Basrah Journal for Engineering Sciences

Data sets of highest monthly rainfall for the period (1887-1958) are used for evaluating the proper theoretical statistical distribution of extreme monthly rainfall in Baghdad city. The frequency analyses and most statistical test were done using a commercial version of HYFRAN. Five distributions are used in this research, which are: - Normal, Pearson Type III, Lognormal, 3-parameter lognormal and Gumbel. Estimation of theoretical distribution is achieved by using maximum likelihood method and adequacy test is carried out using chi-square test. Lognormal, 3-parameter lognormal, and Gumbel distributions seem to be suitable for representing of maximum monthly rainfall in the study area.

An experimental and theoretical study of light weight concrete filled aluminum tubes having circular hollow section is presented in this paper. The structural performance of columns was investigated using different light weight concrete fashions and compressive strengths. The column specimens were subjected to uniform axial compression with two different loading styles, in the first one (composite action); aluminum tube is utilized to be axially loaded as well as its confining function, and in the second loading style (confinement action), aluminum tube is utilized to confine concrete core only. The aluminum circular hollow sections have nominal proof stress, f0.2 = 170 MPa. A grade of light weight expansion clay aggregate (LECA) is used to fabricate light weight concrete. The strengths, axial load- shortening displacement relationship, axial and lateral strains, and failure modes of columns are presented. The unfactored strengths predicted are found to be in a good agreement with the experimental values using the general design guidelines specified in the American specifications and Euro code.

Construction projects are complex projects and their organisations are characterised by a high degree of fragmentation since they are distributed in large areas and clearly they involves of many activities, each one being divided into sub-activities and so on. Hear clear and good communication between projects stakeholders leads to the project being more successful in contrast to when the communication is weak. This paper compares two methods of communication used in Iraqi construction projects during the implementation stage, namely the Face to Face (FTF) approach which is characterised as expensive and disruptive and Computer Mediated Communication (CMC) which represents the modern method in the communication field. The results show that the CMC method is more productive and economic than FTF and takes less time when completing an implementation work; in addition, the people are less affected by emotional factors in the construction project in contrast to FTF.

In this paper, we present a new chaotic circuit based on the dynamical system introduced by E. Lorenz in the Journal of the atmospheric sciences, Vol. 20, 130-141(1963). The design and implementation of the circuit are accomplished by using a field programmable analog array (FPAA). The implementation of chaotic Lorenz attractor discussed in this paper is not present in the literature. The experimental results shown in this paper demonstrate that the circuit exhibits pre-chaotic transient and chaotic Lorenz attractor.

Using simple analytical procedure, a tuning rules for two degree of freedom (2-DOF) PI/PID controllers are presented. The proposed tuning algorithm assumes first order plus delay time and second order plus delay time as plant models to be controlled. The validity and features of the proposed tuning rules have been investigated by computer simulation study. Simulation study showed that the presented controllers have high performance response for step input changes and also that these rules are robust for load disturbance.

In this paper a combining Neurofuzzy and PID controllers have been employed for controlling the positions and rotational motions of the mini-helicopter system. Due to the strong coupling between the state variables of the mini-helicopter model, therefore, it is not suitable to design single controller for regulating the positions and rotational motions of the given model. To solve this problem, three neurofuzzy controllers are designed for the lateral, longitudinal and heave motion; and three classical PID controllers are proposed for attitude control. Nine rules are suggested for each neurofuzzy network depends on the previous knowledge/experiences of expert human pilot. The simulation results show that the proposed controllers are very effective to control the hovering, position and forward flight of the mini-helicopter system.

Castor Oil is a natural raw material, used to prepare Brominated Castor Oil (BCO) and quaternary ammonium salt based castor oil (TEt-CO). The two products were tested as demulsifiers and compared with a commercial demulsifier (Chimec2439) by using bottle test method. BCO showed a high ability on water separation efficiency 90% with a dose of 150μl at 120min time settling while TEt-CO showed a low water separation efficiency reached to 10%. The effect of the demulsifier BCO was tested by varying different variables which have an obvious effect on water separation efficiency such as: dose, temperature, time of mixing emulsion, pH and salinity of aqueous phase of emulsion, and water ratio. The effect of some additives (i.e. methanol, ethanol, xylene and toluene) on the efficiency of the BCO was tested for the purpose of enhancing its effectiveness to break the crude oil emulsion. The experimental data obtained by using BCO were formulated as a model using the Artificial Neural Networks (ANNs) to evaluating the water separation efficiency. Multi-layer perceptron artificial neural network was developed based on the collected data of this study. The results showed that the training algorithm of back propagation (BP) is sufficient enough in predicting BCO efficiency under different operation conditions. It was found that the correlation coefficient values are 0.9995 and 0.9999 for the testing and training data, respectively and the mean square error (MSE) was 6.18*10-5 at 200 epochs.

4-Stearoylresorcinol was prepared by acylation of resorcinol with stearoyl chloride in the presence of zinc chloride as catalyst in a batch reactor. The temperature range of reaction was (50-80)C. The rate of acylation increased with temperature up to (70 C). The conversion of reactants appeared to follow second order kinetic model. The reaction rate constant was (0.0031 l/mol.min) and was higher at higher temperatures. Activation energy was (16.8258 kJ/mol). The optimal catalyst concentration was (2.9936 mol/l). Also, a quantitative relationship was derived to represent the weight of the product as a function to the reaction variables. The quantitative relationship gave mean deviation equal to (5%). The product concentration was measured by UV spectroscopy.

The effect of fouling due to scale formation of pre-heater tubes on the thermal performance of Reticulating multi stage flash Distillation plant performance ratio and the increase of the ratio of Makeup water to the product Quantity for a 5MGPD recirculating System has been prediction .The results appeared That eth Effect of scale formation is more Effected as the Maximum brine temperature decrease.

An incompressible three dimensional continuity and Navier-Stokes (momentum equations) equations are numerically solved to obtain the pressure drop and fluid friction in laminar steady state micro-channel flow of water. The governing equations are solved by using SIMPLE algorithm with finite volume method and FORTRAN code to obtain pressure field in rectangular micro-channel and then from the pressure field both friction factor f and friction constant Cf are obtained. The results showed that the factors affecting the pressure drop, friction factor f and friction constant Cf are; channel length L, Reynolds number Re, aspect ratio α, channel volume chV and hydraulic diameter hD . Increasing of channel length L leads to increase each pressure drop, f and Cf. On other hand, increasing of Re leads to increase pressure drop and decrease the f, while the Cf increase with low value of Re (Re less than 50) and then nearby with approximately constant value. Moreover, increasing of α, chV and hD each separately leads to decrease pressure drop and increase both f and Cf.

In this paper, computation fluid dynamics model (CFD ) is used to simulate a turbulence flow fields along the jet ejector. A Steady-state 2-D compressible flow model utilities the standard k-ε turbulent model has been used. The performance of jet ejector is simulated by FLUENT 6.3 (code) and GAMBIT software, using finite-volume scheme to solve transport NAVIER STOKE equations. The objective of this study is to investigate the high-performance of jet ejector geometry ( mass flow and head ratio) nozzle to throat diameter at eight cases (DN/DT) with different initial pressure. Research is performed to optimize jet performance by varying initial pressure and nozzle diameter ratios from (1/8 ) to ( 8/8 ).
To increase understanding of the axial velocity distribution at an important regions along the ejector, three regions are chosen, at inlet (1,3), nozzle exit(2) and midpoint of throat(4), with an important different diameters ratio cases 1,2,3,5,7 and 8 respectivly. The comparison of these results is presented by the axial velocity magnitude, mass and head ratio of the ejector at the above cases.
Results show that higher pressure ratio and mass ratio (high performance) occur when the nozzle to throat diameter ratio (DN/DT) was (5/8) and (1/8) respectively. Also mass ratio is decreased at all initial pressure when the diameter ratio increased.

The problem of construction debris has been emerged as one of the most important environmental problems in the Iraqi governorates due to higher rates of population growth and the need for the establishment of new construction projects to rebuilding Iraq. Therefore, this research aims to estimate the quantity of construction debris in Basra governorate and suggested method for recycling the homogeneous to rubble material that can be used in the building after admixing with cement. The study estimated the quantity of this debris in Basra during the study period, amounting to a full year up to 177.907 tons, that is equivalent to an average of 0.06 tons/m². And recycling of debris concrete to give the results of the usual approach to the concrete and be within the limits allowed in the code of Iraq and the U.S. and can be used in the production of non-loading concrete blocks.