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.     

Plastic flow and fracture of Pd40Ni40P20 metallic glass under an indentor

The geometry of plastic flow under spherical and Vickers indentors in Pd₄₀Ni₄₀P₂₀ metallic glass has been investigated by sectioning and etching. The surface pile-ups and slip lines around the indentations are found to be only a small part of the total deformation. Beneath the surface extensive plastic zones are formed in which material is moved radially away from the indentor, but this movement is produced by slip on surfaces of high shear stress rather than by direct radial flow or compaction. Networks of cracks or incipient cracks also form around an indentation but are not normally visible until the material is etched.     

Microwave cavity perturbation technique: Part I: Principles

This report reviews the analysis used to extract the complex conductivity of a compound from a microwave cavity perturbation measurement. We intend to present a generalized treatment valid for any spheroidally shaped sample of arbitrary conductivity which is placed at either the electric or magnetic field antinode of the cavity. To begin with, we establish the relationship between the measured parameters and the conductivity for a spherical sample. Next, we extend these results to the case of spheroids; and for the first time, we cover all different configurations that one can possibly use to study an arbitrary conducting sample inside a cavity: in particular, all possible orientations of the sample with respect to the applied field are solved.     

Enzymatic biodiesel production: Technical and economical considerations

It is well documented in the literature that enzymatic processing of oils and fats for biodiesel is technically feasible. However, with very few exceptions, enzyme technology is not currently used in commercial‐scale biodiesel production. This is mainly due to non‐optimized process design and a lack of available cost‐effective enzymes. The technology to re‐use enzymes has typically proven insufficient for the processes to be competitive. However, literature data documenting the productivity of enzymatic biodiesel together with the development of new immobilization technology indicates that enzyme catalysts can become cost effective compared to chemical processing. This work reviews the enzymatic processing of oils and fats into biodiesel with focus on process design and economy.     

Microstructural changes during ageing of Cu-2.5 wt% Ti

Microstructural changes in Cu-2.5wt % Ti during ageing at 573 and 773 K have been studied by transmission electron microscopy. Ageing times ranged from 60 sec to 200 h. Ordering of the precipitates was observed after very short ageing treatments at 773 K, and coarsening according tot ^1/3 was also observed from very early times. The particles were observed to become increasingly aligned into rod-like groups along 10 0 as ageing progressed. These results permit a new interpretation of the strengthening mechanisms in this alloy.     

An experimental study of plasticating in a reciprocating-screw injection molding machine

Experimental studies were performed with low density polyethylene, acrylonitrile-butadiene-styrene polymers and on polyvinyl chloride to elucidate the nature of the plasticating process in a reciprocating-screw injection molding machine. Melting data, obtained by use of the “cooling experiment,” and plastic temperature data reveal that the screw recharge process is a transient plasticating extrusion process which gradually approaches the equilibrium extrusion behavior as the screw rotates. If the screw rotation time is a high percentage of the total cycle time, the plasticating behavior is very similar to steady-state extrusion behavior, but if the screw rotation time is a small percentage of the total cycle time, the plasticating behavior is significantly different. Furthermore, better plasticating is obtained by use of a low RPM and high percentage rotation time than by a high RPM and low percentage rotation time.     

Negative cognitive styles, dysfunctional attitudes, and the remitted depression paradigm: A search for the elusive cognitive vulnerability to depression factor among remitted depressives.

Results from studies using a behavioral high-risk design and approximations to it generally have corroborated the cognitive vulnerability hypothesis of depression, whereas results from remitted depression studies typically have not. Suspecting that design features of previously conducted remitted designs likely precluded them from detecting maladaptive cognitive patterns, the authors conducted a study featuring the remitted design that has been successful in studies of a biological vulnerability for depression. Participants' current depressive symptoms, negative cognitive styles (hopelessness theory), dysfunctional attitudes (Beck's theory), and lifetime prevalence of clinically significant depression were assessed. Participants who had remitted from an episode of clinically significant depression had more negative cognitive styles, but not greater levels of dysfunctional attitudes, than did never depressed individuals. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Total System Reliability: Integrated Model for Growth and Test Termination

Reliability demonstration testing is not the most efficient method of assuring product reliability prior to shipment. It is costly, time consuming and has inherent technical and social limitations. The dilemma facing the reliability and quality engineer is whether to continue demonstration testing and risk shipping a product late or ship the product and risk warranty and field service returns. Either option can cause the company to lose significant market share and profit. This paper sets out to solve this dilemma by meeting both the time to market constraints and the product reliability goals. The weaknesses of existing reliability demonstration techniques are explored and a comprehensive methodology is introduced involving controlled development processes, stress testing, root cause determination and process change feedback mechanisms. All prototype products are manufactured on the final volume process line resulting in the early identification and correction of process‐related problems. Testing commences on the first available prototypes with system stress/robust testing being employed to stimulate failures, determine their root cause and correct them. Reliability growth modelling assesses the ongoing improvements occurring in reliability during the development cycle, while a statistical stopping rule is used to determine the optimal product release time without risking product warranty. The approach is applicable to systems incorporating both hardware and software elements. The methodology has been validated on three development projects of telecommunication systems comprising hardware and software. In addition to enhancing team behaviour and performance, the development times have been reduced by 14% and the ramp‐up time to full worldwide product shipments has been reduced by 50%. Copyright © 2005 John Wiley & Sons, Ltd.     

Hot-nanoparticle-mediated fusion of selected cells

Complete fusion of two selected cells allows for the creation of novel hybrid cells with inherited genetic properties from both original cells.Alternatively,via fusion of a selected cell with a selected vesicle,chemicals or genes can be directly delivered into the cell of interest,to control cellular reactions or gene expression.Here,we demonstrate how to perform an optically controlled fusion of two selected cells or of one cell and one vesicle.Fusion is mediated by laser irradiating plasmonic gold nanoparticles optically trapped between two cells (or a vesicle and a cell) of interest.This hot-particle-mediated fusion causes total mixing of the two cytoplasms and the two cell membranes resulting in formation of a new hybrid cell with an intact cell membrane and enzymatic activity following fusion.Similarly,fusion between a vesicle and a cell results in delivery of the vesicle cargo to the cytoplasm,and after fusion,the cell shows signs of viability.The method is an implementation of targeted drug delivery at the single-cell level and has a great potential for cellular control and design.     

Mealtime Behaviors and Food Consumption of Perceived Picky and Nonpicky Eaters through Home Use Test

Picky eating has been investigated through numerous surveys and food recalls, but few studies have applied in‐home meal evaluations as a method to investigate behaviors and food preferences of children perceived by their parent to be a picky eater (PE) or nonpicky eater (NPE). A 2‐wk in‐home meal study was completed to investigate differences in PE and NPE mealtime behaviors and food selections using real‐time parental observations. Parents (n = 170) and their 2‐ to 4‐y‐old children (83 PE and 87 NPE) evaluated 5 standardized meals in‐home. Parents recorded their child's and their own hedonic liking of the products and completed an assessment of their child's behavior and consumption at each meal. Significant differences were found between perceived PE and NPE children for all 16 behaviors assessed. On average, perceived NPE were assessed to consume a higher percentage of the meal served and to have higher acceptance scores for most of the foods evaluated. Some foods, though, like breaded chicken and plain pasta, were liked equally by PE and NPE. Several significant differences in hedonic liking were revealed when PE children were compared to their parents. Yet, few differences in liking occurred between NPE children and their parents or between the 2 parental groups. Because study participants evaluated meals real‐time rather than memory recall, the differences and similarities found between perceived PE and NPE may be considered direct experiential evidence with reduced subjective bias as created when subjects recall past experiences. Thus, findings from this study can provide the foundation to establish an objective definition and classification of PE and NPE.