• 제목/요약/키워드: smooth water

검색결과 407건 처리시간 0.028초

우리나라 서해 연안에서 잡힌 귀상어 임신개체 (A Pregnant Smooth Hammerhead Sphyrna zygaena, Collected in the Western Coastal Water, Korea)

  • 최윤
    • 한국어류학회지
    • /
    • 제30권3호
    • /
    • pp.167-169
    • /
    • 2018
  • 2014년 6월 13일에 충청남도 보령시 연안의 안강망에 의해 귀상어 1개체가 포획되었으며, 이 귀상어는 모두 23마리의 새끼를 임신하고 있었다. 성비는 수컷 12마리, 암컷 11마리였고, 새끼 상어의 전장범위는 49.0~54.7 cm였다. 이러한 전장범위는 귀상어의 태어날 때 크기이며, 우리나라 서해 연근해가 귀상어의 출산장인 것으로 판단된다.

수평단관 상의 유하액막 열전달 (Falling Film Heat Transfer on a Horizontal Single Tube)

  • 김동관;김무환
    • 설비공학논문집
    • /
    • 제12권7호
    • /
    • pp.642-648
    • /
    • 2000
  • Falling film heat transfer analyses with aqueous lithium bromide solution were peformed to investigate the transfer characteristics of the copper tubes. Finned(knurled) tube and a smooth tube were selected as test specimens. Averaged generation fluxes of water and the heat transfer performances(heat flux, heat transfer coefficient) were obtained. The results of this work were compared with the data reported previously. As the film flow rate of the solution increased, the generation fluxes of water decreased for both tubes. The reason is estimated by the fact that the heat transfer resistance with the film thickness increased as the film flow rate increased. The effect of the enlarged surface area at the knurled tube was supposed to be dominant at a small flow rate. The generation fluxes of water increased with the increasing degree of tube wall superheat. Nucleate boiling is supposed to occur at a wall superheat of 20 K for a smooth tube, and at 10 K for a knurled tube. The heat transfer performance of the falling film was superior to pool boiling at a low wall superheat below 10 K for both tubes tested. The knurled tube geometry showed good performance than the smooth tube, and the increased performance was mainly came from the effect of the increased heating surface area.

  • PDF

위저부 평활근 운동에 대한 국산과 중국산 지실의 효능 (Effects of Ponciri Fructus and Aurantii Fructus Immaturus on the Gastric Fundus Motility)

  • 김태완
    • 한국임상수의학회지
    • /
    • 제30권1호
    • /
    • pp.27-31
    • /
    • 2013
  • We investigated the effects of Ponciri Fructus (PF) and Aurantii Fructus Immaturus (AI) on the cicular and longitudinal smooth muscle of rat gastric fundus. Methanol extracts of PF (PFM) and AI (AIM), water-fractions (PFW, AIW) and chloroform-fractions (PFC, AIC) of the extracts induced relaxation in the rat fundic circular muscle pre-contracted by U46619. All extracts showed relaxation without significant differences among the extracts. In the longitudinal smooth muscle, PFM and its water fraction, PFW, showed multiphasic effects, fast relaxation and rebound contraction followed by lasting relaxation. AIM and AIW showed diphasic effects, transient contraction followed by lasting relaxation. However, PFC and AIC induced only relaxation in the rat fundic longitudinal muscle contracted by U46619. PFM showed significantly more effective relaxation compared with PFW, AIM and AIW. Hesperidin, flavonoids known as common constituent of PF and AI and it's an aglycon, hesperetin, induced relaxation in both fundic circular and longitudinal smooth muscle pre-contracted by U46619. Poncirin, known as flavonoid content of PF showed also induced relaxation in the both circular and longitudinal smooth muscle pre-contracted by U46619. These results suggest that both PF and AI has relaxing effects on the gastric fundus smooth muscle and its effects might be caused by their flavonoids constituents.

행소음전탕액(杏蘇飮煎湯液)이 가토혈장(家兎血漿) COTISOL농도(濃度) 및 $PCO_2,\;CO_2$와 GUINEA PIG의 기관지(氣管支) 평활근(平滑筋)에 미치는 영향(影響) (Studies on the Effects of Haengsoyeum (杏蘇飮) Water Extract on the Plasma Cortisol Concentration in the Rabbit and the Contraction of Isolated Guinea Pig Tracheal Smooth Muscle)

  • 이승호
    • 대한한방내과학회지
    • /
    • 제13권1호
    • /
    • pp.143-155
    • /
    • 1992
  • The following results were obtained from the observation on the change of plasma cortisol concentration in the experiment of intravenous administration of Haengsoyeum Water Extract in the rabbit. And the effects of Haengsoyeum extract on the contractile force of the isolated guinea pig trachea smooth muscle. 1. In intravenous administration the plasma cortisol concentration increased significantly about 1 hours after with a does of 0.2 ml/kg. 2. In intravenous administration the plasma cortisol concentration increased significantly about from 1 to 3 hours after with a does of 0.4 ml/kg. 3. The contractile response of the trachea smooth muscle of isolated guinea pig to histamine $10^{-4}\;M$ was significantly inhibited by Haengsoyeum extract. 4. The contractile response of the trachea smooth muscle of isolated guinea pig to acetylcholine $10^{-4}\;M$ was considerably inhibited by Haengsoyeum extract. 5. The contractile response of the trachea smooth muscle of isolated guinea pig to 5-hydroxytryptamine $10^{-4}\;M$ was inhibited by Haengsoyeum extract.

  • PDF

원자적으로 균일한 평판 위에서 움직이는 물 액적에 대한 분자동역학 시뮬레이션 (A Molecular Dynamics Simulation for the Moving Water Droplet on Atomistically Smooth Solid Surface)

  • 홍승도;하만영
    • 대한기계학회논문집B
    • /
    • 제33권8호
    • /
    • pp.559-564
    • /
    • 2009
  • The variation in the shape of water droplet moving on atomistically smooth solid surface in the presence of a constant body force is simulated using molecular dynamics simulation. We investigated how the advancing and receding contact angle of the moving water droplet changes on a solid surface having various characteristic energies. From the MD simulation results, we obtained the density profile defined as the number of water molecules at a given position. Then, assuming the water droplet periphery to be a circle, we calculated the contact angles by using a nonlinear fitting of the half-density contour line. The present simulation clearly shows the different profile of the advancing and receding contact angle for these three different interaction potential between the water droplet and the solid surface.

해양사고 예방을 위한 평수구역 내 파고부이 추가설치 검토 (A Study on the Additional Installation of Coastal Wave Buoys in Smooth Water Areas to Prevent Marine Accidents)

  • 강민균;설동일
    • 한국항해항만학회지
    • /
    • 제47권6호
    • /
    • pp.350-357
    • /
    • 2023
  • 해상특보가 발효되었을 때 평수구역 내에서 선박출항통제 대상에서 제외되는 선박의 무리한 운항으로 인한 사고가 빈번하게 발생하고 있다. 평수구역 내에 설치된 파고부이는 선박출항통제의 주요 참고 지표이며 평수구역 및 연안을 항행하는 선박의 안전과 직결된다고 볼 수 있다. 이 연구에서는 최근 30년간(1991~2020년)의 연안 해양사고, 각 무역항의 주풍향 및 풍속, 2018년 GICOMS 선박 항적 데이터 분석을 통하여 현재 운영 중인 파고부이의 위치 적절성 및 평수구역 내 파고부이 추가설치에 대한 평가를 수행하였다. 연구 결과 국내 주요 무역항인 인천항, 포항항, 울산항 및 부산항에 각 1개의 파고부이 추가설치가 필요하며, 부산항의 경우 파고부이 1개의 위치 이동이 필요한 것으로 검토되었다. 이 연구에서 여러 가지 데이터 분석을 바탕으로 제시된 파고부이의 추가설치 및 이동에 대한 제언은 선박출항통제의 신뢰도 향상 및 안전사각지대 해소에 기여할 것으로 판단된다.

Evaluation of the Antioxidant and Antiproliferative Properties of a Hot-water Extract from Gulfweed, Sargassum fulvellum

  • Kim, So Jung;Kang, Mingyeong;Lee, Taek-Kyun
    • 한국해양바이오학회지
    • /
    • 제10권2호
    • /
    • pp.53-61
    • /
    • 2018
  • Sargassum fulvellum (gulfweed) is a widespread seaweed in the coastal areas of northeast Asia. In the present study, we identified the phenolic compounds present in aqueous and ethanolic extracts of S. fulvellum and evaluated their antioxidative properties and their abilities to block cell proliferation using in vitro assays: antioxidant activity was assessed by using a DPPH assay and superoxide anion scavenging activity, anti-tyrosinase activity, and anti-proliferative activity were assessed using MTT and lactate dehydrogenase [LDH] assays in vascular smooth muscle cells. The hot-water ($65^{\circ}C$) extract had a higher phenol content than the ethanolic extract. The hot-water extract showed a statistically significant increase in free radical scavenging activity and a greater ability to reduce proliferation of vascular smooth muscle cells stimulated with platelet-derived growth factor-BB. Taken together, hot-water extracts of S. fulvellum may be an important source of antioxidative and antiproliferative agents.

테트라포드를 이용한 S-berm 경사식 방파제의 처오름과 반사 (Wave Run-up and Reflection on Slopes of S-berm Breakwaters Armored with Tetrapods)

  • 안태준;이승협;조용식
    • 한국수자원학회:학술대회논문집
    • /
    • 한국수자원학회 2005년도 학술발표회 논문집
    • /
    • pp.1078-1082
    • /
    • 2005
  • In this study, the run-up height and reflection property on slopes of S-berm and smooth slopes breakwaters are investigated by laboratory experiment. The run-up height analyzed the effect of reflection coefficient, surf similarity parameter. Measured reflection coefficients of smooth slope breakwaters are compared with those of S-berm breakwater with variable widths. In general, measured coefficients of S-berm breakwaters are smaller than those of smooth slope breakwaters.

  • PDF

당귀 및 아위가 평활근 이완과 iNOS 발현에 미치는 영향 (Effects of Radix Angelicae Gigantis and Resina Ferulae on the Relaxation of Smooth Muscle and Expression of iNOS)

  • 김성재;송봉근;이언정;김형균;김중길
    • 대한한의학회지
    • /
    • 제21권2호
    • /
    • pp.60-67
    • /
    • 2000
  • Objectives : Radix Angelicae Gigantis(RAG) and Resina Ferulae(RF) have been used in oriental medicine or folk medicine to increase stamina. The aim of this study was the characterization of the mechanism of action of RAG and RF on smooth muscle and macrophages in rats to find new substances for the treatment of erectile dysfunction, cardiovascular diseases and immune dysfunction. Methods : We investigated the effects of the water extracts of RAG and RF on phenylephrine or KCl-contracted rat endothelium-denuded aorta, the production of NO in vascular smooth muscle cell (VSMC) and the production of NO and induction of iNOS in the $IFN-{\gamma}-primed$ RAW 264.7 cells. Results : The water extracts of the RAG and RF showed significant concentration-dependent relaxation effects on phenylephrine or KCl-contracted rat endothelium-denuded aorta. It also reduced the tension of the rat endothelium denuded aorta which was contracted in $Ca^{2+}-free$ media. On the other hand, it increased production of NO in VSMC which was stimulated with $IL-{\beta}$ or $IL-{\beta}$ plus $IFN-{\gamma}$. The water extracts of RAG and RF increased production of NO and induction of iNOS in the $IFN-{\gamma}-primed$ RAW 264.7 cells. Conclusions : According to the above results, the water extracts of RAG and RF relaxed the smooth muscle effectively and increased the production of NO in VSMC and macrophages. So, these herbs can be applied to erectile dysfunction, hypertension, angina pectoris, artherosclerosis and a defense defect for virus or microbe.

  • PDF

Evaporation of Water in an Aqueous Lithium Bromide Solution flowing over a Horizontal Tube

  • Kim, Dong-Kwan;Kim, Moo-Hwan
    • International Journal of Air-Conditioning and Refrigeration
    • /
    • 제9권3호
    • /
    • pp.57-62
    • /
    • 2001
  • Falling film heat transfer analyses with aqueous lithium bromide solution were performed to investigate the transfer characteristics of the copper tubes. Finned (knurled) tube and a smooth tube were selected as test specimens. Averaged generation fluxes of water and the heat flux were obtained. As the film flow rate of the solution increased, the generation fluxes of water decreased for both tubes due to the fact that the heat transfer resistance increased with the film thickness. The effect of the enlarged surface area at the knurled tube was supposed to be dominant at a small flow rate. The generation fluxes of water increased with the increasing degree of tube wall superheat. Nucleate boiling is supposed to occur at a wall superheat of 20K for a smooth tube, and at 10K for a knurled tube. The increased performance of the knurled tube was supposed to mainly come from the effect of the increased heating surface area.

  • PDF