Preferred Language
Articles
/
alkej-173
Aeroelastic Behavior of a Wind Turbine Blade by a Fluid -Structure Interaction Analysis
...Show More Authors

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 the structure and fluid by using a Newmark’s implicit time integration scheme. The results obtained from this paper show that the proposed modeling can be used for a quick assessment of the wind turbine blades taking the fluid-structure interaction into account. This modeling can also be a useful tool for the analysis of airplane propeller blades.

View Publication Preview PDF
Quick Preview PDF
Publication Date
Sun Sep 07 2014
Journal Name
Baghdad Science Journal
Deriving the Composite Simpson Rule by Using Bernstein Polynomials for Solving Volterra Integral Equations
...Show More Authors

In this paper we use Bernstein polynomials for deriving the modified Simpson's 3/8 , and the composite modified Simpson's 3/8 to solve one dimensional linear Volterra integral equations of the second kind , and we find that the solution computed by this procedure is very close to exact solution.

View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Wed Jul 20 2022
Journal Name
Journal Of Materials Engineering And Performance
High Speed Shock Peening by Fiber Laser for Al Alloy 6061-T6 Thin Sheets
...Show More Authors

Under cyclic loading, aluminum alloys exhibit less fatigue life than steel alloys of similar strength and this is considered as Achilles's heel of such alloys. A nanosecond fiber laser was used to apply high speed laser shock peening process on thin aluminum plates in order to enhance the fatigue life by introducing compressive residual stresses. The effect of three working parameters namely the pulse repetition rate (PRR), spot size (ω) and scanning speed (v) on limiting the fatigue failure was investigated. The optimum results, represented by the longer fatigue life, were at PRR of 22.5 kHz, ω of 0.04 mm and at both v's of 200 and 500 mm/sec. The research yielded significant results represented by a maximum percentage increase in the fa

... Show More
View Publication
Scopus (1)
Scopus Clarivate Crossref
Publication Date
Sun Sep 05 2010
Journal Name
Baghdad Science Journal
The Composition operator on hardy space H2 Induced by ?(z)=sz+t where , and
...Show More Authors

We study in this paper the composition operator of induced by the function ?(z)=sz+t where , and We characterize the normal composition operator C? on Hardy space H2 and other related classes of operators. In addition to that we study the essential normality of C? and give some other partial results which are new to the best of our knowledge.

View Publication Preview PDF
Crossref
Publication Date
Sun Sep 04 2016
Journal Name
Baghdad Science Journal
Study the Shielding Properties against Gamma-rays for Epoxy Resin Reinforced by Different materials
...Show More Authors

In the present work the Buildup factor for gamma rays were studied in shields from epoxy reinforced by lead powder and by aluminum powder, for NaI(Tl) scintillation detector size ( ×? ), using two radioactive sources (Co-60 and Cs-137). The shields which are used (epoxy reinforced by lead powder with concentration (10-60)% and epoxy reinforced by aluminum powder with concentration (10-50)% by thick (6mm) and epoxy reinforced by lead powder with concentration (50%) with thick (2,4,6,8,10)mm. The experimental results show that: The linear absorption factor and Buildup factor increase with increase the concentration for the powders which used in reinforcement and high for aluminum powder than the lead powder and decrease with inc

... Show More
View Publication Preview PDF
Crossref
Publication Date
Mon Nov 15 2021
Journal Name
Egyptian Journal Of Chemistry
Green Synthesis by Zygophyllum Coccineum Leaves Extract for Preparing ZnO Nanoparticles, and Characteristics Study.
...Show More Authors

View Publication
Scopus (2)
Scopus Clarivate Crossref
Publication Date
Sun Aug 01 2021
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Robust Tests for the Mean Difference in Paired Data by Using Bootstrap Resampling Technique
...Show More Authors

The paired sample t-test for testing the difference between two means in paired data is not robust against the violation of the normality assumption. In this paper, some alternative robust tests have been suggested by using the bootstrap method in addition to combining the bootstrap method with the W.M test. Monte Carlo simulation experiments were employed to study the performance of the test statistics of each of these three tests depending on type one error rates and the power rates of the test statistics. The three tests have been applied on different sample sizes generated from three distributions represented by Bivariate normal distribution, Bivariate contaminated normal distribution, and the Bivariate Exponential distribution.

View Publication Preview PDF
Crossref
Publication Date
Sun Oct 22 2023
Journal Name
Iraqi Journal Of Science
Genetic Diversity Among Some Aspergillus flavus Isolates by Using Inter simple sequence repeats (ISSR)
...Show More Authors

Aspergillus flavus isolates which are considered on conidial shape through microscopic examination and mycelial colour through cultural properties . Primary screening for the ability of A. flavus isolates for aflatoxin production was determined using A.flavus parasiticus agar medium (AFPA) as well , 7 isolates from 11 isolates give a positive result by the presence of bright yellow-orange pigments indicated the presence of aflatoxins. Molecular genetics techniques using DNA polymorphism have been increasingly used to characterize and identify genetic diversity and relationships among eleven A. flavus isolated from different source using the ISSR(inter simple sequence repeats) technique. Three universal primers designed at University of B

... Show More
View Publication Preview PDF
Publication Date
Tue Jan 02 2018
Journal Name
Journal Of The Faculty Of Medicine Baghdad
Breast Cancer Subtypes among Iraqi Patients: Identified By Their ER, PR and HER2 Status
...Show More Authors

Background: Breast cancer ranks the first among the Iraqi population since three decades and is currently forming a major public health problem being the second cause of death women. Novel management of breast cancer depends upon precise evaluation of their molecular subtypes; identified by Hormone (Estrogen and Progesterone) receptors and HER2 contents of the primary tumor.
Objective: To assess the rates of the different molecular breast cancer subtypes in the examined tissue specimens belonging to females diagnosed with breast cancer in Iraq; correlating the findings with those reported in the literature at the regional and global levels.
Patients and Methods: This retrospective study documented the findings of tissue biopsy exam

... Show More
View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Sat Dec 01 2012
Journal Name
Journal Of Economics And Administrative Sciences
Eatimation Availability Function Through Determination The Optimal Imperfect Preventive Maintenance Period By using Simulation
...Show More Authors

This paper deals with the modeling of a preventive maintenance strategy applied to a single-unit system subject to random failures.

According to this policy, the system is subjected to imperfect periodic preventive maintenance restoring it to ‘as good as new’ with probability

p and leaving it at state ‘as bad as old’ with probability q. Imperfect repairs are performed following failures occurring between consecutive

preventive maintenance actions, i.e the times between failures follow a decreasing quasi-renewal process with parameter a. Considering the

average durations of the preventive and corrective maintenance actions a

... Show More
View Publication Preview PDF
Crossref
Publication Date
Thu Feb 01 2024
Journal Name
Baghdad Science Journal
Predict the Laser Power and Recovery Period in Treatment by Endovenous Laser Ablation (EVLA)
...Show More Authors

            Eight patients (3 male and 5 female) were treated in this study by Endovenous Laser Ablation (EVLA); Mathematical models are proposed to estimate the applied laser power and to assess the recovery period. The estimations of the applied laser power and recovery period in these models will be depended mainly on the diameter of the incompetent vein.  In addition, Excel Program was utilized to find the proposed models.  A 1470 nm diode laser up to 15W continuous power (CW) was used in the treatment of venous ulcers by EVLA procedure. Following up by duplex ultrasound was started in the 1st week after the first session until the vein is completely closed. The present study concluded that the relationship both between

... Show More
View Publication Preview PDF
Scopus Crossref