• Title/Summary/Keyword: radial

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A Discretization Method Via a Radial-Exponential Scheme in the Cylindrical Coordinate (원통좌표계에서 반경지수도식에 의한 이산화방법)

  • Kim, Charn-Jung
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.24 no.5
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    • pp.694-698
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    • 2000
  • In the cylindrical coordinate, the origin r = 0 plays a role of the singularity and thus much care is needed to treat near-origin region. This work presents a new numerical scheme which is derived from the exact solution under the one-dimensional assumption in the radial direction. It is shown that the near-origin region can be properly treated by the radial-exponential scheme, whereas the numerical results from the conventional exponential scheme deviate considerably from the exact solution. Over the region of small ($ {\delta}r_e/r_e$ the present radial-exponential scheme turns out to be almost the same as the exponential scheme.

Radial Penetration of Safranine in Populus tomentiglandulosa T. Lee

  • Ahmed, Sheikh Ali;Chae, Soo-Nam;Chun, Su-Kyoung
    • Journal of the Korea Furniture Society
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    • v.18 no.3
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    • pp.243-247
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    • 2007
  • An experiment was conducted to observe the safranine penetration depth in radial directions of Populus tomentiglandulosa. Radial penetration was considered from bark to pith. In radial direction, ray parenchyma and intercellular space were considered for the measurement of safranine penetration depth. It was found that sapwood conducted safranine 24.23% higher in radial direction compared with heartwood. Intercellular space conducted safranine 39.27% higher depth compared with ray parenchyma and the penetration depth was 39.41% higher in sapwood compared to heartwood. During safranine penetration, it formed a curvature in the lumen of ray parenchyma. Initially safranine penetration was found high and decreased gradually.

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An Experimental Study on the Flame Localization Characteristics and Pulsating Instability in a Radial Multi-channel (반경방향 다중 채널 내 예혼합 화염의 안정화 특성과 맥동 불안정성에 관한 실험적 연구)

  • Lee, Dae Keun;Ko, Chang-Bog
    • 한국연소학회:학술대회논문집
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    • 2013.06a
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    • pp.41-43
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    • 2013
  • In order to simulate and visually observe combustion phenomena in cylindrical radial-flow porous inert media, a radial multi-channel burner, made of transparent quartz plates, was fabricated. Flame stabilization characteristics and its pulsating instability in the burner were experimentally investigated with respect to various mixture flow rates and equivalence ratio. As a result, five different flame behaviors, such as stable flame, pulsating instability, sudden extinction, blowout and unstable extinction, were observed. Mean radial position of circularly arranged multi-flame and its averaged burning velocity were measured and then compared to the freely propagating flame. The multi-flame pulsation frequency is about several tens of Hz and it is supposed to be generated by the heat diffusion enhancement to cold pre-mixture by the intensive gas-solid interaction.

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Design and Analysis of Double Stator Type Bearingless Switched Reluctance Motor (이중고정자구조를 가지는 베어링리스 스위치드 릴럭턴스 전동기의 설계와 해석)

  • Peng, Wei;Lee, Dong-Hee;Ahn, Jin-Woo
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.60 no.4
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    • pp.746-752
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    • 2011
  • In this paper, a novel bearingless switched reluctance motor (BLSRM) with double stator is proposed. This motor has two stators. Torque stator is outside, which mainly produces rotational torque. Radial force stator is inside, which mainly generates radial force to suspend the rotor. A novel structure and operating principle are presented. And characteristics of the proposed structure such as magnetic flux distribution, inductance, torque and radial force are analyzed through finite element method. From the analysis, the proposed BLSRM has linear characteristic of radial force and independence from torque current.

Harvesting of Radial Artery With Harmonic Scalpel (Harmonic Scalpel을 이용한 요골동맥의 적출)

  • 이현성;강정한;최성실;장병철
    • Journal of Chest Surgery
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    • v.34 no.6
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    • pp.499-501
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    • 2001
  • In the 1970s, the radial artery was proposed as a coronary artery bypass graft but then was abandoned due to graft occlusion secondary to spasm during harvesting. Development of new pharmacologic antispasmodic agents and minimal traumatic harvesting techniques has led to the revival of the use of the radial artery in coronary artery bypass procedures. Harmonic Scalpel(Ultracision Inc, Smithfield, Rl) offers the surgeon the ability to perform less traumatic, spasm free, and rapid radial artery harvesting.

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Successful transradial intervention via a radial recurrent artery branch from the radioulnar alpha loop using a sheathless guiding catheter

  • Yoon, Shin-Eui;Park, Sangwook;Ahn, Sung Gyun
    • Journal of Yeungnam Medical Science
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    • v.35 no.1
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    • pp.94-98
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    • 2018
  • The radial artery is generally the preferred access route in coronary angiography and coronary intervention. However, small size, spasm, and anatomical variations concerning the radial artery are major limitations of transradial coronary intervention (TRI). We describe a successful case involving a patient with coronary artery disease who underwent TRI via a well-developed radial recurrent artery branch from the radioulnar alpha loop using a sheathless guiding catheter.

In-Plane Natural Vibration Analysis of a Rotating Annular Disk (회전하는 환상 디스크의 면내 고유진동 해석)

  • Kim, Chang-Boo;Song, Seung-Gwan
    • Proceedings of the KSR Conference
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    • 2008.11b
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    • pp.1379-1388
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    • 2008
  • In this paper, we present the equations of motion by which the natural vibration of a rotating annular disk can be accurately analyzed. These equations are derived from the theory of finite deformation and the principle of virtual work. The radial displacements of annular disk which is rotating at constant angular velocity are determined by non-linear equations formulated using 1-dimensional finite elements in radial direction. The equations of the in-plane vibrations at disturbed state are also formulated using 1-dimensional finite elements in radial direction along the number of nodal diameters. They are expressed as in functions of the radial displacements at the steady state and the disturbed displacements about the steady state. In-plane static deformation modes of the annular disk are used as the interpolation functions of 1-dimensional finite elements in radial direction. The natural vibrations of an annular disk with different boundary conditions are analyzed by using the presented model and the 3-dimensional finite element model to verify accuracy of the presented equations of motion. Its results are compared and discussed.

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Vibration Analysis for the Defective Ball Bearing under Radial Loads (반경하중을 받고있는 결함 볼베어링의 진동분석)

  • Kang, Byoung-Yong;Lee, Woo-Seop;Chang, Ho-Gyeong;Kim, Ye-Hyun
    • The Journal of the Acoustical Society of Korea
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    • v.16 no.4
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    • pp.21-28
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    • 1997
  • In this study, comparison between Harris-theoretical values and experimental data of load-deflection characteristics in bearing was made. The experiments are conducted under the conditions of the various radial loads and speed of shaft. In the case of non-defective ball bearing, the experimental data agreed well with the Harris-theoretical values for the small steady radial load but not for the large steady radial load. For the radial load bearing, the experimental results show that the stiffness of bearing at the single and multiple defective bearing are bigger in the radial defectiion than in the axial deflection. Load-deflection characteristics for the bearing defect part make it possible to detect the presence of a defect in bearing.

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Point interpolation method based on local residual formulation using radial basis functions

  • Liu, G.R.;Yan, L.;Wang, J.G.;Gu, Y.T.
    • Structural Engineering and Mechanics
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    • v.14 no.6
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    • pp.713-732
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    • 2002
  • A local radial point interpolation method (LRPIM) based on local residual formulation is presented and applied to solid mechanics in this paper. In LRPIM, the trial function is constructed by the radial point interpolation method (PIM) and establishes discrete equations through a local residual formulation, which can be carried out nodes by nodes. Therefore, element connectivity for trial function and background mesh for integration is not necessary. Radial PIM is used for interpolation so that singularity in polynomial PIM may be avoided. Essential boundary conditions can be imposed by a straightforward and effective manner due to its Delta properties. Moreover, the approximation quality of the radial PIM is evaluated by the surface fitting of given functions. Numerical performance for this LRPIM method is further studied through several numerical examples of solid mechanics.

The Effect of Sa-Am Stomach Tonifying Acupuncture on Radial Pulse in Healthy Human Subjects (위정격(胃正格) 자침이 정상 성인의 맥파(脈波)에 미치는 영향)

  • Choi, Joo Young;Kang, Jae Hui;Yim, Yun Kyong;Lee, Hyun
    • Journal of Acupuncture Research
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    • v.29 no.6
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    • pp.57-71
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    • 2012
  • Objectives : The purpose of this study is to find the effects of Sa-Am stomach tonifying acupuncture on radial pulse through the parameters difference. Methods : Forty healthy subjects participated in this study, acupuncture group and control group were divided. Radial pulse were measured using 3 dimensional pulse imaging system(DMP-3000). 19 parameters that significantly changed were selected after comparing between acupuncture group and control group. Then, 19 parameters were analyzed before, immediately after, 30 minutes after and 60 minutes after acupuncture in acupucture group. Results : 1. Heart rate, pulse period, T/T1, T2/T, T4/T, T5/T, T-T4, (T-T4)/T and T4/(T-T4) significantly changed after acupuncture. 2. H1 Amplitude, H2 Amplitude, H4 Amplitude and H5 Amplitude significantly changed after acupuncture. 3. Area of Pulse Wave, Systolic Pulse Area, Diastolic Pulse Area and Area of W significantly changed after acupuncture. 4. AIx/HR significantly changed after acupuncture. Conclusion : Stomach Tonifying Acupuncture exerts an influence on radial pulse parameters. Further radial pulse change study on various acupuncture treatment is required.