Journal of University of Babylon

The research deals with the effect internal sulfates (as gypsum) present in fine aggregate (sand) on the ‎mechanical properties of self-compacting concrete made using a local filler. A mix of self-compacting ‎concrete was designed according special specifications and trials. This mix was tested by various fresh ‎concrete workability tests as Slump-flow, T50cm, L-box, U-box, and V-funnel tests to evaluate the ‎passing ability, filling ability, stability and segregation resistance of the fresh mix. ‎
‎ The gypsum content (as SO3) was varied in sand as (0.4%, 1.0%, 1.5%, 2.5%, and 3.5%) by ‎wt. of sand which yield a total SO3 content in concrete as (3.77%, 4.74%, 5.55%, 7.15%, and 8.77%) ‎by wt. of cement respectively.‎
‎ The experimental results show that there is an Optimum Gypsum Content in fine aggregate ‎‎(SO3=1.0%) by wt. of fine aggregate which gives the highest results in compressive strength, splitting ‎tensile strength, flexural strength and Young\'s modulus of elasticity of SCC. As gypsum content ‎increases beyond this limit the above mechanical properties will be decreased remarkably and also ‎SCC reveals softer stiffness mechanical behavior.‎

This research is devoted to investigate the behavior and performance of RC beams subjected ‎to shear‏ ‏and strengthened with CFRP sheets. The experimental program consisted of eight tested ‎beams; two control beams, the first was without any shear reinforcement and the second was ‎reinforced by steel stirrups, five beams was strengthened by CFRP sheets and the eighth beam was ‎repaired after it had been loaded up to service load. The variables investigated in this work included ‎the CFRP amount, orientation, distribution and anchorage of the end of the CFRP sheets. All beams ‎had been tested as a simply supported span and‏ ‏subjected to two-point loading.‎
The experimental test results showed that the ultimate load capacity of the strengthened ‎beams ranged between 30% to 45% over the ultimate load capacity of the reference (unstrengthened) ‎beam. The ultimate load of repairing beam reached 96% of the ultimate load of similarly strengthened ‎beam. Drilling the flange of the RC beams to wrap the CFRP strips was the most effective and ‎significant factor for strengthening RC beams. ‎
The use of ANSYS computer program (version 9.0, 2004) to create the finite element model is ‎adopted. Interface element (CONTAC52) was used in the finite element model of RC beam that was ‎strengthened by U-wrap CFRP strips to simulate the bond between the CFRP strips and concrete ‎surface, while the strengthened RC beams by full wrap CFRP strips, full bond was assumed. The ‎comparison between the numerical and the experimental results asserted the validity of the numerical ‎analysis, the average difference of central deflection and ultimate load between experimental and ‎numerical results were 4.3% and 4.7% respectively for all the tested and analyzed beams.‎

The developed aluminum matrix composite (AMCs) is considered to be a promising material ‎for low and high temperature applications. Particles reinforced AMCs materials have high specific ‎strength and modulus of elasticity, together with excellent heat resistance. ‎
Silicon carbide particles reinforced aluminum matrix composite (AMCs) for hardness, impact ‎strength, and material toughness improvement were prepared. Stir-casting processing was optimized. ‎The hardness, impact strength, and material toughness were evaluated. Under stir-casting, the silicon ‎carbide particles were uniformly distributed in the aluminum and well bonded with aluminum matrix. ‎The hardness and material toughness were increased 1.84 and 2.16 times respectively at particles ‎weight fraction (10% ) that of the of the unreinforced aluminum based on the high hardness and ‎deformation resistance of the silicon carbide particles.‎

Desalination of brine by solar powered systems is a practical and promising technology for ‎producing potable water in the regions which suffers from water scarcity especially in arid areas. The ‎abundant solar radiation intensity along the year and the available brine resources are two favorable ‎conditions for using the desalination solar technology to produce the fresh water, even for domestic ‎use. Based on these conditions, two small-scale solar powered desalination systems, one with mirrors ‎as interior surface of the walls and the other without mirrors, have been constructed and operated. The ‎present study aims to improve the solar still performance, and to increase its productivity. So it is ‎necessary to evaluate some important parameters affecting the system productivity. The effect of ‎brine depth in the basin on the productivity was evaluated. In the same time, the effect of using ‎reflecting interior fasces (mirrors) and the adding blackened balls, with different materials, on the solar ‎desalination process in the stills were investigated. Different depths of brine (1.5, 3, 5 and 8cm) with ‎TDS of 2000-2050 ppm were tested under the climatic conditions of Kufa city. The obtained results ‎showed that the productivity of the still with reflecting faces was 22.9% higher than that of still without ‎reflecting sides, and that the decreased water depth and the adding blackened balls have a significant ‎effect on the increased still productivity, while the performance characteristics showed that the still ‎productivity was closely related to the incident solar radiation intensity.‎

‎ This 1nvestigation is conducted to study the effect of adding (SBR + limestone powder) to ‎concrete mix (1:1.5:3) (cement : Sand : gravel) with w/c = 0.5, and (SBR + Limestone powder) with ‎concentration of (10% + 2%), (15% + 2%) and (20% + 2% ) by volume of water and by weight of ‎cement consequently . compressive strength at ages (7, 28, 60) days was tested, also absorption and ‎splitting tensile strength were also measured.‎
Also ( SBR + limestone powder ) was added to cement mortar (1:2) (cement : sand) with w/c = ‎‎0.42, and (SBR + limestone powder) with concentration of (10% + 2%), (15% + 2%) and (20% + 2%) ‎by volume of water and by weight of cement consequently. Drying shrinkage cracking of this mortar ‎was tested . As well as SBR was used as bonding mortar layer between old and new concrete layers, the ‎compressive strength of bonded samples was tested.‎
‎ The results indicate that the use of (SBR + limestone powder) in a concentration of ( 10% + 2%) ‎and ( 15% + 2%) by volume of water and by weight of cement consequently cause slight increase in ‎compressive strength by about [ 3 % , 1.9 % and 2 %] for ages ( 7, 28 and 60) days respectively , ‎and by about [ 6.3 % , 5.2 % and 4 %] for ages ( 7,28 and 60) days respectively , but the addition of ‎‎(SBR + limestone powder) in concentration of ( 20 % +2 %) cause reduction in compressive strength by ‎about [ 10.6 % , 8.6 % and 9.5 %) for ages ( 7 , 28 and 60 ) days respectively , while the use of ( SBR ‎‎+ limestone powder ) in all concentration cause slight increase in splitting tensile strength , also it ‎reduces the absorption of concrete
‎ Also , it was found that the addition of ( SBR + limestone powder ) to cement mortar retards the ‎occurrence of shrinkage cracks . ‎
‎ The use of SBR as bonding layer showed increasing in compressive strength of the bonded ‎samples compared with samples having old and new concrete without bond layer.‎

A mixed copper sulphate/ H2SO4 electrolyte was operated in a galvanostatic mode, where hydrogen ‎ions produced at the anode compartment due to water dissociation on anode then transferred with copper ions ‎across the diaphragm of electrochemical reactor into cathode compartment. Series of runs were made using an ‎electrolyte of concentration 0.2M CuSO4/1.0M H2SO4 and 0.4M CuSO4/1.0M H2SO4. The cell was operated at ‎different current densities (0.03, 0.06 and 0.12A/cm2).Both anolyte and catholyte copper and acid ‎concentrations were measured by atomic absorption technique. The concentration of copper ions Cu+2 in the ‎catholyte was found to be decreased with time due to copper deposition and its concentration in the anolyte ‎also decreased due to the transfer of Cu+2 across the diaphragm from the anode compartment to the cathode ‎compartment but with a less gradient. As the electrolysis proceeds, the hydrogen evolution increases and the ‎copper deposition efficiency decreases. Predicted copper deposition at constant current density and higher ‎initial copper ion concentration gave satisfactory agreement with experimental data. ‎

The aim of this paper is construction a mathematical model in computer program. The model ‎includes modeling of air pollution from multiple point (stacks) sources as a method for estimating short ‎‎–term dispersion of pollutants using the Gaussian steady – state equation. This analytical model can be ‎used for estimating air quality ground level concentrations (GLCs) of relatively stable pollutants for ‎averaging time one hour in urban areas. Two systems of PGT (Pasquill-Gifford-Turner) equations and ‎ASME (American Society for Mechanical Engineers) equations are used in the model for estimating the ‎dispersion coefficients. Also, Briggs equations are applied for estimating the plume rise.‎
‎ In spite of the basic simplicity of the plume concept, the superposition of the concentrations ‎of many plumes from multiple point sources in an urban situation, and for a wide variety of ‎meteorological and plume dispersion conditions, leads to complexities, which are taken into ‎consideration in detail at the stage of model development. It therefore seems desirable to state the ‎formal structure as unambiguously as possible. ‎
The model was examined for checking its validity to predict the GLCs of gaseous pollutants ‎emitted from a multiple point source of industrial activities. The predicted concentrations were in good ‎agreement with the measured concentrations especially when ASME equations are used for estimating ‎dispersion coefficients. ‎

In the recent years, the water amount of Euphrates River decrease to the low levels which has ‎led to increase the concentration of pollutants in it. In the city of Karbala, potable water is treated by ‎purification plants that involves coagulation, flocculation, sedimentation, filtration ,and sterilization units ‎whereupon pumping to ground tanks and then to a network or directly to the network. In process of ‎coagulation alum substance is commonly used as coagulant in water treatment plant in Iraq. In the ‎present study the alum was evaluated in water purification process with increase in the pollutants ‎concentration using the jar test for samples taken from Al-Husseiniyia river. It was found that high ‎removal ratios of turbidity reached to 96% by optimum dose amount of 10 mg/L, and the pH value of 7 ‎with the optimum speed and time of flocculation 25 revolution per minute and 20 minutes respectively. ‎The study was done to show the effect of removing turbidity in the optimum condition on the improving ‎of the some physicals and chemicals water properties such as reducing the concentration of total ‎dissolved solids, electrical conductivity, calcium and magnesium hardness. It was found that optimum ‎alum dosage (remove turbidity in optimum conditions) does not reduce the concentration of total ‎dissolved solids or electrical conductivity ( ratio of removal non-existent), but their effect on the removal ‎of calcium and magnesium hardness levels is very low.‎

‎ The reliability is defined as the probability that a system (item) will perform a specified function ‎under specified operational and environment condition, at specified time. The assessment of reliability ‎benefits the interconnected operation which led to increasing interest in efficient reliability evaluation ‎methods, so any reliability analysis of system must be based on precisely defined concepts. ‎Markov method technique used to assess time based reliability, which are very important data to the ‎engineers and designers for designing and developing any system to ensure that the system will operate ‎satisfactorily and does not loss its essential function when operating and applying on the AC power ‎supply of a nuclear reactor.‎

‎ A monopanel is a system building which consists of two thin ferrocement block-like faces and thick ‎layer of low strength, density and cost polystyrene foam insulation between them as a core. The simple ‎structure idealization of monopanel system is that the core provides shear transfer between the faces that ‎provide flexural resistance. Transverse trusses made of steel bars. In flexural bars connected by inclined ‎steel bar forming trusses shape making an angle equal to 45° with the longitudinal bars. The core material ‎can be made of low cost and low density. This core provides the excellent thermal and sound insulation ‎properties. ‎
The main object of this research is to present investigation on the behavior and load carrying ‎capacity of monopanel slabs. The experimental results show that effect of number of internal lacing, ‎number of layers of steel wire mesh in each of monopanel unit (one layer or two layer) . The experimental ‎nominal loads of monopanel slab specimens were compared with the results computed of the ACI-318 M-‎‎08 code and save to use ‎

An unsteady three dimension mathematical model is modified to be fitted for groundwater motion ‎media to recognize the validity of superposition theory in the non-homogeneous unsteady media in the ‎case of a given water table condition for unconfined aquifer. The results are evaluated using Darcy’s ‎Law and Theis Solution. After the model has been run for sufficient period, the resulted superimposed ‎drawdown of the numerical and theoretical solutions show a good matching up to 2968 days and show ‎acceptable variations beyond this period.‎

Water pollution for Shatt Al-Hilla river in Middle Euphrates region of Iraq (Babylon and Al-‎Diwaniya governorates) occurs in both rural and urban areas. In rural areas, drinking water from the ‎river is usually polluted by organic substances from upstream users who use water for agricultural ‎activities. To protect the water resources from pollution and deterioration which caused by natural ‎pollutants or human activities, an environmental database was constructed and applied. To evaluate ‎the pollutant concentrations, regression models were obtained by Data Fit Software program (version ‎‎8.0). A positive relation was obtained between total hardness, calcium, chloride, electrical conductivity, ‎magnesium, total dissolved solids, no. of days suspended, rising and storm dust, and negative relation ‎between total hardness and total alkalinity in Al-Hilla and Al-Hashimiya station. While calcium has ‎positive relation with total hardness, chloride, electrical conductivity, magnesium, total dissolved solids, ‎rising and storm dust and sulphate, and negative relation with temperature and discharge in Al-Hindya ‎Barrage station. In Al-Diwaniya station total dissolved solids has positive relation with electrical ‎conductivity, monthly rainfall totals, and no. of days of storm dust, and negative relation with ‎temperature, no. of days of rising and suspended dust, and hydrogen ion concentration.‎
The results were compared with the Iraqi and WHO standards for domestic and irrigation ‎purposes to determine pollution extend and suggest suitable solutions. A Comparison of the program ‎output data (TDS, Ca, TH) shows that these parameters in some stations are within the Iraqi and ‎WHO standards for domestic and irrigation purposes (i.e. TDS: Al-Diwaniya station), and (TH: in Al-‎Hill and Al-Hashimiya station). The results of the program are verified with data of year 2008 which is ‎not included in regression model. This verification shows a good agreement with coefficient of ‎determination ranged between "0.927 to 0.996".‎

‎ In this paper, we present a proposed reliable system for digital video compression. In this system we solved ‎the shift variant problem that produced because of the motion estimation and compensation associated with ‎using discrete wavelet transform(DWT) for the spatial domain compression. In this system the digital video is ‎entered to the two main processes, first is frame matching for motion or temporal redundancy detection, and the ‎second is the multi resolution DWT for band and spatial domains redundancy detection, then the result of the ‎decomposition is entered to a multi-level energy quantization before entering the entropy encoder. The proposed ‎system was executed based on conventional video compression system and proposed video compression ‎system. Many digital video movies with different motions (simple, complex) are used in testing the two ‎systems, the results of compression ratio, resolution of decompressed video, and required processing time are ‎compared. All the programs and graphics are executed using MATLAB version R2008a. ‎

In this study, time series analysis is applied to records of mean inflow to Haditha reservoir in ‎the west of Iraq for the period from water year 1988/1989 to the water year 2007/2008. This method ‎involves decomposition of the historical series into trend, seasonality and residual components. Split-‎Sample method is used to test the homogeneity of the series, and it is found homogenous .Box-Cox ‎transformation method is used to transform the series to normal distribution. Removal of periodicity from ‎series is done by the nonparametric method. ‎
Two stochastic known as ARMA models are fitted to this series. These are AR (1) and AR (2) ‎models. The unconditional sum of squares method is used to estimate the parameters of the models and to ‎compute the sum of squared errors for each of the fitted model. It is found that the model which ‎corresponds to the minimum sum of squared errors is the AR (1) model with autoregressive average ‎parameters Ф =0.817.The adequacy of this model is checked by the diagnostic checking. Forecasts of ‎monthly inflow for the period from October, 2008, to September, 2012 are found.‎

The stability of many soil foundations which are constructed on gypseous soils may depend ‎upon rate of dissolution caused by water seeping through this type of soil. Aggressive degree of water ‎for Kerbalaa gypseous soil with high gypsum content of (27%) can be assessed on basis of the relation ‎which was established by authors and collaborators to define the rate of gypsum dissolution ‎constant(K).‎
The laboratory model tests were achieved by preparing recompacted soil samples at field unit ‎weight (13.51 kN/m3) and susceptible to four values of solutions flow velocities of distilled water and ‎‎(calcium sulphate , sodium chloride )salts .‎
‎ The results showed that the gypsum solubility enhancement is a consequence of increasing ‎flow rate of solutions and sodium chloride presence, thus the dissolution rate constant K(m/sec) values ‎were ranged from (1.36-4.2)*10-5 for sodium chloride solution,(1.14-3.14)*10-5 for calcium sulphate ‎solution and(1.24-3.59)*10-5for distilled water for flow velocity ranging between (0.0093-0.0266) ‎‎(m/sec) .‎

‎ The goal of this paper is to develop a nonlinear observer-based control strategy for a jacketed continuous ‎stirred tank reactor (CSTR). The dynamic behavior and control of CSTR has been developed where the ‎dynamic and control system based on basic mass balance has been carried out.‎
‎ The control behavior of CSTR is studied using different control strategies; conventional feedback control ‎‎(PI and PID), cascade control and fuzzy-logic control (FLC).‎
‎ The FLC can be chosen as the best method for controlling the CSTR process and it is clear that the auxiliary ‎variable enables the controller to yield better control performance for highly nonlinear processes, as compared ‎with feedback and cascade controllers. ‎
‎ MATLAB program is used as a tool of solution for all cases mentioned in this work.‎

The search used waste tire fiber(W.T.F.) rubber in Concrete mixtures production , and study the ‎effect of(W.T.F.) on Concretes' behavior, which partly helps in solving environmentalism problem of ‎due to riddance from waste tire rubber. different ratios ( 15%, 25% ,50%) of (W.T.F.) rubber as a ‎substitute for mine gravels as a coarse aggregate, in three Concrete mixtures, while the fourth mixture ‎was without (W.T.F.) ,used natural gravels as a coarse aggregate, taken as a referential mixture. The 7 ‎and 28 days ages lab. tested resistance (compression, tensile, flexure strength, water Absorption and ‎density ) tests for the above mentioned mixtures which shows the increasing in replacing volume ration ‎of gravels with (W.T.F.) in Concrete mixture result in decrease in compression, tensile, flexure strength, ‎dry and wet density . while increasing in water absorption , compared with referential mixture gave ‎‎(without W.T.F.).The (W.T.F.) Concrete with ( 15%, 25% ,50%) Rubber giving compression strength ‎‎(84%, 70% , 46% ) consequently . compared with given referential mixture in 28 day age, but gives ‎decrease in dry density with ratio (6% , 10% , 25% ) consequently .relative to referential mixture , and ‎increasing in water Absorption ( 55% , 210% , 350% ) consequently in 28 day age . ‎

This investigation was managed on the request of general company of textile industry Babylon ‎‎– Iraq . Thus three sampling sites were selected ,water drinking that enter to the textile , water softing ‎and boils. ‎
‎ The study included qualitative evaluation of water from the study sites .Generally ,result ‎showed that the temperature ,total Hardness, Calcium Chlorides and Sulfates showing clear time ‎variation .The studied water always was on the alkaline of neutrality . ‎