Papers by Author: Di Geng

Abstract: In this study, we report one-pot biological fabrication of gold nanoparticles by a facile procedure using lixivium of Syzygium samarangense leaf without extra surfactant, capping agent, and/or template. The resulting gold nanoparticles showed good performance in the catalytic reduction of 4-nitrophenol.

Abstract: An anaerobic solid state fermentation (ASSF) of porcine blood by two ferment agents was investigated. The free amino acids (FAA) content was applied as reference indicator, response surface design of Box-Behnken (BBD) was used to select the optimum conditions of ASSF of porcine blood. The optimum conditions were determined as porcine blood moisture of 76.0%, fermentation time of 7d, fermentation temperature of 39.0±0.5 oC, addition of the components of the mixture as follows: wheat bran 10.8 g , corn flour 1.2 g, Active 99 ferment agent I 0.768 g, Active 99 ferment agent II 0.19 g, porcine blood 86.0 g, resulting in FAA content of 23.8 mg/g. Evaluation experiments revealed that FAA content of 22.9 mg/g, which was 96.2% of the predicted value using Eq.2, and achieved a 14-fold increase comparing with the 1.5 mg/g which is the FAA content of unfermented mixture. It was confirmed that the protein of porcine blood was degraded into small peptides by Sodium dodecyl sulfate - polyacrylamide gel electrophoresis (SDS-PAGE).

Abstract: The evaporation rate of histidine-water system was measured and the influence of pressure, temperature, His concentration, pH value of solution and the existence of NH4Cl salt was investigated. The results showed that operating pressure and temperature have significant influence on evaporation rate. Increasing vacuum and temperature could increase the rate. In contrast, the rate value was insensitive to the change of concentration of His, solution pH value and the existence of NH4Cl salt at the operating pressure and temperature. In connection with the operating conditions, properties of the research system and evaporation vessel geometry factors, a new mass transfer coefficient model, based on the dimensional analysis of experimental data, was proposed with relative error of ±10%. Check results showed that agreement between model predictions and experimental data is quite reasonable. The results obtained appear to be used to predict evaporation rate of histidine-water system for industrial reference.