• 한국수산과학회지
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• 제44권3호
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• pp.290-297
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• 2011

The phenology of Campylaephora hypnaeoides J. Agardh and optimal conditions for carpospore release, growth and reproduction were examined in the field and in the laboratory from January to December 2007. In the field population of C. hypnaeoides, approximately 50% of the plants were vegetative during the study period. Additionally, the percentages of carposporophytes and tetrasporophytes were maximal in April (37%) and June (57%), respectively. Maximum growth in plant length, dry weight, and hook number coincided with the tetrasporophyte reproductive peak in the field. In culture, carpospore release, sporeling growth and reproduction were affected by environmental factors such as daylength, temperature, and salinity. The liberation of carpospores was maximum under continuous light and at a combination of $15^{\circ}C$ and $10\;{\mu}mol$ photons $m^{-2}\;s^{-1}$. Maximum growth of tetrasporophyte sporelings occurred at a combination of $20\;{\mu}mol$ photons $m^{-2}\;s^{-1}$ of constant light and $25^{\circ}C$. However, the growth of gametophyte sporelings was maximal under $40\;{\mu}mol$ photons $m^{-2}\;s^{-1}$ of constant light and in a combination of $20^{\circ}C$ and 35 psu. The tetrasporophyte sporelings were grew faster than gametophytes, indicating that gametophyte- and tetrasporophyte-sporelings have different physiological responses to irradiance and temperature. Tetrasporangial branches and cystocarps of C. hypnaeoides were produced from carpospores and tetraspores within 1 month, and they were stimulated at high temperature and irradiance levels. In conclusion, C. hypnaeoides should be seeded using carpospores during early winter (November-December) because cystocarps are easily identified by fishermen, and tetrasporophytes grow faster than gametophytes.

• 수산해양기술연구
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• 제43권4호
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• pp.329-338
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• 2007

Data collected by on-board observers and from experimental surveys during 2004-2006 were analyzed to figure out the status of shark bycatch in Korean tuna longline fishery. Results obtained from 10 surveys indicated that 14, 13 and 1 species of shark were incidentally caught in Korean tuna longline fishery operated in the Pacific, Indian and Atlantic (Mediterranean) Ocean, respectively, and that shark bycatch accounted for about 29-31% of the total catch. Sharks brought aboard were processed in 3 ways; out of 1,127 sharks observed, 575 sharks (51.0%) were discarded after finning, 299 sharks (26.5%) were stored frozen after finning for future use and 253 sharks (22.4%) were released into the sea immediately after caught. The fin to body weight ratio of sharks was estimated to be about 4.7% which is similar to the guideline of 5% established by the international fisheries organizations. The underestimate of shark bycatch in Korean tuna longline fishery was significant because it was general practice that fishermen on-board did not count the discarded shark as a catch.

• 수산해양기술연구
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• 제43권4호
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• pp.310-319
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• 2007

To investigate the catches of squid jigging fishery, a series of fishing experiments was conducted in the high seas of the Northwest Pacific($40^{\circ}-43^{\circ}N$, $150^{\circ}-155^{\circ}E$) during the period of 1 August to 22 October 2005 by commercial fishing vessel. The number of 142 test fishing was carried out in the Northwest Pacific during 83days. The total catch were 47,524kg as 4 squid species and CPUE was $8.9kg/line{\cdot}day$. CPUE showed high values in the frontal zone during the survey. Main squid species caught from the experimental fishing were the neon flying squid, Ommastrephes bartrami(96.8%) and the boreopacific gonate squid, Gonatopsis borealis(3.2%). Dorsal mantle length of the neon flying squid were increased by the time and increasing of the hook size. Loss rate of the neon flying squid in the water showed the highest values in 28.2% compare to the others. And the loss rate of the front roller and in the air were 1.1% and 1.0%, respectively.

• Advances in Traditional Medicine
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• 제9권2호
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• pp.174-181
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• 2009

Pterocarpus marsupium, Clitoria ternatea, and Sanseveiria cylindrica are some of the important and endangered medicinal plant species of India. Despite of medicinal properties, antibacterial potential of the plants have not yet been explored. The present study was designed to optimize the in vitro technique for micropropagation and to screen the extracts from leaves and in vitro raised calli for antibacterial properties. Excised leaf-explants from the parent plants were surface sterilized and cultivated on Murashige & Skoog's (MS) medium containing $N^6$-benzyladenine (BA) in concentrations of 1, 2, 5, and $10{\mu}M$. Optimal growth of calli was noticed at a concentration of $5{\mu}M$, therefore the extracts from calli grown at this concentration were further studied for antibacterial activity. Both alcoholic and aqueous extracts from leaves of respective plants, and their in vitro raised calli were tested for antibacterial activity by agar well diffusion method against a range of Gram-positive and Gram-negative bacteria. Aqueous extracts showed antibacterial activity against limited number of bacterial species; notably the extracts of C. ternatea which showed antibacterial activity against Streptococcus pyogenes, Bacillus subtilis and Bacillus cereus. Alcoholic extracts of all three plants showed antibacterial activity against a wider range of bacteria. Among the Gram-positive bacteria, extracts from C. ternatea showed strong antibacterial activity against Bacillus spp., whereas the extracts of S. cylindrica showed good antibacterial potential for Staphylococcus aureus, S. epidermidis and S. pyogenes. The extracts from all three plants showed antibacterial activity against Gram-negative bacteria, including, Salmonella spp. and Shigella dysenteriae; organisms causing enteric fever and dysentery. In most of the cases, the extracts from respective calli showed comparable, and in some cases better, result in comparison to the extracts from parent leaves. To the best of our knowledge this is the first preliminary report on antibacterial potential, especially through calli extracts, of these plants; and in vitro cultivation of the explants may be used to obtain phytotherapeutic compounds.

• 한국표면공학회지
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• 제45권5호
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• pp.181-187
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• 2012

The Friction Stir Welding (FSW) has mainly been used for making butt joints in Al alloys. The development of Friction Stir Lap Welding (FSLW) would expand the number of applications. In this study, microstructures and mechanical properties of FSLW in A5052 alloy were investigated under varying rotating speed and probe length. Investigating the characteristics as FSLWed conditions were as below ; Failure Maximum load by shear fracture was increased proportional to the width of joint area, which was increased by input heat, stirring intensity in the case of 2.3 mm probe length. Tensile fracture occurred, and maximum load was determined due to side worm hole of joint area and softening of microstructure in the case of 3.0 mm probe length. In the case of 3.7 mm probe length, material hook and bottom worm hole were appeared at the end interface of joint area. The most sound FSLW condition with no defects was 3.0 mm probe length and 1500 rpm-100 mm/min. No defects were showed in 1500 rpm-100 mm/min and 1800 rpm-100 mm/min, but Vickers microhardness distribution in TMAZ/HAZ which was fracture zone was lower in 1800 rpm-100 mm/min than in 1500 rpm-100 mm/min. In this condition highest tensile strength, 215 MPa (allowable rate 78% of joint efficient) was obtained.

• 한국작물학회지
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• 제49권3호
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• pp.216-221
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• 2004

콩나물 재배에서 생장조절제 BA 흡수량은 처리방법에 따라 커다란 영향을 받는다. 본 연구는 BA 처리효과를 극대화하여 처리량을 줄일 수 있는 방법을 모색하고자 BA 처리 직후 첫 관수까지 경과시간이 콩나물의 생장과 세근발생에 미치는 영향을 조사하기 위하여 2 ppm BA용액에 5시간 침종한 풍산 나물콩, 소원콩 및 준저리의 종자를 재배시 첫 관수까지 20, 30 및 $40^{\circ}$로 aeration 온도를 달리하거나, $25^{\circ}$에서 1, 2, 3, 4시간으로 aeration기간을 달리하여 처리한 후에 6일간 재배한 결과를 요약하면 다음과 같다. 1, 침종과 첫 관수간 aeration온도 및 기간에 따라 각공시품종의 발아 및 생장 정도는 다른 것으로 조사되었다. 2. 콩나물의 발아 및 생장, 세근발생 개체비율, 개체당 세근수 및 생체중은 BA 용액에 침종한 후 첫 관수까지의 aeration온도의 영향은 미미한 반면, 공시품종의 영향을 크게 받는 것으로 조사되었다. 3. 세근발생 개체비율은 aeration기간을 4시간으로 길게 할수록 감소하였던 반면, 개체당 세근수는 3시간 이상의 aeration 기간간에는 차이가 없었다. 4. 하배축 및 뿌리의 길이는 1시간의 aeration을 가할 경우 가장 길었으나, 3시간 이상 aeration을 가할 경우 차이가 없었다. 5. 자엽, 하배측, 뿌리 및 전체 생체중도 1시간 aeration을 가할 경우 가장 많았으며, 3시간 이상 aeration을 가할 경우 차이가 없었다

• 한국구조물진단유지관리공학회 논문집
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• 제21권2호
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• pp.34-45
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• 2017

본 연구에서는 소규모 철골조에 대한 기존 건축물의 접합부 현황조사와 분석을 통해 노출형 주각부에 대한 내진성능을 평가하였다. 총 9개의 주각부에 대한 반복가력 실험을 통해 휨강도, 변형능력, 그리고 초기강성 등이 조사되었다. 실험의 주요 변수는 베이스 플레이트의 두께, 앵커볼트의 개수와 매립깊이, 앵커볼트 후크의 유무, 그리고 리브 플레이트의 유무이다. 본 실험결과에 의하면, 주각부의 휨거동은 앵커볼트의 개수와 매립깊이, 그리고 베이스 플레이트의 두께에 영향을 받는 것으로 나타났다. 반면에, 주각부에 설치된 리브플레이트는 휨강도에 큰 영향을 주지 않는 것으로 나타났다. 종합적으로 노출형 철골 주각부와 기초부 그리고 앵커볼트 등이 모두 현행 구조기준을 만족한다고 할지라도, 앵커볼트와 기초부 콘크리트 사이의 부착력이 충분하지 않을 경우, 슬립형 거동이 관측되어 개선이 필요한 것으로 파악되었다. 앵커볼트의 매립깊이가 현행 구조기준을 만족하고, 앵커볼트에 후크가 설치된 경우, 노출형 주각부의 초기강성은 주각부가 구속되었을 때의 휨강성 하한값의 약 15% 수준인 것으로 나타났다.

• 한국자원식물학회지
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• 제21권1호
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• pp.23-27
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• 2008

전래적으로 숙주나물은 저장성을 높이기 위하여 세척하지 않고 탈수시켜 이용하여 왔다. 본 연구는 생산된 숙주나물의 수분 함량과 관련된 세척이 제품의 저장성에 미치는 영향을 파악하기 위하여 포장하기 직전 물에 씻거나 씻지 않는 세척 유무가 5일간 저장중 숙주나물의 형태 및 무게에 미치는 영향을 조사한 결과를 요약하면 다음과 같다. 1. 무세척 숙주나물에 비하여 세척시킨 숙주나물은 저장 4일 후까지 수분 함량이 높은 것으로 나타났다. 2. 무세척 숙주나물은 세척시킨 숙주나물에 비하여 저장중 형성된 개체당 세근수가 많았던 반면, 하배축과 뿌리 길이, 하배축 중간과 hook 부분의 직경, 각부위 및 전체 생체중과 건물중에서는 세척 유무간에 차이가 없었다. 3. 무세척 숙주나물은 세척시킨 숙주나물에 비하여 하배축 및 뿌리의 탁도, 하배축의 전단력이 높았던 반면, 색도 a와 b에서 세척 유무간 차이가 없어 저장중 무세척 숙주나물의 품질 저하가 적은 것으로 나타났다. 4. 무세척 숙주나물에서 세근수, 하배축 길이, 하배축 중간부분의 직경, 하배축과 전체 생체중 및 건물중은 저장 후 3일까지 변화가 없었으나 그 이후 감소하는 경향을 보였다. 5. 무세척 숙주나물에서 하배축의 전단력은 저장 4일 후부터, 하배축의 명도와 색도 b는 저장기간이 길어질수록 감소하는 경향을 보였다.

• 한국수산과학회지
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• 제2권2호
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• pp.161-172
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• 1969

Ten experimental tuna long line fishing operations were performed with the long lines A and B, in combination casting orders of BA and AB. The long line B differs from A in its additional main line length per basket and its greater depth of submersion (Table 1). The BA casting order results in an AB hauling order, so that the long line B is casted at an earlier time of a day and fishes for a longer period than A line (fig. 2). The number of fish caught was divided into subclasses in order to be subjected to $x^2-tests$ (Table 2). The first series of $x^2-tests$ were calculated using the hooking rates of two subclasses with other factors pooled (Table 3). The second series of $x^2-tests$ were calculated to obtain the interactions between two subclasses when other factors differed (Table 4). Attention was paid to the extremely small interactions as well as to the large interactions in order to find out whether a factor functions in the same way or in a contradictory way when the other factors involved differ. The test result is summarized in Table 5. The relationship between the hook casting time (relative to the sunrise time) and the hooking rates reveals the feeding behavior of particular species (fig. 3) A high hooking rate for yellowfin tuna shown in the period from one hour before sunrise to the moment of sunrise suggests that they feed actively in that period. Their poor hooking rate on earlier casted hooks suggests that they do not feed well under conditions of darkness and that they feed best while the hooks are sinking. Furthermore it is likely that yellowfin tuna maintain a shallow depth in the daytime, for the $x^2$ interaction between the line casting order BA and AB shows their persistant preferance of the long line A regardless of line casting order. Bigeye tuna show their feeding behavior under conditions of darkness, and show a preference for the sea's deeper layer. Alepisaurus borealis (Gill) show their feeding behavior under conditions of darkness more significantly than the bigeye tuna and their preferance for deep layers is also more significant. Marlins (mainly Makaria mazara) show a feeding behavior which is similar to the yellowfin tuna. The author emphasizes that certain variations of the hooking rates in relation to the line easting time were caused by an inadequate fishing depth as well as by the fish preference for a particular feeding time. When the part of the line casted in pre-dawn hours and hauled in the pre-sunset hours show a significantly lower hooking rate than other parts of the line, then it is concluded that tile hooks settled in a sea layer too deep for feeding.

• 식물분류학회지
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• 제39권4호
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• pp.277-291
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• 2009

속리산 국립공원 지역(북위 $36^{\circ}28^{\prime}05^{{\prime}{\prime}}{\sim}36^{\circ}46^{\prime}38^{{\prime}{\prime}}$, 동경 $127^{\circ}47^{\prime}06^{{\prime}{\prime}}{\sim}127^{\circ}57^{\prime}50^{{\prime}{\prime}}$)에 자생하는 식물상을 밝히고 주요 식물들의 분포를 파악하였다. 2000년 4월부터 2006년 7월까지 총 26회에 걸친 현지조사를 실시한 결과 속리산 국립공원의 관속식물은 115과 392속 629종 4아종 72변종 18품종의 총 723분류군으로 정리되었다. 이 중에서 기존의 조사에서는 발견되지 않았으나 본 조사에서 최초로 밝혀진 분류군은 93분류군이었다. 속리산 국립공원에 자생하는 식물들 중에서 한국 특산식물 27분류군, 희귀 및 멸종위기식물 19분류군, 환경부 지정식물구계학적 특정식물 중에서 등급III 이상에 해당하는 45분류군 등이 생육하고 있었으며, 29분류군의 한국 귀화식물이 밝혀졌다. 속리산 국립공원에서 자생하는 특기할만한 식물들 중에서 특히, 고란초, 백작약, 깽깽이풀, 등대시호, 가지더부살이, 솔나리, 천마, 꼬마은난초는 개체수가 적거나 식물지리학적으로 중요한 식물로서, 자생지보전에 대한 적절한 대책이 마련되어야 할 것으로 판단된다.