• 한국연소학회:학술대회논문집
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• 한국연소학회 2012년도 제44회 KOSCO SYMPOSIUM 초록집
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• pp.269-271
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• 2012

To investigate emission characteristics of laminar premixed CH4/air flame, combustion experiments were conducted at three flow rates (5.3L/min, 10.6L/min, 15.5L/min) with changing the combustor pressure(-30Kpa-30Kpa). It was found that with increasing flow rate, NOx emission increased in high pressure condition, while decreased in low pressure condition; and the emission of CO decreased with increasing flow rate. For the influence of pressure, emission of NOx increased with increasing pressure regardless of flow rates, while CO emission decreased on the contrary.

• 한국연소학회지
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• 제11권2호
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• pp.28-36
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• 2006

A constant volume combustion chamber was used to investigate the combustion characteristics. of homogeneous charge of methane-air mixture under various initial pressure, equivalence ratio and ignition times. The constant volume combustion chamber(CVCC) mostly has been studied by the experiments of visualization until now. So it is needed the numerical analysis of fluid and combustion characteristics in chamber by the more detail simulation. In this paper, the numerical analysis is tried to approach basically the homogeneous charge combustion phenomena under the various conditions, and the combustion phenomena in chamber is numerically analyzed by the commercial FIRE code. As a results, the combustion phenomena which were mean temperature, OH radical and reaction rate in chamber were investigated and it showed that the smallest flame growth occurs for the lean state and the increase of initial charged pressure condition due to the reduced OH radical.

• 한국물환경학회지
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• 제18권3호
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• pp.313-319
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• 2002

Laboratory experiments using metal coagulants[alum, PAC(Poly Aluminum Chloride)] and polymer were conducted in this study to enhance dewatering and settling characteristics for swine wastewater. In this study, application of mixture of metal coagulants and polymer improved settling and dewatering characteristics for swine wastewater compared to using only metal coagulants. Also sludge volume was decreased when the mixture was applied. About 80-90% of settling velocity was increased and thickening ratio was increased as much as two times when adding 100mg/L of cationic polymers. Polymer was excellent for enhancing dewatering property among coagulants.

• Food Science and Biotechnology
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• 제16권6호
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• pp.954-957
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• 2007

Gelation mechanism of xanthan-carob mixture (X/C) was investigated based on thermorheological behavior. Three X/C ratios (1:3, 1:1, and 3:1) were studied. Small amplitude oscillatory shear tests were performed to measure linear viscoelastic behavior during gelation. Temperature sweep ($-1^{\circ}C/min$) experiments were conducted. Using a non-isothermal kinetic model, activation energy (Ea) during gelation was calculated. At 1% total concentration, the Ea for xanthan fraction (${\phi}_x$)=0.25, 0.5, and 0.75 were 178, 159, and 123 kJ/mol, respectively. However, a discontinuity was observed in the activation energy plots. Based on this, two gelation mechanisms were presumed-association of xanthan and carob molecules and aggregation of polymer strands. The association process is the primary mechanism to form 3-D networks in the initial stage of gelation and the aggregation of polymer strands played a major role in the later stage.

• 한국정보통신학회논문지
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• 제16권9호
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• pp.1870-1877
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• 2012

천이신호는 지속시간이 짧으면서 길이의 변화가 크고, 시변성 및 비정재성 특성을 갖는다. 이러한 천이신호의 식별에는 분석 프레임 단위로 참조신호에 대한 기준패턴을 만들어 입력신호와의 유사도를 비교하는 방법이 효과적일 수 있다. 본 연구에서는 참조신호의 기준패턴으로 프레임 기반의 특징벡터들에 대해 확률통계 모형인 정규혼합모델을 적용하는 방법을 제안하고, 다양한 수중 천이신호에 대한 식별 실험을 통해 제안한 방법의 타당성을 검증하였다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 추계 학술발표회 논문집
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• pp.641-644
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• 2006

Recently, fiber cementitious composite has been researched due to its good ductility. In this paper, Ductile Fiber Reinforcement Cementitious Coposite (DFRCC) is applied as reinforcement in concrete to prove its better performance. Compare to ordinary concrete, DFRCC has higher ductility which helps control the propagation of cracking without decreasing the elastic modulus and ultimate strength. In this research, experiments of different mixture ratios have been implemented to find a suitable mixture ratio value to produce high performance DFRCC material.

• 한국표면공학회지
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• 제29권5호
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• pp.330-337
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• 1996

A rf reactive sputter deposition technique was adopted to deposit ferroelectric lead zirconate titanate (PZT) thin films with high rate from a ZrTi alloy target combined with PbO pellets. Deposition characterisitics including the effects of PbO are ratio were discussed. A new deposition mode called the quasi-metallic mode was observed. Perovskite PZT films were prepared at a growth temperature as low as$ 450^{\circ}C$. However, because the target structure is unstable, weproposed a mixture target consisted of Zr, Ti and PbO. Fundamental experiments were investigated using the powder target. Perovskite PZT film could be obtained at $450^{\circ}C$ with better electrical properties also.

• 한국산업융합학회 논문집
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• 제9권2호
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• pp.147-154
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• 2006

The authors conducted field experiments of frost heave to evaluate a method for reducing frost susceptibility using granulated used-tire mixture for 3 winters. Qualitative analyses for the evaluation of restraint effect of frost susceptibility by utilizing granulated used-tire soil mixture were conducted with the segregation potential concept and frost heave ratio. By mixing soil with granulated tire, the frost susceptibility was decreased drastically. From the result of the analyses, it was confirmed that granulated tire is an excellent material in controlling the frost susceptibility.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.87.1-87
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• 2003

Powdery mildew on strawberry plants, caused by Spherotheca aphanis (Wallr.) U. Braun var. aphanis, is the most serious disease for strawberry production. There is a demand to develop the substitutes for chemicals which are more environment friendly materials. Control of powdery mildew was evaluated on Akihime, Sachinoka, Dochiodome, Noyho and Redpearl varieties grown in the greenhouse. Applications of 1％, 0.5％, and 0.25％ of sodium bicarbonate (NaHCO3Nyoho in greenhouse experiments. Non-phytotoxicity was revealed on the leaves and fruits of strawberry at these concentrations. This$.$result indicates that a mixture of sodium bicarbonate and tween 20 is a useful substitute for fungicides to control powdery mildew of strawberry.

• 한국초지조사료학회지
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• 제22권4호
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• pp.233-240
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• 2002

겨울피복작물로 재배되는 헤어리베치는 토양과 동반작물에 질소를 공급한다. 본 시험은 겨울철에 헤어리베치와 사료작물을 혼파할 때 수량 및 사료가치의 개선정도를 알아보기 위해 3년간 수행되었으며 그 결과를 요약하면 다음과 같다. 호밀-헤어리베치 혼파시 호밀의 초장은 다소 감소하였으며 혼파에 따른 호밀 출수기는 큰 차이가 없었다. 건물 함량은 헤어리베치의 비율이 늘어날수록 낮아졌으나 파종방법에 따른 유의 적인 차이는 없었다. 조단백질 함량도 베치가 21.7∼21.8%로 호밀의 15.3∼15.8%에 비해 높았으며 혼파시 헤어리베치 비율의 증가에 따라 조단백 함량이 더 높아졌다. ADF, NDF 함량은 혼파구에서 호밀단파구보다 낮게 나타났다. 건물소화율 및 TDN 함량은 반대의 경향을 보였다. 건물수량은 호밀단파구에서 가장 높았으나 호밀단파구와 호밀 2/3+베치 1/3 구와의 유의 적인 차이는 없었다(P<0.05). 조 단백질 수량에서도 호밀단파구와 호밀 2/3+베치 1/3구는 유의성이 없었다. 토양중의 총 질소 함량은 재배후 0.06∼0.08% 정도 향상되는 것으로 나타났다. 이상의 결과를 종합하여 볼 때 호밀 2/3+베치 1/3구는 호밀 단파구에 비해 생산성 및 품질이 우수하여 토양보존과 생산성측면에서 권장되는 재배방법으로 판단되었다.