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Heat Transfer Characteristics of a Fluid Flow in Multi Tube Heat Exchanger Fitted with Perforated Fins
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The heat transfer and flow resistance characteristics for air flow cross over circular finned tube heat exchanger has been studied numerically and experimentally. The purpose of the study was to improve the heat transfer characteristics of an annular finned-tube heat exchanger for better performance. The study has concentrated on the effect of the number of perforations and perforations shapes on the heat transfer and pressure drop across a staggered finned tube heat exchanger. The Numerical part of present study has been performed using ANSYS Fluent 14.5 using SST Turbulent model, while the experimental study consist from a test rig with different models of heat exchangers and all required measurement devices were building up to cover the experimental work for the range of Reynolds number (7500-17500). The experimental results show that average Nusselt number of the six circular perforations fins model is about 11.08 % higher than that for solid fin model and with triangular perforations model is about 10.12 % higher than that for the solid fin. Triangular perforation finned heat exchanger model gives  a best result than the other models due to excessive increment in the )Nu( in comparison with other models take in consideration pressure drop. The results were validated with previous work and the comparison between the experimental and numerical shows a good agreement with a maximum deviation ±10% between them.

 

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Publication Date
Fri Sep 22 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Photoinduced Electron Transfer Between Metalloporphyrin Complex Dihydroxy Antimony ( v) Tetrapbenylporphine and Halide in Acetonitrile Solution
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:Electron transfer (El) through molecular frameworks is. ce.ntral

to  a wide  range  of  chemical,  physical  ,  an   biological   processes. Atheoretical  calculation  Â·investigation   of  (ED  between  dihydroxy antimony  (V)   tetraP.henylporphine cation  (Sb''(TP.P)(04)2] and halid cr,Br·,r ,and SCN- is presented . These Calculations &re  is fiting on experrnental  studies  Showing  that the rate of Electron Transfer. The theoretical  Calculation   are   based  Â·an   a   eontinm: m   theory.   The tran:sferr ng &nbsp

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Publication Date
Thu Aug 06 2009
Journal Name
Dirasat
Geneses of the zinc-lead – barite deposits in the Northern Iraq: ore mineralogy, geochemistry, fluid inclusions, lead isotopes and sulfur isotopes implicatiuons
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Publication Date
Wed Jan 01 2020
Journal Name
Indian Journal Of Forensic Medicine And Toxicology
Continuous Flow Injection Analysis,Turbidmetric and Photometric Determination of Methyldopa Using a New Long Distance Chasing Photometer (NAG-ADF-300-2)
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A specific, sensitive and new simple method was used for the determination of methyldopa in pure and pharmaceutical formulations by using continuous flow injection analysis. This method is based on formation of ion pair compound between methyldopa and potassium hexacyanoferrate in acidic medium to obtain a yellow precipitate complex using long distance chasing photometer (NAG-ADF-300-2). The linear range for calibration graph was 0.05-35 mmol/L for cell A and 0.05-25 mmol/L for cell B, and LOD 1.4292 µg /200 µL for both cells with correlation coefficient (r) 0.9981 for cell A and 0.9994 for cell B, RSD% was lower than 0.5 % for n=8 for. The results were compared with classical method UV-Spectrophotometric at λ max=280 nm and turbi

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Publication Date
Wed Mar 01 2017
Journal Name
Ieee Transactions On Cognitive Communications And Networking
Multi-Channel Distributed DSA Networks: Connectivity and Rendezvous Tradeoffs
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In this paper, we investigate and characterize the effects of multi-channel and rendezvous protocols on the connectivity of dynamic spectrum access networks using percolation theory. In particular, we focus on the scenario where the secondary nodes have plenty of vacant channels to choose from a phenomenon which we define as channel abundance. To cope with the existence of multi-channel, we use two types of rendezvous protocols: naive ones which do not guarantee a common channel and advanced ones which do. We show that, with more channel abundance, even with the use of either type of rendezvous protocols, it becomes difficult for two nodes to agree on a common channel, thereby, potentially remaining invisible to each other. We model this in

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Publication Date
Sun Feb 25 2024
Journal Name
Baghdad Science Journal
Research on Emotion Classification Based on Multi-modal Fusion
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Nowadays, people's expression on the Internet is no longer limited to text, especially with the rise of the short video boom, leading to the emergence of a large number of modal data such as text, pictures, audio, and video. Compared to single mode data ,the multi-modal data always contains massive information. The mining process of multi-modal information can help computers to better understand human emotional characteristics. However, because the multi-modal data show obvious dynamic time series features, it is necessary to solve the dynamic correlation problem within a single mode and between different modes in the same application scene during the fusion process. To solve this problem, in this paper, a feature extraction framework of

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Publication Date
Sat Oct 01 2016
Journal Name
2016 2nd International Conference On Science In Information Technology (icsitech)
Cloud computing sensitive data protection using multi layered approach
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Publication Date
Sun Jan 01 2023
Journal Name
Computers, Materials & Continua
Submarine Hunter: Efficient and Secure Multi-Type Unmanned Vehicles
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Publication Date
Sun Aug 01 2021
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Novel Heuristic Approach for Solving Multi-objective Scheduling Problems
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    In this paper, we studied the scheduling of  jobs on a single machine.  Each of n jobs is to be processed without interruption and becomes available for processing at time zero. The objective is to find a processing order of the jobs, minimizing the sum of maximum earliness and maximum tardiness. This problem is to minimize the earliness and tardiness values, so this model is equivalent to the just-in-time production system. Our lower bound depended on the decomposition of the problem into two subprograms. We presented a novel heuristic approach to find a near-optimal solution for the problem. This approach depends on finding efficient solutions for two problems. The first problem is minimizing total completi

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Publication Date
Sat Jun 21 2025
Journal Name
Journal Of Baghdad College Of Dentistry
Postoperative assessment of dental implants by using multi-slice computed tomography
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Background: Implantology is a fast growing area in dentistry. One of the most common issues encountered in dental implantation procedures is the lack of adequate preoperative planning. Conventional radiography may not be able to assess the true regional three-dimensional anatomical presentation. Multi Slice Computed Tomography provides data in 3-dimentional format offering information on craniofacial anatomy for diagnosis; this technology enables the virtual placement of implant in a 3-Dimensional model of the patient jaw (dental planning). Patients, Material and Methods: The sample consisted of (72) Iraqi patients indicated for dental implant (34 male and 38 female), age range between (20-70) years old. They were examined during a time p

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Publication Date
Sat Jan 05 2019
Journal Name
Iraqi Journal Of Physics
Functionalization of single and multi-walled carbon nanotubes by chemical treatment
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In this work we experimentally investigated SWCNTs and MWCNTs to increase their thermal conductivity and electrically functionalization process using different reagents ((nitric acid, HNO3 followed by acid treatment with H2SO4), then washed with deionized water (DW) and then treated with H2O2 via ultrasonic technique. Then repeated the steps with MWCNTs and compare their results in an effort to improve experimental conditions that efficiently differentiate the surface of the single walled carbon nanotubes (SWCNTs) and multi walled carbon nanotubesi(MWCNTs) that less nanotubes destroy and to enhance the properties of them and also to reduce aggregation in liquid. the results were prove by XRD, and infrared spectroscopy (FTIR). The FTIR sp

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