Heavy-Light Mesons in the Nonrelativistic Quark Model Using Laplace Transformation Method

An analytic solution of the N-dimensional radial Schrödinger equation with the combination of vector and scalar potentials via the Laplace transformation method (LTM) is derived. The current potential is extended to encompass the spin hyperfine, spin-orbit, and tensor interactions. The energy eigenvalues and the corresponding eigenfunctions have been obtained in the N-dimensional space. The present results are employed to study the different properties of the heavy-light mesons (HLM). The masses of the scalar, vector, pseudoscalar, and pseudovector for B, Bs, D, and Ds mesons have been calculated in the three-dimensional space. The effect of the dimensional number space is discussed on the masses of the HLM. We observed that the meson mass increases with increasing dimensional space. The decay constants of the pseudoscalar and vector mesons have been computed. In addition, the leptonic decay widths and branching ratio for the B+, D+, and Bs+ mesons have been studied. Therefore, the used method with the current potential gives good results which are in good agreement with experimental data and are improved in comparison with recent theoretical studies.

A New Mathematical Model For Heat Radius of Cyclic Superheated Steam Stimulation with Horizontal Wellbore

When superheated steam flows along the horizontal wellbore, it may change to saturated steam at some point of the wellbore. In this paper, to accurately predict the heat radius of cyclic superheated steam stimulation with horizontal wellbore, the distribution of thermophysical properties of superheated steam along the horizontal wellbore is considered. The heating process is divided into 4 stages for superheated steam and 3 stages for saturated steam when the phase change undergoes in the wellbore. On this basis, the mathematical model for heat radius of cyclic superheated steam stimulation with horizontal wellbore was established according to energy conservation principle and Laplace transformation method. The calculation result of the new mathematical model is in good agreement with that of the numerical simulation (CMG STARS) for the same parameters from a specific heavy oil reservoir, which verified the correctness of the new mathematical model. The effect of degree of superheat and the cycle of stimulation are analyzed in detail after the new mathematical model is validated. The results show that the heat radius of superheated zone, steam zone, and hot fluid zone all decrease with horizontal well length and increase with the cycle of stimulation. The higher the degree of superheat is, the farther from the heel of the horizontal wellbore the phase change undergoes. Besides, the radius of superheated zone, steam zone, and hot fluid zone increases with the degree of superheat, but the value increases little at steam zone and hot fluid zone.

Thermoelastic response of a one-dimensional semi-infinite rod heated by a moving laser pulse

In the present study, thermoelastic behavior of a semi-infinite rod, which is subjected to a time exponentially decaying laser pulse, is formulated. The rod is free at the left end and the laser pulse moves along the axial direction from the left end. The non-Fourier effect of the heat conduction equation is considered and the Laplace transformation method is employed in solving the governing equations. The temperature, displacement, strain, and stress in the rod are derived and the distributions of the parameters at different positions are analyzed. Also the influence of the laser speed is investigated.

Laplace-Weighted Residual Method For Problems with Semi-Infinite Domain

This paper presents an efficient numerical method for the approximate solution of problems involving boundary condition at infinity. The whole idea of the method is based on the combination of Laplace transformation method and weighted residual method. Numerical examples are given to show the validity and applicability of the proposed method and the results obtained are compared with other methods in the literatures.

Two-Temperature Generalized Thermo-Elastic Medium Thermally Excited by Time Exponentially Decaying Laser Pulse

This paper deals with a two-temperature thermoelastic material subjected to a laser heating pulse as the heat source. Closed form solutions for the temperature and stress fields due to time exponentially decaying laser pulse are presented using the state-space approach. The Laplace transformation method is employed in deriving the governing equations. The inversion of Laplace transform is obtained numerically by using the Riemann-sum approximation method. The results have been presented in figures to show the effect of the time exponentially decaying laser pulse, the two-temperature parameter and the absorption coefficient on all the fields studied. The results show that the two-temperature parameter and the absorption coefficient parameter have significant effects on all the field parameters studied.

Investigation for Synchronization of a Rotor-Pendulum System considering the Multi-DOF Vibration

This work is a continuation for our published literature for vibration synchronization. A new mechanism, two rotors coupled with a pendulum rod in a multi-DOF vibration system, is proposed to implement coupling synchronization, and the dynamics equation of mechanism is derived by Lagrange equation. In addition, the coupling relationship between the vibrobody and the pendulum rod is ascertained with the Laplace transformation method, based on the dimensionless equation of the dynamics system. The Poincare method is employed to study the synchronization state between the two unbalanced rotors, which is converted into that of existence and the stability of solutions for synchronization-balance equations. The obtained results are supported by computer simulations. It is demonstrated that the values of the spring stiffness coefficient, the length of the pendulum, and the angular installation of the pendulum are important parameters with respect to the synchronous behavior in the rotor-pendulum system.

Thermoelastic Vibration of an Axially Moving Microbeam Subjected to Sinusoidal Pulse Heating

This paper develops the solution for the generalized thermoelastic vibration of an axially moving microbeam resonator induced by sinusoidal pulse heating. The system of governing equations is reduced to a novel six-order thermoelastic differential equation in terms of either deflection or temperature. The Laplace transformation method is used to determine the deflection, temperature, axial displacement, and bending moment of the microbeam. The effects of phase-lag and width of the sinusoidal pulse are studied and represented graphically. The effect of the moving speed on the microbeam resonator is also investigated.