Yazar "Gurses, Baris Oguz" seçeneğine göre listele
Listeleniyor 1 - 12 / 12
Sayfa Başına Sonuç
Sıralama seçenekleri
Öğe Analysis of Rolling Element Bearing Faults Via Curve Length Transform(Springer Heidelberg, 2014) Kiral, Zeki; Yigit, Ahmet; Gurses, Baris OguzThis paper aims to present the performance of a simple nonlinear time domain transformation known as Curve Length Transform (CLT) on the detection of rolling element bearing faults. Experimental vibration velocity and acceleration responses collected from a test rig are used to analyze the bearing signals. Artificial defects are introduced on the raceways of inner and outer rings of a deep groove ball bearing to examine different bearing faults. Unbalance load condition is created by attaching an eccentric mass to the rotating shaft in order to analyze the effect of the unbalance load together with the bearing fault on the performance of the curve length transform. Basic temporal indicators such as Root Mean Square (RMS), standard deviation, peak to peak, crest factor and kurtosis derived from the curve length signals are used for defect detection purpose. Time domain analyses based on the experimental measurements show that the curve length transform can be used to enhance the diagnostic capabilities of some time domain indicators.Öğe Characterization and analysis of motion mechanism of electroactive chitosan-based actuator(Elsevier Sci Ltd, 2018) Altinkaya, Emine; Seki, Yoldas; Cetin, Levent; Gurses, Baris Oguz; Ozdemir, Okan; Sever, Kutlay; Sarikanat, MehmetIn order to analyze the bending mechanism of the electroactive chitosan- based actuator, different amounts of poly(diallyldimethylammonium chloride) (PDAD) were incorporated in chitosan solution. The effects of PDAD concentration on electromechanical performance of chitosan actuator were investigated under various excitation voltages. With the incorporation of PDAD into chitosan solution, crosslinked chitosan film acts as an actuator showing a considerable displacement behavior. However it can be noted that higher incorporation of PDAD into chitosan solution decreased the performance of the actuators. Thermal, viscoelastic, and crystallographic properties of the chitosan films were examined by thermogravimetric analysis, dynamic mechanical analysis, and X- ray diffraction analysis, respectively. The effect of incorporation of PDAD in chitosan- based film on morphological properties of chitosan film was determined by scanning electron microscopy. It was observed that the films involving PDAD have larger pore size than the PDAD free film.Öğe Deep learning for automated detection and numbering of permanent teeth on panoramic images(British Inst Radiology, 2022) Gurses, Baris Oguz; Sener, Elif; Guneri, Pelin[No Abstract Available]Öğe The effect of gold electrode thicknesses on electromechanical performance of Nafion-based Ionic Polymer Metal Composite actuators(Elsevier Sci Ltd, 2019) Yilmaz, Ozgun Cem; Sen, Ibrahim; Gurses, Baris Oguz; Ozdemir, Okan; Cetin, Levent; Sarikanat, Mehmet; Seki, Yoldas; Sever, Kutlay; Altinkaya, EmineThe effect of gold electrode thickness (10, 27, 45, 67 and 80 nm) on the electromechanical performance of Nafion-based Ionic Polymer Metal Composite (IPMC) actuators was investigated in this study. The mechanical, morphological, electrical properties and electroactive behaviors of IPMC under direct current voltage (DC) and alternating voltage (AC) were examined. The tip displacement and maximum blocking force of actuators under various electrical stimulations were measured. In order to define transient response characteristics and quasi steady state value of the actuators, DC excitations of 1, 3, 5, 7 and 9 V were used. Besides, to define bandwidth of the actuator samples, square wave excitation with magnitudes of 3, 5, and 7 V and frequencies of 0.1, 0.25, 0.5, 1, and 2 Hz were applied to actuator samples. The actuator having a gold electrode thickness of 45 nm produced maximum tip displacement among all actuators for all excitation DC voltages. In the square wave experiments, the higher cutoff frequencies were observed for the actuators with 27 and 45 nm electrode thicknesses. The blocking force of IPMC increased with increasing gold electrode thickness from 10 nm to 45 nm and decreased with increasing gold electrode thickness from 45 nm to 80 nm.Öğe Effects of PEG loading on electromechanical behavior of cellulose-based electroactive composite(Springer, 2015) Ozdemir, Okan; Karakuzu, Ramazan; Sarikanat, Mehmet; Akar, Emine; Seki, Yoldas; Cetin, Levent; Sen, Ibrahim; Gurses, Baris Oguz; Yilmaz, Ozgun Cem; Sever, Kutlay; Mermer, OmerElectroactive behavior of carboxymethylcellulose (CMC)-based actuators was investigated in this study. CMC-based films were firstly fabricated by using 1-butyl-3-methylimidazolium bromide. Characterization studies of the CMC films were conducted by using Fourier transform infrared, X-ray diffraction analysis, thermogravimetric analysis, scanning electron microscopy, and tensile testing. CMC-based actuator films were produced by gold coating on both surfaces of CMC-based films Polyethylene glycol (PEG) at different loadings (1, 1.5 and 2 g) was used to improve electroactive behavior of CMC based actuators. Maximum tip displacements were obtained under DC excitation voltages of 1, 3, 5 and 7 V. CMC based actuator loaded with 1.5 g PEG exhibited the largest tip displacement among other actuators for each excitation voltage. The PEG loading did not lead to considerable differences in tensile strength of CMC-based films However, Young's modulus decreased with PEG loading.Öğe Effects of PEG loading on electromechanical behavior of cellulose-based electroactive composite(Springer, 2015) Ozdemir, Okan; Karakuzu, Ramazan; Sarikanat, Mehmet; Akar, Emine; Seki, Yoldas; Cetin, Levent; Sen, Ibrahim; Gurses, Baris Oguz; Yilmaz, Ozgun Cem; Sever, Kutlay; Mermer, OmerElectroactive behavior of carboxymethylcellulose (CMC)-based actuators was investigated in this study. CMC-based films were firstly fabricated by using 1-butyl-3-methylimidazolium bromide. Characterization studies of the CMC films were conducted by using Fourier transform infrared, X-ray diffraction analysis, thermogravimetric analysis, scanning electron microscopy, and tensile testing. CMC-based actuator films were produced by gold coating on both surfaces of CMC-based films Polyethylene glycol (PEG) at different loadings (1, 1.5 and 2 g) was used to improve electroactive behavior of CMC based actuators. Maximum tip displacements were obtained under DC excitation voltages of 1, 3, 5 and 7 V. CMC based actuator loaded with 1.5 g PEG exhibited the largest tip displacement among other actuators for each excitation voltage. The PEG loading did not lead to considerable differences in tensile strength of CMC-based films However, Young's modulus decreased with PEG loading.Öğe Effects of PEG loading on electromechanical behavior of cellulose-based electroactive composite(Springer, 2015) Ozdemir, Okan; Karakuzu, Ramazan; Sarikanat, Mehmet; Akar, Emine; Seki, Yoldas; Cetin, Levent; Sen, Ibrahim; Gurses, Baris Oguz; Yilmaz, Ozgun Cem; Sever, Kutlay; Mermer, OmerElectroactive behavior of carboxymethylcellulose (CMC)-based actuators was investigated in this study. CMC-based films were firstly fabricated by using 1-butyl-3-methylimidazolium bromide. Characterization studies of the CMC films were conducted by using Fourier transform infrared, X-ray diffraction analysis, thermogravimetric analysis, scanning electron microscopy, and tensile testing. CMC-based actuator films were produced by gold coating on both surfaces of CMC-based films Polyethylene glycol (PEG) at different loadings (1, 1.5 and 2 g) was used to improve electroactive behavior of CMC based actuators. Maximum tip displacements were obtained under DC excitation voltages of 1, 3, 5 and 7 V. CMC based actuator loaded with 1.5 g PEG exhibited the largest tip displacement among other actuators for each excitation voltage. The PEG loading did not lead to considerable differences in tensile strength of CMC-based films However, Young's modulus decreased with PEG loading.Öğe Electromechanical characterization of multilayer graphene-reinforced cellulose composite containing 1-ethyl-3-methylimidazolium diethylphosphonate ionic liquid(Walter De Gruyter Gmbh, 2017) Akar, Emine; Seki, Yoldas; Ozdemir, Okan; Sen, Ibrahim; Sarikanat, Mehmet; Gurses, Baris Oguz; Yilmaz, Ozgun Cem; Cetin, Levent; Sever, KutlayIn this study, multilayer graphene (Gr)-reinforced cellulose composites were synthesized by using 1-ethyl-3-methylimidazolium diethylphosphonate ionic liquid. The composites were fabricated via dissolving the cellulose in 1-ethyl-3-methylimidazolium diethylphosphonate and Gr loading at different ratios (0.2, 0.4, and 0.6 wt.%). Both sides of the composites were coated with gold leaf to generate electrodes. The effect of Gr loading on chemical functional groups, crystallographic properties, thermal stability, and morphological and mechanical properties of cellulose film was investigated by Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetric analysis, scanning electron microscopy, and tensile test, respectively. Electromechanical behavior of the cellulose composite films reinforced with Gr (0.2, 0.4, and 0.6 wt.%) was investigated under DC excitation voltages of 1, 3, 5 and 7 V. Gr loading of 0.2 wt.% increased maximum tip displacement by 400% when the actuator is excited with 3 V.Öğe Electromechanical performance of chitosan-based composite electroactive actuators(Elsevier Sci Ltd, 2016) Altinkaya, Emine; Seki, Yoldas; Yilmaz, Ozgun Cem; Cetin, Levent; Ozdemir, Okan; Sen, Ibrahim; Sever, Kutlay; Gurses, Baris Oguz; Sarikanat, MehmetA novel chitosan-based electroactive actuator was fabricated by using chitosan, N, N'-methylenebisacrylamide (MBA), poly (diallyldimethylammonium chloride), and gold metal. The constructive effect of crosslinker to the actuator performance was investigated by using various amounts of MBA. The chitosan-based film samples were characterized using Fourier transform infrared analyses, X-ray diffraction analysis, thermogravimetric analysis, scanning electron microscopy analysis, and tensile test. The viscoelastic properties of films were determined by dynamic mechanical analysis. The motion and force generation capabilities and the repeatability of the actuators were also investigated under electrical stimuli up to 21 V. The suitability of the prepared chitosan-based films to be used as actuator for soft robotic applications is verified experimentally. (C) 2016 Elsevier Ltd. All rights reserved.Öğe Experimental Investigation of Thermoelectric Self-Cooling System for the Cooling of Ultrasonic Transducer Drivers(Gazi Univ, 2022) Şener, Mert; Arslan, F. Mertkan; Gurses, Baris Oguz; Gurlek, GokhanElectronic driver circuits are used for the driving of ultrasonic transducer systems. Due to the high frequency switching, thermal management is the main problem that has a significant effect on the reliability of the driver. Different applications are being studied to solve such overheating problems. In this study, the designed thermoelectric self-cooling system dissipates the excess heat generated in the push-pull drive circuit and improves system performance. Thermoelectric self-cooling (TSC) is a new thermoelectric application which provide the cooling of any heat-generating device without electricity consumption. This paper presents the experimental analysis of a TSC system. An experimental setup is designed on a 275W push-pull ultrasonic driver circuit. In this study, it has been shown how the performance of the thermoelectric system changes with the use of cold extender of different thicknesses. 5 and 10 mm thickness cold extenders have had a positive effect on the cooling performance of both the hot and cold surfaces of the self-cooling system. However, when the thickness of the cold extender is increased beyond the threshold, the heat capacity of the cold extender has prevented the temperature between the cold and hot surfaces to reach critical temperature differences which enables the fan to operate.Öğe Investigation of the effects of PWM parameters on ionic polymer metal composite actuators(Iop Publishing Ltd, 2014) Yilmaz, Ozgun Cem; Cetin, Levent; Gurses, Baris Oguz; Sen, Ibrahim; Ozdemir, Okan; Sarikanat, Mehmet; Seki, Yoldas; Sever, Kutlay; Akar, Emine; Mermer, OmerThe effects of the PWM excitation signal parameters, such as frequency and magnitude, on the Nafion-based ionic polymer metal composite (IPMC) actuator response were found out. The first set of experiments was designed to observe the actuator response when the actuators were biased with constant DC voltages. These experimental results were exploited to build an experimental data based dynamic model. The model and these results were also used as references to evaluate the experimental results in the proceeding experiments. The second set of experiments was designed to observe the actuator response when the DC square wave signals at different frequencies (0 to 1000 Hz) were applied. The third set of experiments was designed to observe the actuator response when the PWM signals at different magnitudes (6, 8 and 10 V) were applied. It is observed that back relaxation reduces with increasing frequency, but after a certain frequency value, it remains approximately constant. It is seen that the input output relationship of the actuators are linear only for a range of PWM signal magnitudes. The observations in both the PWM frequency and the magnitude experiments indicated that the performance of the Nafion-based IPMC actuator could be improved by selecting a magnitude of PWM signals between 6-8 Volts and by selecting a frequency between 400-1000 Hz.Öğe Is Manual Segmentation the Real Gold Standard for Tooth Segmentation? A Preliminary in vivo Study Using Cone-beam Computed Tomography Images(Galenos Yayincilik, 2021) Sabanci, Sercan; Sener, Elif; Turhal, Rukiye Irmak; Gurses, Baris Oguz; Govsa, Figen; Tekin, Ugur; Baltaci, AysunObjective: This study aimed to assess whether manual segmentation is an accurate method in tooth volume measurement and to compare the outcomes of manual, automatic, and semiautomatic segmentations on cone-beam computed tomography (CBCT) images by comparing each system with the water displacement method, which is the gold standard. Materials and Methods: CBCT images of l0 maxillary impacted teeth were used in this preliminary in vivo study. Following the acquisition of CBCT scans, manual, automatic, and semiautomatic segmentations were completed by the same operator. After surgical removal, the volumes of all impacted teeth were measured with the water displacement method, which was used as the gold standard. The volume of each segmented image was measured in mm(3) using the 3D-Doctor software. The established volumes of each segmented image were compared with those of the gold standard using the 95% confidence interval bootstrap percentiles. Intraobserver reliability was determined using the intraclass correlation coefficient. Results: All segmentation methods revealed significantly different volume values both from the gold standard and from each other (p=0.000). The semiautomatic segmentation demonstrated comparable performance with the manual method, and both systems provided comparable volumes with the gold standard than did the automatic method. Excellent intra-observer intraclass correlations were found for all protocols. Conclusion: The actual volumes of the specimen were not obtained by manual, semiautomatic, and automatic segmentations. Semiautomatic segmentation demonstrated comparable performance to the manual method, whereas automatic segmentation yielded the poorest values. The automatic and semiautomatic segmentations may be improved by the development and utilization of novel or hybrid segmentation algorithms for a faster process and more accurate results.
