A detailed methodology is presented in this paper for the calculation of nucleate boiling safety margin (NBSM) in nuclear research reactors using a temperature function with three different thermal-hydraulic hot-spot analyses: nominal, cumulative and statistical for normal operating condition and coolant flow variation. A computer simulation program is developed for applying the methodology to the IRT-5000 reactor based on experimental core data. According to cumulative analysis as the overconservative approach, the NBSM at normal operating condition of thermal power 5 MW and coolant velocity 1.672 m/s was 2.3% with reactor power limit 5.13 MW. However, during power or coolant flow trip condition, transient nucleate boiling would occur for short period at reactor shutdown. Of great importance, variation of NBSM with reactor operating condition for the different hot-spot analyses is found to be of strong linear correlation such that one analysis is sufficient to specify the results of the other analyses.
In this study, concentrations of radon and uranium were measured for twenty six samples of soil. The radon concentrations in soil samples measured by registrant alpha-emitting radon (222Rn) by using CR-39 track detector. The uranium concentrations in soil samples measured by using registrar fission fragments tracks in CR-39 track detector that caused by the bombardment of U with thermal neutrons from 241 Am-Be neutron source that has flux of 5 ×103n cm-2 s-1.
The concentrations values were calculated by a comparison with standard samples The results show that the radon concentrations are between (91.931-30.645Bq/m3).
The results show that also the uranium concentrat
Universities are among spaces where it's important to ensure thermal comfort in indoor spaces, improving the occupants' well-being and productivity. The problem of the research was to study appropriate glazing systems for the spaces of the University of Baghdad because glazing systems are one of the most important elements of the indoor environments, and it has a major impact on the thermal performance of buildings. Glass is one of the most seasoned materials that are most utilized in the design. Since it is a diaphanous material, it allows sunlight to enter the building, increasing the space's temperature, cooling loads, and energy consumption in summer. The research followed the experimental method by studying and
... Show MoreThe fluctuation properties of energy spectrum, electromagnetic transition intensities and electromagnetic moments in nucleus are investigated with realistic shell model calculations. We find that the spectral fluctuations of are consistent with the Gaussian orthogonal ensemble of random matrices. Besides, we observe a transition from an order to chaos when the excitation energy is increased and a clear quantum signature of the breaking of chaoticity when the single-particle energies are increased. The distributions of the transition intensities and of the electromagnetic moments are well described by a Porter-Thomas distribution. The statistics of electromagnetic transition intensities clearly deviate from a Porter-Thomas distribution (i
... Show MoreThe right to property is one of the most prominent and most important of the fundamental rights that the individual enjoys, whether national or foreign, both of them have their own private property that may not be affected except for the requirements of the country's economic development or what is known as the public benefit, and the Iraqi legislator did not specify what is meant by the removal of foreign investment. Of the bilateral international agreements (BITS), as it determined its terms and methods, the properties of foreign investors may be expropriated in a direct and indirect way.
Seventy five adult virgin female Norway rats (60 experimental and 15 controls) were used toevaluate the effect of seeds of three herbs (Fennel, Cumin and Garden cress) on their mammaryglands. Experimental animals were fed with these herbs (each type of herb seeds was given to twentyexperimental rats) for fourteen days. Rats were sacrificed and mammary gland sections wereobtained, stained then morphometrically assessed. Serum prolactin level was performed too.Results revealed that Garden cress seeds are the strongest lactogenic agent among the three. BothFennel and Cumin seeds were shown to be very weak galactagogues.
Medication safety is an important part of the comprehensive patient safety term. Medication safety is gaining more attention as the World Health Organization set the goal of decreasing medication harm by (50%) for the next 5 years when launching the third global challenge. Studying medication safety in the risk groups such as young ages, children are crucial to learn more about the effect of medicines in this risk group since they are not included in the clinical trials. Adverse drug reaction is defined as any harm resulted from the drug itself during medical process journey, while medication errors are any harm resulted from the treatment process rather than the drug or it is the result of the failure in a step of the treatment process
... Show MoreIn this paper the effect of mixing TiO2 nanoparticles with epoxy resin is studied. The TiO2 nanoparticles would be synthesis and characterized by scanning electron microscopy (SEM), XRD FTIR, for two particle sizes of 50 and 25 nm. The thermal conductivity is measured with and without composite epoxy resin; the results showed that the thermal conductivity was increased as nanoparticle concentration increased too. The thermal conductivity was increased as particle size decreased.
Thermal conductivity of compacted bentonite is one of the most important properties where this type of clay is proposed for use as a buffer material. In this study, Lee's disc method was used to measure the thermal conductivity of compacted bentonite specimens. The experimental results have been analyzed to observe the three major factors affecting the thermal conductivity of bentonite buffer material. While the clay density reaches to a target value, the measurement is taken to evaluate the thermal conductivity. By repeating this procedure, a relationship between clay dry density and thermal conductivity has been established in specimens after adjusting the water contents of the bentonite by placing its specimens in a drying oven for diffe
... Show MoreA numerical investigation is adopted for two dimensional thermal analysis of rocket thrust chamber wall (RL10), employing finite difference model with iterative scheme (implemented under relaxation factor of 0.9 for convergence) to compute temperature distribution within thrust chamber wall (which is composed of Nickel and Copper layers). The analysis is conducted for different boundary conditions: only convection boundary conditions then combined radiation, convection boundary conditions also for different aspect ratio (AR) of cooling channel. The results show that Utilizing cooling channels of high aspect ratio leads to decrease in temperature variation across thrust chamber wall, while no effects on heat transferred to the
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