A doubly anharmonic oscillator in an induced electric dipole system

The behaviour of the interaction of the induced electric dipole moment of an atom with a uniform magnetic field and a non-uniform electric field are investigated in a rotating reference frame. An interesting aspect of this interaction is that it gives rise to an analogue of a spinless particle subject to the doubly anharmonic oscillator. Then, it is shown that analytical solutions to the Schrödinger equation can be obtained. Another point raised is that the quantum effects on the induced electric dipole moment can be observed if the uniform magnetic field possesses a discrete set of values.

Experimental verification of a control law for the position and attitude of two objects using multiple coils

This article presents a method for relative position and attitude control for reconfigurable space structures using magnetic force with a multi-dipole system. This technology can be applied to the docking phases of space structures that can restructure themselves by assembling basic structural units. The focus of this research is on current control of dipoles, which produces strong nonlinear magnetic forces, and on the development of a method to control a strong nonlinear electromagnetic system. In a previous study, the feasibility of using this method to perform relative position and attitude control was investigated by conducting a series of three-dimensional simulations of position and attitude control. In this study, experimental verification of the control method is conducted to determine whether magnetic forces can be used to correct position and attitude simultaneously. The good agreement obtained between the simulation results and the experimental results confirms the effectiveness of our proposed method.

Dynamically Induced Magnetic Moment of a Magnetic Dipole System

The systems of three and four spherical bodies with the dipole magnetic moment have been investigated using a numerical analysis. It was shown that in the initial state with the zero total magnetic moment under the influence of the alternating magnetic field, various regimes of the induced magnetic moment including quasistatic states are established. Revealed are the significant differences between these regimes related to different systems. The magnitude and direction of the magnetic moment of the system, as well the states of dynamic bistability, have been investigated. The possibilities of the induced magnetic moment control due to the changes in amplitude or frequency of the alternating field have been considered.

On the electromagnetic response of a resistive cylinder buried in a conductive host

The frequency-domain electromagnetic response of a confined conductor buried in a resistive host has received much attention, particularly in the context of mineral exploration. In contrast, the problem of the electromagnetic response of a confined resistor buried in a conductive host has been less thoroughly studied. However, resistive targets are important in geotechnical and hydrologic studies, archaeological prospecting, and, more recently, offshore hydrocarbon exploration. I analytically address the problem of the electromagnetic response of a completely resistive cylindrical cavity buried in a conductive host in the presence of a simplified 2D electric dipole source. In contrast to the confined conductor, which channels and induces current systems, the confined resistor deflects current and produces additional eddy current systems in the conductive host. I apply this theory to model the response of a grounded electric dipole-dipole system operating over a range of frequencies from 0 Hz to 10 kHz, in the presence of a horizontal 5-m radius insulating cylinder located 1-m beneath the surface of a uniform earth. This represents a common hazard encountered during mining and civil engineering operations. Results show that such an insulating cavity increases the recorded electric field amplitude and phase delay at all transmitted frequencies. These observations suggest that a broadband electromagnetic prospecting system may provide additional information about the location and extent of a void, over and above a standard dipole-dipole resistivity survey. When the host skin depth is much larger than all other length scales, the response can be approximated by an equivalent single dipole unless the cylinder’s radius is much larger than its distance from the transmitter. This result provids a useful rule of thumb to determine the acceptable range over which a resistive target can be modeled by a distribution of dipoles.

Numerical simulation of radiation, reflection, and reception of elastic waves from a borehole dipole source

A recent advance in single-well reflection imaging is the use of a dipole acoustic system in a borehole to radiate and receive elastic waves to and from a remote geologic reflector in formation. This dipole-acoustic imaging technology is evaluated by numerically simulating the radiation and reflection of the wavefield generated by the borehole dipole source and analyzing the receiving sensitivity of the dipole system to the incoming reflected waves. The analyses show that a borehole dipole source can radiate a compressional wave (P-wave) and two types of shear waves (i.e., SV- and SH-waves) into the formation. The SH-wave has wide radiation coverage and the best receiving sensitivity, and is most suitable for dipole-shear imaging. In an acoustically slow formation, the dipole-generated P-wave has strong receiving sensitivity and can also be used for reflection imaging. An important feature of dipole imaging is its sensitivity to reflector azimuth, which results from the directivity of the dipole source. By using a 4C data acquisition method to record the dipole-generated reflected signal, the reflector azimuth can be determined. The numerical simulation and theoretical analysis results are in good agreement, providing a solid foundation for the dipole acoustic imaging technology.