Matter wave soliton bouncer

Dynamics of a matter wave soliton bouncing on the reflecting surface (atomic mirror) under the effect of gravity has been studied by analytical and numerical means. The analytical description is based on the variational approach. Resonant oscillations of the soliton's center of mass and width, induced by appropriate modulation of the atomic scattering length and the slope of the linear potential are analyzed. In numerical experiments we observe the Fermi type acceleration of the soliton when the vertical position of the reflecting surface is periodically varied in time. Analytical predictions are compared with the results of numerical simulations of the Gross-Pitaevskii equation and qualitative agreement between them is found.Comment: 8 pages, 5 figure

Hydrogen production from phenol steam reforming over Ni-Co/ZrO2 catalyst: effect of catalyst dilution

This study looked into the hydrogen production from phenol steam reforming over Zirconia (ZrO2)-supported nickel-cobalt catalysts diluted with silicon carbide (SiC). The objective of this study is to obtain the effect of catalyst dilution on hydrogen production and the phenol conversion in various SiC dilutions. The catalysts were prepared by impregnation method and their performance tests were carried out in a micro fixed bed reactor at atmospheric pressure and 800 °C temperature, feed flow rate 0.36 mL/min, weight of catalyst 0.2 g, and dilution range of 0.05 to 0.35 g (1:0 to 1:1.75). The results showed that the catalyst dilution does not affect much on the catalyst activity toward phenol conversion. However, it does improve the conversion of phenol with the presence of SiC. The maximum conversion was at 0.3 g (1:1.5) SiC dilution, which was of 98.9 % and 0.6 mole fraction of hydrogen

Soliton-like Solution on the Dynamics of Modified Peyrard-Bishop DNA Model in the Thermostat as a Bio-Fluid

The Peyrard-Bishop (PB) DNA model is the most representative model to investigate DNA dynamics because the model is able to answer DNA denaturation processes even though the model has restricted review that DNA assumes without surrounding interaction. In this study, we investigate the dynamics of the modified PB DNA model by considering DNA in the Nosé-Hoover thermostat as a bio-fluid with various viscosities. Viscosity variations are reviewed through temperature variations, namely thermal viscosity. We attain the dynamical equation of DNA in the form of a nonlinear Schrödinger-like (NLS-like) equation by using the perturbation method and continuous approximation. We solve the NLS-like equations by the numerical split-step Fourier method. We obtain a soliton-like solution for the dynamics of this specific DNA model. The behavior of the soliton-like solution fluctuates as the temperature increases, representing the fluctuational openings of DNA, i.e., denaturation bubbles. In addition, that behavior also evolves with variations of the perturbation parameter. Moreover, we obtain soliton-like solutions by balancing the perturbation and the nonlinearity of the DNA system from the bio-fluid interaction. Furthermore, for the specific thermal viscosity of bio-fluid, we gain the denaturation temperature at 370 K ≤ T ≤ 380 K. Doi: 10.28991/ESJ-2022-06-04-01 Full Text: PD