• Polymer(Korea)
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• v.27 no.2
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• pp.159-166
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• 2003

For the purpose of obtaining surface-anionized poly(vinyl alcohol) (PVA) hydrogel beads, vinyl acetate(VAc) and methacrylic acid(MMA) were copolymerized by the suspension polymerization technique and followed by the saponification. It was confirmed by $^1$H-NMR that the copolymerized microspheres contained carboxylic acid groups in their surface. poly(VAc-co-MAA) microspheres were completely saponified in the heterogeneous system. The saponification reaction was laster than that of PVAc microspheres. We observed the swelling property of saponified PVA microspheres treated in the acidic solution and in the alkaline solution successively. Saponified microspheres shrank in acidic solution and swelled in alkaline solution respectively, which was reversible. from the result, saponified microspheres were highly water-absorbing hydrogel beads and were certified -COOH group at their surface by $^1$H-NMR and FT-IR.

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 2004.10a
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• pp.380-383
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• 2004

본 연구는 원유에서 지방을 제거한 탈지유의 pH를 5.5, 7.0, 8.5로 조정한 다음 TGase를 첨가하여 0, 1, 2, 4, 8시간 반응시킨 다음 단백질 입자들을 동결건조하여 조직의 성상에 대해 주사 전자 현미경을 이용해 관찰, 비교하였다. pH와 TGase를 처리하지 않은 원유의 탈지유는 단백질 입자들이 규칙적으로 회합해 있었다. 그러나 pH 조정 후 TGase를 처리한 다음 반응시간을 달리한 시료에서는 pH를 5.5로 조정한 시료에서 현저한 변화가 있었는데 그 변화 양상은 단백질 입자들이 0시간에서 조각을 이루워 회합되어 있다가 1시간 반응시킨 경우 단백질 입자들이 서로 결합하여 넓게 회합을 하였다. 2시간 반응시킨 경우 단백질 입자들이 다시 뭉쳐서 회합하였으며 4시간 반응시킨 경우 뭉쳐져 있던 단백질 입자들이 조그만한 구형 성상으로 넓게 회합하였다. 8시간 반응시킨 시료는 구형 성상으로 회합되어 있던 단백질 입자들이 사라지면서 다시 넓게 회합하는 것을 관찰할 수 있었다. pH 7.0과 8.5 조건하에서는 단백질 입자들이 조각 형태를 이루고 있었으며 반응시간이 증가할수록 입자들이 넓게 확대되는 현상을 나타냈다. 이와 같은 단백질들의 변화 양상은 pH와 TGase처리 그리고 반응시간에 영향을 받고 있는 것으로 사료된다.

• Journal of Adhesion and Interface
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• v.18 no.1
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• pp.13-24
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• 2017

In this study, nanoparticles which encapsulated hydrophobic antimicrobial compounds with 50wt% of payload and 70%of solid content were prepared. These nanoparticles could be dispersed at water as well as various medium. Water dispersible organic-inorganic (O-I) hybrid nanoparticles were first prepared using alkoxysilane-functionalized amphiphilic polymer precursors through a conventional sol-gel process. Hydrophobic antimicrobial compound, Eugenol encapsulated nanoparticles were prepared using these O-I hybrid nanoparticles through a new nanoprecipitation process. The effect of various preparation on the size of nanoparticles, amount of payload, antimicrobial activity, and release rate of encapsulated compounds was investigated. All eugenol-encapsulated O-I nanoparticles regardless of preparation condition showed the same minimal inhibitory concentration (MIC) (50mg/ml) and 99% of antimicrobial activity for every strain. Their antimicrobial activity could maintain longer than two weeks. Especially, eugenol-encapsulated O-I nanoparticles prepared using tetraethoxysilane (TEOS) exhibited the highest payload (50wt%) and the lowest release rate which was owing to higher inorganic content in the O-I nanoparticles. And these O-I nanoparticles dispersed in hexanediol (HD) showed the highest antimicrobial activity and solid content (70wt%) because HD acted as a solvent as well as a antimicrobial agent.

• Composites Research
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• v.27 no.3
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• pp.109-114
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• 2014

Manufacture of nancomposites has simple process for developing nanocomposites due to the increasing applications using nanofillers. This work studied nanofiller coated glass fiber for reinforcing material with good wetting and conductivity and the morphology of nanofiller coated glass fiber was analyzed by FE-SEM. The durability of reinforced glass fiber was investigated with different shapes of nanofillers using sonication rinsing method. Fatigue test was performed to evaluate the adhesion of reinforcing interface and stability of nanofiller coating layer for single fiber reinforced composites. Apparent modulus and conductivity of nanofiller coating layer were evaluated to realize multifunctional of nanocomposites. Fiber type of nanofiller was better than plate type due to better cohesion between fiber and nanofillers. At last, the stability of fiber type nanofiller of coating layer has better durability and conductivity than plate type case.

• Korean Chemical Engineering Research
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• v.50 no.4
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• pp.654-658
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• 2012

In this study, $CO_2$ capture efficiency in relation to the inlet moisture content of the regenerator was investigated using potassium-based sorbents in the continuous process composed of two bubbling fluidized-bed reactors, where solid outlet configuration in the regenerator was converted from underflow to overflow. XRD (X-ray Diffraction), SEM (Scanning Electron Microscope) and TGA were performed to find out the effect of water pre-treatment according to inlet moisture content in the regenerator. The $K_2CO_3{\cdot}1.5H_2O$ structure of solid sorbents has been increased as inlet moisture content of the regenerator increased. As a result, the $CO_2$ capture efficiency increased as the $K_2CO_3{\cdot}1.5H_2O$ structure of solid sorbents increased since the reactivity of the sorbents has been improved by that structure generated by the water pre-treatment. And $CO_2$ capture efficiency increased about 3~8% after sorbent outlet configuration of the regenerator was changed underflow to overflow.

• The Journal of Dong Guk Oriental Medicine
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• v.6 no.2
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• pp.87-98
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• 1998

Renal tissues of ICR mouse were intraperitoneally injeced with Monostroma nitidum extract(ME) after Triton WR-1339(TX) injection were observed to investigate the lipid accumulation suppressive effect of ME. The renal tissues were obtained at hour 24, 48, and 72 after TX injection that were fixed in fromol-calcium solution and were cryocut. The tissue stained by H&E for general morphology, sudan black B for lipid and perchloric acid-naphthoquinone method for cholesterol. The parietal layer of Bowman's capsule is swatted as cuboidal type at hour 48 after TX injection and the lipid blot and cholesterol particle were noticeably increased in glomerulus than control group and these appeared in convoluted tubule, collecting tubule, and Helen's loop. But the parietal layer of Bowman's capsule was shaped as squamous type that was looked like as normal morphology in ME treated group after TX injection and the lipid blot and cholesterol particle were considerably decreased in glomerulus than TX group. As results indicated that the accumulation of lipid including cholesterol caused by TX injection were mitigated in renal tissues by the antihyperlipidermic effect of ME.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2003.05a
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• pp.391-396
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• 2003

정류상태하에서의 WINFLOW 모델에 의한 모의발생 결과치는 산정된 계산치와 관측치의 오차백분율(0.011~0.080의 범위)를 비교해 볼 때 지하수두 분포를 신뢰도 수준에 있어 잘 반영하고 있는 것으로 판단되며 동서방향으로는 일정 수두분포, 남북방향으로는 완만하고 안정된 수두경사를 이루는 것으로 분석되었다. 분석유역에서의 지하수 유동은 남측에서 하천지역으로 안정된 유동형태를 보이고 있으며, 각 지점에 대한 입자추적은 상류에서 양수지점까지 비교적 직선에 가까운 형태를 보이고 있으나 양수지점의 하류부에서는 양수량의 크기에 따라 영향반경도 많은 차이를 나타내었다. P 및 Pl관정의 동시 양수인 경우에는 P지점 또는 Pl지점의 단일정일 경우보다 영향반경의 크기가 증가한 것 보다는 다소 복잡해진 양상을 보였으며 입자경로는 직선에 가까운 형태를 가지는 것으로 분석되었다. 양수량에 따른 영향원을 살펴보면 지하수가 남측에서 북측(병성천)으로 유동할 경우에 상류부보다 관정 측면과 하류부에서 더욱 크게 지하수두가 감소하는 변화경향을 나타내어 지하수유동방향 및 유속이 관정의 영향원 분포에 많은 영향을 미치고 있음을 알 수 있었다.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.1
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• pp.102-102
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• 2012

타이탄의 근적외선 영역 스펙트럼에서 나타나는 특유의 넓은 흡수밴드를 고체 탄화수소화합물과 질소화합물의 조합으로 설명하고자 한다. 이 흡수 밴드는 대기권의 하층부에 존재하는 연무(haze)에 의한 것으로, 3.3 - 3.4 micron 부근과 2.30 - 2.35 micron 부근에서 유사한 형태가 발견됐다. 두 파장대 모두 C-H 스트레칭 모드가 존재하는 영역이라는 공통점이 있으며, 그 형태가 넓은 흡수밴드로 나타나므로 대기 중에 고체상태의 탄화수소화합물이 존재하는 것으로 유추할 수 있으며, 관련 분자들의 실험값과 복사전달모델을 이용하여 이를 설명하고자 한다. 또한, 이 흡수밴드는 고도에 따라 그 형태와 세기가 달라지므로, 연무 입자들의 고도에 따른 수직분포 및 크기 등을 파악할 수 있다. 이 연구에서는 기존에 타이탄에서 발견된 $CH_4$, $C_2H_6$, $CH_3CN$의 고체 분광선과, 해당 영역에서 흡수선을 보이는 $C_5H_{12}$, $C_6H_{12}$, $C_6H_{14}$ 등의 고체 분광선을 이용한 모델을 Cassini 탐사선의 VIMS 관측자료로부터 유도한 파장 및 고도에 따른 광학적 깊이 변화량과 비교하여 보여주고자 한다.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.9 no.6
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• pp.127-132
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• 2000

Morphological analysis of wear particles is one of useful methods for machine condition monitoring because it is well reflected in machine driving state. This paper was undertaken to apply to the condition monitoring of hydraulic piston motor. The lubricating wear test was performed under different experimental conditions using the wear test device and wear specimens of the pin on disk type was rubbed in paraffinic base oil by three kinds of lubricating materials, varying applied load, sliding distance. The four shape parameters(50% volumetric diameter, aspect, roundness and reflectivity) are used for morphological analysis of wear particles. The results showed that the four shape parameters of wear particles depend on a kind of the lubricating materials. It was capable of calculating presumed wear volume for three kinds of materials on driving time to foresee as damage condition of lubricating materials.

• Korean Chemical Engineering Research
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• v.50 no.5
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• pp.795-801
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• 2012

Nanoparticles have received significant attention because of their unusual characteristics including high surface area to volume ratios. Thiol ligand have been used as stabilizers of metal nanoparticles since Brust et al. They reported the preparation method of ligand capped metal nanoparticles by protecting the nanoparticles with a self-assembled monolayer of dodecanethiolate. In this method, volatile organic compounds (VOCs) were used as sovents. This study was carried out to replace these VOCs with room temperature ionic liquids (RTILs). We used two type of ILs to prepare metal nanoparticles. One is a hydrophobic IL, [BMIM][[$PF_6$] (1-Butyl-3-methylimidazolium hexafluorophosphate) purchased from IL maker, C-Tri from Korea and the other one is a hydrophilic one, [BMIM][Cl] (1-Buthy-3-methylimdazolium chloride) sinthesized by us. In the case of preparing Ag and Au nanoparticles using [BMIM][Cl], we didn't use phase transition reagents and ethanol because it has hydrophilic property and preparing Au, Ag nanoparticles using [BMIM][[$PF_6$] the method is as same as Brust et al.'s except using [BMIM][[$PF_6$] instead of organic solvent because it has hydrophobic property. FT-IR and UV-vis, TEM, TGA analysis have been used in an attempt to determine the particle size and verify functional groups. The particle size obtained from TEM was very similar to those obtained by Brust et al. This is a clear example of ligand capped metal nanoparticles prepared using ionic liquids. And the experimental result demonstrated ionic liquids can act as a highly effective medium for the preparation and stabilization of gold and silver metal nanoparticles.