Vol. 11 No. 1 (2018)
Articles
Abstract: This work is a study of the effect of polyethylene glycol (PEG) on electrophoretic deposition )EPD) of alumina and zirconia particles. The effect of polyethylene glycol as a binder material and the toluene as a dielectric liquid, on the pH of suspension, the final thickness and green density of the deposed parts were studied. There was a difference in the behavior of polyethylene glycol when added for the alumina suspension and the zirconia suspension. The increase in polyethylene glycol was useful to deposit the zirconia more than alumina. The pH for both alumina and zirconia suspension increases with the increase of polyethylene glycol content and with the addition of toluene due to increase of the OH– concentration in the suspension. This increase of pH enhances the particle surface charge and enhances the deposition rate, which led to the increase of density of the deposit
Abstract: The alternator depends entirely on the conversion of kinetic energy into electrical energy by the presence of a magnetic factor. Wind energy is defined as the process of converting wind energy into another form of energy that is easy to use. In this paper, a permanent-magnet-alternator (PMA) with full-converter (FC) was used in the wind turbine (WT) generator instead of the excitation coil of the magnetic field. This method was used to save lost energy in the induction coil. A complete wind turbine model with a (FC) was connected to a generator with a fixed magnetic field and an electric grid was fed. This simulation system was completed by PSIM simulation program. In this work, the IP control system was used to operate the simulation system. In this study, a greater stable amount of real and reactive power was obtained from the wind turbine
Abstract: Air vehicle modeling like the helicopter is very challenging assignment because of the highly nonlinear effects, effective cross-coupling between its axes, and the uncertainties and complexity in its aerodynamics. The Twin Rotor Mutli-Input Multi-OutputSystem (TRMS) represents in its behavior a helicopter. TRMS has been widely used as an apparatus in Laboratories for experiments of control applications. The system consists of two degrees of freedom (DOF) model; that is yawing and pitching.This paper discusses the design of Four Interval Type-2 fuzzy logic controllers (IT2FLC) for yaw and pitch axes and their cross-couplings of a twin rotor MIMO system. The objectives of the designed controllers are to maintain the TRMS position within the pre-defined desired trajectories when exposed to changes during its maneuver. This must be achieved under uncertain or unknown dynamics of the system and due to external disturbances applied on the yaw and pitch angles. The coupling effects are determined as the uncertainties in the nonlinear TRMS. A PSO algorithm is used to tune the Inputs and output gains of the four Proportional-Derivative (PD) Like IT2FLCs to enhance the tracking characteristics of the TRMS model.Simulation results show the substantial enhancement in the performance using PSO-Based Interval Type-2 fuzzy logic controllers compared with that of using IT2FLCs only. The maximum percentage of enhancements reaches about 33% and the average percentage of enhancements is about 17.1%. They also show the proposed controller effectiveness improving time domain characteristics and the simplicity of the controllers
Abstract: Interval Type2 Fuzzy Logic Control (IT2FLC) has been applied to a number of industrial, medical, home and military applications. Hardware implementation of IT2FLC can be achieved in a number of ways. One of these ways is the use of a Field Programmable Gate Array (FPGA).In this paper, the design and implementation of an IT2FLC using FPGA has been presented. The proposed controller is of Mamdani type. It works in different structures (P/PI/PD/PID like IT2FLC) depending on two control lines, different number of triangular shape memberships (2-7) depending on three control lines, six tunable gains and within a range of sampling time of (0.01-1024) seconds. Three type reduction algorithms are used and it is found that the Enhanced Iterative Algorithm with Stop Condition (EIASC) produced the minimum reduction in FPGA size. Thus less execution time. The reduction size is about 75% than Karnick Mendel (KM) and is about 3% than Enhanced KM (EKM). Linear and nonlinear models are used to test the designed Controller. Gains are tuned manually to reach minimum overshoot, settling time and steady state error.Simulation and Implementation results showed that the proposed controller works in an efficient way under no-load, load and uncertainty in the nonlinear model parameters.
Abstract: In this work numerical investigation of mixed convection by non-concentric different positions of rotating circular cylinder in square enclosure is investigated. The assumption of using six rotating cylinders at constant temperature Th and square closed enclosure with temperature Tc for all walls are maintained. Continuity, Momentum and energy governing equations are solved by using finite volume technique using Ansys-Fluent 16 commercial code with two dimension and steady state case. Richardson number (Ri=Gr/Re2) varying over the wide range of 0.1, 1, 10,100, 1000 and ∞. This research investigate the effect of changing the rotating circular cylinder positions along the vertical centerline on the fluid flow and heat transfer inside the enclosure. Six different positions are tested. The phenomenon inside the square enclosure is mathematically analyzed. A streamlines, isothermal patterns, local Nusselt numbers, and average Nusselt numbers are calculated. The analytical results give that, the Richardson numbers is playing the dominant role on temperature distributions and flow patterns inside the enclosure. The average Nusselt number variation demonstrates the best location of rotating cylinder which gives best heat transfer value. The bottom left corner (P4) is the best location for hot rotating cylinders. While the rotating in middle right (P6) is the inferior position
Abstract: One of the imperative elements of TCP is the congestion control of the system which happen when numerous info streams touch base at a router whose yield limit is not as much as the whole of the data sources. This paper introduced how Old Tahoe (Congestion Avoidance) could and Tahoe (Fast Retransmit) affect the congestion control. The system was simulated using Network Simulation Program (NetSim) to study the performance of system in terms of delay and utilization for Old Tahoe (Congestion Avoidance) and Tahoe when the congestion occurred and when there is no congestion and no error and the results showed that fast retransmit was better utilization and low delay than congestion avoidance.
Abstract: This study investigates experimentally and numerically the environmental conditions prevailing in a large mechanically ventilated welding workshop which lies in the Basra Oil Training Institute in Iraq. The numerical part was accomplished with the aid of the computational fluid dynamics by ANSYS 15 program. This software program was compared against the results of a resemblance research work ]1[, which shows a good agreement. Numerical results are compared with experimental data collected during different ventilation and occupational conditions of empty and full workshop daily work, and there is a good agreement between experimental data and numerical results. The experimental part was done by using suitable calibrated devices to measure the air velocity, temperature, relative humidity and concentration of CO, CO2 gases in the different locations of the indoor environment of welding workshop. The results of this study demonstrate that the occupants of the existed welding workshop suffer from healthy problems because of the harmful gases, and the inefficient ventilation system used
Abstract: The aim of this paper is to study the microencapsulated phase change materials (MEPCM) suspension as a coolant instead of pure fluid in the micro channel heat sink (MCHS) with different core and wall materials as well as different base fluids. The MEPCM suspension using in this study consist of microcapsules constructed from n-octadecane, RT44 as a phase change materials (PCM) and shell materials are poly-methylmthacrylate (PMMA), poly-alpha olefin (PAO), these capsules are suspended in (pure water, ethylene glycol and pure oil) in a concentration of (0–20)% and have been used as a cooling mediums at different ambient temperatures. Constant heat flux is applied at base of heat sink. The results obtain show that, using MEPCM suspensions as a coolant in micro heat sink instead of conventional cooling with pure fluid lead to enhance the cooling performance of micro heat sink is be 20.91% with (RT44+PMMA) pure oil, 16.91% with (RT44+PMMA) for ethyleneglycol and 12.91% with (RT44+PMMA) for pure water at concentration 2% and
Abstract: Polyvinyl alcohol (PVA) has undergone intensive research work that has led to confidence in its utilization in various applications. Nevertheless, its utilization as a construction material in the concrete industry still needs to be fully addressed. In this paper, an experimental study was dedicated to investigate the influence of PVA on the fresh and hardened properties of concrete. Three different strength grades, represented by water to cement ratios (w/c), of 0.4, 0.5 and 0.6, with four different PVA dosages of 1, 2, 3 and 4%, by mass of cement, were employed in the preparation of the concrete mixes. Concerning the fresh properties, results showed that there was a significant contribution of PVA to the workability in all produced mixes, irrespective of w/c ratio. In addition, the initial and final setting time of cement pastes modified with 2% PVA were longer than that of the control paste. In term of the hardened properties, results demonstrated that the compressive (fcu) and splitting tensile (fst) strengths of concrete are dominated by amounts of PVA in the mix and w/c ratios. With the high and moderate w/c ratios, they increased when up to 2% PVA was used, and thereafter decreased. However, with the low w/c, PVA did not provide any improvement in the strength, but instead, it decreased the strength when more than 2% was added. The findings revealed also that increasing PVA content resulted in a significant reduction in total water absorption (TWA) of concrete specimens. The larger the PVA contents the lower is the TWA of the specimens
Abstract: All people now a day are focusing on an important issue which is 'security' where all Rigid, worthy dealing with, and creditable companies pay a lot of attention for this problem. Therefore the cost, usage, portability must be taken in consideration. This work demonstrate the use of a smart, small, not expensive and the most important realistic portable lock with portable low consumption power supply and security coverage area with minimum side effect and maintenance.This lock is not the representative for a key but it may represent a badge, an ID, or a credit card or social security card …. etc. So it’s very close to the use of the human normal day life and hence it will not be a security burden since the security card may be embedded within other cards like car security card or credit card …etc.The system is implemented and tested with no need for a sophisticated material but easy equipment may stand enough to achieve the job with very accept able cost. The system achieves high security password and a master electronic key that cannot be copied within the available constraint and high control operating environment and a backup plan in case of key lost.
Abstract: Wind energy is one of the cheapest sources of energy that may solve the Climate change problem and fresh water scarcity challenges. This article introduces a novel Desalination Wind Turbine that is cheaper and more efficient than the common wind turbine, especially offshore wind turbines. In this system, the wind energy transmitted to the water pump by a hydraulic transmission line. The RO module is used for fresh water production. The pressure recovery module is added to RO system, to increase the permeated flow. It can be increased the permeate flow up to 45%, which is significant. The Maximum Power Point Tracking (MPPT) based on the hydraulic oil pressure measurement is implemented. In addition, the Maximum Permeate Flow Tracking control loop, similar to MPPT, is introduced to optimized the pressure of the RO system. It is increased the annual permeate production up to 8%. The long term performance of the system, such as annual water production is calculated and the ability of the system to MPPT and the wind turbulence and gust is analyzed. The rotor speed overshoot of the closed loop system is less than 16%, which is acceptable.