ABSTRACT
Sugar compounds present in chopped solid-sweet sorghum particles were fermented to ethanol in a rotarydrum fermentor (RDF) using an ethanol tolerant yeast strain. The influence of rotational speed of the RDF on the rate of ethanol fermentation was investigated and compared with static flask experiments. The rate of ethanol formation decreased with increasing rotational speed. The maximum rate and extent of ethanol formation were ca. 3.1 g EtOH/L h (based on expressed juice volume) and ca. 9.6 g EtOH/100 g mash, respectively, at 1 rpm rotational speed.
ABSTRACT
Solid-state fermentation of chopped sweet sorghum particles to ethanol was studied in static flasks using an ethanol tolerant yeast strain. The influence of various process parameters, such as temperature, yeast cell concentration, and moisture content, on the rate and extent of ethanol fermentation was investigated. Optimal values of these parameters were found to be 35 degrees C, 7 x 10(8) cells/g raw sorghum, and 70% moisture level, respectively.
ABSTRACT
A new type of segmented polyurethane (SPU) was synthesized from alpha, omega polyethylene oxide diols (PEG) of MW varying from 600 to 4500, by end capping with 1,4 trans cyclohexane diisocyanate (CHDI) and chain extending with ethylene diamine (ED) in toluene with dibutyl tin dilaurate as catalyst. These SPU are cast as films and coatings from hexafluroisopropanol (HFIP). Depending on PEG MW, these SPU swell two- to tenfold in water. Examined by an in vitro platelet retention test, these SPU are more bland (platelet retention -rho around 0.05) than most other polymers, whereas an alternating copolymer of CHDI and ED shows -rho around 0.80 (very active); x-ray photoelectron spectroscopy shows that the surfaces of these SPU to a depth of about 40 Ao are nearly pure PEO, unlike SPU synthesized from aromatic diisocyanates TDI and MDI.
