• Korean Journal of Materials Research
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• v.16 no.6
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• pp.367-372
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• 2006

Polytetrafluoroethylene (PTFE) surface was modified for improving hydrophilicity by ion irradiation in environmental gas of $N_2$ and $NH_3$, respectively. The water contact angle onto the PTFE surface increased from $104{\circ}$ to over $140{\circ}$ by Ar ion irradiation in $N_2$ gas. In the case of $NH_3$ as environmental gas, there were a slight increase of contact angle from ion dose of $1{\times}10^{15}\;to\;5{\times}10^{15}\;ions/cm^2$, and its dramatic decrease to the value of 35o at the conditions of ion dose higher than $1{\times}10^{16}\;ions/cm^2$. It was found from SEM results that the surface morphology of PTFE was changed into one with filament structure after Ar ion irradiation in $N_2$ gas environments. On the contrary, Ar ion irradiation in $NH_3$ gas condition induced the PTFE surface with network structure. Hydrogen ion irradiation resulted in a little change of PTFE surface morphology, comparing with the case of Ar ion irradiation. The water contact angle of hydrogen ion irradiated PTFE surface in reactive gas decreased with increment of ion dose. Hydrogen ion irradiation could improve hydrophilicity with little change of surface morphology. It might be considered from FT-IR results that the improvement in wettability of PTFE surface by ion irradiation in $N_2$ and $NH_3$ gases could be due to the hydrophilic groups of NHx bonds.

• Food Science and Preservation
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• v.17 no.4
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• pp.547-554
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• 2010

We developed watermelon (Citrullus vulgaris Schrad) wine to increase the market for the fruit, which is currently sold only in fresh form. The pH of watermelon wine was pH 2.8~3.4, the total acid level 0.48~0.55%, and the soluble solid $5{\sim}6^{\circ}brix$ alcohol content was 9.5~10.5%. Fermentation of watermelon juice was satisfactory at both 20C and 25C. All of citric acid, malic acid, and oxalic acid were detected in watermelon wine citric acid was the most abundant. All of glucose, fructose, sucrose, and maltose were present in juice, and both fructose and glucose were used in fermentation. Electron-donating ability (EDA) was high, being 80% of the control value when watermelon wine was diluted to $400\;{\mu}l/ml$. SOD-like activities were present in both watermelon juice and wine, being 55.2% and 49.2% of control values, respectively. Nitrite-scavenging ability (NSA) was 70.2% and 53.2% of control values in undiluted juice and wine, respectively. Watermelon juice showed higher activation than did wine, but functionality neither fell nor rose after fermentation. In sensory evaluation of wine, the overall score was better than average, at 4.15, thus establishing the commercial potential of watermelon wine.

• Journal of Nutrition and Health
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• v.23 no.2
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• pp.135-147
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• 1990

This study was devised to observe the cytotoxic activities of garlic extracts against various cancer cells, that is, murine leukemic lymphocyte(L1210 and P388) and human rectal(HRT-18) and colon cancer cells(HCT-48 and HT-29) in vitro, and murine ascitic tumor cell(S-180) in vivo. Each cell-line except S-180 was cultured in medium containing serial concentration of the garlic extract in vitro. Inhibitory effect n the growth rate of the cancer cells was stronger in extracts of petroleum ether than that of ethanol. A lipid soluble compound in the extracts of garlic was cytocidal to murine leukemic cells, human rectal and colon cancer cells in vitro. The growth rates of the cancer cells in medium containing garlic extracts were inhibited gradually to a significant degree in proportion to the increase of the extract concentration. The cytotoxic activity of garlic active fraction from TLC was about 2.3 times more potent than that of crude garlic extract, one unit of cytotoxic activity against L1210 cells being equivalent to 4.2$\mu\textrm{g}$ and 1.8$\mu\textrm{g}$ from the crude garlic and active fraction, respectively. The Rf value of the active fraction on silica-gel TLC was 0.18 in condition that petroleum ether/ethyl ether/acetic acid mixture(90:10:1, v/v/v) was used as a developing solvent. The survival times of mice inoculated with S-180 cells were extended about 1.5 to 2 times in the groups treated with garlic extract(through i.p. and oral administration) compared with their control group(no garlic extract treatment). Observations were carried out on S-180. Ethanol extracts of garlic injured markedly tumor cells within 3 hours after injection.

• BMB Reports
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• v.28 no.2
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• pp.149-154
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• 1995

Protein methylase II (S-adenosyl-L-methionine : protein O-methyl-transferase, EC 2.1.1.24; PM II) was purified approximately 1250-fold from porcine testis by fractional precipitation and DEAE-cellulose chromatography, followed by gel filtration on a Sephadex G-75 column and HPLC on a Protein Pak 125 column. The molecular weight of the enzyme was estimated to be 33,000 daltons by SDS-PAGE, which agreed with the value determined by gel filtration. Isoelectric focusing of purified PM II showed a single protein species with an isoelectric point of 6.2. The optimum pH for the reaction was 6.0. The $K_m$ value of the enzyme was $1{\times}10^{-5}M$ with a $V_{max}$ value of 769 pmol/min/mg of enzyme. S-adenosyl-L-homocysteine is a competitive inhibitor of PM II with a $K_i$ value of $1.38{\times}10^{-6}M$.

• Microbiology and Biotechnology Letters
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• v.41 no.3
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• pp.327-334
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• 2013

For the development of hardy kiwi wine, we arranged for the post-maturity of hardy kiwi fruit, treated them with calcium carbonate and a pectinase enzyme complex, investigated the resulting physicochemical properties and conducted a sensory evaluation. The period determined for creating post-maturity in the hardy kiwi fruit was determined as 5 days storage at room temperature following maturity. During this time the yield of fruit juice was increased from 22.1% to 53.5% using 0.1% (v/v) cytolase PCL5 for 2 h at room temperature. 0.1% (w/v) calcium carbonate was also added during the process of aging, for the reduction of the sour taste. The fermentation trial of the hardy kiwi wine was prepared using water (25% or 50%), sugar ($24^{\circ}brix$), 0.1% (w/v) $CaCO_3$, 0.1% (v/v) cytolase PCL5, $K_2S_2O_5$ (200 ppm), and yeast ($1.5{\times}10^7$ cell/ml). Fermentation then occurred for 2 weeks at $20^{\circ}C$. The pH value, total acidity, alcohol, and reducing sugar content of the resulting hardy kiwi wines of 25% (v/w) and 50% (v/w) water, were in a range of pH 3.4-3.7, 1.12-1.21%, 14.3-14.4%, and 15-16 g/l, respectively. Citric acid and fructose constituted the major organic acids and the free sugar of the 25% and 50% hardy kiwi wine, respectively. Volatile flavor components, including 10 kinds of esters, 8 kinds of alcohols, 5 kinds of acids, 3 kinds of others and aldehydes, were determined by GC analysis. The results of sensory evaluation demonstrated that 50% hardy kiwi wine is more palatable than 25% hardy kiwi wine.

• Science of Emotion and Sensibility
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• v.16 no.1
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• pp.53-64
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• 2013

Folksonomies have potential problems caused by synonyms, tagging level, neologisms and so forth when retrieving music by tags. These problems can be tackled by introducing the mood intensity (Arousal and Valence value) of music as its internal tag. That is, if moods of music pieces and their mood tags are all represented internally by numeric values, A (Arousal) value and V (Valence) value, and they are retrieved by these values, then music pieces having similar mood with the mood tag of a query can be retrieved based on the similarity of their AV values though their tags are not exactly matched with the query. As a prerequisite study, in this paper, we propose the mapping table defining the relation between AV values and folksonomy tags. For analysis of the association between AV values and tags, ANOVA tests are performed on the test data collected from the well known music retrieval site last.fm. The results show that the P values for A values and V values are 0.0, which means the null hypotheses could be rejected and the alternative hypotheses could be adopted. Consequently, it is verified that the distribution of AV values depends on folksonomy tags.

• Journal of the Korean Society of Radiology
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• v.16 no.6
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• pp.673-680
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• 2022

In this study, based on PLA, we analyzed the Hounsfield Unit (HU) of materials containing 20% each of aluminum, wood, copper, carbon, and marble, and tried to analyze how they affect the image. A cylindrical phantom of 5×30×30 ㎣ (thickness×diameter×height) was fabricated using a entry-level 3D printer. The kV was changed to 80, 100 and 120, and the mAs was changed to 100 and 200 mAs, and the phantom in the center of the table was cross-scanned under a total of six conditions. A circular ROI was set using image J program and the quantification value of the material part HU and the quantification value of the peripheral part CNR were obtained. The HU average of the material part increased in the order of [PLA - wood 20%], [PLA - marble 20%], [PLA - carbon 20%], [PLA 100%], [PLA - aluminum 20%], [PLA - copper 20%] (p<0.05) a negative correlation was confirmed with the HU by increasing kV. It was confirmed that the CNR value in the peripheral area increased in the order of [PLA - marble 20%], [PLA - copper 20%], [PLA - carbon 20%], [PLA - wood 20%], [PLA - aluminum 20%], and [PLA - 100%] (p<0.05). Human organs with similar HU values for each material are [PLA - copper 20%] compact bone, [PLA - aluminum 20%] cancellous bone, [PLA 100%] coagulated blood, [PLA - carbon 20%] and [PLA - marble 20%] liver, muscle, spleen and [PLA - wood 20%] had similar values to fat. In addition, we confirmed the blur phenomenon that blurs the image around the filament with all materials, and confirmed that [PLA 100%] especially has the most blur around the filament. Therefore, it is considered desirable to reflect the HU value of the target organ and consider cloudiness around the phantom when selecting materials for medical phantom fabrication, and this research can provide basic data.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.58 no.4
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• pp.538-540
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• 2009

The SBN thin films were deposited at substrate temperature of 300[$^{\circ}C$] on Pt-coated electrode (Pt/Ti/$SiO_2$/Si(100)) using RF sputtering method. The grain and crystallinity of SBN thin films were increased with the increase of annealing temperature. The dielectric constant(150) of SBN thin film was obtained by annealing temperature above 750[$^{\circ}C$]. The voltage dependence of dielectric loss showed a value within 0.01 in voltage ranges of -5~+5[V]. The capacitance characteristics showed a stable value of about 0.7[${\mu}F/cm^2$].

• Structural Engineering and Mechanics
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• v.75 no.6
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• pp.723-736
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• 2020

In this paper, acoustic emission (AE) and pattern recognition are utilized to identify the AE signal signatures caused by propagation of stress corrosion cracking (SCC) in a 304 stainless steel plate. The surface of the plate is under almost uniform tensile stress at a notch. A corrosive environment is provided by exposing the notch to a solution of 1% Potassium Tetrathionate by weight. The Global b-value indicated an occurrence of the first visible crack and damage stages during the SCC. Furthermore, a method based on linear regression has been developed for damage identification using AE data.

• Korean Membrane Journal
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• v.11 no.1
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• pp.15-20
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• 2009

The periodic water-back-flushing using permeate water was performed to minimize membrane fouling and to enhance permeate flux in tubular ceramic ultrafiltration (UF) system for Gongji stream water treatment in Chuncheon city. The filtration time (FT), which was the water-back-flushing period, 2 min with periodic 15 sec water-back-flushing showed the highest value of dimensionless permeate flux ($J/J_o$), and the lowest value of resistance of membrane fouling ($R_f$), and we acquired the highest total permeate volume ($V_T$) of 6.35 L. Consequently FT 2 min at back-flushing time (BT) 15 sec could be the optimal condition in advanced UF water treatment of Gongji stream. Then the average rejection rates of pollutants by our tubular ceramic UF system were 99.4% for Turbidity, 31.8% for $COD_{Mn}$, 22.6% for $NH_3$-N and 65.9% for T-P.