• Title/Summary/Keyword: water movement

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Numerical investigation of floating breakwater movement using SPH method

  • Najafi-Jilani, A.;Rezaie-Mazyak, A.
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.3 no.2
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    • pp.122-125
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    • 2011
  • In this work, the movement pattern of a floating breakwater is numerically analyzed using Smoothed Particle Hydrodynamic (SPH) method as a Lagrangian scheme. At the seaside, the regular incident waves with varying height and period were considered as the dynamic free surface boundary conditions. The smooth and impermeable beach slope was defined as the bottom boundary condition. The effects of various boundary conditions such as incident wave characteristics, beach slope, and water depth on the movement of the floating body were studied. The numerical results are in good agreement with the available experimental data in the literature The results of the movement of the floating body were used to determine the transmitted wave height at the corresponding boundary conditions.

The Evaluation of Performance of C-11 Radio Isotope Gas Target using Finite Element Method (FEM을 이용한 C-11 동위원소 기체표적의 성능평가)

  • Oh, Hwan-Sup;Hur, Min-Goo;Park, Sang-Pil;Jung, Hyo-Jin
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.15 no.3
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    • pp.24-31
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    • 2006
  • The energy degrader is the most fragile part of the security of a target, has been newly designed to improve the performance of the gas target. Also, the numerical analysis of the heat movement and mechanical movement during the operation of the target has been accomplished. The heat analysis and structure analysis which are using the cooling water flow and pressure in the energy degrader and the finite element analysis program, has been considered with the heat movement and mechanical movement according to the current capacity of proton beam which determines the production yield of the radioactive isotope. Also the possible use range has been determined and at the same time the most suitable running condition according to the current capacity of proton beam has been suggested.

Method of Reducing Lateral Displacement of Abutment Constructed on Marine Clay Deposits (해안 연약지반상의 교량 구조물 변위 억제)

  • 장용채
    • Journal of Korean Port Research
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    • v.12 no.2
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    • pp.337-348
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    • 1998
  • Since 1970s, though many effective construction methods have been established to solve soft ground problems which had occurred in the off shore land reclamation and on shore highway construction, lateral movement of structure on soft ground is still a big problem to engineers. In this study an applicability of criteria for determining the lateral movement of the structure in soft ground is examined and most measured data is obtained from 140 bridge abutments in highway construction sites. Characteristics and effectiveness of existing methods that used for deciding amount of lateral movements of abutment are analyzed using the obtained data. From the analysis, a proper method to prevent lateral movement is proposed. This method is confirmed on several case histories which were constructed on marine clay.

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The studies of actual condition and therapeutic effects of hot spring water in Korea (우리나라 온천의 실태와 치료적 효과에 관한 연구)

  • Park Rae-Joon
    • The Journal of Korean Physical Therapy
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    • v.12 no.3
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    • pp.369-377
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    • 2000
  • Hot spring water is petrifaction water and mixed with animals and plants disintegrated water in the underground. The ingredient are complicated and abundant. The contained element is used to facilitate the function of human body. activate the human structure movement. discharge waste material due to increase circulation and metabolism, also it can remain the homeostasis. We can not find research for spa therapy in our country. We use to drink and bath in the hot spring water bue don't have rehabilitation facilities

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The momentary movement of soft contact lens by blinking : The change of movement depending on wearing time (손목에 의한 소프트콘택트렌즈의 순간적인 움직임 : 착용시간의 증가에 따른 움직임의 변화)

  • Park, Sang-Il;Lee, Youn Jin;Lee, Heum-Sook;Park, Mijung
    • Journal of Korean Ophthalmic Optics Society
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    • v.12 no.1
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    • pp.1-7
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    • 2007
  • To investigate the momentary movement pattern of soft contact lens(SCL) depending on wearing time, eight types of soft contact lenses were worn by 10 normal subjects and the momentary movements of SCLs were estimated using by high speed camera(FASTCAM ultima 1024). When the momentary movements of SCLs in the cornea between blinkings were compared after 15 min wearing, the vertical movements of all eight SCLs were about 2 times larger than the horizontal movement but the extent of these movement difference was a function of kinds of SCLs. The momentary moving distance of SCL varied from the kinds of SCLs, which A and B lens, daily wear lens, moved significantly larger distance compared with other SCLs. The momentary movements between blinkings decreased significantly after 8hr wear of SCLs. The extents were different when SCLs were compared with each other, which the reduction range of horizontal and vertical movement was 24.6~60.0% and 20.4~94.3%, respectively. The A, B and C lenses which had relatively higher water content showed the larger movement reduction after SCL wear. This results suggest that wearing SCL for some hours decreases the movement of SCl, which can induce the change of tear flow.

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A Study on the Sediment Movement Using Numerical Models (수치모형을 이용한 하상변동 연구)

  • Im, Chang-Su;Son, Gwang-Ik;Lee, Jae-Jun;Yun, Se-Ui
    • Journal of Korea Water Resources Association
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    • v.32 no.2
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    • pp.131-142
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    • 1999
  • In this study, one and semi-two dimensional numerical models were applied to study on the hydraulic and sedimentologic characteristics of upstream and downstream channel section near the Buyeo intake towers. The HEC-6 model was applied for the simulation of one dimensional sediment movement from 1988 to 1996, and GSTARS model was applied for the simulation of semi-two dimensional sediment movement for the same period. After the verification of accuracy of HEC-6 and GSTARS models, the models were applied again to predict the sediment movement near intake towers from 1988 to 2001. In this case, measured channel section of 1988 was used as an initial channel condition, and used to predict the long-term variation of channel section of 2001 after 13 years since 1988. The simulation results show that the channel bed is sedimented and eroded repeatedly in the main channel of overall study area, and that channel bed is getting elevated in the near Buyeo intake towers.

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A Study on an Analysis and Design of the Internal Structure of Heumgyeonggak-nu

  • Kim, Sang Hyuk;Yun, Yong-Hyun;Ham, Seon Young;Mihn, Byeong-Hee;Ki, Ho-Chul;Yoon, Myung-Kyoon
    • Journal of Astronomy and Space Sciences
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    • v.34 no.2
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    • pp.171-182
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    • 2017
  • In this study, the internal structure of a Heumgyeonggak-nu (欽敬閣漏) was designed, and the power transmission mechanism was analyzed. Heumgyeonggak-nu is an automated water clock from the Joseon Dynasty that was installed within Heumgyeonggak (欽敬閣), and it was manufactured in the $20^{th}$ year of the reign of King Sejong (1438). As descriptions of Heumgyeonggak-nu in ancient literature have mostly focused on its external shape, the study of its internal mechanism has been difficult. A detailed analysis of the literature record on Heumgyeonggak-nu (e.g., The Annals of the Joseon Dynasty) indicates that Heumgyeonggak-nu had a three-stage water clock, included a waterfall or tilting vessel (欹器) using the overflowed water, and displayed the time using a ball. In this study, the Cheonhyeong apparatus, water wheel, scoop, and various mechanism wheels were designed so that 16 fixed-type scoops could operate at a constant speed for the water wheel with a diameter of 100 cm. As the scoop can contain 1.25 l of water and the water wheel rotates 61 times a day, a total of 1,220 l of water is required. Also, the power gear wheel was designed as a 366-tooth gear, which supported the operation of the time signal gear wheel. To implement the movement of stars on the celestial sphere, the rotation ratio of the celestial gear wheel to the diurnal motion gear ring was set to 366:365. In addition, to operate the sun movement apparatus on the ecliptic, a gear device was installed on the South Pole axis. It is expected that the results of this study can be used for the manufacture and restoration of the operation model of Heumgyeonggak-nu.

The Roles and Meanings of Environmental Conflict and Movement in Rural Region : A Case Study on Organic Farming Movement at Paldang Region, Yangpyung-gun (농촌지역 환경갈등과 농촌주민 환경운동의 역할과 의미 : 양평군 팔당지역 유기농업운동을 사례로)

  • Lee, Young-Min;Hur, Nam-Hyuk
    • Journal of the Korean association of regional geographers
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    • v.7 no.4
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    • pp.18-32
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    • 2001
  • Korean society has frequently seen the conflicts between environmentally oriented ideology and development ideology which generally take shape as regional problems. An interesting example is the case of Paldang water resource protection area in Yangpyung-kun, Kyunggi Province. At the area, the rural residents are trying to take regional development by utilizing as much as natural resource in the region, and the central government is trying to make clean water sustained for the public interest of the whole people living within the supplying area of the water resource. Accordingly, the conflict is inevitable. It is the role of environmental movement group that makes us pay attention to this region. Under the present situation regarding environmental protection as a core keyword, the environmental protection groups tend to stand on the side of the central government. That is, those groups let the government consolidate its dominance discourse, which help the resistance discourse of the residents weakened. This basic structure of relationship sometimes touches off the situations of antagonistic confrontation. It is the group for organic fanning movement on the region that is playing a significant mediating role between the two. It has eased severe confrontation, and has persuaded the residents, expecially the farmers, to accept so-called win-win strategies which are related with various kind of organic fanning. The agriculture can be regarded as a win-win action because it is a way of fanning adapted to the protected natural environment. It is taking firm hold in this region as an alternative which can satisfy the ideology of 'sustainable development' or 'sustainability'. It could give us a kind of paradoxical confusion that the strategies of regional development of pro-environment are being carried out in the region where the residents are fighting against the government's strict control of natural environment. The example of this region, however, could show a significant direction for solving the continuous problem of conflict between environmental protection and regional development.

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The Characteristics of Flow and Movement of Floc in the Sedimintation Basin (침전지내 흐름 및 플럭의 이동 특성에 관한 연구)

  • Choe, Gye-Un;Kim, Jeong-Hyeon;Lee, Myeon-Ju
    • Journal of Korea Water Resources Association
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    • v.32 no.2
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    • pp.177-184
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    • 1999
  • In this paper, the characteristics of the flow and the movement of the floc were analyzed through the experiments in the sedimentation basin using the redioisotope. Tc-99m radioisotope was used for the experiments for the characteristics of the flow, and the bentonite absorbing Tc-99m radioisotope was used in the experiments for the movement of the floc. Through the experiments of the flow, it was found that the velocities of flow in the sedimentation basin were different depending upon the position and the depth. The distance of the moving trajectories of the floc is increased by increasing the discharge. By increasing the discharge, the settling point is farther from the inlet, and the turbidity removal efficiencies in the sedimentation basin are decreased. The moving velocities of the floc and the density are changed in the different depths in the sedimentation basin.

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