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Egyptian pea cultivars ( Pisum sativum L. cultivars Little Marvel, Perfection and Victory) grown in open-top chambers were exposed to either charcoal-filtered (FA) or non-filtered air (NF) for five consecutive years (2009–2013) at a rural site in northern Egypt. Net photosynthetic rates ( P N ), stomatal conductance (g s ), intercellular CO 2 (C i ) and chlorophyll fluorescence were measured. Ozone (O 3 ) was found to be the most prevalent pollutant common at the rural site and is suspected to be involved in the alteration of the physiological parameters measured in the present investigation. P N of different cultivars were found to respond similarly; decreases of 23, 29 and 39% were observed in the cultivars Perfection, Little Marvel and Victory, respectively (averaged over the five years) due to ambient O 3 . The maximum impairment in P N was recorded in the cultivar Victory (46%) in 2013 when the highest O 3 levels were recorded (90 nL L − 1 ). The average stomatal conductance decreased by 20 and 18% in the cultivars Little Marvel and Perfection, respectively, while the average stomatal conductance increased on average by 27% in the cultivar Victory. A significant correlation was found between P N and C i , indicating the importance of non-stomatal limitations of photosynthesis, especially in the cultivar Victory. The P N vs. Ci curves were fitted to a non-rectangular hyperbolic model. The actual quantum yield (Φ PSII ) and photochemical quenching coefficient (qP) were significantly decreased in the leaves of plants exposed to NF air. Non-photochemical quenching (NPQ) was increased in all cultivars. Exposure to NF air caused reductions in chlorophyll (Chl a ) of 19, 16 and 30% in the Little Marvel, Perfection and Victory cultivars, respectively. [ABSTRACT FROM AUTHOR]

Abstract: Three titanium oxynitride films have been prepared by vacuum arc discharge technique at different chamber temperatures (50°C, 150°C and 300°C). X-ray photoelectron spectroscopy was used to reveal the elemental and chemical compositions by analyzing high resolution spectra of Ti 2p3/2, N 1s and O 1s. Higher temperatures were found to promote the nitride components and to produce nitrogen-rich films. Homogeneity and thickness of the films have been estimated by means of Rutherford Back Scattering technique, which showed that the film thickness increased with the increasing of temperature. A significant improvement in the crystalline quality and texture when increasing the temperature was found by X-ray diffraction technique. Electrical resistivity of the films was measured at room temperature and was found to decrease from 46.6μΩcm down to 26.3μΩcm for the samples prepared at 50°C and 300°C, respectively. [Copyright &y& Elsevier]

Abstract: Manganese leaching and recovery from pyrolusite ore, was investigated by using H2SO4 as a leachant and H2O2 as a reducing agent. The effects of agitation, H2O2 concentration, H2SO4 concentration, liquid/solid mass ratio, leaching time and reaction temperature on manganese recovery were studied. The optimal leaching conditions were determined as 4.0M H2SO4 and 0.8M H2O2 using liquid–solid mass ratio of 5.0 for 90min at 40°C and ore particle size of 44–37μm. Under these conditions, the leaching efficiency was 92.0% for Mn. It was found that the use of H2O2 as a reducing agent for the reductive leaching of manganese increased the leaching rate. Analysis of the experimental results indicted that the leaching process is fitted by a chemical reaction model in temperature range 20–40°C, and at higher temperature, 45–70°C, the diffusion reaction model prevails. Activation energies for these models were calculated to be 49.5kJ∙mol−1 and 10.6kJ∙mol−1, respectively. Based on the experimental results, a separation method and flow sheet were developed and tested to separate high purity MnSO4.H2O (>99.4%). Comparison between the present results and that reported in the literature are given. [Copyright &y& Elsevier]

Abstract: Proton induced X-ray emission (PIXE) has been used to measure trace elements in sediments of Orontes River. Measurements were carried out using a 2MeV proton beam produced from of the 3MV tandem accelerator. Sediment samples were collected from 11 sites covering the important potential pollution sources at the river. The accuracy of the experimental procedure was verified using a certified sediment reference material (IAEA-SL1) and was found to be less than 10%. The results have shown that Pb and As were within the natural levels. In contrast, high concentrations of other elements like Cr, Cu, Ni and Zn have been found at different sites and explained by local human and industrial activities. [Copyright &y& Elsevier]

The feasibility of using magnetic nano-zeolite (MNZ) to remove cesium and strontium from their binary corrosive solutions was investigated by considering the multi-variant/multi-objective nature of the process. RSM (Response Surface Methodology) and ANN (Artificial Neural Network) were used to model and optimize the removal system and assess sensitive parameters that can affect the process reliability. MNZ is characterized by its high surface area and cation exchange capacity and possesses good regeneration behavior for both elements using citric acid. Its stability is comparable to other sorbents in acidic media and the stability increases in alkaline media, where dissolution rate follow first order reaction on heterogeneous sites. MNZ removes both contaminants simultaneously with small tendency toward Cs, where MNZ is suggested for application in pre-treatment of highly contaminated alkaline solutions. The percentage removal, decontamination factors, and separation factors have different dependency on the effluent/process conditions; this dependency is the same for both contaminants. Sorption kinetics is initially controlled by external mass transfer through the boundaries then intra-particle diffusion dominates the reactions. The process sensitivity to pH changes is attributed to changes in structural elements -species distribution at the solid/aqueous interface. Cs+ and Sr+2 are exchanged with Na+ and H+, regardless the effluent pH value, and with Al and Fe cations at specific pH. Isosteric heat of sorption calculations indicated that the total heat needed to complete the reaction was considerably reduced by operating the process at optimized temperature. • Cs and Sr are removed simultaneously with a small tendency toward Cs. • MNZ is recommended for pre-treatment of highly contaminated alkaline solutions. • ANN stability is important in deciding on system reliability and process sensitivity. • Altered structural element spices at solid/liquid interface cause process sensitivity. [ABSTRACT FROM AUTHOR]

In this paper, a feasibility study is carried out in order to investigate the description, working principles of the solar parabolic dish systems worldwide, and their potential use in some countries are given. A study of the system is presented, which able to show the performance of the system and accounting for the main technical aspects of the concentrator, receiver and Stirling engine. The study reviews the parabolic solar dish technologies and the design factors adapted in different applications such as material of the reflector concentrators, shape of the reflector concentrators and the receiver, solar radiation at the concentrator, diameter of the parabolic dish concentrator, sizing the aperture area of concentrator, focal length of the parabolic dish, the focal point diameter, sizing the aperture area of receiver, geometric concentration ratio, and rim angle. In order to identify the optimum design feasible option for installation of the solar dish plants, the technical characteristics of some implemented solar dishes worldwide are presented. The study take into consideration available solar potential and the different designs of solar dishes. [ABSTRACT FROM AUTHOR]

Airborne concentrations of Polycyclic Aromatic Hydrocarbons (PAH), quinone and nitro derivatives have been measured at three sites on the coast of Saudi Arabia to the north of the city of Jeddah. The PAH show a general reduction in concentrations from northwest to southeast, consistent with a source from a petrochemical works to the northwest of the sampling sites. In comparison, the concentrations of quinones show little variation between the sampling sites consistent with these being predominantly longer lived secondary pollutants formed from PAH oxidation. The nitro-PAH show a gradient in concentrations similar to but smaller than that for the PAH suggesting a balance between atmospheric formation and removal by photolysis. The 2-nitrofluoranthene:1-nitropyrene ratio increases from north to south, consistent with atmospheric chemical formation of the former compound, while the ratio of 2-nitrofluoranthene:2-nitropyrene is consistent with hydroxyl radical as the dominant reactant. An investigation of the changes in PAH congener ratios during air mass transport along the Red Sea coast shows consistency with reaction with a relatively low concentration of hydroxyl radical only for the day with the highest concentrations. It is concluded that while PAH degradation is occurring by chemical reaction, emissions from other locations along the air mass trajectory are most probably also leading to changes in congener ratios. [ABSTRACT FROM AUTHOR]