• Journal of Ecology and Environment
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• 제29권2호
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• pp.175-183
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• 2006

The discovery of deep-sea hydrothermal vents and their ecosystems is a monumental landmark in the history of Ocean Sciences. Deep-sea hydrothermal vents are scattered along the global mid-ocean ridges and back-arc basins. Under sea volcanic phenomena related to underlying magma activities along mid-ocean ridges generate extreme habitats for highly specialized communities of animals. Multidisciplinary research efforts during past three decades since the first discovery of hydrothermal vents along the Galapagos Rift in 1977 revealed fundamental components of physiology, ecology, and evolution of specialized vent communities of micro and macro fauna. Heterogeneous regional geological settings and tectonic plate history have been considered as important geophysical and evolutionary factors for current patterns of taxonomic composition and distribution of vent faunas among venting sites in the World Ocean basins. It was found that these communities are based on primary production of chemosynthetic bacteria which directly utilize reduced compounds, mostly $H_2S$ and $CH_4$, mixed in vent fluids. Symbioses between these bacteria and their hosts, vent invertebrates, are foundation of the vent ecosystem. Gene flow and population genetic studies in parallel with larval biology began to unveil hidden dispersal barrier under deep sea as well as various dispersal characteristics cross taxa. Comparative molecular phylogenetics of vent animals revealed that vent faunas are closely related to those of cold-water seeps in general. In perspective additional interesting discoveries are anticipated particularly with further refined and expanded studies aided by new instrumental technologies.

• 한국화재소방학회논문지
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• 제22권4호
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• pp.1-10
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• 2008

본 연구에서는 미국 NFPA 204 기준에 의해 설계된 수직 배연구에 대하여 배연구의 위치, 외기 온도, 풍속 및 화재크기가 자연배연 성능에 미치는 영향과 화재특성을 CFAST 프로그램을 사용하여 수치 해석적으로 조사하였다. 배연구는 외벽의 최고 상부에 위치한 경우와 외기온도가 낮은 경우 및 풍속이 작은 경우 배연성능기준을 만족하였다. 또 화재크기가 클수록 배출량은 증가하나 연기층 높이는 낮아져 배연성능기준을 만족하지 못하였다. 직접 외기와 통하는 수직 자연배연구의 설계시 해당지역의 최고 온도와 최대 풍속을 고려하고, 설계화재를 정확히 결정하여 배연성능기준이 만족되도록 주의가 요망된다.

• 한국신뢰성학회지:신뢰성응용연구
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• 제13권1호
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• pp.45-53
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• 2013

In this paper, we analyze the failure mechanism of the washer pump to find what is the failure cause in the road environment. The statistics show the field common failure mode is inner corrosion. The failure mechanism is assumed that the inner part of washer pump is corroded due to inflow of moisture through vent hole. To prevent the failure, we can think a method that is covering the vent hole. In general, the vent hole is designed to play an important role in an automobile parts. So, we need to prove the vent hole is not necessary. The first purpose of this paper is to make sure that the vent hole does not affect the durability of washer pump using the analysis of operating condition. The second purpose is to compare the durability properties if the vent hole is covered.

• 한국가스학회지
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• 제16권4호
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• pp.59-64
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• 2012

LPG 저장설비에 부착된 압력방출밸브 방출관으로부터 분출된 가스의 확산에 대해 검토하였다. 통상 방출관은 안전한 장소인 수직 상방향으로 분출되도록 설치되어야 하며, 방출된 가스가 착화되더라도 저장탱크, 장치, 배관에 화염이 닿지 않도록 설치되어야 한다[1][2]. 그러나 우리나라에서는 방출구를 통한 분출방향에 대한 기준이 없이 다양한 방출구 형태가 존재한다. 따라서, 본 연구에서는 4가지 방출방향 즉 수직상방, 수직하방, 수평 2, 수직 4방향에 대해서 고려하였다. 방출구로부터 분출된 가스의 확산 시뮬레이션은 상용소프트웨어인 FLACS를 사용하였다. 이를 통해 수직하방, 수평 2, 수직 4방향으로 분출하도록 방출구를 설치하는 것은 지면에서의 착화를 방지하는 데 불리한 것으로 나타났다. 따라서 안전밸브로부터 분출된 가스를 방출구를 통해 안전하게 분출하기 위해서는 수직상방으로 분출되는 것이 최선임을 알 수 있었다.

• 한국정밀공학회지
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• 제31권8호
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• pp.659-663
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• 2014

Manufacturing processes of industrial tire are composed of mixing, extrusion, curing, trimming and inspecting. Among them curing is the most important process in the production of industrial tire. In this study the newly developed spring vent system was designed in order to solve rubber intrusion problem inside spring vent system in the curing process. After the experiment it is concluded that rubber intrusion was caused by angled stem head part. New spring vent system was manufactured and new design of spring vent system is proper to use for industrial tire curing process.

• 설비공학논문집
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• 제14권3호
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• pp.247-253
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• 2002

In this study, reduced-scale experiments were conducted to analyze smoke movement in tunnel fire with roof vent. The 1/20 scale experiments were carried out under the Froude scaling using gasoline pool fire ranging from 7.3 to 15.4 cm in diameter with total heat release rate from 1.0 to 8.46kw. In case of 1 m high vent, smoke front reached to the tunnel exit at about 16 sec delayed with ventilation. The delay time grew longer with the vent height. The temperature after the vent was lower than that without the vent. The exit temperature declined maximum of $20^{\circ}C$ after passing the vent. It was confirmed that the thickness of smoke layer was maintained uniformly under the 25% height of the tunnel through the visualized smoke now by a laser sheet and the digital camcorder.

• 대한치과보철학회지
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• 제32권1호
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• pp.171-178
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• 1994

This paper reports histologic and histomorphometric results concerning bone healing around vent area of 16 titanium plasma sprayed IMZ implants in rabbit femurs. Bone contact around the implants 8 weeks after placement showed a great deal of variability from 14.32% to 65.94% and mean total bone contact was 33.96%. The mean percent amount of bone contact was 43.68% in inner surface of vent and 27.79% in outer surface. Histologic examination of horizontal sections of vent area showed direct contact with living lamellar bone and some woven bone. The implants surface area not in contact with bone was in contact with collagenous connective tissue. But there was no sign of foreign-body reaction.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.383-384
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• 2006

Ventilated disc was improved for reducing judder and heat. But the crack among vent holes occurs due to stress concentration. We investigate the stress distribution of vent holes. The vent holes with shape of a right angle, a chamfer and rounding was analyzed. The result of FEA was that rounded vent holes have a minimum stress. Also Maximum stress distributed within holes. Therefore We suggest that the rounded vent holes is good to reduce the crack.

• 한국가시화정보학회지
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• 제8권1호
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• pp.25-30
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• 2010

The flow characteristics under recirculation cool vent mode is numerically studied using commercial fluid dynamic code(CFX). For the reliable analysis, real vehicle and human FE model is employed in grid generation process. The geometrical location and shape of panel vent, and exhaust vent is set as that of real vehicle model. The flowrate of the working fluid is determined as 330CMH which is equivalent to 70 percent of maximum capacity of HVAC system. The high velocity regions are formed around 4 each panel vent. Because of the non-symmetrically located exhaust, non-uniform flow and partial backflow near the door trim is observed. Streaklines start from each panel vent show the flow pattern of the airflow in the passenger's compartment very well.

• 대한치과보철학회지
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• 제23권1호
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• pp.145-154
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• 1985

To study the effect of the vent and dense surface of the phophate-bonded investment on the castability of a non-precious alloy used in PFM restoration, one-ended polypropylene straw patterns of 0.15mm thick, 5mm radius. 10mm-high were cast with Vera Bond. The following results were obtained. 1. Thin patterns could be cast completely with a non-precious alloy. 2. No difference in the castability was found among the patterns with vent, chill vent and with out vent. 3. Dense surface of the phosphate-bonded investment had no effect on the cast ability of a nonprecious alloy.