• Title/Summary/Keyword: Free charges

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Theoretical Results for a Dipole Plasmonic Mode Based on a Forced Damped Harmonic Oscillator Model

  • Tongtong Hao;Quanshui Li
    • Current Optics and Photonics
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    • v.7 no.4
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    • pp.449-456
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    • 2023
  • The localized surface-plasmon resonance has drawn great attention, due to its unique optical properties. In this work a general theoretical description of the dipole mode is proposed, using the forced damped harmonic oscillator model of free charges in an ellipsoid. The restoring force and driving force are derived in the quasistatic approximation under general conditions. In this model, metal is regarded as composed of free charges and bound charges. The bound charges form the dielectric background which has a dielectric function. Those free charges undergo a collective motion in the dielectric background under the driving force. The response of free charges will not be included in the dielectric function like the Drude model. The extinction and scattering cross sections as well as the damping coefficient from our model are verified to be consistent with those based on the Drude model. We introduce size effects and modify the restoring and driving forces by adding the dynamic depolarization factor and the radiation damping term to the depolarization factor. This model provides an intuitive physical picture as well as a simple theoretical description of the dipole mode of the localized surface-plasmon resonance based on free-charge collective motion.

A Study of Explosive Jet-cutting Technology by Linear Shape Charges (성형폭약에 의한 폭발절단기술에 관한 연구)

  • 이병일;박근순;공창식;김광태
    • Tunnel and Underground Space
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    • v.10 no.4
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    • pp.516-525
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    • 2000
  • Recently, the demand for pollution-free demolition work of old reinforced concrete and steel structure has rapidly increased as the redevelopment of urban area has been accelerated. This study deals with linear shape charges for explosive jet cutting on steel structure. We have tested material and shape of steel structure, characteristics of thickness and strength, shape of linear shape charges, type of shape charges, cumulative charges, type of liner, stand-off distance, detonation method. effect of sound and vibration by air blast in explosive jet cutting method. So, We developed linear shape charges in order to take advantage of optimum explosive jet cutting condition. Shape charges were made of PETN explosives. We obtained the experimental formula to decide the amount of explosive needed for thickness of steel structure plate. There are prospects for application of the explosion curving technology under the open space conditions for dismantling the steel structure and steel bridge, scrapped old boats, which are going out of service.

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Product Category and Shopping Options of Logistic Service Quality

  • KIM, Ok;CHEON, Hongsik J.
    • Journal of Distribution Science
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    • v.18 no.8
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    • pp.113-125
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    • 2020
  • Purpose: The purpose of this paper is to investigate the effect of interaction between product category (fresh vs. indulgent product) and shopping options (shipping charge and delivery time) on customer satisfaction and purchase intent in an e-commerce context. When ordering groceries online, consumers begin to allocate a larger share of their grocery budget toward product categories that generally contain healthier items at the expense of product categories that generally contain more indulgent products. Moreover, customers are extremely sensitive to shipping options such as shipping charges and delivery time. Therefore, this research investigates the issue at a more segmented level to focus on the impact that one dimension of logistics service quality - product category, shipping charge, and delivery time have on customer satisfaction and purchase intent. Research design, data, and methodology: To test the theoretically derived priori hypotheses concerning product category, shipping charges, delivery time, satisfaction, and purchase intent, this research presented a scenario-based experiment. Eight treatment groups were assigned by the method of product category (fresh produce vs. indulgent product), shipping charge (free vs. paid), and delivery time (one-day vs. two to three days). A total of 240 subjects were divided into groups and exposed to one of the eight scenarios. Participant's purchase intention was the dependent variable, and ANOVA and L-matrix were used to analyze for main and interactive effects between factors. Conclusions: Results indicated that in tests 1 and 2, free shipping and fast delivery time increased consumer satisfaction as well as purchase intent, and fast delivery moderated the impact of free shipping on consumer satisfaction and purchase intent. Test 3 showed that the effect of free shipping on consumer satisfaction and purchase intent moderated by fast delivery for indulgent products. In contrast, fast delivery for fresh products moderated the effect of paid shipping on consumer satisfaction and purchase intent. Consistent with this proposed mechanism, the relative importance of fresh produce versus indulgent products highlights the effect of shipping options on consumer satisfaction and purchase intent when ordering the target product in an e-commerce context. We conclude with a discussion of the theoretical and practical implications of our findings.

Comparison of retention characteristics of ferroelectric capacitors with $Pb(Zr, Ti)O_3$ films deposited by various methods for high-density non-volatile memory.

  • Sangmin Shin;Mirko Hofmann;Lee, Yong-Kyun;Koo, June-Mo;Cho, Choong-Rae;Lee, June-Key;Park, Youngsoo;Lee, Kyu-Mann;Song, Yoon-Jong
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.3 no.3
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    • pp.132-138
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    • 2003
  • We investigated the polarization retention characteristics of ferroelectric capacitors with $Pb(Zr,Ti)O_3$ (PZT) thin films which were fabricated by different deposition methods. In thermally-accelerated retention tests, PZT films which were prepared by a chemical solution deposition (CSD) method showed rapid decay of retained polarization charges as the thickness of the films decreased down to 100 nm, while the films which were grown by metal organic chemical vapor deposition (MOCVD) retained relatively large non-volatile charges at the corresponding thickness. We concluded that in the CSD-grown films, the thicker interfacial passive layer compared with the MOCVD-grown films had an unfavorable effect on retention behavior. We observed the existence of such interfacial layers by extrapolation of the total capacitance with thickness of the films and the capacitance of these layers was larger in MOCVD-grown films than in CSD-grown films. Due to incomplete compensation of surface polarization charges by the free charges in the metal electrodes, the interfacial field activated the space charges inside the interfacial layers and deposited them at the boundary between the ferroelectric layer and the interfacial layer. Such space charges built up an internal field inside the films, which interfered with domain wall motion, so that retention property at last became degraded. We observed less imprint which was a result of less internal field in MOCVD-grown films while large imprint was observed in CSD-grown films.

Computation of Circuit Parameters of Multiconductor Transmission Lines with Arbitrary Cross Section (임의 단말을 가진 전송선의 회로정수 산출)

  • 김종민;김종해;하상욱;라극환
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.26 no.12
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    • pp.1918-1925
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    • 1989
  • A method for computing the capacitance and inductance matrix for 2-D multiconductor transmission lines with arbitrary cross section in dielectric medium is presented. The integral equation is obtained by using a free space Green function in conjunction with free and bound charges existing on boundary surfaces. The numerical analysis is based on the moment method using point matching and Galerkin method. And kthe scheme to reduce memory and computation time is presented for symmetric structure.

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Failure Modeling of Bridge Components Subjected to Blast Loading Part II: Estimation of the Capacity and Critical Charge

  • Quintero, Russ;Wei, Jun;Galati, Nestore;Nanni, Antonio
    • International Journal of Concrete Structures and Materials
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    • v.1 no.1
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    • pp.29-36
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    • 2007
  • The purpose of this paper is the assessment of the capacity of the reinforced concrete (RC) elements of an arch bridge when they are subjected to contact and near-contact explosive charges of various amounts, and the estimation of the critical charges for these components. The bridge considered is the Tenza Viaduct, a decommissioned structure south of Naples, Italy. Its primary elements, deck, piers and arches were analyzed. The evaluation was accomplished via numerical analyses that made possible to obtain the elements dynamic response when they are exposed to blast loading conditions. To evaluate the member's capacities, failure criteria for deck, piers and arches were proposed based on concrete damage parameters. Additionally, curves relating the explosive charge to the residual capacity and to damage level of the elements were also developed. The results of this work were taken into account to investigate the progressive collapse of the global structure.

Failure Modeling of Bridge Components Subjected to Blast Loading Part I: Strain Rate-Dependent Damage Model for Concrete

  • Wei, Jun;Quintero, Russ;Galati, Nestore;Nanni, Antonio
    • International Journal of Concrete Structures and Materials
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    • v.1 no.1
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    • pp.19-28
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    • 2007
  • A dynamic constitutive damage model for reinforced concrete (RC) structures and formulations of blast loading for contact or near-contact charges are considered and adapted from literatures. The model and the formulations are applied to the input parameters needed in commercial finite element method (FEM) codes which is validated by the laboratory blast tests of RC slabs from literature. The results indicate that the dynamic constitutive damage model based on the damage mechanics and the blast loading formulations work well. The framework on the dynamic constitutive damage model and the blast loading equations can therefore be used for the simulation of failure of bridge components in engineering applications.

Selective Erase Driving of PDP's with Three Wall Charge States

  • Jung, Young-Ho;Jeong, Ju-Young
    • 한국정보디스플레이학회:학술대회논문집
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    • 2003.07a
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    • pp.702-705
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    • 2003
  • We reported the result of driving PDP's in selective erase scheme and three wall charge states. Compared to the selective write driving scheme, the selective erase scheme achieved flicker free half-ON state with much simpler driving waveforms than the selective write scheme. We believed that this improvement was possible since the cells entering the address period with enough wall charges to modulate easily with.

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Structure and Activity of Quinolone Antibacterial Agents. 1. 7-Substituted 1-Ethyl-6-fluoro-1,4-dihydro-4-oxoquinoline-3-carboxylic Acids

  • Shin, Youn-Ho;Ryu, Eung K.;Kang, Young-Kee
    • Bulletin of the Korean Chemical Society
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    • v.11 no.5
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    • pp.376-379
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    • 1990
  • To find out a correlation between antibacterial activity and physical properties of 7-substituted 1-ethyl-6-fluoro-1,4-dihydro-4-oxoquinoline-3-carboxylic acid, dipole moments, charge distributions, and hydrophobicities were calculated. The atomic charges and the dipole moments to not give any correlations with inhibition of DNA gyrase, but the calculated hydration free energies show some correlations.

Ab Initio and Experimental Studies on Dibenzothiazyl-Disulfide

  • Jian, Fang-Fang;Zhang, Ke-Jie;Zhao, Pu-Su;Zheng, Jian
    • Bulletin of the Korean Chemical Society
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    • v.27 no.7
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    • pp.1048-1052
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    • 2006
  • Ab initio calculations of the structure, atomic charges and natural bond orbital (NBO) have been performed at HF/6-311G** and B3LYP/6-311G** levels for the title compound of dibenzothiazyl-disulfide. The calculated results show that the two nitrogen atoms have the biggest negative charges and they are the potential sites to react with the metallic ions, which make the title compound become a di-dentate ligand. Vibrational frequencies of the title compound have been obtained and compared with the experimental value and the comparison indicates that B3LYP/6-311G** level is better than HF/6-311G** level to predict the vibrational frequencies for the system studied here. For the title compound, electronic absorption spectra calculated by time?ependent density functional theory (TD-DFT) are more accurate than Hartree-Focksingle-excitation CI (CI-Singles) method. NBO analyses show that the electronic transitions are mainly derived from the contribution of bands $\pi\rightarrow\pi^{*}$. Thermodynamic calculated results show that the formation of the title compound from 2-mercaptobenzothiazole is a spontaneous process at room temperature with the change of free Gibbs being negative value.