• Food Science and Preservation
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• v.11 no.1
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• pp.28-33
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• 2004

Quality and flavor compounds of perilla loaves cultivated in greenhouse(May) and field (August) in Geumsan province were investigated and compared. All perilla leaves contained 4.0％ crude protein and 0.8％ crude lipid. Crude flavonoid contents of perilla leaves cultivated in greenhouse and field showed 25.2％ and 26.5％, respectively and each crude saponin content was 2.7％ and 2.8％. Pretense activity were showed 11.8 unit in ethanol extracts and 7.1 unit in water extracts of perilla leaves cultivated in field. Hardness and chewness of bottom parts of field-perilla leaves were higher than those of top and middle part, whereas the cohesiveness of top parts and middle parts of perilla leaves were higher than that of bottom part. Furthermore, texture properties of greenhouse-perilla leaves were similar with those of field-perilla leaves except chewness. Nine kinds of flavor compounds such as 1-octen-3-ol, linalool, ${\beta}$-caryophyllene, ${\alpha}$-caryophylene, ${\alpha}$-farnesene, perilla ketone, nerolidol, eugenol, ${\alpha}$-cadinol were identified in greenhouse-perilla and field-perilla leaves, showing that main flavor compound was perilla ketone.

• Macromolecular Research
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• v.17 no.10
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• pp.734-738
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• 2009

Biodegradable, pH-sensitive, glycol chitosan (GC) hydrogels were prepared using divinyl adipate (DVA) as a crosslinker and acetic acid as a catalyst. DVA has highly reactive double vinyl ester groups and GC contains a high density of hydroxyl groups, with two in every glucosamine unit. The transesterification reaction between vinyl esters and hydroxyl groups produced crosslinked GC hydrogels. The initial crosslinking reaction was monitored by measuring the viscosity of the reaction mixture. When DVA was added to the GC solution and heated to $50^{\circ}C$, the viscosity of the GC solution gradually increased, implying a crosslinking reaction and hydrogel formation. A new peak from the ester group was observed in the FTIR spectra of the GC hydrogels, confirming the crosslinking reaction. The synthesized GC hydrogel showed pH-dependent water absorbency, mainly due to the presence of amine groups ($-NH_2$) at the C-2 position of the glucosamine unit of GC. The water absorbency greatly increased at acidic pH and slightly decreased at alkaline pH. The GC hydrogel gradually degraded in $37^{\circ}C$ water due to hydrolysis of the ester bonds, which were intermolecular crosslinking sites. A red dye, 5-carboxyltetramethyl-rhodamine (CTMR), was entrapped in the GC hydrogels as a model compound. CTMR was released from GC hydrogels in two steps: an initial burst release mainly due to desorption and diffusion, and a second sustained release possibly due to gradual degradation.

• Korean Chemical Engineering Research
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• v.48 no.5
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• pp.615-620
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• 2010

In this study, five series of novel polyurethanes was synthesized by the polyaddition reaction of diisocyanates such as 2,6-tolylene diisocyanate(2,6-TDI), 2,5-tolylene diisocyanate(2,5-TDI), 2,4-tolylene diisocyanate(2,4-TDI), and 1,4-phenylene diisocyanate(1,4-PDI), hexamethylene diisocyanate(HDI) with 4,4'-Bis(3-hydroxypropoxy)biphenyl (BP3), 4,4'-bis(3-hydroxypropoxy)biphenyl exhibited a smectic type mesophase. Monotropic mesophase was found for all synthesized liquid crystalline polyurethanes except HDI/BP3. In contrast, 1,4-PDI/BP3 without a methyl substituent in the phenylene unit exhibited no explicit mesomorphic behavior, which was confirmed by DSC and polarizing microscopy experiments. Structures of the compound were identified by FT-IR and $^1H$-NMR spectroscopies. Their phase transition temperatures and thermal stability were also investigated by differential scanning calorimetry(DSC), polarized optical microscopy(POM) and x-ray diffraction analysis.

• Korean Institute of Interior Design Journal
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• v.22 no.2
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• pp.203-210
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• 2013

The purpose of this study was to investigate and analyze the function and scale on aspect of construction planning with examples of exhibition and convention facilities constructed recently in domestic and foreign area. Also, it was to provide the result for basic data for construction planning and architecture of similar facilities constructed later. The study methodles, but they had characteristics to use the space with compound purpose for exhibition, conference, etc through installing multi-purpose hall. Finally, for effective construction planning of exhibition and convention facilities, it was required to decrease the ratio of common area gradually and derive rationalization of whole space composition by deriving complexity of function rather than planning of single purpose of each facility for exhibition and conference function. was to analyze the characteristics of construction planning for composition and scale of exhibition, conference, public use, support, maintenance functions, etc and placement composition of unit rooms by each floor on the basis of internal area of exhibition and convention facility in Korea and Japan. As the result of analyzing 10 examples(K1~J5), the placement of auditorium and multi-purpose hall was affected according to location of exhibition room and conference room in the composition of unit rooms by each floor and the installment ratio of support facility in Korean examples was higher than in Japanese examples. In case of facility scale, the Japanese examples were overall small in the whole scale relatively to Korean examp.

• Journal of KIISE:Software and Applications
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• v.30 no.3_4
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• pp.358-371
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• 2003

Automatic word spacing is a process of deciding correct boundaries between words in a sentence including spacing errors. It is very important to increase the readability and to communicate the accurate meaning of text to the reader. The previous statistical approaches for automatic word spacing do not consider the previous spacing state, and thus can not help estimating inaccurate probabilities. In this paper, we propose two statistical word spacing models which can solve the problem of the previous statistical approaches. The proposed models are based on the observation that the automatic word spacing is regarded as a classification problem such as the POS tagging. The models can consider broader context and estimate more accurate probabilities by generalizing hidden Markov models. We have experimented the proposed models under a wide range of experimental conditions in order to compare them with the current state of the art, and also provided detailed error analysis of our models. The experimental results show that the proposed models have a syllable-unit accuracy of 98.33% and Eojeol-unit precision of 93.06% by the evaluation method considering compound nouns.

• Journal of Welding and Joining
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• v.33 no.3
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• pp.19-24
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• 2015

Joint properties of electric control unit (ECU) module using Sn-Cu-(X)Al(Si) lead-free solder alloy were investigated for automotive electronics module. In this study, Sn-0.5Cu-0.01Al(Si) and Sn-0.5Cu-0.03Al(Si) (wt.%) lead-free alloys were fabricated as bar type by doped various weight percentages (0.01 and 0.03 wt.%) of Al(Si) alloy to Sn-0.5Cu. After fabrications of lead-free alloys, the ball-type solder alloys with a diameter of 450 um were made by rolling and punching. The melting temperatures of 0.01Al(Si) and 0.03Al(Si) were 230.2 and $230.8^{\circ}C$, respectively. To evaluation of properties of solder joint, test printed circuit board (PCB) finished with organic solderability perseveration (OSP) on Cu pad. The ball-type solders were attached to test PCB with flux and reflowed for formation of solder joint. The maximum temperature of reflow was $260^{\circ}C$ for 50s above melting temperature. And then, we measured spreadability and shear strength of two Al(Si) solder materials compared to Sn-0.7Cu solder material used in industry. And also, microstructures in solder and intermetallic compounds (IMCs) were observed. Moreover, thickness and grain size of $Cu_6Sn_5$ IMC were measured and then compared with Sn-0.7Cu. With increasing the amounts of Al(Si), the $Cu_6Sn_5$ thickness was decreased. These results show the addition of Al(Si) could suppress IMC growth and improve the reliability of solder joint.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.13
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• pp.5371-5376
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• 2015

Berberine (B1), isolated from stems of Coscinium fenestratum (Goetgh.) Colebr, was used as a principle structure to synthesize three phenolic derivatives: berberrubine (B2) with a single phenolic group, berberrubine chloride (B3) as a chloride counter ion derivative, and 2,3,9,10-tetra-hydroxyberberine chloride (B4) with four phenolic groups, to investigate their direct and indirect antioxidant activities. For DPPH assay, compounds B4, B3, and B2 showed good direct antioxidant activity ($IC_{50}$ values=$10.7{\pm}1.76$, $55.2{\pm}2.24$, and $87.4{\pm}6.65{\mu}M$, respectively) whereas the $IC_{50}$ value of berberine was higher than $500{\mu}M$. Moreover, compound B4 exhibited a better DPPH scavenging activity than BHT as a standard antioxidant ($IC_{50}=72.7{\pm}7.22{\mu}M$) due to the ortho position of hydroxyl groups and its capacity to undergo intramolecular hydrogen bonding. For cytotoxicity assay against human fibrosarcoma cells (HT1080) using MTT reagent, the sequence of $IC_{50}$ value at 7-day treatment stated that B1 < B4 < B2 ($0.44{\pm}0.03$, $2.88{\pm}0.23$, and $6.05{\pm}0.64{\mu}M$, respectively). Berberine derivatives, B2 and B4, showed approximately the same level of CAT expression and significant up-regulation of SOD expression in a dose-dependent manner compared to berberine treatment for 7-day exposure using reverse transcription-polymerase chain reaction (RT-PCR) assays. Our findings show a better direct-antioxidant activity of the derivatives containing phenolic groups than berberine in a cell-free system. For cell-based system, berberine was able to exert better cytotoxic activity than its derivatives. Berberine derivatives containing a single and four phenolic groups showed improved up-regulation of SOD gene expression. Cytotoxic action might not be the main effect of berberine derivatives. Other pharmacological targets of these derivatives should be further investigated to confirm the medical benefit of phenolic groups introduced into the berberine molecule.

• Korean Journal of Microbiology
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• v.40 no.4
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• pp.364-366
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• 2004

The purpose of this work was to investigate the effect oftea catechin, epigallocatechin gallate (EGCG) on killing of oral bacteria. The antibacterial activity of 2.5 mg/ml and 5.0 mg/ml EGCG was investigated for target bacteria of which initial cell number was approximately adjusted to $10^{7}ml$. The antibacterial activity of EGCG was proportional to the concentration according to colony-forming unit(CFU) of target bacteria enumerating on selective and complex media. Streptococcus mutans and Streptococcus sobrinus at 5mg/ml EGCG were completely killed within 8 hrs. Lactobacillus plantarum and Lactobacillus acidophilus were also killed within 2 hrs and 4 hrs under the same conditions, respectively. Oral bacteria at 2.5 mg/ml EGCG were completely killed within 10 hr. Colony numvers of S. mitis and S. salivarius treated with 2.5 mg/ml EGCG were decreased on MS solid media and no colony was observed on the media within 12 hrs. In consequence, EGCG would be a natural and effective compound that kill oral bacteria being caused of bad breath, plaque and gingivitis, and for preventing and treating dental caries.

• Journal of the Korean Chemical Society
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• v.55 no.2
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• pp.199-203
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• 2011

The title one-dimensional hydrogen-bonded coordination compound $[Cu^{II}(C_{13}H_{17}N_3OBr)(C_8H_5O_4)]{\cdot}2H_2O.CH_3OH$ has been synthesized and characterized by single crystal X-ray diffraction study. The monomeric unit contains a square-planar $Cu^{II}$ centre. The four coordination sites are occupied by a tridentate anionic Schiff base ligand (4-bromo-2-[(2-piperazin-1-yl-ethylimino)-methyl]-phenol) which furnishes an $N_2O$-donor set, with the fourth position being occupied by the oxygen atom of an adjacent terephthalate unit. Two adjacent neutral molecules are linked through intermolecular N-H---O and O-H---N hydrogen bonds and generate a dimeric pair. Each dimeric pair is connected with each other via discrete water and methanol molecules by hydrogen bonding to form a one-dimensional supramolecular network.

• KIEAE Journal
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• v.10 no.5
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• pp.115-121
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• 2010

Lime was the solidifier mostly used at the fields of construction and civil works in the past. however, the development of Portland cement remarkably reduced the use of it. Recently as the concernment on circumstances gets higher, lime wined attention again as an eco-friendly material and was used at earth-using construction. This study examined the physical and chemical capacity of lime complexes with lime capacity improved, and performed fundamental study on the way to concretize by mixing it with earth. As a result, lime complex pressure strength was lower than cement pressure strength but it showed the possibility that its strength was improved by W/B control. The measurement of XRD after paste formation confirmed a compound generated by the reaction of Ca2+ion and Si, Al, and Fe from pozzolan reaction. A earth wall experiment by using lime complexes and earth showed that the higher, WB or the lower the quantity of unit combined materials, the lower the pressure strength was. The maximum pressure strength was maximum 11MPa when the quantity of unit combined materials was 450. It is because the composed earth particles had a high content of micro powder less than silt, so a lot of combination are demanded to secure fluidity. As a result of peptization experiment, after hardening, the material was not dissolved, which informed of the possibility of use as an outer subsidiary material. If the material is hardened by mold formation method, natural hardening crack appears. Cast expresses smart surface quality and enables to design for multiple purpose. The result shows the possibility of construction of low-story structures by using earth wall made of lime complexes and earth.