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Go to Editorial ManagerThe excitation and governing control of generator play an important role in improving the dynamic and transient stability of power system. Typically the excitation control and governing control are designed independently. This paper, presented Neuro-Fu;,.zy methods for the excitation and governing control . Neuro-Fuz.zy system is applied to generate two compensating signals to modify the controls dwing system disturbances. A single machine to infinite bus (SMIB) system is applied in simulation. The MATLAB SIMULIK and S-function technique is used to simulate the system and controllers
A five-phase two-motor drive system with a series connection of stator windings and decoupled dynamic control is considered in the present paper. The two-motor drive system is supplied from a single five-phase Space Vector Pulse Width Modulation (S VPWM) Voltage Source Inverter (VSI) and controlled using a vector control scheme, provided that the stator windings are connected in series with appropriate phase transposition. The concept has been developed under the assumption that the inverter voltages are controlled in the stationary dq-reference frame. A fuzzy logic-based speed controller has been constructed and used to drive the two-motor in this work. The two-motor system, inverter system, and fuzzy controller models are implemented and tested using Simulink/Matlab facilities. 1be presented results show the validity of the model to do well for the sake of speed control in wider different operating conditions.
A new model of bubble dynamics is constructed using linear wave equation, including effects of variation of the gas temperature inside the bubble and the liquid temperature near the bubble, and effects of evaporation-condensation of the liquid vapour at the bubble wall. The liquid is assumed water and the gas inside the bubble is only vapour (neglecting non-condensable gas). The temperature inside the bubble and the liquid temperature are numerically calculated by solving the energy equation both inside (vapour-phase) and outside (liquid-phase) the bubble (using finite difference method). The pressure inside the bubble is obtained numerically without assuming that it follows any assuming relation. The results reveal that the bubble radius, the liquid temperature, and the pressure and temperature inside the bubble change with time periodically. Both the pressure and temperature become higher when the radius becomes minimum. The present theoretical result is compared with data from other reference and with another theoretical model to check the validity of the present model. The calculated result approximately fits with the data of the previous studies.
By using linear wave equation a new model of bubble dynamics in acoustic field is constructed including effects of thermal conduction both inside and outside a bubble, and non-equilibrium evaporation and condensation of water vapour at bubble wall. The liquid temperature at bubble wall is numerically calculated by solving the heat conduction equation (without assuming a profile of liquid temperature). It is including effect of the latent heat of non-equilibrium evaporation and condensation at bubble wall. It is concluded that the liquid temperature increases to the same order of magnitude with that of the maximum temperature attained in the bubble at strong collapses. It is caused by the latent heat of intense vapour condensation and by the thermal conduction from the heated interior of the bubble to the surrounding liquid. The intense vapour condensation takes place at strong collapses because the pressure inside the bubble increases. The comparison is given between the calculated result and the experimental data of radius-time curve for one acoustic cycle. The calculated result fits well with the experimental data.
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.
A new model of bubble dynamics is constructed using linear wave equation, including effects of variation of the gas temperature inside the bubble and the liquid temperature near the bubble, and effects of evaporation-condensation of the liquid vapour at the bubble wall. The liquid is assumed water and the gas inside the bubble is only vapour (neglecting non-condensable gas). The temperature inside the bubble and the liquid temperature are numerically calculated by solving the energy equation both inside (vapour-phase) and outside (liquid-phase) the bubble (using finite difference method). The pressure inside the bubble is obtained numerically without assuming that it follows any assuming relation. The results reveal that the bubble radius, the liquid temperature, and the pressure and temperature inside the bubble change with time periodically. Both the pressure and temperature become higher when the radius becomes minimum. The present theoretical result is compared with data from other reference and with another theoretical model to check the validity of the present model. The calculated result approximately fits with the data of the previous studies.
Although estuarine locations provide natural safety and protection for the construction of harbours and other infrastructure, they are prone to natural filling due to sediment settlement. As a result, dredging is required regularly to keep navigation channels and harbours safe and functional. A numerical model has been developed in this study to compute annual sediment load in Khour Al-Zubair Port, South of Iraq, setting up a MIKE 21 FM model. MIKE 21 FM was developed by the Danish Hydraulic Institute (DHI) where provides the capability of simulation of a hydrodynamic model (HD) coupled with the mud transport model (MT). The model operates with an unstructured mesh of triangles and quadrilateral elements of different sizes. Field and experimental data were provided during two periods (Neap and Spring) for calibration and verification process. According to the sensitivity analysis results, it is clear that the settling velocity is an essential parameter. Based on the results of the calibrated model, there is annual sedimentation of 1220500.64 tons/year. The primary deposition took place in the meandering of the Khour Al-Zubair estuary and behind the piers.
A new model of bubble dynamics is constructed using linear wave equation, including effects of variation of the gas temperature inside the bubble and the liquid temperature near the bubble, and effects of evaporation-condensation of the liquid vapour at the bubble wall. The liquid is assumed water and the gas inside the bubble is only vapour (neglecting non-condensable gas). The temperature inside the bubble and the liquid temperature are numerically calculated by solving the energy equation both inside (vapour-phase) and outside (liquid-phase) the bubble (using finite difference method). The pressure inside the bubble is obtained numerically without assuming that it follows any assuming relation. The results reveal that the bubble radius, the liquid temperature, and the pressure and temperature inside the bubble change with time periodically. Both the pressure and temperature become higher when the radius becomes minimum. The present theoretical result is compared with data from other reference and with another theoretical model to check the validity of the present model. The calculated result approximately fits with the data of the previous studies.
Since the 1970s, rainwater harvesting has gained more attention, specifically in semi-arid and arid areas. It is essential to take into account how much water can be collected from a single catchment site. Rainfall that has been harvested provides an alternative source of water in the northern region of Iraq. Numerous scholars have developed and executed a range of strategies and guidelines to choose appropriate locations and methods for rainwater harvesting (RWH). However, choosing the optimal method or set of rules for the choice of site is challenging. This study's primary goal was to evaluate previous research regarding the selection of appropriate RWH locations in northern Iraq by assembling a list of the most important techniques and guidelines that evolved over the previous thirty years. The primary factors considered in the process of choosing acceptable locations for RWH were soil type, slope, land use/cover, rainfall, and runoff. A literature review for RWH indicated that these criteria were chosen more frequently and significantly, and the opinions of experts should be used to establish the weight of each criterion. The majority of studies select RHW sites using geographic information systems, hydrological models, and multi-criteria analysis.
A composite beam is an accumulation of different materials so as to form a single unit to exploit the prominent quality of these materials according to their position within the cross-section of the composite beam. The present study investigates the structural behavior of six simply supported composite beams, in which a reinforced concrete T-beam is connected together with a steel channel located at the bottom of a T-beam by means of headed stud shear connectors. The used degrees of shear connection are (100%, 75%, 50%, and 38%). Three dimensional nonlinear finite element analysis has been used to conduct the numerical investigation for the general behavior of beams which are subjected to central point load. ANSYS 12.1 program code was used to estimate the ultimate loads, deflections, stresses, strains, end slip. Concrete was modeled by brick element (SOLID65), while the steel channel was modeled as brick element (SOLID45). Two-node discrete elements (LINK8) are used to represent the steel reinforcement and shear connectors. Perfect bond between the reinforcing rebars and the concrete was assumed. The load on beams was applied monotonically in increments up to failure. The reduction of the degree of shear connection from 100% to 38% causes increasing of strain, mid span deflection and end slip with an average of 3.95%, 13%, and 111% respectively, while the ultimate load decreases with an average of 7.3%. In order to observe the efficiency of the 3-D model, a comparison was made with available experimental work. Good agreement was obtained throughout this work between the finite element and available test results.
A new model of bubble dynamics is constructed using linear wave equation, including effects of variation of the gas temperature inside the bubble and the liquid temperature near the bubble, and effects of evaporation-condensation of the liquid vapour at the bubble wall. The liquid is assumed water and the gas inside the bubble is only vapour (neglecting non-condensable gas). The temperature inside the bubble and the liquid temperature are numerically calculated by solving the energy equation both inside (vapour-phase) and outside (liquid-phase) the bubble (using finite difference method). The pressure inside the bubble is obtained numerically without assuming that it follows any assuming relation. The results reveal that the bubble radius, the liquid temperature, and the pressure and temperature inside the bubble change with time periodically. Both the pressure and temperature become higher when the radius becomes minimum. The present theoretical result is compared with data from other reference and with another theoretical model to check the validity of the present model. The calculated result approximately fits with the data of the previous studies.
This research is an analytical study for simulation both sediment transport and flow within the Tigris river reach located downstream of the Al-Amarah barrage within the Maysan province. This study adopted a three-dimensional program (SSIIM) which use the Navier-Stokes equations for calculating the flow, and the convection-diffusion equations for calculating the sediment transport by the finite volume method as approximated method. A structured non-orthogonal three-dimensional grid is employed to perform the simulation. The obtained results are subsequently compared to the field measurements. The determination coefficient ( R 2 ) for this comparison is 0.96 for flow velocity distribution and 0.94 for sediment concentration distribution. The results also showed through the simulation of the water flow, the state of the secondary flow and its effect on both the main flow and the erosion of the river bed in the studied cross sections. According to the high convergence of the results of this model with the field measurements, this model is a powerful tool for simulating flow and sediment concentrations in river systems and channels.
A new model of bubble dynamics is constructed using linear wave equation, including effects of variation of the gas temperature inside the bubble and the liquid temperature near the bubble, and effects of evaporation-condensation of the liquid vapour at the bubble wall. The liquid is assumed water and the gas inside the bubble is only vapour (neglecting non-condensable gas). The temperature inside the bubble and the liquid temperature are numerically calculated by solving the energy equation both inside (vapour-phase) and outside (liquid-phase) the bubble (using finite difference method). The pressure inside the bubble is obtained numerically without assuming that it follows any assuming relation. The results reveal that the bubble radius, the liquid temperature, and the pressure and temperature inside the bubble change with time periodically. Both the pressure and temperature become higher when the radius becomes minimum. The present theoretical result is compared with data from other reference and with another theoretical model to check the validity of the present model. The calculated result approximately fits with the data of the previous studies.
An investigation was conducted to study the effect of loading level with respect to shear center and span length on lateral torsional buckling of steel I-section beams using linear and nonlinear finite element analysis available in ANSYS (version 12.0) computer program. The steel beams which have been studied included prismatic beams and linearly web- tapered beams with web tapering ratio of (0.5). The maximum height of all beams was 300 mm with span length of 4, 6 and 8 m. The critical buckling loads for prismatic and linearly tapered cantilever and simply supported beams subjected to point load and uniformly distributed load were determined. The results showed that, the bottom flange loading gives a buckling loads higher than that of the top flange loading with percentage increases of 148% and 155% for the linear and nonlinear analysis respectively for the prismatic beams. While for the tapered beams, these percentages increases were 61% and 67% respectively.
A new model of bubble dynamics is constructed using linear wave equation, including effects of variation of the gas temperature inside the bubble and the liquid temperature near the bubble, and effects of evaporation-condensation of the liquid vapour at the bubble wall. The liquid is assumed water and the gas inside the bubble is only vapour (neglecting non-condensable gas). The temperature inside the bubble and the liquid temperature are numerically calculated by solving the energy equation both inside (vapour-phase) and outside (liquid-phase) the bubble (using finite difference method). The pressure inside the bubble is obtained numerically without assuming that it follows any assuming relation. The results reveal that the bubble radius, the liquid temperature, and the pressure and temperature inside the bubble change with time periodically. Both the pressure and temperature become higher when the radius becomes minimum. The present theoretical result is compared with data from other reference and with another theoretical model to check the validity of the present model. The calculated result approximately fits with the data of the previous studies.
This paper aims to investigate the effect of Ag nanoparticles addition in different percentages (0.12 wt. %, 0.15 wt. %, 0.25 wt. %, 0.35 wt. %) on the microstructure properties of Cu-21%Zn-6%Al shape memory alloy. Optical and SEM were carried out to studied such effects. Two heat treatments were carried out at (825 ℃ and 850 ℃) for 10 min and quenched in ice water. It was observed that both of heat treatment lead to formation M18R martensite with V-shape and needle like, but raising the temperature of heat treatment from 825 ℃ to 850 ℃ lead to a decrease formation α phase, which leads to improving the shape memory properties. Refinement of the grain size resulted as Ag nanoparticles addition increased from 0 to 0.25 wt. %, the grain size decreases from 1551 μm to 212 μm with reduction of 86.32 wt. % at 0.25 wt. % Ag. The microstructure observation indicated that the Ag nanoparticles addition leads to creating a multi-variant oriented martensite microstructure after quenching process in ice water.
A new model of bubble dynamics is constructed using linear wave equation, including effects of variation of the gas temperature inside the bubble and the liquid temperature near the bubble, and effects of evaporation-condensation of the liquid vapour at the bubble wall. The liquid is assumed water and the gas inside the bubble is only vapour (neglecting non-condensable gas). The temperature inside the bubble and the liquid temperature are numerically calculated by solving the energy equation both inside (vapour-phase) and outside (liquid-phase) the bubble (using finite difference method). The pressure inside the bubble is obtained numerically without assuming that it follows any assuming relation. The results reveal that the bubble radius, the liquid temperature, and the pressure and temperature inside the bubble change with time periodically. Both the pressure and temperature become higher when the radius becomes minimum. The present theoretical result is compared with data from other reference and with another theoretical model to check the validity of the present model. The calculated result approximately fits with the data of the previous studies.
A novel hiding system is proposed in this work which is based on Least Significant Bits (LSB) embedding of information such as speech in gray scale images. The proposed hiding algorithm embeds the secrete infonnation message bits in the least significant bits of the cover image pixels such that the number of secrete infurmation bits to he embedded in least significant bits of cover image pixel is variable and detennined randomly. So that cover image pixel may contain no secrete information bit, one bit, two bits , or three bits according to the pseudo random nwnber generator that generates integer numbers randomly between O and 3. The resulting image (the cover image within which the secret information is hidden) is called stego_image. Stego_image is closely related to the cover image and does not show any details of the secret infonnation. It ensures that the eavedroppers will not have any suspicion that message bits are hidden in the illll!ge and standard steganography detection methods can not estimate the locations in which the secret message bits are embedded and can not estimate the locations in which the secrete information bits are hidden nor the number of bits embedded in oover image . The proposed system achieves perfect reconstruction of the secret message.
A new model of bubble dynamics is constructed using linear wave equation, including effects of variation of the gas temperature inside the bubble and the liquid temperature near the bubble, and effects of evaporation-condensation of the liquid vapour at the bubble wall. The liquid is assumed water and the gas inside the bubble is only vapour (neglecting non-condensable gas). The temperature inside the bubble and the liquid temperature are numerically calculated by solving the energy equation both inside (vapour-phase) and outside (liquid-phase) the bubble (using finite difference method). The pressure inside the bubble is obtained numerically without assuming that it follows any assuming relation. The results reveal that the bubble radius, the liquid temperature, and the pressure and temperature inside the bubble change with time periodically. Both the pressure and temperature become higher when the radius becomes minimum. The present theoretical result is compared with data from other reference and with another theoretical model to check the validity of the present model. The calculated result approximately fits with the data of the previous studies.
It is very crucial to minimize the environmental impact that induced from the development of industry, by applying strict policies and innovate eco-friendly industries. Indeed, construction manufacture considered as one of the most industries that affect the environment, especially concrete production and usage in structural buildings. For instance, traditional concrete, which is consists of a high amount of cement, is contributed to the emission of CO 2 . Therefore, researchers seeking to develop a new technology of concrete by replacement some amount of cement by materials which are considered to become more friendly to the environment. Nowadays, this new technology is known as Green Concrete. The importance of using green concrete is not only to decrease the emission amounts of CO 2 but also to replace cement by industrial waste. In this paper, a review has been presented to understand green concrete benefits and materials that may be used instead of cement and aggregate.
A new model of bubble dynamics is constructed using linear wave equation, including effects of variation of the gas temperature inside the bubble and the liquid temperature near the bubble, and effects of evaporation-condensation of the liquid vapour at the bubble wall. The liquid is assumed water and the gas inside the bubble is only vapour (neglecting non-condensable gas). The temperature inside the bubble and the liquid temperature are numerically calculated by solving the energy equation both inside (vapour-phase) and outside (liquid-phase) the bubble (using finite difference method). The pressure inside the bubble is obtained numerically without assuming that it follows any assuming relation. The results reveal that the bubble radius, the liquid temperature, and the pressure and temperature inside the bubble change with time periodically. Both the pressure and temperature become higher when the radius becomes minimum. The present theoretical result is compared with data from other reference and with another theoretical model to check the validity of the present model. The calculated result approximately fits with the data of the previous studies.
A new model of bubble dynamics is constructed using linear wave equation, including effects of variation of the gas temperature inside the bubble and the liquid temperature near the bubble, and effects of evaporation-condensation of the liquid vapour at the bubble wall. The liquid is assumed water and the gas inside the bubble is only vapour (neglecting non-condensable gas). The temperature inside the bubble and the liquid temperature are numerically calculated by solving the energy equation both inside (vapour-phase) and outside (liquid-phase) the bubble (using finite difference method). The pressure inside the bubble is obtained numerically without assuming that it follows any assuming relation. The results reveal that the bubble radius, the liquid temperature, and the pressure and temperature inside the bubble change with time periodically. Both the pressure and temperature become higher when the radius becomes minimum. The present theoretical result is compared with data from other reference and with another theoretical model to check the validity of the present model. The calculated result approximately fits with the data of the previous studies.
Recently, Internet of Thing technology has been used to develop numerous applications, this paper compromising design and implementation of greenhouse prototype that integrated with the IoT to adjust the system’s parameters and monitor the system status from any place in this world. This system involves three intelligent controllers that designed to stabilize the temperature degree, water level in soil, and light intensity inside the greenhouse prototype structure. These systems have been built by two important parts: the hardware and software. The hardware part could be achieved by designing and implementing the control circuits, actuators, and install the sensors as well as the devices. The second one is the software part which is involves implementing Fuzzy Inference Engine that represent the system’s brain that monitor and manage the entire process in the system to ensure the best performance. This system has been built to contain three control systems that means there are three different Fuzzy controllers. In order to keep the system practicality, the fuzzy controllers should be aggregated in single code that resides in single microcontroller chip with additional codes that perform the IoT duties. The proposed IoT system provides the ability for specific people to monitor and manage their systems remotely, using a web application with cloud technology. The major contributions of the proposed system are started by downloading the controller’s set-points (the desired environmental conditions) from the web page, transfer the set- points to the controllers, and upload data that read from sensors to the same web page.)
A new model of bubble dynamics is constructed using linear wave equation, including effects of variation of the gas temperature inside the bubble and the liquid temperature near the bubble, and effects of evaporation-condensation of the liquid vapour at the bubble wall. The liquid is assumed water and the gas inside the bubble is only vapour (neglecting non-condensable gas). The temperature inside the bubble and the liquid temperature are numerically calculated by solving the energy equation both inside (vapour-phase) and outside (liquid-phase) the bubble (using finite difference method). The pressure inside the bubble is obtained numerically without assuming that it follows any assuming relation. The results reveal that the bubble radius, the liquid temperature, and the pressure and temperature inside the bubble change with time periodically. Both the pressure and temperature become higher when the radius becomes minimum. The present theoretical result is compared with data from other reference and with another theoretical model to check the validity of the present model. The calculated result approximately fits with the data of the previous studies.
Flaring systems used in oil production systems have a significant impact on both the economy and the environment as they discharge large quantities of burned gases of elevated temperature to the atmosphere that have the potential to be used in some applications. This study aims to investigate the economic losses incurred due to the combustion of gases not utilized in the Rumaila oil field in Basrah, the southern region of Iraq. Additionally, the potential to use flare gases for power generation and water desalination was studied. The mathematical models established by the U.S. Environmental Protection Agency (EPA) were utilized in this study to estimate and calculate the expected losses and used MatLab Ver. R22 to get result. The result leads to expected annular economic losses to reach $ 347,735,700. Also, the flare gases can be used to produce electric power of 1175 MW per year, it can be used for producing desalinating water of 115,911,900 m 3 for thermal desalination and 173,867,850 m 3 for membrane desalination.
A new model of bubble dynamics is constructed using linear wave equation, including effects of variation of the gas temperature inside the bubble and the liquid temperature near the bubble, and effects of evaporation-condensation of the liquid vapour at the bubble wall. The liquid is assumed water and the gas inside the bubble is only vapour (neglecting non-condensable gas). The temperature inside the bubble and the liquid temperature are numerically calculated by solving the energy equation both inside (vapour-phase) and outside (liquid-phase) the bubble (using finite difference method). The pressure inside the bubble is obtained numerically without assuming that it follows any assuming relation. The results reveal that the bubble radius, the liquid temperature, and the pressure and temperature inside the bubble change with time periodically. Both the pressure and temperature become higher when the radius becomes minimum. The present theoretical result is compared with data from other reference and with another theoretical model to check the validity of the present model. The calculated result approximately fits with the data of the previous studies.
Different modulation techniques of Nine-Level Inverter (NLI) for an Open-End Winding Induction Motor (OEWIM) is presented in this paper. The two five-level inverters are fed by both ends of open-winding induction motor. The five-level inverters are connected by cascading of four two-level inverters. This inverter topology does not neutral-point fluctuation so this topology different from neutral-point clamping inverter and this scheme does not the diode clamping to fixed neutral point. In the different multilevel sinusoidal pulse width modulations used for the proposed topology. The drive is implemented and simulation with an open-end winding induction motor and simulation results are presented.
A new model of bubble dynamics is constructed using linear wave equation, including effects of variation of the gas temperature inside the bubble and the liquid temperature near the bubble, and effects of evaporation-condensation of the liquid vapour at the bubble wall. The liquid is assumed water and the gas inside the bubble is only vapour (neglecting non-condensable gas). The temperature inside the bubble and the liquid temperature are numerically calculated by solving the energy equation both inside (vapour-phase) and outside (liquid-phase) the bubble (using finite difference method). The pressure inside the bubble is obtained numerically without assuming that it follows any assuming relation. The results reveal that the bubble radius, the liquid temperature, and the pressure and temperature inside the bubble change with time periodically. Both the pressure and temperature become higher when the radius becomes minimum. The present theoretical result is compared with data from other reference and with another theoretical model to check the validity of the present model. The calculated result approximately fits with the data of the previous studies.
Chemical additives were used in this research to improve the properties of the road subgrade layer. Cement, lime, and ferric chloride were used. Laboratory tests such as unconfined compressive strength, consistency limits, and wheel truck test were conducted. The results showed that adding these chemicals to the soil increases the ability of the soil to work, its resistance, and its durability. The optimum percentage of chemical additives that is suitable for the addition to the soil of Al-Nasiriya city were 9 %, 10 %, and 2 % corresponding to cement, lime, and ferric chloride, respectively. According to the unconfined compressive strength test and with increase curing period, which gave good results in improving the strength of the soil. As for the consistency limits, all additives reduced the liquid limit and plasticity index and increased the plastic limit, according to the wheel track test, at 10,000 passes the Rutting depth was 32 mm for natural soil, also the depths were (14, 19, and 17 mm) with chemical additives, respectively.