• Title/Summary/Keyword: Waves on Cell

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A Study On the Cooling Effect of the Floating Horizontal Solar Cell

  • Jae-hyuk Lee
    • International journal of advanced smart convergence
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    • v.12 no.2
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    • pp.182-186
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    • 2023
  • In this study, we measured the power and temperature of the floating horizontal solar cell in a coastal lagoon and compared with those of ground solar cell and water platform solar cell. Because the bottom surface of the floating horizontal solar cell was contacting the water, cooling effect was expected stronger than other cells. As a result of the measurement, the power of floating horizontal cell was 11.7% higher than that of the ground cell and 15% higher than that of the water platform cell. During the measurement, it was observed that water waves were continuously flowed on the top surface of floating horizontal cell by the wind, and it could be assumed that the cooling effect occurred not only on the bottom surface of the cell but also on the top surface. In order to analyze the cooling effect and power increasing of the horizontal cell in the wave situation, we measured power and temperature of the cell while generating artificial waves in a laboratory equipped with Zenon lamp as a solar simulator. At the height of thewater surface, the power of the cell with waves was 3.7% higherthan without waves and temperature was 4.6℃ lower. At 1 cm and 2 cm below the watersurface, power of the cell with waves was decreased by 14% and 11% than without waves while temperature was same . At 3 cm below the water surface, there was no effect of waves.

Update on the Effects of Sound Wave on Plants

  • Chowdhury, Md. Emran Khan;Lim, Hyoun-Sub;Bae, Hanhong
    • Research in Plant Disease
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    • v.20 no.1
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    • pp.1-7
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    • 2014
  • Plant growth is considered the sum of cell proliferation and subsequent elongation of the cells. The continuous proliferation and elongation of plant cells are vital to the production of new organs, which have a significant impact on overall plant growth. Accordingly, the relationship between environmental stimuli, such as temperature, light, wind, and sound waves to plant growth is of great interest in studies of plant development. Sound waves can have negative or positive effects on plant growth. In this review paper we have summarized the relationship between sound waves and plant growth response. Sound waves with specific frequencies and intensities can have positive effects on various plant biological indices including seed germination, root elongation, plant height, callus growth, cell cycling, signaling transduction systems, enzymatic and hormonal activities, and gene expression.

Linear Instability and Saturation Characteristics of Magnetosonic Waves along the Magnetic Field Line

  • Min, Kyungguk;Liu, Kaijun
    • Journal of Astronomy and Space Sciences
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    • v.37 no.2
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    • pp.85-94
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    • 2020
  • Equatorial noise, also known magnetosonic waves (MSWs), are one of the frequently observed plasma waves in Earth's inner magnetosphere. Observations have shown that wave amplitudes maximize at the magnetic equator with a narrow extent in their latitudinal distribution. It has been understood that waves are generated from an equatorial source region and confined within a few degrees magnetic latitude. The present study investigates whether the MSW instability and saturation amplitudes maximize at the equator, given an energetic proton ring-like distribution derived from an observed wave event, and using linear instability analysis and particle-in-cell simulations with the plasma conditions at different latitudes along the dipole magnetic field line. The results show that waves initially grow fastest (i.e., with the largest growth rate) at high latitude (20°-25°), but consistent with observations, their saturation amplitudes maximize within ±10° latitude. On the other hand, the slope of the saturation amplitudes versus latitude revealed in the present study is not as steep as what the previous statistical observation results suggest. This may be indicative of some other factors not considered in the present analyses at play, such as background magnetic field and plasma inhomogeneities and the propagation effect.

Detection of Sub-Breaking Waves around a Blunt Bow (비대선수 주위의 Sub-Breaking Wave 탐지기법)

  • Myung-Soo Shin;Young-Gill Lee;Eun-Chan Kim;Seung-Il Yang
    • Journal of the Society of Naval Architects of Korea
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    • v.29 no.3
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    • pp.117-124
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    • 1992
  • Waves around a practical hull form and a series 60 model are computed by rectangular variable spacing and staggered flesh systems based on MAC(Marker and Cell) method. As a governing equation, the Euler equation is adopted. The comparison indicates that the computed waves are in good agreement with the measured results and that the MAC method is useful. On the other hand, a critical condition for the appearance of sub-breaking waves derived from the in viscid instability analysis is applied to the calculated flow field around a blunt bow. It is confirmed that the derived condition detects well the appearance of sub-breaking waves.

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Effects of Noradrenaline on the Spontaneous Contraction and Ionic Current in the Antral Circular Muscle of Guinea-pig Stomach

  • Jun, Jae-Yeoul;Lee, Sang-Jin;Kim, Sung-Joon;Suh, Jae-Yul;So, In-Suk;Hwang, Sang-Ik;Kim, Ki-Whan
    • The Korean Journal of Physiology
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    • v.27 no.2
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    • pp.115-122
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    • 1993
  • There is evidence that noradrenaline enhances spontaneous contractions dose-dependently in guinea-pig antral circular muscle. To investigate the mechanism of this excitatory action, slow waves and membrane currents were recorded using conventional microelectrode techniques in muscle strips and the whole cell patch clamp technique in isolated gastric myocytes. On recording slow waves, noradrenaline $(10^{-5}\;M)$ induced the hyperpolarization of the membrane potential, although the shape of the slow waves became tall and steep. Also, spike potentiaIs occurred at the peaks of slow waves. These changes were completely reversed by administration of phentolamine $(10^{-5}\;M),\;an\;{\alpha}-adrenoceptor$ blocker. Noradrenaline-induced hyperpolarization was blocked by apamin $(10^{-7}\;M)$, a blocker of a class of $Ca^{2+}\;-dependent\;K^+$ channels. To investigate the mechanisms for these effects, we performed whole cell patch clamp experiments. Norndrenaline increased voltage-dependent $Ca^{2+}$ currents in the whole range of test potentials. Noradrenaline also increased $Ca^{2+}\;-dependent\;K^+$\;currents, and this effects was abolished by apamin. These results suggest that the increase in amplitude and the generation of spike potentials on slow waves was caused by the activation of voltage-dependent $Ca^{2+}$ channel via adrenoceptors, and hyperpolarization of the membrane potential was mediated by activation of apamin-sensitive $Ca^{2+}\;-dependent\;K^+\;channels$.

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INSTABILITY OF OBLIQUE SHOCK WAVES WITH HEAT ADDITION (후방 발열이 있는 경사 충격파의 불안정성)

  • Choi, J.Y.;Shin, J.R.;Cho, D.R.
    • 한국전산유체공학회:학술대회논문집
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    • 2007.10a
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    • pp.232-235
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    • 2007
  • A comprehensive numerical study was carried out to identify the on-set condition of the cell structures of oblique detonation waves (ODWs). Mach 7 incoming flow was considered with all other flow variables were fixed except the flow turning angles varying from 35 to 38. For a given flow conditions theoretical maximum turning angle is $38.2^{\circ}$ where the oblique detonation wave may be stabilized. The effects of grid resolution were tested using grids from $255{\times}100$ to $4,005{\times}1,600$. The numerical smoked foil records exhibits the detonation cell structures with dual triple points running opposite directions for the 36 to 38 turning angles. As the turning angle get closer to the maximum angle the cell structures gets finer and the oscillatory behavior of the primary triple point was observed. The thermal occlusion behind the oblique detonation wave was observed for the $38^{\circ}$ turning angle.

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Numerical Study of Detonation Wave Structure and Dynamics in a Circular Tube (원형관 내 데토네이션 파 구조 및 동적 특성 수치 연구)

  • Cho, Deok-Rae;Kim, Jong-Kwan;Jang, Keun-Jin;Choi, Jeong-Yeol
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2012.05a
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    • pp.278-281
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    • 2012
  • Numerical studies were performed to investigate the three-dimensional front structure and dynamics features of detonation wave propagating in a circular tube such as Pulse Detonation Engine (PDE). By carrying out a series of parametric study using one step irreversible Arrhenius kinetics model, mechanisms of the three-dimensional front structure were investigated for two-, three-, four and six-cell mode detonations. A comparison with two-dimensional results, the effects of slapping transverse waves in radial direction were confirmed. In the all muti-cell modes, the detonation front structures and smoked-records on the wall are formed by the propagation of transverse waves along the wall in clockwise and counter-clockwise while the slapping move in radial direction. And the strength of reflected waves on the curved wall is changed by the multi-dimensional confinement effect.

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Internal Wave Computations based on a Discontinuity in Dynamic Pressure (동압 계수의 불연속성을 이용한 내면파의 수치해석)

  • 신상묵;김동훈
    • Journal of the Society of Naval Architects of Korea
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    • v.41 no.4
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    • pp.17-29
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    • 2004
  • Internal waves are computed using a ghost fluid method on an unstructured grid. Discontinuities in density and dynamic pressure are captured in one cell without smearing or oscillations along a multimaterial interface. A time-accurate incompressible Navier-Stokes/Euler solver is developed based on a three-point backward difference formula for the physical time marching. Artificial compressibility is introduced with respect to pseudotime and an implicit method is used for the pseudotime iteration. To track evolution of an interface, a level set function is coupled with the governing equations. Roe's flux difference splitting method is used to calculate numerical fluxes of the coupled equations. To get higher order accuracy, dependent variables are reconstructed based on gradients which are calculated using Gauss theorem. For each edge crossing an interface, dynamic pressure is assigned for a ghost node to enforce the continuity of total pressure along the interface. Solitary internal waves are computed and the results are compared with other computational and experimental results.

Simulation study on the nonlinear evolution of EMIC instability

  • Rha, Kicheol;Ryu, Chang-Mo;Yoon, Peter H.
    • The Bulletin of The Korean Astronomical Society
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    • v.37 no.2
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    • pp.119.2-119.2
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    • 2012
  • Charged particle energization is an outstanding problem in space physics. This paper investigates the nonlinear dynamics of Alfve'n-cyclotron waves accompanying particle heating processes and the drift Alfv'en-cyclotron (or EMIC) instability associated with a current disruption event on 29 January 2008 observed with THEMIS satellite by means of a particle-in-cell simulation. The simulation shows that the drift Alfv'en-cyclotron instabilities are excited in two regimes, a relatively low frequency mode propagating in a quasi-perpendicular direction while the second high-frequency branch propagating in a predominantly parallel propagation direction, which is consistent with observation as well as earlier theories. It is shown that parametric decay processes lead to an inverse cascade of Alfv'en-cyclotron waves and the generation of ion-acoustic waves by decay instability. It is also shown that the nonlinear decay processes are accompanied by small perpendicular heating and parallel cooling of the protons, and a pronounced parallel heating of the electrons.

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WAVEs: A Novel and Promising Weapon in the Cancer Therapy Tool Box

  • Sakthivel, K.M.;Prabhu, V. Vinod;Guruvayoorappan, C.
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.5
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    • pp.1719-1722
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    • 2012
  • The Wiskott-Aldrich Syndrome Protein family Verprolin - homologous proteins (WAVEs), encoded by a metastasis promoter gene, play considerable roles in adhesion of immune cells, cell proliferation, migration and destruction of foreign agents by reactive oxygen species. These diverse functions have lead to the hypothesis that WAVE proteins have multi-functional roles in regulating cancer invasiveness, metastasis, development of tumor vasculature and angiogenesis. Differentials in expression of WAVE proteins are associated with a number of neoplasms include colorectal cancer, hepatocellular cancer, lung squamous cell carcinoma, human breast adenocarcinoma and prostate cancer. In this review we attempt to unify our knowledge regarding WAVE proteins, focusing on their potentials as diagnostic markers and molecular targets for cancer therapy.