• 한국가금학회지
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• 제43권4호
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• pp.197-206
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• 2016

본 연구는 냉동과 해동 방법에 따른 토종오리고기의 육질특성을 비교하기 위해 수행하였다. 본 시험에 사용된 공시재료는 8주령 토종오리(평균체중 2.8 kg)를 도압(屠鴨)하여 채취한 가슴육을 이용하였다. 본 시험의 처리구는 냉동 전 신선육을 대조구(CON)로 하고, 시험구는 냉동 2처리(급냉(FF), 완냉(SF)와 해동 2처리(급해동(FT), 완해동(ST))의 $2{\times}2$ 복합요인으로 4처리구로 하여 총 5처리구(CON, FFFT, FFST, SFFT, SFST), 처리구당 3반복, 반복당 3점씩 총 45점을 이용하였다. 급냉(시료를 $-50^{\circ}C$ deep freezer에서 보관)과 완냉(시료를 $-20^{\circ}C$ 냉동고에 보관)의 두 가지 방법으로 냉동된 시료를 1개월 저장 후, 급해동($12^{\circ}C$ 5시간의 유수해동)과 완해동($5^{\circ}C$ 24시간 냉장고 해동)의 두 가지 방법으로 해동하여 분석에 이용하였다. 육색 중 명도는 급냉시킨 경우와 급해동시킨 경우에 대조구에 비해 유의적으로 감소되었다(P<0.05). 황색도는 완해동시킨 경우에는 대조구에 비해 유의적으로 높게 나타났다(P<0.01). 물리적 성상 중 가열감량과 보수력은 대조구가 냉동과 해동 처리구에 비해 낮게 나타난 반면에(P<0.01, P<0.05), 전단력은 냉동과 행동 처리구에 비해 대조구에서 높게 나타났다(P<0.01). 화학적 성상 중 수분의 함량은 완해동한 경우에 급해동에 비해 높게 나타났으며(P<0.05), 단백질 함량은 급해동한 경우 대조구에 비해 유의적으로 높게 나타났다(P<0.05). Myristic acid(C14:0)와 linolenic acid(C18:3n3) 함량은 대조구에서 냉동과 해동 처리구에 비해 높게 나타났다(P<0.05). Stearic acid(C18:0) 함량은 완냉동시킨 경우에 급냉동의 경우보다 높게 나타났으며(P<0.05), 해동의 경우에는 처리구간 유의차를 보이지 않았다. Arachidonic acid(C20:4n6)은 완냉동과 완해동의 경우에 대조구에 비해 유의적으로 높게 나타났다(P<0.01, P<0.05). 필수아미노산 중 대조구의 threonine, glycine, iso-leucine, leucine, tryptophan 함량은 냉동과 해동 처리구에서 대조구에 비해 유의적으로 높은 함량을 나타내었다(P<0.05). Methonine과 valine 함량은 해동에 따른 차이는 보이지 않았으나, 냉동 처리시 대조구에 비해 유의적으로 높게 나타났다(P<0.05). 비필수아미노산 중 alanine, aspartic acid, glutamic acid, serine, tyrosine 함량은 대조구에서 냉동과 해동처리구보다 유의적으로 낮게 나타났다(P<0.01, P<0.05). 결론적으로, 토종오리고기의 냉동 및 해동은 수분과 관련된 육색, 전단력, 가열감량, 보수력에 영향을 미치는 것으로 보여진다.

• 대한영상의학회지
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• 제84권2호
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• pp.441-453
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• 2023

목적 네 가지 방법으로 토끼의 뇌에 VX2 세포를 이식하여 뇌종양의 생성 유무와 위치, 체적을 분석하고자 한다. 대상과 방법 공여 토끼를 희생하여 얻은 VX2 세포 현탁액을 1) 당일 이식, 2) 냉장 보관 7일 후 이식, 3) 초저온 냉동보관 7일 후 이식, 그리고 4) 공여 토끼를 희생하지 않고 조직생검 기구를 이용하여 VX2 세포현탁액을 얻은 후 당일 이식하였다. 뇌 이식에는 정위 기구를 사용하였으며 하방 레버를 이용하여 5 mm 진입하여 VX2 세포 현탁액을 주입하였다. 10일 경과 후 MR imaging을 실시하였으며 다음 날 뇌 조직을 얻어 조직검사를 실시하여 MR 영상과 현미경 검사상 뇌종양의 생성 유무와 위치, 체적 등을 살펴보았다. 결과 VX2 세포 현탁액을 당일 이식한 토끼(n = 18)에서는 17마리(94.4%)에서 뇌종양이 생겼다(평균 체적은 106.32 mm³). 냉장 보관 후 7일에 세포 현탁액을 만들어 뇌 이식한 토끼(n = 5)에서는 1마리(20%)에서 뇌종양이 생겼으나 현미경으로만 확인되었다. 초저온 냉동 보관 후 7일에 세포 현탁액을 만들어 뇌 이식한 토끼는 5마리에서는 3마리(60%)에서 뇌종양이 생겼고 현미경으로만 확인되었다. 생검 횟수를 10회 실시한 후 이식한 3마리에서는 뇌종양이 생기지 않았고, 20회 실시한 후 이식한 2마리에서는 모두 뇌종양이 생겼으며 MR 영상과 조직검사에서 확인되었다(평균 체적 38.71 mm³). 네 가지 방법으로 발생한 종양의 위치는 superficial cortex가 대부분이었다. 결론 VX2 세포를 이식하여 토끼의 뇌종양 모델을 제작하는 기법은 쉽고 재현성은 다양했다. 이 모델은 뇌종양에 대한 영상, 치료 방법, 중재 시술 및 약물 전달 등 다양한 연구에 활용될 수 있을 것이다. 연구자의 처한 다양한 환경에 따라 다양한 방법으로 VX2 세포를 이식할 수 있을 것으로 생각된다.

• Journal of Microbiology and Biotechnology
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• 제10권3호
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• pp.327-332
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• 2000

Supended cells of Camptotheca acuminata were observed to lose their ability to synthesize camptothecin and its derivatives as a result of repeated cultures. Accordingly, the maintenance of high-yield cells by cryopreservation was sudied to overcome this stability problem, and various factors involved were optimized. Pregrowing the cells in 8% myoinositol for 4 days was found to be the most effective in improving survival. The highest survival was obtained when the pregrown cells were cryoprotected with a mixture of 10% DMSO, 0.6M mannitol, and 10% glycerol. When the cryopreserved cells were maintained in a freezer at $-70^{\circ}C$, 94% survival was obtained after 4 months. The survivals after 5 and 8 months of storage decreased to 52% and 45%, respectively. No loss of biosynthetic capacility of camptothecin was observed after short to medium term cryopreservation of C. acuminata.

• 설비공학논문집
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• 제17권11호
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• pp.974-980
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• 2005

The optimization of design factors on the frosting performance of a fin-tube heat exchanger is carried out using Taguchi method. The fin spacings of the heat exchanger are selected as design factors. Optimum values of the design factors under operating conditions of a household refrigerator/freezer are proposed. The average heat transfer rate and operating time of the optimum models, compared to those of a reference model, are increased at most by $6.5\%$ and $12.9\%$, respectively.

• 한국식품조리과학회지
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• 제11권5호
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• pp.494-502
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• 1995

The study was conducted to evaluate the characteristics of Nuhbiani qualities with the different cooking, reheating methods and storage conditions. Cooking and reheating methods were used with pan, microwave and their combinations. Precooked samples were stored for 0, 1, 4, 7, 15 days in the refrigerator and for 15, 30 days in the freezer. TBA value, shear value by rheometer and sensory attributes in rancidity, hardness, juiciness and overall acceptability were measured. There was no significant difference between cooking, reheating methods in TBA values. Lower values in TBA were noted in the Nuhbiani of frozen storage as compared with that of refrigerated storage. There is a tendency that TBA values were increased as the storage time extended during the refrigeration. Shear values were more increased by microwave cooking and microwave reheating than other methods showing harder texture. Results from sensory evaluation of rancidity, hardness, juiciness and overall acceptability show that there were no significant differences between storage methods, among storage periods and cooking, reheating methods.

• Archives of Plastic Surgery
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• 제43권6호
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• pp.595-598
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• 2016

The use of human vessels at the beginning of microsurgery training is highly recommended. But vessels with the appropriate length for training are not often obtained. Whether these vessels may be reused for training has not been reported. Accordingly, we harvested vessels from discarded tissues in lymph node dissection and demonstrated that vascular anastomosis training using the same human vessels several times is possible by placing the vessels in a freezer and defrosting them with hot water. Vascular walls can be stored for microsurgical training until about 4 years after harvest, as shown in the gross appearance and histologic findings of our preserved vessels. We recommend the technique presented here for the long-term reuse of human vessels for microsurgery training that closely resembles real procedures.

• 한국생산제조학회지
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• 제22권4호
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• pp.723-729
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• 2013

The contraction and expansion noise of a refrigerator are investigated, and some effective methods are proposed to reduce the level and occurrence frequency of noise. First, the noise of a refrigerator is measured to estimate the frequency spectrum and occurrence frequency of noise. Second, a sound visualization was conducted using an acoustic camera to determine the location of the noise source. From the results, it was observed that the internal part mainly producing noise was the third shelf in the freezer room. A method to estimate the acceleration on the location of the noise source is introduced to analyze the contraction and expansion noise precisely and accommodate experimental convenience. Noise reduction methods such as the replacement of the existing shelf with glass shelves, adoption of rail slides, and increase of roughness on the contact surface of the shelf are proposed and tested.

• 한국가축번식학회지
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• 제12권2호
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• pp.77-83
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• 1988

This study was done with mouse embryo to assess effects of freezing media containing sucrose, freezing metods(1-F, 0.3$^{\circ}C$/min;2-F, 3-5$^{\circ}C$/min;3-F, 15$^{\circ}C$min;4-F, LN2 vapour) and cell freezers on the embryo survival determined using the FDA test. The results are summarized as follows. 1. The FDA score obtained with 1, 2, 3 and 4-F was 3.8, 3.6, 3.2 and 3.2, respectively. There was a significant difference(P<0.05) between 1-F, 3-F and 2-F, 4-F. 2. The score at the morular stage(3.8) higher(P<0.005) than the blastocyst stage of embryos(3.2). 3. No difference (P>0.05) was found between the score obtained with a automatic embryo freezer(4.0) and a liquid nitrogen container(3.7).

• 한국기계가공학회지
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• 제18권12호
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• pp.98-103
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• 2019

With the increasing need for environmental protection, it is particularly important to improve the energy saving and reliability of refrigerators. Generally, the cold air flowing into the freezer compartment transits to the bottom of the refrigerating compartment, which can lead to uneven temperature distribution. This paper proposes two design solutions for improving the temperature distribution problem. Of these, the optimal refrigeration design was selected and tested using Computational Fluid Dynamics (CFD) modeling and simulation. The results showed improved uniformity of the temperature distribution inside the refrigerator, thus benefitting food storage while reducing energy consumption.

• 한국수소및신에너지학회논문집
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• 제27권2호
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• pp.236-243
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• 2016

This paper presents a simple thermo-physical model of reciprocating compressors for household refrigerator-freezers. The compressor model has been developed based on thermodynamic principles and large data sets from the compressor calorimeter tests. The input data are compressor geometry (displacement and clearance volume), compressor speed, suction pressure and temperature, discharge pressure, and ambient temperature. The model can estimate mass flow rate and compressor power consumption within 3.0% accuracy, which is not much larger than measurement errors associated with calorimeter testing under ideal conditions.