Roman Stryjek

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Biodiesel (a mixture of fatty acid esters) is normally analyzed using gas chromatography/flame ionization detection, as specified by the ASTM D6584 and EN14105 standards. This paper proposes a binary gradient method for analyzing biodiesel mixtures using non-aqueous reverse phase HPLC with a UV detector capable of overcoming the drawbacks of the gas(More)
The selection of the optimal commercial oil to be used as lubricant in a refrigerating system with carbon dioxide (CO2) as working fluid is not solved yet, though POE and PAG oils give acceptable results. Only a real knowledge of the oil structure and thermodynamic behavior of the oil+refrigerant mixture allows a proper selection of the lubricant. Then, a(More)
A better knowledge of the transport and thermodynamic properties for the refrigerant+lubricant system is required to properly design the refrigeration circuit. This is essential also to develop proper models able to predict the behavior of the mixture refrigerant+lubricant depending on the working conditions. However, the experimental data available in(More)
The blends formed mixing hydrofluorocarbons (HFC) and hydrocarbons (HC) can be classified as semi-natural refrigerants since, by optimizing the composition, it is in principle possible to adapt basic features such as GWP, TEWI and flammability to the industrial and environmental requirements. However, the energetic efficiency must be competitive with the(More)
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