• Food Science of Animal Resources
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• v.40 no.3
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• pp.444-460
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• 2020

This study was conducted to investigate the effects of freezing and storage temperature (-18℃, -50℃, and -60℃) on the physicochemical properties of pork neck and chicken leg meat in home-scale deep freezers. Pork neck was cut into a thickness of 3 cm (9×9×3 cm, 150 g), individually packed in air-containing packages, and stored at different temperature (-18℃, -50℃, and -60℃) for 6 months. Chicken leg meats were prepared (10 cm long, weighing 70 g) and packed in the same manner. Frozen samples were thawed at 2℃. Physicochemical properties such as thawing loss, cooking loss, water-holding capacity, color, volatile basic nitrogen (VBN), and thiobarbituric acid reactive substances (TBARS) were evaluated. The samples frozen by deep freezing (-60℃) was favorable with respect to thawing loss, color, and VBN. Samples frozen at -60℃ had lower values of thawing loss and VBN than those frozen at -18℃ for all storage periods (p<0.05). Color parameters were more similar to those of fresh meat than to those of samples frozen at -18℃ for 6 months. The TBARS of all samples were below 0.3 mg malondialdehyde/kg, thereby indicating oxidative stability of lipids. Consequently, deep freezing at -60℃ may be acceptable for maintaining the quality of fresh pork neck and chicken leg meat for 6 months without deterioration.

• Journal of Aquaculture
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• v.17 no.1
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• pp.8-11
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• 2004

Milt of the catfish was stripped into immobilizing solution containing 175 mM NaCl and 30 mM Tris at pH 7.8 and was successfully cryopreserved after a stepwise freezing procedure. After stepwise thawing, motility of spermatozoa was slightly lower than that of fresh sperm. Batches of 40-80 eggs were fertilized with cryopreserved spermatozoa, after thawing and activation in solution containing 50 mM NaCl, 20 mM Tris and HCl at pH 7.8; this resulted in 62.2% fertilization success, compared to 70.6 % with fresh sperm.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2003.11a
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• pp.63-67
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• 2003

There are many factors that generate the early deterioration of the concrete structure. As the one of the representative factors, we can think an invasion of the water, air and so on. The water and air invade in inside void along the capillarity and they become the cause that the durability like corrosion of layer department due to freezing and thawing, inside steel frame corrosion, and so on blacks. Therefore with covering permeability covering waterproofing material of fluid condition in outer wall, intercepting the deterioration factor due to the infiltration of water from outside and for salt damage of concrete layer department, freezing damage and neutralization, it needs, to improve durability of structure. This study separately examined physical and chemical specific of quality liguid siliceous of waterproofing material. Therefore as this applys the construction site, it improves the durability of concrete structure. Further this presents the application plan from the construction market against the new material.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2003.05a
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• pp.63-67
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• 2003

There are many factors that generate the early deterioration of the concrete structure. As the one of the representative factors, we can think an invasion of the water, air and so on. The water and air invade in inside void along the capillarity and they become the cause that the durability like corrosion of layer department due to freezing and thawing, inside steel frame corrosion, and so on blacks. Therefore with covering permeability covering waterproofing material of fluid condition in outer wall, intercepting the deterioration factor due to the infiltration of water from outside and for salt damage of concrete layer department, freezing damage and neutralization, it needs to improve durability of structure. This study separately examined physical and chemical specific of quality liquid siliceous of waterproofing material. Therefore as this applys the construction site, it improves the durability of concrete structure. Further this presents the application plan from the construction market against the new material.

• Geomechanics and Engineering
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• v.29 no.3
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• pp.349-357
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• 2022

Abnormal climate events are occurring frequently around the world. In particular, cold waves and heavy snow lead to damage and deterioration of facilities, which can cause loss of life or property damage, such as shortening the lifespan of facilities. Therefore, it is very important to prepare an appropriate maintenance system and to establish a strategy to cope with abnormal weather conditions. In this study, laboratory freezing experiments were performed to analyze the freeze-thaw characteristics affecting the tunnel concrete lining, and heat flow analysis was carried out based on the test results. Based on these experimental and theoretical analysis results, quantitative freeze-thaw evaluation criteria for tunnel concrete linings were proposed.

• Journal of Ceramic Processing Research
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• v.21 no.2
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• pp.164-169
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• 2020

This experimental study investigated the durability degradation of concrete exposed to freezing and thawing and chloride intrusion. In order to observe the degree of the degradation, 24 MPa, 35 MPa and 60 MPa concretes were used with 4% and 12% calcium chloride solution as freezing water for scaling resistance and freeze - thaw resistance tests. The results show that 24 MPa and 35 MPa concrete had a relatively large decrease in durability due to the freeze-thaw resistance and scaling resistance, but the 60 MPa concrete was not deteriorated significantly. In addition, when the concentration of the solution of calcium chloride was 4%, the degradation of durability was most remarkable. The results of this study suggest when concrete structures such as bridges or roads expose to the environmental conditions, appropriate measures such as increasing the designed standard strength of concrete need to be deliberated and additional studies should be conducted.

• Proceedings of the KSR Conference
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• 2002.05a
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• pp.264-270
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• 2002

The frost heaving pressure can be a problem for weakening of the railroadbed material. In this study, upon freezing a saturated soil in a closed-system from the top, a considerable pressure was developed. This pressure is induced as a result of a curved ice-water interface. This study was initiated to investigate the soils frost heaving expansion pressure and physical characteristics resulting from freezing and freezing-thawing cycle process. Weathered granite soils, sandy soil were used in the laboratory freezing test subjected to thermal gradients under closed-systems.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.8 no.2
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• pp.107-117
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• 1975

Alaska pollack caught in the Northern Pacific Ocean and frozen aboard vessel are skipped to the plant and processed into frozen fillets. In the present paper quality changes during thwaing, refreezing and storage at $-20^{\circ}C$ are discussed. Natural, running-water, vacuum and steam thawing were employed as thawing methods. And contact plate, air blast, immersion in dry ice-alcohol solution freezing and storage at $-5^{\circ}C$ were applied to refreeze the thawed fillets. As quality factors content of drip released, salt-extractable protein, VBN, DNA in the drip and pH were determined. In addition, bacteriological tests were also carried out along with the whole process. In thawing of round material, the vacuum thawing was more effective than any other method, resulting in drip, salt-extractable protein $(N\%)$, VBN and DNA as $4.4\%,\;1.82\%,\;16.21mg\%$ and $13.70\;{\mu}g/ml$, respectively. Storage at $-5^{\circ}C$ as refreezing method yielded lower in drip and DNA content but similar to or slightly higher in both salt-extractable protein and VBN, which might postulate that the quality of the frozen fillet depends not largely on the secondary freezing but on the conditions of thawing and primary freezing. It seemed that most of the bacterial flora in thawed fillet came from skin and viscera of fish, worker's hands, utensils and other processing facilities, since sanitary indicative bacteria were not detected in the frozen flesh of round Alaska pollack. Bacterial quality of fillet varied with thawing methods, vacuum thawing appeared more sanitative compared with other methods as natural, running-water, and steam thawing. Bacterial colonies isolated from the thawed fillet were composed of $73.8\%$ Gram negative rod shape, $4.9\%$ Gram positive rod shape, $18.0\%$ cocci, and $3.3\%$ yeast. Decreasing rate of coliform group of the fillet during the storage at $-20^{\circ}C$ for 30 days was more than $70\%$ and that of plate count was less than of coliform group.

• Clinical and Experimental Reproductive Medicine
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• v.28 no.3
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• pp.191-198
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• 2001

Objective : This study was conducted to examine the effect of vitrification on the survival and in vitro development of mice 1-cell zygotes. Method: Effects of exposure to vitrification solution and vitrification, with different concentrations of the cryoprotectant solution, were examined. The 1-cell zygotes were also subjected to a slow freezing-thawing method to compare with vitrification method. Solution composed of ethylene glycol (6.0 M, 5.0 M, 4.0 M) and sucrose (1.0 M) were used as cryopropectant. The experiments employed the method loading the embryos on electron microscope grids. Results: I. The effects of exposure in vitrification solution. 1-cell zygotes were non-toxic at all concentrations of the vitrification solution showing the survival rate between 88.1% and 97.5%. Development into 2-cell was more successful in the higher concentrations of the vitrification solution. Therefore, higher concentrations of the vitirification solution do not seem to cause any problems in vitrification procedure. II. The effects of vitrification method. 1-cell zygotes showed the survival rate between 78.8% and 92.4%. The lowest and the highest survival rate was observed in the 6.0 M and 4.0 M vitrification solution, respectively. 2-cell development rates varied from 77.6% to 91.3%. Blastocyst development rate was shown highest in 5.0 M and the lowest in 4.0 M solution. Therefore, the highest 2-cell and blastocyst development rate was observed in 5.0 M solution. III. Comparison of vitrification and slow freezing-thawing method on 1-cell zygotes. This experiment showed that 1-cell zygotes had the highest survival and development rates in 5.0 M vitrification solution. Vitrified group of 1-cell zygotes, in the 5.0 M vitrification solution, were compared with the group processed in slow freezing-thawing method. The development rate into 2-cell and blastocyst as well as the survival rate were higher in the vitrified group than in the slowly freezed group. Conclusion: 1. The results demonstrate that the best cryoprotectant is a 5.0 M vitrification solution for 1-cell zygotes. 2. Vitrification method significantly increases the survival rate of the 1-cell zygote and its development into 2-cell and blastocyst. Equilibration and exposure time during the vitrification was remarkerbly short in this experiment. Total time, from the exposure to vitirification solution to storage in the liquid nitrogen, was taken only 90 seconds. In contrast, the slow freezing-thawing method have taken more than four hours. Taken together, we presume that the overall time used for the procedure contributes to the results as an important parameter. 3. The loading of 1-cell zygotes on the EM grid is technically more simple and takes less time than the straw or cryo vial method.

• Journal of the Korea Concrete Institute
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• v.17 no.3 s.87
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• pp.455-464
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• 2005

Today the application of antiwashout underwater concrete to the construction sites is increasing steadily, while its reliability is in issue. Particularly, antiwashout underwater concrete is known to have very weak durability on frost attack, and hence Japan society of civil engineers(JSCE) regulated that not to use of antiwashout underwater concrete where the freezing and thawing is suspected. This study aims the improvement of the freezing and thawing resistance for antiwashout underwater concrete. From the results of fundamental test, FA20 and SG50 showed good performance in fluidity and long term compressive strength than control concrete. Meanwhile, MK10 marked the highest compressive strength through the whole curing age but a defect on fluidity was discovered. The results from the repeated freezing and thawing test show that the large volumes of air entrapped by cellulose based antiwashout underwater admixture gave bad effects to frost durability and hence not much benefits were confirmed from the use of mineral admixtures. However there were some increasing effects on frost durability of MK10 and SG50 by securing $6{\pm}0.5\%$ of entraining air. In the meantime, there was a increasing tendency of frost durability by increasing blame's fineness of ground granulated blast furnace slag.