Search results for "Names"
showing 10 items of 6843 documents
Cu–Cu interactions in the transparent p-type conductors: CuAlO2 and SrCu2O2
2003
Abstract Electronic structures of the p-type Transparent Conducting Oxides (TCO): CuAlO2 and SrCu2O2 are calculated using the Tight Binding Linearized Muffin Tin Orbital within the Atomic Sphere Approximation method (TB-LMTO-ASA). The band structures indicate two gaps for CuAlO2 (an indirect one with ΔE≈0.45 eV and a direct one with ΔE≈1.25 eV) and one direct gap for SrCu2O2 (with ΔE≈2 eV). In both oxides the Cu states are dominant at the top of the valence band, close to the Fermi level and the existence of weak Cu–Cu bonding interactions is revealed through the Integrated Crystal Orbital Hamiltonian Population (ICOHP). The presence of such interactions suggests that for the hole doped oxi…
LTE-based passive radars and applications: a review
2021
This paper provides an overview of the most recent passive radars based on long-term evolution (LTE). To begin, this paper investigates the various characteristics and requirements of 4 G LTE signals for radar, taking performance aspects such as range, velocity, range resolution, and velocity resolution into account. An ambiguity function analysis is performed on a measured LTE signal using the synchronization and reference signal components to evaluate key performance parameters such as Doppler and range characteristics. We also discuss how LTE passive radar can be used in a variety of applications. The detailed analysis of the LTE downlink signal, its structural overview, and the effect o…
Finite-size scaling of charge carrier mobility in disordered organic semiconductors
2016
Simulations of charge transport in amorphous semiconductors are often performed in microscopically sized systems. As a result, charge carrier mobilities become system-size dependent. We propose a simple method for extrapolating a macroscopic, nondispersive mobility from the system-size dependence of a microscopic one. The method is validated against a temperature-based extrapolation [A. Lukyanov and D. Andrienko, Phys. Rev. B 82, 193202 (2010)]. In addition, we provide an analytic estimate of system sizes required to perform nondispersive charge transport simulations in systems with finite charge carrier density, derived from a truncated Gaussian distribution. This estimate is not limited t…
Amorphous Silicon Nanotubes via Galvanic Displacement Deposition
2013
Amorphous silicon nanotubes were grown in a single step into a polycarbonate membrane by a galvanic displacement reaction conducted in aqueous solution. In order to optimize the process, a specifically designed galvanic cell was used. SEM images, after polycarbonate dissolution, showed interconnected nanotube bundles with an average length of 18 μm and wall thickness of 38 nm.The deposited silicon was revealed by EDS analysis, whilst X-ray diffraction and Raman spectroscopy showed that nanotubes have an amorphous structure. Silicon nanotubes were also characterized by photo-electrochemical measurements that showed n-type conductivity and optical gap of ~1.6 eV. Keywords: Silicon nanotubes, …
Dynamic 2- and 3-connectivity on planar graphs
1992
We study the problem of maintaining the 2-edge-, 2-vertex-, and 3-edge-connected components of a dynamic planar graph subject to edge deletions. The 2-edge-connected components can be maintained in a total of O(n log n) time under any sequence of at most O(n) deletions. This gives O(log n) amortized time per deletion. The 2-vertex- and 3-edge-connected components can be maintained in a total of O(n log2n) time. This gives O(log2n) amortized time per deletion. The space required by all our data structures is O(n).
<title>Stereovision studies by disbalanced images</title>
2003
Studies are focused on design and appraisal of an objective test of the quality of stereovision depending on optical stimuli blurring and detecting of the stereovision threshold at various stimuli blur degree. The method is based on the principles of grayscale and color random dot stereotests. Experiments may be divided with respect to the principle of demonstration: 1) the blur is modeled by defocusing an optical lens - the strength of the optical system is varied at a constant quality of the stimulus, or 2) the blur is simulated on the computer screen - here the quality of the stimulus varies. To obtain an independent description and to measure blurring the experimentally demonstrated ima…
The use of Stokes-Mueller polarimetry for assessment of amyloid-β progression in a mouse model of Alzheimer’s disease
2020
Abstract Alzheimer’s disease, being a major societal burden, demands improvement of current techniques for its treatment and diagnostics. Currently only autopsy histology is able to provide the definite diagnosis for Alzheimer’s disease. However, the procedure is rather time consuming and costly. In the current study, we utilized Stokes and Mueller polarimetry techniques to screen for amyloid-β (Aβ) deposits in formalin-fixed, paraffin-embedded mouse brain tissue at different stages of Alzheimer’s disease. The study has shown that the presence of Aβ plaques influences the properties of scattered polarized light. The Poincaré sphere was used as a graphical tool for the visualization of the a…
Decoding vibrational states of Concanavalin A amyloid fibrils.
2015
International audience; Amyloid and amyloid-like fibrils are a general class of protein aggregates and represent a central topic in life sciences for their involvement in several neurodegenerative disorders and their unique mechanical and supramolecular morphological properties. Both their biological role and their physical properties, including their high mechanical stability and thermodynamic inertia, are related to the structural arrangement of proteins in the aggregates at molecular level. Significant variations may exist in the supramolecular organization of the commonly termed cross-β structure that constitutes the amyloid core. In this context, a fine knowledge of the structural deta…
K-means Clustering to Study How Student Reasoning Lines Can Be Modified by a Learning Activity Based on Feynman’s Unifying Approach
2017
Background:Research in Science Education has shown that often students need to learn how to identify differences and similarities between descriptive and explicative models. The development and use of explicative skills in the field of thermal science has always been a difficult objective to reach. A way to develop analogical reasoning is to use in Science Education unifying conceptual frameworks.Material and methods:A questionnaire containing six open-ended questions on thermally activated phenomena was administered to the students before instruction. A second one, similar but focused on different physical content was administered after instruction. Responses were analysed using k-means Cl…
Error estimation and reduction with cross correlations
2010
Besides the well-known effect of autocorrelations in time series of Monte Carlo simulation data resulting from the underlying Markov process, using the same data pool for computing various estimates entails additional cross correlations. This effect, if not properly taken into account, leads to systematically wrong error estimates for combined quantities. Using a straightforward recipe of data analysis employing the jackknife or similar resampling techniques, such problems can be avoided. In addition, a covariance analysis allows for the formulation of optimal estimators with often significantly reduced variance as compared to more conventional averages.