The Lake Manzala of Egypt: an ambiguous future

The Lake Manzala of Egypt has a relatively short history and its future, however, is uncertain. The lake which was the biggest coastal wetland along the Mediterranean Coast is moving toward its disappearance by two opposite forces, one of them is the shrinking of the water body by siltation of sediments coming from agricultural lands and the abundance of weeds and swamp vegetation as well as the drying practices for agriculture, whereas the other force incorporates the removal of the coastal sand bar separating the lake from the Mediterranean Sea by erosion, which should eventually lead to the conversion of the lake into a coastal embayment instead of being a closed coastal lagoon. The study provided a spatiotemporal change analysis of the lake using remotely sensed data.     

Application of a square wave potentiometry technique for electroreductive sulfur removal from a thiophenic model fuel

Thiophene-containing solutions were electroreductively desulfurized by a dynamic method. Initially, cyclic voltammetry was utilized to study thiophene electroadsorption from aqueous solution onto a platinum electrode surface and also to investigate the thiophene electroreductive behavior. Then, the solution was desulfurized via a square wave potentiometry method. The objective of this study was to find the optimal conditions. In this regard, the best adsorption potential, electroreduction potential, and square wave frequency were found to be ?0.54 V, ?0.95 V, and 1 Hz, respectively. Finally, a model fuel (containing 294 part per millions thiophene) was desulfurized by the square wave potentiometry method. Gas chromatography and Fourier transform infrared spectroscopy were used to examine the feed and product solutions. Gas chromatographic measurements revealed that sulfur content decreased to 55 part per millions. Based on the acquired results, electroreductive desulfurization could be designated as an efficient superseded for the commercial hydrodesulfurization process. However, more studies must perform to overcome technical limitations of electroreductive desulfurization technique and to guarantee its reliability.     

Heat capacity,compressibility and thermal expansion coefficient of ilmenite-type MgGeO3

The accuracy of differential scanning calorimetry (DSC) on a heat capacity measurement was evaluated using MgO. The result indicated that the deviation of the result in comparison to literature values was less than 0.4% at temperatures above 300 K and 2.1% below this temperature. Since this experiment proved the reliability of DSC, heat capacity, compressibility, and thermal expansion of ilmenite-type MgGeO₃ were measured by means of DSC, a diamond anvil high pressure device, and a high-temperature X-ray camera, respectively. The heat capacity was approximated by C _p = a + b·T + c·T ^?2 at high temperatures and by the Debye function at low temperatures. The compressibility was well-represented by the Murnaghan-Birch equation of 2nd order. The thermal expansion coefficient was constant up to 1073 K.     

Ultrastructure of a microbial mat-generated phosphorite

Optical and SEM observations of phosphorites reveal that mineralization is concentrated on ooids and micro-oncoids. The coated grains occur within microbial mats. Microbial mats represent the formational environment of the ooids and oncoids. Both coated grains and mats exhibit similar filamentous micro-organisms. The mat filaments show no fixed orientation and they merge with the concentrically oriented filaments of the coated grains. The branching nature and chlamydospore-like structures of filaments suggest that both mat and coated grains have been formed by fungi. Some coated grains appear to have been slightly disturbed and sometimes mobilized from their sites of formation due to separation from the parent mat resulting perhaps from contraction/fragmentation. The voids so created within the mat had been later filled with either micrite or sparite.     

Physical Libration of the Moon: An Extended Problem

Astronomy Reports - The work is devoted to the study of the physical libration of the Moon. Interest in the traditional topic related to the rotation of the Moon is stirred up by the activity of...