• Korean Journal of Food Science and Technology
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• v.36 no.1
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• pp.162-167
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• 2004

In this study, untreated (UT), water soaking (WT), and sanitizing solutions [chlorine at 100 ppm (CL): ethanol at 10% (ET); hydrogen peroxide at 1% (HP); chlorine at 100 ppm + ethanol at 10%(CE); chlorine at 100 ppm + hydrogen peroxide at 1% (CH); ethanol at 10% + hydrogen peroxide at 1% (EH); chlorine at 100 ppm + ethanol at 10% + hydrogen peroxide at 1% (CEH)] were compared in terms of their antimicrobial effectiveness against natural microflora of wild cabbage (Brassica oleracea var. capitata). All samples were kept in sanitizing solutions for 2 min, and effectiveness of sanitizing agents was evaluated based on number of decimal reduction of total aerobic mesophilic, total coliforms, E. coli, lactic acid bacteria, and yeast and mold counts. Average initial levels of these organisms in samples were $9.21{\pm}0.15,\;6.60{\pm}0.06,\;6.08{\pm}0.03,\;and\;3.66{\pm}0.08\;log_{10}\;CFU/g$ for total aerobic mesophilic bacteria, total coliforms, lactic acid bacteria, and yeasts and molds, respectively, Escherichia coli was not detected in any tested samples. Decimal reduction of populations of total aerobic mesophilic, total coliforms, E. coli, lactic acid bacteria, and yeasts and molds were: in $WT\;8.09,\;5.36,\;5.82,\;and\;3.57 log_{10}\;CFU/g;\;in \;CL\;7.39,\;4.10\;5.24,\;2.45\;log_{10}\;CFU/g;\;in\;ET\;6.78,\;4.23,\;5.20,\;2.50\;log_{10}\;CFU/g;\;in\;HP\;6.11,\;4.27,\;5.28,\;2.46\;log_{10}\;CFU/g;\;in\;CE\;6.18,\;4.26,\;5.31,\;2.49\;log_{10}\;CFU/g;\;in\;CH\;6.10,\;3.77,\;5.33,\;2.46\;log_{10}\;CFU/g;\;in\;EH\;6.07\;3.82,\;4.76,\;2.41\;log_{10}\;CFU/g;\;and\;in\;CEH\;5.27,\;3.45,\;4.45,\;2.15\;log_{10}\;CFU/g,$ respectively. Statistical analysis of the results showed effectiveness of CEH sanitizing solution for elimination of microbial contamination was the highest among all sanitizer treatments.

• Applied Chemistry for Engineering
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• v.9 no.2
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• pp.207-213
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• 1998

On the basis of the previous study[1], miscibility were investigated and intermolecular interaction strength for the miscibility were relatively compared for the blends poly{2,2-(m-phenylene)-5,5'-bibenzimidazole}(PBI) with two aromatic polyimides (PIs) synthesized by another dianhydride. Aromatic PAAs were prepared by the reaction of condensation of two diamines, 4,4'-methylene dianiline(4,4'-MDA) and 4,4'-oxydianiline(4,4'-ODA) with 3,3',4,4'-diphenylsulfone tetracarboxylic dianhydride(DSDA) using DMAc, and then converted into PIs after curing. PBI/PAA blends were prepared by solution blending. Cast films or precipitated powders of the PBI/PAA blends were cared at a high temperature to transform into PBI/PIs blends. Miscibility and specific intermolecular interaction for miscibility in the blends were investigated, and compared with previous polyimide structures of PBI/PIs blends [1]. Two blends, PBI/DSDA+4,4'-MDA(Blend-V) and PBI/DSDA+4,4'-ODA(Blend-VI), were found miscible : the evidences were optically clear films, synergistic single composition dependent $T_g{\prime}s$, and frequency shifts of N-H stretching band as much as $39{\sim}40cm^{-1}$, and of C=O stretching band near 1730 and $1780cm^{-1}$, 5~6 and $3{\sim}4cm^{-1}$, respectively. The specific intermolecular interactions existing between PBI and PIs were relatively analyzed with the area(A) formed between the $T_g{\prime}s$ of the measured and that of the calculated by the Fox equation at all compositions, the ${\kappa}$ values in Gordon-Taylor equation obtained from the measured $T_g{\prime}s$, and differences of the frequency shifts in the functional N-H and carbonyl stretching band. From the results, the area(A) and the ${\kappa}$ values for Blend-V and VI were smaller than those for Blend-III and IV used in previous study[1]. Differences of the frequency shifts in the functional groups(N-H and C=O) also showed similar tendency. Thus, specific intermolecular interaction strength in terms of hydrogen bonding of PBI/PI blends is dependent upon chemical structures of PIs, that is, PIs it seems that $SO_2$ group in dianhydride(DSDA) has weaker hydrogen bond strength than those of C=O in BTDA. In other words, it implies that the former occupied bulk space than the latter due to the sterric effect.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.12
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• pp.1337-1346
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• 2006

Soil humin is the insoluble fraction of humic materials and play an important roles in the irreversible sorption of hydrophobic organic contaminants onto soil particles. However, there have been limited knowledge about the sorption and chemical properties of humin due to the difficulties in its separation from the inorganic matrix(mainly clays and oxides). In this study, de-ashed soil humins($Hu_1-Hu_6$) were isolated from a soil residues(Crude Hu) after removing alkali-soluble organic fractions followed by consecutive dissolution of the mineral matrix with 2%-HF for 2 hr. The humin samples were characterized by elemental analysis and $^{13}C$ NMR spectroscopic method and their sorption-desorption behavior for 1-naphthol were investigated from aqueous solution. The results were compared one another and that with peat humin. $^{13}C$ NMR spectra features indicate that the soil humin molecules are mainly made up of aliphatic carbons(>80% in total carbon) including carbohydrate, methylene chain. Freundlich sorption parameter, n was increased from 0.538 to 0.697 and organic carbon-normalized sorption coefficient(log $K_{OC}$) values also increased from 2.43 to 2.74 as inorganic matrix of the soil humin removed by HF de-ashing. The results suggest that inorganic phase in humin plays an important, indirect role in 1-naphthol sorption and the effects on the sorption non-linearity and intensity are analyzed by comparison between the results of soil humin and peat humin. Sorption-desorption hysteresis were also observed in all the humin samples and hysteresis index(HI) at low solute concentration($C_e$=0.1 mg/L) are in order of Peat humin(2.67)>De-ashed humin(0.74)>Crude Hu(0.59).

• The Korean Journal of Pesticide Science
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• v.6 no.2
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• pp.96-104
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• 2002

This study was carried out to investigate cytotoxicity of paraquat on NIH 3T3 fibroblasts, toxicity of paraquat and compensatory effects of 3-methylcholanthrene (3-MC) on the rat lung. In order to conduct MIT [3-(4,5-Dimethylthiazol-2-yl) -2,5-diphenyl -2H-tetrazolium-bromide] and NR (Neutral red) assay, the $5.0{\times}10^4cell/ml$ of NIH 3T3 fibroblast in each well of 24 multi-dish were cultured. After 24 hours, the cells were treated with solution of paraquat (1, 25, 50 and $100{\mu}M$ respectively). After the NIH 3T3 fibroblast of all groups were cultured in same condition for 48 hours. MIT and NR assay were performed to evaluate the cytotoxicity of cell organelles. $MTT_{50}\;and\;NR_{50}$ of paraquat were $1668.97{\mu}M\;and\;1030.85{\mu}M$, respectively. These $IC_{50}$ of Paraquat were decided as a low cytotoxicity by Borenfreund and Puemer (1984). In order to observe the toxicity and compensatory effects of paraquat on the rat lung, Spraque Dawley male rats were used as experimental animals and were divided into paraquat only treated group and simultaneous application group of paraquat and 3-MC, at 30 min and 1, 3, 6, 12, 24, 48 and 96 hrs interval after each treatment. The animals were sacrificed by decapitation and their or the lungs were immediately removed, immersed in fixatives, and were processed with routine method for light microscopic study. Paraffin sections were stained with H&E and iron hematoxylin of Verhoeff. Under the light microscopy, erythrocytes were full in alveolar capillaries at 3 hrs and congested at 24 hrs after paraquat administration. The great alveolar cells (Type II cell) were increased and mitosis of great alveolar were observed in interalveolar septa. Many lymphocytes, macrophages and polymorphonuclear (PMN) cells were observed in connective tissue surrounding lung tissue and germinal center in lymph follicles of terminal bronchiole. Alveolar macrophages were increased in interalveolar septa and alveoli at 48 hrs. And observed many alveolar macrophages at 96 hrs. In iron hematoxylin stain of Verhoeff, Collagen fiber were increased in respiratory bronchiole, interalveolar septa and alveoli and breath of alveoli, and alveolar pore were broaden. But, in paraquat plus 3-MC treated group, morphological changes were mild in lung tissue. These results indicate that 3-MC has a compensatory effects against toxicity of paraquat by conjugation with oxygen.

• Journal of radiological science and technology
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• v.26 no.2
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• pp.57-61
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• 2003

The purpose of this study is to compare both 1.5T and 4.7T in Praietal White matter material Phantom using the same methodology at both field strengths. Data at both field strengths are compared in terms of $T_2$ relaxation times, line widths and SNRs MR imaging and $^1H$ MR spectroscopy were performed on GE 1.5T SIGNA system and Broker Biospec 4.7T/30 MRI/MRS system. After phantom axial scan $^1H$ MRS was obtained from T2 weighted image by 3-dimensional localization technique(PRESS : Point RE solved spectroscopy Sequence) this phantom is composed of an aqueous solution 36.7 mmol/L of NAA, 25.0 mmol/L of Cr, 6.3 mmol/L of choline chloride, 30.0 mmol/L or Glu, and 22.5 mmol/L of MI(adjusted to a pH of 7,15 in a phosphate buffet). Data processed using software developed inhouse. At 1.5T, T2 relaxation times for Cho, Cr, and NAA were $0.41{\pm}0.07,\;0.26{\pm}0.04,\;0.46{\pm}0.07$ while at 4.7T they were $0.17{\pm}0.03,\;0.14{\pm}0.05,\;0.20{\pm}0.03$ respectively. At 1.5T, line widths for water, Cho, Cr and NAA were $2.9{\pm}0.7,\;1.6{\pm}0.7,\;1.7{\pm}0.8,\;2.2{\pm}0.02Hz$ while at 4.7T they were $5.2{\pm}1.1,\;4.6{\pm}1.9,\;4.01{\pm}1.8,\;4.8{\pm}1.9Hz$ respectively. It can be seen that $T_2$ relaxation times were significantly shorter at 4.7 compared to 1.5T and that the line widths were also broader. The average SNRs for NAA for subjects at short and long TEs were $23.5{\pm}11.3$ at TE=20 msec ; $15.4{\pm}7.7$ at TE=272 msec at 1.5T and $40{\pm}8.3$ and $17{\pm}3.5$ respectively at 4.7T higher field strength is superior because of improved sensitivity and chemical shift dispersion. However these improvements are partially offset by increased line widths and decrease $T_2$ relaxation times, which act to reduce both sensitivity and resolution. In our experiments with the equipment available to us, 4.7T proton spectra at short TEs exhibit moderately improved sensitivity compared to 1.5T.

• Journal of the Korean Wood Science and Technology
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• v.46 no.1
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• pp.17-28
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• 2018

In this study, catalytic activation using sulfuric acid lignin (SAL), the condensed solid by-product from saccharification process, with potassium hydroxide at $750^{\circ}C$ for 1 h in order to investigate its potential to nanoporous carbon In this study, catalytic activation using sulfuric acid lignin (SAL), the condensed solid by-product from saccharification process, with potassium hydroxide at $750^{\circ}C$ for 1 h in order to investigate its potential to nanoporous carbon material. Comparison study was also conducted by production of activated carbon from coconut shell (CCNS), Pinus, and Avicel, and each activated carbon was characterized by chemical composition, Raman spectroscopy, SEM analysis, and BET analysis. The amount of solid residue after thermogravimetric analysis of biomass samples at the final temperature of $750^{\circ}C$ was SAL > CCNS > Pinus > Avicel, which was the same as the order of activated carbon yields after catalytic activation. Specifically, SAL-derived activated carbon showed the highest value of carbon content (91.0%) and $I_d/I_g$ peak ratio (4.2), indicating that amorphous large aromatic structure layer was formed with high carbon fixation. In addition, the largest changes was observed in SAL with the maximum BET specific surface area and pore volume of $2341m^2/g$ and $1.270cm^3/g$, respectively. Furthermore, the adsorption test for three kinds of organic pollutants (phenol, 2,4-Dichlorophenoxyacetic acid, and carbofuran) were conducted, and an excellent adsorption capacity more than 90 mg/g for all activated carbon was determined using 100 ppm of the standard solution. Therefore, SAL, a condensed structure, can be used not only as a nanoporous carbon material with high specific surface area but also as a biosorbent applied to a carbon filter for remediation of organic pollutants in future.

• Korean journal of applied entomology
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• v.16 no.2 s.31
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• pp.127-131
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• 1977

This experiment was conducted to evaluate the insect-proof netting, chemical sprays, application of attractants, fruit bagging and light trapping as the control methods of the fruit piercing moths in the orchards on reclaimed land in Sugyeri, Goksung, Chonnam Province, during June to October in 1976. The results are summarized as follows; 1. Insect-proof. netting effectively decreased fruit damage, compared as to the control, down to $9.4\%$ from $38.3\%$ in plum, $2.5\%$ from $53.0\%$ in peaches and $10.0\%$ from $29.0\%$ in grapes. 2. The control effects of chemicals varied significantly among the 7 insecticides tested: Deoclean, Naphthalene, and Thiometon were more effective to the fruit damages as low as $2.0\%,\; 3.6\%,\;and\;5.9\%$ respectively. while the fruit damage was rather high, $9.8\%$ for Demeton, $10.1\%$, for Takju +lead arsenate and $14.2\%$ for Padan. ,3. In the test with 7 attractants, the largest number of moths attracted and killed was 416.by Takju+brown sugar and the next was 307 by Takju+venegor while this number was 141 by mixed solution (see text) which is rather lower than expectation The fruit damage was lowest in Takju+honey and$5.2\%$, the next was $5.60\%$ for Takju+venegor and the highest was $12.0\%$, Takju alone. 4. Fruit bagging with polyethylene film effectively decreased the fruit damage from the inserts but brought about severe fruit rot and delay ripening. Meanwhile, paper bagging was less effective in preventing insects, resulting in $17.5\%$ fruit damage, however, gave no adverse effect other than slight Belay in ripening. 5. Light trapping was hardly expected to be a method of controlling these fruit piercing moths. However, the number of collected moths swarmed by electric light was 10.8 for can-descence, 0.95 for blue, and 0.22 for yellow light.

• Journal of Korean Society of Forest Science
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• v.76 no.3
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• pp.230-240
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• 1987

Half-sib seedlings of Ginkgo biloba (one-year-old) were treated with various simulated acid rains(pH2.0, pH3.0, pH4.0 and pH5.0) to examine the effects of acid rain on leaf surface area, leaf injury, leaf chlorophyll content and photosynthetic ability of the leaf tissue. The seedlings were grown in a pot($4500cm^3$) containing one of three different soils(nurseryy soil, mixed soil and sandy soil). Simulated acid rain was made by diluting sulfuric and nitric acid solution($H_2SO_4:HNO_3=3:1$, V/V) with tap water and tap water(pH6.4), and treated by 5mm each time for three minutes during the growing seasons(April to October 1985). Acid rain treatments were done three times per week to potted seedlings by spraying the solutions. The results obtained in this study were as follows : 1. Leaf surface area per seedling at pH2.0 level was the lowest among the levels of pH, but those at other pH levels were not significantly different. 2. Leaf injury(injured leaf rate and injured leaf area) increased with decreasing pH levels of acid rain. 3. Leaf chlorophyll content measured during the period June through October was significantly different among the soil types, and that of the seedling in nursery soil was the highest. The lower pH levels of simulated acid rain was treated ; more leaf chlorophyll content was measured at the beginning of treatment, and the more it severely decreased at the late growing period. 4. Photosyntetic abilities, and the highest value was shown in nursery soil. Significand difference in photosynthetic ability among the levels of pH was observed only in August. Photosynthetic ability increased with decreasing pH levels at the beginning of treatment, but decreased rapidly after July.

• KSBB Journal
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• v.24 no.1
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• pp.1-8
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• 2009

In the past decade, we have observed rapid advances in the development of biochips in many fields including medical and environmental monitoring. Biochip experiments involve immobilizing a ligand on a solid substrate surface, and monitoring its interaction with an analyte in a sample solution. Metal nanoparticles can display extinction bands on their surfaces. These charge density oscillations are simply known as the localized surface plasmon resonance (LSPR). The high sensitivity of LSPR has been utilized to design biochips for the label-free detection of biomolecular interactions with various ligands. LSPR-based optical biochips and biosensors are easy to fabricate, and the apparatus cost for the evaluation of optical characteristics is lower than that for the conventional surface plasmon resonance apparatus. Furthermore, the operation procedure has become more convenient as it does not require labeling procedure. In this paper, we review the recent advances in LSPR research and also describe the LSPR-based optical biosensor constructed with a core-shell dielectric nanoparticle biochip for its application to label-free biomolecular detections such as antigen-antibody interaction.

• Journal of the korean academy of Pediatric Dentistry
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• v.34 no.2
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• pp.273-284
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• 2007

The aim of this study was to evaluate the resistance to degradation and to compare the wear resistance characteristics of four esthetic restorative materials in an alkaline solution(0.1N NaOH). The composite resins studied were Composan LCM flow(Promedica, Germany). Clearfil ST(Kuraray medical, Japan), Durafi VS1(Heraeus Kulzer, U.S.A), Point 4(Kerr, U.S.A). The results were as follows : 1. The mass loss of each brand was $1.02{\sim}6.04%$ and highest value in Durafil VS$(6.04{\pm}0.29%)$. 2. The sequence of the degree of degradation layer depth was in descending order by Durafil VS, Clearfil ST, Point 4 and Composan LCM flow. There were significant differences between Point 4, Composan LCM flow and the others (p<0.001). 3. The sequence of the Si loss was in descending order by Clearfil ST, Durafil VS, Composan LCM flow and Point 4. There were significant differences among the materials (p<0.001). 4. On SEM, destruction of bonding between matrix and filler and on CLSM, the depth of degradation layer of specimen surface was observed. 5. The sequence of maximum wear depth was in descending order by Durafil VS, Composan LCM flow, Point 4 and Clearfil ST. There were no significant differences among the materials (p>0.001) 6. The correlation coefficient between Si loss and degradation layer depth (r=0.892, p<0.01) and Si loss and mass loss(r=0.736, p<0.01) were relatively high. These results indicate that hydrolytic degradation, wear and another factor may consider as evaluation factors of composite resins.