• International Journal of Highway Engineering
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• v.14 no.5
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• pp.57-65
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• 2012

PURPOSES: It is important to consider the long-term performance of concrete pavement, because concrete pavement is more exposed to the various environmental conditions than any other concrete structures. One of the several methods to evaluate the long-term performance of concrete during winter is KS F 2456. Relative dynamic modulus of elasticity shows the resistance to freezing and thawing. METHODS: To measure relative dynamic modulus of elasticity, ultra sonic is generally used. But in this study, to measure the relative dynamic modulus of elasticity, both ultra sonic and shear wave were used and then compared each other. RESULTS: The results from the measurement by ultrasonic wave and shear wave were divided into three types. Type 1 : Specimens are good and relative dynamic modulus of elasticity did not decrease until 300 cycle. Type 2 : The relative dynamic modulus of elasticity decreased from the late cycle.(about 150 cycle later) Type 3 : The relative dynamic modulus of elasticity consistently decreased from the beginning. As a result of ANOVA, there is no difference according to measuring method, in type 2 and 3. But there is a difference according to measuring method, in type 1's relative dynamic modulus of elasticity. CONCLUSIONS: It is proved that shear wave can be used to understand the damage tendency of relative freezing and thawing and to measure the relative dynamic modulus of elasticity.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.10a
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• pp.268-270
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• 2007

We investigated characteristics of meat quality using by spectroscopic methods in visible region. Characteristics of beef muscle quality was measured by using spectrum analysis. We take the 3 samples of meat, and each sample has 3 measuring point. Also each measured samples has alternate thawing time(the state of frozen meat, thawing 20 minute and thawing 40 minute in the room temperature). As a results of experiments, measured intensity has changed by distributions of Myoglobin in meat muscles. And we can distinction the and characteristics of meat quality by distributions of lean meat and fat.

• Disaster Prevention Review
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• v.13 no.4
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• pp.158-159
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• 2011

• Disaster Prevention Review
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• v.15 no.2
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• pp.90-91
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• 2013

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.3
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• pp.313-316
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• 2000

Three Holstein steers, fitted with ruminal and duodenal cannulas, were used in a replicated $3{\times}3$ Latin square design to determine the digestibility of dietary nitrogen in total digestive tract by three methods, 1) mobile nylon bag (MNB); 2) total fecal collection (TFC); and 3) washed fecal sample after freezing and thawing through a sieve with a pore size of $45{\mu}m$ (WFS). A basal diet of oaten hay-barley was supplemented with one of the following protein sources; soybean meal, fish meal or blood meal. Steers were fed at a level of 2% of body weight. The experimental diets were contained approximately 1.85% nitrogen. There were no differences (p>0.05) among the diets on DM, NDF and nitrogen disappearances, and the diet results were pooled to assess the methods. Total tract disappearances of dry matter and neutral detergent fiber were 61.6, 71.1 and 78.9 and 25.3, 63.2 and 64.6 for MNB, TFC and WFS methods, respectively. The lower digestibility of DM and NDF in the MNB method could be a result of low ruminal incubation time. The TFC method had the lower (p<0.05) determination of nitrogen disappearance in the total digestive tract than the MNB and WFS methods. On the other hand, nitrogen disappearance in the total digestive tract determined by the WFS technique was comparable to that in MNB technique, as there was no significant difference (p>0.05) between the methods. It is shown that the disappearance of dietary nitrogen in the total digestive tract could be estimated in the intact animals by using washed fecal sample prior to freezing and thawing.

• Clinical and Experimental Reproductive Medicine
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• v.39 no.4
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• pp.153-160
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• 2012

Objective: The aim of this study was to compare vitrification optimization of mouse embryos using electron microscopy (EM) grid, cryotop, and thin plastic strip (TPS) containers by evaluating developmental competence and apoptosis rates. Methods: Mouse embryos were obtained from superovulated mice. Mouse cleavage-stage, expanded, hatching-stage, and hatched-stage embryos were cryopreserved in EM grid, cryotop, and TPS containers by vitrification in 15% ethylene glycol, 15% dimethylsulfoxide, 10 ${\mu}g/mL$ Ficoll, and 0.65 M sucrose, and 20% serum substitute supplement (SSS) with basal medium, respectively. For the three groups in which the embryos were thawed in the EM grid, cryotop, and TPS containers, the thawing solution consisted of 0.25 M sucrose, 0.125 M sucrose, and 20% SSS with basal medium, respectively. Rates of survival, re-expansion, reaching the hatched stage, and apoptosis after thawing were compared among the three groups. Results: Developmental competence after thawing of vitrified expanded and hatching-stage blastocysts using cryotop and TPS methods were significantly higher than survival using the EM grid (p<0.05). Also, apoptosis positive nuclei rates after thawing of vitrified expanded blastocysts using cryotop and TPS were significantly lower than when using the EM grid (p<0.05). Conclusion: The TPS vitrification method has the advantages of achieving a high developmental ability and effective preservation.

• Journal of the Korean Dietetic Association
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• v.13 no.4
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• pp.345-356
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• 2007

The purpose of this study was to investigate utilization and storage management practice of the frozen and refrigerated foods in school foodservice. 222 dietitians employed in school foodservice were surveyed. In school foodservice, the refrigerated stock farm products and seafoods (78.3%) were more used rather than frozen products (47.5%). According to school foodservice characteristics, the refrigerated meats including dairy products were more frequently used in elementary and middle schools than high school foodservice. On the other hand, the foodservice in high school used more frozen seafoods and processed foods than elementary school did. The data also showed a tendency for the contracted foodservice using more frozen meats and seafoods rather than refrigerated products when comparing with the self-operated foodservice. In terms of receiving conditions, storage methods and storage time, the result indicated that frozen or refrigerated products were often delivered at inappropriate temperature. Especially some products which were needed to be shipped and stored at refrigerated temperature such as mollusks, were delivered and kept at room temperature. The most frequently used thawing method were running water (56.9%), however, the frozen products were often sitted at room temperature for the purpose of thawing. According to the results, several inappropriate handling processes for frozen and refrigerated products were found in school foodservice. In order to improve handling process for frozen and refrigerated products, recognition of food handlers' weakness about storage and distribution, development of radical standards for receiving conditions, storage and thawing methods should be debated.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.621-624
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• 2008

Repair materials which applied to the concrete structures may have different quality characteristics depending on the environmental factors. Evaluation on durability of domestic repair materials have not yet secured enough quality performance on durability, mainly due to the lack of test methods resulted from various environmental factors. In this study, we carried out the tests on freezing and thawing resistance of domestic repair materials with different environmental factors applied under BS EN 13687, and analyzed the results by comparing with Korea's national test standards(KS F 4716). The results indicate that after the repetition of dry and wet conditions and the test on freezing and thawing with salt immersion resistance bond strength might show great difference depending on the type of repair materials and the size of sample. For securing better quality performance of repair materials, it is required to establish various standards on the test methods of freezing and thawing resistance with different environmental factors applied.

• Food Science and Preservation
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• v.19 no.2
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• pp.201-208
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• 2012

The sensory properties of $Kalopanax$ $pictus$ and $Cedrela$ $sinensis$ shoots were analyzed according to their blanching conditions and the thawing methods used. For the Hunter colors, the $K.$ $pictus$ that was blanched without adding salt for 6 min had the highest L value, and the $C.$ $sinensis$ that was blanched with 1% salt for 6 min had the highest L value. The chlorophyll content of $K.$ $pictus$ was 141.1 mg% when it was blanched for 3 min with 2% salt, and the chlorophyll content of $C.$ $sinensis$ that was blanched without adding salt for 6 min was highest (124.8 mg%). When $K.$ $pictus$ and $C.$ $sinensis$ were blanched without salt addition for 3 min, their texture showed a higher value than that of the other samples. The sensory test result showed the highest overall preference for the sample that was blanched without adding salt for 3 min, among all the samples. The L value of the $K.$ $pictus$ that was thawed in a microwave oven was significantly higher than that of the other samples, but the L value of the $C.$ $sinensis$ that was thawed at $4^{\circ}C$ was higher than that of the other samples. As for the overall preference for the samples according to the thawing method used, $K.$ $pictus$ and $C.$ $sinensis$ scored highest in the case of thawing in a microwave oven.

• Clinical and Experimental Reproductive Medicine
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• v.30 no.2
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• pp.127-133
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• 2003

Objective: The aim of this study was to investigate the morphological aspects of testicular tissue before and after freezing-thawing by light and transmission electron microscopy. Methods: Tissue biopsies were carried out on mouse testis for freezing. Samples in medium containing 20% glycerol were frozen by computer-controlled freezing program. The effect of freezing-thawing on the structural change of testicular tissues were examined by light and electron microscopy. Results: The freezing-thawing procedure had no significant effect on tubular diameter. However, it caused folding of the lamina propria, and notable damage to Sertoli cells, spermatogonia and spermatocytes. The cells were detached, desquamated from the basal lamina and had increased vacuolization. Round spermatids, elongated spermatids and spermatozoa were less affected, and most of them maintained their normal structure. Conclusions: The structure of spermatogonia, spermatocyte and basal compartments in seminiferous epithelium was significantly altered by freezing-thawing procedure of mouse testicular tissues. Thus, we need to develop a more reliable method for the cryopreservation of testicular tissues.