Corona Discharge Method Research Articles

Purification of surface water by using the corona discharge method

Purpose. The primary objective of this research is to develop a technology for achieving water quality at the level of Maximum Permissible Concentrations (MPC) required by sanitary regulations and norms. Methods. To meet these regulatory requirements, experimental studies were conducted to analyze the chemical and microbiological composition of water, focusing on parameters such as the total microbial count (quantity/ml), coliform bacteria (quantity/ml), coliphages (quantity/100 ml), clostridia (cl/20 ml), and other harmful substances. The research also examined water disinfection processes depending on the autumn and winter seasons of the year. Findings. To assess the device’s effectiveness, the research determined the optimal ozone concentration and contact time in the disinfection chamber. The findings indicate that 0.6 grams per hour (G = 0.6 g/hour) of ozone (O3) per cubic meter of surface water is sufficient for the removal of harmful microbiological substances. Originality. The primary innovation in this research lies in the establishment of parameters for an ozone generator utilizing a novel corona discharge method. The study introduces both theoretical frameworks and practical methodologies for effectively disinfecting surface waters using this innovative technique. Practical implications. This case study offers insights that can be applied and replicated in regions facing similar water quality challenges.

A novel study for supercapacitor applications via corona discharge modified activated carbon derived from Dunaliella salina microalgae

Chemical activation factors including type of chemical agent and amount of agent, as well as carbonization procedures like burning temperature and burning time, have an impact on the surface characteristics of activated carbon. In this study, Dunaliella Salina microalgae was converted to supercapacitor electrode materials for the first time by using multiple parameters such as chemical agent, amount of chemical agent, burning temperature, and burning time, and then new electrode materials were obtained by applying different activation with the help of electrical corona discharge. Dunaliella Salina microalgae were used as activated carbon in accordance with the experimental protocol designed by the Taguchi L9 (3,4) technique. Specific capacitance values of each supercapacitor electrode material were subjected to a linear regression model to determine the effect of each parameter. It has been found that the parameter with the most significant positive effect on the specific capacitance value is the burning temperature. The surface properties of MAD-3, which has the best specific capacitance value of 284.86 F/g, were further improved by being exposed to corona discharge at different frequency values in a two-electrode system. The best specific capacitance value was measured as 335.23 F/g for the MAD-C50 under the condition that the frequency of the application voltage is 50 Hz. In addition, SEM-EDS, and XRD analyses were performed and BET measurements showed that the corona discharge method increased the pore volume and surface area of activated carbon more than 1.6 times.

Effects of gaseous ozone treatment on the quality and microbial community of salmon (Salmo salar) during cold storage

To elucidate the effect of gaseous ozone with different dose and exposing time (A and B: 1 mg/m 3 or 3 mg/m 3 for 5 min; C and D: 1 or 3 mg/m 3 for 10 min, respectively, corona discharge method) on the quality of salmon, the microbial growth, lipid oxidation, color, odor characteristics, microbiota, and the correlations between them were studied. The results showed that the total viable counts of groups C (6.05 log CFU/g) and D (5.71 log CFU/g) were lower than the control (7.08 log CFU/g) on day 10. The ozone treatment also retarded the increase of total volatile basic nitrogen (TVB-N), thiobarbituric acid substances (TBARS), and drip losses as well as the decrease of sensory scores. Though the ozonated treatment led to a slight decrease of a * value, it could deodorize the fishy smell. The results of next-generation sequencing showed that the relative abundance of Photobacterium decreased after treatments, but recovered during storage, and it was the predominant bacteria causing the deterioration of salmon fillets according to the correlation analysis with sensory score, TVB-N, and TBARS values. The results demonstrated that gaseous ozone was a promising method for salmon preservation, and the exposing time had a greater effect on the salmon quality than the ozone concentrations in this study. The ozonation treatment with the dose of 1 or 3 mg/m 3 for 10 min was recommended for salmon fillets. • Photobacterium was the main bacteria causing the quality deterioration of salmon. • Gaseous ozone reduced the relative abundance of Photobacterium after treatment. • The exposing time had a greater effect on the salmon quality than the ozone dose. • The optimal ozonation treatment for salmon was 1 or 3 mg/m 3 for 10 min. • The deodorizing effect of ozone may relate to the ozonolysis of fatty acids.

Structure formation and depolarization relaxation processes in porous piezoactive polyvinylidene fluoride films

Piezoactive porous polyvinylidene fluoride films prepared in the process based on melt extrusion with subsequent isometric annealing, uniaxial extension and thermal fixation have been studied. It was shown that two competing orientation processes -polymorphous transition of non-polar α-phase into polar piezoactive β-phase and formation of porous structure - occur during the uniaxial extension of annealed films. It has been established that orientation degree of extruded films is the key factor determining the efficiency of both processes. Thermally stimulated depolarization method was used to investigate the dipole relaxation in oriented films, and activation energy of these processes was found. The films were polarized using corona discharge and high-voltage contact methods, both, and the dependence of piezoelectric modulus on the polarization conditions has been obtained. The maximum value of piezoelectric modulus d31=30.1 pC/N was achieved by polarization of films in corona discharge method. Keywords: polyvinylidene fluoride, porous films, supramolecular structure, piezoelectric properties, polarization, relaxation processes.

Endowing the sustainable antistatic properties to epoxy-based composites through adding graphene nanoplatelets

In order to explore the possibility of reducing the potential hazards caused by the accumulation of static charges in electronic components, graphene nanoplatelets with remarkable conductive property were added as functional fillers into epoxy matrix to enhance the antistatic property of composites used as the encapsulating materials. Optical microscope and scanning electron microscope were used to observe the dispersion of graphene fillers in the polymer to indicate the completeness of the establishment of the conductive network. The surface of the material was charged by corona discharge method, then the decay characteristics of the static charges was continuously measured. The accumulation and decay of the static charges on the surface of the sample were systematically analyzed by combining with water contact angle, resistivity and relevant permittivity parameters. Results showed that the antistatic ability of material had been constantly enhanced with the increase of graphene content. It was worth noting that when only 0.5 wt% graphene fillers were added, the surface and volume resistivity of composite could reach 5.38 × 1012 Ω/square, 2.37 × 1010 Ω.cm respectively, fully meeting the requirement standard of antistatic encapsulating material for electronic devices. It is forecasted that the prepared composites have considerable prospects in the antistatic encapsulation of electronic devices and aerospace fields.

Corona Discharge Properties Near Metal and Dielectric Surface

This following research of the properties of a coronary discharge has a serious impact on the study of metallurgy. There are a lot of cases of practical use of the corona discharge functions. An example is the creation of electrostatic precipitators for the purification of industrial gases from solid and liquid particles. Using the corona discharge method, for example, smoke is cleaned in the production of sulfuric acid, air in non-ferrous metal foundries and other harmful industries. Shape of the corona discharge made utilizing cone shaped and round and hollow terminals was examined. The most electrical characteristics of discharge of this type are decided. Corona discharges are characterized by weak currents within the extend of one microampere at voltages on the arrange of 10 kilovolts and adequately week gleam discharge. Electric fluctuations within the discharge current circuit within the extend 1 kHz-120 MHz are enlisted. To think about the oscillatory forms, there were used electric and attractive tests, signals from which were sent to the Tektronix TDS 2024B oscilloscope working within the frequency analyzer mode. The electrical tests were spoken to by metal poles 1-10 cm in length and 4-5 mm in diameter. As magnetic tests, there were used coils (diameter 2-4 mm, number of turns 70-140, wire thickness 0.1 mm) set in protective dielectric walled in areas. These tests were located at a separate of 0.5-1.0 m from the release. Possible waves in plasma are suggested to explain these oscillations.

Filtration performance and charge degradation during particle loading and reusability of charged PTFE needle felt filters

Electret filter materials have attracted wide attention because of their low pressure drop and high filtration efficiency. Few studies have measured the filtration performance and the charging status of the charged filters during soot particle loading. In this study, the polytetrafluoroethylene (PTFE) needle felt filters were charged by a corona discharge method. The filtration efficiency and surface potential were investigated during the soot particle loading process. The effects of NaCl particles, soot particles and A2 dust on surface potential and filtration efficiency were investigated. The reusability of charged filters and the effect of temperature on surface potential were studied. The results indicated that the initial filtration efficiency of charged PTFE needle felt filters (PNFFs) was greatly improved compared with that of uncharged PNFFs. The attenuation rate of the surface potential at 100 °C was faster than that at room temperature. The surface potential decreased with the start of particle deposition on the filters, correspondingly, the filtration efficiency of the charged PNFFs decreased. The efficiency of charged PNFFs loaded by soot particle decreased first and then increased, with the transition point corresponding to 20 Pa of pressure drop growth. With the same increment of pressure drop, soot particles with higher conductivity caused more efficiency degradation than NaCl particles. The reusability of the charged filters was affected by the effectiveness of dust cake removal and the particle conductivity.

Fabrication of piezoelectric vibration energy harvester using coatable PolyVinylidene DiFluoride and its characterisation

A cantilever-type vibration energy harvester (VEH) made of PolyVinylidene DiFluoride (PVDF) was fabricated and characterised. PVDF is one of polymer piezoelectric material, which is more flexible than ceramic-based piezoelectric materials such as lead zirconate titanate. Since PVDF dissolves in organic solvent, it is coatable on substrate or parts, making it compatible with micro electro mechanical systems process. The fabrication process of VEH is as follows: a PVDF film (thickness: 30 µm) was coated on a phosphor bronze rectangular plate (length: 35 mm, width: 15 mm, thickness: 0.1 mm) by bar-coating method, followed by polarisation by corona discharge method. Aluminium top electrode (length: 30 mm, width: 10 mm, thickness: 0.3 μm) was deposited on the PVDF film by DC sputtering. One end of the plate was clamped by a fixture to form a cantilever, the length of which is 25 mm. Finally, a proof mass (m = 0.2 g) was attached to the free end of cantilever. Output power P at resonant frequency (= 55 Hz) was measured as a function of load resistance R, in which acceleration was set to 17 m/s2. Maximum output of 4.3 µW was achieved at R = 2.1 MΩ, which is not inferior to those of reported VEHs using ceramic piezoelectric materials.

Influence of Low-Temperature Plasma Treatment on The Liquid Filtration Efficiency of Melt-Blown PP Nonwovens in The Conditions of Simulated Use of Respiratory Protective Equipment

Abstract Filtering nonwovens produced with melt-blown technology are one of the most basic materials used in the construction of respiratory protective equipment (RPE) against harmful aerosols, including bio- and nanoaerosols. The improvement of their filtering properties can be achieved by the development of quasi-permanent electric charge on the fibres. Usually corona discharge method is utilized for this purpose. In the presented study, it was assumed that the low-temperature plasma treatment could be applied as an alternative method for the manufacturing of conventional electret nonwovens for the RPE construction. Low temperature plasma treatment of polypropylene nonwovens was carried out with various process gases (argon, nitrogen, oxygen or air) in a wide range of process parameters (gas flow velocity, time of treatment and power supplied to the reactor electrodes). After the modification, nonwovens were evaluated in terms of filtration efficiency of paraffin oil mist. The stability of the modification results was tested after 12 months of storage and after conditioning at elevated temperature and relative humidity conditions. Moreover, scanning electron microscopy and ATR-IR spectroscopy were used to assess changes in surface topography and chemical composition of the fibres. The modification of melt-blown nonwovens with nitrogen, oxygen and air plasma did not result in a satisfactory improvement of the filtration efficiency. In case of argon plasma treatment, up to 82% increase of filtration efficiency of paraffin oil mist was observed in relation to untreated samples. This effect was stable after 12 months of storage in normal conditions and after thermal conditioning in (70 ± 3)°C for 24 h. The use of low-temperature plasma treatment was proven to be a promising improvement direction of filtering properties of nonwovens used for the protection of respiratory tract against harmful aerosols.

Characterization of Electret Based on Inorganic-organic Nanocomposite Using Fluoropolymer and Silica Nanoparticles

An A novel electret based on inorganic-organic nano composite using fluoropolymer and silica nanoparticles was developed in this study. CYTOP® is used to fabricate the nanocomposite electret, which is one of fluoropolymer. Three kinds of silica nanoparticles dispersed in methyl ethyl ketone were employed. Each type of nanoparticles was mixed in the CYTOP or stuck between three layers of CYTOP. Then, negative charge was implanted by corona discharge method. The initial surface potential of the nanocomposite electret was higher than that of a control electret made of pure CYTOP. Additionally, time stability of those was also better than that of control electret. However, above mentioned properties of the mix-typed electret was worse than that of stuck-typed electret, because of discharging through aggregates composed of the nanoparticles.

Combination of Air Ionization and Engineering Physics Methods for Optimization Agroindustry

Air/water ionization technology (AIT) in the greenhouse farms is one of the offering methods of increasing healthy crops and much more productions as usual methods in agricultural industry. AIT is a hi-tech equipment for improving farms productions beside of growing plants process. This technology has more important in improvement of plants living conditions in greenhouses. According to the performed research, utilizing the agricultural modern technologies, have an efficient effect on the quantity and quality of greenhouses and farms products. For this reason, negative ion injections into the greenhouse farms could be a part of research policies in developing and least developing countries for effective exploitation and correction of agricultural conditions, as it was the part of basic researches policies in last 40 years in developed countries. In this paper, we try to introduce hi-tech air ionization equipment based on corona discharge method and expression of its importance using in developing and least developing countries.

Applications to Engineering Physics for Reducing Air Pollution

Taking advantage of modern technology of the macro ionization of air in the air conditioning systems in order to promote the industrial air conditioning systems can be an appropriate way to resolve industrial centers and hospital's pollution, and also resolve monitoring of air in the urban tunnels. Breathing space around us is a mixture of particles and neutral and charged molecules, so by looking back at industrial achievements of tools and instruments of the air conditioners, electrical discharge method is practical and appropriate. In addition to refining of air pollutants, there is also the possibility of removing germs. Macro Air Ionization Technology (MAIT) in the industrial, hospital and urban tunnels is one of the offering methods of increasing healthy air as usual methods in environment. MAIT is a hi-tech equipment for improving air. One of these technologies is Negative Air Ionization Technology (NAIT). In the NAIT equipment air molecules after ionization change Negative Ion Concentrations in the room, tunnels and sheds. The negative ion molecules especially oxygen, will provide a healthy environment for plants growth process. Using NAIT, anions have the ability to conquest the microbes and microorganism. According to the performed research, utilizing the air ventilation modern technologies, have an efficient effect on the quantity and quality of important place as hospitals. For this reason, negative ion injections by MAIT into the air could be a part of research policies in developing and least developing countries for effective exploitation and correction of the Health and Safety Executive (HSE) conditions, as it was the part of basic research policies in last 40 years in developed countries. In this paper, we try to introduce hi-tech MAIT equipment based on corona discharge method.

Development of Acoustic Emission Sensor Based on the 0-3 PZT/P(VDF-TFE) Piezoelectric Composite

In this paper, we produced the 0-3 PZT/P(VDF-TFE) piezoelectric composite film with 80μm thickness using PZT piezoelectric ceramics and fluorine resin P(VDF-TFE) by weight 85/15 ingredients through the hot rolling machine and corona-discharge method. A sensor with 4cm×1.3cm area is designed and produced by using this film. We have carried out the breaking of a pencil lead pressed against an aluminum plate acoustic emission testing. The result shown that the sensor is with fast response and high sensitivity advantage, the sensor can be used as acoustic emission sensor. Meanwhile the sensor is very easy to use due to it is a soft film sensor.

Studies on Electromechanical foam material (EFOAM) as a potential Sensor and Actuator

A novel electromechanical foam (EFOAM) material capable of acting as an electromechanical transducer with integrated functions as a sensor - actuator is investigated by manufacturing some samples of the foam and performing some tests, based on the piezo-electric effect in electro-active polymers. The resulting charge, when different known weights are applied to the sample were observed and recorded with a charge amplifier while the actuator sensitivity was also estimated using the micro-scanning laser Doppler vibrometer. EFOAM is manufactured from expancel microspheres and heated by placing the microspheres in glass slides heated up to temperatures of 135 0 C for expansion. Different samples were manufactured and charged using the corona discharge method operating under an electric field of between 11kV/cm to 15kV/cm. EFOAM displayed an electro-mechanical sensitivity of 1nm/V when characterized, and is observed that the piezoelectric nature of EFOAM exists as a characteristic of each cell within the material sample. This novel material offers much promise in the area of production of miniature electromechanical devices which maybe well applied in electroacoustic applications.

A New Approach of Electric Field Adoption for Germination Improvement

Enhancement of tomato seed germination is one of the most important factors for developing a supply chain of increased demand. Tomato is one of the important cash crops in the world. To fulfill increased requirement, electric field adoption is the best alternative. The study was undertaken at MPKV, Rahuri for improvement in tomato seed germination. Three different approaches were utilized as electrostatic field, microwave and corona discharge method to treat tomato seeds. The comparative analysis revealed that adoption of electrostatic field application was simple as well as powerful method with significantly positive results. In electrostatic field, the optimal dosage was 2 kV/mm for 20 second interval to improve germination, root shoot length and seed vigor.

Influence of a SiN Drift-Barrier on the Charge Decay in Parylene-C Electret Layers

This paper reports on the attempt to improve the charge carrier life time in Parylene-C electret layers by implementing a drift barrier layer close to the surface. The barrier layer is intended to avoid the rapid discharge by ionic drift through the electret layer. For this purpose, we fabricated test chips comprising silicon nitride drift barriers with thicknesses of 50nm, 100nm and 200 nm sandwiched between a 7.1-μm-thick Parylene-C base layer and capping Parylene-C electret layers of three thicknesses, charged using the corona discharge method. Experimentally, it turns out that there is no pronounced influence on the charging process due to the drift barrier. Surface potential measurements were repeated over a period of 20days. Up to t = 10days a weak improvement of the remaining surface potential can be interpreted into the data. However, thereafter the surface potentials decrease rapidly. Surface potential line scans over the samples show that the decreased width of the charge carrier distribution, likely due to an enhanced horizontal drift or diffusion, is the reason. This effect is not observed on charged Parylene-C layers without drift barrier.

DEVELOPMENT OF OZONE WATER DISINFECTION

The aim is to develop a portable ozone generator which can produce the ozone gas in the discharge tube by corona discharge method. By this method oxygen is converted to ozone by the application of high voltage through the line output transformer. Some electronics components are being used to generate the modulated output of high and low frequency to avoid the high voltage shock. Titration experiment has been carried out to detect the ozone gas as well as the amount of ozone output from the discharge tube. Ozone has numerous beneficial effects for mankind. Out of them the impure or surface water where the coli form group of bacteria may be present has to be disinfected by the application of ozone through the multiple tube fermentation technique or the presumptive phase.

Effects of Temperature and Flow Rates of Ozone Generator on the DBD by Varying Various Electrical Parameters

This study rationale a high voltage power supply which varies of (O-5) kV with the variable frequency of 50 Hz-5 kHz. The power supply is used in the dielectric barrier discharge tube for the ionization process to yield concentration of ozone.This setup points the development of small and high efficient ozone generators using corona discharge method. Ozone generation was carried out by varying parameters including voltage, frequency, flow rate and temperature to yield high concentration of ozone. The feeding gas composition greatly affected the ozone generation rate, which was increased in order of ambient air to dry air. With increase in temperature, ozone concentration is increased while ozone generation rate is enhanced. In the experiments, a maximum ozone concentration of approximately 83 ppm is obtained, the peak value of applied voltage of about 5kV and gap of electrode is 4.3mm respectively. Dry air is used as feeding gas with residence time of 10.58 sec.

디젤엔진의 후처리장치로서 PCD 플라즈마 시스템에 관한 연구

The selective catalytic reduction(SCR) system used to reduce NOx in diesel engines requires an NO/<TEX>$NO_2$</TEX> ratio of about 1 in exhaust emissions to realize the fast SCR mode at temperatures lower than <TEX>$300^{\circ}C$</TEX>. This study investigated the characteristics of a plasma system as a pre-active apparatus for the fast SCR reaction mode of an SCR system. Plasma was generated by the pulse corona discharge(PCD) method with a four-channel wire-cylinder reactor. This study showed that plasma was easily generated in the exhaust gas by the PCD system, and the peak voltage of the normal state condition for plasma generation was generally 12 kV. The PCD system easily converted NO into <TEX>$NO_2$</TEX> at lower temperatures and the NO/<TEX>$NO_2$</TEX> conversion ratio increased with the discharge current for plasma generation. But the PCD system could not convert NO into <TEX>$NO_2$</TEX> at higher engine speeds and higher engine loads due to the lack of oxygen in exhaust gas. The PCD system also activated the diesel oxidation catalysts(DOC) system to reduce CO emissions.

Kinetics of inactivation of Pseudomonas aeruginosa in aqueous solutions by ozone aeration

The effect of ozonation on the disinfection of Gram-negative strain, Pseudomonas aeruginosa was investigated as a function of time. Ozone was generated in situ using corona discharge method, with ozone concentrations ranging from (0.29–9.84) × 10− 5 moles L− 1. The microbial inactivation kinetics followed pseudo–first-order kinetics under excess concentration conditions of ozone. With over all second-order constant, k = (4.02 ± 0.20) × 104 M− 1 min− 1, the reaction rate had first-order dependence both on the microbial count and ozone. The influence of temperature and pH on the ozone initiated disinfection of the microbe was also investigated. Molecular ozone is found more effective in disinfection than hydroxyl radicals. Probable mechanism for antimicrobial power of ozone in water systems is discussed. The ozone aeration decreased the biochemical oxygen demand (BOD) value of natural and microbe spiked waters significantly.