Article
Physics, Fluids & Plasmas
Yuanyuan Jiang, Yanhui Wang, Yamin Hu, Jiao Zhang, Dezhen Wang
Summary: A 2D axial symmetry fluid model was used to study the features of an atmospheric-pressure argon plasma jet propagating into ambient nitrogen, driven by pulsed voltage. Gas velocity was shown to have a significant influence on the dynamic characteristics of the jet, affecting its spatial distribution and length. The increase in gas velocity results in changes in the jet's dynamic behavior, electron density structure, and length propagation.
PLASMA SCIENCE & TECHNOLOGY
(2022)
Article
Physics, Fluids & Plasmas
Reza Janalizadeh, Victor P. Pasko
Summary: This study revisits the photoionization problem of nitrogen and oxygen molecules in atmospheric pressure helium plasma and provides experimental results. It is shown that photoionization occurs due to radiative decay of the electronic A state of helium molecules, and a kinetic model for the production of the fast component of ultraviolet emissions is proposed.
PLASMA SOURCES SCIENCE & TECHNOLOGY
(2023)
Article
Energy & Fuels
Kai Xie, He Liu, Yunjing Cui, Gan Cui, Xingqi Qiu, Jianxin Wang
Summary: The safety of a horizontal spray combustion flame and the design of a heating device for a low-pressure area of a plateau have been widely examined. The shape equation and length of a flame's trajectory are the two most important indexes. The study demonstrates that maintaining rated volume air flow results in coinciding flame trajectories under different atmospheric pressures.
Article
Engineering, Mechanical
Lei Zhang, Chen Ding, Yanjun Han, Zhirui Zhang, Cheng Fan
Summary: This study investigates a novel pulsating cavitation air jet polishing (PCAJP) process to improve the material removal rate and surface quality of Ti-6Al-4V alloy. By optimizing the main process parameters, the roughness of the specimens is successfully reduced to a lower level.
TRIBOLOGY INTERNATIONAL
(2022)
Article
Physics, Applied
Tam Nguyen, Peng Lin, Demetre J. Economou, Vincent M. Donnelly
Summary: Optical emission spectroscopy was used to measure the radial distribution of ambient air species diffusing into a helium atmospheric pressure plasma jet. Both experimental and simulation results showed that N-2 shielding gas effectively reduced air diffusion.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2021)
Article
Physics, Applied
Delin Kong, Ping Zhu, Feng He, Ruoyu Han, Bingyan Yang, Manyu Wang, Jiting Ouyang
Summary: The experimental and numerical results demonstrated that the introduction of N-2 and O-2 admixture significantly affects the length and propagation velocity of a helium atmospheric-pressure plasma jet. The changes in electron density outside the grounded electrode are related to the modifications in jet length.
JOURNAL OF APPLIED PHYSICS
(2021)
Article
Materials Science, Multidisciplinary
Yan Zhang, Chenghu Ke, Yanchen Xie, Yunzhe Zhang
Summary: The propagation properties of Laguerre-Gaussian (LG) beam in a turbulent atmosphere are experimentally investigated. The results indicate that as the propagation distance increases, the beam gradually spreads, the intensity distribution of LG beam becomes divergent and weakened, and the position of the singularity becomes unstable. Comparing with a Gaussian beam, the LG beam shows better propagation stability.
RESULTS IN PHYSICS
(2022)
Article
Astronomy & Astrophysics
Ciara A. Maguire, Eoin P. Carley, Pietro Zucca, Nicole Vilmer, Peter T. Gallagher
Summary: The study presents a solar eruptive event occurred on October 16, 2015, focusing on observations of a jet in extreme ultraviolet, a streamer in white light, and a metric type II radio burst. The research reveals that the radio burst sources were located above the jet at a distance of approximately 0.5 solar radii, with a propagation speed of around 1000 km/s, significantly faster than the jet speed of about 200 km/s.
ASTROPHYSICAL JOURNAL
(2021)
Article
Multidisciplinary Sciences
Torsten Neubert, Olivier Chanrion, Matthias Heumesser, Krystallia Dimitriadou, Lasse Husbjerg, Ib Lundgaard Rasmussen, Nikolai Ostgaard, Victor Reglero
Summary: Blue jets are lightning-like atmospheric electric discharges that propagate from thunderclouds to the stratosphere, initiated by electric breakdown within the cloud. Their leader elements are short and localized, and they are associated with intense spectral flashes, suggesting a connection to lightning discharges.
Article
Physics, Applied
Li Wu, Xianyu Zhang, Tao Liu, Wencong Zhang, Junwu Tao, Fei Cheng
Summary: This Letter presents an atmospheric pressure low power microwave-induced air plasma source operating at 2.45 GHz. The device can self-ignite air and generate plasma with only 50 W microwave input power, without any additional trigger. Its sustaining power is as low as 10 W, and the gas temperature of plasma tail flame is about 32 degrees C measured by a fiber optic thermometer. Spectroscopic measurements revealed the presence of strong OH(A(2)S(+)? X-2?) bands at 306-310 nm and oxygen atomic lines O-I (3p5P? 3s5S) at 777.1 nm and O-I (3p3P?3s3S) at 844.6 nm. Furthermore, NO- ?(A(2)S(+)?X-2?(r)) from 200 to 300 nm was also detected in the air plasma jet. This portable plasma apparatus shows potential for air plasma applications in the biomedical fields.
APPLIED PHYSICS LETTERS
(2023)
Article
Physics, Applied
Tuyen Ngoc Tran, Cha-Hwan Oh, Wonwook Lee
Summary: The study experimented on atmospheric pressure plasma and found that adding a target can enhance continuum radiation and increase electron density.
PLASMA PROCESSES AND POLYMERS
(2021)
Article
Thermodynamics
Khurshid Ahmad, Vaibhav Kumar Arghode
Summary: The combustion characteristics of a novel PVRF combustor using Jet-A1 fuel were investigated, showing low emissions and stable operation over a wide range of equivalence ratios. The combustion was primarily stabilized by a dominant peripheral vortex of hot burned gases inside the combustor.
THERMAL SCIENCE AND ENGINEERING PROGRESS
(2021)
Article
Spectroscopy
Wonwook Lee, Tuyen Ngoc Tran, Cha-Hwan Oh
Summary: In this study, a helium atmospheric pressure plasma jet (APPJ) system was constructed to generate two guided streamers. The propagation of the guided streamer and its interaction with a grounded metallic target and pulsed laser were investigated. The results showed that the target extended the lifetime of the plasma radiation and the pulsed laser enhanced the spectra of the helium APPJ. The study also examined the relationship between the time interval of the pulsed laser and the guided streamer and various parameters.
SPECTROCHIMICA ACTA PART B-ATOMIC SPECTROSCOPY
(2023)
Article
Physics, Fluids & Plasmas
Yutian Yu, Li Wu, Qiang Chen, Naoki Shinohara, Kama Huang
Summary: This paper presents a numerical model to simulate the motion trajectory of an atmospheric pressure plasma jet under an external nonuniform electric field. The model treats the plasma jet as equivalent particles based on its dielectric properties and motion characteristics. The model demonstrates short calculation times and excellent agreement with experimental observations, providing an effective and efficient method for predicting and controlling plasma jet motion trajectory.
Article
Physics, Applied
Chenzi Lu, Junlin Fang, Shaofeng Xu, Ying Guo, Jianjun Shi
Summary: A noninvasive method was developed to measure the electrical potential in an atmospheric pressure plasma jet. The study showed that the electrical potential plays a significant role in the propagation of ionization waves, and proposed a new method to manipulate the wave propagation by controlling the amplitude of the electrical potential on the auxiliary electrode.
APPLIED PHYSICS LETTERS
(2023)
Article
Physics, Applied
A. Brisset, P. Tardiveau, K. Gazeli, B. Bournonville, P. Jeanney, K. Ouaras, L. Magne, S. Pasquiers
Summary: The study found that relative humidity has a significant impact on the propagation speed, light intensity, energy, and gas temperature of nanosecond pulsed discharge. Particularly, water vapor content plays an important role in discharge dynamics and light intensity distribution under high electric field conditions. Additionally, there is increased energy consumption and significant heating at the pin in highly humid air.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2021)
Article
Physics, Applied
K. Gazeli, M. Hadjicharalambous, Eleftherios Ioannou, O. Gazeli, C. Lazarou, C. Anastassiou, P. Svarnas, V. Vavourakis, G. E. Georghiou
Summary: We developed an in silico model to simulate the response of B16F10 melanoma cells to a helium atmospheric pressure plasma jet (APPJ) and doxorubicin drug (DOX). The simulation results showed that increasing plasma duration and DOX concentration resulted in increased cytotoxicity and a higher apoptosis probability compared to mitosis probability. Furthermore, combining plasma treatment and drug application enhanced cell cytotoxicity. This in silico model is valuable in the field of plasma medicine for understanding the response of different cancers to APPJ and cancer drugs.
APPLIED PHYSICS LETTERS
(2022)
Article
Energy & Fuels
Maria K. Koukou, Christos Pagkalos, George Dogkas, Michail Gr. Vrachopoulos, Eleni Douvi, Yannis G. Caouris, Polykarpos Papadopoulos
Summary: A numerical study investigated the performance of different phase change materials (PCMs) in a solar collector for thermal storage. The study found that the charging and discharging processes varied for different PCMs.
Article
Physics, Applied
Alice Remigy, Salima Kasri, Thibault Darny, Hiba Kabbara, Ludovic William, Gerard Bauville, Kristaq Gazeli, Stephane Pasquiers, Joao Santos Sousa, Nelson De Oliveira, Nader Sadeghi, Guillaume Lombardi, Claudia Lazzaroni
Summary: This study investigates the micro-hollow cathode discharge operated in Ar/N-2 gas mixture and provides insights into the mechanisms and control of N atom production. The results show that the physical parameters, such as hole diameter and N-2 percentage, greatly affect the density of N atoms.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2022)
Article
Chemistry, Multidisciplinary
Viktoras Papadimas, Christos Doudesis, Panagiotis Svarnas, Polycarpos K. Papadopoulos, George P. Vafakos, Panayiotis Vafeas
Summary: The study has developed a single dielectric barrier discharge-based actuator that is energy-efficient and stable, suitable for different aerodynamic profiles. Experimental results show that the average gas temperature above the actuator surface is around 400K, with fluid velocity reaching up to 4.5m/s, and a laminar flow layer less than 1.5mm thick is observed on the actuator surface.
APPLIED SCIENCES-BASEL
(2021)
Article
Computer Science, Interdisciplinary Applications
Georgios P. Vafakos, Angelos Kafkas, Polycarpos K. Papadopoulos
Summary: This study presents a new version of the pressure-based implicit potential (IPOT) method for incompressible flows, which can be applied on a fully collocated mesh. The new version combines the IPOT algorithm with the Rhie and Chow (RC) technique to produce solutions on collocated grids that are free of spurious pressure modes. The method retains all the benefits of the original algorithm and does not require a special grid topology. The study also discusses the cause of spurious oscillations in zero-div problems and proposes a possible cure linked to the RC technique. The method is validated through several benchmark problems.
INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS
(2022)
Article
Biology
Myrianthi Hadjicharalambous, Eleftherios Ioannou, Nicolas Aristokleous, Kristaq Gazeli, Charalambos Anastassiou, Vasileios Vavourakis
Summary: Anti-angiogenic treatments play a key role in cancer regression by blocking new blood vessel formation and reducing vascular density. This study uses a computational model to investigate the mechanisms of action of anti-angiogenic drugs in tumor regression. The results suggest that combining conventional chemotherapy with anti-angiogenic treatments may be more effective in inhibiting tumor growth.
JOURNAL OF THEORETICAL BIOLOGY
(2022)
Article
Physics, Fluids & Plasmas
A. Remigy, X. Aubert, S. Prasanna, K. Gazeli, L. Invernizzi, G. Lombardi, C. Lazzaroni
Summary: In this study, nanosecond two-photon absorption laser-induced fluorescence (TALIF) is used to measure the density of nitrogen atoms in a plasma generated by a micro-hollow cathode discharge (MHCD). The research shows good agreement between the N-atom density measured using TALIF and previous measurements using vacuum ultraviolet Fourier transform absorption spectroscopy when the pressure is the same on both sides of the electrodes in the MHCD. Additionally, the study explores the impact of discharge current, N-2 percentage in the gas mixture, and pressure differentials on both sides of the MHCD on the N-atom density. It is found that the N-atom density is more sensitive to pressure changes in the low-pressure side of the MHCD.
PHYSICS OF PLASMAS
(2022)
Article
Engineering, Multidisciplinary
Laurent Invernizzi, Corinne Y. Duluard, Hans Hoeft, Khaled Hassouni, Guillaume Lombardi, Kristaq Gazeli, Swaminathan Prasanna
Summary: We present a detailed methodology for accurately capturing and processing ps-TALIF signals of H-atom in low- and atmospheric-pressure plasmas using a streak camera. By carefully configuring the experimental setup and applying mathematical signal processing techniques, we are able to extract the actual shape and decay time of the TALIF signals.
MEASUREMENT SCIENCE AND TECHNOLOGY
(2023)
Article
Physics, Multidisciplinary
D. K. Athanasopoulos, P. Svarnas, C. M. Liapis, P. K. Papadopoulos, K. Gazeli, K. Giotis, P. Vafeas, G. P. Vafakos, V Giannakakis, A. Gerakis
Summary: This study investigates distinct ionization waves using temporally-, spatially-, and wavelength-resolved analyses. Two-dimensional fast imaging technique, ultraviolet to near infrared optical filters, and digital image processing techniques are employed. Emissive neutral and ionic species, as well as NO gamma species, are studied. The study reveals specific emission patterns and measures propagation speeds of the species.
Article
Physics, Fluids & Plasmas
Konstantinos Giotis, Panagiotis Svarnas, Eleftherios Amanatides, Kristaq Gazeli, Guillaume Lombardi, Polykarpos K. Papadopoulos
Summary: This study experimentally investigates a surface dielectric-barrier discharge, which is part of the ongoing research on controlling plasma-induced electro-fluid dynamic effects. A plasma reactor with a fused silica plate and printed circuit boards is used to generate the discharge. By combining electrical and optical analyses with high resolution optical emission spectroscopy and ns-resolved imaging, the discharge characteristics are revealed, with a focus on its propagation along the dielectric-barrier surface. The polarization of the dielectric barrier is found to be critical for the discharge dynamics.
PLASMA SCIENCE & TECHNOLOGY
(2023)
Article
Physics, Applied
J. R. Wubs, L. Invernizzi, K. Gazeli, U. Macherius, X. Lu, L. Schrottke, G. Lombardi, K. -D. Weltmann, J. H. van Helden
Summary: This research demonstrates that Terahertz (THz) absorption spectroscopy is an accurate technique for measuring atomic oxygen densities in plasmas, as it yields similar results to picosecond two-photon absorption laser induced fluorescence (TALIF) measurements. The study shows that both diagnostic methods exhibit similar changes in atomic oxygen density when varying the applied power and gas pressure.
APPLIED PHYSICS LETTERS
(2023)
Correction
Physics, Applied
J. R. Wubs, L. Invernizzi, K. Gazeli, U. Macherius, X. Lu, L. Schrottke, G. Lombardi, K. -D. Weltmann, J. H. van Helden
APPLIED PHYSICS LETTERS
(2023)
Article
Engineering, Environmental
Evangelos Giannakopoulos, Panagiotis Svarnas, Stavroula Dimitriadou, Ioannis Kalavrouziotis, Polycarpos K. Papadopoulos, Stavroula Georga, Christoforos Krontiras
Summary: Biosolids contain high amounts of human pathogenic bacteria that are excreted in feces and urine, potentially causing zoonotic infections and showing strong environmental adaptability. An emerging process using atmospheric pressure air cold plasma of electrical discharges has shown effectiveness in destroying pathogenic cells of antibiotic-resistant bacteria like E. coli and Salmonella sp., providing a potential reduction in pathogenic microorganisms for the reuse of treated biosolids in agriculture.
JOURNAL OF HAZARDOUS TOXIC AND RADIOACTIVE WASTE
(2021)
Article
Physics, Fluids & Plasmas
Panteleimon A. Bakalis, Polycarpos K. Papadopoulos, Panayiotis Vafeas
Summary: The study examined the laminar fully developed ferrofluid flow and heat transfer in a vertical annular duct with circular cross-section, showing significant effects of magnetic field strength and particles' volumetric concentration on velocity distribution, pressure gradient, and heat transfer.
