• Proceedings of the Korean Institute of Resources Recycling Conference
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• 2001.05b
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• pp.129-132
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• 2001

The purpose of this research was to understand possibility of foodwaste treatment by hybrid anaerobic reactor(HAR). The Possibility of methane utility and applicability of hybrid reactor system using foodwaste as substrate was investigated. The maximum loading rate and optimized operational conditions were determined. Hybrid anaerobic reactor was filled with packing material 50% of its total volume between the tube and the outer surface. The packing material used was randomly packed open-pore synthesis activated ceramic(SAC) media as support media for microbial attachment, growth, and chemical stability protected bacteria from effect of organic acid accumulation. In this research, although foodwaste has high concentrations C $l^{[-10]}$ and S $O_{4}$$^{2-}$ concentration the possibility of foodwaste anaerobic treatment was when foodwaste is treated by anaerobic digestion, this study focused on the possibility using C $H_4$ gas made under the anaerobic treatment as an alternative energy source. Other objective of this research is to study struvite formation and crystal forms in anaerobic digester. HAR is used to investigate phosphate crystallization without the addition of chemicals.

• Journal of the Korean Ceramic Society
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• v.40 no.6
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• pp.601-607
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• 2003

Osteoblast-like cell morphology, proliferation, and differentiation were examined in variation with biomaterials. Cells were cultured on TiO$_2$, Ti, 3Y-TZP, HA (Hydroxyapatite) and Thermanox was used as a control specimen. Generally, all specimens have similar cell morphology within the same time interval. However, cells on HA seem to be more thicker than those on TiO$_2$, Ti, 3Y-TZP and cell overlapping was detected very frequently on HA. In case of cell proliferation and differentiation, bioactive material such as HA could help osteoblast-like cell proliferate and provoke a sharp increase of ALP. On the other hand, whether the substrate material is a bioinert ceramics or metal, it does not so strongly affect the cell attachment, proliferation. and differentiation.

• Animal cells and systems
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• v.13 no.2
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• pp.161-167
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• 2009

The cuticle of spider's exoskeleton is a hydrophobic and non-adhesive material, but the jumping spiders have the distinctive attachment apparatus for adhesion on smooth dry surface without sticky fluids. We have examined the whole tarsal appendages of the jumping spider, Plexippus setipes with using scanning electron microscope to reveal the fine structural characteristics of the dry adhesion system. All eight legs have the scopulae with a pair of claws on the tip of feet. Each scopula is composed of two groups of setae that are capable of dry adhesion on smooth surface, and the hook structure of the claw is advanced to move on the rough surface. The setae toward the bottom of the tarsal segment are densely covered by numerous setules on the underside which broadened from middle to distal portion. It has been revealed by this research that the contact area of the setule is always a triangular shape, and these cuticular surfaces are connected by the elongated stalks from the underlying setae. It is likely that the nano-scale structures including a triangular depression and a longitudinal groove on each setule could functionate when the spider detach its feet from the substrate.

• Journal of Microbiology and Biotechnology
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• v.20 no.10
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• pp.1393-1396
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• 2010

The attachment of sugar to flavonoids enhances their solubility. Glycosylation is performed primarily by uridine diphosphate-dependent glycosyltransferases (UGTs). The UGT from Bacillus cereus, BcGT-1, transferred three glucose molecules into kaempferol. The structural analysis of BcGT-1 showed that its substrate binding site is wider than that of plant flavonoid monoglucosyltransferases. In order to create monoglucosyltransferase from BcGT-1, the error-prone polymerase chain reaction (PCR) was performed. We analyzed 150 clones. Among them, two mutants generated only kaempferol O-monoglucoside, albeit with reduced reactivity. Unexpectedly, the two mutants harbored mutations in the amino acids located outside of the active sites. Based on the modeled structure of BcGT-1, it was proposed that the local change in the secondary structure of BcGT-1 caused the alteration of triglucosyltransferase into monoglucosyltransferase.

• Bulletin of the Korean Chemical Society
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• v.33 no.11
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• pp.3735-3739
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• 2012

We have developed magnetically controllable gold nanoparticles by synthesizing superparamagnetic $Fe_3O_4$ core/gold shell nanoparticles. The core/shell particles have the capability of forming gold 1D chains in the presence of an external magnetic field. Here we demonstrate dynamic and reversible self-assembly of the gold 1D chain structures in an aqueous solution without any templates or physical or chemical attachment. The spatial configuration of gold chains can be arbitrarily manipulated by controlling the direction of a magnetic field. This technique can provide arbitrary manipulation of gold 1D chains for fabrication purpose. To demonstrate this capability, we present a technique for immobilization of the gold particle chains on a glass substrate.

• The Korean Journal of Ceramics
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• v.6 no.4
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• pp.354-358
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• 2000

The SnO$_2$film was deposited on a corning glass 1737 substrate by plasma enhanced chemical vapor deposition using a gas mixture of SnCl$_4$, $O_2$, and Ar. The film thickness was measured using $\alpha$-step and was about 9400$\AA$. The conventional X-ray diffractometry and pole figure attachment were used to refine the crystal structure of SnO$_2$ thin film. Six pole figures, (200), (211), (310), (301), (321), and (411), were measured with CoK$_\alpha$ radiation in reflection geometry. The X-ray diffraction data were measured at room temperature using CuK$_\alpha$ radiation with graphite monochromator. The agreement between calculated and observed patterns for the normal direction of SnO$_2$ thin film was not satisfactory due to the severely preferred orientation effect. The Rietveld refinement of heavily textured SnO$_2$ thin film was successfully achieved by adopting the pole density distribution of each reflection obtained from the inverse pole figure as a correction factor for the preferred orientation effect. The R-weighted pattern, R$_wp$, was 15.30%.

• ALGAE
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• v.36 no.2
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• pp.147-154
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• 2021

Kelp life history pathways alternate between macroscopic sporophytes that produce spores and microscopic gametophytes that produce gametes. Occasionally, an alternative pathway is seen. This study examined the circumstances by which the high latitude estuarine bull kelp, Nereocystis luetkeana, foregoes the "free-living microscopic stages by releasing embryonic sporophytes directly from sori. Sori were collected from adult N. luetkeana sporophytes from eight locations within Kachemak Bay, Alaska in 2018 and 2020 to examine spatial and temporal development of embryonic sporophytes on sori. Distinctions were made between sori collected from first-generation and overwintered adults to assess the influence of parental age on embryonic sporophyte release. Further distinctions were made between sori collected from attached and drifting individuals to assess the influence of the status of parental attachment to substrate on embryonic sporophyte release. Inspection of propagules released from sori after 48-h incubations indicated that embryonic sporophytes were occasionally released alongside viable spores. Though embryonic sporophytes were released from sori as early as spring, it was not evident that they were bound by seasonal or spatial limits. The percent of propagules that were embryonic sporophytes ranged from 0% to 100% but were not significantly different between first-generation and overwintered adults, nor were they different between attached and drifting individuals. Nevertheless, the characteristic of directly releasing embryonic sporophytes from adult sporophytes might have ecological advantages for N. luetkeana.

• Korean Journal of Materials Research
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• v.28 no.11
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• pp.615-619
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• 2018

To produce carbon electrodes for use in perovskite solar cells, electrode samples are prepared by mixing various weight ratios of 35 nm nano carbon(NC) and $1{\mu}m$ graphite flakes(GF), GF/(NC+GF) = 0, 0.5, 0.7, and 1, in chlorobenzene(CB) solvent with a $ZrO_2$ binder. The carbon electrodes are fabricated as glass/FTO/carbon electrode devices for microstructure characterization using transmission electron microscopy, optical microscopy, and a field emission scanning electron microscopy. The electrical characterization is performed with a four-point probe and a multi tester. The microstructure characterization shows that an electrode with excellent attachment to the substrate and no surface cracks at weight ratios above 0.5. The electrical characterization results show that the sheet resistance is <$70{\Omega}/sq$ and the interface resistance is <$70{\Omega}$ at weight ratios of 0.5 and 0.7. Therefore, a carbon paste electrode with microstructure and electrical properties similar to those of commercial carbon electrodes is proposed with an appropriate mixing ratio of NC and GF containing a CB solvent and $ZrO_2$.

• Korean Journal of Environmental Biology
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• v.39 no.3
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• pp.383-389
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• 2021

The Erythropeltidales are a common group of small, mostly epiphytic, marine red algae. However, they are little known in Korea. Many of the described species of Erythropeltidales differ subtly in morphology, and often the morphological differences are due to the substrate or environmental changes. Integration of molecular data with standardized culture conditions has been recommended to account for these algae. A Madagascaria species was first collected from the western coast of Korea and was identified as Madagascaria erythrocladioides based on the morphological and molecular characteristics. Morphological characteristics conformed well with its original description, and the phylogenetic analysis based on rbcL sequence showed Korean M. erythrocladioides nests in the same clade with the original species described in Japan with a genetic distance of 0.0-0.1%. This species was isolated from a red alga, Pterocladiella capillacea, in laboratory culture. The thallus ontogeny and host preference were examined by a co-culture with 13 different species of algae. Results showed a relatively broad host preference in mono-spore attachment and epiphyte development of Madagascaria erythrocladioides. Mono-spores of M. erythrocladioides attached to most of the red algal hosts' surfaces but no crustose thalli developed on some of the algal hosts even after one month of co-culture.

• Polymer(Korea)
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• v.34 no.4
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• pp.313-320
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• 2010

New cinnamate group-containing copolymers for a self-curable, humidity-sensitive polyelectrolyte and polymeric anchoring agents were prepared by copolymerization of [2-[(methacryloyloxy) ethyl]dimethyl]propyl ammonium bromide(MEPAB), methyl methacrylate(MMA), 3-(trimethoxysilyl) propyl methacrylate(TMSPM) and 2-(cinnamoyloxy)ethyl methacrylate(CEMA). Photocrosslinkable copolymer composed of MEPAB/MMA/TMSPM/CEMA＝70/20/0/10 were used for humidity-sensitive membrane, and those of 50/0/20/30 and 0/0/50/50 were used for polymeric anchoring agents. 3- (Triethoxysilyl)propyl cinnamate(TESPC) was also used as a surface-pretreating agent for the comparison of capability of attachment of polyelectrolyte to the electrode surface with polymeric photocurable silanecoupling agents. Pretreatment of the electrode substrate with anchoring agents was performed to form a cinnamate thin film on the electrode through covalent bonds. When the sensors were irradiated with UV light, the anchoring of a polyelectrolyte into the substrate was carried out via the [2$\pi$+2$\pi$] cycloaddition. The resulting sensors using polymeric anchoring agents and TESPC showed water durability with increase of resistance by 60~85%, which is corresponding to the reduction of 2.25~3.15%RH, after soaking in water for 24 h. They showed good hysteresis (-0.2%RH), response time (90 sec) and long-term stability at high temperature and humidity.