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
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Email: joengbag@uobaghdad.edu.iq

Table of content: 2015 volume:21 issue:1

Article
Properties of Superpave Asphalt Concrete Subjected to Impact of Moisture Damage
خصائص الخرسانة الاسفلتية فائقة الاداء المعرضة لتأثير الضرر بالرطوبة

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Abstract

Moisture damage is a primary mode of distress occurring in hot mix asphalt (HMA) pavements in Iraq. Because of the loss of bond, or stripping, caused by the presence of moisture between the asphalt and aggregate, which is a problem in some areas and can be severe in some cases, it is requires to evaluate the design asphalt mixture to moisture susceptibility. Many factors such as aggregate characteristics, asphalt characteristics, environment, traffic, construction practices and drainage can contribute to stripping. Asphalt concrete mixes were prepared at their optimum asphalt content by superpave system and then tested to evaluate their engineering properties, which include tensile strength, resilient modulus, and permanent deformation, stiffness, and fatigue characteristics. These properties have been evaluated using indirect tensile strength, uniaxial repeated loading and repeated flexural beam. The experimental results, in general, showed that the mixes subjected to moisture damage give low resistance to indirect tensile strength, low resilient modulus at 40 ̊ C, high permanent deformation at 40 ̊ C, low stiffness, and low fatigue life, by (19%, 21%, 93%, 62% and 70%) respectively as compared with unconditioned mixture.


Article
Experimental Study of the effect of closed cavity wall on buildings cooling loads saving
دراسة عملية لتأثير الجدار ذي التجويف الهوائي المغلق في تخفيض احمال تبريد الابنية

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Abstract

The experimental study showed the use of closed cavity wall (the thickness of the cavity 5cm) made a percentage reduction in the cooling load caused by heat gain from the wall by (21.5 %) compared with the conventional wall. also the thermal resistance of the closed cavity was an average (0.2 m2.oC/W). The experimental results of the study showed that the use of closed cavity wall reduced the average temperature of the inner surface of the wall during the day, and that the reduction was an average (0.45 oC) when compared with the conventional wall , as well as the use of closed cavity wall reduced the temperature difference range of the inner surface of the wall during the day, and that the reduction was an average (0.66 oC) when compared with the conventional wall .


Article
Performance Improvement of the Implementation of Concrete Structures in the Construction Sector In Iraq Using The Modern Management Technique “Six Sigma”
تطوير أداء تنفيذ الهياكل الخرسانية في قطاع التشييد في العراق باستخدام التقنية الإدارية الحديثة (Six Sigma)

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Abstract

The reality of the field of construction projects in Iraq refers to needing for the development of performance in order to improve quality and reduce defects and errors and to control the time and cost, so there is needing for the application of effective methods in this area, one of the methods that can be applied in this area is the manner of Six Sigma. This research aims to enhance the performance and quality improvement for the construction projects by improving performance in the work of the implementation of the concrete structure depending on the Six Sigma methodology, and for the purpose of achieving the aim of the research, the researcher firstly depends on the theoretical study that include the concepts of quality and the Six Sigma methodology as a system aims to reduce defects and improve the quality and secondly on the field study carried out by the researcher through conducting the open questionnaire that include interviews conducted by the researcher with a slice of engineers experienced in the implementation of construction projects that leads to design closed questionnaire included the major axes of the research and distributed on a selected sample of engineers with expertise in this area. The researcher applying the (DMAIC) methodology is one of the methods adopted for the application of Six Sigma on the case study (the project of structures laboratory at University of Baghdad) for the purpose of identifying the most important defects that may appear in the implementation of the concrete structure and assess the quality of implementation of the concrete structure and then analyzing the causes of these defects and propose procedures to enhance the performance and quality improvement depending on the field survey was conducted. The most important research conclusions are sigma level for the case study is 2.35 and the number of defects per million opportunities is 211905 and this Sigma level is very small which indicates the low level of quality for the case study.


Article
Corrosion Study of the Injection Equipments in Water in Al-Ahdeb Wells ‐Iraq
دراسة تأكل معدات الحقن في الماء في حقول الاحدب – العراق

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Abstract

Water injection equipments such as pipelines, which are used in the second recovery of oil in the Al-Ahdeb wells, suffer from the corrosion in water during maintaining vacuum deoxygenated tower that used to decrease concentration of the dissolved oxygen gas in the water from 6.2-9.1 ppm to o.5 ppm. This study involved calculation the corrosion rates of the internal surfaces of the pipelines either during operation of the vacuum unit or when the tower out of operation. Finally, find the solution by one of the following suggestions. In the first suggestion removal of the dissolved O2 from water is achieved by increasing the dosage of the oxygen scavenger (sodium sulphite). The second suggestion involves removing the dissolved O2 from water by bubbling the oxygenated water with nitrogen gas. The study showed that the corrosion rates of various inside diameter pipelines are between 0.13 mm/yr and 1.5 mm/yr during operation of the vacuum tower and between 3.2 mm/yr and 18.5 mm/yr when the tower out of the operation. While the results showed that the corrosion rate of the pipelines when the tower out of operation reached to the acceptable value of 0.1 mm/y when the dissolved oxygen in the injected water removed by increasing the dosage of the sodium sulphite (Na2SO3) to 48-72 ppm. The results also explained that corrosion rates of the pipelines reached to 0.5 mm/y when the dissolved oxygen removed by bubbling the water with nitrogen gas.


Article
Wastewater Bio-solids Management for Fertilizer Quality Using Co- composting Process
ادارة حمأة مياه الصرف الصحي لتحسين قيمتها السمادية باستخدام طريقة التحلل البايولوجي المترافق

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Abstract

Co-composting process can be acquired by combining organic fraction of municipal solid waste (OFMSW) with sewage sludge (SS) and mature compost (MC) as enhancement and bulking agent to overcome the problems of municipal solid waste and wastewater treatment plants besides the finally produced fertilizer usage for agriculture and horticulture. The effects of different mixture ratios of (OFMSW), (SS) and (MC) on the performance of composting process were investigated in this study. Piles of about 10 kg were prepared by mixing OFMSW, SS and MC in three different ratios (w/w) [OFMSW: SS: MC= 3:1:1, 3:2:1, and 3:3:1]. Results showed that the pile [3:1:1] was most beneficial to composting. The final compost products contained a C/N ratio (12.17), nitrification index (N-NH4/N-NO3) (0.2), organic matter degradation (36%), N content (1.75%), and Germintation Index (GI) 77.4%. Final compost showed low amounts of heavy metals, and significant reduction of pathogens indicating mature and stable bio-mass


Article
Formal Characteristics of the Architectural Type of contemporary Mosques within the concept of Topology
الخصائص الشكلية للنمط المعماري للمساجد المعاصرة في ضوء مفهوم الطوبولوجية

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Abstract

Mosques could be considered as one of the most powerful architectural types throughout historical ages. With their highly symbolic formal legacy, Mosques play an essential role in providing the Islamic city with its special identity. Nevertheless, the advent of digital technology and its ubiquity at different levels of architectural design marked the emergence of new tendencies in the Architecture of Mosques, represented by various models added to the storage of this architectural type. Consequently a review of these tendencies would be needed, aiming at pointing out the formal transformations and new suggested characteristics. The paper investigates the surviving and the disappearing formal components of the Mosque Type, and reviews the different ways they are contemporarily employed within the notion of Topology in Architecture. This is achieved through the study and analysis of several examples of contemporary mosques , with comparison to the development of the formal components undergone by the Mosque type.


Article
Extraction of heavy metals from contaminated soils using EDTA and HCl
انتزاع المعادن الثقيلة من التربة الملوثة باستخدام EDTA و HCl

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Abstract

The present study examines the extraction of lead (Pb), cadmium (Cd) and nickel (Ni) from a contaminated soil by washing process. Ethylenediaminetetraacetic acid disodium salt (Na2EDTA) and hydrochloric acid (HCl) solution were used as extractants. Soil washing is one of the most suitable in-situ/ ex-situ remediation method in removing heavy metals. Soil was artificially contaminated with 500 mg/kg (Pb , Cd and Ni ). A set of batch experiments were carried out at different conditions of extractant concentration , contact time, pH and agitation speed. The results showed that the maximum removal efficiencies of (Cd, Pb and Ni ) were (97, 88 and 24 ) % respectively using ( 0.1 M) Na2EDTA. While the maximum removal efficiencies using (1M) HCl were (98, 94 and 55)% respectively. The experimental data of batch extraction were applied in four kinetic models; first order, parabolic diffusion, two constant and Elovich model. The parabolic diffusion was the most fitted to the experimental data.


Article
Shell and Double Concentric Tube Heat Exchanger Calculations and Analysis
الحسابات والتحاليل للمبادل الحراري ذو القشرة والانابيب المتداخلة المتمركزة

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Abstract

This study concerns a new type of heat exchangers, which is that of shell-and-double concentric tube heat exchangers. The case studies include both design calculations and performance calculations. The new heat exchanger design was conducted according to Kern method. The volumetric flow rates were 3.6 m3/h and 7.63 m3/h for the hot oil and water respectively. The experimental parameters studied were: temperature, flow rate of hot oil, flow rate of cold water and pressure drop. A comparison was made for the theoretical and experimental results and it was found that the percentage error for the hot oil outlet temperature was (- 1.6%). The percentage errors for the pressure drop in the shell and in the concentric tubes were (17.2%) and (- 39%) respectively. For cold water outlet temperature, the percentage error was (- 3.3%), while it was (18%) considering the pressure drop in the annulus formed. The percentage error for the total power consumed was (-10.8%). A theoretical comparison was made between the new design and the conventional heat exchanger from the point of view of, length, mass, pressure drop and total power consumed.


Article
A Visual Interface Design for Evaluating the Quality of Google Map Data for some Engineering Applications
لبعض التطبيقات الهندسيةGoogle mapتصميم برنامج لتقييم جودة بيانات

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Abstract

Today, there are large amounts of geospatial data available on the web such as Google Map (GM), OpenStreetMap (OSM), Flickr service, Wikimapia and others. All of these services called open source geospatial data. Geospatial data from different sources often has variable accuracy due to different data collection methods; therefore data accuracy may not meet the user requirement in varying organization. This paper aims to develop a tool to assess the quality of GM data by comparing it with formal data such as spatial data from Mayoralty of Baghdad (MB). This tool developed by Visual Basic language, and validated on two different study areas in Baghdad / Iraq (Al-Karada and Al- Kadhumiyah). The positional accuracy was assessed by adopting National Standard for Spatial Data Accuracy (NSSDA). The evaluation procedure also involved one and two-sample t-test to analyze and compare the accuracy of two study areas. The findings found that the NSSDA accuracy of case study one was 15.48 m, while it was 8.71 m for case study two. This indicated that the accuracy of the GM data is different from site to site. The results also showed that the difference on mean was 6.16 m, which indicated that there is a difference in GM accuracy in different areas. It was concluded that the GM data is inappropriate for engineering applications that require high accuracy, but may be appropriate for applications that need low accuracy such as the primarily surveying of engineering design projects, tourism and reconnaissance….etc.


Article
GNSS Baseline Configuration Based on First Order Design
تشكيل خط اساس الـ GNSS اعتمادا على مسألة التصميم من الرتبة الاولى

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Abstract

The quality of Global Navigation Satellite Systems (GNSS) networks are considerably influenced by the configuration of the observed baselines. Where, this study aims to find an optimal configuration for GNSS baselines in terms of the number and distribution of baselines to improve the quality criteria of the GNSS networks. First order design problem (FOD) was applied in this research to optimize GNSS network baselines configuration, and based on sequential adjustment method to solve its objective functions. FOD for optimum precision (FOD-p) was the proposed model which based on the design criteria of A-optimality and E-optimality. These design criteria were selected as objective functions of precision, which lead to a homogenous and anisotropic network, respectively using Matlab programming language (V. 2012a). Al Ghammas Township, Al-Qadisiya city, which consists of twenty-five stations was taken as a study area in this research. The results showed that there are 300 potential baselines for the GNSS network of the study area, which were reduced during the optimum configuration to about 70% of the total potential baselines by applying FOD-p, and there is high level of improvement in the objective functions of precision which reached to about 90% .


Article
Reinforcement of Asphalt Concrete by Polyester Fibers to Improve Flexural Bending Fatigue Resistance
تعزيز الخرسانة الأسفلتية بالياف البوليستير لتحسين مقاومة الكلل لانحناء الثني

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Abstract

Reinforcing asphalt concrete with polyester fibers considered as an active remedy to alleviate the harmful impact of fatigue deterioration. This study covers the investigation of utilizing two shapes of fibers size, 6.35 mm by 3.00 mm and 12.70 mm by 3.00 mm with mutual concentrations equal to 0.25 %, 0.50 % and 0.75 % by weight of mixture. Composition of asphalt mixture consists of different optimum (40-50) asphalt cement content, 12.50 mm nominal aggregate maximum size with limestone dust as a filler. Following the traditional asphalt cement and aggregate tests, three essential test were carried out on mixtures, namely: Marshall test (105 cylindrical specimens), indirect tensile strength test (21 cylindrical specimens) and flexural bending test (21 beam specimens). The results revealed that, more asphalt content needed as the fibers length and concentration increased. The fatigue life estimation depending on cyclic load to failure in the beam test support the idea that polyester fibers really improve the resistance of fatigue cracking since the repetitions to failure increased by 9.40 % for the 0.50 % of 12.70 mm fibers length. Both of Marshall stability and indirect tensile strength suffer from slight reduction in their values, whereas, the 0.75 % of 12.70 mm fibers length caused lowering in Marshall stability and indirect tensile strength by 11.70 % and 6.00 % respectively.

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