Table of content

ALNAHRAIN JOURNAL FOR ENGINEERING SCIENCES

مجلة النهرين للعلوم الهندسية

ISSN: 25219154 / eISSN 25219162
Publisher: Al-Nahrain University
Faculty: Engineering
Language: Arabic and English

This journal is Open Access

About

AlNhrain Journal for Engineering Sciences is a refereed scientific engineering journal published by the College of Engineering, Nahrain University two times per year. The journal publishes the scientific output of researchers from Iraq and abroad in the fields of architectural, chemical, civil, computer, electrical, information technology, laser and optoelectronics, mechanical and medical engineering as well as in related fields. Papers written in Arabic and English are accepted and they are subjected to proper evaluation and accordingly classified as follows:
• Original research papers and papers on novel design, analysis or construction methods of great value to the engineers which include basic and practical results.
• Short communications or short discussions on papers which have already appeared in the journal provided that whose text should not exceed 800 words.

The material of the paper should not violate any intellectual property right of any person or entity and should not contain any subject matter that contravenes any laws and should meet ethical standards applicable to the research discipline.

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Contact info

Editor-in-Chief
College of Engineering Journal
Al-Nahrain University
P.O. Box 64040 , Al-Jadyriah
Baghdad-Iraq.
e-mail: journal.engineering@nahrain-eng.org
jourengnah@gmail.com
Phone: +964 (0) 7817 202 662

Table of content: 2013 volume:16 issue:1

Article
Speech Denoising Using Mixed Transform
إزالة الضوضاء من الصوت باستخدام التحویلات الخلیطة

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Abstract

This paper presents a mixed transform based speech denoising technique obtained by the combination of multicircularlet and slantlet transforms and thresholding algorithm. It is well known that denoising is a compromise between the removal of the largest possible amount of noise and the preservation of signal integrity. Mixed transform is an intelligent tool for solving speech processing problems such as speech denoising , the general algorithm of speech denoising using discrete wavelet transform (DWT) is presented, followed by the proposed general algorithm of speech denoising using mixed transform. This paper also discusses the effect of using DWT and mixed transform in speech denoising, theirperformances in terms of mean square error (MSE) and peak signal to noise ratio (PSNR) are assessed. Computer simulation results indicate that the mixed transform offers better MSE and PSNR than DWT.


Article
Free Vibration Characteristics of Elastically Supported Pipe Conveying Fluid

Authors: Ali H.Al-Hilli
Pages: 9-19
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Abstract

In this study, the effect of support values on the natural frequency and critical flow velocity of a straight pipe conveying laminar flowing fluid is studied. The aim of this work is deriving a new analytical model to perform a general study to investigate the dynamic behavior of a pipe under general boundary conditions by considering the supports as compliant material with linear and rotational springs. This model describes both the classical (simply support, free, built, guide) and the restrained boundary condition and it is not required to derive a new frequency equation if the boundary conditions is changed ,also the result will be near to reality by knowing the physical parameters for the compliant material and the pipe.


Article
Experimental and numerical investigation of heat transfer and flow characteristics for tractor heat exchanger (radiator)
التحلیل العددي والتجریبي لانتقال الحرارة ودراسة الجریان لمبادل حراري في جرار زراعي

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Abstract

An experimental and numerical study was carried out to investigate heat transfer and flow characteristics through the tractor heat exchanger (radiator). The engine of the tractor is Diesel (compression ignition) engine type. The experimental study used heat exchanger (radiator) manufactured from copper instead of the original heat exchanger of the tractor, which is manufactured from iron. Both heat exchangers consist of circular cross sectional tubes and plate fins. The temperatures was measured inside the cooling room of engine for both cases at the same time and the same loads. The results of the experimental investigation showed that the heat exchanger is manufactured from copper provided temperatures less than the heat exchanger manufactured from iron, that means heat rejected by copper heat exchanger is more than heat rejected by iron heat exchanger. The use of copper heat exchanger is better than iron heat exchanger for cooling the tractor engine. In the numerical study used model of copper heat exchanger to analyzed by CFD method at different air velocity from (0.5 m/sec) to (7 m/sec) for laminar air flow. The object of this study was enhancement the heat transfer process from the cooling fluid of heat exchanger. The results of the numerical study shows that heat transfer rate increase with increasing air flow during heat exchanger (radiator). Good agreement between experimental and numerical results is obtained

Keywords

heat exchanger --- cooling --- fluid --- temperature --- copper --- iron --- tube --- fins


Article
Study of Intrinsic Viscosity and Flow Activation Energy of Some Polymers in Different Solvents

Authors: Talib B. Kashmoula
Pages: 30 -40
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Abstract

The intrinsic viscosity has been studied for several polymers which are used in some industrial applications, such as polyisobutylene of types Oppanol B150, 200, and 250 with different molecular weights of 2.5, 4.1 and 5.9 million g/mole, respectively, which dissolved in crude and gas oil. In addition three types of additives brought from Al-Dura refinery, olefin copolymer (OCP), {viscoples-4-677, viscoplex-215496, and Lubrizol R 7077} which dissolved in crude oil, and the polymers which is soluble in water such as polyacrylamide with high molecular weight and xanthan gum with molecular weight 3.7 million g/mole where also studied. It was found that the intrinsic viscosity of polyisobutylene decrease as the temperature increase in crude and gas oil. The olefin copolymer (Viscoplex-4-677) showed the same behavior as polyisobutylene where it can be used as drag reduction agent. It was noted that neutral polymers as well as polyelectrolytes could be used as drag reduction agent.


Article
Studying the Factors Affecting the Settling Velocity of Solid Particles in Non-Newtonian Fluids
دراسة العوامل المؤثرة على سرعة الاستقرار بأستخدام الموائع غیر نیوتونیة

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Abstract

The aim of this research is to study the factors affecting the settling velocity (V S ) in Non- Newtonian fluids which are the rheological properties, concentrations of non-Newtonian fluids, particle shape and size. An experimental apparatus was designed and built, which consists of Perspex pipe of length of 160 cm. and inside diameter of 7.8 cm. to calculate the settling velocity, also electronic circuit was designed to calculate the falling time of particles through fluid. Two types of solid particles were used; glass spheres and crushed rocks as irregularly shaped particles with different diameters and compared with each other. The concept of equivalent spherical diameter (D S ) was used to calculate the diameters of irregularly shaped particles. The settling velocity was calculated for Non-Newtonian fluids which represented by Power- Law fluid. Two types of polymers were used, Carboxy Methyl Cellulose with concentrations of (3.71, 5, 15 and 17.5) g/l and polyacrylamide with concentrations of (2, 4 and 6) g/l. The results showed that the settling velocity decreased when fluid becomes far from Newtonian behavior (flow index n decreased) and also when concentrations of polymer solutions increased, also, the settling velocity increased with particle diameter or volume. Three sets of equations were concluded; the first relates settling velocity with flow index (n), the second relates settling velocity with concentrations, and the third relates settling velocity with particle diameter


Article
Enhancement of Heat Transfer in The Tube-Sid of A Double Pipe Heat Exchanger by Wire Coils
تحسين انتقال الحرارة في أنابيب سيد من انبوب باستخدام محلزنات سلكية

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Abstract

Heat transfer enhancement by wire coils is adopted in order to increase the thermal performance of a double pipe heat exchanger. The heat exchanger adopted is 1245 mm effective length, 28 mm outer diameter and changeable inner diameter (11 or 14 mm). Wire coils of e = 1 mm and p = 10, 20, 30 and 40 mm are used as turbulence promoters to augment heart transfer inside the inner tube at a Reynolds number range of 5000 to 40000. Water is used as the working fluid in the two sides. Variation in the experimental conditions is attained by changing the mass flowrates of unenhanced side and changing the inlet temperature of hot fluid. These conditions are followed in order to have as large amount of data points as possible in addition to observe the effect of changing these conditions. Heat transfer is increased inside the inner tube by 2.43 folds, as compared to empty tube at the same Reynolds number accompanied by friction factor increase of 4.75 folds. New correlations of Nusselt number and friction factor for the enhanced tubes are proposed as functions of Reynolds number, Prandtl number and the geometrical characteristics of inserts and tube sizes.

Keywords


Article
Treatment of radioactive liquid waste using Iraqi geological raw materials and zeolite
معالجة النفايات السائلة المشعة باستخدام مواد جيولوجية خام عراقية و الزيولايت

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Abstract

A radioactive liquid waste contaminated with cesium-137 was found underneath a destructed radioactive waste treatment station in Tuwaytha site 25 km south of Baghdad - Iraq. The appropriate sorbent materials found for the removal of radio cesium-137 were bentonite and modified bentonite with corresponding removal efficiencies of 85% and 91.8% respectively. The favorable batch experimental conditions were found to be 800 rpm stirring speed, 200 mg sorbent mass, 45µm sorbent particle size, and solution temperature of 30 oC for an initial radio cesium concentration of 0.44 mg/l. The BET isotherm model was found to represent the experimental results very well.


Article
Treatment of radioactive liquid waste using Iraqi geological raw materials and zeolite
معالجة النفايات السائلة المشعة باستخدام مواد جيولوجية خام عراقية و الزيولايت

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Abstract

A radioactive liquid waste contaminated with cesium-137 was found underneath a destructed radioactive waste treatment station in Tuwaytha site 25 km south of Baghdad - Iraq. The appropriate sorbent materials found for the removal of radio cesium-137 were bentonite and modified bentonite with corresponding removal efficiencies of 85% and 91.8% respectively. The favorable batch experimental conditions were found to be 800 rpm stirring speed, 200 mg sorbent mass, 45µm sorbent particle size, and solution temperature of 30 oC for an initial radio cesium concentration of 0.44 mg/l. The BET isotherm model was found to represent the experimental results very well.


Article
Design of a two-Degree-of-Freedom Controller for a Magnetic Levitation System Based on LQG Technique

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Abstract

A new control design procedure has been proposed in this paper based on the LQG control design. A two degree of freedom controller with integral action is obtained and tested on the magnetic levitation system, which is a good test-bed for control design because of its nonlinearity and unstability with practical uses in high-speed transportation and magnetic bearings. Simulations are performed under MATLAB environment and included to highlight that the proposed controller accurately achieves position tracking for different kinds of reference inputs.


Article
High Speed Tracking System Using Single Chip FGPA
نظام تتبع عالي السرعة باستخدام رقاقة FGPA

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Abstract

The main contribution of this paper to describes and implements the Castella tracking system (CTS) in high volume Field Programmable Gate Arrays (FPGA) devices, which presents the complete design of an adaptive two-state Kalman tracking filter that is suggested by Castella to track the maneuvering and nonmaneuvering targets using FPGA. The basic design for this system required a very high cost lie out of range of FPGA capacity. This paper will present a novel approach to reduce the cost of this system. The new method depends on the reduction of the width of data bus of the system without reduction the accuracy of the system. However the novel approach will reduce the cost to about 10% from the original cost to implement the system in a single chip FPGA. Finally, two simulation scenarios are also given to illustrate the efficiency of this adaptive filter comparing with the conventional Kalman filter.


Article
Wavelet Packet Assisted Genetic Algorithm Based ISI-ICI Suppression for OFDM Systems

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Abstract

In this paper, the behavior of Wavelet Packet-Orthogonal Frequency Division Multiplexing (WP-OFDM) system based on Genetic Algorithm (GA) to mitigate both the Inter-Symbol Interference (ISI) created by a channel with longer impulse response duration than that of the Cyclic Prefix (CP)as well as the Inter-Carrier Interference (ICI) resulting from high Doppler spreads is investigated. This is realized by simulation environment to utilize the advantages of modeling programs. In this simulation, Wavelet Transforms (WT) have been considered as alternative platforms for replacing Inverse Forrier Transform (IFFT) and FFT; all are programmed using MATLAB package. The simulation result shows that the ICI (ISI) power is significantly reduced. In this investigation,the effectof delay spread with 16-QAM and QPSK modulation schemes was studied. Results also show that our model, genetic based WP-OFDM, is superior as compared to WP-OFDM.

Keywords

OFDM --- GA --- WP --- WT --- ISI --- ICI.


Article
Design and Implementation Iris Recognition System Using Texture Analysis

Authors: Ali A.Ibrahim --- Hussein J.Oda
Pages: 98-101
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Abstract

The aim of this work is to produces a technology of recognition and identifies of the person by using the iris. The work was started by reading the images of eyes (UBIRIS database). After that, the iris region localized from the eye image by using the method of image processing. The iris shape is circular so it transfer to rectangular shape and enhance the image and remove the noise like eyelashes and flash of the camera. Then the image quantized from 256 grey levels to 16 grey levels. Four statistical functions used because these functions give us accurate description of iris, the samples had been taken in four angles. The information for each sample is save in database. The last stage is to classify the samples by using neural network. The results will prove that the work have high accurate conclusions.

Keywords


Article
A solution to Enhance VPN effect on wireless network Performance
إستخدام جودة الخدمة اللاسلكية للتقليل من تأثير الشبكة الخاصة الظاهرية على إداء الشبكة المحلية اللاسلكية

Authors: Subhi Aswad --- Muhanad Qasim مهند قاسم
Pages: 102-110
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Abstract

This work presents a design of secured Wireless Network by utilizing Virtual Private Network (VPN) technique and provides a solution to enhance its performance by using Wireless Quality of Service technique (WQoS).A set of parameter are investigated include delay, throughput, jitter round trip time. These parameters are checked for a WLAN without VPN and WQoS, WLAN with VPN, and WLAN with VPN and WQoS.


Article
Investigating of A Modified Model for Human Eye Movement

Authors: Sadiq Jafer Abbass --- Sheelan Kameran Baker
Pages: 111-124
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Abstract

In this research a biological model was modified upon a homomorphic sccadic eye movement model by adding and calculating the mass of eye and the elasticity of eye tendon and take a primary position only. According to this modification, equation with six order was appeared which was processed with a MATLAB SIMULINK to get a desire results of theta, velocity and acceleration in the normal case. For the same model, a disease was estimated to evaluate the results of theta and how it is affected by this disease which was estimate the increase and decrease happened in the primary elastic element and viscosity. After theta controller was added to the model to control the system and get the desire angle which is equal to 15º in the normal case while in the system with disease, the PI controller that used can control only the system during normal case while in the system with disease, the PI controller could not control the system to get the desired angle.

Keywords

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