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INVESTIGATION OF TWISTED TAPE TURBULATOR FOR FIRE TUBE BOILER Part I. Heat Transfer
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The present work presents a new experimental study of the enhancement of turbulent
convection heat transfer inside tubes for combined thermal and hydrodynamic entry length of one
popular “turbulator” (twisted tape with width slightly less than internal tube diameter) inserted for
fire tube boilers. Cylindrical combustion chamber was used to burn (1.6 to 7kg/h) fuel oil #2 to
deliver hot gases with ranges of Reynolds number (10500 to 21700), and (11400 to 24150) for both
empty and inserted tube respectively.A uniform wall temperature technique was used by keeping
approximately constant water temperature difference (25ºC) between inlet and exit cooling water in
parallel flow shell and tube heat exchanger. The test tube consisted of smooth carbon steel tube of
(2400mm) long and (52mm) internal diameter. This test tube instrumented to derive local heat
transfer coefficient and local flue gasses static pressure.The experimental results show that for the
same fuel consumption, twisted tape insert with (H/D = 11.15) enhanced the mean Nusselt number
in (75.2%), (68.8%), (49.8%), (40.3%), and (16.7%) for fuel consumption (7kg/h), (6.16kg/h),
(4.5kg/h), (3.24kg/h), and (1.6kg/h) respectively.A set of empirical correlations that permit the
evaluation of the mean Nusselt number (for developing and fully developed region), and average
Nusselt number (for developed region) for empty and inserted tube are generated for engineering
applications.

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Publication Date
Sat Mar 31 2018
Journal Name
Journal Of Engineering
Effect of Using Extra Fins on the Pin Fin Classic Geometry for Enhancement Heat Sink Performance using EGM Method
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In the present study, the effect of new cross-section fin geometries on overall thermal/fluid performance had been investigated. The cross-section included the base original geometry of (triangular, square, circular, and elliptical pin fins) by adding exterior extra fins along the sides of the origin fins. The present extra fins include rectangular extra fin of 2 mm (height) and 4 mm (width) and triangular extra fin of 2 mm (base) 4 mm (height). The use of entropy generation minimization method (EGM) allows the combined effect of thermal resistance and pressure drop to be assessed through the simultaneous interaction with the heat sink. A general dimensionless expression for the entropy generation rate is obtained by con

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Publication Date
Tue Jan 18 2022
Journal Name
Materials Science Forum
Effect Partial Substitution of Calcium by <i>Cadmium</i> on Dielectrically Properties of Li0.4Cd0.6Ba2Ca2Cu3O10+δ System
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In this article the conventional "solid-state reaction" method was used to synthesize perovskite Li0.4Cd0.6Ba2Ca2Cu3O10+δ. Four main types of compounds were obtained by physically replacing calcium oxide with cadmium in proportions 0, 0.03, 0.06 and 0.09, the pure Li0.4Cd0.6Ba2Ca2Cu3O10+δ phase, and the phases Li0.4Cd0.6Ba2Ca1.97Cd0.03Cu3O10+δ

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Publication Date
Fri Dec 01 2023
Journal Name
Iranian Journal Of Medical Microbiology
Detection of Biologically Active Compounds in <i>Eriobotrya japonica</i> L. Seeds Extract and Determination of Their Effectiveness Against Dermatophytes
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Publication Date
Wed Jun 01 2022
Journal Name
Canadian Journal Of Chemistry
Hydrogenation of pyridine and hydrogenolysis of piperidine over <i>γ-</i>Mo<sub>2</sub>N catalyst: a DFT study
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Increasing demands on producing environmentally friendly products are becoming a driving force for designing highly active catalysts. Thus, surfaces that efficiently catalyse the nitrogen reduction reactions are greatly sought in moderating air-pollutant emissions. This contribution aims to computationally investigate the hydrodenitrogenation (HDN) networks of pyridine over the γ-Mo2N(111) surface using a density functional theory (DFT) approach. Various adsorption configurations have been considered for the molecularly adsorbed pyridine. Findings indicate that pyridine can be adsorbed via side-on and end-on modes in six geometries in which one adsorption site is revealed to have the lowest adsorption energy (

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Publication Date
Mon Jan 01 2007
Journal Name
Journal Of Educational And Psychological Researches
Evaluating the Professional Efficiency of Primary School Teachers in Teaching Rafidain English Course for Iraq, Book I
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      Teaching techniques are the vehicles, which are used by teachers to help pupils learn and gain experiences and create positive classroom activities, as much as these techniques are varied, they lead to successful and fruitful learning in the foreign language. They help teachers achieve their objectives (Asowrth, 1985: 124).

    The English language teacher's work is an active and purposeful one when he can plan carefully and frequently make the necessary changes in the contents and methods of teaching programme to fit the interest and needs of pupils. It seems that the majority of primary English teachers' interests does not go far in planning their work, and do not understand which o

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Publication Date
Mon Aug 08 2022
Journal Name
Archives Of Phytopathology And Plant Protection
First molecular confirmation of the fungus <i>Leveillula taurica</i> causing powdery mildew disease on sweet pepper in Iraq
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Publication Date
Fri Feb 14 2014
Journal Name
Journal Of Basic Microbiology
Isolation and characterization of lytic vibriophage against <i>Vibrio cholerae</i> O1 from environmental water samples in Kelantan, Malaysia
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Water samples from a variety of sources in Kelantan, Malaysia (lakes, ponds, rivers, ditches, fish farms, and sewage) were screened for the presence of bacteriophages infecting Vibrio cholerae. Ten strains of V. cholerae that appeared to be free of inducible prophages were used as the host strains. Eleven bacteriophage isolates were obtained by plaque assay, three of which were lytic and further characterized. The morphologies of the three lytic phages were similar with each having an icosahedral head (ca. 50–60 nm in diameter), a neck, and a sheathed tail (ca. 90–100 nm in length) characteristic of the family Myoviridae.

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Publication Date
Thu Dec 01 2016
Journal Name
Croatian Journal Of Fisheries
Morphometric Characteristics of Catfish<i>Silurus triostegus</i>(Heckel, 1843) from the Tigris and Shatt Al-Arab Rivers, Iraq
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Abstract<p>Thirteen morphometric characters of catfish<italic>Silurus triostegus</italic>were studied from three localities on the Tigris and Shatt al-Arab rivers, Iraq. Monthly samples revealed no significant differences between genders. Positive allometric growths for all morphometric characters studied were observed. This study gives information to fishery biologists about morphometric characters of<italic>S. triostegus</italic>from the Tigris and Shatt al-Arab rivers to assist in planning of conservation strategies for this fish species.</p>
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Publication Date
Sat Jan 01 2022
Journal Name
Rsc Advances
Antioxidant properties of butylated phenol with oxadiazole and hydrazone moiety at <i>ortho</i> position supported by DFT study
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Two series of 1,3,4-oxadiazole derivatives at the sixth position of the 2,4-di-tert-butylphenol group were synthesized.

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Publication Date
Fri Dec 01 2017
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
The Roleof Time Management in Stages Claims Settlement of Insurance from Fire: Research Exploratory in General Iraqi Insurance Company and Private Al hamra Company for Insurance
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The insurance activity in the various countries of the world are important indicators of the strength of the country's economy, he came to study the stages compensation insurance settlement against fire and the importance of investing time risk in achieving the payment of compensation speed, and the implications for the continuation of the insured to carry out insurance with the insurance company, whether working within the public sector or the private sector. Hence the research problem in how quickly insurance companies to pay compensation as soon as possible and the return of the insured to carry out its work and make up for what he died from loss. Intentional sample was selected from branches and divisions and Their assistants manager

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