본 연구는 기존 선박에 자외선 (UV) 평형수처리장치(BWMS)를 설치 한 경우, 수치 계산을 통해 평형수 처리시간의 증가를 정량적으로 조사하였다. 계산 결과 배수량 55,000톤 가스 운반선의 평형수 처리시간은 UV BWMS 미설치 및 유량 제어 기능 없이 2.152 시간이었다. 평형수 처리시간은 UV BWMS 설치 후 14.2 % 증가했으며, 유량 제어 기능까지 고려 시 20.4 % 증가했습니다. 실제 조건들을 고려하면 UV BWMS 설치 후 평형수 처리시간은 기존 평형수처리시간 대비 최소 30 % 정도 증가할 것으로 예상됩니다. 따라서 업계 관계자는 평형수 처리시간 증가로 인한 선박 운영 손실을 최소화하기 위하여 UV BWMS 선정시 본선의 실제 평형수펌프 용량과 UV BWMS의 유동 에너지 손실을 충분히 고려하는 것이 좋습니다. 또한 BWMS 설치 후 평형수 처리시간 증가를 최소화하기 위해서는 더 큰 용량의 BWMS, 더 큰 파이프 및 내부 코팅이 있는 파이프 등의 사용을 고려할 수 있습니다.

This study was undertaken in an effort to develop a cryopreservation system of immature and mature porcine oocytes. For this aim, the experiments were designed to examine the effect of cryoprotectants and equdibration time on the viability of frozen-thawed oocytes by using trypan blue(TB) and fluorescene diacetate(FDA) test. The viability of frozen immature oocytes evaluated by TB test was slightly higher than that of frozen mature oocytes. The viability(25.O%) after IVM of frozen-thawed immature oocytes greatly decreased that(42.9%) of oocytes just after thawing, but it was higher than frozen-thawed mature oocytes(15.8%). When immature oocytes were equilibrated for 10, 20 and 30 minutes before freezing the oocyte viability was 20.0, 31.3 and 42.9%, respectively. There was a tendency for long equilibration before oocyte freezing to be more effective for the immature oocytes and a short equilibration time for mature oocytes. Although there was no difference in viability index of frozen oocytes hetween the viability test methods, the index of TB test was slightly higher than that of FDA test. The viability(FDA test) of frozen-immature oocytes with 3 different crtoprotectants was 22.2% for propylene glycol(PG), 9.3% for polyehtylene glycol(PEG) and 65.6% for PG+PEG, in which PG+PEG was more protective against freezing effect.

The present experirnents on cryopreservation were carried out to investigate effect of solution toxicity, equilibration time and cell stages on the post-thaw survival of mouse morulae and blastocyst embryos cryopreserved by vitrification in EFS solution. The mouse embryos were exposed to the EFS solution in one step at room temperature, kept in the EFS solution during different period for toxicity test, vitrified in liquid nitrogen and thawed rapidly. After the mouse morulae embryos were exposed to EFS solution for 2 and 5 ruin. at room temperature and then they were washed in 0.5 M sucrose solution and basal mediurn(D-PBS + 10% FCS), they were cultured to examined cryoprotectant toxicity induced injury during exposure, most of embryos developed to expanded blastocysts(100 and 90.0%). However, when the exposure time was extended to 10 and 20 min, these development rates dropped dramatically in 10 ruin. (75.0%) and 20 ruin. (4.5%), respectively. When the compacted morulae were vitrified in EFS solution after equilibration for 2 and 5 min, the embryos have developed to normal blastocyst following thawing, washing and culture processes was 89.3 and 89.6%. However, when the exposure time was expanded to 10 ruin, this survival rate dropped to 68.8%. When the blastocyst were vitrified in EFS solution after equilibration for 2, 5 and 10 minutes, the survival rate of embryos which developed to normal blastocyst following thawing and culture processing were 58.5, 46.7 and 22.4%, respectively. The optimal time of equilibration of mouse morula and blastocysts in EFS solution seemed o be 2 and 5 ruin.

The present experiments on cryopreservation were designed to examine the effects of solution toxicity, equilibration time and cell stages on the post-thaw survival of bovine IVF embryos. The oocytes were matured in vitro(IVM) for 24 hrs. in TCM-199 supplemented with 35 g /ml FSH, 10 g /ml LH, 1 g /ml estradiol-17 and granulosa cells at 39 under 5% in air. They were fertilized in vitro(IVF) by epididymal spermatozoa treated with heparin for 24 hrs., and then the zygotes were co-cultured in vitro(IVC) with bovine oviductal epithelial cells for 7 to 9 days. The bovine IVF embryos were exposed to the EFS solution in one step at room temperature, kept in the EFS solution during different period for toxicity test, vitrified in liquid nitrogen, and thawed rapidly. 1. after the bovine blastocysts were exposed to EFS solution for 2 min. at room temperature and then they were washed in 0.5 M sucrose solution and TCM-199, they were cultured to examined cryoprotectant induced injury during exposure, Most of the embryos(95.0%) developed to reexpanded blastocoels. However, when the exposure time was extended to 5 and 10 min, these development rates dropped dramatically in 5 min. (69.5%) and 10 min. (47.4%), respectively, 2. When the bovine IVF embryos were vitrified in EFS solution after the equilibration for 1 and 2 min. exposure, The embryos to have reexpanded blastocoels following thawing, washing and culture processes were found to he 82.6 and 73.9%, respectively. However, when the exposure time was extended to 3 min, this survival rate dropped to 18.2%. The optimal time for equilibration of bovine IVF blastocysts in EFS solution seemed to he 1~2 min. 3. When the bovine IVF embryos were equilibrated for 1 min. the significantly (P<0. 05) higher post-thaw survival rates were obtained from the embryos of blastocyst stage(81.3%) than morulae stage(5. 1%). The optimal cell stage for viterification with EFS solution proven to he blastocyst stage in bovine IVF embryos. 4. The number of blastomeres of blastocyst stage was examined with nuclear staining with Hoechst 33342 during 7 to 9 days post-insemination. The cell counts of frozen bovine IVF embryos were found significantly(P7.5 and those of the fresh embryos 76.67. 1, which were cultured in the sarne period and conditions as frozen embryos.