• 한국자원식물학회지
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• 제31권4호
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• pp.283-293
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• 2018

본 연구는 생산과 수요가 늘고 있는 마디풀과 하수오의 최적 건조방법 구명을 통한 식품소재화 및 산업화를 목적으로 수행하였다. 하수오의 최적 건조방법을 구명하기 위해 열풍건조, 음건 및 동결건조 적하수오의 일반성분, 유리당, 아미노산 및 지방산 등을 비교분석하였다. 건물량을 기준으로 건조방법에 따른 적하수오의 일반성분 함량을 비교 하였을 때, 수분함량은 동결건조 적하수오가 유의적으로 낮게 나타났다. 유리당 분석에서 총 유리당 함량은 동결건조 적하수오에서 높게 나타났으며, fructose, glucose 및 sucrose의 함량 역시 동결건조 적하수오, 음건 적하수오, 열풍건조 적하수오 순으로 높게 나타났다. 유기산은 총 5종이 검출되었으며, oxalic acid가 가장 높게 나타났다. 적하수오의 주요 구성 아미노산은 arginine, glutamic acid, proline, serine, lysine 등이며, 총아미노산 함량, 필수아미노산 함량은 모두 동결건조 적하수오에서 높게 나타났다. 총 구성 아미노산 중 필수아미노산 함량 비율은 음건 적하수오에서 높게 나타났다. 유리 아미노산은 세가지 건조방법 모두에서 arginine과 proline이 함량이 높게 나타났으며, 총아미노산 함량, 필수아미노산 함량 및 총 구성 아미노산 중 필수아미노산 함량 비율은 모두 동결건조 적하수가 가장 높게 나타났다. 적하수오의 무기성분은 총4종이 검출되었으며, potassium이 가장 많았으며, sodium이 가장 낮게 나타났다. 적하수오에서 지방산은 포화지방산인 palmitic acid 1종과 불포화지방산인 oleic acid와 linoleic acid 2종이 검출되었다. 이상의 결과로 볼 때 하수오의 유용성분 손실이 가장 적은 건조방법은 동결건조로 생각되며, 산업적인 측면에서 비용을 고려한 건조방법은 건조온도를 조절한 열품건조 방법의 고안이 필요할 것으로 생각된다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회B
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• pp.2583-2588
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• 2008

In the present experimental study, the regime limit and pressure drop of dry-plug flow (dry wall condition at the gas portions of plug flow) in round mini-channels has been investigated. The air-water mixture was flowed through the round mini-channels made of Teflon, where the tube diameters ranged from 1.26 to 2.06 mm. For the present experimental range, with decreasing of the tube diameter, the transition between the plug and slug flows (wet and dry) happened at the higher gas superficial velocity region, which were in good agreement with the previous flow pattern maps tested. On the other hand, the transition between the wet- and dry-plug flows was little affected by the change of the tube diameter. In the pressure drop of dry-plug flows, among the correlations tested, the Lee and Lee's (2008) correlation best fitted the measured pressure drop data within the mean deviation of 10% for the present experimental range.

• Journal of Animal Science and Technology
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• 제58권5호
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• pp.20.1-20.11
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• 2016

The present review has mainly focused on the specific parameters including aging (aging days, temperature, relative humidity, and air flow), eating quality (flavor, tenderness and juiciness), microbiological quality and economic (shrinkage, retail yields and cost) involved beef dry aging process. Dry aging is the process where beef carcasses or primal cuts are hanged and aged for 28 to 55 d under controlling environment conditions in a refrigerated room with $0^{\circ}$ to $4^{\circ}C$ and with relative humidity of 75 to 80 %. However there are various opinions on dry aging procedures and purveyors of such products are passionate about their programs. Recently, there has been an increased interest in dry aging process by a wider array of purveyors and retailers in the many countries. Dry aging process is very costly because of high aging shrinkage (6 to 15 %), trims loss (3 to 24 %), risk of contamination and the requirement of highest grades meat with. The packaging in highly moisture-permeable bag may positively impact on safety, quality and shelf stability of dry aged beef. The key effect of dry aging is the concentration of the flavor that can only be described as "dry-aged beef". But the contribution of flavor compounds of proteolysis and lipolysis to the cooked dry aged beef flavor is not fully known. Also there are limited scientific studies of aging parameters on the quality and palatability of dry aged beef.

• 한국정밀공학회지
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• 제24권9호
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• pp.103-109
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• 2007

LCD (Liquid Crystal Display) is widely used electronic product. It needs too many processes such as PECVD (Plasma Enhanced Vapor Deposition), Sputtering, Photo-lithography, Dry etch. Each process is important but inspection process is more important because most companies emphasis on the six sigma. Recently, LCD inspection system is composed with inlet, inspector, outlet air pads. LCD is inspected on air pad which is shooting air from air hole. This paper studies on pad design of air bearing for LCD inspection to minimize LCD fluctuation. This design is able to reduce fluctuation and then satisfies CCD inspectional range. Also inspection pad needs to adequate stable area.

• 설비공학논문집
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• 제16권3호
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• pp.203-210
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• 2004

This paper describes the potential advantages in applying evaporative cooling to air-cooled condensers. The cooling characteristics of an air-cooled condenser with its surface fully covered with thin water film are investigated and compared with that of an air-cooled condenser with usual dry surface. By applying the evaporative cooling, the cooling performance of the condenser is shown to improve enormously. When the outdoor air is 35$^{\circ}C$ and 40% in relative humidity, the condensing temperature of the refrigerant is decreased by 2$0^{\circ}C$. Even when the incoming air is fully saturated with water vapor, the evaporation from the wet surface occurs to cause a decrease in the condensing temperature by 1$0^{\circ}C$. The main reason for this improvement is assessed as the addition of an efficient cooling mechanism which is the water evaporation resulting in latent heat absorption.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 춘계학술대회 논문집
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• pp.840-843
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• 2002

The dry pulverizing/Mixing device is used to deal with the spent fuels for the safe disposal. The separated pellets from hulls by a slitting device are put and oxidized from UO$_2$ solid pellet to U$_3$O$\_$8/ powder in the device. The device have been developed based on a voloxidation method which is one of several dry de-cladding methods. We have benchmarked dry de-cladding methods, analyzed applicability to the advanced spent fuel management process, integrated and compared several configuration, and finally derived detailed specifications proper to requirements for the device. Also, thermal characteristics of the device such as thermal stress and strain have been analyzed by the commercial software, 1-DEAS, and the reliability of the results have been verified by the KOLAS(Korea Laboratory Accreditation Scheme). The UO$_2$ solid pellets are put in the device which has a capacity of 20 kgHM per a batch, heated up about 600$^{\circ}C$ in the air environment. Then, the UO$_2$ solid pellets are oxidized into the U$_3$O$\_$8/ powder, and the powder is collected in a special vessel. The device has been designed and developed as fellows: the multi-staged fine hole meshes are used to reduce the size of the powder gradually, heat and air(oxygen) are supplied continuously to reduce the reaction time, and slight vibration effect are applied to collect powder cling to the device.

• 한국식품저장유통학회지
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• 제22권1호
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• pp.56-62
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• 2015

아로니아의 활용성 제고를 위하여 건조방법에 따른 품질특성을 비교한 결과, 건조과정 중 중량변화율은 진공동결건조가 81.6%로 가장 많은 중량감소를 나타내었고, 수분함량은 진공동결건조에서 가장 많은 수분이 감소하였으며, 건조 후 최종 수분함량은 진공동결건조에서 0.99%로 가장 낮은 함량을 나타내었다. 색도 측정결과, $L^*$값은 건조방법에 따른 큰 차이를 나타내지 않았으며, $a^*$값과 $b^*$값은 진공동결건조와 냉풍건조에서 증가하였고, 열풍건조에서는 감소하였다. 경도는 열풍건조에서는 건조 36시간 이후 급격하게 증가하였고, 냉풍건조는 서서히 증가하다가 132시간 이후 급격하게 증가하는 모습을 보였다. 건조방법에 따른 품질특성으로 건조수율은 냉풍건조가 24.20%로 가장 높았으며, 열풍건조 20.40%, 진공동결건조 19.41% 순으로 나타났다. 일반성분은 생과에서 수분이 61.76%로 가장 높게 나타났으며, 조회분은 열풍건조에서 가장 높게 나타났고, 가용성무질소물, 조단백, 조지방은 진공동결건조에서 가장 높은 함량을 나타내었다. 건조방법에 따른 아로니아의 pH는 3.84~3.92로 큰 차이가 없었으며, 당도는 동결건조($6.57^{\circ}Brix$) > 열풍건조($5.37^{\circ}Brix$) > 냉풍건조($4.40^{\circ}Brix$) > 생과($1.07^{\circ}Brix$) 순으로 나타났다. 무기질 함량은 진공동결건조에서 가장 높았으며, 주요 무기질은 K, Ca, Mg, Na인 것으로 나타났다. 아로니아에 함유된 당은 fructose, glucose 두 종류인 것으로 나타났으며, 진공동결건조가 20.59 g/100 g으로 가장 높은 함량을 가진 것으로 나타났다.

• Journal of Microbiology and Biotechnology
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• 제28권1호
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• pp.105-108
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• 2018

Beef was dry aged for 40-60 days under controlled environmental conditions in a refrigerated room with a relative humidity of 75%-80% and air-flow. To date, there is little information on the microbial diversity and characteristics of dry aged beef. In this study, we explored the effect of change in meat microorganisms on dry aged beef. Initially, the total bacteria and LAB were significantly increased for 50 days during all dry aging periods. There was an absence of representative foodborne pathogens as well as coliforms. Interestingly, fungi including yeast and mold that possess specific features were observed during the dry aging period. The 5.8S rRNA sequencing results showed that potentially harmful yeasts/molds (Candida sp., Cladosporium sp., Rhodotorula sp.) were present at the initial point of dry aging and they disappeared with increasing dry aging time. Interestingly, Penicillium camemberti and Debaryomyces hansenii used for cheese manufacturing were observed with an increase in the dry aging period. Taken together, our results showed that the change in microorganisms exerts an influence on the quality and safety of dry aged beef, and our study identified that fungi may play an important role in the palatability and flavor development of dry aged beef.

• 한국수산과학회지
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• 제52권3호
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• pp.232-240
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• 2019

Approximately 80% of the world's sea cucumbers Apostichopus japonicas are processed into dried sea cucumbers. The hot air-drying method is currently used in industry, but it has many problems, such as a short drying time, severe browning, high nutrition loss, and low recovery. In this study, the moisture absorption rate, dry recovery rate, and lipid nutrient composition of sea cucumber dried by heat pump decompression and with a hybrid dryer were investigated. The moisture absorption rates for hybrid-dried sea cucumbers at 24, 48, 72, 96, and 120 h were 241.3%, 427.7%, 652.0%, 721.0%, and 742.2%, respectively. The moisture absorption rates for hot air-dried sea cucumbers were 155.8%, 240.0%, 390.3%, 655.5%, and 667.4%, respectively. Thus, moisture absorption was faster and greater with hybrid drying than with hot air drying. The dry recovery rate at 24 h was greater for hybrid-dried sea cucumber (70.7%) than for hot air-dried sea cucumber (59.8%). Saturated fatty acid contents of the hybrid- and hot air-dried sea cucumbers were 30.0% and 37.5%, respectively. Moreover, greater ${\Sigma}n-3$ polyunsaturated fatty acid content was found in hybrid-dried sea cucumber (15.8%) than in hot air-dried sea cucumber (11.7%).

• 펄프종이기술
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• 제43권3호
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• pp.98-105
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• 2011

Patterns and levels of aging vary between the book volume and sheets, even though both are made from the same paper materials. In case of book format, the outside is more easily affected than inner side by environmental factors such as temperature, humidity and air. In this study, the change in optical properties after dry heating accelerated aging was comparatively analyzed to understand the difference of the optical aging characteristics between outside and inner side of the duplicated beeswax-treated volume. It is found that the cover pages of the beeswax-treated volumes were more optically deteriorated than their middle pages. This indicates that outer sides of aging book volume directly exposed to the air is more vulnerable to serious deterioration than inner sides. Also, aromatic compounds such as benzoic acid and cinnamic acid were observed in the investigation of UV/VIS absorbance of the beeswax in each aged sample.