High‐Performance SOFC Cathodes Prepared by Infiltration

Improved cathodes are required for low‐temperature operation of solid‐oxide fuel cells (SOFCs). Recent work has shown that electrode fabrication and modification by infiltration of active components into a porous scaffold can result in outstanding electrochemical performance. In this paper we review the literature on this new approach for cathode preparation and discuss the insights that this work has provided for understanding the relationships between the materials properties, electrochemical performance, and electrode stability.     

Low Temperature Chemical Vapor Deposition of Aluminosilicate Thin Films on Carbon Fibers

We report the deposition of aluminum oxide and aluminosilicate thin films onto carbon fiber substrates, at temperatures of 200° and 250°C, respectively. For aluminosilicate films, the Al/Si ratio of the resultant film varied concomitantly with the composition of the liquid precursor mixture. The growth rate for the oxide films was 15–17 Å/min, comparable with other methods carried out at higher temperatures. Cross-section SEM images indicate that the deposited films are conformal, following the complex topography of the carbon fiber substrate. Preliminary gas-phase IR analysis suggests that the coatings decompose the nerve agent simulant dimethyl methylphosphonate at temperatures as low as 35°C, suggesting the utility of the reported methodology for the design/fabrication of actively protective fabrics and clothing.     

Interpersonal evaluations following threats to self: Role of self-esteem.

In 2 studies, the authors used dyadic interactions to assess the influence of ego threat on likability as a function of self-esteem. In both studies, 2 naive participants engaged in a structured conversation; in half of the dyads, 1 participant received an ego threat prior to the interaction. In the 1st study, threatened high self-esteem participants were rated as less likable than were threatened low self-esteem participants. The 2nd study confirmed that ego threats are associated with decreased liking for those with high self-esteem and with increased liking for those with low self-esteem. A mediational analysis demonstrated that decreased liking among high self-esteem participants was due to being perceived as antagonistic. Study 2 also indicated that the findings could not be explained by trait levels of narcissism. These patterns are interpreted in terms of differential sensitivity to potential interpersonal rejection. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Peacocks, Porsches, and Thorstein Veblen: Conspicuous consumption as a sexual signaling system.

Conspicuous consumption is a form of economic behavior in which self-presentational concerns override desires to obtain goods at bargain prices. Showy spending may be a social signal directed at potential mates. We investigated such signals by examining (a) which individuals send them, (b) which contexts trigger them, and (c) how observers interpret them. Three experiments demonstrated that conspicuous consumption is driven by men who are following a lower investment (vs. higher investment) mating strategy and is triggered specifically by short-term (vs. long-term) mating motives. A fourth experiment showed that observers interpret such signals accurately, with women perceiving men who conspicuously consume as being interested in short-term mating. Furthermore, conspicuous purchasing enhanced men's desirability as a short-term (but not as a long-term) mate. Overall, these findings suggest that flaunting status-linked goods to potential mates is not simply about displaying economic resources. Instead, conspicuous consumption appears to be part of a more precise signaling system focused on short-term mating. These findings contribute to an emerging literature on human life-history strategies. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Self-Regulation and Self-Presentation: Regulatory Resource Depletion Impairs Impression Management and Effortful Self-Presentation Depletes Regulatory Resources.

Self-presentation may require self-regulation, especially when familiar or dispositional tendencies must be overridden in service of the desired impression. Studies 1-4 showed that self-presentation under challenging conditions or according to counter-normative patterns (presenting oneself modestly to strangers, boastfully to friends, contrary to gender norms, to a skeptical audience, or while being a racial token) led to impaired self-regulation later, suggesting that those self-presentations depleted self-regulatory resources. When self-presentation conformed to familiar, normative, or dispositional patterns, self-regulation was less implicated. Studies 5-8 showed that when resources for self-regulation had been depleted by prior acts of self-control, self-presentation drifted toward less-effective patterns (talking too much, overly or insufficiently intimate disclosures, or egotistical arrogance). Thus, inner processes may serve interpersonal functions, although optimal interpersonal activity exacts a short-term cost. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Comparison of the reactivity of high-surface area, monolayer vanadia/ceria catalysts with vanadia/CeO2(1 1 1) model systems

In this study, temperature programmed desorption (TPD) was used to compare the reactivity of a high-surface area, monolayer vanadia/ceria catalyst with that of a 0.5 ML ceria film supported on the (1 1 1) surface of CeO₂ single crystal. TPD and X-ray photoelectron spectroscopy (XPS) experiments with the vanadia/CeO₂(1 1 1) model system were carried out in an ultra-high-vacuum surface analysis system, while TPD studies for the high-surface area vanadia/ceria catalyst were conducted in a high-vacuum microbalance equipped with a mass spectrometer. The TPD studies showed similar reactivity for both samples. They were both active for the oxidation of methanol to formaldehyde and the temperature at which adsorbed methoxide intermediates underwent dehydrogenation to produce formaldehyde during TPD was found to be a function of the oxidation state of the cations in the supported vanadia layer for both samples. The similarity in the results obtained in this study from the high and low surface area samples indicates that monolayer vanadia films supported on metal oxide single crystals are excellent models of high-surface area, polycrystalline, supported vanadia catalysts.     

Effect of SO2 on the oxygen storage capacity of ceria-based catalysts

We have examined the effect of SO₂ poisoning on a series of catalysts having Pd supported on ceria, alumina, and ceria–zirconia. For pre-exposure of 20 ppm SO₂ at 673 K, we observed no changes in the light-off curves for CO oxidation on Pd/alumina. This pre-exposure of SO₂ to Pd/ceria resulted in a significant upward shift in the light-off curve, so that the poisoned Pd/ceria catalyst exhibited similar rates to that of Pd/alumina. Similar upward shifts were observed for the water–gas-shift reaction upon exposure of Pd/ceria or Pd/ceria–zirconia samples to SO₂. However, pulse-reactor data with alternating CO and O₂ pulses showed that SO₂ poisoning actually increased the amount of oxygen that could be transferred to and from the catalyst over the entire temperature range that was examined. The implication of these results for understanding the effect of SO₂ poisoning and the measurement of OSC are discussed.     

Making choices impairs subsequent self-control: A limited-resource account of decision making, self-regulation, and active initiative.

The current research tested the hypothesis that making many choices impairs subsequent self-control. Drawing from a limited-resource model of self-regulation and executive function, the authors hypothesized that decision making depletes the same resource used for self-control and active responding. In 4 laboratory studies, some participants made choices among consumer goods or college course options, whereas others thought about the same options without making choices. Making choices led to reduced self-control (i.e., less physical stamina, reduced persistence in the face of failure, more procrastination, and less quality and quantity of arithmetic calculations). A field study then found that reduced self-control was predicted by shoppers' self-reported degree of previous active decision making. Further studies suggested that choosing is more depleting than merely deliberating and forming preferences about options and more depleting than implementing choices made by someone else and that anticipating the choice task as enjoyable can reduce the depleting effect for the first choices but not for many choices. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Visual event-related potentials in schizotypal personality disorder and schizophrenia.

Schizophrenia (SZ) occurs among a spectrum of disorders with similar characteristics, including schizotypal personality disorder (SPD). Visual processing disturbances have been reported in both disorders, but it is not yet clear which processes are disturbed in both SZ and SPD, suggestive of a common endophenotype, and which appear only in SZ. In order to address this question, the authors evaluated visual event-related potentials (ERPs) elicited during a line-orientation discrimination task in control, SPD, and SZ participants. Visual ERPs allow specification of both the time course and physiological correlates of visual perception and cognition. SZ patients had smaller P100 and P300a amplitudes and prolonged P300b latency compared to the control group. SZ patients also had smaller N160, N200, P300a, and P300b amplitudes compared to the SPD group. SPD participants did not differ from control participants on any ERP measure. These data documented pervasive abnormalities in visual perception and attention in SZ but not in SPD, suggesting that these visual ERP disturbances may not represent a common endophenotype. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Synthesis of Highly Porous Yttria-Stabilized Zirconia by Tape-Casting Methods

Porous ceramics of Y₂O₃-stabilized ZrO₂ (YSZ) were prepared by tape-casting methods using both pyrolyzable pore formers and NiO followed by acid leaching. The porosity of YSZ wafers increased in a regular manner with the mass of graphite or polymethyl methacrylate (PMMA) to between 60% and 75% porosity. SEM indicated that the shape of the pores in the final ceramic was related to the shape of the pore formers, so that the pore size and microstructure of YSZ wafers could be controlled by the choice of pore former. Dilatometry measurements showed that measurable shrinkage started at 1300 K, and a total shrinkage of 26% was observed, independent of the amount or type of pore former used. Temperature-programmed oxidation (TPO) measurements on the green tapes demonstrated that the binders and dispersants were combusted between 550 and 750 K, that PMMA decomposed to methyl methacrylate between 500 and 700 K, and that graphite combusted above 900 K. The porosity of YSZ ceramics prepared by acid leaching of nickel from NiO–YSZ, with 50 wt% NiO, was studied as a function of NiO and YSZ particle size. Significant changes in pore dimension were found when NiO particle size was changed.