Preferred Language
Articles
/
GuYymp0BmraWrQ4d9lq7
NUMERICAL AND EXPERIMENTAL INVESTIGATIONOF STEAM FILM CONDENSATION ON A VERTICAL TUBE
...Show More Authors

 Film condensation of steam on a vertical tube is investigated numerically and experimentally,   in the present work. A mathematical model was set based on the basic conservation laws of mass   and energy, Nusselts analysis of film condensation, and empirical equations available in the   literature. Then, a simulation program in FORTRAN language was developed which simulates the   film condensation of steam on a vertical tube. A complete steam tables subprogram was also   developed and incorporated with the main program. The experimental work was carried out using a   steam condensation test bench. The inlet and outlet cooling water temperatures, steam temperature   and pressure, tube surface temperature at center, and cooling water flow rate are recorded during   each experimental test run. The inlet cooling water temperature, steam temperature, and cooling   water flow rate are used as an input for the numerical program, then the program calculates tube   surface temperature distribution, cooling water temperature distribution, local heat transfer rate,   local condensation heat transfer coefficient, condensate boundary layer thickness distribution, total   heat transfer rate, and average condensation heat transfer coefficient. The effect of various   parameters on the condensation heat transfer coefficient, such as steam temperature, steam-surface   temperature difference, and the presence of non-condensable gas were investigated and reported   graphically. It was found that increasing (steam-surface) temperature difference while keeping the   steam temperature constant results in an increase in condensate boundary layer thickness, which in   turn causes a decrease in condensation heat transfer coefficient. On the other hand, increasing steam   temperature and keeping the (steam-surface) temperature difference constant leads to an increase in   condensation heat transfer coefficient. In addition, the presence of non-condensable gas with   different concentrations was also investigated and it was shown that it causes a noticeable reduction   in the average condensation heat transfer coefficient. An equation for calculating average   condensation heat transfer coefficient on a vertical tube was also developed. The experimental data   obtained from the test runs were compared with numerical results and showed good agreement.   Thus, it can be concluded that the present computational program is suitable for simulating steam   condensation on a vertical tube. 

Crossref
View Publication
Publication Date
Mon Oct 01 2018
Journal Name
Iraqi Journal Of Physics
The effect of gold nanoparticles on WO3 thin film
...Show More Authors

Chemical spray pyrolysis technique was used at substrate temperature 250 ˚C with annealing temperature at 400 ˚C (for 1hour) to deposition tungsten oxide thin film with different doping concentration of Au nanoparticle (0, 10, 20, 30 and 40)% wt. on glass substrate with thickness about 100 nm. The structural, optical properties were investigated. The X-ray diffraction shows that the films at substrate temperature (250 ˚C) was amorphous while at annealing temperature have a polycrystalline structure with the preferred orientation of (200), all the samples have a hexagonal structure for WO3 and Au gold nanoparticles have a cubic structure. Atomic force microscopy (AFM) was used to characterize the morphology of the films. The optical pr

... Show More
View Publication Preview PDF
Crossref (3)
Crossref
Publication Date
Sun Jul 31 2022
Journal Name
Journal Of Ovonic Research
Effect of annealing on thin film AgInSe2 solar cell
...Show More Authors

AgInSe2 (AIS) thin films solar cell involving of n-type AgInSe2 and Si of p-type substrate by using thermal evaporation method. The influence of annealing of the preparation AgInSe2 were considered to find the best properties of solar device. Thin film AIS have been deposited under the vacuum of 1.5*10-6 Torr with (400) nm thickness at R.T and annealing temperatures (473,573) K. Polycrystalline tetragonal structure for AIS thin films from XRD and increasing of surface roughness from AFM, energy gap values decreasing with increasing annealing temperatures, all films were negative type, I-V characteristics show increasing of efficiency with increasing of annealing temperatures.

View Publication
Scopus (7)
Crossref (5)
Scopus Clarivate Crossref
Publication Date
Mon Apr 20 2026
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Preparation and Annealing Effects on the Structural and Optical Properties of ZnTe Thin Film
...Show More Authors

ZnTe possesses the proper optoelectronic properties as a candidate for device development. The structure and optical properties of ZnTe semiconductor thin films of 500 nm were studied using thermal evaporation technique. The influence of annealing temperatures on ZnTe thin films in the range ( R.T - 473 K). XRD and surface morphological analyses are used to examine the films. The ZnTe films are comparatively polycrystalline and cubic in phase, according to the XRD analysis. with a lattice constant of 0.61 nm upon an (111) orientation. The intensities of all the peaks rapidly increase though they show the same tendencies; it shows the crystallinity of the films becomes higher crystal size diameters (from 8.41 to 12.18nm) both increas

... Show More
View Publication
Crossref
Publication Date
Mon Dec 30 2002
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Relationship Between Nusselt and Reynolds Number in Direct Contact Heat Transfer by Condensation of Light Hydrocarbons in Water
...Show More Authors

View Publication Preview PDF
Publication Date
Wed Jun 01 2022
Journal Name
Chalcogenide Letters
Influence of Al dopant on structural and optical parameters of AgInSe2 thin film
...Show More Authors

Chalcopyrite thin films ternary Silver Indium Diselenide AgInSe2 (AIS) pure and Aluminum Al doped with ratio 0.03 was prepared using thermal evaporation with a vacuum of 7*10-6 torr on glass with (400) nm thickness for study the structural and optical properties. X-ray diffraction was used to show the inflance of Al ratio dopant on structural properties. X-ray diffraction show that thin films AIS pure, Al doped at RT and annealing at 573 K are polycrystalline with tetragonal structure with preferential orientation (112). raise the crystallinity degree. AFM used to study the effect of Al on surfaces roughness and Grain Size Optical properties such as the optical band gap, absorption coefficient, Extinction coefficient, refractive ind

... Show More
View Publication
Scopus (6)
Crossref (5)
Scopus Clarivate Crossref
Publication Date
Tue Nov 09 2021
Journal Name
Energies
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, i

... Show More
View Publication
Scopus (22)
Crossref (23)
Scopus Clarivate Crossref
Publication Date
Sat Oct 16 2021
Journal Name
Iraqi Journal Of Physics
Numerical analysis of molecules intersystem crossing effect on a passively Q- switched laser pulse characteristics
...Show More Authors

The effect of molecules intersystem crossing (Kisc) on characteristics
(energy and duration) of a Passive Q- switched Laser Pulse has been
studied by mathematical description (rate equations model) for
temporal performance of which was used as a saturable absorber
material (passive switch) with laser. The study shows that the energy
and duration pulse are decreasing while the molecules intersystem
crossing into saturable absorber energy levels is increasing.

View Publication Preview PDF
Publication Date
Sat Jun 01 2024
Journal Name
Applied Thermal Engineering
Design and optimization of a household photovoltaic/thermal collector with serpentine tube: Energy and exergy analysis
...Show More Authors

View Publication
Scopus (27)
Crossref (30)
Scopus Crossref
Publication Date
Thu Jun 15 2017
Journal Name
Journal Of Baghdad College Of Dentistry
A Comparison of Vertical Marginal Fit of different Brands of Translucent Zirconia Crown Restorations
...Show More Authors

Background: As the development of zirconia crown using CAD/CAM technology, the usage of full zirconia crown is gradually increased. The aim of this in-vitro study was to evaluate and contrast the vertical marginal fit of single all-ceramic translucent zirconia crowns constructed from different brands translucent zirconia blanks. Materials and Methods: An acrylic resin model of a left maxillary premolar was prepared all around the tooth with (1 mm) depth and 3D scanning to get fifteen STL files, then distributed into three groups (Imes-icor, Whitepeaks and Dental direct), 3D scanning and milling machine by Imes-icor CAD/CAM devise. Marginal gaps along vertical planes were measured at four indentations at the (mid mesial, mid distal, mid bucc

... Show More
View Publication Preview PDF
Crossref
Publication Date
Tue Feb 01 2022
Journal Name
Civil Engineering Journal
Calibration of a New Concrete Damage Plasticity Theoretical Model Based on Experimental Parameters
...Show More Authors

The introduction of concrete damage plasticity material models has significantly improved the accuracy with which the concrete structural elements can be predicted in terms of their structural response. Research into this method's accuracy in analyzing complex concrete forms has been limited. A damage model combined with a plasticity model, based on continuum damage mechanics, is recommended for effectively predicting and simulating concrete behaviour. The damage parameters, such as compressive and tensile damages, can be defined to simulate concrete behavior in a damaged-plasticity model accurately. This research aims to propose an analytical model for assessing concrete compressive damage based on stiffness deterioration. The prop

... Show More
Scopus (40)
Crossref (34)
Scopus Clarivate Crossref