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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
Tue Mar 01 2022
Journal Name
Iraqi Journal Of Applied Physics
Fluorescence Characteristics of Coated- Cell Dye Solutions Containing Highly Pure Nanoparticles as Random Gain Media
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In this work, enhancement to the fluorescence characteristics of laser dye solutions hosting highly-pure titanium dioxide nanoparticles as random gain media. This was achieved by coating two opposite sides of the cells containing these media with nanostructured thin films of highly-pure titanium dioxide. Two laser dyes; Rhodamine B and Coumarin 102, were used to prepare solutions in hexanol and methanol, respectively, as hosts for the nanoparticles. The nanoparticles and thin films were prepared by dc reactive magnetron sputtering technique. The enhancement was observed by the narrowing of fluorescence linewidth as well as by increasing the fluorescence intensity. These parameters were compared to those of the dye only and the dye solution

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Publication Date
Wed Dec 12 2018
Journal Name
Iop Conference Series: Materials Science And Engineering
Extraction of Essential Oil from Iraqi<i>Eucalyptus Camadulensis</i>Leaves by Water Distillation Methods
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The extraction of Eucalyptus oil from Iraqi Eucalyptus Camadulensis leaves was studded using water distillation methods. The amount of Eucalyptus oil has been determined in a variety of extraction temperature and agitation speed. The effect of water to Eucalyptus leaves (solvent to solid) ratio and particle size of Eucalyptus leaves has been studied in order to evaluate the amount of Eucalyptus oil. The optimum experimental condition for the Eucalyptus oil extraction was established as follows: 100˚C extraction temperature, 200 rpm agitation speed; 0.5 cm leave particle size and 6:1 ml: g amount of water to eucalyptus leaves Ratio.

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Publication Date
Sun Oct 30 2022
Journal Name
Iraqi Journal Of Science
Anticancer Mechanisms of Zoledronic Acid-Based Graphene Oxide Nanoparticles for Prostate Cancer Bone Metastases Treatment
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     Bone metastases are the main reason for death in males suffering from advanced prostate cancer. This study aimed to create zoledronic acid and graphene oxide conjugation for anticancer therapy. The process of conjugation was confirmed by several characterization methods including UV-VIS spectrophotometry, Fourier Transform Infrared Spectroscopy (FTIR), and atomic force microscope (AFM). the cytotoxicity of 400, 600, and 800 μg/ml to each GO, ZOL, and ZOL-GO was evaluated on a human hepatic cell line (WRL 68) and human prostate cancer cell line (PC3) using an MTT assay. The antitumor mechanisms of ZOL-GO were examined by cell cycle analysis. The results demonstrated That ZOL-GO caused a reduction in the cell viability of WRL 68

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Publication Date
Tue Jun 01 2021
Journal Name
Electric Power Systems Research
Electromagnetic transient modeling of form-wound stator coils with stress grading system under PWM excitation
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The insulation system of a machine coil includes several layers made of materials with different characteristics. The effective insulation design of machine coils, especially in the machine end winding, depends upon an accurate model of the stress grading system. This paper proposes a modeling approach to predict the transient overvoltage, electric field, and heat generation in machine coils with a stress grading system, considering the variation of physical properties in the insulation layers. A non-uniform line model is used to divide the coil in different segments based on material properties and lengths: overhang, stress grading and slot. The cascaded connection of chain matrices is used to connect segments for the representation of the

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Publication Date
Fri Jan 26 2024
Journal Name
Iraqi Journal Of Science
Removal of Iron (Iii) Ion from Aqueous Solution using Polyacrylic Acid Hydorgel Beads as Adsorbent
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This research focuses on the removal and adsorption of Fe (III) ion using a low cost commercial polyacrylic acid hydrogel beads as adsorbent. The effects of time, initial concentration and pH on the metal ion adsorption capacity were investigated. The regeneration of the hydrogel bead and recovery of the metal ion adsorbed were study. The adsorption isotherm models were applied on experimental data and it is shown that the Langmuir model was the best one for Fe (III) ion removal. The maximum capacity was calculated. First-order and second- order kinetic models were used and it is shown that the experimental data was in reliable compliance with the first- order model with R2 value of (0.9935, 0.9011, 0.9695, 0.9912) for all concentrations

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Publication Date
Sat Dec 30 2023
Journal Name
Iraqi Journal Of Science
Screening of bread wheat cultivars (Triticum aestivum L.) to water deficit stress under field conditions
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Field trial was conducted during the growing season of 2011-2012 at the Research
Field, Department of Biology, College of Science, Baghdad University to test the
performance of wheat cv Rabyaa, Latifiya, Al-Iraq, Tummose 2, Abu-Graib 3, IPA
99 and Sham 6 grown under different soil water deficit stresses. Several agronomic
and physiological traits and yield and yield components of the test cultivars were
determined. The experiment was conducted in split plot design with five replications
for each treatment. The cultivars were kept in the sub plot while water stress
treatment was assigned as main plot. Water stress was applied by irrigated the plots
to the soil field capacity (FC) then withheld next irrigation until

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Publication Date
Sun Mar 04 2018
Journal Name
Iraqi Journal Of Science
Improved High order Euler Method for Numerical Solution of Initial value Time- Lag Differential Equations
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The goal of this paper is to expose a new numerical method for solving initial value time-lag of delay differential equations by employing a high order improving formula of Euler method known as third order Euler method. Stability condition is discussed in detail for the proposed technique. Finally some examples are illustrated to verify the validity, efficiency and accuracy of the method.

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Publication Date
Sun Oct 22 2023
Journal Name
Iraqi Journal Of Science
Characteristics of Electrical Power Generation by Wind for Al-Tweitha Location Using Weibull Distribution Function
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In this paper, the 5 minutes measured wind speed data for year 2012 at 10 meter height for Tweitha have been statically analyzed to assess the time of wind turbine electrical power generation. After collection Tweitha wind data and calculation of mean wind speed the cumulative Weibull diagram and probability density function was ploted, then each of cumulative Weibull distribution, cut-in and furling turbine wind speed could be used as a mathematical input parameters in order to estimate the hours of electrical power generation for wind turbine during one day or one year. In Tweitha site, found that the average wind speed was (v= 1.76 m/s), so five different wind turbines were be selected to calculate hours of electrical generation for A

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Publication Date
Sat Jan 01 2011
Journal Name
Iraqi Journal Of Physics
Calculation of Particle Emission Rates for Nucleon-Induced Reactions with non-Equidistance Spacing Model Dependence
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Nuclear emission rates for nucleon-induced reactions are theoretically calculated based on the one-component exciton model that uses state density with non-Equidistance Spacing Model (non-ESM). Fair comparison is made from different state density values that assumed various degrees of approximation formulae, beside the zeroth-order formula corresponding to the ESM. Calculations were made for 96Mo nucleus subjected to (N,N) reaction at Emax=50 MeV. The results showed that the non-ESM treatment for the state density will significantly improve the emission rates calculated for various exciton configurations. Three terms might suffice a proper calculation, but the results kept changing even for ten terms. However, five terms is found to give

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Publication Date
Sun Oct 30 2022
Journal Name
Iraqi Journal Of Science
Automated Methodology for Volume Fraction Measurement of Three Phase Steel Micrograph Using Image Processing Techniques
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     A quantitative description of microstructure governs the characteristics of the material. Various heat and excellent treatments reveal micro-structures when the material is prepared. Depending on the microstructure, mechanical properties like hardness, ductility, strength, toughness, corrosion resistance, etc., also vary. Microstructures are characterized by morphological features like volume fraction of different phases, particle size, etc. Relative volume fractions of the phases must be known to correlate with the mechanical properties. In this work, using image processing techniques, an automated scheme was presented to calculate relative volume fractions of the phases, namely Ferrite, Martensite, and Bainite, present in the

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