Home and mother: Relations with infant temperament.

Mothers of about 100 toddlers at 12, 18, and 24 months completed the Toddler Temperament Scale. Three other data sets were also available: (a) factors representing lab observations; (b) measures of the mothers who completed the Thurstone Temperament Schedule and ratings made by a social worker of the mother's home; and (c) home measures from Home Observation for Measurement of the Environment and the Family Environment Scale. Direct correlations between the first principal component factor from the Toddler Temperament Scale and the corresponding component from the lab factor were .50, .36, .52, at 12, 18, and 24 months, respectively. Maternal characteristics—emotional stability and social dominance—from the Thurstone Temperament Schedule were related to maternal ratings of the toddler on the Toddler Temperament Scale at all ages (rs?=?.25 to .46). There were only a few low-order correlations from environmental characteristics. A regression analysis, with lab factors entered first, indicated that, after the lab component was extracted, maternal temperament made a modest but significant contribution to maternal reports of toddler temperament. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Atomic-level molecular modeling of the nonionic surfactant Triton X-100: the OPE9 component in vacuum and water

The commercially available nonionic surfactant Triton X-100 is a mixture of polyoxyethylene tert-octylphenyl ethers (OPE_n) with an average of n = 9.5 oxyethylene (OE) units in the molecules, and the population maximum at n = 9. Thus, the OPE_{n = 9} component was chosen to be studied by atomic level molecular modeling, using second-generation force fields. The 1,000 conformers generated via random sampling of torsional angles around single bonds yielded 11 clusters based on geometrical similarity. Representatives of geometrically distinctly different clusters with significant populations were chosen from a narrow energy range around the most probable energy to be analyzed for interaction with water. The effect of water on the conformation of the OE chain was found to be modest, similar to the situation that had been reported earlier for the anionic surfactant Aerosol-OT (AOT). The number of bound water molecules is strongly dependent on the conformation of the OE chain and is affected by electrostatic as well as steric effects. Unlike the case of AOT, for which the length of the hydrophobic tail was found to govern the size of reverse micelles in CCl₄, the size of reverse micelles of OPE_{n = 9} cannot be predicted from the dimensions of the hydrophilic tail.     

An application of the Poisson race model to confidence calibration.

In tasks as diverse as stock market predictions and jury deliberations, a person's feelings of confidence in the appropriateness of different choices often impact that person's final choice. The current study examines the mathematical modeling of confidence calibration in a simple dual-choice task. Experiments are motivated by an accumulator model, which proposes that information supporting each alternative accrues on separate counters. The observer responds in favor of whichever alternative's counter first hits a designated threshold. Confidence can then be scaled from the difference between the counters at the time that the observer makes a response. The authors examine the overconfidence result in general and present new findings dealing with the effect of response bias on confidence calibration. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Adsorption characteristics of polyacrylamide and sulfonate-containing polyacrylamide copolymers on sodium kaolinite

Polyacrylamide and its copolymer containing 6.8 mole % 2-acrylamido-2-methylpropane sulfonic acid were prepared by an irradiation-initiated precipitation polymerization technique. The polymer was characterized by intrinsic viscosity under conditions similar to those used during adsorption measurements. Hydrolytic degradation of the polyacrylamide was found to be negligible under conditions used. The adsorption substrate, sodium kaolinite, was prepared by extensive ion exchange treatment. Equilibrium adsorption of the polymers on the sodium kaolinite was made as a function of polymer concentration, solution pH, ionic strength, and temperature.     

Reactivity imaging of a passive ferritic FeAlCr steel

A technique named reactivity imaging is introduced. It combines optical imaging of a polycrystalline material with orientation imaging by electron back scattering diffraction (EBSD) for a determination of the crystallographic orientation map and scanning electrochemical microscopy (SECM) for a visualization of the local reactivity. Dissolving metal ions from the substrate are directly detected by the scanning Pt tip of the SECM to measure the amount of locally dissolving material. A ferritic light weight steel (alloy Fe7.5Al7Cr) with a strong anisotropic dissolution behaviour was investigated as an example. This steel shows good passivation behaviour both, in air and through anodisation. In the passive state investigated here, the difference in dissolution rate between various crystallographic orientations is only marginal. Grain boundaries on the other hand showed a higher activity as compared to the grains themselves, which is attributed to the electronic tunnelling in the grain boundaries. The results demonstrate that the rate determining step responsible for the anisotropic dissolution does not result from a deficiency in passivation but from the active dissolution kinetics.     

Results and conclusions from the first pressurized-thermal-shock experiment

The first pressurized-thermal-shock test of a 148 mm thick steel pressure vessel with a 1 m long flaw was performed to investigate fracture behavior of a vessel under conditions relevant to a flawed nuclear reactor pressure vessel during an overcooling accident. The objectives were to observe crack arrest and stability on the ductile upper shelf and the effects of warm prestressing on crack initiation. Three coordinated pressure and thermal transients were imposed on the vessel, which was preheated to 290°C. Two episodes of crack propagation and arrest occurred. The thermal transients were induced by coolant at −29 to 15°C. Pressure transients were as high as 94.4 MPa. The experimental objectives were attained. The inhibiting effects of warm prestressing were definitely demonstrated. Crack propagation was nearly pure cleavage, and arrest at 30 K above the onset of the Charpy upper-shelf was experienced in a positive K₁ gradient and with K₁ = 300 MPa√m. Fracture-mechanics analysis of brittle fracture based on small-specimen toughness measurements was reasonably accurate. Flaw evaluation by procedures of the ASME Boiler and Pressure Vessel Code conservatively predicted vessel failure, which did not occur. No ductile tearing occurred after each crack arrest, although some stable tearing had been predicted on the basis of tearing resistance data.     

An inter-laboratory trial of the unified BARGE bioaccessibility method for arsenic, cadmium and lead in soil

The Bioaccessibility Research Group of Europe (BARGE) has carried out an inter-laboratory trial of a proposed harmonised in vitro physiologically based ingestion bioaccessibility procedure for soils, called the Unified BARGE Method (UBM). The UBM includes an initial saliva phase and simulated stomach and intestine compartments. The trial involved the participation of seven laboratories (five European and two North American) providing bioaccessibility data for As (11 samples), Cd (9 samples) and Pb (13 samples) using soils with in vivo relative bioavailability data measured using a swine model. The results of the study were compared with benchmark criteria for assessing the suitability of the UBM to provide data for human health risk assessments. Mine waste and slag soils containing high concentrations of As caused problems of poor repeatability and reproducibility which were alleviated when the samples were run at lower soil to solution ratios. The study showed that the UBM met the benchmark criteria for both the stomach and stomach & intestine phase for As. For Cd, three out of four criteria were met for the stomach phase but only one for the stomach & intestine phase. For Pb two, out of four criteria were met for the stomach phase and none for the stomach & intestine phase. However, the study recommends tighter control of pH in the stomach phase extraction to improve between-laboratory variability, more reproducible in vivo validation data and that a follow up inter-laboratory trial should be carried out.     

Viscosity ratio: A key factor for control of oil drop size distribution in effervescent atomization of oil-in-water emulsions

The present study focused on the effervescent atomization of oil-in-water emulsions and its influence on the internal emulsion structure. The impact of atomization conditions and nozzle geometry on an oil-in-water emulsion with varied viscosity ratio of disperse phase to emulsion was determined. The viscosity ratio is known as a key factor for the drop breakup in emulsification processes. The results depict that oil drops are broken up according to emulsification mechanisms during atomization. A maximum breakup was found for a viscosity ratio between 0.5 and 1. The expected stress dependency of the drop size change was observed for high viscosity ratios only. Relevance of elongational stress on the drop breakup was proven with significant drop size change at high viscosity ratios. The viscosity ratio thus allows for an efficient control of oil drop size change in effervescent atomization as the spray characteristics are invariant to viscosity changes within certain limits.