• Title/Summary/Keyword: active pressure

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Effect of a Magnetic Field on Thermal Conductivity of Partially Ionized Gases

  • Yun, Hong-Sik
    • Journal of The Korean Astronomical Society
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    • v.9 no.1
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    • pp.1-6
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    • 1976
  • The translational and reactive parts of thermal conductivity of a partially ionized solar magneto-plasma gas have been calculated based on Yun and Wyller's formulation (1972) along with Devoto's theory(1968). The computed results are presented as functions of temperature and pressure for given magnetic field strengths. The results of the calculations show that for most photospheric conditions the magnetic field does not play any important role in characterizing thermal properties of the ionized gas. However, when the gas pressure is low(e.g., P<10 dynes/$cm^2)$) the field becomes extremely effective even if its strength is quite small (e.g., B<0.1 gauss). The reactive part of the thermal transport is found to be very important when the gas is undertaking active ionization.

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New 3D failure analysis of water-filled karst cave beneath deep tunnel

  • Zhang, R.;Yang, X.L.
    • Geomechanics and Engineering
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    • v.18 no.1
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    • pp.1-9
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    • 2019
  • In this study, both 2D and 3D failure shapes of rock mass above the water-filled cavity are put forward when the surrounding rock mass cannot bear the pressure caused by the water-filled cavity. Based on the analytical expressions derived by kinematic approach, the profiles of active and passive failure patterns are plotted. The sensitivity analysis is conducted to explore the influences of different rock parameters on the failure profiles. During the excavation of the deep tunnels above the karst cavity, the water table always changes because of progressive failure of cavity roof. Therefore, it is meaningful to discuss the effects of varying water level on the failure patterns of horizontal rock layers. The changing laws of the scope of the failure pattern obtained in this work show good consistency with the fact, which could be used to provide a guide in engineering.

Multiuser Detection of Electric Scooter Using Tilt and Pressure Sensors (기울기 센서와 압력 센서를 이용한 전동 킥보드용 다인승 감지 방안)

  • Moonjeong Ahn;Jia Kim;Jihoon Lee
    • Journal of the Semiconductor & Display Technology
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    • v.23 no.2
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    • pp.28-32
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    • 2024
  • The personal mobility Sharing service is currently active. Especially, electric scooters are widely utilized because they can move comfortably at a high speed over a short distance with a simple driving method. Its driving method is easy, but there is no protection device to protect the bare body. So, there is a greater accident than other means of transportation, and if two people are on board, there is higher accident probability. However, since there is no specific ways to prevent multi-person boarding yet, we propose a multi-person boarding detection model using tilt and pressure sensor. The proposed method measures the tilt degree and direction by using a tilt sensor installed in the center of the board plate and detects multi-people riding.

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Nanoscale Metal Powders Production and Applications

  • Gunther, Bernd-H
    • Journal of Powder Materials
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    • v.9 no.6
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    • pp.409-415
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    • 2002
  • In this review the methods for production and processing of isolated or agglomerated nanoscale metal particles embedded in organic liquids (nanosuspensions) and polymer matrix composites are elucidated. Emphasis is laid on the techniques of inert gas condensation (IGC) and high pressure sputtering for obtaining highly porous metal powders ("nanopowder") as well as on vacuum evaporation on running liquids for obtaining nanosuspensions. Functional properties and post-processing are outlined in view of applications in the fields of electrically conductive adhesives and anti-microbially active materials for medical articles and consumer goods.mer goods.

A Study on the Active Noise Control Algorithm for Rreducing the Computation Rime (계산속도를 증가시키기 위한 능동소음제어 알고리즘에 대한 연구)

  • 박광수;박영진
    • 제어로봇시스템학회:학술대회논문집
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    • 1993.10a
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    • pp.699-703
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    • 1993
  • When the error path can be modeled as a pure delay, an adaptive algorithm for slowly time varying system is proposed to minimize the sound pressure level. This algorithm makes it possible to use the fittered-x LMS algorithm with on-line delay modeling of the error path. Another simple adaptive algorithm for pure tone noise is proposed which eliminates the cross term in the multiple error filtered-x LMS algorithm.

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Transport Coefficients across Charged Mosaic Membrane

  • Yang, Wong-Kang
    • Bulletin of the Korean Chemical Society
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    • v.25 no.5
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    • pp.665-667
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    • 2004
  • In previous studies, charged mosaic membranes having two different fixed charges in the membrane matrix indicated unique transport behavior such as preferential material transport. In this study, the composite charged mosaic membrane endurable to mechanical pressure in practical application was investigated from the same aspect of solute and solvent transport as before. Lp and ${\omega}$ estimated by taking account of active layer thickness were satisfactorily consistent with those in mosaic membrane without reinforcement. On the other hand, the reflection coefficient s indicated the negative value that suggests preferential material transport.

A Theological Study on the Karst Water

  • Kim, Choo-Yoon
    • Journal of the Speleological Society of Korea
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    • no.65
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    • pp.31-37
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    • 2004
  • Karst water was defined as 'Water which fills the cavities of the earth continuously and is only subject to gravity and hydraulic pressure.' Karst springs are water outlets from karst-hydrologically active cavities in water-soluble rocks, whether they are on the surface or within the earth. Karst springs behave so differently that the general principles of classification for all springs can be applied to them with a few exceptions. Firstly, classification according to the outflow: perennial springs, periodic springs, rhythemically springs, episodically flowing spring. Secondly, classification according to geologic and tectonic conditions: bedding springs, fracture springs, overflow spring, ascending spring.

A Review of Airway Clearance Technique (기도청결 기법(Airway Clearance Technique)에 관한 고찰)

  • Kim Kyoung
    • The Journal of Korean Physical Therapy
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    • v.16 no.1
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    • pp.1-13
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    • 2004
  • Airway clearance technique are used to aid in mucus clearance in a variety of disease states. In this review I discuss airway physiology including airway mucus, action of airways, and airway resistance and review the literature and theory regarding forced expiratory technique, active cycle of breathing technique, and autogenic drainage. Also, I look at the appropriate device such as positive expiratory pressure mask(PEP mask), Flutter, and HFCWO(Vest system) which can be applied in the field of respiratory physical therapy. This study is provided as the basic resource regarding the application method of respiratory physical therapy.

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BLEEDING & INFECTION CONTROL BY THE PACKING AND DRAINAGE ON BLEEDING EXTRACTION SOCKET BEFORE BONE MARROW TRANSPLANTATION IN A MULTIPLE DISABLED PATIENT WITH ANTICOAGULATION DRUG : REPORT OF A CASE (항응고제 투여중인 다발성 장애환자에서 골수이식전 발치창 출혈부의 전색과 배농술을 통한 출혈과 감염의 조절 : 증례보고)

  • Yoo, Jae-Ha;Son, Jeong-Seog;Kim, Jong-Bae
    • The Journal of Korea Assosiation for Disability and Oral Health
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    • v.8 no.1
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    • pp.15-21
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    • 2012
  • Extraction of all nonrestorable teeth prior to bone marrow transplantation is the major dental management of the patient being prepared for the transplantation. But, there are four principal causes for excessive bleeding in the immediate postextraction phase ; (1) Vascular wall alteration (wound infection, scurvy, chemicals, allergy) (2) Disorders of platelet function (3) Thrombocytopenic purpuras (4) Disorders of coagulation (liver disease, anticoagulation drug-heparin, coumarin, aspirin, plavix) If the hemorrhage from postextraction wound is unusually aggressive, the socket must be packed with local hemostatic agent and wound closure & pressure dressing are applied. But, in dental alveoli, local hemostatic agent (gelfoam, surgcel etc) may absorb oral microorganisms and cause alveolar osteitis (infection). This is a case report of bleeding and infection control by suture, pressure packing and iodoform gauze drainage on infected active bleeding extraction socket under sedation and local anesthesia in a 57-years-old multiple disabled patient with anticoagulation drug.

Intrinsic Flux Inequality in Forward Osmosis (FO) and Pressure-Retarded Osmosis (PRO) Processes (수학적 귀납법을 이용한 정삼투 및 압력지연삼투 공정의 투과율 불균형 해석)

  • Kim, Albert S.;Lee, Seung-won
    • Membrane Journal
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    • v.25 no.4
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    • pp.367-372
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    • 2015
  • In pressure-retarded osmosis (PRO) and forward osmosis (FO) processes, solvent (permeate) flux depends on which surface the draw solution faces. There are two operation modes. PRO mode indicates that the active layer faces the draw solution, and FO mode means that the porous substrate fronts the draw stream. It is often observed that the PRO mode produces higher flux than that of FO under the same operating conditions. The current work uses the method of proof by contradiction, and mathematically proves the intrinsic flux inequality between the two modes.