• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2000.11a
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• pp.139-139
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• 2000

종이는 제조 후 시간의 경과에 따라 노화가 야기되기 시작하며 이에 수반되는 현상으로서 종이의 기계적 강도 손실 및 종이의 색 변화를 들 수 있다. 종이의 노화 현상은 주로 빛, 열, 대기 오염물질, 미생물, 곤충 및 화학약품 등의 외부 인자들에 의해 종이 내에서의 가수 분해 또는 산화작용을 발생시키며 이는 종이의 폭넓은 이용올 제한하는 중요한 원인이 되고 있다. 종이의 노화기작은 주로 산 가수분해 및 산화작용 그리고 가교결합 둥으로 해석되고 있다. 이는 종이의 주 구성요소인 셀룰로오스의 수산기가 반웅하여 카르보닐기를 형성하면 서 저분자화 되거나 산소에 의해 산화되면서 저분자화 되어 종이의 강도적 손실이 일어난다 고 보고되고 있으며 종이의 황색화(Yellowing) 현상은 주원인이 종이에 잔존하고 있는 리그 년이 빛과 열에 의해 반응하여 산화됨으로써 야기된다고 설명되고 있다. 즉, 열이나 자외선 및 가시광션의 조사로 인한 셀룰로오스 및 기타 종이 구성물의 산화에 의해 종이가 퇴색되 거나 강도가 저하되는 현상이 일어나게 된다. 특히 이러한 노화 거동은 상온의 경우에서는 펄프와 종이의 황색화가 천천히 일어나지만 옹도가 점차 올라갈수록 그 속도는 빨라진다. 종이가 노화되면서 일어나는 산화반용은 주로 대기 중의 산소와 접촉하기 쉬운 표변에서부 터 발생하기 쉽다. 열처리를 통해 표면에서의 산화 작용은 촉진되고 종이의 구성원소의 결 합에 화학적 변화가 야기된다. 이를 분석하기 위해서 모든 원소가 독특한 결합에너지를 가 지고 있다는 것에 착안 시료 표면에 특정 x-선 및 전자빔을 입사하여 방출하는 광전자의 에너지를 측정함으로써 시료 표면의 조성 및 화학적인 결합상태를 알 수 있는 ESCA ( (Electron Spectroscopy for Chemical Analysis)를 이용하였다 .. ESCA는 주로 표면 원소의 규 명 및 정량분석과 화학결합 상태의 정성, 정량 분석, 깊이에 따른 원소의 농도 분포 분석, 고분자화합물의 특성 조사, 표면 원소의 화학결합에 따른 전자상태 연구 둥에 활용되 고 있 다. 즉, 종이가 노화되면서 원소들 사이에 변화되는 결합을 이러한 에너지 분석에 의해 원소 정성분석 또는 정량분석을 하고자 하였으며, 이를 분석하여 열처리 시 종이 표면에서 일어 나는 변화를 구명하고자 하였다. 이에 따라 본 연구에서는 종이의 노화를 가속화시키는 빛, 대기오염물질, 및 기타 다른 인 자들은 배제하고 열 만을 가해 노화의 진행속도를 높인 후, 노화 진행 시 종이 표변에 일어 나는 산화작용 및 가수분해를 표면 분석 장치인 ESCA를 이용하여 종이의 주 구성원소인 탄소와 산소가 열처리 시 변하는 에너지를 측정하였다. 또한 카르복실기 정량과 종이의 pH 측정 및 X -ray Diffractometer를 이용하여 결정화도를 측정하였다. 본 연구의 결과, 시간의 경과에 따라서 탄소의 결합에너지는 분포가 C-H에서 COO-, 또는 C=O로 달라짐으로써 종 이가 산화되고 있다는 것을 알 수 있었다. 또한 이 결합에너지 분포의 변화가 펄프의 종류 에 따라서 다르게 이동함으로써 제조된 시트의 표면 산화반응이 서로 다르게 일어나고 있음 을 알 수 있었으며, 이는 사용한 펄프의 화학 조성분의 차이에 기인한 것이라 사료된다.

• The Journal of Industrial Distribution & Business
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• v.2 no.1
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• pp.29-37
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• 2011

It remains that South and North Korea are the most conflict ridden region of the world and at high risk of military collision despite the appropriateness and necessity of unification between South and North Korea. Meanwhile, our government has pushed ahead with exchange between the two countries in many different fields to defuse this conflict and tension. But, these efforts have made it less meaningful as South-North relations are strained again. This can be because temporary recovery of political relation didn't proceed to system improvement and economic cooperation. This study on exchange cooperation of circulation · distribution between South and North Korea begins with expectation that this study will be based on realizing free circulation · distribution for the unification and making an economic bloc through exchange cooperation of circulation · distribution. To expand economy exchange and cooperation between the two nations, the field of circulation · distribution should be developed. On the basis of this discussion, this study suggests that cooperation relation and the mood of reconciliation created by political declaration are institutionalized in the national consensus and exchange should be expanded in the economic field as well as political field.

• Journal of the Korean Institute of Landscape Architecture
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• v.45 no.5
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• pp.1-13
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• 2017

This study was intended to provide management directions through the provision of tree spatial information as basic data for the preservation of Gyerim(legal historical site), which is located in Gyeongju city, Gyeonsangnam-do, Korea. As a result of the survey of the entire forest, there are a total of 25 species and 510 individuals growing trees. Of these species, 14 species are native and 14 are introduced species. Apart from Sophora japonica, Zelkova serrata, Celtis sinensis, most of the introduced species were adopted without historical basis after designation as a historical site. By a ratio of 36% to introduced species(including 3% of naturalized species; Ailanthus altissima), the historical heritage was significantly damaged. Gyerim, which has over 2,000 years of history, has a total 15 individuals(2.9%) large trees(over 100cm DBH). Ten of these are Salix glandulosa, and in the past, most of this area was considered a Salix glandulosa forest. Currently, however, there are many small trees(under 20cm DBH) for the next generation of growth and the Salix glandulosa forest will continue to decline. Furthermore, most small trees were afforested, so the historicity and place features as a mythological forest will quickly fade.

• Korean Journal of Agricultural and Forest Meteorology
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• v.3 no.3
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• pp.150-155
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• 2001

The hull dehydration in dough stage did not serious affect the rice yield though grain appearance texture may decline by severe occurrence of the symptom. As to white head in heading stage of rice, the occurrence of hull dehydration in 1998 was directly affected by high temperature, low air humidity and sometimes of strong wind and sunshine in early September. At harvest stage, 1,000-grain weight of brown rice was not found to be significantly different between the hull dehydrated grains and normal ones. That reason can be considered that the hull dehydration occurred hill was not injured on the leaf and rachis branches therefore the function of assimilation and translation of rice plant was not affected. The ratio of imperfect rice kernel such as green, cracked and white belly increased. The increase of cracked rice by the hull dehydration may caused by concurrent dehydration of kernel, or by insufficient water supply into kernel due to breaking of vascular bundles in glume.

• Applied Chemistry for Engineering
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• v.10 no.8
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• pp.1169-1174
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• 1999

2-Diazo-1-naphthoquinone-5-sulfonyl chloride(NQD-Cl) was synthesized from sodium 2-diazo-naphthoquinone-5-sulfonate by chlorination. NQD-Cl was esterified with hydroxybenzophenones to give several 1,2-naphthoquinone-(2)-diazide-5-sulfonic acid ester derivatives(NQD-esters). We have compared benzophenone derivatives with methoxy group to benzophenone derivatives with hydroxy group. Solubility of each NQD-ester was studied. Each of NQD-esters was formulated with novolac base resin and PS plates were manufactured. Photosensitivity, bleachability, compatible exposed time and relative sensitivity were determined by UV spectrophotometry, imaged by UV lithographic techniques, and the gray scale method. According to the number of substituted NQD group, it showed that relative sensitivity was different from gray scale method. NQD-esters with methoxy group showed a good solubility and higher sensitivity than commercial PS ones.

• Korean Journal of Food Science and Technology
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• v.15 no.4
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• pp.364-369
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• 1983

The effect of irradiation on the shelf-life of commercial ham products and its quality were investigated during eight weeks storage at $30^{\circ}C$ following 3-8kGy irradiation. Total bacterial count of unirradiated group was proliferated from. $5.4{\times}10^{3}$ per gram of sample to $10^{6}$ after two weeks storage but the bacterial count in irradiated group was propagated to the same level after three to five weeks storage and the growth of coliform group was shown negative. The freshness of stored ham was better in irradiated group than in unirradiated one and the changes in components related to the quality of ham were almost the same between unirradiated and irradiated group. Discoloration and irradiation odor were positive in 8kGy irradiated group according to the sensory test, but 5 kGy irradiated group was not only good in texture but also in the extension of shelf-life to more than two times as compared with that of unirradiated one.

• The Korean Journal of Food And Nutrition
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• v.11 no.2
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• pp.237-242
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• 1998

This study was carried out to process canned ark shell with highly quality by management of proper processing conditions for prevention of oxidation and discoloration by heating. Ark shell has hemoglobin as blood pigment in red blood shell which same as other cockles. Hemoglobin is easy to come oxidation and browning reaction, and it has large contents of carotenoid as meat pigment. Proximate compositions in ark shell were 76.9% of moisture, 18.1% of crude protein, 1.8% of crude lipid, 1.3% of carbohydrate and 1.6% of crude ash. And contents of carotenoid and hemoglobin were 0.67~1.02mg% and 0.98~1.64g/dl, respectively. When the living ark shell was soaked in 2% NaCl solutions, about 89% of mud was removed after 10 hours soaking, and over 91% was removed when the pH was adjusted to 7.5. Carotenoid pigment were prepared that extracted from ark shell by using acetone. And determined visible spectrum were two peak at 452nm and 687nm, and λmax were 452nm. During thermal treatment at 95$^{\circ}C$, 111$^{\circ}C$, 116$^{\circ}C$ and 121$^{\circ}C$ for 60 minutes, retention ratio of carotenoid were 71.8%, 66.8%, 64.4% and 36.5%, and after 120 minutes retention ratio were 56.6%, 30.6%, 30.3% and 17.2%, respectively. When heated at 95$^{\circ}C$, 111$^{\circ}C$, 116$^{\circ}C$ and 121$^{\circ}C$, formation of browning material were increased at high temperature and long time treatment.

• Korean Journal of Food Science and Technology
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• v.27 no.6
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• pp.1013-1016
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• 1995

The color stability of betacyanins and effects of antioxidants from Opuntia dillenii Haw were determined in the fruit juice at temperature up to $90^{\circ}C$. The absorption maxima of betacyanins occurred between 536 nm and 538 nm. When fruit juice was heated at $90^{\circ}C$ for various times, the red color gradually diminished and the absorption maxima slightly shifted toward uv region. The kinetic analysis of the data obtained indicated that the discoloration for betacyanins obeyed first order reaction pattern, when the thermal stability test was performed at $50{\sim}90^{\circ}C$. And the rate constant increased from $1.56{\times}10^{-3}/min\;to\;71.91{\times}10^{-3}/min$ with the half-life decreasing from 444.23 min to 9.64 min. The results also indicated that the thermal stability of pigment decreased with increasing temperature. The energy of activation was 10.94 kcal/mole for the pigment. N-propyl gallate, L-cysteine, and ascorbic acid were added to cactus fruit juice at concentrations of $0.01{\sim}0.3%$ at different temperatures. Npropyl gallate and L-cysteine had a little antioxidant effect on betacyanins stability at $50^{\circ}C\;and\;70^{\circ}C$, whereas ascorbic acid had a great antioxidant effect with the half-life value of 2 to 10 times to that of the control.

• Journal of the Korea Institute of Building Construction
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• v.13 no.2
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• pp.122-130
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• 2013

One of recent methods to protect wooden cultural assets from fire, there is the flame retardation which is applied directly to wood and it is to prevent fire through securing flame resistance for the material and delaying combustion when failed fire in advance and then to gain time for people in the room to evacuate and it has same goal with the Korean Fire Service Act by protecting life and property. However, in case of spraying flame retardant on the colored surface of the wooden cultural assets, there are continuous problems of decoloration, efflorescence and water absorbtion after sometime and accordingly there increases danger of damages of cultural assets. So when treating with flame retardant on wooden cultural assets, there has to be no problems on dancheong after sometime and securing sustainable methods for flmae retardation should be preceded. Accordingly, this study aims to provide basic sources for selecting proper flame retardation methods by evaluating and analyzing flame retardation capabilities according to types of flame retardants which are frequently used nowadays and spraying them on the dancheong-painted surface and confirming if there is no problem on the dancheong and wood after sometime and if flame retardation effect is sustainable with its quality and capability through precise analysis.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.26 no.4
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• pp.340-345
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• 1993

In order to investigate the quality changes during the storage after curing were determined volatile basic nitrogen(VBN), amino nitrogen, total creatinine, total carotenoid, extents of browning, reducing sugar and glycogen. During the storage of $5{\pm}1^{\circ}C$ after fermented for 1 or 2 days at $25{\pm}1^{\circ}C$, amino nitrogen increased slowely. Whereas the total carotenoid and glycogen decreased. Browning did not occurred for 50 days. Total creatinine increased gradually until 20 days but reducing sugar increased continuously through 50 days of storage. The result of sensory evaluation during the storage of fermented ascidian added $0.1\%$ papain and protease-A with NaCl $10\%\;and\;15\%$ showed that original taste and flavor of ascidian for $30{\sim}40$ days of storage at $5{\pm}1^{\circ}C$.