• Title/Summary/Keyword: J. D. Green

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Some properties of the Green's function of simplified elastodynamic problems

  • Sanchez-Sesma, Francisco J.;Rodriguez-Castellanos, Alejandro;Perez-Gavilan, Juan J.;Marengo-Mogollon, Humberto;Perez-Rocha, Luis E.;Luzon, Francisco
    • Earthquakes and Structures
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    • v.3 no.3_4
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    • pp.507-518
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    • 2012
  • It is now widely accepted that the resulting displacement field within elastic, inhomogeneous, anisotropic solids subjected to equipartitioned, uniform illumination from uncorrelated sources, has intensities that follow diffusion-like equations. Typically, coda waves are invoked to illustrate this concept. These waves arrive later as a consequence of multiple scattering and appear at "the tail" (coda, in Latin) of seismograms and are usually considered an example of diffuse field. It has been demonstrated that the average correlations of motions within a diffuse field, in frequency domain, is proportional to the imaginary part of Green's function tensor. If only one station is available, the average autocorrelation is equal to the average squared amplitudes or the average power spectrum and this gives the Green's function at the source itself. Several works address this point from theoretical and experimental point of view. However, a complete and explicit analytical description is lacking. In this work we study analytically some properties of the Green's function, specifically the imaginary part of Green's function for 2D antiplane problems. This choice is guided by the fact that these scalar problems have a closed analytical solution (Kausel 2006). We assume the diffusiveness of the field and explore its analytical consequences.

2-Dimensional Numerical Studies on Thin HTS Film under Time Varying Magnetic Field Using Finite Element Method (변화하는 자기장 하에 있는 고온초전도체에 대한 유한요소법을 이용한 2차원 수치해석 연구)

  • Kwak, K.S.;Lee, H.Y.;Rhee, J.K.;Youm, D.;Yoo, J.;Han, Y.H.;Park, B.J.
    • Progress in Superconductivity
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    • v.13 no.3
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    • pp.151-157
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    • 2012
  • In this paper, we used E-J constitutive law and H-formulation to calculate magnetic field profile, current density, and magnetization of high temperature superconductor (HTS) placed in time varying applied magnetic field. Finite element method (FEM)-based software, Comsol Multiphysics 3.5a, was employed to simulate 2-dimensional model of a superconducting thin strip. The numerical results based on Kim's critical state model were compared with the case of strip in a perpendicular field in the Brandt's paper as well as experimental data observed by Scanning Hall Probe and SQUID.

$Nd^{3+}$ ACTIVARED OXIDE NONLINEAR LASER CRYSTALS IN THE GREEN

  • Garcia Sole, J.;Jaque, D.;Molero, F.;Capmany, J.
    • Proceedings of the Korea Association of Crystal Growth Conference
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    • 1998.06a
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    • pp.19-22
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    • 1998
  • In this work, nonlinear crystals are investigated as investigated ad future diode pumped host laser materials in the green. Optical properties( absorption, emission, secind harmonic generation, and continuous wave lader oscillation in the green) of the most relevant neodymium activeated oxide lader crystals{{{{ ({LiNbO }_{ 3}:MgO, YAI({BO }_{3})_{4} and {LaBGeO }_{ 5})}}}} are investigated and compared under similar experimental conditions

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Effects of Green Tea Powder on Laying Performance and Egg Quality in Laying Hens

  • Uuganbayar, D.;Bae, I.H.;Choi, K.S.;Shin, I.S.;Firman, J.D.;Yang, C.J.
    • Asian-Australasian Journal of Animal Sciences
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    • v.18 no.12
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    • pp.1769-1774
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    • 2005
  • This experiment was carried out to evaluate the effects of feeding green tea powder on laying performance and egg quality in hens. A total 180 'Tetran Brown' laying hens aged 40 weeks were assigned to 6 treatments in a completely randomized design. Each treatment consisted of five replicates accommodating six layers per replication. The experimental diets were a negative control containing no green tea, a positive control diet containing antibiotics (0.05% chlortetracycline) and diets containing 0.5%, 1.0%, 1.5% and 2.0% green tea powder. Egg production rate of layers fed the diets containing green tea powder did not differ significantly from that of the negative and positive controls (p>0.05). Egg weight was decreased significantly in the group fed the diet containing 0.5% green tea powder (p<0.05). Feed intake of layers was significantly higher for the diet containing 1.5% green tea powder compared to that of negative and positive control diets (p<0.05). The eggshell thickness reduced significantly in the layer group fed the diets containing green tea powder regardless of dietary levels (p<0.05). Green tea powder tended to reduce egg yolk cholesterol in this experiment. Particularly, dietary 2% level of green tea powder significantly suppressed the cholesterol contents of the egg yolk (p<0.05). Thiobarbituric acid value (TBA) of egg yolk was significantly reduced by green tea diets (p<0.05). The yellowness of egg yolk was increased in the layers fed the 2.0% green tea diet compared with that of control diet (p<0.005). The Linoleic and $\alpha$-linolenic acids tended to increase in the group fed diets containing 1.5% green tea powder even though there were no significant differences among treatments (p>0.05). The oleic and docosahexaenoic acid contents of the egg yolk were similar among treatments (p>0.05). Based on the results of the experiment, it is concluded that green tea powder inclusion in the diet for layers at 2.0% level can reduce the cholesterol content and TBA value of the egg yolk, implying its potential effect on egg quality parameters.

Tb3+ and Ce3+ Intercalated Laponite Powder: The Influence of Ce3+ Ions on Thermal Stability and Optical Properties of Tb3+ Intercalated Laponite

  • Lee, Han-Na;Kim, You-Hyuk
    • Bulletin of the Korean Chemical Society
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    • v.32 no.4
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    • pp.1273-1276
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    • 2011
  • Laponite samples intercalated with $Tb^{3+}$ or $Tb^{3+},Ce^{3+}$ ions were prepared by exchange of Na+ ions in interlayers with $Tb^{3+}$ or $Ce^{3+}$ ions. Strong green and weak blue emissions under vacuum ultraviolet (VUV) excitation (${\lambda}$ = 158 nm) were observed due to the $^5D_4{\rightarrow}^7F_J$ and $^5D_3{\rightarrow}^7F_J$ emission lines, respectively. $Tb^{3+}$ ions in an interlayer of laponite mainly existed in ion pairs or clusters, as evidenced by the concentration-dependent luminescence of the $Tb^{3+}$ ions on the relative intensities of the $^5D_3{\rightarrow}^7F_J$ and the $^5D_4{\rightarrow}^7F_J$ emission lines, due to the action of a cross-relaxation process. The addition of $Ce^{3+}$ ions increased the thermal stability of $Tb^{3+}$ intercalated laponite up to $650^{\circ}C$ and quenched the $^5D_3{\rightarrow}^7F_J$ emission lines, probably by promoting the formation of $Tb^{3+}$ ion pairs at relatively low $Tb^{3+}$ concentrations.

Lorentz Force Density Distribution of a Current Carrying Superconducting Tape in a Perpendicular Magnetic Field

  • Yoo, J.;Kwak, K.;Rhee, J.;Park, C.;Youm, D.;Park, B.J.;Han, Y.H.
    • Progress in Superconductivity and Cryogenics
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    • v.12 no.4
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    • pp.13-16
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    • 2010
  • The Lorentz force distribution of a high $T_c$ superconducting tape with increasing transport currents in magnetic field ($H_a$) was visualized. The external magnetic field was applied normally to the coated conductor tape surface after zero-field cooling, and the transport current ($I_a$) was increased stepwise from 0 to 90 % of the values of the critical current ($I_c$ ($H_a$)) at applied filed, Ha. The field distribution (H(x)) near the sample surface across the tape width (2w) was measured using the scanning Hall probe method. Applying an inversion to the measured field distribution, we obtained the underlying current distribution (J(x)), from which the magnetic induction, B(x) was calculated with Biot-Savart law. Then Lorentz force per unit length was calculated using F(x)=J(x)${\times}$B(x), which appears to be very inhomogeneous along the tape width due to the complicated distributions of J(x) and B(x).

Low-Power Analog Circuit Design (저전력 아날로그 회로기술)

  • Jeon, Y.D.;Cho, M.H.;Lee, H.D.;Kwon, J.K.;Kim, J.D.
    • Electronics and Telecommunications Trends
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    • v.23 no.6
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    • pp.81-91
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    • 2008
  • CMOS 공정의 가속적인 스케일링에 의해 CMOS 기술은 종래의 마이크론기술에서 나노기술로 변해가고 있다. 이러한 반도체 소자 및 제작기술에 따른 온도와 공정의 변화에 매우 민감한 부분인 아날로그 회로는 설계 초기단계에서 중요한 요소들(이득, 누설 전류, 잡음 및 부정합 등)을 재검토할 필요가 있다. 또한, 나노 CMOS 공정을 사용한 1.0 V 이하의 저전압 동작에서는 아날로그 신호의 동적영역 확보가 어렵고 잡음이 증가하므로 새로운 패러다임을 적용한 혁신적인 아날로그 회로기술 개발이 필요한 실정이다. 이에 따라, 본 고에서는 그린기술(green technology)의 한 요소로서, 나노 CMOS 공정기술을 이용한 1.0 V 이하 전원전압의 저전력 아날로그 회로기술 동향과 관련 특허동향에 대해서 살펴보고자 한다.

Effect of Light Emitting Diode on Growth and Flowering of Oriental Melon (Cucumis melo L. var makuwa Makino)

  • Shin, Y.S.;Lim, Y.S.;Lee, M.J.;Han, Y.Y.;Park, S.D.;Chae, J.H.
    • Korean Journal of Organic Agriculture
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    • v.19 no.spc
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    • pp.203-205
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    • 2011
  • Investigation on oriental melon was carried out for 30 minutes starting at 7 PM every day from March 21 to May 24 to find out the effect of light emitting diode on seedling quality, grafting, growth and flowering of oriental melon. According to the result of the investigation, plant height was longer in Blue, Infrared, Red+Blue and Red treatment and leaf number was higher in Blue, Red+Blue and Infrared treatment than those of control. No big difference was identified between control and Yellow, Green, Ultraviolet treatments. Grafting rate was high in Green, Red+Blue and Green treatment. The number of flower every week in control was nine, the number was almost 1 higher in White and Ultraviolet A treatments, but it was 1 to 4 lower in the rest of treatments. The number of female flowers of control was 10, however, it was 21 in Infrared treatment, 17 in White, 15 in Ultraviolet, 13 in Red+lnfrared, 12 in Blue and Red+Blue, 11 in Yellow and 8 in Green.