Basrah Journal for Engineering Sciences

Fluidized bed reactor (FBR) is an attached growth system used mainly for biological treatment of industrial wastewater of high organic content. These wastewaters are usually resulted from refineries and milk, starch, and olive oil industries. The objective of this study is to investigate the use of fluidized bed reactor for treating sanitary sewage. The study was accomplished using a pilot plant of the FBR. The pilot plant was constructed and installed in Hamdan Sewage Treatment Plant in Basrah governorate. That was to maintain continuous source of settled sewage which is the influent to the FBR. The period of plant operation was nine weeks. During, this period, the plant was operated at three phases of different conditions (up flow velocity and recirculation ratio). To study the performance of FBR, the main measured parameters were; BOD, DO, VSS, pH, and temperature. The most important conclusions of this study are; (1) the maximum efficiency of BOD removal is 78.6% which was obtained for hydraulic retention time (HRT) of 24min and upflow velocity of 1.59m/min, (2) the effluent BOD values during phases-1 and 2 of plant operation match that of stabilization ponds and trickling filters and during phase-3 matches that activated sludge process, (3) during all operation phases, the values of effluent pH are within the limits specified in national standards of secondary effluents, (4) as F/M increases, the efficiency of BOD removal decreases and the maximum efficiency of BOD removal (78.6%) was obtained at F/M ratio equals 23.47 day-1, and (5) the HRT of fluidized bed reactor is on order of minutes, while, the values of HRT of activated sludge systems and stabilization ponds are on order of hours and days, respectively.

In this paper, a new approach for the positioning (localization) of multi-node systems is presented. Each node including the beacon node contains two types of sensors: one for the distance sensing and the other type is for communication. The main idea of our proposed approach is to use the control of beacon to construct a nodes' tree which is going to be used later by the nodes to know the paths in which the information will flow. During the tree construction the identities of nodes will be known. Every node except the beacon will use the information obtained from its previous neighbor in the tree to find its own location and orientation. Several simulations using visual basic 2012 are implemented to discern the performance of this algorithm.

In digital signal processing (DSP), FIR digital filter is very important device to deal with particular frequencies of a certain signal to be appropriate for some applications such as communications, sound equalizers, etc. In this paper, FIR filters are adopted to decompose the original sound signal into four signals. Each one is created by one FIR filter and each filter represents a narrow band of frequencies. The filter output is used to drive a certain variable speed drive (VSD) to control the speed of a water pump and light intensity of a colored lamp. This filter output signal is applied to the analog control voltage terminals of the VSD unit to control the frequency and magnitude of the voltage supplied to the lamp and pump. Thus, the heads of the water jets and the light intensity are controlled according to the analog control signals which are created by the FIR filters (The VSD is used to map the filter output into light intensity and water head by controlling the supplied voltage of them). The goal of this study is to design and simulate four sound harmonics bands produced by FIR filters to drive four VSDs which are simulated using V/F ratio constant method for musical fountain operation.

This paper deals with a new algorithm called circular paths for leader follower tracking with obstacle avoidance using. In leader follower tracking, one robot acts as a leader with defined motion and the other robot acts as a follower which position itself in accordance with the position and orientation of the leader. The leader movement is dependent on an assigned trajectory and the follower movement is dependent on the circular paths algorithm. In each step, this algorithm constructs a circular path using three points represented by the next step position of the leader robot, the last step position and the current step position of the follower robot. The next position of the follower robot lays on the circumstance of the circular path and the orientation is represented by the tangent line to this circular path at this next position of the follower robot. When an obstacle intersect any circular path for the follower robot, then this path must be replaced by another circular path construct from the two positions of the follower robot and the leader position is replaced by the tangent point to the obstacle. Simulation results illustrate the soundness of this algorithm.

In this paper, a new algorithm for mobile robot naviga-tion and polygonal obstacles avoidance in dynamic target envi-ronment is introduced. In the dynamic target path planning the agent (robot) trying to reach a moving target in minimum path cost. The introduced algorithm which called Prediction-based path planning with obstacle avoidance in dynamic target environ-ment planning a path to a moving target by predicting the next target location, then computing a path from the robot current lo-cation to the predicted target location representing each visible obstacle by the smallest circle that enclosing the polygon obstacle, then determine the visible tangents between the robot and the cir-cular obstacle that intersect its shortest path and compute the shortest path. Three target movement scenarios were suggested and tested in different environment conditions. The results show that the target was reached in all scenarios and under all environ-ment conditions with good path cost.

This study aims to evaluate quality of groundwater samples in south of Basrah Province for industrial, construction and agricultural purposes. Groundwater samples were collected in summer season of the year 2015 from (29) wells located in different districts in Basrah province (Safwan, Zubair and Um-Qasir). The groundwater samples were analyzed for pH, electrical conductivity (EC), total dissolved solids (TDS) and other major ions. The chemical results indicate that the groundwater in the study area was unsuitable for industrial uses according to standard classification. Some other standard classification recommended that, the unsuitable groundwater could be used after treatment of some of its element while groundwater in study area may be used for construction purposes with suitable treatment of high ions concentration. After studying the factors that determine the suitability of groundwater for irrigation purpose such as pH, electrical conductivity, total dissolved solids, Sodium ratio(Na%) and sodium adsorption ratio (SAR). The groundwater in study area can be classify based on (EC) values, as unacceptable for irrigation except for very salt-tolerant plants and excellent drainage. According to other parameters like Na% and SAR , groundwater of the study area are classify as poor to very poor water and need for suitable treatment before using it.

In this paper, the Weibull uni-axial and multi-axial distribution function for polyethylene pips under pressure loading were developed and analyzed taking account of residual stress. Tensile test was achieved to determine mechanical properties and the Weibull parameters. Experimental method using the hole-drilling strain-gage method was used to measure the residual stresses in PE pipe and compare with that obtained from numerical finite element method (FEM). The obtained results show that there is a convergence between uni-axial and multi-axial distribution function, but multi-axial distribution function give large values compared to uni-axial distribution function. It was observed that the residual stresses have influence on failure assessment diagram and causes translation from elastic-plastic failure to brittle failure.

The choice of aggregate type in producing reinforced concrete depends on the availability of the source sometimes and the intended concrete requirements like lightweight or normal aggregate concrete or high strength concrete. The punching shear resistance is being considered to be influenced by numbers of parameters including aggregate size and types. These parameters have not accounted in most of codes of design and have given a little attention by researchers. Most of available knowledge are based on outcomes from experimental works on beams. In this paper, the considerable slab tests without shear reinforcement are collected from literature in which aggregate types and sizes are given and they were failed in punching. The test results are compared to those calculated by ACI, EC2 and CSCT. The deficits of shear resistance are found clear where high compressive strength is combined with reinforcement ratio.

In this study, a numerical investigation has been carried out for single phase flow behavior for thirty six internally finned tubes to demonstrate the effect of axial pitch to fin height ratio (p/e) for 0.8≤p/e≤6.345, helix angle of internal fins (β) for 30°≤β≤70°, apex angle of internal fins (α) for 0°≤α≤53.13°, internal fin height (e) for 0.6mm≤e≤1.0mm, internal tube diameter (di) with 14 mm and Reynolds number (Re) of single phase flow for 10000≤Re≤50000 on enhancement of forced convection heat transfer and reduction of friction factor by using ANSYS CFX program. It solves the three-dimensional Navier-Stokes equations for steady state turbulent with SST model and enhance wall treatment. The numerical analysis provided at fully developed velocity and temperature. Numerical results showed that the smallest axial pitch to fin height ratio (p/e) =0.8 and with apex angle α=10 degree provided enhancement of heat transfer of 2.8 to 3.55 times higher than of smooth tube. Finally, present numerical results are seen to be in good agreement with literature experimental correlations.

This study presents solar chimney power plant integrated with sea water desalination system. A simple mathematical model is based on the conservation of mass and energy. The results show that the integrated system of solar chimney power plant and solar still can achieve simultaneously. The analysis is performed for both summer and winter at latitude 30oN. It’s noted that, the water layer thickness is of a significant effect on the fresh water productivity while the dimensions of solar chimney and the solar collector are of a minor effect. The productivity of fresh water and output power for summer are the highest. The present work is compared with experimental data of the other work and showed a good agreement.

Pipelines are one of the most convenient and effective ways of transporting petrol over a long distance. The environment applies, beyond extremely high external pressures, low temperatures and intensive corrosive process, the occurrence of defects on the pipe body, which compromises the structural integrity of pipelines leading to catastrophic failures. The main modifications concern the mechanical resistance, toughness at low temperatures weld ability and resistance to embrittlement related to hydrogen. Among mechanical characteristics, the fracture toughness is very important for pipeline steels in design and safe assessment. Aiming to enhance the reliability and operation of complex pipelines system, a study based on the mechanics of the elastoplastic fracture in order to determine better prediction of the fatigue life. The materials tested here are API 5L X42 and X52 micro alloyed steels, as well as to evidence the toughness resistance of these materials. Results indicated that both X42 and X52 steel behave in a similar way and in all cases a slight increase of the transition temperature was found. The characteristic toughness value shows an evident loss in mechanical performances if compared to the uncharged one.