• 한국식품저장유통학회지
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• 제16권3호
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• pp.362-370
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• 2009

오존수로 살균처리한 반건조홍고추를 -10, -20 및 $-40^{\circ}C$ 로 각각 냉동하여 $-18^{\circ}C$로 냉동저장하면서 품질변화를 살펴보았다. 드립손실은 처리구가 대조구에 비해 많았으나, 처리구간에서는 저장기간에 따른 유의적 차이를 보이지 않았으며, 저장일수가 길어질수록 두 시료간의 차이가 감소하는 경향을 보였고, 냉동온도에 의해 유의적인 차이를 보였다. 텍스처는 처리구에서 저장 3개월 이후부터 저장기간 별 유의적 차이가 나타나지 않았다. a값은 냉동 전 반분반건조 처리구가 대조구에 비해 유의적으로 높은 값을 나타내었으며, 냉동저장 3개월 후부터는 두 시료 모두 유의성있는 차이를 나타내지 않았다. Capsaicinoids 함량은 저장일수가 길어질수록 유의적으로 감소하는 경향을 나타내었으며, 냉동온도에 영향을 받는 것으로 판단되었다. Carotenoids 함량은 냉동온도와 저장온도에 영향을 받지 않았으며, 반분 반건조처리구는 3개월 이후부터 carotenoids 함량의 변화가 없는 것으로 나타났다. Ascorbic acid 함량은 반건조처리 후 약 47%의 손실을 보였고. 유리당은 약 6.5% 손실되었다. 관능검사 결과 색깔과 외관에서도 대조구와 반분 반건조 처리구간의 유의적 차이가 없게 나타났다.

• 한국가축번식학회지
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• 제26권2호
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• pp.119-124
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• 2002

본 연구는 돼지에서 동결정액을 이용한 번식능력을 개선하기 위한 동결정액 포장재료의 효과를 구명하기 위하여 실시하였다. 본 시험에는 축산기술연구소 종축개량부 (충남, 성환)의 인공수정센터에서 사육중인 종모돈이 사용되었다. 기존의 돼지 동결정액 포장방법인 maxi-straw 동결정액 포장방법과 5$m\ell$빈 cryogenic-vial 및 aluminum-pack 포장방법을 비교한 결과 cryogenic-vial로 포장하여 액체질소 상단 15cm에서 동결한 후 52$^{\circ}C$ water bath에서 190초 융해한 방법이 기존의 maxi-straw 방법과 비슷한 결과를 나타내었다. Cyogenic-vial 포장방법의 동결-응해 방법을 설정하기 위하여 융해시간을 달리하여 시험한 결과 액체질소 상단 15cm에서 동결하고 52$^{\circ}C$에서 190초 간 융해하였을 때 정자운동성이 120초 및 150초 응해시 보다 우수하였다 (P<0.05). 그러나 정상첨체비율은 응해시간 간에 차이가 없었다. 52$^{\circ}C$에서 45초간 응해 한 maxi-straw 포장방법과 52$^{\circ}C$에서 190초 융해한 cryogenic-vial 포장방법간에 정액성상을 비교한 결과 총정자운동성과 정자의 빠르기는 maxi-straw가 우수하였다 (P<0.05). 그러나 직진성과 정상첨체비율은 두 포장방법간에 차이가 없었다. 동결정액 포장방법별 인공수정시 번식성적은 maxi-straw 동결정액이 cryogenic-vial 동결정 액보다 수태율, 분만율, 그리고 산자수가 높았으나 통계적 유의차는 인정되지 않았다. 이상의 결과를 종합해 보면 cryogenic-vial 포장 방법의 동결 및 음해방법을 좀 더 연구개발하면 기존의 maxi-straw포장방법을 대체하여 실용화 할 수 있을 것으로 사료된다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2003년도 가을 학술발표회 논문집
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• pp.54-57
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• 2003

Scaling deterioration of port concrete structures due to the combined effects of chemical actions by seawater and the freeze-thaw action is also a problem which has not yet been fundamentally solved. Furthermore, deterioration of concrete surface was considered as accelerate factor of concrete durability tended to decrease. Therefore, we considered the scaling measuring method and decreasing influence of durability of concrete according to kind of binders, such as OPC, Slag, Slag+Fa, due to freeze and haw of sea water. As a results of this study, it was effective method of scaling deterioration of concrete, and confirmed the salt deterioration resistance effect to use slag binder against to sea water.

• 한국재료학회지
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• 제26권6호
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• pp.320-324
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• 2016

Porous SiC beads were prepared by freeze-drying a polycarbosilane (PCS) emulsion. The water-in-oil (w/o) emulsion, which was composed of water, PCS dissolved p-xylene, and sodium xylenesulfonate (SXS) as an emulsifier, was frozen by dropping it onto a liquid $N_2$ bath; this process resulted in 1~2 mm sized beads. Beads were cured at $200^{\circ}C$ for 1 h in air and heat-treated at $800^{\circ}C$ and $1400^{\circ}C$ for 1 h in an Ar gas flow. Two types of pores, lamella-shaped and spherical pores, were observed. Lamellar-shaped pores were found to develop during the freezing of the xylene solvent. Water droplets in the w/o emulsion were changed into spherical pores under freeze-drying. At $1400^{\circ}C$ of heat-treatment, porous SiC was synthesized with a low level of impurities.

• Asian-Australasian Journal of Animal Sciences
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• 제24권2호
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• pp.181-189
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• 2011

Cryopreservation protocols induce partially irreversible damage to mammalian sperm plasma membranes. Previous studies have indicated that adding cholesterol to the plasma membrane, as cholesterol-loaded-cyclodextrins, improves cryosurvival of sperm. Therefore, the purpose of this study was to determine if treating sperm of Markhoz bucks with cholesterol-loaded-cyclodextrins (CLC) (0, 0.75, 1.5, 2.25 and 3 mg/ml diluted $240{\times}10^6$ sperm/ml) in Tris-citric acid-glucose diluents with and without egg yolk (containing 5% glycerol) would improve the post-thaw sperm quality. The motion characteristics were evaluated with a Computer Assisted System Analyzer (CASA); acrosome integrity and vitality were measured with the triple-stain technique. Samples were recovered before and after freezing by means of putting straws into $37^{\circ}C$ water for 30 sec and then parameters were assessed. The results showed that the treatments significantly affected motility, progressive motility, recovery rate, curvilinear velocity, beat cross frequency, live sperm with reacted acrosome, live sperm with unreacted acrosome, dead sperm with reacted acrosorne, and dead sperm with unreacted acrosome during freezing (p<0.05). However; no significant differences were found for average path velocity, straight line velocity, amplitude of lateral head displacement, straightness and linearity (p>0.05). The best results were observed for extender containing 2.25 mg/ml ($240{\times}10^6$ sperm/ml) CLC supplemented with 2.6% egg yolk. In conclusion, the findings of this study indicate improved Markhoz sperm viability and motility following treatment in the presence of egg yolk.

• Clinical and Experimental Reproductive Medicine
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• 제51권3호
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• pp.213-224
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• 2024

Objective: Some age-related testicular changes, such as Sertoli cell vacuolization and blood-testis barrier breakdown, reduce total sperm production and male fertility. Therefore, this study investigated the effect of vitamin E on restoring testicular function in aged mice. Sperm cryo-resistance was also assessed. Methods: Twenty-eight 48-week-old male Naval Medical Research Institute mice were divided into four groups for a daily gavage of vitamin E: the control group received distilled water, while the three treatment groups were administered 100, 200, and 400 mg/kg, respectively, for 4 weeks. Subsequently, semen analyses, DNA fragmentation index (DFI), and protamine deficiency tests were conducted. Testicular histology, tissue antioxidant enzyme activity, and gene expression levels were also assessed. Results: The two higher dosages of vitamin E were associated with a higher sperm count, greater progressive motility, and improved sperm morphology (p<0.05). These benefits were also evident after sperm freezing (p<0.05). Although chromatin abnormalities increased following vitrification, the treatment groups showed better outcomes (p<0.05). The tubular diameter, epithelium height, and luminal diameters remained unchanged with age. The tissue antioxidant capacity was greater in the groups receiving the high doses of vitamin E. Additionally, significant increases in inhibitor of DNA binding protein-4 (Id4) and GDNF family receptor alpha-1 (Gfra1) expression were observed in the higher vitamin E dosage groups, and promyelocytic leukemia zinc finger protein (Plzf) expression was notably present in the 400 mg/kg treatment group compared to the control group (p<0.05). Conclusion: Antioxidant supplementation might enhance reproductive outcomes in aging males. The observed effects included improved sperm cryo-resistance, which is advantageous for future applications such as sperm freezing or fertility preservation.

• 한국도로학회논문집
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• 제18권1호
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• pp.63-72
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• 2016

PURPOSES : The use of roller-compacted concrete pavement (RCCP) is an environmentally friendly method of construction that utilizes the aggregate interlock effect by means of a hydration reaction and roller compacting, demonstrating a superb structural performance with a relatively small unit water content and unit cement content. However, even if an excellent structural performance was secured through a previous study, the verification research on the environmental load and long-term durability was conducted under unsatisfactory conditions. In order to secure longterm durability, the construction of an appropriate internal air-void structure is required. In this study, a method of improving the long-term durability of RCCP will be suggested by analyzing the internal air-void structure and relevant durability of roller-compacted concrete. METHODS : The method of improving the long-term durability involves measurements of the air content, air voids, and air-spacing factor in RCCP that experiences a change in terms of the kind of air-entraining agent and chemical admixture proportions. This test should be conducted on the basis of test criteria such as ASTM C 457, 672, and KS F 2456. RESULTS : Freezing, thawing, and scaling resistance tests of roller compacted concrete without a chemical admixture showed that it was weak. However, as a result of conducting air entraining (AE) with an AE agent, a large amount of air was distributed with a range of 2~3%, and an air void spacing factor ranging from 200 to $300{\mu}m$ (close to $250{\mu}m$) coming from PCA was secured. Accordingly, the freezing and thawing resistance was improved, with a relative dynamic elastic modulus of more than 80%, and the scaling resistance was improved under the appropriate AE agent content rate. CONCLUSIONS : The long-term durability of RCCP has a direct relationship with the air-void spacing factor, and it can be secured only by ensuring the air void spacing factor through air entraining with the inclusion of an AE agent.

• 한국지반환경공학회 논문집
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• 제20권1호
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• pp.67-74
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• 2019

동상은 동토지역에서 발생하는 대표적인 공학적 특성이다. 계절동토(seasonal frost area)에 해당하는 우리나라는 동결융해에 의한 구조적 피해가 발생하고 동상에 관한 연구의 필요성이 증대되고 있는 실정이다. 본 논문에서는 새롭게 개발한 투명 온도제어형 셀을 활용하여 동상에 관한 연구를 수행하였다. 동상에 민감한 흙을 인공적으로 조성하여 동상민감성 판정에 있어 중요한 인자 중 하나인 물 주입속도(water intake rate)에 관한 분석을 실시하였다. 간극수 동결에 의한 부피팽창(heave by pore water)이 수렴하는 시점 이후에 동상속도(frost heave rate)와 물 주입속도는 거의 유사하게 나타났다. 그러나 물 주입속도를 측정하기 위해 상부 페더스탈에 설치한 O-ring은 몰드 내벽과의 마찰을 발생시켜 동상발생을 저하시켰다. 따라서 물 주입속도를 활용한 동상민감성 판정 기준은 신뢰하기 힘들다고 판단되었으며, 유사한 거동을 보이는 동상속도를 활용하는 것이 적절하다는 결론을 내렸다. 또한, 동상민감성 흙을 활용해 시료크기가 동상에 미치는 영향을 파악하고자 하였다. 시료크기가 다른 2가지 경우에 대해 동상시험을 수행하였으며 상재하중, 온도구배, 그리고 건조단위중량을 동일하게 설정하였다. 실험결과를 토대로 시료크기는 동상에 영향을 미치지 않는다는 것을 발견하였다.

• 한국수정란이식학회지
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• 제17권2호
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• pp.91-100
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• 2002

The experiment was divided into two phases. In phase-I fresh embryos were transferred and in Phase-II frozen embryos were transferred. Embryos were collected by using Dulbecco's phosphate buffered saline. In phase-I total of 65 ova were collected out of 107 ovulation in 18 goats. Recovery of ova was 60.74％, of which 51 (78.46％) was fertilized. Sixteen embryos were transferred to 10 recipient goats and kidding was observed in 6 goats, that produced 10 kids. Thus, 62.50％ embryo survival and 60％ kidding were achieved in phase-I. In phase-II of the experiment, 17 regular cyclic Black Bengal goats were used. The main purpose was to study the viability of caprine embryos after cryopreservation. In this phase the embryos were collected and frozen using Bio-cool freezers. A two step addition of cryoprotectants (5％ glycerol and 10％ glycerol) and three-step dilution of cryoprotectants with 1mole (M) sucrose was used. Embryos were preserved for 10 to 45 days. Out of 27 embryos preserved, 18 were recovered after freezing and thawing (37$^{\circ}C$ water bath) with 33.33％ embryonic loss. Seventeen frozen and thawed embryos were transferred in 9 recipient goats, out of which kidding was observed in 6 goats and 7 kids were produced, giving a 66.66％ kidding and embryo survival of 41.17％. The technique utilized for fresh and frozen embryo transfer can be successfully utilized to produce goats of superior genetic merits. The protocol used for addition of cryoprotectant, freezing, thawing and dilution was found suitable for caprine embryo freezing.

• 콘크리트학회논문집
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• 제12권3호
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• pp.11-19
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• 2000

It has been reported that few manufacturers of cement mortar for precast products use chemical and mineral admixture due to the absense of restrictions related to the application of admixture and the poor manufacturing facilities. Therefore, this paper is intended to contribute to the improvement of quality by investigating the properties of cement mortar for precast products using fly ash, blast furnace slag and AE water reducing agent. According to the test results. it was found that the cement mortar products using fly ash and AE water-reducing agent had better qualities than those of ordinary portland cement.