Print ISSN: 1813-0526

Online ISSN: 2220-1270

Volume 15, Issue 3

Volume 15, Issue 3, Summer and Autumn 2007, Page 1-100


Effect of Coarse Aggregate Gradings on Some Properties of No-Fines Concrete

Hassan E. Al-Khatib; Khalid A. Zakaria

AL-Rafdain Engineering Journal (AREJ), Volume 15, Issue 3, Pages 1-8
DOI: 10.33899/rengj.2007.45058

The present work deals with the effect of graded coarse aggregates on some properties of no-fines concrete.
Seven mixes of no-fines concrete having (1-6) (cement - coarse aggregate by weight) and (50-60%) flow were tried with different gradation of aggregates (first three were single sized, the remaining four were graded aggregate with different maximum aggregate size).
The main parameters investigated were the compressive strength, flexural strength, dry density (unitweight) and thermal conductivity.
The results showed that the use of graded aggregates as compared to single size resulted in an increase in both compressive and flexural strength in the order of (56% and 21%) respectively and a lesser increase of dry density and thermal conductivity in the order of (3% and 8%) respectively.

Keywords: No-Fines Concrete, Aggregate Gradings, Maximum Aggregate Size.

Investigation of Shear Response of Fibrous Reinforced Concrete Beams Using Incremental-Iterative Method

N. S. Al-Saffar; S. A. Al-Ta

AL-Rafdain Engineering Journal (AREJ), Volume 15, Issue 3, Pages 1-18
DOI: 10.33899/rengj.2007.45048

Abstract
The brittle nature of concrete leads to a brittle shear failure, which the designers try always to avoid by making the flexural strength of the member less than the shear strength. The addition of steel fibers to concrete converts the brittle characteristics of concrete to a ductile one, such fibers are uniformly distributed and randomly oriented throughout the volume of the concrete. The steel fibers are suitable as shear reinforcement especially in thin members such as slabs and thin webs, where the use of shear reinforcement is not possible.
An incremental- iterative method which utilizes the equations of equilibrium, compatibility of deformations and materials constitutive relationships is employed to find out the complete response of beams under increasing shear loads. The method gives detailed information about the flexural and shear stresses in concrete, steel stresses, cracks initiation and propagation and failure loads. The results obtained such as failure load and failure pattern showed good agreement with some published experimental results.

Study of Microstructure and Some Mechanical Properties of Ceramic Matrix Composite Material

Salim Aziz Kako

AL-Rafdain Engineering Journal (AREJ), Volume 15, Issue 3, Pages 9-20
DOI: 10.33899/rengj.2007.45070

Abstract

The aim of this research is to study microstructure and some mechanical properties of ceramic matrix composite material. Powder of Al2O3 was used as ceramic material after had been pressed by different pressures (58 Mpa, 117 Mpa and 176 Mpa) in metallic mold. The sintering process has been preformed at 1200oC for two hours. After that, the porosity percentage has been measured and the samples were heated to 700oC and then immersed in the molten pure aluminum and (Al-2.26% Mg), and heated to about 1000oC for half an hour. Then, the samples were cooled to 650oC. Microscopic tests and x-ray diffraction analysis has revealed zones with different hardness and with different structures. Moreover, the results showed that the adhesion between the ceramic matrix and the deposited metal depends on the molten metal type and the percentage of magnesium content of aluminum.


Keywords: Composites, Ceramic-metal bonding, Infiltration

Free Vibration Analysis Of Rectangular Plates Using Higher Order Finite Layer Method

J. H. Haido; A. A. Abdul-Razzak

AL-Rafdain Engineering Journal (AREJ), Volume 15, Issue 3, Pages 19-32
DOI: 10.33899/rengj.2007.45049

الخلاصة

في هذا البحث تم استخدام طريقة الطبقة المحددة ذات النسق العالي المعتمدة على الخط العقدي المساعد وذلك لتحليل الاهتزاز الحر لصفائح المستطيلة. تم اجراء تحليل الاهتزاز الحر باستعمال الطريقة التكرارية العامة لجاكوبي وبهذا توجد الترددات الطبيعية وانماط الاهتزاز. تم الاخذ بنظر الاعتبار تأثير اختلاف المادة والابعاد للصفيحة على تحليل الاهتزاز الحر لها.
تم دراسة عدة امثلة لاظهار الفعالية الجيدة لطريقة الطبقة المحددة ذات النسق العالي باستخدام السطح العقدي المساعد في تحليل الاهتزاز الحر للصفيحة.

Air Pollution and Rainwater Properties in Mosul City

S. S. Abdelwahab; T. A. Mahmood; Riyadh M. Al-Obaidi

AL-Rafdain Engineering Journal (AREJ), Volume 15, Issue 3, Pages 21-31
DOI: 10.33899/rengj.2007.45072

Concentration and cumulative depositions of some major air pollutants (especially Lead Pb and Cadmium Cd ) was measured in six locations distributed with certain patern in Mosul city .It was possible to survey more than (10) separate rainfall storms during the period of study.
Locations near the city center exhibited the highest Cd and Pb value due to heavy traffic .
The level of Cd and Pb is still moderate, but due to probable effect on Tigris and groundwater as well as direct air quality, it is important to control sources of these two heavy metals in the future.

Setting Of Distance Protection For Ehv Doubled Circuit Line By Using Quadrilateral Relay

Yousuf Mohammed Younis; Dr. Abdul Ghani A. Abdul Ghafoor

AL-Rafdain Engineering Journal (AREJ), Volume 15, Issue 3, Pages 32-44
DOI: 10.33899/rengj.2007.45073

This study describes the setting of distance protection for quadrilateral distance relay for double circuit lines which work at Extra High Voltage (EHV) by using (MATLAB SIMULINK) to simulate the three phase faults and states of earth faults for operation at different conditions taking into consideration the factors which effect on the measured impedance by relay especially the effect of zero mutual reactance to achieve the best setting.
The results proved that the setting with earth fault is the same as with phase fault. Also the change of setting factor causes undetermining of the fault location accurately. Also the results proved that the effect of intermediate station causes under reach and the reactance setting for backup zones tend to match among the different operation states.
Keywords: Protection, Distance, Relay, Setting.

Improving the Throughput of a Network using VLAN Switch Techniques

Mohammed Basheer Abdullah; Dr. A.I. A. Jabbar

AL-Rafdain Engineering Journal (AREJ), Volume 15, Issue 3, Pages 33-49
DOI: 10.33899/rengj.2007.45051

Abstract
High throughput with minimum delay is the ultimate demand being required from any network. Traffic congestion is the major problem that deteriorates the performance of a given network. Although switches help to a large extent in improving the traffic efficiency, but this is not the case with large scaled networks (WAN for example). VLAN switches play important roles in further improvements of network performance. The available types are based on port number and the new versions are based on MAC address, both types suffer from lack of security. The proposed VLAN switch provides higher network security because it is based on a simultaneous port and MAC functions. This benefit justifies the slight reduction in the throughput-delay performances as compared with the other types.

Keywords: VLAN, Switch, Throughput, Delay, MAC

Design of DAQ Card to Control the Speed of DC Motor Using ISA Slot

Firas Ahmed Alderzey; Dr. Abdelelah K. M

AL-Rafdain Engineering Journal (AREJ), Volume 15, Issue 3, Pages 45-60
DOI: 10.33899/rengj.2007.45082

Data acquisition card has been designed as a card connected to the industrial standard architecture (ISA) slot in the motherboard of a Pentium III personal computer in order to control the speed of a DC motor in real time. A program in C++ language has been written to realize and implement an algorithm of the controller and to get in and out of the signals to and from the designed card. The two sampled signals, the speed of the DC motor and the current in the armature, are processed by using digital proportional plus integral (PI) control and the output signal is the actuating signal for a thyristor bridge to control the speed of DC motor. The transient response for current and speed are drawn in PC monitor in the real time with different colors using graphics.

Keywords: Data acquisition, card (DAQ), ISA, speed control, DC motor, PI controller.

New Adaptive Non _ communication TL Protection Scheme with Three Phase Auto_Reclosing

Dr. M. F. Al-Kababjie; Dr. Nathim Sh. Rasool

AL-Rafdain Engineering Journal (AREJ), Volume 15, Issue 3, Pages 50-59
DOI: 10.33899/rengj.2007.45053

Abstract
In This paper a new adaptive non-communication method offers 100% Over Head Transmission Line fault clearance instantaneously, is presented. This Adaptive scheme adjusts distance Measuring Protection covering full TL in First zone with out waiting the communication inter-tripping signals, with high percentage successful three phase Auto_ Reclosing rate. This has been achieved by arrangement of three instantaneous, fundamental frequency, rms Under voltage Supervisory Relays controlling Auto_Reclosing command applied to the Circuit Breaker. The researchers presented a new philosophy to restore Over Head TL in more reliable and dependable method than the common existing one. The method utilizes a three phase monitoring Voltage Relay at each end of the OHTL which control the Reclosing Command. This new method is applicable approximately to all types of TL protection Relays (conventional or Modern Numerical Relays).
Key-Words: Non communication TL protection, Adaptive Auto_Reclosing Relays, Distance Measuring Protection.

Matlab-Based Design and Implementation of Time-Frequency Analyzer

Soad Taha Abed; Abdul-Bary Raouf Sulaiman

AL-Rafdain Engineering Journal (AREJ), Volume 15, Issue 3, Pages 60-72
DOI: 10.33899/rengj.2007.45055

Abstract
Spectrum analysis uses Fourier analysis for detecting the spectrum of a signal. The signals to be analyzed must be stationary that their spectra must not varying with time. For signals whose spectra varying with time (non-stationary) such as seismic signal, biomedical signal, speech signal, Joint Time-Frequency Analysis (JTFA) must be used. The work is to design PC- based Joint Time- Frequency Analyzer including the methods that used to calculate and display energy in Time-Frequency domain. These methods are the Short time Fourier transforms (STFT), Wavelet Analysis (WT), and Wigner-Ville distribution (WVD). Using the Graphical User Interface (GUI) for the Matlab software, front panel is designed as control panel involving all functions and tools necessary for the analysis.
Hardware requirements for interfacing the signal to the PC are considered and designed. The sound card used for signals in the audio range. External signals can be recorded, displayed, measured, stored and processed in time-domain, frequency-domain, and time-frequency domain.
Keywords: Digital signal processing, JTFA, Time-Frequency Analyzer

Methods Of Crime Prevention Through Environmental Planning and Design

Maha Akram Sadala

AL-Rafdain Engineering Journal (AREJ), Volume 15, Issue 3, Pages 61-77
DOI: 10.33899/rengj.2007.45085

Abstract
The role of the architectural environment :


Some modernization and immigration have accompanied the fast transferring from the traditional environment to the modern one. The complication of Mans life leads to the loss of the social unity in-between the old and new combination of societies. Besides, it results too discover new kind of societies suffer from financial and economical crisis that its causes have shown the dangerous effect on the city safety. One of the most important conclusions is the creation of criminal environment that would be inhabited by outlaws and these areas would be far away from the justice jurisdiction.
Mixing the usages of the land creates duality in the areas results out of the handling of these lands. The criminal density and existence is controversially related to a simple gathering downtown .
Key Words: Crime Prevention , Environmental Design , Modern Design.

Mathematical Modeling For Multi-Layer Optical Fibers

Dr. Manaf G. Said; Dr. Abdulghafoor I. Abdullah; Dr. Maan M.Shaker

AL-Rafdain Engineering Journal (AREJ), Volume 15, Issue 3, Pages 73-82
DOI: 10.33899/rengj.2007.45056

Abstract
A mathematical model to solve a scalar wave equation based on weakly guiding approximation for multi-layer (or multi-step) optical fibers is numerically carried out. The suggested numerical method is suitable to any multi- layer index profile (including W-fiber and conventional fiber) and sufficiently accurate if fiber materials for successive layers have small index differences. The general characteristics of multi-layer fiber such as cutoff wavelength and dispersion are obtained employing this model.


Keywords: optical fiber, multi-layer and dispersion

The Impact of Break-Through Streets on Changıng The Spatıal Confıguratıon Of Old Mosul

AL-Rafdain Engineering Journal (AREJ), Volume 15, Issue 3, Pages 78-91
DOI: 10.33899/rengj.2007.45089

Abstract
Mosul is one of the cities that appeared before Islam. Later on it was reformulated according to the islamic planning principles. It remained a model of an arabic islamic city, till the beginning of the twentieth century, when it had witnessed the construction of a number of wide and straight streets penetrating the urban texture of the traditional city, leading to the destruction of its social and physical structure. Then, break-through streets started to be more convenient strategy adopted by the planning authorities to realize their urgent objectives for raising the quality of life in the traditional city of mosul. After critically reviewing the previous literature, it was concluded that none of those studies have dealt, scientifically and objectively, with the problem of defining the impact of break-through streets upon the spatial organization of Old Mosul. This defect was adopted as the problem of this study aiming at the definition of that impact.
Suitable methodology was adopted to realize the study objectives, using space syntax techniques to analyze and describe the spatial organization of Old Mosul before and after the adoption of break-through streets strategy.
The conclusions provide a more clear description of the spatial organization of the old city of Mosul before and after the penetration of break-through street

Keywords:Break-ThroughStreets,SpatialConfiguration,OldMosulCity

Optimal Reservoir Sizing for Small Scale Water Harvesting System at Al-Hader in Northren Iraq

Dr. Mohammad E. Mohammad; Dr. Ahmed Y. Hachum

AL-Rafdain Engineering Journal (AREJ), Volume 15, Issue 3, Pages 83-97
DOI: 10.33899/rengj.2007.45057

A procedure is presented for determining the optimum reservoir size for supplemental irrigation using Linear Programming technique. The volume of water stored depends on the available runoff during the time interval considered along the rainy season, and the water demand which also varies depending on stage of plant growth. The runoff amount is estimated using the well-known Soil Conservation Services (SCS) curve number method. The required input data for the model are the daily rainfall depth for each time interval, soil type, construction cost per unit volume of reservoir, loss of economical return per unit area of land left as a catchment, and the maximum allowable catchment area which depends on total available area of land considered. The computerized model consists of two parts; in the first part, the program formulates the input data in the form of Linear Programming problem, while in the second part the program solves the problem by the Simplex method. The model is applied using data for Al-Hader area in Nineva Governorate. The long-term mean annual rainfall of the selected site is about 150 mm. The results showed that the most economic design is the one in which the required harvesting area is about three quarters of the total area under consideration. In this case the yield is sub-maximal, but most economical, and the irrigation depth is only about 87.5% of the case that gives the maximum yield. The required reservoir volume for the most economic design is about 111 m3/ha of the land area considered.
Keywords: linear programming, modeling and simulation, reservoir sizing, supplemental irrigation, water harvesting.

Experimental Study of the Sound Insulation for the Building Materials in Iraq

Ziad M. Al-Makhyoul; Ali

AL-Rafdain Engineering Journal (AREJ), Volume 15, Issue 3, Pages 92-100
DOI: 10.33899/rengj.2007.45093

Abstract
The study of acoustic insulation for some materials which were used in most building is investigated in this paper to reduce the noise and distribance which generated from the different sources. The object is to the best comfort to the human. A practical device is made by author and is used in this work. Some of these parts are made in the workshop of mechanical engineering and the other apparatus measurements. The concrete block, thermostone and fire block are used as walls for buildings. The glass was used with thick (4,6) mm and two layer of glasses with thick 4mm with 10 mm gap, thirospore and wood are used with thick (20,40)mm and thickness of (3,6,12)mm respectively. The comparison between above material shows that the concrete block is the best material being made from the concrete, as a comparison with other constructions. It was notice when the ration of mass to density for any material was high, the sound insulation for this material becomes excellent.
Key words: Sound insulation , building materials , buildings