Chromium evaporation and oxidation characteristics of alumina-forming austenitic stainless steels for balance of plant applications in solid oxide fuel cells

The chromium (Cr) evaporation behavior of several different types of iron (Fe)-based AFA alloys and benchmark Cr₂O₃-forming Fe-based 310 and Ni-based 625 alloys was investigated for 500 h exposures at 800 °C to 900 °C in air with 10% H₂O. The Cr evaporation rates from alumina-forming austenitic (AFA) alloys were ~5 to 35 times lower than that of the Cr₂O₃-forming alloys depending on alloy and temperature. The Cr evaporation behavior was correlated with extensive characterization of the chemistry and microstructure of the oxide scales, which also revealed a degree of quartz tube Si contamination during the test. Long-term oxidation kinetics were also assessed at 800 to 1000 °C for up to 10,000 h in air with 10% H₂O to provide further guidance for SOFC BOP component alloy selection.     

Temporary leukocyte depletion reduces ventricular dysfunction during prolonged postischemic reperfusion

Leukocyte depletion improves early postischemic ventricular performance in neonatal models of global myocardial ischemia. However, the rate of leukocyte reaccumulation after cardiopulmonary bypass and its subsequent impact on myocardial function is not known. This laboratory study examined the effect of leukocyte depletion on myocardial performance during the initial 6-hour period after bypass in an in situ, in vivo porcine model of neonatal cardiac surgery. Fifteen 3- to 5-day-old piglets (eight control and seven leukocyte depleted animals) were instrumented by placement of left ventricular short-axis sonomicrometry crystals and an intraventricular micromanometer catheter. Mechanical leukocyte depletion was achieved with Pall RC100 filters (Pall Biomedical, Inc., Fajardo, Puerto Rico) in the cardiopulmonary bypass circuit. Neonatal hearts were subjected to 90 minutes of hypothermic ischemia after a single dose of cold crystalloid cardioplegia. Two control animals died after the operation and were excluded from data analysis. Leukocyte filtration reduced the granulocyte count during initial myocardial reperfusion to 0.8% of control values. However, circulating granulocyte counts increased in leukocyte depleted animals throughout the postoperative period, reaching 68% of control values by 6 hours. Despite this rapid return of circulating granulocytes, animals subjected to leukocyte depletion had significantly better preservation of left ventricular performance (measured by preload recruitable stroke work, p < or = 0.02), left ventricular systolic function (measured by end-systolic pressure-volume relationship, p < or = 0.05), and ventricular compliance (p < or = 0.04) during the experiment. These changes in ventricular function were associated with a significant increase in left ventricular water content (p < or = 0.02) and tissue myeloperoxidase activity (p < or = 0.005) in control animals compared with leukocyte depleted animals. This study demonstrates that leukocyte depletion during initial reperfusion results in sustained improvement in postischemic left ventricular function despite the rapid return of granulocytes to the circulation.     

Effect of humidity and temperature on the adhesive strength of pressure sensitive adhesives

This paper reports the effect of humidity and temperature on the adhesive strength of a pressure sensitive adhesive (Flexbond 150) used to bond Mylar films. It has been found that, ill general, the adhesive strength decreases significantly with an increase in temperature. The effect of humidity on the bonding strength, however, was found to be process dependent. The sample preparation conditions, e.g., press weight for the bonding and the press time, are important in determining the humidity effect. The water sorption isotherm A 24°C for the adhesive was also determined. The amount of water sorbed by the adhesive at 95 percent relative pressure was found to be less than one weight percent.     

Effects of flux enhancing polymer on the characteristics of sludge in membrane bioreactor process.

A newly developed membrane performance enhancer (MPE) was used to prevent membrane fouling in a membrane bioreactor (MBR) process. It transpired that 1,000 mg/l of MPE reduced polysaccharide levels from 41 mg/I to 21 mg/I on average under the experimental condition. Repeated experiments also confirmed that 50-1,000 mg/l of MPE could reduce membrane fouling significantly and increase the intervals between membrane cleanings. Depending on MPE dosages and experimental conditions, trans-membrane pressure (TMP) increase was suppressed for 20-30 days, while baseline TMP surged within a few days. In addition, MPE allowed MBR operation even at 50,000 mg/l of total solid and reduced permeate COD. However, no evidence of toxicity for sludge was found from respiratory works.     

The Kitty Genovese murder and the social psychology of helping: The parable of the 38 witnesses.

This article argues that an iconic event in the history of helping research--the story of the 38 witnesses who remained inactive during the murder of Kitty Genovese--is not supported by the available evidence. Using archive material, the authors show that there is no evidence for the presence of 38 witnesses, or that witnesses observed the murder, or that witnesses remained inactive. Drawing a distinction between the robust bystander research tradition and the story of the 38 witnesses, the authors explore the consequences of the story for the discipline of psychology. They argue that the story itself plays a key role in psychology textbooks. They also suggest that the story marks a new way of conceptualizing the dangers of immersion in social groups. Finally, they suggest that the story itself has become a modern parable, the telling of which has served to limit the scope of inquiry into emergency helping. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Microfabricated Lamb wave device based on PZT sol-gel thin film formechanical transport of solid particles and liquids

The fabrication using silicon micromachining and characterization of an acoustic Lamb wave actuator is presented. The intended use of the device is for mass transport and sensor applications. The device consists of dual interdigitated transducers patterned on a thin-film composite membrane of silicon nitride, platinum, and a sol-gel-derived piezoelectric ceramic (PZT) thin film. The acoustic properties of the device are presented along with preliminary applications to mechanical transport and liquid delivery systems. Improved acoustic signals and improved mass transport are achieved with PZT over present Lamb wave devices utilizing ZnO or AlN as the piezoelectric transducer     

Mapping a quantitative trait locus involved in melanotic encapsulation of foreign bodies in the malaria vector, Anopheles gambiae

A Plasmodium-refractory strain of Anopheles gambiae melanotically encapsulates many species of Plasmodium, whereas wild-type mosquitoes are usually susceptible. This encapsulation trait can also be observed by studying the response of refractory and susceptible strains to intrathoracically injected CM-Sephadex beads. We report the results of broad-scale quantitative trait locus (QTL) mapping of the encapsulation trait using the bead model system. Interval mapping using the method of maximum likelihood identified one major QTL, Pen1. The 13.7-cM interval containing Pen1 was defined by marker AGH157 at 8E and AGH46 at 7A on 2R. Pen1 was associated with a maximum LOD score of 9.0 and accounted for 44% of the phenotypic variance in the distribution of phenotypes in the backcross. To test if this QTL is important for encapsulation of Plasmodium berghei, F2 progeny were infected with P. berghei and evaluated for degree of parasite encapsulation. For each of the two markers that define the interval containing Pen1, a significant difference of encapsulation was seen in progeny with at least one refractory allele in contrast with homozygous susceptible progeny. These results suggest that Pen1 is important for melanotic encapsulation of Plasmodium as well as beads.