Print ISSN: 1681-6900

Online ISSN: 2412-0758

Issue 15,

Issue 15

Behavior of Khassa Chai Earth Dam under Earthquake Excitation

Mohammed Y. Fattah; Haider H. Alwash; Sarah. A. Hadi

Engineering and Technology Journal, 2016, Volume 34, Issue 15, Pages 2784-2795
DOI: 10.30684/etj.34.15A.1

An earth dam is built of suitable available soils obtained from borrow areas or required excavation which are then distributed and compacted in layers using mechanical means. Earth dams can be constructed of one material to be homogeneous or multiple materials to be zoned dams. Zoned dams are usually advised since zoning allows the use of several different types of material in the embankment which may be available from areas of borrow or required excavations.
This paper presents a dynamic analysis on a zoned earth dam subjected to earthquake motion in which pore water pressure, effective stresses and displacements are calculated. The finite element method is used and the computer program Geo-Studio is adopted in the analysis through its sub-programs SEEP/W and QUAKE/W. As a case study Khassa Chai dam is selected, it is located on Khassa Chai river and constructed of zoned embankment, it has a total length of 3.34 km. The selected earthquake for the analysis is El-Centro earthquake with a period of (10 sec) and different amplitudes of acceleration. The time of the analysis is taken as (600 sec.) with a time step (∆t = 0.05 sec.) to investigate the behavior of the soil for a period of time after the earthquake has stopped, a free vibration period is included in the analysis. It was concluded that, the value of pore water pressure generated at the base of the core is greater than that in the upper parts of dam, the horizontal and vertical effective stress continue to decrease during the period of analysis (600 sec) which indicates that the soil continues to weaken during this period, the horizontal displacement increases with depth of the point from the crest and the largest horizontal displacement will be at the base of the dam at time 60 sec and There is attenuation of the acceleration to some degree depending on the amplitude of the input horizontal acceleration.

Prediction of Surface Roughness and Material Removal Rate for 7024 AL-Alloy in EDM Process

Abbas Fadhil Ibrahim; Mostafa Adel Abdullah; Safaa Kadhim Ghazi

Engineering and Technology Journal, 2016, Volume 34, Issue 15, Pages 2796-2804
DOI: 10.30684/etj.34.15A.2

This paper studies prediction the values of MRR and surface roughness in Electrical discharge operations. It is a operation in which the material removal rate is machined with elevation spark in the midst work piece and electrode sunken through dielectric solution.Through use Taguchi found that the accuracy of the measured and prediction values that have been is 93% and 99% for each of the MRR and surface roughness respectively. The effect of different Electrical discharge machining factors are (Gap, pulse off time and pulse on time) to predict the (material removal rate) and (roughness). Note that connected pole that was used is copper. From (ANOVA) found that the large parameter effect on MRR is pulse-on 65% and pulse-off 25% while large parameter effect for surface roughness is pulse-on 96% . The least influential parameter for metal removal rate is the gap and the least influential parameter for surface roughness is pulse-off and Gap.

Comparison between Sand Columns and Sand Columns Stabilized with Lime or Cement with Stone Columns Embedded in Soft Soil

Ahmed S.A. Al-Gharbawi; Nawres A.A. Rajab

Engineering and Technology Journal, 2016, Volume 34, Issue 15, Pages 2805-2815
DOI: 10.30684/etj.34.15A.3

Sand and stone columns are used to improve bearing capacity of soft clayey soils… because of their stiffness which is higher than the soil was replaced, the compacted columns… produce shearing resistances which provide vertical support… for overlying structures… or embankments. Also the sand… and stone columns… accelerate the settlement… in the native surrounding soil… and improve the load settlement… characteristics… of foundation. The technique… consists of excavating… holes of specific… dimensions and arrangement… in the soft soil… and backfilling… them with either… sand or… stone particles.
The present work investigates the behavior of soft soil reinforced with group of stone columns, sand columns and sand columns stabilized with lime or cement. The percentage of lime and cement used in this research, were determined previously in papers of single sand column stabilized with lime and cement, 11% by weight lime and 9% by weight cement. The model tests were carried out on a soil with undrained shear strength ranging between 16-18 kPa. The models consist of eight… columns at area replacement ratio of (0.196) in square pattern, the holes 50 mm in… diameter and 300 mm… in length were excavated… in a bed… of soft soil. The holes… were backfilled… with stone, sand and sand… stabilized with lime or cement particles. Each group… of columns was loaded… gradually through… a rectangular… rigid footing, its dimensions… 400×200 mm with 50 mm thickness, up to failure… with continuous… monitoring of the settlement. The test… results are analyzed… in terms… of bearing improvement… ratio… and settlement reduction… ratio for all… columns… and in terms… of the stress… concentration… ratio and… stiffness ratio.
The results show that the improvement in bearing capacity was about 70% and 62% for sand columns stabilized by lime and cement respectively, and the improvement in bearing capacity was about 42% and 34% for sand columns stabilized by lime and cement compared with stone columns respectively.

On the use of GIS Technique to Analyze the Distribution of Primary Schools in Holy Karbala City

Noor Hashim Hameed

Engineering and Technology Journal, 2016, Volume 34, Issue 15, Pages 2816-2827
DOI: 10.30684/etj.34.15A.4

This paper analyzes the spatial distribution of primary schools in Karbala city based on geographic information system (GIS). GIS has the ability to solve numerous geographic problems effectively and easily and to make spatial analysis in combination with database systems. In this paper, data of educational facilities and population are collected via comprehensive statistics in Karbala city. This data has been utilized to build a geo data base for study area after processing it. Statistical and spatial analyses were applied. The analysis tools in Arc GIS9.3 software include (standard distance, directional distribution, nearest neighbor, auto correlation and accessibility indicator). These tools were used for analyzing patterns of distribution. Statically analysis results showed that there is an argent need to 31 boys’ primary schools and 30 girl’s primary schools within study area while spatially analysis results showed that nearest neighbor value of 1.19 which is dispersed for boys’ schools and 0.96 is random for girls’ schools. The correlations indicated 0.19 which is random for boys and girls schools. The Calculate Accessibility Indicator’s results showed there is a lack in achieving the Accessibility Indicator of most of the residential sectors.

Thermo-mechanical Fatigue (TMF) Behavior of Three Different Steel Alloys

Hussain J. Mohammed Al-Alkawi; Mohammed H. Ali; Shaimaa Ghazy Mezban

Engineering and Technology Journal, 2016, Volume 34, Issue 15, Pages 2828-2837
DOI: 10.30684/etj.34.15A.5

This paper presents the effect of temperature on the fatigue properties of carbon steel containing three different content of carbon: 0.758%C, 0.539%C and 0.319%C. The tests were conducted at room temperature and at variable temperatures. The temperature cycle used was in the range from 50oC to 100oC and 150oC respectively. Using constant amplitude loading, the fatigue test was done by rotating bending machine. The results obtained from the fatigue test at room temperature were compared with the fatigue test results at variable temperatures. A modified Miner rule was applied to predict the fatigue life at variable temperatures and to evaluate the fatigue damage in every steel alloy. The fatigue damage was determined as the number of cycles and stress. The results showed that the alloy steel with 0.539%C had the best resistance to the constant applied load and variable temperature and it was also found that the fatigue life of all three alloys decreased at variable temperature compared to room temperature.

Investigation of Hardness and Flexural Properties of PMMA Nano Composites and PMMA Hybrids Nano Composites Reinforced by Different Nano Particles Materials used in Dental Applications

Sihama E. Salih; Jawad K. Oleiwi; Alaa Mohammed.T

Engineering and Technology Journal, 2016, Volume 34, Issue 15, Pages 2838-2853
DOI: 10.30684/etj.34.15A.6

Poly methyl methacrylate (PMMA), widely used as a prosthodontic denture base, the denture base materials should exhibit good mechanical properties and dimensional stability in moist environment. In the present research, efforts are made to develop the properties of PMMA resin that used for upper and lower prosthesis complete denture, by addition four different types of nanoparticles, which are fly ash, fly dust, zirconia and aluminum that added with different ratios of volume fractions of (1%, 2% and 3%) to poly methyl methacrylate (PMMA), cold cured resin (castavaria) is the new fluid resin (pour type) as a matrix. In this work, the Nano composite and hybrid Nano composite for prosthetic dentures specimens, preparation was done by using (Hand Lay-Up) method as six groups which includes: the first three groups consists of PMMA resin reinforced by fly ash , fly dust and ZrO2 nanoparticles respectively, the second three groups consists of three types of hybrid Nano composites, which includes ((PMMA: X% nF.A)+ (1%Al + 3% ZrO2)), ((PMMA: X% nD.A)+ (1%Al + 3% ZrO2)) and ((PMMA - X%nZrO2)+(1%F.A + 3%F.D)) respectively. The hardness and flexural tests results show that the values of the hardness, flexural strength, Maximum shear stress and flexural modules increased and with the addition of Nano powders (fly ash, fly dust, zirconia, and aluminum). And the results showed that the maximum values of hardness reach to (84.166) for ((PMMA: 3%nZrO2) + (1%F.A + 3%F.D)) hybrid Nano composite, whereas the maximum values of hardness for Nano composite reach to (83.333) for (PMMA: 3%nZrO2) Nano composite. Also, the results showed that the maximum values of flexural strength and Maximum shear stress reaches to (101MPa) and (2.4738MPa) respectively for (PMMA: 2%nF.D) Nano composite. Moreover, the results showed that the maximum values of flexural modules reaches to (13.95GPa) for ((PMMA: 3% nF.A) + (1%Al + 3%ZrO2)) hybrid Nano composite, whereas the maximum values of flexural modules for Nano composite reach to (12GPa) for (PMMA-3%nZrO2) Nano composite.

Binary and Ternary Nanoceramic Coatings to Protect Carbon Steel in Artificial Seawater

Rana Afif Anaee; Ahmed M. Al- Ghaban; Douaa A. Abdullah

Engineering and Technology Journal, 2016, Volume 34, Issue 15, Pages 2854-2863
DOI: 10.30684/etj.34.15A.7

Binary and Ternary nanoparticles coatings have been applied on carbon steel using atomization method (cold spraying) to corrosion control in seawater. Nanoparticles were included Nano Al2O3, SiC and ZrO2. The characterization of coated surfaces has been investigated by AFM and SEM in addition to calculate the coating thickness. The binary coatings deal with 50%Al2O3-50%SiC, 50%Al2O3-ZrO2 and 50%SiC-50%ZrO2, while the ternary coating was 60%Al2O3-20%SiC-20%ZrO2.
The results showed that 50%Al2O3-50%SiC had the lowest thickness and most uniform distribution in AFM and SEM due to closing in particle sizes. Corrosion test achieved to estimate the corrosion resistance, protection efficiency and porosity percentage which indicated the role of Nano particle coating to corrosion control. These data showed that the Nano 50%Al2O3-50%SiC coating had the most noble corrosion potential, lowest corrosion current density (lowest corrosion rate), highest corrosion resistance, highest efficiency 99.651 % and lowest porosity percent 1.438×10-11. Cyclic polarization also estimated to show the probability for pitting corrosion. The coating with 50%Al2O3-50%SiC gave the highest breakdown potential equal to +69mV.

Proportioning of Foamed Concrete Reinforced with Carbon Fibers

Eethar Tihanon Dawood; Waleed Abdulrazzaq Abbas; Yahya Ziad Mohammad

Engineering and Technology Journal, 2016, Volume 34, Issue 15, Pages 2864-2876
DOI: 10.30684/etj.34.15A.8

This paper shows the production of foamed concrete reinforced with carbon fibers. Firstly, different mortar mixes were prepared by varying ratio of sand/cement. Continuously, the selected mortar mix was used for the foamed concrete produced due to the results of density, compressive strength, splitting tensile strength and flexural strength test. Secondly, different foam agent amounts (0.8, 1, 1.2 and 1.4 kg/m3) with 10% of silica fume were included in the selected mortar mix to produce the optimum foamed concrete mix depending on the same set of tests mentioned above. Lastly, various volumetric fractions of carbon fibers (0.5, 1 and 1.5%) were incorporated with the optimum foamed concrete mix and the same set of tests was done to examine such foamed concrete reinforced with carbon fibers.
The results give acceptable ranges of strength for mortar mix using 1.9 sand/cement ratios. Besides, the foamed concrete produced by the inclusions of foaming agent 1 kg/m3 shows acceptable ranges of density and strength to be suitable for the reinforcing by carbon fibers. The carbon fiber included in the foamed concrete exhibit significant increases for the strengths. Such increases are varied from about 35% using 1% carbon fibers to 44% and 116% using 1.5% carbon fibers for compressive, splitting tensile and flexural strength, respectively

Health Monitoring System for Ambulance Emergency System Using Wireless Sensor Network

Muayad Sadik Croock; Asmaa Shaalan Abdul Munem

Engineering and Technology Journal, 2016, Volume 34, Issue 15, Pages 2877-2890
DOI: 10.30684/etj.34.15A.9

The health sensor is one of the technologies of the Wireless Sensor Network for Medical (WSNFM), which has a wide range of sensors that can be used to check a person’s health data. In this work, a health sensor system is used to monitor a patient inside the ambulance along the way to the emergency department at a hospital. The system sends the vital readings to the emergency department using web based application and then save them in the server database. Two main types of sensors are used which are: body temperature and pulse rate sensors. The proposed system includes three main parts: hardware components at the ambulance, website, and SQL server at the hospital. The website is designed using and PHP environments, while the database at the hospital is built utilizing SQL server 2012 in addition to visual studio C# for graphical User Interfacing (GUI). Simply, the readings of sensors are transferred from the ambulance using the internet throughout a website to the SQL server at hospital. The achieved results show a superior performance of the presented system in obtaining the designed target as well as high accuracy and efficiency.

Effect of The Reinforcing by WC on Microhardness, Roughness and Corrosion Behavior of Al-12Si Alloy

Hiba Anwer Abdullah

Engineering and Technology Journal, 2016, Volume 34, Issue 15, Pages 2891-2896
DOI: 10.30684/etj.34.15A.10

This work investigated the effect of Tungsten Carbide as reinforcement with 1, 2 and 3 wt.% on some properties of matrix Al-12Si alloy. Al-12Si/WC composites were fabricated by stir casting method. Micro hardness and roughness have been tested to investigate the role of WC reinforcing. Corrosion behavior of these composites also investigated in 0.2M HCl solution using the potentiostat instrument.
The results show a good incorporation between the matrix and WC particles with probability to form Al12W and Al4C3 phase in addition to eutectic structure of Al-12Si alloy. The micro hardness was increased with increasing the weight percent of WC, while the roughness was decreased due to the better interfacial bonding. Corrosion protection properties of composites were better than that of base alloy due to the behavior of WC as a cathodic site which reduces the dissolution of metals from the metallic surface.

Development of a Swing-Tracking Sliding Mode Controller Design for Nonlinear Inverted Pendulum System via Bees-Slice Genetic Algorithm

Ahmed Sabah Al-Araji

Engineering and Technology Journal, 2016, Volume 34, Issue 15, Pages 2897-2910
DOI: 10.30684/etj.34.15A.11

A new development of a swing-tracking control algorithm for nonlinear inverted pendulum system presents in this paper. Sliding mode control technique is used and guided by Lyapunov stability criterion and tuned by Bees-slice genetic algorithm (BSGA). The main purposes of the proposed nonlinear swing-tracking controller is to find the best force control action for the real inverted pendulum model in order to stabilize the pendulum in the inverted position precisely and quickly. The Bees-slice genetic algorithm (BSGA) is carried out as a stable and robust on-line auto-tune algorithm to find and tune the parameters for the sliding mode controller. Sigmoid function is used as signum function for sliding mode in order to eliminate the chattering effect of the fast switching surface by reducing the amplitude of the function output. MATLAB simulation results and LabVIEW experimental work are confirmed the performance of the proposed tuning swing-tracking control algorithm in terms of the robustness and effectiveness that is overcame the undesirable boundary disturbances, minimized the tracking angle error to zero value and obtained the smooth and best force control action for the pendulum cart, with fast and minimum number of fitness evaluation.

Experimental Study of Spiral Heat Exchanger Performance in V- Trough Tube Collector by using Mono and Hybrid Nanofluids

Khalid Faisal Sultan

Engineering and Technology Journal, 2016, Volume 34, Issue 15, Pages 2911-2923
DOI: 10.30684/etj.34.15A.12

This article presents an experimental study of the performance of spiral heat exchanger in V – trough tube collector by using mono Nano fluid (metal and oxide metal) (Zn(30)+Dw),(ZrO2(60)+Dw) and hybrid Nano fluids (Zn(30)+ZrO2 (60)+Dw). The method used in this study to enhanced heat transfer and pressure drop by used the spiral tube heat exchange in V– trough tube solar collector and the mono Nano fluid (metal and oxide metal) and hybrid Nano fluids instead of the distilled water. The concentrations of mono and hybrid nanoparticles used are (1 , 3, 5 vol %). Three types of nanoparticles used in this paper Zinc (Zn (30nm)) , Zirconium oxide (ZrO2) (60nm)) and hybrid nanoparticles Zinc (Zn (30nm)) , Zirconium oxide in addition the pure fluid (distilled water). The impact of different parameters were taken in this article such as size and type, Dean Number, Reynolds number, concentration, mono and hybrid Nano fluids temperature on heat transfer coefficient and pressure drop. The results indicated that by using heat exchanger consist of shell and spiral tube enhanced the heat transfer performance and the pressure drop due to the curvature of the spiral tube. The heat transfer coefficient and pressure drop will increasing by using mono Nano fluid (metal and oxide metal) (Zn(30)+Dw), (ZrO2(60)+Dw) and hybrid Nano fluids (Zn(30)+ZrO2(60)+Dw) instead of the pure fluid (Dw). The experimental results showed that the maximum increase of 44.32% (Zn + Dw), 35.42% for (Zn +ZrO2 + Dw) and 25.13 % (ZrO2+ Dw) in Nusselt number ratio for a range of Reynolds numbers between 200 and 800. This study indicated that the mono Nano fluid (metal and oxide metal) (Zn+Dw),(ZrO2+Dw) and hybrid Nano fluids (Zn+ZrO2+Dw) are a Newtonian fluid as well as shear stress increases with shear rate. The shear stress of mono Nano fluid and hybrid Nano fluids increases with concentration of nanoparticles for both counter flow and parallel flow. The type and size mono and hybrid nanoparticles play an important role in enhancement of heat transfer rate. Further to the performance index are used to present the matched flow and heat transfer technique.

Optimal and Robust Tuning of State Feedback Controller for Rotary Inverted Pendulum

Hazem I. Ali; Rasha Mohammed Naji

Engineering and Technology Journal, 2016, Volume 34, Issue 15, Pages 2924-2939
DOI: 10.30684/etj.34.15A.13

This paper presents the design and implementation of optimal and robust state feedback controller for rotary inverted pendulum system. The Particle Swarm Optimization (PSO) method is used to find the optimal values of the state feedback gains subject to time response specifications and H_∞ constraints. To improve the tracking of the system, a robust state feedback plus integral controller is designed. The simulation results show that the proposed controller can effectively stabilize the pendulum at the upright position. Further, the proposed controller can compensate the variations in system parameters. The effectiveness of the proposed controller is verified experimentally using real rotary inverted pendulum.

Effect of Pulse on Time and Pulse off Time on Material Removal Rate and Electrode Wear Ratio of Stainless Steel AISI 316L in EDM

Shukry H. Aghdeab; Amani I. Ahmed

Engineering and Technology Journal, 2016, Volume 34, Issue 15, Pages 2940-2949
DOI: 10.30684/etj.34.15A.14

The electrical discharge machining (EDM) is one of the non-traditional cutting processes, used in many important applications such as dies and auto industry. This thesis focuses on the study of machining responses such as material removal rate (MRR) and electrode wear ratio (EWR) under the effect of different machining conditions in EDM process. The process parameters are pulse on time (Ton), pulse off time (Toff) and electrical current (Ip). The main purpose of this work is to achieve best MRR and least EWR using copper electrode with fixed diameter (10 mm) for the machining of stainless steel AISI 316L with a constant thickness (0.8 mm). Different values for the Ton (25, 50 and 75) µs, Toff (9, 18 and 25) µs and Ip (16, 30 and 50) A were used. The results of experiments showed the main effects of machining conditions on MRR and EWR. Where, the MRR increased with increasing the Ton, MRR decreased with increasing the Toff and MRR increased with increasing Ip. While, the EWR decreased with increasing the Ton, EWR decreased with increasing Toff until access to a specific Toff then EWR increased with longer Toff and EWR increased with increasing Ip. The maximum MRR is (48.16 mm3/min) at Ton (75 µs), Toff (9 µs) and Ip (50 A) and minimum EWR is (0.179 %) at Ton (75 µs), Toff (9 µs) and Ip (16 A). The results showed that the response surface methodology (RSM) that have been performed using Minitab 17 software. It can predict the machining responses with a good accuracy where it gave the coefficient of determination (R-sq) that determines the degree of fit between the experimental and predicted data. Higher value of R-sq shows a better fit. The values of R-sq are (97.46 %) for the MRR and (96.34 %) for EWR. Also, the SPSS 18 software was used to predict the machining responses with a good accuracy.

Distance Estimation Based on RSSI and Log-Normal Shadowing Models for ZigBee Wireless Sensor Network

Salim Latif Mohammed

Engineering and Technology Journal, 2016, Volume 34, Issue 15, Pages 2950-2959
DOI: 10.30684/etj.34.15A.15

In the last few years, a mobile wireless sensor and its application in wireless sensor network (WSN) are commonly used. Localization of a mobile sensor node is considered a critical issue in some WSN applications. In this paper, an outdoor environments experiment was carried out to measure the distance between the mobile node and the coordinator node in a simple point-to-point ZigBee WSN. The distance was determined based on the measured Received Signal Strength Indicator (RSSI) of the mobile node by the coordinator node. In addition, a Log-Normal Shadowing Model (LNSM) was derived for outdoor condition. Moreover, the parameters of the propagation channel such as standard deviation and a path loss exponent were estimated. The RSSI was measured and analysed for outdoor environments for a distance range 1-100 m. The measurements were carried out by using 2.4 GHz ZigBee wireless protocol based on XBee series 2 modules.
The results disclosed that the mean absolute error (MAE) of 3.44 and 6.72 m for a distance range 0-65 m and 0-100 m, respectively. These results point that the LNSM is only suited for short distance.

Optimization of Electrochemical Machining Process Based on Artificial Neural Network Technique

Noor Abd Al-Hassan; Shukry H.Aghdeab; Abbas F.Ibrahim

Engineering and Technology Journal, 2016, Volume 34, Issue 15, Pages 2960-2970
DOI: 10.30684/etj.34.15A.16

Electrochemical machining (ECM) is one of nonconventional machining process used to operation the most harsh materials that difficult to operate in conventional machining. This search has been used to study impact of different parameters on material removal rate (MRR) and to improve the MRR. The workpiece material in this search is stainless steel 316L, tool material from copper and NaCl (10, 25, 50) g/l was used as electrolyte. Through the experiments noted that the MRR increasing at increased current from (50 to 200) the increasing in MRR reach to 57.60%, also MRR increasing at increasing electrolyte concentration from (10 to 50) g/l increasing in MRR (reach) to 75.17 % and MRR decreasing at increased gap size from (0.5 to 1.5) mm the decreasing in MRR reach to 39.2 %. To predict the values of MRR and to get optimization, artificial neural network was used to get minimum mean squared error (MSE) and minimum average percentage error. In network, separated some values to training set and the remaining for testing set and it was noted that the predicated and experimental values are very close to each other.

Nitrogen Compounds Distribution in Diyala River Opposite Al-Rustimiyah Sewage Treatment Plants

Adnan A. Al-Samawi; Safaa N. H. Al-Hussaini

Engineering and Technology Journal, 2016, Volume 34, Issue 15, Pages 2971-2981
DOI: 10.30684/etj.34.15A.17

The reach of Diyala River just before its confluence with Tigris River south of the capital city Baghdad was taken as a case-study. This segment of Diyala River is exposed to multiple points of treated and raw municipal wastewater discharges of Al-Rustimiyah wastewater treatment plants. Its pollution status was assessed with regard to nitrogen compounds levels.
The aquatic parameters: DO, TN, TKN NH4-N, NH3-N, NO3-N, NO2-N, pH, and temperature were monitored and measured at nine sites along the river reach for a period of one year to assess seasonal variations. The first and last sites were chosen at the downstream and upstream of the points of pollution flowing into Diyala River, while the second to eighth sites were located at the effluents of the WWTPs of Al-Rustimiyah. It was found that water at sites two, seven, and four, respectively, were the most polluted points among all duo to the presence of the bypasses from the WWTPs at these sites.
With regard to NH4-N, NH3-N, and TN concentrations, the river was found to be heavily polluted with untreated wastewater at site two and between low to medium strength at other sites, except for site one. On the other hand, NO3-N and NO2-N concentrations categorized the river water as an effluent rather than a stream according to Iraqi standard classification.
Reversed relations were found between the DO concentrations and some of the nitrogen compounds and temperature. A statistical model relating TN concentration to DO, NH3-N, and temperature was derived. It was proved to be accurate.

Study of Stress Intensity Factor in Corrugated Plate Using Extended Finite Element Method (XFEM)

Rafil Mahmood Laftah

Engineering and Technology Journal, 2016, Volume 34, Issue 15, Pages 2982-2992
DOI: 10.30684/etj.34.15A.18

The presence of crack with different lengths and locations in structure of corrugated plate is studied. XFEM is along with enrichment function based on partition of unity is used for the calculation of stresses due to the presence of crack. Stress intensity factors (KI) and relations for shape factors (C) are calculated for the four most common crack orientations and loading conditions. Results showed that crack in the flange with load perpendicular to corrugation direction yields higher values of KI and C in addition to wider spread of stress concentration contours than the web. When loading becomes parallel to corrugation direction, the stress intensity factor and C factor become remarkably less due to the corrugation stiffness. Third mode KIII is appeared in the fourth case in addition to the presence of the first mode KI due to 45o inclination of the web and applied load direction

The Role of Bio-Analogy in Contemporary Architecture

Wijdan Deyaa Abdul Jalil

Engineering and Technology Journal, 2016, Volume 34, Issue 15, Pages 616-631
DOI: 10.30684/etj.34.15A.19

Human's attitude to nature has been changing through history. This was reflected on architecture, associated with each historical period, connected to availability of appropriate technology, where architecture was to protect man, give him a sense of security, luxury or controlling of nature. However, nature has been considered as a major source of inspiration through analogy of organism, which remained effecting until the industrial revolution and the emergence of other sources of analogies like machines and other. The contemporary period witness an attitude towards returning back to nature through bio-analogies, which appeared in many contemporary architectural trends by the impact of new scientific theories like fractional geometry, chaos theory, self-generation,…etc., associated by the revolution in digital technology and manufacturing. In addition to the emergence of the urgent need to achieve sustainability, which affected strongly in this direction that seeks to improve their aesthetic, functional and structural values. In spite of the multiplicity of these trends, they share the attitude to nature as source of inspiration through bio-analogy. So the problem of search is emerged as "the need to identify levels of bio- analogies in contemporary architecture". And the goal of research is determined as "identifying levels of bio-analogies in contemporary architecture". In light of that, the search classification levels of bio-analogies, and its relation to the characteristics of organisms in each level, and then extract their vocabularies to measure the application in contemporary architectural practice through the projects that are selected as case studies. The research found that they have achieved certain vocabularies and not others.

Quality Control System for Rehabilitation of Defected Reinforced Concrete Structures

Shakir A. Saheh; Tareq A. Khaleel; Ali Raid Saleem

Engineering and Technology Journal, 2016, Volume 34, Issue 15, Pages 632-643
DOI: 10.30684/etj.34.15A.20

The construction sector is facing many responsibilities and most importantly ensure implementation according to specifications and plans in order to ensure the safety of the structure and avoid any failures during or after the implementation or after, because the defects and failures is one of the reasons which will lead to delays in the implementation of project, or may stop the work for reasons related to the safety of structure, workers, and materials, which will lead to increase the cost of the project (the cost of repairs, tests, and stop). The theoretical part of the study dealt with display literature and publications and previous studies related to the failures and the reasons for their occurrence and methods of treatment, and the role of project management in control the failures.
In the practical part, the researcher display case studies of failures and the reasons for their occurrence, also the role of the administration diagnosis and treatment. In addition to the preparation of personal interviews with a number of project managers in construction field of reinforced concrete structures to see the most important failures faced by structures, and what are the measures taken in the diagnosis, control and prevention, also a scientific questionnaire has been prepared depending "on the information obtained from personal interviews, then the proposed administrative system has been built to control the failures and defects in reinforced concrete structures by treating all weaknesses that have been obtained through the questionnaire and personal interviews. The proposed administrative system was applied through a computer program, it can be used by project management in a flexible and easy way, and also it helps to avoid the occurrence of any failure during and after implementation. Also it identifies failures to be controlled during implementation and after the completion of the project. Additionally the factors that helped to achieve quality in implementation have been identified.

A Comparison Between Static and Dynamic Load Tests on Bored Piles

Makki K .Al-Recaby

Engineering and Technology Journal, 2016, Volume 34, Issue 15, Pages 2993-3004
DOI: 10.30684/etj.34.15A.21

Pilesr are both statically and dynami cally tried to acquire the limit and to check outline. The two sorts will give comes about that may differ in light of the technique utilized as a part of leading the test. It is thusly, important to think about the aftereffects of a static load test with dynamic load test. Numerous comparison studies are directed around the world, yet the vast majority of them are for displacement driven pile. In this way, the consequences of the test are looked at for substitution-exhausted piles. The piles are tested statically before dynamic test. The test results show that a not too bad comprehension was expert between both the tests with in addition to less 7mm at design load regarding settlement. Moderately, the settlement foreseen in powerful load test is littler diverged from static load test. Regarding absolute bearing limit, Davisson's technique gives the insignificant outrageous load regard diverged from various strategies. The Davisson's strategy is utilized to analyze the outcomes since it is more moderate. The examination shows that the piles are inside 15% in regard as far as possible traversed Davisson's strategy. Since the static test was coordinated before unique test, the limit got from dynamic test is higher because of the pile experienced flexible pressure amid static load test and furthermore because of soil setup.