In this paper, a polymer-based composite material was prepared by hand Lay-up method consisting of epoxy resin as a base material reinforced by magnesium oxide powder once and silicon dioxide powder again and with different weight ratios (3, 6, 9 and 12) wt %. The three-point bending test was performed in normal conditions and after immersion in sulfuric acid. The results showed that the bending value decreased with the increase of the weighted ratio of the reinforcement material (MgO, SiO2). The Bending of samples reinforced by SiO2 was found to be less than the bending of samples reinforced by particles (MgO). For example, the bending of the SiO2 sample (0.32 mm) at the weighted ratio (3%) and for the MgO (0.18mm) sample at the weight ratio were the same weighted load (100 g). It was found that the bending values of all samples exceeded the value after immersion in sulfuric acid. For example, the percentage of weight (6%) at the load level (500 g) was changed from 1.16 mm in normal conditions to 1.48mm for the same weight ratio after immersion. In sulfuric acid diluted with 0.3N for 10 days at the same applied load.
In this study, Zinc oxide nanostructures were synthesized via a hydrothermal method by using zinc nitrate hexahydrate and sodium hydroxide as a precursor. Three different annealing temperatures were used to study their effect on ZnO NSs properties. The synthesized nanostructure was characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), Atomic force microscope (AFM), and Fourier Transform Infrared Spectroscopy (FTIR). Their optical properties were studied by using UV -visible spectroscopy. The XRD analysis confirms that all ZnO nanostructures have the hexagonal wurtzite structure with average crystallite size within the range of (30.59 - 34
... Show MoreThe last ten years observed a shift enormous scientific in the method and way that it deals professional with the cost accounting and reflected the result those shift enormous scientific of increase the competitive environmental that accompanied the emergence of a modern manufacturing environmental on surface the long roductive life and emergence advanced information technology that give a central focus of his important on client with growing global markets growth on a large scale.
The research aim to define the concept of cost awareness, the concept and methods of strategic cost management and the role of cost awareness for managers of industrial units in strategic of cost managem
... Show MoreThe fouling depositions of crude oil stream were studied theoretically in a shell and tube heat exchanger to investigate the effect of depositions on the heat transfer process. The employed heat exchanger was with steam flowing in the inner tubes and crude oil in the shell at different velocities and bulk temperatures. It is assumed that fouling occurs only on the heated stream side (crude oil). The analysis was carried out for turbulent flow heat transfer conditions with wide range of Reynolds number, bulk temperature and time. Many previously proposed models for fouling resistance were employed to estimate a new model for fouling rate. It is found that the fouling rate and consequently the heat transfer coefficient were affected by Rey
... Show MoreIs no longer a football player looks to sport as a means of entertainment and physical development. But become see as part of The economic and is getting in return for the effort of، Through a contract with a club to organize the activity which is called a contract of professional, This contract is similar to the rest of the contracts in terms of problems and dispute that arise during the implementation or after it ends because of the nature of sports to such disputes and privacy being subject to special rules (regulations, national and international professional) required that subject to judicial bodies private mission confined settle sports disputes these entities and is affiliated unions legal committees and the court of arbitration for
... Show MoreThe sol-gel preparation technique of transparent silica monoliths containing up to 0.5 M of samarium have been described. The sol-gel processing parameters are: acid catalyzed hydrolysis and controlled drying. The prepared monoliths are analyzed by X-ray diffraction, pycnometer measurements, Fourier transformation infrared spectroscopy and optical spectroscopy. The oscillator strengths of the Sm3+ ions in the silica monoliths are calculated. The results show a linear concentration dependence of some Sm3+ transitions in UV/Vis absorption spectra and formation of Sm3+ clusters inside the pores structure of silica monoliths at high Sm3+ concentration
This study was conducted to examine the anatomical aspects of
The promotion by its means lead a vital and important role at the level of all organizations, whether (industrial or service) in general, and financial markets in particular. The promotion is earns delved to be as one of the main operations which market uses it through various means of financial markets and companies which its shares listed in the aim of (finance or investment), with a view to the implementation and financing of public and private projects the one hand, or with a view to achieving profits through investment of speculative or... For other purposes, on the other hand.Accordingly, we find that the set of public and private goals joint between the financial markets and listed companies respectively, will serve the stra
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The grammatical tools (the letters of meanings) are of great importance in understanding the meanings of the Arabic sentences,
This research is a simple attempt to show how our venerable scholars employed the meanings of these tools when they interpreted the linguistic evidence, that is, the grammatical structure largely depends on the tool in forming the meaning within the sentences and employing the meanings of these grammatical tools in explaining the linguistic evidence by clarifying their significance in the contexts of their use and effectiveness. Synthesis of the meanings of grammatical tools is an important tool in understanding the linguistic structure in order to reveal its meaning.
... Show MoreIn this article, the lattice Boltzmann method with two relaxation time (TRT) for the D2Q9 model is used to investigate numerical results for 2D flow. The problem is performed to show the dissipation of the kinetic energy rate and its relationship with the enstrophy growth for 2D dipole wall collision. The investigation is carried out for normal collision and oblique incidents at an angle of . We prove the accuracy of moment -based boundary conditions with slip and Navier-Maxwell slip conditions to simulate this flow. These conditions are under the effect of Burnett-order stress conditions that are consistent with the discrete Boltzmann equation. Stable results are found by using this kind of boundary condition where d
... Show MoreBackground: The present study was carried out to compare shear bond strength of sapphire bracket bonded to zirconium surface after using different methods of surface conditioning and assessment of the adhesive remnant index. Materials and methods: The sample composed of 40 zirconium specimens divided into four groups; the first group was the control, the second group was conditioned by sandblast with aluminum oxide particle 50 μm, the third and fourth group was treated by (Nd: YAG) laser (1064nm)(0.888 Watt for 5 seconds) for the 1st laser group and (0.444 Watt for 10 seconds) for the 2nd laser group. All samples were coated by z-prime plus primer. A central incisor sapphire bracket was bonded to all samples with light cure adhesive res
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