• 한국재료학회:학술대회논문집
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• 한국재료학회 2011년도 춘계학술발표대회
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• pp.244.2-244.2
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• 2011

We introduce a novel and robust method for the preparation of nanocomposite multilayers, which allows the excellent photoluminescent (PL) properties as well as the accurate control over the composition and dimensions of multilayers. By exchanging the oleic acid stabilizers of CdSe@ZnS quantum dots (QDs) synthesized in organic solvent with 2-bromo-2-methylpropionic acid (BMPA) in the same solvent, these nanoparticles were be alternately deposited by nucleophilic substitution reaction with highly branched poly(amidoamine) dendrimer (PAMA) through layer-by-layer (LbL) assembly process. Our approach does not need to be transformed into the water-dispersible nanoparticles with electrostatic or hydrogen-bonding groups, which can deteriorate their inherent properties, for the built-up of multilayers. The nanocomposite multilayers including QDs exhibited the strong PL properties achieving densely packed surface coverage as well as long-term PL stability under atmospheric conditions in comparison with those of conventional LbL multilayers based on electrostatic interaction. Furthermore, we demonstrate that the flexible multilayer films with optical properties can be easily prepared using nucleophilic substitution reaction between bromo and amino groups in organic media. This robust and tailored method opens a new route for the design of functional film devices based on nanocomposite multilayers.

• 대한화학회지
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• 제51권6호
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• pp.520-525
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• 2007

Thiourea/urea, 다양한 aromatic aldehydes, ammonium acetate의 세가지 요소를 가지고 마이크로파의 조 사하에서 무수조건의 활성화된 비산화재를 촉매로 사용하여 높은 수율의 6-aryl-1,2,4,5-tetrazinan-3-thiones/ones를 얻었 다. 6-aryl-1,2,4,5-tetrazinan-3-thiones/ones의 구조는 녹는점, MS, IR, 1H NMR, D2O 교환, 13C NMR, 이차원의 NMR 스펙트럼(HOMOCOR, HSQC)을 바탕으로 증명되었다.

• 대한설비공학회지:설비저널
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• 제11권4호
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• pp.19-33
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• 1982

우리나라에서 대량으로 제기되는 연탄재는 밀도가 낮으면서도 충분한 강도를 가지며 표면적을 많이 제공할 뿐만 아니라 흡착성이 있으므로 고정미생물막공법에서 매질로 사용하여 유기성 폐수를 처리하면 유기물 제거효율이 매우 높을 뿐만 아니라, 처리수의 BOD농도를 표면부하나 용적부하로 계산할 수 있으므로 처리시설의 설제가 용이한 경제적인 폐수처리공법이 될 수 있다. 그러나 연탄재 매질을 장기간 사용하면 원수내의 SS, 성장한 미생물의 탈리 등에 의하여 처리수의 수질이 악화될 수도 있으므로 종말침전지가 요구될 수도 있다.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2002년도 총회 및 춘계학술발표회
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• pp.114-117
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• 2002

Sorption and desorption studies were conducted to evaluate several media as a potential biobarrier for the remediation of groundwater contaminated with hydrophobic organic compounds (HOCs). Pahokee and Bion peats, Devonian Ohio shale, vermicompost, and 50% HDTMA-montmorillonite were used as model sorbents. Sorption and desorption isotherms were determined using the radiolabeled phenanthrene (Phe). Sorption capacity of Phe on several sorbents was in the order Ohio shale > 50% HDTMA-montmorillonite > vermicompost > Pahokee peat. Mineralization kinetics was investigated for Phe-sorbed sorbents using Pseudomonas putida 17484. Among the tested sorbents, active biodegradation of Phe was observed in shale and vermicompost: degradation in shale exhibited little lag time while that in shale showed a significant lag time. Results of this study indicate that sorbents used in this work can be utilized as permeable reactive biobarrier media for the remediation of HOC-contaminated groundwater.

• 한국수산과학회지
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• 제50권3호
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• pp.250-256
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• 2017

This study investigated the removal efficiency of organic matter and nitrogen from fish farm effluent by hydraulic retention time (HRT) using an upflow biological filter (ANR system) reactor. The recycling time and influent flow in the reactor were controlled to 14.8, 7.4, 5.5 and 3.2 h to evaluate HRT. In addition, each reactor was coupled to a fixed bed upflow filter charged with media. The results showed that removal efficiency was ${\geq}95%%$ with an HRT of 5.5 h, and nitrification efficiency was reduced to 81% with an HRT of 3.2 h, although nitrification efficiency temporarily decreased due to the shock load as HRT decreased. Total nitrogen removal rate was also reduced to about 65% with an HRT of 3.2 h, which was considered a washout effect of nitrifying and denitrifying microorganisms by increasing the shearing force to the filter media, which decreased organic matter and nitrogen removal efficiency.

• The Korean Journal of Ceramics
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• 제4권4호
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• pp.292-296
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• 1998

In wet powder processing of alumina, a number of organic molecules such as dispersant and binder are used to produce the flow behavior and properties requisite for shape forming. In this study, interparticle forces of alumina particles suspended in aqueous media were controlled by suspension pH, poly (methacrylic acid) (PMAA, used as dispersant) and poly (vinyl alcohol) (PVA, used as binder). The combined adsorption isotherms of the dispersant and binder additives on alumina were determined by total organic carbon analyzer, while the adsorption of dispersant was differentiated from binder in the mixed additive system by ultraviolet spectroscopy. The electrokinetic behavior of alumina suspensions were then correlated with the adsorption characteristics of dispersant and binder onto alumina particles. It was found that the isoelectric ($pH_{iep}$) of alumina shifted from pH 8.9${\pm}$0.1 to acidic pH as PMAA concentration increased, while PVA adsorption did not affect the $pH_{iep}$ but caused a decrease in the near surface potential.

• KSBB Journal
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• 제9권3호
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• pp.306-311
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• 1994

유기용매상에서 Bacillus licheniformis에서 생산되는 protease를 이용하여 라세믹 ${\alpha}$-methylbenzy lamine의 광학분함을 행하였다. 이 반응은 아설 제 공자로 활성 에스대르를 샤용하여 라서l믹 아민을 광 학선택적으로 아마드로 변환시킨다. 이 반응의 반응 속도와 광학선택성을 증가시켜주기 위해 효소를 완 충액에 녹여 pH를 맞춘 후에 동결건조시키거나, 동결건조시 염이나 lyoprotectants를 첨가시키는 방 법, 적당한 유기용매의 선정, 에스테르 구조의 디자 인 등의 방법을 사용하였다. 그 결과. 30배의 초기 반응속도의 증가 및 12배의 광학선택성이 증가하는 결과를 보였다.

• KSBB Journal
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• 제15권5호
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• pp.501-506
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• 2000

A bench-scale air biofilter was evaluated for the removal of volatile organic compounds (VOCs) from a gas stream. Compost and peat were used as the biological attachment media. Biofilter operating parameters such as incoming VOCs concentrations, temperature, and packing materials were examined. After 26 days of acclimation periods, at 25$^{\circ}C$ and 45$^{\circ}C$, the biofilter removed more than 90% of 30 to 72 mg/㎥ of total VOC. After 40 days of operation, the concentrations of isoprene, toluene, and m-xylene were reduced to 96∼99, 91∼93, and 91∼93% of the original concentrations. VOC removal efficiency was not affected by the temperature. The medium pH was maintained near neutral (pH 6.5∼7.1). After 37 days of operation, the total bacteria count in the biofilter media increased to 1.12${\times}$10(sup)8 cells/g of medium.

• 한국환경보건학회지
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• 제28권1호
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• pp.79-84
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• 2002

Entrapped media with cellulous triacetate in which activated sludge was applied to induce operating factors and sewage treatment on site. The results are summarized as follows; The treatment efficiency of entrapped media is 92%, 90% and 80% at the size of 5mm, 7mm, and 12mm, respectively. Also, treatment efficient rate was increased by the packed amount of media in less than 30 % packed, while in more than 40 % packed that was decreased. It takes 10 day to reach the steady states and it is less than the existing activated sludge method. The slopes of oxygen consumption rate are almost parallel both in the entrapped media and free sludge. When organic loading rate is less than 1.0 kg/m$^3$ㆍd on site, it is achieved good removal rate independent of changes of loading rate.

• 한국지반환경공학회 논문집
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• 제4권2호
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• pp.93-104
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• 2003

Porous media consist of physically and chemically different materials and have an extremely complicated behavior due to the different material properties of each of its constituents. In addition, the internal structure of porous materials has generally a complex geometry that makes the description of its mechanical behavior quite complex. Thus, classical continuum mechanics cannot explain the behavior of materials with pore spaces, such as concrete, soils and organic materials in waste landfill. For these reasons, porous media theory has been developed in the nineteenth century. Biot had the greatest influence on the development of porous media theory. Biot's work has been referred by many authors in the literature. Development of numerous fundamental equations in porous media theory were made possible due to Biot's work. His contributions made the greatest influence on porous media theory. Therefore, it is highly advantageous to review Biot's publications. This work presents a review of Biot's work. It shows how porous media theory has been developing so far and provides a chance to discuss the contribution of his work to the modern porous media theory.