• Journal of the Korean Society of Industry Convergence
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• v.2 no.2
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• pp.83-90
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• 1999

A cellulose acetate membrane containing silver nitrate was prepared by gelatinizing in water at $2^{\circ}C$ after evaporating solvent from the casting solution on a glass plate. Permeation experiments for oxygen and nitrogen were conducted in the ranges of temperature, $5-40^{\circ}C$ and pressure difference, $1-5kg/cm^2$ in order to investigate the effects of temperature and pressure difference on permeation characteristics of the membrane. When the evaporation time was increased, the permeability of oxygen decreased but the separation factor of oxygen against nitrogen increased since a more dense layer was formed on the membrane surface. When the silver nitrate was added, the permeation flux was doubled and the separation factor was improved from 3.0 to 3.3. This implies that silver nitrate acts as an oxygen carrier in the membrane.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.9
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• pp.1486-1491
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• 2004

The estrogenicities of six heavy metal compounds, which contaminate frequently in foods, were assayed using a combination of in vitro and in vivo assays. The assays were 1) estrogen receptor dependent transcriptional expression assay, 2) E-screen assay and, 3) the uterotropic assay in mice. The chemicals studied were 17$\beta$ -estradiol, diethylstilbestrol (DES), arsenic oxide, bis(tri-n-butyltin), cadmium chloride, chromium chloride, lead acetate, and mercuric chloride. Using the estrogen receptor dependent transcriptional expression assay, the following estrogenicity ranking was measured: bis(tri-n-butyltin) > cadmium chloride > chromium chloride >> mercuric chloride >lead acetate = arsenic oxide. Using E-screen test, the following estrogenicity ranking was measured: bis(tri-n-butyltin) > cadmium chloride > chromium chloride >> mercuric chloride > lead acetate = arsenic oxide. Results from the uterotropic assay showed that bis(tri-n-butyltin), cadmium chloride, chromium chloride caused an increase in uterine wet weight, while lead acetate, mercuric chloride, and arsenic oxide failed to do so. Bis(tri-n-butyltin), cadmium chloride and chromium chloride showed the highest estrogenicity in three assay systems. Recent studies suggesting that bis(tri-n-butyltin), cadmium chloride have estrogenicities are compatible with the present finding. Furthermore, our study is suggesting that chromium chloride may be estrogenic. The results demonstrate that this three level-assay combination (transcriptional activation, cell proliferation, and an in vivo effect in an estrogen-responsive tissue) could serve as a useful method to assess the estrogenicity of heavy metals.

• Journal of the Korean Chemical Society
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• v.13 no.2
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• pp.141-147
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• 1969

Organophosphorous compounds can be reduced by zinc metal in acidic solution after alkaline hydrolysis. Although phosphates and phosphonates did not evolve any gas, dithioates did evolve hydrogen sulfide and phosphine, thionates and thiolates did evolve only hydrogen sulfide. The evolved gases were qualitatively detected by means of lead acetate and silver nitrate or mercuric bromide papers and determined by spectrophotometrically. The reduction mechanism and analytical method of dithioates were proposed.

• Proceedings of the Korean Magnestics Society Conference
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• 2008.12a
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• pp.48.1-48.1
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• 2008

• Journal of the Korean Society for Precision Engineering
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• v.28 no.11
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• pp.1242-1250
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• 2011

Several biomimetic artificial muscles including the electro-active synthetic polymers (SSEBS, PSMI/PVDF, SPEEK/PVDF, SPSE, XSPSE, PVA/SPTES and SPEI), bio-polymers (Bacterial Cellulose and Cellulose Acetate) and nano-composite (SSEBS-CNF, SSEBS-$C_{60}$, Nafion-$C_{60}$ and PHF-SPEI) actuators are introduced in this paper. Also, some applications of the developed biomimetic actuators are explained including biomimetic robots and biomedical active devices. Present results show that the developed electro-active polymer actuators with high-performance bending actuation can be promising smart materials applicable to diverse applications.

• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2007.06a
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• pp.218-220
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• 2007

유기박막트랜지스터(organic thin film transistor, OTFT)의 게이트 절연막으로 PVP(poly-4-vinylphenol) 물질을 이용하여 MIM (metal-insulator-metal) 구조의 캐패시터 소자를 제작하였다. 유기 절연층의 형성은 ITO/Glass 기판 위에 PVP를 용질로, PGMEA(propylene glycol monomethyl ether acetate)를 용매로 사용하였다. 또한 열경화성 수지인 poly(melamine-co-formaldehyde)를 사용하여 cross-linked PVP 절연막을 합성하여 스핀코팅법으로 소자를 형성하였다. 제작된 소자에 대해 절연막 두께에 따른 전기적 특성을 조사한 결과 300 nm 에서 500 nm로 두께가 증가할수록 누설전류는 10.69 nA 에서 0.1 nA 로 크게 감소하였다. 또한 캐패시터 소자의 정전용량은 300 nm 의 두께에서 1.05 nF 으로 500 nm 의 두께에서의 0.65 nF 과 비교하여 보다 양호한 특성이 나타났다.

• Journal of the Korean Society of Industry Convergence
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• v.13 no.4
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• pp.191-196
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• 2010

This study explores the solution of a variety of conditions of the natural dyeing with the Mulberry. To obtain this, the Cu complex compound was added into the extracts. The Mulberry extract was added the Copper acetate to obtain the Black sediment the metal complex compound of anthocyanidin. According to the result of using the complex compound of the solid material, the dyeing properties were excellent. The metal complex compound acted as a mordant, thus it reduced the process of mordanting in the natural dying.

• Journal of the Semiconductor & Display Technology
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• v.13 no.3
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• pp.13-19
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• 2014

Phosphoric acid was used as etching agent instead of conventional peroxide - based chemicals for forming pattern of ultra definition display. Etchant was synthesized by mixing etching agent, oxidation agent, buffer solution, and additive into solvent, deionized water. Thicknesses of copper, main metal of ultra definition display, for etching, were 10,000 and $30,000{{\AA}}$. Etch stop of good low skew for proper pattern formation has been occurred at the content ratio of phosphoric acid 60 - 64%, nitric acid 4 - 5%, additive(potassium acetate) 1 - 3%. Buffer solution(acetic acid) decreased the metal contact angle $63.07^{\circ}$ to $42.49^{\circ}$ for benefiting pattern formation. Content variations on four components (phosphoric acid, nitric acid, acetic acid, potassium acetic acid) of the etchant with storage time were within 3 wt% after 24 hrs of etching work.

• Bulletin of the Korean Chemical Society
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• v.27 no.10
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• pp.1572-1576
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• 2006

A dimeric precursor, $[Cu(dmae)(OCOCH_3)(H_2O)]_2$ for the CVD of copper metal films, (dmaeH = N,N-dimethylaminoethanol) was synthesized by the reaction of copper(II) acetate monohydrate ($Cu(OCOCH_3)_2{\cdot}H_2O$) and dmaeH in toluene. The product was characterized by m.p. determination, elemental analysis and X-ray crystallography. Molecular structure of $[Cu(dmae)(OCOCH_3)(H_2O)]_2$ shows that a dimeric unit $[Cu(dmae)(OCOCH_3)(H_2O)]_2$ is linked to another through hydrogen bond and it undergoes facile decomposition at 300 C to deposit granular copper metal film under nitrogen atmosphere. The decomposition temperature, thermal behaviour, kinetic parameters, evolved gas pattern of the complex, morphology, and the composition of the film were also investigated.

• Journal of Industrial Technology
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• v.30 no.A
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• pp.37-43
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• 2010

Polymeric materials in addition to Portland cement and hydrated limes were used to solidify heavy metal contaminated tailings from five abandoned metal mines in Korea. Mine tailings were mixed separately with Portland cement and hydrated lime at a concentration of 20-30 wt% and 6-9 wt%, respectively and Ethylene Vinyl Acetate(EVA) powder was added to each specimen at a ratio of 2.5 and 5.0 wt% to binders. Polymer-added and polymer-free solidified forms were evaluated for their appropriateness in accordance with the suggested test methods. Regardless of addition of polymeric materials, all solidified forms satisfy the uniaxial compressive strength(UCS) requirements(0.35MPa) for land reclamation and show remarkably reduced leaching concentrations of heavy metals such as As, Cd, Cu, Pb and Zn less than the toxicity criteria of Korean standard leaching test(KSLT). The addition of polymeric materials increased the UCS of solidified forms to improve a long-term stability of solidified mine tailings.