Numerical simulations have been carried out on the solar chimney power plant systems. This paper gives the flow field analysis for a solar chimney power generation project located in Baghdad. The continuity, Naver-stockes, energy and radiation transfer equations have been solved and carried out by Fluent software. The governing equations are solved for incompressible, 3-D, steady state, turbulent is approximated by a standard k - model with Boussiuesq approximation to study and evaluate the performance of solar chimney power plant in Baghdad city of Iraq. The different geometric parameters of project are assumed such as collector diameter and chimney height at different working conditions of solar radiation intensity (300,450,600,750 and 900 W/m2) to gain the optimal designed structure. The results show that the change of collector diameter and chimney height has considerable effects on the performance of the system. The velocity increase when the collector diameter and chimney height increase and reach to the maximize value at H=D 12 m and when solar intensity (900 W/m2). The study shows that Iraqi weather are suitable for this system.
The study aimed to identify the reality of the application of cost accounting system in the contracting institutions in Saudi Arabia, and the extent of the reflection of the application of this system on the effectiveness and efficiency of the general performance of these institutions. Where the research community consists of the contracting institutions operating in the Saudi Arabia, and then a suitable random sample was selected from seventy one institutions. The researchers used the historical method to track the previous studies as well as the descriptive approach to conducting the field study. The study data were analyzed by SPSS statistical program.
The results of this study conclude that there is a
... Show MoreThe principle in the language is that each word has one meaning. This is because the purpose of language development is for understanding, understanding, and communication between people. The language is sounds with which each people expresses their Arabic language did not stop at this point, but rather needed another next stage or to convey additional features or characteristics that would qualify it. To be the language of the Qur’an and revelation, and capable of carrying this heavy burden.
Conclusion The observation of the phenomenon of structural evolution of the international system and its instability on a particular situation, by its transition from unipolar to polarity to bipolarism and then to unilateralism in the early 1990s led by the United States, and to the present moment, To say that the structure by which the hierarchy of superpowers or the regime is directed in terms of its various capacities that qualify it, and with the consent of the rest of the States directing the regime to lead and lead the world's first place, has no direct relation to the stability of this system, I hope other more influential in its stability. The structure of the new international order will be completely different in terms of the r
... Show Moreالنظام السياسي في كوريا الشمالة
Abstract:
This study seeks to shed light on the important processes are linked to the impact of accounting information on the behavior of producer and user of information and are urging informational and informational use. That accounting as a system of accounting information and functions of the delivery of information to decision makers Under behavioral entrance to the formulation of accounting theory should be taken into account Othertlk accounting information in the behavior of the decision maker which requires an explanation of human behavior and predictable.
On the other hand that the accounting information that should be delivered to the decision maker will affect your beha
... Show MoreObjectives: Successful endodontic treatment outcome requires effective shaping and cleaning of root canals. This study aims to evaluate the smear layer removal after continuous chelation (CC) ) NaOCL\HEDP( and sequential chelation (SC) )NaOCL\EDTA( and their influence on the push-out bond strength (POBS) of Bio-C sealer. Materials and Methods: Palatal roots of the maxillary first molar (n=72) were divided into four groups (n=18) as follows: 3% NaOCL, SC: 3% NaOCL followed by 17% EDTA, CC: 3% NaOCL \9% HEDP and Distilled water. Thirty-two roots (n=8/group) were split longitudinally for smear layer evaluation using SEM. Forty roots were obturated with Guttapercha and Bio-C sealer using a single cone technique. Thre
... Show MoreGas lift is one of the most important artificial lift methods for increasing oil production, as wells often require this method after the reservoir's energy has decreased. In this research, an optimal gas lift system is designed for five horizontal wells in the Ahdab oil field, which suffers from low production. At the same time, water cut in some of these wells reaches 66%, while the productivity index is low in others, which makes the challenges clear, and a deep analysis is needed to find an optimal system. The Pipesim program is used to design the optimal gas lift system, which contains features that facilitate the implementation of the appropriate design and provide the ability to analyze and determine the optimal design v
... Show MoreThe effect of time (or corrosion products formation) on corrosion rates of carbon steel pipe in aerated 0.1N NaCl
solution under turbulent flow conditions is investigated. Tests are conducted using electrochemical polarization
technique by determining the limiting current density of oxygen reduction in Reynolds number range of 15000 to 110000
and temperature range of 30 to 60oC. The effect of corrosion products formation on the friction factor is studied and
discussed. Corrosion process is analyzed as a mass transfer operation and the mass transfer theory is employed to
express the corrosion rate. The results are compared with many proposed models particularly those based on the
concept of analogy among momentum, heat,
