• 한국자동차공학회논문집
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• 제20권3호
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• pp.88-97
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• 2012

To measure the traffic pollutants with high temporal and spatial resolution under real conditions, a mobile emission laboratory (MEL) was designed. The equipment of the mini-van provides gas phase measurements of CO, NOx, CO2 and THC (Total hydrocarbon), and number density & size distribution measurements of fine and ultra-fine particles by a fast mobility particle sizer (FMPS) and a condensation particle counter (CPC). The inlet sampling port above the bumper enables the chasing of different type of vehicles. This paper introduces the technical details of the MEL and presents data from the experiment in which a MEL chases a city bus fuelled by diesel, DME and Bio-diesel. The dilution ratio was calculated by the ratio of ambient NOx and tail-pipe NOx. Most particles from the bus fuelled by diesel were counted under 300 nm and the peak concentration of the particles was located between 30 and 60 nm. However, most particles in the exhaust of the bus fuelled by DME were nano-particles (diameter: less than 50 nm). The bus fuelled by Bio-diesel shows less particle emissions compare to diesel bus due to the presence of the oxygen in the fuel.

• 한국자동차공학회논문집
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• 제19권5호
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• pp.92-99
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• 2011

To measure the traffic pollutants with high temporal and spatial resolution under real conditions, a mobile emission laboratory (MEL) was designed. The equipment of the mini-van provides gas phase measurements of CO, NOx, $CO_2$, THC (Total hydrocarbon) and number density & size distribution measurements of fine and ultra-fine particles by a fast mobility particle sizer (FMPS) and a condensation particle counter (CPC). The inlet sampling port above the bumper enables the chasing of different type of vehicles. This paper introduces the technical details of the MEL and presents data from the car chasing experiment of diesel bus equipped with aftertreatment system. The dilution ratio was calculated by the ratio of ambient NOx and tail-pipe NOx. Most particles from the diesel bus were counted under 300 nm and the peak concentration of the particles was located between 30 and 60 nm. The total PM number emission from diesel bus equipped with DPF was 10 orders of magnitude lower compared to those emitted from base diesel bus. And the total PM number emission from diesel bus equipped with SCR was comparable to the particle emission from base diesel bus.

• Preventive Nutrition and Food Science
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• 제21권3호
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• pp.197-201
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• 2016

Helicobacter pylori infection is associated with an increased risk of developing upper gastrointestinal tract diseases. However, treatment failure is a major cause of concern mainly due to possible recurrence of infection, the side effects, and resistance to antibiotics. The aim of this study was to investigate the activities of Centella asiatica leaf extract (CAE) against H. pylori both in vitro and in vivo. The minimum inhibitory concentrations (MICs) against 55 clinically isolated strains of H. pylori were tested using an agar dilution method. The MICs of CAE ranged from 0.125 mg/mL to 8 mg/mL, effectiveness in inhibiting H. pylori growth was 2 mg/mL. The anti-H. pylori effects of CAE in vivo were also examined in H. pylori-infected C57BL/6 mice. CAE was orally administrated once daily for 3 weeks at doses of 50 mg/kg and 250 mg/kg. CAE at the 50 mg/kg dose significantly reduced H. pylori colonization in mice gastric mucosa. Our study provides novel insights into the therapeutic effects of CAE against H. pylori infection, and it suggests that CAE may be useful as an alternative therapy.

• 한국분무공학회지
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• 제28권1호
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• pp.43-48
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• 2023

The waste-heat-recovery boiler with water spray (HR-B/WS) applies the heat exchange between the inlet air and exhaust gas with the water spray into the inlet air. The evaporation of water in the inlet air promotes heat recovery from the exhaust gas so that thermal efficiency can be improved by the enhanced condensing effect. The NOx emission can also be reduced by lowering the flame temperature due to the dilution effect of the water. In this study, the validity of this concept is examined by the practical boiler test performed with a 24 kW condensing boiler under the full load condition according to the water injection amount. The theoretical amount of water injection is calculated under the assumption of full evaporation of the sprayed water, which is calculated as 50 g/min. Since the injected water cannot evaporate fully in the actual system, the maximum water spray amount is set as 100 g/min. The results showed that the water injection can increase the thermal efficiency up to 95.59% and reduce NOx and CO emissions simultaneously to 8.9 ppm and 35 ppm at 0% of O₂. Although the heat energy loss increased due to the unevaporated water, the increase in water injection amount caused higher thermal efficiency due to the increased amount of the evaporated water.

• 농약과학회지
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• 제19권2호
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• pp.119-124
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• 2015

공주와 논산 육묘장에서 Pseudomonas syringae pv. syringae에 의한 세균점무늬병이 애호박에 심각한 피해를 주고 있지만, 점무늬병을 방제하기 위한 방제법이 개발되어 있지 않다. 종자처리와 방제약제를 선발하기 위하여 살균제 6종을 선택하여 병원균의 생장억제효과, 유묘에서 병 방제효과, 종자처리에 의한 병원균 및 병 방제효과를 각각 조사하였다. King's B배지에서 병원균 생장억제효과는 oxytetracycline 170 ppm, oxytetracycline 15 ppm + Streptomycin sulfate 188 ppm, oxolinic acid 200 ppm, streptomycin 200 ppm 처리 순으로 효과가 높게 확인되었다. Oxytetracycline 1.5% + streptomycin sulfate 18.8% WP와 oxytetracycline 17% WP의 유묘처리 시 방제가는 각각 71.4%, 49.4%이었다. Oxytetracycline 1.5% + streptomycin sulfate 18.8% WP를 인위적으로 감염된 종자에 처리하였을 때, 병원균의 생장을 완전히 억제하였으며, 유묘 발아실험에서 96% 방제효과를 나타내었다. Oxytetracycline 17% WP 2,000배 처리구에서 인위 감염 종자로부터 80 cfu/g의 병원균이 검출되었으며, 유묘발아실험에서 90%의 방제효과를 보였다. Streptomycin 20% WP의 2,000배액을 종자 처리하였을 때 병원균이 280 cfu/g으로 검출되었으며, 유묘발아실험에서 60% 방제효과를 나타내었다. 이러한 결과 oxytetracycline 1.5% + streptomycin sulfate 18.8% WP가 Pseudomonas syringae pv. syringae 에 의한 세균점무늬병의 방제와 종자처리를 위한 최적의 살균제로 판단된다.

• 대한수의학회지
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• 제33권4호
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• pp.623-632
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• 1993

This study was conducted to develop a sensitized latex-antigen for serodiagnosis of toxoplasmosis in animals. Tachyzoites of T gondii(RH-strain) harvested from mouse peritoneal cavity were purified through the filtraton of polycarbonate membrane(pore size, $3.0{{\mu}m}$, Costar Co.) and disrupted by ultrasonicator. The tachyzoite suspension was ultracentrifuged for 30 min at $60,000{\times}g(4{^{\circ}C})$ and the supernatant was used as a water-lysate antigen. Polystyrene latex particles of $0.8{{\mu}m}$ in diameter(Sigma) were used for the preparation of sensitized latex-antigen suspension. The several parameters including the preparation conditions, incubation buffer. serum dilution buffer and stability of agglutination reactions were evaluated and the results obtained were summarized as follows : 1. The antigen consisting of a water-lysate of T gondii tachyzoites was adsorbed onto polystyrene latex particles of $0.8{{\mu}m}$ in diameter by adding a latex suspension to an equal volume of diluted antigen solution and by incubating the mixture at $37{^{\circ}C}$ under different conditions. 2. The optimum incubation buffer used for the antigen sensitization was 0.1M Tris-HCl buffer(pH 8.0). 3. The optimum serum dilution buffer used for the latex agglutination test was 0.1M Tris-HCl-NaCl buffer(pH 7.4) containing 300 mM NaCl. But 0.1M Tris-HCl-NaCl buffer(pH 7.4) containing 300-600 mM NaCl, 0.5% BSA and 0.01% Tween-20 improved the agglutination pattems and cleared the background of microplate well without the effects on L.A titer. 4. The time required for antigen sensitization was 40 and 60 min in incubation buffer(pH 8.0) at $37{^{\circ}C}$. But the optimun time for antigen sensitization was min at $37{^{\circ}C}$. 5. The optimun quantity of antigen absorbed on latex particles for proper agglutination was the range of 20 to $32{\mu}g$ of latex particles. 6. The optimun concentration of the latex-antigen suspension for the proper agglutination reaction was determined as 0.2%(w/v). 7. The specificity, rapidity and simplicity of the latex-particle agglutination test suggested that it might be adaptable to large scale serum screening.

• 한국항해항만학회지
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• 제27권2호
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• pp.233-238
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• 2003

파랑에너지를 차단하고 항내 정온을 확보하기 위해 설치된 외곽시설인 방파제는 불투과성이기 때문에 항만을 폐쇄성으로 만들 수 있으며, 항내ㆍ외간의 해수교환은 급격히 감소될 수 있다. 항만개발의 최근 추세는 항내의 수질 보호와 친수성이 강조되어, 기존의 불투과성 방파제의 일부에 투과성으로 설계한 제체투과성 해수교환방파제를 설치하는 것으로 나타났다. 이 경우 외해의 에너지가 항내로 전달되어 항내 오염물질의 희석률 증대와 함께 외해로 배출되도록 하고 있다. 오염이 심화된 항만(남해 동부해안에 위치한 삼천포 구항)에서 항내 수질을 개선하기 위한 방안은 육상오염원을 제거하는 것이 최선이나, 폐쇄성이 큰 항만의 경우, 외해와의 해수순환을 강화시켜야만 한다. 즉, 기존의 항만에서의 항내 수질개선을 위해서 외곽시설의 일부에 해수소통구를 두는 방법이 가장 최선이라 할 수 있다. 본 연구에서는 항내 오염이 심각한 항만을 대상으로 하여, 해수소통구를 통한 해수순환 양상을 수치계산을 통해 검토하고 수반되는 해수교환율을 검토하였다. 본 연구에서는 유한 차분법으로 수치모델을 구성하였으며, 해수소통구 도입에 따른 항내의 해수순환 및 해수교환율을 평가하였다.

• Asian-Australasian Journal of Animal Sciences
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• 제30권8호
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• pp.1124-1134
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• 2017

Objective: This study explored the physico-chemical properties of late-incubation egg amniotic fluid and a potential in ovo feed (IOF) supplement. Methods: Amniotic fluid was collected from broiler breeders (Ross 308, 51 weeks and Cobb 500, 35 weeks) on day 17 after incubation. A mixture of high-quality soy protein supplement - Hamlet Protein AviStart (HPA) was serially diluted in MilliQ water to obtain solutions ranging from 150 to 9.375 mg/mL. The mixtures were heat-treated (0, 30, 60 minutes) in a waterbath ($80^{\circ}C$) and then centrifuged to obtain supernatants. The amniotic fluid and HPA supernatants were analysed for their physico-chemical properties. Results: Only viscosity and $K^+$ were significantly (p<0.05) different in both strains. Of all essential amino acids, leucine and lysine were in the highest concentration in both strains. The osmolality, viscosity and $pCO_2$ of the supernatants decreased (p<0.05) with decreasing HPA concentration. Heat treatment significantly (p<0.05) affected osmolality, pH, and $pCO_2$, of the supernatants. The interactions between HPA concentration and heat treatment were significant with regards to osmolality (p<0.01), pH (p<0.01), $pCO_2$ (p<0.05), glucose (p<0.05), lactate (p<0.01) and acid-base status (p<0.01) of HPA solutions. The $Ca^{2+}$, $K^+$, glucose, and lactate increased with increasing concentration of HPA solution. The protein content of HPA solutions decreased (p<0.05) with reduced HPA solution concentrations. The supernatant from 150 mg/mL HPA solution was richest in glutamic acid, aspartic acid, arginine and lysine. Amino acids concentrations were reduced (p<0.05) with each serial dilution but increased with longer heating. Conclusion: The values obtained in the primary solution (highest concentration) are close to the profiles of high-protein ingredients. This supplement, as a solution, hence, may be suitable for use as an IOF supplement and should be tested for this potential.

• 공업화학
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• 제28권5호
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• pp.581-586
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• 2017

본 연구에서는 하수 슬러지 및 음폐수의 효율적인 병합처리를 위해 고온호기 전처리의 적용가능성을 알아보고자 고온호기-중온혐기 연계공정의 소화효율과 메탄가스 생성량에 미치는 영향을 비교 검증하였다. 또한, 유기물 부하량 증가에 따른 공정 내 변화 양상을 관찰하기 위해 실험실 규모의 고온호기-중온혐기 소화장치를 제작하여 음폐수를 증류수로 희석하는 비율을 1/3 (Run I), 2/3 (Run II) 및 원액(Run III)으로 줄여가며 혐기소화 공정 내 변화 양상을 관찰하였다. 실험 결과 별도의 pH 조절 없이 고온호기-중온혐기 연계공정 소화조 내에서 pH가 7~8으로 안정하게 유지됨을 알 수 있었다. Volatile solid (VS)는 순응 기간 후 고온호기-중온혐기 연계공정에서 52.24% (Run I), 66.59% (Run II) 및 72.53% (Run III)의 제거효율을 보이며, 중온혐기 소화조(R3)에 비교하여 높은 VS 제거율을 보였다. 또한, 고온호기-중온혐기(R1-R2) 연계공정에서 약 1.6배 향상된 메탄 생성률이 관찰되었으며, 메탄수율의 경우에도 고온호기-중온혐기(R1-R2) 연계공정에서 현저하게 높은 값을 유지하였다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제14권5호
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• pp.10-17
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• 2009

생물학적 정화는 TPH로 오염된 지역을 정화하는 효과적인 방법으로 적용되고 있다. 하지만 미생물의 분해 활성이 적정온도 이하, 이상의 온도에서는 감소하기 때문에, 생분해 효율이 온도의 변화에 많은 영향을 받는 것으로 알려져 있다. 따라서 이번 연구의 목적은 유류 분해 효율이 우수한 중저온성 미생물을 분리하여 TPH로 오염된 지역에 적용할 때의 정화효율을 평가해 보는 것이다. 먼저 탄화수소 분해효율이 뛰어난 중온성($30^{\circ}C$)미생물 5종과 저온성($80^{\circ}C$) 미생물 3종의 consortia를 분리하였으며, 이들 미생물 consortia를 실험실내에서 유류로 오염된 토양에 적용해 본 결과, 중온성 미생물의 경우 초기 TPH 4,044 mg/kg이 10일 경과 후 1,084 mg/kg으로 73.2%, 저온성 미생물은 TPH 5,427 mg/kg이 50일 경과 후 1,756 mg/kg으로 67.6%의 처리효율을 보였다. 이 분해율은 휘발이나 희석에 의한 물리적 저감을 포함한다. 이후 분리된 미생물들을 토양 경작 현장에 적용해 본 결과, TPH 2,560 mg/kg의 오염이 56일 경과 후 87.1%의 제거율을 보였으며, 이때의 생분해 반응 속도상수는 $0.0374\;day^{-1}$이었다. 본 연구 결과는 저온, 중온 상태에서 미생물을 이용한 생물학적 정화가 더 다양하게 이용될 수 있는 가능성을 보여준 것으로 판단된다.