A characterization method for characterization of thin films is proposed. Using the proposed cantilever method, piezoelectric coefficient d31 of thin film piezoelectric material on various samples was determined. Exact knowledge of geometry and material properties of cantilever and samples proved to be important in order to determine piezoelectric coefficients with sufficient accuracy. We studied the material properties with literature and measurements of Young modulus of the stainless steel cantilever. With numerical simulation we compared the measured results with computation.
COBISS.SI-ID: 7570516
It was demonstrated that by applying high-voltage nanosecond pulses to cells, plasma membrane and cell organelles are permeabilized. New Blumlein configuration that enables a higher repetition rate of variable duration of either bipolar or unipolar high-voltage pulses was designed. A maximal pulse repetition rate of 1.1 MHz was achieved. The new design of pulse generator was built, verified, and tested. The resulting flexibility and variability allow further in vitro experiments to determine the importance of the pulse repetition rate and pulse polarity on membrane permeabilization.
COBISS.SI-ID: 7346772
A case study of the appropriate SMD capacitor selection for high accuracy integrating A/D converter is presented. An overview of polymer dielectric materials is given with the emphasis on the commercial choice of SMD capacitors. The effect of dielectric absorption of the charge on the conversion error is theoretically analyzed for the intermittent mode of operation. Based on experiments, the influence of the capacitor’s parallel resistance on the conversion result was derived.
COBISS.SI-ID: 7570260
The analytical partial capacitance methods (PCM) are reviewed based on the challenges met during the development and tailoring (Ba, Sr)TiO3 thin films fabricated on different types of substrates. A correction for electrodes of finite thickness is introduced. Calculation results obtained with different models are compared against the results of FEM numerical simulation in the parameter range relevant for development of tuneable ferroelectric films. Guidelines for extending the applicability domain and for minimizing the inherent errors of the analytical models are presented.
COBISS.SI-ID: 22918695
Electrical impedance was measured ex vivo on 14 extracted human teeth using a QuadTech 1920 precision impedance analyzer. The optimal determination of the major apical foramen position was obtained at frequencies of 5 kHz and 0.5 kHz, 10 kHz and 0.5 kHz, and 5 kHz and 1 kHz, for the impedance ratios 0.73 (95% CI: -0.33 to 1.74 mm), 0.66 (95% CI: -0.34 to 1.81 mm) and 0.79 (95% CI: -0.33 to 1.58 mm) respectively. The limit of ±0.5 mm was attained in 86% of all measurements.
COBISS.SI-ID: 25834969