Narrow Results

We investigated a gas sensor that makes use of the surface plasmon resonance (SPR) effect in a thick layer of gold (Au), copper (Cu), ZnO, and multilayer black phosphorous (BP). The suitability of the proposed gas sensor was investigated for a range of analyte gases recognized for their toxicity, greenhouse effect, or flammability. The proposed gas sensor obtains a maximum sensitivity of 258.77°/RIU with a remarkable full width at half maximum (FWHM) of 7.12°, detection accuracy (DA) of 0.14/°, and Figure of merit (FoM) of 36.22. The result of our enhanced numerical analysis indicates that the performance of a multilayer BP is enhanced when compared to a conventional gas sensor. As a result, using a SiO₂ prism to sense different gases at a wavelength of 633nm, the suggested gas sensor may be more advantageous. Moreover, the maximum sensitivity of 374.31/RIU is obtained with a remarkable DA of 0.11° and FoM of 37.63/RIU to detect NO₂ gas sensing to maintain the $R_{\text{min}}$value. The gas sensor performance is high at different refractive indices for gas analyte (1–1.07). The performance of the proposed gas sensor is superior to that of the existing gas sensors.

Spurious numerical damping in the collocation boundary element method is considered for plane sound waves in two-dimensional ducts subjected to rigid and absorbing boundary conditions. Its extent is quantified in both conditions based on a damping model with exponential decay, and meshes of linear and quadratic continuous elements are studied. An exponential increase of numerical damping with respect to frequency is found and the results suggest an upper bound for given element-to-wavelength ratios. The quantification of numerical damping is required for evaluation of meshes covering a large number of waves, and real damping phenomena can be prevented from overestimation.

This study verified the relationship between fracture mechanics parameters (ΔK, ΔK_eff, K_max) and X-ray parameters (σ_r, B) for SG365 steel at elevated temperature up to 300°C. The fatigue crack propagation tests were carried out and X-ray diffraction technique according to crack length direction was applied to fatigue fractured surface. The residual stress on the fracture surface was found to increase in low ΔK region, reach to a maximum value at a certain value of K_max or ΔK and then decrease. The residual stresses were independent on stress ratio by arrangement of ΔK and full width at half maximums was independent by the arrangement of K_max. The equation of σ_r and ΔK was established by the experimental data. Therefore, fracture mechanics parameters could be estimated by the measurement of X-ray parameters.