Print ISSN: 1681-6900

Online ISSN: 2412-0758

Volume 31, Issue 4

Volume 31, Issue 4, March 2013, Page 71-792


Digital Geotechnical Maps of Basrah City Using Geographical Information Systems Technique

Mohanad M. Kadhim; Namir K. S. Al-Saoudi; Abdul Razzak T. Ziboon

Engineering and Technology Journal, 2013, Volume 31, Issue 4, Pages 599-617

The work in this research presents the use of Geographical Information Systems (GIS) and Global Positioning Systems (GPS) which integrated with remote sensing (RS) techniques in geotechnical engineering for Basrah city south of Iraq. These maps provide a powerful database and strong visual presentation of geotechnical data.
The research is performed in several stages that started with the utilize of LNADSAT 7 ETM+ satellite image with 14.25 m resolution within the visible bands of the study area, applying the geometric correction and performing image enhancements by using ERDAS software. Then collection of laboratory tests reports of boreholes is conducted in the study area and projecting their location as a layer using ArcGIS software after determining their position using a GPS instrument. The total number of soil investigated reports is (31) with total number of boreholes is (105).
The results of this study emphasize the possibility of producing digital geotechnical maps by using ArcGIS software that represents the distribution of the geotechnical properties for study area, such as allowable bearing capacity, the normalized undrained shear strength (cu/P'o), Liquidity Index and compression index.

Numerical Modeling of Pore Water Pressure Development in Mosul Dam

Suhail A. A. Khattab; Amina A. Khalil

Engineering and Technology Journal, 2013, Volume 31, Issue 4, Pages 618-631

A finite element method is useful tools to be applicable in many geotechnical engineering topics. In this paper the pore water pressure development within the clay core of MOSUL earth dam were investigate considering the saturated/unsaturated conditions using GEO-SLOP software. Three selected sections through the dam were chosen for the analysis ( in the middle, right, and left sides of the dam to cover the dam body). The investigation of the dam body response to the earthquakes with many values of the maximum horizontal acceleration was done. Normal, maximum, and minimum operation water levels with possibility of rapid drawdown of water level during (8,21,30) days were also consider. Transient and steady state analysis of pore water pressure was performed, finally the results were compared with the actual field data.
Results indicated that, the maximum pore water pressure was occurred for the nodes in the upstream near of the core base at the time during and after the end of earthquake shaking. The results of the study also presented a positive pore water pressure development in the lower part of the core when the water was at maximum, normal, and minimum operation levels, with negative values near the crest of the dam. high pore water pressure was record through sec6 and sec4, for the rapid drawdown of water level at time 8 days. Finally, nearly identical pore water pressure results are obtained from the numerical analysis and the recorded field piezometers readings data.

Neural NetworkModeling of Oxidation Kinetics in Air of Steel-T21 Alloy Coated by Simultaneous Germanium-Doped Aluminizing-Silicon zing Process

Abbas Khammas; Mohanned M. H.AL-Khafaji

Engineering and Technology Journal, 2013, Volume 31, Issue 4, Pages 632-645

In this work a pack cementation of germanium-doped aluminum and silicon coatings on low alloy steel type-T21 has been applied. This gives significant improvement in the oxidation. Steel-T21 was coated with germanium-doped aluminizing-siliconizing. Diffusion coating was carried out at 1050oC for 6 h under an Ar atmosphere by simultaneous germanium-doped aluminizing-siliconzing process. Cyclic oxidation tests were conducted on the coated steel-T21 alloy in the temperature range oxide 300-900oC in air for 102 h at 3 h cycle. The results showed that the oxidation kinetics for coated system in air can be represented by parabolic curve .Oxide phases that formed on coated system are SiO2 and Cr2O3. A neural network model of oxidation kinetics has been proposed to model the oxidation kinetic. The neural model shows good agreement with the experimental data.

A Heat Pipe Performance With Heptane as aWorking Fluid

Hussain H.Ahmad; Raqeeb H. Rajab

Engineering and Technology Journal, 2013, Volume 31, Issue 4, Pages 646-660

The heat pipe is a device that efficiently transfers heat from one end to another. It has been widely applied in electronic system cooling and heat spreading applications due to its superior heat conductivity. Many parameters affect the performance of the heat pipe which are worthwise to be investigated. For this reason an experimental rig was designed and constructed to study the important parameters such as the heat load, the working fluid charge and the angle of inclination. Calibrated thermocouples were inserted into the heat pipe outside surface, along and around it, to measure and to show the temperature distribution profile. Heptane was used as a working fluid. Results show that the maximum conductivity obtained was more than one thousand times that of stainless steel solid bar which is the material of the heat pipe container. Also, results of the experimental work show a good agreement with that obtained from theoretical and empirical correlations derived by other researchers especially when the power input is lower than (1000)W where after a dry out condition can be clearly seen.

Improving the Compatibility between Polymer-, Pozzolanic Cement-Based Repairing Materials and Concrete Substrate

Qais J. Frayyeh; Maan S. Hassan; Tahseen D. Saadoon

Engineering and Technology Journal, 2013, Volume 31, Issue 4, Pages 661-676

In this study, the compatibility of five different cement based repair materials and substrate concrete was investigated in three stages. First stage includes studying the individual properties of repair materials, and also two types of concrete, such as compressive strength, flexural strength, and dry shrinkage using BS 1881: part 116, ASTM C78-06, ASTM C157 -06 test procedure respectively. Second stage includes evaluating the bond strength of composite cylinder for different combinations of repair materials and substrate concrete. Third stage includes investigating the compatibility using a composite beam of repair material and substrate concrete under third point loading.
The experimental results show that one individual property has no crucial effect on the success of concrete repair system. Bond strength and dry shrinkage however has a strong indication about the compatibility.

Performance of Direct Sequence Spread Spectrum System (DSSSS) in Presence of Single and Multi Tone Jamming

Sadiq Kamel Gharkan; Ali Abdul-Elah Noori; Saleem Latteef Mohammed

Engineering and Technology Journal, 2013, Volume 31, Issue 4, Pages 677-691

There are various impairments or problems on direct sequence spread spectrum communication channel especially jamming problems, in order to focus on this problem a direct sequence spread spectrum(DSSS) communication system using Gold code was used as point -to-point with fully synchronized between transmitter and receiver under the effect of Additive White Gaussian Noise (AWGN) channel and single tone jamming(STJ) and multi tone jamming(MTJ).
The performance evaluation of the DSSS system was simulated in MATLAB-Simulik by measuring the bit error probability (Pe) of receiving data as a function of noise power spectral density ratio (Eb/No) and also for different cases of jamming to signal power ratio (J/S).
The simulation results showed the performance of DSSS system under the effect of STJ at carrier frequency is better than the system under the effect of MTJ at different frequencies. Also the results show when J/S increases the Pe also increases, the J/S effect has been overcome by increasing the processing gain.

Accuracy Assessment of Lidar Data Using Geomatic Approaches

Abbas Z. Khalfa; Imzahim Abdul Kareem Alwan; Adnan R. Mechman

Engineering and Technology Journal, 2013, Volume 31, Issue 4, Pages 692-702

The fast development in Remote Sensing technology with various sources of data especially LiDAR (Light Detection And Ranging) images promote the ability of using data , but the accuracy of produce Maps issue always need to be evaluate.
So the main aim of this research is to evaluate the accuracy of using elevation data for various techniques, such as Photogrammetry and remote sensing techniques then comparison with traditional filed surveying using DGPS total station and level instrument.
LiDAR data gives accurate elevation therefore; 3D model can be obtained from LiDAR data which can be used in many applications such as civil engineering and surveying engineering, etc.
In this research University of Technology has been chosen as case study area, and many Geomatic approaches executed such as extracted height of features from field surveys using Total Station and comparison with the heights extracted from LiDAR data. According to the results analysis it can be stated that the elevations from the LiDAR data within accuracy of (3-10) cm can be obtained

Implementation of Finite Element Method for Prediction of Soil Liquefaction Around Undergroud Structure

Mohammed Y. Fatah; Mohammed A. Al-Neami; Nora Hameed Jajjawi

Engineering and Technology Journal, 2013, Volume 31, Issue 4, Pages 703-714

Liquefaction is the rapid loss of shear strength in cohesionless soils subjected to dynamic loading, that it is a state of saturated cohesionless soil when its entire shear strength is reduced to zero due to pore water pressure caused by vibration. Liquefaction depends on the nature, magnitude and type of dynamic loading. An entire stratum may be liquefied at the same time under shock loading, or liquefaction may start at the top and proceed downward with steady-state vibrations.
In this paper, finite element method is used in an attempted to study liquefaction of soil based on the case solved previously by transient infinite element for 2D soil - structure interaction analysis considering infinite boundaries but without generation of pore water pressure. The properties of fully saturated sandy soil and concrete are fed to geotechnical finite element software called QUAKE/W program.
The results showed that liquefaction occurs faster at shallow depths due to low overburden pressure. Also, liquefaction zones and deformation occur faster with the increase of dynamic loading amplitude. The analysis marked that increasing the amplitude pressure accelerates the occurrence of initial liquefaction and increases the pore water pressure.

Catalysts Regeneration Using Laser Technique in Petroleum Industry

Adawiya J. Haider; Khalid A. Sukkar; Duha S. Ahmed

Engineering and Technology Journal, 2013, Volume 31, Issue 4, Pages 715-722

The catalyst cost regards one of the most important obstacles in petroleum industry. Therefore, the regeneration of catalysts could be more economic process to get high performance and low cost. In this work, three types of catalysts were investigated: Pt/A2lO3 (spent catalyst from reforming unit/Al-Doura Refinery), prepared Pt/A2lO3(Doura) and Pt/HY. The performances of catalysts (activity, selectivity and catalyst stablity) were studied using n-heptane as feedstock under reforming conditions.
The operating pressure kept constant at atmospheric pressure, and the operating temperature 500 oC. The liquid flow was 0.4 l/h. The amount of catalyst was 50 gm, H2/H.C ratio used was 2 for all experimental runs.
The catalyst of reforming process has been successfully regenerated using laser technique. This technique regards as a new approach for catalyst regeneration in petroleum industry to remove carbon deposits. On the other hand, this regeneration technique shows a great potential for economical processes in petroleum refineries. The results show that the best operating conditions for the regeneration process were: laser power of 13 watt and regeneration temperature of 650 oC. From the results of catalyst characterization it was concluded that the structures and morphology of all catalysts types did not effected or destroyed through using laser power.

Methodology for Calculating Life Expectancy of Existing Concrete Structures

Faisal M. H. Sabouni

Engineering and Technology Journal, 2013, Volume 31, Issue 4, Pages 723-729

A study was conducted on four reinforced concrete buildings built in the desert region in one of the Arabian Gulf states in the late seventies to mid eighties to assess the remaining life expectancy of these buildings. Testing included core sampling, CAPO semi-destructive testing, half-cell potential measurements, cover meter, dust sampling analysis, water penetration measurements, cement content, cement type and carbonation depth evaluation.
A modification of the BS-ISO 15686 -1:2000 (Ref.1) equation for the life expectancy is presented to incorporate the role of the dominant variables in the estimation of the life expectancy of the four buildings

Evaluation of Critical Stress Intensity Factor (Kic) for Plates Using New Crack Extension Technique

Ameen Ahmed Nassar

Engineering and Technology Journal, 2013, Volume 31, Issue 4, Pages 730-740

The technique of crack extension is applied to the computation of critical stress intensity factor in linear elastic fracture mechanics for cracked plates in tension for different crack configuration (i.e. central crack, edge crack, and double edge crack). The new technique uses the Brown approximate solutions for stress intensity factors and the Westergaard analytical solutions for stress and displacement near a crack tip in finite plate to calculate crack extension during each load step and then calculating the critical stress intensity factor using an incremental procedure. A matlab program was developed for the purpose of this work, which proved to be a good tool for the computation of critical stress intensity factors for cracked plates. The results were in good agreement with results of other methods available in the literature.

Using Propylene–Ethylene Grid to Improve the Production of Precast Concret Slabs

Zainab Abdulrdha Thweny

Engineering and Technology Journal, 2013, Volume 31, Issue 4, Pages 741-751

The precast concrete roofing slab produced from the local factory were below the Iraqi standard requirement (NO 1107-1988).
This study has been made to improve the production of precast concrete slabs by using(propylene – ethylene copolymer grid )which is a waste material produced from the base of polymer boxes .
The depended mix of the precast concrete slab in the local factory did not use the correct proportion ,tested mixes were redesigned and prepared to achieve the limited requirements . Propylene – ethylene copolymer grid was used to have better results, less costs, with protection of the environment from pollution ,where there is difficulty to remove it even when it is fully exposed to severe weather conditions .the manufactured slabs had dimensions of (800×800×40)mm and testing program extended to 60 days of age and comprised ,breaking loads, water absorption ,and impact resistance of concrete. The total number of manufactured samples was (55 slabs).
The test results indicated that the weigh ted mix proportions ((1:1.5:2.45) cement :sand : gravel ) with w/c=0.41 , superplasticizer(0.75 liter/100 kg of cement )and propylene –ethylene copolymer grid with a dimension (600×600)mm enhances the mechanical properties of concrete . It increased the breaking load by 81 % compared to ordinary production. while the impact resistance increased to 26 blows compared to 3 blows for the ordinary production. However, the polymer grid decreased the width and depth of cracks and maintained the integrity of the slabs after failure .

Statistical Distributions ofWind Speed for Baghdad, Basra and Mosul Governorates

Azhar Hadi Mahdi

Engineering and Technology Journal, 2013, Volume 31, Issue 4, Pages 752-773

The goal of this research is to calculate two basic parameters in Gumbel distribution which is known as prevailing model for quantifying risk associated with extreme wind speed, earthquakes and rainfall. This distribution depends on two basic parameters which are location and scale. To estimate these parameters four methods are applied; method of moments , maximum likelihood method , generalized extreme values and generalized Pareto method , for more than fifty years data of maximum wind speeds of three governorates of Iraq ( Baghdad , Basra and Mosul ) .A simple mathematical method is used in addition of using new software . Results shows similarity of these parameters (location and scale) as shown in tables and graphs for these methods indicated above and we use more tests depends on tabulated values which is improved using Gumbel distribution for extreme values .Fortran program was applied to calculate the equations and derive the parameters and goodness of fit test for the distribution that mentioned in the text.

Intersection Analysis by aaSIDRA Software for Computer Simulation to Optimize the Traffic Flow

Ali Ahmed Mohammed

Engineering and Technology Journal, 2013, Volume 31, Issue 4, Pages 774-792

Computer simulation is important for the analysis of freeways and urban streets systems. Through simulation, Transportation specialists can study the formation and dissipation of congestion on roadways. The Roundabout (Bandar Baru Bangi) and intersection The National University of Malaysia (UKM) are two major causes that have a significant effect on travel time, delay, level of service, stop and degree of saturation. The aim of this paper is to analysation and rationalization the traffic flow of the intersection and roundabout to provide useful information for engineers to design the roads with the shortest travel time and reducing the congestion in roundabout and intersection.
The data required for the study were mainly collected through video filming technique .Also the calculation and assessment are constructed with the aaSIDRA software.

Comprehensive Electrochemical Evaluation of Protective Coatings Properties by Sol-Gel Route for Stainless Steel Corrosion

Atia; Mohammed Hussein J. Al

Engineering and Technology Journal, 2013, Volume 31, Issue 4, Pages 71-86

Sol gel nano ceramic coatings have been applied on stainless steel to develop their biological characteristics and increase resistance to corrosion and wear. In this work nine electrochemical parameters were calculated, adopted to set a comprehensive evaluation map for protective properties of the coatings obtained based on occurrence degree of cracks, porosity, general and localized corrosion by using d.c. Potentiostate utilized for measuring the polarization curve in 3.5% NaCl solution at 250C for a single alumina layer deposited on stainless steel specimens by the dipping technique from four solutions containing different alumina concentration 0.25, 0.26, 0.61 and 0.93 mole/liter prepared by dissolving aluminum isopropoxide in water, the coats were then heat treated to 6000C. The results showed the possibility of obtaining clear protective properties that facilitate the comparison between the types of thin coatings deposited on the surfaces of the stainless steel by sol gel method.