• Title/Summary/Keyword: Alternative cover material.

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A Study on the alternative daily cover and envelop materials of PS Ball slag (PS Ball 풍쇄슬래그의 일일복토재 및 집배수재 재활용을 위한 연구)

  • Kim, Sang-Keun;Chung, Ha-Ik;Song, Bong-Jun;Chang, Won-Seok
    • Proceedings of the Korean Geotechical Society Conference
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    • 2005.03a
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    • pp.1408-1411
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    • 2005
  • The purposes of daily cover are to control odor and volatile organic compound emissions, to control litters, to mitigate rainfall infiltration. Under usual operation of landfill, the soil layer of 15cm thick is used for daily cover, but about $20{\sim}$25% of landfill capacity is consumed by daily cover volume. Considering our limited land and difficulty in getting landfill site, developing an alternative daily cover material which usually occupies much less volume than soil will be very significant. Also, if we can use waste material for alternative daily cover, we can get additional benefit of recycling waste.

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Flyash를 이용한 일일복토재의 포설 사례 연구

  • 박상현;한완수;이재영
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2002.09a
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    • pp.386-389
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    • 2002
  • It may be necessary to apply a daily fever to operate the municipal solid waste landfill. The daily cover helps to control nuisance factors such as the escape of odors, dusts and airborne emissions, and can control the population of disease vectors. Also it may be reduce the infiltration of rain, decreasing the generation of leachate and the potential for surface water and groundwater contamination. Because of its usual availability and traditional usage as the municipal solid waste landfill, soil remains as the most common daily cover material. However, soil tends to reduce the volume of dumping waste c;3pacity in the landfill, it also reduces a period of using in the landfill. Therefore, it is necessary to research about Alternative Daily Cover Materials (ADCMs) because of the limitation of landfill sites. Recently, The types of ADCMs are classified into geosynthetics, forms, spray-ons, indigenous materials. In this study, the authors have tested the spray type of Alternative Daily Cover(ADC) using by flyash, alum with cement. The development. of ADCMs will be highly effective in terms of prolongation using landfill.

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The Evaluation on In-Situ Adaptability of Mono-layer Landfill Final Cover System (단층형 매립지 최종복토시스템의 현장 적용성 평가)

  • Yu, Chan;Yun, Sung-Wook
    • Journal of The Korean Society of Agricultural Engineers
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    • v.48 no.5
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    • pp.73-80
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    • 2006
  • The mono-layer cover system is composed of soils only as a filling material and various plants are planted on the surface to control the water balance in the cover system. In this paper, the mono-layer cover system was considered as an alternative landfill final cover system and developed a model that could utilize industrial by-product (especially, coal ash & phosphogypsum) as additive filling materials. The mixture of granite soil, coal ash, and phosphogypsum was placed as a cover material in a box constructed with cement. Laboratory tests were carried out to investigate the environmental effect on the utilization of coal ash & phosphogypsum and to determine the mxing ratio of each materials. In the leaching test, all materials showed lower heavy metal concentration than the threshold values of regulation. The optimum mixing ratio of materials which was applied to field model test was determined to soil (4) : coal ash (1) : phosphogypsum (1) on the volume base. Field model tests were continued from February to July, 2004 in the soil box that was constructed with cement block. It was verified that coal ash and phospogypsum mixed with soil was to be safe environmentally and the water balance of mono-layer cover system was reasonable.

In Situ Bio-barrier Formation using Bacteria/Fungi-Soil Mixture (Bacteria/Fungi 혼합토를 이용한 현장 Bio-barrier 형성)

  • 김건하;송영우;구동영
    • Proceedings of the Korean Geotechical Society Conference
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    • 2000.03b
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    • pp.489-495
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    • 2000
  • When microorganisms such as bacteria and fungi are injected into porous medium such as soils along with appropriate substrate and nutrients, biomass retained in the soil pore. Soil pore size and shape are varied from the initial condition as a result of biofilm formation, which make hydraulic conductivity reduced. In this research, hydraulic conductivity reduction was measured after microorganism are inoculated and cultured with synthetic substrates and nutrients. Biomass-soil mixture was evaluated its applicability to the field condition as an alternative liner material in landfill by measuring hydraulic conductivity change after repetitive freeze-thaw cycles.

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Weight reduction and strengthening of marine hatch covers by using composite materials

  • Tawfik, Basem E.;Leheta, Heba;Elhewy, Ahmed;Elsayed, Tarek
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.9 no.2
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    • pp.185-198
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    • 2017
  • The application of composites as an alternative material for marine steel hatch covers is the subject of this study. Two separate approaches are considered; weight reduction approach and strengthening approach. For both approaches Finite Element Analysis (FEA) was performed using ANSYS software. Critical design parameters of the composite hatch cover and FEA are discussed in details. Regarding the weight reduction approach; steel hatch covers of a bulk carrier were replaced by composite covers and a weight reduction of 44.32% was achieved leading to many benefits including fuel saving, Deadweight Increment and lower center of gravity of the vessel. For the strengthening approach; the foremost hatch cover was strengthened to withstand 150% of the load required by IACS for safer navigation while no change in weight was made between the steel and composite covers. Results show that both approaches are feasible and advantageous.

The Evaluation on the Environmental Effect of Coal-Ash and Phosphogypsum as the Evapotranspiration Final Cover Material (증발산 원리를 이용한 매립장 최종 복토공법의 복토재로서 석탄재와 인산석고의 환경적 영향 평가)

  • Yu, Chan;Yang, Kee-Sok
    • Journal of the Korean GEO-environmental Society
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    • v.6 no.1
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    • pp.15-21
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    • 2005
  • In this study, the utilization of coal-ash and phosphogypsum was considered as the evapotranspiration final landfill cover(ET cover) material. Cover material considered was the mixture of the weathered granite soil, coal-ash and phosphogypsum and so we sequentially performed the leaching test, column test and field model test to investigate the environmental effects of mixtures of coal-ash and phosphogypsum. In the leaching test, all materials had lower heavy metal concentration than the regulated threshold values. The column test and the review of related regulations were carried out to determine the optimum mixing ratio(OMR) and OMR was soil(4):coal-ash(1): phosphogypsum(1) on the volume base, which was applied to field model test. Field model tests were continued from February to June, 2004 in the soil box that was constructed with cement block. It was verified that coal-ash and phospogypsum mixed with soil was safe environmentally and the mixture of both wastes could improve the water retention capacity of cover materials.

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Permeability Reduction of Soils by Biomass Injection (미생물 균체의 주입을 통한 토양의 투수계수 감소)

  • 송영우;김건하;구동영
    • Journal of the Korean Geotechnical Society
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    • v.15 no.6
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    • pp.273-283
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    • 1999
  • When microorganism is injected into porous medium such as soils, biomass is retained in the pore. Soil pore size and shape are varied from the initial condition as a result of biofilm formation which makes hydraulic conductivity reduced and friction rate between soil aggregates increased. In this research, hydraulic conductivity reduction was measured after microorganism are inoculated and cultured with synthetic substrate and nutrient. In addition, this research evaluated the applicability of biomass-soil mixture to the field condition as an alternative cover material in landfill by measuring hydraulic conductivity change after repetitive freeze-thaw cycles. Hydraulic conductivity of silty soil decreased by approximately 1/50 after biomass inoculation and cultivation. Biofilm attached on soil aggregates is resistant to acidic or basic condition. After repetitive freeze-thaw cycles, however, hydraulic conductivity increase implies that biomass clogging can be impaired.

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Usefulness of Partial Muscle Flaps and Combination Method for Coverage of Prosthetic Material in Chest Wall Reconstruction (흉벽 재건에서 합성 물질의 피복을 위한 부분 근피판 조합의 효용성)

  • Ryoo, Suk-Tae;Pyon, Jai-Kyong;Lim, So-Young;Mun, Goo-Hyun;Bang, Sa-Ik;Oh, Kap-Sung
    • Archives of Plastic Surgery
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    • v.38 no.3
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    • pp.228-234
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    • 2011
  • Purpose: Reconstruction of chest wall has always been a challenging problem. Muscle flaps for chest wall reconstruction have been helpful in controling infection, filling dead space and covering the prosthetic material in this challenge. However, when we use muscle flaps, functional and cosmetic donor site morbidities could occur. The authors applied and revised various partial muscle flaps and combination use of them to cover the prosthetic material for the chest wall reconstruction and evaluated the usefulness of partial muscle flaps. Methods: This study included 7 patients who underwent chest wall reconstruction using partial muscle flap to cover prosthetic material from 2004 to 2008. The pectoralis major muscle was used in anterior 2/3 parts of it leaving lateral 1/3 parts of it. The anterior 2/3 parts of the pectoralis major muscle were used while lateral 1/3 parts were left. In case of the rectus abdominis muscle flap, we used upper half of it, or we dissected it around its origin and then advanced to cover the site. The latissimus dorsi muscle flap was elevated with lateral portion of it along the descending branch of the thoracodorsal artery. If single partial muscle flap could not cover whole prosthetic material, it would be covered with combination of various partial muscle flaps adjacent to the coverage site. Results: Flap coverage of the prosthetic material and chest wall reconstructions were successfully done. There occurred no immediate and delayed post operative complications such as surgical site infection, seroma, deformity of donor site and functional impairment. Conclusion: When we use the muscle flaps to cover prosthetic material for chest wall reconstruction, use of the partial muscle flaps could be a good way to reduce donor site morbidity. Combination of multiple partial flaps could be a valuable and good alternative way to overcome the disadvantages of partial muscle flaps such as limitation of volume and size as well as flap mobility.

Applicability of SRSL(Self-Recovering Sustainable Liner) to the Landfill Final Cover System (SRSL(Self Recovering Sustainable Liner)재의 매립지 최종복토층에 대한 활용성 검토)

  • Kwon, Oh-Jung;Seo, Min-Woo;Hong, Soo-Jung;Park, Jun-Boum;Park, Soo-Young
    • Proceedings of the Korean Geotechical Society Conference
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    • 2004.03b
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    • pp.453-460
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    • 2004
  • To prevent penetration of rainwater into the landfill site is the main purpose of the final cover in landfill sites. Conventional designs of landfill covers uses geotextiles such as geomembrane and GCL, and clay liners to lower the permeability of final covers of landfill sites. However, differential settlement and the variation of temperature in landfill sites cause the development of cracks or structural damage inside the final cover and it is also difficult to obtain clay - the main material of the compacted clay liner in Korea. Thus the former final cover system that suggests geomembrane and GCL or compacted clay liner has several limitations. Therefore, an alternative method is necessary and one of them is the application of SRSL(self-Recovering Sustainable Liner) material. SRSL is two different layers consist of individual materials that react with each other and form precipitates, and with this process lowers the permeability of the landfill final cover. SRSL generally is made up of two layers, so that when a internal crack occurs the reactants of the two layers migrate towards the crack and heal it by forming another liner. In this study the applicability of SRSL material for landfill final cover was examined by performing; (1) jar test to verify the formation of precipitate in the mixture of each reactants, (2) falling head test considering the field stress in order to confirm the decrease of permeability or prove that the hydraulic condctivity is lower than the regulations, (3) compression tests to judge weather if the strength satisfies the restricts for landfills, (4) freeze/thaw test to check the applicability of SRSL for domestic climate. In addition, the application of waste materials in the environmental and economical aspect was inspected, and finally the possibility of secondary contamination due to the waste materials was examined by performing elution tests.

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Evaluating the recovering capacity of cracked SRSL in the landfill final cover (SRSL(Self Recovering Sustainable Liner)재의 매립지 최종복토층에서균열 손상 시 치유 능력 검토)

  • Baek, Hyun-Uk;Ha, Min-Ki;Kwon, Oh-Jung;Park, Jun-Boum
    • Proceedings of the Korean Geotechical Society Conference
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    • 2005.03a
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    • pp.1412-1419
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    • 2005
  • Preventing the infiltration of rainwater into the landfill site is the main purpose of the final cover in landfill sites. Compacted clay layer or geomembrain have been used as a conventional landfill final cover. But they have several disadvantages when damages might occur due to puncturing, differential settlement and desiccation or freeze and thaw. For this reason, as an alternative method SRSL(Self Recovering Sustainable Liner) has been developed. Adopting the precipitation reaction of two chemical material, by forming precipitates that fill the pores, and lower the overall permeability of the liner. The advantage of this method is that when fracture of the liner occurs the remaining reactants of the two layers form precipitates that fill the fracture and recover the low permeability of the liner. In this study, the recovering ability of the SRSL with a crack due to the seasonal variation or differential settlements was investigated by permeability tests. And in order to estimate the durability of the SRSL after freeze/thaw and desiccation, uniaxial compression strength tests were performed.

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