Journal of University of Babylon

‎ This paper presents a controlling strategy based on the addition of three reactive T-section circuitries ‎connected in series with a star-connected 3-phase load impedance. The left hand side branch of each T-‎section is a pure inductance having a constant reactance of +jX, while the right hand side impedance is a ‎pure capacitance having a constant reactance of –jX. The middle branch is a susceptance B, which is ‎composed of a switched capacitor bank in shunt with a switched inductor and is connected to the star ‎point of the load impedance. This susceptance is controllable in the range of ±Bmax. The system is ‎capable of maintaining the three-phase load voltage at its rated value even though the power system ‎voltage is varying within the range of 80% to 120% of its rated value. In addition, the system is equipped ‎with voltage balancing technique and is almost free from harmonics. The whole system was designed and ‎implemented using PSpice Program. ‎

‎ The aim of water quality assessment and monitoring program is to provide timely and accurate ‎water quality data to various clients within the Department of Ecology and elsewhere. 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 natural sources such as rivers ‎and streams 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). The results were compared with the Iraqi and WHO standards for domestic and irrigation ‎purposes to determine pollution extend and suggest suitable solutions. 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".‎

Unsaturated polyester resins are widely used in industry by virtue of combinations of ‎favourable characteristics including good mechanical and physical properties, ease of processing and ‎low cost. However, these resins suffer from the disadvantage of brittleness.‎
In this work, polymeric composites were prepared from unsaturated polyester resin reinforced ‎with different weight fractions of chopped alumina fibers (6%, 12%, and 18%).The following ‎properties were studied: hardness, impact strength, and material toughness.‎
Experimental data showed that incorporation of alumina fiber reinforcements in the ‎extremely brittle unsaturated polyester resin resulted in improvement material properties. Hardness, ‎impact strength, and material toughness increased by 151%, 521% and 474% respectively at weight ‎fraction of chopped alumina fibers (18%). The role of fiber reinforcing on the materials properties was ‎discussed in terms of fibers nature and content.‎

‎ This research is concerned with a new type of ferrocement of polystyrene concrete, which has several ‎advantages compared to ordinary reinforced concrete plates, such as lower density, abrasion resistance, ‎compressive and flexural strength. The experimental program consisted of casting and testing of 24 ‎ferrocement plates. The dimensions of the ferrocement plates were (600×300×40) mm in (length × width × ‎height) respectively. The effect of various factors such as mix proportions of cement to polystyrene (C:P) ‎ratio has been investigated, both by destructive and non-destructive methods. The experimental results of ‎the compressive strength of mortar mix 1:1 and using (1:1, 1:3 and 1:5) the cement to polystyrene (C:P) ‎ratio by volume were increased by (6.0, 9.9 and 12.2 )% and (11.7, 18.1 and 20.6)% at (60, 90) days age ‎respectively, while for mortar mix 1:2 were increased by (6.3, 10.2 and 10.5 )% and (12.6, 16.5 and 19.0)% ‎at (60, 90) days age respectively. On the other hand, increasing (C:P) ratio was found to decrease the ‎stiffness constant and dynamic modulus of elasticity of polystyrene concrete plates. Also, the analysis of ‎the experimental results showed that the dynamic properties such as, dynamic modulus of elasticity and ‎stiffness constant increased linearly as the volume fraction of steel wire mesh or specific surface area was ‎increased. ‎

In this paper, numerical simulations are carried out for natural convection induced by a temperature ‎difference between a heated circular cylinder and a cold outer square enclosure. A two dimensional ‎Navier-Stokes equation is solved by using finite volume discretization with SIMPLE algorithm in non-‎orthogonal body-fitted coordinate system. Detailed flow and heat transfer features for different Rayleigh ‎numbers varying over the range 103-106 are reported. The study goes further to investigate the effect of ‎the inner cylinder location on the heat transfer and fluid flow. The location of the inner circular cylinder is ‎changed horizontally along the center-line of square enclosure with δ (-0.25L to 0.25L). The size, number ‎and formation of the vortices and shape of thermal plume strongly depend on the Rayleigh number and ‎the position of the inner circular cylinder. Overall heat transfer also changes for different position of the ‎inner circular cylinder. The results showed a good agreement with another published results.‎

In the present study ,two procedures of capacity-yield are applied to estimate the reliability of ‎Dokan reservoir. These procedures are the probability matrix(Gould) procedure, and the behavior analysis. ‎Vulnerability, and resilience, are also calculated in the last procedure . The results of this study indicate ‎that to obtain reliability of 95% , the yield is approximately 83% of mean monthly flow which ‎corresponds to a vulnerability of 426×106 m3 and a resilience of 9 month. However, in order to decrease ‎vulnerability and resilience yield must be decreased.‎

In this research the dust deposits quantity in the Babylon governorate during year 2008 were ‎studied and compared with WHO standards and other local and global studies. ‎
In order to make a reasonable estimation of dust deposits quantities in the Babylon region; ‎long term data of dust depositions in this region was needed. Thus, dust deposits in Babylon ‎governorate during year 2008 were measured by using standard dust collecting cylinder device. ‎Measuring process was carried out in six monitoring stations selected randomly in the governorate. ‎These stations where located in Al-Musaibe city (Residential Station), Al-Mahaweel city (Residential ‎Station), Al-Hashimiyah city (Residential Station), Al-Moharibeen quarter (Residential Station), Al-‎Sena'ay quarter (Industrial Station), and Ananeh village (Agricultural Station). Dust from each station ‎was monthly weighted for year 2008. ‎
The results of this research showed increasing in dust deposits quantities, where the annual ‎average of dust deposits during year 2008 was (32.9 g/m2/month) but the World Health Organization ‎‎(WHO) recommended that dust deposits should not exceeds (9 g/m2/month). That is mean the average ‎of dust deposit in Iraq is about four times and half greater than the allowable limits.‎
As will as the results showed that the maximum dust deposits was (99.4 g/m2/month) in the ‎Al-Sena'ay Quarter during March, while the minimum concentration was (6.1 g/m2/month) took place ‎during October in Ananeh village.‎

The research study is about the enhancement of Data transmission Protection system. It gives support to ‎integrity of data and information security, message non-repudiation, and key management scheme of the ‎conventional classical producing data ciphering system. The uses of different forms of data Encryption ‎have thus been a common approach to data security. The main aim of this work is to model and simulation ‎a proposed hybrid structure of data Encryption system based on 2-Dimentions Discrete Wavelet Transform ‎‎2D-DWT and Phase matrix as permutation 2-Dimentions Fast Fourier Transform 2D-FFT. The design of ‎Encryption system consist a combination of using 2D-FFT to the 2D data signal then enters the 2D ‎frequency spectrum to the permutation by phase matrix and the output to inverse 2D-IDWT. All these ‎combination parts work as a hybrid Encryption structure. This processes achieved in transmitter will be used ‎in an inverted structure in Decryption part in receiver. The Encryption and Decryption parts are used with ‎Orthogonal Frequency Division Multiplexing OFDM to consist the proposed system. the proposed system ‎was examined by transmitting over one million random bits under different channel types. The simulation ‎results show that the system augments the attack-resistant potential and decreases the mistaken rate BER. ‎The proposed Encryption OFDM system gave a significant improvement in the BER performance in ‎comparison with the conventional OFDM.‎

This paper presents an investigation of contact surface interface, which is of strong interest for wear ‎applications. The prediction of the wear depth in contact surfaces is thus a challenging task. The effect of ‎the asperities height (0.045, 0.055, 0.065, and 0.07 )mm, the applied forces and the shape of the contact ‎surfaces on the wear depth and contact pressure are investigated by finite element method via ANSYS ‎software. Wear simulation approach based on Archard’s model was proposed, in which ANSYS was used ‎to simulate the progressive accumulation of wear between contact surfaces. Results showed that the ‎wear behavior can be simulated with the series of discrete models and the method proposed can be ‎widely used to predict wear problems for engineering. Two cases are studied, the first one is for ‎rectangular contact surfaces and the other for circle- rectangle contact surfaces with different height of ‎asperities. It was also concluded that the increased of contact’s time caused the wear depth for different ‎asperities increased and vice versa for contact pressure. ‎

Benzene is the most toxic of the soluble components of gasoline. It is more mobile than the ‎other aromatic hydrocarbons. Thus, benzene concentrations often determine the need for remedial ‎action in contaminated sites. This paper aims to study the fate of dissolution and transport of benzene in ‎saturated porous media and dissolution rate computations. A three dimensional bench-scale aquifer has ‎been designed and constructed for this purpose. The experiments were conducted under unidirectional ‎flow at different water flow velocities. The results characterized the dissolution behavior and distribution ‎of an entrapped nonaqueous phase benzene source in a three dimensional aquifer model. The time ‎invariant average mass transfer coefficient is determined at each interstitial velocity. The values of this ‎coefficient ranged from 0.016 to 0.061 cm/hr. It is increased proportionally with velocity toward a ‎limiting value. The results showed that the concentration of dissolved benzene reduces as the distance ‎increased in x and/or z direction from the source of pollution. In most cases the concentration values ‎were not stable with time at different values of the interstitial velocity. The dissolution rate of benzene in ‎the aquifer is computed by two methods. The first method is taken from the effluent concentration and ‎flow rate, the second is conducted by using Fick's first law. The resulted dissolution rates from the first ‎method are higher than those of the second one.‎

The variation of punch angle on the flow metal for the backward extrusion is investigated ‎theoretically and experimentally. Punches with different semi-cone angles varying from 30, 60, 70, 90 ° ‎have been used to study its effect on the pressure required to extrude indirectly for lead. The findings of ‎this experimental study show agreement in trends with the theoretical predictions. From this study it can be ‎concluded that by a little change in the backward reduction in cross- sectional area different types or ‎modes of extrusion process may be obtained and the streamline profile of the punch surface have an ‎important effect in homogeneity of the material flow in the backward direction i.e. that the working ‎pressure decreased when increasing the punch angles, the fact that the redundant strains will be decreased ‎and there will be less restriction on the material flow also due to the complex deformation situation during ‎the backward extrusion and availability of more than one type of velocity field through the process ‎duration, finite element analysis via ANSYS software may be the superior for application.‎

In recent years, use of various waste products in ground construction and modification has ‎gained considerable attention worldwide in view of increasing costs of waste disposal, and ‎environmental constraints. One of these waste products is the cement kiln dust, which is a by-product ‎of Portland cement manufacturing process. It is generated from burning the raw materials in a rotary ‎kiln to produce clinker. The cement kiln dust used in this study was brought from Al-Kufa cement ‎factory.‎
In this study, the effect of adding different percentages of cement kiln dust on some ‎properties of clayey silt soil was investigated. The results show that the plasticity index, liquid limit and ‎activity of soil decrease significantly as the percentage of added cement kiln dust increases, while the ‎plastic limit increase. The maximum dry density decreases and the optimum moisture content ‎increases as the added cement kiln dust increases. Also, significant improvement in the performance of ‎soil as a subgrade in a highway can be noticed with increase in CKD percentage, due to a reduction in ‎value of the group index.‎

‎ This paper presents an optimal control design for decentralized generator excitation ‎control systems which is suitable for use in power system to damped the oscillation ‎depending on the modern control theory of controllable system by using generator load ‎angle and voltage magnitude behind the quadrature axis transient reactance of generator ‎to represent the interactions among generators, decentralized generator excitation control ‎in multi machine power system can be achieved. Simulation results show that the ‎proposed control improves power system dynamics. ‎

‎ Runway pavements are designed to provide adequate support for loads imposed by aircraft using an ‎airport. To fulfill this requirement, the pavement must be of such quality and thickness that it should ‎not fail under the expected loads.‎
‎ In the process of runway pavement design, the current research has been extended to evaluate the ‎pavement sufficiency of four Iraqi airports (Baghdad International airport, Basrah International ‎airport, Salaymaniyh International airport, and Balad Airfield) ‎‏ ‏by use the (ACN / PCN) method. The ‎investigation discusses the ability of an existing pavement to carry the different types and weights of ‎aircraft traffic. Moreover an improvement to the existing pavement thickness to stand with the ‎expected future load is performed.‎
‎ For four studied airports, the results indicate that an improvement can be achieved by adding various ‎thickness of asphalt concrete overlays or Portland cement concrete. ‎

‎ Corrosion causes metals delivering into the conveyed liquid. If the corrosion be very rapid, it will ‎cause pipes cavitations. Then, the intrusion of contaminants into the pipes result in negative suction and if ‎the water has been scaling tendency, a scale layer will introduce, then induce internal scaling and reduce ‎convey potential in pipes. The aim of this research was determining the potential corrosion and scaling of ‎treated water from two water treatment plants in Al-Hilla city. The variation in water stability with time ‎and places of Al-Hilla city was indicated. Values of Langlier Saturation Index, Ryznar Stability Index, ‎Puckorius Scaling Index ,and Aggressive Index, calculated during 8 months between 2007 to 2008. The ‎calculated results showed that the values of Langlier Saturation Index ranged between -0.098 to 0.46, ‎Ryznar Stability Index ranged between 6.91 to 7.81,Puckorius Scaling Index ranged between 6.76 to ‎‎7.47,and Aggressive Index ranged between 10.88 to 11.88 in Al-Jadeed WTP in the north. Where in the ‎center Al-Kadeem WTP, Langlier Saturation Index ranged between 0.21 to 0.63, Ryznar Stability Index ‎ranged between 6.63 to 7.30, Puckorius Scaling Index ranged between 6.87 to 7.33, and Aggressive Index ‎ranged between 11.35 to 12.08 .By survey of stability indices, it founded that treated water from these two ‎water treatment plants have moderate corrosion potential, and the corrosivity of water decreased in the ‎water following down stream. The water quality parameters affecting LSI,RSI,PSI, and AI were discussed ‎which were alkalinity, pH, total dissolved solids, temperature, hardness, and calcium concentration.‎

In this paper an experimental study was carried out on the effects of manipulating some parts of ‎the air conditioning unit on its coefficient of performance. It covers, effects of an auxiliary condenser, ‎variable fan's speed, changing the coolant of the condenser from air to water with variable volume ‎flow rate, in addition of adopting capillary tube of multiple length.‎
The results show that the C.O.P was increased between 21.6% - 32.2% when the auxiliary ‎condenser was used. But its value only increased by 11.3% - 22.6% when the cooling fluid is changed ‎from air to water. However when two air cooled condensers were used the increasing in C.O.P. ‎was between 6.4% - 16.6% with respect to water cooling condenser‎
It was also found that the length of capillary tube has two opposite tendencies on the C.O.P. of ‎the air conditioning unit . In one of them the value of C.O.P was decreased by 3.8%-8% when the ‎capillary tube's length changed from 1.92 m to 2.4 m, and it was increased by 2.6% - 6.7% when the ‎tube's length decreased from 1.92m to 1.4m

The main goal of this research is to improve the performance of alum used locally by using ‎natural materials and economic such as wheat husk powder, for industrial wastewater treatment for ‎reuse and to put into the river according to Iraqi laws to raise the water. This study was conducted on ‎samples of water, industrial taken from the water posed by the plant silk soft in the district of ‎Musayyib by testing the jar for the selection of potions optimum alum powder and wheat husk ‎powder in addition to that has experience equivalent acid before adding alum to find out the optimum ‎ratio of (pH) of the efficiency of coagulation. It was found that the optimum ratio of retina (200 mg / ‎l) and cobalt powder is wheat (80-100 mg / L) when the value of (PH) is equal to (8.5)‎

The main aim of this research is to make a comparison between the test results of ‎compressive strength for concrete mixes which are designed according to British Standards which ‎represented in concrete cubes have the dimensions of (150*150)mm, with those which are designed ‎according to American Standards and represented in concrete cylinders which have the dimensions of ‎‎(150*300)mm.‎
Three levels are taken for the required compressive strength of concrete (ƒc̑) as follows ‎‎(15,30,45) N/mm2 , laboratory tests are carried for three different ages as follows (7,28,90) day .‎
The average compressive strength obtained is (16.3,31.9,46.3) , (15.6,30.4, 46.2) and ‎‎(15.8,30.1,45.2) N/mm2 in the age of (28)day for maximum size of coarse aggregate (10,20,40) mm ‎for the three levels of required compressive strength (15,30,45) N/mm2 respectively for that designed ‎according to British Standards .‎
The average compressive strength obtained is (21.2,35.6,56.4) , (18.2,32.8, 49.8) and ‎‎(16.5,30.9,45.8) N/mm2 in the age of (28)day for maximum size of coarse aggregate (10,20,40) mm ‎for the three levels of required compressive strength (15,30,45) N/mm2 respectively for that designed ‎according to American Standards.‎‏ ‏‎ ‎