• Korean Journal of Weed Science
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• v.14 no.4
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• pp.233-238
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• 1994

The experiment on sprouting and emergence properties of Eleocharis kuroguwai was conducted at laboratory and greenhouse conditions in 1993. Most of tubers had the apical dominance of buds at sprouting and had the competitive relationship for mesocotyl elongation. When pyrazosulfuron was applied on soil surface, all of apical buds were killed, but the first and second lateral buds survived to 50% and 90%, respectively, and the third lateral buds were almost at presprouted state. The tubers at 10-15cm deep soil emerged 1 week late and 35% low in emergence rate compared with the tubers at 2-5cm deep. As the plants emerged from the deep soil, the mesocotyl and the roots were distributed at deep soil more or less. Among the tubers buried at 10cm and 15cm deep soil, 25% and 30% respectively were not emergerd due to the suspension of mesocotyl elongation. Although the roots and shoots were removed from the tubers at the stage of 20cm high, all of mother tubers emerged again even 2 weeks late.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2000.11a
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• pp.117-117
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• 2000

제지공정의 마지막 단계인 캘린더는 지필의 표면을 평활하게 하고 두께를 감소시켜 균일 하게 하는 역할을 한다. 하지만 캘린더링은 인장강도 둥의 강도적 성질과 불투명도 등 광학 적 성질을 저하시키는 공정이기도 하다. 따라서 캘린더령 공정에 의한 제품 품질의 저하를 극소화하기 위해서는 공정인자의 엄밀한 관리가 요청된다. 캘린더링의 주요 공정인자에는 온도와 압력, 닙 체류시간, 유입지의 함수율, 유입지의 온도 롤의 재질 등이 있다. 이 가운 데 특히 캘린더링 온도와 압력은 주요한 공정 인자이다. 따라서 이들 변수에 의한 캘린더링 공정의 변화를 정확하게 파악하는 것은 매우 중요하다. 캘린더링 공정의 속도와 관련된 닙 체류시간과 유입지의 함수율, 유입지의 온도, 롤의 재질 등은 실제 공정에서 변화시키기 어 려운 반면 온도와 압력은 조절이 비교적 용이한 특정도 지니고 있다. 캘린더링 전후의 종이의 물성 차이는 지필 내부로의 열 침투에 의한 열변형에 따라 크게 달라진다. 셀룰로오스는 유리전이온도 이상으로 가열되면 그 성질이 크게 변화하므로 캘린 더링 시의 온도가 유리전이온도보다 높거나 낮은 경우 캘린더링된 종이의 물성 차이가 크게 달라질 수 밖에 없다. 캘린더령은 비정상상태에서 진행되기 때문에 지펼의 내층보다는 표층 으로부터 순차적으로 열변형이 발생하는 공정이다. 그러므로 지필의 두께 방향으로의 열 침 투 현상의 해석을 통하여 캘린더링 시 유리전이온도가 어느 깊이까지 도달하는가를 파악하 는 것은 캘린더링 공정의 해석에 매우 중요하다. 캘린더링 공정에서 발생하는 열전달현상 해석 시 지필의 압축을 고려하지 않고 비압축성 물질로 가정하는 것은 캘린더링 공정 인자 중 압력에 의한 영향을 제대로 평가하지 못하는 한계를 지니게 된다. 따라서 본 연구에서는 지펼의 압축성을 고려하여 캘린더링 모델을 정립 하고, 이를 토대로 캘린더링 공정 조건에 따른 열 침투 현상을 해석코자 하였으며, 그 방법으 로 수치해석기법을 도입하였다. 또 실제 캘린더링 전후의 두께 변화를 측정하여 유리전이온도 의 도달 깊이와 비교하였다. 지필의 압축 정도는 롤의 직경과 닙 폭을 이용하여 MD 방향으 로 함수화하였으며, 열전달 계수로는 겉보기 값을 사용하였다. 이때 지펼은 균질한 것으로 가 정하였다. 함수율은 유리전이온도를 좌우하는 가장 큰 인자이나 본 연구에서는 항온항습처리 를 통해 유입지의 함수율을 고정시켰으며 캘린더링 시 함수율의 변이는 없다고 가정하였다. 그 결과 열침투깊이가 증가할수록 지필은 보다 변형되기 쉬운 상태가 되어 주어진 압력 조건에 대해 소성변형 정도가 증가하는 것으로 나타났다. 이는 캘린더링 전후에 두께 변화를 측정하여 정량적으로 평가할 수 있었다. 수치해석기법을 통해 같은 압력 조건에서 온도가 증 가함에 따라 혹은 같은 온도 조건에서 압력이 증가함에 따라 지필 내의 유리전이온도의 침투 깊이가 증가함을 알 수 있었으며 이는 캘린더링 전후의 두께 변화의 측정 결과와 일치하였 다. 또 NRT가 증가함에 따라서도 유리전이온도 침투 깊이가 증가하였다.

• Applied Biological Chemistry
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• v.40 no.2
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• pp.128-133
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• 1997

This study was conducted to evaluate the adsorption, desorption, leaching and degradation pattern of fungicide fluazinam in the soil environment under the laboratory conditions. The mode of isothermal adsorption of fluazinam in soil was coincident with the Freundlich equation. The adsorption amount of fluazinam was much higher on soils containing organic matter than on soils oxidized with hydrogen peroxide. The presence of organic matter, humic acid or fulvic acid, increased the adsorption amount of fluazinam on soils. The Freundlich constant K was much higher in soil added with humic acid than in soil added with fulvic acid. The desorption ratio of fluazinam adsorbed to soil was increased by removal of organic matter. In leaching experiment using soil column, the fluazinam applied on the soil surface was not moved down to the bottom of soil and was not detected in leachate water. The degradation of fluazinam was faster in Soil I with rich organic matter than Soil II with poor organic matter, in non-sterilized soil than sterilized soil, and in flooded soil than unflooded soil.

• Korean Journal of Weed Science
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• v.14 no.1
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• pp.49-55
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• 1994

A study was conducted to determine the effect of depth of burial, soil temperature and/or moisture on tuber sprouting of E, kuroguwai. Tubers were evenly distributed in the upper 30cm of soil. Tuber weight increased as depth of tuber formed increased. No dormancy in newly formed tubers was found, whereas mature tubers were dormant. When new tubers were subjected both to continuous $5^{\circ}C$ and to gradual decreasing temperatures regimes ranged from 20 to $1^{\circ}C$ for 30 days, the tubers remained non-dormant. Viability of tubers was reduced when buried at 5cm depth in dry and moist soil conditions, but no reduction was obtained when buried at 25cm depth, regardless of soil moisture conditions employed. Percent sprouting of tubers buried at 25cm depth increased with increasing duration of burial in three soil moisture conditions studied, wherease in dry and moist conditions percent sprouting of tubers buried at 25cm depth increased by 60-day burial and thereafter decreased. In submerged condition, tuber sprouting was greater when buried at 5cm depth than when buried at 25cm depth, and increased as duration of burial increased at the both depths.

• Journal of the Mineralogical Society of Korea
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• v.26 no.3
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• pp.189-196
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• 2013

In this study, we tried to define the origin of fine-grained sediments in Southwestern Cheju Island Mud (SWCIM) using principal component analysis. We used relative clay mineral compositions using 138 marine surface sediments, 4 Huanghe sediments and 3 Changjiang river sediments by the semi-quantitative X-ray diffraction analysis. We made bioplot diagram using R program with principal component 1 and component 2 because they might contain more than 90% of all data. Although the distribution pattern of each clay minerals in SWCIM is so intricate, smectite and kaolinite contents are high in the west region, but illite and chlorite contents are rich in the east region. In the biplot, the east region of SWCIM distribute around Changjiang river, whereas west region of SWCIM disperse around Huanghe. Our results might reveal that west region of SWCIM is mainly originated by Huanghe, but east region of SWCIM by Changjiang River.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.23 no.3
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• pp.198-207
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• 1990

Among the biodegradable liquid waste treatment and disposal methods, ocean dumping is a cost-effective and productive manner considering reuse point of view However, when biodegradable liquid waste is dumped in the ocean, oxygen consumption by the decomposition of organic matter must be considered. The purpose of this study is to determine the maximum allowable concentration and dumping rate in the southern waters of the East Sea based on dissolved oxygen level. Streeter and Phelps' model has been used to determine the maximum allowable concentration. Factors in this model, deoxygenation constants and reaeration coefficients, have been determined by appling oxygen consumption method and closed system model. Deoxygenation constants and reaeration coefficients from surface to each standard depth are $0.24\~0.29/day\;and\;0.03\~0.39/day$ in summer, $0.17\~0.20/day\;and\;0.04\~0.56/day$ in winter, respectively. The allowable organic matter concentration($mgBOD/\iota$) to the dissolved oxy-gen sag value of $5mg/{\iota}$ is represented $17.23\times(H)^{-0.37}$ in summer, and $64.96\times(H)^{-0.52}$ in winter by mixing depth(H, m). Csanady's experiment has been applied to estimate the optimum dumping rate. The optimum dumping rate($R,\;m^3/sec$) can be written as a product of the beam(b, m) and the draft(h, m) of vessel, and biochemical oxygen demand of waste($L_n,\;mg/{\iota}$) $R=275{\times}bh^{0.63}L_n^{-1}$ in summer $=745{\times}bh^{0.48}L_n^{-1}$ in winter. The difference of dumping rate between in summer and winter is due to the oxygen distribution.

• Journal of the korean academy of Pediatric Dentistry
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• v.39 no.1
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• pp.1-10
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• 2012

The concept of resin infiltration which was born in an innovative philosophy to arrest the incipient caries. However, the structural changes of resin infiltrated lesions have not yet explained completely. The liquid resin might contribute not only to maximizing the penetration but to deteriorating physical stability. This study was performed to examine some physical and histological features of resin infiltrated incipient carious lesions. With the specimen of resin infiltrated lesions, microhardness by nanoindentation in depth profile, morphology of resin tags were revealed after HCl dissolution, and degree of microleakage were assessed. The percentage of microhardness of surface layer and lesion body of untreated specimen to sound enamel was 64.6% and 24.6% respectively, while that of resin-infiltrated lesions was 72.1%, showing significant difference (p<0.05). The resin tags observed under SEM had relatively homogeneous length of 433(282~501) ${\mu}m$ on the average. Among 20 specimens for microleakage assessment, 13 specimens showed no leakage while 5 and 2 showed leakage into outer and inner half of lesion respectively. It was thought the infiltrant resin penetrates deeply and homogeneously into lesion body and improves its hardness with relatively good physical stability.

• Restorative Dentistry and Endodontics
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• v.20 no.2
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• pp.856-868
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• 1995

The effect of collagen dissolution in acid conditioned dentin layer on resin - dentin adhesion was investigated. 160 freshly extracted human molars were divided into 4 groups randomly and dentin surfaces were exposed. 40 exposed dentin surfaces were not acid conditioned and each 10 of them were applied with bonding agents within dentin bonding systems of All Bond 2, Scotchbond Multipurpose, Clearfil Photobond and Superbond D - Liner respectively. Each 10 of another 40 exposed dentin surfaces were acid conditioned by the acid within the above four bonding systems respectively and applied with corresponding bonding systems. After acid conditioning of the other 40 exposed dentin surfaces as above, they were treated with 5% NaOCl for 2 minutes, and each 10 of them were applied with the above four dentin bonding systems respectively. The remaining 40 dentin surfaces were acid conditioned and treated with 10% NaOCl for 2 minutes, and each 10 of them were applied with corresponding bonding agents as the above. After the procedures were finished, composite resin (Z -100, 3M Dent. Prod., USA) were applied on the dentin surfaces and light cured. Shear bond strength values were measured. Surface changes of fractured dentin specimens were observed using SEM (Hitachi S-2350, Japan). The following results were obtained. 1. In all of dentin bonding systems, shear bond strengths of non - conditioned specimens were significantly lower than those of acid conditioned specimens (P<0.05). 2. A statistically significant difference of bond strengths did not exist between acid conditioned specimens and 5% NaGCI retreated specimens applied with All Bond 2, Scotchbond Multipurpose and Clearfil Photobond (P>0.05). However, strength values of 5% NaOCl retreated specimens applied with Superbond D - Liner were lower than those of acid conditioned specimens (P<0.05). 3. In all the applied dentin bonding systems except Clearfil Photobond, bond strengths of 10% NaOCl retreated specimens were lower than those of acid conditioned and 5% NaOCl retreated specimens (P<0.05). 4. The resin - dentin hybrid layer of 4 - $5{\mu}m$ thickness was formed in the acid conditioned specimens applied with All Bond 2, Scotchbond Multipurpose and Superbond D-Liner. 5. The resin - dentin hybrid layer of 3 - $4{\mu}m$ thickness was still formed in the 5% NaOCl retreated specimens applied with All Bond 2 and Scotchbond Multipurpose. In addition, this layer was not completely removed after the retreatment with 10% NaOCl. Above results indicate that the dissolution of collagen in acid conditioned dentin layer by NaOCl solution can not be achieved completely and the collagens contribute to the resin - dentin adhesion considerably.

• Journal of Welding and Joining
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• v.17 no.2
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• pp.25-28
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• 1999

국내에 건설되어 거의 20∼30년 가동되고 있는 발전설비, 석유화학 플랜트 등 거대설비 기기의 건전성(integrity) 및 신뢰성 확보와 잔존수명 예측을 위해서는 구조물 내부 또는 표층부에 존재하는 결 함의 특성을 아는 것과 함께 그 재료의 특정 부위에 어느정도의 응력이나 변형이 있는가를 아는 것이 매우 중요하다. 일반적으로 강 용접부의 비파괴적 결함검출에는 주로 SV파(vertically shear wave)와 SH파(horizontally shear wave)라 불리는 횡파를 이용한 초음파사각탐상법이 실용화되어 이용되고 있다. 그러나 비파괴적인 방법에 의한 실험적인 잔류응력 측정, 변형해석법에는 전기 저항 및 자기 스트레인 게이지법, X선회절법, 광탄성법(photoelasticity), 모아레(Mohr's)법, 레이저스펙클(Laser speackle)법, 응 력도료법, Barkhausen Nosise법, Caustics법 등이 제시되어 있으나 그 유용성 면에서는 아직 해결되야할 문제가 많이 남아 있는 실정이다. 응력이나 변형을 해석하는 방법으로 이론적 방법, 계산적 방법 실험적 방법이 잇다. 이론적 방법에는 재료 역학적으로 취급하는 방법, 탄성론 등이 있고, 계산적인 방법에는 유한요소법이 있지만, 이론적 방법이나 계산적 방법만으로는 해석이 불가능한 경우가 많기 때문에 실험 적 방법이 필요하게 된다. 이 글에서는 파괴 시험 또는 다른 비파괴평가기술에 비해 간편한 측정, 높은 측정정도, 시험결과 도출의 신속성, 검사비용의 절감 등 많은 장점을 가지고 있고 실험적으로 유용성이 일부 검증되고 있는 음탄성법(Acoustoelasticity)에 의한 잔류응력 측정법에 관해 소개하고자 한다.TEX> mg/L(평균 49 mg/L)로 비교적 안정적인 처리효율을 보여주었다. 본 연구결과 HVC 공정은 화학약품 사용량의 절감 및 이에 따른 화학슬러지 발생량의 감소를 기대 할 수 있는 친환경기술로 유지관리비를 최소화할 수 있는 장점이 있었다. 않은 사람들 중 미래의 검진실행의지에 건강소식지가 영향을 미친 경우는 48.7%였다. 보건교육을 받은 후 유방암 자가검진 실천율은 사업군에서 53.9%로 받기 전의 27.3%보다 증가하였으나 대조군의 경우는 별 차이가 없었다. 연령별로는 60대가 가장 높았고 사업군에서 검진율의 증가분은 30대가 가장 컸다. 교육수준별로는 사업군은 고졸이, 대조군은 전문대졸이 가장 높았고 사업군에서 검진율의 증가분은 고졸에서 가장 컸다. 보건교육 후 유방암과 관련된 건강지식의 정도는 사업군이 3.7점으로 대조군보다 유의하게 높았으며, 유방암 자가검진법을 실천하는 사람들의 동기는 ‘일반 대중매체의 영향’이 가장 많았으며 건강소식지가 동기인 경우도 20.4%였다. 사업군에서 건강소식지가 유방암 자가검진법 실천에 영향을 미친 경우가 79.6%였으며 유방암 자가검진법에 관한 보건교육을 받고 실천하지 않은 사람들 중 미래의 실천의지에 건강소식지가 영향을 미친 경우는 43.6%였다. 이상의 소견에서 지역주민을 대상으로 인쇄매체를 통한 보건교육은 인쇄물만으로도 쉽게 실천 할 수 있는 유방암 자가검진법이 가장 효과적이었으며, 자궁암검진에 관해서도 검진을 받을 수 있도록 지역사회의 보건의료의 하부구조를 정비하여 제도적 장치를 마련하고 정보를 제공한다면 자궁암검진 실천율도 증가할 것이다.고 12.9% 의 발달율을 보여 유의적인 차이를 보이지 않았다. 이상의 결과로 보아 핵이식 수정란을 효율적으로 생산하기 위하여

• Journal of Navigation and Port Research
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• v.43 no.1
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• pp.64-71
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• 2019

It is very important to understand the mechanism of estuary topographic changes for the study of estuary management and treatment methods. In this study, the effects from the land-side, such as rainfall, river discharge, sediment discharge, and sea side, such as tide, tidal current, wave and surface sediments related to the topographic changes of the Nakdong river estuary were investigated and analyzed. Based on the analyzed data, topographic modeling was performed to analyze the topographic change and contribution of external force conditions. As a result of numerical modeling, the topographic change showed that erosion that predominates in the water directly affected by the discharge of the estuary barrage. The deposition predominates in the indirectly affected tideland. As sediments moved along the water way being sorted and distributed by the wave, the deposition predominated in the front of the barrier island. Compared with the deposition dominance, which is the result of the topographic change prediction, the impact of each external force condition gives larger erosion. However, the combined impact of each external force condition showed deposition dominant. Therefore, the topographic changes of the Nakdong river estuary are considered to be the result of various complex external factors. The impacts of each external force condition show the different contribution to each comparison area. These results should be considered when establishing the estuary management method. It must be understood that this is the result of complex interactions.