Structural and thermal analyses in semiconducting and metallic zigzag single-walled carbon nanotubes using molecular dynamics simulations.

Equilibrium molecular dynamics (EMD) simulations have been performed to investigate the structural analysis and thermal conductivity (λ) of semiconducting (8,0) and metallic (12,0) zigzag single-walled carbon nanotubes (SWCNTs) for varying ±Î³(%) strains. For the first time, the present outcomes provide valuable insights into the relationship between the structural properties of zigzag SWCNTs and corresponding thermal behavior, which is essential for the development of high-performance nanocomposites. The radial distribution function (RDF) has been employed to assess the buckling and deformation understandings of the (8,0) and (12,0) SWCNTs for a wide range of temperature T(K) and varying ±Î³(%) strains. The visualization of SWCNTs shows that the earlier buckling and deformation processes are observed for semiconducting SWCNTs as compared to metallic SWCNTs for high T(K) and it also evident through an abrupt increase in RDF peaks. The RDF and visualization analyses demonstrate that the (8,0) SWCNTs can more tunable under compressive than tensile strains, however, the (12,0) zigzag SWCNTs indicate an opposite trend and may tolerate more tensile than compressive strains. Investigations show that the tunable domain of ±Î³(%) strains decreases from (-10%≤ γ ≤+19%) to (-5%≤ γ ≤+10%) for (8,0) SWCNTs and the buckling process shifts to lower ±Î³(%) for (12,0) SWCNTs with increasing T(K). For intermediate-high T(K), the λ(T) of (12,0) SWCNTs is high but the (8,0) SWCNTs show certainly high λ(T) for low T(K). The present λ(T, ±Î³) data are in reasonable agreement with parts of previous NEMD, GK-HNEMD data and experimental investigations with simulation results generally under predicting the λ(T, ±Î³) by the ∼1% to ∼20%, regardless of the ±Î³(%) strains, depending on T(K). Our simulation data significantly expand the strain range to -10% ≤ γ ≤ +19% for both zigzag SWCNTs, depending on temperature T(K). This extension of the range aims to establish a tunable regime and delve into the intrinsic characteristics of zigzag SWCNTs, building upon previous work.

Novel stochastic dynamics of a fractal-fractional immune effector response to viral infection via latently infectious tissues.

In this paper, the global complexities of a stochastic virus transmission framework featuring adaptive response and Holling type II estimation are examined via the non-local fractal-fractional derivative operator in the Atangana-Baleanu perspective. Furthermore, we determine the existence-uniqueness of positivity of the appropriate solutions. Ergodicity and stationary distribution of non-negative solutions are carried out. Besides that, the infection progresses in the sense of randomization as a consequence of the response fluctuating within the predictive case's equilibria. Additionally, the extinction criteria have been established. To understand the reliability of the findings, simulation studies utilizing the fractal-fractional dynamics of the synthesized trajectory under the Atangana-Baleanu-Caputo derivative incorporating fractional-order α and fractal-dimension ℘ have also been addressed. The strength of white noise is significant in the treatment of viral pathogens. The persistence of a stationary distribution can be maintained by white noise of sufficient concentration, whereas the eradication of the infection is aided by white noise of high concentration.

Computational study of electronic properties of X-doped hexagonal boron nitride (h-BN): X = (Li, Be, Al, C, Si).

The structural and electronic properties of h-BN sheet implanted with X atoms (X = lithium (Li), beryllium (Be), aluminum (Al), carbon (C), and silicon (Si)) have been investigated to tune its band gap to amend its insulating behavior toward semiconducting material employing density functional theory (DFT). It has been observed that on replacing nitrogen or boron (N/B) atom with impurity atom, several impurity levels appear in band gap dividing big gap into small energy gaps, albeit to a different extent, depending upon the dopant element and substitutional site. The lowest value of band gap falls as low as 2.27 eV as compared to 4.63 eV of pristine h-BN in addition to the appearance of states at the Fermi level. Additionally; geometrical, interaction of foreign elements with the host material, and stability issues are discussed. These results are affable for its usage in transistor-based devices and to explore its new applications in high-power electronic and optoelectronic devices.

Effect of copper concentration and sulfur vacancies on electronic properties of MoS2 monolayer: a computational study.

We investigated the geometrical and electronic properties of copper-doped MoS2 by first principles calculations. The doping is done by Cu substitution with Mo (1 to 4 atoms) accompanied by study of S vacancies. Our outcomes show that the concentration of doping and vacancy of S leads to determine and finely tune the band gap in the range of 0.16 to 1.95 eV. This fine tuning of band gap results due to variation in concentration of impurity, changing dopant site, and production of S vacancies. The resulting arrangements show significant charge redistribution on replacement of local atoms with foreign atoms dictated by electronegativity determined from the Bader analysis. In addition, bonding mechanism occurring due to substitution of foreign elements is discussed. These results give pleasing data regarding fine desired value of the band gap of the MoS2 which helps its utilization in semiconductor and other opto-electronic devices in addition to understanding the electrical conductivity.

Computational study of X-doped hexagonal boron nitride (h-BN): structural and electronic properties (X = P, S, O, F, Cl).

Hexagonal boron nitride (h-BN), with insulating band gap (> 6 eV) 2D material, has attracted extensive attentions. To discover potential applications in optoelectronic devices, modulation in electrical conductivity (n or p type) plays a significant role. In this paper, the structural and electronic properties of energetically stable doped boron nitride monolayer via ab initio calculations have been reported. Our basic focus is on fine tuning of the band gap with replacement of a number of elements by varying the dopant site. Our results show the opportunity to induce a reduced band gap values with smaller concentration of dopants, and also show many interesting physical properties with better structural stabilities, in X-doped BN sheet (X = P, S, O, F, Cl).