Journal of Electrostatics最新文献

This paper deals with the electrostatic charging of material webs in production machines. Measurements were made with a special measurement setup inside a gravure printing press and the results were analyzed and interpreted. In order to gather as much information as possible, the electric field strength of a free-spanning web was monitored at different positions inside the machine and under different production conditions. The measurement results confirmed theoretical principles and practical experience, such as the fact that the type of material, printing inks, coatings, machine speed, web tension, printing process and corona pretreatment have a significant effect on the level and polarity of the electrostatic charging. During the series of experiments, peak field strengths of up to 300 kV/m resulting from the charge on the web were measured and changes in the sign were detected within a very short period of time.

Pipeline leakage accidents of dielectric liquid often occurs in chemical industry, while the investigations on flow electrification of leakage pipe are few. In this study, experiments were conducted to measure and analyze the streaming current inside the pipe and the leakage current of the pipe wall in both intact and leak pipes. Two kinds of diesel oil, namely the light heavy diesel oil and heavy diesel oil, were selected as the flowing media. Furthermore, an empirical expression of the space charge density and the streaming current based on the modified velocity equation was proposed. The space charge density distribution obtained from the experimental streaming current was compared with the theoretical values. The results show that the space charge density obtained from experiments by the proposed expression is in good agreement with the theoretical value.

Bromide in treated natural waters is oxidized to toxic bromate with ozone. For the novelty of pulsed corona discharge (PCD) in water treatment, it's potential in bromide transformation needs clarification. Experimental research into bromide-bromate conversion dependent on control parameters, including pulse repetition frequency, pH, Br⁻ concentration, and presence of organics, was undertaken. Bromide transformed to bromate in acidic and circum-neutral media; transformation of bromate to bromide was also observed. Bromide was poorly oxidized in alkaline media. Oxidation of bromide was obstructed with oxalate. Formation of nitrate was noticeably decelerated by bromate.

In the applied electric field, the behavioral characteristic which occurs in particle-particle systems always are used in dielectric insulation, and nanomaterials regulation, among which is the key to correctly compute the electric field. Because the dipole model without fully considering the particle interactions so that has defects in computing in some cases. This study introduced the mutual-coupling dipole offset distance τ used to describe the degree of inter-particle interaction, the analytical expression of the mutual-coupling dipole moment under the two types of the electric field is obtained, respectively. An original model is established, and by comparison with the finite element method, it is found that even when D = 0.1R and ε_pp/ε_f = 25, the proposed model can describe the inter-particle interaction effectively, and its computational precision better than that of the classical model, which can realize the accurate computation of the electric field distribution around the particle-particle rotating system.

Measure for intensity of electrostatic interaction between two disjoint sets of charged conductors is introduced, and it is called relative intensity of interaction (RII). Firstly, we examine properties and we found various forms and upper bounds for RII between charged conductors and neutral conductors. The most important derived expression for RII is in terms of Schur complement of original capacitance matrix and capacitance matrix of system without neutral conductors. RII between two disjoint sets $S_1$ and $S_2$ of arbitrarily charged conductors is bounded above by sum of RII’s between charged set $S_1$ and neutral set $S_2$, and vice versa.