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: 2014 volume:20 issue:8

Article
The Effective Width in Composite Steel Concrete Beams at Ultimate Loads
العرض الفعال في العتبات المركبة من الفولاذ والخرسانة عند الحمل الاقصى

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Abstract

A composite section is made up of a concrete slab attached to a steel beam by means of shear connectors. Under positive and negative bending moment, part of the slab will act as a flange of the beam, resisting the longitudinal compression or tension force. When the spacing between girders becomes large, it is evident that the simple beam theory does not strictly apply because the longitudinal stress in the flange will vary with distance from the girder web, the flange being more highly stressed over the web than in the extremities. This phenomenon is termed "shear lag". In this paper, a nonlinear three-dimensional finite element analysis is employed to evaluate and determine the actual effective slab width of the composite steel-concrete beams by using the Analysis System computer program (ANSYS 11.0). The of elements were used (SOLID65, LINK8, SHELL143, COMBIN39, TARGE170 and CONTA174) to model the concrete slab, the steel reinforcing bars, the steel girder, the shear connectors (including uplift and dowel action), and the interface between top flange of the steel girder and concrete slab, respectively. Comparisons with experimental tests have been performed to validate the finite element analysis results. In general, excellent agreement between the finite element solution and the experimental results has been obtained. The maximum difference in ultimate load is about (2.9%). Finally, parametric studies have been carried out to investigate the effect of some important parameters; these parameters include the degree of interaction, slab thickness, slab width, concrete compressive strength ( ), distribution of shear connectors, reinforcement of slab, type of loading, and boundary conditions. The effect of changing these parameters causes variety in the effective slab width and the maximum stress reaches 40.7% and 28.5%, respectively.


Article
Development a Proposed System of Organization Structure to Management Multi Construction Projects
تطوير نظام مقترح للهيكل التنظيمي لإدارة مشاريع إنشائية متعددة

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Abstract

The purpose of this study is aimed to lay down an arranged platform suited to Iraqi constructional associations which in charge to carry out multi constructional projects, as it fulfilled management requirements and supervising, so that low - cost projects will be controlled in due term and quality. Based on primary info and observed data collected, the study thesis has been formulated in this way: Iraqi constructional sector bodies which are in charge to implement simultaneously multi constructional projects in need to reformulate its organized structure so that it will be more fitted to management and control of these projects. This thesis includes a theoretical part contained presenting the most important resources locally and internationally where it has direct relation with this study subject. Also it touches on the arrangement term and the kinds of organized structure of the multi constructional projects and control it. And its field part included in its first section studying the organized structure and functional arrangement practised in one of the Iraqi constructional projects. in charge of implemented simultaneously multi construction and exposing the defection of this arrangement. The second section of this study included reviewing the organized structure used by some of constructed corporations and foreign companies of implementing multi constructional projects .Thus, the deficiency points of the organized structure and the arrangement followed in Iraqi conduction sectors recognized and what it causes of control defections in the limitation of these projects. The deficiency points have been solved by developing a proposed system of the organized structure to administering and controlling of the multi constructional projects. The implementation of these projects have been controlled from its draw phase and passing the design phase and reference and implementation phase till the first deliver.


Article
PAPR Reduction of OFDM Signals Using Clipping and Coding
تخفيفض قيمة PAPR لاشارات OFDM باستعمال القطع والترميز

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Abstract

The problem of the high peak to average ratio (PAPR) in OFDM signals is investigated with a brief presentation of the various methods used to reduce the PAPR with special attention to the clipping method. An alternative approach of clipping is presented, where the clipping is performed right after the IFFT stage unlike the conventional clipping that is performed in the power amplifier stage, which causes undesirable out of signal band spectral growth. In the proposed method, there is clipping of samples not clipping of wave, therefore, the spectral distortion is avoided. Coding is required to correct the errors introduced by the clipping and the overall system is tested for two types of modulations, the QPSK as a constant amplitude modulation and 16QAM as a varying amplitude modulation.


Article
Effect of high and low density polyethylene on some mechanical properties of concrete
تأثير البولي ايثيلين ذو الكثافة المرتفعة و المنخفضة على بعض الخواص الميكانيكية للخرسانة

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Abstract

The increasing use of plastics in various aspects of modern life resulted in the availability of enormous amount of wastes, including a negative effect on the environment and humans. So it is necessary to find solutions to deal with these wastes and ensure to use them as solutions to use in concrete mix . In this research the production of concrete containing high and low density polyethylene has been used by (5, 10, 15)% as a replacement of part of the volume of sand, so as to obtain concrete good compressive strength as well as other benefits such as improved possibility of pumping concrete and reduce the loss of concrete for workability polymer is a material that is non-absorbable of water . It is also intended to dispose of these wastes positively to achieve benefits to the environment and humans alike .


Article
Scheduling of Leaching Requirements to Prevent the Secondary Salinisation in the Root Zone
جدولة متطلبات الغسيل الإضافية لمنع التملح الثانوي في منطقة الجذور

Authors: Amer H. Al-haddad --- Kolood A. Hussien
Pages: 35-51
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Abstract

Leaching scheduling techniques are one of the suggested solutions for water scarcity problems .The aim of the study is to show the possibility of using leaching scheduling, when applying the irrigation scheduling program for a certain irrigation project, which was prepare by Water Resources Engineering –University of Baghdad with some modifications to generalized it and it make applicable to various climatic zone and different soil types. The objectives of this research is to build a system that concerns the prediction of the leaching scheduling (depth and date of leaching water), illustrating the main problems (soil salinity, save the amount of leaching requirement, and to maintain crops growth).The other objective is to compare between the calculated amount of leaching water with the amount of water that is suggested by designers. The program includes, the calculating of predicted daily soil salinity ,the depth of leaching water that should be applied to remove the salt from the soil when it reaches a harmful level, and the total annual volume of leaching water. The results showed, that the use of predicted leaching scheduling with its applicable constrains require high attention when choosing the cropping pattern for each climate zone. Also, it was found that the leaching program is a useful tool for saving irrigation water if cropping pattern has been adapted carefully. This means the leaching water depth should be added only when needed, and may not be necessary with each irrigation event.


Article
Parametric Study of Active Solar Heating Using a Pebble Bed as a Thermal Collector and Storage Unit
دراسة استدلالية للطاقة الشمسية الفعالة باستخدام فرشة الحصاة كوحدة جمع وخزن للحرارة

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Abstract

In this study, pebble bed as an absorber and storage material was placed in a south facing, flat plate air-type solar collector at fixed tilt angle of (45°). The effect of this material and different parameters on collector efficiency has been investigated experimentally and theoretically. Two operation modes were employed to study the performance of the solar air heater. An integrated mode of continuous operation of the system during the period of (11:00 am – 3:00 pm) and non-integrated mode in which the system stored the solar energy through the day then used the stored energy during the period of (3:00 pm – 8:00 pm). The results of parametric study in case of continuous operating showed that the maximum average temperature difference of air between inlet and outlet sections observed on (0.018 kg/s) air mass flow rate were exceeded (17°C) and the maximum outlet temperature that got was exceeded (34°C) for the three months (December, January and February) of experiments. Average efficiency was ranged from 53% to 65%. In the case of storage and then operating, the maximum outlet air temperature was ranged from (27°C) up to (31°C) then decreased with spend of energy to reach (13°C) to (18°C) and the maximum storage energy was (165.14 W) for the porosity of (0.29) , height of (20 cm) and (0.01 kg/s) mass flow rate. The results also, showed that the solar air collector supplied a solar heating fraction (SHF) with an average of (0.65) for a meeting room (3 * 4 * 7 m) located in Baghdad as a case study.


Article
Buckling Analysis of Stiffened and Unstiffened Laminated Composite Plates
تحليل الصفائح المركبة المقواة والغير مقواة تحت تأثير حمل الانبعاج

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Abstract

The present study focused mainly on the analysis of stiffened and unstiffened composite laminated plates subjected to buckling load. Analytical, numerical and experimental analysis for different cases has been considered. The experimental investigation is to manufacture the laminates and to find mechanical properties of glass-polyester such as longitudinal, transverse young modulus, shear modulus. The compressive test was carried to find the critical buckling load of plate. The design parameters of the laminates such as aspect ratio, thickness ratio, boundary conditions and number of stiffeners were investigated using high order shear deformation theory (HOST) and Finite element coded by ANSYS .The main conclusion was the buckling load could increase and decrease depending on the boundary conditions, thickness ratio, and, the aspect ratio and number of stiffeners of the plate.


Article
Numerical Simulation of The Influence of Geometric Parameter on The Flow Behavior in a Solar Chimney Power Plant system
نمذجة رقمية لتاثير المعاملات الهندسية على سلوك الجريان في منظومة مدخنة شمسية لتوليد القدرة

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Abstract

Numerical simulations have been carried out on the solar chimney power plant systems. This paper gives the flow field analysis for a solar chimney power generation project located in Baghdad. The continuity, Naver-stockes, energy and radiation transfer equations have been solved and carried out by Fluent software. The governing equations are solved for incompressible, 3-D, steady state, turbulent is approximated by a standard model with Boussiuesq approximation to study and evaluate the performance of solar chimney power plant in Baghdad city of Iraq. The different geometric parameters of project are assumed such as collector diameter and chimney height at different working conditions of solar radiation intensity (300,450,600,750 and 900 W/m2) to gain the optimal designed structure. The results show that the change of collector diameter and chimney height has considerable effects on the performance of the system. The velocity increase when the collector diameter and chimney height increase and reach to the maximize value at H=D 12 m and when solar intensity (900 W/m2). The study shows that Iraqi weather are suitable for this system.


Article
Bioremediation of Soil Contaminated with 2,4-D Herbicide Using Bioslurry Reactor
المعالجة البيولوجية للتربة الملوثة بمبيد الاعشاب -D2,4 باستخدام المفاعل البيولوجي

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Ex-situ bioremediation of 2,4-D herbicide-contaminated soil was studied using a slurry bioreactor operate at aerobic conditions. The performance of the slurry bioreactor was tested for three types of soil (sand, sandy loam and clay) contaminated with different concentration of 2,4-D, 200,300and500mg/kg soil. Sewage sludge was used as an inexpensive source of microorganisms which is available in large quantities in wastewater treatment plants. The results show that all biodegradation experiments demonstrated a significant decreases in 2,4-D concentration in the tested soils. The degradation efficiency in the slurry bioreactor decreases as the initial concentration of 2,4-D in the soils increases.A 100 % removal was achieved at initial concentration of 200mg 2,4-D/kg of sandy soil after 12 days and 92 % at 500mg 2,4-D/kg sandy soil after 14 days.Clay soil represented minimum removal efficiency among the three soils, 82 % at initial concentration of 200mg 2,4-D/kg clay soil after 12 days and 72 % for 500mg 2,4-D/kg clay soil after 14 days. Abiotic conditions were performed to investigate the desorption efficiency of the contaminant from soil to liquid phase through the three soils. In abiotic reactor the results showed that the rate of desorption for sand and sandy loam soils were nearly the same, it varied between0.102-0.135 day-1 at different initial concentration of 2,4-D. While for clay soil the desorption rate varied between 0.042- 0.031 day-1 at different initial concentration of 2,4-D. The decrease in desorption rate in clay soil refers to the characteristic of clay soil, (fine texture, high organic matter and high cation exchange capacity compared with the other soils) that may retain the 2,4-D in the organic matter and the clay minerals.


Article
Two-Phase Partitioning Bioreactor for the Treatment of Crude Oil-Contaminated Aqueous Solution
المفاعل البيولوجي ثنائي الطور لمعالجة المياه الملوثة بالنفط الخام

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Abstract

A new application of a combined solvent extraction and two-phase biodegradation processes using two-liquid phase partitioning bioreactor (TLPPB) technique was proposed and developed to enhance the cleanup of high concentration of crude oil from aqueous phase using acclimated mixed culture in an anaerobic environment. Silicone oil was used as the organic extractive phase for being a water-immiscible, biocompatible and non-biodegradable. Acclimation, cell growth of mixed cultures, and biodegradation of crude oil in aqueous samples were experimentally studied at 30±2ºC. Anaerobic biodegradation of crude oil was examined at four different initial concentrations of crude oil including 500, 1000, 2000, and 5000 mg/L. Complete removal of crude oil was achieved biphasic bioreactor after 3 weeks compared to 73-82% in the monophasic bioreactor for the same time period.


Article
New Approach in Detection MAC Spoofing in a WiFi LAN
طريقة جديدة في اكتشاف تزوير المتحكم بالوصول للوسط في شبكة الواي فاي المحلية

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Abstract

Medium Access Control (MAC) spoofing attacks relate to an attacker altering the manufacturer assigned MAC address to any other value. MAC spoofing attacks in Wireless Fidelity (WiFi) network are simple because of the ease of access to the tools of the MAC fraud on the Internet like MAC Makeup, and in addition to that the MAC address can be changed manually without software. MAC spoofing attacks are considered one of the most intensive attacks in the WiFi network; as result for that, many MAC spoofing detection systems were built, each of which comes with its strength and weak points. This paper logically identifies and recognizes the weak points and masquerading paths that penetrate the up-to-date existing detection systems. Then the most effective features of the existing detection systems are extracted, modified and combined together to develop more powerful detection system called Sequence Number with Rate and Signal Strength detection method (SN-R-SS). SN-R-SS consists from three phases. First phase is Window Sequence Numbers; to detect suspicious spoofed frames in the network. Second phase is Transmission Rate Analysis; to reduce the amount of the suspicious spoofed frames that are generated from the first phase. Finally, the third phase is Received Signal Strength; this phase is decisive phase because it decides whether the suspicious spoofed frames are spoofed or not. Commview for WiFi network monitor and analyzer is used to capturing frames from the radio channals. Matlab software has been used to implement various computational and mathematical relations in SN-R-SS. This detection method does not work in a real time because it needs a lot of computation.


Article
Batch and Fixed-Bed Modeling of Adsorption Reactive Remazol Yellow Dye onto Granular Activated Carbon
النمذجة الرياضية لامتزاز الصبغة الصفراء الفعالة باستخدام الفحم المنشط في تجارب الوجبة و تجارب الحشوة الثابتة

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Abstract

In this work, the adsorption of reactive yellow dye (Remazol yellow FG dye) by granular activated carbon (GAC) was investigated using batch and continuous process. The batch process involved determination the equilibrium isotherm curve either favorable or unfavorable by estimation relation between adsorption capacity and concentration of dye at different dosage of activated carbon. The results were fitted with equilibrium isotherm models Langmuir and Freundlich models with R2value (>0.97). Batch Kinetic study showed good fitting with pseudo second order model with R2 (0.987) at contact time 5 h. which provesthat the adsorption is chemisorptions nature. Continuous study was done by fixed bed column where breakthrough time was increased at flow rates (21.67, 12.5 and 6 ml/min) and initial dye concentration (80, 40, 20 and 10 mg/l) were decreased and bed depth was increased (5, 10, 15 and 20 cm). The adsorption data were fitted to the fixed-bed adsorption mathematical models Thomas and Yoon-Nelson models. The results fitted well to the Thomas and Yoon-Nelson models with correlation coefficient, R2≥ 0.944. Average relative error ARE% was applied to examine the theoretical and experimental results.


Article
Corrosion Study of the Injection Equipments in Water in Al-Ahdeb Wells ‐Iraq

Authors: Hassan Abdulkadhim Alwan Alsaadi
Pages: 177-190
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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.

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