Current-voltage (I-V) characteristics of armchair graphene nanoribbons under uniaxial strain

The current-voltage (I-V) characteristics of armchair graphene nanoribbons under a local uniaxial tension are investigated by using first principles quantum transport calculations. It is shown that for a given value of bias-voltage, the resulting current depends strongly on the applied tension. The observed trends are explained by means of changes in the band gaps of the nanoribbons due to the applied uniaxial tension. In the course of plastic deformation, the irreversible structural changes and derivation of carbon monatomic chains from graphene pieces can be monitored by two-probe transport measurements.Comment: please see the published version at http://prb.aps.org/abstract/PRB/v81/i20/e20543

Determination of the steady state response of viscoelastically supported rectangular specially orthotropic plates with varying supported area

The influence of the amount of the supported area on the free and forced vibration properties of anisotropic plate is presented. Using the energy based finite difference method, the problem is modelled by a kind of finite difference element. Due to the significiance of the fundamental frequency of the plate, its variation was investigated with respect to the amount of the supported area on the plate, mechanical properties of plate material and translational spring coefficient of supports. The steady state response of viscoelastically supported plates was also investigated numerically for various damping coefficients and amounts of supported areas. Numerical results are obtained to investigate the effect of the ratio of the plate system. In the numerical examples, the natural frequency parameters and steady state responses to a sinusoidally varying force are assessed for the fundamental mode. Results showing effect of supported area ratios of plate indicate that variation of ratio of supported area of plate system is very significiant. Convergence studies are made. Many new results have been presented. Considered problems are solved within the frame work of Kirchhoff-Love hypothesis

Metal nanoring and tube formation on carbon nanotubes

The structural and electronic properties of aluminum covered single wall carbon nanotubes (SWNT) are studied from first-principles for a large number of coverage. Aluminum-aluminum interaction that is stronger than aluminum-tube interaction, prevents uniform metal coverage, and hence gives rise to the clustering. However, a stable aluminum ring and aluminum nanotube with well defined patterns can also form around the semiconducting SWNT and lead to metallization. The persistent current in the Al nanoring is discussed to show that a high magnetic field can be induced at the center of SWNT.Comment: Submitted to Physical Review

Moving object detection using adaptive subband decomposition and fractional lower order statistics in video sequences

Cataloged from PDF version of article.In this paper, a moving object detection method in video sequences is described. In the 3rst step, the camera motion is eliminated using motion compensation. An adaptive subband decomposition structure is then used to analyze the motion compensated image. In the “low–high” and “high–low” subimages moving objects appear as outliers and they are detected using a statistical detection test based on fractional lower-order statistics. It turns out that the distribution of the subimage pixels is almost Gaussian in general. On the other hand, at the object boundaries the distribution of the pixels in the subimages deviates from Gaussianity due to the existence of outliers. By detecting the regions containing outliers the boundaries of the moving objects are estimated. Simulation examples are presented. (C) 2002 Elsevier Science B.V. All rights reserved

Antibacterial activity and composition of the essential oils of two endemic Salvia sp. from Turkey

Water-distilled essential oils from dried aerial parts of Salvia cryptantha and Salvia heldreichiana (Lamiaceae), endemic in Turkey, were analysed using gas chromatography-mass spectrometry (GCMS). Camphor (19.1%), 1,8-cineole (16.4%), borneol (11.9%), viridiflorol (11.5%) and bornyl acetate (2.4%) were found to be the major constituents in the oil of S. cryptantha. The major constituents in the oil of S. heldreichiana were linalool (9.4%), a-pinene (5.6%), 1,8-cineole (5.6%), borneol (5.6%), cryptone (5.3%), linalyl acetate (4.9%), a-terpineol (4.4%), camphor (3.9%), terpinen-4-ol (3.3%), trans-linalool oxide (Furanoid) (2.9%), trans-verbenol (2.2%), geranyl acetate (2.2%) and cis-linalool oxide (Furanoid) (2.1%). Essential oil of S. heldreichiana exhibited antimicrobial activity using the disc diffusion method against Escherichia coli, Sarcinia lutea and Salmonella typhimurium. The oil of S. cryptantha inhibited the growth of S. lutea

How Do You Like Me in This: User Embodiment Preferences for Companion Agents

We investigate the relationship between the embodiment of an artificial companion and user perception and interaction with it. In a Wizard of Oz study, 42 users interacted with one of two embodiments: a physical robot or a virtual agent on a screen through a role-play of secretarial tasks in an office, with the companion providing essential assistance. Findings showed that participants in both condition groups when given the choice would prefer to interact with the robot companion, mainly for its greater physical or social presence. Subjects also found the robot less annoying and talked to it more naturally. However, this preference for the robotic embodiment is not reflected in the users’ actual rating of the companion or their interaction with it. We reflect on this contradiction and conclude that in a task-based context a user focuses much more on a companion’s behaviour than its embodiment. This underlines the feasibility of our efforts in creating companions that migrate between embodiments while maintaining a consistent identity from the user’s point of view

CIDI-Lung-Seg: A Single-Click Annotation Tool for Automatic Delineation of Lungs from CT Scans

Accurate and fast extraction of lung volumes from computed tomography (CT) scans remains in a great demand in the clinical environment because the available methods fail to provide a generic solution due to wide anatomical variations of lungs and existence of pathologies. Manual annotation, current gold standard, is time consuming and often subject to human bias. On the other hand, current state-of-the-art fully automated lung segmentation methods fail to make their way into the clinical practice due to their inability to efficiently incorporate human input for handling misclassifications and praxis. This paper presents a lung annotation tool for CT images that is interactive, efficient, and robust. The proposed annotation tool produces an "as accurate as possible" initial annotation based on the fuzzy-connectedness image segmentation, followed by efficient manual fixation of the initial extraction if deemed necessary by the practitioner. To provide maximum flexibility to the users, our annotation tool is supported in three major operating systems (Windows, Linux, and the Mac OS X). The quantitative results comparing our free software with commercially available lung segmentation tools show higher degree of consistency and precision of our software with a considerable potential to enhance the performance of routine clinical tasks.Comment: 4 pages, 6 figures; to appear in the proceedings of 36th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC 2014

Inhomogeneous DNA: conducting exons and insulating introns

Parts of DNA sequences known as exons and introns play very different role in coding and storage of genetic information. Here we show that their conducting properties are also very different. Taking into account long-range correlations among four basic nucleotides that form double-stranded DNA sequence, we calculate electron localization length for exon and intron regions. Analyzing different DNA molecules, we obtain that the exons have narrow bands of extended states, unlike the introns where all the states are well localized. The band of extended states is due to a specific form of the binary correlation function of the sequence of basic DNA nucleotides.Comment: 14 pages, 6 figure

Tsallis Ensemble as an Exact Orthode

We show that Tsallis ensemble of power-law distributions provides a mechanical model of nonextensive equilibrium thermodynamics for small interacting Hamiltonian systems, i.e., using Boltzmann's original nomenclature, we prove that it is an exact orthode. This means that the heat differential admits the inverse average kinetic energy as an integrating factor. One immediate consequence is that the logarithm of the normalization function can be identified with the entropy, instead of the q-deformed logarithm. It has been noted that such entropy coincides with Renyi entropy rather than Tsallis entropy, it is non-additive, tends to the standard canonical entropy as the power index tends to infinity and is consistent with the free energy formula proposed in [S. Abe et. al. Phys. Lett. A 281, 126 (2001)]. It is also shown that the heat differential admits the Lagrange multiplier used in non-extensive thermodynamics as an integrating factor too, and that the associated entropy is given by ordinary nonextensive entropy. The mechanical approach proposed in this work is fully consistent with an information-theoretic approach based on the maximization of Renyi entropy.Comment: 5 pages. Added connection with Renyi entrop