• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 추계학술대회
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• pp.1353-1358
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• 2004

An experimental study of pool boiling behavior on micro-porous enhanced square heater surfaces immersed in PF5060 is performed. The effects of heater orientation, Subcooling and substrate distance on the pool boiling heat transfer performance for the double heaters were investigated under increasing heat-flux conditions. The boiling performance of micro-porous coated surface was better than that of plain surface. The double heaters with upper substrate of 0.2cm substrate interval have lower boiling performances compared with the results for the double heaters with that of 0.5cm and 1.0cm substrate interval and without the substrate. In comparison to upper heater and below heater with orientation, the upper heater has lower superheat temperature than the below heater due to the bubble sweeping.

• 대한기계학회논문집B
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• 제30권7호
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• pp.646-655
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• 2006

The present research is an experimental study on characteristics of cooling behavior for the adjacent copper blocks with surface roughness or micro-porous coated surface. The experiments were carried out at saturation state or within subcooled states of PF5060. The effects of heater orientation and the intervals between heating surfaces or substrates were investigated under various heat flux conditions. The boiling performance of copper block with micro-porous coated surface was better than that of copper block with surface roughness. It is understood that the bubble sweeping enhances boiling performance for the heaters with inclinations of $\theta=45^{\circ}\;and\;\theta=90^{\circ}$, where as the bubble flattening decreases boiling performance for the heaters with inclinations of $\theta=135^{\circ}\;and\;\theta=180^{\circ}$. In comparison to upper heater and below heater with orientation, the upper heater has lower superheat temperature than the below heater due to the bubble sweeping. It is also found that boiling performance decreases in the case of adjacent double heaters with only 0.2cm substrate interval.

• Nuclear Engineering and Technology
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• 제48권4호
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• pp.1022-1035
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• 2016

A double-tube once-through steam generator (DOTSG) consisting of an outer straight tube and an inner helical tube is studied in this work. First, the structure of the DOTSG is optimized by considering two different objective functions. The tube length and the total pressure drop are considered as the first and second objective functions, respectively. Because the DOTSG is divided into the subcooled, boiling, and superheated sections according to the different secondary fluid states, the pitches in the three sections are defined as the optimization variables. A multi-objective optimization model is established and solved by particle swarm optimization. The optimization pitch is small in the subcooled region and superheated region, and large in the boiling region. Considering the availability of the optimum structure at power levels below 100% full power, we propose a new operating scheme that can fix the boundaries between the three heat-transfer sections. The operation scheme is proposed on the basis of data for full power, and the operation parameters are calculated at low power level. The primary inlet and outlet temperatures, as well as flow rate and secondary outlet temperature are changed according to the operation procedure.

• 한국조리학회지
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• 제18권5호
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• pp.233-242
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• 2012

제호탕은 오매, 사인, 백단향, 초과 등의 한약재와 꿀을 넣어 만든 여름철 전통음료이다. 본 연구에서는 제호탕의 재료인 오매, 사인, 초과, 백단향의 항산화 활성, Total phenolic content, ${\alpha}$-glucosidase, ${\alpha}$-amylase inhibitory activity를 생리활성을 측정하였다. 또한, 전통적인 조리법(연밀)과 현대적인 조리법(중탕법, 모두 끓이는 방법)으로 제호탕을 만들었을 때 pH, 색도, 당도의 차이를 비교분석하였다. Total phenolic content는 사인이 120.45 mg GAE/g, 오매분말 연밀미비법이 152.66 mg GAE/g를 나타냈으며, DPPH free radical 소거활성은 사인이 93.13% 그리고 오매분말 연밀미비법이 56.44%를 나타내었다. ${\rho}$-nitrophenyl-${\alpha}$-Dglucopyranoside를 기질로 사용한 ${\alpha}$-glucosidase 저해효과는 $100{\mu}g/mL$ 농도에서 사인이 89.51% 저해율을 보였으며, 끓이는 방법이 ${\alpha}$-glucosidase 저해효과 52.38%, ${\alpha}$-amylase 저해활성 72.52%로 높은 저해능을 보였다. 이와 같은 결과, 제호탕 소재로는 사인이 항산화, 항당뇨 효과에 뛰어남을 확인할 수 있었다. 조리방법에 서는 오매분말 연밀미비법이 높은 항산화 활성을 나타내었으며, 항당뇨 효과는 끓이는 방법이 뛰어남을 확인할 수 있었다.

• 한국식품과학회지
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• 제48권4호
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• pp.335-340
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• 2016

본 연구에서는 다양한 식품으로부터 식중독 세균의 DNA를 추출하는 효율을 비교 하였다. 사용된 DNA 추출 방법은 TaKaRa Kit를 이용하는 방법, PrepMan reagent를 이용하는 방법, boiling method, PEG를 이용한 alkaline method가 사용되었다. 비용절감이나 시간절약 면에서 boiling method나 PrepMan method도 고려할 수 있지만, column kit를 이용하는 TaKaRa kit가 효율적이라고 판단되었다. 또한 정성 시험법에서 적은 양의 균을 검출하기 위해 증균배양을 거치게 되는데 이때 사용되는 증균배지의 성분이 DNA 추출 후에도 잔류하여 saline과 비교하였을 때 DNA 추출효율이 낮은 결과를 나타내었다. 따라서 증균배지의 성분을 제거한 뒤 DNA를 추출하는 것이 PCR의 효율을 높일 수 있을 것으로 예상된다. 정량 시험법에서는 증균과정을 거치지 않아 균을 검출할 때 DNA의 추출 효율이 중요하기 때문에 DNA 추출 효율을 높이기 위한 가장 좋은 버퍼를 선정하고자 하였다. 그 결과 E. coli O157:H7에서는 saline이, S. aureus에서는 증류수를 버퍼로 사용했을 때 DNA 추출 효율이 가장 높은 것으로 나타났다.

• Nuclear Engineering and Technology
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• 제48권4호
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• pp.932-940
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• 2016

Pool boiling heat transfer of water saturated at atmospheric pressure was investigated experimentally on Cu surfaces with high-temperature, thermally-conductive, microporous coatings (HTCMC). The coatings were created by sintering Cu powders on Cu surfaces in a nitrogen gas environment. A parametric study of the effects of particle size and coating thickness was conducted using three average particle sizes (APSs) of $10{\mu}m$, $25{\mu}m$, and $67{\mu}m$ and various coating thicknesses. It was found that nucleate boiling heat transfer (NBHT) and critical heat flux (CHF) were enhanced significantly for sintered microporous coatings. This is believed to have resulted from the random porous structures that appear to include reentrant type cavities. The maximum NBHT coefficient was measured to be approximately $400kW/m^2k$ with APS $67{\mu}m$ and $296{\mu}m$ coating thicknesses. This value is approximately eight times higher than that of a plain Cu surface. The maximum CHF observed was $2.1MW/m^2$ at APS $67{\mu}m$ and $428{\mu}m$ coating thicknesses, which is approximately double the CHF of a plain Cu surface. The enhancement of NBHT and CHF appeared to increase as the particle size increased in the tested range. However, two larger particle sizes ($25{\mu}m$ and $67{\mu}m$) showed a similar level of enhancement.

• Nuclear Engineering and Technology
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• 제39권4호
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• pp.313-326
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• 2007

In this paper, an algorithm to reconstruct two orthogonal images into a three-dimensional image is developed in order to measure the bubble size and volume in a two-phase boiling flow. The central-active contour model originally proposed by P. $Szczypi\'{n}ski$ and P. Strumillo is modified to reduce the dependence on the initial reference point and to increase the contour stability. The modified model is then applied to the algorithm to extract the object boundary. This improved central contour model could be applied to obscure objects using a variable threshold value. The extracted boundaries from each image are merged into a three-dimensional image through the developed algorithm. It is shown that the object reconstructed using the developed algorithm is very similar or identical to the real object. Various values such as volume and surface area are calculated for the reconstructed images and the developed algorithm is qualitatively verified using real images from rubber clay experiments and quantitatively verified by simulation using imaginary images. Finally, the developed algorithm is applied to measure the size and volume of vapor bubbles condensing in a subcooled boiling flow.

• 한국식생활문화학회지
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• 제24권4호
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• pp.366-375
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• 2009

This study examined the changes of side dishes in "Eumsikdimibang", "Gyuhapchongseo", "Chosunmusangsinsikyorijebub" over time. As food ingredients, seaweed, red pepper, salted fish, Korean hot pepper paste have been used in "Gyuhapchongseo". The use of cattle by parts, saltwater fish, Chinese cabbage, powdered red pepper, garlic have increased in"Chosunmusangsinsikyorijebub". Cooking techniques, such as the use of wheat flour, a double boiler by the use of steam, and boiling and then roasting cuisine were mostly used in"Eumsikdimibang", but reduced in"Gyuhapchongseo". In "Gyuhapchongseo", the cooking methods are primarily aimed at a positive visual effect, and slices of dried meat seasoned with spices have increased. In"Chosunmusangsinsikyorijebub", various Tang (Guk), the taste of food changed by controlling the gravy content (Gigimi, Chigye, Chorim), meat mixing oil, vegetable and mushroom together to cook and boiling down the main food ingredients to soak the seasoning were increased. Dog-meat steamed dish using the intestine of dog in "Eumsikdimibang" was changed to small intestine of cattle steamed dish in "Gyuhapchongseo". And seasoned dog meat with choncho in "Eumsikdimibang" influenced on beef tail soup with Korean hot pepper paste in "Gyuhapchongseo", and Yookgyejang soup using Korean hot pepper paste in"Chosunmusangsinsikyorijebub". In steamed young chicken, the stuffing such as soybean paste, choncho, welsh onion, leek and flour in "Eumsikdimibang" was changed to minced beef, welsh onion, dropwort and Shiitake mushroom in"Gyuhapchongseo". The steamed young chicken in "Chosunmusangsinsikyorijebub" with stuffing was added to chicken soup using glutinous rice, and ginseng powder. Now, the chicken soup was changed to Samgyetang with glutinous rice, and ginseng. In "Chosunmusangsinsikyorijebub", various vegetable dishes were cooked with beef.

• 한국조리학회지
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• 제21권1호
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• pp.1-14
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• 2015

본 연구에서는 돼지고기 삼겹살과 목살의 가열처리방법에 따른 새로 개발된 PCM 처리와 이중팬을 제작하여 사용하였으며, 기존의 가열조리방법과 비교하여 이화학적 특성과 관능특성을 비교하였다. 돼지고기 삼겹살과 목살의 수분함량은 찌기처리구에서 60.2%, 67.2%로 높게 나타났으며, 조지방은 삼겹살은 숯불처리구에서 33.2%, 목살은 전기그릴처리구에서 16.0%로 가장 높았다(p<0.05). 조단백질의 경우, 삼겹살은 스팀처리구가 18.4%로 높았고, 삶기처리구는 15.4%로 유의적으로 낮았다. 또한, 목살은 전기그릴처리구에서 25.2%로 유의적으로 높게 나타났다(p<0.05). 보수력과 가장 관계가 깊은 가열감량은 삼겹살과 목살 모두에서 숯불구이처리구 40.18%, 36.98%로 유의적으로 높았고, 전단력에서 삼겹살은 오븐처리구에서 $2.76kg/cm^2$으로 목살은 이중 팬처리구에서 $3.67kg/cm^2$으로 가장 낮았다(p<0.05). 육색 시험결과 L값은 삶기처리구에서 65.16, 59.72로 가장 높았고(p<0.05) b 값의 경우, 삼겹살은 삶기처리구에서 2.32로 가장 낮았다(p<0.05). 관능평가 결과 전체적인 기호도 항목에서 삼겹살의 경우, 전기그릴처리구에서 7.56점으로 높았다. 목살은 팬구이처리구에서 7.22점으로 가장 높았으며, 반면, 삶기처리구에서 5.88점으로 가장 낮았다(p<0.05).

• Journal of the Korean Wood Science and Technology
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• 제36권4호
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• pp.37-43
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• 2008

본 연구의 목적은 천연자원이며 보속적인 생산이 가능한 식물성기름(콩기름)을 오존 산화 처리에 의한 구조적인 변성을 시도하여 이를 바탕으로 친환경 목재 접착제를 개발하는 것이다. 식용 콩기름을 사용하여 시간당 약 7.13 g의 오존을 발생시켜 15분, 30분, 60분, 120분간 오존산화 처리한 후 화학적 변화를 알아보기 위하여 FT-IR을 측정하였으며 오존 산화 처리된 콩기름/pMDI를 중량비로 1:1로 혼합하여 접착제를 제조하여 상태, 준내수 및 내수 인장전단 접착력을 평가하였다. FT-IR 측정 결과, 콩기름은 $3010cm^{-1}$ 부근에 불포화 이중결합에 기인하는 흡수를 나타내었으며 오존산화가 진행될수록 $3010cm^{-1}$ 부근의 흡수가 사라지고 $1700cm^{-1}$ 부근의 카르복실기 또는 알데히드의 흡수가 크게 나타났다. 인장전단 접착력의 경우 상태, 준내수 접착력 시험 결과 모든 오존 산화 처리 시간에서 KS 합판 접착성 기준인 $7.0kgf/cm^2$를 안정적으로 상회하였으며 오존산화 처리 반응시간이 증가함에 따라 접착력도 증가하여 60분 처리에서 최대의 접착력을 보이다 120분 처리에서는 감소하는 경향을 나타내었다. 내수 접착력의 경우 30분, 60분, 120분 처리에서는 접착 기준을 만족 시키는 것을 확인할 수 있었다.