Effective ecological and cheap heating of dwelling spaces

The sustainability of human civilization depends largely on green energy management. This work represents one way to achieve this goal. The work is devoted to converting microwave radiation to heat. The article analyses different ways of heating residential and utility areas. Materials suitable for converting microwave radiation to heat from ceramic composites, concretes, fire clays, and bauxite with water glass are enclosed. For all materials we have measured DTA/TG (Differential Thermal Analysis/Thermogravimetric Analysis) curves, XRD (X-Ray Diffraction) patterns, chemical composition of samples, the specific heat capacity c(p) [J/kg.K], thermal conductivity k [W/m.K] and diffusivity alpha [m(2)/s(-1)]. The cooling curves of these materials after microwave heating are characterized in detail. The paper also presents a description and construction of a microwave reactor together with the parameters of the living space heating.Web of Science121art. no. 5

Sensitivity analysis: A tool for tailoring environmentally friendly materials

In this article, we examine the use of sensitivity analysis for the optimization of selected physical properties in rubber compounds and determine objective criteria which allow for the reduction of environmental load during rubber compound production. The sensitivity analysis shows how significantly each input value affects the output value, and the response graphs express the effect of the selected parameter on the output value. The solutions described in the article are applicable to other production technologies. We present a sensitivity analysis based on the prediction of selected mechanical properties of rubber mixtures composed of Standard Malaysian Rubber (SMR). Two blends were pre- pared by mixing SMR and oleic acid and different concentrations of surfactant (2, 4, 6, 8, 10, 20, 30 wt%). Tensile strength Rm and moduli M100, M200, M300 were measured and evaluated. The sensitivity analysis showed the significance of certain ingredients which affect the measured mechanical properties.Web of Science208art. no. 11803

Prediction of the Effect of CO2 Laser Cutting Conditions on Spruce Wood Cut Characteristics Using an Artificial Neural Network

In addition to traditional chip methods, performance lasers are often used in the field of wood processing. When cutting wood with CO2 lasers, it is primarily the area of optimization of parameters that is important, which include mainly laser performance and cutting speed. They have a significant impact on the production efficiency and cut quality. The article deals with the use of an artificial neural network (ANN) to predict spruce wood cut characteristics using CO2 lasers under several conditions. The mutual impact of the laser performance (P) and the number of annual circles (AR) for prediction of the characteristics of the cutting kerf and the heat affected zone (HAZ) were examined. For this purpose, the artificial neural network in Statistica 12 software was used. The predicted parameters can be used to qualitatively characterize the cutting kerf properties of the spruce wood cut by CO2 lasers. All the predictions are in good agreement with the results from the available literary sources. The laser power P = 200 W provides a good cutting quality in terms of cutting kerf widths ratio defined as the ratio of cutting kerf width at the lower board to the cutting kerf width at upper board and, therefore, they are optimal for cutting spruce wood at 1.210−2 ms−1