A static color discontinuity can capture spatial attention when the target is an abrupt-onset singleton.

C. L. Folk, R. W. Remington, and J. C. Johnston's (1992) contingent involuntary orienting hypothesis states that a salient visual feature will involuntarily capture attention only when the observer's attentional set includes similar features. In four experiments, when the target's relevant feature was its being an abruptly onset singleton, attentional capture occurred for a static discontinuity cue that was the boundary between a group of red Xs contiguously joined to a group of green Os within a single row. Such an attentional capture effect is novel and contrary to Folk et al.'s (1992) hypothesis, because the attentional set for the target should have included abrupt onset but not color discontinuity, which was the feature that captured attention. These capture effects were involuntary because they occurred even when the target never appeared in the same location as the cue, and color could not have been used as a cue to signal the appearance of the target array (cf. B. S. Gibson & E. M. Kelsey, 1998). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

An analytic study of (GaAl)As gain guided lasers at threshold

An analysis of gain-guided diode lasers at threshold is presented. After describing the formulation, the effects of charge induced real refractive index antiguiding and gain-charge density relations are studied in detail. Their influence on the threshold current, modal distributions, and the lateral fax-field radiation patterns is discussed. Next a "model" laser is defined and each parameter including dimensions, compositions, stripewidth, diffusion constants, current spreading resistance, and facet reflectivities is individually varied to determine the resulting modifications in laser properties.     

Preservation of Historical Materials.

Notes that records of American psychology are fast disappearing, and the future worker in history who attempts to chronicle and assess the course of the science and its role in civilization will have little with which to work except for surviving published writings. Personal papers, the chief sources of a rich history, are scarce and neglected. The author makes a call for all American psychologists to contribute to the heritage of the discipline. It is a plea to preserve--and ultimately to deposit in a responsible archive--certain types of materials. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of gas environment on mineral reactions in Colorado oil shale

The effects of various sweep gases (N₂, CO₂, and H₂O) on the decomposition and reaction of calcite and dolomite (ankerite) in Colorado oil shale is reported. The disappearance of reactants and formation of products in the temperature range of 500 to 900 °C is monitored by using powder X-ray diffraction. The results show that, over this temperature range, the effect of gas environment on the rate of silicate formation follows the order $\text{H}{}_2\text{O}\text{s}\text{?}\text{>}\text{CO}{}_2\text{s}\text{?}\text{>}\text{N}{}_2$. The ‘final’ silicate-product phases are observed to be a mixture of melilite, diopside, and merwinite. Global reaction kinetics are developed that describe the rate of CO₂ evolution during decomposition of dolomite and calcite in the presence of various partial pressures of steam. Such data are useful in numerical models of oil shale retorting. Finally, the implications of these results on processing and on environmental aspects of oil shale retorting are discussed.     

PRACTICAL PRODUCTION OF ONE-FIRE LUSTER GLAZED POTTERY*

Various metals in small quantities, singly and in various combinations, were ground in lead and leadless glazes. It was found that various colored lusters, transparent and opaque, could be reproduced under a fair degree of control in an ordinary downdraft gas-fired sagger kiln, which was fired from cones 010 to 1. After cooling to a dull red heat, the glazes were given a short reduction firing. Standard decorative processes were used with the luster glazes. Additional colors were produced by adding stains and metal oxides. Acid-resistant luster glazes were developed.     

EFFECT OF PARTICLE SIZE AND INDEX OF REFRACTION ON REFLECTANCE*

The effect of particle size on the reflectance of thin semitransparent layers, such as enamels, was studied by using mixtures containing opacifying particles of definite sizes in an oil of known index of refraction. The mixtures were applied on a black glass plate, and the reflectance was measured. The coefficient of scatter per unit surface of the particles was calculated and was found to decrease slowly as the particle size decreased. On the other hand, for the range of sizes studied, the reflectance of the semitransparent layer increased rapidly as the particle size decreased.     

Properties of CP: Coefficient of Thermal Expansion,Decomposition Kinetics,Reaction to Spark,Friction and Impact

The properties of pentaamine (5‐cyano‐2H‐tetrazolato‐N2) cobalt (III) perchlorate (CP), which was first synthesized in 1968, continues to be of interest for predicting behavior in handling, shipping, aging, and thermal cook‐off situations. We report coefficient of thermal expansion (CTE) values over four specific temperature ranges, decomposition kinetics using linear and isothermal heating, and the reaction to three different types of stimuli: impact, spark, and friction. The CTE was measured using a Thermal Mechanical Analyzer (TMA) for samples that were uniaxially compressed at 68.95 MPa and analyzed over a dynamic temperature range of −20 °C to 70 °C. Differential scanning calorimetry, DSC, was used to monitor CP decomposition at linear heating rates of 1–7 °C min⁻¹ in perforated pans and of 0.1–1.0 °C min⁻¹ in sealed pans. The kinetic triplet was calculated using the LLNL code Kinetics05, and predictions for 210 °C and 240 °C are compared to isothermal thermogravimetric analysis (TGA) experiments. Values are also reported for spark, friction, and impact sensitivity.     

Life-cycle greenhouse gas emissions of shale gas, natural gas, coal, and petroleum

The technologies and practices that have enabled the recent boom in shale gas production have also brought attention to the environmental impacts of its use. It has been debated whether the fugitive methane emissions during natural gas production and transmission outweigh the lower carbon dioxide emissions during combustion when compared to coal and petroleum. Using the current state of knowledge of methane emissions from shale gas, conventional natural gas, coal, and petroleum, we estimated up-to-date life-cycle greenhouse gas emissions. In addition, we developed distribution functions for key parameters in each pathway to examine uncertainty and identify data gaps such as methane emissions from shale gas well completions and conventional natural gas liquid unloadings that need to be further addressed. Our base case results show that shale gas life-cycle emissions are 6% lower than conventional natural gas, 23% lower than gasoline, and 33% lower than coal. However, the range in values for shale and conventional gas overlap, so there is a statistical uncertainty whether shale gas emissions are indeed lower than conventional gas. Moreover, this life-cycle analysis, among other work in this area, provides insight on critical stages that the natural gas industry and government agencies can work together on to reduce the greenhouse gas footprint of natural gas.     

Relative Dissolution Rates of Several Hydrated Limes

The relative dissolution rates of several commercial hydrated limes were evaluated. Significant differences in dissolution rates were observed ranging from a time of <10 s for 90% dissolution to 1 min for a 5% slurry. A 2% slurry dissolved faster than a 5% slurry. The speed of lime dissolution may be important for some treatment processes.     

Improving vehicle performance using adaptive control techniques

This paper reviews a collaborative research programme aimed at improving vehicle performance using adaptive control techniques. Initially the design of active suspension systems is considered, and the benefits of using a non-linear controller model with an adaptive control scheme are discussed. Adaptive schemes for active roll control are then considered, and the merits of incorporating a Smith predictor to accommodate for system delays are high-lighted. Preliminary research in adaptive cruise control and collision avoidance is discussed and plans for further developments are outlined. This work was presented, in part, at the Third International Symposium on Artificial Life and Robotics, Oita, Japan, 19–21 January 1998