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Thermal Characteristics of Closed Wet Cooling Tower Using Different Heat Exchanger Tubes Arrangement
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This paper presents thermal characteristics analysis of a modified Closed Wet Cooling Tower (CWCT) based on heat and mass transfer principles to improve the performance of this tower in Iraq. A prototype of CWCT optimized by added packing was designed, manufactured and tested for cooling capacity of 9 kW. Experiments are conducted to explore the effects of various operational and conformational parameters on the thermal performance. In the test section, spray water temperature and both dry bulb temperature and relative humidity of the air measured at intermediate points of the heat exchanger and packing. Heat exchangers consist of four rows and eight columns for an inline tubes arrangement and six rows and five columns for staggered tubes arrangement. According to experimental data, the inline tubes arrangement has a better thermal performance than the staggered tubes arrangement. The inline tubes arrangement enhanced thermal efficiency more than (7%) compared to the staggered tubes arrangement. Furthermore the effect of added packing to CWCT on thermal performance was significant compared to CWCT without packing. Comparing CWCT with packing, it has been observed that the best performance for the CWCT with packing under heat exchanger. It can be watched that the thermal efficiency for CWCT with packing under heat exchanger and CWCT with packing above heat exchanger approximately (28%) and (16%) higher than that CWCT without packing respectively. This study provides correlations to predict heat and mass transfer considering the influences of operational parameters for both inline and staggered heat exchanger tubes arrangement.

 

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Publication Date
Sun Mar 02 2008
Journal Name
Baghdad Science Journal
Design and construction of Video extractor
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Design and construction of video extractor circuit require an understanding of several parameters, which include: Selector circuit, extracting circuit which contains sampling signal and multiplexing. At each radar pulse, the video signal is fed to one of the selector. The fast filter has a pass –band from 190 Hz to 1800 Hz. These frequencies correspond to targets having radial velocities laying between and 10 Kph and 200 Kph.Slow filter: 60 Hz to 230 Hz for radial velocities laying between 3.5 and 13 Kph.The video- extractor is organized in four PCB CG (A-B-C-D) each one having 16 selector. The sampling signal (ADS) (1-2-3-4) control the 4-line-to-16-line decoders. 8 multiplexers of 8 inputs each, are required for the multiplexing of the

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Publication Date
Sun Sep 30 2007
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Quality Improvement of Spent Lubricating Oil
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The acidity of spent lubricant was treated using sodium hydroxide solution. The effect of three variables on the treatment have been studied . These are mixing time rangingfrom 5-35 minutes, NaOH to lubricant weight ratio ranging from  0.25-1.25 and weight percentage  of NaOH ranging from  2-6 % .

The experimental design of Box-Wilson method is adopted to find a useful relationship between the three controllable variables and the lowering in the acidity of the spent lubricant. Then the effective variables and interactions are identified using the statistical analysis(F-test) of  three variable fractional design. The mathematical model is well represented  by a second order polynomial.

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Publication Date
Sat Jun 30 2018
Journal Name
College Of Islamic Sciences
The grammatical views of the Chalobini
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This research deals with the most important grammatical views of the science of the media of the Arab and Andalusian grammar is: Abu Ali al-Shloubini, who filled his name the pages of important grammatical books such as: (singer Al-Labib) Ibn Ibn Hisham, and the book (like and analogues), and (Hama Alhwama) for Suyuti, and other books The task, I have divided my research into the topics: I talked in the first section on his life and his biography and his works, and the second topic: it included his independent opinions and the third section contained the most prominent views selected The fourth and final topic, was his responses to grammarians, and concluded my research with the most prominent findings Research to them, which was the mos

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Publication Date
Sun Jun 01 2014
Journal Name
Baghdad Science Journal
Fabrication of multi-junction solar cells
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Fabrication of solar cell prepared by thermal spray and vacuum thermal evaporation method on silicon wafer(n-type) and studying its efficiency. The film have been deposited on three layers(ZnO then CdS and CdTe) on Si and glass respectively.Direct energy gap was calculated and equal to (4.3,3.4,3)eV and indirect energy gap equal to (3.5,2.5,1.5)eV respectively . Efficiency was calculated for the cell of area 2cm2 it was equal to 0.14%.

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Publication Date
Wed Jan 02 2019
Journal Name
Journal Of Educational And Psychological Researches
The vigilant personality of University teachers
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This research aims to identify the vigilant personality of University teachers in term of gender. To this end, the researcher used the scale of Al-tememe (2017) for the vigilant personality, the scale was administered to the sample of the study which was (100) male and female teachers. The results have shown that university teachers generally have a vigilant personality, as well as the result showed a difference between male and female teachers on the level of vigilant personality in favor of males. In the light of these results the researcher has come with a number of recommendations and suggestions.

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Publication Date
Thu Jul 01 2021
Journal Name
Iraqi Journal Of Science
Synthesis and Characterization of Cu2FeSnSe4 Nanofilms
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Well dispersed Cu2FeSnSe4 (CFTSe) nanofilms were synthesized by hot-injection method. The structural and morphological measurements were characterized using XRD (X-ray diffraction), Raman spectroscopy, SEM (scanning electron microscopy), and TEM (transmission electron microscopy). Chemical composition and optical properties of as-synthesized CFTSe nanoparticles were characterized using EDS (energy dispersive spectroscopy) and UV-Vis spectrophotometry. The average particle size of the nanoparticles was about 7-10 nm. The UV-Vis absorption spectra showed that the synthesized CFTS nanofilms have a band gap (Eg) of about 1.16 eV. Photo-electrochemical characteristics of CFTSe nanoparticles were studied and indicated their potential application

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Publication Date
Mon Jul 27 2026
Journal Name
Al-rafidain University College For Sciences
Uncertainty types and theories of treatment
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In this research the researcher had the concept of uncertainty in terms of types and theories of treatment and measurement as it was taken up are three types of indeterminacy and volatility and inconsistency

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Publication Date
Sun Jan 01 2023
Journal Name
Aip Conference Proceedings
Nano chitosan adsorption of o-Nitroaniline
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Publication Date
Sat Feb 09 2019
Journal Name
Journal Of The College Of Education For Women
To Develop of Arabian high Education
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The research focuses,in the first place, on six fields.The most important one is
curriculum field which includes the revision of the current academic curriculums and
substitute them with recent ones, beside the rehabilitation of academic labs and factories by
providing them with modern scientific technologies employed in the world. Regarding the
economical field, it seeks to provide high-level training staffs to serve different social and
economical sectors through modern effective technological and scientific
curriculums.Whereas the social field assures the concern of different social classes who
deprived from the grace of higher education such as retirees and elderly people and to set-up
some educational and ent

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Publication Date
Sun Jun 05 2016
Journal Name
Baghdad Science Journal
On the Representations of M-Groups
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The main object of this paper is to study the representations of monomial groups and characters technique for representations of monomial groups. We refer to monomial groups by M-groups. Moreover we investigate the relation of monomial groups and solvable groups. Many applications have been given the symbol G e.g. group of order 297 is an M-group and solvable. For any group G, the factor group G/G? (G? is the derived subgroup of G) is an M-group in particular if G = Sn, SL(4,R).

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