• Journal of Applied Biological Chemistry
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• 제59권1호
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• pp.69-74
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• 2016

시금치에 fumaric acid와 mild heat의 병합처리를 통해 병원성 미생물 제어효과를 규명하고자 시금치에 E. coli O157:H7, L. monocytogenes 를 접종한 후 각 단일처리 후 미생물 수 변화를 측정하였다. Fumaric acid (0.1, 0.3, 0.5%)와 mild heat (40, 50, $60^{\circ}C$)의 각 단일처리 실험 결과를 토대로, 병합처리를 위한 fumaric acid의 최적농도는 0.5%, mild heat 처리조건으로 $50^{\circ}C$에서 5 min으로 선정하였고, 병합처리 시 L. monocytogenes, E. coli O157:H7의 수는 대조구에 비해 각각 2.53, 2.62 log CFU/g 감소하였다. 그리고 신선한 시금치에 병합처리 후 $4^{\circ}C$에서 12일간 저장하면서 미생물 수 감소 및 품질 변화를 조사하였다. 시금치의 초기 미생물 수에 있어서 대조구와 비교하여, 병합 처리구에서 총 호기성 균을 2.77 log CFU/g 감소시켰다. 특히, 저장 12일 후 병합 처리구의 총 호기성 균 수는 4.84 log CFU/g으로 대조구와 비교하여 1.82 log CFU/g의 감균 효과를 가졌다. 또한 시금치의 저장 중 Hunter 색도 값 및 비타민 C 함량에 있어서 처리구 간의 유의적인 차이를 보이지 않았다. 따라서 본 연구 결과, fumaric acid와 mild heat의 병합처리가 시금치의 미생물학적 안전성 유지에 효과적인 처리라고 판단된다.

• 한국의류학회지
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• 제30권4호
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• pp.607-614
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• 2006

This study was carried out to suggest the optimal spinning process condition which provides a proper range of tenacity and biodegradability as textile fibers. The effects of the melt spinning speed and heat treatment on the mechanical property and biodegradability of polylactic acid fiber were investigated. Polylactic acid(PLA) was spun in a high spinning speed of $2000{\sim}4000m/min$. Each specimen was heat-treated at $100^{\circ}C$ during 30min. Mechanical properties such as breaking stress and the degree of crystallinity were evaluated using WAXS. Biodegradability was estimated from the decrease of breaking stress, weight loss, and the degree of crystallinity after soil burial. Experimental results revealed that heat treated specimens showed higher breaking stress than untreated specimens, but the increase was not so high as was expected from the remarkable change of crystallinity by heat treatment. It was concluded that breaking stress was more influenced by spinning speed than heat treatment. In the soil burial test, however biodegradability calculated from weight loss was more influenced by heat treatment than spinning speed.

• 한국식품과학회지
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• 제20권3호
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• pp.317-325
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• 1988

농축대두단백으로 만든 두유를 여러 가지 정도로 가열 처리한 후 젖산균 5종을 각각 접종하여 두유의 가열처리가 젖산균의 생육과 산생성 그리고 대두요구르트의 관능성과 커드의 침전에 미치는 영향을 관찰하였다. 먼저 산생성을 보면 표준시료(비가열(非加熱)시료)에 비하여 $60^{\circ}C-10$분 또는 그 이상의 가열로 모든 균주에서 산생성이 촉진되었으며 그 촉진의 정도는 대체로 가열의 정도가 높을수록 점차적으로 증가하여 Streptococcus lactis를 제외한 4균주의 산생성이 $121^{\circ}C-1$분에서 가장 높았다. 그러나 생균수는 가열 처리로 큰 변화가 없었다. 대두젖산균 음료의 관능성에 미치는 영향을 보면 $95^{\circ}C-30$분 시료의 관능 성은 표준시료보다 현저하게 우수하였으나 $121^{\circ}C-15$분 시료의 관능성은 표준시료보다 현저하게 저조하였다. 한편 두유의 가열처리로 대두젖산균 음료의 침전이 지연디는 경향을 보였으며 특히 $121^{\circ}C-15$분의 가여로 침전이 현저하게 지연되었다.

• Current Research on Agriculture and Life Sciences
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• 제31권1호
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• pp.25-29
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• 2013

As a specialty oil, furan fatty acids have gained special attentions since they are known to play important roles in biological systems including human. Although several studies reported chemical synthesis of furan fatty acids, their synthesis consisted of complicated chemical multistep with chemical catalysts. Recently, a simple one-step heat treatment method was developed to produce a novel furan fatty acid, 7,10-epoxy-octadeca-7,9-dienoic acid (7,10-EODA) from a dihydroxyl fatty acid 7,10-dihydroxy-8(E)-octadecenoic acid (DOD). In this report we studied about optimization of environmental conditions for the maximum production of 7,10-EODA from DOD by heat treatment. Production of 7,10-EODA was maximized at over $85^{\circ}C$ for at least over 48 hour in hexane. Solvent volume for maximum production should be over 300 mL per 10 mg DOD.

• 한국식품저장유통학회지
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• 제20권1호
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• pp.23-29
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• 2013

박피 연근절편의 선도연장을 위한 연구로 연근절편을 $50^{\circ}C$ 물에 열수 처리하였고, 아울러 시너지 효과를 조사하기 위해 열처리와 ascorbic acid 1%와 citric acid 1%를 각각 병행 처리한 후 $5^{\circ}C$에서 12일 동안 저장하면서 미생물수, 색상 및 관능적 품질변화를 조사하였다. 일반세균수는 열수 및 citric acid 병행 처리구의 경우 저장 9일후 그 값이 가장 낮았으며, 이를 제외한 다른 처리구들은 유의적 차이가 없었다. 곰팡이 수의 경우 대조구가 6.81 log CFU/g을 나타낸 반면, 열수 처리구는 12일 후 3.89 log CFU/g으로 유의적으로 낮았다. 연근절편 색도의 L값은 시간이 지남에 따라 점차 감소하는 경향을 나타낸 반면, ${\Delta}E$값은 점차 증가하는 경향을 보였다. 대조구가 급격히 색 변화가 일어나는데 비해 열수 처리구는 완만한 변화를 보였고 열처리 후 각각 ascorbic acid와 citric acid를 병행한 처리구는 색 변화가 거의 일어나지 않았다. 관능적 품질평가 결과, 상품성은 대조구가 3일간 유지되었던 반면 열수 처리 구는 9일간, 열수 및 유기산 병행 처리구는 12일간 상품성이 유지되었다. 전반적인 품질, 색, 조직감 등은 열처리를 한 처리구들이 열처리를 하지 않은 처리구에 비해 기호도가 유의적으로 높았으며, 그 중 열수 및 유기산 병행 처리구가 관능적으로 가장 높은 값을 나타내었다. 본 실험을 통해, 연근 절편의 열처리는 미생물과 갈변을 억제시킴으로써 연근의 관능적 품질유지에 효과적이었고, 특히 citric acid 1%를 열처리와 함께 병행하는 것이 연근의 품질유지와 갈변억제에 가장 효과적인 것으로 판단되었다.

• 한국식품조리과학회지
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• 제18권5호
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• pp.487-494
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• 2002

This study was conducted to investigate the thermal stability of water-soluble and fat-soluble vitamins dissolved in water and milk by various heat treatments. Vitamin samples were prepared by dissolving them in water and milk at various concentrations, and were heat treated for 30 min at 65$\^{C}$, 15 sec at 85$\^{C}$, 5 sec at 100$\^{C}$, 121$\^{C}$ at 15 min, the levels of residual vitamin were measured by using HPLC. Milk samples were fortified with vitamins before and after UHT treatment. As heating over 100$\^{C}$, riboflavin in water were destructed more than 92% but fortified in milk showed less than 20% destruction, suggesting that riboflavin was protected by milk components. Also retinol heated ever 100$\^{C}$ was more stable in milk than in water. L-Ascorbic acid and cholecalciferol(D$_3$) showed a similar destruction rate in water and in fortified milk. L-ascorbic acid was easily destructed by UHT treatment. Destruction of thiamin and tocopherol was increased in fortified milk. Among tour capsulated water-soluble vitamins, L-ascorbic acid was much more stable compared with powder form. Nicotinic acid and folic acid either in capsule or powder form showed a slight destruction by heat treatment. The results suggested that the fortification of unstable vitamins such as L-ascorbic acid, thiamin, tocopherol and cholecalciferol(D$_3$) should be made in milk after heat treatment.

• Journal of the Korean Wood Science and Technology
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• 제51권1호
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• pp.49-57
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• 2023

This research aimed to evaluate the durability of Samama (Anthocephalus macrophyllus) wood treated with boron preservatives, citric acid (CA), and heating against termites. Wood samples were impregnated firstly with 5% boron solutions, such as boric acid, borax and boric acid + borax combination at 1:1 (w/w). The second impregnation used 5% CA. The impregnations were conducted in a pressure tank at 7 kg/cm² for 4 hours. After impregnation, the samples were heat treated at 80℃ or 160℃. All the treated and control samples were exposed to decay fungi, drywood termites and subterranean termites based on SNI 7207:2014 standard. The results showed that boron preservatives reduced fungal attacks on Samama wood. The combination treatment of boric acid, CA and heat treatment at 160℃ was also effective to increase the resistance of Samama wood against white- and brown rot fungi, and drywood termites. Heat treatment consistently improved the resistance of Samama wood from decay fungi.

• 한국전기전자재료학회논문지
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• 제23권1호
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• pp.65-69
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• 2010

In this study, we compared two methods(an acid treatment in strong acid reflux and a heat treatment in air atmosphere) for hydrophilic surface treatment of multi-walled carbon nanotubes(MWNT) to enhance the capcity of $RuO_2$/MWNT composite electrode materials for ultracapacitor. Both treatments generated a number of defects on the surface of MWNT by the breakage of $\pi$ bond in graphene layer at which carboxyl groups were introduced. However, the degree of hydrophilicity generated by strong acid treatment was higher than that by heat treatment in air, which was revealed by the quantitative measurement of surface carboxyl groups by using Boehm titration. The increased hydrophilicity save rise to an improved dispersity of $RuO_2$ nanoparticles on MWNT. Finally, the improved dispersity resulted in the capacity enhancement of composite electrode materials for ultracapacitor.

• Carbon letters
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• 제9권2호
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• pp.137-144
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• 2008

The commercial activated carbons are typically prepared by activation from coconut shell char or coal char containing lots of inorganic impurities. They also have pore structure and pore size distribution depending on nanostructure of precursor materials. In this study, two types of commercial activated carbons were applied for EDLC electrode by removing impurities with acid treatments, and controlling pore size distribution and contents of functional group with heat treatment. The effect of the surface functional groups on electrochemical performance of the activated carbon electrodes was investigated. The initial gravimetric and volumetric capacitance of coconut based activated carbon electrode which was acid treated by $HNO_3$ and then heat treated at $800^{\circ}C$ were 90 F/g and 42 F/cc respectively showing 94% of charge-discharge efficiency. Such a good electrochemical performance can be possibly applied to the medium capacitance of EDLC.

• 한국광물학회지
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• 제20권4호
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• pp.247-253
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• 2007

규질이암의 열처리 및 산 침출이 소듐 실리케이트나 규산 수용액과 같은 실리카 전구물질 순도에 미치는 영향을 연구하였다. 규질이암의 열처리 온도, 산 침출시 염산 농도 및 황산 농도를 변화시키며 전구물질 내에 실리콘 함량을 최대한 높이면서 에너지 및 화학약품의 소모는 최소화하는 조건을 구하였다. 열처리는 $600^{\circ}C$, 산 침출은 1.56 M의 염산만 사용하였을 경우 최적이었다. 소듐 실리케이트와 규산 수용액의 실리콘 순도는 각각 최대 99.2%와 99.5%였다.