Al-Rafidain Engineering Journal (AREJ)

Abstract
In this paper the hydraulic characteristics of branching flow in open channel has been studied, a main channel was used with a branching channel connected with three angles (30°, 60°, 90°) with four bed slopes (0.001,0.0015,0.002,0.0025)and at each slope five values of discharge were pass in the mainchannel(13, 14, 15, 16 and 17.25) l/s. For each discharge five depths of water were allowed in the branching channel in each experiment. The results of the experiments indicated that the discharge ratio increases with increases bed slope of the branching channel. It was also found that the highest discharge ratio is obtained in the angle 60° then the angle 90° and then angle 30°. The results also showed that the relationship between thedischarge ratio and Froude number is linear and direct proportional to the Froude number in the upstream main channel and in the branching channel, and inversely with the Froude number in the downstream main channel. The relationship between discharge ratio and the ratio of water depth in the branching channel to water depth in the downstream main channel is linear and inverse. An empirical equation to calculate the discharge ratio was observed, with a coefficient of determination (R2) equal (0.953).
Key Word: Branching channel, Branching channel slope, open channel, Branching flow and Branching angle.

ABSTRACT
In this study, eight locations on U-turn median openings in Duhok City were investigated about gaps or lags of traffic opposing and delaying traffic turning left. Other data was collected from the scene like conflicts with turning traffic, travel speed, and volumes of opposing and parallel flow. Accident frequency experienced near U-turn openings location for three years (2005-2007) was collected too.
Analysis of data using statistical methods show different empirical models correlating independent variables like , gap length travel speed , traffic volume , approach width , conflict rate…etc. with dependent variables like , delay time , accident rate , and percentage of drivers accepting or rejecting gaps . Average lag obtained to control safety of studied locations was 3.5 sec.
Key Word: Gap Acceptance, Duhok

Astract
Operational Research had its origins during the Second Word War as the result of the cooperation of scientists with senior officers of the Royal Air Force , to look into several military problems .
" In 1947, G . Dantzig developed an efficient method called , the simplex method, which can be used with the aid of the computer to solve linear programming problems even with thousands of constraints and thousands of variables in order to find their optimal solutions " [2] .
This research is aiming to revise comprehensively the procedure of Simplex method and to use the computer programme WINQSB in order to obtain the optimal decision to minimize the production cost for three different jackets models in Najaf Factory for Men Clothes .

Key Word : Linear Programing , Simplex , Minimization , Constrints , ObjectiveFunction , Optimal Sulotion ,Variables , Pivot Operation .

Abstract
The distance relay is suffering from under-reach in its performance. This is because of some transient disturbance, which may happen when the power flows and swings. Besides that the power swings as a consequence of some fault cases. In this paper a new distance relay has been suggested and modeled for detecting stable and unstable power swings.
This relay is known as out of step relay (OOS). The method employed is to measure the rate of change of the positive sequence impedance of the relay which supervise the trip signal that comes out of the distance relay. It allows the distance relay to work, if it detects an unstable power swing or a fault. On the other hand it blocks it if the power swing is stable. The new relay have been modeled and simulated using MATLAB-SIMULINK software programs.
The performance of this relay has been tested on an equivalent two sources system. The results prove that the suggested relay is active and fast. Thus overcoming the limitation of the distance relay in case of under-reach. The results also show that the new relay has the ability in discriminating between the types of faults, that occur during power swings.
Key Word: Power swing, Distance relay , Out of step protection technique.

Abstract
Islamic architecture is considered to be a unique example that reflects the impact of structural formation systems in establishing its form; the structural relations represent the most important items and bases of architectural structures, especially at the abstract level. The structural relations form the basic foundation which represent the most important aspect in producing the formal structure of any building thus they are considered to be the most important method in describing the physical reality of architectural production . Stemming from the above fact, the study focuses on the structural relations that form the plans. The problem of the study is that structural relations which form the plans of Khans buildings in Islamic architecture are not clear. The aim of the present study is to clarify the specialty of Muslim architect intellectuality in the formation of a particular mechanism or method to form and design studied plans with specific functions like khans. To achieve the aim of the study a theoretical framework of structural relations is built depending on modern studies on formation of those relations on the bases of the statistical analytical method. The results arrived at show that the structural relations which form and construct the plans of Khans buildings are characterized by uniqueness as a distinguishing character of Islamic architecture some of these types of building are the khans, though they differ in their architectural design, their date and ever their geographical location. This in turn gives an indication and proof of the Muslim architect creative role in determine the distinguished identity of his architecture with the incentive of Islamic cultural intellect held by that architect all over the places of his civilization whenever and wherever he exists.
Key Word : Formal Composition , Relationships Formative , Khan , Islamic architecture

This study discusses the design and execution of a house overlooking Tigirs river in old city of Mosul. The researcher has resorted to the design principles and architectural elements besides ornamentation which combined modern techniques and traditional aspects in old Mosul houses. The problem of the study has been determined through the loss of the traditional methods and the identity of local architecture. The paper aims to propose a house design with its technique solutions in traditional Mosul houses to express the heritage and modernity .
The research proposal is that the characteristics of local architecture in old city of Mosul , may be lost if we can't offer to the society a contemporary Arabic Islamic architecture. The study revealed important conclusions and suggestions through the practical application.

Key Word: Mosul houses, principles and architectural elements.

Abstract

In this work , the influence of the location and depth of transvernce cracks on the natural frequency of cantilever beam was studied. The study of the cracked beam has been carried out theoretically, starting from derivation of equation for the additional strian energy in the presence of a crack .The equation of natural frequency change due to the presence of a crack can also be calculing for cantilever beam . The results showed that the presence of the crack causes a decrease in the values of the natural frequencies of beam as the decrease in the value of natural frequencies of the beam with cracks in the area nearer to the supports, was lesser than in areas away from the supports. Finally, the theroetical results were compared with the experimental results of previous researches, which were in a cloce agreement especially for the behavior of beam curves as function of the crack depth.
Key Word : Beam , Crack , Natural Frequency, Depth , Location

In this study a cross-classification technique is used to predict trip production travel among 20 traffic analysis zones located within Dohuk city residential area. Two and three level cross-classification matrices has been used to describe dis- aggregated trip rates/Du, total vehicle trips/Du and total private trips/Du. Car ownership is considered as the main factor causing trip production related to other household characteristics like family size income level and workers number.
Out of this study it is concluded that data can be used directly in the prediction analysis of trip rates. Family size and workers number are the most effective independent variables. Number of cells can be reduced if larger sample size are used in the prediction analysis as well.
Key Word : Cross Classification, Dohuk

Abstract
In this study, the public transport in Dohuk City is investigated.
Questionnaire forms were prepared and used to collect socio-economic data from
transit riders, their origins and destinations, trip purpose, and their mode of
transport. Low standard of living residents in this city are captive to use public
transport, with out scheduling of transit, especially males of (18-25) years old.
The people who are using transit their home are far a way from the road for a
distance more than (200)m. Out of the data analyzed some conclusions and
recommendations are presented in order to be considered by experts and
specialists in this city to take them under option in the future to develop the transit
routes and modes.
Key Word: Public Transport Dohuk

Abstract
In this paper, An-Non destructive test procedure was used to study the effect
of depth and Location of circumferential cracks on the vibration characteristics
of the rotating shafts. The first procedure was to measure the natural
frequencies of rotating shaft before renewing circumferential cracks with
different dimensions and depths from the bearing of the rotating shaft using
(vibration analyzer B & K type 2515) apparatus to analyze the vibrational
characteristics during the rotation and comparing it with mathematical analysis
using the method of mounting the rotating shaft. Secondly, a crack of certain
depth and dimension away from the rotating shaft bearing was made. The
measurements of the natural free vibration due to the presence of the crack
were carried out. The study took into consideration the diameter and the length
of the rotating shaft, beside the measurement of the natural free vibration of the
shaft. The practical results showed a decrease in the natural frequencies of
rotating shaft when the crack prested. This decrease was more when the crack
located in areas near the bearing than was located away from the bearing.
Key Word : Shaft, Crack, Circumferential, Frequency, Depth.

ABSTRACT
In this study, trip attraction phenomenon has been studied for 20
residential out of 28 traffic zones located within Dohuk city urban area composed
of more than 300,000 in residents. Home-interview travel data provided for the
city are used in addition to special data collected to perform the trip attraction
analysis .Attraction trips are classified into seven types and selected as dependent
variables while other variables like number of dwelling units, employment,....etc.,
are selected as independent variables in the SPSS package to obtain the most
statistically well accepted predicted attraction trip models. Some models like
HBW trips is constant eliminated with good (R2) value. HBSH and HBOH trips
are showing weak correlation with their independent variables like amount of
CBD area and number of retail sales located within CBD area.
Key Word: Trip Attraction