Yaşar Karabul

Polypropylene/basalt thick film composites: structural, mechanical and dielectric properties

Abstract In this work, polypropylene/volcanic basalt rock (PP/VBR) thick film composites with different VBR powder mass ratio varying from 0.5 wt.% to 20.0 wt.% were prepared by using the hot press technique. The effects of VBR powder doping on mechanical, structural and dielectric properties of PP were investigated by stress-strain measurements, Fourier transform infrared analysis, thermal gravimetric analysis, scanning electron microscopy and dielectric spectroscopy methods. The highest tensile strength, percentage strain and energy at break were achieved for 0.5 wt.% VBR powder doped PP composite. According to the stress-percentage strain curves of the samples, it was observed that 0.5 wt.% VBR powder doping increases the mechanical performance of PP polymer. In addition, regardless of the doping concentration level of basalt powder, the real part of complex dielectric function (ε′) of all PP composites display approximately frequency independent behavior between 100 Hz and 1 MHz. On the other hand, 0.5 wt.% VBR powder doped PP composite has also the lowest dielectric constant at the vicinity of 2.7 between 100 Hz and 1 MHz. The composite also has considerably low dielectric loss which has a crucial importance for technological applications. For these reasons, PP/0.5 wt.% VBR composite with the highest tensile strength can be considered as a suitable candidate for microelectronic devices. Furthermore, the alternative current conductivity mechanism was determined as nearly constant loss due to approximately constant dielectric loss between 10 Hz and 1 MHz.

ZXCOM: a software for computation of radiation sensing attributes

ABSTRACT The main objective of this study is presentation of a new version of ZXCOM software that can calculate the effective atomic number , the effective electron density , and the elastic (Rayleigh) to inelastic (Compton) scattering ratio , for any element, compound, or mixture at energies from 1 keV to100 GeV, over an interval of scattering angles extending from 0° to 180°. The ZXCOM runs under the MS Windows® operating system. It provides a useful interface that simplifies defining and redefining materials and experimental conditions. As an application of ZXCOM software, the and of some thick metal-oxide films, TMOFs (In2O3, WO3, Nb2O5, Cr2O3, SmCoO3, NiO, ZnO, Zn2SnO4, SnO2, CeO2, SmFeO3, TiO2, and LiCoO2), were calculated. The software created in this study can be used as a reliable and fast tool for the determination of the above parameters that are essential in a wide range of applications such as radiation shielding, radiotherapy, technology, etc.

Effect of borax additive on the dielectric response of polypyrrole

The main aim of this study is to produce added polypyrrole (PPy) borax composites with high dielectric properties for technological applications. For this purpose, PPy–borax composites with different borax concentrations varying from 10 to 50 wt% have been prepared. To reveal their structural and morphological attributes, the composites have been characterized by Fourier-transform infrared spectroscopy and scanning electron microscopy. The real and imaginary parts of complex dielectric function, the imaginary component of complex electrical modulus and ac conductivity have been investigated at room temperature as a function of frequency in the range 100 Hz–15 MHz. It has been found that addition of borax increases the dielectric constant of pure PPy. In this respect, PPy–borax composites with the highest dielectric constant at low frequency may be utilized in charge storing devices. On the other hand, the dielectric loss is also very high in low-frequency region for the composites with high borax content. Exploiting this property, the material may also be used in decoupling capacitor applications. The relaxation mechanisms of the samples have also been determined as non-Debye type. The Nyquist curves of the samples have been analysed for calculating the grain and grain boundary resistance and capacitance values. In conclusion, borax has a promising potential to be used as a cheap and effective filler for improving the dielectric properties of PPy polymer.

Sodium meta silicate doped PPy and PT composites with giant dielectric constant

In recent years, scientists have focused on searching new dielectric materials due to increasing necessity of high dielectric constant materials for microelectronic applications. Especially, developing a new high dielectric constant materials with low cost and weight has a crucial role in power electronic systems. From this point of view, conducting polymer/mineral composites have been prepared for achieving high dielectric constant material in this work. The dielectric and ac conductivity properties of the polypyrrole/sodium metasilicate (PPy/Na2SiO3) and polythiophene/sodium metasilicate (PT/Na2SiO3) composites have been determined by impedance spectroscopy measurements performed between 100 Hz-15 MHz. The highest dielectric constants have been obtained as 105 and 107 for PPy and PT composites with weight percentages of 10% and 50% Na2SiO3 doping, respectively. The relaxation mechanism of the composites have also been analyzed by the frequency dependence of imaginary component of complex electrical modulus. In addition, ac charge carrier transport mechanism of the samples have been investigated.

Structural and dielectric properties of Europium based copper oxide layered perovskite material

ABSTRACT In this study, EuBa2Cu3O7+x (coded as Eu-123) material was synthesized by solid state reaction method and its chemical and physical properties were determined by FTIR, XRF, TGA and DTA techniques. The dielectric and impedance properties of Eu-123 were determined by HP-4194A Impedance Analyzer at room temperature. Eu-123 displays negative dielectric constant (NDC) property, which has a crucial importance for producing metamaterials. Moreover, the relaxation process of the material was also determined as pure conduction. In addition, it was revealed that application of magnetic field does not affect the NDC property of the sample but slightly changes the values of ϵ ′.

Study of the electron densities of some food products dried using the new method

ABSTRACT The main goal of this study was to determine the concentrations of P, S, Cl, K, Ca, and Sr in food samples using a newly developed drying method to find their electron densities. The methods applied to samples to find the effective drying method were as follows: “drying in oven under a magnetic field” and “drying under the sun and a magnetic field.” Concentrations of elements were determined by an energy dispersive X-ray fluorescence spectrometer soon after initial processing of dried foods. The concentrations of elements were acquired as mg/kg. An attempt was made to calculate the electron densities of the dried samples. The electron densities of food samples dried in oven under a magnetic field as the effective one were identified using ZXCOM software. This particular attempt is fairly new, and there is no information in this field. The electron density (Neff) values of the dried samples were calculated for all samples of interest. The electron densities of fig samples dried with the new method suggested in this study were found to be highest among all samples of interest.