• Food Science and Preservation
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• v.20 no.3
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• pp.296-303
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• 2013

This study was conducted to assess the possibility of preserving frozen vegetables (Aster scaber, soybean sprouts, Chinese cabbage, green pumpkin, and Welsh onion) for a long period and of using them after such storage by measuring changes in quality due to their preservation. Various freshly harvested vegetables were blanched under optimal conditions (that were determined in a preliminary experiment), quick-frozen at $-40^{\circ}C$ for 24 h, and stored at $-20^{\circ}C$. The change in the chromaticity of the frozen A. scaber, soybean sprouts, Chinese cabbage, green pumpkin, and Welsh onion did not vary. The hardness of the frozen A. scaber, green pumpkin, Chinese cabbage and Welsh onion did not change during the preservation period, whereas the hardness of the cotyledon and hypocotyl of the soybean sprouts significantly increased on the sixth month of their storage. The total bacterial counts of the A. scaber during the preservation period remained constant at $10^3$ CFU/g, whereas those of soybean sprouts, Chinese cabbage, green pumpkin, and Welsh onion decreased slightly to $10^2$ CFU/g. Coliform was not detected in any of the samples. The sensory evaluation showed that the preservation period that was used in this study did not significantly affect the marketability of the frozen vegetables. Therefore, it was considered that A. scaber, soybean sprouts, Chinese cabbage, green pumpkin, and Welsh onion can be safely preserved by freeze-storing them for up to 12 months.

• 대한생식의학회:학술대회논문집
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• 2004.11a
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• pp.90-90
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• 2004

• Anatomy & Biological Anthropology
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• v.31 no.4
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• pp.133-142
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• 2018

3D histology is a imaging system for the 3D structural information of cells or tissues. The synchrotron radiation propagation phase contrast micro-CT has been used in 3D imaging methods. However, the simple phase contrast micro-CT did not give sufficient micro-structural information when the specimen contains soft elements, as is the case with many biomedical tissue samples. The purpose of this study is to develop a new technique to enhance the phase contrast effect for soft tissue imaging. Experiments were performed at the imaging beam lines of Pohang Accelerator Laboratory (PAL). The biomedical tissue samples under frozen state was mounted on a computer-controlled precision stage and rotated in $0.18^{\circ}$ increments through $180^{\circ}$. An X-ray shadow of a specimen was converted into a visual image on the surface of a CdWO4 scintillator that was magnified using a microscopic objective lens(X5 or X20) before being captured with a digital CCD camera. 3-dimensional volume images of the specimen were obtained by applying a filtered back-projection algorithm to the projection images using a software package OCTOPUS. Surface reconstruction and volume segmentation and rendering were performed were performed using Amira software. In this study, We found that synchrotron phase contrast imaging of frozen tissue samples has higher contrast power for soft tissue than that of non-frozen samples. In conclusion, synchrotron radiation propagation phase contrast cryo-microCT imaging offers a promising tool for non-destructive high resolution 3D histology.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.10 no.1
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• pp.23-29
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• 1977

Three kinds of samples, Trachpenalus curiviostris, Astroconger myriaster and Cantherines modestus which were pre-treated in a processing plant were frozen at $-40^{\circ}C$ in a contact freezer and stored for 32 days.The numbers of general bacterium, coliforms and E. coli were measured at 8 day intevals during frozen storage and the isolated strains was classified. The results are as follows; 1. The numbers of coliforms and E. coli in the samples before freezing were much higher, than those during frozen storage and it tended to decrease. 2. General bacteria showed little change in number before and after being frozen. Among 97 strains of isolated coliforms, only 4 strains of K. aerogenes I ana 4 strains of K, cloacae were classified and the rest was not determined. 3. Ninety percent of coliforms was found to be psychrotrophic coliforms, which were able to grow at $5^{\circ}C$ within a week. 4. Vibrio and Pseudomonas were superior in number before freezing while Flavobacterium cytophaga and Moraxella were superior during frozem storage.

• Korean Journal of Animal Reproduction
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• v.22 no.2
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• pp.187-194
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• 1998

In order to determine suitable conditions for rapid freezing of porcine embryos, the kind and concentration of cryoprotectants, sucrose concentrations, equilibration time and thawing temperature in freezing medium were examined in relation to the survival of frozen-thawed oocyte and embryos. The results obtained are as follows : 1. The suitable concentrations of cryoprotoctant in the freezing medium which consisted of TCM-199+20% FCS were 1.5M for glycerol, 2.0M for DMSO, 2.5M for ethylene glycol, and 2.0M for propanediol. The sucrose concentration of 0.25M in the medium was found to optimal because the survival rate was markedly higher at this concentration when compared to the others. The survival rate was relatively high when the frozen embryos were thawed at 30$^{\circ}C$ in the freezing medium containing 2.5M cryoprotectants. The equilibration periods of 2.0 and 5.0 minutes revealed the higher survival in the media containing 1.5 or 2.1M glycerol when compared to 10 and 15 minutes. 2. The fertilization rates of frozen-thawed follicular oocytes which matured in vitro for 1, 12, 24 and 48 hours were 6.7~26.7% depending on the maturation time, and the rates were relatively high for those matured for a short period of time. The survival rates of frozen-thawed oocytes which matured in vitro for certain periods and fertilized were 10.0~30.0% depending on the maturation time.

• Proceedings of the KAIS Fall Conference
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• 2005.05a
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• pp.159-162
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• 2005

전자빔을 이용하던 CRT(Cathode Ray Tube) 모니터에서 픽셀단위의 LCD(Liquid Crystal Display) 디스플레이 사용으로 휴대용 정보처리 장치들은 급속한 발전을 이루게 되었다. 기존의 CRT 모니터에서 전자빔을 사용하던 방식에서 픽셀(Pixel) 단위의 후면발광 디스플레이를 만들면서 CRT 모니터보다 빠른 응답특성을 나타내며 저 전력일 뿐만 아니라 디스플레이의 두께도 줄일 수 있게 되었다. 휴대가 가능한 디스플레이의 발전으로 노트북이나 PDA와 같은 실시간 정보를 활용 및 처리 할 수 있는 방법들을 제시할 수 있었지만 원활한 활용을 위해 더 적은 전력을 사용하는 방법들이 제시되어야 했다. 이에 따라 저 전력 소모, 빠른 응답특성, 넓은 시야각 그리고 경량화가 가능한 디스플레이가 되기 위한 새로운 디스플레이가 선을 보이게 되었다. 현재 차세대 디스플레이로 각광을 받고 있는 디스플레이 소자로는 OLED(Organic Light Emitting Diode)가 있다 이는 LCD 디스플레이가 가지고 있는 단점을 보완하여 우선적으로 높은 색도가 가능하며 후면발광을 사용하지 않고 자체 발광을 하기 때문에 저 전력 소모가 현실화되었다. 또한 디스플레이의 유동성이 가능하여 휘어질 수 있는 특성을 가지고 있다. 그러나 이러한 유기발광 소자의 경우 높은 발광 효율을 위한 구조적 개선이 필요하며 소자의 수명도 개선해야 한다. 이에 따라 유기발광 소자의 메카니즘에 대한 파악이 필요하게 되며 물리적 구조에 대한 이해가 필요하다. 이를 위해 물리적, 수치적 해석으로 소자의 특성을 파악해 줌으로써 개선된 유기발광 소자 제작이 가능 할 것이다.기에 대한 영향정도를 측정하여 정량적으로 도출하였다. 이를 각 구간에 대해 상호 비교 분석함으로써 대형국책사업에서의 공기지연인자에 대한 분석 방법론을 정립하였고 공기지연 분석 방법론의 현실적 적용을 위한 제언과 그에 따른 개선사항에 대해 도출하였다.있는 발판을 마련하게 된다고 추정하였다. 0.5%가 control사이에서 0.95로 가장 색차가 크게 나타났으며, 그 다음이 냉동분쇄 0.5% 0.83으로 나타나 송이의 첨가율이 높을수록 색차가 크게 나타나는 것을 알 수 있다. 색차가 가장 낮은 제품은 법동분쇄 0.3%, 동결건조 0.3%로 나타났다. 송이양갱의 색(color), 냄새(flavor), 맛(taste), 외관(appearances), 질감(viscosity), 종합적 평가(overall acceptability) 등의 관능평가를 실시한 결과 중 색에 대한 기호도는 냉동분쇄 0.1% 송이양갱이 가장 높은 것으로 나타났으나, 집단간 유의한 차이는 나타나지 않았고, 냄새는 동결건조 0.1%의 송이양갱이 3.38로 가장 점수가 높았으며, 냉동분쇄 0.3%의 송이양갱이 2.81로 가장 낮은 기호도를 나타내었다. 맛에서는 p<0.01수준에서 집단간 유의한 차이를 나타내었는데, 동결건조 0.1%가 그 중 가장 높은 기호도를 나타내었으며, 그 다음이 동결건조 0.5%였다. 가장 낮은 선호도를 나타낸 것은 열풍건조 0.5%였다. 질감은 P<.05 수준에서 집단간 유의미한 차이를 나타내었으며 동결건조 0.1%가 가장 높은 기호도를 나타내었으며, 동결건조 0.5%함유 송이양갱이 1.21로서, 현저히 낮은 기호도를 나타내었다. 종합적인 평가에서는 동결건조 0.1%함유

• Magazine of the Korea Concrete Institute
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• v.10 no.4
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• pp.153-161
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• 1998

Concrete structures has been deteriorated by and freezing the thawing due to temperature gap. This study was conducted to evaluate durability of concrete which are increasingly demanded recently. Therefore the research of durability must be executed for application of waste foundry sand concrete real structures. Concrete durability properties incorporating waste foundry sand was performed with the variable of W/C ratio. Sand/Waste foundry sand ratio and Air entrainment-Non air entrainment. Cylinder specimens were made and subjected to freezing and thawing cycle at -18$^{\circ}C$ and 4$^{\circ}C$. Dynamic modulus of elasticity were evaluated as F/T cycle increase. The results show that strength of concrete is increased the W/C ratio decrease, the Sand/Waste foundry sand ratio increases when the concrete contains AE agent and decreasing W/C ratio and AE concrete makes improved resistance of freezing and thawing improved. Especially, resistance of freezing and thawing is improved by Fine aggregate/Waste foundry sand ratio which is 50%, 25%, 0% in a row. Therefore it is turn out the waste foundry sand could be applied to concrete from the experiment.

• Korean Journal of Animal Reproduction
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• v.25 no.4
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• pp.409-419
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• 2001

This study was to examine whether the in vitro friability, motility and intact acrosome of frozen-thawed bovine and human sperm can be improved by adding Pentoxifylline (PF) or Fertilization Promoting Peptide (FPP). Human semen was frozen ultra-rapidly using Test yolk-buffer (TYB) freezing medium. Additive (PF, FPP) effects in frozen-thawed bovine and human sperm were analyzed by microscopic count for sperm motility and coomassie brilliant blue staining method f3r sperm acrosome intact. The in vitro motility of frozen-thawed bovine sperm with 5 mM PF treatment group (50.0%) was significantly higher than that of control (34.0%) (P＜0.05). In the frozen-thawed bovine sperm was examined, the intact acrosome rate of 50 nM FPP treatment (49.0%) was significantly higher than those of control (30.0%) and 25 nM FPP (38.0%) treatment groups (P＜0.01). In human semen, when in vitro motility of sperm with PF addition prior to freezing was examined, the result of 5 mM treatment group (51.0%) was significantly higher than those of control and 2.5 mM treatment group (39.0, 40.0%) (P＜0.01). In addition, 50 nM (75.5%) FPP adding in all treatment procedures for human semen freezing (before freezing, freezing and after thawing) was significant effect on maintenance of the sperm intact acrosome percentage (control: 45.0; 25 nM: 53.0; 100 nM: 68.0%) (P＜0.01). Also, the intact acrosome rate of human sperm with FPP (65.0%) was significantly higher than that with PF (43.0%) (P＜0.05), although sperm motility was slightly higher in PF treatment group. These results suggest that improved sperm motility and intact acrosome of frozen thawed bovine and human sperm can be obtained by addition of PF or FPP, and that the enhanced in vitro viability, motility and intact acrosome can be obtained by addition of FPP in all semen freezing procedures.

• Applied Microscopy
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• v.28 no.1
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• pp.73-82
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• 1998

To elucidate how microfilaments and vesicles participate in bile formation, the pericanalicular cytoplasms were observed in the liver of rats treated with taurocholic acid by deep etching with rapid freezing, and copmpared them with the findings on convensional thin sections. The microfilaments were identified around the bile canaliculi in the forms of core filaments of microvilli, filaments of pericanalicular web running in parallel to the border of bile canaliculi, and filaments on the junctional complex. In taurocholic acid-treated rats, microfilaments could be visualized around the bile canaliculi and along their borders. The microfilaments appeared to be installed to link to both the canalicular membrane and vesicles. Such specialized microfilaments are considered to participate in the translocation of vesicles in the pericanalicular cytoplasm. From the evidence, it is assumed that the microfilament induces the vesicles to transport and fuse to bile canalicull into which bile acids is secreted by exocytosis.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.6
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• pp.823-828
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• 1998

The objective of this study is to investigate cryoprotective effects of corn starch enzyme hydrolysates of nonsweet and low-calories on denaturation of frozen fish protein. The cryoprotective effects of were examined in Alaska pollack actomyosin solution by changes in SDS-PAGE pattern, solubility, and $Ca^{2+}$-ATPase activity. When samples stored for 0 and 30 days were compared on SDS-PAGE patterns, severe changes in all bands were shown on the control sample regardless of storage temperature, especially in myosin heavy chain (MHC). Not much difference no appeared the electrophoretic pattern in case of the samples containing sucrose at any storage temperature during 30 days of storage. The cryoprotective effect of the hydrolysates were markedly dependant on storage temperature and no MHC band was found in the samples stored at $-5^{\circ}C$. The SDS-PAGE patterns of sample stored at $-20^{\circ}C$, however, completely maintained after 30 days or storage. When the samples were stored at $-5^{\circ}C$, the solubility of the sample containing sucrose was retained at $90\%$ after 30 days of storage, whereas dramatically decreased in other samples. The samples including sucrose, D.E. 10, 15, and 20 revealed $90\%$ in solubility when stored at $-20^{\circ}C$. The tendency of remaining $Ca^{2+}$-ATPase activity was almost shown the same as that of solubility.