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Article
California Bearing Ratio of Some Iraqi Dune Soils

Authors: ِِAbbas J. Al-Taie --- Dr. Bushra S. Zbar Al-Busoda --- Prof. dr.Yousif. J. Al-Shakarchi
Journal: Tikrit Journal of Engineering Sciences مجلة تكريت للعلوم الهندسية ISSN: 1813162X 23127589 Year: 2010 Volume: 17 Issue: 2 Pages: 1-8
Publisher: Tikrit University جامعة تكريت

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Abstract

This paper contains the results of CBR tests that performed on compacted samples of real dune sand (cohesionless sand grains) and pseudo dune sand which is a mixture of sand sized aggregate of clay and silt. The effect of compaction and soaking on the bearing values are included in this research.
The results indicated that the compacted real dune sands have high strength and low sensitivity to soaking. The 5 mm penetration of CBR of this soil is higher than that of 2.5 mm. On the other hand, the loss of strength due to soaking can be quite considerable in compacted pseudo dune sands. The CBR values obtained at 2.5 mm and 5 mm penetration are approximately equal in pseudo dune sands.
Keywords: Dune Sand, CBR, California Bearing Ratio, Iraqi Soil

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Article
Analytical Study Of Reinforced ConcreteContinuous Deep Beams
دراسة تحليلية للعتبات العميقة المستمرة

Authors: Omer F. Ibraheem --- Hosam A. Dahaam
Journal: Tikrit Journal of Engineering Sciences مجلة تكريت للعلوم الهندسية ISSN: 1813162X 23127589 Year: 2010 Volume: 17 Issue: 2 Pages: 58-77
Publisher: Tikrit University جامعة تكريت

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Abstract

Nonlinear finite element analyses is carried out using the ANSYS11 program to predict the ultimate load for two different types of reinforced concrete continuous two-span deep beams. Results of comparing analytical with experimental data demonstrates the accuracy of the program. The effects of longitudinal reinforcement and web openings are studied and showed that the longitudinal reinforcement at top and middle region has little effect on the ultimate load, and the effect of web opening location has great effect on the ultimate load especially when the load path passes through the openings centerline. Web opening location also has great effect on values and distribution of shear and normal stresses especially at opening region.
Key words: Deep Beam, Finite Element, Reinforced Concrete, Web opening

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Article
Modeling and Control of the Saturation’s Transformer
النمذجة والسيطرة لمحولة في حالة الإشباع

Authors: Ibrahim Khalil Salih --- Khalaf Salloum Gaeid --- Dr. Arif J. Abbas
Journal: Tikrit Journal of Engineering Sciences مجلة تكريت للعلوم الهندسية ISSN: 1813162X 23127589 Year: 2010 Volume: 17 Issue: 1 Pages: 16-27
Publisher: Tikrit University جامعة تكريت

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Abstract

This paper investigates the saturable transformer from modeling and control point of view. After implementing the Simulink model of the three phase transformer simulation of a three phase, two-winding transformer is used to examine the transformer under two operating conditions.
The first is the secondary terminal short circuited and the second is the secondary terminals connected to a non-unity power factor load to verify the results obtained with those predicted from any analysis using the equivalent circuit. The graphical user interface is used for modeling transformer parameters, obtaining the results, check the stability of the control system, the settling time, the Bode plot, Nyquist and Nicols chart finally recording all currents, voltages and phase shift between them in the steady state condition, initial values of states variables for the nonlinear circuit parameters.
Keywords: Transformer, Mutual inductance, Magnetic coupling, Magnetic field, Saturation, Modeling, Control and Simulink.

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Article
Mathematical Model For Autoclave Curing Of Unsaturated Polyester Based Composite Materials
نمذجة رياضية للانضاج بالاوتوكليف لراتنج البولي استر لمواد متراكبة

Author: Dr. Adnan A. Abdul Razak
Journal: Tikrit Journal of Engineering Sciences مجلة تكريت للعلوم الهندسية ISSN: 1813162X 23127589 Year: 2010 Volume: 17 Issue: 1 Pages: 1-9
Publisher: Tikrit University جامعة تكريت

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Abstract

Heat transfer process involved in the autoclave curing of fiber-reinforced thermosetting composites is investigated numerically. A model for the prediction of the temperature and the extent of the reaction across the laminate thickness during curing process in the autoclave of unsaturated polyester based composite has been developed. The governing equation for one dimensional heat transfer, and accounting for the heat generation due to the exothermic cure reaction in the composites had been used. It was found that the temperature at the central of the laminate increases up to the external imposed temperature, because of the thermal conductivity of the resin and fiber. The heat generated by the exothermic reaction of the resin is not adequately removed; the increase in the temperature at the center increases the resins rate reaction, which in turn generates more heat.
Key words: Mathematical model, Autoclave, Curing, Composite, Unsaturated poly ester.



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Article
Simulation and Evaluation of Ethernet Passive Optical Network
محاكاة وتقييم شبكة الإيثرنت الضوئية الخاملة

Author: Salah A. Jaro Alabady
Journal: Tikrit Journal of Engineering Sciences مجلة تكريت للعلوم الهندسية ISSN: 1813162X 23127589 Year: 2010 Volume: 17 Issue: 3 Pages: 43-57
Publisher: Tikrit University جامعة تكريت

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Abstract

This paper studies simulation and evaluation of Ethernet Passive Optical Network (EPON) system, IEEE802.3ah based OPTISM 3.6 simulation program. The simulation program is used in this paper to build a typical ethernet passive optical network, and to evaluate the network performance when using the (1580,1625)nm wavelength instead of (1310,1490)nm that used in Optical Line Terminal (OLT) and Optical Network Units (ONU's) in system architecture of ethernet passive optical network at different bit rate and different fiber optic length. The results showed enhancement in network performance by increase the number of nodes (subscribers) connected to the network, increase the transmission distance, reduces the received power and reduces the Bit Error Rate (BER).
Keywords: Optical Communications, Optical Networks, Passive Optical Network .

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Article
Modernization Of Electrical Installation By Using Wireless Remote Control
تحديث التأسيسات ألكهربائية باستخدامألسيطرة أللاسلكية عن بعد

Author: Dr. Mawlood M. Al – Hamad
Journal: Tikrit Journal of Engineering Sciences مجلة تكريت للعلوم الهندسية ISSN: 1813162X 23127589 Year: 2010 Volume: 17 Issue: 4 Pages: 32-35
Publisher: Tikrit University جامعة تكريت

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Abstract

Great benefits can be achieved by using wireless remote control in electrical wiring systems of buildings.
Probably the main advantage of this application is the drastic saving in wiring installations, which in turn will give higher reliability, safety and economy.
The idea of this application can be summarized in the following explanation. '' Instead off connecting each point of electrical system to individual switch by wires, a remote receiver can be situated in a place near to the point. The transmitter is used to operate the point remotely. The mains are connected to the receiver which will connect or disconnect the load as required. Many points can be connected to one receiver and can be operated by one or more transmitter.

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Article
Optimal Design of Round Bottomed Triangle Channels
التصميم الأمثل للقنوات المثلثة ذات القعر الدائري

Author: Ayman T. Hameed
Journal: Tikrit Journal of Engineering Sciences مجلة تكريت للعلوم الهندسية ISSN: 1813162X 23127589 Year: 2010 Volume: 17 Issue: 3 Pages: 31-42
Publisher: Tikrit University جامعة تكريت

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Abstract

In optimal design concept, the geometric dimensions of a channel cross-section are determined in a manner to minimize the total construction costs. The Direct search optimization method by using MATALAB is used to solve the resulting channel optimization models for a specified flow rate, roughness coefficient and longitudinal slope. The developed optimization models are applied to design the round bottomed triangle channel and trapezoidal channels to convey a given design flow considering various design scenarios However, it also can be extended to other shapes of channels. This method optimizes the total construction cost by minimizing the cross-sectional area and wetted perimeter per unit length of the channel. In the present study, it is shown that for all values of side slope, the total construction cost in the round bottomed triangle cross-section are less than those of trapezoidal cross-section for the same values of discharge. This indicates that less excavation and a lining are involved and therefore implies that the round bottomed triangle cross-section is more economical than trapezoidal cross-section.
Keywords: Open channels; Optimization; Effective cost; Channel design; Direct search.

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Article
Magnetic Circuit & Torque Analysis Of Brushless DC Motor
تحليل العزم المغناطيسي لمحرك التيار المستمر بدون فرش انزلاق

Authors: Mohamed Rashide --- Kais Wadi --- Dr . Arif J. Abass
Journal: Tikrit Journal of Engineering Sciences مجلة تكريت للعلوم الهندسية ISSN: 1813162X 23127589 Year: 2010 Volume: 17 Issue: 3 Pages: 1-12
Publisher: Tikrit University جامعة تكريت

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Abstract

This work is concerned with magnetic and torque analysis of BLDCM and with development of a method of designing BLDCM that have symmetric winding on the rotor .make significant contribution to the rotor inductance position difficult. It is also show that the prediction detent torque can be extremely sensitive to the permanent magnet by altering magnet arc width. Finally, simple lumped models that allow one to predict motor performance and characteristics as a function of main dimension, magnet residual flux density and phase current are developed. These models are used as a basis for an approach to designing BLDCM.
Keywords:Rotor construction, , Armature windings, Equivalent circuit, Torque analysis.

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Article
Modeling Of Ballistic Missile DynamicsIn Pitch Plane And It's Stability
نمذجة ديناميكية الصاروخ البالستيقي في المستوى العمودي واستقراريته

Author: Salih Mahmoud Attiya
Journal: Tikrit Journal of Engineering Sciences مجلة تكريت للعلوم الهندسية ISSN: 1813162X 23127589 Year: 2010 Volume: 17 Issue: 3 Pages: 68-73
Publisher: Tikrit University جامعة تكريت

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Abstract

Aerodynamic modeling of ballistic missile in pitch plane is performed and the open-loop transfer function related to the jet deflector angle as input and pitch rate, normal acceleration as output has been derived with certain acceptable assumptions. For typical values of ballistic missile parameters such as mass, velocity, altitude, moment of inertia, thrust, moment and lift coefficient show that, the step time response and frequency response of the missile is unstable. The steady state gain, damping ratio and undamped natural frequency depend on the missile parameters. To stabilize the missile a lead compensator must be added to the forward loop.

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Article
A Study of Horizontal Displacement of Laterally Loaded PilesUsing Finite Element Method
دراسة الازاحة الافقية لمنظومة مؤلفة من تربة-ركيزة بأستخدام طريقة العناصر المحددة

Author: Aram M. Raheem
Journal: Tikrit Journal of Engineering Sciences مجلة تكريت للعلوم الهندسية ISSN: 1813162X 23127589 Year: 2010 Volume: 17 Issue: 3 Pages: 58-67
Publisher: Tikrit University جامعة تكريت

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Abstract

A theoretical approach is used to analyze single pile and pile in group under lateral loading using two programs. The first one used the finite element method for single pile depending on plain strain condition while the second one used the characteristic load method for pile in group. Horizontal displacement for pile in group is measured while both horizontal displacement and shear stress for single pile are measured. A comparison between the results of horizontal displacement for both single pile and pile in group with the actual practical values are produced and shows a good agreement.
Keywords: lateral loading, pile, horizontal displacement, pile group.

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