Modeling the electrical energy discharged by lightning flashes using capacitors for application with lightning datasets

This study employed a parallel plate capacitor model by which the electrostatic energy of lightning flashes could be estimated by considering only their physical dimensions and breakdown electric fields in two simulated storms. The capacitor model has previously been used to approximate total stormelectrostatic energy but is modified here to use the geometry of individual lightning flashes to mimic the local charge configuration where flashes were initiated. The energy discharged may then be diagnosed without context of a storm’s entire charge structure. The capacitor model was evaluated using simulated flashes from two storms modeled by the National Severe Storms Laboratory’s Collaborative Model for Multi-scale Atmospheric Simulation (COMMAS). Initial capacitor model estimates followed the temporal evolution of the flash discharge energy of COMMAS for each storm but demonstrated the need to account for an adjustment factor to represent the fraction of energy a flash dissipates, as this model assumes the entire pre-flash energy is discharged by a flash. Individual values of were obtained simply by using the ratio of the COMMAS flash to capacitor energy. Median values were selected to represent the flash populations for each storm, and were in range of = 0.019−0.021. Application of aligned the magnitudes of the capacitor model discharge energy estimates to those of COMMAS and to those estimated in previous studies. Therefore, by considering a within range of , application of the capacitor model for observed lightning datasets is suggested.

DIELECTRIC MEASUREMENTS ON PURE AND KDP ADDED DISODIUM HYDROGEN PHOSPHATE (DSHP) SINGLE CRYSTALS

Electrical conductivity is an elegant experimental tool to probe the structural defects and internal purity of crystalline solids. In the present study we have grown pure and KDP added DSHP single crystals by the slow evaporation method from aqueous solutions at room temperature. Good quality transparent crystals have been obtained. Melting point and density measurements were done. Electrical conductivity measurements were carried out with two frequencies, 100 Hz and 1 kHz at various temperatures ranging from 2 to 30oC by using the parallel plate capacitor method. The present study indicate that the dielectric constant and AC and DC conductivities increase with increase of temperature.

A Comparative Analysis Of MEMS Parallel Plate Actuators

The purpose of this study is to compare the deformation of the moving top plate of five distinct parallel plate capacitor designs under applied voltage as well as compare the pull-in voltage of each design. The parallel plate designs are created using AutoCAD 2008 software and the simulations are performed using CoventorWare 2010. The control design is first validated with known results and then compared to the remaining four designs. Finally, pull-in voltages of all five designs is determined and compared to determine the advantages and disadvantages of each design.

A Comparative Analysis Of MEMS Parallel Plate Actuators

The purpose of this study is to compare the deformation of the moving top plate of five distinct parallel plate capacitor designs under applied voltage as well as compare the pull-in voltage of each design. The parallel plate designs are created using AutoCAD 2008 software and the simulations are performed using CoventorWare 2010. The control design is first validated with known results and then compared to the remaining four designs. Finally, pull-in voltages of all five designs is determined and compared to determine the advantages and disadvantages of each design.

Research on the measurement of intracranial hemorrhage in rabbits by a parallel-plate capacitor

Intracranial hemorrhage (ICH) carrying extremely high morbidity and mortality can only be detected by CT, MRI and other large equipment, which do not meet the requirements for bedside continuous monitoring and pre-hospital first aid. Since the biological tissues have different dielectric properties except the pure resistances, and the permittivity of blood is far larger than that of other brain tissues, here a new method was used to detect events of change at the blood/tissue volume ratio by measuring of the head permittivity. In this paper, we use a self-made parallel plate capacitor to detect the intracranial hemorrhage in rabbits by contactless capacitance measurement. The sensitivity of the parallel-plate capacitor was also evaluated by the physical solution measurement. The results of physical experiments show that the capacitor can distinguish between three solutions with different permittivity, and the capacitance increased with the increase of one solution between two plates. At the next step in the animal experiment, the capacitance changes caused by 2 ml blood injection into the rabbit brain were measured. The results of animal experiments show that the capacitance was almost unchanged before and after the blood injection, but increased with the increase of the blood injection volume. The increase of capacitance caused by blood injection was much larger than that before and after blood injection (P < 0.01). The experiments show that this method is feasible for the detection of intracranial hemorrhage in a non-invasive and contactless manner.

Maxwellian stresses and electromagnetic forces that arise from them in vacuum and media.

Faraday and Maxwell conceived the electrostatic and magnetostatic fields as lines of force filling the space around charges and currents, with or without matter. They also established that there are tensions along the lines of force, and compressions around these lines. These ideas are formalized with a stress tensor, whose divergence is a force density. We follow these ideas to show the origin of the electric forces that arise in the case of a dielectric slab partially introduced into a parallel-plate capacitor, and the origin of the magnetic forces that arise in the case of a magnetizable bar partially introduced into a solenoid. We find that these forces have their origin in the abrupt change in permittivity and permeability which produce a difference of pressures at interfaces. This approach permits us to analyze the similarities and differences between both cases. Advanced undergraduate and graduate students can get interesting insights into the electromagnetic forces exerted by electrostatic and magnetostatic fields in vacuum and matter. Faraday y Maxwell concibieron los campos electrostáticos y magnetostáticos como líneas de fuerza llenando el espacio alrededor de cargas y corriente, con o sin materia. Ellos establecieron que hay tensiones a lo largo de las líneas de fuerza, y compresiones alrededor de estas líneas. Estas ideas se formalizan con el tensor de esfuerzos, cuya divergencia es una densidad de fuerza. Nosotros seguimos estas ideas para mostrar el origen de las fuerzas eléctricas que surgen cuando una barra de dieléctrico se introduce parcialmente en un condensador de placas paralelas, y el origen de las fuerzas magnéticas que surgen en el caso de una barra magnetizable parcialmente introducida en un solenoide. Encontramos que estas fuerzas tienen su origen en el cambio abrupto en la permitividad y permeabilidad que produce una diferencia de presiones en la interface. Este enfoque nos permite analizar las similitudes y diferencias entre ambos casos. Los estudiantes no graduados y graduados pueden adquirir una percepción interesante sobre las fuerzas electromagnéticas ejercidas por campos electrostáticos y magnetostáticos en el vacío y en la materia