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joe-2080
FLUTTER SPEED LIMITS OF SUBSONIC WINGS
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Flutter is a phenomenon resulting from the interaction between aerodynamic and structural dynamic forces and may lead to a destructive instability. The aerodynamic forces on an oscillating airfoil combination of two independent degrees of freedom have been determined. The problem resolves itself into the solution of certain definite integrals, which have been identified as Theodorsen functions. The theory, being based on potential flow and the Kutta condition, is fundamentally equivalent to the conventional wing-ection theory relating to the steady case. The mechanism of aerodynamic instability has been analyzed in detail. An exact solution, involving potential flow and the adoption of the Kutta condition, has been analyzed in detail. The solution is of a simple form and
is expressed by means of an auxiliary parameter K. The use of finite element modeling technique and unsteady aerodynamic modeling with the V-G method for flutter speed prediction was used on a fixed rectangular and tapered wing to determine the flutter speed boundaries. To build the wing the Ansys 5.4 program was used and the extract values were substituted in the Matlab program which is designed to determine the flutter speed and then predicted the various effects on flutter speed. The program gave us approximately identical results to the results of the referred researches. The following wing design parameters were investigated skin shell thickness, material properties, cross section area for beams, and changing altitude. Results of these calculations indicate that structural mode shape variation plays a significant role in the determination of wing flutter boundary.

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Publication Date
Fri Jan 01 2016
Journal Name
World Journal Of Experimental Biosciences
Detection of anti-Helicobacter pylori antibodies in sera of women with recurrent spontaneous abortion
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To determine the relationship between Helicobacter pylori infection and reproduction disorder (recurrent spontaneous abortion), twenty women patients who undergo spontaneous abortion during first trimester of pregnancy (20-38) years and have been investigated from 2015/12/1 -2016/3/1 and compared to fifteen healthy individuals. All subjects were carried out to measure anti-H. pylori IgA and anti- H. pylori IgG antibodies by enzyme linked immunosorbent assay (ELISA). There was significant elevation (p≤ 0.05) in concentration of anti- H. pylori IgG Abs (6.30± 0.99) compared to control group (4.48± 0.61) and IgA Abs (5.42 ± 0.90 U /ml) as compared to control group (3.92 ± 0.41 U/ml). The percentage of H. pylori IgG and IgA was 20% and 25

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Publication Date
Wed Jul 01 2026
Journal Name
Journal Of Baghdad College Of Dentistry
Effect of canal dryness and flaring on the accuracy of two electronic apex locators
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Background: This in vitro study evaluated the effect of canal dryness and flaring on the accuracy of two electronic apex locators for working length (WL) determination. Materials and methods: Sixty extracted teeth were used, after access opening was done, the occlusal surface was flattened to create stable reference point. The teeth were randomly divided into two equal main groups of flared and unflared group each one of 30 teeth. The flaring was done with Gates Glidden drills. The two main groups were further subdivided into two subgroups: dry canal and wet canal using 5.25% sodium hypochlorite groups, Electronic WL of each sample was determined using both Root ZX and i-Root apex locator. Consequently, histologic WL was determined by shav

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Publication Date
Mon Sep 30 2019
Journal Name
College Of Islamic Sciences
Irregularities dyed bin Faraj Imam Malik             Via                   Book of jurisprudence laws of Ibn Jizi
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It has been the name of the name forward dyed Ben Faraj when reading and my research in the books of jurisprudence, especially books Maliki school…
   And I saw that I offer a service to this favorite world, by devoting him to research on the issues that are unique to one of the opinions of Imam Malik (may Allah be pleased with him), and through browsing the books of Maliki, I found what I want in the book of jurisprudence laws, Imam Muhammad bin Ahmed bin Jazzi It has found six issues, and these issues, including what he had a single opinion of the doctrine, and what one of the opinion of Imam Malik, has presented the provisions of these issues to other schools of jurisprudence, and simplified research Vqarna in term

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Publication Date
Mon Jan 01 2018
Journal Name
Matec Web Of Conferences
Effect of internal curing on performance of self-compacting concrete by using sustainable materials
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This paper is devoted to investigate the effect of internal curing technique on the properties of self-compacting concrete. In this study, self-compacting concrete is produced by using limestone powder as partial replacement by weight of cement with percentage of (5%), sand is partially replaced by volume with saturated fine lightweight aggregate which is thermostone aggregate as internal curing material in three percentages of (5%, 10%, 15%) for self-compacting concrete, and the use of two external curing conditions which are water and air. The experimental work was divided into three parts: in the first part, the workability tests of fresh self-compacting concrete were conducted. The second part included conducting compressive str

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Publication Date
Mon Dec 05 2022
Journal Name
Baghdad Science Journal
Analysis of Fuel Burnup and Transmutations at High Burnup of Sodium Fast Breeder Reactor
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In this paper, the Monte Carlo N-Particle extended  computer code (MCNP) were used to design a model of the European Sodium-cooled Fast Reactor. The multiplication factor, conversion factor, delayed neutrons fraction, doppler constant, control rod worth, sodium void worth, masses for major heavy nuclei, radial and axial power distribution at high burnup are studied. The results show that the reactor breeds fissile isotopes with a conversion ratio of 0.994 at fuel burnup 70 (GWd/T), and minor actinides are buildup inside the reactor core. The study aims to check the efficiency of the model on the calculation of the neutronic parameters of the core at high burnup.

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Publication Date
Tue Aug 20 2019
Journal Name
Political Sciences Journal
Moved movement the dynamics of conflict and the restructuring of balance maps in Syria
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This study deals with the absence of state control over the whole of the Syrian geography in creating an environment conducive to the emergence of a new force represented by armed groups and organizations that point to fundamental changes in the conflict and to transform competition for control over the land into a struggle for influence. Which in itself represents the prospects of change in the Syrian scene, and that understanding their interests requires shedding light on the extent of the continuation of this competition and the conflict on land and expansion at the expense of the other, and thus contribute to complicate the Syrian scene, especially after attempts to bite Of land and annexation to each party's areas of influence, espe

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Publication Date
Sun Nov 01 2020
Journal Name
Journal Of Engineering
Preparation of Nano Zinc Oxide and its Application in the Photocatalytic Degradation of Ampicillin
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This study was undertaken to prepare Nano zinc oxide (ZnO) by precipitation and microemulsion methods. Scanning electron microscopy (SEM), X-ray diffraction (XRD), FTIR spectrometry, atomic force microscopy (AFM), and Brunauer Emmett Teller (BET) surface area were the techniques employed for the preparation. The particle size of prepared nano ZnO was 69.15nm and 88.49nm for precipitation and microemulsion methods, respectively, which corresponded to the BET surface area 20.028 and 16.369m2/g respectively. The activity of prepared nano ZnO as a photocatalyst was estimated by the removal of ampicillin (Amp) under visible light. This study, therefore, examined the effect of pH in the range of 5-11, initial concen

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Publication Date
Fri Feb 01 2019
Journal Name
Journal Of Economics And Administrative Sciences
Reflecting the Faithful economic representation of accounting practices on the quality of accounting information
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Where the accounting system in Iraq is still using many of these accounting practices according to the legal requirements to measure assets and liabilities away from the measurement that results in information representing the economic essence and represent honestly the financial situation and financial performance and future cash flows, and the needs of users of financial reports to useful accounting information adopted The International Accounting Standards Board (IASB) represents the true representation of accounting information in accordance with the concept of economic substance, which is the basis for the preparation and development of international accounting standards, and because accounting is part of the

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Publication Date
Mon Sep 30 2024
Journal Name
Joiv : International Journal On Informatics Visualization
Evaluation of the Performance of Kernel Non-parametric Regression and Ordinary Least Squares Regression
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Researchers need to understand the differences between parametric and nonparametric regression models and how they work with available information about the relationship between response and explanatory variables and the distribution of random errors. This paper proposes a new nonparametric regression function for the kernel and employs it with the Nadaraya-Watson kernel estimator method and the Gaussian kernel function. The proposed kernel function (AMS) is then compared to the Gaussian kernel and the traditional parametric method, the ordinary least squares method (OLS). The objective of this study is to examine the effectiveness of nonparametric regression and identify the best-performing model when employing the Nadaraya-Watson

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Publication Date
Sun Nov 27 2022
Journal Name
Al–bahith Al–a'alami
Gender stereotyping and its relationship to the level of performance of public relations employees
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This article focuses on the relationship of gender to the effectiveness of both women and men in public relations work. Its aim is to identify the extent to which public relations employees are aware of the concept of gender, and to reveal the role of the institution in determining certain roles for both women and men at work, as well as to find out which employees are most effective in public relations activities within the institution.

The researcher uses public relations employees and officials in Iraqi ministries as a research sample to capture the point of view of both parties on the effectiveness of workers in public relations based on the definition of gender. The sample consists of 396 individuals

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