Metalloporphyrins in Oxidative Catalysis. Oxygen Transfer Reactions of Oxochromium Porphyrins

The oxidation of chloro-5-10,15,20-tetramesitylporphyrinotoiron(III) with peroxyacids affords a reactive oxoiron(IV)-porphyrin cation radical species 2. The characterization of 2 and its oxochromium analogs 3, 4 and 5 are reviewed. The nature of reactive oxochromium species derived from chromyl reagents is also reviewed. The oxidation of triphenylphosphine by CrOTPP (11), CrOTTP (13) and CrOTMP (14) is described. Variations in the rate constants indicate that steric factors affect the rate of oxygen atom transfer. Activation parameters for the oxidation of triphenylphosphine by 14 are ΔH^≠ = 6.96 kcal/mol and ΔS^≠ = −39 eu. The oxidation of t-butylphenylcarbinol (18) by CrOTPP gave predominantly benzaldehyde via carbon—carbon bond cleavage while the chromium(III) porphyrin-catalyzed oxidation of 18 by iodosylbenzene afforded t-butylphenylketone.     

Improved Matrix-Filler Adhesion

Enhanced matrix-filler adhesion is realized after filler treatment with a surface treatment process. The hydrosol/coupling agent treatment was applied to a wide range of inorganic and organic fillers, and adhesion to a variety of matrix resins was improved. Scanning Electron Microscopy (SEM) was used to determine the locus of failure in the filled systems. The locus of failure shows the relative degree of adhesion between the filler and the polymer matrix. Significant improvement in adhesion in humid environments is also observed.     

Hippocampal lesions impair memory of short-delay conditioned eye blink in rabbits.

Involvement of hippocampus in short-delay eye blink conditioning was reexamined during conditioned response (CR) consolidation. Rabbits received bilateral hippocampectomy, removal of overlying neocortex, or sham lesions and were trained with tone/puff pairings to early acquisition (consolidation) or well trained (overtraining); retention was tested. Two effects were observed: (1) Rabbits with hippocampal lesions showed less retention in the consolidation experiment than controls. Previous studies may not have found this because initial training was more complete. Overtrained hippocampal rabbits showed more retention, which agrees with this suggestion. (2) Hippocampectomized rabbits showed larger CR amplitudes in the overtraining experiment. The complementary roles of hippocampus in the consolidation process during early learning and in modulating the expression of the amplitude/time course of behavioral CRs after associations are well learned are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Social environmental selection as a mediator of gender, ethnic, and personality effects on college student drinking.

Structural equation modeling was used to test the mediational role of social environmental selection on alcohol use in cross-sectional samples of 447 students from a rural state university and 421 students from an urban private university. Results showed that male gender, White ethnicity, and sensation seeking were uniquely associated with greater alcohol use. Mediational analyses indicated that socioenvironmental factors (i.e., Greek involvement, friends' approval of drinking/getting drunk) were positively associated with alcohol use and significantly accounted for parts of the effects of ethnicity and sensation seeking, but not gender, on alcohol use. Results suggest that White students and those high on sensation seeking may drink more heavily in college, in part because they select social environments in which alcohol use is encouraged. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Exceptions that prove the rule--Using a theory of motivated social cognition to account for ideological incongruities and political anomalies: Reply to Greenberg and Jonas (2003).

A meta-analysis by J. T. Jost, J. Glaser, A. W. Kruglanski, and F. J. Sulloway (2003) concluded that political conservatism is partially motivated by the management of uncertainty and threat. In this reply to J. Greenberg and E. Jonas (2003), conceptual issues are clarified, numerous political anomalies are explained, and alleged counterexamples are incorporated with a dynamic model that takes into account differences between "young" and "old" movements. Studies directly pitting the rigidity-of-the-right hypothesis against the ideological extremity hypothesis demonstrate strong support for the former. Medium to large effect sizes describe relations between political conservatism and dogmatism and intolerance of ambiguity; lack of openness to experience; uncertainty avoidance; personal needs for order, structure, and closure; fear of death; and system threat. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Revisiting the need for formal education in visualization.

Defining visualization education is still a work in progress. Visualization education is not just a subject within computer science. Computer scientists are not always the appropriate choice to teach visualization courses on their own. Visualization is not just mastering a set of concepts but acquiring skills. Student should learn by doing, either using one tool or a variety of tools, depending on the course's focus.     

On the complexity of simulating space-bounded quantum computations

This paper studies the space-complexity of predicting the long-term behavior of a class of stochastic processes based on evolutions and measurements of quantum mechanical systems. These processes generalize a wide range of both quantum and classical space-bounded computations, including unbounded error computations given by machines having algebraic number transition amplitudes or probabilities. It is proved that any space s quantum stochastic process from this class can be simulated probabilistically with unbounded error in space O(s), and therefore deterministically in space O(s²).     

Capture of Airborne Particulate Using Surface Applied Emulsions: Potential for Postdetonation Dirty Bomb Cleanup

Recent research has proposed the use of asphalt and tall-oil-pitch emulsions for stabilizing radioactive contamination deposited on surfaces in urban areas. The objective of this project was to investigate whether surface applied emulsions could capture airborne radioactive particulate. Laboratory experiments included wind-blown particulate capture studies using an acrylic column and particulate retainment experiments using a wind box capable of producing wind speeds of 96?km/h. A probe methodology was developed to relate particulate retainment to a tack force on the emulsion surface. Experiments were also performed to determine the potential for such emulsions to absorb particulate matter into their emulsion matrix. Tall-oil-pitch emulsions outperformed asphalt emulsions in terms of particulate retention, tack force, and the ability to absorb magnesium silicate. Both tall-oil-pitch and asphalt emulsions were capable of extracting 22–24?g?m?2 of powder from particulate-laden airflow. Tall-oil-pitch emulsions were capable of retaining as much as 5–10% of magnesium silicate powder applied (i.e., retainment densities of 10–20?g?m?2) even after seven?days of curing and after applying 96.5?km/h (60?mph) wind. Tall-oil-pitch emulsions were able to absorb surface-applied magnesium silicate (approximately 0.1–0.2?g of magnesium silicate per 1.0?g of emulsion within three?days) into their emulsion matrix, preventing the magnesium silicate from being exposed to the external environment. Initial results with these five different emulsion formulations suggested particulate capture was feasible. Future emulsion formulations (i.e., longer curing times with greater acid concentrations) should be tested to optimize this postdetonation response strategy.