Khitam Abdulhussein Saeed
Volume 9, Issue 1 , March 2016, Pages 1-10
Abstract
Hydraulic properties of sandy clay soil are very important for filtration, seepage and irrigation; so set of experiments were carried out for different samples of sandy clay in Baghdad. Measurements include bulk density, particle size distribution, clay percentage and hydraulic conductivity using constant ...
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Hydraulic properties of sandy clay soil are very important for filtration, seepage and irrigation; so set of experiments were carried out for different samples of sandy clay in Baghdad. Measurements include bulk density, particle size distribution, clay percentage and hydraulic conductivity using constant head system. The aims of this study were to estimate equivalent saturated hydraulic conductivity (Ks) for different clay percentages and predict porosity of sandy clay as function of clay percentage and porosity of sand and clay. Nine samples of sandy clay soil have been tested in a hydraulic and soil laboratory (Mustansiriya University). Semi-empirical model was correlated to evaluate saturated hydraulic conductivity from clay percentage and results were compared with five empirical models selected from published literature were also used to predict Ks. These empirical models were (Puckett ,1985) , (Ryjov and Sudoplatov,1990), ( Dane ,1992), (Dheyaa ,2001)and (Shevnin.et al, 2006).
Hakim S. M. Al-Kurayshi; Dhurgham Abdul Jaleel Resool
Volume 9, Issue 1 , March 2016, Pages 11-22
Abstract
Horizontal Shear transfers through interfaces between two materials need to be studied accurately especially when the interface separates two different materials. In this study the two materials are concrete and bricks. This interaction can be formed in the regions where concrete is rested on brick walls ...
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Horizontal Shear transfers through interfaces between two materials need to be studied accurately especially when the interface separates two different materials. In this study the two materials are concrete and bricks. This interaction can be formed in the regions where concrete is rested on brick walls in so many positions in construction. The study focuses on an experimental work through a series of push-off tests for ( concrete to bricks, cement mortar to bricks ) taking into consideration that the shear connectors are steel bars. Throughout push–off tests and due to the applied horizontal forces as slip had been attained. This forces and slips are recorded and graphically drawn. A statistical regression was made to find the most representative formula of the mechanism of shear transfer between concrete with bricks and between cement mortar with bricks. The predominant factor in shear transfer between concrete and bricks is the amount of shear connectors because as number of dowel bars increases the shear strength increases. The value of force recorded at 2mm slip for concrete to concrete was around three to four times that for concrete to bricks in existence of steel bars or steel dowels. This means that concrete to bricks is weaker than that between two concretes.
Dheyaa Wajid Abud; Mohammed Ibrahem Basheer Al-Ubaidy; Yousef A. Jassim
Volume 9, Issue 1 , March 2016, Pages 23-35
Abstract
Landfill bioreactor is a modified technique comparing with the conventional landfill processes due to its ability to reduce time for decomposition and enhancing the biogas generation. The basic goal of this paper is to investigate the performance of a three lab-scale bioreactors under anaerobic conditions. ...
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Landfill bioreactor is a modified technique comparing with the conventional landfill processes due to its ability to reduce time for decomposition and enhancing the biogas generation. The basic goal of this paper is to investigate the performance of a three lab-scale bioreactors under anaerobic conditions. Three types of reactors differ in its internal composition were experimented ,bentonite clay was used as a cover material. First reactor was filled with organic solid waste only; second reactor was filled with a mixture of organic solid waste, Lime and sawdust, while the third reactor was filled with mixture of solid waste and lime. Leachate characteristics traced includes pH, EC, TDS, TSS, Heavy metals (Cr, Fe, Mn, Zn, and Mo), Sulfate SO-24 and Phosphate PO-34.
Experiments were conducted from October 2014 to march 2015, Results shows a significant variation in removal efficiency for each reactor, heavy metals removal for the first reactor was (Mn 58.6%, Cr 13.4%, Mo 0%, Zn 27.2%, Fe 58.6%),and the second reactor removal efficiency was (Mn 77.2%, Cr 67.5%, Mo 69.19%, Zn 67.9%, Fe 56.7%), while for the third reactor was (Mn 30.1%, Cr 13.8%, Mo 18.48%, Zn 29.8%, Fe 70%). The results show that the solid waste, Lime and sawdust enhanced the removal of heavy metals in the 2nd reactor which gave best removal efficiency for heavy metals. While the lime addition in the 3rd reactor increase the removal efficiency of iron to 70%. It can be conclude that this modified landfill bioreactor enhance leachate characteristics and so enhancing the solid waste stabilization.
Afraa Hilal Kamel
Volume 9, Issue 1 , March 2016, Pages 36-46
Abstract
Artificial neural networks (ANN) were used to predict the viscosity of epoxy resin modified by natural waste material (pomegranate peel) powder. This waste material, which has a high pollution capacity for the environment, could be used as an improvement to the properties of a weaken material ...
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Artificial neural networks (ANN) were used to predict the viscosity of epoxy resin modified by natural waste material (pomegranate peel) powder. This waste material, which has a high pollution capacity for the environment, could be used as an improvement to the properties of a weaken material such as epoxy resin In reservoir engineering computations the viscosity parameter is a very important fluid property. The data is not either reliable or unavailable most of the time; It should be specified in the lab. Levenberg-Marquardt backpropagation of artificial neural network based model (ANNs) was evolved to predict the viscosity of modified pomegranate peel powder of epoxy resin. Three parameters affecting the viscosity of mixtures based on epoxy resin containing pomegranate peel powder and pure epoxy resin were studied. These are temperature, concentration of pomegranate peel, and shear rate. The viscosity as output was predicted by training the network. A network was built up and trained using experimental information. The effects of temperature (30-50 °C), concentration of pomegranate peel powder (0-3)wt% and shear rate (4.35-15.95 1/sec) on the epoxy resin were modeled by ANNs as well. The expected values were in excellent agreement with the measured ones, showing that the developed model is really accurate and has the great ability for predicting the viscosity. The linear regressions R2 0.9994 and 0. 9998 are the values of the ANN viscosity model for training and testing data set, respectively, 2.7175*10-4 and 1.2441*10-4 are the values of mean square error respectively.
Shakir Al-Busaltan; aly Al-Ani; Ola Al-Jawad
Volume 9, Issue 1 , March 2016, Pages 47-58
Abstract
The surface to volume ratio of concrete pavement is large, also, due to hot climate of Iraq, coating concrete pavement after casting is essential to ensure vital curing, consequently to obtain significant engineering properties. This research work reports the results of a study performed to evaluate ...
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The surface to volume ratio of concrete pavement is large, also, due to hot climate of Iraq, coating concrete pavement after casting is essential to ensure vital curing, consequently to obtain significant engineering properties. This research work reports the results of a study performed to evaluate the engineering properties of concrete coated with concrete surface coatings solutions; two types of coating were used representing co-polymer (Styrene-Butadiene Rubber, SBR) and by-product material (Residue Crude, RC). Different coating solutions were prepared from these solutions, individually and collectively; i.e. 100% SBR, 75% SBR+25% RC, 50% SBR+50% RC, 25%SBR+ 75%RC, and 100%RC. The engineering properties of the uncoated and coated concrete samples were evaluated by assessing compressive strength, flexure strength and hardness for concrete convenience for highway rigid pavement. The compressive strength was evaluated for the specimens at 7, 14, 28 and 90 days, where flexure and hardness were evaluated at 28days.
The results showed that the coated samples with both SBR and RC performed noticeably better in contrast with uncoated samples under air-dry conditions. Additionally, obvious differences in the performance of the collective solutions were recognized. From the results, however, local by-product materials have been proven as a significant coating materials suitable to enhance the concrete used for pavement purposes.
Besma M. Fahad; Hyman Jafar Meerza
Volume 9, Issue 1 , March 2016, Pages 59-72
Abstract
Modification or purification of potable water with the use of recycle waste glass reduces the drain on the natural resources of the raw materials, which is widely used in our daily life. However, the disposal of waste glass is not an easy matter, which is because glass is neither incinerated nor decomposed ...
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Modification or purification of potable water with the use of recycle waste glass reduces the drain on the natural resources of the raw materials, which is widely used in our daily life. However, the disposal of waste glass is not an easy matter, which is because glass is neither incinerated nor decomposed material.
In this study, ten samples of potable water were collected from ten regions in Baghdad capital city in order to investigate their physical and chemical properties. Chemical and physical properties of water were identified. Several parameters of water quality were analyzed including: turbidity, electrical conductivity, and acidity function (pH) and total suspended solids according to Iraqi standards.
The results of all water samples showed that the physical and chemical analysis tests were acceptable for drinking except the station of Madinat Alsadar. Using the waste glass to eliminate this problem, as low cost and inert material, was successful in potable water treatment. As a conclusion, the TSS was decreased after filtration process by waste glass especially for Althaalba and Alameria potable water which were disappeared (being zero).
Yahya K. At-Temimi
Volume 9, Issue 1 , March 2016, Pages 73-86
Abstract
The properties of groundwater in some wells digging on the border of Iraq with KSA along 400 km from Al-Nekheab at west to Al-Salman at south of Iraq were evaluated. Eleven wells were chosen as a case study depended on variable of water depth and stratum properties. Water samples were taken at two periods ...
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The properties of groundwater in some wells digging on the border of Iraq with KSA along 400 km from Al-Nekheab at west to Al-Salman at south of Iraq were evaluated. Eleven wells were chosen as a case study depended on variable of water depth and stratum properties. Water samples were taken at two periods the first one at summer and the other at winter reason. The chemical properties of these samples were compared with the standard limits to evaluate the quality of water for different uses. The main parameters used for evaluation process are negative and positive ions, total dissolve salt, electrical conductivity, and turbidity.
Finally, conclude the usages of water of investigated wells were un-permitted for drinking purposes except well No.10 unless treated by purifying process, but can be used for irrigation for soil which has high permeability and good drainage in addition to plant have high strength for salinity. In the other side all wells mostly used for livestock usages and poultry.
For industrial usages only well No.(10) can be used for industry of cement. While all wells can be used for building purposes except wells No. (1, 2, 7, 11).
Farooq Hassan Ali
Volume 9, Issue 1 , March 2016, Pages 87-105
Abstract
In this work, a numerical simulation of natural convection in an oblique enclosure filled with silver-water nanofluid is obtained for different values of Rayleigh numbers, volume fraction and inclination angle of sloping walls. The considered oblique enclosure with left and right side walls are maintained ...
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In this work, a numerical simulation of natural convection in an oblique enclosure filled with silver-water nanofluid is obtained for different values of Rayleigh numbers, volume fraction and inclination angle of sloping walls. The considered oblique enclosure with left and right side walls are maintained at constant cold temperature (Tc). The horizontal top wall of enclosure is kept insulated, but the bottom is maintained at constant hot temperature (Th). The present work is utilized to obtain results in the range of Rayleigh number (103-106) , volume fraction of nanofluid varied from (0-0.2) and inclination angle of side walls are (-60o, -30o, 0o, 30o, 60o). The Prandtle number is 6.0. The governing equations in the two-dimensional are solved numerically by using finite-difference technique.
Comparisons with other works are performed and the results are found to be in good agreement. The obtained results are shown in the form of stream function, isothermal lines and average Nusselt numbers. It observed from results that acute shaping wall and Ag-nanoparticles with high concentration are effective to enhance the rate of heat transfer, also; the average Nusselt number for all range of inclination angle increases with increase in the Rayleigh number and the solid volume fraction of the Nanofluid.
Hakim S. M. Al-Kurayshi
Volume 9, Issue 1 , March 2016, Pages 106-118
Abstract
Shear is transferred through interface between two concrete members by two mechanisms either by aggregate interlock or by dowel action or by both in the same time. This media is very complex and there are so many variables affecting shear transfer like surface shape and final treatment of the concrete ...
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Shear is transferred through interface between two concrete members by two mechanisms either by aggregate interlock or by dowel action or by both in the same time. This media is very complex and there are so many variables affecting shear transfer like surface shape and final treatment of the concrete surfaces. Histories of the previous researchers are mentioned in this paper to find out the applicable results of their equations. It is noticed that most of them depend on only clamping stress due to dowel action while others used besides that the type of concrete used namely its compressive strength. A mathematical statistical trials are made in this paper to find out the most accurate and suitable equation which simulates the action happened in this media. An equation of six parameter polynomial is obtained containing clamping stress and compressive strength of concrete. Assumed values of the mentioned variables are used in this equation to find out the horizontal shear strength. The deviation recorded is about 4% which is an acceptable one.
Haitham AL-THAIRY
Volume 9, Issue 1 , March 2016, Pages 119-134
Abstract
This paper presents an experimental study on the effect of transverse reinforcement on the axial compressive strength of rectangular and circular cross sectional shape reinforced concrete (RC) columns under axial compression. Twenty specimens of small scale RC columns specimens were considered in the ...
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This paper presents an experimental study on the effect of transverse reinforcement on the axial compressive strength of rectangular and circular cross sectional shape reinforced concrete (RC) columns under axial compression. Twenty specimens of small scale RC columns specimens were considered in the experimental tests. Ten of the columns specimens have a square cross sectional shape with dimensions of (150×150) mm and the other ten specimens have a circular cross sectional shape with a diameter of 150mm. For each cross sectional shape, the columns are classified into two groups of five columns: the first group contains short columns according to ACI-Code requirements (ACI318, 2011) and the other group consists of long columns. Each group uses same longitudinal reinforcement ratio but with five different transverse reinforcement ratios represented as a volumetric ratio of the transverse reinforcement. An experimental test has been conducted to determine the maximum axial compressive load at which each concrete column would fail. The experimental test results have shown that increasing of the volumetric ratio of the transverse reinforcement leads to a considerable increase of the axial load resistance of the column for both rectangular and circular columns and for both cases of long and short columns. The study has also showed that using equations suggested by the ACI-Code to determine the axial compressive strength of RC columns with tie reinforcement that are spaced at distances exceed that suggested by the code, gives over- estimated predictions of the column axial resistance which may results unsafe design.
