These days, the development of various pre- and post-combustion techniques has been pursued in order to reduce the emission of CO2 in the fleet of coal-fired power plants, since it is of great importance to each country’s energy production while also being the single largest emitter of CO2. As part of this kind of research efforts, in this study, a novel burning method is tried by the co-burning of the pulverized coal with the stoichiometric mixture of the hydrogen and oxygen (H2+1/2O2) called as HHO. For the investigation of this idea, the commercial computational code (STAR-CCM+) was used to perform a series of calculation for the IFRF (International Flame Research Foundation) coal-fired boiler (Michel and Payne, 1980). In order to verify the code performance, first of all, the experimental data of IFRF has been successfully compared with the calculation data. Further, the calculated data employed with pure coal are compared with the co-burning case for the evaluation of the substituted HHO performance. The reduced amount of coal feeding was fixed to be 30% and the added amount of HHO to produce a similar flame temperature with pure coal combustion was considered as 100% case of HHO addition. This value varies from 100 to 90, 80, 60, 50, 0% in order to see the effect of HHO amount on the performance of pulverized coal-fired combustion with the 30% reduced coal feeding. One of the most important thing found in this study is that the 100% addition of HHO amount shows approximately the same flame shape and temperature with the case of 100% coal combustion, even if the magnitude of the flow velocity differs significantly due to the reduced amount of air oxidizer. This suggests the high possibility of the replacement of the coal fuel with HHO in order to reduce the CO2 emission in pulverized coal-fired power plant. However, an extensive parametric study will be needed in near future, in terms of the reduction amount of coal and HHO addition in order to evaluate the possibility of the HHO replacement for coal in pulverized coal-fired combustion.

The objective of this research was to evaluate the toxicity of the industial xenobiotic Aroclor 1248 (A) and natural origin substances~elemental sulfur (S80) and oleic acid (OA) and their binary mixtures to V. fischeri bioluminescence during the prolonged exposure time (up to 60 min). The bioluminescence quenching test was used to determine the toxic effects. Full factorial experiment design and multiple regression analysis and the comparison of binary mixture effect with the sum of effects of individual chemicals were used for the evaluation of combined effects of toxicants. The analysis of general trend of mixture toxicity to bioluminescence showed that mixture toxic effects were reversible up to 60 min. Data analysis revealed different joint effects, which were depended on mixture composition. S80 enhanced toxic effect of A and acted additively with synergistic interaction. Hydrophobic OA in mixture with A acted antagonistically and in mixture with sulfur caused an additive effect with antagonistic component of interaction. It was concluded that low concentrations of natural toxic substances present in environmental samples as mixtures of chemicals can define the toxicodynamic character of industrial xenobiotics.

Performance Evaluation was conducted for analyzing fundamental properties of warm-mix asphalt mixture using 100% steel slag. This study tested and compared asphalt mixture used three types of asphalt binder and two types of aggregate.

기포가 포함된 다상흐름의 측정은 중요함에도 불구하고 많은 제약이 있었다. 특히, 공극률이 높은 다상 흐름은 밀도차의 급격한 변화와 두꺼운 공기-물 경계면으로 인해 측정이 매우 어렵다. 본 연구에서는 공극률에 상관없이 기포흐름을 측정할 수 있는 기포영상유속측정법과 다발 광섬유유동측정계를 소개하고자 한다. 기포영상측정기법의 경우, 화상측정시 발생하는 원근에 의한 오차를 최소화하고 추정할 수 있는 피사계 심도에 대한 계산방법을 제시하여 정도 분석을 위한 방안을 제시하였다. 다발 광섬유유동측정계는 얇은 광섬유의 특성을 이용해 다발로 제작하여 측정률을 증가시키고자 하였다. 제시된 두 기법을 기포플룸에 적용하여 신뢰도를 검토하였으며 잘 일치하는 것을 확인하였다. 소개된 기법으로 대표적인 하천 다상흐름인 도수흐름을 측정하여 그 적용성을 검토하였다.

According to the quality standards of the BIO-SRF(Bio-Solid Fuel Products) in Act on the Promotion of Saving and Recycling of Resources enforcement regulations, chloride is regulated to less than 0.5wt.%. The reason why chloride was regulated may generate HCl and dioxin when bio-solid fuel was burnt. Chloride and chloride compounds can be presented the characteristic of corrosiveness. These materials is reacted with iron to produce ferric chloride. Ferric chloride is oxidized to ferric oxide and ferric oxide can cause a pipe corrosion to short boiler life in combustion facility. There are several reactions to reduce Cl concentration in organic wastes and some wastes can be used in nucleophile reaction as reductive agents. Nucleophile(Nu) material can be represented by phosphate, nitrate, sulfate etc. Nu materials can substitute them for chlorine-based compounds(X-: Cl-, Br-, I-). Nu materials can reduce the harmfulness and chlorine concentration by substituting them for chlorine-based compounds of the solid fuel product produced by carbonization. In order to produce solid fuel product from organic wastes, carbonization among pyrolysis processes is suitable because nucleophile reaction should be an endothermic reaction, which heat must be entered to solid fuel product from outside. In this study, sewage sludge is used as a reductive agent to evaluate the characteristics of the reduction reaction in carbonization process because a large amount of Nu material is contained in sewage sludge. In order to evaluate the effect of Nu materials to control chloride in the residue of carbonization, waste wood mixed with sewage sludge was used in carbonization process.

This objectives of research are to figure out combustion characteristics with increasing temperature with petrochemical sludge by adding wasted organic matters which are waste electric wire, anthracite coal and sawdust, and to exam heating value and ignition temperature for using refused derived fuels(RDFs). After analyzing TGA/DTG, petrochemical sludge shows a rapid weight reduction by vaporing of inner moisture after 170℃. Gross weight reduction rate, ignition temperature and combustion rates represent 68.6%, 221.9℃ and 54.1%, respectively. In order to assess the validity of the RDFs, the petrochemical sludge by adding wasted organic matters which are waste electric wire, anthracite coal and waste sawdust. The materials are mixed with 7:3(petrochemical sludge : organic matters)(wt%), and it analyzes after below 10% of moisture content. The ignition temperatures and combustion rates of the waste electric wire, anthracite coal and waste sawdust are 410. 6℃, 596.1℃ and 284.1℃, and 85.6%, 30.7% and 88.8% respectively. In heating values, petrochemical sludge is 3,600 kcal/kg. And the heating values of mixed sludge (adding 30% of the waste electric wire, anthracite coal and waste sawdust) each increase up to 4,600 kcal/kg, 4,100 kcal/kg and 4,300 kcal/kg. It improves the ignition temperatures and combustion rates by mixing petrochemical sludge and organic matters. It is considered that the production of RDFs is sufficiently possible by using of petrochemical sludge by mixing wasted organic matters.

Lime-bordeaux mixture (LBM) has been used instead of pesticides in ginseng field and orchard since the 1960's in Korea. In this experiment, LBM was made with different concentrations and sprayed in the field of ginseng for eco-friendly cultivation. Growth characteristics and disease such as alternaria blight, anthracnose, and gray mold were investigated in 4-5 year old ginseng after spraying LBM. LBM caused a little damage on leaf when it was sprayed at the time of leafing stage, late April and early May. Root weights of five-year-old ginseng were 43.1~51.5 g and 41.2~46.6 g in the plot of mid-April and mid-May treatments, respectively. These growth levels were further reduced as compared with that of the chemicals treatment plot. The rate of diseases in the plot of 6-6 and 8-8 ratio were 0.0~4.8% and 0.0~4.4%, respectively, which was similar with that in the plot of chemical control for alternaria blight and anthracnose. However, LBM had little effect on controling gray mold. It showed lower control effect in the plot of 4-4 ratio than that of chemical control. This result will be expected to be a useful guide that can be used in the field to the farmers of the ginseng.

뽕잎, 녹차 및 뽕잎과 녹차혼합물이 sterptozotocin 유발 당뇨 쥐의 혈당 조절효과에 대해 살펴보았다. 실험군은 정상군(N), 당뇨 대조군(STZ), 5% 뽕잎 분말 첨가 당뇨군(STZ-M), 5% 녹차 분말 첨가 당뇨군(STZ-G) 및 2.5% 뽕잎과 2.5% 녹차혼합분말 첨가 당뇨군(STZ-MG)으로 5군으로 나누어 4주간 실시하였다. 체중증가량은 뽕잎, 녹차 및 뽕잎과 녹차혼합물 첨가 당뇨군(STZ-M, STG-G, STZ-MG)들이 당뇨 대조군(STZ)에 비하여 유의적 차이는 없었으나 다소 증가하였다. 뇨 중 포도당 함량은 뽕잎, 녹차 및 뽕잎과 녹차혼합물 첨가 당뇨군(STG-G, STZ-MG)들이 당뇨 대조군(STZ)에 비하여 감소효과를 보였다. 4주간 혈당의 변화는 뽕잎, 녹차 및 뽕잎과 녹차혼합물(STZ-M, STG-G, STZ-MG)의 급여로 혈당 수준이 감소하는 경향이었고, 뽕잎과 녹차혼합물 첨가 당뇨군(STZ-MG)이 혈당 강하효과가 가장 높았다. 시험 종료 후 혈청 포도당 함량은 뽕잎, 녹차 및 뽕잎과 녹차혼합물 첨가(STZ-M, STG-G, STZ-MG)로 당뇨 대조군(STZ)에 비하여 모두 유의적으로 낮게 나타나 정상군(N)과 비슷한 경향을 보였다. 혈청 인슐린 함량은 녹차 및 뽕잎과 녹차혼합물 첨가(STG-G, STZ-MG)로 당뇨 대조군(STZ)에 비하여 유의적으로 증가하였고, 혈청 fructosamine 함량은 유의적으로 감소하였다. 이상의 결과 뽕잎, 녹차 및 뽕잎과 녹차혼합물의 급여는 STZ로 유발된 당뇨 쥐의 혈당 강하효과를 확인하여, 당뇨성 질환의 예방 및 개선에 효과가 있을 것으로 사료된다.

he present study was conducted to provide basic data for efficient vermicomposting of swine manure by investigatingthe effect of rice hull mix on growth and reproduction of earthworms, amount of earthworm cast produced, and its chemicalcomposition when mixing swine manure in different levels (0 (SRH0), 10 (SRH10), 20 (SRH20), 30 (SRH30), and 40%(SRH40)) with rice hull commonly used as a bulking agent for facilitation in manure composting. The C/N ratio of thefeed was 10.19-13.95 and increased with higher level of rice hull mixed, and the survival rate of earthworms during theexperiment period was 35.2-99.2%. The biomass growth rate of earthworms was significantly higher in the SRH30 andSRH40 treatments than others (p<0.05), and young worms were not found in any treatments, but the number of cocoonswas 7.4 in the SRH40 treatment. The production of earthworm cast and digested amount were higher with the higherlevel of mixed rice hull (p<0.05), and the C/N ratio of cast increased with the mixed rice hull ratio, being significantlyhigher ratio in SRH40 than other treatments (p<0.05). Among heavy metals, the copper content tended to decrease withthe mixed rice hull level. To summarize, the higher level of mixed rice hull was associated with improvement in growth,reproduction, and cast production of earthworms, and 30-40% rice hull mix in particular could result in efficientvermicomposting.

The present study investigated an ethanol extract (SSB) of a mixture of three medicinal plants of Vitisamurensis, Aralia cordata, and Glycyrrhizae radix for possible neuroprotective effects on neurotoxicity induced byAmyloid β protein (Aβ) (25-35) in cultured rat cortical neurons and antidementia activity in mice. Exposure of cultured cor-tical neurons to 15μM Aβ (25-35) for 36h induced neuronal apoptotic death. At 1-30㎍/㎖, SSB inhibited neuronal death,elevation of intracellular calcium concentration ([Ca²+]i), and generation of reactive oxygen species (ROS) induced by Aβ(25-35) in cultured cortical neurons. Memory impairment and increase of acetylcholinesterase activity induced by intra-cerebroventricular injection of mice with 16nmol Aβ (25-35) was inhibited by chronic treatment with SSB (25, 50 and100㎎/㎏, p.o., for 8 days). From these results, it is suggested that antidementia effect of SSB is due to its neuroprotectiveeffect against Aβ (25-35)-induced neurotoxicity and that SSB may have a therapeutic role in preventing the progression ofAlzheimer’s disease.

각질형성세포주인 HaCaT세포에서 Lipopolysaccharide (LPS)로 유도하는 염증반응에는 tumor neurosisfactor-α (TNF-α), interleukin-1α (IL-1α), interleukin-6 (IL-6), 및 interleukin-8 (IL-8)와 같은 염증 유발 사이토카인(pro-inflammatory cytokines)이 증가되고, 또한 염증반응을 매개하는 induciblenitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2) 및 prostaglandins E2 (PGE2)도 증가된다. 본 연구에서는 이렇게 유도된 염증 반응에서 효과적으로 염증 관련인자를 조절할 수 있는 천연물을 발굴하고자 하였다. 그 결과, 마가목, 쐐기풀, 죽여 및 오배자 혼합 추출물이 IL-1α, TNF-α, IL-6 및 IL-8의발현을 억제하고 COX-2, iNOS 및 PGE2의 발현도 억제함을 확인하였다. 아울러 IQ chamberⓇ을 이용하여피부에 첩포할 때 sodium lauryl sulfate (SLS)로 유발한 피부자극에서 이들 혼합물이 효과적으로 그 자극을억제함을 확인하였다. 따라서 본 연구 결과로부터 마가목, 쐐기풀, 죽여 및 오배자의 혼합물이 피부자극완화용화장품 소재로서 민감성 피부 등을 위한 제품에 유용하게 사용될 수 있음을 확인하였다.

This study proposes a new parameter estimation approach for the mixture normal distribution. The developed model estimates parameters of the mixture normal distribution by maximizing the log likelihood function using a meta-heuristic algorithm-genetic algorithm (GA). To verify the performance of the developed model, simulation experiments and practical applications are implemented. From the results of experiments and practical applications, the developed model presents some advantages, such as (1) the proposed model more accurately estimates the parameters even with small sample sizes compared to the expectation maximization (EM) algorithm; (2) not diverging in all application; and (3) showing smaller root mean squared error and larger log likelihood than those of the EM algorithm. We conclude that the proposed model is a good alternative in estimating the parameters of the mixture normal distribution for kutotic and bimodal hydrometeorological data.

본 연구는 산업부산물을 아스팔트 혼합물 포장에 활용하고 천연골재를 대체하기 위한 연구로써 전기로 산화 슬래그를 이용한 아스팔트 혼합물의 물리적 성능과 내구성능을 분석하였으며, 현장 적용성을 분석하기 위하여 시험시공을 실시하였다. 아스팔트 혼합물의 내구성능을 평가하기 위해 아스팔트 혼합물의 최적 배합을 도출하여 평가하였다. 마샬안정도 등 실내시험결과 전기로 산화 슬래그 혼합물이 일반 혼합물보다 높은 강도를 나타내었다. 수분 민감도 실험에서도 일반 혼합물과 동등한 저항성을 나타냈다.시험시공을 통한 현장 적용성은 기존 천연골재 아스팔트 혼합물과 동일하였으며, 미끄럼저항성능이 더 우수한 것으로 확인되었다.

본 연구에서는 화산재를 건설재료로 활용하기 위하여 백두산, 한라산의 화산재 및 다공성의 제올라이트에 시멘트 및 메타카올린을 첨가한 공시체에 대한 재령 0일, 7일, 28일 배합비별 압축강도 특성 데이터를 바탕으로 인공신경망 모델에 적용하여 학습, 예측함으로써 강도예측을 위한 인공신경망의 적용 가능성을 평가하였다. 인공신경망 모델에는 역전파 학습알고리즘(back-propagation learning algorithm)이 적용되었으며, 다양한 입력변수를 달리한 최적의 인공신경망 조건에서 학습을 시행하였다. 또한, 다양한 배합조건이 일축압축강도에 미치는 영향에 대한 민감도 분석을 실시하였다. 이러한 연구를 통해 얻어진 결과물은 화산재를 활용한 블록의 일축압축강도 특성을 파악하는데 좋은 툴이 될 것으로 기대된다.

교통사고는 다양한 원인에 의해 발생한다. 도로 포장의 목적이 안전하고 쾌적한 이동이며, 차량의 주행속도가 높을수록 안전한 도로포장의 중요성이 커진다. 아스팔트 포장의 내구성을 향상하기 위한 기술 중 기존 화학 첨가제의 단순 혼합에 의한 개질 아스팔트의 한계를 극복하고자 반응형 아스팔트에 대한 관심이 높아지고 있으며 이중 대표적인 것인 에폭시 아스팔트 포장이다. 에폭시 아스팔트 혼합물은 아스팔트 바인더에 혼합된 에폭시 수지의 반응이 진행됨에 따라 경화가 진행된다. 따라서 이에 대한 정확한 예측을 통해 공사계획의 수립과 교통개방 가능시점의 결정이 가능하다. 에폭시 아스팔트 포장은 매우 뛰어난 내구성을 나타내기 때문에 이를 활용한 다양한 포장이 가능하며 특히 고가의 에폭시 아스팔트 포장의 적용을 확대하기 위해서는 에폭시 함량의 조절을 통해 필요한 성능의 확보와 경제성의 개선이 필요하다. 본 연구는 에폭시 수지 농도 변화에 따른 에폭시 아스팔트 혼합물의 경화속도 예측식을 제시하였다. 실외 양생 실험과 예측식과의 비교 결과 상관계수가 0.971 이상으로 나타나 예측식이 에폭시 함량 변화에도 에폭시 아스팔트 혼합물의 경화 정도를 예측 할 수 있는 것으로 나타났다.