Pavel Sedlák

Sorption characteristics of Amaranthus stems under storage conditions and water activity prediction.

Stems of amaranthus are considered as prospective biofuel in the Czech Republic. The study presents results of water sorption tests of this biomass in the range of 10-30 degrees C and water activity (a(w)) ranging from 0.4 to 0.99. The experimental procedure used was a gravimetric dynamic method. Four sorption models (Chung-Pfost, Halsey, Henderson, Oswin) were evaluated. The modified Hendersons equation was the best model for moisture adsorption and desorption of amaranthus stems. Critical values of equilibrium moisture content, corresponding to the a(w)=0.6, were 11.45% and 13.28%(wb) for water adsorption and desorption respectively, at the temperature of 20 degrees C. Heat of sorption (q(st)) was calculated using the chosen sorption model and Clausius-Clapeyron equation. An exponential function was found to fit the experimental q(st) values of amaranthus stems at moisture contents ranging from 7% to 40%(wb) for adsorption and desorption.

Tractor Pulling Tests Supported by Ecu Data Reading

Shrnutí Članek popisuje možnost využiti dat ze sběrnice CAN nebo ISO-BUS pro tahove zkoušky traktoru. Zkoušeni sestavalo z polnich a laboratornich zkoušek, před vlastnim polnim měřenim byl motor zkoušen na dynamometru. Parametry odečtene ze sběrnice CAN byly validovany externimi snimači a byla vyhodnocena jejich chyba. Na zakladě měřeni bylo shledano, že chyba prezentovaneho zatiženi odečteneho ze sběrnice CAN je velmi vyznamna. Pro zpřesněni teto hodnoty je nutne vytvořit regresni funkci. Model byl dale ověřen a byla vypočtena nejistota. Bylo shledano, že pro zahrnuti parametrů sběrnice CAN do testovacich procedur je nutne provest předchozi statistickou analyzu parametrů. Abstract The article describes the potential for using data from the CAN- or ISO- bus for tractor pulling tests. The testing techniques consisted of both field and laboratory tests; thus, each engine was tested in the laboratory before the field pulling tests. Values of CAN were validated by external instrumentation and their reliability with respect to the true values was analyzed. A significant degree of error was determined at low engine load; thus, for higher precision under the field conditions, it was necessary to use a regression function. The model was verified and its resulting uncertainty was calculated, which led to the conclusion that it is inadequate to take only the data from CAN into account if no further statistical processing is performed.