Some of publications in Department of Nuclear Engineering
A Comparative Study Using Monte Carlo Codes for the Simulation of Photons Emitted by the Elekta Sl-25 Linear Accelerator at the Tripoli Medical Center
Abstract: A 6MV and 15MV electron beams produced by the Elekta precise SL-25 linear accelerator at the Tripoli Medical Center (TMC) were modeled using the MCNP-4C code. Firstly the photon beam energies are tuned by comparison to experimental results previously performed at the TMC. Only the beam energy of the 6MV is modified to 6.2MV. Secondly the percent depth dose curves and beam profiles are calculated for the two energies in different field sizes in the water phantom. Matching with experiment is within an acceptable published allowance of 2%. The distances at which the maximum depth dose in the water phantom is reached are calculated as (1.5cm -1.7cm) for the 6.2MV setting and (2.7cm-3cm) for the 15MVsetting. خديجة عمر بن ابراهيم (2011)
Studying of Naturally Occurring Radioactive Materials (NORM) in Oilfield (A/100) South East of Libya
The huge volume of Naturally Occurring Radioactive Materials (NORM) wastes produced annually by the oil and gas industry in Libya deserves the attention of the national environmental protection authority, radioactive waste management and regulatory bodies. An investigation was carried out to find out the concentration of (NORMs) in evaporation ponds sludge in south eastern oilfield (A/100) of Libya. Twenty soil samples were collected from five evaporation ponds sludge. Activity concentrations of 226Ra, 232Th and 40K in soil generated during oil production operations were determined using a gamma spectroscopy system based on High Purity Germanium (HPGe) detector. Concentrations ranged from 83 to 1000 Bq kg–1 for 226Ra, 59 to 315 Bq kg–1 for 232Th and 109 to 304 Bq kg–1 for 40K. To evaluate the radiological effects, radium equivalent activity and external hazard are calculated. The magnitude of these results demonstrates the need of screening oil residues for their radionuclide content in order to decide about possibility of minimize the environmental impact of NORM and their final disposal. Disposal of NORM waste has to be in accordance with national regulations, environmental policy and international agreements and conventions. The researchers recommend limits for clearance and disposal, based on best international practice.
arabic 18 English 82 Usama Elghawi (1-2021)
A robust technique for detecting abdominal aortic calcification using dual energy x-ray absorptiometry
BACKGROUND: Abdominal aortic calcification (AAC) is a marker of atherosclerosis and a predictor of subsequent vascular disease. To date, there has been little research into the automatic detection and quantification of AAC. METHODS: In this study, lateral dual energy X-ray absorptiometry (DXA) scans are used to detect AAC; this is possible because of the anatomical position of the abdominal aorta anterior to the lumbar spine. The deformable shape modelling techniques active shape (ASM) and active appearance (AAM) models are used to model the calcified aorta and four vertebrae of the lumbar spine L1-L4. RESULTS: ASM and AAM were trained and tested on 14 DXA images. The shape of both calcified aorta and four lumbar vertebrae were extracted automatically from the DXA scans using combined shape and appearance models. CONCLUSION: ASM and AAM were implemented successfully. The calcified aorta obtained from the DXA scans was segmented using this modelling technique. The next step is to develop a new automated method to quantify the calcification within the aorta. arabic 13 English 89 Karima Elmasri(6-2015)