Measurements of the thermal conductivity of nitrogen with a parallel-plate instrument

A parallel-plate apparatus is suited for accurate measurements of the thermal conductivity coefficient of fluids over a wide range of densities. This is illustrated by measurements of the thermal conductivity coefficient of nitrogen at a temperature of 308.15 K and at pressures up to 20.1 MPa with an accuracy of 0.5%. The agreement with a recent correlation based on accurate measurements by other authors is satisfactory.     

"Do I know you?": The role of significant others in general social perception.

This research used an idiographic method to examine the proposition that significant others are mentally represented as well-organized person categories that can influence social perception even more than representations of nonsignificant others, stereotypes, or traits. Together, Studies 1 and 2 showed that significant-other representations are richer, more distinctive, and more cognitively accessible than the other categories. Study 3 replicated the accessibility data and gauged inferential power by indirectly activating each category in a learning trial about a fictional person and then testing recognition memory. The results showed that participants made more category-consistent false-positive errors about targets who activated significant others vs. any other category. This constitutes the first experimental demonstration of transference and has implications both for social categorization and for basic personality processes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Near infrared absorption coefficient of molten glass by emission spectroscopy

Emission spectroscopy is applied in the determination of the near infrared spectral absorption coefficient of molten glass. The glass is held in a small horizontal platinum alloy crucible, within an electrically heated cell, optically coupled to a Fourier transform spectrometer. A formula is derived which relates emissivity to absorption coefficient, thickness, and reflectivities for the glass-air and glass-metal interfaces. The reflectivity parameters are determined, in effect, by varying the thickness. Spectral absorption coefficient results are compared with results of transmission spectroscopy. The emission technique is advantageous in that it eliminates the problem of chemical reactions with window materials used in the transmission method, and sample preparation and interfacing to commercially available spectrometers is simplified.     

Uptake of triiodothyronine into cultured human muscle cells

The uptake of T3 was measured in cultured human muscle cells at 37 degrees C and pH 7.4 in a medium containing albumin and glucose. The initial up]take increased linearly when the total T3 concentration was varied from 10(-9) to 10(-4) M. At prolonged incubation time the uptake decreased to virtually zero in about 30 min. These data indicate a rapid passive transport mechanism of T3 and a fast equilibration of the cellular T3 with the surrounding medium. In agreement with these conclusions the efflux of T3 was rapid and the initial uptake was not altered by pre-incubation in a T3-containing medium.     

Stochastic kinematic modeling and feature extraction for gait analysis

This research presents a new model-based approach toward the three-dimensional (3-D) tracking and extraction of gait and human motion. We suggest the use of a hierarchical, structural model of the human body that introduces the concept of soft kinematic constraints. These constraints take the form of a priori, stochastic distributions learned from previous configurations of the body exhibited during specific activities; they are used to supplement an existing motion model limited by hard kinematic constraints. We use time-varying parameters of the structural model to measure gait velocity, stance width, stride length, stance times, and other gait variables with multiple degrees of accuracy and robustness. To characterize tracking performance, we also introduce a novel geometric model of expected tracking failures. We demonstrate and quantify the performance of the suggested models using multi-view, video sequences of human movement captured in a complex home environment.     

High Resolution Synchrotron X-Radiation Diffraction Imaging of Crystals Grown in Microgravity and Closely Related Terrestrial Crystals

Irregularities in three crystals grown in space and in four terrestrial crystals grown under otherwise comparable conditions have been observed in high resolution diffraction imaging. The images provide important new clues to the nature and origins of irregularities in each crystal. For two of the materials, mercuric iodide and lead tin telluride, more than one phase (an array of non diffracting inclusions) was observed in terrestrial samples; but the formation of these multiple phases appears to have been suppressed in directly comparable crystals grown in microgravity. The terrestrial seed crystal of triglycine sulfate displayed an unexpected layered structure, which propagated during directly comparable space growth. Terrestrial Bridgman regrowth of gallium arsenide revealed a mesoscopic structure substantially different from that of the original Czochralski material. A directly comparable crystal is to be grown shortly in space.     

The theory of maximum kW demand charges for electricity

The kilowatt (kW) demand charge characterizes most electricity price schedules for industrial customers, yet it has not been analysed thoroughly (compared with time-of-use rates). This article shows how such charges complicate interpretations of past estimates of the industrial demand for electricity. Using a utility maximization (cost minimization) model, we derive consistent demand curves, which are shown potentially to be subject to discontinuities.     

Manganese ferrite thin films Part I: Preparation and structure

The preparation of manganese ferrite thin films by the reactive evaporation of oxidic materials is reported. The process is not critical and provides homogeneous mirror-like films with spinel structure. An annealing procedure below 750 °C has a strong influence on the properties of the films. Special attention is paid to the partial oxygen pressure during the annealing process. For this purpose data are collected from the literature concerning the equilibrium conditions of the spinel structure for varying manganese-iron contents. The lattice constant of the spinel structure of the films is determined by electron diffraction.     

Necessity of spatial pooling for the perception of heading in nonrigid environments.

This study examined whether the perception of heading is determined by spatially pooling velocity information. Observers were presented displays simulating observer motion through a volume of 3-D objects. To test the importance of spatial pooling, the authors systematically varied the nonrigidity of the flow field using two types of object motion: adding a unique rotation or translation to each object. Calculations of the signal-to-noise (observer velocity-to-object motion) ratio indicated no decrements in performance when the ratio was .39 for object rotation and .45 for object translation. Performance also increased with the number of objects in the scene. These results suggest that heading is determined by mechanisms that use spatial pooling over large regions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)