https://repository.sustech.edu/handle/123456789/16649 2026-04-07T23:32:20Z https://repository.sustech.edu/handle/123456789/16650 Quality Assessment of Afrotan Tannery Drinking Water Wells Yassen , Alfatih A.; Gasmelseed , Gurashi A.Allah; Almaged , A. Alsalam A.; Alhaj , Dai Aldain A. Afrotan tannery was established in 1983, in Albageer Industrial Area- Algazeera State - Sudan. It tans about 20000 skins per day. It uses different harmful amounts of chemicals in tanning processes and it discharges these harmful effluents in land near three drinking water wells. The objective of this study is to assess the quality of these wells and to investigate the contamination of the tannery effluents in the drinking water. Three liters of the tannery tap water was collected from a water reservoir which is fed by the above three wells. 24 parameters of Sudanese Standard Specifications for drinking waters and all the tannery effluents which are expected to contaminate the drinking water wells were measured. The results showed that there is no contamination of tannery effluents to the tannery drinking water wells, and all measured parameters were within the permissible levels of Sudanese Standard Specifications for drinking water. The study recommended periodic conduction of such studies in the future and to take the samples directly from each well to investigate any contamination. article 2016-01-01T00:00:00Z https://repository.sustech.edu/handle/123456789/16651 Determination the Composition of Afrotan Tannery Sludge’s in Sudan Yassen , Alfatih A.; Gasmelseed , Gurashi A.Allah; Almaged , A. Alsalam A.; Alhaj , Dai Aldain A. Afrotan tannery was established in 1983 in Albageer Industrial Area- Algazeera State - Sudan. It tans about 20000 skins per day and generates high amount of waste water. Beside the tannery, there are three units of waste water treatment. These treatment units precipitate high amounts of sludge in sedimentation tanks of these units. The tannery collects all this sludge, treats by adding Aluminum sulphate, lime and Poly electrolyte respectively, dewaters by pressing by centrifuge machine and fills it in land. The aim of this study is to determine and to investigate the parameters in sludge before treatment (slurry sludge) and after treatment (dewatered sludge). The analysis was carried out by using standards methods for the Examination of Water and Waste Water, Edition 20, (1998). The results showed that the values of BOD, COD, TVS, NH3, NH4, NO3, SO3, SO4, Cl, Fe, Ca, Na, K, Al and Cr in slurry sludge (before treatment) were found to be 33600 mg/l, 56000 mg/l, 96.0%, 196 mg/kg, 238 mg/kg, nil, 0.25 %, 0.624%, 6747.8 mg/l, 16.18 mg/l, 18.421 mg/l, 8.864 mg/l, 10.609 mg/l, 0.00215 mg/l and 13.23 mg/l, respectively. The values of these parameters in treated and dewatered sludge (after treatment) were found to 40000 mg/l, 68000 mg/l, 81.7%, 252 mg/kg, 306 mg/kg, 28 mg/kg, 1.2 %, 1.44 %, 5100.8 mg/l, 4.911 mg/l, 21.328 mg/l, 9.041 mg/l, 8.146 mg/l, 0.00189 mg/l and 5.897 mg/l, respectively. The study recommended that it is important to prevent filling this sludge in the land to avoid soil contamination and also to conduct further studies to use this sludge in agriculture or others purposes. article 2016-01-01T00:00:00Z https://repository.sustech.edu/handle/123456789/16653 Performance Evaluation of a Fractional Order PID Controller Applied to Separately Excited Direct Current Motor Speed Control Ahmed , Aamir Hashim Obeid At the present time, Direct Current (DC) motors have been widely used in many industrial applications. The main reason for their popularity is the ability to control their torque and flux easily and independently. The most commonly used controller for the speed control of DC motor is conventional Proportional-Integral-Derivative (PID) controller. However, the conventional PID controller has some disadvantages. To overcome these disadvantages, various types of modified conventional PID controllers such as Fractional Order PID (FOPID) controllers were developed. This paper presents a comparison of time response specifications between FOPID and conventional PID controllers for a speed control of DC motor. Performance of two controllers has been verified through simulation results using MATLAB/SIMULINK software. Simulation results show that the FOPID controller performs better performance and more robustness than a conventional PID controller. article 2016-01-01T00:00:00Z https://repository.sustech.edu/handle/123456789/16654 7049 AL-Alloy Fatigue Behavior under Black Paint Laser Peening Alalkawi , Hussian J.; Saeed , Madlool Awad; Khenyab , Ali Yousuf Black Paint Laser (bPL) peening technique is currently applied to engineering components due to their improvements of fatigue behavior and economic advantages. In the current work, the experimental examinations of bPL peening, which aims to understanding the fatigue behavior of bPL surface treated bars was carried out. The application of bPL was associated with significant extension of fatigue life and strength. This extension is due to compressive residual stresses (CRS) generating from peening process. A series of fully rotating bending fatigue tests was conducted at room temperature using 7049 Aluminum alloy. Improvements in fatigue life and strength for constant and cumulative fatigue were demonstrated. Finally, the fatigue strength of 7049 Aluminum alloy at 107 cycles increased by 53% and cumulative fatigue life improved by factors of 1.55 and 1.787 for Low-high sequence and high-low sequence due to bPL treatment respectively. article 2016-01-01T00:00:00Z