Table of content

Journal of Engineering

مجلة الهندسة

ISSN: 17264073
Publisher: Baghdad University
Faculty: Engineering
Language: Arabic and English

This journal is Open Access

About

The Journal Engineering was issued in 1986. It was Stopped from 1990 – 1997 because of the economic blockade. It restarted publication after the fourth scientific engineering conference for it published the papers that were accepted in the conference.
It is a scientific engineering journal refereed by specialized and qualified professors in most of the engineering fields and those Specialists in the issued by the college of Engineering university of Baghdad .It was serenely publibued , but from 2011 it has issued of monthly for the numerous papers submitted to the journal to publish their papers in this scientific journal in addition to some of the Arabs professors because the journal is considered one of the valued journals in the Arabic homelan .
Many professions were the head editor of the journal from its first issue. The first one was prof.dr. Laith Ismail Namiq then prof.dr. Mohammed A.Alawis ,prof.dr.Ali A Al – kilidar prof.dr. Abdul-Ilah Younis and currently Prof.dr.Qais S. Ismail.

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Jadriyah, Baghdad
Iraq
Mobile:
Email: joengbag@uobaghdad.edu.iq

Table of content: 2016 volume:22 issue:6

Article
Management Model for Evaluation and Selection of Engineering Equipment Suppliers for Construction Projects in Iraq
نموذج اداري لتقييم واختيار مجهزي المعدات الهندسية في المشاريع الانشائية في العراق

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Abstract

Engineering equipment is essential part in the construction project and usually manufactured with long lead times, large costs and special engineering requirements. Construction manager targets that equipment to be delivered in the site need date with the right quantity, appropriate cost and required quality, and this entails an efficient supplier can satisfy these targets. Selection of engineering equipment supplier is a crucial managerial process .it requires evaluation of multiple suppliers according to multiple criteria. This process is usually performed manually and based on just limited evaluation criteria, so better alternatives may be neglected. Three stages of survey comprised number of public and private companies in Iraqi construction sector were employed to identify main criteria and sub criteria for supplier selection and their priorities.The main criteria identified were quality of product, commercial aspect, delivery, reputation and position, and system quality . An effective technique in multiple criteria decision making (MCDM) as analytical hierarchy process (AHP) have been used to get importance weights of criteria based on experts judgment. Thereafter, a management software system for Evaluation and Selection of Engineering Equipment Suppliers (ESEES) has been developed based on the results obtained from AHP. This model was validated in a case study at municipality of Baghdad involved actual cases of selection pumps suppliers for infrastructure projects .According to experts, this model can improve the current process followed in the supplier selection and aid decision makers to adopt better choices in the domain of selection engineering equipment suppliers.


Article
Application of Total Quality Management (TQM) Requirements in Risk Management in Construction Projects in Iraq
تطبيق متطلبات ادارة الجودة الشاملة في ادارة المخاطر في المشاريع الانشائية في العراق

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Abstract

Total quality management considers one of the modern scientific entrances which practiced by productivity service organizations alike to provide appropriate quality required outputs according to the needs and desires of customers manage , enable the organization seeking to continue and grow in light of the increasing competition from the satisfy and provide the appropriate total quality management requirements whenever led to face risks that they may have in a manner in which they can be addressed and find ways to avoid them in the future when repeated. The research has consist of two main parts firstly have included a review of the most important concepts of total quality management in addition to the concept of risk analysis and management in construction projects and how to apply the concept of total quality management in the risk analysis and management. Second part included the practical part of the research, which was open and closed questionnaire for experts in the construction industry to obtain required informations for the application of total quality management requirements in risk management in construction projects in Iraq. One of the main findings of the research is that top management support has a high impact on risk management in addition to continuous improvement, training and education, while the participation of all employees in the organization and constant stimulation and focusing on the customer as one of the total quality management requirements had a moderate impact on risk management.


Article
Passive Design Strategies to Enhance Natural Ventilation in Buildings "Election of Passive Design Strategies to Achieve Natural Ventilation in Iraqi Urban Environment with Hot Arid Climate"
الستراتيجيات التصميمية المنفعلة لتعزيز التهوية الطبيعية في الأبنية "إنتخاب الستراتيجيات التصميمية المنفعلة لتحقيق التهوية الطبيعية في البيئة العمرانية العراقية ذات المناخ الحار الجاف"

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Abstract

The natural ventilation in buildings is one of effective strategies for achieving energy efficiency in buildings by employing methods and ways of passive design, as well as its efficiency in providing high ranges of thermal comfort for occupants in buildings and raises their productivity. Because the concept of natural ventilation for many people confined to achieve through the windows and openings only, become necessary to provide this research to demonstrate the various passive design strategies for natural ventilation. Then, research problem: Insufficient knowledge about the importance and mechanism of the application of passive design strategies for natural ventilation in buildings. The research objective is: Analysis of passive design strategies to achieve natural ventilation in buildings, for the purpose of the proper selection of them to Iraqi urban environment. Accordingly, the research included two parts: First, the theoretical part, which dealt with the conceptual framework of natural ventilation and deriving the most important aspects in it, in order to adopted as a base for the practical part of the research. Second: the practical part, which analyzed examples of buildings projects that employed various design strategies for natural ventilation, according to the theoretical framework that has been drawn. The main conclusion is, Necessity to adopt various passive design strategies for natural ventilation in Iraqi urban environment with hot dry climate, as they have a significant impact in reducing the energy consumption for the purposes of ventilation and cooling, as well as for its efficiency in improving air quality in indoor environments of buildings.


Article
Experimental Investigating of Unsupported Excavation Considering Its Effect on a Nearby Axially Loaded Pile
التحليل المختبري للحفريات غير المسندة مع مراعاة تاثيرها على ركيزة عمودية محملة رأسيا مجاورة

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Abstract

An experimental model is used to simulate the loss of soil lateral confinement due to excavation nearby an individual axially loaded pile. The effects of various parameters, such as the horizontal distance of excavation, depth of excavation and pile slenderness ratios are investigated. The experimental analysis results showed the effect of excavation is more remarkable as the horizontal distance of excavation becomes closer to the pile than half pile length. The effect of excavation diminishes gradually as the horizontal distance increases beyond that distance for all the investigated pile slenderness ratios and depths of excavation. The pile head deflection, settlement and bending moments along pile increase with decreasing horizontal distance between excavation face and adjacent axially loaded pile of various depths of excavation and pile slenderness ratios. The location of maximum bending moment is positioned between 1/4 and 1/2 of pile length for all horizontal distance of excavation, depth of excavation and slenderness ratios. The bending moment profiles indicate a (single curvature) for medium flexible piles and (double curvature) for very flexible piles for different horizontal distance between excavation face and adjacent axially loaded pile and various depths of excavation. In addition the theoretical approach of wood, 2004 showed good agreement especially for very flexible pile (slenderness ratio ˃45).


Article
Seismic Effects and Static Analysis for the Artificial Damped Outrigger Systems in Tall R.C Buildings
التأثيرات الزلزالية والتحليل الأستاتيكي لأنظمة دعامة الإخماد الاصطناعي في المباني الخرسانية المسلحة العالية

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Abstract

This paper studies the combination fluid viscous dampers in the outrigger system to add supplementary damping into the structure, which purpose to remove the dependability of the structure to lower variable intrinsic damping. It works by connecting the central core, comprising either shear walls or braced frames, to the outer perimeter columns. The modal considered is a 36 storey square high rise reinforced concrete building. By constructing a discrete lumped mass model, and using frequency-based response function, two systems of dampers, parallel and series systems are studied. The maximum lateral load at the top of the building is calculated, and this load will be applied at every floor of the building, giving a conservative solution. For static study Equivalent Lateral Force (ELF) was conducted. MATLAB software, has been used in this study. From analysis data, it is observed that the parallel system of dampers result lower amplitude of vibration and achieved more efficiently compared to the series system, and the horizontal displacement for each configurations by using MATLAB software is less than the analytical solution using a uniformly distributed load of 36 nodal point forces that divided the total height.


Article
Recycling of Reclaimed Asphalt Concrete Using Warm Asphalt Mixture and Emulsified Asphalt Cationic
اعادة تدوير الخرسانة الاسفلتية المستصلحة باستخدام الخلطة الاسفلتية الدافئة والمستحلب الاسفلتي الكاتيونك

Authors: Hussein Hamel Zghair
Pages: 51-65
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Abstract

Warm asphalt mixture (WMA) and reclaimed asphalt pavement (RAP) are the most memorable sustainable materials in world of asphalt concrete pavements . This research aims to study the warm asphalt mixture for different types of filler materials such as ordinary cement and limestone dust. Beside, this research focused on the test of emulsified asphalt properties by evaluating the performance of warm asphalt mixture by Marshall Stability properties as well as moisture sensitivity. The results of this experiment provided many important points. First, The cationic emulsified asphalt is suitable with RAP aggregate for production warm asphalt mixtures .Second, The effective mixing procedure for warm asphalt mixtures consists heating the RAP aggregate at 100 Co and then mixing with emulsified asphalt. Because of heating of reclaimed asphalt pavement material can improve the dispersion as well as densification significantly. Furthermore, the warm asphalt mixtures containing filler of cement type improved the Moisture sensitivity performance by mean of increasing tensile strength ratio furthermore enhanced Marshall properties .Finally, It was indicated that optimum asphalt content (2.8%) is the best percentage found based on trail mixes ranging from (1.8 to 3.8) %


Article
Entropy Generation of Shell and Double Concentric Tubes Heat Exchanger
العشوائية المتولدة لمبادل حراري من نوع الغلاف والأنابيب المزدوجة المتحدة المركز

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Abstract

Entropy generation was studied for new type of heat exchanger (shell and double concentric tubes heat exchanger). Parameters of hot oil flow rate, temperature of inlet hot oil and pressure drop were investigated with the concept of entropy generation. The results showed that the value of entropy generation increased with increasing the flow rate of hot oil and when cold water flow rate was doubled from 20 to 40 l/min, these values were larger. On the other hand, entropy generation increased with increasing the hot oil inlet temperature at a certain flow rate of hot oil. Furthermore, at a certain hot oil inlet temperature, the entropy generation increased with the pressure drop at different hot oil inlet flow rates. Finally, in order to keep up with modern technology, infrared thermography camera was used in order to measure the temperatures. The entropy generation was determined with lower values when infrared thermography camera was used to measure the temperatures, compared with the values obtained by using thermocouples.


Article
Investigation the Optimum Combined Dosages of Date Seeds Powder as Natural Coagulant with Chemical Coagulants in Domestic Wastewater Pretreatment.
إيجاد التراكيز المشتركة المثلى من مسحوق نوى التمر كمخثر طبيعي مع المخثرات الكيمياوية في المعالجة التمهيدية لمياه الصرف الصحي.

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The pretreatment process can be considered one of the important processes in wastewater treatment, especially coagulation process to decrease the strength of many pollutants. This paper focused on using powdered date seeds as natural coagulant in addition to chemical coagulants (alum and ferric chloride) to find the optimum dosage of each coagulant that makes efficient removal of turbidity and chemical oxygen demand (COD) from domestic wastewater as a pretreatment process, then finding the optimum combined dosages of date seeds with alum, date seeds with ferric chloride that make efficient removal for both pollutants. Concerning turbidity, the optimum dosage for date seeds, alum and ferric chloride were 40 mg/l (79%), 70 mg/l (84%) and 60 mg/l (82%) respectively. Concerning COD the optimum dosage for date seeds, alum, and ferric chloride were 40 mg/l (75%), 60 mg/l (83%) and 50 mg/l (86%). The study showed that the optimum combined dosage that made higher turbidity removal (95%) resulted from mixing 70 mg/l date seeds with 50 mg/l alum, while for higher COD removal 90% resulted from mixing 40 mg/l date sees with 70 mg/l ferric chloride.


Article
Experimental and Simulation for the Effect of Partial Shading on Solar Panel Performance
التجربة والمحكاة لتأثير الظل الجزئي على أداء اللوح الشمسي

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Partial shading is one of the problems that affects the power production and the efficiency of photovoltaic module. A series of experimental work have been done of partial shading of monocrystalline PV module; 50W, Isc: 3.1A, Voc: 22V with 36 cells in series is achieved. Non-linear power output responses of the module are observed by applying various cases of partial shading (vertical and horizontal shading of solar cells in the module). Shading a single cell (corner cell) has the greatest impact on output energy. Horizontal shading or vertical shading reduced the power from 41W to 18W at constant solar radiation 1000W/m2 and steady state condition. Vertical blocking a column of cells (9 cells) in a module reduces the power from 41W to 18W (53% power reduction); while, blocking one or two cell in the row reduces the power from 41 W to 18W (53% power reduction). Shading three or four cells in the same row reduces the power from 41W to 1W or 0.006W (94% power reduction). A complete Matlab / Simulink model are achieved to simulate the effect of partial shading on power output of module. It is found that shading a single cell reduces the power from 50 W to 25 W (50%) using Matlab/Simulink model. Comparisons have been made between the I-V and P-V characteristic curves from the simulation with the practical (experimental) curves. The results showed that the percentage of error between the Simulink results and the corresponding experimental measurement are 22% without shading effect and, 32% with partial shading.


Article
The Effects of Inclination and Compounds Angles of Round Holes in Staggered Rows on Adiabatic Film Cooling Effectiveness of Vane Suction side
تاثيرات زوايا الميل والدوران للثقوب الدائرية في الصفوف المتخالفة على كفاءة التبريد الغشائي لجانب السحب من ريش التوجيه الرئيسية في التوربين

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The aim of this work is oriented to increase film cooling effectiveness value through numerical investigations for flow of Mach number not more than 0.3 around vane surface, to find the effects of inclination and compounds angles of round holes in staggered rows on adiabatic film cooling effectiveness of vane suction side. Multi cylindrical film cooling hole cases were studied with pitch ratio P/d =2 and 3, local blowing ratios M=0.382, 0.77 and 1.14, inclination angles =30° and 45°, compound angles β= 0°, 15°, 30° and 45° and local momentum ratios I= 0.084, 0.34 and 0.756 for better cooling process. A numerical technique, using ANSYS-FLUENT version 14.5, was used to solve governing partial differential equations of mass, momentum (Navier Stokes equations) and energy conservations in three dimensions with a v^2-f turbulence model that involves the solution of the four transport equations. Based on the results of the numerical solution, the best film cooling configuration, blowing ratio, with the range of actual engine flow conditions, dimensions and vane geometry; density ratio 1.74 , temperature ratio 0.57 and blowing ratio M=0.382, 0.77 and 1.14 was obtained. The best case for inclination angle =30°, P/d=2 was at M=1.14 and β=0° for the total average effectiveness along 60L/d of surface suction side was 0.616, while the best case for inclination angle =45°, P/d=2 was at M=0.382 and β=30° for the total average effectiveness along 60L/d of surface suction side was 0.516. In addition, comparisons were performed with available other work, where the experimental total average effectiveness results of Dees et al., 2011 were in good agreements with the numerical results of current work with a maximum deviation of 9.9% at I=0.34 and 3.6% at I=0.75.


Article
A Novel Analytical Model to Design Piezoelectric Patches Used to Repair Cracked Beams
نموذج تحليلي جديد لتصميم الصفائح الكهروضغطية المستخدمة لأصلاح العتبات الحاوية على تصدعات

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In this paper, an analytical solution describing the deflection of a cracked beam repaired with piezoelectric patch is introduced. The solution is derived using perturbation method. A novel analytical model to calculate the proper dimensions of piezoelectric patches used to repair cracked beams is also introduced. This model shows that the thickness of the piezoelectric patch depends mainly on the thickness of the cracked beam, the electro-mechanical properties of the patch material, the applied load and the crack location. Furthermore, the model shows that the length of the piezoelectric patches depends on the thickness of the patch as well as it depends on the length of the cracked beam and the crack depth. The additional flexibility of the beam caused by crack is modeled depending on a dimensionless parameter identified from finite elements method. Different piezoelectric patches were designed and investigated using analytical and finite elements models. The results show that increasing the patch thickness enhances the beam resistance to crack and load effects, while increasing the length of the piezoelectric patch reduces the magnitude of the voltage required to repair the cracked beam.


Article
Accuracy Evaluation of Digital Elevation Model Created Using Handheld Global Positioning System Receivers
تقييم دقة نموذج الارتفاع الرقمي المنتج بأستخدام متسلمات نظام تحديد المواقع العالمية المحموله

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This study aims to assess the accuracy of digital elevation model (DEM) created with utilization of handheld Global Positioning System (GPS) and comparing with Advanced Spaceborne Thermal Emission and Reflection Radiometer Global Digital Elevation Model (ASTER GDEM), version 2. It is known that the quality of the DEM is affected by both of accuracy of elevation at each pixel (absolute accuracy) and accuracy of presented morphology (relative accuracy). The University of Baghdad, Al Jadriya campus was selected as a study area to create and analysis the resulting DEM. Additionally, Geographic Information System (GIS) was used to visualize, analyses and interpolate GPS track points (elevation data) of the study area. In this research, three additional DEMs were created using 60%, 30% and 15% of the all GPS track points to deduce the effect of the number of the included points on the accuracy of the resulting DEM. The study findings show a high resolution for the resulting DEM less than 5m when taking into consideration all GPS tracking points that observed in this research. Moreover, the resulting DEM has relative accuracy better than absolute accuracy and reaches to around 2m. By comparing with ground control points (reference points), the quality of handheld GPS DEM shows considerable improvement better than ASTER GDEM. Thus, this study indicates to improve the accuracy level of handheld GPS DEM by about 40% with increasing the observed number of GPS track points to twice.


Article
Reducing Lost Circulation Problem by Using Rice Material
تقليل مشكله فقدان سائل الحفر باستخدام ماده الرز

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Drilling fluid loss during drilling operation is undesirable, expensive and potentially hazardous problem. Nasiriyah oil field is one of the Iraqi oil field that suffer from lost circulation problem. It is known that Dammam, um-Radoma, Tayarat, Shiranish and Hartha are the detecting layers of loss circulation problem. Different type of loss circulation materials (LCMs) ranging from granular, flakes and fibrous were used previously to treat this problem. This study presents the application of rice as a lost circulation material that used to mitigate and stop the loss problem when partial or total losses occurred. The experimental work included preparing drilling fluid, which is selected to be water based mud. Amount of loss for rock samples was measured where the percentage of losses of drilling mud were 46.25% and 96.96% as well as the percentage of improvement in curing of lost circulation were calculated after rice adding. Rice materials addition was done by tow stages: a) Adding 24 Ib/bbl of fine rice and 1 Ib/bbl of course rice gave improvement in curing from 30.67% to 100%. b) Adding 24 Ib/bbl of fine rice and 6 Ib/bbl of course rice gave an improvement in curing equal to 92.12%.

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