Photocatalysis of xenobiotic organic compounds in greywater using zinc oxide nanoparticles: a critical review

The direct discharge of raw bathroom greywater has increased the concentrations of various pollutants in the water bodies. Typically, greywater contains large quantities of xenobiotic organic compounds (XOCs) owing to an increase in consumption of personal care and bath products. Therefore, it urges for a suitable technology to eliminate these compounds from contaminated waters. Photocatalytic degradation using Zinc Oxide nanoparticles (ZnO NPs) has the potentiality to eliminate various XOCs. However, ZnO NPs have high tendency to aggregate, which may lower the photocatalytic degradation rate. Therefore, there is an urgency to modify ZnO NPs to overcome the limitation. The present review was conducted to determine a suitable method for the modification ZnO NPs. Besides, the potential of the modified ZnO NPs in degrading XOCs in greywater as a photocatalyst was also discussed.     

Food security: perspectives from the Arab World

Editorial

Acknowledgement of reviewers     

Is unilateral breast enlargement always a sign of cancer?

Breast swelling is caused by many etiological factors, but should alert central vein occlusion in hemodialysis patients when the permanent vascular access is in the same arm. The swelling of the breast is caused by venous hypertension in the venous plexus draining the breast. Endovascular treatment relieves venous hypertension and related clinical signs. Additional diagnostic workup or invasive interventions such as a biopsy should be avoided in such patients, as diagnosis is straightforward with the presence of a functioning arteriovenous fistula in the same arm.     

Entropy-based feature selection for improved 3D facial expression recognition

Facial expressions contain most of the information on human face which is essential for human–computer interaction. Development of robust algorithms for automatic recognition of facial expressions with high recognition rates has been a challenge for the last 10 years. In this paper, we propose a novel feature selection procedure which recognizes basic facial expressions with high recognition rates by utilizing three-Dimensional (3D) geometrical facial feature positions. The paper presents a system of classifying expressions in one of the six basic emotional categories which are anger, disgust, fear, happiness, sadness, and surprise. The paper contributes on feature selections for each expression independently and achieves high recognition rates with the proposed geometric facial features selected for each expression. The novel feature selection procedure is entropy based, and it is employed independently for each of the six basic expressions. The system’s performance is evaluated using the 3D facial expression database, BU-3DFE. Experimental results show that the proposed method outperforms the latest methods reported in the literature.     

Generation of free radicals in partial oxidation of coal

Pyrolytic and oxidative treatments of two coals, Illinois No. 6 and Montour, have been performed between 140 and 400 °C. Free radical concentrations were followed by electron paramagnetic resonance as a function of time of treatment at a given temperature. Initial increases in the organic free radical concentrations were observed at all temperatures, but at the higher temperatures termination reactions caused the increase to be transient. Variations in the free radical concentrations of weathered and unweathered coal showed that the former produced a larger number of radicals. Possible effects due to native mineral matter are suggested.     

Searching by rules: Pigeons' (Columba livia) landmark-based search according to constant bearing or constant distance.

Pigeons (Columba livia) searched for a goal location defined by a constant relative spatial relationship to 2 landmarks. For one group, landmark-to-goal bearings remained constant while distance varied. For another group, landmark-to-goal distances remained constant while direction varied. Birds were trained with 4 interlandmark distances and then tested with 5 novel interlandmark distances. Overall error magnitude was similar across groups and was larger than previously reported for Clark's nutcrackers (Nucifraga columbiana). During training, error magnitude increased with interlandmark distance for constant-bearing but not constant-distance birds. Both groups searched less accurately along the axis parallel to landmarks than along the perpendicular axis. Error magnitude increased with novel extrapolated interlandmark distances but not with novel interpolated distances. Results suggest modest geometric rule learning by pigeons. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A comparative study of geometric rule learning by nutcrackers (Nucifraga columbiana), pigeons (Columba livia) and jackdaws (Corvus monedula).

Three avian species, a seed-caching corvid (Clark's nutcrackers; Nucifraga columbiana), a non-seed-caching corvid (jackdaws; Corvus monedula), and a non-seed-caching columbid (pigeons; Columba livia), were tested for ability to learn to find a goal halfway between 2 landmarks when distance between the landmarks varied during training. All 3 species learned, but jackdaws took much longer than either pigeons or nutcrackers. The nutcrackers searched more accurately than either pigeons or jackdaws. Both nutcrackers and pigeons showed good transfer to novel landmark arrays in which interlandmark distances were novel, but inconclusive results were obtained from jackdaws. Species differences in this spatial task appear quantitative rather than qualitative and are associated with differences in natural history rather than phylogeny. (PsycINFO Database Record (c) 2010 APA, all rights reserved)