• International Journal of Highway Engineering
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• v.13 no.1
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• pp.21-32
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• 2011

The frost penetration depth of pavement is usually estimated from the freezing index that made temperature data analysis of 30 years and decided the thickness of anti-frost layer. The field monitoring region in study was divided into five regions by freezing index 550~650$^{\circ}C{\cdot}$day, 450~550$^{\circ}C{\cdot}$day and 350~450$^{\circ}C{\cdot}$day. Each region has three-section of road pavement such as cutting area, boundary area of cutting and banking, and lower area of banking. The field monitoring system was established both in the section of anti-frost layer and in the section without anti-frost layer. The data analysis was conducted for determination of frost penetration depth within the paved road by the field monitoring system. The result showed that The temperature of subgrade without anti-frost layer shows below zero in centigrade for the region of freezing index 550~650$^{\circ}C{\cdot}$day, up and down around zero degree in subgrade for the region of freezing index 450~550$^{\circ}C{\cdot}$day, and there is no place existed below zero degree in subgrade for the region of freezing index below 450$^{\circ}C{\cdot}$day. With comparison of field frost penetration depth for the cross-sections of pavement, the cutting area shows the greatest frost penetration depth, and less influence of frost penetration depth for the boundary area of cutting and banking, and the least influenced for the lower area of banking.

• Journal of the Korean Society of Food Science and Nutrition
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• v.21 no.2
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• pp.207-212
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• 1992

To analyze the freezing phenomena of foodstuffs, the numerical freezing model with 3 steps was established. When water and 2% agar gel were used as samples, Neumann's solution was well matched with experimental results by the numerical model. However, in the case of 20% gelatin gel and pork meat, Weiner's solution was better than Neumann's solution. This numerical freezing model was proved to be good model to describe the freezing phenomena with phase change in the point of versatility and precision.

• Magazine of the Korea Concrete Institute
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• v.10 no.4
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• pp.205-212
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• 1998

Frost damage of a storage tank for chemical admixtures caused by a low temperature in winter and quality deterioration of chemical admixtures have been often reported. However, there have been few regulations and researches related to the frost damage of chemical admixtures and facilities. Therefore, this paper is intend to investigate not only, the freezing points of chemical admixtures such as AE admixtures and water-reducing AE admixtures, etc., but also the quality variation of concrete used with chemical admixtures before freezing and after freeze-thaw cycles. According to the results of experiments, most chemical admixtures except anti-freezing agent and accelerating water-reducing AE admixtures should be kept from being frozen in low winter temperatures. However, full agitation of frozen chemical admixtures dose not cause the problems of concrete related to the quality of chemical admixtures.

• Journal of the Korea Concrete Institute
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• v.15 no.1
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• pp.43-51
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• 2003

Recently, to consider financial and constructive aspect usage of Admixture such as Blast-Furnace Slag and Fly-Ash, are increased. Also the use of cold-weather-concrete is increased. Blast-Furnace Slag, a by-product of steel industry, have many advantage to reduce the heat of hydration, increase in ultimate strength and etc. But it also reduces early-age strength, so it is prevented from using of Blast-Furnace Slag at cold-weather-concrete. In this study, for the purpose of increasing usage of Blast-Furnace Slag at cold-weather-concrete, it is investigated the strength properties of concrete subjected to frost damage for the cause of early age curing. The factors of this experience to give early frost damaged were Freezing temperature(-1, -10, $-15^{\circ}C$), Early curing age(0, 12, 24, 48hour), Freezing times(0, 12, 24, 48hour). According to this study, if early curing is carried out before haying frost damage, the strength of concrete used admixture, subjected to frost damage, is recovered. And that properties are considered, the effect of using admixture like blast-furnace-slag, is very high

• International Journal of Highway Engineering
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• v.11 no.4
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• pp.143-152
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• 2009

The purpose of this study is to evaluate the freezing index and frost penetration depth. The freezing index and frost penetration depth were analyzed using air temperature and temperature profile of pavement system in Korea LTPP-SPS(Long Term Pavement Performance-Specific Pavement Study) site. The predicted frost penetration depth were then compared with the measured one from the LTPP sites. And the trend of annual freezing index was analyzed using the temperature data of meteorological stations located in the vicinity of Korea LTPP-SPS site. The result showed that the freezing index was rapidly decreased since 1987, and it was known that the use of freezing index determined from the past 30 years temperature data could cause the over estimates in the pavement thickness design. The temperature profile measured at 3 sections of LTPP-SPS sites showed that the temperature of subbase layer was above $0^{\circ}C$, even though anti-frost layers were found in these sections. Comparing the measured and calculated frost depth, the frost depth calculated from the subgrade frost penetration permissible method showed a similar trend with the measured frost depth.

• Journal of the Korean Geotechnical Society
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• v.29 no.1
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• pp.81-92
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• 2013

This paper presents the results of a numerical investigation into the behavior of retaining wall subject to cycles of freezing and thawing due to seasonal temperature change. The thermo-hydro-mechanical coupled finite element modeling strategy was first established to simulate the wall behavior. A series of finite element analyses were then performed on a range of conditions representing seasonal temperature change characteristics. The results indicated that the average freezing temperature and the number of cycles of freezing and thawing were the primary influencing factors for the wall behavior. Also revealed was that the duration of freezing period does not significantly affect the wall displacement and the lateral earth pressure, and that the earth pressure on the wall does not significantly change due to the freezing and thawing action suggesting that the increase in the wall displacement during the freezing and thawing action may be attributed to degradation of backfill due to the freezing and thawing action.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.10
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• pp.1550-1557
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• 2015

This study was conducted to evaluate the improvement effects of bitter taste of doraji (Platycodon grandiflorum) with different freezing temperature conditions ($-5^{\circ}C$, $-10^{\circ}C$, $-20^{\circ}C$, and $-70^{\circ}C$). After freezing for 4 h, frozen doraji was thawed and dehydrated. Doraji frozen at $-20^{\circ}C$ showed higher contents of crude fat, crude protein, crude ash, crude fiber, and nitrogen free extract. Moisture, crude saponin, and total polyphenol contents of doraji frozen at $-5^{\circ}C$ were higher than in other samples. Weight loss of doraji was significantly different as freezing temperature decreased and the process repeated. Doraji frozen at $-5^{\circ}C$ showed higher contents of saponin and phenol than the control. Hardness of doraji increased as freezing temperature decreased. According to the preference test, Doraji frozen at $-5^{\circ}C$ showed higher preference and less bitter taste intensity than other samples. These results mean that doraji frozen at $-5^{\circ}C$ with less bitter taste could be utilized widely as a food material.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.12 no.3
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• pp.131-136
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• 1979

Histological changes of yellow sea bream, Branchiostegus japonicus japonicus, were observed under microscope during freezing storage for 6 months at $65^{\circ}C$ and $-35^{\circ}C$, and the results were compared with the muscle structure of fresh muscle. The freezing storage of yellow sea bream at $-^{\circ}C$ showed more changes in muscle structure than that stored at $-35^{\circ}C$. In the view point of the changes of the muscle structure, the yellow sea bream can be stored up to 1 month at $65^{\circ}C$ and 3 months at $-35^{\circ}C$. The freezing of yellow sea bream at $-5^{\circ}C$ showed higher extracellular freezing than that at $-35^{\circ}C$.

• Journal of Embryo Transfer
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• v.18 no.1
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• pp.51-59
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• 2003

This study was carried out to evaluate the effect of different freezing and thawing rates on the viability, motility and acrosomal changes of frozen canine spermatozoa. The ejaculated semen was extended with Tris-egg yolk buffer containing 8% glycerol and equilibrated for 60 min after cooled to 4$^{\circ}C$ for 58 min. The straws were cryopreserved gradually by slow-cooling at different distance(6, 10 and 17 cm, respectively) from the liquid nitrogen (L$N_2$) to achieve temperature rate of 3, 8.9 and 19$^{\circ}C$ /min. Thawing of the straws was performed in a water bath fur 2 min at 37$^{\circ}C$ and 55$^{\circ}C$ , respectively. The motility of frozen-thawed spermatozoa was assessed by phase-contrast microscopy. To assess their viability and acrosome content, spermatozoa were stained with a vital stain and Fluorescence conjugated lectin Pisum Savitum Agglutinin (FITC/PAS), respectively. Concentration of the ejaculated fresh semen was normal range of 3.44 $\times$ 10$^{8}$ /ml. Freezing temperature were reduced to -110, -70 and -35$^{\circ}C$, as higher distance from liquid nitrogen, 6, 10 and 17 cm, respectively. Freezing at 3$^{\circ}C$/min in distance of 17 cm from liquid nitrogen yielded better motility, viability and rate of intact acrosome than 8.9 or 19$^{\circ}C$/min and the optimal thawing was 37$^{\circ}C$ for 2 min.

• Journal of the Korean GEO-environmental Society
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• v.12 no.12
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• pp.79-88
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• 2011

Adfreeze bond strength develops upon freezing of pore water within soil and at foundation surface. It has been reported that various factors like temperature, soil type, and pile surface roughness affect adfreeze bond strength. Especially, pile surface roughness has been considered as a primary factor to design pile foundation in frozen ground. It has usually been estimated with fixed correction factors for pile materials. However, even if the pile foundation material is the same, the surface roughness could vary depending on the production circumstances. In this study, laboratory test was carried out to quantitatively analyze the effects of surface roughness on the adfreeze bond strength, and fractal dimension was used as a measure for surface roughness. Test results showed that adfreeze bond strength increased with decreasing temperature, increasing vertical stress and surface roughness. The adfreeze bond strength varies sensitively with surface roughness in the early freezing section of $-2^{\circ}C$, but its sensitivity decreased in the temperature ranging between $-2^{\circ}C$ to $-5^{\circ}C$. The results conclude that the roughness highly affects the frictional resistance of pile surface in frozen ground; however, the roughness does not affect considerably when the temperature drops below about $-2^{\circ}C$.