• 한국전기전자재료학회논문지
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• 제29권12호
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• pp.803-808
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• 2016

In this work, one dimension $In_2O_3$ nanostructures as detecting materials for indoor toxic gases were synthesized by an electrospinning process. The morphology of electrospun $In_2O_3$ nanofibers was controlled by electrolyte composition, applied voltage and working distance between a nozzle and a substrate. The synthesized $In_2O_3$ nanofibers-based paste with/without carbon black additives was prepared for the integration on a sensor device. The integration of $In_2O_3$ sensing materials was conducted by a hand-printing of the paste into the interdigit Au electrodes patterned on Si wafer. Gas sensing properties on CO and HCHO gases were characterized at $300^{\circ}C$. The evaluated sensing properties such as sensitivity, response time and recovery time were improved in $In_2O_3$ nanofiber pastes with carbon black, compared to the paste without carbon black.

• 보존과학회지
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• 제35권4호
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• pp.331-343
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• 2019

The purpose of this study was to investigate the material characteristics of black wares excavated from Yongyeon-ri, Damyang and to clarify the correlation of the factors that develop black coulor compared with black wares excavated from other regions. As a results of absorption rate, colour coordinate, compositional mineral, section analysis and contents showed high correlation between the kilns and the waste dumplings, indicating that they were made using the same materials. Second, comparing the microtextures and contents of the glaze layer with the excavated sherds from other kilns, a characteristic coagulation phenomena of iron oxides were not observed in Yongyeon-ri and Gilmyeong-ri, and it was considered that the material, mixing ratio, and firing environment were different from those of Bonggok-dong. In addition, statistical analysis using the major components revealed that the bodies of Yongyeon-ri were highly correlated with those of Bonggok-dong, which is nearest to the region, and similar to Gilmyeong-ri in the glaze layer. The characteristics of colorant were different depending on Fe₂O₃ content and K₂O content also contributed to the classification of the composition of each excavated kiln. Conclusionally, it can be seen from the scientific analysis that the colour of black wares excluded from different regions is materially different from that of iron oxide, the coloring condition, and the firing environment.

• Nutrition Research and Practice
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• 제13권3호
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• pp.189-195
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• 2019

BACKGROUND/OBJECTIVES: Although aged black garlic has various biological activities such as anti-allergy, anti-inflammation and neuroprotection, effect of aged black garlic on chemically contact dermatitis is unclarified. MATERIALS/METHODS: To evaluate anti-dermatitic activity of aged black garlic extract, we investigated effects of a fraction of aged black garlic extract (BG10) on both in vivo and in vitro. RESULTS: BG10 almost inhibited formation of nitric monoxide and interleukin-6 (IL-6; $IC_{50}$, $7.07{\mu}g/mL$) at $25{\mu}g/mL$, and dose-dependently reduced production of tumor necrosis $factor-{\alpha}$ ($TNF-{\alpha}$; $IC_{50}$, $52.07{\mu}g/mL$) and prostaglandin $E_2$ ($IC_{50}$, $38.46{\mu}g/mL$) in lipopolysaccharide-stimulated RAW264.7 cells. In addition, BG10 significantly inhibited the expression of inducible nitric oxide synthase, cyclooxygenase-2 and nuclear $NF-{\kappa}B$, and improved that of cytosolic levels of $NF-{\kappa}B$ and $I{\kappa}B{\alpha}$ in the cells. Consistent with in vitro studies, BG10 (0.5 mg/mL) not only reduced ear edema but also suppressed the formation of IL-6 and $TNF-{\alpha}$ induced by 12-O-tetradecanoylphorbol-13-acetate in ear tissues of mice. CONCLUSIONS: These findings suggest BG10 has anti-dermatitic activity through inhibiting activation of macrophages. Therefore, such effects of BG10 may provide information for the application of aged black garlic for prevention and therapy of contact dermatitis.

• 보존과학회지
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• 제37권2호
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• pp.77-89
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• 2021

이 연구에서는 울산의 원삼국시대 장현동과 중산동 및 교동리 유적에서 출토된 흑색토기에 대하여 태토의 재료학적 특성과 제작기술을 검토하였다. 흑색토기의 표면은 흑색이지만 속심은 흑색 또는 적황색을 보인다. 현미경 관찰 결과, 태토는 붉은색 철산화물이 풍부한 토양을 사용하였으며 주로 석영과 알칼리 장석 및 운모류가 동정되었고, 부분적으로 미르메카이트 조직의 입자가 관찰된다. 또한 SiO₂와 Fe₂O₃ 및 CaO 함량에서 다소 차이가 있는 것으로 보아, 각 유적지 주변에 분포하는 모암과 태토의 조성이 영향을 준 것으로 판단되며 근거리에서 채토하여 토기를 제작한 것으로 보인다. 라만분광분석 결과, 이 토기의 흑색층에는 비정질 탄소인 연매가 사용되었다. 표면층과 접하는 기질에서는 투명한 갈색의 칠이 관찰되었고 탄소가 농집된 것으로 보아, 흑색층은 연매와 옻을 칠하여 흑색발색을 유도한 것으로 해석된다. 태토의 광물조성과 미세조직으로 볼 때 이 토기의 소성온도는 750~850℃의 범위로 추정되며, 칠은 468℃에서 열분해되었다. 따라서 흑색을 이루는 연매와 칠의 혼합층은 소지의 소성 이후에 칠해진 것으로 판단된다.

• 자원리싸이클링
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• 제27권5호
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• pp.61-68
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• 2018

알루미늄 드로스는 알루미늄 용해 공정에서 용탕 표면에 발생하는 산화물 덩어리로서, Salt 유무에 따라 화이트드로스와 블랙드로스로 구분된다. 화이트드로스의 경우 금속 함량이 높아 용해 공정으로 재활용 되지만, 블랙드로스는 금속 함량이 낮고 성분 분리가 어려워 대부분 매립 처리되며, 물과 반응하면 가스와 발열 반응이 일어나 토양오염의 원인으로 작용한다. 하지만 블랙드로스에는 NaCl과 KCl과 같은 Salt 성분과, $Al_2O_3$, MgO와 같은 무기소재가 포함되어 있어 이러한 유가자원을 회수하고 소재화하는 기술 연구가 필요하다. 본 연구에서는 알루미늄 블랙드로스를 재활용하기 위한 공정을 제시하였다. 파쇄-용해(Dissolution)-고액분리-감압증발을 거치는 공정을 통하여 블랙드로스에 존재하는 무기물과 용해성 물질을 분리하였다. 물과 블랙드로스 함량을 제어하여 조건에 따라 분리물의 회수율을 최적화하였으며, 블랙드로스:물 비율이 1:9 일 때 91 wt.%의 Salt flux 회수율을 보임을 확인하였다. 추가적으로, 회수된 무기물을 이용한 제올라이트의 합성을 통하여 블랙드로스의 소재화 가능성을 확인하였다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.281.2-281.2
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• 2016

Two-dimensional van der Waals (2D vdWs) materials have been extensively studied for future electronics and materials sciences due to their unique properties. Among them, black phosphorous (BP) has shown infinite potential for various device applications because of its high mobility and direct narrow band gap (~0.3 eV). In this work, we demonstrate a few-nm thick BP-based nonvolatile memory devices with an well-known poly(vinylidenefluoride-trifluoroethylene) [P(VDF-TrFE)] ferroelectric polymer gate insulator. Our BP ferroelectric memory devices show the highest linear mobility value of $1159cm^2/Vs$ with a $10^3$ on/off current ratio in our knowledge. Moreover, we successfully fabricate the ferroelectric complementary metal-oxide-semiconductor (CMOS) memory inverter circuits, combined with an n-type $MoS_2$ nanosheet transistor. Our memory CMOS inverter circuits show clear memory properties with a high output voltage memory efficiency of 95%. We thus conclude that the results of our ferroelectric memory devices exhibit promising perspectives for the future of 2D nanoelectronics and material science. More and advanced details will be discussed in the meeting.

• 한국대기환경학회지
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• 제29권2호
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• pp.152-162
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• 2013

The physico-chemical characteristics and nanostructure of the aerosol samples from a coal-fired power plant, a charcoal kiln and diesel vehicles were investigated with focusing on black carbon (BC). Aerosols from the coal-fired power plant were mostly comprised of mineral ash spheres which are heterogeneously mixed. The main components of the aerosols from coal-fired power plant were calcium compounds, iron oxide, alumino-silicate without BC. The typical combustion-generated BC which shows the shape of bunch of grapes with 20~50 nm particles which were detected in aerosol particles from diesel vehicles. The nanostructure of each BC particle shows the shape of concentric circles which is comprised of closely-packed graphene layers. Aerosols from charcoal kiln were likely condensed organic carbon generated from the low-temperature combustion process.

• 한국전기전자재료학회논문지
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• 제25권2호
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• pp.129-134
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• 2012

We analyzed the movement and response time of charged particles according to particle-inserting methods to understand the variation of quantity of q/m of charged particles, which is a very important factor in electrical and optical characteristics of the charged particle type display, such as lifetime, response time, contrast ratio, reflectivity, etc. For our study we used white and black charged particles of which diameter is $20{\mu}m$, prepared pieces of ITO(indium tin oxide) coated glass substrate, and formed ribs on the glass substrates. The width of a rib is $30{\mu}m$ and the cell size is $220{\mu}m{\times}220{\mu}m$. As the particle-inserting methods, the white and black charged particles were respectively inserted into a front and a rear panel with a very small electric field and also the mixture of the white and black charged particles were inserted into a rear panel. As a result of the driving characteristics of charged particles, the factors about variation of quantity of q/m according to the particle inserting method was experimentally demonstrate, showing very different driving voltage, response time, the particle movement, etc.

• 한국분말재료학회지
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• 제11권1호
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• pp.28-33
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• 2004

In the present study, the focus is on the analysis of carbothermal reduction of the titanium-cobalt-oxygen based oxide powder by solid carbon for the optimizing synthesis process of ultra fined TiC/Co composite powder. The titanium-cobalt-oxygen based oxide powder was prepared by the combination of the spray drying and desalting processes using the titanium dioxide powder and cobalt nitrate as the raw materials. The titanium-cobalt-oxygen based oxide powder was mixed with carbon black, and then this mixture was carbothermally reduced under a flowing argon atmosphere. The changes in the phase structure and thermal gravity of the mixture during carbothermal reduction were analysed using XRD and TGA. The synthesized titanium-cobalt-oxygen based oxide powder has a mixture of $TiO_2$ and $CoTiO_3$. This oxide powder was transformed to a mixed state of titanium car-bide and cobalt by solid carbon through four steps of carbothermal reduction steps with increasing temperature; reduction of $CoTiO_3$ to $TiO_2$ and Co, reduction of $TiO_2$, to the magneli phase($Ti_nO_{2n-1}$, n>3), reduction of the mag-neli phase($Ti_nO_{2n-1}$, n>3) to the $Ti_nO_{2n-1}$(2$\leq$n$\leq$3) phases, and reduction and carburization of the $Ti_nO_{2n-1}$(2$\leq$n$\leq$3) phases to titanium carbide.

• 한국결정성장학회지
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• 제27권5호
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• pp.243-248
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• 2017

본 연구에서는 산화주석(IV) 첨가량을 달리하여 동화유약 시편을 제조하고 발색기구를 분석하기 위하여 분광 분석, 결정상 분석, 미세구조 분석을 실시하여 색상과의 상관성을 분석하였다. 산화주석(VI) 첨가량이 증가함에 따라 동화유약의 붉은색은 사라지고 CIEab 값이 감소하여 무채색으로 발색하였다. 산화주석은 유약층에 고르게 분포하여 Cu nuclei가 성장하여 붉은색으로 발색하는 것을 방해하고 기포 주변의 metal Cu와 반응하여 합금을 형성하였다. 이로 인해 산화주석 첨가량이 증가함에 따라 금속 Cu 피크는 사라지고 미세한 $Cu_2O$ 피크만 남게 된다. 산화주석을 3.79 % 첨가하였을 때는 유약에 붉은색을 내는 $Cu_2O$보다 검정색을 나타내는 CuO와 Cassiterite $SnO_2$가 색상에 더 영향을 미치는 것으로 보여진다.