• Title/Summary/Keyword: rotational anisotropy

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Comparative Dynamics of $tRNA^{val}$ and pBluescript II SK(+) Phagemid Studied with Ethidium Bromide and a Long-lifetime Metal-ligand Complex

  • Kang, Jung-Sook;Yoon, Ji-Hye
    • Journal of Photoscience
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    • v.11 no.3
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    • pp.133-139
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    • 2004
  • The metal-ligand complex, $[Ru(phen)_2(dppz)]^{2+}$ (phen=1,10-phenanthroline, dppz=dipyrido[3,2-a:2',3'-c]phenazine) (RuPD), was used as a spectroscopic probe for studying nucleic acid dynamics. The RuPD complex displays a long lifetime and a molecular light switch property upon DNA binding due to shielding of its dppz ligand from water. To show the usefulness of this luminophore (RuPD) for probing nucleic acid dynamics, we compared its intensity and anisotropy decays when intercalated into the $tRNA^{val}$ and pBluescript (pBS) II SK(+) phagemid through a comparison with ethidium bromide (EB), a conventional nucleic acid probe. We used frequency-domain fluorometry with a blue light-emitting diode (LED) as the modulated light source. The mean lifetime for the $tRNA^{val}$ (<${\tau}$> = 166.5 ns) was much shorter than that for the pBS II SK(+) phagemid (<${\tau}$> = 481.3 ns), suggesting a much more efficient shielding from water by the phagemid. Because of their size difference, the anisotropy decay data showed a much shorter rotational correlation times for the $tRNA^{val}$ (99.9 and 23.6 ns) than for the pBS II SK(+) phagemid (968.7 and 39.5 ns). These results indicate that RuPD can be useful for studying nucleic acid dynamics.

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Effects of Hot Asymmetric Rolling on Microstructure and Formability of Aluminum Alloys (고온 비대칭압연이 알루미늄 합금의 미세조직과 성형성에 미치는 영향)

  • Jeong, Museob;Lee, Jongbeom;Han, Jun Hyun
    • Korean Journal of Materials Research
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    • v.29 no.10
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    • pp.647-655
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    • 2019
  • In order to analyze the effect of hot asymmetric rolling on the microstructure and texture of aluminum alloy and to investigate the effect of the texture on the formability and plastic anisotropy of aluminum alloy, aluminum 6061 alloy is asymmetrically rolled at room temperature, $200^{\circ}C$, $350^{\circ}C$, and $500^{\circ}C$, and the results are compared with symmetrically rolled results. In the case of asymmetric rolling, the equivalent strain (${\varepsilon}_{eq}$) is greatest in the upper roll part where the rotational speed of the roll is high and increases with increasing rolling temperature. The increase rate of the mean misorientation angle with increasing temperature is larger than that during symmetrical rolling, and dynamic recrystallization occurs the most when asymmetrical rolling is performed at $500^{\circ}C$. In the case of hot symmetric rolling, the {001}<110> rotated cube orientation mainly develops, but in the case of hot asymmetric rolling, the {111}<110> orientation develops along with the {001}<100> cube orientation. The hot asymmetric rolling improves the formability (${\bar{r}}$) of the aluminum 6061 alloy to 0.9 and reduces the plastic anisotropy (${\Delta}r$) to near zero due to the {111}<110> shear orientation that develops by asymmetric rolling.

The Effect of Methanol on the Structural Parameters of Neuronal Membrane Lipid Bilayers

  • Joo, Hyung-Jin;Ahn, Shin-Ho;Lee, Hang-Rae;Jung, Sung-Woo;Choi, Chang-Won;Kim, Min-Seok;Bae, Moon-Kyoung;Chung, In-Kyo;Bae, Soo-Kyoung;Jang, Hye-Ock;Yun, Il
    • The Korean Journal of Physiology and Pharmacology
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    • v.16 no.4
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    • pp.255-264
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    • 2012
  • The structures of the intact synaptosomal plasma membrane vesicles (SPMVs) isolated from bovine cerebral cortexs, and the outer and the inner monolayer separately, were evaluated with 1,6-diphenyl-1,3,5-hexatriene (DPH) and 1,3-di(1-pyrenyl)propane (Py-3-Py) as fluorescent reporters and trinitrophenyl groups as quenching agents. The methanol increased bulk rotational and lateral mobilities of SPMVs lipid bilayers. The methanol increased the rotational and lateral mobilities of the outer monolayers more than of the inner monolayers. n-(9-Anthroyloxy)stearic acid (n-AS) were used to evaluate the effect of the methanol on the rotational mobility at the 16, 12, 9, 6, and 2 position of aliphatic chains present in phospholipids of the SPMVs outer monolayers. The methanol decreased the anisotropy of the 16-(9-anthroyloxy)palmitic acid (16-AP), 12-(9-anthroyloxy)stearic acid (12-AS), 9-(9-anthroyloxy)stearic acid (9-AS), and 6-(9-anthroyloxy)stearic acid (6-AS) in the SPMVs outer monolayer but it increased the anisotropy of 2-(9-anthroyloxy)stearic acid (2-AS) in the monolayers. The magnitude of the increased rotational mobility by the methanol was in the order at the position of 16, 12, 9, and 6 of aliphatic chains in phospholipids of the outer monolayers. Furthermore, the methanol increased annular lipid fluidity and also caused membrane proteins to cluster. The important finding is that was far greater increase by methanol in annular lipid fluidity than increase in lateral and rotational mobilities by the methanol. Methanol alters the stereo or dynamics of the proteins in the lipid bilayers by combining with lipids, especially with the annular lipids. In conclusion, the present data suggest that methanol, in additions to its direct interaction with proteins, concurrently interacts with membrane lipids, fluidizing the membrane, and thus inducing conformational changes of proteins known to be intimately associated with membranes lipids.

Low Power Consumption in Twisted Nematic Mode Using Novel Liquid Crystal Mixture

  • Jeon, Sang-Youn;Song, In-Bum;Hong, Sung-Ho;Lee, Dong-Jin;Choi, Hyun-Chul;Park, Man-Hyo
    • 한국정보디스플레이학회:학술대회논문집
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    • 2008.10a
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    • pp.337-339
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    • 2008
  • Recently, Note PCs have being widely used due to their features such as good mobility and low power consumption. In order to ensure the current market position, further improvement is required. Especially, the lower operating voltage is essential for the long operating time of Note PCs. For the achievement of lower operating voltage, possible contributions from LC materials side are to lower the viscosity and to increase the dielectric constant without sacrificing the reliability. In order to achieve lower driving voltage, new LC mixtures have been developed, optimizing theirs physical properties.

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Study on Electrically Controlled Birefringence Mode for Field Sequential Liquid Crystal Display (FSLCD용 ECB 모드 연구)

  • Kim, Seung-Jai;Oh, Sang-Min;Lee, Seung-Hee;Shin, Yong-Seop;Kim, Hyang-Yul;Kim, Seo-Yoon;Lim, Young-Jin
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2004.11a
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    • pp.563-566
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    • 2004
  • We have studied a electrically controlled birefringence (ECB) mode for field sequential liquid crystal display (FSLCD). We measured response time of the ECB mode. The ECB mode exhibiting fast response time, high transmittance, low operating voltage and adequate viewing angle. The positive liquid crystal (LC) is better than negative LC on dielectric anisotropy, birefringence and rotational viscosity. So that, the ECB mode is one of strongest candidate for FSLCD application.

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Turbulent Flow through a Rotating Curved Duct with Reynolds Stress Model to Automatically Sencer the Presence of a Wall (벽면감지장치를 가지는 RSM에 의한 회전하는 곡관 내 난류유동)

  • Chun, Kun-Ho;Kim, Dong-Chul;Choi, Young-Don
    • Proceedings of the KSME Conference
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    • 2000.11b
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    • pp.473-478
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    • 2000
  • In this study, the characteristics of the three-dimensional turbulent flow in a rotating square sectioned $90^{\circ}$ bend were investigated by numerical simulation and experiment. In the experimental study, the characteristics of a developing turbulent flow are measured using hot-wire anemometer to seize the rotational effects on the flow characteristics and to compare the results of computational simulation with Reynolds stress model. Each refinement is shown to lead to an appreciable improvement in the agreement between measurement and computation.

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Magnetic field detwinning in FeTe

  • Kim, Younsik;Huh, Soonsang;Kim, Jonghyuk;Choi, Youngjae;Kim, Changyoung
    • Progress in Superconductivity and Cryogenics
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    • v.21 no.4
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    • pp.6-8
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    • 2019
  • Iron-based superconductors (IBSs) possess nematic phases in which rotational symmetry of the electronic structure is spontaneously broken. This novel phase has attracted much attention as it is believed to be closely linked to the superconductivity. However, observation of the symmetry broken phase by using a macroscopic experimental tool is a hard task because of naturally formed twin domains. Here, we report on a novel detwinning method by using a magnetic field on FeTe single crystal. Detwinning effect was measured by resistivity anisotropy using the Montgomery method. Our results show that FeTe was detwinned at 2T, which is a relatively weak field compared to the previously reported result. Furthermore, detwinning effect is retained even when the field is turned off after field cooling, making it an external stimulation-free detwinning method.

Magnetic Characteristic Analysis of Permanent Magnet Motor with Complex E&S Modeling

  • Zeze, Shingo;Todaka, Takashi;Enokizono, Masato
    • Journal of international Conference on Electrical Machines and Systems
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    • v.1 no.1
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    • pp.17-22
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    • 2012
  • This paper presents analyzed results of a permanent magnet motor by using complex E&S modeling. The calculated results are compared with ones from the conventional E&S modeling for verification. Combinations of the numbers of slots and poles are investigated to reduce total iron loss. The results demonstrate that the complex E&S modeling is very useful in design under consideration of rotational magnetic field and magnetic anisotropy.

Study of Molecular Reorientation in Liquid with Raman Spectroscopy (Ⅱ) Anisotropic Rotation of$C_6F_6$ in Neat Liquid

  • Wan-In Lee;Kook-Joe Shin;Myung-Soo Kim
    • Bulletin of the Korean Chemical Society
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    • v.4 no.1
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    • pp.10-14
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    • 1983
  • Anisotropic rotation of C$_{6}$F$_{6}$ in neat liquid is investigated by the analysis of the ν$_{1}$ and ν$_{15}$ (both C-F stretching) bands of Raman spectrum and diffusion constants for the spinning (D$_{II}$) and tumbling (D$_{⊥}$) motions are obtained by the rotational dffusion theory. The same analysis is also carried out for the ν$_{2}$ and ν$_{16}$ (both C-C stretching) bands and both results are compared with the results obtained for benzene in neat liquid. The results show that the reorientation of C$_{6}$F$_{6}$ is highly anisotropic and the anisotropy is greater for C$_{6}$F$_{6}$ than benzene. This is due to the fact that the spinning rate is about the same but the tumbling rate is sharply reduced for C$_{6}$F$_{6}$.

Second Harmonic Rotational Anisotropy of Polycrystalline Fe Films on Glass Substrates (유리 위에 증착된 다결정 Fe 자성박막의 이차조화파 회전 이방성)

  • Lee, Feel;Jeong, Jae-Woo;Lee, Hun-Sung;Lee, Kyung-Dong;Kim, Ji-Wan;Shin, Sung-Chul
    • Journal of the Korean Magnetics Society
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    • v.19 no.2
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    • pp.47-51
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    • 2009
  • The surface structure of polycrystalline Fe films of various thicknesses on glass substrates have been studied using a Ti: Sapphire laser at 780 nm. We found that the surface structure possesses C$_s$ crystal structure close to $C_{2v}$ through symmetry consideration. We present one-fold intensity profile with one mirror plane in second harmonic (SH) intensity as a proof of $C_s$ symmetry. $C_s$ and $C_{2v}$ surface symmetries usually appear at the (110) surface of a cubic diamond single crystal [1]. Therefore this surface symmetry would be related to bcc (110) growth orientation coinciding with XRD measurement. Further we treated surface normalized SH asymmetry with various thicknesses. The SH asymmetry increases with increasing of film thickness. From these results, it is observed that the surface structure of thin polycrystalline Fe film below 5 nm is almost isotropic, while in the case of the thicker Fe films, surface structure have $C_s$ symmetry structure close to $C_{2v}$.