• Title/Summary/Keyword: phase inversion temperature

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Orthotropic magneto-thermoelastic solid with multi-dual-phase-lag model and hall current

  • Lata, Parveen;Himanshi, Himanshi
    • Coupled systems mechanics
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    • v.10 no.2
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    • pp.103-121
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    • 2021
  • The present research deals with the investigation of the effect of hall current in an orthotropic magneto-thermoelastic medium with two temperature in the context of multi-phase-lag heat transfer due to thermomechanical sources. The bounding surface is subjected to linearly distributed and concentrated loads(mechanical and thermal source).Laplace and Fourier transform techniques are used to solve the problem. The expressions for displacement components,stress components and conductive temperature are derived in transformed domain and furtherin physical domain with the help of numerical inversion techniques. The effect ofrotation and hall parameter hasshown with the help of graphs.

Interactions in a homogeneous isotropic modified couple stress thermoelastic solid with multi-dual-phase-lag heat transfer and two temperature

  • Lata, Parveen;Kaur, Harpreet
    • Steel and Composite Structures
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    • v.38 no.2
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    • pp.213-221
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    • 2021
  • The objective of this paper is to study the deformation in a homogeneous isotropic thermoelastic solid using modified couple stress theory subjected to ramp-type thermal source with two temperature. The advantage of this theory is the involvement of only one material length scale parameter which can determine the size effects. Laplace and Fourier transform technique is applied to obtain the solutions of the governing equations. The components of displacement, conductive temperature, stress components and couple stress are obtained in the transformed domain. A numerical inversion technique has been used to obtain the solutions in the physical domain. The effect of two temperature is depicted graphically on the resulted quantities. Numerical results show that the proposed model can capture the size effects of microstructures.

Effect of two-temperature in an orthotropic thermoelastic media with fractional order heat transfer

  • Lata, Parveen;Himanshi, Himanshi
    • Composite Materials and Engineering
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    • v.3 no.3
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    • pp.241-262
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    • 2021
  • In this article, we studied the effect of two-temperature in a two-dimensional orthotropic thermoelastic media with fractional order heat transfer in generalized thermoelasticity with three-phase-lags due to thermomechanical sources. The boundary of the surface is subjected to linearly distributed and concentrated loads (mechanical and thermal source). The solution of the problem is obtained with the help of Laplace and Fourier transform techniques. The expressions for displacement components, stress components and conductive temperature are derived in transformed domain. Numerical inversion technique is used to obtain the results in physical domain. The effect of two-temperature on all the physical quantities has been depicted with the help graphs. Some special cases are also discussed in the present investigation.

Chromatic Dispersion Compensation via Mid-span Spectral Inversion with Periodically Poled $LiNbO_3$ Wavelength Converter at Low Pump Power

  • Kim, Min-Su;Ahn, Joon-Tae;Kim, Jong-Bae;Ju, Jung-Jin;Lee, Myung-Hyun
    • ETRI Journal
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    • v.27 no.3
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    • pp.312-318
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    • 2005
  • Mid-span spectral inversion (MSSI) has to utilize high optical pump power, for its operation principle is based on a nonlinear optical wavelength conversion. In this paper, a low pump-power operation of MSSI-based chromatic dispersion compensation (CDC) has been achieved successfully, for the first time to our knowledge, by introducing a noise pre-reduction scheme in cascaded wavelength conversions with periodically poled $LiNbO_3$ waveguides at a relatively low operation temperature. As preliminary studies, phase-matching properties and operation-temperature dependence of the wavelength converter (WC) were characterized. The WC pumped at 1549 nm exhibited a wide conversion bandwidth of 59 nm covering the entire C-band and a conversion efficiency of -23.6 dB at 11 dBm pump power. CDC experiments were implemented with 2.5 and 10 Gb/s transmission systems over 100 km single-mode fiber. Although it is well-known that the signal distortion due to chromatic dispersion is not critical at a 2.5 Gb/s transmission, the clear recovery of eye patterns was identified. At 10 Gb/s transmission experiments, eye patterns were retrieved distinctly from seriously distorted ones, and notable improvements in bit-error rates were acquired at a low pump power of 14 dBm.

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Transversely isotropic thin circular plate with multi-dual-phase lag heat transfer

  • Lata, Parveen;Kaur, Iqbal;Singh, Kulvinder
    • Steel and Composite Structures
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    • v.35 no.3
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    • pp.343-351
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    • 2020
  • The present research deals with the multi-dual-phase-lags thermoelasticity theory for thermoelastic behavior of transversely isotropic thermoelastic thin circular plate The Laplace and Hankel transform techniques have been used to find the solution of the problem. The displacement components, stress components, and conductive temperature distribution are computed in the transformed domain with the radial distance and further determined in the physical domain using numerical inversion techniques. The effect of rotation and two temperature are depicted graphically on the resulting quantities.

Reaction of Gae-Phase Atomic Hydrogen with Chemisorbed Hydrogen Atoms on an Iron Surface

  • Kim, M. S.;Ree, J.
    • Bulletin of the Korean Chemical Society
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    • v.18 no.9
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    • pp.985-994
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    • 1997
  • The reaction of gas-phase atomic hydrogen with hydrogen atoms chemisorbed on Fe(110) surface is studied by use of classical trajectory procedures. Flow of energy between the reaction zone and bulk solid phase has been treated in the generalized Langevin equation approach. A London-Eyring-Polanyi-Sato energy surface is used for the reaction zone interaction. Most reactive events are found to occur in strong single-impact collisions on a subpicosecond scale via the Eley-Rideal mechanism. The extent of reaction is large and a major fraction of the available energy goes into the vibrational excitation of H2, exhibiting a vibrational population inversion. Dissipation of reaction energy to the heat bath can be adequately described using a seven-atom chain with the chain end bound to the rest of solid. The extent of reaction is not sensitive to the variation of surface temperature in the range of Ts=0-300 K in the fixed gas temperature, but it shows a minimum near 1000 K over the Tg=300-2500 K.

Removal of Oil from Soil Using Nonionic Surfactant : The Effects of Middle Phase Formation and Dynamic Interfacial Tension (비이온 계면활성제를 사용한 토양으로부터 오일의 제거에 관한 연구 : 중간상생성 및 동적 계면장력의 영향)

  • Lee, Kee-Suh;Kim, Young-Ho;Kim, Chul-Ung;Lee, Jung-Min;Koo, Kee-Kahb
    • Clean Technology
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    • v.6 no.1
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    • pp.51-60
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    • 2000
  • The soil remediation by non-ionic surfactant solutions ($C_{12}H_{25}O(CH_2CH_2O)_5H$ and Triton X-100) was studied. Depending on the amounts and use of co-surfactants, MPT(phase inversion temperature), dynamic interfacial tension, and the detergency efficiency of the surfactant solutions in soil were investigated. The oils used were kerosene, n-hexadecane, and paraffin oil. With respect to a higher detergency efficiency, a lower interfacial tension and the MPT was very important. The $C_{12}H_{25}O(CH_2CH_2O)_5H$ was better than Triton X-100 on the oil removal from the soil and the effect of oil kinds was kerosene>paraffin $oil{\geq}n-hexadecane$. The co-surfactant, n-dodecanol, reduced the MPT compared to no addition of this, whereas it did not enhance the detergent efficiency.

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Non-simple magnetothermoelastic solid cylinder with variable thermal conductivity due to harmonically varying heat

  • Zenkour, Ashraf M.;Abouelregal, Ahmed E.
    • Earthquakes and Structures
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    • v.10 no.3
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    • pp.681-697
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    • 2016
  • The model of two-temperature magneto-thermoelasticity for a non-simple variable-thermal-conductivity infinitely-long solid cylinder is established. The present cylinder is made of an isotropic homogeneous thermoelastic material and its bounding plane is traction-free and subjected to a time-dependent temperature. An exact solution is firstly obtained in Laplace transform space to obtain the displacement, incremental temperature, and thermal stresses. The inversion of Laplace transforms has been carried out numerically since the response is of more interest in the transient state. A detailed analysis of the effects of phase-lags, an angular frequency of thermal vibration and the variability of thermal conductivity parameter on the field quantities is presented.

Study on Optimization and Skin Permeation of PIT Nanoemulsion Containing α-Bisabolol (α-Bisabolol을 함유한 PIT Nanoemulsion의 최적화 및 피부흡수연구)

  • Kim, HuiJu;Yoon, Kyung-Sup
    • Journal of the Korean Applied Science and Technology
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    • v.37 no.6
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    • pp.1738-1751
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    • 2020
  • The skin is divided into three parts: the epidermis, the dermis, and the subcutaneous fat, and the stratum corneum, which is located at the top of the epidermis, acts as a barrier that prevents drug delivery. Nanoemulsions are known to be effective in transdermal delivery of drugs through intercellular lipids because of their unique small particle size. In this study, phase inversion temperature (PIT) nanoemulsion containing α-bisabolol was optimized using response surface methodology (RSM) for effective skin absorption of α-bisabolol. As a preliminary experiment, the 25-2 fractional factorial design method and the 23 full factorial design method were performed. Box-Behnken design was performed based on the results of the factorial design method. The content of surfactant (6.3~12.6%), co-surfactant (5.2~7.8%) and α-bisabolol (0.5~5.0%) were used as factors, and the dependent variable was the particle size of the nanoemulsion. PIT nanoemulsion optimization was performed according to the RSM results, and as a result, the optimal nanoemulsion formulation conditions were predicted to be 10.4% surfactant content, 6.3% co-surfactant content, and 5.0% α-bisabolol content. As a result of the skin absorption test, the final skin absorption rate of the PIT nanoemulsion was 35.11±1.01%, and the final skin absorption rate of the general emulsion as a control was 28.25±1.69%, confirming that the skin absorption rate of the PIT nanoemulsion was better.

Enhancement of the Ionic Conductivity and Mechanical Strength of Micro-porous Separator by Uni-axial Drawing

  • Lee Je-An;Seol Wan-Ho;Lee Yong-Min;Park Jung-Ki
    • Journal of the Korean Electrochemical Society
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    • v.9 no.1
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    • pp.29-33
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    • 2006
  • A new porous separator based on poly(vinyl chloride) (PVC)/poly(vinylidene fluoride-co-hexafluoro-propylene) (P(VdF-co-HFP)/poly(methyl methacrylate) (PMMA) was prepared by a phase inversion method. To enhance mechanical property, the membrane was stretched uniaxially at high temperature. Tensile strength and ionic conductivity were measured for various draw ratios. The tensile strength and ionic conductivity were increased with increasing draw ratio. The tensile strength of the separator reached 52MPa after stretching to draw ratio of 5, and the ionic conductivity of the separator was increased from $1.9Xs10^{-4}S/cm\;to\;4.6X10^{-4}S/cm\;at\;25^{\circ}C$. The stretched separator immersed in liquid electrolyte was electrochemically stable up to 4.7 V. The cell based on the stretched separator was maintained at about 99% of the initial discharge capacity after 10th cycle operation at 0.2C rate.