Print ISSN: 1813-0526

Online ISSN: 2220-1270

Volume 19, Issue 3

Volume 19, Issue 3, Winter and Spring 2011, Page 1-111


The Effect Of Sulfur Waste And ABS On Asphalt Cement Properties

A. T. Hameed; A. R. I. Al-Hadidy

AL-Rafdain Engineering Journal (AREJ), Volume 19, Issue 3, Pages 1-10
DOI: 10.33899/rengj.2011.27005

ABSTRACT
Nineveh is one of the Iraqi provinces 400 km north Baghdad capital and having an industrial company for sulfur production. This company produces nearly 20-25% of the total production as waste materials. This research investigates the ways of recycling the sulfur waste (SW) in solving the higher cost problem coming from import of waterproofing materials and presents information on the program and laboratory test data. Materials used in test program included 40/50 asphalt cement, Alkyl benzene sulfonate (ABS) and sulfur waste (SW). Five SW contents 0, 1, 3, 5 and 7%, and 1% of ABS in terms of asphalt cement by weight were used. Tests including physical properties, compatibility, storage stability, aging properties, temperature susceptibility and water permeability were carried out in accordance with the ASTM procedure. The test results revealed that SW is a reliable material for paving asphalt cement and being readily available can be widely used in water proofing construction materials, and this offers profound engineering and economic advantages.

Keywords: Sulfur waste, Alkylbenzene sulfonate, Asphalt, Modifier, Water proofing material.

Graphical Method of Concrete Mix Design

Dr. Khalid A. Zakaria; Mohammad Hatem Mohammad

AL-Rafdain Engineering Journal (AREJ), Volume 19, Issue 3, Pages 1-12
DOI: 10.33899/rengj.2011.26991

The current research work caters for the possibility of arriving at a method for designing concrete mixes (job mix) using locally available materials by means of three prescribed properties of the mix as design pre-requisites, that is water content, water : cement ratio and aggregate : cement ratio of wide ranges to cover a good variety of practical mixes. The above mentioned three prescribed properties can be represented in a graphical solution manner using a trilinear diagram depending on the fact that the absolute volume of the concrete mixture consisting of three materials, cement, water and aggregate is the sum of absolute volumes of the three materials. As a result and from this representation a quadrilateral area can be formed which should include a wide range of mixes having all the prescribed properties mentioned above. The current work will consider the following main influencing parameters on the job mix:

1. Water : cement ratios between 0.35-0.84.
2. Maximum aggregate sizes of 20 and 12.7 mm.
3. Fine aggregate ranges of fine, medium and coarse (B.S 882-1992 [11])
4. Aggregate : cement ratios between 3.8-7.6.

A Laboratory Tool Used to Evaluate the Reflective Cracking in Overlay Asphalt Pavement

Dr. Talal H. Almudadi; Ass. Prof. Dr. Ali H. Alneami

AL-Rafdain Engineering Journal (AREJ), Volume 19, Issue 3, Pages 11-25
DOI: 10.33899/rengj.2011.27010

Abstract
The causes of reflective cracking can be either environmental and/or load associated. The simultaneous movements of an overlay caused by wheel loads (vertical movements), temperature changes, temperature gradients (horizontal movements) induce a complex stress state of cyclic bending tension, and shear within the overlay.
Different types of tools are used to simulate the mechanism of reflective cracking in the laboratory , in this research only the tool which simulates the effect of temperature variation (horizontal movement) is studied. Overlay Testing Equipment is constructed and tested in Iraq . All the tested samples are beams of dimensions 7.6cm width, 38.1cm length with different thickness. Three parameters are taken in this study, filler type, thickness of asphalt concrete beams and additives and their effects on the properties of asphalt concrete mix. From the results, the samples prepared by limestone as a filler give higher number of cycles than that prepared by cement, the samples of high thickness give higher number of cycles and the control sample gives best results than modified samples.

Keywords: Reflection Cracking, Asphalt Concrete Overlay, Filler, Overlay Tester.

The Use Of Vacuum Pressure For Water Desalination

Layth Abdul-Aleem Alannaz

AL-Rafdain Engineering Journal (AREJ), Volume 19, Issue 3, Pages 13-21
DOI: 10.33899/rengj.2011.26993

Abstract
The research focuses on water desalination by distillation process under condition of vacuum pressure. The distillation unit was elevated over the ground surface then water was sucked from it. The water was boiled at temperatures below (100)oC as a result of reaching the absolute pressure to the vapor pressure values of water at these temperatures. The distillation unit was elevated at (6.27-7.15-8.25)m over ground surface, so that the absolute pressures exerted were (37.54-27.76-18.21)kPa respectively and the boiling points were (78-72-62) oC respectively. At each elevation of the distillation unit, different values of temperature were applied on the saline water samples (with same concentration and volume). The results indicated increasing in evaporation rate with increased elevation from ground level and with increasing of the applied temperature. This is linked with increasing in evaporation energy as a result of (boiling heat flux) increasing with the depression in absolute pressure and with increasing in temperature. The average increasing in evaporation rate was (6.78)cm3/hr for each (kPa) depressing in absolute pressure and (7.41) cm3/hr for each (oC) rising in temperature. The condensation tube was designed for each boiling and evaporation process depending on mounting the condenser at atmosphere. The design was affected by the variation in temperature and pressure applied.
Key words: Desalination, Distillation, Vacuum pressure

Study of the Misalignment of the Rotary Kiln Relative to Carrying Roller Center in Cement Factories on the Stress in Bearings

Dr. Sabah. m. j. Ali; Mr. Ahmed M. Abdullah

AL-Rafdain Engineering Journal (AREJ), Volume 19, Issue 3, Pages 22-33
DOI: 10.33899/rengj.2011.26997

ABSTRACT:
Misalignment problem is considered as one of the most important and common repeated problems in rotary kiln in meanly all of cement factories. This will lead to generation of vibration and extra loads on bearing of the carrying rollers. Also a non-uniformity can occur in distribution of applied load on all the surface of the bearing which being concentrated on one or two sides of the bearing surface, and finally leads to falling the fire lining.
The present research work is concentrated on the analysis of stresses generated on bearing of the carrying rollers of the rotary kiln in new Hammam Al-Alil factory. In addition the effect of misalignment is shown on stresses distribution and it's concentration. This is important for the bearing design and those who work in bearing maintenance in this factory.
The "(ANSYS 9.0)", which uses a finite element technique, had been utilized in this program. This is a very efficient and accurate tool in stress analysis for many cases. The stresses had been calculated for the assumed cases.
The results showed clearly that the stress distribution and concentration on the bearing is altered with misalignment for each case.
Keywords: Misalignment, Rotary kiln, Techniques , ANSYS

Studying of the Gypsiferous Soil Suction Using Filter Paper Technique

Asaad M. A. AL-Omary

AL-Rafdain Engineering Journal (AREJ), Volume 19, Issue 3, Pages 26-36
DOI: 10.33899/rengj.2011.27012

Gypsiferous soils have specific feature under its suction studying. These soils contain salt solution that affects on the suction components at high water content levels. This paper investigates soil suction of three types of gypsiferous soils namely: Al-Muhallabeia, Al-Jarin, and Al-Slmanii using filter paper technique. The investigated soils were located in Nineveh province (400 Km north Baghdad capital) and found to have a gypsum content of about 35, 23, and 6%, respectively.

This study includes some factors (water content, gypsum content, and clay content) that affect the soil suction for gypsiforous soils. The effect of gypsum content on slope of the relationship between soil suction with pF unit and water content was examined.

The results revealed that there is a linear relationship between soil suction and its water content for three studied soils. Both total and matric suction values increase as soil water content decrease. On the other hand, the difference between total and matric suction values increase with soil samples water content. The soil clay content has more effect on gypsiferous soil suction than its gypsum content.
Key words: Gypsiferous soil, Soil suction, Total suction, Matric suction, Gypsum content

Modeling Effect of Saline Water With deficient Irrigation levels on Soil Salinity and Yield for Maize

Dr . A. A. A. AL-Talib; O. M. A. G. Mahmood

AL-Rafdain Engineering Journal (AREJ), Volume 19, Issue 3, Pages 34-45
DOI: 10.33899/rengj.2011.26999

Abstract
Computer model is made in (MATLAB) language to study the effect of deficit irrigation with saline water on the salts accumulation in soil and the effect extent of the lack of water and the salts accumulation on yield. The Model has been applied on summer crop, Maize, and it relies on the principle of balancing water and salt. The Model are uses the basic variables entered in the irrigation (climate data, crop type, soil type, and the rate of moisture depletion , irrigation level, the initial soil salinity and salinity of irrigation water). The results obtained from the program are (daily potential and adjusted Evapotranspiration, daily balance of water and salt, the quantities of irrigation water and Perfusion appointment, The rate of change of concentration of salts before and after Perfusion, electric conductivity of saturation extract at Slaking, calculating the relative defect of seasonal yield). study show when using a little amount of irrigation water we have a little salt accumulation in the soil, but the salt accumulation at the end of the season depends on the gross depth of irrigation water added . Low levels of irrigation led to lower proportional yield in the event that the impact of water shortage was bigger than the impact of irrigation water salinity on productivity, and vice versa. Formulation of mathematical equations to find the relative yield and seasonal actual Evapotranspiration because of irrigation water salinity and water shortage, under the condition of study area and determinants.
Keywords: deficit, salinity, Yield, depletion, Evapotranspiration

Effect of Partial Replacement of Sand with Limestone Filler on Some Properties of Normal Concrete

Rana Burhan Abdurrahman Alshahwany

AL-Rafdain Engineering Journal (AREJ), Volume 19, Issue 3, Pages 37-48
DOI: 10.33899/rengj.2011.27014

Abstract
In recent years, there is a growing interest in the use of crushed sand obtained from limestone quarries in some countries where river sand is not widely available. Besides, the demand for aggregates to produce concrete is still high while natural resources decrease. The fines content in limestone is usually high (particles with a size of 0.15-0.7 mm) which can affect concrete properties in an either positive or negative way. Studies on aggregate containing fine materials are vitally important. However, little work has been done so far on the effect of fines in crushed sand on the properties of concrete.
This paper examines the influence of limestone filler in sand on concrete properties, which include workability of fresh concrete (slump test method), compressive and tensile strength, unit weight, and ultrasonic pulse velocity. Six concrete mixtures containing different ratios of limestone filler (0, 10, 20, 30, 40, 50) % sand replacement were used while maintaining a constant water/cement ratio. The results proved that limestone filler replacing sand up to 20% without adversely affecting concrete strength.

Dual Twins in Architecture

Farhan Awad Jasim Al-Tai; Dr. Hassan M.H. Kasim

AL-Rafdain Engineering Journal (AREJ), Volume 19, Issue 3, Pages 46-68
DOI: 10.33899/rengj.2011.27002

Abstract
Dual twins in architecture have been widely spread since the middle 20th century in various parts of the world; however, the unclear and comprehensive view about the nature and reasons of the emergence of such phenomena is still not established. The current study attempts to determine the nature and reasons of the emergence of such phenomena clearly and comprehensively. In order to examine the theoretical background of this phenomena, concept of twins in language, philosophy, biological and medical sciences is reviewed in addition to examining principles of dual architectural and artistic composition and the priors of dual twins in history of architecture. Thus, the two hypothesis of the study are formed where the first states that dual twins are either identical or fraternal, related or not related materially with each other. The second indicates that unity of design is the reason behind the emergence of dual twins leading to aesthetics, integrity within the urban context.
The study has made a deductive survey of 27 of dual twin buildings around the world. The study concluded that both the hypothesis are largely met but not absolutely. There are identical and fraternal twins but not materially related with each other and characterize by a complete structural and functional independence with their visual interrelation forming both of them as one dual composition. Concepts of architectural composition aiming at breaking monotony and presenting the new were the most influential in the emergence of dual twins in architecture in addition to other functional, rational, urban and environmental causes.
Keywords: dual twins - dualism.

Design and Fabrication of the Single Polepiece Magnetic Electron Lens of Truncated Cone Polepiece Shape

Muna A. Al-Khashab; Abdullah I. Mostafah; Issam I. Ismail

AL-Rafdain Engineering Journal (AREJ), Volume 19, Issue 3, Pages 49-54
DOI: 10.33899/rengj.2011.27018

Abstract
The magnetic electron objective lens is of a great importance which limit the resolving power of the electron microscope.
The present work investigates the objective focal properties of a single polepiece magnetic electron lens of truncated cone polepiece shape of the selected geometrical dimensions for practical applications. The lens has been fabricated consist of cast shield made of mild steel combined with exciting isolated cooper coil of 500 turns.
The theoretical and experimental results presented the magnetic flux density distribution and the objective focal properties of the lens, in mode of operation when the direction of incident electrons beam facing the lens back plate of the lens.
Moreover, the theoretical and experimental results are in a good agreements.

Keywords: electron optics, magnetic lens fabrication, design of magnetic lens, objective properties, low voltage scanning electron microscope.

The effects of Reduced Temperature and Pressure on Natural Convection in Rectangular Cavity Filled with a Supercritical Water: a Benchmark Numerical Solution

Younis M. Najim

AL-Rafdain Engineering Journal (AREJ), Volume 19, Issue 3, Pages 55-68
DOI: 10.33899/rengj.2011.27022

Abstract
In this paper, natural convection heat transfer of supercritical water in rectangular enclosure has been investigated in various values of reduced temperature (0.955 1.205) and pressure (1.2 2.0). The right and left sides of enclosure considered to be isotherm with a temperature difference of , while the lower and upper sides of the enclosure was thermally insulated. The width of enclosure is 0.004m. Calculations were performed for Rayleigh number ( ), Prandtl number ( ). The values of Ra and Pr are governed by the fluid temperature and pressure which are controlled by reduced temperature( ) and reduced pressure ( ). Streamlines, isotherms and mean Nusselt numbers are presented. It is found that the temperature distribution and flow field are affected by the reduced temperature and pressure. The results also show that the maximum Nusselt number could be obtained at the same specification of geometry and temperature difference increases as the pressure reach the critical pressure.
Keyword: Natural convection, supercritical Water, reduced temperature and pressure

Study of Heat Storage in Shallow Fluidized Beds

Burhan Mahmood Ahmad Al-Ali

AL-Rafdain Engineering Journal (AREJ), Volume 19, Issue 3, Pages 69-75
DOI: 10.33899/rengj.2011.27025

Abstract

This paper presents the theoretical analysis and experimental study of the performance of a shallow fluidized bed as a storage system for thermal energy.
River sand is used as a bed with different height values and compressed heated air as an external fluidizing.
A bundle of finned tubes is used as a heat exchanger immersed in the bed for the extraction of stored energy from the bed.
Empirical correlations are offered by experimental work, which show the relations between the instantaneous local temperature within the bed and time as a function of both bed height and inlet air velocity.
Keywords: Heat, Transfer, Fluidized Beds, Heat Storage,.

FPGA based Reconfigurable 2D FFT System

Shefa A. Dawwd; Ahmad F. Al-allaf

AL-Rafdain Engineering Journal (AREJ), Volume 19, Issue 3, Pages 76-88
DOI: 10.33899/rengj.2011.27026

Abstract

This paper develops a system level architecture for implementing a cost-efficient, FPGA-based reconfigurable two dimensional (2D) FFT system. The adopted approach considers both the hardware cost (in terms of FPGA resource requirements), and performance (in terms of throughput). These two extremes are optimized based on using run time reconfiguration, double buffering technique, shared Dual Ported RAM (DPRAM) modules and the “hardware virtualization” to reuse the available processing components. The system employs two one Dimensional (1D) FFT processor each with sixteen reconfigurable parallel FFT cores. Each core represents a 16 complex point parallel FFT engine. Thus the architecture supports transform length of 256X256 complex points, as a demonstrator to the design idea, using fixed-point arithmetic and has been developed using radix-4 butterfly architecture. The simulation results that have been performed using VHDL modeling language and ModelSim software shows that the full design can be implemented using single FPGA platform requiring about 50,000 Slices.
Keywords: 2D Fast Fourier Transform Radix-4. Run Time Reconfiguration

Implementation of Multiplier less Architectures for Color Space Conversions on FPGA

Dr. Ahlam Fadhil Mahmood; Abdulkreem Mohammad Salih

AL-Rafdain Engineering Journal (AREJ), Volume 19, Issue 3, Pages 89-103
DOI: 10.33899/rengj.2011.27029

Abstract
The divergence of computers, internet, and wide variety of interactive video devices, in most of the multimedia applications, all using different color representations, is forcing the digital designer today to convert between them. The objective is to have a converter, which will be useful for number of applications with a basic function of converting from one color space to another and the inverse on same architecture. This paper presents an efficient parallel multiplierless implementation for two color space converters (RGB to YCbCr and YCbCr to RGB). The proposed architecture is based on distributed arithmetic (DA) principles which has been implemented on the Xilinx Spartan-3E XC3S500 FPGA using fewer resources. The implementation approach exhibits better performances when compared with existing implementations, Modifications have been carried out in DA to reduce the hardware complexity with better performance in area, latency and throughput.
Keywords: Color Space Conversion; Distributed Arithmetic ; FPGA; Video, Processing; Image Processing .

Discharge Coefficient for V-Notch Broad Crested Side Weir Side Weir

Amal Abd Al-Ghnai Yahya

AL-Rafdain Engineering Journal (AREJ), Volume 19, Issue 3, Pages 104-111
DOI: 10.33899/rengj.2011.27031

Abstract
In this paper the hydraulic characteristics of V-notch broad crested side weir have been experimentally studied. Sixteen V-notch broad crest weirs were constructed with six apex angles (θ=30º, 45º, 60º, 90º, 120º,and 150º)and the apex height change three times (p=5,10,15cm) for the first forth angles and change two times for the last two angles (p=10,15cm), each model can be tested by changing flow in the main channel several times and from the analysis of experimental results it was found that the coefficient of discharge(Cd) for the V-notch broad crested weir is depend on the hydraulic and geometric characteristics of channel and weir, and from the hydraulic characteristics of the main channel it was found that the coefficient of discharge (Cd) directly proportional to the main channel Froude number before side channel , and a maximum value of (Cd) can be reached for a larger acute V-notch angle , but a maximum value of (Cd) can be reached for the smaller obtuse V-notch angle. Also from the hydraulic and geometric effect for both channel and weir it is found that (Cd) inversely proportional with (y1/p) and directly proportional with (y1/h &p/h) and a maximum (Cd ) can be reached maximum for both acute and obtuse V-notch angle. Suitable equations for discharge coefficient are obtained for different apex angle, then the predicated discharge coefficient from the equations were plotted against the calculated value with coefficient of determination (R2=0.9) and it was found to be good.
Keywords: Broad Crested Weir, Side Weir, V-Notch