-water mixture heated by a small desk lamp and by…

Degradative enzymes in over-the-counter products from pharmacies and health food stores provide good examples of biological catalysis. These include [beta]-galactosidase in Lactaid[TM], [alpha]-galactosidase in Beano[R], [alpha]-amylase and proteases in digestive aids, and proteases in contact lens cleaners. These enzymes can be studied…

The use of generated intensity distributions as overlays on the HCl rotational-vibrational FTIR spectrum is presented as an effective method to integrate lab work into the physical chemistry lecture. The overlays that best match the actual HCl spectrum are generated using a pre-exponential factor of 2J+2.

The following tested Kintsch's [Kintsch, W. (2000). "Metaphor comprehension: a computational theory." "Psychonomic Bulletin & Review," 7, 257-266 and Kintsch, W. (2001). "Predication." "Cognitive Science," 25, 173-202] Predication Model, which predicts that working memory capacity is an important factor in metaphor processing. In support of his…

The authors examined whether participants can shift their criterion for recognition decisions in response to the probability that an item was previously studied. Participants in 3 experiments were given recognition tests in which the probability that an item was studied was correlated with its location during the test. Results from all 3…