Electrochemical cleaning of soils with different concentrations of oil pollution using a single source of electrical voltage

The most essential scientifific and practical task in the area of ecological safety of pipelines operation is the development and improvement of methods of purifification and restoration of oil-contaminated soils. One of the most effificient and cost effective methods is electrochemical purifification, that does not require the use of expensive chemical reagents and soil excavation. However, the consideration of non-uniform contamination of various soil sections is required. The article examines the features of the organization and technological infrastructure for electrochemical purifification of non-uniformly contaminated soils when using a single electrical energy source, a method for calculating the design parameters of the corresponding installation is proposed. Effificient purifification of non-uniformly contaminated soil when using a specifified voltage is possible through the use of different-sized electrodes. For each soil type, the amount of transmitted electric charge required for soil purifification is determined by the concentration of the contaminant. Allocation of cathodes and anodes as parallel batteries and their connection using individual buses is an effective and energy-effificient solution, since an almost-uniform electric fifield is created in an inter-electrode space, thus allowing the reduction of the interelectrode resistance of the medium.

The influence of external electrostatic field on the combustion of hexamine

In scientific work investigates the impact of electric fields on combustion of hexamine. The experimental setup has been developed to study the interaction of an electric field with a low-temperature flame. The optimal spatial configuration of the electrodes for extinguishing the flame was established; the dynamics of airflows caused by the ion wind was studied; the threshold value of the electric field leading to flame extinguishing was determined. An expression is proposed based on the equation of motion that connects the speed of motion of partially ionized gas particles, the viscosity and degree of ionization of the gas, and the intensity of the external electric field. It is shown that the strength of the external electric field, leading to extinguishing of hexamine combustion, increases with decreasing inter-electrode space. The values of corresponding electric field strength lied in range from 80 to 135 kV/m at interelectrode distances of 0.4 and 0.1 m, respectively. The results of the study can be used for effective fire extinguishing in compact devices running on dry fuel.

Electroencephalographic Correlates of Temporal Bayesian Belief Updating and Surprise

The brain predicts the timing of forthcoming events to optimize responses to them. Temporal predictions have been formalized in terms of the hazard function, which integrates prior beliefs on the likely timing of stimulus occurrence with information conveyed by the passage of time. However, how the human brain updates prior temporal beliefs is still elusive. Here we investigated electroencephalographic (EEG) signatures associated with Bayes-optimal updating of temporal beliefs. Given that updating usually occurs in response to surprising events, we sought to disentangle EEG correlates of updating from those associated with surprise. Twenty-six participants performed a temporal foreperiod task, which comprised a subset of surprising events not eliciting updating. EEG data were analyzed through a regression-based massive approach in the electrode and source space. Distinct late positive, centro-parietally distributed, event-related potentials (ERPs) were associated with surprise and belief updating in the electrode space. While surprise modulated the commonly observed P3b, updating was associated with a later and more sustained P3b-like waveform deflection. Results from source analyses revealed that surprise encoding comprises neural activity in the cingulo-opercular network (CON). These data provide evidence that temporal predictions are computed in a Bayesian manner, and that this is reflected in P3 modulations, akin to other cognitive domains. Overall, our study revealed that analyzing P3 modulations provides an important window into the Bayesian brain. Data and scripts are shared on OSF: https://osf.io/ckqa5/?view_only=f711e6f878784d4ab94f4b14b31eef46

Оптимизация анодной мембраны с прострельной мишенью в системе источников мягкого рентгеновского излучения для проведения процессов рентгеновской нанолитографии

In this paper, we propose a method for optimizing the design and composition of the anode membrane with a transmission-type target as part of a system of soft X-ray sources based on field-emission triodes for performing tasks in the field of X-ray nanolithography. It allows to prevent the degradation of the operating characteristics of the system when significant electrostatic deformation of the anode occurs under the influence of a control electric field in the inter-electrode space of the triodes. For this purpose, the inclusion of an additional control electrode in the system design is considered, which makes it possible to compensate for the deformation of the anode membrane to an acceptable level and thereby stabilize the operation of X-ray sources. A numerical model of the electrostatic deflection of the anode assembly in a modified design is developed, based on which the optimal composition and geometric parameters of the anode membrane with a compensating electrode are determined. In particular, the optimal distance between the anode membrane in the initial (undeformed) state and the compensating electrode was found (equal to 5 μm), at which a minimum voltage difference (about 1.15 kV) should be applied to these electrodes to prevent critical deflection of the membrane (0.72 μm with a membrane radius of 750 µm). It is also shown that, due to their extremely high hardness (>80 GPa), diamond-like films are the most promising material for the anode electrode. The results obtained can also be useful for the development of miniature X-ray generation devices for various applications.

EVALUATION OF THE INFLUENCE OF ELECTRIC WIND ON THE EFFICIENCY OF DISPERSED PARTICLES REMOVAL FROM THE FLUE GAS STREAM IN ELECTROSTATIC PRECIPITATORS

The question of influence of the electric wind on efficiency of dispersed particles removal from a flue gas stream in electrostatic filters has not been studied well enough. Estimates are given of the role and influence of electric wind on the particle trapping processes in industrial electrostatic precipitators, as well as the results of experiments and calculations using aplied computational fluid dynamics packages. The results of mathematical modeling of the speed of dust particles of different diameters under the action of electric wind in the inter-electrode space of a corona discharge are presented; and the effects of turbulence of a gas flow on the particles capturing, the influence of the near-wall jet and the probabilistic nature of the removal of solid particles from the dusted exhaust gas flow are evaluated. Ref. 18, Fig. 5.

Principles of the express method for controlling interelectrode space condition during wire electrochemical processing

In the practical implementation of the sequential wire electrical discharge machining – pulsed electrochemical machining (WEDM – PECM) technology and in order to perform high quality electrochemical processing, there is a need for the real-time operational control of electrical parameters of inter-electrode space and corresponding adaptive correction of amplitude-frequency power supply parameters (AFPSP). In the context presented by the authors, a mathematical apparatus and an algorithm of operational galvanostatic mode monitoring of anode dissolution using wire electrode-tool are proposed. This will allow adaptive adjustment of AFPSP to ensure controlled passage of electrochemical reactions and significantly increase process stability, dissolved surface layer thickness uniformity along entire electrode tool movement trajectory and resulting surface quality.

Optimization of a Novel Micro-Hotplate for Gas Sensor

A novel design of micro-hotplate is proposed for micro-structural gas sensor. The simulation results of ANSYS reveal that higher temperature and more uniform temperature distribution was achieved in the micro-hotplate when the thickness of SiO2, thickness of Si substrate, electrode width and electrode space were designed to be 100, 200, 20 and 230 μm, respectively. The new micro-hotplate is benefit for the improvement of sensor sensitivity.