• Polymer(Korea)
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• v.27 no.5
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• pp.405-412
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• 2003

Poly(vinyl alcohol) (PVA) and N-(2-hydroxy)propyl-3-trimethylammonium chitosan chloride (HTCC), a water soluble chitosan derivative synthesized by the reaction of quaternary ammonium compound with chitosan, were blended using water as a solvent and the PVA/HTCC blend films with various compositions were prepared by solution casting method. The miscibility between the two polymers and the thermal properties of the blend films were investigated using FT-IR, DSC, DMA, and TGA. Single glass transition temperatures and single melting temperatures of the blend films along with the strong and clear film state for the whole composition of blending ratios suggest the miscibility between PVA and HTCC. The PVA/HTCC blend films with HTCC content of 1% and greater showed excellent antimicrobial activity.

• Analytical Science and Technology
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• v.8 no.4
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• pp.511-517
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• 1995

A cationic water soluble porphyrin (5,10,15,20-tetrakis (l-methyl-pyridinium-4-yl)porphyrin, $H_2tmpyp^{4+}$) and its metalloporphyrins (MP) were easily extracted into acetonitrile separated by addition of sodium chloride ($4mol\;dm^{-3}$) in the presence of sodium perchlorate, where M denotes $Zn^{2+}$, $Cu^{2+}$, $Co^{3+}$, $Fe^{3+}$, and $Mn^{3+}$ and $P^{2-}$ is porphyrinate ion. The extracted ion-pair complexes were completely dissociated to $[MP(ClO_4)_3]^+$, and $[MP(ClO_4)_2]^{2+}$. The extraction and the dissociation constants were determined by taking into account of the partition constant of sodium perchlorate ($K_D=1.82{\pm}0.01$). The chemical properties of the separated acetonitrile phase as $E_{T(30)}$ and $D_{II,I}$ were determined and compared with other water miscible solvents (acetone, actonitrile, 1,4-dioxane, tetrahydrofuran, 1-propanol and 2-propanol). Furthermore, a sensitive and selective method was proposed for the determination of a subnanogram amount of copper(II) in natural water samples by using the present salting-out method and the porphyrins.

• Structural Engineering and Mechanics
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• v.90 no.5
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• pp.493-504
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• 2024

This paper presents the methodology and results for the investigation of the structural safety of 40 aged underground water tanks to support the weight of photovoltaic (PV) systems that were supposed to be placed on their roof reinforced concrete (RC) slabs. The investigation procedure included (1) review of available documents; (2) visual inspection of the roof RC slabs; (3) carrying out a series of nondestructive (ND) tests; and (4) analysis of results. Out of the 40 tanks, eleven failed the visual inspection phase and were discarded from further investigation. The roof RC slabs of the tanks that passed the visual inspection were subjected to a series of ND tests that included infrared thermography, impact echo, ultrasonic pulse velocity (UPV), Schmidt hammer, concrete core compressive strength, and water-soluble chloride content. The NDT results proved that eight more tanks were not suitable to support the PV systems. Based on the results of the visual inspection and testing, a probabilistic decision-making criterion was established to reach a decision regarding the structural integrity of the roof slabs. The study concluded that the condition of the drainage filter was essential in protecting the tanks and its intact presence can be used as a strong indication of the structural integrity of the roof RC slabs.

• Journal of Physiology & Pathology in Korean Medicine
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• v.18 no.3
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• pp.754-758
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• 2004

To test the cytoprotective effect of sophorae radix (SR) against hydrogen peroxide (H₂O₂)-induced cytotoxicity, we investigated the cell viability using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay in the presence of methylene chloride, n-butanol, ethyl acetate and water soluble fraction of SR water extracts in H9c2 cells. These results were obtained as followed; H₂O₂ decreased the cell viability of H9c2 cells in a dose dependent manner. Cells pretreated with SR water extracts were protected the H₂O₂-induced decrease of viability in H9c2 cells. Among organic solvents fractions of SR water extracts, ethyl acetate soluble fractions of SR protected the decrease of viability induced by H₂O₂ in H9c2 cells. These results suggest that ethyl acetate soluble fractions of SR water extracts is effective in the prevention of H₂O₂-induced cytotoxicity.

• Journal of the East Asian Society of Dietary Life
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• v.11 no.4
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• pp.274-280
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• 2001

The chemical forms of calcium compounds in perilla leaves and their changes after harvest were investigated. The four types of calcium compounds extracted were as follows: water soluble calcium(F-I: mainly water soluble organic acid salts and calcium ion), IN-sodium chloride soluble calcium(F-II: calcium-pectate and calcium-carbonate), 2%-acetic acid soluble calcium(F-III: calcium-phosphate), and 5%-hydrochloric acid soluble calcium(F-IV: calcium-oxalate). The calcium content of perilla leaves was not found to vary with their age. Relatively high levels of F-l (28.4~39.5) and F-II (34.4~47.4) were found in young and mature leaves while the F-IV constituted 15.6~21.6% of the total calcium. The F-IV calcium contents of perilla. spinach and jaso were 16.8, 42.4 and 22.3%, respectively. In contrast to calcium. magnesium existed as water soluble magnesium at the highest content of 90.6% in spinach while 62.9% and 16.8% of the total magnesium existed as water soluble magnesium in perilla and jaso, repectively. The change in vitamin C and F-IV calcium content were examined for 7 days after harvest. Vitamin C content decreased slowly at the beginning but rapidly from the 4th day after harvest. On the other hand, the F-IV calcium content increased slowly at the beginning and rapidly from the 4th day of observation. This result suggests that the increase in F-IV calcium is related to the decrease in vitamin C content. This phenomena was more distinctly observed at 2$0^{\circ}C$ than 5$^{\circ}C$.

• Journal of the Korean Wood Science and Technology
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• v.34 no.2
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• pp.83-87
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• 2006

The leaves of Paulownia coreana Uyeki were extracted with acetone-$H_2O$ (7:3, v/v), concentrated under reduced pressure and fractionated successively with n-hexane, methylene chloride and ethyl acetate, leaving residual water soluble fraction. A portion of the resulting aqueous soluble powder was chromatographed on a Sephadex LH-20 column using aqueous methanol and ethanol-hexane as washing solvents. Three apigenin derivatives were isolated and identified as apigenin-7-O-${\beta}$-D-glucpyranoside, apigenin-7-O-${\beta}$-D-glucuronopyranoside and apigenin-7-O-[${\beta}$-D-glucuronopyranosyl($1{\rightarrow}2$)-O-${\beta}$-D-glucuronopyranoside] by spectroscopic methods including NMR and FAB-MS.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.11a
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• pp.241-244
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• 2004

The evaluation of Single or multi-degregation of concrete coated by high performance surface penetration agency was examined through various tests, i.e., carbonation, absorption, carbonation + chloride ion and carbonation + chemical solution according to various high performance surface penetration agencies and various compressive strengths of base concrete. The 2 types of high performance surface penetration agencies were used i.e., inorganic and alcohol soluble. And 2 types of compressive strength of base concrete were used such as 21 30. MPa. The characteristics of concrete coated high performance surface penetration agency was more improved than that of non-coated concrete, and especially, water soluble inorganic agency was most effective. And if compressive strength of base concrete was low, the improved effects would be larger.

• Journal of Korean Society of Environmental Engineers
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• v.39 no.7
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• pp.385-390
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• 2017

This study investigated removal characteristic of soluble Cs in water by RPT (Radioactivity pollutant treatment) with coagulation and sedimentation. The RPT conducted with various chemical and natural coagulants to remove the soluble Cs which consisted pre-adsorption, Sedimentation and post-adsorption. Natural absorbent included Illite and zeolite. Especially, Illite divided LPI (Large Particle Illite) and SPI (Small Particle Illite) by grain size. Also, Chemical coagulants included high basicity PAC (poly aluminum chloride). The adsorbent had a plate structure mainly composed of quartz, albite and muscovite. The surface area were $4.201m^2/g$ and $4.227m^2/g$ and the particle sizes were $197.4-840.9{\mu}m$ and $3.28-53.57{\mu}m$, respectively. The adsorption efficiency of the natural Illite was 82.8% for LPI and 85.6% for SPI. The removal efficiency of turbidity, which was an indirect indicator of adsorbent recovery, was 96.4% and 98.3%, respectively.

• Food Engineering Progress
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• v.13 no.4
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• pp.360-364
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• 2009

The onion extractions of MIX treatment (5% $\beta$ cyclodextrin+1% calcium chloride+1% soluble starch mixture solution) using hot water (100${^{\circ}C}$ and 80${^{\circ}C}$) and ultrasonic treatment (25${^{\circ}C}$) incresed L values and decreased a and b values apart from the extraction methods. Extent of the browning reaction as caused by the MIX treatment (0.093) following 100${^{\circ}C}$ water extraction resulted in as low as 31% O.D. level, as compared to the control(0.296). Analysis of the pyruvic acid showed that the control had higher content of pyruric acid than MIX-treated samples. The MIX treatment had lower intensities and higher preferences of browning color and pungency taste compared to the control. The total and coliform microbial counts increased continuously during storage period, while the MIX treatment reduced the number of viable cells. Finally, it was concluded that the MIX treatment was highly effective in suppressing the undesirable browning color and pungent taste after processing, and the microbes increment during storage.

• Journal of agriculture & life science
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• v.43 no.3
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• pp.15-26
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• 2009

This study was undertaken to determine inhibitory compounds from extracts of the softwood (larix leptolepis, Pseudotsuga menziesii) sawdust against Trichoderma spp. The sawdust of L. leptolepis and P. menziesii were hot water extracted, which were with fraction extracted organic solvents. The organic solvent extractions were carried out by n-hexane, methylene chloride, ethyl acetate. The antifungal activity of hot water extracts of L. leptolepis sawdust was determined to be 20.6% inhibition at a concentration of 1,000 ppm against Trichoderma spp. The antifungal activity of P. menziesii sawdust was outstanding about 60.3% against Trichoderma spp. The yields of the fractions of n-hexane soluble, methylene chloride soluble and ethyl acetate soluble from the hot water extract of L. leptolepis sawdust were 4.0%, 6.0% and 8.0%, repectively. However, the yields of the fractions of three solvents of P. menziesii sawdust were 8.0%, 13.0 and 14.0% correspondingly. The antifungal activity of n-hexane soluble fraction from hot water extracts of L. leptolepis sawdust was highest to about 68.5% to 79.9% against Trichoderma spp. compared to others. The antifungal activities of n-hexane soluble fraction from hot water extracts of P. menziesii sawdust showed 68.5%, 71.4%. 71.9%, 75.7% and 82.3% against T. aggressivum, T. atroviride, T. harzianum, T. koningii and T.viride, respectively. The n-hexane soluble fraction revealed much higher antifungal activity than the other fractions did. This study demonstrated that the n-hexane fraction of the hot water extracts of L. leptolepis and P. menziesii exhibited the greatest antifungal activity against Trichoderma spp.