Print ISSN: 1813-0526

Online ISSN: 2220-1270

Volume 17, Issue 3

Volume 17, Issue 3, Winter and Spring 2009, Page 1-128

Analysis Of R.C. Slabs At High Temperature Using Nonlinear Finite Element Method

A. Y. Al-Saati; Z. Kh. Awad; Kh. I. Mohmmad

AL-Rafdain Engineering Journal (AREJ), Volume 17, Issue 3, Pages 1-13
DOI: 10.33899/rengj.2009.39939


This paper is concerned with the Non-linear behavior of reinforced concrete slabs at high temperature at service loads. Layered degenerated shell element is used to predict the complex feature of structural behavior at high – temperature condition, such as thermal expansion, cracking, crushing, yielding and changing of materials properties with temperature. In the development of F.E model, the geometrical nonlinearity is considered, the layered element are modified to allow for temperature distribution and change of materials property through thickness .Predictions from this analysis are compared to the available experimental results and good agreements obtained.
Keywords: Nonlinear Finite Element, R.C. Slabs, High Temperature

The Utilization Of Concrete Maturity To Predict Its Compressive Strength Under Variable Conditions

I.H. AL-Zubady

AL-Rafdain Engineering Journal (AREJ), Volume 17, Issue 3, Pages 1-15
DOI: 10.33899/rengj.2009.42933

The aim of this research is to study the maturity of concrete for predicting in-situ compressive strength for any concrete mixture in any structural work based on the laboratory testing results of several concrete specimens, then finding a relationship between compressive strength-maturity mathematical models that can be used for predicting the compressive strength. Three type of mixes were used; first mix contains ordinary Portland cement (O.P.C), second mix contains sulphate resisting Portland cement (S.R.P.C), third mix contains ordinary Portland cement with an admixture (caco3) of (15%) replacement of cement weight.
Compressive strength tests at different ages) 3,7,14,28( days and different temperatures(27±2°C) (80.6±2°F)&)34±2°C) (93.20±2°F) and curing conditions of (moist and air cured). The maturity was found for concrete samples using the Plowman technique with the datum temperature at (-11.6°C) (11°F(,the actual compressive strength values found from laboratory testing were compared with the predicted compressive strength values from Plowman equation to estimate the margin of the errors involved, the error was found to be reasonable especially for the moist cured samples.

Effect of Infilled Panel on the Nonlinear Dynamic Response of Reinforced Concete Plane Frames

Mohammad N. Mahmood; M. Ahmed; Saddam

AL-Rafdain Engineering Journal (AREJ), Volume 17, Issue 3, Pages 14-29
DOI: 10.33899/rengj.2009.39946

Studying the effects of the static and dynamic loads on structures is very essential, especially in zones where the structures are exposed to severe earthquakes. In the present study a finite element program is developed for static and dynamic analysis of reinforced concrete plane frames. The main concern is to study the effects of infilled panels on the behavior of this type of structure. One dimensional Beam-Column Elements are used to represent the frame members and Lumped Plasticity Model is used to model the nonlinearity of these elements. Modified Four-node isoparametric plane stress elements with 3-DOF per node, are used to represent infilled panels. Connection between infill element and frame is either assumed to be perfect or by linkage elements which allow separation between the two types of elements. Two programs are developed one for the static and the other for the dynamic analysis and the validity of the developed programs have been checked and the predicted results indicated a good agreement with the published experimental and theoretical results.
Keywords: dynamic, finite element, frame, linkage, interface.

Effect of Water Quality of Khosar on Tigris River and Its Primary TreatmentEffect of Water Quality of Khosar on Tigris River and Its Primary Treatment

Mayada Hazim Mohammed Ali

AL-Rafdain Engineering Journal (AREJ), Volume 17, Issue 3, Pages 16-26
DOI: 10.33899/rengj.2009.42937

ركزت الدراسة على تقييم نوعية مياه نهر الخوصر الذي يصرف مطروحاته بشكل مباشر الى نهر دجلة ضمن مدينة الموصل ، وهويمثل مزيج من مياه الفضلات المنزلية والمستشفيات. ، بينت النتائج تزايد تراكيز الفوسفات لمياه نهر الخوصر بمقدار (5 ) مرات، والمتطلب الحيوي والكيمياوي للاوكسجين بمقدار (1.48,1.5) مرة عن محددات طرح مياه الفضلات للمواصفة العراقية لحماية الموارد المائية رقم (25 – ب 1 ) لسنة (1967 ) م ، كما صنفت فضلات مياه نهر الخوصر حسب الحمل العضوي بانها ذات مستوى ضعيف أذ بلغ معدل الطلب الحيوي للاوكسجين بحدود (60)ملغم/لتر. وتبين وجود مؤشرات تلوث عضوي في نهر دجلة عند المصب وبعده لمسافة تجاوزت (600)م على الجانب الايسر للنهر ، ورغم ذلك بقيت مياه نهر دجلة ضمن المحددات العراقية لحماية المواردالمائية رقم (25-أ1 ) لسنة(1967 ) م بعد اختلاطها بمصب نهر الخوصر بسبب عامل التخفيف والانتشار. كما بينت الدراسة أن مياه فضلات نهر الخوصر هي فضلات منزلية وأن قيمة ثابت التحلل للمواد العضوية (k ) بحدود( 0.1315/يوم) وهي تقع ضمن مدى الفضلات المنزلية (0.3 – 0.05/يوم ). وباستخدام نظام جريان الجرعة لتهوية الفضلات لفترات زمنية بين (1-48) ساعة ، وجد أن افضل كفاءة ازالة للمواد العضوية كانت عند فترة تهوية مقدارها (26 ) ساعة .
الكلمات الدالة: نهر دجلة، نهر الخوصر ، مصبات مياه الفضلات، تلوث المياه، مدينة الموصل

Use of Walnut (Juglans SPP.) Coat as Natural Coagulant Aid with Alum Compared with Alum Alone or Alum with Synthetic Polyelectrolyte in Turbidity Removal

Ahlam Zeki Ameen

AL-Rafdain Engineering Journal (AREJ), Volume 17, Issue 3, Pages 27-35
DOI: 10.33899/rengj.2009.42940

This research includes studying the effect of using natural coagulant aid "Walnut Coat" with alum and synthetic polyelectrolyte with alum also on turbidity removal compared with alum alone. A set of jar test was conducted on raw water of different turbidities (5, 10, 20, 40, 50, 80 and 100) NTU using different doses of coagulants and coagulant aids. Final turbidity, pH., were measured after settling. The obtained results indicated that the use of walnut coat with alum was effective in the removal of turbidities of (20, 40) NTU compared with alum alone. While the addition of polyelectrolyte with alum was found to be more effective for higher turbidities (50, 80, 100) NTU. Additionally, the average reduction in pH-value was more using walnut coat than that of using alum alone. Furthermore, walnut coat led to the formation of large, clear and easily settled flocs within the first 5 minutes of slow mixing, while same flocs appears at the end of 30 minutes of slow mixing with alum and polyelectrolyte as flocculant aid. Better sludge characteristics were obtained with walnut coat as flocculant aid, with low water content and high density which can be easily dried and disposed.
Key words: Turbidity, Tigris River, Alum, Walnut Coat, Polyelectrolyte, Coagulation, flocculation, Sedimentation.

Properties of Self Compacting Concrete at Different Curing Condition and their Comparison with properties of Normal Concrete

N. S. Al-Saffar; J. R. Al-Feel

AL-Rafdain Engineering Journal (AREJ), Volume 17, Issue 3, Pages 30-38
DOI: 10.33899/rengj.2009.39956

The experimental investigation carried out is to study the effect of curing methods on the compressive, splitting, and flexural strengths (modulus of rupture) of self compacting concrete in comparison to those of normal concrete.
The self compacting concrete consisted of Portland cement (P.C) limestone powder (L.S) (L.S 8% / 92% P.C),sand, gravel and super-plasticizer. The specimens were cured in the air and water, for the period of 7, 14, and 28 days. Three specimens were tested for each point of each property. The results showed that the water cured specimens gave highest compressive strength, splitting tensile strength and flexural strength than specimens cured by air about 11%, 10% and 11% for self compacting concrete at 28 days respectively.
The results also show that self compacting concrete gave high early strength i.e. strength before 28-days.
The failed specimens indicated that there was no segregation and a good bond between aggregate and matrix.

Keywords: Cement, limestone powder, Segregation, Self-Compaction.

Description of shape element In Architectural composition Paradigms in creating shape types In Wright's works

Shatha Yacoub Al Sheikh

AL-Rafdain Engineering Journal (AREJ), Volume 17, Issue 3, Pages 36-60
DOI: 10.33899/rengj.2009.42945

Shape is presented as one of the architectural design's basic elements, which together determine the ultimate appearance and content of the architectural form. It is the property which determine the appearance, and for which the design and composition of form are related throughout shape types which might be geometric or organic or even the two as well. The importance of this property has emerged, especially, when the architecture of 211st century in its beginnings concentrated on the principle of "the power throughout shape" by using organic forms which have complicated and daring shapes. The paper discusses the importance of this property and its creation in the designs, in order to explore the particular problem which has been represented as (lack of clarity in description shape's element and paradigms of creating its types in different architectural trends).
Thus the objectives of the paper has been formed by building theoretical framework consisting of two main items of detailed theoretical field as the following: (paradigms of identification of shape and paradigms of creating shape types) which specifies shape element, firstly, then the application of the paradigms of creating shape types on one of the important trends throughout architectural history, which is Wright's organic trend, secondly, finally, concluding paradigms of creating form's shape in Wright's architecture, thirdly.
Conclusions have been declared Wright's concentration in creating shapes of its projects on a conceptual philosophy based on the integration between the shape and the main function of the building through selected place and time, by using selected design and compositional properties in relation to nature as a source of inspiration of form's shape.

Evaluation of Ignition Method for Determining Asphalt Content of Hot Mix Asphalt Mixtures

Mohammed Y. Taha

AL-Rafdain Engineering Journal (AREJ), Volume 17, Issue 3, Pages 39-49
DOI: 10.33899/rengj.2009.39961

The asphalt content of an asphalt mixture, as binder, is an important physical characteristics and influences the performance life of flexible pavements. Traditionally, in Iraq the asphalt content has been measured in laboratory by extraction from the mixture with chemical solvents. Recently, a new technology, known as the ignition method, has been developed to eliminate the need for these harmful solvents and to make the laboratory more safer. The main objective of this work was to evaluate and use the ignition test method to determine asphalt content and aggregate gradation in hot mix asphalt mixtures. An extensive laboratory work was conducted to meet this objective, which involving more than 300 samples of asphalt mixture, with five asphalt contents and two types of aggregate of three types of gradation, were prepared and tested using ignition and extraction methods.
Data from ten laboratories was analyzed and used to determine the accuracy and precision of this test method. The study results and statistical analysis have show that the ignition method can be used to accurately and quickly determine the asphalt content and aggregate gradation of asphalt mixtures with same, if not greater, precision than the extraction method.

Key Words: asphalt content, ignition test, hot-mix asphalt, statistical analysis

Ground Water Quality of Areas Selected NE of Mousl City Used For Irrigration and Drinking Purposes

Taha Hussein Al-Salim; Lilian Yaqup matte

AL-Rafdain Engineering Journal (AREJ), Volume 17, Issue 3, Pages 50-59
DOI: 10.33899/rengj.2009.40093

The chemical characteristics of ground water samples in Bartelah and Ain Safra catchments area NE of Mosul city have been studied through chemical analysis of (11) water samples to evaluate the quality of ground water to determine its suitability for domestic and agricultural uses. Physical and chemical parameters of ground water samples such as Ca, Na, Mg, K, HCO3, SO4, Cl, NO3, Ec, TDS, pH, and (TH) were determined. Ion concentration is found to be directly related to environmental and hydrogeologic features.
Chemical parameters were analyzed graphically by means of contour maps for Ca, Na, HCO3, SO4, Cl and Ec to illustrate the spatial distribution of chemical constituents of the ground water.
Piper diagram is also used to show the suitability, type and the geochemical evolution of ground water. Richard and Wilcox classifications are also used to show the suitability of ground water for irrigation. that most ground water samples falls in the field of doubtful to unsuitable for irrigation except samples 7, 8 and 9 which they are fell in the field of good to permissible for irrigation.
Interpretation of analytical data shows that mixed cations-SO4 type, mixed cation-HCO3 type and mixed Ca-Mg-Cl type are the dominant chemical faces. Ground water is generally hard, fresh to saline and low alkaline in nature.
Key words: Water quality, TDS, Cations, Anions, EC, Piper

Developing the design of the Etherchannel switch for the enhancement of the Quality of Service (QoS) performance

Basil Sh. Mahmood

AL-Rafdain Engineering Journal (AREJ), Volume 17, Issue 3, Pages 60-71
DOI: 10.33899/rengj.2009.42912

Quality of Service (QoS) mechanisms provide the necessary level of services (bandwidth and delay) to any application in order to maintain an expected quality level. This paper studies the effect of adopting QoS on the performance of (real time) system like video conferencing. A simulation model of the real time network is built using OPNET package. The various parameters affecting the system performance are determined and different solutions to enhance the system performance are suggested .A modified switch architecture is proposed to enhance the real time performance of the system and to modify its quality of service capability .The modification includes adding Etherchannel unit which can classify data into real time or non-real time data and direct each data packet to the appropriate channel .The architecture of the Etherchannel unit is described by VHDL programming and built on FPGA chip .Accordingly , the modified switch is found to need only extra seven clock pulses to classify each data packet .

Keywords: Quality of Service (QoS), Switched Ethernet, UDP, TCP, FPGA,VHDL

Adapting Distance Relay Using Artificial Neural Networks

M. F. AL-Kababjie; Semaa M. AL-Taee

AL-Rafdain Engineering Journal (AREJ), Volume 17, Issue 3, Pages 72-82
DOI: 10.33899/rengj.2009.42915

A universal distance relay that has merits over conventional relays is designed. This relay has the ability to adapt more than one working characteristic by using an artificial neural networks technique(ANN)of the type Modified Multi-Layer Perceptron (MMLP) which uses additional nodes at the input layer to realize an adaptation through the required modifications on the distance relay characteristics. The inputs of the added nodes referred to the factors that affect the distance relay characteristic such as: fault resistance, power transfer, mutual inductance and locations of feeding sources in the system. A Matlab computer programming was used to simulate different power systems of (400, 132) KV to obtain impedance characteristic data, needed to train and test the ANN. A laboratory power system )220V( has been operated as a computer simulation model and practically under the same conditions. The designed universal relay gives good performance when tested on a computer model of this system .The small difference between the practical results and that of simulation, encourage the use of designed relay to protect transmission lines in reality.

Keywords: Artificial neural network, Adaptive Distance Relay characteristics

Design A Distributed Amplifier System Using Π-Filtering Structure

Azad Raheem Kareem

AL-Rafdain Engineering Journal (AREJ), Volume 17, Issue 3, Pages 83-89
DOI: 10.33899/rengj.2009.42921


This paper reviews in brief the principle of distributed amplifier with its classical structure. Alternation to the basic design including the use of π-filtering sections instead of T-sections in gate and drain lines is proposed. The new design method has the advantages of much gain flatness near the cutoff frequency and less inductances at the corners of the amplifier. These are great benefits make the new design to be better than the previous ones especially in modeling the amplifier in integrated circuit technology. The distributed amplifier is used in microwave applications.

Keywords − Microwave circuits, microwave filters, distributed amplifiers.

Design of Antiwindup AVR for Synchronous Generator Using Matlab Simulation

Abdelelah Kh. Mahmmod

AL-Rafdain Engineering Journal (AREJ), Volume 17, Issue 3, Pages 90-98
DOI: 10.33899/rengj.2009.42922

Automatic voltage regulator AVR is designed for synchronous generator utilizing anti windup PI controller, to keep the terminal voltage of the generator to the rated value. The simulation of the synchronous generator is done using Matlab instructions which based on d-q axes models and the designed AVR as anti wind up PI controller. The results shows when an inductive load is applied to the generator the terminal voltage drops , the AVR is automatically increasing the excitation to get rid of this the disturbance as fast as possible.

Keyword: Anti windup PI, AVR, Synchronous generator.

Reconfigurable Self-Organizing Neural Network Design and it's FPGA Implementation

Basma M. K. Younis; Basil Sh. Mahmood; Fakhraldeen H. Ali

AL-Rafdain Engineering Journal (AREJ), Volume 17, Issue 3, Pages 99-115
DOI: 10.33899/rengj.2009.42925

The use of Kohonen self-organizing feature maps in real time applications requires high computational performance, especially for embedded systems and hence neural network chips are essential. A digital architecture of Kohonen neural network with learning capability and on-chip adaptation and storage is proposed with the implementation of Kohonen Self-Organizing Map (SOM) neural networks on the low-cost Spartan-3 FPGAs. The architecture of this digital chip based on the idea that some assumptions for the restrictions of the algorithm can simplify the implementation. Using the Manhattan distance, a special treatment of the adaptation factor, and neighborhood functions will decrease the necessary chip area so that a high number of processing elements can be integrated on one chip.
Keywords: FPGA, Weight Vectors, Manhattan distance, Learning

Effect Of Non-Darcian Flow On Natural Convection Inside Rectangular Cavity With Saturated Porous Media Using Vertical Partition

Hussain; Ziad M. Al-Makhyou; Ramiz I. Al-Aboshi

AL-Rafdain Engineering Journal (AREJ), Volume 17, Issue 3, Pages 116-128
DOI: 10.33899/rengj.2009.42926

This numerical study documents the effect of an adiabatic internal flow partition on natural convection heat transfer in a two dimensional enclosure filled with saturated porous media whereas the partition attached vertically on the lower insolated wall. The study concluded the effect of partition using different lengths (LP=0.3, 0.5 and 0.7), locations (XP=0.3, 0.5 and 0.7) and different inertia effect (Fs/Pr=10-2, 10-3 and 10-4) on heat transfer with aspect ratio (A=1.0). A continuity, energy and momentum equations are analyzed and solved using finite difference with Gauss-siedel iterative method. From results, it’s clear that the partition caused a deflection on stream lines causing a disturbance in the flow patterns. This affected the heat transfer rate represented by Nusselt number. Also, for a wide range of governing parameter, it may be concluded that the partition reduces the heat transfer rate.

Key Words: Heat transfer, Porous media, Natural convection, partition, Enclosure