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Go to Editorial ManagerRecently, 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.)
The thermal performance of an absorption refrigeration system powered by solar pond heat was studied, simulated, and evaluated under the climatic conditions of Basra, Iraq. The simulation used MATLAB to solve the heat and mass transfer equations within the three layers of the solar pond (assuming NaCl as the salinity gradient medium) and linked them via a heat exchanger to the absorption refrigeration system to determine the temperatures supplied to the absorption cycle. The absorption cooling system operates on a lithium bromide-water pair and contains an internal heat exchanger between the generator and absorber with an assumed efficiency of 80%. The simulation was conducted over several months of the year, from March to October, and daily climatic variables such as solar radiation and ambient temperature specific to Basra were considered, allowing the system's performance to be evaluated under realistic climatic conditions. The objective was to evaluate the coefficient of performance (COP) of absorption refrigeration systems and demonstrate the feasibility of using solar ponds as a sustainable heat source for cooling in hot regions. The study demonstrated the feasibility of operating an absorption refrigeration system using the thermal energy stored in the lower layer of the solar pond, while maintaining good thermal stability in that layer throughout the day, especially in areas with high solar radiation, such as Basra. The simulation model was developed entirely in MATLAB using fundamental physical equations that describe each component of the solar pond and absorption refrigeration system, without relying on pre-existing components or tables. This provides greater modeling flexibility and a deeper understanding of system behavior under hot climate conditions.
In this paper, a Neural Network (NN) model system for self-organization fish school system is identified. Monitoring and data extraction from fish school video has been achieved by using image processing technique in order to generate the data suitable for parameter identification of NN model system. Data obtained have been used to identify the parameters of a model based on a black-box represented by nonlinear autoregressive exogenous model (NARX). The obtained results show that this system can be used for multi robot formation system.
An energy-harvesting hydraulic regeneration suspension system is described in this article, which includes a hydraulic motor, a spool valves, and a hydraulic cylinder. Regenerative actuators are built using a hydraulic transmission system as their inspiration. The proposed regenerative actuator is implemented in the vehicle's non-linear suspension system for a complete model. MATLAB Simulink is utilized to generate and simulate the entire vehicle's regenerative suspension system, which has force properties which are nonlinear with hydraulic actuators equations with energy harvesting from regenerative actuators. During the mathematical simulation, the effect of pressure differential on the spool valve's operation is also taken into account. The quantity of captured energy is compared to the energy expended on the active actuator and the energy generated with the electromagnetic actuator at three distinct input signals at three different pressure level (10, 30 and 50 bars) (random, sinusoidal, and square). The energy generated in the regenerative hydraulic actuator at three pressure levels behaves the same as the active actuator in terms of response, plus the highest pressure of 50 bar is closely comparable to the active system in terms of energy harvest and gradually decreases as the output pressure drops in addition to the behavior of the electromagnetic and its comparison with the wasted energy of the active system.
This study presents both experimental and theoretical investigations of an absorption refrigeration system using environmentally friendly working fluids, specifically the acetone–zinc bromide (Acetone/ZnBr₂) pair. The system was designed to operate under outdoor climatic conditions in Hilla City, Iraq, utilizing hot water as the heat source. Performance evaluation was carried out under various operating conditions, including changes in heat source, absorber, condenser, and evaporator temperatures. Experimental testing was conducted during September 2019. The results indicated that the coefficient of performance (COP) of the absorption cooling system ranged from 0.13 to 0.487, with an evaporator temperature drop of approximately 16 °C. Condensation and absorption temperatures remained below 41 °C, while the maximum driving water temperature reached 80 °C. A steady-state theoretical model was developed using the Engineering Equation Solver (EES) program, applying mass and energy balance equations to predict operating parameters such as temperature, pressure, and COP. Model predictions showed good agreement with the experimental measurements. Furthermore, the results confirmed that generator temperature has a significant influence on overall system performance.
In this paper, a theoretical study of the conventional solar-still system integrated via the design of heat recovery of air exhausted from the air conditioner condenser employing heat exchangers (WHRUs) was conducted. This study aims to improve desalination performance by compensating for the non-existence of sunlight during the night. A comparison was made between the desalination performance in the event of exposure to solar radiation and its performance in the case of exposure to the system (WHRUs). It was found that the (WHRUs) system has a minimal impact on the production of the conventional desalination rig during the night period, as the highest cumulative productivity in the presence of the (WHRU S ) reached (2.15 kg) in August. In contrast, the productivity dependent on solar radiation was (4.58 kg) for the same month, with the most significant percentage of improvement reaching (31.91 %).
The 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
The efficiency of gas turbine units is highly affected by the variation of ambient temperature. Increasing the ambient temperature decreasing the efficiency of gas turbine. Cooling the inlet air to the compressor of the gas turbine units is an essential and economical technique for improving its efficiency. Al-Rumaila gas turbine power plant was located in Basrah city, Iraq, which is characterized by its hot climates for more than six months during the year. A novel upstream inlet air cooling system was applied and tested for Rumaila gas turbine power plant. This article represents a thermo-economic evaluation of applying upstream inlet air cooling system. The analysis is based on the test results for operating single unit of Rumaila gas turbine power plant using upstream inlet air system for cooling. The test was performed during July of 2019 for 90 minutes of operation period with ambient temperature of 45 °C. The evaluation analysis shows that, the power output increased from 217.71 MW to 250.11 MW during the period test with percentage increase in power by 15%. This increase in power output led to net economic gains is approximately 1000 $/h.
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.
Lithium-ion batteries' physical properties classify them as one of the most important sources of clean energy that overcome the need for fuel usage. The rated operating temperature and its uniformity are of the main demands of Lithium-ion batteries. In this survey, several types of studies have been reviewed with the aim of understanding the thermal management systems used to control the temperature of lithium-ion batteries and their uniformity in the battery pack. They are represented by active and passive systems, as well as the hybrid system, which integrates each of the two mentioned systems into a system to obtain the best thermal performance. Active cooling systems were classified due to the type pf coolant used to air and liquid system, meanwhile passive system classified to PCM and heat pipe system. The survey reveals that the air-cooling of lithium-ion battery pack is better than the use of liquids. About 74% of the reviewed works prefer the use of active strategies. The working temperature under normal conditions should be within -20 to 60 °C, meanwhile the optimum range is 15 to 35 °C. The maximum temperature difference between batteries in the pack is preferred to be 5 °C or less.
This study proposed the using of a smart structure principle with a methodology for reducing the difference (error) between the actual position (for a semi-flexible robot) and the theoretically calculated position (for a rigid robot) on- line. The methodology depends on the interfering between the maps of the two cases; the rigid case (ideal), and the deformed case (actual) for compensation of error. According to this methodology, a class (program) was built using the visual Basic.Net; this class is called the compensation class. In this work, a two degrees of freedom articulated type lightweight semi-flexible robot was used. This robot is confined to move in a vertical plane. The smart structure system was represented by; the sensors for measuring the error deformation variables were mounted on the two links of the robot, Data acquisition (DAQ) system and the actuators of the joints. The smart structure robot systems were designed and built in this work. Also, to control the smart structure robot’s systems, software was built using Visual Basic.Net. Compensation tests have been achieved on the complete system to check the performance and results of the compensation system. This system showed a good improvement in the performance of robot for compensation and reduction in the error between the ideal position (rigid robot) and the practical position (measured position). The average error after the compensation reduced to 12.32 times in the x-direction and 21.76 times in the y-direction.
Vehicles usually consist of several essential systems. The performance of the vehicle is evaluated through the efficiency of these systems to perform their duties. The suspension system is one of these systems dedicated to absorbing shocks arising from vehicles passing over road bumps, thus reducing vibrations and achieving passenger comfort while driving. This paper presents a study on enhancing ride comfort in a nonlinear half-car model using a modified Proportional-Integral-Derivative (PID) controller. In this study a half-car model is developed considering the nonlinearities in the suspension system components. A nonlinear half-car model was adopted to increase accuracy and make the overall system closer to reality. Instead of the feed-forward conventional PID controller gains, the proposed controller gains are formed by putting the proportional and derivative gains in the feedback path while keeping the integral gain in the feed-forward path to act as an I- PD controller. The proposed controller is integrated into the model to deal with these nonlinearities effectively and to achieve the optimal performance of the vehicle body. The overall system has been developed and simulated in the Matlab Simulink environment to show the dynamic response. Simulation results demonstrate the effectiveness of the I-PD controller in improving the ride comfort and handling stability of the nonlinear half-car model by reducing body acceleration and suspension deflection. A comparison with other study has been conducted to verify the effectiveness of the proposed controller.
In this paper, a neuro-fuzzy network-based adaptive tracking controller is suggested for controlling a type of nonlinear system. Where two neuro-fuzzy networks have been used to learn the system dynamics uncertainty bounds by using Lyapunov method. Then the output of these two networks are used to build a sliding mode controller. The stability of the control system is proved and stable neuro-fuzzy controller parameters adjustment laws are selected using Lyapunov theory. Simulation case study shows that the controlled system tracking the reference model effectively with smooth control effort and robust performance has been achieved.
In this paper, a second order Sliding Mode Controller (SMC), based on Super – Twisting algorithm, Fuzzy estimator and PID controller is presented for quarter vehicle active suspensions. Because of the chattering that appeared at the output of the system when using first order SMC, second order SMC is preferred. The proposed controller has been derived in order to achieve the convergence and the stability of the system that can improve the comfortable driving and vehicles safety against different road disturbances. The Artificial Bee Colony optimization method has been utilized to find the optimal values of the proposed controller parameters. The obtained results of the simulations have been verified the efficiency and the ability of the proposed control scheme to suppress the oscillations and give the stability of the suspension system in the presence of uncertainty and different road disturbances.
Modeling and simulation of non-linear quarter-car suspension system for two air spring models (traditional and dynamic new air spring) are contrasted in terms of (RMS) sprung mass acceleration, dynamic load coefficient, the vertical displacement, they are compared. Two and three (DOF) of the mathematical quarter models are implemented in MATLAB/Simulink platform. The Ride Comfort (RC), Dynamic Load Coefficient (DLC) and Road Handling (RH) responses are evaluated as objective functions respectively considering a vehicle speed at 72 km/h and road ISO Class B. The obtained results indicate that the vertical displacement, the (RMS) of the sprung mass acceleration, and dynamic load coefficient values with the new air model system decrease by 10.7 %, 30.6 %, and 13.49 % respectively, in comparison to a tradition suspension system, this one gives more comfort and effortless handling.
This paper is concerned with the design of a new controller for active suspension system. The model is considered as a quarter-car. The presented controller depends on the fuzzy technique and NARMA-L2 linearization algorithm. The compensation system that added by the fuzzy rules improves the performance of the controller, while the neural network produces the required control signal. The new controller can achieve an improvement of the ride comfort with a reasonable value of power consumption. The mathematical analysis of the mechanical power used by the model is focused on the average and the RMS of the power supplied to the system, regardless of the frequency content of the vibration signal. The simulation results which are verified by a practical examples of road profiles, demonstrate the efficacy of the proposed controller.
In this work, a portable vibration analysis and diagnosis system is designed and constructed. The system is capable of doing most of the known analysis techniques such as FFT, time waveform, cepstrum analysis, dual channel analysis, orbit, envelope detection and other techniques. Furthermore, a new fast and efficient tracking analysis algorithm, suitable for portable instruments, has been proposed. This technique provides the data required to get accurate Bode and Nyquist plots for diagnostic analysis during machine run-up and coast-down tests. Moreover, FFT waterfall and spectrogram techniques have been included. Also, single-plane and dual-plane field balancing have been implemented in this system to execute field balancing tasks.
The purpose of this research is to control a quarter car suspension system and also to reduce the fluctuated movement caused by passing the vehicle over road bump using modified PID (Proportional Integral and Derivative) controller. The proposed controller deals with dual loop feedback signals instead of single feedback signal as in the conventional PID controller. The structure of the modified PID controller was created by moving the proportional and derivative actions in the feedback path while remaining the integral action in the forward path. Thus, high accuracy results were obtained. Firstly, modelling and simulation of linear passive suspension system for a quarter car system was performed using Matlab – Simulink software. Then the linear suspension system was activated and simulated by using an active hydraulic actuator to generate the necessary force which can be regulated and controlled by the proposed controller. The performance of whole system has been enhanced with a modified PID controller.
Nowadays, it is crucial to assess power system contingencies resulting from line outages or generator failures, as they might cause breaches of system constraints. This is a vital part of ensuring the security of modern power supplies. Another hindrance to providing electricity to consumers is the increased system losses and voltage fluctuations resulting from increased demand and diminished power generation capacity. The DG connection is a crucial subject regarding these harmful consequences. This study is focused on clarifying the effect of distribution generators (DG) on mitigating congestion in electrical power transmission lines, minimizing power losses, and enhancing the voltage profile of the Iraqi national grid system. An optimization method is used to identify the optimal size and position based on fitness indicators such as voltage, power losses, and line congestion. The PSO algorithm is executed as proposed. The outcomes illustrate the effectiveness of the proposed technique for estimating the optimal size and placement of distributed generators (DG). At the same time, it reduces congestion and improves the voltage level of the bus. The proposed technique was implemented using the MATLAB/R2018a programming language.
In this work, a new computerized measurement system for multi-plane flexible rotor balancing has been designed and implemented. This system can be used to modernize and enhance conventional low-speed balancing machines or for field balancing applications. This system adds very important features to balancing machines such as multi-plane flexible rotor balancing, high accuracy, stability, and high dynamic range. Also, the proposed flexible rotor balancing technique permits accurate balancing of high-speed rotors utilizing low-speed balancing machines or field balancing at speeds lower than the critical speeds. The proposed digital Wattmetric technique in conjugation with advanced measurement circuitry have led to significant improvement in balancing accuracy even when the unbalance signal is buried into high level of noise.
The incorporation of thermal energy storage materials (TESMs) into solar energy systems is a factor that boosts the performance of these systems. In this paper, an experimental study was addressed for enhancing the heat pipe’s thermal performance that works with an Evacuated Solar Tube Collector with Heat Pipe (ETCHP) as a solar water heater system. This is done by adding micro-zinc oxide (ZnO-MP) to the paraffin wax integrated as TESM into the evacuated tube (ET) of the system, where the evaporator section of the heat pipe is completely submerged within the micro-enhanced paraffin wax. Three experimental prototype rigs with one evacuated tube were designed, built, and tested to do the investigation. The most important parameters that have been studied in this study are the thermal resistance and the temperature distribution pattern along the heat pipe. The results show a clear indication of the decrease in the thermal resistance of the heat pipe of the proposed system compared to the system in which pure paraffin wax was incorporated. Also, it was noticed that there is a significant improvement in the temperature distribution along the heat pipe due to the improvement in the conductivity of the micro-enhanced wax compared to the pure wax.
The problem that still exists nowadays with the petrol station is the method of operation because the petrol station is currently operated manually. As it is a time-consuming process that increases manpower, other problems are related to accuracy, gasoline smuggling, fluctuations in global oil prices, sales, database management, environmental pollution and others. Traditional methods of monitoring fuel in petrol station by humans on site are unable to meet the expectations for efficiency, accuracy and cost. Therefore, this paper designs an intelligent system of three filling stations, where the three stations are simultaneously displayed on a single web application, and this IoT-based system is implemented to address all the problems. Therefore, this paper presents the design and implementation of three petrol stations in which we are going to measure the level of fuel and show it to central server. internet of things (IoT) based petrol station monitoring system is a good approach to improve monitoring efficiency and to improve management efficiency in stations remotely. simulation results presented in LabVIEW software showed the ability of the system to monitor levels of petrol, detect fire, evaporation and etc.
This paper is concerned with performance on the widely used control technique: adaptive control for synchronization between two identical chaotic systems embedded in the Master and Slave. It is assumed that the parameters of slave system are unknown. The required stability condition is derived to ensure the stability of error dynamics. Adaptive control laws are designed using appropriate parameters estimation law. The system parameters are asymptotically synchronized; thus the slave parameters can be identified. As an application, the proposed scheme is applied to secure communication system. The information signal is transmitted and recovered on the basis of identification parameters also the system is tested under the consideration of the noisy channel. Finally, through Numerical simulation results, the proposed scheme was success in the communication application.
The electronic equipment industry has developed rapidly in recent years. The amount of heat emitted from such equipment is seriously increased. Increasing the temperature of the electronic devices degrades their performance and as a final result their failure. Therefore, the requirements for an effective cooling system have become more important than ever. One of the most important methods of heat dissipation that the researchers focused on is the use of piezoelectric fans (PE). The current study reviews most of the developments that have taken place since its discovery nearly 40 years ago and focused on reducing power consumption. Most of the improvements and developments have been focused on obtaining optimal designs for these piezoelectric fans, which are used in different applications. This review clarifies the foundations and concepts of designing piezoelectric fans by comparing the data presented in previous studies. Furthermore, in the last ten years, numerical simulation has entered as an effective tool in predicting the optimal design of piezoelectric fans. The design of piezoelectric fans is in two forms, either single or multiple. The single fan system is used within a limited range of applications, as large cooling systems cannot be replaced by it. Therefore, the cooling system consisting of multiple piezoelectric fans is promising as a unique solution to effectively dissipate heat in electronic devices. The percentage of experimental studies is about 32 % while the studies of CFD is about 21 %, and the combined one is about 47 %.
Over the past years, researchers have been focusing on development the robotics and actuation due to increase demand for these applications like industrial engineering, oil industry, healthcare, aerospace … etc. This work involves the design, construction and control of the Shape Memory Alloy (SMA) actuator. The industrial actuator has many characteristics able to be measured, which have an impact on the efficiency and effectiveness of the actuator while the execution of its tasks. The most important measurable characteristics are repeatability and accuracy. The current system typically is using Nitinol (Nickle Titanium Naval Ordinance Lab), which is one of the Shape Memory Alloy that contract when applying specific heat on it, and it can be used as an actuator. This work presents SMA in the shape of a spring to operate and control the accurate position of the 2-D system which containing four SMA springs, two SMA springs for the x -axis and two SMA springs for the y - axis. The theoretical design and calculations for SMA springs have been presented to collect information about the SMA springs. In a practical manner, the SMA spring characteristic like force and displacement were collected by a test bed that was designed and constructs before making the final rig. The setting shape of the SMA spring was presented and done as per the theoretical calculations. In the rig, each axis works as a two-direction actuator, the actuator is not prone to precise position points due to hysteresis and temperature variation. The SMA spring exhibited hysteresis and imprecise pointing, for that employing PID (Proportional Integral Derivative) with tracking mode controller to compensate the hysteresis. PID control system is played a decisive role with tracking mode model that achieves the aim behind the construction of the experimental rig. Good results have been obtained presented in three cases of drawing different shapes.
In this paper, the finite-element and the matlab procedures are used for the torsional analysis of large rotor system. A large rotor system of 13 discs are considered for the purpose of analysis. As a result, the finite-element and matlab procedures are good tools for the analysis of vibration analysis and design of large rotors and their results are accurate in comparison with other literatures. The normal elastic curve and T-ω diagram obtained in this study are an effective illustration for the vibration problems in large rotors, and the developed equation for drawing the normalized elastic curve reduce the need for tabulated calculation of this curve and its very essential for vibration analysts and designers.
Human beings are facing an unprecedented rise in temperature rates not recorded for years. HVAC (heating, ventilation, and air conditioning) systems have been created and enhanced to solve this issue. Cooling load must be estimated with accepted methodologies before designing an efficient and effective air conditioning system. Companies, researchers, institutions, and others advise and develop many cooling load calculation methods. Each one of these methods has its advantages and disadvantages and may give a slightly different result for the same case. For each building, whether it was residential or commercial buildings, gyms, or shopping malls, before making the decision on (HVAC) systems to be used, both heating and cooling loads should be obtained as correctly as possible to minimize expenses as possible. Since the HVAC system consumes the most energy in an air-conditioned building, an accurate method of cooling load estimation is necessary. Consequently, an energy-efficient air conditioning system reduces greenhouse gas emissions into the atmosphere while also saving money on electricity. Two cases have been compared and studied, one in Dubai UAE, and the other in Baghdad Iraq. Three different methods, HAP, hand calculation method (CLTD/SCL/CLF), and MS-EXCEL E20 form sheet were used to compare the accuracy of the results for cooling load. Results of E20 and HAP are very close to each other with high accuracy for peak load, the big difference can be found between the CLTD method and the other two methods. The value of the maximum difference percentage was found between CLTD and E20 equals 3.28% and 7.96%, on the other hand, the lowest difference was equals to 0.3% and 1.51% between HAP and E20 results for Baghdad and Dubai respectively. Traditional and local materials came from local factories, used in buildings played a big effect on the results, which may not match those materials stated in the ASHRAE or CARRIER tables, which need to be considered in the results and calculation procedure. However, all methods have a percentage of difference but all results are within the accepted range and are applicable for practical cases. Of course, this percentage is minimal with some methods and maximum with others.
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.
Dynamic behavior of pipe conveying fluid at different cross section is investigated. Three kinds of supports are used, which are flexible, simply and rigid supports. The type effect of support on vibration characteristics and dynamic specification are studied. Also, the effect of some design parameters such as pipe material and Reynold numbers are investigated. The governing equations of motion for this system are derived using the finite element method which depends on beam theory. A finite element software (ANSYA-11) is presented to find first three eigenvalue (natural frequency) and eigenvector (mode shape) for pipe system in modal analysis. Velocity and pressure distribution are evaluated in a single phase fluid flow. A coupled field fluid-structure analysis was then performed by transferring fluid forces, solid displacements, and velocity across the fluid-structure interface. Finally the effective stresses (Von mises stress) in piping system are predicted in static analysis at various Reynold numbers, pipe material and pipe supports.
Mathematical programming techniques have been used to minimize the cost of reinforced concrete T-beam floor. The floor system consists of one way continuous slab and simply supported T-beams. The study presents a formulation based on elastic analysis followed by the ultimate strength method of design with the consideration of serviceability constraints as per ACI Code. The formulation of optimization problem has been made by utilizing the interior penalty function method as an optimization method with the purpose of minimizing the objective function representing the cost of one-meter length of the floor system. The cost includes cost of concrete, reinforcement, and formwork. The design variables considered in this study are the dimensions and the amounts of reinforcement for the slab and beams, in addition to the spacing of the beams. Many examples are solved to show the effect of these design variables on the optimum solution of the floor system. The effect on the optimum design of the compressive strength of concrete, yield strength of steel, concrete cost ratios, and formwork cost ratios has also been studied.
Sublime is considered one of the significant concepts in the recent architectural thought; it has emerged clearly as a mean of creating the highest levels of continuity in architecture, especially in contemporary architectural movements. The importance of sublime especially has emerged. Many architectural studies dealt with concept of sublime in architecture is different and various ways according to the trend of each study; this shows the importance of studying the concept of sublime in the architectural field in general. This study tries to focus on the utilization of the sublime as heritage continuity system in Islamic Architecture because it’s important in the generation of sublimity of architectural models. The paper discusses the importance of this concept and its utilization in the designs, in order to explore the particular problem which has been represented as (The absence of a specific imagination of methods and strategies for achieving sublimation).Thus the objectives of the paper has been formed by building a theoretical framework consisting of two main items of detailed theoretical field which specifies sublime as a concept ,Firstly, Then the application of the important Islamic Architectural products in Mashhad Architecture as a model, Secondly, Finally, concluding utilization of sublime as dogmatically system in Mashhad Architecture, Thirdly, after discussing the results to formulate the conclusions in the end.
Solar energy is the most suitable among all renewable energy options for competing with fossil fuels in desalination due to its ability to utilize both heat and power for the process. In this study, the Parabolic Trough Solar Collector (PTSC) for powering a Single Stage Flash (SSF) desalination unit was proposed for Basrah city climate, Iraq. The desalination system comprises two directly coupled sub-systems: the PTSC and the SSF desalination unit. The preheated feed brine water coming from condenser was used as a Heat Transfer Fluid (HTF) for PTSC, which gets heated to a desired temperature referred to as the Top Brine Temperature (TBT). The numerical simulations were performed via EBSILON professional 16.02 (2022) software. The effects of TBT, mass flowrate of feed brine water to get the desired TBT, solar collector area, and vacuum pressure inside flash chamber on the performance of the desalination system was studied. A major finding of the current study can be summarized as follows: The collector efficiency is enhanced eventually as TBT increases. The maximum values of distillate water in June are around 5.5, 4.56, 3.69, 2.75 and 1.85 kg/h for 12.408, 10.434, 8.3472, 6.26, and 4.1736 m² collector area respectively, when TBT 107 °C and vacuum pressure 40 kPa. For 1.598 m² collector area, the total distillate in the 1st of June amounted to 7.9 kg, with an average production rate of around 0.7 kg/h. The solar SSF system's productivity per solar collector unit area at 20 kPa, 15 kPa, and 10 kPa vacuum pressures was 4.7 kg/day/m², 5.3 kg/day/m², and 6.25 kg/day/m², respectively. The average Performance Ratio (PR) values are determined to be 0.694, 0.577, and 0.491 for 10 kPa, 15 kPa, and 20 kPa, respectively. These results are very acceptable when compared with an existing literature.
The rotor unbalances and misalignment in rotary machines are two major sources of vibration. rotor unbalance and misalignment is omnipresent in all rotating machinery widely used in many industrial applications, posing a serious threat to machine life and operation. The present work is an attempt to investigate the vibration characteristics (Amplitude, FFT, and time waveform) of a rotating mechanical system, which has an unbalanced rotor and misalignment. Vibration signals are acquired using an accelerometer mounted on the bearing housing nearer to the rotor. The FFT analysis of the acquired data revealed the response of an unbalanced rotor under operating conditions. Numerical analysis of the system using ANSYS portrayed the modal frequencies and mode shapes. Transient Structural analysis illustrates the response of the system to different mass unbalances. The results revealed that the magnitude of vibration characteristics significantly increases with excitation frequency and exciting force.
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.
This work presents a theoretical study on the application of low global warming refrigerants as alternative refrigerant to R 134a in a refrigeration system. The refrigerants investigated are R1234yf, R1234ze, R245fa and R227ea. The performance characteristics of the refrigeration system were predicted using mathematical models running by using EES program under different condenser and evaporator temperatures. The results show that at any working condition the R1234ze give identical performance to R134a and can be used as the best low global warming alternative refrigerant. So the compressor work with R1234ze should be designed with displacement volume more than that of R134a to overcame the reduction in mass flow rate.
This numerical study was conducted to simulate and analyze the pushout test for the new shear connector in a new steel-concrete composite system. In this system, the shear stirrups of the reinforced concrete beam are used as shear connectors when passed through holes drilled in the web of inverted steel T-section. The numerical analysis was performed by creating a three-dimensional finite element model using the finite element program ANSYS 21 student version to simulate the behavior of the new innovative shear connectors. The pushout specimens analyzed in this study have been tested experimentally by the same researchers earlier. A total of fifty-six push-out specimens were modeled and analyzed to investigate the effect of many parameters on the shear strength and slip capacity of the shear connector. The parameters studied in this investigation were the specimen dimensions (length and width), the diameter of stirrups (shear connector), the number of connectors per specimen, concrete strength, size of T-section, and shape of the specimen. The finite element analysis using ANSYS gave a good prediction of the effect of studied parameters on connector strength, the failure modes, the form and intensity of deformations in the model, and the load-slip response. The maximum difference in connector strength which was observed between the numerical and experimental results was 15 %.
In this paper, a design procedure which assumes general integer or noninteger order plant models ‘also can be unknown’ has been adopted to tune PID and fractional order PI (FOPI) controller. The design procedure depends on some specifications of frequency response of open loop system to ensure performance and robustness of step response of closed loop system. Firstly, the procedure is applied to integer order conventional PID (IOPID) controller, and then it has been extended to FOPI. Extensive simulation study has been made to investigate the performance of the obtained controllers, and also to compare between the two controllers. The simulation study has showed the validity and that the proposed controllers have good features in all of control demands, where it shows that these controllers have fast rise time with no overshoot and negligible steady state error. Also, it has showed that FOPI controller performs better than IOPID one.
In this paper, parallel optical array adder fur large-scale 2D Modified Sign-Digjt (MSD) data array is proposed. and implemented to limit the cany propagation to constant steps. The digit-decomposition-plane (DDP) representation technique is expanded to code the 2D an-ay of the MSD nwnber system. The design is based on the logical fonnul.as which are newly derived according to the fundamental parallel addition algorithm for MSD number system using the . . . . featur~ of the DDP coding technique. The optical im plementations scheme is based on classical optical elementS sucb NJ spatial light modulators, ooam combiner.;, beam splitters, mirrors, light source anays, and light detector arrays. The proposed algorithm and itS optical architecture ~ ve useful intrinsic characteristics such as ultra-high speed, constant processini time, and parallel computation on large-scale data arrays. The simulation results insure lhat the proposed arithmetic unit is worked successfully.
The finite element method is used to simulate the soil vibration behavior due to the Basrah-Baghdad passenger train and its effect on a targeted building in the Al-Ma'qal quarter, Basrah governorate. Three-dimensional dynamic elastic analyses are performed to calculate the particle velocities for a train speed of 120 km/hr. The effectiveness of screening using active (10 m long) open trench barriers with variable depth (2 m - 5 m) and width (0.4 m - 0.8 m), is being studied. For a given trench width (0.4 m), the results of the parametric study revealed a considerable effect of trench depth where the screening capability near the trench is increased by (10.4 %, 26.1 %, 36.3 %) due to a (50 %, 100 %, 150 %) increase in depth. The results are less sensitive to the variation in trench width. The screening capability of a double open (0.4 m × 10 m × 2 m) trench system was also investigated, where a mitigation improvement of (36.4 %) was achieved. The vibration mitigation using single and double trench systems, filled with (40 %) rubber content mixture, was also analyzed. It is concluded that using the additional passive trench increases the mitigation of the single system by around 19.1 %. An important finding is that the (40 % rubber + 60 % native cohesive soil) mixture proved to be a good filling material, since the infilled-trench systems produced comparable screening ratios to the open systems, where (97.7 %) and (85.4 %) were accomplished for the single and double systems, respectively.
The effect of different dosages of the high range water reducing admixture–additive- (HRWRA), the commercially polymeric material (Plastocrete-N), on the corrosion resistance of embedded steel in concrete exposed to chloride solution in the absence and presence of sulfate ions was studied. In the present study, four levels of polymeric material (Plastocrete-N) (0.125%, 0.250%, 0.375%, and 0.500% by weight of cement) were used to prepare HRWRA treated concrete. The concrete specimens exposed to chloride and chloride–sulfate solutions at concentrations of (3.5% NaCl and 5% Na2SO4), at ambient temperature. The electrochemical behavior of steel in both reference and HRWRA concretes was studied under the effect of corrosive environments using corrosion measurement systems such as: a) half – cell potentials measurement system and b) accelerated corrosion test system. The results showed that a longer time of corrosion initiation (180 day) observed with 0.500% HRWRA containing concrete compared to other different HRWRA percentage including the reference concrete. It was concluded that the use of 0.500% HRWRA provided superior protection to steel reinforcement in concrete that subjected to corrosive environments. Furthermore, the steel with 0.500% HRWRA was subjected to corrosion test by mass loss, it is evident that a reduction in mass loss by about 90.2% and 85.2% in both solutions, respectively.
There is a vacuum created when water goes past a pipe constriction. Air may be pulled into the main flow by drilling a hole in the pipe near where the vacuum happens. Venturi aerator is an example of the application in action. A vacuum is formed at the suction holes of the Venturi tube when there is a small difference in pressure between the input and output sides. To demonstrate the link between total flow rate and Venturi aerator performance, a Venturi aerator (model 1584) was introduced at a specific point in a Biopipe system. For this purpose, a physical model on a pilot scale was constructed and installed in an existing sewage treatment plant. Dissolved oxygen concentrations were measured at four locations along the Biopipe at different values of wastewater flowrates. The study results showed that raising the total flow rate increased the amount of air injected by the Venturi aerator. When the total flow rate was less than 4 m 3 /hour, the Venturi aerator stops sucking air and produces negative consequences.
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 30 o N. 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.
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.
The aim of this work is to experimentally study the influence of fiber prestress and curing temperature on the tensile and flexural properties of carbon fiber-epoxy composite. Adaptive Neuro-Fuzzy Inference System model was used to predict the effect of fiber prestress and curing temperature on the tensile strength, tensile modulus, flexural strength and flexural modulus of carbon fiber-epoxy composite. It was found that, the best membership functions for predicting the tensile strength, tensile modulus and flexural modulus are Gaussian membership functions with 4 number of membership function, and for predicting the flexural strength are generalized bell membership functions with 4 number of membership functions. From the comparison between the experimental and predicted results of carbon fiber-epoxy composite properties, it is found that the prediction results of this model show a good agreement with experimental results.
One of the major problems in industry are new welding trainees cost, it drains the budget of many companies, particularly in industrialized countries, through raw material costs for preparation, welding wires, electric and fumes in addition to time spent. Recently a new technique was appeared; it is called virtual welding training system (VWTS) to reduce the training cost. In the present work a VWTS technique was built, a simulation of electrode motion is upgraded by using LVDT to represent the welding arc length while a DC motor with gearbox connect to the steel rode is used to represent welding electrode consumption. A 2D graphs with touch screen monitor are used to represent welding process. All sensors were calibrated to generate a VWTS. Accepted results obtained in training new welding trainees in the shielded metal arc welding (SMAW) training.
This paper introduces a radial distribution feeder protection scheme based on certain features extraction from current signals measurement at the substation. The features are captured using the discrete wavelet transform (DWT). Two digital signals processing methods are used to introduce those features to the 1) fault detection 2) identification and 3) localization schemes; the first one is the energy method and the second one is the root mean square method. For the purpose of fault type identification, two systems are tested and compared, a Fuzzy Inference System (FIS) and Artificial Neural Network (ANN). Fault location scheme is then built based on ANNs. An effort is made to reduce the computational burden and the speed of detection provided by the fault detection and identification schemes. Since the short circuit faults are the most likely types of faults that can occur in power systems, the ten types of these faults taking into account different fault resistances are simulated in MATLAB environment and the protection scheme is built based on the idea of over current. The power quality disturbances such as switching transient events on the feeder is also taken into account in order to build a reliable and secure protection scheme.
A mathematic model is presented for solar updraft tower power plant with water-storage system. This model is developed to evaluate the effect of geometrical parameters of the solar tower power plant and thermal storage system as well as the wind velocity on the power production of the plant. The analysis based on variable solar incident radiation along the day. The results show that the tower tall, the tower diameter, the wind velocity, and the collector diameter have a significant effect on the power production while lhe thickness of the water-storage layer is shifted the peak value of the output power far away from mid-day and more smoothing tha output power curve. The results are compared with other model and experimental data. A good agreement is obtained.
This paper presents an implementation of an independent control of two-mechanically coupled Permanent Magnet Synchronous Motor (PMSM) fed by two Space Vector Pulse Width Modulation (SVPWM) inverters in a separate mode and in the event of failure one leg of one inverter, fault tolerant mode. In a fault tolerant mode, the two motors can operate in an independent control strategy from one inverter with five legs to maintain a constant output coupled torque. The Field Oriented Control (FOC) strategy is used to control the stator current of the two motors through two separate paths. Such application is used in the field of a coupled torque produced by multi-motors such as in subway applications. The whole system is simulated in Matlab /Simulink and the simulated results show a stable and robustness system which can maintain a constant developed torque with a velocity reaches to the rated under fault tolerant operation.
Tn this paper, a hierarchical phoneme recognition system is proposed. The hierarchical approach is applied here to recursively partition the recognition problem into smaller and smaller sub-problems those are independently handled at the di~tinct nodes of the hierarchy. The nodes are individually set to chara~erize different properties of the input phoneme, or more precisely to make separate d~isioos on its pertinence to the different reference subgroups of phonemes. The full characteri:zation of the input phoneme is achieved by traversing some root-to-leaf path through the hierarchy. The relationships between the different features of phonemes and their pertinence to the different reference subgroups. are to be objectively characteriz.ed ttnd optimized here. This involves specifying the decisive subset of features for each pertinence decision and neglecting the remaining features those are irrelevam to (or probably have negative effect on) that decision, at each node of the hierarchy. The optimization applied through the feature election process here, is not aimed at reducing the amount of feamres to be used in the recognition process, for the purpose of decreasing the time-complexity of the systcn1, but, is interested in enhancing the decision making accuracy of the system by avoiding the misleading features.
The solar chimney power plant is one of the modern models studied on the world. This study presents an engineering and numerical analysis of solar chimney with different parameters. Also, it studies the comparison of two collector base shapes(circular and hexagonal) depend on the five storage material types and their effects on the heat transfer, velocity, efficiency, etc. inside the solar chimney system by considering the solar array intensity equations and the energy equation to calculate the heat transferred and stored by applying the laws of CFD. The finite volume method is used to analyze the geometry physical model by applying a commercial Fluent 6.3 code with Gambit 2.3. The obtained results show that the efficiency of solar chimney is increased by increasing the area of solar glassed collector with circular base shape than the others of polygonal or rectangular one because the circular was covered large area of system. So, the circular ground collector shape for thermal storage is the favour because it is the better to increase the velocity of entering air and to increase the efficiency of turbine. In addition to that the black Pebble storage plate is the better material for heat storage which is convected to air passed for operation of turbine than the other types aluminum, tar, copper and steel seriously.
A household refrigerator represents an essential device for all houses nowadays. The electric energy consumed by the refrigerator and the fluctuation of the temperature inside the fresh food cabin is the main two problems affecting its performance. Incorporating phase change material (PCM) inside the refrigerator is one of the solutions for the previous mentioned problems. In the present study, a water PCM is added to the cabinet of 220-litters double door refrigerator. The PCM (0.5 ml of water) is added at three different locations, touch the front of the evaporator part inside the cabin, touch the rear of the evaporator part in the cabin, and far away from the evaporator part inside the cabin. The location of the PCM determines how much energy is released and stored from the evaporator. The use of phase change material (PCM) touch to the evaporator increases the rate of heat transfer due to the conduction method being used throughout the whole heat transfer process from the evaporator to the phase change material (PCM), which raises the refrigeration system's COP (coefficient of performance). The experimental test period is 24 hours for each day. Firstly, the refrigerator is tested without using PCM, and the power consumption, the temperatures at different points for the refrigerator, suction pressure, discharge pressure, the ambient temperature, and the time on period and time off period of the compressor are measured. Secondly, for same testing period all previous parameters are measured with using PCM at different locations inside the refrigerator. The results show that, adding the PCM (water) behind the evaporator led to increase the COP by 21.97%, increase the compressor off time by 73 minutes, reduction in power consumption of 14.4%, decrease of exergy losses of the system by 8% and temperature fluctuation reduced inside the fresh food cabin, that enhance the quality of stored food. Adding the PCM front the evaporator improve the previous parameters but less than that of the first case. The third location, adding the PCM far away from the evaporator has no improvement on the refrigerator's performance.
An-Najaf Province is one of the most important cities in Iraq and is experiencing rapid population growth and continuous expansion of infrastructure, including residential buildings, hotels, bridges, and commercial centers. This study aims to establish a spatial database of gypsum content in soils across An-Najaf Province, including Najaf city center and Al-Kufa city, to support safe geotechnical design. A total of 464 boreholes and in situ test records were analyzed using Geographic Information System (GIS) techniques to assess the spatial variability of gypsum content. The adopted methodology comprised four main stages: data collection, georeferencing of geotechnical data, application of interpolation methods, and map generation. Nine geotechnical distribution maps were produced for depths of 0, 2, 4, 6, 8, 10, 12, 14, 16, and 35 m. Results indicated that the 0–4 m depth layer is predominantly moderately gypsiferous, with gypsum content ranging between 10–25%. The 4–8 m depth layer is mainly slightly gypsiferous, with values between 3–10%, while deeper layers from 8 to 35 m are very slightly gypsiferous, with contents ranging from 0.3–3%. These findings show that the near-surface layers (0–4 m) exceed the allowable gypsum content limit of 10%, which may pose potential risks to construction stability, particularly in combination with the high groundwater levels in the Najaf region.
Conventional Refrigeration Systems (VCRS) are the most commonly used in industrial buildings and facilities. Conventional refrigeration systems are among the most energy-consuming sources in addition to causing more environmental problems and gas emissions, such as hydrocarbons (HCs) and hydrochlorofluorocarbons (HCFCs), are known to contribute to global warming and ozone depletion. Absorption Refrigeration Systems (VARS) are a good alternative to conventional refrigeration systems because they use low-grade heat sources and operate with environmentally friendly liquids. The most important of these heat sources is the heat wasted from engines, industrial processes and many other sources. The global objective of the study is a literature review on the different ways to operate the absorption refrigeration system using waste heat in engines that include exhaust gases and engine cooling water as well as renewable energy that includes solar energy. Reviews of the literature have demonstrated how the absorption refrigeration system can be used and operated using a variety of thermal sources. This study also supports the usage of ecologically friendly chillers to provide air conditioning and refrigeration, as it shows these systems have a lower performance coefficient when compared to conventional refrigeration systems.
The aim of this research is to predict the shrinkage defects in Al-Si castings by determination the suitable parameters and techniques which can be applied in casting simulation system. Also, it aims to specify the role of silicon content in amount, morphology, and distribution of these defects. The Numerical solution has been carried out using an explicit 3-D finite difference method for the given system of the casting and a mold. Additionally, an experimental casting of the studied samples was achieved. It was found that the shrinkage porosities increased with increasing the silicon content up to 7%, so at this peak, they spread in alt cast regions and cannot be predicted. The low silicon alloys suffered from only the shrinkage cavities defects that can be predicted by mapping the solidus time contours. Finally, it was concluded that the critical temperature gradient value of the porosities development in the eutectic (AI-12%Si) alloys was 1.3°C/cm.
This paper presents an approach for the recognition of off-line handwritten numeric strings using genetic algorithm. The proposed scheme is divided in two parts. The first part is remove the image noise, then the vertical projection is used to segment the numeric strings at isolated digits and every digit will be presented separately to the second part. The second part using improved genetic algori_thm to recognize isolated handwritten digit. The result of the recognition of the numeric strings will display at the exit of the global system.
An intelligent and anticipatory speed controller for internal combustion engines was designed theoretically and examined experimentally. This design was based on the addition of a torque loop to the main speed loop. The model can sense the external load with the help of a load cell and send this signal to a soft computing unit for analysis and processing. This scheme will improve the ability of anticipation of controller since it treats the factors that affect the speed, not the speed itself. The experimental design was implemented using two types of actuating techniques; an intelligent throttling actuator and an intelligent injection actuator. The signal was analyzed by using intelligent techniques such as fuzzy logic, neural network and genetic algorithm. The experimental data were used to train the neural and the Adaptive Neuro–Fuzzy Inference System. The comparison of the results obtained in this work with other available models proved the efficiency and the robustness of the present model.
In this paper induction motor and its direct torque control are simulated and a speed estimator scheme based on wavenet (WN) theory has been developed and compared with the actual speed. The wavenet speed estimator inputs are a single line current and the state of the torque comparator output which are trained to follow the relationship between the motor current and the rotor speed. To ensure the validity of this scheme, the estimated speed is compared with a speed estimated from a conventional model reference adaptive system (MRAS). The operation of direct torque control (DTC) drive with the actual speed and the estimated wavenet speed as a feedback signal are simulated and compared. The results show that the wavenet method is effective for rotor speed estimation.
The surge tank is one of important control devices in reducing water Hummer effect on distributed network piping system and hydropower stations. An experimental study was conducted into a simple surge tank of 0.044 m in a diameter with upstream constant head reservoir of a height, 0.881 m and a water transporting pipe of a size 0.0202 m. Results indicate that rapid closure of a downstream valve causes under-damped stable oscillation in a surge tank. Experimental response agreed well with theoretical results when friction factor is considered to be variable, but with 85 % increases in settle time and more oscillations when constant friction factor is recognized at initial value before valve closure. Doubling surge tank area does not improve the dynamics properties; otherwise, Thoma area must be avoided for small sizes. Comsol multiphysics software 3.5 is used to deal with the dynamics of the surge tank numerically.
The present work investigates the effects of drinking water on the erosion- corrosion rate and Vickers hardness of (Al-Si) and (Al-Mg-Si). (Al-Si) alloy Which is well-known as casting alloy with high wear resistance, low thermal expansion coefficient, good corrosion resistance and improved hardness at a wide range of temperatures While (Al-Mg-Si) alloys have good formability, weld ability, machine ability and corrosion resistance. The alloys specimens which are used for piping and containing water and carbonated water were exposed in erosion- corrosion system in factories by using drinking water type AQUAFINA as exposure media for different exposure time (1-30)h. to measure the erosion-corrosion rate. The results show that there is small different in the rate of corrosion, moreover (Al-Mg-Si) alloy have high resistance to erosion-corrosion in drinking water due to the consisting of (Mg2Si) phase which is precipitate as fine particles due to resist dislocations movement lead to high corrosion strength and the (Al-Si) alloy have high Vickers hardness at natural aging due to the present of high ratio hardening silicon element.
During the pouring of concrete deck, the installation of external bracing between the inner and outer girders may be necessary when the bridge has sharp curve in order to control the deflection and rotation of the girders. However, it is important to minimize the number of external bracing members, as they have expensive cost and they also have opposite effects for the fatigue features of the steel tub girders. The analysis of curved box girder bridges is carried out numerically by the use of finite element method through (ANSYS 19.2) software. The curved box girder with the intermediate external diaphragms was modeled and the analysis was carried out for many parameters like external bracing sections, girders with or without concrete deck, girders with end diaphragms or without them. The study concluded that ANSYS program has a good ability in evaluating the external bracing force comparing with code equations.
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.
The present work investigates the effects of drinking water on the erosion- corrosion rate and Vickers hardness of (Al-Si) and (Al-Mg-Si). (Al-Si) alloy Which is well-known as casting alloy with high wear resistance, low thermal expansion coefficient, good corrosion resistance and improved hardness at a wide range of temperatures While (Al-Mg-Si) alloys have good formability, weld ability, machine ability and corrosion resistance. The alloys specimens which are used for piping and containing water and carbonated water were exposed in erosion- corrosion system in factories by using drinking water type AQUAFINA as exposure media for different exposure time (1-30)h. to measure the erosion-corrosion rate. The results show that there is small different in the rate of corrosion, moreover (Al-Mg-Si) alloy have high resistance to erosion-corrosion in drinking water due to the consisting of (Mg2Si) phase which is precipitate as fine particles due to resist dislocations movement lead to high corrosion strength and the (Al-Si) alloy have high Vickers hardness at natural aging due to the present of high ratio hardening silicon element.
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.
The present work investigates the effects of drinking water on the erosion- corrosion rate and Vickers hardness of (Al-Si) and (Al-Mg-Si). (Al-Si) alloy Which is well-known as casting alloy with high wear resistance, low thermal expansion coefficient, good corrosion resistance and improved hardness at a wide range of temperatures While (Al-Mg-Si) alloys have good formability, weld ability, machine ability and corrosion resistance. The alloys specimens which are used for piping and containing water and carbonated water were exposed in erosion- corrosion system in factories by using drinking water type AQUAFINA as exposure media for different exposure time (1-30)h. to measure the erosion-corrosion rate. The results show that there is small different in the rate of corrosion, moreover (Al-Mg-Si) alloy have high resistance to erosion-corrosion in drinking water due to the consisting of (Mg2Si) phase which is precipitate as fine particles due to resist dislocations movement lead to high corrosion strength and the (Al-Si) alloy have high Vickers hardness at natural aging due to the present of high ratio hardening silicon element.
Smart prostheses hands have seen vast advancement in recent years. Amputees with upper hand loss have better access to intelligent prostheses that help them with their daily life activities. Smart prostheses however are still in development and have a few disadvantages, such as being expensive, complex, require training and being error prone in some cases. In this paper a simple, cost effective, practical upper limb prosthetic device is proposed that uses pressure sensors to acquire the action intent from the amputees. The pressure sensor serves as input signal to the Control Unit (CU). Using a selector keyboard, the amputee can choose between five predefined movements. The advantages of the proposed system compared to other prostheses using EMG, EEG, Voice is design simplicity and cost. The approximate cost of the proposed prosthetic hand is less than 200$. In addition, some of the complexities and error prone properties of the other alternatives are avoided and less probability of use fatigue is achieved.
This paper presents design and modeling of a compact reconfigurable quarter wavelength slot antenna compatible with the portable devices of the 5GHz wireless local area network (WLAN) applications. The concept of the transverse resonant method which is used for the transmission lines is utilized for modeling the proposed slot antenna. A PIN diode is used to switch the antenna operating band from the lower unlicensed indoor 5GHz WLAN band (5-5.3) GHz to the upper one (5.7-5.9) GHz and vice versa. Another PIN diode is attached to the feed line to provide suitable matching stub length for each operation mode. Furthermore, the shape of the radiating slot of the proposed antenna is modified to provide an omnidirectional radiation pattern in the H-plane suitable for the portable gadgets of the WLAN system. The measurements are in well agreement with the simulated results, and they verify the precision of the suggested model and the enhanced matching characteristics for the two operation modes of the proposed antenna.
The use of fiber-optic links as the connecting media in wireless microcellular networks can be provide uniform radio coverage to spatially distributed mobile users in cost effective manner. This paper investigates theoretically the performance of fiber distribution system for mobile phone networks that uses a single high power Nd:YAG laser in the base station and shared by many microcells. Analytical expressions are derived for the bit-error-rate (BER) floor characteristics and optimum operating conditions. The results indicate clearly that the laser power can be reduced significantly when the modulation index is optimized.
The aim of the present study is to perform analytical simulation for the single-effect LiBr- water absorption refrigerating system (ARS) in order to scan for all possibilities of operating the cycle among most available operating variables to obtain the best performance and determine what are the proper parameter needed to be changed so that the refrigerator can operate using ambient air instead of water and cooling tower accessories to dissipate the hear at the condenser and absorber. The COPs of the cycle was obtained as a function of the different temperature of the cycle and solution concentration. The performance characteristics of the cycle were examined by changing the temperature of the heating source supplied at the generator, the temperatures at the condenser, absorber, and evaporator. It can be concluded that the concept of air cooled absorption chiller is feasible with coefficient of performance of 0.43 10 0.79 depending on the evaporator temperature for any cooling capacity in some applications, where the chilled water supply temperature is not necessary to be too cold.
Plants and agriculture are important in Iraq and the world because they are among the essential basics of life; their importance lies in several fields, such as industry and food. Plant diseases are the first direct influence on plant production and the Iraqi economy. The primary contribution of this work is developing an efficient early warning system for tomato plant diseases based on readily available environmental data, demonstrating the usefulness of machine learning methods in real agricultural environments. This research investigates the use of artificial intelligence (AI) for the early prediction of tomato diseases in Iraqi agriculture, based on temperature and humidity data collected from Salah al-Din Governorate. Two major diseases were studied: Tomato Yellow Leaf Curl Virus (TYLCV) and late blight. The data were pre-processed and used to train predictive models, including linear regression and Random Forest Regressor (RFR). Results show that RFR outperformed linear regression, achieving a lower Root Mean Square Error (RMSE) of 0.053852 and a Mean Absolute Error (MAE) of 0.45000, indicating its superior accuracy in predicting disease occurrences.
The present work investigates the effects of drinking water on the erosion- corrosion rate and Vickers hardness of (Al-Si) and (Al-Mg-Si). (Al-Si) alloy Which is well-known as casting alloy with high wear resistance, low thermal expansion coefficient, good corrosion resistance and improved hardness at a wide range of temperatures While (Al-Mg-Si) alloys have good formability, weld ability, machine ability and corrosion resistance. The alloys specimens which are used for piping and containing water and carbonated water were exposed in erosion- corrosion system in factories by using drinking water type AQUAFINA as exposure media for different exposure time (1-30)h. to measure the erosion-corrosion rate. The results show that there is small different in the rate of corrosion, moreover (Al-Mg-Si) alloy have high resistance to erosion-corrosion in drinking water due to the consisting of (Mg2Si) phase which is precipitate as fine particles due to resist dislocations movement lead to high corrosion strength and the (Al-Si) alloy have high Vickers hardness at natural aging due to the present of high ratio hardening silicon element.
This paper presents an extensive review of energy harvesting from the column vibrations of wind turbines under the influence of wind. The study investigates the underlying theories, mechanisms, and potential applications of such a system. By tapping into the vibrational energy otherwise dissipated in wind turbines, the study proposes an innovative approach to enhance renewable energy generation. Furthermore, the potential benefits of the technology, such as powering remote sensors, vibration damping, structural health monitoring, and increasing wind turbine efficiency and lifespan, are discussed. While the study acknowledges the promise of such an approach, it also emphasizes the need for further research to optimize and integrate these systems effectively into the renewable energy landscape.
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.
The present work investigates the effects of drinking water on the erosion- corrosion rate and Vickers hardness of (Al-Si) and (Al-Mg-Si). (Al-Si) alloy Which is well-known as casting alloy with high wear resistance, low thermal expansion coefficient, good corrosion resistance and improved hardness at a wide range of temperatures While (Al-Mg-Si) alloys have good formability, weld ability, machine ability and corrosion resistance. The alloys specimens which are used for piping and containing water and carbonated water were exposed in erosion- corrosion system in factories by using drinking water type AQUAFINA as exposure media for different exposure time (1-30)h. to measure the erosion-corrosion rate. The results show that there is small different in the rate of corrosion, moreover (Al-Mg-Si) alloy have high resistance to erosion-corrosion in drinking water due to the consisting of (Mg2Si) phase which is precipitate as fine particles due to resist dislocations movement lead to high corrosion strength and the (Al-Si) alloy have high Vickers hardness at natural aging due to the present of high ratio hardening silicon element.
Monitoring the health of rotating machinery is essential to ensure system safety, achieve cost savings, and enhance overall reliability. The requirement for a reliable and clear method of identifying defects has prompted the development of several monitoring techniques. They utilize vibration, measurement of the motor's current signature, and acoustic emission data in the process of condition monitoring. The MFS (machinery fault simulator) equipment was used to determine bearing faults using vibration signal analysis. MFS conducts simulations and investigations of many bearing issues, including those occurring in the inner race, outer race, and balls. An accelerometer (type B & K 4366) was connected to a data acquisition device (IDAC-6C) to record vibration signals under different operating conditions. Furthermore, a tachometer equipped with an LCD display is employed to measure the rotational speed. Four types of defects in ball bearing (Koyo 1205C3 type) were studied, the slot in outer race with size 0.196 mm, the slot in inner race with size 0.191 mm, in ball with size 0.196 mm in additional to compound defect. In this paper, spectral correlation technique was employed to detect defects in ball bearings running at varying speed, along with spectral coherence and the corresponding Enhanced Envelope Spectrum (EES) in frequency-order domain and order-order domain. The results show that the adopted methods, that are used to analyze the real vibration signals for diagnosis the defected ball bearings, are suitable, accurate and less processing time for varying speed. The processing time of the FastACP method used to analyze the signals in order- order domain is less than that of the adopted method in the frequency-order domain for any defect type. Overall, using the FastACP method in the order-order domain significantly reduced processing time by approximately 27% compared to the adopted method in the frequency- order domain under varying speed conditions.
This paper considers the neural network based PID controller. The learning and generalization properties of neural network are utilized in improving the performance of a conventional PID controller. Two different schemes are introduced. Both schemes are studied and their performances are comparatively evaluated on an example for uncertain system.
Solar energy can only be used when it's sunny outside. Therefore, solar heating is only efficient during the day and decreases at night or on overcast days. Consumer energy needs have a distinct seasonal structure, and solar energy cannot completely meet those needs. In order to satisfy customer demand, energy storage is essential. In order to maximize the use of solar energy and to increase the energy and efficiency of the solar absorption system, superior thermal properties of sophisticated materials, such as phase change materials, are important [1]. In the current study, 20 kg of phase change material (PCM) is integrated with solar water heating and fed into a storage tank to enhance the solar water heating efficiency. Helical coil heat exchangers were added to the storage tank as an external load. The trials were conducted in four separate months (September 2021, April, May, and June 2022) that were chosen on the first day. The effectiveness, heat gain, and significance of the phase change material in increasing heating efficiency throughout the day were studied using a range of variables, including water volume flow rate (2, 3, 4, 6, and 8 L/min) and inlet water temperature (25, 30, and 35 °C). The results showed that, given an initial temperature of 25 °C, the daily efficiency range, was 0.58 to 0.65, and that the daily final outlet temperature was enhanced outlet temperature over 65 °C. Additionally, on all test days, the heat released by the phase change material was audible in the evening and increased the utilization time.
This study presents a speed control design for switched reluctance motor (SRM) drive based on PID controller. The applications of Switched Reluctance Motors (SRMs) have being increased day by day, but this type of motors represents a highly nonlinear system, therefore there are a lot of difficulties in modeling and controlling them. We have proposed a non-linear mathematical model of a four phases 8/6 poles SRM then simulated it through Simulink/Matlab facilities. The whole control mechanism consists of a hysteresis current controller to minimize the torque ripple and a PID speed controller. The control design results are then validated in real-time by Simulink/Matlab software package.
This paper is concerned with a stress analysis in a bearing under unbalanced fon:es of the jownal. Some aspects of mathematical modeling of rotating structW'Cs were considered. "Finite Element Method'' is fom1ulated for modeling rotating structures. As an application, a test rotor mounted on two-lobe hydrodynamic bearings is presented. Unbalance response calculations for various unbalance magnitudes are ca1Ticd out in the bearing location. The bearing coefficients were found at rotational speed of 4,000 rpm. An accurate identification of bearing force parameters, i.e. stiffness and damping coefficients is presented by a classical linearized model. The bearing support forces in tlexiblc rotor-bearing systems are presented as a function of unbalance response of the journal. The calculation of the bearing stress due to rotor w1balance are carried out using ANSYS. The ANSYS program gives a good aids in understanding the ~tress analysis in the bearing under the action of journal rotation.
The Internet of Things (IoT) connects everyday objects to the Internet by integrating a vast network of interconnected smart devices into residential and commercial settings. When the Industrial Internet of Things (IIoT) changed how industries work by connecting and communicating devices and systems in industrial environments, these devices linked to the Internet gathered information from their surroundings, processed it, and sent it safely. Industry 4.0 transforms transportation and manufacturing industries by producing smart devices for total automation. This system has a substantial application in predictive maintenance. Predicting disasters in dangerous areas aids in managing safety and decreasing damage. In this paper, presented review for the integration of Cyber-Physical Systems (CPS) and IIoT in smart cities is fundamentally transforming urban services and infrastructure. Smart cities leverage technology to enhance inhabitants' quality of life, foster sustainability, and streamline municipal governance. Artificial intelligence is applied with IIoT's production and analysis data to generate speedier outcomes. The article discusses IIoT uses, supporting technologies, growth issues and how to fix them, and suggestions for growth and better performance by limitless potential, including better manufacturing, greener electricity production, self-regulating structures, and smart cities that can modify traffic patterns to reduce congestion.
Constructed wetlands are engineered systems used for wastewater treatment with the objective of reusing water under controlled conditions by mimicking natural treatment mechanisms involving porous media, plants, and microbial communities. This study investigates the performance of a horizontal subsurface flow constructed wetland, where wastewater flows through a gravel bed and vegetation roots, allowing contact with biofilm developed within the wetland substrate. To evaluate treated water quality, physical, chemical, and biological parameters were measured. Field results demonstrated that pollutant removal efficiency increased with detention time. After 3, 4, and 6 days of treatment, average removal efficiencies were 47.7%, 53.2%, and 77.5% for COD; 45.1%, 52.8%, and 64.4% for total nitrogen (TN); and 55.4%, 58.8%, and 72.2% for ammonium (NH₄), respectively. Nitrate removal averaged 19.41% after 3 days. These findings confirm that the horizontal flow constructed wetland system is effective in reducing key wastewater pollutants.
A linked simulation-optimization model for obtaining the optimum management of groundwater flow is presented in this research. (MODFLOW, 98) packages are used to simulate the flow of the groundwater system. This model is integrated with an optimization model which is based on the genetic algorithm (GA). Three management cases were undertaken by running the model with adopted calibrated parameters. In the first case found the optimum value of the objective function is (0.32947E+08 m3/year), in other words, the pumping rates could be raised to nine times the current pumping rates, with a highest decline in the hydraulic heads of groundwater compared with initial hydraulic heads reached to 6 cm. In a second case twenty six wells out of thirty five can be operated with "on/off" status associated with each well to obtain the maximum value of pumping rate. In third case is allowed to move a location of well anywhere within a user defined region of the model grid until the optimal location is reached. The optimum value of objective function in third case is (0.35539E+08 m3/year) with 8% increasing of the pumping rates compared with the first case. This is due to the random distribution of existing well locations.
The present work investigates the effects of drinking water on the erosion- corrosion rate and Vickers hardness of (Al-Si) and (Al-Mg-Si). (Al-Si) alloy Which is well-known as casting alloy with high wear resistance, low thermal expansion coefficient, good corrosion resistance and improved hardness at a wide range of temperatures While (Al-Mg-Si) alloys have good formability, weld ability, machine ability and corrosion resistance. The alloys specimens which are used for piping and containing water and carbonated water were exposed in erosion- corrosion system in factories by using drinking water type AQUAFINA as exposure media for different exposure time (1-30)h. to measure the erosion-corrosion rate. The results show that there is small different in the rate of corrosion, moreover (Al-Mg-Si) alloy have high resistance to erosion-corrosion in drinking water due to the consisting of (Mg2Si) phase which is precipitate as fine particles due to resist dislocations movement lead to high corrosion strength and the (Al-Si) alloy have high Vickers hardness at natural aging due to the present of high ratio hardening silicon element.
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.
This paper deals with the modeling and control strategics of the motion of wheeled mobile robot. The model of the mobile robot has two driving wheels and the azimuth and velocity are dependently controlled by two PID controllers. The PID controller is one of the earliest and famous industrial controllers. It has many advantages: It is economic, simple easy to be tuned and robu.~t. The tuning of these controllers is governed by system nonlinearities and continuous parameter variations. lbis paper deals with the optimal design of a PID controller for path tracking of mobile robot by using genetic algorithms (GA). The designed controller is tested for different paths.
The present work investigates the effects of drinking water on the erosion- corrosion rate and Vickers hardness of (Al-Si) and (Al-Mg-Si). (Al-Si) alloy Which is well-known as casting alloy with high wear resistance, low thermal expansion coefficient, good corrosion resistance and improved hardness at a wide range of temperatures While (Al-Mg-Si) alloys have good formability, weld ability, machine ability and corrosion resistance. The alloys specimens which are used for piping and containing water and carbonated water were exposed in erosion- corrosion system in factories by using drinking water type AQUAFINA as exposure media for different exposure time (1-30)h. to measure the erosion-corrosion rate. The results show that there is small different in the rate of corrosion, moreover (Al-Mg-Si) alloy have high resistance to erosion-corrosion in drinking water due to the consisting of (Mg2Si) phase which is precipitate as fine particles due to resist dislocations movement lead to high corrosion strength and the (Al-Si) alloy have high Vickers hardness at natural aging due to the present of high ratio hardening silicon element.
The analysis of raw domestic sewage has a greater importance for design of an effective and economic rational sewage treatment. The objectives of this study are to determine the chemical, physical and Biochemical characteristics of raw domestic sewage for Basrah city. Results show that; the strength of Basrah raw domestic sewage can be classified as a strong strength concentration wastewater due to high levels of organic loading rate BOD5 , COD. Also, it can be seen a very high concentrations of TDS , CL- and increasing in EC levels above the typical limits due to the salinity of domestic water supply in Basrah. High concentrations of oil and grease were found as result of misuse of the sewerage system. While the values of pH, temperature, nutrients and the number of FC are within the typical acceptable limits.
This paper presents a PWM AC/DC buck converter circuit incorporating a frontend rectifier followed by a DC/DC converter. Two transistors are used as a main and auxiliary switches. The proposed circuit provides zero-current (ZC) turn ON and zero-current/zero-voltage (ZCZV) turn OFF to the two transistors, besides zero-voltage turn ON to two diodes. Numerical methods are used to analyse and determine the performance of the converter system. A feed forward technique is employed to improve the performance of the converter over a range of output power.
In this research, the mechanical properties were studied from the experimental, theoretical, and numerical aspects of the sports prosthetic foot for the purpose of providing a sporty prosthetic limb with high performance, easy to use and an appropriate financial cost to use by amputees who have lost their lower limbs (amputation below the knee) in practicing their sports activities and overcoming physical disability. The dimensions of the blades were calculated based on side profiles from European patent specifications. The chosen fibers have high strength, are light in weight, and can be purchased for a lower price than the materials that are used in the production of the sports prosthetic feet that are already on the market and are produced by specialized companies such as Ottobock and Ossur. Six laminates of the composite material consisting of matrix orthocryl lamination 80:20 pro reinforced with different fibers (Kevlar fibers, carbon fibers, glass fibers, and perlon fibers) were fabricated in the form of rectangles using the vacuum system and then cut to the required dimensions using a CNC machine. The density and volume fraction of the samples and the use of the rule of mixtures to calculate the mechanical properties of the laminates were calculated and entered into the ANSYS program. Then the boundary conditions were applied to the athlete's prosthetic foot and the total deformation, and the total strain energy was calculated to find out the best laminates in the athlete's foot industry. It was noticed that the laminates reinforced with carbon fibers were better than the laminates reinforced with glass fibers in terms of Young’s Modulus, as well as deformation. The best laminate obtained is (12 K + 4 C).
This work uses different shapes of intake manifold for study the effect on a single cylinder four stroke gasoline engine. A numerical simulation of the flow achieved through five intake manifold designs, using 3D Computational Fluid Dynamic (CFD) software package FLUINT (6.3.). Accordingly, the three-dimensional resolution of Navier-Stokes equations in conjunction with the standard k-ε turbulence model is undertaken to provide knowledge of the air movement nature and examining the intake manifold optimal geometry. Five cases of intake manifold are examined experimentally in order to produce a comprehensive and realistic data set. These data are in the form of engine performance, exhaust gas products and relative AFR for each case separately under different engine speeds. Exhaust gas analyzer type (Infragas-209) is used in the present work to measure exhaust gas concentrations and relative air/fuel ratio ( ). The results were obtained in this investigation showed that a Simulate numerically and experimentally is capable to select the optimized intake system geometry with reliability. Velocity is highest near the outer wall at increased the curvature ratio and pressure is highest near the inner wall at increased the curvature ratio. The secondary flow increases when the engine speeds and curvature ratio increase because of increasing the pressure difference between the inner wall and the outer wall. The effect of these parameters explained on the swirl air movement and tumble inside the cylinder are increasing by increase the engine speed and γ respectively. The increasing in the engine speed and the optimum selection of the manifold which designed enhanced the mixing of the fuel with air. The results showed that the optimized manifold 135º- NE (case 5) due to enhance AFR, fuel consumption and exhaust emissions are improved.
The study investigates the behaviour of reinforced concrete corner joints under monotonically increasing loads which tend to increase the right angle between the two joint members. The experimental results for two case studies are considered, and the ANSYS computer code is employed to create three-dimensional models for corner joints within the context of the finite element method. The effect of reinforcement details at the corner joint is studied for commonly used detailing systems, and the nonlinear response is traced throughout the entire load range up to failure. The results obtained are generally in good agreement with the experiments, and show that the detailing system has a significant effect on corner joint behaviour, with efficiencies ranging from as low as 54% up to 147%.
The present work investigates the effects of drinking water on the erosion- corrosion rate and Vickers hardness of (Al-Si) and (Al-Mg-Si). (Al-Si) alloy Which is well-known as casting alloy with high wear resistance, low thermal expansion coefficient, good corrosion resistance and improved hardness at a wide range of temperatures While (Al-Mg-Si) alloys have good formability, weld ability, machine ability and corrosion resistance. The alloys specimens which are used for piping and containing water and carbonated water were exposed in erosion- corrosion system in factories by using drinking water type AQUAFINA as exposure media for different exposure time (1-30)h. to measure the erosion-corrosion rate. The results show that there is small different in the rate of corrosion, moreover (Al-Mg-Si) alloy have high resistance to erosion-corrosion in drinking water due to the consisting of (Mg2Si) phase which is precipitate as fine particles due to resist dislocations movement lead to high corrosion strength and the (Al-Si) alloy have high Vickers hardness at natural aging due to the present of high ratio hardening silicon element.
Wastewater lagoons have proven to be an economically and environmentally beneficial alternative to traditional methods for treating sewage because of their unique properties, which include simplicity of use and inexpensive construction, energy, and maintenance costs. It is a natural wastewater treatment process that exploits the interactions between bacteria, algae, and other microorganisms and their surroundings to remove pathogens, organic matter, suspended particles, phosphates, ammonia, and nitrates. Stabilization lagoons are widely used throughout the world as they have proved to be a perfectly acceptable and satisfactory treatment system, the effluents produced in tertiary lagoons have been used for irrigation and aquaculture in many countries, indicating the high quality achieved during treatment in these units. This aim of this research is to overview the literature on lagoons' classification, design, and historical development. It also includes a set of relevant pilot and laboratory-scale experiments. As well as a comprehensive review of factors affecting lagoon performance, including sun's light, DO, pH, temperature, and nutrients. The relationship between these factors and their use in efficient contaminant removal is also discussed.
A large number of RC structures or at least some of their members need strengthening or rehabilitation. Among the typical failure modes, the shear failure is more dangerous and less predictable, because of usually brittle behavior and sudden collapse. Therefore, there are necessities for upgrading the shear capacity and the local ductility of reinforced concrete beams. In this study, four different techniques of concrete jacketing were used to improve the behaviors of the shear deficiencies beams. The four techniques used in this study to enhance the behavior of the beams were by using a Self-Compacted Fiber Reinforced Concrete jacket without stirrups (S.-J. + Steel Fiber), a concrete jacket of Self Compacted Concrete with stirrups (S.-J. + Stirrups), a concrete jacket of ferrocement jacket (S.-J. + Ferrocement), and a concrete jacket of ferrocement jacket with external steel reinforcing bars (S.-J. + Ferrocement + R). These techniques contributed to enhancing the load-carrying capacity and delaying the appearance of the first crack in tested beams compared with the control beam by a percentage of (35, 59, 30, 6) % and (18, 35, 81, 80) %, respectively. The specimen (S.-J. + Stirrups) showed the best performance in comparison with the other used strengthening techniques used in this study in terms of stiffness and the ultimate load-carrying capacity. The ferrocement jacket (S.-J. + Ferrocement) was found to be the most suitable jacketing system used to enhance the shear capacity in terms of cracking load.
Solar chimney (SC) together with earth to air heat exchanger (EAHE) is being employed as a low-energy consuming technique to remove undesirable interior heat from a building in the hot seasons. A numerical program "FLUENT 6.3 code" of an earth to air heat exchanger (EAHE) is studied for predicting the outlet air temperature and cooling potential of these devices in Basrah climate. Theoretical analyses have been conducted in order to investigate the ventilation in a solar chimney. The investigation into the viability of Low Energy Earth Pipe Cooling Technology in providing thermal comfort in Basrah. The demand for air-conditioning in buildings in Basrah affects the country escalating energy consumption. Therefore, this investigation was intended to seek for an alternative passive cooling to air-conditioning. The passive technology, where the ground was used as a heat sink to produce cooler air, has not been investigated systematically in hot and humid countries. A sub-soil temperature model adapted for the specific conditions in Basrah is presented and its output compared with CFD modeling. The results have shown that the potential of Earth Pipe is providing lower output temperature of air inlet to the room. We found that the resulting temperature at the buried pipe outlet decreases with increasing pipe length, decreasing pipe diameter, decreasing mass flow rate of flowing air in the pipe and increasing depths up to 4m.
The present work investigates the effects of drinking water on the erosion- corrosion rate and Vickers hardness of (Al-Si) and (Al-Mg-Si). (Al-Si) alloy Which is well-known as casting alloy with high wear resistance, low thermal expansion coefficient, good corrosion resistance and improved hardness at a wide range of temperatures While (Al-Mg-Si) alloys have good formability, weld ability, machine ability and corrosion resistance. The alloys specimens which are used for piping and containing water and carbonated water were exposed in erosion- corrosion system in factories by using drinking water type AQUAFINA as exposure media for different exposure time (1-30)h. to measure the erosion-corrosion rate. The results show that there is small different in the rate of corrosion, moreover (Al-Mg-Si) alloy have high resistance to erosion-corrosion in drinking water due to the consisting of (Mg2Si) phase which is precipitate as fine particles due to resist dislocations movement lead to high corrosion strength and the (Al-Si) alloy have high Vickers hardness at natural aging due to the present of high ratio hardening silicon element.
Supplying drinking water in Al-Dewanyia city to meet Iraqi Drinking Water Guidelines is a challenge as source waters contain high concentrations of Natural Organic Matter (NOM) that often exceed 12 mg/L Dissolved Organic Carbon (DOC). The US EPA indicates that enhanced coagulation is the best available technology to control DOC in drinking water treatment plants. A water director of Al-Qadissiya has used enhanced coagulation at Al-Dewanyia Water Treatment Plants (WTP’s) in Iraq since 2004 to improve water quality in the distribution system. NOM reduction has led to treated water with a lower chlorine demand allowing a greater residual penetration enabling improved bacteriological compliance. Since the cost of DOC (and Disinfection by-product DBPs) determination was high, it was decided to study the traditional analysis of COD as a surrogate measure to detect the organic constituents in raw water and the extent to which optimized coagulation with ferric chloride can increase COD removal. The water samples studied belonged to Al-Dewanyia River. For samples the observed values of COD removal by coagulation at lower pH (about 1-1.5 pH values less than the regular pH (5.8 ~ 8.5)) were about 85-95 percent without making water turbidity unacceptable. In order to determine the effects of organic content on coagulation, The results indicated that a modified coagulation process without need to much increasing the amount of coagulant can be developed for these water samples.
The solar chimney is a natural draft device that uses solar radiation to provide upward momentum to the in-flowing air, thereby converting the thermal energy into kinetic energy through an air turbine which in turn can be converted into electrical energy. The main parts of the solar chimney power plant are a large circular solar collector, a tall chimney, and an air turbine. In this paper, a theoretical study was performed to evaluate the performance of a solar chimney power plant system in Basrah City, where sunny days and solar radiation are high. A mathematical model was developed to study the effect of various parameters on the output power of the solar chimney. I1 was found that the output power depends strongly on the chimney tall and the difference between the collector air temperature and the ambient air temperature as well as the outside heat transfer coefficient, which essentially depends on the wind speed.
Gas flow measurements are pivotal in several medical applications. For instance, mechanical ventilators and respiratory monitoring applications need flowmeters with strict requirements. This study is concerned with a three-dimensional computational fluid dynamics (CFD) analysis. The CFD methodology was confirmed by analyzing the flow characteristics of flexible membrane with trapezoidal orifice plates. Variable area orifice meters (VAOMs) are increasingly being embraced in respiratory monitoring applications, employed in the context of mechanical ventilation within medical settings. Each system integrates a flexible orifice plate within the conduit. The simulations are conducted considering realistic deformations in structure through two-way fluid-structure interactions (FSI) using the Arbitrary-Lagrangian-Eulerian (ALE) approach. This research paper analyzes using the finite volume method (FVM). A thorough numerical simulation was performed for the turbulence models. The orifice's thickness and shape significantly influence pressure drop and deflection.
The heat lost from gas turbine power plants with exhaust gases represents the most important source for lowering its thermal efficiency. Also, the gas turbine thermal efficiency affected significantly with the ambient surrounding temperature. Al-Najybia gas-turbine power plant in Basrah, Iraq is choosing as a case study. The power plant consists of four units with a capacity of 125 MW for each unit. In the present study, all the calculations are performed for one unit only. Firstly the thermal impact is studied in terms of energy analysis for Al-Najybia gas turbine power plant (GTPP) for different ambient temperature for twelve months. Also, the economic loss a companied the heat lost with exhaust gases for different ambient temperature are estimated. Secondly, the thermo-economic improvement from coupling the GTPP with a heat recovery system is studied. For gas-steam combined cycle, the performance and economic analysis are performed. The results show that, the output power and thermal efficiency are decreased by 0.97 MW and 0.0726% respectively for each unit temperature rise of the ambient temperature. For the combined gas-steam power plant the percentage increasing of the thermal efficiency is approximately 46.4%. The results indicate the combined cycle power plant (CCPP) is very important to increase electrical capacity. From the economic analysis, the economic gain due to using HRB is 75757 $ per month.
The present work investigates the effects of drinking water on the erosion- corrosion rate and Vickers hardness of (Al-Si) and (Al-Mg-Si). (Al-Si) alloy Which is well-known as casting alloy with high wear resistance, low thermal expansion coefficient, good corrosion resistance and improved hardness at a wide range of temperatures While (Al-Mg-Si) alloys have good formability, weld ability, machine ability and corrosion resistance. The alloys specimens which are used for piping and containing water and carbonated water were exposed in erosion- corrosion system in factories by using drinking water type AQUAFINA as exposure media for different exposure time (1-30)h. to measure the erosion-corrosion rate. The results show that there is small different in the rate of corrosion, moreover (Al-Mg-Si) alloy have high resistance to erosion-corrosion in drinking water due to the consisting of (Mg2Si) phase which is precipitate as fine particles due to resist dislocations movement lead to high corrosion strength and the (Al-Si) alloy have high Vickers hardness at natural aging due to the present of high ratio hardening silicon element.