Plasma Pub Date : 2023-12-21 DOI: 10.3390/plasma7010002

Joshua Ginzburg, Mobish Shaji, Alexander Rabinovich, Dmitri Vainchtein, Christopher Sales, Alexander Fridman

{"title":"Effects of Non-Thermal Plasma on the Transition from Nano-Crystalline to Amorphous Structure in Water and Subsequent Effects on Viscosity","authors":"Joshua Ginzburg, Mobish Shaji, Alexander Rabinovich, Dmitri Vainchtein, Christopher Sales, Alexander Fridman","doi":"10.3390/plasma7010002","DOIUrl":"https://doi.org/10.3390/plasma7010002","url":null,"abstract":"Recent studies have demonstrated that the physical properties of water treated with non-thermal plasma, or plasma-activated water (PAW), significantly differ from those of distilled water. For example, contrary to expectation, the viscosity of PAW becomes lower than that of distilled water at certain temperatures. This study developed a model to explain these differences by combining the two-state model of ordinary water, which describes water as a combination of nano-crystalline clusters and amorphous, free-floating molecules, using the Debye–Huckel theory for a fluid containing ions. A model for the viscosity of PAW was then developed from the general model. It explains how PAW has a lower viscosity than distilled water as the temperature decreases and why this effect is stronger than the colligative effect for ideal solutions. Finally, the viscosity model is compared to the experimental measurements of PAW treated with gliding arc plasma, showing that the data match the predicted values quite well. The model of PAW developed here can be used to understand other physical properties beyond viscosity, such as the surface tension, contact angle, electric conductivity, heat capacity, isothermal compressibility, and density, potentially facilitating new applications of PAW.","PeriodicalId":509984,"journal":{"name":"Plasma","volume":"20 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139167528","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A Semi-Empirical Model of Cathodic Arc Spot Motion under the Influence of External Magnetic Fields 外磁场影响下阴极弧点运动的半经验模型

Plasma Pub Date : 2023-12-19 DOI: 10.3390/plasma7010001

A. Mahrle, Otmar Zimmer, Steffen Schenk, M. Borkmann, Christoph Leyens

引用次数: 0

Pulsed Dielectric Barrier Discharges for Gas-Phase Composition Control: A Simulation Model 用于气相成分控制的脉冲介质势垒放电：模拟模型

Plasma Pub Date : 2023-12-12 DOI: 10.3390/plasma6040050

R. Barni, Prince Alex, Claudia Riccardi

引用次数: 0

Experimental Progress in the Development of a Metal Foil Pump for DEMO 为 DEMO 开发金属箔泵的实验进展

Plasma Pub Date : 2023-11-28 DOI: 10.3390/plasma6040049

Y. Kathage, Alejandro Vazquez Cortes, S. Merli, Christian Day, T. Giegerich, Stefan Hanke, J. Igitkhanov, Andreas Schulz, Matthias Walker

{"title":"Experimental Progress in the Development of a Metal Foil Pump for DEMO","authors":"Y. Kathage, Alejandro Vazquez Cortes, S. Merli, Christian Day, T. Giegerich, Stefan Hanke, J. Igitkhanov, Andreas Schulz, Matthias Walker","doi":"10.3390/plasma6040049","DOIUrl":"https://doi.org/10.3390/plasma6040049","url":null,"abstract":"Experimental findings to contribute to the preliminary design of a metal foil pump for fuel separation in the Direct Internal Recycling loop of the DEMO fusion device are presented. In parametric studies on a small-scale superpermeation experiment with a microwave plasma source and two different metal foil materials, niobium Nb and vanadium V, a substantial increase in permeation with plasma power and with a decrease in pressure was observed. To ease operation in the typical fusion environment, in-situ heating procedures were developed to recover from impurity contamination. The temperature independence of plasma-driven permeation from 600 to 900 °C metal foil temperature was demonstrated. No proof of an isotopic effect for plasma-driven permeation of protium and deuterium could be found. The highest repeatable permeation flux achieved was 6.7 Pa∙m3/(m2∙s) or ~5.5 × 10−3 mol H/(m2∙s). The found compression ratios do safely allow the operation of the metal foil pump using ejector pumps as backing stages for the permeate. In a dedicated experimental setup, the operation of the plasma source in a strong magnetic field was tested. Parametric studies of pressure, power input, magnetic flux density, field gradient and field angle are presented.","PeriodicalId":509984,"journal":{"name":"Plasma","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139221702","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Generation of Plasma-Activated Fluids for Successful Disinfection of Pseudomonas aeruginosa in Liquid Environments and Determination of Microbial Damage 为成功消毒液体环境中的铜绿假单胞菌生成等离子激活液并确定微生物损伤情况

Plasma Pub Date : 2023-11-21 DOI: 10.3390/plasma6040048

Mareike Hummert, Paul Leenders, Alexander Mellmann, Karsten Becker, Thorsten Kuczius

{"title":"Generation of Plasma-Activated Fluids for Successful Disinfection of Pseudomonas aeruginosa in Liquid Environments and Determination of Microbial Damage","authors":"Mareike Hummert, Paul Leenders, Alexander Mellmann, Karsten Becker, Thorsten Kuczius","doi":"10.3390/plasma6040048","DOIUrl":"https://doi.org/10.3390/plasma6040048","url":null,"abstract":"The application of the non-thermal atmospheric pressure plasma technology is a promising tool for microbial inactivation. During the activation process, many reactive substances and radicals arise associated with physicochemical changes in the fluid and massive pH drop. In this study, we analyzed and optimized plasma activation settings and conditions of water and liquids to obtain inactivation of the waterborne microorganism Pseudomonas aeruginosa in a liquid environment. The minimal electrical output was 60 Watt with 20 min activation time followed by 30 min contact time with 108 cells/mL. Using higher electrical power (>90 W) with a Lab Unit generating plasma-activated water, a shorter activation time (<10 min) was sufficient for bacterial inactivation. The organic and inorganic composition of the activated liquid with different mineral salt concentrations is of utmost importance for the yield of reactive species during the plasma activation process and consequently for the antimicrobial effect. Plasma-activated fluids with high organic and inorganic contents demonstrated lower inactivation efficiencies than low loaded fluids; yet antimicrobial efficacy could be achieved by increasing the electrical power and activation time. For sufficient inactivation of bacterial suspensions, at least half a volume unit of plasma-activated water had to be added after appropriately optimized activation. Further dilutions reduced the antimicrobial effect. PAW lost activity after being left standing for a prolonged time after activation, so for maximizing the antimicrobial effect a direct use after activation is recommendable. Bacterial inactivation was shown by the absence of colony forming units on culture media and, at the molecular level, damage to the membrane and inactivation of enzymes were observed. Plasma-activated fluids demonstrated a high potential in applications as microbiological disinfectant in liquids.","PeriodicalId":509984,"journal":{"name":"Plasma","volume":"132 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139250896","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Influence of Voltage, Pulselength and Presence of a Reverse Polarized Pulse on an Argon–Gold Plasma during a High-Power Impulse Magnetron Sputtering Process 高功率脉冲磁控溅射过程中电压、脉冲长度和反向极化脉冲对氩金等离子体的影响

Plasma Pub Date : 2023-11-20 DOI: 10.3390/plasma6040047

Jürgen Guljakow, Walter Lang

{"title":"Influence of Voltage, Pulselength and Presence of a Reverse Polarized Pulse on an Argon–Gold Plasma during a High-Power Impulse Magnetron Sputtering Process","authors":"Jürgen Guljakow, Walter Lang","doi":"10.3390/plasma6040047","DOIUrl":"https://doi.org/10.3390/plasma6040047","url":null,"abstract":"This work aims to provide information about the deposition of gold via bipolar high-power impulse magnetron sputtering (HIPIMS) in order to identify suitable process parameters. The influences of voltage, pulse length and the kick-pulse on an argon–gold plasma during a bipolar high-power impulse magnetron sputtering deposition process were analysed via optical emission spectroscopy (OES) and oscilloscope. The voltage was varied between 700 V and 1000 V, the pulse length was varied between 20 µs and 100 µs and the process was observed once with kick-pulse and once without. The influence of the voltage on the plasma was more pronounced than the influence of the pulse width. While the intensity of several Au I lines increased up to 13-fold with increasing voltages, only a less-than linear increase in Au I brightness with time could be identified for changes in pulse length. The intensity of excited argon is only minimally affected by changes in voltages, but follows the evolution of the discharge current, with increasing pulse lengths. Contrary to the excited argon, the intensity emitted by ionized argon grows nearly linearly with voltage and pulse length. The reverse polarised pulse mainly affects the excited argon atoms in the plasma, while the influence on the ionized argon is less pronounced, as can be seen in the the spectra. Unlike the excited argon atoms, the excited gold atoms appear to be completely unaffected by the kick-pulse. No ionization of gold was observed. During the pulse, a strong rarefaction of plasma takes place. Very short pulses of less than 50 µs and high voltages of about 1000 V are to be preferred for the deposition of gold layers. This paper offers a comprehensive overview of the gold spectrum during a HIPIMS process and makes use of optical emission spectroscopy as a simple measuring approach for evaluation of the reverse polarized pulse during a bipolar process. Future uses of the process may include the metallization of polymers.","PeriodicalId":509984,"journal":{"name":"Plasma","volume":"41 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139255512","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

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