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Free Convective Heat Transfer with Different Sections Lengths Placed at the Exit of a Vertical Circular Tube subjected to a Constant Heat Flux
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A free convective heat transfer from the inside surface of a uniformly heated vertical circular tube has been experimentally investigated under a constant wall heat flux boundary condition for laminar air flow in the ranges of RaL from 6.9108 to 5109. The effect of the different sections (restrictions) lengths placed at the exit of the heated tube on the surface temperature distribution, the local and average heat transfer coefficients were examined. The experimental apparatus consists of aluminum circular tube with 900 mm length and 30 mm inside diameter (L/D=30). The exit sections (restrictions) were included circular tubes having the same inside diameter as the heated tube but with different lengths of 600 mm (L/D=20), 900 mm (L/D=30), 1200 mm (L/D=40), 1500 mm (L/D=50), and 1800 mm (L/D=60). It was found that the surface temperature along the tube axial distance would be higher for restriction with length of 1800 mm (L/D=60) and it would be smaller for the restriction with length of 1200 mm (L/D=40). The results show that the local Nux and average Nusselt number were higher values for the restriction with length of 1200 mm (L/D=40) and smaller values for the restriction with length of 1800 mm (L/D=60). The results were correlated with empirical equations and presented as Logagainst Log for each case investigated and a general empirical equation was proposed for all cases.

 

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Publication Date
Sun Mar 06 2022
Journal Name
Al–bahith Al–a'alami
The exposure of the elderly to the news of the Corona pandemic TV and its reflection on their behavior: A survey study of a sample of the public of Baghdad governorate
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A Survey Study Of A Sample Of The Public Of Baghdad  Governorate

The current study aimed to identify the most prominent psychological and behavioral repercussions of the exposure of the elderly to the news of the Corona pandemic and to determine the mechanisms of their exposure. On an intended sample on both sides of (Al-Karkh and Al-Rasafa) and the simple random sample was adopted to choose the place of distribution of the questionnaire and the intentional sample.

 The research concluded several results, most TV news is still a primary source of information and that most of the sample move between stations to see more information about the pandemic and that the presentation of views confuses the elderly ،There

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Crossref
Publication Date
Wed Dec 27 2017
Journal Name
Al-khwarizmi Engineering Journal
A New Approach for Designing Multi Information Management System Using XML Technology
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XML is being incorporated into the foundation of E-business data applications. This paper addresses the problem of the freeform information that stored in any organization and how XML with using this new approach will make the operation of the search very efficient and time consuming. This paper introduces new solution and methodology that has been developed to capture and manage such unstructured freeform information (multi information) depending on the use of XML schema technologies, neural network idea and object oriented relational database, in order to provide a practical solution for efficiently management multi freeform information system.

    

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Publication Date
Sun Jan 13 2019
Journal Name
Iraqi Journal Of Physics
Measurement of background radiation, cosmic ray flux and their hazard parameter of Baghdad city districts
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The aim of this work was directed to measure the cosmic ray (CR)
flux and the background (BG) absorbed dose rate for districts of
Baghdad city. The maximum values of CR flux was 2.01
(particle/cm2.s) registered for several Baghdad districts and the
minimum was 0.403 (particle/cm2.s) belonging to Al-kadhimiya
district, whereas the overall average value was 1.24 (particle/cm2.s).
The BG measurements showed that the maximum absorbed dose was
25 nSv/h belonging to Noab AL-Dhbat district and the minimum
absorbed was 19.01 nSv/h observed in Al-Ghadeer district, while
the overall average was 22.56 nSv/h, and this value is small than the
Iraqi permissible limit, which is restricted by Iraqi Center of
Radiation Pr

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Crossref
Publication Date
Mon May 08 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Calculation the Cross Sections of 10B(n,p)10Be Reaction by Using the Reciprocity Theory for the First Excited State
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  In this study light elements 10B , 10Be for 10B(n,p)10Be reaction as well as proton energy from 0.987 MeV to 2.028 MeV with threshold energy (1.04MeV) are used according to the available data of reaction cross sections. The more recent cross sections data of 10Be(p,n)10B reaction is reproduced in fin steps in the specified energy range , as well as cross section (p,n) values were derived from the published data of (n,p) as a function of energy in the same fine energy steps by using the reciprocity theory of principle inverse reaction . This calculation involves only the first excited state of  10B , 10Be in the reactions 10Be(p,n)10B and  10B(n,p)10Be. 

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Publication Date
Sat Jun 03 2023
Journal Name
Iraqi Journal Of Science
Benthic Foraminiferal biostratigraphy of the Euphrates Formation (Early Lower Miocene-Middle Miocene) in selected sections, Western Iraq
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Studies of three surface sections of the Euphrates Formation in its type locality Western Iraq, yielded a rich benthic foraminifera. Tabulation of the results showed more or less similar content which are previously studied except for the presence for the first time of Triloculina trigonula Lamark, Triloculina tricarinata D'orbigny in the lower parts and Spirolina cf. cylindracea Lamark in the upper parts. In addition two Biozone established in the studies sections, the lower Ammonia beccarii zone and upper Ammonia beccarii-Borelis melo curdica zone

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Publication Date
Wed May 10 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Density and Viscosity of Amino Acid Serine in Aqueous Dimethyl Sulfoxide Solution at Different Temperatures
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Densities
 and viscosity
 of serine in 20, 40, and 60% (w/w) dimethyl sulfoxide (DMSO)-water mixtures were measured at 298.15, 303.15 and 308.15k. From these experimental data, apparent molal volume v  , limiting apparent molal volume v  o , the slop v S , transfer volume  v  o(tr), Jones-Dole coefficients A and B were calculated. The results are
v  odiscussed the solute-solvent and solute-solute interaction, and showed that serine behaves as structure-breaker in aqueous DMSO solvent

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Publication Date
Mon May 08 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Viscosity and Density of Chrom Alum in Aqueous Poly (Ethylene Glycol) Solution at Different Temperature
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   Density data of  alum chrom in water and in aqueous solution of poly (ethylene glycol) (1500) at different temperatures (288.15, 293.15, 298.15) k have been used to estimate the apparent molar volume (Vθ), limiting apparent molar volume (Vθ˚) experimental slope (Sv) and the second derivative of limiting partial molar volume [δ2 θ v° /δ T2] p .The viscosity data have been analyzed by means of Jones –Dole equation to obtain coefficient A, and  Jones – Dole coefficient B, Free activation  energy of activation per mole of solvent, Δμ10* solute, Δμ20* the activation enthalpy ΔH*,and entropy, ΔS*of activation of viscous flow. These results have been discussed

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Publication Date
Mon Oct 01 2018
Journal Name
Journal Of Engineering
Synthesis and Characterization of Magnetic Iron Oxide Nanoparticles by Co-Precipitation Method at Different Conditions
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Magnetic nanoparticles (MNPs) of iron oxide (Fe3O4) represent the most promising materials in many applications. MNPs have been synthesized by co-precipitation of ferric and ferrous ions in alkaline solution. Two methods of synthesis were conducted with different parameters, such as temperature (25 and 80 ̊C), adding a base to the reactants and the opposite process, and using nitrogen as an inert gas. The product of the first method (MNPs-1) and the second method (MNPs-2) were characterized by x-ray diffractometer (XRD), Zeta Potential, atomic force microscope (AFM) and scanning electron microscope (SEM). AFM results showed convergent particle size of (MNPs-1) and (MNPs-2) with (86.01) and (74.14)

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Crossref (32)
Crossref
Publication Date
Thu May 02 2024
Journal Name
Iraqi Journal Of Applied Physic
Photosensitivity of Nb2O5/Si Thin Films Produced via DC Reactive Sputtering at Different Substrate Temperatures
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This study thoroughly investigates the potential of niobium oxide (Nb2O5) thin films as UV-A photodetectors. The films were precisely fabricated using dc reactive magnetron sputtering on Si(100) and quartz substrates, maintaining a consistent power output of 50W while varying substrate temperatures. The dominant presence of hexagonal crystal structure Nb2O5 in the films was confirmed. An increased particle diameter at 150°C substrate temperature and a reduced Nb content at higher substrate temperatures were revealed. A distinct band gap with high UV sensitivity at 350 nm was determined. Remarkably, films sputtered using 50W displayed the highest photosensitivity at 514.89%. These outstanding optoelectronic properties highlight Nb2O5 thin f

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Publication Date
Sat Sep 01 2012
Journal Name
Australian Journal Of Basic And Applied Sciences
Electrochemical interferences of Mn<sup>2+</sup> with Hg<sup>2+</sup>, Cd<sup>2+</sup> and Cu<sup>2+</sup> at different modified GCE
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Glassy carbon electrode (GCE) was modified with carbon nanotubes CNT and C60 by attachment and solution evaporation techniques, respectively. CNT/Li+/GCE and C60/Li+/GCE were prepared by modifying CNT/GCE and C60/GCE in Li+ solution via cyclic voltammetry (CV) potential cycling. The sensing characteristics of the modified film electrodes, demonstrated in this study for interference of Mn2+ in different heavy metals ion esp. Hg2+, Cd2+ and Cu2+. The interfering effect was investigated that exert positive interference on the redox peaks of Mn2+. The modification of GCE with nano materials and Li+ act an enhancement for the redox current peaks to observe the effect of interference for Mn2+ in 1:1 ratio with different heavy metals ion.

Scopus (3)
Scopus