Errors in intelligence estimation with short forms of the WAIS.

Because the full Wechsler Adult Intelligence Scale (WAIS) generally takes more than an hour of the clinician's time to administer, short forms based on a selection of subscales are often substituted. The present study shows that in many cases such short forms may give seriously inaccurate results. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Loss of entanglement density during crazing

The formation of fibril surface area during craze growth requires a loss of entangled strand density in the fibrils themselves. To demonstrate the decrease in entangled chain density, thin films of polystyrene are bonded to soft copper grids and strained in tension. This procedure produces crazed specimens in which the craze fibrils can be characterized by a well-defined draw ratio, ₀. The films are then exposed to electron irradiation. This produces chemical crosslinks between the molecules, thus forming a crosslinked network. Subsequent heating of the film aboveT _g results in the entanglement network trying to retract to=1. The crosslink network, however, tries to maintain the. of the craze fibrils at ₀. The craze fibrils thus retract to Ferry's state of ease, _S, where the tension of the entanglement network is balanced by the compression of the crosslink network. Measurements of _s in crazes crosslinked and then healed confirm that a 25 to 50% loss of entanglement density in craze fibrils occurs, in agreement with theoretical predictions.     

Simple three-dimensional imaging of HRP-labelled neurons with the aid of an image processor

A method is described for visualizing the three-dimensional structure of horseradish peroxidase-labelled neurons in the central nervous system of Xenopus laevis tadpoles. The reconstruction is simple, and performed on a commercially available image processing system. Minimal operational skill is required for using this method. Also, various improvements were made where user's simplicity (user-friendliness), speed and required computer memory are concerned. In addition, the excellent properties of the IBAS II system, such as image filtering and image editing functions are fully available, offering a fast, clean and complete final image reconstruction.     

A general framework for preventive maintenance optimization in chemical process operations

Chemical process reliability has become more recognized both in terms of its impact on economics, and for providing academically challenging problems. In this work, we give an overview of some of the major challenges in formulating and optimizing preventive maintenance. As a result, we propose a general framework for preventive maintenance optimization that combines Monte Carlo simulation with a genetic algorithm.

This proposed approach has distinct advantages. When applied to opportunistic maintenance problems, the method developed overcomes demonstrated shortcomings with analytic or Markov techniques in terms of solution accuracy, versatility, and tractability. The framework is easily integrable with general process planning and scheduling, and it provides sensitivity analysis. Furthermore, a genetic algorithm combines well with Monte Carlo simulation to optimize a non-deterministic objective function.     

A Comparison of Chemistry and Inclusion Distribution and Morphology Versus Melting Method of NiTi Alloys

NiTi alloys are produced by three melting methods. The first method requires compaction of nickel and titanium raw material into sections that can be joined together for melting in a Vacuum Arc Remelt unit (VAR). This ingot is melted two or more times in a VAR. The second method utilizes a Vacuum Induction Melting (VIM) unit to alloy the nickel and titanium, with the use of a graphite crucible. The resulting ingot is prepared and remelted in a VAR. The third method begins with primary melting in a vacuum Induction Skull Melter (ISM). The ISM produces ingots that are assembled into an electrode for VAR melting. For each of the melting methods, the final product depends on the quality and handling of the raw materials, the control of the process at each unit, and the preparation of the intermediate ingots for further processing. The melting method influences the final chemistry as well as the type and number of inclusions present in the final product. This study compares the chemistry and microcleanliness of product manufactured by each method to determine the appropriate melting technique that produces NiTi with the lowest residual elements, such as carbon, as well as the lowest size, and number of inclusions.     

Contingent capture for onsets and offsets: Attentional set for perceptual transients.

Four experiments were conducted to examine whether attentional set affects the ability of visual transients (onsets and offsets) to capture attention. In the experiments, visual search for an identity-defined target was conducted. In the first 3 experiments, the target display either onset entirely or was revealed by offsetting camouflaging line segments to reveal letters. Prior to the target display, there was a noninformative cue, either an onset or an offset, at one of the potential target locations. Cues that shared the same transient feature as the target display captured attention. The lack of predictable target transients led to attentional capture by all forms of transients. The final experiments with luminance changes without offsets or onsets showed attentional capture when the luminance changes were large. The results suggest that attentional set can be broadly or narrowly tuned to detect changes in luminance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)