Orhan Sabah Abdullah
Volume 10, Issue 1 , March 2017, Pages 1-10
Abstract
Experimental study has been done in this research to explain the influence of low cost fillers contents on the mechanical and physical properties of unsaturated polyester resin composite with different weight fraction. The effect of three particles; Baby powder particles including MgO, Fire extinguisher ...
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Experimental study has been done in this research to explain the influence of low cost fillers contents on the mechanical and physical properties of unsaturated polyester resin composite with different weight fraction. The effect of three particles; Baby powder particles including MgO, Fire extinguisher particles including CaCO3 and chalk particles including SiO2 with weight fraction of (5%, 10%, 15%)Wf% added to polyester matrix on the wear rate under dry sliding conditions, hardness, thermal conductivity, and water absorption has been investigated. The wear rate was measured according to ASTM G99-05 standard with pin on disc machine, hardness measured according to ASTM D-2240 Shore D hardness test, Lee's disc technique used to measure thermal conductivity, while water absorption measured according to ASTM D 570 standard. The results shows that the addition of fillers leads to increasing the wear resistance, hardness and water absorption and decrease the thermal conductivity with the increasing in reinforcement material weight fraction. while, the wear resistance decreasing with increase in applied load. The results appeared that the addition of particles to polyester resin leads to increase in all the mechanical and physical properties tested in this research better than polyester specimen only and MgO-polyester composite given the best wear resistance.
Ahmed Sagban Saadoon; Hawraa Sami Malik
Volume 10, Issue 1 , March 2017, Pages 11-25
Abstract
Artificial neural networks (ANN) were used in this study to predict ultimate load of simply supported concrete beams reinforced with FRP bars under four point loading. A proposed neural model was used to predict the ultimate load of these beams. A total number of (199) beams (samples) were collected ...
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Artificial neural networks (ANN) were used in this study to predict ultimate load of simply supported concrete beams reinforced with FRP bars under four point loading. A proposed neural model was used to predict the ultimate load of these beams. A total number of (199) beams (samples) were collected as data set and it was decided to use eight input variables, representing the dimensions of beams and properties of concrete and FRP bars, while the output variable was only the ultimate load of these beams. It was found that the use of 11 and 10 nodes in the two hidden layers was very efficient for predicting the ultimate load. The obtained results were compared with available experimental results and with the ACI 440.1R specifications. The proposed neural model gave very good predictions and more accurate results than the ACI 440.1R approach. The overall average error, in the value of the predicted ultimate load, was 3.6% and 21.7% for the proposed neural model and the ACI 440.1R approach, respectively.
Khamail Abdul-Mahdi Mosheer
Volume 10, Issue 1 , March 2017, Pages 26-35
Abstract
In the present paper, experimental investigations were used to study the effect of the addition conductive screws on the behavior of reinforced concrete columns and beams. Screws with 25.4mm (1 inch) length were used. These screws were made of iron coated with Zinc-Aluminium alloy (called Al-Clad), which ...
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In the present paper, experimental investigations were used to study the effect of the addition conductive screws on the behavior of reinforced concrete columns and beams. Screws with 25.4mm (1 inch) length were used. These screws were made of iron coated with Zinc-Aluminium alloy (called Al-Clad), which is resistant to corrosion and rust. The volume fractions of the conductive screws were 0%, 0.5%, 1%, and 1.5% by volume of concrete mix with water/cement ratio equal to 0.55. The results show that the use of the conductive screws enhanced the strength. The strength in tested beams was increased by 15.78%, 44.73%, and 76.31% for 0.5%, 1%, and 1.5% screws content respectively compared to the reference beam with no screws. The same trend was observed with the columns results, where the strength was increased by 12.44%, 26.79%, and 50.71% for 0.5%, 1%, and 1.5% screws content respectively compared to the reference column with no screws.
Saleh Issa Khassaf; Fatima Mohsen kizar; Eng. Firas Fadhil Hassan
Volume 10, Issue 1 , March 2017, Pages 36-53
Abstract
This study is concerned with assessing suitability of groundwater in selected areas of Najaf governorate, Iraq, for multiple uses ( human drinking , animal drinking , industrial , agricultural and irrigation). Water samples were taken from 29 wells over eleven months (January - December 2014); these ...
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This study is concerned with assessing suitability of groundwater in selected areas of Najaf governorate, Iraq, for multiple uses ( human drinking , animal drinking , industrial , agricultural and irrigation). Water samples were taken from 29 wells over eleven months (January - December 2014); these samples were chemically and microbiologically analyzed using eleven parameters: Electrical Conductivity ( EC ), Total Dissolved Solid ( TDS ), pH values, Calcium (Ca+2 ), Magnesium ( Mg+2 ), Sodium (Na+ ), Chloride ( Cl - ), Sulphate ( SO4 -2), Nitrate (NO3-), Total Hardness ( T.H ) and Total Coliform Bacteria ( T.C ). Sodium Adsorption Ratio ( SAR) was also calculated to be compared with standards. It is found that the groundwater of the study area is not suitable for human drinking and industrial purpose (except groundwater of one well which was suitable for chemical industry and refinery ) because of high concentration of chemical variables, but it was suitable for animal consumption and irrigation vegetables which resist moderate and high concentrations of EC in water, a salinity problem was expected based on Todd and American Salts Laboratory classifications, there were no harmful effects from sodium indicators on plants, most of water samples were within the classes poor and very poor for irrigation use according to Richard classification, and chloride toxicity problem was expected because 69 % of groundwater samples can cause severe problems.
Mohamed F. Al-Dawody; Naseer H. Hamza
Volume 10, Issue 1 , March 2017, Pages 54-71
Abstract
The use of gas turbine is increasing day by day for producing electricity and for various industrial applications. In this work a new approach of study for the effect of different cycle arrangements on the performance of simple gas turbine has been investigated. The new cycle arrangements include: reheat ...
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The use of gas turbine is increasing day by day for producing electricity and for various industrial applications. In this work a new approach of study for the effect of different cycle arrangements on the performance of simple gas turbine has been investigated. The new cycle arrangements include: reheat with heat exchanger, reheat with water injection, heat exchanger with water injection and reheat together with heat exchanger and water injection. All these arrangements are compared to the performance of gas turbine cycle with no modifications. A Matlab code was written to calculate the combustion characteristics and major performance parameters such as net work, fuel/air ratio, specific fuel consumption, and thermal efficiency ….etc. It’s observed that using reheat in addition to heat exchanger with water injection gives higher thermal efficiency, maximum increment was 28.6% in compare with normal basic cycle and lower fuel consumption, maximum reduction was 22.2 in compare with normal basic cycle.
Baha Sami Mahdi; Hussain Abdulaziz Abrahem; Enaam Obeid Hassoun
Volume 10, Issue 1 , March 2017, Pages 72-80
Abstract
This work includes an experimental procedure to studying the behavior of flow of dissimilar metal in the friction stir welding process to joining Aluminum to Copper. And investigating the effect of square and cylindrical probe tool shape on the joint metal flow behavior. The findings demonstrate that ...
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This work includes an experimental procedure to studying the behavior of flow of dissimilar metal in the friction stir welding process to joining Aluminum to Copper. And investigating the effect of square and cylindrical probe tool shape on the joint metal flow behavior. The findings demonstrate that the square probe shows better joint properties than the cylindrical probe, and that the most stirring effect happens on the aluminum side with fine copper rich particles embedded in aluminum matrix. There are two recognized regions, the first region represent the effect shoulder and the second represents the probe stirs effect. The stir effect in the Cooper side is less than the stir effect in the Aluminum side with a laminate form of rich Copper to Aluminum. These laminates are the source of the fine particles founded in aluminum side upper and lower regions.
Rana Afif Anaee; Aseel Mahmmod Abdulah; Sura Salim Ahmed
Volume 10, Issue 1 , March 2017, Pages 81-86
Abstract
This work involves using Saccharum short fibers as reinforcement for unsaturated polyester before and after chemical treatment for fibers. The chemical treatment was done in NaOH solution with different concentrations include 0.125, 0.25, 0.375, 0.5 and 0.625 M at room temperature. The prepared composites ...
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This work involves using Saccharum short fibers as reinforcement for unsaturated polyester before and after chemical treatment for fibers. The chemical treatment was done in NaOH solution with different concentrations include 0.125, 0.25, 0.375, 0.5 and 0.625 M at room temperature. The prepared composites were characterized by FTIR spectra to confirm the improvement of interaction between reinforcement and matrix through the reduction in hydrophilic groups. The investigation by FTIR showed the improving of the adhesion between reinforcement and polyester as matrix because of reduction of absorption the water. The impact toughness was tested for polymeric composites and the results indicated that the chemical treatment with NaOH led to increasing impact energy due to increasing bonding force between treated Saccharum fibers and matrix.
Emad Abdula Khazal; Khalid Baker Saleem
Volume 10, Issue 1 , March 2017, Pages 87-102
Abstract
This paper presents a two-dimensional numerical analysis to study the laminar heat transfer and flow characteristics of CuO–water nanofluids through a tube at constant heat flux boundary condition at tube wall. Based on the single-phase approach, the effects of different parameters such as nanoparticle ...
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This paper presents a two-dimensional numerical analysis to study the laminar heat transfer and flow characteristics of CuO–water nanofluids through a tube at constant heat flux boundary condition at tube wall. Based on the single-phase approach, the effects of different parameters such as nanoparticle volume concentration (1% - 5%), and Reynolds number (500 - 2100) for various axial locations of tube with CuO–water nanofluids as working media were discussed in detail. The finite volume method and SIMPLE algorithm are utilized to solve the governing equations numerically. The numerical results shows that with enhancing Reynolds numbers, local Nusselt number increases. The variations of the local Nusselt number relative to volume concentrations are not uniform. According to the results, an equation was obtained for Nusselt number predicted data using the dimensionless numbers. The relation between local Nusselt number and Re number also compared for other previous work. There are agreement in results and found the maximum difference between results reach to be 6.3% approximately which validate the current computational model.
Hyder H. Balla
Volume 10, Issue 1 , March 2017, Pages 103-119
Abstract
This study employed the use of experimental data of film cooling effectiveness using corrugation film cooling hole. Effects of blowing ratio in conjunction with twisted angles (0°, 90°, 180°, 270° and 360°) were also investigated. Recently, the utilization a vortices in enhancing ...
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This study employed the use of experimental data of film cooling effectiveness using corrugation film cooling hole. Effects of blowing ratio in conjunction with twisted angles (0°, 90°, 180°, 270° and 360°) were also investigated. Recently, the utilization a vortices in enhancing thermal transfers is becoming increasingly attractive as a result of its dual advantages including its surfaces that are extended, turbulent twisted holes as well as coarseness. Results of enhancement in the effectiveness ranging from 1.2–2.2 times those from conventional smooth film cooling holes with significantly increased coefficient of thermal transfer ranging from 1.50 to 2.70 times those of the conventional film cooling holes with smooth surfaces. Both the numerical and the experimental analysis of the effectiveness of film cooling were authenticated by results from pervious related studies. The authors found and concluded thus, effectiveness of twisted film cooling holes at rectangular spiral corrugation shape was higher in comparison to holes with cylindrical shape. The effectiveness of film cooling for the twisted holes were observed to be hugely influenced by inclination angle between the main and the secondary holes of the film cooling hole antivortex.
