• Bulletin of the Korean Chemical Society
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• 제27권9호
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• pp.1323-1328
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• 2006

Mesoporous nickel intercalated aluminosilicate nanohybrid has been synthesized through a recombination reaction between the colloidal suspension of exfoliated montmorillonite nanosheets and aqueous nickel acetate solution. According to powder X-ray diffraction and field emission-scanning electron microscopic analyses, the intercalation of nickel species expands significantly the basal spacing of the host montmorillonite clay and the crystallites of the intercalation compound are assembled to form a house-of-card structure. $N_2$ adsorption-desorption isotherm measurements with BJH pore analyses clearly demonstrated that the porosity of the intercalate originates mainly from mesopores (diameter $\sim50\;\AA$) formed by the house-of-card type stacking of clay crystallites. From FT-IR and X-ray absorption spectroscopic analyses, it becomes certain that intercalated nickel ion is stabilized in an isolated $NiO_6$ octahedral unit. The present mesoporous intercalation compound is expected to be applicable as efficient catalysts or absorbents.

• Applied Biological Chemistry
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• 제36권5호
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• pp.358-363
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• 1993

박하(Mentha piperita) 세포현탁배양에(-)-menthol 생합성 중간체를 투여하여 배양된 세포의 대사경로를 연구하였다. (-)-Limonene을 투여 하였을 때 이는 다른 대사물로 변환되지 않는 것으로 관찰 되었다. (+)-Pulegone은 (+)-isomenthone 및 (-)-menthone으로 변환되었으며, (-)-menthone은 (-)-menthol로 변환되었다. 이 실험은 현탁배양세포가 대부분의 생합성 활성을 유지하고 있으며 (-)-limonene hydroxylase의 활성이 제한적임을 보여 주었다. (-)-Isopiperitenone을 투여하였을 때는 (+)-pulegone, piperitenone, (-)-7-hydroxyisopiperitenone, (R)- 및 (S)-6-hydroxyisopiperitenone이 생성되었다.

• Journal of Microbiology and Biotechnology
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• 제9권2호
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• pp.230-233
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• 1999

A plasmid vector was constructed for the expression and secretion of Bacillus macerans cyclodextrin glucanotransferase (CGTase) in Bacillus subtilis. The vector, pUBACGT, was composed of the ribosome-binding sequence, signal sequence, and cgt gene from B. macerans under the control of amyR2, the promoter of amyE gene coding for $\alpha$-amylase from B. subtilis var. natto. Bacillus subtilis LKS88, a mutant strain lacking genes for an amylase and two proteases, was used as a host for the transformation of the plasmid vector. The transformants were selected on kanamycin-containing Luria-Bertani plates. The starch hydrolyzing activity was observed on the starch-containing plates by the iodine method and cyclodextrin-forming activity was detected in the culture medium. A SDS-PAGE analysis showed that most of the expressed CGTase in the recombinant B. subtilis was secreted into the medium at a high expression level.

• Advances in nano research
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• 제2권2호
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• pp.111-119
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• 2014

The chemical synthesis of anisotropic defective polyaniline/Ag composite (PANI/Ag) is explored using silver nitrate ($AgNO_3$) as the precursor material. This study provides a simple method for the formation of PANI/Ag nanocomposites at two different aniline concentrations $5{\mu}l$ (PANC5) and $10{\mu}l$ (PANC10). The composite PANC5 exhibits UV-Visible absorption peaks at 436 nm and 670 nm whereas, PANC10 exhibits absorption peaks at 446 nm and 697 nm. This shift is caused by the strong interaction between polyaniline and silver. The characterized FTIR peaks observed at around $3410cm^{-1}$ (PANC5) and $3420cm^{-1}$ (PANC10) was due to the N-H stretching vibrations. The appearance of a broad band instead of a sharp peak can be attributed due to the presence of a high concentration of N-H groups in the nanocomposite. The TEM images show that the sample contains defective spherical, truncated triangular and rod shaped particles. The results showed that the PANI/Ag nanocomposites are composed of nano-sized particles of 43-53 nm that contain Ag domains of 33-37 nm with polymer thickness 5.7-11.2 nm at two different aniline concentrations.

• 한국가구학회지
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• 제23권3호
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• pp.298-304
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• 2012

Since 1990's, a flooring based on plywood has gotten customers' demand. Costs of raw material and production increased because of changed environment of industry. Tropical timber such as Red Meranti (Shorea acuminate) used for raw material of the floor has been depleting beside countries in South Eastern Asia changed species of afforestation. As a result, it gets hard to secure good quality of raw material for plywood. Moreover plywood price is increased suddenly after earthquake in Japan. Eucalyptus (Eucalyptus globulus) in china has been using for raw material as a countermeasure of changed environment of industry. In this study, possibility of using flooring consisted of Eucalyptus veneer as a core layer was checked by heat transfer experiments. Flooring consisted of Red Meranti was used for comparison. Two factors which impact on heat transfer are a type of density gradient and density difference between Long-grain veneer and Short-grain veneer. Red Meranti samples are 'M' type of density gradient on the other hand Eucalyptus samples are 'W' type of density gradient.

• Fisheries and Aquatic Sciences
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• 제16권1호
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• pp.25-34
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• 2013

Early ontogenic development in Siberian sturgeon Acipenser baerii was documented and the effects of different temperatures on embryonic and prelarval development were examined. Photograph-assisted data on morphogenesis in Siberian sturgeon prolarvae agreed well with published descriptions of their ontogeny and ecological behaviors, although certain aspects of differentiation, such as gill covering and scute development, could be rearing condition-sensitive. The present study provides the first characterization of the transient development of teeth during early larval stages; the pattern was congruent with the transition of prolarvae to exogenous feeding. From examinations of embryonic and prelarval development under different temperature conditions ($12-24^{\circ}C$), developmental speed was inversely related with temperature. Overall, hatchability was higher and hatching events were more synchronized at $20^{\circ}C$ than at lower temperatures. After hatching, similar patterns of temperature-dependency were observed in yolk sac absorption and the evacuation of the pigment plug. Our results suggest that the incubation of Siberian sturgeon embryos and prolarvae at temperatures close to $20^{\circ}C$ would be advantageous in hatcheries, based on reductions in the duration and uniformity of egg and prolarval developmental stages.

• Fisheries and Aquatic Sciences
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• 제16권1호
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• pp.15-23
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• 2013

Normal embryonic development at a constant temperature ($18^{\circ}C$) has been described for the Siberian sturgeon Acipenser baerii (Acipenseriformes). Hormone-induced spawning and artificial insemination were performed to prepare embryonic batches for embryologic examination. After insemination, early cleavages of the Siberian sturgeon embryos continued for 7 h post-fertilization (HPF), showing the typical pattern of uneven holoblastic cleavage. Blastulation and gastrulation began at 9 HPF and 19 HPF, respectively. Epiboly formation (2/3 covered) was observed at 25 HPF during gastrulation. Neurulation was initiated with the formation of a slit-like neural groove from the blastopore at 33 HPF. During neurulation, the primary embryonic kidney (pronephros) and s-shaped heart developed. The embryos underwent progressive differentiation, which is typical of Acipenseriform species. A mass hatching was observed at 130 HPF, and the average total length of the hatched prolarvae was 10.5 mm. The hatched prolarvae possessed a typical pigment plug (yolk plug). The results of this study are valuable not only as a reference guide for the artificial propagation of Siberian sturgeon in hatcheries but also as the basis for the derivation of developmental gene expression assays for this species.

• 한국염색가공학회지
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• 제20권4호
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• pp.15-20
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• 2008

The cotton yarn was subjected to bio-polishing treatment with three commercial enzymes(Cellusoft L, Denimax-991L and Denimax-acid) to remove the fuzz on the cotton yarn. Also, enzyme treated cotton yarns were compared with singeing cotton yarns. Experimental variables of enzyme treated cotton yarn were as follow: concentration of enzyme solution and NaOH, dipping time, and processing temperature. The enzymatic treatments were evaluated by analyzing the effect on yarn count, twist contraction, evenness and tenacity. As the results, enzymatic treatment on cotton yarn induced same effects as the traditional singeing treatment. Also, silket treatment of cotton yarn after bio-polishing enhanced the tensile properties of the cotton yarn.

• 대한기계학회논문집 C: 기술과 교육
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• 제5권1호
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• pp.23-52
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• 2017

바이오융합 및 의료기기 산업은 의학과 전기, 전자, 기계, 재료 등 공학이 융합되는 다학제간 응용기술 산업분야이다. 바이오 융합 및 의료기기를 이용해 인간의 삶의 질 향상을 목표로 하고 있으며 제품에 대한 인지도와 브랜드 파워가 매우 중요한 산업이다. 그러나, 자본/기술 의존형 산업으로 제품의 개발부터 생산까지 소요되어지는 기간이 길고 개별 제품의 시장 규모가 작고 수명주기가 짧다고 할 수 있다. 따라서 연구개발에 대한 지속적인 투자가 요구되어지는 산업으로 국가적인 차원에서 바이오벤처 기업들을 위해 기술적 지원, 제도적 뒷받침, 인력 양성 등의 산업생태계 전반을 활성화하고자 하는 노력이 필요하다.

• 한국가구학회지
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• 제25권3호
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• pp.223-232
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• 2014

To make metalized wood composites of 10 different korean wood species, it was tested by Low temperature melting Bi-Sn alloy injection method at high temperature and high pressure condition. Metalized wood composite of each wood species had light ash color, but still maintained its own natural wood grain and wood figures. It was evaluated on coating properties. Furthermore, it also was check on effect of coating as like a changes of main color, wood grain and wood figures. The results of test were following as; a coating properties as like a cold resistance, heat resistance, acid resistance, alkali resistance, durability of abrasion, and cross-cut test was proper on the conditions of the KS standard. And, In aspect of color changes, the metalized wood composites of 10 different korean wood species had a light ash color, but still maintained its own natural wood grain and wood figures. Also, the more weight per gain of alloy is, the more grey background of metalized wood composite is.