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alkej-529
The Effects of Vortex Generator Types on Heat Transfer and Flow Structure in a Rectangular Duct Flows
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    In this numerical study a detailed evaluation of the heat transfer characteristics and flow structure in a laminar and turbulent flow through a rectangular channel containing built-in of different type vortex generator has been a accomplished in a range of Reynolds number between 500 and 100,000.A modified version of ESCEAT code has been used to solve Navier-Stokes and energy equations. The purpose of this paper is to present numerical comparisons in terms of temperature, Nusselt number and flow patterns on several configurations of longitudinal vortex generator including new five cases. The structures of heat and flow were studied, using iso-contours of velocity components, vortices, temperature and Nusselt number. This study shows that the predicted structures of fluid flow, temperature fields and Nusselt number variation are strongly affected by the presence of the turbulators. Staggered arrangement gains high Nusselt number, also the lower and upper arrangements have higher Nusselt number than plane duct. High Reynolds number (higher air inlet velocity) will enhance the Nusselt number. Increase in ribs height will enhance the heat transfer as it works as surface area and turbulator at the same time. 

 

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Publication Date
Sun Jan 01 2023
Journal Name
Journal Of The Mechanical Behavior Of Materials
Efficiency of CFRP torsional strengthening technique for L-shaped spandrel reinforced concrete beams
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Abstract<p>The present study aims to get experimentally a deeper understanding of the efficiency of carbon fiber-reinforced polymer (CFRP) sheets applied to improve the torsional behavior of L-shaped reinforced concrete spandrel beams in which their ledges were loaded in two stages under monotonic loading. An experimental program was conducted on spandrel beams considering different key parameters including the cross-sectional aspect ratio (<italic>i.e.</italic>, web height/web thickness), and the availability of the CFRP strengthening system. The ledge of the spandrel beams was exposed during testing to a very high eccentric load, which was transferred to the web of the spandrel beam </p> ... Show More
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Publication Date
Sun May 11 2025
Journal Name
Iraqi Statisticians Journal
Estimating General Linear Regression Model of Big Data by Using Multiple Test Technique
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Publication Date
Sat Apr 01 2017
Journal Name
مجلة العلوم الاحصائية
نمذجة السلاسل الزمنية التي تنتجها اجهزة الاحصاء الدولية وانتاج قيم تنبؤية لمتخذ القرار حالة دراسية : التنبؤ بالمساحة المزروعة لمحصول الذرة الصفراء في العراق للفترة (2015-2020
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تنفذ أجهزة اإلحصاء الدولية ومنها الجهاز المركزي لإلحصاء في العراقإحدى أجهزة وزارة التخطيط، تقوم بإجراء مسوح سنوية ودورية لإنتاج مؤشرات تقييم وتقويم أنشطة القطاعات الاقتصادية المختلفة. يتيح هذا الكم الهائل من البيانات بشكل سلسل زمني لهذه الأجهزة إنتاج مؤشرات جديدة، بما في ذلك القيم التنبؤية لمؤشرات رئيسية تستخدم في إعداد الخطط طويلة وقصيرة المدى. في عام 2015، قامت مديرية الإحصاء الزراعي في الجهاز المركزي للإ

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Publication Date
Sat Apr 01 2023
Journal Name
Viii. International Scientific Congress Of Pure, Applied And Technological Sciences (minar Congress)
DETERMINING AN APPROPRIATE INITIAL VALUE OF ECCENTRICITY FOR LOW EARTH SATELLITES USING EULER METHOD
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The major goal of this research was to use the Euler method to determine the best starting value for eccentricity. Various heights were chosen for satellites that were affected by atmospheric drag. It was explained how to turn the position and velocity components into orbital elements. Also, Euler integration method was explained. The results indicated that the drag is deviated the satellite trajectory from a keplerian orbit. As a result, the Keplerian orbital elements alter throughout time. Additionally, the current analysis showed that Euler method could only be used for low Earth orbits between (100 and 500) km and very small eccentricity (e = 0.001).

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Publication Date
Wed Nov 01 2017
Journal Name
International Journal Of Greenhouse Gas Control
Wettability of nano-treated calcite/CO2 /brine systems: Implication for enhanced CO2 storage potential
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Nanofluids are proven to be efficient agents for wettability alteration in subsurface applications including enhanced oil recovery (EOR). Nanofluids can also be used for CO2-storage applications where the CO2-wet rocks can be rendered strongly water-wet, however no attention has been given to this aspect in the past. Thus in this work we presents contact angle (θ) measurements for CO2/brine/calcite system as function of pressure (0.1 MPa, 5 MPa, 10 MPa, 15 MPa, and 20 MPa), temperature (23 °C, 50 °C and 70 °C), and salinity (0, 5, 10, 15, and 20% NaCl) before and after nano-treatment to address the wettability alteration efficiency. Moreover, the effect of treatment pressure and temperature, treatment fluid concentration (SiO2 wt%) and

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Publication Date
Sun Jan 01 2017
Journal Name
Journal Of Engineering
Performance Enhancement of an Air Cooled Air Conditioner with Evaporative Water Mist Pre-cooling
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The present paper deals with experimental investigation of the performance of air cooled split air conditioner, with evaporative water mist pre cooling to increase the cooling capacity and reduce the consumption power under hot and dry climate. This investigation considers how the performance can be enhanced by using water mist to pre-cool ambient air entering the condensers by adiabatic cooling process which depends on the ambient air wet bulb temperature; as well the condensing temperature and condensing pressure will be decreased accordingly. So the cooling capacity would be increased and consumption power would be decreased, consequently the energy ratio, EER would be improved. The performance of air cooled air conditioner with water

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Publication Date
Mon Dec 31 2012
Journal Name
Al-khwarizmi Engineering Journal
Field Programmable Gate Array (FPGA) Model of Intelligent Traffic Light System with Saving Power
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In this paper, a FPGA model of intelligent traffic light system with power saving was built. The intelligent traffic light system consists of sensors placed on the side's ends of the intersection to sense the presence or absence of vehicles. This system reduces the waiting time when the traffic light is red, through the transition from traffic light state to the other state, when the first state spends a lot of time, because there are no more vehicles. The proposed system is built using VHDL, simulated using Xilinx ISE 9.2i package, and implemented using Spartan-3A XC3S700A FPGA kit. Implementation and Simulation behavioral model results show that the proposed intelligent traffic light system model satisfies the specified operational req

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Publication Date
Sun Jan 01 2023
Journal Name
Journal Of Environmental Engineering And Science
Fenton-like degradation of direct blue dye using green synthesised Fe/Cu bimetallic nanoparticles
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This study relates to synthesis of bentonite-supported iron/copper nanoparticles through the biosynthesis method using eucalyptus plant leaf extract, which were then named E-Fe/Cu@B-NPs. The synthesised E-Fe/Cu@B-NPs were examined by a set of experiments involving a heterogeneous Fenton-like process that removed direct blue 15 (DB15) dye from wastewater. The resultant E-Fe/Cu@B-NPs were characterised by scanning electron microscopy, Brunauer–Emmet–Teller analysis, zeta potential analysis, Fourier transform infrared spectroscopy and atomic force microscopy. The operating parameters in batch experiments were optimised using Box–Behnken design. These parameters were pH, hydrogen peroxide (H2O2

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Publication Date
Sun Dec 03 2017
Journal Name
Sci. Int.(lahore)
IMPROVING NO2 SENSITIVITY OF POROUS SILICON BY FUNCTIONALIZATION ITS SURFACE WITH COPPER AS CATALYST
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In this work, porous silicon gas sensor hs been fabricated on n-type crystalline silicon (c-Si) wafers of (100) orientation denoted by n-PS using electrochemical etching (ECE) process at etching time 10 min and etching current density 40 mA/cm2. Deposition of the catalyst (Cu) is done by immersing porous silicon (PS) layer in solution consists of 3ml from (Cu) chloride with 4ml (HF) and 12ml (ethanol) and 1 ml (H2O2). The structural, morphological and gas sensing behavior of porous silicon has been studied. The formation of nanostructured silicon is confirmed by using X-ray diffraction (XRD) measurement as well as it shows the formation of an oxide silicon layer due to chemical reaction. Atomic force microscope for PS illustrates that the p

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Publication Date
Mon Aug 04 2014
Journal Name
Iraqi National Journal Of Chemistry
Comparative Study for Antibacterial Activity of Some Maleamic acid Derivatives with Some Commercial Antibiotic
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