Preferred Language
Articles
/
joe-2995
DEVELOPING LAMINAR MIXED CONVECTION HEAT TRANSFER THROUGH VERTICAL CONCENTRIC ANNULI WITH ADIABATIC INNER CYLINDER
...Show More Authors

Theoretical and experimental investigations have been carried out on developing laminar
combined free and forced convection heat transfer in a vertical concentric annulus with uniformly
heated outer cylinder (constant heat flux) and adiabatic inner cylinder for both aiding and opposing
flows. The theoretical investigation involved a mathematical modeling and numerical solution for
two dimensional, symmetric, simultaneously developing laminar air flows was achieved. The
governing equations of motion (continuity, momentum and energy) are solved by using implicit
finite difference method and the Gauss elimination technique. The theoretical work covers heat flux
range from (200 to 1500) W/m2, Re range from 400 to 2000 and (1.36×105 ≤ Ra ≤ 1.1×107) with
radius ratio of 0.555 which is the same radius ratio used in the experimental part of this study and
Pr=0.7. The experimental work includes construct a rig consists essentially of an annulus with
uniformly heated outer cylinder and adiabatic inner cylinder to give clear insight into heat transfer
process and compare its results with that obtained in theoretical part, the range of the study are
(Re= 383, 724, 1000, 1500) and heat flux equal to (q =370, 422, 588, 980) W/m2. Numerical results
were represented by the temperature profile, axial velocity profile, outer surface temperature and
the distribution of local Nusselt number along the dimensionless axial distance. The velocity and
temperature profile results have revealed that the secondary flow created by natural convection have
significant effects on the heat transfer process. Results reveal also that the experimental local
Nusselt number along the annulus follows the same trend as present theoretical results with mean
difference 10.23 %.

Crossref
View Publication Preview PDF
Quick Preview PDF
Publication Date
Tue Aug 03 2021
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
The relationship of the investment environment with the indicators of the national economy
...Show More Authors

The investment environment is the incubator for all types of domestic and foreign investments, so if their determinants are encouraging, they increase the levels of investment flows and vice versa, as there is a relationship between the nature of the investment environment and the level of investment flows, and the determinants of the investment environment are numerous and the most important of which are security and political stability, and economic and financial factors that include relative stability In the exchange rate and inflation rates, the availability of banks and their development, transparency and integrity in administrative dealings and the lack of prevalence of administrative and financial corruption, and the clari

... Show More
View Publication Preview PDF
Publication Date
Sun Mar 01 2020
Journal Name
Agricultural Engineering
Analysis of the Vacuum-Steam Defrosting Process of Plums Pre-Treated with Dehydrofreezing
...Show More Authors
Abstract<p>The research material was prune plums (<italic>Prunus domestica</italic> L.), subjected to osmotic pre-treatment, with variable process time parameters and osmotic solution concentration. Plums thus fixed were frozen and stored for 6 months. At even (monthly) intervals, the product was defrosted by the vacuum-steam method, using the s-p-p chamber, until the thermocouple indicated a temperature of 4ºC in the sample’s thermal center. In order to study the kinetics of phenomena occurring during the defrosting process, the chamber was equipped with a measuring system to enable measurement and recording of temperature changes in time in the geometric center of the sample, as w</p> ... Show More
Scopus (1)
Scopus Crossref
Publication Date
Thu Jun 30 2016
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Study the Efficiency of Drilling With Casing Operation in an Iraqi Oil Field
...Show More Authors

Drilling with casing (DWC) can be considered as a modern drilling technique in which both of drilling and casing operations done in the same time by using the casing to transfer the hydraulic and mechanical power to the bit instead of traditional drilling string. To overcome oil well control, minimizing the total cost through enhancing drilling efficiency, drilling with casing was proposed as an enabling technology.

   Two surface sections (17 1/2 - and 12 1/4- inch) were drilled successfully in Rumaila oil field with  casing strings which reached 655m and 1524m measured depths respectively.

   By using DWC technique, the total drill/case phase time was reduced up to 20% comparing to conventional

... Show More
View Publication Preview PDF
Publication Date
Sun Mar 03 2013
Journal Name
Baghdad Science Journal
The Association of Myasthenia Gravis with HLA class II Antigens in Iraqi Patients
...Show More Authors

The nature and intensity of the association of myasthenia gravis (MG) with distinct human leukocyte antigen (HLA) haplotypes differ between ethnic populations, so this study determined the association of HLA class II antigens with myasthenia gravis (MG) in Iraq.The study included Iraqi patients diagnosed with MG and two control groups the first of 54 insulin dependent diabetes mellitus patients and the second of 237 subjects as a normal control group. The test used was microlymphocytotoxicity test.The work was done in the Teaching Laboratories/Medical City/Baghdad.Results: positive associations were observed (etiological risk factors) as follows: 1. HLA-DR locus showed one positively associated allele when compared to healthy control and th

... Show More
View Publication Preview PDF
Crossref
Publication Date
Thu Jun 02 2016
Journal Name
Ashrae Transactions
Melting of PCM with nanoparticles in a triplex-tube thermal energy storage system
...Show More Authors

Scopus (29)
Scopus
Publication Date
Sun Mar 01 2020
Journal Name
Agricultural Engineering
Analysis of the Vacuum-Steam Defrosting Process of Plums Pre-Treated with Dehydrofreezing
...Show More Authors
Abstract<p>The research material was prune plums (<italic>Prunus domestica</italic> L.), subjected to osmotic pre-treatment, with variable process time parameters and osmotic solution concentration. Plums thus fixed were frozen and stored for 6 months. At even (monthly) intervals, the product was defrosted by the vacuum-steam method, using the s-p-p chamber, until the thermocouple indicated a temperature of 4ºC in the sample’s thermal center. In order to study the kinetics of phenomena occurring during the defrosting process, the chamber was equipped with a measuring system to enable measurement and recording of temperature changes in time in the geometric center of the sample, as w</p> ... Show More
View Publication
Scopus (1)
Scopus Crossref
Publication Date
Tue Aug 22 2017
Journal Name
Heat Transfer—asian Research
Thermal Enhancement from Pin Fins by Using Elliptical Perforations with Different Inclination Angles
...Show More Authors
Abstract<p>Many of the proposed methods introduce the perforated fin with the straight direction to improve the thermal performance of the heat sink. The innovative form of the perforated fin (with inclination angles) was considered. Present rectangular pin fins consist of elliptical perforations with two models and two cases. The signum function is used for modeling the opposite and the mutable approach of the heat transfer area. To find the general solution, the degenerate hypergeometric equation was used as a new derivative method and then solved by Kummer's series. Two validation methods (previous work and Ansys 16.0‐Steady State Thermal) are considered. The strong agreement of the validation results (0.3</p> ... Show More
View Publication
Scopus (4)
Crossref (5)
Scopus Crossref
Publication Date
Sat Dec 30 2017
Journal Name
International Journal Of Heat And Technology
Optimization of a rectangular pin fin using rectangular perforations with different inclination angles
...Show More Authors

View Publication
Scopus (6)
Crossref (3)
Scopus Crossref
Publication Date
Tue Jul 10 2018
Journal Name
Journal Of Global Pharma Technology
Synthesis, Spectral Studies and Biological Activity of Azo dye Complexes with Some MetalIons
...Show More Authors

2-(2-amino-5-nitro-phenylazo),-phenol was ready by grouping the diazonium salt of 2-aminophenol with 4-nitroaniline.Thegeometry of azo ligand(HL)was resolved on the origin of (C.H.N) analysis,1H and 13CNMR spectra, infrared spectra and UV–vis electronic absorption spectra. Dealing with the azo ligand produced with Rh+3 and La+3ataqueous ethanol for a 1:3 metal: ligand rate, and in perfect ph. The formation for compounds have been described by utilizing flame atomic, absorption,(C.H.N),Analyses, conductivity, infrared spectra and UV–vis spectral procedures. Nature in the produced compounds, have been studied, obey the ratio of mole and continuous, variance, manners, Beer's law, yielded up a concentration, rate (1×10-4- 3×10-4M),. High

... Show More
Preview PDF
Publication Date
Tue Feb 17 2026
Journal Name
Iraqi Journal Of Agricultural Sciences
EFFECT OF TILLAGE WITH CHISEL PLOW ON SOIL MEAN WEIGHT DIAMETER AND POROSITY
...Show More Authors

View Publication