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Solidification and stabilization of coal bottom ash waste (CBA) using CEM1 as the binder have been evaluated in case of leaching as well as the possibility to use this mixture for the construction industry. For this, the CEM1/CBA mass ratio has been varied between 0.5 and 2 and heavy metals leaching of Cu, Cd, Ni and Pb evaluated. Two types of crushed block and whole block leaching tests have been conducted to determine the leaching properties of deionized water, acetic acid and nitric acid leachates. It has been demonstrated that all elements can be immobilized successfully to nearly zero even in the case of a low CEM1 content. Furthermore, it has been shown that more heavy metals leached from the matrix when acetic acid used compared to other leachates. Next to this, the mechanical properties have been tested. After 56 days a compressive strength between 25 and 40 MPa has been measured from 0.5 to 2 CEM1/CBA mass ratios. Based on leaching and compressive strength results, CEM1/CBA mixtures can be considered for the construction industry.

The degradation of polymer insulation is affected by many factors. One of the main factors is surface discharge. In this work, the characteristics of surface discharge on different types of polymer insulation material under different types of electrode shapes were studied. The insulation materials used were high density polyethylene (HDPE), low density polyethylene (LDPE) and polypropylene (PP). Different types of electrode shape used were sharp, flat and sphere electrodes. From the experiments that have been performed, surface discharge characteristics were found to be influenced by the type of insulation material and the electrode shape. Hence, a better understanding on the characteristics of surface discharges may be attained.

The finite element method was employed for the numerical simulation of hetero-junction carbon nanotubes with all possible connection types and their corresponding fundamental homogeneous tubes. Then, atomically defective hetero-junction carbon nanotubes were modeled by introducing silicon impurities and vacant sites into their structures. Finally, the elastic and shear moduli of all the models were evaluated under tensile and torsional loads, based on the assumption of linear-elastic deformation of these nanomaterials. The results showed that armchair and zigzag carbon nanotubes have the highest Young's and shear moduli respectively, among homogeneous carbon nanotubes. The mechanical tests on the hetero-junction carbon nanotubes revealed that these nanotube types have lower moduli when compared to their fundamental tubes. It was clearly observed that armchair–armchair and zigzag–zigzag hetero-junction carbon nanotubes have the highest Young's modulus among the hetero-junction carbon nanotubes while the shear modulus peaks were seen in zigzag-zigzag models. On the other hand, the lowest values for the Young's and shear moduli of hetero-junction carbon nanotubes were obtained for the models with armchair-zigzag kinks. It was also discovered that the atomic defects in the structure of hetero-junction carbon nanotubes lead to a decrease in their Young's and shear moduli which seems to follow a linear trend and could be expressed by a mathematical relation in terms of the amount of the atomic defect in their structures which could be used for the prediction of the tensile and torsional strength of the atomically defective hetero-junction carbon nanotubes for their proper selection and applications in nanoindustry.

Maghemite nanoparticles (γ-Fe 2 O 3 NPs) were synthesized using Massart procedure. The formation reaction were optimized by varying the concentration of ferric nitrate solution (Fe(NO 3 ) 3 ) (0.1, 0.3, 0.5, 0.7 and 1.0 M). All samples were characterized by means of x-ray Diffractometer (XRD), Raman Spectroscopy, Transmission Electron Microscope (TEM) and Alternating Gradient Magnetometer (AGM). The smallest size of the NPs were chosen to be deposited on Silicon (100) substrate by spin coating technique. Annealing process of the samples were performed in Argon ambient at different temperatures (600, 700, 800 and 900°) for 20 min. Metal-oxide-semiconductor capacitors were then fabricated by depositing Aluminium as the gate electrode. The effect of the annealing process on the structural and electrical properties of γ-Fe 2 O 3 NPs thin film were investigated. The structural properties of the deposited thin film were evaluated by XRD analysis, Atomic Force Microscopy (AFM) and Raman Analysis. On the other hand, the electrical properties was conducted by current-voltage analysis. It was revealed that the difference in the annealing temperature affect the grain size, surface roughness, distribution of the nanoparticles as well as the electrical performance of the samples where low annealing temperature (600 °C) gives low leakage current while high annealing temperature (900 °C) gives high electrical breakdown.

Water in oil microemulsion system was used to prepare magnetic iron oxide nanoparticles. Two different volumetric ratios of Fe2+ and OH− (1:1 and 2:1) were investigated. The as-synthesized magnetic iron oxide nanoparticles were characterized by XRD, TEM, TGA and AGM. The XRD, TEM and AGM results showed that crystallize, physical and magnetic sizes of magnetic iron oxide nanoparticles were less than 10 nm which were within the superparamagnetic size range. The magnetization curve also showed no hysterisis loop at room temperature which indicated superparamagnetic behavior. Magnetic iron oxides nanoparticles were also prepared by Massart's procedure. The saturation magnetization of magnetic iron oxides nanoparticles prepared by w/o microemulsion system was higher while the crystallize size was smaller. This showed that magnetic iron oxides nanoparticles could be tailored by different preparation procedures.