University of Maribor

About: University of Maribor is a education organization based out in Maribor, Slovenia. It is known for research contribution in the topics: Population & KEKB. The organization has 3987 authors who have published 13077 publications receiving 258339 citations. The organization is also known as: Univerza v Mariboru.

Immobilized lipase-mediated long-chain fatty acid esterification in dense carbon dioxide : bench-scale packed-bed reactor study

Abstract: Long-chain fatty acid esters are useful functional molecules responding to the requirements of numerous fields of application in cosmetic, pharmaceutical and lubricant industry. In the present work, lipase-catalysed production of n -octyl oleate by esterification of oleic acid with 1-octanol in dense CO 2 , as reaction medium, was performed in bench-scale packed-bed bioreactor, in order to obtain suitable reaction performance data for up-scaling. Lipase from Rhizomucor miehei (Lipozyme RM IM) was used as the biocatalyst. The experiments were planned to elucidate the effect of several process parameters, such as pressure, temperature, CO 2 and substrates flow rates. Pressure of 10 MPa, temperature of 323.15 K, CO 2 flow rate of 210 dm 3 /h and substrates flow rate of 18 cm 3 /h were predicted to be the optimum conditions: a maximum yield of about 93% was attained. Performing the enzymatic reaction in the continuously operating bioreactor, a long-term enzyme lifetime was observed and a decrease of the Lipozyme activity was not registered over 50 days. A comparison with experimental results obtained in batch-wise was also proposed. Operating at the optimum reaction conditions, higher ester yield than those obtained in batch-mode was detected. Supercritical carbon dioxide (SC-CO 2 ) showed to be a potential medium for the n -octyl oleate biosynthesis for a large-scale production in continuous-mode.

Diffusion and Localization in Chaotic Billiards.

Abstract: We study analytically and numerically the classical diffusive process which takes place in a chaotic billiard. This allows one to estimate the conditions under which the statistical properties of eigenvalues and eigenfunctions can be described by random matrix theory. In particular, the phenomenon of quantum dynamical localization should be observable in real experiments.