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joe-2040
Numerical Simulation of 3D- Flow Structure and Heat Transfer for Longitudinal Riblet Upstream of Leading Edge Endwall Junction of Nozzle Guide Vane
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The simulation have been made for  3D flow structure and heat  transfer with and without

longitudinal riblet upstream of leading edge vane endwall junction of first stage nozzle guide vane .The research explores concept of weakening the secondary flows and reducing their harmful effects.Numerical investigation involved examination of the secondary flows ,velocity and heat transfer rates by solving the governing equations (continuity, Navier -stokes and energy equations ) using the known package FLUENT version (12.1).The governing equations were solved for three dimentional, turbulent flowe, incompressible with an appropriate turbulent model (k-ω,SST) .The numerical solution was carried out for 25 models of V-groove riblet with wide ranges of height (h) and space (s). The results indicated that, the riblet endwall junction was a powerful tool for controlling the flow structure, reducing secondary flow formation,and elimination the effect of heat transfer at leading edg and passage . The drag reduction produced by riblet was proportional with their height and space. V-groove riblet with dimension of (h=1.35mm and s=2.26mm) was found to be the most effective in reduction of drag (2.7%) and heat transfer (21%) so it was selected as an optimum dimension of riblet model. The results also showed that the drag reduction produced by riblet was proportional to their size. The riblet model had a great effect in elimination spanwise ,pitchwise velocities ,but strength the streamwise velocity .At leading edge ,the effect of secondary flow was extended up to 23% from span height and 35% upstream leading edge .The riblet model caused an increase in momentom at a region very close to leading edge and to move stagnation point very close to the leading edge.

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Publication Date
Tue Jan 01 2013
Journal Name
The Education Faculty Journal Of Baghdad University
Analyzing the Rhetorical Structure of Linguistics Dissertation Abstracts Written by Iraqi EFL Graduates
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Publication Date
Tue Jul 11 2023
Journal Name
Journal Of Educational And Psychological Researches
Employing Leadership Practices in Educational Institutions According to the Organizational Structure of DNA
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DNA, as the basis of every living cell, is one of the most important and influential scientific discoveries. This research aims to identify and compare the organizational DNA to the leadership practices of school principals in the Sultanate of Oman and to reveal the similarity between principals’ leadership practices and the structure of DNA. In addition, it intends to identify any statistically significant differences between the responses of the participants due to the study variables: gender, job title and experience. A questionnaire was designed and data were collected from a randomly selected sample composed of (100) teachers in the Sultanate of Oman. The study found limitless diversity in the characteristics of DNA of leadership

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Publication Date
Thu Sep 06 2018
Journal Name
Digest Journal Of Nanomaterials And Biostructures
HIGHER PHOTO SENSITIVITY OF Co-Y-OXIDE NANO STRUCTURE SYNTHESIZED BY HYDROTHERMAL METHOD
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In this work, Co-Y-oxide Nano Structure is successfully synthesized via hydrothermal method. The XRD analysis, SEM analysis, optical, electrical and photo sensing properties have been investigated for Co3O4 and Co-Y-oxide thin films. The X-ray diffraction (XRD) analysis reveals that all films are polycrystalline in nature, having cubic structure. The SEM images of thin films clearly indicates that Co3O4 possesses nanosphere like structure and flower like for Co-Y-oxide. The optical properties show that the optical energy gap follows allowed direct electronic transition calculated using Tauc equation and it increases for Co-Y-oxide. The photo sensing properties of thin films are investigated as a function of time at different wavelengths to

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Publication Date
Wed May 31 2017
Journal Name
Al-khwarizmi Engineering Journal
Corrosion control of Buried Low Carbon Steel Structure by Using Alteration Medias method
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Abstract

The aim of the present work is to control of metal buried corrosion by alteration the media method. This method depended on the characteristics of each media. The corrosion rates in different media (soil, sand, porcelanite stone and gravel) for specimens of low carbon steel were measured by two methods weight loss method and polarization method, weight loss measured by buried specimens in these medias separately for 90 days. The polarization method includes preparing of specimen and salt solutions have electrical resistivity equivalent electrical resistivity of these media. The corrosion rate of two method results in (soil > sand> porcelainte stone> gravel). The lower corrosion rate happene

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Publication Date
Thu Oct 31 2013
Journal Name
Al-khwarizmi Engineering Journal
Aeroelastic Behavior of a Wind Turbine Blade by a Fluid -Structure Interaction Analysis
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In this paper, a numerical model for fluid-structure interaction (FSI) analysis is developed for investigating the aeroelastic response of a single wind turbine blade. The Blade Element Momentum (BEM) theory was adopted to calculate the aerodynamic forces considering the effects of wind shear and tower shadow. The wind turbine blade was modeled as a rotating cantilever beam discretized using Finite Element Method (FEM) to analyze the deformation and vibration of the blade. The aeroelastic response of the blade was obtained by coupling these aerodynamic and structural models using a coupled BEM-FEM program written in MATLAB. The governing FSI equations of motion are iteratively calculated at each time step, through exchanging data between

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Publication Date
Wed May 10 2017
Journal Name
Australian Journal Of Basic And Applied Sciences
Photometric Viewpoint to the Structure of Spiral Galaxy NGC 3351 with griz-Filters
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The term ‘photometry’ refers to the accurate determination of the apparent brightness of an astronomical object. Until roughly 1980, nearly all astronomical photometry was done by means of analog measurements of photographic plates, or by analog or digital (photon-counting) techniques with photomultipliers. These photometers produced brightness readings which were typically displayed on dials, plotted on strip charts or printed on strips of paper, and it was often quite practical to analyse these raw data with pencil, paper and a slide rule or table of logarithms. However, during the late 1970s electronic area detectors for astronomy became more advanced: first, for a brief period, television-type cameras were employed, but these were s

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Publication Date
Sat May 01 2021
Journal Name
Journal Of Physics: Conference Series
Anatomical histological structure of the cerebellum in the Iraqi frog Rana ridibunda ridibunda
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Abstract<p>The current study was designed to investigate the histological structure of the cerebellum in the Iraqi frog <italic>Rana ridibunda ridibunda</italic>. The cerebellum was removed surgically from 20 Iraqi frogs, <italic>Rana ridibunda ridibunda</italic>, and preserved in fixative of 10% formalin solution for a period of 72 hr, then the histological sections were prepared by the method of paraffin. The results of the study showed that the cerebellum of the adult Iraqi frog is one of the rhombencephalon regions, and consists of three layers, molecular layer, purkinje cells layer, and granular layer. The present histological findings suggest that the cerebellum of the </p> ... Show More
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Publication Date
Tue Dec 15 2020
Journal Name
Al-academy
Sound Structure and Attraction Effectiveness in Graphic Design Field: منير جباري علي
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      What concerns the research is employing the modern technology  in a compatible way, because it has multiplied  with the visual  working functions and has grown  in a special way with the development of the digital graphic design field  which represents a crystallization  product according  to  investigation and experimentation mechanism within the field of the scientific research  in the design field and development of the skills of the first designing worker, who always seeks to find working and functional structures in order to produce a design  with a clear meaning by utilizing the technological  abilities including the acoustic tech

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Publication Date
Sat Oct 01 2016
Journal Name
Al–bahith Al–a'alami
From Structure to the Signal (Text and Discourse in the Semiotic Analysis)
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Care and attention to the structure in the sixties of the last century replaced the mark, and if the structure of Ms. pampered in research and studies, it has become the mark is also a spoiled lady .. But the relationship between the structure and the mark was not a break and break, but the relationship of integration, His themes are structural analysis, and these are intellectual themes that can not be surpassed in contemporary research, especially since semiotics have emerged from the linguistic inflection.

We have tried to distinguish between text and speech, which is a daunting task, as it seems that whenever the difference between them is clear and clear, we come back to wonder whether the text is the same discourse, and is

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Publication Date
Thu Sep 01 2022
Journal Name
Iop Conference Series: Earth And Environmental Science
Non-Diatomic Diversity and Community Structure in Hoor-Al- Azime Marshes, Iran
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Abstract<p>This study was conducted to delineate diversity and species composition of non-diatoms planktonic algae in Hoor- Al- Azime marshes, Iran. The samples were collected from four sites at monthly basis from April 2011 to March 2012. A total 88 taxa were identified, out of which (40 taxa, 45.45%) belonging to Cyanophyta followed by Chlorophyta (29 taxa, 32.96%), Euglenophyta (18 taxa, 20.45%) and (1 taxa, 1.14%) of Dinophyta recorded. Comparing species richness (65 taxa, 34.76%) at Shat- Ali (St4) was the highest and the lowest (34 taxa, 18.18%) was observed at Rafi (St2). Species occurrence was associated with temperature where in summer (66 taxa) and (25 taxa) encountered winter. The phy</p> ... Show More
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