• 제목/요약/키워드: fluid society

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Audiogram in Response to Stimulation Delivered to Fluid Applied to the External Meatus

  • Geal-Dor, Miriam;Chordekar, Shai;Adelman, Cahtia;Kaufmann-Yehezkely, Michal;Sohmer, Haim
    • Journal of Audiology & Otology
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    • 제24권2호
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    • pp.79-84
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    • 2020
  • Background and Objectives: Hearing can be elicited in response to vibratory stimuli delivered to fluid in the external auditory meatus. To obtain a complete audiogram in subjects with normal hearing in response to pure tone vibratory stimuli delivered to fluid applied to the external meatus. Subjects and Methods: Pure tone vibratory stimuli in the audiometric range from 0.25 to 6.0 kHz were delivered to fluid applied to the external meatus of eight participants with normal hearing (15 dB or better) using a rod attached to a standard clinical bone vibrator. The fluid thresholds obtained were compared to the air conduction (AC), bone conduction (BC; mastoid), and soft tissue conduction (STC; neck) thresholds in the same subjects. Results: Fluid stimulation thresholds were obtained at every frequency in each subject. The fluid and STC (neck) audiograms sloped down at higher frequencies, while the AC and BC audiograms were flat. It is likely that the fluid stimulation audiograms did not involve AC mechanisms or even, possibly, osseous BC mechanisms. Conclusions: The thresholds elicited in response to the fluid in the meatus likely reflect a form of STC and may result from excitation of the inner ear by the vibrations induced in the fluid. The sloping fluid audiograms may reflect transmission pathways that are less effective at higher frequencies.

Audiogram in Response to Stimulation Delivered to Fluid Applied to the External Meatus

  • Geal-Dor, Miriam;Chordekar, Shai;Adelman, Cahtia;Kaufmann-Yehezkely, Michal;Sohmer, Haim
    • 대한청각학회지
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    • 제24권2호
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    • pp.79-84
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    • 2020
  • Background and Objectives: Hearing can be elicited in response to vibratory stimuli delivered to fluid in the external auditory meatus. To obtain a complete audiogram in subjects with normal hearing in response to pure tone vibratory stimuli delivered to fluid applied to the external meatus. Subjects and Methods: Pure tone vibratory stimuli in the audiometric range from 0.25 to 6.0 kHz were delivered to fluid applied to the external meatus of eight participants with normal hearing (15 dB or better) using a rod attached to a standard clinical bone vibrator. The fluid thresholds obtained were compared to the air conduction (AC), bone conduction (BC; mastoid), and soft tissue conduction (STC; neck) thresholds in the same subjects. Results: Fluid stimulation thresholds were obtained at every frequency in each subject. The fluid and STC (neck) audiograms sloped down at higher frequencies, while the AC and BC audiograms were flat. It is likely that the fluid stimulation audiograms did not involve AC mechanisms or even, possibly, osseous BC mechanisms. Conclusions: The thresholds elicited in response to the fluid in the meatus likely reflect a form of STC and may result from excitation of the inner ear by the vibrations induced in the fluid. The sloping fluid audiograms may reflect transmission pathways that are less effective at higher frequencies.

유체요소를 이용한 직사각형 유체 저장구조물의 지진해석 (Seismic Analysis of Rectangular Liquid Storage Structures Ssing Fluid Elements)

  • 김영석;김제민;윤정방
    • 한국해양공학회지
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    • 제6권2호
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    • pp.46-54
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    • 1992
  • In this paper, behavior of rectangular storage structures under earthquake loadings are investigated. Linear sloshing is assumed in this study. The effect of the wall flexibility is considered. Eulerian and lagrangian approaches are presented. The Eulerian approach is carried out by solving the boundary value problem for the fluid motion. In the lagrangian approach, the fluid as well as the storage structure is modelled by the finite element method. The fluid region is discretized by using fluid elements. The (1 $\times$ 1)-reduced integration is carried out for constructing the stiffness matrices of the fluid elements. Seismic analysis of the coupled system is carried out by the response spectra method. The numerical results show that the fluid forces on the wall obtained by two approaches are in good agreements. By including the effect of the wall flexibility, the forces due to fluid motion can be increased very significantly.

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열교환기에 사용되는 얇은 사각 단면 튜브의 고유규진동계수에 대한 이론적 분석 (The Theoretical Investigation of the Natural Frequency Coefficients for a Thin Rectangular Tube used in the Heat Exchanger)

  • 김기만
    • 소음진동
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    • 제5권3호
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    • pp.373-383
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    • 1995
  • From the viewpoint of the structural design, the principal problem of the heat exchanger is the potentiality of structural instabilities due to the fluid loading effect during operations. Excessive fluid loading may give rise to permanent deformation of tube and would enentually result in collapse of heat exchanger, which would cause an obstruction of the fluid flow in the narrow channels. In this study, a fluid-structural interaction model was developed to investigate analtically the vibration characteristics of thin rectangular tube used in the heat exchanger. The model consists of two flat plates separated by fluid. The effects of the fluid in the tube was stuided. For analyses, the natural frequency coefficients of the model were investigated for the plate aspect ratios, channel heights, and boundary conditions. As conclusions, the natural frequency coefficients of the tube is found to be affected largely by the fluid loading and the channel heights.

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Modified TOUGHREACT를 이용한 지중 열교환기 내 순환 유체의 온도 분포 추정 (A Study to Calculate Inlet Fluid Temperature of the Borehole Heat Exchanger (BHE) using Modified TOUGHREACT)

  • 김성균;배광옥;이강근;심병완;송윤호
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2007년도 추계학술대회 논문집
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    • pp.477-480
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    • 2007
  • Inlet fluid temperature of the BRE in the geothermal heat pump system depends on heat exchange rate between the refrigerant of the heat pump and the leaving fluid from the BRE. Because the outlet fluid temperature of the BHE varies with time, inlet fluid temperature has to vary with time. In this study, the module to calculate inlet fluid temperature is developed, which can consider the time-varying outlet fluid temperature and the heat exchange capacity of the heat pump. It is assumed that heat loss or gain of the leaving fluid from outlet to inlet of the BHE is negligible, except when the fluid contacts with the refrigerant of the heat pump. This module is combined with TOUGHREACT, a widely accepted three-dimensional numerical simulator for heat and water flow and geochemical reactions in geothermal systems and is applied to data analyses of the thermal response test.

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