• 한국분말재료학회지
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• 제29권6호
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• pp.499-504
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• 2022

The objective of this study is to assess the impact of spray drying conditions on medium-chain triglyceride (MCT) loading, solubility, and release of an MCT-loaded solid self-emulsifying system in a water-insoluble oily substance. MCT-loaded solid self-emulsifying systems are prepared by spray drying with SDS and calcium silicate. The effects of inlet temperature (60, 80, or 100℃) and feed solution composition (0, 10, 50, 90, or 100% ethanol) on physicochemical properties of MCT-loaded solid self-emulsifying systems are studied. The inlet temperature significantly affects the water solubility of MCT. Moreover, the feed solution composition significantly affects water solubility, release rate, and MCT loading. The MCT-loaded solid self-emulsifying system obtained at 60℃ using 90% ethanol feed solution shows the best physicochemical properties among the synthesized products and exhibits better water solubility (4.43 ± 0.44 vs. 0 ㎍/mL) and release (94.4 ± 1.6 vs. 32.8 ± 7.4%, 60 min) than a commercial product. Furthermore, the MCT-loaded solid self-emulsifying system shows an excellent emulsion droplet size (approximately 230 nm).

• 한국토양비료학회지
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• 제48권1호
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• pp.22-29
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• 2015

The objectives of this study were to monitor the changes in soil solution nutrients and to evaluate their effect on rice uptake and yield. The changes of chemical characteristics of paddy soil solution were examined from the 58th fertilization experiment in which the continuous rice cropping experiment started in 1954 at the National Academy of Agricultural Science. The treatments were no fertilization (No fert.), inorganic fertilization (NPK), inorganic fertilizer plus rice straw compost (NPKC) and inorganic fertilizer plus silicate and lime fertilizer as a soil amendment (NPKCLS). The fertilizers were added at rates of standard fertilizer application rate in which nitrogen (N), phosphate ($P_2O_5$), potassium ($K_2O$), and sililcate ($SiO_2$) were applied at rates of $75{\sim}150kg\;ha^{-1}$, $70{\sim}86kg\;ha^{-1}$, $75{\sim}86kg\;ha^{-1}$, and $7.5Mg\;ha^{-1}$ respectively and lime was applied to neutralize soil acidity until 6.5. Average Electrical Conductivity (EC) of soil solution in NPKCLS and NPKC ranged from 1.16 to $2.00dS\;m^{-1}$. The $NH{_4}^+$ and $K^+$ levels in NPKCLS and NPKC were higher than that of the other treatments, due to high supply power of rice straw compost. The content of $H_3SiO{_4}^-$ was higher in NPKCLS because of silicate application. The dominant ions in soil solution were $Ca^{2+}$, $Mg^{2+}$ and $Na^+$ among cations and $HCO{_3}^-$, $SO{_4}^{2-}$, and $Cl^-$ among anions in all treatments. The continuous application of inorganic fertilizers plus rice straw compost (NPKC) and silicate fertilizer (NPKCLS) led to the changes of various chemical composition in soil solutions. Also, they had a significant impact on the improvement of rice inorganic uptake and grain yield. Especially, inorganic uptake by rice in NPKC and NPKCLS significantly increased than those in NPK plot; 14~46% for T-N, 32~36% for P, 43~57% for K, and 45~77% for Si. Therefore, the combined application of inorganic fertilizers with organic compost as a soil amendment is considered as the best fertilization practice in the continuous rice cropping for the improvement of crop productivity and soil fertility.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2003년도 추계학술발표대회 논문집
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• pp.21-24
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• 2003

In general, to enhance physical properties of PET-layered silicate nanocomposites $(P_{et}LSNs)$, it has been well known that the organic modifiers should introduce into gallery regions. However, the organic modifiers in$(P_{et}LSNs)$ may result in thermal decomposition by melt processing at high temperature, and it necessarily lead to deteriorate various physical properties of final products. Therefore, in this study, $(P_{et}LSNs)$ excluding and including organic modifiers were prepared by solution method $(S-P_{et}LSNs_{eom} and S-P_{et}LSNs_{iom})$ and we (focused on the effects of the organic modifiers in $P_{et}$ LSNs with exfoliation structure on the crystallization behaviors, the optical transparency, the thermal stability and the mechanical property. The absence and existence of organic modifiers in $S-P_{et}LSNs_{eom} and S-P_{et}LSNs_{iom}$ were investigated by EA and TGA, and nano-structure of silicate layers in $S-P_{et}LSNs$ was evaluated by using WXRD, SAXS and TEM. $S-P_{et}LSNs_{eom} and S-P_{et}LSNs_{iom}$ were mixed with neat PET as masterbatches by melt method $(M-P_{et}LSNs_{eom} and M-P_{et}LSNs_{iom})$, and also neat PET was mixed with organically modified layered silicates (OLS) by conventional direct melt method $(D-P_{et}LSNs) at 270^{\circ}C$. As results, it was found that $M-P_{et}LSNs_{eom}, M-P_{et}LSNs_{iom}, and D-P_{et}LSN$ showed a exfoliated structure and exhibited faster crystallization rate, better thermal stability and mechanical property than those of neat PET due to the dispersed and detaminated silicate layers in PET matrix. Whereas, considering organic modifiers effect, $M-P_{et}LSNs_{eom} and D-P_{et}LSN$ exhibited slower crystallization rate, poorer optical, thermal and mechanical properties, in comparison to $M-P_{et}LSNs_{eom}> due to the thermal decomposition of organic modifier in $D-P_{et}LSNs$ during melt method.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2019년도 추계학술대회
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• pp.46-46
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• 2019

The experiments were performed in the Jinan (elevation: 300 meters above sea level), Jeollabuk-do. Seedlings (n = 63 per $3.3m^2$) of ginseng cultivar (Cheonpung, Yeonpung) were planted on April 10, 2015. Shading material of plastic film house was blue-white film. Before the Planting seedling, silicate (3 kg/10 a) or chitosan (40 kg/10 a) was fertilized and foliar sprayed on the leaves 1000 times dilution solution once a month from May to September every year. The growth results of 5-year old ginseng surveyed in 2018 are as follows. The average air temperature in the plastic film house was the highest at $26.6^{\circ}C$ and $26.5^{\circ}C$ in July and August, respectively, and the highest temperature was $40.5^{\circ}C$ in July. The maximum daily temperature of $35^{\circ}C$ or more was 30 days, with the average soil temperature being $24.9^{\circ}C$ in August. The chemical properties of the test soil are as follows. pH was 6.4~6.9 level and EC was 0.35~0.46 dS/m. The organic matter content was 33.5~41.4 g/kg, and available-P content was 251.9~306.8 mg/kg. Exchangeable cations contents, such as K, Ca and Mg were all the appropriate ranges. The soil microbial density surveyed by the dilution plate method was 10~50 times higher than that of control (Non-treatment) and actinomycete density was 3~6 times higher. Pathogens of the genus Fusarium by Metagenome analysis decreased 91.3% and 68.2% respectively in the foliar sprayed of chitosan and soluble-silicate. The light intensity (PAR) in the blue-white film plastic film house gradually increased until July and then decereased, with the average of light intensity in March-October was $120.3umol/m^2/s$. The growth of aerial parts such as plant height and stem length was better than non-sprayed group in silicate or chitosan treatments and Yeonpung cultivar was superior to the Cheonpung cultivar. The SPAD value was higher in Yeonpung cultivar foliar sprayed with soluble-silicate. The growth of underground parts such as root length and taproot length were better in chitosan and soluble-silicate treatment than control, especially in Yeonpung cultivar foliar sprayed with chitosan was good in taproot length and taproot diameter, and fresh weight of root was 60.1 g. Ginsenoside contents were 24.9 mg/g and 22.4 mg/g, in the Cheonpung cultivar foliar sprayed with soluble-silicate or chitosan respectively, 28% and 15% higher than control (19.5 mg/g). The incidence of disease by Alteraria panax and Botrytis cinerea was 3~9% and 4~9%, respectively. High temperature damage rate was 3~5%.

• 농약과학회지
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• 제4권2호
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• pp.37-43
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• 2000

본 시험은 오이 양액재배시 배양액내 규산칼륨($K_{2}SiO_{3}$) 처리에 의한 흰가루병 방제여부를 검토하기 위하여 규산 칼륨($K_{2}SiO_{3}$, $25{\sim}27%$의 $SiO_{2}$ Kanto)을 0.85 mM(50 $mg{\cdot}L-^{-1}$), 1.7 mM(100 $mg{\cdot}L-^{-1}$) 및 3.4 mM(200 $mg{\cdot}L-^{-1}$)의 농도로 배양액에 처리하고 1.7 mM, 8.5 mM, 17 mM 및 34 mM의 농도로 엽면살포하였다. 생육중기(정식 51일)에 규산 3.4 mM 배양액 처리구는 흰가루병 병반면적율이 2.3%로 0.95 mM 처리구의 38.3%에 비해 현저히 억제되었다. 그러나 1.7 mM과 3.4 mM 처리간에는 현저한 차이가 없었다. 배양액내 규산의 농도를 0.05 mM에서 4.10 mM까지 증가시켰을 때 잎당 병반수, 병반면적 및 발아관 길이는 규산의 농도 증가에 따라 감소하였다. 규산을 처리한 잎에서의 분생포자 발아율은 처리농도가 높아질수록 현저하게 감소하였으며, 저농도 처리구(1.40 mM 이하)에서는 $14.7%{\sim}20.3%$, 고농도처리구(1.85 mM 이상)에서는 $9.0%{\sim}12.4%$였다. 2% 물한천 배지에서의 농도시험에서는 발아율이 $1.1%{\sim}2.0%$로 일정한 경향을 나타내지 않았다. 규산칼륨을 17 mM의 농도로 희석하여 엽면살포한 결과 무처리에 비하여 흰가루병 발생이 현저히 억제되었으며, 방제효과 지속기간은 병원균 접종후 4일까지였다.

• 한국세라믹학회:학술대회논문집
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• 한국세라믹학회 2000년도 춘계총회,특별강연,심포지움,연구발표회
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• pp.20.1-20.1
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• 2000

• 폴리머
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• 제25권5호
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• pp.691-698
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• 2001

에폭시 (diglycidyl ether of bisphenol A: DGEBA), 경화제 (dicyandiamide; DICY), 촉매 (benzyl dimethyl amine : BDMA), 그리고 유기치환된 실리케이트 (organically modified mica type silicate: OMTS)를 용융법 및 용액법을 이용해 나노복합체를 제조하였고, $170^{\circ}C$에서 시간에 따라 경화 반응을 진행하면서 X선 회절분석기 (XRD)와 소각 X선 산란장치 (SAXS)를 이용하여 구조 변화를 관찰하였다. 용융법으로 제조된 치료의 경우 박리된 구조를 관찰할 수 없었으나 용액법에 의해 제조된 경우 박리된 구조를 관찰할 수 있었다. 이는 OMTS 층 내ㆍ외부의 경화 속도차이 때문인 것으로 생각된다. 박리된 에폭시 나노복합체의 OMTS 첨가량에 따른 기계적 물성을 동적기계적 분석기 (DMA)를 이용해 측정한 결과 OMTS의 첨가량이 증가할수록 모둘러스는 증가하였으나 유리전이온도는 큰 차이가 없었다. OMTS 첨가량에 따른 열적 성질을 열중량분석기(TGA)와 한계산소지수 (LOI)를 이용해 측정한 결과 OMTS양이 증가할수록 OMTS 판의 차단효과로 인해 열분해 시작 온도와 LOI 값이 증가하였다.

• 한국세라믹학회지
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• 제55권6호
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• pp.527-555
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• 2018

High-temperature thermal insulation materials challenge extensive oxide candidates such as porus $SiO_2$, $Al_2O_3$, yttria-stabilized zirconia, and mullite, due to the needs of good mechanical, thermal, and chemical reliabilities at high temperatures simultaneously. Recently, porous rare earth (RE) silicates have been revealed to be excellent thermal insulators in harsh environments. These materials display attractive properties, including high porosity, moderately high compressive strength, low processing shrinkage (near-net-shaping), and very low thermal conductivity. The current critical challenge is to balance the excellent thermal insulation property (extremely high porosity) with their good mechanical properties, especially at high temperatures. Herein, we review the recent developments in processing techniques to achieve extremely high porosity and multiscale strengthening strategy, including solid solution strengthening and fiber reinforcement methods, for enhancing the mechanical properties of porous RE silicate ceramics. Highly porous RE silicates are highlighted as emerging high-temperature thermal insulators for extreme environments.

• 공업화학
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• 제30권5호
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• pp.562-568
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• 2019

Cylindrical shape extrudates of calcium silicate hydrate (CSH) were prepared using different percentages of polyvinyl alcohol (PVA) / sodium alginate (SA) mixtures as binders and an aqueous solution containing 6% $H_3BO_3$ and 3% $CaCl_2$ was used as a cross linking agent. As the quantity of alginate increases, the phosphate removal efficiency and capacity were decreased. Among four different extrudate samples, the sample prepared by 8% PVA + 2% SA showed the highest phosphate removal efficiency (59.59%) and capacity (29.97 mg/g) at an initial phosphate concentration of 100 ppm and 2.0 g/L adsorbent dosage. Effects of the adsorbent dosage, contact time and initial phosphate concentration on the sample were further studied. The removal efficiency and capacity obtained by a 4.0 g/L adsorbent dose at an initial phosphate concentration of 100 ppm in 3 h were 79.38% and 19.96 mg/g, respectively. The experimental data of kinetic and isotherm measurements followed the pseudo-second-order kinetic equation and Langmuir isotherm model, respectively. These results suggested that the phosphate removal was processed via a chemisorption and a monolayer coverage of phosphate anions was on the CSH surface. The maximum adsorption capacity ($q_{max}$) was calculated as 23.87 mg/g from Langmuir isotherm model.

• 청정기술
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• 제12권3호
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• pp.171-174
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• 2006

본 연구진이 개발한 적니응집제를 제조하는 과정에서 발생하는 침출슬러지를 재활용하여 중금속이온 제거용 흡착제를 제조하였다. 침출슬러지 10 g에 kaolin 1 g, sodium silicate solution 2 g을 혼합하여 펠�� 형태로 성형한 후 $600^{\circ}C$에서 2시간 동안 열처리하여 흡착제를 제조하였다. 회분식 흡착실험을 한 결과, 본 연구에서 제조된 흡착제는 $Pb^{2+}$ 이온에 대하여 우수한 흡착성능을 가졌다.