• Journal of the Korean Vacuum Society
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• v.10 no.1
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• pp.61-66
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• 2001

$WO_3$ films were multicoated on the microscope slide glass and ITO-coated glass using a tungsten alkoxide type solution by the sol-gel deposition process. The effect of dipping and processing parameters on the structure, optical and electrochemical properties of the film were also investigated. Coating using alkoxide solution was very uniformed for low dipping speed of 0.005 m/s, but thickness variations across the sample became apparent for dipping speeds greater than 0.007 m/s. Electrochemical coloration experiments showed that films fired at lower temperatures color more easily than film fired to > $200^{\circ}C$. Rutherford backscattering spectroscopy studies revealed that $K^+$ ions were uniformly distributed throughout the $WO_3$layer in the colored sample.

• Journal of Oral Medicine and Pain
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• v.38 no.2
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• pp.109-114
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• 2013

Chemical burn on the oral mucosa is caused by contact with various chemical products and manifests with localized mucositis, keratotic white lesions, bleeding, and painful tissue surface due to the coagulation of the tissue. Policresulen ($Albothyl^{(R)}$) is a topical antiseptic, commonly used over-the-counter drug for vaginitis, thrush and stomatitis. This drug is highly acidic with pH 0.6, and can act as a strong corrosive agent to oral mucosa. When inadvertently used in oral cavity, it may cause chemical burns of oral mucosa, resulting necrosis and bleeding surface resembling to erythema multifome. A 56 years old female patient presented with the chief complaints of painful ulcerations on the tongue, the upper and lower lips. On intraoral examination, an erythromatous, erosive or ulcerative surface covered with inflammatory exudates or bleeding crust is observed on the anterior half of the tongue and the upper and lower lips. She has occasionally applied the policresulen solution topically on the tongue to relieve pain from recurrent focal glossitis for about 10 years. In this time she applied it broadly and repeatedly to the tongue, the upper and lower lips for the purpose of pain relief by herself without instruction by physician or dentist. After cessation of policresulen application, the oral mucosa was rapidly recovered with use of topical steroids. In 2 weeks the lesions subsided completely. In summary, inadvertent use of $Albothyl^{(R)}$ on oral mucosa may result in chemical burn, causing mucosal erosion, ulceration and inflammation. It can be recovered by topical use of corticosteroid for 2 weeks after cessation of using $Albothyl^{(R)}$.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.412-412
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• 2011

CI(G)S계 태양전지는 화합물 반도체로서, 우수한 광 전류 변환 효율을 보이며, 광조사 등에 의한 열화가 없어 유망한 태양전지로 인정받고 있다. CI(G)S계 태양전지를 구성하는 흡수층을 제조하는 방법은 진공 기반의 공증착법 및 스퍼터-셀렌화법이 대표적이며, 액상의 전구체 물질을 도포하고 이를 고온 열처리하는 용액공정법도 최근 많은 연구가 이루어지고 있다. 진공 증착법은 고효율의 흡수층을 제조할 수 있고 상용화에 적합한 방법이다. 그러나 고가의 진공 장비를 이용하는 진공증착법은 원가 절감 관점에서 한계를 지니고 있어, 미래의 저가 공정 실현을 위해 용액 기반 흡수층 제조법도 다양한 접근법으로 연구되고 있으며 현재까지는 진공공정에 비해 상대적으로 낮은 변환효율이 큰 문제점으로 인식되고 있다. 용액 공정에서 전구체 물질의 코팅법으로는 spray법, spin coating법, drop-casting법, doctor-blade법 등이 있으며, 이들 중 양산 공정에 실용화되기 가장 적합한 것으로 보이는 방법으로는, 화합물 나노입자 페이스트를 기재 상에 doctor blade 법으로 코팅한 후에 이를 열처리하여 흡수층을 제조하는 방법을 들 수 있다. 이러한 방법은 균일한 흡수층을 저비용으로 제조할 수 있는 장점은 있지만, 전구체로 사용하는 화합물 나노입자들이 화학적 및 열적으로 매우 안정한 물질이므로, 최종 흡수층에서 큰 결정을 얻기 어렵고, 그 결과 효율이 낮아지는 단점이 있다. 따라서, 치밀하고 조대한 grain 형성을 위하여 CISe 균일한 나노입자를 합성하고 셀레늄을 포함하는 용액을 추가로 도포하여 열처리 공정에서 Se의 손실을 막아 입자를 성장시키는 방법과 In-Se 균일한 나노입자를 합성한 후 Cu, Se이 포함된 용액을 도포하여 코어-쉘 (InSe/CuSe)을 제작하고 이를 Se 분위기하 열처리 하여 흡수층의 결정성을 증진시키고자 하였다. 또한 다양한 방법으로 제작한 CuInSe2 나노입자로 잉크를 제작하여 닥터블레이드 공정을 적용하여 박막을 제작하고 소자 적용성을 평가하였다.

• Proceedings of the Materials Research Society of Korea Conference
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• 2011.10a
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• pp.29.2-29.2
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• 2011

수용액 상에서 유기물이나 무기물의 전해산화에는 높은 산소과전압과 그 화학종에 대한 화학적, 물리적 안정성이 요구되며, 이러한 요구 조건을 만족하는 소재로써 백금족의 원소가 통상 사용되고 있으나, 가격이 매우 비싸다는 단점을 가지고 있다. 특히 고전류밀도 폐수처리 불용성 전극은 수용액을 전기분해할 때 높은 전류밀도를 낼 수 있으며, 폐수에 혼합되어 있는 각종 화학적 성분에 대한 화학적, 물리적 내구성이 있는 전극으로서, 현재 기존의 수처리용 전극은 금속 Ti을 기판으로 하여 그 위에 불용성 촉매로써 전도성 금속염을 도포, 열처리를 반복하여 산화물의 형태로 수 ${\mu}m$의 두께로 코팅하는 이른바, DSA (Dimensionally Stable Anodes) 전극을 사용하고 있는데, 이는 제조 단가의 상승과 금속 Ti 기판 상에 코팅된 전도성 금속산화물의 미약한 접착력으로 인한 탈리로 전극 전체의 성능 저하 및 수명 단축을 초래하는 문제점이 있다. 본 연구에서는 상기의 문제점을 개선하고자 대표적 불용성 촉매 물질인 백금을 RF magnetron 스퍼터링방식으로 100~300 nm 두께로 성막하여 Ti 기판에 대한 불용성 촉매 물질의 부착력과 내구성 및 모의 해수에 대한 해수전해 특성 등을 평가하였다.

• Polymer(Korea)
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• v.38 no.6
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• pp.809-814
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• 2014

An array structure of conducting polymer microtubule was fabricated for an amperometric biosensor. 3,4-Ethylenedioxythiophene (EDOT) was electropolymerized in the microporous template membrane with poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonic acid) (PEDOT/PSS) composite as a binder. The array structure can provide enhanced current collecting capability due to large active surface area compared to the macroscopic area of the electrode itself. For a biosensor application, the array electrode was tested for $H_2O_2$ detection and showed very sluggish electrochemical response to $H_2O_2$. To enhance the detection efficiency to the oxidation of $H_2O_2$, gold was treated on the electrode by two different approaches: sputtering and electrochemical deposition. Gold treatment with either method greatly enhanced the sensitivity of the electrode to $H_2O_2$. So, conducting polymer microtubule array with gold treatment was expected to be a sensitive amperometric biosensor system based on the detection of $H_2O_2$.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.7
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• pp.102-108
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• 2013

In manufacturing of solution-processed organic electronic devices, a spin coating method is frequently used, but which has a big problem. Solvent in a solution has a decisive effect such as physical and chemical damage for successive solution-based film deposition. Such a severe damage by solvent restricts for fabricating building blocks of multi-layered films from solutions. In this work, it will be shown that a proper combination of well-known solvents gives a chance to fabricate multi-layered film, also this new method was applied to make organic field effect transistor. Two types of bottom gate, bottom contact transistors were fabricated, one of which is fabricated by conventional single spin coating method, the other fabricated by double spin coating method. Compared with the electrical characteristics in a single spin coated transistor, the leakage current between source and gate electrode was decreased, ON state current was increased, and the extracted saturation mobility was multiplied more than 2.7 time for double spin coated transistors. It is suggested that the multiple coated gate dielectric structure is more desirable for high performance organic ferroelectric field effect transistors.

• Journal of the Korean Applied Science and Technology
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• v.38 no.3
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• pp.700-707
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• 2021

This study aimed to understand the effects of apricot kernel oil on the improvement of hair texture by producing a hair texture improvement agent added with apricot kernel oil and then applying it to damaged hair. In the test method and measurement, the agent was produced by putting different contents of apricot kernel oil like 0 g, 1 g 2 g, and 3 g. After applying the produced agent to bleached sample hair, it was heat treated and then left as it was. The comparative analysis was conducted by measuring each sample before and after application. To understand its effects on the improvement of hair texture, the tensile strength, absorbance with the use of methylene blue, and gloss were measured. In the results of this study, the tensile strength was increased in every sample except for healthy hair after application. In the results of analyzing the absorbance with the use of methylene blue, it was decreased in samples like 7L(1), 7L(2), 7L(3), and 9L(3) after application. In the results of measuring the gloss, it was increased in the samples like 7L(1), 7L(2), 7L(3), and 9L(3). Such changes in the tensile strength, absorbance, and gloss showed the effects of apricot kernel oil on the texture improvement of damaged hair. In the future, it would be necessary to have researches on various methods of measurement and treatment.

• Applied Chemistry for Engineering
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• v.7 no.6
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• pp.1078-1086
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• 1996

The peroxo-polytungstic acid was formed by the direct reaction of tungsten powder with the hydrogen peroxide solution. Peroxo-polytungstic powder were prepared by rotary evaporator using the fabricated on to ITO coated glass as substrate by dip-coating method using $2g/10mL(W-IPA/H_2O)$ sol solution. A substrate was dipped into the sol solution and after a meniscus had settled, the substrate was withdrawn at a constant rate of the 3mm/sec. Thicker layer could be built up by repeated dipping/post-treatment 15 times cycles. The layers dried at the temperature of $65{\sim}70^{\circ}C$ during the withdrawn process, and then tungsten oxides thin film was formed by final heating treatment at the temperature of $230{\sim}240^{\circ}C$ for 30min. A linear rotation between the thickness of thin film and the number of dipping/post-treatment cycles for tungsten oxides thin films made by dip-coating was found. The thickness of thin film had $60{\AA}$ after one dipping. From the patterns of XRD, the structure of tungsten oxides thin film identified as amorphous one and from the photographs of SEM, the defects and the moderate cracks were observed on the tungsten oxides thin film, but the homogeneous surface of thin films were mostly appeared. The electrochemical characteristic of the $ITO/WO_3$ thin film electrode were confirmed by the cyclic voltammetry and the cathodic Tafel polaization method. The coloring bleaching processes were clearly repeated up to several hundreds cycles by multiple cyclic voltammetry, but the dissolved phenomenon of thin film revealed in $H_2SO_4$ solution was observed due to the decrease of the current densities. The diffusion coefficient was calculated from irreversible Randles-Sevick equation from the data obtained by the cyclic voltammetry with various scan rates.

• Journal of Dental Rehabilitation and Applied Science
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• v.36 no.1
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• pp.55-60
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• 2020

The aim of this study was to investigate the change of microbial contamination levels in the different areas and at the different time points after application of a quaternary ammonium compound (QAC) that has mechanical antimicrobial effect. The microbial contamination levels were measured in three different areas; unit chair handle, spit sink area and hand piece holder at different time points using adenosine triphosphate (ATP) monitoring system and ATP surface test kit. Hand piece holder showed the highest level of microbial contamination. In most of the clinics, QAC significantly reduced the levels of microbial contamination, and maintained antimicrobial activity for 4 to 6 months. QAC may be used effectively in dental clinics due to the duration of antimicrobial effect and the minimal exposure of chemicals and further studies are needed with large sample size.

• Korean Journal Plant Pathology
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• v.12 no.2
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• pp.219-255
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• 1996

사과 겹무늬썩음병의 주 전염원은 가지 병반에서 형성되는 자낭포자 및 병포자이므로, 가지에서의 포자형성 또는 포자의 분산을 화학적 또는 물리적 방법으로 저해할 수만 있다면 효과적으로 병을 방제할 수 있을 것으로 생각했다. 전염원을 줄이기 위한 첫 번째 시도로 1992년 이른봄 가지에 형성된 사마귀를 호미로 제거한 결과, 병포자의 분산과 과실발병 억제효과에 있어서 무처리와 유의적인 차이가 인정되지 않았다. 두 번째 시도로 포자의 분산을 막기 위해 1993년 이른봄에 겹무늬썩음병에 걸린 가지를 비닐필름으로 감고 5월부터 9월까지 20일 간격으로 살균제를 살포한 결과, 통계적으로 유의성이 인정되는 병 방제효과가 있었고, 나무의 생육에 있어서도 콜크층이 이상 비대하는 것 이외에 별다른 이상이 없었다. 이 개념을 더욱 발전시켜 1994년 이른봄에는 병든 가지를 수용성 고분자 물질인 polyvinyl alcohol로 도포하고 수배 분산 포자의 수를 조사한 결과, 포자의 분산량이 크게 줄어져 실용화의 가능성이 시사되었다.