Scopus İndeksli Yayınlar Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12573/395
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Conference Object Citation - Scopus: 1Modeling and Simulation of Advanced Nuclear Reactors(IEEE Computer Society help@computer.org, 2013-11) Ablay, GünyazAdvanced nuclear power plants are currently being proposed with a number of various designs. However, there is a lack of modeling and control strategies to deal with load following operations. This research investigates a possible modeling approach for advanced nuclear power plants in order to provide an assessment way to the concept designs. The modeling approach covers linear and nonlinear reactor modeling and linear modeling of heat exchanger-turbine- generator systems. Numerical results are presented on an example molten-salt type nuclear power plant system to demonstrate the validity and effectiveness of the modeling approach. © 2013 IEEE. © 2014 Elsevier B.V., All rights reserved.Article Citation - WoS: 5Citation - Scopus: 6Ineffectiveness of Flood Cooling in Reducing Cutting Temperatures During Continuous Machining(Springer London Ltd, 2022-09-19) Kesriklioglu, SinanWater-based metalworking fluids are applied in the form of a liquid jet to flood the entire cutting zone and increase the tool life. The objective of this study is to investigate the effectiveness of flood cooling in reducing the tool chip interface temperatures during continuous cutting. An instrumented smart cutting tool with a thin film temperature sensor was fabricated to accurately measure the real-time cutting temperatures from 1.3 mu m below the tool chip interface in orthogonal turning of AISI 4140 steel under dry and flood cooling conditions. The cutting process was simulated in Deform 2D with the Johnson-Cook material model to present the transient temperature distributions on the coated cutting insert. The heat flux into the cutting tool was also estimated analytically and then three-dimensional finite element heat transfer simulations were performed to determine the maximum convective heat transfer of the cutting fluid in steady state. The measurements with the embedded thermocouple showed that flood cooling with a water-based cutting fluid slightly lowers the tool chip interface temperature. Moreover, the chip color may not be a good characteristic indicator to evaluate the cutting temperature in machining of metals. It was also found that flood cooling becomes more effective at a distance of approximately 150 mu m from the cutting edge where the chip does not contact the rake face of the cutting tool.Article Citation - WoS: 3Citation - Scopus: 5Feedback Controller Designs for an Electromagnetic Micromanipulator(Sage Publications Ltd, 2019-09-09) Boyuk, Mustafa; Eroglu, Yakup; Ablay, Gunyaz; Icoz, KutayMagnetic micromanipulators are capable of generating wide range of magnetic forces to manipulate magnetic microparticles for biomedical applications. In this study, a multipole magnetic micromanipulator system including electromagnets, driver circuitry and control unit is designed, modeled and implemented. The micromanipulator can produce a broad range of magnetic forces up to 25 pN on a single magnetic microparticle (1-10 mu m diameter) that is 5 mm away from the electromagnet core tip. Both linear and nonlinear controllers are designed and implemented, and the proposed nonlinear controller produces smooth control currents to assure closed-loop stability of the system with 1 s non-overshoot transient response and zero steady-state tracking error. The maximum output current of the driver circuitry is set to 1 A. The single particle at the center is moved at a speed of 5 mm/s. The fully automatic system can be utilized in applications related to single cell or microparticle manipulations.Article Citation - WoS: 5Citation - Scopus: 6Design, Modeling, and Control of a Horizontal Magnetic Micromanipulator(Sage Publications Ltd, 2019-01-31) Ablay, Gunyaz; Boyuk, Mustafa; Icoz, KutayMagnetic micromanipulators with a wide range of force generating capabilities are able to manipulate micron size particles for various applications and measurements. These magnetic particles can be coated with receptors to specifically bind to target biomolecules. In this work, a horizontal magnetic micromanipulator is designed, modeled and controlled for single micron size magnetic particle manipulations. A method is presented for dynamic modeling of magnetic micromanipulators. A feedback control method is designed that allows direct linearization of the system. It is shown that the proposed controller guarantees the stability of the closed-loop system, and yields zero steady-state error in a wide range of operation conditions. We show that the micromanipulator is able to generate a wide range of piconewton (pN) scale forces on a superparamagnetic particle for single molecule separation, and biosensor developments.Article Comprehensive Optimization of Shot Peening Intensity Using a Hybrid Model With AI-Based Techniques via Almen Tests(Walter de Gruyter Gmbh, 2025-06-03) Karaveli, Kadir Kaan; Bal, BurakShot peening is a crucial surface treatment technique that significantly improves the mechanical properties of metallic components, particularly their fatigue resistance and ability to withstand corrosion cracking. This study aims to optimize the shot peening process for aviation applications by evaluating and comparing various mathematical modeling and optimization techniques. Seven mathematical models were analyzed using a neuro-regression method (NRM), among which the second-order trigonometric non-linear (SOTN) model exhibited the highest reliability, achieving R2 values of 0.93 and 0.90 for training and testing datasets, respectively. To improve the model's robustness, four optimization algorithms - differential evolution (DE), simulated annealing (SA), Nelder-Mead (NM), and random search (RS) - were applied to the SOTN model. Although each technique offered valuable insights, performance fluctuations across different intensity ranges necessitated the development of a hybrid optimization model that combines the strengths of all four methods. The hybrid model achieved a mean error of approximately 2.69 %, outperforming individual approaches and demonstrating strong potential for reliable shot peening optimization across a wide range of target intensities. These findings provide a comprehensive methodology for AI-based optimization of surface treatment processes in engineering applications.Article Citation - WoS: 10Citation - Scopus: 13A Study of Different Microstructural Effects on the Strain Hardening Behavior of Hadfield Steel(Korean Soc Steel Construction-KSSC, 2018-03) Bal, BurakThe effects of the initial texture, velocity gradient, strain increment and type of interaction tensor on the strain hardening response of Hadfield steel were investigated. To observe their influences on mechanical response, crystal plasticity computations were carried out with the aid of the Visco-Plastic Self-Consistent (VPSC) algorithm. Specifically, uniaxial deformation response of Hadfield steel was modeled based on the experimental deformation response at a strain rate of 1x10(-1) s(-1) and corresponding Voce hardening parameters were calculated. The same Voce hardening parameters were utilized with different boundary conditions in the VPSC simulations to identify the roles of the aforementioned microstructural properties. The current results demonstrate the importance of these microstructural properties for reliable predictions of the strain hardening response of Hadfield steel and constitute an important guideline for the proper selection of them.Article Citation - WoS: 41Citation - Scopus: 47A Modeling and Control Approach to Advanced Nuclear Power Plants With Gas Turbines(Pergamon-Elsevier Science Ltd, 2013-12) Ablay, GunyazAdvanced nuclear power plants are currently being proposed with a number of various designs. However, there is a lack of modeling and control strategies to deal with load following operations. This research investigates a possible modeling approach and Load following control strategy for gas turbine nuclear power plants in order to provide an assessment way to the concept designs. A load frequency control strategy and average temperature control mechanism are studied to get load following nuclear power plants. The suitability of the control strategies and concept designs are assessed through linear stability analysis methods. Numerical results are presented on an advanced molten salt reactor concept as an example nuclear power plant system to demonstrate the validity and effectiveness of the proposed modeling and load following control strategies. (C) 2013 Elsevier Ltd. All rights reserved.Conference Object A Horizontal Magnetic Tweezer for Single Molecule Micromanipulations(Institute of Electrical and Electronics Engineers Inc., 2018-10) Ablay, Günyaz; Böyük, Mustafa; Eroǧlu, Yakup; İçöz, KutayMagnetic tweezers are able to manipulate cells or biomolecules for various applications and measurements. In this work, a horizontal magnetic tweezer is designed, modeled and controlled for single molecule manipulations. A method is presented for dynamic modeling of horizontal magnetic tweezers. A linear control method is designed to ensure a wide range of operation conditions with zero steady-state error. The horizontal magnetic tweezer is able to generate a wide range of piconewton scale forces on a superparamagnetic microparticle for single molecule separation, and biosensor developments. © 2019 Elsevier B.V., All rights reserved.