Nanoparticles of Mn0.5Zn0.5-xCdxFe2O4 with x varying from x=0.0 to 0.3 were prepared by wet chemical co-precipitation method. The structural and magnetic properties were studied by using X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM), Transmission Electron Microscopy (TEM) and Electron Paramagnetic Resonance (EPR) technique. The lattice constant increases with increase in Cd content. This increase in the lattice constant is due to larger ionic radii of the Cd2+ (0.97 Ao) ions as compared to Fe3+ (0.64 Ao) ions. The intensities of the planes (220) and (440), increases with increasing Cd2+ion concentration. This shows that Cd2+ ions occupy tetrahedral A sites and octahedral B sites in the nano dimension against their chemical preference for A site. The line width (DHpp) and the g value of the Electron paramagnetic resonance (EPR) signal decreases with increase in the Cd content. The magnetic moment of all the samples up to x=0.2 calculated from EPR studies are lower when compared to the theoretical values. This lower value of magnetic moment confirms the existence of non collinear magnetic structure arising due to significant amount of spin disorder existing at B site.

In this study, based on Density Functional Theory (DFT), the effect of solution on the g-tensor, the hyperfine coupling constant of atoms and finally, the EPR spectrum of alanine free radicals induced by ionizing radiation such as electron and gamma was investigated by applying implicit models such as COSMOand explicit models such as introduction of hydrogen bonds to the cluster structures. The results indicated that there was a good consistency between the g-tensor and hyperfine coupling constant of atoms and the experimental data in the solution; also, there was also qualitative consistency in the crystal by the introduction of the hydrogen bond of the water molecule to the cluster models. The use of different clusters in the formation of hydrogen bonds of water molecule with radicals showed that in the first shell, four, seven and six water molecules were required for R1, R2 and R3 radicals, respectively. Finally, the effect of solution on the EPR spectrum was predicted without changing the radical nature.

In recent years the rupture of landfill centers has resulted in the importance of studying the behavior of municipal solid waste (MSW). MSW as the main constituent element in landfills has a complicated performance. In this study, by using the results of large – scale direct shear experiments with dimensions of 300 mm x 300 mm x 150 mm, 2 models to predict the behavior of MSW with ages of fresh and 3 months are presented. The purpose of this investigation is to predict MSW stress-strain behavior for kahrizak landfill as a sample of developing countries landfills under aging and by structural models. These models are Hyperbolic model and Evolutionary polynomial regression (EPR). In these collection of experiments, aging process up to 3 months, was artificially applied to samples. Three normal stresses 20, 50, 100 kpa and three shear strain rates 0. 8, 8, 19 mm per minute were used for samples with different ages. The results of these two models, in addition to predict MSW behavior under aging and degradation, shows high accordance with experimental results by direct shear apparatus. Finally this study states the advantage of EPR model relative to Hyperbolic model in higher accuracy for all experiments.