Tag Archives: viscosity.

1293-1299 T. Jehlička and J. Sander
Modification of the rheological properties of the honey in the honeycombs prior to its extraction in the production conditions
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Modification of the rheological properties of the honey in the honeycombs prior to its extraction in the production conditions

T. Jehlička¹* and J. Sander²

¹Czech University of Life Sciences Prague, Faculty of Engineering, Department of Technological Equipment of Buildings, Kamýcká 129, CZ 165 21 Prague 6 – Suchdol, Czech Republic
²Czech University of Life Sciences Prague, Faculty of Engineering, Department of Technological Equipment of Buildings, Kamýcká 129, CZ 165 21 Prague 6 – Suchdol, Czech Republic
*Correspondence: jehlickat@tf.czu.cz

Abstract:

This paper addresses the issue of honey extraction in difficult conditions (prevailing cold weather) and the extraction of highly viscous honey from the honeycombs. The objective was to design and validate a technology that will reduce the viscosity of honey in the honeycombs by warming up by infrared radiation and shorten the total time of honey extraction. To verify the proposed procedure three groups of samples of the capped honeycombs were selected that contained honey of different botanical origin and rheological properties. The honeycombs were warmed up to the targeted temperature (from 15 °C to 40 °C). Warming was carried out by two low-temperature emitters of the infrared radiation. The time dependence of honey extraction on the temperature of the pre-heated honeycombs was monitored. The measured values indicate that the dependence of the rheological properties of honey on temperature is technologically significant. Operational monitoring shown that the optimal rheological properties for the processing of the honeycombs are at a temperature above 30 °C as the time necessary for the honeycombs extraction reaches its minimum value. The optimal temperature for the honeycomb extraction can be considered the temperature above 30 °C which corresponds to the extraction time for about 4 minutes. The evaluation of the obtained results demonstrates the operational reliability of the proposed technology. Measurements proved that the infrared radiation is suitable for warming up of the honeycombs, warming up is quick and results in time reduction of honey extraction from honeycombs is dependent on temperature.

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1227-1233 V. Hönig, L. Smrčka, R. Ilves and A. Küüt
Adding biobutanol to diesel fuel and impact on fuel blend parametres
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Adding biobutanol to diesel fuel and impact on fuel blend parametres

V. Hönig¹*, L. Smrčka², R. Ilves³ and A. Küüt³

¹Czech University of Life Sciences Prague, Faculty of Agrobiology, Food and Natural Resources, Department of Chemistry, Kamýcka 129, 16521 Prague 6, Czech Republic
²University of Economics, Faculty of Business Administration, Department of Strategy, W. Churchill Sq., 13067 Prague 3, Czech Republic
³Estonian University of Life Sciences, Institute of Technology, Kreutzwaldi 56, EE51014 Tartu, Estonia
*Correspondence: honig@af.czu.cz

Abstract:

One of the main arguments for the use of biofuels is environmental reason. Biofuels release significantly lower quantities of greenhouse gases (GHG) during the combustion opposed to conventional fossil fuels. Fatty acid methyl esters are commercially blended with diesel and bioethanol with gasoline. Biobutanol and bioethanol are using the same sources. Biobutanol can be used as a biofuel in internal combustion engines in the same manner as bioethanol. Application of biobutanol in diesel is rather marginal, but is definitely preferable in diesel engines in comparison with bioethanol. There are plenty of options to use biobutanol in diesel engines. The simplest are blends with diesel. Number of parameters can used to compare biobutanol with standard diesel. Fuel parameters are changing with the amount of butanol added. Maximum amount of butanol in diesel in order to prevent negative effects was assessed.

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425-430 K. Veselá, M. Pexa and J. Mařík
The effect of biofuels on the quality and purity of engine oil
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The effect of biofuels on the quality and purity of engine oil

K. Veselá*, M. Pexa and J. Mařík

Faculty of Engineering, CULS-Czech University of Life Sciences Prague, Kamycka 129, 16521, Prague 6, Czech Republic; *Correspondence: kvesela@tf.czu.cz

Abstract:

The European Union aims to promote the use of biofuels and thus set a commitment to the expansion of biofuels in transport. Biofuels replace fossil fuels mainly in part, the creation of biodiesel. For gasoline engines, the most widely used biofuel is E85, a fuel containing 85% ethanol and 15% gasoline. The more bio-components are contained in a fuel, the more oil filling the combustion engine suffers. Therefore, in this paper, a comparison of the properties of oil filling when using fossil fuels (currently contains a small amount of the fuel ethanol) and the E85 biofuel is provided. The cars Saab 95 and 93 are monitored, namely the motors B235 R, B207 L, and B205 L. For each car, the total of 10 samples of engine oil were taken. One part of the samples was collected during operation of the internal combustion engine on the biofuel E85 and the second during operation of the internal combustion engine on the fossil fuel BA95. Both vehicles used the same engine oil, Mobil 1 0W-40, for lubrication of the internal combustion engine. The analyses of the engine oil are focused on the evaluation of the kinematic viscosity and density at 40 and 100°C.

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427-432 K. Laos , E. Kirs , R. Pall and K. Martverk
The Crystallization Behaviour of Estonian Honeys
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The Crystallization Behaviour of Estonian Honeys

K. Laos¹ ², E. Kirs¹ ², R. Pall¹ and K. Martverk¹

¹Department of Food Processing, Tallinn University of Technology, Ehitajate tee 5, EE12086 Tallinn, Estonia; e-mails: katrin.laos@ttu.ee; evelinkirs@gmail.com; praili@hotmail.com; kaie.martverk@ttu.ee
²Competence Center of Food and Fermentation Technologies, Akadeemia tee 15B, EE12618 Tallinn, Estonia

Abstract:

The feasibility of water activity and viscosity measurement was studied to characterize the isothermal crystallization of Estonian honeys. In parallel, samples were observed by light microscopy. The most important phenomenon for crystallization is the fructose/glucose ratio in favour of glucose. The increase in water activity and viscosity was noticed during crystallization. Polarized light microscopy was more sensitive than water activity or viscosity for determining the crystallization time.

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