• Geomechanics and Engineering
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• 제19권2호
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• pp.193-199
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• 2019

A frozen fringe plays a key role in frost heave development in soils. Previous studies have focused on the physical and mechanical properties of the frozen fringe, such as overall hydraulic conductivity, water content and pore pressure. It has been proposed that the thickness of the frozen fringe controls frost heave behavior, but this effect has not been thoroughly evaluated. This study used a temperature-controllable cell to investigate the impact of frozen fringe thickness on the characteristics of frost heave. A series of laboratory tests was performed with various temperature boundary conditions and specimen heights, revealing that: (1) the amount and rate of development of frost heave are dependent on the frozen fringe thickness; (2) the thicker the frozen fringe, the thinner the resulting ice lens; and (3) care must be taken when using the frost heave ratio to characterize frost heave and evaluate frost susceptibility because the frost heave ratio is not a normalized factor but a specimen height-dependent factor.

• 한국식품영양학회지
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• 제21권4호
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• pp.510-517
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• 2008

Effects of addition of Chinese chives into frozen noodle on retrogradation of the cooked frozen noodle were examined by enzymatic evaluation during the storage 3 days at $4^{\circ}C$. The retrogradation rate during storage was significantly reduced by addition Chinese chives. Thus we hypothesized that retarogardation and textural changes of frozen noodle might be linked to thermostable amylase in Chinese chives. The amylase isolated from Chinese chives was affected by temperature and pH of buffer used. The enzyme was mainly extracted 20 mM potassium phosphate buffer(pH 7.0). The enzyme was extremly stable at wide temerature and pH. Amylase activity was maximal at $50^{\circ}C$ and pH 7.5. The enzyme was not inactivated by heat treatment at $70^{\circ}C$, $80^{\circ}C$ for 30 min. We suggest the enzyme was stable at high temperature. To investigate the effect of different storage packge on texture properties, color, sensory evaluation, parent-packged and unparent packaged frozen noodle was compared with control. As the storage passed, the frozen noodle packaged with parent showed a rapid decrease in the color. The hardness was gradually decreased during storage. It was found that unparent packged must be nessasry in the Chinese chives frozen noodle. In changes of sensory properties by traind panel, Chinese chives frozen noodle with 2% blanched Chinese chives got the highest score in overall acceptability, therefore we tried acceptance test by consumers with 2% blanched frozen Chinese chives noodle.

• 한국수정란이식학회지
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• 제6권2호
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• pp.47-51
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• 1991

This study investigated full-term development potential of ultrarap idly frozen and thawed mouse 2-cell embryos. Mouse 2-cell embryos, dehydrated by exposure to freezing medium, were directly immersed into liquid nitrogen and thawed in 37$^{\circ}C$ water. The embryos that were frozen and thawed were cultured in uitro and transferred to foster mothers to examine there developmental potential. As a result, the frozen-thawed 2-cell embryos developed to blastocysts in vitro as a similar rate as control 2-cell embryos did(in vitro 2-cell, 86.4%; in vivo 2-cell, 90.9%; solution control, 89.9%; control, 89.7%). Normal live young were obtained from transfer of frozen-thawed embryos to the oviduct and uterus of pseudopregnant recipients (3l.4~56.7%).

• Clinical and Experimental Reproductive Medicine
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• 제20권2호
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• pp.165-176
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• 1993

These studies were carried out to investigate the optimal freezing protocol for 2 cell mouse embryos and to find the probability of quality control with 2-cell embryos frozen. The embryos showed the best survival by the protocol composed of a freezing solution with the cryoprotectants(1.5M propanediol + 0.1M sucrose), and a 2-steop thawing method(room temperature, 20 sec-37$^{\circ}C$, 20 sec). The developmental ability of frozen-thaw 2-cell embryos did not differ from that of fresh 2-cell embryos in m-KRB medium with 0.4% bovine serum albumin. But development of frozen-thaw embryos was depended on the supplements of the medium. In the albumin-free medium, the developmental rate(rate of blastocysts) was significantly reduced, compared with that in the medium with 0.4% BSA. Also, when frozen-thaw embryos were cultured in the meduim with human fetal cord serum(HCS), the developmental rate of frozen-thaw embryos was sligtly reduced, compared with that of fresh 2-cell embryos. Finally, frozen-thaw 2-cell mouse embryos were more sensitive to the toxic agent of disposable-plastic syringe. Therefore, toxicity of medium could be effectively detected by frozen-thaw 2-cell mouse embryos.

• 한국식품과학회지
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• 제20권4호
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• pp.536-540
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• 1988

Blanching시간, chemical dipping, 냉동방법 및 저장기간이 냉동양송이의 texture, 색깔 및 수율에 미치는 영향을 연구한 결과는 다음과 같다. Whole mushroom의 경우 5분간 blanching한 것은 1-2분간 blanching한 것 보다 shear press값이 현저히 높았으며, 저장기간이 연장됨에 따라 shear press값이 매우 유의성 있게 증가했다. 그러나 냉동방법은 texture에 유의성 있는 영향을 주지 않았다. Sliced mushroom의 경우 blanching시간이 길어짐에 따라 shear press 값이 증가하기는 하나 유의성은 없었으며, 저장기간이 연장됨에 따라 texture가 현저히 tough 해짐을 알 수 있었다. 그리고 시료의 texture를 관능적으로 측정한 결과는 대체적으로 shear press 결과와 유사한 경향을 보였다. Chemical dipping 방법은 blanching 시간을 짧게하여 냉동양송이의 수율을 높히면서 저장중 색깔의 변화를 방지하는데 효과적이었으며, 특히 whole mushroom의 수율은 상당히 증진시킬 수 있었다. Sliced mushroom의 경우는 blanching time을 2분이하로 단축시키면 rotary slicer로 절단작업을 할 때 조직이 부스러져 생기는 중량손실이 증가하므로 2분 또는 그 이상의 blanching time이 필요했다.

• Geomechanics and Engineering
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• 제36권2호
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• pp.145-156
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• 2024

The mechanical properties of the concrete-frozen soil interface play a significant role in the stability and service performance of construction projects in cold regions. Current research mainly focuses on the precast concrete-frozen soil interface, with limited consideration for the more realistic cast-in-place concrete-frozen soil interface. The two construction methods result in completely different contact surface morphologies and exhibit significant differences in mechanical properties. Therefore, this study selects silty clay as the research object and conducts direct shear tests on the concrete-frozen soil interface under conditions of initial water content ranging from 12% to 24%, normal stress from 50 kPa to 300 kPa, and freezing temperature of -3℃. The results indicate that (1) both interface shear stress-displacement curves can be divided into three stages: rapid growth of shear stress, softening of shear stress after peak, and residual stability; (2) the peak strength of both interfaces increases initially and then decreases with an increase in water content, while residual strength is relatively less affected by water content; (3) peak strength and residual strength are linearly positively correlated with normal stress, and the strength of ice bonding is less affected by normal stress; (4) the mechanical properties of the cast-in-place concrete-frozen soil interface are significantly better than those of the precast concrete-frozen soil interface. However, when the water content is high, the former's mechanical performance deteriorates much more than the latter, leading to severe strength loss. Therefore, in practical engineering, cast-in-place concrete construction is preferred in cases of higher negative temperatures and lower water content, while precast concrete construction is considered in cases of lower negative temperatures and higher water content. This study provides reference for the construction of frozen soil-structure interface in cold regions and basic data support for improving the stability and service performance of cold region engineering.

• Food Science and Biotechnology
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• 제15권2호
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• pp.173-176
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• 2006

The effect of enzymatically hydrolyzed vital wheat gluten (EHG) on dough mixing and the baking quality of wheat flour frozen dough was examined. Three different proteases, pepsin, trypsin, and chymotrypsin, were tested individually, sequentially paired, or in combination of all three enzymes. Addition of 1% EHG produced no observable effect on the mixing properties of wheat flour dough. However, addition of 2.5% pepsin-hydrolyzed gluten decreased the mixing tolerance of the wheat flour, and 1% trypsin-hydrolyzed gluten increased the loaf volume of both frozen and non-frozen dough. This finding suggests that trypsin-hydrolyzed vital wheat gluten may serve as a baking additive in replacement for $KBrO_3$ to improve frozen dough quality.

• 한국수정란이식학회지
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• 제12권1호
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• pp.67-74
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• 1997

This study was carried out to increase the viability of bovine frozen4hawed in vitro produced (IVP) embryos and pregnancy rate by direct transfer method. Cumulus-oocyte complexes were aspirated from excised Hanwoo ovaries and matured in TGM 199 for 20~22 hours at 38.5$^{\circ}C$ in 2% $CO_2$ in air. Matured oocytes were fertilized with capacitated sperm for 6 hours and then co-cultured with cumulus cells for 9 days. 63% of the oocytes cultured was deaved and 29% out of them developed into blastocysts. Good or excellent grade of blastocysts on D 7 or 8 were frozen with 1.8M ethylene glycol as a cryoprotectant for direct transfer. Frozen embryos were thawed at 2$0^{\circ}C$ water for 10 sec following 4~5 second in air. For the survival assay of frozen4hawed lVP blastocysts, they were cultured in TCM 199 supplemented with 100$\mu$M $\beta$-mercaptoethanol and 20% FCS for 72 hours. The percentage of embryos developed to re-expanded or hatched after 72 hours culture was 95. 5 and 77.3%, respectively. When frozen-thawed Ivp embryos were transferred to 43 synchronized recipients by direct transfer method, eighteen recipients (41.8%) was pregnant. The highest pregnant was in naturafly synchronized recipients (71.4%), but induced estrus by using PRID(29.2%) and PGF$_2$$\alpha$(20.0%) was showed lower pregnancy rate. The pregnancy rate was higher in day 7 blastocysts(56.0%) than day 8 blastocysts(22.2%). (Key words: in vitro produced, blastocyst, frozen-thawed, direct transfer)

• 혜화의학회지
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• 제15권2호
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• pp.1-7
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• 2006

Objectives : Comparison acupuncture treatment with Acupuncture & Moxibustion combined treatment for frozen shoulder 20 case patients Methods : Efficacy evaluation using Apley scratch test(ROM), Martin.A.N'Improvement rate Results : 1. Acupuncture & Moxibustion combined treatment group were better than acupuncture treatment group in Martin.A.N' Improvement rate. 2. Acupuncture & Moxibustion combined treatment group were better than acupuncture treatment group in Apley scratch test(ROM). but this study need to many case frozen shoulder investigation.

• 한국수정란이식학회지
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• 제23권3호
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• pp.161-166
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• 2008

The techniques for the collection, cooling and freezing of semen and artificial insemination of horses are not fully understood in Korea. We investigated the percentages of total motile (TM) and progressively motile (PM) sperms after the collection, cooling and freezing of stallion semen. The average volume of semen was 167 ml in Thoroughbred and 68 ml in Arab. The average numbers of spermatozoa in Thoroughbred and Arab were $104\times10^6/ml$ and $86\times10^6/ml$ respectively. The average percentages of TM and PM were 82.3% and 88.6% in Thoroughbred, and 61.4% and 82.6% in Arab, respectively. The average percentage of TM at 4 hr after cooling at $5^{\circ}C$ was significantly lower than that at 0 hr ($30.0\pm4.1%\;vs.\;78.0\pm2.5%,\;p<0.05$), but the percentage of PM was similar between 66.5 and 73.2% at 0, 1, and 4hr. The average percentage of frozen-thawed Thoroughbred semen frozen in MFR5 extender was 56.2%, which was significantly higher than that of the semen frozen in LE extender (average 32.9%, p<0.05). The percentage of TM in Arab was similar for semen frozen in MFR5 extender and LE extender (18.2% and 21.2%, respectively), but the percentage of PM was significantly higher in sperm frozen in MFR5 extender than in sperm frozen in LE extender (69.0% vs. 36.4%, p<0.05). Four mares were artificially inseminated by Thoroughbred frozen-thawed semen and one of them fertilized at 11 day after artificial insemination. In this study, the collection, cooling and freezing of equine semen were possible under domestic conditions.