The Optimization of Ethanol Production from Oil Palm Empty Fruit Bunches Hydrolysate by Using a Statistical Experimental Design

The oil palm empty fruit bunch (OPEFB) is one of the potential lignocellulosic biomasses for ethanol production. In this study, ethanol production from OPEFB was investigated. Firstly, OPEFB was alkali-pretreatment with 15% (w/v) NaOH at 121˚C for 45 min and it provided of 67.2% cellulose, 22.8% hemicellulose and 7.2% lignin. The cellulose content in the alkali-pretreated OPEFB had increased 39.4% from untreated OPEFB, while the hemicellulose and lignin had decreased to 33.1% and 36.7% respectively. Secondly, alkali-pretreated OPEFB was hydrolyzed with 7% (v/v) H2SO4 at 140°C for 90 min. The highest glucose yield of 92.38% was obtained representing 55.54 g/L. Lastly, the glucose resulting was fermented to ethanol by Saccharomyces cerevisiae. A response surface methodology (RSM) with a central composite design (CCD) was applied in the experimental design to optimize the ethanol production condition. Four independent variables via initial glucose (55-85 g/L), pH (4.75-6.25), temperature (25-35ºC) and inoculum size (2.0-4.0%) were evaluated. A verification experiment indicated the optimal fermentation condition was as follows: 55 g/L initial glucose, pH 6.25, 2% inoculum size at 35±2ºC for 48 h. The highest ethanol yield of 40.76% (22.4 g/L, 0.41 g/g glucose) was over 80% of the theoretical ethanol yield produced from glucose fermentation, which was 28.05 g/L (0.51 g/g glucose). The ethanol yield achieved appears quite attractive and demonstrates that OPEFB have excellent potential resource of renewable energy. While the experimental design is useful for optimization designs with several variables and describing more complex behavior by including higher orders model components

Study of Parameters Affecting Temperature of Journal Bearing and Shaft in Sugar Mill

In the sugar mill machine, equipment is operated under high temperature. This high temperature will affect to the roller shaft and journal bearing. Additionally, the equipment damages could be caused by the various factors that affected directly to roller shaft and journal bearing. In this research, the operations of equipments were modelled using the finite element analysis program (FEA), to determine the maximum temperature of the roller shaft and journal bearing after a specified period of time. An experiment with the physical roller shaft and journal bearing was carried out to obtain the actual temperature readings. Verification of the simulated results was performed by comparing the simulated values with the actual values obtained in the experiment. According to this research, the monitored parameters affected temperature and damages of the shaft and bearings during pressing oil from the hydraulic top cap. Finally, this research applied the FEA in conjunction with engineering and environmental management in sugar factory to reduces machine damange and to save energy during sugar mill operation

Eucalyptus-Mediated Synthesized Silver Nanoparticles-Coated Urinary Catheter Inhibits Microbial Migration and Biofilm Formation

Catheter-associated urinary tract infections (CAUTIs) are significant complications among catheterized patients, resulting in increased morbidity, mortality rates, and healthcare costs. Foley urinary catheters coated with synthesized silver nanoparticles (AgNPs) using Eucalyptus camaldulensis leaf extract were developed using a green chemistry principle. In situ-deposited AgNPs with particle size ranging between 20 and 120 nm on the catheter surface were illustrated by scanning electron microscopy. Atomic force microscopy revealed the changes in surface roughness after coating with nanoparticles. The coated catheter could significantly inhibit microbial adhesion and biofilm formation performed in pooled human urine-supplemented media to mimic a microenvironment during infections (p 0.05). AgNPs-coated catheter exhibited broad-spectrum antimicrobial activity against important pathogens, causing CAUTIs with no cytotoxic effects on HeLa cells. A reduction in microbial viability in biofilms was observed under confocal laser scanning microscopy. A catheter bridge model demonstrated complete prevention of Proteus mirabilis migration by the coated catheter. Significant inhibition of ascending motility of Escherichia coli and P. mirabilis along the AgNPs-coated catheter was demonstrated in an in vitro bladder model (p 0.05). The results suggested that the AgNPs-coated urinary catheter could be applied as an alternative strategy to minimize the risk of CAUTIs by preventing bacterial colonization and biofilm formation