This study was carried out on the low-grade chromite, Gedarif state, Sudan, at Umm Saqata- Qala Elnahal to achieve full characterization for the ore via Microscopic studies for the polish section samples, X-ray diffraction analysis (XRD), X-ray Fluorescence Analysis (XRF), Scanning electron microscopic with Energy Dispersive X-ray Spectroscopy (SEM-EDX), and physical properties tests. Microscopic study revealed that the liberation size of chromite mineral is in the range (0.30-0.05) mm. also the X-ray diffraction, X-ray fluorescence and scanning electron microscope with the (...) Energy Dispersive X-ray analysis showed that main gangue of the ore is mineral silicates as Antigorite and contains 21.58-19.60% Cr2O3. The physical tests (saturated density and dry density) demonstrated that ore has low density in range 2.54-2.38 g/cm3 because it is low grade chromite ore, this can be attributed to the dominating mineral silicate (waste) which associated with chromite mineral. (shrink)

The MgAl2O4 spinel doped with Eu2+ ions powder phosphor was prepared at temperature as low as 500 oC using the combustion route. A structural property of the powder was characterized by X-ray diffraction (XRD). This XRD pattern shows the well crystallized cubic phase, Fd-3m space group of MgAl2O4. The estimated average crystalline size is about 36 and 30 nm for MgAl2O4 and Eu doped MgAl2O4 particles respectively. The photoluminescent property of prepared powder was investigated using excitation and emission spectroscopy at (...) room temperatures. Energy levels scheme is proposed for emission from MgAl2O4: Eu2+. (shrink)

Bryophyllum pinnatum is a medicinal plant from the Crassulaceae family. It's traditionally used in Ayurvedic and folk medicine to cure various ailments, and its phytochemicals are used in the reduction of metal ions to produce nanoparticles. This study is aimed at the biosynthesis of nickel oxide nanoparticles using Bryophyllum pinnatum as a reducing, capping, and stabilizing agent, characterizing the synthesized nanoparticles, and studying the anti-microbial activity against Escherichia coli, Staphylococcus aureus, Bacillus subtilis, and Pseudomonas aeruginosa as well as fungi; Candida (...) albicans, and Aspergillus niger. The synthesized nanoparticle was confirmed by UV-VIS, FT-IR, SEM-EDX, and XRD. The UV-VIS indicated the presence of chromophore and a surface plasmon resonance occurring in the sample with a band gap of 4.38 eV. The FT-IR result revealed the stretching vibration of the Ni-O bonds at 715 cm-1. The SEM analysis showed the morphology of the nanoparticles, and the EDX revealed that NiO-NPs are composed of oxygen and nickel elements. The XRD confirmed a face-centered cubic structure with an average size of 16.377 nm. The antimicrobial analysis exhibited the tested minimum concentration against all the bacterial strains. The synthesized Nickel oxide nanoparticles are useful in inhibiting the growth of different types of bacteria. -/- . (shrink)

Abstract: Samples of LaxSr1-xMnO3 (x = 0.5, 0.55, 0.6, 0.66, and 0.7) were prepared by the citrate-nitrate autocombustion method. The prepared nano-particles were investigated and characterized using X-Ray diffraction (XRD) and Transmission Electron Microscopy (TEM) to confirm the formation of the samples in single phase without any impurities and to calculate the particle size. The magnetic susceptibility χM was measured as a function of temperature and magnetic field intensity. From χM(T) and M(H) the saturation magnetization (Ms), remanent magnetization (Mr) and (...) coercivity (Hc) of the samples were estimated. The correlation among physical properties and the ratio of divalent cation substitution was discussed and reported to shed more light on technological applications of the investigated samples. (shrink)