[en] A performance index expressing minimum fuel consumption and high quality performance has been postulated as a criteria for optimal control of a nuclear reactor for rocket propulsion. In deriving the algorithm of optimal control using classical calculus of variation it has been found that an extremal relation exists between the heat generated in the reactor and the average core temperature. Therefore a second criteria for most credible start up conditions has been postulated in solving this problem of optimization of a nuclear rocket reactor. (orig.)

No abstract available

[en] This lecture is intended to give insight on the different types of nuclear research reactors constructed and operated in the world since the beginning of 50s. Since that time a large number of reactors with different types have been constructed and operated; different fuel and enrichment, different moderators, different design, operating features, etc. A classification based on reactor power size is adopted in this lecture demonstrate the different types of research reactors. Some characteristics featuring the objectives and use of the different types research reactors is given in the lecture which displays characteristic data as given in the IAEA directories of research reactors for 2 types widely used research reactors. 2 fig., 2 tab

[en] The present work provides an optimized model for fuel loading patterns in pressurized water reactors. The developed model satisfies the following objectives: A) An improved power distribution throughout the reactor core at the begining of the core cycle. This model provides also an acceptable power profile throughout the whole core cycle. The minimum peak-to-average power ratio was chosen as the objective characteriatic of the optimum loading. b) Less management effort, as for instance simple computer programme or small computer time, for generating optimized loading patterns. This is justified by: 1. Using an improved fuel grouping and region classifications. 2. Excluding many of the failed shuffling iterations due to either using the loading priority sequence in order to perfor a good initial loading or using the local reactivity requirement for initially accepting or rejecting a shuffle iteration before power calculation is made. Because of the vast number of possible fuel assembly allocations, it is not possible to obtain a strictly optimum solution for a given criteria function. In this work the number of feasible patterns is greatly reduced through the use of a logical set of shuffling rules which utilizes the radial power and reactivity distributions of each shuffling iteration. In order to calculate the two dimensional power distribution, a two dimensional simulated 1.5 group coarse mesh diffusion theory model is used. The results obtained shown that the proposed simple modified algorithm adopted is efficient and applicable in determining the optimum loading patterns when compared to results from previous publications

[en] The work reported in this paper presents the tasks completed or currently under completion for the renewal of the nuclear instrumentation and control system, radiation protection system and process instrumentation system for Egypt's first research reactor (ETRR-1). The mentioned tasks started in 1980. The work reported includes the procurement and installation procedures and gives also a historical background which introduces ETRR-1 and its operating history together with the need for and philosophy behind the renovation of the above mentioned systems which were first put in operation in 1961

[en] This paper describes the specifications of a computer code 'POWDS' for resolving the one-and-half group coarse mesh diffusion model. This model is based on the two group diffusion method, however, it takes into consideration the fact that the mean free path length of the fast group neutrons is comparatively long, and thus allowing for large space nodes in the fast group. For thermal energy group neutrons the space nodes ranging about 20 cm are of several mean free paths. Since most neutrons diffuse within the energy span of the fission spectrum thus the thermal leakage is neglected. The computer program 'POWDS' is written to calculate the power distribution inside the reactor core. The overrelaxated technique is used to accelerate the convergence and minimize the number of iterations. The computer running time for calculating one quarter core power distribution using this 1.5 group method is relatively small as compared with other methods. The low computer cost, the small dimension and the ease of adoption make this program of considerable use specially in determining fuel loading patterns in the in core fuel management calculations

[en] The optimization problem analyzed in this technical note is related to the thermal cycle parameters in nuclear power stations having steam generators. A parametric study is made for maximizing the electric power installed and hence minimizing the specific cost of installed power with respect to the average operating saturation temperature in the station thermal cycle. The analysis considers the maximum fuel cladding temperature as a limiting factor in the optimization process as it is related to the safe operation of the reactor. (author)

[en] The optimization problem analyzed in this paper is related to the thermal cycle parameters in nuclear power stations having steam generators. The optimization the specific cost of installed power with respect to the average operating saturation temperature in the station thermal cycle. The analysis considers the maximum fuel cladding temperature as a limiting factor in the optimization process as it is related to the safe operation of the reactor. 4 figs

[en] Diseases caused by Hepatitis B virus (HBV) have a worldwide distribution. Pakistan adopted the recommendations of World Health Organization (WHO) for routine universal infant vaccination against hepatitis B in 2002, currently being administered at 6, 10, and 14 weeks of age in a combination vaccine. This study was conducted to determine the immune response and anamnestic immune response in children, 9 months-10 years of age, after a 3-dose primary Hepatitis B vaccination. Methods: This cross sectional study was conducted in the Department of Paediatrics, King Edward Medical University/Mayo Hospital, Lahore, Pakistan, from January to June, 2014. A total of 200 children of either sex between the ages of 9 months to 10 years, docu mented to have received 3 doses of hepatitis B vaccines according to Expanded Program of Immunization (6,10,14 weeks) schedule in infancy, were recruited by consecutive sampling. The level of serum anti-HBsAb by ELIZA was measured. Children with anti-HBs titers =10 mIU/mL were considered to be immune. Those with anti-HBsAb levels <10 mIU/mL were offered a booster dose of infant recombinant hepatitis B vaccine. The second serum sample was obtained 21-28 days following the administration of the booster dose and the anamnestic immune response was measured. Data was analysed using SPSS 17 to determine the relation between time interval since last vaccination and antibody titer. Chi square test was applied. Results: Of the 200 children, protective antibody response was found in 58 percent. Median serological response was 18.60 (range 2.82-65.15). Antibody levels were found to have a statistically significant (p-value 0.019) negative correlation with the time since last administration of vaccine. A booster dose of Hepatitis B vaccine was administered to all non-responders, with each registering a statistically significant (p-value 0.00) anamnestic response. Conclusion: The vaccination schedule with short dosage interval was unable to provide protection to 42 percent of the study population. Introduction of birth dose of Hepatitis B vaccine to the existing schedule is recommended. (author)

[en] Patient with arterial hypertension and no definable cause are said to have essential, primary or idiopathic hypertension. A total of 100 patients suffering from essential hypertension and 100 control subjects with almost same mean age and sex distribution were enrolled in this study. Levels of serum uric acid, total cholesterol, TG, and HDL-c were determined by enzymatic colorimetric method. Serum LDL-c and VLDL-c was calculated by using Friedewald and Wilson's formulae. The study was aimed to find out the levels of serum uric acid and lipid profile in patients with essential hypertension and to compare them with levels of normal healthy individuals. Results show increased level of serum uric acid and lipid parameters except for HDL-c, which was significantly, decreased in patients with essential hypertension as compared to the control subjects. Variations in aforementioned parameters were also observed on comparing the obese and the non-obese patients. It can be concluded from the present study that the essential hypertension is associated with abnormalities in the levels of serum uric acid and lipid profile. (author)