본 연구는 강우 시 발생하는 비점오염물질 중 인과 총 부유성 고형물 분석을 통해 혼합 토지이용에 따른 비점오염 배출 특성을 비교분석하였다. 경기도 용인시 금학천 유역내의 도시지역, 농업우세지역, 혼합토지이용지역, 택지개발지역을 대표하는 총 4개의 소유역 말단에서 강우유출수를 모니터링 하였다. 연구 결과 불투수층이 많은 도시지역은 강우초기에 초기유출현상이 뚜렷하게 발생되었고 다른 지역에 비해 용존성 인의 비가 약 40%정도 높았다. 농업우세지역과 혼합토지이용지역, 택지개발지역은 대부분 인이 고형물에 부착되어 배출되는 입자성 인의 형태를 보였으며, 도시지역과 달리 첨두유량이 발생하는 강우 중기에 가장 높은 농도의 오염물질(TP 및 TSS)이 배출되었다. 모든 모니터링 지점에서 TSS와 TP 농도간 높은 상관성을 나타내고 있어 TP의 배출 제어를 위해서는 TSS의 적절한 제어가 매우 중요함을 알 수 있었다. 특히 택지개발지의 경우 타 토지이용지역에 비해 다량의 토사침식에 의하여 높은 TP 배출부하가 야기될 수도 있음을 예상할 수 있었다.

In this study, microcrystalline cellulose, which is a cell wall polysaccharide commonly contained in sea algae (brown algae, red algae and green algae), is used in substitution for cellulose and is hydrolyzed with seven enzymes available in the market. The seven enzymes selected are Viscozyme® L, Celluclast® 1.5 L, Saczyme, Novozym® 33095, Fungamyl® 800 L, Driselase® Basidiomycetes sp., and Alginate Lyase. To maximize the production of the reducing sugar by hydrolysis with each enzyme, we optimized the quantity of enzymes, reaction time, pH, and reaction temperature as four independent variables, and the reducing sugar production rate as a dependent variable, utilizing response surface methodology (RSM) to optimize the enzyme hydrolysis reaction conditions. Among the tested enzymes, the production rate of reducing sugar by Celluclast® 1.5 L was the highest. Hence, the predicted optimum conditions (8.5 % enzyme, reaction time 27.6 h, pH 4.1 and reaction temperature 44.1oC) were directly applied to Laminaria japonica and proved the predicted optimum conditions with experiments. Under the optimum conditions, the sugar yield of 137.6 mg/g-Laminaria japonica (experimental value) was obtained.

현재 “어업”과 “납”과는 매우 밀접한 관계가 있으나, 어구에 사용되는 납의 환경 중 거동에 대한 체계적인 연구는 찾아볼 수 없는 실정이다. 2012년 9월 10일부로 시행된 ｢낚시관리 및 육성법｣에서는 낚시 도구라 지칭되는 모든 제품에 kg 당 납 성분이 90 mg이 초과하는 제품은 사용할 수 없도록 하고 있으나, 납은 비용적인 면에서나 가공의 수월성 면에서 어망에 많이 이용되고 있는 실정이다. 더욱이 어망의 폐기 실태, 어망 중 함유형태 및 함유량 등에 대한 자료는 찾아볼 수 없어 환경에서의 거동에 대한 검토는 전무하다. 이에 어구, 특히 폐어망에 함유된 납추의 환경 중 거동(fate)을 알아보기 위한 연구의 일환으로 수행하고 있는 본 연구에서는 우선, 어망에 함유된 납의 형태 (실납, 납추 등)를 알아보고, 함유 형태별, 환경 매체별 환경으로의 납 용출량을 알아보고자 하였다. 최근 발표된 일본의 “폐정치망 어망의 적정처리와 리사이클의 가능성으로의 과제 (2011년)”에서, 우선 납에 의한 오염이 확산되지 않도록 하기 위해서 어망과 로프에서 납추를 완전히 분리할 필요가 있으며, 그 분리 방법도 외부에 부착된 경우와 내부에 삽입된 경우와는 서로 다름을 보고하고 있다. 또한 분리된 어망과 로프는 화학적 리사이클이나 열회수 등으로 재활용하고, 분리한 납은 순도가 높아 판매가 가능하다고 생각되나, 실제로는 사용된 납추에는 조개류가 부착된 형태이므로 다른 적정처리가 필요함을 제기하고 있다. 폐어망 5kg을 분리･분별 장치에 넣고 납 분리를 실시한 결과, 로프 약 3kg, 납 약 1.5kg를 회수했으며, 나머지는 토사 등이었다고 보고하고 있다. 또, 4 종류의 폐어망의 납 함유량을 조사한 결과, 42.4 - 58.4% (무게비) 함유하고 있음을 확인하였으나, 납추 또는 실납 형태별 환경으로의 용출량에 대한 자료는 찾아볼 수 없었다.

This study investigated the optimal sequential hydrolysis conditions by comparing with reducing sugar yield ofsequential hydrolysis of Laminaria japonica processing residue. After acid-catalyzed hydrothermal hydrolysis, sequentialenzymatic hydrolysis was performed with single enzymes such as Celluclast® 1.5L, Saczyme, and Alginate Lyase, andtheir mixture. As a result, the yield of reducing sugar by sequential hydrolysis with the mixed enzymes was the highest,but there would be an economical problem with excessive enzyme loading. Therefore, considering the reducing sugaryield and economics, it is thought that hydrolysis by the mixed enzymes has no advantage, thus, using the Celluclast®1.5L in the sequential hydrolysis was practically more appropriate. The optimal sequential hydrolysis conditions ofLaminaria japonica processing residue were determined to be 8% v/w of enzyme injection, 42.6oC of reaction temperature,pH 4.1, and 26 hours of reaction time after acid-catalyzed hydrothermal hydrolysis (0.108 N-HCl, 144oC of reactiontemperature, and 22 minute of reaction time).

Recent earthquake events arising all over the world, cause serious damages to material/ human resources every year. South Korea, categorized to be relatively safe from earthquakes, recently became subject to frequent seismic events, which made it essential to prepare for damages caused by such events. Failure of hydraulic structures, such as dams, can cause serious damages to resources in the lower reaches of a river. In this study, Seismic stability evaluation was performed to determine the crest displacements of dam caused by the 40 earthquake waves recorded actually.

While construction of dams have provided a solution for the depletion of fresh water which has brought up a demand for the storage capacity of such structures, On the other hand, dam failures cause serious damages to human lives and properties. Most studies for the stability analysis of dams have been performed by 2-dimensional modelling, which cannot take into account for various up/downstream shapes and boundary conditions related to various geological conditions. Considering such circumstances, 3-dimensional FEM analysis has tremendous advantages compared to 2-dimensional analysis because 3-dimensional modelling can catch the stress-strain behavior of dam more accurately.

본 논문에서는 행동경제학에서 주로 사용되는 전망이론을 게임 인공지능 분야에 도입하여 인간의 인지적 특성을 사실적으로 표현하고자 하는 관점에서 NPC의 의사결정 모델을 제안한다. 이를 위하여 효용 이론의 한계로 지적되었던 기준점 설정의 문제, 민감도 체감성, 손실 회피의 특징을 분석하고, 이를 게임 상에서의 NPC 의사결정 모델에 반영한다. 본 논문에서는 제안 모델을 동적 지형분석에 적용하였으며, 실험을 통해 NPC의 다양한 개성 부과 및 창발적인 행위를 유도할 수 있음을 확인하였다.

This study focused on immobilization of Saccharomyces coreanus to support materials and ethanol fermentation bythe immobilized yeast. Three porous media as support material were surveyed; synthetic zeolite, aluminum silicate andgranular activated carbon. Amount of yeast (determined by organic matter content) immobilized into/on support materialswas lowest in fermentation using aluminum silicate as supports. Glucose as substrate of ethanol fermentation was easilysorbed more than ethanol into/on 3 types of support materials. Of these, absorbed amount of glucose and ethanol into/on activated carbon was highest. The ethanol was actively produced for 16 hours in fermentation processes by yeastimmobilized into/on aluminum silicate and activated carbon, produced after 16 hours by yeast immobilized into/on zeolite.The produced ethanol concentration after 24h was as follows; 24.2g/L by using aluminum silicate, 19.3g/L by activatedcarbon and 16.1g/L by zeolite.

Generally, levee design is performed through deterministic methods. However, deterministic methods, which are unable to take into account the heterogeneity of a physical system, is limited to overcome variable uncertainties taking place in the natural phenomena. Accordingly, structure design based on reliability analysis considering the uncertainty of variables are getting spotlight. Climate changes and global warming occurring all over the world, are ground to frequent natural disasters, such as earthquakes, which can lead to serious damages based on their magnitude. In this research, a seismic safety assessment method for levees is introduced, adopting the concept of reliability analysis methods.

Recent earthquake events arising all over the world, cause serious damages to material/ human resources every year. South Korea, categorized to be relatively safe from earthquakes, recently became subject to frequent seismic events, which made it essential to prepare for damages caused by such events. Failure of hydraulic structures, such as dams, can cause serious damages to resources in the lower reaches of a river. In this study, as a counterproposal for deterministic safety assessment for seismic events on dams, which cannot take into account the uncertainty of various parameters, a method is introduced which constructs a safety chart by creating an artificial seismic wave considering uncertainties of seismic sources, propagation paths and site effects.

In this study, AC/DC responses of CNT-filled cement composites are measured and compared. Based on the results, it is found that AC measurement method is more reliable to measure the electrical resistance of CNT-filled cement composites.

In this study, an equivalent circuit model of CNT-filled cement composites is proposed. Both the polarization effect of electrode/composite interface and the complex resistance effect due to dielectric property of CNT cement composite are considered in the proposed model. Effective of the proposed model will be experimentally validated.

To investigate optimal condition of acid-catalyzed hydrothermal hydrolysis of Laminaria japonica, the main constituentsof Laminaria japonica such as cellulose, alginic acid and mannitol were hydrolyzed using acid-catalyzed hydrothermalreaction. Then, we proposed the re-designed experimental method including the predicted optimal conditions of the mainconstituents and performed acid-catalyzed hydrothermal hydrolysis of Laminaria japonica. The coefficients ofdetermination (R2) of Y5 (yield of reducing sugar from Laminaria japonica) were 0.877. P values of Y5 were 0.002,indicating significance, within 1% (p<0.01). The optimum reaction condition for acid-catalyzed hydrothermal hydrolysisof Laminaria japonica determined by the response surface methodology is 143.65oC of reaction temperature, 22min ofreaction time, hydrochloric acid concentration 0.108N, resulting in a production rate of 115.62mg/g-Laminaria japonica.

국내 도축장에서 발생되는 도축혈액은 과거 해양배출을 통해 대부분 처리하였으나, 최근 해양 배출 금지로 인해 다양한 처리방안이 모색되어져야 하는 실정이다. 본 연구에서는 자원화 방법의 하나로서 아미노산 액비생산에 목적을 두고 도축혈액 성분 중 가장 많은 비율을 차지하는 단백질을 이용하고자 하였다. 도축혈액 내 단백질의 생물학적 효소 분해 효율 향상을 위하여, 혈액 전처리 방법으로서 초음파 기술을 적용하였으며 최적 전처리 조건은 0.5 W/mL의 조사 밀도에서 30분간 처리할 때로 도출되었다. 이 때 가용화율은 97.72%였고 GPC 분석을 통해 저분자 단백질로 전환된 것을 확인하였다. 엑소 및 엔도 타입의 단백질 분해효소를 혼합하여 초음파 처리된 혈액을 가수분해 한 결과 최적 조합은 Savinase 1%와 Flavourzyme 1%를 혼합한 경우에서 확인되었으며, 반응 4시간 경과 후의 단백질은 27.8 mg/mL 유리아미노산은 54.6 mg/mL 였다. 이는 전처리를 실시하지 않은 혈액의 유리아미노산 농도인 13.1 mg/mL보다 약 4.2배 증가된 수치로 초음파 처리가 단백질 분해 효율 향상에 큰 영향을 미치는 것으로 확인되었다.

기계적 혼화와 수리학적 혼화가 결합된 인라인 믹서는 응집･혼화 공정에 있어서 그 효과가 여러 차례 증명되었다. 그러나 인라인 믹서는 대부분이 해외 기술이기 때문에 이와 관련된 국내 산업에서 활용하기에는 어려움이 있다. 따라서 효과적인 인라인 믹서의 활용을 위하여 국내 인라인 믹서의 기술 개발이 필요하다. 본 연구에서는 국내 인라인 믹서의 기술 개발의 일환으로 임펠러의 형상에 따른 인라인 믹서의 혼화 특성을 평가하였다. 혼화 특성은 전산 유체 역학(computational fluid dynamic, CFD) 해석 결과를 이용하여, 임펠러 주위의 속도 벡터 분포에 의한 유동장의 형성 및 주입된 응집제의 농도 분포를 비교하였다. 임펠러의 형상은 여러 형상의 임펠러 중 일반적으로 혼화에 많이 쓰이는 플레이트 형상과 스크류 형상의 임펠러를 선정하여 적용하였다. CFD 해석은 실제 현장을 모사하기 위하여, 기초 실험을 통해 도출된 압력, 점도 등의 조건 하에서 진행하였다. 두 가지 형상의 임펠러에 따른 인라인 믹서의 혼화 특성을 비교한 결과, 플레이트 형상보다 스크류 형상의 임펠러를 적용한 결과가 더 나은 혼화 특성을 보이는 것으로 나타났다. 스크류 형상의 경우 플레이트 형상보다 형성되는 유동장의 범위가 넓었으며, 주입된 응집제의 농도 역시 고른 분포를 보이는 것으로 나타났다. 또한 플레이트 형상의 임펠러를 적용할 경우 혼화 과정에서 단락류가 발생할 가능성이 있는 것으로 나타났다.

Inline mixer, mixing device combined mechanical and hydraulic mixing, has been demonstrated many times to be effective in mixing process for coagulation. But most of inline mixer are difficult to utilize in relevant domestic industry since it is a foreign technology. So the development of domestic inline mixer is strongly needed. In this study, we compared mixing characteristics through computational fluid dynamics(CFD) analysis with different shape of impeller for the development of domestic inline mixer. The shape of the flow field by velocity vectors and the concentration distribution of injected coagulant were analyzed for comparison of the results. We chose two shapes of impeller(plate and screw), the CFD analysis for them was conducted to simulate actual field conditions. The screw-shaped impeller showed more well-mixing characteristics than the plate-shaped impeller from the results. On the other hand, short-circuiting flow could occur when the shape of impeller was plate.

In this study, phytocapping which was widely and deeply studied in USA and Australia was investigated among the methane oxidation technology for the surface emission reduction, and the consideration matter to apply the technology was also suggested. The selection of plants to be suitable in climate and soil condition is the key factor when phytocapping would be introduced. In the United States, a fast growing, perennial and deep-rooting tree species are used for landfill covers or contaminated soil areas, and even understory grasses are chosen based on regional characteristics. However this phytocapping would have regional limitation, especially precipitation is an important environmental factor.

This study aimed to investigate the optimal enzymatic hydrolysis conditions of alginic acid using Viscozyme® L, Celluclast® 1.5L, Saczyme®, Novozym®, Fungamyl® 800L, Driselase® Basidiomycetes sp., and Alginate Lyase, for production of reducing sugar. Response surface methodology (RSM) based on central composite rotatable design was used to study effects of the independent variables such as enzyme (1-9% v/w), reaction time (10-30 h), pH (3-7) and reaction temperature (30-70oC) on the production of reducing sugar from alginic acid. The coefficients of determination (R2) of Y1, Y2, Y3, Y4, Y5, Y6, and Y7 for the dependent variable regression equation were analyzed as 0.947 0.968, 0.840, 0.926, 0.923, 0.892 and 0.825. And the p-value of Y1, Y2, Y3, Y4, Y5, Y6, and Y7 within 1% (p < 0.01) was very significant. The optimal conditions were 1.0% of the quantity of the enzyme, 10.0 hours of the response time, pH 3 and 70.0oC of the reaction temperature, where the production rate was 483.1 mg/g-alginic acid, the highest of all the enzymes used.

Even though the need for application of damping devices is being raised even in Korea, the design process for damping system is usually performed without considering not only if the design base shear has been reduced in proper ratio, but also if the response reduction due to the application of the damping device has been actually occurred. In this research, response reduction effect was checked as a reduced base shear force, energy approach, and logarithmic decrement approach for the bearing wall apartment buildings with fluid damper.

Acid hydrolysis of cellulose using hydrothermal reaction was conducted to maximize reducing sugar concentration and the response surface methodology (RSM) was applied to study the effects of independent variables, such as reaction temperature (116 ~ 184oC), reaction time (12 ~ 28 min) and hydrochloric acid concentration (HCl, 0.0159 ~ 0.1841 N) on reducing sugar concentration and production yield from the cellulose. With the optimum conditions of the acid-catalyzed hydrothermal hydrolysis, the reducing sugar (RS) was obtained as 369.14 mg-RS/g-cellulose in 172.77oC of the reaction temperature, 28.41 min of the reaction time and 0.067 N of the hydrochloric acid concentration. The glucose (Glu) was obtained as 281.94 mg-Glu/g-cellulose in 154.70oC of the reaction temperature, 11.59 min of the reaction time and 0.184 N of the hydrochloric acid concentration.