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 Main think that be kept by the speech communication as a concept traditionally being expressed on the subject or a certain idea of a goal came on as needed functional addressed to recipients of benefits or likely to benefit from those rhetorical message through a speech importance and priority of the effect of not less than the effect of that letter, in science content role ends once you absorb it mentally, either in the art of design Valamadmon intellectual embodied through its interaction with the overall shape of the finished design, and often content is associated in the mind of the receiver through a letter communicative linked to the sense or the goal that meant the designer, and try to identify and explain. And meaning i
... Show MoreFinancial crisis is one of the topics that have attracted the interest of researchers in recently. The research focused on the issue of the crisis of the Asian Tigers and the mortgage crisis and comparing them in terms of causes and repercussions. It may meet most of the financial crises in many of its causes, factors, roots and results in the advanced and the developing countries. This crisis has its own pattern and its causes and nature and it is characterized by a crisis of cash liquidity and the collapse of many banks and declare bankruptcy and a sharp decline in stock prices and indices of the stock market and so far the common denominators among the causes but does not mean this There are differences between the financial c
... Show MoreLinguistic research according to modern curricula:
It is one of the important matters that occupy the ideas of those concerned with linguistic studies, whether Arabic or otherwise. Recent years have witnessed the advancement of this methodological approach, and books and studies in Arabic have been written on important, multifaceted issues, of grammatical and linguistic origins, and their balance with new developments and ideas attracted mostly from Western studies.
The comparative approach - as they call it - is one of the modern approaches that is based on balancing a language with other sisters belonging to its family, to reach similarities and differences between them, and to know the c
This research aims to analyze the impact of the United States policy of pressure and sanctions on changing Iran's conduct. Since the Islamic Revolution of Iran in 1979, the US has continuously pursued various policies towards Iran, aiming to change the regime by force or isolate it politically and economically. The main research question lies in the following: To what extent does the US pressure policy and its sanctions affect the conduct Iran?. This research discusses that the more there are economic and political alternatives to Iran, the more it will be challenging the US demands. Moreover, the more the US pursues a negotiating policy based on mutual interests, the more Iran will positively respond to American demands.
Bridging the Gap between Graphemes and Phonemes in the Phonetic Transcription
In his opus, Ted Hughes has annexed new and fresh territories of signification to the very notion of the literary animal. Building on the earlier modernist example of the Lawrencian legacy that dwells upon the question of animalism, Hughes seems to have stepped further into the terrain of the sheer struggle when, in his hands, the grotesquerie of survival and violence energizes the topos of the literary animal in his postmodern bestiary. In Hughes’s elemental poetic process this grotesquerie and violence stages the literary animal as a vital poetic device or motif that is finally restored to the primitive power of poetry. In his “Thrushes”, he thus defamiliarizes these tiny creatures’ acts of being to bring upfront into focus thi
... Show MoreIntrusion detection systems (IDS) are useful tools that help security administrators in the developing task to secure the network and alert in any possible harmful event. IDS can be classified either as misuse or anomaly, depending on the detection methodology. Where Misuse IDS can recognize the known attack based on their signatures, the main disadvantage of these systems is that they cannot detect new attacks. At the same time, the anomaly IDS depends on normal behaviour, where the main advantage of this system is its ability to discover new attacks. On the other hand, the main drawback of anomaly IDS is high false alarm rate results. Therefore, a hybrid IDS is a combination of misuse and anomaly and acts as a solution to overcome the dis
... Show MoreBackground: Lowering the amount of iodinated contrast material and tube voltage may increase pulmonary artery opacification and thrombus identification without compromising picture quality.
Objectives: To explore the efficiency of using lower tube voltage and a lower contrast medium dose for conducting computed tomography for pulmonary angiography (CTPA) aiming to increase its accuracy in detecting pulmonary thromboembolism (PTE).
Subjects and Methods:100 patients scheduled for CTPA with a preoperative diagnosis of PTE were grouped into two: group A, (50 patients) got 1 mL/kg at 120 kV and group B, (50 patients) received 0.5 mL/kg at 80 kV.The tec
... Show MoreIn this study, an efficient compression system is introduced, it is based on using wavelet transform and two types of 3Dimension (3D) surface representations (i.e., Cubic Bezier Interpolation (CBI)) and 1 st order polynomial approximation. Each one is applied on different scales of the image; CBI is applied on the wide area of the image in order to prune the image components that show large scale variation, while the 1 st order polynomial is applied on the small area of residue component (i.e., after subtracting the cubic Bezier from the image) in order to prune the local smoothing components and getting better compression gain. Then, the produced cubic Bezier surface is subtracted from the image signal to get the residue component. Then, t
... Show MoreThe objective of this study is to apply Artificial Neural Network for heat transfer analysis of shell-and-tube heat exchangers widely used in power plants and refineries. Practical data was obtained by using industrial heat exchanger operating in power generation department of Dura refinery. The commonly used Back Propagation (BP) algorithm was used to train and test networks by divided the data to three samples (training, validation and testing data) to give more approach data with actual case. Inputs of the neural network include inlet water temperature, inlet air temperature and mass flow rate of air. Two outputs (exit water temperature to cooling tower and exit air temperature to second stage of air compressor) were taken in ANN.
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