21 research outputs found
Electronic control unit for spark-ignition gas engines
Diplomová práce se zabývá návrhem a sestavením elektronické řídící jednotky pro motor AVIA D 407NG. Bylo navrženo hardwarové i softwarové vybavení pro řízení výstupů (elektromagnetický ventil plynu, škrtící klapka směčovače, ěoupš odměrného průřezu plynu, signál předstihu) na základě vyhodnocení vstupních dat ze snímačů (otáčky, teplota chladící kapaliny, signál lambda sondy, ...). Řídící jednotka využívá dva mikroprocesory firmy ATMEL (RISC procesor AT90S8515 a AT89C2051). Data z jednotky je možné monitorovat a měnit v kontrolním PC po jeho připojení přes sériovou linku RS 232C
Chemical Composition and Antimicrobial Activity of Cinnamon, Thyme, Oregano and Clove Essential Oils Against Plant Pathogenic Bacteria
Essential oils are volatile substances from plants and many of them have antimicrobial activity. For that reason, they have become known as a useful alternative to chemical preservatives and pesticides. In this study, we tested essential oils of four aromatic plants. Cinnamon (Cinnamomum zeylanicum), thyme (Thymus vulgaris), oregano (Origanum vulgare) and clove (Syzygium aromaticum) essential oils were investigated for their composition and antimicrobial effect against plant pathogenic bacteria (Pectobacterium spp. and Pseudomonas spp.). Both are commonly associated with diseased fruit trees in orchards and gardens. The chemical composition of the tested essential oils was identified by gas chromatography coupled with mass spectrometry. The cinnamon essential oil was most effective form tested oil. The experimental results indicated that the wild strains of tested bacteria are more resistant to essential oils than commonly used laboratory strains. In conclusion, certain essential oils could be used for the control of postharvest bacterial pathogens. The findings of the present study suggest that the essential oils have a potential to be used as antimicrobial agents
CFD simulation of the multiphase heat transfer during the quenching process
PING 2019 is organized with the support of funds for specific university research project SVK1-2019-002.The paper presents the results of the CFD simulation of quenching process for the ring
shape sample. The aim of the work is to develop and validate the methodology for
multiphase CFD simulation including the boiling during the quenching process. CFD
simulation is provided in ANSYS Fluent. The Lee model is used for modelling the
phase change during the quenching process. The first step consider the simulation of
cooling of the ring sample when the correct model parameters will be found. Validation
of results is performed by comparison with experimental data. Experimental was
realized inside the own designed quenching bath device filled with quenching polymer.
The general description of the experimental setup is included in the paper. The CFD
results are cooling curves, i.e. variation of solid temperature on time. The Lee model
parameters especially the evaporation frequency was tuned. Thin polymer film on the
solid surface was considered to bring the results closer to the experimental data. The
comparison between experiment and CFD shows very good agreement for higher
temperatures, which covers the boiling stage. On the other hand for lower temperatures
worse match of results was found caused probably by the sensitivity on the inlet
velocity profile settings. Some recommendations for future work were defined
Technická zpráva č. ISRN TUL - VCT/C - MŘTP/TZ - - 03/004/CZ č. ISRN TUL - VCT/C - MŘTP/TZ - - 03/003/CZ
Ve zprávě jsou uvedeny charakteristické vlastnosti měřícího zařízení pro přesná dynamická měření úhlových rychlostí a úhlů. Jsou prezentovány důvody, které vedly k vývoji nové generace tohoto zařízení a popsány důležité úpravy a rozšíření proti stávajícímu přístroji. V závěru je shrnut současný stav vývoje a realizace zařízení a nastíněn další postup prací
Technická zpráva č. ISRN TUL - VCT/C - MŘTP/TZ - - 03/004/CZ č. ISRN TUL - VCT/C - MŘTP/TZ - - 03/003/CZ
Zpráva se zabývá laboratorními zkouškami a provozním ověřováním přenosného měřícího zařízení Wawet (Warp and Weft Tension meter) a úpravami měřícího a vyhodnocovacího software
Insecticidal activity of two formulations of essential oils against the cereal leaf beetle
Purpose: Plant-derived essential oils and their encapsulations have recently received increasing interest as an alternative to synthetic biopesticides suitable for integrated pest management and organic farming. In this study, combinations of essential oils (EO) from Rosmarinus officinalis with Cymbopogon citratus and Pelargonium graveolens with Thymus vulgaris in two formulations including encapsulate were tested for their potential for wheat protection against adults and larvae of Oulema melanopus (L.). Materials and methods: The chemical composition of the essential oils was analyzed by gas chromatography-mass spectrometry (GC-MS). Testing of insecticidal activity of the evaluated substances was conducted with 2.5 ml of tested combinations of EOs sprayed on the paper. Ten adults or larvae of O. melanopus were placed into a vessel. Control of mortality of O. melanopus specimens was assessed after 24 h after establishment of the experiment. Results and conclusions: Tarsal contact toxicity assay showed the effectiveness of EO in concentration against O. melanopus larvae and adults in both formulations (essential oil and encapsulation) causing 100% mortality within 24 h. These results indicate the great potential of these essential oils and their encapsulations for future use in crop protection against insect pests