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.
The research aims to determine the role of the training strategy with its dimensions of (strategic analysis, formulation of training strategy, implementation of training strategy, evaluation) in the pioneering performance of the organization with its dimensions of (pre-planning , renewal and modernization, efficiency, effectiveness). Important and modern in pioneering performance and training strategy, and in recognition of the importance of the subject and the expected results of the surveyed banks, an analysis was made of the data obtained through field visits in addition to the questionnaire and interviews ,and the most prominent results that were reached were taking the research sample into consideration all the requirements of the trai
... Show MoreThe aim of this research was to evaluate the level of ball control in basketball. There was a great weakness in ball control that affected the mastery of many skills that affect the success of the team. The researcher also found a lack in training programs concerning ball control. The researchers used (9) special tests for ball control out of (41) test applied on young basketball players were (86). The researchers concluded that: 1. Criteria were set for test results of ball control. 2. A level of criteria was set for test results of ball control.
This research has tackled a scientific figure belongs to Koofi grammatical school. He is Abdullah Al-Tuaal who has occupied the fourth layer among the Koofi grammarians. There was a confusion between him and another Koofi grammarian from the same layer (Mohammed Bin Qaadim) in some old references. This research has clarified this confusion to affirm that they are two different grammarians.This research also tackles the scientific status of Al-Tuaal and the grammatical views that have been ascribed to him in addition to the analysis and discussion of these views. All this in the light of what has been mentioned in grammar books about the issues in which these views were stated.
In this paper the method of singular value decomposition is used to estimate the ridge parameter of ridge regression estimator which is an alternative to ordinary least squares estimator when the general linear regression model suffer from near multicollinearity.
Recently, a new secure steganography algorithm has been proposed, namely, the secure Block Permutation Image Steganography (BPIS) algorithm. The new algorithm consists of five main steps, these are: convert the secret message to a binary sequence, divide the binary sequence into blocks, permute each block using a key-based randomly generated permutation, concatenate the permuted blocks forming a permuted binary sequence, and then utilize a plane-based Least-Significant-Bit (LSB) approach to embed the permuted binary sequence into BMP image file format. The performance of algorithm was given a preliminary evaluation through estimating the PSNR (Peak Signal-to-Noise Ratio) of the stego image for limited number of experiments comprised hiding
... Show MoreMany changes took place in a number of Arab countries, most of which ended with the change of the ruling leadership and a new coming. The same change brought about the hopes of the people to turn the page of the past into a democracy through which to overcome the grievances of previous years and achieve justice in all its aspects. The same new grievances have been added to that precedent and justice has not yet been achieved. Here we try to address the justice that is applied in the stages of change or transitional stages, which have been called, ie transitional justice, which has mechanisms and conditions of different application between countries, each of which the conditions applied in them and through a review of these mechanisms bet
... Show MoreThe mechanical function of the heart is governed by the contractile properties of the cells, the mechanical stiffness of the muscle and connective tissue, and pressure and volume loading conditions on the organ. Although ventricular pressures and volumes are available for assessing the global pumping performance of the heart, the distribution of stress and strain that characterize regional ventricular function and change in cell biology must be known. The mechanics of the equatorial region of the left, ventricle was modeled by a thick-walled cylinder. The tangential (circumferential) stress, radial stress and longitudinal stress in the wall of the heart have been calculated. There are also significant torsional shear in the wall during b
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