• Journal of Advanced Marine Engineering and Technology
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• 제24권4호
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• pp.509-514
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• 2000

A numerical study has been performed to design duct parameters in the freezer of a domestic refrigerator. The visualization results of FDM analysis using the standard k-$\varepsilon$ model with inlet boundary conditions modelled in this paper show good agreements with the experimental ones in prediction overall flow characteristics. Dominant vortex flows are found in the left upper and right lower corners, while there exists large turbulent kinetic energy around the fan and right upper side of the fan. It, in turn, has effects on the performance and noise. It is recommended to locate the outlet far away from the fan in order to reduce the noise level.

• 대한기계학회논문집B
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• 제35권7호
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• pp.743-748
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• 2011

R-134a 대체 냉매인 HFO-1234yf의 성능을 가정용 냉동/냉장고에서 평가하였다. AHAM(Associ- ation of Home Appliance Manufacturers) 규격에 의거하여 HFO-1234yf를 Drop-in하여 냉매 봉입량 시험, Pulldown 시험, 냉각속도 시험 그리고 소비전력 시험을 수행하였으며, R-134a 실험 결과와 비교하였다. $43^{\circ}C$ 고온 가혹 조건에 서도 시험을 수행하였다. 결과적으로 HFO-1234yf 냉매는 Cycle 성능면에서는 R-134a와 유사하나, 냉각속도는 모세관경을 더 크게 변경시켜야 한다.

• Journal of Biosystems Engineering
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• 제39권4호
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• pp.330-335
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• 2014

Purpose: This study was conducted for enhancing the performance of a conventional quick freezer by introducing the supercooling state, using a low-temperature coolant. Methods: In the present investigation, the supercooling process was executed prior to quick freezing for reducing the time by which the temperature passes the zone of maximum ice crystal formation. Every food has different nucleation points and hence, we used silicone oil as the coolant for supercooling for easy modification of temperature. Additionally, for quick freezing, we used liquid nitrogen spray. Results: Using the heat exchanger-type precooler with silicone oil, the temperature of the chamber was easily changed for enabling supercooling. Particularly, the results of the freezing test with garlic indicated that this system improved the hardness of garlic after it was thawed, compared to the conventional freezing method. Conclusions: Before quick freezing, if the food item is subjected to the supercooling state, the time from nucleation to the temperature reaching the frozen state ($-5^{\circ}C$, which is the maximum ice crystal formation zone) will be shorter than that incurred using quick freezing alone. The combination of the heat exchanger-type supercooler and liquid nitrogen sprayer is expected to serve as a promising technology for improving the physicochemical qualities of frozen foods.

• Journal of Pharmaceutical Investigation
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• 제30권1호
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• pp.21-26
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• 2000

Bioavailability of ipriflavone (3-phenyl-7-isopropoxy-4H-I-benzopyran-4-one, IP), an antiosteoporotic drug with poor water-solubility, was studied for various types of pharmaceutical preparation in SD rats. The IP preparation types included (1) intact IP, (2) freezer milled IP (FIP), (3) freezer milled IP physically mixed with freezer milled poly-N-vinylpyrrolidone (PVP) (FIP+FPVP) and (4) spray-dried IP with PVP (SIP). Upon oral administration, SIP showed significantly higher absorption and elimination half-lives and the lag time $(t_{lag})$ than those of FIP+FPVP (approximately 2-fold). These results may be due to a sustained releasing effect of IP in the gastrointestinal tract by spray-drying with PVP. The $C_{max}$ of SIP was about 2 and 10 times higher than those of FIP+FPVP and FIP, respectively. The AUC of SIP was about 6 times higher than that of FIP+FPVP and 60 times that of FIP. Scanning electron microscopy (SEM) showed that SIP consisted of the finest particle size and minimal aggregation than other IP preparations. It is concluded that the IP formula prepared by the spray-drying method with PVP is the most effective approach to the improvement of bioavailability of IP.

• 한국균학회지
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• 제42권2호
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• pp.97-103
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• 2014

농업미생물은행(KACC)에는 7,039균주의 곰팡이가 장기 보존되어 있다. 이 중에서 다수의 포자를 형성하는 4,065균주는 동결건조법으로 보존되어 있는데 사멸로 인한 균주의 소실을 막기 위하여 대부분은 액체질소보존법 그리고 모든 균주가 저온냉동고보존법으로 함께 보존되어 있다. 4,065균주의 곰팡이에는 주로 공기 중에 흔하며 산업적으로 이용성이 많은 Aspergillus, Penicillium, Lichtheimia, Mucor, Rhizopus 속 등이 포함된다. 포자를 형성하지 않거나 소수형성하거나 또한 보존이 어려운 너무 큰 포자를 형성하는 나머지 곰팡이는 동결건조보존법으로 보존이 불가하기 때문에 액체질소보존법, 저온냉동고보존법 그리고 광유보존법으로 균주를 보존한다. 여기에는 Phytophthora, Pythium, Cercospora, Septoria, Rhizoctonia 속 등의 식물병원균이 포함된다. 이 외에도 KACC에서 이용하는 다양한 곰팡이 보존법을 소개하고 이들의 상세보존 과정을 기술한다.

• 대한조선학회논문집
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• 제52권1호
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• pp.19-24
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• 2015

The economic efficiency for fishery products can be related to their freshness and the quality. In order to freshly storage the product, freezing equipment system is necessary for fishing vessels. For this purpose, the horizontal plate freezer (HPF) is mostly used. In this research, our major objective is to improve the freezing performance of the HPF. Therefore, it is important to analyse the relationship between the shape of channels and the cooling temperature of the HPF. In order to save calculation time while checking the trend analysis between shape and performance, we used scaled models, and evaluate the cooling temperature of full scale model based on trend analysis results. The produced HPF in domestic was used, and the same operating conditions are considered. Based on this paper, the future research will be a comparison and verification through the experiments.

• 한국관광식음료학회지:관광식음료경영연구
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• 제15권2호
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• pp.57-72
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• 2004

This study is carried out to investigate the effect of any periods in the freezer and the product of value, moisture content, baking loss, specific volume loaf in manufncturing process thereof. The moisture content of the croissant slightly decreased as the periods passed in the freezer. And as passed periods frozen croissant dough dried naturally by the freezer fan. 1. As frozen periods passed croissant dough decreased moisture content and loaf volume. The volume is relation to the molsture content and croissant dough' gluten. Yeast is active but croissant dough is dried so pastry margarine's moisture vaporized little by little. 2. 1 day frozen bench time provided maximum specific loaf volume while croissant shape was unsettled, moisture content was highest. At the same dough croissant hardness had very sofi crust. 3. 1week and 2weets frozen dough had specific loaf volume and hardness with proper crust color. As the proper bench time provided best shape of croissant, color. 4. 4weeks and 8weeks frozen dough had over-al] value of croissant accelerating older product. As the same result, over Sweets frozen periods product were not available for sale and serving to customers. 5. By the sensory evaluation tests, over-all croissant as 1 week, 2weeks were significantly higher quality those than 6. 1day, 4weeks and 8weeks. Textural properties of croissant over 4weeks frozen periods so hard for every panel. According to the study, not croissant dough but also any other frozen dough(ex.Danish, brioche etc.)have to need proper bench time and 1week or 2weeks circulation making method have to given encouragement to practical pastry industry. Add to this study using only for frozen dough yeast instead of using fresh and instant

• 한국식품과학회지
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• 제31권6호
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• pp.1589-1595
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• 1999

생강 추출액의 저장안정성을 제공하기 위하여 적정농축 및 건조방법을 선정코자 감압증류 및 RO(역삼투압)에 의한 농축과 냉동 및 분무건조방법별로 분말화한 다음 관능특성을 비롯한 이화학적인 품질특성을 비교하여 보았다. 농축 및 건조방법별 분말제품을 제조한 결과 갈변도는 감압증류법이 RO보다. 분무건조가 냉동건조보다 갈변이 덜 진행된 상태인 반면에 당 함량이나 유리아미노산은 농축방법의 영향을 인식할 수 없었으나 건조방법에 있어서는 냉동건조시 대체로 이들 성분의 손실율을 적게할 수 있었다. 효소적 액화추출액 분말은 생강 추출액 분말보다 단백질과 조회분함량이 낮은 반면 조지방 함량은 약간 높게 나타났으며, 농축 및 건조 중 갈변도와 유리 아미노산의 변화율을 생강 추출액 분말보다 억제하면서 용해도를 증가시킬 수 있는 효과가 있었다. 또한 생강분말에 대한 기호도 검사결과, 농축방법에서는 생강 추출액 및 효소적 액화추출액에서 RO농축한 제품이 우수한 결과를 보였으며 건조방법에서는 냉동건조가 우수한 결과를 나타내었다. 특히 효소적 액화 추출액의 경우에는 RO농축한 후 냉동건조하면 종합 기호도에 있어서 생강추출액 분말에 대한 기호도 특성과 거의 차이가 없는 것으로 나타났다.

• 한국식생활문화학회지
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• 제34권3호
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• pp.343-352
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• 2019

The aim of this study was to optimize the best recipe to make acorn bread containing milk as a functional food. The color value, textural, and sensory properties of the acorn bread added with 10~40% ratio of milk were measured to develop the best recipe. As a result, the L-value of color increased with the amount of milk added, but the a- and b-values decreased. As the textural measurement, the hardness increased with increasing milk added. Cohesiveness and springiness decreased, but the gumminess and brittleness increased with the addition of 20% milk, and decreased with further addition. The sensory evaluation revealed color, taste, and overall acceptances to have high scores at 20% addition of milk. Softness and chewiness were good at 10% addition. During the storage periods at room temperature, the L- and b-values increased with the addition of milk, whereas a-value decreased. In freezer storage, the L-value increased with milk content added, but the a- and b-values decreased during the storage periods. The textural properties increased during the storage at room temperature. The addition of milk decreased the cohesiveness and springiness, but the gumminess and brittleness increased significantly after one day storage. In freezer storage, all textural properties increased significantly during the storage periods, but the hardness decreased after two days storage. With the increasing amount of milk added increased the cohesiveness, springiness, and the gumminess except for four days, but decreased hardness and brittleness after two days storage. Therefore the addition of milk in acorn bread improved the textural properties significantly.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2004년도 동계학술대회 논문집
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• pp.94-94
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• 2004