Etán-etilén kolonna vizsgálata és optimalizálása

Az etán-etilén szétválasztás a vegyipari benzin feldolgozása során az egyik jelentős feladat. A szeparációhoz nagy mennyiségű hideg és meleg energia szükséges, ezért az energiafelhasználás csökkentésének lehetősége manapság is aktívan kutatott terület. Jelen cikk témája egy adott tányérszámú etán-etilén kolonna vizsgálata folyamat szimulációs szoftverrel. A vizsgálatnak két fő célja van, adott mennyiségű betáp mellett a maximális fejtermék biztosítása és a folyamat lefutásához szükséges energiamennyiség minimalizálása. A rendszer energiaszükséglete meghatározható a kiforraló, a kondenzátor és a betáp hőáramának összegével

In vitro and in vivo studies on biocompatibility of carbon fibres

In the present study we focused on the in vitro and in vivo evaluation of two types of carbon fibres (CFs): hydroxyapatite modified carbon fibres and porous carbon fibres. Porous CFs used as scaffold for tissues regeneration could simultaneously serve as a support for drug delivery or biologically active agents which would stimulate the tissue growth; while addition of nanohydroxyapatite to CFs precursor can modify their biological properties (such as bioactivity) without subsequent surface modifications, making the process cost and time effective. Presented results indicated that fibre modification with HAp promoted formation of apatite on the fibre surface during incubation in simulated body fluid. The materials biocompatibility was determined by culturing human osteoblast-like cells of the line MG 63 in contact with both types of CFs. Both tested materials gave good support to adhesion and growth of bone-derived cells. Materials were implanted into the skeletal rat muscle and a comparative analysis of tissue reaction to the presence of the two types of CFs was done. Activities of marker metabolic enzymes: cytochrome c oxidase (CCO) and acid phosphatase were examined to estimate the effect of implants on the metabolic state of surrounding tissues. Presented results evidence the biocompatibility of porous CFs and activity that stimulates the growth of connective tissues. In case of CFs modified with hydroxyapatite the time of inflammatory reaction was shorter than in case of traditional CFs

End-to-end annealing of plant microtubules by the p86 subunit of eukaryotic initiation factor-(iso)4F.

The p86 subunit of eukaryotic initiation factor-(iso)4F from wheat germ exhibits saturable and substoichiometric binding to maize microtubules, induces microtubule bundling in vitro, and is colocalized or closely associated with cortical microtubule bundles in maize root cells, indicating its function as a microtubule-associated protein (MAP). The effects of p86 on the growth of short, taxol-stabilized maize microtubules were investigated. Pure microtubules underwent a gradual length redistribution, an increase in mean length, and a decrease in number concentration consistent with an end-to-end annealing mechanism of microtubule growth. Saturating p86 enhanced the microtubule length distribution and produced significantly longer and fewer microtubules than the control, indicating a facilitation of annealing by p86. Confirmation of endwise annealing rather than of dynamic instability as the mechanism for microtubule growth was made using mammalian MAP2, which also promoted the redistribution of length, increase in mean length, and decrease in number concentration of taxol-stabilized maize microtubules. Enhancement of microtubule growth occurred concomitant with bundling by p86, indicating that an alignment of microtubules in bundles facilitated endwise annealing kinetics. The results demonstrate that nonfacile plant microtubules can spontaneously elongate by endwise annealing and that MAPs enhance the rate of annealing. The p86 subunit of eukaryotic initiation factor-(iso)4F may be an important regulator of microtubule dynamics in plant cells