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 aim of the research is to reveal the reality of teacher performance evaluation in the Sultanate of Oman in light of some global models. The study followed a qualitative descriptive research design. Seven forms of teacher formative and summative assessments were analyzed. Besides, an analytical template was developed, consisting of six areas related to the teaching performance of teachers. These included: lesson planning and preparation, learning environment, education, professional development, student academic, and community and parental partnership. The study reached a number of results; the most notable is the lack of change of forms for more than a decade despite the rapid development of the educational system in the sultanate in
... Show MoreThe construction of development is required to develop various economic sectors with the necessity to meet the various requirement of both individuals and institutions , or through the import process , which must be commensurate with the needs of the market and the economy and development. But in fact , we find that the process of import in Iraq after 2003 took a turn dangerous excesses on limits of philosophy and objectives of the import , which is reflected at the level of national production as well as the policy of dumping and given and the lack of matching a lot of goods and materials imported for Standards and Measures of quality and stands behind it causes many of them exposure to the market and weak sectors with an overlap betwee
... Show MoreThe study aims to demonstrate the significance of metaverse technology across various disciplines, academic degrees, scientific fields, and academic titles. It also aims to assess the level of knowledge and understanding of university teachers (research sample) regarding metaverse technology. Hence, the descriptive research methodology was based on the method of statistical survey in the sample. It involved a set of organized scientific steps to deduce data from the reality of the statistical sample and its nature in order to achieve the objectives of the study. In this study, a questionnaire was used as a tool to collect data from a random sample of approximately 121 teachers and instructors from the University of Baghdad. This app
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Abstract
Due to the momentum of winning in the streets of the city of Baghdad as a result of the large number of checkpoints so felt researcher to conduct a field visit to find out the main reasons that led to this congestion and to find practical solutions to mitigate wastage winning the arrival time citizen to where you want the least possible time.
This research aims to overcome the difficulties experienced by citizens to reach their places of work and reduce waste at the time of service and waiting time as well as reduce the cost of waiting.
Has emerged study a set of conclusions, including the use of model queue (G / G / C) and the mome
... Show MoreThis research is Interested in how the performance and implementation of factory production engine coolants of the General Company for Electrical Industries of its work, and to facilitate the flow of the decisions of senior management and access to all configurations, to ensure differentiation desired and reduce lost sales, resulting from poor scheduling of operations through the application of certain rules of scheduling operations in the production plant Engines Air-cooler, the objectives of research in identifying the best base and working to reduce the time and cost of Same Rules of Process which are considered the most influential of any organization and thr
... Show MoreThe problem of job burnout has become one of the main problems for researchers in social welfare organizations (social protection bodies) - one of the formations of the Ministry of Labor and Social Affairs. Its negative effects increased in light of the COVID-19 pandemic, and in light of the Corona pandemic, the pressures and burdens of workers varied, which resulted in high rates of anxiety, tension, and intellectual and physical exhaustion, and then negatively affected their efficiency in performing work at the individual and organizational level, especially after the increasing tasks of these Bodies in carrying out their role in achieving the general goals and objectives as beingThe general goals are that they are responsible for providi
... Show MoreObjective(s): The present study aims to evaluate the effectiveness of Health educational program on nurses' knowledge toward children pneumonia at Al-Amara City hospitals..
Methodology: A quasi –experimental study design two-study group (pretest-posttest 1 and posttest 2) carried out at Alzahrawy Hospital and Child and maternity hospital in Al Amara City to identify the effectiveness of the Health educational program on Nurses Knowledge toward Children pneumonia; the study was conducted between 1 of September 2019 to 1 of April 2020. A Purposive (Non-probability) sample is chosen for the present study. The size of sample is (60) nurses divided into two gr
... Show MoreIn this research various of 2,5-disubstituted 1,3,4-oxadiazole (Schiff base, oxo-thiazolidine , and other compounds) were synthesized from 2,5-di(4,4?- amino-1,3,4-oxadiazole ) which use quently synthesized from mixture of 4-amino benzoic acid and hydrazine in the presence of polyphosphorus acid. The synthesized compounds were characterized by using some Spectral data (UV, FT-IR, and 1H-NMR).