• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2017년도 추계 학술논문 발표대회
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• pp.20-21
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• 2017

In this study, fundamental properties by pore structure and heat of microhydration test were determined. As a result of pore structure analysis, BS(AA) specimen showed showed the maximum peak value of significantly lower incremental intrusion than the maximum peak value of incremental intrusion at smaller pore size than that of BS. As a result of heat of microhydration test, the maximum heating value was in the order of OPC > BS > BS(AA), and initial drying shrinkage and compressive strength of BS(AA) were expected to be improved.

• 한국식품조리과학회지
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• 제9권1호
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• pp.43-51
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• 1993

Buckwheat protein isolate was tested for the effects of pH, addition of sodium chloride and heat treatment on solubility, emulsion capacities, emulsion stability, surface hydrophobicity, foam capacities and foam stability. The solubility of buckwheat protein isolate was affected by pH and showed the lowest value at pH 4.5, the isoelectric point of buckwheat protein isolate. The solubility significantly as the pH value reached closer to either ends of the pH, i.e., pH 1.0 and 11.0. The effects of NaCl concentration on solubility were as follows; at pH 2.0, the solubility significantly decreased when NaCl was added; at pH 4.5, it increased above 0.6 M; at pH 7.0 it increased; and at pH 9.0 it decreased. The solubility increased above $80^{\circ}C$, at all pH ranges. The emulsion capacity was the lowest at pH 4.5. It significantly increased as the pH approached higher acidic or alkalic regions. At pH 2.0, when NaCl was added, the emulsion capacity decreased, but it increased at pH 4.5 and showed the maximum value at pH 7.0 and 9.0 with 0.6 M and 0.8 M NaCl concentrations. Upon heating, the emulsion capacity decreased at acidic pH's but was maximised at pH 7.0 and 9.0 on $60^{\circ}C$ heat treatment. The emulsion stability was the lowest at pH 4.5 but increased with heat treatment. At acidic pH, the emulsion stability increased with the increase in NaCl concentration but decreased at pH 7.0 and 9.0. Generally, at other pH ranges, the emulsion stability was decreased with increased heating temperature. The surface hydrophobicity showed the highest value at pH 2.0 and the lowest value at pH 11.0. As NaCl concentrationed, the surface hydrophobicity decreased at acidic pH. The NaCl concentration had no significant effects on surface hydrophobicity at pH 7.0, 9.0 except for the highest value observed at 0.8 M and 0.4 M. At all pH ranges, the surface hydrophobicity was increased, when the temperature increased. The foam capacity decreased, with increased in pH value. At acidic pH, the foam capacity was decreased with the increased in NaCl concentration. The highest value was observed upon adding 0.2 M or 0.4 M NaCl at pH 7.0 and 9.0. Heat treatments of $60^{\circ}C$ and $40^{\circ}C$ showed the highest foam capacity values at pH 2.0 and 4.5, respectively. At pH 7.0 and 9.0, the foam capacity decreased with the increased in temperature. The foam stability was not significantly related to different pH values. The addition of 0.4 M NaCl at pH 2.0, 7.0 and 9.0 showed the highest stability and the addition of 1.0 M at pH 4.5 showed the lowest. The higher the heating temperature, the lower the foam stability at pH 2.0 and 9.0. However, the foam stability increased at pH 4.5 and 7.0 before reaching $80^{\circ}C$.

• Journal of Advanced Marine Engineering and Technology
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• 제18권4호
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• pp.53-61
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• 1994

An experimental study on heat pump cycle systematizing characteristics for non-azeotropic refrigerant mixtures of R-22+R-114 was reported. Data were obtained under steady state condition at the ranges of parameters, 550- 2, 170kcal/h, 670-2, 990kcal/h, 24-71kg/h, and 0-1, for as cooling capacity, heating capacity, mass 25, 50, 75, and 100 per cent of R-22 by weight fraction for R-22+R-114 mixtures. The results shown that the C.O.P of the 50wt% of R-22 mixture was considerably larger than for pure R-22 and other weight fraction of R-22 mixtures, but the compression power of the 25wt% of R-22 was lower than that of the pure R-22 and the other weight fraction of R-22 mixtures. The hightest value of cooling capacity was obtained at the conditions of evaporating temperature 5.deg.C and R-22 50wt% mixture. In general, with an increase in the R-22 weight fraction for fixed values of the other parameter, the cooling capacity increased at first, obtained a maximum, and then decreasd. This verified the importance of accurate weight fractions od refrigerant mixtures in the heat pump cycle.

• 대한환경공학회지
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• 제35권8호
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• pp.540-546
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• 2013

이 연구에서는 C소각장에 반입되는 도시고형폐기물의 저위발열량을 추정할 수 있는 다중회귀직선식을 도시고형폐기물의 습량기준 물리적 조성 성분들로부터 유도하였다. 다중회귀직선식은 LHV = 1,670 + 39.20 Pl + 11.19 Pa - 11.27 Fo이었다. 여기서 LHV: 저위 발열량(kcal/kg), Pl: 습량기준 폐플라스틱류(wt %), Pa: 습량기준 폐종이류(wt %), Fo: 습량기준 음식물류(wt %)이다. 유도된 식의 수정결정계수($\bar{R}^2$)는 0.7476이었고, 이 식에 의한 추정 저위발열량과 측정 저위발열량의 절대백분율오차 평균은 2.42%로 아주 작았다. 그러므로 이 연구에서 유도된 식의 정확성이 높다는 것을 의미한다. 그리고 유도된 식으로 다른 4개 소각장에 반입되는 도시고형폐기물들에 대하여 추정 저위발열량과 측정 저위발열량의 절대백분율오차 평균은 수용할 수 있는 범위(4.74~20.11%)이었다. 더욱이 이 방법은 습량기준 도시고형폐기물의 물리적 조성 성분별로 분류하여 각 조성 성분들의 습량기준 중량 비율만 분석하면 도시고형폐기물의 저위발열량을 추정할 수 있어 보다 경제적이고 또한 대단히 효율적이다.

• Journal of Animal Science and Technology
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• 제64권2호
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• pp.380-395
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• 2022

This study investigated the utilization of detoxified Rhus verniciflua (RV) extract as a natural antioxidant to extend the shelf life of chicken breast meat during storage. Pre-heating at (35℃, 100℃, 120℃, and 140℃) was conducted on heartwood of RV prior to extraction to improve its antioxidant activity and remove the allergenic compound urushiol. The antioxidant activity was the highest when RV pre-heated at 120℃ with the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and azinobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) scavenging activity observed at 62.29 EC₅₀ ㎍/mL and 12.11 IC₅₀ mg/mL, respectively. Pre-heating also significantly increased the total phenolic content (TPC), with the highest improvement was seen at 120℃, 100℃, and 140℃ respectively, wherein 35℃ shared no difference with the raw RV (RRV). Urushiol content was vanished following pre-heating at 120℃ and 140℃. With respect to these result, pre-heating treatment at 120℃ was applied before the extraction of the heartwood of RV. Prepared breast meat sample was dipped into distilled water as a negative control, 0.02% butylated hydroxytoluene (BHT) as positive control, and a solution containing detoxified RV extract (0.10%, 0.25%, 0.50%, 1.00%) at 4℃ for 60 min. Treatment group with 0.50% and 1.00% addition increased the redness and yellowness value on day 6 and day 3 of storage respectively (p < 0.05). The pH value of breast meat was also increased in treatment of 0.50% and 1.00% on day 0, but subsequently lower until end of storge day compared to control negative (p < 0.05). Furthermore, 0.50% treatment exhibited a higher antioxidant activity, stronger inhibition of the microbial growth evaluated by total viable count and maintaining a lower total volatile basic nitrogen among treatments (p < 0.05), unless for BHT and 1.00% treatment groups (p > 0.05). It indicates a similar efficacy of detoxified RV extract with that of positive control treated with BHT. The results of this study suggested that dipping chicken breast meat into a solution containing 0.50% of previously pre-heated RV heartwood at 120℃ could be a promising natural antioxidant for extending the shelf life, and at the same time improve its quality during storage.

• 한국대기환경학회지
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• 제14권6호
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• pp.577-588
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• 1998

Polycyclic aromatic hydrocarbons (PAHs) are products of incomplete combustion and, in urban area atmosphere, are mainly traffic or heating in origin. Size-segregated aerosol samples were collected on the Eixth story of Shinchon on the Yonsei campus, using a high-volume cascade impactor, between August 1994 and September 1995. Ten PAHs were analyzed by GC/MSD. The size distribution of PAH-containing particulates followed approximately a log-normal relationship with the majority of PAH content associated with particles below 3.0mm. PAHs concentration in submicron particles increased during the winter months. The Mass Median Diameter (MMD) value of annual particulates in the heavy traffic area of Shinchon shows about 1.6 pm. The MMD values of air particulate in winter were the lowest values and similar to that in summer, while MMD values of seasonal PAHs were generally lower than 1.0 pm. Among the PAHs, MMD values of PAHs with the more than 5 benzen ring were averagely lower than those with 4 benzin rings. Especially MMD's of dibenzo (a, h) anthracene in winter was clearly lower than in summer. This reason may be caused by fuels used for heating. In this area, 50∼80% PAHs mass was particles smaller than 1.0mm aerodynamic diameter in size range, and the MMD values of PAHs lower than those of other country's area.

• 한국산학기술학회논문지
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• 제9권6호
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• pp.1760-1767
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• 2008

본 연구는 울산지역의 산업단지에서 발생하는 유기성 슬러지에 대하여 삼성분, 원소조성, 빌열량 및 열중량 분석을 실시하였다. 삼성분 분석 결과 평균값은 수분함량이 72.9%, 가연분이 18.5%, 불연분이 8.6%로 나타났으며, 원소분석 결과 평균값은 C 33.9, O 26.4, H 4.4, N 4.4, S 0.6%로 나타났다. 저위발열량이 $1,500{\sim}2,000\;kcal/kg$ 사이인 업체가 6개 업체, 2,000 kcl/kg 이상의 발열량을 가지는 4개 업체는 직접 연소 처리하여 에너지화하는 것이 가능할 것으로 판단된다. 산업분류 코드 업종별 시료에 대한 TGA 분석 결과, 2개 업종에서 배출되는 유기성 슬러지의 경우 $800^{\circ}C$ 이상에서 연소를 해야 할 것으로 판단되며, 3개 업종에서 발생하는 슬러지의 경우 $600^{\circ}C$ 정도에서 저온연소가 가능할 것으로 판단된다.

• Journal of the Korean Wood Science and Technology
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• 제38권1호
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• pp.36-42
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• 2010

본 연구에서는 소나무재와 굴참나무재의 톱밥을 이용하여 제조한 목재펠릿과 두 수종의 톱밥에 목타르를 혼합하여 제조한 펠릿의 특성에 대해서 조사하였다. 펠릿은 상온에서 만능강도측정기를 이용하여 2000 kgf/$cm^2$의 압력을 가하여 제작하였다. 목재펠릿의 밀도는 굴참나무 톱밥으로 제조한 것이 소나무 톱밥으로 제조한 것보다 다소 높았고, 미세분 발생량은 굴참나무 톱밥으로 제조한 펠릿이 소나무 톱밥으로 제조한 펠릿보다 낮았다. 발열량은 소나무 톱밥으로 제조한 펠릿이 굴참나무 톱밥으로 제조한 펠릿보다 다소 높았다. 톱밥과 목타르를 혼합하여 제조한 펠릿은 목타르 함량이 증가함에 따라 함수율, 밀도 및 발열량이 높게 나타났고, 미세분 발생량은 적었다. 이상의 결과로부터 목타르는 고품질 펠릿제조를 위한 원료로서의 이용이 기대된다.

• 한국융합학회논문지
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• 제7권6호
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• pp.13-21
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• 2016

본 논문은 현재 진행 중인 대한민국 남부지역에 위치한 대학 내 스마트에너지캠퍼스 마이크로그리드에서 대학 내 빌딩에 설치될 수소전기분해 이용 연료전지 시스템 운용을 위한 선행 연구로써 고분자전해질막 전기분해(PEMWE)과 고분자전해질막 연료전지(PEMFC) 장치에서 동시에 온도변화 효과를 연구하고자 한다. 전반적으로 실험실에서 50W 고분자전해질막 연료전지(PEMFC)을 사용하여 수행하였다. 모니터링 프로세스는 무선 로라 노드와 게이트웨이 네트워크를 구성하여 실행하였다. 그리고 PEMWE와 PEMFC에 대한 수학적 모델링과 운전 알고리즘을 제안하였으며 제안한 모델에서 PEMWE는 낮은 발열 기준에서 효율이 더 높음을, 반면에 PEMFC는 높은 발열기준에서 효율이 더 높음을 을 알 수 있었다. 향후 대학 구내 빌딩에 설치될 실증시스템 성능을 높이기 위해 PEMWE와 PEMFC의 온도와 압력을 모니터링, 통신 및 제어 등 연구개발을 통하여 구현할 예정이다.

• 한국식품과학회지
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• 제38권5호
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• pp.720-723
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• 2006

본 연구에서는 우리 나라 세균성 이질을 유발하는 주요 원인 균인 S. sonnei를 대상으로 불충분한 열처리와 NaCl 처리에 따른 각각의 생존균수 변화와 불충분한 열처리 후 다양한 NaCl 농도 (0, 2, 4, 6%) 하에서 sublethal injured cell의 회복정도를 조사하였다. 그 결과, 불충분한 열처리 정도가 증가함에 따라 생존균수가 유의적인 감소를 나타내었으나, NaCl 처리시 NaCl 농도가 6% 까지 증가함에 따라서 생존균수의 변화가 거의 없었다. 그리고 $55^{\circ}C$에서 30분 동안 열처리후 2% TSAS 배지에서 7.58 log CFU/mL, 4% TSAS 배지에서 7.83 log CFU/mL, 그리고 6% TSAS 배지에서 7.93 log CFU/mL 만큼 각각 생성된 colony 숫자가 감소 한 것으로 조사되었고, $60^{\circ}C$에서 30분동안 열처리후 2% TSAS 배지에서 6.71 log CFU/mL, 4% TSAS 배지에서 6.73 log CFU/mL, 그리고 6% TSAS 배지에서 6.73 log CFU/mL 만큼 각각 생성된 colony 숫자가 감소한 것으로 조사되었다. 그리고 동일한 온도에서 sublethal heating후 노출된 NaCl 농도가 증가함에 따라서 D-value가 감소하는 경향을 나타내었다. 이와 같은 결과는 불충분한 열처리 과정에 의하여 생성된 sublethal injured cell들이 열처리후 회복되는 과정에서 배지의 NaCl 농도가 증가함에 따라서 회복정도가 감소하였음을 의미한다.