This study was performed in order to determine optimum flushing solution using the direct embryo collection (DEC). Donors, at random stages of the estrous cycle, received a CIDR. 7 days later, 200 mg FSH was treated with 40, 30, 20, 10 mg FSH levels in declining doses twice daily by intramuscular injection for 4 days. On the 3 day administration of FSH, 25 mg was administered and CIDR was withdrawn. After FSH injections were complete, donors were artificially inseminated twice at 12 hr intervals. The donor cattle received 250 GnRH at time of 1 insemination and embryos were recovered 8 days after the 1 insemination. Embryo collection from superovulated donors were performed to flushing by DEC and conventional method. As a results, the average number of recovered embryos were significantly higher as 19.11.40 with DEC method than 12.00.44 with conventional embryo collection method, respectively (p<0.05). Also, The average number of transferable embryos were significantly higher (p<0.05) as 15.81.72 with DEC method than 6.90.35 from conventional embryo recovery procedures. Meanwhile, number of recovered embryos and number of recovered transferable embryos following the number of flushing times until 6 flushing were significantly higher as 8.60.53 and 8.60.53 from 2 flushing time than other groups (p<0.05). No. of Ear. B stage embryos were significantly higher as 3.90.90 and 3.90.90 with 2 flushing time in total collected embryos and transferable embryos (p<0.05). Com M stage embryos were significantly higher as 3.71.00 in 2 flushing time and as 2.20.76 in 3 flushing time for recovered embryos (p<0.05). In transferable embryos, Com. M stage embryos were significantly higher (p<0.05) as 3.71.00 in 2 flushing time and as 2.20.76 in 34 flushing time, also. No. of degradation embryos was significantly higher as 2.20.72 in 5 flushing time, On the other hand, degradation embryos was not observed in transferable embryos (p<0.05). In conclusion, these results suggest that DEC method should effective methods for production of in vivo embryos using less flushing solution following perform until 4 flushing time than conventional embryo collecting method. Also, it might be effectively collection of transferable embryos following more less procedure times compared to conventional embryo recovery methods.

This study was performed in order to simplify the operation and minimize stress of donor and be readily available in the field with low cost and high quality embryos using the Direct Embryo Collection (DEC). Donors, at random stages of the estrous cycle, received a CIDR. 7 days later, 200 mg FSH was treated with 40, 30, 20, 10 mg FSH levels in declining doses twice daily by intramuscular injection for 4 days. On the 3rd day administration of FSH, 25 mg was administered and CIDR was withdrawn. After FSH injections were complete, donors were artificially inseminated twice at 12 hr intervals. The donor cattle received 250 GnRH at time of 1 st insemination and embryos were recovered 8 days after the 1st insemination. Embryo collection from superovulated donors was performed to flushing by non-surgical methods of 3-way, 2-way and DEC (l-way). The average number of recovered embryos were 11.250.63, 12.50.65 and 11.750.48 from operations of 3-way, 2-way and DEC methods, respectively. There were no significant differences among the embryo collection methods. Also, The average number of transferable embryos were 6.250.48, 7.250.48 and 7.250.63 from each embryo collection procedures. The number of transferable embryos was no differences among the 3-way, 2-way and DEC methods, respectively. Meanwhile, the ratio of transferable embryos for all recovered embryos from DEC methods was higher as 61.7 % than 55.6 %, 58 % from methods of 3-way, 2-way. And the flushing solution required for recovering embryos by DEC method was significantly lower as 0.280.32 1 than 1.80.12 1, 1.750.10 1 from 3-way, 2-way methods (p<0.05). Also, the time required for recovering embryos by DEC methods was significantly lower as 272 min than 513, 452 min, respectively (p<0.05). In conclusion, these results suggest that DEC method for embryo collection may be effectively used for production of in vivo embryos using less flushing solution and, it might be effectively available in the field compared to conventional embryo recovery methods using 3-way or 2-way balloon catheter.

휘발성 유기화합물(VOCs)은 유기용매를 주로 사용하는 산업공정에서 배출되는 일반적인 대기오염물질 중 하나로 그 물질 자체가 독성 및 발암성을 지니기도 하고 오존 생성의 전구체로 작용하기도 하여 인체 건강과 환경에 부정적인 영향을 주고 있다. 또한 최근 초미세먼지 2차생성에 기여하고 있음이 알려짐에 따라 VOCs 저감에 대한 국제적인 관심은 더욱 높아지고 있는 실정이다. 중소규모 사업장에서는 VOCs 처리를 위해 주로 활성탄 흡착탑을 이용하고 있으며 활성탄의 짧은 파과점으로 일정기간 사용 후 교체가 필요하지만, 교체 비용 부담에 따른 적절한 유지관리가 미흡하여 VOCs가 직접 대기로 방출되는 문제가 발생되고 있다. 따라서 본 연구에서는 활성탄 파과 후 현장에서 재생이 가능한 흡탈착 공정에 대하여 연구를 수행하였다. 기존 재생 공정인 열탈착(TSA) 공정은 에너지 비용이 많이 소요되며 수분 또는 고온 가스를 사용해야하므로 재생 시간이 길고 부대시설이 필요한 단점이 있어 현장에서 흡착 후 직접 재생하기에는 다소 무리가 따른다. 저온 감압탈착(VSA) 공정은 상대적으로 저온(80∼90℃)에서 진공펌프를 이용하여 탈착하는 방식으로 감압시에 VOCs가 휘발하는 온도가 낮아지므로 상대적으로 낮은 온도에서 탈착이 가능하다. 이에 따라 현장에서 자체재생 가능한 탈착 방법으로 저온 VSA 기술을 적용하였으며, 30 CMM급 흡탈착 시스템을 제작하여 실제 도장 공장의 배출가스에 대한 현장 적용성 연구를 수행하였다. 또한 저온 VSA 공정을 통해 배출되는 탈착가스는 재생시 캐리어가스 유량이 상대적으로 적어 고농도로 배출되므로 회수하여 유기용매로 재활용할 경우 원료 절감에 따른 경제적 효과가 매우 크다. 따라서 VOCs를 회수하기 위한 방법으로 기액 접촉 효율이 높은 용매 직접접촉식 응축 방식을 적용하였으며, 30 LPM 직접접촉식 회수장치를 제작하고 실 탈착가스를 이용한 회수실험을 수행함으로써 본 기술에 대한 현장 적용 가능성에 대하여 평가해보고자 하였다.

To ensure the successful launch of the Korea pathfinder lunar orbiter (KPLO) mission, the Korea Aerospace Research Institute (KARI) is now performing extensive trajectory design and analysis studies. From the trajectory design perspective, it is crucial to prepare contingency trajectory options for the failure of the first lunar brake or the failure of the first lunar orbit insertion (LOI) maneuver. As part of the early phase trajectory design and analysis activities, the required time of flight (TOF) and associated delta-V magnitudes for each recovery maneuver (RM) to recover the KPLO mission trajectory are analyzed. There are two typical trajectory recovery options, direct recovery and low energy recovery. The current work is focused on the direct recovery option. Results indicate that a quicker execution of the first RM after the failure of the first LOI plays a significant role in saving the magnitudes of the RMs. Under the conditions of the extremely tight delta-V budget that is currently allocated for the KPLO mission, it is found that the recovery of the KPLO without altering the originally planned mission orbit (a 100 km circular orbit) cannot be achieved via direct recovery options. However, feasible recovery options are suggested within the boundaries of the currently planned delta-V budget. By changing the shape and orientation of the recovered final mission orbit, it is expected that the KPLO mission may partially pursue its scientific mission after successful recovery, though it will be limited.