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Öğe Analysis of electromagnetic properties of Ce-Zn substituted barium hexaferrite for electronic circuit applications(Elsevier, 2022) Okutan, M.; Ozturk, M.; Kirsoy, A.; Araz, I; Yener, T.; Yalcin, O.Electromagnetic properties of Ce-Zn substituted barium hexaferrite (Ba0.5Ce0.5ZnFe11O19 ferrite) synthesized using ceramic technique were analyzed in detail in the X band frequencies to describe its response to microwave absorber and microwave electronic device applications. The phase formations, structural morphology, polarization mechanisms and magnetic properties for Ba0.5Ce0.5ZnFe11O19 ferrite, which provide important information about electrical load transmission mechanism were analyzed using X-ray diffraction, scanning electron microscopy, two-port vector network analyser and vibrating sample magnetometer techniques, respectively. The experimental complex dielectric plane plots (Cole-Cole plots) of the Ba0.5Ce0.5ZnFe11O19 ferrite represent an equivalent RC circuit corresponding to the impedance circuit in the Smith Chart. The reflection loss increased to the highest value (-17.04 dB) depending on the amount of Ce in the structure of the Ba0.5Ce0.5ZnFe11O19 ferrite and the bandwidth, which is important for microwave absorbers, increases.Öğe Analysis of the effect of low dye concentration for electrical system applications of reactive red 45 dye loaded hydrogels(Elsevier, 2022) Ozturk, M.; Coskun, R.; Okutan, M.; Yalcin, O.; Kirsoy, A.Structural, optical and dielectric properties determining the conduction mechanism were investigated using appropriate measurement techniques to determine the suitability of low-concentrations (LC) (1000 mu L, 500 mu L, 250 mu L and 125 mu L) reactive red 45 (RR-45) dye loaded hydrogels for electrical circuit applications. The UV spectra of the all samples displayed a fluctuating behaviour depending on the concentration. It was found that the dielectric plane plots for all the samples are compatible with the Cole-Cole relaxation model and correspond to an equivalent electrical circuit (RC) representing with the impedance circuit in the Smith Chart. It was concluded that RR-45 dye loaded hydrogels could be a suitable material for electrodes used in electroenceph-alography and electrocardiography systems due to the decrease of the real part of complex dielectric constant and impedance values with increasing frequency. The s-parameter for the samples, which determines the con-ductivity mechanism, was calculated separately for different regions.Öğe Comparison Effects and Dielectric Properties of Different Dose Methylene-Blue-Doped Hydrogels(AMER CHEMICAL SOC, 2013) Yalcin, O.; Coskun, R.; Okutan, M.; Ozturk, M.The dielectric properties of methylene blue (MB)-doped hydrogels were investigated by impedance spectroscopy. The real part (epsilon') and the imaginary part (epsilon '') of the complex dielectric constant and the energy loss tangent/dissipation factor (tan delta) were measured in the frequency range of 10 Hz to 100 MHz at room temperature for pH 5.5 value. Frequency variations of the resistance, the reactance, and the impedance of the samples have also been investigated. The dielectric permittivity of the MB-doped hydrogels is sensitive to ionic conduction and electrode polarization in low frequency. Furthermore, the dielectric behavior in high-frequency parts was attributed to the Brownian motion of the hydrogen bonds. The ionic conduction for MB-doped samples was prevented for Cole-Cole plots, while the Cole-Cole plots for pure sample show equivalent electrical circuit. The alternative current (ac) conductivity increases with the increasing MB concentration and the frequency.Öğe Determination of the effects of the production process for the calcite doped hydrogels on electronic circuit applications(Elsevier, 2021) Yalcin, O.; Ozturk, M.; Okutan, M.; CoSkun, R.; Oncan, M.The effects of the production process on the dielectric, optical, conductivity, structural and morphological properties of calcite doped hydrogels were investigated in this study. For this purpose, the X-ray diffraction, scanning electron microscope, non-destructive energy dispersive X-ray, dielectric and UV-Vis spectroscopy of Calcite I and Calcite II samples synthesized by different production processes were performed in the special ranges. The dielectric characteristic of the both samples were found to behave in compatible with the MaxwellWagner theory associated with the electrode and interface polarization in the low frequency region. In the high frequency region, it was determined that the effect of the Koop's theory and the Brownian motion on the conductivity mechanism of calcite I and calcite II. It was found that the calcite II sample with high capacitive property had high conductivity values in the entire frequency range. It was observed that the Log sigma ac values defined by the Correlated Barrier Hoping mechanism and the Super Linear Power Law conductivity mechanisms of the Calcite II sample with high capacitive properties was taken high in the entire frequency range. The quantum confinement and the Fermi-Dirac dispersion effects of the calcite molecules were thought to have an effect on the determination of the optical energy gaps (Eg) of samples. It was determined that the plane plots of the complex electric modulus for the Calcite I and Calcite II samples, which were compatible with the DavidsonCole and the Havriliak-Negami relaxation models, respectively, corresponded to different equivalent RC circuits. Based on these results, it was found that the production process of the calcite-doped hydrogels is extremely important on the electronic circuit applications.Öğe Dielectric properties of Rhodamine-B and metal doped hydrogels(ELSEVIER SCIENCE BV, 2015) Okutan, M.; Coskun, R.; Ozturk, M.; Yalcin, O.The electric and dielectric properties of Rhodamine-B (RB) and metal ions (Ag+, Co2+, Cr3+, Mn2+ and Ni2+) doped hydrogels have been analyzed in an extended frequency range by impedance spectroscopy. The RB doped hydrogels has been found to be sensitive to ionic conduction and electrode polarization according to the metal doped hydrogels. We have shown that the ionic conductive of RB doped hydrogels is originated from the free ions motion within the doped hydrogels at high frequency. We have also Laken into account the Cl- and N+ ions in the structure of RB provide additional ionic contribution to RB doped hydrogels. (C) 2014 Elsevier By. All rights reserved.Öğe Equivalent circuit properties of organic food extracts doped hydrogels and their applications in bioelectronics(Elsevier, 2021) Okutan, M.; Coskun, R.; Ozturk, M.; Yalcin, O.; Toker, C.Dielectric/electrical properties of organic food extracts doped hydrogels, which can be envisaged to lead the technology applications of biosensors, bio-imaging and wireless biological sensing schemes in bioelectronic circuits, were analysed at room temperature by means of impedance spectroscopy. Electrode and interfacial polarization mechanisms were determined to be dominant on the dielectric properties of pure and organic food extracts doped hydrogels in the low frequency region. Dielectric relaxation, viscoelastic mechanism, Brownian motion of food extract molecules and Maxwell-Wagner approach were used to explain the dielectric properties of the samples in the high frequency region. It was determined that the dielectric plane plots that provide information about the transmission mechanism of all samples are compatible with the Cole-Cole relaxation models. The conductivity characteristics of the all samples depending on the s parameter/power law exponent were explained for the three different regions by dc conductivity, the Correlated Barrier Hoping conductivity and Quantum Mechanical Tunnel conductivity models, respectively. From the experimental results obtained in this study, it was concluded that organic food extracts doped hydrogels are an inspirational material for applications such as biosensors, bio imaging and wireless bio-sensing device that can be used in bio-systems. (C) 2021 Elsevier B.V. All rights reserved.Öğe Evaluation of the effect of dose change of Fe3O4 nanoparticles on electrochemical biosensor compatibility using hydrogels as an experimental living organism model(Elsevier, 2021) Ozturk, M.; Okutan, M.; Coskun, R.; Colak, B.; Yalcin, O.Morphological, structural, optical and dielectric properties, which provide important information about the technological applications of pure and different dose (2.5%, 5.0%, 7.5% and 10.0%) Fe3O4 nanoparticles (NPs) doped hydrogels were analyzed in detail in this study. The complex dielectric parameters of all the samples are related to the electrode/interface polarization (grain boundary), dielectric relaxation and grain effects in accordance with the Maxwell-Wagner theory and Brownian motion in the broadband frequency regions. Experimental plane plots of the complex electrical modulus for all the samples are explained by the Havriliak and Negami relaxation model represented by two relaxation times (alpha and gamma) associated with resistances created by grain boundary (alpha) and grain (gamma). In the high frequency region, complex electrical modulus plane plots of all the samples were compatible with the Cole-Cole relaxation model corresponding to the equivalent electrical circuit (RC) in the Smith Chart diagram. Koop's theory and electron hopping mechanism formed between Fe3+ and Fe2+ ions in the octahedral lattice are effective on the electrical conductivity values of the samples. As the molarity of Fe3O4 NPs increased, the logarithmic conductivity values of all samples, which a function of the angular frequency and defined by the Jonscher Power Law, Nearly Constant Loss and Super Linear Power Law conductivity mechanisms, were generally increased. From the experimental results, it was concluded that the hydrogels with high doses of Fe3O4 NPs can be used as an electrochemical biosensor in bio-systems since it has the high dielectric, capacitance, low impedance and conductivity values. (c) 2020 Elsevier B.V. All rights reserved.Öğe Experimental model to describe the dielectric response of different dye and nanoparticles doped hydrogels for biological cell membranes and biological systems(Elsevier, 2019) Coskun, R.; Okutan, M.; Ozturk, M.; Yalcin, O.Doped hydrogels with Methylene-Blue (MB), Rhodamine-B (RB), MB/RB dyes and NiFe2O4 nanoparticles (NPs) were developed as an experimental model to describe the dielectric/electric response of lipid matrix in biological cell membranes and biological systems. Hydrogels synthesized by polymerization technique are highly suitable for three-dimensional cell models due to biocompatible structure. Frequency and bias voltage evolution of dielectric and electrical parameters for all samples have been characterized by the impedance spectroscopy at room temperature (RT). Absorbance spectrum and energy band gap for all samples have been analyzed with UV-Vis absorption spectroscopy. The frequency and applied bias voltage dependence of experimental dielectric/electric properties for all samples were attributed to the basis of Kroop's theory, Maxwell-Wagner approach, viscoelastic mechanism and the micro Brownian motion of free ions. It was obtained that the absorbance spectrum values for all samples are associated with Lambert-Beer-Bouguer's law and innervation of the dipolar oscillations/quadrupoles of dye and NPs ions. The smallest and highest values of the absorption spectra were recorded for MB/RB dye and NiFe2O4 NPs doped hydrogels with respectively. Results from the complex impedance based Cole-Cole plots and their Smith Chart adaptation showed that MB/RB dye doped hydrogels has the largest semi-circle due to it has the highest relaxation times and the smallest absorption coefficient. The NiFe2O4 NPs doped hydrogels with the highest absorption value were found to be the most suitable samples for optoelectronic applications in the biological cell membranes. The MB/RB dye doped hydrogels were concluded to be the most suitable material for impedance applications due to have the greatest relaxation time in the Cole-Cole plots. It determined that all of all samples except RB doped hydrogels are exhibited Ohmic behaviour from the I-V characteristic analysis. The conductivity properties (from the power law exponent) in 1th region, the 2nd region and the 3rd region for dyes/NiFe2O4 NPs doped hydrogels were associated with the dc conductivity, the Correlated Barrier Hoping (CBH)/Quantum Mechanical Tunnel (QMT) conductivity and the Correlated Barrier Hoping model with respectively. It is concluded that RB dye doped hydrogels can be used as a model for biomedical devices and drug delivery system applications, because they have the highest dielectric and superior conductivity properties. Also, different cationic dyes and NiFe2O4 NPs doped hydrogels were found exciting in applications such as low-cost bio-flexible sensors, green electronics and health monitors that have in low-voltage-operating. (C) 2019 Published by Elsevier B.V.Öğe Impedance properties and comparison effects of different dose safranin doped hydrogels(Elsevier, 2017) Coskun, R.; Yalcin, O.; Okutan, M.; Ozturk, M.Frequency evolution of dielectric characteristics of different dose safranin (SR) doped hydrogels was studied by impedance spectroscopy (IS) at room temperature (RT). Real and imaginary parts of complex dielectric constant, impedance, electric modulus and conductivity of SR doped hydrogels were analyzed in the frequency range of 100 Hz to 40 MHz for pH 5.0 value. Phase angle, capacitance, surface resistivity, tangent factor (tan 8) for all samples were recorded with the same frequency range. Surface and bulk polarization effects wete donlinant on impedance at low and high frequency regime, respectively. Fluctuation effect of SR doped hydrogels was observed from the dielectric measurements. Tutorial of radio frequency, RF, impedance matching were realized by using the Smith chart. The coulomb interaction between SR-cations and hydrogels may be anticipated to enhance the organic electrical performance. The potential applications of SR doped hydrogels were presented to microbial fuel cells. (C) 2017 Elsevier B.V. All rights reserved.Öğe Investigation of Optical and Flow Properties of Avocados by Spectroscopy and Rheology Methods(Polish Acad Sciences Inst Physics, 2022) Yalcin, O.; Ozturk, M.; Gorguluer, O.Structural, optical and rheological properties of pulp and seed extracts of three different avocado cultivars were analyzed using spectroscopy and rheology techniques at room temperature. Ultraviolet spectra and Fourier transform infrared spectroscopy signals for the pulp and avocado seed extracts were recorded in the wavelength range 190-600 nm and the wave number range 4200-400 cm, respectively. The flow behaviours for all avocado pulp and seed samples were also analysed in the shear rate range of 10(-2) - 10(2) s(-1) and in the frequency range of 10(-1) - 10(3) rad/s, respectively. The ultraviolet spectra of all the samples were observed as two peaks around 210 and 290 nm. The optical energy band gaps for all samples were found to be consistent with Planck's radiation approach.Öğe Investigation of the traditional organic vinegars by UV-VIS spectroscopy and rheology techniques(Pergamon-Elsevier Science Ltd, 2021) Yalcin, O.; Tekgunduz, C.; Ozturk, M.; Tekgunduz, E.Optical, rheological and metabolic properties of the apple, hawthorn, artichoke, grape, rosehip and blackberry organic vinegar produced by deep culture method (handmade traditional method) were analysed using UV-Vis spectroscopy and rheology techniques. Flow behaviours for all samples were analysed in the shear rate range of 10(-3) to 10(3) 1/s and in frequency range of 10(-3) to 10(3) rad/s, respectively. Absorption spectra for six organic vinegars was observed two peaks around 215 and 285 nm due to the presence of phenolic compounds and organic acids such as acetic. The effects of optical transitions of organic molecules on the absorption coefficient values for vinegars were determined. Optical energy band gaps of all samples were found to be consistent with Planck's radiation approach known as Rayleigh-Jeans law and Tauc law. The rheological/flow properties of the all vinegars were found to be relevant with non-Newtonian flow behaviour and Ostwald-de Waele model. From the results of optical and rheological analysis, which determines the quantity and quality characteristics of all organic vinegars, it was concluded that these vinegars are in a level that people can drink easily. (c) 2020 Published by Elsevier B.V.Öğe Origin of the effects of optical spectrum and flow behaviour in determining the quality of dry fig, jujube, pomegranate, date palm and concentrated grape vinegars(Pergamon-Elsevier Science Ltd, 2022) Ozturk, M.; Yalcin, O.; Tekgunduz, C.; Tekgunduz, E.In this study, we focused on physical characterization and quality control of dry fig, jujube, pomegranate, date palm and concentrated grape vinegars using UV spectroscopy method and rheology technique. The optical spectra and flow behaviour of the vinegars were analysed in detail in the selected specific wavelength, shear rate and frequency ranges, respectively. It was determined that the peak values seen in the UV spectra of the vinegars were caused by the organic acid and phenolic compound concentration. The peak values in the UV spectra of the vinegars wavelength range of 190 nm to 240 nm and 250 nm to 300 nm were caused by the organic acid and phenolic compound concentration, respectively. In this context, it was predicted that concentrated grape vinegar, which has the highest absorbance value, has higher organic acid content and more antibacterial/antioxidant properties compared to the others. It is thought that the optical energy gaps of vinegars are related to the organic acid concentration and the release time. Flow properties of the vinegars were non-Newtonian thickening fluids (dilatant fluids) and compatible with the Power law model. The stable flow of the vinegars in the high shear rate region was interpreted as having a successful production process and being of good quality. (C) 2021 Published by Elsevier B.V.
