The performance of a persistent phosphor is often determined by comparing luminance decay curves, expressed in cd/m 2 . However, these photometric units do not enable a straightforward, objective comparison between different phosphors in terms of the total number of emitted photons, as these units are dependent on the emission spectrum of the phosphor. This may lead to incorrect conclusions reg...

Trivalent lanthanide (Eu(3+), Tb(3+) and Dy(3+)) ions activated tunable color emitting BaGd2O4 (BG) phosphors were synthesized by a facile Pechini-type sol-gel process. The X-ray diffraction pattern confirmed the orthorhombic phase after annealing at 1300 °C for 5 h. Morphological studies were performed based on the analysis of transmission electron microscopy images, which showed needle type n...

This study investigates removing ash and pyrite sulphur from bitumen by column flotation process. Central composite design (CCD) of response surface methodology (RSM) was applied for modeling and optimization of the percentage of ash and pyrite sulphur removal from bitumen. The effects of five parameters namely the amounts of collector and frother agents, particle size, wash water rate and feed...

Arthrobacter viscosus biomass was used for Cr(VI) biosorption. The effect of pH on Cr(VI) reduction and removal from aqueous solution was studied in the range of 1-4. The Cr(VI) removal involves both redox reaction and adsorption of metal ions on biomass surface. The removal rate of Cr(VI) was enhanced by very acid conditions, while higher solution pH values favored the removal of total chromiu...

The aim of the chapter is to introduce a new technology using the flow-divided electrodes for sewage reclamation based on redox and concentrating ions. This creative system can be used directly for sewage treatment without the need for costly ion-exchange membranes and other chemical reagents. Under experimental condi‐ tions, the removal percentage of TDS (total dissolved salts) is 83 %and the ...

Introduction: The most important environmental problem of automotive industries is the produced wastewater due to its various processes. The flocculation and coagulation along with chemical sequestration are among important processes for removing contaminants from wastewaters. The aim of this study is to investigate the efficiency of coagulation and flocculation process along with chemical sequ...

The Ba2P2O7:Tb , Eu phosphors were synthesized by a high temperature solid-state reaction method in air atmosphere and their crystal structures, lifetime, luminescence properties, and energy transfer mechanism were investigated in detail. A series of characteristic emissions of Ba2P2O7:Tb , Eu phosphors were observed in the emission spectra at around 545 nm, 593 nm, and 613 nm when excited at 3...

Sr(NO3)2, Al(NO3)3, NH2CONH2, Eu2O3 and Dy2O3 are used as the raw materials for the preparation of SrAl2O4 (RE: Eu, Dy) precursor by the combustion synthesis technique (CST), which is widely known to prepare nano sized phosphors. The influence of varied concentration of Dy on crystal structure and optical properties is analyzed by means of Xray diffraction (XRD), scanning electron microscopy (S...