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Numerical Investigation of Drag Reduction Techniques in a Car Model
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Abstract<p>Reducing the drag force has become one of the most important concerns in the automotive industry. This study concentrated on reducing drag through use of some external modifications of passive flow control, such as vortex generators, rear under body diffuser slices and a rear wing spoiler. The study was performed at inlet velocity (V=10,20,30,40 m/s) which correspond to an incompressible car model length Reynolds numbers (Re=2.62×10<sup>5</sup>, 5.23×10<sup>5</sup>, 7.85×10<sup>5</sup> and 10.46×10<sup>5</sup>), respectively and we studied their effect on the drag force. We also present a theoretical study finite volume method (FVM) of solving Reynolds-averaged Navier-tokes equations (RANS) using a realizable k–epsilon (k-ε) turbulence model, conducted on a car, model KIA Pride, which is popular in Iraq and Iran. All computational analysis and modifications were carried out using the ANSYS Fluent 19 computational fluid dynamics (CFD) software and SOLIDWORKS 2018 modeller. The drag coefficient of the analysed car was found to be 0.34 and the results show that the drag can be reduced up to1.73% using vortex generators, up to 3.05% using a rear wing spoiler and up to 2.47% using rear under-body diffuser slices modifications, whereas it may be reduced up to 3.8% using all previous modifications together.</p>
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Publication Date
Wed May 01 2019
Journal Name
Journal Of Engineering
Reduced Complexity SLM Method for PAPR Reduction
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In this paper, the computational complexity will be reduced using a revised version of the selected mapping (SLM) algorithm. Where a partial SLM is achieved to reduce the mathematical operations around 50%. Although the peak to average power ratio (PAPR) reduction gain has been slightly degraded, the dramatic reduction in the computational complexity is an outshining achievement. Matlab simulation is used to evaluate the results, where the PAPR result shows the capability of the proposed method.  

 

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Publication Date
Wed Aug 31 2022
Journal Name
Sciencerise: Pharmaceutical Science
The morphological analysis of crystalline methadone: a novel combination of microscopy techniques
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The aim: to evaluate combined microscopy techniques for determining the morphological and optical properties of methadone hydrochloride (MDN) crystals. Materials and methods: MDN crystal formation was optimized using a closed container method and crystals were characterized using polarized light microscope (PLM), scanning electron microscopy (SEM) and confocal microscopy (CM). SEM and CM were used to determine MDN crystal thickness and study its relationship with crystal retardation colours using the Michel-Levy Birefringence approach. Results: Dimensions (mean±SD) of diamond shaped MDN crystals were confirmed using SEM and CM. Crystals were 46.4±15.2 Vs 32.0±8.3 µm long, 28.03±8.2 Vs 20.85±5.5 µm wide, and 6.62±

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Publication Date
Fri Jan 01 2021
Journal Name
Journal Of Engineering
A Computational Fluid Dynamics Investigation of using Large-Scale Geometric Roughness Elements in Open Channels
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The hydraulic behavior of the flow can be changed by using large-scale geometric roughness elements in open channels. This change can help in controlling erosions and sedimentations along the mainstream of the channel. Roughness elements can be large stone or concrete blocks placed at the channel's bed to impose more resistance in the bed. The geometry of the roughness elements, numbers used, and configuration are parameters that can affect the flow's hydraulic characteristics. In this paper, velocity distribution along the flume was theoretically investigated using a series of tests of T-shape roughness elements, fixed height, arranged in three different configurations, differ in the number of lines of roughness element

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Publication Date
Sat Jul 01 2023
Journal Name
Journal Of The Faculty Of Medicine Baghdad
The effectiveness of intense pulsed light (home use) device in facial hair reduction
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Background: Intense pulsed light (IPL) devices produce polychromatic incoherent high-intensity pulsed light with a specified wavelength spectrum, fluence, and pulse duration through the use of flashlamps and bandpass filters. Similar to lasers, IPL devices operate on the selective photothermolysis principle, with melanin acting as the chromophore. Despite this similarity, they are constructed differently and produce different amounts of light Aim of the study: To investigate the efficacy of IPL home-use device in hair reduction technique for women with unwanted facial hair. Subjects and methods: The study was conducted in Baghdad on forty-five female subjects with Fitzpatrick skin phototype (II to IV) and black, brown hair in a period of ei

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Publication Date
Mon Mar 23 2020
Journal Name
Journal Of Engineering
Experimental Investigation of Thermal Performance of a Solar Chimney Provided with a Porous Absorber Plate
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Experimental investigation of the influence of inserting the metal foam to the solar chimney to induce natural ventilation are described and analyzed in this work. To carry out the experimental test, two identical solar chimneys (without insertion of metal foam and with insertion of metal foam) are designed and placed facing south with dimensions of length× width× air gap (2 m× 1 m× 0.2 m). Four incline angles are tested (20o,30o,45o,60o) for each chimney in Baghdad climate condition (33.3o latitude, 44.4o longitude) on October, November, December 2018. The solar chimney performance is investigated by experimentally recording absorber pl

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Publication Date
Sun Jul 09 2023
Journal Name
Journal Of Engineering
PAPR Reduction of OFDM Signals Using Clipping and Coding
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The problem of the high peak to average ratio (PAPR) in OFDM signals is investigated with a brief presentation of the various methods used to reduce the PAPR with special attention to the clipping method. An alternative approach of clipping is presented, where the clipping is performed right after the IFFT stage unlike the conventional clipping that is performed in the power amplifier stage, which causes undesirable out of signal band spectral growth. In the proposed method, there is clipping of samples not clipping of wave, therefore, the spectral distortion is avoided. Coding is required to correct the errors introduced by the clipping and the overall system is tested for two types of modulations, the QPSK as a constant amplitude modul

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Publication Date
Sun Jan 01 2012
Journal Name
International Journal Of Cyber-security And Digital Forensics (ijcsdf)
Genetic Algorithm Approach for Risk Reduction of Information Security
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Nowadays, information systems constitute a crucial part of organizations; by losing security, these organizations will lose plenty of competitive advantages as well. The core point of information security (InfoSecu) is risk management. There are a great deal of research works and standards in security risk management (ISRM) including NIST 800-30 and ISO/IEC 27005. However, only few works of research focus on InfoSecu risk reduction, while the standards explain general principles and guidelines. They do not provide any implementation details regarding ISRM; as such reducing the InfoSecu risks in uncertain environments is painstaking. Thus, this paper applied a genetic algorithm (GA) for InfoSecu risk reduction in uncertainty. Finally, the ef

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Publication Date
Sun Mar 30 2003
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Reduction of Aromatic Content from Hexane by Silica Gel
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Publication Date
Sun Apr 01 2018
Journal Name
Journal Of Economics And Administrative Sciences
The influence of human resources Accounting on cost reduction
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The development of human resources training programs has an applied and important role in the preparation of human cadresin terms of capacity to absorb technical sciences and skills and scientific and practical practices at faster rates in order to bealighed with continous development. Hence the recognition of the significant role that human resources play in the economy of any country,which has stressed the interest towards the economic unity of the qualified staff that it needsin atimely manner through the ongoing training process in the era of high technology day by  day  In this regard ,the current research deal with accounting of human resources and its impact on reducing costs in the military establishment and the

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Publication Date
Mon Sep 16 2019
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Spectrophotometric Determination of some Drugs using Oxidation Reduction Reactions
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     A spectrophotometric method is proposed for the determination of some drugs containing amino group such as mesalazine, metoclopramide and dopamine in pharmaceutical formulations. It was simple, precise, accurate, rapid, and based on the oxidation of each drug with chromate as an oxidizing agent in the presence of 1N hydrochloric acid. Then indigo carmine is reacted with residual chromate in the presence of a catalysis factor (sodium oxalate). Increasing in absorbance's value of the color system is proportional to the amount of the three drugs which is measured at the selected wavelength of 610 nm.

The proposed method is obeying Beer's law in the ranges of (1-40, 2-44 and 2-52) ppm for the concentration of

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