Satılmış Ürgün

• PhD
• Professor (Associate) at Kocaeli University

This paper presents a ZVT-ZCT active snubber cell for high frequency operation of dc/dc boost converter. Active snubber cell ensures zero crossings at any time required for soft switching (SS) and provides zero voltage transition (ZVT) turn-on and zero current transition (ZCT) turn-off together for the main switch of boost converter. The proposed c...

The drilling machinability of glass fiber G14, basalt fiber B14, and two hybrid laminates (B4G6B4, G4B6G4) was evaluated through 36 full-factorial experiments employing an HSS-G drill, three spindle speeds (715, 1520, 3030 rpm), and three feed rates (0.1–0.3 mm rev−1). Peak thrust force varied from 65.8 N for B14 at 0.1 mm rev−1 to 174.3 N for G14...

This study focuses on cold deformation and age effects on the microhardness and electric conductivity of the Cu-4Ti (wt.%) alloys. The samples were solution treated at 900 °C, quenched in water, and aged at 450–600 °C for 1–120 min. Fifty percent cold rolling was performed before aging to analyze the impact on their microstructure and properties. H...

This is a research study on the high-temperature solid particle erosion behavior of basalt/carbon hybrid composites with varying ply arrangements (B8, C8, B4C4, C4B4, B2C4B2, and C2B4C2). Solid particle erosion experiments were carried out by employing garnet particles at temperatures of 25 °C, 50 °C, 80 °C, and 120 °C at impingement angles of 30°...

The present study explores the effects of pre-coating on the wear performance of milled carbon fiber-filled basalt composites via laser texturing. Laser texturing was used to change surface topography, enhancing adhesion and wear resistance. Incorporated 0 wt.% and 5 wt.% milled carbon fibers in an epoxy matrix. A fiber laser system was employed fo...

This work investigates the hybrid fiber sequence effect on the flexural and impact properties of basalt/carbon epoxy composites. In the present study, six configurations of composite laminates were fabricated by vacuum-assisted resin transfer method and tested in three-point bending and Charpy impact tests. The results show that hybrid composites o...

The optimization of CuNi2Si1 alloy’s mechanical and electrical properties was achieved through a combination of experimental approaches and metaheuristic algorithms. Optimizing hardness and electrical conductivity through a variation in aging temperature (450–600 °C) and aging duration (1–420 min) was taken under consideration in the present work....

The following study aimed to optimize CO2 laser processing parameters for 1.2379 cold work tool steel to improve its surface properties. As its applications required high durability, strength, and precision, surface roughness and microhardness values were adjusted by varying laser power from 70% to 92%, laser speed from 1 to 5 mm/s, and stand-off d...

This paper aims to predict and optimize the behavior of solid particle erosion in polymethyl methacrylate material through artificial neural networks assisted with the implementation of metaheuristic algorithms. For the study, artificial neural networks (ANNs) and the corresponding metaheuristic algorithms, such as genetic algorithm (GA), particle...

In this study, the surfaces of sheets made of AA1050 aluminum alloy, which has high aluminum purity and also high strength, were roughened with a fiber laser. The aim of the study is to obtain a surface with a highly stable contact angle. For this purpose, it was aimed to minimize the change in the contact angle with time. Three different laser pro...

This work investigates the effects of laser processing parameters on basalt fiber‐reinforced composites for the optimization of surface processing without fiber damage. Various conditions of laser power, speed, and stand‐off distance were applied using a CO₂ laser. Consequently, a well‐processed morphology with full matrix removal and clear fiber e...

This work investigates the addition of milled carbon fiber reinforcement and its effect on scratch resistance and mechanical durability for basalt fiber/epoxy composites, assessed under varied loading conditions with the aid of different indenter types according to a factorial design. Composites with MCF content from 0 to 10 wt% were prepared. Scra...

The solid particle erosive wear performance of basalt fiber‐reinforced epoxy composites with the incorporation of different percentages of milled carbon fiber fillers (0–10 wt%) is evaluated under various abrasive materials (garnet and ceramic beads) and impingement angles (30° and 90°). Erosion tests have been carried out following ASTM G76 standa...

35NCD16 steel is frequently used in landing gear, engine components, and various fasteners due to its high strength and durability properties. This study was carried out to identify the effects of laser-induced burns on 35NCD16 low-alloy steel, which is widely used in the aerospace industry. The aim was to measure the effects on the magnetic behavi...

4330 steel is frequently used in landing gear, shafts, gears, engine components, aircraft frames and structural components, fasteners, hydraulic systems due to its high strength, good fatigue resistance, hardness, toughness, durability properties. This study examines 4330 steel, a durable material in the aerospace industry, that has undergone surfa...

This paper has presented the results of a study aiming to identify the effects of laser power and two other parameters on groove formation in ST52 steel using a fiber laser and to optimize these parameters so that the groove aspect ratio could be maximized. The Taguchi method has been used to explore the effects of three parameters, namely, laser p...

This research explores the scratch resistance of polymer composites reinforced with hybrid glass and basalt fibers under repeated loadings. By examining the behavior across 1–10 repetitions using Rockwell and Vickers indenters, the study delves into the complex interplay between composite matrices and the fibers' configurations. Through Scanning El...

This study looks at how erosive wear affects hybrid composites made by vacuum infusing glass and basalt fibers into an epoxy matrix. The study uses garnet abrasives and a design experiment method to test how resistant these hybrid composites are to erosion at 30°, 60°, and 90° angles of impact. The analysis included three‐dimensional profilometry a...

Manufacturing microscale textures can reduce friction and wear compared with smooth surfaces. In laser surface texturing, the resulting texture geometry is directly affected by laser parameters such as laser power, scanning speed and overlap rate. Therefore, finding the optimal parameter settings to improve the process performance is crucial. One o...

This study fixates on determining the optimum laser input parameters that simultaneously meet the desired kerf width and depth during CO2 laser cutting of various polymethylmethacrylate (PMMA) sheets. It has three contributions. The first is to model the cutting process of PMMA by polynomial curve fitting as a function of laser power, laser speed,...

Al2O3 ceramic materials have many industrial applications, especially because they have wear resistant. In this study, dimples of different sizes were formed on the surface of ceramic plates with a CO2 laser. The effects of laser power and laser exposure time on the dimensions of the cavity were investigated. For this purpose, laser powers of 40, 5...

The texture of the surfaces of materials causes changes in mechanical properties such as friction. Micro-scale cavities have been created on Hardox steel plate, which has recently been the focus of attention in demanding applications with its hardness, toughness and wear resistance. CO2 laser was used in the cavitation process on the surface and th...

Dimples on Al2O3 ceramic plates were created with a CO2 laser using different laser parameters. The effects of the laser parameters used on the dimple geometry were investigated and the necessary laser parameters were optimized to obtain the desired dimple geometry. Taguchi method was used in the optimization process. The effects of laser power, sc...

The surface texture process was done with carbon dioxide laser on dual-phase steel (DP 1180). The effects of the parameters of the carbon dioxide laser on the contact angle, skewness and kurtosis values were investigated, and the laser parameters required for obtaining the highest contact angle, lowest skewness and highest kurtosis have been optimi...

Multilevel inverters (MLI) are popular in high-power applications. MLIs are generally configured to have switches reduced by switching techniques that eliminate low-order harmonics. The selective harmonic elimination (SHE) method, which significantly reduces the number of switching, determines the optimal switching moments to obtain the desired out...

Multilevel inverters (MLIs) are one of the most popular topics of power electronics. Selective harmonic elimination (SHE) method is used to eliminate low-order harmonics in the MLI output voltage by determining the optimum switching angles. It includes the solution of nonlinear sets of transcendental equations. The optimization becomes more difficu...

The effect of surface texture on the tribological properties of materials is one of the most popular topics. Because of their disadvantages, numerous studies were done to upgrade the erosive wear resistance of polymeric materials. To understand the surface textures and their orientations effect on particle erosion behavior of polymeric materials, t...

An aerodynamic technique for calculating lift and drag coefficients is one of the required instruments in the wing design process. In recent decades, several tools and software have been developed based on aerodynamics and numerical methods. Today, aircraft architecture needs a great deal of calculation. To prevent expensive model testing, modern t...

Vehicles that operate at altitudes close to the sea surface by taking advantage of the ground effect enable us to overcome the hydrodynamic force exerted by the water on the vehicle, allowing us to reach general aviation speeds, while also making it possible to carry more cargo than an aircraft by taking advantage of the ground effect. In this arti...

Yüksek doğrulukta işlemleri yapması beklenen uçuş simülatörleri için düşük maliyetli hareket sistemleri kullanılmaktadır. Bu sistemler daha kısa manipülatör, küçük hareket kapasitesi ve yüksek çalışma gürültüsü barındırmaktadır. Bu tarz etkilerin uçuş eğitimi alan pilotun algıları üzerindeki etkileri bilinmemektedir ve araştırılmaları gerekmektedir...

Airfoil(kanat), daha düşük sürükleme ile yeterli miktarda taşıma üreterek uçağı havada tutan ve herhangi bir hava aracında önemli bir rol oynayan aerodinamik gövdedir. Kanat yapısının gelişimi boyunca kanatta maksimum taşıma üretebilmek için kanadın alt yüzeyindeki yüksek basınç ve üst yüzeyindeki düşük basınç kavramları ile ilgilenilmiştir. Ve bu...

Günümüzde 3 boyutlu (3D) yazıcılarla parça üretimi giderek artan oranda kullanılan bir yöntem haline gelmektedir. 3D yazıcılarla üretilen parçalarda hammadde olarak polilaktik asit (PLA) filamantler kullanılmaktadır. PLA malzemeden üretilmiş parçaların servis şartları altında yüzey çizilmelerine dayanımı düşük olabilmektedir. 3D yazıcılarla üretilm...

dditive Manufacturing (AM), which more commonly known as 3D printing, is an extremely popular, fast and flexible manufacturing method. Rectangular prismatic textures are created on a surface via 3D printing technique. It is observed that the surface texture obtained by AM reduces particle erosion by half under the same erosion direction, and the an...

Halk tarafından genelde kara kutu olarak bilinen FDR(Flight Data Recorder) ve CVR(Cockpit Voice Recorder) kayıt cihazları havacılık için çok önemlidir. Havacılıkta FDR ve CVR cihazlarına takılı olarak kullanılan ULB(Underwater Locator Beacon) ise su ile temas ettiğinde belirli bir frekansta akustik sinyal yayan bir sualtı ses vericisidir. Enkazın s...

In aviation, which is in a major competition, the most important factors after flight safety, have always been the catering and in-flight entertainment system (IFE). Many of the in-flight entertainment systems (IFEs) have been on the market with various designs, but they have not been successful due to authority, design and for other reasons. Numbe...

Seri ve paralel mekanizmalar günümüzde birçok alanda yoğun şekilde kullanılmaktadır. Paralel mekanizmaların en yaygın kullanıldığı Stewart Platformu, ilk olarak 1965’te D. Stewart tarafından uçak simülatörlerinde kullanılmak üzere yapılmıştır. Stewart platformu, biri hareketli diğeri sabit olmak üzere iki plaka arasına yerleştirilen ve uzunluğu değ...

In this study, a new zero-voltage transition (ZVT)-zero-current transition (ZCT) quasi-resonant buck converter, which ensures zero crossings at any time required for soft switching (SS) and provides ZVT turn-on and ZCT turn-off together for the main switch of active snubber cell in buck converter is presented. The proposed circuit combines the most...

Published quadratic equations obtained by response surface methodology (RSM) for high hydrostatic pressure (HHP) inactivation of Bacillus cereus spores, Bacillus subtilis spores and cells, Staphylococcus aureus and Listeria monocytogenes, all in milk buffer, were used to demonstrate the utility of genetic algorithms (GAs). It was possible to obtain...

Recently, DC-DC boost converters are usually required in many applications which has low output voltage, such as renewable energy sources. The interleaved boost converters consists of several identical boost converters connected in parallel and controlled by the interleaved method which has the same switching frequency and phase shift. The advantag...

In switch mode power supplies (SMPS), flyback converters are very popular because of, design simplicity, low cost, multiple isolated outputs, high output voltages and high efficiency. They are preferred especially for low power applications (150W). In this work, flyback converters are analyzed, mathematical modeled, designed with given parameters,...

In this article, the new ZVT–ZCT Quasi-Resonant DC Link, which ensures zero crossings at any time required for soft switching (SS) and provides zero voltage transition (ZVT) turn-on and zero current transition (ZCT) turn-off together for the main switch of active snubber cell in pulse width modulated or space vector modulated operation of inverter...

In this paper, a universal auxiliary circuit named Zero Current and Zero Voltage Transition (ZCZVT) commutation cell applied to buck converter is presented. The operation of the proposed ZCZVT commutation cell applied to buck converter is theoretically analyzed. With the use of the proposed commutation cell, which is activated only during the switc...

Kurulumunun basitliği, maliyetinin diüşük olması, girişen ve birbirinden elektriksel olarak yalıtılmış birden fazla çıkış verebilmesi yüksek verimleri nedeniyle Flyback dönüştürücüler anahtarlamlı güç kaynakları içinde oldukça yaygın olarak kullanılmaktadır. Özellikle düşük güçlü (150W) uygulamalar için tercih edilir. Bu uygulamada, Flyback dönüştü...

In this paper, a novel DC link softswitched inverter is presented. The new inverter uses softswitched frequency unfolder technique to provide soft-switching feature while keeping pulse width modulation (PWM) capability without high voltage stress The main obstacle for inverters to operate at high frequencies is the increasing switching losses with...

Sinusoidal and space vector pulse width modulation (SPWM-SVPWM) techniques have been extensively used to build inverters, which generate AC voltage from DC voltage. The main application of this type of inverters is for variable speed induction motor drives. With the popularity of microprocessors, the implementations of these techniques are being us...

In this paper, a method for voltage harmonic elimination in a pulse width modulated (PWM), single phase inverter using genetic algorithms (GAs) is proposed. We explain the resolution method procedure of the non-linear equation systems in order to achieve the appropriate switching angles. The output voltages with k pulses per half cycle are written...

Single-phase inverters are specially used in the power supplies of computer units which placed in Telecom centrals. Being the voltage produced in an inverter is harmonically composed, causes a problem. In this study, in order to make the voltage on the load constant hysteresis current control was made by using the ability of learning and guessing t...

A new software implementation of the space vector modulation (SVM) on the vector controlled induction machine is proposed. The conventional SVM requires square root and arctangent computations. New SVM algorithm is develop to determine directly conducting times without square root and arctangent computations.

Günümüzde eviricilerin kullanõm alanõ gittikçe artmaktadõr. Bu nedenle istenen ihtiyaçlara cevap verebilecek yüksek performans, düşük maliyet oranõ iyi eviricilerin tasarlanmasõ gerekmektedir. Bu makalede geliştirilen, yukarõdaki özelliklere sahip mikrodenetleyici sistemi ile üç fazlõ eviricilerin kolaylõkla denetiminin yapõlabildiği gösterilmekted...

Günümüzde eviricilerin kullanõm alanõ gittikçe artmaktadõr. Bu nedenle istenen ihtiyaçlara cevap verebilecek yüksek performans, düşük maliyet oranõ iyi eviricilerin tasarlanmasõ gerekmektedir. Bu makalede geliştirilen, yukarõdaki özelliklere sahip mikrodenetleyici sistemi ile bir fazlõ eviricilerin kolaylõkla denetiminin yapõlabildiği gösterilmekte...

zet DA-DA yükseltici(boost) dönüştürücüler endüstri uygulamalarında geniş olarak yer almaktadır. Da-Da dönüştürücüler üzerine yapılan araştırmaların çoğu, en iyi anahtarlama yönteminin ortaya konması üzerine yoğunlaşmıştır. Son 10 yıl boyunca güç elektroniğinde sayısal kontrol yoğun bir şekilde kullanılmıştır. Performanslarındaki yükselme ve maliye...

fazlı Darbe Genişlik Ayarı (DGA) eviriciler yüksek güçlü ve verimli endüstriyel uygulamalarda yaygın bir şekilde kullanılmaktadır. Günümüzde anahtarlama teknolojileri geliştirilerek, basit mikrodenetleyicilerle elde edilebilen ve verimi DGA yönteminden daha üstün olan Uzay Vektör Ayarı (UVA) yöntemi geliştirilmiştir. Bu makalede üç fazlı IGBT eviri...

ZET Son yıllarda hız denetimli sürücülerin (HDS) kullanılmasında önemli bir artış olmuştur. HDS'lerin endüstriyel, otomotiv ve tüketim marketleri gibi alanlarda kullanımı hızla artmaktadır. HDS'lerin üstünlükleri sistemin verimini arttırması ve fiyatını düşürmesidir. Uzay vektör ayarı yada UVA (space vector modulation) , HDS'lerin verimini arttıran...