In this study, some attenuation parameters of gamma shields were studied. This shields consisting of composite materials of Unsaturated polyester as a base material and Nano iron oxide (Fe2O3) and, micro iron (Fe) as reinforcement materials at different percentages (1, 3,5,7and 9)wt%, and with different thickness (1, 1.5, 2, 2.5, 3, 3.5and 4) cm. The results showed that the use of nanoparticles is better than the microparticales in the field of radiation shielding. It has been shown that the values of attenuation parameters of gamma it bitter in the case of nanoparticles than case of the use of micro material.
The research dealt with the case stock repurchase policy of Emaar Real Estate Company one of listed companies in Dubai Stock exchange. The research has launched from the cognitive dimensions of repurchasing policy which took great concern in the literatures of financial management, and also this policy became as substitute for distributing the monitory profit in the last three decades in the international financial markets, but it did not get any importance in the Arab Markets such as that of the Arab Gulf in addition to the Iraqi Stock Exchange.
The research summarized a set of conclusions, the most important one was the consistence of analysis result with the test of the major two hypotheses (The first
... Show MoreA field experiment is conducted to study the effect of different levels of peat (0, 25, 50, 75, and 100 Mg ha-1 to uncropped and cropped soil to wheat. Soil samples are taken in different period of time (0, 3, 30, 60, 90, 120, and 180 days after cultivation to determine (NaHCO3-Exteractable P at 3 different depths (0-10, 10-20, and 20-30 cm). Field Experiment is conducted in a randomized complete block design (RCBD) with four replicates. Wheat, Al-Rasheed variety, is cultivated as a testing crop. The entire field is equally dived in two divisions. One of the two divisions is cultivated to wheat and the second is left uncropped. The effect of five levels of peat namely 0, 25, 50, 75, 100 Mg ha-1 is investigated. Soils are fully analyzed
... Show MoreElectronic properties such as density of state, energy gap, HOMO (the highest occupied molecular orbital) level, LUMO (the lowest unoccupied molecular orbital) level and density of bonds, as well as spectroscopic properties like infrared (IR), Raman scattering, force constant, and reduced masses for coronene C24, reduced graphene oxide (rGO) C24O5and interaction between C24O5and NO2gas molecules were investigated. Density functional theory (DFT) with the exchange hybrid function B3LYP with 6-311G** basis sets through the Gaussian 09 W software program was used to do these calculations. Gaussian view 05 was em
... Show MoreIn this work, a functional nanocomposite consisting of multi walled carbon nanotubes combined with nanoparticles of silver and Pomegranate peel extract (MWCNTs- SNPs -NPGPE) was successfully synthesized using ultra sonic technique. The nanocomposite has been characterized using Transmission electron microscope (TEM), XRD, Energy dispersive X-ray spectroscopy (EDS) UV-Vis and FTIR. The obtained results reveal that the MWCNTs-SNPs-NPGPE nanocomposite exhibits form of nanotubes with rough surfaces and containing black spots, which are the silver nanoparticles. The dimensions of this tube are 161 nm in length and 60 nm in width with nanoparticles of silver not exceeding 20 nm. The XRD pattern of the prepared MWCNTs-SNPs-NPGPE nanocomposite s
... Show MoreThe problem of present study is determined by answering the following questions:
1) What is the effect of using the oral open- ended questions on Students' achievement in the third-stage of Arabic department in the college of Education? 2) What is the effect of the oral open-ended questions on developing the creative thinking of students in
... Show MoreToxic dyes are commonly discharged into waste waters and dyes are extensively used in the textile industry so it is necessary to find out efficient and eco-friendly method for treating waste waters resulting from industrial effluences. To achieve this aim the fungus Trichoderma sp. is employed into two lines: first line was self – immobilized fungal pellets in (Czapek – Dox medium) to adsorbs two dyes crystal violet, congo red by concentrations 0.01, 0.02, 0.03, 0.04, 0.05, 0.06 mg/L to both dyes, PH 2, room temperature with shaker in ( hrs.2,hrs.4,hrs.24) , by Uv- Visible spectrum . the removal efficiency of 0.05 mg/L crystal violet by Trichoderma sp was 96%. but there was no remova
... Show MoreFaujasite type NaY zeolite catalyst was prepared from locally available kaolin, then the prepared NaY zeolite have been modified by exchanging of sodium ion with ammonium to produce NH4Y zeolite. NH4Y zeolite was converted to HY zeolite by ion exchanging with oxalic acid. Zinc and nickel promoters have been added to the prepared HY zeolite catalyst, and the effect of these promoters on the catalytic activity of the prepared HY catalyst was studied in fluid catalytic cracking process using light gas oil as a feedstock. The experimental results show that the promoted catalyst gives higher gas oil conversion and gasoline yield than HY zeolite catalyst at the same reaction temperature and WHSV. It was also found that the promoted catalyst gi
... Show MoreIn the present work, asphaltenes and resins separated from emulsion samples collected from two Iraqi oil wells, Nafut Kana (Nk) and Basrah were used to study the emulsion stability. The effect of oil resins to asphaltene (R/A) ratio, pH of the aqueous phase, addition of paraffinic solvent (n-heptane), aromatic solvent (toluene), and blend of both (heptol) in various proportions on the stability of emulsions had been investigated. The conditions of experiments were specified as an agitation speed of 1000 rpm for 30 minutes, heating at 50 °C, and water content of 30%. The results showed that as the R/A ratio increases, the emulsion will be unstable and the amount of water separated from emulsion increases. It was noticed that the em
... Show MoreThe study aims at showing the effect of basil oil on the sensory properties of the laboratory biscuits. the results show the sensory valuation before and after the storage. the (A4) equation exceeds 15% of T exchange (3 , 4 , 5 g. basil 19 , 55 g . fats )in most of the studied sensuous qualities. Then, the (A5) equation of 20% exchange percentage (4.60g. basil oil + 18.40g. fats). Then, the (A3) equation of 10% exchange percentage (2.30g. basil oil + 20.70g. fats). Then the (A2) equation of 5% exchange percentage (1.5g. basil oil + 21.85g. fats). Finally, the control equation (A1) received the lower value of sensuous evaluation and general acceptance. Abstract differences also appeared at denotation level 0.05 between the (A2)
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