One of the most recognized and widely used treatment modality in cancer is radiation therapy which depends on the radiosensitivity of tumour tissue. Over the past few years there has been lot of interest in the use of formulations to enhance radiotherapeutic effects, especially using metallic (mainly gold) based nanoparticles. Our goal here is to fabricate nanoparticles (NPs) that can be delivered to tumor tissue to increase its radiosensitivity. This would increase efficiency of radiation absorption by the tumor tissue and reduce radiation doses delivered during radiotherapy. This could potentially decrease radiation exposure related side effects to patients. We have achieved this by synthesizing nanoparticles of high Z elements such as gold, silver and a more efficient bimetallic silver-gold size ranging from 3nm to 72nm using chemical reduction and hydrothermal method. The synthesized metallic nanoparticles were characterised using Ultraviolet (UV)-Visible Spectroscopy, Fluorescence spectroscopy and Dynamic Light Scattering. The metallic nanoparticles showed radiosensitizing activity in colloidal form by absorbing radiations when irradiated by 60 Co source which emits two gamma rays of energy 1173keV and 1332keV. Based on our results, we are of the opinion that such radio-sensitizing agent if injected into the tumour tissue would increase radiation absorption and enhance treatment effect with lower therapeutic radiation dosage.

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A peak in the temperature profile has always been observed at the loading end of an air-cooled resistive heating diffusion furnace and it seems to be an inherent character of such furnaces. The shape of this peak under different setting conditions and its effect on t h e diffusion of impurities such as phosphorus and aluminium into silicon wafers for solar cell fabrication has been investigated. A difference upto 26 mV in the open circuit voltage has been observed because of this peak in the temperature profile.

The effects of gamma irradiation on hydrothermally synthesized BaTiO 3 nanoparticles have been investigated. Gamma irradiation is carried out at room temperature from 0, 50, 100, 150, 200 kGy to maximum dosage up to 250 kGy with 60 Co source. Prepared BaTiO 3 nanoparticles are investigated using line profile analysis employing X-ray diffraction (XRD) data; the structure, size, dielectric and conductivity properties of the BaTiO 3 are studied using Raman spectroscopy, transmission electron microscopy (TEM), and impedance analyzer. The post-irradiation volume of the BaTiO 3 unit cell increases with dosage and most of the cells possess a modified tetragonal structure. The Grüneisen constant is high for 242 cm À1 optical modes with 150 kGy and lowest for 516 cm À1 optical mode for 50 kGy irradiation. The morphology changes and particle size decreases as the radiation dose is increased. Conductivity (σ) increases with the increase in radiation dose, especially at 50 kGy. Cole-Cole plot is suggestive of the depolarization nature of irradiated BaTiO 3 nanoparticles.