Sudan Atomic Energy Commission

Khartoum, Sudan

Sudan Atomic Energy Commission

Khartoum, Sudan
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Rushdi M.A.H.,Sudan Atomic Energy Commission | Rushdi M.A.H.,National Center for Radiation Research And Technology | Abdel-Fattah A.A.,National Center for Radiation Research And Technology | Soliman Y.S.,National Center for Radiation Research And Technology
Radiation Physics and Chemistry | Year: 2017

The radiation-induced defects in strontium carbonate (SrCO3) rod dosimeter in the dose range of 2.5 Gy–25 kGy was investigated using electron paramagnetic resonance (EPR) technique. The EPR spectra of γ-irradiated strontium carbonate (SC) rods exhibit a strong EPR signal with the spectroscopic splitting g-factor 2.008 and a weak signal at g-factor 2.003. This signal increases with increasing irradiation dose. The dose-response function has a good linearity in the low dose range of 2.5–500 Gy and slight sub-linearity in the high dose range of 0.5–25 kGy. The dosimeter is nearly humidity independent in the level of 33–77% relative humidity during irradiation. The temperature coefficient of the dose-response function is 0.22% per °C in the temperature range of 20–40 °C. The rod dosimeter exhibits a maximum deviation from water equivalency by 7% in the energy range of 0.3–5 MeV. The overall uncertainty of dose determination using SC dosimeter is 5.2% and 4.54% (2σ) for low and high dose range, respectively. © 2016 Elsevier Ltd

Rehani M.M.,International Atomic Energy Agency | Applegate K.,Emory Radiology | Ahmed N.A.,Sudan Atomic Energy Commission | Al-Dhuhli H.,Sultan Qaboos University | Al-Naemi H.M.,Hamad Medical Corporation
European Radiology | Year: 2013

Objective: To survey procedures and protocols in paediatric computed tomography (CT) in 40 less resourced countries. Methods: Under a project of the International Atomic Energy Agency, 146 CT facilities in 40 countries of Africa, Asia, Europe and Latin America responded to an electronic survey of CT technology, exposure parameters, CT protocols and doses. Results: Modern MDCT systems are available in 77% of the facilities surveyed with dedicated paediatric CT protocols available in 94%. However, protocols for some age groups were unavailable in around 50% of the facilities surveyed. Indication-based protocols were used in 57% of facilities. Estimates of radiation dose using CTDI or DLP from standard CT protocols demonstrated wide variation up to a factor of 100. CTDIvol values for the head and chest were between two and five times those for an adult at some sites. Sedation and use of shielding were frequently reported; immobilisation was not. Records of exposure factors were kept at 49% of sites. Conclusion: There is significant potential for improvement in CT practice and protocol use for children in less resourced countries. Dose estimates for young children varied widely. This survey provides critical baseline data for ongoing quality improvement efforts by the IAEA. Key Points: • Paediatric computed tomography (CT) practice was audited in 40 less resourced countries. • This audit revealed widespread (up to 100 times) variation in radiation dose. • Specific CT protocols for certain age groups were frequently (ca. 50%) unavailable. • This survey demonstrates significant potential for improvement in paediatric CT practice. • Multinational networking is an effective mechanism for quality improvement. © European Society of Radiology 2012.

Medani A.M.M.H.,Sudan Atomic Energy Commission | Medani A.M.M.H.,Al Farabi College | Elnour A.A.,University of Dammam | Saeed A.M.,University of Khartoum
Public Health Nutrition | Year: 2013

Objective To study the associations between intakes of iodine and water chemicals and the thyroid gland status of schoolchildren living in the coastal city of Port Sudan. Design In our previous nationwide study on goitre, it was observed that the prevalence of goitre was high in Port Sudan city despite high urinary iodine excretion. A cross-sectional study including schoolchildren aged 6-12 years was designed. Measurements determined the prevalence of goitre, urinary iodine concentration and thiocyanate secretion in casual urine samples, serum levels of thyroxine, triiodothyronine, thyroid-stimulating hormone and thyroglobulin, as well as the levels of Cl-, F-, Ca 2+, Mg2+ and total hardness of drinking water. Subjects Schoolchildren (n 654) aged 6-12 years. Setting Port Sudan city is located at the western bank of the Red Sea. The city is surrounded by a mountainous area known as the Red Sea Hills. It is the main sea port in the Sudan, inhabited by ethnically and socio-economically heterogeneous populations. Results The prevalence of goitre in Port Sudan was 34·86 % while the median urinary iodine concentration was 46·4 μg/dl. Out of thirty-one pupils from Port Sudan, twenty-four (77·42 %) were found to have urinary iodine concentration greater than 30 μg/dl and twelve (38·71 %) had different degrees of biochemical hypothyroidism. Excessive concentrations of Cl -, Ca2+, Mg2+ and water hardness (369·2, 116·48, 60·21 and 539·0 mg/l, respectively) were detected in drinking water samples collected from Port Sudan that exceeded levels permitted by the WHO. Conclusions The coastal city of Port Sudan is a goitre-endemic area. In contrast to other Sudanese cities in which endemic goitre is related to iodine deficiency, goitre in Port Sudan is associated with iodine excess. Water chemicals seemed to have no effects on thyroid status. Copyright © The Authors 2012.

Idris A.M.,King Khalid University | Naheid S.A.,Sudan Academy of Sciences | Elgorashe R.E.E.,King Faisal University | Eltayeb M.A.H.,Sudan Atomic Energy Commission | Alnajjar A.O.,King Faisal University
Analytical Methods | Year: 2012

Recently, a more efficient sequential injection chromatograph (SIC) with a high pressure selection valve has been developed at our laboratory. In the current work, the newly developed SIC system was exploited to optimize and validate a new method for the separation and quantification of lisinopril and hydrochlorothiazide in pharmaceutical preparations. A multi-response optimization study was conducted to screen the effect of mobile phase composition on resolution, reagent consumption, retention time, peak symmetry, peak height and baseline. The factorial design approach was adopted and the effect factors were determined. The SIC method has proven to be a competitor to high performance liquid chromatographic methods with respect to sample frequency, reagent consumption and safety for the environment, besides instrumentation benefits with respect to inexpensiveness, simplicity and portability. Short C 18 monolithic columns (30 × 4.6 mm) were used to offer a rapid and reagent-saving procedure. Miniaturized fiber optic spectrometric devices were coupled with the SIC system to provide more instrumentation portability. Satisfactory separation, peak symmetry and theoretical plates were achieved. The SIC method was also accurate (the recovery range was 98.8-101.8%), precise (the RSD range was 0.95-2.29) and sensitive (the limits of detection were below 1.5 μg mL -1). © 2012 The Royal Society of Chemistry.

Mohammed M.E.A.,King Khalid University | Mohammed M.E.A.,Sudan Atomic Energy Commission
Chemistry | Year: 2015

One of the major duties of any lecturer is to adopt different teaching methods in order to obtain excellent student performance. This study was conducted to investigate the performance of students in a seminar based examination compared to a lecture and practical sessions based examination. The basic course of biochemistry, taught to 35 students of chemistry and biology of the faculty of science at King Khalid University, was conducted following three teaching methods; lectures, practical sessions and seminar based teaching. Vitamins were taught through seminars prepared and presented by the students while the amino acids, protein and enzymes course was delivered through lectures and practical sessions. The final exam of the course included questions testing the knowledge of the students concerning the seminar and lecture based information. Regarding the results of the seminar based questions; 15 (42.9%) passed the exam and the range of the marks was (25- 90) while the students who passed the lecture and practical sessions based questions were 17 (48.6%) and the range of the marks was (35- 80). However, the pass mark was 60%. Although the highest marks were scored in the seminar based questions, the general performance of the students in the seminar based questions was poor compared to the lecture and practical sessions based questions.

Reece S.E.,University of Edinburgh | Ali E.,Sudan Atomic Energy Commission | Ali E.,University of Khartoum | Schneider P.,University of Edinburgh | And 2 more authors.
Proceedings of the Royal Society B: Biological Sciences | Year: 2010

Life-history theory predicts that sexually reproducing organisms have evolved to resolve resourceallocation trade-offs between growth/survival versus reproduction, and current versus future reproduction. Malaria parasites replicate asexually in their vertebrate hosts, but must reproduce sexually to infect vectors and be transmitted to new hosts. As different specialized stages are required for these functions, the division of resources between these life-history components is a fundamental evolutionary problem. Here, we test how drug-sensitive and drug-resistant isolates of the human malaria parasite Plasmodium falciparum resolve the trade-off between in-host replication and between-host transmission when exposed to treatment with anti-malarial drugs. Previous studies have shown that parasites increase their investment in sexual stages when exposed to stressful conditions, such as drugs. However, we demonstrate that sensitive parasites facultatively decrease their investment in sexual stages when exposed to drugs. In contrast to previous studies, we tested parasites from a region where treatment with antimalarial drugs is common and transmission is seasonal. We hypothesize that when exposed to drugs, parasites invest in their survival and future transmission by diverting resources from reproduction to replication. Furthermore, as drug-resistant parasites did not adjust their investment when exposed to drugs, we suggest that parasites respond to changes in their proliferation (state) rather the presence of drugs. © 2010 The Royal Society.

Medani A.M.M.H.,Sudan Atomic Energy Commission | Elnour A.A.,University of Dammam | Saeed A.M.,University of Khartoum
Bulletin of the World Health Organization | Year: 2011

Objective To describe the status of iodine deficiency disorders (IDDs) in the Sudan more than 25 years after the initiation of IDD control programmes and to explore the causes of endemic goitre in the country. Methods Testing for IDDs was carried out in 6083 schoolchildren 6 to 12 years of age from the capital cities of nine states in different areas of the country using the three indicators recommended by the World Health Organization: the prevalence of goitre, laboratory measurements of urinary iodine concentration in casual urine samples and serum thyroglobulin (Tg) levels. Serum levels of thyroxine (T4), triiodothyronine (T3) and thyroid-stimulating hormone (TSH), as well as urinary secretion of thiocyanate, which can affect the transport of iodine into thyrocytes, were also measured. Findings The prevalence of goitre in the different samples ranged from 12.2% to 77.7% and was 38.8% overall. The overall median urinary iodine concentration was 6.55 μg/dl, with the lowest median value having been found in Kosti city (2.7 μg/dl), situated in the centre of the country, and the highest (46.4 μg/dl) in Port Sudan, on the Red Sea coast. The highest mean serum Tg level (66.98 ng/ml) was found in Kosti city, which also had the highest prevalence of goitre. Conclusion IDDs still constitute a public health problem throughout urban areas in the Sudan and iodine deficiency appears to be the main etiological factor involved.

Adam A.M.A.,Taif University | Eltayeb M.A.H.,Sudan Atomic Energy Commission
Journal of Environmental Radioactivity | Year: 2012

Multivariate statistical techniques are efficient ways to display complex relationships among many objects. An attempt was made to study the radioactive data in two types of Sudanese phosphate deposits; Kurun and Uro phosphate, using several multivariate statistical methods. Pearson correlation coefficient revealed that a U-238 distribution in Kurun phosphate is controlled by the variation of K-40 concentration, whereas in Uro phosphate it is controlled by the variation of U-235 and U-234 concentration. Histograms and normal Q-Q plots clearly show that the radioactive variables did not follow a normal distribution. This non-normality feature observed may be attributed to complicating influence of geological factors. The principal components analysis (PCA) gives a model of five components for representing the acquired data from Kurun phosphate, where 89.5% of the total variance is explained. A model of four components was sufficient to represent the acquired data from Uro phosphate, where 87.5% of the total data variance is explained. The hierarchical cluster analysis (HCA) indicates that U-238 behaves in the same manner in the two types of phosphates; it associated with a group of four radionuclides; U-234, Po-210, Ra-226, Th-230, which the most abundant radionuclides, and all belong to the uranium-238 decay series. Two parameters have been adapted for the direct differentiate between the two phosphates. Firstly, U-238 in Uro phosphate have shown higher degree of mobility (CV% = 82.6) than that in Kurun phosphate (CV% = 64.7), and secondly, the activity ratio of Th-230/Th-232 in Uro phosphate is nine times than that in Kurun phosphate. © 2011 Elsevier Ltd.

Abowslama E.H.Y.,Sudan Atomic Energy Commission | Ebraheem E.,University of Khartoum | Sam A.K.,Sudan Atomic Energy Commission
Journal of Radioanalytical and Nuclear Chemistry | Year: 2014

This study was carried-out to leach uranium from rock phosphate using sulphuric acid in the presence of potassium chlorate as an oxidant and to investigate the relative purity of different forms of yellow cakes produced with ammonia, magnesia and sodium hydroxide as precipitants, as well as purification of the products with TBP and matching its impurity levels with specifications of the commercial products. Alpha-particle spectrometry was used for determination of activity concentration of uranium isotopes in rock phosphate, resulting phosphoric acid, and in different forms of the yellow cake. Likewise, atomic absorption spectroscopy was used for determination of impurities. On the average, the equivalent mass concentration of uranium was 119.38 ± 79.66 ppm (rock phosphate) and 57.85 ± 20.46 ppm (phosphoric acid) with corresponding low percent of dissolution (48 %) which is considered low. The isotopic ratio (234U:238U) in all stages of hydrometallurgical process was not much different from unity indicating lack of fractionation. Upon comparing the levels of impurities in different form of crude yellow cakes, it was found that the lowest levels were measured in hydrated trioxide (UO3·xH2O). This implies that saturated magnesia is least aggressive relative to other precipitants and gives relatively pure crude cake. Therefore, it was used as an index to judge the relative purity of other forms of yellow cakes by taking the respective elemental ratios. The levels of impurities (Fe, Zn, Mn, Cu, Ni, Cd and Pb) in the purified yellow cake were found comparable with those specified for commercial products. © 2013 Akadémiai Kiadó, Budapest, Hungary.

Adam A.A.,Taif University | Eltayeb M.A.H.,Sudan Atomic Energy Commission | Ibrahim O.B.,Taif University
Arabian Journal of Chemistry | Year: 2014

This study was carried out in a laboratory scale to recover uranium from Uro area phosphate ore in the eastern part of Nuba Mountains in Sudan. Phosphate ore samples were collected, and analyzed for uranium abundance. The results showed that the samples contain a significant concentration of uranium with an average of 310.3μg/g, which is 2.6 times higher than the world average of phosphate. The green phosphoric acid obtained from the samples was found to contain uranium in the range of 186-2049μg/g, with an average of 603.3μg/g, and about 98% of uranium content of the phosphate ore was rendered soluble in the phosphoric acid. An extraction process using 25% tributylphosphate, followed by stripping process using 0.5M sodium carbonate reported that more than 98% of uranium in the green phosphoric acid exists as uranyl tricarbonate complex, moreover, sodic decomposition using 50% sodium hydroxide showed that about 98% of the uranium was precipitated as sodium diuranate concentrate that is known as the yellow cake (Na2U2O7). Further purification and calcinations of the yellow cake led to the formation of the orange powder of uranium trioxide (UO3). The chemical analysis of the obtained uranium concentrates; yellow cake and uranium trioxide proved their nuclear purity and that they meet the standard commercial specification. The obtained results proved that uranium from Uro phosphate ore was successfully recovered as uranium trioxide with an overall recovery percentage of 93%. © 2010.

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