We present the calculation of the probability production of an electron-positron pair in the presence of a strong magnetic field with time-varying strength. The calculation takes into account the presence of a strong, constant and uniform gravitational field in the same direction of the magnetic field. The results show that the presence of the gravitational field in general enhances very much t...

Weak interactions are expected to induce a parity violating pion-nucleon coupling, h (1) πNN . This coupling should be measurable in a proposed experiment to study the parity violating asymmetry Aγ in the process ~n + p → d + γ. We compute the leading dependence of Aγ on the coupling h (1) πNN using recently developed effective field theory techniques and find an asymmetry of Aγ = +0.17 h (1) π...

Tensor calculation of suffix-contraction is carried out by a C-program. Tensors are represented graphically, and the algorithm makes use of the topology of the graphs. Classical and quantum gravity, in the weak-field perturbative approach, is a special interest. Examples of the leading order calculation of some general invariants such as RμνλσR μνλσ are given. Application to Weyl anomaly calcul...

The self-extraction cyclotron is a 14 MeV H+ machine from which the beam extracts without a deflector. This is achieved with a special shaping of the magnetic field. Detailed 3D magnetostatic models have been constructed of this cyclotron, in order to accurately calculate the extraction process. Shimming of removable pole tips has been used to isochronize the machine and to remove harmonic erro...

The limitations of the Green functions method concerning nonlinear spinor theory are discussed. To remove these difficulties, functional quantum theory of the nonlinear spinor field was introduced in preceding papers. To obtain numerical values for the global observables in this theory, the functional eigenstates have to be calculated. In this paper especially for functional scattering states a...

Coaxial magnetic gears are a new breed of magnetic devices, which utilize the interaction of permanent magnet fields to enable torque transmission. Apart from using a numerical approach for their magnetic field analysis, an analytical approach is highly desirable since it can provide an insightful knowledge for design and optimization. In this paper, a new analytical approach is proposed to cal...

Diffused pneumatic silencer has been widely used in pneumatic fields because of its small dimensions and high performance on noise reduction. Numerical simulation of its interior and exterior flow field is important to studying the gas flow in the silencer and the flow structure outside the silencer, understanding the mechanism of its noise reduction. Porous media model and Darcy-Forchheimer pr...

Equivalent fields are frequently used for central axis depth-dose calculations of rectangular and irregular shaped photon beam. Since most of the proposed models to calculate the equivalent square field, are dosimetry-based, a simple physical-based method to calculate the equivalent square field size was used as the basis of this study. The table of the sides of the equivalent square for rectan...

This paper deals with the measurement of AC corona inception voltage, Vincp, at the tip of a rod electrode using a hemispherically-capped rod-plane electrode configuration for various rod radii with a short air gap. Effects of atmospheric pressure and temperature variation on Vincp are investigated experimentally. An empirical equation for the field form factors of the hemispherically cappe...