• 한국토양비료학회지
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• 제18권2호
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• pp.134-139
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• 1985

정밀토양조사(精密土壤調査) 결과(結果) 밝혀진 315개(個) 토양(土壤)(제주도(濟州道) 60개(個) 토양(土壤) 제외(除外))에 대한 14개(個) 토양특성(土壤特性)을 수집(蒐集)하여 토지이용별(土地利用別), 토심별(土深別), 배수등급별(排水等級別)로 단순상관(單純相關)과 다중상관(多重相關)을 분석(分析)하였다. 토양물리화학적(土壤物理化學的) 성질(性質) 상호관계(相互關係)가 밝혀졌으며 점토함량(粘土含量)과 유기물함량(有機物含量)을 가지고 양(陽)이온 치환용량(置換容量)(CEC)을 계산(計算)할 수 있는 회귀식(回歸式)을 구(求)하였는데 우리나라 점토(粘土)의 CEC는 22me/100g, 유기물(有機物)의 CEC는 103.3me/100g이었다. 보수력(保水力)은 점토함량(粘土含量) 및 유기물(有機物)과 고도(高度)의 유의성(有意性)이 있는 회귀관계(回歸關係)가 성립(成立)되었으며 점토함량(粘土含量)의 회귀계수(回歸係數)는 배수(排水)가 불량(不良)할수록 증대(增大)되었으며 유기물(有機物)의 계수(係數)는 배수(排水)가 약간 양호한 경우가 가장 높았다. 유기물함량(有機物含量)은 토성(土性)과 pH를 가지고 계산(計算)할 수 있었으며 pH가 증가(增加)될수록 유기물함량(有機物含量)은 낮아졌고, pH를 가지고 염기포화도(鹽基飽和度)를 계산(計算)할 수 있었다.

• 유기물자원화
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• 제24권4호
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• pp.69-76
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• 2016

최적의 유기농경지 토양 관리 기준 및 양분 관리 방안을 제시하기 위한 기초자료를 만들기 위해 유기농 인증을 받은 국내 75개 선도 농가를 선정하고, 논 토양에서 이앙 전에 토양 시료를 채취하여 이화학적 특성을 분석하였다. 유기농 토양은 평균적으로 pH 6.2, 유기물 $25.6mg\;kg^{-1}$, 유효 인산 $88.4mg\;kg^{-1}$이나 편차가 크게 나타났으며, 유기농과 관행농을 포함한 전국 규모 토양조사 결과에 비해 pH는 높게 나타났고, 유효 인산은 낮게 나타났으며 유기물은 비슷한 수준을 보였다. 한편 재배년수에 따라 토양 pH와 공극률은 높아지고 있었으며, EC와 유효인산, 용적밀도, 토양 경도는 낮아지고 있었으며, 유기물은 차이를 보이지 않았다. 용적밀도는 표토($R^2=-0.5424$)와 심토($R^2=-0.6429$) 모두 유기물과 부의 상관관계를 나타냈다(p<0.05). 조사 결과 유기물과 유효 인산을 제외한 대부분의 토양 이화학성 인자들에서 토양의 질이 향상되고 있어, 향후 유기물 관리 대책 수립과 유기농업자재로 사용가능한 인산 자재의 발굴이나 개발이 필요한 것으로 사료되었다.

• 한국건설순환자원학회논문집
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• 제2권2호
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• pp.76-82
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• 2006

High-strength, High-durability concrete appearance was embossed by benevolence who quality for each raw material that become factor that is direct in concrete manufacture and the special quality is very important and request properties of matter were also strengthened more. Specially, natural resources of good quality were abundant past in occasion of aggregate and unlike concrete request strength past that the importance was less relatively the quality enemy than cement because is also not big, importance of aggregate quality great veried as concrete strength and request properties of matter about durability are strengthened more on extreme displacement. Mixing four who is original and mixs special quality examination of domestic three Four-Stick Games by Chaechwiwon and age Four-Stick Games and crushed sand examined concrete quality characteristic that use mortar and concrete quality characteristic, special quality of North Korea sun guardian mountain three Four-Stick Games that is imported from the North Korea, North Korea sun guardian mountain three Four-Stick Games etc..

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2003년도 봄 학술발표회 논문집
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• pp.333-338
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• 2003

Although porous concrete is resently used as a pavement at a parking lot, a public squre and a bicycle road, we use without enough examining. most the maintenance of quality for porous concrete is only dealt with strength and color tone. also, there is not yet enough fundamental data about dynamical properties for strength, rate of void and water permeability. even when it is applied to at the scene, it is been a matter. Accodingly in this study analyzed influences through the dynamical properties, combination, and time to vibration. After the analyzation, they investigated peculiar dynamics which are strength of porous concrete, rate of void, and water permeability follow the rate of increase on an admixture making pozzolan reaction. This is purpose to improve capacity of the sidewalk permeable concrete and development of the economical technique for pavement.

• E2M - 전기 전자와 첨단 소재
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• 제10권7호
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• pp.713-718
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• 1997

Polyaniline free standing films cast from N-methyl-2-pyrrolidinone(NMP) solution, camphorsulfonic acid(HCSA), dodecylbenzensulfonic acid(HDBSA), inorganic matter(carbon black, graphite) and metal(silver) were prepared by processings. The properties of these films such as crystallinity, near-infrared absorption spectra and conductivity were investigated. The HCSA and HDBSA doped polyaniline films cast from m-cresol and chloroform solvents showed the metallic property and high crystallinity, respectively. The value of conductivity in the HCSA doped polyaniline film obtained 180 S/cm. We have obtained the value of conductivity 200 S/cm in the metal(silver) doped polyaniline film, which is higher than that of the HCSA doped polyaniline film. The metal(silver) doped polyaniline film shows good properties as a electromagnetic shielding material.

• 한국화재소방학회논문지
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• 제22권3호
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• pp.246-251
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• 2008

일반적으로 유류화재의 경우 상온 상압 하에서 그 물리적 성질과 에너지 특성이 유사한 양상을 나타내나 식용유에 의한 화재발생은 그 특성이 매우 특이하여 취급자의 무지로 인한 화재가 자주 발생하고 있다. 따라서 본 연구에서는 식용유에 대한 에너지 특성과 그 물적 성질을 고찰한 연후 실제 연소실험을 통하여 식용유에 대한 물리적 성질을 검증하였다. 뿐만 아니라 실제 화재사례를 통하여 식용유에 의한 화재원인을 감식하였고 식용유화재 방지를 위한 대응방안을 고찰하여 제시 하였다.

• Journal of Ecology and Environment
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• 제46권4호
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• pp.282-291
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• 2022

Background: The Arctic permafrost stores enormous amount of carbon (C), about one third of global C stocks. However, drastically increasing temperature in the Arctic makes the stable frozen C stock vulnerable to microbial decomposition. The released carbon dioxide from permafrost can cause accelerating C feedback to the atmosphere. Soil organic matter (SOM) composition would be the basic information to project the trajectory of C under rapidly changing climate. However, not many studies on SOM characterization have been done compared to quantification of SOM stocks. Thus, the purpose of our study is to determine soil properties and molecular compositions of SOM in four different Arctic regions. We collected soils in different soil layers from 1) Cambridge Bay, Canada, 2) Council, Alaska, USA, 3) Svalbard, Norway, and 4) Zackenberg, Greenland. The basic soil properties were measured, and the molecular composition of SOM was analyzed through pyrolysis-gas chromatography/mass spectrometry (py-GC/MS). Results: The Oi layer of soil in Council, Alaska showed the lowest soil pH and the highest electrical conductivity (EC) and SOM content. All soils in each site showed increasing pH and decreasing SOC and EC values with soil depth. Since the Council site was moist acidic tundra compared to other three dry tundra sites, soil properties were distinct from the others: high SOM and EC, and low pH. Through the py-GC/MS analysis, a total of 117 pyrolysis products were detected from 32 soil samples of four different Arctic soils. The first two-axis of the PCA explained 38% of sample variation. While short- and mid-hydrocarbons were associated with mineral layers, lignins and polysaccharides were linked to organic layers of Alaska and Cambridge Bay soil. Conclusions: We conclude that the py-GC/MS results separated soil samples mainly based on the origin of SOM (plants- or microbially-derived). This molecular characteristics of SOM can play a role of controlling SOM degradation to warming. Thus, it should be further investigated how the SOM molecular characteristics have impacts on SOM dynamics through additional laboratory incubation studies and microbial decomposition measurements in the field.

• 한국토양비료학회지
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• 제46권3호
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• pp.187-192
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• 2013

This study was carried out to investigate the incorporation effect of green manure crops (GMC) such as the hairy vetch on improvement of soil environment in reclaimed land during silage corn cultivation over the past two years. Plots consisted of conventional fertilization (CF) and incorporation of GMC were divided by addition rate of nitrogen fertilizer (100 kg $ha^{-1}$) with 30 - 100% of non nitrogen fertilization (NNF). Soil physico-chemical properties and growth and yield potential of silage corn were examined. The tested soils showed strong alkali and saline properties with low contents of organic matter and available phosphate while contents of exchangeable sodium and magnesium were high. Soil salinity increased during cultivation of summer crop. However, corn was not affected by salt content. The fresh weight of GMC at incorporation time was 18,345 kg $ha^{-1}$. Content of total nitrogen was 3.09% and the C/N ratio was 12.8 at incorporation time. Fresh and dry matter yield of silage corn were higher in the order of N30% reduction, CF, N50% reduction, N70% reduction, N100% reduction and NNF. Fresh and dry matter yield potential of silage corn for N30% reduction were comparable to those of CF. Bulk density of the soil decreased with incorporation of GMC, while porosity was increased. The soil pH decreased while content of exchangeable calcium, available phosphate, and organic matter increased. Also contents of exchangeable sodium and potassium decreased with incorporation of GMC. The data indicate that incorporation of hairy vetch can improve soil physical and chemical properties and reduce nitrogen fertilizer application especially for alkali saline reclaimed soil such as Saemangeum reclaimed land.

• 환경생물
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• 제18권3호
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• pp.299-305
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• 2000

본 연구는 울릉도 성인봉 주변에 생육하고 있는 너도밤나무군락의 섬조릿대하위군락, 전형하위군락, 일색고사리하위군락에 대한 토양단면 및 토양의 이화학적 특성을 조사하여 울릉도 산림토양의 기초자료를 제공하고, 하위군락별 토양특성의 차이를 조사하기 위해 실시되었다. 하위군락별 토양단면의 형태는 하위군락간에 큰 차이를 보이지 않았다. 하위군락간 토양의 이화학적 요인분석에 있어서 0-10cm 토양 깊이에서 Ca함량에서만 유의적인 차이가 나타났을 뿐, 다른 요인들은 하위군락 간에 큰 차이가 없는 것으로 나타났다. 울릉도 성인봉 주변의 토양특성 중 유기물함량은 0-10cm 토양 깊이에서 평균 21.6%로 매우 높게 나타났으며, 전질소함량도 0-10cm 토양 깊이에서 평균 0.74%로 높게 나타났다. 가비중은 0.43g/cm로 매우 낮게 나타났으며, pH는 평균 4.4로 강한 산성토양의 특성을 나타내어 우리나라의 일반 산림 토양과는 매우 다른 특성을 가지고 있는 것으로 나타났다.

• Journal of Ecology and Environment
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• 제29권5호
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• pp.439-443
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• 2006

Soil properties of Quercus variabilis forest on Youngha valley at Mt. Worak National Park were studied as a part of Korea National Long-Term Ecological Research. Soil sampling was carried out along the 50 cm soil depth with 10cm intervals at every quarter from May 2005 through July 2006. Fresh soil was used for $NH_4{^+}-N,\;NO_3{^-}-N$, and soil water content determination. Remaining soils were air dried in the shade, and then used for determination of soil pH, T-N, T-P and exchangeable cation. Average soil organic matter in top soil was $8.5{\pm}1.2%$ and decreased with soil depth. Bulk density of top soil was $0.82{\pm}0.07g/cm^3 $and increased with soil depth. Soil organic matter and bulk density showed a negative linear correlation ($R^2=0.8464$). Soil pH in top soil and subsoil was similar. T-N, $NH_4{^+}-N,\;NO_3{^-}-N$ and T-P in top soil were $1.9{\pm}0.5mg/g,\;7.3{\pm}1.0mg/kg,\;2.0{\pm}0.4mg/kg\;and\;0.2{\pm}0.05mg/g$, respectively. $K^+,\;Ca^{2+}\;and\;Mg^{2+}$ in top soil were $84.6{\pm}24.4,\;408.8{\pm}137.8\;and\;93.4{\pm}23.0mg/kg$, respectively. They decreased with soil depth. Amounts of organic matter, T-N, $NH_4{^+}-N,\;NO_3{^-}-N$, T-P, $K^+,\;Ca^{2+}\;and\;Mg^{2+}$ in 50 cm soil depth were 250.9, 3.45, 0.025, 0.003, 0.639, 0.181, 0.845 and 0.302 ton $ha^{-1}\;50cm-depth^{-1}$, respectively.