The presence of natural radioactivity in soil and other materials results in internal and external exposure in twelve samples at Al_Dura Heating generator at south of Baghdad using NaI(Ti) detector .Therefore, it is desirable to determine the concentration of naturally occurring radionuclide's238 U 232Th and 40 K,.. natural radioactivity and associated radiation hazard in some soil samples. The natural radioactivity due to the presence of 238 U 232Th and40 K in soil samples was measured by gamma spectrometry using NaI(Tl) scintillation well-shaped detector. In this context, soil samples were collected from thirty different locations of southern Al-Dura thermal Power Plant.Radium equivalent activities were calculatedfor the analyzed samples to assess radiation hazards arising due to the presence of these radionuclide's in the samples most of the calculated radium equivalent activities are lower than the limit set in the OECD report at 370 Bq/K.The measured representative level index values for the investigated samples varied in 1.035- 0.375 & 0.630- 0.1380 Bq/kg the range external and internal hazard index (Hex,Hin) , The radiation hazard indices of soilwas also lower than the maximum suggested global value the values of the Hex and Hin indices must be less than unity (˂1) for the radiation hazard to be negligible the specific dose rates indoor (D) and the annual effective dose (DE) due to gamma radiation from building materials was calculated.The value of the representative gamma index (Iγr) for the all soil samples were greater than the unity (>1).
This paper deals with load-deflection behavior the jointed plain concrete pavement system using steel dowel bars as a mechanism to transmit load across the expansion joints. Experimentally, four models of the jointed plain concrete pavement system were made, each model consists of two slabs of plain concrete that connected together across expansion by two dowel bars and the concrete slab were supported by the subgrade soil. Two variables were dealt with, the first is diameter of dowel bar (12, 16 and 20 mm) and the second is type of the subgrade soil, two types of soil were used which classified according to the (AASHTO): Type I (A-6) and type II (A-7-6). Experimental results showed that increasing dowel bar diameter from 12 mm to 20 mm
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One-third of the total waste generated in the world is construction and demolition waste. Reducing the life cycle of building materials includes increasing their recycling and reuse by using recycled aggregates. By preventing, the need to open new aggregate quarries and reducing the amount of construction waste dumped into landfills, the use of recycled concrete aggregate in drum compacted concrete protects the environment. Four samples of PRCC were prepared for testing (compressive strength, tensile strength, flexural strength, density, water absorption, porosity) as the reference mix and (10, 15, and 20%) of fine recycled concrete aggregate as a partial replacement for fine natural aggregate by volume. The mix is designed according to
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The comparison of double informative priors which are assumed for the reliability function of Pareto type I distribution. To estimate the reliability function of Pareto type I distribution by using Bayes estimation, will be used two different kind of information in the Bayes estimation; two different priors have been selected for the parameter of Pareto type I distribution . Assuming distribution of three double prior’s chi- gamma squared distribution, gamma - erlang distribution, and erlang- exponential distribution as double priors. The results of the derivaties of these estimators under the squared error loss function with two different double priors. Using the simulation technique, to compare the performance for
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