• Title/Summary/Keyword: Spin

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Spin-Rotation Interaction in Polyatomic Molecules in the Presence of Internal Rotation (內部廻轉存在時의 多原子分子에서의 스핀-廻轉相互作用)

  • Lee Jo W.
    • Journal of the Korean Chemical Society
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    • v.20 no.5
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    • pp.364-373
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    • 1976
  • A magnetic nucleus located on an internal rotor in a polyatomic molecule can interact with the magnetic fields arising from internal rotation as well as end-over-end molecular rotation. In this paper the spin-rotation coupling Hamiltonian for a nuclear spin on a symmetrical internal rotor in a polyatomic molecule is derived. The derived spin-rotation Hamiltonian turns out to be composed of the two parts: the spin-over-all-rotation interaction and the spin-internal-rotation interaction. The relation between the spin-rotation coupling tensor and the magnetic shielding effect is also investigated.

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Diffusion Theory of Spin Injection (스핀 주입에 대한 퍼짐 이론)

  • Lee, B.C.
    • Journal of the Korean Magnetics Society
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    • v.16 no.2
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    • pp.121-129
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    • 2006
  • The diffusion theory for spin injection from magnetic layer into nonmagnetic layer was reviewed. Basic equations were derived and applied to a ferromagnet/semiconductor/ferromagnet system. The spin polarization and magnetoresistance were calculated. The reason for difficulty in detecting spin injection with magnetoresistance was explained, and a possible solution was discussed.

Studies on the cell cycle of saccharomyces cerevisiae by electron spin resonance spectroscopy (전자스핀공명스펙트럼에 의한 saccharomyces cerevisiae의 세포환 연구)

  • 임형순;강사욱
    • Korean Journal of Microbiology
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    • v.26 no.1
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    • pp.44-51
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    • 1988
  • The intracellular free radicals produced at different stages of cell cycle of Saccharomyces cerevisiae ATCC 24858 were investigated by means of electron spin resonance(ESR) spectroscopy. The synchronized cells by repeated starvation and refeeding revealed different ESR spectral pattern compared to that of asynchronized cells. Each spectrum centered at g=2.005, which indicates free radicals. The relative spin concentration was maximat at the end of DNA increase. The variation of the relative spin concentration at each distinct stage of the cell cycle was evaluated in relation to ascorbate concentration, L-galactonolactone oxidase activity, and ascorbate oxidase activity. The highest activities of L-galactonolactone oxidase and ascorbate oxidase were detected just before and at the maximum of relative spin concentration, respectively. And ascorbate concentration fluctuated through each stage of cell cycle with the changes of relative spin concentration, L-galactonolactone oxidase activity, and ascorbate oxidase activity. Thus it is suggested that intracellular free radicals should be related to cell cycle, interacted with ascorbate, and may play an important role in the cell cycle of Saccharomyces cerevisiae.

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SYNTHESIS AND APPLICATION OF NEW SPIN PROBES

  • Kim, S.D.;Freeman, H.S.;Mcgregor, R.
    • Proceedings of the Korean Fiber Society Conference
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    • 1990.06b
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    • pp.67-67
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    • 1990
  • Three non-ionic and two anioinic spin probes, differing in size and substituent, were synthesized. Their mobility in dried nylon 6 film was investicated by the spin probe technique using electron spin resonance spectrometer. When the size of a spin probe was large and the interaction between the probe molecules and polymer chains existed, the mobility of spin probes decreased. From Arrhenius plots of rotational correlation time, one discontinuity point ($T_d$) was determined. The activation energies for rotation below and above $T_d$ were discussed in terms of the mode of probe rotation. Three spin probes could be viewed as azo dyes having a built-in nitroxide radical. Photolysis of them in dimethylformamide and in nylon 6 film was performed by exposure to 254 nm UV light in the presence of air. It was found that dyes having a built-in nitroxide radical showed better photostability than dyes derived from ${\bata}-naphthol$..

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A Study on Spin-Lattice Relaxation of Methyl Protons in 2,6-Dichlorotoluene and N-Methyl Phthalimide

  • Lee, Jo-Woong;Lim, Man-Ho;Rho, Jung-Rae
    • Bulletin of the Korean Chemical Society
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    • v.12 no.1
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    • pp.47-51
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    • 1991
  • Spin-lattice relaxation of methyl protons in 2,6-dichlorotoluene and N-methyl phthalimide, each dissolved in CDCl$_3$, has been studied at 34$^{\circ}$C and the contribution from spin-rotation interaction to the relaxation process has been separated from that due to dipole-dipole interactions among methyl protons. The results show that the spin-rotational contributions to the initial rate of relaxation in 2,6-dichlorotoluene and N-methyl phthalimide amount to 18 and 31%, respectively, of the total relaxation rate at 34$^{\circ}$C. The method of separating the spin-rotational contribution from that of dipolar interactions adopted in this paper is based on the well known fact that in an A$_3$ spin system such as methyl protons in liquid phase dipolar relaxation mechanism gives non-exponential decay of the z-component of total magnetization of protons while the random field fluctuation such as spin-rotational mechanism causes exponential decay.

Does Tax Really Matter in Planning the Dongbu Group's Spin-Offs? (세무계획측면에서 분석한 동부그룹 물적분할)

  • Jun, Byung Wook;Cho, Hyeong Tae
    • The Journal of Small Business Innovation
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    • v.20 no.1
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    • pp.1-18
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    • 2017
  • This study examined whether divided and spun-off companies design and execute spin-offs to minimize tax burdens by analyzing multiple spin-off transactions in the Dongbu Group, when the Korean tax law regarding corporate restructuring was amended in July 2010. Before the July 2010 tax amendment, taxes on the capital gains arising from the qualifying spin-off were deferred to the earlier of the shares in or assets acquired by the spun-off company are disposed. This tax treatment relieves the divided company's tax burden by deferring taxes on capital gains, compared with non-qualifying spin-offs. However, if shares in or assets acquired by the spun-off company are disposed after the July 2010 tax amendment, the capital gain incurred at the time of the qualifying spin-off would be taxed again at the spun-off company, in addition to a taxation on the divided company's capital gains. This creates double taxation implications for the parties involved in the spin-off. As a result, the double taxation may outweigh the benefit from the tax deferral on the qualifying spin-off, which may make a qualifying spin-off tax unfavorable. Among the four spin-off cases in the Dongbu Group addressed in this study, a spin-off occurred before the tax amendment, whereas three spin-offs occurred after the tax amendment. Initially, we expected that the spin-off before the tax amendment would be a qualifying spin-off, and the other three spin-offs would be non-qualifying spin-offs, considering the taxation rules before and after the July 2010 tax amendment. However, based on the review of summarized balance sheets disclosed in the spin-offs' corporate filings, no capital gains arose during the four spin-offs that occurred in the Dongbu Group. Therefore, we concluded that the Dongbu Group considered non-tax factors more than tax factors while designing and executing the spin-offs. The local media posited during this period that these spin-offs may intend to resolve financial issues in the Dongbu Group, and this analysis was supported by the fact that some shares in the new spun-off companies were sold by the Dongbu Group. Our case studies provide evidence that all costs, including both tax and non-tax costs, must be considered in the course of spin-offs, in addition to the tax burdens on all parties involved in the corporate restructuring, which parallels the work of Scholes et al. (2008). This study provides implications that various aspects should be considered and reviewed in advance when the management makes decisions for effective tax planning.

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