Here is reported the evolution of the transconductance and resistance, along with microstructure, of organic electrochemical transistors (OECTs) under progressively greater strain. A decrease in ...transconductance and increase in resistance over several orders of magnitude are reported for strains up to 75%. These changes in electrical characteristics are correlated with changes in the microstructure of the PEDOT:PSS characterised by a positive shift, and reduction in amplitude, of the characteristic (100) peak of the grazing incidence wide-angle X-ray scattering (GIWAXS) profile, recorded in tandem with the electrical characteristics during stretching. The (100) peak is associated with the lamella stacking of the PEDOT and PSS chains, and it is shown that this lamella spacing is reduced by up to around 3.5 Å on application of strain up to 75%.
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•Combined electrical and microstructure characterization of PEDOT:PSS polymer.•In-situ grazing incidence wide-angle X-ray scattering (GIWAXS) measurements of PEDOT:PSS under mechanical strain.•Study correlation between crystallised PEDOT:PSS under strain, used for Organic Electrochemical Transistor (OECT) device.•Presentation of a novel setup to allow measurement of OECT transconductance under strain while on a synchrotron beam line.
The strain distribution of a lateral nanostructure containing an InGaAs single quantum well (SQW) is studied by depth-resolved high-resolution x-ray grazing-incidence diffraction. The lateral strain ...variation is realized by patterning of an initially tensily strained InGaP stressor grown on top of the compressively strained SQW. The finite element method (FEM) is applied to the analysis of the strain distribution within the SQW induced by strain relaxation of the stressor layer. In particular, it is shown that the strain field reaches a maximum beneath the valleys and varies with the valley width. Based on the distorted wave Born approximation the experimental x-ray scattering curves were simulated using the displacements calculated by FEM as an input. We found a rather good agreement between simulation and experiment.
Cometary nature of the 1908 Tunguska cosmic body Ibodov, F. S.; Grigorian, S. S.; Ibadov, S.
Proceedings of the International Astronomical Union,
08/2009, Letnik:
5, Številka:
S263
Journal Article
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The cometary nature of the 1908 Tunguska cosmic body is compatible with the predictions of an analytical theory of the 1908 Tunguska explosion developed in 1976–1979. The theory takes into account ...the three simultaneously occurring processes, namely aerodynamic destruction of the cosmic body in the Earth's atmosphere, transversal expansion of the crushed mass under the action of pressure gradient on the frontal surface of the body, and an aerodynamic deceleration of crushed expanding mass. The use, for the mechanical parameters of the Tunguska cosmic body, of the characteristics of a cometary nuclei such as that of comet Halley 1986 III and comet Shoemaker – Levy 9 1994, gives parameters of the Tunguska explosion derived from observations of Tunguska event in the Siberian taiga in 1908.
Explosive evolution of nuclei of sungrazing comets near the solar surface, which occurs at conditions of intense interaction between the solar atmosphere and falling high-velocity comet nuclei as ...well as the relation of the phenomenon to the character of solar activity are analytically considered. It is found that, due to aerodynamic fragmentation of the falling body in the solar chromosphere and transversal expansion of the fragmented mass under the action of pressure gradient on the frontal surface, thermalization of the kinetic energy of the body occurs by sharp stopping of the disklike hypervelocity fragmented mass near the solar surface within a relatively very thin subphotospheric layer and has, therefore, an essentially impulsive and strongly explosive character. The specific energy release in the explosion region, erg/g, considerably exceeds the evaporation/sublimation heat of the body so that the process is accompanied by production of a high-temperature plasma. The energetics of such an explosive process corresponds to that of very large solar flares for falling bodies having masses equal to the mass of the nucleus of Comet Halley. Spectral observations of sungrazing comets by SOHO-like telescopes in a wide spectral range, including X rays, with a high time resolution, of the order of 0.1–10 s, are important for revealing solar activity in the form of an impact-generated photospheric flare.
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