• The Journal of Korean Medicine
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• v.23 no.1
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• pp.61-66
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• 2002

목적： 본 연구는 감미의 작용에 관한 "감보" 등의 이론적 바탕과 약물의 이화학적인 특성을 통해 약효를 어느 정도 예측하고자 하였다. 방법： 한약재의 오미별 이화학적 특성을 구명하기 위하여 수소이온농도(pH), $200^{\circ}C$와 $550^{\circ}C$에서의 질량감소량, 전기전도도, 가시부 및 자외부 흡수 spectrum의 전자전이에 따른 비율, TLC에 의한 주요 성분의 이동율($R_{f}{\;}value$)과 낮은 성분의 이동율($R_{f}{\;}value$)을 측정하였다. 결과： 전탕에 따른 수소이온농도(pH)의 평균은 $5.24{\pm}0.56$이었으며. 약재의 휘발 성분 및 수분 함유량은 $288{\pm}125mg$이었고, 유기물함량의 평균은 $867{\pm}116g$이었으며, 전기전도도의 평균은 $5.46{\pm}0.93S/cm$이었으며, 가시부 및 자외부 흡수 spectrum의 전자전이에 따른 흡광도 비율($\pi{\\rightarrow}\pi^{*}/n{\rightarrow}\pi^{*}$)의 평균은 $3.043{\pm}0.679$이었으며, TLC에 의한 주요 성분의 이동율($R_{f}{\;}value$)의 평균은 $0.553{\pm}0.317$이었고, TLC에 의한 낮은 성분의 이동율($R_{f}{\;}value$)의 평균은 $0.136{\pm}0.122$ 이었다. 결론：약재의 pH는 모두 7보다 낮은 약산성 이었으며, 약재의 휘발 성분 및 수분 함유량은 대략 10~50%정도를 나타내었다. 유기물함량은 대략 80~95%정도를 나타내었다. 전기전도도를 통하여 산약이나 감초는 이온성 물질을 많이 포함하고 있으리라 추정된다.

• Journal of the Korean Geotechnical Society
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• v.18 no.5
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• pp.19-25
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• 2002

In this paper, a laboratory investigation was carried out to change the geotechnical properties of clayey soil with quicklime and rice husk ash for surplus soil strength improvement. The organic content of soils is 8.67%, 6.45% and 3.84% respectively. The geotechnical properties of treated soil were evaluated by a series of laboratory unconfined compression test, consolidation test and etc. The test results indicated that the presence of RHA enhanced the efficiency of lime stabilization. Especially, the increase in strength is very high at the first stage, while the significant improvement occurs in a sample C with organic content of 3.84%. These results can be identified by X-ray diffraction(XRD) and scanning electron microscope(SEM). The results of consolidation test indicate that the presence of RHA with lime reduces the properties of swelling of soil. Thus, it was verified that the addition of RHA is more effective than using only lime for soil stabilization.

• Journal of the Korean GEO-environmental Society
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• v.2 no.1
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• pp.23-30
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• 2001

A Series of laboratory tests were conducted to investigate the engineering characteristics for organic soil widely distributed in Yong-dong region which always makes problems in construction works. Physical characteristics of Yong-dong organic soil area were measured in terms of such categories as nature water content, organic content, specific gravity, liquid limit, and plasticity index. As a result, it was found that nature water content was $50.8^{\circ}-343.5%$, organic content 12.1-42.5%, specific gravity 1.76-2.71, liquid limit 46.6-440.2%, and plasticity index 9.2-557.2%. Also, as consolidation load increases, consolidation coefficient slightly decreases with small up and down. The ratio of secondary consolidation coefficient to compression index is 0.001-0.091 $C_a/C_c$, secondary coefficient tends to increase greatly when organic content is in the range of 11-22%.

• Applied Biological Chemistry
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• v.38 no.3
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• pp.263-268
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• 1995

A study was undertaken to compare degradation patterns of carbofuran in soils between submerged and upland moisture conditions [$3-^{14}C$]Carbofuran was treated in each soils at the rate of 1.0 mg/kg (87.8 kBq $^{14}C/50g$ soil) and the time-course analysis for distribution of radioactivity and degradation products were conducted. Differences in the pathway and rate of carbofuran degradation in soils were observed between submerged and upland moisture conditiona major degradation being hydrolysis at 7-C position and oxidation at 3-C position, respectively. Carbofuran showed less persistence in soils of higher moisture contents A significant portion, $24{\sim}39%$ of the total radioactivity, resided in soils as nonextractable residues at 60 days after treatment The nonextractable radioactivity was mainly located in soil organic matter, fulvic acid, humic acid and humin factions Gel filtration chromatography confirmed the incorporation of carbofuran and its degradation products into the organic matter.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.209-209
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• 2007

Passive Device는 RF Circuit을 제작할 때 많은 면적을 차지하고 있으며 이를 감소시키기 위해 여러 연구가 진행되고 있다. 최근 SoP-L 공정을 이용한 많은 연구가 진행되고 있는데 PCB 제작에 이용되는 일반적인 재료와 공정을 그대로 이용함으로써 개발 비용과 시간 면에서 많은 장점을 가지기 때문이다. SoP-L의 또 하나 장점은 다층구조를 만들기가 용이하다는 점이다. 각 층 간에는 Via를 사용하여 연결하게 되는데, RF Circuit은 회로의 구조와 물성에 따라 특성이 결정되며, 그만큼 Via를 썼을 때 그 영향을 생각해야 한다. 본 연구에서는 multi-layer LCP substrate에 다수의 Via를 chain 구조로 형성하여 전기적 특성을 확인하였다. Via가 70um 두께의 substrate를 관통하면서 상층과 하층의 Conductor을 연속적으로 연결하게 된다. 이 구조의 Resistance와 Insertion Loss를 측정하여, Via의 크기 별 수율과 평균적인 Resistance, RF 계측기로 재현성을 확인하였다. 이를 바탕으로 공정에서의 안정성을 확보하고 Via의 크기와 도금방법에 의한 RF Circuit에서의 영향을 파악하여, 앞으로의 RF Device 개발에 도움이 될 것으로 기대한다. 특히 유기물을 이용한 다층구조의 고주파 RF Circuit에 Via를 적용할 때의 영향을 설계에서부터 고려할 수 있는 자료가 될 것이다.

• Korean Journal of Soil Science and Fertilizer
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• v.30 no.1
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• pp.67-71
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• 1997

To grasp the physico-chemical properties on the management groups of upland soil, the data obtained from the detailed soil survey which conducted from 1964 to 1979 by Agricultural sciences Institute, were analyzed and classified. The clay content in A horizon soil was low in sandy textured and well adapted types and high in heavy clayey type, and that in B horizon was lowest in volcanic ash type and highest in heavy clayey type. High organic matter content was found in the volcanic ash and plateau type. The correlations among soil physico-chemical properties were significant. Especially canon exchange capacity of B horizon soil was highly correlated with the content of available water, clay, silt and organic matter positively.

• Horticultural Science & Technology
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• v.19 no.2
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• pp.179-185
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• 2001

Throughout the world, physical and chemical analyses of horticultural substrates are carried out in many different ways at the different laboratories. In Europe, standardization in properties and analytical methods of horticultural substrates has been a topic over the last decades. As a result, the CEN methods as European standard methods for the physical and chemical analyses were introduced and the final draft was reported in 1999 by CEN(Committee for European Standardization). Dry matter and moisture content are analyzed after drying samples at $103^{\circ}C$. Laboratory compacted bulk density is analyzed by determining the weight of sample compacted in the test cylinder with constant volume. Dry bulk density, particle density, total pore space, water volume, air volume and volume shrinkage are determined by saturating, draining and drying the sample using double rings and a sand suction table. pH and EC are analyzed by 1:5(sample:distilled water) extraction method on the basis of volume. Organic matter and ash content are determined after drying and combusting the samples. Now, CEN methods are being regarded almost as European standard methods. Further study needs to be carried out for universal applicability of the CEN methods to all the substrates.

• Analytical Science and Technology
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• v.22 no.2
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• pp.136-140
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• 2009

To improve the carbon recovery yield of chemical pretreatment in soil and sediment for $^{14}C$ age dating using AMS (Accelerator Mass Spectrometry), we have developed ultrasonic method in chemical pretreatment to replace with stirring method which has been generally used in each step of humic acid extraction for soil and sediment samples. Extraction conditions such as ultrasonic power, temperature and reaction time have been optimized. Six times higher carbon recovery yield could be obtained from low carbon content samples using ultrasonic method. We also compared the dating results by AMS obtained using ultrasonic method with the ages of samples treated by the stirring method. It was found that this new method could be applied to the pretreatment process of low carbon content samples for AMS age dating without effects on the dated ages, and with highly improved carbon recovery yields.

• Journal of Life Science
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• v.20 no.4
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• pp.597-601
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• 2010

Quercus dentata (Thunb. ex Murray) is a major tree found in dry habitats such as limestone areas of Korea. In order to characterize the ecological traits of Q. dentata, we treated Q. dentata saplings under four gradient levels of major environment factors such as light, soil moisture and nutrients for 5 months in a glass house. We then measured and analyzed growth differences among them. Regarding light, aboveground, belowground and plant biomass were highest at a high gradient and lowest at a low one. The root/shoot ratio was highest at the highest light gradient. Regarding moisture, no measured items were significantly affected by the moisture gradient. Regarding nutrients, aboveground, belowground and plant biomass were the highest at a slightly high gradient and the lowest at a gradient lower or higher than this. The root/shoot ratio was not significantly affected by the nutrient gradient. From these results, it was shown that the growth of Q. dentata was more affected by light and nutrients in the environment than moisture.

• The Journal of Engineering Geology
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• v.23 no.4
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• pp.427-434
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• 2013

The leachate from landfill (Andong city) contaminated by foot-and-mouth disease (FMD) contains 44%-50% hydrophilic organic matter, compared with 22%-27% in natural water bodies such as ground water, lake water, and river water. In such natural water, the organic matter content is reduced by the metabolism of microbes in the water. However, in the case of leachate-1 and -2, the concentrations of RTOC (refractory total organic carbon) and RDOC (refractory dissolved organic carbon) were higher than the initial TOC and DOC after burial. According to time elapsed after burial, the concentrations of RTOC and RDOC were decreased below the initial TOC and DOC. In the case of leachate-6 (386 days after burial), RDOC made up 91% of RTOC. This result shows that organic matter in the leachate was composed dominantly of RDOM, most of which was not removed by the metabolism of microbes. Hence, the presence and characteristics of RDOM provide a valuable indication of the effect of leachate on the quality of surface water and ground water. Such information is useful in understanding leachate environments.