Recovery integral absorbance method in the full concentration range to eliminate the interference of background gas

2021 ◽  
pp. 120553
Author(s):  
Jiachen Sun ◽  
Jun Chang ◽  
Qinduan Zhang ◽  
Fupeng Wang ◽  
Zhifeng Zhang ◽  
...  
Keyword(s):  
Background Gas

Generation and origin of natural gas in Lower Palaeozoic shales from southern Sweden

1969 ◽  
pp. 37-40
Author(s):  
Niels Hemmingsen Schovsbo ◽  
Arne Thorshøj Nielsen
Keyword(s):  
Source Rocks ◽  
Southern Sweden ◽  
Hydrocarbon Gases ◽  
Biogenic Gas ◽  
South Central ◽  
Alum Shale ◽  
Marine Source ◽  
Lower Palaeozoic ◽  
Background Gas ◽  
Origin Of Natural Gas

The Lower Palaeozoic succession in Scandinavia includes several excellent marine source rocks notably the Alum Shale, the Dicellograptus shale and the Rastrites Shale that have been targets for shale gas exploration since 2008. We here report on samples of these source rocks from cored shallow scientific wells in southern Sweden. The samples contain both free and sorbed hydrocarbon gases with concentrations significantly above the background gas level. The gases consist of a mixture of thermogenic and bacterially derived gas. The latter likely derives from both carbonate reduction and methyl fermentation processes. The presence of both thermogenic and biogenic gas in the Lower Palaeozoic shales is in agreement with results from past and present exploration activities; thermogenic gas is a target in deeply buried, gas-mature shales in southernmost Sweden, Denmark and northern Poland, whereas biogenic gas is a target in shallow, immature-marginally mature shales in south central Sweden. We here document that biogenic gas signatures are present also in gas-mature shallow buried shales in Skåne in southernmost Sweden.

scholarly journals Growth and structure of multiphase gas in the cloud-crushing problem with cooling

2020 ◽  
Vol 501 (1) ◽  
pp. 1143-1159
Author(s):  
Vijit Kanjilal ◽  
Alankar Dutta ◽  
Prateek Sharma
Keyword(s):  
Mixing Layer ◽  
Cooling Time ◽  
Radiative Cooling ◽  
Late Time ◽  
Dense Gas ◽  
Mixed Gas ◽  
Continuous Growth ◽  
Dense Cloud ◽  
Set Up ◽  
Background Gas

ABSTRACT We revisit the problem of the growth of dense/cold gas in the cloud-crushing set-up with radiative cooling. The relative motion between the dense cloud and the diffuse medium produces a turbulent boundary layer of mixed gas with a short cooling time. This mixed gas may explain the ubiquity of the range of absorption/emission lines observed in various sources such as the circumgalactic medium and galactic/stellar/active galactic nucleus outflows. Recently, Gronke & Oh showed that the efficient radiative cooling of the mixed gas can lead to continuous growth of the dense cloud. They presented a threshold cloud size for the growth of dense gas that was contradicted by the more recent works of Li et al. & Sparre et al. These thresholds are qualitatively different as the former is based on the cooling time of the mixed gas whereas the latter is based on the cooling time of the hot gas. Our simulations agree with the threshold based on the cooling time of the mixed gas. We argue that the radiative cloud-crushing simulations should be run long enough to allow for the late-time growth of the dense gas due to cooling of the mixed gas but not so long that the background gas cools catastrophically. Moreover, the simulation domain should be large enough that the mixed gas is not lost through the boundaries. While the mixing layer is roughly isobaric, the emissivity of the gas at different temperatures is fundamentally different from an isobaric single-phase steady cooling flow.

A low background gas scintillation proportional counter

1988 ◽  
Vol 264 (2-3) ◽  
pp. 528-530 ◽  
Author(s):  
Sigenori Miyamoto ◽  
Makoto Saito ◽  
Kazuhiro Kimura ◽  
Hiroshi Tsunemi ◽  
Shunjii Kitamoto
Keyword(s):  
Proportional Counter ◽  
Low Background ◽  
Background Gas

Effect of Non-equilibrium Pulsed Ejection of Si Species into Background Gas on the Formation of Si Nanocrystallite and Nanocrystal-film

2011 ◽  
Vol 1305 ◽  
Author(s):  
Ikurou Umezu ◽  
Shunto Okubo ◽  
Akira Sugimura
Keyword(s):  
Laser Ablation ◽  
Film Growth ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
Hydrogen Gas ◽  
Gas Pressure ◽  
Spatial Confinement ◽  
The Individual ◽  
Background Gas ◽  
Non Equilibrium

ABSTRACTThe Si nanocrystal-films are prepared by pulsed laser ablation of Si target in a mixture of helium and hydrogen gas. The total gas pressure and hydrogen partial gas pressure were varied to control structure of nanocrystal-film. The surface of Si nanocrystallite was hydrogenated and degree of hydrogenation increased with increasing hydrogen partial gas pressure. The aggregate structure of nanocrystal-film depended on both the total gas pressure and the hydrogen partial gas pressure. The former and the latter alter spatial confinement of Si species during deposition and the surface hydrogenation of individual nanocrystal, respectively. Spatial confinement increases probability of collision between nanocrystals in the plume. While, surface hydrogenation prevents coalescence of nanocrystals. The individual or aggregated nanocrystals formed in the plume reach the substrate and the nanocrystal-film is deposited on the substrate. The non-equilibrium growth processes during pulsed laser ablation are essential for the formation of the surface structure and the subsequent nanocrystal-film growth. Our results indicate that the structure of nanocrystal-film depends on the probabilities of collision and coalescence between nanocrystals in the plume. These probabilities can be varied by controlling the total gas pressure and the hydrogen partial gas pressure.

Evaluation of Gross Alpha and Beta Activity Concentrations and Annual Effective Dose in Drinking Waters of Misan Province-Iraq Using Low Background Gas Flow Proportional Counter (LB- 4110)

2021 ◽  
Vol 19 (11) ◽  
pp. 22-31
Author(s):  
Sawsan Sh. Fleifil ◽  
Zahraa A. Ismail AL-Sudani
Keyword(s):  
Drinking Water ◽  
Effective Dose ◽  
Water Samples ◽  
Proportional Counter ◽  
Gas Flow ◽  
Annual Effective Dose ◽  
Tap Water ◽  
Beta Activity ◽  
Low Background ◽  
Background Gas

In this study, assessment of levels natural radioactivity in drinking water samples of Misan Province of Iraq was carried out. A total of 33 (Tigris river, station and Tap) water samples collected from eleven places in Misan Province of Iraq. The beta and alpha gross radioactivity of the samples water was measured and an average annual effective dose derived of drinking-water ingestion was estimation utilizing new model a LB-4110 low background gas flow proportional counter. The data indicated that the Beta and Alpha gross activities and annual effective dose in samples did not exceed WHO recommended levels (0.5 Bq/L of Alpha gross, 1.0 Bq/L of Beta gross and 0.1 mSv/y for annual effective dose).

scholarly journals Hydrodynamic Hamilton theory for discussing the space charge (Langmuir–Child Law) at high density particle currents between poles

1988 ◽  
Vol 6 (3) ◽  
pp. 579-586 ◽  
Author(s):  
Cord Passow
Keyword(s):  
Space Charge ◽  
Charge Carriers ◽  
The Self ◽  
Density Functions ◽  
Space Charge Limited Current ◽  
Stationary Plasma ◽  
Self Consistent ◽  
Solution Methods ◽  
Background Gas ◽  
Systematic Derivation

In order to calculate more generally the space-charge limited current between two points of different voltage, modern differential geometrical methods are applied. This problem was first treated by Child (1911) and later by Langmuir (1913). It is possible, for example, to account for effects due to more than one charge component as well as the influence of a neutral background gas (which causes ionization and scattering of charge carriers). A systematic derivation of the self-consistent representation based on a Hamilton theory for density functions is given, and solution methods are discussed. The concept is designed to investigate ion and electron diodes with very intense currents, but it may also be useful for treating space charge problems in a stationary plasma.

Diffusion cloud chamber operation and the background gas effect

1998 ◽  
Vol 46 (3-4) ◽  
pp. 195-209 ◽  
Author(s):  
Anne Bertelsmann ◽  
Richard H. Heist
Keyword(s):  
Cloud Chamber ◽  
Background Gas ◽  
Gas Effect

scholarly journals О газоструйном методе осаждения наноструктурных пленок серебра

2019 ◽  
Vol 89 (6) ◽  
pp. 830
Author(s):  
Н.Ю. Быков ◽  
А.И. Сафонов ◽  
Д.В. Лещев ◽  
С.В. Старинский ◽  
А.В. Булгаков
Keyword(s):  
Substrate Surface ◽  
Supersonic Jet ◽  
Direct Simulation Monte Carlo ◽  
Gas Jet ◽  
Silver Clusters ◽  
Silicon Substrates ◽  
Silver Nanostructures ◽  
Carrier Gas ◽  
Silver Vapor ◽  
Background Gas

AbstractThe synthesis of thin silver films by the gas-jet deposition method is experimentally and theoretically studied. When the metal is deposited onto silicon substrates from a supersonic jet of silver vapor with a helium carrier gas, nanostructured films with a 3−30 nm size of nanostructures are obtained for a 1230−1380 K range of jet source temperatures. The data on Ag–He gas-jet dynamics when it is expanded into vacuum (velocity, temperature, concentration, flux of particles onto a substrate) depending on parameters at the source (vapor temperature, flow rate of a carrier gas) are obtained by the method of direct simulation Monte Carlo. The range of optimal helium flow rates, when the efficiency of a gas-jet source is maximal, is determined. It is established that the presence of a background gas in a deposition chamber at pressure higher than 1 Pa decreases the flow of particles onto a substrate, and a simple way of its evaluation is proposed. Conditions for formation of silver clusters in the jet are determined by using the simulation. It is shown that for experimental deposition regimes there are no clusters in the jet, and the observed silver nanostructures are formed on the substrate surface.

scholarly journals Validation of spectroscopic gas analyzer accuracy using gravimetric standard gas mixtures: Impact of background gas composition on CO<sub>2</sub> quantitation by cavity ring-down spectroscopy

2017 ◽  
Author(s):  
Jeong Sik Lim ◽  
Miyeon Park ◽  
Jinbok Lee ◽  
Jeongsoon Lee
Keyword(s):  
Ambient Air ◽  
Gas Mixtures ◽  
Gas Composition ◽  
Optical Intensity ◽  
Negative Deviation ◽  
Gas Analyzer ◽  
Pressure Broadening ◽  
Background Gas ◽  
Standard Gas Mixtures ◽  
Cavity Ring Down

Abstract. Effect of background gas composition on the measurement of CO2 levels was investigated by wavelength-scanned cavity ring-down spectrometry (WS-CRDS) employing a spectral line centered at the R(1) of the (3 0° 1)III ← (0 0 0) band. For this purpose, eight cylinders with various gas compositions were gravimetrically and manometrically prepared within 2σ = 0.1 %, and these gas mixtures were introduced into the WS-CRDS analyzer calibrated against standards of ambient air composition. Depending on the gas composition, deviations between CRDS-determined and gravimetrically (or manometrically) assigned CO2 concentrations ranged from −9.77 to 5.36 μmol/mol, e.g., excess N2 exhibited a negative deviation, whereas excess Ar showed a positive one. The total pressure broadening coefficients (TBPCs) obtained from the composition of N2, O2 and Ar thoroughly corrected the deviations up to −0.5–0.6 μmol/mol, while these values were −0.43–1.43 μmol/mol considering PBCs induced by only N2. The use of TBPCs enhanced deviations to be corrected to ~ 0.15 %. Furthermore, the above correction linearly shifted CRDS responses for a wide extent of TPBCs ranging from 0.065 to 0.081 cm−1 atm−1. Thus, accurate measurements using optical intensity-based techniques such as WS-CRDS require TBPC-based instrument calibration.

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