• Journal of Pharmaceutical Investigation
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• v.2 no.1
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• pp.40-51
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• 1972

Water vapor sorption of corn starch in various protective film coated capsules in 100% RH chamber for 14 days were as follows: The percent of water vapor sorption were 28.63% in uncoated capsule, 25.16% in hydroxy propylcellulose(HPC) coated capsule, 15.59% in 2-methyl-5-vinyl pyridine-methyl acrylated-methacrylic acid (MPM) coated capsule and 15.50% in polyvinyl acetal diethyl amino acetate(AEA) coated capsule. 2. Water vapor sorotion of magnesium trisilicate in various protective film coated capsules in 100% RH chamber for 14 days were as follows. The percent of water vapor sorption were 13.91% in uncoated capsule, 13.30% in HPC-coated capsule, 10.87% in MPM-caated capsule and 9.9% in AEA-coated capsule. 3. Water vapor sorption of magnesium carbonate in various protective film coated capsules in 100% RH chamber for 14 days were as follows: The percent of water vapor sorption were 12.48% in uncoated capsule, 10.72% in HPC-coated capsule, 8.10% in MPM coated capsule and 7.8% in AEA-coated capsule. 4. MPM-coated capsules and AEA-canted capsules were mere effective to protect water vapor sorption than HPC-coated capsules.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.50 no.4
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• pp.453-457
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• 2017

The proximate, fatty acid and dimethyl acetal (DMA) composition, and mineral and total amino acid content of limpets Cellana spp. were studied. Limpets contained 17.6% protein, 1.82% lipids, and 1.28% ash. The most prominent fatty acids in limpets were 20:4n-6, 20:5n-3, 18:1n-9, 16:0, 18:0, and 22:2 nonmethylene-interrupted diene (7,13). Limpets contained significant amounts of 18:0DMA (7.79%) and 20:0DMA (2.45%) derived from plasmalogen. They also contained large amounts of calcium (192.4 mg/100 g) and iron (9.4 mg/100 g), which are components of limpet teeth. The most prominent total amino acids were glutamic acid, arginine, aspartic acid, leucine, lysine, and glycine. These results suggest that limpets are a good source of n-3 and n-6 fatty acids, plasmalogen, calcium iron, and arginine.

• Proceedings of the KAIS Fall Conference
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• 2011.05a
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• pp.141-143
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• 2011

Al-SBA-1(Si/Al = 40, 80 and 120) and Al,Mg-SBA-1 (Si/(Al+Mg) = 40 and 80) molecular sieves were synthesized and characterized. Acetalization of n-heptanal with methanol was studied under autogenous pressure between 80 and $150^{\circ}C$. Since protonation of n-heptanal was fast, addition of methanol to the same to formed hemiacetal slowly whereas conversion of hemiacetal to acetal was fast. The catalysts exhibited nearly similar conversion irrespective of their difference in acidity, and all of them showed more than 80 % conversion either at 80 or $100^{\circ}C$. Hence it is evident that the difference in acidity is not so important in differentiating the activity of the catalysts. The large pore size and hydrophilic and hydrophobic properties are suggested to be the main factors that control acetalization.

• Bulletin of the Korean Chemical Society
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• v.30 no.1
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• pp.163-171
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• 2009

Few $\alpha$-Hydroxy-$\beta$-amino acids were synthesized via various nucleophilic addition of the epoxide and followed by stereoselective nucleophilic substitution reaction and eliminative cleavage of the acetal selectively in diacetal compound. One of the synthesized $\alpha$-Hydroxy-$\beta$-amino acid reacted with L-leucine methylester to give corresponding dipeptide in good yields.

• Geomechanics and Engineering
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• v.21 no.3
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• pp.227-236
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• 2020

Non-destructive exploration using elastic waves has been widely used to characterize rock mass properties. Wave propagation in jointed rock masses is significantly governed by the characteristics and orientation of discontinuities. The relationship between spatial heterogeneity (i.e., joint spacing) and wavelength for elastic waves propagating through jointed rock masses have been investigated previously. Discontinuous rock masses can be considered as an equivalent continuum material when the wavelength of the propagating elastic wave exceeds the spatial heterogeneity. However, it is unclear how stress-dependent long-wavelength elastic waves propagate through a repetitive rock-joint system with multiple joints. A preliminary numerical simulation was performed in in this study to investigate long-wavelength elastic wave propagation in regularly jointed rock masses using the three-dimensional distinct element code program. First, experimental studies using the quasi-static resonant column (QSRC) testing device are performed on regularly jointed disc column specimens for three different materials (acetal, aluminum, and gneiss). The P- and S-wave velocities of the specimens are obtained under various normal stress levels. The normal and shear joint stiffness are calculated from the experimental results using an equivalent continuum model and used as input parameters for numerical analysis. The spatial and temporal sizes are carefully selected to guarantee a stable numerical simulation. Based on the calibrated jointed rock model, the numerical and experimental results are compared.

• Archives of Pharmacal Research
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• v.19 no.4
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• pp.321-325
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• 1996

Aiming at the development of anticancer agents by modification of phenolic benzo[c]phenanthridine alkaloid, additional hydroxyl group was put on C10 position of fagaridine (1) by a biomimetic synthetic procedure to afford 10-hydroxyfagaridine (12). All of the synthetic intermediates were also screened in vitro antitumor activities against five different cell lines as well as 12. Among them the representative cytotoxic results are shown as follows; P-quinone (11) $[ED_50;(A549=0.22; {\mu}g/ml)$, $(HCT;15=0.21 {\mu}g/ml)$, fagaridine (1) $(HCT;15=0.41 {\mu}g/ml)$, olefin (6) $(HCT; 15=0.06 {\mu}g/ml)$, acetal (7) $(SKMEL-2=0.07 {\mu}g/ml)$, dihydrofagaridne (10) $(A549=0.38 {\mu}g/ml)$, 10-hydroxyfagaridine (12) $(A 549=0.45{\mu}g/mi)$. From these observation three main remarks can be drawn; (i) the iminium part of benzo[c]phenanthridine is not essential for showing acitvities, (ii) the additional hydroxyl group did not contribute to enhance the cytotoxicity, (iii) the 3-arylisoquinolin-1(2H)-one derivatives were found to display significant in vitro antitumor activity.

• Journal of the Korean Applied Science and Technology
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• v.13 no.3
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• pp.61-71
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• 1996

In acid-catalyzed acetal cyclization of long aliphatic aldehydes($R=n-C_7H_{15}$ ; $n-C_9H_{19}$ ; $n-C_{11}H_{23}$) with 1,1,1-tris(hydroxymethyl)propane, 2-alkyl-5-hydroxymethyl-5-ethyl-1,3-dioxanes were obtained. The final products, sodium 2-alkyl-5-(sulfonatedpropylethermethyl)-5-ethyl-1,3-propanesultion in the presence of sodium hydride. These compounds were a new group of destructible surfactants which were readily hydrolyzed and oxidized in natural water reservoirs. Physical properties of these new compounds involved some surface properties such as Krafft point(Kp), critical micelle concentration(cmc), surface tension of aqueous solutions near cmc(${\gamma}_{min}$), foaming power, emulsion power and hydrolysis properties were determined. The destructible surfactants containing 1,3-dioxane ring were synthesized to about $85{\pm}5.5%$ yield. The cmc values of the compounds by ring method were assumed to $0.5{\sim}5.0{\times}10^{-3}mol/L$ range and surface tensions at cmc were $29.5{\sim}33.0dyne/cm$ respectively at $25^{\circ}C$. The foaming power and foam stability were $170{\sim}230mm$ and $52{\sim}135mm$ respectively at $1{\times}10^{-2}mol/L$, foam was occurred rarely below $1{\times}10^{-3}mol/L$. The emulsion property of liquid paraffin was better than that of soybean oil. For hydrolysis property with ph and time, these compounds were decomposed within about 200minutes at $ph1{\sim}2$. Hopefully these compounds are expected to be a good O/W emulsifier that have decomposability in acid and may be used in the process which do not need foaming.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.48 no.6
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• pp.977-981
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• 2015

The proximate, fatty acid and dimethyl acetal (DMA) compositions of domestic and imported melania snails Semisulcospira sp. being sold commercially were studied. The protein content ranged from 8.09% (China) to 11.3% (North Korea). The lipid content ranged from 0.84 (China) to 2.36% (North Korea). Domestic melania snail had protein (10.5%) and lipid (1.02%) contents intermediate between those of the two imported melania snails. The prominent fatty acids were 16:0 and 18:0 saturated fatty acids, 16:1n-7, 20:1n-11, 18:1n-9, 18:1n-7 and 16:1n-9 monounsaturated fatty acids, and 20:4n-6, 20:5n-3 (eicosapentaenoic acid, EPA), 22:2 non-methylene-interrupted diene (NMID), 18:3n-3, 18:2n-6 and 22:5n-3 (docosapentaenoic acid, DPA) polyunsaturated fatty acids (PUFA). The percentage of n-3 PUFA was higher in domestic (19.6%) and North Korean (imported, 19.5%) snails than in that from China (imported, 16.8%), while the n-6 PUFA level was higher in snails from China (21.2%) and domestic snails (14.7%) than in that from North Korea (9.87%). The total DMA, i.e., 18:0 DMA, 16:0 DMA and 18:1 DMA was 7.30, 7.27, and 4.86% domestic snail and those from China and North Korea, respectively. These results suggest that melania snail is a source of n-3 PUFA, and DMA derived from plasmalogen.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.220-220
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• 2011

The Ne-Xe plasmas in dense plasma-focus device with coaxial electrodes were generated for extreme ultraviolet (EUV) lithography. The influence of gas mixture ratio, Ne-Xe (1, 10, 15, 20, 25, 30, 50%) mixture gas, on EUV emission measurement, EUV intensity and electron temperature in the coaxially focused plasma were investigated. An input voltage of 4.5 kV was applied to the capacitor bank of 1.53mF and the diode chamber was filled with Ne-Xe mixture gas at a prescribed pressure. The inner surface of the cylindrical cathode was lined by an acetal insulator. The anode was made of tin metal. The EUV emission signal of the wavelength in the range of 6~16 nm has been detected by a photo-detector (AXUV-100 Zr/C, IRD). The visible emission line was also detected by the composite-grating spectrometer of the working wavelength range of 200~1100 nm (HR 4000CG). The electron temperature is obtained by the optical emission spectroscopy (OES) and measured by the Boltzmann plot with the assumption of local thermodynamic equilibrium (LTE).

• Journal of the Korean Chemical Society
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• v.36 no.2
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• pp.197-204
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• 1992

The cationic polymerization of cyclic acetals are investigated theoretically using the semiempirical MINDO/3, MNDO, and $AM_1$, methods. The nucleophilicity and basicity of cyclic acetals can be explained by the negative charge on oxygen atom of cyclic acetals. The reactivity of propagation in the polymerization of cyclic acetals can be represented by the positive charge on $C_2$ atom and the low LUMO energy of active species of cyclic acetals. The reactivity of 2-buthyl-1,3-dioxepane(2-Bu-DOP) of cyclic oxonium and opening carbenium ion form is expected computational stability of the oxonium ion by 5${\sim}$7kcal/mole favoring the carbenium ion. Owing to the rapid equilibrium of these cation forms and the reaction coordinate based on calculation that the reaction coordinate based on calculation that the chain growth $S_N1$ mechanism will be at least as fast as that for $S_N2$ mechanism.