| 1. |
- Choi, A., et al.
(author)
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Suppression of the magneto resistance in high electric fields of polyacetylene nanofibers
- 2010
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In: SYNTHETIC METALS. - 0379-6779. ; 160:11-12, s. 1349-1353
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Journal article (peer-reviewed)abstract
- We present results of non-linear magneto resistance (MR) of polyacetylene nanofibers in high magnetic field up to H = 30 T at low temperature T = 1.5 K. The MR was proven to be of the spin origin; it reaches 16% at highest H. Unexpectedly, the MR was suppressed by increasing electric field E, vanishing at E ≳ 5 × 104 V/cm. It is understood that the doping induced spinless charged soliton pairs, which are initially confined to a certain distance because of the interchain phase correlations, and are deconfined in high electric fields, resulting in a vanishing magneto resistance (VMR). The role of the specific, degenerate ground state of the polyacetylene is confirmed by parallel studies of the different magneto resistances of polyaniline nanofibers which contrarily is not affected by the electric field. © 2010 Elsevier B.V. All rights reserved.
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| 2. |
- Singh, R, et al.
(author)
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A semi-analytic power balance model for low (L) to high (H) mode transition power threshold
- 2014
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In: Physics of Plasmas. - : AIP Publishing. - 1089-7674 .- 1070-664X. ; 21:6, s. 062503-
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Journal article (peer-reviewed)abstract
- We present a semi-analytic model for low (L) to high (H) mode transition power threshold (P-th). Two main assumptions are made in our study. First, high poloidal mode number drift resistive ballooning modes (high-m DRBM) are assumed to be the dominant turbulence driver in a narrow edge region near to last closed flux surface. Second, the pre-transition edge profile and turbulent diffusivity at the narrow edge region pertain to turbulent equipartition. An edge power balance relation is derived by calculating the dissipated power flux through both turbulent conduction and convection, and radiation in the edge region. P-th is obtained by imposing the turbulence quench rule due to sheared E x B rotation. Evaluation of P-th shows a good agreement with experimental results in existing machines. Increase of P-th at low density (i.e., the existence of roll-over density in P-th vs. density) is shown to originate from the longer scale length of the density profile than that of the temperature profile.
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| 3. |
- Jhang, SungHo, et al.
(author)
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Random telegraph noise in carbon nanotubes and peapods
- 2006
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In: Current Applied Physics. - : Elsevier BV. - 1567-1739. ; 6, s. 987-991
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Journal article (peer-reviewed)abstract
- The switching of resistance between two discrete values, known as random telegraph noise (RTN), was observed in individual single-walled carbon nanotubes (SWNTs) and C60-filled SWNTs (the so-called peapods). The RTN has been studied as a function of bias-voltage and gate-voltage as well as temperature. By analyzing the features of the RTN, we identify three different types of RTN existing in the SWNT related systems. While the RTN can be generated by the various charge traps in the vicinity of the SWNTs, the RTN for metallic SWNTs is mainly due to reversible defect motions between two metastable states, activated by inelastic scattering with ballistic electrons. On the other hand, the noise for peapods can be attributed to the motion of C60 molecules in hollow space of SWNTs.
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| 4. |
- Jovanović, Veljko, et al.
(author)
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The Satisfaction with Life Scale in Adolescent Samples : Measurement Invariance across 24 Countries and Regions, Age, and Gender
- 2022
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In: Applied Research in Quality of Life. - : Springer Science and Business Media LLC. - 1871-2584 .- 1871-2576. ; 17:4, s. 2139-2161
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Journal article (peer-reviewed)abstract
- Measurement of adolescent life satisfaction across cultures has not received much attention in previous empirical research. The present study evaluated measurement invariance of the Satisfaction with Life Scale (SWLS) among adolescents in 24 countries and regions (N = 22,710; age range = 13–19 years; 53% female). A single-factor model with residual covariance between a pair of items tapping past life satisfaction fitted well in 19 countries and regions and showed a partial metric invariance. In a subset of nine countries and regions, partial scalar invariance was supported. Partial metric invariance across all 24 countries and regions was achieved when custom model modifications in five countries and regions were included. Three SWLS items showed evidence of noninvariance across cultures. The measurement model was found to operate similarly across gender and age. Our findings suggest that caution is needed when using the SWLS for measuring life satisfaction among adolescents from different cultures.
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| 5. |
- Lee, DongSu, et al.
(author)
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Extraction of semiconducting carbon nanotubes by repeated dielectrophoretic filtering
- 2005
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In: Applied Physics A. - : Springer Science and Business Media LLC. - 0947-8396 .- 1432-0630. ; 80, s. 5-8
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Journal article (peer-reviewed)abstract
- We have separated semiconducting carbon nanotubes from as-grown batch material (HiPco production). A special configuration of electrodes which generates a 3-dimensional electric field gradient was used to filter out and deposit metallic carbon nanotubes by the dielectrophoretic method, leaving the remaining dispersion enriched in semiconducting nanotubes. The efficiency of filtering was determined by Raman spectroscopy. Using repeated deposition cycles, the ratio of semiconducting to metallic tubes was increased. After seven cycles, the proportion of semiconducting tubes in the remaining dispersion reached 94%.
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