Saeideh Ebrahimiasl, Ali Noori, Azmi Zakria,
Volume 13, Issue 2 (12-2019)
Abstract
Since Amaranth (AM) is one of the dye compounds which is harmful to human’s life its removal from industrial waste water would reduce their environmental impact and health effect. Copper nanoparticle (CuNP) is a simple and eco-friendly material which can be used to remove this pollutant. In this paper, copper nanoparticles were synthesized, for removal of AM dye. The experiments were designed by response surface methodology with a modified cubic model to predict the variables. To investigate variables and interaction between them analysis of variance was used with high F-value (1.44), low P-value (<0.0409), non-significant lack of fit, the determination coefficient of 0.898 and the adequate precision of 7.25. Experimental and predicted values of the response illustrated a good correlation. The optimum parameters catalyst amount (0.14 w/w%), initial concentration (7.38 mg/l), reaction time (47.75 s) and pH (2.83) for the highest removal percentage of (96.10%) was attained.
Zahra Danesh Kaftroudi,
Volume 15, Issue 1 (1-2021)
Abstract
In this work, for the first time, the improved lasing performance of a blue GaN-based laser diode is demonstrated by the introduction and vertical optimization of a new quadruple asymmetric waveguide structure. In the new proposed waveguide structure, in the first step, p-waveguide and electron blocking layers have been omitted. Then a triple asymmetry was considered for the design of an AlGaNp-cladding layer inside the waveguide structure. The performances of the conventional and proposed laser structures were theoretically studied using the photonic integrated circuit simulator in 3D simulation software. The 3deminsional simulations of carrier transport, optical wave- guiding and self-heating were combined self-consistently in the software. A good agreement was achieved between simulations and experiments by careful choice of different material parameters in the physical models. The effects of the AlGaN p-cladding layer properties on the performance of the new quadruple asymmetric waveguide GaN-based laser were theoretically studied. Threshold current, output power, and operation voltage were compared for different composition of Al, doping, and thickness of the AlGaN p-cladding layer. According to the simulation results, the optimized values of Al composition, doping, and thickness of the AlGaN p-cladding layer obtained for high-power performance.
