Journal des sciences et de l'ingénierie des matériaux

This effect suppresses absorption and increases radiation abilities of larger particles within plasmon mechanism. This is manifested in the corresponding absorption and scatering efficiencies. This creates a simple, yet robust, platform which can be used to investigate the properties of nanoparticles, for sensing, spectroscopy, and optical switching applications. Plasmon resonance related peak, as well as broadening of the plasmon resonance was observed. The efficiency of the photoelectric conversion of gold nanoparticle layers is increased as the intensity of surface plasmon resonance increases.

We report on the structural properties and morphology of the quaternary semiconductor AgIn4GaTe8, prepared by direct fusion of stoichiometric mixture of constituent elements. For this, powder X-Ray Diffractometry (XRD) and Scanning Electron Microscopy (SEM) techniques were employed. From the XRD patterns we have identify a tetragonal phase together with a secondary orthorhombic phase. A strain/size analysis of the full-width-half-maximum (FWHM) of the diffraction lines, showed an anisotropic microstructure associated to the presence of microstrains, induced by crystallite size variations combined with crystallite dislocations. The SEM measurements reveal a material with very rough surface and faceted grains. The grain size determined from SEM micrographs was larger than the crystallite size obtained from the XRD data.

The prepared (Mg1-xCox)2(Ti0.95Sn0.05)O4 (x=0.01~0.009) ceramics are sintered at 1275-1425ºC, the needed sintering temperatures of (Mg1-xCox)2(Ti0.95Sn0.05)O4 ceramics slightly increased with the increase of Co4+ content. The sintering characteristics of (Mg1-xCox)2(Ti0.95Sn0.05)O4 ceramics are developed by the X-ray diffraction patterns and SEM observations to find the influence of sintering temperatures and Sn4+ content on the crystal structure and the grain growth. The influence Co4+ content and sintering temperatures on the quality values (Q×f) and the temperature coefficient of resonant frequency (τf values) of (Mg1-xCox)2(Ti0.95Sn0.05)O4 ceramics at microwave frequency are well developed in this study. As an optimal compose, (Mg1-xCox)2(Ti0.95Sn0.05)O4 (x=0.05) successfully demonstrated a dielectric constant of 14.70, a Q×f of 330,000 GHz and a temperature coefficient of resonent frequency value of -48.18 ppm/oC sintering at 1350ºC.

In this paper, orthotropic materials are selected to be used as a straight bevel gear. These materials have the advantage of being light, are durable in high speeds, require the minimum need for oil, high strengths, and extra loading capacities. Due to these properties, it is highly preferable comparing to conventional materials. This work demonstrates a standard form of the straight bevel gear, to focus on the study of the behaviour of material. Based on the complex proportional assessment method, we selected the woven roving glass fibre as an optimum material to be used in the straight bevel gear model. From the results, it was determined that the composite gear is better in terms of specific energy absorption and dynamic behaviour compared to steel gears. From the results, the jute-epoxy shows a very low value of stiffness and it can be concluded that the natural fibre is not suitable to be used as a material for a straight bevel gear.

This is a review of the existing studies on the Polymer/ clay nano composite used for improving water and moisture barrier in coating. Clays have been and continue to be one of the more important industrial minerals. Research and development activities by clay scientists in academia, government, and industry are continually resulting in new and innovative clay products many of these new applications are the result of improved processing which provides clays of higher purity, more precise particle size and distribution, whiter and brighter color, modified surface chemistry, and other physical and chemical modifications. Some new and improved clay products include tailored or engineered paper coating kaolins, nanocomposites for plastics etc. The use of mineral pigments in coating to provide improved barrier properties has recently gaining increased attention. I described the use of Polymer nano clay for improving the barrier properties of the coated paper studied by several researchers.

The aim of the present work is dilatometric study, within the range from room temperature to 550°C, of two aluminum based sheets containing some alloying elements in different proportions. The level of the Mn concentration in sheet 1 is higher than that in the sheet 2. But, the Fe concentration in the latter sheet is important compared to that of former one. The different proportions of alloying elements could be the origin of the remarkable difference in the thermal expansion behavior of the two studied sheets. It is important to note that both sheets are anisotropic. The thermal expansion coefficient measured along the perpendicular direction to the rolling plane of the sheet 1 containing a considerable amount of Mn, as a function of temperature, is 3.5 times less than that of the sheet 2 containing a considerable amount of Fe. The observed weak thermal expansion coefficient in the case of the sheet 1 is explained by the strengthening of the interatomic bonds and the interaction forces. The use of complementary techniques of investigations such as Transmission electron Microscopy (TEM), scanning electron microscopy (SEM) and energy dispersive (EDS) chemical analysis reveal the presence of thermally stable particles, especially, in sheet 1.

An investigation was conducted to determine the effect of the ball diameter sizes on milling operation. A laboratory size ball mill was used with ball media of sizes 10 mm, 20 mm and 30 mm respectively. Quartz was the material used to perform the experiment and was arranged into 3 mono-sizes namely -8 mm +5.6 mm, -4 mm +2.8 mm and-2 mm +1.4 mm for the experiment. A mill run having a mixture of the 3 ball diameter sizes was also conducted. It was determined that the 30 mm diameter balls were most effective of the three sizes during the grinding of the 3 monosize feed material samples. The 10 mm diameter balls were the least effective as minimum particle breakage was observed whereas the 20 mm diameter balls were relatively effective to some extent. The selection function of the 30mm balls was also much greater as it had a higher maximum point and a very low small abnormal region. The mill run conducted using a mixture of ball sizes however was slightly better than that of the 30 mm diameter balls. The primary breakage function was observed as to be non-related to the ball diameter but rather to the 3 mono-sizes of the feed material. In terms of the power draw, there seemed to be no link between it and the ball diameter size.

The corrosion inhibition property of 6-diallylamino-1,3,5-triazine-2,4-dithiol monosodium (DAN) for aluminum alloy corrosion in hydrochloric acid solution was investigated by weight loss, potentiodynamic polarization, cyclic voltammetry and scanning electron microscopy (SEM). The effect of DAN concentration, temperature, immersion time and acidic concentration and was studied. It was found that DAN presented excellent corrosion inhibition performance for aluminum alloy. Polarization curves revealed that DAN acted as the cathodic inhibitor. The inhibition efficiency was improved with the concentration of DAN inhibitor, while decreased with the improvement of corrosion temperature and immersion time. The adsorption isotherm of DAN inhibitor on aluminum alloy surface conformed to langmuir adsorption model and the value of ΔGθ inferred the interaction of DAN inhibitor with aluminum as chemical adsorption at 40°C