Jiří Bouček

Dr. Jiří Bouček

ČZU

Research Focus & Metrics

Academic Career Length

7Years (2020-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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15 February 2021 in Materials
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Journal Article
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MOMichal Obergruber
Michal Obergruber
VHVladimír Hönig
Vladimír Hönig
PPPetr Prochazka
Petr Prochazka
VKViera Kučerová
Viera Kučerová
MKMartin Kotek
Martin Kotek
JMJakub Mařík
Jakub Mařík
Biobutanol is a renewable, less polluting, and potentially viable alternative fuel to conventional gasoline. Biobutanol can be produced from same sources as bioethanol, and it has many advantages over the widespread bioethanol. This paper systematically analyzes biobutanol fuel as an alternative to bioethanol in alcohol–gasoline mixtures and the physicochemical properties. Based on the conducted analyses, it was found that biobutanol mixtures have a more suitable behavior of vapor pressure without the occurrence of azeotrope, do not form a separate phase in lower temperature, it has higher energy density, but slightly reduce the octane number and a have higher viscosity. However, in general, biobutanol has many advantageous properties that could allow its use in gasoline engines instead of the commonly used bioethanol.

30 December 2022 in Forests
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Journal Article
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František KačíkFrantišek Kačík
František Kačík
IKIvan Kubovský
Ivan Kubovský
JBJiří Bouček
Jiří Bouček
Richard HrčkaRichard Hrčka
Richard Hrčka
MGMilan Gaff
Milan Gaff
DKDanica Kačíková
Danica Kačíková
Black locust is a fast-growing deciduous tree species with multiple industrial purposes due to its valuable traits. However, the heterogeneity of colour distribution between sapwood and heartwood limits its application. Thermal modification is an environment-friendly technology for improving various wood properties, especially dimensional stability, decay resistance, and colour homogeneity. In this work, black locust (Robinia pseudoacacia L.) wood samples were thermally modified at temperatures of 160, 180, and 210 °C. Extractives and main wood components were analysed by wet chemical methods, colour was measured by spectrometry, and structural changes by Fourier transform infrared spectroscopy. The obtained results show that the darkening of black locust wood, unlike other wood species of the temperate zone, is mainly caused by changes in extractives. Their content decreases during thermal treatment, but new chromophores are formed, especially in quinones. Degradation of hemicelluloses and the partial degradation of cellulose also contribute to colour changes. At higher temperatures, condensation reactions can occur in lignin, leading to the formation of some chromophores. Statistical analysis confirmed that temperature can be considered a very significant factor affecting the colour of the wood surface.

27 November 2020 in Materials
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Journal Article
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VHVladimír Hönig
Vladimír Hönig
PPPetr Prochazka
Petr Prochazka
MOMichal Obergruber
Michal Obergruber
VKViera Kučerová
Viera Kučerová
PMPavel Mejstřík
Pavel Mejstřík
JBJiří Bouček
Jiří Bouček
This article focuses on the issue of motor oils used in the engines of non-road mobile machinery (NRMM), more specifically tractors. The primary goal of the paper is to determine the appropriate replacement interval for these oils. The physical properties of the examined samples were first determined by conventional instruments. Furthermore, the concentrations of abrasive metals, contaminants, and additive elements were measured using an optical emission spectrometer. Lastly, the content of water, fuel, and glycol and the products of oxidation, nitration, and sulfation were determined by using infrared spectrometry. The measured values were compared to the limit values. Based on the processing and evaluation of these analyses, the overall condition of the oils was assessed and subsequently the optimal exchange interval of the examined oils was determined. In addition, a risk analysis of the outage was performed. Due to the high yields of crops, farmers can lose a significant amount of product when a tractor is not functioning during the harvest period. This loss is calculated in the paper.

30 June 2021 in Polymers
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Journal Article
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MGMilan Gaff
Milan Gaff
HČHana Čekovská
Hana Čekovská
JBJiří Bouček
Jiří Bouček
DKDanica Kačíková
Danica Kačíková
IKIvan Kubovský
Ivan Kubovský
František KačíkFrantišek Kačík
František Kačík
This paper deals with the effect of synthetic and natural flame retardants on flammability characteristics and chemical changes in thermally treated meranti wood (Shorea spp.). The basic chemical composition (extractives, lignin, holocellulose, cellulose, and hemicelluloses) was evaluated to clarify the relationships of temperature modifications (160 °C, 180 °C, and 210 °C) and incineration for 600 s. Weight loss, burning speed, the maximum burning rate, and the time to reach the maximum burning rate were evaluated. Relationships between flammable properties and chemical changes in thermally modified wood were evaluated with the Spearman correlation. The thermal modification did not confirm a positive contribution to the flammability and combustion properties of meranti wood. The effect of the synthetic retardant on all combustion properties was significantly higher compared to that of the natural retardant.

1 July 2021 in Materials
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Journal Article
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KHKaterina Hajkova
Katerina Hajkova
JBJiří Bouček
Jiří Bouček
PPPetr Prochazka
Petr Prochazka
PKPetr Kalous
Petr Kalous
DBDominik Budský
Dominik Budský
Because there is a lack of wood resources in many countries, this work focused on pulp and paper production from the waste and agricultural residues of non-wood plants. The work aimed to pulp the nitrate-alkaline of black mustard (Brassica Nigra L.) and camelina (Camelina Sativa L.). The black mustard and the camelina were selected due to the expanding planted areas of these crops in the Czech Republic. To characterize the chemical composition of black mustard and camelina, cellulose, lignin, ash, and extractives were determined. Raw alpha-cellulose, beta-cellulose, and gamma-cellulose were also measured. The results showed that the content of lignin in non-wood plants is lower than that in softwoods. The cooked pulp was characterized by the delignification degree–Kappa number. Additionally, handsheet papers were made for selected samples of pulp. The handsheet papers were characterized by tensile index, breaking length, and smoothness and compared with commonly available papers.

19 May 2021 in Forests
Verified
Journal Article
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PPPetr Prochazka
Petr Prochazka
VHVladimír Hönig
Vladimír Hönig
JBJiří Bouček
Jiří Bouček
KHKaterina Hajkova
Katerina Hajkova
Lukas TrakalLukas Trakal
Lukas Trakal
Hynek RoubíkHynek Roubík
Hynek Roubík
Due to high levels of volatility in both the agricultural and the forestry commodity markets, specifically, of timber and agricultural crops, it is important to identify the risks associated with the stability of supplies necessary for the production of composite materials in the Czech Republic. This study aims to accurately estimate the availability of selected raw materials that contain lignocellulose over the next 20 years. In addition, their suitability for the production of composite materials is assessed based on their physical properties. Furthermore, in the event of scarcity involving timber in the European Union, recycled wood and post-harvest residues could replace conventional raw materials in wood-based composites such as particleboards and chipboards. The viable potential of Czech forests is predicted to be between 740 and 750 million cubic meters of timber. For agricultural crops, it is estimated at 0.9 million hectares of wheat and 0.5 million hectares of canola under the current EU biofuel policy and at 0.4 million hectares if this policy is removed. According to moisture and fibre analyses carried out in our study, the most suitable candidate for wood-based composites production is soft wood.