• 한국식품과학회지
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• 제45권5호
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• pp.545-549
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• 2013

본 연구에서는 GC-FID를 이용하여 식품첨가물공전에 사용량이 정해져 있는 빵류, 캡슐류, 건조과실류 채소류 및 과실류 채소류 중 유동파라핀의 함량을 측정하였다. 시료에서 n-hexane으로 유동파라핀을 추출하고 $KMnO_4$ 산화반응을 통해 추출물 중 불포화탄화수소의 극성을 증대시킨 다음 aluminium oxide를 충진한 SPE 카트리지로 정제하여 GC-FID로 측정하였다. 검출한계와 정량한계는 각각 10 mg/kg과 20 mg/kg으로 개별 n-alkane으로 정량하는 방법이 아닌 넓은 봉우리로 나타나는 유동파라핀의 면적의 합으로 정량하는 문헌들(15,17)의 값과 유사하게 나타났다. 유동파라핀은 빵류, 건조과실류 채소류 및 캡슐류에서 이형제 등으로 사용되고 있으나 최종 완제품에서 사용기준 이하로 검출되었고, 과실류 채소류에서 모두 불검출로 나타남에 따라 안전한 수준으로 관리되고 있음을 알 수 있었다.

• 한국재료학회지
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• 제30권6호
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• pp.273-278
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• 2020

This research is conducted to analyze the compatibility of used monomers and produce the high functional hydrogel ophthalmic polymer containing silane and nanoparticles. VTMS (vinyltrimethoxysilane), TAVS [Triacetoxy(vinyl)silane] and cobalt oxide nanoparticles are used as additives for the basic combination of SilM (silicone monomer), MMA (methyl methacrylate) and MA (methyl acrylate). Also, the materials are copolymerized with EGDMA (ethylene glycol dimethacrylate) as cross-linking agent, AIBN (thermal polymerization initiator) as the initiator. It is judged that the lenses of all combinations are optically excellent and thus have good compatibility. Measurement of the optical and physical characteristics of the manufactured hydrophilic ophthalmic polymer are different in each case. Especially for TAVS, the addition of cobalt oxide nanoparticles increases the oxygen permeability. These materials are considered to create synergy, so they can be used in functional hydrogel ophthalmic lenses.

• 센서학회지
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• 제25권3호
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• pp.178-183
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• 2016

Semiconductor gas sensors based on metal oxide are widely used in a number of applications, from health and safety to energy efficiency and emission control. Nanomaterials including nanowires, nanorods, and nanoparticles have dominated the research focus in this field owing to their large number of surface sites that facilitate surface reactions. Recently, metal oxide hollow structures using soft templates have been developed owing to their high sensing properties with large-area uniformity. Here, we provide a brief overview of metal oxide hollow structures and their gas-sensing properties from the aspects of template size, morphology, and additives. In addition, a gas-sensing mechanism and perspectives are presented.

• 한국세라믹학회:학술대회논문집
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• 한국세라믹학회 2000년도 추계총회,초청강연,특별강연,연구발표회
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• pp.157.2-157
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• 2000

• Journal of Information Display
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• 제13권3호
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• pp.113-118
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• 2012

Metal oxide semiconductors were considered promising materials as backplanes of future displays. Moreover, the adoption of carrier-suppressing metal into indium-zinc oxide (IZO) has become one of the most important themes in the metal oxide research field. In this paper, efforts to realize and optimize IZO with diverse types of carrier suppressors are summarized. Properties such as the band gap of metal in the oxidized form and its electronegativity were examined to confirm their relationship with the metal's carrier-suppressing ability. It was concluded that those two properties could be used as indicators of the carrier-suppressing ability of a material. As predicted by the properties, the alkali earth metals and early transition metals used in the research effectively suppressed the carrier and optimized the electrical properties of the metal oxide semiconductors. With the carrier-suppressing metals, IZO-based thin-film transistors with high (above $1cm^2/V{\cdot}s$) mobility, a lower than 0.6V/dec sub-threshold gate swing, and an over $3{\times}10^6$ on-to-off current ratio could be achieved.

• 한국세라믹학회지
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• 제20권3호
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• pp.193-198
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• 1983

This experiment has been carried out for the purpose of investigating the effect of $V_2O_5$ and $H_3BO_3$ additives on sintering of magnesium oxide over the temperature range of 1300-150$0^{\circ}C$ MgO powder has been obtained by calcin-ing extra reagent grade magnesium carbonate(basic) at 90$0^{\circ}C$ for 30 minutes. The specimens were prepared by compression with pressure of 700Kg/cm2 then fired at 1300-150$0^{\circ}C$ for 0-5hrs. Sintering behaviour and microstructure of fired specimens were examined. Densification rates obeyed the equation D=K 1n t+C. The ratio of density in case of addition of $V_2O_5$ to theoretical density of pure periclase was 95-99% Activation energy of densification in case of $V_2O_5$ addition was 30.15 Kcal/mole. The range of average grain size in case of addition of $V_2O_5$ was 40-50$\mu\textrm{m}$. $H_3BO_3$ addtivie had not an effect on densification of MgO.

• 한국세라믹학회지
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• 제52권3호
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• pp.180-185
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• 2015

Low-cost ceramic membrane supports with pore sizes in the range of $0.52-0.62{\mu}m$ were successfully prepared by uniaxial dry compaction method using inexpensive raw materials including kaolin, bentonite, talc, sodium borate, and alkaline-earth oxides in carbonate forms (e.g., $MgCO_3$, $CaCO_3$, and $SrCO_3$). The prepared green supports were sintered at $1000^{\circ}C$ for 8 hr in air. The effect of alkaline-earth oxide additives on the flexural strength of clay-based membrane supports was investigated. The porosity of the clay-based membrane supports was found to be in the range of 33-34%. The flexural strength of the clay-based membrane supports with 1% alkaline-earth carbonates was found to be in the range of 42.8-52.7 MPa. The addition of alkaline-earth carbonates to clay-based membrane supports resulted in large increases (47-80%) in the flexural strength of the membrane supports, compared to that of membrane supports without alkaline-earth carbonates. The typical flexural strength of the clay-based membrane support with 1% $SrCO_3$ was 52.7 MPa at 33.8% porosity.

• 한국결정성장학회지
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• 제29권1호
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• pp.1-5
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• 2019

산화물을 포함한 세라믹 재료의 물성은 소재 치밀도에 크게 영향을 받는다. 따라서 소재 치밀도를 높이기 위한 다양한 노력들이 진행되어왔다. 이중 많이 사용되는 전략으로 재료 소결 시 소결조제를 첨가하는 것이다. 기존의 소결조제는 3차원 구조를 갖는 구형의 분말이었다. 본 연구에서는 차별화 전략으로 세륨산화물의 소결 밀도를 높이기 위해 2차원 층상구조를 갖는 소결조제를 첨가하였다. 실제로 2차원 층상구조의 조결조제에 의해 소결밀도가 증가되는 것을 확인할 수 있었다. 2차원 층상구조 소재로 초나노 두께(~1 nm)를 갖는 $TiO_x$와 $MnO_x$ 나노쉬트가 이용되었다.

• 한국조리학회지
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• 제21권1호
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• pp.235-249
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• 2015

저장시간과 저장온도 및 천연첨가제를 달리하여 저장한 표고버섯의 향 변화를 6개의 metal oxide 센서가 장착된 전자코를 이용하여 분석하였다. MA 포장을 한 표고버섯의 품질을 유지하기 위하여 쑥, 약쑥, 녹차와 활성탄의 네 가지 천연첨가제를 사용하였다. 표고버섯은 각 처리구마다 폴리에틸렌 필름으로 포장하였고 5, 10, $20^{\circ}C$에서 저장하였다. 저장온도와 시간이 증가할수록 전자코의 저항비율값과 제1주성분 값이 감소하였는데, 이것은 높은 온도와 저장시간이 길수록 버섯의 품질이 낮아짐을 나타낸다. 표고버섯을 전자코와 주성분 분석(PCA)을 한 결과, 쑥 처리구(B)와 인진쑥 처리구(C)는 $5^{\circ}C$에서, 녹차 처리구(D)와 활성탄 처리구(E)는 $10^{\circ}C$에서 저장할 때 이취발생을 줄이고 선도를 유지하는 효과를 보여주었다. 그러나 $20^{\circ}C$에서는 대조구(A)와 처리구 간의 차이는 없었다.

• 한국초전도저온공학회:학술대회논문집
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• 한국초전도저온공학회 2002년도 학술대회 논문집
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• pp.149-152
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• 2002

SrZrO3 resistive oxide barriers on Ag sheathed Bi2223 tapes prepared by the sol-gel and dip coating method were evaluated with an aid of Taguchi method and orthogonal arrays to elucidate the effects of experimental parameters, such as ratio of starting solution, amount of additives, and heat treatment temperature and time on the properties of the thin films. Six experimental parameters were selected and then Ll8(21x37) orthogonal arrays were constructed. Finally, SEM and XRD results were related to signal to noise (S/N) ratio to evaluate the optimized experimental condition.