Preferred Language
Articles
/
lRfweY4BVTCNdQwC-EnE
Investigation of phase change characteristics for refrigerant R-134a flow in a double pipe heat exchanger with the use of thermal non-equilibrium model
...Show More Authors

Almost all thermal systems utilize some type of heat exchanger. In a lot of cases, evaporators are important for systems like organic Rankine cycle systems. Evaporators give a share in a large portion of the capital cost, and their cost is significantly attached to their size or transfer area. Open-cell metal foams with high porosity are taken into consideration to enhance thermal performance without increase the size of heat exchangers. Numerous researchers have tried to find a representation of the temperature distribution closer to reality due to the different properties between the liquid and solid phases. Evaporation heat transfer in an annular pipe of double pipe heat exchanger (DPHEX) filled with cooper foam is investigated numerically with utilizing the local thermal non-equilibrium (LTNE) model. Warm water with constant inlet conditions flows in the inner pipe while R143a is used as cooling fluid in the annular pipe. The effects of pores per inch (PPI), mass flux of R134a and copper foam porosity on solid and fluid temperatures, liquid saturation and heat transfer coefficient are analysed and illustrated. Forchheimer-extended Darcy flow model is utilized with the adopting of the two-phase mixture model (TPMM). The governing equations in two-dimensional steady state regime were written in LTNE model. These equations were discretized using the finite volume method and a MATLAB program was built to solve these equations with its initial and boundary conditions. The obtained data illustrates that LTNE effect in metal foam is important for lower porosity, lower pore density and higher mass flux. The ratio of liquid will arrive its lowest value at the outlet, and it decreases with PPI increase and it increases with porosity and mass flux increase. The mean heat transfer coefficient approximately doubled when PPI increased from 10 to 50 and it increased by 70% when porosity decreased from 0.95 to 0.85.

Scopus Crossref
View Publication Preview PDF
Quick Preview PDF
Publication Date
Thu Dec 01 2022
Journal Name
Bulletin Of Electrical Engineering And Informatics
A model for incorporating suitable methods of usability evaluation into agile software development
...Show More Authors

The challenge to incorporate usability evaluation values and practices into agile development process is not only persisting but also systemic. Notable contributions of researchers have attempted to isolate and close the gaps between both fields, with the aim of developing usable software. Due to the current absence of a reference model that specifies where and how usability activities need to be considered in the agile development process. This paper proposes a model for identifying appropriate usability evaluation methods alongside the agile development process. By using this model, the development team can apply usability evaluations at the right time at the right place to get the necessary feedback from the end-user. Verificatio

... Show More
View Publication
Scopus (3)
Scopus Crossref
Publication Date
Sun Dec 01 2002
Journal Name
Iraqi Journal Of Physics
A Hyperbolic Potential Field Model for Designing an Einzel Lens of Low Aberrations
...Show More Authors

An analytical model in the form of a hyperbolic function has been suggested for the axial potential distribution of an electrostatic einzel lens. With the aid of this hyperbolic model the relative optical parameters have been computed and investigated in detail as a function of the electrodes voltage ratio for various trajectories of an accelerated charged-particles beam. The electrodes voltage ratio covered a wide range where the lens may be operated at accelerating and decelerating modes. The results have shown that the proposed hyperbolic field has the advantages of producing low aberrations under various magnification conditions and operational modes. The electrodes profile and their three-dimensional diagram have been determined whi

... Show More
View Publication Preview PDF
Publication Date
Fri May 30 2014
Journal Name
Applied Surface Science
Liquid Phase - Pulsed Laser Ablation: A route to fabricate different carbon nanostructures
...Show More Authors

Scopus (57)
Scopus
Publication Date
Wed Oct 17 2018
Journal Name
Journal Of Economics And Administrative Sciences
A Comparison of Bayes Estimators for the parameter of Rayleigh Distribution with Simulation
...Show More Authors

   A comparison of double informative and non- informative priors assumed for the parameter of Rayleigh distribution is considered. Three different sets of double priors are included, for a single unknown parameter of Rayleigh distribution. We have assumed three double priors: the square root inverted gamma (SRIG) - the natural conjugate family of priors distribution, the square root inverted gamma – the non-informative distribution, and the natural conjugate family of priors - the non-informative distribution as double priors .The data is generating form three cases from Rayleigh distribution for different samples sizes (small, medium, and large). And Bayes estimators for the parameter is derived under a squared erro

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sun Aug 17 2025
Journal Name
Journal Of Baghdad College Of Dentistry
Study of salivary IgA concentrations, salivary flow rate in patients with β –thalassemia major in Missan Governorate
...Show More Authors

Background: Beta-thalassemia major is the most common monogenic known disorder in the Middle East, characterized by anomalies in the synthesis of the beta chains of hemoglobin resulting in variable phenotypes ranging from severe anemia to clinically asymptomatic Individuals. This study aimed to evaluate salivary flow rate and salivary IgA in β-thalassemia major patients. Since many oral and systemic conditions manifest themselves as changes in the flow and composition of saliva the dental practitioner is advised to remain up-to-date with this issue. Materials and methods: The study samples consist of (60) subjects, patients group composed of (30) patients with β –thalassemia major, age rang (5-23) years and (30) healthy locking

... Show More
View Publication Preview PDF
Publication Date
Mon Jan 20 2020
Journal Name
Kuwait Journal Of Science
Three iterative methods for solving Jeffery-Hamel flow problem
...Show More Authors

In this article, the nonlinear problem of Jeffery-Hamel flow has been solved analytically and numerically by using reliable iterative and numerical methods. The approximate solutions obtained by using the Daftardar-Jafari method namely (DJM), Temimi-Ansari method namely (TAM) and Banach contraction method namely (BCM). The obtained solutions are discussed numerically, in comparison with other numerical solutions obtained from the fourth order Runge-Kutta (RK4), Euler and previous analytic methods available in literature. In addition, the convergence of the proposed methods is given based on the Banach fixed point theorem. The results reveal that the presented methods are reliable, effective and applicable to solve other nonlinear problems.

... Show More
View Publication Preview PDF
Publication Date
Mon Mar 25 2019
Journal Name
Al-academy
The Use of Arabic Calligraphy Items in Decorative Designs for Islamic Fabrics and Costumes: الهام طاهر حسين
...Show More Authors

The Arabic calligraphy, in the early days of Islam, was used for the purpose of decorating the walls of mosques from inside and outside. Hence, this decorative art must be actively involved in enriching the designs of Islamic fabrics and costumes because it has a highly qualified and aesthetically pleasing look and expresses the originality of the Arab spirit. The research is divided into two section: the first section included the following topics: First "A historical overview of the art of decoration in Islamic Arab thought". Second "linear formations of decorative designs, and the subject of intellectual aesthetic taste of the art of decorating. This section tackles two subsections: first "the beauty of thought between the function an

... Show More
View Publication Preview PDF
Crossref
Publication Date
Mon Mar 11 2019
Journal Name
Al-khwarizmi Engineering Journal
An Investigation Study of Tool Geometry in Single Point Incremental Forming (SPIF) and their effect on Residual Stresses Using ANOVA Model
...Show More Authors

Incremental forming is a flexible sheet metal forming process which is performed by utilizing simple tools to locally deform a sheet of metal along a predefined tool path without using of dies. This work presents the single point incremental forming process for producing pyramid geometry and studies the effect of tool geometry, tool diameter, and spindle speed on the residual stresses. The residual stresses were measured by ORIONRKS 6000 test measuring instrument. This instrument was used with four angles of (0º,15º,30º, and 45º) and the average value of residual stresses was determined, the value of the residual stress in the original blanks was (10.626 MPa). The X-ray diffraction technology was used to measure the residual stresses

... Show More
View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Sun May 01 2022
Journal Name
Civil Engineering Journal
Phases of Urban Development Impact on the Assessment of Thermal Comfort: A Comparative Environmental Study
...Show More Authors

Millions of pilgrims and visitors from numerous parts of the world flock to Karbala (one of the most prominent ideological and religious places in central Iraq) each year to visit the holy shrines in Karbala due to their sanctity. Many improvements have been made to the Two Holy Shrines (THS), the Shrines of Imam Husayn and Imam Abbas, and the area between them (ATHS), due to the high temperatures in this region and to improve pedestrian thermal comfort. Studies on improving outdoor thermal comfort in Karbala are scarce. Hence, this research aims to look into historical and current architectural changes and how they affect thermal comfort. On the hottest summer day, the ENVI-met software program was used to simulate the building des

... Show More
View Publication
Scopus (15)
Crossref (13)
Scopus Clarivate Crossref
Publication Date
Sun May 01 2022
Journal Name
Civil Engineering Journal
Phases of Urban Development Impact on the Assessment of Thermal Comfort: A Comparative Environmental Study
...Show More Authors

Millions of pilgrims and visitors from numerous parts of the world flock to Karbala (one of the most prominent ideological and religious places in central Iraq) each year to visit the holy shrines in Karbala due to their sanctity. Many improvements have been made to the Two Holy Shrines (THS), the Shrines of Imam Husayn and Imam Abbas, and the area between them (ATHS), due to the high temperatures in this region and to improve pedestrian thermal comfort. Studies on improving outdoor thermal comfort in Karbala are scarce. Hence, this research aims to look into historical and current architectural changes and how they affect thermal comfort. On the hottest summer day, the ENVI-met software program was used to simulate the building des

... Show More
View Publication
Crossref (13)
Crossref