Brno University of Technology

About: Brno University of Technology is a education organization based out in Brno, Czechia. It is known for research contribution in the topics: Computer science & Fracture mechanics. The organization has 6339 authors who have published 15226 publications receiving 194088 citations. The organization is also known as: Vysoké učení technické v Brně & BUT.

Towards a micro-system for monitoring ethylene in warehouses

Abstract: By means of an adapted screen-printing technique, sensitive layers of tin and tungsten oxide (pure and doped with 1% in weight of Au, Pt and Pd) were deposited on silicon micromachined substrates with low thermal inertia. Each chip contains four membranes with different active layers. The sensor response to ethylene, ethanol, ammonia and their binary mixtures was studied. The sensor reaction to humidity was also investigated. A 4-element microsensor array is designed (by selecting the active materials and noble metal loading) to selectively detect ethylene, ethanol, ammonia and their binary mixtures. It is shown that these species can be easily discriminated, even at low concentrations (1 ppm), which makes the microarray designed suitable to monitor climacteric fruit during storage in warehouses or storage chambers.

Comparative Study of Discrete Component Realizations of Fractional-Order Capacitor and Inductor Active Emulators

Abstract: Due to the absence of commercially available fractional-order capacitors and inductors, their implementation can be performed using fractional-order differentiators and integrators, respectively, c

Effect of Process Parameters and High-Temperature Preheating on Residual Stress and Relative Density of Ti6Al4V Processed by Selective Laser Melting

Abstract: The aim of this study is to observe the effect of process parameters on residual stresses and relative density of Ti6Al4V samples produced by Selective Laser Melting. The investigated parameters were hatch laser power, hatch laser velocity, border laser velocity, high-temperature preheating and time delay. Residual stresses were evaluated by the bridge curvature method and relative density by the optical method. The effect of the observed process parameters was estimated by the design of experiment and surface response methods. It was found that for an effective residual stress reduction, the high preheating temperature was the most significant parameter. High preheating temperature also increased the relative density but caused changes in the chemical composition of Ti6Al4V unmelted powder. Chemical analysis proved that after one build job with high preheating temperature, oxygen and hydrogen content exceeded the ASTM B348 limits for Grade 5 titanium.