Examining the cross-race effect in lineup identification using Caucasian and First Nations samples.

This study examined whether findings from research on the cross-race effect (CRE) in eyewitness memory with Caucasian-Black samples can be generalised to Caucasian-First Nations pairings in a lineup identification task. This study used a novel approach to investigate the CRE, using six targets, as well as simultaneous lineups that included both target-present and target-absent arrays. This study also addressed the efficacy of the contact hypothesis as it applies to these populations. A significant CRE was discovered. Furthermore, both Caucasian and First Nations participants were more likely to choose from the lineup when attempting to recognise First Nations faces than when attempting to recognise Caucasian faces. Contact with the other race had no effect on recognition accuracy of that race. Potential implications and directions for future research are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Experimental testing of the polymer–filler gel formation theory. II.

In Part I of the present article predictions of the polymer–filler gel formation theory were tested experimentally using fine-particle silica in natural rubber (NR) and in styrene–butadiene rubber (SBR). Part II brings a more detailed experiment–theory comparison using carbon blacks differing in specific surface area and structure, graphitized blacks, fume silica, and surface-modified (hydrophobized) fume silica. In the region of low and medium filler concentration c, the c-dependence of the fraction G of polymer in polymer–filler gel, of the fraction B of total filler-bound polymer, of the fraction w_disp of solvent-dispersed filler particles were found to be correctly predicted by the theory. The effect of filler characteristics and of the method of its incorporation into the polymer on the values of the adjustable parameters of the theory (filler surface adsorptivity, D, and filler particles connectivity, f) was determined and is discussed. In the region of very high c increasing positive deviations of D from the low-c behavior were observed and an explanation for this effect is proposed. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 95–107, 1998     

Stretching and breaking of a molecular junction

Density functional theory (DFT) calculations based on band structure are used to investigate the electromechanical properties of a molecular junction consisting of a dithiolbenzene molecule sandwiched between two gold slabs. This represents a prototypical system for the field of molecular electronics; such a system has previously been studied in break-junction measurements and electron-transport calculations. The stretching and breaking behavior of the junction is analyzed for different geometric conformations, and it is found that the breakage occurs through dissociation of one of the sulfur-gold bonds with a maximum force of 1.25 nN. The molecular electronic states shift during stretching, and, at the point of highest stress in the junction, the highest occupied molecular orbital (HOMO) of the molecule is located exactly at the Fermi level.     

3D optical coherence tomography as new tool for microscopic investigations of nucleate boiling on heated surfaces

Boiling phenomena are an important aspect in security and efficiency for technical applications with high heat flux like nuclear reactors. This study presents optical coherence tomography (OCT) as a novel modality for three-dimensional and two-dimensional time resolved imaging of nucleate boiling on heated surfaces on a microscopic scale with high spatial (<10 μm) and temporal (>25 frames per second) resolution. Within this study, a borosilicate glass plate coated with an optically transparent and electrically conductive indium tin oxide (ITO) layer with a thickness of approximately 100 nm was used as heating surface. The combination of these two properties allows optical inspection of the nucleate boiling from the backside by OCT focused on the formation, growth and detachment of single bubbles. We demonstrated for the first time that OCT is an excellent tool to acquire two-dimensional and three-dimensional images of the base of vapor bubbles from the backside of the heated surface. The acquired images allow for instance the temporally resolved measurement of the bubble diameter, diameter of the bubble base and the contact angle. Exploiting the phase information of the acquired OCT signal stacks allows imaging the movement of the bubble surrounding fluid. We think that OCT will provide many new insights into the boiling phenomena at the bubble base. The recent enhancement of the acquisition rates of OCT systems will facilitate four-dimensional imaging of single bubble evaporation procedures in the nearer future.     

X-ray based tools for the investigation of buried interfaces in organic electronic devices

X-ray reflectivity combined with grazing incidence diffraction is a valuable tool for investigating organic multilayer structures that can be used in devices. We focus on a bilayer stack consisting of two materials (poly-(3-hexylthiophene)) (P3HT) and poly-(4-styrenesulfonic acid) (PSSA) spin cast from orthogonal solvents (water in the case of PSSA and chloroform or toluene for P3HT). X-ray reflectivity is used to determine the thickness of all layers as well as the roughness of the organic–organic hetero-interface and the P3HT surface. The surface roughness is found to be consistent with the results of atomic force microscopy measurements. For the roughness of P3HT/PSSA interface, we observe a strong dependence on the solvent used for P3HT deposition. The solvent also strongly impacts the texturing of the P3HT crystallites as revealed by grazing incidence diffraction. When applying the various PSSA/P3HT multilayers in organic thin-film transistors, we find an excellent correlation between the determined interface morphology, structure and the device performance.     

Vaporization and Corrosion of Refractories in the Presence of Pressurized Pulverized Coal Combustion Slag

The corrosion and vaporization behavior of eight commercial refractories containing Cr₂O₃ were investigated under simulated pressurized pulverized coal combustion (PPCC) conditions at 1723 K in the presence of liquid slag. The corrosion resistance of the refractory materials decreased with increased content of free Cr₂O₃, because bursting (reaction of Fe₃O₄ with Cr₂O₃) occurred. Refractories containing MgCr₂O₄ with dissolved Al₂O₃ showed the highest corrosion resistance. Thermodynamic calculations showed that CrO₃ and CrO₂(OH)₂ were the most volatile species in air and in PPCC flue gas, whereas additions of A₂O (A = Na and K, minor slag component) increased the chromium vaporization significantly because of A₂CrO₄ formation. Knudsen effusion mass spectrometry measurements showed that the chromium vaporization of refractories was directly correlated to the Cr₂O₃ content of the material. In contrast, refractories containing MgCr₂O₄ showed a significant decrease in chromium vaporization.     

L-fucose residues on cellulose-based dialysis membranes: quantification of membrane-associated L-fucose and analysis of specific lectin binding

Contact of mononuclear human leukocytes with cellulose dialysis membranes may result in complement-independent cell activation, i.e. enhanced synthesis of cytokines, prostaglandins and an increase in beta 2-micro-globulin synthesis. Cellular contact activation is specifically inhibited by the monosaccharide L-fucose suggesting that dialysis membrane associated L-fucose residues are involved in leukocyte activation. In this study we have detected and quantitated L-fucose on commercially-available cellulose dialysis membranes using two approaches. A sensitive enzymatic fluorescence assay detected L-fucose after acid hydrolysis of flat sheet membranes. Values ranged from 79.3 +/- 3.6 to 90.2 +/- 5.0 pmol cm-2 for Hemophan or Cuprophan respectively. Enzymatic cleavage of terminal alpha-L-fucopyranoses with alpha-L-fucosidase yielded 7.7 +/- 3.3 pmol L-fucose per cm2 for Cuprophan. Enzymatic hydrolysis of the synthetic polymer membranes AN-69 and PC-PE did not yield detectable amounts of L-fucose. In a second approach, binding of the fucose specific lectins of Lotus tetragonolobus and Ulex europaeus (UEAI) demonstrated the presence of biologically accessible L-fucose on the surface of cellulose membranes. Specific binding was observed with Cuprophan, and up to 2.6 +/- 0.3 pmol L-fucose per cm2 was calculated to be present from Langmuir-type adsorption isotherms. The data presented are in line with the hypothesis that surface-associated L-fucose residues on cellulose dialysis membranes participate in leukocyte contact activation.