Print ISSN: 1681-6900

Online ISSN: 2412-0758

Volume 31, Issue 7

Volume 31, Issue 7, June 2013, Page 110-1430

Synthesis and Studying SomeMechanical Properties of Nanocomposite

Fadhil A. Chyad; Abdul-Raheem K.Abid Ali; Auday A. Mehatlaf

Engineering and Technology Journal, 2013, Volume 31, Issue 7, Pages 1221-1228

This study aims to synthesis a nanocomposite from Al2O3 – Cr2O3 and studying some of its mechanical properties like microhardness and fracture strength.
X-Ray diffraction patterns shows a good crystallinity of the composite with very sharp and neat peaks. TEM photographs shows the good distribution of the particles which have an average particle size of (3-6 nm). The microhardness is increased with the increasing of sintering temperatures having the height value at 15% chromia while the fracture strength behaves as a bell shape having again the height value at 15% chromia.

Effect of Using Equivalent Driving Energy on Small Model Driven Pile Capacity

Kais Taha Shlash; Mohammed A. Al- Neami; Ahmed Majeed Ali

Engineering and Technology Journal, 2013, Volume 31, Issue 7, Pages 1229-1238

Physical modeling is performed in order to study particular cases of the behavior of prototype and to validate theoretical and/or empirical hypotheses.
However, most physical models will be constructed at much smaller scales than the prototype precisely because it is desired to obtain information about expected patterns of response more rapidly and with closer control over model details than would be possible with full-scale testing.
The main problem associated with physical model tests is the stress levels and soil particle size effects. These points should be considered which require deep and thorough research when studying the behavior of small scale model piles in sand. The tests indicate that the number of blows recorded when driving the model pile is affected by pile diameter more than with pile length. As well as, the heavier hammer shows precedence in bearing capacity than the light hammer because it leads to upgrade the soil properties during pile driving.

Fuzzy-Swarm Controller for Speed-Governor of Synchronous Generator

Abdulrahim Thiab Humod; Wisam Najm Al-Din Abed

Engineering and Technology Journal, 2013, Volume 31, Issue 7, Pages 1239-1262

The main objective of this work is to propose an intelligent controller to enhance the performance of hydraulic turbine speed-governor of a Synchronous Generator (SG) during different loading conditions.
The proposed mathematical model of the SG is connected to different loads in two ways. First, each load is connected individually and second, the SG loads change during the operation to ensure the robustness of controller for wide load variations.
Two types of controllers are used. The first controller is the Proportional-Integral (PI) based on Particle Swarm Optimization (PSO) technique to obtain optimal gains. The second controller is Fuzzy PD+I with gains and Membership Functions (MFs) tuned by PSO technique.
The results show the improvement of PI-PSO performance on conventional PI controller; also show the improvement in the performance of Fuzzy PD+I using PSO technique on PI-PSO.

A Bezier Curve Based Free Collision Path Planning of an Articulated Robot

Tahseen Fadhil Abbas

Engineering and Technology Journal, 2013, Volume 31, Issue 7, Pages 1263-1275

The main objective of this paper is to find a path for the robot arm from its given start point to its desired goal point in an automated manner without collision with the obstacles. This paper investigates the problem of path planning for a 5 axis robot, operating in environment with obstacles whose boundaries are enveloped by cubic shape. The path planning approach presented is developed in the robot joint space and consists of three steps. The first step is to used Bezier curve technique , the second step is to generate a sufficient number of intermediate points in Cartesian space along Bezier curve and the third step is to convert the coordinate of the generated intermediate points from it's Cartesian space into joint space and move the robot arm along the free collision generated path.
This work is not limited to theoretical studies or simulations, experiments have been run with various tests, on a LabVolt R5150 robot to assess the real efficiency and usability of the adopted method. The method applies to robots in a fixed and known environment. A number of experiments were carried out to test the ability of the robot arm to reach it's goal without collision. Experiment results verify the effectiveness of the method developed in this paper.

Optimization of Al-Doura Catalytic Naphtha Reforming Process Using Genetic Algorithm

Zaidoon M. Shakoor

Engineering and Technology Journal, 2013, Volume 31, Issue 7, Pages 1276-1296

Optimization of Al-Doura catalytic naphtha reforming process was done using genetic algorithm. The objective of optimization is maximization yield of the aromatics in order to increase the octane number of reformate.
One-dimensional steady-state mathematical model was made to study the effect of feedstock composition, feed temperature, total pressure and hydrogen to hydrocarbon feed ratio on the reformate compositions. Detailed kinetic model was developed to describe the reaction kinetic, the model involving 29 components, 1 to 11 carbon atoms for n-paraffins, 5 to 10 carbon atoms for iso-paraffins and 6 to 11 carbon atom for naphthenes and aromatics with 83 reactions. Using Genetic Algorithm, 186 parameters of the proposed kinetic model were predicted depending on plant results collected over two months from Al-Doura reforming process which located in the south of Baghdad. The validity of the kinetic model was approved by comparing the results of developed kinetic model with the actual process results.
Genetic algorithm was used again to optimize the commercial reforming process depending on reformate compositions. Optimization was carried out in temperature range between 450 to 520°C; total pressure range 5 to 35 bar; hydrogen to hydrocarbon ratio 3 to 8 and by varying the percentage of catalyst for each one of four reactors. Optimization results shows that, it’s possible to increase the aromatics composition in reformate from 63.42 % in actual unit to 70.89 % by changing the design variables and operating conditions.

Numerical Analysis of Piled Raft Foundation on Clayey Soil

Hussein H. Karim; Mahmoud R. AL-Qaissy; Mudhafar K. Hameedi

Engineering and Technology Journal, 2013, Volume 31, Issue 7, Pages 1297-1312

The piled raft foundations allow an increase in the load capacity and reduction of settlements in a very economic way as compared with the traditional foundation concepts. Due to the development of structures that use piled rafts as a foundation system, an extensive numerical modeling study was performed considering different factors and conditions. This study highlights the percentage ratio of bearing loads between the pile and the pile cap (raft). Present modeling results obtained by computer program (Plaxis 3D Foundation V 1.1) have been verified with an experimental work of the same problem using the same configuration but extended to include 8 and 16 piles with raft for different soil layers. In addition, a comparison of the present results is achieved with another a theoretical study using the program (Ansys). The finite element method through Plaxis program evaluates the effect of parameter on the load-settlement behavior of the piled raft foundation. The effect of spacing between piles on the load-settlement behavior of the piled raft foundation was also studied. The percentage of the load carried by piles to the total applied load of the numerical model for case sixteen piles with raft is around 42%. The contribution to carry the load of piles relative to the total load is decrease with the increase of the spacing to diameter ratio. The percentage of the load carrying for piled raft for the case of two piles with raft only decreases about 23% when the spacing between piles increases from 3 to 10 times pile diameters.

Effect of Plastic Fibers on Properties of Foamed Concrete

Hisham K. Ahmed; Waleed A. Abbas; DohaM. Abdul-Razzaq

Engineering and Technology Journal, 2013, Volume 31, Issue 7, Pages 1313-1330

The main objective of this work is to study the effect of adding plastic fibers on Lightweight Aggregate Foamed Concrete (LWAFC) using mix proportion of 1:2.6:0.4 by volume (cement: fine Porcelanite: coarse Porcelanite) with 2% foaming agent by weight of water, and using sand as a partial and total replacement of local Porcelanite aggregate in that mix.
The properties of lightweight aggregate foamed concrete reinforced with different percentages of plastic fiber (0.5, 0.75, and 1% by volume) were studied. Compressive strength, splitting tensile strength, flexural strength, dry density, initial surface absorption, water absorption, ultrasonic pulse velocity, acoustic impedance, and impact resistance tests were conducted on mixes at ages of 7, 28, and 60 days.
The results showed a significant increasing in impact resistance, splitting tensile strength, and water absorption 34.55%, 4.2%, 326%, and 27.3% respectively. While the results indicated that the compressive strength, ultrasonic pulse velocity, dry density and acoustic impedance of the composites were reduced when the crimped plastic fiber volume fraction increases. The percentage of reduction of these properties was 15%, 11.1%, 6.23%, and 12.55% respectively.

Characteristics of Air Impingement From an Orifice on a Target Plate

Adnan A. Abdul Rasool

Engineering and Technology Journal, 2013, Volume 31, Issue 7, Pages 1331-1350

The present work is an experimental and numerical CFD study of air impingement from orifices of different sizes in the range of (10-40) mm with a step increase of 10 mm. The impinging jet strikes the target plate at the stagnation point, converted to a wall jet beyond the stagnation zone in the outward radial direction on the target plate. Measurements of pressure coefficient (Cp) at points in plate centre and other points in the radial direction from stagnation point on the target plate show that pressure coefficients reduces gradually in the outward direction reflecting the same behavior of velocity distribution of the impinging jet ..The calculated average values of the pressure coefficients Cpavg on the total target plate area are reduced as the target plate – orifice distance is increased and its values are in the range of 0.3-0.7 with the higher jet velocity having the greater value of Cpavg for the tested axial distances in the range of 50-120 mm. Average pressure coefficient for different axial distances are calculated and are in the range of 0.4-0.6 with the higher values are noticed to be for the smaller tested orifice sizes reflecting a concentration of pressures for the small sizes of the orifice. This concentration of pressure of small orifices is attributed to the flow condition of the small orifice relative to the big orifice size where the presence of cross flow within the stagnation region of big orifice sizes tends to reduce static pressures and reduce peak heat transfer coefficients, this cross flow is confirmed by the velocity analysis using CFD numerical analysis zone at the stagnation zone. The percentages of the wall jet relative to the impinging jet velocities are discussed, where smaller orifice sizes are shown to have greater velocity percentages especially at the higher tested jet velocities.

ECG Signal Diagnoses Using Intelligent Systems Based on FPGA

Ali M. Abdul Kareem; Hanan A.R. Akkar

Engineering and Technology Journal, 2013, Volume 31, Issue 7, Pages 1351-1364

This paper presents the use of Particle Swarm Optimization (PSO), neural networks with the most promising supervised learning algorithms for automatic detection of cardiac arrhythmias based on analysis of the Electrocardiogram (ECG). Artificial Neural Network (ANN) has three layers with ten nodes in the input layer, five nodes in the hidden layer and five nodes in the output layer, which is trained using the PSO algorithm. The trained network was able to classify the ECG signal in normal signal, atrial flutter, ventricular tachycardia, sever conducting tissue and wandering a trial pacemaker. Field Programmable Gate Arrays (FPGAs) have been used to implement ANN trained by the supervised learning algorithms and PSO, because of their speed benefits, as well as the re-programmability of the FPGAs which can support the reconfiguration necessary to program a neural network. A VHDL Design of ANN platform is proposed to evolve the architecture ANN circuits using FPGA-Spartan 6 Evaluation board. The VHDL design platform creates ANN design files using WebPACKTM ISE 13.3 program. All the algorithms used to train the ANN showed high effectiveness with 100% classification.

Mechanical Properties of High Performance Fiber Reinforced Concrete

Wasan Ismail Khalil; Ikbal Naeem Gorgis; Zeinab Raad Mahdi

Engineering and Technology Journal, 2013, Volume 31, Issue 7, Pages 1365-1387

An experimental work was carried out to produce high performance concrete (HPC) using superplasticizer and silica fume reinforced with fiber. The variables studied were fibers type (steel fibers and polypropylene fibers), aspect ratio of steel fibers (60 and 100) and fiber volume fraction (0.0%, 0.5%, and 0.75%). The effect of fibers on the mechanical properties (compressive strength, splitting tensile and flexural strength, static modulus of elasticity, toughness, and resilience) of normal strength and high performance concrete was also studied. The results show that the optimum dosage of silica fume is 5% as addition by weight of cement with superplasticizer dosage 2 liter/100kg of cement. This dosage of silica fume improves the compressive strength of concrete by about 25% relative to concrete mix without silica fume. The addition of steel fibers causes a slight increase in compressive strength of HPC as fiber volume fraction increases, while the compressive strength decreases as fiber aspect ratio increases. Both splitting tensile and flexural strengths show a significant increase as the fiber volume fraction and aspect ratio increases. The percentage increase in compressive, splitting tensile and flexural strengths for HPC with steel fiber volume fraction 0.75% and aspect ratio 100 at age 60 days is about 9%, 75%, 64%, while for HPC containing polypropylene fiber with volume fraction 0.5% is about 8.5%, 2%, 0% respectively relative to non fibrous HPC.

Studying the Effect of Aluminum Powder Addition on Dielectric Behavior of Polyester Composite Materials

Nirvana A. Abd Alameer; Shayma. H. Mohammad

Engineering and Technology Journal, 2013, Volume 31, Issue 7, Pages 1388-1394

The effect of both weight fraction of aluminium and frequency on dielectric properties of Al- powder reinforced polyester composite materials were investigated. We study the dielectric behaviour of composite materials reinforced with (0, 5, 15, 30 &45) weight fraction of Al and frequency ranges (50-106) Hz at room temperature. The results show the dielectric constant and dielectric losses factor were increased with increasing in weight fraction of aluminium due to high conductivity of aluminium. The decrease in the dielectric constant and dielectric losses with higher frequencies can be explained by the fact that as the frequency increases, the interfacial dipoles have less time to orient themselves in the direction of the alternating field.

Inhibition of Aluminum Corrosion in Hydrochloric Acid Using Hexadecyltrimethyl Ammonium Bromide (Ctabr)

Anwer Abbas Hantoosh; Jamal M. Ali

Engineering and Technology Journal, 2013, Volume 31, Issue 7, Pages 1395-1403

The corrosion inhibition of aluminum in (1M ) hydrochloric acid solution in the presence of Hexadecyltrimethyl ammonium bromide (CTABr) at temperature range of 30o – 50 Cowas studied using galvanostatic polarization techniques. The results showed that the inhibition occurs through adsorption of the inhibitor molecules on the metal surface. The inhibition efficiency (%IE)was found to increase with increasing inhibitor concentration (2*10-6 M – 12*10-6 M) and decreased with increasing temperature. The behavior of these compounds on the metal surface was found to obey Temkin adsorption isotherm. Thermodynamic parameters for adsorption and activation processes were determined. Galvanostatic polarization data indicated that these compounds act as mixed- type inhibitors. Phenomenon of physical adsorption is deduced from the obtained values of Ea*andΔGads.

Face Image Recognition Using 2D PCA Algorithm

Maysaa Hameed Al-Hamdani

Engineering and Technology Journal, 2013, Volume 31, Issue 7, Pages 1404-1417

The global features of face image have been extensively used for face recognition however they are sensitive to variations caused by expressions, illumination, pose, occlusions and makeup.
The paper describes the enhancement in the behavior of the 2D PCA (Principles Component Analysis) based recognition algorithm that recognize face images by adding noise removal filter before and after the recognition stage, PCA algorithm based on information theory concept, seeks a computational model that best describes a face by extracting the most relevant information contained, and compare the eigenface with the eigenfaces in the gallery database, the euclidean distance check the face image acceptance with noise removal filter added as an additional step to modify the performance of classic PCA algorithm to get better recognition.

Arabic Word Recognition Based on 3D Radon and Multiwavelet Neural Network

Tarik Zeyad Ismaeel

Engineering and Technology Journal, 2013, Volume 31, Issue 7, Pages 1418-1430

In this paper, an automatic speaker–independent Arabic word speech recognition system is presented using 3D Radon and Multiwavelet neural network. The approach contains combining multiwavelet theory to neural network which lead to fabricate a Multiwavenet. Position and dilation of the Multiwavenets are fixed and the weights are optimized according to learning algorithm in the network. The feature extraction for real Arabic word signals through 3D radon model is used. The proposed terminology here is training process for some words of all speakers done in Multiwavenet learning phase then test for the other sample speech signals for speakers have been used in Multiwavenet classification phase. Success theory of Multiwavenets has been generalized by extension to biorthogonal wavelets which lead to identification system development. Results show the effectiveness of the proposed system presented in this paper. The accuracy in the detection process was 86% when using utterances outside the training database and around 94% when using the whole utterances database in system test process. The proposed algorithms were implemented using MATLAB2011a.

Effect of Channel Slope on Discharge Coefficient of Cylindrical Crested Weirs

Mohammed Tareq Khaleel

Engineering and Technology Journal, 2013, Volume 31, Issue 7, Pages 110-120

This research paper investigates the effect of the longitudinal channel slope on the discharge coefficient of cylindrical weirs. The methodology applied is by adopting three different diameters of the cylindrical weir and at three different slopes of the channel. In addition, various five flow rates values were used for each case.
The study showed that the discharge coefficient increases when the dimensionless value of (Hw/R) [which represents the ratio of the net hydraulic head in upstream to the radius of cylindrical weir] is high. Furthermore, the discharge coefficient increases as the channel slope increase, for the same (Hw/R) ratio. As a result, the discharge coefficient increases with the increment of cylindrical weir diameter. Finally, an empirical non-dimensional relationship was obtained between the discharge coefficient with a channel slope and dimensionless value (Hw/R) with a good correlation coefficient.