• Title, Summary, Keyword: dielectric

Search Result 7,460, Processing Time 0.049 seconds

The measurement of Ozone Concentration and Simulation of Electric Field Distribution at Dielectric Tube of one Layer with Globular Dielectric in Water (구형 유전체비드를 가지는 단층절연방전관의 수(水)오존농도측정 및 전계분포 시뮬레이션)

  • Lee, Dong-Hoon;Park, Jae-Youn;Park, Hong-Jae;Koh, Hee-Seog;Lee, Hyun-Su
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • /
    • pp.44-47
    • /
    • 2003
  • In this paper, the electric field distribution in dielectric tube with one layer and spherical dielectric($ZrO_2$) in water was simulated. The reactor was made up of the spherical dielectric that is diameter : 3.0[mm], $ZrO_2(\varepsilon_r:10)$ and one glass plate of thickness(2[mm]), $\varepsilon_r$(10) as electrode. The discharge gap was 8[mm]. To get more strong electric field, the dielectric constant should be higher comparatively. Using the spherical dielectric for water discharge in dielectric tube, the location of equipotential line was shifting from the interior to the exterior. At real water discharge experimental, ozone was measured higher dissolved ozone in water at condition of water rate(l[l/min]) and injector than condition of non-injector or 2~3[l/min].

  • PDF

The measurement of $H_2O_2$ Concentration and Simulation of Electric Field Distribution at Dielectric Tube of one Layer with Globular Dielectric in Water (구형 유전체비드를 가지는 단층절연방전관의 $H_2O_2$ 농도 측정 및 전계분포시뮬레이션)

  • Park, Hong-Jae;Park, Jae-Youn;Lee, Dong-Hoon;Koh, Hee-Seog;Lee, Hyun-Su
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • /
    • pp.40-43
    • /
    • 2003
  • In this paper, the electric field distribution in dielectric tube with one layer and spherical dielectric(glass) in water was simulated. The reactor was made up of the spherical dielectric that is diameter : 3.0[mm], glass(${\varepsilon}_r$:5) and one glass plate of thickness(2[mm]), ${\varepsilon}_r$(5) as electrode. The discharge gap was 8[mm). Toget more strong electric field, the dielectric constant should be higher comparatively. Using the spherical dielectric for water discharge in dielectric tube, the location of equipotential line was shifting from the interior to the exterior. At real water discharge experimental, $H_2O_2$ was measured higher generated $H_2O_2$ in water at condition of water rate(1[l/min]) and injector than condition of non-injector or 2-3[l/min])

  • PDF

Fabrication and Characterization of Dielectric Materials of Front and Back Panel for PDP

  • Chang, Myeong-Soo;Pae, Bom-Jin;Lee, Yoon-Kwan;Ryu, Byung-Gil;Park, Myung-Ho
    • Journal of Information Display
    • /
    • v.2 no.3
    • /
    • pp.39-43
    • /
    • 2001
  • The glass compositions of $PbO-SiO_2-B_2O_3$ system and $P_2O_5-PbO-ZnO$ system for the transparent dielectric materials for front panel and $P_2O_5$-ZnO-BaO and $SiO_2-ZnO-B_2O_3$ for the reflective dielectric materials for back panel of PDP (Plasma Display Panel) were investigated. As a result, transparent dielectric materials for front panel showed good dielectric properties, high transparency, and proper thermal expansion matching to soda lime glass substrate. And the reflective dielectric layers for back panel were prepared from two series of parent glass and oxide filler. It was found that these glassceramics are useful materials for dielectric layers in PDP device, as they have similar thermal expansion to soda-lime glass plate, high reflectance, and low sintering temperature. In particular, the addition of $BPO_4$ and $TiO_2$ as fillers to $SiO_2-ZnO-B_2O_3$ system is considered to be the most effective for acquiring good properties of lower dielectric layer for PDP device.

  • PDF

The Structure and Dielectric Properties of the (Ba,Sr)TiO$_3$ Thin Films with the Substrate Temperature (기판온도에 따른 (Ba,Sr)TiO$_3$ 박막의 구조와 유전특성)

  • 이상철;이문기;이영희
    • The Transactions of the Korean Institute of Electrical Engineers C
    • /
    • v.49 no.11
    • /
    • pp.603-608
    • /
    • 2000
  • $(Ba, Sr)TiO_{3}$[BST] thin films were fabricated on the Pt/TiO$_2$/SiO$_2$/Si substrate by the RF sputtering. The structure and dielectric properties of the BST thin films with the substrate temperature were investigated. Increasing the substrate temperature, The BST phase increased and barium multi titanate phases decreased. Increasing the frequency, the dielectric constant decreased and the dielectric loss increased. The dielectric constant and dielectric loss of the BST thin films deposited at 50$0^{\circ}C$ were 300 and 0.018, respectively at 1 kHz. The leakage current density of the BST thin films deposited at 50$0^{\circ}C$ was $10^{-9}$ A/$\textrm{cm}^2$ with applied voltage of 3V. Because of the high dielectric constant(300), low dielectric loss(0.018) and low leakage current($10^{-9}$ A/$\textrm{cm}^2$), BST thin films deposited at 50$0^{\circ}C$ is expecting for the application of DRAM.

  • PDF

Method for Measuring Dielectric Constant of Planar Dielectric Substrate (판형 유전체의 유전율 측정 방법)

  • Lee, Chang-Hyun;Kwon, Taek-Sun;Lee, Jeong-Hae
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.29 no.10
    • /
    • pp.799-804
    • /
    • 2018
  • In this paper, a method for measuring the dielectric constant of a planar dielectric substrate using the free space material constant measurement method in a general measurement environment is proposed. Two horn antennas and a network analyzer were used for S-parameter measurement and the transmission and reflection coefficients of a planar dielectric substrate were calculated from the measurement results. To obtain a reliable dielectric constant in a low-precision-measurement environment, only the magnitude of the transmission coefficient, which has a small error due to the measurement environment, is used for dielectric constant estimation. Finally, the dielectric constant is determined by comparing the measured results at different frequencies.

The Microwave Measurement of the Dielectric Properties of Low-Loss Materials by the Dielectric Rod Resonator Method (고주파 대역에서 Dielectric Rod Resonator 방법에 의한 저유전 손실 물질의 유전 특성 측정)

  • Kim, Geun-Young;Shim, Hwa-Sup;An, Chul;Chang, Ik-Soo
    • Journal of the Korean Institute of Telematics and Electronics
    • /
    • v.27 no.10
    • /
    • pp.10-15
    • /
    • 1990
  • Theory and experimental results of measuring the microwave dielectric characteristics of low-loss materials by using dielectric rod resonator method are presented. The $TE_{011}$ mode resonance frequency was adapted to minimize the effect of the air gap between the rod and the conducting plates. The dielectric properties were computed from the resonance frequency, sample geometry and 3 dB bandwidth. The error of measurements was within ${\pm}3{\%}$ for dielectric constant and was within ${\pm}12{\%}$ for dielectric loss.

  • PDF

Physico-chemical and dielectric relaxation studies of ionic surfactants in Time Domain Reflectometry (TDR)

  • Kalaivani, Thirunavukarasu;Krishnan, Subramanian;Nithiyanantham, Subramanian
    • The Korean Journal of Chemical Engineering
    • /
    • v.34 no.8
    • /
    • pp.2325-2330
    • /
    • 2017
  • The properties of aqueous surfactant solutions with external additives are extensively useful in surfactant-based systems. To study the dielectric relaxation studies of aqueous ionic surfactants (SDS, CTAB, DPC) and aqueous butanol, benzyl alcohol, aniline and tributylamine were carried out for different concentrations at 303k. Dielectric relaxation spectroscopy (DRS) is valuable for understanding the dynamic process mainly in micellar systems. Time domain dielectric data were obtained through HP54750A oscilloscope and TDR plug-in-module. The relaxation times were determined through the well-known Cole-Cole method. The superposition of two relaxation times gives the dielectric relaxation time obtained from the hydrated water molecule with rotations around the micelle, ions and another hydrophobic inner side of the micelle. Viscosity measurements were used to correlate the dielectric data. The Kirkwood correlation factor ($g_f$), effective Kirkwood correlation factor ($g_{eff}$), Bruggeman Factor ($f_B$), excess inverse relaxation time $(1/{\tau})^E$, excess dielectric constant (${\varepsilon}^E$) and free energy of activation (${\Delta}F_t$) were also calculated. The effects of dielectric relaxation and viscous flow were interpreted and discussed.

Dielectric Properties of Ceramic/Polymer Composites at Microwave Frequencies

  • Kim, Eung-Su;Jeon, Chang-Jun
    • Proceedings of the Materials Research Society of Korea Conference
    • /
    • /
    • pp.19.1-19.1
    • /
    • 2011
  • Effects of particle size, crystal structures and multilayer structures of $ATiO_3$, $ATa_2O_6$, $ANb_2O_6$, $AWO_4$, and $AMoO_4$ (A=Ni, Mg, Zn, Co) ceramic fillers on the dielectric properties of polystyrene (PS), polypropylene (PP) and polytetrafluoroethylene (PTFE) polymer matrices were investigated at microwave frequencies. The microwave dielectric properties of $ATiO_3$ (ilmenite), $ATa_2O_6$ (tri-rutile), $ANb_2O_6$ (columbite), AWO4 (wolframite), and AMoO4 (wolframite) ceramics were largely dependent on the structural characteristics of oxygen octahedra. The dielectric constant (K) of the composites was increased with the ceramic content. However, the dielectric loss (tan ${\delta}$) of the composites was affected by the type of ceramics and the crystallinity of polymers. For the composites with same amount of ceramics, the K was decreased and the tan ${\delta}$ was increased with the particle size of ceramics. Also, the dielectric properties of the composites were dependent on the multilayer structures with different arrangements. Several theoretical models have been employed to predict the effective dielectric properties of the composites. The frequency dependence of dielectric properties and the temperature coefficient of resonant frequency (TCF) of the composites were also discussed.

  • PDF

Evaluation of Microwave Dielectric Properties of MgO-TiO2 System by Dielectric Mixing Rules

  • Kim, Eung-Soo;Seo, Seock-No
    • Journal of the Korean Ceramic Society
    • /
    • v.47 no.2
    • /
    • pp.163-168
    • /
    • 2010
  • Effects of compositions on the microwave dielectric properties of the MgO-$TiO_2$ system were investigated as a function of the molar ratio of MgO to $TiO_2$ ($0.9{\leq}MgO/TiO_2\;(x){\leq}1.2$). With the compositional changes, secondary phases of $MgTi_2O_5$ and $Mg_2TiO_4$ were also detected along with $MgTiO_3$. Microwave dielectric properties of the specimens were dependent on the types of phases developed in the sintered specimens. A single phase of $MgTiO_3$ showed a dielectric constant (K) of 18.2, a quality factor (Qf) of 198,000 GHz, and a temperature coefficient of resonant frequency (TCF) of $-51\;ppm/^{\circ}C$. However, the dielectric properties of the specimens with a secondary phase of $MgTi_2O_5$ (K=19.9, Qf=48,000 GHz) and/or $Mg_2TiO_4$ (K=15.6, Qf=56,000 GHz) were worsened. Dependence of the microwave dielectric properties on the secondary phase of the MgO-$TiO_2$ system was also discussed in terms of dielectric mixing rules.