Print ISSN: 1681-6900

Online ISSN: 2412-0758

Volume 32, Issue 9

Volume 32, Issue 9, September 2014, Page 304-2330


Treatment of Soft Soil by Sand Columns

Namir K.S. Al-Saoudi; Mohammad M. M. Al-Kaissi; Nawres A. A. Rajab

Engineering and Technology Journal, 2014, Volume 32, Issue 9, Pages 2106-2118

Stone or sand columns are most widely used to improve the engineering properties of soft saturated soils. In principles, sand columns technique is very close to the well-known stone columns technique and the only difference is the backfill materials.
The present work focuses on implementing sand columns in soft soil of different diameters, different relative densities considering both floating and end bearing types.
The model tests were performed inside a steel container (600mm x 600mm and 500mm in height). Sand columns of diameters ranging between 22mm to 50mm were constructed in beds of soil of undrained shear strength ranging between (15-20) kPa. Each individual sand column was loaded vertically through a rigid circular footing of diameters between 28.6mm to 64.7mm provided an area replacement ratio (as) of (0.6),the ratio of column depth to the column diameter (L/D) was (6).
The model test results revealed good improvements of the load carrying capacity of the columns ranging between (1.3 to 1.9) and significant reduction in the settlement over the untreated soil ranging between (0.18 to 0.47). End bearing columns exhibited better results than floating columns and the diameter of column has no effect on bearing capacity as the (as) and (L/D) are constants

The Mechanical and Thermal Properties of Polymer Hybrid Composite Reinforced by Rice Husk Ash at Different Conditions

Sihama Essa Salih; Basma Hashim; Haitham Mahmood Al-tamimi

Engineering and Technology Journal, 2014, Volume 32, Issue 9, Pages 2119-2133

This research was carried out to study the effect of natural and calcined temperature of rice husk ash with selected temperature (900,1100,1300oC) on the mechanical and thermal properties for the prepared hybrid composite with fixed volume fraction (25% fiber glass, 5% rice husk ash ).The mecha
nical properties include (tensile strength, bending strength, impact strength and hardness). The results show that the mechanical and thermal properties increased with increasing the calcined temperature and the best calcining temperature of rice husk ash is 1300oC, grinding rice husk before burning led to a decrease in mechanical properties and thermal conductivity.

Life-Cycle Cost Analysis for Three Different Types of A/C Systems Applied on an Apartment Located in a Multi-Floors Residential Tower in Mosul City

Badran Mohammed Salim

Engineering and Technology Journal, 2014, Volume 32, Issue 9, Pages 2134-1147

This research studies the life cycle cost analysis using detailed cooling and electrical load profiles to calculate initial and running costs to evaluate the economic feasibilities of three different types of air conditioning systems as residential air conditioning system (RACs), commercial air conditioning system (CACs) and multi power air conditioning system (MPACs). The present-worth cost method for life-cycle cost period for ten (10) years analysis is applied to a sample building located in Mosul city / Iraq so as to select the best air conditioning system. The cooling load temperature differential with cooling load factor (CLTD/CLF) was used with hourly analysis program (HAP v4.6) for the estimation cooling load in each room of apartment.
The results showed that the RAC system is lower than CAC and MPAC systems in initial cost approximately 53% and 67% respectively and the running cost for CAC system is lower than RAC and MPAC systems approximately 12% and 7% respectively for one month. The the total cost for two systems RAC and CAC are equal after 20 months of the beginning run and after even break point (BEP) the total cost for CAC system began to decline which indicates there is save in electric consumption and present worth cost over a period of (10) ten years after operation interval. The CAC system uses duct always to distribute air into each condition zone, therefor this system gives less noise of air distribution with best interior aesthetic appearance so that it fits with the interior decoration for each rooms of apartment. The outdoor unit of CAC system doesn’t appearance because the system working for long distances and can put outdoor units on the roof of the building.

Experimental and Finite Element Analysis on Rounded Corners Square Shape Tube Hydroforming Process

Hani Aziz Ameen; Nahedh Mahmood Ali

Engineering and Technology Journal, 2014, Volume 32, Issue 9, Pages 2148-2164

Tube hydroforming is a forming process where an inner pressure combined with axial feeding deforms the tube to the shape of a die cavity, i.e. the process state where the hardening of the material is unable to resist the increase in inner pressure and wall thickness reduction. In the current work the tube with circular cross section is deformed to square cross section using hydraulic pressure. The die of the square edges is designed and manufacturing to change the tube with circular cross section to square cross section. The die and tools were designed and manufactured in order to satisfy the experimental work.The hydraulic system manufactured is capable to give several values of internal pressure. Initially circular tubes are inflated against a square die while simultaneously they are axially compressed in order to delay wall thinning and burst and achieve an accept tube wall thickness distribution. The dimension of tube used in the experimental work of copper is (L=110 mm, do=9.4 mm , to=1.5mm) to obtain forming limit diagram and mechanical properties of tube and value of the bursting pressure and final thickness for copper tube (170MPa ) and 1.18 mm. A squared grid has been printed by screen method with dimensions (5x5mm) the strain measurement accomplished by measuring the dimensions of the grid printed before and after deformation. The finite element method was applied via ANSYS11software package in order to determine the tube thickness, stress and strain behavior and the internal pressure required to form the square shape tube and the radius of curvature of the tube.It was found that the generated strain during the tube hydroforming process in the square cross – sectional die was less than that in ANSYS software within 20%. The results showed good agreement.

Gain Characteristics for C-Band Erbium Doped Fiber Amplifier Utilizing Single and Double-Pass Configurations: A Comparative Study

Abdulla. K. Abass; Mohammed J. Abdul-Razak; Mohammed A. Salih

Engineering and Technology Journal, 2014, Volume 32, Issue 9, Pages 2165-2173

An erbium doped fiber amplifier in the conventional communication window utilizing single and double pump pass configurations were demonstrated and compared using OptiSystem 12 software.
Both of gain level and gain profile were improved in double-pass configuration utilizing broadband optical mirror. The maximum gain in both single and double-pass configurations are about 36.83dB and 50.1dB respectively, which represents a 37.13% improvement in gain level with double-pass configuration.
In addition, a 25mW pump power in double-pass configuration can provide the same gain level in a single-pass configuration at a pump power of 100mW and an input signal power of -20dBm at 1530nm. This represents a pump power conservation of about 25%.
The results show that the double-pass amplifier produces a higher noise figure than the single-pass configuration, but still in suitable level less than 6dB.

Evaluation the Hydraulic Aspects of Stepped Labyrinth Spillway

Jaafar Sadeq Maatooq; Taha Yaseen Ojaimi

Engineering and Technology Journal, 2014, Volume 32, Issue 9, Pages 2174-2185

This study was adopted a new concept to enhance performance of stepped spillway towards more dissipation of kinetic energy along chute face through increases interlocking surface areas between the mainstream and trapping cavity recirculation vortices on the tread of chute steps and each step edge that beneath it, and increasing the interaction of the flow interference over stepped spillway. The aim of this concept is by employment the specification of a labyrinth weir by configured as a stepped spillway, to produce new steps named as Labyrinth stepped spillway. Experiments were restricted in skimming flow regimes, it have been carried out on four physical models with chute angles (35°). Where models are classified into three labyrinth stepped spillway models of three different magnification length ratios LT/W=1.1, 1.2, and 1.3, additionally; a traditional or conventional shape models were used for comparison. All physical models assembled with step height 4 cm, eight steps constructed for a total height of 32 cm and width of 30 cm .The results generally show that the energy dissipation with labyrinth shape stepped spillway was more than resulted with the traditional shape. As the magnification ratio increase, the energy dissipation observed to increase compare with traditional model.

Investigation into Deformation Monitoring of Mosul Dam

Rasheed Saleem Abed

Engineering and Technology Journal, 2014, Volume 32, Issue 9, Pages 2186-2195

It is crucial to monitor the deformation of dams for saving lives and properties, economy and the environment. Many critical observables have to be studied on the dam and the near vicinity. Mosul dam have been monitored according to many engineering standpoints since its construction more than two decades ago. In the last few years there was a debate on the safety of the dam. In this paper, the author made his own analysis on a subset of archived surveying measurements and field observations. Problems in data processing and probable causes of large errors in results are discussed. It shows that errors in measurement and analysis can cause fears and misleading concepts about safety of the dam. Full conclusions of the safety of the dam can only be obtained from a wide range of critical engineering limitations among which is the deformation monitoring.

Kinematics Analysis of 5250 Lab-Volt 5-DOF Robot Arm

Wathik Isaa Mahdi AL-Tameemi; Wael Mohammed Hasan Hadi

Engineering and Technology Journal, 2014, Volume 32, Issue 9, Pages 2196-2204

This paper presents for the first time a complete kinematic analysis of 5250 Lab-Volt 5-Dof robot which include both forward kinematics and inverse kinematics for this robot arm. The kinematics problem is defined as the transformation from the Cartesian space to the joint space and vice versa. The forward and inverse kinematics for any type of robots are very important in both trajectory planning and position control for the robot arm,the Denavit-Harbenterg (D-H) representation is used to model robot links and joints in this paper. The inverse kinematics have been solved using analytical solution and programmed using MATLAB to move the robot.

Effect of Quenching Media on the Mechanical Properties and Abrasive Wear Resistance of (34Cr4) Steel Blade with Soil Texture Used in Agricultural Equipments

Abbas S. Alwan

Engineering and Technology Journal, 2014, Volume 32, Issue 9, Pages 2205-2215

In this paper, a study the effect of quenching media on the mechanical properties and abrasive wear has been done on steel blade (34Cr4) for agriculture equipment with soil texture. It has found that heat treatment technique is promising to improve the quality of agriculture equipments and components working in soil under dry conditions. Abrasive wear resistance is very important in many applications and it is directly correlated with hardness of metal surface. The heat treatments have large role to alter the mechanical properties and wear resistance of steel type (34Cr4). It was found that the wear resistance increases with increase hardness which increases with varying quenching media as follows; 38HRC, 56.6 HRC, 58.3 HRC and 60.6 HRC for as – received sample, caustic Soda (10%), engine oil and flaxseed oil respectively. It was found also that the wear resistance increases with decreasing toughness to values 48.3 J, 45 J, 40.2 J and 27J respectively. Wear was presented on the worn surfaces of the steels which were used in this work. All mechanical properties depended on microstructure which consists of martensitic structure and some amount of carbide particles.

The Influence of Injection Timing on Combustion and Emission Characteristics of HSDI Diesel Engine

Hayder A. Dhahad; Mohammed A. Abdulhadi; Ekhlas M. Alfayydh; T. Megaritis

Engineering and Technology Journal, 2014, Volume 32, Issue 9, Pages 2216-2234

An attempt has been made to study the combustion and emission characteristics of ultra-low diesel fuel for high speed direct injection ( HSDI) diesel engine at different fuel injection timings( -12,-9,-6,-3,0 )ATDC . The fuel injection pressure was 800 bar and at high load ( 80Nm= 5BMAP) , low load ( 40Nm=2.5BMAP ) , With constant engine speed ( 1500rpm) . In-cylinder pressure was measured and then analyzes this pressure using LABVIWE program and calculation program in MATLAB software to extract the apparent heat release rate, the ignition delay, combustion duration and the amount of heat released during the premixed and diffusion combustion phases . The influence of injection timing on the exhaust emissions such as carbon monoxide (CO), total hydrocarbons (THCs), nitric oxides (NOx), smoke number (SN) and fuel consumption were also investigated.
A result referring to that the retardation of the injection timing lead to increase the ignition delay and therefore the premixed burn fraction which plays a key role in the combustion and emission characteristics .this leads to change combustion mode to low temperature combustion at late injection timing.

Numerically and Experimentally Studying of some Mechanical Properties of the Polyester Matrix Composite Material Reinforced by Jute Fibers

Jawad Kadhim Oleiwi; Mohamad K. Alwan; Qahtan Adnan Hamad

Engineering and Technology Journal, 2014, Volume 32, Issue 9, Pages 2235-2247

This research focuses on the preparation of polymer matrix composite material by (hand lay – up) method, where the material (rectangular beam) was prepared from unsaturated polyester resin as a matrix reinforced by natural jute fiber with different volume fraction (3%, 4%, 5%, 6%).
Numerical studies by using finite element method (Ansys 11 package) to study the effect of selected volume fractions of jute fibers on the bending properties.
Results of this experimental research indicate that increasing the volume fraction of jute fibers lead to increase bending modulus of elasticity.
The values of flexural strength and shear stress increase with the increase of jute fibers volume fraction while the values of deflection and maximum strain decreases for both experimental and numerical studies.

Analysis of the Capacity, Spectral Efficiency and Probability of Outage of Adaptive Mobile Channel for WiMAX System

Hadi T. Ziboon; Wasan S. Rasheed

Engineering and Technology Journal, 2014, Volume 32, Issue 9, Pages 2248-2267

This paper presents an analysis of the channel capacity, spectral efficiency and probability of outage for the 4th generation adaptive modulation ofWiMAX system. The adaptive modulation techniquesare Variable rate-Variable power, Variable rate-Constant power and Constant rate by using truncated channel inversion in the presence of Additive White Gaussian Noise (AWGN), Rayleigh fading and Nakagami fading.
The growing demand for wireless communication requires determining the capacity, spectral efficiency and probability of outage of these channels to evaluate the performance time varying channels.
The analysis results show the advantage of using WiMAX system with adaptive MQAM modulation techniques. Analytical results have proved that the channel capacity is improved by (38) M bit/sec when increasing the bandwidth fromMHz to 20MHz in the presence of AWGN, the capacity channel is improved by (35) Mbit/Secwhen increasing the bandwidth from 1MHz to 20MHz in the presence of Rayleigh fading with Variable rate-Variable power, the capacity channel is improved in the presence of Nakagami fading (m=2)which is (37) Mb/sec and improved (38) when (m=3) due to severe effect of Nakagami when increasing the 1MHz to 20MHz for a given SNR. However, the analysis of spectral efficiency shows that maximum spectral efficiency is accrues in Shannon capacity.The spectral efficiency decreases when Bit Error Rate (BER) increases. The analysis results show the spectral efficiency decreases (0.5) when BER=〖10〗^(-3)is used than when BER=〖10〗^(-6) is used. The probability of outage increases when the BER increase.

Characterizations of Semi-Silica Refractory Bricks Produced from Local Iraqi Materials

Mohammed H. Al-Taie; Alaa H. Ali; Abeer F. Al-Attar

Engineering and Technology Journal, 2014, Volume 32, Issue 9, Pages 2268-2276

This research was carried out to investigate the suitability of locally white sand and Dwaikhla clay (Kaolin) for manufacture of semi-silica refractory bricks as thermal insulators for lining the furnaces. Preliminary investigations had been done to determine the physical, chemical, thermal and mechanical properties with mineralogical constitution of raw materials by XRD analysis. Different amounts of kaolinite were added as binder to the white sand (raw materials) of semi-silica bricks. The specimens molded according to DIN standards by using semi-dry pressing method at pressure of (24.516MPa) according to the DIN1068 standards. After drying process at 110°C the specimens fired at firing temperatures (1000, 1100, 1200, 1300 and 1400) °C. The fired specimens have been investigated to determination the physical properties including bulk density, porosity, and the mechanical properties including compressive strength and thermal properties including thermal conductivity. It has been observed from the results that local white sand and kaolinite could be used as possible source raw materials for manufacture semi-silica refractories, mainly required for glass, ceramics factory in Rammadi.

Estimating Reference Evapo- transpiration in Mosul (Iraq) Using Cascade Neural Networks

Fatin Mahmoud Shehab; Raid Rafi Omar; Radhwan Yousif Sedik

Engineering and Technology Journal, 2014, Volume 32, Issue 9, Pages 2277-2285

Recently artificial neural network (ANN) has been applied for estimating reference evapo-transpiration (ETₒ).In this study a mathematical model was built by application the cascade forward network technique (CCANN) to estimate the daily reference evapo-transpiration in the city of Mosul, north of Iraq .The input parameters for the CCANN were the: temperature, solar radiation, wind speed at 2m height, and relative humidity. A check for the accuracy of the performance of the network was made using values of reference evapo-transpiration obtained from pan evaporation method. The results revealed linear correlation between the network output and the data of the measured pan evapo-transpiration with correlation coefficient of (0.9679). This indicates the possibility of use of CCANN to determine the daily reference evapo- transpiration. The results also show that the CCANN model performs better more accurate compared to other models.

Fabrication, Characterization and Modeling of Al2o3/Ni Functionally Graded Materials

Alaa Abdulhasan Atiyah

Engineering and Technology Journal, 2014, Volume 32, Issue 9, Pages 2286-2302

Functionally graded materials (FGMs), with ceramic and metallic constituents, are frequently used for tremendous high temperature applications. In this paper, six sets of FGMs samples were designed and fabricated using powder technology technique. All FGMs were sorted according to the conditions of sintering (i.e. temperature and time). The ceramic constituents were represented by (Al2O3) and the metallic constituents were represented by (Ni).It is found that as the sintering temperature and time increased, the apparent density was increased and porosity was reduced. (F-FGM, sintered at 1350°C for 3 hrs.) sample seems to impart high and slight linear graded microhardness across the layers without any obvious jumps throughout the thickness. The interfacial microhardness values were found very close to the bulk microhardness of adjacent layers. The reason behind such behavior is the minimum porosities and improved apparent density due to the efficient sintering practices (i.e. 1350°C and 3 hrs.) and uniform mutual diffusion of (Ni) and (Al2O3) particles across the layer interfaces. As the sintering time and temperature increase, the microstructure becomes much denser and the interfaces become more homogeneous that lead to eliminate the discontinuity in microstructure. A Finite element method throughout the COMSOL Multiphysicswas used extensively in estimation of temperature distribution through the thickness as well as residual stresses that induced as a result of high temperature loading of fabricated FGM. The model also shows aclear fluctuation of stresses along the thickness that imparts a development of stress concentration regions near the interfaces of layers, especially at the lower half region of FGM that was enriched by (Ni). Stresses clearly become normal variables with thickness at the upper half of FGM that enriched with (Al2O3).

Fabrication and Characterization of ZnO Gas Sensor

Alaa A. Abdul-Hamead; Farhad M. Osman; Alaa S. Taeeh

Engineering and Technology Journal, 2014, Volume 32, Issue 9, Pages 2303-2312

In this paper thin films of zinc oxide ZnO was prepared by spray pyrolyess method with thickness were about ( 0.1 ±0.05 µm) on n-type silicon substrates at different deposition temperature (300,400,500) C°, from zinc chloride at concentrations (0.05,0.1) M as a sensor for pollutant gases like CO2 , NO2, and H2S related with oil manufacture .
The crystallinity and morphology of the films were characterized by XRD, and optical microscopy was done on prepared films , addition to sensitivity to polluting gases previously mentioned at different test temperature (10-50) C°.
Result shows that the crystallization increased by increasing deposition temperature(substrate temperature), and the sensitivity increased by rising both of the gas concentration or temperature.

Influence of Power Density and Exposure Time on Laser Drilling Hole

Saad Kariem Shather; Mohammed Sattar Jabbar

Engineering and Technology Journal, 2014, Volume 32, Issue 9, Pages 2313-2321

laser drilling play an important role in special applications with high accuracy dimensions, this paper was focused on two types of ceramics; aluminum oxide (Al2O3) and zinc oxide (ZnO) of 4 mm thick have been drilled by using continuous wave (CW) CO2 laser. the exposure times applied were (20, 40, 50) sec and the other laser parameters were kept constant and to avoid large distortion, A comparison between the two kinds of ceramic are carried out to determine the effect of laser parameters on them. It founds that ZnO holes are cleaner than Al2O3 holes. Experiments proved that Exposure time at 50 sec resulting in similar penetration depth of 1.5 mm for both materials. Also for exposure time 41 sec gives the same taper angle.

Design of Circular Printed Slot Antenna for Multiband Wireless Communication Applications

Mehde M. Al-Shimmary

Engineering and Technology Journal, 2014, Volume 32, Issue 9, Pages 2322-2330

In this paper, a printed antenna with circular slot is presented as a candidate for use in multiband wireless communication applications. The slot structure of the proposed antenna is with a circular slot structure. A smaller annular conducting ring with thickness w has been embedded in the slot structure. The slot structure together with the conducting ring has been etched on the ground plane of a substrate with relative dielectric constant of 4.4 and 1.6 mm thickness. A 50 Ω microstrip feed line has been printed on the reverse side of the substrate. Modeling and performance evaluation of the proposed antenna have been carried out using the commercially available EM simulator, HFSS from Ans of Corp. Simulation results show that the proposed antenna has a return loss response with four resonant bands. A parametric study shows that the antenna can cover most of the communication services below 6.0 GHz by varying the width of the inner conducting ring. The results also reveal that for the multi-band configurations studied, the ratios of the resonant frequencies (f2/f1) and (f3/f2) are with a considerable range. This shows flexibility in designing dual frequency antennas with the desired resonant frequencies. Furthermore, results show that the antenna has reasonable radiation characteristics and gain throughout the four resonating bands.

The Effect of the Addition of Natural Rubber to (U-PTE) Resin on some Mechanical Properties

Wafaa Mahdi Salih

Engineering and Technology Journal, 2014, Volume 32, Issue 9, Pages 304-310

In this research polymer was prepared from Alkyd resin (U-PTE) with ratio 100% the and natural rubber with ratio 30%. The mixing process was performed by hand lay-up method. Some mechanical properties were studied in this work which included (flexural bending, shear stress, Impact test (charpy method) . the results showed that the addition of natural rubber to (u-pte) resin with this ratio leads to become the brittle behavior and decrease in the shear stress increase the ability of material to impact because the blend materials become elastic .the flexural strength increase of blend two times comparing with its value of pure resin while the result of shear stress value of blend showed decreasing with ratio(43%) but the impact value of blend increased with ratio (20%) with it value before the blending.

Using of Statistical Methods to Determine The Defects Cost Affected on The Product Data and Forecast Losses for Decision-Making

Ahmad A.Alkafaji; Salman H.Omran; Ismeal H.Ehallob

Engineering and Technology Journal, 2014, Volume 32, Issue 9, Pages 311-323

The research deals with methodology proposed for a final product data fully inspected for decision-making on improvement or continuing production by using some methods of forecasting . The proposed methodology was applied in the General Company for Electrical Industries-Motors factory for air cooled engine output (1/4 Hp) for different years and proposed two ways to arrange data due to its large size and irregular production quantities: the first method by dividing the data to chapters for the rejected production, size and the most frequent defects ,the cost and losses using the Histogram, the second method is by divided production data in batches of size (1,000) units produced and used two methods(Linear Trend Model and Single Exponential Smoothing ) to forecast and calculated the cost.
The search results showed that the single exponential smoothing is the best forecasting through the measurement of sum of relative squares error MAPE and the measurement of absolute deviation MAD and the mean average deviations MSD.