GHz Range Magnetoelectric Coupling of MnFe₂O₄ and Mn Doped BiFeO₃ Heterostructures

Fikret Yildiz,Chan Ho Yang,Sinan Kazan,Bekir Aktas,Yoon He Jeong 한국자기학회 2010 한국자기학회 학술연구발표회 논문개요집 Vol.2010 No.12

Enhancing the Accuracy for the Open-loop Resolver to Digital Converters

Fikret Anıl Karabeyli,Ali Ziya Alkar 대한전기학회 2018 Journal of Electrical Engineering & Technology Vol.13 No.1

In this study, improvements for error correction, speed, position, and rotation calculation algorithms have been proposed to be used in resolver to digital conversion (RDC) systems. The proposed open-loop system drives the resolver and uses the output signals of the resolver signal to estimate the real time position, the instant speed, and the rotation count with high resolution and accuracy even at high speeds and noise. The proposed solution implements strong features of both closed and open loop based systems while eliminating their weak points. The improvements proposed is resistant to noise owing to digital FIR filter and data averaging techniques. The implementation used for proof of concept is implemented on a hardware using an FPGA and configurable to be used by any resolver.

Investigating the Efficiency of Secondary Aging and Burnishing Process in Friction Stir Welded Al-7075-T6 Material

Fikret Sönmez,Hüdayim Başak,Ahmet Güral,Şehmus Baday 한국정밀공학회 2018 International Journal of Precision Engineering and Vol.19 No.10

In this study, firstly all of Al-7075-T6 alloys were joined by the friction stir welding (FSW) method then the samples were divided into four groups. First group of samples were used directly. The second group of samples was burnished. Third group of samples were aged and the last group of samples was subjected to both re-aging and burnishing process. It was compared the tensile and bending strengths of all prepared specimens. After the FSW process, only the second aging process increased the tensile strength. There is no effect on the tensile strength of the burnishing process. The bending strength has improved only the re-aging process without burnishing operation or only burnishing without the second aging process. In the friction stir welded Al-7075-T6 materials, it was concluded not to have a significant effect on the mechanical properties of the burnishing process. However, the hardness values of the materials were increased by both the re-aging and the burnishing process.

Unusual Presentation of a Penetrating Aortic Arch Injury

Fikret Sami Vural,Atul Kumar Patel,Kashif Mustafa 대한흉부외과학회 2017 Journal of Chest Surgery (J Chest Surg) Vol.50 No.4

A 27-year-old man was admitted with a penetrating injury at the mid-manubrium. Computed tomographic (CT) angiography s howed a f illing def ect in t he a ortic arch. This was e valuated a s a sign o f injury and the patient underwent an e mergency o peration. No a ctive bleeding o r clot w as f ound in t he m ediastinum d uring the operation. The laceration point was between the innominate and the left carotid artery posteriorly. The injury was approached using hypothermic circulatory arrest. Aortotomy and exploration showed a 2-cm-long full-thickness aortic injury with an overlying clot. A filling defect on angiography as a sign of a penetrating arch injury has never been reported previously, but was the main pathological finding on CT angiography in our case. The aorta is a high-pressure system and injuries to it should be treated aggressively.

METHODOLOGICAL VARIATIONS IN TEXTBOOKS OF TURKISH GRAMMAR AND SYNTAX USED IN TURKISH UNIVERSITIES

TURAN, FIKRET Academia Via Serica 2018 Acta Via Serica Vol.3 No.1

Textbooks of Turkish grammar and syntax that are commonly used in Turkish universities demonstrate certain differences of approach, interpretation and terminology of syntax. In this article, I analyze the syntactic approaches that are implemented in the grammar works of Muharrem Ergin, Tahsin $Banguo{\breve{g}}lu$ and Tahir Nejat Gencan, and in the syntax works of Leyla Karahan, Mustafa ${\ddot{O}}zkan$ & Veysi Sevinçli and H. ${\dot{I}}brahim$ Delice as the most commonly used textbooks, and determine resemblances and variations of syntactic approaches between them. It is concluded that, among others, the most prominent differences between these works concern the constructions of the non-finite subordination, the ki-subordination and compound sentences.

Enhancing the Accuracy for the Open-loop Resolver to Digital Converters

Karabeyli, Fikret Anil,Alkar, Ali Ziya The Korean Institute of Electrical Engineers 2018 Journal of Electrical Engineering & Technology Vol.13 No.1

In this study, improvements for error correction, speed, position, and rotation calculation algorithms have been proposed to be used in resolver to digital conversion (RDC) systems. The proposed open-loop system drives the resolver and uses the output signals of the resolver signal to estimate the real time position, the instant speed, and the rotation count with high resolution and accuracy even at high speeds and noise. The proposed solution implements strong features of both closed and open loop based systems while eliminating their weak points. The improvements proposed is resistant to noise owing to digital FIR filter and data averaging techniques. The implementation used for proof of concept is implemented on a hardware using an FPGA and configurable to be used by any resolver.

Synthetic Fiber Dyeing with New Pyrazole Disperse Dyes and Their Colorimetric and Fastness Properties

Emine Bakan,Fikret Karcı,Ozan Avinc 한국섬유공학회 2018 Fibers and polymers Vol.19 No.3

A series of disazo pyrazole disperse dyes were synthesized and reported at our previous work. These 8 synthesized disazo pyrazole disperse dyes (3a-3h) were applied to poly(lactic acid) (PLA), poly(ethylene terephthalate) (PET), and polyamide 6.6 fibers. Their colorimetric and color fastness properties were investigated. All studied fibers dyed with these synthesized dyes exhibited yellow-red shades. 3c (p-Cl), 3e (m-Cl), and 3h (o-Cl) disazo disperse dyes, having auxochrome -Cl, led to the lowest color yield values for all three studied fibers. The same dyes resulted in higher color strength with darker shades on the PET and PLA fabrics in comparison PA 6.6 fabrics. 3a (p-NO2), 3b (p-OCH3), 3d (m-NO2), 3f (o-NO2), and 3g (o-OCH3) disazo disperse dyes can be recommended for PLA and PET dyeing from the color point of view leading to medium to heavy depth of shades. The wash, alkaline and acidic perspiration, dry and wet rub, water and sea water fastness levels of PLA, PET, and PA 6.6 samples dyed with 3a-3h dyes were generally quite high and in the commercially acceptable range with few exceptions. Dyed PLA fabrics displayed better sublimation fastness levels than dyed PET and PA 6.6 fabrics. Synthesized disperse dyes resulted in high light fastness performance on especially PET and PLA fibers. Light fastness level was better for dyed PET samples by comparison with dyed PLA and PA 6.6 fabrics.

Lessons learned from 12,000 robotic radical prostatectomies: Is the journey as important as the outcome?

강성구,심지성,Fikret Onol,K. R. Seetharam Bhat,Vipul R. Patel 대한비뇨의학회 2020 Investigative and Clinical Urology Vol.61 No.1

Robotic radical prostatectomy (RARP) is a standardized treatment for localized prostate cancer, which provides better functional outcomes and similar oncological outcomes compared to open approaches. Here, we share our experience of 12,000 RARPs by describing the outcomes of the procedure in terms of positive surgical margin (PSM), continence, and potency as well as by presenting our detailed surgical technique with recent modifications. On cancer control, the PSM rates were 5.8% and 26.1% in T2 and T3, respectively. On the premise of not compromising oncologic outcomes, a tailored approach to individual patients is essential. Even if an extracapsular extension is suspected, neurovascular bundle (NVB) tailoring can be applied using an anatomical landmark to preserve maximal nerve tissue with a negative margin. We developed a nomogram as a useful tool for deciding the degree of tailoring. For improvements of functional outcomes, we used athermal retrograde early release with a toggling technique, wherein the nerve dissection from the bottom helps with blood loss and allows for smooth NVB releasing. Additionally, we recently performed a new minimal apical dissection/lateral prostatic fascia preservation technique. As a result, our 1-week continence rate was 37% and the 6-week rate was 77.6%. In addition, the potency rates in our study were 69%, 82%, and 92% at 3 months, 6 months, and 1 year, respectively (preoperative Sexual Health Inventory for Men scores >21 & bilateral full nerve spared).

Rehabilitation of heavily earthquake damaged masonry building using steel straps

Sinan Altin,Fikret Kuran,Özgür Anil,M. Emin Kara 국제구조공학회 2008 Structural Engineering and Mechanics, An Int'l Jou Vol.30 No.6

The purpose of this study is to develop a rehabilitation technique for heavily earthquake damaged masonry buildings. A full scale one storey masonry building with window and door openings was manufactured and tested on the shock table by applying increased amplitude free vibration up to the point where heavy earthquake damage was observed. Damaged test building was rehabilitated with vertical and diagonal steel straps and then tested again. The effectiveness of improvements obtained by the rehabilitation technique was investigated. Steel straps improved the lateral strength and stiffness of masonry walls and limited the lateral displacement of building. Stability of the masonry walls were also improved by the steel straps. Steel straps reduced the natural period of the earthquake damaged masonry building and prevented the failure of the building at the same amplitude of free vibration.

Modeling and optimization of the spray drying parameters for soapwort (Gypsophila Sp.) extract

Onur Özdikicierler,Nur Dirim,Fikret Pazır 한국식품과학회 2019 Food Science and Biotechnology Vol.28 No.5

In this study, the effects of spray drying parameters as feed soluble solid content, inlet air temperature and outlet air temperature on spray drying of soapwort (Gypsophila arrostii) extract have been examined. Central composite design was used with 15–30 °Bx, 110–160 °C and 50–80 °C for feed soluble solid content, inlet air temperature and outlet air temperature, respectively. Moisture content, water activity, tapped density, total saponin content and foam volume of the obtained powders were measured as responses of the experimental plan. The spray drying parameters were optimized by considering saponin content and foam volume by response surface methodology. According to the numerical optimization, optimum feed soluble solid content, inlet and outlet air temperatures were 15 °Bx, 160 °C and 67 °C respectively with a desirability factor of 0.822. After verification at optimum conditions, the error percentages were found to be 5.96% and 2.15% for saponin content and foam volume respectively.