Preferred Language
Articles
/
joe-2986
EXPERIMENTAL INVESTIGATION OF LAMINAR NATURAL CONVECTION HEAT TRANSFER IN A RECTANGULAR ENCLOSURE WITH AND WITHOUT INSIDE PARTITIONS

Experimental study has been conducted for laminar natural convection heat transfer of air flow through a rectangular enclosure fitted with vertical partition. The partition was oriented parallel to the two vertical isothermal walls with different temperatures, while all the other surfaces of the enclosure were insulated. In this study a test rig has been designed and constructed to allow studying the effect of Rayleigh number, aperture height ratio, partition thickness, the position of aperture according to the side walls and according to the height, the position of the partition according to the hot wall, and partition inclination. The experiments were carried out with air as the working fluid for Rayleigh number range (5*107 – 1.3*108) and aspect ratio of (0.5). 22 different configurations of partition were used in this study these are:
a) Undivided enclosure (no – partition).
b) (21) Cork partitions of different shapes.
Empirical correlations for average Nusselt number are obtained for the different cases tested. The results show that heat transfer is independent on the partition position according to the cold wall and according to the upper or lower walls, while it shows that heat transfer is sensitive to:
1. Rayleigh number (Ra), which increase with increasing Ra.
2. Aperture height ratio (Ap=hp/H), which is found that when Ap= 5/6 (case 2,3), the reduction in heat transfer is 10.3%, while when Ap=1/2 (case 4,5), the reduction is 17.2% compared with the non partitioned enclosure.
3. Aperture position according to the height, which is found that when the aperture at the centre of the partition (case 13), the reduction in heat transfer is 16.7%, while when the aperture displaced to the upper surface (case 14), the reduction is 19% compared with the non partitioned enclosure.
4. Partition thickness (t), which is found that when t = 10 mm (case 4,5) the reduction in heat transfer is 17.2%, while when t = 150 mm (case 16) the reduction is 20.5% compared with the non partitioned enclosure.
5. Partition inclination (), which is found that the rate of heat transfer reduced with increasingas shown:
a. For = 30 toward the cold wall (case 22), the reduction in heat transfer is 18.2%.
b. For = 45 toward the cold wall (case 18), the reduction in heat transfer was 21.9%.
c. For = 60 toward the cold wall (case 20), the reduction in heat transfer is 30.2%.
d. For = 30 toward the hot wall (case 21), the reduction in heat transfer is 31.3%.
e. For = 45 toward the hot wall (case 17), the reduction in heat transfer is 40.7%.

f. For = 60 toward the hot wall (case 19), the reduction in heat transfer is 42.1%.

Crossref
View Publication Preview PDF
Quick Preview PDF
Publication Date
Sun Nov 26 2017
Journal Name
Journal Of Engineering
Experimental Investigation of Nano Alumina and Nano Silica on Strength and Consistency of Oil Well Cement

In oil and gas well cementing, a strong cement sheath is wanted to insure long-term safety of the wells. Successful completion of cementing job has become more complex, as drilling is being done in highly deviated and high pressure-high temperature wells. Use of nano materials in enhanced oil recovery, drilling fluid, oil well cementing and other applications is being investigated. This study is an attempt to investigate the effect of nano materials on oil well cement properties. Two types of nano materials were investigated, which are Nano silica (>40 nm) and Nano Alumina (80 nm) and high sulfate-resistant glass G cement is used. The investigated properties of oil well cement included compressive strength, thickening

... Show More
View Publication Preview PDF
Publication Date
Tue Jul 02 2019
Journal Name
Fibers
Experimental Investigation of the Behavior of Self-Form Segmental Concrete Masonry Arches

This research aims to introduce a new technique-off-site and self-form segmental concrete masonry arches fabrication, without the need of construction formwork or centering. The innovative construction method in the current study encompasses two construction materials forms the self-form masonry arches, wedge-shape plain concrete voussoirs, and carbon fiber-reinforced polymer (CFRP) composites. The employment of CFRP fabrics was for two main reasons: bonding the voussoirs and forming the masonry arches. In addition, CFRP proved to be efficient for strengthening the extrados of the arch rings under service loadings. An experimental test was conducted on four sophisticated masonry arch specimens. The research parameters were the Keystone thic

... Show More
Scopus (15)
Crossref (10)
Scopus Clarivate Crossref
View Publication Preview PDF
Publication Date
Tue Jan 01 2008
Journal Name
J Bagh College Of Dentistry
A comparative study of the sealing ability of two different obturation techniques with and without the use of sealers.

Background: The final stage of endodontic therapy is complete obturation of the root canal system to provide as perfect as possible at the cementodentinal junction of the apical foramen. The purpose of this in vitro study was to evaluate the sealing ability of injection molded thermoplasticized gutta percha and lateral condensation techniques with and without the use of sealers. Materials and Methods: Forty freshly extracted adult human maxillary central incisors with complete formed apices were utilized in this study. The teeth were randomly divided into four groups for evaluation of the apical seal. Group (1) lateral condensation gutta percha technique without sealer, (2) lateral condensation gutta percha technique with sealer, (3) Inject

... Show More
View Publication Preview PDF
Publication Date
Wed Nov 20 2024
Journal Name
Philosophy Journal
View Publication
Publication Date
Fri Sep 30 2016
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Sorption of Nitrate Salts from Wastewater without and with Modification Orange Peel

This investigation deals with the use of orange peel (OP) waste as adsorbent for removal of nitrate (NO3) from simulated wastewater. Orange peel prepared in two conditions dried at 60C° (OPD) and burning at 500 °C (OPB). The effect of pH: 2-10, contact time: 30- 180 min, sorbent weight: 0.5- 3.0 g were considered. The optimal pH value for NO3 adsorption was found to be 2.0 for both adsorbents. The equilibrium data were analyzed using Langmuir and  Freundlich isotherm models. Freundlich model was found to fit the equilibrium data very well with high-correlation coefficient (R2). The adsorption kinetics was found to follow pseudo-second-order rate kinetic model, with a good correlation (R2

... Show More
View Publication Preview PDF
Publication Date
Sat Sep 02 2017
Journal Name
International Journal Of Science And Research (ijsr)
Publication Date
Fri Jan 20 2023
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Experimental Investigation on Adsorption of Methyl orange Using eggshells as adsorbent Surface

The role of residues in the adsorption process for removing contaminants from their aqueous solution was highlighted in this study. The adsorption capacity of eggshells were used to remove the methyl orange dye from its aqueous solution. The highest dye adsorption was found to range between (62.30% to 62.33%). The results of using adsorption isotherms (Freundlich, Langmuir, and Temkin) have been revealed that the Freundlich model was followed and that the Langmuir model did not match, as well as the partial applicability of Temkin's model at temperatures (298,308,318) K. The process of adsorption is a physical one. Three kinetic models of the adsorption process were also used, with the results demonstrating the applicability of the pseud

... Show More
Crossref (2)
Crossref
View Publication Preview PDF
Publication Date
Wed Oct 01 2014
Journal Name
Iosr Journal Of Mathematics
Flow through an Oscillating Rectangular Duct for Generalized Oldroyd-B Fluid with Fractional Derivatives

The analytic solution for the unsteady flow of generalized Oldroyd- B fluid on oscillating rectangular duct is studied. In the absence of the frequency of oscillations, we obtain the problem for the flow of generalized Oldroyd- B fluid in a duct of rectangular cross- section moving parallel to its length. The problem is solved by applying the double finite Fourier sine and discrete Laplace transforms. The solutions for the generalized Maxwell fluids and the ordinary Maxwell fluid appear as limiting cases of the solutions obtained here. Finally, the effect of material parameters on the velocity profile spotlighted by means of the graphical illustrations

View Publication
Publication Date
Thu May 28 2020
Journal Name
Iraqi Journal Of Science
Evaluation of Serum Clusterin Levels in Type 2 Diabetic Men with and without Cardiovascular Disease

Objectives: The objective of this study was to evaluate serum levels of clusterin (CLU) in type 2 diabetics with and without cardiovascular disease and to explore possible correlations with insulin resistance and related progression of cardiovascular disease in Iraqi men.

Methods: Sixty-three T2DM patients, including forty-two with cardiovascular disease (CVD), were divided into three subgroups; twenty-one with myocardial infraction (MI), twenty-one with other CVD, and twenty-one without any cardiac complication. In addition, a group of twenty-one men served as healthy controls (HCs) for comparison purposes. The four groups were analyzed for parameters that included fasting serum glucose (FSG), l

... Show More
Scopus (4)
Scopus Crossref
View Publication Preview PDF
Publication Date
Thu Oct 01 2015
Journal Name
Journal Of The Faculty Of Medicine Baghdad
Serum Osteocalcin and Serum Osteopontin Levels in Osteoporotic Postmenopausal Women with and without Vertebral Fractures

Background: Osteoporosis is a progressive systemic skeletal disorder characterized by low bone mass and micro-architectural deterioration of bone tissue spatially in postmenopausal women and its major complication fractures.
Objective: The aim of this study was to find out the significance of serum OC and serum OPN levels with the incidence of osteoporosis and its major complication (fractures).
Patients and Methods: Eighty-five postmenopausal women (PMW) whose ages were fifty years and over categorized into three groups: osteoporosis PMW without VFs (n=30), osteoporosis PMW with VFs (n=28), and healthy PMW (n=27). Sera samples were analyzed for alkaline phosphatase, calcium and phosphorous by using spectrophotometric kit. Serum OC

... Show More
Crossref (1)
Crossref
View Publication Preview PDF