Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Study by Optical Spectroscopy of Bismuth Emission in a Nanosecond-Pulsed Discharge Created in Liquid Nitrogen.

ABSTRACT: Time-resolved optical emission spectroscopy of nanosecond-pulsed discharges ignited in liquid nitrogen between two bismuth electrodes is used to determine the main discharge parameters (electron temperature, electron density and optical thickness). Nineteen lines belonging to the Bi I system and seven to the Bi II system could be recorded by directly plunging the optical fibre into the liquid in close vicinity to the discharge. The lack of data for the Stark parameters to evaluate the broadening of the Bi I lines was solved by taking advantage of the time-resolved information supported by each line to determine them. The electron density was found to decrease exponentially from 6.5 ± 1.5 × 1016 cm-3 200 ns after ignition to 1.0 ± 0.5 × 1016 cm-3 after 1050 ns. The electron temperature was found to be 0.35 eV, close to the value given by Saha's equation.

SUBMITTER: Nomine AV

PROVIDER: S-EPMC8658815 | biostudies-literature | 2021 Dec

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Study by Optical Spectroscopy of Bismuth Emission in a Nanosecond-Pulsed Discharge Created in Liquid Nitrogen.

Nominé Anna V AV Noel Cédric C Gries Thomas T Nominé Alexandre A Milichko Valentin A VA Belmonte Thierry T

Molecules (Basel, Switzerland) 20211206 23

Time-resolved optical emission spectroscopy of nanosecond-pulsed discharges ignited in liquid nitrogen between two bismuth electrodes is used to determine the main discharge parameters (electron temperature, electron density and optical thickness). Nineteen lines belonging to the Bi I system and seven to the Bi II system could be recorded by directly plunging the optical fibre into the liquid in close vicinity to the discharge. The lack of data for the Stark parameters to evaluate the broadening ...[more]

PMID: 34885986

Similar Datasets

Rapid Elemental Analysis of Aerosols Using Atmospheric Glow Discharge Optical Emission Spectroscopy.

Project description:A new, low-cost approach based on the application of atmospheric radio frequency glow discharge (rf-GD) optical emission spectroscopy (OES) has been developed for near real-time measurement of multielemental concentration in airborne particulate phase. This method involves deposition of aerosol particles on the tip of a cathode in a coaxial microelectrode system, followed by ablation, atomization, and excitation of the particulate matter using the rf-GD. The resulting atomic emissions are recorded using a spectrometer for elemental identification and quantification. The glow discharge plasma in our system was characterized by measuring spatially resolved gas temperatures (378-1438 K) and electron densities (2-5 × 1014 cm-3). Spatial analysis of the spectral features showed that the excitation of the analyte occurred in the region near the collection electrode. The temporal analysis of spectral features in the rf-GD showed that the collected particles were continuously ablated; the time for complete ablation of 193 ng of sucrose particles was found to be approximately 2 s. The system was calibrated using 100 nm particles containing C, Cd, Mn, and Na, respectively. The method provides limits of detection in the range of 0.055-1.0 ng, and a measurement reproducibility of 5-28%. This study demonstrates that the rf-GD can be an excellent excitation source for the development of low-cost hand-held sensors for elemental measurement of aerosols.

| S-EPMC5555147 | biostudies-literature

Species and temperature measurements of methane oxidation in a nanosecond repetitively pulsed discharge.

Project description:Speciation and temperature measurements of methane oxidation during a nanosecond repetitively pulsed discharge in a low-temperature flow reactor have been performed. Measurements of temperature and formaldehyde during a burst of pulses were made on a time-dependent basis using tunable diode laser absorption spectroscopy, and measurements of all other major stable species were made downstream of a continuously pulsed discharge using gas chromatography. The major species for a stoichiometric methane/oxygen/helium mixture with 75% dilution are H(2)O, CO, CO(2), H(2), CH(2)O, CH(3)OH, C(2)H(6), C(2)H(4) and C(2)H(2). A modelling tool to simulate homogeneous plasma combustion kinetics is assembled by combining the ZDPlasKin and CHEMKIN codes. In addition, a kinetic model for plasma-assisted combustion (HP-Mech/plasma) of methane, oxygen and helium mixtures has been assembled to simulate the measurements. Predictions can accurately capture reactant consumption as well as production of the major product species. However, significant disagreement is found for minor species, particularly CH(2)O and CH(3)OH. Further analysis revealed that the plasma-activated low-temperature oxidation pathways, particularly those involving CH(3)O(2) radical reactions and methane reactions with O((1)D), are responsible for this disagreement.

| S-EPMC4528427 | biostudies-literature

Numerical Investigations on Methane-Air Nanosecond Pulsed Dielectric Barrier Discharge Plasma-Assisted Combustion.

Project description:Plasma-assisted combustion is a promising approach to achieve fast ignition and highly efficient combustion. In this work, methane-air nanosecond pulsed dielectric barrier discharge plasma-assisted combustion is numerically investigated by combining a homemade plasma model with the combustion model of software CHEMKIN-PRO. Effects of varying applied voltage amplitudes on the characteristic parameters of the plasma-assisted planar shear flow combustion as well as the reaction pathway maps of not only the nanosecond pulsed dielectric barrier discharge plasma but also the combustions without and with plasma assistance are systematically illustrated and analyzed. The simulation results indicate that under the combined action of increasing electric field intensity and increasing charged particle densities, the peak value of the discharge current density increases, and the peak time of the discharge current density is brought forward with the increase of the applied voltage amplitude. The temperature reaches its peak value earlier in the methane-air combustion with plasma assistance than without plasma assistance. The maximum temperature reduces to around 1900 K when the applied voltage amplitude is higher than 11 kV. There are emerging pathways to generate hydrocarbons C2H4 and C2H2 in the plasma-assisted combustion, the reactions of CH4 on CH and C2H on H2, respectively. The reactions involving active species such as H play a significant role in the plasma-assisted combustion, which causes an obvious decrease in the densities of these active species with plasma assistance.

| S-EPMC7745419 | biostudies-literature

Gene expression induced by Nanosecond pulsed electric fields

Project description:We use a human whole genome microarray to analyze the effects of nanosecond pulsed electric fields on Jurkat cells with the focus on early response genes to DNA damage. Keywords: nanosecond pulsed electric fields, jurkat cells, DNA damage

2006-02-01 | GSE4106 | GEO

Methane-Air Plasma-Assisted Ignition Excited by Nanosecond Repetitively Pulsed Discharge: Numerical Modeling and Effect of Inert Gas.

Project description:Plasma-assisted ignition and combustion are promising approaches for controlling ignition enhancement and flame stabilization. The global loosely coupled plasma-assisted combustion kinetic model has been established by combining the ZDPlasKin and ChemKin codes, which is employed to numerically investigate the effects of the inert gas-diluted methane-air nanosecond repetitively pulsed (NRP) plasma on the ignition process. The results indicate that addition of the inert gas is conducive to increasing the chemical reactive species densities in the methane-air NRP discharge plasma. The addition of inert gases affects the generation pathways of plasma species and their corresponding contribution rates. Compared with the methane-air plasma, the dilution of inert gases shows obvious effects on reducing ignition delays, and the dilution of He and Ar decreases the ignition delays by 58.0 and 84.0%, respectively. CH3 + O2 = CH3O + O and H + O2 = O + OH are the dominant conducive reactions in the methane-air ignition chemistry. Moreover, the dilution of inert gases has considerable influences on the normalization sensitivity coefficients, especially for the reaction of H + O2 = O + OH.

| S-EPMC8459428 | biostudies-literature

Pulsed Corona Discharge Induced Hydroxyl Radical Transfer Through the Gas-Liquid Interface.

Project description:The highly energetic electrons in non-thermal plasma generated by gas phase pulsed corona discharge (PCD) produce hydroxyl (OH) radicals via collision reactions with water molecules. Previous work has established that OH radicals are formed at the plasma-liquid interface, making it an important location for the oxidation of aqueous pollutants. Here, by contacting water as aerosol with PCD plasma, it is shown that OH radicals are produced on the gas side of the interface, and not in the liquid phase. It is also demonstrated that the gas-liquid interfacial boundary poses a barrier for the OH radicals, one they need to cross for reactive affinity with dissolved components, and that this process requires a gaseous atomic H scavenger. For gaseous oxidation, a scavenger, oxygen in common cases, is an advantage but not a requirement. OH radical efficiency in liquid phase reactions is strongly temperature dependent as radical termination reaction rates increase with temperature.

| S-EPMC5700971 | biostudies-literature

Resonant secondary light emission from plasmonic Au nanostructures at high electron temperatures created by pulsed-laser excitation.

Project description:Plasmonic nanostructures are of great current interest as chemical sensors, in vivo imaging agents, and for photothermal therapeutics. We study continuous-wave (cw) and pulsed-laser excitation of aqueous suspensions of Au nanorods as a model system for secondary light emission from plasmonic nanostructures. Resonant secondary emission contributes significantly to the background commonly observed in surface-enhanced Raman scattering and to the light emission generated by pulsed-laser excitation of metallic nanostructures that is often attributed to two-photon luminescence. Spectra collected using cw laser excitation at 488 nm show an enhancement of the broad spectrum of emission at the electromagnetic plasmon resonance of the nanorods. The intensity of anti-Stokes emission collected using cw laser excitation at 785 nm is described by a 300 K thermal distribution of excitations. Excitation by subpicosecond laser pulses at 785 nm broadens and increases the intensity of the anti-Stokes emission in a manner that is consistent with electronic Raman scattering by a high-temperature distribution of electronic excitations predicted by a two-temperature model. Broadening of the pulse duration using an etalon reduces the intensity of anti-Stokes emission in quantitative agreement with the model. Experiments using a pair of subpicosecond optical pulses separated by a variable delay show that the timescale of resonant secondary emission is comparable to the timescale for equilibration of electrons and phonons.

| S-EPMC3903255 | biostudies-literature

Gene electrotransfer enhanced by nanosecond pulsed electric fields.

Project description:The impact of nanosecond pulsed electric fields (nsPEFs) on gene electrotransfer has not been clearly demonstrated in previous studies. This study was conducted to evaluate the influence of nsPEFs on the delivery of plasmids encoding luciferase or green fluorescent protein and subsequent expression in HACAT keratinocyte cells. Delivery was performed using millisecond electric pulses (msEPs) with or without nsPEFs. In contrast to reports in the literature, we discovered that gene expression was significantly increased up to 40-fold by applying nsPEFs to cells first followed by one msEP but not in the opposite order. We demonstrated that the effect of nsPEFs on gene transfection was time restricted. The enhancement of gene expression occurred by applying one msEP immediately after nsPEFs and reached the maximum at posttreatment 5 minutes, slightly decreased at 15 minutes and had a residual effect at 1 hour. It appears that nsPEFs play a role as an amplifier without changing the trend of gene expression kinetics due to msEPs. The effect of nsPEFs on cell viability is also dependent on the specific pulse parameters. We also determined that both calcium independent and dependent mechanisms are involved in nsPEF effects on gene electrotransfer.

| S-EPMC4362372 | biostudies-literature

Preparation of few-layer bismuth selenide by liquid-phase-exfoliation and its optical absorption properties.

Project description:Bismuth selenide (Bi2Se3), a new topological insulator, has attracted much attention in recent years owing to its relatively simple band structure and large bulk band gap. Compared to bulk, few-layer Bi2Se3 is recently considered as a highly promising material. Here, we use a liquid-phase exfoliation method to prepare few-layer Bi2Se3 in N-methyl-2-pyrrolidone or chitosan acetic solution. The resulted few-layer Bi2Se3 dispersion demonstrates an interesting absorption in the visible light region, which is different from bulk Bi2Se3 without any absorption in this region. The absorption spectrum of few-layer Bi2Se3 depends on its size and layer number. At the same time, the nonlinear and saturable absorption of few-layer Bi2Se3 thin film in near infrared is also characterized well and further exploited to generate laser pulses by a passive Q-switching technique. Stable Q-switched operation is achieved with a lower pump threshold of 9.3 mW at 974 nm, pulse energy of 39.8 nJ and a wide range of pulse-repetition-rate from 6.2 to 40.1 kHz. Therefore, the few-layer Bi2Se3 may excite a potential applications in laser photonics and optoelectronic devices.

| S-EPMC3999456 | biostudies-literature

Adhesive Leaf Created by a Corona Discharge.

Project description:Here, we report a new concept of both the adhesive manner and material, named "adhesive leaf (AL)," based on the leaf of the plant Heteropanax fragrans. The treatment of the corona discharge on the leaf surface can cause the nano-/microdestruction of the leaf epidermis, resulting in an outward release of sap. The glucose-containing sap provided the AL with a unique ability to stick to various substrates such as steel, polypropylene, and glass. Moreover, we reveal that the AL adhesion strength depends on the AL size, as well as the corona-discharge intensity. Conventional adhesives, such as glue and bond, lose their adhesive property and leave dirty residues upon the removal of the attached material. Unlike the conventional methods, the AL is advantageous as it can be repeatedly attached and detached thoroughly until the sap liquid is exhausted; its adhesive ability is maintained for at least three weeks at room temperature. Our findings shed light on a new concept of a biodegradable adhesive material that is created by a simple surface treatment.

| S-EPMC5788921 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data