Print ISSN: 1681-6900

Online ISSN: 2412-0758

Volume 31, Issue 11

Volume 31, Issue 11, July 2013, Page 149-2211

Effect of Orifice Shape and Bore-Area on Noise Attenuation in a Reactive Muffler

Muna S. Kassim; Ehsan S. Ameen; Hayder M. Mohammed

Engineering and Technology Journal, 2013, Volume 31, Issue 11, Pages 2014-2029

IC engines are a major source of noise pollution. Mufflers require specific design and construction. Considering various noise parameters produced by the engine,the conventional design does not include much of a parametric noise analysis or other engine characteristics. In this study, a muffler for internal combustion engine has been designed and manufactured. The performance characteristic and the effect on transmission losses are investigated for different types of orifice plates (circle and Square rectangle, triangle) with different bore areas and frequency. Agood agreement with other works is obtained where the triangular bore shape orifice with minimum bore area is found to be the most effective.

Mechanical Properties of Friction Stir Welded Aluminum Alloy with Butt and Lap Cases

Nadhim M.Faleh

Engineering and Technology Journal, 2013, Volume 31, Issue 11, Pages 2030-2038

Mechanical properties were investigated in base and friction stir linear welds of 7075 aluminum alloy. Welding tools consist of a shoulder with a pin and with-out pin. This work addresses the effects of tool geometry on tensile stress and shear strength of butt and lap welds, and comparing with base material. Also, the effects of process condition on the strength of friction stir processed material are quantitatively characterized. Compared to the butt case, the friction stir lap linear welds, with pin, leads to a 20% increase in optimized weld strength with 1000 rpm of tool revolutions and 200 mm/min of tool speed. The optimizing of operating conditions primarily leads to a 15% increase in optimized weld shear strength, with 1000 rpm of tool revolutions and 200 mm/min of tool speed.

Studying the Effect of Both Gas Oil and Diesel Fuel on Polypropylene-Polycarbonate Reinforcement with Carbon Black

Najat J. Saleh; Abbas A. Jawad

Engineering and Technology Journal, 2013, Volume 31, Issue 11, Pages 2039-2054

In the present research, the diffusion of prepared sample blends (PP/PC) unfilled-filled with different amounts of carbon black (2 – 7) wt% and at different temperatures (25oC, 40oC and 55cC) were studied. Absorption test was carried out in (Gas-Oil and Diesel-Fuel) at different immersion times as: Two equations were used to calculate the diffusion coefficient values. In the first equation , the diffusion coefficient values ranged from (0.252 to1.619) cm2/sec for immersed in Gas-Oil and it ranged from (0.321 to 1.783) cm2/sec for immersed in Diesel-Fuel. In the second equation the diffusion coefficient values ranged (0.37 to 2.649) cm2/sec for immersed in Gas-Oil and it ranged from (0.562 to 2.635) cm2/sec for immersed in Diesel-Fuel. It was found that the results obtained by the two equations were approximately the same. Indeed the blend (PP/PC) filled with (4 wt%) of carbon black has the lowest values of diffusion coefficient (calculated by the above two equations) in Gas-Oil and Diesel-Fuel which indicates this sample has better performance than other samples. The diffusion test also was carried out at different temperatures in order to show the effect of temperature on diffusion coefficient. It was found that the diffusion coefficient values increase with increasing temperature. All these samples are obeyed Fickian behavior and the activation energy (E) increases with increasing amounts of carbon black (2 – 7) wt%.

A Design Study and Performance Prediction of an Internal Compression Supersonic Air Intake

Bahjat Hassan Alyas

Engineering and Technology Journal, 2013, Volume 31, Issue 11, Pages 2055-2075

The aim of this research is to carryout a design study on a variable geometry rectangular supersonic air-intake at different flight conditions. The design of the air-intake at supersonic Mach number according to “on-design” condition ( ), to get a maximum total-pressure recovery, and study the performance of air-intake at supersonic Mach number according to “off-design” conditions ( ). The air-intake consists of convergent-divergent nozzle. The number of oblique shock waves is induced by the sharp cowl lips at the nozzle entrance and their reflections may continue along the convergent passage depending on the free-stream Mach number and nozzle wall turning angle. The location of the normal shock wave is just downstream the throat, for an “off-design” condition, and at nozzle throat, at its “on-design” condition [21]. The flow is assumed as one-dimensional compressible, and inviscid. The flow properties were calculated using the analytical method based on the relation of the oblique shock and normal shock waves. The divergent part was analyzed for different divergent lengths, to maintain the divergent angle less than value that causes flow separation and to get the maximum total pressure recovery. The convergent part was analyzed for different convergent lengths, to maintain the oblique shock and their reflected terminated before the throat position to get maximum total pressure recovery, [21].

Accuracy Assessment of 2D and 3D Geometric Correction Models for Different Topography in Iraq

Abdul Razzak T. Ziboon; Israa H. Mohammed

Engineering and Technology Journal, 2013, Volume 31, Issue 11, Pages 2076-2085

In recent decades, Remote sensing data becomes one of the basic information required for mapping and different applications in geomatics. In this research, different mathematical models in 2D and 3D cases are investigated and comprised in order to assess the accuracy of these models under different conditions of terrain topography. Three high resolution satellite QuickBird images of three different study areas, with respect to their topography have been used in this work. In this research, the 2D mathematical models which were used, 1st, 2nd order polynomial, and projective transformation model while, the 3D mathematical models used were, 1st, 2nd order 3D polynomial, and direct linear transformation model. All these methods are applied for each study area and evaluated through the Matlab environment facilities

Design and Implementation of MC-CDMA Technique Using FPGA

il A. H. Hadi; Layla Hattim Abood

Engineering and Technology Journal, 2013, Volume 31, Issue 11, Pages 2085-2097

Multicarrier Code Division Multiple Access (MC-CDMA) is attractive technique for high speed wireless data transmission; it's a combination of Orthogonal Frequency Division Multiplexing (OFDM) and Code Division Multiple Access (CDMA). OFDM employs a number of orthogonal subcarriers, this increases the symbol duration while the CDMA technique provides high capacity over other conventional multiple access schemes. In this paper discusses implementation of base band MC-CDMA system using the FPGA technique, all modules are designed using VHDL programming language. The electronic functional performance of designed circuits is tested by simulations using VHDL programming language on XILINX ISE 9.2i. The proposed model is designed using (Fast Fourier Transform/ Inverse Fast Fourier Transform) and the spreading code used is the gold code, the implementation of the proposed model using Spartan-3A/3AN, XC3S700N-3FGG484 FPGA of Xilinx family.

Drinking Water Quality for Al-Mustansiriya University

Faaeza Ahmed Abd Al-Kareem

Engineering and Technology Journal, 2013, Volume 31, Issue 11, Pages 2098-2115

The aim of the research is to study water quality in Al-Mustansiriya university, which is supplied by water through a4 inch diameter pipe, water collected in a very old ground tank supplying water to the university departments which have their only tanks.
Samples of water from the main pipe and for each department in the university were taken for seven months (Jan. 2011 -Jul. 2011) Physical, chemical and bacteriological tests have been done.
Residual chlorine reduced as the temperature increased during the year .Samples from Arabic language department show the less residual chlorine content. Turbidity readings did not apply to the Iraqi and WHO standards because the ground tank contains large amount of sediments and was not cleaned for a long time , maximum turbidity reading was 6.8 NTU.
The samples were analyzed also to find the chemical properties such as heavy metals (Fe, Cu, Pb, Zn) and other parameters of water (TDS, CL, Na, S.S, pH, Mn, Ca) .Iron was the heavy metal which was found in large concentrations that exceeded the Iraqi and WHO standards because of the corrosion inside the ground tank, maximum iron reading was 8.4 mg/l. The percent of samples exceeding the standard limits for sodium, sulphate, chloride, hardness 55, 9.04, 6.19, and 5.71 % respectively.
Bacteriological examinations of water (total coli form, E coli, and total plate count) show good results although some bacteria were detected but still within the allowable limits, this is attributed to the present of residual chlorine and the continuous feeding of water supply due to high consumption of water.

Design and Simulation of Optical Filter for Dense Wavelength Division Multiplexing (DWDM) System

Aseel Abdulameer Shakaty

Engineering and Technology Journal, 2013, Volume 31, Issue 11, Pages 2116-2127

In this paper, it is demonstrated, by means of simulations, the practical feasibility of an interference filter, implemented from a stack of high and low index birefringent thin films that can be used as transmission filter. Simulations were carried out with a software toolbox package implemented as Matlab™ m-files. The simulation is done by using the following linear material (AgB, ZnSe, KF2, GaAs, BaF2, TiO2) as coating material with single FBR (fabry perot resonator) structure , and KB7 glass as substrate material. Result show that difference between the values of refractive index of multi layer stack has great influence on the transmittance value, the largest possible value is the best choice for obtaining nearly 100% transmittance for the designed wavelength taken and this clearly observed in the simulation figures. In addition, Number of antireflection layer (N) effect clearly on the result, the design parameter that take GaAs as high refractive index material and BaF2 as low index material with N=4 represent good approach to the desired value for the simulated filter that’s used in (DWDM) .

PSO-FL Controller of Separately Excited DC Motor

Hawraa Q. Hameed

Engineering and Technology Journal, 2013, Volume 31, Issue 11, Pages 2128-2140

This paper presents an application of highbrid controller of a Separately Exited DC Motor (SEDM) using PSO-FL techniques. The controller is designed depending on fuzzy logic rules are such that the systems are fundamentally robust. These rules have capability learning, can learn and tune rapidly, even if the motor parameters are varied. But, adapting fuzzy controller parameters is very complex and depends on operator experience. Therefore a Particle Swarm Optimization technique was adapted for obtaining the centers and the width of triangle inputs membership functions. The FL method is represented too. The complete mathematical model and simulation of a separately excited dc motor is represented using MATLAB10a/SIMULINK. The simulation results demonstrate that the proposed PSO-FL speed controller realizes a good dynamic behavior of the SEDM with very good speed tracking.

Real Time System Used to Improve the Production and Quality of Mushroom

Omar Nameer M. Salim

Engineering and Technology Journal, 2013, Volume 31, Issue 11, Pages 2141-2156

Mushroom is one of agricultural products that are in increasing demand several folds in recent years so, mushroom cultivation represents important income source for farmers and countries. This paper proposed a real time system used to monitor and control environmental parameters for mushroom cultivation. Modern module SH-1000-DTH used as sensing system to measuring environmental parameters (Temperature, Relative Humidity, and CO2 concentration). Visual basic language was used to design and implement a control program responsible for processing data from sensing system and makes a decision to operate one of the mend environment system devices according to the program stored database. The control program was designed to make the system work either automatically or manually to give the user more flexibility in his work and also designed in away makes dealing with it easy and simple. Results obtained when this system tested show increasing in production about 46% and increasing in product quality when compared with the traditional production without using this system.

Implementation of Golay Complementary Code Sequences Generator Based on FPGA

Dhamyaa H. Mohammed

Engineering and Technology Journal, 2013, Volume 31, Issue 11, Pages 2157-2165

Golay sequences have some properties make it distinctive in the applications and results. However, for this distinction must select the code sequences carefully and accurately. Therefore, to satisfy these requirements, a creation algorithm must be easy, accurate and powerful. In this paper, an FPGA based, design and implementation of Golay complementary code sequence(GCCS) creation and then made autocorrelation between their pair codes to verify properties. The process time for proposed algorithm is less than that for all possible algorithm by (1/4 to 1/1024 for 4-bit to 16 bits respectively). Thus, the Search can be regarded as pioneers of the research application of this technique to the subject and got good results. The Implementation was based on 8-bit pair code and made by Xilinx-spartan-3A XC3S700AFPGA, with 50 MHz internal clock.

Study of Short Cracks Growth Behavior for Duralumin 7075- T6 Enhanced by Artificial Ageing as Thermal and Chemical Treatments Under Rotating Bending Loading

Mustafa Sami Abdullateef

Engineering and Technology Journal, 2013, Volume 31, Issue 11, Pages 2166-2182

The fatigue life of ductile metals is controlled mainly by the propagation life of a short surface crack; to clarify the growth behavior of short cracks is crucial factor to the safe design of smooth surface members. However, little has been reported on the growth behavior of short surface cracks in thermal-chemical treated duralumin. In the present study, stress-controlled fatigue tests (under rotating bending load) for 70 hours artificial aged duralumin 7075-T6 without chemical treatment case (1) and with chemical treatment case (2). The growth behavior of short cracks was monitored by a plastic replication technique and the surface damage (short crack propagation) during cyclic stressing was observed by optical microscopy. The physical background of fatigue damage for case (1) and case (2) was discussed from the viewpoints of the initiation and growth behavior of short cracks.

Computer Simulation Using Fuzzy LogicModel to Predict Hot Corrosion Kinetics in Molten Salt of Steel-T21 Coated by Simultaneous Yttrium-Doped Aluminizing-Siliconizing Process

Abbas Khammas Hussein

Engineering and Technology Journal, 2013, Volume 31, Issue 11, Pages 2183-2197

The present paper describes fuzzy logic simulation of an experimental study on the behavior of hot corrosion in molten salt (Na2SO4) of steel-T21 coated by simultaneous yttrium-doped aluminizing-siliconizingprocess . Diffusion coating was carried out at 1050oC for 6 hr under Aratmosphere . The weight change measurements made on the coated steel during the cyclic tests are used to determine kinetics of hot corrosion at temperature range (800-1000oC) for 100 hr at 5 hrcycle .X-ray diffraction and optical microscope are used to characterize the oxide phases where the oxide phases that formed on coated system are SiO2 and Al2O3 .The parabolic rate constants (Kp) calculated show that the corrosion rate is minimum at 800oC compared to other temperatures. The experimental results, the fuzzy logic model, and the statistical results showed good correlations.The fuzzy logicmodels are developed using Matlab toolbox functions.

Formation of Compressive Residual Stresses by Shot Peening for Spot Welded Stainless Steel Plates

Ali H. Fahem; Samir Ali Al-Rabii; Ahmed Naif Al-Khazraji

Engineering and Technology Journal, 2013, Volume 31, Issue 11, Pages 2198-2211

In this paper, a stainless steel 316 was selected for this study and tested to obtain its chemical composition, mechanical properties and stress relieving. Then, two plates (55*55*1) mm were first joined by spot welding and later tested by X-Ray diffraction (XRD) machine to measure the tensile residual stresses formed due to thermal effect. In order to remove the tensile residual stresses, a shot peening process for these spot welded plates was made to create the compressive residual stresses which will improve the life of spot welded part during the service. The results of the x-ray diffraction tests exhibited that only compressive residual stresses formed in the shot peened spot welded plates.

An Economic Importance for Using the Flat Plate Solar Receiver in a Single Effect Cooling System Operation

Hashim Abid Hussen

Engineering and Technology Journal, 2013, Volume 31, Issue 11, Pages 149-168

Today, an electric consumption on the cooling are increased and the sources of classical energy in words and in our country are decreased, in additional, the heat emission phenomena and desert climate, making us to research about solar energy which available in our country. Single effect cooling system is chosen in this work to applied the solar energy since, the temperature required to working it is not high, and there is a possibility to use solar energy under the conditions OF Erbil city. The temperature ranges re for heating water of generation system are determined and COP variation with condensation temperature are studied by using the diagrams. Solar receiver area calculated by using (F-chart ) method .The working are simulated for summer months by using TRNSYS program's which is dependent on weather data . Average heating load for each month are calculated , also the average radiation daily and cooling load for summer months are calculated .The results indicated that, the optimum area was equal to (160 m2) which satisfied the maximum value of P*F to produce cooling power 50 kW and COP = 80% . The simulation was by TRNSYS program which predicted the performance of flat plate solar recovers through the Summer months.