• 한국염색가공학회:학술대회논문집
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• 한국염색가공학회 2008년도 제38차 학술발표대회
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• pp.135-137
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• 2008

PVA films with 1,2,3,4-Butanetetracarboxylic acid(BTCA) and sodium hypophosphite monohydrate(SHM) were crosslinked via thermal curing. Different parameters affecting on the crosslinking were investigated including BTCA and SHM concentration, curing temperature and time. The cured films was extracted with boiling water and gel fraction was calculated from weight change of the PVA films. Moisture regain of the gelled films was also measured. While the gel fraction of PVA films increased with increasing curing temperature and time, moisture regain decreased. Water resistance of the crosslinked PVA films improved by the BTCA crosslinking treatment.

• Bulletin of the Korean Chemical Society
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• 제33권2호
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• pp.473-482
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• 2012

A novel malemide epoxy containing Co(II), Ni(II) and Cu(II) ions have been synthesized by curing malemide epoxy resin (MIEB-13) and Co(II), Ni(II) and Cu(II) complexes of macrocyclic bis-hydrazone Schiff base. The Schiff base was synthesized by reacting 1,4-dicarbnyl phenyl dihydrazide with 2,6-diformyl-4-methyl phenol. The Schiff base and its Co(II), Ni(II) and Cu(II) complexes have been characterized by elemental analyses, spectral (IR, $^1H$ NMR, UV-vis., FAB mass, ESR), thermal and magnetic data. The curing reaction of maleimide epoxy compound with metal complexes was studied as curing agents. The stability of cured samples was studied by thermo-gravimetric analyses and which have excellent chemical (acid/alkali/solvent) and water absorption resistance. Further, the scanning electron microscopy (SEM) and definitional scanning colorimetric (DSC) techniques were confirmed the phase homogeneity of the cured systems.

• 대한화학회지
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• 제58권2호
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• pp.160-168
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• 2014

The electrochemical behavior and corrosion inhibition of zinc in 0.5 M $H_2SO_4$ in the absence and presence of some chromones has been investigated using weight loss, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and electrochemical frequency modulation (EFM) techniques. The presence of these investigated compounds in the corrosive solutions decrease the weight loss, the corrosion current density, and double layer capacitance but increases the charge transfer resistance. Polarization studies were carried out at room temperature, and showed that all the studied compounds act as mixed type inhibitors with a slight predominance of cathodic character. The effect of temperature on corrosion inhibition has been studied and the thermodynamic activation and adsorption parameters were determined and discussed. The adsorption of the investigated compounds on zinc was found to obey Langmuir adsorption isotherm.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2015년도 제49회 하계 정기학술대회 초록집
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• pp.101.1-101.1
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• 2015

플라즈마에 의한 식각 공정중 챔버 내에서 발생한 오염입자가 기판위에 떨어져 제품의 불량을 일으키고 그에 따른 부품 교체비용이나 교체시 가동을 멈춰야하는 문제점들이 있다. 이러한 문제점을 해결하기 위해 내플라즈마성이 우수하다고 알려진 아노다이징 피막을 사용하고 있다. 하지만 다양한 아노다이징 공법중 어떠한 요인이 내플라즈마 특성과 관계되는지에 대한 보고는 부족한 실정이다. 기존의 아노다이징 특성평가방법으로는 내화학 특성과 열안정성 평가, 구조적 특성을 확인하는 것이 주로 사용되어 왔다. 따라서 본 연구에서는 기존 내화학 특성과 열안정성이 우수하다고 알려진 황산-주석산법을 이용한 피막의 특성을 평가하여 내화학특성, 열적 안정성, 구조적 특성이 내플라즈마 특성과 어떠한 관계가 있는지 확인했다.

• 대한치과의사협회지
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• 제50권9호
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• pp.552-557
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• 2012

Bamboo salt is a special processed salt by Korean traditional recipe. Recent study results showed that bamboo salt or bamboo salt with some other materials like herbal extracts have the anti-microbial activity, inhibition effects of dental plaque and gingival inflammation. Bamboo salt also showed anti-cariogenic effects; remineralization and acid resistance. Compare to fluoride toothpaste, bomboo salt toothpaste with fluoride showed the more effective remineralization on inner part of the early dental caries lesion. It increased the surface hardness and decreased lesion depth of early dental caries lesion. Thus, it is suggested thai bamboo salt could be used as a anti-microbial, anti-plaque, anti-inflammatory and anti-cariogenic material for oral disease prevention. Especially, bamboo salt dentifrice with fluoride can be recommanded as a useful remineralizing agent.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2003년도 춘계학술발표강연 및 논문개요집
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• pp.86-86
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• 2003

Copper has attracted much attention in the deep submicron ULSI metallization process as a replacement for aluminum due to its lower resistivity and higher electromigration resistance. Electroless copper deposition method is appealing because it yields conformal, high quality copper at relatively low cost and a low processing temperature. In this work, it was investigated that effect of the microstructure of the substrate on the electroless deposition. The mechanism of the nucleation and growth of the palladium nuclei during palladium activation was proposed. Electroless copper deposition on TiN barriers using glyoxylic acid as a reducing agent was also investigated to replace toxic formaldehyde. Furthermore, electroless copper deposition on TaN$\sub$x/ barriers was examined at various nitrogen flow rate during TaN$\sub$x/ deposition. Finally, it was investigated that the effect of plasma treatment of as-deposited TaN$\sub$x/ harriers on the electroless copper deposition.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 춘계학술대회 초록집
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• pp.95.1-95.1
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• 2011

In this work, graphene was prepared by modified Hummers method and prepared graphene was applied to electrode materials for supercapacitor. In addition, to enhance the electrochemical performance of graphene, carbon black was deposited onto graphene via chemical reduction. The effect of the carbon black content incorporated on the electrochemical properties of the graphene-based electrodes was investigated. It was found that nano-scaled carbon black aggregates were deposited and dispersed onto the graphene by the chemical reduction of acid treated carbon black and graphite oxide. From the cyclic voltammograms, carbon black-deposited graphene (CB-GR) showed improved electrochemical performance, i.e., current density, quicker response, and better specific capacitance than that of pristine graphene. This indicates that the carbon black deposited onto graphene served as an conductive materials between graphene layers, leading to reducing the contact resistance of graphene and resulted in the increase of the charge transfer between graphene layers by bridge effect.

• Journal of Microbiology and Biotechnology
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• 제21권2호
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• pp.183-186
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• 2011

Biochemical methods were selected to evaluate the role of exopolymeric substances in the stability of biofilms used in bioremediation processes. Biofilms of Thiomonas arsenivorans formed on pozzolana were thus treated with pronase (protein target), lectins (Con A or PNA), calcofluor or periodic acid (polysaccharides target), DNase (DNA target), and lipase (triglycerides target). Neither protease nor DNase treatments had any effect on bacterial adhesion. Lectins and calcofluor treatments mainly affected young biofilms. Lipase treatment had a noticeable effect on biofilm stability whatever the biofilm age. Results suggest that it would be an increased resistance of mature biofilms that protects them from external attacks.

• 한국안전학회지
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• 제25권3호
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• pp.28-33
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• 2010

Ni alloy steel is able to use during long time because of good acid and corrosion resistance. So, it's research has focused on developing the alternative alloy which is economically feasible. Recently, consumption of Kovar steel is gradually increased in field of the jet engine and the gas turbine because of its low thermal expansive characteristics. The specimens of Kovar steel(29%Ni-17%Co) contain 0.00%C, 0.03%C, 0.06%C, 0.10%C and 0.20%C, respectively. Ingots are manufactured by VIM(vacuum induction melting furnace) and then specimens are made by automatic hot rolling after heat treatment. Strength of Kovar steel according to carbon contents is estimated by hardness, tensile and impact test. Hardness of the 0.20%C specimen is more improved approximately 14.4% than one of base metal. Its strength increases 32.4% of a base metal, and its impact energy is also enhance 11.5%.

• 한국응용과학기술학회지
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• 제17권2호
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• pp.144-148
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• 2000

A modification of the sol-gel method to obtain phase pure superconducting oxides is described. The method starts from organic salts of yttrium, barium and copper, such as acetates, and avoids the sudden and uncontrollable decomposition of the organic fraction which occurs if nitrates are used as starting materials. The aqueous solution obtained with citric acid in an alkaline medium is concentrated under vacuum. The solid so prepared is decomposed at about $300^{\circ}C$ thus giving an oxide precursor containing well dispersed yttrium, barium and copper. Pyrolysis at 850 - $920^{\circ}C$ followed by oxygen annealing gives the superconducting orthorhombic 123 phase. The results of TGA/DTA of the precursor, as well as XRD, electrical and magnetic property measurements on the pyrolysis products are presented and discussed.