• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2012년도 춘계학술발표대회 논문집
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• pp.364-369
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• 2012

The development of solar thermal energy used adsorption desalination technology have been examined as a viable option for supplying clean energy. In this study, the modelling of the main devices for solar thermal energy used and adsorption desalination system was introduced. Silica gel type adsorption desalination system is considered to be a promising low-temperature heat utilization system. The design is divided into three parts. First, the evaporator for the vaporization of the tap water is designed, and then the reactor for the adsorption and release of the steam is designed, followed by the condenser for the condensation of the fresh water is designed. In addition, new features based on the energy balance are also included to design absorption desalination system. In this basic research, One-bed(reactor) adsorption desalination plant that employ a low-temperature solar thermal energy was proposed and experimentally studied. The specific water yield is measured experimentally with respect to the time controlling parameters such as heat source temperatures, coolant temperatures, system switching and half-cycle operational times. Desalination is processes that permeate our daily lives, but It requires substantial energy input, powered either from electricity or from thermal input. From the environmental and sustainability perspecives, innovative thermodynamic cycles are needed to produce the above-mentioned useful effects at a lower specific energy input. This article describes the development of adsorption cycles for the production of desalting effects. We want that this adsorption system can be driven by low temperature heat sources at 60 to $80^{\circ}C$, such as renewable, solar thermal energy.

• 한국식품영양학회지
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• 제10권2호
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• pp.208-212
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• 1997

까치복(Fugu xanthopterus) 알을 총지질 함량과 silica gel column chromatography로 조성별 분획하여 얻은 TG, 인지질, wax ester의 지방산과 wax ester의 알코올 조성을 GC로 분석하였다. 까치복 알의 총지질 함량은 12.6%였고 알 지질의 분획별 함량에서는 TG가 59.37%로 가장 많았고 인지질이 15.46%였으며 wax ester가 6.9%로 나타났다. 까치복 알의 지방산 조성은 각 분획마다 DHA의 함량이 높게 나타났으며 DPA, EPA의 함량도 높았음을 알 수 있었고 인지질 분획에서는 DHA가 19.3%로 가장 높게 나타났다. 포화 지방산, 모노 불포화 지방산, 고도 불포화 지방산의 함량은 각각 35.3, 27.4, 37.3%로 고도 불포화 지방산의 함량이 높게 나타났음을 알 수 있었다. 한편 까치복 알의 wax ester의 지방산 분획에서는 포화 지방산, 모노 불포화 지방산, 고도 불포화 지방산이 5.8, 47.0, 47.4%로 나타났는데, 알코올 분획에서는 C16:0가 62.6%로 높은 함량을 나타내어 포화 알코올이 86.3%로 가장 많았음을 알 수 있었으며 고도 불포화 알코올은 1.2%의 아주 낮은 함량을 보인 것이 특징적이었다.

• 한국세라믹학회지
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• 제51권3호
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• pp.177-183
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• 2014

Alumina-silica composite coating layers were prepared by electrophoretic deposition (EPD) of plate-shaped alumina particles dispersed in a sol-gel binder, which was prepared by hydrolysis and the condensation reaction of methyltrimethoxysilane in the presence of colloidal silica. The microstructure and the electrical and thermal properties of the coatings were compared according to the EPD process parameter: voltage, time and the content of the plate-shaped alumina particles. The electrical insulation property of the coatings was measured by a voltage test. The coatings were prepared by EPD of the sol-gel binder with 5-30 wt% plate alumina particles on parallel electrodes at a distance of 2 cm for 1-10 min under an applied voltage of 10-30 V. The coatings experienced increased breakdown voltage with increasing thickness. However, the higher the thickness was, the smaller the breakdown voltage strength was. A breakdown voltage as high as 4.6 kV was observed with a $400{\mu}m$ thickness, and a breakdown voltage strength as high as 27 kV/mm was achieved for the sample under a $100{\mu}m$ thickness.

• 한국식품영양과학회지
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• 제32권7호
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• pp.1059-1065
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• 2003

우리나라 야산에서 손쉽게 구할 수 있는 구황식물인 목단피를 건조시켜 분쇄한 후 methanol과 여러 용매로 추출하여 식품 부패 미생물의 증식 억제 효과를 검색하고 그 항균물질을 분석하여 다음과 같은 결과를 얻었다. 목단피의 methanol 추출물은 1500$\mu\textrm{g}$/mL 농도에서 B. subtilis, L. monocytogenes, V parahaemolyticus의 증식을 100% 억제하였으며 S. aureus, E. coli도 같은 농도에서 각각 36.31%와 67.81%의 억제 효과를 보였다. 목단피의 ethylacetate 분획 추출물은 낮은 농도인 500$\mu\textrm{g}$/disc의 농도에서 식품 부패 미생물 5종 모두에 대하여 clear zone을 형성하여 항균력을 나타내었다. 특히 L. monocytogenes, E. coli균에 대해서는 낮은 농도인 500$\mu\textrm{g}$/disc에서 각각 12mm, 11mm의 clear zone을 형성하였다. 목단피의 ethylacetate추출물을 silica gel colum chromatography(7cm${\times}$1.2 cm)한 후 thin layer chromatography(TLC)를 실시하여 항균 실험을 한 결과 B. subtilis의 경우 500 $\mu\textrm{g}$/disc 농도에서 2nd fra. 1이 21mm, V. parahaemolyticus는 250$\mu\textrm{g}$/disc 농도에서 14mm를 형성하여 목단피의 methanol 추출물로부터 각 용매별로 계통 분획하여 분리한 ethylacetate 분획으로부터 silica gel column chromatograpy와 TLC를 하여 항균성을 보인 2nd fra. 1의 성분을 알아보기 위하여 HPLC로 단일분리하여 얻은 peak Ⅸ에 대한 compound를 GC-MS로 분석한 결과 peak Ⅸ에서는 isobutyl isopentanoate가 있는 것으로 추정되었다.

• Applied Biological Chemistry
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• 제49권4호
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• pp.339-342
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• 2006

칸나의 뿌리를 80% MeOH용액으로 추출하고, 얻어진 추출물을 EtOAc, n-BuOH 및 물로 용매 분획 하였다. 이 중 EtOAc 분획과 n-BuOH 분획으로부터 silica gel과 octadecyl silica gel(ODS) column chromatography로 정제하여 4종의 화합물을 분리하였다. 각 화합물의 화학구조는 NHR, MS 및 IR 등의 스펙트럼 데이터를 해석하여, $\beta$-sitosterol(1), linoleic aicd methyl ester(2), monoglycosyldiglyceride(3), daucosterol(4)으로 동정하였다. 이 화합물들은 칸나에서 처음으로 분리되었다.

• 한국식품과학회지
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• 제28권2호
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• pp.360-365
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• 1996

벼(Oryza sativa L.)의 가식부인 쌀의 brassinosteroid 활성물질의 존재를 구명하기 위하여 벼를 도정하여 미강과 백미를 얻고 이들을 각각 MeOH로 추출하여 얻어진 추출물을 rice inclination test의 생물검정법으로 검정한 결과 활성이 인정되었다. 각각의 추출물을 생물검정법을 지표로 용매분획, silica gel adsorption chromatography, Sephadex LH-20 column chromatography, charcoal adsorption chromatography 등의 수법으로 brassinosteroid 활성물질을 정제하고, silica gel adsorption chromatography, TLC 등에 의해 활성본체를 분리하고 각 활성획분을 HPLC에 의해 활성본체 구명을 시도한 결과 미강의 활성획분에서는 castasterone과 teasterone이 동정되었다. 완숙된 쌀에서 brassinosteroid 활성물질의 확인 및 동정은 본 연구가 최초로 생각되며, brassinosteroid 활성물질은 주로 미강에 존재하였으며, 그 함량은 g중량당 castasterone이 0.15 ng 이고 teasterone은 0.37 ng 수준이었다.

• 전기화학회지
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• 제8권2호
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• pp.77-81
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• 2005

전기화학적으로 이온을 흡착시켜 이온을 제거하는 capacitive deionization(CDI)공정용 전극으로 탄소에어로젤에 실리카젤이 첨가된 다공성 탄소에어로젤 복합전극을 사용하여 1,000ppm NaCl수용액에서 탈염 특성에 대한 충전과 방전시 시간에 따른 전류 변화, CDI효율을 조사하였다. Paste rolling법으로 제조된 $10\times10cm^2$다공성 탄소에어로젤 복합전극은 촉매 분야에서 활용되고 있는 다공성 지지체인 실리카젤을 첨가함으로써 CDI 반응진행에 대한 전극활물질 탈락이 없이 전극의 성형성이 크게 향상되었고, 친수성과 전극의 기계적 강도 증가 및 CDI 효율을 증가시킬 수 있었다. 이러한 45개의 전극을 하나의 묶음으로 네 개의 단을 직렬연결 하여, CDI 시스템을 구성하였고 충전 시에는 1.2V, 방전 시에는 0.001V를 각각 10분간 인가하여 실험한 결과 $99\%$ 이상의 CDI 효율을 달성하였다.

• Nuclear Engineering and Technology
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• 제54권10호
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• pp.3641-3649
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• 2022

A simple solvothermal reaction was used to prepare a 3-aminopropyl-functionalized silica-gel-based adsorbent for adsorbing Pd(II) from the nitric acid solution. Scanning electron microscopy, fourier transform infrared spectroscopy, and thermogravimetry analysis were performed on the as-synthesized adsorbent to demonstrate the successful introduction of Schiff base groups. Batch experiments were used to investigate the effects of contact time, nitric acid concentration, solution temperature, and adsorption capacity. It is worth noting that the prepared adsorbent exhibited a higher affinity toward Pd(II) with the uptake approximately 100% even in a 2 M HNO₃ solution. At an equilibrium time of 5 h, the maximum adsorption capacity of Pd(II) was estimated to be 0.452 mmol/g. The adsorbed Pd(II) could be completely eluted by dissolving 0.2 M thiourea solution in 0.1 M HNO₃. Using a combination of particle-induced X-ray emission analysis and an X-ray photoelectron spectrometer, the adsorbed Pd was found to be uniformly distributed on the surface of the prepared adsorbent and the existing species were Pd(II) and zero-valent Pd(0). Due to the desirable performances, facile preparation method, and abundant raw material source, the prepared adsorbent demonstrated a high application potential in the recovery of Pd(II) from simulated high-level liquid waste treatment.

• Nuclear Engineering and Technology
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• 제55권9호
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• pp.3441-3449
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• 2023

We determined the radiation shielding properties for 10CaO-xPbO-(90-x) deteriorated silica gel (DSG) glass system (x = 20, 25, 30, 35, 40, and 45 mol.%). The mass attenuation coefficient (MAC) has been estimated at photon energies of 74.23, 97.12, 122, 662, 1173, and 1332 keV using a narrow beam X-ray attenuation and transmission experiment, the XCOM program, and a PHITS simulation. The obtained MAC values were applied to estimate the half value layer (HVL), mean free path (MFP), effective atomic number, and effective electron density. Results show that the MAC value of the studied glasses ranges between 0.0549 and 1.4415 cm²/g, increases with the amount of PbO, and decreases with increasing photon energy. The HVL and MFP values decrease with increasing PbO content and increase with increasing photon energy. The recycled glass, with the addition of PbO content (20-45 mol.%), exhibited excellent radiation shielding capabilities compared to standard barite and ferrite concretes and some glass systems. Moreover, the experimental radiation shielding parameters agree with the XCOM and PHITS values. This study suggests that this new waste-recycled glass is an effective and cost-saving candidate for X-ray and gamma-ray shielding applications.

• 한국재료학회지
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• 제33권7호
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• pp.265-272
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• 2023

In this study, the synthesis of nitrobenzene was carried out using sulfated silica catalyst. The study delved into H₂SO₄/SiO₂ as a solid acid catalyst and the effect of its weight variation, as well as the use of a microwave batch reactor in the synthesis of nitrobenzene. SiO₂ was prepared using the sol-gel method from TEOS precursor. The formed gel was then refluxed with methanol and calcined at a temperature of 600 ℃. SiO₂ with a 200-mesh size was impregnated with 98 % H₂SO₄ by mixing for 1 h. The resulting 33 % (w/w) H₂SO₄/SiO₂ catalyst was separated by centrifugation, dried, and calcined at 600 ℃. The catalyst was then used as a solid acid catalyst in the synthesis of nitrobenzene. The weights of catalyst used were 0.5; 1; and 1.5 grams. The synthesis of nitrobenzene was carried out with a 1:3 ratio of benzene to nitric acid in a microwave batch reactor at 60 ℃ for 5 h. The resulting nitrobenzene liquid was analyzed using GC-MS to determine the selectivity of the catalyst. Likewise, the use of a microwave batch reactor was found to be appropriate and successful for the synthesis of nitrobenzene. The thermal energy produced by the microwave batch reactor was efficient enough to be used for the nitration reaction. Reactivity and selectivity tests demonstrated that 1 g of H₂SO₄/SiO₂ could generate an average benzene conversion of 40.33 %.