• Title/Summary/Keyword: Soil problems

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Estimation on Bearing Capacity of Waste Landfill Reinforced by Geosynthetics Using Numerical Analysis (수치해석에 의한 토목섬유 보강 폐기물 매립지반의 지지력 평가)

  • Shin, Eunchul;Park, Jeongjun
    • Journal of the Korean GEO-environmental Society
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    • v.9 no.2
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    • pp.67-74
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    • 2008
  • Many industrialized countries of the world have many problems about the reuse of waste landfill area because of the increase of terminated waste disposal landfill. Especially, the effective use of the terminated waste disposal landfill nearby the urban area has been demanded, because of the lack of the usable land. However, in case of the construction of the building on such a landfill, ground settlement and reduced bearing capacity would be occurred without ground stabilization and proper reinforcement. This study is to evaluate the applicability of geosynthetics for the increment of bearing capacity of solid waste landfill ground. A numerical simulation has been undertaken to model a layer of weathered soil overlaying a layer of geosynthetic reinforcement and waste disposal ground. The proposed analytical model can be used to obtain surface settlement characteristic in the two-dimensional deformation related reinforcement.

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Study on Emission Control for Precursors Causing Acid Rain (VI) : Suitability of Aquatic Plant Biomass as a Co-combustion Material with Coal

  • Hauazawa, Atsushi;Gao, Shidong;Sakamoto, Kazuhiko
    • Asian Journal of Atmospheric Environment
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    • v.2 no.2
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    • pp.102-108
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    • 2008
  • In China, energy and environmental problems are becoming serious owing to rapid economic development. Coal is the most problematic energy source because it causes indoor and outdoor air pollution, acid rain, and global warming. One type of clean coal technology that has been developed is the coal-biomass briquette (or bio-briquette, BB) technique. BBs, which are produced from pulverized coal, biomass (typically, agricultural waste), and a sulfur fixation agent (slaked lime, $Ca(OH)_2$) under high pressure without any binder, have a high sulfur-fixation effect. In addition, BB combustion ash, that is, the waste material, can be used as a neutralization agent for acidic soil because of its high alkalinity, which originates from the added slaked lime. In this study, we evaluated the suitability of alternative biomass sources, namely, aquatic plants, as a BB constituent from the perspective of their use as a source of energy. We selected three types of aquatic plants for use in BB preparation and compared the fuel, handling, and environmental characteristics of the new BBs with those of conventional BBs. Our results showed that air-dried aquatic plants had a higher calorific value, which was in proportion to their carbon content, than agricultural waste biomass; the compressive strength of the new BBs, which depends on the lignin content of the biomass, was high enough to bear long-range intracontinental transport in China; and the new BBs had the same emission control capacity as the conventional BBs.

Scale Effects of the Specimen on Shear Strength of sand by Direct Shear Test (직접전단시험에 의한 모래의 전단강도에서 시편의 크기효과)

  • Kim, Joon-Seok;Kim, Ji-Hyun
    • Journal of the Society of Disaster Information
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    • v.15 no.4
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    • pp.590-596
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    • 2019
  • Purpose: An experimental study was conducted on the sand samples for the size effect of the test specimens, one of the problems of the direct shear test. Method: Jumunjin standard sand, a representative sand of Korea, was used as sand sample. The large direct shear test was performed to analyze the shear strength at 50%, 60%, 70%, and 80% relative density, and then the comparative results were compared with the test results of the small direct shear test. Result: It was analyzed that the internal friction angle of the small shear tester tended to be relatively large in the dense region. It was analyzed that the results of the large shear tester tend to be relatively large in the region of medium relative density. Conclusion: The size effect on the samples in the direct shear test on sandy soil was analyzed to be relatively small.

A Study on the Domestic and Foreign Laws connected with Landscape Plant and Planting (조경식물의 식재 관련 국내.외 법제도에 관한 연구)

  • 신익순;김영수
    • Journal of the Korean Institute of Landscape Architecture
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    • v.25 no.1
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    • pp.47-61
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    • 1997
  • This study was conducted to grasp the present condition of the name and the related text of the domestic laws (97 statutes, 1 examination, 1 guide, 3 ordinances, 1 leading case) in force which were connected with landscape plant and planting. Examining the general tree-planting system of America, the related foreign laws(1 constitution, 44 statutes, 31 ordinances, 6 leading cases) were arranged in the name and the text and classified by nations of regional groups and it was considered to the mutual relation with lots of laws which are scattered with the various laws. To examine the points at issue of the related domestic laws and to study the related foreign laws, the remedies for the domestic laws being at issue were proposed. That is : A change of the landscape planting concept, the introduction of the landscape planting cost compared with the total construction cost, the unification of the landscape planting ordinances as the unit of city, the clarification of the completion period for the depect of the replaced trees. putting the conservation and production of the top soil under an obligation the adoption of a licence system for the tree planting within the river area, the introduction of the allotment system for landscape architectural expenses, the encouragement of making a hedge, the settlement for the problems of the trees loss compensation, the necessity for the quality test to the landscape planting works, the intensification of the punitive rules to the illegal felling and planting of the trees in the greenzone area, the application of the Labor Standard Act to the landscape planting laborers. The laws relating to landscape plant and planting are prescribed dispersedly in the many other related laws and it is concluded to be impossible for the legislation of the singular law which is applied uniformly to the department of the tree-planting. Hereafter it should be required to analyze concretely in detail the each text of the related laws by means of the joint studies between the professional landscape architects and the lawyers.

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Retrieval of Key Hydrological Parameters in the Yellow River Basin Using Remote Sensing Technique

  • Dong, Jiang;Jianhua, Wang;Xiaohuan, Yang;Naibin, Wang
    • Proceedings of the KSRS Conference
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    • 2002.10a
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    • pp.721-727
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    • 2002
  • Precipitation evapotranspiration and runoff are three key parameters of regional water balance. Problems exist in the traditional methods for calculating such factors , such as explaining of the geographic rationality of spatial interpolating methods and lacking of enough observation stations in many important area for bad natural conditions. With the development of modern spatial info-techniques, new efficient shifts arose for traditional studies. Guided by theories on energy flow and materials exchange within Soil-Atmosphere-Plant Continuant (SPAC), retrieval models of key hydrological parameters were established in the Yellow River basin using CMS-5 and FengYun-2 meteorological satellite data. Precipitation and evapotranspiration were then estimated: (1) Estimating tile amount of solar energy that is absorbed by the ground with surface reflectivity, which is measured in the visible wavelength band (VIS): (2) Assessing the partitioning of the absorbed energy between sensible and latent heat with the surface temperature, which was measured in the thermal infrared band (TIR), the latent heat representing the evapotranspiration of water; (3) Clouds are identified and cloud top levels are classified using both VIS and TIR data. Hereafter precipitation will be calculated pixel by pixel with retrieval model. Daily results are first obtained, which are then processed to decade, monthly and yearly products. Precipitation model has been has been and tested with ground truth data; meanwhile, the evapotranspiration result has been verified with Large Aperture Scintillometry (LAS) presented by Wageningen University of the Netherlands. Further studies may concentrate on the application of models, i.e., establish a hydrological model of the Yellow river basin to make the accurate estimation of river volume and even monitor the whole hydrological progress.

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Electrokinetic Extraction of Pollutants from the Vicinity of Unregulated Landfill Site (동전기적 추출에 의한 비위생매립지 주변 오염지반의 정화)

  • Lee, MyungHo;Chung, Ha-Ik
    • Journal of the Korean Geosynthetics Society
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    • v.5 no.2
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    • pp.17-22
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    • 2006
  • This paper presents preliminary field investigations on the electrokinetic (EK) remediation coupled with permeable reactive barrier (PRB) system. unregulated and old-fashioned landfills are one of the primary contributors to various contaminated soil problems. In-situ EK remediation technology has been successfully applied to the environs of unregulated landfill site, located in Kyeong-Ki province, Korea. Atomizing slag was adopted as a PRB reactive material for the remediation of groundwater contaminated with inorganic and/or organic substances. From the preliminary investigations, the coupled technology of EK with PRB system would be effecitve to remeidate contaminated grounds without the extraction of pollutants from subsurface due to the reactions between the reactive materials and contaminants.

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An Ecological Reflection on the Food Self-Sufficiency Debate of the Antebellum American South (남북전쟁 이전 미국 남부지방 식량자급 논쟁의 환경사적 검토)

  • Keumsoo Hong
    • Journal of the Korean Geographical Society
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    • v.39 no.2
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    • pp.171-194
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    • 2004
  • The antebellum American South has been characterized by the lingering backward images of plantation, slaves and cotton. The South specializing in the cotton cultivation is compared with the manufacturing East and the breadbasket Midwest. Douglass North who examined the interregional trade assumed that the South up until 1860 relied on the Midwest for the foodstuffs. Statistical and literary evidence, however, disputes the North's model, showing instead that the southern region attained self-sufficiency in foodstuffs at least in the late 1830s or early 1840s. The South's food self-sufficiency is attributable, to a greater extent, to the region-wide environmental movement of scientific agriculture launched to address the aggravating soil problems from cotton monoculture. Diversification and crop rotation lied in the center of the new regime. The new agricultural system combining com, cotton and cowpea ensured the procurement of hoecake, hog meat, and cotton. The most significant outcome of the good farming regime, however, was the enhanced environmental consciousness which came to prevail the best farmer's reckless rush for profit maximization.

Valuable Organic Liquid Fertilizer Manufacturing through $TAO^{TM}$ Process for Swine Manure Treatment

  • Lee, Myung-Gyu;Cha, Gi-Cheol
    • Journal of Animal Environmental Science
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    • v.9 no.1
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    • pp.45-56
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    • 2003
  • $TAO^{TM}$ System is an auto-heated thermophilic aerated digestion process using a proprietary microbe called as a Phototropic Bacteria (PTB). High metabolic activity results in heat generation, which enables to produce a pathogen-free and digested liquid fertilizer at short retention times. TAO$^{TM}$ system has been developed to reduce a manure volume and convert into the liquid fertilizer using swine manure since 1992. About 100 units have been installed and operated in Korean swine farms so far. TAO$^{TM}$ system consists of a reactor vessel and ejector-type aeration pumps and foam removers. The swine slurry manure enters into vessel with PTB and is mixed and aerated. The process is operated at detention times from 2 to 4 days and temperature of 55 to $65^{\circ}C$. Foams are occurred and broken down by foam removers to evaporate water contents. Generally, at least 30% of water content is evaporated, 99% of volatile fatty acids caused an odor are removed and pathogen destruction is excellent with fecal coliform, rotavirus and salmonella below detection limits. The effluent from TAO$^{TM}$ system, called as the "TAO EFFLUX", is screened and has superb properties as a fertilizer. Normally N-P-K contents of screened TAO Efflux are 4.7 g/L, 0.375 g/L and 2.8 g/L respectively. The fertilizer effect of TAO EFFLUX compared to chemical fertilizer has been demonstrated and studied with various crops such as rice, potato, cabbage, pumpkin, green pepper, parsley, cucumber and apple. Generally it has better fertilizer effects and excellent soil fertility improvement effects. Moreover, the TAO EFFLUX is concentrated through membrane technology without fouling problems for a cost saving of long distance transportation and a commercialization (crop nutrient commodity) to a gardening market, for example.

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Vulnerability AssessmentunderClimateChange and National Water Management Strategy

  • Koontanakulvong, Sucharit;Suthinon, Pongsak
    • Proceedings of the Korea Water Resources Association Conference
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    • 2016.05a
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    • pp.204-204
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    • 2016
  • Thailand had set the National Water Management Strategy which covered main six areas in the next 12 years, i.e., by priority: (1) water for household, (2) water for agricultural and industrial production, (3) water for flood and drought management, (4) water for quality issue, (5) water from forest conservation and soil erosion protection, (6) water resources management. However due to the climate change impact, there is a question for all strategies is whether to complete this mission under future climate change. If the impact affects our target, we have to clarify how to mitigate or to adapt with it. Vulnerability assessment was conducted under the framework of ADB's (with the parameters of exposure, sensitivity and adaptive capacity) and the assessments were classified into groups due to their different characteristic and the framework of the National Water Management Strategy, i.e., water supply (rural and urban), water for development (agriculture and others), water disasters (floods (flash, overflow), drought, water quality). The assessments identified the parameters concerned and weight factors used for each groups via expert group discussions and by using GIS mapping technology, the vulnerability maps were produced. The maps were verified with present water situation data (floods, drought, water quality). From the analysis result of this water resources management strategy, we found that 30% of all projects face the big impacts, 40% with low impact, and 30% for no impact. It is clear that water-related agencies have to carefully take care approximately 70% of future projects to meet water resources management strategy. It is recommended that additional issues should be addressed to mitigate the impact from climate risk on water resource management of the country, i.e., water resources management under new risk based on development scenarios, relationship with area-based problems, priority definition by viewpoints of risk, vulnerability (impact and occurrence probability in past and future), water management system in emergency case and water reserve system, use of information, knowledge and technology in management, network cooperation and exchange of experiences, knowledge, technique for sustainable development with mitigation and adaptation, education and communication systems in risk, new impact, and emergency-reserve system. These issues will be described and discussed.

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Molecular biological analysis of Bt-transgenic (Bt-9) rice and its effect on Daphnia magna feeding

  • Oh, Sung-Dug;Yun, Doh-Won;Chang, Ancheol;Lee, Yu-jin;Lim, Myung-Ho
    • Korean Journal of Agricultural Science
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    • v.46 no.1
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    • pp.113-124
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    • 2019
  • Insect-resistant transgenic (Bt-9) rice was generated by inserting mCry1Ac1, a modified gene from the soil bacterium Bacillus thuringiensis, into the genome of a conventional variety of rice (Ilmi). With regard to potential problems such as safety, an evaluation of non-target organisms is necessary as an essential element of an environmental risk assessment of genetically modified (GM) crops. We studied the effects of the Bt-9 rice on the survival of cantor Daphnia magna, a commonly used model organism in ecotoxicological studies. D. magna fed on the Bt-transgenic rice (Bt-9) and its near non-GM counterparts (Ilmi) grown in the same environment (a 100% ground rice suspension). The Bt-9 rice was confirmed to have the inserted T-DNA and protein expression evident by the PCR and ELISA analyses. The feeding study showed a similar cumulative immobility and abnormal response of the Daphnia magna between the Bt-9 rice and Ilmi. Additionally, the 48 h-EC50 values of the Bt-9 and Ilmi rice were 4,400 mg/L (95% confidence limits: 3861.01 - 5015.01 mg/L) and 5,564 mg/L (95% confidence limits: 4780.03 - 6476.93 mg/L), respectively. The rice NOEC (No observed effect concentration) value for D. magna was suggested to be 1,620 mg/L. We conclude that the tested Bt-9 and Ilmi have a similar cumulative immobility for D. magna, a widely used model organism, and the growth of Bt-9 did not affect non-target insects.