Print ISSN: 1813-0526

Online ISSN: 2220-1270

Volume 19, Issue 1

Volume 19, Issue 1, Winter and Spring 2011, Page 1-146


Determination Of The Memory Switching Action In CdS/SiO/CdTe Structure

Dr. Luqman Sufer Ali

AL-Rafdain Engineering Journal (AREJ), Volume 19, Issue 1, Pages 1-7
DOI: 10.33899/rengj.2011.27861

Abstract
In this paper, an experimented study is presented which determines the memory switching criterion for CdS/SiO/CdTe devices. The dc. characteristics obtained from isolated devices on various glass substrates, but having the identical CdS and CdTe semiconductors with different sandwiched SiO thicknesses reveal that the device impedance at OFF state is almost determined by the tunnel oxide thickness. But the forward and reverse threshold voltages are determined by the top contact area of the device. Physical arguments are presented which adequately explain the experimental results in this paper.

Effect of Moisture Content on Some of the Strength Characteristics of Sandstone Rock in Mosul City

Mohannad Ghanem; Thamer Mohammad Noori

AL-Rafdain Engineering Journal (AREJ), Volume 19, Issue 1, Pages 1-14
DOI: 10.33899/rengj.2011.27802

Abstract
An attempt has been made to study the effect of moisture content variation on the strength characteristics of sandstone rock selected from east of Mosul city center. Both compressive and indirect tensile strengths of the rock were determined.The obtained results indicated that the water has a considerable effects on both the compressive and tensile strengths. Higher reduction in the compressive and tensile strength were observed when the moisture content percent was between (0%-4%) and (0%-8%) respectively.The results also indicated that the effect of moisture content on tensile strength is greater than it's effect on compressive strength.

Improving WiMAX Capacity Of A Cell By Applying Relay Stations And Adaptive Antenna Systems

Firas S. Al-Sharbaty; Dr. A. I. A. Jabbar

AL-Rafdain Engineering Journal (AREJ), Volume 19, Issue 1, Pages 8-21
DOI: 10.33899/rengj.2011.27866

Abstract
Worldwide interoperability for Microwave Access (WiMAX) is a broadband wireless technology based on IEEE 802.16 standard . A WiMAX cell which is to be considered in this study applies multicast mode of operation , the main limitation of maximizing the capacity of the system is the signal to noise ratio (subscribers near the base station apply 64 QAM and ¾ Reed Solomon code , while those which are near the border of the cell applies PSK and ½ Reed Solomon code to compensate for the S/N effect). Results indicate that better capacity is achieved by introducing Relay Stations (RSs) and Adaptive Antenna System (AAS) to the cell with TDD mode of operation, other factors like MAC and PHY layers overheads are studied and taken into account in the calculation of the system capacity .

Keywords : WiMAX , Overhead , Capacity , AAS , Relay Stations .

Relation Between Ultrasonic Pulse Velocity and Some Mechanical Properties of Clayey Soil Treated with Lime

F. A. M. A. Abdullah; M. A. A. Al-Atalla; Z. I. M. Abdullah

AL-Rafdain Engineering Journal (AREJ), Volume 19, Issue 1, Pages 15-25
DOI: 10.33899/rengj.2011.27807

The present study aims to obtain a relationship between the ultrasonic pulse velocity which is one of nondestructive method of material testing and some of soil mechanical and physical properties. In this study a relationship between the ultrasonic pulse velocity through the soil samples and the unconfined compressive strength, dry density and curing time was obtained in high plasticity clayey soil. The soil was compacted in the cases of natural condition in standard and modified compaction effort, and in the treated condition with ( 2,4,6,8 ) percent of lime, compacted with modified compaction effort for three percent of water content(O.M.C, O.M.C ±4) these samples cured in (25°)temperature in different curing time ( 0,2,10,20,42 ) day . After curing time end, all samples tested in ultrasonic device and unconfined compressive strength device. The results obtain from these tests, analyze and get a good relationship between the ultrasonic pulse velocity and the unconfined compressive strength, dry density and curing time with high correlation coefficient in all properties

Mobile Positioning System using Signal Strength Measurement for WCDMA System

Ahmad M. A. Salama; Farhad . E .Mahmood

AL-Rafdain Engineering Journal (AREJ), Volume 19, Issue 1, Pages 22-28
DOI: 10.33899/rengj.2011.27874

Abstract



The precise position of the mobile station is critical for the ever increasing number of applications based on location . In this paper a new approach for mobile positioning in WCDMA (Wideband Code Division Multiple Access ) cellular network is proposed . Radio Received Signal Strength Indication (RSSI) can be measured from a number of nearby base stations . Three proposed approaches (3-BS's , 5-BS's and 7-BS's) are simulated using three propagation models and the rmserror is calculated for each model. As a simulation study case, the University of Mosul area is choosed to find the position of a mobile user in the university campus .

Keywords: positioning systems ,WCDMA ,RSSI, propagation models.

The Efficiency of Using Tube Settlers technique in Comparison with the conventional Treatment in Mosul City Water Treatment

Abeer Hashim Hassan; Mohammed Suleiman Hassan

AL-Rafdain Engineering Journal (AREJ), Volume 19, Issue 1, Pages 26-34
DOI: 10.33899/rengj.2011.27809

ABSTRACT
An evaluation of the efficiency of conventional clariflocculator units with tube settlers has been done in this study within the compact units in Mosul Unified Water Project. Results of bimonthly samples were analyzed before and after treatment in the conventional project with their correspondences in tube settlers within the compact units during period of January 2003 to June 2004 in order to investigate the expected water quality variety in Tigris river. The results have shown that tube settlers are more efficient than conventional clariflocculator units in removing turbidity and phytoplankton alga at a low turbidity level less than (30 NTU) and number of phytoplankton alga between (45–59) cell/ml. )75%) of the residual turbidity and phytoplankton alga after treatment was the best in tube settlers units. Results also showed that conventional clariflocculator units are more efficient than tube settlers at the water turbidity more than(30 NTU) and number of phytoplankton alga between (63–75) cell/ml. (25%) of the total residual turbidity and phytoplankton alga after treatment was the best in the conventional clariflocculator units.

Evaluation of Aluminum Cans As A Thermal Insulator in Reinforced Concrete Slabs

Laith K. I. Al-Taie

AL-Rafdain Engineering Journal (AREJ), Volume 19, Issue 1, Pages 29-41
DOI: 10.33899/rengj.2011.27878

ABSTRACT
Thermal insulation is the most effective energy efficient technique of energy conservation available today. The main goal of energy an conscious designer is to condition the interior environment to support a level of climate comfort acceptable to users. From the past 20 years data it is concluded that temperature is at the increase and thus thermal insulation is an immediate need to be considered. Environmental problems have recently expanded due to industrial pollution and manmade products that are found in solid wastes. One of these products are the Aluminum cans. Since the recycling rate of these cans is decreasing. It is therefore the main goal of this study is to evaluate the thermal insulation of these cans through models in insulating reinforced concrete roofs and ceiling and comparing the insulation with that of Thermo-stone blocks and Polystyrene boards which are commonly used in Iraq. Results indicated that Aluminum cans are considered as a good insulator and can withstand a considerable live and dead loads beside it’s low construction cost and low weight. Finally the use of Aluminum cans in the thermal insulation will contribute in solving a part of the global environmental problems.
Keywords: Thermal Insulation , Solid wastes, Aluminum cans, Model.

Removal of Oil and Suspended Solids from Dairy Industry by Dissolved Air Flotation

Satee. M. Al-Rawi; Hamid A. Al-khashab

AL-Rafdain Engineering Journal (AREJ), Volume 19, Issue 1, Pages 35-48
DOI: 10.33899/rengj.2011.27812

ABSTRACT
Dairy liquid wastes contributes considerably in the pollution of the Tigris within Mosul city particularly when suspended solids and oil pollution are concerned. Dissolved air flotation( DAF) is introduced to tackle the discharges arise from this industry. A pilot plant is constructed for this purpose. The pilot plant is subjected to variety of operating conditions of detention time ( 6-24 minutes), recycle ratio (25-100 %), pressure(40-70 psi) and air /solids ( A/S) ratio. The results revealed that the optimum values for detention time, recycle ratio, and pressure were 18 minutes, 100% and 60 psi respectively. A statistical treatment for the obtained results to relate all the studied factors is made in order to establish the best relation that gives the best results. The percent removal of suspended solids in the dairy discharges amounted to 80 % while that of oil amounted to 86%. This highly indicates the importance of introducing this physical unit among conventional wastewater treatment units. It is concluded that DAF has many merits represented by ease of operation, considerable reduction of pollutants which may be reflected on subsequent units. Due to short detention time, this unit becomes small and adds to the economy of the treatment.

EVALUATION OF SEEPAGE AND STABILITY OF DUHOK DAM

Khaleel S. Ismaeel; Dr. Bahzad M. A. Noori

AL-Rafdain Engineering Journal (AREJ), Volume 19, Issue 1, Pages 42-58
DOI: 10.33899/rengj.2011.27885

ABSTRACT
One of the main causes of the earth dam failure is the seepage. This seepage can cause weakening in the earth dam structure, followed by a sudden failure due to piping or sloughing. For this purpose a finite element method through a computer program, named SEEP2D, was used to determine the free surface seepage line, the quantity of seepage through the dam, the pore water pressure distribution, the total head measurements and the effect of anisotropy of the core materials of Duhok zoned earth dam. First, the accuracy of the program was tested via the data of experimental dam and the results showed an acceptable accuracy of the program. The effect of the ratio of the permeability in the horizontal direction to that in the vertical direction (Kx/Ky) on seepage was tested and results indicated an increase in seepage quantity as this ratio increased. The stability of Duhok zoned earth dam was analyzed using a slope stability computer program, named STABIL2.3. The program is verified through a dam example of known factor of safety (solved by hand calculations). The results of the verification indicated a good accuracy of the program. The slope stability analysis results showed that the factor of safety decreases with the increase of Kx/Ky ratio. The analysis of the results of this study showed that Duhok zoned earth dam is safe against the danger of piping and slope sloughing under the present operation levels. Also, the present study showed that the field piezometers readings of the dam are not accurate.
Keywords: Seepage, Stability, Duhok dam

Sculptural Architecture : The Zaha Hadid's Approach

Dr. Asma Hasan Al-Dabbagh

AL-Rafdain Engineering Journal (AREJ), Volume 19, Issue 1, Pages 49-69
DOI: 10.33899/rengj.2011.27818

ABSTRACT
Previous studies have paid special attention to sculptural architecture because it concerns about architectural composition, this paid attention is also likely to be due to the fact that sculptural architecture has been a reaction to the principles and practices of Modernism, as a result of modern practical developments in the field of construction and as an aim in itself. This paper focuses on the discipline of sculptural architecture seeking its identification and subsequently the establishment of its theoretical framework based on previous research work. The paper shows that aspects of the established theoretical framework can be clearly related to the various phases through which the construction of a given building traverses, ranging from the initial phase of motivation and concept design by the innovating architect to process of building comprehension by recipient. The developed theoretical framework is then verified by addressing Zaha Hadid’s pioneering work in this field, which is used here as case study. The application of the theoretical framework has revealed a series of patterns in Hadid’s work which may be attributed to her own architectural style. Similar results to those obtained from the theoretical framework have also been made by other observers, all of which point to the special paid attention by Hadid to modern construction methods which she used symbolically and practically confirming her liberal architectural style. The revelations demonstrate the validity of the assumptions made in the development of the theoretical framework. Finally, this paper lays down a set of guidelines for other architects who wish to apply Hadid’s approach in sculptural architecture.
Keywords: sculptural architecture, Zaha Hadid .

Numerical and Analytical Study of Two Dimensional Heat Transfer Thorough an Annular Fin of Variable Thickness

Ziad M. Al-Makhyoul

AL-Rafdain Engineering Journal (AREJ), Volume 19, Issue 1, Pages 59-73
DOI: 10.33899/rengj.2011.27888

Abstract
This paper included an analytical study of a two dimensional (radial and transverse) heat flow through annular fin variable thickness analytically depending on the group of resistances by derivating the major equations of conduction and convection. The total resistance equation of fin is derived to be general and simple model to calculate the heat flow and to study the effect of fin parameters on it.
A numerical solution is added to prove the validity of the analytical solution by using a grid generation transformation-algebraic method to regulating the irregular mesh on the fin surface.
Finally, the results show a good agreement between the two solutions using a wide range of fin parameters and this study is supposed to facilitate the designing of fin to the designer.
Key words: Annular fin , Total resistance, heat transfer coefficient

Truth in Modern Architecture A Study of the concept of Truth in Selected Works

Talaat I. Alaane; Dr. Ali H. Aljameel

AL-Rafdain Engineering Journal (AREJ), Volume 19, Issue 1, Pages 70-92
DOI: 10.33899/rengj.2011.27824

Abstract:
Truth is considered as an important concept in the modern architectural discourse as it appeared explicitly within the theoretical statements and the practices of Modern Movement. This research explores the concept of (Truth) in Modern Architecture to clarify the items on which it is based and how it is produced in architectural artifacts. However, this study concludes that (Truth) is a relative concept and it is based on two types of items (conceptual and formal). These items and their related mechanisms are explored empirically in selected works from Modern Architecture. It is concluded that those items and mechanisms were varied regarding the clarity of occurrence and the mechanisms used to imply the concept of (Truth) the selected works
Key Words: Truth, Sincerity, Frankness, Modern Architecture, Truth Architecture

Design characteristics that affect usage efficiency of reading spaces in University Libraries

Niam Behnam Manona

AL-Rafdain Engineering Journal (AREJ), Volume 19, Issue 1, Pages 93-109
DOI: 10.33899/rengj.2011.27839

ABSTRACT


Post occupated buildings have formed a subject examined by several architectural studies and arose in their concluion the importance of suitable designing concepts that promote the efficiency of its use arose these ideas into light was greatly envisaged in the university libraries’ buildings in general and their reading spaces in particular, which dominate real interaction among their designing characteristics and users’ preferences.The research discusses the significance of what have been mentioned above and the reality of knowledge related to it in the architectural reality to extract the special problem related to the designing factors that are invested by designers in reading spaces which have an influence on increasing their use efficiency.
Evaluation of several previous studies has led to identifying knowledge deficiency and thus the research problem was represented by unclear theoretical knowledge which determines and describes the set of the affecting designing factors in the usage efficiency and determining its aim by revealing it. As to its methodology; it was represented by building up a theoretical framework included two major aspects one of which discusses the designing factors regarding the reading space; whereas the second includes the variables regarding the usage efficiency. Then the theoretical framework was applied in the field aspect on selected models from the libraries of the university of Mosul and determining the research population among users.
Conclusions have shown an evident variation between the effect of the designing factors on the use efficiency such that enable the designer investing, activating and determining the priorities of future designing treatments.
Keyword: Usage efficiency of building .

The Effects of Ottoman Mosques Architecture on the Mosul's Mosques Architecture )An Analytical Study of the Architectural Attributes and Elements)

Ashraf I.Mahmood

AL-Rafdain Engineering Journal (AREJ), Volume 19, Issue 1, Pages 110-122
DOI: 10.33899/rengj.2011.27848

المستخلص
يعتمد البحث دراسة مدى تأثير عمارة المساجد العثمانية على عمارة المساجد الموصلية في فترة الحكم العثماني للمدينة لأجل بيان مدى صحة بعض الادبيات التي تفترض وجود تأثير مباشر لعمارة المساجد العثمانية على عمارة المساجد الموصلية من جهه وتوضيح مدى اصالة الخصائص و المفردات المعمارية للمساجد الموصلية لاجل تحديدها وتكوين قاعدة رصينة يعتمد عليها المصمم المعماري تساعده في المحافظة على الهوية المعمارية للمدينة ولتحقيق هذا الهدف سوف تتم مقارنة الخصائص التصميمية للمساجد العثمانية حسبما طرحتها الدراسات مع الخصائص التصميمية للمساجد الموصلية المبنية او المرممة في فترة الحكم العثماني عن طريق الدراسة الميدانية وبيان التأثير ان وجد . وبعد اجراء الدراسة العملية اتضح لنا عدم صحة الفرضية القائلة بوجود تأثير مباشر بين العمارتين حيث إن كل طراز مستقل بخصائصه التصميمية وكل طراز تأثر بمراجع ومصادر مختلفة وان وجد تأثير فانه يكون بنسبة قليلة وغير مؤثر على المفاهيم التي قامت عليها هذه المساجد.
الكلمات الدالة: العمارة الموصلية , العمارة العثمانية , عمارة المساجد

Optimal Hydrothermal dispatch for Long Term Using ANN

Dr. M. S. Al-Hafid; Dr. A. B. R. Sulaiman; Dr. A. S. Al-Fahadi

AL-Rafdain Engineering Journal (AREJ), Volume 19, Issue 1, Pages 123-133
DOI: 10.33899/rengj.2011.27855

The optimal hydrothermal scheduling is the distribution of load among the generating stations. The objective function for the problem is to minimize total generating cost considering the electrical and hydrological constraints. This problem is usually solved in two stages. The first is to find the hydropower generation share, then to find the thermal generation share. This research concerns the first stage. This work uses the Artificial Neural Network (ANN) to find the optimal scheduling of the monthly water discharge over the year. The main power station of Mosul dam is considered as an application example for this study. Six input variables are chosen to be the input to the ANN. They are monthly inflow water, monthly demand water, number of the month in a year, expected next year water inflow, available stored water (water from the past year). The ANN is trained and tested by the available water flow data over the past 65 years (1931- 1995). It is found that this technique enables the utilization of whole inflow water for most of the years (within considered constraints) in spite of the great fluctuation of inflow water for these years. Besides, this technique takes into account the status of the water for last year and next year in addition to the year under study. This means that the water distribution improves the utilization of available water over three years

DESIGN OF A DUAL SYSTEM FOR HOT WATER PRODUCTION AND COOLING USING AN EJECTOR

Mohammad S.Q. Al-Dabbagh

AL-Rafdain Engineering Journal (AREJ), Volume 19, Issue 1, Pages 134-146
DOI: 10.33899/rengj.2011.27859

Abstract
This research deals with making a mathematical model for the design of a dual system for hot water production for industrial purposes as well as cooling using an ejector at a determined operating conditions, by utilizing dissipated thermal energy from a steam boiler and for a cooling capacity of (15) KW. For the system simulation, mathematical relations were presented for each component which were then combined together and programmed using (matlab) version 6.5 to optimize the system performance and design the components at this situation, using refrigerant (R-123) as the working fluid because of it's good characteristics and relatively high efficiency after a comparison study with other suitable refrigerants to be used for this system.
Satisfactory results were obtained having good agreement with previous researches and a COP value of (0.667). The results show a suitable size of the designed system such that it can be used in a wide range of cooling and hot water production purposes. Also, the effect of operating conditions variation on the quantity and temperature of hot water and system performance were studied.