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alkej-529
The Effects of Vortex Generator Types on Heat Transfer and Flow Structure in a Rectangular Duct Flows
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    In this numerical study a detailed evaluation of the heat transfer characteristics and flow structure in a laminar and turbulent flow through a rectangular channel containing built-in of different type vortex generator has been a accomplished in a range of Reynolds number between 500 and 100,000.A modified version of ESCEAT code has been used to solve Navier-Stokes and energy equations. The purpose of this paper is to present numerical comparisons in terms of temperature, Nusselt number and flow patterns on several configurations of longitudinal vortex generator including new five cases. The structures of heat and flow were studied, using iso-contours of velocity components, vortices, temperature and Nusselt number. This study shows that the predicted structures of fluid flow, temperature fields and Nusselt number variation are strongly affected by the presence of the turbulators. Staggered arrangement gains high Nusselt number, also the lower and upper arrangements have higher Nusselt number than plane duct. High Reynolds number (higher air inlet velocity) will enhance the Nusselt number. Increase in ribs height will enhance the heat transfer as it works as surface area and turbulator at the same time. 

 

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Publication Date
Sun Mar 01 2020
Journal Name
Iraqi Journal Of Physics
Effect of Laser Energy and Repetition Rate on Holmium Plasma Emission
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The holmium plasma induced by a 1064-nmQ-switched Nd:YAG laser in air was investigated. This work was done theoretically and experimentally.  Cowan code was used to get the emission spectra for different transition of the holmium target. In the experimental work, the evolution of the plasma was studied by acquiring spectral images at different laser pulse energies (600,650,700, 750, and 800 mJ). The repetition rates of (1Hz and 10Hz) in the UV region (200-400 nm). The results indicate that, the emission line intensities increase with increasing of the laser pulse energy and repetition rate. The strongest emission spectra appeared when the laser pulse energy is 800mJ and 10 Hz repetition rate at λ= 345.64nm, with the maximum intensi

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Crossref
Publication Date
Thu Feb 01 2024
Journal Name
Journal Of Engineering
Public Procurement Crisis of Iraq and its Impact on Construction Projects
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The public procurement crisis in Iraq plays a fundamental role in the delay in the implementation of construction projects at different stages of project bidding (pre, during, and after). The procurement system of any country plays an important role in economic growth and revival. The paper aims to use the fuzzy logic inference model to predict the impact of the public procurement crisis (relative importance index and Likert scale) was carried out at the beginning to determine the most important parameters that affect construction projects, the fuzzy analytical hierarchy process (FAHP) to set up, and finally, the fuzzy decision maker's (FDM) verification of the parameter for comparison with reality. Sixty-five

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Crossref
Publication Date
Fri Jul 01 2016
Journal Name
Journal Of Economics And Administrative Sciences
Using system dynamics model and the statistical indicators for Road Map of "Green government departments" project In Iraq
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Abstract                                                         

The issue of the protection of the environment is a shared responsibility between several destinations and sectors, and constitutes a main subject in which they can achieve sustainable development. In the sectors of government programs can be set up towards the establishment of the government sector to the green environment, so to be the implementati

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Crossref
Publication Date
Tue Apr 01 2014
Journal Name
Journal Of Economics And Administrative Sciences
Evaluation Age and Gender for General Census of the population in Iraq by using nonparametric Bayesian Kernel Estimators
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The process of evaluating data (age and the gender structure) is one of the important factors that help any country to draw plans and programs for the future. Discussed the errors in population data for the census of Iraqi population of 1997. targeted correct and revised to serve the purposes of planning. which will be smoothing the population databy using nonparametric regression estimator (Nadaraya-Watson estimator) This estimator depends on bandwidth (h) which can be calculate it by two ways of using Bayesian method, the first when observations distribution is Lognormal Kernel and the second is when observations distribution is Normal Kernel

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Crossref
Publication Date
Wed Jun 01 2022
Journal Name
Canadian Journal Of Chemistry
Hydrogenation of pyridine and hydrogenolysis of piperidine over $γ$-Mo2N catalyst: a DFT study
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Increasing demands on producing environmentally friendly products are becoming a driving force for designing highly active catalysts. Thus, surfaces that efficiently catalyse the nitrogen reduction reactions are greatly sought in moderating air-pollutant emissions. This contribution aims to computationally investigate the hydrodenitrogenation (HDN) networks of pyridine over the γ-Mo2N(111) surface using a density functional theory (DFT) approach. Various adsorption configurations have been considered for the molecularly adsorbed pyridine. Findings indicate that pyridine can be adsorbed via side-on and end-on modes in six geometries in which one adsorption site is revealed to have the lowest adsorption energy (–45.3 kcal/mol). Over a nitr

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Publication Date
Mon Mar 01 2010
Journal Name
Al-khwarizmi Engineering Journal
Modeling and Simulation of Sensorless Speed Control of a Buck Converter Controlled Dc Motor
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This paper investigate a sensorless speed control of a separately excited dc motor fed from a buck type dc-dc converter. The control system is designed in digital technique by using a two dimension look-up table. The performance of the drive system was evaluated by digital simulation using Simulink toolbox of Matlab.

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Publication Date
Tue Oct 30 2018
Journal Name
Iraqi Journal Of Physics
Evaluation of radioactivity of cereals and legumes using a nuclear impact detector CN-85
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The research aims to evaluate the radioactivity in elected samples of cereals and legume which are wide human consumption in Iraq using Nuclear Track Detectors (NTDs) model CN-85.
The samples were prepared scientifically according to references in this field. After 150 days of exposure, the detector were collected and chemically treated according to scientific sources (etching chemical), nuclear effects have been calculated using the optical microscope.
Radon (222Rn) concentration and uranium (238U) were calculated in unit Bq/m3 and (ppm), the results indicate that the highest concentration of radon and uranium was in yellow corn where the concentration of radon was 137.17×102 Bq/m3 and uranium concentration 2.63 (ppm). The lowest

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Publication Date
Mon Mar 07 2022
Journal Name
Journal Of Educational And Psychological Researches
Analytical Study of Mathematics Textbooks in the Basic Education Stage in the Sultanate of Oman According to NCTM Standards
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The present study aimed to identify the availability of the National Council of Teachers of Mathematics (NCTM) standards in the content of mathematics textbooks at the basic education stage in the Sultanate of Oman. The study used the descriptive-analytical approach, adopting the method of content analysis through using a content analysis tool that included (43) indicators distributed on the four NCTM standards related to the field of geometry, after verifying their validity and reliability. The study population consisted of mathematics textbooks (first and second semesters) for ninth-grade students in the Sultanate of Oman in the academic year 2018/2019, while the sample consisted of Geometry units in the content of those books, which a

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Publication Date
Thu Jun 27 2019
Journal Name
Bulletin Of The Iraq Natural History Museum (p-issn: 1017-8678 , E-issn: 2311-9799)
MICROFACIES ANALYSIS AND BASIN DEVELOPMENT OF THE CENOMANIAN - EARLY TURONIAN SEQUENCE IN THE RAFAI, NOOR AND HALFAYA OIL FIELDS, SOUTHEASTERN IRAQ
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    The stratigraphic sequence of Cenomanian-Early Turonian is composed of Ahmadi, Rumaila, and Mishrif formations in the Rifai, Noor and Halfaya Oil Fields within the Mesopotamian Zone of Iraq, which is bounded at top and bottom by unconformity surfaces. The microfacies analysis of the study wells assisted the recognition of five main environments (open marine, basinal, shallow open marine, Rudist biostrome, and lagoon); these microfacies were indicative of a normal lateral change facies from shallow water facies to deeper water and open marine sediments.

 

    Ahmadi Formation (Early Cenomanian) is characterized by open marine sediments during the transgressive conditions, and would be

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Scopus (4)
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Publication Date
Tue Jan 02 2018
Journal Name
Journal Of Educational And Psychological Researches
Psychological social conflict and its relation with family parental style for adolescences from the intermediate stage student at governmental Hail school, in the light of economical levels and sex variables .KSA
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The current research attempts to examine the relationship between social-psychological conflict and their relation to family upbringing approaches among the adolescents of intermediate stage according to sex and economical level. To do this, the researcher prepared a questionnaire to measure social-psychological conflict that consisted of (32) item divided on four dimensions, and also she prepared a questionnaire to measure family upbringing approaches which composed of (28) item divided on four dimensions. The sample was (260) male and female student from intermediate stage chosen randomly. The results revealed that there were significant differences between social-psychological conflict which went to male, there was a negative correlat

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