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joe-319
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
Sat Apr 01 2017
Journal Name
Iracst – International Journal Of Computer Networks And Wireless Communications (ijcnwc)
Optimizing Network Security Considerations with Transition to IPv6 in University of Baghdad, A Prototype
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It is believed that Organizations around the world should be prepared for the transition to IPv6 and make sure they have the " know how" to be able to succeed in choosing the right migration to start time. This paper focuses on the transition to IPv6 mechanisms. Also, this paper proposes and tests a deployment of IPv6 prototype within the intranet of the University of Baghdad (BUniv) using virtualization software. Also, it deals with security issues, improvements and extensions of IPv6 network using firewalls, Virtual Private Network ( VPN), Access list ( ACLs). Finally, the performance of the obtainable intrusion detection model is assessed and compared with three approaches.

Publication Date
Tue Jun 24 2025
Journal Name
Journal Of Baghdad College Of Dentistry
Interleukine-6 Level in Saliva of Patients with Chronic Periodontitis: A Case-Control Study
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Background:Periodontal diseases are infectious diseases in which periodontalpathogens trigger chronic inflammatory and immune responses. Interleukine-6 is a multifunctional cytokine playing a central role in inflammation and tissue injury.The aim of the study IS to determine the level of Interleukin-6(IL-6) in saliva of patients with chronic periodontitis compared to healthy subjects. Materials and Methods:The total subjects of the present study is 60, divided into 3 groups; 20 patients with chronic periodontitis with pocket depth(PD ≥4 mm)(group I), 20 patients with pocket depth(PD <4 mm) with clinical attachment loss (group II), and 20 healthy controls with pocket probing depth (PPD ≤ 3 mm) without clinical attachment loss (g

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Publication Date
Wed Mar 15 2023
Journal Name
Journal Of Baghdad College Of Dentistry
In vitro assessment of bracket adhesion post enamel conditioning with a novel etchant paste
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Background: 37% phosphoric acid (PA) is the traditional enamel etching technique prior to bracket ‎adhesion, yet it has been implicated in numerous enamel injuries. The purpose of the current study was to create a calcium phosphate (CaP) etching paste in a ‎‎simplified capsule ‎formula that can underpin clinically ‎adequate bracket bond strength ‎without jeopardizing the ‎integrity of enamel upon ‎the debracketing procedure. Materials and Methods: micro-sized hydroxyapatite (HA) powder was mixed with 40% PA solution to prepare ‎experimental acidic CaP paste. Sixty human premolars were ‎assigned into two groups of 30 each. ‎Enamel conditioning was accomplished using 37% PA-gel‎ for control group and CaP paste for e

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Publication Date
Mon Nov 06 2023
Journal Name
Communications In Mathematical Biology And Neuroscience
Effect of hunting cooperation and fear in a food chain model with intraspecific competition
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Taking into account the significance of food chains in the environment, it demonstrates the interdependence of all living things and has economic implications for people. Hunting cooperation, fear, and intraspecific competition are all included in a food chain model that has been developed and researched. The study tries to comprehend how these elements affect the behavior of species along the food chain. We first examined the suggested model's solution properties before calculating every potential equilibrium point and examining the stability and bifurcation nearby. We have identified the factors that guarantee the global stability of the positive equilibrium point using the geometric approach. Additionally, the circumstances that would gu

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Publication Date
Tue Dec 01 2020
Journal Name
Baghdad Science Journal
A Competitive Study Using UV and Ozone with H2O2 in Treatment of Oily Wastewater
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          In this study, ultraviolet (UV), ozone techniques with hydrogen peroxide oxidant were used to treat the wastewater which is produced from South Baghdad Power Station using lab-scale system. From UV-H2O2 experiments, it was shown that the optimum exposure time was 80 min. At this time, the highest removal percentages of oil, COD, and TOC were 84.69 %, 56.33 % and 50 % respectively. Effect of pH on the contaminants removing was studied in the range of (2-12). The best oil, COD, and TOC removal percentages (69.38 %, 70 % and 52 %) using H2O2/UV were at pH=12. H2O2/ozone experiments exhibited better performance compared to

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Publication Date
Sat Dec 30 2023
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Kinetic Modeling of Electromembrane Extraction of Copper using a Novel Electrolytic Cell Provided with a Supported Liquid Membrane
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   The aim of this study is to investigate the kinetics of copper removal from aqueous solutions using an electromembrane extraction (EME) system. To achieve this, a unique electrochemical cell design was adopted comprising two glass chambers, a supported liquid membrane (SLM), a graphite anode, and a stainless-steel cathode. The SLM consisted of a polypropylene flat membrane infused with 1-octanol as a solvent and bis(2-ethylhexyl) phosphate (DEHP) as a carrier. The impact of various factors on the kinetics constant rate was outlined, including the applied voltage, initial pH of the donor phase solution, and initial copper concentration. The results demonstrated a significant influence of the applied voltage on enhancing the rate of c

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Publication Date
Sat Mar 18 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Preparation of Silver Nanoparticles by Sol - Gel Method and Study their Characteristics
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 Powder of silver nanoparticles was prepared by Sol - Gel method successfully using silver nitrate , (AgNO3) gesture is added to sodium citrate (C6H5O7Na3) as a reducing agent and by using  Magnetic Stirrer to mix the solutions and heated then using centrifuge machine to separate the silver nanoparticles from solution .It is then dried in an oven at a temperature 40oC for 24 hours.     Structure characteristics was studied , the synthetic silver powder was prepared through the use of an (XRD). Results showed the composition of silver nanoparticles is a (fcc) and a constant lattice (4.086 ± 0.006 Ã…) by comparing it with standard tables (JCPDS) which is found perfectly matched to file with a number 04-0783, which

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Publication Date
Wed Jul 01 2020
Journal Name
Journal Of Engineering
Improvement the Mechanical Characteristics of Alloy Steel DIN 41Cr4 by Shot Peening
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The effects of shot peening treatment (SPT) were studied at (10,20, and 30) minutes on the rotating bending fatigue behavior and the behavior of the alloy steel DIN 41Cr4 vibrations. The hardness test, tensile test, constant amplitude fatigue tests, and the vibration measurements were performed on samples with and without cracks at room temperature (RT), also, the fracture surface was examined and analyzed by a Scanning Electron Microscope (SEM). The results of the investigations, for example, Stress to Number of cycles to failure (S-N) curves, fatigue strength improvement factor of 5% to 10%, the decreasing percentage of maximum Fast Fourier Transform (FFT) acceleration of the shot-peened condition were compared to untr

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Publication Date
Thu Apr 02 2020
Journal Name
1st International Conference In Physical Science And Advance Materials
Structural and Morphological Characteristics of Organic and Inorganic Blend Heterojunction NiPcTs/Cd
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In the present study NiPcTs, CdS thin films, and Blends of NiPcTs:CdS were prepared with 1:2 content mixing ratio of NiPcTs to CdS solutions. Cadmium chloride and thiourea were used as the essential materials for deposition CdS thin films while using organic powder of NiPcTs to deposit NiPcTs nanostructure films. The spin-coating technique was employed to fabricate the NiPcTs , CdS films and NiPcTs-CdS blend. Structural properties of films have been investigated via X-Ray diffraction(XRD),and show that thin films of NiPcTs, and CdS have monoclinic and polycrystalline hexagonal structure respectively while the blend has two polycrystalline structure with cubic and hexagonal phases. Atomic force microscope (AFM) confirmed that the surf

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Publication Date
Mon Jul 01 2024
Journal Name
Journal Of Optics
Optical and structural characteristics of carbon quantum dots manufacturing by electrochemical method
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Electrochemical method was used to prepare carbon quantum dots (CQDs). Size of matter was nature when evaluate via X-ray diffraction (XRD). A distinct peak at 2θ equal to 31.6° and three other small peaks at 38.28°, 56.41° and 66.12° were observed. The measures of Fourier Transform Infrared Spectroscopy (FTIR) showed the bonds in the transmittance spectrum are manufactured with carbon nanostructures in view. The first peaks are the O–H stretching vibration bands at (3417 and 2922) cm−1, (C–O–H at 1400, and 1317) cm−1, (C–H), (C=C), (C–O–H), (C=O), and (C–O) bonds at 2850, 1668, 1101, and 1026 cm−1 sequentially. The transmission electron microscopy (TEM) results presented that the spherical CQDs are in shape and on a

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