Solution-processable graphene linked to 3,5-dinitrobenzoyl as an electron acceptor in organic bulk heterojunction photovoltaic devices

3,5-Dinitrobenzoyl chloride was covalently linked to graphene oxide (GO) nanosheets prepared by a modified Hummers’ method, using ethylenediamine as a spacer. The linkage of the GO with the small molecule was confirmed by spectroscopic (e.g., Fourier transform infrared, Raman) and microscopic analyses. The resultant GO-ethylene-dinitro-benzoyl (GO-EDNB) consists of a controlled scale of different graphene structures and is highly dispersable in common organic solvents. The GO-EDNB was used as the electron acceptor material in poly-(3-hexylthiophene) (P3HT) bulk heterojunction photovoltaic devices to significantly improve the performance, yielding a power conversion efficiency improvement of two orders and one order of magnitude compared with the pristine P3HT and the P3HT-GO devices respectively.     

The effect of biomass adsorption on the removal of selected pharmaceutical compounds in an immersed membrane bioreactor system

BACKGROUND: The performance of a pilot membrane bioreactor system (MBR) was tested for the treatment of municipal wastewater, with emphasis on the capability for removal of selected pharmaceuticals RESULTS: The MBR showed excellent performance with regards to conventional pollutants. However, the removal of specific pharmaceuticals was not as high. Carbamazepine and 17 α‐ethinyl estradiol showed the lowest removal, with mean removal rates of around 20%. Clofibric acid showed the highest removal 70%, while for 17β‐estradiol the mean removal was 40%. In order to distinguish between the two basic mechanisms of removal, adsorption on biomass and biodegradation, adsorption studies on inactivated biomass were performed and mass balances were written for the four pharmaceuticals. The immediate removal observed for the three compounds during short hydraulic retention times may have been primarily due to adsorption. CONCLUSIONS: The removal of carbamazepine, 17β‐estradiol and 17α‐ethynil estradiol, as well as half of the removal of chlofibric acid could be attributed to direct adsorption on biomass within the hydraulic residence time of the reactor. Copyright © 2011 Society of Chemical Industry     

Urban vegetational change as an indicator of demographic trends in cities: the case of Detroit

"In this study the author seeks to find whether changes in urban vegetation can be linked to urban social changes by using Detroit [Michigan] as a case study. Demographic trends in Detroit are analyzed in light of the increasing greenness in the city detected by recent satellite images. Robust relationships between greenness change and demographic factors associated with urban decay (population decline, an increase in poverty level, and an increase in vacant units) are found.... It is concluded that vegetation trends could be used as indicators of urban socioeconomic changes. A vegetation-based urban environmental quality index could therefore be developed to monitor physical and social changes in the cities."     

Spontaneous emulsification aspect of enhanced oil recovery

Recent studies have suggested the possibility of spontaneous emulsification as a mechanism for enhanced oil recovery (EOR). The discussions have, however, remained essentially qualitative. A study was therefore undertaken to estimate quantitatively the contribution of spontaneous emulsification as an EOR mechanism. The tests were conducted on several bulk liquid/liquid systems as well as by displacement experiments in unconsolidated synthetic sand packs. Spontaneous emulsification was found to be a mechanism for EOR: the estimated extra contribution to EOR due to this mechanism was found to be significant in laboratory scale displacement experiments. Tertiary recovery was always greater when spontaneous emulsification was evident than otherwise. Results of tests on bulk liquid/liquid systems indicate that the occurrence or absence of spontaneous emulsification can be correlated with the values of ‘partition parameter’. It may be concluded that higher oil recoveries may be achieved in chemical EOR processes where interface mass transfer (and the accompanying spontaneous emulsification) occurs. The evaluation of efficiency of residual oil mobilisation through the capillary number theory (with and without spontaneous emulsification) is also discussed. Displacement tests with spontaneously emulsifying systems showed that residual oil left behind a conventional waterflood was mobilised in a range of capillary numbers much less than that which applies to low-tension waterfloods.     

The Addiction-Stroop test: Theoretical considerations and procedural recommendations.

Decisions about using addictive substances are influenced by distractions by addiction-related stimuli, of which the user might be unaware. The addiction-Stroop task is a paradigm used to assess this distraction. The empirical evidence for the addiction-Stroop effect is critically reviewed, and meta-analyses of alcohol-related and smoking-related studies are presented. Studies finding the strongest effects were those in which participants had strong current concerns about an addictive substance or such concerns were highlighted through experimental manipulations, especially those depriving participants of the substance. Theories to account for addiction-related attentional bias are discussed, of which the motivational theory of current concerns appears to provide the most complete account of the phenomenon. Recommendations are made for maximizing the precision of the addiction-Stroop test in future research. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Bayesian Robot Programming

We propose a new method to program robots based on Bayesian inference and learning. It is called BRP for Bayesian Robot Programming. The capacities of this programming method are demonstrated through a succession of increasingly complex experiments. Starting from the learning of simple reactive behaviors, we present instances of behavior combination, sensor fusion, hierarchical behavior composition, situation recognition and temporal sequencing. This series of experiments comprises the steps in the incremental development of a complex robot program. The advantages and drawbacks of BRP are discussed along with these different experiments and summed up as a conclusion. These different robotics programs may be seen as an illustration of probabilistic programming applicable whenever one must deal with problems based on uncertain or incomplete knowledge. The scope of possible applications is obviously much broader than robotics.     

Stiffness properties and stiffness orientation distributions for various paper grades by non-contact laser ultrasonics

The stiffness properties, especially flexural rigidity (FR), out of plane shear rigidity (SR), and stiffness orientation distributions (SOD) are characterized for various paper grades, by a laser ultrasonics instrument. Laser ultrasonics generation is achieved through thermal dilatation by point focusing of a pulsed laser beam onto the surface of the specimen. By probing the excited broadband ultrasound propagating in the samples, the velocities dispersions are obtained and the materials properties are extracted. The measured FR and SR along machine direction (MD) and cross direction (CD) are presented for 10 paper samples ranging from thin copy papers to heavy linerboards. The SOD polar diagrams for some of the samples are also presented and discussed. The relationships of FR, SR, Young's and shear moduli with basis weight are discussed. It is observed that both the Young's and shear moduli tend to decrease significantly when the basis weight increases, going from copy paper to linerboard grades. We also found that SR reaches a maximum value and then decreases when the basis weight increases to 150 g/m² and above. This unusual behavior of SR can be explained by the noticeable reduction of shear modulus for heavy linerboards.