Print ISSN: 1813-0526

Online ISSN: 2220-1270

Volume 18, Issue 4

Volume 18, Issue 4, Summer and Autumn 2010, Page 1-86


Experimental Study of the Behavior of Fiber Reinforced Concrete Beams under Repeated Loads

Samier S. Shmas; Muna M .Abdullah; Dr.Bayar J. Al; Sulayfani

AL-Rafdain Engineering Journal (AREJ), Volume 18, Issue 4, Pages 1-9
DOI: 10.33899/rengj.2010.31560

Abstract:
Concrete behavior subjected to repeated loads is differs than the one subjected to static loads. Repeated loads caused crushing in some part of concrete due to loading and unloading process. Concrete behavior under static loads is affected by adding steel fibers, which improved many properties especially concrete tensile strength. These improvements are studied in this research under the effect of repeated loads, by testing simply supported fibrous reinforced concrete beams with dimensions (1000x150x160) mm, reinforced with different percentages of steel fibers (0.0, 0.5, 0.75, and 1.0%). Repeated loads were applied to the beams through two points and for many cycles up to failure. The physical properties and compressive strength of the concrete used was found by casting standard cylinders (150x300) mm for the different percentages of fibers. All the results show improvements in beams behavior due to fiber addition to the concrete under repeated loads, by increasing the deflection, strain, ductility and energy dissipation due to increasing of added fibers percentages.

Keywords : Repeated load, Reinforced Concrete, Beams, Steel fiber

Performance Measurements of a Wireless Internet Service Providing (WISP) System

Qutaiba I. Ali; Ahmed Z. Saeed Al-wattar

AL-Rafdain Engineering Journal (AREJ), Volume 18, Issue 4, Pages 1-16
DOI: 10.33899/rengj.2010.31503

Abstract
In this paper, a comprehensive practical test to a Wireless Internet Service Provider (WISP) system is presented. The structure of the system is investigated and its performance is measured for different time units ranging from a Day to a Year periods. The effect of the different parameters on the system behavior is determined and their contribution is detected. The goal of this study is to give a realistic picture to the behavior of such a system as a result of its users demands, network infrastructure and service management techniques.

Key word: Wireless Internet service Provider, Latency, Throughput, WLAN Delay, and User Behavior

Influence of Aggregate and Cement Source on the Compressive Strength of Concrete Mixes

Asst. Lecturer. Yaseen Ali Salih

AL-Rafdain Engineering Journal (AREJ), Volume 18, Issue 4, Pages 10-21
DOI: 10.33899/rengj.2010.31575

Abstract

In this research, (192) concrete cubes were taken from different concrete mixes incorporating coarse and fine aggregate from four different sources with two types of cement; Iraqi cement & Turkish cement. The compressive strength of these cubes was examined to know the most suitable materials to product good concrete for use in the projects of Tikrit University. The results indicate that, the aggregate from Al-Mosul source gives compressive strength higher than the aggregate from other sources. The Turkish cement gives compressive strength higher than that given by Iraqi cement.

REAL TIME IMPLEMENTATION OF FIR FILTER BASED ON TIME DELAY NEURAL NETWORK

Dr. Shefa Abdulrahman Dawwd

AL-Rafdain Engineering Journal (AREJ), Volume 18, Issue 4, Pages 17-27
DOI: 10.33899/rengj.2010.31509

Abstract

An FPGA real time Implementation of Time Delay Neural Network (TDNN) is presented in this paper. The design and all of the work are geared towards the implementation of the TDNN in a scalable fashion. The TDNN is an adaptive FIR filter with 18-bit input and 18-bit output resolution. In this paper, the filter adapts its tap weights using the Least-Mean-Square (LMS) algorithm and then stores them in FPGA memory cell. The LMS algorithm that is used for weight adaptation is off chip implemented. The input is processed through a digital tapped delay line. The FIR neural network is used for real time adaptive noise cancellation. When the filter order is 10, the filter consumes 1168 Spartan 3E FPGA logic elements.

Keywords: TDNN, FIR neural network, FPGA neural implementation.

Affect Mosul Dam Lake of climates in Mousl city before and after construct

Lelian Yaqoob Matti

AL-Rafdain Engineering Journal (AREJ), Volume 18, Issue 4, Pages 22-32
DOI: 10.33899/rengj.2010.31606

يتناول البحث دراسة مدى التأثير الذي أحدثته بحيرة سد الموصل على بيئة مناخ مدينة الموصل بعد وقبل عشرين سنة من إنشاءها. أخذت القيم الشهرية للعناصر المناخية المختلفة لمدينة الموصل لفترة عشرين سنة قبل (1966-1985) وعشرين سنة بعد (1986-2005) وتم تحليل هذه العناصر لوحظ زيادة قدرة التبريد المحسوبة وفقا لمعادلة Cena et. Al. للفترة بعد انشاء البحيرة وبنسبة تترواح بين (5 -24 )% في غالبية شهور السنة باستثناء اشهر الصيف وأيلول. لوحظ زيادة قيمة P/E بعد انشاء البحيرة مقارنة بالفترة قبل الإنشاء في أشهر الشتاء مقارنة بالاشهر الاخرى التي تنخفض فيها هذه النسبة الى ان تصل الى الصفر خلال اشهر الصيف.زيادة وتوزيع متجانس لكمية الامطار الساقطة خلال ا شهر الشتاء وشهر اذار في المنطقة التي لها الاثر الواضح على منتوجي الحنطة والشعير المزروعة في المنطقة.اما بقية اشهر الربيع والخريف فلقد كان الفرق بين الفترتين في كمية الامطار الساقطة بسيط جدا. كميات التبخر تزداد تتريجيا بعد شهر كانون الثاني وتصل اعلى قيم للتبخر في شهري حزيران وتموز بعدها تبدا كميات التبخر بالتناقص. لايوجد فرق بين الفترتين بكميات التبخر عدا زيادة واضحة في شهر حزيران وتموز في الفترة الثانية بعد انشاء البحيرة بنسبة 30%. الزيادة الكبيرة في معدلات سرع الرياح بعد انشاء البحيرة وخصوصا خلال الاشهر تشرين الثاني ، كانون الاول، كانون الثاني، شباط واذار،. اذا ترواحت نسبة الزيادة في سرع الرياح بين ( 56-67)% في حين كانت نسبة الزيادة خلال الاشهر نيسان،ايار وتشرين الاول ( 36-45 )%. اما اشهر الصيف وشهر ايلول فكانت نسبة الزيادة بسيطة مقارنة ببقية الاشهر .
الكلمات المفتاحية: بحيرة سد الموصل، العناصر المناخية، قيمة P/E ، الامطار، قدرة التبريد، التبخر.

DESIGN AND REALIZATION OF CIRCULAR CONTOURLET TRANSFORM

Dr. Jassim M. Abdul-Jabbar; Hala N. Fathee

AL-Rafdain Engineering Journal (AREJ), Volume 18, Issue 4, Pages 28-42
DOI: 10.33899/rengj.2010.31518

Abstract
In this paper, circular contourlet transform (CCT) is proposed, designed and realized. As in the classical contourlet transform (CT), a double filter bank structure is also considered in this work but in different manners. A circularly-decomposed filter bank is first used to capture the points of discontinuities in the image edges, and then followed by a directional filter bank to obtain smoothed contours. The resulting CCT contains a critically sampled filter bank that decomposes images into any power of two's number of directional subbands at multiple scales. The designed CCT is realized by 2-D lattice allpass sections with separable and non-separable 2-D functions of z1 and z2. The resulting structure preserves both modularity and regularity properties which are suitable for VLSI implementations. Objectively, the performances of the realized CCT are tested and proved to be better than the classical CT in detail image preservation. The resulting subband images also indicate the superiority of the proposed CCT.

Keywords: Circular contourlet transform, Contourlet transform, Laplacian pyramid, Directional filter bank, 2-D lattice allpass sections, Multiresolution (multiscale & multidirection) analysis.

The Effect Of Adding Ethanol To leaded Gasoline on The Performance of Spark Ignition Engine

Dr. A.R Habbo; Mr.H.S Hammodi

AL-Rafdain Engineering Journal (AREJ), Volume 18, Issue 4, Pages 33-43
DOI: 10.33899/rengj.2010.31631

ألخلاصة
أُجريت هذه الدراسة لمعرفة تأثير إضافة مادة الايثانول بنقاوة 99.2% إلى الكازولين المرصص على أداء محرك احتراق داخلي يعمل بشمعة القدح متمثلاً بعزم المحرك والاستهلاك النوعي للوقود وكذلك كمية الملوثات المنبعثة منه عند ظروف تشغيلية مختلفة شملت كل من نسبة الانضغاط وتوقيت إعطاء قدحة الاشتعال. أُجريت التجارب العملية باستخدام الوقود الجديد (الايثانول + الكازولين المرصص) وبنسب حجمية مختلفة لمادة الايثانول ابتداءً من نسبة 10% وانتهاءً بنسبة 50% وبزيادة مقدارها 10% في كل مرة لبيان تأثير إضافة مادة الايثانول إلى الكازولين المرصص على أداء المحرك وكمية الملوثات المنبعثة منه.
تم إجراء التجارب العملية عند نسب انضغاط مختلفة وهي11:1, 10:1, 9:1 بينما تم تغيير وقت إعطاء القدحة بواقع 5 درجة من درجات عمود المرفق. وتم تثبيت سرعة المحرك ((2000 دورة لكل دقيقة وعند النسبة المكافئة ( ) .
بينت النتائج إن إضافة الايثانول إلى الكازولين المرصص أدى إلى زيادة عزم المحرك والاستهلاك النوعي للوقود مع حصول زيادة طفيفة في درجة حرارة غازات العادم وخصوصاً عند إضافة الايثانول إلى الكازولين المرصص بنسب 30% فما فوق، وصاحب هذا الأداء انخفاض في نسب الملوثات الناتجة من المحرك. كما بينت النتائج أيضاً أن زيادة نسبة الايثانول المضافة إلى الكازولين المرصص عملت على رفع نسبة الانضغاط التي يمكن للمحرك أن يعمل عندها مع غياب ظاهرة الصفع (knock) المعروفة آثارها السلبية على المحرك.

EFFECT OF HIGH TEMPERATURE ON MECHANICAL PROPERTIES OF CONCRETE CONTAINING ADMIXTURES

A.H; AHMAD; O.M; Abdulkareem

AL-Rafdain Engineering Journal (AREJ), Volume 18, Issue 4, Pages 43-54
DOI: 10.33899/rengj.2010.31523

ABSTRACT
This research work includes an experimental investigation to study the effect of high temperatures on the mechanical properties of concrete containing admixtures. A comparative study was conducted on concrete mixes, reference mix without an additive and that with an admixture. Concrete was exposed to three levels of high temperatures (200,400,600) °C, for a duration of one hour, without any imposed load during the heating. Five types of admixtures were used, superplasticizer, plasticizer, retarder and water reducing admixture, an accelerator and an air entraining admixture.
Mechanical properties of concrete were studied at different high temperatures, including: compressive strength, splitting tensile strength, modulus of elasticity and ultimate strain. Test results showed a reduction in the studied properties by different rates for different additives and for each temperature, the decrease was very limited at temperature up to (200°C) but was clear at (400,600) °C.

Key words: concrete containing admixtures, high temperatures, mechanical properties.

Effect of annealing temperature on the formability of low carbon steel sheet"

Ahmed S.Abdulaziz

AL-Rafdain Engineering Journal (AREJ), Volume 18, Issue 4, Pages 44-50
DOI: 10.33899/rengj.2010.31639

Abstract
This research include a practical study on the effect of pre-annealing in different conditions and the number of forming steps on the formability of low carbon steel sheet of thickness(10)mm which is widely used due to popular industrial uses especially in the cold pressing processes. A particular specimens were annealed at different temperatures then a set of tests were applied on these specimen. It was noticed that the annealing improve the ductility of the specimens especially the temperature that equal to 550°C with (12) minute soaking time which gave the best ability of cold pressing for the specimen . Also it was found that use of two steps of cold pressing with annealing between improve the formability of the specimen as compared with the single step of cold pressing.

Key words :annealing , steel , forming , cold pressing , ductility.

Starting of the Single Phase Induction Motor using Static Switched Capacitor

Yasser A. Mahmood

AL-Rafdain Engineering Journal (AREJ), Volume 18, Issue 4, Pages 51-57
DOI: 10.33899/rengj.2010.31648

Abstract
This paper provides a method of changing the effective value of the capacitor for starting a single phase induction motor starting. This capacitor is connected in series with the auxiliary winding. Its effective value can be controlled by static switches in parallel with the capacitor through a series of pulses. The focus was on finding ways of obtaining the best effective capacitor during starting condition through computer simulation software using (Matlab). By using this method, only one capacitor is used for both the starting and running conditions and a similar starting performance can be obtained when compared with the conventional method using two capacitors. The computer simulation results are validated by building a laboratory model and comparison of results.


Key words: single phase induction motor, switched capacitor, variable capacitor, starting conditions.

Finite Element Analysis of Unreinforced Masonry Walls

Mohammed S. Mohammed

AL-Rafdain Engineering Journal (AREJ), Volume 18, Issue 4, Pages 55-68
DOI: 10.33899/rengj.2010.31528

Abstract

In the present work nonlinear finite element program written in fortran language to simulate the behavior of masonry wall under the action of monotonic loading has been developed. The masonry is modeled as a two-phase material, treating bricks and mortar joints separately, thus allowing for nonlinear deformation characteristic and progressive local failure of both bricks and mortar joints. The influence of the mortar joint is taken into account by using an interface cap model as a part of a rational unit-joint model able to describe cracking, slipping and crushing of the material. The capabilities of the program have been examined and demonstrated by analyzing two different types of masonry wall. The accuracy of the analytical results was assessed by comparing them with the experimental results and shown to be good.
Key words: Interface element, Masonry Wall, Nonlinear behavior.

Tradition Employing in Contemporary Arabic Architecture the Architect Rasem Badran " Specialty of "

Dr. Asma Hasan Al-Dabbagh; Luma Abdalwahhab Al-Dabbagh

AL-Rafdain Engineering Journal (AREJ), Volume 18, Issue 4, Pages 58-79
DOI: 10.33899/rengj.2010.31663

تناولت العديد من الدراسات الحديثة ظاهرة استثمار التراث في العمارة عموما ، وفي عمارة المنطقة العربية خصوصا ، وذلك لكونه وسيلة لإنعاش المجتمعات ، ولأنه يحمل فكرا وأسسا عقلانية وإنسانية يمكن الاستفادة منها ، لهذا جعل هذا البحث من هذه الظاهرة موضوعا لمشكلته العامة ، وسعى لتعريف التراث ، وصياغة الإطار النظري لاستثماره في العمارة العربية المعاصرة ، وذلك من خلال التدقيق في الدراسات السابقة لهذه الظاهرة ، وقد تبين إن مفردات الإطار النظري تخص المواقف الفكرية للمعماريين تجاه استثمار التراث ، وصيغ استثمار التراث ، ودرجة استثماره ، وأخيرا آليات استثماره، وقد سعى البحث إلى تطبيق هذه المفردات في دراسة عملية لأجل التحقق منها علميا ، وقد تم اختيار المعمار راسم بدران لبيان خصوصيته .
أظهرت النتائج إن المعمار راسم بدران له موقف ثابت من استثمار التراث تمثل بالموقف التطويري التأويلي، والذي ارتبط بقيم معينة لبقية مفردات الإطار النظري، وأثبتت الاستنتاجات فرضية البحث، مؤكدة بهذا أراء بعض المنظرين فيما يخص استثمار بدران للتراث تحديدا، حيث تبين احترامه وتوقيره للتراث، ولهذا يمكن للمعماريين تطبيق أسلوبه في تصاميمهم الجديدة، ولكن الاستنتاجات أثارت التساؤل حول دقة التصنيفات السابقة للمواقف الفكرية وانتماء المعماريين لها
الكلمات الدالة : العمارة العربية المعاصرة ، استثمار التراث ، راسم بدران .

Investigation of Handoff Algorithms for GSM Mobile Cellular Networks

S. A. MAWJOUD; H. A. Al-TAYYAR

AL-Rafdain Engineering Journal (AREJ), Volume 18, Issue 4, Pages 69-80
DOI: 10.33899/rengj.2010.31538

Abstract
One of the main feature of wireless cellular network is to achieve continuous (uninterrupted) services using handoff when mobile subscribers cross the boundaries of cells in the coverage area. Handoff calls are usually given higher priority than new calls initiated.
Various algorithms are investigated using simulation and the results obtained show that the received signal strength with hysteresis and threshold in the serving cell (RSS-HTser.) and the received signal strength with hysteresis and threshold in the new cell (RSS-HTnew.) are the two methods which are closely representing the cellular system environment since they contain additional constrains in Handoff (HO) execution. Simulation are carried out by varying the governing parameters including the effects of fading on the received signal strength, averaging of signal strength, hysteresis and threshold, window size on average signal strength, and the standard deviation which represent worsening signal fading.

Keywords: Cellular networks, Signal strength, Hysteresis, Handoff algorithms.

Climatic control indices in properties of forming the urban residential façade

Dr. M.H. Aljwadi; H.A.H. Alsangari

AL-Rafdain Engineering Journal (AREJ), Volume 18, Issue 4, Pages 80-86
DOI: 10.33899/rengj.2010.31678

الملخص:

شكلت تغيرات نمط المسكن الحضري في العراق خلال القرن السابق اساسا لاشكالية في قدرة واجهته على توفير الخصوصية البيئية خاصة في دورها كمرشحة فيزياوية لتحقيق السيطرة المناخية داخل المسكن.
يحاول هذا البحث وبالاستفادة من تحليل الواجهة في نتاج الواقع السكني، نقد مؤشرات الدراسات المحلية السابقة التي تناولت حل هذه المشكلة ومعوقات تطبيقها في واقع السكن ، وطرح مؤشراته الواقعية لتحسين نظام السيطرة المناخية عبر الواجهة، والتي يمكن تطبيقها في المشاريع السكنية المستقبلية وبالتكامل مع ايفاء الحاجات الاخرى للساكن في الواجهة.

The effect of drawing ratio in deep drawing process on thickness distribution along the cup

Dr.A.D.Younis

AL-Rafdain Engineering Journal (AREJ), Volume 18, Issue 4, Pages 81-86
DOI: 10.33899/rengj.2010.31547

Abstract
In the present study the effect of drawing ratio in deep drawing process on the thickness distribution along the cup (wall, base and nose) has been performed. Obviously, the drawing ratio is the one of the most important parameter has been adopted to design the drawing die. Both experimental and numerical models were carried out on various drawing ratios (1.484, 1.589, 1.739, 1.908, 2.12 and 2.332).Tthe simulation results showed that the best drawing ratio is 1.484, which gives small difference between maximum and minimum thickness distribution along the cup. To examine the simulation results, experimental tests were performed one of the drawing ratios which shows the same behavior and pattern approximately.
Keywords:ANSYS9, Deep Drawing Drawing ratio.