Al-Rafidain Engineering Journal (AREJ)

Abstract
This study presents a nonlinear analysis using the finite element method to predict
the ultimate load and mode of failure for reinforced concrete deep beams with web
openings. Materials nonlinearities due to cracking, plastic flow or crushing of
concrete and yield conditions of the reinforcing steel are considered. The capabilities
of the proposed model have been examined and demonstrated by analyzing five
reinforced concrete deep beams with web openings.
Keywords: nonlinear, elasto-perfect plastic, finite element, reinforced concrete, deep
beams, web openings

Abstract

In this research a laboratory study was carried out to investigate the scour phenomenon downstream gabions protecting rockfill weirs. The study includes the measurement of maximum scour depth and length of scour hole downstream the weir. The shape of scour hole was also studied. Three sizes of aggregate of diameters (0.7937, 1.111, 1.5875)cm were used as downstream bed protection. Three different downstream slopes (1V : 10H , 1V : 7.5H , 1V : 5H) were tested for all sizes of aggregate.
Laboratory results of this study showed a direct relation between scour depth and scour hole length with the densimetric particle Froude number; also, a direct relation with downstream slope. Two empirical equations were obtained; one for the estimation of relative scour depth and the second for the estimation of relative length of scour hole.

Key word: Scour, aggregate beds, rockfill weirs.

Abstract
Volume changes of a collapsible soil selected from Hawy Al-Kanissa in
Mosul city were studied. The Influence of addition of (5, 15 and 30) % of low (CL)
and highly plastic (CH) clayey soil were studied. Many variables as: the initial dry
unit weight, water content and applied stresses on volume change were considered.
State diagrams representing gradual volume change due to these variables were also
presented and discussed.
The main results were showed that the collapse potential (Cp) increased
continuously for samples mixed with (CL) soil while there were a maximum value at
(5%) of (CH) soil. At low unit weight, (Cp) for samples mixed with (CL) reached a
highest value at certain stress, then started to decrease, while it increased
continuously using (CH). (Cp) of soils containing (CH) was found to be less than that
mixed with (CL) soil. Concerning soil volumetric changes using state diagrams
presentation, volume change for undisturbed natural soil at low moisture content was
found less than that in disturbed samples, but the inverse was obtained at saturation.
Besides that, volume changes increased with the increase of the clay additive in
different manner for (CL) and (CH) soils.
Keywords: Clay, Collapsible soil, Volume change, unsaturated soil.

Abstract
In the present study a mathematical model using Artificial Neural Network (ANN) was developed to estimate the daily reference evapotranspiration for Mosul area (northern part of Iraq) using daily meteorological data measured over 21 years, which are believed to influence the evapotranspiration process. The data are consisting of temperature, sun radiation, wind speed, and relative humidity. These variables have been used as inputs to the ANN, while the daily evaporation was adopted as an output.
The study reveals that there is a high linear correlation between the evaporation estimated by the proposed ANN and that measured using class A evaporation pan with a correlation coefficient of 0.95. This clearly indicates the possibility of using AAN technique for estimating the evapotranspiration component, which can be calculated by multiplying the output of ANN (i.e. evaporation) by the pan coefficient. Additionally, sensitivity analyses have been conducted to study the effects of the specific variables of inputs on the proposed network's performance. It is found that ANN’s performance is highly affected when the temperature, sun radiation, and wind speed are concurrently acted, while the effect of the relative humidity was limited especially when it is accompanied by the temperature.

الخلاصة
نفذت الدراسة الحقلية في ثلاث مواقع ضمن محافظة نينوى لترب مختلفة النسجة والاستخدام بتطبيق بعض المعادلات للتنبؤ بالشد عند جبهة الابتلال من خلال تغير المحتوى الرطوبي اثناء غيض الماء في التربة باستخدام إسطوانة الغيض المزدوجة للترب المزروعة وغير المزروعة لمعرفة مدى توافق قيم الشد عند جبهة الابتلال كدالة لبعض الصفات المائية للتربة .اوضحت النتائج ان المستويات الواطئة من الرطوبة اكدت عدم ارتباط الايصالية المائية كدالة للمحتوى الرطوبي بل اعتمد على تغير الجهد الهيدروليكي . من جهة اخرى اظهرت النتائج توافق قيم الشد عند جبهة الابتلال كدالة للمحتوى الرطوبي مع جهد الشد عند جبهة الابتلال كدالة للامتصاصية المحسوبة عند المحتوى الرطوبي الاقل من السعة الحقلية.

Abstract
Mobility is the distinct feature of wireless mobile cellular system. Usually,
continuous services is achieved by supporting handoff which is the transfer of an
ongoing call from the current cell to the next adjacent cell as the mobile moves
through the coverage area. usually handoff calls are given higher priority than new
calls since it has a significant impact on the network performance. Simulation study
of the relative signal strength with hysteresis and threshold (RSS-HT) algorithm for
varying hysteresis and threshold are studies to evaluate the mean number of cell
handoffs, mean number of wrong cell handoffs and expected average signal strength.
Keywords- Cellular network, signal strength, handoff schemes.

Abstract
It is well known that the classic image compression techniques such as JPEG
and MPEG have serious limitations at high compression rate, the decompressed
image gets really fuzzy or indistinguishable. To overcome this problem, artificial
neural networks ANNs techniques are used. In this paper, we propose a bipolar
sigmoidal backpropagation BBP algorithm to train a feedforward autoassociative
neural network. The proposed method includes steps to break down large images into
smaller windows for image compression/ decompression processes. A number of
experiments have been achieved, the results obtained, such as compression ratio and
peak signal to noise ratio PSNR are compared with the performance of linear
backpropagation LBP and standard (sigmoidal) backpropagation SBP schemes

Abstract
This research tries to review the way how to form and create (the Pattern of Residential Cluster) in single – family housing in the Iraqi City. The present study defines the research problem basically as a reconsideration or reformulation of scientific and applied approaches to understand the nature of (Residential Cluster)as a big cell comparing with the small one(The Dwelling Unit), within the urban residential fabric. The research tries to approve a methodology in forming or producing patterns of these clusters through comprehensive and complementary concept regarding all components of residential physical fabric,. The research takes into consideration the concept of balance between (the part and the whole) by studying the interrelationship between the (residential cluster) and other components, and also takes the network of urban spaces within the residential fabric into consideration, in order not to neglect the value of urban space. The results in this research indicates many patterns of residential clusters with specific identify and characteristics for each. These patterns have been produced according to the mentioned methodology, that can approve wide range of created patterns in accordance with current Housing Standards in Iraqi City.

Key Wards: single family housing , residential cluster

Abstract
This work is done by turning a medium carbon steel bare which contains
0.35%C using high speed steel cutting tool. Dimensional deviation is taken as a
criterion to compare between parts produced by dry and wet cutting condition. It is
observed that, in traditional wet cutting condition by water-oil solution, an irregular
conical shape is produced and the diameter of the work piece is increased from initial
to the end of the work piece. But in the dry cutting condition the diameter is near to
the desired diameter because the decrease in the tool length due to a flank wear is
substituted due to the thermal expansion of the cutting tool. Fortunately, it is observed
that the dry cutting condition is more accurate in diameter than the wet cutting
condition.
Keywords: Dimensional deviation, Flank wear, Dry and Wet cutting condition.

Abstract
In this work, a control system for positioning and stabilizing a massive
inertial system subjected to continuous disturbances, which represents the
oscillatory motion of the base, is investigated. A hydraulic system is proposed and
simulation is used to select and test the effect of different parameters of the
hydraulic parts, particularly those of the electro – hydraulic servo valve, at
different values of the supply pressure of the hydraulic fluid.
The inertial system dynamics and the hydraulic parts are mathematically
modeled and simulated by digital computer using (MatLab). The dynamic
characteristics of the control system, such as the stability and the time response in
addition to the ability of the system to reduce the effect of the external
disturbances are examined. The results show that the control system is capable of
reducing these effects between (70% to 90%) depending on the supply pressure of
the hydraulic system and the frequency of the external disturbances. In addition,
the effect of using pressure limit valve in the hydraulic system and that of the
presence of dry friction of a relatively high value, are investigated.
Keywords: position control, hydraulic system, stabilization of inertial system,
Electro-Hydraulic Control

Abstract
The Actual occupation of Spaces in dwelling units is assummed to be coincidence with the desingated pattern of these spaces . This research aims to determine first the swerving of the actual occupation from the designated pettern , and second the factors affecting this swerving both related to dwellings attributes or occupants characteristics .
A sample of (100) dwelling units is randomly selected in Mosul For the studyو the statistical analyses of variables lead to findings which explain the effect of both dwellings and occupants attributes on the occupation pattern .
Key Words :Housing , Spaces Occupation , Post Occupancy Evaluation

Abstract
In this study, a qualitative analysis of a transverse vibration of a rotor system
with a crack that grows at an angle of 45 degrees toward the axis of the shaft is
presented. Based on the assumption that the bending stiffness of the shaft changes
synchronously with the opening / closing behavior of the crack caused by the
torsional vibration of the shaft, the equation of motion of a simple rotor system
with a shaft having a slant crack is represented by a differential equation with
parametric excitation in fixed coordinate system rotating at the operation speed of
the rotor. Finally, it is shown by the solution that the steady-state response of the
rotor system with a slant crack on its shaft induced by imbalance contains the
frequencies represented by

Abstract
Formation of concept in Architecture Design is something unusual to many student and most projects been designed with no knowledge of how to use concepts properly.
This research introduce meaning and form of concepts in Architecture. Range and scope in Academic and professional work. Also problems, which face student such as Communication, Adaptation, and the correct type, show types of concept. Research also shows types of concept and concepts hierarchies.
Applied part of this research will deal with some student' projects. Who adapt concepts. And to analyze forms and types of their concepts through different tables. Inter views have been made with students of fourth year to discover how students had been arrived to final solution

Abstract
Architecture of place is a preposition presented in the modern architectural trends, especially in post-modernisim as a reaction against modern architecture and its planning ideology of architectural unity. New trends were emerged concentrating on architecture related to place. As in Iraq. The paper discusses the importance of this subject, in order to explore the particular problem which has been represented as (lack of clarity of architecture of place in Iraqi contemporary architecture 1960-1980).
Thus the objectives of the paper has been formed and method has been specified by building theoretical framework consisting of two main items as the following: (Responses and considerations relating to architecture of place), firstly, then the application of the cultural considerations on selected architectural trends through Iraqi contemporary architecture (1960-1980), secondly, finally, concluding paradigms of dealing with context of place, thirdly.
Coclusions have been declared the importance of the role of place in works of Iraqi architects during sixties and seventies concentrating on the strong relationship between the place with its natural and cultural considerations, on one hand, and the product (building) and the human being who inhabits it, on the other hand.

Keywords: Architecture of place, Iraqi contemporary architects, Context of place.

Abstract
The research deals with architectural history as one of the basic subjects in architectural teaching and learning, exploring both its’ goals and tools. Its’ goals concentrated directly on developing mental skills of students, and indirectly on either the concept of historical continuity or the concept of historical development. Its’ tools can be defined by the procedures of knowledge communication which includes both procedures of teaching and studying history, and the scientific content to be communicated to students.

Keywords: architectural history curriculums, procedures of teaching history, historical knowledge communication, historical knowledge content.