• Title/Summary/Keyword: Freezing Method

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Study on Stability Analysis of Rock Slope Under Freezing-Thawing Cycle (동결융해작용을 받는 암반사면의 안정성해석에 관한 연구)

  • Baek, Yong
    • Proceedings of the Korean Geotechical Society Conference
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    • 2000.11a
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    • pp.543-550
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    • 2000
  • Rock slopes along the road or railroad are affected by temperature and therefore experienced iterative freezing-thawing process between winter and early spring. The purpose of this study is to analyze the stability of rock slopes which are influenced by the deterioration due to the freezing-thawing. The analysis is the homogenization method which evaluates the strength property of discontinuous rock mass, and as a strength failure criterion, Drucker-Prager failure criterion is used. The deterioration property of real rock is obtained by a freezing-thawing laboratory test of tuff and this property of deterioration is quantitated and used as a basic data of stability analysis for rock mass. To evaluate the deterioration depth due to the freezing-thawing in situ rock slope, one dimensional heat conductivity equation is used and as the result I can find that the depth of which is affected by a temperature. After the freezing-thawing depth of model slope is determined, we analyze the pattern of rock mass stength value of rock slope model which excesses the limit of self-load.

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Evaluation of Frost Heave Prediction and Frost Susceptibility in Sample using JGS Test Method (일본 동상성판정기준을 적용한 시료의 동상예측 및 동상성 평가)

  • Kim, Young-Chin;Hong, Seung-Seo
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.03a
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    • pp.926-931
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    • 2008
  • This paper show two different standardized test methods(Japanese Geotechnical Society; JGS 2003). One test is a "Test Method for Frost Heave Prediction Test, JGS 0171-2003", and the other test is a "Test Method for Frost Susceptibility, JGS 0172-2003". The purpose of this test is to obtain the freezing rate(freezing speed), frost heave ratio(heave to sample height), frost heave rate(heaving speed), and other parameters to be used for frost heave prediction and determine the frost susceptibility by freezing test with water intake. This method shall be used to predict the frost heave in frozen ground and evaluate the frost susceptibility of natural and replacement materials.

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Experimental Study of Frozen Barrier Using Artificial Ground Freezing System (인공지반동결 시스템을 이용한 동결차수벽의 실험적 연구)

  • Shin, Eun-Chul;Kang, Hee-Myeong;Park, Jeong-Jun;Kim, Sung-Hwan
    • Journal of the Korean Geosynthetics Society
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    • v.8 no.3
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    • pp.35-44
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    • 2009
  • The purpose of this study was to prevent spreading of contaminants from movement of underground water by creating a barrier using artificial freezing method on a soil contaminated by oils and various NAPLs. Specimens with 80% and 90% degrees of saturation were prepared to form freezing barrier using artificial freezing method. With increasing freezing time of freezing barrier, barrier was formed faster in the specimen with 90% degree of saturation by about an hour compared to the specimen with 80% degree of saturation. In addition, thinnest thickness of frozen barrier in both specimens was 50mm after 12 hours of freezing time, showing expansion of freezing area with time. The results of this study can be applied to barrier in waste reclamation sites and contaminated regions or to flow control of contaminants.

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Extraction of Road Surface Freezing Section using GIS (GIS를 이용한 도로의 노면결빙구간 추출)

  • Choi, Byoung-Gil;Kim, Joong-Sik
    • Journal of Korean Society for Geospatial Information Science
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    • v.13 no.4 s.34
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    • pp.19-25
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    • 2005
  • This study suggests a method for securing road safety by extracting the expected surface freezing section in planning a route using GIS. When planning a road construction in a mountainous area it is possible to confront surface freezing especially in the wintertime. In addition, it is required assessment data of surface freezing rates in the case of turnkey inspections of newly constructed or expanded roads. Consequently, an analysis method that can quantitatively estimate the surface freezing section and sunshine influence on each section of a road is needed. We can extract the expected surface freezing section which amounted to around 29km of the Donghae highway, with such techniques as three-dimensional modeling, sunshine simulation geographical database construction and spatial analysis using the overlay function of the GIS spatial analysis. This study can be used as a method to assess advance safety which has a direct influence on planning the blueprint that should be approved by a policy maker after efficiently understanding the expected surface freezing section in accordance with hill shade.

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Effect of seeding on post-thaw motility and viability of canine frozen sperm (견정액 동결시 seeding처리가 융해후 정자의 활력 및 생존률에 미치는 효과)

  • 김종호;이필돈;유일정;김용준
    • Korean Journal of Veterinary Service
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    • v.18 no.3
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    • pp.1-12
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    • 1995
  • To investigate effect of seeding on post-thaw motility and viability of canine spermatozoa, the semen from male dogs which had been proved to be fertile in the past were frozen and seeded during freezing process. Post-thaw motility and viability of canine sperm which were frozen and seeded were investigated according to different seeding temperatures of $-5^{\circ}C$, $-10^{\circ}C$, or $-l5^{\circ}C$ and also according to different concentration of glycerol of 2%, 5% and 10%. In addition, post-thaw motility of canine sperm frozen by direct freezing in a deep freezer or programmed freezing in a programmed cell freezer was investigated. Post-thaw motility of canine sperm was compared according to different seeding temperatures : The sperm seeded at $-5^{\circ}C$ showed considerably higher post-thaw motility than that of non-seeding, and that seeded at $-10^{\circ}C$, or $-l5^{\circ}C$, respectively, in 2% and 5% glycerol groups on both 2 and 7day after freezing(p<0.05). In 10% concentration of glycerol, the sperm seeded at each seeding temperature showed considerably higher post-thaw motility than that of non-seeding group on day 7 after freezing(p<0.01). Post-thaw viability of canine sperm was compared according to different seeding temperatures : The sperm seeded at $-5^{\circ}$ showed significantly higher post-thaw motility than that of non-seeding, and that seeded at $-10^{\circ}C$, or $-l5^{\circ}C$, in 5% and 10% glycerol groups on day 7 after freezing(p< 0.05). In comparison of post-thaw motility of canine sperm seeded according to different concentration of glycerol, 5% glycerol group and 10% glycerol group showed considerably higher post-thaw motility than 2% glycerol group without difference between those two groups in all seeding temperatures($-5^{\circ}C$, $-10^{\circ}C$ and $-l5^{\circ}C$) on day 2 and 7 after freezing(p<0.01). In comparison of post-thaw viability of canine sperm seeded according to different concentration of glycerol, 5% glycerol group and 10% glycerol group showed the same considerably higher post-thaw viability than 2% glycerol group on each thawing day(p<0.01). The canine sperm frozen and seeded by programmed freezing method showed considerably higher post-thaw motility than that frozen by direct freezing method in all different seeding temperatures($-5^{\circ}C$, $-10^{\circ}C$ and $-l5^{\circ}$). These results indicated that the higher post-thaw motility and viability was obtained in the spermatozoa seeded than that of non-seeding, that among different seeding temperatures of $-5^{\circ}C$, $-10^{\circ}C$ and $-l5^{\circ}C$, the sperm seeded at $-5^{\circ}C$ showed higher post-thaw motility and viability than the other temperatures, also among different concentrations fof glycerol of 2%, 5% and 10%, the sperm frozen and seeded in 5% and 10% concentration of glycerol showed higher post-thaw motility and viability than that in 2% of glycerol, and that the sperm frozen and seeded by programmed freezing method showed higher motility than that by direct freezing method.

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A Study on the Processing Aptitude and Storage of Common-European Squid(Loigo vulgaris) 2. The Skin Stripping, Freezing and Thawing Conditions (유럽화살오징어의정장성 및 가공적성에 관한연구 2. 탈피 동결 및 해동조건)

  • 박희열;허종화
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.19 no.2
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    • pp.175-179
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    • 1990
  • Investigations of skin stripping freezing and thawing conditions of common-European squid (Loigo vulgaris) were carried out. The most effective method of skin stripping was to immerse the sample at 5$0^{\circ}C$ for 10-15 minutes in fresh water or salt solution(5-10% w/v) Contact freezing and fresh water thawing method was found to be effective. The muscle structure of the sample thawed after contact freezing was almost the sample after contact freezing was almost the same as that of raw sample.

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Ultrarapid Freezing of DNA-Injected and Nuclear-transplanted Mouse Embryos (외래유전자 주입 및 핵치환된 생쥐 수정란의 초급속 동결)

  • 강만종;한용만;이철상;김선정;유대열;신상태;이경광
    • Korean Journal of Animal Reproduction
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    • v.17 no.3
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    • pp.201-207
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    • 1993
  • We determined whether the ultrarapid freezing method is applicable to micromanipulated mouse embryos. One-cell mouse embryos were microinjected with MThGH gene. Nuclei from one-cell embryos of F1(C57BL$\times$CBA) mice were transplanted into enucleated one-cell embryos of ICR mice. The injected and nucleated embryos that developed to 2-cell stage were cryopreserved by ultrarapidfreezing. The embryos equilibrated in freezing medium(3 M DMSO+0.25 M sucrose+2% FBS in PBS) were directly immersed into liquid nitrogen and then thawed in 37$^{\circ}C$ water. Development rates of the microinjected and nuclear-transplanted embryos to blastocyst stage after ultrarapidly freezing and thawing were 31% and 55%, respectively. The frozen-thawed embryos were transferred to pseudopregnant recipient, which then gave birth to 17 offsprings. Twelve(14% of the transferred embryos) and five(20%) offsprings were derived from microinjected and nuclear-transplanted embryos, respectively. The results indicate that the DNA injected and nuclear-transplanted mouse embryos are cryopreservable at 2-cell stage by ultrarapid freezing method.

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A Simple Method for Testing Freezing Resistance Based on Chlorophyll Fluorescence in Tea (Camellia sinensis L.)

  • Chun, Jong-Un;Jeong, In-Ho;Choi, Hyoung-Kog
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.45 no.5
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    • pp.322-327
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    • 2000
  • For the stable production of high quality tea, the freezing resistance is a very important character. Most of the farmers have planted out-pollinated seeds that are not genetically pure. So, with small sample, a quick and simple method is required to test freezing resistance of lots of germ-plasm and early generation of hybrids. The absorbances(A530 nm) of TTC reduction solution at -5$^{\circ}C$ were positively correlated with resistance to photoinhibition of PSII in 6 hour photoinhibitory treatments, being significantly fitted by simple linear regression ($R^2$=${0.64}^{**}$). Chlorophyll fluorescence measured by Fv/Fm was found to be very useful in evaluating the relative levels of freezing resistance in tea.

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Measurement of Size Distributions of Submicron Electrosprays Using a Freezing Method and an Image Processing Technique (냉각법 및 영상 처리기법을 이용한 서브마이크론 정전분무 액적의 크기분포 측정)

  • Ku, Bon-Ki;Kim, Sang-Soo;Kim, Yu-Dong
    • Proceedings of the KSME Conference
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    • 2001.06e
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    • pp.100-106
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    • 2001
  • The size distributions of electrospray droplets from the Taylor cone in cone-jet mode are directly measured by using a freezing method and a transmission electron microscope (TEM) image processing technique. These results are compared with the data obtained by an aerodynamic size spectrometer (TSI Aerosizer DSP). The use of glycerol seeded with NaI and a freezing method make it possible to sample droplets with their original sizes preserved. Since pictures of droplets are taken with TEM with very low vapor pressure of the solution, evaporation is suppressed by freezing. For liquid flow rates below 1 nl/sec, the measured droplet diameters by the TEM image processing technique and the aerosizer are in the range of 0.25 to $0.32{\mu}m$ and 0.30 to $0.40{\mu}m$, respectively. Comparing the TEM data with the aerosizer measurements, it has been revealed that the TEM image processing technique can afford more accurate values of droplet size distributions in the submicron range of 0.1 to $0.4{\mu}m$.

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Ultrarapid Freezing of Mouse Ova (생쥐난자의 초급속동결)

  • 박영식;서태광;이택후;전상식
    • Journal of Embryo Transfer
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    • v.10 no.3
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    • pp.203-208
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    • 1995
  • This study was carried out to efficiently use the ultrarapid freezing method in the cryopreservation of mouse ova. For this, the effects of dehydration method, oval vigour and $0^{\circ}C$ controlling method on post-thawing viability were investigated. Fresh mouse ova were dehydrated in mPBS with 3.5M DMSO and /or 0.25M sucrose, and directly immersed in L$N_2$ for ultrarapidly freezing. The frozen ova were thawed at 37$^{\circ}C$, rehydrated in mPBS with 0.25M sucrose, and then repeatedly washed in HAM's Fl0 before evaluating the morphological normality of frozen-thawed ova. The results obtained showed that there was difference between treatments in a experiment. 1) The post-thawing viability of ova dehydrated in multi-step (48.4$\pm$13.8%) was higher than that of ova in two-step (40.9$\pm$14.0%). 2) The post-thawing viability of fertilized ova (87$\pm$14.0%) was significantly(p<0.0l) higher than that of unfertilized ova (5.4$\pm$5.4%). 3) The post-thawing viability of ova dehydrated and rehydrated using a cooling machine (95.8$\pm$4.2%) was significantly(p<0.05) higher than that on ice(84.1$\pm$9.9). In conclusion, in order to efficiently cryopreserve ova in vitro with ultrarapidly freezing method, highly viable embryos should be selected, heavy osmotic shock to the dehydrating ova should be avoided, and embryos in high osmotic condition were dehydrated and rehydrated in a constantly low temperature.

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