Print ISSN: 1813-0526

Online ISSN: 2220-1270

Volume 15, Issue 2

Volume 15, Issue 2, Winter and Spring 2007, Page 1-118

The Effect of Welding on the Formability of Carbon Steel Sheet

Waleed J. Ali

AL-Rafdain Engineering Journal (AREJ), Volume 15, Issue 2, Pages 1-10
DOI: 10.33899/rengj.2007.44961


Forming Limit Diagram ( FLD ) is considered as an important tool in the determination of the formability of metal sheets . There is a Forming Limit Curve ( FLC ) for each sheet metal shows its formability, limit strains and forming regions. It is required some times to butt welding of two or more sheets of different thicknesses to get one blank to be formed latter , such as in some parts of car body . In this work the effect of electric arc welding on the forming limit diagram, of carbon steel , was studied .It was noticed that welding affects the forming limit curve ,where the major and minor strains are lowered for the steel sheet.

Finite Strip Method For Fixed Ended Plates

Dr. Mereen Hassan Fahmi

AL-Rafdain Engineering Journal (AREJ), Volume 15, Issue 2, Pages 1-12
DOI: 10.33899/rengj.2007.44946

Finite strip method (FSM) is an effective method for analysis of slabs, slab bridges, slab girder bridges, box girder bridges and other different type of structures. In most previous studies the derivations of the stiffness matrix based on the assumption, that the boundary condition is hinged at both ends.
In this study the derivations are extended to determine the stiffness matrix and load vector for the fixed ended slab strip using the minimum total potential energy method. Two slab girder bridges are analyzed by finite strip method and the results are compared with the exact and finite element method solutions and showed good agreement.

KEYWORDS: Finite strip method, Fixed ended bridges, Harmonic function, Polynomial function and Slab girder bridges.

Effect of hospital laboratory chemical effluents on the effecincy of biological treatment of waste water

Tariq Ahmed Mahmood; Zena Fakhri Ismaeel

AL-Rafdain Engineering Journal (AREJ), Volume 15, Issue 2, Pages 11-25
DOI: 10.33899/rengj.2007.44963

This paper focuses on the effect of laboratory chemicals on the efficiency of the biological treatment of wastewater for effluents mixed with laboratory waste and other unmixed with it, Two bench scale batch reactor were used .The first reactor feeded with effluents without chemicals , the second reactor feeded with effluents mixed with chemicals, in order to compare the removal rate of (COD) and the growth of (MLVSS) according to concentration of (MLVSS) (1000,1300, 2000,2500) mg/l at fixed value of (COD)for three hospital(Ibn seena,Ibn alatheer,Alkhansaa) .The result showed that the highest value of removal achieved at (F/M=0.16) and (MLVSS=2500) that in depended at the first of reaction ,also showed that the inhibition effects because of laboratory Chemicals appears through inhibition in the removal of (COD) and growth of (MLVSS).The removal efficiency was about (93-96)%for the first reactor and about (85-90)% for the second reactor .Its also showed that its very necessary follow regular ways in order to reduce its effect on the biological treatment unit. keywords:(biological treatment of wastewater, biological treatment of hospital wastewater)

Effect Of Types Of Bearing On The Load Distribution Among Girders Of The Bridge

Eman K. Ibraheem; Dr. Mohammad N. Mahmood

AL-Rafdain Engineering Journal (AREJ), Volume 15, Issue 2, Pages 13-29
DOI: 10.33899/rengj.2007.44950


The present paper involves three-dimensional nonlinear analysis for reinforced concrete bridge deck consisting of three main girders. Finite brick element is used to predict response of the bridge under monotonically increasing static loads up to failure.
A main concern is given to the effects of boundary conditions at the supports, and their effects on the behaviour of the bridge. Three types of supports were considered, these are simple support, elastomeric pads and a simple springs. The study includes also the effect of boundary conditions on the failure load, the load distribution amongst the main girders, and variation of bearing reactions in both pre and post cracking phases. The study shows that the method of representing the supports significantly affects the distribution of the loads among the main girders of the bridge.
Key Words : Bearings, Bridge, Finite Element, Load Distribution, Nonlinear Analysis, Reinforced Concrete.

Quality Variation of Tigris River and Effect on the Performance of Water Treatment Units at Al-Salamia Plant

Hala Hikmat Nadhim; Lilian Yaqup Matti

AL-Rafdain Engineering Journal (AREJ), Volume 15, Issue 2, Pages 26-37
DOI: 10.33899/rengj.2007.44964

This paper focuses on the evaluation of Al-Salamia water supply treatment plant was undertaken for the influent and effluent characteristics twice a week for the period from January 2004 till the end of December 2004 from low lift pump which represents river water sample; after sedimentation tanks; after filtration tanks and after adding chlorine, Physical and chemical measurements (nitrogen, PO4, turbidity, pH, Ec, Hardness and residual chlorine) were analyzed data to assess the performance of plant and the efficiency removal of turbidity. Nutrients (nitrogen, PO4) range between (0.065-0.19) (0.15-0.52) mg/l respectively, which support the algae growth and led to the blocking in intake. Ec, pH and hardness values are found to be (440-854)um/cm2 ,(7.7-8.6) and (185-303) mg/l respectively. pH values decrease after adding alum and chlorine and reaches 7.4 . The performance of the plant in terms of turbidity removal ranges from 60.58% to 42.86% when effluent turbidity ranges from (2.9 to 8.2) NTU. Paired T-test was used to attain the main objective of this study regarding the turbidity removal efficiency of each units .

The Effect Of Particle Size Distribution (Psd) Concept Of Coarse Aggregates On The Water Demand Of The Concrete Mix”

A. A. Zakaria; Dr. Khalid; Koja; Ghanim; Al Saffar; S. I; Nadiya

AL-Rafdain Engineering Journal (AREJ), Volume 15, Issue 2, Pages 30-41
DOI: 10.33899/rengj.2007.44953

The effect of particles size distribution of the coarse aggregates on the water demand of the concrete mix was studied and analyzed using the concept of particles size distribution in so far as they deviate from the avera size or fineness modulus as indicated by the standard deviation of the sample.
Six concrete mixes 1:2:4 by weight (320 kg/m3 cement content) were designed for a given slump of (30-60) mm. The main variable being the gradation of the coarse aggregates.
The results showed that an increase in the S.D of the coarse aggregate particle distribution resulted in an increase in the water demand of the mix, this was further substantiated by a decrease in the resulting compressive strength. An extra 38 similar concrete mixes were selected randomly from the literature for further supporting evidence.

Keywords: Particle size distribution, Water demand, standard deviation, average size of aggregate

Stage –Discharge Relationship For The Hydrometrey Station at Mosul

Eng. Arwa Abdulrazak Jamaal; Dr. Basil Khether Dawood

AL-Rafdain Engineering Journal (AREJ), Volume 15, Issue 2, Pages 38-46
DOI: 10.33899/rengj.2007.44965


Data of daily stage - discharge for the Tigris river have been collected for the years (1977 – 2002 ). Suitable analysis was done to find a new relation between stage-discharge which must be followed to find the discharge from the stage. Trend analysis for stage has been done to see how the stage can be changed in future, which shows a decrease with time. From the relation between max discharge, probability, and stage the inundated areas were determined depending on the contour map of Mosul town, the inundation areas have stages between (220.89-221.3) m when the channel of the river reaches its maximum capacity.

Key words : stage , Flood , Time Series

Compressive and Tensile Strength of Natural Fibre-reinforced Cement base Composites

Dr M. A. Ismail

AL-Rafdain Engineering Journal (AREJ), Volume 15, Issue 2, Pages 42-51
DOI: 10.33899/rengj.2007.44954


This paper describes the effect of the addition of various volume fraction (0-%4) of short natural fibres on the behavior of the composites. An experimental work has been carried out to study the mechanical properties of Roselle fibre-reinforced cement composites. The results show that the tensile strength of composite increases, (this increase in strength is about 53%), while the compressive strength decreases as the fibre volume fraction is increased.
Keywords: Cement , Composites ,Compression , Mechanical Properties Natural Fibre ,Roselle Fibre, Strength, Tensile.

Laboratory Study Of Scour In Stone Beds Downstream Triangular Plan Form Weirs

Mr. Ibrahim A.I.Al-Hafith; Dr. Bahzad M.A.Noori

AL-Rafdain Engineering Journal (AREJ), Volume 15, Issue 2, Pages 47-62
DOI: 10.33899/rengj.2007.44966

In this research, the phenomenon of scour downstream triangular plan form weirs on stone beds were studied experiment
ally. The study deals with the measurement of maximum scour depth and the length of scour hole downstream the weir. The shape of scour hole was also studied. One hundred and eight runs were conducted in a laboratory channel. Three sizes of crushed stones of diameters (0.7142, 1.111, 1.5875)cm were used. Four weir-heights (10,15,20,25)cm were tested for all sizes of crushed stones. The effect of tailwater depth on scour depth was studied for all weir-heights except 10 cm because submergence appeared, while, total number of tailwater depths tested were thirty six. Experimental results of this study showed direct relation between scour depth and scour hole length with the densimetric particle Froude number, but the scour depth and scour hole length had inverse relations with both relative tailwater depth and relative drop. Two empirical equations were obtained; the first for the estimation of relative scour depth and the second for the estimation of relative length of scour hole. A simple design method was presented to obtain the length and thickness of rock protection downstream triangular plan form weirs depending on field data and size of available rocks.

Key words: scour , stone beds , triangular weirs.

Factors affecting the static operation of Erbium Doped Fiber Amplifier(EDFA)


AL-Rafdain Engineering Journal (AREJ), Volume 15, Issue 2, Pages 52-70
DOI: 10.33899/rengj.2007.44955


Doping a part of the optical fiber core by ( ) ions with the availability of external pumping power (pump laser),will lead to the formation of erbium-doped fiber amplifier (EDFA).The performance of this optical amplifier depends on the parameters in this article which form this optical amplifier (the power and the wavelength of the pumping laser,the power and wavelength of the input signal, amplifier length,ion concentration).The effects of these quantities on the action and performance of erbium amplifiers such as amplifier gain,gain saturation,noise figure and out power of the amplifier are investigated.

Keywords: Erbium Doped Fiber Amplifier(EDFA), Single mode, Population inversion.

Ornament In Architecture Particularity of Ornament in Modern Movement

Shatha Yacoub Al - Sheikh

AL-Rafdain Engineering Journal (AREJ), Volume 15, Issue 2, Pages 63-83
DOI: 10.33899/rengj.2007.44967

Ornament is considered one of the significant concepts in the recent architectural thought , it has emerged clearly as a mean of creating the highest levels of beauty in Architecture ,especially in late-modernisim and post-modernisim as a reactiom towards the problems of modernity connecting with the creating ornamental productions as well as what is known about modernity from rejecting ornamentation . The paper has discussed the importance of the concept concentrating on a well-known realism about ornamentation in the architectural reality, in order to explore the particular problem which has been represented as (the ornament in modern movement).
Thus the problem of the paper has been formed and its objective and method has been limited, by building a comprehensive and theoretical framework consisting three main items of detailed theoretical field as the following : (intellectual attitudes related with ornament, means and methods of creating ornament and aims of ornament) which limit the concept in Architecture, firstly, then the application of the items on selected architectural trends through modernity like Corbusier and Mies, secondly, at last concluding the particularity of ornament in modern movement, thirdly.
Conclusions have been contradicted with the familiar expression of modernity rejection to ornament, and it has been clear that modernists used ornaments in their projects but in a new style, and modernists ornaments were considered as symbols through architectural form expressing their era.

Keywords: Ornamentation, decoration, adornment, embellishment in architecture

Numerical Study Of The Effect Of Some Forming Paramiters In Hemispherical Punch Stretching

A.Alsaati; F.M.Alkaissy; W.J.Ali

AL-Rafdain Engineering Journal (AREJ), Volume 15, Issue 2, Pages 71-84
DOI: 10.33899/rengj.2007.44958

In this work a finite element simulation is used for the hemispherical punch stretching test. The effect of strain hardening exponent, the original thickness of the sheet metal and the coefficient of friction between the punch and the blank on the formability of sheet metal are investigated. The results of this simulation are used to derive an empirical formula combining the simultaneous effect of the three parameters on the final thickness of the sheet. This formula is used to derive a numerical criterion which can be used in a separate finite element program for predicting the initiation and the position of localized necking. The effect of the three parameters on the level of the forming limit diagram is also investigated. An emphasis is put on the relation between the coefficient of friction and the strain path.

Keywords : Localized necking, empirical formula, strain path

Historical Evolution of Type in Architecture

Dr. Maha Abdul Hameed; Dhuha Abdul Gani Abdul Aziz

AL-Rafdain Engineering Journal (AREJ), Volume 15, Issue 2, Pages 84-104
DOI: 10.33899/rengj.2007.44968

Typology is an important concept in architectural theory and practice . It contributed particularly to the theory and practice of Post -Modernism as an alternative design strategy to address problems arising from Modernism . It emphasized the role of history in the architectural creation .
The research discussed the concept in an exploratory study concerning the development of the concept through out history to isolate the main issues in relation to which concept was discussed . Six issues emerged : nature and essence of type, origin of type, type and interpretation, type and the generation of form, type and classification and finally type and history
The conclusion of the study enabled to put foreward a more comprehensive definition of the concept capable of application in a variety of contexts .

Rationale of Deficit Irrigation Planning and Management

Dr. Ahmed Y. Hachum; Dr. Anmar A. Al-Talib

AL-Rafdain Engineering Journal (AREJ), Volume 15, Issue 2, Pages 85-103
DOI: 10.33899/rengj.2007.44960

A simulation model for evaluating the effect of water availability in the soil and salinity on yield under deficit irrigation has been developed. The model is based on water volume balance concept for scheduling irrigation using different levels of allowable percent water depletion. To take the effect of salinity on yield into consideration, the crop evapotranspiration is linked to the salinity level in the soil water using the procedure described in FAO (1998). The model was used to study the effect of both water deficit and salinity build-up during the growing season on yield of cotton for different scenarios, assuming zero leaching, with different irrigation water salinity levels, and allowable percent depletion of water in the root zone.
To verify the validity of the model, preliminary one year data from experiment conducted in northern Syria during the summer season of year 2004 for cotton are used. The data included four deficit irrigation levels using drip irrigation system: full irrigation (no deficit); applying 80%, 60%, and 40% of full irrigation. The experiment was laid out in three replications. The main outcome of the study included useful relationships between relative yield with relative crop evapotranspiration as affected by different levels of deficit irrigation and water salinity. Given the salinity of irrigation water and selecting a cretin level of percent water depletion, the relative evapotranspiration (Etcadj/ETc) can be predicted. Upon knowing the relative evapotranspiration, the relative yield under the given conditions can be also evaluated.

Keywords: deficit irrigation, irrigation scheduling, soil salinity, simulation, evapo-transpiration, leaching requirements.

The Attributes of Spatial Distribution of Mosques in Islamic City Until the Beginning of 20th Centuary - A Case Study of Mosul

Momtaz H.D. Aldewachi

AL-Rafdain Engineering Journal (AREJ), Volume 15, Issue 2, Pages 105-118
DOI: 10.33899/rengj.2007.44969

Abstract :
The significance of mosques in the definition of an Islamic city-pattern is acknowledged by all general theories of the Islamic city . Mosques are a common feature to all Muslim cities as well as they have had a continuous existence and exert a profound influence upon the cities . Friday mosque represents the core of the Islamic city where other urban facilities are sequenced around .
Due to vast expansion of Islamic cities , more Friday mosques were erected to fulfill the occupants‘ needs . These had their religious justifications . The spatial distribution pattern of these mosques represents a phenomenon that deserves study assuming that this distribution is goverened by some rules.This is to be examined by adopting the nearest neighbor analysis and by selecting Mosul old town as a case study .The research is ended with findings that describe and explain this distribution pattern .
Key Words:Islamic City , Mosques , Nearest Neighbor Analysis .