• 농약과학회지
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• 제9권2호
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• pp.132-139
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• 2005

천연 살균활성 물질인 strobilurin으로부터 유래된 ${\beta}$-methoxyacrylate 계열 화합물들은 천연물 자체보다 높은 살균활성 및 안정성을 보이는 것으로 알려졌으며 실제로 다수의 화합물이 우수한 농업용 살균제로 개발 시판되어 지고 있다. 본 연구에서는 보다 나은 살균제를 개발하기 위한 일환으로 티오엔을 곁가지를 가진 새로운 ${\beta}$-methoxyacrylate 계열 화합물을 고안하고 합성하였으며 이들의 살균활성을 6가지 균주에 대하여 in vivo 활성검색을 수행하였다. 새로이 합성된 화합물들은 선택적으로 벼도열병균 및 밀녹병균에 대하여 우수한 살균활성을 보였으며 특히 1b, 1c, 1g 화합물은 100 ppm 농도에서 벼도열병균과 밀녹병균에 대하여 100% 살균효과를 보였다.

• 보존과학연구
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• 통권6호
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• pp.247-258
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• 1985

Conservation laboratory was attached to Keimyung University Museum inMarch 1980 and ever since it has been devoted mainly to the processing andconservation of metal objects. A number of objects have been processed inthis laboratory during the period, including those already in the collection ofthe Museum, those which were discovered during the three major excavationsof Kaya tombs conducted by the Museum, and those processed on commissionfrom other museums in the country,The activities of this laboratory include: (1) conserving the objects againstfurther erosion; (2) raising the archaeological value of the objects by revealingthe structure of such parts of the objects as concealed under rust; and (3)recovering the original shape of damaged objects.The methods adopted by the laboratory include: (1) removing from theobjects the ionized chlorine which usually are the major cause of erosion; (2)strengthening the objects by soaking them in acrylic resins; and (3) applyingresins to the surface of the objects to protect them from further erosion.Chemicals much employed by the laboratory includes the acrylic resin(Ruschot; developed jointly by the Cultural Property Research Institute ofKorea and Samwha Paint Company), the sodium sesquicarbonate, the sodiumhydroxide, the lithium hydroxide, and the benzotriazole.Major apparatus in the laboratory includes the vacuum immersion tank, theairbrasive, the ultrasonic cleaner, the pH-ion meter, the water bath, the zoomstereo microscope, the drying oven, and the drill.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2006년도 전기학술대회논문집
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• pp.265-266
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• 2006

The chemical conversion coating formed on magnesium alloy investigated for low cost and harmless in environment by using the colloidal silica as the main component. The film formed in 298 K is thick, the film, which was thought combination of Si-O, was formed. The film formed in 313 K is thinner than that in 298 K. The quantity of film formed at high temperature such as 333 K and 353 K is smaller than dissolved quantity. At the anodic polarization experiment, corrosion resistance in sealing by hot water after chemical conversion treatment in basic solution condition get worse than that in comparison with basic solution condition. In salt spray test, the ratio of black rust on specimen that did not conducted chemical conversion treatment was five times or more compared with those of chemical conversion treated specimen. The film thickness of chemical conversion coating produced by alkali treatment process is thinner than in comparison with that of specimen produced in basic chemical conversion treatment solution condition. It is thought, however, that it showed good corrosion resistance during salt spray test because the area of microcracks is small.

• Corrosion Science and Technology
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• 제2권4호
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• pp.165-170
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• 2003

Atmospheric corrosion behaviors of Zn, Zn-5%Al and Zn-55%A l coated steels have been investigated under cyclic wet-dry environments containing chloride ions. The wet-dry cycle was carried out by alternate exposure to immersion in 0.5 M (or 0.05 M) NaCl solutions and drying at $25^{\circ}C$ and 60 %RH. The polarization resistance $R_p$ and solution resistance $R_s$ were monitored by AC impedance technique. From the obtained $1/R_p$ and $1/R_s$ values, the corrosion rate of the coatings and the Time of Wetness (TOW) were estimated, respectively. Effects of chloride ions and TOW on the corrosion rates of Zn, Zn-5%Al, Zn-55%Al coatings and appearance of red rust (onset of underlying steel corrosion) under wet-dry cycles are discussed on the basis of the corrosion monitoring data.

• 한국응용곤충학회지
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• 제17권3호
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• pp.139-142
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• 1978

적성병균에 감염된 배나무 잎에서 건전부위, 병반인접부위 및 병반부위별로 몇가지 가수분해효소의 활성을 측정한 결과는 다음과 같다. 1. Cellulase (Cx), Invertase 및 $\beta-amylase$의 활성은 감염부위에서 보다 건전부위에서 더 높았고 모두 pH 7.0부근인 중성측에서 최대활성이 나타났다. 2. Pectinmethylesterase, Polygalacturonase 및 Phosphatase의 활성은 병반인접부위에서 높았다. 3. Pectinmethylesterase의 활성은 건전부위와 병반 및 그인접부위 간에 pH에 따라 심한 활성차리가 인정되었다.

• 고려인삼학회:학술대회논문집
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• 고려인삼학회 1987년도 Proceedings of Korea-Japan Panax Ginseng Symposium 1987 Seoul Korea
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• pp.89-107
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• 1987

For the elucidation of significance of saponin as quality criterion of ginseng ginsenoside content(GC) and ginsenoside pattern similarity(GPS) by simple correlation were investigated in relation to red ginseng quality factors, age, plant part, harvest season, mineral nutrition, soil physical characteristics, growth light and temperature, shading material, growth location, physiological disease and crop stand through survey of ginseng plantstions, field experiments, water culture and phytotron experiments. Effect of tissue culture was also reviewed. GC was negatively correlated with good quality of red ·ginseng and positively with bad quality. Age did not show any consistency with GC but GPS was less with the increase of age difference. GPS was less or not significant between taproot that is lowest in GC and epidermis highest, and significant between leaf and taproot. Harvest season marked with the lowest GC and Pattern was also different. Nutrient imbalance, the increase of hazardous soil nutrient and physical condition to growth increased GC, but GPS was little different. The higher the growth lights intensity and temperature the higher the GC but GPS was little changed. Root rust increased GC, but root scab decreased it. Sponge-like and inside cavity phenomena increased GC. Ginsenoside pattern of cultured tissues and rootlet showed great variation. These results strongly indicate that there are optimum saponin content and ginsenoside pattern and that these are accomplished under the optimum growth condition.

• Nuclear Engineering and Technology
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• 제44권8호
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• pp.945-952
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• 2012

The sorption of selenium ions onto iron and iron compounds as a disposal container material and its corrosion products, and onto bentonite as a buffer material, was studied to understand the behaviors of selenium in a waste repository. Selenite was sorbed onto commercial magnetite very well in solutions at around pH 9, but silicate hindered their sorption onto both magnetite and ferrite. Unlike commercial magnetite and ferrite, flesh synthesized magnetite, green rust and iron greatly decreased selenium concentration even in a silicate solution. These results might be due to the formation of precipitates, or the sorption of selenide or selenite onto an iron surface at below Eh= -0.2 V. Red-colored Se(cr) was observed on the surface of a reaction bottle containing iron powder added into a selenite solution. Silicate influences on the sorption onto magnetite and iron for selenide are the same as those for selenite. Even though bentonite adsorbed a slight amount of selenite, the sorption cannot be ignored in the waste repository since a very large quantity of bentonite is used.

• Computers and Concrete
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• 제25권5호
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• pp.447-460
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• 2020

This paper deals with the characteristics of reinforcement corrosion in concrete beams under the influence of sustained loads. The evolution and distribution laws of the reinforcement corrosion were measured periodically over time. The results show that sustained load exhibits a pronounced exacerbating effect on the reinforcement corrosion, and enlarges the nonuniformity level of corrosion as the load level increases. Accompanied with the continuous formation of the rust, the corrosion rate was also observed to be highly nonlinear and time-dependent. Moreover, to visually and quantitatively analyze the distribution of reinforcement corrosion, the 3D scanning technology combined with the probability statistics analysis was adopted, and the observed nonuniformity can be well described by the Gumbel distribution. Finally, an approach based on the three-phase spherical model was proposed to estimate the reinforcement corrosion, taking account of the effects of sustained load on the changes of concrete porosity and oxygen diffusivity.

• 한국응용과학기술학회지
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• 제20권4호
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• pp.283-288
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• 2003

Alkaline powder cleaning agents (APCAs) were prepared by blending of $Na_2CO_3$ tetrasodium pyrophosphate (TSPP). sodium orthosilicate (Na-OSi), Na-dioctyl sulfosuccinate (303C), Demol C, and MJU-100A (100A). The physical properties of APCAs tested with steel specimen showed the following results. The cleaning powers of APCA-6 ($Na_2CO_3$ 250g/TSPP 70g/Na-OSi 40g/303C 60g/Demol C 50g/100A 30g mixture) for press-rust preventing oil was 97% and 98% degreasing at 2wt%, $70^{\circ}C$ and $90^{\circ}C$, respectively; for Quenching oil, the cleaning power of APCA-6 was 95% degreasing at 2wt% and $70^{\circ}C$. From the results, it was ascertained that APCA-6 exhibited a good cleaning power. Also low foaming power tests proved that the APCA-6 maintained good defoaming effect.

• 한국강구조학회 논문집
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• 제12권2호통권45호
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• pp.177-185
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• 2000

본 논문에서는 대기 중에 폭로한 내후성강재의 고장력볼트 마찰이음부 미끄럼계수 평가를 위한 실험연구를 수행하였다. 표면 상태는 흑피 부착된 시험체와 숏브라스트로 흑피를 제거한 시험체를 각각 3개월 및 6개월 폭로한 후 수동솔질, 전동솔질 및 청소하지 않은 표면 등을 고려하였다. 또한, 6개월 폭로 시험편의 각 표면 상태에 대하여 600 시간 동안 볼트축력 감소율을 측정하였다. 실험으로부터 모든 시험체에서 폭로 기간에 따라 미끄럼 계수는 증가하였으며 흑피부착 표면을 전동솔질로 청소한 경우를 제외하곤 모두 0.6 이상의 값을 보였다. 볼트 축력 감소율 역시 초기 비폭로 시험체에 비해 폭로한 시험 체에서 증가하였으며 최대 감소율은 약 10%에 이르렀다.