Seeing one thing and doing another: Contrast effects in automatic behavior.

Research on automatic behavior demonstrates the ability of stereotypes to elicit stereotype-consistent behavior. Social judgment research proposes that whereas traits and stereotypes elicit assimilation, priming of exemplars can elicit judgmental contrast by evoking social comparisons. This research extends these findings by showing that priming exemplars can elicit behavioral contrast by evoking a social comparison. In Study 1, priming professor or supermodel stereotypes led, respectively, to more and fewer correct answers on a knowledge test (behavioral assimilation), but priming exemplars of these categories led to the reverse pattern (behavioral contrast). In Study 2, participants walked away faster after being primed with an elderly exemplar. In Study 3, the proposition that contrast effects reflect comparisons of the self with the exemplar was supported. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Synthesis and characterization of poly (N-butyl-3,6-carbazolediyl)

Summary Poly (N-butyl-3,6-carbazolediyl) was synthesized by electrochemcial reduction of the NiBr₂, 2,2bipyridine/3,6 dibromo N-butylcarbazole system in N,N dimethylacetamide. The favorable interactions between solvent and butyl groups lead to the solubilization of the electroactive polymer in organic medium and allowed the determination of macromolecular and structural features by means of classical methods. From ¹³C NMR investigations it was concluded to a conjugation centered on the nitrogen atom of the carbazolic structure.     

New types of metal-insulator-semiconductor switch

Theoretical considerations and experimental results of Metal-Insulator-Semiconductor-Switches (MISS) have been reported in the literature[1–5]. A new model has been recently proposed[6] which explains the current-voltage characteristics by the coupled action of two active devices. In this paper experimental studies are reported on MISS devices with (a) semi-insulating tin oxide and (b) polysilicon layers. The tin-oxide layer has favorable optical properties. In polysilicon samples multiple impedance states have been found. Pulse measurements show, there are three phases associated with the turn-on transient behaviour. The device has higher light sensitivity, higher speed and better I.C. compatibility, than the conventional pnpn diode switch.     

Time-interleaved SAR ADC design with background calibration

In this article, a low power time-interleaved SAR (TI-SAR) ADC is presented. Background calibration is used to improve the linearity of the ADC. Offset, gain, and capacitor mismatches between interleaved channels are calibrated by postprocessing the ADC output. Besides, a novel trimming-based calibration algorithm is used to calibrate the timing mismatches between channels. The proposed calibration algorithm is more power-efficient compared with most of its counterparts. The ADC consists of 18 parallel channels, a reference channel with two dummy channels, and a channel for timing calibration. The timing calibration channel is clocked only when the reference channel samples. The dummy channels are utilized to equalize the input load over time as they sample one after another to fill the gap where the reference channel does not sample. There is no need for any other dummy channels for timing calibration channel since it has low kickback noise over input driver. Each parallel channel operates at 111 ms/s while the reference channel runs at 105 ms/s. The aggregate sampling speed of the converter is 2 GS/s, and 52-dB SNDR is accomplished near Nyquist frequencies.     

Design of light scattering in nanowire materials for photovoltaic applications

We experimentally investigate the optical properties of layers of InP, Si, and GaP nanowires, relevant for applications in solar cells. The nanowires are strongly photonic, resulting in a significant coupling mismatch with incident light due to multiple scattering. We identify a design principle for the effective suppression of reflective losses, based on the ratio of the nondiffusive absorption and diffusive scattering lengths. Using this principle, we demonstrate successful suppression of the hemispherical diffuse reflectance of InP nanowires to below that of the corresponding transparent effective medium. The design of light scattering in nanowire materials is of large importance for optimization of the external efficiency of nanowire-based photovoltaic devices.     

Regioselective Organocatalytic Formation of Carbamates from Substituted Cyclic Carbonates

A highly regioselective catalytic approach has been developed towards carbamates derived from cyclic organic carbonates by reaction of the latter with amine reagents under organocatalytic control. For various combinations of carbonate and amine substrates, an organocatalyst (TBD: 1,5,7‐triazabicyclo[4.4.0]dec‐5‐ene) was used to increase the reaction kinetics while exerting excellent regioselective control. The current method is the first general approach towards the control over the regioselectivity of this reaction using a wide variety of easily accessed substituted organic carbonates.

     

Evaluation of effects of non-thermal plasma treatment on surface properties of CAD/CAM materials

The purpose of this in vitro study was to evaluate the effect of the non-thermal plasma (NTP) treatment on the wettability and surface roughness of different types of CAD/CAM materials as well as the shear bond strength (SBS) of adhesive resin cement to the treated surfaces. Three different materials, namely; resin nano ceramic, feldspathic ceramic and poly(methyl methacrylate) (PMMA)-based samples were treated with NTP for different time points to evaluate the effect of NTP treatment on the surface properties of CAD/CAM materials. Moreover, surfaces of CAD/CAM materials were visualised with scanning electron microscopy (SEM). A 90-second NTP treatment time was determined as the optimum time for the highest measured wettability, and thus, the 90-second NTP treated samples were used for the SBS test and evaluation of the failure types. Our results revealed the NTP treatment lowered the contact angles and increased the roughness of all tested materials. Moreover, The NTP treatment significantly enhanced the SBS of resin nano ceramic and feldspathic ceramic-based materials. NTP could be considered as a novel pre-treatment method to improve surface properties and the bonding performance of ceramic-based CAD/CAM materials.     

Highly active screen-printed IrTi4O7 anodes for proton exchange membrane electrolyzers

Electroceramic support materials can help reducing the noble-metal loading of iridium in the membrane electrodes assembly (MEA) of proton exchange membrane (PEM) electrolyzers. Highly active anodes containing Ir-black catalyst and submicronic Ti₄O₇ are manufactured through screen printing technique. Several vehicle solvents, including ethane-1,2-diol; propane-1,2-diol and cyclohexanol are investigated. Suitable functional anodic layer with iridium loading as low as 0.4 mg cm^?2 is obtained. Surface properties of the deposited layers are investigated by atomic force microscopy (AFM). The most homogeneous coating with the highest electronic conductivity is obtained using cyclohexanol. Tests in PEM electrolyzer operating at 1.7 V and 40 °C demonstrate that the CCM with anode coated with cyclohexanol presents a 1.5-fold higher Ir-mass activity than that of the commercial CCM.