International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

This paper investigates the inverse problem for thermal bridges – determining design parameters (such as material, geometry, thermal resistance R of the components) of the bridge at a known Psi-factor. By using artificial neural networks, a thermal bridge type IF (wall-floor connection) has been considered to evaluate the effectiveness of the methodology. The results show that the approach provides a fast and accurate way to predict the optimal parameters that meet specific energy efficiency requirements. In the future, this approach could help to determine the parameters of thermal bridges using thermographic images non-invasively.

The main purpose of the study was to assess the usability of a new calculation algorithm for determining the surfactants effective diffusion coefficient. The adsorption of a mixture of non-ionic surfactants onto flat water-air interface was considered. Presented algorithm is composed of a two parts: Ward-Tordai equation solver based on Nyström method for integral equations and golden ratio optimization method used in inverse problem. In the investigation the Langmuir model of an isotherm was assumed. Presented algorithm was successfully used to determine the non-ionic surfactant – Nafol 810D (BRENNTAG) effective diffusion coefficient in the diffusion controlled adsorption process.

The direct problem in ultrasonic testing (UT) is: “Evaluation of attenuation coefficient by means velocity of ultrasonic wave propagation, frequency and grain size in polycrystalline materials”. The inverse problem in UT is formulate as “Non-destructive evaluation of grain size by measurement of acoustical characteristics”. The values of acoustical characteristics (V V f ) L T L ; ;α ; are measured, according ASTM E 494:2015. In this article a equation for grain size (D) is derived.

The objective of this paper is to determine temperature dependent heat transfer coefficient for the characterization of building porous materials in the range 20 – 60ºC, using the approach based on the solution of the inverse heat transfer problem and the results of measuring boundary conditions. The Levenberg–Marquardt iteration algorithm in software MATHEMATICA is applied to solve nonlinear system of algebraic equations resulting from the sensitivity matrix. The surface temperature distribution is measured using the infrared camera.