Preferred Language
Articles
/
ijs-6704
Numerical Determination of Thermal Conductivity in Heat Equation under Nonlocal Boundary Conditions and Integral as Over specified Condition
...Show More Authors

In this article, an inverse problem of finding timewise-dependent thermal conductivity has been investigated numerically. Numerical solution of forward (direct) problem has been solved by finite-difference method (FDM). Whilst, the inverse (indirect) problem solved iteratively using Lsqnonlin   routine  from MATLAB. Initial guess for unknown coefficient expressed by explicit relation   based on nonlocal overdetermination conditions and intial input data .The obtained numrical results are presented and discussed in several figures and tables. These results are accurate and stable even in the presense of noisy data.

Scopus Crossref
View Publication Preview PDF
Quick Preview PDF
Publication Date
Sun Jul 01 1990
Journal Name
Bulletin Of The Iraq Natural History Museum (p-issn: 1017-8678 , E-issn: 2311-9799)
COMPARISON OF ALFALFA WEEVIL POPULATIONS UNDER EPIZOOTIC AND ENZOOTIC CONDITIONS OF ERYNIAPHYTONOMI IN WISCONSIN
...Show More Authors

Comparisons of two life tables constructed to display alfaifa weevil Hypera posticoa (Gryllenhal), populations in southeentral Wisconsin, U. S. A. under epizootic and enzootic conditions of fungal diseasea, caused by Erynia phytonomi Arthur suggests that the “prepupal” stage provided the greates contribution to population changes under both conditions due to the high mortality rate. The principle mortality agents during this stage are E. phytonomi and the parasitoids complex of Bathyp1ectes curculionis and Buthyp1ectes anurus respectively under the two condition.

View Publication Preview PDF
Publication Date
Mon Mar 08 2021
Journal Name
Baghdad Science Journal
An approximate solution for solving linear system of integral equation with application on "Stiff" problems
...Show More Authors

An approximate solution of the liner system of ntegral cquations fot both fredholm(SFIEs)and Volterra(SIES)types has been derived using taylor series expansion.The solusion is essentailly

View Publication Preview PDF
Publication Date
Mon Jun 01 2020
Journal Name
Journal Of Engineering
Thermal Modeling of Solar Still Coupled with Heat Pipes and Experimental Validation
...Show More Authors

Water is the basis of the existence of all kinds of life, so obtaining it with good quality represents a challenge to human existence and development especially in the desert and remote cities because these areas contain small populations and water purification requires great materials and huge amounts of fossil fuels resulting pollution of the environment. Cheap and environmentally friendly desalination methods have been done by using solar distillations. Passive solar stills have low yields, so in this research, the problem is overcome by connecting four heat pipes which are installed on the parabolic concentrator reflector with passive solar still to increase the temperature of hot water to more than 90°C, as a resul

... Show More
View Publication Preview PDF
Crossref
Publication Date
Wed Mar 30 2022
Journal Name
Iraqi Journal Of Science
Numerical Solution of Linear Fractional Differential Equation with Delay Through Finite Difference Method
...Show More Authors

This article addresses a new numerical method to find a numerical solution of the linear delay differential equation of fractional order , the fractional derivatives described in the Caputo sense. The new approach is to approximating second and third derivatives. A backward finite difference method is used. Besides, the composite Trapezoidal rule is used in the Caputo definition to match the integral term. The accuracy and convergence of the prescribed technique are explained. The results  are shown through numerical examples.

 

View Publication Preview PDF
Scopus (5)
Crossref (3)
Scopus Crossref
Publication Date
Wed Jan 01 2014
Journal Name
Advances In Mechanical Engineering
Experimental and Numerical Investigations of Heat Transfer Characteristics for Impinging Swirl Flow
...Show More Authors

This paper reports experimental and computational fluid dynamics (CFD) modelling studies to investigate the effect of the swirl intensity on the heat transfer characteristics of conventional and swirl impingement air jets at a constant nozzle-to-plate distance ( L = 2 D). The experiments were performed using classical twisted tape inserts in a nozzle jet with three twist ratios ( y = 2.93, 3.91, and 4.89) and Reynolds numbers that varied from 4000 to 16000. The results indicate that the radial uniformity of Nusselt number (Nu) of swirl impingement air jets (SIJ) depended on the values of the swirl intensity and the air Reynolds number. The results also revealed that the SIJ that was fitted with an insert of y = 4.89, which correspo

... Show More
View Publication
Scopus (15)
Crossref (9)
Scopus Clarivate Crossref
Publication Date
Sun Jul 31 2022
Journal Name
Iraqi Journal Of Science
Study of Limestones from the Nfayil Formation in Bahr Al-Najaf Depression and Suitability for Thermal conductivity
...Show More Authors

     The evaluation of the Nfayil limestones in Bahr Al-Najaf Depression as construction materials was done on 15 sites distributed over a region. The study included field and laboratory aspects. The field side included collecting information about the study area and samples. As for the laboratory side, laboratory tests were conducted to study the thermal conductivity of samples by a device called Lee’s disc in the Tikri University. The thermal conductivity results ranged between 2.34 and 0.27. The rocks are of high thermal insulation at low temperatures and low insulation at high temperatures according to the specifications of the suitability of limestone for thermal conductivity standards (ASTM C 1057-03-2010).

View Publication Preview PDF
Scopus (2)
Scopus Crossref
Publication Date
Fri Sep 30 2016
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Thermal and Catalytic Degradation Kinetics of High-Density Polyethylene Over NaX Nano-Zeolite
...Show More Authors

Thermal and catalytic pyrolysis of waste plastics in an inert atmosphere has been regarded as a creative method, since pyrolysis can convert plastics waste into hydrocarbons that can be used either as fuels or as a source of chemicals.

Natural Iraqi kaolin clay was used to synthesis the NaX nano- zeolite by hydrothermal conditions with average particle size equal to 77.63nm.Thermal decomposition kinetics of high-density polyethylene (HDPE) in the absence and presence of catalysts nano NaX Zeolite was investigated. Thermal and catalytic degradation of HDPE was performed using a thermogravimetric analyzer in nitrogen atmosphere under non-isothermal conditions 4, 7 and 10 °C/min heating rates were employed in thermogravimetric anal

... Show More
View Publication Preview PDF
Publication Date
Fri Jan 01 2016
Journal Name
Applied Numerical Mathematics
Multiple time-dependent coefficient identification thermal problems with a free boundary
...Show More Authors

View Publication
Scopus (27)
Crossref (18)
Scopus Clarivate Crossref
Publication Date
Thu Oct 01 2015
Journal Name
Journal Of Engineering
Numerical Simulation of Natural Convection Heat Transfer from Interrupted Rectangular Fins
...Show More Authors

      Numerical simulations have been investigated to study the external free convective heat transfer from a vertically rectangular interrupted fin arrays. The continuity, Naver-Stockes and energy equations have been solved for steady-state, incompressible, two dimensional, laminar with Boussiuesq approximation by Fluent 15 software. The performance of interrupted fins was evaluated to gain the optimum ratio of interrupted length to fin length (

View Publication Preview PDF
Publication Date
Wed Jul 31 2019
Journal Name
Journal Of Engineering
Buckling Analysis of Laminated Composite Plate with Different Boundary Conditions using modified Fourier series
...Show More Authors

Buckling analysis of a laminated composite thin plate with different boundary conditions subjected to in-plane uniform load are studied depending on classical laminated plate theory; analytically using (Rayleigh-Ritz method). Equation of motion of the plates was derived using the principle of virtual work and solved using modified Fourier displacement function that satisfies general edge conditions. The eigenvalue problem generated by using Ritz method, the set of linear algebraic equations can be solved using MATLAB for symmetric and anti-symmetric, cross and angle-ply laminated plate considering some design parameters such as aspect ratios, number of layers, lamination type and orthotropic ratio. The results obtained g

... Show More
View Publication Preview PDF
Crossref (3)
Crossref