Biodegradation of alpha-pinene in model biofilms in biofilters

Treatment of air pollutants in a biofilter requires that the compound be effectively transported from the gas phase to the organisms that reside in a biofilm that forms upon a packing material. Models of biofiltration generally treat the biofilm like water by using a Henry's law constant to predict mass transfer rates into the biofilm where degradation occurs and, hence, predict low rates for hydrophobic compounds. However, some compounds that are virtually insoluble in water are also treated unusually well. The objective of this study was to develop a fundamental understanding of the apparent enhanced degradation of hydrophobic pollutants in biofilms. Specifically, the goals of this study were to experimentally determine transport and reaction rates of hydrophobic pollutants in artificial biofilms. We studied the transport and reaction rates of alpha-pinene (as a model hydrophobic pollutant) in a headspace in contact with a well-defined biofilm made up of biomass immobilized in low melting point agarose and found that reaction rates were similar in order of magnitude to biofilter rates. The transport rates through these films once deactivated were found to be the same as through agar (diffusion coefficient between 2.6 and 3.4 x 10(-6) cm2/s). The degradation rates through model biofilms ranged from 2 to 4 x 10(-7) (g/(cm2 min)). A new explanation of high degradation rates was put forth whereby a biologically mediated transformation is taking place in which alpha-pinene is oxidized into a more soluble, less volatile compound that can then penetrate deeper into the biofilm. The formation of this more soluble byproduct was confirmed with batch kinetics experiments using filtered samples, and its proposed identity is cis-2,8-p-menthadien-1-ol, a menthadienol, a novel metabolite of alpha-pinene degradation. A simple conceptual model based on these results is also presented.     

Continual association as a function of level of creativity and type of verbal stimulus.

Continual word association was studied as a function of Remote Associates Test (RAT) performance, form class, associative hierarchy, and Thorndike-Lorge word frequency. Ss were selected as high creative (HC), low creative (LC), and medium creative (MC) on the basis of their RAT scores. It was found that HC Ss give the greatest number of associations and maintain a relatively higher speed of association throughout a 2-min. period. More responses were elicited by nouns than adjectives, flat hierarchy words than steep, and high frequency words than low. The S and stimulus variable did not interact. Relevance to an associative theory of creative thinking is discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Heat transfer during the rewetting of hot horizontal channels

The heat transfer in the rewetting of hot horizontal channels is investigated. The physical model assumes an inclined rewetting front advancing at a uniform velocity. Precursory cooling in the dry region is considered. Three-dimensional energy equations are solved numerically by a finite difference method. Further, the axial and circumferential temperature distributions are predicted. The influence of various parameters on the rewetting velocity is analyzed, as are the variations of the different heat transfer mechanisms, convection to the fluid and conduction in the three-dimensions, as a function of time.     

Are clinical psychologists prepared for service and research with ethnic minorities? Report of a decade of progress.

Longitudinal data on the status of training of clinical psychologists for service and research with ethnic minority populations were presented to assess progress. Data from an earlier survey by M. E. Bernal and A. M. Padilla (see record 1983-06520-001), which were collected in 1979–1980, were compared with similar survey data collected in 1990–1991. Results revealed a mixed picture of progress: key aspects of minority training have improved, and there is a substantial block of programs committed to minority training. However, 2 changes are needed: engagement in a change process leading to training for cultural competence rather than minimal exposure to culture, and a significant increase in the numbers of minority faculty, which can occur only by a sharp increase in the numbers of minority students admitted into the educational pipeline. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dissociated overt and covert recognition as an emergent property of a lesioned neural network.

Covert recognition of faces in prosopagnosia, in which patients cannot overtly recognize faces but nevertheless manifest recognition when tested in certain indirect ways, has been interpreted as the functioning of an intact visual face recognition system deprived of access to other brain systems necessary for consciousness. The authors propose an alternative hypothesis: that the visual face recognition system is damaged but not obliterated in these patients and that damaged neural networks will manifest their residual knowledge in just the kinds of tasks used to measure covert recognition. To test this, a simple model of face recognition is lesioned in the parts of the model corresponding to visual processing. The model demonstrates covert recognition in 3 qualitatively different tasks. Implications for the nature of prosopagnosia, and for other types of dissociations between conscious and unconscious perception, are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Perception of Beer Flavour Associates with Thermal Taster Status

Beer flavour, and thus much of the consumer experience of beer, is determined by the sensations elicited when it is taken into the mouth. Thus, individual differences in the perception of these oral sensations may contribute to the variation in consumer behaviour. A new taste phenotype shown to associate with the intensity of oral sensations elicited by simple solutions is thermal taster status (TTS). Thermal tasters (TTs) perceive ‘phantom’ tastes with thermal stimulation of the tongue, while thermal non‐tasters (TnTs) do not. Here, we investigate the effect of TTS on the perceived intensity of bitterness, sourness, sweetness, fullness, carbonation and overall flavour intensity elicited by seven beers representing classic styles — wheat beer, brown ale, pale ale, low‐alcohol lager, standard lager, high‐alcohol lager and stout. A strong trend was observed for TTs (n = 20) to rate attributes higher than TnTs (n = 20) for all beers except the stout, with these differences significant in many instances (ANOVA or binomial analysis). It is concluded that TTS may be an important determinant of individual differences in the perception of beer flavour, but beer liking and preference are more complex phenomena than can be accounted for by this phenotype alone.     

伦敦的未来木材码头

玛莎·舒瓦茨合伙人有限公司目前正为英国伦敦金丝雀友码头地产附近的一处新兴大型综合开发项目做景观设计。金丝雀码头因其高质量的景观处理而备受赞誉。木材码头必须秉承这一优良传统,使用最好的材料和能经得起时间考验的设计手法,项目的关键在于滨水边缘的处理,滨水区域为人们提供珍贵的亲     

Generalised component-based model for beam-to-column connections including axial versus moment interaction

A generalised component-based model for semi-rigid beam-to-column connections including axial force versus bending moment interaction is presented. The detailed formulation of the proposed analytical model is fully described in this paper, as well as all the analytical expressions used to evaluate the model properties. Detailed examples demonstrate how to use this model to predict moment–rotation curves for any axial force level. Numerical results, validated against experimental data, form the basis of a tri-linear approach to characterise the force–displacement relationship of the joint components. The relationship of the present development to key prior studies of this topic is also explained.     

Effect of the reducing agent on the hydrodechlorination of dioxins over 2 wt.% Pd/γ-Al2O3

2-Propanol and molecular H₂ (in methanol (MeOH) and MeOH–water) were examined as reducing agents for the liquid phase hydrodechlorination (HDC) of dioxins over 2 wt.% Pd/γ-Al₂O₃. Different amounts of NaOH were added to the reaction mixtures. The 2-propanol and H₂(g)/MeOH systems presented similar HDC activity. Notwithstanding, Pd sintering and graphitic carbon directly bonded to Pd on catalyst surface was observed on samples used with H₂(g)/MeOH. The addition of water to H₂(g)/MeOH decreased Pd sintering and favored dissolution of sodium compounds. However, dioxin degradation efficiency diminished. By contrast, 2-propanol acting both as reducing agent and solvent provided hydrogen to the HDC reaction, avoided metal sintering and Pd–C formation. Besides, almost complete dioxin degradation under mild reaction conditions was obtained. Kinetic experiments of dioxin HDC with 2-propanol showed a maximum net reaction rate and turnover frequency (TOF) for a given initial concentration of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs). After that value, both reaction rate and TOF decreased. On the other hand, reaction rates and TOFs of dioxin-like polychlorinated biphenyls (DL-PCBs) linearly increased with concentration.