Synthesis of porous hydrogel structures by polymerizing the continuous phase of a microemulsion

A series of microemulsions have been formulated, with 2-hydroxyethyl methacrylate (HEMA) or HEMA/water/propanol mixtures as the continuous phase and methylcyclohexane as the discontinuous phase. The effect of surfactant type was investigated with the utilization of both anionic and nonionic surfactants. The microemulsion continuous phase was polymerized by UV radiation and a thermal post-cure. The resultant polymers were extracted to remove the discontinuous phase and the surfactant. On swelling, the majority of the polymers became opaque, although transparent PHEMA hydrogels were synthesized with an improved equilibrium water content (EWC). The cause of opacity was shown by field emission scanning electron microscopy (FESEM). The breakdown in the microemulsion on polymerization is caused by unfavourable interactions between the PHEMA and the stabilizing surfactants causing agglomerization of the discontinuous phase. All the hydrogels were found to have higher water retention than PHEMA, with EWCs of up to 70%. The modified polymers also demonstrated an increased rate of water diffusion into the matrix. A preliminary study of oxygen permability revealed that a significant improvement had been made over standard PHEMA membranes. The porous structure of the PHEMA gels has been shown to be dependent on the type of surfactant used during synthesis.     

Thermal Conductivity of a Particulate-Diamond-Reinforced Cordierite Matrix Composite

The effect of 15 vol% particulate diamond reinforcement on the thermal conductivity of a cordierite matrix was studied as a function of diamond particle size from room temperature to 700°C. The thermal conductivity was found to increase with increasing particle size to a maximum increase of about 75% for a mean particle size of 50 μ. The particle size effect was found to be more pronounced at the lower temperatures than at the higher temperatures. The observed effect of particle size and temperature was attributed to the existence of an interfacial thermal barrier, possibly resulting from interfacial phonon scattering, with a positive temperature dependence of the interfacial thermal conductance. The magnitude of this conductance suggested strong adhesion between the diamond and cordierite.     

Effects of attributional retraining on the career beliefs and career exploration behavior of college students.

Two studies were conducted to evaluate the efficacy of attributional retraining as a career counseling technique for college students. Participants who received the attributional retraining treatment viewed an 8-min videotape designed to foster internal, controllable, and unstable attributions for career decision making. Participants in the control groups viewed a similar videotape that lacked any reference to career-related attributions. Results revealed that participants who received attributional retraining exhibited significant changes in career beliefs and attributional style and engaged in significantly more career exploration behavior than the participants in the control groups. An evaluation of attributional retraining as a career-counseling technique for college students is provided, and ideas for further research are suggested. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Observation of bilinear systems with application to biological control

In this paper a system of bilinear equations is derived which under appropriate conditions model the microbial cellgrowth and product formation of various waste treatment and fermentation systems. Given the available measurements, the problem of obtaining an asymptotic estimate of the state of the system is considered. Necessary and sufficient conditions for the observability of a general system of bilinear equations are also derived. As accurate biological sensors do not often exist the results are significant for the on-line control of these biological processes.     

Methodological implications of content-acquiescence correlation in the MMPI.

Attempts to resolve differences remaining between opposed points of view on the importance of acquiescence response bias in the MMPI. On the basis of results in the literature and new data presented, it is concluded that some variance attributable to acquiescence is undoubtedly present in MMPI scores, but that it is small relative to the content variance. Independently corroborated evidence is found that the acquiescence tendency is substantially correlated with 1st factor content in the MMPI. Calculations show that this correlation can account for many of the properties of the MMPI scales which other workers have attributed directly to acquiescence. In the presence of aquiescence-content correlation, a relatively small component of variation due to acquiescence has appreciable effect on (1) the psychometric characteristics of the scales, (2) the selection of items for special scales, and (3) the correlation of certain MMPI scales with independent measures of acquiescence. (25 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Transformation of `bandpass? linear time-variant system into equivalent `lowpass? system

It is shown that a type of `bandpass? linear time-variant differential equation has an equivalent `lowpass? linear time-variant differential equation. The solution of the equivalent equation by computational techniques may proceed at a much higher rate than solution of the original equation, and offers simple computation of the amplitude and phase of the system narrowband response.     

The Feasibility Of Ozone For Purification of Hatchery Waters

Ozone is feasible as a disinfectant of nursery tank makeup water in a planned recycle system at the Dworshak National Fish Hatchery. A dosage of 3 mg/L ozone to the makeup water should prevent disease carrying organisms and algae from entering the nursery tank system by way of the makeup water which is taken from the North Fork of the Clearwater River.     

Cerebral dominance and speech acquisition in deaf children.

In examining the prediction that left cerebral dominance, as indexed by hand and sighting preference, should be a positive accompaniment of speech learning in individuals whose cerebral speech areas are likely to be in the left hemisphere, it was found that over a 10-12 year period of formal education right-handed-right-sighting deaf students consistently earned higher speech grades than their right-handed-left sighting and right-handed-mixed-sighting counterparts matched on the basis of hearing loss. This finding supports the hypothesis that the cerebral mechanisms relevant to speech acquisition are simplified, facilitated, and/or less prone to interference when control of speech, hand, and eye is localized primarily in 1 hemisphere of the brain. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Relationship between job attitudes and two forms of withdrawal from the work situation.

Correlated attitudes concerning the job in general and specific aspects of the work situation with termination decisions and recorded frequency of absences during the year following administration of job attitude questionnaire to 160 nonsupervisory female employees. Overall satisfaction and satisfaction with several intrinsic aspects of the work situation were significantly related to the termination criterion. None of the extrinsic variables were related. For the frequency of absence criterion, attitudes toward specific aspects of the work situation showed no consistent relationships when nonattitudinal variables were partialed out, but overall satisfaction was significantly related. (PsycINFO Database Record (c) 2010 APA, all rights reserved)