Modeling the Influence of the Edge Electrostatic Effect on the Transformation Function of Thin-Film Quasi-Differential Capacitive Sensitive Elements

Capacitive sensing elements are the main components of capacitive measuring transducers, which determine most of the metrological characteristics and operational parameters of sensors. First of all, capacitive sensing elements ensure the temporal and parametric stability of sensors, which are the main operational characteristics in such areas as rocket and space and aviation technology, the nuclear industry, in which the instability of sensors and measuring systems based on them can lead to high financial and human losses. etc. At the same time, compensation for lateral capacitive couplings and electrostatic leaks are very important issues, since small changes in capacitance when measuring physical quantities can lead to uninformative measurements in the presence of distortion of electrostatic fields in a capacitive sensing element. In this regard, it is necessary to take into account and simulate the stray fields of electrostatic fields and their influence on measurements.

The Hybrid FEM-DBCI for the Solution of Open-Boundary Low-Frequency Problems

This paper describes a particular use of the hybrid FEM-DBCI, for the computation of low-frequency electromagnetic fields in open-boundary domains. Once the unbounded free space enclosing the system has been truncated, the FEM is applied to the bounded domain thus obtained, assuming an unknown Dirichlet condition on the truncation boundary. An integral equation is used to express this boundary condition in which the integration surface is selected in the middle of the most external layer of finite elements, very close to the truncation boundary, so that the integral equation becomes quasi-singular. The method is described for the computation of electrostatic fields in 3D and of eddy currents in 2D, but it is also applicable to the solution of other kinds of electromagnetic problems. Comparisons are made with other methods, concluding that FEM-DBCI is competitive with the well-known FEM-BEM and coordinate transformations for what concerns accuracy and computing time.

Long-Lasting Orientation of Symmetric-Top Molecules Excited by Two-Color Femtosecond Pulses

Impulsive orientation of symmetric-top molecules excited by two-color femtosecond pulses is considered. In addition to the well-known transient orientation appearing immediately after the pulse and then reemerging periodically due to quantum revivals, we report the phenomenon of field-free long-lasting orientation. Long-lasting means that the time averaged orientation remains non-zero until destroyed by other physical effects, e.g., intermolecular collisions. The effect is caused by the combined action of the field-polarizability and field-hyperpolarizability interactions. The dependence of degree of long-lasting orientation on temperature and pulse parameters is considered. The effect can be measured by means of second (or higher-order) harmonic generation, and may be used to control the deflection of molecules traveling through inhomogeneous electrostatic fields.

Methods for calculating thermal processes under conditions of natural convection of gaseous methane under the influence of electrostatic fields

Relying on the review and analysis of scientific and technical literature, as well as the results of experimental studies, we developed new methods for calculating thermal processes occurring in gaseous methane during its natural convection, under the influence of electrostatic fields. In this study we show methods for calculating and determining the coefficients of heat transfer to gaseous methane under the influence of electric wind, as well as methods for calculating and determining the effect of electrostatic fields on the negative process of sedimentation on a heated experimental working plate in the volume of gaseous methane. A general method has been developed for the effective and safe application of electrostatic fields in gaseous methane, which must be carried out in the calculations, design, creation, and operation of new engines, power plants, and techno systems for single and reusable ground, air, aerospace and space-based aircraft.