A5067768327- Plasma Diagnostics and Applications
- Plasma Applications and Diagnostics
- Electrohydrodynamics and Fluid Dynamics
- Ionosphere and magnetosphere dynamics
- Laser-induced spectroscopy and plasma
- Nuclear Physics and Applications
- Solar and Space Plasma Dynamics
- Radiation Detection and Scintillator Technologies
- Geophysics and Gravity Measurements
- Gas Sensing Nanomaterials and Sensors
- Dust and Plasma Wave Phenomena
- Gyrotron and Vacuum Electronics Research
- Analytical Chemistry and Sensors
- Lignin and Wood Chemistry
- Radioactive Decay and Measurement Techniques
- Mass Spectrometry Techniques and Applications
- Combustion and flame dynamics
- Radiation Therapy and Dosimetry
- Scientific Measurement and Uncertainty Evaluation
- GNSS positioning and interference
- High-Temperature Coating Behaviors
- Radiation Shielding Materials Analysis
- Melamine detection and toxicity
- Particle Detector Development and Performance
- Biochemical and biochemical processes
Instituto Tecnológico de Aeronáutica
2015-2025
Instituto de Aeronáutica e Espaço
2015-2025
University of Iowa
2023
Nagoya University
2023
Los Alamos National Laboratory
2023
Memorial University of Newfoundland
2023
Planetary Science Institute
2023
Marshall Space Flight Center
2023
Goddard Space Flight Center
2023
University of Colorado System
2023
This study investigates how different assumptions about the velocity distribution of negative ions in electronegative plasmas influence Bohm criterion and resulting velocities at sheath edge. An expression for is derived a multicomponent plasma with non-collisional sheaths, generalized electron ion functions form f(v)=A exp(−Bv2ξ), where ξ positive real number greater than 0.5. Additionally, method presented computing any given function f(v). For simple three-component consisting electrons,...
Abstract We examined the electrodynamic impact of four geomagnetic storms increasing intensities on equatorial ionosphere: a moderate storm (27–28 September 2017), strong (17–18 April 2002), severe (07–08 and an extreme (09–10 November 2004). Using Jicamarca incoherent scatter radar data, we analyzed F‐region height‐averaged vertical drift residuals to study perturbations in zonal electric field, including effects from interplanetary magnetic field (IMF) B z component, substorms, ionospheric...
Mass spectrometry was used to monitor neutral chemical species from sugar cane bagasse that could volatilize during the ozonation process. Lignin fragments and some radicals liberated by direct ozone reaction with biomass structure were detected. Ozone density monitored optical absorption spectroscopy. The results indicated interaction material better for particle sizes less than or equal 0.5 mm. Both techniques have shown best condition diffusion in at 50% of its moisture content. In...
Abstract An atmospheric argon rf microplasma jet was employed to treat lignin samples. The treatment time carried out from 30 min 4 h resulting in a strong degradation of the structure. most important observed functional groups having asymmetric in‐phase ring stretching as well CC and CO vibrations. Simple calculations may help us explain OH bond breakings by electron collisions inside microplasma. In afterglow condition, it not any change on spectra.
In this work we compute the main features of a surface-wave-driven plasma in argon at atmospheric pressure view better understanding contraction phenomenon. We include detailed chemical kinetics dynamics Ar and solve mass conservation equations relevant neutral excited charged species. The gas temperature radial profile is calculated by means thermal diffusion equation. electric field directly from numerical solution Maxwell assuming surface wave to be propagating TM_{00} mode. problem...
The homogeneous Boltzmann equation for electrons in N2, O2 and H2 is solved under the classical two-term approximation, reduced electric fields interval 10 − 4 −10 Td where electron-neutral encounters are limited to elastic, rotational vibrational collisions. Rotational excitations/de-excitations described using following three different approaches: discrete inelastic/superelastic collisional operator, written a number of levels that depends on molecular gas specific cross sections...
A surface wave discharge (SWD) in argon at atmospheric pressure generated by a surfatron device was studied optical emission spectroscopy (OES). Two distinct situations were investigated; (i) plasma open air and (ii) totally confined quartz tube. The electron density ne, temperature Te gas Tg investigated as function of applied power flow rate. self-absorbing method used to estimate the population metastable state Ar(1s5). These physical quantities determined through measurements along axis...
In this work, we report the results from an optical emission spectroscopy experiment designed to investigate molecular emissions a plasma jet produced by high velocity spray (HVPS). By fitting spectra, were able infer rotational temperature of electronic excited molecules OH (A <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$^{2}\Sigma^{+}$</tex-math> </inline-formula> ), CN (B N...
Surface-wave discharges in argon at atmospheric pressure were experimentally studied by optical emission spectroscopy (OES) and mass spectrometry (MS). OES was employed to determine the rotational temperature using ultraviolet OH band, Q1 branch found be between 450 970 K. The electron density (5 × 1013 cm−3 ≤ ne 7 1014 cm−3) estimated Hβ line profile, produced dissociation of water present as an impurity Ar gas. (0.63 eV Te 1.3 eV) a collisional–radiative (CR) model that takes input...
In this work studies of the first Townsend coefficient (α) behavior in isobutane for reduced electric fields ranging from l39Td up to 2O8Td are presented. Pure has been widely used Resistive Plate Chambers (RPCs) and other gaseous detectors because its excellent timing properties. Regardless these characteristics, there is a lack swarm parameters data literature gas. The measurements were based on Pulsed technique. Considering ratio between current, measured avalanche mode, primary...
Abstract In this paper, we applied a variety of statistical methods to study gravity waves in the troposphere and lower stratosphere Brazilian sector, using large database from Instituto de Controle do Espaço Aéreo (ICEA) radiosonde measurements carried out 2014 at 32 locations territory totaling 49,652 wind temperature profiles. The average profiles were computed classified by means hierarchical cluster analysis. kinetic potential energy densities determined detrending technique based on...
Neste trabalho, propomos um método experimental para medir a velocidade do som por meio efeito Doppler gerado fonte sonora em rotação. Esse é comparado com o mais convencional, comumente designado experimento tubo ressonante, baseado na medição das frequências de ressonância acústica uma extremidades fechadas. Embora uso didático girante demonstração não seja novidade, encontramos literatura procedimento detalhado aquisição e tratamento quantitativo dados que leve conta descrição completa da...
Views Icon Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Twitter Facebook Reddit LinkedIn Tools Reprints and Permissions Cite Search Site Citation M. A. Ridenti, T. C. Vivaldini, I. B. Lima, P. R. Pascholati; A Method for Evaluating Electron Transport Parameters on a Pulsed Townsend Experiment. AIP Conf. Proc. 21 May 2010; 1245 (1): 92–97. https://doi.org/10.1063/1.3448019 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley...
A microwave surface-wave discharge at atmospheric pressure was generated using a He/H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O mixture and studied by optical emission spectroscopy. The main plasma parameters were determined based on the analysis of spectra when partial thermodynamic equilibrium could be verified. showed that system can classified as warm with an average gas temperature 1.7 × 10 <sup...
In this work we present some results from a numerical solution of the homogeneous electron Boltzmann equation (EBE) for electrons in an uniform electric field, using classical two term expansion. This EBE solver was specially designed to be used as part global models low temperature plasmas. It accounts oscillating fields, electron-neutral collisions and electron-electron collisions. order validate solver, compare calculated transport parameters with experimental data swarm experiments N2 Ar.
We present a model that describes the departure from equilibrium of OH(A) rotational level distribution in collisional plasmas. In this model, state densities are governed by rate equation including: (i) balanced energy transfer process with buffer gas species; (ii) unbalanced exothermic reactions, which pump rotationally excited states into system. Based on prior assumptions, we formally derive function describing non-Boltzmann distribution. This depends five parameters, each has physical...
By applying mass spectrometry techniques, we carried out measurements of ionic spectrum and their energy distribution in order to investigate an atmospheric argon discharge by using a surfatron surface-wave device. The were performed with fixed flow rate (2.5 SLM) pure gas (99.999%) different Ar-O2 mixture compositions (99-1, 98-2 97-3). spectra distributions recorded for Ar+, O+, O+2, N+ N2+. axial profiles obtained experimental conditions as function the plasma length. results showed that...
Views Icon Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Twitter Facebook Reddit LinkedIn Tools Reprints and Permissions Cite Search Site Citation Iara B. Lima, Túlio C. Vivaldini, Josemary A. Gonçalves, Suzana Botelho, Marco Ridenti, Paulo Fonte, Alessio Mangiarotti, R. Pascholati, Carmen Bueno Tobias; Studies of Gaseous Multiplication Coefficient in Isobutane. AIP Conference Proceedings 21 May 2010; 1245 (1): 149–152. https://doi.org/10.1063/1.3448007...