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Microwave techniques, as an indirect approach, can be applied for analyzing water content in honey by way of permittivity measurements. However, these techniques require proper calibration to accurately perform such indirect evaluation. Improper calibration standards used in this calibration process could naturally result in a reduction in the accuracy and thus the performance of dielectric characterization using microwaves. Self-calibrating microwave techniques can reduce the effects of imprecise standards and thus improve the performance of microwave measurements by bypassing the requirement of calibration standards. In this study, we develop a self-calibrating microwave measurement technique to determine the relative permittivity of honey samples and implement binary mixing models to predict adulteration levels of water-adulterated honey. From this implementation, it is observed that the parallel-capacitance mixing model could efficiently be applied to determine the concentration of water adulteration by examining the differences between absolute values of the real parts of the measured and predicted complex permittivities of adulterated honey.

A new microwave method is proposed for accurate determination of complex permittivity $\varepsilon _{\textrm {rs}} = \varepsilon _{\textrm {rs}}^{\prime }--j \varepsilon _{\textrm {rs}}^{\prime \prime }$ of soil samples inserted over a holder within the Electronic Industries Association (EIA) 1-5/8” coaxial measurement cell. Such a determination could be indirectly correlated with the volumetric moisture content of soil samples by microwave measurements. The method has three main advantages. First, it utilizes a simple calibration procedure involving uncalibrated measurements of an empty cell, the same cell loaded with a soil holder (a dielectric sample), and the same cell with a soil sample over this holder, thus eliminating the need for any formal calibration procedure. Second, it uses one measurement cell for extracting $\varepsilon _{\textrm {rs}}$ . Third, it does not require any numerical toolbox for determining $\varepsilon _{\textrm {rs}}$ . The method is validated by simulations of a synthesized soil sample and by experiments with a low-loss polyethylene sample. Its accuracy is examined in reference to: 1) two measurement cells with different lengths (length independence); 2) the position of the holder in the cell; and 3) an offset in sample length. Calibration curves (the volumetric moisture content $\theta _{V}$ versus $\varepsilon _{\textrm {rs}}^{\prime }$ ) obtained from fitting measured $\varepsilon _{\textrm {rs}}^{\prime }$ by our method to $\theta _{V}$ at 2 and 3 GHz are compared with other calibration curves in the literature for the analysis of the performance of the proposed method (PM). It is shown that calibration curves obtained from our method are similar to those obtained from other methods requiring complex calibration procedures.

AbstractThe aim of this study is to investigate the effect of working parameters on wear resistance of steels in terms of applied load, hardness and revolution per minute (rpm) using the Taguchi method. Pin-on-roller type of apparatus was used for adhesive wear tests. The operating parameters were investigated by employing the orthogonal array, signal-to-noise ratio and analysis of variance. The experimental wear test results show that the hardness of the materials is the major parameter among the controllable factors. After the hardness, the applied load and the rpm sequentially have influence on the wear resistance of three types of steels; AISI 1050, AISI 4140 and AISI 8620. The best wear testing parameters were determined for current conditions of the steels. A good agreement between the predicted and experimental wear amounts is observed.