Mg-assisted rGO fabrication under microwave irradiation of a natural source of carbon

Chemical reduction of graphene oxide to form reduced graphene oxide (rGO) is a long process that needs time and energy. In this work, we present a facile one-step method to produce rGO using a domestic microwave oven for 2 min. The chemical composition is studied by X-Ray Photoelectron Spectroscopy (XPS), Raman and X-Ray diffraction (XRD) that confirm the formation of rGO. They reveal also the benifit effect of MgCl2 addition towards the rGO formation. Different amounts of MgCl2 are added to polyethylene glycol (PEG) and a natural source of carbon (glucose) is used to form rGO. The rGO yield is successfully enhanced by addition of MgCl2 low concentration. The oxygen concentration decreases with Mg addition which means that Mg atoms replaced oxygen or simply adsorbed at the edge sites. Moreover, carbon concentration increases with MgCl2 addition, which means that Mg acts as an activator of rGO formation. At high MgCl2 concentration, Mg(OH)2-rGO is formed and has a lot of applications

Metastable phase in binary and ternary 12-carat gold alloys at low temperature

Low temperature phase transitions in 12-carat gold alloys have been investigated for binary Au-Cu and ternary Au-Cu-Ag compositions. The thermal analyses investigations using differential scanning calorimetry (DSC) and the dilatometry were performed in the 50-300°C temperature range in order to detect the structural transformations. The thermal analyses were carried out on annealed samples at 700°C for two hour followed by water quenching. They reveal an important new reaction for both used compositions and both thermal techniques confirm each other. This reaction has been assessed as pre-ordering reaction. SEM and STM imaging were performed on annealed samples at 700°C for two hours and water quenched followed by a heating from room temperature up to the temperature of the new peaks obtained in the thermal study. The imaging reveals the relationship between the pre-ordering reaction and the surface aspect presented in the fact of dendrite precipitates. A series of SEM observation have been performed in order to follow the kinetic of the observed precipitates by the way of several series of heating up, from 140 to 220°C for the binary composition and from 100 to 180°C for the ternary composition. Furthermore, this study shows that the silver accelerates the ordering reaction

Synthesis, Characterization and Filtration Properties of Ecofriendly Fe3O4 Nanoparticles Derived from Olive Leaves Extract

Recently, value-added nanomaterials including nanoparticles or nanofluids have been significantly used in designing drilling fluids with tunable rheological properties to meet specific downhole and environmental requirements. In this work, we report novel water-based drilling fluids (WBDF) containing eco-friendly Fe3O4 nanoparticles (Fe3O4-NPs) prepared by using olive leaves extract (OLE) as a reducing and capping agent. A series of economical and excellent performance of WBDF was obtained by introducing low, medium, and high concentrations of Fe3O4-NPs into the conventional WBDF. The synthesis of Fe3O4-NPs was accomplished through the thermal decomposition of iron precursors in an organic medium. NPs were added to the based fluid at concentrations of 0.01, 0.1, and 0.5 wt%. Emission scanning microscopy (FESEM), field- and Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and Energy-dispersive X-ray analysis (EDX) were used for Fe3O4-NPs analysis. Compared to the conventional WBDF, the addition of Fe3O4-NPs as an additive in the based fluids has been investigated to help increasing viscosity and yield point, which is advantageous for hole cleaning, as well as decreasing fluid loss and mud cake thickness

The Discreet charm of the lugubriosie (or The art of tiding oneself over): Thomas Bernhard's Extinction, trans. David McLintock, Penguin Books, London, 1996, pp. 335, RRP $16.95 (paper). [Book Review]

It's all here – the escalating hyperbole, the grandiosity, the connoisseurship, the importuning of the witness – the unmistakeable voice of one of Thomas Bernhard's protagonists holding out, fittingly enough, on the topic of exaggeration. On the occasion of the publication of Bernhard's biography, reviewed recently by Murray Bail in <i>The Age</i>,<a href="http://pandora.nla.gov.au/pan/20741/20020628-0000/www.arts.monash.edu.au/others/colloquy/current/Issue Six/Hanratty.htm#_edn2">[2]</a> I look at his last novel, <i>Extinction</i> and its fine contribution to the sensibility of lugubriousness

In situ X-ray diffraction and the internal friction study of the binary yellow 18-carat gold alloy

Phase transitions in AuCu alloy are investigated using in situ temperature XRD and mechanical spectroscopy. The measurements are carried out from room temperature up to 973 K starting from the ordered phase AuCuI. Using a temperature ramp rate of 1 K/min, the following phase transition sequence was recorded on heating: AuCuI - > AuCuI + AuCuII- > AuCuI + AuCuII + A1 - > AuCuII + A1 - > A1. The mechanical (elastic and anelastic) properties are determined by this phase transition sequence. The mechanical spectroscopy, using a forced torsion pendulum, shows a peak due to antiphase boundary movement in the orthorhombic phase AuCuII according to the temperature dependent internal friction tests. The isothermal frequency measurements show several thermally activated peaks in the phase transitions intervals