Deoxidation of a Copper Melt by CO Gas Bubbling to Produce Oxygen Free Copper

In this study, gas bubbling was used to deoxidise a copper melt. Prior to the deoxidation of copper, a water model was developed and evaluated to investigate the characteristics of bubbles produced by air injection with nozzles of different shapes and sizes. Bubble frequency, floating velocity and diameter were measured by a high speed video camera and were compared to theoretical results. Approximately 500 g of 99.9 % pure copper was melted in a graphite crucible by induction melting under an argon atmosphere. After samples were completely melted, CO gas was introduced from the nozzle into the copper melt to achieve deoxidisation. Oxygen concentrations in the melt were reduced to less than 6 ppm by CO gas bubbling. Electrical conductivities of the samples produced by CO bubbling were between 101.6 and 102.3 % IACS.     

Release of N-nitrosamines and N-nitrosatable substances from baby bottle teats and rubber kitchen tools in Korea

Food Science and Biotechnology - Ensuring the safety of baby bottle teats and kitchen tools made from rubber is critical. Therefore, the migration of N-nitrosamines and N-nitrosatable substances...     

Isolation and identification of pentagalloylglucose with broad-spectrum antibacterial activity from Rhus trichocarpa Miquel

Rhus trichocarpa Miquel has been utilised both as a food and for medicinal purposes. In this study, we determined that the methanol extracts of the stem and leaf portions of R. trichocarpa inhibited the growth of both Gram-negative and Gram-positive bacteria. The active constituent was isolated, and identified via mass spectrometry and NMR as 1,2,3,4,6-penta-O-galloyl-β-d-glucose. The compound also evidenced a broad spectrum of antibacterial activity against both Gram-negative and Gram-positive bacteria including Staphylococcus aureus (both methicillin-resistant S. aureus and quinolone-resistant S. aureus), Bacillus subtilis, Streptococcus mutans, Escherichia coli, Salmonella typhimurium, and Pseudomonas aeruginosa with MRC values of 16–32 μg/ml, whereas gallate failed to inhibit the growth of Gram-negative bacteria, even at a concentration of 128 μg/ml. The antibacterial activity of penta-O-galloylglucose was restored by the addition of Fe²⁺, whereas gallate was not, thereby indicating that its antibacterial activity could be attributable to the chelation of iron. The results of the time-kill study against S. aureus and E. coli revealed that penta-O-galloylglucose exhibited bacteriostatic activity. These findings indicate that the extracts of R. trichocarpa as well as its active component, penta-O-galloylglucose, may have profound potential for the control of both Gram-positive and negative pathogens.     

Copyrolysis of block polypropylene with waste wood chip

In this study, the copyrolysis of waste wood chip (WC) and block polypropylene (PP) was studied to investigate how the characteristics of bio-oils are affected by copyrolysis. The thermogravimetric analysis performed with a temperature rise of 20 °C/min, from room temperature to 600 °C, showed that the decomposition temperature of PP was a little higher via copyrolysis than the single-component pyrolysis. This result suggests that the characteristics of the pyrolysis of PP were affected by the pyrolysis products of WC. The Py-GC/MS analysis of the copyrolysis products detected some new compounds that had not been detected in the single-component pyrolysis products, indicating interactions between the products of WC and PP pyrolyses. The results of the experiments using a fixed bed reactor showed improved properties of the bio-oil obtained from the copyrolysis compared to those of the bio-oil obtained from the single-component pyrolysis: increased carbon and hydrogen contents, decreased water content and a significantly increased heating value.     

Down-Regulation of Hepatic Stearoyl-CoA Desaturase-1 Expression by Fucoxanthin via Leptin Signaling in Diabetic/Obese KK-A y Mice

Stearoyl-coenzyme A desaturase-1 (SCD1) is a rate-limiting enzyme that catalyzes the biosynthesis of monounsaturated fatty acids from saturated fatty acids. Recently, SCD1 down-regulation has been implicated in the prevention of obesity, and the improvement of insulin and leptin sensitivity. In this study, we examined the effect of fucoxanthin, a marine carotenoid, on hepatic SCD1 in obese mouse models of hyperleptinemia KK-A ^y and leptin-deficiency ob/ob. In KK-A ^y mice, providing a diet containing 0.2 % fucoxanthin for 2 weeks markedly suppressed SCD1 mRNA and protein expressions in the liver. The fatty acid composition of liver lipids was also affected by an observed decrease in the ratio of oleic acid to stearic acid. Furthermore, serum leptin levels were significantly decreased in hyperleptinemia KK-A ^y mice after 2 weeks of fucoxanthin feeding. However, the suppressive effects of fucoxanthin on hepatic SCD1 and body weight gain were not observed in ob/ob mice. These results show that fucoxanthin down-regulates SCD1 expression and alters fatty acid composition of the liver via regulation of leptin signaling in hyperleptinemia KK-A ^y mice but not in leptin-deficient ob/ob mice.     

Multi-human tracking using part-based appearance modelling and grouping-based tracklet association for visual surveillance applications

Multimedia Tools and Applications - Although much progress has been made in multi-object tracking in recent decades due to its variety of applications including visual surveillance, traffic...