• Title/Summary/Keyword: soil materials

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Review and Comparative Analysis of Forest Biomass Estimation Using Remotely Sensed Data: from Five Different Perspectives (원격탐사자료를 이용한 국외 산림 바이오매스 추정 현황 및 비교분석: 다섯 가지 관점에서의 고찰)

  • Cho, Kyung-Hun;Heo, Joon;Jung, Jae-Hoon;Kim, Chang-Jae;Kim, Kyung-Min
    • Journal of Korean Society for Geospatial Information Science
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    • v.19 no.1
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    • pp.87-96
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    • 2011
  • Carbon emissions and storages that are strongly related to global warming has have emerged as one of the important issues while many governments and researchers have been interested in climate change and pollution. In this regards, forest biomass estimation is quite importance since forest biomass works as an important medium of the global carbon cycle between the atmosphere and soil. Forest biomass estimation through field survey needs lots of time and labors, and has accessibility issues. Hence, many researchers have focused on the forest biomass approaches based on remotely sensed data. This research comprehensively reviewed forty one international studies using remote sensing data according to five different categories (i.e., location of study area, size of study area, biome, used remote sensing data, and estimation technology). It would be expected that the results of this study can be used for suggesting domestic research directions; domestic research in this field is at the beginning stage in terms of level of technologies and useful materials. As results, 39% out of the reviewed studies used the areas located in North America. 59% out of the researches dealt with small size of the study areas (less than 3,600km2). In case of biome, around 30% of the studies focused on the boreal/taiga areas. Moreover, 35% and 16% of the studies were carried out using Landsat series and Lidar data, respectively. Finally, regression analysis method was most frequently used for forest biomass estimation by 71% out of 41 studies.

Behavior of Geotextile Tube Composite Structure by 2-D Limit Equilibrium and Plane Strain Analysis (2차원 한계평형 및 평면변형해석을 통한 지오텍스타일 튜브 복합구조물의 거동분석)

  • Shin, Eunchul
    • Journal of the Korean GEO-environmental Society
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    • v.7 no.6
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    • pp.13-22
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    • 2006
  • The geotextile have been used in filtration and drainage for over 30 years in many applications of civil and environmental projects. Geotextile tube is compound technology of filtration and drainage property of geotextile. Geotextile have been used for various types of containers, such as small hand-filled sandbags, 3-dimensional fabric forms for concrete paste, large soil and aggregate filled geotextile gabion, prefabricated hydraulically filled containers, and other innovative systems involving containment of soils using geotextile. They are hydraulically filled with dredged materials. It have been applied in coastal protection and scour protection, dewatering method of slurry, and isolation of contaminated material. Recently, geotextile tube technology is no longer alternative construction technique but suitable desired solution. This paper presents the behavior of geotextile tube composite structure by 2-D limit equilibrium and plane strain analysis. 2-D limit equilibrium analysis was performed to evaluate the stability of geotextile tube composite structure for the lateral load and also the plane strain analysis was conducted to determine the design and construction factors. Based on the results of this paper, the three types of geotextile tube composite structure is stable. And the optimum tensile strength of geotextile is 151kN/m and maximum pumping pressure is 22.7kN/m.

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Evaluation of Ultimate Bearing Capacity on Granular Compaction Pile Considering Various Stresses in a Ground (지중응력의 변화를 고려한 조립토 다짐말뚝의 극한지지력 평가)

  • Kang, Yun;Yun, Ji-Yeon;Chang, Weon-Ho;Kim, Hong-Taek
    • Journal of the Korean Geotechnical Society
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    • v.20 no.2
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    • pp.115-124
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    • 2004
  • Granular compaction pile has the load bearing capacity of the soft ground increase and has the settlement of foundation built on the reinforced soil reduce. The granular compaction group piles also have the consolidation of the soft ground accelerate and prevent the liquefaction caused by earthquake using the granular materials such as sand, gravel, stone etc. However, this method is not widely used in Korea. The granular compaction piles are constructed by grouping them with a raft system. The confining pressure at the center of bulging failure depth is a major variable in estimating the ultimate bearing capacity of the granular compaction piles. Therefore, a share of loading is determined considering the effect of load concentration ratio between the granular compaction piles and surrounding soils, and the variation of the magnitude of the confining pressure. In this study, a method for the determination of the ultimate bearing capacity is proposed to apply a change of the horizontal pressure considering bulging failure depth, surcharge, and loaded area. Also, the ultimate bearing capacity of the granular compaction pile is evaluated on the basis of previous study(Kim et al., 1998) on the estimation of the ultimate bearing capacity and compared with the results obtained from laboratory scale model tests and DEM numerical analysis using the PFC-2D program.

Bearing Capacity of Strip Footing Adjacent on Cohesionless Slopes (비점착성 사면에 인접한 대상기초의 지지력)

  • Yu, Nam-Jae;Kim, Yeong-Gil;Jeon, Yeon-Jong
    • Geotechnical Engineering
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    • v.13 no.4
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    • pp.37-54
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    • 1997
  • This paper is to investigate the bearing capacity and the failure mechanism of slope subjected to strip surcharges adjassent to embankment slope of sandy soil. Parametric model tests under plain strain condition were performed by changing width of footing, relative density of slope materials, and position of footing from the crest of slopes. For model tests, Jumunjin standard sand was used as the slope material and its relative density was 45% and 70%, respectively. The angle of slope was formed with 1 : 1.5 and 1 2. Rigid model footings, made of aluminuu were used with their widths of 4, 7, 10 and 12cm. For the position of model footing, position ratios, distance of model footing from the crest of slope divided by footing width, were 0, 0.5, 1, 2, 3, 4, 5. Failure mechanism was observed by using ink colored sands and markers inserted in model slopes. Ultimate bearing capacity obtained from tests was analyzed and compared with limit equilibrium method, limit analysis method and empirical equation. Characteristics of load-settlement curves and failure mechanism were also analyzed and compared with the existing theories. Thus, their effects on ultimate bearing capacity of model footing adjacent to slope were assessed.

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The Symbols of the Body Image Expressed in Modern Fashion Design (현대 패션디자인에 표현된 신체이미지의 상징성)

  • 권기영;조필교
    • The Research Journal of the Costume Culture
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    • v.8 no.5
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    • pp.681-706
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    • 2000
  • This study is intended to understand an implication system and significance in the current community which a body image symbolizes by correlating it with fashion that is on the rise as a principal issue in various fields. For this study, the symbolism of the body image was contemplated in terms of philosophy and art, and then on the basis of it, the symbolism of the body image shown in modern fashion design was analyzed through fashion works. The research results are as follows, 1. The manifestation of sex can be taken as the symbolism of the body image which is expressed in modern fashion design. Recently sexual chaos and vagueness such as homosexuality and bisexuality are expressed through a dress and its ornaments. Though displaying sexual characteristics of male and female as they are exposing a sign or a diagram, decorating a part of body or representing sex in garments, uncertain sex identity in modern society is manifested in dress and its ornaments. It is to deny absoluteness regarding sex and emphasize diversity indwelt in human beings, and after all it shows to pursue the human essence. 2. Another symbolism of the body image is body expression as the human race and an ethnic group. The discriminating situations and the restoration of their status appeared in modern fashion too. Moreover, their cultures and issues came to alter the aesthetic standard of body made from a view of the Western white supremacist. Hereupon, fashion trends like ethnic fashion, Orientalism and African look etc. appear according to this tendency, which represents race and national identity and in addition, which signifies to present transcendental human conception embracing alienated human conception. 3. The symbolism of the body image expressed in a body, and a dress and its ornaments as nature can be considered in terms of the concern on environmental contamination and the respect of echo system. Getting away from reigning over, developing and stamping down nature at their will, the human beings pursue unity with nature, which is described in fashion. They are stressing that natural materials and objects such as animal, plant and soil etc. should activily be introduced into fashion and humans are a communal fate group and should reframe their status in nature at last. 4. The body image shown in a body, a dress and its ornaments as technology is transformed and recreated by modern scientific techniques and medical science to show post human conception namely, forthcoming future human conception as a cyborg which loses individual identity. This presents a perfect future human conception with high level of preternatural power but after all, leaves us a task to seek the meaning of human existence in alienation caused by the loss of human identity and existence. In this manner, the moderns crave for perceiving the identity of a natural human being in the current thoughts tendency of the modern times such as postmodernism, post structuralism, deconstructionism, feminism and so on, which build discussions affecting the art and fashion worlds. The categories, like sexual characteristics indwelt in a human body, racial classifications, the natural environment surrounding human beings and development of science, bring out the importance of the internal and external meaning in today's fashion which a human body contains, and present sew human conception in the coming future society.

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Chemosensitization of Fusarium graminearum to Chemical Fungicides Using Cyclic Lipopeptides Produced by Bacillus amyloliquefaciens Strain JCK-12

  • Kim, K.;Lee, Y.;Ha, A.;Kim, Ji-In;Park, A.R.;Yu, N.H.;Son, H.;Choi, G.J.;Park, H.W.;Lee, C.W.;Lee, T.;Lee, Y.W.;Kim, J.C.
    • 한국균학회소식:학술대회논문집
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    • 2018.05a
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    • pp.44-44
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    • 2018
  • Fusarium head blight (FHB) caused by infection with Fusarium graminearum leads to enormous losses to crop growers, and may contaminate grains with a number of Fusarium mycotoxins that pose serious risks to human and animal health. Antagonistic bacteria that are used to prevent FHB offer attractive alternatives or supplements to synthetic fungicides for controlling FHB without the negative effects of chemical management. Out of 500 bacterial strains isolated from soil, Bacillus amyloliquefaciens JCK-12 showed strong antifungal activity and was considered a potential source for control strategies to reduce FHB. B. amyloliquefaciens JCK-12 produces several cyclic lipopeptides (CLPs) including iturin A, fengycin, and surfactin. Iturin A inhibits spore germination of F. graminearum. Fengycin or surfactin alone did not display any inhibitory activity against spore germination at concentrations less than 30 ug/ml, but a mixture of iturin A, fengycin, and surfactin showed a remarkable synergistic inhibitory effect on F. graminearum spore germination. The fermentation broth and formulation of B. amyloliquefaciens JCK-12 strain reduced the disease incidence of FHB in wheat. Furthermore, co-application of B. amyloliquefaciens JCK-12 and chemical fungicides resulted in synergistic in vitro antifungal effects and significant disease control efficacy against FHB under greenhouse and field conditions, suggesting that B. amyloliquefaciens JCK-12 has a strong chemosensitizing effect. The synergistic antifungal effect of B. amyloliquefaciens JCK-12 and chemical fungicides in combination may result from the cell wall damage and altered cell membrane permeability in the phytopathogenic fungi caused by the CLP mixtures and subsequent increased sensitivity of F. graminearum to fungicides. In addition, B. amyloliquefaciens JCK-12 showed the potential to reduce trichothecenes mycotoxin production. The results of this study indicate that B. amyloliquefaciens JCK-12 could be used as an available biocontrol agent or as a chemosensitizer to chemical fungicides for controlling FHB disease and as a strategy for preventing the contamination of harvested crops with mycotoxins.

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Structural and Kinetic Characteristics of 1,4-Dioxane-Degrading Bacterial Consortia Containing the Phylum TM7

  • Nam, Ji-Hyun;Ventura, Jey-R S.;Yeom, Ick Tae;Lee, Yongwoo;Jahng, Deokjin
    • Journal of Microbiology and Biotechnology
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    • v.26 no.11
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    • pp.1951-1964
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    • 2016
  • 1,4-Dioxane-degrading bacterial consortia were enriched from forest soil (FS) and activated sludge (AS) using a defined medium containing 1,4-dioxane as the sole carbon source. These two enrichments cultures appeared to have inducible tetrahydrofuran/dioxane and propane degradation enzymes. According to qPCR results on the 16S rRNA and soluble di-iron monooxygenase genes, the relative abundances of 1,4-dioxane-degrading bacteria to total bacteria in FS and AS were 29.4% and 57.8%, respectively. For FS, the cell growth yields (Y), maximum specific degradation rate ($V_{max}$), and half-saturation concentration ($K_m$) were 0.58 mg-protein/mg-dioxane, $0.037mg-dioxane/mg-protein{\cdot}h$, and 93.9 mg/l, respectively. For AS, Y, $V_{max}$, and $K_m$ were 0.34 mg-protein/mg-dioxane, $0.078mg-dioxane/mg-protein{\cdot}h$, and 181.3 mg/l, respectively. These kinetics data of FS and AS were similar to previously reported values. Based on bacterial community analysis on 16S rRNA gene sequences of the two enrichment cultures, the FS consortium was identified to contain 38.3% of Mycobacterium and 10.6% of Afipia, similar to previously reported literature. Meanwhile, 49.5% of the AS consortium belonged to the candidate division TM7, which has never been reported to be involved in 1,4-dioxane biodegradation. However, recent studies suggested that TM7 bacteria were associated with degradation of non-biodegradable and hazardous materials. Therefore, our results showed that previously unknown 1,4-dioxane-degrading bacteria might play an important role in enriched AS. Although the metabolic capability and ecophysiological significance of the predominant TM7 bacteria in AS enrichment culture remain unclear, our data reveal hidden characteristics of the TM7 phylum and provide a perspective for studying this previously uncultured phylotype.

Properties of Harmful Substances Absorption Eco-friendly Artificial Stone Containing Basalt Waste Rock (현무암 폐석을 첨가한 유해물질 흡착 친환경 인조석재의 특성)

  • Pyeon, Su-Jeong;Gwon, Oh-Han;Kim, Tae-Hyun;Lee, Sang-Soo
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.4 no.4
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    • pp.431-438
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    • 2016
  • Recently, Both rapid economic growth and high-quality native finishing materials demand in buildings such as local infrastructure facilities and cultural facilities have increased along with local quarries. So, increasing local quarries and environmental pollution occurred in quarries get the eyes to damaged area of the surroundings. As an example, carcinogen such as solid formed to fixing asbestos and dust have damaged to local resident. Especially, Radon gas released from asbestos can exist everywhere on earth, released soil and rock as radioactive substances, can be caused lung cancer followed by a smoking. When pollution source to indoor air quality that lacking ventilation rate of the residential building moved in a cycle, human responses such as headache, dizziness, etc. get appear, so on it threatened resident's physical condition. Thus, we need to urgent attention to reduction harmful substance. In the case of radon gas of the pollution source to indoor air quality in housing, it has characteristic that keep on going through half-life released from source, we need to control radon gas source than source removal. We set on vermiculite addition ratio to 10% which has harmful substances adsorption performance, proceed experiment to basalt waste rock addition ratio 50, 60, 70, 80(%). The result of an experiment, based on 'KS F 4035, precast terrazzo', we can be obtainable in the best terrazzo at basalt waste rock addition ratio 70%.

Mechanical Properties of Recycled Powder mixing Concrete (재생미분말을 혼입한 콘크리트의 역학적 특성)

  • Lee, Seung-Hwan;Jung, Dae-Jin;Choi, Ik-Chang
    • Proceedings of the Korea Concrete Institute Conference
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    • 2008.04a
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    • pp.769-772
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    • 2008
  • The problem of disposing construction waste materials has become a national and social problem. Recycled powder generated in the process of making aggregate, and the recycled powder is land-filled in its entirety. Results of toxicity testing of recycled power show that it contains base-pair substituent mutagenicity. As recycled powder is disposed of as landfill, it can cause secondary contamination such as soil and underground water contamination. There has been very little research made on recycled powder. This study has examined the utilization of concrete mixture by using recycled powder in a mixture instead of cement and compared and analyzed the characteristics of dynamics and workability. This study has examined the application of recycled powder in concrete. Depending on the replacement rate and workability, test piece was manufactured using different mixing rate by CP, WCP, PCP. The CP was used to examine the physical property of concrete and characteristics its dynamics. The letters W of WCP and P of PCP are the initials of water and mixture. They were made using the standard mixing ratiosemphasizing the workability to determine the characteristic of dynamics of concrete based on the mixing ratio of recycled powder. With the increase in the replacement rate, CP had very little change in the strength. But with the decline of slump, the workability was not good. The result of manufacturing WCP and PCP using the standard mixing ratio showed that WCP had a drop in strength compared to the plain. PCP had almost the same value as the plain only when the replacement rate was 10%. When it was higher than that, a reduction in strength was observed.

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Characteristic of Permeability with the Sand, Calcium Bentonite and Solidifier Mixtures according to Selective Reaction of TCE (트리클로로에틸렌(TCE) 선택적 반응에 따른 모래, 칼슘-벤토나이트 및 겔화제 혼합차수물의 투수 특성)

  • Yun, Seong Yeol;Choi, Jeong Woo;Oh, Minah;Lee, Jai-Young
    • Journal of the Korean Geosynthetics Society
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    • v.19 no.1
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    • pp.25-33
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    • 2020
  • To improvement the swelling characteristics of the existing cutoff wall against the moisture, the permeability of the sand, calcium bentonite and solidifier mixture according to the contact with trichloroethylene (TCE) was evaluated. Characteristics analysis and the permeability test of the research materials were performed. The permeability was decreased as the mixing ratio of the calcium bentonite was increased and it was increased as the mixing ratio of the solidifier was increased. In conclusion, when mixing 15% of calcium bentonite and more than 30% of solidifier, the permeability coefficient in the underground water movement was analyzed as more than α × 10-4 cm/sec showing that it does not block the underground water movement. In addition, as the permeability coefficient of mixtures after TCE reaction was analyzed as less than α ×10-7 cm/sec, it satisfied the condition of blocking layer (less than 1.0 × 10-6 cm/sec). Therefore, the calcium bentonite and solidifier can be utilized as barrier that showing the characteristic of percolation ability conversion in soil and underground water contaminated with TCE.