Abdulhussain H.rafesh
Volume 5, Issue 4 , December 2012, Pages 0-0
Abstract
In this study fulfilled, prediction of fatigue life for alloy steel (CK45) at the several cases:
As received after shot peening after immersed in 36% Mgcl2, 30 day shot peening for specimens after corrosion.
All tests carried out under constant amplitude load, rotating bending at stress ratio (R ...
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In this study fulfilled, prediction of fatigue life for alloy steel (CK45) at the several cases:
As received after shot peening after immersed in 36% Mgcl2, 30 day shot peening for specimens after corrosion.
All tests carried out under constant amplitude load, rotating bending at stress ratio (R = -1) and room temperature.
The following conclusions are obtained:
The fatigue strength increased 11% with shot penning process The fatigue strength decreased 18% after corrosion in corrosive medium The fatigue strength increased 14% with shot penning process after immersed in corrosive medium.
Wahab Altamemei; Ali Abd
Volume 5, Issue 4 , December 2012, Pages 0-0
Abstract
The present aims to simulate the energy consumption in the systems of air conditioning, for the purpose of determining the optimal system which features consume less energy and meets the requirements of the thermal condition. Hence, the design of a computer program language (Visual Basic 5) to determine ...
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The present aims to simulate the energy consumption in the systems of air conditioning, for the purpose of determining the optimal system which features consume less energy and meets the requirements of the thermal condition. Hence, the design of a computer program language (Visual Basic 5) to determine the energy expended by the air – conditioning equipment for three different systems and at different periods of time. This program is designed according to the American Society of Heating, refrigeration, air conditioning Engineering and also depending on the data manufacturers of air conditioning equipment.
Program was used on a building located in the city of Baghdad has been designed three different system.
The research reached the energy consumed in the refrigeration compressor main factor in determining the optimal system and the others equipment does not constitute a small percentage, hitting 15% in intensive water – cooled and 8% in intensive air – cooled systems. And the different between the actual consumption and simulation value it is not moor 7%
sada abd alkhaliq alyasri; Ibtisam muhamad alhamidi
Volume 5, Issue 4 , December 2012, Pages 0-0
Abstract
According to the control charts as one of the statistical methods that lead to monitoring and improving the efficiency of the production process, there for we use control charts for mean and range for drawing control charts for compressive strength of bricks in al-Qadisya brick factor.
The compressive ...
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According to the control charts as one of the statistical methods that lead to monitoring and improving the efficiency of the production process, there for we use control charts for mean and range for drawing control charts for compressive strength of bricks in al-Qadisya brick factor.
The compressive strength tests are down for ten patch no .during march 2012, each patch contain ten samples, the LCL and UCL for brick compressive strength are (109.494, 140.892) kgcm2 respectively while Iraqi specification limits are 110 kgcm2 for type B that close nearly from LCL of factory limits that gives an idea for production type in the factory is most nearly from type B. By using the control charts we can follow the compressive strength of bricks inside the factory where if the results of tests are outside control chart limits we must investigate and correct the deviation.
Mahmoud A. Hassan
Volume 5, Issue 4 , December 2012, Pages 341-346
Abstract
This study aims to investigate: first, study the effect of changing the reinforcement percentage by fibers on mechanical properties (Impact, tensile, and compressive strength) for composite material consist of Araldite resin reinforced by chopped glass fibers with density (2.6g/cm3) .glass fibers was ...
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This study aims to investigate: first, study the effect of changing the reinforcement percentage by fibers on mechanical properties (Impact, tensile, and compressive strength) for composite material consist of Araldite resin reinforced by chopped glass fibers with density (2.6g/cm3) .glass fibers was mixed with araldite resin in different weight reinforcement percentage (20%, 40%, 60%) . the best results was obtained with large reinforcement percentage (60%). Second, study the effect ofthe same above reinforcement percentage on thermal conducting of composite material, where the result show increased thermal conducting with increasing percentage of reinforcement. Fourier equation was used to calculate the changing in thermal conductivity coefficient (k) for composite material.
Basim Khalaf Jarulla
Volume 5, Issue 4 , December 2012, Pages 347-353
Abstract
This paper presents a design of dual frequency band operation nearly square patch antenna for IEEE 802.11b,g (2.4Ghz-2.4835GHz) and IEEE 802.11a (5.15GHz-5.25GHz)by using a patch antenna. The patch and ground plane are separated by a substrate; the radiating patch have two pairs of orthogonal slits cut ...
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This paper presents a design of dual frequency band operation nearly square patch antenna for IEEE 802.11b,g (2.4Ghz-2.4835GHz) and IEEE 802.11a (5.15GHz-5.25GHz)by using a patch antenna. The patch and ground plane are separated by a substrate; the radiating patch have two pairs of orthogonal slits cut from the edge, this antenna has wide bandwidth in the frequency band of (WLAN) and with a return loss ≤ −10 dB from 2.4 GHz to 2.48 GHz and from 5.12 GHz to 5.32 GHz exhibits circularly polarized far field radiation pattern. The proposed antennas have been simulated and analyzed using method of moments (MoM) based software package Microwave Office 2009 v9.0. The results show that the antenna has dual band frequency operation by using slit load.
Manal Hameed Jasem
Volume 5, Issue 4 , December 2012, Pages 354-366
Abstract
The analysis bending characteristics of the composite specimen formed from steel and aluminum sheets with different thicknesses were studied here experimentally, theoretically and numerically by using finite element method.
The results show that the deflection decreases in nonlinear relationship with ...
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The analysis bending characteristics of the composite specimen formed from steel and aluminum sheets with different thicknesses were studied here experimentally, theoretically and numerically by using finite element method.
The results show that the deflection decreases in nonlinear relationship with increase steel thickness, the maximum difference for the deflection between the experimental and finite element results was (11 %). While the modulii of elasticity and equivalent stiffness of the composite specimen increases with the increase the steel thickness.
Also the results show that the tension and compression stresses change to the bottom surface and to the top surface of the composite specimen and that depend on the position of neutral axis of the this specimen.
Hassan A. Nasir
Volume 5, Issue 4 , December 2012, Pages 367-376
Abstract
Wide-Band Code Division Multiple Access (W-CDMA) is designed to offer more flexible wide band service which cannot implement by all the current cellular systems. The performance of a W-CDMA is limited by the synchronous transmission that users are creating between them during transfer the information, ...
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Wide-Band Code Division Multiple Access (W-CDMA) is designed to offer more flexible wide band service which cannot implement by all the current cellular systems. The performance of a W-CDMA is limited by the synchronous transmission that users are creating between them during transfer the information, and a result of losing synchronous properties it becomes more difficult for the users to maintain reliable communication.
In this paper, an algorithm is proposed in which improved the window block correlation tracking to solve this problem. That this mechanism depends on the system estimator to calculate the threshold of error in time and determine the value of the Power Delay Profile PDP at the point of synchronization by relying on guess the behavior of the PDP adaptively. Computer simulation tests are used to examine the performance of the proposed algorithm with different channel conditions, AWGN and user movement and the results show that it less complexity and faster in decision to get the synchronization as compared with the traditional algorithm.
Essam L. Esmail; Farah Kamil Abid Muslim
Volume 5, Issue 4 , December 2012, Pages 377-393
Abstract
Most mechanical CAD software used in mechanical design involves different types of decisions. All these decisions require coordinate-geometric and descriptive data. The objective of this work is to establish software programs for designing and analyzing rivets for boiler shells as an example to use ...
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Most mechanical CAD software used in mechanical design involves different types of decisions. All these decisions require coordinate-geometric and descriptive data. The objective of this work is to establish software programs for designing and analyzing rivets for boiler shells as an example to use rivets in industry. In general rivets are considered as mechanical elements of wide range application.
A software program using Visual Basic Version 5 with ACCESS database is used for design of rivets. When the user inters the input data to the system and depending on existing database, the software carries out a series of complex computations, after which it produces a comprehensive report that includes all engineering dimensions and efficiency.
The program, designed in this research, has feasible ability to deal with data base in an easy and reliable way especially for unprofessional users. This is a database that can be updated and edited at any time to get proper results. The program can be applied also to different types of riveted joint.
Israa F. Jasim
Volume 5, Issue 4 , December 2012, Pages 394-406
Abstract
Roads in Iraq are performing poorly with pavement life much shorter than the expected. The high traffic intensity in terms of commercial vehicles, the serious overloading of trucks and significant variation in daily and seasonal temperature of the pavement have been responsible for early development ...
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Roads in Iraq are performing poorly with pavement life much shorter than the expected. The high traffic intensity in terms of commercial vehicles, the serious overloading of trucks and significant variation in daily and seasonal temperature of the pavement have been responsible for early development of distress like rutting, fatigue and thermal cracking on bituminous surfacing. One of the advantages of the Marshall Mix Design method is that the performance of the mixes can be expected for local materials and environmental impact.
The Superpave mix design method differs from the Marshall Mix design methods by using performance-based and performance-related criteria to design the proper asphalt mix. This allows a direct relationship to be drawn between the lab and field performance of the asphalt mix.
This technology has a tremendous potential to be implemented in Iraq, which will pay itself with higher performance and longer lasting roads. Hence, there is need to have a comprehensive study comparing the design of bituminous mixes using both Superpave and the Marshall method of Mix Design.
The main objective of the study is the comparison between traditional Marshall Design method and the Superpave system design method in the wearing course mixes in flexible pavements. This process will be carried out by evaluating the volumetric, mechanical properties and moisture susceptibility.
Maher Sabah Abdulmahdi
Volume 5, Issue 4 , December 2012, Pages 407-423
Abstract
In this research, a fiber reinforced composite rod fixed from one end, while the other end is left free and subjected to a torsional excitation and freely vibrates. A fiber volume fraction of 40% is considered to rod of interest. Four various fibers and four matrices are taken to construct the rod in ...
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In this research, a fiber reinforced composite rod fixed from one end, while the other end is left free and subjected to a torsional excitation and freely vibrates. A fiber volume fraction of 40% is considered to rod of interest. Four various fibers and four matrices are taken to construct the rod in order to introduce the different shear moduli and modular ratios to investigate their effects on the natural frequency under torsion. The problem is manipulated using software of Ansys V.12 adopting the element type of (beam 188). The elastic properties of the materials are determined using software of Matlab v 6.5. The results show that maximum natural frequency is at (Gf/Gm) of (1.86), besides the results has shown that the matrix shear modulus has the most prominent effect on the natural frequency. A comparison is made between the results obtained numerically and these calculated by the exact analytical solution. A good and reasonable convergence between them is found ranging from 82.58% up to 85.59%.
Ahmed I. Ahmed
Volume 5, Issue 4 , December 2012, Pages 424-438
Abstract
The mechanical properties of asphalt mixtures used in highways construction depend to large extent on the type and quantity of the used asphalt. With time any asphalt pavement can exhibit various distresses that will eventually lead to the pavement failure.
Various types of additives and modifiers have ...
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The mechanical properties of asphalt mixtures used in highways construction depend to large extent on the type and quantity of the used asphalt. With time any asphalt pavement can exhibit various distresses that will eventually lead to the pavement failure.
Various types of additives and modifiers have been used in asphalt to mitigate the distresses. Fiber is one of the additives used for this purpose. The principal function of the fiber is to provide additional tensile strength in the resulting composite. This could increase the amount of strain absorbed during the fatigue and fracture process of the mixture.
In local asphalt pavement, the severity of permanent deformation and thermal cracking has been increased due to the increase in track axle loads, tire pressure, and the difference in pavement temperature, therefore, the modified dense graded mixtures with polypropylene fibers suggested for use in highway wearing courses to provide adequate resistance to permanent deformation and to provide additional tensile strength in the resulting composite.
The effects of variation in polypropylene fiber content, asphalt cement content, aggregate gradation and testing temperature are evaluated through the results of Marshall Methodology, indirect tensile strength, indirect creep test, and ultrasonic testing.
The results obtained from this study showed that the PPF improved the mixture’s performance in several unique ways against the anticipated major pavement distresses.
The addition of (0.3%) polypropylene fiber by weight of total mix with type (A) aggregate grading will help in produce more flexible mixtures that are also more resistant to permanent deformation and thermal cracking.
The relationship between the dependent and independent variables was examined by descriptive statistical analysis. The SPSS statistical package was used to perform this analysis.
Hussam A. A. Rehman
Volume 5, Issue 4 , December 2012, Pages 439-450
Abstract
This work focus on studying the mechanical characteristics of polypropylene and carbon fiber reinforced no fine aggregate concrete, containing different percentages of fiber. This work was carried out using several tests. These tests were workability fresh and hardened density, compressive strength, ...
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This work focus on studying the mechanical characteristics of polypropylene and carbon fiber reinforced no fine aggregate concrete, containing different percentages of fiber. This work was carried out using several tests. These tests were workability fresh and hardened density, compressive strength, splitting tensile strength and modulus of rupture. Tests were performed for specimens at ages of (7, 28) days. The test results indicated that the inclusion of fiber to the pervious concrete mixes did not affect the compressive strength significantly, while the splitting tensile strength and the modulus of rupture were improved significantly. Test results indicated that, the modulus of rupture of (5%) carbon fiber pervious concrete specimens are three times that of the control specimens, while the modulus of rupture of (5%) polypropylene fiber pervious concrete specimens are two times that of the control specimens. The percentage increase in tensile strength for polypropylene mixes containing fiber by volume fraction of (1%, 3%, 5%) were (93%, 101% and 129%) respectively and the percentage increase in tensile strength for carbon mixes containing fiber by volume fraction of (1%, 3%, 5%) were (170%, 177% and 220%) respectively.
Hussein Abdulmuttaleb Ali khan
Volume 5, Issue 4 , December 2012, Pages 451-465
Abstract
The principal reason for monitoring water quality has been, traditionally, the need to verify whether the observed water quality is suitable for intended uses. The present study was conducted on Al Kufa river in Al-Kufa city in the aim of studying the concentration levels of some water quality parameters ...
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The principal reason for monitoring water quality has been, traditionally, the need to verify whether the observed water quality is suitable for intended uses. The present study was conducted on Al Kufa river in Al-Kufa city in the aim of studying the concentration levels of some water quality parameters (BOD, PO4, NO3, pH, TU, Cl, and dust particles).
Samples of raw water were collected and analyzed from Kufa river station during a period of eight months, starting from November until June 2010. The purpose is to assess the level of parameters measured and their effects on the river. Statistical analysis used to describe the relations between parameters of water quality with regression analysis done by using "Data Fit" program version 9.0 software.
This study showed that the discharging of domestic sewage, detergents, agricultural effluents with fertilizers and industrial waste water from adjacent areas causing some contaminants increased.
It was noticed that the NO3 has highest positive correlation with PO4 and pH has highest negative relation with PO4 and NO3,
Finally, precipitated dust particles have highest negative correlation with pH as a result of acidic chemicals in dust particles.
Salam Adil Mutlag
Volume 5, Issue 4 , December 2012, Pages 466-476
Abstract
Premature failure of flexible pavements has a large problem in many Iraqi roads with drastic increase in truck axle loads. It is necessary to reduce this early collapse and make the best use of the pavement material in the design of economic. In this paper, the control on the properties of binder layer ...
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Premature failure of flexible pavements has a large problem in many Iraqi roads with drastic increase in truck axle loads. It is necessary to reduce this early collapse and make the best use of the pavement material in the design of economic. In this paper, the control on the properties of binder layer at the expense of wearing layer to achieve better balance between the damage ratio compared to the most design life are adopted. The methodology is based on the damage analysis concept which is performed for both fatigue cracking and rutting on different pavement sections using KENLAYER program.
The investigated pavement components are thickness and elasticity modulus for binder layer and thickness of wearing layer. The results of pavement analysis showed that the design life increases with increasing the thickness of wearing layer when the thickness of binder layer increases more than (3.94 in) and it decreases when the thickness of binder layer increase less than (3.94 in). The fatigue damage ratio decreases with increasing the thickness of wearing layer when increasing the thickness of binder layer more than (3.94 in) and it increases with increasing the thickness of wearing layer when increasing the thickness of binder layer less than (3.94 in). The rutting damage ratio increases with increasing the thickness of binder layer and with increasing the thickness of wearing layer. Finally, the design life increases with decrease binder moduli and fatigue damage ratio increases with increasing the binder moduli and also the rutting damage ratio decreases with binder moduli (330000 psi).
