• Bulletin of the Korean Chemical Society
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• v.35 no.1
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• pp.243-249
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• 2014

Three single crystals of fully dehydrated $Co^{2+}$-exchanged zeolite Y (Si/Al = 1.56) were prepared by the exchange of $Na_{75}$-Y ($|Na_{75}|[Si_{117}Al_{75}O_{384}]$-FAU) with aqueous streams 0.05 M in $Co(NO_3)_2$, pH = 5.1, at 294 K for 6 h, 12 h, and 18 h, respectively, followed by vacuum dehydration at 673 K. Their single-crystal structures were determined by synchrotron X-ray diffraction techniques in the cubic space group Fd3m at 100(1) K. They were refined to the final error indices $R_1/wR_2$ = 0.0437/0.1165, 0.0450/0.1228, and 0.0469/0.1278, respectively. Their unit-cell formulas are $|Co_{29.1}Na_{11.8}H_{5.0}|[Si_{117}Al_{75}O_{384}]$-FAU, $|Co_{29.8}Na_{11.0}H_{4.4}|[Si_{117}Al_{75}O_{384}]$-FAU, and $|Co_{30.3}Na_{9.5}H_{4.9}|[Si_{117}Al_{75}O_{384}]$-FAU, respectively. In all three crystals, $Co^{2+}$ ions occupy sites I, I' and II; $Na^+$ ions are also at site II. The tendency of $Co^{2+}$ exchange slightly increases with increasing contact time as $Na^+$ content and the unit cell constant of the zeolite framework decrease.

• Journal of Bio-Environment Control
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• v.21 no.4
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• pp.404-410
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• 2012

This study was conducted to examine effects of harvest time (09:00 vs. 14:00), precooling at $4^{\circ}C$ vs. no precooling, and storage temperature (4 vs. $8^{\circ}C$) on the storage life of 'Maehyang' strawberry fruits for export. Fruits at a 60% ripe stage were harvested from a commercial greenhouse in Gyeongsangnamdo, Jinju on May 4, 2010. Fruits were precooled by a forced draft cooling for three hours, transported for about 30 minutes and then stored, immediately. Small precoolers set in the farm were used for precooling. Fruits were placed in constant temperature chamber (4 or $8^{\circ}C$) after packaging using PVC wrap and a cardboard box. Fruits were examined for their changes in weight, hardness, Hunter color values, soluble solids content (SSC), and incidence of gray mold (Botrytis cinerea) during storage at a two days interval from May 6 to May 14, 2010. Hardness and SSC decreased as the ripening stage progressed. The Hunter's 'L' and 'a' value of fruit color decreased as time passed. Also, fresh weight decreased during storage at all temperatures. Soft rot appeared on epidermal tissues and followed by gray mold. Incidence of gray mold was greater at $8^{\circ}C$ storage temperature than in $4^{\circ}C$ storage temperature. However, no difference by the harvested time and precooling. The results indicate that effectiveness for keeping the freshness was best achieved by precooling at $4^{\circ}C$ and storage at $4^{\circ}C$, respectively.

• Cross-Cultural Studies
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• v.42
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• pp.419-449
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• 2016

The Russian icon and Korean tangwha (幀畵, altar portrait of Buddha) are based on the similarity of the divine Being. Each has the characteristic index that forms an existential connection with the object and at the same time, implies the symbolic meaning of the scriptures and doctrines of the Russian Orthodox and Buddhists. Russian icon and Korean tangwha with these attributes have origins in the Byzantine, India and China. Unlike most religious art, Russian icon and Korean tangwha clearly reveal profane orientation and mystical elements. This artistic phenomenon has evolved from the mystical religious culture in Russia and tantric rituals of the early Joseon period. Iconostasis, created from historical figures of the Old Testament, Jesus, the New Testament represent the principles of the macrocosm. Each icon of iconostasis has integrity, while each floor has another narrative and a meta-discourse on the entire composition. Three-Platforms of amrtakundalin can also have a huge epic that is directed from the Low-Platform to the High-Platform for the purpose of salvation. While the narrative of iconostasis has a time structure, from the beginning of the universe up to date in chronological time, amrtakundalin have pictorial transitions of time and space that rises from this life to a heavenly world. Despite the different world views of the Russian Orthodox and Buddhists, iconographical format and symbolism of heaven and hell in the Iconostasis, Last Judgment and amrtakundalin are similar. There is a constant antagonism between heaven and hell, light and darkness, water and flame. Iconographical contents include the water of life and nectar, the book of life and 'eoppu', and the scales and mirror of Karma that discriminate between the good and evil before judgment. The dualistic coordinate concept such as light and darkness, life and death, or heaven and hell that appears in the narrative structure of iconostasis, the Last Judgment and amrtakundalin leads the people to spiritual awakening.

• Journal of Microbiology
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• v.40 no.1
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• pp.33-37
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• 2002

An enzymatic reaction for the production of D-alanine from D-aspartic acid and pyruvate as substrates by a thermostable D-amino acid aminotransferase (D-AAT) was investigated at various conditions In the temperature range of 40-70$\^{C}$ and pH range of 6.0-9.5. The D-AAT was produced with recombinant E. coli BL21, which hosted the chimeric plasmid pTLK2 harboring the D-AAT from the novel thermophilic Bacillus sp. LK-2. The enzyme reaction was shown to follow the Ping Pong Bi Bi mechanism. The K$\_$m/ values for D-aspartic acid and pyruvate were 4.38 mar and 0.72 mM, respectively. It was observed that competitive inhibition by D-alanine, the product of this reaction, was evident with the inhibition constant K$\_$i/ value of 0.1 mM. A unique feature of this reaction scheme is that the decorboxylation of oxaloacetic acid, one of the products, spontaneously produces pyruvate. Therefore, only a catalytic amount of pyruvate is necessary for the enzyme conversion reaction to proceed. A typical time-course kinetic study skewed that D-alanine up to 88 mM could be produced from 100 mM of D-aspartic acid with a molar yield of 1.0.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2009.04a
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• pp.310-315
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• 2009

Current improvements on the standard of living reduced working hours and increased leisure time. Therefore, people's ideas on life style changed and different demands on residential environment are being made. Residents of apartment want a community facility that enables constant exchange with other residents and supports living. Ideas on how to use physical space to strengthen a community is becoming an issue these days. Community facility plays a crucial role in giving a certain characteristic to the whole apartment and improving the image as a community. It also provides a physical environment and induces active participation of community life from apartment residents. The community facility in an important environment for children, which helps them develop in growth and in society as well. Community facility is a space where children fulfill their curiosity and amusement. Since children are greatly influenced by the physical surroundings, community facility for children should not remain as a space for fun but should change into a space for interaction. This study chose six apartments at Dongtan New Town, located in Hwaseong, Kyunggido. This study focuses on the characteristics of design for children's community facility and would like to make a proposal about future space planning for children's community facility.

• Journal of the Korean institute of surface engineering
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• v.30 no.4
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• pp.262-271
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• 1997

Nickel-matal hydride(Ni-MH) batteries are receiving attention as non-pollunting. high performance rehargeable energy stoage system. The performance of Ni-Mh is significantly influenced by the hydrogen storage alloy materiels used as an anode material. Recently, having discharge capacities higher than the $AB_5$-type hydrogen storage alloys, the Zr-based $AB_2$-Type hydrogen storage alloys has remaining problems regarding cycle life and self-dischareg. These problems need to be solved by improvements in the alloy design and/or surface treatment. This work investiggates the effects the effects of surface property by fluorination on $Zr_{0.7}Ti_{0.3}V_{0.4}Mn_{0.4}Ni{1.2}$ composittion $AB_2$-Type hydrogen storage alloys. EPMA, SEM and AES techniques were used for surface analysis, and the crystal structure was characterized by constant current cycling test and potential sweep methods. Fluorination was found to be effective when La-was incorporated into the alloy, and has unique morphology, higher reactivity, and at the same time formed a protective film. Through, fluorination, the cycle life of an electrode was found to increase significantly, charge/discharge characteristics of the electrode the potential difference between the charge/discharge plateau, i.e polarization(overpotential)were improved.

• Archives of Pharmacal Research
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• v.25 no.5
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• pp.643-646
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• 2002

The succinic semialdehyde dehydrogenase (SSADH) inhibitory component was isolated from the EtOAc fraction of Lactuca sativa through repeated column chromatography; then, it was identified as phytol, a diterpenoid, based on the interpretation of several spectral data. Incubation of SSADH with the phytol results in a time-dependent loss of enzymatic activity, suggesting that enzyme modification is irreversible. The inactivation followed pseudo-first-order kinetics with the second-rate order constant of $6.15{\times}10^{-2}mM^{-1}min^{-1}.$ Complete protection from inactivation was afforded by the coenzyme $NAD^{+}$, whereas substrate succinic semialdehyde failed to prevent the inactivation of the enzyme; therefore, it seems likely that phytol covalently binds at or near the active site of the enzyme. It is postulated that the phytol is able to elevate the neurotransmitter GABA levels in central nervous system through its inhibitory action on one of the GABA degradative enzymes, SSADH.

• Journal of the East Asian Society of Dietary Life
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• v.10 no.6
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• pp.514-521
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• 2000

This study was induced to compare retrogradation and gelatinization in sulgie with added powder and flower of gamkug, which had been stored in 4$^{\circ}C$, 1$0^{\circ}C$ and 3$0^{\circ}C$, respectively. The addition of 5% powdered gamkug showed the highest degree of gelatinization while the control did the lowest. The degree of hardness of gamkugsulgie was lower than control and the following order 4$^{\circ}C$>1$0^{\circ}C$>3$0^{\circ}C$. Gamkugsulgie showed a little lower degree of retrogradation than control group. The degree of retrogradation at 4$^{\circ}C$ was far greater comparing with the other group. The degree of retrogradation were delayed as the storing temperature rose tran 4$^{\circ}C$ to 3$0^{\circ}C$, temperature namely, gamkugsulgie retrogradation time constant of the test group was slower 1.18 times at 4$^{\circ}C$. 1.24 times at 1$0^{\circ}C$ and 2.58 times at 3$0^{\circ}C$ than that of the control group.

• Journal of the Korean Wood Science and Technology
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• v.22 no.2
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• pp.61-70
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• 1994

This study was executed to find the applicability of press drying of tree disk by investigating the shrinkage and drying defect and to form appropriate model by comparing the actual moisture content(MC) and internal temperature in respect of drying time with calculated values based computer simulation to which was applied finite difference method. In press drying disk, heating period, constant drying rate period maintained plateau temperature at 100$^{\circ}C$ and falling drying rate period were significantly distinguished. Actual MC and internal temperature were analogous to those calculated at comparing points. Heat transfer model formed by Fourier's law using specific heat of moist wood and conduction coefficient considering fractional volume of each element of wood cell wall, bound water, free water and air showed applicability as basic data to developing heat expansion, shrinkage and drying stress during press drying. Also mass transfer model formed by Fick's diffusion law using water vapor diffusion coefficient showed applicability. Longitudinal shrinkage was developed by pressure of hot press and tangential shrinkage was restrained by hygrothermal recovery. The heart check, surface check and ring failure were occurred differently in species, but V-shaped crack didn't develop.

• Journal of Mechanical Science and Technology
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• v.17 no.6
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• pp.836-843
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• 2003

The polymer composites contain numerous internal boundaries and its structural elements have different responses and different resistances under the same service environment. Fatigue phenomenon is much more complex in composites than homogeneous materials. An understanding of the fracture behavior of polymer composite materials subjected to constant and cyclic loading is necessary for predicting the life time of structures fabricated with polymers. There is a need to acquire a better understanding of the fatigue performance and failure mechanisms of composites under such conditions. Therefore, in this study the analyses of fiber orientation and fracture mechanism for low cycle fatigue crack have been studied by SEM and LM for observing the ultrathin sections.