• 방사성폐기물학회지
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• 제9권2호
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• pp.87-92
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• 2011

본 논문은 극저준위폐기물 관리에 관한 중국의 정책과 규정들을 소개하고 있다. 오래된 시설의 중요한 해체 및 부지복구 프로그램에 주어진 바와 같이, 극저준위폐기물의 처분을 위한 새로운 시설의 필요성이 대두되고 있다. 여러가지 일반적인 설계원리들은 다중방벽에 의해 폐기물을 격리시키는 중저준위폐기물 처분시설과 같다. 콘크리트 방벽을 사용하는 것 대신에 벤토나이트 또는 고밀도 폴리에틸렌 멤브레인을 사용하는 것 외에 통상적으로 처분시설의 설계는 위해폐기물 처분시설의 설계와 같다 극저준위폐기물 처분시설 2개소의 공학적 설계가 소개되었다.

• 한국토양비료학회지
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• 제21권3호
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• pp.241-245
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• 1988

야산지(野山地)를 경작지(耕作地)로 전환(轉換)하기 위한 기초자료(基礎資料)를 얻고자 영남지역(嶺南地域)을 중심(中心)으로 야산지(野山地) 토양(土壤)의 특성(特性)을 조사(調査)하였다. 일반적(一般的) 이화학성(理化學性)은 기경지(旣耕地) 토양(土壤)에 비해 불량(不良)하였다. 경사지(傾斜地)에서는 침식성인자(浸蝕性因子) K치(値)가 높고 입단안전성(粒團安定性)이 낮아 침식(浸蝕)에 의(依)한 표토(表土)의 유실(流失)이 있을 것으로 추정(推定)되었다. 주구성점토광물(主構成粘土鑛物)은 Kaoline계(系)이고 영일(迎日)II는 Bentonite로 판단(判斷)되었다. 이들지역(地域)의 토양(土壤)은 치환성(置換性) Al 및 Fe함량(含量)이 높고 인산흡착계수(燐酸吸着係數)가 246~551(Pmg/100g)으로 높았다. 따라서 야산지(野山地)를 경작지(耕作地)로 전환(轉換)하기 위해서는 물리(物理) 및 화학적(化學的) 성질(性質)의 개량(改良)이 선결(先決)되어야 하겠다.

• Bulletin of the Korean Chemical Society
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• 제1권1호
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• pp.10-17
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• 1980

Penicillin amidohydrolase was partially purified from the fermented broth of Bacillus megaterium, and was immobilized on nylon fiber. The surface area of nylon fiber was increased by roughening it with fine sand and activated by acid treatment. The free amino groups on the nylon fiber exposed by such treatment were then utilized to immobilize the penicillin amidase. Enzymatic properties of penicillin amidohydrolase immobilized on the nylon fiber by covalent bonding and cross linking with glutaraldehyde were studied and compared with those of soluble enzyme. The optimal pH and temperature profile of immobilized enzyme showed only slightly broader peaks, and the values of kinetic constants, $K_m$, $K_{ia}$, and $K_{ip}$, of the immobilized enzyme are only slightly greater than those of the soluble enzyme. These results suggest that the mass transfer effect on the reaction rate for the penicillin amidase immobilized on nylon fiber is not so significant as the enzyme immobilized on some other support material like bentonite. The experimental results of batch reaction agreed well with the results of computer simulation for both the immobilized and soluble enzyme systems, confirming the validity of the rate equation derived which was based on the combined double inhibition by two reaction products.

• 대한원격탐사학회지
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• 제7권2호
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• pp.131-147
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• 1991

Feature enhancement combined with some pattern recognition techiques were applied to the Remote Sensing Data for geological mapping with particular emphasis on non-me-tallic ore deposits and their related geologies. The area chosen is north of Ulsan, the size of which is about 400km$^2$. The geology of the area consists mainly of volcanics, volcanic sediments and clastic sediments of Miocene age, underlain by the Kyungsang sediments of Cretaceous age. The mineralization occurs in tuffs or along the bedding plane of tuffaceous sediments, the main products of which are Kaolinite and Bentonite. The outcrops or mine dumps in the study area were most effectively extracted on the histrogram normalized image of TM Band 1 and 2, due to their high reflectivity. These may be confused with some artificial features, like slate roof complex of the poultry farm or cement ground, which should be classified by field checking. Detailed examination of enhancment image combined with pattern recognition techniques made enable to classify different rocks and thereby extract volcanic products which are mainly related to non-metallic ore deposits in the study area.

• 대한원격탐사학회지
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• 제6권2호
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• pp.115-133
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• 1990

Study was made on the spectral characteristics of rock samples including bentonites collected from the northern Ulsan area. The geology of the area consists mainly of sediments of the Kyongsang Series and Bulguksa granite, the Tertiary volcanics, andesites and tuffs. Relative reflectances of meshed samples(2.5~10mm) to BaSO$_4$ are measured at 6 Landsat TM spectral windows (excluding the thermal band) with HHRR, and their reflection charactristics were analysed. In addition, three different data selection schemes including the Eulidean distance, multiple regression, and PCA weight methods were applied to the 30 TM ratio channels, derived from the above 6 bands. The selected data sets were subject to two unsupervised classification techniques(FA and ISODATA) in order to compare the effectiveness for classification of particularly bentonite from others. As a result, in ISODATA analysis the multiple regression model shows the best, followed by the Euliean distances one. The PCA weight model seems to show some confusion. In FA, though difficult for quantitative analysis, the best still seems to be the regression model. Among ratio bands, rations of band 7 or 5 against other bands represent the best contribution in classification of bentonites from others.

• 한국태양에너지학회 논문집
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• 제28권5호
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• pp.56-64
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• 2008

The objective of this study is to develope ground heat exchanger using PHC file used to building foundation, and it's element technology. So we construct PHC ground heat exchanger in the apartment house's PHC foundation and evaluate it's performance. First, we study PHC file type, heat exchanger pipe, grouting materials, and present apartment house's foundation condition for PHC ground heat exchanger and design it's proto type. Second according to grouting materials, we estimate construction convenience, and it's performance. Construction convenience side, PB 22 A pipe and sand grouting with moisture was good for PHC ground heat exchanger elements. Experiment result is very superior. Thermal conductivity B, C type(sand, gravel) was respectively 32.4 W/m$^{\circ}C$, 36.5 W/m$^{\circ}C$, D(concrete) Type 27.8 W/m$^{\circ}C$, E(bentonite) Type 19.6 W/m$^{\circ}C$. Thermal interference for 4 day experiment period in 3.8 m was very small. So PHC file is good for using ground heat exchanger.

• 한국토양비료학회지
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• 제44권3호
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• pp.415-424
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• 2011

This research was conducted to verified the effectiveness of a sintered porous media coated with organic matter as nutrient source and microorganisms as decomposer effective in TPH decomposition for a closed-typed biopole system. The organic matter content in the sintered porous media which was developed with bentonite increased with increasing dilution ratio of pig slurry and the sintered porous media as well as decrease in the particle size of sintered porous media. The decomposition rate of TPH was significantly increased with increasing aeration than that under atmospheric condition. Also the sintered porous media containing organic matter and microorganisms proved that the decomposition was enhanced with addition of nutrients sources in addition to aeration periodically.

• Membrane and Water Treatment
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• 제10권4호
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• pp.259-264
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• 2019

Cost effective clay adsorptive microfiltration membranes were synthesized to remove Cr (III) from high polluted water. Raw and calcined bentonite were mixed in order to decrease the shrinkage and also increase the porosity; then, 20 wt% of carbonate was added and the samples, named B (without carbonate) and B-Ca20 (with 20 wt% calcium carbonate) were uniaxially pressed and after sufficient drying, fired at $1100^{\circ}C$ for 3 hours. Then, physical and mechanical properties of the samples, their phase analyses and microstructure and also their ability for Cr(III) removal from high polluted water (including 1000 ppm Cr (III) ions) were studied. Results showed that the addition of calcium carbonate lead the porosity to increase to 33.5% while contrary to organic pore formers like starch, due to the formation of wollastonite, the mechanical strength not only didn't collapse but also improved to 36.77 MPa. Besides, sample B-Ca20, due to the presence of wollastonite and anorthite, could remove 99.97% of Cr (III) ions. Hence, a very economic and cost effective combination of membrane filtration and adsorption technology was achieved for water treatment which made microfiltration membranes act even better than nanofiltration ones without using any adsorptive nano particles.

• Geomechanics and Engineering
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• 제16권5호
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• pp.559-567
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• 2018

Technological innovations in sustainable materials for soil improvement have attracted considerable interest due to energy crisis and environmental concerns in recent years. This study presents results of a comprehensive investigation on utilization of nanocarbons in reinforcement of a residual soil mixed with 0, 10 and 20% bentonite. Effects of adding proportionate quantities (0, 0.05, 0.075, 0.1 and 0.2%) of carbon nanotubes and carbon nanofibers to soil samples of different plasticities were evaluated. The investigation revealed that the inclusion of nanocarbons into the soil samples significantly improved unconfined compressive strength, Young's modulus and indirect tensile strength. It was observed that carbon nanofibers showed better performance as compared to carbon nanotubes. The nanosized diameter and high aspect ratio of nanocarbons make it possible to distribute the reinforcing materials on a much smaller scale and bridge the inter-particles voids. As a result, a better 'soil-reinforcing material' interaction is achieved and desired properties of the soil are improved at nanolevel.

• 한국재료학회지
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• 제29권11호
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• pp.664-669
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• 2019

In this paper, a water-based green polymer mud is synthesized by simple compounding method. Effects of different kinds of tackifiers, their molecular weight on the viscosity of polymer mud and the effects of different fluid loss additives on mud fluid loss are studied. The results show that when polystyrene and anionic polyacrylamide with molecular weight of 8 ~ 10 million are used as the main thickening ingredient, polymer mud with high viscosity and high stability can be obtained. When the prepared polymer mud is formulated as NPAM: PEO: Hydroxypropyl cellulose(HPC) : Water = 42:10:10:100000 (unit: kg), the viscosity can reach 20.6 s, the filtration loss in 7.5 min is 24 mL, and the sand content is only 0.1 %. Compared with traditional bentonite mud, the green environment-friendly polymer mud has the advantages of small amount of waste, low environmental pollution, and low pulping cost, and can meet the construction needs for most topography and geomorphology drilling engineering.