• Reproductive and Developmental Biology
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• 제34권1호
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• pp.41-46
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• 2010

The objective of this study was to evaluated the efficiency of sperm cryosurvival using each extenders Triladyl and LEY containing egg yolk to the cryopreservation of separated sperm by percoll in miniature pig. The ejaculated semen from miniature pig was separated by 65% percoll and un-separated sperm as a control before freezing. The freezing of diluted semen added with Triladyl containing egg yolk and LEY solution (solution I: 11% Lactose or Triladyl + egg yolk; solution II: solution I + glycerol + OEP). Analysis of sperm ability was estimated by viability, capacitation acrosome reaction using chlortetracycline (CIC) the morphologic abnormality and hypoosmotic swelling test(HOST). The groups were designed that as separated sperm by Percoll with Triladyl(ST) or LEY(SL) for cryopreservation. And unseparated sperm with Triladyl(UT) or LEY(UL). As a results, the viability was higher significantly(p<0.05) in ST, SL, UT than UL extender. The morphologic abnormality was measured significantly (p<0.05) lower in ST than other extenders. The AR-patterned in CTC analysis was measured significantly(p<0.05) lower in SL and UL than other extenders. In conclusion, using Triladyl extender resulted in viability and morphology of separated sperm by percoll that were effective than using LEY extender, but it resulted in capacitation acrosome reaction was lower than using LEY extender.

• Fisheries and Aquatic Sciences
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• 제24권2호
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• pp.63-77
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• 2021

The aim of this research was to investigate different factors, including cryoprotective agents (CPAs), diluents, dilution ratios, equilibrium times, freezing rates, and thawing methods to optimize cryopreservation protocols for large yellow croaker (Larimichthys crocea). The parameters evaluated were sperm motility, sperm activity index (SAI), survival rate, and DNA damage. Different types of CPAs, such as dimethyl sulfoxide (DMSO), propylene glycol (PG), ethylene glycol (EG), methanol, and glycerol, were tested for sperm preservation. The highest motility, SAI, and survival rate were observed when EG was used. Different diluents such as Stein's solution, Hank's balanced salt solution, marine fish Ringer's solution, artificial seminal plasma (ASP) of small yellow croaker, and Cortland solution were investigated. The highest post-thaw motility was observed upon using ASP as the diluent. Different concentrations of EG were then mixed with ASP to identify the optimal EG concentration. Experimental results showed that the motility (70.33 ± 1.20%), SAI (5), and survival rate (78.30 ± 0.42%) of post-thaw sperm were optimum when 10% EG and ASP were used as the CPA and diluent of cryopreservation, respectively. Post-thaw sperm motility was high at equilibration times below 150 s and at an optimum dilution ratio of 1:1 (sperm: CPA + diluent) and was not significantly different compared with fresh sperm motility. The freezing rate was found to be slow below -10℃/min. The thawing temperature of 45℃ was identified as ideal. The percentage of tail DNA in post-thaw sperm at 10% EG and ASP was also investigated and was found to have more significant DNA damage than that in fresh sperm but significantly lower damage than that in post-thaw sperm at EG concentrations of 5%, 15%, and 20% (p < 0.05). The cryopreservation protocols obtained in this study will be useful in large yellow croaker hatcheries.

• 한국가축번식학회지
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• 제22권1호
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• pp.1-9
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• 1998

본 연구는 체외에서 성숙된 소 미수정란을 electron microscope grid와 동해제인 EFS30을 이용하여 초급속 동결하였을 때 정상적인 배 발달의 유도 가능성 여부를 조사하고 동해제 및 동결방법의 유해성 여부를 indirect immunocytochemistry방법으로 확인하고자 실시하였다. 동해제는 30% ethylene glycol, 0.5 M sucrose, 18% ficoll과 10% FBS가 들어 있는 PBS로 된 EFS30을 사용하였다. 본 연구에서 얻어진 결과는 다음과 같다. 동해제와 동결과정이 난자의 microtubule, microfilament 및 chromatin의 형태에 미치는 영향을 indirect immunocytochemistry방법으로 조사하였던 바, 동해제 노출 뿐 아니라 동결에 의해서도 대조군과 차이를 나타내지 않았다. 초급속 동결이 소 미수정란의 체외수정에 미치는 영향을 검토했을 때, 총 정자침투율(96.7%, 90.0%), 정상 자응전핵 형성율(74.6%, 68.9%)과 난자당 정자수(1.50, 1.44)가 동결군과 대조군에 있어서 차이는 볼 수 없었다. 또한, 초급속 동결-융해 후의 체외발달능을 조사했던 경우, 85.5%의 높은 난자 생존율과 74.5%의 난할율, 그리고 31.4%의 배반포 형성율을 얻었다. 이러한 결과는 난자의 생존율을 제외한 수정율과 배반포 형성율에 있어서 대조군(76.0%, 34.6%)과 노출군(77.9%, 33.0%)의 결과와 매우 유사한 것이었다. 이와 더불어, 각 처리군에서 얻어진 배반포기배를 Hoechst 염색방법으로 총세포수를 조사하였을 때도 그 차이는 확인할 수 없었다. 따라서 체외에서 성숙된 소 미수정란은 EM grid와 EFS30 동결액을 이용한 초급속 동결방법으로 동결하였을 때 정상적인 배발달을 유도할 수 있다는 것을 알 수 있었다.(收量)은 양공시두부(兩供試頭部) 모두 괴근장(塊根長)과 정(正)의 상관(相關)이, 분기수(分岐數)와는 부(負)의 상관(相關)이있었다.(發芽率)이 98.1%이던 것이 68.8%로 감소(減少)하였다. 3. 온도변화(溫度變化)에 따른 수수의 발아소요일수(發芽所要日數)는 12일(日)($15/10^{\circ}C$), 6일(日)($25/20^{\circ}C$) 및 3일(日)($40/35^{\circ}C$)로 온도(溫度)가 상승(上昇)함에 따라 비례적(比例的)으로 단축(短縮)되었다. 옥수수 수는 16일(日), 7일(日) 및 3일(日)이 소요(所要)되었다.量)은 $24.6{\sim}36.7%$로서 건엽중(乾葉中)의 함량(含量)보다 월등히 높았고 조단백질함량(粗蛋白質含量)은 $2.0{\sim}5.3%$로서 건엽중(乾葉中)의 함량(含量)보다 현저히 낮았다. 특(特)히 P.931의 건경중(乾莖中)의 조섬유함량(粗纖維含量)은 다른 작물(作物)에 비해 현저(顯著)히 높은 편이었다.적차이(量的差異)를 나타냈다.間)에는 부(負)(-)의 상관(相關)이 있다.($P{\leq}0.01%$). 5. NEL 및 starch value 환경온도(環境溫度)가 상승(上昇)됨에 따라 감소(減少)된다. 4 엽기(葉期) sorghum식물(植物)의 환경온도(環境溫度)를 달리 하였을 때 NEL가치(價値)는 각각(各各) 4.87MJ($30/25^{\circ}C$), 5.46MJ($25/20^{\circ}C$) 및 5.81MJ/kg($18/8^{\circ}C$)로 변(變)하여 고온(高溫)에서 net energy lactation 축적(蓄積)이 크게 감소(減少)되었다.다. 그러나 기온(氣溫)이 낮은 조건(條件)

• 한국과학교육학회지
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• 제25권2호
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• pp.88-97
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• 2005

이 연구에서는 어는점 내림에 대한 과학교과서의 설명 방식과 과학 교사들의 개념을 조사하였다. 분석한 교과서는 7차 교육과정에 근거하여 개발된 중학교 2학년 과학교과서 7종과 고등학교 화학 II 교과서 5종이었다. 교사들의 개념은 설문지를 통해 얻었으며, 연구 대상 교사의 수는 146명이었다. 교과서의 설명 유형은 '현상을 묘사' 하는 것과 '증기압 내림으로 설명' 하는 유형으로 구분하였다. 대부분의 중학교 교과서와 고등학교 교과서에서는 현상을 묘사하는 수준으로 어는점 내림을 설명하였으며, 이러한 현상이 일어나는 이유에 대한 설명은 없었다. 또한 어는점 내림을 설명하는 그래프의 내용도 교과서마다 달랐다. 교사들 역시 어는점 내림에 대해 제대로 이해하지 못하는 것으로 나타났다. 용질의 방해로 어는점 내림 현상을 이해하는 교사들도 많았다. 그러나 끓는점 오름 현상을 설명할 때 도입되는 이러한 개념이 어는점 내림에서는 어떻게 관련되는지 명확하게 설명하지 못하였다. 이 연구에서는 어는점 내림 현상을 설명하기 위하여 엔트로피의 개념을 도입할 필요성에 대해 주장하였다.

• 설비공학논문집
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• 제13권12호
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• pp.1175-1183
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• 2001

Recently, a great attention has been paid to the ice thermal storage system for the purpose of energy saving and reduction in peak electrical demand. In the present study, it has been investigated the freezing behavior of several kinds of water solutions with nonionic surfactant. In order to prevent ice blockage in a cooled pipe, the amount and wall adhesion behavior of ice of the test fluids were observed experimentally under different concentration of water solution with surfactant, temperature of cooled wall, and the shear velocity of test fluids. The results showed that the size of ice crystal became smaller at higher shear velocity at wall. And the lowest limit of wall adhesion of ice in water solution with surfactant was found at 230 W/$m^2$ of heat flux.

• Fisheries and Aquatic Sciences
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• 제18권4호
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• pp.417-420
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• 2015

We investigated the relationship between viability and IGF-1 receptor (IGF-1R) activity in D-shaped and umbo larvae of the surf clam Spisula sachalinensis after treatment with vitrification solution (VS) or freezing. In a toxicity assay, VS1, containing 5 M dimethyl sulfoxide (DMSO), was very harmful to D-shaped and umbo larvae. However, VS2, containing 5 M ethylene glycol (EG), was not harmful to either larval stage. Although VS2 had a promising toxicity test outcome, none of the larvae survived vitrification. After immersion into VSs and freezing, IGF-1R ${\beta}$-subunits were detected in all larvae; however, tyrosine phosphorylation of intracellular ${\beta}$-subunits was detected only in the control and live groups. These results suggest that activation of IGF-1R may influence surf clam larvae viability.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2003년도 학술.기술논문발표회
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• pp.13.2-17
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• 2003

When fresh concrete is exposed to low temperature, the concrete may suffer frost damage due to freezing at early ages and strength development may be delayed. One of the solution methods to resolve these problems is to lower freezing temperature of concrete by the use of chemical admixture called Accelerators for Freeze Protection. In this study, it was the results of appling cold weather concrete using Accelerator for Freeze Protection in the Daewoo Trump world field. Before the application of the cold weather concrete using accelerator for freeze protection, we executed the some test in the laboratory and mock-up test in the field. We examined the manifestation of compressive strength complying with the amount of Accelerators for Freeze Protection and curing conditions, and then made a selection of most suitable amount of Accelerators for Freeze Protection.

• 설비공학논문집
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• 제17권2호
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• pp.183-190
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• 2005

In the process of ice-slurry making, ice adhesion on cooling wall or in narrow flow Path disturbs continuous ice formation. In this study, the effect on the ice adhesion to cooling surface by some freezing experiments was investigated, quantitatively. Three types of solutions were frozen in various coating vessels with stirring. In the experiment, the ice adhesion between cooling wall and Ice-slurry was evaluated by measuring stirring power. From the result, the stirring power of slurry mixture in PTFE-coating vessel was smaller than those in PE-coating, PFA-coating and bare SUS vessel. Especially, in EG H PG 1.S/ HD 1.5 mass$\%$ solution, the stirring power in the PE-coating vessel was smaller than that in the PFA-coating or SUS vessel.

• 설비공학논문집
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• 제18권6호
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• pp.477-485
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• 2006

A study on frost prevention of fin-tube heat exchanger is experimently performed by spreading antifreezing solution on heat exchanger surface. It is desirable that the antifreezing solution spreads completely on the surface forming thin liquid film to prevent frost nucleation and crystal growth and to reduce the thermal resistance across the liquid film. A small amount of antifreezing solution falls in drops on heat exchanger surface using two types of supplying devices, and a porous layer coating technique is adopted to enhance the wettedness of antifreezing solution on the surface. It is observed that the antifreezing solution liquid film prevents fin-tube heat exchanger from frosting, and heat transfer performance does not degrade through the frosting tests. The concentration of supplied antifreezing solution can be determined by heat transfer analysis of the first row of heat exchanger to avoid antifreezing solution freezing due to dilution by moisture absorption.

• 콘크리트학회논문집
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• 제19권5호
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• pp.647-653
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• 2007

레디믹스트콘크리트 공장에서 동절기에 고분자 화학 혼화제, 특히 조기강도 확보를 위해 개발된 액상형 조강제를 사용할 경우, 해당 혼화제의 저장 안정성을 검토할 필요가 있다. 본 연구에서는 액상형 조강제의 동결 및 겔화 특성을 검토하고, 이를 방지할 수 있는 재료적, 설비적 해결 방안을 제시하여, 실무 적용시의 품질관리 방안으로 제시하고자 하였다. 검토 결과, 액상형 조강제의 동결온도는 $-11.8^{\circ}C$ 정도로 확인되어 콘크리트의 강도 발현 온도한계보다 낮은 온도 범위로서 안정적인 것을 확인하였으며, $SiO_2$와 $Na_2O$의 mol비를 0.31 수준으로 디자인한 sodium silicate를 $37{\pm}0.5%$ 포함시켜 제조함에 따라 저온에서의 겔화를 최소화하는 한편, 이의 저장 및 공급을 위해 고안된 설비 시설은 공급탱크의 온도를 $40^{\circ}C$ 정도로 설정하여 설비 전단계의 온도 분포가 실무 활용상 문제가 없음을 확인할 수 있었다.