Phytoremediation of effluents from aluminum smelters: a study of Al retention in mesocosms containing aquatic plants

Four mesocosms were exposed to circumneutral and aluminum (Al)-rich wastewater during two successive summers (2000, 2001). The goals of the study were to measure the bioaccumulation of dissolved Al by the aquatic plants Typha latifolia, Lemna minor, Nuphar variegatum and Potamogeton epihydrus, and to evaluate their importance in the retention of Al by the mesocosms. In 2000, inlet concentrations of total monomeric Al were reduced by 56% and 29% at the Arvida and Laterrière mesocosms, respectively, whereas in 2001 inlet dissolved Al concentrations in the inlet decreased by 40% and 33%. L. minor had the highest Al uptake rate (0.8--17 mg Al g(-1)d(-1)). However, because T. latifolia (cattails) yielded the highest biomass, it was responsible for 99% of the Al uptake, largely in its root tissue. In 2001, Al uptake by macrophytes accounted for 2--4% and 15--54% of the total Al retained by the Laterrière and Arvida mesocosms, respectively. In the Laterrière mesocosms, Al uptake by cattails could account for 12% and 18% of the dissolved Al retained by both mesocosms. In contrast, dissolved Al was not significantly reduced in the Arvida enclosures, yet cattails did accumulate Al in their roots. Further research is needed to identify the species community composition that would optimize dissolved Al retention.     

Hypergeometric Functions and Parabolic Partial Differential Equations

We investigate the summability of formal power series solutions of parabolic linear partial differential equations with exponential coefficients.2000 Mathematics Subject Classification. 35C10, 35C20.This research was supported by a Marie Curie Fellowship of the European Community program Improving Human Research Potential under contract number HPMF-CT-2002-01818.     

The equivalent temperature coefficient of resistance of thin film resistor-conductor structures

Using the basic definition of the temperature coefficient of resistance (TCR), we developed a theoretical method for estimating the effect of the high TCR of conductors on the final TCR of resistor-conductor systems.

To investigate the relations developed, we studied several thin film resistors on various substrates. The experimental results for the combined TCR of the resistor-conductor systems correspond well with the theoretically predicted values.     

Hypnotic time distortion and learning: Another look.

Conducted 2 studies employing different methodologies with a total of 75 undergraduates to test the hypothesis that hypnotic time distortion facilitates verbal learning. All of the Ss in Exp I and most of those in Exp II were given a modified version of the Stanford Hypnotic Susceptibility Scale-Form C. All Exp II Ss were also given the Harvard Group Scale of Hypnotic Susceptibility. Analysis of previous research indicated that hypnotic susceptibility and the form of the time-distortion suggestions might be important moderator variables in the relationship. The separate and combined effects of these variables were observed in both studies. No combination of hypnotic susceptibility and time-distortion suggestions in either study raised performance level beyond that of the waking- and/or hypnotic-control conditions. Responses to a postexperimental questionnaire in Exp II indicated that high-susceptible Ss reported subjectively convincing changes in experienced time flow following time-distortion suggestions. (12 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The decomposition of wustite under mixed chemical reaction/mass transport limitations

Numerical solutions have been obtained for the mixed chemical reaction/diffusion limited planar decomposition of a wustite slab prior to iron metal nucleation. The results of the analysis are presented in dimensionless parameters and predict the iron concentration profile within the slab during decomposition, the total loss of oxygen from the sample, and the concentration of iron at the gas/wustite interface, as a function of time. The formulation of the problem allows solutions to be obtained for reduction in H₂/H₂O or CO/CO₂ gas mixtures at reaction temperatures between 873 K and 1573 K.     

Patient behavior in hospitals: Helplessness, reactance, or both?

48 male inpatients hospitalized for 1, 3, or 9 wks and 24 male outpatients (mean age of all Ss, 39.9 yrs) were tested on cognitive tasks; poor performance and depressive symptoms increased with length of hospitalization, even as illness resolved. Further, increased hospitalization made patients more susceptible to the debilitating effect of uncontrollable events. Taken together, these results imply that the passive, compliant, and inanimate behavior of the "good patient" may be the result of learned helplessness engendered by hospitalization. (25 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sur l'utilisation des modifications de barrière de surface avec la température pour caractériser les états de surface

This paper deals with the determination of the density and the energy level of semiconductor surface states from the variations in the surface barrier height with temperature in the range 100–400 K. Examples of calculations for discrete energy level states are given.