• Proceedings of the Korean Vacuum Society Conference
• /
• 2011.02a
• /
• pp.407-408
• /
• 2011

Natural boron consists of two stable isotopes 10B and 11B with natural abundance of 18.8 atom percent of 10B and 81.2 atom percent of 11B. The thermal neutron absorption cross-section for 10B and 11B are 3837 barn and 0.005 barn respectively. 10B enriched specific compounds are used for control rods and as a reactor coolant additives. In this work 2 methods for boron enrichment were analysed: 1) Gas irradiation in static conditions. Dissociation occurs due to multiphoton absorption by specific isotopes in appropriately tuned laser field. IR shifted laser pulses are usually used in combination with increasing the laser intensity also improves selectivity up to some degree. In order to prevent recombination of dissociated molecules BCl3 is mixed with H2S 2) SILARC method. Advantages of this method: a) Gas cooling is helpful to split and shrink boron isotopes absorption bands. In order to achieve better selectivity BCl3 gas has to be substantially rarefied (~0.01%-5%) in mixture with carrier gas. b) Laser intensity is lower than in the first method. Some preliminary calculations of dissociation and recombination with carrier gas molecules energetics for both methods will be demonstrated Boron separation in SILARC method can be represented as multistage process: 1) Mixture of BCl3 with carrier gas is putted in reservoir 2) Gas overcooling due to expansion through Laval nozzle 3) IR multiphoton absorption by gas irradiated by specifically tuned laser field with subsequent gradual gas condensation in outlet chamber It is planned to develop software which includes these stages. This software will rely on the following available software based on quantum molecular dynamics in external quantized field: 1) WavePacket: Each particle is treated semiclassicaly based on Wigner transform method 2) Turbomole: It is based on local density methods like density of functional methods (DFT) and its improvement- coupled clusters approach (CC) to take into account quantum correlation. These models will be used to extract information concerning kinetic coefficients, and their dependence on applied external field. Information on radiative corrections to equation of state induced by laser field which take into account possible phase transition (or crossover?) can be also revealed. This mixed phase equation of state with quantum corrections will be further used in hydrodynamical simulations. Moreover results of these hydrodynamical simulations can be compared with results of CFD calculations. The first reasonable question to ask before starting the CFD simulations is whether turbulent effects are significant or not, and how to model turbulence? The questions of laser beam parameters and outlet chamber geometry which are most optimal to make all gas volume irradiated is also discussed. Relationship between enrichment factor and stagnation pressure and temperature based on experimental data is also reported.

• Journal of Conservation Science
• /
• v.32 no.1
• /
• pp.21-32
• /
• 2016

Animal glue is a traditional material used extensively as adhesive and binder in mother-of-pearl, wooden structure, traditional painting, etc. Analysis of animal glue is usually performed with IR(infrared spectroscopy) based on the IR absorption of functional group. But, it has a limitation in confirming animal glue when a sample consists of several materials because of overlapping of the absorption band. Py/GC/MS(pyrolysis/gas chromatography/mass spectrometry) is a useful tool in analyzing the constituent of polymeric materials like animal glue by identifying their pyrolysate with very small amount of sample. In this study, confirmation of animal glue in a Dancheong sample was tried with this method. Characteristic pyrolytic compounds of animal glue and tung oil used in Dancheong were identified. Dancheong sample painted with Noerok as a coloring material, animal glue and tung oil was prepared and it was possible to find characteristic peaks of animal glue after thermal degradation and artificial weathering experiment. From this, we found that animal glue can be detected using py/GC/MS in cultural heritage samples consisting of several materials and in different condition. IR was also tried to analyze Dancheong sample and the results were compared with those of py/GC/MS for the detection of animal glue.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.53 no.2
• /
• pp.233-238
• /
• 2008

This experiment was conducted to enhance the colored potatoes utilization and to determine the biological activity of colored potato extracts. In order to understand the factors responsible for the potent anti-oxidant ability of colored potatoes, it has been evaluated for anti-oxidative activity using oxygen radical absorbance capacity (ORAC) assay. 'Hongyoung' extract was significant anti-oxidant activities in ORAC assay. About two-fold higher radical absorbance capacity was found in 'Hongyoung' compared to that in 'Jayoung'. The ability of 80% ethanol extracts from colored potatoes to influence the inhibitory activity of nitric oxide (NO) and nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2) has also been investigated. The various therapeutic benefit claims in the new functional medicinal usage of colored potatoes ascribed to the phenolic compounds and anthocyanin. This result revealed that the extracts of colored potatoes are expected to be good candidate for development into sources of free radical scavenger or COX-2 inhibiting agents.

• Korean Journal of Food Science and Technology
• /
• v.49 no.5
• /
• pp.474-479
• /
• 2017

Five types of coffee bean, which are usually imported and consumed in Korea, were roasted at $250^{\circ}C$ for 15 min and extracted by using a filter coffee machine. The physicochemical properties, functional components, and radical scavenging activity of coffee bean extracts were investigated. The pH of extract was the highest among the extracts and the soluble solid contents of extracts were $0.9-1.0^{\circ}Bx$. The acidity of the extracts was in the range from 0.46-0.55%, which was not significantly different from the control. Indonesian coffee bean extract showed the highest brown color intensity and contained the highest amounts of caffeine and chlorogenic acid. The highest total polyphenol content was found in Kenyan coffee bean extract. Coffee bean extracts from Indonesia and Kenya showed significantly higher radical scavenging activities than the other extracts. This study showed that coffee bean extracts from Indonesia and Kenya contained a large number of bioactive compounds and high antioxidant activity.

• Horticultural Science & Technology
• /
• v.30 no.4
• /
• pp.409-416
• /
• 2012

The amount of cellular components including soluble sugars, amino acids, organic acids and glucosinolates (GLS) was investigated during radish root processing to develop a radish beverage. The radish root was divided into two parts, white and green tissue, and processed separately by extracting the juice from the fresh tissue and from the boiled tissue to compare differences in the components content among the preparations. The overall palatability of both the fresh and boiled extracts from the green part of the radish was higher than that of the same extracts from the white part. The sweetness of extract by boiling increased and its pungency decreased, thereby the palatability increased by being compared to the fresh radish extract. The sweetness was affected by sucrose not by glucose or fructose of monosaccharides by showing different sucrose contents according to treatment comparing palatability. Malic acid was identified as primary organic acid, and the content was higher in both the fresh and boiled extracts from the white part than in the extracts from the green part of the radish. The fresh extract from the green part of the radish contained more essential amino acids, such as threonine and valine, and more hydrophilic amino acids including glutamic acid, aspartic acid, and arginine than those of the fresh extract from the white part, suggesting the green fresh part is more palatable than the white fresh part. The main sulfur compound was ethylthiocyanate in radish, and others were butyl isothiocyanate, dimethyl-disulfide, and 4-methylthio-3-butylisothiocyanate. The four GLS were detected much more in the fresh green and fresh white parts of the radish because they evaporated during boiling. The contents of the four sulfur compounds were higher in the white fresh part than in the green fresh part, which is likely the reason the pungency was higher and the palatability was lower in the white fresh part than in the green fresh part of the radish. The ascorbic acid content was higher in the fresh extract compared to the boiled extracts from both the green and white parts. Taken together, these findings indicate that fresh radish extract is superior to obtain in terms of retaining desirable nutritional and functional components for health.

• Applied Chemistry for Engineering
• /
• v.24 no.6
• /
• pp.605-610
• /
• 2013

Gamma-aminobutyric acid (GABA) is a non-protein amino acid widely present in organisms, which has shown several important physiological functions such as neurotransmission, hypotension induction, as well as diuretic and tranquilizer effects. They have also been extensively used in food industry. GABA contents in the grain and brown rice are about 1~4 mg/100 g and 4~8 mg/100 g, respectively but it is difficult to expect physiological activity from such low amounts of natural food intake. We investigate the effects of GABA-coated rice on the secretion of melatonin and serotonin which both have been used as sleep inductive compounds. As a result, the secretion of melatonin and serotonin from mice were found to be $3.578{\pm}0.158pg/mL$, $5.918{\pm}0.169ng/mL$ respectively. The melatonin and serotonin in mice increased significantly up to the 8.7 and 22.8 times respectively, when compared to that of the rice, but there was no cumulative effects. Due to the continuous intake of GABA-coated rice, which was developed as a functional food nutrient, inductive effects of melatonin and serotonin from general rice could be achieved and also the similar effect as taking up directly 25 mg/mL of GABA could be obtained.

• Journal of Life Science
• /
• v.20 no.1
• /
• pp.82-89
• /
• 2010

This study was investigated to analyze the contents of flavonoid compounds and the effects of fermentation on the physiological activities of medical plants, also known as SanYa (SY). Antioxidative activity of the fermented SanYa (FSY) was measured by using DPPH radical scavenging and SOD-like activity. DPPH radical scavenging and SOD-like activity of FSY were 94.3% and 45.0%, respectively. Nitric oxide (NO) synthesis was increased 11 times through the addition of FSY. However, NO production of the macrophages RAW264.7 cells stimulated with lipopolysaccharide (LPS) was reduced to 56% through the addition of FSY. FSY showed fibrinolytic activity and indicated about 69.8% and 73.7% of xanthine oxidase and angiotensin converting enzyme inhibitory activities, respectively. These results suggested that FSY plays a significant role in fibrinolytic activity and have strong xanthine oxidase and angiotensin converting enzyme inhibitory activities.

• Journal of Life Science
• /
• v.27 no.2
• /
• pp.172-179
• /
• 2017

The fermentation of Panax ginseng can yield many compounds from ginsenosides that have a wide variety of biological functions. Lactic acid bacteria (LAB) strains are capable of converting ginsenosides. The purposes of this study were to: (1) characterize Enterococcus faecium SA5, an isolated LAB from Mongolian mare milk, (2) identify the existence of extracellular ${\beta}$-glucosidase activity in the milk, and (3) ascertain if the ${\beta}$-glucosidase has the capacity of converting ginsenoside in Korean ginseng. The results revealed that E. faecium SA5 was acid-resistant, bile salt-resistant, and has antibiotic activities against 4 pathogenic microorganisms (Salmonella typhimurium KCTC 3216, Listeria monocytogenes KCTC 3710, Bacillus cereus KCTC 1012, Staphylococcus aureus KCTC 1621). In addition, E. faecium SA5 had tolerance against some antibiotics such as colistin, gentamycin and neomycin. It was also found that E. faecium SA5 possessed bile salt hydrolase activity, which could lower blood cholesterol level. When incubated in 10% (w/v) skim milk as a yogurt starter, E. faecium SA5 caused to decrease pH of the medium as well as increase in viable cell counts. Using TLC and HPLC analysis on the samples incubated in MRS broth, our study confirmed that E. faecium SA5 can produce ${\beta}$-glucosidase, which was capable of converting ginsenoside $Rb_1$ into new ginsenosides $Rg_3-s$ and $Rg_3-r$. It was concluded that E. faecium SA5 possessed a potential of probiotic activity, which could be applied to yogurt manufacture as well as ginsenoside conversion in ginseng.

• Journal of Life Science
• /
• v.28 no.5
• /
• pp.540-546
• /
• 2018

Annona muricata, generally known as soursop, graviola, or sirsak, is native to the warmest tropical areas of North and South America and is now widely distributed throughout tropical and subtropical parts of the world, including India and Nigeria. This study tested the contents of polyphenolic compounds, flavonoids, and minerals, as well as the antioxidative effects of DPPH radical-scavenging activity, Fe/Cu-reducing power, linoleic-acid peroxidation using thiobarbituric-acid (TBA) methods and peroxidation of rat-hepatocyte microsomes, and ${\beta}$-carotene bleaching assay. These were tested with in-vitro experimental models using water, ethanol, and methanol extracts of the Annona muricata leaf (AMl). Water extracts of AMl showed the highest extraction yield (1.76%). The total polyphenol-compound concentration was the highest in the methanol extract of AMl. However, the flavonoids concentration was the highest in the ethanol extracts of AMl. AMlMl major minerals were Ca, K, and Mg. In DPPH radical-scavenging activity, the contents exhibited a strong scavenging effect on the ethanol and methanol extracts of AMl. Additionally, the Fe/Cu-reducing power was strong in ethanol and methanol extracts of AMl. $Fe^{2+}$/ascorbate-induced linoleic-acid peroxidation using TBA methods and auto-oxidation of rat-hepatic microsomes showed strong antioxidative activities in ethanol extracts of AMl. ${\beta}$-Carotene bleaching was also highest in the ethanol extracts of AMl. These results may provide the basic data to understand the chemical characteristics and antioxidative effects of Annona muricata leaf extract for the development of functional foods.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.41 no.3
• /
• pp.269-277
• /
• 2015

Herbal plant extracts are good resources to find functional compounds for cosmetic ingredient. In this study, the extract of Areca semen (A. semen) was studied for melanogenesis inhibition and antioxidant activity. The results showed that ethyl acetate fraction of A. semen contained phenolic contents, $301.35{\pm}0.88{\mu}g/mg$, and exhibited potent antioxidant activity with $IC_{50}$ value of $1.02{\pm}0.07{\mu}g/mg$. Further, FRAP value exhibited potent antioxidant activity with $9.07{\pm}0.36mM$. Disk diffusion assay was performed for antibacterial activity. Ethyl acetate fraction of A. semen showed antibacterial activity against Staphylococcus aureus (S. aureus) and Staphylococcus epidermidis (S. epidermidis) at $80{\mu}g/mL$, whereas it showed no significant antibacterial activity against Escherichia coli (E. coli). The results of cell viability indicated that ethyl acetate fraction did not show cytotoxicity to B16/F1 cells at $80{\mu}g/mL$ and showed significant cytotoxicity at $100{\mu}g/mL$ of concentration and showed inhibition of melanin synthesis inhibitory, $29.78{\pm}0.31%$ at $80{\mu}g/mL$. Furthermore, mRNA expressions of tyrosinase and MITF were decreased after treatment with ethyl acetate fraction in a dose-dependent manner. As a result, the ethyl acetate fraction of A. semen could be considered as potential as whitening agents.