• 한국주거학회논문집
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• 제16권5호
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• pp.75-81
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• 2005

The purpose of this study is to shed light on the field dynamics of 'lived space' in the light of our intuitive experiential contents by way of investigating three properties of space. While finding inspirations in the field theory of modern physics, investigation of our intuitive responses to the physical and spatial environment leads us to a coherent view of matter and space. We find then that our lived world is more than a system of inert matter; it is a dynamic environment of life in which feeling and mood, spiritual meaning and value, are perpetually infused with matter. Any concept of space, if it is to be meaningful to lift has to somehow acknowledge this fact. Empty space and matter cannot be conceived as mutually exclusive and independent as in classical physics. Rather they should be seen as two different manifestations of an underlying dynamism which permeates the world. The 'properties' of space can only be understood in terms of the 'impact' of material presence. The object cannot be seen as an isolated entity, but the 'conditioning' of its surrounding space has to be understood as an integral part of its being. Lived space can thus be viewed as an emotionally charged field, or a field of emotional energy, whose properties may be described in terms of concentration, mobility and resonance.

• 한국물환경학회지
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• 제23권4호
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• pp.482-489
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• 2007

Fluorescence properties and carbohydrate content were investigated using ultrafiltrated size fractions of dissolved organic matters (DOM) originated from different sources. The materials included a treated sewage, an algal organic matter, and a soil leachate, all of which are major constituents of dissolved organic matter in a typical urban river. Four different size fractions were separated from the three sources of each DOM. The size distribution demonstrated that a higher molecular weight fraction was more present in soil leachate compared to two other source DOMs. A higher content of carbohydrates was observed in the following order - algal DOM > treated sewage > soil leachate. A wide range of specific UV absorbance was observed from size fractions of a single source DOM, indicating that aromatic carbon structures are heterogeneously distributed within one source of DOM. The structural heterogeneity was the most pronounced for the soil leachate. The fluorescence index ($F_{450}/F_{500}$) of the treated sewage was similar to that (2.0) typically obtained from autochthonous DOM, suggesting that the treated sewage exhibited autochthonous organic matter-like properties. No protein-like fluorescence intensities were observed for all of the soil leachate size fractions whereas they were observed with two other source DOMs. Based upon the fluorescence peak ratios from fluorescence excitation-emission matrix (EEM), two discrimination indices could be suggested to distinguish three different source DOMs. It is expected that the suggested discrimination indices will be useful to predict the sources of DOM in a typical urban river affected by treated sewage.

• Elastomers and Composites
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• 제58권4호
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• pp.161-172
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• 2023

Because particulate matter has emerged as a major contributor to air pollution, the tire industry has conducted studies to reduce particulate matters from tires by improving tire performance. In this study, we compared the conventional blending method, in which rubber, filler, and additives are mixed simultaneously, to the Y-blending method, in which masterbatches are blended. We manufactured carbon black (CB)-filled natural rubber (NR)/butadiene rubber (BR) blend and silica-filled epoxidized NR/BR blend compounds to compare the effects of the two blending methods on the physical properties of the compounds and the amount of particulate matter generated. The Y-blending method provided uniform filler distribution in the heterogeneous rubber matrix, improved processability, and exhibited low rolling resistance. This method also improved physical properties owing to the excellent filler-rubber interaction. The results obtained from measuring the generation of particulate matter indicated that, the Y-blending method reduced PM_2.5 particulate matter generation from the CB-filled and silica-filled compounds by 38% and 60%, and that of PM₁₀ by 29% and 67%, respectively. This confirmed the excellence of the Y-blending method regarding the physical properties of truck bus radial tire tread compounds and reduced particulate matter generated.

• 한국토양환경학회지
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• 제4권1호
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• pp.119-126
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• 1999

This study was carried out to estimate the effect of forest fire on physical and chemical properties of soil The forest fire was in April 1995 at Kongju of Chungnam. Soil samples were collected at 0~5cm, 5~10cm, and 10~20cm soil depths in September 1998 from the burned and unburned sites. Soil organic matter concentrations at 0~5cm and 5~10cm soil depths were significantly greater in unburned site than in burned site. Soil concentrations were greater in unburned site than in burned site at all soil depths. Cation exchange capacity was significantly higher in unburned site than in burned site at 0~5cm soil depth. There were no differences in available soil P, exchangeable soil K, Ca, and Mg, and pH of soil between burned and unburned sites. Soil water content at 0~5cm soil depth was significantly greater in unburned site than in burned site. Bulk density at 0~5cm soil depth was significantly higher in burned site than in unburned site. Forest fire had an adverse effect on physical and chemical properties of soil in this study, Burning of vegetation and forest 리oor organic matter in burned site may reduce organic matter supply to soil and increase soil erosion. Consequently, forest fire may have adverse influence on long-term site productivity.

• 한국토양비료학회지
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• 제8권1호
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• pp.19-23
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• 1975

답토양(畓土壤)에 유기물(有機物)을 연용(連用)함으로써 토양(土壤)의 이화학적성질(理化學的性質)에 미치는 영향(影響)을 구명(究明)하기 위(爲)하여 20년간(年間) 퇴비(堆肥)를 시용(施用)한 조립질토양(粗粒質土壤)의 시료(試料)를 채취(採取) 분석(分析)한 결과(結果)는 다음과 같다. 1. 립경조성(粒徑組成)은 퇴비연용구(堆肥連用區)와 무퇴비구간(無堆肥區間)에 차이(差異)가 없었으나 수리전도도(水理傳導度), 수중침정용적(水中沈定容積)은 퇴비연용구(堆肥連用區)에서 높았다. 2. 가비중(假比重), 토양경도(土壤硬度)는 퇴비연용구(堆肥連用區)에서 낮았으며 공극률(孔隙率)은 높았다. 3. Atterberg 상수(常數)(액성한계(液性限界), 소성한계(塑性限界) 및 소성지수(塑性指數))가 퇴비연용구(堆肥連用區)에서 높았다. 4. 립국분포(粒國分布)는 퇴비연용구(堆肥連用區)에서 뚜렷하게 증가(增加)되지 않았다. 5. pH, 유기물함량(有機物含量), 염기치환용량(鹽基置換用量), 치환성염류(置換性鹽類) 등(等)은 퇴비연용구(堆肥連用區)에서 근소(槿少)하게 높았다.

• Journal of the Optical Society of Korea
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• 제1권2호
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• pp.104-109
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• 1997

The propagation properties of three-dimensional dark spatial solitons having odd ring formation is analyzed numerically in the frame of the (1 + 2)-dimensional nonlinear Schrodinger equation and compared with a pair of odd dark solitons. We discuss the experimental excitation condition of an odd ring dark soliton, which is superimposed on a finite-width background beam, with phase masks.

• 한국환경농학회지
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• 제26권4호
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• pp.279-285
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• 2007

Soil physical properties in organic farming apple orchard were evaluated in relation to conventional farming to better understand the effects of organic farming system on soil quality. Two adjacent apple orchards, matched by soil type, were chosen to ensure the same pedological conditions except management system. Soil samples were collected from middle of two adjacent trees along the tree line at two depths of 5-20 and 20-35 cm in September 2006. Contents of organic matter in organic farming soil were twice as much as those found in soil of conventional farming. The higher level of organic matter in organic farming soil was reflected through a consequent trend in improved soil physical properties. Organic farming produced greater aggregation in >2 mm size and increased aggregate stability. Bulk density was lower by 13% and hence porosity was higher in soils of organic farming as compared with conventional farming. Water holding capacity was significantly greater with organic farming by >17% over conventional farming. The capacity of organic farming to improve soil physical properties can be contributed to the regular application of relatively large amount of organic materials and the sustainable ground-cover managements, mulching with compost and cover crop cultivation.

• Ecology and Resilient Infrastructure
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• 제2권3호
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• pp.247-254
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• 2015

Changes in land-use type can affect soil and water properties in stream ecosystems. This study examined the effects of different land-use types on biogeochemical properties and microbial activities of a stream. We collected water and sediment samples in a stream at three different sites surrounded by varying land-use types; a forest, a radish field and a rice paddy. Nitrogen contents, such as nitrate, nitrite and total nitrogen in the stream water body, showed significant differences among the sampling sites. The highest nitrogen values were recorded at the site surrounded by cropland, as fertilizer runoff impacted the stream. Soil organic matter content in the sediment showed significant differences among sites, with the highest content exhibited at the forest mouth site. These differences might be due to the organic matter in surrounding terrestrial ecosystems. Microbial activities determined by extracellular enzyme activities showed similar values throughout all sites in the water body; however, the activities in the sediments exhibited the highest values near the forest site and mirrored the soil organic matter content values. From these results, we conclude that different land-use types are important factors affecting water and sediment properties in stream ecosystems.

• Kyungpook Mathematical Journal
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• 제58권2호
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• pp.361-375
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• 2018

The object of the present paper is to study super quasi-Einstein manifolds. Some geometric properties of super quasi-Einstein manifolds have been studied. We also discuss $S(QE)_4$ spacetime with space-matter tensor and some properties related to it. Finally, we construct an example of a super quasi-Einstein spacetime.

• Bulletin of the Korean Chemical Society
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• 제25권8호
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• pp.1241-1243
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• 2004