Development of a Surface Area Dependent Rate Expression for Soot Oxidation in Diesel Particulate Filters

We collected soot from diesel engine exhaust on miniature particulate filter samples and evaluated soot oxidation rates on an automated flow reactor system. A series of isothermal pulsed oxidation experiments quantified reaction rates as a function of gas composition, temperature, flow rate, and soot consumption. An O₂ chemisorption method measured the soot active surface area as filter regeneration progressed. We developed a rate law with an explicit dependence on carbon surface area and estimated the associated kinetic parameters from the pulsed oxidation data. The resulting rate expression successfully captures the soot oxidation behavior over a wide range of operating conditions.     

Ultrasonic properties and morphology of devulcanized rubber blends

The ultrasonic properties of two devulcanized rubber (DR) blends with a styrene‐butadiene‐styrene (SBS) copolymer compound (ACE) are investigated using a transmission method. The DR materials are obtained from commercial rubber crumbs (RC) by a proprietary devulcanization technique. Measurements on the acoustic attenuation and travel velocity are conducted on the samples with different sample thicknesses in the pulsed mode. Attenuation coefficients of the materials are obtained by changing the frequency of the ultrasound in the tuned tone‐burst mode. The two DR/ACE blends show marked differences in the attenuation and attenuation coefficient, although the ultrasonic velocities are similar. These differences arise from the variation of the remaining degree of crosslinking in the DR materials. The acoustic velocities in the three materials are similar. The morphologies of the DR/ACE blend samples, observed using scanning electron microscopy (SEM) with different staining agents, explain their similarities and differences. There are two crops of rubber particles: larger ones belong to the original rubber crumbs that survived devulcanization; the smaller ones are fragments of partially DR. These crosslinked particles contribute to the overall degree of crosslinking in the blends. The devulcanized fractions of the DR materials are dispersed in the ACE matrix. Scattering at the interface accounts for the differences in the acoustic attenuation of the samples. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Service Priorities and Balance: Delivering a Menu of Quality Services That Reflect Users Needs and Tastes

ABSTRACT

With the increasing use of technology, librarians are being asked to provide instruction in a variety of different formats. One way for academic librarians to meet the demand of teaching is for them to take a closer look at what is written in the educational literature about teaching. This article reviews eight academic Web sites that deal with teaching effectiveness and describes their usefulness for librarians and others interested in teaching.     

Advancement of Fischer‐Tropsch synthesis via utilization of supercritical fluid reaction media

The Fischer Tropsch Synthesis (FTS) reaction has been studied and for nearly a century for the production of fuels and chemicals from nonpetroleum sources. Research and utilization have occurred in both gas phase (fixed bed) and liquid phase (slurry bed) operation. The use of supercritical fluids as the reaction media for FTS (SCF‐FTS) now has a 20‐year history. Although a great deal of progress in SCF‐FTS has been made on the lab scale, this process has yet to be expanded to pilot or industrial scale. This article reviews the research activities involving supercritical FTS and published in open literature from 1989 to 2008. © 2009 American Institute of Chemical Engineers AIChE J, 2010     

AOL in trouble on two fronts

The new year has brought problems for America Online on at least two fronts. First of all a group of teenage hackers were able to breach security on AOL Instant Messenger. Then a lawsuit was filed on behalf of its subscribers, claiming the company’s latest software disables any Internet accounts users have with other companies, making them unusable. The suit cites a federal computer crimes law that is generally used to prosecute hackers. That law provides criminal and civil liability for any persons that interfere with another’s computer.     

Microsoft quits AOL messaging battle

Microsoft has backed away from trying to link its instant messaging system with America Online’s similar offering.     

Cross-cultural evidence for the fundamental features of extraversion.

Psychologists have not determined the defining characteristics of extraversion. In four studies, the authors tested the hypothesis that extraversion facets are linked by reward sensitivity. According to this hypothesis, only facets that reflect reward sensitivity should load on a higher order extraversion factor. This model was tested against a model in which sociability links the facets. The authors also tested the generalizability of the model in a diverse sample of participants from 39 nations, and they tested the model using widely used extraversion scales. Results of all studies indicate that only facets that reflect reward sensitivity load on a higher order extraversion factor and that this factor correlates strongly with pleasant affect. Although sociability is undoubtedly an important part of extraversion, these results suggest that extraverts' sociability may be a by-product of reward sensitivity, rather than the core feature of the trait. (PsycINFO Database Record (c) 2010 APA, all rights reserved)