• 한국가금학회지
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• 제46권4호
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• pp.223-234
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• 2019

This study investigated the effects of thawing methods and storage time on the quality of frozen duck meat. Meat was obtained from eight-week-old Korean native ducks (average weight=2.8 kg). Seventy-two samples were divided into eight treatments (three replicates/treatment, three samples/replicate) with 2 × 4 factorial arrangement based on two thawing methods (under running water at 12℃ for 3 h and in a refrigerator at 5℃ for 24 h) and four storage times (1, 3, 6, and 12 months). CIE b^* was significantly different among different storage time treatments, reaching its lowest after 6 months (P<0.05). Cooking loss did not differ between storage times; however, it was significantly lower following application of the fast thawing treatment (P<0.05). Water-holding capacity of meat stored for one month was highest compared to that of meat stored for a longer period (P<0.05). Additionally, there were significant differences based on storage time in γ-linoleic acid (C18:3n6) and eicosenoic acid (C20:1n9) contents (P<0.01), as well as in protein contents (P<0.05). Palmitoleic acid (C16:1n7) typically decreased after three months of storage; however, this decline was not significant compared to other storage times. Essential amino acids contents, except methionine, were significantly difference at six and 12 months of storage (P<0.05). Similarly, non-essential amino acid contents, except tyrosine, were significantly different among storage periods (P<0.05, P<0.01). Alternatively, there were no significant differences in the chemical composition, fatty acid content, or amino acid content based on the thawing method.

• 한국축산식품학회지
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• 제29권5호
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• pp.579-589
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• 2009

This study was conducted to investigate the effects of heating, fiber type used in solid-phase microextraction (SPME, two phase vs three phase) and storage time on the volatile compounds of porcine M. longissimus dorsi (LD). Volatile compounds were measured using a gas chromatography and mass spectrometry (GC/MS) with a quadrupole mass analyzer. Among the volatile compounds identified, aldehydes (49.33%), alcohols (24.63%) and ketones (9.85%) were higher in pre-heated loins ($100^{\circ}C$/30 min), whereas, alcohols (34.33%), hydrocarbons (22.84%) and ketones (16.88%) were higher in non-heated loins. Heating of loins induced the formation of various volatile compounds such as aldehydes (hexanal) and alcohols. The total contents of hydrocarbons, alcohols, and carboxylic acids were higher in two phase fibers, whereas those of esters tended to be higher in three-phase fibers (p<0.05). Most volatile compounds increased (p<0.05) with increased storage time. Thus, the analysis of volatile compounds were affected by the fiber type, while heating and refrigerated storage of pork M. longissimus dorsi increased the volatile compounds derived from lipid oxidation and amino acid catabolism, respectively.

• The Journal of Advanced Prosthodontics
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• 제8권5호
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• pp.380-387
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• 2016

PURPOSE. The storage conditions of impressions affect the dimensional accuracy of the impression materials. The aim of the study was to assess the effects of storage time on dimensional accuracy of five different impression materials by cone beam computed tomography (CBCT). MATERIALS AND METHODS. Polyether (Impregum), hydrocolloid (Hydrogum and Alginoplast), and silicone (Zetaflow and Honigum) impression materials were used for impressions taken from an acrylic master model. The impressions were poured and subjected to four different storage times: immediate use, and 1, 3, and 5 days of storage. Line 1 (between right and left first molar mesiobuccal cusp tips) and Line 2 (between right and left canine tips) were measured on a CBCT scanned model, and time dependent mean differences were analyzed by two-way univariate and Duncan's test (${\alpha}=.05$). RESULTS. For Line 1, the total mean difference of Impregum and Hydrogum were statistically different from Alginoplast (P<.05), while Zetaflow and Honigum had smaller discrepancies. Alginoplast resulted in more difference than the other impressions (P<.05). For Line 2, the total mean difference of Impregum was statistically different from the other impressions. Significant differences were observed in Line 1 and Line 2 for the different storage periods (P<.05). CONCLUSION. The dimensional accuracy of impression material is clinically acceptable if the impression material is stored in suitable conditions.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 1993년도 Proceedings of International Conference for Agricultural Machinery and Process Engineering
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• pp.922-931
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• 1993

Boundary element method was used to solve heat conduction problem for predicting temperature distribution in grain storage bin. Temperature of grain in storage is one of the three main abiotic factors, besides the intergranular gas composition and the grain moisture content, that determine the keeping quality and control measures used to protect grain from insects and damaging microflora. Collecting the temperature data at various points in the storage bins at different time of the day over a period of time is one way of finding the temperature distribution, this method requires a lot of time, cost and labour and less efficient. However data so collected serve useful purpose of being used to validate predicted temperature distribution using mathematical models. Mathematical models based on physical principles can potentially predict with accuracy the temperature distribution in a grain storage bin. Using the boundary element model the effect of bin wall material, ambient emperature, bin size etc. on temperature distribution can be studied. A knowledge of temperature distribution in stored grain not only helps in identifying active deterioration , but also gives an indication of potential for detection.

• 한국수자원학회논문집
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• 제37권4호
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• pp.257-271
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• 2004

본류대를 따라 저장대가 주기적으로 존재하는 다중저장대모형을 개발하고 자연하천의 혼합거동을 해석하였다. 개발된 모형 및 하나의 저장대를 갖는 기존의 저장대모형을 비교하기 위하여 모형실험 결과를 이용하였다. 본 모형을 이용하여 구한 농도분포는 모형실험에서 수집된 시간에 따른 농도분포를 잘 재현하는 반면, 연속적인 저장대를 갖는 기존모형은 불연속적인 저장대 구조로 인해 발생하는 농도분포의 부차적인 융기부분을 정확히 재현하지 못하는 것으로 나타났다. 본 모형의 현장 적용성을 검토하기 위하여 새로운 모형을 미국 미네소타주에 위치한 Shingobee River에 적용하고 혼합거동을 해석한 결과 새로운 저장대 모형은 저장대가 존재하는 자연하천에서의 분산거동을 정확하게 모의하는 것으로 나타났다.

• 동아시아식생활학회지
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• 제20권6호
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• pp.888-895
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• 2010

Riceyeotgangjung (RYG) with added spirulina was prepared with citron juice for masking of odor. Oil temperature for puffing was found to be $220^{\circ}C$ for frying dry rice based upon the results of expansion rate and color. RYGs with added spirulina (1, 2, and 3%) were prepared under the above conditions, and their physicochemical and sensory properties were examined under storage at $60^{\circ}C$ for 15 days. Moisture content of RYG decreased proportionally with the spirulina content and storage time. The hardness levels of the freshly made RYGs with spirulina were higher than that of control. During storage, the hardness of the control gradually increased, but those of the RYGs with spirulina gradually decreased, although no significant differences existed between the spirulina containing RYGs. Lightness and redness values in the Hunter color system decreased according to the spirulina content and storage time. Yellowness value also increased with the spirulina content and storage time. Phycocyanin and total phenolic content increased with spirulina content, but decreased with the storage period. Sensory evaluation results showed that RYG with 2% added spirulina received the highest scores for color, taste, overall acceptability, and intention of purchase. As a result, the optimal addition amount of spirulina to RYG is recommended to be 2%.

• 한국식생활문화학회지
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• 제35권5호
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• pp.450-458
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• 2020

This study examined the optimal temperature and time conditions to maintain high quality Dongchimi during the fermentation and storage period. Dongchimi was fermented at low (5℃), medium (10 and 15℃), and high (20℃) temperatures until the acidity reached 0.2, 0.3, and 0.4%. respectively. From the consumer's preference test enrolling five consumers, Dongchimi fermented at 15℃ until an acidity of 0.3% (for approximately six days) was evaluated to be the optimal status because of its high score of overall acceptance, taste, and odor of consumers. To determine the optimal storage temperature of fermentation, Dongchimi was stored at three different temperatures (-1, 2, 5℃) for four weeks after fermenting at 15℃ for six days. During the storage period, most of the physicochemical properties (pH, acidity, reducing sugar content, and organic acid) and microbiological properties changed significantly in the 2 and 5℃ groups, resulting in a significant change in descriptive sensory analysis of Dongchimi. These results indicate that fermentation at 15℃ and storage at -1℃ for Dongchimi enables it to maintain the best quality for a long time.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2009년도 하계학술발표대회 논문집
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• pp.990-995
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• 2009

Experimental basic study was performed to understand the characteristics of sub-cooled refrigerant using a cold heat storage system. This system was made up general vapor-compression refrigeration cycle added sub-cooler and ice storage tank. The purpose of this study are to application use of cold-heat storage systems multiplicity of fields and to understand of sub-cooling system. At the condition using ice storage system, the ice making process was operated during night time by electric power. And then, the refrigerant was sub-cooled using stored cold-heat after being discharged from the air cooling condenser during the day time. Comparing the result at general operation with the operation using sub-cooling system. This study showed the effects of the sub-cooled degree. The cooling performance was increased owing to the sub-cooling of refrigerant during day time, and the compressor consume power was a little decreased. Thus the COP was also increased owing to the sub-cooling of refrigerant.

• 상하수도학회지
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• 제27권6호
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• pp.711-721
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• 2013

Optimal operation of a combined sewer network with distributed storage facilities aims to use the whole retention capacity of all reservoirs efficiently before overflows take place somewhere in the considered network system. An efficient real-time network control (RTNC) strategy has been emerging as an attractive approach for reducing substantially the overflows from a sewer network compared to the conventional fixed or manually adjusted gate setting method, but the related concrete framework for RTC development has not been throughly introduced so far. The main goal of this study is to give a detailed description of the RTNC systems via reviewing several guidelines published abroad, and finally to suggest methods for the proper application of RTNC on distributed storage facilities. Especially, this study is focused on emphasizing the importance of hierarchical structure of RTNC system that consists of three control layers (management, global control and local control). Further, with regard to the global control layer which is responsible for the central overall network control, the wide-ranging details of two components (adaption and optimization layers) are also presented. This study can provide the valuable basis for the RTNC implementation in the particular sewer network with distributed multiple storage facilities.

• 설비공학논문집
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• 제18권4호
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• pp.287-296
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• 2006

In this paper, optimal control strategy of the air-conditioning system with slab thermal storage was investigated based on the optimal control theory. An optimal heat output to the plenum chamber and the air-conditioned room was determined based on two kinds of criterion functions. The first one requires small deviation in room air temperature from a set-point value and low energy consumption. It is shown that the optimized control is to store heat through the whole storage time and to increase storage rate gradually with time. As the second case, a criterion that both a deviation of operative temperature from a set-point temperature and the energy consumption should be minimized was adopted. The room air temperature was a little high and the cooling load during storage time was reduced, compared with the results when a criterion function considering only the room air temperature is used.