• 환경영향평가
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• 제18권6호
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• pp.453-460
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• 2009

In order to provide fundamental data for developing high-grade(high-quality and low-pollution) Refuse Derived Fuel(RDF), we analyzed caloric value and HCl content by Municipal Solid Waste(MSW) type. The caloric value was analyzed using calorimeter and HCl content was analyzed using mercury(II) thiocyanate method. In case of paper type the caloric value was 3,060~3,608kcal/kg and the HCl content was 239~6,135ppm. In case of vinyl-plastics the caloric value was 5,946~9,888kcal/kg and the HCl content was 429~455,771ppm. According to the result of quality assessment by MSW type, the calroric value of vinyl-plastics type was showed higher than that of paper type and in case of HCl content the paper type was showed lower than vinyl-plastics type. So, We mixed paper and plastic wastes. The caloric value of mixed MSW(paper and plastics) was 5,046~9,125kcal/kg and the HCl content was 239~6,135ppm. Also, The caloric value of packaging waste(film-plastics) was 5,982~8,045kcal/kg. Therefore It is possible to develop high-grade Refuse Derived Fuel through suitable mixing of paper and plastic in municipal solid waste.

• Journal of Microbiology and Biotechnology
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• 제32권12호
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• pp.1561-1572
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• 2022

Plastic pollution has been recognized as a serious environmental problem, and microbial degradation of plastics is a potential, environmentally friendly solution to this. Here, we analyzed and compared microbial communities on waste plastic films (WPFs) buried for long periods at four landfill sites with those in nearby soils to identify microbes with the potential to degrade plastics. Fourier-transform infrared spectroscopy spectra of these WPFs showed that most were polyethylene and had signs of oxidation, such as carbon-carbon double bonds, carbon-oxygen single bonds, or hydrogen-oxygen single bonds, but the presence of carbonyl groups was rare. The species richness and diversity of the bacterial and fungal communities on the films were generally lower than those in nearby soils. Principal coordinate analysis of the bacterial and fungal communities showed that their overall structures were determined by their geographical locations; however, the microbial communities on the films were generally different from those in the soils. For the pulled data from the four landfill sites, the relative abundances of Bradyrhizobiaceae, Pseudarthrobacter, Myxococcales, Sphingomonas, and Spartobacteria were higher on films than in soils at the bacterial genus level. At the species level, operational taxonomic units classified as Bradyrhizobiaceae and Pseudarthrobacter in bacteria and Mortierella in fungi were enriched on the films. PICRUSt analysis showed that the predicted functions related to amino acid and carbohydrate metabolism and xenobiotic degradation were more abundant on films than in soils. These results suggest that specific microbial groups were enriched on the WPFs and may be involved in plastic degradation.

• Smart Structures and Systems
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• 제22권4호
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• pp.433-440
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• 2018

Pavements porous concrete is a noble structure design in the urban management development generally enabling water to be permeated within its structure. It has also capable in the same time to cater dynamic loading. During the technology development, the quality and quantity of waste materials have led to a waste disposal crisis. Using recycled materials (secondary) instead of virgin ones (primary) have reduced landfill pressure and extraction demanding. This study has reviewed the waste materials (Recycled crushed glass (RCG), Steel slag, Steel fiber, Tires, Plastics, Recycled asphalt) used in the pavement porous concretes and report their respective mechanical, durability and permeability functions. Waste material usage in the partial cement replacement will cause the concrete production cost to be reduced; also, the concretes' mechanical features have slightly affected to eliminate the disposal waste materials defects and to use cement in Portland cement (PC) production. While the cement has been replaced by different industrial wastes, the compressive strength, flexural strength, split tensile strength and different PC permeability mixes have depended on the waste materials' type applied in PC production.

• 한국환경과학회지
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• 제18권10호
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• pp.1181-1187
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• 2009

Results for application of RDF(Refuse Derived Fuel) to selected wastes in metropolitan and small and medium cities are as follows. The physical characteristics of waste are paper, plastic, food waste, and so on. The proximate analysis in P city showed 20.2% of moisture, 71% of combustible material, and 8.8% of ash on annual average. That in G city showed 31.6% of moisture, 59.5% of combustible material, and 8.9% of ash. Ultimate analysis in P city showed 52.04% of carbon, 7.02% of hydrogen, 28.80% of oxygen, 0.66% of nitrogen, and 0.09% of sulfur. Heating value was 3,363 kcal/kg. Ultimate analysis in G city showed 50.85% of carbon, 6.56% of hydrogen, 29.86% of oxygen, 0.79% of nitrogen, and 0.12% of sulfur. Heating value in the G city was somewhat lower than that in the P city with 2,632 kcal/kg. Thus, application of RDF in metropolitan city was more effective than that in small and medium cities. Heating value in mixture for the P city was lower than that in waste of the volume rate waste charge system alone by 143 kcal/kg. In proximate analysis, moisture, and combustible material were likely to be more adequate to RDF.

• 한국전기전자재료학회논문지
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• 제33권6호
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• pp.505-509
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• 2020

The development of diesel power generation is predominantly geared toward island areas or ships because diesel exhibits weak scale-merit characteristics and power quality problems, which are associated with environmental pollution. However, a new energy paradigm, distribution energy resource (DER), has been emerging as a renewable energy source due to the existing structural problems in waste disposal and complex factors such as the conversion technology of waste emulsified oil (WDF). By combining extended producer responsibility (EPR) support and renewable energy certificates (REC), including waste energy REC 0.25 for other bioenergy and REC 1.0 for power transactions, an adequate profit model can be built through self-energetic power generation, thereby drawing keen attention from related industries. Therefore, if WDF is used appropriately as a high-quality engine fuel, it can lead to the development of various fields such as novel renewable energy sectors, waste management, and EPR-related industries. This study is intended to produce WDF using plastic waste by using it as engine-generator fuel. Moreover, we investigate ways to improve the quality and suitability of WDF as an engine fuel.

• Geomechanics and Engineering
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• 제20권6호
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• pp.497-503
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• 2020

In the Kingdom of Saudi Arabia, the shallower depth of the earth's crust is composed of loose dune or beach sand with soluble salts. The expansive behavior of salt bearing soil, fluctuation of ground water table and extreme environmental conditions offer a variety of geotechnical problems affecting safety and serviceability of the infrastructure built on it. Despite spending money, time and other resources on repair and rehabilitation, no significant attention is paid to explore the root causes of excessive differential settlement and cracking to these facilities. The scientific solution required to ensure safety and serviceability of the constructed infrastructure is to improve the strength and durability properties of the supporting ground. In this study, shredded plastic is employed as a low cost and locally available additive to improve strength characteristics of the desert sand. The study shows a remarkable increase in the shear strength and normal settlement of the soil. A seven (07) degree increase in angle of internal friction is achieved by adding 0.4 percent of the shredded plastic additive. The effect of different proportions and sizes of the plastic strips is also investigated to obtain optimum values. Such a long-lived solution will seek to reduce maintenance and repair costs of the infrastructure facilities laid on problematic soil along with reduction of environmental pollutants.

• Archives of Plastic Surgery
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• 제41권4호
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• pp.418-420
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• 2014

Congenital melanocytic nevus consists of congregations of nevomelanocytes. It is found in approximately 1% of new born infants. Congenital melanocytic nevus needs to be excised before it transforms into a malignant lesion. Many strategies have been attempted for the removal and reconstruction of the nevus. Serial excision enables wound closure to be accomplished with a shorter scar than if the original lesion was elliptically excised in a single stage and reorientation of the scar closer to the relaxed skin lines. The routine utilization of an elliptical serial excision as a standard method of closure often leads to the formation of elongated scars and waste of skin. The "Cogwheel pattern" serial excision is a new technique for reducing the size of the nevus efficiently. Reducing the final scar length, distributing the tension over many directions, and having the chance of decrease in operation numbers are ultimately achieved with the use of the "Cogwheel pattern" serial excision.

• 자원리싸이클링
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• 제26권1호
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• pp.69-77
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• 2017

폐소형가전의 재활용 공정에서 발생하는 플라스틱류 중 검정색 플라스틱의 경우 재질 선별이 어려워 혼합물의 형태로 저급 재활용 되고 있다. 본 연구에서는 검정색 플라스틱의 재질별 선별을 위하여 비중선별, 정전선별, 근적외선 선별 및 IR/Raman 분광법 등 기존 선별 기술의 검토를 통하여, 현장 적용에 대한 문제점 및 제한사항을 확인하였다. 검정색 플라스틱의 재질선별에 대한 기술적 한계를 극복하기 위하여 레이저유도붕괴분광법(Laser Induced Breakdown Spectroscopy, LIBS)을 이용하여 검정색 플라스틱의 각 재질별 LIBS 스펙트럼을 분석하였으며, 정규화 과정을 수행한 후 차원축소 알고리즘인 주성분 분석(Principal Component Analysis, PCA)을 수행하였다. 또한, 검정색 플라스틱의 각 재질별 LIBS 스펙트럼 분석 및 주성분 분석을 통하여 향후 재질별 인식 및 선별 기술의 현장적용을 위해서는 추가적으로 해결해야 할 문제점을 확인하였다. 검정색 플라스틱의 재질별 인식의 정확성 및 선별효율의 향상을 위하여 지능형 알고리즘 분야의 연구를 통하여 효율이 우수한 분류기를 설계하고 분류기의 성능 및 신뢰도 향상을 위한 연구가 추가적으로 진행되어야 할 것으로 사료된다.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2021년도 춘계학술대회
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• pp.365-368
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• 2021

본 연구에서는 적외선 센서를 이용한 페트병 분리수거 시스템을 구현하였다. 제안된 시스템은 인식부, 제어부, 알람부 및 구동부로 구성된다. 인식부는 페트병을 감지해 페트병과 센서와의 거리를 측정하고 값을 추출하고 추출된 값을 표준 범위와 비교하여 값이 표준 범위를 벗어날 경우에는 제어값을 제어부에 전송하고, 특정범위를 넘어간 경우 라벨 혹은 뚜껑의 유무결과를 제어부에 전송한다. 제어부에서는 센서부로부터 전송받은 결과값에 따라서 수거함의 입구를 개방하거나 알람부를 제어하는 기능을 수행한다. 제안된 시스템 구현을 위하여 인식부는 적외선 센서로 구현하였고, 제어부는 C언어 기반의 아두이노 스케치 프로그램으로 제작하였다. 또한, 인식부와 제어부는 아날로그 신호를 이용하여 통신할 수 있게 하였다. 제안된 시스템은 정해진 알고리즘에 따라 페트병의 라벨과 뚜껑의 유무를 정확히 판단한 후 라벨 혹은 뚜껑이 부착되었을 때 수거함의 입구를 막는다. 국민 1인당 배출되는 폐기물의 양이 높고 재활용이 되지 않아 쓰레기의 대다수를 소각시키고 있는 상황에서 본 연구에서 제안한 시스템을 통하여 페트병의 재활용률을 높이기를 기대한다.

• 한국자원리싸이클링학회:학술대회논문집
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• 한국자원리싸이클링학회 2001년도 정기총회 특별강연 및 춘계학술연구발표회(2)
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• pp.19-22
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• 2001

In recent years, the creation of waste recycling society has been required to cope with the traditional ways of waste treatments. In accordance with the package recycling law in force, calls for the developments of new waste treatment techniques suitable for 21st century are growing higher. A new ash melting furnace system named Eco Burner Ash Melting Furnace System has been developed. It is a burner type ash melting system in which the fluffs made of the plastics segregated from municipal solid wastes are directly fired at high temperature in the furnace. This system provides an economical ash melting system because plastic wastes or paper scraps that have heretofore been considered hard to recycle are used in compensation for fossil fuel. In this paper, we describe the ash melting test results obtained from a substantiative facility.