Preferred Language
Articles
/
N4aqY4YBIXToZYALS4mC
Mixed Convection in a Square Cavity Filled with Porous Medium with Bottom Wall Periodic Boundary Condition
...Show More Authors

Transient mixed convection heat transfer in a confined porous medium heated at periodic sinusoidal heat flux is investigated numerically in the present paper. The Poisson-type pressure equation, resulted from the substituting of the momentum Darcy equation in the continuity equation, was discretized by using finite volume technique. The energy equation was solved by a fully implicit control volume-based finite difference formulation for the diffusion terms with the use of the quadratic upstream interpolation for convective kinetics scheme to discretize the convective terms and the temperature values at the control volume faces. The numerical study covers a range of the hydrostatic pressure head , , , , and ), sinusoidal amplitude range of ⁄ and time period values of ( ) . Numerical results show that the pressure contours lines are influenced by hydrostatic head variation and not affected with the sinusoidal amplitude and time period variation. It is found that the average Nusselt number decreases with time and pressure head increasing and decreases periodically with time and amplitude increasing. The time averaged Nusselt number decreases with imposed sinusoidal amplitude and cycle time period increasing

Preview PDF
Quick Preview PDF
Publication Date
Wed May 29 2019
Journal Name
Iraqi Journal Of Physics
Synthesis and characterization of Iron tungstate oxide films by advanced controlled spray pyrolysis technique
...Show More Authors

For the first time Iron tungstate semiconductor oxides films (FeWO4) was successfully synthesized simply by advanced controlled chemical spray pyrolysis technique, via employed double nozzle instead of single nozzle using tungstic acid and iron nitrate solutions at three different compositions and spray separately at same time on heated silicone (n-type) substrate at 600 °C, followed by annealing treatment for one hour at 500 °C. The crystal structure, microstructure and morphology properties of prepared films were studied by X-ray diffraction analysis (XRD), electron Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM) respectively. According to characterization techniques, a material of well-crystallized monoclinic ph

... Show More
View Publication Preview PDF
Crossref
Publication Date
Wed May 03 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Repeated Corrected Simpson's 3/8 Quadrature Method for Solving Fredholm Linear Integral Equations of the Second Kind
...Show More Authors

  In this paper, we use the repeated corrected Simpson's 3/8 quadrature method for obtaining the numerical solutions of Fredholm linear integral equations of the second kind. This method is more accurately than the repeated corrected Trapezoidal method and the repeated Simpson's 3/8 method. To illustrate the accuracy of this method, we give a numerical example

View Publication Preview PDF
Publication Date
Tue Aug 03 2021
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
New Travelling Wave Solution of Burgers Equations
...Show More Authors

     In this paper, we studied the travelling wave solving for some models of Burger's equations. We used sine-cosine method to solution nonlinear equation and we used direct solution after getting travelling wave equation.

View Publication Preview PDF
Crossref
Publication Date
Sun Aug 01 2021
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Novel Heuristic Approach for Solving Multi-objective Scheduling Problems
...Show More Authors

    In this paper, we studied the scheduling of  jobs on a single machine.  Each of n jobs is to be processed without interruption and becomes available for processing at time zero. The objective is to find a processing order of the jobs, minimizing the sum of maximum earliness and maximum tardiness. This problem is to minimize the earliness and tardiness values, so this model is equivalent to the just-in-time production system. Our lower bound depended on the decomposition of the problem into two subprograms. We presented a novel heuristic approach to find a near-optimal solution for the problem. This approach depends on finding efficient solutions for two problems. The first problem is minimizing total completi

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sun May 17 2020
Journal Name
Iraqi Journal Of Science
Solving Fuzzy Differential Equations by Using Power Series
...Show More Authors

In this paper, the series solution is applied to solve third order fuzzy differential equations with a fuzzy initial value. The proposed method applies Taylor expansion in solving the system and the approximate solution of the problem which is calculated in the form of a rapid convergent series; some definitions and theorems are reviewed as a basis in solving fuzzy differential equations. An example is applied to illustrate the proposed technical accuracy. Also, a comparison between the obtained results is made, in addition to the application of the crisp solution, when the-level equals one.

View Publication Preview PDF
Scopus (1)
Scopus Crossref
Publication Date
Sun Mar 01 2009
Journal Name
Journal Of Economics And Administrative Sciences
Use the method of parsing anomalous valueIn estimating the character parameter
...Show More Authors

In this paper the method of singular value decomposition  is used to estimate the ridge parameter of ridge regression estimator which is an alternative to ordinary least squares estimator when the general linear regression model suffer from near multicollinearity.

View Publication Preview PDF
Crossref
Publication Date
Tue Jan 30 2024
Journal Name
Iraqi Journal Of Science
The Effect of Doped TiO2 Layer on the Performance and Stability of PCDTBT: PCBM-based Organic Solar Cells
...Show More Authors

     Charge extraction layers play a crucial role in developing the performance of the inverted organic solar cells. Using a transparent metal oxide with appropriate work function to the photoactive layer can significantly decrease interface recombination and enhance charge transport mechanism. Therefore, electron selective films that consist of aluminium-doped titanium dioxide (TiO2:Al) with different concentrations of Al (0.4, 0.8, and 1.2)wt %  were prepared using sol-gel technique. The inverted organic solar cells PCPDTBT: PCBM with Al doped TiO2 as electron extraction layer were fabricated. It is well known that Al doping concentration potentially affects the physical characteristics of the TiO2 by control

... Show More
View Publication Preview PDF
Scopus (1)
Scopus Crossref
Publication Date
Sat Jun 27 2020
Journal Name
Iraqi Journal Of Science
On Analytical Solution of Time-Fractional Type Model of the Fisher’s Equation
...Show More Authors

In this paper, the time-fractional Fisher’s equation (TFFE) is considered to exam the analytical solution using the Laplace q-Homotopy analysis method (Lq-HAM)”. The Lq-HAM is a combined form of q-homotopy analysis method (q-HAM) and Laplace transform. The aim of utilizing the Laplace transform is to outdo the shortage that is mainly caused by unfulfilled conditions in the other analytical methods. The results show that the analytical solution converges very rapidly to the exact solution.

View Publication Preview PDF
Scopus (4)
Crossref (1)
Scopus Crossref
Publication Date
Sat Apr 30 2022
Journal Name
Iraqi Journal Of Science
Comparison Different Estimation Method for Reliability Function of Rayleigh Distribution Based On Fuzzy Lifetime Data
...Show More Authors

    In this study, we present different methods of estimating fuzzy reliability of a two-parameter Rayleigh distribution via the maximum likelihood estimator, median first-order statistics estimator, quartile estimator, L-moment estimator, and mixed Thompson-type estimator. The mean-square error MSE as a measurement for comparing the considered methods using simulation through different values for the parameters and unalike sample sizes is used. The results of simulation show that the fuzziness values are better than the real values for all sample sizes, as well as  the fuzzy reliability at the estimation  of the Maximum likelihood Method, and Mixed Thompson Method perform better than the other methods in the sense of MSE, so that

... Show More
View Publication Preview PDF
Scopus (4)
Crossref (2)
Scopus Crossref
Publication Date
Sun Sep 03 2017
Journal Name
Baghdad Science Journal
Sol- Gel Synthesis of Hematite Nanoparticles and Photo Degradation of Cibacron Red FN-R Dye
...Show More Authors

This paper describes the synthesis of ?- Fe2O3 nanoparticles by sol-gel route using carboxylic acid(2-hydroxy benzoic acid) as gelatin media and its photo activity for degradation of cibacron red dye . Hematite samples are synthesized at different temperatures: 400, 500, 600, 700, 800 and 900 ?C at 700 ?C the ?-Fe2O3 nanoparticles are formed with particle size 71.93 nm. The nanoparticles are characterized by XRD , SEM, AFM and FTIR . The 0.046 g /l of the catalyst sample shows high photo activity at 3x10-5M dye concentration in acidic medium at pH 3.

View Publication Preview PDF
Scopus (2)
Scopus Crossref