Influence of defect-induced deformations on electron transport in carbon nanotubes

We theoretically investigate the influence of defect-induced long-range deformations in carbon nanotubes on their electronic transport properties. To this end we perform numerical ab-initio calculations using a density-functional-based tight-binding (DFTB) model for various tubes with vacancies. The geometry optimization leads to a change of the atomic positions. There is a strong reconstruction of the atoms near the defect (called "distortion") and there is an additional long-range deformation. The impact of both structural features on the conductance is systematically investigated. We compare short and long CNTs of different kinds with and without long-range deformation. We find for the very thin (9,0)-CNT that the long-range deformation additionally affects the transmission spectrum and the conductance compared to the short-range lattice distortion. The conductance of the larger (11,0)- or the (14,0)-CNT is overall less affected implying that the influence of the long-range deformation decreases with increasing tube diameter. Furthermore, the effect can be either positive or negative depending on the CNT type and the defect type. Our results indicate that the long-range deformation must be included in order to reliably describe the electronic structure of defective, small-diameter zigzag tubes.Comment: Materials for Advanced Metallization 201

What Makes Doxing Good or Bad? Exploring Bystanders’ Appraisal and Responses to the Malicious Disclosure of Personal Information

Doxing, the disclosure of an individual’s personal information with malicious intent, has emerged as a global phenomenon aimed at punishing, threatening, or silencing individuals. The response from the public and media to doxing varies widely, ranging from condemning it as a harmful practice that disregards the fundamental right to privacy to regarding it as a means to hold wrongdoers accountable. However, research on how and why individuals observing a doxing incident (i.e., bystanders) form their opinions is scant. This study focuses on bystanders’ appraisal of and reactions to doxing incidents. Drawing on a qualitative vignette study (n=14) employing two doxing scenarios (person-based and issue-based), we identify crucial factors that influence bystanders’ evaluation of doxing attacks. Additionally, our research sheds light on the motivations and circumstances that prompt bystanders to take action when witnessing a doxing incident. The findings of this study have important implications for both research and practice

Memory difference control of unknown unstable fixed points: Drifting parameter conditions and delayed measurement

Difference control schemes for controlling unstable fixed points become important if the exact position of the fixed point is unavailable or moving due to drifting parameters. We propose a memory difference control method for stabilization of a priori unknown unstable fixed points by introducing a memory term. If the amplitude of the control applied in the previous time step is added to the present control signal, fixed points with arbitrary Lyapunov numbers can be controlled. This method is also extended to compensate arbitrary time steps of measurement delay. We show that our method stabilizes orbits of the Chua circuit where ordinary difference control fails.Comment: 5 pages, 8 figures. See also chao-dyn/9810029 (Phys. Rev. E 70, 056225) and nlin.CD/0204031 (Phys. Rev. E 70, 046205