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joe-2019
Theoritical and Experimental Investigation of the Dynamical Behaviour of Complex Configuration Rotors
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The present work considers an alternative solution for a complex configuration of rotor discs by applying Galerkin Method. The theoretical model consists of elastic shaft carrying number of discs and supported on number of journal bearings. The equation of motion was discretized to finite degree of freedom in terms of the system generalized coordinates. The various effects of the dynamical forces and moments arising from the bearing, discs and shaft were included. Rayleigh beam model is used for analyzing the shaft while the discs are considered rigid . The validity and convergence of the present analysis was carefully checked by comparing with the Finite Element solution. An example of rotor consists of three different size discs and supported by two journal bearing was considered for the numerical solution .The results shows good agreements between the two methods ,where the maximum error not exceeds 5%. The convergence test showed that using few modes (not more than 6) are sufficient for the accurate analysis. The forward and backward whirl was investigated experimentally .The experimental results of a two discs rotor ,show a reasonable agreement where the maximum error not exceeds 11%. The unbalance response, Cambpell diagram, orbit response were plotted .The effects of geometry, disc sizes , location and arrangement on the unbalance response and natural frequencies of three discs rotor were further investigated .

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Publication Date
Thu Jan 09 2014
Journal Name
Ibn Al-haitham Jour. For Pure & Appl. Sci.
Effect of Thickness on the Electrical Conductivity and Hall Effect Measurements of (CIGS) films
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The influence of different thickness (500, 1000, 1500, and 2000) nm on the electrical conductivity and Hall effect measurements have been investigated on the films of copper indium gallium selenide CuIn1-xGaxSe2 (CIGS) for x= 0.6.The films were produced using thermal evaporation technique on glass substrates at R.T from (CIGS) alloy. The electrical conductivity (σ), the activation energies (Ea1, Ea2), Hall mobility and the carrier concentration are investigated and calculated as function of thickness. All films contain two types of transport mechanisms of free carriers, and increases films thickness was fond to increase the electrical cAnductivity whereas the activation energy (Ea) would vary with films thickness. Hall Effect analysis resu

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Publication Date
Mon Apr 01 2019
Journal Name
International Journal Of Research - Granthaalayah
CALCULATION OF THE STOPPING POWER OF ALPHA PARTICLES AND ITS RANGE IN BONE TISSU
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With the advancement of modern radiotherapy technology, radiation dose and dose distribution have significantly improved. as part of Natural development, interest has recently been renewed by treatment, especially in the use of heavy charged particles, because these radiation types serve theoretical advantages in all biological and physical aspects. The interactions of alpha particle with matter were studied and the stopping powers of alpha particle with Bone Tissue were calculated by using Zeigler’s formula and SRIM software, also the Range for this particle were calculated by using Mat lab language for (0.01-1000) MeV alpha energy.

Publication Date
Tue Jan 08 2019
Journal Name
Iraqi Journal Of Physics
Effect of thickness on the structure, morphology and A.C conductivity of Bi2S3 thin films
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Thin films samples of Bismuth sulfide Bi2S3 had deposited on
glass substrate using thermal evaporation method by chemical
method under vacuum of 10-5 Toor. XRD and AFM were used to
check the structure and morphology of the Bi2S3 thin films. The
results showed that the films with law thickness <700 nm were free
from any diffraction peaks refer to amorphous structure while films
with thickness≥700 nm was polycrystalline. The roughness decreases
while average grain size increases with the increase of thickness. The
A.C conductivity as function of frequency had studied in the
frequency range (50 to 5x106 Hz). The dielectric constant,
polarizability showed significant dependence upon the variation of
thic

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Publication Date
Sat Oct 04 2025
Journal Name
Infrastructures
Influence of Coarse Aggregate Geometry and Mineral Composition on the Durability of Asphalt Concrete
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The durability of asphalt concrete is highly dependent on the geometry and mineralogy of coarse aggregates, yet their combined influence on mechanical and moisture resistance properties is still not fully understood. This study evaluates the effects of coarse aggregate geometry, specifically flat and elongated particle ratios and angularity, as well as mineral composition (quartz versus calcite), on asphalt mixture durability. The durability of mixtures was evaluated through Marshall properties as well as moisture susceptibility indicators, including the tensile strength ratio (TSR) and index of retained strength (IRS). Statistical analyses (ANOVA and t-tests) were also conducted to confirm the significance of the observed effects.

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Publication Date
Wed Jan 01 2025
Journal Name
Journal Of Governance And Regulation
The impact of corporate governance and audit quality on value relevance of accounting information
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This study aims to investigate the relationship between corporate governance (CG) and audit quality (AQ) in the adequacy of the value relevance of accounting information (VRAI). The study sample included Iraqi firms listed on the Iraqi Stock Exchange (ISE) from 2010 to 2022. Nineteen firms were a research sample selected from 44 firms listed on the ISE. They chose to use the model (Ohlson, 1995) in measuring VRAI, which is based on measuring the absolute value of the level of value relevance to earnings per share (EPS) the absolute value of the book value suitability level VRAI. CG was measured through five factors: board size, gender of board members, independence of the board from the chief executive officer (CEO), ownership perce

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Publication Date
Tue Sep 19 2017
Journal Name
Al-academy
Peer Education Strategy and its Impact on the Development of Skill of Perspective Drawing
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       After the twenty – first century become  necessary for us motorcade era in educational a chevements by searching  for the best  strategies and teaching methods and  techniques  artotalbagesh  resorting to the strategy

Did not use in use in the teaching of the foreseeable  material  general by voice and teaching  perspective  for the student of the class fourth science

In particular ,so the researcher asking the question follows:

Can the peer education strategy to have an impact in perspective drawing skill development ?

   From here it demonstrated the importance of current research know the impact of  p

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Publication Date
Tue Jan 01 2019
Journal Name
Indian Journal Of Public Health Research &amp; Development
Comparison of the Cyclic Fatigue of Protaper Next, 2Shape and Hyflex EDM Using Glyde
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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
Fri Mar 31 2017
Journal Name
Journal Of Engineering
Openness and the Degree of Impact on Engagement Learner Department of Architecture Case Study
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        This paper concerns with openness concept in contemporary learning environment, which ranges from physical characters to its relation with learning efficiency and its output. Previous literatures differ to clear the effect of openness on the engagement between learner within themselves, and with this kind of spaces. Engagement means: active participation, the ability of making dialogue, self-reflection and the ability to explore and communicate with them and
within learning space. Research roblem was: The lack of knowledge about the effect of Openness on learner engagement with learning spaces. The two concepts were applied on three types of learning spaces in the Department of the Architectu

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Publication Date
Mon Apr 04 2022
Journal Name
Journal Of Educational And Psychological Researches
The Effect of Baska Style in Achievement and Creative Thinking among Students in the Fifth Grade Literary Material and Application Rhetoric
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The current research aims to identify the effect of Baska style on students’ achievement and the creative thinking in material rhetoric and the application of students for fifth grade literary. To achieve the study objectives, the researcher has designed an achievement test to measure group of students in the fifth grade literary in material application. The researcher chose a sample of 40 female students from Khansa School for Girls in Baghdad for the academic year (2014 - 2015), he applied the test on an exploratory sample consisted of 30 female students from the research community. The study resulted in being no statistically significant difference at the level of significance (0.05) between the mean scores of the experimental group

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