• Journal of the Korean Applied Science and Technology
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• v.33 no.2
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• pp.352-360
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• 2016

The purpose of this study was to determine the electrochemical properties develop DSA electrode for sewage sludge solubilization. Using Ir as a main catalyst, the catalyst selected for the sewage sludge solubilization durability and proceeds to functional electrode suitable for sewage sludge electrolysis experiment were obtained the following results. Less mass reduction of the sintering temperature of the main catalyst, Ir coated electrodes, the endothermic reaction zone $300^{\circ}C$ to $500^{\circ}C$, which was selected from a range of experiments. The efficiency of the catalyst results came up to $350^{\circ}C$ best. Each Binder stars (Ta, Sn, W) in this experiment was the biggest catalyst efficiency at $350^{\circ}C$. Used as a binder, $TaCl_5$, $SnCl_4$, $WCl_6$ of the Ta and without affecting the other characteristics of the main catalyst than Sn, W. For the 50% $IrO_2$ electrode is 1.4 V (vs. Ag / AgCl) in a current of about $29mA/cm^2$ was caused to evaluate the effectiveness of the electrode.

• Applied Chemistry for Engineering
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• v.10 no.7
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• pp.1052-1060
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• 1999

Tire and raw material of tire, i.e., SBR were degraded using pyrolysis process. The yield of pyrolytic oil was increased and that of gas was decreased with increase of operating temperature in pyrolysis. And the yield of pyrolytic oil was increased and that of gas and char was decreased with increase of heating rate. The maximum oil yields of SBR and tire were 86% and 55% each at $700^{\circ}C$ with a heating rate of $20^{\circ}C/min$. The number average molecular weight ranges of SBR and tire were 740~2486, 740~1719, and the calorific value of SBR and tire was 39~40 kJ/g. The oil components were consisted of mostly 50 aromatic compounds. The particle size was decreased and the surface area was increased with increase of operating temperature, and the BET surface area was $47{\sim}63m^2/g$. The optimum condition of pyrolysis was the temperature of $700^{\circ}C$ with heating rate of $20^{\circ}C$, and the reactor was continuously purged with inert gas to sweep the evolved gases from the reaction zone.

• Journal of the Mineralogical Society of Korea
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• v.16 no.1
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• pp.49-63
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• 2003

Rare and unusual occurrence of hydrothermal minerals were found in Geode mine area. They are developed in the late stage of hydrothermal alteration of earlier skarns and later by the open-space filling crystallization. The alteration of earlier skarns of clinopyroxene, garnet, and plagioclase formed mainly chlorite or sometimes uncommon hydrothermal minerals of prehnite, illite, and pumpellyite. Open-space filling crystallization characterized by hydrothermal minerals developedin open sapce or good are prehnite, pumpellyite, clinozoisite, illite, and Ca-zeolites of stilbite annstellerite. Mineral phases and paragenesis are examined in detail by microscopy, XRD, SEM, and EPMA. Using the Schreinemaker's method, equibrium reactions among these minerals are establishedand isothemal-isobaric phase diagrams of $\mu$$H_2O$-$\mu$$CO_2$cot are plotted. Hydrothermal minerals such asprehnite, pumpellyite, clinozoisite, illite, and some chlorite were ffrmed under high partial pressure of $CO_2$with relatively low $H_2$O fugacity. Later, stilbite and calcite in association with illite crystallized under relatively both high partial Pressure of $CO_2$and high $H_2$O fugacity.

• Journal of Conservation Science
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• v.22
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• pp.121-134
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• 2008

The mechanism of stone exfoliation and its cause in relation to chemical weathering by soluble salt were studied. Chemical, mineralogical and physical analysis was performed in exfoliation samples from stone monuments. The representative salt is gypsum in the exfoliation samples. In order to understand the salt reaction, stone samples(tuff and granite) were treated with two type of the salt, gypsum and sodium sulfate, which have different solubility. The capillary water uptakes are slight increased in impregnated with Na2SO4 and weathering simulation of two rock types. It means that the rock is deteriorated in the near of the surface by $Na_2SO_4$. $CaSO_4{\cdot}2H_2O$ bring out the thicker exfoliation than $Na_2SO_4$ because it is penetrated into the deeper zone and amount of accumulated salt is more abundant in the inner part than in the near of the surface. The exfoliation was formed in the tuff by salt treatment and 30cycle of weathering simulation, but there are not significant symptoms of exfoliation in the granite by same condition. This result was caused by the different capillary water uptakes and porosity of the rocks. In the tuff, salt solutions are penetrated into the inner part due to its high capillary water uptakes and porosity but the granite, which has low value relatively, can be formed thinner exfoliation.

• Microbiology and Biotechnology Letters
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• v.36 no.4
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• pp.268-275
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• 2008

In order to develop the multi-functional rhizobacteria that can exert positive effect on the growth of plants growing in the coastal sand dune located along East Coast of Korea, rhizospheral bacteria of 11 different plants from this area were isolated 1,330 rhizobacteria. Among these, 23 strains were able to produce auxin and had spectrum of antagonism toward various phytopathogenic microbes. To know the mechanism of this antifungal activity, these 23 strains were subjected to further analyses; 19 strains of these produced siderophore as determined by color reaction on CAS-blue plate, 4 strains produced antifungal cellulase as judged by color change on CMC-Congo red plate, 17 strains were able to utilized insoluble phosphate salts, also determined by clear zone formation on PVK medium. Identification of the strain was assigned to all 23 strains by l6s rDNA sequence analysed, and all were identified to be in the genus of Bacillus and Pseudomonas. One strain of these, denoted Pseudomonas fluorescens IB4-14, showed ACC deaminase activity which is known to be involved in the resistance of environmental stress such as salt and drought. Also, P. fluorescens IB4-l4 showed the germination stimulation and roots growth promoting activity on the in vivo assay of Lysimachia mauritiana Lam. (spoonleaf yellow loosestrife).

• Proceedings of the Korea Inteligent Information System Society Conference
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• 2000.04a
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• pp.417-426
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• 2000

정보 시스템 개발은 크게 계획, 분석, 설계, 구축의 네 단계로 이루어진다. 이중 사용자 요구사항을 파악하는 분석 단계는 시스템개발 수명주기에 있어 가장 큰 비중을 갖는다. 또한 수명주기의 초기 단계에서 발견되지 못한 결점은 개발이 진행될수록 수정하는데 많은 비용과 노력을 필요로 하게 되어 분석 결과물의 품질은 전체 시스템 품질에 큰 영향을 미치게 된다. 분석 단계의 주요 작업은 데이터 모델링과 프로세스 모델링이다. 이중 데이터 모델리을 위한 지식베이스 시스템 개발에 대한 노력은 기존 연구에서 수행되어 왔으나 프로세스 모델링을 위한 지식베이스 시스템에 대한 연구는 부족하다. 특히 최근 User Interaction이 많은 시스템이 점점 증가하고 있는 추세에 적합한 프로세스 모델링 방법과 지식베이스에 대한 연구가 필요하다.이 연구에서는 사용자 상호작용이 많은 시스템 환경에서의 프로세스 모델링을 위한 절차를 제안하고, 제안된 절차를 효과적으로 지원하고 결과물의 품질을 보증하기 위한 지식베이스 시스템을 구축한다. 모델은 다음의 주요 작업들로 구성된다: 이벤트 분석, 프로세스 분석, 이벤트/프로세스 상호작용 분석. 이벤트 분석은 영향을 주는 이벤트와 그로 인해 수행되어야 하는 업무 절차(Response)를 파악한다. 프로세스 분석은 이벤트 분석과는 독립적으로 수행되며 상위 수준의 업무부터 최하위 수준의 프로세스까지 도출한다. 이벤트/프로세스 상호작용 분석은 이벤트와 프로세스의 분석 결과를 상호 검증하기 위하여 실시된다. 제안된 프로세스 모델링 방법을 지원하기 위한 지식베이스 시스템을 웹 환경에서 구현하였다. 구현된 지능형 robot과 spider 등으로 구성된, 신뢰성 있고 지능적인 MP3 검색 엔진 지원 시스템의 설계와 구현 결과 그리고 성능 등을 종합적으로 요약한다.실어증 환자들은 화시적 대명사를 조응적 대명사보다 더 잘 처리하는 동일한 결과를 보였다. 이러한 실험 결과들은 실어증 환자들이 뇌손상으로 인해 문법적 언어처리에는 어려움을 보이지만 비언어적인, 세상 지식과 관련된 화시적 대명사의 처리는 가능할 것이라는 가설을 뒷받침 해준다. 또한 이러한 실험 결과를 통해 대명사의 기능적인 측면에서 화시와 조응의 처리가 구분되어 있음을 보여준다.l mechanism is concentrate on only the reaction zone. As strain rate and CO2 quantity increase, NO production is remarkably augmented.our 10%를 대용한 것이 무첨가한 것보다 많이 단단해졌음을 알 수 있었다. 혼합중의 반죽의 조사형 전자현미경 관찰로 amarans flour로 대체한 gluten이 단단해졌음을 알수 있었다. 유화제 stearly 칼슘, 혹은 hemicellulase를 amarans 10% 대체한 밀가루에 첨가하면 확연히 비용적을 증대시킬 수 있다는 사실을 알 수 있었다. quinoa는 명아주과 Chenopodium에 속하고 페루, 볼리비아 등의 고산지에서 재배 되어지는 것을 시료로 사용하였다. quinoa 분말은 중량의 5-20%을 quinoa를 대체하고 더욱이 분말중량에 대하여 0-200ppm의 lipase를 lipid(밀가루의 2-3배)에 대

• Proceedings of the Korea Inteligent Information System Society Conference
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• 2000.04a
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• pp.307-316
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• 2000

MP3(MPEG 1 layer 3) 파일 형식(file format)은 최근 높은 압축율과 뛰어난 음질 복원 능력으로 주목을 받고 있다. 실제로 MP3의 압축율은 CD의 약 50분의 1 정도이고 음질은 CD 음질을 동일한 수준으로 유지할 수 있다.한편, 이러한 MP3의 장점 때문에 web을 통해 MP3 파일을 찾으려는 수요는 폭발적으로 증가하고 있지만 기존의 검색 엔진들이 가지고 있는 프로세스는 급속하게 update되고 있는 MP3 컨텐츠에 효과적으로 대응하지 못하고 있는 실정이다. 특히, 기존의 검색 엔진들은 미디어 파일을 위한 검색이 아닌 문자 기반의 검색 기능을 위해 개발되어 MP3 검색에는 부적절하거나, 파일 중심이 아닌 사이트 중심의 링크 변동에 대하여 수동적인 업데이트만을 수행하여 빠른 변화에 능동적으로 대응하기 어려운 경우가 많다.현재 미디어 파일을 위한 검색 엔진들은 여럿 서비스 중이지만, 텍스트 중심의 탐색 방법을 사용하고, 정기적인 DB update 방법에 관해서도 문자 기반의 검색 엔진과 동일한 방법을 사용하고 있다. 또한, 국내에서는 web 서비스를 위한 미디어 파일 탐색 알고리즘과 지능형 탐색 방법에 등에 관한 연구 역시 거의 전무한 상태이다.본 논문은 MP3 파일 전문 검색을 위한 지능형 프로세스를 설계와 구현 결과에 관한 것으로, 기존의 미디어 검색 엔진들이 가지는 문제점을 지적하고 보다 효율적이고 능동적인 미디어 파일 탐색을 위한 방법을 제시한다. 특히, MP3 파일에 대한 미디어 파일 검증 알고리즘과 verification method을 제안하고, 이러한 메커니즘에 따라 구현된 지능형 robot과 spider 등으로 구성된, 신뢰성 있고 지능적인 MP3 검색 엔진 지원 시스템의 설계와 구현 결과 그리고 성능 등을 종합적으로 요약한다.실어증 환자들은 화시적 대명사를 조응적 대명사보다 더 잘 처리하는 동일한 결과를 보였다. 이러한 실험 결과들은 실어증 환자들이 뇌손상으로 인해 문법적 언어처리에는 어려움을 보이지만 비언어적인, 세상 지식과 관련된 화시적 대명사의 처리는 가능할 것이라는 가설을 뒷받침 해준다. 또한 이러한 실험 결과를 통해 대명사의 기능적인 측면에서 화시와 조응의 처리가 구분되어 있음을 보여준다.l mechanism is concentrate on only the reaction zone. As strain rate and CO2 quantity increase, NO production is remarkably augmented.our 10%를 대용한 것이 무첨가한 것보다 많이 단단해졌음을 알 수 있었다. 혼합중의 반죽의 조사형 전자현미경 관찰로 amarans flour로 대체한 gluten이 단단해졌음을 알수 있었다. 유화제 stearly 칼슘, 혹은 hemicellulase를 amarans 10% 대체한 밀가루에 첨가하면 확연히 비용적을 증대시킬 수 있다는 사실을 알 수 있었다. quinoa는 명아주과 Chenopodium에 속하고 페루, 볼리비아 등의 고산지에서 재배 되어지는 것을 시료로 사용하였다. quinoa 분말은 중량의 5-20%을 quinoa를 대체하고 더욱이 분말중량에 대하여 0-200ppm의 lipase를 lipid(밀가루의 2-3배)에 대하여 품질개량제로서 이용했다. 그 결과 quinoa 대량 7.5%에서 비용적, gas cell이 가장 긍정적 결과를 산출했고 반죽의 조직구조가 강화되었다. 또 quinoa 대체에 의해 전분-지질 복합제의 흡열량이 증대된 것으로부터 전분-지질복합제의 형성 촉진이 시사되었다.이것으로 인하여 호화억제에 의한 노화 방지효과가 기대되었지만

• Journal of the Korean GEO-environmental Society
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• v.10 no.2
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• pp.21-28
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• 2009

A grouting method has been widely used in construction of large-scale structure to reduce permeability and reinforce the ground. If cement and grout material were not mixed well in the injection tip equipment, an opposite flow and interception state of the chemical grouting can occur. McG (Multi-mixing counterflow prevented Grouting, McG) method installed a special grouting device to allow better mixing of the grouting material(above fineness $6,000cm^2/g$) and prevent backward flow. The block of nozzle also diversify powder rate of cement. YSS (Youngil Special Silicate, YSS) that lowers $Na_2O$ and thereby increases durability was developed by gel-forming reaction material. The seepage state and unconfined compressive strength of the injection material using the special injection tip equipment was tested in this study. The results of this study showed that the uniaxial compressive strength, permeability, N-value, TCR and RQD were improved by this method. Engineering characteristics obtained by the special injection tip method will be compared with those by the other method through various field tests from now on.

• Applied Chemistry for Engineering
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• v.31 no.4
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• pp.443-451
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• 2020

In this study, the physico-chemical properties and pyrolysis kinetics of livestock mature solid fuel were investigated to know its feasibility as a fuel. Ultimate and proximate analysis results showed that livestock mature solid fuel has high contents of volatile matter (64.94%), carbon (44.35%), and hydrogen (5.54%). The low heating value of livestock mature solid fuel (3880 kcal/kg) was also higher than the standard requirement of solid fuel (3000 kcal/kg). Thermogravimetic analysis results indicated that livestock mature solid fuel has three decomposition temperature regions. The first temperature zone (130~330 ℃) was consisted with the vaporization of extracts and the decomposition of hemicellulose and cellulose. The second (330~480 ℃) and third (550~800 ℃) temperature regions were derived from the decomposition of lignin and additional decomposition of carbonaceous materials, respectively. The activation energy derived from model free kinetic analysis results including Friedman, Flynn-Wall-Ozawa (FWO), and Kissinger-Akahira-Sunose (KAS) methods for the pyrolysis of livestock mature solid fuel was in the range of 173.98 to 525.79 kJ/mol with a conversion rate of 0.1 to 0.9. In particular, the activation energy increased largely at the higher conversion than 0.6. The kinetic analysis using a curve-fitting method suggested that livestock mature solid fuel was decomposed via a multi-step reaction which can be divided into five decomposition steps.

• Journal of Korean Society of Water and Wastewater
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• v.28 no.1
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• pp.13-23
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• 2014

A lab-scale Anaerobic Baffled Reactor (ABR) was applied to treat a primary sludge taken from a municipal wastewater treatment plant. In this experiment, acidogenic reaction was promoted by operating the ABR with short hydraulic retention time (HRT) to produce sufficient volatile fatty acids (VFA) instead of production of methane. The performance of ABR on the VFA production and total solids reduction was observed with different operating conditions with 2, 4, 6, and 8 days of HRT. Corresponding organic loading rates were 6.7, 3.4, 2.2, and $1.6kgCOD_{cr}/m^3{\cdot}day$. As HRT increased the removal rate of TCOD was also increased (82.5, 84.2, 96.9, and 95.9 % in average for HRT of 2, 4, 6, and 8 days, respectively) because the settlement of solids was enhanced in the baffle by the decrease of upflow velocity. At HRT of 2 days the average concentration of VFA in the effluent was measured at $1,306{\pm}552$ mgCOD/L corresponding to 107 % increment as compared to the VFA concentration in the influent. However, as HRT increased VFA concentraiotn was decreased to $143{\pm}552$ mgCOD/L at HRT of 8 days. The reduction rates of total solids were 12.2, 26.5, 24.8, and 43.0 % for HRT of 2, 4, 6, and 8 days. As HRT increased the hydrolysis of organic particulate matters in the reactor was enhanced due to the increasing of solids retention time in the baffle zone with low upflow velocity in long HRT condition. Consequently, we found that a primary sludge became a good source of VFA production by the application of ABR process with HRT less than 4 days and the 12-26 % of total solids reduction was expected at these conditions.