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: 2010 volume:16 issue:4

Article
Technology and Architecture Analyzing Architecture from a Technological Standpoint
التكنولوجيا والعمارة تحليل النتاج المعماري من وجهة تكنولوجية

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Abstract

This research is concerned with defining specific analytical terms that could be used in observing the architectural product from a technological view point. This was achieved by founding an inclusive analytical structure for architectural technology based on the view of technology philosopher Carl Mitcham, who states that technology, at a given time and place, could be observed through its four manifestations: Objects, Process, Knowledge and Volition. The research has showed that these manifestations define architectural technology as the actual context within which relations between components of these manifestations emerge, get organized and change. Five analytical terms have been induced: materials and their processing, structure and its relations, detail building, tectonic values and formal expression. These are introduced as terms affecting the formulation of architectural product, and thus can be used for analyzing it technologically.


Article
استخدام كسر الطابوق الطيني المعاد كبديل عن الحصى في انتاج بلوك نمطي اقتصادي

Authors: سلام سمعان عبدالاحد
Pages: 952-974
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During the last 5 decades , it is evident that there is a drastic need for close cooperation between the Iraqi architect and other engineers, technicians working with him , towards solving particular problems related to materials , system building technology in Iraq .The architect need to become a leader of the building team instead of becoming“a Hero”. The research develop a light weight modular block (25x25x12.5cm), equivalent in volume to 3 bricks (25x12.5x7.5 cm).The proposed modular block use broken or crushed bricks as an aggregate instead of stone. The block can be handled easily, it can be produced mechanically i.e. via compressors or manually. The research cover the use of recycled “broken or crushed” bricks by making samples , record photos and statistics .The samples uses 40-65% of the volume recycled bricks .The insulating factor increased up to 70 -80% while cost decreased by approximately half. The paper is one of many applied research topics needed to be tackled on recycling, sustainability and environment improvement in Iraq


Article
Experimental study of plate heat exchanger air cooler
دراسة تجريبية لمبادل حراري صفائحي كمبرد هواء

Authors: احمد أديب عبد الواحد
Pages: 975- 988
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Abstract

As cooling air using water injection was limited by a range of humidity ratio so indirect humidification for air consider , this research take the study of heat transfer through a perpendicular plate heat exchanger to discover the influence optimum conditions on dehumidification efficiency and the amount of heat transfer energy across the plates of heat exchanger so calculating dehumidification efficiency and the amount of heat transfer energy across the plates of heat exchanger depending on the change of primary and secondary air flow rate using an experimental apparatus with an instruments for measuring air flow rate , dry bulb temperature and wet bulb temperature on air entry and exit sections , experimental procedure by fixing primary air mass flow rate with changing secondary air mass flow rate once and the condition of entering primary air another time , also fixing secondary air mass flow rate with primary air mass flow rate once and the condition of entering primary air another time . Results show that the increasing of both the dehumidification efficiency and the amount of heat transfer energy across the plates of heat exchanger depend on the increasing of secondary and decreasing of primary air flow rate , percentage of increasing dehumidification efficiency 16 when secondary air mass flow rate increase from 0 to 0.2 kg/s and percentage of increasing heat transfer 35 with above flow rate , percentage of decreasing dehumidification efficiency 12 when primary air mass flow rate increasing percentage 12 and percentage of increasing heat transfer 21 with above flow rate


Article
The Hidden Fields in Material that used for Building
حقول القوة الخـفية في المادة المستعملة في المباني

Authors: أنفال مؤيد الحجيات
Pages: 989-1011
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Abstract

In the Last Recent Years, the Conservation of Natural Environment Resources be a Problem that to and fro to get a line between two elements, First of one is the Natural Environment Resources Balance , and the other is the Reduction of its Consumption and Limitation of Negative Results upon this Environment, Last Years seeks to but Modern Architecture Concept to Conservator Energy Resources and Natural Sources To Reach that Known Sustainable Buildings Which have the Lessees Effect on the Natural Environment and its Environmental Properties. On the Concern that Materials is the Main Component of Architectural Configuration and appearance that Architect use it in Sustainable Construction to redecate the Environmental effect and to establish a complete constructing experience in Architectural Field ,in the same Time it been the Basic stone effected the nature by reducting its recourses continually , and thrown Tons of Wastes in Trash areas on the Roods Edges, Resulted the abuse of Hectares of Agricultural lands . this Dangerous Trashes accumulated without any treatment in most of Countries , that Generate Negative reaction Power upon this Environment ,because of Chemical Interactions of This materials (Trashes)between each and other. Therefore , The study directed in its Problem to Illustrate the Identity and Nature of Projected Power that Causes the accumulation Tons of Materials , and Resulting the action of Change in Material and the Natural of Reaction Generated from Material that Causes Pollution .Research aims to put Sustainable Building (in the point of view of Material that constructs it) in front of nature of Forces that causes Material Change and Changes Through the Running Time of Building age and so….to Have a Wide Lines on Effected Forces of the same Materials that used in Buildings and causes Environmental Pollution , Today used in the Sustainable Buildings but in the Form that Reeducate the Environmental Pollution of it. The Research based on the study of Power's Nature That effected materials and influenced by , and its effects on the Environment system, to be the case study of this study.

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Article
Design Criteria for Historic Fortresses Buildings in Iraq (Case Study Kirkuk Fortress )
المحددات التصميمية لمباني القلاع التاريخية في العراق (دراسة تطبيقية لقلعة كركوك)

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Abstract

Historic fortresses are providing us with an immediate point of contact with old ages, are giving us different images because of different times and places, they are like materialistic messages from past generations to the present with a contemporary protect thought in order to be a motivation for present creative works, which were built to take military, political, social and economic role, to serve a whole variety of purposes this is what makes fortresses as specific architectural units, so the research concentrated on historic fortresses in Iraq and studied its architectural landmarks and design criteria, therefore the problem is appointed by little studies related to fortresses, and how should be developed, the aims of research are: studying of fortresses, their types besides security defensive concepts, finding out characteristic samples of local experiences in dealing with the fortified fortresses. This fact gave the author motivation to lay ground for a practical method and updated study to give Life to the urban and architectural existences in Kirkuk fortress. Fortresses are large fortified buildings or group of buildings usually dominating the surrounding country or a stronghold converted to different uses like cultural, social, residential and tourist activities, or a site of ancient earthworks. There are many classification of fortresses that depend on several factors like: pattern, historical way, time, region, …etc Most of fortresses have defensive fortified factors like: fortified elements, strategic site, physical shape and construction More care and attention should be devoted to such monuments like fortresses, whether single buildings or urban agglomerations because of their present state are a source of environmental pollution rather than focal points of interest and attraction. Iraq is especially wealthy in historic fortresses, a fact that calls for continuous and serious efforts to bring it to its active state, so that it may not remain as neglected and useless. According to the above facts, the research is oriented to historic fortresses in Iraq especially Kirkuk fortress, as it is very rich in its historic and traditional buildings and urban configurations. Although several studies were conducted to bring up the dilapidated state of Kirkuk fortress up to the accepted operational active state of construction, but very little was actually done to bring the plans into action. This reality was one of the main motives to orient this research to this location, especially that the germs of dilapidation are still effecting what remains of its heritage, whether because of war devastation, theft, or neglecting. Although there are few studies related to the reconstruction of Kirkuk fortress it remains as a superficial and outdated to be a real and effective solution to the present state of the fortress. This fact led the author to verbal proposals and suggestive planning ideas for the physical development in Kirkuk fortress. The proposal indicated the division of the fortress into three distinctive areas: Conservation area, Mixed area, and an area of new urban design. The research ended up with a proposal and recommendation to deal with such locations. The research focuses on the "Improvement of Kirkuk fortress based on its design criteria" in dealing with its three proposal distinctive areas: Conservation area, Mixed area, and an area of new urban design.

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Article
السبل التخطيطية والتصميمية لتحقيق مبادىء الاستدامة التقليدية في عمارة الإسكان المحلية المستقبلية

Authors: ميساء ازيارة محمد
Pages: 1034 -1061
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Abstract

Today, the term "sustainability" became one of the most important concepts of interest in scientific and academic debates. The modern approaches in planning and architecture call for respect of the environment and its ecological system through the harmony among three aspects: economical performance ,social responsibility and protection behaviors on environment, which is called “sustainable architecture “.Obviously, this term can be seen in traditional residential dwellings architecture through the interaction with its local environmental conditions .This is what this research deals with by the study and analysis, to determinate the most important principles of traditional house design in terms of climate treatment , building materials choosing and construction methods .In other aspect, the research referred to the existing manners of recent housing architecture .From this analysis and discussion the research explain the wide response of traditional housing to the local environment and exploitation of the natural potentials to the realization of the comfort zone of occupants. Finally, the research tries to indicate the most important planning and design principles to achieve the sustainability in future local housing architecture.

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Article
Removal Of Oil From Wastewater By Organoclay Prepared From Iraqi Bentonite

Authors: Jassim M. Kshash --- Abbas H. Sulaymon
Pages: 5778-5798
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The present study deals with the removal of oil from wastewater by organoclay. The organoclay was prepared by combination of Iraqi bentonite with quaternary amine (hexadecyltrimethyl ammonium chloride). The wastewater samples were obtained from the washing unit of fuel oil in the "South Baghdad Gas Power Plant". The operating conditions of batch process for removal of oil from wastewater by using the prepared organoclays were studied in details (quantity of organoclay, mixer speed and time of adsorption). Initial concentration of wastewater used in this study was within a maximum range of 230-1512 mg/L. XRD and FTIR diagram of the prepared organoclay showed a considerable differences from those for natural bentonite which indicates the exchange of quaternary amine with Ca++ ions at the surface of bentonite. The concentration of oil in the wastewater samples decreased below 10 mg/L after treatment with organoclay. Batch kinetics studies were conducted by using kinetic equations (Lagergren and Ho et al) and batch isotherm studies was conducted by using isotherm models (Freundlich, Langmuir and BET).


Article
Regeneration of Spent Transformer Oil

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The regeneration of spent transformer oil taken from Al-Dora power station was studied. The regeneration process includes settling, filtration, thermo vacuum evaporation, and clay treatment. The settling was done by gravity to remove the mechanical particles. The filtration was done by filter paper [whatman quality1 and 18.5 cm diameter]. Thermo vacuum evaporation at 175˚C and 241 mm Hg was used for removing the dissolved water and light petroleum impurities. The clay treatment was used for final improvement of transformer oil properties. Iraqi clay, Algerian clay and zeolite (A) were used and the results were compared. It was studied the effect of clay to oil ratio and the mixing time on the water content, break down voltage and the acidity. It was considered that the best operation conditions are clay to oil ratio 2/100, and time 5 min. In these conditions the oil has water content 32 ppm, break down voltage 55 kV and acidity 0.028 mg KOH/g oil. It was found that Algerian clay gives better improvement than zeolite and Iraqi clay using the same operating conditions. Langmuir, Freundlich, and the combination of them adsorption isotherms were studied in this investigation and It was found that Freundlich adsorption isotherm well represented the adsorption of water on clay comparing with others isotherms.


Article
Removal of lead from simulated wastewater by electrocoagulation method

Authors: Muhanned Dhia Fadhil Al-Mureeb --- Ahmed A.Mohammed
Pages: 5811 -5821
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Abstract

The separation of lead ions from wastewater was carried out in an electrocoagulation cell which has a set of electrodes, aluminum anode and stainless steel cathode. The effect of several working parameters such as pH, current density, initial lead concentration, electrodes surface area, gap between electrodes and sodium chloride concentration on the performance of electrocoagulation cell were examined. From the experiments found that the higher removal efficiency achieved at pH 9, with increasing current density and decreasing gap between electrodes the removal efficiency enhanced and the treatment time decreased. Using a flowrate of 0.025 l/min after (7min) electrolysis, the Pb(II) concentration decay from (250mg/l) to only (2.5mg/l) corresponding to a 99% removal efficiency.


Article
Construction Water Suitability Maps Of Tigris River For Irrigation And Drinking Use

Authors: Wardah Sabah Kamil --- Khalid Adel Abdulrazzaq
Pages: 5822 -5841
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The Tigris River is one of two major sources of surface water in Iraq, with 1900 km length, 1415 km of which are in Iraq. Increasing demands of the river water for beneficial uses lead to increase the concern about its quality. World Health Organization (WHO, 2004) and Iraqi Quality Standards (IQS, 2001) have been adopted along the river to compare and examine the degree of permissibility of polluted parameters T.H, SO4-2, Cl-1, and T.D.S for drinking use, whereas American Salt Laboratory Standards has been adopted basing on SAR and EC for irrigation use. Different international methods have been applied to classify the water quality index for the Tigris River at north of Baghdad station which are Brown (1970), Mecllelend (1974), and Bhargava (1983). A general program was constructed to estimate the surface water quality variation with time and location for drinking and irrigation adopting Bahrgava,1983 method, since it is more effective in dealing with many sensitive functions related to the pollutant parameters through the analysis of T.H, SO4-2, Cl-1, T.D.S, EC, Ca+2, SAR, pH, and BOD which are the relative parameters to the previous mentioned beneficial uses. The program use Visual Basic Studio, 2008 language as a tool because it is easy to operate automatically by engineers or the decision makers for the water quality assessment. Thirteen stations along Tigris River were taken in the analysis, starting at Feeshkabour and ending at Al-Qurna. The historical recorded data which were used had been selected through 2007/2008 as a monthly base. In general, the results showed that the Tigris River is class I to II for irrigation use, while its class ranges from II –V for drinking use. According to these classes, the Tigris River is divided into two reaches as follows: • From Feeshkhabour to Tarmiyah, the water quality index (WQI) is classified as class I for irrigation, and class II for drinking use. • From North of Baghdad till Qurna, WQI is classified as class II for irrigation, and class IV for drinking use. The results also indicate that there is an increase in T.H values leading to deterioration in water quality for drinking use; also, an increase in SO4-2 parameter after Tarmiyah, and Cl-1 parameter after Kut that affects the suitability of water for irrigation use. Finally, different suitability maps are constructed to classify water of 2007/2008 for irrigation and drinking use, which will be a base to trace the type of pollutants and their weight that cause the deterioration of the previously mentioned uses.

Keywords

WQI --- Drinking Water --- Irrigation


Article
Multi-Basis Wavenet-Based Speed Estimation in Direct Torque Controlled Asynchronous Motor
تقدير السرعة في نظام التحكم المباشر لعزم المحرك الغير متزامن باعتماد الشبكات العصبية المويجية متعددة الأساسات

Authors: Adel A. OBED
Pages: 5842 -5854
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Abstract

This paper presents a proposed method for speed estimation of asynchronous motor in Direct Torque Control (DTC) system, based on a new architecture of multi-basis wavenet model. Such multi-basis model utilizes multi-set daughter wavelets. Firstly, the structure and training algorithm of the proposed method is discussed. The descent gradient method is used to fulfill both system structure and parameters initialization. Secondly, the proposed speed estimator and the DTC asynchronous motor are combined based on stator current signal and the motor speed is then estimated online with the operation of the system. Finally, the effectiveness of this method is proved by simulation carried out using Matlab/Simulink library and compared with the actual results obtained from the dynamic equations of the motor. The simulation results are obtained over the entire speed of starting, load conditions and motor braking. These results show that the proposed method is effective for speed estimation in DTC drives.


Article
Hand Written Recognition Using Neural Network Algorithm

Authors: Ammar O. Hoori
Pages: 5855- 5862
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Hand written recognition problem can be done in two major steps, first by separating each character alone and second by detecting the separated shape to its corresponding like alphabetic letter. A backpropagation neural network found to be a good artificial intelligence algorithm in facing character recognition problem. In this work, backpropagation neural network is used with 3-layers to detect and separate 26 English letter from (A to Z). In addition, a previous steps should be taken to detect the boundaries of each single written letter. Detecting a complete text can be done by separating each character through finding its boundaries, resizing the separated character to be suitable for pre-trained neural network, detecting the hand-written letter and finally saving the guessed letter to a text file. This work is developed using Matlab 2008 version 7.6. The obtained results show good representations of letter contaminated by noise and non-trained letters.


Article
Statistical Estimation Of The Compressibity Of Baghdad Cohesive Soil
تقييم احصائي لانضغاطية تربة بغداد المتماسكة

Authors: Abbas Jawad Al-Taie --- Bushra S. Al-Busoda
Pages: 5863-5876
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Because of the time and expense involved in performing consolidation tests, it is often desirable to obtain approximate values of (Cc and Cr) by using other soil properties which are more easily determined. The literature contains numerous equations linking soil compressibility to its physical and index properties. As these equations are often used to obtain preliminary evaluations of (Cc) and (Cr), it is important to know the reliability of these equations. In this paper an attempt was made to estimate (Cc and Cr) of Baghdad cohesive soil from other soil properties. A number of commonly used empirical correlation equations that have been developed during the last six decades to estimate (Cc and Cr) were compiled and evaluated. The results of routine laboratory tests of a large number of databases of Baghdad soil were correlated with more sophisticated laboratory consolidation results by conducting simple and multiple regression analyses. It was concluded that the compression index of Baghdad cohesive soil cannot be estimated from Atterberg limits and the better values of compression and recompression indices of Baghdad soil can be obtained when more than one index property is used in the regression analysis.


Article
ECG Slantlet Transform With FPGA Design

Authors: Zainab N. Ghanim
Pages: 5877- 5891
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The ECG is used for the clinical analysis of physiological data has occurred in the field of cardiology. Certain abnormalities of the ECG are quite well defined and can be readily identified. The digital signal processing Slantlet Transform is used in the feature extraction of ECG monitoring and Diagnosis system to convert the continuous ECG signal to a form can be classified by a classifier of the ECG monitoring and Diagnosis system to detect the cardiac abnormalities. In this paper, FPGA is used to build the slantlet Transform of the ECG feature extraction .VHDL program of FPGA is used in the work, the obtained output results are similar to the past work results, which is built by using Mat Lab program, in accuracy and closing to the original ECG signal. Using FPGA decreases the cost and time for building hardware system of ECG Monitoring and Diagnosis system. It also gives more flexibility than the alternate approaches. Mat-Lab program is used only for displaying the input and output discrete signals of slantlet transform.

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Article
The Influence Of Tension Stiffnening Models On The Dynamic Analysis Of Reinforced Concrete Slabs

Authors: M.K. Kasim --- A.A. Abdul-Razzak --- K.S. Mahmood
Pages: 5892 -5910
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In the present work, the finite element method has been used to investigate the behavior of reinforced concrete slabs subjected to dynamic loads. Eight-node Serendipity degenerated elements have been employed. This element is based on isoperimetric principles with modifications, which relax excessive constraints. The modifications include reduced order integration to overcome the shear locking. A layered approach is adopted to discretize the concrete through the thickness. Both an elastic-perfectly plastic and strain hardening plasticity approaches have been employed to model the compressive behavior of the concrete. A tensile strength criterion is used to initiation of crack and a smeared fixed crack approach is used to model the behavior of the cracked concrete. Five models are used to consider the effect of tension stiffening in the cracked concrete. Implicit Newmark with corrector-predictor algorithm is employed for time integration of the equation of motion. Several examples are analyzed using the proposed model. The numerical results showed good agreement with other sources.


Article
The Transition To A PG Grading System For Asphalt Cement In Iraq

Authors: Alaa S. Abbas --- Amjad H. Albayati --- Hamed M. H. Alani
Pages: 5911-5931
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In Iraq, as well as many other developing countries the performance graded (PG) based System is not yet implemented to evaluate the currently used asphalt cements for paving works. It appears that not only the unavailability of test equipments is resulting in this delay but also the lack of clear understanding of what steps could be taken to incorporate this system. This research is an attempt to highlight the important aspects of a (PG) system that can be readily implemented without the need for expensive equipments. It includes the development of a Performance based System employing the conventional test methods and available nomographs from literature. It also, shows how climatic data, traffic data, and asphalt binder properties can be combined to propose a possible major improvement for the specifications of asphalts in Iraq. To achieve the objective of this research, an extensive air temperature data for a period of 18 years was reviewed for five cities (Mosul, Kirkuk, Rutba, Baghdad, and Basrah) to establish the required PG asphalt binder for each city. Also, the currently used asphalt cements with penetration grades (40-50) and (60-70) were tested by both of conventional test methods and Superpave methods to determine the equivalent performance grade for each type of the penetration graded asphalt and to evaluate the capability for these two types of asphalt cement to satisfy the required performance of pavement for each city. The results indicate that both the new proposed method and Superpave method give the same final performance grade, The asphalt with penetration grade 40-50 is equivalent to PG70-16 while that with penetration grade 60-70 is equivalent to PG64-16.


Article
Coloring Of Gray-Scale Image Using FPGA

Authors: Ammar A. Hassan
Pages: 5932-5945
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The image processing is one from the most powerful fields in the modern DSP techniques; also it has wide range of applications this day such as image compression, filtering and coloring. However, these processes required to a huge data processing so it has a problem under real time or movie. The huge data processing under real time requires spatial processing tools such as super parallel processing computers or spatial hardware systems. This paper introduces a mechanism of coloring gray scale image algorithm through dedicated hardware devices. The FPGA devices are used as a more suitable platform for image processing applications, special methods of parallelism and pipelining technique can be reconfigured and synthesized on FPGA categories. Xilinx series are selected as a platform of coloring algorithm by transferring the color property between pair image, source (colored) and target (gray) images. The algorithm colorizes each gray scaled pixel by matching chromatic value of it with each pixel of colored image and synthesis it on the Xilinx FPGA devices using VHDL synthesizer tool. Many computational and process manners of this scheme are presented of 8-bit precision for each pixel of pair image. Finally, testing and performance of this technique obtained on ISE 4.1i software implementation and comparing results with other simulator results.

Keywords

coloring --- Gray-scale --- DSP --- VHDL --- Xilinx --- FPGA.


Article
Correlations between Physical and Mechanical Properties of Al-Ammarah Soil in Messan Governorate

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This paper describes the geotechnical properties of Al-Ammarah soil of Ammarah city in Messan Governorate-southern parts of Iraq. Data and other information taken from numbers of geotechnical reports that performed under the supervision of Consulting Engineering Bureau of Baghdad University. This research is devoted to study the correlation between different physical properties such as (LL, PI, LI, ωn,γt, e0) with different mechanical properties such as (qu, cc, cs, SPT). The correlation is verified using simple regression analysis. From the regression results it was found that there is direct correlation between different parameters. By using the correlation-with some information- preliminary investigation stages and studies of any structure can be performed to find indicative design parameters.


Article
Developing A Methodology To Prepare Design According To Production Requirement

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This paper aims to develop a program based on a methodology to enable the preparation of design according to production requirement. Thus, the appropriate algorithms were developed to evaluate the product design according to assembly requirements and also to assess the product design according to manufacturing requirements. The programs were applied to four case studies, two of them for Design for Assembly (DFA) and other two were for Design for Manufacturing (DFM). The study concluded that the method gives very good results for (DFA) and results of the studied two cases showed to lower the total assembly time, as well as increases the quality of the operation by lowering the probability of error expectation. However, results of (DFM) studies cases showed that the proposed program needs more development to cover all factors affecting the manufacturing processes. The paper concluded that the suggested and developed DFA and DFM programs are a valid and beneficial approach; however, more research work is required to establish a complete and comprehensive database to match the experience of human experts in the field. Adding such database to the developed programs will increase its reliability and applicability.


Article
On The Dynamics Of Dual-Spin Spacecraft Containing A Nutation Damper

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The dynamics of dual-spin spacecraft which containing a proposed nutation damper which consisting of a ring totally filled with a viscous liquid with offset center, to improve damping, is investigated. The equations of motion were developed using Newton-Lagrange approach resulting equations in terms of spacecraft’s and damper’s parameters , which are given in dimensionless form. The expression of the nutation angle and time constant in both modes are developed using zero-order approximation technique. The equilibria states and stability condition, and the analytical expression for residual nutation angle were derived. The analytical results were compared with those found numerically using computer simulation program named MATLAB, ver. 7. Also the effect of various spacecraft’s and damper’s parameters on the dynamic and damping characteristics are discussed. The three dimensional graphical representation of the first and the second relative equilibria states are introduced. The numerical results are compared with the analytical for both modes of motion, where the percentage error of the time constant for nutation mode is less than ( 3.6%), and for spin mode is less than ( 8%). As an important result its concluded that the proposed damper works better than that used by Alfriend(2).

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Article
Behaviour Of Cross - Ply Laminated Hybrid Composite Plates With An Inclined Crack Subjected To A Uniform Temperature Rise

Authors: Majid H. Faidh-Allah
Pages: 6001-6011
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Thermal buckling analysis of symmetric and antisymmetric cross-ply laminated hybrid composite plates with an inclined crack subjected to a uniform temperature rise are presented in this paper. The first order shear deformation theory in conjunction with variational energy method is employed in the mathematical formulation. The eight -node lagrangian finite element technique is used for obtaining the thermal buckling temperatures of hybrid composite laminates. The effect of crack size and lay-up sequences on the thermal buckling temperatures for symmetric and a antisymmetric plates are investigated. the results are shown in graphical form for various boundary conditions. Finally, from this paper, the following main results have been found from which the buckling temperature is affected the larger crack length more than the small crack length, together with other result that the buckling temperature of the plate for every perforation angle is to increase while crack length is increasing.


Article
Woven Factor For The Mechancial Properties Of Woven Composite Materials
معاملات النسج في الخواص الميكانيكي للمواد المركبة النسيجية

Authors: Kadhim H. Ghlaim
Pages: 6012 -6027
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In the past years, the use of composite materials in the aircraft industry, among others, has grown immensely. Composite systems offer an advantage over traditional aircraft materials (metals) because they tend to exhibit higher strength/weight and stiffness/weight ratios than metals, thus making the aircraft lighter and improving performance. Woven composites are increasingly considered for such applications because they offer ease in manufacturing of complicated geometries, but the mechanical properties for different weave patrons of the material is even less well characterized than that of non-woven (angle-ply) laminates. For this reason and because the woven composite mechanical properties is impotent for the theoretical work of the presented work way. The woven factors were evaluated and measured for the composite with different weave patrons, fiber materials and matrix materials. The woven factors were calculated from the measuring mechanical properties from tensile tests of woven composite and for the cross-unidirectional composite made from the same materials. Three types of fiber were used which are E-Glass, Kevlar, and Carbon, while epoxy and polyester were used as a matrixes. The results showing that the woven factors for the Kevlar is higher than the E-Glass and the Carbon and the composites reinforce epoxy have higher woven factors than the composites reinforced polyester.


Article
Pulse Width Modulation For High Performance Hybrid Stepper Motor

Authors: Ali Sabah Mahdi --- Qais S. AL- Sabbagh
Pages: 6028-6047
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This paper presents a high performance vector control approach of the current and speed for Hybrid Stepper Motor (HSM) to improve the dynamic performance of the motor. This is the basic advantage of stepper motors over other types of motors. The open loop controller shows a poor dynamic performance. The stepper motors are widely used in precise motions which is required a high dynamic. However, an open loop control is insufficient, so a closed loop control is required. The field oriented control will improve the dynamic performance of the stepper motor which becomes as a high- dynamic ac- servo. A design and implementation model of HSM using in MATLAB/ Simulink is given. The model is based on nonlinear equivalent circuits representing the operation of the motor. The simulation results of the HSM are compared with practical results of reference design kit (RDK) stepper motor, and a close agreement is noticed.

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Article
Effect of Inner Boundaries Geometry on Natural Convection Heat Transfer in Horizontal Annuli
دراسة تأثير الشكل الهندسي للحدود الداخلية على انتقال الحرارة بالحمل الحر داخل اسطوانتان افقيتان متحدتا المركز

Authors: Faris A. Badawy --- Kadhum A. Jehhef
Pages: 6048 -6063
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Abstract

An analytical modeling of natural convection in physically-based analysis is developed for investigate free convective heat transfer in horizontal eccentric annulus between a circular outer cylinder and heated different shape inner envelope with used four models of the shapes of the inner cross section of (circular, triangular, square and hexagon inner boundary). The main objective of this paper was taking a composite model based on asymptotic solutions for three limiting cases: pure conduction, laminar boundary layer convection and transition flow convection. Laminar conditions up to Rayleigh number RaPi of 5×10^4 were investigated. By using data from MATLAB simulations for a wide range of two cylinder temperature difference in order to study the effects of annulus diameter ratio, Rayleigh number, and the cross section geometries of inner cylinder on the Nusslte number and the ratio of thermal conductivity. The numerical result illustrated for the circular the increasing the Rayleigh number leading to slightly increasing the non-dimensional Nusslte number with various value of annulus diameter ratio and when used the high annulus perimeter ratio (Po/Pi) about (4.5,2.6,1.6 and 1.175). There is rapid increasing in the non-dimensional ratio of thermal conductivity with increasing the Rayleigh number at the high values of (Po/Pi), and the result showed that the non-dimensional ratio of thermal conductivity and the Nusslte number values of the (triangular, square and hexagon) less than in the case of circular inner boundary, but the hexagon model showed the Nusslte number more that than in the (triangular and square). the mathematical results compared with model developed by pervious numerical the model and data are in good agreement, with an average RMS difference of 10.6% for the circular annulus of dimensional Nusselt number (NuPi) and less than 4.9 % and 9.8% for the square inner geometry non-dimensional ratio thermal conductivity.


Article
Estimation Of Radon-222 Concentrations In A Residential Area In Baghdad City

Authors: Ahmed H.Ali --- Baha` ElDin Ma`ro --- Salam J. AlMaliky
Pages: 6064 -6070
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Abstract

Airborne radioactive particulates (for both indoor and outdoor air), in Al-Jaderiya region (Baghdad), have been collected to measure the concentration of Radon-222 daughter products of gamma ray emission (214Pb, 214Bi and 218Po) and hence calculate the concentration of Radon-222. 24 samples were analyzed (12 indoor and others outdoor), using gamma ray spectrometric system based on a High purity Germanium detector (HpGe) of (40%) efficiency. The average concentrations of Radon-222, were found to be (93.7 Bq/m3) and (18.9 Bq/m3), in indoor and outdoor air respectively. The comparison of these concentrations with some internationally typical values has showed that the concentrations of Radon-222 are higher in outdoor air of the area of study compared with many regions in USA and other countries. On the contrary, the concentrations of Radon-222 in indoor air of the area of study are less than those in many European countries.


Article
Surface Temperature Effect On The Thermohydrodynamic Performance Of Journal Bearing In Heavy Duty Machinery

Authors: Basim R. Sadiq --- Ala M. Hosain --- Basim A. Abass
Pages: 6071-6084
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Abstract

Increasing high demands for concept design requires journal bearing to work under several operating condition. The purpose of this work is to study the effect of surface temperature on the performance of journal bearing for heavy duty machines. Steady state thermohydrodynamic model (THD) for journal bearings has been developed. The generalized Reynold's equation, energy equation in the oil film, and the heat transfer equation in the bush and shaft are solved simultaneously. It was found that the shaft temperature has a great effect on the performance of the bearing.


Article
Expermental Investigation Of Temperature For Stir Friction Welding Distribution

Authors: Suhair G. Hussein --- Qasim M. Doos
Pages: 6085 -6099
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Abstract

Friction stir welding (FSW) is a solid state joining method for metal and is widely used for Al-Alloys. In the present work ,temperature distributions were investigated for Aluminum alloy (7008), the effect of the main welding parameters such as rotational speed (tool speed) and liner speed (welding speed) on the temperature distribution were investigated .The results show that the rotational speed has a strong effect on the temperature distribution and this effect increases with temperature increase, but the linear speed has an (inverse proportion) with the temperature increase. This effect was less than the rotational speed. Peak temperature was estimated theoretically by using (Bakingham ) theorem to derivate the relationship between the dimensionless heat input and dimensionless peak temperature. In this study a mechanical test (tensile test) for welded specimen was investigated to study the effect of temperature distribution on the mechanical properties of the alloy, results show that Aluminum alloy (7008) was weldable on the (FSW) process and obtain an maximum weld efficiency (81%) with parameters (880 rpm) rotational speed and (1 mm/sec) welding speed. By comparing test results with peak temperature to the Al-Alloy the obtained result was that the welding process is successful when welding temperature be (75-80%) of melting point of the used material.


Article
Numerical And Experimental Investigation On The Effect Of Restriction Shape On Characteristics Of Airflow In A Square Duct

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Abstract

Experimental and numerical investigation has been under taken to study turbulent flow of air through duct using restriction in different shapes and positions for Reynolds numbers ranges of (8.2x10^4 → 5.6x10^4).The numerical approach used in this work is the finite volume method for solution of elliptic partial differential equation for the modeling of turbulent (k-ε) model as well as wall function concept near the wall which was used to take the turbulent effects into consideration have been employed.The experimental test rigs were constructed from Perspex, and a five-hole pressure probe was used to measure the three component of air flow velocity vector in space.The results show that the total pressure drop depends on the shape and position of the restriction, and the pressure drop coefficient due to the restriction shape and position (kR) depends on two parameters; blockage area ratio (Ab) and the ratio between wetted perimeter to the free remainder perimeter (pe/Pe) and dose not depend on the Reynolds number ( for the same blockage area ratio Ab if the pe/Pe increases 40%, the coefficient kR increases 7% , and for the same pe/Pe, if the blockage area ratio increases 50% ,the coefficient kR increases 10%). But the pressure drop coefficient due to the friction (Cf) is a function of Reynolds.

Keywords


Article
Verification Of Laminate Composite Plate Simulation Under Combined Loadings Thermal Stresses

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Abstract

This study deals with thermal cyclic loading phenomena of plates which were fabricated from composite materials (woven roving fiber glass + polyester) were exposed to (75 °C) temperature gradient thermal shock for ten times in different stage of conditioning times due to the effect of thermal fatigue using the method of Levy solution and compared these results with both results from experimental published work and (ANSYS Ver. 9) program. A composite laminate plate with fiber volume fraction (υf =25.076%) is selected in this study and applying the combined loadings like bending moment (Mo), and in-plane force (Nxx) beside the effect of thermal fatigue. It involves multi theoretical and finite element fields; but the theoretical one contains the derived equation of stresses distribution and evaluating the normal deflection of a middle point for dynamic analysis applying different boundary conditions for heating and cooling. The main present numerical results for a composite plate with (80%) fiber volume fraction claim that the relative reduction in normal deflection and dynamic load factor are (78.593%) and (9.421%) during cooling to (-15 °C) respectively.


Article
Numerical And Experimental Investigation Of Steam Film Condensation On A Vertical Tube

Authors: Luma F. Ali --- Wail S. Sarsam
Pages: 6143 -6163
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Abstract

Film condensation of steam on a vertical tube is investigated numerically and experimentally, in the present work. A mathematical model was set based on the basic conservation laws of mass and energy, Nusselts analysis of film condensation, and empirical equations available in the literature. Then, a simulation program in FORTRAN language was developed which simulates the film condensation of steam on a vertical tube. A complete steam tables subprogram was also developed and incorporated with the main program. The experimental work was carried out using a steam condensation test bench. The inlet and outlet cooling water temperatures, steam temperature and pressure, tube surface temperature at center, and cooling water flow rate are recorded during each experimental test run. The inlet cooling water temperature, steam temperature, and cooling water flow rate are used as an input for the numerical program, then the program calculates tube surface temperature distribution, cooling water temperature distribution, local heat transfer rate, local condensation heat transfer coefficient, condensate boundary layer thickness distribution, total heat transfer rate, and average condensation heat transfer coefficient. The effect of various parameters on the condensation heat transfer coefficient, such as steam temperature, steam-surface temperature difference, and the presence of non-condensable gas were investigated and reported graphically. It was found that increasing (steam-surface) temperature difference while keeping the steam temperature constant results in an increase in condensate boundary layer thickness, which in turn causes a decrease in condensation heat transfer coefficient. On the other hand, increasing steam temperature and keeping the (steam-surface) temperature difference constant leads to an increase in condensation heat transfer coefficient. In addition, the presence of non-condensable gas with different concentrations was also investigated and it was shown that it causes a noticeable reduction in the average condensation heat transfer coefficient. An equation for calculating average condensation heat transfer coefficient on a vertical tube was also developed. The experimental data obtained from the test runs were compared with numerical results and showed good agreement. Thus, it can be concluded that the present computational program is suitable for simulating steam condensation on a vertical tube.


Article
Parametric Study Of Suction Or Blowing Effects On Turbulent Flow Over A Flat Plate

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Abstract

The two-dimensional, incompressible, and turbulent boundary layer flow over a flat plate with suction or blowing from a spanwise slot is examined numerically. The mathematical modeling involves the derivation of the governing partial differential equations of the problems. These are the continuity, the momentum, the energy and the (K-ε) turbulence model. Besides, the perfect gas law is also used. A numerical solution of the governing equations is approximated by using a finite volume method, with staggered grid and modified SIMPLE algorithm. A computer program in FORTRAN 90 is built to perform the numerical solution.The developed computational algorithm is tested for the flow over a flat plate (4m) long with uniform suction or blowing velocity ratios of (V/U∞ =± 0.0185, ± 0.0463 and ±0.0925 m/s) are imposed on the slot for Reynolds number of (1.36 x 10^7 ), based on the plate length. The position of the slot change in the range of (X/L=1/4, 1/2 and 3/4) from leading edge and also, change width of slot in the value equal (0.12, 0.2 and 0.28m).The plate temperature is (70 °C), with the free stream velocity and temperature are (8.6m/s) and (25 °C) respectively. In addition, the effects of pitch angles on the flow field are investigated in the range of (30о<=α<=150о).The numerical results show that, for a uniform blowing, location of slot equal (X/L=1/4) from leading edge, a significant reduction of skin friction coefficient, wall shear stress and boundary layer thickness [displacement and momentum] to occur. While, an increase in boundary layer shape factor. Reynolds stress (uv) is more decreased than [(uu) and (vv)], mean velocity profiles in wall coordinates and dimensionless distance (U+, y+) decreases. When slot location is moved downstream to locations (X/L=1/2 or 3/4) a similar behavior can be said and most effective slot is obtained as (slot at X/L= 3m) from leading edge. While width of slot equal (0.28m) is better than values equal (0.12m and 0.2m). An opposite observations for the case of suction. The numerical results are compared with available numerical results and experimental data and a satisfactory results are obtained.


Article
Forgeability Of 25%GRPOM ( Celcon R ) To Produce Spur Gear Under Hot Conditions Through Slow Speed Press.

Authors: Talib.H.Rashid
Pages: 6186-6197
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Abstract

This research studied forgeability of preheated billet of 25%GRPOM plastic through closed die forging technique using spur gear design. The type of deformation was discussed as well. This process had done after heating the billet and die assembly at 100oC to achieve complete gear shape taking into consideration testing the product to insure no inside or outside defects with improvement in the mechanical properties. Cycle time to produce a complete shape was two minutes

Keywords

Forging --- GRPOM --- Recovery --- Dwell time


Article
Removal Of Direct Blue Dye In Textile Wastewater Effluent By Electrocoagulation
أزالة صبغة الزرقاء المباشرة من مياه الصناعات النسيجية المطروحه بطريقة التخثيرالكهربائي

Authors: Atheer M. Ghalib
Pages: 6198 -6205
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Abstract

Removal of direct blue dye by electrocoagulation method has been investigated using aluminum electrode in a bench-scale electrochemical system. Current density, NaCl concentration, electrocoagulation time, and dye concentration has been studied as effecting parameters in color removal efficiency. Increasing of current density will increase the color removal efficiency and energy consumption as well. While increasing NaCl concentration increase the color removal efficiency but it decrease energy consumption. High dye concentration is needed for extra electrocaogolation time to reach the same efficiency that obtained with low dye concentration .With current applied 0.35 amps. and NaCl concentration of 2 g/l more than 93% efficiency achieved in 14 min. of electrocaogolation time.

Keywords


Article
Utilization of Thomas model to predict the breakthrough curves for adsorption and ion exchange

Authors: Shahlaa E. Ebrahim --- Yasmen A. Mustafa
Pages: 6206 -6223
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Abstract

Fixed bed sorption processes such as adsorption and ion exchange do not operate at steady state. The design equations are differential that usually require numerical methods to solve. Thomas gives a general analytical solution for these equations. It is based on second-order reaction kinetics and the assumption of Langmuir isotherm. Computer program for the solution of Thomas model was designed using MATLAB 7.0. Four sets of experimental data are tested to show the capability of Thomas model to predict the breakthrough curves for adsorption and ion exchange processes. These data represent the sorption of o-cresol from water by activated carbon, acetic acid from air by activated carbon, phenol from water by natural zeolite, and trichloroethylene from air by zeolite-5A.The results show that there are a good agreement between the experimental data and the model.


Article
Free Vibration Response Analysis Of Buried Cylindrical Storage Tanks

Authors: Hussein Mahmood Ali --- Adrian F. Ali
Pages: 6242-6266
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Abstract

This study presents a reliable and effective idealization scheme for the free vibration analysis of buried cylindrical storage tanks. The three dimensional problem is transformed into a two dimensional one by using a semi analytical finite element procedure. Conical shell of revolution element is used. to represent the cylindrical wall, top plate, and bottom plate of the tank by an appropriate method. The Combined effect of structure-soil-fluid interaction is of primary importance as concluded in this work. The soil medium is idealized by the elastic half space model, that is, linear springs are assumed to represent the structure-soil interface, added masses and viscous dampers of soil are also included. The liquid region is treated analytically; also analytical integration is used to got the added stillness and mass matrices for hydrostatic and hydrodynamic pressure effects, respectively. The free vibration characteristics of the liquid storage tank are validated against experimen.tal and theoretical results available in literatures.

Keywords

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