Showing papers on "Atmospheric pressure published in 2010"
TL;DR: Interestingly, graphene syntheses using a Cu catalyst in APCVD processes at higher methane concentrations revealed that the growth is not self-limiting, which is in contrast to previous observations for the LPCVD case.
Abstract: In this article, the role of kinetics, in particular, the pressure of the reaction chamber in the chemical vapor deposition (CVD) synthesis of graphene using low carbon solid solubility catalysts (Cu), on both the large area thickness uniformity and the defect density are presented. Although the thermodynamics of the synthesis system remains the same, based on whether the process is performed at atmospheric pressure (AP), low pressure (LP) (0.1−1 Torr) or under ultrahigh vacuum (UHV) conditions, the kinetics of the growth phenomenon are different, leading to a variation in the uniformity of the resulting graphene growth over large areas (wafer scale). The kinetic models for APCVD and LPCVD are discussed, thereby providing insight for understanding the differences between APCVD vs LPCVD/UHVCVD graphene syntheses. Interestingly, graphene syntheses using a Cu catalyst in APCVD processes at higher methane concentrations revealed that the growth is not self-limiting, which is in contrast to previous observatio...
793 citations
TL;DR: In this paper, an Atmospheric Pressure Interface Time-of-Flight Mass Spectrometer (APi-TOF, Tofwerk AG) was used to detect the composition of ambient ions in the mass/charge range up to 2000 Th.
Abstract: . In this paper we present recent achievements on developing and testing a tool to detect the composition of ambient ions in the mass/charge range up to 2000 Th. The instrument is an Atmospheric Pressure Interface Time-of-Flight Mass Spectrometer (APi-TOF, Tofwerk AG). Its mass accuracy is better than 0.002%, and the mass resolving power is 3000 Th/Th. In the data analysis, a new efficient Matlab based set of programs (tofTools) were developed, tested and used. The APi-TOF was tested both in laboratory conditions and applied to outdoor air sampling in Helsinki at the SMEAR III station. Transmission efficiency calibrations showed a throughput of 0.1–0.5% in the range 100–1300 Th for positive ions, and linearity over 3 orders of magnitude in concentration was determined. In the laboratory tests the APi-TOF detected sulphuric acid-ammonia clusters in high concentration from a nebulised sample illustrating the potential of the instrument in revealing the role of sulphuric acid clusters in atmospheric new particle formation. The APi-TOF features a high enough accuracy, resolution and sensitivity for the determination of the composition of atmospheric small ions although the total concentration of those ions is typically only 400–2000 cm−3. The atmospheric ions were identified based on their exact masses, utilizing Kendrick analysis and correlograms as well as narrowing down the potential candidates based on their proton affinities as well isotopic patterns. In Helsinki during day-time the main negative ambient small ions were inorganic acids and their clusters. The positive ions were more complex, the main compounds were (poly)alkyl pyridines and – amines. The APi-TOF provides a near universal interface for atmospheric pressure sampling, and this key feature will be utilized in future laboratory and field studies.
403 citations
TL;DR: In this article, the primary principles and characteristics of the cold atmospheric plasma and differences from vacuum-based plasma processes are described and discussed to provide a better understanding of the capabilities and limits of emerging atmospheric plasma technologies.
370 citations
TL;DR: An atmospheric pressure plasma jet generated in Ar/water vapor mixtures has been investigated and the effect of water content on plasma properties has been studied as mentioned in this paper, where the gas temperature increases with the addition of water to feed gas from 620 K in pure Ar up to 1130 K for 0.76% H2O.
Abstract: An atmospheric pressure plasma jet generated in Ar/water vapor mixtures has been investigated and the effect of water content on plasma properties has been studied. Plasma generated in Ar/water (0.05%) mixture shows higher intensity of OH radicals in emission spectra than pure argon alone. Plasma density has been estimated from current measurement and is in order of 1.5×1013 cm−3. Electron temperature has been estimated as 0.97 eV in pure Ar and it decreases with an increase in water content in plasma. The gas temperature has been determined by fitting of the experimental spectra and using the Boltzmann plot method. The gas temperature increases with the addition of water to feed gas from 620 K in pure Ar up to 1130 K for 0.76% H2O.
266 citations
TL;DR: In this article, the experimental conditions necessary for the glow regime of NRP discharges have been determined, with the notable result that there exists a minimum and maximum gap distance for its existence at a given ambient gas temperature.
Abstract: In atmospheric pressure air preheated from 300 to 1000 K, the nanosecond repetitively pulsed (NRP) method has been used to generate corona, glow, and spark discharges. Experiments have been performed to determine the parameter space (applied voltage, pulse repetition frequency, ambient gas temperature, and interelectrode gap distance) of each discharge regime. In particular, the experimental conditions necessary for the glow regime of NRP discharges have been determined, with the notable result that there exists a minimum and maximum gap distance for its existence at a given ambient gas temperature. The minimum gap distance increases with decreasing gas temperature, whereas the maximum does not vary appreciably. To explain the experimental results, an analytical model is developed to explain the corona-to-glow (C-G) and glow-to-spark (G-S) transitions. The C-G transition is analyzed in terms of the avalanche-to-streamer transition and the breakdown field during the conduction phase following the establish...
250 citations
TL;DR: In this article, the authors provide a basic framework for atmospheric pressure radical production in atmospheric pressure plasmas and show that accurate knowledge of ne, Te, Tg, the dominant ionic species, radical and neutral species are indispensable to obtain a complete view on the chemical kinetics in these challenging complex atmospheric pressure Plasmas.
Abstract: In this paper radical production in atmospheric pressure water containing plasmas is discussed. As OH is often an important radical in these discharges the paper focuses on OH production.Besides nanosecond pulsed coronas and diffusive glow discharges, several other atmospheric pressure plasmas which are of interest nowadays have a typical electron temperature in the range 1–2 eV and an ionization degree of 10−5–10−4. These properties are quite different from the typical plasma properties known from low pressure gas discharges.In the plasma physics literature OH production is primarily ascribed to be due to electron, metastable induced or thermal dissociation of water, processes which are dominant in (low pressure) gas discharges and in combustion and hot flames. It is shown in this paper that for several atmospheric pressure plasmas also dissociative recombination can be an effective method of OH radical production. Several examples are presented in detail.This paper provides a basic framework for OH production in atmospheric pressure plasmas and shows that accurate knowledge of ne, Te, Tg, the dominant ionic species, radical and neutral species are indispensable to obtain a complete view on the chemical kinetics in these challenging complex atmospheric pressure plasmas. A few relevant plasma diagnostics together with their limitations are also briefly discussed in this context.
237 citations
TL;DR: In this article, a radio-frequency driven micro-atmospheric pressure plasma jet is investigated using both advanced optical diagnostics and numerical simulations of the dynamic plasma chemistry, showing that the main production mechanisms are electron induced and hence most efficient in the vicinity of the plasma boundary sheath, where electrons are energized.
Abstract: Atomic oxygen formation in a radio-frequency driven micro-atmospheric pressure plasma jet is investigated using both advanced optical diagnostics and numerical simulations of the dynamic plasma chemistry. Laser spectroscopic measurements of absolute densities of ground state atomic oxygen reveal steep gradients at the interface between the plasma core and the effluent region. Spatial profiles resolving the interelectrode gap within the core plasma indicate that volume processes dominate over surface reactions. Details of the production and destruction processes are investigated in numerical simulations benchmarked by phase-resolved optical emission spectroscopy. The main production mechanisms are electron induced and hence most efficient in the vicinity of the plasma boundary sheath, where electrons are energized. The destruction is driven through chemical heavy particle reactions. The resulting spatial profile of atomic oxygen is relatively flat. The power dependence of the atomic oxygen density obtained by the numerical simulation is in very good agreement with the laser spectroscopic measurements.
229 citations
TL;DR: In this paper, in situ optical diagnostic techniques were developed to understand the physico-chemical mechanisms that control the number densities of active species, and the effects of these discharges on the chemistry are discussed.
Abstract: Nanosecond repetitively pulsed (NRP) discharges were used to generate atmospheric pressure plasmas in air or nitrogen preheated at 1000?K. In order to understand the physico-chemical mechanisms that control the number densities of active species, in situ optical diagnostic techniques were developed. The ground state of atomic oxygen was measured by two-photon absorption laser induced fluorescence (TALIF), the density of N2(A) was measured by cavity ring down spectroscopy (CRDS) and the densities of N2(B) and N2(C) were measured by optical emission spectroscopy (OES). Temporally and spatially resolved density measurements were performed in the main operating regimes of the NRP discharge, namely the diffuse and filamentary regimes. The diagnostic techniques and associated challenges are presented and the effects of these discharges on the chemistry are discussed.
222 citations
TL;DR: In this paper, the authors evaluated the performance of atmospheric pressure dielectric barrier discharges for the conversion of greenhouse gases into useful compounds, and showed that the most important parameter affecting the CO2-conversion levels is the gas flow rate.
Abstract: The aim of this work consists of the evaluation of atmospheric pressure dielectric barrier discharges for the conversion of greenhouse gases into useful compounds. Therefore, pure CO2 feed flows are administered to the discharge zone at varying discharge frequency, power input, gas temperature and feed flow rates, aiming at the formation of CO and O2. The discharge obtained in CO2 is characterized as a filamentary mode with a microdischarge zone in each half cycle of the applied voltage. It is shown that the most important parameter affecting the CO2-conversion levels is the gas flow rate. At low flow rates, both the conversion and the CO-yield are significantly higher. In addition, also an increase in the gas temperature and the power input give rise to higher conversion levels, although the effect on the CO-yield is limited. The optimum discharge frequency depends on the power input level and it cannot be unambiguously stated that higher frequencies give rise to increased conversion levels. A maximum CO2 conversion of 30% is achieved at a flow rate of 0.05Lmin −1 , a power density of 14.75Wcm −3 and a frequency of 60kHz. The most energy efficient conversions are achieved at a flow rate of 0.2Lmin −1 , a power density of 11Wcm −3 and a discharge frequency of 30kHz. (Some figures in this article are in colour only in the electronic version)
192 citations
TL;DR: In this article, the results of a two-dimensional numerical simulation of positive streamer propagation in atmospheric-pressure helium jets injected into ambient air are presented, and it is shown that depending on the jet width and the initial radial distribution of electron number density streamer structures of two types can be formed: one with maxima of electric field and electron density at the jet axis, and another with maximum of these parameters near the boundary between the jet and surrounding air.
Abstract: The results of a two-dimensional numerical simulation of positive streamer propagation in atmospheric-pressure helium jets injected into ambient air are presented. It is shown that depending on the jet width and the initial radial distribution of electron number density streamer structures of two types can be formed: one with maxima of electric field and electron density at the jet axis and another with maxima of these parameters near the boundary between the jet and surrounding air. The latter structure is similar to the observed ring-shaped structures of plasma bullets.
172 citations
TL;DR: A two-dimensional model coupling Maxwell equations with plasma fluid equations is used to describe the formation of patterns under conditions similar to recent experiments and for a wave electric field perpendicular to the simulation domain or in the simulationdomain.
Abstract: High power microwave breakdown at atmospheric pressure leads to the formation of filamentary plasma arrays that propagate toward the source. A two-dimensional model coupling Maxwell equations with plasma fluid equations is used to describe the formation of patterns under conditions similar to recent experiments and for a wave electric field perpendicular to the simulation domain or in the simulation domain. The calculated patterns are in excellent qualitative agreement with the experiments, with good quantitative agreement of the propagation speed of the filaments. The propagation of the plasma filaments is due to the combination of diffusion and ionization. Emphasis is put on the fact that free electron diffusion (and not ambipolar diffusion) associated with ionization is responsible for the propagation of the front.
TL;DR: A mass spectrometer interface for planar geometries is constructed that takes advantage of atmospheric pressure gas dynamic principles, rather than ion focusing, to minimize ion losses from diffusion in the analyzer and to maximize total ion transport into the mass spectromaeter.
TL;DR: In this paper, the degradation of anthocyanins (pelargonidin-3-glucoside) in a strawberry paste during high-temperature/high-pressure treatments was investigated over a temperature range of 80 −130 −C and a pressure range of 200 −700 −MPa.
TL;DR: In this paper, a simple collisional?radiative model for the Paschen 1s and 2p levels is proposed for low-temperature argon discharges.
Abstract: A simple collisional?radiative model for the Paschen 1s and 2p levels is proposed for low-temperature argon discharges. This model can predict the population distribution of 1s and 2p levels over a wide discharge pressure range 1?105?Pa and ionization ratio range 10?6?10?3. The modelling results are found to be in good agreement with observed optical emissions from several different types of argon discharges at 1, 100 and 105?Pa. By using the model, the dominant kinetic processes of 1s and 2p levels are investigated for an electron beam plasma, an inductively coupled plasma, a capacitively coupled plasma and a microwave microplasma. A kinetic diagram is given, which can be used to identify the kinetic state of 1s and 2p levels in many low-temperature argon discharges reported in the literature. This model is also useful for obtaining discharge parameters from optical emissions in low-temperature argon discharges.
TL;DR: In this article, it was shown that electronic quenching of OH(A) by water prevents thermalization of the rotational population distribution of OH (A), which is determined not only by the gas temperature but also by the formation of negative ions and clusters for larger water concentrations.
Abstract: In this paper it is shown that electronic quenching of OH(A) by water prevents thermalization of the rotational population distribution of OH(A). This means that the observed ro-vibrational OH(A?X) emission band is (at least partially) an image of the formation process and is determined not only by the gas temperature. The formation of negative ions and clusters for larger water concentrations can contribute to the non-equilibrium. The above is demonstrated in RF excited atmospheric pressure glow discharges in He?water mixtures in a parallel metal plate reactor by optical emission spectroscopy. For this particular case a significant overpopulation of high rotational states appears around 1000?ppm H2O in He. The smallest temperature parameter of a non-Boltzmann (two-temperature) distribution fitted to the experimental spectrum of OH(A?X) gives a good representation of the gas temperature. Only the rotational states with the smallest rotational numbers (J ? 7) are thermalized and representative for the gas temperature.
TL;DR: In this paper, the authors employ atmospheric pressure photoionization Fourier transform ion cyclotron mass spectrometry to monitor the evolution of the asphaltene hydrocarbon and sulfur families in deep hydrotreatment processes (fixed and ebullated beds).
Abstract: The compositional analysis (speciation) of heavy oil products is a key step to improve our understanding of hydrotreatment processes and reaction mechanisms. Thus, detailed characterization of polar fractions, such as asphaltenes, should be considered. Here, we employ atmospheric pressure photoionization Fourier transform ion cyclotron mass spectrometry to monitor the evolution of the asphaltene hydrocarbon and sulfur families in deep hydrotreatment processes (fixed and ebullated beds). The results suggest that the complexity of the asphaltenic fractions (in terms of chemical polydispersity) is drastically lowered with increased process severity. In either fixed or ebullated beds, the evolution of the sulfur species is quite similar in class composition, aromaticity (DBE/carbon number ratio), and polycondensation (DBE). The compositional changes are marked by a drastic increase in aromaticity to highly polycondensed dealkylated aromatic structures. Asphaltene disaggregation followed by a dealkylation of t...
TL;DR: In this article, a 2 in. wide plasma beam, operating at 250 W, 1.0 l/min O2, 30 L/min He, and a source-to-sample distance of 3±0.1 mm, was scanned over the sample at 100±2
Abstract: Silicon (100) surfaces were converted to a hydrophilic state with a water contact angle of <5° by treatment with a radio frequency, atmospheric pressure helium, and oxygen plasma. A 2 in. wide plasma beam, operating at 250 W, 1.0 l/min O2, 30 l/min He, and a source-to-sample distance of 3±0.1 mm, was scanned over the sample at 100±2 mm/s. Plasma oxidation of HF-etched silicon caused the dispersive component of the surface energy to decrease from 55.1 to 25.8 dyn/cm, whereas the polar component of the surface energy increased from 0.3 to 42.1 dyn/cm. X-ray photoelectron spectroscopy revealed that the treatment generated a monolayer of covalently bonded oxygen on the Si(100) surface 0.15±0.10 nm thick. The surface oxidation kinetics have been measured by monitoring the change in water contact angle with treatment time, and are consistent with a process that is limited by the mass transfer of ground-state oxygen atoms to the silicon surface.
TL;DR: In this paper, sub-microsecond pulsed atmospheric air plasmas are shown to produce a low concentration of excited oxygen atoms but an abundance of excited nitrogen species, UV photons and ozone molecules.
Abstract: Glow discharges in air are often considered to be the ultimate low-temperature atmospheric pressure plasmas for numerous chamber-free applications. This is due to the ubiquitous presence of air and the perceived abundance of reactive oxygen and nitrogen species in air plasmas. In this paper, sub-microsecond pulsed atmospheric air plasmas are shown to produce a low concentration of excited oxygen atoms but an abundance of excited nitrogen species, UV photons and ozone molecules. This contrasts sharply with the efficient production of excited oxygen atoms in comparable helium–oxygen discharges. Relevant reaction chemistry analysed with a global model suggests that collisional excitation of O2 by helium metastables is significantly more efficient than electron dissociative excitation of O2, electron excitation of O and ion–ion recombination. These results suggest different practical uses of the two oxygen-containing atmospheric discharges, with air plasmas being well suited for nitrogen and UV based chemistry and He–O2 plasmas for excited atomic oxygen based chemistry.
TL;DR: In this paper, the authors show that as pressure is decreased from atmosphere to a few torr, the discharge transitions from a well-defined array to a smeared-out array and finally to a diffuse plasma.
Abstract: Recent studies of 110 GHz microwave discharges in air at atmospheric pressure have demonstrated formation of a large array of quarter-wavelength-spaced plasma filaments. Here we present measurements showing that as pressure is decreased from atmosphere to a few torr, the discharge transitions from a well-defined array to a smeared-out array and finally to a diffuse plasma. Despite the distinct nature of breakdown phenomena at high microwave frequencies, the pressure dependence of the breakdown threshold field is seen to follow a Paschen-type curve. Data for air and argon at 110 GHz are compared with previous low-frequency data.
TL;DR: Dielectric spectroscopy was used to investigate the relaxation dynamics of supercooled and glassy ibuprofen at various isobaric and isothermal conditions and revealed validity of temperature-pressure superpositioning (TPS) for the alpha-peak.
Abstract: Dielectric spectroscopy (DS) was used to investigate the relaxation dynamics of supercooled and glassy ibuprofen at various isobaric and isothermal conditions (pressure up to 1750 MPa). The ambient pressure data are in good agreement with that reported previously in the literature. Our high pressure measurements revealed validity of temperature−pressure superpositioning (TPS) for the α-peak. We also found that the value of the fragility index decreases with compression from m = 87 ± 2 at atmospheric pressure to m = 72.5 ± 3.5 at high pressure (p = 920 MPa). The drop of fragility observed in our experiment was discussed in the framework of the two-order-parameter (TOP) model. In addition, we have also studied crystallization kinetics in a liquid state of examined drug at ambient and high pressure. We found out that, for the same structural relaxation time/same viscosities, the samples prepared by compression of liquid at high temperatures have significantly elongated induction times as well as overall crys...
TL;DR: In this paper, a wire-cylinder-plate electrode configuration is presented to generate ionic wind with a dc corona discharge in air at atmospheric pressure, where the goal is to maximize the power supplied to the flow in order to increase acceleration while avoiding breakdown.
Abstract: A wire-cylinder-plate electrode configuration is presented to generate ionic wind with a dc corona discharge in air at atmospheric pressure. The objective of the work is to maximize the power supplied to the flow in order to increase acceleration while avoiding breakdown. Thus, the proposed experimental setup addresses the problem of decoupling the mechanism of ion generation from that of ion acceleration. Using a wire-plate configuration as a reference, we have focused on improving the topography of the electric field to (1) separate the ionization and acceleration zones in space, and (2) guide the trajectory of charged particles as parallel to the median axis as possible. In the proposed wire-cylinder-plate setup, a dc corona discharge is generated in the space between a wire and two cylinders. The ions produced by the corona then drift past the cylinders and into a channel between two plates, where they undergo acceleration. To maximize the ionic wind it is found that the geometric configuration must be as compact as possible and that the voltage applied must be right below breakdown. Experimentally, the optimized wire-plate reference setup provides a maximum flow velocity of 8 m s−1, a flow rate per unit electrode length of 0.034 m2 s−1, and a thrust per unit electrode length of 0.24 N m−1. The wire-cylinder-plate configuration provides a maximum flow velocity of 10 m s−1, a flow rate per unit electrode length of 0.041 m2 s−1, and a thrust per unit electrode length of 0.35 N m−1. This 46% increase in thrust is obtained by increasing the electric power per unit electrode length by only 16% (from 175 to 210 W m−1), which confirms the gain in efficiency obtained with the decoupled system. In comparison with a simple wire-wire corona configuration, the wire-cylinder-plate configuration increases the ionic wind velocity by up to a factor of 3, and the thrust by an order of magnitude.
TL;DR: In this paper, the expansion of a vapor plume ablated from an aluminum target into an argon gas at atmospheric pressure is experimentally investigated using time and space-resolved emission spectroscopy.
TL;DR: A qualitative analysis of the results is discussed in terms of the ion-dipole, ion-pair interactions, and hydrogen bonding between ILs and DMF molecules and their structural factors.
Abstract: To understand the molecular interactions between N,N-dimethylformamide (DMF) with two families of ionic liquids (ILs), we have measured thermophysical properties such as densities (ρ) and ultrasonic sound velocities (u) over the whole composition range at 25 °C under atmospheric pressure. The excess molar volume (VE) and the deviation in isentropic compressibilities (ΔKs) were predicted using these properties as a function of the concentration of IL. These results are fitted to the Redlich−Kister polynomials. The materials investigated in the present study included two families of ILs such as ammonium salts and imidazolium salts. Diethylammonium acetate ([Et2NH][CH3COO], DEAA), triethylammonium actetate ([Et3NH][CH3COO], TEAA), triethylammonium dihydogen phosphate ([Et3NH][H2PO4], TEAP), and triethylammonium sulfate ([Et3NH][HSO4], TEAS) are ammonium salts and 1-benzyl-3-methylimidazolium chloride ([Bmim][Cl]) belongs to the imidazolium family. The intermolecular interactions and structural effects were a...
TL;DR: In this paper, RF excited atmospheric pressure glow discharges are investigated in He-water mixtures in a parallel metal plate reactor by mass spectrometry and positive and negative ion fluxes to the electrode are investigated as a function of varying water concentration and discharge power.
Abstract: In this contribution RF excited atmospheric pressure glow discharges are investigated in He-water mixtures in a parallel metal plate reactor by mass spectrometry. Positive and negative ion fluxes to the electrode are investigated as a function of varying water concentration and discharge power. The dominant positive ions are H3O+ (and its clusters), OH+, O+, O-2(+), He-2(+), HeH+, O-2(+) and H-3(+). Negative ions are detectable from a concentration of 900 ppm water in He onwards. Coinciding with the emergence of the negative ions, there is a drop in positive ion flux to the mass spectrometer and a significant increase in applied voltage indicating increasing electron loss by attachment and ion loss by mutual (three and two body) positive - negative ion recombination. The dominant negative ions are OH- and its clusters. The negative ion flux increases with increasing water concentration. Positive and negative ion cluster formation increases with decreasing discharge power and increasing concentration of water vapour at constant power. It is shown that the size of the sampling orifice of the inlet of the mass spectrometer is important for sampling atmospheric pressure active plasmas due to the presence of the narrow sheath.
TL;DR: In this article, the ignition and reaction of Al/AgIO3 thermites for potential use in biocidal applications were investigated, and it was found that the AgIO3 was found to significantly outperform CuO and Fe2O3 oxidizers in pressurization tests, and this was attributed to the enhanced gas release as the AgI thermally decomposes to release iodine in addition to oxygen.
Abstract: The authors investigated the ignition and reaction of Al/AgIO3 thermites for potential use in biocidal applications. Rapid-heating wire experiments were performed to measure the ignition temperature and investigate the thermal decomposition of the oxidizer using a T-Jump/TOF Mass Spectrometer and an optical emission setup. Combustion experiments inside a constant-volume pressure cell were also carried out, and the relative performance was compared with other thermite systems. The ignition temperature in air at atmospheric pressure was found to be 1215 ± 40 K. The AgIO3 was found to significantly outperform CuO and Fe2O3 oxidizers in pressurization tests, and this is attributed to the enhanced gas release as the AgIO3 thermally decomposes to release iodine in addition to oxygen. The reacted product was collected to investigate the final state of the products. Transmission electron microscopy and X-ray diffraction were performed to show that the major Ag product species was AgI, and not elemental Ag and I2....
TL;DR: The linear dynamic ranges of benzene, toluene, and ethylbenzene are limited to approximately two orders of magnitude by saturation of the detection electronics, well below the compounds’ permissible exposure levels.
TL;DR: In this paper, an experimental study is presented to characterize a commercially available atmospheric pressure plasma jet (INPen), which can be used for local surface modification, e.g. changing the wettability as well as for thin film deposition with silicon-organic and metal-organic precursors to enhance scratch resistance or to lower the gas permeability.
Abstract: In this paper, an experimental study is presented to characterize a commercially available atmospheric pressure plasma jet (APPJ) kINPen which can be used for local surface modification, e.g. changing the wettability as well as for thin film deposition with silicon-organic and metal-organic precursors to enhance scratch resistance or to lower the gas permeability. Characterization of the jet discharge has been carried out by three methods: (i) measurement of the energy influx from the jet plasma to a substrate by a calorimetric probe, (ii) spatial resolved investigation of the plasma beam by optical emission spectroscopy (OES) and (iii) observation of the plasma jet by video imaging. The deposited SiO
x
and AlO
x
films were analyzed by XPS measurements.
TL;DR: In this article, the authors made observations of the local atmospheric pressure field and the long-period seismic noise fields both on the surface of the Earth and in a mine at a depth of 183 metres.
Abstract: Summary Observations have been made of the local atmospheric pressure field and the long-period seismic noise fields both on the surface of the Earth and in a mine at a depth of 183 metres. The observations show that during windy intervals and in the period range 20–100 s there is a strong correlation between local atmospheric pressure changes and the noise recorded by a vertical seismograph located on the surface. In contrast, over the same range of periods there is no correlation between the seismic noise recorded in the mine and local atmospheric pressure changes except during the passage of acoustic waves. It is shown that the noise in this pass band is not due to the buoyant response of the seismograph, but is caused by the motion of the Earth responding to atmospheric pressure changes.
TL;DR: In this paper, a thin proton conductive electrolyte membrane of BaCe0.85Y0.15O3-α (BCY15) was deposited on porous green NiO-BCY 15 substrate by the modified spin-coating method.