Monitoring of the Physical and Chemical Properties of a Gasoline Engine Oil during Its Usage

Physicochemical properties of a mineral-based gasoline engine oil have been monitored at 0, 500, 1000, 2000, 3500, 6000, 8500, and 11500 kilometer of operation. Tracing has been performed by inductively coupled plasma and some other techniques. At each series of measurements, the concentrations of twenty four elements as well as physical properties such as: viscosity at 40 and 100°C; viscosity index; flash point; pour point; specific gravity; color; total acid and base numbers; water content have been determined. The results are indicative of the decreasing trend in concentration of additive elements and increasing in concentration for wear elements. Different trends have been observed for various physical properties. The possible reasons for variations in physical and chemical properties have been discussed

Copper oxide nanoparticles-loaded zeolite and its characteristics and antibacterial activities

In the present work, a simple and green co-precipitation method was used to prepare copper oxide-zeolite nanocomposites (CuO-zeolite NCs). The weight ratio (1, 3, 5, 8 and 10 wt%) of CuO nanoparticles (NPs) loaded into zeolite was investigated to obtain the optimum CuO distribution for antibacterial activities. The prepared CuO-zeolite NCs were characterized by ultraviolet-visible (UV–vis) spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, powder X-ray diffraction (XRD), and energy dispersive X-ray fluorescence spectrometry (EDXRF). The transmission electron microscopy (TEM) and field emission scanning electron microscopy (FE-SEM) revealed a uniform surface morphology of the CuO-zeolite NCs. The UV–vis spectrum of NCs showed absorption peaks between 230 and 280 nm for nano-CuO in the XRD patterns, and new peaks appeared between (36.56°–38.83°) related to the CuO. At weight ratio less than 10 wt%, the CuO nanoparticles loaded to the zeolite exhibited spherical shapes with average particle diameter of 6.5 nm measured by TEM and XRD. Antibacterial activities were tested against Gram-negative and Gram-positive bacteria. The obtained results showed that, CuO-zeolite NCs with 8 wt% CuO nanoparticles had the highest antibacterial activities against Bacillus Subtilis B29 and Salmonella Choleraesuis ATCC 10708, which can be attributed to the good dispersion of CuO NPs on the zeolite surface

Electrochemical Oxidation of Cysteine at a Film Gold Modified Carbon Fiber Microelectrode Its Application in a Flow—Through Voltammetric Sensor

A flow-electrolytical cell containing a strand of micro Au modified carbon fiber electrodes (CFE) has been designedand characterized for use in a voltammatric detector for detecting cysteine using high-performance liquid chromatography. Cysteine is more efficiently electrochemical oxidized on a Au /CFE than a bare gold and carbon fiber electrode. The possible reaction mechanism of the oxidation process is described from the relations to scan rate, peak potentials and currents. For the pulse mode, and measurements with suitable experimental parameters, a linear concentration from 0.5 to 5.0 mg·L−1 was found. The limit of quantification for cysteine was below 60 ng·mL−1

Triangular and prism-shaped gold-zinc oxide plasmonic nanostructures: in situ reduction, assembly and full-range photocatalytic performance

Gold-based nanocatalysts have been traditionally selected for multiple homogeneous and heterogeneous reactions of interest involving redox processes. Likewise, greener routes involving more efficient reactors and the use of inexpensive and nature-mimicking excitation sources have boosted the research on photocatalysts able to drive these chemical reactions upon excitation with multiple wavelength sources beyond the UV range. In the present work we report on a multi-step synthesis approach that implies the in situ generation of triangular and prism-shaped gold nanostructures with a localized surface plasmon resonance effect and their direct assembly onto a ZnO nanostructured semiconductor support. Different LED excitation sources in the whole UV-Vis-NIR range have been systematically selected to activate these hybrid materials in the selective reduction of p-nitrophenol (4-NP), a wellknown contaminant by-product. While ZnO becomes preferentially active in the UV window, the anisotropic shape of these gold plasmonic nanostructures helps to broaden the photocatalytic response of ZnO towards the visible and NIR range, being especially active under 460 nm blue light irradiation and expanding their potential application in multiple solar-driven catalytic processes of interest for decontamination and upgrading of toxic chemicals

Heterogeneous Photodecolorization of Methyl Green Catalyzed by Fe(II)-o-Phenanthroline/Zeolite Y Nanocluster

The potential of Fe(II)-orthophenatrolin, as doped with synthetic zeolite Y nanocluster (Na-Y) via complexation process, after wet impregnation of parent zeolite with FeSO4 aqueous solution, was studied as a photocatalyst in decolorization of Methyl Green (MG) under UV irradiation. The characterization of the synthesized zeolite nanocluster and the prepared catalyst was studied using X-ray powder diffraction (XRD), infrared spectroscopy (FT-IR), thermal analysis, and SEM methods. The dye photodecolorization process was studied considering the influence of experimental parameters and it was observed that photoreactivity of the photocatalyst was varied with catalyst amount, initial dye concentration, pH of dye solution, temperature, and the presence of KBrO3. The optimal experimental parameters were obtained as follows: catalyst amount: 1 gL−1, dye concentration: 40 ppm, pH: 9, and active component value: 100 mg Fe(II)-orthophenatrolin per g catalyst. The reusability of the intended catalyst was also investigated. The degradation process obeyed first-order kinetics