The present study was undertaken to determine the optimal condition for parthenogenetic activation of rabbit oocytes by electric stimulation in vitro in an attempt to develop nuclear transplantation techniques for cloning mammalian embryos and animals. Freshly ovulated oocytes were collected from superovulated rabbits from 13 to 26 hrs. after hCG injection. The cumulus-free oocytes were activated parthenogetically by repeated stimuli of square direct electric pulses in O.3M mannitol solution. After applying electric stimulations of different voltages, pulse durations and pulse times, all of the oocytes were cultured in TCM-199 with 10% FCS for 96 hours in a 5% incubator, and their developmental potential in vitro was examined. The higher activation rate (68.9%) was achieved at the voltage of 2.0kv/cm, the pulse duration of 60 sec and three pulse times and the activation rate of 100% was achieved at the pulse duration of 100 and 200 sec, the voltage of 1.5kv/cm and three pulse times. Although the higher rates of activation of oocytes were achieved at 100 and 200 sec, none of them developed to blastocyst in vitro. The oocytes collected 18~20 hours post hCG injection showed the highest rate of activation and development to blastocyst in vitro than the oocytes collected 13~15 or 25~26 hours post hCG injection. Therefore, it can be suggested that the application of electric stimulation of 2.0kv/cm, 60 sec and three pulse times to the oocytes collected at 18~20 hours post hCG injection would be more beneficial for the parthenogenetic activation of oocytes in rabbits.

본(本) 시험(試驗)은 고랭지(高冷地) Timothy 우점초지에서 목초(牧草)의 적정(適正) 예취회수(刈取回數)와 최종(最終) 예취시기(刈取時期)를 구명(究明)하고자 DM 생산량(生産量), 월동후(越冬後) 초기생육특성(初期生育特性), 다음해 1차수량(次收量) 조단백질(粗蛋白質) 및 조섬유(粗纖維) 생산량(生産量)을 조사(調査)하고 그들간(間)의 상관관계(相關關係)를 분석(分析)한 결과(結果)를 요약(要約)하면 다음과 같다. 1. 초기생육(初期生育)이 개

This experiment was carried out in order to study the effect of fertilizer application and seasonal changes on the productivity of the native reed (Phragmites communis Trinius) on the reclaimed tidal flate in Chonnam province.

전남지역(全南地域)의 간척지(干拓地), 간사지(干潟地) 및 하천제방(河川堤防) 등에 널리 자생(自生)하고 있는 갈대에 대(對)하여 1982년(年) 5월(月)부터 동년(同年) 10월(月)까지 전남 영암군 군서면 해창리, 함평군 학교면 곡창리, 광양군 진월면 망덕리 지역(地域)의 간척지(干拓地), 하천제방(河川堤防) 및 간석지(干潟地)를 중심(中心)으로 생육시기별(生育時期別), 지역별(地域別) 수량(收量), 영양소(營養素) 함량(含量) 및 in-vitro

2016년 환경부가 한반도 미유입 환경위해우려종으로 고시한 41분류군을 대상으로, 분류학적 특징을 이용하여 종을 동정하 는 방법을 제공하고 또한 자생지의 분포 및 환경 특성에 대한 정보를 제공하기 위하여 본 연구를 수행하였다. 이를 위하여 국외의 여러 표본관에 소장된 건조표본을 확인하였으며, 미국 서부 지역인 캘리포니아주, 오레곤주 및 워싱턴주의 현장조사를 수행하였다. 우선, 조사 결과의 일부로 미국 서부 농업지역을 중심으로 분포하는 Carduus acanthoides L. (국화과), Carduus tenuiflorus W. Curtis (국화과), Onopordum acanthium L. (국화과), Chromolaena odorata (L.) R.M. King & H. Rob. (국화과), Hydrocotyle ranunculoides L.f. (산형과), Oenanthe pimpinelloides L. (산형과), Ehrharta erecta Lam. (벼과), Paspalum conjugatum P.J. Bergius (벼과)의 8종에 대하여 위해성 검토, 잡초위험평가, 분류학적 특징 및 국내외 유사종과의 비교 검색표를 제시하였다.

콘크리트는 외부로부터 침투하는 열화 인자들의 침투에 의해 철근이 부식하고 구조재료로써의 성능이 저하된다. 발수제를 직접 도포하거나 혼입하는 방법이 연구되고 있고, 본 연구에서는 발수제의 뭉침 및 떠오름을 방지하기 위하여 다공성 재료인 제올라이트를 혼입한 발수콘크리트 개발을 위한 기초연구를 수행하였다. 제올라이트 치환율에 따른 시험체를 제작하였으며, 접촉각 측정결과 치환량과 접촉각의 크기는 비례하여 증가하는 것을 확인하였다.

본 연구는 경기도 파주시에 위치한 파평산의 관속식물상 조사를 위하여 수행하였으며, 이를 토대로 고유종, 희귀 및 멸종식물, 적색식물, 기후변화적응대상 식물, 귀화식물을 조사하였다. 2016년 4월부터 2019년 6월까지 총 13회에 걸쳐 현지조사를 실시한 결과 91과 257속 361종 9아종 36변종 4품종으로 총 410분류군이 확인되었다. 과별로 보면 국화과(46분류군), 벼과(31분류군), 장미과(27분류군), 콩과(18분류군) 순으로 높게 나타난다. 이 중 Chung 등이 지정한 특산식물은 9분류군, 환경부가 지정한 고유종은 6분류군이다. 희귀 및 멸종위기 식물은 IUCN 평가기준을 근거로 국립수목원이 지정한 멸종위기식물 13분류군이, 환경부가 지정한 적색자료집을 근거로 2분류군이 확인된다. 식물구계학적 특정식물은 Ⅳ등급 2분류군, Ⅲ등급 13분류군, Ⅱ등급 11분류군, Ⅰ등급 20분류군으로 총 46분류군이다. Lee (1976)에 따른 자원식물은 식용 182분류군(44.39%), 목초용 166분류군(40.49%), 약용 138분류군(33.65%), 관상용 53분류군(12.93%), 목재용 22분류군(5.37%), 다용도 11분류군(2.68%), 섬유용 6분류군(1.46%), 산업용 1분류군(0.24%) 순이며, 산림청 지정 자원식물은 식용 293분류군(71.46%), 산업용 186분류군(45.37%), 다용도 173분류군(42.20%), 의약용 125분류군(30.48%), 유해성 식물 84분류군(20.49%), 향료 16분류군(3.9%)순이다. 기후변화 적응대상식물은 7분류군이 확인되었으며, 귀화식물은 27분류군으로 귀화율 6.58%, 도시화지수 8.43%를 나타내었다. 본 파평산 일대의 조사로 본 결과는 파주 북부의 DMZ 접경지역의 자연환경 및 자연자원의 조사 및 보존에 필요한 기초자료로 활용될 수 있을 것으로 판단된다. 한편, 증거표본을 기준으로 하여 관속식물 목록을 작성하였기 때문에 조사과정에서 누락되었을 가능성을 고려하면 파평산의 관속식물의 다양성은 더 높아질 수 있을 것이다. 이러한 조사 연구를 통해 최근 높은 빈도로 발생하는 산불의 예방, 인위적 간섭에 의한 외래식물의 침입 및 산림훼손의 방지 등을 더 정확히 파악하고, 그를 활용할 더욱 적극적이고 다양한 노력이 필요할 것이다.

This research and development analysis provides numerical analysis techniques that can be used conveniently to determining the safety of the current state and to predict the stability in the future. It also seeks to present algorithms of back analysis to develop unified management system for control, prediction, coordination, and information modeling that can reasonably handle appropriate responses to structural behavior at project sites and design changes.

In this study, the impedance of reinforced concrete embedded in concrete was measured and compared with W/B and admixture replacement ratio. As a result, the impedance of rebars increased in all frequency sections with increasing blast furnace slag replacement amount of cement in all W/B Respectively. It is considered that the electro resistance in the concrete increases due to the potential hydraulic properties of the blast furnace slag, and thus the polarization resistance also increases.

This study was carried out to investigate the flora of Deokjeongsan Mt. (Ganghwa-gun) from March to October 2016. The vascular plants identified during the 8 round field surveys were a to total of 484 taxa: 107 families, 305 genera, 423 species, 8 subspecies, 48 varieties, 4 forms and 1 hybrid. The plant formation of Deokjeongsan Mt. is the deciduous broad-leaved and conifer mixed forest which is the common one in the middle part of Korean peninsula. All most mountain covered with young secondary forest which is mainly composed of Pinus and Quercus. The plant species diversity largest families were Asteraceae (62 taxa, 12.7%), Poaceae (48 taxa, 9.9%), Cyperaceae (27 taxa, 5.6%), Fabaceae (23 taxa, 4.7%), and Lamiaceae (21 taxa, 4.3%). The four taxa of Korean endemic plants such as Clematis brachyura Maxim., Salix koriyanagi Kimura ex Goerz, Carex brevispicula G. H. Nam & G. Y. Chung, and Hemerocallis hakuunensis Nakai were collected. The vascular plants on the red list according to IUCN evaluation basis were found to be five taxa: Near Threatened (NT) species of Senecio argunensis Turcz., Least Concern (LC) species Pseudoraphis ukishiba Nakai, and Not Evaluate (NE) species of Thladiantha dubia Bunge, Cirsium lineare (Thunb.) Sch. Bip., and Scorzonera austriaca ssp. glabra Lipsch. & Krasch. ex Lipsch., respectively. The floristic regional indicator plants found in this area were 26 taxa comprising one taxa of degree V, two taxa of degree IV, four taxa of degree III, eight taxa of degree II, and 11 taxa of degree I. In addition, the alien plants were identified as 46 taxa and the percentage of naturalized index (NI) was 9.5%, and urbanization index (UI) was 14.3%, respectively

This study investigated the properties of lightweight foamed concrete by using surfactant and synthetic foaming agent, lightweight aggregate. The effects of foaming agent types and replacing ratio of lightweight aggregate on the compressive strength, density and pore structure of the concrete were investigated. This study showed the improvement of important properties of lightweight foamed concrete. Lower pore distribution and correspondingly higher compressive strength values were reached. Also, synthetic foaming agent had more positive effect on the strength of foamed concrete.

This study investigated the properties of foamed concrete by using surfactant foaming agent and synthetic foaming agent. The effects of foaming agent types on the compressive strength, density and pore structure of the concrete were investigated. The samples were assessed by XRD analysis and simultaneous SEM was used to study their pore distribution. This study showed the improvement of important properties of foamed concrete. Lower pore distribution and correspondingly higher compressive strength values were reached. Also, synthetic foaming agent had more positive effect on the strength of foamed concrete.

This study investigated the properties of foamed concrete by using surfactant foaming agent and synthetic foaming agent. The effects of foaming agent types on the compressive strength, density and pore structure of the concrete were investigated. The samples were assessed by XRD analysis and simultaneous SEM was used to study their pore distribution. This study showed the improvement of important properties of foamed concrete. Lower pore distribution and correspondingly higher compressive strength values were reached. Also, synthetic foaming agent had more positive effect on the strength of foamed concrete

In this study, discover vulnerable elements of Road Tunnel by database and analyzing inspection reports. And provide the data so that can explore ways to improve and feedback.