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)

Abstract: Modern PET/CT clinics consist of a scanner room housing PET/CT unit and a control area, two or more waiting rooms where patients rest prior to scanning, and a hot lab where doses are prepared. The 511 keV photons from the PET positron emitting isotopes are the source term for the waiting rooms and the hot lab, while both the 511 keV photons and the polyenergtic spectrum of x-rays from the CT unit must be considered in the scanning roomThis study is intended to estimate dose distribution resulting from using a FDG procedure (555 MBq). The dose distribution is evaluated in injection room, waiting room, and scanning room using two methods. The first method is the analytical method whids is based on AAPM report № 108, while in the second method the dose distribution was simulated using the Monte Carlo code EGSXYZnrc .In the Monte Carlo method some parameters such as the optimal number of histories and the cut off energy of the electron are found to have a significant effect on the results. These parameters are tested and those values with less statistical error are adapted for the calculations.A good agreement between the two methods has been achieved. The dose distribution in the uptake room , waitting room and the scanning room appears to be below the annually dose limit and does not exceed 1% at the adjacent areas.
مريومة البهلول القرقني (2009)

Cardiovascular disease (CVD) is a major cause of mortality and the main cause of morbidity worldwide. CVD may lead to heart attacks and strokes and most of these are caused by atherosclerosis; this is a medical condition in which the arteries become narrowed and hardened due to an excessive build-up of plaque on the inner artery wall. Arterial calcification and, in particular, abdominal aortic calcification (AAC) is a manifestation of atherosclerosis and a prognostic indicator of CVD. In this paper, a two-stage automatic method to detect and quantify the severity of AAC is described; it is based on the analysis of lateral vertebral fracture assessment (VFA) images. These images were obtained on a dual energy x-ray absorptiometry (DXA) scanner used in single energy mode. First, an active appearance model was used to segment the lumbar vertebrae L1-L4 and the aorta on VFA images; the segmentation of the aorta was based on its position with respect to the vertebrae. In the second stage, feature vectors representing calcified regions in the aorta were extracted to quantify the severity of AAC. The presence and severity of AAC was also determined using an established visual scoring system (AC24). The abdominal aorta was divided into four parts immediately anterior to each vertebra, and the severity of calcification in the anterior and posterior walls was graded separately for each part on a 0-3 scale. The results were summed to give a composite severity score ranging from 0 to 24. This severity score was classified as follows: mild AAC (score 0-4), moderate AAC (score 5-12) and severe AAC (score 12-24). Two classification algorithms (k-nearest neighbour and support vector machine) were trained and tested to assign the automatically extracted feature vectors into the three classes. There was good agreement between the automatic and visual AC24 methods and the accuracy of the automated technique relative to visual classification indicated that it is capable of identifying and quantifying AAC over a range of severity. arabic 30 English 163
Karima Mohamed Ali Elmasri, William Evans, Yulia Hicks(1-2016)