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alkej-222
Study on Flow Characteristics and Heat Transfer Behavior Around Different Geometrical Corrugated Extended Surfaces
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Abstract

The current study presents numerical investigation of the fluid (air) flow characteristics and convection heat transfer around different corrugated surfaces geometry in the low Reynolds number region (Re<1000). The geometries are included wavy, triangle, and rectangular. The effect of different geometry parameters such as aspect ratio and number of cycles per unit length on flow field characteristics and heat transfer was estimated and compared with each other. The computerized fluid dynamics package (ANSYS 14) is used to simulate the flow field and heat transfer, solve the governing equations, and extract the results. It is found that the turbulence intensity for rectangular extended surface was larger than that of triangle and wavy extended surfaces at the same aspect ratio and number of cycles per unit length. Also, the increasing of turbulence intensity leads to enhance the heat transfer coefficient and consequently the amount of heat transfer. According to previous results, if the pressure head losses along the upstream are not important, the using of rectangular extended surface is better than the triangle which is also better than wavy extended surface.

Keywords: Flow Characteristics, Heat Transfer, Corrugated Surfaces, Numerical Analysis by ANSYS.

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Publication Date
Tue Mar 28 2023
Journal Name
International Journal Of Dentistry
The Effect of Different Obturation Techniques in Primary Teeth on the Apical Microleakage using Endoflas: A Comparative In Vitro Study
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Objectives. This study was carried out to quantitatively evaluate and compare the sealing ability of Endoflas by using differentobturation techniques. Materials and Methods. After 42 extracted primary maxillary incisors and canines were decoronated, theircanals were instrumented with K files of size ranging from #15 to #50. In accordance with the obturation technique, the sampleswere divided into three experimental groups, namely, group I: endodontic pressure syringe, group II: modified disposable syringe,and group III: reamer technique, and two control groups. Dye extraction method was used for leakage evaluation. Data wereanalyzed using one-way ANOVA and Dunnett’s T3 post hoc tests. The level of significance was set at p<0:05. Results.

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Publication Date
Mon Jun 01 2009
Journal Name
Al-khwarizmi Engineering Journal
Study the Effect Different Radioactive Dose on Mechanical Properties of Composite Material from Novolak Resin Exposure to High – Energy Radiation
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The research involves using phenol – formaldehyde (Novolak) resin as matrix for making composite material, while glass fiber type (E) was used as reinforcing materials. The specimen of the composite material is reinforced with (60%) ratio of glass fiber.

      The impregnation method is used in test sample preparation, using molding by pressure presses.

      All samples were exposure to (Co60) gamma rays of an average energy (2.5)Mev. The total doses were (208, 312 and 728) KGy.

      The mechanical tests (bending, bending strength, shear force, impact strength and surface indentation) were performed on un irradiated and irrad

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Publication Date
Tue Dec 01 2020
Journal Name
Journal Of Economics And Administrative Sciences
The effect of liquidity on the profitability and value of banks listed on Iraq stock market (An analytical study)
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  The purpose of the study is to analyze the extent of the impact of liquidity as an independent variable on profitability as an intermediate variable and the value of banks listed in the Iraq Stock Exchange as a dependent variable, as the research problem is summarized by the fact that most banks focus on profitability as a phased goal without focusing on maximizing its value as a strategic goal by enhancing the wealth of owners and shareholders. On the long term, the research community is represented by the banks listed on the Iraq Stock Exchange, while the research sample was deliberately chosen, which included three private banks such as Baghdad Commercial Bank, the Iraqi Commercial Bank and the Iraqi Investment Bank, an

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Publication Date
Fri Sep 01 2006
Journal Name
Journal Of Engineering
Effect of Transverse Base Width Restraint on the Cracking Behavior of Massive Concrete
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The effect of considering the third dimension in mass concrete members on its cracking behavior is investigated in this study. The investigation includes thermal and structural analyses of mass concrete structures. From thermal analysis, the actual temperature distribution throughout the mass concrete body was obtained due to the generation of heat as a result of cement hydration in addition to the ambient circumstances. This was performed via solving the differential equations of heat conduction and convection using the finite element method. The finite element method was also implemented in the structural analysis adopting the concept of initial strain problem. Drying shrinkage volume changes were calculated using the procedure suggested

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Publication Date
Sun May 12 2019
Journal Name
Al-khwarizmi Engineering Journal
Effect of Quenching Media Variations on the Mechanical Behavior of Martensitic Stainless Steel
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The purpose of this study is designate quenching and tempering heat treatment by using Taguchi technique to determine optimal factors of heat treatment (austenitizing temperature, percentage of nanoparticles, type of base media, nanoparticles type and soaking time) for increasing hardness, wear rate and impact energy properties of 420 martensitic stainless steel. An (L18) orthogonal array was chosen for the design of experiment. The optimum process parameters were determined by using signal-to-noise ratio (larger is better) criterion for hardness and impact energy while (Smaller is better) criterion was for the wear rate. The importance levels of process parameters that effect on hardness, wear rate and impact energy propertie

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Publication Date
Sun Jan 01 2023
Journal Name
8th Engineering And 2nd International Conference For College Of Engineering – University Of Baghdad: Coec8-2021 Proceedings
Effect of posts inclination on the behavior of prestressed quadrilateral perforated concrete rafter
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Publication Date
Sat Jul 22 2023
Journal Name
Journal Of Engineering
Effect of Transverse Base Width Restraint on the Cracking Behavior of Massive Concrete
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The effect of considering the third dimension in mass concrete members on its cracking behavior is investigated in this study. The investigation includes thermal and structural analyses of mass concrete structures. From thermal analysis, the actual temperature distribution throughout the mass concrete body was obtained due to the generation of heat as a result of cement hydration in
addition to the ambient circumstances. This was performed via solving the differential equations of heat conduction and convection using the finite element method. The finite element method was also implemented in the structural analysis adopting the concept of initial strain problem. Drying shrinkage volume changes were calculated using the procedure sug

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Publication Date
Tue Jun 01 2010
Journal Name
Al-khwarizmi Engineering Journal
'Influence of Draft Tube Diameter on Operation Behavior of Air Lift Loop Reactors
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The ratio of draft tube to reactor diameters is of decisive importance for the operation behavior of air lift loop reactors. The influence of draft tube geometry was investigated with respect to oxygen mass transfer and mixing time. The diameter ratio was varied between 0.33 and 0.80. The measurements were performed in two loop reactors with liquid capacities of 11.775 and 26.49 liters using aqueous with solutions of different coalescence behavior. The results show that there is no single diameter ratio which would produce most favorable conditions for the two process parameters. With respect to the more important requirements of aerobic cultures, i.e high oxygen mass transfer and efficient mixing, a diameter ratio between 0.5 and 0.6 is

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Publication Date
Sun Jun 06 2010
Journal Name
Baghdad Science Journal
Study the effect of Grave's disease on the different tissues and organs of the body by using Wayne Thyrotoxicosis Diagnostic Index(WTDI) and Basel Metabolic Index(BMI)
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The present work aimed to study the effect of Grave's disease on the different tissues and organs of the body by using Wayne Thyrotoxicosis Diagnostic Index (WTDI) and Basel Metabolic Index (BMI). To reach such aim, (35) patients were involved (25 females and 10 males). A control group of (15) healthy individuals (10 females and 5 males) was selected for comparison , as well as , the following: 1- Wayne Thyrotoxicosis Diagnostic Index (WTDI) applied on patient group and control group under the supervision of specialist medical team , this index include (19) sign and symptom , the appearance of one of them may be lead to the others. The sings and symptoms of the index appear only on the patients. There is no Significant di

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Publication Date
Sun Jun 01 2014
Journal Name
Baghdad Science Journal
A study of the physical and chemical characteristics of the waters of the central marshes in southern Iraq after restoration
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some ecological (physical and chemical varible) of water samples were studies monthly from December 2008 to May 2009 at two stations( St.1) Al - Chibayesh marsh and (St.2) Abu – Zirik marsh which are located in the south of Iraq . These variables included : Temperature, pH, EC, Dissolved oxygen , Total alkalinity, Nitrate, Sulphate, and phosphate, Si-SiO2 and Ca ,Mg, Cl, The marsh Considered as fresh water and alkaline. Abu-Zirik less than Al-Chibayesh.

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