Silver-calcium-borates as better replacement for conventional organic antimicrobials in cosmetic products

Microbes generally develop resistance towards organic antibacterial agents like ampicillin, Sulfonamides, methicillin, etc., and progressively new drugs are being invented to replace them. Hence, replacement of organic antibacterial agents with inorganic analogues requires constant research and the present investigation reports alternatives for conventional antimicrobial agents like methylparaben, diazolidinyl urea, etc., in the cosmetic products with silver incorporated calcium borates. The chemically synthesized silver-calcium borates have been analyzed for phase purity using powder XRD analysis, nature of bonding using FTIR vibrations, and morphology using SEM. The antibacterial and antifungal studies were carried out for the novel inorganic silver-calcium borates incorporated cosmetic products. The products were also subjected to thermal & photostability studies and found to be comparable with that of commercially available products. A minimum quantity of 3 ppm of silver-calcium borate concentration was required to bring about nearly 100% bacterial reduction in the cosmetic products.

Evaluating and Enhancing Iron Removal via Filterable Iron Precipitates Formation during Coal-Waste Bioleaching

Iron removal via jarosite precipitate formation is a commonly used technique in various hydrometallurgical processes. Excess iron removal often becomes essential to an overall metal recovery circuit. This is particularly important to processes involving iron-bearing minerals. A technique, which involved the use of pyrite to generate acid for leaching, for iron removal is critical to enabling the process. Iron removal using CaO or similar reagents is expensive and often results in lost product. In the present study, various compounds that facilitate jarosite formation, namely Na2SO4, NH4OH, KCl, and KOH, were utilized and their effect in precipitation was observed. Visual Minteq assisted simulations were run in order to evaluate favorable conditions for iron removal. Morphology and elemental composition of precipitates were analyzed using scanning electron microscopy equipped with energy-dispersive X-ray spectroscopy, and the phase purity was identified using X-ray diffraction analysis.

Analisis Pertumbuhan Fase Superkonduktor BSCCO-2212 dan BPSCCO-2212 Akibat Variasi Suhu Sintering Menggunakan Metode Pencampuran Basah

The research was conducted to determine the effect of sintering temperature on the level of purity of the superconducting phase BSCCO-2212 and BPSCCO-2212 using the wet mixing method. Sintering was carried out for 20 hours with variations in sintering temperature: 825, 830, 835 and 840°C. XRD results showed that the phase purity level increased until it reached the optimum point at 835°C sintering temperature and then decreased at 840°C. The highest volume fraction of the BSCCO-2212 sample was obtained at a sintering temperature of 835°C at 71.09% and the highest degree of orientation was obtained at a sintering temperature of 830°C at 26.44%. In the BPSCCO-2212 sample, the highest volume fraction was obtained at a sintering temperature of 835°C at 52.59% and the highest degree of orientation at a sintering temperature of 830°C at 43.49%. The results of the comparison of BSCCO-2212 and BPSCCO-2212 samples showed that the BPSCCO-2212 sample had a higher level of phase purity than BSCCO-2212.

Properties of Spark Plasma Sintered Compacts and Magnetron Sputtered Coatings Made from Cr, Mo, Re and Zr Alloyed Tungsten Diboride

To enhance the properties of tungsten diboride, we have synthesized and characterized solid solutions of this material with chromium, molybdenum, rhenium and zirconium. The obtained materials were subsequently deposited as coatings. Various concentrations of these transition metal elements, ranging from 0.0 to 24.0 at.%, on a metals basis, were made. Spark plasma sintering was used to synthesize these refractory compounds from the pure elements. Elemental and phase purity of both samples (sintered compacts and coatings) were examined using energy dispersive X-ray spectroscopy and X-ray diffraction. Microindentation was utilized to measure the Vickers hardness. X-ray diffraction results indicate that the solubility limit is below 8 at.% for Mo, Re and Zr and below 16 at.% for Cr. Above this limit both diborides (W,TM)B2 are created. Addition of transition metals caused decrease of density and increase of hardness and electrical conductivity of sintered compacts. Deposited coatings W1−xTMxBy (TM = Cr, Mo, Re, Zr; x = 0.2; y = 1.7–2) are homogenous, smooth and hard. The maximal hardness was measured for W-Cr-B films and under the load of 10 g was 50.4 ± 4.7 GPa. Deposited films possess relatively high fracture toughness and for WB2 coatings alloyed with zirconium it is K1c = 2.11 MPa m1/2.