Preferred Language
Articles
/
BIbl0YYBIXToZYALYbWz
Natural Convection Effect on Solidification Enhancement in a Multi-Tube Latent Heat Storage System: Effect of Tubes’ Arrangement
...Show More Authors

The solidification process in a multi-tube latent heat energy system is affected by the natural convection and the arrangement of heat exchanger tubes, which changes the buoyancy effect as well. In the current work, the effect of the arrangement of the tubes in a multi-tube heat exchanger was examined during the solidification process with the focus on the natural convection effects inside the phase change material (PCM). The behavior of the system was numerically analyzed using liquid fraction and energy released, as well as temperature, velocity and streamline profiles for different studied cases. The arrangement of the tubes, considering seven pipes in the symmetrical condition, are assumed at different positions in the system, including uniform distribution of the tubes as well as non-uniform distribution, i.e., tubes concentrated at the bottom, middle and the top of the PCM shell. The model was first validated compared with previous experimental work from the literature. The results show that the heat rate removal from the PCM after 16 h was 52.89 W (max) and 14.85 W (min) for the cases of uniform tube distribution and tubes concentrated at the bottom, respectively, for the proposed dimensions of the heat exchanger. The heat rate removal of the system with uniform tube distribution increases when the distance between the tubes and top of the shell reduces, and increased equal to 68.75 W due to natural convection effect. The heat release rate also reduces by increasing the temperature the tubes. The heat removal rate increases by 7.5%, and 23.7% when the temperature increases from 10 °C to 15 °C and 20 °C, respectively. This paper reveals that specific consideration to the arrangement of the tubes should be made to enhance the heat recovery process attending natural convection effects in phase change heat storage systems.

Scopus Clarivate Crossref
View Publication
Publication Date
Wed May 17 2023
Journal Name
Journal Of Engineering
Effect of Metakaolin on Properties of Lightweight Porcelinate Aggregate Concrete
...Show More Authors

Research in Iraq has expanded in the field of material technology involving the properties of the lightweight concrete using natural aggregate. The use of the porcelinate aggregate in the production of structural light concrete has a wide objective
and requires a lot of research to become suitable for practical application. In this work metakaolin was used to improve compressive strength of lightweight porcelinate concrete which usually have a low compressive strength about 17 MPa . The effect of metakaolin on compressive, splitting tensile, flexure strengths and modulus of elasticity of lightweight porcelinate concrete have been investigated. Many experiments were carried out by replacing cement with different percentages of
met

... Show More
View Publication Preview PDF
Crossref (8)
Crossref
Publication Date
Wed Mar 01 2023
Journal Name
Journal Of Transportation Engineering
Effect of nanomaterials on the durability of hot mix asphalt
...Show More Authors

View Publication Preview PDF
Scopus (27)
Crossref (21)
Scopus Crossref
Publication Date
Wed Jan 01 2025
Journal Name
Journal Of Engineering
Effect of Filler Types on Moisture Damage of Asphalt Mixtures
...Show More Authors

The filler in the asphalt mixture is essential since it plays a significant role in toughening and stiffening the asphalt. Changes in filler type can lead the asphalt mixtures to perform satisfactorily during their design life or degrade rapidly when traffic and environmental effects are considered. This study aims to assess the impact of filler types such as limestone dust (LS) and hydrated lime (HL) on Marshall characteristics and moisture damage in asphalt mixtures. Three different percentages of HL were employed in this study to partially replace the LS mineral filler: 1.5, 2.0, and 2.5% by aggregate weight. Furthermore, a control mixture was created with 7% LS by overall aggregate weight for the wearing course layer. The Marsha

... Show More
View Publication
Crossref
Publication Date
Sun May 01 2022
Journal Name
Journal Of Ovonic Research
Effect of antimony on characteristics of HgBa2CaCu2-xSbxO8+δ superconducting
...Show More Authors

In this work, HgBa2CaCu2-xSbxO8+δ compounds with (x = 0.2, 0.4, 0.6 and 0.8) have been prepared by the solid-state reaction method. Structural, morphological, and electrical properties were investigated using X-ray diffraction (XRD) and scanning electron microscope (SEM) techniques. Using the 4-probe technique to study the effect of antimony-substitution for Copper on the electrical properties of HgBa2CaCu2-xSbxO8+δ (Hg-1212) phase was investigated by measuring the resistivity as a function of temperature. Results indicate that the addition of antimony (Sb) increases the volume fraction of the phase and changes the superconducting transition temperature Tc of the superconductor to a normal state. The dielectric loss factor and ac

... Show More
View Publication
Scopus (4)
Crossref (3)
Scopus Clarivate Crossref
Publication Date
Mon Jun 30 2008
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Effect of Operating Cconditions on Hydrodesulfurization of Vacuum Gas Oil
...Show More Authors

This study was conducted according to contract with the North Refineries Company-Baiji and deals with the hydrodesulphurization of vacuum gas oil of Kirkuk crude oil, boiling range 611-833 K. A trickle bed reactor packed with a commercial cobalt-molybdenum on alumina catalyst was used. The operating conditions were: temperature range 583-643 K, liquid hourly space velocity range 1.50-3.75 1/h, hydrogen to oil ratio about 250 l/l and pressure kept constant at 3.5MPa.
The results showed that the aromatic content decreased and sulfur removal increased with increasing temperature and decreasing space velocity. The properties (viscosity, density, flash point and carbon residue) of the products decrease with temperature increasing, but the

... Show More
View Publication Preview PDF
Publication Date
Tue Dec 01 2015
Journal Name
Journal Of Engineering
Effect of Metakaolin on the geotechnical properties of Expansive Soil
...Show More Authors

Expansive soil spreads in Iraq and some countries of the world. But there are many problems can be occurred to the structures that built on, so we must study the characteristics of these soils due to the  problems that may be caused to these structures which built on these kinds of soil and then study the methods of treatment. The present study focuses on improving  the geotechnical properties of expansive soils by treating it Metakaolin(M). Metakaolin (M) has never been used before as an improvement material  for stabilizing the expansive soil . Metakaolin  is a pozzolanic material. It’s obtained by calcination of kaolinite clay at temperatures from 700°C to 800°C. Kaolin chemical composition is

... Show More
View Publication Preview PDF
Publication Date
Sun Apr 01 2007
Journal Name
Journal Of Engineering
Effect of Prestressing Force on Torsion Resistance of Concrete Beams
...Show More Authors

Publication Date
Sat Oct 01 2016
Journal Name
World Journal Of Pharmaceutical Research
EFFECT OF LEVETIRACETAM ON THE CEREBRAL CORTEX OF NEWBORN RAT
...Show More Authors

Background: Levetiracetam is a member of the new antiepileptic drugs and has a broad spectrum effect, used as an adjunctive therapy in addition to monotherapy in the treatment of partial onset-seizures. The effect of levetiracetam on the development of embryo nervous system after maternal exposure during pregnancy has not been identified. Objective: to evaluate the effect of antiepileptic drug, levetiracetam (LEV) within its therapeutic dose 350mg/Kg body weight on albino female rat to clarify its effect on the developing cerebral cortex histologically. Material And Methods: Ten pregnant female rats were separated into two groups, control group and experimental group. They were obtained from the animal house of the high institute of inferti

... Show More
Publication Date
Sun Jan 01 2023
Journal Name
Brazilian Dental Science
Wound healing effect of a one-week Aloe Vera mouthwash: a pilot study
...Show More Authors

View Publication
Scopus (3)
Crossref (1)
Scopus Crossref
Publication Date
Mon Nov 06 2023
Journal Name
Communications In Mathematical Biology And Neuroscience
Effect of hunting cooperation and fear in a food chain model with intraspecific competition
...Show More Authors

Taking into account the significance of food chains in the environment, it demonstrates the interdependence of all living things and has economic implications for people. Hunting cooperation, fear, and intraspecific competition are all included in a food chain model that has been developed and researched. The study tries to comprehend how these elements affect the behavior of species along the food chain. We first examined the suggested model's solution properties before calculating every potential equilibrium point and examining the stability and bifurcation nearby. We have identified the factors that guarantee the global stability of the positive equilibrium point using the geometric approach. Additionally, the circumstances that would gu

... Show More
View Publication Preview PDF
Scopus (7)
Scopus Clarivate Crossref