This research examined how differences in category structure affect category learning and category representation across points of development. The authors specifically focused on category density--or the proportion of category-relevant variance to the total variance. Results of Experiments 1-3 showed a clear dissociation between dense and sparse…

This thesis outlines how meV-resolution inelastic x-ray scattering and causality-enforcing mathematics can be used to measure the dynamical density-density linear response function for liquid water with Angstrom spatial resolution and 50fs temporal resolution. The results are compared to high-resolution spectroscopic and scattering experiments and…

Ion implantation is widely used in the microelectronics industry for fabrication of source and drain transistor regions. Unfortunately, implantation causes considerable damage to the substrate lattice rendering most of the implanted dopant electrically inactive. Rapid thermal annealing (RTA) heals the damage by rapidly heating the substrate with a…

We present a new, low-cost method of building an all copper heat-pipe oven that increases the practicality of this device in advanced undergraduate instructional labs. The construction parts are available at local hardware and plumbing supply stores, and the assembly techniques employed are simple and require no machining. (Contains 1 footnote, 3…

Three experiments investigated the impact of planning and preparing a manual grasping or pointing movement on feature detection in a visual search task. The authors hypothesized that action planning may prime perceptual dimensions that provide information for the open parameters of that action. Indeed, preparing for grasping facilitated detection…

The South East Physics Network (SEPnet) (www.sepnet.ac.uk/gcse.php) is exploring various ways to enhance physics learning and A-level uptake, including a series of interactive GCSE revision events. The first event, which includes talks and various physics exhibits by leading teachers and educators, is on energy and the exhibition--called "Who…

Two systems were evaluated for drawing Lewis structures of period 2 and 3 non-metallic compounds: the octet rule and minimization of formal charge. The test set of molecules consisted of the oxides, halides, oxohalides, oxoanions, and oxoacids of B, N, O, F, Al, P, S, and Cl. Bond orders were quantified using experimental data, including bond…

Purpose: To evaluate how perceptual importance of spectral tilt is altered when formant information is degraded by sensorineural hearing loss. Method: Eighteen listeners with mild to moderate hearing impairment (HI listeners) and 20-23 listeners with normal hearing (NH listeners) identified synthesized stimuli that varied in second formant…

The power distributions of nearly all major countries have accepted three-phase distribution as a standard. With increasing power requirements of instrumentation today even a small physics laboratory requires a three-phase supply. While physics students are given an introduction to this in passing, no experimental work is done with three-phase…

Purpose: Current electrolarynx (EL) devices produce a mechanical speech quality that has been largely attributed to the lack of natural fundamental frequency (F0) variation. In order to improve the quality of EL speech, in the present study the authors aimed to develop and evaluate an automatic F0 control scheme, in which F0 was modulated based on…

Bacteria are ubiquitous in our world. From our homes, to our work environment, to our own bodies, bacteria are the omnipresent although often unobserved companions to human life. Physicists are typically untroubled professionally by the presence of these bacteria, as their study usually falls safely outside the realm of our typical domain. In the…

From an early age, so much emphasis goes into teaching children the fundamentals of color theory, in particular the primary colors of red, yellow, and blue. Toys, building blocks, furniture, and so many other items used in a preschool environment are manufactured in these three colors. Yet, recent research has uncovered that babies as young as…

Participants earned points by pressing a computer space bar (Experiment 1) or forming rectangles on the screen with the mouse (Experiment 2) under differential-reinforcement-of-low-rate schedules, followed by extinction. Variability in interresponse time (the contingent dimension) increased during extinction, as for Morgan and Lee (1996);…

Phosphorylation of proteins by protein kinases is an important mechanism in the regulation of protein activity. Among hundreds of protein kinases present in human cells, PKA, the first kinase discovered, belongs to the most important and best characterized group of these enzymes. The author presents an experiment that analyzes the "in vitro"…

Lexical priming, whereby a prime word facilitates recognition of a related target word (e.g., "nurse" [right arrrow] "doctor"), is typically attributed to association strength, semantic similarity, or compound familiarity. Here, the authors demonstrate a novel type of lexical priming that occurs among unassociated, dissimilar,…