Electrical Discharges In Gases Research Articles

Разработка СВЧ-установки для термообработки отходов убоя животных

Every day, the Russian Federation processes 126.3 tons of animal slaughter waste into animal feed. With an installation capacity of 35 kg/h, the required quantity is 7000 units. As a rule, the devices are energy-intensive. The problem is to reduce the operating costs of heat treatment of raw materials while maintaining the feed quality. The article introduces a new installation powered by an electrically driven resonator with rationalized operating modes. The research featured mucous by-products that require thermal treatment to neutralize the smell and disinfect the raw material. The authors investigated the dynamics of heating and used the data obtained to develop a digital installation model and test the electrodynamics in the resonator. After that, they rationalized the operating modes, i.e., corona discharge, electric field, screen efficiency, generator power, installation performance, and energy costs. The complex action of electromagnetic radiation provided a continuous combined heat treatment, disinfection, and odor neutralization with reduced operating costs. The electrical resonator was coaxially located in the shielding and contained a coronating electrode, electric bactericidal UV gas discharge lamps, knives, screws, and emitters from air-cooled magnetrons. The annular volume between the resonator and the coat excited the traveling wave by electromagnetic radiation through the perforation. Its average perimeter was a multiple of half the wavelength. The heat treatment with disinfection and fat rendering required an intrinsic quality factor of 8000, a generator power of 4.4 kW, a productivity of 35–40 kg/h, and energy costs of 0.25–0.28 kWh/kg. When the electric field was 5 kV/cm and the corona discharge was 9.79 kV/cm, the corona of bactericidal lamps provided the required ozone concentration and the bacterial contamination fell down to an acceptable level. The new installation with an electrical resonator reduced operating costs for heat treatment of animal slaughter waste and maintained the high-quality of the resulting feed products.

Microwave device for heat treatment of meat by-products and waste

BACKGROUND: In the conditions of farms, there is a problem of neutralizing unpleasant odors during heat treatment of secondary meat raw materials to preserve the consumer properties of protein feed at low operating costs. AIM: Development of the device for heat treatment with disinfection and neutralization of the unpleasant odor of crushed secondary meat raw materials with the integral effect of an ultra−high frequency electromagnetic field, a bactericidal flow of UV rays and ozone in a continuous mode with electromagnetic safety ensured. METHODS: The raw materials are the stomach chambers of ruminants. The basic idea, principle of operation and design of the device are based on the propagation of microwave oscillations in a resonator with a spiral decelerating system. The microwave device contains a non-ferromagnetic cylinder with a perforated lower base, a coaxially arranged non-ferromagnetic spiral cylinder and an electrically driven fluoroplastic auger with a solid screw surface. The average perimeter of the annular volume, between the cylinder and the spiral cylinder forming the coaxial resonator, and its height are multiples of half-wavelength. Corona brushes are mounted to the annular base of the cylinder, under which electric gas discharge lamps powered by 1 kHz frequency generators are radially located, and a ceramic annular spherical surface is located under the lamps. Magnetrons are mounted along the perimeter of the outer cylinder with a shift of 120 degrees. The crackling is removed using a pneumatic conveyor. RESULTS: The feature of the coaxial resonator is that the inner core is formed as a spiral decelerating system. Therefore, the intrinsic Q-factor of the resonator is high, about 115000, therefore, the expected thermal efficiency is 0.7–0.75. The factor of dielectric losses of raw materials with a decrease in humidity from 76% to 30% is reduced by five times. Thus, while keeping the electric stress at the level of 1.2–2 kV/cm, the electromagnetic field power dissipated in a unit of the volume of the crackling decreases by five times, from 34 500 to 6800 W/cm3. CONCLUSIONS: A new design solution with a spiral coaxial resonator, the use of a ceramic reflector, and a number of physical factors made it possible to develop the design of the operation chamber for the heat treatment of ruminant slaughter waste with the neutralization of unpleasant odors with a capacity of 30–35 kg/h and specific energy costs of 0.16–0.19 kWh/kg.

Structure and properties of carbon-containing nanostructured coatings on metal surfaces obtained by electric discharge in gas and electric explosion of electrical conductors

Structure and properties of carbon-containing nanostructured coatings on metal surfaces obtained by electric discharge in gas and electric explosion of electrical conductors

New materials for the electromechanical and acoustoelectric transducers

The technology for creation of the polymer-microsized piezoelectric composite substrate is developed by employing the electric gas discharge plasma method. It is determined experimentally that as a result of the nano-structurization of the volume of the polymer-piezoceramic composite close to the surface it is Young and piezo-modulus as well as the mechanical quality and electromechanical coupling coefficients and the dielectric constant has been increased, whereas, tangent losses are decreased depending on the type of the nanoparticle and its volume rate.

The Influence of Neutron and Gamma Radiation Fields on Gas-Filled Surge Arresters

Abstract The study examines the effect of neutron and gamma radiation on commercial gas surge arresters. The research is of experimental-theoretical nature. The experimental part of the research was performed un-der well-controlled laboratory conditions. The combined measurement uncertainty was about 5%. The experimental system is specially designed for the observed problem and has certain original solutions. The test procedure was fully automated and had software support in the experiment management and also for data collection and statistical processing. The obtained results show that neutron and gamma ra-diation improves the functional characteristics of gas surge arresters with a memory effect. The obtained results are explained in accordance with the theory of interaction of neutron and gamma fields with ma-terial and with the theory of electric discharge in gases. The results presented in this study are important for the design of surge protection in systems that can be found in the field of neutron and gamma radia-tion because they can achieve a positive synergistic effect of protection in hybrid schemes with other components for surge protection whose characteristics spoil this radiation.

Study of Breakdown Voltage Stability of Gas-Filled Surge Arresters in the Presence of Gamma Radiation

The results presented in this article relate to the study of the impact of gamma radiation on the breakdown voltage of gas-filled surge arrester manufactured by CITEL, Littelfuse and EPCOS at an operating voltage of 230 V. Radium was considered as a source of gamma radiation in this research. The stability of breakdown voltage as well as the reliability of gas-filled surge arresters of different manufacturers were investigated using different statistical methods. This gas component operation was based on processes that lead to electrical breakdown and discharge in gas. The breakdown voltage has a stochastic nature, and it is a subject of certain distribution. One thousand voltage measurements of breakdown voltage were carried out for each value of the voltage increase rate, from 1 V/s up to 10 V/s, with and without the presence of additional gamma radiation. The detailed statistical analysis of the obtained experimental data was performed for both cases for all three GFSA types. Moreover, the cumulative distribution functions of breakdown voltage were presented with the applied Weibull distribution fit. The coefficient of correlation as well as Pearson χ2 test showed the strength of the relationship between the experimental distribution functions and the Weibull distribution fits. The values of the Weibull distribution coefficients for all voltage increase rates and for all components were also analyzed with and without gamma radiation.

Revisiting the numerical stability/accuracy conditions of explicit PIC/MCC simulations of low-temperature gas discharges

Particle-in-cell (PIC) with Monte Carlo collisions is a fully kinetic, particle based numerical simulation method with increasing popularity in the field of low temperature gas discharge physics. Already in its simplest form (electrostatic, one-dimensional geometry, and explicit time integration), it can properly describe a wide variety of complex, non-local, non-linear phenomena in electrical gas discharges at the microscopic level with high accuracy. However, being a numerical model working with discretized temporal and (partially) spatial coordinates, its stable and accurate operation largely depends on the choice of several model parameters. Starting from four selected base cases of capacitively coupled, radio frequency driven argon discharges, representing low and intermediate pressure and voltage situations, we discuss the effect of the variation of a set of simulation parameters on the plasma density distribution and the electron energy probability function. The simulation parameters include the temporal and spatial resolution, the PIC superparticle weight factor, as well as the electron reflection and the ion-induced electron emission coefficients, characterizing plasma–surface interactions.

Applications of Plasma Produced with Electrical Discharges in Gases for Agriculture and Biomedicine

The use of thermal and non-thermal atmospheric pressure plasma to solve problems related to agriculture and biomedicine is the focus of this paper. Plasma in thermal equilibrium is used where heat is required. In agriculture, it is used to treat soil and land contaminated by the products of biomass, plastics, post-hospital and pharmaceutical waste combustion, and also by ecological phenomena that have recently been observed, such as droughts, floods and storms, leading to environmental pollution. In biomedical applications, thermal plasma is used in so-called indirect living tissue treatment. The sources of thermal plasma are arcs, plasma torches and microwave plasma reactors. In turn, atmospheric pressure cold (non-thermal) plasma is applied in agriculture and biomedicine where heat adversely affects technological processes. The thermodynamic imbalance of cold plasma makes it suitable for organic syntheses due its low power requirements and the possibility of conducting chemical reactions in gas at relatively low and close to ambient temperatures. It is also suitable in the treatment of living tissues and sterilisation of medical instruments made of materials that are non-resistant to high temperatures. Non-thermal and non-equilibrium discharges at atmospheric pressure that include dielectric barrier discharges (DBDs) and atmospheric pressure plasma jets (APPJs), as well as gliding arc (GAD), can be the source of cold plasma. This paper presents an overview of agriculture and soil protection problems and biomedical and health protection problems that can be solved with the aid of plasma produced with electrical discharges. In particular, agricultural processes related to water, sewage purification with ozone and with advanced oxidation processes, as well as those related to contaminated soil treatment and pest control, are presented. Among the biomedical applications of cold plasma, its antibacterial activity, wound healing, cancer treatment and dental problems are briefly discussed.

Application of the Monte Carlo Method for the Determination of Physical Parameters of an Electrical Discharge

The aim of this paper is to use of the Monte Carlo Method to try to reproduce an electrical discharge in the oxygen gas; by following the random histories of free electrons and using the sampling laws, we can determine some electrical discharge parameters. Additionally we use the simulation results to verify the electrical breakdown criteria under an homogenous field and for small distances; and the obtained results are compared with those of the literature.

Precise optical registration of fine-structured electrical sparks and related challenges.

Fine-structured sparks naturally formed in electrical gas discharges are challenging objects of optical research. The veracity of the spark structure image obtained by laser probing techniques is still a subject for discussion due to possible distortions introduced by the employed optical setup. We thoroughly analyze this issue by simulating the spark image formation and evaluating the effect of the setup response function on the spark pattern quality. The latter turns out to dramatically suffer from the defocusing effect, whereas the spark fine structure is reliably resolved only by optics having a spatial resolution close to several micrometers.

Carbon Microstructures Synthesis in Low Temperature Plasma Generated by Microdischarges

The aim of this paper is to investigate the process of growth of different carbon deposits in low-current electrical microdischarges in argon with an admixture of cyclohexane as the carbon feedstock. The method of synthesis of carbon structures is based on the decomposition of hydrocarbons in low-temperature plasma generated by an electrical discharge in gas at atmospheric pressure. The following various types of microdischarges generated at this pressure were tested for both polarities of supply voltage with regard to their applications to different carbon deposit synthesis: Townsend discharge, pre-breakdown streamers, breakdown streamers and glow discharge. In these investigations the discharge was generated between a stainless-steel needle and a plate made of a nickel alloy, by electrode distances varying between 1 and 15 mm. The effect of distance between the electrodes, discharge current and hydrocarbon concentration on the obtained carbon structures was investigated. Carbon nanowalls and carbon microfibers were obtained in these discharges.

An overview of Impact of Geopathic Stress on Environment and Human Health

Earth’ core is dynamic and always fluctuating by the natural variations in its rotation, creating a massive energy field, known as electromagnetic field (EMF). We are continuously exposed to a wide spectrum of electromagnetic radiation from both natural and artificial sources which have adverse effects on the subtle balance in nature's energy fields. Natural geopathic stressors include geological faults, geomagnetic anomalies, ley lines crossing, radon gas and underground water courses. The affected geographical locations are known as geopathic stress zones as these locations exert negative effects upon health. Geopathic stress can affect all living beings including humans, animals and plants. It is primarily associated with sick building syndrome, potentially lead to physical and mental illnesses. It may also cause pavement distress, as well as frequent machinery broke down. Energy from the subsurface of the earth at specific locations or in a built environment can be detected by using ancient techniques like dowsing, and modern devices such as Spinning Electric Vector Analyzer (SEVA) and gas discharge visualization (GDV) camera, as well as tests like Vegetative Resonance Test (VRT) and Light Interference Technique (LIT). It is important that one's bed or workstation is located on a geopathic stress free zone. There is much that can be done to ameliorate or remove geopathic stress, such as ‘Feng Shui’, Earth acupuncture, and various other modern Western methods. This paper aims to discuss the potential impact of geopathic stress on the living environment and human health.

Wilhelm Conrad Röntgen: The scientist and his discovery.

Röntgen's discovery of a new type of radiation is the epochal event in a series of highlights of physics emerging within only a few decades of the late 19th century. As these discoveries are directly or indirectly rooting in the study of the phenomenon of electric discharge in gases a brief look at the physics scenario in the immediate pre-X-ray era is presented in the first section. Rather than just the fortune with the bold it is Röntgen's character as a diligent, self-critical and ingenious scientist which made his discovery possible. This will be illustrated in the sections on Röntgen's personal life and some specific details of his experiments leading to the discovery of X-rays. Finally, a short overview is given on the potential and the large variety of applications of X-rays.

Modeling of Streamer Ignition and Propagation in the System of Two Approaching Hydrometeors

AbstractFirst‐principles plasma fluid modeling is used for investigation of electrical gas discharges ignited by a configuration of two approaching conducting hydrometeors with typical radii on the order of several millimeters under thunderstorm conditions (i.e., at an elevated location in the Earth's atmosphere corresponding to half of air density at ground level and at applied electric field approximately half of that required for avalanche multiplication of electrons in air). It is demonstrated that ultraviolet photons produced by the electrical discharges developing due to the electric field enhancement in the gap between two hydrometeors and resultant photoionization in the discharge volume lead to much less stringent conditions for conversion of these discharges to a filamentary streamer form than in the case not accounting for the effects of photoionization. It is also demonstrated that this photoionization feedback is critical for understanding and correct description of the subsequent streamer discharges developing on the outer periphery of two hydrometeors whose potential is equalized due to the electrical connection established by the initial streamer discharge between them. The initial streamer ignition between the hydrometeors can be preceded by the corona development, which can have detrimental effect on the ignition. However, it is demonstrated that for hydrometeors approaching with a speed of 10 m/s the effect of this onset corona is small.

Oxidative degradation of cyclophosphamide using thermal plasma activation and UV/H2O2 treatment in tap water

There is a growing concern about pharmaceuticals entering the aquatic environment. Many of these compounds cannot be removed completely in sewage treatment plants. To remove these unwanted medicines from water, oxidative degradation techniques may complement the current purification steps. In this paper we studied the effect of advanced oxidation on the cytostatic drug cyclophosphamide (CP) by comparing thermal plasma activation with UV/H2O2 treatment. Plasma activated water (PAW) contains highly reactive oxygen and nitrogen species (RONS) as a result of electric gas discharges in air over water. CP solutions in tap water were oxidized over a period of 120 min and subsequently analyzed by LC-MS/MS to measure the compound degradation. Plasma activation was applied at 50, 100, or 150 W electric power input and UV/H2O2 treatment was carried out by the addition of H2O2 and placing an UV-C source above the test solution for immediate irradiation. The oxidative degradation of CP in PAW resulted in a complete degradation within 80 min at 150 W. CP was also completely degraded within 60 min applying UV/H2O2 oxidation. Both treatment techniques do induce different structural changes, demonstrating that CP is completely degraded in tap water.

Tracking Propagation Mechanism on the Surface of Polyvinyl-Chloride-Sheathed Flat Cord based on Electric Field Analysis and Gas Discharge Physics

전기 화재의 주요 원인 중 하나인 트래킹은 전기적 방전에 의한 물리적 현상으로 인식된다. 따라서 트래킹은 전계 해석, 전자생성에 의한 도전성 경로, 기체방전이론을 기반으로 설명되어야 한다. 하지만, 이러한 사항을 반영한 연구 논문은 드물다. 본 논문은 트래킹 진전에서 그들의 영향을 포함한 트래킹 진전 메커니즘을 제안하였다. 그 메커니즘의 제안을 위해, 트래킹 실험, 탄화진전 모델에 대한 전계해석, 연면방전 이론을 적용한 트래킹 진전과정에 대한 설명이 수행되었다. 트래킹 모의실험으로부터, 코로나 방전에서 트래킹 파괴까지 트래킹 진전의 각 단계에서 전류파형이 측정되었다. 전계해석은 탄화의 발생과 진전과정동안 건조대 표면의 전계와 전자생성을 위한 고전계 영역을 파악 하기 위해 수행되었다. 본 논문에서 제안된 트래킹 메커니즘은 코로나 방전에 의한 전자사태, 양이온의 축적, 전자사 태의 확장, 2차 전자사태, 스트리머, 도전성 경로에 의한 트래킹 파괴의 6단계로 구성된다. 트래킹 모의실험에서 측정된 펄스성 전류파형은 제안된 트래킹 메커니즘에 의해 설명될 수 있었다. 본 연구 결과는 화재의 원인인 트래킹을 검출하고, 내트래킹성을 높이는 데 필요한 기술 자료가 될 것이다.Tracking, which is one of the main causes of electrical fires, is perceived as a physical phenomenon of electrical discharge. Hence tracking should be explained based on electric field analysis, conduction path by electron generation, and gas discharge physics. However, few papers have considered these details. This paper proposes a tracking mechanism including their effects on tracking progress. In order to prove this mechanism, a tracking experiment, an electric field analysis for the carbonization evolution model, and an explanation of the tracking process by gas discharge physics were conducted. From the tracking experiment, the current waveforms were measured at each stage of the tracking progress from corona discharge to tracking breakdown. The electric field analysis was carried out in order to determine the electric field on the surface of a dry-band and the high electric field region for electron generation during the generation and progress of carbonization. In this paper, the proposed tracking mechanism consisted of six stages including electron avalanche by corona discharge, accumulation of positive ions, expansion of electron avalanche, secondary electron emission avalanche, streamer, and tracking by conductive path. The pulse current waveforms measured in the tracking experiment can be explained by the proposed tracking mechanism. The results of this study will be used as the technical data to detect tracking phenomenon, which is the cause of electric fire, and to improve the proof tracking index.

Применение совмещённых обмоток в одноимённо-полюсных индукторных двигателях

The mechanical and electrophysical properties of polymeric materials cross-linked by the X-ray radiation of electric gas discharge (EGD) are investigated. The influence of the radiation cross-linking technology on the strength and hardness of polymers is presented on the examples of low- and high-density polyethylene (LDPE and HDPE) samples with different thickness made using the technologies of cross-linking by means of X-ray radiation of electric gas barrier discharge (EGBD) [1–10]. The experimental data have been obtained on samples made in the form of rupture blades cut from polyethylene plates in accordance with GOST IEC 60811-2-1. For studying the electrophysical properties and semi-absorption depth of EGD X-ray radiation, samples in the form of LDPE and HDPE disks having different thickness were used. The X-ray radiation penetration depth into the experimental samples was estimated. Comparative investigations of changes in the electrophysical properties, mechanical strength s, hardness h, and gel fraction s g of cable LDPE under the effect of X-ray radiation from EGD and under the effect of electron beam have been carried out. It has been shown that with using the technology of cross-linking by means of X-ray radiation from EGD, the mechanical strength and hardness of LDPE and HDPE can be increased by no less than 30 and 60%.

The Effect of Density and Concentration of Trapping Centers on Charge Carrier Mobility in Polymer Dielectrics

The spectra of the currents of thermostimulated depolarization and the time dependences of the electret potential difference were measured in polymers irradiated with soft X-rays of electric gas discharge. The results of measurements are used to determining the mobility of electrons and holes in polymer cable and capacitor dielectrics having different values of density and concentration of electrically active trapping centers.

Transient aspects of plasma luminescence induced by triboelectrification of polymers

Transient electric gas discharges that occur around sliding interfaces during contact electrification of polymers were studied at millisecond timescales and with micrometre resolution. Deduced vibrational temperatures indicate cold plasma resulting from positive corona discharge. At millisecond timescales, previously unseen rapid discharge events are observed, and modelling suggests that these result from streamer development, triggered by electron emission from the polymer surface. Those which occur over a period of several seconds are shown to be caused by competition between charge generation and the formation of polymer films. The findings explain the interplay between charging and plasma generation and their dependence on wear processes.

Degradation of cyclophosphamide using plasma activated water and UV/H2O2 for the abatement of persistent pharmaceuticals in wastewater

With the increase of unwanted pollutants in the environment, this study focuses on the abatement and release of pharmaceuticals in the wastewater stream by using the new plasma-activated-water (PAW) technology. PAW is a promising technique for the pre-treatment of contaminated waters, electric gas discharges in air over water produce reactive oxygen and nitrogen species with oxidative degradation power.