Induced chemiluminescence of oxidized fatty acids and oils

The injection of a strong organic base into milligram quantities of fats and oils dissolved in methylene chloride results in a burst of chemiluminescence whose peak intensity is a function of the previous thermal oxidation history and of the degree of unsaturation of the starting material. The flash of this induced chemiluminescence can be 10⁸ times higher than the steady-state “spontaneous” chemiluminescence. The kinetics of the induced chemiluminescence are first order in concentration and second order in time. The emission spectrum is broad and extends into the near infrared. A model based on dioxetane chemiluminescence is proposed to explain the observed kinetics.     

HARDBALL: Local Government’s Foray Into Sports Franchise Ownership

Smaller cities seeking new economic development vehicles have embraced the growth of minor league sports. In an attempt to eliminate the threat of competition and maintain a sense of stability, four local governments purchased their respective minor league baseball franchise. This action may serve as a model for local governments that have invested heavily in professional sports as an economic development strategy. This study investigates the benefits of ownership in terms of stability for development, economic gain, and increased civic spirit. The study finds that publicly owned teams can be successfully used to anchor comprehensive plans for economic development, and that public ownership provides a way to pay the costs of the sports facilities and the debt service. There is little evidence to show that publicly owned teams increase civic spirit. However, this model presents some challenges that may prevent its widespread utilization.     

Does the medium matter? The interaction of task type and technology on group performance and member reactions.

Investigated the hypothesis that as group tasks pose greater requirements for member interdependence, communication media that transmit more social context cues will foster group performance and satisfaction. 72 3-person groups of undergraduates worked in either computer-mediated or face-to-face meetings on 3 tasks with increasing levels of interdependence: an idea-generation task, an intellective task, and a judgment task. Results showed few differences between computer-mediated and face-to-face groups in the quality of the work completed but large differences in productivity favoring face-to-face groups. Analysis of productivity and of members' reactions supported the predicted interaction of tasks and media, with greater discrepancies between media conditions for tasks requiring higher levels of coordination. Results are discussed in terms of the implications of using computer-mediated communication systems for group work. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Water deprivation enhances fear conditioning to contextual, but not discrete, conditional stimuli in rats.

Water-deprived and nondeprived rats were fear conditioned with a discrete tone CS and an aversive footshock unconditioned stimulus/stimuli (UCS). 24 and 48 hrs following conditioning, conditional fear to the tone CS and the context cues of the conditioning chamber, respectively, were assessed by measuring freezing behavior. Water deprivation had no effect on baseline responding to either tone or contextual stimuli. Following either 1 or 3 tone-shock pairings, however, water deprivation selectively enhanced conditional freezing to the contextual cues of the training chamber; conditional freezing to the tone was unaffected by water deprivation. These results are consistent with the view that water deprivation affects fear conditioning via an influence on the hippocampus. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Pulp Pulpits: Self-Disclosure on "Donahue"

This study examines why people choose to self-disclose on "Donahue" and what role television plays in their lives prior to disclosure. Focused interviews were conducted with 29 informants between the ages of 12 and 68 who had appeared on the program. Analysis revealed that an evangelical fervor underpinned their decision, overshadowing other concerns about disclosure in a public forum. Informants generally reported low levels of television viewing. They held a pragmatic view of talk shows as avenues to reach a dual audience that included the mainstream public and members of their out-groups. Television disclosure is a tactic in a counterhegemonic struggle. Respondents utilized numerous impression management techniques in their efforts to manage their stigmatized status. Participants on "Donahue" risk co-optation, but running the gauntlet of criticism and ridicule allows an opportunity for delabeling rarely afforded to out-groups.     

Environmental effects on ductile-phase toughening in Nb5Si3-Nb composites

A variety of materials have been toughened via the addition of a ductile phase. Brittle silicide intermetallics such as Nb₅Si₃ have been significantly toughened by niobium particles incorporated during in-situ processing techniques. In the work described here, toughness tests conducted on Nb₅Si₃ were monitored in a scanning electron microscope to view the process of toughening provided by the niobium particles. In particular, the behavior of the ductile phase was monitored and related to the toughness obtained. In an attempt to vary the behavior of the ductile phase, the composite materials were exposed to a variety of gaseous environments and subsequently tested in air. The resulting toughness, resistance-curve behavior, and in-situ results highlight the importance of the behavior of the ductile phase on subsequent properties.     

Oxygen Tracer Diffusion in Vitreous Silica

Oxygen diffusion in vitreous silica glass is studied using the gas exchange technique. The tracer concentration profiles are consistent with a model based on two mechanisms, one network and the other interstitial. These processes are coupled through limited network–interstitial exchange. Nuclear reaction analysis and secondary ion mass spectrometry techniques are performed and compared. These results are compared to experiments on transport in thin silica films grown on single-crystal silicon.     

A kinematic analysis of the modified flight telerobotic servicer manipulator system

A reverse analysis of a 6 degree of freedom (dof) subchain of a modified 7 dof flight telerobotic servicer (FTS) manipulator system is presented. The 6 dof subchain is designated as a TR-RT* chain. At the outset, it was considered that the reverse analysis would be similar to a TTT manipulator analyzed previously for which the third and fourth joints intersect at a finite point. This was not, however, the case and a sixteenth-degree tan-half-angle polynomial was derived for the TR-RT manipulator. The elimination procedure is interesting and much simpler than the procedures for the general case.     

Investigation of the thermal, mechanical, and fracture properties of alumina-epoxy composites

A combination of dynamic shear rheology, thermomechanical analysis (TMA), scanning electron microscopy (SEM), Near-Edge X-ray Absorption Fine Structure (NEXAFS), and fracture toughness testing was utilized to characterize the thermal, mechanical, chemical, and fracture properties of alumina (α-Al₂O₃)-filled epoxy resins as a function of average filler size, size distribution, particle shape, loading, and epoxy crosslink density. In general the cured properties of the filled composites were robust. Small changes in particle size, shape, and size distribution had little impact on the final properties. Resin crosslink density and filler loading were the most critical variables, causing changes in all properties. However, most applications could likely tolerate small changes in these variables also. SEM and NEXAFS characterization of the fracture surfaces revealed that the fracture occurs at the filler interface and the interfacial epoxy composition is similar to the bulk resin, indicating a weak epoxy-alumina interaction. These results are critical for implementation of particulate-filled polymer composites in practical applications because relaxed material specifications and handling procedures can be incorporated in production environments to improve efficiency.