• Bulletin of the Korean Chemical Society
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• 제33권12호
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• pp.3987-3992
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• 2012

Silver nanopowders were prepared from silver 2-ethylhexylcarbamate (Ag-EHCB) complexes by simple thermal reduction at $85^{\circ}C$ without any reducing agent in organic solvent. 2-Ethylhexylammonium 2-ethylhexylcarbamate (EHAEHC) was investigated in terms of their abilities to stabilize the silver nanoparticles (Ag-NPs) and its subsequent effects on the preventing aggregation between Ag-NPs. Conditions (concentration of stabilizer and reaction time) used to reduce Ag-EHCB complex were systematically varied to determine their effects on the sizes of Ag-NPs. The formation of the stabilized Ag-NPs were easily monitored by UV-vis spectroscopy and characterized by TGA, TEM, SEM and XRD. When EHAEHC was used as a stabilizer, Ag-NPs of 10-30 nm in diameter were easily obtained in high yield. Silver patterns were obtained from a silver nano-paste by heat treatment at $200^{\circ}C$ in air and were found to have resistivity values of $2.9{\times}10^{-8}\;{\Omega}{\cdot}m$.

• 한국폐기물자원순환학회지
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• 제35권8호
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• pp.744-753
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• 2018

The Stockholm Convention, which was adopted in Sweden in 2001 to protect human health and the environment, includes regulations for Persistent Organic Pollutant Rotors such as toxic and bioaccumulatives. Currently, there are 28 types of materials. This prohibits and limits the production, use, and manufacture of products. Korea is a member of the Convention, and it is necessary to prepare management and treatment plans to address the POP trends. Thus, we experimentally investigate whether the environmentally stable incineration is achieved when the sample is thermally treated using the Lab-scale (1 kg/hr). The target samples is pesticides in liquid phase and solid phase. In this study, organic chlorinated pesticides and their thermal characteristics were analyzed. We calculated the theoretical air volume based on the element analysis results. Because the interior of the reactor is small, more than 10 times of the air ratio was injected. The retention time was set to at least 4 seconds using a margin. The incineration temperature was $850^{\circ}C$ and $1100^{\circ}C$. Thus, we experimentally investigated whether the environmentally stable incineration was achieved when the sample was thermally treated using the Lab-scale (1 kg/hr). We analyzed five types of exhaust gas; the 02 concentration was high, but the CO amount decreased. Complete combustion is difficult because of the small size of the furnace due to the nature of Lab-scale. The organic chlorine-containing pesticide had an average decomposition rate of 99.9935%. Considering the decomposition rates of organic chlorine-containing pesticide in this study, the incineration treatment at over 2 ton/hour, which is typical for a conventional incinerator, is possible. Considering the occurrence of dioxins and unintentional persistent organic pollutants, it can operate at more than $1,100^{\circ}C$.

• 한국지하수토양환경학회지:지하수토양환경
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• 제17권3호
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• pp.76-85
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• 2012

Geochemical and ecological properties of remediated soil and gas exhausted from a low-temperature thermal desorption (LTTD) process were analyzed to assess the environmental impact of LTTD treatment. Soil characteristics were examined with regard to the chemical (EC, CEC, and organic matter) and the ecological (dehydrogenase activity, germination rate of Brassica juncea, and growth of Eisenia andrei) properties. The exhaust gases were analyzed based on the Air Quality Act in Korea as well as volatile organic compounds (VOCs) and mixed odor. Level of organic Organic matter of the soil treated by LTTD process was slightly decreased compared to that of the original soil because the heating temperature ($200^{\circ}C$) and retention time (less than 15 minutes) were neither high nor long enough for the oxidation of organic matter. The LTTD process results in reducing TPH of the contaminated soil from $5,133{\pm}508$ mg/kg to $272{\pm}107$ mg/kg while preserving soil properties. Analysis results of the exhaust gases from the LTTD process satisfied discharge standard of Air Quality Law in Korea. Concentration of VOCs including acetaldehyde, propionaldehyde, butyraldehyde and valeraldehyde in circulation gas volatilized from contaminated soil were effectively reduced in the regenerative thermal oxidizer and all satisfied the legal standards. Showing ecologically improved properties of contaminated soil after LTTD process and environmentally tolerable impact of the exhaust gas, LTTD treatment of TPH-contaminated soil is an environmentally acceptable technology.

• 한국재료학회지
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• 제25권6호
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• pp.274-278
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• 2015

The possibility of using the chemical precipitation method of up-cycled ammonium paratungstate (APT) was studied and compared with the thermal decomposition method. $WO_3$ particles were synthesized by chemical precipitation method using a 1:2 weight ratio of APT: Di-water. For thermal decomposition, APT powder was heated for 4h at $600^{\circ}C$ in air atmosphere. The reaction products were characterized by X-ray diffraction (XRD), X-ray fluorescence spectrometer (XRF), particle size analyzer (PSA), and field emission-scanning electron microscopy (FE-SEM). Thermogravimetric analysis (TGA) of the up-cycled APT allowed for the identification of the sequence of decomposition and reduction reactions that occurred during the heat treatment. TGA data indicated a total weight loss of 10.78% with the reactions completed in $658^{\circ}C$. The XRD results showed that APT completely decomposed to $WO_3$ by thermal decomposition and chemical precipitation. The particle size of the synthesized $WO_3$ powders by thermal decomposition with 2 h of planetary milling was around $2{\mu}m$ During the chemical precipitation process, the particle size of the synthesized $WO_3$ powders showed a round-shape with ${\sim}0.6{\mu}m$ size.

• 생물환경조절학회지
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• 제25권4호
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• pp.302-307
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• 2016

동절기에 공정육묘장에서 난방 에너지 절감과 우량묘 생산을 위해 나노탄소섬유적외선 난방등(NCFIHL, nano-carbon fiber infrared heating lamp)의 적정 전력과 설치높이를 구명하는 것이 본 연구의 목적이다. 벤로형 유리온실 내부에 수박 접목묘를 재배하기 위해 700과 900W NCFIHL을 육묘 베드($1.2{\times}2.4m$)에서 0.7, 1.0, 및 1.3m 높이로 각각 설치하였다. 수박(Citrullus lanatus (Thunb.) Manst.) '지존꿀'과 박(Lagenaria leucantha Rusby.) '선봉장'은 각각 접수와 대목으로 사용되었다. 접수와 대목은 편엽합접 방식으로 접목되었다. NCFIHL의 광도는 모든 처리에서 $1{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ 이하였다. NCFIHL의 광분포는 대부분 적외선 영역에서 나타났다. 외기온도가 $10^{\circ}C$ 이하일 때 700과 900W NCFIHL을 0.7m 높이로 설치한 처리구와 900W NCFIHL을 1.0m 높이로 설치한 처리에서 야간 설정온도($20^{\circ}C$)를 유지하였다. 열화상 촬영에서는 900W NCFIHL을 0.7m 높이로 설치한 처리에서 가장 빨리 식물체의 온도가 올라갔다. Compactness는 700W NCFIHL을 1.3m 높이로 설치한 처리에서 우수하였다. 결과적으로 700W NCFIHL을 1.0m 이상으로 설치하는 것이 바람직하다고 판단된다.

• 한국식품영양과학회지
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• 제20권6호
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• pp.609-614
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• 1991

고추의 효율적인 이용의 한 방안으로서 고추 oleoresin을 제조하여 품질 및 저장 안정성에 대하여 실험하였다. 고추 oleoresin을 제조하여 품질 및 저장 안정성에 대하여 실험하였다. 고추 oleoresin중 carotenoid의 열안정성은 외기가 질소로 치환된 조건에서 매우 안정하였으며, 가열온도 $100^{\circ}C$에서 3시간 및 10시간 가열 후의 잔존율은 대기중에서는 각각 61.9% 및 42.3%였고 질소 존재하에서는 각각 95.4% 및 92.3%였다. 또한 capsaicin의 경우는 열안정성이 비교적 높아 $100^{\circ}C$에서 3시간 및 10시간 가열할 때의 잔존율은 대기중에서는 84.7% 및 81.3%였고, 질소로 치환된 조건에서는 90.7% 및 87.5%였다. 저장온도($5^{\circ}C,\;25^{\circ}C\;및\;40^{\circ}C$)에 따른 색도의 변화는 Hunter scale로써 나타낼 경우 L 및 b값은 저장일수의 경과에 따라 다소 증가하였으나 적색도인 a값은 약간 감소하였으며 저장온도가 높을수록 증감의 변화가 다소 컸다. 각 저장온도에서의 carotenoid 파괴는 1차반응에 따랐으며 이 저장온도 범위에서의 활성화에너지는 5.03Kcal/mole이었으며, carotenoid의 잔존율은 저장 60일 후 각각 69.4%, 48.0% 및 35.1%로 저장중 다소 불안정 하였으나, carotenoid의 경우는 각 저장온도에서 60일 후 91.2~97.1%의 높은 잔존율을 나타내어 매우 안정하였다. 저장중 pH의 변화는 저장 60일 동안 $5^{\circ}C$ 저장의 경우는 거의 없었으며 저장온도가 높을수록 pH는 다소 증가하였다.

• 한국표면공학회지
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• 제41권2호
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• pp.63-68
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• 2008

Traditionally and generally used calcined clay was carburized, and its characteristics were studied. Carburization treatment was performed by the thermally decomposed carbon and the deposit carbon which occur in a so called 'Boudouard reaction $(2CO{\rightarrow}CO_2+C)'$ at fuel combustion process in a closed-type furnace. The color of the carburized calcine clay changed from yellow to black, and the carbon component revealed as crystalline graphite by the X-ray diffraction test. The weight of the carburized calcine clay decreased to about 4 wt.% by the 1st heating to $1400^{\circ}C$ in air but it does not decreased by the 2nd heating of the same conditions. By the carburization treatment, the water absorption changed from 13 wt.% to 6 wt.%, and the contact angle for water drop changed, too, from 0 to $87^{\circ}$ which was tested by the photograph of one minute after a water drop contact. It means the carburized calcine clay does not absorb water drop so it has a hydrophobic characteristic.

• 한국식품저장유통학회지
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• 제21권5호
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• pp.652-660
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• 2014

수확 후 매실의 미생물학적 안전성 확보를 위해 0.5% citric acid와 0.1% Tween 20 단일 및 병합 처리 후 $4{\pm}1^{\circ}C$에서 7일간 저장하면서 미생물 수 및 품질 변화를 조사하였다. Citric acid와 Tween 20 병합 처리 후 총 호기성 세균과 효모 및 곰팡이 수는 대조구와 비교하여 각각 2.06, 2.22 log CFU/g으로 가장 높은 감소 효과를 보였으며, 이러한 효과는 저장 7일 동안 유지되었다. 매실의 유기산 함량을 분석한 결과, malic acid, citric acid, oxalic acid의 순서로 높은 함량을 나타냈고, 모든 처리구에서 유의적인 차이가 없었으며, 저장 중 색도 역시 큰 차이를 보이지 않았다. 또한 매실의 저장성 증진 및 다양한 매실 가공품 제조를 위한 기초연구로써 탈수제를 이용한 건조 후 건조 매실의 품질 변화를 열품건조와 비교, 분석하였다. 탈수제 처리 건조가 열풍건조에 비해 높은 복원율을 나타냈고, 총 페놀 및 플라보노이드 함량 역시 열풍건조 보다 많았으며, 대조구와 유사한 함량을 유지하였다. 또한 건조 매실의 색도에 있어서도 탈수제 처리가 부정적 영향을 끼치지 않는 것으로 나타났다. 따라서 본 연구결과, 수확 후 매실에 citric acid와 Tween 20 병합 처리가 미생물학적 안전성을 확보함과 동시에 품질 변화를 일으키지 않는 효과적인 가공 전처리 기술이라고 생각되며, 탈수제 처리가 건조 매실의 품질을 높게 유지하며 저장성을 높일 수 있는 효율적인 건조 방법이라고 판단된다.

• 생물환경조절학회지
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• 제13권4호
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• pp.251-257
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• 2004

본 연구는 몇가지 보온피복 재료 및 방법이 플라스틱하우스의 보온력과 토마토의 생육과 수량에 미치는 영향을 구명하고자 수행하였다. 다겹보온덮개(카시미론 8온스 1겹+폴리폼(1 mm) 4겹 +부직포 2겹+폴리프로필렌 1겹+흑색네트차광망 1겹)를 이중하우스 구조의 외면에 피복한 것이 이중하우스 구조의 내부에 피복한 것에 비해 하우스내 야간의 기온과 지온은 약 $ 낮았으나 광투과율이 높아서 토마토 상품수량이 약 $2\%$ 증가하였다. 그리고 다곁보온덮개를 피복하지 않고 이중하우스 구조의 내부에 EVA커튼을 설치한 것에 비해서는 하우스내 야간기온이 $3^{\circ}C$ 높게 유지되어 수확기가 약 1일 빨라지고 토마토 과실도$ 19\%$ 증수하였다. 한편 이중하우스 외면에 다겹보온덮개를 피복하고 내부에 보온커튼(알미늄+직물)을 설치한 것은 다겹보온 덮개를 피복하고 보온커튼을 설치하지 않은 것과 이중하우스에 다겹보온덮개를 피복하지 않고 EVA커튼만 설치한 것에 비해 하우스내 기온이 각각 $2.2^{\circ}C$와 $4.5^{\circ}C$ 높게 유지되었으며 이러한 보온효과에 의해 토마토 과실수량도 각각 $18\%$와 $37\%$ 가되었다. 따라서 본 연구결과는 남부지역에서 저온기에 다겹보온덮개를 이중 플라스틱하우스 구조의 외면에 피복하고 내부에 보온성이 높은 커튼자재를 사용하면 가온을 하지 않거나 최소한의 난방비로 토마토를 재배할 수 있음을 시사해 주었다.

• Journal of Acupuncture Research
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• 제28권1호
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• pp.15-28
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• 2011

Objectives : To understand the strength and weakness of traditional warm needle acupuncture based on existing research outcomes in Korea mostly and to suggest how to build the desirable warm needle acupuncture apparatus by overcoming demerits of traditional and currently existing ones. Methods : We searched warm needle relating papers in Korean with the key words of '온침, 화침, 열자극' by using DBpia, Journal of Korean Oriental Medical Society, Journal of Korean Acupuncture & Moxibustion Society and Journal of Society for Meridian and Acupoint. Degree dissertations in Korean were also searched with the same words through the search engine of Library of Kyung Hee University. We also searched with words of 'warm, thermal, heat, needle, acupuncture, temperature' via Pubmed and found a small number of English written papers and large number of Chinese written ones. To find english translated version of those papers, we googled with the same words with no success. Results : About 20 papers on warm needle acupuncture written in Korean were found and analyzed with respect to experimental factors that affected the thermal properties or the amount of heat stimulus of the acupuncture. More rigorous descriptions seemed to be required on the insertion depth, duration and manipulation of warm needle treatment. A basic heat transfer model was presented for the clarification of heat loss through the needle of warm needle acupuncture. Environmental factors such as air flow on the properties seems to be considered for the warm needle acupuncture. Conclusions : Papers on warm needle acupuncture were reviewed and analyzed based on their thermal properties and tools such as needles and moxa cones. Several suggestions were made on the descriptions relating the properties. Necessary specifications were introduced to aim modernized warm needle systems.