The 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, and mass transport. The capability of these models to predict corrosion
rates in presence of corrosion products is examined and discussed. It is found that formation of corrosion products with
time decreases the corrosion rate (or mass transfer rate) at low Reynolds number and temperature while it increases the
corrosion rate at high Re and temperature. It increases momentum transport and this increase depends on temperature,
Reynolds number, and corrosion rate. Increasing roughness due to the formation of corrosion products causes
overestimation of analogy correlations results by increasing friction factor and decreasing corrosion rate.
Rock engineers widely use the uniaxial compressive strength (UCS) of rocks in designing
surface and underground structures. The procedure for measuring this rock strength has been
standardized by both the International Society for Rock Mechanics (ISRM) and American Society
for Testing and Materials (ASTM), Akram and Bakar(2007).
In this paper, an experimental study was performed to correlate of Point Load Index ( Is(50))
and Pulse Wave Velocity (Vp) to the Unconfined Compressive Strength (UCS) of Rocks. The effect
of several parameters was studied. Point load test, Unconfined Compressive Strength (UCS) and
Pulse Wave Velocity (Vp) were used for testing several rock samples with different diameters.
The predicted e
The national anthem is one of the most eloquent communicative discourses that the language establishes due to its deep impact on the audience and forms a broad mass base that interacts with the chanting of the national anthem. Moreover, communication is the cornerstone in building social and educational relations. From this point of view, the communicative approach studies language in the communicative context and its six important functions identified by linguist Roman Jacobson. The official UAE national anthem is considered as a model for expressing the enthusiasm of the Emirati Arab public, who is proud of their Arabism, loyalty and love of the homeland, because of the expressions that this anthem carries, urging the public to
... Show MoreAbstract:
This tribe had lived in Iraq since the first century A.D. Persia tried to
keep this tribe away from Iraq, but without result. The tribe managed to get
victory against Persia in the battle of Dhyqar.
When the Muslims had come to conquer Iraq, Rabi’a welcomed them
and takes part in that action.
That tribe helped the caliph Ali in the Jammal and Sifffen wars in order
to remain Iraq the center of the Islamic caliphates this tribe had felt very sad
and sorrowful when the caliphate become to the Umayyad . This tribe did not
give up, so this tribe did what could be done to help those who had revolted
against the Umayyad. Rabi’a did that in order to get ride of the Mudriat alsham,
and favored Rabi
Estimation of the tail index parameter of a one - parameter Pareto model has wide important by the researchers because it has awide application in the econometrics science and reliability theorem.
Here we introduce anew estimator of "generalized median" type and compare it with the methods of Moments and Maximum likelihood by using the criteria, mean square error.
The estimator of generalized median type performing best over all.
أثر تنوع الرؤى الاخراجية للاتجاهات والحركات المسرحية المعاصرة في أتساعالاشتراطات الجمالية لبنية الخطاب المسرحي + الامر الذي ادى الى انزياح مكوناتالعرض وعناصره ؛ ومنها المنظومة السردية للنص التي شكلت في بدايات المسرحجغرافية العرض المسرحي والمرتكز النظري والفكري الذي يمد العرض المسرحي أغلبتدفقه الجمالي وعنصر أستعلائي لعناصر العرض الاخرى ؛ وضمن التطورات اللاحقةأنسحب المخرج المسرحي من سطوة البنية النص
... Show MoreAbstract : This research has tackled about the role of Russia in the international policies which concerning with energy , So the most important states in the world that possesses huge energy resources to be more able in the control over the reality and future production programs and the distribution of global energy alike , the latter had effectively influence on the economic and developmental aspects within many countries in the world and its impacts on political decisions and perhaps effected too much in the dimensions of strategic policies . In this context of research , Russia has been developed a high energy policy of strategic planning in order to restoring Russia position and its global role by using its potential powerful streng
... Show MoreThe research aims to build a training program to develop the willpower in the kindergarten children. In order to achieve the objective of the research, the two researchers have developed a Training Program according to the following steps:
- Determining the general objective of the Training Program.
- Determining the behavioral objectives of the Training Program.
- Determining the content of the Training Program.
- Implementing the content of the Training Program sessions.
- Evaluating the Training Program.
The training program consisted of (15) sessions, each session included a set of parts (title, general objective, methods, time and place to implement the sessions, behavioral goals, tool
... Show MoreThe images and drawings reduce the intellectual, symbolic and cognitive dimensions inside them that make them an intermediary that imposes itself on the educational method, as they have become responsive to all the needs of the student in the modern era unlike the previous periods. The artistic direction of the illustrations in the scientific books meets the educational and pedagogical needs of the learner and their frame in an illustrative educational method that contributes in developing the student's abilities to benefit from the scientific curricula in the age of scientific and cognitive development.
Here, the researcher finds that the artistic direction of the illustrations lacks the achievement of scientific and technical p
... Show MoreThis study aims to identify the concepts of financial crisis and its reasons of creation , also explain the effects of the accounting disclosure and the International Accounting Standards in current financial crisis, In addition to, indicate the role of accounting in the reform of the financial system from the impact of financial crisis.
The methodology of this study orientied to two main aspects, the first is an identifying approach through exploring the opinion of financial experts, the second aspect is based on an analytical approach to satisfy the requirements of experts to get there opi
... Show More