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 Mar 12 2020
Journal Name
Al-khwarizmi Engineering Journal
Optimization the Effect of Electrode Material Change on EDM Process Performance Using Taguchi Method
...Show More Authors

Electrical Discharge Machining (EDM) is a widespread Nontraditional Machining (NTM) processes for manufacturing of a complicated geometry or very hard metals parts that are difficult to machine by traditional machining operations. Electrical discharge machining is a material removal (MR) process characterized by using electrical discharge erosion. This paper discusses the optimal parameters of EDM on high-speed steel (HSS) AISI M2 as a workpiece using copper and brass as an electrode. The input parameters used for experimental work are current (10, 24 and 42 A), pulse on time (100, 150 and 200 µs), and pulse off time (4, 12 and 25 µs) that have effect on the material removal rate (MRR), electrode wear rate (EWR) and wear ratio (WR). A

... Show More
View Publication Preview PDF
Publication Date
Thu May 08 2025
Journal Name
Asian Journal Of Advanced Research And Reports
Green Chemistry Strategies to Enhance the Thermal Stability of PVC: A State-of-the-Art Overview on Plant Oil-Derived Stabilizers
...Show More Authors

Polyvinyl chloride (PVC) finds use in various industries due to its versatility but is not thermostable, serving as a barrier to causing degradation and release of hydrochloric acid (HCl) under heat stress conditions. Lead and organotin compounds have traditionally been used for stabilizer purpose to discourage such degradation but pose serious ecological as well as health risks. As a counter measure, bio-based stabilizers from plant oils have become popular as a green and sustainable alternative. This review looks back at recent developments in plant oil-based stabilizers for PVC, focusing on the mechanisms of stabilization, sustainability, and cost-effectiveness. We review plant oils such as tung oil, castor oil, and soybean oil,

... Show More
View Publication
Crossref
Publication Date
Mon Jun 05 2023
Journal Name
Journal Of Engineering
Adsorption of Chromium (Vi) from Aqueous Solutions using Low Cost Adsorbent: Equilibrium and Regeneration Studies
...Show More Authors

The adsorption of Cr (VI) from aqueous solution by spent tea leaves (STL) was studied at different initial Cr (VI) concentrations, adsorbent dose, pH and contact time under batch isotherm experiments The adsorption experiments were carried out at 30°C and the effects of the four parameters on chromium uptake to establish a mathematical model description percentage removal of Cr (VI). The
analysis results showed that the experimental data were adequately fitted to second order polynomial model with correlation coefficients for this model was (R2 = 0.9891). The optimum operating parameters of initial Cr (VI) concentrations, adsorbent dose, pH and contact time were 50 mg/l, 0.7625 g, 3 and 100 min, respectively. At these conditions, th

... Show More
View Publication Preview PDF
Crossref (5)
Crossref
Publication Date
Wed Dec 01 2021
Journal Name
Structures
The effect of ground motion characteristics on the fragility analysis of reinforced concrete frame buildings in Australia
...Show More Authors

View Publication
Crossref (11)
Crossref
Publication Date
Mon May 01 2023
Journal Name
Latin American Journal Of Pharmacy
Irrational Use of Antibiotics in Iraqi Public Hospitals
...Show More Authors

Scopus (5)
Scopus
Publication Date
Tue Dec 01 2020
Journal Name
International Journal Of Research In Pharmaceutical Sciences
Iraqi Experience of Factor VII use in Children
...Show More Authors

Bleeding disorders in pediatrics is an important issue and can be lifethreatening if not diagnosed and treated appropriately. We aimed to evaluate Iraqi pediatric practice (as an example of resource-limited settings) about the use of Recombinant Activated Factor VII (RFVIIa) in bleeding disorders, with emphasis on its effectiveness and safety, in comparison with adjuvant therapy. Budget restrictions may affect the availability of even lifesaving drugs such as (RFVIIa). Therefore, we tried to investigate the local experience of pediatric bleeding, with the evaluation of the potential ability of adjuvant therapy of blood products and vitamin K to substitute RFVIIa in case of non-availability. During a complete one year‘s period, 35 patients

... Show More
Preview PDF
Scopus
Publication Date
Mon May 19 2025
Journal Name
Retos
The effect of the cube model on visual-spatial intelligence and learning the skill of spiking in volleyball for female students
...Show More Authors

Objective: To identify the effect of the cube model on visual-spatial intelligence and learning the skill of spikinging in volleyball for female students, The researchers used the experimental method by designing two equivalent groups with pre- and post-measurements. Research methodology: The main research sample of (30) female students was selected from the research community represented by second-stage students in the College of Physical Education and Sports Sciences - University of Baghdad for the academic year (2024-2025). The sample was divided equally into two control and experimental groups. The researchers conducted the sample homogenization process and the equivalence process between the two groups in the variables of visua

... Show More
View Publication
Scopus Crossref
Publication Date
Sat Sep 01 2007
Journal Name
Al-khwarizmi Engineering Journal
Study of Mechanical Characteristics for Polymer Composite Reinforced by Particles of (Al2O3) or (Al)
...Show More Authors

A particulate polymer composite material was prepared by reinforcing with the Aluminum Oxide (Al2O3) or Aluminum (Al) metallic particles with a particle size of (30) µm to an unsaturated Polyester Resin with a weight fraction of (5%, 10%, 15%, 20%).

Tensile test results showed the maximum value of elastic modulus reached (2400MPa.)  in the case of reinforcing with (Al) particles with weight fraction (20%) and (1500 MPa.)  in the case of reinforcing with (Al2O3) particles of the same weight fraction.

  When the impact and the flexural strength tests were done, the results showed that flexural strength (F.S), maximum shear stress (τmax), impact strength

... Show More
View Publication Preview PDF
Publication Date
Thu Jan 30 2014
Journal Name
Al-kindy College Medical Journal
Managementt o f non traumatic A vascular Necrosis off Femoral Head at precollapse stage with Core Decompression and tibial Bone Grafting
...Show More Authors

 Avascular necrosis have always presented great challenges to orthopedic surgeons and patients, remain in many ways today the unsolved dilemma. Varieties of non-vascularized bone grafting techniques preceded by core decompression have been proposed with varying degrees of success. O bb j ee cc t i vv ee ss : The aim of this study is to review the the value of core decompression and non-vascularized tibial bone strip graft treatment for early stages of non-traumatic osteonecrosis stage II & III according to stein burg staging . M ee t hh oo dd ss : prospectively reviewed 26 patients (32 hips) with osteonecrosis of the femoral head between June 2006 and December 2013 at Imam Ali hospital in Sader city & Al-Wasity teaching hosp

... Show More
View Publication Preview PDF
Publication Date
Thu Feb 07 2019
Journal Name
Journal Of The College Of Education For Women
Double Exile: Jean Rhys's Wide Sargasso Sea
...Show More Authors

The problems of cultural displacement and a shaky sense of one's own identity
have been the main concern of the twentieth century Caribbean writer, Jean Rhys. As
a white Creole writer living in England, Rhys attempts to capture the ambivalence of
what it means to be caught between two cultures and never able to identify fully with
any one .Born to a Welsh father and a Creole(white West Indian) mother on the island
of Dominica in the West Indies, Jean Rhys was white but not English, West Indian but
not black. Her sense of belonging to the West Indies was necessarily charged with
awareness of being part of another culture. Thus, the ambiguity of being an
insider/outsider in both the metropolis, England, and the colo

... Show More
View Publication Preview PDF