Article
Physics, Applied
Xing Zhang, Yulin Guo, Shahriar Mirpour, Yanru Li, Anbang Sun, Sander Nijdam
Summary: Positive streamers in air are significantly affected by corona discharges, resulting in shorter and weaker discharges or even prevention of initiation. On the other hand, in nitrogen, the impact of corona discharges on streamers is minimal. The differences in streamer behavior between air and nitrogen are attributed to the plasma shielding effect caused by corona discharges.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2021)
Article
Chemistry, Analytical
Eric J. Davis, David Walker, Molly Gibney, Brian H. Clowers
Summary: The research investigated the transition between ESI and CDI modes with respect to applied bias, revealing that CDI reaches stable state faster in positive mode compared to ESI, while stability in negative mode varies greatly in both modes. When examining the resultant ions, it was found that the impact of increased bias on an ESI needle was species-dependent, with labile species showing significant fragmentation at higher biases.
Article
Physics, Multidisciplinary
E. C. Stancu, A. Quade, F. Hempel
Summary: In this study, the bio-decontamination of PU and PVC was performed using corona discharge with a scanning procedure. Increasing the number of scans enhanced the effectiveness of plasma treatment against E. coli and S. aureus. Changes in polymer surface properties after plasma treatment were also examined.
ROMANIAN REPORTS IN PHYSICS
(2022)
Article
Engineering, Chemical
M. Khalifehei, F. J. Higuera
Summary: In this study, an Eulerian one-dimensional model is proposed to analyze the discharge process of a dilute spray of electrically charged droplets between two parallel electrodes with opposite polarity. The effects of droplet flux, ion current, and applied voltage on the neutralization process are discussed. The results show the existence of a minimum voltage, depending on other parameters, below which the problem is unsolvable. The conditions to prevent droplet fly-back are also discussed.
JOURNAL OF AEROSOL SCIENCE
(2023)
Article
Physics, Applied
Yusuke Nakagawa, Keisuke Nagao, Fumiyoshi Tochikubo
Summary: The behavior of droplets, Taylor cone tip, and discharge current characteristics in electrospraying with negative corona discharge were investigated and analyzed. Results indicated that the curvature radius of the cone tip dominates the discharges from the Taylor cone. Droplet emission was synchronized with the leading current in the Trichel pulses, and the droplet emission mechanism is presumed to differ when there are discharges compared to when there are none.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2021)
Article
Engineering, Chemical
Widya Sinta Mustika, Dian Ahmad Hapidin, Casmika Saputra, Muhammad Miftahul Munir
Summary: The study utilized dual needle corona discharge (NCD) as a bipolar ion source to neutralize electrospray particles, achieving stable concentration and consistent size distribution. The bipolar ions generated by the dual NCD effectively neutralized and reduced the charge state of larger ES-PSL particles.
ADVANCED POWDER TECHNOLOGY
(2021)
Article
Engineering, Chemical
Fellype do Nascimento, Augusto Stancampiano, Kristina Trebulova, Sebastien Dozias, Jan Hrudka, Frantisek Krcma, Jean-Michel Pouvesle, Konstantin Georgiev Kostov, Eric Robert
Summary: This paper provides detailed information about a newly developed plasma system for conductive target non-thermal plasma indirect treatment. The system uses high voltage microsecond duration pulses to ignite a discharge in a glass funnel vessel flushed with argon and equipped with a needle electrode. The air dielectric barrier discharge (DBD) can subsequently be generated in the funnel-DBD setup. The study characterizes the plasma electrode DBD using time-resolved ICCD imaging and voltage and current probes.
PLASMA CHEMISTRY AND PLASMA PROCESSING
(2023)
Article
Physics, Applied
Jianwei Gu, Shengxin Huang, Yufei Fu, Weijiang Chen, Dengfeng Cheng, Weidong Shi, Zhong Fu, Zhehao Pei, Xing Fan, Tianyu He
Summary: The study focused on the morphology of leader coronas during discharge processes, revealing variations in the streamer region morphology at different discharge phases. Discrepancies were found between actual measurements and photographic reports of leader corona cone apex angles, attributed to the temporal resolution of the optical imaging apparatus. Experimental results also indicated consistent statistical distribution characteristics of leader coronas under stable conditions, suggesting universal applicability for simulation research. Further analysis showed that the distortion of the electric field caused by space charge explained the changes in the streamer area during discharge processes.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2021)
Article
Chemistry, Inorganic & Nuclear
Virginia G. Rodriguez, Heather J. Culbertson, Ginger E. Sigmon, Peter C. Burns
Summary: The ionization processes of uranyl triperoxide monomer (UT) and uranyl peroxide cage cluster (U28) were investigated using electrospray ionization mass spectrometry (ESI-MS). Various experiments provided insights into the mechanisms of ionization, including tandem mass spectrometry with collision-induced dissociation, the use of different solvents and nebulizer gases. The observed anions in the UT and U28 systems were attributed to gas-phase combinations, reduction-oxidation reactions, and ionization of surrounding analytes. The electronic structures of anions UOx- (x = 6-8) were studied using density functional theory (DFT).
INORGANIC CHEMISTRY
(2023)
Article
Multidisciplinary Sciences
Takamasa Okumura, Pankaj Attri, Kunihiro Kamataki, Naoto Yamashita, Yuichi Tsukada, Naho Itagaki, Masaharu Shiratani, Yushi Ishibashi, Kazuyuki Kuchitsu, Kazunori Koga
Summary: This study provides experimental evidence that atmospheric-pressure air dielectric barrier discharge plasma irradiation introduces nitrate ion (NO3-) as reactive oxygen and nitrogen species (RONS) in lettuce seeds, promoting their germination. The ion introduced by plasma irradiation was detected and identified as NO3- using various analytical techniques. Scanning electron microscopy revealed no surface changes on the seeds after plasma irradiation. Plasma irradiation is an effective method for introducing NO3- into seeds without causing damage.
SCIENTIFIC REPORTS
(2022)
Article
Nanoscience & Nanotechnology
Xiaodong Xue, Xiaoqiong Wen, Yuantian Yang, Liru Wang, Xue Wang
Summary: This study observed the temporal evolution of shock fronts launched by microsecond pulsed positive streamer discharge in water and investigated the initial pressure of the shock front. A method was discovered to accurately determine the radius of the shock front and obtain its temporal evolution. The research found that the applied voltage and water conductivity did not affect the initial pressure of the shock front within the studied range.
Article
Polymer Science
Xiaobo Meng, Liming Wang, Hongwei Mei, Bin Cao, Xingming Bian
Summary: This paper presents a study on the influence of curved profiles of shed on the propagation of flashover along polymer insulators. The research shows that reasonable curved profiles can improve the flashover voltage and reduce system outages. The relationship between streamer propagation and flashover propagation is discussed, as well as the impact of material properties on streamer propagation.
Article
Meteorology & Atmospheric Sciences
S. A. Peeters, S. Mirpour, C. Kohn, S. Nijdam
Summary: This study investigates the conditions for the onset of corona discharges from ellipsoidal hydrometeors, and finds that corona onset can occur in thundercloud conditions for certain aspect ratios of realistic volume hydrometeors.
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
(2022)
Article
Chemistry, Analytical
Guoping Li, Yueguang Lv, Meng Chen, Xiwen Ye, Zengyuan Niu, Hua Bai, Haimin Lei, Qiang Ma
Summary: A green analytical strategy utilizing SUPRAS-based extraction and UHPSFC-tandem mass spectrometry with an imidazolium-based dicationic ionic liquid (DIL) was developed for the analysis of 10 perfluorinated compounds (PFCs), showing improved ionization efficiency and sensitivity in the positive ionization mode. The method was successfully applied to real textiles and food packaging materials, demonstrating great potential for analyzing anionic compounds.
ANALYTICAL CHEMISTRY
(2021)
Article
Physics, Fluids & Plasmas
Dennis Bouwman, Hani Francisco, Ute Ebert
Summary: We have developed an axial model for single steadily propagating positive streamers in air, which estimates difficult-to-measure quantities using observable parameters. Our model approximates important parameters such as ionization density, electric field, and charge layer width based on given velocity, radius, length, and applied background field. By analytically approximating electron dynamics and electric fields in different regions of the streamer head and matching the solutions on the boundaries, we accurately model the streamer as a whole and determine unknown quantities using conservation laws. Our model shows good agreement with numerical simulations for various streamer lengths and background electric fields, providing a way to estimate experimentally inaccessible quantities from easily measurable ones and paving the way for efficient axial multi-streamer models.
PLASMA SOURCES SCIENCE & TECHNOLOGY
(2023)
Article
Engineering, Chemical
Katarina Kucerova, Zdenko Machala, Karol Hensel
PLASMA CHEMISTRY AND PLASMA PROCESSING
(2020)
Article
Physics, Applied
Gervais B. Ndiffo Yemeli, Renata Svubova, Dominik Kostolani, Stanislav Kyzek, Zdenko Machala
Summary: The study found that plasma-activated water (PAW) generated by nonthermal air plasmas can potentially improve plant growth and influence physiological parameters for maize and barley seedlings, without causing harmful DNA damage.
PLASMA PROCESSES AND POLYMERS
(2021)
Article
Environmental Sciences
Mostafa Elsayed Hassan, Mario Janda, Zdenko Machala
Summary: The study investigates the transport of gaseous H2O2 and O3 into water through plasma-liquid interactions. It is found that electrosprayed microdroplets have a larger total surface area than bulk water, but have a shorter lifetime. Only microdroplets with diameters below 40μm could achieve saturation by O3 during their lifetime, and longer-lived bottom microdroplets also contribute significantly to the solvation of H2O2 and O3 in water electrospray.
Review
Biochemistry & Molecular Biology
Peter Polcic, Zdenko Machala
Summary: Cold plasmas can affect cell physiology and viability, leading to various technologies for sterilization, food processing, seed germination, and cell therapy. However, the mechanisms of plasma-cell interactions are still poorly understood, necessitating the use of simple eukaryotic models to study these effects.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2021)
Article
Physics, Applied
Mario Janda, Mostafa E. Hassan, Viktor Martisovits, Karol Hensel, Michal Kwiatkowski, Piotr Terebun, Joanna Pawlat, Zdenko Machala
Summary: The study presents a diagnostic technique for online monitoring of electrostatic spray microdroplets, allowing for simultaneous electrical and optical diagnostics. Based on laser light attenuation, the technique enables estimations of microdroplet speed and size, as well as monitoring of dripping frequency and fragmentation of microdroplets and water filaments.
JOURNAL OF APPLIED PHYSICS
(2021)
Article
Biochemistry & Molecular Biology
Dominika Sersenova, Zdenko Machala, Vanda Repiska, Helena Gbelcova
Summary: Plasma medicine is a new field focusing on biomedical and clinical applications of cold gas plasmas, including their anticancer effects. Effects of plasma-activated liquids (PAL) on cancer cells showed selectivity compared to normal fibroblasts, depending on correctly chosen activation time and PAL concentration. Plasma-generated hydrogen peroxide may play a role in the selectivity effect of PAL on cancer cells.
Article
Chemistry, Multidisciplinary
Mario Janda, Karol Hensel, Peter Toth, Mostafa E. Hassan, Zdenko Machala
Summary: The study found that transient spark discharge simultaneously generates NO and NO2 in the gas phase, while forming microdroplets through water electrospray, facilitating the production of high concentrations of H2O2(aq)-, NO2(aq)- and NO3(aq)- in plasma-activated water. Additionally, in the combined system of water electrospray and TS discharge, gaseous HNO2 plays a key role in the formation of NO2(aq)- in plasma-activated water.
APPLIED SCIENCES-BASEL
(2021)
Article
Food Science & Technology
Barbora Tarabova, Francesco Tampieri, Elisabetta Maran, Ester Marotta, Andrea Ostrihonova, Marco Krewing, Zdenko Machala
Summary: The study investigated the safety and efficacy of air non-thermal plasma treatment on freshly squeezed apple juice. The treatment successfully inactivated microorganisms, extended the juice shelf-life, and had minimal impact on key physico-chemical parameters of the juice. This method shows promising application potential in food technology.
Article
Plant Sciences
Dominik Kostolani, Gervais B. Ndiffo Yemeli, Renata Svubova, Stanislav Kyzek, Zdenko Machala
Summary: This study demonstrates the indirect effects of non-thermal ambient air plasmas on seed germination and plant growth, showing stimulation of amylase activity in pea seedlings but oxidative stress in barley.
Article
Engineering, Chemical
Michal Pastorek, Maria Suchonova, Barbora Konecna, Slavomir Pasztor, Jakub Petrus, Nadja Ivaskova, Peter Celec, Roman Gardlik, Zdenko Machala, L'ubomira Tothova
Summary: Urinary tract infections (UTI) caused by resistant uropathogenic bacteria are a serious health concern. This study aimed to evaluate the potential of cold plasma activated liquid (PAL) as a treatment for UTI using an animal model. However, the in vivo experiments showed that PAL had no significant effect on bacterial load in the mouse model of UTI, possibly due to the attenuating effect of urine and its toxicity on immune cells.
PLASMA CHEMISTRY AND PLASMA PROCESSING
(2022)
Article
Engineering, Chemical
Gervais B. Ndiffo Yemeli, Mario Janda, Zdenko Machala
Summary: This study investigates the potential of using non-thermal plasma for seed priming to improve the yield of pea seeds. Direct plasma treatment significantly improves the yield and has a long-term effect. Indirect treatment improves certain growth parameters of pea plants. Scanning electron microscopy analysis reveals morphology changes on the surface of the pea seeds induced by the treatments.
PLASMA CHEMISTRY AND PLASMA PROCESSING
(2022)
Article
Physics, Multidisciplinary
Robin Mentheour, Zdenko Machala
Summary: In this study, the antibacterial effect of reactive oxygen and nitrogen species (RONS) in plasma-activated water (PAW) on the inactivation of E. coli bacteria was investigated. It was found that the presence of both nitrites (NO2-) and hydrogen peroxide (H2O2) in PAW exhibited an enhanced antibacterial effect, which was further reinforced by the mild pulsed electric field (PEF) treatment. The results suggest a synergy between the chemical and physical plasma agents, opening new perspectives for applications in both plasma and PEF research areas.
FRONTIERS IN PHYSICS
(2022)
Article
Chemistry, Physical
Michal Kwiatkowski, Piotr Terebun, Katarina Kucerova, Barbora Tarabova, Zuzana Kovalova, Aleksandra Lavrikova, Zdenko Machala, Karol Hensel, Joanna Pawlat
Summary: The purpose of this study is to determine the operating parameters of an atmospheric pressure, radio-frequency DBD plasma jet reactor for precise treatment of biological materials. The results showed that a narrow shape of plasma stream can generate significant amounts of H2O2, allowing for mild decontamination of bacteria at a relatively low power of the system, which is safe for the treatment of biological materials.
Article
Biochemistry & Molecular Biology
Anna Strizova, Paulina Smatralova, Petra Chovancikova, Zdenko Machala, Peter Polcic
Summary: Exposure of living cells to non-thermal plasma affects cell physiology and often results in cell death. This study investigated the involvement of cellular components or pathways in plasma-induced cell killing, revealing that mitochondria play a crucial role in both the damage and signaling, leading to cell protection.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2023)
Article
Physics, Applied
Barbora Gromova, Barbora Konecna, Maria Suchonova, Slavomir Pasztor, Peter Celec, Lubomira Tothova, Michal Lichvar, Jaroslav Budis, Jan Radvanszky, Diana Rusnakova, Tomas Szemes, Zdenko Machala, Roman Gardlik
Summary: This study analyzed the impact of plasma-activated water (PAW) on oxidative status and gut microbiota diversity in healthy mice and mice with inflammatory bowel disease (IBD). The results showed that PAW increased oxidative stress markers in the colon tissue, especially in IBD mice. Interestingly, PAW increased microbial diversity in a healthy gut but decreased it in an inflamed gut. The findings suggest that PAW may not have therapeutic potential in treating IBD.
PLASMA PROCESSES AND POLYMERS
(2023)
