Characteristics of Carbon Nanotubes Synthesized from Methane and Acetylene in the Presence of a FeCl3 Catalyst

Technical Physics - The structures of carbon nanotubes synthesized by catalytic CVD in the same reactor using different carbon-containing precursors and a FeCl3 catalyst have been compared. Methane...     

Complete cosmological model based on an asymmetric scalar Higgs doublet

Theoretical and Mathematical Physics - We study a complete cosmological model based on an asymmetric scalar doublet represented by the classical and phantom scalar Higgs fields. Moreover, we remove...     

Model Waveforms of Slow-Tail Sferics

Radiophysics and Quantum Electronics - We simulate numerically the propagation of slow-tail sferics, which occupy a wide frequency band from 1 Hz to 10 kHz, in the spherical Earth–ionosphere...     

On the Nonlocal Darboux Transformation for Time-Independent Axially Symmetric Schrödinger and Helmholtz Equations

JETP Letters - The nonlocal Darboux transformation for the time-independent axially symmetric Schrödinger and Helmholtz equations has been considered. New examples of two-dimensional...     

Scattering Indicatrix of Aqueous Hemoglobin Solutions

Journal of Applied Spectroscopy - Aqueous solutions of human hemoglobin have been studied by the multi-angle static light scattering method. The tendency of sickle-shaped erythrocytes to aggregate...     

Wavelet method for steady state immobilized enzyme kinetic model: an operational matrix approach

Journal of Mathematical Chemistry - This paper discusses a mathematical model of the diffusion and reaction in amperometric biosensor response with immobilized enzyme electrodes within a uniform...     

Physical Evidence of Stress-Induced Conformational Changes in Polymers

Background

Polymer mechanics and characterization is an active area of research where a keen effort is directed towards gaining a predictive and correlative relationship between the applied loads and the specific conformational motions of the macromolecule chains.

Objective

Therefore, the objective of this research is to introduce the preliminary results based on a novel technique to in situ probe the mechanical properties of polymers using non-invasive, non-destructive, and non-contact terahertz spectroscopy.

Methods

A dielectric elastomer actuator (DEA) structure is used as the loading mechanism to avoid obscuring the beam path of transmission terahertz time-domain spectroscopy. In DEAs, the applied voltage results in mechanical stresses under the active electrode area with far-reaching stretching in the passive area. Finite element analysis is used to model and simulate the DEA to quantify the induced stresses at the observation site over a voltage range spanning from 0 V to 3000 V. Additionally, a novel analysis technique is introduced based on the Hilbert-Huang transform to exploit the time-domain signals of the ultrathin elastomeric film and to defy the limits set forth by the current state-of-the-art analysis techniques.

Results

The computational result shows a nonlinear relationship between the effective stresses and the applied voltage. Analysis of the terahertz time-domain signals shows a shift in the delay times and a decrease in signal peak amplitudes, whereas these characteristics are implicitly related to the change in the index of refraction.

Conclusions

In all, the results evidentially signify the interrelationship between the conformational changes and applied mechanical stress.

     

Nanocomposites Based on Poly(Amide-Imide) Matrix with Na–Mg Triple Chain Hydrosilicate

Crystallography Reports - A new polymer-inorganic nanocomposite composed of fibrous Na–Mg triple chain hydrosilicate with a poly(amide-imide) matrix was developed. Its structure, morphology,...     

Tellurium Nanostructures Obtained by Thermal Evaporation Method

Crystallography Reports - Tellurium (Te) nanostructures have been obtained on glassy carbon substrates by thermal evaporation in an argon atmosphere. The sizes and shape of Te particles have been...     

Intense Infrared Laser-Induced Radiation–Collision Involvement of Molecules That Do Not Absorb Laser Radiation in Resonance with a Laser Field in a Two-Component Molecular Medium

JETP Letters - Effective radiation–collision involvement of molecules that do not absorb laser radiation in resonance with a laser field in a two-component molecular medium that includes...